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linux/net/rxrpc/input.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 06:55:01 +00:00
// SPDX-License-Identifier: GPL-2.0-or-later
rxrpc: Split the receive code Split the code that handles packet reception in softirq mode as a prelude to moving all the packet processing beyond routing to the appropriate call and setting up of a new call out into process context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:01:33 +00:00
/* Processing of received RxRPC packets
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*
rxrpc: Split the receive code Split the code that handles packet reception in softirq mode as a prelude to moving all the packet processing beyond routing to the appropriate call and setting up of a new call out into process context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:01:33 +00:00
* Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
* Written by David Howells (dhowells@redhat.com)
*/
rxrpc: Use pr_<level> and pr_fmt, reduce object size a few KB Use the more common kernel logging style and reduce object size. The logging message prefix changes from a mixture of "RxRPC:" and "RXRPC:" to "af_rxrpc: ". $ size net/rxrpc/built-in.o* text data bss dec hex filename 64172 1972 8304 74448 122d0 net/rxrpc/built-in.o.new 67512 1972 8304 77788 12fdc net/rxrpc/built-in.o.old Miscellanea: o Consolidate the ASSERT macros to use a single pr_err call with decimal and hexadecimal output and a stringified #OP argument Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-02 19:08:52 +00:00
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
#include "ar-internal.h"
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq,
enum rxrpc_abort_reason why)
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
{
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
/*
* Do TCP-style congestion management [RFC 5681].
*/
static void rxrpc_congestion_management(struct rxrpc_call *call,
struct sk_buff *skb,
rxrpc: Note serial number being ACK'd in the congestion management trace Note the serial number of the packet being ACK'd in the congestion management trace rather than the serial number of the ACK packet. Whilst the serial number of the ACK packet is useful for matching ACK packet in the output of wireshark, the serial number that the ACK is in response to is of more use in working out how different trace lines relate. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 21:37:16 +00:00
struct rxrpc_ack_summary *summary,
rxrpc_serial_t acked_serial)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
{
enum rxrpc_congest_change change = rxrpc_cong_no_change;
unsigned int cumulative_acks = call->cong_cumul_acks;
unsigned int cwnd = call->cong_cwnd;
bool resend = false;
summary->flight_size =
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
(call->tx_top - call->acks_hard_ack) - summary->nr_acks;
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
summary->retrans_timeo = true;
call->cong_ssthresh = max_t(unsigned int,
summary->flight_size / 2, 2);
cwnd = 1;
rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying on cwnd getting incremented beyond ssthresh and the window size, the mode being shifted and then cwnd being corrected. We need to make sure we switch into CA mode so that we stop marking every packet for ACK. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 08:26:12 +00:00
if (cwnd >= call->cong_ssthresh &&
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
call->cong_mode == RXRPC_CALL_SLOW_START) {
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
call->cong_tstamp = skb->tstamp;
cumulative_acks = 0;
}
}
cumulative_acks += summary->nr_new_acks;
if (cumulative_acks > 255)
cumulative_acks = 255;
summary->cwnd = call->cong_cwnd;
summary->ssthresh = call->cong_ssthresh;
summary->cumulative_acks = cumulative_acks;
summary->dup_acks = call->cong_dup_acks;
switch (call->cong_mode) {
case RXRPC_CALL_SLOW_START:
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (summary->saw_nacks)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto packet_loss_detected;
if (summary->cumulative_acks > 0)
cwnd += 1;
rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying on cwnd getting incremented beyond ssthresh and the window size, the mode being shifted and then cwnd being corrected. We need to make sure we switch into CA mode so that we stop marking every packet for ACK. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 08:26:12 +00:00
if (cwnd >= call->cong_ssthresh) {
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
call->cong_tstamp = skb->tstamp;
}
goto out;
case RXRPC_CALL_CONGEST_AVOIDANCE:
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (summary->saw_nacks)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto packet_loss_detected;
/* We analyse the number of packets that get ACK'd per RTT
* period and increase the window if we managed to fill it.
*/
rxrpc: Fix the excessive initial retransmission timeout rxrpc currently uses a fixed 4s retransmission timeout until the RTT is sufficiently sampled. This can cause problems with some fileservers with calls to the cache manager in the afs filesystem being dropped from the fileserver because a packet goes missing and the retransmission timeout is greater than the call expiry timeout. Fix this by: (1) Copying the RTT/RTO calculation code from Linux's TCP implementation and altering it to fit rxrpc. (2) Altering the various users of the RTT to make use of the new SRTT value. (3) Replacing the use of rxrpc_resend_timeout to use the calculated RTO value instead (which is needed in jiffies), along with a backoff. Notes: (1) rxrpc provides RTT samples by matching the serial numbers on outgoing DATA packets that have the RXRPC_REQUEST_ACK set and PING ACK packets against the reference serial number in incoming REQUESTED ACK and PING-RESPONSE ACK packets. (2) Each packet that is transmitted on an rxrpc connection gets a new per-connection serial number, even for retransmissions, so an ACK can be cross-referenced to a specific trigger packet. This allows RTT information to be drawn from retransmitted DATA packets also. (3) rxrpc maintains the RTT/RTO state on the rxrpc_peer record rather than on an rxrpc_call because many RPC calls won't live long enough to generate more than one sample. (4) The calculated SRTT value is in units of 8ths of a microsecond rather than nanoseconds. The (S)RTT and RTO values are displayed in /proc/net/rxrpc/peers. Fixes: 17926a79320a ([AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both"") Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-11 13:54:34 +00:00
if (call->peer->rtt_count == 0)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto out;
if (ktime_before(skb->tstamp,
rxrpc: Fix the excessive initial retransmission timeout rxrpc currently uses a fixed 4s retransmission timeout until the RTT is sufficiently sampled. This can cause problems with some fileservers with calls to the cache manager in the afs filesystem being dropped from the fileserver because a packet goes missing and the retransmission timeout is greater than the call expiry timeout. Fix this by: (1) Copying the RTT/RTO calculation code from Linux's TCP implementation and altering it to fit rxrpc. (2) Altering the various users of the RTT to make use of the new SRTT value. (3) Replacing the use of rxrpc_resend_timeout to use the calculated RTO value instead (which is needed in jiffies), along with a backoff. Notes: (1) rxrpc provides RTT samples by matching the serial numbers on outgoing DATA packets that have the RXRPC_REQUEST_ACK set and PING ACK packets against the reference serial number in incoming REQUESTED ACK and PING-RESPONSE ACK packets. (2) Each packet that is transmitted on an rxrpc connection gets a new per-connection serial number, even for retransmissions, so an ACK can be cross-referenced to a specific trigger packet. This allows RTT information to be drawn from retransmitted DATA packets also. (3) rxrpc maintains the RTT/RTO state on the rxrpc_peer record rather than on an rxrpc_call because many RPC calls won't live long enough to generate more than one sample. (4) The calculated SRTT value is in units of 8ths of a microsecond rather than nanoseconds. The (S)RTT and RTO values are displayed in /proc/net/rxrpc/peers. Fixes: 17926a79320a ([AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both"") Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-11 13:54:34 +00:00
ktime_add_us(call->cong_tstamp,
call->peer->srtt_us >> 3)))
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto out_no_clear_ca;
change = rxrpc_cong_rtt_window_end;
call->cong_tstamp = skb->tstamp;
if (cumulative_acks >= cwnd)
cwnd++;
goto out;
case RXRPC_CALL_PACKET_LOSS:
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (!summary->saw_nacks)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto resume_normality;
if (summary->new_low_nack) {
change = rxrpc_cong_new_low_nack;
call->cong_dup_acks = 1;
if (call->cong_extra > 1)
call->cong_extra = 1;
goto send_extra_data;
}
call->cong_dup_acks++;
if (call->cong_dup_acks < 3)
goto send_extra_data;
change = rxrpc_cong_begin_retransmission;
call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
call->cong_ssthresh = max_t(unsigned int,
summary->flight_size / 2, 2);
cwnd = call->cong_ssthresh + 3;
call->cong_extra = 0;
call->cong_dup_acks = 0;
resend = true;
goto out;
case RXRPC_CALL_FAST_RETRANSMIT:
if (!summary->new_low_nack) {
if (summary->nr_new_acks == 0)
cwnd += 1;
call->cong_dup_acks++;
if (call->cong_dup_acks == 2) {
change = rxrpc_cong_retransmit_again;
call->cong_dup_acks = 0;
resend = true;
}
} else {
change = rxrpc_cong_progress;
cwnd = call->cong_ssthresh;
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (!summary->saw_nacks)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
goto resume_normality;
}
goto out;
default:
BUG();
goto out;
}
resume_normality:
change = rxrpc_cong_cleared_nacks;
call->cong_dup_acks = 0;
call->cong_extra = 0;
call->cong_tstamp = skb->tstamp;
rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying on cwnd getting incremented beyond ssthresh and the window size, the mode being shifted and then cwnd being corrected. We need to make sure we switch into CA mode so that we stop marking every packet for ACK. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 08:26:12 +00:00
if (cwnd < call->cong_ssthresh)
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
call->cong_mode = RXRPC_CALL_SLOW_START;
else
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
out:
cumulative_acks = 0;
out_no_clear_ca:
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (cwnd >= RXRPC_TX_MAX_WINDOW)
cwnd = RXRPC_TX_MAX_WINDOW;
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
call->cong_cwnd = cwnd;
call->cong_cumul_acks = cumulative_acks;
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
summary->mode = call->cong_mode;
rxrpc: Note serial number being ACK'd in the congestion management trace Note the serial number of the packet being ACK'd in the congestion management trace rather than the serial number of the ACK packet. Whilst the serial number of the ACK packet is useful for matching ACK packet in the output of wireshark, the serial number that the ACK is in response to is of more use in working out how different trace lines relate. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 21:37:16 +00:00
trace_rxrpc_congest(call, summary, acked_serial, change);
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (resend)
rxrpc_resend(call, skb);
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
return;
packet_loss_detected:
change = rxrpc_cong_saw_nack;
call->cong_mode = RXRPC_CALL_PACKET_LOSS;
call->cong_dup_acks = 0;
goto send_extra_data;
send_extra_data:
/* Send some previously unsent DATA if we have some to advance the ACK
* state.
*/
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ||
summary->nr_acks != call->tx_top - call->acks_hard_ack) {
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
call->cong_extra++;
wake_up(&call->waitq);
}
goto out_no_clear_ca;
}
rxrpc: Move the cwnd degradation after transmitting packets When we've gone for >1RTT without transmitting a packet, we should reduce the ssthresh and cut the cwnd by half (as suggested in RFC2861 sec 3.1). However, we may receive ACK packets in a batch and the first of these may cut the cwnd, preventing further transmission, and each subsequent one cuts the cwnd yet further, reducing it to the floor and killing performance. Fix this by moving the cwnd reset to after doing the transmission and resetting the base time such that we don't cut the cwnd by half again for at least another RTT. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-11 13:47:35 +00:00
/*
* Degrade the congestion window if we haven't transmitted a packet for >1RTT.
*/
void rxrpc_congestion_degrade(struct rxrpc_call *call)
{
ktime_t rtt, now;
if (call->cong_mode != RXRPC_CALL_SLOW_START &&
call->cong_mode != RXRPC_CALL_CONGEST_AVOIDANCE)
return;
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_REPLY)
rxrpc: Move the cwnd degradation after transmitting packets When we've gone for >1RTT without transmitting a packet, we should reduce the ssthresh and cut the cwnd by half (as suggested in RFC2861 sec 3.1). However, we may receive ACK packets in a batch and the first of these may cut the cwnd, preventing further transmission, and each subsequent one cuts the cwnd yet further, reducing it to the floor and killing performance. Fix this by moving the cwnd reset to after doing the transmission and resetting the base time such that we don't cut the cwnd by half again for at least another RTT. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-11 13:47:35 +00:00
return;
rtt = ns_to_ktime(call->peer->srtt_us * (1000 / 8));
now = ktime_get_real();
if (!ktime_before(ktime_add(call->tx_last_sent, rtt), now))
return;
trace_rxrpc_reset_cwnd(call, now);
rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset);
call->tx_last_sent = now;
call->cong_mode = RXRPC_CALL_SLOW_START;
call->cong_ssthresh = max_t(unsigned int, call->cong_ssthresh,
call->cong_cwnd * 3 / 4);
call->cong_cwnd = max_t(unsigned int, call->cong_cwnd / 2, RXRPC_MIN_CWND);
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
/*
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
* Apply a hard ACK by advancing the Tx window.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
rxrpc: Generate a summary of the ACK state for later use Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:26 +00:00
struct rxrpc_ack_summary *summary)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
struct rxrpc_txbuf *txb;
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
bool rot_last = false;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
list_for_each_entry_rcu(txb, &call->tx_buffer, call_link, false) {
if (before_eq(txb->seq, call->acks_hard_ack))
continue;
rxrpc: Convert rxrpc_txbuf::flags into a mask and don't use atomics Convert the transmission buffer flags into a mask and use | and & rather than bitops functions (atomic ops are not required as only the I/O thread can manipulate them once submitted for transmission). The bottom byte can then correspond directly to the Rx protocol header flags. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-29 15:01:10 +00:00
if (txb->flags & RXRPC_LAST_PACKET) {
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
set_bit(RXRPC_CALL_TX_LAST, &call->flags);
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
rot_last = true;
}
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (txb->seq == to)
break;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (rot_last)
set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
_enter("%x,%x,%x,%d", to, call->acks_hard_ack, call->tx_top, rot_last);
rxrpc: Add missing wakeup on Tx window rotation We need to wake up the sender when Tx window rotation due to an incoming ACK makes space in the buffer otherwise the sender is liable to just hang endlessly. This problem isn't noticeable if the Tx phase transfers no more than will fit in a single window or the Tx window rotates fast enough that it doesn't get full. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 21:36:21 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (call->acks_lowest_nak == call->acks_hard_ack) {
call->acks_lowest_nak = to;
rxrpc: Fix congestion management rxrpc has a problem in its congestion management in that it saves the congestion window size (cwnd) from one call to another, but if this is 0 at the time is saved, then the next call may not actually manage to ever transmit anything. To this end: (1) Don't save cwnd between calls, but rather reset back down to the initial cwnd and re-enter slow-start if data transmission is idle for more than an RTT. (2) Preserve ssthresh instead, as that is a handy estimate of pipe capacity. Knowing roughly when to stop slow start and enter congestion avoidance can reduce the tendency to overshoot and drop larger amounts of packets when probing. In future, cwind growth also needs to be constrained when the window isn't being filled due to being application limited. Reported-by: Simon Wilkinson <sxw@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-03 17:49:11 +00:00
} else if (after(to, call->acks_lowest_nak)) {
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
summary->new_low_nack = true;
call->acks_lowest_nak = to;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
smp_store_release(&call->acks_hard_ack, to);
trace_rxrpc_txqueue(call, (rot_last ?
rxrpc_txqueue_rotate_last :
rxrpc_txqueue_rotate));
wake_up(&call->waitq);
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
return rot_last;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/*
* End the transmission phase of a call.
*
* This occurs when we get an ACKALL packet, the first DATA packet of a reply,
* or a final ACK packet.
*/
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
enum rxrpc_abort_reason abort_why)
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
{
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
if (unlikely(call->cong_last_nack)) {
rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
call->cong_last_nack = NULL;
}
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
switch (__rxrpc_call_state(call)) {
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
case RXRPC_CALL_CLIENT_SEND_REQUEST:
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
if (reply_begun) {
rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_RECV_REPLY);
trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
break;
}
rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_REPLY);
trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
break;
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_CALL_SERVER_AWAIT_ACK:
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
rxrpc_call_completed(call);
trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
break;
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
default:
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
kdebug("end_tx %s", rxrpc_call_states[__rxrpc_call_state(call)]);
rxrpc_proto_abort(call, call->tx_top, abort_why);
break;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
}
/*
* Begin the reply reception phase of a call.
*/
static bool rxrpc_receiving_reply(struct rxrpc_call *call)
{
rxrpc: Generate a summary of the ACK state for later use Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:26 +00:00
struct rxrpc_ack_summary summary = { 0 };
rxrpc: Strip barriers and atomics off of timer tracking Strip the atomic ops and barriering off of the call timer tracking as this is handled solely within the I/O thread, except for expect_term_by which is set by sendmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-30 16:39:15 +00:00
unsigned long now;
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
rxrpc_seq_t top = READ_ONCE(call->tx_top);
rxrpc: Reinitialise the call ACK and timer state for client reply phase Clear the ACK reason, ACK timer and resend timer when entering the client reply phase when the first DATA packet is received. New ACKs will be proposed once the data is queued. The resend timer is no longer relevant and we need to cancel ACKs scheduled to probe for a lost reply. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
if (call->ackr_reason) {
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
now = jiffies;
rxrpc: Strip barriers and atomics off of timer tracking Strip the atomic ops and barriering off of the call timer tracking as this is handled solely within the I/O thread, except for expect_term_by which is set by sendmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-30 16:39:15 +00:00
call->delay_ack_at = now + MAX_JIFFY_OFFSET;
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
rxrpc: Reinitialise the call ACK and timer state for client reply phase Clear the ACK reason, ACK timer and resend timer when entering the client reply phase when the first DATA packet is received. New ACKs will be proposed once the data is queued. The resend timer is no longer relevant and we need to cancel ACKs scheduled to probe for a lost reply. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
}
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
if (!rxrpc_rotate_tx_window(call, top, &summary)) {
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
return false;
}
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
}
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply);
return true;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
/*
* End the packet reception phase.
*/
static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
{
rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq);
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
_enter("%d,%s", call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)]);
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
switch (__rxrpc_call_state(call)) {
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
case RXRPC_CALL_CLIENT_RECV_REPLY:
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);
rxrpc_call_completed(call);
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
break;
case RXRPC_CALL_SERVER_RECV_REQUEST:
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
rxrpc_set_call_state(call, RXRPC_CALL_SERVER_ACK_REQUEST);
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_processing_op);
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
break;
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
default:
break;
}
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
rxrpc_seq_t window, rxrpc_seq_t wtop)
{
rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-17 10:44:22 +00:00
call->ackr_window = window;
call->ackr_wtop = wtop;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
}
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/*
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
* Push a DATA packet onto the Rx queue.
*/
static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb,
rxrpc_seq_t window, rxrpc_seq_t wtop,
enum rxrpc_receive_trace why)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
__skb_queue_tail(&call->recvmsg_queue, skb);
rxrpc_input_update_ack_window(call, window, wtop);
trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq);
rxrpc: Move call state changes from recvmsg to I/O thread Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-26 22:43:00 +00:00
if (last)
rxrpc_end_rx_phase(call, sp->hdr.serial);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
}
/*
* Process a DATA packet.
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
*/
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb,
bool *_notify)
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
struct sk_buff *oos;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc_serial_t serial = sp->hdr.serial;
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
unsigned int sack = call->ackr_sack_base;
rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-17 10:44:22 +00:00
rxrpc_seq_t window = call->ackr_window;
rxrpc_seq_t wtop = call->ackr_wtop;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
rxrpc_seq_t wlimit = window + call->rx_winsize - 1;
rxrpc_seq_t seq = sp->hdr.seq;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
int ack_reason = -1;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc_inc_stat(call->rxnet, stat_rx_data);
if (sp->hdr.flags & RXRPC_REQUEST_ACK)
rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
rxrpc: Improve jumbo packet counting Improve the information stored about jumbo packets so that we don't need to reparse them so much later. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
2019-08-19 08:25:37 +00:00
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
if (last) {
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
seq + 1 != wtop)
return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
} else {
if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
after_eq(seq, wtop)) {
pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
call->debug_id, seq, window, wtop, wlimit);
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Improve jumbo packet counting Improve the information stored about jumbo packets so that we don't need to reparse them so much later. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
2019-08-19 08:25:37 +00:00
}
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
if (after(seq, call->rx_highest_seq))
call->rx_highest_seq = seq;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
if (before(seq, window)) {
ack_reason = RXRPC_ACK_DUPLICATE;
goto send_ack;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
if (after(seq, wlimit)) {
ack_reason = RXRPC_ACK_EXCEEDS_WINDOW;
goto send_ack;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
/* Queue the packet. */
if (seq == window) {
if (sp->hdr.flags & RXRPC_REQUEST_ACK)
ack_reason = RXRPC_ACK_REQUESTED;
/* Send an immediate ACK if we fill in a hole */
else if (!skb_queue_empty(&call->rx_oos_queue))
ack_reason = RXRPC_ACK_DELAY;
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
else
rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-17 10:44:22 +00:00
call->ackr_nr_unacked++;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
window++;
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
if (after(window, wtop)) {
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_none);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
wtop = window;
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
} else {
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_advance);
sack = (sack + 1) % RXRPC_SACK_SIZE;
}
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
spin_lock(&call->recvmsg_queue.lock);
rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue);
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
*_notify = true;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
while ((oos = skb_peek(&call->rx_oos_queue))) {
struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
if (after(osp->hdr.seq, window))
break;
__skb_unlink(oos, &call->rx_oos_queue);
last = osp->hdr.flags & RXRPC_LAST_PACKET;
seq = osp->hdr.seq;
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
call->ackr_sack_table[sack] = 0;
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_fill);
sack = (sack + 1) % RXRPC_SACK_SIZE;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
window++;
rxrpc_input_queue_data(call, oos, window, wtop,
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
rxrpc_receive_queue_oos);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
spin_unlock(&call->recvmsg_queue.lock);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
call->ackr_sack_base = sack;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
} else {
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
unsigned int slot;
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE;
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
slot = seq - window;
sack = (sack + slot) % RXRPC_SACK_SIZE;
if (call->ackr_sack_table[sack % RXRPC_SACK_SIZE]) {
ack_reason = RXRPC_ACK_DUPLICATE;
goto send_ack;
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
}
rxrpc: Simplify ACK handling Now that general ACK transmission is done from the same thread as incoming DATA packet wrangling, there's no possibility that the SACK table will be being updated by the latter whilst the former is trying to copy it to an ACK. This means that we can safely rotate the SACK table whilst updating it without having to take a lock, rather than keeping all the bits inside it in fixed place and copying and then rotating it in the transmitter. Therefore, simplify SACK handing by keeping track of starting point in the ring and rotate slots down as we consume them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-16 07:01:32 +00:00
call->ackr_sack_table[sack % RXRPC_SACK_SIZE] |= 1;
trace_rxrpc_sack(call, seq, sack, rxrpc_sack_oos);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
if (after(seq + 1, wtop)) {
wtop = seq + 1;
rxrpc_input_update_ack_window(call, window, wtop);
}
skb_queue_walk(&call->rx_oos_queue, oos) {
struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
if (after(osp->hdr.seq, seq)) {
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
__skb_queue_before(&call->rx_oos_queue, oos, skb);
goto oos_queued;
}
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
__skb_queue_tail(&call->rx_oos_queue, skb);
oos_queued:
trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos,
sp->hdr.serial, sp->hdr.seq);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
}
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
send_ack:
if (ack_reason >= 0)
rxrpc_send_ACK(call, ack_reason, serial,
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc_propose_ack_input_data);
else
rxrpc_propose_delay_ACK(call, serial,
rxrpc_propose_ack_input_data);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
/*
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
* Split a jumbo packet and file the bits separately.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
struct rxrpc_jumbo_header jhdr;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
struct sk_buff *jskb;
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int len = skb->len - offset;
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
bool notify = false;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
if (len < RXRPC_JUMBO_SUBPKTLEN)
goto protocol_error;
if (sp->hdr.flags & RXRPC_LAST_PACKET)
goto protocol_error;
if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
&jhdr, sizeof(jhdr)) < 0)
goto protocol_error;
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
jskb = skb_clone(skb, GFP_NOFS);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
if (!jskb) {
kdebug("couldn't clone");
return false;
}
rxrpc: trace: Don't use __builtin_return_address for sk_buff tracing In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the sk_buff tracepoint. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-21 14:31:21 +00:00
rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
jsp = rxrpc_skb(jskb);
jsp->offset = offset;
jsp->len = RXRPC_JUMBO_DATALEN;
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
rxrpc_input_data_one(call, jskb, &notify);
rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
sp->hdr.flags = jhdr.flags;
sp->hdr._rsvd = ntohs(jhdr._rsvd);
sp->hdr.seq++;
sp->hdr.serial++;
offset += RXRPC_JUMBO_SUBPKTLEN;
len -= RXRPC_JUMBO_SUBPKTLEN;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
sp->offset = offset;
sp->len = len;
rxrpc: Simplify skbuff accounting in receive path A received skbuff needs a ref when it gets put on a call data queue or conn packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops to avoid double-dropping the skbuff ref so that we can avoid getting a ref when we queue the packet. Change this so that the skbuff ref is unconditionally dropped by the caller of rxrpc_input_packet(). An additional ref is then taken on the packet if it is pushed onto a queue. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 14:43:51 +00:00
rxrpc_input_data_one(call, skb, &notify);
if (notify) {
trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial);
rxrpc_notify_socket(call);
}
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
return true;
protocol_error:
return false;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/*
rxrpc: Pass the input handler's data skb reference to the Rx ring Pass the reference held on a DATA skb in the rxrpc input handler into the Rx ring rather than getting an additional ref for this and then dropping the original ref at the end. Signed-off-by: David Howells <dhowells@redhat.com>
2019-08-19 08:25:36 +00:00
* Process a DATA packet, adding the packet to the Rx ring. The caller's
* packet ref must be passed on or discarded.
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
*/
rxrpc: Don't bother generating maxSkew in the ACK packet Don't bother generating maxSkew in the ACK packet as it has been obsolete since AFS 3.1. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
2019-08-09 14:20:41 +00:00
static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
rxrpc_serial_t serial = sp->hdr.serial;
rxrpc_seq_t seq0 = sp->hdr.seq;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: De-atomic call->ackr_window and call->ackr_nr_unacked call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-17 10:44:22 +00:00
_enter("{%x,%x,%x},{%u,%x}",
call->ackr_window, call->ackr_wtop, call->rx_highest_seq,
rxrpc: Get rid of the Rx ring Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-08-27 13:27:56 +00:00
skb->len, seq0);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
if (__rxrpc_call_is_complete(call))
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
return;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
switch (__rxrpc_call_state(call)) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
/* Received data implicitly ACKs all of the request
* packets we sent when we're acting as a client.
*/
if (!rxrpc_receiving_reply(call))
goto out_notify;
break;
case RXRPC_CALL_SERVER_RECV_REQUEST: {
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
unsigned long timo = READ_ONCE(call->next_req_timo);
unsigned long now, expect_req_by;
if (timo) {
now = jiffies;
expect_req_by = now + timo;
rxrpc: Strip barriers and atomics off of timer tracking Strip the atomic ops and barriering off of the call timer tracking as this is handled solely within the I/O thread, except for expect_term_by which is set by sendmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-30 16:39:15 +00:00
call->expect_req_by = now + timo;
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
rxrpc_reduce_call_timer(call, expect_req_by, now,
rxrpc_timer_set_for_idle);
}
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
break;
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
}
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
default:
break;
}
rxrpc: Allocate ACK records at proposal and queue for transmission Allocate rxrpc_txbuf records for ACKs and put onto a queue for the transmitter thread to dispatch. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-30 21:48:13 +00:00
rxrpc: Clone received jumbo subpackets and queue separately Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-07 16:44:39 +00:00
if (!rxrpc_input_split_jumbo(call, skb)) {
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo);
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
goto out_notify;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
rxrpc: Fix overproduction of wakeups to recvmsg() Fix three cases of overproduction of wakeups: (1) rxrpc_input_split_jumbo() conditionally notifies the app that there's data for recvmsg() to collect if it queues some data - and then its only caller, rxrpc_input_data(), goes and wakes up recvmsg() anyway. Fix the rxrpc_input_data() to only do the wakeup in failure cases. (2) If a DATA packet is received for a call by the I/O thread whilst recvmsg() is busy draining the call's rx queue in the app thread, the call will left on the recvmsg() queue for recvmsg() to pick up, even though there isn't any data on it. This can cause an unexpected recvmsg() with a 0 return and no MSG_EOR set after the reply has been posted to a service call. Fix this by discarding pending calls from the recvmsg() queue that don't need servicing yet. (3) Not-yet-completed calls get requeued after having data read from them, even if they have no data to read. Fix this by only requeuing them if they have data waiting on them; if they don't, the I/O thread will requeue them when data arrives or they fail. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/3386149.1676497685@warthog.procyon.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-15 21:48:05 +00:00
return;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
out_notify:
rxrpc: Fix insufficient receive notification generation In rxrpc_input_data(), rxrpc_notify_socket() is called if the base sequence number of the packet is immediately following the hard-ack point at the end of the function. However, this isn't sufficient, since the recvmsg side may have been advancing the window and then overrun the position in which we're adding - at which point rx_hard_ack >= seq0 and no notification is generated. Fix this by always generating a notification at the end of the input function. Without this, a long call may stall, possibly indefinitely. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>
2020-01-30 21:50:36 +00:00
trace_rxrpc_notify_socket(call->debug_id, serial);
rxrpc_notify_socket(call);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
_leave(" [queued]");
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
/*
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
* See if there's a cached RTT probe to complete.
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
*/
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
ktime_t resp_time,
rxrpc_serial_t acked_serial,
rxrpc_serial_t ack_serial,
enum rxrpc_rtt_rx_trace type)
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
{
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
rxrpc_serial_t orig_serial;
unsigned long avail;
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
ktime_t sent_at;
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
bool matched = false;
int i;
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
avail = READ_ONCE(call->rtt_avail);
smp_rmb(); /* Read avail bits before accessing data. */
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
continue;
rxrpc: Fix RTT gathering Fix RTT information gathering in AF_RXRPC by the following means: (1) Enable Rx timestamping on the transport socket with SO_TIMESTAMPNS. (2) If the sk_buff doesn't have a timestamp set when rxrpc_data_ready() collects it, set it at that point. (3) Allow ACKs to be requested on the last packet of a client call, but not a service call. We need to be careful lest we undo: bf7d620abf22c321208a4da4f435e7af52551a21 Author: David Howells <dhowells@redhat.com> Date: Thu Oct 6 08:11:51 2016 +0100 rxrpc: Don't request an ACK on the last DATA packet of a call's Tx phase but that only really applies to service calls that we're handling, since the client side gets to send the final ACK (or not). (4) When about to transmit an ACK or DATA packet, record the Tx timestamp before only; don't update the timestamp afterwards. (5) Switch the ordering between recording the serial and recording the timestamp to always set the serial number first. The serial number shouldn't be seen referenced by an ACK packet until we've transmitted the packet bearing it - so in the Rx path, we don't need the timestamp until we've checked the serial number. Fixes: cf1a6474f807 ("rxrpc: Add per-peer RTT tracker") Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-27 14:13:08 +00:00
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
sent_at = call->rtt_sent_at[i];
orig_serial = call->rtt_serial[i];
if (orig_serial == acked_serial) {
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
smp_mb(); /* Read data before setting avail bit */
set_bit(i, &call->rtt_avail);
rxrpc: Fix RTT determination to use any ACK as a source Fix RTT determination to be able to use any type of ACK as the response from which RTT can be calculated provided its ack.serial is non-zero and matches the serial number of an outgoing DATA or ACK packet. This shouldn't be limited to REQUESTED-type ACKs as these can have other types substituted for them for things like duplicate or out-of-order packets. Fixes: 4700c4d80b7b ("rxrpc: Fix loss of RTT samples due to interposed ACK") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:58 +00:00
rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
sent_at, resp_time);
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
matched = true;
}
/* If a later serial is being acked, then mark this slot as
* being available.
*/
if (after(acked_serial, orig_serial)) {
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
orig_serial, acked_serial, 0, 0);
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
smp_wmb();
set_bit(i, &call->rtt_avail);
}
}
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
if (!matched)
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
rxrpc: Obtain RTT data by requesting ACKs on DATA packets In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
/*
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
* Process the extra information that may be appended to an ACK packet
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb,
struct rxrpc_acktrailer *trailer)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_peer *peer;
unsigned int mtu;
rxrpc: Wake up the transmitter if Rx window size increases on the peer The RxRPC ACK packet may contain an extension that includes the peer's current Rx window size for this call. We adjust the local Tx window size to match. However, the transmitter can stall if the receive window is reduced to 0 by the peer and then reopened. This is because the normal way that the transmitter is re-energised is by dropping something out of our Tx queue and thus making space. When a single gap is made, the transmitter is woken up. However, because there's nothing in the Tx queue at this point, this doesn't happen. To fix this, perform a wake_up() any time we see the peer's Rx window size increasing. The observable symptom is that calls start failing on ETIMEDOUT and the following: kAFS: SERVER DEAD state=-62 appears in dmesg. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 07:48:49 +00:00
bool wake = false;
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
u32 rwind = ntohl(trailer->rwind);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (rwind > RXRPC_TX_MAX_WINDOW)
rwind = RXRPC_TX_MAX_WINDOW;
rxrpc: Wake up the transmitter if Rx window size increases on the peer The RxRPC ACK packet may contain an extension that includes the peer's current Rx window size for this call. We adjust the local Tx window size to match. However, the transmitter can stall if the receive window is reduced to 0 by the peer and then reopened. This is because the normal way that the transmitter is re-energised is by dropping something out of our Tx queue and thus making space. When a single gap is made, the transmitter is woken up. However, because there's nothing in the Tx queue at this point, this doesn't happen. To fix this, perform a wake_up() any time we see the peer's Rx window size increasing. The observable symptom is that calls start failing on ETIMEDOUT and the following: kAFS: SERVER DEAD state=-62 appears in dmesg. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 07:48:49 +00:00
if (call->tx_winsize != rwind) {
if (rwind > call->tx_winsize)
wake = true;
rxrpc: Fix handling of rwind from an ACK packet The handling of the receive window size (rwind) from a received ACK packet is not correct. The rxrpc_input_ackinfo() function currently checks the current Tx window size against the rwind from the ACK to see if it has changed, but then limits the rwind size before storing it in the tx_winsize member and, if it increased, wake up the transmitting process. This means that if rwind > RXRPC_RXTX_BUFF_SIZE - 1, this path will always be followed. Fix this by limiting rwind before we compare it to tx_winsize. The effect of this can be seen by enabling the rxrpc_rx_rwind_change tracepoint. Fixes: 702f2ac87a9a ("rxrpc: Wake up the transmitter if Rx window size increases on the peer") Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-17 22:01:23 +00:00
trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
rxrpc: Wake up the transmitter if Rx window size increases on the peer The RxRPC ACK packet may contain an extension that includes the peer's current Rx window size for this call. We adjust the local Tx window size to match. However, the transmitter can stall if the receive window is reduced to 0 by the peer and then reopened. This is because the normal way that the transmitter is re-energised is by dropping something out of our Tx queue and thus making space. When a single gap is made, the transmitter is woken up. However, because there's nothing in the Tx queue at this point, this doesn't happen. To fix this, perform a wake_up() any time we see the peer's Rx window size increasing. The observable symptom is that calls start failing on ETIMEDOUT and the following: kAFS: SERVER DEAD state=-62 appears in dmesg. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 07:48:49 +00:00
call->tx_winsize = rwind;
}
rxrpc: Reduce ssthresh to peer's receive window When we receive an ACK from the peer that tells us what the peer's receive window (rwind) is, we should reduce ssthresh to rwind if rwind is smaller than ssthresh. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 08:33:27 +00:00
if (call->cong_ssthresh > rwind)
call->cong_ssthresh = rwind;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
mtu = min(ntohl(trailer->maxMTU), ntohl(trailer->ifMTU));
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
peer = call->peer;
if (mtu < peer->maxdata) {
rxrpc: Remove the _bh annotation from all the spinlocks None of the spinlocks in rxrpc need a _bh annotation now as the RCU callback routines no longer take spinlocks and the bulk of the packet wrangling code is now run in the I/O thread, not softirq context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-24 10:21:15 +00:00
spin_lock(&peer->lock);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
peer->maxdata = mtu;
peer->mtu = mtu + peer->hdrsize;
rxrpc: Remove the _bh annotation from all the spinlocks None of the spinlocks in rxrpc need a _bh annotation now as the RCU callback routines no longer take spinlocks and the bulk of the packet wrangling code is now run in the I/O thread, not softirq context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-24 10:21:15 +00:00
spin_unlock(&peer->lock);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
rxrpc: Wake up the transmitter if Rx window size increases on the peer The RxRPC ACK packet may contain an extension that includes the peer's current Rx window size for this call. We adjust the local Tx window size to match. However, the transmitter can stall if the receive window is reduced to 0 by the peer and then reopened. This is because the normal way that the transmitter is re-energised is by dropping something out of our Tx queue and thus making space. When a single gap is made, the transmitter is woken up. However, because there's nothing in the Tx queue at this point, this doesn't happen. To fix this, perform a wake_up() any time we see the peer's Rx window size increasing. The observable symptom is that calls start failing on ETIMEDOUT and the following: kAFS: SERVER DEAD state=-62 appears in dmesg. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 07:48:49 +00:00
if (wake)
wake_up(&call->waitq);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
/*
* Determine how many nacks from the previous ACK have now been satisfied.
*/
static rxrpc_seq_t rxrpc_input_check_prev_ack(struct rxrpc_call *call,
struct rxrpc_ack_summary *summary,
rxrpc_seq_t seq)
{
struct sk_buff *skb = call->cong_last_nack;
struct rxrpc_ackpacket ack;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
unsigned int i, new_acks = 0, retained_nacks = 0;
rxrpc_seq_t old_seq = sp->first_ack;
u8 *acks = skb->data + sizeof(struct rxrpc_wire_header) + sizeof(ack);
if (after_eq(seq, old_seq + sp->nr_acks)) {
summary->nr_new_acks += sp->nr_nacks;
summary->nr_new_acks += seq - (old_seq + sp->nr_acks);
summary->nr_retained_nacks = 0;
} else if (seq == old_seq) {
summary->nr_retained_nacks = sp->nr_nacks;
} else {
for (i = 0; i < sp->nr_acks; i++) {
if (acks[i] == RXRPC_ACK_TYPE_NACK) {
if (before(old_seq + i, seq))
new_acks++;
else
retained_nacks++;
}
}
summary->nr_new_acks += new_acks;
summary->nr_retained_nacks = retained_nacks;
}
return old_seq + sp->nr_acks;
}
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/*
* Process individual soft ACKs.
*
* Each ACK in the array corresponds to one packet and can be either an ACK or
* a NAK. If we get find an explicitly NAK'd packet we resend immediately;
* packets that lie beyond the end of the ACK list are scheduled for resend by
* the timer on the basis that the peer might just not have processed them at
* the time the ACK was sent.
*/
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
static void rxrpc_input_soft_acks(struct rxrpc_call *call,
struct rxrpc_ack_summary *summary,
struct sk_buff *skb,
rxrpc_seq_t seq,
rxrpc_seq_t since)
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
{
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
unsigned int i, old_nacks = 0;
rxrpc_seq_t lowest_nak = seq + sp->nr_acks;
u8 *acks = skb->data + sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket);
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
for (i = 0; i < sp->nr_acks; i++) {
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (acks[i] == RXRPC_ACK_TYPE_ACK) {
rxrpc: Generate a summary of the ACK state for later use Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:26 +00:00
summary->nr_acks++;
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
if (after_eq(seq, since))
summary->nr_new_acks++;
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
} else {
summary->saw_nacks = true;
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
if (before(seq, since)) {
/* Overlap with previous ACK */
old_nacks++;
} else {
summary->nr_new_nacks++;
sp->nr_nacks++;
}
if (before(seq, lowest_nak))
lowest_nak = seq;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
seq++;
}
if (lowest_nak != call->acks_lowest_nak) {
call->acks_lowest_nak = lowest_nak;
summary->new_low_nack = true;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
/* We *can* have more nacks than we did - the peer is permitted to drop
* packets it has soft-acked and re-request them. Further, it is
* possible for the nack distribution to change whilst the number of
* nacks stays the same or goes down.
*/
if (old_nacks < summary->nr_retained_nacks)
summary->nr_new_acks += summary->nr_retained_nacks - old_nacks;
summary->nr_retained_nacks = old_nacks;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
rxrpc: Fix ack discard The Rx protocol has a "previousPacket" field in it that is not handled in the same way by all protocol implementations. Sometimes it contains the serial number of the last DATA packet received, sometimes the sequence number of the last DATA packet received and sometimes the highest sequence number so far received. AF_RXRPC is using this to weed out ACKs that are out of date (it's possible for ACK packets to get reordered on the wire), but this does not work with OpenAFS which will just stick the sequence number of the last packet seen into previousPacket. The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are timing out when partly sent. A trace was captured, with an additional tracepoint to show ACKs being discarded in rxrpc_input_ack(). Here's an excerpt showing the problem. 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09 A DATA packet with sequence number 00024499 has been transmitted (the "q=" field). ... 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2 The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence number 00024499, but did see seq 0002449a (previousPacket, shown as "p=", skipped the number, but firstPacket, "f=", which shows the bottom of the window is set at that point). 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS* The packet has been retransmitted. Retransmission recurs until the peer says it got the packet. 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6 More OOS ACKs indicate that the other packets that are already in the transmission pipeline are being received. The specific-ACK list is up to 6 ACKs and NAKs. ... 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS* 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32 At this point, the server's receive window is full (n=32) with presumably 1 NAK'd packet and 31 ACK'd packets. We can't transmit any more packets. 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS* 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25 And now we've received an ACK indicating that a DATA retransmission was received. 7 packets have been processed (the occupied part of the window moved, as indicated by f= and n=). 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8 However, the DLY ACK gets discarded because its previousPacket has gone backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the ACK at 52873.293850). We then end up in a continuous cycle of retransmit/discard. kafs fails to update its window because it's discarding the ACKs and can't transmit an extra packet that would clear the issue because the window is full. OpenAFS doesn't change the previousPacket value in the ACKs because no new DATA packets are received with a different previousPacket number. Fix this by altering the discard check to only discard an ACK based on previousPacket if there was no advance in the firstPacket. This allows us to transmit a new packet which will cause previousPacket to advance in the next ACK. The check, however, needs to allow for the possibility that previousPacket may actually have had the serial number placed in it instead - in which case it will go outside the window and we should ignore it. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-29 22:48:43 +00:00
/*
* Return true if the ACK is valid - ie. it doesn't appear to have regressed
* with respect to the ack state conveyed by preceding ACKs.
*/
static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
{
rxrpc: Fix overlapping ACK accounting Fix accidental overlapping of Rx-phase ACK accounting with Tx-phase ACK accounting through variables shared between the two. call->acks_* members refer to ACKs received in the Tx phase and call->ackr_* members to ACKs sent/to be sent during the Rx phase. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 08:03:18 +00:00
rxrpc_seq_t base = READ_ONCE(call->acks_first_seq);
rxrpc: Fix ack discard The Rx protocol has a "previousPacket" field in it that is not handled in the same way by all protocol implementations. Sometimes it contains the serial number of the last DATA packet received, sometimes the sequence number of the last DATA packet received and sometimes the highest sequence number so far received. AF_RXRPC is using this to weed out ACKs that are out of date (it's possible for ACK packets to get reordered on the wire), but this does not work with OpenAFS which will just stick the sequence number of the last packet seen into previousPacket. The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are timing out when partly sent. A trace was captured, with an additional tracepoint to show ACKs being discarded in rxrpc_input_ack(). Here's an excerpt showing the problem. 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09 A DATA packet with sequence number 00024499 has been transmitted (the "q=" field). ... 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2 The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence number 00024499, but did see seq 0002449a (previousPacket, shown as "p=", skipped the number, but firstPacket, "f=", which shows the bottom of the window is set at that point). 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS* The packet has been retransmitted. Retransmission recurs until the peer says it got the packet. 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6 More OOS ACKs indicate that the other packets that are already in the transmission pipeline are being received. The specific-ACK list is up to 6 ACKs and NAKs. ... 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS* 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32 At this point, the server's receive window is full (n=32) with presumably 1 NAK'd packet and 31 ACK'd packets. We can't transmit any more packets. 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS* 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25 And now we've received an ACK indicating that a DATA retransmission was received. 7 packets have been processed (the occupied part of the window moved, as indicated by f= and n=). 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8 However, the DLY ACK gets discarded because its previousPacket has gone backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the ACK at 52873.293850). We then end up in a continuous cycle of retransmit/discard. kafs fails to update its window because it's discarding the ACKs and can't transmit an extra packet that would clear the issue because the window is full. OpenAFS doesn't change the previousPacket value in the ACKs because no new DATA packets are received with a different previousPacket number. Fix this by altering the discard check to only discard an ACK based on previousPacket if there was no advance in the firstPacket. This allows us to transmit a new packet which will cause previousPacket to advance in the next ACK. The check, however, needs to allow for the possibility that previousPacket may actually have had the serial number placed in it instead - in which case it will go outside the window and we should ignore it. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-29 22:48:43 +00:00
if (after(first_pkt, base))
return true; /* The window advanced */
if (before(first_pkt, base))
return false; /* firstPacket regressed */
rxrpc: Fix overlapping ACK accounting Fix accidental overlapping of Rx-phase ACK accounting with Tx-phase ACK accounting through variables shared between the two. call->acks_* members refer to ACKs received in the Tx phase and call->ackr_* members to ACKs sent/to be sent during the Rx phase. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 08:03:18 +00:00
if (after_eq(prev_pkt, call->acks_prev_seq))
rxrpc: Fix ack discard The Rx protocol has a "previousPacket" field in it that is not handled in the same way by all protocol implementations. Sometimes it contains the serial number of the last DATA packet received, sometimes the sequence number of the last DATA packet received and sometimes the highest sequence number so far received. AF_RXRPC is using this to weed out ACKs that are out of date (it's possible for ACK packets to get reordered on the wire), but this does not work with OpenAFS which will just stick the sequence number of the last packet seen into previousPacket. The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are timing out when partly sent. A trace was captured, with an additional tracepoint to show ACKs being discarded in rxrpc_input_ack(). Here's an excerpt showing the problem. 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09 A DATA packet with sequence number 00024499 has been transmitted (the "q=" field). ... 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2 The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence number 00024499, but did see seq 0002449a (previousPacket, shown as "p=", skipped the number, but firstPacket, "f=", which shows the bottom of the window is set at that point). 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS* The packet has been retransmitted. Retransmission recurs until the peer says it got the packet. 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6 More OOS ACKs indicate that the other packets that are already in the transmission pipeline are being received. The specific-ACK list is up to 6 ACKs and NAKs. ... 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS* 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32 At this point, the server's receive window is full (n=32) with presumably 1 NAK'd packet and 31 ACK'd packets. We can't transmit any more packets. 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS* 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25 And now we've received an ACK indicating that a DATA retransmission was received. 7 packets have been processed (the occupied part of the window moved, as indicated by f= and n=). 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8 However, the DLY ACK gets discarded because its previousPacket has gone backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the ACK at 52873.293850). We then end up in a continuous cycle of retransmit/discard. kafs fails to update its window because it's discarding the ACKs and can't transmit an extra packet that would clear the issue because the window is full. OpenAFS doesn't change the previousPacket value in the ACKs because no new DATA packets are received with a different previousPacket number. Fix this by altering the discard check to only discard an ACK based on previousPacket if there was no advance in the firstPacket. This allows us to transmit a new packet which will cause previousPacket to advance in the next ACK. The check, however, needs to allow for the possibility that previousPacket may actually have had the serial number placed in it instead - in which case it will go outside the window and we should ignore it. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-29 22:48:43 +00:00
return true; /* previousPacket hasn't regressed. */
/* Some rx implementations put a serial number in previousPacket. */
if (after_eq(prev_pkt, base + call->tx_winsize))
return false;
return true;
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
/*
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
* Process an ACK packet.
*
* ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
* in the ACK array. Anything before that is hard-ACK'd and may be discarded.
*
* A hard-ACK means that a packet has been processed and may be discarded; a
* soft-ACK means that the packet may be discarded and retransmission
* requested. A phase is complete when all packets are hard-ACK'd.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Don't bother generating maxSkew in the ACK packet Don't bother generating maxSkew in the ACK packet as it has been obsolete since AFS 3.1. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
2019-08-09 14:20:41 +00:00
static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Generate a summary of the ACK state for later use Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:26 +00:00
struct rxrpc_ack_summary summary = { 0 };
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
struct rxrpc_ackpacket ack;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
struct rxrpc_acktrailer trailer;
rxrpc: Keep the ACK serial in a var in rxrpc_input_ack() Keep the ACK serial number in a variable in rxrpc_input_ack() as it's used frequently. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20 13:12:33 +00:00
rxrpc_serial_t ack_serial, acked_serial;
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt, since;
rxrpc: The offset field in struct rxrpc_skb_priv is unnecessary The offset field in struct rxrpc_skb_priv is unnecessary as the value can always be calculated. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 12:26:03 +00:00
int nr_acks, offset, ioffset;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
_enter("");
rxrpc: The offset field in struct rxrpc_skb_priv is unnecessary The offset field in struct rxrpc_skb_priv is unnecessary as the value can always be calculated. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 12:26:03 +00:00
offset = sizeof(struct rxrpc_wire_header);
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (skb_copy_bits(skb, offset, &ack, sizeof(ack)) < 0)
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack);
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
offset += sizeof(ack);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Keep the ACK serial in a var in rxrpc_input_ack() Keep the ACK serial number in a variable in rxrpc_input_ack() as it's used frequently. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20 13:12:33 +00:00
ack_serial = sp->hdr.serial;
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
acked_serial = ntohl(ack.serial);
first_soft_ack = ntohl(ack.firstPacket);
prev_pkt = ntohl(ack.previousPacket);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
hard_ack = first_soft_ack - 1;
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
nr_acks = ack.nAcks;
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
sp->first_ack = first_soft_ack;
sp->nr_acks = nr_acks;
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
summary.ack_reason = (ack.reason < RXRPC_ACK__INVALID ?
ack.reason : RXRPC_ACK__INVALID);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
rxrpc: Keep the ACK serial in a var in rxrpc_input_ack() Keep the ACK serial number in a variable in rxrpc_input_ack() as it's used frequently. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20 13:12:33 +00:00
trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
rxrpc: Fix detection of out of order acks The rxrpc packet serial number cannot be safely used to compute out of order ack packets for several reasons: 1. The allocation of serial numbers cannot be assumed to imply the order by which acks are populated and transmitted. In some rxrpc implementations, delayed acks and ping acks are transmitted asynchronously to the receipt of data packets and so may be transmitted out of order. As a result, they can race with idle acks. 2. Serial numbers are allocated by the rxrpc connection and not the call and as such may wrap independently if multiple channels are in use. In any case, what matters is whether the ack packet provides new information relating to the bounds of the window (the firstPacket and previousPacket in the ACK data). Fix this by discarding packets that appear to wind back the window bounds rather than on serial number procession. Fixes: 298bc15b2079 ("rxrpc: Only take the rwind and mtu values from latest ACK") Signed-off-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 15:34:16 +00:00
first_soft_ack, prev_pkt,
rxrpc: Add some more tracing Add the following extra tracing information: (1) Modify the rxrpc_transmit tracepoint to record the Tx window size as this is varied by the slow-start algorithm. (2) Modify the rxrpc_rx_ack tracepoint to record more information from received ACK packets. (3) Add an rxrpc_rx_data tracepoint to record the information in DATA packets. (4) Add an rxrpc_disconnect_call tracepoint to record call disconnection, including the reason the call was disconnected. (5) Add an rxrpc_improper_term tracepoint to record implicit termination of a call by a client either by starting a new call on a particular connection channel without first transmitting the final ACK for the previous call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 10:38:34 +00:00
summary.ack_reason, nr_acks);
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
rxrpc_inc_stat(call->rxnet, stat_rx_acks[ack.reason]);
rxrpc: Add a tracepoint to log received ACK packets Add a tracepoint to log information from received ACK packets. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 09:49:13 +00:00
rxrpc: Fix RTT determination to use any ACK as a source Fix RTT determination to be able to use any type of ACK as the response from which RTT can be calculated provided its ack.serial is non-zero and matches the serial number of an outgoing DATA or ACK packet. This shouldn't be limited to REQUESTED-type ACKs as these can have other types substituted for them for things like duplicate or out-of-order packets. Fixes: 4700c4d80b7b ("rxrpc: Fix loss of RTT samples due to interposed ACK") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:58 +00:00
if (acked_serial != 0) {
switch (ack.reason) {
case RXRPC_ACK_PING_RESPONSE:
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc: Fix RTT determination to use any ACK as a source Fix RTT determination to be able to use any type of ACK as the response from which RTT can be calculated provided its ack.serial is non-zero and matches the serial number of an outgoing DATA or ACK packet. This shouldn't be limited to REQUESTED-type ACKs as these can have other types substituted for them for things like duplicate or out-of-order packets. Fixes: 4700c4d80b7b ("rxrpc: Fix loss of RTT samples due to interposed ACK") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:58 +00:00
rxrpc_rtt_rx_ping_response);
break;
case RXRPC_ACK_REQUESTED:
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc_rtt_rx_requested_ack);
break;
default:
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc_rtt_rx_other_ack);
break;
}
rxrpc: Fix loss of RTT samples due to interposed ACK The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-19 22:29:16 +00:00
}
rxrpc: Send pings to get RTT data Send a PING ACK packet to the peer when we get a new incoming call from a peer we don't have a record for. The PING RESPONSE ACK packet will tell us the following about the peer: (1) its receive window size (2) its MTU sizes (3) its support for jumbo DATA packets (4) if it supports slow start (similar to RFC 5681) (5) an estimate of the RTT This is necessary because the peer won't normally send us an ACK until it gets to the Rx phase and we send it a packet, but we would like to know some of this information before we start sending packets. A pair of tracepoints are added so that RTT determination can be observed. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-21 23:29:31 +00:00
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
/* If we get an EXCEEDS_WINDOW ACK from the server, it probably
* indicates that the client address changed due to NAT. The server
* lost the call because it switched to a different peer.
*/
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (unlikely(ack.reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
first_soft_ack == 1 &&
prev_pkt == 0 &&
rxrpc_is_client_call(call)) {
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
0, -ENETRESET);
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
goto send_response;
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
}
/* If we get an OUT_OF_SEQUENCE ACK from the server, that can also
* indicate a change of address. However, we can retransmit the call
* if we still have it buffered to the beginning.
*/
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (unlikely(ack.reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
first_soft_ack == 1 &&
prev_pkt == 0 &&
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
call->acks_hard_ack == 0 &&
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
rxrpc_is_client_call(call)) {
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
0, -ENETRESET);
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
goto send_response;
afs: Adjust ACK interpretation to try and cope with NAT If a client's address changes, say if it is NAT'd, this can disrupt an in progress operation. For most operations, this is not much of a problem, but StoreData can be different as some servers modify the target file as the data comes in, so if a store request is disrupted, the file can get corrupted on the server. The problem is that the server doesn't recognise packets that come after the change of address as belonging to the original client and will bounce them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if the packet number falls within the initial sequence number window of a call or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting it. In both cases, firstPacket will be 1 and previousPacket will be 0 in the ACK information. Fix this by the following means: (1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1 and previousPacket as 0, assume this indicates that the server saw the incoming packets from a different peer and thus as a different call. Fail the call with error -ENETRESET. (2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the ACK packet will cause it to get retransmitted, so the call will just be repeated. (3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of the operation. (4) Prioritise the error code over things like -ECONNRESET as the server did actually respond. (5) Make writeback treat -ENETRESET as a retryable error and make it redirty all the pages involved in a write so that the VM will retry. Note that there is still a circumstance that I can't easily deal with: if the operation is fully received and processed by the server, but the reply is lost due to address change. There's no way to know if the op happened. We can examine the server, but a conflicting change could have been made by a third party - and we can't tell the difference. In such a case, a message like: kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a) will be logged to dmesg on the next op to touch the file and the client will reset the inode state, including invalidating clean parts of the pagecache. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1 Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 07:45:55 +00:00
}
rxrpc: Fix detection of out of order acks The rxrpc packet serial number cannot be safely used to compute out of order ack packets for several reasons: 1. The allocation of serial numbers cannot be assumed to imply the order by which acks are populated and transmitted. In some rxrpc implementations, delayed acks and ping acks are transmitted asynchronously to the receipt of data packets and so may be transmitted out of order. As a result, they can race with idle acks. 2. Serial numbers are allocated by the rxrpc connection and not the call and as such may wrap independently if multiple channels are in use. In any case, what matters is whether the ack packet provides new information relating to the bounds of the window (the firstPacket and previousPacket in the ACK data). Fix this by discarding packets that appear to wind back the window bounds rather than on serial number procession. Fixes: 298bc15b2079 ("rxrpc: Only take the rwind and mtu values from latest ACK") Signed-off-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 15:34:16 +00:00
/* Discard any out-of-order or duplicate ACKs (outside lock). */
rxrpc: Fix ack discard The Rx protocol has a "previousPacket" field in it that is not handled in the same way by all protocol implementations. Sometimes it contains the serial number of the last DATA packet received, sometimes the sequence number of the last DATA packet received and sometimes the highest sequence number so far received. AF_RXRPC is using this to weed out ACKs that are out of date (it's possible for ACK packets to get reordered on the wire), but this does not work with OpenAFS which will just stick the sequence number of the last packet seen into previousPacket. The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are timing out when partly sent. A trace was captured, with an additional tracepoint to show ACKs being discarded in rxrpc_input_ack(). Here's an excerpt showing the problem. 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09 A DATA packet with sequence number 00024499 has been transmitted (the "q=" field). ... 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2 The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence number 00024499, but did see seq 0002449a (previousPacket, shown as "p=", skipped the number, but firstPacket, "f=", which shows the bottom of the window is set at that point). 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS* The packet has been retransmitted. Retransmission recurs until the peer says it got the packet. 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6 More OOS ACKs indicate that the other packets that are already in the transmission pipeline are being received. The specific-ACK list is up to 6 ACKs and NAKs. ... 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS* 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32 At this point, the server's receive window is full (n=32) with presumably 1 NAK'd packet and 31 ACK'd packets. We can't transmit any more packets. 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS* 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25 And now we've received an ACK indicating that a DATA retransmission was received. 7 packets have been processed (the occupied part of the window moved, as indicated by f= and n=). 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8 However, the DLY ACK gets discarded because its previousPacket has gone backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the ACK at 52873.293850). We then end up in a continuous cycle of retransmit/discard. kafs fails to update its window because it's discarding the ACKs and can't transmit an extra packet that would clear the issue because the window is full. OpenAFS doesn't change the previousPacket value in the ACKs because no new DATA packets are received with a different previousPacket number. Fix this by altering the discard check to only discard an ACK based on previousPacket if there was no advance in the firstPacket. This allows us to transmit a new packet which will cause previousPacket to advance in the next ACK. The check, however, needs to allow for the possibility that previousPacket may actually have had the serial number placed in it instead - in which case it will go outside the window and we should ignore it. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-29 22:48:43 +00:00
if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
rxrpc: Keep the ACK serial in a var in rxrpc_input_ack() Keep the ACK serial number in a variable in rxrpc_input_ack() as it's used frequently. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20 13:12:33 +00:00
trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
rxrpc: Fix overlapping ACK accounting Fix accidental overlapping of Rx-phase ACK accounting with Tx-phase ACK accounting through variables shared between the two. call->acks_* members refer to ACKs received in the Tx phase and call->ackr_* members to ACKs sent/to be sent during the Rx phase. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 08:03:18 +00:00
first_soft_ack, call->acks_first_seq,
prev_pkt, call->acks_prev_seq);
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
goto send_response;
rxrpc: Trace discarded ACKs Add a tracepoint to track received ACKs that are discarded due to being outside of the Tx window. Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-28 21:06:54 +00:00
}
rxrpc: Fix the packet reception routine The rxrpc_input_packet() function and its call tree was built around the assumption that data_ready() handler called from UDP to inform a kernel service that there is data to be had was non-reentrant. This means that certain locking could be dispensed with. This, however, turns out not to be the case with a multi-queue network card that can deliver packets to multiple cpus simultaneously. Each of those cpus can be in the rxrpc_input_packet() function at the same time. Fix by adding or changing some structure members: (1) Add peer->rtt_input_lock to serialise access to the RTT buffer. (2) Make conn->service_id into a 32-bit variable so that it can be cmpxchg'd on all arches. (3) Add call->input_lock to serialise access to the Rx/Tx state. Note that although the Rx and Tx states are (almost) entirely separate, there's no point completing the separation and having separate locks since it's a bi-phasal RPC protocol rather than a bi-direction streaming protocol. Data transmission and data reception do not take place simultaneously on any particular call. and making the following functional changes: (1) In rxrpc_input_data(), hold call->input_lock around the core to prevent simultaneous producing of packets into the Rx ring and updating of tracking state for a particular call. (2) In rxrpc_input_ping_response(), only read call->ping_serial once, and check it before checking RXRPC_CALL_PINGING as that's a cheaper test. The bit test and bit clear can then be combined. No further locking is needed here. (3) In rxrpc_input_ack(), take call->input_lock after we've parsed much of the ACK packet. The superseded ACK check is then done both before and after the lock is taken. The handing of ackinfo data is split, parsing before the lock is taken and processing with it held. This is keyed on rxMTU being non-zero. Congestion management is also done within the locked section. (4) In rxrpc_input_ackall(), take call->input_lock around the Tx window rotation. The ACKALL packet carries no information and is only really useful after all packets have been transmitted since it's imprecise. (5) In rxrpc_input_implicit_end_call(), we use rx->incoming_lock to prevent calls being simultaneously implicitly ended on two cpus and also to prevent any races with incoming call setup. (6) In rxrpc_input_packet(), use cmpxchg() to effect the service upgrade on a connection. It is only permitted to happen once for a connection. (7) In rxrpc_new_incoming_call(), we have to recheck the routing inside rx->incoming_lock to see if someone else set up the call, connection or peer whilst we were getting there. We can't trust the values from the earlier routing check unless we pin refs on them - which we want to avoid. Further, we need to allow for an incoming call to have its state changed on another CPU between us making it live and us adjusting it because the conn is now in the RXRPC_CONN_SERVICE state. (8) In rxrpc_peer_add_rtt(), take peer->rtt_input_lock around the access to the RTT buffer. Don't need to lock around setting peer->rtt. For reference, the inventory of state-accessing or state-altering functions used by the packet input procedure is: > rxrpc_input_packet() * PACKET CHECKING * ROUTING > rxrpc_post_packet_to_local() > rxrpc_find_connection_rcu() - uses RCU > rxrpc_lookup_peer_rcu() - uses RCU > rxrpc_find_service_conn_rcu() - uses RCU > idr_find() - uses RCU * CONNECTION-LEVEL PROCESSING - Service upgrade - Can only happen once per conn ! Changed to use cmpxchg > rxrpc_post_packet_to_conn() - Setting conn->hi_serial - Probably safe not using locks - Maybe use cmpxchg * CALL-LEVEL PROCESSING > Old-call checking > rxrpc_input_implicit_end_call() > rxrpc_call_completed() > rxrpc_queue_call() ! Need to take rx->incoming_lock > __rxrpc_disconnect_call() > rxrpc_notify_socket() > rxrpc_new_incoming_call() - Uses rx->incoming_lock for the entire process - Might be able to drop this earlier in favour of the call lock > rxrpc_incoming_call() ! Conflicts with rxrpc_input_implicit_end_call() > rxrpc_send_ping() - Don't need locks to check rtt state > rxrpc_propose_ACK * PACKET DISTRIBUTION > rxrpc_input_call_packet() > rxrpc_input_data() * QUEUE DATA PACKET ON CALL > rxrpc_reduce_call_timer() - Uses timer_reduce() ! Needs call->input_lock() > rxrpc_receiving_reply() ! Needs locking around ack state > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_proto_abort() > rxrpc_input_dup_data() - Fills the Rx buffer - rxrpc_propose_ACK() - rxrpc_notify_socket() > rxrpc_input_ack() * APPLY ACK PACKET TO CALL AND DISCARD PACKET > rxrpc_input_ping_response() - Probably doesn't need any extra locking ! Need READ_ONCE() on call->ping_serial > rxrpc_input_check_for_lost_ack() - Takes call->lock to consult Tx buffer > rxrpc_peer_add_rtt() ! Needs to take a lock (peer->rtt_input_lock) ! Could perhaps manage with cmpxchg() and xadd() instead > rxrpc_input_requested_ack - Consults Tx buffer ! Probably needs a lock > rxrpc_peer_add_rtt() > rxrpc_propose_ack() > rxrpc_input_ackinfo() - Changes call->tx_winsize ! Use cmpxchg to handle change ! Should perhaps track serial number - Uses peer->lock to record MTU specification changes > rxrpc_proto_abort() ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_input_soft_acks() - Consults the Tx buffer > rxrpc_congestion_management() - Modifies the Tx annotations ! Needs call->input_lock() > rxrpc_queue_call() > rxrpc_input_abort() * APPLY ABORT PACKET TO CALL AND DISCARD PACKET > rxrpc_set_call_completion() > rxrpc_notify_socket() > rxrpc_input_ackall() * APPLY ACKALL PACKET TO CALL AND DISCARD PACKET ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_reject_packet() There are some functions used by the above that queue the packet, after which the procedure is terminated: - rxrpc_post_packet_to_local() - local->event_queue is an sk_buff_head - local->processor is a work_struct - rxrpc_post_packet_to_conn() - conn->rx_queue is an sk_buff_head - conn->processor is a work_struct - rxrpc_reject_packet() - local->reject_queue is an sk_buff_head - local->processor is a work_struct And some that offload processing to process context: - rxrpc_notify_socket() - Uses RCU lock - Uses call->notify_lock to call call->notify_rx - Uses call->recvmsg_lock to queue recvmsg side - rxrpc_queue_call() - call->processor is a work_struct - rxrpc_propose_ACK() - Uses call->lock to wrap __rxrpc_propose_ACK() And a bunch that complete a call, all of which use call->state_lock to protect the call state: - rxrpc_call_completed() - rxrpc_set_call_completion() - rxrpc_abort_call() - rxrpc_proto_abort() - Also uses rxrpc_queue_call() Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:25 +00:00
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
trailer.maxMTU = 0;
rxrpc: The offset field in struct rxrpc_skb_priv is unnecessary The offset field in struct rxrpc_skb_priv is unnecessary as the value can always be calculated. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 12:26:03 +00:00
ioffset = offset + nr_acks + 3;
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
if (skb->len >= ioffset + sizeof(trailer) &&
skb_copy_bits(skb, ioffset, &trailer, sizeof(trailer)) < 0)
return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_trailer);
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
if (nr_acks > 0)
skb_condense(skb);
rxrpc: Fix the packet reception routine The rxrpc_input_packet() function and its call tree was built around the assumption that data_ready() handler called from UDP to inform a kernel service that there is data to be had was non-reentrant. This means that certain locking could be dispensed with. This, however, turns out not to be the case with a multi-queue network card that can deliver packets to multiple cpus simultaneously. Each of those cpus can be in the rxrpc_input_packet() function at the same time. Fix by adding or changing some structure members: (1) Add peer->rtt_input_lock to serialise access to the RTT buffer. (2) Make conn->service_id into a 32-bit variable so that it can be cmpxchg'd on all arches. (3) Add call->input_lock to serialise access to the Rx/Tx state. Note that although the Rx and Tx states are (almost) entirely separate, there's no point completing the separation and having separate locks since it's a bi-phasal RPC protocol rather than a bi-direction streaming protocol. Data transmission and data reception do not take place simultaneously on any particular call. and making the following functional changes: (1) In rxrpc_input_data(), hold call->input_lock around the core to prevent simultaneous producing of packets into the Rx ring and updating of tracking state for a particular call. (2) In rxrpc_input_ping_response(), only read call->ping_serial once, and check it before checking RXRPC_CALL_PINGING as that's a cheaper test. The bit test and bit clear can then be combined. No further locking is needed here. (3) In rxrpc_input_ack(), take call->input_lock after we've parsed much of the ACK packet. The superseded ACK check is then done both before and after the lock is taken. The handing of ackinfo data is split, parsing before the lock is taken and processing with it held. This is keyed on rxMTU being non-zero. Congestion management is also done within the locked section. (4) In rxrpc_input_ackall(), take call->input_lock around the Tx window rotation. The ACKALL packet carries no information and is only really useful after all packets have been transmitted since it's imprecise. (5) In rxrpc_input_implicit_end_call(), we use rx->incoming_lock to prevent calls being simultaneously implicitly ended on two cpus and also to prevent any races with incoming call setup. (6) In rxrpc_input_packet(), use cmpxchg() to effect the service upgrade on a connection. It is only permitted to happen once for a connection. (7) In rxrpc_new_incoming_call(), we have to recheck the routing inside rx->incoming_lock to see if someone else set up the call, connection or peer whilst we were getting there. We can't trust the values from the earlier routing check unless we pin refs on them - which we want to avoid. Further, we need to allow for an incoming call to have its state changed on another CPU between us making it live and us adjusting it because the conn is now in the RXRPC_CONN_SERVICE state. (8) In rxrpc_peer_add_rtt(), take peer->rtt_input_lock around the access to the RTT buffer. Don't need to lock around setting peer->rtt. For reference, the inventory of state-accessing or state-altering functions used by the packet input procedure is: > rxrpc_input_packet() * PACKET CHECKING * ROUTING > rxrpc_post_packet_to_local() > rxrpc_find_connection_rcu() - uses RCU > rxrpc_lookup_peer_rcu() - uses RCU > rxrpc_find_service_conn_rcu() - uses RCU > idr_find() - uses RCU * CONNECTION-LEVEL PROCESSING - Service upgrade - Can only happen once per conn ! Changed to use cmpxchg > rxrpc_post_packet_to_conn() - Setting conn->hi_serial - Probably safe not using locks - Maybe use cmpxchg * CALL-LEVEL PROCESSING > Old-call checking > rxrpc_input_implicit_end_call() > rxrpc_call_completed() > rxrpc_queue_call() ! Need to take rx->incoming_lock > __rxrpc_disconnect_call() > rxrpc_notify_socket() > rxrpc_new_incoming_call() - Uses rx->incoming_lock for the entire process - Might be able to drop this earlier in favour of the call lock > rxrpc_incoming_call() ! Conflicts with rxrpc_input_implicit_end_call() > rxrpc_send_ping() - Don't need locks to check rtt state > rxrpc_propose_ACK * PACKET DISTRIBUTION > rxrpc_input_call_packet() > rxrpc_input_data() * QUEUE DATA PACKET ON CALL > rxrpc_reduce_call_timer() - Uses timer_reduce() ! Needs call->input_lock() > rxrpc_receiving_reply() ! Needs locking around ack state > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_proto_abort() > rxrpc_input_dup_data() - Fills the Rx buffer - rxrpc_propose_ACK() - rxrpc_notify_socket() > rxrpc_input_ack() * APPLY ACK PACKET TO CALL AND DISCARD PACKET > rxrpc_input_ping_response() - Probably doesn't need any extra locking ! Need READ_ONCE() on call->ping_serial > rxrpc_input_check_for_lost_ack() - Takes call->lock to consult Tx buffer > rxrpc_peer_add_rtt() ! Needs to take a lock (peer->rtt_input_lock) ! Could perhaps manage with cmpxchg() and xadd() instead > rxrpc_input_requested_ack - Consults Tx buffer ! Probably needs a lock > rxrpc_peer_add_rtt() > rxrpc_propose_ack() > rxrpc_input_ackinfo() - Changes call->tx_winsize ! Use cmpxchg to handle change ! Should perhaps track serial number - Uses peer->lock to record MTU specification changes > rxrpc_proto_abort() ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_input_soft_acks() - Consults the Tx buffer > rxrpc_congestion_management() - Modifies the Tx annotations ! Needs call->input_lock() > rxrpc_queue_call() > rxrpc_input_abort() * APPLY ABORT PACKET TO CALL AND DISCARD PACKET > rxrpc_set_call_completion() > rxrpc_notify_socket() > rxrpc_input_ackall() * APPLY ACKALL PACKET TO CALL AND DISCARD PACKET ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_reject_packet() There are some functions used by the above that queue the packet, after which the procedure is terminated: - rxrpc_post_packet_to_local() - local->event_queue is an sk_buff_head - local->processor is a work_struct - rxrpc_post_packet_to_conn() - conn->rx_queue is an sk_buff_head - conn->processor is a work_struct - rxrpc_reject_packet() - local->reject_queue is an sk_buff_head - local->processor is a work_struct And some that offload processing to process context: - rxrpc_notify_socket() - Uses RCU lock - Uses call->notify_lock to call call->notify_rx - Uses call->recvmsg_lock to queue recvmsg side - rxrpc_queue_call() - call->processor is a work_struct - rxrpc_propose_ACK() - Uses call->lock to wrap __rxrpc_propose_ACK() And a bunch that complete a call, all of which use call->state_lock to protect the call state: - rxrpc_call_completed() - rxrpc_set_call_completion() - rxrpc_abort_call() - rxrpc_proto_abort() - Also uses rxrpc_queue_call() Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:25 +00:00
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
if (call->cong_last_nack) {
since = rxrpc_input_check_prev_ack(call, &summary, first_soft_ack);
rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
call->cong_last_nack = NULL;
} else {
summary.nr_new_acks = first_soft_ack - call->acks_first_seq;
call->acks_lowest_nak = first_soft_ack + nr_acks;
since = first_soft_ack;
}
rxrpc: Only take the rwind and mtu values from latest ACK Move the out-of-order and duplicate ACK packet check to before the call to rxrpc_input_ackinfo() so that the receive window size and MTU size are only checked in the latest ACK packet and don't regress. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:11 +00:00
call->acks_latest_ts = skb->tstamp;
rxrpc: Fix overlapping ACK accounting Fix accidental overlapping of Rx-phase ACK accounting with Tx-phase ACK accounting through variables shared between the two. call->acks_* members refer to ACKs received in the Tx phase and call->ackr_* members to ACKs sent/to be sent during the Rx phase. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-21 08:03:18 +00:00
call->acks_first_seq = first_soft_ack;
call->acks_prev_seq = prev_pkt;
rxrpc: Fix detection of out of order acks The rxrpc packet serial number cannot be safely used to compute out of order ack packets for several reasons: 1. The allocation of serial numbers cannot be assumed to imply the order by which acks are populated and transmitted. In some rxrpc implementations, delayed acks and ping acks are transmitted asynchronously to the receipt of data packets and so may be transmitted out of order. As a result, they can race with idle acks. 2. Serial numbers are allocated by the rxrpc connection and not the call and as such may wrap independently if multiple channels are in use. In any case, what matters is whether the ack packet provides new information relating to the bounds of the window (the firstPacket and previousPacket in the ACK data). Fix this by discarding packets that appear to wind back the window bounds rather than on serial number procession. Fixes: 298bc15b2079 ("rxrpc: Only take the rwind and mtu values from latest ACK") Signed-off-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 15:34:16 +00:00
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
switch (ack.reason) {
case RXRPC_ACK_PING:
break;
default:
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
if (acked_serial && after(acked_serial, call->acks_highest_serial))
rxrpc: Save last ACK's SACK table rather than marking txbufs Improve the tracking of which packets need to be transmitted by saving the last ACK packet that we receive that has a populated soft-ACK table rather than marking packets. Then we can step through the soft-ACK table and look at the packets we've transmitted beyond that to determine which packets we might want to retransmit. We also look at the highest serial number that has been acked to try and guess which packets we've transmitted the peer is likely to have seen. If necessary, we send a ping to retrieve that number. One downside that might be a problem is that we can't then compare the previous acked/unacked state so easily in rxrpc_input_soft_acks() - which is a potential problem for the slow-start algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-05-07 09:06:13 +00:00
call->acks_highest_serial = acked_serial;
break;
}
rxrpc: Track highest acked serial Keep track of the highest DATA serial number that has been acked by the peer for future purposes. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-04-28 07:30:47 +00:00
rxrpc: Only take the rwind and mtu values from latest ACK Move the out-of-order and duplicate ACK packet check to before the call to rxrpc_input_ackinfo() so that the receive window size and MTU size are only checked in the latest ACK packet and don't regress. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:11 +00:00
/* Parse rwind and mtu sizes if provided. */
rxrpc: Fix the names of the fields in the ACK trailer struct From AFS-3.3 a trailer containing extra info was added to the ACK packet format - but AF_RXRPC has the names of some of the fields mixed up compared to other AFS implementations. Rename the struct and the fields to make them match. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-26 16:17:03 +00:00
if (trailer.maxMTU)
rxrpc_input_ack_trailer(call, skb, &trailer);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (first_soft_ack == 0)
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/* Ignore ACKs unless we are or have just been transmitting. */
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
switch (__rxrpc_call_state(call)) {
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
case RXRPC_CALL_SERVER_SEND_REPLY:
case RXRPC_CALL_SERVER_AWAIT_ACK:
break;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
default:
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
goto send_response;
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (before(hard_ack, call->acks_hard_ack) ||
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
after(hard_ack, call->tx_top))
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window);
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (nr_acks > call->tx_top - hard_ack)
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (after(hard_ack, call->acks_hard_ack)) {
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack);
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
goto send_response;
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
}
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
if (nr_acks > 0) {
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (offset > (int)skb->len - nr_acks)
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack);
rxrpc: Fix counting of new acks and nacks Fix the counting of new acks and nacks when parsing a packet - something that is used in congestion control. As the code stands, it merely notes if there are any nacks whereas what we really should do is compare the previous SACK table to the new one, assuming we get two successive ACK packets with nacks in them. However, we really don't want to do that if we can avoid it as the tables might not correspond directly as one may be shifted from the other - something that will only get harder to deal with once extended ACK tables come into full use (with a capacity of up to 8192). Instead, count the number of nacks shifted out of the old SACK, the number of nacks retained in the portion still active and the number of new acks and nacks in the new table then calculate what we need. Note this ends up a bit of an estimate as the Rx protocol allows acks to be withdrawn by the receiver and packets requested to be retransmitted. Fixes: d57a3a151660 ("rxrpc: Save last ACK's SACK table rather than marking txbufs") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-02 15:19:16 +00:00
rxrpc_input_soft_acks(call, &summary, skb, first_soft_ack, since);
rxrpc_get_skb(skb, rxrpc_skb_get_last_nack);
call->cong_last_nack = skb;
rxrpc: Pass the last Tx packet marker in the annotation buffer When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 11:39:22 +00:00
}
rxrpc: Don't use a ring buffer for call Tx queue Change the way the Tx queueing works to make the following ends easier to achieve: (1) The filling of packets, the encryption of packets and the transmission of packets can be handled in parallel by separate threads, rather than rxrpc_sendmsg() allocating, filling, encrypting and transmitting each packet before moving onto the next one. (2) Get rid of the fixed-size ring which sets a hard limit on the number of packets that can be retained in the ring. This allows the number of packets to increase without having to allocate a very large ring or having variable-sized rings. [Note: the downside of this is that it's then less efficient to locate a packet for retransmission as we then have to step through a list and examine each buffer in the list.] (3) Allow the filler/encrypter to run ahead of the transmission window. (4) Make it easier to do zero copy UDP from the packet buffers. (5) Make it easier to do zero copy from userspace to the packet buffers - and thence to UDP (only if for unauthenticated connections). To that end, the following changes are made: (1) Use the new rxrpc_txbuf struct instead of sk_buff for keeping packets to be transmitted in. This allows them to be placed on multiple queues simultaneously. An sk_buff isn't really necessary as it's never passed on to lower-level networking code. (2) Keep the transmissable packets in a linked list on the call struct rather than in a ring. As a consequence, the annotation buffer isn't used either; rather a flag is set on the packet to indicate ackedness. (3) Use the RXRPC_CALL_TX_LAST flag to indicate that the last packet to be transmitted has been queued. Add RXRPC_CALL_TX_ALL_ACKED to indicate that all packets up to and including the last got hard acked. (4) Wire headers are now stored in the txbuf rather than being concocted on the stack and they're stored immediately before the data, thereby allowing zerocopy of a single span. (5) Don't bother with instant-resend on transmission failure; rather, leave it for a timer or an ACK packet to trigger. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-03-31 22:55:08 +00:00
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
rxrpc: Only ping for lost reply in client call When a reply is deemed lost, we send a ping to find out the other end received all the request data packets we sent. This should be limited to client calls and we shouldn't do this on service calls. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
summary.nr_acks == call->tx_top - hard_ack &&
rxrpc_is_client_call(call))
rxrpc: Allocate ACK records at proposal and queue for transmission Allocate rxrpc_txbuf records for ACKs and put onto a queue for the transmitter thread to dispatch. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-30 21:48:13 +00:00
rxrpc_propose_ping(call, ack_serial,
rxrpc_propose_ack_ping_for_lost_reply);
rxrpc: Implement slow-start Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:27 +00:00
rxrpc: Fix the packet reception routine The rxrpc_input_packet() function and its call tree was built around the assumption that data_ready() handler called from UDP to inform a kernel service that there is data to be had was non-reentrant. This means that certain locking could be dispensed with. This, however, turns out not to be the case with a multi-queue network card that can deliver packets to multiple cpus simultaneously. Each of those cpus can be in the rxrpc_input_packet() function at the same time. Fix by adding or changing some structure members: (1) Add peer->rtt_input_lock to serialise access to the RTT buffer. (2) Make conn->service_id into a 32-bit variable so that it can be cmpxchg'd on all arches. (3) Add call->input_lock to serialise access to the Rx/Tx state. Note that although the Rx and Tx states are (almost) entirely separate, there's no point completing the separation and having separate locks since it's a bi-phasal RPC protocol rather than a bi-direction streaming protocol. Data transmission and data reception do not take place simultaneously on any particular call. and making the following functional changes: (1) In rxrpc_input_data(), hold call->input_lock around the core to prevent simultaneous producing of packets into the Rx ring and updating of tracking state for a particular call. (2) In rxrpc_input_ping_response(), only read call->ping_serial once, and check it before checking RXRPC_CALL_PINGING as that's a cheaper test. The bit test and bit clear can then be combined. No further locking is needed here. (3) In rxrpc_input_ack(), take call->input_lock after we've parsed much of the ACK packet. The superseded ACK check is then done both before and after the lock is taken. The handing of ackinfo data is split, parsing before the lock is taken and processing with it held. This is keyed on rxMTU being non-zero. Congestion management is also done within the locked section. (4) In rxrpc_input_ackall(), take call->input_lock around the Tx window rotation. The ACKALL packet carries no information and is only really useful after all packets have been transmitted since it's imprecise. (5) In rxrpc_input_implicit_end_call(), we use rx->incoming_lock to prevent calls being simultaneously implicitly ended on two cpus and also to prevent any races with incoming call setup. (6) In rxrpc_input_packet(), use cmpxchg() to effect the service upgrade on a connection. It is only permitted to happen once for a connection. (7) In rxrpc_new_incoming_call(), we have to recheck the routing inside rx->incoming_lock to see if someone else set up the call, connection or peer whilst we were getting there. We can't trust the values from the earlier routing check unless we pin refs on them - which we want to avoid. Further, we need to allow for an incoming call to have its state changed on another CPU between us making it live and us adjusting it because the conn is now in the RXRPC_CONN_SERVICE state. (8) In rxrpc_peer_add_rtt(), take peer->rtt_input_lock around the access to the RTT buffer. Don't need to lock around setting peer->rtt. For reference, the inventory of state-accessing or state-altering functions used by the packet input procedure is: > rxrpc_input_packet() * PACKET CHECKING * ROUTING > rxrpc_post_packet_to_local() > rxrpc_find_connection_rcu() - uses RCU > rxrpc_lookup_peer_rcu() - uses RCU > rxrpc_find_service_conn_rcu() - uses RCU > idr_find() - uses RCU * CONNECTION-LEVEL PROCESSING - Service upgrade - Can only happen once per conn ! Changed to use cmpxchg > rxrpc_post_packet_to_conn() - Setting conn->hi_serial - Probably safe not using locks - Maybe use cmpxchg * CALL-LEVEL PROCESSING > Old-call checking > rxrpc_input_implicit_end_call() > rxrpc_call_completed() > rxrpc_queue_call() ! Need to take rx->incoming_lock > __rxrpc_disconnect_call() > rxrpc_notify_socket() > rxrpc_new_incoming_call() - Uses rx->incoming_lock for the entire process - Might be able to drop this earlier in favour of the call lock > rxrpc_incoming_call() ! Conflicts with rxrpc_input_implicit_end_call() > rxrpc_send_ping() - Don't need locks to check rtt state > rxrpc_propose_ACK * PACKET DISTRIBUTION > rxrpc_input_call_packet() > rxrpc_input_data() * QUEUE DATA PACKET ON CALL > rxrpc_reduce_call_timer() - Uses timer_reduce() ! Needs call->input_lock() > rxrpc_receiving_reply() ! Needs locking around ack state > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_proto_abort() > rxrpc_input_dup_data() - Fills the Rx buffer - rxrpc_propose_ACK() - rxrpc_notify_socket() > rxrpc_input_ack() * APPLY ACK PACKET TO CALL AND DISCARD PACKET > rxrpc_input_ping_response() - Probably doesn't need any extra locking ! Need READ_ONCE() on call->ping_serial > rxrpc_input_check_for_lost_ack() - Takes call->lock to consult Tx buffer > rxrpc_peer_add_rtt() ! Needs to take a lock (peer->rtt_input_lock) ! Could perhaps manage with cmpxchg() and xadd() instead > rxrpc_input_requested_ack - Consults Tx buffer ! Probably needs a lock > rxrpc_peer_add_rtt() > rxrpc_propose_ack() > rxrpc_input_ackinfo() - Changes call->tx_winsize ! Use cmpxchg to handle change ! Should perhaps track serial number - Uses peer->lock to record MTU specification changes > rxrpc_proto_abort() ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_input_soft_acks() - Consults the Tx buffer > rxrpc_congestion_management() - Modifies the Tx annotations ! Needs call->input_lock() > rxrpc_queue_call() > rxrpc_input_abort() * APPLY ABORT PACKET TO CALL AND DISCARD PACKET > rxrpc_set_call_completion() > rxrpc_notify_socket() > rxrpc_input_ackall() * APPLY ACKALL PACKET TO CALL AND DISCARD PACKET ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_reject_packet() There are some functions used by the above that queue the packet, after which the procedure is terminated: - rxrpc_post_packet_to_local() - local->event_queue is an sk_buff_head - local->processor is a work_struct - rxrpc_post_packet_to_conn() - conn->rx_queue is an sk_buff_head - conn->processor is a work_struct - rxrpc_reject_packet() - local->reject_queue is an sk_buff_head - local->processor is a work_struct And some that offload processing to process context: - rxrpc_notify_socket() - Uses RCU lock - Uses call->notify_lock to call call->notify_rx - Uses call->recvmsg_lock to queue recvmsg side - rxrpc_queue_call() - call->processor is a work_struct - rxrpc_propose_ACK() - Uses call->lock to wrap __rxrpc_propose_ACK() And a bunch that complete a call, all of which use call->state_lock to protect the call state: - rxrpc_call_completed() - rxrpc_set_call_completion() - rxrpc_abort_call() - rxrpc_proto_abort() - Also uses rxrpc_queue_call() Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:25 +00:00
rxrpc_congestion_management(call, skb, &summary, acked_serial);
rxrpc: Defer the response to a PING ACK until we've parsed it Defer the generation of a PING RESPONSE ACK in response to a PING ACK until we've parsed the PING ACK so that we pick up any changes to the packet queue so that we can update ackinfo. This is also applied to an ACK generated in response to an ACK with the REQUEST_ACK flag set. Note that whilst the problem was added in commit 248f219cb8bc, it didn't really matter at that point because the ACK was proposed in softirq mode and generated asynchronously later in process context, taking the latest values at the time. But this fix is only needed since the move to parse incoming packets in an I/O thread rather than in softirq and generate the ACK at point of proposal (b0346843b1076b34a0278ff601f8f287535cb064). Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-16 13:12:59 +00:00
send_response:
if (ack.reason == RXRPC_ACK_PING)
rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, ack_serial,
rxrpc_propose_ack_respond_to_ping);
else if (sp->hdr.flags & RXRPC_REQUEST_ACK)
rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, ack_serial,
rxrpc_propose_ack_respond_to_ack);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
/*
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
* Process an ACKALL packet.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Generate a summary of the ACK state for later use Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 17:05:26 +00:00
struct rxrpc_ack_summary summary = { 0 };
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() We should only call the function to end a call's Tx phase if we rotated the marked-last packet out of the transmission buffer. Make rxrpc_rotate_tx_window() return an indication of whether it just rotated the packet marked as the last out of the transmit buffer, carrying the information out of the locked section in that function. We can then check the return value instead of examining RXRPC_CALL_TX_LAST. Fixes: 70790dbe3f66 ("rxrpc: Pass the last Tx packet marker in the annotation buffer") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:01 +00:00
if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall);
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
}
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
/*
rxrpc: Trace received aborts Add a tracepoint (rxrpc_rx_abort) to record received aborts. Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 09:12:00 +00:00
* Process an ABORT packet directed at a call.
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
*/
static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Extract the code from a received ABORT packet much earlier Extract the code from a received rx ABORT packet much earlier and in a single place and harmonise the responses to malformed ABORT packets. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-14 12:21:32 +00:00
trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority);
rxrpc: Trace received aborts Add a tracepoint (rxrpc_rx_abort) to record received aborts. Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 09:12:00 +00:00
rxrpc: Fix missing notification Under some circumstances, rxrpc will fail a transmit a packet through the underlying UDP socket (ie. UDP sendmsg returns an error). This may result in a call getting stuck. In the instance being seen, where AFS tries to send a probe to the Volume Location server, tracepoints show the UDP Tx failure (in this case returing error 99 EADDRNOTAVAIL) and then nothing more: afs_make_vl_call: c=0000015d VL.GetCapabilities rxrpc_call: c=0000015d NWc u=1 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000dd89ee8a rxrpc_call: c=0000015d Gus u=2 sp=rxrpc_new_client_call+0x14f/0x580 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d SEE u=2 sp=rxrpc_activate_one_channel+0x7b/0x1c0 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d CON u=2 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000e20e4b08 rxrpc_tx_fail: c=0000015d r=1 ret=-99 CallDataNofrag The problem is that if the initial packet fails and the retransmission timer hasn't been started, the call is set to completed and an error is returned from rxrpc_send_data_packet() to rxrpc_queue_packet(). Though rxrpc_instant_resend() is called, this does nothing because the call is marked completed. So rxrpc_notify_socket() isn't called and the error is passed back up to rxrpc_send_data(), rxrpc_kernel_send_data() and thence to afs_make_call() and afs_vl_get_capabilities() where it is simply ignored because it is assumed that the result of a probe will be collected asynchronously. Fileserver probing is similarly affected via afs_fs_get_capabilities(). Fix this by always issuing a notification in __rxrpc_set_call_completion() if it shifts a call to the completed state, even if an error is also returned to the caller through the function return value. Also put in a little bit of optimisation to avoid taking the call state_lock and disabling softirqs if the call is already in the completed state and remove some now redundant rxrpc_notify_socket() calls. Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Reported-by: Gerry Seidman <gerry@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
2020-06-03 21:21:16 +00:00
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
rxrpc: Extract the code from a received ABORT packet much earlier Extract the code from a received rx ABORT packet much earlier and in a single place and harmonise the responses to malformed ABORT packets. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-14 12:21:32 +00:00
skb->priority, -ECONNABORTED);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
/*
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
* Process an incoming call packet.
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
*/
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
{
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
unsigned long timo;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
af_rxrpc: Keep rxrpc_call pointers in a hashtable Keep track of rxrpc_call structures in a hashtable so they can be found directly from the network parameters which define the call. This allows incoming packets to be routed directly to a call without walking through hierarchy of peer -> transport -> connection -> call and all the spinlocks that that entailed. Signed-off-by: Tim Smith <tim@electronghost.co.uk> Signed-off-by: David Howells <dhowells@redhat.com>
2014-03-03 23:04:45 +00:00
_enter("%p,%p", call, skb);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
if (sp->hdr.serviceId != call->dest_srx.srx_service)
call->dest_srx.srx_service = sp->hdr.serviceId;
if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
call->rx_serial = sp->hdr.serial;
if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
timo = READ_ONCE(call->next_rx_timo);
if (timo) {
rxrpc: Strip barriers and atomics off of timer tracking Strip the atomic ops and barriering off of the call timer tracking as this is handled solely within the I/O thread, except for expect_term_by which is set by sendmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-30 16:39:15 +00:00
unsigned long now = jiffies;
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
rxrpc: Strip barriers and atomics off of timer tracking Strip the atomic ops and barriering off of the call timer tracking as this is handled solely within the I/O thread, except for expect_term_by which is set by sendmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org
2024-01-30 16:39:15 +00:00
call->expect_rx_by = now + timo;
rxrpc_reduce_call_timer(call, call->expect_rx_by, now,
rxrpc: Fix call timeouts Fix the rxrpc call expiration timeouts and make them settable from userspace. By analogy with other rx implementations, there should be three timeouts: (1) "Normal timeout" This is set for all calls and is triggered if we haven't received any packets from the peer in a while. It is measured from the last time we received any packet on that call. This is not reset by any connection packets (such as CHALLENGE/RESPONSE packets). If a service operation takes a long time, the server should generate PING ACKs at a duration that's substantially less than the normal timeout so is to keep both sides alive. This is set at 1/6 of normal timeout. (2) "Idle timeout" This is set only for a service call and is triggered if we stop receiving the DATA packets that comprise the request data. It is measured from the last time we received a DATA packet. (3) "Hard timeout" This can be set for a call and specified the maximum lifetime of that call. It should not be specified by default. Some operations (such as volume transfer) take a long time. Allow userspace to set/change the timeouts on a call with sendmsg, using a control message: RXRPC_SET_CALL_TIMEOUTS The data to the message is a number of 32-bit words, not all of which need be given: u32 hard_timeout; /* sec from first packet */ u32 idle_timeout; /* msec from packet Rx */ u32 normal_timeout; /* msec from data Rx */ This can be set in combination with any other sendmsg() that affects a call. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-24 10:18:41 +00:00
rxrpc_timer_set_for_normal);
}
rxrpc: Clean up whitespace Clean up some whitespace from rxrpc. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-29 14:25:50 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_DATA:
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_input_data(call, skb);
rxrpc: Calls should only have one terminal state Condense the terminal states of a call state machine to a single state, plus a separate completion type value. The value is then set, along with error and abort code values, only when the call is transitioned to the completion state. Helpers are provided to simplify this. Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 08:49:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_PACKET_TYPE_ACK:
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_input_ack(call, skb);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_PACKET_TYPE_BUSY:
/* Just ignore BUSY packets from the server; the retry and
* lifespan timers will take care of business. BUSY packets
* from the client don't make sense.
*/
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_PACKET_TYPE_ABORT:
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_input_abort(call, skb);
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
case RXRPC_PACKET_TYPE_ACKALL:
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
return rxrpc_input_ackall(call, skb);
rxrpc: Calls should only have one terminal state Condense the terminal states of a call state machine to a single state, plus a separate completion type value. The value is then set, along with error and abort code values, only when the call is transitioned to the completion state. Helpers are provided to simplify this. Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 08:49:28 +00:00
rxrpc: Rewrite the data and ack handling code Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 10:10:12 +00:00
default:
break;
[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve answers to AFS clients. KerberosIV security is fully supported. The patches and some example test programs can be found in: http://people.redhat.com/~dhowells/rxrpc/ This will eventually replace the old implementation of kernel-only RxRPC currently resident in net/rxrpc/. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 22:48:28 +00:00
}
}
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
/*
rxrpc: Fix the packet reception routine The rxrpc_input_packet() function and its call tree was built around the assumption that data_ready() handler called from UDP to inform a kernel service that there is data to be had was non-reentrant. This means that certain locking could be dispensed with. This, however, turns out not to be the case with a multi-queue network card that can deliver packets to multiple cpus simultaneously. Each of those cpus can be in the rxrpc_input_packet() function at the same time. Fix by adding or changing some structure members: (1) Add peer->rtt_input_lock to serialise access to the RTT buffer. (2) Make conn->service_id into a 32-bit variable so that it can be cmpxchg'd on all arches. (3) Add call->input_lock to serialise access to the Rx/Tx state. Note that although the Rx and Tx states are (almost) entirely separate, there's no point completing the separation and having separate locks since it's a bi-phasal RPC protocol rather than a bi-direction streaming protocol. Data transmission and data reception do not take place simultaneously on any particular call. and making the following functional changes: (1) In rxrpc_input_data(), hold call->input_lock around the core to prevent simultaneous producing of packets into the Rx ring and updating of tracking state for a particular call. (2) In rxrpc_input_ping_response(), only read call->ping_serial once, and check it before checking RXRPC_CALL_PINGING as that's a cheaper test. The bit test and bit clear can then be combined. No further locking is needed here. (3) In rxrpc_input_ack(), take call->input_lock after we've parsed much of the ACK packet. The superseded ACK check is then done both before and after the lock is taken. The handing of ackinfo data is split, parsing before the lock is taken and processing with it held. This is keyed on rxMTU being non-zero. Congestion management is also done within the locked section. (4) In rxrpc_input_ackall(), take call->input_lock around the Tx window rotation. The ACKALL packet carries no information and is only really useful after all packets have been transmitted since it's imprecise. (5) In rxrpc_input_implicit_end_call(), we use rx->incoming_lock to prevent calls being simultaneously implicitly ended on two cpus and also to prevent any races with incoming call setup. (6) In rxrpc_input_packet(), use cmpxchg() to effect the service upgrade on a connection. It is only permitted to happen once for a connection. (7) In rxrpc_new_incoming_call(), we have to recheck the routing inside rx->incoming_lock to see if someone else set up the call, connection or peer whilst we were getting there. We can't trust the values from the earlier routing check unless we pin refs on them - which we want to avoid. Further, we need to allow for an incoming call to have its state changed on another CPU between us making it live and us adjusting it because the conn is now in the RXRPC_CONN_SERVICE state. (8) In rxrpc_peer_add_rtt(), take peer->rtt_input_lock around the access to the RTT buffer. Don't need to lock around setting peer->rtt. For reference, the inventory of state-accessing or state-altering functions used by the packet input procedure is: > rxrpc_input_packet() * PACKET CHECKING * ROUTING > rxrpc_post_packet_to_local() > rxrpc_find_connection_rcu() - uses RCU > rxrpc_lookup_peer_rcu() - uses RCU > rxrpc_find_service_conn_rcu() - uses RCU > idr_find() - uses RCU * CONNECTION-LEVEL PROCESSING - Service upgrade - Can only happen once per conn ! Changed to use cmpxchg > rxrpc_post_packet_to_conn() - Setting conn->hi_serial - Probably safe not using locks - Maybe use cmpxchg * CALL-LEVEL PROCESSING > Old-call checking > rxrpc_input_implicit_end_call() > rxrpc_call_completed() > rxrpc_queue_call() ! Need to take rx->incoming_lock > __rxrpc_disconnect_call() > rxrpc_notify_socket() > rxrpc_new_incoming_call() - Uses rx->incoming_lock for the entire process - Might be able to drop this earlier in favour of the call lock > rxrpc_incoming_call() ! Conflicts with rxrpc_input_implicit_end_call() > rxrpc_send_ping() - Don't need locks to check rtt state > rxrpc_propose_ACK * PACKET DISTRIBUTION > rxrpc_input_call_packet() > rxrpc_input_data() * QUEUE DATA PACKET ON CALL > rxrpc_reduce_call_timer() - Uses timer_reduce() ! Needs call->input_lock() > rxrpc_receiving_reply() ! Needs locking around ack state > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_proto_abort() > rxrpc_input_dup_data() - Fills the Rx buffer - rxrpc_propose_ACK() - rxrpc_notify_socket() > rxrpc_input_ack() * APPLY ACK PACKET TO CALL AND DISCARD PACKET > rxrpc_input_ping_response() - Probably doesn't need any extra locking ! Need READ_ONCE() on call->ping_serial > rxrpc_input_check_for_lost_ack() - Takes call->lock to consult Tx buffer > rxrpc_peer_add_rtt() ! Needs to take a lock (peer->rtt_input_lock) ! Could perhaps manage with cmpxchg() and xadd() instead > rxrpc_input_requested_ack - Consults Tx buffer ! Probably needs a lock > rxrpc_peer_add_rtt() > rxrpc_propose_ack() > rxrpc_input_ackinfo() - Changes call->tx_winsize ! Use cmpxchg to handle change ! Should perhaps track serial number - Uses peer->lock to record MTU specification changes > rxrpc_proto_abort() ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_input_soft_acks() - Consults the Tx buffer > rxrpc_congestion_management() - Modifies the Tx annotations ! Needs call->input_lock() > rxrpc_queue_call() > rxrpc_input_abort() * APPLY ABORT PACKET TO CALL AND DISCARD PACKET > rxrpc_set_call_completion() > rxrpc_notify_socket() > rxrpc_input_ackall() * APPLY ACKALL PACKET TO CALL AND DISCARD PACKET ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_reject_packet() There are some functions used by the above that queue the packet, after which the procedure is terminated: - rxrpc_post_packet_to_local() - local->event_queue is an sk_buff_head - local->processor is a work_struct - rxrpc_post_packet_to_conn() - conn->rx_queue is an sk_buff_head - conn->processor is a work_struct - rxrpc_reject_packet() - local->reject_queue is an sk_buff_head - local->processor is a work_struct And some that offload processing to process context: - rxrpc_notify_socket() - Uses RCU lock - Uses call->notify_lock to call call->notify_rx - Uses call->recvmsg_lock to queue recvmsg side - rxrpc_queue_call() - call->processor is a work_struct - rxrpc_propose_ACK() - Uses call->lock to wrap __rxrpc_propose_ACK() And a bunch that complete a call, all of which use call->state_lock to protect the call state: - rxrpc_call_completed() - rxrpc_set_call_completion() - rxrpc_abort_call() - rxrpc_proto_abort() - Also uses rxrpc_queue_call() Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:25 +00:00
* Handle a new service call on a channel implicitly completing the preceding
* call on that channel. This does not apply to client conns.
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
*
* TODO: If callNumber > call_id + 1, renegotiate security.
*/
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb)
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
{
rxrpc: Remove call->state_lock All the setters of call->state are now in the I/O thread and thus the state lock is now unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-27 10:25:55 +00:00
switch (__rxrpc_call_state(call)) {
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
case RXRPC_CALL_SERVER_AWAIT_ACK:
rxrpc_call_completed(call);
treewide: Use fallthrough pseudo-keyword Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 22:36:59 +00:00
fallthrough;
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
case RXRPC_CALL_COMPLETE:
break;
default:
rxrpc: Tidy up abort generation infrastructure Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-10-06 20:45:42 +00:00
rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN,
rxrpc_eproto_improper_term);
rxrpc: Fix the packet reception routine The rxrpc_input_packet() function and its call tree was built around the assumption that data_ready() handler called from UDP to inform a kernel service that there is data to be had was non-reentrant. This means that certain locking could be dispensed with. This, however, turns out not to be the case with a multi-queue network card that can deliver packets to multiple cpus simultaneously. Each of those cpus can be in the rxrpc_input_packet() function at the same time. Fix by adding or changing some structure members: (1) Add peer->rtt_input_lock to serialise access to the RTT buffer. (2) Make conn->service_id into a 32-bit variable so that it can be cmpxchg'd on all arches. (3) Add call->input_lock to serialise access to the Rx/Tx state. Note that although the Rx and Tx states are (almost) entirely separate, there's no point completing the separation and having separate locks since it's a bi-phasal RPC protocol rather than a bi-direction streaming protocol. Data transmission and data reception do not take place simultaneously on any particular call. and making the following functional changes: (1) In rxrpc_input_data(), hold call->input_lock around the core to prevent simultaneous producing of packets into the Rx ring and updating of tracking state for a particular call. (2) In rxrpc_input_ping_response(), only read call->ping_serial once, and check it before checking RXRPC_CALL_PINGING as that's a cheaper test. The bit test and bit clear can then be combined. No further locking is needed here. (3) In rxrpc_input_ack(), take call->input_lock after we've parsed much of the ACK packet. The superseded ACK check is then done both before and after the lock is taken. The handing of ackinfo data is split, parsing before the lock is taken and processing with it held. This is keyed on rxMTU being non-zero. Congestion management is also done within the locked section. (4) In rxrpc_input_ackall(), take call->input_lock around the Tx window rotation. The ACKALL packet carries no information and is only really useful after all packets have been transmitted since it's imprecise. (5) In rxrpc_input_implicit_end_call(), we use rx->incoming_lock to prevent calls being simultaneously implicitly ended on two cpus and also to prevent any races with incoming call setup. (6) In rxrpc_input_packet(), use cmpxchg() to effect the service upgrade on a connection. It is only permitted to happen once for a connection. (7) In rxrpc_new_incoming_call(), we have to recheck the routing inside rx->incoming_lock to see if someone else set up the call, connection or peer whilst we were getting there. We can't trust the values from the earlier routing check unless we pin refs on them - which we want to avoid. Further, we need to allow for an incoming call to have its state changed on another CPU between us making it live and us adjusting it because the conn is now in the RXRPC_CONN_SERVICE state. (8) In rxrpc_peer_add_rtt(), take peer->rtt_input_lock around the access to the RTT buffer. Don't need to lock around setting peer->rtt. For reference, the inventory of state-accessing or state-altering functions used by the packet input procedure is: > rxrpc_input_packet() * PACKET CHECKING * ROUTING > rxrpc_post_packet_to_local() > rxrpc_find_connection_rcu() - uses RCU > rxrpc_lookup_peer_rcu() - uses RCU > rxrpc_find_service_conn_rcu() - uses RCU > idr_find() - uses RCU * CONNECTION-LEVEL PROCESSING - Service upgrade - Can only happen once per conn ! Changed to use cmpxchg > rxrpc_post_packet_to_conn() - Setting conn->hi_serial - Probably safe not using locks - Maybe use cmpxchg * CALL-LEVEL PROCESSING > Old-call checking > rxrpc_input_implicit_end_call() > rxrpc_call_completed() > rxrpc_queue_call() ! Need to take rx->incoming_lock > __rxrpc_disconnect_call() > rxrpc_notify_socket() > rxrpc_new_incoming_call() - Uses rx->incoming_lock for the entire process - Might be able to drop this earlier in favour of the call lock > rxrpc_incoming_call() ! Conflicts with rxrpc_input_implicit_end_call() > rxrpc_send_ping() - Don't need locks to check rtt state > rxrpc_propose_ACK * PACKET DISTRIBUTION > rxrpc_input_call_packet() > rxrpc_input_data() * QUEUE DATA PACKET ON CALL > rxrpc_reduce_call_timer() - Uses timer_reduce() ! Needs call->input_lock() > rxrpc_receiving_reply() ! Needs locking around ack state > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_proto_abort() > rxrpc_input_dup_data() - Fills the Rx buffer - rxrpc_propose_ACK() - rxrpc_notify_socket() > rxrpc_input_ack() * APPLY ACK PACKET TO CALL AND DISCARD PACKET > rxrpc_input_ping_response() - Probably doesn't need any extra locking ! Need READ_ONCE() on call->ping_serial > rxrpc_input_check_for_lost_ack() - Takes call->lock to consult Tx buffer > rxrpc_peer_add_rtt() ! Needs to take a lock (peer->rtt_input_lock) ! Could perhaps manage with cmpxchg() and xadd() instead > rxrpc_input_requested_ack - Consults Tx buffer ! Probably needs a lock > rxrpc_peer_add_rtt() > rxrpc_propose_ack() > rxrpc_input_ackinfo() - Changes call->tx_winsize ! Use cmpxchg to handle change ! Should perhaps track serial number - Uses peer->lock to record MTU specification changes > rxrpc_proto_abort() ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_input_soft_acks() - Consults the Tx buffer > rxrpc_congestion_management() - Modifies the Tx annotations ! Needs call->input_lock() > rxrpc_queue_call() > rxrpc_input_abort() * APPLY ABORT PACKET TO CALL AND DISCARD PACKET > rxrpc_set_call_completion() > rxrpc_notify_socket() > rxrpc_input_ackall() * APPLY ACKALL PACKET TO CALL AND DISCARD PACKET ! Need to take call->input_lock > rxrpc_rotate_tx_window() > rxrpc_end_tx_phase() > rxrpc_reject_packet() There are some functions used by the above that queue the packet, after which the procedure is terminated: - rxrpc_post_packet_to_local() - local->event_queue is an sk_buff_head - local->processor is a work_struct - rxrpc_post_packet_to_conn() - conn->rx_queue is an sk_buff_head - conn->processor is a work_struct - rxrpc_reject_packet() - local->reject_queue is an sk_buff_head - local->processor is a work_struct And some that offload processing to process context: - rxrpc_notify_socket() - Uses RCU lock - Uses call->notify_lock to call call->notify_rx - Uses call->recvmsg_lock to queue recvmsg side - rxrpc_queue_call() - call->processor is a work_struct - rxrpc_propose_ACK() - Uses call->lock to wrap __rxrpc_propose_ACK() And a bunch that complete a call, all of which use call->state_lock to protect the call state: - rxrpc_call_completed() - rxrpc_set_call_completion() - rxrpc_abort_call() - rxrpc_proto_abort() - Also uses rxrpc_queue_call() Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-08 14:46:25 +00:00
trace_rxrpc_improper_term(call);
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
break;
}
rxrpc: Make the I/O thread take over the call and local processor work Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2020-01-23 13:13:41 +00:00
rxrpc_input_call_event(call, skb);
rxrpc: Partially handle OpenAFS's improper termination of calls OpenAFS doesn't always correctly terminate client calls that it makes - this includes calls the OpenAFS servers make to the cache manager service. It should end the client call with either: (1) An ACK that has firstPacket set to one greater than the seq number of the reply DATA packet with the LAST_PACKET flag set (thereby hard-ACK'ing all packets). nAcks should be 0 and acks[] should be empty (ie. no soft-ACKs). (2) An ACKALL packet. OpenAFS, though, may send an ACK packet with firstPacket set to the last seq number or less and soft-ACKs listed for all packets up to and including the last DATA packet. The transmitter, however, is obliged to keep the call live and the soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is permitted to drop any merely soft-ACK'd packet and request retransmission by sending an ACK packet with a NACK in it. Further, OpenAFS will also terminate a client call by beginning the next client call on the same connection channel. This implicitly completes the previous call. This patch handles implicit ACK of a call on a channel by the reception of the first packet of the next call on that channel. If another call doesn't come along to implicitly ACK a call, then we have to time the call out. There are some bugs there that will be addressed in subsequent patches. Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 07:11:49 +00:00
}
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