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d001648ec7
Don't expose skbs to in-kernel users, such as the AFS filesystem, but
instead provide a notification hook the indicates that a call needs
attention and another that indicates that there's a new call to be
collected.
This makes the following possibilities more achievable:
(1) Call refcounting can be made simpler if skbs don't hold refs to calls.
(2) skbs referring to non-data events will be able to be freed much sooner
rather than being queued for AFS to pick up as rxrpc_kernel_recv_data
will be able to consult the call state.
(3) We can shortcut the receive phase when a call is remotely aborted
because we don't have to go through all the packets to get to the one
cancelling the operation.
(4) It makes it easier to do encryption/decryption directly between AFS's
buffers and sk_buffs.
(5) Encryption/decryption can more easily be done in the AFS's thread
contexts - usually that of the userspace process that issued a syscall
- rather than in one of rxrpc's background threads on a workqueue.
(6) AFS will be able to wait synchronously on a call inside AF_RXRPC.
To make this work, the following interface function has been added:
int rxrpc_kernel_recv_data(
struct socket *sock, struct rxrpc_call *call,
void *buffer, size_t bufsize, size_t *_offset,
bool want_more, u32 *_abort_code);
This is the recvmsg equivalent. It allows the caller to find out about the
state of a specific call and to transfer received data into a buffer
piecemeal.
afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction
logic between them. They don't wait synchronously yet because the socket
lock needs to be dealt with.
Five interface functions have been removed:
rxrpc_kernel_is_data_last()
rxrpc_kernel_get_abort_code()
rxrpc_kernel_get_error_number()
rxrpc_kernel_free_skb()
rxrpc_kernel_data_consumed()
As a temporary hack, sk_buffs going to an in-kernel call are queued on the
rxrpc_call struct (->knlrecv_queue) rather than being handed over to the
in-kernel user. To process the queue internally, a temporary function,
temp_deliver_data() has been added. This will be replaced with common code
between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a
future patch.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
47 lines
1.5 KiB
C
47 lines
1.5 KiB
C
/* RxRPC kernel service interface definitions
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _NET_RXRPC_H
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#define _NET_RXRPC_H
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#include <linux/rxrpc.h>
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struct key;
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struct sock;
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struct socket;
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struct rxrpc_call;
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typedef void (*rxrpc_notify_rx_t)(struct sock *, struct rxrpc_call *,
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unsigned long);
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typedef void (*rxrpc_notify_new_call_t)(struct sock *);
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void rxrpc_kernel_new_call_notification(struct socket *,
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rxrpc_notify_new_call_t);
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struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *,
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struct sockaddr_rxrpc *,
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struct key *,
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unsigned long,
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gfp_t,
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rxrpc_notify_rx_t);
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int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
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struct msghdr *, size_t);
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int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
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void *, size_t, size_t *, bool, u32 *);
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void rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *, u32);
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void rxrpc_kernel_end_call(struct socket *, struct rxrpc_call *);
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struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *, unsigned long,
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rxrpc_notify_rx_t);
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int rxrpc_kernel_reject_call(struct socket *);
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void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *,
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struct sockaddr_rxrpc *);
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#endif /* _NET_RXRPC_H */
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