linux/net/rxrpc
David Howells 2cfa227160 rxrpc: Fix the data_ready handler
Fix the rxrpc_data_ready() function to pick up all packets and to not miss
any.  There are two problems:

 (1) The sk_data_ready pointer on the UDP socket is set *after* it is
     bound.  This means that it's open for business before we're ready to
     dequeue packets and there's a tiny window exists in which a packet can
     sneak onto the receive queue, but we never know about it.

     Fix this by setting the pointers on the socket prior to binding it.

 (2) skb_recv_udp() will return an error (such as ENETUNREACH) if there was
     an error on the transmission side, even though we set the
     sk_error_report hook.  Because rxrpc_data_ready() returns immediately
     in such a case, it never actually removes its packet from the receive
     queue.

     Fix this by abstracting out the UDP dequeuing and checksumming into a
     separate function that keeps hammering on skb_recv_udp() until it
     returns -EAGAIN, passing the packets extracted to the remainder of the
     function.

and two potential problems:

 (3) It might be possible in some circumstances or in the future for
     packets to be being added to the UDP receive queue whilst rxrpc is
     running consuming them, so the data_ready() handler might get called
     less often than once per packet.

     Allow for this by fully draining the queue on each call as (2).

 (4) If a packet fails the checksum check, the code currently returns after
     discarding the packet without checking for more.

     Allow for this by fully draining the queue on each call as (2).

Fixes: 17926a7932 ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
2018-10-05 14:21:59 +01:00
..
af_rxrpc.c net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
ar-internal.h rxrpc: Fix some missed refs to init_net 2018-10-05 14:21:59 +01:00
call_accept.c rxrpc: Fix some missed refs to init_net 2018-10-05 14:21:59 +01:00
call_event.c rxrpc: remove redundant variables 'sp' and 'did_discard' 2018-08-01 13:28:23 +01:00
call_object.c rxrpc: Fix some missed refs to init_net 2018-10-05 14:21:59 +01:00
conn_client.c rxrpc: Fix some missed refs to init_net 2018-10-05 14:21:59 +01:00
conn_event.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
conn_object.c rxrpc: Fix error distribution 2018-09-28 10:33:17 +01:00
conn_service.c rxrpc: Fix apparent leak of rxrpc_local objects 2018-03-30 21:05:33 +01:00
input.c rxrpc: Fix the data_ready handler 2018-10-05 14:21:59 +01:00
insecure.c rxrpc: Trace protocol errors in received packets 2017-04-06 11:09:39 +01:00
Kconfig rxrpc: Add config to inject packet loss 2016-09-17 11:24:04 +01:00
key.c rxrpc: Use correct timestamp from Kerberos 5 ticket 2017-08-29 10:55:06 +01:00
local_event.c rxrpc: Trace packet transmission 2018-08-01 13:28:23 +01:00
local_object.c rxrpc: Fix the data_ready handler 2018-10-05 14:21:59 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
misc.c rxrpc: Fix call timeouts 2017-11-24 10:18:41 +00:00
net_ns.c rxrpc: Fix the keepalive generator [ver #2] 2018-08-08 19:10:26 -07:00
output.c rxrpc: Emit BUSY packets when supposed to rather than ABORTs 2018-09-28 10:32:19 +01:00
peer_event.c rxrpc: Fix error distribution 2018-09-28 10:33:17 +01:00
peer_object.c rxrpc: Fix some missed refs to init_net 2018-10-05 14:21:59 +01:00
proc.c rxrpc: Remove set but not used variable 'nowj' 2018-08-02 10:18:20 -07:00
protocol.h rxrpc: Improve up-front incoming packet checking 2018-09-28 10:32:31 +01:00
recvmsg.c rxrpc: Push iov_iter up from rxrpc_kernel_recv_data() to caller 2018-08-03 12:46:20 -07:00
rxkad.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
security.c rxrpc: remove unused static variables 2018-03-30 21:04:44 +01:00
sendmsg.c rxrpc: Fix missing start of call timeout 2018-05-10 23:26:00 +01:00
skbuff.c net: convert sk_buff.users from atomic_t to refcount_t 2017-07-01 07:39:07 -07:00
sysctl.c rxrpc: remove redundant static int 'zero' 2018-08-11 11:25:18 -07:00
utils.c rxrpc: Fix IPv6 support 2017-08-29 10:55:20 +01:00