linux/net/sctp
Neil Horman 3b885787ea net: Generalize socket rx gap / receive queue overflow cmsg
Create a new socket level option to report number of queue overflows

Recently I augmented the AF_PACKET protocol to report the number of frames lost
on the socket receive queue between any two enqueued frames.  This value was
exported via a SOL_PACKET level cmsg.  AFter I completed that work it was
requested that this feature be generalized so that any datagram oriented socket
could make use of this option.  As such I've created this patch, It creates a
new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a
SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue
overflowed between any two given frames.  It also augments the AF_PACKET
protocol to take advantage of this new feature (as it previously did not touch
sk->sk_drops, which this patch uses to record the overflow count).  Tested
successfully by me.

Notes:

1) Unlike my previous patch, this patch simply records the sk_drops value, which
is not a number of drops between packets, but rather a total number of drops.
Deltas must be computed in user space.

2) While this patch currently works with datagram oriented protocols, it will
also be accepted by non-datagram oriented protocols. I'm not sure if thats
agreeable to everyone, but my argument in favor of doing so is that, for those
protocols which aren't applicable to this option, sk_drops will always be zero,
and reporting no drops on a receive queue that isn't used for those
non-participating protocols seems reasonable to me.  This also saves us having
to code in a per-protocol opt in mechanism.

3) This applies cleanly to net-next assuming that commit
977750076d (my af packet cmsg patch) is reverted

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-12 13:26:31 -07:00
..
associola.c sctp: Get rid of an extra routing lookup when adding a transport. 2009-09-04 18:21:01 -04:00
auth.c fix similar typos to successfull 2009-01-08 08:31:15 -08:00
bind_addr.c sctp: Sysctl configuration for IPv4 Address Scoping 2009-09-04 18:21:01 -04:00
chunk.c sctp: Don't do NAGLE delay on large writes that were fragmented small 2009-09-04 18:20:59 -04:00
command.c [SCTP]: Remove sctp_add_cmd_sf wrapper bloat 2008-03-27 17:54:29 -07:00
debug.c net: mark read-only arrays as const 2009-08-05 10:42:58 -07:00
endpointola.c net: fix sctp breakage 2009-03-18 19:12:42 -07:00
input.c sctp: Use frag list abstraction interfaces. 2009-06-09 00:24:07 -07:00
inqueue.c [SCTP]: Stop claiming that this is a "reference implementation" 2008-02-05 10:59:07 -05:00
ipv6.c net: constify struct inet6_protocol 2009-09-14 17:03:05 -07:00
Kconfig sctp: Don't abort initialization when CONFIG_PROC_FS=n 2008-07-18 23:03:44 -07:00
Makefile sctp: Don't abort initialization when CONFIG_PROC_FS=n 2008-07-18 23:03:44 -07:00
objcnt.c [NET]: Fix heavy stack usage in seq_file output routines. 2008-04-24 01:02:16 -07:00
output.c sctp: remove dup code in net/sctp/output.c 2009-09-04 18:21:02 -04:00
outqueue.c sctp: Failover transmitted list on transport delete 2009-09-04 18:21:00 -04:00
primitive.c [SCTP]: Stop claiming that this is a "reference implementation" 2008-02-05 10:59:07 -05:00
proc.c sctp: use proc_create() 2009-09-04 18:20:58 -04:00
protocol.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
sm_make_chunk.c sctp: update the route for non-active transports after addresses are added 2009-09-04 18:20:55 -04:00
sm_sideeffect.c sctp: Try not to change a_rwnd when faking a SACK from SHUTDOWN. 2009-09-04 18:20:59 -04:00
sm_statefuns.c sctp: Catch bogus stream sequence numbers 2009-09-04 18:21:03 -04:00
sm_statetable.c sctp: fix a typo in net/sctp/sm_statetable.c 2009-06-03 09:14:45 -04:00
socket.c net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
ssnmap.c [SCTP]: Stop claiming that this is a "reference implementation" 2008-02-05 10:59:07 -05:00
sysctl.c sctp: Sysctl configuration for IPv4 Address Scoping 2009-09-04 18:21:01 -04:00
transport.c sctp: Clear fast_recovery on the transport when T3 timer expires. 2009-09-04 18:20:58 -04:00
tsnmap.c trivial: fix then -> than typos in comments and documentation 2009-01-06 11:28:06 +01:00
ulpevent.c sctp: Use frag list abstraction interfaces. 2009-06-09 00:24:07 -07:00
ulpqueue.c net: Remove __skb_insert() calls outside of skbuff internals. 2008-09-21 21:28:51 -07:00