linux/net/sctp
Doug Graham af87b823ca sctp: Fix piggybacked ACKs
This patch corrects the conditions under which a SACK will be piggybacked
on a DATA packet.  The previous condition was incorrect due to a
misinterpretation of RFC 4960 and/or RFC 2960.  Specifically, the
following paragraph from section 6.2 had not been implemented correctly:

   Before an endpoint transmits a DATA chunk, if any received DATA
   chunks have not been acknowledged (e.g., due to delayed ack), the
   sender should create a SACK and bundle it with the outbound DATA
   chunk, as long as the size of the final SCTP packet does not exceed
   the current MTU.  See Section 6.2.

When about to send a DATA chunk, the code now checks to see if the SACK
timer is running.  If it is, we know we have a SACK to send to the
peer, so we append the SACK (assuming available space in the packet)
and turn off the timer.  For a simple request-response scenario, this
will result in the SACK being bundled with the response, meaning the
the SACK is received quickly by the client, and also meaning that no
separate SACK packet needs to be sent by the server to acknowledge the
request.  Prior to this patch, a separate SACK packet would have been
sent by the server SCTP only after its delayed-ACK timer had expired
(usually 200ms).  This is wasteful of bandwidth, and can also have a
major negative impact on performance due the interaction of delayed ACKs
with the Nagle algorithm.

Signed-off-by: Doug Graham <dgraham@nortel.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
2009-09-04 18:20:55 -04:00
..
associola.c sctp: release cached route when the transport goes down. 2009-09-04 18:20:55 -04:00
auth.c fix similar typos to successfull 2009-01-08 08:31:15 -08:00
bind_addr.c sctp: try harder to figure out address family when checking wildcards 2008-10-01 11:33:06 -04:00
chunk.c SCTP: fix wrong debug counting of datamsg 2008-04-10 01:57:24 -07:00
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 ipv6: Use correct data types for ICMPv6 type and code 2009-06-23 04:31:07 -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: Fix piggybacked ACKs 2009-09-04 18:20:55 -04:00
outqueue.c sctp: fix to send FORWARD-TSN chunk only if peer has such capable 2009-03-13 11:37:58 -07:00
primitive.c [SCTP]: Stop claiming that this is a "reference implementation" 2008-02-05 10:59:07 -05:00
proc.c sctp: remove sctp_assoc_proc_exit() 2008-07-22 14:21:30 -07:00
protocol.c sctp: fix missing destroy of percpu counter variable in sctp_proc_exit() 2009-08-09 21:45:43 -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: fix to choose alternate destination when retransmit ASCONF chunk 2009-06-03 09:14:46 -04:00
sm_statefuns.c sctp: fix panic when T4-rto timer expire on removed transport 2009-06-03 09:14:46 -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 sctp: fix warning at inet_sock_destruct() while release sctp socket 2009-07-06 12:47:08 -07:00
ssnmap.c [SCTP]: Stop claiming that this is a "reference implementation" 2008-02-05 10:59:07 -05:00
sysctl.c sctp: fix sack_timeout sysctl min and max types 2009-06-03 09:14:46 -04:00
transport.c sctp: use time_before or time_after for comparing jiffies 2009-03-02 22:49:18 -08:00
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