linux.git/net/sctp/outqueue.c, branch v2.6.32

sctp: on T3_RTX retransmit all the in-flight chunks

2009-11-29T08:14:02+00:00

When retransmitting due to T3 timeout, retransmit all the
in-flight chunks for the corresponding  transport/path, including
chunks sent less then 1 rto ago.
This is the correct behaviour according to rfc4960 section 6.3.3
E3 and
"Note: Any DATA chunks that were sent to the address for which the
 T3-rtx timer expired but did not fit in one MTU (rule E3 above)
 should be marked for retransmission and sent as soon as cwnd
 allows (normally, when a SACK arrives). ".

This fixes problems when more then one path is present and the T3
retransmission of the first chunk that timeouts stops the T3 timer
for the initial active path, leaving all the other in-flight
chunks waiting forever or until a new chunk is transmitted on the
same path and timeouts (and this will happen only if the cwnd
allows sending new chunks, but since cwnd was dropped to MTU by
the timeout => it will wait until the first heartbeat).

Example: 10 packets in flight, sent at 0.1 s intervals on the
primary path. The primary path is down and the first packet
timeouts. The first packet is retransmitted on another path, the
T3 timer for the primary path is stopped and cwnd is set to MTU.
All the other 9 in-flight packets will not be retransmitted
(unless more new packets are sent on the primary path which depend
on cwnd allowing it, and even in this case the 9 packets will be
retransmitted only after a new packet timeouts which even in the
best case would be more then RTO).

This commit reverts d0ce92910bc04e107b2f3f2048f07e94f570035d and
also removes the now unused transport->last_rto, introduced in
 b6157d8e03e1e780660a328f7183bcbfa4a93a19.

p.s  The problem is not only when multiple paths are there.  It
can happen in a single homed environment.  If the application
stops sending data, it possible to have a hung association.

Signed-off-by: Andrei Pelinescu-Onciul 
Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: Failover transmitted list on transport delete

2009-09-04T22:21:00+00:00

Add-IP feature allows users to delete an active transport.  If that
transport has chunks in flight, those chunks need to be moved to another
transport or association may get into unrecoverable state.

Reported-by: Rafael Laufer 
Signed-off-by: Vlad Yasevich

sctp: fix to send FORWARD-TSN chunk only if peer has such capable

2009-03-13T18:37:58+00:00

RFC3758 Section 3.3.1.  Sending Forward-TSN-Supported param in INIT

   Note that if the endpoint chooses NOT to include the parameter, then
   at no time during the life of the association can it send or process
   a FORWARD TSN.

If peer does not support PR-SCTP capable, don't send FORWARD-TSN chunk
to peer.

Signed-off-by: Wei Yongjun 
Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: use time_before or time_after for comparing jiffies

2009-03-03T06:49:18+00:00

The functions time_before or time_after are more robust
for comparing jiffies against other values.

Signed-off-by: Wei Yongjun 
Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: Correctly start rtx timer on new packet transmissions.

2009-01-22T22:52:43+00:00

Commit 62aeaff5ccd96462b7077046357a6d7886175a57
(sctp: Start T3-RTX timer when fast retransmitting lowest TSN)
introduced a regression where it was possible to forcibly
restart the sctp retransmit timer at the transmission of any
new chunk.  This resulted in much longer timeout times and
sometimes hung sctp connections.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: reduce memory footprint of sctp_chunk structure

2008-10-01T15:33:06+00:00

sctp_chunks should be put on a diet.  This is some of the low hanging
fruit that we can strip out.  Changes all the __s8/__u8 flags to
bitfields.  Saves 12 bytes per chunk.

Signed-off-by: Neil Horman 
Signed-off-by: Vlad Yasevich

sctp: Retransmit list is ineligable for missing indications

2008-10-01T15:33:06+00:00

Chunks placed on the retransmit list are marked as inelegible
for fast retrasnmission.   Since missing indications determine
when fast reransmission is done, there is not point in calling
sctp_mark_missing() on the retransmit list since those chunks
will not be marked.

Signed-off-by: Vlad Yasevich

sctp: Optimize SFR-CACC transport list walking during SACK processing

2008-10-01T15:33:06+00:00

There is a possibility of walking the transport list twice during
SACK processing when doing SFR-CACC algorithm.  We can restructure
the code to only do this once.

Signed-off-by: Vlad Yasevich

sctp: Only mark chunks as missing when there are gaps

2008-10-01T15:33:06+00:00

Frist small step in optimizing SACK processing.   Do not call
sctp_mark_missing() when there are no gaps reported and thus
not missing chunks.

Signed-off-by: Vlad Yasevich

sctp: make sctp_outq_flush() static

2008-07-22T21:20:45+00:00

sctp_outq_flush() can now become static.

Signed-off-by: Adrian Bunk 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller