[3.13.y.z extended stable] Patch "net: sctp: Don't transition to PF state when transport has exhausted 'Path.Max.Retrans'." has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: sctp: Don't transition to PF state when transport has exhausted 'Path.Max.Retrans'.

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b05b818111f2686ee6b1db2cb782439d1c473b75 Mon Sep 17 00:00:00 2001
From: Karl Heiss <kheiss at gmail.com>
Date: Fri, 25 Apr 2014 14:26:30 -0400
Subject: net: sctp: Don't transition to PF state when transport has exhausted
 'Path.Max.Retrans'.

[ Upstream commit 8c2eab9097dba50bcd73ed4632baccc3f34857f9 ]

Don't transition to the PF state on every strike after 'Path.Max.Retrans'.
Per draft-ietf-tsvwg-sctp-failover-03 Section 5.1.6:

   Additional (PMR - PFMR) consecutive timeouts on a PF destination
   confirm the path failure, upon which the destination transitions to the
   Inactive state.  As described in [RFC4960], the sender (i) SHOULD notify
   ULP about this state transition, and (ii) transmit heartbeats to the
   Inactive destination at a lower frequency as described in Section 8.3 of
   [RFC4960].

This also prevents sending SCTP_ADDR_UNREACHABLE to the user as the state
bounces between SCTP_INACTIVE and SCTP_PF for each subsequent strike.

Signed-off-by: Karl Heiss <kheiss at gmail.com>
Acked-by: Vlad Yasevich <vyasevich at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sctp/sm_sideeffect.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index 04b1398..aa4ea94 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -497,11 +497,10 @@ static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,

 	/* If the transport error count is greater than the pf_retrans
 	 * threshold, and less than pathmaxrtx, and if the current state
-	 * is not SCTP_UNCONFIRMED, then mark this transport as Partially
-	 * Failed, see SCTP Quick Failover Draft, section 5.1
+	 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
+	 * see SCTP Quick Failover Draft, section 5.1
 	 */
-	if ((transport->state != SCTP_PF) &&
-	   (transport->state != SCTP_UNCONFIRMED) &&
+	if ((transport->state == SCTP_ACTIVE) &&
 	   (asoc->pf_retrans < transport->pathmaxrxt) &&
 	   (transport->error_count > asoc->pf_retrans)) {

--
1.9.1