linux.git/net/sctp/sm_sideeffect.c, branch v4.2

sctp: donot reset the overall_error_count in SHUTDOWN_RECEIVE state

2015-08-28T00:11:44+00:00

Commit f8d960524328 ("sctp: Enforce retransmission limit during shutdown")
fixed a problem with excessive retransmissions in the SHUTDOWN_PENDING by not
resetting the association overall_error_count.  This allowed the association
to better enforce assoc.max_retrans limit.

However, the same issue still exists when the association is in SHUTDOWN_RECEIVED
state.  In this state, HB-ACKs will continue to reset the overall_error_count
for the association would extend the lifetime of association unnecessarily.

This patch solves this by resetting the overall_error_count whenever the current
state is small then SCTP_STATE_SHUTDOWN_PENDING.  As a small side-effect, we
end up also handling SCTP_STATE_SHUTDOWN_ACK_SENT and SCTP_STATE_SHUTDOWN_SENT
states, but they are not really impacted because we disable Heartbeats in those
states.

Fixes: Commit f8d960524328 ("sctp: Enforce retransmission limit during shutdown")
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

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

2014-04-28T03:41:14+00:00

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

net: sctp: Potentially-Failed state should not be reached from unconfirmed state

2014-02-20T18:24:56+00:00

In current implementation it is possible to reach PF state from unconfirmed.
We can interpret sctp-failover-02 in a way that PF state is meant to be reached
only from active state, in the end, this is when entering PF state makes sense.
Here are few quotes from sctp-failover-02, but regardless of these, same
understanding can be reached from whole section 5:

Section 5.1, quickfailover guide:
    "The PF state is an intermediate state between Active and Failed states."

    "Each time the T3-rtx timer expires on an active or idle
    destination, the error counter of that destination address will
    be incremented.  When the value in the error counter exceeds
    PFMR, the endpoint should mark the destination transport address as PF."

There are several concrete reasons for such interpretation. For start, rfc4960
does not take into concern quickfailover algorithm. Therefore, quickfailover
must comply to 4960. Point where this compliance can be argued is following
behavior:
When PF is entered, association overall error counter is incremented for each
missed HB. This is contradictory to rfc4960, as address, while in unconfirmed
state, is subjected to probing, and while it is probed, it should not increment
association overall error counter. This has as a consequence that we might end
up in situation in which we drop association due path failure on unconfirmed
address, in case we have wrong configuration in a way:
Association.Max.Retrans == Path.Max.Retrans.

Another reason is that entering PF from unconfirmed will cause a loss of address
confirmed event when address is once (if) confirmed. This is fine from failover
guide point of view, but it is not consistent with behavior preceding failover
implementation and recommendation from 4960:

5.4.  Path Verification
   Whenever a path is confirmed, an indication MAY be given to the upper
   layer.

Signed-off-by: Matija Glavinic Pecotic 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: remove macros sctp_bh_[un]lock_sock

2014-01-22T02:41:36+00:00

Redefined bh_[un]lock_sock to sctp_bh[un]lock_sock for user
space friendly code which we haven't use in years, so removing them.

Signed-off-by: Wang Weidong 
Signed-off-by: David S. Miller

sctp: fix checkpatch errors with space required or prohibited

2013-12-26T18:47:47+00:00

fix checkpatch errors while the space is required or prohibited
to the "=,()++..."

Acked-by: Neil Horman 
Signed-off-by: Wang Weidong 
Signed-off-by: David S. Miller

sctp: remove casting from function calls through ops structure

2013-12-22T23:04:28+00:00

remove the unnecessary cast.

Signed-off-by: Wang Weidong 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

sctp: Fix FSF address in file headers

2013-12-06T17:37:56+00:00

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL  so that we do not have to keep
updating the header comments anytime the address changes.

CC: Vlad Yasevich 
CC: Neil Horman 
Signed-off-by: Jeff Kirsher 
Signed-off-by: David S. Miller

net: sctp: do not trigger BUG_ON in sctp_cmd_delete_tcb

2013-11-04T05:46:44+00:00

Introduced in f9e42b853523 ("net: sctp: sideeffect: throw BUG if
primary_path is NULL"), we intended to find a buggy assoc that's
part of the assoc hash table with a primary_path that is NULL.
However, we better remove the BUG_ON for now and find a more
suitable place to assert for these things as Mark reports that
this also triggers the bug when duplication cookie processing
happens, and the assoc is not part of the hash table (so all
good in this case). Such a situation can for example easily be
reproduced by:

  tc qdisc add dev eth0 root handle 1: prio bands 2 priomap 1 1 1 1 1 1
  tc qdisc add dev eth0 parent 1:2 handle 20: netem loss 20%
  tc filter add dev eth0 protocol ip parent 1: prio 2 u32 match ip \
            protocol 132 0xff match u8 0x0b 0xff at 32 flowid 1:2

This drops 20% of COOKIE-ACK packets. After some follow-up
discussion with Vlad we came to the conclusion that for now we
should still better remove this BUG_ON() assertion, and come up
with two follow-ups later on, that is, i) find a more suitable
place for this assertion, and possibly ii) have a special
allocator/initializer for such kind of temporary assocs.

Reported-by: Mark Thomas 
Signed-off-by: Vlad Yasevich 
Signed-off-by: Daniel Borkmann 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

net: sctp: trivial: update bug report in header comment

2013-08-09T18:33:02+00:00

With the restructuring of the lksctp.org site, we only allow bug
reports through the SCTP mailing list linux-sctp@vger.kernel.org,
not via SF, as SF is only used for web hosting and nothing more.
While at it, also remove the obvious statement that bugs will be
fixed and incooperated into the kernel.

Signed-off-by: Daniel Borkmann 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

net: sctp: trivial: update mailing list address

2013-07-25T00:53:38+00:00

The SCTP mailing list address to send patches or questions
to is linux-sctp@vger.kernel.org and not
lksctp-developers@lists.sourceforge.net anymore. Therefore,
update all occurences.

Signed-off-by: Daniel Borkmann 
Acked-by: Neil Horman 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller