[PATCH] sctp: set association state to established in dupcook_a handler

From: xufengzhang.main
Date: Wed Jan 23 2013 - 02:36:04 EST


From: Xufeng Zhang <xufeng.zhang@xxxxxxxxxxxxx>

While sctp handling a duplicate COOKIE-ECHO and the action is
'Association restart', sctp_sf_do_dupcook_a() will processing
the unexpected COOKIE-ECHO for peer restart, but it does not set
the association state to SCTP_STATE_ESTABLISHED, so the association
could stuck in SCTP_STATE_SHUTDOWN_PENDING state forever.
This violates the sctp specification:
RFC 4960 5.2.4. Handle a COOKIE ECHO when a TCB Exists
Action
A) In this case, the peer may have restarted. .....
After this, the endpoint shall enter the ESTABLISHED state.

Fix this problem by adding a SCTP_CMD_NEW_STATE cmd to the command
list so as to set the restart association to SCTP_STATE_ESTABLISHED
state properly.

Signed-off-by: Xufeng Zhang <xufeng.zhang@xxxxxxxxxxxxx>
---
net/sctp/sm_statefuns.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 618ec7e..528f1c8 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -1779,6 +1779,8 @@ static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,

/* Update the content of current association. */
sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
return SCTP_DISPOSITION_CONSUME;
--
1.7.0.2

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