Commit 9839ff0d authored Jan 23, 2013 by Xufeng Zhang Committed by David S. Miller Jan 27, 2013

sctp: set association state to established in dupcook_a handler



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.

To resolve this problem, adding a SCTP_CMD_NEW_STATE cmd to the
command list before SCTP_CMD_REPLY cmd, this will set the restart
association to SCTP_STATE_ESTABLISHED state properly and also avoid
I-bit being set in the DATA chunk header when COOKIE_ACK is bundled
with DATA chunks.

Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 75356a81

net/sctp/sm_statefuns.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1779,8 +1779,10 @@ 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_REPLY, SCTP_CHUNK(repl));
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
		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));
		return SCTP_DISPOSITION_CONSUME;

		nomem_ev:

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