sctp: set association state to established in dupcook_a handler
authorXufeng Zhang <xufeng.zhang@windriver.com>
Wed, 23 Jan 2013 16:44:34 +0000 (16:44 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 28 Jan 2013 00:32:23 +0000 (19:32 -0500)
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>
net/sctp/sm_statefuns.c

index 618ec7e216cae9bb17038c07ff5d87a75c8f6208..5131fcfedb03c0b09e8c7e451341cebd82e49692 100644 (file)
@@ -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));
 
        /* 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_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:
        return SCTP_DISPOSITION_CONSUME;
 
 nomem_ev: