[PATCH] sctp: Fix to start T5-shutdown-guard timer while enter SHUTDOWN-SENT

[Wei Yongjun <yjwei@cn.fujitsu.com>]

RFC 4960: Section 9.2
The sender of the SHUTDOWN MAY also start an overall guard timer
'T5-shutdown-guard' to bound the overall time for the shutdown
sequence.  At the expiration of this timer, the sender SHOULD abort
the association by sending an ABORT chunk.  If the 'T5-shutdown-
guard' timer is used, it SHOULD be set to the recommended value of 5
times 'RTO.Max'.

The timer 'T5-shutdown-guard' is used to counter the overall time
for shutdown sequence, and it's start by the sender of the SHUTDOWN.
So timer 'T5-shutdown-guard' should be start when we send the first
SHUTDOWN chunk and enter the SHUTDOWN-SENT state, not start when we
receipt of the SHUTDOWN primitive and enter SHUTDOWN-PENDING state.

If 'T5-shutdown-guard' timer is start at SHUTDOWN-PENDING state, the
association may be ABORT while data is still transmitting.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 net/sctp/sm_statefuns.c  |   14 +++++++-------
 net/sctp/sm_statetable.c |    2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 8848d32..c4eea16 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -4517,13 +4517,6 @@ sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 			SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
 
-	/* sctpimpguide-05 Section 2.12.2
-	 * The sender of the SHUTDOWN MAY also start an overall guard timer
-	 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
-	 */
-	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
-			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
-
 	disposition = SCTP_DISPOSITION_CONSUME;
 	if (sctp_outq_is_empty(&asoc->outqueue)) {
 		disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
@@ -4968,6 +4961,13 @@ sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
 	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
 			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
 
+	/* RFC 4960 Section 9.2
+	 * The sender of the SHUTDOWN MAY also start an overall guard timer
+	 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
+	 */
+	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
 	if (asoc->autoclose)
 		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index d991237..dd4ddc4 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -897,7 +897,7 @@ static const sctp_sm_table_entry_t other_event_table[SCTP_NUM_OTHER_TYPES][SCTP_
 	/* SCTP_STATE_ESTABLISHED */ \
 	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
 	/* SCTP_STATE_SHUTDOWN_PENDING */ \
-	TYPE_SCTP_FUNC(sctp_sf_t5_timer_expire), \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
 	/* SCTP_STATE_SHUTDOWN_SENT */ \
 	TYPE_SCTP_FUNC(sctp_sf_t5_timer_expire), \
 	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
-- 
1.5.3.8