[SCTP] Send SHUTDOWNs through the same path as the received DATA in

       SHUTDOWN-SENT state. (Ryan Layer)

include/net/sctp/sm.h

@@ -231,7 +231,8 @@ struct sctp_chunk *sctp_make_data_empty(struct sctp_association *,
 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
 				  const __u32);
 struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
-struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc);
+struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
+				      const struct sctp_chunk *chunk);
 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 					  const struct sctp_chunk *);
 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,

net/sctp/sm_make_chunk.c

@@ -667,7 +667,8 @@ struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
 }
 
 /* Make a SHUTDOWN chunk. */
-struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc)
+struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
+				      const struct sctp_chunk *chunk)
 {
 	struct sctp_chunk *retval;
 	sctp_shutdownhdr_t shut;
@@ -683,6 +684,9 @@ struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc)
 
 	retval->subh.shutdown_hdr =
 		sctp_addto_chunk(retval, sizeof(shut), &shut);
+
+	if (chunk)
+		retval->transport = chunk->transport;
 nodata:
 	return retval;
 }

net/sctp/sm_sideeffect.c

@@ -962,7 +962,7 @@ int sctp_cmd_interpreter(sctp_event_t event_type, sctp_subtype_t subtype,
 			asoc->overall_error_count = 0;
 
 			/* Generate a SHUTDOWN chunk.  */
-			new_obj = sctp_make_shutdown(asoc);
+			new_obj = sctp_make_shutdown(asoc, chunk);
 			if (!new_obj)
 				goto nomem;
 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,

net/sctp/sm_statefuns.c

@@ -3862,7 +3862,7 @@ sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
 	 * in the Cumulative TSN Ack field the last sequential TSN it
 	 * has received from the peer.
 	 */
-	reply = sctp_make_shutdown(asoc);
+	reply = sctp_make_shutdown(asoc, NULL);
 	if (!reply)
 		goto nomem;
 
@@ -4179,7 +4179,7 @@ sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
 
 	switch (asoc->state) {
 	case SCTP_STATE_SHUTDOWN_SENT:
-		reply = sctp_make_shutdown(asoc);
+		reply = sctp_make_shutdown(asoc, NULL);
 		break;
 
 	case SCTP_STATE_SHUTDOWN_ACK_SENT: