sctp: Bundle HEAERTBEAT into ASCONF_ACK

With this patch a HEARTBEAT chunk is bundled into the ASCONF-ACK
for ADD IP ADDRESS, confirming the new destination as quickly as
possible.
Signed-off-by: Michio Honda <micchie@sfc.wide.ad.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/structs.h

@@ -1915,6 +1915,7 @@ struct sctp_association {
 	__u32 addip_serial;
 	union sctp_addr *asconf_addr_del_pending;
 	int src_out_of_asoc_ok;
+	struct sctp_transport *new_transport;
 
 	/* SCTP AUTH: list of the endpoint shared keys.  These
 	 * keys are provided out of band by the user applicaton

net/sctp/associola.c

@@ -282,6 +282,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 		asoc->peer.asconf_capable = 1;
 	asoc->asconf_addr_del_pending = NULL;
 	asoc->src_out_of_asoc_ok = 0;
+	asoc->new_transport = NULL;
 
 	/* Create an input queue.  */
 	sctp_inq_init(&asoc->base.inqueue);

net/sctp/sm_make_chunk.c

@@ -3015,6 +3015,7 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
 		/* Start the heartbeat timer. */
 		if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
 			sctp_transport_hold(peer);
+		asoc->new_transport = peer;
 		break;
 	case SCTP_PARAM_DEL_IP:
 		/* ADDIP 4.3 D7) If a request is received to delete the

net/sctp/sm_statefuns.c

@@ -3612,6 +3612,11 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
 	 */
 	asconf_ack->dest = chunk->source;
 	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
+	if (asoc->new_transport) {
+	        sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport,
+                    commands);
+		((struct sctp_association *)asoc)->new_transport = NULL;
+	}
 
 	return SCTP_DISPOSITION_CONSUME;
 }