[SCTP]: Update SCTP_PEER_ADDR_PARAMS socket option to the latest api draft.

This patch adds support to set/get heartbeat interval, maximum number of
retransmissions, pathmtu, sackdelay time for a particular transport/
association/socket as per the latest SCTP sockets api draft11.

Signed-off-by: Frank Filz <ffilz@us.ibm.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/sm_sideeffect.c

@@ -157,9 +157,12 @@ static int sctp_gen_sack(struct sctp_association *asoc, int force,
 {
 	__u32 ctsn, max_tsn_seen;
 	struct sctp_chunk *sack;
+	struct sctp_transport *trans = asoc->peer.last_data_from;
 	int error = 0;
 
-	if (force)
+	if (force || 
+	    (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
+	    (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 		asoc->peer.sack_needed = 1;
 
 	ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
@@ -189,7 +192,22 @@ static int sctp_gen_sack(struct sctp_association *asoc, int force,
 	if (!asoc->peer.sack_needed) {
 		/* We will need a SACK for the next packet.  */
 		asoc->peer.sack_needed = 1;
-		goto out;
+
+		/* Set the SACK delay timeout based on the
+		 * SACK delay for the last transport
+		 * data was received from, or the default
+		 * for the association.
+		 */
+		if (trans)
+			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 
+				trans->sackdelay;
+		else
+			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 
+				asoc->sackdelay;
+
+		/* Restart the SACK timer. */
+		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 	} else {
 		if (asoc->a_rwnd > asoc->rwnd)
 			asoc->a_rwnd = asoc->rwnd;
@@ -205,7 +223,7 @@ static int sctp_gen_sack(struct sctp_association *asoc, int force,
 		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 	}
-out:
+
 	return error;
 nomem:
 	error = -ENOMEM;
@@ -415,7 +433,7 @@ static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 	asoc->overall_error_count++;
 
 	if (transport->state != SCTP_INACTIVE &&
-	    (transport->error_count++ >= transport->max_retrans)) {
+	    (transport->error_count++ >= transport->pathmaxrxt)) {
 		SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 					 " transport IP: port:%d failed.\n",
 					 asoc,