[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>

include/net/sctp/structs.h

@@ -277,6 +277,24 @@ struct sctp_sock {
 	__u32 default_context;
 	__u32 default_timetolive;
 
+	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
+	 * the destination address every heartbeat interval. This value
+	 * will be inherited by all new associations.
+	 */
+	__u32 hbinterval;
+
+	/* This is the max_retrans value for new associations. */
+	__u16 pathmaxrxt;
+
+	/* The initial Path MTU to use for new associations. */
+	__u32 pathmtu;
+
+	/* The default SACK delay timeout for new associations. */
+	__u32 sackdelay;
+
+	/* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
+	__u32 param_flags;
+
 	struct sctp_initmsg initmsg;
 	struct sctp_rtoinfo rtoinfo;
 	struct sctp_paddrparams paddrparam;
@@ -845,9 +863,6 @@ struct sctp_transport {
 	/* Data that has been sent, but not acknowledged. */
 	__u32 flight_size;
 
-	/* PMTU	      : The current known path MTU.  */
-	__u32 pmtu;
-
 	/* Destination */
 	struct dst_entry *dst;
 	/* Source address. */
@@ -862,7 +877,22 @@ struct sctp_transport {
 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 	 * the destination address every heartbeat interval.
 	 */
-	int hb_interval;
+	__u32 hbinterval;
+
+	/* This is the max_retrans value for the transport and will
+	 * be initialized from the assocs value.  This can be changed
+	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
+	 */
+	__u16 pathmaxrxt;
+
+	/* PMTU	      : The current known path MTU.  */
+	__u32 pathmtu;
+
+	/* SACK delay timeout */
+	__u32 sackdelay;
+
+	/* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
+	__u32 param_flags;
 
 	/* When was the last time (in jiffies) that we heard from this
 	 * transport?  We use this to pick new active and retran paths.
@@ -882,22 +912,11 @@ struct sctp_transport {
 	 */
 	int state;
 
-	/* hb_allowed  : The current heartbeat state of this destination,
-	 *	       :  i.e. ALLOW-HB, NO-HEARTBEAT, etc.
-	 */
-	int hb_allowed;
-
 	/* These are the error stats for this destination.  */
 
 	/* Error count : The current error count for this destination.	*/
 	unsigned short error_count;
 
-	/* This is the max_retrans value for the transport and will
-	 * be initialized to proto.max_retrans.path.  This can be changed
-	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
-	 */
-	int max_retrans;
-
 	/* Per	       : A timer used by each destination.
 	 * Destination :
 	 * Timer       :
@@ -1502,6 +1521,28 @@ struct sctp_association {
 	/* The largest timeout or RTO value to use in attempting an INIT */
 	__u16 max_init_timeo;
 
+	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
+	 * the destination address every heartbeat interval. This value
+	 * will be inherited by all new transports.
+	 */
+	__u32 hbinterval;
+
+	/* This is the max_retrans value for new transports in the
+	 * association.
+	 */
+	__u16 pathmaxrxt;
+
+	/* Association : The smallest PMTU discovered for all of the
+	 * PMTU	       : peer's transport addresses.
+	 */
+	__u32 pathmtu;
+
+	/* SACK delay timeout */
+	__u32 sackdelay;
+
+	/* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
+	__u32 param_flags;
+
 	int timeouts[SCTP_NUM_TIMEOUT_TYPES];
 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
 
@@ -1571,11 +1612,6 @@ struct sctp_association {
 	 */
 	wait_queue_head_t	wait;
 
-	/* Association : The smallest PMTU discovered for all of the
-	 * PMTU	       : peer's transport addresses.
-	 */
-	__u32 pmtu;
-
 	/* The message size at which SCTP fragmentation will occur. */
 	__u32 frag_point;
 

include/net/sctp/user.h

@@ -503,11 +503,27 @@ struct sctp_setadaption {
  *   unreachable. The following structure is used to access and modify an
  *   address's parameters:
  */
+enum  sctp_spp_flags {
+	SPP_HB_ENABLE = 1,		/*Enable heartbeats*/
+	SPP_HB_DISABLE = 2,		/*Disable heartbeats*/
+	SPP_HB = SPP_HB_ENABLE | SPP_HB_DISABLE,
+	SPP_HB_DEMAND = 4,		/*Send heartbeat immediately*/
+	SPP_PMTUD_ENABLE = 8,		/*Enable PMTU discovery*/
+	SPP_PMTUD_DISABLE = 16,		/*Disable PMTU discovery*/
+	SPP_PMTUD = SPP_PMTUD_ENABLE | SPP_PMTUD_DISABLE,
+	SPP_SACKDELAY_ENABLE = 32,	/*Enable SACK*/
+	SPP_SACKDELAY_DISABLE = 64,	/*Disable SACK*/
+	SPP_SACKDELAY = SPP_SACKDELAY_ENABLE | SPP_SACKDELAY_DISABLE,
+};
+
 struct sctp_paddrparams {
 	sctp_assoc_t		spp_assoc_id;
 	struct sockaddr_storage	spp_address;
 	__u32			spp_hbinterval;
 	__u16			spp_pathmaxrxt;
+	__u32			spp_pathmtu;
+	__u32			spp_sackdelay;
+	__u32			spp_flags;
 } __attribute__((packed, aligned(4)));
 
 /*

net/sctp/associola.c

@@ -110,7 +110,6 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 	asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
 	asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
 					* 1000;
-	asoc->pmtu = 0;
 	asoc->frag_point = 0;
 
 	/* Set the association max_retrans and RTO values from the
@@ -123,6 +122,25 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 
 	asoc->overall_error_count = 0;
 
+	/* Initialize the association's heartbeat interval based on the
+	 * sock configured value.
+	 */
+	asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
+
+	/* Initialize path max retrans value. */
+	asoc->pathmaxrxt = sp->pathmaxrxt;
+
+	/* Initialize default path MTU. */
+	asoc->pathmtu = sp->pathmtu;
+
+	/* Set association default SACK delay */
+	asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
+
+	/* Set the association default flags controlling
+	 * Heartbeat, SACK delay, and Path MTU Discovery.
+	 */
+	asoc->param_flags = sp->param_flags;
+
 	/* Initialize the maximum mumber of new data packets that can be sent
 	 * in a burst.
 	 */
@@ -144,8 +162,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 		= 5 * asoc->rto_max;
 
 	asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
-	asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
-		SCTP_DEFAULT_TIMEOUT_SACK;
+	asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
 	asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
 		sp->autoclose * HZ;
 	
@@ -540,23 +557,46 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 
 	sctp_transport_set_owner(peer, asoc);
 
+	/* Initialize the peer's heartbeat interval based on the
+	 * association configured value.
+	 */
+	peer->hbinterval = asoc->hbinterval;
+
+	/* Set the path max_retrans.  */
+	peer->pathmaxrxt = asoc->pathmaxrxt;
+
+	/* Initialize the peer's SACK delay timeout based on the
+	 * association configured value.
+	 */
+	peer->sackdelay = asoc->sackdelay;
+
+	/* Enable/disable heartbeat, SACK delay, and path MTU discovery
+	 * based on association setting.
+	 */
+	peer->param_flags = asoc->param_flags;
+
 	/* Initialize the pmtu of the transport. */
-	sctp_transport_pmtu(peer);
+	if (peer->param_flags & SPP_PMTUD_ENABLE)
+		sctp_transport_pmtu(peer);
+	else if (asoc->pathmtu)
+		peer->pathmtu = asoc->pathmtu;
+	else
+		peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 
 	/* If this is the first transport addr on this association,
 	 * initialize the association PMTU to the peer's PMTU.
 	 * If not and the current association PMTU is higher than the new
 	 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
 	 */
-	if (asoc->pmtu)
-		asoc->pmtu = min_t(int, peer->pmtu, asoc->pmtu);
+	if (asoc->pathmtu)
+		asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
 	else
-		asoc->pmtu = peer->pmtu;
+		asoc->pathmtu = peer->pathmtu;
 
 	SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
-			  "%d\n", asoc, asoc->pmtu);
+			  "%d\n", asoc, asoc->pathmtu);
 
-	asoc->frag_point = sctp_frag_point(sp, asoc->pmtu);
+	asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
 
 	/* The asoc->peer.port might not be meaningful yet, but
 	 * initialize the packet structure anyway.
@@ -574,7 +614,7 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 	 *   (for example, implementations MAY use the size of the
 	 *   receiver advertised window).
 	 */
-	peer->cwnd = min(4*asoc->pmtu, max_t(__u32, 2*asoc->pmtu, 4380));
+	peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
 
 	/* At this point, we may not have the receiver's advertised window,
 	 * so initialize ssthresh to the default value and it will be set
@@ -585,17 +625,6 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 	peer->partial_bytes_acked = 0;
 	peer->flight_size = 0;
 
-	/* By default, enable heartbeat for peer address. */
-	peer->hb_allowed = 1;
-
-	/* Initialize the peer's heartbeat interval based on the
-	 * sock configured value.
-	 */
-	peer->hb_interval = msecs_to_jiffies(sp->paddrparam.spp_hbinterval);
-
-	/* Set the path max_retrans.  */
-	peer->max_retrans = sp->paddrparam.spp_pathmaxrxt;
-
 	/* Set the transport's RTO.initial value */
 	peer->rto = asoc->rto_initial;
 
@@ -1155,18 +1184,18 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
 	/* Get the lowest pmtu of all the transports. */
 	list_for_each(pos, &asoc->peer.transport_addr_list) {
 		t = list_entry(pos, struct sctp_transport, transports);
-		if (!pmtu || (t->pmtu < pmtu))
-			pmtu = t->pmtu;
+		if (!pmtu || (t->pathmtu < pmtu))
+			pmtu = t->pathmtu;
 	}
 
 	if (pmtu) {
 		struct sctp_sock *sp = sctp_sk(asoc->base.sk);
-		asoc->pmtu = pmtu;
+		asoc->pathmtu = pmtu;
 		asoc->frag_point = sctp_frag_point(sp, pmtu);
 	}
 
 	SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
-			  __FUNCTION__, asoc, asoc->pmtu, asoc->frag_point);
+			  __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
 }
 
 /* Should we send a SACK to update our peer? */
@@ -1179,7 +1208,7 @@ static inline int sctp_peer_needs_update(struct sctp_association *asoc)
 	case SCTP_STATE_SHUTDOWN_SENT:
 		if ((asoc->rwnd > asoc->a_rwnd) &&
 		    ((asoc->rwnd - asoc->a_rwnd) >=
-		     min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pmtu)))
+		     min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
 			return 1;
 		break;
 	default:

net/sctp/input.c

@@ -305,18 +305,36 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
 			   struct sctp_transport *t, __u32 pmtu)
 {
-	if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
-		printk(KERN_WARNING "%s: Reported pmtu %d too low, "
-		       "using default minimum of %d\n", __FUNCTION__, pmtu,
-		       SCTP_DEFAULT_MINSEGMENT);
-		pmtu = SCTP_DEFAULT_MINSEGMENT;
+	if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu))
+		return;
+
+	if (t->param_flags & SPP_PMTUD_ENABLE) {
+		if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
+			printk(KERN_WARNING "%s: Reported pmtu %d too low, "
+			       "using default minimum of %d\n",
+			       __FUNCTION__, pmtu,
+			       SCTP_DEFAULT_MINSEGMENT);
+			/* Use default minimum segment size and disable
+			 * pmtu discovery on this transport.
+			 */
+			t->pathmtu = SCTP_DEFAULT_MINSEGMENT;
+			t->param_flags = (t->param_flags & ~SPP_HB) |
+				SPP_PMTUD_DISABLE;
+		} else {
+			t->pathmtu = pmtu;
+		}
+
+		/* Update association pmtu. */
+		sctp_assoc_sync_pmtu(asoc);
 	}
 
-	if (!sock_owned_by_user(sk) && t && (t->pmtu != pmtu)) {
-		t->pmtu = pmtu;
-		sctp_assoc_sync_pmtu(asoc);
-		sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
-	}
+	/* Retransmit with the new pmtu setting.
+	 * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
+	 * Needed will never be sent, but if a message was sent before
+	 * PMTU discovery was disabled that was larger than the PMTU, it
+	 * would not be fragmented, so it must be re-transmitted fragmented.	 
+	 */
+	sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
 }
 
 /*

net/sctp/output.c

@@ -234,8 +234,8 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 		goto finish;
 
 	pmtu  = ((packet->transport->asoc) ?
-		 (packet->transport->asoc->pmtu) :
-		 (packet->transport->pmtu));
+		 (packet->transport->asoc->pathmtu) :
+		 (packet->transport->pathmtu));
 
 	too_big = (psize + chunk_len > pmtu);
 
@@ -482,7 +482,9 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	if (!dst || (dst->obsolete > 1)) {
 		dst_release(dst);
 		sctp_transport_route(tp, NULL, sctp_sk(sk));
-		sctp_assoc_sync_pmtu(asoc);
+		if (asoc->param_flags & SPP_PMTUD_ENABLE) {
+			sctp_assoc_sync_pmtu(asoc);
+		}
 	}
 
 	nskb->dst = dst_clone(tp->dst);
@@ -492,7 +494,10 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb len %d\n",
 			  nskb->len);
 
-	(*tp->af_specific->sctp_xmit)(nskb, tp, packet->ipfragok);
+	if (tp->param_flags & SPP_PMTUD_ENABLE)
+		(*tp->af_specific->sctp_xmit)(nskb, tp, packet->ipfragok);
+	else
+		(*tp->af_specific->sctp_xmit)(nskb, tp, 1);
 
 out:
 	packet->size = packet->overhead;
@@ -577,7 +582,7 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	 * 	if ((flightsize + Max.Burst * MTU) < cwnd)
 	 *		cwnd = flightsize + Max.Burst * MTU
 	 */
-	max_burst_bytes = asoc->max_burst * asoc->pmtu;
+	max_burst_bytes = asoc->max_burst * asoc->pathmtu;
 	if ((transport->flight_size + max_burst_bytes) < transport->cwnd) {
 		transport->cwnd = transport->flight_size + max_burst_bytes;
 		SCTP_DEBUG_PRINTK("%s: cwnd limited by max_burst: "
@@ -622,7 +627,7 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 		 * data will fit or delay in hopes of bundling a full
 		 * sized packet.
 		 */
-		if (len < asoc->pmtu - packet->overhead) {
+		if (len < asoc->pathmtu - packet->overhead) {
 			retval = SCTP_XMIT_NAGLE_DELAY;
 			goto finish;
 		}

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,

net/sctp/sm_statefuns.c

@@ -900,7 +900,7 @@ sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
 	 * HEARTBEAT is sent (see Section 8.3).
 	 */
 
-	if (transport->hb_allowed) {
+	if (transport->param_flags & SPP_HB_ENABLE) {
 		if (SCTP_DISPOSITION_NOMEM ==
 				sctp_sf_heartbeat(ep, asoc, type, arg,
 						  commands))
@@ -1051,7 +1051,7 @@ sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
 		return SCTP_DISPOSITION_DISCARD;
 	}
 
-	max_interval = link->hb_interval + link->rto;
+	max_interval = link->hbinterval + link->rto;
 
 	/* Check if the timestamp looks valid.  */
 	if (time_after(hbinfo->sent_at, jiffies) ||
@@ -2691,14 +2691,9 @@ sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
 	 * document allow. However, an SCTP transmitter MUST NOT be
 	 * more aggressive than the following algorithms allow.
 	 */
-	if (chunk->end_of_packet) {
+	if (chunk->end_of_packet)
 		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
 
-		/* Start the SACK timer.  */
-		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
-				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
-	}
-
 	return SCTP_DISPOSITION_CONSUME;
 
 discard_force:
@@ -2721,13 +2716,9 @@ discard_force:
 	return SCTP_DISPOSITION_DISCARD;
 
 discard_noforce:
-	if (chunk->end_of_packet) {
+	if (chunk->end_of_packet)
 		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
 
-		/* Start the SACK timer.  */
-		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
-				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
-	}
 	return SCTP_DISPOSITION_DISCARD;
 consume:
 	return SCTP_DISPOSITION_CONSUME;
@@ -3442,9 +3433,6 @@ sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
 	 * send another. 
 	 */
 	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
-	/* Start the SACK timer.  */
-	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
-			SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 
 	return SCTP_DISPOSITION_CONSUME;
 

net/sctp/transport.c

@@ -86,10 +86,13 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 	peer->init_sent_count = 0;
 
 	peer->state = SCTP_ACTIVE;
-	peer->hb_allowed = 0;
+	peer->param_flags = SPP_HB_DISABLE |
+			    SPP_PMTUD_ENABLE |
+			    SPP_SACKDELAY_ENABLE;
+	peer->hbinterval  = 0;
 
 	/* Initialize the default path max_retrans.  */
-	peer->max_retrans = sctp_max_retrans_path;
+	peer->pathmaxrxt  = sctp_max_retrans_path;
 	peer->error_count = 0;
 
 	INIT_LIST_HEAD(&peer->transmitted);
@@ -229,10 +232,10 @@ void sctp_transport_pmtu(struct sctp_transport *transport)
 	dst = transport->af_specific->get_dst(NULL, &transport->ipaddr, NULL);
 
 	if (dst) {
-		transport->pmtu = dst_mtu(dst);
+		transport->pathmtu = dst_mtu(dst);
 		dst_release(dst);
 	} else
-		transport->pmtu = SCTP_DEFAULT_MAXSEGMENT;
+		transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }
 
 /* Caches the dst entry and source address for a transport's destination
@@ -254,8 +257,11 @@ void sctp_transport_route(struct sctp_transport *transport,
 		af->get_saddr(asoc, dst, daddr, &transport->saddr);
 
 	transport->dst = dst;
+	if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) {
+		return;
+	}
 	if (dst) {
-		transport->pmtu = dst_mtu(dst);
+		transport->pathmtu = dst_mtu(dst);
 
 		/* Initialize sk->sk_rcv_saddr, if the transport is the
 		 * association's active path for getsockname().
@@ -264,7 +270,7 @@ void sctp_transport_route(struct sctp_transport *transport,
 			opt->pf->af->to_sk_saddr(&transport->saddr,
 						 asoc->base.sk);
 	} else
-		transport->pmtu = SCTP_DEFAULT_MAXSEGMENT;
+		transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }
 
 /* Hold a reference to a transport.  */
@@ -369,7 +375,7 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
 
 	ssthresh = transport->ssthresh;
 	pba = transport->partial_bytes_acked;
-	pmtu = transport->asoc->pmtu;
+	pmtu = transport->asoc->pathmtu;
 
 	if (cwnd <= ssthresh) {
 		/* RFC 2960 7.2.1, sctpimpguide-05 2.14.2 When cwnd is less
@@ -441,8 +447,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		 *      partial_bytes_acked = 0
 		 */
 		transport->ssthresh = max(transport->cwnd/2,
-					  4*transport->asoc->pmtu);
-		transport->cwnd = transport->asoc->pmtu;
+					  4*transport->asoc->pathmtu);
+		transport->cwnd = transport->asoc->pathmtu;
 		break;
 
 	case SCTP_LOWER_CWND_FAST_RTX:
@@ -459,7 +465,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		 *      partial_bytes_acked = 0
 		 */
 		transport->ssthresh = max(transport->cwnd/2,
-					  4*transport->asoc->pmtu);
+					  4*transport->asoc->pathmtu);
 		transport->cwnd = transport->ssthresh;
 		break;
 
@@ -479,7 +485,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		if ((jiffies - transport->last_time_ecne_reduced) >
 		    transport->rtt) {
 			transport->ssthresh = max(transport->cwnd/2,
-					  	  4*transport->asoc->pmtu);
+					  	  4*transport->asoc->pathmtu);
 			transport->cwnd = transport->ssthresh;
 			transport->last_time_ecne_reduced = jiffies;
 		}
@@ -496,7 +502,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		 */
 		if ((jiffies - transport->last_time_used) > transport->rto)
 			transport->cwnd = max(transport->cwnd/2,
-						 4*transport->asoc->pmtu);
+						 4*transport->asoc->pathmtu);
 		break;
 	};
 
@@ -511,7 +517,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 unsigned long sctp_transport_timeout(struct sctp_transport *t)
 {
 	unsigned long timeout;
-	timeout = t->hb_interval + t->rto + sctp_jitter(t->rto);
+	timeout = t->hbinterval + t->rto + sctp_jitter(t->rto);
 	timeout += jiffies;
 	return timeout;
 }