Merge branch 'linus' into core/rodatatip-core-rodata-2008-06-16_09.24_Mon

6 files changed, 143 insertions, 72 deletions

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index b4cd2b71953f..532634861db1 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1203,6 +1203,9 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 	struct list_head *head = &asoc->peer.transport_addr_list;
 	struct list_head *pos;
 
+	if (asoc->peer.transport_count == 1)
+		return;
+
 	/* Find the next transport in a round-robin fashion. */
 	t = asoc->peer.retran_path;
 	pos = &t->transports;
@@ -1217,6 +1220,15 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 
 		t = list_entry(pos, struct sctp_transport, transports);
 
+		/* We have exhausted the list, but didn't find any
+		 * other active transports.  If so, use the next
+		 * transport.
+		 */
+		if (t == asoc->peer.retran_path) {
+			t = next;
+			break;
+		}
+
 		/* Try to find an active transport. */
 
 		if ((t->state == SCTP_ACTIVE) ||
@@ -1229,15 +1241,6 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 			if (!next)
 				next = t;
 		}
-
-		/* We have exhausted the list, but didn't find any
-		 * other active transports.  If so, use the next
-		 * transport.
-		 */
-		if (t == asoc->peer.retran_path) {
-			t = next;
-			break;
-		}
 	}
 
 	asoc->peer.retran_path = t;
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index e45e44c60635..a2f4d4d51593 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -299,7 +299,8 @@ static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 /* Fills in the source address(saddr) based on the destination address(daddr)
  * and asoc's bind address list.
  */
-static void sctp_v6_get_saddr(struct sctp_association *asoc,
+static void sctp_v6_get_saddr(struct sctp_sock *sk,
+			      struct sctp_association *asoc,
 			      struct dst_entry *dst,
 			      union sctp_addr *daddr,
 			      union sctp_addr *saddr)
@@ -318,7 +319,7 @@ static void sctp_v6_get_saddr(struct sctp_association *asoc,
 	if (!asoc) {
 		ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
 				   &daddr->v6.sin6_addr,
-				   inet6_sk(asoc->base.sk)->srcprefs,
+				   inet6_sk(&sk->inet.sk)->srcprefs,
 				   &saddr->v6.sin6_addr);
 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
 				  NIP6(saddr->v6.sin6_addr));
@@ -726,6 +727,11 @@ static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 	seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
 }
 
+static void sctp_v6_ecn_capable(struct sock *sk)
+{
+	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
+}
+
 /* Initialize a PF_INET6 socket msg_name. */
 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 {
@@ -996,6 +1002,7 @@ static struct sctp_af sctp_af_inet6 = {
 	.skb_iif	   = sctp_v6_skb_iif,
 	.is_ce		   = sctp_v6_is_ce,
 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
+	.ecn_capable	   = sctp_v6_ecn_capable,
 	.net_header_len	   = sizeof(struct ipv6hdr),
 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
 #ifdef CONFIG_COMPAT
diff --git a/net/sctp/output.c b/net/sctp/output.c
index cf4f9fb6819d..6d45bae93b46 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -548,7 +548,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	 * Note: The works for IPv6 layer checks this bit too later
 	 * in transmission.  See IP6_ECN_flow_xmit().
 	 */
-	INET_ECN_xmit(nskb->sk);
+	(*tp->af_specific->ecn_capable)(nskb->sk);
 
 	/* Set up the IP options.  */
 	/* BUG: not implemented
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 59edfd25a19c..ace6770e9048 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -208,6 +208,7 @@ void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
 	INIT_LIST_HEAD(&q->sacked);
 	INIT_LIST_HEAD(&q->abandoned);
 
+	q->fast_rtx = 0;
 	q->outstanding_bytes = 0;
 	q->empty = 1;
 	q->cork  = 0;
@@ -500,6 +501,7 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
 	case SCTP_RTXR_FAST_RTX:
 		SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
 		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
+		q->fast_rtx = 1;
 		break;
 	case SCTP_RTXR_PMTUD:
 		SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
@@ -518,9 +520,15 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
 	 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
 	 * following the procedures outlined in C1 - C5.
 	 */
-	sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
+	if (reason == SCTP_RTXR_T3_RTX)
+		sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
 
-	error = sctp_outq_flush(q, /* rtx_timeout */ 1);
+	/* Flush the queues only on timeout, since fast_rtx is only
+	 * triggered during sack processing and the queue
+	 * will be flushed at the end.
+	 */
+	if (reason != SCTP_RTXR_FAST_RTX)
+		error = sctp_outq_flush(q, /* rtx_timeout */ 1);
 
 	if (error)
 		q->asoc->base.sk->sk_err = -error;
@@ -538,17 +546,23 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
 			       int rtx_timeout, int *start_timer)
 {
 	struct list_head *lqueue;
-	struct list_head *lchunk;
 	struct sctp_transport *transport = pkt->transport;
 	sctp_xmit_t status;
 	struct sctp_chunk *chunk, *chunk1;
 	struct sctp_association *asoc;
+	int fast_rtx;
 	int error = 0;
+	int timer = 0;
+	int done = 0;
 
 	asoc = q->asoc;
 	lqueue = &q->retransmit;
+	fast_rtx = q->fast_rtx;
 
-	/* RFC 2960 6.3.3 Handle T3-rtx Expiration
+	/* This loop handles time-out retransmissions, fast retransmissions,
+	 * and retransmissions due to opening of whindow.
+	 *
+	 * RFC 2960 6.3.3 Handle T3-rtx Expiration
 	 *
 	 * E3) Determine how many of the earliest (i.e., lowest TSN)
 	 * outstanding DATA chunks for the address for which the
@@ -563,12 +577,12 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
 	 * [Just to be painfully clear, if we are retransmitting
 	 * because a timeout just happened, we should send only ONE
 	 * packet of retransmitted data.]
+	 *
+	 * For fast retransmissions we also send only ONE packet.  However,
+	 * if we are just flushing the queue due to open window, we'll
+	 * try to send as much as possible.
 	 */
-	lchunk = sctp_list_dequeue(lqueue);
-
-	while (lchunk) {
-		chunk = list_entry(lchunk, struct sctp_chunk,
-				   transmitted_list);
+	list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
 
 		/* Make sure that Gap Acked TSNs are not retransmitted.  A
 		 * simple approach is just to move such TSNs out of the
@@ -576,58 +590,60 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
 		 * next chunk.
 		 */
 		if (chunk->tsn_gap_acked) {
-			list_add_tail(lchunk, &transport->transmitted);
-			lchunk = sctp_list_dequeue(lqueue);
+			list_del(&chunk->transmitted_list);
+			list_add_tail(&chunk->transmitted_list,
+					&transport->transmitted);
 			continue;
 		}
 
+		/* If we are doing fast retransmit, ignore non-fast_rtransmit
+		 * chunks
+		 */
+		if (fast_rtx && !chunk->fast_retransmit)
+			continue;
+
 		/* Attempt to append this chunk to the packet. */
 		status = sctp_packet_append_chunk(pkt, chunk);
 
 		switch (status) {
 		case SCTP_XMIT_PMTU_FULL:
 			/* Send this packet.  */
-			if ((error = sctp_packet_transmit(pkt)) == 0)
-				*start_timer = 1;
+			error = sctp_packet_transmit(pkt);
 
 			/* If we are retransmitting, we should only
 			 * send a single packet.
 			 */
-			if (rtx_timeout) {
-				list_add(lchunk, lqueue);
-				lchunk = NULL;
-			}
+			if (rtx_timeout || fast_rtx)
+				done = 1;
 
-			/* Bundle lchunk in the next round.  */
+			/* Bundle next chunk in the next round.  */
 			break;
 
 		case SCTP_XMIT_RWND_FULL:
 			/* Send this packet. */
-			if ((error = sctp_packet_transmit(pkt)) == 0)
-				*start_timer = 1;
+			error = sctp_packet_transmit(pkt);
 
 			/* Stop sending DATA as there is no more room
 			 * at the receiver.
 			 */
-			list_add(lchunk, lqueue);
-			lchunk = NULL;
+			done = 1;
 			break;
 
 		case SCTP_XMIT_NAGLE_DELAY:
 			/* Send this packet. */
-			if ((error = sctp_packet_transmit(pkt)) == 0)
-				*start_timer = 1;
+			error = sctp_packet_transmit(pkt);
 
 			/* Stop sending DATA because of nagle delay. */
-			list_add(lchunk, lqueue);
-			lchunk = NULL;
+			done = 1;
 			break;
 
 		default:
 			/* The append was successful, so add this chunk to
 			 * the transmitted list.
 			 */
-			list_add_tail(lchunk, &transport->transmitted);
+			list_del(&chunk->transmitted_list);
+			list_add_tail(&chunk->transmitted_list,
+					&transport->transmitted);
 
 			/* Mark the chunk as ineligible for fast retransmit
 			 * after it is retransmitted.
@@ -635,27 +651,44 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
 			if (chunk->fast_retransmit > 0)
 				chunk->fast_retransmit = -1;
 
-			*start_timer = 1;
-			q->empty = 0;
+			/* Force start T3-rtx timer when fast retransmitting
+			 * the earliest outstanding TSN
+			 */
+			if (!timer && fast_rtx &&
+			    ntohl(chunk->subh.data_hdr->tsn) ==
+					     asoc->ctsn_ack_point + 1)
+				timer = 2;
 
-			/* Retrieve a new chunk to bundle. */
-			lchunk = sctp_list_dequeue(lqueue);
+			q->empty = 0;
 			break;
 		}
 
-		/* If we are here due to a retransmit timeout or a fast
-		 * retransmit and if there are any chunks left in the retransmit
-		 * queue that could not fit in the PMTU sized packet, they need
-		 * to be marked as ineligible for a subsequent fast retransmit.
-		 */
-		if (rtx_timeout && !lchunk) {
-			list_for_each_entry(chunk1, lqueue, transmitted_list) {
-				if (chunk1->fast_retransmit > 0)
-					chunk1->fast_retransmit = -1;
-			}
+		/* Set the timer if there were no errors */
+		if (!error && !timer)
+			timer = 1;
+
+		if (done)
+			break;
+	}
+
+	/* If we are here due to a retransmit timeout or a fast
+	 * retransmit and if there are any chunks left in the retransmit
+	 * queue that could not fit in the PMTU sized packet, they need
+	 * to be marked as ineligible for a subsequent fast retransmit.
+	 */
+	if (rtx_timeout || fast_rtx) {
+		list_for_each_entry(chunk1, lqueue, transmitted_list) {
+			if (chunk1->fast_retransmit > 0)
+				chunk1->fast_retransmit = -1;
 		}
 	}
 
+	*start_timer = timer;
+
+	/* Clear fast retransmit hint */
+	if (fast_rtx)
+		q->fast_rtx = 0;
+
 	return error;
 }
 
@@ -862,7 +895,8 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 						    rtx_timeout, &start_timer);
 
 			if (start_timer)
-				sctp_transport_reset_timers(transport);
+				sctp_transport_reset_timers(transport,
+							    start_timer-1);
 
 			/* This can happen on COOKIE-ECHO resend.  Only
 			 * one chunk can get bundled with a COOKIE-ECHO.
@@ -977,7 +1011,7 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 			list_add_tail(&chunk->transmitted_list,
 				      &transport->transmitted);
 
-			sctp_transport_reset_timers(transport);
+			sctp_transport_reset_timers(transport, start_timer-1);
 
 			q->empty = 0;
 
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 0ec234b762c2..b435a193c5df 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -470,11 +470,11 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 		/* Walk through the bind address list and look for a bind
 		 * address that matches the source address of the returned dst.
 		 */
+		sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
 		rcu_read_lock();
 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 			if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 				continue;
-			sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
 				goto out_unlock;
 		}
@@ -519,7 +519,8 @@ out:
 /* For v4, the source address is cached in the route entry(dst). So no need
  * to cache it separately and hence this is an empty routine.
  */
-static void sctp_v4_get_saddr(struct sctp_association *asoc,
+static void sctp_v4_get_saddr(struct sctp_sock *sk,
+			      struct sctp_association *asoc,
 			      struct dst_entry *dst,
 			      union sctp_addr *daddr,
 			      union sctp_addr *saddr)
@@ -616,6 +617,11 @@ static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 	seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
 }
 
+static void sctp_v4_ecn_capable(struct sock *sk)
+{
+	INET_ECN_xmit(sk);
+}
+
 /* Event handler for inet address addition/deletion events.
  * The sctp_local_addr_list needs to be protocted by a spin lock since
  * multiple notifiers (say IPv4 and IPv6) may be running at the same
@@ -934,6 +940,7 @@ static struct sctp_af sctp_af_inet = {
 	.skb_iif	   = sctp_v4_skb_iif,
 	.is_ce		   = sctp_v4_is_ce,
 	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
+	.ecn_capable	   = sctp_v4_ecn_capable,
 	.net_header_len	   = sizeof(struct iphdr),
 	.sockaddr_len	   = sizeof(struct sockaddr_in),
 #ifdef CONFIG_COMPAT
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index f4938f6c5abe..3f34f61221ec 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -79,6 +79,7 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 	peer->rttvar = 0;
 	peer->srtt = 0;
 	peer->rto_pending = 0;
+	peer->fast_recovery = 0;
 
 	peer->last_time_heard = jiffies;
 	peer->last_time_used = jiffies;
@@ -190,7 +191,7 @@ static void sctp_transport_destroy(struct sctp_transport *transport)
 /* Start T3_rtx timer if it is not already running and update the heartbeat
  * timer.  This routine is called every time a DATA chunk is sent.
  */
-void sctp_transport_reset_timers(struct sctp_transport *transport)
+void sctp_transport_reset_timers(struct sctp_transport *transport, int force)
 {
 	/* RFC 2960 6.3.2 Retransmission Timer Rules
 	 *
@@ -200,7 +201,7 @@ void sctp_transport_reset_timers(struct sctp_transport *transport)
 	 * address.
 	 */
 
-	if (!timer_pending(&transport->T3_rtx_timer))
+	if (force || !timer_pending(&transport->T3_rtx_timer))
 		if (!mod_timer(&transport->T3_rtx_timer,
 			       jiffies + transport->rto))
 			sctp_transport_hold(transport);
@@ -291,7 +292,7 @@ void sctp_transport_route(struct sctp_transport *transport,
 	if (saddr)
 		memcpy(&transport->saddr, saddr, sizeof(union sctp_addr));
 	else
-		af->get_saddr(asoc, dst, daddr, &transport->saddr);
+		af->get_saddr(opt, asoc, dst, daddr, &transport->saddr);
 
 	transport->dst = dst;
 	if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) {
@@ -403,11 +404,16 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
 	cwnd = transport->cwnd;
 	flight_size = transport->flight_size;
 
+	/* See if we need to exit Fast Recovery first */
+	if (transport->fast_recovery &&
+	    TSN_lte(transport->fast_recovery_exit, sack_ctsn))
+		transport->fast_recovery = 0;
+
 	/* The appropriate cwnd increase algorithm is performed if, and only
-	 * if the cumulative TSN has advanced and the congestion window is
+	 * if the cumulative TSN whould advanced and the congestion window is
 	 * being fully utilized.
 	 */
-	if ((transport->asoc->ctsn_ack_point >= sack_ctsn) ||
+	if (TSN_lte(sack_ctsn, transport->asoc->ctsn_ack_point) ||
 	    (flight_size < cwnd))
 		return;
 
@@ -416,17 +422,23 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
 	pmtu = transport->asoc->pathmtu;
 
 	if (cwnd <= ssthresh) {
-		/* RFC 2960 7.2.1, sctpimpguide-05 2.14.2 When cwnd is less
-		 * than or equal to ssthresh an SCTP endpoint MUST use the
-		 * slow start algorithm to increase cwnd only if the current
-		 * congestion window is being fully utilized and an incoming
-		 * SACK advances the Cumulative TSN Ack Point. Only when these
-		 * two conditions are met can the cwnd be increased otherwise
-		 * the cwnd MUST not be increased. If these conditions are met
-		 * then cwnd MUST be increased by at most the lesser of
-		 * 1) the total size of the previously outstanding DATA
-		 * chunk(s) acknowledged, and 2) the destination's path MTU.
+		/* RFC 4960 7.2.1
+		 * o  When cwnd is less than or equal to ssthresh, an SCTP
+		 *    endpoint MUST use the slow-start algorithm to increase
+		 *    cwnd only if the current congestion window is being fully
+		 *    utilized, an incoming SACK advances the Cumulative TSN
+		 *    Ack Point, and the data sender is not in Fast Recovery.
+		 *    Only when these three conditions are met can the cwnd be
+		 *    increased; otherwise, the cwnd MUST not be increased.
+		 *    If these conditions are met, then cwnd MUST be increased
+		 *    by, at most, the lesser of 1) the total size of the
+		 *    previously outstanding DATA chunk(s) acknowledged, and
+		 *    2) the destination's path MTU.  This upper bound protects
+		 *    against the ACK-Splitting attack outlined in [SAVAGE99].
 		 */
+		if (transport->fast_recovery)
+			return;
+
 		if (bytes_acked > pmtu)
 			cwnd += pmtu;
 		else
@@ -502,6 +514,13 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		 *      cwnd = ssthresh
 		 *      partial_bytes_acked = 0
 		 */
+		if (transport->fast_recovery)
+			return;
+
+		/* Mark Fast recovery */
+		transport->fast_recovery = 1;
+		transport->fast_recovery_exit = transport->asoc->next_tsn - 1;
+
 		transport->ssthresh = max(transport->cwnd/2,
 					  4*transport->asoc->pathmtu);
 		transport->cwnd = transport->ssthresh;
@@ -586,6 +605,7 @@ void sctp_transport_reset(struct sctp_transport *t)
 	t->flight_size = 0;
 	t->error_count = 0;
 	t->rto_pending = 0;
+	t->fast_recovery = 0;
 
 	/* Initialize the state information for SFR-CACC */
 	t->cacc.changeover_active = 0;