Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

5 files changed, 29 insertions, 36 deletions

diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 3569d8ecaea..6afc807ee2a 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -216,7 +216,6 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TCPPartialUndo", LINUX_MIB_TCPPARTIALUNDO),
 	SNMP_MIB_ITEM("TCPDSACKUndo", LINUX_MIB_TCPDSACKUNDO),
 	SNMP_MIB_ITEM("TCPLossUndo", LINUX_MIB_TCPLOSSUNDO),
-	SNMP_MIB_ITEM("TCPLoss", LINUX_MIB_TCPLOSS),
 	SNMP_MIB_ITEM("TCPLostRetransmit", LINUX_MIB_TCPLOSTRETRANSMIT),
 	SNMP_MIB_ITEM("TCPRenoFailures", LINUX_MIB_TCPRENOFAILURES),
 	SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES),
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index 6187eb4d1dc..f45e1c24244 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -63,7 +63,6 @@ static inline void bictcp_reset(struct bictcp *ca)
 {
 	ca->cnt = 0;
 	ca->last_max_cwnd = 0;
-	ca->loss_cwnd = 0;
 	ca->last_cwnd = 0;
 	ca->last_time = 0;
 	ca->epoch_start = 0;
@@ -72,7 +71,11 @@ static inline void bictcp_reset(struct bictcp *ca)
 
 static void bictcp_init(struct sock *sk)
 {
-	bictcp_reset(inet_csk_ca(sk));
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	bictcp_reset(ca);
+	ca->loss_cwnd = 0;
+
 	if (initial_ssthresh)
 		tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
 }
@@ -127,7 +130,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 	}
 
 	/* if in slow start or link utilization is very low */
-	if (ca->loss_cwnd == 0) {
+	if (ca->last_max_cwnd == 0) {
 		if (ca->cnt > 20) /* increase cwnd 5% per RTT */
 			ca->cnt = 20;
 	}
@@ -185,7 +188,7 @@ static u32 bictcp_undo_cwnd(struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct bictcp *ca = inet_csk_ca(sk);
-	return max(tp->snd_cwnd, ca->last_max_cwnd);
+	return max(tp->snd_cwnd, ca->loss_cwnd);
 }
 
 static void bictcp_state(struct sock *sk, u8 new_state)
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index f376b05cca8..a9077f441cb 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -107,7 +107,6 @@ static inline void bictcp_reset(struct bictcp *ca)
 {
 	ca->cnt = 0;
 	ca->last_max_cwnd = 0;
-	ca->loss_cwnd = 0;
 	ca->last_cwnd = 0;
 	ca->last_time = 0;
 	ca->bic_origin_point = 0;
@@ -142,7 +141,10 @@ static inline void bictcp_hystart_reset(struct sock *sk)
 
 static void bictcp_init(struct sock *sk)
 {
-	bictcp_reset(inet_csk_ca(sk));
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	bictcp_reset(ca);
+	ca->loss_cwnd = 0;
 
 	if (hystart)
 		bictcp_hystart_reset(sk);
@@ -275,7 +277,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 	 * The initial growth of cubic function may be too conservative
 	 * when the available bandwidth is still unknown.
 	 */
-	if (ca->loss_cwnd == 0 && ca->cnt > 20)
+	if (ca->last_max_cwnd == 0 && ca->cnt > 20)
 		ca->cnt = 20;	/* increase cwnd 5% per RTT */
 
 	/* TCP Friendly */
@@ -342,7 +344,7 @@ static u32 bictcp_undo_cwnd(struct sock *sk)
 {
 	struct bictcp *ca = inet_csk_ca(sk);
 
-	return max(tcp_sk(sk)->snd_cwnd, ca->last_max_cwnd);
+	return max(tcp_sk(sk)->snd_cwnd, ca->loss_cwnd);
 }
 
 static void bictcp_state(struct sock *sk, u8 new_state)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2877c3e0958..976034f8232 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -105,7 +105,6 @@ int sysctl_tcp_abc __read_mostly;
 #define FLAG_SYN_ACKED		0x10 /* This ACK acknowledged SYN.		*/
 #define FLAG_DATA_SACKED	0x20 /* New SACK.				*/
 #define FLAG_ECE		0x40 /* ECE in this ACK				*/
-#define FLAG_DATA_LOST		0x80 /* SACK detected data lossage.		*/
 #define FLAG_SLOWPATH		0x100 /* Do not skip RFC checks for window update.*/
 #define FLAG_ONLY_ORIG_SACKED	0x200 /* SACKs only non-rexmit sent before RTO */
 #define FLAG_SND_UNA_ADVANCED	0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
@@ -1040,13 +1039,11 @@ static void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp,
  * These 6 states form finite state machine, controlled by the following events:
  * 1. New ACK (+SACK) arrives. (tcp_sacktag_write_queue())
  * 2. Retransmission. (tcp_retransmit_skb(), tcp_xmit_retransmit_queue())
- * 3. Loss detection event of one of three flavors:
+ * 3. Loss detection event of two flavors:
  *	A. Scoreboard estimator decided the packet is lost.
  *	   A'. Reno "three dupacks" marks head of queue lost.
- *	   A''. Its FACK modfication, head until snd.fack is lost.
- *	B. SACK arrives sacking data transmitted after never retransmitted
- *	   hole was sent out.
- *	C. SACK arrives sacking SND.NXT at the moment, when the
+ *	   A''. Its FACK modification, head until snd.fack is lost.
+ *	B. SACK arrives sacking SND.NXT at the moment, when the
  *	   segment was retransmitted.
  * 4. D-SACK added new rule: D-SACK changes any tag to S.
  *
@@ -1153,7 +1150,7 @@ static int tcp_is_sackblock_valid(struct tcp_sock *tp, int is_dsack,
 }
 
 /* Check for lost retransmit. This superb idea is borrowed from "ratehalving".
- * Event "C". Later note: FACK people cheated me again 8), we have to account
+ * Event "B". Later note: FACK people cheated me again 8), we have to account
  * for reordering! Ugly, but should help.
  *
  * Search retransmitted skbs from write_queue that were sent when snd_nxt was
@@ -1844,10 +1841,6 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 		if (found_dup_sack && ((i + 1) == first_sack_index))
 			next_dup = &sp[i + 1];
 
-		/* Event "B" in the comment above. */
-		if (after(end_seq, tp->high_seq))
-			state.flag |= FLAG_DATA_LOST;
-
 		/* Skip too early cached blocks */
 		while (tcp_sack_cache_ok(tp, cache) &&
 		       !before(start_seq, cache->end_seq))
@@ -2515,8 +2508,11 @@ static void tcp_timeout_skbs(struct sock *sk)
 	tcp_verify_left_out(tp);
 }
 
-/* Mark head of queue up as lost. With RFC3517 SACK, the packets is
- * is against sacked "cnt", otherwise it's against facked "cnt"
+/* Detect loss in event "A" above by marking head of queue up as lost.
+ * For FACK or non-SACK(Reno) senders, the first "packets" number of segments
+ * are considered lost. For RFC3517 SACK, a segment is considered lost if it
+ * has at least tp->reordering SACKed seqments above it; "packets" refers to
+ * the maximum SACKed segments to pass before reaching this limit.
  */
 static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
 {
@@ -2525,6 +2521,8 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
 	int cnt, oldcnt;
 	int err;
 	unsigned int mss;
+	/* Use SACK to deduce losses of new sequences sent during recovery */
+	const u32 loss_high = tcp_is_sack(tp) ?  tp->snd_nxt : tp->high_seq;
 
 	WARN_ON(packets > tp->packets_out);
 	if (tp->lost_skb_hint) {
@@ -2546,7 +2544,7 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
 		tp->lost_skb_hint = skb;
 		tp->lost_cnt_hint = cnt;
 
-		if (after(TCP_SKB_CB(skb)->end_seq, tp->high_seq))
+		if (after(TCP_SKB_CB(skb)->end_seq, loss_high))
 			break;
 
 		oldcnt = cnt;
@@ -3033,19 +3031,10 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
 	if (tcp_check_sack_reneging(sk, flag))
 		return;
 
-	/* C. Process data loss notification, provided it is valid. */
-	if (tcp_is_fack(tp) && (flag & FLAG_DATA_LOST) &&
-	    before(tp->snd_una, tp->high_seq) &&
-	    icsk->icsk_ca_state != TCP_CA_Open &&
-	    tp->fackets_out > tp->reordering) {
-		tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering, 0);
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSS);
-	}
-
-	/* D. Check consistency of the current state. */
+	/* C. Check consistency of the current state. */
 	tcp_verify_left_out(tp);
 
-	/* E. Check state exit conditions. State can be terminated
+	/* D. Check state exit conditions. State can be terminated
 	 *    when high_seq is ACKed. */
 	if (icsk->icsk_ca_state == TCP_CA_Open) {
 		WARN_ON(tp->retrans_out != 0);
@@ -3077,7 +3066,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
 		}
 	}
 
-	/* F. Process state. */
+	/* E. Process state. */
 	switch (icsk->icsk_ca_state) {
 	case TCP_CA_Recovery:
 		if (!(flag & FLAG_SND_UNA_ADVANCED)) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1eb4ad57670..337ba4cca05 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -631,7 +631,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
 	arg.iov[0].iov_len  = sizeof(rep.th);
 
 #ifdef CONFIG_TCP_MD5SIG
-	key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
+	key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->saddr) : NULL;
 	if (key) {
 		rep.opt[0] = htonl((TCPOPT_NOP << 24) |
 				   (TCPOPT_NOP << 16) |