1 files changed, 79 insertions, 63 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8e5d1bcbd..bf0636da8 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -362,7 +362,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
 	/* Check #1 */
 	if (tp->rcv_ssthresh < tp->window_clamp &&
 	    (int)tp->rcv_ssthresh < tcp_space(sk) &&
-	    !sk_under_memory_pressure(sk)) {
+	    !tcp_under_memory_pressure(sk)) {
 		int incr;
 
 		/* Check #2. Increase window, if skb with such overhead
@@ -449,7 +449,7 @@ static void tcp_clamp_window(struct sock *sk)
 
 	if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
 	    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
-	    !sk_under_memory_pressure(sk) &&
+	    !tcp_under_memory_pressure(sk) &&
 	    sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
 		sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
 				    sysctl_tcp_rmem[2]);
@@ -1133,7 +1133,12 @@ static bool tcp_check_dsack(struct sock *sk, const struct sk_buff *ack_skb,
 struct tcp_sacktag_state {
 	int	reord;
 	int	fack_count;
-	long	rtt_us; /* RTT measured by SACKing never-retransmitted data */
+	/* Timestamps for earliest and latest never-retransmitted segment
+	 * that was SACKed. RTO needs the earliest RTT to stay conservative,
+	 * but congestion control should still get an accurate delay signal.
+	 */
+	struct skb_mstamp first_sackt;
+	struct skb_mstamp last_sackt;
 	int	flag;
 };
 
@@ -1236,14 +1241,9 @@ static u8 tcp_sacktag_one(struct sock *sk,
 							   state->reord);
 				if (!after(end_seq, tp->high_seq))
 					state->flag |= FLAG_ORIG_SACK_ACKED;
-				/* Pick the earliest sequence sacked for RTT */
-				if (state->rtt_us < 0) {
-					struct skb_mstamp now;
-
-					skb_mstamp_get(&now);
-					state->rtt_us = skb_mstamp_us_delta(&now,
-								xmit_time);
-				}
+				if (state->first_sackt.v64 == 0)
+					state->first_sackt = *xmit_time;
+				state->last_sackt = *xmit_time;
 			}
 
 			if (sacked & TCPCB_LOST) {
@@ -1319,16 +1319,12 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb,
 	 * code can come after this skb later on it's better to keep
 	 * setting gso_size to something.
 	 */
-	if (!skb_shinfo(prev)->gso_size) {
-		skb_shinfo(prev)->gso_size = mss;
-		skb_shinfo(prev)->gso_type = sk->sk_gso_type;
-	}
+	if (!TCP_SKB_CB(prev)->tcp_gso_size)
+		TCP_SKB_CB(prev)->tcp_gso_size = mss;
 
 	/* CHECKME: To clear or not to clear? Mimics normal skb currently */
-	if (tcp_skb_pcount(skb) <= 1) {
-		skb_shinfo(skb)->gso_size = 0;
-		skb_shinfo(skb)->gso_type = 0;
-	}
+	if (tcp_skb_pcount(skb) <= 1)
+		TCP_SKB_CB(skb)->tcp_gso_size = 0;
 
 	/* Difference in this won't matter, both ACKed by the same cumul. ACK */
 	TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS);
@@ -1637,7 +1633,7 @@ static int tcp_sack_cache_ok(const struct tcp_sock *tp, const struct tcp_sack_bl
 
 static int
 tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
-			u32 prior_snd_una, long *sack_rtt_us)
+			u32 prior_snd_una, struct tcp_sacktag_state *state)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	const unsigned char *ptr = (skb_transport_header(ack_skb) +
@@ -1645,7 +1641,6 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 	struct tcp_sack_block_wire *sp_wire = (struct tcp_sack_block_wire *)(ptr+2);
 	struct tcp_sack_block sp[TCP_NUM_SACKS];
 	struct tcp_sack_block *cache;
-	struct tcp_sacktag_state state;
 	struct sk_buff *skb;
 	int num_sacks = min(TCP_NUM_SACKS, (ptr[1] - TCPOLEN_SACK_BASE) >> 3);
 	int used_sacks;
@@ -1653,9 +1648,8 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 	int i, j;
 	int first_sack_index;
 
-	state.flag = 0;
-	state.reord = tp->packets_out;
-	state.rtt_us = -1L;
+	state->flag = 0;
+	state->reord = tp->packets_out;
 
 	if (!tp->sacked_out) {
 		if (WARN_ON(tp->fackets_out))
@@ -1666,7 +1660,7 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 	found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire,
 					 num_sacks, prior_snd_una);
 	if (found_dup_sack)
-		state.flag |= FLAG_DSACKING_ACK;
+		state->flag |= FLAG_DSACKING_ACK;
 
 	/* Eliminate too old ACKs, but take into
 	 * account more or less fresh ones, they can
@@ -1731,7 +1725,7 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 	}
 
 	skb = tcp_write_queue_head(sk);
-	state.fack_count = 0;
+	state->fack_count = 0;
 	i = 0;
 
 	if (!tp->sacked_out) {
@@ -1765,10 +1759,10 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 
 			/* Head todo? */
 			if (before(start_seq, cache->start_seq)) {
-				skb = tcp_sacktag_skip(skb, sk, &state,
+				skb = tcp_sacktag_skip(skb, sk, state,
 						       start_seq);
 				skb = tcp_sacktag_walk(skb, sk, next_dup,
-						       &state,
+						       state,
 						       start_seq,
 						       cache->start_seq,
 						       dup_sack);
@@ -1779,7 +1773,7 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 				goto advance_sp;
 
 			skb = tcp_maybe_skipping_dsack(skb, sk, next_dup,
-						       &state,
+						       state,
 						       cache->end_seq);
 
 			/* ...tail remains todo... */
@@ -1788,12 +1782,12 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 				skb = tcp_highest_sack(sk);
 				if (!skb)
 					break;
-				state.fack_count = tp->fackets_out;
+				state->fack_count = tp->fackets_out;
 				cache++;
 				goto walk;
 			}
 
-			skb = tcp_sacktag_skip(skb, sk, &state, cache->end_seq);
+			skb = tcp_sacktag_skip(skb, sk, state, cache->end_seq);
 			/* Check overlap against next cached too (past this one already) */
 			cache++;
 			continue;
@@ -1803,12 +1797,12 @@ tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
 			skb = tcp_highest_sack(sk);
 			if (!skb)
 				break;
-			state.fack_count = tp->fackets_out;
+			state->fack_count = tp->fackets_out;
 		}
-		skb = tcp_sacktag_skip(skb, sk, &state, start_seq);
+		skb = tcp_sacktag_skip(skb, sk, state, start_seq);
 
 walk:
-		skb = tcp_sacktag_walk(skb, sk, next_dup, &state,
+		skb = tcp_sacktag_walk(skb, sk, next_dup, state,
 				       start_seq, end_seq, dup_sack);
 
 advance_sp:
@@ -1823,9 +1817,9 @@ advance_sp:
 	for (j = 0; j < used_sacks; j++)
 		tp->recv_sack_cache[i++] = sp[j];
 
-	if ((state.reord < tp->fackets_out) &&
+	if ((state->reord < tp->fackets_out) &&
 	    ((inet_csk(sk)->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker))
-		tcp_update_reordering(sk, tp->fackets_out - state.reord, 0);
+		tcp_update_reordering(sk, tp->fackets_out - state->reord, 0);
 
 	tcp_mark_lost_retrans(sk);
 	tcp_verify_left_out(tp);
@@ -1837,8 +1831,7 @@ out:
 	WARN_ON((int)tp->retrans_out < 0);
 	WARN_ON((int)tcp_packets_in_flight(tp) < 0);
 #endif
-	*sack_rtt_us = state.rtt_us;
-	return state.flag;
+	return state->flag;
 }
 
 /* Limits sacked_out so that sum with lost_out isn't ever larger than
@@ -1927,14 +1920,13 @@ void tcp_enter_loss(struct sock *sk)
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
-	bool new_recovery = false;
+	bool new_recovery = icsk->icsk_ca_state < TCP_CA_Recovery;
 	bool is_reneg;			/* is receiver reneging on SACKs? */
 
 	/* Reduce ssthresh if it has not yet been made inside this window. */
 	if (icsk->icsk_ca_state <= TCP_CA_Disorder ||
 	    !after(tp->high_seq, tp->snd_una) ||
 	    (icsk->icsk_ca_state == TCP_CA_Loss && !icsk->icsk_retransmits)) {
-		new_recovery = true;
 		tp->prior_ssthresh = tcp_current_ssthresh(sk);
 		tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
 		tcp_ca_event(sk, CA_EVENT_LOSS);
@@ -2258,7 +2250,7 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
 			    (oldcnt >= packets))
 				break;
 
-			mss = skb_shinfo(skb)->gso_size;
+			mss = tcp_skb_mss(skb);
 			err = tcp_fragment(sk, skb, (packets - oldcnt) * mss,
 					   mss, GFP_ATOMIC);
 			if (err < 0)
@@ -2558,6 +2550,7 @@ void tcp_enter_cwr(struct sock *sk)
 		tcp_set_ca_state(sk, TCP_CA_CWR);
 	}
 }
+EXPORT_SYMBOL(tcp_enter_cwr);
 
 static void tcp_try_keep_open(struct sock *sk)
 {
@@ -3058,7 +3051,8 @@ static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb,
  * arrived at the other end.
  */
 static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
-			       u32 prior_snd_una, long sack_rtt_us)
+			       u32 prior_snd_una,
+			       struct tcp_sacktag_state *sack)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct skb_mstamp first_ackt, last_ackt, now;
@@ -3066,8 +3060,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 	u32 prior_sacked = tp->sacked_out;
 	u32 reord = tp->packets_out;
 	bool fully_acked = true;
-	long ca_seq_rtt_us = -1L;
+	long sack_rtt_us = -1L;
 	long seq_rtt_us = -1L;
+	long ca_rtt_us = -1L;
 	struct sk_buff *skb;
 	u32 pkts_acked = 0;
 	bool rtt_update;
@@ -3156,15 +3151,16 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 	skb_mstamp_get(&now);
 	if (likely(first_ackt.v64)) {
 		seq_rtt_us = skb_mstamp_us_delta(&now, &first_ackt);
-		ca_seq_rtt_us = skb_mstamp_us_delta(&now, &last_ackt);
+		ca_rtt_us = skb_mstamp_us_delta(&now, &last_ackt);
+	}
+	if (sack->first_sackt.v64) {
+		sack_rtt_us = skb_mstamp_us_delta(&now, &sack->first_sackt);
+		ca_rtt_us = skb_mstamp_us_delta(&now, &sack->last_sackt);
 	}
 
 	rtt_update = tcp_ack_update_rtt(sk, flag, seq_rtt_us, sack_rtt_us);
 
 	if (flag & FLAG_ACKED) {
-		const struct tcp_congestion_ops *ca_ops
-			= inet_csk(sk)->icsk_ca_ops;
-
 		tcp_rearm_rto(sk);
 		if (unlikely(icsk->icsk_mtup.probe_size &&
 			     !after(tp->mtu_probe.probe_seq_end, tp->snd_una))) {
@@ -3187,11 +3183,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 
 		tp->fackets_out -= min(pkts_acked, tp->fackets_out);
 
-		if (ca_ops->pkts_acked) {
-			long rtt_us = min_t(ulong, ca_seq_rtt_us, sack_rtt_us);
-			ca_ops->pkts_acked(sk, pkts_acked, rtt_us);
-		}
-
 	} else if (skb && rtt_update && sack_rtt_us >= 0 &&
 		   sack_rtt_us > skb_mstamp_us_delta(&now, &skb->skb_mstamp)) {
 		/* Do not re-arm RTO if the sack RTT is measured from data sent
@@ -3201,6 +3192,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
 		tcp_rearm_rto(sk);
 	}
 
+	if (icsk->icsk_ca_ops->pkts_acked)
+		icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked, ca_rtt_us);
+
 #if FASTRETRANS_DEBUG > 0
 	WARN_ON((int)tp->sacked_out < 0);
 	WARN_ON((int)tp->lost_out < 0);
@@ -3241,7 +3235,7 @@ static void tcp_ack_probe(struct sock *sk)
 		 * This function is not for random using!
 		 */
 	} else {
-		unsigned long when = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);
+		unsigned long when = tcp_probe0_when(sk, TCP_RTO_MAX);
 
 		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
 					  when, TCP_RTO_MAX);
@@ -3469,6 +3463,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_sacktag_state sack_state;
 	u32 prior_snd_una = tp->snd_una;
 	u32 ack_seq = TCP_SKB_CB(skb)->seq;
 	u32 ack = TCP_SKB_CB(skb)->ack_seq;
@@ -3477,7 +3472,8 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 	int prior_packets = tp->packets_out;
 	const int prior_unsacked = tp->packets_out - tp->sacked_out;
 	int acked = 0; /* Number of packets newly acked */
-	long sack_rtt_us = -1L;
+
+	sack_state.first_sackt.v64 = 0;
 
 	/* We very likely will need to access write queue head. */
 	prefetchw(sk->sk_write_queue.next);
@@ -3541,7 +3537,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 
 		if (TCP_SKB_CB(skb)->sacked)
 			flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
-							&sack_rtt_us);
+							&sack_state);
 
 		if (tcp_ecn_rcv_ecn_echo(tp, tcp_hdr(skb))) {
 			flag |= FLAG_ECE;
@@ -3566,7 +3562,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 	/* See if we can take anything off of the retransmit queue. */
 	acked = tp->packets_out;
 	flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una,
-				    sack_rtt_us);
+				    &sack_state);
 	acked -= tp->packets_out;
 
 	/* Advance cwnd if state allows */
@@ -3618,7 +3614,7 @@ old_ack:
 	 */
 	if (TCP_SKB_CB(skb)->sacked) {
 		flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
-						&sack_rtt_us);
+						&sack_state);
 		tcp_fastretrans_alert(sk, acked, prior_unsacked,
 				      is_dupack, flag);
 	}
@@ -4591,10 +4587,12 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 
 		if (eaten <= 0) {
 queue_and_out:
-			if (eaten < 0 &&
-			    tcp_try_rmem_schedule(sk, skb, skb->truesize))
-				goto drop;
-
+			if (eaten < 0) {
+				if (skb_queue_len(&sk->sk_receive_queue) == 0)
+					sk_forced_mem_schedule(sk, skb->truesize);
+				else if (tcp_try_rmem_schedule(sk, skb, skb->truesize))
+					goto drop;
+			}
 			eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
 		}
 		tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
@@ -4865,7 +4863,7 @@ static int tcp_prune_queue(struct sock *sk)
 
 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
 		tcp_clamp_window(sk);
-	else if (sk_under_memory_pressure(sk))
+	else if (tcp_under_memory_pressure(sk))
 		tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
 
 	tcp_collapse_ofo_queue(sk);
@@ -4909,7 +4907,7 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk)
 		return false;
 
 	/* If we are under global TCP memory pressure, do not expand.  */
-	if (sk_under_memory_pressure(sk))
+	if (tcp_under_memory_pressure(sk))
 		return false;
 
 	/* If we are under soft global TCP memory pressure, do not expand.  */
@@ -6153,6 +6151,23 @@ static bool tcp_syn_flood_action(struct sock *sk,
 	return want_cookie;
 }
 
+static void tcp_reqsk_record_syn(const struct sock *sk,
+				 struct request_sock *req,
+				 const struct sk_buff *skb)
+{
+	if (tcp_sk(sk)->save_syn) {
+		u32 len = skb_network_header_len(skb) + tcp_hdrlen(skb);
+		u32 *copy;
+
+		copy = kmalloc(len + sizeof(u32), GFP_ATOMIC);
+		if (copy) {
+			copy[0] = len;
+			memcpy(&copy[1], skb_network_header(skb), len);
+			req->saved_syn = copy;
+		}
+	}
+}
+
 int tcp_conn_request(struct request_sock_ops *rsk_ops,
 		     const struct tcp_request_sock_ops *af_ops,
 		     struct sock *sk, struct sk_buff *skb)
@@ -6285,6 +6300,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 		tcp_rsk(req)->tfo_listener = false;
 		af_ops->queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
 	}
+	tcp_reqsk_record_syn(sk, req, skb);
 
 	return 0;