1 files changed, 72 insertions, 81 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index da2c3b8794f2..53300fa2359f 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -441,10 +441,7 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
 			*ptr++ = htonl(sp[this_sack].end_seq);
 		}
 
-		if (tp->rx_opt.dsack) {
-			tp->rx_opt.dsack = 0;
-			tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks;
-		}
+		tp->rx_opt.dsack = 0;
 	}
 }
 
@@ -550,6 +547,7 @@ static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
 	struct tcp_skb_cb *tcb = skb ? TCP_SKB_CB(skb) : NULL;
 	struct tcp_sock *tp = tcp_sk(sk);
 	unsigned size = 0;
+	unsigned int eff_sacks;
 
 #ifdef CONFIG_TCP_MD5SIG
 	*md5 = tp->af_specific->md5_lookup(sk, sk);
@@ -568,10 +566,11 @@ static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
 		size += TCPOLEN_TSTAMP_ALIGNED;
 	}
 
-	if (unlikely(tp->rx_opt.eff_sacks)) {
+	eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
+	if (unlikely(eff_sacks)) {
 		const unsigned remaining = MAX_TCP_OPTION_SPACE - size;
 		opts->num_sack_blocks =
-			min_t(unsigned, tp->rx_opt.eff_sacks,
+			min_t(unsigned, eff_sacks,
 			      (remaining - TCPOLEN_SACK_BASE_ALIGNED) /
 			      TCPOLEN_SACK_PERBLOCK);
 		size += TCPOLEN_SACK_BASE_ALIGNED +
@@ -663,10 +662,14 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	th->urg_ptr		= 0;
 
 	/* The urg_mode check is necessary during a below snd_una win probe */
-	if (unlikely(tcp_urg_mode(tp) &&
-		     between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
-		th->urg_ptr		= htons(tp->snd_up - tcb->seq);
-		th->urg			= 1;
+	if (unlikely(tcp_urg_mode(tp) && before(tcb->seq, tp->snd_up))) {
+		if (before(tp->snd_up, tcb->seq + 0x10000)) {
+			th->urg_ptr = htons(tp->snd_up - tcb->seq);
+			th->urg = 1;
+		} else if (after(tcb->seq + 0xFFFF, tp->snd_nxt)) {
+			th->urg_ptr = 0xFFFF;
+			th->urg = 1;
+		}
 	}
 
 	tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
@@ -751,6 +754,36 @@ static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb,
 		tp->fackets_out -= decr;
 }
 
+/* Pcount in the middle of the write queue got changed, we need to do various
+ * tweaks to fix counters
+ */
+static void tcp_adjust_pcount(struct sock *sk, struct sk_buff *skb, int decr)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	tp->packets_out -= decr;
+
+	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
+		tp->sacked_out -= decr;
+	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
+		tp->retrans_out -= decr;
+	if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)
+		tp->lost_out -= decr;
+
+	/* Reno case is special. Sigh... */
+	if (tcp_is_reno(tp) && decr > 0)
+		tp->sacked_out -= min_t(u32, tp->sacked_out, decr);
+
+	tcp_adjust_fackets_out(sk, skb, decr);
+
+	if (tp->lost_skb_hint &&
+	    before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->lost_skb_hint)->seq) &&
+	    (tcp_is_fack(tp) || TCP_SKB_CB(skb)->sacked))
+		tp->lost_cnt_hint -= decr;
+
+	tcp_verify_left_out(tp);
+}
+
 /* Function to create two new TCP segments.  Shrinks the given segment
  * to the specified size and appends a new segment with the rest of the
  * packet to the list.  This won't be called frequently, I hope.
@@ -763,11 +796,10 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
 	struct sk_buff *buff;
 	int nsize, old_factor;
 	int nlen;
-	u16 flags;
+	u8 flags;
 
 	BUG_ON(len > skb->len);
 
-	tcp_clear_retrans_hints_partial(tp);
 	nsize = skb_headlen(skb) - len;
 	if (nsize < 0)
 		nsize = 0;
@@ -834,22 +866,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
 		int diff = old_factor - tcp_skb_pcount(skb) -
 			tcp_skb_pcount(buff);
 
-		tp->packets_out -= diff;
-
-		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
-			tp->sacked_out -= diff;
-		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
-			tp->retrans_out -= diff;
-
-		if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)
-			tp->lost_out -= diff;
-
-		/* Adjust Reno SACK estimate. */
-		if (tcp_is_reno(tp) && diff > 0) {
-			tcp_dec_pcount_approx_int(&tp->sacked_out, diff);
-			tcp_verify_left_out(tp);
-		}
-		tcp_adjust_fackets_out(sk, skb, diff);
+		if (diff)
+			tcp_adjust_pcount(sk, skb, diff);
 	}
 
 	/* Link BUFF into the send queue. */
@@ -913,7 +931,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 	 * factor and mss.
 	 */
 	if (tcp_skb_pcount(skb) > 1)
-		tcp_set_skb_tso_segs(sk, skb, tcp_current_mss(sk, 1));
+		tcp_set_skb_tso_segs(sk, skb, tcp_current_mss(sk));
 
 	return 0;
 }
@@ -974,15 +992,6 @@ void tcp_mtup_init(struct sock *sk)
 	icsk->icsk_mtup.probe_size = 0;
 }
 
-/* Bound MSS / TSO packet size with the half of the window */
-static int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
-{
-	if (tp->max_window && pktsize > (tp->max_window >> 1))
-		return max(tp->max_window >> 1, 68U - tp->tcp_header_len);
-	else
-		return pktsize;
-}
-
 /* This function synchronize snd mss to current pmtu/exthdr set.
 
    tp->rx_opt.user_mss is mss set by user by TCP_MAXSEG. It does NOT counts
@@ -1029,22 +1038,17 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 /* Compute the current effective MSS, taking SACKs and IP options,
  * and even PMTU discovery events into account.
  */
-unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
+unsigned int tcp_current_mss(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct dst_entry *dst = __sk_dst_get(sk);
 	u32 mss_now;
-	u16 xmit_size_goal;
-	int doing_tso = 0;
 	unsigned header_len;
 	struct tcp_out_options opts;
 	struct tcp_md5sig_key *md5;
 
 	mss_now = tp->mss_cache;
 
-	if (large_allowed && sk_can_gso(sk))
-		doing_tso = 1;
-
 	if (dst) {
 		u32 mtu = dst_mtu(dst);
 		if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
@@ -1062,19 +1066,6 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 		mss_now -= delta;
 	}
 
-	xmit_size_goal = mss_now;
-
-	if (doing_tso) {
-		xmit_size_goal = ((sk->sk_gso_max_size - 1) -
-				  inet_csk(sk)->icsk_af_ops->net_header_len -
-				  inet_csk(sk)->icsk_ext_hdr_len -
-				  tp->tcp_header_len);
-
-		xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
-		xmit_size_goal -= (xmit_size_goal % mss_now);
-	}
-	tp->xmit_size_goal = xmit_size_goal;
-
 	return mss_now;
 }
 
@@ -1256,7 +1247,7 @@ int tcp_may_send_now(struct sock *sk)
 	struct sk_buff *skb = tcp_send_head(sk);
 
 	return (skb &&
-		tcp_snd_test(sk, skb, tcp_current_mss(sk, 1),
+		tcp_snd_test(sk, skb, tcp_current_mss(sk),
 			     (tcp_skb_is_last(sk, skb) ?
 			      tp->nonagle : TCP_NAGLE_PUSH)));
 }
@@ -1273,7 +1264,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 {
 	struct sk_buff *buff;
 	int nlen = skb->len - len;
-	u16 flags;
+	u8 flags;
 
 	/* All of a TSO frame must be composed of paged data.  */
 	if (skb->len != skb->data_len)
@@ -1352,6 +1343,10 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 	if (limit >= sk->sk_gso_max_size)
 		goto send_now;
 
+	/* Middle in queue won't get any more data, full sendable already? */
+	if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len))
+		goto send_now;
+
 	if (sysctl_tcp_tso_win_divisor) {
 		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
 
@@ -1405,11 +1400,11 @@ static int tcp_mtu_probe(struct sock *sk)
 	    icsk->icsk_mtup.probe_size ||
 	    inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
 	    tp->snd_cwnd < 11 ||
-	    tp->rx_opt.eff_sacks)
+	    tp->rx_opt.num_sacks || tp->rx_opt.dsack)
 		return -1;
 
 	/* Very simple search strategy: just double the MSS. */
-	mss_now = tcp_current_mss(sk, 0);
+	mss_now = tcp_current_mss(sk);
 	probe_size = 2 * tp->mss_cache;
 	size_needed = probe_size + (tp->reordering + 1) * tp->mss_cache;
 	if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high)) {
@@ -1754,11 +1749,9 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *next_skb = tcp_write_queue_next(sk, skb);
 	int skb_size, next_skb_size;
-	u16 flags;
 
 	skb_size = skb->len;
 	next_skb_size = next_skb->len;
-	flags = TCP_SKB_CB(skb)->flags;
 
 	BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1);
 
@@ -1778,30 +1771,21 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
 	/* Update sequence range on original skb. */
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
 
-	/* Merge over control information. */
-	flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
-	TCP_SKB_CB(skb)->flags = flags;
+	/* Merge over control information. This moves PSH/FIN etc. over */
+	TCP_SKB_CB(skb)->flags |= TCP_SKB_CB(next_skb)->flags;
 
 	/* All done, get rid of second SKB and account for it so
 	 * packet counting does not break.
 	 */
 	TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;
-	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_RETRANS)
-		tp->retrans_out -= tcp_skb_pcount(next_skb);
-	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_LOST)
-		tp->lost_out -= tcp_skb_pcount(next_skb);
-	/* Reno case is special. Sigh... */
-	if (tcp_is_reno(tp) && tp->sacked_out)
-		tcp_dec_pcount_approx(&tp->sacked_out, next_skb);
-
-	tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb));
-	tp->packets_out -= tcp_skb_pcount(next_skb);
 
 	/* changed transmit queue under us so clear hints */
 	tcp_clear_retrans_hints_partial(tp);
 	if (next_skb == tp->retransmit_skb_hint)
 		tp->retransmit_skb_hint = skb;
 
+	tcp_adjust_pcount(sk, next_skb, tcp_skb_pcount(next_skb));
+
 	sk_wmem_free_skb(sk, next_skb);
 }
 
@@ -1894,7 +1878,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
 		return -EHOSTUNREACH; /* Routing failure or similar. */
 
-	cur_mss = tcp_current_mss(sk, 0);
+	cur_mss = tcp_current_mss(sk);
 
 	/* If receiver has shrunk his window, and skb is out of
 	 * new window, do not retransmit it. The exception is the
@@ -1908,6 +1892,13 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	if (skb->len > cur_mss) {
 		if (tcp_fragment(sk, skb, cur_mss, cur_mss))
 			return -ENOMEM; /* We'll try again later. */
+	} else {
+		int oldpcount = tcp_skb_pcount(skb);
+
+		if (unlikely(oldpcount > 1)) {
+			tcp_init_tso_segs(sk, skb, cur_mss);
+			tcp_adjust_pcount(sk, skb, oldpcount - tcp_skb_pcount(skb));
+		}
 	}
 
 	tcp_retrans_try_collapse(sk, skb, cur_mss);
@@ -2061,7 +2052,7 @@ begin_fwd:
 			goto begin_fwd;
 
 		} else if (!(sacked & TCPCB_LOST)) {
-			if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS))
+			if (hole == NULL && !(sacked & (TCPCB_SACKED_RETRANS|TCPCB_SACKED_ACKED)))
 				hole = skb;
 			continue;
 
@@ -2100,7 +2091,7 @@ void tcp_send_fin(struct sock *sk)
 	 * unsent frames.  But be careful about outgoing SACKS
 	 * and IP options.
 	 */
-	mss_now = tcp_current_mss(sk, 1);
+	mss_now = tcp_current_mss(sk);
 
 	if (tcp_send_head(sk) != NULL) {
 		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN;
@@ -2325,7 +2316,7 @@ static void tcp_connect_init(struct sock *sk)
 	sk->sk_err = 0;
 	sock_reset_flag(sk, SOCK_DONE);
 	tp->snd_wnd = 0;
-	tcp_init_wl(tp, tp->write_seq, 0);
+	tcp_init_wl(tp, 0);
 	tp->snd_una = tp->write_seq;
 	tp->snd_sml = tp->write_seq;
 	tp->snd_up = tp->write_seq;
@@ -2512,7 +2503,7 @@ int tcp_write_wakeup(struct sock *sk)
 	if ((skb = tcp_send_head(sk)) != NULL &&
 	    before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))) {
 		int err;
-		unsigned int mss = tcp_current_mss(sk, 0);
+		unsigned int mss = tcp_current_mss(sk);
 		unsigned int seg_size = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
 
 		if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))