1 files changed, 104 insertions, 80 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b4ed957f201a..406f320336e6 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -55,7 +55,7 @@ int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
 int sysctl_tcp_tso_win_divisor __read_mostly = 3;
 
 int sysctl_tcp_mtu_probing __read_mostly = 0;
-int sysctl_tcp_base_mss __read_mostly = 512;
+int sysctl_tcp_base_mss __read_mostly = TCP_BASE_MSS;
 
 /* By default, RFC2861 behavior.  */
 int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
@@ -119,9 +119,13 @@ static __u16 tcp_advertise_mss(struct sock *sk)
 	struct dst_entry *dst = __sk_dst_get(sk);
 	int mss = tp->advmss;
 
-	if (dst && dst_metric(dst, RTAX_ADVMSS) < mss) {
-		mss = dst_metric(dst, RTAX_ADVMSS);
-		tp->advmss = mss;
+	if (dst) {
+		unsigned int metric = dst_metric_advmss(dst);
+
+		if (metric < mss) {
+			mss = metric;
+			tp->advmss = mss;
+		}
 	}
 
 	return (__u16)mss;
@@ -224,29 +228,28 @@ void tcp_select_initial_window(int __space, __u32 mss,
 		}
 	}
 
-	/* Set initial window to value enough for senders,
-	 * following RFC2414. Senders, not following this RFC,
-	 * will be satisfied with 2.
+	/* Set initial window to a value enough for senders starting with
+	 * initial congestion window of TCP_DEFAULT_INIT_RCVWND. Place
+	 * a limit on the initial window when mss is larger than 1460.
 	 */
 	if (mss > (1 << *rcv_wscale)) {
-		int init_cwnd = 4;
-		if (mss > 1460 * 3)
-			init_cwnd = 2;
-		else if (mss > 1460)
-			init_cwnd = 3;
+		int init_cwnd = TCP_DEFAULT_INIT_RCVWND;
+		if (mss > 1460)
+			init_cwnd =
+			max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2);
 		/* when initializing use the value from init_rcv_wnd
 		 * rather than the default from above
 		 */
-		if (init_rcv_wnd &&
-		    (*rcv_wnd > init_rcv_wnd * mss))
-			*rcv_wnd = init_rcv_wnd * mss;
-		else if (*rcv_wnd > init_cwnd * mss)
-			*rcv_wnd = init_cwnd * mss;
+		if (init_rcv_wnd)
+			*rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss);
+		else
+			*rcv_wnd = min(*rcv_wnd, init_cwnd * mss);
 	}
 
 	/* Set the clamp no higher than max representable value */
 	(*window_clamp) = min(65535U << (*rcv_wscale), *window_clamp);
 }
+EXPORT_SYMBOL(tcp_select_initial_window);
 
 /* Chose a new window to advertise, update state in tcp_sock for the
  * socket, and return result with RFC1323 scaling applied.  The return
@@ -294,9 +297,9 @@ static u16 tcp_select_window(struct sock *sk)
 /* Packet ECN state for a SYN-ACK */
 static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
 {
-	TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
+	TCP_SKB_CB(skb)->flags &= ~TCPHDR_CWR;
 	if (!(tp->ecn_flags & TCP_ECN_OK))
-		TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
+		TCP_SKB_CB(skb)->flags &= ~TCPHDR_ECE;
 }
 
 /* Packet ECN state for a SYN.  */
@@ -306,7 +309,7 @@ static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
 
 	tp->ecn_flags = 0;
 	if (sysctl_tcp_ecn == 1) {
-		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR;
+		TCP_SKB_CB(skb)->flags |= TCPHDR_ECE | TCPHDR_CWR;
 		tp->ecn_flags = TCP_ECN_OK;
 	}
 }
@@ -361,7 +364,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
 	skb_shinfo(skb)->gso_type = 0;
 
 	TCP_SKB_CB(skb)->seq = seq;
-	if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN))
+	if (flags & (TCPHDR_SYN | TCPHDR_FIN))
 		seq++;
 	TCP_SKB_CB(skb)->end_seq = seq;
 }
@@ -391,27 +394,30 @@ struct tcp_out_options {
  */
 static u8 tcp_cookie_size_check(u8 desired)
 {
-	if (desired > 0) {
+	int cookie_size;
+
+	if (desired > 0)
 		/* previously specified */
 		return desired;
-	}
-	if (sysctl_tcp_cookie_size <= 0) {
+
+	cookie_size = ACCESS_ONCE(sysctl_tcp_cookie_size);
+	if (cookie_size <= 0)
 		/* no default specified */
 		return 0;
-	}
-	if (sysctl_tcp_cookie_size <= TCP_COOKIE_MIN) {
+
+	if (cookie_size <= TCP_COOKIE_MIN)
 		/* value too small, specify minimum */
 		return TCP_COOKIE_MIN;
-	}
-	if (sysctl_tcp_cookie_size >= TCP_COOKIE_MAX) {
+
+	if (cookie_size >= TCP_COOKIE_MAX)
 		/* value too large, specify maximum */
 		return TCP_COOKIE_MAX;
-	}
-	if (0x1 & sysctl_tcp_cookie_size) {
+
+	if (cookie_size & 1)
 		/* 8-bit multiple, illegal, fix it */
-		return (u8)(sysctl_tcp_cookie_size + 0x1);
-	}
-	return (u8)sysctl_tcp_cookie_size;
+		cookie_size++;
+
+	return (u8)cookie_size;
 }
 
 /* Write previously computed TCP options to the packet.
@@ -820,15 +826,18 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	tcb = TCP_SKB_CB(skb);
 	memset(&opts, 0, sizeof(opts));
 
-	if (unlikely(tcb->flags & TCPCB_FLAG_SYN))
+	if (unlikely(tcb->flags & TCPHDR_SYN))
 		tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
 	else
 		tcp_options_size = tcp_established_options(sk, skb, &opts,
 							   &md5);
 	tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
 
-	if (tcp_packets_in_flight(tp) == 0)
+	if (tcp_packets_in_flight(tp) == 0) {
 		tcp_ca_event(sk, CA_EVENT_TX_START);
+		skb->ooo_okay = 1;
+	} else
+		skb->ooo_okay = 0;
 
 	skb_push(skb, tcp_header_size);
 	skb_reset_transport_header(skb);
@@ -843,7 +852,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	*(((__be16 *)th) + 6)	= htons(((tcp_header_size >> 2) << 12) |
 					tcb->flags);
 
-	if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+	if (unlikely(tcb->flags & TCPHDR_SYN)) {
 		/* RFC1323: The window in SYN & SYN/ACK segments
 		 * is never scaled.
 		 */
@@ -866,7 +875,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	}
 
 	tcp_options_write((__be32 *)(th + 1), tp, &opts);
-	if (likely((tcb->flags & TCPCB_FLAG_SYN) == 0))
+	if (likely((tcb->flags & TCPHDR_SYN) == 0))
 		TCP_ECN_send(sk, skb, tcp_header_size);
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -880,7 +889,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
 	icsk->icsk_af_ops->send_check(sk, skb);
 
-	if (likely(tcb->flags & TCPCB_FLAG_ACK))
+	if (likely(tcb->flags & TCPHDR_ACK))
 		tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
 
 	if (skb->len != tcp_header_size)
@@ -1023,7 +1032,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
 
 	/* PSH and FIN should only be set in the second packet. */
 	flags = TCP_SKB_CB(skb)->flags;
-	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+	TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
 	TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
 
@@ -1189,6 +1198,7 @@ void tcp_mtup_init(struct sock *sk)
 	icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
 	icsk->icsk_mtup.probe_size = 0;
 }
+EXPORT_SYMBOL(tcp_mtup_init);
 
 /* This function synchronize snd mss to current pmtu/exthdr set.
 
@@ -1232,6 +1242,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 
 	return mss_now;
 }
+EXPORT_SYMBOL(tcp_sync_mss);
 
 /* Compute the current effective MSS, taking SACKs and IP options,
  * and even PMTU discovery events into account.
@@ -1328,8 +1339,7 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
 	u32 in_flight, cwnd;
 
 	/* Don't be strict about the congestion window for the final FIN.  */
-	if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
-	    tcp_skb_pcount(skb) == 1)
+	if ((TCP_SKB_CB(skb)->flags & TCPHDR_FIN) && tcp_skb_pcount(skb) == 1)
 		return 1;
 
 	in_flight = tcp_packets_in_flight(tp);
@@ -1340,7 +1350,7 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
 	return 0;
 }
 
-/* Intialize TSO state of a skb.
+/* Initialize TSO state of a skb.
  * This must be invoked the first time we consider transmitting
  * SKB onto the wire.
  */
@@ -1374,9 +1384,9 @@ static inline int tcp_nagle_check(const struct tcp_sock *tp,
 				  const struct sk_buff *skb,
 				  unsigned mss_now, int nonagle)
 {
-	return (skb->len < mss_now &&
+	return skb->len < mss_now &&
 		((nonagle & TCP_NAGLE_CORK) ||
-		 (!nonagle && tp->packets_out && tcp_minshall_check(tp))));
+		 (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
 }
 
 /* Return non-zero if the Nagle test allows this packet to be
@@ -1398,7 +1408,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
 	 * Nagle can be ignored during F-RTO too (see RFC4138).
 	 */
 	if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
-	    (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
+	    (TCP_SKB_CB(skb)->flags & TCPHDR_FIN))
 		return 1;
 
 	if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
@@ -1447,10 +1457,10 @@ int tcp_may_send_now(struct sock *sk)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb = tcp_send_head(sk);
 
-	return (skb &&
+	return skb &&
 		tcp_snd_test(sk, skb, tcp_current_mss(sk),
 			     (tcp_skb_is_last(sk, skb) ?
-			      tp->nonagle : TCP_NAGLE_PUSH)));
+			      tp->nonagle : TCP_NAGLE_PUSH));
 }
 
 /* Trim TSO SKB to LEN bytes, put the remaining data into a new packet
@@ -1461,7 +1471,7 @@ int tcp_may_send_now(struct sock *sk)
  * packet has never been sent out before (and thus is not cloned).
  */
 static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
-			unsigned int mss_now)
+			unsigned int mss_now, gfp_t gfp)
 {
 	struct sk_buff *buff;
 	int nlen = skb->len - len;
@@ -1471,7 +1481,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 	if (skb->len != skb->data_len)
 		return tcp_fragment(sk, skb, len, mss_now);
 
-	buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC);
+	buff = sk_stream_alloc_skb(sk, 0, gfp);
 	if (unlikely(buff == NULL))
 		return -ENOMEM;
 
@@ -1487,7 +1497,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 
 	/* PSH and FIN should only be set in the second packet. */
 	flags = TCP_SKB_CB(skb)->flags;
-	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+	TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
 
 	/* This packet was never sent out yet, so no SACK bits. */
@@ -1517,8 +1527,9 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 	struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	u32 send_win, cong_win, limit, in_flight;
+	int win_divisor;
 
-	if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
+	if (TCP_SKB_CB(skb)->flags & TCPHDR_FIN)
 		goto send_now;
 
 	if (icsk->icsk_ca_state != TCP_CA_Open)
@@ -1548,13 +1559,14 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 	if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len))
 		goto send_now;
 
-	if (sysctl_tcp_tso_win_divisor) {
+	win_divisor = ACCESS_ONCE(sysctl_tcp_tso_win_divisor);
+	if (win_divisor) {
 		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
 
 		/* If at least some fraction of a window is available,
 		 * just use it.
 		 */
-		chunk /= sysctl_tcp_tso_win_divisor;
+		chunk /= win_divisor;
 		if (limit >= chunk)
 			goto send_now;
 	} else {
@@ -1644,7 +1656,7 @@ static int tcp_mtu_probe(struct sock *sk)
 
 	TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
 	TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
-	TCP_SKB_CB(nskb)->flags = TCPCB_FLAG_ACK;
+	TCP_SKB_CB(nskb)->flags = TCPHDR_ACK;
 	TCP_SKB_CB(nskb)->sacked = 0;
 	nskb->csum = 0;
 	nskb->ip_summed = skb->ip_summed;
@@ -1669,7 +1681,7 @@ static int tcp_mtu_probe(struct sock *sk)
 			sk_wmem_free_skb(sk, skb);
 		} else {
 			TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
-						   ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+						   ~(TCPHDR_FIN|TCPHDR_PSH);
 			if (!skb_shinfo(skb)->nr_frags) {
 				skb_pull(skb, copy);
 				if (skb->ip_summed != CHECKSUM_PARTIAL)
@@ -1769,7 +1781,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 						    cwnd_quota);
 
 		if (skb->len > limit &&
-		    unlikely(tso_fragment(sk, skb, limit, mss_now)))
+		    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
 			break;
 
 		TCP_SKB_CB(skb)->when = tcp_time_stamp;
@@ -2020,7 +2032,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 
 	if (!sysctl_tcp_retrans_collapse)
 		return;
-	if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)
+	if (TCP_SKB_CB(skb)->flags & TCPHDR_SYN)
 		return;
 
 	tcp_for_write_queue_from_safe(skb, tmp, sk) {
@@ -2112,7 +2124,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	 * since it is cheap to do so and saves bytes on the network.
 	 */
 	if (skb->len > 0 &&
-	    (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+	    (TCP_SKB_CB(skb)->flags & TCPHDR_FIN) &&
 	    tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
 		if (!pskb_trim(skb, 0)) {
 			/* Reuse, even though it does some unnecessary work */
@@ -2208,6 +2220,9 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 	int mib_idx;
 	int fwd_rexmitting = 0;
 
+	if (!tp->packets_out)
+		return;
+
 	if (!tp->lost_out)
 		tp->retransmit_high = tp->snd_una;
 
@@ -2301,7 +2316,7 @@ void tcp_send_fin(struct sock *sk)
 	mss_now = tcp_current_mss(sk);
 
 	if (tcp_send_head(sk) != NULL) {
-		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN;
+		TCP_SKB_CB(skb)->flags |= TCPHDR_FIN;
 		TCP_SKB_CB(skb)->end_seq++;
 		tp->write_seq++;
 	} else {
@@ -2318,7 +2333,7 @@ void tcp_send_fin(struct sock *sk)
 		skb_reserve(skb, MAX_TCP_HEADER);
 		/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
 		tcp_init_nondata_skb(skb, tp->write_seq,
-				     TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
+				     TCPHDR_ACK | TCPHDR_FIN);
 		tcp_queue_skb(sk, skb);
 	}
 	__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
@@ -2343,7 +2358,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
 	/* Reserve space for headers and prepare control bits. */
 	skb_reserve(skb, MAX_TCP_HEADER);
 	tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
-			     TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
+			     TCPHDR_ACK | TCPHDR_RST);
 	/* Send it off. */
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
 	if (tcp_transmit_skb(sk, skb, 0, priority))
@@ -2363,11 +2378,11 @@ int tcp_send_synack(struct sock *sk)
 	struct sk_buff *skb;
 
 	skb = tcp_write_queue_head(sk);
-	if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)) {
+	if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPHDR_SYN)) {
 		printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
 		return -EFAULT;
 	}
-	if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_ACK)) {
+	if (!(TCP_SKB_CB(skb)->flags & TCPHDR_ACK)) {
 		if (skb_cloned(skb)) {
 			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
 			if (nskb == NULL)
@@ -2381,7 +2396,7 @@ int tcp_send_synack(struct sock *sk)
 			skb = nskb;
 		}
 
-		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ACK;
+		TCP_SKB_CB(skb)->flags |= TCPHDR_ACK;
 		TCP_ECN_send_synack(tcp_sk(sk), skb);
 	}
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
@@ -2416,7 +2431,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
 	skb_dst_set(skb, dst_clone(dst));
 
-	mss = dst_metric(dst, RTAX_ADVMSS);
+	mss = dst_metric_advmss(dst);
 	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
 		mss = tp->rx_opt.user_mss;
 
@@ -2424,6 +2439,12 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 		__u8 rcv_wscale;
 		/* Set this up on the first call only */
 		req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
+
+		/* limit the window selection if the user enforce a smaller rx buffer */
+		if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
+		    (req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0))
+			req->window_clamp = tcp_full_space(sk);
+
 		/* tcp_full_space because it is guaranteed to be the first packet */
 		tcp_select_initial_window(tcp_full_space(sk),
 			mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
@@ -2460,7 +2481,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	 * not even correctly set)
 	 */
 	tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
-			     TCPCB_FLAG_SYN | TCPCB_FLAG_ACK);
+			     TCPHDR_SYN | TCPHDR_ACK);
 
 	if (OPTION_COOKIE_EXTENSION & opts.options) {
 		if (s_data_desired) {
@@ -2515,6 +2536,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
 	return skb;
 }
+EXPORT_SYMBOL(tcp_make_synack);
 
 /* Do all connect socket setups that can be done AF independent. */
 static void tcp_connect_init(struct sock *sk)
@@ -2543,12 +2565,17 @@ static void tcp_connect_init(struct sock *sk)
 
 	if (!tp->window_clamp)
 		tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
-	tp->advmss = dst_metric(dst, RTAX_ADVMSS);
+	tp->advmss = dst_metric_advmss(dst);
 	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss)
 		tp->advmss = tp->rx_opt.user_mss;
 
 	tcp_initialize_rcv_mss(sk);
 
+	/* limit the window selection if the user enforce a smaller rx buffer */
+	if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
+	    (tp->window_clamp > tcp_full_space(sk) || tp->window_clamp == 0))
+		tp->window_clamp = tcp_full_space(sk);
+
 	tcp_select_initial_window(tcp_full_space(sk),
 				  tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
 				  &tp->rcv_wnd,
@@ -2581,6 +2608,7 @@ int tcp_connect(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *buff;
+	int err;
 
 	tcp_connect_init(sk);
 
@@ -2592,7 +2620,7 @@ int tcp_connect(struct sock *sk)
 	skb_reserve(buff, MAX_TCP_HEADER);
 
 	tp->snd_nxt = tp->write_seq;
-	tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN);
+	tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
 	TCP_ECN_send_syn(sk, buff);
 
 	/* Send it off. */
@@ -2603,7 +2631,9 @@ int tcp_connect(struct sock *sk)
 	sk->sk_wmem_queued += buff->truesize;
 	sk_mem_charge(sk, buff->truesize);
 	tp->packets_out += tcp_skb_pcount(buff);
-	tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+	err = tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+	if (err == -ECONNREFUSED)
+		return err;
 
 	/* We change tp->snd_nxt after the tcp_transmit_skb() call
 	 * in order to make this packet get counted in tcpOutSegs.
@@ -2617,6 +2647,7 @@ int tcp_connect(struct sock *sk)
 				  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
 	return 0;
 }
+EXPORT_SYMBOL(tcp_connect);
 
 /* Send out a delayed ack, the caller does the policy checking
  * to see if we should even be here.  See tcp_input.c:tcp_ack_snd_check()
@@ -2698,7 +2729,7 @@ void tcp_send_ack(struct sock *sk)
 
 	/* Reserve space for headers and prepare control bits. */
 	skb_reserve(buff, MAX_TCP_HEADER);
-	tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPCB_FLAG_ACK);
+	tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK);
 
 	/* Send it off, this clears delayed acks for us. */
 	TCP_SKB_CB(buff)->when = tcp_time_stamp;
@@ -2732,7 +2763,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	 * end to send an ack.  Don't queue or clone SKB, just
 	 * send it.
 	 */
-	tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
+	tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK);
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
 	return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
 }
@@ -2762,13 +2793,13 @@ int tcp_write_wakeup(struct sock *sk)
 		if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
 		    skb->len > mss) {
 			seg_size = min(seg_size, mss);
-			TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+			TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
 			if (tcp_fragment(sk, skb, seg_size, mss))
 				return -1;
 		} else if (!tcp_skb_pcount(skb))
 			tcp_set_skb_tso_segs(sk, skb, mss);
 
-		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+		TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
 		TCP_SKB_CB(skb)->when = tcp_time_stamp;
 		err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 		if (!err)
@@ -2821,10 +2852,3 @@ void tcp_send_probe0(struct sock *sk)
 					  TCP_RTO_MAX);
 	}
 }
-
-EXPORT_SYMBOL(tcp_select_initial_window);
-EXPORT_SYMBOL(tcp_connect);
-EXPORT_SYMBOL(tcp_make_synack);
-EXPORT_SYMBOL(tcp_simple_retransmit);
-EXPORT_SYMBOL(tcp_sync_mss);
-EXPORT_SYMBOL(tcp_mtup_init);