X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fipv4%2Ftcp_output.c;h=cebe9aa918a355c039fe2f014a8a88cc88603e4e;hb=e905a9edab7f4f14f9213b52234e4a346c690911;hp=566045e58437e21cfc8ebaefc9f9056b3c1c01ae;hpb=35d59efd105b3b7c1b5878dcc9d1749f41f9740f;p=safe%2Fjmp%2Flinux-2.6

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 566045e..cebe9aa 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -43,16 +43,27 @@
 #include <linux/smp_lock.h>
 
 /* People can turn this off for buggy TCP's found in printers etc. */
-int sysctl_tcp_retrans_collapse = 1;
+int sysctl_tcp_retrans_collapse __read_mostly = 1;
+
+/* People can turn this on to  work with those rare, broken TCPs that
+ * interpret the window field as a signed quantity.
+ */
+int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
 
 /* This limits the percentage of the congestion window which we
  * will allow a single TSO frame to consume.  Building TSO frames
  * which are too large can cause TCP streams to be bursty.
  */
-int sysctl_tcp_tso_win_divisor = 3;
+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;
+
+/* By default, RFC2861 behavior.  */
+int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
 
-static inline void update_send_head(struct sock *sk, struct tcp_sock *tp,
-				    struct sk_buff *skb)
+static void update_send_head(struct sock *sk, struct tcp_sock *tp,
+			     struct sk_buff *skb)
 {
 	sk->sk_send_head = skb->next;
 	if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
@@ -105,47 +116,48 @@ static __u16 tcp_advertise_mss(struct sock *sk)
 
 /* RFC2861. Reset CWND after idle period longer RTO to "restart window".
  * This is the first part of cwnd validation mechanism. */
-static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
+static void tcp_cwnd_restart(struct sock *sk, struct dst_entry *dst)
 {
+	struct tcp_sock *tp = tcp_sk(sk);
 	s32 delta = tcp_time_stamp - tp->lsndtime;
 	u32 restart_cwnd = tcp_init_cwnd(tp, dst);
 	u32 cwnd = tp->snd_cwnd;
 
-	tcp_ca_event(tp, CA_EVENT_CWND_RESTART);
+	tcp_ca_event(sk, CA_EVENT_CWND_RESTART);
 
-	tp->snd_ssthresh = tcp_current_ssthresh(tp);
+	tp->snd_ssthresh = tcp_current_ssthresh(sk);
 	restart_cwnd = min(restart_cwnd, cwnd);
 
-	while ((delta -= tp->rto) > 0 && cwnd > restart_cwnd)
+	while ((delta -= inet_csk(sk)->icsk_rto) > 0 && cwnd > restart_cwnd)
 		cwnd >>= 1;
 	tp->snd_cwnd = max(cwnd, restart_cwnd);
 	tp->snd_cwnd_stamp = tcp_time_stamp;
 	tp->snd_cwnd_used = 0;
 }
 
-static inline void tcp_event_data_sent(struct tcp_sock *tp,
-				       struct sk_buff *skb, struct sock *sk)
+static void tcp_event_data_sent(struct tcp_sock *tp,
+				struct sk_buff *skb, struct sock *sk)
 {
-	u32 now = tcp_time_stamp;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	const u32 now = tcp_time_stamp;
 
-	if (!tp->packets_out && (s32)(now - tp->lsndtime) > tp->rto)
-		tcp_cwnd_restart(tp, __sk_dst_get(sk));
+	if (sysctl_tcp_slow_start_after_idle &&
+	    (!tp->packets_out && (s32)(now - tp->lsndtime) > icsk->icsk_rto))
+		tcp_cwnd_restart(sk, __sk_dst_get(sk));
 
 	tp->lsndtime = now;
 
 	/* If it is a reply for ato after last received
 	 * packet, enter pingpong mode.
 	 */
-	if ((u32)(now - tp->ack.lrcvtime) < tp->ack.ato)
-		tp->ack.pingpong = 1;
+	if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
+		icsk->icsk_ack.pingpong = 1;
 }
 
-static __inline__ void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
+static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	tcp_dec_quickack_mode(tp, pkts);
-	tcp_clear_xmit_timer(sk, TCP_TIME_DACK);
+	tcp_dec_quickack_mode(sk, pkts);
+	inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 }
 
 /* Determine a window scaling and initial window to offer.
@@ -171,18 +183,25 @@ void tcp_select_initial_window(int __space, __u32 mss,
 		space = (space / mss) * mss;
 
 	/* NOTE: offering an initial window larger than 32767
-	 * will break some buggy TCP stacks. We try to be nice.
-	 * If we are not window scaling, then this truncates
-	 * our initial window offering to 32k. There should also
-	 * be a sysctl option to stop being nice.
+	 * will break some buggy TCP stacks. If the admin tells us
+	 * it is likely we could be speaking with such a buggy stack
+	 * we will truncate our initial window offering to 32K-1
+	 * unless the remote has sent us a window scaling option,
+	 * which we interpret as a sign the remote TCP is not
+	 * misinterpreting the window field as a signed quantity.
 	 */
-	(*rcv_wnd) = min(space, MAX_TCP_WINDOW);
+	if (sysctl_tcp_workaround_signed_windows)
+		(*rcv_wnd) = min(space, MAX_TCP_WINDOW);
+	else
+		(*rcv_wnd) = space;
+
 	(*rcv_wscale) = 0;
 	if (wscale_ok) {
 		/* Set window scaling on max possible window
-		 * See RFC1323 for an explanation of the limit to 14 
+		 * See RFC1323 for an explanation of the limit to 14
 		 */
 		space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max);
+		space = min_t(u32, space, *window_clamp);
 		while (space > 65535 && (*rcv_wscale) < 14) {
 			space >>= 1;
 			(*rcv_wscale)++;
@@ -190,7 +209,7 @@ void tcp_select_initial_window(int __space, __u32 mss,
 	}
 
 	/* Set initial window to value enough for senders,
-	 * following RFC1414. Senders, not following this RFC,
+	 * following RFC2414. Senders, not following this RFC,
 	 * will be satisfied with 2.
 	 */
 	if (mss > (1<<*rcv_wscale)) {
@@ -212,7 +231,7 @@ void tcp_select_initial_window(int __space, __u32 mss,
  * value can be stuffed directly into th->window for an outgoing
  * frame.
  */
-static __inline__ u16 tcp_select_window(struct sock *sk)
+static u16 tcp_select_window(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	u32 cur_win = tcp_receive_window(tp);
@@ -235,7 +254,7 @@ static __inline__ u16 tcp_select_window(struct sock *sk)
 	/* Make sure we do not exceed the maximum possible
 	 * scaled window.
 	 */
-	if (!tp->rx_opt.rcv_wscale)
+	if (!tp->rx_opt.rcv_wscale && sysctl_tcp_workaround_signed_windows)
 		new_win = min(new_win, MAX_TCP_WINDOW);
 	else
 		new_win = min(new_win, (65535U << tp->rx_opt.rcv_wscale));
@@ -250,6 +269,111 @@ static __inline__ u16 tcp_select_window(struct sock *sk)
 	return new_win;
 }
 
+static void tcp_build_and_update_options(__be32 *ptr, struct tcp_sock *tp,
+					 __u32 tstamp, __u8 **md5_hash)
+{
+	if (tp->rx_opt.tstamp_ok) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_TIMESTAMP << 8) |
+			       TCPOLEN_TIMESTAMP);
+		*ptr++ = htonl(tstamp);
+		*ptr++ = htonl(tp->rx_opt.ts_recent);
+	}
+	if (tp->rx_opt.eff_sacks) {
+		struct tcp_sack_block *sp = tp->rx_opt.dsack ? tp->duplicate_sack : tp->selective_acks;
+		int this_sack;
+
+		*ptr++ = htonl((TCPOPT_NOP  << 24) |
+			       (TCPOPT_NOP  << 16) |
+			       (TCPOPT_SACK <<  8) |
+			       (TCPOLEN_SACK_BASE + (tp->rx_opt.eff_sacks *
+						     TCPOLEN_SACK_PERBLOCK)));
+		for(this_sack = 0; this_sack < tp->rx_opt.eff_sacks; this_sack++) {
+			*ptr++ = htonl(sp[this_sack].start_seq);
+			*ptr++ = htonl(sp[this_sack].end_seq);
+		}
+		if (tp->rx_opt.dsack) {
+			tp->rx_opt.dsack = 0;
+			tp->rx_opt.eff_sacks--;
+		}
+	}
+#ifdef CONFIG_TCP_MD5SIG
+	if (md5_hash) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_MD5SIG << 8) |
+			       TCPOLEN_MD5SIG);
+		*md5_hash = (__u8 *)ptr;
+	}
+#endif
+}
+
+/* Construct a tcp options header for a SYN or SYN_ACK packet.
+ * If this is every changed make sure to change the definition of
+ * MAX_SYN_SIZE to match the new maximum number of options that you
+ * can generate.
+ *
+ * Note - that with the RFC2385 TCP option, we make room for the
+ * 16 byte MD5 hash. This will be filled in later, so the pointer for the
+ * location to be filled is passed back up.
+ */
+static void tcp_syn_build_options(__be32 *ptr, int mss, int ts, int sack,
+				  int offer_wscale, int wscale, __u32 tstamp,
+				  __u32 ts_recent, __u8 **md5_hash)
+{
+	/* We always get an MSS option.
+	 * The option bytes which will be seen in normal data
+	 * packets should timestamps be used, must be in the MSS
+	 * advertised.  But we subtract them from tp->mss_cache so
+	 * that calculations in tcp_sendmsg are simpler etc.
+	 * So account for this fact here if necessary.  If we
+	 * don't do this correctly, as a receiver we won't
+	 * recognize data packets as being full sized when we
+	 * should, and thus we won't abide by the delayed ACK
+	 * rules correctly.
+	 * SACKs don't matter, we never delay an ACK when we
+	 * have any of those going out.
+	 */
+	*ptr++ = htonl((TCPOPT_MSS << 24) | (TCPOLEN_MSS << 16) | mss);
+	if (ts) {
+		if(sack)
+			*ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
+				       (TCPOLEN_SACK_PERM << 16) |
+				       (TCPOPT_TIMESTAMP << 8) |
+				       TCPOLEN_TIMESTAMP);
+		else
+			*ptr++ = htonl((TCPOPT_NOP << 24) |
+				       (TCPOPT_NOP << 16) |
+				       (TCPOPT_TIMESTAMP << 8) |
+				       TCPOLEN_TIMESTAMP);
+		*ptr++ = htonl(tstamp);		/* TSVAL */
+		*ptr++ = htonl(ts_recent);	/* TSECR */
+	} else if(sack)
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_SACK_PERM << 8) |
+			       TCPOLEN_SACK_PERM);
+	if (offer_wscale)
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_WINDOW << 16) |
+			       (TCPOLEN_WINDOW << 8) |
+			       (wscale));
+#ifdef CONFIG_TCP_MD5SIG
+	/*
+	 * If MD5 is enabled, then we set the option, and include the size
+	 * (always 18). The actual MD5 hash is added just before the
+	 * packet is sent.
+	 */
+	if (md5_hash) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_MD5SIG << 8) |
+			       TCPOLEN_MD5SIG);
+		*md5_hash = (__u8 *) ptr;
+	}
+#endif
+}
 
 /* This routine actually transmits TCP packets queued in by
  * tcp_do_sendmsg().  This is used by both the initial
@@ -262,128 +386,176 @@ static __inline__ u16 tcp_select_window(struct sock *sk)
  * We are working here with either a clone of the original
  * SKB, or a fresh unique copy made by the retransmit engine.
  */
-static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
+static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, gfp_t gfp_mask)
 {
-	if (skb != NULL) {
-		struct inet_sock *inet = inet_sk(sk);
-		struct tcp_sock *tp = tcp_sk(sk);
-		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
-		int tcp_header_size = tp->tcp_header_len;
-		struct tcphdr *th;
-		int sysctl_flags;
-		int err;
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct inet_sock *inet;
+	struct tcp_sock *tp;
+	struct tcp_skb_cb *tcb;
+	int tcp_header_size;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *md5;
+	__u8 *md5_hash_location;
+#endif
+	struct tcphdr *th;
+	int sysctl_flags;
+	int err;
 
-		BUG_ON(!tcp_skb_pcount(skb));
+	BUG_ON(!skb || !tcp_skb_pcount(skb));
+
+	/* If congestion control is doing timestamping, we must
+	 * take such a timestamp before we potentially clone/copy.
+	 */
+	if (icsk->icsk_ca_ops->rtt_sample)
+		__net_timestamp(skb);
+
+	if (likely(clone_it)) {
+		if (unlikely(skb_cloned(skb)))
+			skb = pskb_copy(skb, gfp_mask);
+		else
+			skb = skb_clone(skb, gfp_mask);
+		if (unlikely(!skb))
+			return -ENOBUFS;
+	}
+
+	inet = inet_sk(sk);
+	tp = tcp_sk(sk);
+	tcb = TCP_SKB_CB(skb);
+	tcp_header_size = tp->tcp_header_len;
 
 #define SYSCTL_FLAG_TSTAMPS	0x1
 #define SYSCTL_FLAG_WSCALE	0x2
 #define SYSCTL_FLAG_SACK	0x4
 
-		/* If congestion control is doing timestamping */
-		if (tp->ca_ops->rtt_sample)
-			do_gettimeofday(&skb->stamp);
-
-		sysctl_flags = 0;
-		if (tcb->flags & TCPCB_FLAG_SYN) {
-			tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
-			if(sysctl_tcp_timestamps) {
-				tcp_header_size += TCPOLEN_TSTAMP_ALIGNED;
-				sysctl_flags |= SYSCTL_FLAG_TSTAMPS;
-			}
-			if(sysctl_tcp_window_scaling) {
-				tcp_header_size += TCPOLEN_WSCALE_ALIGNED;
-				sysctl_flags |= SYSCTL_FLAG_WSCALE;
-			}
-			if(sysctl_tcp_sack) {
-				sysctl_flags |= SYSCTL_FLAG_SACK;
-				if(!(sysctl_flags & SYSCTL_FLAG_TSTAMPS))
-					tcp_header_size += TCPOLEN_SACKPERM_ALIGNED;
-			}
-		} else if (tp->rx_opt.eff_sacks) {
-			/* A SACK is 2 pad bytes, a 2 byte header, plus
-			 * 2 32-bit sequence numbers for each SACK block.
-			 */
-			tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED +
-					    (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
+	sysctl_flags = 0;
+	if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+		tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
+		if(sysctl_tcp_timestamps) {
+			tcp_header_size += TCPOLEN_TSTAMP_ALIGNED;
+			sysctl_flags |= SYSCTL_FLAG_TSTAMPS;
 		}
-		
-		if (tcp_packets_in_flight(tp) == 0)
-			tcp_ca_event(tp, CA_EVENT_TX_START);
-
-		th = (struct tcphdr *) skb_push(skb, tcp_header_size);
-		skb->h.th = th;
-		skb_set_owner_w(skb, sk);
-
-		/* Build TCP header and checksum it. */
-		th->source		= inet->sport;
-		th->dest		= inet->dport;
-		th->seq			= htonl(tcb->seq);
-		th->ack_seq		= htonl(tp->rcv_nxt);
-		*(((__u16 *)th) + 6)	= htons(((tcp_header_size >> 2) << 12) | tcb->flags);
-		if (tcb->flags & TCPCB_FLAG_SYN) {
-			/* RFC1323: The window in SYN & SYN/ACK segments
-			 * is never scaled.
-			 */
-			th->window	= htons(tp->rcv_wnd);
-		} else {
-			th->window	= htons(tcp_select_window(sk));
+		if (sysctl_tcp_window_scaling) {
+			tcp_header_size += TCPOLEN_WSCALE_ALIGNED;
+			sysctl_flags |= SYSCTL_FLAG_WSCALE;
 		}
-		th->check		= 0;
-		th->urg_ptr		= 0;
-
-		if (tp->urg_mode &&
-		    between(tp->snd_up, tcb->seq+1, tcb->seq+0xFFFF)) {
-			th->urg_ptr		= htons(tp->snd_up-tcb->seq);
-			th->urg			= 1;
+		if (sysctl_tcp_sack) {
+			sysctl_flags |= SYSCTL_FLAG_SACK;
+			if (!(sysctl_flags & SYSCTL_FLAG_TSTAMPS))
+				tcp_header_size += TCPOLEN_SACKPERM_ALIGNED;
 		}
+	} else if (unlikely(tp->rx_opt.eff_sacks)) {
+		/* A SACK is 2 pad bytes, a 2 byte header, plus
+		 * 2 32-bit sequence numbers for each SACK block.
+		 */
+		tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED +
+				    (tp->rx_opt.eff_sacks *
+				     TCPOLEN_SACK_PERBLOCK));
+	}
 
-		if (tcb->flags & TCPCB_FLAG_SYN) {
-			tcp_syn_build_options((__u32 *)(th + 1),
-					      tcp_advertise_mss(sk),
-					      (sysctl_flags & SYSCTL_FLAG_TSTAMPS),
-					      (sysctl_flags & SYSCTL_FLAG_SACK),
-					      (sysctl_flags & SYSCTL_FLAG_WSCALE),
-					      tp->rx_opt.rcv_wscale,
-					      tcb->when,
-		      			      tp->rx_opt.ts_recent);
-		} else {
-			tcp_build_and_update_options((__u32 *)(th + 1),
-						     tp, tcb->when);
+	if (tcp_packets_in_flight(tp) == 0)
+		tcp_ca_event(sk, CA_EVENT_TX_START);
 
-			TCP_ECN_send(sk, tp, skb, tcp_header_size);
-		}
-		tp->af_specific->send_check(sk, th, skb->len, skb);
+#ifdef CONFIG_TCP_MD5SIG
+	/*
+	 * Are we doing MD5 on this segment? If so - make
+	 * room for it.
+	 */
+	md5 = tp->af_specific->md5_lookup(sk, sk);
+	if (md5)
+		tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
+	th = (struct tcphdr *) skb_push(skb, tcp_header_size);
+	skb->h.th = th;
+	skb_set_owner_w(skb, sk);
+
+	/* Build TCP header and checksum it. */
+	th->source		= inet->sport;
+	th->dest		= inet->dport;
+	th->seq			= htonl(tcb->seq);
+	th->ack_seq		= htonl(tp->rcv_nxt);
+	*(((__be16 *)th) + 6)	= htons(((tcp_header_size >> 2) << 12) |
+					tcb->flags);
+
+	if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+		/* RFC1323: The window in SYN & SYN/ACK segments
+		 * is never scaled.
+		 */
+		th->window	= htons(tp->rcv_wnd);
+	} else {
+		th->window	= htons(tcp_select_window(sk));
+	}
+	th->check		= 0;
+	th->urg_ptr		= 0;
+
+	if (unlikely(tp->urg_mode &&
+		     between(tp->snd_up, tcb->seq+1, tcb->seq+0xFFFF))) {
+		th->urg_ptr		= htons(tp->snd_up-tcb->seq);
+		th->urg			= 1;
+	}
 
-		if (tcb->flags & TCPCB_FLAG_ACK)
-			tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
+	if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+		tcp_syn_build_options((__be32 *)(th + 1),
+				      tcp_advertise_mss(sk),
+				      (sysctl_flags & SYSCTL_FLAG_TSTAMPS),
+				      (sysctl_flags & SYSCTL_FLAG_SACK),
+				      (sysctl_flags & SYSCTL_FLAG_WSCALE),
+				      tp->rx_opt.rcv_wscale,
+				      tcb->when,
+				      tp->rx_opt.ts_recent,
+
+#ifdef CONFIG_TCP_MD5SIG
+				      md5 ? &md5_hash_location :
+#endif
+				      NULL);
+	} else {
+		tcp_build_and_update_options((__be32 *)(th + 1),
+					     tp, tcb->when,
+#ifdef CONFIG_TCP_MD5SIG
+					     md5 ? &md5_hash_location :
+#endif
+					     NULL);
+		TCP_ECN_send(sk, tp, skb, tcp_header_size);
+	}
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Calculate the MD5 hash, as we have all we need now */
+	if (md5) {
+		tp->af_specific->calc_md5_hash(md5_hash_location,
+					       md5,
+					       sk, NULL, NULL,
+					       skb->h.th,
+					       sk->sk_protocol,
+					       skb->len);
+	}
+#endif
 
-		if (skb->len != tcp_header_size)
-			tcp_event_data_sent(tp, skb, sk);
+	icsk->icsk_af_ops->send_check(sk, skb->len, skb);
 
+	if (likely(tcb->flags & TCPCB_FLAG_ACK))
+		tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
+
+	if (skb->len != tcp_header_size)
+		tcp_event_data_sent(tp, skb, sk);
+
+	if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
 		TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
-		err = tp->af_specific->queue_xmit(skb, 0);
-		if (err <= 0)
-			return err;
+	err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+	if (likely(err <= 0))
+		return err;
 
-		tcp_enter_cwr(tp);
+	tcp_enter_cwr(sk);
+
+	return net_xmit_eval(err);
 
-		/* NET_XMIT_CN is special. It does not guarantee,
-		 * that this packet is lost. It tells that device
-		 * is about to start to drop packets or already
-		 * drops some packets of the same priority and
-		 * invokes us to send less aggressively.
-		 */
-		return err == NET_XMIT_CN ? 0 : err;
-	}
-	return -ENOBUFS;
 #undef SYSCTL_FLAG_TSTAMPS
 #undef SYSCTL_FLAG_WSCALE
 #undef SYSCTL_FLAG_SACK
 }
 
 
-/* This routine just queue's the buffer 
+/* This routine just queue's the buffer
  *
  * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames,
  * otherwise socket can stall.
@@ -405,35 +577,40 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
 
 static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
 {
-	if (skb->len <= mss_now ||
-	    !(sk->sk_route_caps & NETIF_F_TSO)) {
+	if (skb->len <= mss_now || !sk_can_gso(sk)) {
 		/* Avoid the costly divide in the normal
 		 * non-TSO case.
 		 */
-		skb_shinfo(skb)->tso_segs = 1;
-		skb_shinfo(skb)->tso_size = 0;
+		skb_shinfo(skb)->gso_segs = 1;
+		skb_shinfo(skb)->gso_size = 0;
+		skb_shinfo(skb)->gso_type = 0;
 	} else {
 		unsigned int factor;
 
 		factor = skb->len + (mss_now - 1);
 		factor /= mss_now;
-		skb_shinfo(skb)->tso_segs = factor;
-		skb_shinfo(skb)->tso_size = mss_now;
+		skb_shinfo(skb)->gso_segs = factor;
+		skb_shinfo(skb)->gso_size = mss_now;
+		skb_shinfo(skb)->gso_type = sk->sk_gso_type;
 	}
 }
 
 /* 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. 
+ * packet to the list.  This won't be called frequently, I hope.
  * Remember, these are still headerless SKBs at this point.
  */
-static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss_now)
+int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss_now)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *buff;
-	int nsize;
+	int nsize, old_factor;
+	int nlen;
 	u16 flags;
 
+	BUG_ON(len > skb->len);
+
+	clear_all_retrans_hints(tp);
 	nsize = skb_headlen(skb) - len;
 	if (nsize < 0)
 		nsize = 0;
@@ -447,7 +624,11 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
 	buff = sk_stream_alloc_skb(sk, nsize, GFP_ATOMIC);
 	if (buff == NULL)
 		return -ENOMEM; /* We'll just try again later. */
+
 	sk_charge_skb(sk, buff);
+	nlen = skb->len - len - nsize;
+	buff->truesize += nlen;
+	skb->truesize -= nlen;
 
 	/* Correct the sequence numbers. */
 	TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len;
@@ -458,12 +639,10 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
 	flags = TCP_SKB_CB(skb)->flags;
 	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
-	TCP_SKB_CB(buff)->sacked =
-		(TCP_SKB_CB(skb)->sacked &
-		 (TCPCB_LOST | TCPCB_EVER_RETRANS | TCPCB_AT_TAIL));
+	TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
 	TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
 
-	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_HW) {
+	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
 		/* Copy and checksum data tail into the new buffer. */
 		buff->csum = csum_partial_copy_nocheck(skb->data + len, skb_put(buff, nsize),
 						       nsize, 0);
@@ -472,7 +651,7 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
 
 		skb->csum = csum_block_sub(skb->csum, buff->csum, len);
 	} else {
-		skb->ip_summed = CHECKSUM_HW;
+		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb_split(skb, buff, len);
 	}
 
@@ -482,30 +661,51 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
 	 * skbs, which it never sent before. --ANK
 	 */
 	TCP_SKB_CB(buff)->when = TCP_SKB_CB(skb)->when;
-	buff->stamp = skb->stamp;
+	buff->tstamp = skb->tstamp;
 
-	if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
-		tp->lost_out -= tcp_skb_pcount(skb);
-		tp->left_out -= tcp_skb_pcount(skb);
-	}
+	old_factor = tcp_skb_pcount(skb);
 
 	/* Fix up tso_factor for both original and new SKB.  */
 	tcp_set_skb_tso_segs(sk, skb, mss_now);
 	tcp_set_skb_tso_segs(sk, buff, mss_now);
 
-	if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
-		tp->lost_out += tcp_skb_pcount(skb);
-		tp->left_out += tcp_skb_pcount(skb);
-	}
+	/* If this packet has been sent out already, we must
+	 * adjust the various packet counters.
+	 */
+	if (!before(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) {
+		int diff = old_factor - tcp_skb_pcount(skb) -
+			tcp_skb_pcount(buff);
 
-	if (TCP_SKB_CB(buff)->sacked&TCPCB_LOST) {
-		tp->lost_out += tcp_skb_pcount(buff);
-		tp->left_out += 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;
+			tp->left_out -= diff;
+		}
+
+		if (diff > 0) {
+			/* Adjust Reno SACK estimate. */
+			if (!tp->rx_opt.sack_ok) {
+				tp->sacked_out -= diff;
+				if ((int)tp->sacked_out < 0)
+					tp->sacked_out = 0;
+				tcp_sync_left_out(tp);
+			}
+
+			tp->fackets_out -= diff;
+			if ((int)tp->fackets_out < 0)
+				tp->fackets_out = 0;
+		}
 	}
 
 	/* Link BUFF into the send queue. */
 	skb_header_release(buff);
-	__skb_append(skb, buff);
+	__skb_append(skb, buff, &sk->sk_write_queue);
 
 	return 0;
 }
@@ -514,7 +714,7 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
  * eventually). The difference is that pulled data not copied, but
  * immediately discarded.
  */
-static unsigned char *__pskb_trim_head(struct sk_buff *skb, int len)
+static void __pskb_trim_head(struct sk_buff *skb, int len)
 {
 	int i, k, eat;
 
@@ -539,7 +739,6 @@ static unsigned char *__pskb_trim_head(struct sk_buff *skb, int len)
 	skb->tail = skb->data;
 	skb->data_len -= len;
 	skb->len = skb->data_len;
-	return skb->tail;
 }
 
 int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
@@ -548,15 +747,14 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 	    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
 		return -ENOMEM;
 
-	if (len <= skb_headlen(skb)) {
+	/* If len == headlen, we avoid __skb_pull to preserve alignment. */
+	if (unlikely(len < skb_headlen(skb)))
 		__skb_pull(skb, len);
-	} else {
-		if (__pskb_trim_head(skb, len-skb_headlen(skb)) == NULL)
-			return -ENOMEM;
-	}
+	else
+		__pskb_trim_head(skb, len - skb_headlen(skb));
 
 	TCP_SKB_CB(skb)->seq += len;
-	skb->ip_summed = CHECKSUM_HW;
+	skb->ip_summed = CHECKSUM_PARTIAL;
 
 	skb->truesize	     -= len;
 	sk->sk_wmem_queued   -= len;
@@ -572,16 +770,72 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 	return 0;
 }
 
+/* Not accounting for SACKs here. */
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int mss_now;
+
+	/* Calculate base mss without TCP options:
+	   It is MMS_S - sizeof(tcphdr) of rfc1122
+	 */
+	mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
+
+	/* Clamp it (mss_clamp does not include tcp options) */
+	if (mss_now > tp->rx_opt.mss_clamp)
+		mss_now = tp->rx_opt.mss_clamp;
+
+	/* Now subtract optional transport overhead */
+	mss_now -= icsk->icsk_ext_hdr_len;
+
+	/* Then reserve room for full set of TCP options and 8 bytes of data */
+	if (mss_now < 48)
+		mss_now = 48;
+
+	/* Now subtract TCP options size, not including SACKs */
+	mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
+
+	return mss_now;
+}
+
+/* Inverse of above */
+int tcp_mss_to_mtu(struct sock *sk, int mss)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int mtu;
+
+	mtu = mss +
+	      tp->tcp_header_len +
+	      icsk->icsk_ext_hdr_len +
+	      icsk->icsk_af_ops->net_header_len;
+
+	return mtu;
+}
+
+void tcp_mtup_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	icsk->icsk_mtup.enabled = sysctl_tcp_mtu_probing > 1;
+	icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) +
+			       icsk->icsk_af_ops->net_header_len;
+	icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
+	icsk->icsk_mtup.probe_size = 0;
+}
+
 /* 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
    for TCP options, but includes only bare TCP header.
 
    tp->rx_opt.mss_clamp is mss negotiated at connection setup.
-   It is minumum of user_mss and mss received with SYN.
+   It is minimum of user_mss and mss received with SYN.
    It also does not include TCP options.
 
-   tp->pmtu_cookie is last pmtu, seen by this function.
+   inet_csk(sk)->icsk_pmtu_cookie is last pmtu, seen by this function.
 
    tp->mss_cache is current effective sending mss, including
    all tcp options except for SACKs. It is evaluated,
@@ -591,40 +845,29 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
    NOTE1. rfc1122 clearly states that advertised MSS
    DOES NOT include either tcp or ip options.
 
-   NOTE2. tp->pmtu_cookie and tp->mss_cache are READ ONLY outside
-   this function.			--ANK (980731)
+   NOTE2. inet_csk(sk)->icsk_pmtu_cookie and tp->mss_cache
+   are READ ONLY outside this function.		--ANK (980731)
  */
 
 unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	int mss_now;
 
-	/* Calculate base mss without TCP options:
-	   It is MMS_S - sizeof(tcphdr) of rfc1122
-	 */
-	mss_now = pmtu - tp->af_specific->net_header_len - sizeof(struct tcphdr);
-
-	/* Clamp it (mss_clamp does not include tcp options) */
-	if (mss_now > tp->rx_opt.mss_clamp)
-		mss_now = tp->rx_opt.mss_clamp;
-
-	/* Now subtract optional transport overhead */
-	mss_now -= tp->ext_header_len;
+	if (icsk->icsk_mtup.search_high > pmtu)
+		icsk->icsk_mtup.search_high = pmtu;
 
-	/* Then reserve room for full set of TCP options and 8 bytes of data */
-	if (mss_now < 48)
-		mss_now = 48;
-
-	/* Now subtract TCP options size, not including SACKs */
-	mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
+	mss_now = tcp_mtu_to_mss(sk, pmtu);
 
 	/* Bound mss with half of window */
 	if (tp->max_window && mss_now > (tp->max_window>>1))
 		mss_now = max((tp->max_window>>1), 68U - tp->tcp_header_len);
 
 	/* And store cached results */
-	tp->pmtu_cookie = pmtu;
+	icsk->icsk_pmtu_cookie = pmtu;
+	if (icsk->icsk_mtup.enabled)
+		mss_now = min(mss_now, tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low));
 	tp->mss_cache = mss_now;
 
 	return mss_now;
@@ -647,14 +890,12 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 
 	mss_now = tp->mss_cache;
 
-	if (large_allowed &&
-	    (sk->sk_route_caps & NETIF_F_TSO) &&
-	    !tp->urg_mode)
+	if (large_allowed && sk_can_gso(sk) && !tp->urg_mode)
 		doing_tso = 1;
 
 	if (dst) {
 		u32 mtu = dst_mtu(dst);
-		if (mtu != tp->pmtu_cookie)
+		if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
 			mss_now = tcp_sync_mss(sk, mtu);
 	}
 
@@ -662,12 +903,18 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 		mss_now -= (TCPOLEN_SACK_BASE_ALIGNED +
 			    (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
 
+#ifdef CONFIG_TCP_MD5SIG
+	if (tp->af_specific->md5_lookup(sk, sk))
+		mss_now -= TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
 	xmit_size_goal = mss_now;
 
 	if (doing_tso) {
-		xmit_size_goal = 65535 -
-			tp->af_specific->net_header_len -
-			tp->ext_header_len - tp->tcp_header_len;
+		xmit_size_goal = (65535 -
+				  inet_csk(sk)->icsk_af_ops->net_header_len -
+				  inet_csk(sk)->icsk_ext_hdr_len -
+				  tp->tcp_header_len);
 
 		if (tp->max_window &&
 		    (xmit_size_goal > (tp->max_window >> 1)))
@@ -683,7 +930,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 
 /* Congestion window validation. (RFC2861) */
 
-static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
+static void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
 {
 	__u32 packets_out = tp->packets_out;
 
@@ -696,7 +943,7 @@ static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
 		if (tp->packets_out > tp->snd_cwnd_used)
 			tp->snd_cwnd_used = tp->packets_out;
 
-		if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto)
+		if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
 			tcp_cwnd_application_limited(sk);
 	}
 }
@@ -718,7 +965,8 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, struct sk_buff *sk
 	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)
+	if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+	    tcp_skb_pcount(skb) == 1)
 		return 1;
 
 	in_flight = tcp_packets_in_flight(tp);
@@ -732,13 +980,13 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, struct sk_buff *sk
 /* This must be invoked the first time we consider transmitting
  * SKB onto the wire.
  */
-static inline int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
+static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
 {
 	int tso_segs = tcp_skb_pcount(skb);
 
 	if (!tso_segs ||
 	    (tso_segs > 1 &&
-	     skb_shinfo(skb)->tso_size != mss_now)) {
+	     tcp_skb_mss(skb) != mss_now)) {
 		tcp_set_skb_tso_segs(sk, skb, mss_now);
 		tso_segs = tcp_skb_pcount(skb);
 	}
@@ -760,7 +1008,7 @@ static inline int tcp_minshall_check(const struct tcp_sock *tp)
  */
 
 static inline int tcp_nagle_check(const struct tcp_sock *tp,
-				  const struct sk_buff *skb, 
+				  const struct sk_buff *skb,
 				  unsigned mss_now, int nonagle)
 {
 	return (skb->len < mss_now &&
@@ -830,7 +1078,7 @@ static unsigned int tcp_snd_test(struct sock *sk, struct sk_buff *skb,
 	return cwnd_quota;
 }
 
-static inline int tcp_skb_is_last(const struct sock *sk, 
+static inline int tcp_skb_is_last(const struct sock *sk,
 				  const struct sk_buff *skb)
 {
 	return skb->next == (struct sk_buff *)&sk->sk_write_queue;
@@ -868,7 +1116,8 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 	if (unlikely(buff == NULL))
 		return -ENOMEM;
 
-	buff->truesize = nlen;
+	sk_charge_skb(sk, buff);
+	buff->truesize += nlen;
 	skb->truesize -= nlen;
 
 	/* Correct the sequence numbers. */
@@ -884,7 +1133,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 	/* This packet was never sent out yet, so no SACK bits. */
 	TCP_SKB_CB(buff)->sacked = 0;
 
-	buff->ip_summed = skb->ip_summed = CHECKSUM_HW;
+	buff->ip_summed = skb->ip_summed = CHECKSUM_PARTIAL;
 	skb_split(skb, buff, len);
 
 	/* Fix up tso_factor for both original and new SKB.  */
@@ -893,7 +1142,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 
 	/* Link BUFF into the send queue. */
 	skb_header_release(buff);
-	__skb_append(skb, buff);
+	__skb_append(skb, buff, &sk->sk_write_queue);
 
 	return 0;
 }
@@ -905,13 +1154,18 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
  */
 static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_buff *skb)
 {
+	const struct inet_connection_sock *icsk = inet_csk(sk);
 	u32 send_win, cong_win, limit, in_flight;
 
 	if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
-		return 0;
+		goto send_now;
 
-	if (tp->ca_state != TCP_CA_Open)
-		return 0;
+	if (icsk->icsk_ca_state != TCP_CA_Open)
+		goto send_now;
+
+	/* Defer for less than two clock ticks. */
+	if (!tp->tso_deferred && ((jiffies<<1)>>1) - (tp->tso_deferred>>1) > 1)
+		goto send_now;
 
 	in_flight = tcp_packets_in_flight(tp);
 
@@ -925,9 +1179,9 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 
 	limit = min(send_win, cong_win);
 
-	/* If sk_send_head can be sent fully now, just do it.  */
-	if (skb->len <= limit)
-		return 0;
+	/* If a full-sized TSO skb can be sent, do it. */
+	if (limit >= 65536)
+		goto send_now;
 
 	if (sysctl_tcp_tso_win_divisor) {
 		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
@@ -937,7 +1191,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 		 */
 		chunk /= sysctl_tcp_tso_win_divisor;
 		if (limit >= chunk)
-			return 0;
+			goto send_now;
 	} else {
 		/* Different approach, try not to defer past a single
 		 * ACK.  Receiver should ACK every other full sized
@@ -945,13 +1199,152 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 		 * then send now.
 		 */
 		if (limit > tcp_max_burst(tp) * tp->mss_cache)
-			return 0;
+			goto send_now;
 	}
 
 	/* Ok, it looks like it is advisable to defer.  */
+	tp->tso_deferred = 1 | (jiffies<<1);
+
 	return 1;
+
+send_now:
+	tp->tso_deferred = 0;
+	return 0;
+}
+
+/* Create a new MTU probe if we are ready.
+ * Returns 0 if we should wait to probe (no cwnd available),
+ *         1 if a probe was sent,
+ *         -1 otherwise */
+static int tcp_mtu_probe(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sk_buff *skb, *nskb, *next;
+	int len;
+	int probe_size;
+	unsigned int pif;
+	int copy;
+	int mss_now;
+
+	/* Not currently probing/verifying,
+	 * not in recovery,
+	 * have enough cwnd, and
+	 * not SACKing (the variable headers throw things off) */
+	if (!icsk->icsk_mtup.enabled ||
+	    icsk->icsk_mtup.probe_size ||
+	    inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
+	    tp->snd_cwnd < 11 ||
+	    tp->rx_opt.eff_sacks)
+		return -1;
+
+	/* Very simple search strategy: just double the MSS. */
+	mss_now = tcp_current_mss(sk, 0);
+	probe_size = 2*tp->mss_cache;
+	if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high)) {
+		/* TODO: set timer for probe_converge_event */
+		return -1;
+	}
+
+	/* Have enough data in the send queue to probe? */
+	len = 0;
+	if ((skb = sk->sk_send_head) == NULL)
+		return -1;
+	while ((len += skb->len) < probe_size && !tcp_skb_is_last(sk, skb))
+		skb = skb->next;
+	if (len < probe_size)
+		return -1;
+
+	/* Receive window check. */
+	if (after(TCP_SKB_CB(skb)->seq + probe_size, tp->snd_una + tp->snd_wnd)) {
+		if (tp->snd_wnd < probe_size)
+			return -1;
+		else
+			return 0;
+	}
+
+	/* Do we need to wait to drain cwnd? */
+	pif = tcp_packets_in_flight(tp);
+	if (pif + 2 > tp->snd_cwnd) {
+		/* With no packets in flight, don't stall. */
+		if (pif == 0)
+			return -1;
+		else
+			return 0;
+	}
+
+	/* We're allowed to probe.  Build it now. */
+	if ((nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC)) == NULL)
+		return -1;
+	sk_charge_skb(sk, nskb);
+
+	skb = sk->sk_send_head;
+	__skb_insert(nskb, skb->prev, skb, &sk->sk_write_queue);
+	sk->sk_send_head = nskb;
+
+	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)->sacked = 0;
+	nskb->csum = 0;
+	nskb->ip_summed = skb->ip_summed;
+
+	len = 0;
+	while (len < probe_size) {
+		next = skb->next;
+
+		copy = min_t(int, skb->len, probe_size - len);
+		if (nskb->ip_summed)
+			skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
+		else
+			nskb->csum = skb_copy_and_csum_bits(skb, 0,
+					 skb_put(nskb, copy), copy, nskb->csum);
+
+		if (skb->len <= copy) {
+			/* We've eaten all the data from this skb.
+			 * Throw it away. */
+			TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags;
+			__skb_unlink(skb, &sk->sk_write_queue);
+			sk_stream_free_skb(sk, skb);
+		} else {
+			TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
+						   ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+			if (!skb_shinfo(skb)->nr_frags) {
+				skb_pull(skb, copy);
+				if (skb->ip_summed != CHECKSUM_PARTIAL)
+					skb->csum = csum_partial(skb->data, skb->len, 0);
+			} else {
+				__pskb_trim_head(skb, copy);
+				tcp_set_skb_tso_segs(sk, skb, mss_now);
+			}
+			TCP_SKB_CB(skb)->seq += copy;
+		}
+
+		len += copy;
+		skb = next;
+	}
+	tcp_init_tso_segs(sk, nskb, nskb->len);
+
+	/* We're ready to send.  If this fails, the probe will
+	 * be resegmented into mss-sized pieces by tcp_write_xmit(). */
+	TCP_SKB_CB(nskb)->when = tcp_time_stamp;
+	if (!tcp_transmit_skb(sk, nskb, 1, GFP_ATOMIC)) {
+		/* Decrement cwnd here because we are sending
+		* effectively two packets. */
+		tp->snd_cwnd--;
+		update_send_head(sk, tp, nskb);
+
+		icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
+		tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
+		tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
+
+		return 1;
+	}
+
+	return -1;
 }
 
+
 /* This routine writes packets to the network.  It advances the
  * send_head.  This happens as incoming acks open up the remote
  * window for us.
@@ -965,6 +1358,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
 	struct sk_buff *skb;
 	unsigned int tso_segs, sent_pkts;
 	int cwnd_quota;
+	int result;
 
 	/* If we are closed, the bytes will have to remain here.
 	 * In time closedown will finish, we empty the write queue and all
@@ -974,6 +1368,14 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
 		return 0;
 
 	sent_pkts = 0;
+
+	/* Do MTU probing. */
+	if ((result = tcp_mtu_probe(sk)) == 0) {
+		return 0;
+	} else if (result > 0) {
+		sent_pkts = 1;
+	}
+
 	while ((skb = sk->sk_send_head)) {
 		unsigned int limit;
 
@@ -1016,7 +1418,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
 
 		TCP_SKB_CB(skb)->when = tcp_time_stamp;
 
-		if (unlikely(tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC))))
+		if (unlikely(tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC)))
 			break;
 
 		/* Advance the send_head.  This one is sent out.
@@ -1089,7 +1491,7 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
 		/* Send it out now. */
 		TCP_SKB_CB(skb)->when = tcp_time_stamp;
 
-		if (likely(!tcp_transmit_skb(sk, skb_clone(skb, sk->sk_allocation)))) {
+		if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) {
 			update_send_head(sk, tp, skb);
 			tcp_cwnd_validate(sk, tp);
 			return;
@@ -1099,7 +1501,7 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
 
 /* This function returns the amount that we can raise the
  * usable window based on the following constraints
- *  
+ *
  * 1. The window can never be shrunk once it is offered (RFC 793)
  * 2. We limit memory per socket
  *
@@ -1118,12 +1520,12 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
  * side SWS prevention criteria. The problem is that under this rule
  * a stream of single byte packets will cause the right side of the
  * window to always advance by a single byte.
- * 
+ *
  * Of course, if the sender implements sender side SWS prevention
  * then this will not be a problem.
- * 
+ *
  * BSD seems to make the following compromise:
- * 
+ *
  *	If the free space is less than the 1/4 of the maximum
  *	space available and the free space is less than 1/2 mss,
  *	then set the window to 0.
@@ -1151,23 +1553,24 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
  */
 u32 __tcp_select_window(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
-	/* MSS for the peer's data.  Previous verions used mss_clamp
+	/* MSS for the peer's data.  Previous versions used mss_clamp
 	 * here.  I don't know if the value based on our guesses
 	 * of peer's MSS is better for the performance.  It's more correct
 	 * but may be worse for the performance because of rcv_mss
 	 * fluctuations.  --SAW  1998/11/1
 	 */
-	int mss = tp->ack.rcv_mss;
+	int mss = icsk->icsk_ack.rcv_mss;
 	int free_space = tcp_space(sk);
 	int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk));
 	int window;
 
 	if (mss > full_space)
-		mss = full_space; 
+		mss = full_space;
 
 	if (free_space < full_space/2) {
-		tp->ack.quick = 0;
+		icsk->icsk_ack.quick = 0;
 
 		if (tcp_memory_pressure)
 			tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U*tp->advmss);
@@ -1241,15 +1644,18 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
 		BUG_ON(tcp_skb_pcount(skb) != 1 ||
 		       tcp_skb_pcount(next_skb) != 1);
 
-		/* Ok.  We will be able to collapse the packet. */
-		__skb_unlink(next_skb, next_skb->list);
+		/* changing transmit queue under us so clear hints */
+		clear_all_retrans_hints(tp);
+
+		/* Ok.	We will be able to collapse the packet. */
+		__skb_unlink(next_skb, &sk->sk_write_queue);
 
 		memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
 
-		if (next_skb->ip_summed == CHECKSUM_HW)
-			skb->ip_summed = CHECKSUM_HW;
+		if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+			skb->ip_summed = CHECKSUM_PARTIAL;
 
-		if (skb->ip_summed != CHECKSUM_HW)
+		if (skb->ip_summed != CHECKSUM_PARTIAL)
 			skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
 
 		/* Update sequence range on original skb. */
@@ -1285,18 +1691,19 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
 }
 
 /* Do a simple retransmit without using the backoff mechanisms in
- * tcp_timer. This is used for path mtu discovery. 
+ * tcp_timer. This is used for path mtu discovery.
  * The socket is already locked here.
- */ 
+ */
 void tcp_simple_retransmit(struct sock *sk)
 {
+	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
 	unsigned int mss = tcp_current_mss(sk, 0);
 	int lost = 0;
 
 	sk_stream_for_retrans_queue(skb, sk) {
-		if (skb->len > mss && 
+		if (skb->len > mss &&
 		    !(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED)) {
 			if (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) {
 				TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
@@ -1310,22 +1717,24 @@ void tcp_simple_retransmit(struct sock *sk)
 		}
 	}
 
+	clear_all_retrans_hints(tp);
+
 	if (!lost)
 		return;
 
 	tcp_sync_left_out(tp);
 
- 	/* Don't muck with the congestion window here.
+	/* Don't muck with the congestion window here.
 	 * Reason is that we do not increase amount of _data_
 	 * in network, but units changed and effective
 	 * cwnd/ssthresh really reduced now.
 	 */
-	if (tp->ca_state != TCP_CA_Loss) {
+	if (icsk->icsk_ca_state != TCP_CA_Loss) {
 		tp->high_seq = tp->snd_nxt;
-		tp->snd_ssthresh = tcp_current_ssthresh(tp);
+		tp->snd_ssthresh = tcp_current_ssthresh(sk);
 		tp->prior_ssthresh = 0;
 		tp->undo_marker = 0;
-		tcp_set_ca_state(tp, TCP_CA_Loss);
+		tcp_set_ca_state(sk, TCP_CA_Loss);
 	}
 	tcp_xmit_retransmit_queue(sk);
 }
@@ -1337,11 +1746,17 @@ void tcp_simple_retransmit(struct sock *sk)
 int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
- 	unsigned int cur_mss = tcp_current_mss(sk, 0);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	unsigned int cur_mss = tcp_current_mss(sk, 0);
 	int err;
 
+	/* Inconslusive MTU probe */
+	if (icsk->icsk_mtup.probe_size) {
+		icsk->icsk_mtup.probe_size = 0;
+	}
+
 	/* Do not sent more than we queued. 1/4 is reserved for possible
-	 * copying overhead: frgagmentation, tunneling, mangling etc.
+	 * copying overhead: fragmentation, tunneling, mangling etc.
 	 */
 	if (atomic_read(&sk->sk_wmem_alloc) >
 	    min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf))
@@ -1350,12 +1765,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	if (before(TCP_SKB_CB(skb)->seq, tp->snd_una)) {
 		if (before(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
 			BUG();
-
-		if (sk->sk_route_caps & NETIF_F_TSO) {
-			sk->sk_route_caps &= ~NETIF_F_TSO;
-			sock_set_flag(sk, SOCK_NO_LARGESEND);
-		}
-
 		if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq))
 			return -ENOMEM;
 	}
@@ -1370,22 +1779,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 		return -EAGAIN;
 
 	if (skb->len > cur_mss) {
-		int old_factor = tcp_skb_pcount(skb);
-		int diff;
-
 		if (tcp_fragment(sk, skb, cur_mss, cur_mss))
 			return -ENOMEM; /* We'll try again later. */
-
-		/* New SKB created, account for it. */
-		diff = old_factor - tcp_skb_pcount(skb) -
-		       tcp_skb_pcount(skb->next);
-		tp->packets_out -= diff;
-
-		if (diff > 0) {
-			tp->fackets_out -= diff;
-			if ((int)tp->fackets_out < 0)
-				tp->fackets_out = 0;
-		}
 	}
 
 	/* Collapse two adjacent packets if worthwhile and we can. */
@@ -1398,7 +1793,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	   (sysctl_tcp_retrans_collapse != 0))
 		tcp_retrans_try_collapse(sk, skb, cur_mss);
 
-	if(tp->af_specific->rebuild_header(sk))
+	if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
 		return -EHOSTUNREACH; /* Routing failure or similar. */
 
 	/* Some Solaris stacks overoptimize and ignore the FIN on a
@@ -1410,8 +1805,9 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	   tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
 		if (!pskb_trim(skb, 0)) {
 			TCP_SKB_CB(skb)->seq = TCP_SKB_CB(skb)->end_seq - 1;
-			skb_shinfo(skb)->tso_segs = 1;
-			skb_shinfo(skb)->tso_size = 0;
+			skb_shinfo(skb)->gso_segs = 1;
+			skb_shinfo(skb)->gso_size = 0;
+			skb_shinfo(skb)->gso_type = 0;
 			skb->ip_summed = CHECKSUM_NONE;
 			skb->csum = 0;
 		}
@@ -1422,9 +1818,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	 */
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
 
-	err = tcp_transmit_skb(sk, (skb_cloned(skb) ?
-				    pskb_copy(skb, GFP_ATOMIC):
-				    skb_clone(skb, GFP_ATOMIC)));
+	err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 
 	if (err == 0) {
 		/* Update global TCP statistics. */
@@ -1465,15 +1859,28 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
  */
 void tcp_xmit_retransmit_queue(struct sock *sk)
 {
+	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
-	int packet_cnt = tp->lost_out;
+	int packet_cnt;
+
+	if (tp->retransmit_skb_hint) {
+		skb = tp->retransmit_skb_hint;
+		packet_cnt = tp->retransmit_cnt_hint;
+	}else{
+		skb = sk->sk_write_queue.next;
+		packet_cnt = 0;
+	}
 
 	/* First pass: retransmit lost packets. */
-	if (packet_cnt) {
-		sk_stream_for_retrans_queue(skb, sk) {
+	if (tp->lost_out) {
+		sk_stream_for_retrans_queue_from(skb, sk) {
 			__u8 sacked = TCP_SKB_CB(skb)->sacked;
 
+			/* we could do better than to assign each time */
+			tp->retransmit_skb_hint = skb;
+			tp->retransmit_cnt_hint = packet_cnt;
+
 			/* Assume this retransmit will generate
 			 * only one packet for congestion window
 			 * calculation purposes.  This works because
@@ -1484,22 +1891,26 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 			if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
 				return;
 
-			if (sacked&TCPCB_LOST) {
+			if (sacked & TCPCB_LOST) {
 				if (!(sacked&(TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
-					if (tcp_retransmit_skb(sk, skb))
+					if (tcp_retransmit_skb(sk, skb)) {
+						tp->retransmit_skb_hint = NULL;
 						return;
-					if (tp->ca_state != TCP_CA_Loss)
+					}
+					if (icsk->icsk_ca_state != TCP_CA_Loss)
 						NET_INC_STATS_BH(LINUX_MIB_TCPFASTRETRANS);
 					else
 						NET_INC_STATS_BH(LINUX_MIB_TCPSLOWSTARTRETRANS);
 
 					if (skb ==
 					    skb_peek(&sk->sk_write_queue))
-						tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+						inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+									  inet_csk(sk)->icsk_rto,
+									  TCP_RTO_MAX);
 				}
 
-				packet_cnt -= tcp_skb_pcount(skb);
-				if (packet_cnt <= 0)
+				packet_cnt += tcp_skb_pcount(skb);
+				if (packet_cnt >= tp->lost_out)
 					break;
 			}
 		}
@@ -1508,7 +1919,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 	/* OK, demanded retransmission is finished. */
 
 	/* Forward retransmissions are possible only during Recovery. */
-	if (tp->ca_state != TCP_CA_Recovery)
+	if (icsk->icsk_ca_state != TCP_CA_Recovery)
 		return;
 
 	/* No forward retransmissions in Reno are possible. */
@@ -1525,9 +1936,18 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 	if (tcp_may_send_now(sk, tp))
 		return;
 
-	packet_cnt = 0;
+	if (tp->forward_skb_hint) {
+		skb = tp->forward_skb_hint;
+		packet_cnt = tp->forward_cnt_hint;
+	} else{
+		skb = sk->sk_write_queue.next;
+		packet_cnt = 0;
+	}
+
+	sk_stream_for_retrans_queue_from(skb, sk) {
+		tp->forward_cnt_hint = packet_cnt;
+		tp->forward_skb_hint = skb;
 
-	sk_stream_for_retrans_queue(skb, sk) {
 		/* Similar to the retransmit loop above we
 		 * can pretend that the retransmitted SKB
 		 * we send out here will be composed of one
@@ -1544,11 +1964,15 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 			continue;
 
 		/* Ok, retransmit it. */
-		if (tcp_retransmit_skb(sk, skb))
+		if (tcp_retransmit_skb(sk, skb)) {
+			tp->forward_skb_hint = NULL;
 			break;
+		}
 
 		if (skb == skb_peek(&sk->sk_write_queue))
-			tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+						  inet_csk(sk)->icsk_rto,
+						  TCP_RTO_MAX);
 
 		NET_INC_STATS_BH(LINUX_MIB_TCPFORWARDRETRANS);
 	}
@@ -1560,10 +1984,10 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
  */
 void tcp_send_fin(struct sock *sk)
 {
-	struct tcp_sock *tp = tcp_sk(sk);	
+	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb = skb_peek_tail(&sk->sk_write_queue);
 	int mss_now;
-	
+
 	/* Optimization, tack on the FIN if we have a queue of
 	 * unsent frames.  But be careful about outgoing SACKS
 	 * and IP options.
@@ -1577,7 +2001,7 @@ void tcp_send_fin(struct sock *sk)
 	} else {
 		/* Socket is locked, keep trying until memory is available. */
 		for (;;) {
-			skb = alloc_skb(MAX_TCP_HEADER, GFP_KERNEL);
+			skb = alloc_skb_fclone(MAX_TCP_HEADER, GFP_KERNEL);
 			if (skb)
 				break;
 			yield();
@@ -1588,8 +2012,9 @@ void tcp_send_fin(struct sock *sk)
 		skb->csum = 0;
 		TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
 		TCP_SKB_CB(skb)->sacked = 0;
-		skb_shinfo(skb)->tso_segs = 1;
-		skb_shinfo(skb)->tso_size = 0;
+		skb_shinfo(skb)->gso_segs = 1;
+		skb_shinfo(skb)->gso_size = 0;
+		skb_shinfo(skb)->gso_type = 0;
 
 		/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
 		TCP_SKB_CB(skb)->seq = tp->write_seq;
@@ -1604,7 +2029,7 @@ void tcp_send_fin(struct sock *sk)
  * was unread data in the receive queue.  This behavior is recommended
  * by draft-ietf-tcpimpl-prob-03.txt section 3.10.  -DaveM
  */
-void tcp_send_active_reset(struct sock *sk, unsigned int __nocast priority)
+void tcp_send_active_reset(struct sock *sk, gfp_t priority)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
@@ -1621,14 +2046,15 @@ void tcp_send_active_reset(struct sock *sk, unsigned int __nocast priority)
 	skb->csum = 0;
 	TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
 	TCP_SKB_CB(skb)->sacked = 0;
-	skb_shinfo(skb)->tso_segs = 1;
-	skb_shinfo(skb)->tso_size = 0;
+	skb_shinfo(skb)->gso_segs = 1;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_type = 0;
 
 	/* Send it off. */
 	TCP_SKB_CB(skb)->seq = tcp_acceptable_seq(sk, tp);
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq;
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
-	if (tcp_transmit_skb(sk, skb))
+	if (tcp_transmit_skb(sk, skb, 0, priority))
 		NET_INC_STATS(LINUX_MIB_TCPABORTFAILED);
 }
 
@@ -1663,7 +2089,7 @@ int tcp_send_synack(struct sock *sk)
 		TCP_ECN_send_synack(tcp_sk(sk), skb);
 	}
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
-	return tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC));
+	return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 }
 
 /*
@@ -1677,6 +2103,10 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	struct tcphdr *th;
 	int tcp_header_size;
 	struct sk_buff *skb;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *md5;
+	__u8 *md5_hash_location;
+#endif
 
 	skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
 	if (skb == NULL)
@@ -1692,56 +2122,80 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 			   (ireq->wscale_ok ? TCPOLEN_WSCALE_ALIGNED : 0) +
 			   /* SACK_PERM is in the place of NOP NOP of TS */
 			   ((ireq->sack_ok && !ireq->tstamp_ok) ? TCPOLEN_SACKPERM_ALIGNED : 0));
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Are we doing MD5 on this segment? If so - make room for it */
+	md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
+	if (md5)
+		tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
 	skb->h.th = th = (struct tcphdr *) skb_push(skb, tcp_header_size);
 
 	memset(th, 0, sizeof(struct tcphdr));
 	th->syn = 1;
 	th->ack = 1;
-	if (dst->dev->features&NETIF_F_TSO)
-		ireq->ecn_ok = 0;
 	TCP_ECN_make_synack(req, th);
 	th->source = inet_sk(sk)->sport;
 	th->dest = ireq->rmt_port;
 	TCP_SKB_CB(skb)->seq = tcp_rsk(req)->snt_isn;
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
 	TCP_SKB_CB(skb)->sacked = 0;
-	skb_shinfo(skb)->tso_segs = 1;
-	skb_shinfo(skb)->tso_size = 0;
+	skb_shinfo(skb)->gso_segs = 1;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_type = 0;
 	th->seq = htonl(TCP_SKB_CB(skb)->seq);
 	th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
 	if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
-		__u8 rcv_wscale; 
+		__u8 rcv_wscale;
 		/* Set this up on the first call only */
 		req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
 		/* tcp_full_space because it is guaranteed to be the first packet */
-		tcp_select_initial_window(tcp_full_space(sk), 
+		tcp_select_initial_window(tcp_full_space(sk),
 			dst_metric(dst, RTAX_ADVMSS) - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
 			&req->rcv_wnd,
 			&req->window_clamp,
 			ireq->wscale_ok,
 			&rcv_wscale);
-		ireq->rcv_wscale = rcv_wscale; 
+		ireq->rcv_wscale = rcv_wscale;
 	}
 
 	/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
 	th->window = htons(req->rcv_wnd);
 
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
-	tcp_syn_build_options((__u32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
+	tcp_syn_build_options((__be32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
 			      ireq->sack_ok, ireq->wscale_ok, ireq->rcv_wscale,
 			      TCP_SKB_CB(skb)->when,
-			      req->ts_recent);
+			      req->ts_recent,
+			      (
+#ifdef CONFIG_TCP_MD5SIG
+			       md5 ? &md5_hash_location :
+#endif
+			       NULL)
+			      );
 
 	skb->csum = 0;
 	th->doff = (tcp_header_size >> 2);
 	TCP_INC_STATS(TCP_MIB_OUTSEGS);
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Okay, we have all we need - do the md5 hash if needed */
+	if (md5) {
+		tp->af_specific->calc_md5_hash(md5_hash_location,
+					       md5,
+					       NULL, dst, req,
+					       skb->h.th, sk->sk_protocol,
+					       skb->len);
+	}
+#endif
+
 	return skb;
 }
 
-/* 
+/*
  * Do all connect socket setups that can be done AF independent.
- */ 
-static inline void tcp_connect_init(struct sock *sk)
+ */
+static void tcp_connect_init(struct sock *sk)
 {
 	struct dst_entry *dst = __sk_dst_get(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -1753,10 +2207,16 @@ static inline void tcp_connect_init(struct sock *sk)
 	tp->tcp_header_len = sizeof(struct tcphdr) +
 		(sysctl_tcp_timestamps ? TCPOLEN_TSTAMP_ALIGNED : 0);
 
+#ifdef CONFIG_TCP_MD5SIG
+	if (tp->af_specific->md5_lookup(sk, sk) != NULL)
+		tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
 	/* If user gave his TCP_MAXSEG, record it to clamp */
 	if (tp->rx_opt.user_mss)
 		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
 	tp->max_window = 0;
+	tcp_mtup_init(sk);
 	tcp_sync_mss(sk, dst_mtu(dst));
 
 	if (!tp->window_clamp)
@@ -1784,14 +2244,14 @@ static inline void tcp_connect_init(struct sock *sk)
 	tp->rcv_wup = 0;
 	tp->copied_seq = 0;
 
-	tp->rto = TCP_TIMEOUT_INIT;
-	tp->retransmits = 0;
+	inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+	inet_csk(sk)->icsk_retransmits = 0;
 	tcp_clear_retrans(tp);
 }
 
 /*
  * Build a SYN and send it off.
- */ 
+ */
 int tcp_connect(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -1799,7 +2259,7 @@ int tcp_connect(struct sock *sk)
 
 	tcp_connect_init(sk);
 
-	buff = alloc_skb(MAX_TCP_HEADER + 15, sk->sk_allocation);
+	buff = alloc_skb_fclone(MAX_TCP_HEADER + 15, sk->sk_allocation);
 	if (unlikely(buff == NULL))
 		return -ENOBUFS;
 
@@ -1809,13 +2269,13 @@ int tcp_connect(struct sock *sk)
 	TCP_SKB_CB(buff)->flags = TCPCB_FLAG_SYN;
 	TCP_ECN_send_syn(sk, tp, buff);
 	TCP_SKB_CB(buff)->sacked = 0;
-	skb_shinfo(buff)->tso_segs = 1;
-	skb_shinfo(buff)->tso_size = 0;
+	skb_shinfo(buff)->gso_segs = 1;
+	skb_shinfo(buff)->gso_size = 0;
+	skb_shinfo(buff)->gso_type = 0;
 	buff->csum = 0;
+	tp->snd_nxt = tp->write_seq;
 	TCP_SKB_CB(buff)->seq = tp->write_seq++;
 	TCP_SKB_CB(buff)->end_seq = tp->write_seq;
-	tp->snd_nxt = tp->write_seq;
-	tp->pushed_seq = tp->write_seq;
 
 	/* Send it off. */
 	TCP_SKB_CB(buff)->when = tcp_time_stamp;
@@ -1824,11 +2284,18 @@ int tcp_connect(struct sock *sk)
 	__skb_queue_tail(&sk->sk_write_queue, buff);
 	sk_charge_skb(sk, buff);
 	tp->packets_out += tcp_skb_pcount(buff);
-	tcp_transmit_skb(sk, skb_clone(buff, GFP_KERNEL));
+	tcp_transmit_skb(sk, buff, 1, GFP_KERNEL);
+
+	/* We change tp->snd_nxt after the tcp_transmit_skb() call
+	 * in order to make this packet get counted in tcpOutSegs.
+	 */
+	tp->snd_nxt = tp->write_seq;
+	tp->pushed_seq = tp->write_seq;
 	TCP_INC_STATS(TCP_MIB_ACTIVEOPENS);
 
 	/* Timer for repeating the SYN until an answer. */
-	tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+				  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
 	return 0;
 }
 
@@ -1838,20 +2305,21 @@ int tcp_connect(struct sock *sk)
  */
 void tcp_send_delayed_ack(struct sock *sk)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
-	int ato = tp->ack.ato;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int ato = icsk->icsk_ack.ato;
 	unsigned long timeout;
 
 	if (ato > TCP_DELACK_MIN) {
+		const struct tcp_sock *tp = tcp_sk(sk);
 		int max_ato = HZ/2;
 
-		if (tp->ack.pingpong || (tp->ack.pending&TCP_ACK_PUSHED))
+		if (icsk->icsk_ack.pingpong || (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
 			max_ato = TCP_DELACK_MAX;
 
 		/* Slow path, intersegment interval is "high". */
 
 		/* If some rtt estimate is known, use it to bound delayed ack.
-		 * Do not use tp->rto here, use results of rtt measurements
+		 * Do not use inet_csk(sk)->icsk_rto here, use results of rtt measurements
 		 * directly.
 		 */
 		if (tp->srtt) {
@@ -1868,21 +2336,22 @@ void tcp_send_delayed_ack(struct sock *sk)
 	timeout = jiffies + ato;
 
 	/* Use new timeout only if there wasn't a older one earlier. */
-	if (tp->ack.pending&TCP_ACK_TIMER) {
+	if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
 		/* If delack timer was blocked or is about to expire,
 		 * send ACK now.
 		 */
-		if (tp->ack.blocked || time_before_eq(tp->ack.timeout, jiffies+(ato>>2))) {
+		if (icsk->icsk_ack.blocked ||
+		    time_before_eq(icsk->icsk_ack.timeout, jiffies + (ato >> 2))) {
 			tcp_send_ack(sk);
 			return;
 		}
 
-		if (!time_before(timeout, tp->ack.timeout))
-			timeout = tp->ack.timeout;
+		if (!time_before(timeout, icsk->icsk_ack.timeout))
+			timeout = icsk->icsk_ack.timeout;
 	}
-	tp->ack.pending |= TCP_ACK_SCHED|TCP_ACK_TIMER;
-	tp->ack.timeout = timeout;
-	sk_reset_timer(sk, &tp->delack_timer, timeout);
+	icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
+	icsk->icsk_ack.timeout = timeout;
+	sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 
 /* This routine sends an ack and also updates the window. */
@@ -1899,9 +2368,10 @@ void tcp_send_ack(struct sock *sk)
 		 */
 		buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
 		if (buff == NULL) {
-			tcp_schedule_ack(tp);
-			tp->ack.ato = TCP_ATO_MIN;
-			tcp_reset_xmit_timer(sk, TCP_TIME_DACK, TCP_DELACK_MAX);
+			inet_csk_schedule_ack(sk);
+			inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+						  TCP_DELACK_MAX, TCP_RTO_MAX);
 			return;
 		}
 
@@ -1910,13 +2380,14 @@ void tcp_send_ack(struct sock *sk)
 		buff->csum = 0;
 		TCP_SKB_CB(buff)->flags = TCPCB_FLAG_ACK;
 		TCP_SKB_CB(buff)->sacked = 0;
-		skb_shinfo(buff)->tso_segs = 1;
-		skb_shinfo(buff)->tso_size = 0;
+		skb_shinfo(buff)->gso_segs = 1;
+		skb_shinfo(buff)->gso_size = 0;
+		skb_shinfo(buff)->gso_type = 0;
 
 		/* Send it off, this clears delayed acks for us. */
 		TCP_SKB_CB(buff)->seq = TCP_SKB_CB(buff)->end_seq = tcp_acceptable_seq(sk, tp);
 		TCP_SKB_CB(buff)->when = tcp_time_stamp;
-		tcp_transmit_skb(sk, buff);
+		tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
 	}
 }
 
@@ -1938,7 +2409,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 
 	/* We don't queue it, tcp_transmit_skb() sets ownership. */
 	skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
-	if (skb == NULL) 
+	if (skb == NULL)
 		return -1;
 
 	/* Reserve space for headers and set control bits. */
@@ -1946,8 +2417,9 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	skb->csum = 0;
 	TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
 	TCP_SKB_CB(skb)->sacked = urgent;
-	skb_shinfo(skb)->tso_segs = 1;
-	skb_shinfo(skb)->tso_size = 0;
+	skb_shinfo(skb)->gso_segs = 1;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_type = 0;
 
 	/* Use a previous sequence.  This should cause the other
 	 * end to send an ack.  Don't queue or clone SKB, just
@@ -1956,7 +2428,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	TCP_SKB_CB(skb)->seq = urgent ? tp->snd_una : tp->snd_una - 1;
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq;
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
-	return tcp_transmit_skb(sk, skb);
+	return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
 }
 
 int tcp_write_wakeup(struct sock *sk)
@@ -1984,18 +2456,12 @@ int tcp_write_wakeup(struct sock *sk)
 				TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
 				if (tcp_fragment(sk, skb, seg_size, mss))
 					return -1;
-				/* SWS override triggered forced fragmentation.
-				 * Disable TSO, the connection is too sick. */
-				if (sk->sk_route_caps & NETIF_F_TSO) {
-					sock_set_flag(sk, SOCK_NO_LARGESEND);
-					sk->sk_route_caps &= ~NETIF_F_TSO;
-				}
 			} 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)->when = tcp_time_stamp;
-			err = tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC));
+			err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 			if (!err) {
 				update_send_head(sk, tp, skb);
 			}
@@ -2015,6 +2481,7 @@ int tcp_write_wakeup(struct sock *sk)
  */
 void tcp_send_probe0(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	int err;
 
@@ -2022,28 +2489,31 @@ void tcp_send_probe0(struct sock *sk)
 
 	if (tp->packets_out || !sk->sk_send_head) {
 		/* Cancel probe timer, if it is not required. */
-		tp->probes_out = 0;
-		tp->backoff = 0;
+		icsk->icsk_probes_out = 0;
+		icsk->icsk_backoff = 0;
 		return;
 	}
 
 	if (err <= 0) {
-		if (tp->backoff < sysctl_tcp_retries2)
-			tp->backoff++;
-		tp->probes_out++;
-		tcp_reset_xmit_timer (sk, TCP_TIME_PROBE0, 
-				      min(tp->rto << tp->backoff, TCP_RTO_MAX));
+		if (icsk->icsk_backoff < sysctl_tcp_retries2)
+			icsk->icsk_backoff++;
+		icsk->icsk_probes_out++;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+					  min(icsk->icsk_rto << icsk->icsk_backoff, TCP_RTO_MAX),
+					  TCP_RTO_MAX);
 	} else {
 		/* If packet was not sent due to local congestion,
-		 * do not backoff and do not remember probes_out.
+		 * do not backoff and do not remember icsk_probes_out.
 		 * Let local senders to fight for local resources.
 		 *
 		 * Use accumulated backoff yet.
 		 */
-		if (!tp->probes_out)
-			tp->probes_out=1;
-		tcp_reset_xmit_timer (sk, TCP_TIME_PROBE0, 
-				      min(tp->rto << tp->backoff, TCP_RESOURCE_PROBE_INTERVAL));
+		if (!icsk->icsk_probes_out)
+			icsk->icsk_probes_out = 1;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+					  min(icsk->icsk_rto << icsk->icsk_backoff,
+					      TCP_RESOURCE_PROBE_INTERVAL),
+					  TCP_RTO_MAX);
 	}
 }
 
@@ -2051,3 +2521,5 @@ EXPORT_SYMBOL(tcp_connect);
 EXPORT_SYMBOL(tcp_make_synack);
 EXPORT_SYMBOL(tcp_simple_retransmit);
 EXPORT_SYMBOL(tcp_sync_mss);
+EXPORT_SYMBOL(sysctl_tcp_tso_win_divisor);
+EXPORT_SYMBOL(tcp_mtup_init);