1 files changed, 317 insertions, 357 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 324b4207254..ed750f9ceb0 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -61,27 +61,24 @@ 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 tcp_packets_out_inc(struct sock *sk,
-				       const struct sk_buff *skb)
+static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	int orig = tp->packets_out;
+	unsigned int prior_packets = tp->packets_out;
+
+	tcp_advance_send_head(sk, skb);
+	tp->snd_nxt = TCP_SKB_CB(skb)->end_seq;
+
+	/* Don't override Nagle indefinately with F-RTO */
+	if (tp->frto_counter == 2)
+		tp->frto_counter = 3;
 
 	tp->packets_out += tcp_skb_pcount(skb);
-	if (!orig)
+	if (!prior_packets)
 		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 					  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
 }
 
-static void update_send_head(struct sock *sk, struct sk_buff *skb)
-{
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	tcp_advance_send_head(sk, skb);
-	tp->snd_nxt = TCP_SKB_CB(skb)->end_seq;
-	tcp_packets_out_inc(sk, skb);
-}
-
 /* SND.NXT, if window was not shrunk.
  * If window has been shrunk, what should we make? It is not clear at all.
  * Using SND.UNA we will fail to open window, SND.NXT is out of window. :-(
@@ -92,10 +89,10 @@ static inline __u32 tcp_acceptable_seq(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	if (!before(tp->snd_una+tp->snd_wnd, tp->snd_nxt))
+	if (!before(tcp_wnd_end(tp), tp->snd_nxt))
 		return tp->snd_nxt;
 	else
-		return tp->snd_una+tp->snd_wnd;
+		return tcp_wnd_end(tp);
 }
 
 /* Calculate mss to advertise in SYN segment.
@@ -224,14 +221,14 @@ void tcp_select_initial_window(int __space, __u32 mss,
 	 * following RFC2414. Senders, not following this RFC,
 	 * will be satisfied with 2.
 	 */
-	if (mss > (1<<*rcv_wscale)) {
+	if (mss > (1 << *rcv_wscale)) {
 		int init_cwnd = 4;
-		if (mss > 1460*3)
+		if (mss > 1460 * 3)
 			init_cwnd = 2;
 		else if (mss > 1460)
 			init_cwnd = 3;
-		if (*rcv_wnd > init_cwnd*mss)
-			*rcv_wnd = init_cwnd*mss;
+		if (*rcv_wnd > init_cwnd * mss)
+			*rcv_wnd = init_cwnd * mss;
 	}
 
 	/* Set the clamp no higher than max representable value */
@@ -281,11 +278,10 @@ static u16 tcp_select_window(struct sock *sk)
 	return new_win;
 }
 
-static inline void TCP_ECN_send_synack(struct tcp_sock *tp,
-				       struct sk_buff *skb)
+static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
 {
 	TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
-	if (!(tp->ecn_flags&TCP_ECN_OK))
+	if (!(tp->ecn_flags & TCP_ECN_OK))
 		TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
 }
 
@@ -295,7 +291,7 @@ static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
 
 	tp->ecn_flags = 0;
 	if (sysctl_tcp_ecn) {
-		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR;
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR;
 		tp->ecn_flags = TCP_ECN_OK;
 	}
 }
@@ -317,7 +313,7 @@ static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
 		if (skb->len != tcp_header_len &&
 		    !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
 			INET_ECN_xmit(sk);
-			if (tp->ecn_flags&TCP_ECN_QUEUE_CWR) {
+			if (tp->ecn_flags & TCP_ECN_QUEUE_CWR) {
 				tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
 				tcp_hdr(skb)->cwr = 1;
 				skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
@@ -331,6 +327,26 @@ static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
 	}
 }
 
+/* Constructs common control bits of non-data skb. If SYN/FIN is present,
+ * auto increment end seqno.
+ */
+static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
+{
+	skb->csum = 0;
+
+	TCP_SKB_CB(skb)->flags = flags;
+	TCP_SKB_CB(skb)->sacked = 0;
+
+	skb_shinfo(skb)->gso_segs = 1;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_type = 0;
+
+	TCP_SKB_CB(skb)->seq = seq;
+	if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN))
+		seq++;
+	TCP_SKB_CB(skb)->end_seq = seq;
+}
+
 static void tcp_build_and_update_options(__be32 *ptr, struct tcp_sock *tp,
 					 __u32 tstamp, __u8 **md5_hash)
 {
@@ -434,7 +450,7 @@ static void tcp_syn_build_options(__be32 *ptr, int mss, int ts, int sack,
 			       (TCPOPT_NOP << 16) |
 			       (TCPOPT_MD5SIG << 8) |
 			       TCPOLEN_MD5SIG);
-		*md5_hash = (__u8 *) ptr;
+		*md5_hash = (__u8 *)ptr;
 	}
 #endif
 }
@@ -450,7 +466,8 @@ static void tcp_syn_build_options(__be32 *ptr, int mss, int ts, int sack,
  * 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, int clone_it, gfp_t gfp_mask)
+static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
+			    gfp_t gfp_mask)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct inet_sock *inet;
@@ -554,8 +571,8 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	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);
+		     between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
+		th->urg_ptr		= htons(tp->snd_up - tcb->seq);
 		th->urg			= 1;
 	}
 
@@ -619,7 +636,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 #undef SYSCTL_FLAG_SACK
 }
 
-
 /* This routine just queue's the buffer
  *
  * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames,
@@ -633,10 +649,12 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
 	tp->write_seq = TCP_SKB_CB(skb)->end_seq;
 	skb_header_release(skb);
 	tcp_add_write_queue_tail(sk, skb);
-	sk_charge_skb(sk, skb);
+	sk->sk_wmem_queued += skb->truesize;
+	sk_mem_charge(sk, skb->truesize);
 }
 
-static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
+static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb,
+				 unsigned int mss_now)
 {
 	if (skb->len <= mss_now || !sk_can_gso(sk)) {
 		/* Avoid the costly divide in the normal
@@ -653,23 +671,18 @@ static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned
 }
 
 /* When a modification to fackets out becomes necessary, we need to check
- * skb is counted to fackets_out or not. Another important thing is to
- * tweak SACK fastpath hint too as it would overwrite all changes unless
- * hint is also changed.
+ * skb is counted to fackets_out or not.
  */
-static void tcp_adjust_fackets_out(struct tcp_sock *tp, struct sk_buff *skb,
+static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb,
 				   int decr)
 {
+	struct tcp_sock *tp = tcp_sk(sk);
+
 	if (!tp->sacked_out || tcp_is_reno(tp))
 		return;
 
-	if (!before(tp->highest_sack, TCP_SKB_CB(skb)->seq))
+	if (after(tcp_highest_sack_seq(tp), TCP_SKB_CB(skb)->seq))
 		tp->fackets_out -= decr;
-
-	/* cnt_hint is "off-by-one" compared with fackets_out (see sacktag) */
-	if (tp->fastpath_skb_hint != NULL &&
-	    after(TCP_SKB_CB(tp->fastpath_skb_hint)->seq, TCP_SKB_CB(skb)->seq))
-		tp->fastpath_cnt_hint -= decr;
 }
 
 /* Function to create two new TCP segments.  Shrinks the given segment
@@ -677,7 +690,8 @@ static void tcp_adjust_fackets_out(struct tcp_sock *tp, struct sk_buff *skb,
  * packet to the list.  This won't be called frequently, I hope.
  * Remember, these are still headerless SKBs at this point.
  */
-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;
@@ -702,7 +716,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 	if (buff == NULL)
 		return -ENOMEM; /* We'll just try again later. */
 
-	sk_charge_skb(sk, buff);
+	sk->sk_wmem_queued += buff->truesize;
+	sk_mem_charge(sk, buff->truesize);
 	nlen = skb->len - len - nsize;
 	buff->truesize += nlen;
 	skb->truesize -= nlen;
@@ -712,20 +727,16 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 	TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq;
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
 
-	if (tcp_is_sack(tp) && tp->sacked_out &&
-	    (TCP_SKB_CB(skb)->seq == tp->highest_sack))
-		tp->highest_sack = TCP_SKB_CB(buff)->seq;
-
 	/* 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 & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
 	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_PARTIAL) {
 		/* Copy and checksum data tail into the new buffer. */
-		buff->csum = csum_partial_copy_nocheck(skb->data + len, skb_put(buff, nsize),
+		buff->csum = csum_partial_copy_nocheck(skb->data + len,
+						       skb_put(buff, nsize),
 						       nsize, 0);
 
 		skb_trim(skb, len);
@@ -772,7 +783,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
 			tcp_dec_pcount_approx_int(&tp->sacked_out, diff);
 			tcp_verify_left_out(tp);
 		}
-		tcp_adjust_fackets_out(tp, skb, diff);
+		tcp_adjust_fackets_out(sk, skb, diff);
 	}
 
 	/* Link BUFF into the send queue. */
@@ -792,7 +803,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
 
 	eat = len;
 	k = 0;
-	for (i=0; i<skb_shinfo(skb)->nr_frags; i++) {
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 		if (skb_shinfo(skb)->frags[i].size <= eat) {
 			put_page(skb_shinfo(skb)->frags[i].page);
 			eat -= skb_shinfo(skb)->frags[i].size;
@@ -815,8 +826,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
 
 int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 {
-	if (skb_cloned(skb) &&
-	    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+	if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
 		return -ENOMEM;
 
 	/* If len == headlen, we avoid __skb_pull to preserve alignment. */
@@ -830,7 +840,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 
 	skb->truesize	     -= len;
 	sk->sk_wmem_queued   -= len;
-	sk->sk_forward_alloc += len;
+	sk_mem_uncharge(sk, len);
 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
 
 	/* Any change of skb->len requires recalculation of tso
@@ -898,6 +908,15 @@ 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
@@ -920,7 +939,6 @@ void tcp_mtup_init(struct sock *sk)
    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);
@@ -931,10 +949,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 		icsk->icsk_mtup.search_high = pmtu;
 
 	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);
+	mss_now = tcp_bound_to_half_wnd(tp, mss_now);
 
 	/* And store cached results */
 	icsk->icsk_pmtu_cookie = pmtu;
@@ -988,11 +1003,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 				  inet_csk(sk)->icsk_ext_hdr_len -
 				  tp->tcp_header_len);
 
-		if (tp->max_window &&
-		    (xmit_size_goal > (tp->max_window >> 1)))
-			xmit_size_goal = max((tp->max_window >> 1),
-					     68U - 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;
@@ -1001,13 +1012,11 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 }
 
 /* Congestion window validation. (RFC2861) */
-
 static void tcp_cwnd_validate(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	__u32 packets_out = tp->packets_out;
 
-	if (packets_out >= tp->snd_cwnd) {
+	if (tp->packets_out >= tp->snd_cwnd) {
 		/* Network is feed fully. */
 		tp->snd_cwnd_used = 0;
 		tp->snd_cwnd_stamp = tcp_time_stamp;
@@ -1022,19 +1031,35 @@ static void tcp_cwnd_validate(struct sock *sk)
 	}
 }
 
-static unsigned int tcp_window_allows(struct tcp_sock *tp, struct sk_buff *skb, unsigned int mss_now, unsigned int cwnd)
+/* Returns the portion of skb which can be sent right away without
+ * introducing MSS oddities to segment boundaries. In rare cases where
+ * mss_now != mss_cache, we will request caller to create a small skb
+ * per input skb which could be mostly avoided here (if desired).
+ */
+static unsigned int tcp_mss_split_point(struct sock *sk, struct sk_buff *skb,
+					unsigned int mss_now, unsigned int cwnd)
 {
-	u32 window, cwnd_len;
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 needed, window, cwnd_len;
 
-	window = (tp->snd_una + tp->snd_wnd - TCP_SKB_CB(skb)->seq);
+	window = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
 	cwnd_len = mss_now * cwnd;
-	return min(window, cwnd_len);
+
+	if (likely(cwnd_len <= window && skb != tcp_write_queue_tail(sk)))
+		return cwnd_len;
+
+	if (skb == tcp_write_queue_tail(sk) && cwnd_len <= skb->len)
+		return cwnd_len;
+
+	needed = min(skb->len, window);
+	return needed - needed % mss_now;
 }
 
 /* Can at least one segment of SKB be sent right now, according to the
  * congestion window rules?  If so, return how many segments are allowed.
  */
-static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, struct sk_buff *skb)
+static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
+					 struct sk_buff *skb)
 {
 	u32 in_flight, cwnd;
 
@@ -1054,13 +1079,12 @@ 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 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 &&
-	     tcp_skb_mss(skb) != mss_now)) {
+	if (!tso_segs || (tso_segs > 1 && tcp_skb_mss(skb) != mss_now)) {
 		tcp_set_skb_tso_segs(sk, skb, mss_now);
 		tso_segs = tcp_skb_pcount(skb);
 	}
@@ -1080,16 +1104,13 @@ static inline int tcp_minshall_check(const struct tcp_sock *tp)
  * 4. Or TCP_CORK is not set, and all sent packets are ACKed.
  *    With Minshall's modification: all sent small packets are ACKed.
  */
-
 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 &&
-		((nonagle&TCP_NAGLE_CORK) ||
-		 (!nonagle &&
-		  tp->packets_out &&
-		  tcp_minshall_check(tp))));
+		((nonagle & TCP_NAGLE_CORK) ||
+		 (!nonagle && tp->packets_out && tcp_minshall_check(tp))));
 }
 
 /* Return non-zero if the Nagle test allows this packet to be
@@ -1121,14 +1142,15 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
 }
 
 /* Does at least the first segment of SKB fit into the send window? */
-static inline int tcp_snd_wnd_test(struct tcp_sock *tp, struct sk_buff *skb, unsigned int cur_mss)
+static inline int tcp_snd_wnd_test(struct tcp_sock *tp, struct sk_buff *skb,
+				   unsigned int cur_mss)
 {
 	u32 end_seq = TCP_SKB_CB(skb)->end_seq;
 
 	if (skb->len > cur_mss)
 		end_seq = TCP_SKB_CB(skb)->seq + cur_mss;
 
-	return !after(end_seq, tp->snd_una + tp->snd_wnd);
+	return !after(end_seq, tcp_wnd_end(tp));
 }
 
 /* This checks if the data bearing packet SKB (usually tcp_send_head(sk))
@@ -1147,8 +1169,7 @@ static unsigned int tcp_snd_test(struct sock *sk, struct sk_buff *skb,
 		return 0;
 
 	cwnd_quota = tcp_cwnd_test(tp, skb);
-	if (cwnd_quota &&
-	    !tcp_snd_wnd_test(tp, skb, cur_mss))
+	if (cwnd_quota && !tcp_snd_wnd_test(tp, skb, cur_mss))
 		cwnd_quota = 0;
 
 	return cwnd_quota;
@@ -1162,8 +1183,7 @@ int tcp_may_send_now(struct sock *sk)
 	return (skb &&
 		tcp_snd_test(sk, skb, tcp_current_mss(sk, 1),
 			     (tcp_skb_is_last(sk, skb) ?
-			      TCP_NAGLE_PUSH :
-			      tp->nonagle)));
+			      tp->nonagle : TCP_NAGLE_PUSH)));
 }
 
 /* Trim TSO SKB to LEN bytes, put the remaining data into a new packet
@@ -1173,7 +1193,8 @@ int tcp_may_send_now(struct sock *sk)
  * know that all the data is in scatter-gather pages, and that the
  * 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)
+static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
+			unsigned int mss_now)
 {
 	struct sk_buff *buff;
 	int nlen = skb->len - len;
@@ -1183,11 +1204,12 @@ 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_pskb(sk, 0, 0, GFP_ATOMIC);
+	buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC);
 	if (unlikely(buff == NULL))
 		return -ENOMEM;
 
-	sk_charge_skb(sk, buff);
+	sk->sk_wmem_queued += buff->truesize;
+	sk_mem_charge(sk, buff->truesize);
 	buff->truesize += nlen;
 	skb->truesize -= nlen;
 
@@ -1198,7 +1220,7 @@ 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 & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
 	TCP_SKB_CB(buff)->flags = flags;
 
 	/* This packet was never sent out yet, so no SACK bits. */
@@ -1236,15 +1258,15 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 		goto send_now;
 
 	/* Defer for less than two clock ticks. */
-	if (!tp->tso_deferred && ((jiffies<<1)>>1) - (tp->tso_deferred>>1) > 1)
+	if (tp->tso_deferred &&
+	    ((jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1)
 		goto send_now;
 
 	in_flight = tcp_packets_in_flight(tp);
 
-	BUG_ON(tcp_skb_pcount(skb) <= 1 ||
-	       (tp->snd_cwnd <= in_flight));
+	BUG_ON(tcp_skb_pcount(skb) <= 1 || (tp->snd_cwnd <= in_flight));
 
-	send_win = (tp->snd_una + tp->snd_wnd) - TCP_SKB_CB(skb)->seq;
+	send_win = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
 
 	/* From in_flight test above, we know that cwnd > in_flight.  */
 	cong_win = (tp->snd_cwnd - in_flight) * tp->mss_cache;
@@ -1275,7 +1297,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 	}
 
 	/* Ok, it looks like it is advisable to defer.  */
-	tp->tso_deferred = 1 | (jiffies<<1);
+	tp->tso_deferred = 1 | (jiffies << 1);
 
 	return 1;
 
@@ -1287,7 +1309,8 @@ send_now:
 /* 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 */
+ *         -1 otherwise
+ */
 static int tcp_mtu_probe(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -1295,7 +1318,7 @@ static int tcp_mtu_probe(struct sock *sk)
 	struct sk_buff *skb, *nskb, *next;
 	int len;
 	int probe_size;
-	unsigned int pif;
+	int size_needed;
 	int copy;
 	int mss_now;
 
@@ -1312,34 +1335,25 @@ static int tcp_mtu_probe(struct sock *sk)
 
 	/* Very simple search strategy: just double the MSS. */
 	mss_now = tcp_current_mss(sk, 0);
-	probe_size = 2*tp->mss_cache;
+	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)) {
 		/* TODO: set timer for probe_converge_event */
 		return -1;
 	}
 
 	/* Have enough data in the send queue to probe? */
-	len = 0;
-	if ((skb = tcp_send_head(sk)) == NULL)
-		return -1;
-	while ((len += skb->len) < probe_size && !tcp_skb_is_last(sk, skb))
-		skb = tcp_write_queue_next(sk, skb);
-	if (len < probe_size)
+	if (tp->write_seq - tp->snd_nxt < size_needed)
 		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;
-	}
+	if (tp->snd_wnd < size_needed)
+		return -1;
+	if (after(tp->snd_nxt + size_needed, tcp_wnd_end(tp)))
+		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)
+	/* Do we need to wait to drain cwnd? With none in flight, don't stall */
+	if (tcp_packets_in_flight(tp) + 2 > tp->snd_cwnd) {
+		if (!tcp_packets_in_flight(tp))
 			return -1;
 		else
 			return 0;
@@ -1348,11 +1362,10 @@ static int tcp_mtu_probe(struct sock *sk)
 	/* 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);
+	sk->sk_wmem_queued += nskb->truesize;
+	sk_mem_charge(sk, nskb->truesize);
 
 	skb = tcp_send_head(sk);
-	tcp_insert_write_queue_before(nskb, skb, sk);
-	tcp_advance_send_head(sk, skb);
 
 	TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
 	TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
@@ -1361,30 +1374,32 @@ static int tcp_mtu_probe(struct sock *sk)
 	nskb->csum = 0;
 	nskb->ip_summed = skb->ip_summed;
 
-	len = 0;
-	while (len < probe_size) {
-		next = tcp_write_queue_next(sk, skb);
+	tcp_insert_write_queue_before(nskb, skb, sk);
 
+	len = 0;
+	tcp_for_write_queue_from_safe(skb, next, sk) {
 		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);
+							    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;
 			tcp_unlink_write_queue(skb, sk);
-			sk_stream_free_skb(sk, skb);
+			sk_wmem_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);
+					skb->csum = csum_partial(skb->data,
+								 skb->len, 0);
 			} else {
 				__pskb_trim_head(skb, copy);
 				tcp_set_skb_tso_segs(sk, skb, mss_now);
@@ -1393,7 +1408,9 @@ static int tcp_mtu_probe(struct sock *sk)
 		}
 
 		len += copy;
-		skb = next;
+
+		if (len >= probe_size)
+			break;
 	}
 	tcp_init_tso_segs(sk, nskb, nskb->len);
 
@@ -1402,9 +1419,9 @@ static int tcp_mtu_probe(struct sock *sk)
 	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. */
+		 * effectively two packets. */
 		tp->snd_cwnd--;
-		update_send_head(sk, nskb);
+		tcp_event_new_data_sent(sk, nskb);
 
 		icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
 		tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
@@ -1416,7 +1433,6 @@ static int tcp_mtu_probe(struct sock *sk)
 	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.
@@ -1472,17 +1488,9 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
 		}
 
 		limit = mss_now;
-		if (tso_segs > 1) {
-			limit = tcp_window_allows(tp, skb,
-						  mss_now, cwnd_quota);
-
-			if (skb->len < limit) {
-				unsigned int trim = skb->len % mss_now;
-
-				if (trim)
-					limit = skb->len - trim;
-			}
-		}
+		if (tso_segs > 1)
+			limit = tcp_mss_split_point(sk, skb, mss_now,
+						    cwnd_quota);
 
 		if (skb->len > limit &&
 		    unlikely(tso_fragment(sk, skb, limit, mss_now)))
@@ -1496,7 +1504,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
 		/* Advance the send_head.  This one is sent out.
 		 * This call will increment packets_out.
 		 */
-		update_send_head(sk, skb);
+		tcp_event_new_data_sent(sk, skb);
 
 		tcp_minshall_update(tp, mss_now, skb);
 		sent_pkts++;
@@ -1529,7 +1537,6 @@ void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
  */
 void tcp_push_one(struct sock *sk, unsigned int mss_now)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb = tcp_send_head(sk);
 	unsigned int tso_segs, cwnd_quota;
 
@@ -1544,17 +1551,9 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
 		BUG_ON(!tso_segs);
 
 		limit = mss_now;
-		if (tso_segs > 1) {
-			limit = tcp_window_allows(tp, skb,
-						  mss_now, cwnd_quota);
-
-			if (skb->len < limit) {
-				unsigned int trim = skb->len % mss_now;
-
-				if (trim)
-					limit = skb->len - trim;
-			}
-		}
+		if (tso_segs > 1)
+			limit = tcp_mss_split_point(sk, skb, mss_now,
+						    cwnd_quota);
 
 		if (skb->len > limit &&
 		    unlikely(tso_fragment(sk, skb, limit, mss_now)))
@@ -1564,7 +1563,7 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
 		TCP_SKB_CB(skb)->when = tcp_time_stamp;
 
 		if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) {
-			update_send_head(sk, skb);
+			tcp_event_new_data_sent(sk, skb);
 			tcp_cwnd_validate(sk);
 			return;
 		}
@@ -1641,11 +1640,12 @@ u32 __tcp_select_window(struct sock *sk)
 	if (mss > full_space)
 		mss = full_space;
 
-	if (free_space < full_space/2) {
+	if (free_space < (full_space >> 1)) {
 		icsk->icsk_ack.quick = 0;
 
 		if (tcp_memory_pressure)
-			tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U*tp->advmss);
+			tp->rcv_ssthresh = min(tp->rcv_ssthresh,
+					       4U * tp->advmss);
 
 		if (free_space < mss)
 			return 0;
@@ -1678,9 +1678,9 @@ u32 __tcp_select_window(struct sock *sk)
 		 * is too small.
 		 */
 		if (window <= free_space - mss || window > free_space)
-			window = (free_space/mss)*mss;
+			window = (free_space / mss) * mss;
 		else if (mss == full_space &&
-			 free_space > window + full_space/2)
+			 free_space > window + (full_space >> 1))
 			window = free_space;
 	}
 
@@ -1688,86 +1688,82 @@ u32 __tcp_select_window(struct sock *sk)
 }
 
 /* Attempt to collapse two adjacent SKB's during retransmission. */
-static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int mss_now)
+static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb,
+				     int mss_now)
 {
 	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;
 
 	/* The first test we must make is that neither of these two
 	 * SKB's are still referenced by someone else.
 	 */
-	if (!skb_cloned(skb) && !skb_cloned(next_skb)) {
-		int skb_size = skb->len, next_skb_size = next_skb->len;
-		u16 flags = TCP_SKB_CB(skb)->flags;
+	if (skb_cloned(skb) || skb_cloned(next_skb))
+		return;
 
-		/* Also punt if next skb has been SACK'd. */
-		if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED)
-			return;
+	skb_size = skb->len;
+	next_skb_size = next_skb->len;
+	flags = TCP_SKB_CB(skb)->flags;
 
-		/* Next skb is out of window. */
-		if (after(TCP_SKB_CB(next_skb)->end_seq, tp->snd_una+tp->snd_wnd))
-			return;
+	/* Also punt if next skb has been SACK'd. */
+	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED)
+		return;
 
-		/* Punt if not enough space exists in the first SKB for
-		 * the data in the second, or the total combined payload
-		 * would exceed the MSS.
-		 */
-		if ((next_skb_size > skb_tailroom(skb)) ||
-		    ((skb_size + next_skb_size) > mss_now))
-			return;
+	/* Next skb is out of window. */
+	if (after(TCP_SKB_CB(next_skb)->end_seq, tcp_wnd_end(tp)))
+		return;
 
-		BUG_ON(tcp_skb_pcount(skb) != 1 ||
-		       tcp_skb_pcount(next_skb) != 1);
+	/* Punt if not enough space exists in the first SKB for
+	 * the data in the second, or the total combined payload
+	 * would exceed the MSS.
+	 */
+	if ((next_skb_size > skb_tailroom(skb)) ||
+	    ((skb_size + next_skb_size) > mss_now))
+		return;
 
-		if (WARN_ON(tcp_is_sack(tp) && tp->sacked_out &&
-		    (TCP_SKB_CB(next_skb)->seq == tp->highest_sack)))
-			return;
+	BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1);
 
-		/* Ok.	We will be able to collapse the packet. */
-		tcp_unlink_write_queue(next_skb, sk);
+	tcp_highest_sack_combine(sk, next_skb, skb);
 
-		skb_copy_from_linear_data(next_skb,
-					  skb_put(skb, next_skb_size),
-					  next_skb_size);
+	/* Ok.	We will be able to collapse the packet. */
+	tcp_unlink_write_queue(next_skb, sk);
 
-		if (next_skb->ip_summed == CHECKSUM_PARTIAL)
-			skb->ip_summed = CHECKSUM_PARTIAL;
+	skb_copy_from_linear_data(next_skb, skb_put(skb, next_skb_size),
+				  next_skb_size);
 
-		if (skb->ip_summed != CHECKSUM_PARTIAL)
-			skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
+	if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+		skb->ip_summed = CHECKSUM_PARTIAL;
 
-		/* Update sequence range on original skb. */
-		TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
 
-		/* Merge over control information. */
-		flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
-		TCP_SKB_CB(skb)->flags = flags;
+	/* Update sequence range on original skb. */
+	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
 
-		/* 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|TCPCB_AT_TAIL);
-		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(tp, 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);
-		/* manually tune sacktag skb hint */
-		if (tp->fastpath_skb_hint == next_skb) {
-			tp->fastpath_skb_hint = skb;
-			tp->fastpath_cnt_hint -= tcp_skb_pcount(skb);
-		}
+	/* Merge over control information. */
+	flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
+	TCP_SKB_CB(skb)->flags = flags;
 
-		sk_stream_free_skb(sk, next_skb);
-	}
+	/* 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);
+
+	sk_wmem_free_skb(sk, next_skb);
 }
 
 /* Do a simple retransmit without using the backoff mechanisms in
@@ -1786,12 +1782,12 @@ void tcp_simple_retransmit(struct sock *sk)
 		if (skb == tcp_send_head(sk))
 			break;
 		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_ACKED)) {
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
 				TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
 				tp->retrans_out -= tcp_skb_pcount(skb);
 			}
-			if (!(TCP_SKB_CB(skb)->sacked&TCPCB_LOST)) {
+			if (!(TCP_SKB_CB(skb)->sacked & TCPCB_LOST)) {
 				TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
 				tp->lost_out += tcp_skb_pcount(skb);
 				lost = 1;
@@ -1856,7 +1852,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	 * case, when window is shrunk to zero. In this case
 	 * our retransmit serves as a zero window probe.
 	 */
-	if (!before(TCP_SKB_CB(skb)->seq, tp->snd_una+tp->snd_wnd)
+	if (!before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))
 	    && TCP_SKB_CB(skb)->seq != tp->snd_una)
 		return -EAGAIN;
 
@@ -1870,8 +1866,10 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	    (skb->len < (cur_mss >> 1)) &&
 	    (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
 	    (!tcp_skb_is_last(sk, skb)) &&
-	    (skb_shinfo(skb)->nr_frags == 0 && skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
-	    (tcp_skb_pcount(skb) == 1 && tcp_skb_pcount(tcp_write_queue_next(sk, skb)) == 1) &&
+	    (skb_shinfo(skb)->nr_frags == 0 &&
+	     skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
+	    (tcp_skb_pcount(skb) == 1 &&
+	     tcp_skb_pcount(tcp_write_queue_next(sk, skb)) == 1) &&
 	    (sysctl_tcp_retrans_collapse != 0))
 		tcp_retrans_try_collapse(sk, skb, cur_mss);
 
@@ -1886,12 +1884,10 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	    (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
 	    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)->gso_segs = 1;
-			skb_shinfo(skb)->gso_size = 0;
-			skb_shinfo(skb)->gso_type = 0;
+			/* Reuse, even though it does some unnecessary work */
+			tcp_init_nondata_skb(skb, TCP_SKB_CB(skb)->end_seq - 1,
+					     TCP_SKB_CB(skb)->flags);
 			skb->ip_summed = CHECKSUM_NONE;
-			skb->csum = 0;
 		}
 	}
 
@@ -1909,7 +1905,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 		tp->total_retrans++;
 
 #if FASTRETRANS_DEBUG > 0
-		if (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) {
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
 			if (net_ratelimit())
 				printk(KERN_DEBUG "retrans_out leaked.\n");
 		}
@@ -1951,7 +1947,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 	if (tp->retransmit_skb_hint) {
 		skb = tp->retransmit_skb_hint;
 		packet_cnt = tp->retransmit_cnt_hint;
-	}else{
+	} else {
 		skb = tcp_write_queue_head(sk);
 		packet_cnt = 0;
 	}
@@ -1978,7 +1974,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 				return;
 
 			if (sacked & TCPCB_LOST) {
-				if (!(sacked&(TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
+				if (!(sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
 					if (tcp_retransmit_skb(sk, skb)) {
 						tp->retransmit_skb_hint = NULL;
 						return;
@@ -2036,7 +2032,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 			break;
 		tp->forward_skb_hint = skb;
 
-		if (after(TCP_SKB_CB(skb)->seq, tp->highest_sack))
+		if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
 			break;
 
 		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
@@ -2060,7 +2056,6 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 	}
 }
 
-
 /* Send a fin.  The caller locks the socket for us.  This cannot be
  * allowed to fail queueing a FIN frame under any circumstances.
  */
@@ -2091,16 +2086,9 @@ void tcp_send_fin(struct sock *sk)
 
 		/* Reserve space for headers and prepare control bits. */
 		skb_reserve(skb, MAX_TCP_HEADER);
-		skb->csum = 0;
-		TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
-		TCP_SKB_CB(skb)->sacked = 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;
-		TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
+		tcp_init_nondata_skb(skb, tp->write_seq,
+				     TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
 		tcp_queue_skb(sk, skb);
 	}
 	__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
@@ -2124,16 +2112,9 @@ 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);
-	skb->csum = 0;
-	TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
-	TCP_SKB_CB(skb)->sacked = 0;
-	skb_shinfo(skb)->gso_segs = 1;
-	skb_shinfo(skb)->gso_size = 0;
-	skb_shinfo(skb)->gso_type = 0;
-
+	tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
+			     TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
 	/* Send it off. */
-	TCP_SKB_CB(skb)->seq = tcp_acceptable_seq(sk);
-	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, 0, priority))
 		NET_INC_STATS(LINUX_MIB_TCPABORTFAILED);
@@ -2146,14 +2127,14 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
  */
 int tcp_send_synack(struct sock *sk)
 {
-	struct sk_buff* skb;
+	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 & TCPCB_FLAG_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 & TCPCB_FLAG_ACK)) {
 		if (skb_cloned(skb)) {
 			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
 			if (nskb == NULL)
@@ -2161,8 +2142,9 @@ int tcp_send_synack(struct sock *sk)
 			tcp_unlink_write_queue(skb, sk);
 			skb_header_release(nskb);
 			__tcp_add_write_queue_head(sk, nskb);
-			sk_stream_free_skb(sk, skb);
-			sk_charge_skb(sk, nskb);
+			sk_wmem_free_skb(sk, skb);
+			sk->sk_wmem_queued += nskb->truesize;
+			sk_mem_charge(sk, nskb->truesize);
 			skb = nskb;
 		}
 
@@ -2176,8 +2158,8 @@ int tcp_send_synack(struct sock *sk)
 /*
  * Prepare a SYN-ACK.
  */
-struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
-				 struct request_sock *req)
+struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
+				struct request_sock *req)
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -2220,12 +2202,11 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	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)->gso_segs = 1;
-	skb_shinfo(skb)->gso_size = 0;
-	skb_shinfo(skb)->gso_type = 0;
+	/* Setting of flags are superfluous here for callers (and ECE is
+	 * not even correctly set)
+	 */
+	tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
+			     TCPCB_FLAG_SYN | TCPCB_FLAG_ACK);
 	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 */
@@ -2257,7 +2238,6 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 			       NULL)
 			      );
 
-	skb->csum = 0;
 	th->doff = (tcp_header_size >> 2);
 	TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
@@ -2349,23 +2329,17 @@ int tcp_connect(struct sock *sk)
 	/* Reserve space for headers. */
 	skb_reserve(buff, MAX_TCP_HEADER);
 
-	TCP_SKB_CB(buff)->flags = TCPCB_FLAG_SYN;
-	TCP_ECN_send_syn(sk, buff);
-	TCP_SKB_CB(buff)->sacked = 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;
+	tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN);
+	TCP_ECN_send_syn(sk, buff);
 
 	/* Send it off. */
 	TCP_SKB_CB(buff)->when = tcp_time_stamp;
 	tp->retrans_stamp = TCP_SKB_CB(buff)->when;
 	skb_header_release(buff);
 	__tcp_add_write_queue_tail(sk, buff);
-	sk_charge_skb(sk, buff);
+	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, GFP_KERNEL);
 
@@ -2394,9 +2368,10 @@ void tcp_send_delayed_ack(struct sock *sk)
 
 	if (ato > TCP_DELACK_MIN) {
 		const struct tcp_sock *tp = tcp_sk(sk);
-		int max_ato = HZ/2;
+		int max_ato = HZ / 2;
 
-		if (icsk->icsk_ack.pingpong || (icsk->icsk_ack.pending & ICSK_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". */
@@ -2406,7 +2381,7 @@ void tcp_send_delayed_ack(struct sock *sk)
 		 * directly.
 		 */
 		if (tp->srtt) {
-			int rtt = max(tp->srtt>>3, TCP_DELACK_MIN);
+			int rtt = max(tp->srtt >> 3, TCP_DELACK_MIN);
 
 			if (rtt < max_ato)
 				max_ato = rtt;
@@ -2440,37 +2415,32 @@ void tcp_send_delayed_ack(struct sock *sk)
 /* This routine sends an ack and also updates the window. */
 void tcp_send_ack(struct sock *sk)
 {
-	/* If we have been reset, we may not send again. */
-	if (sk->sk_state != TCP_CLOSE) {
-		struct sk_buff *buff;
+	struct sk_buff *buff;
 
-		/* We are not putting this on the write queue, so
-		 * tcp_transmit_skb() will set the ownership to this
-		 * sock.
-		 */
-		buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
-		if (buff == NULL) {
-			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;
-		}
+	/* If we have been reset, we may not send again. */
+	if (sk->sk_state == TCP_CLOSE)
+		return;
 
-		/* Reserve space for headers and prepare control bits. */
-		skb_reserve(buff, MAX_TCP_HEADER);
-		buff->csum = 0;
-		TCP_SKB_CB(buff)->flags = TCPCB_FLAG_ACK;
-		TCP_SKB_CB(buff)->sacked = 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);
-		TCP_SKB_CB(buff)->when = tcp_time_stamp;
-		tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
+	/* We are not putting this on the write queue, so
+	 * tcp_transmit_skb() will set the ownership to this
+	 * sock.
+	 */
+	buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+	if (buff == NULL) {
+		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;
 	}
+
+	/* 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);
+
+	/* Send it off, this clears delayed acks for us. */
+	TCP_SKB_CB(buff)->when = tcp_time_stamp;
+	tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
 }
 
 /* This routine sends a packet with an out of date sequence
@@ -2496,66 +2466,57 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 
 	/* Reserve space for headers and set control bits. */
 	skb_reserve(skb, MAX_TCP_HEADER);
-	skb->csum = 0;
-	TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
-	TCP_SKB_CB(skb)->sacked = urgent;
-	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
 	 * send it.
 	 */
-	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_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
 	return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
 }
 
 int tcp_write_wakeup(struct sock *sk)
 {
-	if (sk->sk_state != TCP_CLOSE) {
-		struct tcp_sock *tp = tcp_sk(sk);
-		struct sk_buff *skb;
-
-		if ((skb = tcp_send_head(sk)) != NULL &&
-		    before(TCP_SKB_CB(skb)->seq, tp->snd_una+tp->snd_wnd)) {
-			int err;
-			unsigned int mss = tcp_current_mss(sk, 0);
-			unsigned int seg_size = tp->snd_una+tp->snd_wnd-TCP_SKB_CB(skb)->seq;
-
-			if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))
-				tp->pushed_seq = TCP_SKB_CB(skb)->end_seq;
-
-			/* We are probing the opening of a window
-			 * but the window size is != 0
-			 * must have been a result SWS avoidance ( sender )
-			 */
-			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;
-				if (tcp_fragment(sk, skb, seg_size, mss))
-					return -1;
-			} else if (!tcp_skb_pcount(skb))
-				tcp_set_skb_tso_segs(sk, skb, mss);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	if (sk->sk_state == TCP_CLOSE)
+		return -1;
+
+	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 seg_size = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
+
+		if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))
+			tp->pushed_seq = TCP_SKB_CB(skb)->end_seq;
 
+		/* We are probing the opening of a window
+		 * but the window size is != 0
+		 * must have been a result SWS avoidance ( sender )
+		 */
+		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)->when = tcp_time_stamp;
-			err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
-			if (!err) {
-				update_send_head(sk, skb);
-			}
-			return err;
-		} else {
-			if (tp->urg_mode &&
-			    between(tp->snd_up, tp->snd_una+1, tp->snd_una+0xFFFF))
-				tcp_xmit_probe_skb(sk, TCPCB_URG);
-			return tcp_xmit_probe_skb(sk, 0);
-		}
+			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)->when = tcp_time_stamp;
+		err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
+		if (!err)
+			tcp_event_new_data_sent(sk, skb);
+		return err;
+	} else {
+		if (tp->urg_mode &&
+		    between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
+			tcp_xmit_probe_skb(sk, 1);
+		return tcp_xmit_probe_skb(sk, 0);
 	}
-	return -1;
 }
 
 /* A window probe timeout has occurred.  If window is not closed send
@@ -2603,5 +2564,4 @@ 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);