Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
[sfrench/cifs-2.6.git] / net / ipv4 / tcp_output.c
index 324b4207254ae411728dd8a3cc1740f5ac0ce267..ed750f9ceb07caed9ed5479740e664c6a319bc8f 100644 (file)
@@ -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_buffskb;
+       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);