Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 into common/serial-rework

Conflicts:
	arch/sh/kernel/cpu/sh2/setup-sh7619.c
	arch/sh/kernel/cpu/sh2a/setup-mxg.c
	arch/sh/kernel/cpu/sh2a/setup-sh7201.c
	arch/sh/kernel/cpu/sh2a/setup-sh7203.c
	arch/sh/kernel/cpu/sh2a/setup-sh7206.c
	arch/sh/kernel/cpu/sh3/setup-sh7705.c
	arch/sh/kernel/cpu/sh3/setup-sh770x.c
	arch/sh/kernel/cpu/sh3/setup-sh7710.c
	arch/sh/kernel/cpu/sh3/setup-sh7720.c
	arch/sh/kernel/cpu/sh4/setup-sh4-202.c
	arch/sh/kernel/cpu/sh4/setup-sh7750.c
	arch/sh/kernel/cpu/sh4/setup-sh7760.c
	arch/sh/kernel/cpu/sh4a/setup-sh7343.c
	arch/sh/kernel/cpu/sh4a/setup-sh7366.c
	arch/sh/kernel/cpu/sh4a/setup-sh7722.c
	arch/sh/kernel/cpu/sh4a/setup-sh7723.c
	arch/sh/kernel/cpu/sh4a/setup-sh7724.c
	arch/sh/kernel/cpu/sh4a/setup-sh7763.c
	arch/sh/kernel/cpu/sh4a/setup-sh7770.c
	arch/sh/kernel/cpu/sh4a/setup-sh7780.c
	arch/sh/kernel/cpu/sh4a/setup-sh7785.c
	arch/sh/kernel/cpu/sh4a/setup-sh7786.c
	arch/sh/kernel/cpu/sh4a/setup-shx3.c
	arch/sh/kernel/cpu/sh5/setup-sh5.c
	drivers/serial/sh-sci.c
	drivers/serial/sh-sci.h
	include/linux/serial_sci.h

1 files changed, 421 insertions, 151 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 416fc4c2e7eb..dc7c096ddfef 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -37,6 +37,7 @@
 #include <net/tcp.h>
 
 #include <linux/compiler.h>
+#include <linux/gfp.h>
 #include <linux/module.h>
 
 /* People can turn this off for buggy TCP's found in printers etc. */
@@ -54,11 +55,16 @@ int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
 int sysctl_tcp_tso_win_divisor __read_mostly = 3;
 
 int sysctl_tcp_mtu_probing __read_mostly = 0;
-int sysctl_tcp_base_mss __read_mostly = 512;
+int sysctl_tcp_base_mss __read_mostly = TCP_BASE_MSS;
 
 /* By default, RFC2861 behavior.  */
 int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
 
+int sysctl_tcp_cookie_size __read_mostly = 0; /* TCP_COOKIE_MAX */
+EXPORT_SYMBOL_GPL(sysctl_tcp_cookie_size);
+
+
+/* Account for new data that has been sent to the network. */
 static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb)
 {
         struct tcp_sock *tp = tcp_sk(sk);
@@ -113,9 +119,13 @@ static __u16 tcp_advertise_mss(struct sock *sk)
         struct dst_entry *dst = __sk_dst_get(sk);
         int mss = tp->advmss;
 
-        if (dst && dst_metric(dst, RTAX_ADVMSS) < mss) {
-                mss = dst_metric(dst, RTAX_ADVMSS);
-                tp->advmss = mss;
+        if (dst) {
+                unsigned int metric = dst_metric_advmss(dst);
+
+                if (metric < mss) {
+                        mss = metric;
+                        tp->advmss = mss;
+                }
         }
 
         return (__u16)mss;
@@ -142,6 +152,7 @@ static void tcp_cwnd_restart(struct sock *sk, struct dst_entry *dst)
         tp->snd_cwnd_used = 0;
 }
 
+/* Congestion state accounting after a packet has been sent. */
 static void tcp_event_data_sent(struct tcp_sock *tp,
                                 struct sk_buff *skb, struct sock *sk)
 {
@@ -161,6 +172,7 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
                 icsk->icsk_ack.pingpong = 1;
 }
 
+/* Account for an ACK we sent. */
 static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
 {
         tcp_dec_quickack_mode(sk, pkts);
@@ -176,7 +188,8 @@ static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
  */
 void tcp_select_initial_window(int __space, __u32 mss,
                                __u32 *rcv_wnd, __u32 *window_clamp,
-                               int wscale_ok, __u8 *rcv_wscale)
+                               int wscale_ok, __u8 *rcv_wscale,
+                               __u32 init_rcv_wnd)
 {
         unsigned int space = (__space < 0 ? 0 : __space);
 
@@ -215,23 +228,28 @@ void tcp_select_initial_window(int __space, __u32 mss,
                 }
         }
 
-        /* Set initial window to value enough for senders,
-         * following RFC2414. Senders, not following this RFC,
-         * will be satisfied with 2.
+        /* Set initial window to a value enough for senders starting with
+         * initial congestion window of TCP_DEFAULT_INIT_RCVWND. Place
+         * a limit on the initial window when mss is larger than 1460.
          */
         if (mss > (1 << *rcv_wscale)) {
-                int init_cwnd = 4;
-                if (mss > 1460 * 3)
-                        init_cwnd = 2;
-                else if (mss > 1460)
-                        init_cwnd = 3;
-                if (*rcv_wnd > init_cwnd * mss)
-                        *rcv_wnd = init_cwnd * mss;
+                int init_cwnd = TCP_DEFAULT_INIT_RCVWND;
+                if (mss > 1460)
+                        init_cwnd =
+                        max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2);
+                /* when initializing use the value from init_rcv_wnd
+                 * rather than the default from above
+                 */
+                if (init_rcv_wnd)
+                        *rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss);
+                else
+                        *rcv_wnd = min(*rcv_wnd, init_cwnd * mss);
         }
 
         /* Set the clamp no higher than max representable value */
         (*window_clamp) = min(65535U << (*rcv_wscale), *window_clamp);
 }
+EXPORT_SYMBOL(tcp_select_initial_window);
 
 /* Chose a new window to advertise, update state in tcp_sock for the
  * socket, and return result with RFC1323 scaling applied.  The return
@@ -276,20 +294,22 @@ static u16 tcp_select_window(struct sock *sk)
         return new_win;
 }
 
+/* Packet ECN state for a SYN-ACK */
 static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
 {
-        TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
+        TCP_SKB_CB(skb)->flags &= ~TCPHDR_CWR;
         if (!(tp->ecn_flags & TCP_ECN_OK))
-                TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
+                TCP_SKB_CB(skb)->flags &= ~TCPHDR_ECE;
 }
 
+/* Packet ECN state for a SYN.  */
 static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
 {
         struct tcp_sock *tp = tcp_sk(sk);
 
         tp->ecn_flags = 0;
         if (sysctl_tcp_ecn == 1) {
-                TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR;
+                TCP_SKB_CB(skb)->flags |= TCPHDR_ECE | TCPHDR_CWR;
                 tp->ecn_flags = TCP_ECN_OK;
         }
 }
@@ -301,6 +321,9 @@ TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th)
                 th->ece = 1;
 }
 
+/* Set up ECN state for a packet on a ESTABLISHED socket that is about to
+ * be sent.
+ */
 static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
                                 int tcp_header_len)
 {
@@ -330,6 +353,7 @@ static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
  */
 static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
 {
+        skb->ip_summed = CHECKSUM_PARTIAL;
         skb->csum = 0;
 
         TCP_SKB_CB(skb)->flags = flags;
@@ -340,7 +364,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
         skb_shinfo(skb)->gso_type = 0;
 
         TCP_SKB_CB(skb)->seq = seq;
-        if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN))
+        if (flags & (TCPHDR_SYN | TCPHDR_FIN))
                 seq++;
         TCP_SKB_CB(skb)->end_seq = seq;
 }
@@ -353,16 +377,52 @@ static inline int tcp_urg_mode(const struct tcp_sock *tp)
 #define OPTION_SACK_ADVERTISE   (1 << 0)
 #define OPTION_TS               (1 << 1)
 #define OPTION_MD5              (1 << 2)
+#define OPTION_WSCALE           (1 << 3)
+#define OPTION_COOKIE_EXTENSION (1 << 4)
 
 struct tcp_out_options {
         u8 options;             /* bit field of OPTION_* */
         u8 ws;                  /* window scale, 0 to disable */
         u8 num_sack_blocks;     /* number of SACK blocks to include */
+        u8 hash_size;           /* bytes in hash_location */
         u16 mss;                /* 0 to disable */
         __u32 tsval, tsecr;     /* need to include OPTION_TS */
+        __u8 *hash_location;    /* temporary pointer, overloaded */
 };
 
-/* Beware: Something in the Internet is very sensitive to the ordering of
+/* The sysctl int routines are generic, so check consistency here.
+ */
+static u8 tcp_cookie_size_check(u8 desired)
+{
+        int cookie_size;
+
+        if (desired > 0)
+                /* previously specified */
+                return desired;
+
+        cookie_size = ACCESS_ONCE(sysctl_tcp_cookie_size);
+        if (cookie_size <= 0)
+                /* no default specified */
+                return 0;
+
+        if (cookie_size <= TCP_COOKIE_MIN)
+                /* value too small, specify minimum */
+                return TCP_COOKIE_MIN;
+
+        if (cookie_size >= TCP_COOKIE_MAX)
+                /* value too large, specify maximum */
+                return TCP_COOKIE_MAX;
+
+        if (cookie_size & 1)
+                /* 8-bit multiple, illegal, fix it */
+                cookie_size++;
+
+        return (u8)cookie_size;
+}
+
+/* Write previously computed TCP options to the packet.
+ *
+ * Beware: Something in the Internet is very sensitive to the ordering of
  * TCP options, we learned this through the hard way, so be careful here.
  * Luckily we can at least blame others for their non-compliance but from
  * inter-operatibility perspective it seems that we're somewhat stuck with
@@ -374,17 +434,34 @@ struct tcp_out_options {
  * (but it may well be that other scenarios fail similarly).
  */
 static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
-                              const struct tcp_out_options *opts,
-                              __u8 **md5_hash) {
-        if (unlikely(OPTION_MD5 & opts->options)) {
-                *ptr++ = htonl((TCPOPT_NOP << 24) |
-                               (TCPOPT_NOP << 16) |
-                               (TCPOPT_MD5SIG << 8) |
-                               TCPOLEN_MD5SIG);
-                *md5_hash = (__u8 *)ptr;
+                              struct tcp_out_options *opts)
+{
+        u8 options = opts->options;     /* mungable copy */
+
+        /* Having both authentication and cookies for security is redundant,
+         * and there's certainly not enough room.  Instead, the cookie-less
+         * extension variant is proposed.
+         *
+         * Consider the pessimal case with authentication.  The options
+         * could look like:
+         *   COOKIE|MD5(20) + MSS(4) + SACK|TS(12) + WSCALE(4) == 40
+         */
+        if (unlikely(OPTION_MD5 & options)) {
+                if (unlikely(OPTION_COOKIE_EXTENSION & options)) {
+                        *ptr++ = htonl((TCPOPT_COOKIE << 24) |
+                                       (TCPOLEN_COOKIE_BASE << 16) |
+                                       (TCPOPT_MD5SIG << 8) |
+                                       TCPOLEN_MD5SIG);
+                } else {
+                        *ptr++ = htonl((TCPOPT_NOP << 24) |
+                                       (TCPOPT_NOP << 16) |
+                                       (TCPOPT_MD5SIG << 8) |
+                                       TCPOLEN_MD5SIG);
+                }
+                options &= ~OPTION_COOKIE_EXTENSION;
+                /* overload cookie hash location */
+                opts->hash_location = (__u8 *)ptr;
                 ptr += 4;
-        } else {
-                *md5_hash = NULL;
         }
 
         if (unlikely(opts->mss)) {
@@ -393,12 +470,13 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
                                opts->mss);
         }
 
-        if (likely(OPTION_TS & opts->options)) {
-                if (unlikely(OPTION_SACK_ADVERTISE & opts->options)) {
+        if (likely(OPTION_TS & options)) {
+                if (unlikely(OPTION_SACK_ADVERTISE & options)) {
                         *ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
                                        (TCPOLEN_SACK_PERM << 16) |
                                        (TCPOPT_TIMESTAMP << 8) |
                                        TCPOLEN_TIMESTAMP);
+                        options &= ~OPTION_SACK_ADVERTISE;
                 } else {
                         *ptr++ = htonl((TCPOPT_NOP << 24) |
                                        (TCPOPT_NOP << 16) |
@@ -409,15 +487,52 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
                 *ptr++ = htonl(opts->tsecr);
         }
 
-        if (unlikely(OPTION_SACK_ADVERTISE & opts->options &&
-                     !(OPTION_TS & opts->options))) {
+        /* Specification requires after timestamp, so do it now.
+         *
+         * Consider the pessimal case without authentication.  The options
+         * could look like:
+         *   MSS(4) + SACK|TS(12) + COOKIE(20) + WSCALE(4) == 40
+         */
+        if (unlikely(OPTION_COOKIE_EXTENSION & options)) {
+                __u8 *cookie_copy = opts->hash_location;
+                u8 cookie_size = opts->hash_size;
+
+                /* 8-bit multiple handled in tcp_cookie_size_check() above,
+                 * and elsewhere.
+                 */
+                if (0x2 & cookie_size) {
+                        __u8 *p = (__u8 *)ptr;
+
+                        /* 16-bit multiple */
+                        *p++ = TCPOPT_COOKIE;
+                        *p++ = TCPOLEN_COOKIE_BASE + cookie_size;
+                        *p++ = *cookie_copy++;
+                        *p++ = *cookie_copy++;
+                        ptr++;
+                        cookie_size -= 2;
+                } else {
+                        /* 32-bit multiple */
+                        *ptr++ = htonl(((TCPOPT_NOP << 24) |
+                                        (TCPOPT_NOP << 16) |
+                                        (TCPOPT_COOKIE << 8) |
+                                        TCPOLEN_COOKIE_BASE) +
+                                       cookie_size);
+                }
+
+                if (cookie_size > 0) {
+                        memcpy(ptr, cookie_copy, cookie_size);
+                        ptr += (cookie_size / 4);
+                }
+        }
+
+        if (unlikely(OPTION_SACK_ADVERTISE & options)) {
                 *ptr++ = htonl((TCPOPT_NOP << 24) |
                                (TCPOPT_NOP << 16) |
                                (TCPOPT_SACK_PERM << 8) |
                                TCPOLEN_SACK_PERM);
         }
 
-        if (unlikely(opts->ws)) {
+        if (unlikely(OPTION_WSCALE & options)) {
                 *ptr++ = htonl((TCPOPT_NOP << 24) |
                                (TCPOPT_WINDOW << 16) |
                                (TCPOLEN_WINDOW << 8) |
@@ -445,17 +560,24 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
         }
 }
 
+/* Compute TCP options for SYN packets. This is not the final
+ * network wire format yet.
+ */
 static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
                                 struct tcp_out_options *opts,
                                 struct tcp_md5sig_key **md5) {
         struct tcp_sock *tp = tcp_sk(sk);
-        unsigned size = 0;
+        struct tcp_cookie_values *cvp = tp->cookie_values;
+        unsigned remaining = MAX_TCP_OPTION_SPACE;
+        u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ?
+                         tcp_cookie_size_check(cvp->cookie_desired) :
+                         0;
 
 #ifdef CONFIG_TCP_MD5SIG
         *md5 = tp->af_specific->md5_lookup(sk, sk);
         if (*md5) {
                 opts->options |= OPTION_MD5;
-                size += TCPOLEN_MD5SIG_ALIGNED;
+                remaining -= TCPOLEN_MD5SIG_ALIGNED;
         }
 #else
         *md5 = NULL;
@@ -471,76 +593,154 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
          * SACKs don't matter, we never delay an ACK when we have any of those
          * going out.  */
         opts->mss = tcp_advertise_mss(sk);
-        size += TCPOLEN_MSS_ALIGNED;
+        remaining -= TCPOLEN_MSS_ALIGNED;
 
         if (likely(sysctl_tcp_timestamps && *md5 == NULL)) {
                 opts->options |= OPTION_TS;
                 opts->tsval = TCP_SKB_CB(skb)->when;
                 opts->tsecr = tp->rx_opt.ts_recent;
-                size += TCPOLEN_TSTAMP_ALIGNED;
+                remaining -= TCPOLEN_TSTAMP_ALIGNED;
         }
         if (likely(sysctl_tcp_window_scaling)) {
                 opts->ws = tp->rx_opt.rcv_wscale;
-                if (likely(opts->ws))
-                        size += TCPOLEN_WSCALE_ALIGNED;
+                opts->options |= OPTION_WSCALE;
+                remaining -= TCPOLEN_WSCALE_ALIGNED;
         }
         if (likely(sysctl_tcp_sack)) {
                 opts->options |= OPTION_SACK_ADVERTISE;
                 if (unlikely(!(OPTION_TS & opts->options)))
-                        size += TCPOLEN_SACKPERM_ALIGNED;
+                        remaining -= TCPOLEN_SACKPERM_ALIGNED;
         }
 
-        return size;
+        /* Note that timestamps are required by the specification.
+         *
+         * Odd numbers of bytes are prohibited by the specification, ensuring
+         * that the cookie is 16-bit aligned, and the resulting cookie pair is
+         * 32-bit aligned.
+         */
+        if (*md5 == NULL &&
+            (OPTION_TS & opts->options) &&
+            cookie_size > 0) {
+                int need = TCPOLEN_COOKIE_BASE + cookie_size;
+
+                if (0x2 & need) {
+                        /* 32-bit multiple */
+                        need += 2; /* NOPs */
+
+                        if (need > remaining) {
+                                /* try shrinking cookie to fit */
+                                cookie_size -= 2;
+                                need -= 4;
+                        }
+                }
+                while (need > remaining && TCP_COOKIE_MIN <= cookie_size) {
+                        cookie_size -= 4;
+                        need -= 4;
+                }
+                if (TCP_COOKIE_MIN <= cookie_size) {
+                        opts->options |= OPTION_COOKIE_EXTENSION;
+                        opts->hash_location = (__u8 *)&cvp->cookie_pair[0];
+                        opts->hash_size = cookie_size;
+
+                        /* Remember for future incarnations. */
+                        cvp->cookie_desired = cookie_size;
+
+                        if (cvp->cookie_desired != cvp->cookie_pair_size) {
+                                /* Currently use random bytes as a nonce,
+                                 * assuming these are completely unpredictable
+                                 * by hostile users of the same system.
+                                 */
+                                get_random_bytes(&cvp->cookie_pair[0],
+                                                 cookie_size);
+                                cvp->cookie_pair_size = cookie_size;
+                        }
+
+                        remaining -= need;
+                }
+        }
+        return MAX_TCP_OPTION_SPACE - remaining;
 }
 
+/* Set up TCP options for SYN-ACKs. */
 static unsigned tcp_synack_options(struct sock *sk,
                                    struct request_sock *req,
                                    unsigned mss, struct sk_buff *skb,
                                    struct tcp_out_options *opts,
-                                   struct tcp_md5sig_key **md5) {
-        unsigned size = 0;
+                                   struct tcp_md5sig_key **md5,
+                                   struct tcp_extend_values *xvp)
+{
         struct inet_request_sock *ireq = inet_rsk(req);
-        char doing_ts;
+        unsigned remaining = MAX_TCP_OPTION_SPACE;
+        u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ?
+                         xvp->cookie_plus :
+                         0;
 
 #ifdef CONFIG_TCP_MD5SIG
         *md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
         if (*md5) {
                 opts->options |= OPTION_MD5;
-                size += TCPOLEN_MD5SIG_ALIGNED;
+                remaining -= TCPOLEN_MD5SIG_ALIGNED;
+
+                /* We can't fit any SACK blocks in a packet with MD5 + TS
+                 * options. There was discussion about disabling SACK
+                 * rather than TS in order to fit in better with old,
+                 * buggy kernels, but that was deemed to be unnecessary.
+                 */
+                ireq->tstamp_ok &= !ireq->sack_ok;
         }
 #else
         *md5 = NULL;
 #endif
 
-        /* we can't fit any SACK blocks in a packet with MD5 + TS
-           options. There was discussion about disabling SACK rather than TS in
-           order to fit in better with old, buggy kernels, but that was deemed
-           to be unnecessary. */
-        doing_ts = ireq->tstamp_ok && !(*md5 && ireq->sack_ok);
-
+        /* We always send an MSS option. */
         opts->mss = mss;
-        size += TCPOLEN_MSS_ALIGNED;
+        remaining -= TCPOLEN_MSS_ALIGNED;
 
         if (likely(ireq->wscale_ok)) {
                 opts->ws = ireq->rcv_wscale;
-                if (likely(opts->ws))
-                        size += TCPOLEN_WSCALE_ALIGNED;
+                opts->options |= OPTION_WSCALE;
+                remaining -= TCPOLEN_WSCALE_ALIGNED;
         }
-        if (likely(doing_ts)) {
+        if (likely(ireq->tstamp_ok)) {
                 opts->options |= OPTION_TS;
                 opts->tsval = TCP_SKB_CB(skb)->when;
                 opts->tsecr = req->ts_recent;
-                size += TCPOLEN_TSTAMP_ALIGNED;
+                remaining -= TCPOLEN_TSTAMP_ALIGNED;
         }
         if (likely(ireq->sack_ok)) {
                 opts->options |= OPTION_SACK_ADVERTISE;
-                if (unlikely(!doing_ts))
-                        size += TCPOLEN_SACKPERM_ALIGNED;
+                if (unlikely(!ireq->tstamp_ok))
+                        remaining -= TCPOLEN_SACKPERM_ALIGNED;
         }
 
-        return size;
+        /* Similar rationale to tcp_syn_options() applies here, too.
+         * If the <SYN> options fit, the same options should fit now!
+         */
+        if (*md5 == NULL &&
+            ireq->tstamp_ok &&
+            cookie_plus > TCPOLEN_COOKIE_BASE) {
+                int need = cookie_plus; /* has TCPOLEN_COOKIE_BASE */
+
+                if (0x2 & need) {
+                        /* 32-bit multiple */
+                        need += 2; /* NOPs */
+                }
+                if (need <= remaining) {
+                        opts->options |= OPTION_COOKIE_EXTENSION;
+                        opts->hash_size = cookie_plus - TCPOLEN_COOKIE_BASE;
+                        remaining -= need;
+                } else {
+                        /* There's no error return, so flag it. */
+                        xvp->cookie_out_never = 1; /* true */
+                        opts->hash_size = 0;
+                }
+        }
+        return MAX_TCP_OPTION_SPACE - remaining;
 }
 
+/* Compute TCP options for ESTABLISHED sockets. This is not the
+ * final wire format yet.
+ */
 static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
                                         struct tcp_out_options *opts,
                                         struct tcp_md5sig_key **md5) {
@@ -601,7 +801,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
         struct tcp_out_options opts;
         unsigned tcp_options_size, tcp_header_size;
         struct tcp_md5sig_key *md5;
-        __u8 *md5_hash_location;
         struct tcphdr *th;
         int err;
 
@@ -627,15 +826,18 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
         tcb = TCP_SKB_CB(skb);
         memset(&opts, 0, sizeof(opts));
 
-        if (unlikely(tcb->flags & TCPCB_FLAG_SYN))
+        if (unlikely(tcb->flags & TCPHDR_SYN))
                 tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
         else
                 tcp_options_size = tcp_established_options(sk, skb, &opts,
                                                            &md5);
         tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
 
-        if (tcp_packets_in_flight(tp) == 0)
+        if (tcp_packets_in_flight(tp) == 0) {
                 tcp_ca_event(sk, CA_EVENT_TX_START);
+                skb->ooo_okay = 1;
+        } else
+                skb->ooo_okay = 0;
 
         skb_push(skb, tcp_header_size);
         skb_reset_transport_header(skb);
@@ -643,14 +845,14 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
         /* Build TCP header and checksum it. */
         th = tcp_hdr(skb);
-        th->source              = inet->sport;
-        th->dest                = inet->dport;
+        th->source              = inet->inet_sport;
+        th->dest                = inet->inet_dport;
         th->seq                 = htonl(tcb->seq);
         th->ack_seq             = htonl(tp->rcv_nxt);
         *(((__be16 *)th) + 6)   = htons(((tcp_header_size >> 2) << 12) |
                                         tcb->flags);
 
-        if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+        if (unlikely(tcb->flags & TCPHDR_SYN)) {
                 /* RFC1323: The window in SYN & SYN/ACK segments
                  * is never scaled.
                  */
@@ -667,36 +869,37 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
                         th->urg_ptr = htons(tp->snd_up - tcb->seq);
                         th->urg = 1;
                 } else if (after(tcb->seq + 0xFFFF, tp->snd_nxt)) {
-                        th->urg_ptr = 0xFFFF;
+                        th->urg_ptr = htons(0xFFFF);
                         th->urg = 1;
                 }
         }
 
-        tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
-        if (likely((tcb->flags & TCPCB_FLAG_SYN) == 0))
+        tcp_options_write((__be32 *)(th + 1), tp, &opts);
+        if (likely((tcb->flags & TCPHDR_SYN) == 0))
                 TCP_ECN_send(sk, skb, tcp_header_size);
 
 #ifdef CONFIG_TCP_MD5SIG
         /* Calculate the MD5 hash, as we have all we need now */
         if (md5) {
-                sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
-                tp->af_specific->calc_md5_hash(md5_hash_location,
+                sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+                tp->af_specific->calc_md5_hash(opts.hash_location,
                                                md5, sk, NULL, skb);
         }
 #endif
 
-        icsk->icsk_af_ops->send_check(sk, skb->len, skb);
+        icsk->icsk_af_ops->send_check(sk, skb);
 
-        if (likely(tcb->flags & TCPCB_FLAG_ACK))
+        if (likely(tcb->flags & TCPHDR_ACK))
                 tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
 
         if (skb->len != tcp_header_size)
                 tcp_event_data_sent(tp, skb, sk);
 
         if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
-                TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
+                TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS,
+                              tcp_skb_pcount(skb));
 
-        err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+        err = icsk->icsk_af_ops->queue_xmit(skb);
         if (likely(err <= 0))
                 return err;
 
@@ -705,7 +908,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
         return net_xmit_eval(err);
 }
 
-/* This routine just queue's the buffer
+/* This routine just queues the buffer for sending.
  *
  * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames,
  * otherwise socket can stall.
@@ -722,10 +925,12 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
         sk_mem_charge(sk, skb->truesize);
 }
 
+/* Initialize TSO segments for a packet. */
 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)) {
+        if (skb->len <= mss_now || !sk_can_gso(sk) ||
+            skb->ip_summed == CHECKSUM_NONE) {
                 /* Avoid the costly divide in the normal
                  * non-TSO case.
                  */
@@ -827,7 +1032,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
 
         /* PSH and FIN should only be set in the second packet. */
         flags = TCP_SKB_CB(skb)->flags;
-        TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+        TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
         TCP_SKB_CB(buff)->flags = flags;
         TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
 
@@ -908,6 +1113,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
         skb->len = skb->data_len;
 }
 
+/* Remove acked data from a packet in the transmit queue. */
 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))
@@ -936,7 +1142,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
         return 0;
 }
 
-/* Not accounting for SACKs here. */
+/* Calculate MSS. Not accounting for SACKs here.  */
 int tcp_mtu_to_mss(struct sock *sk, int pmtu)
 {
         struct tcp_sock *tp = tcp_sk(sk);
@@ -980,6 +1186,7 @@ int tcp_mss_to_mtu(struct sock *sk, int mss)
         return mtu;
 }
 
+/* MTU probing init per socket */
 void tcp_mtup_init(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
@@ -991,6 +1198,7 @@ void tcp_mtup_init(struct sock *sk)
         icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
         icsk->icsk_mtup.probe_size = 0;
 }
+EXPORT_SYMBOL(tcp_mtup_init);
 
 /* This function synchronize snd mss to current pmtu/exthdr set.
 
@@ -1034,6 +1242,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 
         return mss_now;
 }
+EXPORT_SYMBOL(tcp_sync_mss);
 
 /* Compute the current effective MSS, taking SACKs and IP options,
  * and even PMTU discovery events into account.
@@ -1130,8 +1339,7 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
         u32 in_flight, cwnd;
 
         /* Don't be strict about the congestion window for the final FIN.  */
-        if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
-            tcp_skb_pcount(skb) == 1)
+        if ((TCP_SKB_CB(skb)->flags & TCPHDR_FIN) && tcp_skb_pcount(skb) == 1)
                 return 1;
 
         in_flight = tcp_packets_in_flight(tp);
@@ -1142,7 +1350,8 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
         return 0;
 }
 
-/* This must be invoked the first time we consider transmitting
+/* Intialize TSO state of a skb.
+ * 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,
@@ -1157,6 +1366,7 @@ static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb,
         return tso_segs;
 }
 
+/* Minshall's variant of the Nagle send check. */
 static inline int tcp_minshall_check(const struct tcp_sock *tp)
 {
         return after(tp->snd_sml, tp->snd_una) &&
@@ -1174,9 +1384,9 @@ static inline int tcp_nagle_check(const struct tcp_sock *tp,
                                   const struct sk_buff *skb,
                                   unsigned mss_now, int nonagle)
 {
-        return (skb->len < mss_now &&
+        return skb->len < mss_now &&
                 ((nonagle & TCP_NAGLE_CORK) ||
-                 (!nonagle && tp->packets_out && tcp_minshall_check(tp))));
+                 (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
 }
 
 /* Return non-zero if the Nagle test allows this packet to be
@@ -1198,7 +1408,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
          * Nagle can be ignored during F-RTO too (see RFC4138).
          */
         if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
-            (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
+            (TCP_SKB_CB(skb)->flags & TCPHDR_FIN))
                 return 1;
 
         if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
@@ -1241,15 +1451,16 @@ static unsigned int tcp_snd_test(struct sock *sk, struct sk_buff *skb,
         return cwnd_quota;
 }
 
+/* Test if sending is allowed right now. */
 int tcp_may_send_now(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *skb = tcp_send_head(sk);
 
-        return (skb &&
+        return skb &&
                 tcp_snd_test(sk, skb, tcp_current_mss(sk),
                              (tcp_skb_is_last(sk, skb) ?
-                              tp->nonagle : TCP_NAGLE_PUSH)));
+                              tp->nonagle : TCP_NAGLE_PUSH));
 }
 
 /* Trim TSO SKB to LEN bytes, put the remaining data into a new packet
@@ -1260,7 +1471,7 @@ int tcp_may_send_now(struct sock *sk)
  * packet has never been sent out before (and thus is not cloned).
  */
 static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
-                        unsigned int mss_now)
+                        unsigned int mss_now, gfp_t gfp)
 {
         struct sk_buff *buff;
         int nlen = skb->len - len;
@@ -1270,7 +1481,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
         if (skb->len != skb->data_len)
                 return tcp_fragment(sk, skb, len, mss_now);
 
-        buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC);
+        buff = sk_stream_alloc_skb(sk, 0, gfp);
         if (unlikely(buff == NULL))
                 return -ENOMEM;
 
@@ -1286,7 +1497,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 
         /* PSH and FIN should only be set in the second packet. */
         flags = TCP_SKB_CB(skb)->flags;
-        TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+        TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
         TCP_SKB_CB(buff)->flags = flags;
 
         /* This packet was never sent out yet, so no SACK bits. */
@@ -1316,8 +1527,9 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
         struct tcp_sock *tp = tcp_sk(sk);
         const struct inet_connection_sock *icsk = inet_csk(sk);
         u32 send_win, cong_win, limit, in_flight;
+        int win_divisor;
 
-        if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
+        if (TCP_SKB_CB(skb)->flags & TCPHDR_FIN)
                 goto send_now;
 
         if (icsk->icsk_ca_state != TCP_CA_Open)
@@ -1347,13 +1559,14 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
         if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len))
                 goto send_now;
 
-        if (sysctl_tcp_tso_win_divisor) {
+        win_divisor = ACCESS_ONCE(sysctl_tcp_tso_win_divisor);
+        if (win_divisor) {
                 u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
 
                 /* If at least some fraction of a window is available,
                  * just use it.
                  */
-                chunk /= sysctl_tcp_tso_win_divisor;
+                chunk /= win_divisor;
                 if (limit >= chunk)
                         goto send_now;
         } else {
@@ -1377,6 +1590,10 @@ send_now:
 }
 
 /* Create a new MTU probe if we are ready.
+ * MTU probe is regularly attempting to increase the path MTU by
+ * deliberately sending larger packets.  This discovers routing
+ * changes resulting in larger path MTUs.
+ *
  * Returns 0 if we should wait to probe (no cwnd available),
  *         1 if a probe was sent,
  *         -1 otherwise
@@ -1439,7 +1656,7 @@ static int tcp_mtu_probe(struct sock *sk)
 
         TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
         TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
-        TCP_SKB_CB(nskb)->flags = TCPCB_FLAG_ACK;
+        TCP_SKB_CB(nskb)->flags = TCPHDR_ACK;
         TCP_SKB_CB(nskb)->sacked = 0;
         nskb->csum = 0;
         nskb->ip_summed = skb->ip_summed;
@@ -1464,7 +1681,7 @@ static int tcp_mtu_probe(struct sock *sk)
                         sk_wmem_free_skb(sk, skb);
                 } else {
                         TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
-                                                   ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+                                                   ~(TCPHDR_FIN|TCPHDR_PSH);
                         if (!skb_shinfo(skb)->nr_frags) {
                                 skb_pull(skb, copy);
                                 if (skb->ip_summed != CHECKSUM_PARTIAL)
@@ -1564,7 +1781,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                                                     cwnd_quota);
 
                 if (skb->len > limit &&
-                    unlikely(tso_fragment(sk, skb, limit, mss_now)))
+                    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
                         break;
 
                 TCP_SKB_CB(skb)->when = tcp_time_stamp;
@@ -1598,11 +1815,6 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
                                int nonagle)
 {
-        struct sk_buff *skb = tcp_send_head(sk);
-
-        if (!skb)
-                return;
-
         /* If we are closed, the bytes will have to remain here.
          * In time closedown will finish, we empty the write queue and
          * all will be happy.
@@ -1789,6 +2001,7 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
         sk_wmem_free_skb(sk, next_skb);
 }
 
+/* Check if coalescing SKBs is legal. */
 static int tcp_can_collapse(struct sock *sk, struct sk_buff *skb)
 {
         if (tcp_skb_pcount(skb) > 1)
@@ -1807,6 +2020,9 @@ static int tcp_can_collapse(struct sock *sk, struct sk_buff *skb)
         return 1;
 }
 
+/* Collapse packets in the retransmit queue to make to create
+ * less packets on the wire. This is only done on retransmission.
+ */
 static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
                                      int space)
 {
@@ -1816,7 +2032,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 
         if (!sysctl_tcp_retrans_collapse)
                 return;
-        if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)
+        if (TCP_SKB_CB(skb)->flags & TCPHDR_SYN)
                 return;
 
         tcp_for_write_queue_from_safe(skb, tmp, sk) {
@@ -1885,8 +2101,8 @@ 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, tcp_wnd_end(tp))
-            && TCP_SKB_CB(skb)->seq != tp->snd_una)
+        if (!before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp)) &&
+            TCP_SKB_CB(skb)->seq != tp->snd_una)
                 return -EAGAIN;
 
         if (skb->len > cur_mss) {
@@ -1908,7 +2124,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
          * since it is cheap to do so and saves bytes on the network.
          */
         if (skb->len > 0 &&
-            (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+            (TCP_SKB_CB(skb)->flags & TCPHDR_FIN) &&
             tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
                 if (!pskb_trim(skb, 0)) {
                         /* Reuse, even though it does some unnecessary work */
@@ -1956,6 +2172,9 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
         return err;
 }
 
+/* Check if we forward retransmits are possible in the current
+ * window/congestion state.
+ */
 static int tcp_can_forward_retransmit(struct sock *sk)
 {
         const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -2001,6 +2220,9 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
         int mib_idx;
         int fwd_rexmitting = 0;
 
+        if (!tp->packets_out)
+                return;
+
         if (!tp->lost_out)
                 tp->retransmit_high = tp->snd_una;
 
@@ -2094,13 +2316,14 @@ void tcp_send_fin(struct sock *sk)
         mss_now = tcp_current_mss(sk);
 
         if (tcp_send_head(sk) != NULL) {
-                TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN;
+                TCP_SKB_CB(skb)->flags |= TCPHDR_FIN;
                 TCP_SKB_CB(skb)->end_seq++;
                 tp->write_seq++;
         } else {
                 /* Socket is locked, keep trying until memory is available. */
                 for (;;) {
-                        skb = alloc_skb_fclone(MAX_TCP_HEADER, GFP_KERNEL);
+                        skb = alloc_skb_fclone(MAX_TCP_HEADER,
+                                               sk->sk_allocation);
                         if (skb)
                                 break;
                         yield();
@@ -2110,7 +2333,7 @@ void tcp_send_fin(struct sock *sk)
                 skb_reserve(skb, MAX_TCP_HEADER);
                 /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
                 tcp_init_nondata_skb(skb, tp->write_seq,
-                                     TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
+                                     TCPHDR_ACK | TCPHDR_FIN);
                 tcp_queue_skb(sk, skb);
         }
         __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
@@ -2135,7 +2358,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
         /* Reserve space for headers and prepare control bits. */
         skb_reserve(skb, MAX_TCP_HEADER);
         tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
-                             TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
+                             TCPHDR_ACK | TCPHDR_RST);
         /* Send it off. */
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
         if (tcp_transmit_skb(sk, skb, 0, priority))
@@ -2144,7 +2367,8 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
         TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTRSTS);
 }
 
-/* WARNING: This routine must only be called when we have already sent
+/* Send a crossed SYN-ACK during socket establishment.
+ * WARNING: This routine must only be called when we have already sent
  * a SYN packet that crossed the incoming SYN that caused this routine
  * to get called. If this assumption fails then the initial rcv_wnd
  * and rcv_wscale values will not be correct.
@@ -2154,11 +2378,11 @@ int tcp_send_synack(struct sock *sk)
         struct sk_buff *skb;
 
         skb = tcp_write_queue_head(sk);
-        if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)) {
+        if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPHDR_SYN)) {
                 printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
                 return -EFAULT;
         }
-        if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_ACK)) {
+        if (!(TCP_SKB_CB(skb)->flags & TCPHDR_ACK)) {
                 if (skb_cloned(skb)) {
                         struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
                         if (nskb == NULL)
@@ -2172,30 +2396,33 @@ int tcp_send_synack(struct sock *sk)
                         skb = nskb;
                 }
 
-                TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ACK;
+                TCP_SKB_CB(skb)->flags |= TCPHDR_ACK;
                 TCP_ECN_send_synack(tcp_sk(sk), skb);
         }
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
         return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 }
 
-/*
- * Prepare a SYN-ACK.
- */
+/* Prepare a SYN-ACK. */
 struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
-                                struct request_sock *req)
+                                struct request_sock *req,
+                                struct request_values *rvp)
 {
+        struct tcp_out_options opts;
+        struct tcp_extend_values *xvp = tcp_xv(rvp);
         struct inet_request_sock *ireq = inet_rsk(req);
         struct tcp_sock *tp = tcp_sk(sk);
+        const struct tcp_cookie_values *cvp = tp->cookie_values;
         struct tcphdr *th;
-        int tcp_header_size;
-        struct tcp_out_options opts;
         struct sk_buff *skb;
         struct tcp_md5sig_key *md5;
-        __u8 *md5_hash_location;
+        int tcp_header_size;
         int mss;
+        int s_data_desired = 0;
 
-        skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
+        if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired)
+                s_data_desired = cvp->s_data_desired;
+        skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15 + s_data_desired, 1, GFP_ATOMIC);
         if (skb == NULL)
                 return NULL;
 
@@ -2204,7 +2431,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
         skb_dst_set(skb, dst_clone(dst));
 
-        mss = dst_metric(dst, RTAX_ADVMSS);
+        mss = dst_metric_advmss(dst);
         if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
                 mss = tp->rx_opt.user_mss;
 
@@ -2212,13 +2439,20 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
                 __u8 rcv_wscale;
                 /* Set this up on the first call only */
                 req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
+
+                /* limit the window selection if the user enforce a smaller rx buffer */
+                if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
+                    (req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0))
+                        req->window_clamp = tcp_full_space(sk);
+
                 /* tcp_full_space because it is guaranteed to be the first packet */
                 tcp_select_initial_window(tcp_full_space(sk),
                         mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
                         &req->rcv_wnd,
                         &req->window_clamp,
                         ireq->wscale_ok,
-                        &rcv_wscale);
+                        &rcv_wscale,
+                        dst_metric(dst, RTAX_INITRWND));
                 ireq->rcv_wscale = rcv_wscale;
         }
 
@@ -2230,8 +2464,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 #endif
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
         tcp_header_size = tcp_synack_options(sk, req, mss,
-                                             skb, &opts, &md5) +
-                          sizeof(struct tcphdr);
+                                             skb, &opts, &md5, xvp)
+                        + sizeof(*th);
 
         skb_push(skb, tcp_header_size);
         skb_reset_transport_header(skb);
@@ -2247,30 +2481,64 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
          * not even correctly set)
          */
         tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
-                             TCPCB_FLAG_SYN | TCPCB_FLAG_ACK);
+                             TCPHDR_SYN | TCPHDR_ACK);
+
+        if (OPTION_COOKIE_EXTENSION & opts.options) {
+                if (s_data_desired) {
+                        u8 *buf = skb_put(skb, s_data_desired);
+
+                        /* copy data directly from the listening socket. */
+                        memcpy(buf, cvp->s_data_payload, s_data_desired);
+                        TCP_SKB_CB(skb)->end_seq += s_data_desired;
+                }
+
+                if (opts.hash_size > 0) {
+                        __u32 workspace[SHA_WORKSPACE_WORDS];
+                        u32 *mess = &xvp->cookie_bakery[COOKIE_DIGEST_WORDS];
+                        u32 *tail = &mess[COOKIE_MESSAGE_WORDS-1];
+
+                        /* Secret recipe depends on the Timestamp, (future)
+                         * Sequence and Acknowledgment Numbers, Initiator
+                         * Cookie, and others handled by IP variant caller.
+                         */
+                        *tail-- ^= opts.tsval;
+                        *tail-- ^= tcp_rsk(req)->rcv_isn + 1;
+                        *tail-- ^= TCP_SKB_CB(skb)->seq + 1;
+
+                        /* recommended */
+                        *tail-- ^= (((__force u32)th->dest << 16) | (__force u32)th->source);
+                        *tail-- ^= (u32)(unsigned long)cvp; /* per sockopt */
+
+                        sha_transform((__u32 *)&xvp->cookie_bakery[0],
+                                      (char *)mess,
+                                      &workspace[0]);
+                        opts.hash_location =
+                                (__u8 *)&xvp->cookie_bakery[0];
+                }
+        }
+
         th->seq = htonl(TCP_SKB_CB(skb)->seq);
         th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
 
         /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
         th->window = htons(min(req->rcv_wnd, 65535U));
-        tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
+        tcp_options_write((__be32 *)(th + 1), tp, &opts);
         th->doff = (tcp_header_size >> 2);
-        TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
+        TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS, tcp_skb_pcount(skb));
 
 #ifdef CONFIG_TCP_MD5SIG
         /* Okay, we have all we need - do the md5 hash if needed */
         if (md5) {
-                tp->af_specific->calc_md5_hash(md5_hash_location,
+                tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location,
                                                md5, NULL, req, skb);
         }
 #endif
 
         return skb;
 }
+EXPORT_SYMBOL(tcp_make_synack);
 
-/*
- * Do all connect socket setups that can be done AF independent.
- */
+/* Do all connect socket setups that can be done AF independent. */
 static void tcp_connect_init(struct sock *sk)
 {
         struct dst_entry *dst = __sk_dst_get(sk);
@@ -2297,18 +2565,24 @@ static void tcp_connect_init(struct sock *sk)
 
         if (!tp->window_clamp)
                 tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
-        tp->advmss = dst_metric(dst, RTAX_ADVMSS);
+        tp->advmss = dst_metric_advmss(dst);
         if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss)
                 tp->advmss = tp->rx_opt.user_mss;
 
         tcp_initialize_rcv_mss(sk);
 
+        /* limit the window selection if the user enforce a smaller rx buffer */
+        if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
+            (tp->window_clamp > tcp_full_space(sk) || tp->window_clamp == 0))
+                tp->window_clamp = tcp_full_space(sk);
+
         tcp_select_initial_window(tcp_full_space(sk),
                                   tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
                                   &tp->rcv_wnd,
                                   &tp->window_clamp,
                                   sysctl_tcp_window_scaling,
-                                  &rcv_wscale);
+                                  &rcv_wscale,
+                                  dst_metric(dst, RTAX_INITRWND));
 
         tp->rx_opt.rcv_wscale = rcv_wscale;
         tp->rcv_ssthresh = tp->rcv_wnd;
@@ -2329,13 +2603,12 @@ static void tcp_connect_init(struct sock *sk)
         tcp_clear_retrans(tp);
 }
 
-/*
- * Build a SYN and send it off.
- */
+/* Build a SYN and send it off. */
 int tcp_connect(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *buff;
+        int err;
 
         tcp_connect_init(sk);
 
@@ -2347,7 +2620,7 @@ int tcp_connect(struct sock *sk)
         skb_reserve(buff, MAX_TCP_HEADER);
 
         tp->snd_nxt = tp->write_seq;
-        tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN);
+        tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
         TCP_ECN_send_syn(sk, buff);
 
         /* Send it off. */
@@ -2358,7 +2631,9 @@ int tcp_connect(struct sock *sk)
         sk->sk_wmem_queued += buff->truesize;
         sk_mem_charge(sk, buff->truesize);
         tp->packets_out += tcp_skb_pcount(buff);
-        tcp_transmit_skb(sk, buff, 1, GFP_KERNEL);
+        err = tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+        if (err == -ECONNREFUSED)
+                return err;
 
         /* We change tp->snd_nxt after the tcp_transmit_skb() call
          * in order to make this packet get counted in tcpOutSegs.
@@ -2372,6 +2647,7 @@ int tcp_connect(struct sock *sk)
                                   inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
         return 0;
 }
+EXPORT_SYMBOL(tcp_connect);
 
 /* Send out a delayed ack, the caller does the policy checking
  * to see if we should even be here.  See tcp_input.c:tcp_ack_snd_check()
@@ -2453,7 +2729,7 @@ void tcp_send_ack(struct sock *sk)
 
         /* Reserve space for headers and prepare control bits. */
         skb_reserve(buff, MAX_TCP_HEADER);
-        tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPCB_FLAG_ACK);
+        tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK);
 
         /* Send it off, this clears delayed acks for us. */
         TCP_SKB_CB(buff)->when = tcp_time_stamp;
@@ -2487,11 +2763,12 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
          * end to send an ack.  Don't queue or clone SKB, just
          * send it.
          */
-        tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
+        tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK);
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
         return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
 }
 
+/* Initiate keepalive or window probe from timer. */
 int tcp_write_wakeup(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
@@ -2516,13 +2793,13 @@ int tcp_write_wakeup(struct sock *sk)
                 if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
                     skb->len > mss) {
                         seg_size = min(seg_size, mss);
-                        TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+                        TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
                         if (tcp_fragment(sk, skb, seg_size, mss))
                                 return -1;
                 } else if (!tcp_skb_pcount(skb))
                         tcp_set_skb_tso_segs(sk, skb, mss);
 
-                TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+                TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
                 TCP_SKB_CB(skb)->when = tcp_time_stamp;
                 err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
                 if (!err)
@@ -2575,10 +2852,3 @@ void tcp_send_probe0(struct sock *sk)
                                           TCP_RTO_MAX);
         }
 }
-
-EXPORT_SYMBOL(tcp_select_initial_window);
-EXPORT_SYMBOL(tcp_connect);
-EXPORT_SYMBOL(tcp_make_synack);
-EXPORT_SYMBOL(tcp_simple_retransmit);
-EXPORT_SYMBOL(tcp_sync_mss);
-EXPORT_SYMBOL(tcp_mtup_init);