include/linux/sockios.h |    6 ++
 include/linux/tcp.h     |    2 
 net/ipv4/tcp.c          |  113 +++++++++++++++++++++++++++++++++++++++++++++++-
 net/ipv4/tcp_ipv4.c     |   16 ++++--
 4 files changed, 130 insertions(+), 7 deletions(-)

diff --git a/include/linux/sockios.h b/include/linux/sockios.h
index 7997a50..f5c3e41 100644
--- a/include/linux/sockios.h
+++ b/include/linux/sockios.h
@@ -127,6 +127,12 @@
 /* hardware time stamping: parameters in linux/net_tstamp.h */
 #define SIOCSHWTSTAMP   0x89b0
 
+#define SIOCGINSEQ	0x89b1		/* get copied_seq */
+#define SIOCGOUTSEQS	0x89b2		/* get seqs for pending tx pkts */
+#define SIOCSOUTSEQ	0x89b3		/* set write_seq */
+#define SIOCPEEKOUTQ	0x89b4		/* peek output queue */
+#define SIOCFORCEOUTBD	0x89b5		/* force output packet boundary */
+
 /* Device private ioctl calls */
 
 /*
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 531ede8..c0945fe 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -365,6 +365,8 @@ struct tcp_sock {
 	u32	snd_up;		/* Urgent pointer		*/
 
 	u8	keepalive_probes; /* num of allowed keep alive probes	*/
+	u8	wseq_set    : 1;/* Write sequence set via setsockopt	*/
+	u8	force_outbd : 1;/* force packet boundary on next send	*/
 /*
  *      Options received (usually on last packet, some only on SYN packets).
  */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 46febca..3389827 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -464,12 +464,118 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 }
 EXPORT_SYMBOL(tcp_poll);
 
+static int tcp_get_out_seqs(struct sock *sk, u32 __user *p, int size)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	int pos = 0, cnt = size / sizeof(u32);
+
+	if (pos < cnt && put_user(tp->write_seq, &p[pos++]))
+		return -EFAULT;
+
+	skb_queue_reverse_walk(&sk->sk_write_queue, skb) {
+		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
+
+		if (pos < cnt && put_user(tcb->seq, &p[pos++]))
+			return -EFAULT;
+	}
+	return pos * sizeof(u32);
+}
+
+static int tcp_peek_outq(struct sock *sk, void __user *arg, int size)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct iovec iov = { .iov_base = arg, .iov_len = size };
+	struct sk_buff *skb;
+	int copied = 0, err = 0;
+	int outq, skip;
+
+	lock_sock(sk);
+
+	/* XXX: why doesn't SIOCOUTQ[NSD] account for queued fin? */
+	outq = tp->write_seq - tp->snd_una;
+	skb = skb_peek_tail(&sk->sk_write_queue);
+	if (outq && skb)
+		outq -= tcp_hdr(skb)->fin;
+
+	skip = outq - min(size, outq);
+
+	skb_queue_walk(&sk->sk_write_queue, skb) {
+		int off = 0, todo;
+
+		if (skip) {
+			off = min_t(int, skip, skb->len);
+			skip -= off;
+		}
+
+		if (!(todo = skb->len - off))
+			continue;
+
+		if (WARN_ON_ONCE(iov.iov_len < todo)) {
+			err = -EINVAL;
+			break;
+		}
+
+		err = skb_copy_datagram_iovec(skb, off, &iov, todo);
+		if (err)
+			break;
+		copied += todo;
+	}
+
+	release_sock(sk);
+
+	return err ?: copied;
+}
+
 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	int answ;
 
 	switch (cmd) {
+	case SIOCGOUTSEQS: {
+		s32 size;
+
+		if (get_user(size, (s32 __user *)arg))
+			return -EFAULT;
+		if (size < 0)
+			return -EINVAL;
+		return tcp_get_out_seqs(sk, (u32 __user *)arg, size);
+	}
+	case SIOCSOUTSEQ: {
+		u32 seq;
+
+		if (get_user(seq, (u32 __user *)arg))
+			return -EFAULT;
+
+		lock_sock(sk);
+		answ = -EISCONN;
+		if ((sk->sk_socket->state == SS_UNCONNECTED &&
+		     sk->sk_state == TCP_CLOSE) || sk->sk_state == TCP_LISTEN) {
+			tp->write_seq = seq;
+			tp->wseq_set = true;
+			answ = 0;
+		}
+		release_sock(sk);
+		return answ;
+	}
+	case SIOCPEEKOUTQ: {
+		u32 size;
+
+		if (get_user(size, (u32 __user *)arg))
+			return -EFAULT;
+		if ((int)size < size)
+			return -EINVAL;
+		return tcp_peek_outq(sk, (void __user *)arg, size);
+	}
+	case SIOCFORCEOUTBD:
+		lock_sock(sk);
+		tp->force_outbd = true;
+		release_sock(sk);
+		return 0;
+	}
+
+	switch (cmd) {
 	case SIOCINQ:
 		if (sk->sk_state == TCP_LISTEN)
 			return -EINVAL;
@@ -514,6 +620,9 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 		else
 			answ = tp->write_seq - tp->snd_nxt;
 		break;
+	case SIOCGINSEQ:
+		answ = tp->copied_seq;
+		break;
 	default:
 		return -ENOIOCTLCMD;
 	}
@@ -965,7 +1074,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 				copy = max - skb->len;
 			}
 
-			if (copy <= 0) {
+			if (copy <= 0 || unlikely(tp->force_outbd)) {
 new_segment:
 				/* Allocate new segment. If the interface is SG,
 				 * allocate skb fitting to single page.
@@ -979,6 +1088,8 @@ new_segment:
 				if (!skb)
 					goto wait_for_memory;
 
+				tp->force_outbd = false;
+
 				/*
 				 * Check whether we can use HW checksum.
 				 */
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 955b8e6..579234c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -201,7 +201,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		/* Reset inherited state */
 		tp->rx_opt.ts_recent	   = 0;
 		tp->rx_opt.ts_recent_stamp = 0;
-		tp->write_seq		   = 0;
+		if (!tp->wseq_set)
+			tp->write_seq      = 0;
 	}
 
 	if (tcp_death_row.sysctl_tw_recycle &&
@@ -252,12 +253,12 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	sk->sk_gso_type = SKB_GSO_TCPV4;
 	sk_setup_caps(sk, &rt->dst);
 
-	if (!tp->write_seq)
+	if (!tp->write_seq && !tp->wseq_set)
 		tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr,
 							   inet->inet_daddr,
 							   inet->inet_sport,
 							   usin->sin_port);
-
+	tp->wseq_set = false;
 	inet->inet_id = tp->write_seq ^ jiffies;
 
 	err = tcp_connect(sk);
@@ -1252,7 +1253,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 		if (net_ratelimit())
 			syn_flood_warning(skb);
 #ifdef CONFIG_SYN_COOKIES
-		if (sysctl_tcp_syncookies) {
+		if (sysctl_tcp_syncookies && !tp->wseq_set) {
 			want_cookie = 1;
 		} else
 #endif
@@ -1334,7 +1335,10 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	if (!want_cookie || tmp_opt.tstamp_ok)
 		TCP_ECN_create_request(req, tcp_hdr(skb));
 
-	if (want_cookie) {
+	if (unlikely(tp->wseq_set)) {
+		isn = tp->write_seq;
+		tp->wseq_set = false;
+	} else if (want_cookie) {
 		isn = cookie_v4_init_sequence(sk, skb, &req->mss);
 		req->cookie_ts = tmp_opt.tstamp_ok;
 	} else if (!isn) {
@@ -1526,7 +1530,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
 	}
 
 #ifdef CONFIG_SYN_COOKIES
-	if (!th->syn)
+	if (!th->syn && !tcp_sk(sk)->wseq_set)
 		sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
 #endif
 	return sk;