1 files changed, 30 insertions, 12 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index f75069883f2b..685ba53df2d1 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -479,7 +479,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 
 	snum = ntohs(addr->sin_port);
 	err = -EACCES;
-	if (snum && snum < PROT_SOCK &&
+	if (snum && snum < inet_prot_sock(net) &&
 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
 		goto out;
 
@@ -570,19 +570,30 @@ static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
  *	TCP 'magic' in here.
  */
 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
-			  int addr_len, int flags)
+			  int addr_len, int flags, int is_sendmsg)
 {
 	struct sock *sk = sock->sk;
 	int err;
 	long timeo;
 
-	if (addr_len < sizeof(uaddr->sa_family))
-		return -EINVAL;
+	/*
+	 * uaddr can be NULL and addr_len can be 0 if:
+	 * sk is a TCP fastopen active socket and
+	 * TCP_FASTOPEN_CONNECT sockopt is set and
+	 * we already have a valid cookie for this socket.
+	 * In this case, user can call write() after connect().
+	 * write() will invoke tcp_sendmsg_fastopen() which calls
+	 * __inet_stream_connect().
+	 */
+	if (uaddr) {
+		if (addr_len < sizeof(uaddr->sa_family))
+			return -EINVAL;
 
-	if (uaddr->sa_family == AF_UNSPEC) {
-		err = sk->sk_prot->disconnect(sk, flags);
-		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
-		goto out;
+		if (uaddr->sa_family == AF_UNSPEC) {
+			err = sk->sk_prot->disconnect(sk, flags);
+			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
+			goto out;
+		}
 	}
 
 	switch (sock->state) {
@@ -593,7 +604,10 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 		err = -EISCONN;
 		goto out;
 	case SS_CONNECTING:
-		err = -EALREADY;
+		if (inet_sk(sk)->defer_connect)
+			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
+		else
+			err = -EALREADY;
 		/* Fall out of switch with err, set for this state */
 		break;
 	case SS_UNCONNECTED:
@@ -607,6 +621,9 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 
 		sock->state = SS_CONNECTING;
 
+		if (!err && inet_sk(sk)->defer_connect)
+			goto out;
+
 		/* Just entered SS_CONNECTING state; the only
 		 * difference is that return value in non-blocking
 		 * case is EINPROGRESS, rather than EALREADY.
@@ -662,7 +679,7 @@ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	int err;
 
 	lock_sock(sock->sk);
-	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
+	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
 	release_sock(sock->sk);
 	return err;
 }
@@ -1700,6 +1717,9 @@ static __net_init int inet_init_net(struct net *net)
 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
 	net->ipv4.sysctl_ip_dynaddr = 0;
 	net->ipv4.sysctl_ip_early_demux = 1;
+#ifdef CONFIG_SYSCTL
+	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
+#endif
 
 	return 0;
 }
@@ -1831,8 +1851,6 @@ static int __init inet_init(void)
 
 	ip_init();
 
-	tcp_v4_init();
-
 	/* Setup TCP slab cache for open requests. */
 	tcp_init();