1 files changed, 77 insertions, 34 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index e911e6c523e..fc04711e80c 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -32,17 +32,6 @@ int sysctl_tcp_retries2 __read_mostly = TCP_RETR2;
 int sysctl_tcp_orphan_retries __read_mostly;
 int sysctl_tcp_thin_linear_timeouts __read_mostly;
 
-static void tcp_write_timer(unsigned long);
-static void tcp_delack_timer(unsigned long);
-static void tcp_keepalive_timer (unsigned long data);
-
-void tcp_init_xmit_timers(struct sock *sk)
-{
-	inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,
-				  &tcp_keepalive_timer);
-}
-EXPORT_SYMBOL(tcp_init_xmit_timers);
-
 static void tcp_write_err(struct sock *sk)
 {
 	sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
@@ -205,21 +194,11 @@ static int tcp_write_timeout(struct sock *sk)
 	return 0;
 }
 
-static void tcp_delack_timer(unsigned long data)
+void tcp_delack_timer_handler(struct sock *sk)
 {
-	struct sock *sk = (struct sock *)data;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
 
-	bh_lock_sock(sk);
-	if (sock_owned_by_user(sk)) {
-		/* Try again later. */
-		icsk->icsk_ack.blocked = 1;
-		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
-		sk_reset_timer(sk, &icsk->icsk_delack_timer, jiffies + TCP_DELACK_MIN);
-		goto out_unlock;
-	}
-
 	sk_mem_reclaim_partial(sk);
 
 	if (sk->sk_state == TCP_CLOSE || !(icsk->icsk_ack.pending & ICSK_ACK_TIMER))
@@ -260,7 +239,22 @@ static void tcp_delack_timer(unsigned long data)
 out:
 	if (sk_under_memory_pressure(sk))
 		sk_mem_reclaim(sk);
-out_unlock:
+}
+
+static void tcp_delack_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock *)data;
+
+	bh_lock_sock(sk);
+	if (!sock_owned_by_user(sk)) {
+		tcp_delack_timer_handler(sk);
+	} else {
+		inet_csk(sk)->icsk_ack.blocked = 1;
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
+		/* deleguate our work to tcp_release_cb() */
+		if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+			sock_hold(sk);
+	}
 	bh_unlock_sock(sk);
 	sock_put(sk);
 }
@@ -311,6 +305,35 @@ static void tcp_probe_timer(struct sock *sk)
 }
 
 /*
+ *	Timer for Fast Open socket to retransmit SYNACK. Note that the
+ *	sk here is the child socket, not the parent (listener) socket.
+ */
+static void tcp_fastopen_synack_timer(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int max_retries = icsk->icsk_syn_retries ? :
+	    sysctl_tcp_synack_retries + 1; /* add one more retry for fastopen */
+	struct request_sock *req;
+
+	req = tcp_sk(sk)->fastopen_rsk;
+	req->rsk_ops->syn_ack_timeout(sk, req);
+
+	if (req->retrans >= max_retries) {
+		tcp_write_err(sk);
+		return;
+	}
+	/* XXX (TFO) - Unlike regular SYN-ACK retransmit, we ignore error
+	 * returned from rtx_syn_ack() to make it more persistent like
+	 * regular retransmit because if the child socket has been accepted
+	 * it's not good to give up too easily.
+	 */
+	req->rsk_ops->rtx_syn_ack(sk, req, NULL);
+	req->retrans++;
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+			  TCP_TIMEOUT_INIT << req->retrans, TCP_RTO_MAX);
+}
+
+/*
  *	The TCP retransmit timer.
  */
 
@@ -323,7 +346,15 @@ void tcp_retransmit_timer(struct sock *sk)
 		tcp_resume_early_retransmit(sk);
 		return;
 	}
-
+	if (tp->fastopen_rsk) {
+		BUG_ON(sk->sk_state != TCP_SYN_RECV &&
+		    sk->sk_state != TCP_FIN_WAIT1);
+		tcp_fastopen_synack_timer(sk);
+		/* Before we receive ACK to our SYN-ACK don't retransmit
+		 * anything else (e.g., data or FIN segments).
+		 */
+		return;
+	}
 	if (!tp->packets_out)
 		goto out;
 
@@ -450,19 +481,11 @@ out_reset_timer:
 out:;
 }
 
-static void tcp_write_timer(unsigned long data)
+void tcp_write_timer_handler(struct sock *sk)
 {
-	struct sock *sk = (struct sock *)data;
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	int event;
 
-	bh_lock_sock(sk);
-	if (sock_owned_by_user(sk)) {
-		/* Try again later */
-		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + (HZ / 20));
-		goto out_unlock;
-	}
-
 	if (sk->sk_state == TCP_CLOSE || !icsk->icsk_pending)
 		goto out;
 
@@ -485,7 +508,20 @@ static void tcp_write_timer(unsigned long data)
 
 out:
 	sk_mem_reclaim(sk);
-out_unlock:
+}
+
+static void tcp_write_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock *)data;
+
+	bh_lock_sock(sk);
+	if (!sock_owned_by_user(sk)) {
+		tcp_write_timer_handler(sk);
+	} else {
+		/* deleguate our work to tcp_release_cb() */
+		if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+			sock_hold(sk);
+	}
 	bh_unlock_sock(sk);
 	sock_put(sk);
 }
@@ -602,3 +638,10 @@ out:
 	bh_unlock_sock(sk);
 	sock_put(sk);
 }
+
+void tcp_init_xmit_timers(struct sock *sk)
+{
+	inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,
+				  &tcp_keepalive_timer);
+}
+EXPORT_SYMBOL(tcp_init_xmit_timers);