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Diffstat (limited to 'net/ipv4/tcp_timer.c')
-rw-r--r--net/ipv4/tcp_timer.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index b774a03bd1d..fc04711e80c 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -305,6 +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.
*/
@@ -317,7 +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;