1 files changed, 38 insertions, 13 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 3b3611729928..7fdf222a0bdf 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -22,6 +22,35 @@
 #include <linux/gfp.h>
 #include <net/tcp.h>
 
+static u32 tcp_retransmit_stamp(const struct sock *sk)
+{
+	u32 start_ts = tcp_sk(sk)->retrans_stamp;
+
+	if (unlikely(!start_ts)) {
+		struct sk_buff *head = tcp_rtx_queue_head(sk);
+
+		if (!head)
+			return 0;
+		start_ts = tcp_skb_timestamp(head);
+	}
+	return start_ts;
+}
+
+static u32 tcp_clamp_rto_to_user_timeout(const struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	u32 elapsed, start_ts;
+
+	start_ts = tcp_retransmit_stamp(sk);
+	if (!icsk->icsk_user_timeout || !start_ts)
+		return icsk->icsk_rto;
+	elapsed = tcp_time_stamp(tcp_sk(sk)) - start_ts;
+	if (elapsed >= icsk->icsk_user_timeout)
+		return 1; /* user timeout has passed; fire ASAP */
+	else
+		return min_t(u32, icsk->icsk_rto, msecs_to_jiffies(icsk->icsk_user_timeout - elapsed));
+}
+
 /**
  *  tcp_write_err() - close socket and save error info
  *  @sk:  The socket the error has appeared on.
@@ -166,14 +195,9 @@ static bool retransmits_timed_out(struct sock *sk,
 	if (!inet_csk(sk)->icsk_retransmits)
 		return false;
 
-	start_ts = tcp_sk(sk)->retrans_stamp;
-	if (unlikely(!start_ts)) {
-		struct sk_buff *head = tcp_rtx_queue_head(sk);
-
-		if (!head)
-			return false;
-		start_ts = tcp_skb_timestamp(head);
-	}
+	start_ts = tcp_retransmit_stamp(sk);
+	if (!start_ts)
+		return false;
 
 	if (likely(timeout == 0)) {
 		linear_backoff_thresh = ilog2(TCP_RTO_MAX/rto_base);
@@ -183,8 +207,9 @@ static bool retransmits_timed_out(struct sock *sk,
 		else
 			timeout = ((2 << linear_backoff_thresh) - 1) * rto_base +
 				(boundary - linear_backoff_thresh) * TCP_RTO_MAX;
+		timeout = jiffies_to_msecs(timeout);
 	}
-	return (tcp_time_stamp(tcp_sk(sk)) - start_ts) >= jiffies_to_msecs(timeout);
+	return (tcp_time_stamp(tcp_sk(sk)) - start_ts) >= timeout;
 }
 
 /* A write timeout has occurred. Process the after effects. */
@@ -337,8 +362,7 @@ static void tcp_probe_timer(struct sock *sk)
 	if (!start_ts)
 		skb->skb_mstamp = tp->tcp_mstamp;
 	else if (icsk->icsk_user_timeout &&
-		 (s32)(tcp_time_stamp(tp) - start_ts) >
-		 jiffies_to_msecs(icsk->icsk_user_timeout))
+		 (s32)(tcp_time_stamp(tp) - start_ts) > icsk->icsk_user_timeout)
 		goto abort;
 
 	max_probes = sock_net(sk)->ipv4.sysctl_tcp_retries2;
@@ -535,7 +559,8 @@ out_reset_timer:
 		/* Use normal (exponential) backoff */
 		icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
 	}
-	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX);
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+				  tcp_clamp_rto_to_user_timeout(sk), TCP_RTO_MAX);
 	if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1 + 1, 0))
 		__sk_dst_reset(sk);
 
@@ -672,7 +697,7 @@ static void tcp_keepalive_timer (struct timer_list *t)
 		 * to determine when to timeout instead.
 		 */
 		if ((icsk->icsk_user_timeout != 0 &&
-		    elapsed >= icsk->icsk_user_timeout &&
+		    elapsed >= msecs_to_jiffies(icsk->icsk_user_timeout) &&
 		    icsk->icsk_probes_out > 0) ||
 		    (icsk->icsk_user_timeout == 0 &&
 		    icsk->icsk_probes_out >= keepalive_probes(tp))) {