[PATCH net] tcp: refresh tcp_mstamp from timers callbacks

[Eric Dumazet <eric.dumazet@gmail.com>]

From: Eric Dumazet <edumazet@google.com>

Only the retransmit timer currently refreshes tcp_mstamp

We should do the same for delayed acks and keepalives.

Even if RFC 7323 does not request it, this is consistent to what linux
did in the past, when TS values were based on jiffies.

Fixes: 385e20706fac ("tcp: use tp->tcp_mstamp in output path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Mike Maloney <maloney@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
---
 net/ipv4/tcp_timer.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 16df6dd44b988a128d97df3a7953437499a216e8..968fda1983762e6d7c078a28ccfcbd9066788daf 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -264,6 +264,7 @@ void tcp_delack_timer_handler(struct sock *sk)
 			icsk->icsk_ack.pingpong = 0;
 			icsk->icsk_ack.ato      = TCP_ATO_MIN;
 		}
+		tcp_mstamp_refresh(tcp_sk(sk));
 		tcp_send_ack(sk);
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKS);
 	}
@@ -632,6 +633,7 @@ static void tcp_keepalive_timer (struct timer_list *t)
 		goto out;
 	}
 
+	tcp_mstamp_refresh(tp);
 	if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) {
 		if (tp->linger2 >= 0) {
 			const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN;