TCP: avoid to send keepalive probes if receiving data
RFC 1122 says the following:
...
Keep-alive packets MUST only be sent when no data or
acknowledgement packets have been received for the
connection within an interval.
...
The acknowledgement packet is reseting the keepalive
timer but the data packet isn't. This patch fixes it by
checking the timestamp of the last received data packet
too when the keepalive timer expires.
Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c732be0..440a5c6 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -517,7 +517,7 @@
struct sock *sk = (struct sock *) data;
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- __u32 elapsed;
+ u32 elapsed;
/* Only process if socket is not in use. */
bh_lock_sock(sk);
@@ -554,7 +554,7 @@
if (tp->packets_out || tcp_send_head(sk))
goto resched;
- elapsed = tcp_time_stamp - tp->rcv_tstamp;
+ elapsed = keepalive_time_elapsed(tp);
if (elapsed >= keepalive_time_when(tp)) {
if (icsk->icsk_probes_out >= keepalive_probes(tp)) {