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>
This commit is contained in:
Flavio Leitner
2010-04-26 18:33:27 +00:00
committed by David S. Miller
parent dcdca2c49b
commit 6c37e5de45
3 changed files with 11 additions and 3 deletions

View File

@@ -517,7 +517,7 @@ static void tcp_keepalive_timer (unsigned long data)
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 @@ static void tcp_keepalive_timer (unsigned long data)
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)) {