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/include/net/tcp.h b/include/net/tcp.h
index 3f87fd8..fb5c66b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1033,6 +1033,14 @@
return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
}
+static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)
+{
+ const struct inet_connection_sock *icsk = &tp->inet_conn;
+
+ return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime,
+ tcp_time_stamp - tp->rcv_tstamp);
+}
+
static inline int tcp_fin_time(const struct sock *sk)
{
int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;