@@ -314,6 +314,7 @@ struct tcp_sock {
u32 snd_sml; /* Last byte of the most recently transmitted small packet */
u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
+ u32 lrcvtime; /* timestamp of last received data packet (for keepalives) */
/* Data for direct copy to user */
struct {
@@ -5391,6 +5391,8 @@ no_ack:
__kfree_skb(skb);
else
sk->sk_data_ready(sk, 0);
+
+ tp->lrcvtime = tcp_time_stamp;
return 0;
}
}
@@ -5421,6 +5423,7 @@ step5:
tcp_data_snd_check(sk);
tcp_ack_snd_check(sk);
+ tp->lrcvtime = tcp_time_stamp;
return 0;
csum_error:
@@ -554,6 +554,14 @@ static void tcp_keepalive_timer (unsigned long data)
if (tp->packets_out || tcp_send_head(sk))
goto resched;
+ elapsed = tcp_time_stamp - tp->lrcvtime;
+
+ /* receiving data means alive */
+ if (elapsed < keepalive_time_when(tp)) {
+ elapsed = keepalive_time_when(tp) - elapsed;
+ goto resched;
+ }
+
elapsed = tcp_time_stamp - tp->rcv_tstamp;
if (elapsed >= keepalive_time_when(tp)) {
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. ... Fix this by storing the timestamp of last received data packet and checking for it when the keepalive timer expires. Signed-off-by: Flavio Leitner <fleitner@redhat.com> --- include/linux/tcp.h | 1 + net/ipv4/tcp_input.c | 3 +++ net/ipv4/tcp_timer.c | 8 ++++++++ 3 files changed, 12 insertions(+), 0 deletions(-)