From 344db93ae3ee69fc137bd6ed89a8ff1bf5b0db08 Mon Sep 17 00:00:00 2001 From: Enke Chen Date: Fri, 22 Jan 2021 11:13:06 -0800 Subject: tcp: make TCP_USER_TIMEOUT accurate for zero window probes The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the timer has backoff with a max interval of about two minutes, the actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes. In this patch the TCP_USER_TIMEOUT is made more accurate by taking it into account when computing the timer value for the 0-window probes. This patch is similar to and builds on top of the one that made TCP_USER_TIMEOUT accurate for RTOs in commit b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy"). Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT") Signed-off-by: Enke Chen Reviewed-by: Neal Cardwell Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20210122191306.GA99540@localhost.localdomain Signed-off-by: Jakub Kicinski --- include/net/tcp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/net/tcp.h b/include/net/tcp.h index 78d13c88720f..ca7e2c6cc663 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -630,6 +630,7 @@ static inline void tcp_clear_xmit_timers(struct sock *sk) unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); unsigned int tcp_current_mss(struct sock *sk); +u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); /* Bound MSS / TSO packet size with the half of the window */ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) -- cgit v1.2.3