From 54a378f43425085d0684679d99735696b69165bc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 7 Feb 2025 15:28:29 +0000 Subject: tcp: add the ability to control max RTO Currently, TCP stack uses a constant (120 seconds) to limit the RTO value exponential growth. Some applications want to set a lower value. Add TCP_RTO_MAX_MS socket option to set a value (in ms) between 1 and 120 seconds. It is discouraged to change the socket rto max on a live socket, as it might lead to unexpected disconnects. Following patch is adding a netns sysctl to control the default value at socket creation time. Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Reviewed-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni --- net/ipv4/tcp_ipv4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index e065f7097611..06fb0123d2d6 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -458,7 +458,7 @@ void tcp_ld_RTO_revert(struct sock *sk, u32 seq) icsk->icsk_backoff--; icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT; - icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); + icsk->icsk_rto = inet_csk_rto_backoff(icsk, tcp_rto_max(sk)); tcp_mstamp_refresh(tp); delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb)); -- cgit v1.2.3