diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 984ab4a0421ed56153d1833a3742da09147e8e5f..ee528ab3ee823e183b296798492a8ddad1025aa0 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -457,17 +457,34 @@ static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req) static bool tcp_rtx_probe0_timed_out(const struct sock *sk, const struct sk_buff *skb) { + const struct inet_connection_sock *icsk = inet_csk(sk); + u32 user_timeout = READ_ONCE(icsk->icsk_user_timeout); const struct tcp_sock *tp = tcp_sk(sk); - const int timeout = TCP_RTO_MAX * 2; - u32 rcv_delta, rtx_delta; - - rcv_delta = inet_csk(sk)->icsk_timeout - tp->rcv_tstamp; - if (rcv_delta <= timeout) - return false; + int timeout = TCP_RTO_MAX * 2; + u32 rtx_delta; + s32 rcv_delta; rtx_delta = (u32)msecs_to_jiffies(tcp_time_stamp(tp) - (tp->retrans_stamp ?: tcp_skb_timestamp(skb))); + if (user_timeout) { + /* If user application specified a TCP_USER_TIMEOUT, + * it does not want win 0 packets to 'reset the timer' + * while retransmits are not making progress. + */ + if (rtx_delta > user_timeout) + return true; + timeout = min_t(u32, timeout, msecs_to_jiffies(user_timeout)); + } + + /* Note: timer interrupt might have been delayed by at least one jiffy, + * and tp->rcv_tstamp might very well have been written recently. + * rcv_delta can thus be negative. + */ + rcv_delta = icsk->icsk_timeout - tp->rcv_tstamp; + if (rcv_delta <= timeout) + return false; + return rtx_delta > timeout; }