tcp: reinitialize MTU probing when setting MSS in a TCP repair (15e56515) · Commits · 戴 / test

MTU probing initialization occurred only at connect() and at SYN or SYN-ACK reception, but the former sets MSS to either the default or the user set value (through TCP_MAXSEG sockopt) and the latter never happens with repaired sockets. The result was that, with MTU probing enabled and unless TCP_MAXSEG sockopt was used before connect(), probing would be stuck at tcp_base_mss value until tcp_probe_interval seconds have passed. Signed-off-by:

Douglas Caetano dos Santos <douglascs@taghos.com.br> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2381,9 +2381,10 @@ static int tcp_repair_set_window(struct tcp_sock tp, char __user optbuf, int l
		return 0;
		}

		static int tcp_repair_options_est(struct tcp_sock *tp,
		static int tcp_repair_options_est(struct sock *sk,
		struct tcp_repair_opt __user *optbuf, unsigned int len)
		{
		struct tcp_sock *tp = tcp_sk(sk);
		struct tcp_repair_opt opt;

		while (len >= sizeof(opt)) {
		@@ -2396,6 +2397,7 @@ static int tcp_repair_options_est(struct tcp_sock *tp,
		switch (opt.opt_code) {
		case TCPOPT_MSS:
		tp->rx_opt.mss_clamp = opt.opt_val;
		tcp_mtup_init(sk);
		break;
		case TCPOPT_WINDOW:
		{
		@@ -2555,7 +2557,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
		if (!tp->repair)
		err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
		err = tcp_repair_options_est(tp,
		err = tcp_repair_options_est(sk,
		(struct tcp_repair_opt __user *)optval,
		optlen);
		else

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