tcp: allow user to create repair socket without window probes

Under rare conditions where repair code may be used it is possible that
window probes are either unnecessary or undesired. If the user knows that
window probes are not wanted or needed this change allows them to skip
sending them when a socket comes out of repair.
Signed-off-by: NStefan Baranoff <sbaranoff@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp.c

@@ -2823,14 +2823,16 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 	case TCP_REPAIR:
 		if (!tcp_can_repair_sock(sk))
 			err = -EPERM;
-		else if (val == 1) {
-			tp->repair = 1;
+		/* 1 for normal repair, 2 for no window probes */
+		else if (val == 1 || val == 2) {
+			tp->repair = val;
 			sk->sk_reuse = SK_FORCE_REUSE;
 			tp->repair_queue = TCP_NO_QUEUE;
 		} else if (val == 0) {
 			tp->repair = 0;
 			sk->sk_reuse = SK_NO_REUSE;
-			tcp_send_window_probe(sk);
+			if (tp->repair == 1)
+				tcp_send_window_probe(sk);
 		} else
 			err = -EINVAL;