tcp: Fix broken repair socket window probe patch

Correct previous bad attempt at allowing sockets to come out of TCP
repair without sending window probes. To avoid changing size of
the repair variable in struct tcp_sock, this lets the decision for
sending probes or not to be made when coming out of repair by
introducing two ways to turn it off.

v2:
* Remove erroneous comment; defines now make behavior clear

Fixes: 70b7ff130224 ("tcp: allow user to create repair socket without window probes")
Signed-off-by: Stefan Baranoff <sbaranoff@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8e5e2ca..ec2186e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2823,16 +2823,17 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 	case TCP_REPAIR:
 		if (!tcp_can_repair_sock(sk))
 			err = -EPERM;
-		/* 1 for normal repair, 2 for no window probes */
-		else if (val == 1 || val == 2) {
-			tp->repair = val;
+		else if (val == TCP_REPAIR_ON) {
+			tp->repair = 1;
 			sk->sk_reuse = SK_FORCE_REUSE;
 			tp->repair_queue = TCP_NO_QUEUE;
-		} else if (val == 0) {
+		} else if (val == TCP_REPAIR_OFF) {
 			tp->repair = 0;
 			sk->sk_reuse = SK_NO_REUSE;
-			if (tp->repair == 1)
-				tcp_send_window_probe(sk);
+			tcp_send_window_probe(sk);
+		} else if (val == TCP_REPAIR_OFF_NO_WP) {
+			tp->repair = 0;
+			sk->sk_reuse = SK_NO_REUSE;
 		} else
 			err = -EINVAL;