tcp: Iterate tb->bhash2 in inet_csk_bind_conflict().

Sockets in bhash are also linked to bhash2, but TIME_WAIT sockets
are linked separately in tb2->deathrow.

Let's replace tb->owners iteration in inet_csk_bind_conflict() with
two iterations over tb2->owners and tb2->deathrow.

This can be done safely under bhash's lock because socket insertion/
deletion in bhash2 happens with bhash's lock held.

Note that twsk_for_each_bound_bhash() will be removed later.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: q2ven

net/ipv4/inet_connection_sock.c

@@ -236,6 +236,14 @@ static bool inet_bhash2_conflict(const struct sock *sk,
 	return false;
 }
 
+#define sk_for_each_bound_bhash(__sk, __tb2, __tb)			\
+	hlist_for_each_entry(__tb2, &(__tb)->bhash2, bhash_node)	\
+		sk_for_each_bound_bhash2(sk2, &(__tb2)->owners)
+
+#define twsk_for_each_bound_bhash(__sk, __tb2, __tb)			\
+	hlist_for_each_entry(__tb2, &(__tb)->bhash2, bhash_node)	\
+		sk_for_each_bound_bhash2(sk2, &(__tb2)->deathrow)
+
 /* This should be called only when the tb and tb2 hashbuckets' locks are held */
 static int inet_csk_bind_conflict(const struct sock *sk,
 				  const struct inet_bind_bucket *tb,
@@ -267,7 +275,15 @@ static int inet_csk_bind_conflict(const struct sock *sk,
 	 * in tb->owners and tb2->owners list belong
 	 * to the same net - the one this bucket belongs to.
 	 */
-	sk_for_each_bound(sk2, &tb->owners) {
+	sk_for_each_bound_bhash(sk2, tb2, tb) {
+		if (!inet_bind_conflict(sk, sk2, uid, relax, reuseport_cb_ok, reuseport_ok))
+			continue;
+
+		if (inet_rcv_saddr_equal(sk, sk2, true))
+			return true;
+	}
+
+	twsk_for_each_bound_bhash(sk2, tb2, tb) {
 		if (!inet_bind_conflict(sk, sk2, uid, relax, reuseport_cb_ok, reuseport_ok))
 			continue;