ipv6: add READ_ONCE(sk->sk_bound_dev_if) in INET6_MATCH()

INET6_MATCH() runs without holding a lock on the socket.

We probably need to annotate most reads.

This patch makes INET6_MATCH() an inline function
to ease our changes.

v2: inline function only defined if IS_ENABLED(CONFIG_IPV6)
    Change the name to inet6_match(), this is no longer a macro.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet6_hashtables.h

@@ -103,15 +103,25 @@ struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
 			  const int dif);
 
 int inet6_hash(struct sock *sk);
-#endif /* IS_ENABLED(CONFIG_IPV6) */
 
-#define INET6_MATCH(__sk, __net, __saddr, __daddr, __ports, __dif, __sdif) \
-	(((__sk)->sk_portpair == (__ports))			&&	\
-	 ((__sk)->sk_family == AF_INET6)			&&	\
-	 ipv6_addr_equal(&(__sk)->sk_v6_daddr, (__saddr))		&&	\
-	 ipv6_addr_equal(&(__sk)->sk_v6_rcv_saddr, (__daddr))	&&	\
-	 (((__sk)->sk_bound_dev_if == (__dif))	||			\
-	  ((__sk)->sk_bound_dev_if == (__sdif)))		&&	\
-	 net_eq(sock_net(__sk), (__net)))
+static inline bool inet6_match(struct net *net, const struct sock *sk,
+			       const struct in6_addr *saddr,
+			       const struct in6_addr *daddr,
+			       const __portpair ports,
+			       const int dif, const int sdif)
+{
+	int bound_dev_if;
+
+	if (!net_eq(sock_net(sk), net) ||
+	    sk->sk_family != AF_INET6 ||
+	    sk->sk_portpair != ports ||
+	    !ipv6_addr_equal(&sk->sk_v6_daddr, saddr) ||
+	    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
+		return false;
+
+	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+	return bound_dev_if == dif || bound_dev_if == sdif;
+}
+#endif /* IS_ENABLED(CONFIG_IPV6) */
 
 #endif /* _INET6_HASHTABLES_H */

net/ipv4/inet_hashtables.c

@@ -499,7 +499,7 @@ static bool inet_ehash_lookup_by_sk(struct sock *sk,
 		}
 #if IS_ENABLED(CONFIG_IPV6)
 		else if (sk->sk_family == AF_INET6) {
-			if (unlikely(INET6_MATCH(esk, net,
+			if (unlikely(inet6_match(net, esk,
 						 &sk->sk_v6_daddr,
 						 &sk->sk_v6_rcv_saddr,
 						 ports, dif, sdif))) {

net/ipv6/inet6_hashtables.c

@@ -71,12 +71,12 @@ struct sock *__inet6_lookup_established(struct net *net,
 	sk_nulls_for_each_rcu(sk, node, &head->chain) {
 		if (sk->sk_hash != hash)
 			continue;
-		if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
+		if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
 			continue;
 		if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 			goto out;
 
-		if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
+		if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
 			sock_gen_put(sk);
 			goto begin;
 		}
@@ -268,7 +268,7 @@ static int __inet6_check_established(struct inet_timewait_death_row *death_row,
 		if (sk2->sk_hash != hash)
 			continue;
 
-		if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
+		if (likely(inet6_match(net, sk2, saddr, daddr, ports,
 				       dif, sdif))) {
 			if (sk2->sk_state == TCP_TIME_WAIT) {
 				tw = inet_twsk(sk2);

net/ipv6/udp.c

@@ -1044,7 +1044,7 @@ static struct sock *__udp6_lib_demux_lookup(struct net *net,
 
 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 		if (sk->sk_state == TCP_ESTABLISHED &&
-		    INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
+		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
 			return sk;
 		/* Only check first socket in chain */
 		break;