geneve: Check family when reusing sockets.

When searching for an existing socket to reuse, the address family
is not taken into account - only port number. This means that an
IPv4 socket could be used for IPv6 traffic and vice versa, which
is sure to cause problems when passing packets.

It is not possible to trigger this problem currently because the
only user of Geneve creates just IPv4 sockets. However, that is
likely to change in the near future.
Signed-off-by: NJesse Gross <jesse@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/geneve.c

@@ -65,14 +65,15 @@ static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
 	return (struct genevehdr *)(udp_hdr(skb) + 1);
 }
 
-/* Find geneve socket based on network namespace and UDP port */
-static struct geneve_sock *geneve_find_sock(struct net *net, __be16 port)
+static struct geneve_sock *geneve_find_sock(struct net *net,
+					    sa_family_t family, __be16 port)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_sock *gs;
 
 	list_for_each_entry(gs, &gn->sock_list, list) {
-		if (inet_sk(gs->sock->sk)->inet_sport == port)
+		if (inet_sk(gs->sock->sk)->inet_sport == port &&
+		    inet_sk(gs->sock->sk)->sk.sk_family == family)
 			return gs;
 	}
 
@@ -375,7 +376,7 @@ struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
 
 	mutex_lock(&geneve_mutex);
 
-	gs = geneve_find_sock(net, port);
+	gs = geneve_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port);
 	if (gs) {
 		if (!no_share && gs->rcv == rcv)
 			gs->refcnt++;