vxlan: support ndo_fill_metadata_dst also for IPv6

Fill the metadata correctly even when tunneling over IPv6. Also, check that
the provided metadata is of an address family that is supported by the
tunnel.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -2419,9 +2419,30 @@ static int vxlan_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 				  vxlan->cfg.port_max, true);
 	dport = info->key.tp_dst ? : vxlan->cfg.dst_port;
 
-	if (ip_tunnel_info_af(info) == AF_INET)
+	if (ip_tunnel_info_af(info) == AF_INET) {
+		if (!vxlan->vn4_sock)
+			return -EINVAL;
 		return egress_ipv4_tun_info(dev, skb, info, sport, dport);
-	return -EINVAL;
+	} else {
+#if IS_ENABLED(CONFIG_IPV6)
+		struct dst_entry *ndst;
+
+		if (!vxlan->vn6_sock)
+			return -EINVAL;
+		ndst = vxlan6_get_route(vxlan, skb, 0,
+					&info->key.u.ipv6.dst,
+					&info->key.u.ipv6.src);
+		if (IS_ERR(ndst))
+			return PTR_ERR(ndst);
+		dst_release(ndst);
+
+		info->key.tp_src = sport;
+		info->key.tp_dst = dport;
+#else /* !CONFIG_IPV6 */
+		return -EPFNOSUPPORT;
+#endif
+	}
+	return 0;
 }
 
 static const struct net_device_ops vxlan_netdev_ops = {