net: check UDP tunnel RX port offload feature before calling tunnel ndo ndo

If NETIF_F_RX_UDP_TUNNEL_PORT was disabled on a given netdevice, skip
the tunnel offload ndo call during tunnel port creation and deletion.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/udp_tunnel.c

@@ -82,7 +82,8 @@ void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
 	struct sock *sk = sock->sk;
 	struct udp_tunnel_info ti;
 
-	if (!dev->netdev_ops->ndo_udp_tunnel_add)
+	if (!dev->netdev_ops->ndo_udp_tunnel_add ||
+	    !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 		return;
 
 	ti.type = type;
@@ -109,6 +110,8 @@ void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
 	for_each_netdev_rcu(net, dev) {
 		if (!dev->netdev_ops->ndo_udp_tunnel_add)
 			continue;
+		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
+			continue;
 		dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
 	}
 	rcu_read_unlock();
@@ -131,6 +134,8 @@ void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
 	for_each_netdev_rcu(net, dev) {
 		if (!dev->netdev_ops->ndo_udp_tunnel_del)
 			continue;
+		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
+			continue;
 		dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
 	}
 	rcu_read_unlock();