bareudp: Add extack support to bareudp_configure()

Add missing extacks for common configuration errors.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bareudp.c

@@ -609,7 +609,8 @@ static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
 }
 
 static int bareudp_configure(struct net *net, struct net_device *dev,
-			     struct bareudp_conf *conf)
+			     struct bareudp_conf *conf,
+			     struct netlink_ext_ack *extack)
 {
 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
@@ -618,13 +619,17 @@ static int bareudp_configure(struct net *net, struct net_device *dev,
 	bareudp->net = net;
 	bareudp->dev = dev;
 	t = bareudp_find_dev(bn, conf);
-	if (t)
+	if (t) {
+		NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
 		return -EBUSY;
+	}
 
 	if (conf->multi_proto_mode &&
 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
-	     conf->ethertype != htons(ETH_P_IP)))
+	     conf->ethertype != htons(ETH_P_IP))) {
+		NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
 		return -EINVAL;
+	}
 
 	bareudp->port = conf->port;
 	bareudp->ethertype = conf->ethertype;
@@ -671,7 +676,7 @@ static int bareudp_newlink(struct net *net, struct net_device *dev,
 	if (err)
 		return err;
 
-	err = bareudp_configure(net, dev, &conf);
+	err = bareudp_configure(net, dev, &conf, extack);
 	if (err)
 		return err;