3 files changed, 29 insertions, 16 deletions

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
index d846a0ccea8f..63d0c2017ee5 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
@@ -122,11 +122,10 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev,
 	}
 
 	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
-	if (!real_dev || !dev)
+	if (!real_dev) {
+		NL_SET_ERR_MSG_MOD(extack, "link does not exist");
 		return -ENODEV;
-
-	if (!data[IFLA_RMNET_MUX_ID])
-		return -EINVAL;
+	}
 
 	ep = kzalloc(sizeof(*ep), GFP_ATOMIC);
 	if (!ep)
@@ -139,7 +138,7 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev,
 		goto err0;
 
 	port = rmnet_get_port_rtnl(real_dev);
-	err = rmnet_vnd_newlink(mux_id, dev, port, real_dev, ep);
+	err = rmnet_vnd_newlink(mux_id, dev, port, real_dev, ep, extack);
 	if (err)
 		goto err1;
 
@@ -263,12 +262,16 @@ static int rmnet_rtnl_validate(struct nlattr *tb[], struct nlattr *data[],
 {
 	u16 mux_id;
 
-	if (!data || !data[IFLA_RMNET_MUX_ID])
+	if (!data || !data[IFLA_RMNET_MUX_ID]) {
+		NL_SET_ERR_MSG_MOD(extack, "MUX ID not specified");
 		return -EINVAL;
+	}
 
 	mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
-	if (mux_id > (RMNET_MAX_LOGICAL_EP - 1))
+	if (mux_id > (RMNET_MAX_LOGICAL_EP - 1)) {
+		NL_SET_ERR_MSG_MOD(extack, "invalid MUX ID");
 		return -ERANGE;
+	}
 
 	return 0;
 }
@@ -406,14 +409,22 @@ int rmnet_add_bridge(struct net_device *rmnet_dev,
 	/* If there is more than one rmnet dev attached, its probably being
 	 * used for muxing. Skip the briding in that case
 	 */
-	if (port->nr_rmnet_devs > 1)
+	if (port->nr_rmnet_devs > 1) {
+		NL_SET_ERR_MSG_MOD(extack, "more than one rmnet dev attached");
 		return -EINVAL;
+	}
 
-	if (port->rmnet_mode != RMNET_EPMODE_VND)
+	if (port->rmnet_mode != RMNET_EPMODE_VND) {
+		NL_SET_ERR_MSG_MOD(extack, "bridge device already exists");
 		return -EINVAL;
+	}
+
+	if (rmnet_is_real_dev_registered(slave_dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "slave cannot be another rmnet dev");
 
-	if (rmnet_is_real_dev_registered(slave_dev))
 		return -EBUSY;
+	}
 
 	err = rmnet_register_real_device(slave_dev);
 	if (err)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
index 26ad40f19c64..d7c52e398e4a 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c
@@ -222,16 +222,17 @@ void rmnet_vnd_setup(struct net_device *rmnet_dev)
 int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 		      struct rmnet_port *port,
 		      struct net_device *real_dev,
-		      struct rmnet_endpoint *ep)
+		      struct rmnet_endpoint *ep,
+		      struct netlink_ext_ack *extack)
+
 {
 	struct rmnet_priv *priv = netdev_priv(rmnet_dev);
 	int rc;
 
-	if (ep->egress_dev)
-		return -EINVAL;
-
-	if (rmnet_get_endpoint(port, id))
+	if (rmnet_get_endpoint(port, id)) {
+		NL_SET_ERR_MSG_MOD(extack, "MUX ID already exists");
 		return -EBUSY;
+	}
 
 	rmnet_dev->hw_features = NETIF_F_RXCSUM;
 	rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.h
index 14d77c709d4a..4967f3461ed1 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.h
@@ -11,7 +11,8 @@ int rmnet_vnd_do_flow_control(struct net_device *dev, int enable);
 int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 		      struct rmnet_port *port,
 		      struct net_device *real_dev,
-		      struct rmnet_endpoint *ep);
+		      struct rmnet_endpoint *ep,
+		      struct netlink_ext_ack *extack);
 int rmnet_vnd_dellink(u8 id, struct rmnet_port *port,
 		      struct rmnet_endpoint *ep);
 void rmnet_vnd_rx_fixup(struct sk_buff *skb, struct net_device *dev);