net: dsa: propagate extack to .port_vlan_filtering

Some drivers can't dynamically change the VLAN filtering option, or
impose some restrictions, it would be nice to propagate this info
through netlink instead of printing it to a kernel log that might never
be read. Also netlink extack includes the module that emitted the
message, which means that it's easier to figure out which ones are
driver-generated errors as opposed to command misuse.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 20 insertions, 10 deletions

diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 17a9f82db937..e9d1e76c42ba 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -170,7 +170,8 @@ int dsa_port_lag_change(struct dsa_port *dp,
 int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag_dev,
 		      struct netdev_lag_upper_info *uinfo);
 void dsa_port_lag_leave(struct dsa_port *dp, struct net_device *lag_dev);
-int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering);
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct netlink_ext_ack *extack);
 bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
 int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock);
 int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 03ecefe1064a..14a1d0d77657 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -294,7 +294,8 @@ void dsa_port_lag_leave(struct dsa_port *dp, struct net_device *lag)
 
 /* Must be called under rcu_read_lock() */
 static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
-					      bool vlan_filtering)
+					      bool vlan_filtering,
+					      struct netlink_ext_ack *extack)
 {
 	struct dsa_switch *ds = dp->ds;
 	int err, i;
@@ -324,8 +325,8 @@ static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
 			 */
 			err = br_vlan_get_info(br, vid, &br_info);
 			if (err == 0) {
-				dev_err(ds->dev, "Must remove upper %s first\n",
-					upper_dev->name);
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Must first remove VLAN uppers having VIDs also present in bridge");
 				return false;
 			}
 		}
@@ -351,14 +352,16 @@ static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
 		if (other_bridge == dp->bridge_dev)
 			continue;
 		if (br_vlan_enabled(other_bridge) != vlan_filtering) {
-			dev_err(ds->dev, "VLAN filtering is a global setting\n");
+			NL_SET_ERR_MSG_MOD(extack,
+					   "VLAN filtering is a global setting");
 			return false;
 		}
 	}
 	return true;
 }
 
-int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering)
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct netlink_ext_ack *extack)
 {
 	struct dsa_switch *ds = dp->ds;
 	bool apply;
@@ -372,7 +375,7 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering)
 	 * dsa_slave_switchdev_event().
 	 */
 	rcu_read_lock();
-	apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering);
+	apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering, extack);
 	rcu_read_unlock();
 	if (!apply)
 		return -EINVAL;
@@ -380,7 +383,8 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering)
 	if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
 		return 0;
 
-	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering);
+	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering,
+					   extack);
 	if (err)
 		return err;
 
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 9ec487b63e13..5ecb43a1b6e0 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -286,7 +286,8 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
 		ret = dsa_port_set_state(dp, attr->u.stp_state);
 		break;
 	case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
-		ret = dsa_port_vlan_filtering(dp, attr->u.vlan_filtering);
+		ret = dsa_port_vlan_filtering(dp, attr->u.vlan_filtering,
+					      extack);
 		break;
 	case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
 		ret = dsa_port_ageing_time(dp, attr->u.ageing_time);
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index c82d201181a5..db2a9b221988 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -106,6 +106,7 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 {
 	bool unset_vlan_filtering = br_vlan_enabled(info->br);
 	struct dsa_switch_tree *dst = ds->dst;
+	struct netlink_ext_ack extack = {0};
 	int err, i;
 
 	if (dst->index == info->tree_index && ds->index == info->sw_index &&
@@ -137,7 +138,10 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
 	}
 	if (unset_vlan_filtering) {
 		err = dsa_port_vlan_filtering(dsa_to_port(ds, info->port),
-					      false);
+					      false, &extack);
+		if (extack._msg)
+			dev_err(ds->dev, "port %d: %s\n", info->port,
+				extack._msg);
 		if (err && err != EOPNOTSUPP)
 			return err;
 	}