net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation

In order to properly support VLAN filtering being enabled/disabled on a
bridge, while having other ports being non bridge port members, we need
to support the ndo_vlan_rx_{add,kill}_vid callbacks in order to make
sure the non-bridge ports can continue receiving VLAN tags, even when
the switch is globally configured to do ingress/egress VID checking.

Since we can call dsa_port_vlan_{add,del} with a bridge_dev pointer
NULL, we now need to check that in these two functions.

We specifically deal with two possibly problematic cases:

- creating a bridge VLAN entry while there is an existing VLAN device
  claiming that same VID

- creating a VLAN device while there is an existing bridge VLAN entry
  with that VID

Those are both resolved with returning -EBUSY back to user-space.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/net/dsa/port.c b/net/dsa/port.c
index e9b5b50f8cf1..c011dff523d0 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -291,7 +291,10 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
-	if (br_vlan_enabled(dp->bridge_dev))
+	/* Can be called from dsa_slave_port_obj_add() or
+	 * dsa_slave_vlan_rx_add_vid()
+	 */
+	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
 
 	return 0;
@@ -306,10 +309,13 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 		.vlan = vlan,
 	};
 
-	if (netif_is_bridge_master(vlan->obj.orig_dev))
+	if (vlan->obj.orig_dev && netif_is_bridge_master(vlan->obj.orig_dev))
 		return -EOPNOTSUPP;
 
-	if (br_vlan_enabled(dp->bridge_dev))
+	/* Can be called from dsa_slave_port_obj_del() or
+	 * dsa_slave_vlan_rx_kill_vid()
+	 */
+	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
 
 	return 0;