net: bridge: BROPT_FDB_LOCAL_VLAN_0: Skip local FDBs on VLAN creation

When BROPT_FDB_LOCAL_VLAN_0 is enabled, the local FDB entries for the
member ports as well as the bridge itself should not be created per-VLAN,
but instead only on VLAN 0.

Thus when a VLAN is added for a port or the bridge itself, a local FDB
entry with the corresponding address should not be added when in the VLAN-0
mode.

Reviewed-by: Ido Schimmel <[email protected]>
Signed-off-by: Petr Machata <[email protected]>
Acked-by: Nikolay Aleksandrov <[email protected]>
Link: https://patch.msgid.link/bb13ba01d58ed6d5d700e012c519d38ee6806d22.1757004393.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <[email protected]>

Author: pmachata

net/bridge/br_vlan.c

@@ -331,10 +331,12 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags,
 
 	/* Add the dev mac and count the vlan only if it's usable */
 	if (br_vlan_should_use(v)) {
-		err = br_fdb_add_local(br, p, dev->dev_addr, v->vid);
-		if (err) {
-			br_err(br, "failed insert local address into bridge forwarding table\n");
-			goto out_filt;
+		if (!br_opt_get(br, BROPT_FDB_LOCAL_VLAN_0)) {
+			err = br_fdb_add_local(br, p, dev->dev_addr, v->vid);
+			if (err) {
+				br_err(br, "failed insert local address into bridge forwarding table\n");
+				goto out_filt;
+			}
 		}
 		vg->num_vlans++;
 	}