[PATCH net-next 7/9] bridge: switchdev: Notify about VLAN protocol changes

[Ido Schimmel <idosch@idosch.org>]

From: Danielle Ratson <danieller@nvidia.com>

Drivers that support bridge offload need to be notified about changes to
the bridge's VLAN protocol so that they could react accordingly and
potentially veto the change.

Add a new switchdev attribute to communicate the change to drivers.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 include/net/switchdev.h |  2 ++
 net/bridge/br_vlan.c    | 16 ++++++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 53e8b4994296..99cd538d6519 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -38,6 +38,7 @@ enum switchdev_attr_id {
 	SWITCHDEV_ATTR_ID_PORT_MROUTER,
 	SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
 	SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING,
+	SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL,
 	SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED,
 	SWITCHDEV_ATTR_ID_BRIDGE_MROUTER,
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
@@ -58,6 +59,7 @@ struct switchdev_attr {
 		bool mrouter;				/* PORT_MROUTER */
 		clock_t ageing_time;			/* BRIDGE_AGEING_TIME */
 		bool vlan_filtering;			/* BRIDGE_VLAN_FILTERING */
+		u16 vlan_protocol;			/* BRIDGE_VLAN_PROTOCOL */
 		bool mc_disabled;			/* MC_DISABLED */
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 		u8 mrp_port_state;			/* MRP_PORT_STATE */
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 11f54a7c0d1d..d07008678d32 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -854,15 +854,25 @@ EXPORT_SYMBOL_GPL(br_vlan_get_proto);
 
 int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 {
+	struct switchdev_attr attr = {
+		.orig_dev = br->dev,
+		.id = SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL,
+		.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP,
+		.u.vlan_protocol = ntohs(proto),
+	};
 	int err = 0;
 	struct net_bridge_port *p;
 	struct net_bridge_vlan *vlan;
 	struct net_bridge_vlan_group *vg;
-	__be16 oldproto;
+	__be16 oldproto = br->vlan_proto;
 
 	if (br->vlan_proto == proto)
 		return 0;
 
+	err = switchdev_port_attr_set(br->dev, &attr);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
 	/* Add VLANs for the new proto to the device filter. */
 	list_for_each_entry(p, &br->port_list, list) {
 		vg = nbp_vlan_group(p);
@@ -873,7 +883,6 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 		}
 	}
 
-	oldproto = br->vlan_proto;
 	br->vlan_proto = proto;
 
 	recalculate_group_addr(br);
@@ -889,6 +898,9 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 	return 0;
 
 err_filt:
+	attr.u.vlan_protocol = ntohs(oldproto);
+	switchdev_port_attr_set(br->dev, &attr);
+
 	list_for_each_entry_continue_reverse(vlan, &vg->vlan_list, vlist)
 		vlan_vid_del(p->dev, proto, vlan->vid);
 
-- 
2.28.0