Subject: [PATCH AUTOSEL 4.14 48/66] bridge: switchdev: Notify about VLAN protocol changes

From: Sasha Levin <[email-masked]>
Date: Tue, 22 Dec 2020 21:22:34 -0500

From: Danielle Ratson <[email-masked]>

[ Upstream commit 22ec19f3aee327806c37c9fa1188741574bc6445 ]

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 <[email-masked]>
Reviewed-by: Petr Machata <[email-masked]>
Acked-by: Nikolay Aleksandrov <[email-masked]>
Signed-off-by: Ido Schimmel <[email-masked]>
Reviewed-by: Ivan Vecera <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 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 d767b79918871..197ea127e29eb 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -50,6 +50,7 @@ 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,
 };
 
@@ -67,6 +68,7 @@ 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 */
 	} u;
 };
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index e24a74884768c..2df788104b5a6 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -723,15 +723,25 @@ EXPORT_SYMBOL_GPL(br_vlan_enabled);
 
 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);
@@ -742,7 +752,6 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 		}
 	}
 
-	oldproto = br->vlan_proto;
 	br->vlan_proto = proto;
 
 	recalculate_group_addr(br);
@@ -758,6 +767,9 @@ 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);
 
-- 
2.27.0