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

[Ivan Vecera <ivecera@redhat.com>]

On Sun, 29 Nov 2020 14:54:05 +0200
Ido Schimmel <idosch@idosch.org> wrote:

> 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);
>  

Reviewed-by: Ivan Vecera <ivecera@redhat.com>