Re: [PATCH v5 net-next 09/15] net: bridge: mst: Add helper to query a port's MST state

[Vladimir Oltean <olteanv@gmail.com>]

On Wed, Mar 16, 2022 at 04:08:51PM +0100, Tobias Waldekranz wrote:
> This is useful for switchdev drivers who are offloading MST states
> into hardware. As an example, a driver may wish to flush the FDB for a
> port when it transitions from forwarding to blocking - which means
> that the previous state must be discoverable.
> 
> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

>  include/linux/if_bridge.h |  6 ++++++
>  net/bridge/br_mst.c       | 25 +++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 4efd5540279a..d62ef428e3aa 100644
> --- a/include/linux/if_bridge.h
> +++ b/include/linux/if_bridge.h
> @@ -121,6 +121,7 @@ int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
>  			 struct bridge_vlan_info *p_vinfo);
>  bool br_mst_enabled(const struct net_device *dev);
>  int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids);
> +int br_mst_get_state(const struct net_device *dev, u16 msti, u8 *state);
>  #else
>  static inline bool br_vlan_enabled(const struct net_device *dev)
>  {
> @@ -164,6 +165,11 @@ static inline int br_mst_get_info(const struct net_device *dev, u16 msti,
>  {
>  	return -EINVAL;
>  }
> +static inline int br_mst_get_state(const struct net_device *dev, u16 msti,
> +				   u8 *state)
> +{
> +	return -EINVAL;
> +}
>  #endif
>  
>  #if IS_ENABLED(CONFIG_BRIDGE)
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 830a5746479f..ee680adcee17 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -48,6 +48,31 @@ int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
>  }
>  EXPORT_SYMBOL_GPL(br_mst_get_info);
>  
> +int br_mst_get_state(const struct net_device *dev, u16 msti, u8 *state)
> +{
> +	const struct net_bridge_port *p = NULL;
> +	const struct net_bridge_vlan_group *vg;
> +	const struct net_bridge_vlan *v;
> +
> +	ASSERT_RTNL();
> +
> +	p = br_port_get_check_rtnl(dev);
> +	if (!p || !br_opt_get(p->br, BROPT_MST_ENABLED))
> +		return -EINVAL;
> +
> +	vg = nbp_vlan_group(p);
> +
> +	list_for_each_entry(v, &vg->vlan_list, vlist) {
> +		if (v->brvlan->msti == msti) {
> +			*state = v->state;
> +			return 0;
> +		}
> +	}
> +
> +	return -ENOENT;
> +}
> +EXPORT_SYMBOL_GPL(br_mst_get_state);
> +
>  static void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
>  				  u8 state)
>  {
> -- 
> 2.25.1
>