Re: [PATCH net v3] net: bridge: mst: Check vlan state for egress decision

[Nikolay Aleksandrov <razor@blackwall.org>]

On 12/07/2024 04:31, Elliot Ayrey wrote:
> If a port is blocking in the common instance but forwarding in an MST
> instance, traffic egressing the bridge will be dropped because the
> state of the common instance is overriding that of the MST instance.
> 
> Fix this by skipping the port state check in MST mode to allow
> checking the vlan state via br_allowed_egress(). This is similar to
> what happens in br_handle_frame_finish() when checking ingress
> traffic, which was introduced in the change below.
> 
> Fixes: ec7328b59176 ("net: bridge: mst: Multiple Spanning Tree (MST) mode")
> Signed-off-by: Elliot Ayrey <elliot.ayrey@alliedtelesis.co.nz>
> ---
> 
> v3:
>   - Properly reference port state to fix compile error
> v2: https://lore.kernel.org/all/20240711045926.756958-1-elliot.ayrey@alliedtelesis.co.nz/
>   - Restructure the MST mode check to make it read better
> v1: https://lore.kernel.org/all/20240705030041.1248472-1-elliot.ayrey@alliedtelesis.co.nz/
> 
>  net/bridge/br_forward.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
> index d97064d460dc..e19b583ff2c6 100644
> --- a/net/bridge/br_forward.c
> +++ b/net/bridge/br_forward.c
> @@ -25,8 +25,8 @@ static inline int should_deliver(const struct net_bridge_port *p,
>  
>  	vg = nbp_vlan_group_rcu(p);
>  	return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
> -		p->state == BR_STATE_FORWARDING && br_allowed_egress(vg, skb) &&
> -		nbp_switchdev_allowed_egress(p, skb) &&
> +		(br_mst_is_enabled(p->br) || p->state == BR_STATE_FORWARDING) &&
> +		br_allowed_egress(vg, skb) && nbp_switchdev_allowed_egress(p, skb) &&
>  		!br_skb_isolated(p, skb);
>  }
>  

Acked-by: Nikolay Aleksandrov <razor@blackwall.org>