Re: [PATCH net v2] net: bridge: mst: Check vlan state for egress decision

From: Elliot Ayrey
Date: Thu Jul 11 2024 - 20:19:06 EST




On Thu, 11 Jul 2024, Nikolay Aleksandrov wrote:

> On 11/07/2024 07:59, 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@xxxxxxxxxxxxxxxxxxx>
> > ---
> >
> > v2:
> > - Restructure the MST mode check to make it read better
> > v1: https://scanmail.trustwave.com/?c=20988&d=i-GP5uRIMfh6vd5ovR02aBzmN2wu2NxHqGSNFOAFMA&u=https%3a%2f%2flore%2ekernel%2eorg%2fall%2f20240705030041%2e1248472-1-elliot%2eayrey%40alliedtelesis%2eco%2enz%2f
> >
> > 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..e63d6f6308f8 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) || state == BR_STATE_FORWARDING) &&
>
> Does this compile at all? How exactly did you test this change?
> There is no "state" variable in that context.
>

My apologies I must have sent an older patch. I will re-test and submit a
v3.