Re: [PATCH net-next v3 5/8] net: dsa: vsc73xx: Add vlan filtering

[Vladimir Oltean]

On Tue, Oct 03, 2023 at 11:14:55PM +0200, Paweł Dembicki wrote:
> Should I make a local copy of the quantity of egress untagged and
> tagged vlans per port to resolve this issue, shouldn't I?
> And then I check how many vlans are egress tagged or untagged for a
> properly restricted solution?

Yeah, I guess so. It is the same problem that ocelot_vlan_prepare()
tries to solve, and that counts ocelot_port_num_untagged_vlans() and
ocelot_port_num_tagged_vlans() indeed.

> I see another problem. Even if I return an error value, the untagged
> will be marked in 'bridge vlan' listing. I'm not sure how it should
> work in this case.

What error code are you returning, -EOPNOTSUPP I guess? That's
deliberately ignored by callers of br_switchdev_port_vlan_add(), because
it means "no one responded to the switchdev notifier, so the VLAN is not
offloaded". If you want to deny the configuration you need to return
something else, like -EBUSY.