Subject: Re: [RFC net] net: dsa: Centralize validation of VLAN configuration

From: Andrew Lunn <[email-masked]>
Date: Wed, 10 Mar 2021 01:30:33 +0100

On Tue, Mar 09, 2021 at 10:28:11PM +0100, Tobias Waldekranz wrote:

Hi Tobias

As with Florian, i've not been following the discussion.

> Yeah sorry, I can imagine that makes no sense whatsoever without the
> context of the recent discussions. It is basically guarding against this
> situation:
> 
> .100  br0  .100
>    \  / \  /
>    lan0 lan1
> 
> $ ip link add dev br0 type bridge vlan_filtering 1
> $ ip link add dev lan0.100 link lan0 type vlan id 100
> $ ip link add dev lan1.100 link lan1 type vlan id 100
> $ ip link set dev lan0 master br0
> $ ip link set dev lan1 master br0 # This should fail

Given the complexity at hand, maybe consider putting this all into the
code?

	Andrew