Re: [RFC PATCH net-next 2/2] net: dcb: add new apptrust attribute

[Vladimir Oltean <vladimir.oltean@nxp.com>]

Hi Daniel,

On Thu, Sep 08, 2022 at 02:04:42PM +0200, Daniel Machon wrote:
> Add a new apptrust extension attribute to the 8021Qaz APP managed
> object.
> 
> The new attribute is meant to allow drivers, whose hw supports the
> notion of trust, to be able to set whether a particular app selector is
> to be trusted - and also the order of precedence of selectors.
> 
> A new structure ieee_apptrust has been created, which contains an array
> of selectors, where lower indexes has higher precedence.
> 
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> ---

Let's say I have a switch which only looks at VLAN PCP/DEI if the bridge
vlan_filtering setting is enabled (otherwise, the switch is completely
VLAN unaware, including for QoS purposes).

Would it be ok to report through ieee_getapptrust() that the PCP
selector is trusted when under a vlan_filtering bridge, not trusted when
not under a vlan_filtering bridge, and deny changes to ieee_setapptrust()
for the PCP selector? I see the return value is not cached anywhere
within the kernel, just passed to the user.