[PATCH v8 net-next 10/12] net: dsa: mv88e6xxx: mac-auth/MAB implementation

[Vladimir Oltean]

On Fri, Oct 21, 2022 at 07:18:59PM +0200, netdev at kapio-technology.com wrote:
> On 2022-10-21 18:30, Vladimir Oltean wrote:
> > On Fri, Oct 21, 2022 at 03:16:21PM +0200, netdev at kapio-technology.com wrote:
> > > As it is now in the bridge, the locked port part is handled before learning
> > > in the ingress data path, so with BR_LEARNING and BR_PORT_LOCKED, I think it
> > > will work as it does now except link local packages.
> > 
> > If link-local learning is enabled on a locked port, I think those
> > addresses should also be learned with the BR_FDB_LOCKED flag. The
> > creation of those locked FDB entries can be further suppressed by the
> > BROPT_NO_LL_LEARN flag.
> > 
> > > If your suggestion of BR_LEARNING causing BR_FDB_LOCKED on a locked port, I
> > > guess it would be implemented under br_fdb_update() and BR_LEARNING +
> > > BR_PORT_LOCKED would go together, forcing BR_LEARNING in this case, thus also
> > > for all drivers?
> > 
> > Yes, basically where this is placed right now (in br_handle_frame_finish):
> 
> As I don't know what implications it would have for other drivers to have learning
> forced enabled on locked ports, I cannot say if it is a good idea or not.
> Right now learning is not forced either way as is, but the consensus is that learning
> should be off with locked ports, which it would be either way in the common case I
> think.

I don't think I fully understand what you mean by forcing BR_LEARNING.
A bridge port gets created with a default set of flags as can be seen in new_nbp().
Those flags include BR_LEARNING but don't include BR_PORT_LOCKED.

The user can decide he wants to make the port use 802.1X without MAB, so
he enables BR_PORT_LOCKED and disables BR_LEARNING, all with the same
netlink command (ip link set swp0 type bridge_slave learning off locked on).

How was the driver forced into anything?