Linux Ethernet Bridging - Sep 2022 - [Bridge] [PATCH v5 net-next 6/6] selftests: forwarding: add test of MAC-Auth Bypass to locked port tests

On Fri, Sep 09, 2022 at 03:11:56PM +0200, netdev at kapio-technology.com
wrote:
> > > > On Wed, Sep 07, 2022 at 11:10:07PM +0200, netdev at
kapio-technology.com wrote:
> > > > > I am at the blackhole driver implementation now, as I
suppose that the
> > > > > iproute2 command should work with the mv88e6xxx driver
when adding blackhole
> > > > > entries (with a added selftest)?
> > > > > I decided to add the blackhole feature as new ops for
drivers with functions
> > > > > blackhole_fdb_add() and blackhole_fdb_del(). Do you
agree with that approach?
> > > >
> > > > I assume you are talking about extending
'dsa_switch_ops'?
> > > 
> > > Yes, that is the idea.
> > > 
> > > > If so, it's up to the DSA maintainers to decide.
> > 
> > What will be the usefulness of adding a blackhole FDB entry from user
> > space?
> 
> With the software bridge it could be used to signal a untrusted host in
> connection with a locked port entry attempt. I don't see so much use
other
> that test purposes with the driver though.
Not a huge selling point, to be honest. Can't the blackhole flag remain
settable only in the device -> bridge direction, with user space just
reading it?

On 2022-09-11 02:13, Vladimir Oltean wrote:
> On Fri, Sep 09, 2022 at 03:11:56PM +0200, netdev at kapio-technology.com 
> wrote:
>> > > > On Wed, Sep 07, 2022 at 11:10:07PM +0200, netdev at
kapio-technology.com wrote:
>> > > > > I am at the blackhole driver implementation now, as
I suppose that the
>> > > > > iproute2 command should work with the mv88e6xxx
driver when adding blackhole
>> > > > > entries (with a added selftest)?
>> > > > > I decided to add the blackhole feature as new ops
for drivers with functions
>> > > > > blackhole_fdb_add() and blackhole_fdb_del(). Do you
agree with that approach?
>> > > >
>> > > > I assume you are talking about extending
'dsa_switch_ops'?
>> > >
>> > > Yes, that is the idea.
>> > >
>> > > > If so, it's up to the DSA maintainers to decide.
>> >
>> > What will be the usefulness of adding a blackhole FDB entry from
user
>> > space?
>> 
>> With the software bridge it could be used to signal a untrusted host 
>> in
>> connection with a locked port entry attempt. I don't see so much
use
>> other
>> that test purposes with the driver though.
> 
> Not a huge selling point, to be honest. Can't the blackhole flag remain
> settable only in the device -> bridge direction, with user space just
> reading it?
That is possible, but it would of course not make sense to have 
selftests of the feature as that would not work unless there is a driver 
with this capability (now just mv88e6xxx).