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Date:   Sun, 11 Sep 2022 03:13:46 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     netdev@kapio-technology.com
Cc:     Ido Schimmel <idosch@nvidia.com>, davem@davemloft.net,
        kuba@kernel.org, netdev@vger.kernel.org,
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        Hauke Mehrtens <hauke@hauke-m.de>,
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Subject: Re: [PATCH v5 net-next 6/6] selftests: forwarding: add test of
 MAC-Auth Bypass to locked port tests
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On Fri, Sep 09, 2022 at 03:11:56PM +0200, netdev@kapio-technology.com wrote:
> > > > On Wed, Sep 07, 2022 at 11:10:07PM +0200, netdev@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?