Re: [PATCH v5 net-next 6/6] selftests: forwarding: add test of MAC-Auth Bypass to locked port tests

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,
	Florian Fainelli <f.fainelli@gmail.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Kurt Kanzenbach <kurt@linutronix.de>,
	Hauke Mehrtens <hauke@hauke-m.de>,
	Woojung Huh <woojung.huh@microchip.com>,
	UNGLinuxDriver@microchip.com, Sean Wang <sean.wang@mediatek.com>,
	Landen Chao <Landen.Chao@mediatek.com>,
	DENG Qingfang <dqfext@gmail.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Claudiu Manoil <claudiu.manoil@nxp.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Jiri Pirko <jiri@resnulli.us>, Ivan Vecera <ivecera@redhat.com>,
	Roopa Prabhu <roopa@nvidia.com>,
	Nikolay Aleksandrov <razor@blackwall.org>,
	Shuah Khan <shuah@kernel.org>,
	Christian Marangi <ansuelsmth@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Yuwei Wang <wangyuweihx@gmail.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	bridge@lists.linux-foundation.org,
	linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v5 net-next 6/6] selftests: forwarding: add test of MAC-Auth Bypass to locked port tests
Date: Sun, 11 Sep 2022 03:13:46 +0300	[thread overview]
Message-ID: <20220911001346.qno33l47i6nvgiwy@skbuf> (raw)
In-Reply-To: <152c0ceadefbd742331c340bec2f50c0@kapio-technology.com>

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?