Re: [PATCH wpan-next 01/20] net: mac802154: Allow the creation of coordinator interfaces

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Alexander Aring <aahringo@redhat.com>
Cc: Alexander Aring <alex.aring@gmail.com>,
	Stefan Schmidt <stefan@datenfreihafen.org>,
	linux-wpan - ML <linux-wpan@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Eric Dumazet <edumazet@google.com>,
	Network Development <netdev@vger.kernel.org>,
	David Girault <david.girault@qorvo.com>,
	Romuald Despres <romuald.despres@qorvo.com>,
	Frederic Blain <frederic.blain@qorvo.com>,
	Nicolas Schodet <nico@ni.fr.eu.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH wpan-next 01/20] net: mac802154: Allow the creation of coordinator interfaces
Date: Mon, 29 Aug 2022 10:05:21 +0200	[thread overview]
Message-ID: <20220829100521.04b52196@xps-13> (raw)
In-Reply-To: <CAK-6q+gZ5fSdNptvQoKpf1SOqODv70gzbFTYyWBagC6AFtAkig@mail.gmail.com>

Hi Alexander,

aahringo@redhat.com wrote on Sun, 28 Aug 2022 22:31:19 -0400:

> Hi,
> 
> On Fri, Aug 26, 2022 at 4:08 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> ...
> > >
> > > I need to say that I really used multiple monitors at the same time on
> > > one phy only and I did that with hwsim to run multiple user space
> > > stacks. It was working and I was happy and didn't need to do a lot of
> > > phy creations in hwsim.  
> >
> > Indeed, looking at the code, you could use as many MONITOR interfaces
> > you needed, but only a single NODE. I've changed that to use as many
> > NODE and COORD that we wish.
> >  
> 
> Be careful there, there is a reason why we don't allow this and this
> has to do with support of multiple address filters... but here it
> depends also what you mean with "use".

I've updated this part, you're right I was not careful enough on the
per-iface filtering part, I think it's fine now. Basically, compared to
the v2 sent last week, I've stopped considering that if one interface
was in promiscuous mode, all of them should and did a per-PHY check, so
that otherwise we can apply the necessary filtering if needed.

> I need to admit, you can achieve the same behaviour of multiple user
> space stacks and one monitor, _but_ you can easily filter the traffic
> if you do it per interface...

Thanks,
Miquèl