netdev - Re: [PATCH net-next v1 1/1] net: bridge: ensure that link-local traffic cannot unlock a locked port

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Date:   Fri, 29 Jul 2022 07:23:19 +0200
From:   Hans S <schultz.hans@...il.com>
To:     Vladimir Oltean <olteanv@...il.com>
Cc:     Ido Schimmel <idosch@...dia.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>, Jiri Pirko <jiri@...nulli.us>,
        Ivan Vecera <ivecera@...hat.com>,
        Roopa Prabhu <roopa@...dia.com>,
        Nikolay Aleksandrov <razor@...ckwall.org>,
        Shuah Khan <shuah@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Hans Schultz <schultz.hans+netdev@...il.com>,
        linux-kernel@...r.kernel.org, bridge@...ts.linux-foundation.org,
        linux-kselftest@...r.kernel.org
Subject: Re: [PATCH net-next v1 1/1] net: bridge: ensure that link-local
 traffic cannot unlock a locked port

On Sun, Jul 24, 2022 at 10:09 AM Hans S <schultz.hans@...il.com> wrote:
>
> On Thu, Jul 21, 2022 at 1:45 PM Vladimir Oltean <olteanv@...il.com> wrote:
> >
> > On Sun, Jul 17, 2022 at 09:20:57PM +0200, Hans S wrote:
> >
> > I'm only pointing out the obvious here, we need an opt in for MAB, and
> > the implemented behavior I've seen here kind of points to mapping this
> > to "+learning +locked", where the learning process creates locked FDB entries.
>
> I can go with the reasoning for the opt in for MAB, but disabling link
> local learning system wide I don't think is a good idea, unless
> someone can ensure me that it does not impact something else.
> In general locked ports should never learn from link local, which is a
> problem if they do, which suggests to me that this patch should
> eventually be accepted as the best solution.

Hi Vladimir,
sorry, I forget myself. We cannot use +learning as an opt in for MAB
with this driver, as there will be no HW refresh and other interrupts
like the age out violation will not occur either, which will be needed
further on.
If we really need an opt in for MAB, I think it will have to be a new flag.
Hans