netdev - Re: [PATCH 1/1] bridge: remove BR_GROUPFWD_RESTRICTED for arbitrary forwarding of reserved addresses

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Date:   Mon, 01 Oct 2018 20:54:08 +0200
From:   Richard Weinberger <richard@....at>
To:     Ido Schimmel <idosch@...sch.org>,
        Stephen Hemminger <stephen@...workplumber.org>
Cc:     Florian Fainelli <f.fainelli@...il.com>, bernhard.thaler@...et.at,
        "David S. Miller" <davem@...emloft.net>,
        bridge@...ts.linux-foundation.org, netdev@...r.kernel.org,
        David Gstir <david@...ma-star.at>
Subject: Re: [PATCH 1/1] bridge: remove BR_GROUPFWD_RESTRICTED for arbitrary forwarding of reserved addresses

Am Montag, 1. Oktober 2018, 20:48:21 CEST schrieb Ido Schimmel:
> > This is my plan b, having a u32 classifier that transports STP directly
> > to the other interface.
> > But IMHO this all is a bit hacky and a "forward anything" bridge mode
> > sounds more natural to me.
> 
> But "forwarding STP and PAUSE if the number of slaves is restricted to
> 2" is a hack. The Linux bridge (like other networking equipment) needs
> to conform to standards and to the best of my knowledge what you're
> requesting is explicitly forbidden by IEEE standards.
> 
> Also, if what you need is "forward anything", then Florian's suggestion
> should work for you.

Agreed, both variants are hacks. Depending on the point of view one might seem
less hacky than the other. :-)

As I said, netfilter is also part of the game. Unless I miss something, netfilter
won't see any packets if tc-mirred is used.
So the only option is having a bridge and transport STP via tc-mirred
or patching the bridge code (what we do right now).
 
Thanks,
//richard