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

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Date:   Mon, 1 Oct 2018 21:25:26 +0300
From:   Ido Schimmel <idosch@...sch.org>
To:     Richard Weinberger <richard@....at>
Cc:     Florian Fainelli <f.fainelli@...il.com>,
        Richard Weinberger <richard.weinberger@...il.com>,
        Stephen Hemminger <stephen@...workplumber.org>,
        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

On Mon, Oct 01, 2018 at 08:16:22PM +0200, Richard Weinberger wrote:
> Florian,
> 
> Am Montag, 1. Oktober 2018, 18:24:25 CEST schrieb Florian Fainelli:
> > If all you are doing is forwarding anything, one thing I experimented
> > with before is the following:
> > 
> > # tc qdisc add dev eth1 handle ffff: ingress
> > # tc qdisc add dev eth3 handle ffff: ingress
> > # tc filter add dev eth3 parent ffff: u32 \
> > > match u32 0 0 \
> > > action mirred egress redirect dev eth1
> > # tc filter add dev eth1 parent ffff: u32 \
> > > match u32 0 0 \
> > > action mirred egress redirect dev eth3
> > # ifconfig eth3 promisc
> > # ifconfig eth1 promisc
> > 
> > and this works just fine actually, bypassing the bridge layer entirely.
> 
> Yeah, mirred is a powerful knife. :-)
> 
> In my case it is too low level since I utilize the netfilter functionality of
> the bridge layer.

You can use mirred only for the specific packets you care about and let
the rest continue to the bridge.