netdev - Re: [PATCH v15 nf-next 3/3] netfilter: nft_chain_filter: Add bridge double vlan and pppoe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aQPxULsaFi0uIV8u@strlen.de>
Date: Fri, 31 Oct 2025 00:14:24 +0100
From: Florian Westphal <fw@...len.de>
To: Eric Woudstra <ericwouds@...il.com>
Cc: Pablo Neira Ayuso <pablo@...filter.org>,
	Jozsef Kadlecsik <kadlec@...filter.org>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Nikolay Aleksandrov <razor@...ckwall.org>,
	Ido Schimmel <idosch@...dia.com>, netfilter-devel@...r.kernel.org,
	netdev@...r.kernel.org, bridge@...ts.linux.dev
Subject: Re: [PATCH v15 nf-next 3/3] netfilter: nft_chain_filter: Add bridge
 double vlan and pppoe

Eric Woudstra <ericwouds@...il.com> wrote:
> > I also vaguely remember I commented that this changes (breaks?) existing
> > behaviour for a rule like "tcp dport 22 accept" which may now match e.g.
> > a PPPoE packet.
> > 
> > Pablo, whats your take on this?  Do we need a new NFPROTO_BRIDGE
> > expression that can munge (populate) nft_pktinfo with the l4 data?
> > 
> > That would move this off to user policy (config) land.
> > 
> > (or extend nft_meta_bridge, doesn't absolutely require a brand new expression).
> > 
> Did you get any answer on this somewhere? I think that answer may affect
> this commit, so I'll wait before sending the next version for now.

Sorry for dropping the ball on this.  No, I did not.

First step is to write up a summary of the current behaviour,
then decide on a how-do-we-want-this-to-work and then on
an how-to-get-there.

I think for the second part (how-do-we-want-this-to-work)
the 'greedy' approach proposed by Antoine (ip saddr 1.2.3.4
matches regardless of l2 encap) makes sense but it will be hard
to get there.

I will try to cook up a proposal/rfc sometime next week.