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Date: Thu, 4 Jun 2026 01:11:17 +0200
From: Florian Westphal <fw@strlen.de>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [RFC nf 0/2] netfilter: add restrictions/validations for packet
 rewrites
Message-ID: <aiC0lYKyD5UDQgLS@strlen.de>
References: <20260527121147.22076-1-fw@strlen.de>
 <aiCrpdgRNCC7LkaA@chamomile>
 <aiCtz2nBZL1Q-gmL@chamomile>
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Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > If anyone is breaking with ilegals field, they should come here to
> > explain? Data plane validation might look safer ... but it will just
> > drop packets and it will take a bit more time to the user to debug.
> > But your approach is more conservative, it just leave the packet
> > untouch, so it is basically ignoring the invalid mangling.

Yes, ignore resp. BREAK verdict.

> Hm. Actually, it is harder than it seems to do this from control plane
> because dscp needs to deal with bitwise to ensure that ihl and version
> are not modified.

Yes, there are cases like those where control plane valition is not
possible.  I will address the AI comments and resubmit w.o. RFC tag.

Thanks for reviewing.