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From: Florian Westphal <fw@strlen.de>
To: Alessandro Vesely <vesely@tana.it>
Cc: netfilter <netfilter@vger.kernel.org>
Subject: Re: Upgrading libnetfilter_queue to use nftables
Date: Thu, 14 Nov 2019 04:12:46 +0100	[thread overview]
Message-ID: <20191114031246.GI19558@breakpoint.cc> (raw)
In-Reply-To: <28ab2afb-a16a-14ae-e511-aa4e641c1f24@tana.it>

Alessandro Vesely <vesely@tana.it> wrote:
> I'm using Debian 9 (stretch) and saw that the current version (Debian 10, buster) transparently installs nftables instead of iptables, offering to switch back by setting alternatives.
> I'm worried how smoothly an upgrade would go.  I have calls similar to these:
> 
> iptables -A INPUT -j NFQUEUE
>
> or
> 
> iptables -t raw -A OUTPUT -p tcp ! --syn -j NFQUEUE --queue-num 2
> iptables -A OUTPUT -p tcp ! --syn -m mark --mark 4 -j REJECT --reject-with tcp-reset
> 
> There is a user space filter reading queued packets and issuing verdicts.  It is linked to libnetfilter_queue, libnfnetlink and libmnl.
> Does automatic translation work fine in this case?

It has nothing to do with translation, userspace doesn't care, its the
same interface.

> Do I have (better) to relink, recompile, and/or rewrite the user space packet filter in order to use nftable?  How simple is that?

No relink/rewrite needed, userspace can't tell if queueing came via
-j NFQUEUE or nftables' queue, its the same kernel facility (nfnetlink_queue).

  reply	other threads:[~2019-11-14  3:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-13 17:41 Upgrading libnetfilter_queue to use nftables Alessandro Vesely
2019-11-14  3:12 ` Florian Westphal [this message]
2019-11-14  9:03   ` Alessandro Vesely
2019-11-18  0:53     ` Trent W. Buck

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