From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Hector <rhector@paradise.net.nz>
Subject: detect original chain after jump?
Date: Sun, 28 Mar 2004 01:38:01 +1200
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To: netfilter@lists.netfilter.org

Hi,

Mostly, people seem to write their filter chains splitting first by
interface and/or address, then by protocol/port.

I'm experimenting with doing it the other way round: I want to process
all the ssh traffic in one chain, then all the smtp in another etc.

This means that early on, I have something like:

iptables -A INPUT -j protocol
iptables -A FORWARD -j protocol

iptables -A protocol -p tcp --dport 22 -j ssh

But then I get a bit stuck. I need to then do different things depending
on the source and destination - which includes whether this packet is
arriving locally or being forwarded. Therefore it would be useful to
know whether this packet started out in the INPUT or FORWARD chain - but
that info seems to have been lost with the jump.

Is there any way to regain that?

Many thanks,

Richard