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Date: Thu, 16 Aug 2007 01:40:28 -0700
From: Julian Elischer <julian@elischer.org>
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To: Eric Anderson <anderson@freebsd.org>
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Cc: freebsd-hackers@freebsd.org
Subject: Re: Modifying bridged traffic
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Eric Anderson wrote:
> What is the easiest way to play with modifying data in-transit within an 
> ethernet bridge?
> 
> For instance, say I have something like this:
> 
> [BOX 1] <----> [ BOX 2 ] <----> [ BOX 3 ]
> 
> And BOX 2 is a FreeBSD box with bridging enabled between two ethernet 
> interfaces, how can I parse/modify the ethernet frames as they pass 
> through?

a netgraph bridge can do that (you can hook two ng_bridges together
and capture all the packets that flow between them...

There are also some patches that allow divert sockets to be
attached to a bridging ipfw firewall.

> 
> Eric
> 
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