From mboxrd@z Thu Jan  1 00:00:00 1970
From: Philip Craig <philipc@snapgear.com>
Subject: Re: Transparent proxying using REDIRECT
Date: Thu, 17 Jul 2003 17:35:49 +1000
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To: Mikko Alutoin <mikko.alutoin@vtt.fi>
Cc: netfilter@lists.netfilter.org

Mikko Alutoin wrote:
> How does the proxy get to know the original destination IP address and 
> port? By looking into the HTTP-request, perhaps? If so, what if the 
> application protocol (some other than HTTP) does not contain the 
> destination URL?

Use SO_ORIGINAL_DST, for example:

getsockopt(fd, SOL_IP, SO_ORIGINAL_DST, &dst_addr, &addrlen);

-- 
Philip Craig - philipc@snapgear.com - http://www.SnapGear.com
SnapGear - Custom Embedded Solutions and Security Appliances