From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: ip_queue, libnetfilter_queue, and packet alteration Date: Wed, 23 Jul 2008 19:13:47 +0200 Message-ID: <488766CB.9060102@trash.net> References: <7915e7b50807221702m752d5b74y9283a28f4b9b1689@mail.gmail.com> <20080723094512.GA2250@khasse.inl.fr> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080723094512.GA2250@khasse.inl.fr> Sender: netfilter-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Eric Leblond , Curtis Wyatt , netfilter@vger.kernel.org Eric Leblond wrote: > Hello, > > On Tuesday, 2008 July 22 at 17:02:14 -0700, Curtis Wyatt wrote: >> I am using ip_queue. I understand that is depreciated. >> >> I want to intercept a packet, alter it (change payload and source ip >> address and destination ip address) and then do an NF_ACCEPT on it, to >> have it continue on its way to another machine. However it never >> shows up at that other machine. Is there anyway to do this without >> doing an NF_DROP and then sending a new packet through? >> >> Will libnetfilter_queue do this for me? > > Yes, but you will have to compute the checksum of the modified packet by > yourself. > > Someone should send a patch which adds helper functions to ease that > task in a day or two. That makes sense. It would also allow to take advantage of hardware TX csumming.