From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Bedogni Subject: Re: Routing packets via a C program Date: Tue, 30 Jan 2007 17:14:10 +0100 Message-ID: <200701301714.10868.bedogniluca-linux@yahoo.it> References: <200701220958.51794.bedogniluca-linux@yahoo.it> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-bounces@lists.netfilter.org Errors-To: netfilter-bounces@lists.netfilter.org Content-Type: text/plain; charset="us-ascii" To: Jan Engelhardt Cc: netfilter@lists.netfilter.org On Saturday 27 January 2007 15:55, Jan Engelhardt wrote: > On Jan 22 2007 09:58, Luca Bedogni wrote: > >Hi all > > i'm writing down a simple program for routing the packets manually. The > >idea is: if a packet comes from a specific IP (192.168.0.2) I set > > ip->saddr to my ip and then accept it. And, if a packets comes from the > > outside, i set ip->daddr to 192.168.0.2 and then accept it. I recalculate > > the checksum and it's correct (i can see that by printing out it). > > What for - are you trying some nifty SNAT/DNAT trick? Yes, i want to monitor performances and such via normal routing and via userspace routing. > >The basic problem is that, sniffing packets with wireshark, i can see the > >packet from 192.168.0.2 to outside, but not mine to outside. > > > >I also tried with NF_REPEAT and NF_ACCEPT and NF_QUEUE when calling > >ipq_set_verdict, but nothing changed.. > > You should be fine by QUEUEing packets in PREROUTING (or at least somewhere > before the in [PacketFlow]), modify them in your > userspace program, reinject them, and have the do the > right then. Yes i basically do this, but the packets aren't reinjected. I change the IP and recalculate the checksum, but when calling ipq_set_verdict I can't see any packets on the wire :( Any other hint? > -`J' Regards -- Debian Powered GNU/Linux User #373118 Bedogni Luca - Blog | http://blog.lucabedogni.it Site | http://www.lucabedogni.it Debianizzati - www.debianizzati.org | Founder Member -- Better paranoid than sorry