Simple solution not involving any kernel change will be to use raw sockets (man 7 packet). Read complete raw packets (including the MAC header) on one socket, modify it as you wish and then send the modified packet onto the other socket. \tomar On Tue, 10 Aug 2004, Luesley, William wrote: > > I have two devices setup as follows: > > > A --------------- B > 192.168.1.1 192.168.1.2 > > > The machines open a number of TCP and UDP ports with which to communicate. > In order to help testing, I have been asked to place a third machine between > these two which will be capable of intercepting and modifying any messages. > My initial plan was to have a device which could mimic both ends of the > connection (as I already have code to do this); with each connection being > on a separate NIC, leading to a setup as shown below: > > A ------------ C C ---------- B > 192.168.1.1 192.168.1.2 192.168.1.1 192.168.1.2 > (eth0) (eth1) > > The obvious problem with this is that as C implements both ends of the > interface, any messages it sends are routed internally, rather than being > sent to the correct host. > > I thought it would be possible to correct this by specifying the host routes > using the route command, i.e. setting a route to 192.168.1.1 via device eth0 > and to 192.168.1.2 via eth1, therefore stopping the internal routing from > occurring. Even with these routes setup, the messages are still routed > internally. > > > > Can the route somehow be forced? > > If not, is there a way to stop the internal routing, preferably without a > code change to the kernel (if it is a code change - can someone point me > towards the file)? > > Can I use IP Tables, how? > > Or, am I on totally the wrong track? > > > Thanks for peoples time spent reading and looking into this. > > > > > > > > ******************************************************************** > This email and any attachments are confidential to the intended > recipient and may also be privileged. If you are not the intended > recipient please delete it from your system and notify the sender. > You should not copy it or use it for any purpose nor disclose or > distribute its contents to any other person. > ******************************************************************** > - > : send the line "unsubscribe linux-net" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- -- You have moved the mouse. Windows must be restarted for the changes to take effect. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
