Update:

I have not touched this code in years, therefore I am putting this repository in Archive mode since there are apparently still some active users.

Disclaimer:

This software is provided as is. I take no responsibility if it destroys your data or opens up a security hole on your firewall. That said, I have yet to hear something about this happening.

I did not create this code myself, most was written by Tom Marshall, later on Harald Welte and then Steven van Acker ported it to the new 2.6 netfilter API. I just picked up this code in 2007 and made it compile and hopefully work with the new changed netfilter API.

Bugs:

Of course there are. One of the most important ones, is that you MUST NOT filter outgoing connections otherwise the reply packes go missing. I tried to figure out, why the _expect call is not taking care of the outgoing connections but I was not able to figure this out. I gladly welcome patches that fix this and other bugs.

Build Instructions:

Have the kernel source ready in some place and NF_CONNTRACK_NAT enabled in the configuration otherwise you will get an error during make. The Kbuild setup looks in /lib/modules/`uname -r`/build for the source.

If the source is located in another place set the KERNELDIR environment variable accordingly.

After that a:

* make 
* make modules_install (as root)

should be enough.
Then do a "modprobe nf_nat_rtsp" as root and try to connect to a RTSP service.