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 other wise you will get an error during make. The Kbuild setup looks in /lib/modules/`uname -r`/build for the source.
If you have the it 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.