Idea for a program: UPnP

[Virchanza]

I dunno if this program would be really useful, but I think it'd be fun to write and it'd keep my programming skills sharp

Anyway, lately we've been talking about the UPnP protocol which is used by some routers. Basically you can send a request to the router to ask it what ports it is forwarding, and it will reply with a list, e.g.:
TCP port 80 on the WAN goes to TCP port 80 on LAN computer 10.10.10.5.
TCP port 443 on the WAN goes to TCP port 80 on LAN computer 10.10.10.18.

Also you can use this protocol to send requests to forward new ports, or to cancel any port forwarding that's already in place.

I think it'd be really neat to make a tiny little Linux program out of it, something like:

root@bt:~# portfwd --list
Sending request to router... timeout in 5 seconds...
Router response as follows:

WAN Port        goes to        LAN IP address        LAN Port
-------                        ----------------       -----------
TCP 80                          10.10.10.5             TCP 80
UDP 21                          10.10.10.2             UDP 22
TCP 443                         10.10.10.7             TCP 80

root@bt:~# portfwd --add TCP80 10.10.10.9 TCP81
Sending request to router... timeout in 5 seconds...
Request successful, requested port forwarding has been enabled.

root@bt:~# portfwd --del TCP80
Sending request to router... timeout in 5 seconds...
Request successful, requested port forwarding has been disabled.

Does anyone know of any other little project that does this? I've been searching the net for a little while but I've only found server applications, server libraries and server source code. I've yet to see any client applications like what I'm suggesting.

If you've ever used M$ WinXP, you might have noticed in the system tray in the bottom right corner, that sometimes an icon appears for your network connection saying something like "Intelligent Gateway Device detected on the network". As far as I know, this means it's found a router on the LAN that support UPnP.

[compaq]

Hope it helps, could never get the program to work

RapidShare: Easy Filehosting

[Virchanza]

I spent some time searching the web for the specifics of the UPnP protocol, i.e. what kind of packet I have to send to open a port, but couldn't find anything.

There's already a graphical M$Windoze program available for doing this, so I'm gonna boot into WinXP, open up Wireshark, and then run the UPnP program. I'll keep Wireshark running as I open ports, close ports, query which ports are currently forwarded. I'm gonna save the frames I capture and copy them across to Linux, then boot back into Linux and work on writing the frames in C code

[Gitsnik]

I bookmarked this for you the other day when I was searching for something else, but promptly forgot about it.

Anyhow, there was a project: miniupnp.tuxfamily.org (not sure if I can paste url's yet)

But it only works with certain types of UPnP devices. Still, it might be a good place for you to start.

Also make sure you make note of the wiresharp dump to C format option, it is infinitely useful for this sort of thing. (There is also perlupnp which I believe is hosted on sourceforge).

[Virchanza]

Originally Posted by Gitsnik

I bookmarked this for you the other day when I was searching for something else, but promptly forgot about it.

Anyhow, there was a project: miniupnp.tuxfamily.org

That's fantastic thanks, I'm looking over it now. I've downloaded the source code for the Client program, gonna have a look over it tomorrow.

Also make sure you make note of the wiresharp dump to C format option, it is infinitely useful for this sort of thing.

I've only learned of this function now! I'd no idea you could make it produce C code!

[enonym]

I liked the idea.
You know, I really like python. So I have to suggest:
brisa.garage.maemo.org
It is a UPnP framework for python.