[Click] How do I do this?

[Adam M]

Hi folks,

I'd like to have Click running as a UDP server (in userspace) listening
for packets from the physical network interface (eth0). Therefore, when
eth0 receives a UDP packet destined for the correct port number, the
packet gets delivered to Click.

Once Click gets the packet, my network simulation code takes over. The
simulation code implements protocols relating to wireless networking.
Once the simulation is finished processing the packet, it delivers the
packet to a virtual interface using TUN.

The userspace applications are listening for packets from the virtual
interface, and have no idea that Click is running between the physical
interface and the virtual interface.

Of course, this is clearly not efficient. However, it is simple and good
enough for what I need to accomplish.

I'm trying to figure out how to do this with Click. Do I need to write
my own Element to act as a UDP server that delivers packets to a virtual
interface? Are there some Elements I can use out of the box to make life
easier?

Thanks again,
Adam