I've go t a small but very important problem... please help me

[Alberto]

I'm writing a router using click..
I've quite finisched but the problem is that I need to visualize inside the router (that works in kernel 
mode) the ip destination address and the tcp/udp port (real port) that are stored inside the header of the 
packet..... and I really don't know how to do ... 
The packets could be TCP or UDP ... 

There is someone that could give me please an idea ?

Thank you for all by now............