netfilter_queue: how to obtain address info from queued packet

[Michal Martinek <michal.martinek@siemens.com>]

Hello all,

I am quite a newbie to the netfilter world, so maybe my approach is 
naive. I would like to block communication coming from/to some ports 
according to the content of packets. Unfortunately these ports are not 
static, so port specific netfilter rule cannot be used. So my question is:
Is it possible to obtain some address info (source/destination address 
and ports) from the packet queued from netfilter?

Thanks in advance for any help,

Michal