While looking for a fun way to filter my WIFI traffic, I decided to look at userland firewall API in Python. I found: ipqueue.
I haven’t really wrote a full featured app with it, but here the first things to make it work.
# load the kernel queue module modprobe ip_queue # all outgoing ping will pass throught the queue iptables -A OUTPUT -p icmp -j QUEUE
Now here a little script that act as the queue
import ipqueue q = ipqueue.IPQ(ipqueue.IPQ_COPY_PACKET) while 1: p = q.read() pID = p[ipqueue.PACKET_ID] print pID # accept the packet q.set_verdict(pID,ipqueue.NF_ACCEPT)
Next step, simply run this script with the root privilege, and you will see outgoing ping print on the stdout.
Additionnal note: ipqueue only works on python2.2 right now, I hope Neale will fix that soon. Anyway this is really a nice piece of code thanks guy!