I am trying to build a firewall of sorts by messing around with the ip tables in the kernel. Now this tweaked kernel( w/ some extra rules added on to it) serves as the backend of the firewall. For the frontend i thought of using kde/qt as i have been recommended those.
Since i am a newbie at this, i want to know that if i use either qt or kde for frontend, how would i be able to set up an interaction of the frontend with the kernel so that only those rules that are checked in the frontend are implemented in the kernel?
All suggestions/help would be tremendously appreciated!!

This is just a guess.

Take a look at the script /etc/ppp/ip-up. This is the script that SuSE uses to start ppp. Red Hat may use a different script name to start ppp.

Once you find the ppp start up script maybe your frontend can influence the rules by modifying the ppp start up script before starting ppp.