Basic firewall in Linux

HI,

A friend of mine is doing his project on writing a basic fire wall in linux using C.
Any references to source code or details are helpfull to us.

Thank U.
Data.

Try smoothwall, its a linux based one and is therefore free for you to rip to pieces and see how it works
[url]www.smoothwall.org[/url]

HI,

thank you,shall look at it.

Regards Data.