Discarding Packets from LAN programatically

[suezkhan]

somebody plz let me know how i can stop or discard a packet over LAN using C. i mean is there any liberary or Header file which should i use in order to discard suppose SYN packets not to reach a specific application.
actually i am working on a firewall type application which would discard either TCP or othere packets on the basis of a policy. so is there any way out here to deal such situation..

[Qadri-409]

Dear suezkhan

read one of them

http://www.linuxguruz.com/iptables/howt ... HOWTO.html

http://iptables-tutorial.frozentux.net/ ... orial.html

http://www.siliconvalleyccie.com/linux- ... -intro.htm

take care

[blackdaemon]

salam:

work on netfilters library, its same library as used by iptables!. provides you all the functionalities with its hooks placed at all major nodes of the network stack. Kindly refer to following link:

http://www.linuxjournal.com/article/7184

yes ofcourse you'll need to write your module/driver for it, trustme its not as hard as it sounds especially after reading this >> www.tldp.org/LDP/lkmpg/2.4/lkmpg.pdf

Finally you'l get tremendous resources at www.kernelnewbies.org it really helped me out & im sure you'l benefit equally from it.