how to block packets

[scanty]

hi,
i m trying to develop an application to block packets(using c++)(like a firewall).
i have tried pcap library , but it doesnot block packet just captures them.

can anybody please suggest some solution to it !!

thanks in advance.

[Rubberman]

I'm not 100% certain, but I think you will need a kernel module to support this capability in a user-space program. I assume you don't mean just eating them (open socket/port and consume all incoming data), but more of a filtering capability. There may be a TCP/IP filtering function you can use that will do this already, but I'm not familiar with it if it exists.

[scanty]

I'm not 100% certain, but I think you will need a kernel module to support this capability in a user-space program. I assume you don't mean just eating them (open socket/port and consume all incoming data), but more of a filtering capability. There may be a TCP/IP filtering function you can use that will do this already, but I'm not familiar with it if it exists.

yes, definitely no consuming but filtering based on contents of the packet.
and if kernel module is required , then do u know which one it is ??