Hello,

I require C Language Source Code to block Specific Network protocols and ports which can be used on LINUX with some documentation

Regards,
Ramesh

The C Programming Language (2nd Edition)





Or, you may want to utilize Netfilter.org's work and use the Iptables framework for building firewalls, which is already in place in the Linux kernel and various related user-land tools, instead of writing your own.

Linux contains a mechanism for doing this and a lot more called netfilter. When building the kernel, it can be excluded, but it is present is kernels which ship with most mainstrean distros.

iptables is a tool used to configure netfilter. There are other tools to do the same thing, which may be more user-friendly. You don't need to write a C program to configure netfilter - just to use one of these tools.

If you're looking for a nice GUI which provides basic personal firewall type configuration options, take a look at firestarter. There are plenty of others too - you're sure to find something which fits your needs.

Just thought I should mention that best practice is to block all ports/protocols/traffic with a firewall, and then open up only that which you need to.