hi-- looking for some help

hi
i saw your email inthe following link:
http://lists.freebsd.org/pipermail/freebsd-current/2011-August/026412.html

im studying in portugal and in have acourse about pc networking.
there i have propossed to implement exactly the same thing as you have
described in your email.
i would like to know if ou can give me the source code of it to take some
inspiration.
if not can you at least tell me briefly how that is done?
or at least from where i must begin to have any idea about how that is done?
or at least where i can look at some code to have some clues on how that is
done?

i need it to be done in c for linux

i thnk you in advance for your answer
best regards