Linux Modules

[bmm at plu.edu]

Hi Doc Team,

I am a senior at Pacific Lutheran University and I am pursuing a degree in
computer science.  For my final project, me, and the group I am in, are
trying to create our own firewall module that will replace the netfilter
module in Ubuntu.  In order to do so we have been researching the
internals of Ubuntu, learning to write lower level programs and, of
course, teaching ourselves how to compile the kernel.  In our learning
experience what a module is has become hazy to us.  At first, we thought
of a module as another word for driver, but we have come to learn that it
is something more.  We also know that each module has to have someway of
telling the kernel that it is there and also being able to communicate
with the kernel in a basic manner right from the getgo, then developing
itself.  Then we also crossed paths with modules that are embedded into
the kernel and ones that "hang off" the kernel.  So we were wondering if
you could help us in our pursuit of our goal in telling us what a module
exactly.  Cause now when I think of a module, it is almost like an atom,
when you look at it, it was a spin up, but when you look at it again, it
has a spin down.  So if you could please help clarify what a module is or
what are the bounds of the linux module, we would be very thankful.

Thank You

Brian McFadden