It's unlikely that this code will ever be released; take a look at Dave Plonka's Net::Patricia if you want something in code that will help you express address lookup problems in perl.
Preserved for old times sake is the original silliness:
At the moment, I'm only releasing the documentation for the module for review. I will release the code shortly, if nobody points out interface issues to me that I feel I should fix. You'll be able to find it here and at the normal CPAN sites.
Here's the bits: