Perl/PHP tools to decode/encode DNS requests/replies?

["Kelly Jones" <kelly.terry.jones@gmail.com>]

I'd like to write my own DNS server using Perl or PHP. I've read the
RFC, and was wondering if there was a Perl/PHP tool that would:

1. Decode and parse an incoming DNS request so I could see what domain
is being looked up, what record type is being requested, etc

2. Let me create a response packet with the DNS reply (IP address for
CNAME requests, hostnames for MX requests, arbitrary text for TXT
requests, etc).

DNS over UDP seems like a neat way of passing small pieces of
information w/o the overhead of TCP. I'm surprised more people aren't
using it?