unlang/python "scripting" for gateway and dns servers

[Michael Duckett]

I'd like to derive the gateway based on unlang rules from the assigned ip
address/mask I store in ldap.  In what configuration file would I put the
unlang or python code to implement the rule?

For DNS servers, i want to use a subset of the username in something like a
case/switch statement.  Can I use the username in the accept request during
the authorization phase?  Where would i put this code (preferrably python
but could use unlang)?  Would I put in the authorize part of the default
config file?

Thanks