openldap overlays

Greetings,

I'm relatively new to OpenLDAP and I think I am an average user and a newbie when it comes to development. I am currently on a project on which we use openldap2.4 and the dyngroup overlay. My goal is to build another group overlay which will fetch data from outside the ldap machine (webservices) and then works just like the regular dyngroup overlay, returning the members of that group based on the results of the call to the webservices.

The problem is, like I said, that I'm a newbie. I looked at dyngroup.c and I find it quite hard to understand what is going on. It has very few comments and of little help. Can someone give me an overview of the code, and maybe introduce me to the steps of creating an overlay?

thanks, Carlos Santos