I would not try to do "automatic configuration of the interface"
from this tool.  That's a complex process if done right -- see the 
dhclient man page.  A better idea would be to use the omapi interface 
to communicate with dhclient.  (Aside: a while ago, I posted a long 
note on how I think that dhclient should interact with tools like this. 
In particular, it needs to separate carrier detection from address 
acquisition.  If anyone is interested, I'll post the note again.)

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb