querying an NT domain for a list of logged-in users

[Stephen Langasek]

Hello all,

I'm investigating the possibility of creating a Linux-based firewall
solution which can allow or reject connections based on the identity of the
user currently logged into a machine, similar to what's possible with MS
Proxy Server.  I know that nmblookup can be used to query the logged-in user
on a Win9x machine; is there a similar ready-made mechanism that can be used
in an NT domain setting?  Better still, would there be a (painless) way to
get an NT PDC to inform a Unix server of domain logons/logoffs?  Or would it
be better/easier to use the Linux machine as the PDC in this case?

TIA,
-Steve Langasek
postmodern programmer