On Tue, 25 Jan 2000 05:04:14 +0100 (CET) 
 Simon Richter <Simon.Richter@phobos.fachschaften.tu-muenchen.de> wrote:

 > Option 2: AF_UNIX datagram sockets. The only authentication method
 >   supported is a Linux specific extension that allows credential data to
 >   be passed as an ancilliary message, checked by the kernel. As this is
 >   not supported under *BSD or any other platform, I think this is a bad
 >   option.

NetBSD has an option like this ... take a look at sys/socket.h for
"sockcred".  The unix(4) manual page also describes the sockcreds
facility (it's enabled by the LOCAL_CREDS socket option).

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>