running Xvnc as a handled display under gdm2

[Joe Philipps]

I have a RHL8.0 system, but this didn't work under RHL7.3 either.

I tried putting lines in gdm.conf to get gdm to start Xvnc for me.
Xvnc does start; I can connect with vncviewer and get the usual gray
background with a cursor.  However, after some seconds (gdm debug log
seems to indicate 10 seconds), Xvnc is killed by gdm.  In examining
the gdm source code (daemon/server.c) and matching the debug output
strings in the debug syslog, the source code indicates that gdm is in
a do { select() } while() loop, looking for something from a pipe.  My
two XFree86 X servers (one on vt7 and the other on vt9) get the
greeter/gdmlogin, but Xvnc has some sort of different idea of display
manager protocol than gdm or gdm2.  If I might be missing some option
that I just couldn't find in the docs, please let me know; I tried
most of them (like -terminate and -once).

As a workaround, I have an inittab line that respawns Xvnc, and XDMCP
is enabled in gdm.  I see all sorts of security warnings in the GDM
docs about turning XDMCP on, but I'm not too nervous about this one
case because it's on a firewall-protected network with only the
firewall plus two other 'puters.  But for wider application on a
possibly more hostile network, I wondered if Xvnc can be made to "play
nice" with gdm so I can turn XDMCP off (or so I don't have to add
iptables rules if XDMCP has to be left on, which would be another
workaround).