Xvnc via xinetd Linux - login and desktop issues

Collins, Kevin (MindWorks) KCollins "at" chevrontexaco.com
Wed Jun 1 21:18:00 2005

If you install the Enterprise version, you can use the vnc from xinetd
and autheticate via your linux passwd.

Here is what one of my xinetd entries looks like:

service vnc-1024x768x8
          protocol = tcp
          socket_type = stream
          wait = no
          user = nobody
          server = /usr/bin/Xvnc
          server_args = -inetd -query myhostname -fp unix/:7100 -once
-SecurityTypes=RA2 -UserPasswdVerifier=none -ge
ometry 1024x768 -depth 8

And the matching /etc/services entry:

vnc-1024x768x8 5952/tcp

Hope this helps...


-----Original Message-----
From: vnc-list-admin "at" realvnc.com [mailto:vnc-list-admin "at" realvnc.com] On
Behalf Of Vamsi Krishna
Sent: Wednesday, June 01, 2005 11:30 AM
To: DUNWELL "at" jila.colorado.edu; vnc-list "at" realvnc.com
Subject: Re: Xvnc via xinetd Linux - login and desktop issues


>in the server_args option, when I try to connect via 'vncviewer' with 
>the option
>   -securitytypes=VncAuth
>included or not there at all, then the vnc password screen pop up and 
>request the password. However it always fails. You can see that I tried

>to specify my personal password file w/o success. I have tried 
>specifying user = dunwell as well hoping it might see my personal vnc 
>password. No luck. How do I set a system-wide vnc password such that it

>will be recognized at this login level via xinetd? 

Use the option user=root in the xinetd options. 
The service needs read access to the password file
to perform authentication. You can create a system level password file
using vncpasswd /tmp/<filename> and use the same filename in your Xvnc

>If I instead use the option
>   -securitytypes=none
>then I do not get the vnc password screen. Instead it forms up the vnc 
>X-window frame with a black background. I get no linux xdm login screen

>or any other X-ness. Obviously something further is needed in order to 
>get it to process. Note that the man page for Xvnc under the inetd 
>section says that just this much, either with 'wait' or 'nowait' should

>pop up the XDM login screen but this is not happening for me.

This must be becasue XDMCP is disabled on your machine by defualt.
The easiest way to verify if the XDMCP is enabled is to check if the
display manager
is binding UDP port 177. 

XDMCP is the control protocol used by Display Managers like xdm, gdm and
kdm to
manage the user desktop session. The -query localhost option is the Xvnc
side option
to make XDMCP requests to the Display Manager for login. You dont need
any changes
in the xinetd script. The only changes required are to enable your
display manager to 
talk XDMCP and you will see a login screen. Remember to restart the
display manager 
after the changes.

To configure XDMCP if your display manager is 
1.gdm - use gdmsetup
2.kdm - use
3 xdm - use http://www.tldp.org/HOWTO/XDMCP-HOWTO/

Hope this helps!!!!

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