Silly XDMCP/xdm/Linux question -xdm won't issue xdmcp queries properly.

Silly XDMCP/xdm/Linux question -xdm won't issue xdmcp queries properly.

Post by Richard Wat » Fri, 04 Mar 1994 11:12:06

    [Crossposted because this is essentially a Linux question]

  Hello. I'm running Linux on a Dell 486/L - 486DX2/66, S3 card, 8MB RAM,
Linux 0.99pl15 + quota + acct, XFree86 2.0 system, and I've been having
some problems with xdm. I've been trying to get my copy of xdm to display
a local chooser which will allow me to connect to localhost and a number
of foreign hosts via. xdmcp - basically, I want a chooser with 'localhost',
and some other hosts on it on the current display.

   All the hosts I want are xdmcp-query and -indirectable by my X server
(eg. X -indirect bootes.cus or X -query bootes.cus will work and give the
expected result).

    The trouble is that xdm won't do it. I'm using a copy of xdm from (sorry, I couldn't find
a patch name or number on it !). Running a diff against the clean xdm
sources from[something]/R5untarred/mit/clients/xdm reveals
no significant changes to the xdmcp code - only to the login verification
code and some of the startup code.

    As far as possible,I've copied the configuration from the machines here,
which do exactly what I want already, but it doesn't seem to work - starting
the X server with 'X -indirect localhost' produces a chooser menu, and
selecting 'localhost' works as it should. Selecting anything else leads to
a blank screen for a while (whilst xdm times out) - with only the standard
gray backing pixmap and the 'X' cursor - and then the chooser menu pops up

    I'd be grateful if someone could possibly tell me what's going wrong
here, or if someone who has a system like this working could tar, gzip,
uuencode and email me the contents of their /usr/lib/X11/xdm directory,
and possibly also a copy of their 'xdm'.

    The same behaviour occurs with XFree86-2.0's supplied xdm.

    My configuration files are appended below. Replies by email are

     Thanks in advance,


---------------- configuration files -------------
[ these are all in /usr/lib/X11/xdm == /usr/X386/lib/X11/xdm ]

Xaccess begins {

%local localhost

*       CHOOSER %local %hostlist

Quote:} Xaccess ends.

Xresources begins {
xlogin*login.translations: #override\
        Ctrl<Key>R: abort-display()\n\
        <Key>F1: set-session-argument(failsafe) finish-field()\n\
        Ctrl<Key>Return: set-session-argument(failsafe) finish-field()\n\
        <Key>Return: set-session-argument() finish-field()
xlogin*borderWidth: 3
xlogin*greeting: Welcome to CLIENTHOST - XFree86 2.0 (X11R5)
xlogin*namePrompt: Please login:\
xlogin*fail: Login incorrect
#ifdef COLOR
xlogin*greetColor: Blue
xlogin*failColor: red
*Foreground: black
*Background: #fffff0
xlogin*Foreground: black
xlogin*Background: white

XConsole.text.geometry: 480x130
XConsole.verbose:       true
XConsole*iconic:        true
XConsole*font:          fixed

Chooser*geometry:               700x500+300+200
Chooser*allowShellResize:       false
Chooser*viewport.forceBars:     true
Chooser*font:                   9x15bold
Chooser*label.font:             *-new century schoolbook-bold-i-normal-*-240-*
Chooser*label.label:            XDMCP Host Menu  from CLIENTHOST
Chooser*list.font:              -*-*-medium-r-normal-*-*-230-*-*-c-*-iso8859-1
Chooser*Command.font:           *-new century schoolbook-bold-r-normal-*-180-*

Quote:} Xresources ends.

Xservers is of 0 length

Xsession is irrelevant, AFAIK - mail me and ask for it if you want -
it's big.

Xsetup begins {
/usr/bin/X11/xload -geometry 480x130+0-0 -fg "dark green" -bg white &
echo $! >/tmp/xdm-xload-pid
# Wibble wibble.
# /usr/bin/X11/xmodmap /usr/lib/X11/

Quote:} Xsetup ends

xdm-config begins {
DisplayManager*chooser:         /usr/X386/lib/X11/xdm/chooser
DisplayManager*errorLogFile:    /usr/X386/lib/X11/xdm/xdm-errors
DisplayManager*pidFile:         /usr/X386/lib/X11/xdm/xdm-pid
DisplayManager*keyFile:         /usr/X386/lib/X11/xdm/xdm-keys
DisplayManager*servers:         /usr/X386/lib/X11/xdm/Xservers
DisplayManager*accessFile:      /usr/X386/lib/X11/xdm/Xaccess
DisplayManager*authorize:       true
DisplayManager.removeDomainname: false
DisplayManager*terminateServer: TRUE
DisplayManager*authDir:         /usr/X386/lib/X11/xdm
!DisplayManager._0.authFile:     /usr/adm/xdm-auth._0
!DisplayManager._0.setup:       /usr/X386/lib/X11/xdm/Xsetup_0
!DisplayManager._0.startup:     /usr/X386/lib/X11/xdm/GiveConsole
DisplayManager._0.reset:        /usr/X386/lib/X11/xdm/TakeConsole
DisplayManager*resources:       /usr/X386/lib/X11/xdm/Xresources
DisplayManager*session:         /usr/X386/lib/X11/xdm/Xsession
DisplayManager*startup:         /usr/X386/lib/X11/xdm/Xstartup
DisplayManager*setup:           /usr/X386/lib/X11/xdm/Xsetup
DisplayManager*authComplain:    false

Quote:} xdm-config ends.

------------------ end config files ---------------

Silly XDMCP/xdm/Linux question -xdm won't issue xdmcp queries properly.

Post by Ian Jacks » Mon, 07 Mar 1994 02:13:03

>    [Crossposted because this is essentially a Linux question]

>  [...]   I've been trying to get my copy of xdm to display
>a local chooser which will allow me to connect to localhost and a number
>of foreign hosts via. xdmcp  [...]

There is a bug in the Linux version of the `chooser' program (in
/usr/X386-2.0/lib/X11/xdm/chooser); it appears to be unable to issue
correctly a remote direct xdmcp query.

I built my own version of the chooser from the sources (from but it didn't work any better.

Unfortunately I have very little knowledge of xdmcp or the workings of
xdm (which seemed to resemble spaghetti rather more than I would have
hoped), and I decided to give up on the problem and use a chooser on
another host.

Could someone familiar with xdmcp and/or the Linux networking code
look into this please ?

In the meantime I suggest you find an external machine to run the
chooser on and indirect through that; alternatively you could run two
X servers, one querying a local xdm and one a remote one.


2 Lexington Close, Cambridge, CB4 3LS, England;  phone: +44 223 64238


1. XDM: send an Indirect query via XDMCP

I need a way to send an Indirect query via XDMCP to the network from

I found a free PC X-server for windows-95, but the problem is it does
not broadcast anything when it starts.  So I cannot get xdm's
attention.  What I need is a win-95 program that can send an Indirect
query via XDMCP inorder to get xdm's attention and allow me to choose
the host to login to.

NOTE: currently I have all the PC's configured as local in the
Xservers file, and have to "kill -HUP" xdm when ever one wants to
login.  Also, this does not allow a chooser either.

Mark Dotson

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