## Gdmconfig Manual

2001
Trevor Curtis

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license can be found here.

Many of the names used by companies to distinguish their products and services are claimed as trademarks. Where those names appear in any GNOME documentation, and those trademarks are made aware to the members of the GNOME Documentation Project, the names have been printed in caps or initial caps.

This is version 1.0 of manual.

## Introduction

GDM Configurator, (GNOME Display Manager Configurator) is a configuration application for the GDM (Gnome Display Manager). Typically, when running your system in a graphical login mode, the GDM is the application that facilites logins. GDM Configurator allows for easy configuration of the GDM at various levels of detail. Customizations affect both operations and appearances.

To run GDM Configurator, select System GDM Configurator from the Main Menu, or type `gdmconfig` on the command line.

### Root access required

GDM Configurator requires root access to run.

GDM Configurator is included in the `Gnome-Core` package, which is part of the GNOME desktop environment. This document describes version &version; of GDM Configurator.

## Using Gnome Display Manager Configurator

GDM Configurator can be used to change the login apperance, and behaviour as well as security and environment options of the GDM to varying degrees of detail. This section describes basic usage of GDM Configurator.

### Basic usage

Starting GDM Configure opens the Main window, shown in . This window contains all options relating to the GDM's configuration.

#### GDM Configurator Main Window

GDM Configurator Main Window

### Toolbar

Toolbar Menus

#### The login appearance tab

The login appearance tab

#### Configuration

Revert settings

  Reset current changes to initial settings

Apply

  Apply current changes

#### Help

GDM Configurator users guide

  How to get this document from within GDM Configurator.

About...

  A little bit of kudos for all of the very hard working guys/gals who made it all possible

### Options

The Options box in the upper left hand corner controls the level of detail and customization offered on the tabs to its right. Below the Options box is a brief description of the level chosen, and what can be done in that level. The levels are explained below.

Basic

  This exposes the Login appearance, Login behaviour, and Face browser tabs to the right of the Options box.

Expert

  This exposes the Security, XDMCP, and X-server setup tabs to the right of the Options box.

System

  This exposes the Paths, Environment, and Chooser tabs to the right of the Options box.

#### Expert option and security

Enabling the expert option, allows for changes in GDM's security to be made. Improper configuration may lead to vulnerabilities for attackers.

#### System option and system health

Enabling the system option, allows for very specific changes which can impact the operation of your system. This option is only recommended for those who know exactly what they are doing.

## The Basic Options

Below are the options for the Login appearance, Login behaviour ,Face browser, and Automatic login tabs.

### Login appearance

  ### The login appearance tab

  The login appearance tab
Minimised Icon:

  Change the icon that represents the login screen when minimized.

Logo

  Change the image that is displayed in the login window

Gtk+ RC file

  Specify the location of `.gtkrc`

### Login behaviour

  ### The login behaviour tab

  The login behaviour tab
Quiver on failure

  If login fails, make the login window shake.

Exclude these users

  Do not show the users in the user menu, on the login box.

Default font:

  The font to display and default to.

Welcome message

  The text message to display in the login screen.

  ### Display machine name

  To have GDM display your machine name you can type &percnt;n in the Welcome message field, and it will always be replaced with whatever your machine's name is.

Background Program

  This allows you to run a given script, or application in the background whilst the login prompt is displayed.

Default locale

  The locale that should be set as default in the GDM

Lock position

  Lock the login box, such that it cannot be moved within the login screen.

Manually set position

  Allow for the login box to be moved manually within the login screen

X position

  The x coordinate for the login box placement

Y position

  The y coordinate for the login box placement

Xinerama screen

  This option allows one to specify on which monitor, in a multi-monitor setup, the GDM login screen will be displayed.

### Face browser

  ### The face browser tab

  The face browser tab
Show choosable user images

  Customization of user images in the face browser

Default face image

  Change the image used for default users in the face browser

Global faces directory

  The directory where the face images reside

Maximum face width

  The maximum width any given face image may be

Maximum face height

  The maximum height any given face image may be

### Background

  ### The background tab

  The background tab
Background type

  Selection of background type. Options are backgrounds by colour, image, or none at all.

Scale background image to fit

  Allow an image, if selected above, to be scaled to fit alloted space.

Only color on remote displays

  Enable a colour to be displayed only on remote systems

Background program

  Allow a program to be run in the background

### Automatic login

  ### The automatic login tab

  The automatic login tab
Login a user automatically on first bootup

  Enable logging in as the specified user when first starting the system.

Login a user automatically after a specified number of seconds.

  Allow the GDM to automatically login after the specified number of seconds using the specified user name.

Timed login

  The specified user to be used to login automaticaly.

Seconds before login

  The specified number of seconds before the GDM automatically logs in.

## The Expert Options

Below are the options for the Security , XDMCP, X-server setup, Login sessions, and Miscellaneous tabs.

### Security

  ### The security tab

  The security tab
Allow root to login with GDM

  Allow priviledged users, such as root, to login via the GDM.

  ### PAM supported systems

  On systems that support PAM, this option is ignored, and it becomes the responsiblity of the PAM libraries to determine whether the user will be on the local display or not.

Kill 'init' clients

  Allow the GDM to kill X clients that start from initialization scripts when a user logs in.

Authentication errors should be verbose

  Enable errors in authentication to be displayed to the user(s) in the GDM display.

Permissions:

  Determine the permission levels in relation to writable directories and files of other users. The World writable selection allows the GDM to view world writable files and directories. The Group writable selection allows the GDM to view only group writable files and directories. Finally, the Paranoia selection will only accept files and directories that the user owns.

GDM runs as this user

  Allows the GDM to be run as the specified user.

GDM runs as this group

  Allows the GDM to be run as the specified group.

User 'auth' directory

  Allow the directory which contains the user's .Xauthority file to be specified

User 'auth' FB directory

  In case the gdm fails to update the user's .Xauthority file, a cookie will be created in the specified directory.

User 'auth' File

  Specify the name of the file in which to store a user's cookies.

Retry delay

  Specify the number of seconds the GDM should wait before reactivating the entry field after a failed login attempt.

Maximum user file length

  Allows the maximum size of the largest readable/writable file to be specified. The GDM will refuse to read or write to a file bigger than the given value. The value is specified in bytes.

### XDMCP

  ### The XDMCP tab

  The XDMCP tab
Enable XDMCP

  Allow a remote X-terminal to request a session from the current host. Enabling this option makes visible the connection settings.(X Display Manager Control Protocol)

Honour indirect requests

  Enable choosing for X-terminals which don't supply their own display browser.

Listen on UDP port

  Listen to UDP(user datagram protocol) requests on the specified port.

Maximum pending requests

  Restrict the GDM to a fixed size queue of the specified pending connections.

  ### Denial of Service Attacks

  This option has been included to avoid DOS(Denial of Service Attacks). This parameter only limits the number of allowed displays initiating a connection at any one given time, and does not limit the number of total remote displays which can be managed.

Max pending indirect requests

  Allow only the specified number of displays with the host chooser at any one given time.

Maximum remote sessions

  Allow only the specified number of remote displays to be able to use the host.

Maximum wait time

  Wait for the specified amount of time in seconds before the requesting display is removed from the pending queue.

Maximum indirect wait time

  Wait for the specified amount of time, in seconds, between when a display requests a chooser and the completion of the protocol negotiation before removing display from the pending list.

Displays per host

  Specifies the number of displays that can run on any one host to be set.

Ping interval

  Specifies the interval, in minutes, that the gdm waits between issuing pings to make sure the display is still alive.

  Allows the specification of a script to run to set the willing headers sent by the manager.

### X-server setup

  ### The xserver setup tab

  The xserver setup tab
Servers

  Displays a list of server definitions. From the buttons on the right, one can create aliases for a specific server setup. Enabling a server as Flexible, indicates that the server can be started on demand.

Static Servers

  Allows the selection of servers which run always run. By picking one of the server definitions via the buttons on the right, one can setup the desired static server(s).

Always restart X servers

  Enable the X server to restart after every logout.

Standard X server

  Indicates the X server to be used and its respective path.

Xnest server

  Indicates the Xnest server to be used and its respective path.

Maximum number of flexible servers

  Indicates the maximum number of flexible servers, that may be running at any one given time.

Failsafe X server

  Indicates the Failsafe X server to be used and its respective path.

Script to run when X is crashing

  Indicates a script to run in the event on's X session keeps crashing.

X configurator binaries to try

  Indicates which binaries to use when an X session, or X itself, crashes.

### Login sessions

  ### The Login sessions tab

  The Login sessions tab
Session directory

  The directory that contains script(s) to be run at the begining of a session

Available Sessions

  List the available sessions in which to choose from. The selected session will appear in the Selected session name field. Under this field, the session script is displayed.

Gnome Chooser

  If a session named Gnome is present, enable the Gnome Chooser session to be displayed.

Gnome Failsafe

  Enable the Gnome Failsafe session to be displayed.

Xterm Failsafe

  Enable the Xterm Failsafe session to be displayed.

Enable debugging output

  Allow debugging information to be displayed

Add session

  Create and add a new session to be made available.

Remove session

  Delete the session selected in the Available Sessions menu.

Set as default

  Enable the selected session in the Available Sessions menu to be the default.

  ### Default session

  The current default session is indicated by a light blue highlight under the Available Sessions menu.

### Miscellaneous

  ### The Miscellaneous tab

  The Miscellaneous tab
Enable debugging output

  Enable the debugging output to be logged into the syslog file.

  ### Debug output to syslog

  Though a convieniant method to help track problems, this option, when selected, can fill up a system's log files rather quickly. This is not recommended for normal use

## The System Options

System menus

### Paths

  ### The paths tab

  The paths tab
Chooser command

  Allow selection and customization of the command that will activate the chooser.

Greeter command

  Allow selection and customization of the command that will activate the greeter.

Halt command

  Allow the specified command to halt the host machine

Reboot command

  Allow the specified command to reboot the host machine

Display initialization directory

  Display the directory that contains the scripts needed for the GDM initilization.

Logging directory

  Output logging information into a file(s) residing in the specified directory.

Session directory

  Set the specified directory as the directory that contains the scripts to start a session.

PRE session scripts directory

  Look for scripts in the specified directory to run before starting a session.

POST session scripts directory

  Look for scripts in the specified directory to run after ending a session.

PID file

  Place the PID file(s) in the specified directory

### Environment

  ### The environment tab

  The environment tab
Default $PATH

  Set the default PATH variable ($PATH)

Root $PATH

  Set the PATH of the Root user to the specified directories.

Locale file

  Set the specified file as the main locale file.

### Chooser

  ### The chooser tab

  The chooser tab
Directory for host images

  Set the specified directory as the directory to contain the images to represent hosts.

Default host image

  Set the selected image as the default image to represent hosts.

Scan every 'x' seconds

  Select the number of seconds after which host images are scanned

## Known Bugs and Limitations

This application has no known bugs.

## Authors

GDM Configure was written by Lee Mallabone (lee@fonicmonkey.net). To find more information about GDM Configure, please visit the MY-GNOME-APP Web page. Please send all comments, suggestions, and bug reports to the GNOME bug tracking database. (Instructions for submitting bug reports can be found on-line.) You can also use Bug Report Tool (`bug-buddy`), available in the Utilities submenu of Main Menu, for submitting bug reports.

This manual was written by Trevor Curtis (tcurtis@somaradio.ca). Please send all comments and suggestions regarding this manual to the GNOME Documentation Project by sending an email to docs@gnome.org. You can also add your comments online by using the GNOME Documentation Status Table.

## License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

A copy of the GNU General Public License is included as an appendix to the GNOME Users Guide. You may also obtain a copy of the GNU General Public License from the Free Software Foundation by visiting their Web site or by writing to

        Free Software Foundation, Inc.
        59 Temple Place - Suite 330
        Boston, MA 02111-1307
        USA