# GNOMEren pantaila-kudeatzailearen erreferentzia-eskuliburua

## Eskuliburu honetan erabilitako terminoak eta konbentzioak

GNOME GDMren 2.26.0 bertsioa azaltzen da eskuliburu honetan. Azken eguneratzea 2009ko urriaren 2an izan zen.

Aukeratzailea - Lotutako monitorean urruneko monitore bat kudeatzeko balio duen urruneko ostalari bat hautatzeko erabiltzen den programa bat (`gdm-host-chooser`).

FreeDesktop - Mahaigainerako estandarrak eskaintzen dituen erakundea. Adibidez, GDM aplikazioak erabilitako Desktop Entry Specification sortu du. https://www.freedesktop.org/.

GDM - GNOMEren pantaila-kudeatzailea. Software-paketea bere osotasunean deskribatzeko erabiltzen da.

Ongietorria - Saioa hasteko leiho grafikoa (`gnome-shell` komandoak eskainitakoa).

PAM - Pluggable Authentication Mechanism

XDMCP - X Display Manage Protocol

Xserver - X leiho-sistemaren inplementazio bat. Adibidez, X.org fundazioak eskaintzen duen Xorg Xserver https://www.x.org.

Kortxete barruan dagoen hitz batekin hasten diren bide-izenak instalazio-aurrizkiarekiko erlatiboak dira. Adibidez, `<share>/pixmaps/` helbideak `/usr/share/pixmaps` helbideari egiten dio erreferentzia GDM `--prefix=/usr` komandoarekin konfiguratu bada.

## Ikuspegi orokorra

### Sarrera

GNOMEren pantaila-kudeatzailea (GDM) pantaila fisikoki konektatuak zein urrunekoak kudeatzeko behar diren eginbide guztiak dituen pantaila-kudeatzaile bat da. GDM zerotik idatzi da eta ez du inolako XDM edo X Consortium erakundearen koderik.

Kontuan izan GDM moldagarria dela, eta konfigurazio-ezarpen horietako askok segurtasunean eragina dutela. Dokumentu honetan kontuan hartu beharreko zenbait auzi nabarmendu dira.

Kontuan izan zenbait sistema eragilek GDM desberdin konfiguratzen dutela eta dokumentu honetan deskribatzen diren balio lehenetsiak beste batzuk direla. GDM ez bada portatzen hemen dokumentatu bezala, begiratu ea konfigurazioren bat hemen esandakoaren desberdina den.

GDMri buruzko informazio gehiagorako, begiratu proiektuaren webgunean: https://wiki.gnome.org/Projects/GDM.

GDMri buruzko eztabaida edo kontsultetarako, begiratu eztabaida-foroa: https://discourse.gnome.org/tag/gdm. Aurreko posta-zerrendaren artxiboa ere galdera ohikoenentzako erantzunak bilatzeko toki ona da. Zerrendaren artxiboa https://mail.gnome.org/archives/gdm-list/ helbidean dago eta mezuak gako-hitzen bidez bilatzeko bilaketa-sistema bat du.

Akatsen bat jakinarazi nahi baduzu edo hobekuntzaren bat eskatu nahi baduzu, jo https://gitlab.gnome.org/GNOME/gdm/-/issues/ helbidera.

### Interfazearen egonkortasuna

GDM 2.220 eta zaharragoek konfigurazio-interfaze egonkorrak onartzen zituzten. Hala ere, kode-oinarri erabat berridatzi zen GDM 2.22 bertsiorako eta ez da erabat bateragarria bertsio zaharragoekin. Orain gauzek beste modu batean funtzionatzen dute eta zenbait aukerak ez dute zentzurik, bai aukera horietako batzuek inoiz ez dutelako zentzurik izan, bai zenbait funtzionaltasun oraindik ez direlako inplementatu.

Oraindik ere modu egonkorrean onartzen diren interfazeetako batzuk Init, PreSession, PostSession, PostLogin eta Xsession scriptak dira. `<etc>/gdm/custom.conf` fitxategiko zenbait daemon-en konfigurazio-aukerak ere onartzen dira oraindik. Era berean, `~/.dmrc` eta aurpegiak arakatzeko irudien kokalekuak ere onartzen dira.

GDM 2.20 eta bertsio zaharragoek pantaila anitz txartel grafiko desberdinekin kudeatzeko gaitasuna zuten, adibidez terminal-zerbitzarien inguruneetan erabiltzeko Xnest, Xephyr edo antzeko beste programa baten bidez leiho batean saioa hasi zezaketen, gdmsetup programa zuten, XMLn oinarritutako ongietorri-gaiak zituzten eta XDMCP aukeratzailea exekutatu zezaketen saioa hasteko pantailatik. Eginbide horiek ez ziren mantendu 2.22 bertsioa idatzi zenean..

### Deskribapen funtzionala

GDMk sistemako pantailak kudeatzen ditu. Horretarako, erabiltzaileak autentifikatzen ditu, erabiltzaile-saioak abiarazten ditu eta haiek amaitzen ditu. GDM konfiguratu egin daiteke. Dokumentu honen "GDM konfiguratzea" atalean horretarako moduak deskribatu dira. Ezgaitasunak dituzten erabiltzaileek ere erabili dezakete GDM.

GDM erabiliz, kontsolaren pantaila nagusia kudeatu daiteke, eta baita terminal birtualen bidez abiarazitako pantailak ere. Beste aplikazio batzuekin integratuta dago, adibidez User Switch Applet (FUSA) eta gnome-screensaver aplikazioekin, Xserver Virtual Terminal (VT) interfazearen bidez kontsolaren pantaila anitz kudeatzeko. XDMCP pantailak ere kudeatu ditzake.

Pantaila mota dena delakoa izanda, GDMk Xserver prozesu bat abiaraziko du, `Init` scripta exekutatuko du erro-erabiltzaile gisa eta ongietorri-aplikazioa abiaraziko du pantailan.

Ongietorri-programa hau pribilegiorik gabeko "gdm" erabiltzaile/talde gisa exekutatzen da. Erabiltzaile eta talde hori dokumentu honetako "Segurtasuna" atalean deskribatuta dago. Ongietorri-programaren funtzio nagusiak dira saioa hasteko kontu bat hautatzeko mekanismo bat ematea eta erabiltzailearen eta sistemaren arteko mezu-trukea bideartzea kontu horrekin autentifikatzean. Autentifikazio-prozesuak Pluggable Authentication Modules (PAM) darabil. PAM moduluek zehazten dute zein gonbit erakusten zaion erabiltzaileari (horrelakorik erakusten bada) autentifikazioa gauzatzeko. Sistema estandarretan ongietorri-programak erabiltzaile-izen bat eta pasahitz bat eskatuko ditu autentifikaziorako. Hala ere, zenbait sistema mekanismo gehigarriak (hatz-marka, txartel adimendunak...) erabiltzeko konfiguratu daitezke. GDM ordezko horiek onartzeko konfiguratu daiteke, aldi beren ongietorri-saioaren hedapenak eta `--enable-split-authentication` `./configure` aukerak erabiliz, edo bakoitzean haietako bat eskainiz sistemaren PAM konfigurazioen bidez.

Txartel adimendunaren hedapena gaitu edo desgaitzeko, erabili gsettings-eko `org.gnome.display-manager.extensions.smartcard.active` gakoa.

Era berean, hatz-markaren hedapena gaitu edo desgaitzeko, erabili gsettings-eko `org.gnome.display-manager.extensions.fingerprint.active` gakoa.

GDM eta PAM sarrerarik behar ez izateko konfiguratu daitezke. Horrela, GDMk automatikoki hasi dezake saioa. Modu hori interesgarria izan daiteke zenbait ingurunetan, adibidez kiosko motako sistemetan edo erabiltzaile bakarra dagoenean.

Autentifikazioaz gain, ongietorri-programaren bidez erabiltzaileak zein saio hasi eta zein hizkuntza erabili aukeratu dezake. Saioak .desktop atzizkiarekin amaitzen diren fitxategien bidez definituta daude. Fitxategi horiei buruzko informazio gehiagorako, begiratu dokumentu honetako "GDM erabiltzaile-saioa eta hizkuntza-konfigurazioa" atala. Lehenespenez, GDM aurpegi-arakatzaile bat erakusteko konfiguratuta dago, erabiltzaileak bere izena idatzi behar izan gabe irudi batean klik eginez aukeratu ahal dezan bere kontua. GDMk erabiltzailearen saio eta hizkuntza lehenetsia gordetzen du erabiltzailearen `~/.dmrc` fitxategian, eta lehenespen horiek erabiliko ditu erabiltzaileak ez badu saio edo hizkuntza bat aukeratzen saioa hasteko interfazean.

After authenticating a user, the daemon runs the `PostLogin` script as root, then runs the `PreSession` script as root. After running these scripts, the user session is started. When the user exits their session, the `PostSession` script is run as root. These scripts are provided as hooks for distributions and end-users to customize how sessions are managed. For example, using these hooks you could set up a machine which creates the user's $HOME directory on the fly, and erases it on logout. The difference between the `PostLogin` and `PreSession` scripts is that `PostLogin` is run before the pam_open_session call so is the right place to do anything which should be run before the user session is initialized. The `PreSession` script is called after session initialization.

### Ongietorriaren panela

The GDM greeter program displays a panel docked at the bottom of the screen which provides additional functionality. When a user is selected, the panel allows the user to select which session, language, and keyboard layout to use after logging in. The keyboard layout selector also changes the keyboard layout used when typing your password. The panel also contains an area for login services to leave status icons. Some example status icons include a battery icon for current battery usage, and an icon for enabling accessibility features. The greeter program also provides buttons which allow the user to shutdown or restart the system. It is possible to configure GDM to not provide the shutdown and restart buttons, if desired. GDM can also be configured via PolicyKit (or via RBAC on Oracle Solaris) to require the user have appropriate authorization before accepting the shutdown or restart request.

Kontuan izan teklatu-diseinuaren eginbidea libxklavier onartzen duten sistemetan soilik dagoela erabilgarri.

### Erabilerraztasuna

GDM supports "Accessible Login", allowing users to log into their desktop session even if they cannot easily use the screen, mouse, or keyboard in the usual way. Accessible Technology (AT) features such as an on-screen keyboard, screen reader, screen magnifier, and Xserver AccessX keyboard accessibility are available. It is also possible to enable large text or high contrast icons and controls, if needed. Refer to the "Accessibility Configuration" section of the document for more information how various accessibility features can be configured.

Zenbait sistema eragiletan, beharrezkoa da GDM erabiltzailea "auido" taldeko kide izatea audio-irteera behar duten AT programek (adibidez, testua ahots bihurtzen dutenek) funtzionatu dezaten.

### GDM aurpegi-arakatzailea

The Face Browser is the interface which allows users to select their username by clicking on an image. This feature can be enabled or disabled via the org.gnome.login-screen disable-user-list GSettings key and is on by default. When disabled, users must type their complete username by hand. When enabled, it displays all local users which are available for login on the system (all user accounts defined in the /etc/passwd file that have a valid shell and sufficiently high UID) and remote users that have recently logged in. The face browser in GDM 2.20 and earlier would attempt to display all remote users, which caused performance problems in large, enterprise deployments.

Aurpegi-arakatzailea gehienetan saioa hasten duten erabiltzaileak zerrendaren goiko aldean erakusteko konfiguratuta dago. Horrela, sarritan saio hasten duten erabiltzaileak azkarrago aurkituko dute saioa hasteko irudia.

Aurpegi-arakatzaileak "bilatu idatzi ahala" onartzen du. Horrek esan nahi du dinamikoki mugituko duela aurpegien hautapena erabiltzaileak izena zerrendan idatzi ahala. Horrek esan nahi du erabiltzaile-izen luzeagoa duen erabiltzaile batek hasierako karaktere gutxi batzuk soilik idatzi beharko dituela zerrendako elementu zuzena hautatua izateko.

The icons used by GDM can be installed globally by the sysadmin or can be located in the user's home directories. If installed globally they should be in the `<share>/pixmaps/faces/` directory and the filename should be the name of the user. Face image files should be a standard image that GTK+ can read, such as PNG or JPEG. Face icons placed in the global face directory must be readable to the GDM user.

Erabiltzaileak ez badu ikono globalik, GDMk erabiltzailearen $HOME direktorioan bilatuko du irudi-fitxategia. GDMk lehenengo `~/.face` kokalekuan bilatuko du aurpegiaren irudia. Aurkitzen ez badu, `~/.face.icon` begiratuko du. Horrela ere aurkitzen ez badu, "face/picture=" in the `~/.gnome2/gdm` fitxategian definitutako balioa erabiliko du.

Erabiltzaileak ez badu aurpegi-irudirik definituta, GDMk uneko GTK+ gaian definitutako "stock_person" ikonoa erabiliko du. Hori ere definitu gabe badago, aurpegi-irudi generiko bat erabiliko da.

Kontuan izan aurpegi-ikonoak kargatzeak eta eskalatzeak denbora behar duela haiek urruneko erabiltzaile-direktoriotan badaude. NIS edo NFS bidez irudiak kargatzea ez denez oso praktikoa, GDM ez da saiatuko urruneko direktorioetako aurpegi-irudiak kargatzen.

Arakatzailea aktibatuta dagoenean, ordenagailuko baliozko erabiltzaile-izenak mundu guztiari erakutsiko zaizkio. XDMCP gaituta badago, erabiltzaile-izenak urruneko erabiltzaileei erakutsiko zaizkie. Horrek segurtasuna mugatzen du, erabiltzaile gaizto batek ez baitu erabiltzaile-izena asmatu behar izango. Segurtasun handiko inguruneetan ez da oso egokia aurpegi-arakatzailea erabiltzea.

### XDMCP

The GDM daemon can be configured to listen for and manage X Display Manage Protocol (XDMCP) requests from remote displays. By default XDMCP support is turned off, but can be enabled if desired. If GDM is built with TCP Wrapper support, then the daemon will only grant access to hosts specified in the GDM service section in the TCP Wrappers configuration file.

GDMk zenbait neurri ditu XDMCP zerbitzuaren gaineko zerbitzu-ukapeneko erasoen aurrean gogorragoak izateko. Protokolo-parametroak, diosalen denbora-mugak eta beste hainbat moldatu daitezke horretarako. Konfigurazio lehenetsiak ongi funtzionatuko du sistema gehienetan.

GDM by default listens for XDMCP requests on the normal UDP port used for XDMCP, port 177, and will respond to QUERY and BROADCAST_QUERY requests by sending a WILLING packet to the originator.

GDM can also be configured to honor INDIRECT queries and present a host chooser to the remote display. GDM will remember the user's choice and forward subsequent requests to the chosen manager. GDM also supports an extension to the protocol which will make it forget the redirection once the user's connection succeeds. This extension is only supported if both daemons are GDM. It is transparent and will be ignored by XDM or other daemons that implement XDMCP.

XDMCPk ez badu funtzionatzen, ziurtatu makina guztiak `/etc/hosts` fitxategian ageri direla.

Begiratu "Segurtasuna" atala XDMCP erabiltzean egon daitezkeen segurtasun-kezkei buruzko informazioa eskuratzeko.

### Egunkaria

GDMk syslog darabil erroreen eta egoeren erregistrorako. Arazketa-informazioa ere erregistratu dezake. GDMk ongi funtzionatzen ez badu, mezu horiek garrantzitsuak izan daitezke arazoen jatorria ezagutzeko. Arazketa-irteera gaitzeko, ezarri `<etc>/gdm/custom.conf` fitxategiko araztu/Gaitu gakoan "true" balioa.

Output from the various Xservers is stored in the GDM log directory, which is normally `<var>/log/gdm/`. Any Xserver messages are saved to a file associated with the display value, `<display>.log`.

The session output is piped through the GDM daemon to the `~/`$XDG_CACHE_HOME`/gdm/session.log` file which usually expands to `~/.cache/gdm/session.log`. The file is overwritten on each login, so logging out and logging back into the same user via GDM will cause any messages from the previous session to be lost.

Kontuan izan GDMk ezin badu fitxategi hori sortu, ordezko fitxategi bat sortuko dela `~/`$XDG_CACHE_HOME`/gdm/session.log.XXXXXXXX` izenarekin, non `XXXXXXXX` ausazko zenbait karaktere diren.

### Erabiltzaileen txandakatze azkarra

GDMren bidez erabiltzaile bat baino gehiagok eduki dezake saioa hasita aldi berean. Erabiltzaile batek saioa hasi ondoren, gainerako erabiltzaileek GNOMEren paneleko erabiltzaile-aldatzailearen bidez hasi dezakete beren saioak, edo GNOMEren pantaila-babeslearen 'Blokeatu pantaila' elkarrizketa-koadroko 'Aldatu erabiltzailez' botoiaren bidez. Saio aktibo batetik beste batera igarotzeko, erabili mekanismo bera. Kontuan izan zenbait banaketak ez dutel erabiltzaile-aldatzailea gehitzen panel-konfigurazio lehenetsian. Panelaren testuinguru-menua erabiliz gehitu daiteke.

Kontuan izan eginbide hau terminal birtualak onartzen dituzten sistemetan dagoela soilik. Eginbide honek ez du funtzionatuko terminal birtualak erabilgarri ez badaude.

## Segurtasuna

### GDM erabiltzailea eta taldea

For security reasons a dedicated user and group id are recommended for proper operation. This user and group are normally "gdm" on most systems, but can be configured to any user or group. All GDM GUI programs are run as this user, so that the programs which interact with the user are run in a sandbox. This user and group should have limited privilege.

The only special privilege the "gdm" user requires is the ability to read and write Xauth files to the `<var>/run/gdm` directory. The `<var>/run/gdm` directory should have root:gdm ownership and 1777 permissions.

You should not, under any circumstances, configure the GDM user/group to a user which a user could easily gain access to, such as the user `nobody`. Any user who gains access to an Xauth key can snoop on and control running GUI programs running in the associated session or perform a denial-of-service attack on it. It is important to ensure that the system is configured properly so that only the "gdm" user has access to these files and that it is not easy to login to this account. For example, the account should be setup to not have a password or allow non-root users to login to the account.

The GDM greeter configuration is stored in GConf. To allow the GDM user to be able to write configuration, it is necessary for the "gdm" user to have a writable $HOME directory. Users may configure the default GConf configuration as desired to avoid the need to provide the "gdm" user with a writable $HOME directory. However, some features of GDM may be disabled if it is unable to write state information to GConf configuration.

### PAM

GDMk PAM erabiltzen du saio-hasierako autentifikaziorako. Pluggable Authentication Module da PAM akronimoaren esanahia, eta ordenagailuan autentifikatzea behar duten aplikazio askok erabiltzen dute. Administratzaileak autentifikazio-portaera zehatzak konfiguratu ditzake haren bidez, saio-hasiera programa desberdinek (ssh-k, pantaila-babesleak, saioa hasteko interfazeak) erabili dezaten.

PAM is complicated and highly configurable, and this documentation does not intend to explain this in detail. Instead, it is intended to give an overview of how PAM configuration relates with GDM, how PAM is commonly configured with GDM, and known issues. It is expected that a person needing to do PAM configuration would need to do further reading of PAM documentation to understand how to configure PAM and to understand terms used in this section.

PAM configuration has different, but similar, interfaces on different Operating Systems, so check the pam.d or pam.conf man page for details. Be sure you read the PAM documentation and are comfortable with the security implications of any changes you intend to make to your configuration.

Note that, by default, GDM uses the "gdm" PAM service name for normal login and the "gdm-autologin" PAM service name for automatic login. These services may not be defined in your pam.d or pam.conf configured file. If there is no entry, then GDM will use the default PAM behavior. On most systems this should work fine. However, the automatic login feature may not work if the gdm-autologin service is not defined.

The `PostLogin` script is run before pam_open_session is called, and the `PreSession` script is called after. This allows the system administrator to add any scripting to the login process either before or after PAM initializes the session.

If you wish to make GDM work with other types of authentication mechanisms (such as a fingerprint or SmartCard reader), then you should implement this by using a PAM service module for the desired authentication type rather than by trying to modify the GDM code directly. Refer to the PAM documentation on your system.

PAM does have some limitations regarding being able to work with multiple types of authentication at the same time, like supporting the ability to accept either SmartCard and the ability to type the username and password into the login program. There are techniques that are used to make this work, and it is best to research how this problem is commonly solved when setting up such a configuration.

If automatic login does not work on a system, check to see if the "gdm-autologin" PAM stack is defined in the PAM configuration. For this to work, it is necessary to use a PAM module that simply does no authentication, or which simply returns PAM_SUCCESS from all of its public interfaces. Assuming your system has a pam_allow.so PAM module which does this, a PAM configuration to enable "gdm-autologin" would look like this:

           gdm-autologin auth  required    pam_unix_cred.so.1
           gdm-autologin auth  sufficient  pam_allow.so.1
           gdm-autologin account  sufficient  pam_allow.so.1
           gdm-autologin session  sufficient  pam_allow.so.1
           gdm-autologin password  sufficient  pam_allow.so.1

The above setup will cause no lastlog entry to be generated. If a lastlog entry is desired, then use the following for the session:

           gdm-autologin session required pam_unix_session.so.1

If the computer is used by several people, which makes automatic login unsuitable, you may want to allow some users to log in without entering their password. This feature can be enabled as a per-user option in the users-admin tool from the gnome-system-tools; it is achieved by checking that the user is member a Unix group called "nopasswdlogin" before asking for a password. For this to work, the PAM configuration file for the "gdm" service must include a line such as:

          gdm auth  sufficient  pam_succeed_if.so  user ingroup nopasswdlogin

### utmp eta wtmp

GDM generates utmp and wtmp User Accounting Database entries upon session login and logout. The utmp database contains user access and accounting information that is accessed by commands such as `finger`, `last`, `login`, and `who`. The wtmp database contains the history of user access and accounting information for the utmp database. Refer to the utmp and wtmp man pages on your system for more information.

### Xserver autentifikazio-eskema

Xserver authorization files are stored in a newly created subdirectory of `<var>/run/gdm` at start up. These files are used to store and share a "password" between X clients and the Xserver. This "password" is unique for each session logged in, so users from one session can't snoop on users from another.

GDM only supports the MIT-MAGIC-COOKIE-1 Xserver authentication scheme. Normally little is gained from the other schemes, and no effort has been made to implement them so far. Be especially careful about using XDMCP because the Xserver authentication cookie goes over the wire as clear text. If snooping is possible, then an attacker could simply snoop your authentication password as you log in, regardless of the authentication scheme being used. If snooping is possible and undesirable, then you should use ssh for tunneling an X connection rather then using XDMCP. You could think of XDMCP as a sort of graphical telnet, having the same security issues. In most cases, ssh -Y should be preferred over GDM's XDMCP features.

### XDMCP segurtasuna

Even though your display is protected by cookies, XEvents and thus keystrokes typed when entering passwords will still go over the wire in clear text. It is trivial to capture these.

XDMCP is primarily useful for running thin clients such as in terminal labs. Those thin clients will only ever need the network to access the server, and so it seems like the best security policy to have those thin clients on a separate network that cannot be accessed by the outside world, and can only connect to the server. The only point from which you need to access outside is the server. This type of set up should never use an unmanaged hub or other sniffable network.

### XDMCP sarbide-kontrola

XDMCP access control is done using TCP wrappers. It is possible to compile GDM without TCP wrapper support, so this feature may not be supported on some Operating Systems.

You should use the daemon name `gdm` in the `<etc>/hosts.allow` and `<etc>/hosts.deny` files. For example to deny computers from `.evil.domain` from logging in, then add

    gdm: .domeinu.gaiztoa

to `<etc>/hosts.deny`. Hurrengoa ere gehitu beharko duzu agian

    gdm: .zure-domeinua

to your `<etc>/hosts.allow` if you normally disallow all services from all hosts. See the hosts.allow(5) man page for details.

### Suebaki-segurtasuna

Even though GDM tries to outsmart potential attackers trying to take advantage of XDMCP, it is still advised that you block the XDMCP port (normally UDP port 177) on your firewall unless really needed. GDM guards against denial of service attacks, but the X protocol is still inherently insecure and should only be used in controlled environments. Also each remote connection takes up lots of resources, so it is much easier to do a denial of service attack via XDMCP than attacking a webserver.

It is also wise to block all of the Xserver ports. These are TCP ports 6000+ (one for each display number) on your firewall. Note that GDM will use display numbers 20 and higher for flexible on-demand servers.

X ez da oso protokolo segurua interneten erabiltzeko, eta XDMCP segurtasun gutxiagokoa da.

### PolicyKit

GDM PolicyKit erabiltzeko konfiguratu daiteke, sistema-administratzaileak saioa hasteko pantailak itzaltzeko eta berrabiarazteko botoiak erakutsiko duen ala ez kontrolatu dezan.

These buttons are controlled by the `org.freedesktop.consolekit.system.stop-multiple-users` and `org.freedesktop.consolekit.system.restart-multiple-users` actions respectively. Policy for these actions can be set up using the polkit-gnome-authorization tool, or the polkit-auth command line program.

### RBAC (Egitekoetan Oinarritutako Sarbide-Kontrola)

GDM may be configured to use RBAC instead of PolicyKit. In this case the RBAC configuration is used to control whether the login screen should provide the shutdown and restart buttons on the greeter screen.

For example, on Oracle Solaris, the "solaris.system.shutdown" authorization is used to control this. Simply modify the `/etc/user_attr` file so that the "gdm" user has this authorization.

## ConsoleKit euskarria

GDM includes support for publishing user login information with the user and login session accounting framework known as ConsoleKit. ConsoleKit is able to keep track of all the users currently logged in. In this respect, it can be used as a replacement for the utmp or utmpx files that are available on most Unix-like Operating Systems.

When GDM is about to create a new login process for a user it will call a privileged method of ConsoleKit in order to open a new session for this user. At this time GDM also provides ConsoleKit with information about this user session such as: the user ID, the X11 Display name that will be associated with the session, the host-name from which the session originates (useful in the case of an XDMCP session), whether or not this session is attached, etc. As the entity that initiates the user process, GDM is in a unique position to know about the user session and to be trusted to provide these bits of information. The use of this privileged method is restricted by the use of the D-Bus system message bus security policy.

In case a user with an existing session has authenticated at GDM and requests to resume that existing session, GDM calls a privileged method of ConsoleKit to unlock that session. The exact details of what happens when the session receives this unlock signal are undefined and session-specific. However, most sessions will unlock a screensaver in response.

When the user chooses to log out, or if GDM or the session quit unexpectedly the user session will be unregistered from ConsoleKit.

## Konfigurazioa

GDM has a number of configuration interfaces. These include scripting integration points, daemon configuration, greeter configuration, general session settings, integration with gnome-settings-daemon configuration, and session configuration. These types of integration are described in detail below.

### Scriptgintza integratzeko puntuak

GDM-n scriptak integratzeko puntuak `<etc>/gdm/` direktorioan daude:

    Xsession
    Init/
    PostLogin/
    PreSession/
    PostSession/

The `Init`, `PostLogin`, `PreSession`, and `PostSession` scripts all work as described below.

For each type of script, the default one which will be executed is called "Default" and is stored in a directory associated with the script type. So the default `Init` script is `<etc>/gdm/Init/Default`. A per-display script can be provided, and if it exists it will be run instead of the default script. Such scripts are stored in the same directory as the default script and have the same name as the Xserver DISPLAY value for that display. For example, if the `<Init>/:0` script exists, it will be run for DISPLAY ":0".

All of these scripts are run with root privilege and return 0 if run successfully, and a non-zero return code if there was any failure that should cause the login session to be aborted. Also note that GDM will block until the scripts finish, so if any of these scripts hang, this will cause the login process to also hang.

When the Xserver for the login GUI has been successfully started, but before the login GUI is actually displayed, GDM will run the `Init` script. This script is useful for starting programs that should be run while the login screen is showing, or for doing any special initialization if required.

After the user has been successfully authenticated GDM will run the `PostLogin` script. This is done before any session setup has been done, including before the pam_open_session call. This script is useful for doing any session initialization that needs to happen before the session starts. For example, you might setup the user's $HOME directory if needed.

After the user session has been initialized, GDM will run the `PreSession` script. This script is useful for doing any session initialization that needs to happen after the session has been initialized. It can be used for session management or accounting, for example.

When a user terminates their session, GDM will run the `PostSession` script. Note that the Xserver will have been stopped by the time this script is run, so it should not be accessed.

Note that the `PostSession` script will be run even when the display fails to respond due to an I/O error or similar. Thus, there is no guarantee that X applications will work during script execution.

All of the above scripts will set the `$RUNNING_UNDER_GDM` environment variable to `yes`. If the scripts are also shared with other display managers, this allows you to identify when GDM is calling these scripts, so you can run specific code when GDM is used.

### Hasiera automatikoaren konfigurazioa

The `<share>/gdm/autostart/LoginWindow` directory contains files in the format specified by the "FreeDesktop.org Desktop Application Autostart Specification". Standard features in the specification may be used to specify programs that should auto-restart or only be launched if a GConf configuration value is set, etc.

Any `.desktop` files in this directory will cause the associated program to automatically start with the login GUI greeter. By default, GDM is shipped with files which will autostart the gdm-simple-greeter login GUI greeter itself, the gnome-power-manager application, the gnome-settings-daemon, and the metacity window manager. These programs are needed for the greeter program to work. In addition, desktop files are provided for starting various AT programs if the configuration values specified in the Accessibility Configuration section below are set.

### Xsession scripta

There is also an `Xsession` script located at `<etc>/gdm/Xsession` which is called between the `PreSession` and the `PostSession` scripts. This script does not support per-display like the other scripts. This script is used for actually starting the user session. This script is run as the user, and it will run whatever session was specified by the Desktop session file the user selected to start.

### Daemon-konfigurazioa

The GDM daemon is configured using the `<etc>/gdm/custom.conf` file. Default values are stored in GConf in the `gdm.schemas` file. It is recommended that end-users modify the `<etc>/gdm/custom.conf` file because the schemas file may be overwritten when the user updates their system to have a newer version of GDM.

Note that older versions of GDM supported additional configuration options which are no longer supported in the latest versions of GDM.

The `<etc>/gdm/custom.conf` file is in the `keyfile` format. Keywords in brackets define group sections, strings before an equal sign (=) are keys and the data after equal sign represents their value. Empty lines or lines starting with the hash mark (#) are ignored.

The file `<etc>/gdm/custom.conf` supports the "[daemon]", "[security]", and "[xdmcp]" group sections. Within each group, there are particular key/value pairs that can be specified to modify how GDM behaves. For example, to enable timed login and specify the timed login user to be a user named "you", you would modify the file so it contains the following lines:

    [daemon]
    TimedLoginEnable=true
    TimedLogin=you

Ondoren, onartutako konfigurazio-gakoen zerrenda bat:

#### [chooser]

Multicast

-     Multicast=false

  Egia bada eta IPv6 gaituta badago, aukeratzaileak multidifusioko kontsulta bat bidaliko dio sare lokalari eta multidifusioaren taldearekin bat egin duten ostalarien erantzunak bilduko ditu.

MulticastAddr

-     MulticastAddr=ff02::1

  Hau Link-local multidifusioko helbidea da.

#### [daemon]

TimedLoginEnable

-     TimedLoginEnable=false

  If the user given in `TimedLogin` should be logged in after a number of seconds (set with `TimedLoginDelay`) of inactivity on the login screen. This is useful for public access terminals or perhaps even home use. If the user uses the keyboard or browses the menus, the timeout will be reset to `TimedLoginDelay` or 30 seconds, whichever is higher. If the user does not enter a username but just hits the ENTER key while the login program is requesting the username, then GDM will assume the user wants to login immediately as the timed user. Note that no password will be asked for this user so you should be careful, although if using PAM it can be configured to require password entry before allowing login. Refer to the "Security->PAM" section of the manual for more information, or for help if this feature does not seem to work.

TimedLogin

-     TimedLogin=

  This is the user that should be logged in after a specified number of seconds of inactivity.

  If the value ends with a vertical bar | (the pipe symbol), then GDM will execute the program specified and use whatever value is returned on standard out from the program as the user. The program is run with the DISPLAY environment variable set so that it is possible to specify the user in a per-display fashion. For example if the value is "/usr/bin/getloginuser|", then the program "/usr/bin/getloginuser" will be run to get the user value.

TimedLoginDelay

-     TimedLoginDelay=30

  Atzerapena, segundotan, `TimedLogin` erabiltzailearen saioa hasi baino lehen.

AutomaticLoginEnable

-     AutomaticLoginEnable=false

  Egia bada, `AutomaticLogin` atalean emandako erabiltzailearen saioa berehala hasiko da. Eginbide hau denboraren araberako saio-hasieran 0 segundoko balioa ezartzea bezalakoa da.

AutomaticLogin

-     AutomaticLogin=

  Hau `AutomaticLoginEnable` egia bada berehala hasiko den erabiltzailea da.

  If the value ends with a vertical bar | (the pipe symbol), then GDM will execute the program specified and use whatever value is returned on standard out from the program as the user. The program is run with the DISPLAY environment variable set so that it is possible to specify the user in a per-display fashion. For example if the value is "/usr/bin/getloginuser|", then the program "/usr/bin/getloginuser" will be run to get the user value.

User

-     User=gdm

  Ongietorria eta erabiltzaile-interfaze grafikodun beste aplikazio batzuk exekutatzeko erabiltzen duten erabiltzaile-izena. Begiratu `User` konfigurazio-gakoa eta dokumentu honen "Segurtasuna->GDM erabiltzailea eta taldea" atala informazio gehiagorako.

Group

-     Group=gdm

  Ongietorria eta erabiltzaile-interfaze grafikodun beste aplikazio batzuk exekutatzeko erabiltzen duten talde-izena. Begiratu `User` konfigurazio-gakoa eta dokumentu honen "Segurtasuna->GDM erabiltzailea eta taldea" atala informazio gehiagorako.

#### Arazketa-aukerak

#### [debug]

Enable

-     Enable=false

  Arazketa gaitzeko, ezarri `<etc>/gdm/custom.conf` fitxategiko araztu/Gaitu gakoan "true" balioa eta berrabiarazi GDM. Arazketa-irteera sistemaren erregistro-fitxategira (`<var>/log/messages` edo `<var>/adm/messages`, zure sistema eragilearen arabera) bidaliko da.

#### Segurtasun-aukerak

#### [security]

DisallowTCP

-     DisallowTCP=true

  Egia bada, orduan beti erantsi `-nolisten tcp` komando-lerroari itsatsitako Xserver zerbitzariak abiaraztean, horrela TCP konexioa debekatzeko. Konfigurazio seguruagoa da urruneko konexioak erabiltzen ez badituzu.

#### XDCMP euskarria

#### [xdmcp]

DisplaysPerHost

-     DisplaysPerHost=1

  Erasotzaileek zain daudenen ilara bete ez dezaten, GDMk konexio bakarra onartuko du urruneko ordenagailu bakoitzeko. Pantaila bat baino gehiago duten ordenagailuei eman nahi badizkiezu bistaratze-zerbitzuak, balio hau handitu beharko duzu.

  Kontuan izan onartzen den itsatsitako PANTAILEN kopurua ez dagoela mugatuta. XDMCP bidezko urruneko konexioak soilik mugatzen dira konfigurazio-aukera honen bidez.

Enable

-     Enable=false

  Ezarpen honetan egia ezartzen bada, urruneko pantailak/X terminalak GDM bidez kudeatzea ahalbidetzeko euskarria gaitzen da XDMCPn.

  `gdm`-k UDPren 177 atakako eskariak entzuten ditu. Ikusi ataken aukerak informazio gehiagorako.

  If GDM is compiled to support it, access from remote displays can be controlled using the TCP Wrappers library. The service name is `gdm`

  You should add

      gdm:.my.domain

  to your `<etc>/hosts.allow`, depending on your TCP Wrappers configuration. See the hosts.allow man page for details.

  Kontuan izan XDMCP ez dela protokolo bereziki segurua eta ideia ona dela UDPren 177 ataka blokeatzea suebakian, hura erabiltzea beharrezkoa ez baduzu.

HonorIndirect

-     HonorIndirect=true

  Enables XDMCP INDIRECT choosing (i.e. remote execution of `gdmchooser`) for X-terminals which do not supply their own display browser.

MaxPending

-     MaxPending=4

  Zerbitzu-ukapeneko erasoak eragozteko, GDMk zain dauden konexioen ilarak tamaina finkoa du. MaxPending parametroak adierazitako pantaila kopurua soilik abiarazi daiteke aldi berean.

  Kontuan izan parametro honek ez duela mugatzen kudeatu daitekeen urruneko pantailen kopurua. Konexio bat aldi berean abiarazi dezakeen pantaila kopurua soilik mugatzen du.

MaxSessions

-     MaxSessions=16

  Aldi berean kudeatuko diren gehieneko urruneko pantaila-konexioak zehazten ditu, alegia, zure ostalaria erabil dezaketen urruneko pantailen kopurua.

MaxWait

-     MaxWait=30

  GDM aplikazioa pantaila bat kudeatzeko prest dagoenean, saio-identifikatzaile bakarra duen ACCEPT pakete bat bidaltzen dio, ondorengo XDMCP solasaldietan erabiltzeko.

  Ondoren, GDMk saio-identifikatzailea zain daudenen ilaran jarriko du, pantailak MANAGE eskari baten bidez erantzun dezan itxaroten.

  MaxWait segundotan erantzunik jasotzen ez bada, GDMk pantaila hil dela ezarriko du eta zain daudenen ilaratik ezabatuko du, arteka beste pantaila batzuentzat libre utziz.

MaxWaitIndirect

-     MaxWaitIndirect=30

  The MaxWaitIndirect parameter determines the maximum number of seconds between the time where a user chooses a host and the subsequent indirect query where the user is connected to the host. When the timeout is exceeded, the information about the chosen host is forgotten and the indirect slot freed up for other displays. The information may be forgotten earlier if there are more hosts trying to send indirect queries then `MaxPendingIndirect`.

Port

-     Port=177

  `gdm` aplikazioak XDMCP eskarietarako entzun beharko lukeen UDPko ataka-zenbakia. Ez aldatu hau zer egiten ari zaren ez badakizu.

Willing

-     Willing=<etc>/gdm/Xwilling

  When the machine sends a WILLING packet back after a QUERY it sends a string that gives the current status of this server. The default message is the system ID, but it is possible to create a script that displays customized message. If this script does not exist or this key is empty the default message is sent. If this script succeeds and produces some output, the first line of it's output is sent (and only the first line). It runs at most once every 3 seconds to prevent possible denial of service by flooding the machine with QUERY packets.

### Ongietorri sinplearen konfigurazioa

The GDM default greeter is called the simple Greeter and is configured via GConf. Default values are stored in GConf in the `gdm-simple-greeter.schemas` file. These defaults can be overridden if the "gdm" user has a writable $HOME directory to store GConf settings. These values can be edited using the `gconftool-2` or `gconf-editor` programs. The following configuration options are supported:

### Ongietorria konfiguratzeko gakoak

/apps/gdm/simple-greeter/banner_message_enable

-     faltsua (boolearra)

  Harrerako mezuaren testua bistaratuko den ala ez kontrolatzen du.

/apps/gdm/simple-greeter/banner_message_text

-     NULL (katea)

  Harrerako mezuaren testua ongietorri-leihoan erakutsiko den ala ez zehazten du.

/apps/gdm/simple-greeter/disable_restart_buttons

-     faltsua (boolearra)

  Berrabiarazteko botoiak saio-hasierako leihoan erakusten diren ala ez kontrolatzen du.

/apps/gdm/simple-greeter/disable_user_list

-     faltsua (boolearra)

  Egia bada, aurpegien arakatzailea ez da saioa hasteko leihoan erakutsiko.

/apps/gdm/simple-greeter/logo_icon_name

-     ordenagailua (katea)

  Ezarri hemen ongietorri-logorako erabili beharreko ikono-izena.

/apps/gdm/simple-greeter/recent-languages

-     [] (kate-zerrenda)

  Ezarri hemen saio-hasierako leihoan lehenespenez erakutsiko den hizkuntzen zerrenda. Balio lehenetsia "[]" da. Ezarpen lehenetsiarekin, sistemaren hizkuntza lehenetsia soilik erakutsiko da eta "Bestelakoak..." aukerak erabiltzaileak hautatu ditzakeen eta erabilgarri dauden hizkuntzen zerrenda osoa erakutsiko du.

  Erabiltzaileek ez dute ezarpen hau aldatu behar eskuz. Horren ordez, GDMk konfigurazio-gako honetan hautatutako hizkuntzen arrastoa jasotzen du eta hizkuntzen konbinazio-koadroan erakusten ditu, "Beste bat..." aukerarekin batera. Horrela, sarritan hautatutako hizkuntzak errazago hautatu daitezke.

/apps/gdm/simple-greeter/recent-layouts

-     [] (kate-zerrenda)

  Ezarri hemen saio-hasierako panelean lehenespenez erakutsiko den teklatu-diseinuen zerrenda. Balio lehenetsia "[]" da. Ezarpen lehenetsiarekin, sistemaren teklatu-diseinu lehenetsia soilik erakutsiko da eta "Bestelakoak..." aukerak erabiltzaileak hautatu ditzakeen eta erabilgarri dauden teklatu-diseinuen zerrenda osoa erakutsiko du.

  Erabiltzaileek ez dute ezarpen hau aldatu behar eskuz. Horren ordez, GDMk konfigurazio-gako honetan hautatutako teklatu-diseinuen arrastoa jasotzen du eta teklatu-diseinuen konbinazio-koadroan erakusten ditu, "Beste bat..." aukerarekin batera. Horrela, sarritan hautatutako teklatu-diseinuak errazago hautatu daitezke.

/apps/gdm/simple-greeter/wm_use_compiz

-     faltsua (boolearra)

  Leiho-kudeatzailetzat compiz erabiltzen den (metacity ordez) kontrolatzen du.

### Irisgarritasunaren konfigurazioa

Atal honek GDM-k irisgarritasuna konfiguratzeko dituen aukerak deskribatzen ditu.

#### GDM irisgarritasunaren elkarrizketa-koadroa eta GConf gakoak

GDMren ongietorri-panelak erabilerraztasun-ikono bat erakutsen du saio-hasierako pantailan. Ikono horretan klik eginez, GDMren erabilerraztasun-koadroa irekitzen da. Bertan kontrol-laukien zerrenda bat dago, erabiltzaileak erabilerraztasuneko tresnak gaitu edo desgaitu ahal ditzan.

The checkboxes that correspond to the on-screen keyboard, screen magnifier and screen reader assistive tools act on the three GConf keys that are described in the next section of this document. By enabling or disabling these checkboxes, the associated GConf key is set to "true" or "false". When the GConf key is set to true, the assistive tools linked to this GConf key are launched. When the GConf key is set to "false", any running assistive tool linked to this GConf key are terminated. These GConf keys are not automatically reset to a default state after the user has logged in. Consequently, the assistive tools that were running during the last GDM login session will automatically be launched at the next GDM login session.

The other checkboxes in the GDM Accessibility Dialog do not have corresponding GConf keys because no additional program is launched to provide the accessibility features that they offer. These other options correspond to accessibility features that are provided by the Xserver, which is always running during the GDM session.

#### Irisgarritasuneko GConf gakoak

GDM-k honako GConf gakoak eskaintzen ditu irisgarritasun-eginbideak kontrolatzeko:

#### GDM konfigurazio-gakoak

/desktop/gnome/interface/accessibility

-     faltsua (boolearra)

  Erabilerraztasun-azpiegitura GDMren erabiltzaile-interfaze grafikoarekin abiaraziko den ala ez kontrolatzen du. Hori beharrezkoa da erabilerraztasunerako teknologia-programa askok funtzionatu dezaten.

/desktop/gnome/applications/at/screen_magnifier_enabled

-     faltsua (boolearra)

  Ezarrita badago, GConf gako honi lotutako irisgarritasun-tresnak abiaraziko dira GDMren erabiltzaile-interfaze grafikoko programarekin batera. Lehenespenez, hau pantaila handitzeko aplikazio bat da.

/desktop/gnome/applications/at/screen_keyboard_enabled

-     faltsua (boolearra)

  EEzarrita badago, GConf gako honi lotutako irisgarritasun-tresnak abiaraziko dira GDMren erabiltzaile-interfaze grafikoko programarekin batera. Lehenespenez, hau pantailako teklatua erakusteko aplikazio bat da.

/desktop/gnome/applications/at/screen_reader_enabled

-     faltsua (boolearra)

  Ezarrita badago, GConf gako honi lotutako irisgarritasun-tresnak abiaraziko dira GDMren erabiltzaile-interfaze grafikoko programarekin batera. Lehenespenez, hau pantaila-irakurle bat da.

#### GConf gakoak irisgarritasun-tresnekin estekatzea

For the screen_magnifier_enabled, the screen_keyboard_enabled, and the screen_reader_enabled GConf keys, the assistive tool which gets launched depends on the desktop files located in the GDM autostart directory as described in the "Autostart Configuration" section of this manual. Any desktop file in the GDM autostart directory can be linked to these GConf key via specifying that GConf key in the AutostartCondition value in the desktop file. So the exact AutostartCondition line in the desktop file could be one of the following:

    AutostartCondition=GNOME /desktop/gnome/applications/at/screen_keyboard_enabled
    AutostartCondition=GNOME /desktop/gnome/applications/at/screen_magnifier_enabled
    AutostartCondition=GNOME /desktop/gnome/applications/at/screen_reader_enabled

When an accessibility key is true, then any program which is linked to that key in a GDM autostart desktop file will be launched (unless the Hidden key is set to true in that desktop file). A single GConf key can even start multiple assistive tools if there are multiple desktop files with this AutostartCondition in the GDM autostart directory.

#### Irisgarritasun-tresnaren konfigurazioa aldatzearen adibidea

For example, if GNOME is distributed with GOK as the default on-screen keyboard, then this could be replaced with a different program if desired. To replace GOK with the on-screen keyboard application "onboard" and additionally activate the assistive tool "mousetweaks" for dwelling support, then the following configuration is needed.

Create a desktop file for onboard and a second one for mousetweaks; for example, onboard.desktop and mousetweaks.desktop. These files must be placed in the GDM autostart directory and be in the format as explained in the "Autostart Configuration" section of this document.

Hurrengoa `onboard.desktop` fitxategiaren adibide bat da:

    [Desktop Entry]
    Encoding=UTF-8
    Name=Onboard Onscreen Keyboard
    Comment=Use an on-screen keyboard
    TryExec=onboard
    Exec=onboard --size 500x180 -x 20 -y 10
    Terminal=false
    Type=Application
    StartupNotify=true
    Categories=GNOME;GTK;Accessibility;
    AutostartCondition=GNOME /desktop/gnome/applications/at/screen_keyboard_enabled

Hurrengoa `mousetweaks.desktop` fitxategiaren adibide bat da:

    [Desktop Entry]
    Encoding=UTF-8
    Name=Software Mouse-Clicks
    Comment=Perform clicks by dwelling with the pointer
    TryExec=mousetweaks
    Exec=mousetweaks --enable-dwell -m window -c -x 20 -y 240
    Terminal=false
    Type=Application
    StartupNotify=true
    Categories=GNOME;GTK;Accessibility;
    AutostartCondition=GNOME /desktop/gnome/applications/at/screen_keyboard_enabled

Begiratu nola dagoen AutostartCondition deritzon lerro bat mahaiganeko bi fitxategiak pantailako teklaturako dagoen GConf gakoarekin lotzeko.

To disable GOK from starting, the desktop file for the GOK on-screen keyboard must be removed or deactivated. Otherwise onboard and GOK would simultaneously be started. This can be done by removing the gok.desktop file from the GDM autostart directory, or by adding the "Hidden=true" key setting to the gok.desktop file.

Aldaketa horiek egin ondoren, GOK ez da abiaraziko erabiltzaileak GDM saioan pantailako teklatua aktibatzen duenean; horren ordez, "onboard" eta "mousetweaks" abiaraziko dira.

### Saio orokorraren ezarpenak

The GDM Greeter uses some of the same framework that your desktop session will use. And so, it is influenced by a number of the same GConf settings. For each of these settings the Greeter will use the default value unless it is specifically overridden by a) GDM's installed mandatory policy b) system mandatory policy. GDM installs its own mandatory policy to lock down some settings for security.

### GNOME ezarpenen daemon-a

GDMk honako gnome-settings-daemon pluginak gaitzen ditu: a11y-keyboard, background, sound, xsettings.

Plugin horiek atzeko planoko irudia, letra-tipoak eta gaiak, soinuak eta abar kontrolatzen dituzte.

GConf bidez ere desgaitu daitezke pluginak. Adibidez, soinuaren plugina desgaitu nahi baduzu, erabili honako gakoa: `/apps/gdm/simple-greeter/settings-manager-plugins/sound/active`.

### GDM saioaren konfigurazioa

GDM sessions are specified using the FreeDesktop.org Desktop Entry Specification, which can be referenced at the following URL: https://www.freedesktop.org/wiki/Specifications/desktop-entry-spec.

By default, GDM will install desktop files in the `<share>/xsessions` directory. GDM will search the following directories in this order to find desktop files: `<etc>/X11/sessions/`, `<dmconfdir>/Sessions`, `<share>/gdm/BuiltInSessions`, and `<share>/xsessions`. By default the `<dmconfdir>` is set to `<etc>/dm/` unless GDM is configured to use a different directory via the "--with-dmconfdir" option.

A session can be disabled by editing the desktop file and adding a line as follows: `Hidden=true`.

GDM desktop files support a GDM-specific extension, a key named "X-GDM-BypassXsession". If the key is not specified in a desktop file, the value defaults to "false". If this key is specified to be "true" in a desktop file, then GDM will launch the program specified by the desktop file "Exec" key directly when starting the user session. It will not run the program via the `<etc>/gdm/Xsession` script, which is the normal behavior. Since bypassing the `<etc>/gdm/Xsession` script avoids setting up the user session with the normal system and user settings, sessions started this way can be useful for debugging problems in the system or user scripts that might be preventing a user from being able to start a session.

### GDM erabiltzaile-saioaren eta hizkuntzaren konfigurazioa

The user's default session and language choices are stored in the `~/.dmrc` file. When a user logs in for the first time, this file is created with the user's initial choices. The user can change these default values by simply changing to a different value when logging in. GDM will remember this change for subsequent logins.

The `~/.dmrc` file is in the standard `INI` format. It has one section called `[Desktop]` which has two keys: `Session` and `Language`.

The `Session` key specifies the basename of the session `.desktop` file that the user wishes to normally use without the `.desktop` extension. The `Language` key specifies the language that the user wishes to use by default. If either of these keys is missing, the system default is used. The file would normally look as follows:

    [Desktop]
    Session=gnome
    Language=cs_CZ.UTF-8

## GDM komandoak

### GDM root erabiltzailearen komandoak

GDM paketeak hurrengo komandoak eskaintzen ditu `sbindir` fitxategian, erro-erabiltzaileak exekutatuak izan daitezen:

#### `gdm` Komando-lerroko aukerak

`gdm` daemon nagusia da, saioa hasteko ingurune grafikoa konfiguratzen duena eta beharrezkoak diren laguntzaileak abiarazten dituena.

#### `gdm` Komando-lerroko aukerak

-?, --help

- Komando-lerroko aukeren azalpen laburra ematen du.

--fatal-warnings

- Edozein abisurekin GDM amaitzea eragiten du.

--timed-exit

- Irten 30 segundo ondoren. Erabilgarria arazketarako.

--version

- GDM daemon-aren bertsioa inprimatzen du.

#### `gdm-restart` Komando-lerroko aukerak

`gdm-restart` komandoak GDM gelditzen eta berrabiarazten du GDM daemon-ari HUP seinalea bidaliz. Komando horrek berehala amaituko ditu saio guztiak eta GDMrekin saioa hasi duten erabiltzaile guztien saioa amaituko du..

#### `gdm-safe-restart` Komando-lerroko aukerak

`gdm-safe-restart` komandoak GDM gelditzen eta berrabiarazten du GDM daemon-ari USR1 seinalea bidaliz. GDM berrabiarazi egingo da erabiltzaile guztiek saioa amaitu ondoren.

#### `gdm-stop` Komando-lerroko aukerak

`gdm-stop` komandoak GDM gelditzen du GDM daemon-ari TERM seinalea bidaliz.

## Arazoen ebazpena

Atal honetan GDM martxan jartzeko iradokizunak ematen dira. Oro har, GDMrekin arazoren bat baduzu, akatsen jakinarazpen bat bidali dezakezu gdm-list posta-zerrendara mezu bat bidaliz. Hori nola egin jakiteko, begiratu dokumentuaren sarrerako atala.

If GDM is failing to work properly, it is always a good idea to include debug information. To enable debugging, set the debug/Enable key to "true" in the `<etc>/gdm/custom.conf` file and restart GDM. Then use GDM to the point where it fails, and debug output will be sent to the system log file (`<var>/log/messages` or `<var>/adm/messages` depending on your Operating System). If you share this output with the GDM community via a bug report or email, please only include the GDM related debug information and not the entire file since it can be large. If you do not see any GDM syslog output, you may need to configure syslog (refer to the syslog man page).

### GDM ez da hasten

GDMk gaizki funtzionatzea eragin dezaketen hainbat arazo daude, baina atal honetan arruntenak diren arazo gutxi batzuk soilik azaltzen dira, eta horiek konpontzeko bidea zein den aipatzen da. Arazo batzuen ondorioz, GDMk errore-mezu bat ematen du edo elkarrizketa-koadro bat irekitzen du abiarazten saiatzen denean, baina zaila izan daiteke arazoen jatorria aurkitzea GDMk ezer esan gabe huts egiten duenean.

First make sure that the Xserver is configured properly. The GDM configuration file contains a command in the [server-Standard] section that is used for starting the Xserver. Verify that this command works on your system. Running this command from the console should start the Xserver. If it fails, then the problem is likely with your Xserver configuration. Refer to your Xserver error log for an idea of what the problem may be. The problem may also be that your Xserver requires different command-line options. If so, then modify the Xserver command in the GDM configuration file so that it is correct for your system.

Ziurtatu, baita ere, `/tmp` direktorioak jabetza eta baimen egokiak ditula eta makinaren fitxategi-sistema ez dagoela beteta. Arazo horiek GDMren hutsegitea eragin dezakete.

## Lizentzia

Programa hau software librea da; birbana eta/edo alda dezakezu Free Software Foundation fundazioak argitaratutako Lizentzia Publiko Orokorraren 2. bertsioan, edo (nahiago baduzu) bertsio berriago batean, jasotako baldintzak betez gero.

Programa hau erabilgarria izango delakoan banatzen da, baina INOLAKO BERMERIK GABE; era berean, ez da bermatzen beraren EGOKITASUNA MERKATURATZEKO edo HELBURU PARTIKULARRETARAKO ERABILTZEKO. Argibide gehiago nahi izanez gero, ikus GNU Lizentzia Publiko Orokorra.

GNU Lizentzia Publiko Orokorraren kopia bat GNOMEren erabiltzailearen gidaren eranskinean daukazu. GNU Dokumentazio Librearen Lizentziaren kopia bat lor dezakezu Free Software Foundation fundazioaren bidez, haien wegunean edo hona idatzita:

          Free Software Foundation, Inc.
          51 Franklin Street, Fifth Floor
          Boston, MA 02110-1301
          USA