<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [
<!ENTITY legal SYSTEM "legal.xml">
<!ENTITY version "2.26.0">
<!ENTITY date "02/10/2009">
<!ENTITY mdash "&#8212;">
<!ENTITY percnt "&#x0025;">
]>
<article id="index" lang="gl">
  <articleinfo>
    <title>Manual de referencia do Xestor de entrada de GNOME</title>

    <revhistory>
      <revision><revnumber>0.0</revnumber> <date>2008-09</date></revision>
    </revhistory>

    <abstract role="description">
      <para>GDM é o Xestor de entrada de GNOME, un programa gráfico de inicio de sesión.</para>
    </abstract>

    <authorgroup>
      <author><firstname>Martin</firstname><othername>K.</othername> <surname>Petersen</surname> <affiliation> <address><email>mkp@mkp.net</email></address> </affiliation></author>
      <author><firstname>George</firstname><surname>Lebl</surname> <affiliation> <address><email>jirka@5z.com</email></address> </affiliation></author>
      <author><firstname>Jon</firstname><surname>McCann</surname> <affiliation> <address><email>mccann@jhu.edu</email></address> </affiliation></author>
      <author><firstname>Ray</firstname><surname>Strode</surname> <affiliation> <address><email>rstrode@redhat.com</email></address> </affiliation></author>
      <author role="maintainer"><firstname>Brian</firstname><surname>Cameron</surname> <affiliation> <address><email>Brian.Cameron@Oracle.COM</email></address> </affiliation></author>
    </authorgroup>
    <copyright><year>1998</year> <year>1999</year> <holder>Martin K. Petersen</holder></copyright>
    <copyright><year>2001</year> <year>2003</year> <year>2004</year> <holder>George Lebl</holder></copyright>
    <copyright><year>2003</year> <year>2007</year> <year>2008</year> <holder>Red Hat, Inc.</holder></copyright>
    <copyright><year>2003</year> <year>2011</year> <holder>Oracle e/ou os seus afiliados. Todos os dereitos reservados.</holder></copyright>

      <legalnotice id="legalnotice">
	<para>Pode copiar, distribuír e modificar este documento baixo os termos da Licenza de Documentación Libre GNU (GFDL) na súa versión 1.1 ou posterior, publicada pola Free Software Foundation, sen seccións invariantes e sen textos de portada ou de contraportada. Pode atopar unha copia da GFDL en <ulink type="help" url="ghelp:fdl">link</ulink> ou no ficheiro COPYING-DOCS distribuído xunto con este manual.</para>
         <para>Este manual forma parte dunha colección de documentos de GNOME distribuidos segundo a GFDL. Se desexa distribuír este manual de forma independente da colección, pode facelo agregando unha copia da licenza ao documento, segundo se descibe na sección 6 da mesma.</para>

	<para>Moitos dos nomes empregados polas empresas para distinguir os seus produtos e servizos considéranse marcas comerciais. Cando estes nomes aparezan na documentación de GNOME, e sempre que se teña informado aos membros do Proxecto de documentación de GNOME de ditas marcas comerciais, os nomes aparecerán en maiúsculas ou coas iniciais en maiúsculas.</para>

	<para>DOCUMENT AND MODIFIED VERSIONS OF THE DOCUMENT ARE PROVIDED UNDER THE TERMS OF THE GNU FREE DOCUMENTATION LICENSE WITH THE FURTHER UNDERSTANDING THAT: <orderedlist>
		<listitem>
		  <para>DOCUMENT IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES THAT THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS FREE OF DEFECTS MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY, ACCURACY, AND PERFORMANCE OF THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS WITH YOU. SHOULD ANY DOCUMENT OR MODIFIED VERSION PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT THE INITIAL WRITER, AUTHOR OR ANY CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. NO USE OF ANY DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER; AND</para>
		</listitem>
		<listitem>
		  <para>EN NINGUNHA CIRCUNSTANCIA NIN SEGUNDO NINGÚN ARGUMENTO LEGAL, SEXA POR MOTIVOS CULPOSOS (INCLUÍDA A NEGLIXENCIA), CONTRACTUAIS OU DE OUTRO TIPO, NIN O AUTOR, NIN O REDACTOR INICIAL, NIN CALQUERA COLABORADOR, NIN CALQUERA DISTRIBUIDOR DO DOCUMENTO OU VERSIÓN MODIFICADA DO MESMO, NIN CALQUERA FORNECEDOR DE CALQUERA DE DITAS PARATES, SERÁN RESPONSÁBEIS, ANTE NINGÚN TERCEIRO, DE NINGÚN DANO OU PERXUIZO DIRECTO, INDIRECTO, ESPECIAL, INCIDENTAL OU CONSIGUIENTE DE NINGÚN TIPO, INCLUÍDOS, SEN LIMITACIÓN, OS DANOS POR PERDA DE FONDO DE COMERCIO, INTERRUPCIÓN DO TRABALLO, FALLO OU MAL FUNCIONAMENTO INFORMÁTICO, NIN CALQUERA OUTRO DANO OU PERDA DERIVADA DO USO DO DOCUMENTO E AS VERSIÓNS MODIFICADAS DO MESMO, OU RELACIONADO CON ILO, INCLUSO SE SE COMUNICOU A AQUELA PARTE A POSIBILIDADE DE TALES DANOS.	</para>
		</listitem>
	  </orderedlist></para>
  </legalnotice>



    <releaseinfo>Este manual describe a versión 2.26.0 do Xestor de entrada de GNOME. Actualizouse por última vez o 2 de febreiro de 2009.</releaseinfo>  
  
    <othercredit class="translator">
      <personname>
        <firstname>Fran Dieguez</firstname>
      </personname>
      <email>frandieguez@gnome.org</email>
    </othercredit>
    <copyright>
      
        <year>2012-2013.</year>
      
      <holder>Fran Dieguez</holder>
    </copyright>
  </articleinfo>

  <!-- ============= Preface ================================== -->

  <sect1 id="preface">
    <title>Termos e convencións usados neste manual</title>

    <para>Este manual describe a versión 2.26.0 do Xestor de entrada de GNOME. Actualizouse por última vez o 2 de febreiro de 2009.</para>  

    <para>Selector: Un programa que se usa para seleccionar un equipo remoto para xestionar unha pantalla remotamente na pantalla local (<command>gdm-host-chooser</command>).</para>

    <para>FreeDesktop: A organización que fornece estándares para o escritorio, tales como a Especificación de Entrada do Escritorio que usa GDM <ulink type="http" url="http://www.freedesktop.org/">http://www.freedesktop.org</ulink>.</para>
    <para>GDM: O xestor de entrada de GNOME. Úsase para describir o paquete de software como un todo.</para>

    <para>Interface de entrada con temas - A xanela de entrada gráfica (fornecido por <command>gnome-shell</command>).</para>

    <para>PAM: Mecanismo de engadidos de autenticación (Pluggable Autentication Mechanism)</para>

    <para>XDMCP: Protocolo de xestión de pantallas X (X Display Manager Protocol)</para>

    <para>Servidor X: Unha implementación do X Windows System. Por exemplo, o servidor X de Xorg fornecido pola Fundación X.org <ulink type="http" url="http://www.x.org/">http://www.x.org</ulink>.</para>

    <para>Rutas que comezan cunha palabra entre parénteses son relativas ao prefixo de instalación, p.ex. <filename>&lt;share&gt;/pixmaps/</filename> refírese a <filename>/usr/share/pixmaps</filename> se GDM configurouse con <command>--prefix=/usr</command>.</para>
  </sect1>

  <!-- ============= Overview ================================= -->

  <sect1 id="overview">
    <title>Vista xeral</title>

    <sect2 id="introduction">
      <title>Introdución</title>

      <para>O Xestor de entrada de GNOME (GDM) é un xestor de entrada que implementa todas as características significativas requiridas para xestionar pantallas remotas e locais. GDM escribiuse desde cero e non contén nada de código de XDM ou do X Consortium.</para>

      <para>Note que o GDM é altamaente configurábel e moitos axustes de configuración poden afectar á seguranza. Os temas sobre os que debe prestar atención están realzados neste documento.</para> 

      <para>Note que algúns sistemas operativos configuran GDM para comportarse de forma diferente aos valores predetermiandos, como se describe neste documento. Se GDM non parece comportarse como se documenta, entón comprobe se algunha configuración relacionada difire da aquí describa.</para>

      <para lang="en">
        For further information about GDM, refer to the project website at
        <ulink type="http" url="http://wiki.gnome.org/Projects/GDM/">
        http://wiki.gnome.org/Projects/GDM</ulink>.
      </para>

      <para>Para discusións ou consultas sobre GDM, diríxase á rolda de correo <address><email>gdm-list@gnome.org</email></address>. Esta lista está arquivada, e é unha boa fonte para buscar respostas a preguntas comúns. Esta lista está arquivada en <ulink type="http" url="http://mail.gnome.org/archives/gdm-list/">http://mail.gnome.org/archives/gdm-list/</ulink> e ten busca integrada para atopar mensaxes con palabras chave.</para>

      <para>Envía calquera informe de erro ou peticións de mellora na categoría «gdm» en <ulink type="http" url="http://bugzilla.gnome.org/">http://bugzilla.gnome.org</ulink>.</para>
    </sect2>

    <sect2 id="stability">
      <title>Estabilidade de interfaces</title>

      <para>GDM 2.20 e máis actuais admiten as interfaces estábeis de configuración. Porén, o código base foi completamente rescrito en GDM 2.22, e pode non ser completamente compatíbel cara atrás con publicacións antigas. Isto é en parte porque as cousas funcionan de forma diferente, polo que algunhas opcións agora xa non teñen sentido, en parte porque algunhas opcións nunca tiveron sentido e en parte porque algunha funcionalidade non foi reimplementada.</para>

      <para>As interfaces que continúan sendo compatíbeis nun sentido estábel inclúen os scripts de Init, PreSession, PostSession, PostLogin e Xsession. Algunhas opcións de configuración do «daemon» do ficheiro <filename>&lt;etc&gt;/gdm/custom.conf</filename> continúan sendo compatíbeis. Ademais, <filename>~/.dmrc</filename>, e as localizacións das imaxes continúan sendo compatíbeis.</para>

      <para>GDM 2.20e máis actual admitían a característica de xestionar múltiples pantallas con tarxetas gráficas separadas, como son usados en ambientes de servidor de terminais, inicio de sesión nunha xanela mediante programas como Xnest ou Xephyr, o programa gdmsetup, os temas de benvida baseados en XL e a característica de executar o selector de XDMCP desde o inicio de sesión. Estas características non foron restauradas durante a rescritura de 2.22.</para>

    </sect2>

    <sect2 id="functionaldesc">
      <title>Descrición funcional</title>

<!--
<para>
        TODO - Would be good to discuss D-Bus, perhaps the new GObject model,
               and to explain the reasons why the rewrite made GDM better.
               From a high-level overview perspective, rather than the
               technical aspects.
</para>
-->

      <para>GDM é responsábel de xestionar pantallas no seu sistema. Isto inclúe a autenticación de usuarios, iniciar e rematar a sesión de usuario. GDM é configurábel e pode atopar unha descrición das formas de como pode facelo na sección «Configurando GDM» deste documento. GDM tamén é accesíbel para os usuarois con discapacidades.</para>

      <para>GDM fornece a característica de xestionar a pantalla da console principal e as pantallas iniciadas en VT. Está integrado con outros programas, como o miniaplicativo de Intercambio de usuarios rápido (FUSA) e o gnome-screensaver para xestionar as pantallas múltiples nunha consola mediante a interface de Terminal Virtual Xserver (VT). Tamén pode xestionar pantallas XDMCP.</para>

      <para>Con respecto do tipo de pantalla, GDM fará o seguinte cando xestione a pantalla. Comezará o proceso Xserver, logo executará o script <filename>Init</filename> como un usuario root, e logo iniciará o programa de benvida na pantalla.</para>

      <para>O programa de benvida execútase co usuario/grupo sen privilexios. Este usuario e grupo descríbense na sección "Seguridade" deste documento. As funcións principais do programa de bencida é de fornecer un mecanismo para seleccionar unha conta onde iniciar sesión e conducir o diálogo entre o usuario e o sistema ao autenticarse con dita conta. O proceso de autenticación está conducido polos Modulos de Autenticación Conetábeis (PAM). Os modulos PAM determinan que preguntas (se as hai) se mostran ao usuario ao autenticarse. Nun sistema normal, o programa de benvida solicitará un nome de usuario e un contrasinal para autenticarse. Porén nalgúns sistemas configurados para empregar mecanismos suplementarios como a pegada dixital ou lectores de tarxetas intelixentes. GDM pode configurarse para admitir estas alternativas en paralelo coas extensións de inicio de sesión da pantalla de benvida e a opción <command>--enable-split-authentication</command> <filename>./configure</filename>, ou unha á vez mediante a configuración PAM do sistema.</para>

      <para>A extensión de tarxetas intelixentes pode activarse ou desactivarse mediante a chave de gsettings <filename>org.gnome.display-manager.extensions.smartcard.active</filename>.</para>

      <para>Seguramente, a extensión de pegada dixital pode activarse ou desactivarse mediante a chave de gsettings <filename>org.gnome.display-manager.extensions.fingerprint.active</filename>.</para>

      <para>GDM e PAM pode configurarse para non requirir ningunha entrada, que causará que GDM inicie sesión automaticamente e logo inicie a sesión, o cal pode ser útil para algúns ambientes, como en sistemas de usuario único e quioscos.</para>

      <para>Ademais da autenticación, o programa de benvida permítelle ao usuario seleccionar que sesión iniciar e en que idioma. As sesións están definidas por ficheiros que rematan co sufixo .desktop e pode atopar máis información sobre estes ficheiros na sección «Configuración de sesión de usuario e idioma de GDM». Por omisión, GDM está configurado para mostrar un listado de caras para que o usuario poida seleccionar a súa conta de usuario ao premer nunha imaxe no lugar de ter que escribir o seu contrasinal. GDM fai un seguemento da sesión por omisión do usuario e do idioma no <filename>~/.dmrc</filename> do usuario e usará estas configuración predefinidas se o usaurio non selecciona unha sección ou idioma no GUI de inicio de sesión.</para>

      <para>Despois de autenticar a un usuario, o «daemon» executa o script <filename>PostLogin</filename> como usuario root, e logo executa o script <filename>PreSession</filename> como usuario root. Despois de executar estes scripts a sesión do usuario arríncase. Cando o usuario sae da súa sesión, o script <filename>PostSession</filename> execútarase como usuario root. Estes scripts fornécense como hooks para as distribucións e aos usuario finais para personalizar como se xestionan as sesións. Por exemplo, usando estes hooks pode configurar que a máquina cree o cartafol de usuario $HOME ao voo, e o elimine ao iniciar sesión. A diferenza entre os scripts <filename>PostLogin</filename> e<filename>PreSession</filename> son que <filename>PostLogin</filename> execútase antes da chamada a pam_open_session polo que é o lugar correcto para facer calquera cousaa que se debería executar antes de que a sesión do usuario se inicialice.</para>
    </sect2>

    <sect2 id="greeterpanel">
      <title>O panel da interface de entrada con temas</title>
      <para>A pantalla de benvida de GDM mostra un panel situado na parte inferior da pantalla que fornece funcionalidade adicional. Cando un usuario está seleccionado o panel permítelle ao usuario seleccionar a sesión, idioma e distribución de teclado que quere usar ao iniciar sesión. O selector da distribución do teclado tamén cambia a distribución do teclado ao escribir o seu contrasinal.O panel tamén contén un área para que os servizos de inicio de sesión poidan deixar iconas de estado. Como exemplo dalgunhas iconas atopará unha icona do estado da batería e unha icona para activar características de accesibilidade. O programa de benvida tamén fornece botóns que lle permiten ao usuario apagar ou reiniciar o seu sistema. É posíbel configurar GDM para non fornecer os botóns de apagar ou reinicio, se o desexa. GDM tamén pode configurarse mediante PolicyKit (ou mediante RBAC en Oracle Solaris) para requirir que o usuario teña unha autorización axeitada antes de aceptar unha solicitude de apagado ou reinicio.</para>

      <para>Teña en conta que as características de disposición do teclado só están dispoñíbeis en sistemas que son compatíbeis con libxklavier.</para>
    </sect2>

    <sect2 id="accessibility">
      <title>Accesibilidade</title>

        <para>GDM admite «Inicio de sesión accesíbel», o cal lle permite iniciar sesión nunha sesión de escritorio incluso cando non pode usar de forma doada a pantalla, o rato ou o teclado na forma normal. A Tecnoloxía de Accesibilidade (AT) ten características como teclado en pantalla, lector de pantalla, magnificador de pantalla e accesibilidade de teclado AccessX de Xserver. Vaia á sección «Configuración de accesibilidade»do documento para obter máis información sobre como se poden configurar as distintas características de accesibilidade. </para>

        <para>Nalgúns sistemas operativos, é necesario asegurarse que o usuario de GDM é un membro do grupo «audio» para os programas de AT que requiren saída de son (como texto-a-fala) para que sexan funcionais.</para>
    </sect2>

    <sect2 id="facebrowser">
      <title>O visor de rostros de GDM</title>

      <para>O explorador de caras é a interface que lle permite os usuarios seleccionar o seu nomem de usuario seleccionando unha imaxe. Esta característica pode activarse ou desactivarse mediante a chave de lista de Gsettings org.gnome.login-screen disable-user-enabled, a cal está activada por omisión. Ao activala, mostrará todos os usuarios locais que están dispoñíbeis para iniciar sesión no sistema (todas as contas de usuario definidas en /etc/password que teñan unha shell válida e un UID suficientemente alto) e os usuarios remotos que iniciaran sesión recentemente. O explorador de caras en GDM 2.20 e superior tentarán mostrar todos os usuarios remotos o que pode causar problemas de rendemento para despregues empresariais grandes.</para>

      <para>O Explorador de caras está configurado para mostrar os usuarios que inician sesión máis frecuentemente na parte superior da lista. Isto axúdalle a asegurarse que os usuarios que inician sesión con máis frecuencia poida atoparse a súa imaxe de inicio de sesión máis rápido.</para>

      <para>O explorador de caras admite "busca adiantada" que move dinámicamente a selección de cara mentres o usuario escribe o correspondente nome de usuario na lista. Isto significa que un usuario con un nome de usuario longo só ten que escribir os primeiros caracteres do seu nome antes de que seleccione o elemento correcto na lista.</para>

      <para>As iconas usadas por GDM están instaladas de forma global polo administrador do sistema ou poden estar nos cartafoles persoais dos usuarios. Se está instalada de forma global debería estar no cartafol <filename>&lt;share&gt;/pixmaps/faces/</filename> e o nome de ficheiro debería ser o nome de usuario. Os ficheiros de imaxes de avatar no cartafol «face» global debe poder lerse polo usuario GDM.  </para>

<!--
<para>
        TODO - In the old GDM the ~/gnome2/gdm file is used, but the new code
               seems to use ~/.gnome/gdm.  Error?
</para>
-->
      <para>Non hai unha icona global para o usuario, GDM bucará no cartafol $HOME do usuario pola imaxe. GDM primeiro mirará o ficheiro de avatar do usuario en <filename>~/.face</filename>. Se non o atopa, tentará <filename>~/.face.icon</filename>. Se aínda non o atopou, usará o valor definido por "face/picture=" no ficheiro <filename>~/.gnome2/gdm</filename>.</para>

      <para>Se o usuario non ten unha imaxe de avatar definida, GDM usará a icona «stock_person» definida no tema GTK+ actual. Se non hai unha imaxe definida, usarase a imaxe de avatar xenérica. </para>

      <para>Teña en conta que cargar e escalar iconas de avatar localizadas en cartafoles persoais remotos pode ser unha tarefa que leve tempo. Xa que no é práctico cargar imaxes mediante NIS ou NFS, GDM non tentará cargar imaxes desde cartafoles persoais remotos.</para>

      <para>Cando o explorador está activado, os nomes de usuario válidos no computador mostraranse para calquera que poida ver. Se XDMCP está activado, os nomes de usuario móstranse tamén para os usuario remotos. Isto, por suposto, limita a seguridade xa que un usuario malicioso non precisa adiviñar os nomes de usuarios válidos. Nalgúns ambientes restritivos o explorador de avatares podería non ser o axeitado.</para>

    </sect2>

    <sect2 id="xdmcp">
      <title>XDMCP</title>

<!--
<para>
        TODO - What XDMCP features actually work?   I know that the
               chooser is missing.
</para>
-->

      <para>O «daemon» GDM pode configurarse para escoitar e xestionar peticións X Display Manage Protocol (XDMCP) desde pantallas remotas. Por defecto a compatibilidade con XDMCP está descativada, porén pode activala se o desexa. Se GDM se constrúe con compatibilidade de wrapper TCP, o daemon só lle dará acceso a equipos específicos na sección do servizo GDM do ficheiro de configuración de TCP Wrappers.</para>

      <para>GDM inclúe varias medidas que o fan máis resistente a ataques de denegación de servizo en XDMCP. Moitos dos parámetros do protocolo, tempos de espera de negociación, etc. poden axustarse.. A configuración predefinida debería funcionar razoabelmente ben na maioría dos sistemas.</para>

      <para>GDM escoita por omisión ás peticións XDMCP no porto UDP normal usado por XDMCP, o porto 177, e responderá ás peticións QUERY e BROADCAST_QUERY enviando un paquete WILLING ao remitente.</para>

      <para>GDM tamen pode configurarse para ceder consultas INDIRECT e mostrar un selector de equipo dunha pantalla remota. GDM recordará a elección do usuario e derivará as subsecuentes consultas ao xestor de elección. GDM tamén permite que unha extensión do protocolo faga a redirección en canto a conexión do usuario teña éxito. Esta extensión só se admite se ámbolos dous daemons son GDM. É transparente e é ignorada por XDM ou outros daemons que implementen XDMCP.</para>

      <para>Se semella que XDMCP non está funcionando, asegúrese que todos os computadores están especificados no ficheiro <filename>/etc/hosts</filename>.</para>

      <para>Consulte a sección «Seguridade» para obter máis información sobre a seguridade ao usar XDMCP.</para>
    </sect2>

    <sect2 id="logging">
      <title>Rexistro de actividade</title>

      <para>GDM usa syslog para rexistrar erros e o seu estado. Tamén pode rexistrar información de depuración, a cal pode ser útil para facer un seguemento dos problemas se GDM non está funcionando correctamente. A saída de depuración pode activarse configurando a chave de configuración debug/Enable a «true» no ficheiro <filename>&lt;etc&gt;/gdm/custom.conf</filename>.</para>

      <para>A saída para varios Xservers almacénase no cartafol de rexistro de GDM, o cal normalmente está en <filename>&lt;var&gt;/log/gdm/</filename>. Calquera mensaxe de Xserver gardarase no ficheiro asociado co valor da pantalla, <filename>&lt;display&gt;.log</filename>.</para>

      <para>A saída da sesión é derivada mediante o daemon de GDM ao ficheiro <filename>~/<replaceable>$XDG_CACHE_HOME</replaceable>/gdm/session.log</filename> que normalmente expánde a <filename>~/.cache/gdm/session.log</filename>. O ficheiro sobrescríbese en cada inicio de sesión, polo que ao saír da sesión e volver a entrar co mesmo usuario mediante GDM causará  que se perda calquera mensaxe da sesión anterior.</para>

      <para>Teña en conta que se GDM non pode crear este ficheiro por calquera razón, crearase  un ficheiro de respaldo co nome <filename>~/<replaceable>$XDG_CACHE_HOME</replaceable>/gdm/session.log.XXXXXXXX</filename> onde <filename>XXXXXXXX</filename> son caracteres aleatorios.</para>
    </sect2>

    <sect2 id="fusa">
      <title>Cambio rápido de usuarios</title>

      <para lang="en">
        GDM allows multiple users to be logged in at the same time.  After one
        user is logged in, additional users can log in via the User Switcher
        on the GNOME Panel, or from the "Switch User" button in Lock Screen dialog
        of GNOME Screensaver.  The active session can be changed back and forth using
        the same mechanism.  Note that some distributions may not add the User Switcher
        to the default panel configuration.  It can be added using the panel context
        menu.
      </para>
      <para>Teña en conta que esta característica só está dispoñíbel en sistemas que admiten Terminais Virtuais. Esta característica non funcionará se as Terminais virtuais non funcionan.</para>
    </sect2>
  </sect1>

  <!-- ============= Security ================================= -->

  <sect1 id="security">
    <title>Seguranza</title>

    <sect2 id="gdmuser">
      <title>O usuario e grupo de GDM</title>

      <para lang="en">
        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.
      </para>

      <para lang="en">
        The only special privilege the "gdm" user requires is the
        ability to read and write Xauth files to the
        <filename>&lt;var&gt;/run/gdm</filename> directory.  The
        <filename>&lt;var&gt;/run/gdm</filename> directory should have
        root:gdm ownership and 1777 permissions.
      </para>

      <para lang="en">
        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
        <filename>nobody</filename>.  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.
      </para>

      <para lang="en">
        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.
      </para>
    </sect2>

    <sect2 id="PAM">
      <title>PAM</title>

      <para lang="en">
        GDM uses PAM for login authentication.  PAM stands for Pluggable
        Authentication Module, and is used by most programs that request
        authentication on your computer.  It allows the administrator to
        configure specific authentication behavior for different login programs
        (such as ssh, login GUI, screensaver, etc.)
      </para>

      <para lang="en">
        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.
      </para>
        
      <para>A configuración PAM ten interfaces diferentes, pero similares, para os distintos sistemas operativos, polo que comprobe a páxina man <ulink type="help" url="man:pam.d">pam.d</ulink> ou <ulink type="help" url="man:pam.conf">pam.conf</ulink>. Asegúrese que lee a documentación PAM e ten en conta as implicacións de seguridade que calquera cambio que queira facer na súa configuración.</para>

      <para>Teña en conta que, por omisión, GDM usa o nome de servizo PAM «gdm» para o inicio de sesión normal e o nome de servizo PAM «gdm-autologin» para os inicios de sesión automáticos. Se non hai entrada entón GDM usará o comportamento PAM por omisión. Na maioría dos sistemas isto funcionará ben, porén, no inicio de sesión automático pode que non funcione se o servizo gdm-autologin non está definido.</para>

      <para>O script <filename>PostLogin</filename> execútase antes de que se chame a pam_open_session, e o script <filename>PreSession</filename> chámase despois. Isto permítelle ao administrador do sistema engadir calquera script no proceso de inicio de sesión antes ou despois de que PAM inicialice a sesión.</para>

      <para lang="en">
        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.  How to do
        this is frequently discussed on the 
        <address><email>gdm-list@gnome.org</email></address> mail list,
        so you can refer to the list archives for more information.
      </para>

      <para lang="en">
        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.
      </para>

      <para lang="en">
        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:
      </para>

<screen>
       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
</screen>

      <para>A configuración de arriba causará que a entrada lastlog non se xere. Se desexa unha entrada lastlog entón use o seguinte para a sesión:</para>

<screen>
       gdm-autologin session required pam_unix_session.so.1
</screen>

      <para lang="en">
        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:
      </para>

<screen>
      gdm auth  sufficient  pam_succeed_if.so  user ingroup nopasswdlogin
</screen>

    </sect2>

    <sect2 id="utmpwtmp">
      <title lang="en">utmp and wtmp</title>

      <para lang="en">
        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
        <command>finger</command>, <command>last</command>,
        <command>login</command>, and <command>who</command>.  The wtmp
        database contains the history of user access and accounting 
        information for the utmp database.  Refer to the 
        <ulink type="help" url="man:utmp">utmp</ulink> and
        <ulink type="help" url="man:wtmp">wtmp</ulink>
        man pages on your system for more information.
      </para>
    </sect2>

    <sect2 id="xauth">
      <title>Esquema de autenticación do servidor X</title>

      <para lang="en">
        Xserver authorization files are stored in a newly created subdirectory
        of <filename>&lt;var&gt;/run/gdm</filename> 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.
      </para>

      <para lang="en">
        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.
      </para>

    </sect2>

    <sect2 id="xdmcpsecurity">
      <title>Seguranza XDMCP</title>

      <para lang="en">
        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.
      </para>

      <para lang="en">
        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.
      </para>

    </sect2>

    <sect2 id="xdmcpaccess">
      <title>Control de acceso XDMCP</title>

      <para>O control de acceso de XDMCP está construído empregando envoltorios de TCP. É posíbel compilar GDM sen a compatibilidade de envoltorios de TCP, polo que esta característica podería non admitirse nalgúns sistemas operativos.</para>

      <para>Debería usar un nome de daemon <command>gdm</command> nos ficheiros <filename>&lt;etc&gt;/hosts.allow</filename> e <filename>&lt;etc&gt;/hosts.deny</filename>. Por exemplo para denegarlle o inicio de sesión desde <filename>.dominio.maligno</filename>, entón engada</para>
<screen>
gdm: .dominio.maligno
</screen>
      <para>a <filename>&lt;etc&gt;/hosts.deny</filename>. Tamén precisa engadir</para>
<screen>
gdm: .o.seu.dominio
</screen>
      <para>ao seu <filename>&lt;etc&gt;/hosts.allow</filename> se normalmente desautoriza todos os servizos desde todos os equipos. Vexa unha páxina d eman <ulink type="help" url="man:hosts.allow">hosts.allow(5)</ulink> para obter máis detalles.</para>
    </sect2>

    <sect2 id="firewall">
      <title>Seguranza con devasa</title>

      <para lang="en">
        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.
      </para>

      <para lang="en">
        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.
      </para>

      <para>X non é un protocolo moi seguro ao usalo por internet, e XDMCP é aínda menos seguro.</para>
    </sect2>

    <sect2 id="policykit">
      <title>PolicyKit</title>

<!--
<para>
        TODO - Should we say more?
</para>
-->

      <para>GDM pode configurarse para usar PolicyKit para permitirlle a un administrador de sistemas o control de se a pantalla de benvida debería fornecer os botóns de apagado e reinicio.</para>

      <para>Estes botóns están controlados polas accións <filename>org.freedesktop.consolekit.system.stop-multiple-users</filename> e <filename>org.freedesktop.consolekit.system.restart-multiple-users</filename> respectivamente. A normativa para estas acccións pode configurarse usando a ferramenta polkit-gnome-authorization ou o programa de liña de ordes polkit-auth.</para>
 
    </sect2>

    <sect2 id="rbac">
      <title>RBAC (Control de acceso baseado en rol)</title>

      <para>GDM pode configurarse para usar RBAC no lugar de PolicyKit. Neste caso a configuración de RBAC úsase para controlar se a pantalla de inicio de sesión debería fornecer os botóns de apagado e reinicio na pantalla de benvida.</para>

      <para>Por exemplo, en Oracle Soraris, úsase a autorización «solaris.system.shutdown» para controlar isto. Simplemente modifique o ficheiro <filename>/etc/user_attr</filename> para que o usuario «gdm» teña esta autorización.</para>
    </sect2>

  </sect1>

  <!-- ============= ConsoleKit ================================ -->

  <sect1 id="consolekit">
    <title>Compatibilidade para ConsoleKit</title>

<!--
<para>
    TODO - Should we update these docs?  Probably should mention any 
           configuration that users may want to do for using it with GDM?
           If so, perhaps this section should be moved to a subsection of
           the "Configure" section?
</para>
-->

    <para>GDM inclúe compatibilidade para publicar información de inicio de sesión do usuario co marco de traballo de contas de sesión e usuario coñecido como ConsoleKit. ConsoleKit pode facer un seguemento de todos os usuarios coa sesión aberta actualmente. Neste respecto, pode usarse como un substituto dos ficheiros utmp ou utmpx que están dispoñíbeis na maioría dos sistemas operativos Unix.</para>

    <para lang="en">
      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.
    </para>

    <para>No caso de que un usuario con unha sesión existente se autenticara en GDM e solicite retomar unha sesión existente, GDM chama ao método con privilexios de ConsoleKit para desbloquear a sesión. Os detalles exactos do que acontece cando a sesión recibe este sinal de desbloqueo non están definidos e é específico da sesión. Porén, a maioría das sesións desbloquearán o protector de pantalla en resposta.</para>

    <para>Cando o usuario queira saír da sesión, ou se GDM ou a sesión saen de forma inesperada a sesión do usuario desrexistrarase desde ConsoleKit.</para>
  </sect1>

  <!-- ============= Configuration ============================= -->

  <sect1 id="configuration">
    <title>Configuración</title>

    <para>GDM ten un conxunto de interfaces de configuración. Isto inclúe puntos de integración de scripting, configuración do «daemon», configuración da pantalla de benvida, configuracións xerais da sesión, integración coas configuracións de «gnome-settings-daemon» e configuración da sesión. Estes tipos de integración descríbense en detalle embaixo.</para>

    <sect2 id="scripting">
      <title>Puntos de integración de scripts</title>
      
      <para>Os puntos de integración por script de GDM pódense atopar no cartafol <filename>&lt;etc&gt;/gdm/</filename>:</para>

<screen>
Xsession
Init/
PostLogin/
PreSession/
PostSession/
</screen>

      <para>Os scripts <filename>Init</filename>, <filename>PostLogin</filename>, <filename>PreSession</filename> e <filename>PostSession</filename> todos funcionan como se describe embaixo.</para>

      <para lang="en">
        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 <filename>Init</filename> script is 
        <filename>&lt;etc&gt;/gdm/Init/Default</filename>.  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 <filename>&lt;Init&gt;/:0</filename>
        script exists, it will be run for DISPLAY ":0".
     </para>

     <para lang="en">
        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.
      </para>

      <para lang="en">
        When the Xserver for the login GUI has been successfully started, but
        before the login GUI is actually displayed, GDM will run the
        <filename>Init</filename> 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.
      </para>

      <para lang="en">
        After the user has been successfully authenticated GDM will run the
        <filename>PostLogin</filename> 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.
      </para>

      <para lang="en">
        After the user session has been initialized, GDM will run the
        <filename>PreSession</filename> 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.
      </para>

      <para lang="en"> 
        When a user terminates their session, GDM will run the
        <filename>PostSession</filename> script.  Note that the Xserver will
        have been stopped by the time this script is run, so it should not be
        accessed.  
      </para>

      <para lang="en">
        Note that the <filename>PostSession</filename> 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.
      </para>

      <para lang="en">
        All of the above scripts will set the
        <filename>$RUNNING_UNDER_GDM</filename> environment variable to
        <filename>yes</filename>.  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.
      </para>
    </sect2>

    <sect2 id="autostart">
      <title>Configuración automática ao inicio</title>
      
      <para lang="en">
        The <filename>&lt;share&gt;/gdm/autostart/LoginWindow</filename>
        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.
      </para>

      <para lang="en">
        Any <filename>.desktop</filename> 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.
      </para>
    </sect2>

    <sect2 id="xsessionscript">
      <title>Script Xsession</title>

      <para lang="en">
        There is also an <filename>Xsession</filename> script located at
        <filename>&lt;etc&gt;/gdm/Xsession</filename> which is called between
        the <filename>PreSession</filename> and the
        <filename>PostSession</filename> 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. 
      </para>
    </sect2>

    <sect2 id="daemonconfig">
      <title>Configuración do «daemon»</title>

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

      <para lang="en">
        Note that older versions of GDM supported additional configuration
        options which are no longer supported in the latest versions of GDM.
      </para>

      <para lang="en">
        The <filename>&lt;etc&gt;/gdm/custom.conf</filename> file is in the
        <filename>keyfile</filename> 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.  
      </para>

      <para lang="en">
        The file <filename>&lt;etc&gt;/gdm/custom.conf</filename> 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:
      </para>
     
<screen>
[daemon]
TimedLoginEnable=true
TimedLogin=you
</screen>

      <para lang="en">
        A full list of supported configuration keys follow:
      </para>

      <sect3 id="choosersection">
        <title>[chooser]</title>
        <variablelist>

          <varlistentry>
            <term>Multicast</term>
            <listitem>
              <synopsis>Multicast=false</synopsis>
              <para>Se é verdadeiro e IPv6 está activado, o selector enviará unha consulta multicast á rede local e recollera as respostas dos equipos que están unidos ao grupo multicast.</para>
            </listitem>
          </varlistentry>
         
          <varlistentry>
            <term>MulticastAddr</term>
            <listitem>
              <synopsis>MulticastAddr=ff02::1</synopsis>
              <para>Este é o enderezo multicast de link local</para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="daemonsection">
        <title>[daemon]</title>
        <variablelist>
          <varlistentry>
            <term>TimedLoginEnable</term>
            <listitem>
              <synopsis>TimedLoginEnable=false</synopsis>
              <para lang="en">
                 If the user given in <filename>TimedLogin</filename> should be
                logged in after a number of seconds (set with
                <filename>TimedLoginDelay</filename>) 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 
                <filename>TimedLoginDelay</filename> 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-&gt;PAM"
                section of the manual for more information, or for help if this
                feature does not seem to work.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>TimedLogin</term>
            <listitem>
              <synopsis>TimedLogin=</synopsis>
              <para>Este é o usuario no que se debería iniciar sesión despois dun número especificado de segundos de inactividade.</para>
              <para lang="en">
                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.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>TimedLoginDelay</term>
            <listitem>
              <synopsis>TimedLoginDelay=30</synopsis>
              <para>Atraso en segundos antes de que o usuario <filename>TimedLogin</filename> se inicie sesión.</para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>AutomaticLoginEnable</term>
            <listitem>
              <synopsis>AutomaticLoginEnable=false</synopsis>
              <para lang="en">
                If true, the user given in <filename>AutomaticLogin</filename>
                should be logged in immediately. This feature is like timed
                login with a delay of 0 seconds.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>AutomaticLogin</term>
            <listitem>
              <synopsis>AutomaticLogin=</synopsis>
              <para lang="en">
                This is the user that should be logged in immediately if
                <filename>AutomaticLoginEnable</filename> is true.
              </para>
              <para lang="en">
                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.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>User</term>
            <listitem>
              <synopsis>User=gdm</synopsis>
              <para lang="en">
                The username under which the greeter and other GUI programs
                are run.  Refer to the <filename>Group</filename>
                configuration key and to the "Security-&gt;GDM User And
                Group" section of this document for more information.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Group</term>
            <listitem>
              <synopsis>Group=gdm</synopsis>
              <para lang="en">
                The group name under which the greeter and other GUI programs
                are run.  Refer to the <filename>User</filename>
                configuration key and to the "Security-&gt;GDM User And
                Group" section of this document for more information.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="debugsection">
        <title>Opcións de depuración</title>
      
        <variablelist>
          <title>[debug]</title>
          
          <varlistentry>
            <term>Enable</term>
            <listitem>
              <synopsis>Enable=false</synopsis>
              <para lang="en">
                To enable debugging, set the debug/Enable key to
                "true" in the
                <filename>&lt;etc&gt;/gdm/custom.conf</filename>
                file and restart GDM.  Then debug output will be sent to the
                system log file (<filename>&lt;var&gt;/log/messages</filename>
                or <filename>&lt;var&gt;/adm/messages</filename> depending on
                your Operating System).
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="greetersection">
        <title>Opcións da interface</title>
      
        <variablelist>
          <title>[greeter]</title>
          
          <varlistentry>
            <term>IncludeAll</term>
            <listitem>
              <synopsis>IncludeAll=true</synopsis>
              <para lang="en">
                If true, then the face browser will show all users on the local
                machine.  If false, the face browser will only show users who
                have recently logged in.
              </para>

              <para lang="en">
                When this key is true, GDM will call fgetpwent() to get a list
                of local users on the system.  Any users with a user id less
                than 500 (or 100 if running on Oracle Solaris) are filtered
                out.  The Face Browser also will display any users that have
                previously logged in on the system  (for example NIS/LDAP
                users).  It gets this list via calling the
                <command>ck-history</command> ConsoleKit interface.  It will
                also filter out any users which do not have a valid shell
                (valid shells are any shell that getusershell() returns -
                /sbin/nologin or /bin/false are considered invalid shells even
                if getusershell() returns them).
              </para>

              <para lang="en">
                If false, then GDM more simply only displays users that have
                previously logged in on the system (local or NIS/LDAP users) by
                calling the <command>ck-history</command> ConsoleKit interface.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Include</term>
            <listitem>
              <synopsis>Include=</synopsis>
              <para lang="en">
                Set to a list of users to always include in the Face Browser.
                This value is set to a list of users separated by commas.  By
                default, the value is empty.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Exclude</term>
            <listitem>
              <synopsis>Exclude=bin,root,daemon,adm,lp,sync,shutdown,halt,mail,news,uucp,operator,nobody,nobody4,noaccess,postgres,pvm,rpm,nfsnobody,pcap</synopsis>
              <para lang="en">
                Set to a list of users to always exclude in the Face Browser.
                This value is set to a list of users separated by commas.  Note
                that the setting in the <filename>custom.conf</filename>
                overrides the default value, so if you wish to add additional
                users to the list, then you need to set the value to the
                default value with additional users appended to the list.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="securitysection">
        <title>Opcións de seguranza</title>
      
        <variablelist>
          <title>[security]</title>
          
          <varlistentry>
            <term>DisallowTCP</term>
            <listitem>
              <synopsis>DisallowTCP=true</synopsis>
              <para lang="en">
                If true, then always append <filename>-nolisten tcp</filename>
                to the command line when starting attached Xservers, thus
                disallowing TCP connection.  This is a more secure
                configuration if you are not using remote connections.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="xdmcpsection">
        <title>Compatibilidade XDMCP</title>

        <variablelist>
          <title>[xdmcp]</title>
          
          <varlistentry>
            <term>DisplaysPerHost</term>
            <listitem>
              <synopsis>DisplaysPerHost=1</synopsis>
              <para lang="en">
                To prevent attackers from filling up the pending queue, GDM
                will only allow one connection for each remote computer.  If
                you want to provide display services to computers with more
                than one screen, you should increase this value.
              </para>

              <para lang="en">
                Note that the number of attached DISPLAYS allowed is not 
                limited.  Only remote connections via XDMCP are limited by
                this configuration option.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Enable</term>
            <listitem>
              <synopsis>Enable=false</synopsis>
              <para lang="en">
                Setting this to true enables XDMCP support allowing remote
                displays/X terminals to be managed by GDM.
              </para>
            
              <para lang="en">
                <filename>gdm</filename> listens for requests on UDP port 177.
                See the Port option for more information.
              </para>
              
              <para lang="en">
                If GDM is compiled to support it, access from remote displays
                can be controlled using the TCP Wrappers library. The service
                name is <filename>gdm</filename>
              </para>
            
              <para lang="en">
                You should add 
<screen lang="en">
gdm:.my.domain
</screen>
                to your <filename>&lt;etc&gt;/hosts.allow</filename>, depending
                on your TCP Wrappers configuration.  See the
                <ulink type="help" url="man:hosts.allow">hosts.allow</ulink>
                man page for details.
              </para>
              
              <para lang="en">
                Please note that XDMCP is not a particularly secure protocol
                and that it is a good idea to block UDP port 177 on your
                firewall unless you really need it.
              </para>
            </listitem>
          </varlistentry>
          
          <varlistentry>
            <term>HonorIndirect</term>
            <listitem>
              <synopsis>HonorIndirect=true</synopsis>
              <para lang="en">
                Enables XDMCP INDIRECT choosing (i.e. remote execution of
                <filename>gdmchooser</filename>) for X-terminals which do not
                supply their own display browser.
              </para>
            </listitem>
          </varlistentry>
        
          <varlistentry>
            <term>MaxPending</term>
            <listitem>
              <synopsis>MaxPending=4</synopsis>
              <para>Para evitar os ataques de denegación de servizos, GDM ten un tamaño de cola de conexións pendentes fixo. Só se poden iniciar MaxPending pantallas á vez.</para>
            
              <para lang="en">
                Please note that this parameter does not limit the number of
                remote displays which can be managed. It only limits the number
                of displays initiating a connection simultaneously.
              </para>
            </listitem>
          </varlistentry>
          
          <varlistentry>
            <term>MaxSessions</term>
            <listitem>
              <synopsis>MaxSessions=16</synopsis>
              <para lang="en">
                Determines the maximum number of remote display connections
                which will be managed simultaneously. I.e. the total number of
                remote displays that can use your host.
              </para>
            </listitem>
          </varlistentry>
        
          <varlistentry>
            <term>MaxWait</term>
            <listitem>
              <synopsis>MaxWait=30</synopsis>
              <para lang="en">
                When GDM is ready to manage a display an ACCEPT packet is sent
                to it containing a unique session id which will be used in
                future XDMCP conversations.
              </para>
            
              <para lang="en">
                GDM will then place the session id in the pending queue
                waiting for the display to respond with a MANAGE request.
              </para>
            
              <para lang="en">
                If no response is received within MaxWait seconds, GDM will
                declare the display dead and erase it from the pending queue
                freeing up the slot for other displays.
              </para>
            </listitem>
          </varlistentry>
          
          <varlistentry>
            <term>MaxWaitIndirect</term>
            <listitem>
              <synopsis>MaxWaitIndirect=30</synopsis>
              <para lang="en">
                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
                <filename>MaxPendingIndirect</filename>.
              </para>
            </listitem>
          </varlistentry>
        
          <varlistentry>
            <term>PingIntervalSeconds</term>
            <listitem>
              <synopsis>PingIntervalSeconds=60</synopsis>
              <para lang="en">
                If the Xserver does not respond in the specified number of
                seconds, then the connection is stopped and the session ended.
                When this happens the slave daemon dies with an ALARM signal.
                Note that GDM 2.20 and earlier multiplied this setting by 2,
                so it may be necessary to increase the timeout if upgrading
                from GDM 2.20 and earlier to a newer version.
              </para>

              <para lang="en">
                Note that GDM in the past used to have a
                <filename>PingInterval</filename> configuration key which was
                also in minutes.  For most purposes you'd want this setting
                to be lower than one minute. However since in most cases where
                XDMCP would be used (such as terminal labs), a lag of more
                than 15 or so seconds would really mean that the terminal was
                turned off or restarted and you would want to end the session.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Port</term>
            <listitem>
              <synopsis>Port=177</synopsis>
              <para lang="en">
                The UDP port number <filename>gdm</filename> should listen to
                for XDMCP requests. Do not change this unless you know what
                you are doing.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>Willing</term>
            <listitem>
              <synopsis>Willing=&lt;etc&gt;/gdm/Xwilling</synopsis>
              <para lang="en">
                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.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>
    </sect2>

    <sect2 id="greeterconfiguration">
        <title>Configuración da interface simple</title>

        <para lang="en">
          The GDM default greeter is called the simple Greeter and is
          configured via GConf.  Default values are stored in GConf in the
          <filename>gdm-simple-greeter.schemas</filename> 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 <command>gconftool-2</command> or <command>gconf-editor</command>
          programs.  The following configuration options are supported:
        </para>

        <variablelist>
          <title>Chaves de configuración da interface</title>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/banner_message_enable</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para>Controla se se mostra ou non o mensaxe de texto.</para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/banner_message_text</term>
            <listitem>
              <synopsis>NULL (cadea)</synopsis>
              <para lang="en">
                Specifies the text banner message to show on the greeter
                window.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/disable_restart_buttons</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                Controls whether to show the restart buttons in the login
                window.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/disable_user_list</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                If true, then the face browser with known users is not shown
                in the login window.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/logo_icon_name</term>
            <listitem>
              <synopsis>computer (cadea)</synopsis>
              <para lang="en">
                Set to the themed icon name to use for the greeter logo.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/recent-languages</term>
            <listitem>
              <synopsis>[] (lista de cadeas)</synopsis>
              <para lang="en">
                Set to a list of languages to be shown by default in the login
                window.  Default value is "[]".  With the default setting only
                the system default language is shown and the option "Other..."
                which pops-up a dialog box showing a full list of available
                languages which the user can select.
              </para>

              <para lang="en">
                Users are not intended to change this setting by hand.  Instead
                GDM keeps track of any languages selected in this configuration
                key, and will show them in the language combo box along with
                the "Other..." choice.  This way, commonly selected languages
                are easier to select.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/recent-layouts</term>
            <listitem>
              <synopsis>[] (lista de cadeas)</synopsis>
              <para lang="en">
                Set to a list of keyboard layouts to be shown by default in the
                login panel.  Default value is "[]".  With the default setting
                only the system default keyboard layout is shown and the option
                "Other..." which pops-up a dialog box showing a full list of
                available keyboard layouts which the user can select.
              </para>

              <para lang="en">
                Users are not intended to change this setting by hand.  Instead
                GDM keeps track of any keyboard layouts selected in this
                configuration key, and will show them in the keyboard layout
                combo box along with the "Other..." choice.  This way, commonly
                selected keyboard layouts are easier to select.
              </para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>/apps/gdm/simple-greeter/wm_use_compiz</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                Controls whether compiz is used as the window manager instead
                of metacity.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
    </sect2>

    <sect2 id="accessibilityconfiguration">
     <title>Configuración da accesibilidade</title>

      <para lang="en">
       This section describes the accessibility configuration options available
       in GDM.
      </para>

      <sect3 id="accessibilitydialog">
        <title lang="en">GDM Accessibility Dialog And GConf Keys</title>

        <para lang="en">
         The GDM greeter panel at the login screen displays an accessibility
         icon.  Clicking on that icon opens the GDM Accessibility Dialog.  In
         the GDM Accessibility Dialog, there is a list of checkboxes, so the
         user can enable or disable the associated assistive tools.
        </para>

        <para lang="en">
         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.
        </para>

        <para lang="en">
         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.
        </para>
      </sect3>

      <sect3 id="accessibilitygconfconfiguration">
        <title>Chaves de accesibilidade de GConf</title>

        <para lang="en">
         GDM offers the following GConf keys to control its accessibility
         features:
        </para>

        <variablelist>
          <title>Chaves de configuración de GDM</title>

          <varlistentry>
            <term>/desktop/gnome/interface/accessibility</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                Controls whether the Accessibility infrastructure will be
                started with the GDM GUI.  This is needed for many
                accessibility technology programs to work.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>/desktop/gnome/applications/at/screen_magnifier_enabled</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                If set, then the assistive tools linked to this GConf key will
                be started with the GDM GUI program.  By default this is a
                screen magnifier application.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>/desktop/gnome/applications/at/screen_keyboard_enabled</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                If set, then the assistive tools linked to this GConf key will
                be started with the GDM GUI program.  By default this is an
                on-screen keyboard application.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>/desktop/gnome/applications/at/screen_reader_enabled</term>
            <listitem>
              <synopsis>false (booleano)</synopsis>
              <para lang="en">
                If set, then the assistive tools linked to this GConf key will
                be started with the GDM GUI program.  By default this is a
                screen reader application.
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="accessibilitytoolsconfiguration">
        <title lang="en">Linking GConf Keys to Accessbility Tools</title>

        <para lang="en">
         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:
        </para>

<screen>
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
</screen>

        <para lang="en">
         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.
        </para>
      </sect3>

      <sect3 id="accessibilitytoolexample">
        <title lang="en">Example Of Modifying Accessibility Tool Configuration</title>

        <para lang="en">
         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.
        </para>

        <para lang="en">
         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.
        </para>

        <para>O seguinte é un exemplo de ficheiro <filename>onboard.desktop</filename>:</para>

<screen>
[Desktop Entry]
Encoding=UTF-8
Name=Teclado en pantalla
Comment=Usar un teclado en pantalla
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
</screen>

        <para>O seguinte é un exemplo de ficheiro <filename>mousetweaks.desktop</filename>:</para>

<screen lang="en">
[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
</screen>

        <para lang="en">
         Note the line with the AutostartCondition that links both desktop
         files to the GConf key for the on-screen keyboard.
        </para>

        <para lang="en">
         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.
        </para>

        <para lang="en">
         After making these changes, GOK will no longer be started when the
         user activates the on-screen keyboard in the GDM session; but onboard
         and mousetweaks will instead be launched.
        </para>
      </sect3>
    </sect2>

    <sect2 id="generalsessionconfig">
      <title>Configuracińo xeral de sesión</title>
<!--
<para>
          TODO - I think this section should be expanded upon.  What specific
                 keys are of interest, or would some users be likely to want
                 to configure?  Also, would be good to be more specific about
                 how lock down management is handled.
</para>
-->
        <para lang="en">
          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.
        </para>
    </sect2>

    <sect2 id="gnomesettingsdaemon">
      <title>«Daemon» de preferencias de GNOME</title>
<!--
<para>
          TODO - I think this section should be expanded upon.  What specific
                 keys are of interest, or would some users be likely to want
                 to configure?  Also, would be good to give a more complete
                 list of plugins that users might want to consider disabling.
                 Also, shouldn't we list the sound/active key in the Greeter
                 configuration setting?  Oddly I do not find this key used
                 in anything but the chooser in SVN.
</para>
-->

        <para>GDM conta cos seguintes engadidos de gnome-settings-daemon: a11y-keyboard, background, sound, xsettings.</para>

        <para lang="en">
          These are responsible for things like the background image, font and
          theme settings, sound events, etc.
        </para>

        <para lang="en">
          Plugins can also be disabled using GConf. For example, if you want to
          disable the sound plugin then unset the following key:
          <filename>/apps/gdm/simple-greeter/settings-manager-plugins/sound/active</filename>.
        </para>
    </sect2>

    <sect2 id="sessionconfig">
      <title>Configuración de sesión de GDM</title>

      <para lang="en">
        GDM sessions are specified using the FreeDesktop.org Desktop Entry
        Specification, which can be referenced at the following URL:
        <ulink url="http://www.freedesktop.org/wiki/Specifications/desktop-entry-spec">
        http://www.freedesktop.org/wiki/Specifications/desktop-entry-spec</ulink>.
      </para>

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

      <para lang="en">
        A session can be disabled by editing the desktop file and adding a line
        as follows: <filename>Hidden=true</filename>.
      </para>

      <para lang="en">
        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 <filename>&lt;etc&gt;/gdm/Xsession</filename> script, which is
        the normal behavior.  Since bypassing the
        <filename>&lt;etc&gt;/gdm/Xsession</filename> 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.
      </para>

    </sect2>

    <sect2 id="userconfig">
      <title>Sesión de usuario de GDM e preferencias de idioma</title>
      <para lang="en">
        The user's default session and language choices are stored in the
        <filename>~/.dmrc</filename> 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.
      </para>

      <para lang="en">
        The <filename>~/.dmrc</filename> file is in the standard
        <filename>INI</filename> format.  It has one section called
        <filename>[Desktop]</filename> which has two keys:
        <filename>Session</filename> and <filename>Language</filename>.
      </para>

      <para lang="en">
        The <filename>Session</filename> key specifies the basename of the
        session <filename>.desktop</filename> file that the user wishes to
        normally use without the <filename>.desktop</filename> extension.
        The <filename>Language</filename> 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:
      </para>

<screen>
[Desktop]
Session=gnome
Language=gl_ES.UTF-8
</screen>
    </sect2>

  </sect1>

  <!-- ============= GDM Commands ============================= -->

  <sect1 id="binaries">
    <title>Ordes de GDM</title>

    <sect2 id="sbindir_binaries">
      <title>Ordes do administrador de GDM</title>

      <para lang="en">
        The GDM package provides the following commands in
        <filename>sbindir</filename> intended to be run by the root user:
      </para>

      <sect3 id="gdmcommandline">
        <title>Opcións da liña de ordes de <command>gdm</command></title>

        <para><command>gdm</command> é o daemon principal que configura o ambiente de inicio de sesión gráfico e inicia os axudantes necesarios.</para>

        <variablelist>
          <title>Opcións da liña de ordes de <command>gdm</command></title>

          <varlistentry>
            <term>-?, --help</term>
            <listitem>
              <para>Fornece unha vista rápida das opcións de liña de ordes.</para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>--fatal-warnings</term>
            <listitem>
              <para>Facer todos os avisos que GDM saian.</para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>--timed-exit</term>
            <listitem>
              <para>Saír despois de 30 segundos. Útil para depuración.</para>
            </listitem>
          </varlistentry>

          <varlistentry>
            <term>--version</term>
            <listitem>
              <para>Imprime a versión do daemon GDM.</para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect3>

      <sect3 id="gdmrestartcommandline">
        <title>Opcións de liña de ordes de <command>gdm-restart</command></title>

        <para lang="en">
          <command>gdm-restart</command> stops and restarts GDM by sending
          the GDM daemon a HUP signal.  This command will immediately terminate
          all sessions and log out users currently logged in with GDM.
        </para>
      </sect3>

      <sect3 id="gdmsaferestartcommandline">
        <title>Opcións de liña de ordes de <command>gdm-safe-restart</command></title>
  
        <para><command>gdm-safe-restart</command> para e reinicia GDM enviando ao «daemon» GDM un sinal USR1. GDM reiniciarase tan pronto como todos os usuarios saian.</para>
      </sect3>

      <sect3 id="gdmstopcommandline">
        <title>Opcións da liña de ordes de <command>gdm-stop</command></title>

        <para><command>gdm-stop</command> para GDM enviando ao «daemon» GDM un sinal TERM.</para>
      </sect3>
    </sect2>
  </sect1>

  <!-- ============= Troubleshooting =========================== -->

  <sect1 id="troubleshooting">
    <title>Resolución de problemas</title>
<!--
<para>
      TODO - any other tips we should add?  Might be useful to highlight any
             common D-Bus configuration issues?
</para>
-->

    <para lang="en">
      This section discusses helpful tips for getting GDM working.  In general,
      if you have a problem using GDM, you can submit a bug or send an email
      to the gdm-list mailing list.  Information about how to do this is in
      the Introduction section of the document.
    </para>

    <para lang="en">
      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 <filename>&lt;etc&gt;/gdm/custom.conf</filename>
      file and restart GDM.  Then use GDM to the point where it fails, and
      debug output will be sent to the system log file
      (<filename>&lt;var&gt;/log/messages</filename> or
      <filename>&lt;var&gt;/adm/messages</filename> 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
      <ulink type="help" url="man:syslog">syslog</ulink> man page).
    </para>

    <sect2 id="wontstart">
      <title>GDM non se inicia</title>

      <para lang="en">
         There are a many problems that can cause GDM to fail to start, but
         this section will discuss a few common problems and how to approach
         tracking down a problem with GDM starting.   Some problems will 
         cause GDM to respond with an error message or dialog when it tries
         to start, but it can be difficult to track down problems when GDM
         fails silently.
      </para>

      <para lang="en">
         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.
      </para>

      <para lang="en">
         Also make sure that the <filename>/tmp</filename> directory has
         reasonable ownership and permissions, and that the machine's file
         system is not full.  These problems will cause GDM to fail to start.
      </para>
    </sect2>
  </sect1>

  <!-- ============= Application License ============================= -->

  <sect1 id="license">
    <title>Licenza</title>
    <para lang="en">
      This program is free software; you can redistribute it and/or
      modify it under the terms of the  <ulink type="help" url="gnome-help:gpl">
      <citetitle>GNU General Public License</citetitle></ulink> as
      published by the Free Software Foundation; 
      either version 2 of the License, or (at your option) any later
      version.
    </para>
    <para lang="en">
      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
      <citetitle>GNU General Public License</citetitle> for more details.
    </para>
    <para lang="en">
      A copy of the <citetitle>GNU General Public License</citetitle> is
      included as an appendix to the <citetitle>GNOME Users
      Guide</citetitle>.  You may also obtain a copy of the
      <citetitle>GNU General Public License</citetitle> from the Free
      Software Foundation by visiting
      <ulink type="http" url="http://www.fsf.org">their Web site</ulink> or by
      writing to
      <address lang="en">
      Free Software Foundation, Inc.
      <street>51 Franklin Street, Fifth Floor</street>
      <city>Boston</city>, <state>MA</state> <postcode>02110-1301</postcode>
      <country>USA</country>
      </address>
    </para>
  </sect1>
</article>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:2
sgml-indent-data:t
sgml-parent-document:nil
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
-->
