path: root/man/nslcd.conf.5.xml

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   nslcd.conf.5.xml - docbook manual page for nslcd.conf

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<refentry id="nssldapdconf5">

 <refentryinfo>
  <author>
   <firstname>Arthur</firstname>
   <surname>de Jong</surname>
  </author>
 </refentryinfo>

 <refmeta>
  <refentrytitle>nslcd.conf</refentrytitle>
  <manvolnum>5</manvolnum>
  <refmiscinfo class="version">Version 0.8.6</refmiscinfo>
  <refmiscinfo class="manual">System Manager's Manual</refmiscinfo>
  <refmiscinfo class="date">Jan 2012</refmiscinfo>
 </refmeta>

 <refnamediv id="name">
  <refname>nslcd.conf</refname>
  <refpurpose>configuration file for LDAP nameservice daemon</refpurpose>
 </refnamediv>

 <refsect1 id="description">
  <title>Description</title>
  <para>
   The <emphasis>nss-pam-ldapd</emphasis> package allows <acronym>LDAP</acronym>
   directory servers to be used as a primary source of name service
   information. (Name service information typically includes users, hosts,
   groups, and other such data historically stored in flat files or
   <acronym>NIS</acronym>.)
  </para>
  <para>
    The file <filename>nslcd.conf</filename> contains the
    configuration information for running <command>nslcd</command> (see
    <citerefentry><refentrytitle>nslcd</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
    The file contains options, one on each line, defining the way
    <acronym>NSS</acronym> lookups and <acronym>PAM</acronym> actions
    are mapped to <acronym>LDAP</acronym> lookups.
  </para>
 </refsect1>

 <refsect1 id="options">
  <title>Options</title>

  <refsect2 id="runtime_options">
   <title>Runtime options</title>
   <variablelist>

    <varlistentry id="threads">
     <term><option>threads</option> <replaceable>NUM</replaceable></term>
     <listitem>
      <para>
       Specifies the number of threads to start that can handle requests
       and perform <acronym>LDAP</acronym> queries.
       The default is to start 5 threads.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="uid">
     <term><option>uid</option> <replaceable>UID</replaceable></term>
     <listitem>
      <para>
       This specifies the user id with which the daemon should be run.
       This can be a numerical id or a symbolic value.
       If no uid is specified no attempt to change the user will be made.
       Note that you should use values that don't need <acronym>LDAP</acronym>
       to resolve.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="gid">
     <term><option>gid</option> <replaceable>GID</replaceable></term>
     <listitem>
      <para>
       This specifies the group id with which the daemon should be run.
       This can be a numerical id or a symbolic value.
       If no gid is specified no attempt to change the group will be made.
       Note that you should use values that don't need <acronym>LDAP</acronym>
       to resolve.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="general_connection_options">
   <title>General connection options</title>
   <variablelist>

    <varlistentry id="uri">
     <term><option>uri</option> <replaceable>URI</replaceable></term>
     <listitem>
      <para>
       Specifies the <acronym>LDAP</acronym> <acronym>URI</acronym> of the
       server to connect to.
       The <acronym>URI</acronym> scheme may be <literal>ldap</literal>,
       <literal>ldapi</literal> or <literal>ldaps</literal>, specifying
       <acronym>LDAP</acronym> over <acronym>TCP</acronym>,
       <acronym>ICP</acronym> or <acronym>SSL</acronym> respectively (if
       supported by the <acronym>LDAP</acronym> library).
      </para>
      <para>
       Alternatively, the value <literal>DNS</literal> may be
       used to try to lookup the server using <acronym>DNS</acronym>
       <acronym>SRV</acronym> records.
       By default the current domain is used but another domain can
       be queried by using the
       <literal>DNS:</literal><replaceable>DOMAIN</replaceable> syntax.
      </para>
      <para>
       When using the ldapi scheme, %2f should be used to escape slashes
       (e.g. ldapi://%2fvar%2frun%2fslapd%2fldapi/), although most of the
       time this should not be needed.
      </para>
      <para>
       This option may be specified multiple times. Normally, only the first
       server will be used with the following servers as fall-back (see
       <option>bind_timelimit</option> below).
      </para>
      <para>
       If <acronym>LDAP</acronym> lookups are used for host name resolution,
       any host names should be specified as an IP address or name that can be
       resolved without using <acronym>LDAP</acronym>.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="ldap_version">
     <term><option>ldap_version</option> <replaceable>VERSION</replaceable></term>
     <listitem>
      <para>
       Specifies the version of the <acronym>LDAP</acronym> protocol to use.
       The default is to use the maximum version supported by the
       <acronym>LDAP</acronym> library.</para>
     </listitem>
    </varlistentry>

    <varlistentry id="binddn">
     <term><option>binddn</option> <replaceable>DN</replaceable></term>
     <listitem>
      <para>
       Specifies the distinguished name with which to bind to the directory
       server for lookups.
       The default is to bind anonymously.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="bindpw">
     <term><option>bindpw</option> <replaceable>PASSWORD</replaceable></term>
     <listitem>
      <para>
       Specifies the credentials with which to bind.
       This option is only applicable when used with <option>binddn</option> above.
       If you set this option you should consider changing the permissions
       of the <filename>nslcd.conf</filename> file to only grant access to
       the root user.
<!-- WHEN SASL IS DOCUMENTED:
       This option is only applicable when either the <option>binddn</option> or
       <option>sasl_authcid</option> options are used.
-->
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="rootpwmoddn">
     <term><option>rootpwmoddn</option> <replaceable>DN</replaceable></term>
     <listitem>
      <para>
       Specifies the distinguished name to use when the root user tries to
       modify a user's password using the PAM module.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="rootpwmodpw">
     <term><option>rootpwmodpw</option> <replaceable>PASSWORD</replaceable></term>
     <listitem>
      <para>
       Specifies the credentials with which to bind if the root
       user tries to change a user's password.
       This option is only applicable when used with
       <option>rootpwmoddn</option> above.
       If this option is not specified the PAM module prompts the user for
       this password.
       If you set this option you should consider changing the permissions
       of the <filename>nslcd.conf</filename> file to only grant access to
       the root user.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="sasl_authentication_options">
   <title><acronym>SASL</acronym> authentication options</title>
   <variablelist>

    <varlistentry id="sasl_mech">
     <term><option>sasl_mech</option> <replaceable>MECHANISM</replaceable></term>
     <listitem>
      <para>
       Specifies the <acronym>SASL</acronym> mechanism to be used when
       performing <acronym>SASL</acronym> authentication.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="sasl_realm">
     <term><option>sasl_realm</option> <replaceable>REALM</replaceable></term>
     <listitem>
      <para>
       Specifies the <acronym>SASL</acronym> realm to be used when performing
       <acronym>SASL</acronym> authentication.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="sasl_authcid">
     <term><option>sasl_authcid</option> <replaceable>AUTHCID</replaceable></term>
     <listitem>
      <para>
       Specifies the authentication identity to be used when performing
       <acronym>SASL</acronym> authentication.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="sasl_authzid">
     <term><option>sasl_authzid</option> <replaceable>AUTHZID</replaceable></term>
     <listitem>
      <para>
       Specifies the authorization identity to be used when performing
       <acronym>SASL</acronym> authentication.
       Must be specified in one of the formats: dn:&lt;distinguished name&gt;
       or u:&lt;username&gt;.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="sasl_secprops">
     <term><option>sasl_secprops</option> <replaceable>PROPERTIES</replaceable></term>
     <listitem>
      <para>
       Specifies Cyrus <acronym>SASL</acronym> security properties.
       Allowed values are described in the
       <citerefentry><refentrytitle>ldap.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
       manual page.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="kerberos_authentication_options">
   <title>Kerberos authentication options</title>
   <variablelist>

    <varlistentry id="krb5_ccname">
     <term><option>krb5_ccname</option> <replaceable>NAME</replaceable></term>
     <listitem>
      <para>
       Set the name for the GSS-API Kerberos credentials cache.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="search_mapping_options">
   <title>Search/mapping options</title>
   <variablelist>

    <varlistentry id="base">
     <term><option>base</option>
           <optional><replaceable>MAP</replaceable></optional>
           <replaceable>DN</replaceable></term>
     <listitem>
      <para>
       Specifies the base distinguished name (<acronym>DN</acronym>)
       to use as search base.
       This option may be supplied multiple times and all specified bases
       will be searched.
      </para>
      <para>
       A global search base may be specified or a MAP-specific one.
       If no MAP-specific search bases are defined the global ones are used.
      </para>
      <para>
       If, instead of a <acronym>DN</acronym>, the value
       <replaceable>DOMAIN</replaceable> is specified, the host's
       <acronym>DNS</acronym> domain is used to construct a search base.
      </para>
      <para>
       If this value is not defined an attempt is made to look it up
       in the configured <acronym>LDAP</acronym> server. Note that if the
       <acronym>LDAP</acronym> server is unavailable during start-up
       <command>nslcd</command> will not start.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="scope">
     <term><option>scope</option>
           <optional><replaceable>MAP</replaceable></optional>
           sub<optional>tree</optional>|one<optional>level</optional>|base</term>
     <listitem>
      <para>
       Specifies the search scope (subtree, one level or base object).
       The default scope is subtree; base scope is almost never useful for
       name service lookups.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="deref">
     <term><option>deref</option> never|searching|finding|always</term>
     <listitem>
      <para>
       Specifies the policy for dereferencing aliases.
       The default policy is to never dereference aliases.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="referrals">
     <term><option>referrals</option> yes|no</term>
     <listitem>
      <para>
       Specifies whether automatic referral chasing should be enabled.
       The default behaviour is to chase referrals.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="filter">
     <term><option>filter</option>
           <replaceable>MAP</replaceable>
           <replaceable>FILTER</replaceable></term>
     <listitem>
      <para>
       The <replaceable>FILTER</replaceable>
       is an <acronym>LDAP</acronym> search filter to use for a
       specific map.
       The default filter is a basic search on the
       objectClass for the map (e.g. <literal>(objectClass=posixAccount)</literal>).
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="map">
     <term><option>map</option>
           <replaceable>MAP</replaceable>
           <replaceable>ATTRIBUTE</replaceable>
           <replaceable>NEWATTRIBUTE</replaceable></term>
     <listitem>
      <para>
       This option allows for custom attributes to be looked up instead of
       the default RFC 2307 attributes.
       The <replaceable>MAP</replaceable> may be one of
       the supported maps below.
       The <replaceable>ATTRIBUTE</replaceable> is the one as
       used in <acronym>RFC</acronym> 2307 (e.g. <literal>userPassword</literal>,
       <literal>ipProtocolNumber</literal>, <literal>macAddress</literal>, etc.).
       The <replaceable>NEWATTRIBUTE</replaceable> may be any attribute
       as it is available in the directory.
      </para>
      <para>
       If the <replaceable>NEWATTRIBUTE</replaceable> is presented in
       quotes (") it is treated as an expression which will be evaluated
       to build up the actual value used.
       See the section on attribute mapping expressions below for more details.
      </para>
      <para>
       Only some attributes for group, passwd and shadow entries may be mapped
       with an expression (because other attributes may be used in search
       filters).
       For group entries only the <literal>userPassword</literal> attribute
       may be mapped with an expression.
       For passwd entries the following attributes may be mapped with an
       expression: <literal>userPassword</literal>, <literal>gidNumber</literal>,
       <literal>gecos</literal>, <literal>homeDirectory</literal> and
       <literal>loginShell</literal>.
       For shadow entries the following attributes may be mapped with an
       expression: <literal>userPassword</literal>, <literal>shadowLastChange</literal>,
       <literal>shadowMin</literal>, <literal>shadowMax</literal>,
       <literal>shadowWarning</literal>, <literal>shadowInactive</literal>,
       <literal>shadowExpire</literal> and <literal>shadowFlag</literal>.
      </para>
      <para>
       The <literal>uidNumber</literal> and <literal>gidNumber</literal>
       attributes in the <literal>passwd</literal> and <literal>group</literal>
       maps may be mapped to the <literal>objectSid</literal> followed by
       the domain SID to derive numeric user and group ids from the SID
       (e.g. <literal>objectSid:S-1-5-21-3623811015-3361044348-30300820</literal>).
      </para>
      <para>
       By default all <literal>userPassword</literal> attributes are mapped
       to the unmatchable password ("*") to avoid accidentally leaking
       password information.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="timing_reconnect_options">
   <title>Timing/reconnect options</title>
   <variablelist>

    <varlistentry id="bind_timelimit">
     <term><option>bind_timelimit</option> <replaceable>SECONDS</replaceable></term>
     <listitem>
      <para>
       Specifies the time limit (in seconds) to use when connecting to the
       directory server.
       This is distinct from the time limit specified in
       <option>timelimit</option> and affects the set-up of the connection only.
       Note that not all <acronym>LDAP</acronym> client libraries have support
       for setting the connection time out.
       The default <option>bind_timelimit</option> is 10 seconds.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="timelimit">
     <term><option>timelimit</option> <replaceable>SECONDS</replaceable></term>
     <listitem>
      <para>
       Specifies the time limit (in seconds) to wait for a response from the
       <acronym>LDAP</acronym> server.
       A value of zero (0), which is the default, is to wait indefinitely for
       searches to be completed.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="idle_timelimit">
     <term><option>idle_timelimit</option> <replaceable>SECONDS</replaceable></term>
     <listitem>
      <para>
       Specifies the period if inactivity (in seconds) after which the
       connection to the <acronym>LDAP</acronym> server will be closed.
       The default is not to time out connections.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="reconnect_sleeptime">
     <term><option>reconnect_sleeptime</option> <replaceable>SECONDS</replaceable></term>
     <listitem>
      <para>
       Specifies the number of seconds to sleep when connecting to all
       <acronym>LDAP</acronym> servers fails.
       By default 1 second is waited between the first failure and the first
       retry.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="reconnect_retrytime">
     <term><option>reconnect_retrytime</option> <replaceable>SECONDS</replaceable></term>
     <listitem>
      <para>
       Specifies the time after which the <acronym>LDAP</acronym> server is
       considered to be permanently unavailable.
       Once this time is reached retries will be done only once per this time period.
       The default value is 10 seconds.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>

   <para>
    Note that the reconnect logic as described above is the mechanism that
    is used between <command>nslcd</command> and the <acronym>LDAP</acronym>
    server. The mechanism between the <acronym>NSS</acronym> and
    <acronym>PAM</acronym> client libraries on one end and
    <command>nslcd</command> on the other is simpler with a fixed compiled-in
    time out of a 10 seconds for writing to <command>nslcd</command> and
    a time out of 60 seconds for reading answers.
    <command>nslcd</command> itself has a read time out of 0.5 seconds
    and a write time out of 60 seconds.
   </para>

  </refsect2>

  <refsect2 id="ssl_tls_options">
   <title><acronym>SSL</acronym>/<acronym>TLS</acronym> options</title>
   <variablelist>

    <varlistentry id="ssl">
     <term><option>ssl</option> on|off|start_tls</term>
     <listitem>
      <para>
       Specifies whether to use <acronym>SSL</acronym>/<acronym>TLS</acronym> or not (the default is not to). If
       <replaceable>start_tls</replaceable>
       is specified then StartTLS is used rather than raw <acronym>LDAP</acronym> over <acronym>SSL</acronym>.
       Not all <acronym>LDAP</acronym> client libraries support both <acronym>SSL</acronym>,
       StartTLS and all related configuration options.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_reqcert">
     <term><option>tls_reqcert</option> never|allow|try|demand|hard</term>
     <listitem>
      <para>
       Specifies what checks to perform on a server-supplied certificate.
       The meaning of the values is described in the
       <citerefentry><refentrytitle>ldap.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
       manual page.
       At least one of <option>tls_cacertdir</option> and
       <option>tls_cacertfile</option> is required if peer verification is
       enabled.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_cacertdir">
     <term><option>tls_cacertdir</option> <replaceable>PATH</replaceable></term>
     <listitem>
      <para>
       Specifies the directory containing X.509 certificates for peer
       authentication.
       This parameter is ignored when using GnuTLS.
       On Debian OpenLDAP is linked against GnuTLS.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_cacertfile">
     <term><option>tls_cacertfile</option> <replaceable>PATH</replaceable></term>
     <listitem>
      <para>
       Specifies the path to the X.509 certificate for peer authentication.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_randfile">
     <term><option>tls_randfile</option> <replaceable>PATH</replaceable></term>
     <listitem>
      <para>
       Specifies the path to an entropy source.
       This parameter is ignored when using GnuTLS.
       On Debian OpenLDAP is linked against GnuTLS.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_ciphers">
     <term><option>tls_ciphers</option> <replaceable>CIPHERS</replaceable></term>
     <listitem>
      <para>
       Specifies the ciphers to use for <acronym>TLS</acronym>.
       See your <acronym>TLS</acronym> implementation's
       documentation for further information.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_cert">
     <term><option>tls_cert</option> <replaceable>PATH</replaceable></term>
     <listitem>
      <para>
       Specifies the path to the file containing the local certificate for
       client <acronym>TLS</acronym> authentication.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="tls_key">
     <term><option>tls_key</option> <replaceable>PATH</replaceable></term>
     <listitem>
      <para>
       Specifies the path to the file containing the private key for client
       <acronym>TLS</acronym> authentication.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

  <refsect2 id="other_options">
   <title>Other options</title>
   <variablelist>

<!-- do not document this option for now as support it is not finalized
    <varlistentry id="restart">
     <term><option>restart</option> yes|no</term>
     <listitem>
      <para>
       Specifies whether the <acronym>LDAP</acronym>
       client library should restart the
       <emphasis remap="B">select()</emphasis>
       system call when interrupted. This feature is not supported by all
       client libraries.
      </para>
     </listitem>
    </varlistentry>
-->

    <varlistentry id="pagesize">
     <term><option>pagesize</option> <replaceable>NUMBER</replaceable></term>
     <listitem>
      <para>
       Set this to a number greater than 0 to request paged results from
       the <acronym>LDAP</acronym> server in accordance with RFC2696.
       The default (0) is to not request paged results.
      </para>
      <para>
       This is useful for <acronym>LDAP</acronym> servers that contain a
       lot of entries (e.g. more than 500) and limit the number of entries
       that are returned with one request.
       For OpenLDAP servers you may need to set
       <option>sizelimit size.prtotal=unlimited</option>
       for allowing more entries to be returned over multiple pages.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="nss_initgroups_ignoreusers">
     <term><option>nss_initgroups_ignoreusers</option> user1,user2,...</term>
     <listitem>
      <para>
       This option prevents group membership lookups through
       <acronym>LDAP</acronym> for the specified users. This can be useful
       in case of unavailability of the <acronym>LDAP</acronym> server.
       This option may be specified multiple times.
      </para>
      <para>
       Alternatively, the value <literal>ALLLOCAL</literal> may be
       used. With that value nslcd builds a full list of
       non-<acronym>LDAP</acronym> users on startup.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="nss_min_uid">
     <term><option>nss_min_uid</option> <replaceable>UID</replaceable></term>
     <listitem>
      <para>
       This option ensures that <acronym>LDAP</acronym> users with a numeric
       user id lower than the specified value are ignored. Also requests for
       users with a lower user id are ignored.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="validnames">
     <term><option>validnames</option> <replaceable>REGEX</replaceable></term>
     <listitem>
      <para>
       This option can be used to specify how user and group names are
       verified within the system. This pattern is used to check all user and
       group names that are requested and returned from <acronym>LDAP</acronym>.
      </para>
      <para>
       The regular expression should be specified as a POSIX extended regular
       expression. The expression itself needs to be separated by slash (/)
       characters and the 'i' flag may be appended at the end to indicate
       that the match should be case-insensetive.
       The default value is
       <literal>/^[a-z0-9._@$][a-z0-9._@$ \\~-]*[a-z0-9._@$~-]$/i</literal>
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="pam_authz_search">
     <term><option>pam_authz_search</option>
           <replaceable>FILTER</replaceable></term>
     <listitem>
      <para>
       This option allows flexible fine tuning of the authorisation check that
       should be performed. The search filter specified is executed and
       if any entries match, access is granted, otherwise access is denied.
      </para>
      <para>
       The search filter can contain the following variable references:
         <literal>$username</literal>, <literal>$service</literal>,
         <literal>$ruser</literal>, <literal>$rhost</literal>,
         <literal>$tty</literal>, <literal>$hostname</literal>,
         <literal>$fqdn</literal>,
         <literal>$dn</literal>, and <literal>$uid</literal>.
       These references are substituted in the search filter using the
       same syntax as described in the section on attribute mapping
       expressions below.
      </para>
      <para>
       For example, to check that the user has a proper <literal>authorizedService</literal>
       value if the attribute is present (this almost emulates the
       <option>pam_check_service_attr</option> option in PADL's pam_ldap):
       <literallayout><literal>(&amp;(objectClass=posixAccount)(uid=$username)(|(authorizedService=$service)(!(authorizedService=*))))</literal></literallayout>
      </para>
      <para>
       The <option>pam_check_host_attr</option> option can be emulated with:
       <literallayout><literal>(&amp;(objectClass=posixAccount)(uid=$username)(|(host=$hostname)(host=$fqdn)(host=\\*)))</literal></literallayout>
      </para>
      <para>
       The default behaviour is not to do this extra search and always
       grant access.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </refsect2>

 </refsect1>

 <refsect1 id="maps">
  <title>Supported maps</title>
  <para>
   The following maps are supported. They are referenced as
   <replaceable>MAP</replaceable> in the options above.
  </para>
  <variablelist remap="TP">
   <varlistentry>
    <term>alias<optional>es</optional></term>
    <listitem><para>
     Mail aliases.
     Note that most mail servers do not use the <acronym>NSS</acronym>
     interface for requesting mail aliases and parse
     <filename>/etc/aliases</filename> on their own.
    </para></listitem>
   </varlistentry>
   <varlistentry>
    <term>ether<optional>s</optional></term>
    <listitem><para>Ethernet numbers (mac addresses).</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>group</term>
    <listitem><para>Posix groups.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>host<optional>s</optional></term>
    <listitem><para>Host names.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>netgroup</term>
    <listitem><para>Host and user groups used for access control.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>network<optional>s</optional></term>
    <listitem><para>Network numbers.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>passwd</term>
    <listitem><para>Posix users.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>protocol<optional>s</optional></term>
    <listitem><para>Protocol definitions (like in <filename>/etc/protocols</filename>).</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>rpc</term>
    <listitem><para>Remote procedure call names and numbers.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>service<optional>s</optional></term>
    <listitem><para>Network service names and numbers.</para></listitem>
   </varlistentry>
   <varlistentry>
    <term>shadow</term>
    <listitem><para>Shadow user password information.</para></listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="attmappingexpressions">
  <title>Attribute mapping expressions</title>
  <para>
   For some attributes a mapping expression may be used to construct the
   resulting value.
   This is currently only possible for attributes that do
   not need to be used in search filters.
   The expressions are a subset of the double quoted string expressions in the
   Bourne (POSIX) shell.
   Instead of variable substitution, attribute lookups are done on the current
   entry and the attribute value is substituted.
   The following expressions are supported:
  </para>
  <variablelist remap="TP">
   <varlistentry>
    <term><literal>${attr}</literal> (or <literal>$attr</literal> for short)</term>
    <listitem><para>
     will substitute the value of the attribute
    </para></listitem>
   </varlistentry>
   <varlistentry>
    <term><literal>${attr:-word}</literal></term>
    <listitem><para>
     (use default) will substitbute the value of the attribute or, if the
     attribute is not set or empty substitute the word
    </para></listitem>
   </varlistentry>
   <varlistentry>
    <term><literal>${attr:+word}</literal></term>
    <listitem><para>
     (use alternative) will substitbute word if attribute is set, otherwise
     substitute the empty string
    </para></listitem>
   </varlistentry>
  </variablelist>
  <para>
   Quote (<literal>"</literal>), dollar (<literal>$</literal>) or
   backslash (<literal>\</literal>) characters should be escaped with a
   backslash (<literal>\</literal>).
  </para>
  <para>
   The <command>nslcd</command> daemon checks the expressions to figure
   out which attributes to fetch from <acronym>LDAP</acronym>.
   Some examples to demonstrate how these expressions may be used in
   attribute mapping:
  </para>
  <variablelist remap="TP">
   <varlistentry>
    <term><literal>"${shadowFlag:-0}"</literal></term>
    <listitem><para>
     use the <literal>shadowFlag</literal> attribute, using the
     value 0 as default
    </para></listitem>
   </varlistentry>
   <varlistentry>
    <term><literal>"${homeDirectory:-/home/$uid}"</literal></term>
    <listitem><para>
     use the <literal>uid</literal> attribute to build a
     <literal>homeDirectory</literal> value if that attribute is missing
    </para></listitem>
   </varlistentry>
   <varlistentry>
    <term><literal>"${isDisabled:+100}"</literal></term>
    <listitem><para>
     if the <literal>isDisabled</literal> attribute is set, return 100,
     otherwise leave value empty
    </para></listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="files">
  <title>Files</title>
  <variablelist remap="TP">
   <varlistentry>
    <term><filename>/etc/nslcd.conf</filename></term>
    <listitem><para>the main configuration file</para></listitem>
   </varlistentry>
   <varlistentry>
    <term><filename>/etc/nsswitch.conf</filename></term>
    <listitem><para>Name Service Switch configuration file</para></listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="see_also">
  <title>See Also</title>
  <para>
   <citerefentry><refentrytitle>nslcd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
   <citerefentry><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  </para>
 </refsect1>

 <refsect1 id="author">
  <title>Author</title>
  <para>This manual was written by Arthur de Jong &lt;arthur@arthurdejong.org&gt;
        and is based on the
        <citerefentry><refentrytitle>nss_ldap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        manual developed by PADL Software Pty Ltd.</para>
 </refsect1>

</refentry>