csu3_am335x/EVSE/GPL/linux-pam-1.5.2/modules/pam_wheel/pam_wheel.8.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
	"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">

<refentry id="pam_wheel">

  <refmeta>
    <refentrytitle>pam_wheel</refentrytitle>
    <manvolnum>8</manvolnum>
    <refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
  </refmeta>

  <refnamediv id="pam_wheel-name">
    <refname>pam_wheel</refname>
    <refpurpose>Only permit root access to members of group wheel</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis id="pam_wheel-cmdsynopsis">
      <command>pam_wheel.so</command>
      <arg choice="opt">
	debug
      </arg>
      <arg choice="opt">
        deny
      </arg>
      <arg choice="opt">
	group=<replaceable>name</replaceable>
      </arg>
      <arg choice="opt">
	root_only
      </arg>
      <arg choice="opt">
	trust
      </arg>
      <arg choice="opt">
	use_uid
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id="pam_wheel-description">
    <title>DESCRIPTION</title>
    <para>
      The pam_wheel PAM module is used to enforce the so-called
      <emphasis>wheel</emphasis> group. By default it permits
      access to the target user if the applicant user is a member of the
      <emphasis>wheel</emphasis> group. If no group with this name exist,
      the module is using the group with the group-ID
      <emphasis remap='B'>0</emphasis>.
    </para>
  </refsect1>

  <refsect1 id="pam_wheel-options">
    <title>OPTIONS</title>
    <variablelist>
      <varlistentry>
        <term>
          <option>debug</option>
        </term>
        <listitem>
          <para>
            Print debug information.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>deny</option>
        </term>
        <listitem>
          <para>
            Reverse the sense of the auth operation: if the user
            is trying to get UID 0 access and is a member of the
            wheel group (or the group of the <option>group</option> option),
            deny access. Conversely, if the user is not in the group, return
            PAM_IGNORE (unless <option>trust</option> was also specified,
            in which case we return PAM_SUCCESS).
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>group=<replaceable>name</replaceable></option>
        </term>
        <listitem>
          <para>
            Instead of checking the wheel or GID 0 groups, use
            the <option><replaceable>name</replaceable></option> group
            to perform the authentication.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>root_only</option>
        </term>
        <listitem>
          <para>
            The check for wheel membership is done only when the target user
            UID is 0.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>trust</option>
        </term>
        <listitem>
          <para>
            The pam_wheel module will return PAM_SUCCESS instead
            of PAM_IGNORE if the user is a member of the wheel group
            (thus with a little play stacking the modules the wheel
            members may be able to su to root without being prompted
            for a passwd).
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>use_uid</option>
        </term>
        <listitem>
          <para>
            The check will be done against the real uid of the calling process,
            instead of trying to obtain the user from the login session
            associated with the terminal in use.
          </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id="pam_wheel-types">
    <title>MODULE TYPES PROVIDED</title>
    <para>
      The <emphasis remap='B'>auth</emphasis> and
      <emphasis remap='B'>account</emphasis> module types are provided.
    </para>
  </refsect1>

  <refsect1 id='pam_wheel-return_values'>
    <title>RETURN VALUES</title>
    <variablelist>
      <varlistentry>
        <term>PAM_AUTH_ERR</term>
        <listitem>
           <para>
             Authentication failure.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>PAM_BUF_ERR</term>
        <listitem>
           <para>
             Memory buffer error.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>PAM_IGNORE</term>
        <listitem>
          <para>
            The return value should be ignored by PAM dispatch.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>PAM_PERM_DENY</term>
        <listitem>
          <para>
            Permission denied.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>PAM_SERVICE_ERR</term>
        <listitem>
          <para>
	    Cannot determine the user name.
          </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>PAM_SUCCESS</term>
        <listitem>
          <para>
            Success.
          </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>PAM_USER_UNKNOWN</term>
        <listitem>
          <para>
            User not known.
          </para>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1 id='pam_wheel-examples'>
    <title>EXAMPLES</title>
    <para>
      The root account gains access by default (rootok), only wheel
      members can become root (wheel) but Unix authenticate non-root
      applicants.
      <programlisting>
su      auth     sufficient     pam_rootok.so
su      auth     required       pam_wheel.so
su      auth     required       pam_unix.so
      </programlisting>
    </para>
  </refsect1>

  <refsect1 id='pam_wheel-see_also'>
    <title>SEE ALSO</title>
    <para>
      <citerefentry>
	<refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>
    </para>
  </refsect1>

  <refsect1 id='pam_wheel-author'>
    <title>AUTHOR</title>
      <para>
        pam_wheel was written by Cristian Gafton &lt;gafton@redhat.com&gt;.
      </para>
  </refsect1>

</refentry>