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<refpurpose>wpa_supplicant privilege separation helper</refpurpose>
<arg>-c <replaceable>ctrl path</replaceable></arg>
<arg>-P <replaceable>pid file</replaceable></arg>
<arg>driver:ifname <replaceable>[driver:ifname ...]</replaceable></arg>
<para><command>wpa_priv</command> is a privilege separation helper that
minimizes the size of <command>wpa_supplicant</command> code that needs
to be run with root privileges.</para>
<para>If enabled, privileged operations are done in the wpa_priv process
while leaving rest of the code (e.g., EAP authentication and WPA
handshakes) to operate in an unprivileged process (wpa_supplicant) that
can be run as non-root user. Privilege separation restricts the effects
of potential software errors by containing the majority of the code in an
unprivileged process to avoid the possibility of a full system
<para><command>wpa_priv</command> needs to be run with network admin
privileges (usually, root user). It opens a UNIX domain socket for each
interface that is included on the command line; any other interface will
be off limits for <command>wpa_supplicant</command> in this kind of
configuration. After this, <command>wpa_supplicant</command> can be run as
a non-root user (e.g., all standard users on a laptop or as a special
non-privileged user account created just for this purpose to limit access
to user files even further).</para>
<title>Example configuration</title>
<para>The following steps are an example of how to configure
<command>wpa_priv</command> to allow users in the
<emphasis>wpapriv</emphasis> group to communicate with
<command>wpa_supplicant</command> with privilege separation:</para>
<para>Create user group (e.g., wpapriv) and assign users that
should be able to use wpa_supplicant into that group.</para>
<para>Create /var/run/wpa_priv directory for UNIX domain sockets and
control user access by setting it accessible only for the wpapriv
mkdir /var/run/wpa_priv
chown root:wpapriv /var/run/wpa_priv
chmod 0750 /var/run/wpa_priv
<para>Start <command>wpa_priv</command> as root (e.g., from system
startup scripts) with the enabled interfaces configured on the
command line:</para>
wpa_priv -B -c /var/run/wpa_priv -P /var/run/ wext:wlan0
<para>Run <command>wpa_supplicant</command> as non-root with a user
that is in the wpapriv group:</para>
wpa_supplicant -i ath0 -c wpa_supplicant.conf
<title>Command Arguments</title>
<term>-c ctrl path</term>
<listitem><para>Specify the path to wpa_priv control directory
(Default: /var/run/wpa_priv/).</para></listitem>
<listitem><para>Run as a daemon in the background.</para></listitem>
<term>-P file</term>
<listitem><para>Set the location of the PID
<term>driver:ifname [driver:ifname ...]</term>
<listitem><para>The &lt;driver&gt; string dictates which of the
supported <command>wpa_supplicant</command> driver backends is to be
used. To get a list of supported driver types see wpa_supplicant help
(e.g, wpa_supplicant -h). The driver backend supported by most good
drivers is <emphasis>wext</emphasis>.</para>
<para>The &lt;ifname&gt; string specifies which network
interface is to be managed by <command>wpa_supplicant</command>
(e.g., wlan0 or ath0).</para>
<para><command>wpa_priv</command> does not use the network interface
before <command>wpa_supplicant</command> is started, so it is fine to
include network interfaces that are not available at the time wpa_priv
is started. wpa_priv can control multiple interfaces with one process,
but it is also possible to run multiple <command>wpa_priv</command>
processes at the same time, if desired.</para></listitem>
<title>See Also</title>
<para>wpa_supplicant is copyright (c) 2003-2012,
Jouni Malinen <email></email> and
All Rights Reserved.</para>
<para>This program is licensed under the BSD license (the one with
advertisement clause removed).</para>