<refnamediv>
<refname>udev</refname>
- <refpurpose>Linux dynamic device management</refpurpose>
+ <refpurpose>Dynamic device management</refpurpose>
</refnamediv>
<refsect1><title>Description</title>
sources is provided by the library libudev.</para>
</refsect1>
- <refsect1><title>Rules files</title>
+ <refsect1><title>Rules Files</title>
<para>The udev rules are read from the files located in the
system rules directory <filename>/usr/lib/udev/rules.d</filename>,
the volatile runtime directory <filename>/run/udev/rules.d</filename>
and the local administration directory <filename>/etc/udev/rules.d</filename>.
All rules files are collectively sorted and processed in lexical order,
regardless of the directories in which they live. However, files with
- identical file names replace each other. Files in <filename>/etc</filename>
+ identical filenames replace each other. Files in <filename>/etc</filename>
have the highest priority, files in <filename>/run</filename> take precedence
over files with the same name in <filename>/lib</filename>. This can be
used to override a system-supplied rules file with a local file if needed;
a symlink in <filename>/etc</filename> with the same name as a rules file in
<filename>/lib</filename>, pointing to <filename>/dev/null</filename>,
- disables the rules file entirely.</para>
-
- <para>Rule files must have the extension <filename>.rules</filename>; other
- extensions are ignored.</para>
+ disables the rules file entirely. Rule files must have the extension
+ <filename>.rules</filename>; other extensions are ignored.</para>
<para>Every line in the rules file contains at least one key-value pair.
Except for empty lines or lines beginning with <literal>#</literal>, which are ignored.
</varlistentry>
</variablelist>
- <para>Most of the fields support shell-style pattern matching. The following
+ <para>Most of the fields support shell glob pattern matching. The following
pattern characters are supported:</para>
<variablelist>
<varlistentry>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>SECLABEL{<replaceable>module</replaceable>}</varname></term>
+ <listitem>
+ <para>Applies the specified Linux Security Module label to the device node.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>ATTR{<replaceable>key</replaceable>}</varname></term>
<listitem>
<para>Import the stored keys from the parent device by reading
the database entry of the parent device. The value assigned to
<option>IMPORT{parent}</option> is used as a filter of key names
- to import (with the same shell-style pattern matching used for
+ to import (with the same shell glob pattern matching used for
comparisons).</para>
</listitem>
</varlistentry>
<term><option>static_node=</option></term>
<listitem>
<para>Apply the permissions specified in this rule to the static device node with
- the specified name. Static device node creation can be requested by kernel modules.
- These nodes might not have a corresponding kernel device at the time systemd-udevd is
- started; they can trigger automatic kernel module loading.</para>
+ the specified name. Also, for every tag specified in this rule, create a symlink
+ in the directory
+ <filename>/run/udev/static_node-tags/<replaceable>tag</replaceable></filename>
+ pointing at the static device node with the specified name. Static device node
+ creation is performed by systemd-tmpfiles before systemd-udevd is started. The
+ static nodes might not have a corresponding kernel device; they are used to
+ trigger automatic kernel module loading when they are accessed.</para>
</listitem>
</varlistentry>
<varlistentry>
</variablelist>
</refsect1>
+ <refsect1><title>Hardware Database Files</title>
+ <para>The hwdb files are read from the files located in the
+ system hwdb directory <filename>/usr/lib/udev/hwdb.d</filename>,
+ the volatile runtime directory <filename>/run/udev/hwdb.d</filename>
+ and the local administration directory <filename>/etc/udev/hwdb.d</filename>.
+ All hwdb files are collectively sorted and processed in lexical order,
+ regardless of the directories in which they live. However, files with
+ identical filenames replace each other. Files in <filename>/etc</filename>
+ have the highest priority, files in <filename>/run</filename> take precedence
+ over files with the same name in <filename>/lib</filename>. This can be
+ used to override a system-supplied hwdb file with a local file if needed;
+ a symlink in <filename>/etc</filename> with the same name as a hwdb file in
+ <filename>/lib</filename>, pointing to <filename>/dev/null</filename>,
+ disables the hwdb file entirely. hwdb files must have the extension
+ <filename>.hwdb</filename>; other extensions are ignored.</para>
+
+ <para>The hwdb file contains data records consisting of matches and
+ associated key-value pairs. Every record in the hwdb starts with one or
+ more match string, specifying a shell glob to compare the database
+ lookup string against. Multiple match lines are specified in additional
+ consecutive lines. Every match line is compared indivdually, they are
+ combined by OR. Every match line must start at the first character of
+ the line.</para>
+
+ <para>The match lines are followed by one or more key-value pair lines, which
+ are recognized by a leading space character. The key name and value are separated
+ by <literal>=</literal>. An empty line signifies the end
+ of a record. Lines beginning with <literal>#</literal> are ignored.</para>
+
+ <para>The content of all hwdb files is read by
+ <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ and compiled to a binary database located at <filename>/etc/udev/hwdb.bin</filename>.
+ During runtime only the binary database is used.</para>
+ </refsect1>
+
+ <refsect1><title>Network Link Configuration</title>
+ <para>Network link configuration is performed by the <literal>net_setup_link</literal>
+ udev builtin.</para>
+
+ <para>The link files are read from the files located in the
+ system network directory <filename>/usr/lib/systemd/network</filename>,
+ the volatile runtime network directory <filename>/run/systemd/network</filename>
+ and the local administration network directory <filename>/etc/systemd/network</filename>.
+ Link files must have the extension <filename>.link</filename>; other extensions are ignored.
+ All link files are collectively sorted and processed in lexical order,
+ regardless of the directories in which they live. However, files with
+ identical filenames replace each other. Files in <filename>/etc</filename>
+ have the highest priority, files in <filename>/run</filename> take precedence
+ over files with the same name in <filename>/lib</filename>. This can be
+ used to override a system-supplied link file with a local file if needed;
+ a symlink in <filename>/etc</filename> with the same name as a link file in
+ <filename>/lib</filename>, pointing to <filename>/dev/null</filename>,
+ disables the link file entirely.</para>
+
+ <para>The link file contains a <literal>[Match]</literal> section, which
+ determines if a given link file may be applied to a given device; and a
+ <literal>[Link]</literal> section specifying how the device should be
+ configured. The first (in lexical order) of the link files that matches
+ a given device is applied.</para>
+
+ <para>A link file is said to match a device if each of the entries in the
+ <literal>[Match]</literal> section matches, or if the section is empty.
+ The following keys are accepted:</para>
+
+ <variablelist class='network-directives'>
+ <varlistentry>
+ <term><varname>MACAddress</varname></term>
+ <listitem>
+ <para>The hardware address.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Path</varname></term>
+ <listitem>
+ <para>The persistent path, as exposed by the udev property <literal>ID_PATH</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Driver</varname></term>
+ <listitem>
+ <para>The driver currently bound to the device, as exposed by the udev property <literal>DRIVER</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Type</varname></term>
+ <listitem>
+ <para>The device type, as exposed by the udev property <literal>DEVTYPE</literal>.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ <para>The <literal>[Link]</literal> section accepts the following keys:</para>
+
+ <variablelist class='network-directives'>
+ <varlistentry>
+ <term><varname>Description</varname></term>
+ <listitem>
+ <para>A description of the device.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Alias</varname></term>
+ <listitem>
+ <para>The <literal>ifalias</literal> is set to this value.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>MACAddressPolicy</varname></term>
+ <listitem>
+ <para>The policy by which the MAC address should be set. The available policies are:</para>
+ <variablelist>
+ <varlistentry>
+ <term><literal>persistent</literal></term>
+ <listitem>
+ <para>If the hardware has a persistent MAC address, as most hardware should, and this is used by
+ the kernel, nothing is done. Otherwise, a new MAC address is generated which is guaranteed to be
+ the same on every boot for the given machine and the given device, but which is otherwise random.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>random</literal></term>
+ <listitem>
+ <para>If the kernel is using a random MAC address, nothing is done. Otherwise, a new address is
+ randomly generated each time the device appears, typically at boot.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>MACAddress</varname></term>
+ <listitem>
+ <para>The MAC address to use, if no <literal>MACAddressPolicy</literal> is specified.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>NamePolicy</varname></term>
+ <listitem>
+ <para>An ordered, space-separated list of policies by which the interface name should be set.
+ <literal>NamePolicy</literal> may be disabeld by specifying <literal>net.ifnames=0</literal> on the
+ kernel commandline. Each of the policies may fail, and the first successfull one is used. The name
+ is not set directly, but exported to udev as the property <literal>ID_NET_NAME</literal>, which is
+ by default used by an udev rule to set <literal>NAME</literal>. The available policies are:</para>
+ <variablelist>
+ <varlistentry>
+ <term><literal>onboard</literal></term>
+ <listitem>
+ <para>The name is set based on information given by the firmware for on-board devices, as
+ exported by the udev property <literal>ID_NET_NAME_ONBOARD</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>slot</literal></term>
+ <listitem>
+ <para>The name is set based on information given by the firmware for hot-plug devices, as
+ exported by the udev property <literal>ID_NET_NAME_SLOT</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>path</literal></term>
+ <listitem>
+ <para>The name is set based on the device's physical location, as exported by the udev
+ property <literal>ID_NET_NAME_PATH</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>mac</literal></term>
+ <listitem>
+ <para>The name is set based on the device's persistent MAC address, as exported by the udev
+ property <literal>ID_NET_NAME_MAC</literal>.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Name</varname></term>
+ <listitem>
+ <para>The interface name to use in case all the policies specified in <literal>NamePolicy</literal>
+ fail, or in case <literal>NamePolicy</literal> is missing or disabled.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>MTU</varname></term>
+ <listitem>
+ <para>The MTU to set for the device.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>SpeedMBytes</varname></term>
+ <listitem>
+ <para>The speed to set for the device.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Duplex</varname></term>
+ <listitem>
+ <para>The duplex mode to set for the device. The accepted values are <literal>half</literal> and
+ <literal>full</literal>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>WakeOnLan</varname></term>
+ <listitem>
+ <para>The Wake-On-Lan policy to set for the device. The supported values are:</para>
+ <variablelist>
+ <varlistentry>
+ <term><literal>phy</literal></term>
+ <listitem>
+ <para>Wake on PHY activity.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>magic</literal></term>
+ <listitem>
+ <para>Wake on receipt of magic packet.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>off</literal></term>
+ <listitem>
+ <para>Never wake.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
<refsect1>
<title>See Also</title>
<para><citerefentry>
~ianmdlvl / elogind.git / blobdiff