units: introduce systemd-udevd-varlink.socket

Co-authored-by: David Tardon <dtardon@redhat.com>

man/rules/meson.build

@@ -1143,7 +1143,8 @@ manpages = [
   '8',
   ['systemd-udevd',
    'systemd-udevd-control.socket',
-   'systemd-udevd-kernel.socket'],
+   'systemd-udevd-kernel.socket',
+   'systemd-udevd-varlink.socket'],
   ''],
  ['systemd-update-done.service', '8', ['systemd-update-done'], ''],
  ['systemd-update-utmp.service',

man/systemd-udevd.service.xml

@@ -20,6 +20,7 @@
     <refname>systemd-udevd.service</refname>
     <refname>systemd-udevd-control.socket</refname>
     <refname>systemd-udevd-kernel.socket</refname>
+    <refname>systemd-udevd-varlink.socket</refname>
     <refname>systemd-udevd</refname>
     <refpurpose>Device event managing daemon</refpurpose>
   </refnamediv>
@@ -28,6 +29,7 @@
     <para><filename>systemd-udevd.service</filename></para>
     <para><filename>systemd-udevd-control.socket</filename></para>
     <para><filename>systemd-udevd-kernel.socket</filename></para>
+    <para><filename>systemd-udevd-varlink.socket</filename></para>
 
     <cmdsynopsis>
       <command>/usr/lib/systemd/systemd-udevd</command>

man/udevadm.xml

@@ -677,7 +677,7 @@
             Note that <filename>systemd-udevd.service</filename> contains
             <option>Restart=always</option> and so as a result, this option restarts systemd-udevd.
             If you want to stop <filename>systemd-udevd.service</filename>, please use the following:
-            <programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service</programlisting>
+            <programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd-varlink.socket systemd-udevd.service</programlisting>
             </para>
           </listitem>
         </varlistentry>

units/initrd-udevadm-cleanup-db.service

@@ -11,8 +11,8 @@
 Description=Cleanup udev Database
 DefaultDependencies=no
 AssertPathExists=/etc/initrd-release
-Conflicts=systemd-udevd.service systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udev-trigger.service systemd-udev-settle.service
-After=systemd-udevd.service systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udev-trigger.service systemd-udev-settle.service
+Conflicts=systemd-udevd.service systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd-varlink.socket systemd-udev-trigger.service systemd-udev-settle.service
+After=systemd-udevd.service systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd-varlink.socket systemd-udev-trigger.service systemd-udev-settle.service
 Before=initrd-switch-root.target
 
 [Service]

units/meson.build

@@ -732,6 +732,10 @@ units = [
           'file' : 'systemd-udevd-kernel.socket',
           'symlinks' : ['sockets.target.wants/'],
         },
+        {
+          'file' : 'systemd-udevd-varlink.socket',
+          'symlinks' : ['sockets.target.wants/'],
+        },
         {
           'file' : 'systemd-udevd.service.in',
           'symlinks' : ['sysinit.target.wants/'],

units/systemd-udev-trigger.service

@@ -12,7 +12,7 @@ Description=Coldplug All udev Devices
 Documentation=man:udev(7) man:systemd-udevd.service(8)
 DefaultDependencies=no
 Wants=systemd-udevd.service
-After=systemd-udevd-kernel.socket systemd-udevd-control.socket
+After=systemd-udevd-kernel.socket systemd-udevd-control.socket systemd-udevd-varlink.socket
 Before=sysinit.target
 ConditionPathIsReadWrite=/sys
 

units/systemd-udevd-varlink.socket

@@ -0,0 +1,22 @@
+#  SPDX-License-Identifier: LGPL-2.1-or-later
+#
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=udev Varlink Socket
+Documentation=man:systemd-udevd-varlink.socket(8) man:udev(7)
+DefaultDependencies=no
+Before=sockets.target
+ConditionPathIsReadWrite=/sys
+
+[Socket]
+Service=systemd-udevd.service
+ListenStream=/run/udev/io.systemd.Udev
+FileDescriptorName=varlink
+SocketMode=0600
+RemoveOnStop=yes

units/systemd-udevd.service.in

@@ -23,7 +23,7 @@ DelegateSubgroup=udev
 Type=notify-reload
 # Note that udev will reset the value internally for its workers
 OOMScoreAdjust=-1000
-Sockets=systemd-udevd-control.socket systemd-udevd-kernel.socket
+Sockets=systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd-varlink.socket
 Restart=always
 RestartSec=0
 ExecStart={{LIBEXECDIR}}/systemd-udevd