rfkill: rework and make it listen on /dev/rfkill

With this rework we introduce systemd-rfkill.service as singleton that
is activated via systemd-rfkill.socket that listens on /dev/rfkill. That
way, we get notified each time a new rfkill device shows up or changes
state, in which case we restore and save its current setting to disk.

This is nicer than the previous logic, as this means we save/restore
state even of rfkill devices that are around only intermittently, and
save/restore the state even if the system is shutdown abruptly instead
of cleanly.

This implements what I suggested in #1019 and obsoletes it.

1 files changed, 90 insertions, 0 deletions

diff --git a/man/systemd-rfkill.service.xml b/man/systemd-rfkill.service.xml
new file mode 100644
index 0000000000..f464842700
--- /dev/null
+++ b/man/systemd-rfkill.service.xml
@@ -0,0 +1,90 @@
+<?xml version="1.0"?>
+<!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  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.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+<refentry id="systemd-rfkill.service" conditional='ENABLE_RFKILL'>
+
+  <refentryinfo>
+    <title>systemd-rfkill.service</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>Developer</contrib>
+        <firstname>Lennart</firstname>
+        <surname>Poettering</surname>
+        <email>lennart@poettering.net</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>systemd-rfkill.service</refentrytitle>
+    <manvolnum>8</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>systemd-rfkill.service</refname>
+    <refname>systemd-rfkill.socket</refname>
+    <refname>systemd-rfkill</refname>
+    <refpurpose>Load and save the RF kill switch state at boot and change</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <para><filename>systemd-rfkill.service</filename></para>
+    <para><filename>systemd-rfkill.socket</filename></para>
+    <para><filename>/usr/lib/systemd/systemd-rfkill</filename></para>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><filename>systemd-rfkill.service</filename> is a service
+    that restores the RF kill switch state at early boot and saves it
+    on each change. On disk, the RF kill switch state is stored in
+    <filename>/var/lib/systemd/rfkill/</filename>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Kernel Command Line</title>
+
+    <para><filename>systemd-rfkill</filename> understands the
+    following kernel command line parameter:</para>
+
+    <variablelist class='kernel-commandline-options'>
+      <varlistentry>
+        <term><varname>systemd.restore_state=</varname></term>
+
+        <listitem><para>Takes a boolean argument. Defaults to
+        <literal>1</literal>. If <literal>0</literal>, does not
+        restore the rfkill settings on boot. However, settings will
+        still be stored on shutdown. </para></listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>