man: update sd_bus_open() documentation

Update for current function prototypes.

Also, document -ESOCKTNOSUPPORT as being returned when protocol version
mismatches are detected.

1 files changed, 263 insertions, 0 deletions

diff --git a/man/sd_bus_default.xml b/man/sd_bus_default.xml
new file mode 100644
index 0000000000..98ec04ecde
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+++ b/man/sd_bus_default.xml
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+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!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 2014 Zbigniew Jędrzejewski-Szmek
+
+  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="sd_bus_default" conditional="ENABLE_KDBUS">
+
+  <refentryinfo>
+    <title>sd_bus_default</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>A monkey with a typewriter</contrib>
+        <firstname>Zbigniew</firstname>
+        <surname>Jędrzejewski-Szmek</surname>
+        <email>zbyszek@in.waw.pl</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_default</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_default</refname>
+    <refname>sd_bus_default_user</refname>
+    <refname>sd_bus_default_system</refname>
+
+    <refname>sd_bus_open</refname>
+    <refname>sd_bus_open_user</refname>
+    <refname>sd_bus_open_system</refname>
+    <refname>sd_bus_open_system_remote</refname>
+    <refname>sd_bus_open_system_machine</refname>
+
+    <refpurpose>Acquire a connection to a system or user bus</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_default</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_default_user</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_default_system</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_open</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_open_user</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_open_system</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_open_system_remote</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+        <paramdef>const char *<parameter>host</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_open_system_machine</function></funcdef>
+        <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
+        <paramdef>const char *<parameter>machine</parameter></paramdef>
+      </funcprototype>
+
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><function>sd_bus_default()</function> acquires a bus
+    connection object to the user bus when invoked in user context or
+    to the system bus otherwise. The connection object is associated
+    to the calling thread. Each time the function is invoked from the
+    same thread the same object is returned, but its reference count
+    increased by one, as long as at least one reference is kept. When
+    the last reference to the connection is dropped (using the
+    <function>sd_bus_unref()</function> call), the connection is
+    terminated. Note that the connection is not automatically
+    terminated when the associated thread ends. It is important to
+    drop the last reference to the bus connection explicitly before
+    the thread ends or otherwise the connection will be leaked.</para>
+
+    <para><function>sd_bus_default_user()</function> returns a user
+    bus connection object associated to the calling thread.
+    <function>sd_bus_default_system()</function> is similar, but
+    connects to the system bus.</para>
+
+    <para><function>sd_bus_open()</function> creates a new,
+    independent bus connection to the user bus when invoked in user
+    context or the system bus
+    otherwise. <function>sd_bus_open_user()</function> is similar, but
+    connects only to the user bus.
+    <function>sd_bus_open_system()</function> does the same, but
+    connects to the system bus. In contrast to
+    <function>sd_bus_default()</function>,
+    <function>sd_bus_default_user()</function>,
+    <function>sd_bus_default_system()</function> these calls return
+    new, independent connection objects that are not associated with
+    the invoking thread and are not shared between multiple
+    invocations. It is recommended to share connections per thread to
+    efficiently make use the available resources. Thus, it is
+    recommended to use <function>sd_bus_default()</function>,
+    <function>sd_bus_default_user()</function>,
+    <function>sd_bus_default_system()</function> to connect to the
+    user or system busses.</para>
+
+    <para>If the <varname>$DBUS_SESSION_BUS_ADDRESS</varname> environment
+    variable is set
+    (cf. <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>),
+    it will be used as the address of the user bus. This variable can
+    contain multiple addresses separated by <literal>;</literal>. If
+    this variable is not set, a suitable default for the default user
+    D-Bus instance will be used.</para>
+
+    <para>If the <varname>$DBUS_SYSTEM_BUS_ADDRESS</varname>
+    environment variable is set, it will be used as the address of the
+    system bus. This variable uses the same syntax as
+    <varname>$DBUS_SESSION_BUS_ADDRESS</varname>. If this variable is
+    not set, a suitable default for the default system D-Bus instance
+    will be used.</para>
+
+    <para><function>sd_bus_open_system_remote()</function> connects to
+    the system bus on the specified <parameter>host</parameter> using
+    SSH. <parameter>host</parameter> consists of an optional user name
+    followed by the <literal>@</literal> symbol, and the hostname.
+    </para>
+
+    <para><function>sd_bus_open_system_container()</function> connects
+    to the system bus in the specified <parameter>machine</parameter>,
+    where <parameter>machine</parameter> is the name of a local
+    container.  See
+    <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    for more information about "machines".</para>
+
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>On success, these calls return 0 or a positive
+    integer. On failure, these calls return a negative
+    errno-style error code.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Reference ownership</title>
+    <para>The functions <function>sd_bus_open_user()</function>,
+    <function>sd_bus_open()</function>,
+    <function>sd_bus_open_system()</function>,
+    <function>sd_bus_open_system_remote()</function>, and
+    <function>sd_bus_open_system_machine()</function> return a new
+    object and the caller owns the sole reference. When not needed
+    anymore, this reference should be destroyed with
+    <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+    </para>
+
+    <para>The functions <function>sd_bus_default()</function>,
+    <function>sd_bus_default_user()</function> and
+    <function>sd_bus_default_system()</function> do not necessarily
+    create a new object, but increase the connection reference by
+    one. Use
+    <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    to drop the reference.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Errors</title>
+
+    <para>Returned errors may indicate the following problems:</para>
+
+    <variablelist>
+
+      <varlistentry>
+        <term><constant>-EINVAL</constant></term>
+
+        <listitem><para>The specified parameters are invalid.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><constant>-ENOMEM</constant></term>
+
+        <listitem><para>Memory allocation failed.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><constant>-ESOCKTNOSUPPORT</constant></term>
+
+        <listitem><para>The protocol version required to connect to the selected bus is not supported.</para></listitem>
+      </varlistentry>
+    </variablelist>
+
+    <para>In addition, any further connection-related errors may be
+    by returned. See <citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Notes</title>
+
+    <para><function>sd_bus_open_user()</function> and the other
+    functions described here are available as a shared library, which
+    can be compiled and linked to with the
+    <constant>libsystemd</constant> <citerefentry
+    project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    file.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry project='die-net'><refentrytitle>ssh</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>