systemd/man/sd_bus_set_address.xml
2020-04-12 17:24:01 +02:00

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<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="sd_bus_set_address"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_bus_set_address</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_bus_set_address</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_bus_set_address</refname>
<refname>sd_bus_get_address</refname>
<refname>sd_bus_set_exec</refname>
<refpurpose>Set or query the address of the bus connection</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_bus_set_address</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>address</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_get_address</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char **<parameter>address</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_set_exec</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>char *const *<parameter>argv</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_bus_set_address()</function> configures a list of addresses of bus brokers to try to
connect to from a subsequent
<citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry> call.
The argument is a <literal>;</literal>-separated list of addresses to try. Each item must be one of the
following:
</para>
<itemizedlist>
<listitem>
<para>A unix socket address specified as
<literal>unix:guid=<replaceable>guid</replaceable>,path=<replaceable>path</replaceable></literal> or
<literal>unix:guid=<replaceable>guid</replaceable>,abstract=<replaceable>path</replaceable></literal>.
Exactly one of the <varname>path=</varname> and <varname>abstract=</varname> keys must be present,
while <varname>guid=</varname> is optional.</para>
</listitem>
<listitem>
<para>A TCP socket address specified as
<literal>tcp:[guid=<replaceable>guid</replaceable>,][host=<replaceable>host</replaceable>][,port=<replaceable>port</replaceable>][,family=<replaceable>family</replaceable>]</literal>.
One or both of the <varname>host=</varname> and <varname>port=</varname> keys must be present, while
the rest is optional. <replaceable>family</replaceable> may be either <option>ipv4</option> or
<option>ipv6</option>.</para>
</listitem>
<listitem>
<para>An executable to spawn specified as
<literal>unixexec:guid=<replaceable>guid</replaceable>,path=<replaceable>path</replaceable>,argv1=<replaceable>argument</replaceable>,argv2=<replaceable>argument</replaceable>,...</literal>.
The <varname>path=</varname> key must be present, while <varname>guid=</varname> is optional.</para>
</listitem>
<listitem>
<para>A machine (container) to connect to specified as
<literal>x-machine-unix:guid=<replaceable>guid</replaceable>,machine=<replaceable>machine</replaceable>,pid=<replaceable>pid</replaceable></literal>.
Exactly one of the <varname>machine=</varname> and <varname>pid=</varname> keys must be present,
while <varname>guid=</varname> is optional. <parameter>machine</parameter> is the name of a local
container. See
<citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
more information about the "machine" concept. <literal>machine=.host</literal> may be used to specify
the host machine. A connection to the standard system bus socket inside of the specified machine will
be created.</para>
</listitem>
</itemizedlist>
<para>In all cases, parameter <parameter>guid</parameter> is an identifier of the remote peer, in the
syntax accepted by
<citerefentry><refentrytitle>sd_id128_from_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
If specified, the identifier returned by the peer after the connection is established will be checked and
the connection will be rejected in case of a mismatch.</para>
<para>Note that the addresses passed to <function>sd_bus_set_address()</function> may not be verified
immediately. If they are invalid, an error may be returned e.g. from a subsequent call to
<citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
<para><function>sd_bus_get_address()</function> returns any previously set addresses. In addition to
being explicitly set by <function>sd_bus_set_address()</function>, the address will also be set
automatically by
<citerefentry><refentrytitle>sd_bus_open</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
similar calls, based on environment variables or built-in defaults.</para>
<para><function>sd_bus_set_exec</function> is a shorthand function for setting a
<literal>unixexec</literal> address that spawns the given executable with the given arguments.
If <parameter>argv</parameter> is <constant>NULL</constant>, the given executable is spawned
without any extra arguments.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, these functions return a non-negative integer. On failure, they return a negative
errno-style error code.</para>
<refsect2>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-EINVAL</constant></term>
<listitem><para>The input parameters <parameter>bus</parameter> or <parameter>address</parameter> are <constant>NULL</constant>.
</para></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENOPKG</constant></term>
<listitem><para>The bus object <parameter>bus</parameter> could not be resolved.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>-EPERM</constant></term>
<listitem><para>The input parameter <parameter>bus</parameter> is in a wrong state
(<function>sd_bus_set_address()</function> may only be called once on a newly-created bus object).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>-ECHILD</constant></term>
<listitem><para>The bus object <parameter>bus</parameter> was created in a different
process.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENODATA</constant></term>
<listitem><para>The bus object <parameter>bus</parameter> has no address configured.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<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_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>