systemd/man/sd_bus_set_address.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<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>