man/sd_bus_query_sender_creds.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="sd_bus_query_sender_creds" xmlns:xi="http://www.w3.org/2001/XInclude">
   7
   8   <refentryinfo>
   9     <title>sd_bus_query_sender_creds</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>sd_bus_query_sender_creds</refentrytitle>
  15     <manvolnum>3</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>sd_bus_query_sender_creds</refname>
  20     <refname>sd_bus_query_sender_privilege</refname>
  21
  22     <refpurpose>Query bus message sender credentials/privileges</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <funcsynopsis>
  27       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  28
  29       <funcprototype>
  30         <funcdef>int <function>sd_bus_query_sender_creds</function></funcdef>
  31         <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
  32         <paramdef>uint64_t <parameter>mask</parameter></paramdef>
  33         <paramdef>sd_bus_creds **<parameter>creds</parameter></paramdef>
  34       </funcprototype>
  35
  36       <funcprototype>
  37         <funcdef>sd_bus_error* <function>sd_bus_query_sender_privilege</function></funcdef>
  38         <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
  39         <paramdef>int <parameter>capability</parameter></paramdef>
  40       </funcprototype>
  41     </funcsynopsis>
  42   </refsynopsisdiv>
  43
  44   <refsect1>
  45     <title>Description</title>
  46
  47     <para><function>sd_bus_query_sender_creds()</function> returns the credentials of the message
  48     <parameter>m</parameter>. The <parameter>mask</parameter> parameter is a combo of
  49     <constant index='false'>SD_BUS_CREDS_*</constant> flags that indicate which credential info the caller is
  50     interested in. See
  51     <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  52     for a list of possible flags. First, this message checks if the requested credentials are attached to the
  53     message itself. If not, but the message contains the pid of the sender and the caller specified the
  54     <constant index='false'>SD_BUS_CREDS_AUGMENT</constant> flag, this function tries to figure out
  55     the missing credentials via other means (starting from the pid). If the pid isn't available but the
  56     message has a sender, this function calls
  57     <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  58     to get the requested credentials. If the message has no sender (when a direct connection is used), this
  59     function calls
  60     <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  61     to get the requested credentials. On success, the requested credentials are stored in
  62     <parameter>creds</parameter>. Ownership of the credentials object in <parameter>creds</parameter> is
  63     transferred to the caller and should be freed by calling
  64     <citerefentry><refentrytitle>sd_bus_creds_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  65     </para>
  66
  67     <para><function>sd_bus_query_sender_privilege()</function> checks if the message <parameter>m</parameter>
  68     has the requested privileges. If <parameter>capability</parameter> is a non-negative integer, this
  69     function checks if the message has the capability with the same value. See
  70     <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  71     for a list of capabilities. If <parameter>capability</parameter> is a negative integer, this function
  72     returns whether the sender of the message runs as the same user as the receiver of the message, or if the
  73     sender of the message runs as root and the receiver of the message does not run as root. On success and
  74     if the message has the requested privileges, this function returns a positive integer. If the message
  75     does not have the requested privileges, this function returns zero.</para>
  76   </refsect1>
  77
  78   <refsect1>
  79     <title>Return Value</title>
  80
  81     <para>On success, these functions return a non-negative integer. On failure, they return a negative
  82     errno-style error code.</para>
  83
  84     <refsect2>
  85       <title>Errors</title>
  86
  87       <para>Returned errors may indicate the following problems:</para>
  88
  89       <variablelist>
  90         <varlistentry>
  91           <term><constant>-EINVAL</constant></term>
  92
  93           <listitem><para>The message <parameter>m</parameter> or an output parameter is
  94           <constant>NULL</constant>.</para>
  95
  96           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
  97         </varlistentry>
  98
  99         <varlistentry>
 100           <term><constant>-ENOTCONN</constant></term>
 101
 102           <listitem><para>The bus of <parameter>m</parameter> is not connected.</para>
 103
 104           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 105         </varlistentry>
 106
 107         <varlistentry>
 108           <term><constant>-ECHILD</constant></term>
 109
 110           <listitem><para>The bus of <parameter>m</parameter> was created in a different process, library or module instance.
 111           </para>
 112
 113           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 114         </varlistentry>
 115
 116         <varlistentry>
 117           <term><constant>-EPERM</constant></term>
 118
 119           <listitem><para>The message <parameter>m</parameter> is not sealed.</para>
 120
 121           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 122         </varlistentry>
 123       </variablelist>
 124     </refsect2>
 125   </refsect1>
 126
 127   <xi:include href="libsystemd-pkgconfig.xml" />
 128
 129   <refsect1>
 130     <title>History</title>
 131     <para><function>sd_bus_query_sender_creds()</function> and
 132     <function>sd_bus_query_sender_privilege()</function> were added in version 246.</para>
 133   </refsect1>
 134
 135   <refsect1>
 136     <title>See Also</title>
 137
 138     <para>
 139       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 140       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 141       <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 142       <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 143       <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 144       <citerefentry><refentrytitle>sd_bus_creds_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 145       <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 146     </para>
 147   </refsect1>
 148 </refentry>