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+ -->
   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, this function tries to figure out
  54     the missing credentials via other means (starting from the pid). If the pid isn't available but the
  55     message has a sender, this function calls
  56     <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  57     to get the requested credentials. If the message has no sender (when a direct connection is used), this
  58     function calls
  59     <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  60     to get the requested credentials. On success, the requested credentials are stored in
  61     <parameter>creds</parameter>. Ownership of the credentials object in <parameter>creds</parameter> is
  62     transferred to the caller and should be freed by calling
  63     <citerefentry><refentrytitle>sd_bus_creds_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  64     </para>
  65
  66     <para><function>sd_bus_query_sender_privilege()</function> checks if the message <parameter>m</parameter>
  67     has the requested privileges. If <parameter>capability</parameter> is a non-negative integer, this
  68     function checks if the message has the capability with the same value. See
  69     <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  70     for a list of capabilities. If <parameter>capability</parameter> is a negative integer, this function
  71     returns whether the sender of the message runs as the same user as the receiver of the message, or if the
  72     sender of the message runs as root and the receiver of the message does not run as root. On success and
  73     if the message has the requested privileges, this function returns a positive integer. If the message
  74     does not have the requested privileges, this function returns zero.</para>
  75   </refsect1>
  76
  77   <refsect1>
  78     <title>Return Value</title>
  79
  80     <para>On success, these functions return a non-negative integer. On failure, they return a negative
  81     errno-style error code.</para>
  82
  83     <refsect2>
  84       <title>Errors</title>
  85
  86       <para>Returned errors may indicate the following problems:</para>
  87
  88       <variablelist>
  89         <varlistentry>
  90           <term><constant>-EINVAL</constant></term>
  91
  92           <listitem><para>The message <parameter>m</parameter> or an output parameter is
  93           <constant>NULL</constant>.</para></listitem>
  94         </varlistentry>
  95
  96         <varlistentry>
  97           <term><constant>-ENOTCONN</constant></term>
  98
  99           <listitem><para>The bus of <parameter>m</parameter> is not connected.</para></listitem>
 100         </varlistentry>
 101
 102         <varlistentry>
 103           <term><constant>-ECHILD</constant></term>
 104
 105           <listitem><para>The bus of <parameter>m</parameter> was created in a different process.
 106           </para></listitem>
 107         </varlistentry>
 108
 109         <varlistentry>
 110           <term><constant>-EPERM</constant></term>
 111
 112           <listitem><para>The message <parameter>m</parameter> is not sealed.</para></listitem>
 113         </varlistentry>
 114       </variablelist>
 115     </refsect2>
 116   </refsect1>
 117
 118   <xi:include href="libsystemd-pkgconfig.xml" />
 119
 120   <refsect1>
 121     <title>See Also</title>
 122
 123     <para>
 124       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 125       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 126       <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 127       <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 128       <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 129       <citerefentry><refentrytitle>sd_bus_creds_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 130       <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 131     </para>
 132   </refsect1>
 133 </refentry>