<?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_creds_get_pid" conditional="ENABLE_KDBUS"> <refentryinfo> <title>sd_bus_creds_get_pid</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_creds_get_pid</refentrytitle> <manvolnum>3</manvolnum> </refmeta> <refnamediv> <refname>sd_bus_creds_get_pid</refname> <refname>sd_bus_creds_get_tid</refname> <refname>sd_bus_creds_get_uid</refname> <refname>sd_bus_creds_get_gid</refname> <refname>sd_bus_creds_get_comm</refname> <refname>sd_bus_creds_get_tid_comm</refname> <refname>sd_bus_creds_get_exe</refname> <refname>sd_bus_creds_get_cmdline</refname> <refname>sd_bus_creds_get_cgroup</refname> <refname>sd_bus_creds_get_unit</refname> <refname>sd_bus_creds_get_user_unit</refname> <refname>sd_bus_creds_get_slice</refname> <refname>sd_bus_creds_get_session</refname> <refname>sd_bus_creds_get_owner_uid</refname> <refname>sd_bus_creds_has_effective_cap</refname> <refname>sd_bus_creds_has_permitted_cap</refname> <refname>sd_bus_creds_has_inheritable_cap</refname> <refname>sd_bus_creds_has_bounding_cap</refname> <refname>sd_bus_creds_get_selinux_context</refname> <refname>sd_bus_creds_get_audit_session_id</refname> <refname>sd_bus_creds_get_audit_login_uid</refname> <refname>sd_bus_creds_get_unique_name</refname> <refname>sd_bus_creds_get_well_known_names</refname> <refname>sd_bus_creds_get_connection_name</refname> <refpurpose>Retrieve fields from a credentials object</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>pid_t *<parameter>pid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_tid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>pid_t *<parameter>tid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>uid_t *<parameter>uid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_gid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>gid_t *<parameter>gid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_comm</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>comm</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_tid_comm</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>comm</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_exe</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>exe</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_cmdline</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>char ***<parameter>cmdline</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_cgroup</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>cgroup</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_unit</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>unit</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_user_unit</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>unit</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_slice</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>slice</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_session</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>slice</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_owner_uid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>uid_t *<parameter>uid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_has_effective_cap</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>int <parameter>capability</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_has_permitted_cap</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>int <parameter>capability</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_has_inheritable_cap</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>int <parameter>capability</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_has_bounding_cap</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>int <parameter>capability</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_selinux_context</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>context</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_audit_session_id</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>uint32_t *<parameter>sessionid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_audit_login_uid</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>uid_t *<parameter>loginuid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_unique_name</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>name</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_well_known_names</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>char ***<parameter>name</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_bus_creds_get_connection_name</function></funcdef> <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef> <paramdef>const char **<parameter>name</parameter></paramdef> </funcprototype> </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para>These functions return information from an <parameter>sd_bus_creds</parameter> object. It may be created with <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>, in which case it will describe the specified process, or it may be created by <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>, in which case it will describe the process at the other endpoint of a connection. </para> <para><function>sd_bus_creds_get_pid()</function> will retrieve the PID (process identifier).</para> <para><function>sd_bus_creds_get_tid()</function> will retrieve the TID (thread identifier).</para> <para><function>sd_bus_creds_get_uid()</function> will retrieve the numeric UID (user identifier).</para> <para><function>sd_bus_creds_get_gid()</function> will retrieve the numeric GID (group identifier).</para> <para><function>sd_bus_creds_get_comm()</function> will retrieve the comm field (truncated name of the executable, as stored in <filename>/proc/<replaceable>pid</replaceable>/comm</filename>). </para> <para><function>sd_bus_creds_get_tid_comm()</function> will retrieve the comm field of the thread (as stored in <filename>/proc/<replaceable>pid</replaceable>/task/<replaceable>tid</replaceable>/comm</filename>). </para> <para><function>sd_bus_creds_get_exe()</function> will retrieve the path to the program (as stored in the <filename>/proc/<replaceable>pid</replaceable>/exe</filename> link, but with <literal> (deleted)</literal> suffix removed). </para> <para><function>sd_bus_creds_get_cmdline()</function> will retrieve an array of command line arguments (as stored in <filename>/proc/<replaceable>pid</replaceable>/cmdline</filename>). </para> <para><function>sd_bus_creds_get_cgroup()</function> will retrieve the cgroup path. See <ulink url="https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>. </para> <para><function>sd_bus_creds_get_unit()</function> will retrieve the systemd unit name (in the system instance of systemd) that the process is part of. See <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. </para> <para><function>sd_bus_creds_get_user_unit()</function> will retrieve the systemd unit name (in the user instance of systemd) that the process is part of. See <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. </para> <para><function>sd_bus_creds_get_slice()</function> will retrieve the systemd slice (a unit in the system instance of systemd) that the process is part of. See <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>. </para> <para><function>sd_bus_creds_get_session()</function> will retrieve the logind session that the process is part of. See <citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. </para> <para><function>sd_bus_creds_get_owner_uid()</function> will retrieve the numeric UID (user identifier) of the user who owns the slice that the process is part of. See <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry> <!-- and <citerefentry><refentrytitle>systemd-user-sessions.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> -->. </para> <para><function>sd_bus_creds_has_effective_cap()</function> will check whether the capability specified by <parameter>capability</parameter> was set in the effective capabilities mask. A positive return value means that is was set, zero means that it was not set, and a negative return value signifies an error. See <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> and <varname>Capabilities=</varname> and <varname>CapabilityBoundingSet=</varname> settings in <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. </para> <para><function>sd_bus_creds_has_permitted_cap()</function> is similar to <function>sd_bus_creds_has_effective_cap()</function>, but will check the permitted capabilities mask.</para> <para><function>sd_bus_creds_has_inheritable_cap()</function> is similar to <function>sd_bus_creds_has_effective_cap()</function>, but will check the inheritable capabilities mask.</para> <para><function>sd_bus_creds_has_bounding_cap()</function> is similar to <function>sd_bus_creds_has_effective_cap()</function>, but will check the bounding capabilities mask.</para> <para><function>sd_bus_creds_get_selinux_context()</function> will retrieve the SELinux security context (label) of the process.</para> <para><function>sd_bus_creds_get_audit_session_id()</function> will retrieve the audit session identifier of the process.</para> <para><function>sd_bus_creds_get_audit_login_uid()</function> will retrieve the audit user login identifier (the identifier of the user who is "responsible" for the session).</para> <para><function>sd_bus_creds_get_unique_name()</function> will retrieve the D-Bus unique name. See <ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The D-Bus specification</ulink>.</para> <para><function>sd_bus_creds_get_well_known_names()</function> will retrieve the set of D-Bus well-known names. See <ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The D-Bus specification</ulink>.</para> <para><function>sd_bus_creds_get_connection_name()</function> will retrieve a descriptive name of the bus connection of the peer. This name is useful to discern multiple bus connections by the same peer, and may be altered by the peer with the <citerefentry><refentrytitle>sd_bus_set_name()</refentrytitle><manvolnum>3</manvolnum></citerefentry> call.</para> <para>All functions that take a <parameter>const char**</parameter> parameter will store the answer there as an address of a NUL-terminated string. It will be valid as long as <parameter>c</parameter> remains valid, and should not be freed or modified by the caller.</para> <para>All functions that take a <parameter>char***</parameter> parameter will store the answer there as an address of a an array of strings. Each invidividual string is NUL-terminated, and the array is NULL-terminated as a whole. It will be valid as long as <parameter>c</parameter> remains valid, and should not be freed or modified by the caller.</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>Errors</title> <para>Returned errors may indicate the following problems:</para> <variablelist> <varlistentry> <term><constant>-ENODATA</constant></term> <listitem><para>Given field is not available in <parameter>c</parameter>.</para> </listitem> </varlistentry> <varlistentry> <term><constant>-ENOENT</constant></term> <listitem><para>Given field is not specified for the sender. This will be returned by <function>sd_bus_get_unit()</function>, <function>sd_bus_get_user_unit()</function>, <function>sd_bus_get_slice()</function>, <function>sd_bus_get_session()</function>, and <function>sd_bus_get_name_creds_uid()</function> if the sender is not part of a systemd system unit, systemd user unit, systemd slice, logind session, or a systemd user session.</para> </listitem> </varlistentry> <varlistentry> <term><constant>-ENXIO</constant></term> <listitem><para>An error occurred in parsing cgroup paths. <filename>libsystemd</filename> might be out of sync with the running systemd version.</para></listitem> </varlistentry> <varlistentry> <term><constant>-EINVAL</constant></term> <listitem><para>Specified pointer parameter is <constant>NULL</constant>. </para></listitem> </varlistentry> <varlistentry> <term><constant>-ENOMEM</constant></term> <listitem><para>Memory allocation failed.</para></listitem> </varlistentry> </variablelist> </refsect1> <refsect1> <title>Notes</title> <para><function>sd_bus_open_user()</function> and 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>fork</refentrytitle><manvolnum>2</manvolnum></citerefentry>, <citerefentry><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>credentials</refentrytitle><manvolnum>7</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.journald-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry> </para> </refsect1> </refentry>