systemd/man/sd_bus_creds_get_pid.xml
Lennart Poettering 3280236156 sd-bus: get rid of PID starttime concept
As kdbus no longer exports this, remove all traces from sd-bus too
2014-12-09 18:16:54 +01:00

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<?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">
<!--
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Copyright 2014 Zbigniew Jędrzejewski-Szmek
systemd is free software; you can redistribute it and/or modify it
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<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 &lt;systemd/sd-bus.h&gt;</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>