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Diffstat (limited to 'src/libsystemd/sd_pid_get_session.xml')
| -rw-r--r-- | src/libsystemd/sd_pid_get_session.xml | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/libsystemd/sd_pid_get_session.xml b/src/libsystemd/sd_pid_get_session.xml new file mode 100644 index 0000000000..806cff34e4 --- /dev/null +++ b/src/libsystemd/sd_pid_get_session.xml @@ -0,0 +1,359 @@ +<?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 2010 Lennart Poettering + + 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_pid_get_session" conditional='HAVE_PAM'> + + <refentryinfo> + <title>sd_pid_get_session</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_pid_get_session</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_pid_get_session</refname> + <refname>sd_pid_get_unit</refname> + <refname>sd_pid_get_user_unit</refname> + <refname>sd_pid_get_owner_uid</refname> + <refname>sd_pid_get_machine_name</refname> + <refname>sd_pid_get_slice</refname> + <refname>sd_pid_get_user_slice</refname> + <refname>sd_pid_get_cgroup</refname> + <refname>sd_peer_get_session</refname> + <refname>sd_peer_get_unit</refname> + <refname>sd_peer_get_user_unit</refname> + <refname>sd_peer_get_owner_uid</refname> + <refname>sd_peer_get_machine_name</refname> + <refname>sd_peer_get_slice</refname> + <refname>sd_peer_get_user_slice</refname> + <refname>sd_peer_get_cgroup</refname> + <refpurpose>Determine session, unit, owner of a session, + container/VM or slice of a specific PID or socket + peer</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-login.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_pid_get_session</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>session</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_unit</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>unit</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_user_unit</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>unit</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_owner_uid</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>uid_t *<parameter>uid</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_machine_name</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>name</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_slice</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>slice</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_user_slice</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>slice</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_pid_get_cgroup</function></funcdef> + <paramdef>pid_t <parameter>pid</parameter></paramdef> + <paramdef>char **<parameter>cgroup</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_session</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>session</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_unit</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>unit</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_user_unit</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>unit</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_owner_uid</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>uid_t *<parameter>uid</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_machine_name</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>name</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_slice</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>slice</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_user_slice</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>slice</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_peer_get_cgroup</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>char **<parameter>cgroup</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_pid_get_session()</function> may be used to + determine the login session identifier of a process identified by + the specified process identifier. The session identifier is a + short string, suitable for usage in file system paths. Note that + not all processes are part of a login session (e.g. system service + processes, user processes that are shared between multiple + sessions of the same user, or kernel threads). For processes not + being part of a login session, this function will fail with + -ENODATA. The returned string needs to be freed with the libc + <citerefentry + project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> + call after use.</para> + + <para><function>sd_pid_get_unit()</function> may be used to + determine the systemd system unit (i.e. system service or scope + unit) identifier of a process identified by the specified PID. The + unit name is a short string, suitable for usage in file system + paths. Note that not all processes are part of a system + unit/service (e.g. user processes, or kernel threads). For + processes not being part of a systemd system unit, this function + will fail with -ENODATA. (More specifically, this call will not + work for kernel threads.) The returned string needs to be freed + with the libc <citerefentry + project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> + call after use.</para> + + <para><function>sd_pid_get_user_unit()</function> may be used to + determine the systemd user unit (i.e. user service or scope unit) + identifier of a process identified by the specified PID. This is + similar to <function>sd_pid_get_unit()</function>, but applies to + user units instead of system units.</para> + + <para><function>sd_pid_get_owner_uid()</function> may be used to + determine the Unix UID (user identifier) of the owner of the + session of a process identified the specified PID. Note that this + function will succeed for user processes which are shared between + multiple login sessions of the same user, whereas + <function>sd_pid_get_session()</function> will fail. For processes + not being part of a login session and not being a shared process + of a user, this function will fail with -ENODATA.</para> + + <para><function>sd_pid_get_machine_name()</function> may be used + to determine the name of the VM or container is a member of. The + machine name is a short string, suitable for usage in file system + paths. The returned string needs to be freed with the libc + <citerefentry + project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> + call after use. For processes not part of a VM or containers, this + function fails with -ENODATA.</para> + + <para><function>sd_pid_get_slice()</function> may be used to + determine the slice unit the process is a member of. See + <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details about slices. The returned string needs to be freed + with the libc + <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> + call after use.</para> + + <para>Similarly, <function>sd_pid_get_user_slice()</function> + returns the user slice (as managed by the user's systemd instance) + of a process.</para> + + <para><function>sd_pid_get_cgroup()</function> returns the control + group path of the specified process, relative to the root of the + hierarchy. Returns the path without trailing slash, except for + processes located in the root control group, where "/" is + returned. To find the actual control group path in the file system, + the returned path needs to be prefixed with + <filename>/sys/fs/cgroup/</filename> (if the unified control group + setup is used), or + <filename>/sys/fs/cgroup/<replaceable>HIERARCHY</replaceable>/</filename> + (if the legacy multi-hierarchy control group setup is used).</para> + + <para>If the <varname>pid</varname> parameter of any of these + functions is passed as 0, the operation is executed for the + calling process.</para> + + <para>The <function>sd_peer_get_session()</function>, + <function>sd_peer_get_unit()</function>, + <function>sd_peer_get_user_unit()</function>, + <function>sd_peer_get_owner_uid()</function>, + <function>sd_peer_get_machine_name()</function>, + <function>sd_peer_get_slice()</function>, + <function>sd_peer_get_user_slice()</function> and + <function>sd_peer_get_cgroup()</function> calls operate similar to + their PID counterparts, but operate on a connected AF_UNIX socket + and retrieve information about the connected peer process. Note + that these fields are retrieved via <filename>/proc</filename>, + and hence are not suitable for authorization purposes, as they are + subject to races.</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>-ESRCH</constant></term> + + <listitem><para>The specified PID does not refer to a running + process.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><constant>-BADF</constant></term> + + <listitem><para>The specified socket file descriptor was + invalid.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENODATA</constant></term> + + <listitem><para>The given field is not specified for the described + process or peer.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>An input parameter was invalid (out of range, + or NULL, where that is not accepted).</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Memory allocation failed.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para>The <function>sd_pid_get_session()</function>, + <function>sd_pid_get_unit()</function>, + <function>sd_pid_get_user_unit()</function>, + <function>sd_pid_get_owner_uid()</function>, + <function>sd_pid_get_machine_name()</function>, + <function>sd_pid_get_slice()</function>, + <function>sd_pid_get_user_slice()</function>, + <function>sd_peer_get_session()</function>, + <function>sd_peer_get_unit()</function>, + <function>sd_peer_get_user_unit()</function>, + <function>sd_peer_get_owner_uid()</function>, + <function>sd_peer_get_machine_name()</function>, + <function>sd_peer_get_slice()</function> and + <function>sd_peer_get_user_slice()</function> interfaces 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> + + <para>Note that the login session identifier as + returned by <function>sd_pid_get_session()</function> + is completely unrelated to the process session + identifier as returned by + <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_session_is_active</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |