summaryrefslogtreecommitdiff
path: root/man/sd_pid_get_session.xml
blob: 050f701da3ee0c40400a72ec878889d5149d5ac4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
<?xml version='1.0'?> <!--*-nxml-*-->
<!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_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>
                <refpurpose>Determine session, service, owner of a
                session, container/VM or slice of a specific
                PID or socket peer</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <funcsynopsis>
                        <funcsynopsisinfo>#include &lt;systemd/sd-login.h&gt;</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_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>
                </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. 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) 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. (More specifically: this call will
                not work for processes that are part of user units,
                use <function>sd_pid_get_user_unit()</function> for
                that.) 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) 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 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, where
                <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.</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.</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>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> and
                <function>sd_peer_get_slice()</function> calls operate
                similar to their PID counterparts, but operate on a
                connected AF_UNIX socket and retrieve information
                about the connected peer process.</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>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_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> and
                <function>sd_peer_get_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>