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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
|
<?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="pam_systemd">
<refentryinfo>
<title>pam_systemd</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>pam_systemd</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>pam_systemd</refname>
<refpurpose>Register user sessions in the systemd control group hierarchy</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>pam_systemd.so</command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>pam_systemd</command> registers user
sessions in the systemd control group
hierarchy.</para>
<para>On login, this module ensures the following:</para>
<orderedlist>
<listitem><para>If it does not exist yet, the
user runtime directory
<filename>/run/user/$USER</filename> is
created and its ownership changed to the user
that is logging in.</para></listitem>
<listitem><para>The
<varname>$XDG_SESSION_ID</varname> environment
variable is initialized. If auditing is
available and
<command>pam_loginuid.so</command> run before
this module (which is highly recommended), the
variable is initialized from the auditing
session id
(<filename>/proc/self/sessionid</filename>). Otherwise
an independent session counter is
used.</para></listitem>
<listitem><para>A new control group
<filename>/user/$USER/$XDG_SESSION_ID</filename>
is created and the login process moved into
it.</para></listitem>
</orderedlist>
<para>On logout, this module ensures the following:</para>
<orderedlist>
<listitem><para>If
<varname>$XDG_SESSION_ID</varname> is set and
<option>kill-session-processes=1</option> specified, all
remaining processes in the
<filename>/user/$USER/$XDG_SESSION_ID</filename>
control group are killed and the control group
is removed.</para></listitem>
<listitem><para>If last subgroup of the
<filename>/user/$USER</filename> control group
was removed the
<varname>$XDG_RUNTIME_DIR</varname> directory
and all its contents are
removed, too.</para></listitem>
</orderedlist>
<para>If the system was not booted up with systemd as
init system, this module does nothing and immediately
returns PAM_SUCCESS.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>kill-session-processes=</option></term>
<listitem><para>Takes a boolean
argument. If true, all processes
created by the user during his session
and from his session will be
terminated when he logs out from his
session.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>kill-only-users=</option></term>
<listitem><para>Takes a comma
separated list of user names or
numeric user ids as argument. If this
option is used the effect of the
<option>kill-session-processes=</option> options
will apply only to the listed
users. If this option is not used the
option applies to all local
users. Note that
<option>kill-exclude-users=</option>
takes precedence over this list and is
hence subtracted from the list
specified here.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>kill-exclude-users=</option></term>
<listitem><para>Takes a comma
separated list of user names or
numeric user ids as argument. Users
listed in this argument will not be
subject to the effect of
<option>kill-session-processes=</option>. Note
that that this option takes precedence
over
<option>kill-only-users=</option>, and
hence whatever is listed for
<option>kill-exclude-users=</option>
is guaranteed to never be killed by
this PAM module, independent of any
other configuration
setting.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>controllers=</option></term>
<listitem><para>Takes a comma
separated list of control group
controllers in which hierarchies a
user/session control group will be
created by default for each user
logging in, in addition to the control
group in the named 'name=systemd'
hierarchy. If omitted, defaults to an
empty list.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>reset-controllers=</option></term>
<listitem><para>Takes a comma
separated list of control group
controllers in which hierarchies the
logged in processes will be reset to
the root control
group.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>debug=</option></term>
<listitem><para>Takes a boolean
argument. If yes, the module will log
debugging information as it
operates.</para></listitem>
</varlistentry>
</variablelist>
<para>Note that setting
<varname>kill-session-processes=1</varname> will break tools
like
<citerefentry><refentrytitle>screen</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
<para>Note that
<varname>kill-session-processes=1</varname> is a
stricter version of
<varname>KillUserProcesses=1</varname> which may be
configured system-wide in
<citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
former kills processes of a session as soon as it
ends, the latter kills processes as soon as the last
session of the user ends.</para>
<para>If the options are omitted they default to
<option>kill-session-processes=0</option>,
<option>kill-only-users=</option>,
<option>kill-exclude-users=</option>,
<option>controllers=</option>,
<option>reset-controllers=</option>,
<option>debug=no</option>.</para>
</refsect1>
<refsect1>
<title>Module Types Provided</title>
<para>Only <option>session</option> is provided.</para>
</refsect1>
<refsect1>
<title>Environment</title>
<para>The following environment variables are set for the processes of the user's session:</para>
<variablelist>
<varlistentry>
<term><varname>$XDG_SESSION_ID</varname></term>
<listitem><para>A session identifier,
suitable to be used in file names. The
string itself should be considered
opaque, although often it is just the
audit session ID as reported by
<filename>/proc/self/sessionid</filename>. Each
ID will be assigned only once during
machine uptime. It may hence be used
to uniquely label files or other
resources of this
session.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>$XDG_RUNTIME_DIR</varname></term>
<listitem><para>Path to a user-private
user-writable directory that is bound
to the user login time on the
machine. It is automatically created
the first time a user logs in and
removed on his final logout. If a user
logs in twice at the same time, both
sessions will see the same
<varname>$XDG_RUNTIME_DIR</varname>
and the same contents. If a user logs
in once, then logs out again, and logs
in again, the directory contents will
have been lost in between, but
applications should not rely on this
behaviour and must be able to deal with
stale files. To store session-private
data in this directory the user should
include the value of <varname>$XDG_SESSION_ID</varname>
in the filename. This directory shall
be used for runtime file system
objects such as AF_UNIX sockets,
FIFOs, PID files and similar. It is
guaranteed that this directory is
local and offers the greatest possible
file system feature set the
operating system
provides.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Example</title>
<programlisting>#%PAM-1.0
auth required pam_unix.so
auth required pam_nologin.so
account required pam_unix.so
password required pam_unix.so
session required pam_unix.so
session required pam_loginuid.so
session required pam_systemd.so kill-session-processes=1</programlisting>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pam_loginuid</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
