mirror of
https://github.com/systemd/systemd.git
synced 2024-11-05 15:21:37 +03:00
fc89f88e56
This also updates the suggested PAM snippet in a number of way:
1. Be closer to the logic nowadays implemented in Fedora where the
auth/account/password stacks are all finished off with
pam_{deny|permit}.so
2. Make pam_unix.so just "sufficient" instead of "required" (paving
ground for pam_systemd_home.so being hooked in as additional
sufficient module.
3. Only do pam_nologin in the "account" stack, since it's about account
validity really.
4. Use modern parameters to pam_unix when changing passwords, i.e.
sha512 and shadow, and use already set up passwords (preparing ground
for pam_systemd_home again)
345 lines
16 KiB
XML
345 lines
16 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
|
|
|
|
<refentry id="pam_systemd" conditional='HAVE_PAM'>
|
|
|
|
<refentryinfo>
|
|
<title>pam_systemd</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>pam_systemd</refentrytitle>
|
|
<manvolnum>8</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>pam_systemd</refname>
|
|
<refpurpose>Register user sessions in the systemd login manager</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<para><filename>pam_systemd.so</filename></para>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><command>pam_systemd</command> registers user sessions with
|
|
the systemd login manager
|
|
<citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
and hence the systemd control group hierarchy.</para>
|
|
|
|
<para>The module also applies various resource management and runtime parameters to the new session, as
|
|
configured in the <ulink url="https://systemd.io/USER_RECORD">JSON User Record</ulink> of the user, when
|
|
one is defined.</para>
|
|
|
|
<para>On login, this module — in conjunction with <filename>systemd-logind.service</filename> — ensures the
|
|
following:</para>
|
|
|
|
<orderedlist>
|
|
<listitem><para>If it does not exist yet, the user runtime directory <filename>/run/user/$UID</filename> is
|
|
either created or mounted as new <literal>tmpfs</literal> file system with quota applied, and its ownership
|
|
changed to the user that is logging in.</para></listitem>
|
|
|
|
<listitem><para>The <varname>$XDG_SESSION_ID</varname> environment variable is initialized. If auditing is
|
|
available and <command>pam_loginuid.so</command> was 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 systemd scope unit is created for the session. If this is the first concurrent session of
|
|
the user, an implicit per-user slice unit below <filename>user.slice</filename> is automatically created and the
|
|
scope placed into it. An instance of the system service <filename>user@.service</filename>, which runs the
|
|
systemd user manager instance, is started.</para></listitem>
|
|
|
|
<listitem><para>The <literal>$TZ</literal>, <literal>$EMAIL</literal> and <literal>$LANG</literal>
|
|
environment variables are configured for the user, based on the respective data from the user's JSON
|
|
record (if it is defined). Moreover, any environment variables explicitly configured in the user record
|
|
are imported, and the umask, nice level, and resource limits initialized.</para></listitem>
|
|
</orderedlist>
|
|
|
|
<para>On logout, this module ensures the following:</para>
|
|
|
|
<orderedlist>
|
|
<listitem><para>If enabled in
|
|
<citerefentry><refentrytitle>logind.conf</refentrytitle>
|
|
<manvolnum>5</manvolnum></citerefentry> (<varname>KillUserProcesses=</varname>), all processes of the session are
|
|
terminated. If the last concurrent session of a user ends, the user's systemd instance will be terminated too,
|
|
and so will the user's slice unit.</para></listitem>
|
|
|
|
<listitem><para>If the last concurrent session of a user ends,
|
|
the user runtime directory <filename>/run/user/$UID</filename> 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
|
|
<constant>PAM_SUCCESS</constant>.</para>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Options</title>
|
|
|
|
<para>The following options are understood:</para>
|
|
|
|
<variablelist class='pam-directives'>
|
|
|
|
<varlistentry>
|
|
<term><varname>class=</varname></term>
|
|
|
|
<listitem><para>Takes a string argument which sets the session class. The <varname>XDG_SESSION_CLASS</varname>
|
|
environment variable (see below) takes precedence. One of <literal>user</literal>, <literal>greeter</literal>,
|
|
<literal>lock-screen</literal> or <literal>background</literal>. See
|
|
<citerefentry><refentrytitle>sd_session_get_class</refentrytitle><manvolnum>3</manvolnum></citerefentry> for
|
|
details about the session class.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>type=</varname></term>
|
|
|
|
<listitem><para>Takes a string argument which sets the session type. The <varname>XDG_SESSION_TYPE</varname>
|
|
environment variable (see below) takes precedence. One of <literal>unspecified</literal>,
|
|
<literal>tty</literal>, <literal>x11</literal>, <literal>wayland</literal> or <literal>mir</literal>. See
|
|
<citerefentry><refentrytitle>sd_session_get_type</refentrytitle><manvolnum>3</manvolnum></citerefentry> for
|
|
details about the session type.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>desktop=</varname></term>
|
|
|
|
<listitem><para>Takes a single, short identifier string for the desktop environment. The
|
|
<varname>XDG_SESSION_DESKTOP</varname> environment variable (see below) takes precedence. This may be used to
|
|
indicate the session desktop used, where this applies and if this information is available. For example:
|
|
<literal>GNOME</literal>, or <literal>KDE</literal>. It is recommended to use the same identifiers and
|
|
capitalization as for <varname>$XDG_CURRENT_DESKTOP</varname>, as defined by the <ulink
|
|
url="http://standards.freedesktop.org/desktop-entry-spec/latest/">Desktop Entry
|
|
Specification</ulink>. (However, note that the option only takes a single item, and not a colon-separated list
|
|
like <varname>$XDG_CURRENT_DESKTOP</varname>.) See
|
|
<citerefentry><refentrytitle>sd_session_get_desktop</refentrytitle><manvolnum>3</manvolnum></citerefentry> for
|
|
further details.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>debug</varname><optional>=</optional></term>
|
|
|
|
<listitem><para>Takes an optional boolean argument. If yes or without the argument, the module will log
|
|
debugging information as it operates.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</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 initialized by the module and available to the processes of the
|
|
user's session:</para>
|
|
|
|
<variablelist class='environment-variables'>
|
|
<varlistentry>
|
|
<term><varname>$XDG_SESSION_ID</varname></term>
|
|
|
|
<listitem><para>A short session identifier, suitable to be used in filenames. The string itself should be
|
|
considered opaque, although often it is just the audit session ID as reported by
|
|
<filename>/proc/self/sessionid</filename>. Each ID will be assigned only once during machine uptime. It may
|
|
hence be used to uniquely label files or other resources of this session. Combine this ID with the boot
|
|
identifier, as returned by
|
|
<citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>, for a
|
|
globally unique identifier for the current session.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$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 the user's final logout. If a user logs in twice at
|
|
the same time, both sessions will see the same
|
|
<varname>$XDG_RUNTIME_DIR</varname> and the same contents. If
|
|
a user logs in once, then logs out again, and logs in again,
|
|
the directory contents will have been lost in between, but
|
|
applications should not rely on this behavior and must be able
|
|
to deal with stale files. To store session-private data in
|
|
this directory, the user should include the value of
|
|
<varname>$XDG_SESSION_ID</varname> in the filename. This
|
|
directory shall be used for runtime file system objects such
|
|
as <constant>AF_UNIX</constant> 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. For further details, see the <ulink
|
|
url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
|
|
Base Directory Specification</ulink>. <varname>$XDG_RUNTIME_DIR</varname>
|
|
is not set if the current user is not the original user of the session.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$TZ</varname></term>
|
|
<term><varname>$EMAIL</varname></term>
|
|
<term><varname>$LANG</varname></term>
|
|
|
|
<listitem><para>If a JSON user record is known for the user logging in these variables are
|
|
initialized from the respective data in the record.</para></listitem>
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
|
|
|
<para>The following environment variables are read by the module and may be used by the PAM service to pass
|
|
metadata to the module. If these variables are not set when the PAM module is invoked but can be determined
|
|
otherwise they are set by the module, so that these variables are initialized for the session and applications if
|
|
known at all.</para>
|
|
|
|
<variablelist class='environment-variables'>
|
|
<varlistentry>
|
|
<term><varname>$XDG_SESSION_TYPE</varname></term>
|
|
|
|
<listitem><para>The session type. This may be used instead of <varname>type=</varname> on the module parameter
|
|
line, and is usually preferred.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$XDG_SESSION_CLASS</varname></term>
|
|
|
|
<listitem><para>The session class. This may be used instead of <varname>class=</varname> on the module parameter
|
|
line, and is usually preferred.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$XDG_SESSION_DESKTOP</varname></term>
|
|
|
|
<listitem><para>The desktop identifier. This may be used instead of <varname>desktop=</varname> on the module
|
|
parameter line, and is usually preferred.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$XDG_SEAT</varname></term>
|
|
|
|
<listitem><para>The seat name the session shall be registered
|
|
for, if any.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>$XDG_VTNR</varname></term>
|
|
|
|
<listitem><para>The VT number the session shall be registered
|
|
for, if any. (Only applies to seats with a VT available, such
|
|
as <literal>seat0</literal>)</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>If not set, <command>pam_systemd</command> will initialize
|
|
<varname>$XDG_SEAT</varname> and <varname>$XDG_VTNR</varname>
|
|
based on the <varname>$DISPLAY</varname> variable (if the latter is set).</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Session limits</title>
|
|
|
|
<para>PAM modules earlier in the stack, that is those that come before <command>pam_systemd.so</command>,
|
|
can set session scope limits using the PAM context objects. The data for these objects is provided as NUL-terminated C strings
|
|
and maps directly to the respective unit resource control directives. Note that these limits apply to individual sessions of the user,
|
|
they do not apply to all user processes as a combined whole. In particular, the per-user <command>user@.service</command> unit instance,
|
|
which runs the <command>systemd --user</command> manager process and its children, and is tracked outside of any session, being shared
|
|
by all the user's sessions, is not covered by these limits.
|
|
</para>
|
|
|
|
<para> See
|
|
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information about the resources.
|
|
Also, see <citerefentry><refentrytitle>pam_set_data</refentrytitle><manvolnum>3</manvolnum></citerefentry> for additional information about how to set
|
|
the context objects.
|
|
</para>
|
|
|
|
<variablelist class='pam-directives'>
|
|
<varlistentry>
|
|
<term><varname>systemd.memory_max</varname></term>
|
|
|
|
<listitem><para>Sets unit <varname>MemoryMax=</varname>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>systemd.tasks_max</varname></term>
|
|
|
|
<listitem><para>Sets unit <varname>TasksMax=</varname>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>systemd.cpu_weight</varname></term>
|
|
|
|
<listitem><para>Sets unit <varname>CPUWeight=</varname>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>systemd.io_weight</varname></term>
|
|
|
|
<listitem><para>Sets unit <varname>IOWeight=</varname>.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>systemd.runtime_max_sec</varname></term>
|
|
|
|
<listitem><para>Sets unit <varname>RuntimeMaxSec=</varname>.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>Example data as can be provided from an another PAM module:
|
|
<programlisting>
|
|
pam_set_data(handle, "systemd.memory_max", (void *)"200M", cleanup);
|
|
pam_set_data(handle, "systemd.tasks_max", (void *)"50", cleanup);
|
|
pam_set_data(handle, "systemd.cpu_weight", (void *)"100", cleanup);
|
|
pam_set_data(handle, "systemd.io_weight", (void *)"340", cleanup);
|
|
pam_set_data(handle, "systemd.runtime_max_sec", (void *)"3600", cleanup);
|
|
</programlisting>
|
|
</para>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Example</title>
|
|
|
|
<para>Here's an example PAM configuration fragment that allows users sessions to be managed by
|
|
<filename>systemd-logind.service</filename>:</para>
|
|
|
|
<programlisting>#%PAM-1.0
|
|
auth sufficient pam_unix.so
|
|
auth required pam_deny.so
|
|
|
|
account required pam_nologin.so
|
|
account sufficient pam_unix.so
|
|
account required pam_permit.so
|
|
|
|
password sufficient pam_unix.so sha512 shadow try_first_pass try_authtok
|
|
password required pam_deny.so
|
|
|
|
-session optional pam_loginuid.so
|
|
-session optional pam_systemd.so
|
|
session required pam_unix.so</programlisting>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>pam_systemd_home</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>pam_loginuid</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|