pam_systemd — Register user sessions in the systemd login manager
pam_systemd.so
pam_systemd registers user sessions in the systemd login manager systemd-logind.service(8), and hence the systemd control group hierarchy.
On login, this module ensures the following:
If it does not exist yet, the
                        user runtime directory
                        /run/user/$USER is
                        created and its ownership changed to the user
                        that is logging in.
The
                        $XDG_SESSION_ID environment
                        variable is initialized. If auditing is
                        available and
                        pam_loginuid.so run before
                        this module (which is highly recommended), the
                        variable is initialized from the auditing
                        session id
                        (/proc/self/sessionid). Otherwise
                        an independent session counter is
                        used.
A new control group
                        /user/$USER/$XDG_SESSION_ID
                        is created and the login process moved into
                        it.
On logout, this module ensures the following:
If
                        $XDG_SESSION_ID is set and
                        kill-session-processes=1 specified, all
                        remaining processes in the
                        /user/$USER/$XDG_SESSION_ID
                        control group are killed and the control group
                        is removed.
If the last subgroup of the
                        /user/$USER control group
                        was removed the
                        $XDG_RUNTIME_DIR directory
                        and all its contents are
                        removed, too.
If the system was not booted up with systemd as init system, this module does nothing and immediately returns PAM_SUCCESS.
The following options are understood:
kill-session-processes=¶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.
kill-only-users=¶Takes a comma
                                separated list of user names or
                                numeric user ids as argument. If this
                                option is used the effect of the
                                kill-session-processes= options
                                will apply only to the listed
                                users. If this option is not used the
                                option applies to all local
                                users. Note that
                                kill-exclude-users=
                                takes precedence over this list and is
                                hence subtracted from the list
                                specified here.
kill-exclude-users=¶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
                                kill-session-processes=.  Note
                                that this option takes precedence
                                over
                                kill-only-users=, and
                                hence whatever is listed for
                                kill-exclude-users=
                                is guaranteed to never be killed by
                                this PAM module, independent of any
                                other configuration
                                setting.
controllers=¶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.
reset-controllers=¶Takes a comma separated list of control group controllers in which hierarchies the logged in processes will be reset to the root control group.
class=¶Takes a string argument which sets the session class. The XDG_SESSION_CLASS environmental variable takes precedence.
debug=¶Takes a boolean argument. If yes, the module will log debugging information as it operates.
Note that setting
                kill-session-processes=1 will break tools
                like
                screen(1).
Note that
                kill-session-processes=1 is a
                stricter version of
                KillUserProcesses=1 which may be
                configured system-wide in
                logind.conf(5). 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.
If the options are omitted they default to
                kill-session-processes=0,
                kill-only-users=,
                kill-exclude-users=,
                controllers=,
                reset-controllers=,
                debug=no.
The following environment variables are set for the processes of the user's session:
$XDG_SESSION_ID¶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
                                /proc/self/sessionid. 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.
$XDG_RUNTIME_DIR¶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
                                $XDG_RUNTIME_DIR
                                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 $XDG_SESSION_ID
                                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.
#%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