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