org.freedesktop.login1(5) — Linux manual page


ORG.FREEDESKTOP.LOGIN1(5)  org.freedesktop.login1  ORG.FREEDESKTOP.LOGIN1(5)

NAME         top

       org.freedesktop.login1 - The D-Bus interface of systemd-logind

INTRODUCTION         top

       systemd-logind.service(8) is a system service that keeps track of
       user logins and seats.

       The daemon provides both a C library interface as well as a D-Bus
       interface. The library interface may be used to introspect and watch
       the state of user logins and seats. The bus interface provides the
       same functionality but in addition may also be used to make changes
       to the system state. For more information please consult sd-login(3).


       The service exposes the following interfaces on the Manager object on
       the bus:

           node /org/freedesktop/login1 {
             interface org.freedesktop.login1.Manager {
                 GetSession(in  s session_id,
                            out o object_path);
                 GetSessionByPID(in  u pid,
                                 out o object_path);
                 GetUser(in  u uid,
                         out o object_path);
                 GetUserByPID(in  u pid,
                              out o object_path);
                 GetSeat(in  s seat_id,
                         out o object_path);
                 ListSessions(out a(susso) sessions);
                 ListUsers(out a(uso) users);
                 ListSeats(out a(so) seats);
                 ListInhibitors(out a(ssssuu) inhibitors);
                 CreateSession(in  u uid,
                               in  u pid,
                               in  s service,
                               in  s type,
                               in  s class,
                               in  s desktop,
                               in  s seat_id,
                               in  u vtnr,
                               in  s tty,
                               in  s display,
                               in  b remote,
                               in  s remote_user,
                               in  s remote_host,
                               in  a(sv) properties,
                               out s session_id,
                               out o object_path,
                               out s runtime_path,
                               out h fifo_fd,
                               out u uid,
                               out s seat_id,
                               out u vtnr,
                               out b existing);
                 ReleaseSession(in  s session_id);
                 ActivateSession(in  s session_id);
                 ActivateSessionOnSeat(in  s session_id,
                                       in  s seat_id);
                 LockSession(in  s session_id);
                 UnlockSession(in  s session_id);
                 KillSession(in  s session_id,
                             in  s who,
                             in  i signal_number);
                 KillUser(in  u uid,
                          in  i signal_number);
                 TerminateSession(in  s session_id);
                 TerminateUser(in  u uid);
                 TerminateSeat(in  s seat_id);
                 SetUserLinger(in  u uid,
                               in  b enable,
                               in  b interactive);
                 AttachDevice(in  s seat_id,
                              in  s sysfs_path,
                              in  b interactive);
                 FlushDevices(in  b interactive);
                 PowerOff(in  b interactive);
                 Reboot(in  b interactive);
                 Halt(in  b interactive);
                 Suspend(in  b interactive);
                 Hibernate(in  b interactive);
                 HybridSleep(in  b interactive);
                 SuspendThenHibernate(in  b interactive);
                 CanPowerOff(out s result);
                 CanReboot(out s result);
                 CanHalt(out s result);
                 CanSuspend(out s result);
                 CanHibernate(out s result);
                 CanHybridSleep(out s result);
                 CanSuspendThenHibernate(out s result);
                 ScheduleShutdown(in  s type,
                                  in  t usec);
                 CancelScheduledShutdown(out b cancelled);
                 Inhibit(in  s what,
                         in  s who,
                         in  s why,
                         in  s mode,
                         out h pipe_fd);
                 CanRebootParameter(out s result);
                 SetRebootParameter(in  s parameter);
                 CanRebootToFirmwareSetup(out s result);
                 SetRebootToFirmwareSetup(in  b enable);
                 CanRebootToBootLoaderMenu(out s result);
                 SetRebootToBootLoaderMenu(in  t timeout);
                 CanRebootToBootLoaderEntry(out s result);
                 SetRebootToBootLoaderEntry(in  s boot_loader_entry);
                 SetWallMessage(in  s wall_message,
                                in  b enable);
                 SessionNew(s session_id,
                            o object_path);
                 SessionRemoved(s session_id,
                                o object_path);
                 UserNew(u uid,
                         o object_path);
                 UserRemoved(u uid,
                             o object_path);
                 SeatNew(s seat_id,
                         o object_path);
                 SeatRemoved(s seat_id,
                             o object_path);
                 PrepareForShutdown(b start);
                 PrepareForSleep(b start);
                 readwrite b EnableWallMessages = ...;
                 readwrite s WallMessage = '...';
                 readonly u NAutoVTs = ...;
                 readonly as KillOnlyUsers = ['...', ...];
                 readonly as KillExcludeUsers = ['...', ...];
                 readonly b KillUserProcesses = ...;
                 readonly s RebootParameter = '...';
                 readonly b RebootToFirmwareSetup = ...;
                 readonly t RebootToBootLoaderMenu = ...;
                 readonly s RebootToBootLoaderEntry = '...';
                 readonly as BootLoaderEntries = ['...', ...];
                 readonly b IdleHint = ...;
                 readonly t IdleSinceHint = ...;
                 readonly t IdleSinceHintMonotonic = ...;
                 readonly s BlockInhibited = '...';
                 readonly s DelayInhibited = '...';
                 readonly t InhibitDelayMaxUSec = ...;
                 readonly t UserStopDelayUSec = ...;
                 readonly s HandlePowerKey = '...';
                 readonly s HandleSuspendKey = '...';
                 readonly s HandleHibernateKey = '...';
                 readonly s HandleLidSwitch = '...';
                 readonly s HandleLidSwitchExternalPower = '...';
                 readonly s HandleLidSwitchDocked = '...';
                 readonly t HoldoffTimeoutUSec = ...;
                 readonly s IdleAction = '...';
                 readonly t IdleActionUSec = ...;
                 readonly b PreparingForShutdown = ...;
                 readonly b PreparingForSleep = ...;
                 readonly (st) ScheduledShutdown = ...;
                 readonly b Docked = ...;
                 readonly b LidClosed = ...;
                 readonly b OnExternalPower = ...;
                 readonly b RemoveIPC = ...;
                 readonly t RuntimeDirectorySize = ...;
                 readonly t RuntimeDirectoryInodesMax = ...;
                 readonly t InhibitorsMax = ...;
                 readonly t NCurrentInhibitors = ...;
                 readonly t SessionsMax = ...;
                 readonly t NCurrentSessions = ...;
             interface org.freedesktop.DBus.Peer { ... };
             interface org.freedesktop.DBus.Introspectable { ... };
             interface org.freedesktop.DBus.Properties { ... };

       GetSession() may be used to get the session object path for the
       session with the specified ID. Similarly, GetUser() and GetSeat() get
       the user and seat objects, respectively.  GetSessionByPID() and
       GetUserByPID() get the session/user object the specified PID belongs
       to if there is any.

       ListSessions() returns an array of all current sessions. The
       structures in the array consist of the following fields: session id,
       user id, user name, seat id, session object path. If a session does
       not have a seat attached, the seat id field will be an empty string.

       ListUsers() returns an array of all currently logged in users. The
       structures in the array consist of the following fields: user id,
       user name, user object path.

       ListSeats() returns an array of all currently available seats. The
       structure in the array consists of the following fields: seat id,
       seat object path.

       ListInhibitors() lists all currently active inhibitors. It returns an
       array of structures consisting of what, who, why, mode, uid (user
       ID), and pid (process ID).

       CreateSession() and ReleaseSession() may be used to open or close
       login sessions. These calls should never be invoked directly by
       clients. Creating/closing sessions is exclusively the job of PAM and
       its pam_systemd(8) module.

       ActivateSession() brings the session with the specified ID into the
       foreground.  ActivateSessionOnSeat() does the same, but only if the
       seat id matches.

       LockSession() asks the session with the specified ID to activate the
       screen lock.  UnlockSession() asks the session with the specified ID
       to remove an active screen lock, if there is any. This is implemented
       by sending out the Lock() and Unlock() signals from the respective
       session object which session managers are supposed to listen on.

       LockSessions() asks all sessions to activate their screen locks. This
       may be used to lock access to the entire machine in one action.
       Similarly, UnlockSessions() asks all sessions to deactivate their
       screen locks.

       KillSession() may be used to send a Unix signal to one or all
       processes of a session. As arguments it takes the session id, either
       the string "leader" or "all" and a signal number. If "leader" is
       passed only the session "leader" is killed. If "all" is passed all
       processes of the session are killed.

       KillUser() may be used to send a Unix signal to all processes of a
       user. As arguments it takes the user id and a signal number.

       TerminateSession(), TerminateUser(), TerminateSeat() may be used to
       forcibly terminate one specific session, all processes of a user, and
       all sessions attached to a specific seat, respectively. The session,
       user, and seat are identified by their respective IDs.

       SetUserLinger() enables or disables user lingering. If enabled, the
       runtime directory of a user is kept around and they may continue to
       run processes while logged out. If disabled, the runtime directory
       goes away as soon as they log out.  SetUserLinger() expects three
       arguments: the UID, a boolean whether to enable/disable and a boolean
       controlling the polkit[1] authorization interactivity (see below).
       Note that the user linger state is persistently stored on disk.

       AttachDevice() may be used to assign a specific device to a specific
       seat. The device is identified by its /sys path and must be eligible
       for seat assignments.  AttachDevice() takes three arguments: the seat
       id, the sysfs path, and a boolean for controlling polkit
       interactivity (see below). Device assignments are persistently stored
       on disk. To create a new seat, simply specify a previously unused
       seat id. For more information about the seat assignment logic see
       Multi-Seat for Linux[2].

       FlushDevices() removes all explicit seat assignments for devices,
       resetting all assignments to the automatic defaults. The only
       argument it takes is the polkit interactivity boolean (see below).

       PowerOff(), Reboot(), Halt(), Suspend(), and Hibernate() result in
       the system being powered off, rebooted, halted (shut down without
       turning off power), suspended (the system state is saved to RAM and
       the CPU is turned off), or hibernated (the system state is saved to
       disk and the machine is powered down).  HybridSleep() results in the
       system entering a hybrid-sleep mode, i.e. the system is both
       hibernated and suspended.  SuspendThenHibernate() results in the
       system being suspended, then later woken using an RTC timer and
       hibernated. The only argument is the polkit interactivity boolean
       interactive (see below). The main purpose of these calls is that they
       enforce polkit policy and hence allow powering
       off/rebooting/suspending/hibernating even by unprivileged users. They
       also enforce inhibition locks. UIs should expose these calls as the
       primary mechanism to poweroff/reboot/suspend/hibernate the machine.

       SetRebootParameter() sets a parameter for a subsequent reboot
       operation. See the description of reboot in systemctl(1) and
       reboot(2) for more information.

       SetRebootToFirmwareSetup(), SetRebootToBootLoaderMenu(), and
       SetRebootToBootLoaderEntry() configure the action to be taken from
       the boot loader after a reboot: respectively entering firmware setup
       mode, the boot loader menu, or a specific boot loader entry. See
       systemctl(1) for the corresponding command line interface.

       CanPowerOff(), CanReboot(), CanHalt(), CanSuspend(), CanHibernate(),
       CanHybridSleep(), CanSuspendThenHibernate(), CanRebootParameter(),
       CanRebootToFirmwareSetup(), CanRebootToBootLoaderMenu(), and
       CanRebootToBootLoaderEntry() test whether the system supports the
       respective operation and whether the calling user is allowed to
       execute it. Returns one of "na", "yes", "no", and "challenge". If
       "na" is returned, the operation is not available because hardware,
       kernel, or drivers do not support it. If "yes" is returned, the
       operation is supported and the user may execute the operation without
       further authentication. If "no" is returned, the operation is
       available but the user is not allowed to execute the operation. If
       "challenge" is returned, the operation is available but only after

       ScheduleShutdown() schedules a shutdown operation type at time usec
       in microseconds since the UNIX epoch.  type can be one of "poweroff",
       "dry-poweroff", "reboot", "dry-reboot", "halt", and "dry-halt". (The
       "dry-" variants do not actually execute the shutdown action.)
       CancelScheduledShutdown() cancels a scheduled shutdown. The output
       parameter cancelled is true if a shutdown operation was scheduled.

       SetWallMessage() sets the wall message (the message that will be sent
       out to all terminals and stored in a utmp(5) record) for a subsequent
       scheduled shutdown operation. The parameter wall_message specifies
       the shutdown reason (and may be empty) which will be included in the
       shutdown message. The parameter enable specifies whether to print a
       wall message on shutdown.

       Inhibit() creates an inhibition lock. It takes four parameters: what,
       who, why, and mode.  what is one or more of "shutdown", "sleep",
       "idle", "handle-power-key", "handle-suspend-key",
       "handle-hibernate-key", "handle-lid-switch", separated by colons, for
       inhibiting poweroff/reboot, suspend/hibernate, the automatic idle
       logic, or hardware key handling.  who should be a short human
       readable string identifying the application taking the lock.  why
       should be a short human readable string identifying the reason why
       the lock is taken. Finally, mode is either "block" or "delay" which
       encodes whether the inhibit shall be consider mandatory or whether it
       should just delay the operation to a certain maximum time. The method
       returns a file descriptor. The lock is released the moment this file
       descriptor and all its duplicates are closed. For more information on
       the inhibition logic see Inhibitor Locks[3].

       Whenever the inhibition state or idle hint changes, PropertyChanged
       signals are sent out to which clients can subscribe.

       The SessionNew, SessionRemoved, UserNew, UserRemoved, SeatNew, and
       SeatRemoved signals are sent each time a session is created or
       removed, a user logs in or out, or a seat is added or removed. They
       each contain the ID of the object plus the object path.

       The PrepareForShutdown() and PrepareForSleep() signals are sent right
       before (with the argument "true") or after (with the argument
       "false") the system goes down for reboot/poweroff and
       suspend/hibernate, respectively. This may be used by applications to
       save data on disk, release memory, or do other jobs that should be
       done shortly before shutdown/sleep, in conjunction with delay
       inhibitor locks. After completion of this work they should release
       their inhibition locks in order to not delay the operation any
       further. For more information see Inhibitor Locks[3].

       Most properties simply reflect the configuration, see logind.conf(5).
       This includes: NAutoVTs, KillOnlyUsers, KillExcludeUsers,
       KillUserProcesses, IdleAction, InhibitDelayMaxUSec, InhibitorsMax,
       UserStopDelayUSec, HandlePowerKey, HandleSuspendKey,
       HandleHibernateKey, HandleLidSwitch, HandleLidSwitchExternalPower,
       HandleLidSwitchDocked, IdleActionUSec, HoldoffTimeoutUSec, RemoveIPC,
       RuntimeDirectorySize, RuntimeDirectoryInodesMax, InhibitorsMax, and

       The IdleHint property reflects the idle hint state of the system. If
       the system is idle it might get into automatic suspend or shutdown
       depending on the configuration.

       IdleSinceHint and IdleSinceHintMonotonic encode the timestamps of the
       last change of the idle hint boolean, in CLOCK_REALTIME and
       CLOCK_MONOTONIC timestamps, respectively, in microseconds since the

       The BlockInhibited and DelayInhibited properties encode the currently
       active locks of the respective modes. They are colon separated lists
       of "shutdown", "sleep", and "idle" (see above).

       NCurrentSessions and NCurrentInhibitors contain the number of
       currently registered sessions and inhibitors.

       The BootLoaderEntries property contains a list of boot loader
       entries. This includes boot loader entries defined in configuration
       and any additional loader entries reported by the boot loader. See
       systemd-boot(7) for more information.

       The PreparingForShutdown and PreparingForSleep boolean properties are
       true during the interval between the two PrepareForShutdown and
       PrepareForSleep signals respectively. Note that these properties do
       not send out PropertyChanged signals.

       The RebootParameter property shows the value set with the
       SetRebootParameter() method described above.

       ScheduledShutdown shows the value pair set with the
       ScheduleShutdown() method described above.

       RebootToFirmwareSetup, RebootToBootLoaderMenu, and
       RebootToBootLoaderEntry are true when the resprective post-reboot
       operation was selected with SetRebootToFirmwareSetup,
       SetRebootToBootLoaderMenu, or SetRebootToBootLoaderEntry.

       The WallMessage and EnableWallMessages properties reflect the
       shutdown reason and wall message enablement switch which can be set
       with the SetWallMessage() method described above.

       Docked is true if the machine is connected to a dock.  LidClosed is
       true when the lid (of a laptop) is closed.  OnExternalPower is true
       when the machine is connected to an external power supply.

       A number of operations are protected via the polkit privilege system.
       SetUserLinger() requires the org.freedesktop.login1.set-user-linger
       privilege.  AttachDevice() requires
       org.freedesktop.login1.attach-device and FlushDevices() requires
       org.freedesktop.login1.flush-devices.  PowerOff(), Reboot(), Halt(),
       Suspend(), Hibernate() require org.freedesktop.login1.power-off,
       org.freedesktop.login1.hibernate-ignore-inhibit, respectively
       depending on whether there are other sessions around or active
       inhibits are present.  HybridSleep() and SuspendThenHibernate() use
       the same privileges as Hibernate().  SetRebootParameter() requires

       SetRebootToFirmwareSetup requires
       SetRebootToBootLoaderMenu requires
       SetRebootToBootLoaderEntry requires

       ScheduleShutdown and CancelScheduledShutdown require the same
       privileges (listed above) as the immediate poweroff/reboot/halt

       Inhibit() is protected via one of
       org.freedesktop.login1.inhibit-handle-lid-switch depending on the
       lock type and mode taken.

       The interactive boolean parameters can be used to control whether
       polkit should interactively ask the user for authentication
       credentials if required.

SEAT OBJECTS         top

           node /org/freedesktop/login1/seat/seat0 {
             interface org.freedesktop.login1.Seat {
                 ActivateSession(in  s session_id);
                 SwitchTo(in  u vtnr);
                 readonly s Id = '...';
                 readonly (so) ActiveSession = ...;
                 readonly b CanTTY = ...;
                 readonly b CanGraphical = ...;
                 readonly a(so) Sessions = [...];
                 readonly b IdleHint = ...;
                 readonly t IdleSinceHint = ...;
                 readonly t IdleSinceHintMonotonic = ...;
             interface org.freedesktop.DBus.Peer { ... };
             interface org.freedesktop.DBus.Introspectable { ... };
             interface org.freedesktop.DBus.Properties { ... };

       Terminate() and ActivateSession() work similar to TerminateSeat(),
       ActivationSessionOnSeat() on the Manager object.

       SwitchTo() switches to the session on the virtual terminal vtnr.
       SwitchToNext() and SwitchToPrevious() switch to, respectively, the
       next and previous sessions on the seat in the order of virtual
       terminals. If there is no active session, they switch to,
       respectively, the first and last session on the seat.

       Whenever ActiveSession, Sessions, CanGraphical, CanTTY, or the idle
       state changes, PropertyChanged signals are sent out to which clients
       can subscribe.

       The Id property encodes the ID of the seat.

       ActiveSession encodes the currently active session if there is one.
       It is a structure consisting of the session id and the object path.

       CanTTY encodes whether the session is suitable for text logins, and
       CanGraphical whether it is suitable for graphical sessions.

       The Sessions property is an array of all current sessions of this
       seat, each encoded in a structure consisting of the ID and the object

       The IdleHint, IdleSinceHint, and IdleSinceHintMonotonic properties
       encode the idle state, similar to the ones exposed on the Manager
       object, but specific for this seat.

USER OBJECTS         top

           node /org/freedesktop/login1/user/_1000 {
             interface org.freedesktop.login1.User {
                 Kill(in  i signal_number);
                 readonly u UID = ...;
                 readonly u GID = ...;
                 readonly s Name = '...';
                 readonly t Timestamp = ...;
                 readonly t TimestampMonotonic = ...;
                 readonly s RuntimePath = '...';
                 readonly s Service = '...';
                 readonly s Slice = '...';
                 readonly (so) Display = ...;
                 readonly s State = '...';
                 readonly a(so) Sessions = [...];
                 readonly b IdleHint = ...;
                 readonly t IdleSinceHint = ...;
                 readonly t IdleSinceHintMonotonic = ...;
                 readonly b Linger = ...;
             interface org.freedesktop.DBus.Peer { ... };
             interface org.freedesktop.DBus.Introspectable { ... };
             interface org.freedesktop.DBus.Properties { ... };

       Terminate() and Kill() work similar to the TerminateUser() and
       KillUser() methods on the manager object.

       Whenever Sessions or the idle state changes, PropertyChanged signals
       are sent out to which clients can subscribe.

       The UID and GID properties encode the Unix UID and primary GID of the

       The Name property encodes the user name.

       Timestamp and TimestampMonotonic encode the login time of the user in
       microseconds since the epoch, in the CLOCK_REALTIME and
       CLOCK_MONOTONIC clocks, respectively.

       RuntimePath encodes the runtime path of the user, i.e.
       $XDG_RUNTIME_DIR. For details see the XDG Basedir Specification[4].

       Service contains the unit name of the user systemd service of this
       user. Each logged in user is assigned a user service that runs a user
       systemd instance. This is usually an instance of user@.service.

       Slice contains the unit name of the user systemd slice of this user.
       Each logged in user gets a private slice.

       Display encodes which graphical session should be used as the primary
       UI display for the user. It is a structure encoding the session ID
       and the object path of the session to use.

       State encodes the user state and is one of "offline", "lingering",
       "online", "active", or "closing". See sd_uid_get_state(3) for more
       information about the states.

       Sessions is an array of structures encoding all current sessions of
       the user. Each structure consists of the ID and object path.

       The IdleHint, IdleSinceHint, and IdleSinceHintMonotonic properties
       encode the idle hint state of the user, similar to the Manager's
       properties, but specific for this user.

       The Linger property shows whether lingering is enabled for this user.


           node /org/freedesktop/login1/session/1 {
             interface org.freedesktop.login1.Session {
                 SetIdleHint(in  b idle);
                 SetLockedHint(in  b locked);
                 Kill(in  s who,
                      in  i signal_number);
                 TakeControl(in  b force);
                 SetType(in  s type);
                 TakeDevice(in  u major,
                            in  u minor,
                            out h fd,
                            out b inactive);
                 ReleaseDevice(in  u major,
                               in  u minor);
                 PauseDeviceComplete(in  u major,
                                     in  u minor);
                 SetBrightness(in  s subsystem,
                               in  s name,
                               in  u brightness);
                 PauseDevice(u major,
                             u minor,
                             s type);
                 ResumeDevice(u major,
                              u minor,
                              h fd);
                 readonly s Id = '...';
                 readonly (uo) User = ...;
                 readonly s Name = '...';
                 readonly t Timestamp = ...;
                 readonly t TimestampMonotonic = ...;
                 readonly u VTNr = ...;
                 readonly (so) Seat = ...;
                 readonly s TTY = '...';
                 readonly s Display = '...';
                 readonly b Remote = ...;
                 readonly s RemoteHost = '...';
                 readonly s RemoteUser = '...';
                 readonly s Service = '...';
                 readonly s Desktop = '...';
                 readonly s Scope = '...';
                 readonly u Leader = ...;
                 readonly u Audit = ...;
                 readonly s Type = '...';
                 readonly s Class = '...';
                 readonly b Active = ...;
                 readonly s State = '...';
                 readonly b IdleHint = ...;
                 readonly t IdleSinceHint = ...;
                 readonly t IdleSinceHintMonotonic = ...;
                 readonly b LockedHint = ...;
             interface org.freedesktop.DBus.Peer { ... };
             interface org.freedesktop.DBus.Introspectable { ... };
             interface org.freedesktop.DBus.Properties { ... };

       Terminate(), Activate(), Lock(), Unlock(), and Kill() work similarly
       to the respective calls on the Manager object.

       SetIdleHint() is called by the session object to update the idle
       state of the session whenever it changes.

       TakeControl() allows a process to take exclusive managed device
       access-control for that session. Only one D-Bus connection can be a
       controller for a given session at any time. If the force argument is
       set (root only), an existing controller is kicked out and replaced.
       Otherwise, this method fails if there is already a controller. Note
       that this method is limited to D-Bus users with the effective UID set
       to the user of the session or root.

       ReleaseControl() drops control of a given session. Closing the D-Bus
       connection implicitly releases control as well. See TakeControl() for
       more information. This method also releases all devices for which the
       controller requested ownership via TakeDevice().

       SetType() allows the type of the session to be changed dynamically.
       It can only be called by session's current controller. If
       TakeControl() has not been called, this method will fail. In
       addition, the session type will be reset to its original value once
       control is released, either by calling ReleaseControl() or closing
       the D-Bus connection. This should help prevent a session from
       entering an inconsistent state, for example if the controller
       crashes. The only argument type is the new session type.

       TakeDevice() allows a session controller to get a file descriptor for
       a specific device. Pass in the major and minor numbers of the
       character device and systemd-logind will return a file descriptor for
       the device. Only a limited set of device-types is currently supported
       (but may be extended).  systemd-logind automatically mutes the file
       descriptor if the session is inactive and resumes it once the session
       is activated again. This guarantees that a session can only access
       session devices if the session is active. Note that this
       revoke/resume mechanism is asynchronous and may happen at any given
       time. This only works on devices that are attached to the seat of the
       given session. A process is not required to have direct access to the
       device node.  systemd-logind only requires you to be the active
       session controller (see TakeControl()). Also note that any device can
       only be requested once. As long as you don't release it, further
       TakeDevice() calls will fail.

       ReleaseDevice() releases a device again (see TakeDevice()). This is
       also implicitly done by ReleaseControl() or when closing the D-Bus

       PauseDeviceComplete() allows a session controller to synchronously
       pause a device after receiving a PauseDevice("pause") signal. Forced
       signals (or after an internal timeout) are automatically completed by
       systemd-logind asynchronously.

       SetLockedHint() may be used to set the "locked hint" to locked, i.e.
       information whether the session is locked. This is intended to be
       used by the desktop environment to tell systemd-logind when the
       session is locked and unlocked.

       SetBrightness() may be used to set the display brightness. This is
       intended to be used by the desktop environment and allows
       unprivileged programs to access hardware settings in a controlled
       way. The subsystem parameter specifies a kernel subsystem, either
       "backlight" or "leds". The name parameter specifies a device name
       under the specified subsystem. The brightness parameter specifies the
       brightness. The range is defined by individual drivers, see

       The active session controller exclusively gets PauseDevice and
       ResumeDevice events for any device it requested via TakeDevice().
       They notify the controller whenever a device is paused or resumed. A
       device is never resumed if its session is inactive. Also note that
       PauseDevice signals are sent before the PropertyChanged signal for
       the Active state. The inverse is true for ResumeDevice. A device may
       remain paused for unknown reasons even though the Session is active.

       A PauseDevice signal carries the major and minor numbers and a string
       describing the type as arguments.  force means the device was already
       paused by systemd-logind and the signal is only an asynchronous
       notification.  pause means systemd-logind grants you a limited amount
       of time to pause the device. You must respond to this via
       PauseDeviceComplete(). This synchronous pausing mechanism is used for
       backwards-compatibility to VTs and systemd-logind is free to not make
       use of it. It is also free to send a forced PauseDevice if you don't
       respond in a timely manner (or for any other reason).  gone means the
       device was unplugged from the system and you will no longer get any
       notifications about it. There is no need to call ReleaseDevice(). You
       may call TakeDevice() again if a new device is assigned the
       major+minor combination.

       ResumeDevice is sent whenever a session is active and a device is
       resumed. It carries the major/minor numbers as arguments and provides
       a new open file descriptor. You should switch to the new descriptor
       and close the old one. They are not guaranteed to have the same
       underlying open file descriptor in the kernel (except for a limited
       set of device types).

       Whenever Active or the idle state changes, PropertyChanged signals
       are sent out to which clients can subscribe.

       Lock/Unlock is sent when the session is asked to be
       screen-locked/unlocked. A session manager of the session should
       listen to this signal and act accordingly. This signal is sent out as
       a result of the Lock() and Unlock() methods, respectively.

       Id encodes the session ID.

       User encodes the user ID of the user this session belongs to. This is
       a structure consisting of the Unix UID and the object path.

       Name encodes the user name.

       Timestamp and TimestampMonotonic encode the microseconds since the
       epoch when the session was created, in CLOCK_REALTIME or
       CLOCK_MONOTONIC, respectively.

       VTNr encodes the virtual terminal number of the session if there is
       any, 0 otherwise.

       Seat encodes the seat this session belongs to if there is any. This
       is a structure consisting of the ID and the seat object path.

       TTY encodes the kernel TTY path of the session if this is a text
       login. If not this is an empty string.

       Display encodes the X11 display name if this is a graphical login. If
       not, this is an empty string.

       Remote encodes whether the session is local or remote.

       RemoteHost and RemoteUser encode the remote host and user if this is
       a remote session, or an empty string otherwise.

       Service encodes the PAM service name that registered the session.

       Desktop describes the desktop environment running in the session (if

       Scope contains the systemd scope unit name of this session.

       Leader encodes the PID of the process that registered the session.

       Audit encodes the Kernel Audit session ID of the session if auditing
       is available.

       Type encodes the session type. It's one of "unspecified" (for cron
       PAM sessions and suchlike), "tty" (for text logins) or
       "x11"/"mir"/"wayland" (for graphical logins).

       Class encodes the session class. It's one of "user" (for normal user
       sessions), "greeter" (for display manager pseudo-sessions), or
       "lock-screen" (for display lock screens).

       Active is a boolean that is true if the session is active, i.e.
       currently in the foreground. This field is semi-redundant due to

       State encodes the session state and one of "online", "active", or
       "closing". See sd_session_get_state(3) for more information about the

       IdleHint, IdleSinceHint, and IdleSinceHintMonotonic encapsulate the
       idle hint state of this session, similarly to how the respective
       properties on the manager object do it for the whole system.

       LockedHint shows the locked hint state of this session, as set by the
       SetLockedHint() method described above.

EXAMPLES         top

       Example 1. Introspect org.freedesktop.login1.Manager on the bus

           $ gdbus introspect --system --dest org.freedesktop.login1 \
             --object-path /org/freedesktop/login1

       Example 2. Introspect org.freedesktop.login1.Seat on the bus

           $ gdbus introspect --system --dest org.freedesktop.login1 \
            --object-path /org/freedesktop/login1/seat/seat0

       Example 3. Introspect org.freedesktop.login1.User on the bus

           $ gdbus introspect --system --dest org.freedesktop.login1 \
             --object-path /org/freedesktop/login1/user/_1000

       Example 4. Introspect org.freedesktop.login1.Session on the bus

           $ gdbus introspect --system --dest org.freedesktop.login1 \
             --object-path /org/freedesktop/login1/session/45

VERSIONING         top

       These D-Bus interfaces follow the usual interface versioning

NOTES         top

        1. polkit

        2. Multi-Seat for Linux

        3. Inhibitor Locks

        4. XDG Basedir Specification

        5. the usual interface versioning guidelines

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-09-18.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to

systemd 246                                        ORG.FREEDESKTOP.LOGIN1(5)

Pages that refer to this page: org.freedesktop.systemd1(5)30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)systemd-logind(8)systemd-logind.service(8)