For similar reasons as the recent addition of a limit on sessions.
Note that we don't enforce a limit on inhibitors per-user currently, but
there's an implicit one, since each inhibitor takes up one fd, and fds are
limited via RLIMIT_NOFILE, and the limit on the number of processes per user.
We really should put limits on all resources we manage, hence add one to the
number of concurrent sessions, too. This was previously unbounded, hence set a
relatively high limit of 8K by default.
Note that most PAM setups will actually invoke pam_systemd prefixed with "-",
so that the return code of pam_systemd is ignored, and the login attempt
succeeds anyway. On systems like this the session will be created but is not
tracked by systemd.
This new setting configures the TasksMax= field for the slice objects we
create for each user.
This alters logind to create the slice unit as transient unit explicitly
instead of relying on implicit generation of slice units by simply
starting them. This also enables us to set a friendly description for
slice units that way.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Allow passing a "dry-" prefix to the action parameter passed to
.ScheduleShutdown(). When strings with this prefix are passed,
the scheduled action will not take place. Instead, an info message
is logged.
Let logind use the sd_bus_track helper object to track the controllers of
sessions. This does not only remove quite some code but also kills the
unconditional matches for all NameOwnerChanged signals.
The latter is something we should never ever do, as it wakes up the daemon
every time a client connects, which doesn't scale.
Commit c0f32805 ("logind: use sd_event timer source for inhibitor
logic") reworked the main loop logic of logind so that it uses a
real timeout callback handler to execute delayed functions.
What the old code did, however, was to call those functions on
every iteration in the main loop, not only when the timeout
expired.
Restore that behavior by bringing back manager_dispatch_delayed(),
and call it from manager_run(). The internal event source callback
manager_inhibit_timeout_handler() was turned into a wrapper of
manager_dispatch_delayed() now.
Previously, we'd just count connected displays, and if there was 2 or
more we assumed a "docked" state.
With this change we now:
- Only count external displays, ignore internal ones (which we detect by
checking the connector name against a whitelist of known external plug
types)
- We ignore connectors which are explicitly disabled
- We then compare the count with >= 1 rather than >= 2 as before
This new logic has the benefit that systems that disconnect the internal
display when the lid is closed are better supported. Also, explicitly
disabled ports do not confuse the algorithm anymore.
This new algorithm has been suggested here:
http://lists.freedesktop.org/archives/intel-gfx/2015-June/068821.html
This also makes two functions static, that are not used outside of their
.c files.
This should simplify the prototype a bit. The bus parameter is redundant
in most cases, and in the few where it matters it can be derived from
the message via sd_bus_message_get_bus().
Port over more code from shutdownd and teach logind to write /run/nologin at
least 5 minutes before the system is going down, and
/run/systemd/shutdown/scheduled when a shutdown is scheduled.
Add a timer to print UTMP wall messages so that it repeatedly informs users
about a scheduled shutdown:
* every 1 minute with less than 10 minutes to go
* every 15 minutes with less than 60 minutes to go
* every 30 minutes with less than 180 minutes (3 hours) to go
* every 60 minutes if more than that to go
This functionality only active if the .EnableWallMessages DBus property
is set to true. Also, a custom string can be added to the wall message,
set through the WallMessagePrefix property.
Add a method called ScheduleShutdown in org.freedesktop.login1.Manager
which adds a timer to shut down the system at a later point in time.
The first argument holds the type of the schedule that is about to
happen, and must be one of 'reboot', 'halt' or 'poweroff'.
The second argument specifies the absolute time, based on
CLOCK_REALTIME in nanoseconds, at which the the operation should be
executed.
To cancel a previously scheduled shutdown, the CancelScheduledShutdown()
can be called, which returns a bool, indicating whether a scheduled
timeout was cancelled.
Also add a new property called ScheduledShutdown which returns the
equivalent to what was passed in via ScheduleShutdown, as '(st)' type.
Instead of open-coding the delayed action and inhibit timeout logic,
switch over to a real sd_event_source based implementation.
This is not only easier to read but also allows us to add more timers
in the future.
This introduces 'HoldoffTimeoutSec' to logind.conf to make
IGNORE_LID_SWITCH_{SUSPEND,STARTUP}_USEC configurable.
Background: If an external monitor is connected, or if the system is
docked, we want to ignore LID events. This is required to support setups
where a laptop is used with external peripherals while the LID is closed.
However, this requires us to probe all hot-plugged devices before reacting
to LID events. But with modern buses like USB, the standards do not impose
any timeout on the slots, so we have no chance to know whether a given
slot is used or not. Hence, after resume and startup, we have to wait a
fixed timeout to give the kernel a chance to probe devices. Our timeout
has always been generous enough to support even the slowest devices.
However, a lot of people didn't use these features and wanted to disable
the hold-off timer. Now we provide a knob to do that.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
More specifically, if an operation is requested on a session with an
empty name, the caller's session is used. If an operation is requested
on a seat with an empty name, the seat of the caller's session is used.
Finally, if an operation on the user with UID -1 is requested, the user
of the client's session is used (and not the UID of the client!).
This way each user allocates from his own pool, with its own size limit.
This puts the size limit by default to 10% of the physical RAM size but
makes it configurable in logind.conf.
This is needed to give USB docking stations and suchlike time to settle,
so that a display connected to an USB docking station can actually act
as a lid swith inhibitor correctly.
With this change we should have somewhat reliable docking station
support in place.
Previously we expected the desktop environment to take an inhibitor
lock, but this opened a race on boot-up where logind might already be
running but no DE is active.
Hence, let's move checking for additional displays into logind. This
also opens up this logic for other DEs, given that only GNOME
implemented the inhibitor logic so far.
Simplify the shutdown logic a bit:
- Keep the session FIFO around in the PAM module, even after the session
shutdown hook has been finished. This allows logind to track precisely
when the PAM handler goes away.
- In the ReleaseSession() call start a timer, that will stop terminate
the session when elapsed.
- Never fiddle with the KillMode of scopes to configure whether user
processes should be killed or not. Instead, simply leave the scope
units around when we terminate a session whose processes should not be
killed.
- When killing is enabled, stop the session scope on FIFO EOF or after
the ReleaseSession() timeout. When killing is disabled, simply tell
PID 1 to abandon the scope.
Because the scopes stay around and hence all processes are always member
of a scope, the system shutdown logic should be more robust, as the
scopes can be shutdown as part of the usual shutdown logic.
Fix the whole code to use "unsigned int" for vtnr. 0 is an invalid vtnr so
we don't need negative numbers at all.
Note that most code already assumes it's unsigned so in case there's a
negative vtnr, our code may, under special circumstances, silently break.
So this patch makes sure all sources of vtnrs verify the validity. Also
note that the dbus api already uses unsigned ints.
Message handler callbacks can be simplified drastically if the
dispatcher automatically replies to method calls if errors are returned.
Thus: add an sd_bus_error argument to all message handlers. When we
dispatch a message handler and it returns negative or a set sd_bus_error
we send this as message error back to the client. This means errors
returned by handlers by default are given back to clients instead of
rippling all the way up to the event loop, which is desirable to make
things robust.
As a side-effect we can now easily turn the SELinux checks into normal
function calls, since the method call dispatcher will generate the right
error replies automatically now.
Also, make sure we always pass the error structure to all property and
method handlers as last argument to follow the usual style of passing
variables for return values as last argument.
The seat->vtconsole member always points to the default seat seat0. Even
if VTs are disabled, it's used as default seat. Therefore, rename it to
seat0 to correctly state what it is.
This also changes the seat files in /run from IS_VTCONSOLE to IS_SEAT0. It
wasn't used by any code, yet, so this seems fine.
While we are at it, we also remove every "if (s->vtconsole)" as this
pointer is always valid!
If we want to track bus-names to allow exclusive resource-access, we need
a way to get notified when a bus-name is gone. We make logind watch for
NameOwnerChanged dbus events and check whether the name is currently
watched. If it is, we remove it from the watch-list (notification for
other objects can be added in follow-up patches).
Session compositors need access to fbdev, DRM and evdev devices if they
control a session. To make logind pass them to sessions, we need to
listen for them actively.
However, we avoid creating new seats for non master-of-seat devices. Only
once a seat is created, we start remembering all other session devices. If
the last master-device is removed (even if there are other non-master
devices still available), we destroy the seat. This is the current
behavior, but we need to explicitly implement it now as there may be
non-master devices in the seat->devices list.
Unlike master devices, we don't care whether our list of non-master
devices is complete. We don't export this list but use it only as cache if
sessions request these devices. Hence, if a session requests a device that
is not in the list, we will simply look it up. However, once a session
requested a device, we must be notified of "remove" udev events. So we
must link the devices somehow into the device-list.
Regarding the implementation, we now sort the device list by the "master"
flag. This guarantees that master devices are at the front and non-master
devices at the tail of the list. Thus, we can easily test whether a seat
has a master device attached.
As we want to centralized cgroup access we should stop killing the user
sessions directly from the systemd-user-sessions service. Instead, rely
on PID 1 doing this by adding the right ordering dependencies to the
session scope units.
Embedded folks don't need the machine registration stuff, hence it's
nice to make this optional. Also, I'd expect that machinectl will grow
additional commands quickly, for example to join existing containers and
suchlike, hence it's better keeping that separate from loginctl.
In order to prepare things for the single-writer cgroup scheme, let's
make logind use systemd's own primitives for cgroup management.
Every login user now gets his own private slice unit, in which his sessions
live in a scope unit each. Also, add user@$UID.service to the same
slice, and implicitly start it on first login.
- This changes all logind cgroup objects to use slice objects rather
than fixed croup locations.
- logind can now collect minimal information about running
VMs/containers. As fixed cgroup locations can no longer be used we
need an entity that keeps track of machine cgroups in whatever slice
they might be located. Since logind already keeps track of users,
sessions and seats this is a trivial addition.
- nspawn will now register with logind and pass various bits of metadata
along. A new option "--slice=" has been added to place the container
in a specific slice.
- loginctl gained commands to list, introspect and terminate machines.
- user.slice and machine.slice will now be pulled in by logind.service,
since only logind.service requires this slice.
- Don't allow any locks to be taken while we are in the process of
executing the specific operation, so that apps are not surprised if a
suspend/shutdown happens while they rely on their inhibitor.
- Get rid of the Resumed signal, it was a bad idea, and redundant due to
PrepareForSleep(false), see below.
- Always send out PrepareFor{Shutdown,Sleep} signals, instead of only if
a delay lock is taken.
- Move PrepareForSleep(false) after we come back from the suspend, so
that apps can use this as "Resumed" notification. This also has the
benefit that apps know when to take a new lock.
This allows clients to get asynchronous notifications for user-requested
suspend/hibernate cycles. Kernel-triggered automatic suspending is not
covered.
Previously, if X allocated all 6 TTYs (for multi-session for example) no
getty would be available anymore to guarantee console-based logins.
With the new ReserveVT= switch in logind.conf we can now choose one VT
(6 by default) that will always be subject to autovt-style activation,
i.e. we'll always have a getty on TTY6, and X will never take possession
of it.
#pragma once has been "un-deprecated" in gcc since 3.3, and is widely supported
in other compilers.
I've been using and maintaining (rebasing) this patch for a while now, as
it annoyed me to see #ifndef fooblahfoo, etc all over the place,
almost arrogant about the annoyance of having to define all these names to
perform a commen but neccicary functionality, when a completely superior
alternative exists.
I havn't sent it till now, cause its kindof a style change, and it is bad
voodoo to mess with style that has been established by more established
editors. So feel free to lambast me as a crazy bafoon.
v2 - preserve externally used headers
This takes handling of chassis power and sleep keys as well as the lid
switch over from acpid.
This logic is enabled by default for power and sleep keys, but not for
the lid switch.
If a graphical session is in the foreground no action is taken under the
assumption that the graphical session does this.
Lennart Poettering