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Systemd/src/login/logind-session-device.c

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logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 David Herrmann
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <fcntl.h>
#include <linux/input.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/types.h>
tree-wide: group include of libudev.h with sd-*
2015-11-17 06:52:45 +01:00
#include "libudev.h"
util-lib: split out allocation calls into alloc-util.[ch]
2015-10-27 03:01:06 +01:00
#include "alloc-util.h"
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
#include "bus-util.h"
util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.
2015-10-25 13:14:12 +01:00
#include "fd-util.h"
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
#include "logind-session-device.h"
util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.
2015-10-25 13:14:12 +01:00
#include "missing.h"
#include "util.h"
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
enum SessionDeviceNotifications {
SESSION_DEVICE_RESUME,
SESSION_DEVICE_TRY_PAUSE,
SESSION_DEVICE_PAUSE,
SESSION_DEVICE_RELEASE,
};
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
static int session_device_notify(SessionDevice *sd, enum SessionDeviceNotifications type) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
_cleanup_free_ char *path = NULL;
const char *t = NULL;
logind: fix session-device dbus notify Had this fix lying around here for some time. Thanks to missing type-checking for va-args we passed in the actual major/minor values instead of pointers to it. Fix it by saving the values on the stack first and passing in the pointers.
2013-10-01 17:48:15 +02:00
uint32_t major, minor;
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
int r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
assert(sd);
logind: fix session-device dbus notify Had this fix lying around here for some time. Thanks to missing type-checking for va-args we passed in the actual major/minor values instead of pointers to it. Fix it by saving the values on the stack first and passing in the pointers.
2013-10-01 17:48:15 +02:00
major = major(sd->dev);
minor = minor(sd->dev);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (!sd->session->controller)
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
return 0;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
path = session_bus_path(sd->session);
if (!path)
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
return -ENOMEM;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
r = sd_bus_message_new_signal(
api: in constructor function calls, always put the returned object pointer first (or second) Previously the returned object of constructor functions where sometimes returned as last, sometimes as first and sometimes as second parameter. Let's clean this up a bit. Here are the new rules: 1. The object the new object is derived from is put first, if there is any 2. The object we are creating will be returned in the next arguments 3. This is followed by any additional arguments Rationale: For functions that operate on an object we always put that object first. Constructors should probably not be too different in this regard. Also, if the additional parameters might want to use varargs which suggests to put them last. Note that this new scheme only applies to constructor functions, not to all other functions. We do give a lot of freedom for those. Note that this commit only changes the order of the new functions we added, for old ones we accept the wrong order and leave it like that.
2014-02-19 23:54:58 +01:00
sd->session->manager->bus,
&m, path,
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
"org.freedesktop.login1.Session",
api: in constructor function calls, always put the returned object pointer first (or second) Previously the returned object of constructor functions where sometimes returned as last, sometimes as first and sometimes as second parameter. Let's clean this up a bit. Here are the new rules: 1. The object the new object is derived from is put first, if there is any 2. The object we are creating will be returned in the next arguments 3. This is followed by any additional arguments Rationale: For functions that operate on an object we always put that object first. Constructors should probably not be too different in this regard. Also, if the additional parameters might want to use varargs which suggests to put them last. Note that this new scheme only applies to constructor functions, not to all other functions. We do give a lot of freedom for those. Note that this commit only changes the order of the new functions we added, for old ones we accept the wrong order and leave it like that.
2014-02-19 23:54:58 +01:00
(type == SESSION_DEVICE_RESUME) ? "ResumeDevice" : "PauseDevice");
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (!m)
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
return r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
r = sd_bus_message_set_destination(m, sd->session->controller);
if (r < 0)
return r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
switch (type) {
case SESSION_DEVICE_RESUME:
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
r = sd_bus_message_append(m, "uuh", major, minor, sd->fd);
if (r < 0)
return r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
break;
case SESSION_DEVICE_TRY_PAUSE:
t = "pause";
break;
case SESSION_DEVICE_PAUSE:
t = "force";
break;
case SESSION_DEVICE_RELEASE:
t = "gone";
break;
default:
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
return -EINVAL;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
}
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
if (t) {
r = sd_bus_message_append(m, "uus", major, minor, t);
if (r < 0)
return r;
}
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
logind: port logind to libsystemd-bus
2013-11-05 01:10:21 +01:00
return sd_bus_send(sd->session->manager->bus, m, NULL);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
}
static int sd_eviocrevoke(int fd) {
static bool warned;
int r;
assert(fd >= 0);
logind: fix sd_eviocrevoke ioctl call If the third argument is non-null, the kernel will always error out with EINVAL and devices won't get revoked. Reported-by: Benjamin Tissoires <benjamin.tissoires@gmail.com> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2015-01-22 02:36:02 +01:00
r = ioctl(fd, EVIOCREVOKE, NULL);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (r < 0) {
r = -errno;
if (r == -EINVAL && !warned) {
warned = true;
log_warning("kernel does not support evdev-revocation");
}
}
return 0;
}
static int sd_drmsetmaster(int fd) {
int r;
assert(fd >= 0);
r = ioctl(fd, DRM_IOCTL_SET_MASTER, 0);
if (r < 0)
return -errno;
return 0;
}
static int sd_drmdropmaster(int fd) {
int r;
assert(fd >= 0);
r = ioctl(fd, DRM_IOCTL_DROP_MASTER, 0);
if (r < 0)
return -errno;
return 0;
}
static int session_device_open(SessionDevice *sd, bool active) {
logind: check whether first drmSetMaster succeeded The initial drmSetMaster may fail if there is an active master already. We must not assume that all existing clients comply to logind rules. We check for this during session-activation already but didn't during device setup. Fix this by checking the return code. As drmSetMaster has had horrible return codes in the past (0 for failure? EINVAL for denied access, ..) we need to be quite pedantic. To guarantee an open file-descriptor we need to close the device and reopen it without master if setting master failed first.
2013-10-01 17:53:43 +02:00
int fd, r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
assert(sd->type != DEVICE_TYPE_UNKNOWN);
/* open device and try to get an udev_device from it */
fd = open(sd->node, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
if (fd < 0)
return -errno;
switch (sd->type) {
case DEVICE_TYPE_DRM:
logind: check whether first drmSetMaster succeeded The initial drmSetMaster may fail if there is an active master already. We must not assume that all existing clients comply to logind rules. We check for this during session-activation already but didn't during device setup. Fix this by checking the return code. As drmSetMaster has had horrible return codes in the past (0 for failure? EINVAL for denied access, ..) we need to be quite pedantic. To guarantee an open file-descriptor we need to close the device and reopen it without master if setting master failed first.
2013-10-01 17:53:43 +02:00
if (active) {
/* Weird legacy DRM semantics might return an error
* even though we're master. No way to detect that so
* fail at all times and let caller retry in inactive
* state. */
r = sd_drmsetmaster(fd);
if (r < 0) {
logind: ignore failing close() on session-devices Unfortunately, close() on a revoked/removed character-device fails with ENODEV. I tried tracking this down in the kernel, but couldn't figure out were exactly it comes from. However, can be easily reproduced with: fd = open("/dev/input/event0", O_RDWR); ioctl(fd, EVIOCREVOKE, 0); r = close(fd); A second close on @fd would return EBADF so the close is actually valid. We simply ignore close() errors for all session-devices as their access may be revoked asynchronously, or the device might get unplugged. We use close_nointr() in case anyone ever looks at the return value (or anyone runs "grep 'close(' -r src/" to find broken close() calls). Fixes: systemd-logind[31992]: Assertion 'close_nointr(fd) == 0' failed at src/shared/util.c:185, function close_nointr_nofail(). Aborting.
2013-11-28 14:51:40 +01:00
close_nointr(fd);
logind: check whether first drmSetMaster succeeded The initial drmSetMaster may fail if there is an active master already. We must not assume that all existing clients comply to logind rules. We check for this during session-activation already but didn't during device setup. Fix this by checking the return code. As drmSetMaster has had horrible return codes in the past (0 for failure? EINVAL for denied access, ..) we need to be quite pedantic. To guarantee an open file-descriptor we need to close the device and reopen it without master if setting master failed first.
2013-10-01 17:53:43 +02:00
return r;
}
} else {
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
/* DRM-Master is granted to the first user who opens a
* device automatically (ughh, racy!). Hence, we just
* drop DRM-Master in case we were the first. */
sd_drmdropmaster(fd);
}
break;
case DEVICE_TYPE_EVDEV:
if (!active)
sd_eviocrevoke(fd);
break;
case DEVICE_TYPE_UNKNOWN:
default:
/* fallback for devices wihout synchronizations */
break;
}
return fd;
}
static int session_device_start(SessionDevice *sd) {
int r;
assert(sd);
assert(session_is_active(sd->session));
if (sd->active)
return 0;
switch (sd->type) {
case DEVICE_TYPE_DRM:
/* Device is kept open. Simply call drmSetMaster() and hope
* there is no-one else. In case it fails, we keep the device
* paused. Maybe at some point we have a drmStealMaster(). */
r = sd_drmsetmaster(sd->fd);
if (r < 0)
return r;
break;
case DEVICE_TYPE_EVDEV:
/* Evdev devices are revoked while inactive. Reopen it and we
* are fine. */
r = session_device_open(sd, true);
if (r < 0)
return r;
logind: ignore failing close() on session-devices Unfortunately, close() on a revoked/removed character-device fails with ENODEV. I tried tracking this down in the kernel, but couldn't figure out were exactly it comes from. However, can be easily reproduced with: fd = open("/dev/input/event0", O_RDWR); ioctl(fd, EVIOCREVOKE, 0); r = close(fd); A second close on @fd would return EBADF so the close is actually valid. We simply ignore close() errors for all session-devices as their access may be revoked asynchronously, or the device might get unplugged. We use close_nointr() in case anyone ever looks at the return value (or anyone runs "grep 'close(' -r src/" to find broken close() calls). Fixes: systemd-logind[31992]: Assertion 'close_nointr(fd) == 0' failed at src/shared/util.c:185, function close_nointr_nofail(). Aborting.
2013-11-28 14:51:40 +01:00
close_nointr(sd->fd);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
sd->fd = r;
break;
case DEVICE_TYPE_UNKNOWN:
default:
/* fallback for devices wihout synchronizations */
break;
}
sd->active = true;
return 0;
}
static void session_device_stop(SessionDevice *sd) {
assert(sd);
if (!sd->active)
return;
switch (sd->type) {
case DEVICE_TYPE_DRM:
/* On DRM devices we simply drop DRM-Master but keep it open.
* This allows the user to keep resources allocated. The
* CAP_SYS_ADMIN restriction to DRM-Master prevents users from
* circumventing this. */
sd_drmdropmaster(sd->fd);
break;
case DEVICE_TYPE_EVDEV:
/* Revoke access on evdev file-descriptors during deactivation.
* This will basically prevent any operations on the fd and
* cannot be undone. Good side is: it needs no CAP_SYS_ADMIN
* protection this way. */
sd_eviocrevoke(sd->fd);
break;
case DEVICE_TYPE_UNKNOWN:
default:
/* fallback for devices without synchronization */
break;
}
sd->active = false;
}
static DeviceType detect_device_type(struct udev_device *dev) {
const char *sysname, *subsystem;
DeviceType type;
sysname = udev_device_get_sysname(dev);
subsystem = udev_device_get_subsystem(dev);
type = DEVICE_TYPE_UNKNOWN;
logind: remove fbdev session-device support fbdev does not support access-handover so it is quite useless to route it through logind. If compositors want to use it they ought to open it themselves. It's highly recommended to be ignored entirely, though. fbdev is about to be deprecated in the kernel.
2013-10-01 18:08:54 +02:00
if (streq_ptr(subsystem, "drm")) {
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (startswith(sysname, "card"))
type = DEVICE_TYPE_DRM;
} else if (streq_ptr(subsystem, "input")) {
if (startswith(sysname, "event"))
type = DEVICE_TYPE_EVDEV;
}
return type;
}
static int session_device_verify(SessionDevice *sd) {
struct udev_device *dev, *p = NULL;
const char *sp, *node;
int r;
dev = udev_device_new_from_devnum(sd->session->manager->udev, 'c', sd->dev);
if (!dev)
return -ENODEV;
sp = udev_device_get_syspath(dev);
node = udev_device_get_devnode(dev);
if (!node) {
r = -EINVAL;
goto err_dev;
}
/* detect device type so we can find the correct sysfs parent */
sd->type = detect_device_type(dev);
if (sd->type == DEVICE_TYPE_UNKNOWN) {
r = -ENODEV;
goto err_dev;
} else if (sd->type == DEVICE_TYPE_EVDEV) {
/* for evdev devices we need the parent node as device */
p = dev;
dev = udev_device_get_parent_with_subsystem_devtype(p, "input", NULL);
if (!dev) {
r = -ENODEV;
goto err_dev;
}
sp = udev_device_get_syspath(dev);
logind: remove fbdev session-device support fbdev does not support access-handover so it is quite useless to route it through logind. If compositors want to use it they ought to open it themselves. It's highly recommended to be ignored entirely, though. fbdev is about to be deprecated in the kernel.
2013-10-01 18:08:54 +02:00
} else if (sd->type != DEVICE_TYPE_DRM) {
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
/* Prevent opening unsupported devices. Especially devices of
* subsystem "input" must be opened via the evdev node as
* we require EVIOCREVOKE. */
r = -ENODEV;
goto err_dev;
}
/* search for an existing seat device and return it if available */
sd->device = hashmap_get(sd->session->manager->devices, sp);
if (!sd->device) {
/* The caller might have gotten the udev event before we were
* able to process it. Hence, fake the "add" event and let the
* logind-manager handle the new device. */
r = manager_process_seat_device(sd->session->manager, dev);
if (r < 0)
goto err_dev;
/* if it's still not available, then the device is invalid */
sd->device = hashmap_get(sd->session->manager->devices, sp);
if (!sd->device) {
r = -ENODEV;
goto err_dev;
}
}
if (sd->device->seat != sd->session->seat) {
r = -EPERM;
goto err_dev;
}
sd->node = strdup(node);
if (!sd->node) {
r = -ENOMEM;
goto err_dev;
}
r = 0;
err_dev:
udev_device_unref(p ? : dev);
return r;
}
int session_device_new(Session *s, dev_t dev, SessionDevice **out) {
SessionDevice *sd;
int r;
assert(s);
assert(out);
if (!s->seat)
return -EPERM;
sd = new0(SessionDevice, 1);
if (!sd)
return -ENOMEM;
sd->session = s;
sd->dev = dev;
sd->fd = -1;
sd->type = DEVICE_TYPE_UNKNOWN;
r = session_device_verify(sd);
if (r < 0)
goto error;
logind: fix build for ARM with sizeof(dev_t) > sizeof(void*) Unfortunately on ARM-32 systems dev_t can be 64bit and thus we cannot store it easily in void* keys for hashtables. Fix that by passing a pointer to the dev_t variable instead.
2013-09-18 01:00:02 +02:00
r = hashmap_put(s->devices, &sd->dev, sd);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (r < 0) {
r = -ENOMEM;
goto error;
}
/* Open the device for the first time. We need a valid fd to pass back
* to the caller. If the session is not active, this _might_ immediately
* revoke access and thus invalidate the fd. But this is still needed
* to pass a valid fd back. */
sd->active = session_is_active(s);
logind: check whether first drmSetMaster succeeded The initial drmSetMaster may fail if there is an active master already. We must not assume that all existing clients comply to logind rules. We check for this during session-activation already but didn't during device setup. Fix this by checking the return code. As drmSetMaster has had horrible return codes in the past (0 for failure? EINVAL for denied access, ..) we need to be quite pedantic. To guarantee an open file-descriptor we need to close the device and reopen it without master if setting master failed first.
2013-10-01 17:53:43 +02:00
r = session_device_open(sd, sd->active);
if (r < 0) {
/* EINVAL _may_ mean a master is active; retry inactive */
if (sd->active && r == -EINVAL) {
sd->active = false;
r = session_device_open(sd, false);
}
if (r < 0)
goto error;
}
sd->fd = r;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
list: make our list macros a bit easier to use by not requring type spec on each invocation We can determine the list entry type via the typeof() gcc construct, and so we should to make the macros much shorter to use.
2013-10-14 06:10:14 +02:00
LIST_PREPEND(sd_by_device, sd->device->session_devices, sd);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
*out = sd;
return 0;
error:
logind: fix build for ARM with sizeof(dev_t) > sizeof(void*) Unfortunately on ARM-32 systems dev_t can be 64bit and thus we cannot store it easily in void* keys for hashtables. Fix that by passing a pointer to the dev_t variable instead.
2013-09-18 01:00:02 +02:00
hashmap_remove(s->devices, &sd->dev);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
free(sd->node);
free(sd);
return r;
}
void session_device_free(SessionDevice *sd) {
assert(sd);
session_device_stop(sd);
session_device_notify(sd, SESSION_DEVICE_RELEASE);
logind: ignore failing close() on session-devices Unfortunately, close() on a revoked/removed character-device fails with ENODEV. I tried tracking this down in the kernel, but couldn't figure out were exactly it comes from. However, can be easily reproduced with: fd = open("/dev/input/event0", O_RDWR); ioctl(fd, EVIOCREVOKE, 0); r = close(fd); A second close on @fd would return EBADF so the close is actually valid. We simply ignore close() errors for all session-devices as their access may be revoked asynchronously, or the device might get unplugged. We use close_nointr() in case anyone ever looks at the return value (or anyone runs "grep 'close(' -r src/" to find broken close() calls). Fixes: systemd-logind[31992]: Assertion 'close_nointr(fd) == 0' failed at src/shared/util.c:185, function close_nointr_nofail(). Aborting.
2013-11-28 14:51:40 +01:00
close_nointr(sd->fd);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
list: make our list macros a bit easier to use by not requring type spec on each invocation We can determine the list entry type via the typeof() gcc construct, and so we should to make the macros much shorter to use.
2013-10-14 06:10:14 +02:00
LIST_REMOVE(sd_by_device, sd->device->session_devices, sd);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
logind: fix build for ARM with sizeof(dev_t) > sizeof(void*) Unfortunately on ARM-32 systems dev_t can be 64bit and thus we cannot store it easily in void* keys for hashtables. Fix that by passing a pointer to the dev_t variable instead.
2013-09-18 01:00:02 +02:00
hashmap_remove(sd->session->devices, &sd->dev);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
free(sd->node);
free(sd);
}
void session_device_complete_pause(SessionDevice *sd) {
logind: implement generic multi-session This enables the multi-session capability for seats that don't have VTs. For legacy seats with VTs, everything stays the same. However, all other seats now also get the multi-session capability. The only feature that was missing was session-switching. As logind can force a session-switch and signal that via the "Active" property, we only need a way to allow synchronized/delayed session switches. Compositors need to cleanup some devices before acknowledging the session switch. Therefore, we use the session-devices to give compositors a chance to block a session-switch until they cleaned everything up. If you activate a session on a seat without VTs, we send a PauseDevice signal to the active session for every active device. Only once the session acknowledged all these with a PauseDeviceComplete() call, we perform the final session switch. One important note is that delayed session-switching is meant for backwards compatibility. New compositors or other sessions should really try to deal correctly with forced session switches! They only need to handle EACCES/EPERM from syscalls and treat them as "PauseDevice" signal. Following logind patches will add a timeout to session-switches which forces the switch if the active session does not react in a timely fashion. Moreover, explicit ForceActivate() calls might also be supported. Hence, sessions must not crash if their devices get paused.
2013-09-17 23:40:19 +02:00
SessionDevice *iter;
Iterator i;
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
if (!sd->active)
return;
session_device_stop(sd);
logind: implement generic multi-session This enables the multi-session capability for seats that don't have VTs. For legacy seats with VTs, everything stays the same. However, all other seats now also get the multi-session capability. The only feature that was missing was session-switching. As logind can force a session-switch and signal that via the "Active" property, we only need a way to allow synchronized/delayed session switches. Compositors need to cleanup some devices before acknowledging the session switch. Therefore, we use the session-devices to give compositors a chance to block a session-switch until they cleaned everything up. If you activate a session on a seat without VTs, we send a PauseDevice signal to the active session for every active device. Only once the session acknowledged all these with a PauseDeviceComplete() call, we perform the final session switch. One important note is that delayed session-switching is meant for backwards compatibility. New compositors or other sessions should really try to deal correctly with forced session switches! They only need to handle EACCES/EPERM from syscalls and treat them as "PauseDevice" signal. Following logind patches will add a timeout to session-switches which forces the switch if the active session does not react in a timely fashion. Moreover, explicit ForceActivate() calls might also be supported. Hence, sessions must not crash if their devices get paused.
2013-09-17 23:40:19 +02:00
/* if not all devices are paused, wait for further completion events */
HASHMAP_FOREACH(iter, sd->session->devices, i)
if (iter->active)
return;
/* complete any pending session switch */
seat_complete_switch(sd->session->seat);
logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.
2013-09-17 23:39:04 +02:00
}
void session_device_resume_all(Session *s) {
SessionDevice *sd;
Iterator i;
int r;
assert(s);
HASHMAP_FOREACH(sd, s->devices, i) {
if (!sd->active) {
r = session_device_start(sd);
if (!r)
session_device_notify(sd, SESSION_DEVICE_RESUME);
}
}
}
void session_device_pause_all(Session *s) {
SessionDevice *sd;
Iterator i;
assert(s);
HASHMAP_FOREACH(sd, s->devices, i) {
if (sd->active) {
session_device_stop(sd);
session_device_notify(sd, SESSION_DEVICE_PAUSE);
}
}
}
logind: implement generic multi-session This enables the multi-session capability for seats that don't have VTs. For legacy seats with VTs, everything stays the same. However, all other seats now also get the multi-session capability. The only feature that was missing was session-switching. As logind can force a session-switch and signal that via the "Active" property, we only need a way to allow synchronized/delayed session switches. Compositors need to cleanup some devices before acknowledging the session switch. Therefore, we use the session-devices to give compositors a chance to block a session-switch until they cleaned everything up. If you activate a session on a seat without VTs, we send a PauseDevice signal to the active session for every active device. Only once the session acknowledged all these with a PauseDeviceComplete() call, we perform the final session switch. One important note is that delayed session-switching is meant for backwards compatibility. New compositors or other sessions should really try to deal correctly with forced session switches! They only need to handle EACCES/EPERM from syscalls and treat them as "PauseDevice" signal. Following logind patches will add a timeout to session-switches which forces the switch if the active session does not react in a timely fashion. Moreover, explicit ForceActivate() calls might also be supported. Hence, sessions must not crash if their devices get paused.
2013-09-17 23:40:19 +02:00
unsigned int session_device_try_pause_all(Session *s) {
SessionDevice *sd;
Iterator i;
unsigned int num_pending = 0;
assert(s);
HASHMAP_FOREACH(sd, s->devices, i) {
if (sd->active) {
session_device_notify(sd, SESSION_DEVICE_TRY_PAUSE);
++num_pending;
}
}
return num_pending;
}
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