1 /* SPDX-License-Identifier: LGPL-2.1+ */
4 #include <linux/input.h>
10 #include "sd-daemon.h"
12 #include "alloc-util.h"
15 #include "logind-session-dbus.h"
16 #include "logind-session-device.h"
18 #include "parse-util.h"
21 enum SessionDeviceNotifications
{
22 SESSION_DEVICE_RESUME
,
23 SESSION_DEVICE_TRY_PAUSE
,
25 SESSION_DEVICE_RELEASE
,
28 static int session_device_notify(SessionDevice
*sd
, enum SessionDeviceNotifications type
) {
29 _cleanup_(sd_bus_message_unrefp
) sd_bus_message
*m
= NULL
;
30 _cleanup_free_
char *path
= NULL
;
32 uint32_t major
, minor
;
37 major
= major(sd
->dev
);
38 minor
= minor(sd
->dev
);
40 if (!sd
->session
->controller
)
43 path
= session_bus_path(sd
->session
);
47 r
= sd_bus_message_new_signal(
48 sd
->session
->manager
->bus
,
50 "org.freedesktop.login1.Session",
51 (type
== SESSION_DEVICE_RESUME
) ? "ResumeDevice" : "PauseDevice");
55 r
= sd_bus_message_set_destination(m
, sd
->session
->controller
);
61 case SESSION_DEVICE_RESUME
:
62 r
= sd_bus_message_append(m
, "uuh", major
, minor
, sd
->fd
);
67 case SESSION_DEVICE_TRY_PAUSE
:
71 case SESSION_DEVICE_PAUSE
:
75 case SESSION_DEVICE_RELEASE
:
84 r
= sd_bus_message_append(m
, "uus", major
, minor
, t
);
89 return sd_bus_send(sd
->session
->manager
->bus
, m
, NULL
);
92 static void sd_eviocrevoke(int fd
) {
93 static bool warned
= false;
97 if (ioctl(fd
, EVIOCREVOKE
, NULL
) < 0) {
99 if (errno
== EINVAL
&& !warned
) {
100 log_warning_errno(errno
, "Kernel does not support evdev-revocation: %m");
106 static int sd_drmsetmaster(int fd
) {
109 if (ioctl(fd
, DRM_IOCTL_SET_MASTER
, 0) < 0)
115 static int sd_drmdropmaster(int fd
) {
118 if (ioctl(fd
, DRM_IOCTL_DROP_MASTER
, 0) < 0)
124 static int session_device_open(SessionDevice
*sd
, bool active
) {
128 assert(sd
->type
!= DEVICE_TYPE_UNKNOWN
);
131 /* open device and try to get an udev_device from it */
132 fd
= open(sd
->node
, O_RDWR
|O_CLOEXEC
|O_NOCTTY
|O_NONBLOCK
);
138 case DEVICE_TYPE_DRM
:
140 /* Weird legacy DRM semantics might return an error even though we're master. No way to detect
141 * that so fail at all times and let caller retry in inactive state. */
142 r
= sd_drmsetmaster(fd
);
148 /* DRM-Master is granted to the first user who opens a device automatically (ughh,
149 * racy!). Hence, we just drop DRM-Master in case we were the first. */
150 (void) sd_drmdropmaster(fd
);
153 case DEVICE_TYPE_EVDEV
:
158 case DEVICE_TYPE_UNKNOWN
:
160 /* fallback for devices without synchronizations */
167 static int session_device_start(SessionDevice
*sd
) {
171 assert(session_is_active(sd
->session
));
178 case DEVICE_TYPE_DRM
:
180 return log_error_errno(SYNTHETIC_ERRNO(EBADF
),
181 "Failed to re-activate DRM fd, as the fd was lost (maybe logind restart went wrong?)");
183 /* Device is kept open. Simply call drmSetMaster() and hope there is no-one else. In case it fails, we
184 * keep the device paused. Maybe at some point we have a drmStealMaster(). */
185 r
= sd_drmsetmaster(sd
->fd
);
190 case DEVICE_TYPE_EVDEV
:
191 /* Evdev devices are revoked while inactive. Reopen it and we are fine. */
192 r
= session_device_open(sd
, true);
196 /* For evdev devices, the file descriptor might be left uninitialized. This might happen while resuming
197 * into a session and logind has been restarted right before. */
202 case DEVICE_TYPE_UNKNOWN
:
204 /* fallback for devices without synchronizations */
212 static void session_device_stop(SessionDevice
*sd
) {
220 case DEVICE_TYPE_DRM
:
222 log_error("Failed to de-activate DRM fd, as the fd was lost (maybe logind restart went wrong?)");
226 /* On DRM devices we simply drop DRM-Master but keep it open.
227 * This allows the user to keep resources allocated. The
228 * CAP_SYS_ADMIN restriction to DRM-Master prevents users from
229 * circumventing this. */
230 sd_drmdropmaster(sd
->fd
);
233 case DEVICE_TYPE_EVDEV
:
234 /* Revoke access on evdev file-descriptors during deactivation.
235 * This will basically prevent any operations on the fd and
236 * cannot be undone. Good side is: it needs no CAP_SYS_ADMIN
237 * protection this way. */
238 sd_eviocrevoke(sd
->fd
);
241 case DEVICE_TYPE_UNKNOWN
:
243 /* fallback for devices without synchronization */
250 static DeviceType
detect_device_type(sd_device
*dev
) {
251 const char *sysname
, *subsystem
;
252 DeviceType type
= DEVICE_TYPE_UNKNOWN
;
254 if (sd_device_get_sysname(dev
, &sysname
) < 0 ||
255 sd_device_get_subsystem(dev
, &subsystem
) < 0)
258 if (streq(subsystem
, "drm")) {
259 if (startswith(sysname
, "card"))
260 type
= DEVICE_TYPE_DRM
;
261 } else if (streq(subsystem
, "input")) {
262 if (startswith(sysname
, "event"))
263 type
= DEVICE_TYPE_EVDEV
;
269 static int session_device_verify(SessionDevice
*sd
) {
270 _cleanup_(sd_device_unrefp
) sd_device
*p
= NULL
;
271 const char *sp
, *node
;
275 r
= sd_device_new_from_devnum(&p
, 'c', sd
->dev
);
281 if (sd_device_get_syspath(dev
, &sp
) < 0 ||
282 sd_device_get_devname(dev
, &node
) < 0)
285 /* detect device type so we can find the correct sysfs parent */
286 sd
->type
= detect_device_type(dev
);
287 if (sd
->type
== DEVICE_TYPE_UNKNOWN
)
290 else if (sd
->type
== DEVICE_TYPE_EVDEV
) {
291 /* for evdev devices we need the parent node as device */
292 if (sd_device_get_parent_with_subsystem_devtype(p
, "input", NULL
, &dev
) < 0)
294 if (sd_device_get_syspath(dev
, &sp
) < 0)
297 } else if (sd
->type
!= DEVICE_TYPE_DRM
)
298 /* Prevent opening unsupported devices. Especially devices of
299 * subsystem "input" must be opened via the evdev node as
300 * we require EVIOCREVOKE. */
303 /* search for an existing seat device and return it if available */
304 sd
->device
= hashmap_get(sd
->session
->manager
->devices
, sp
);
306 /* The caller might have gotten the udev event before we were
307 * able to process it. Hence, fake the "add" event and let the
308 * logind-manager handle the new device. */
309 r
= manager_process_seat_device(sd
->session
->manager
, dev
);
313 /* if it's still not available, then the device is invalid */
314 sd
->device
= hashmap_get(sd
->session
->manager
->devices
, sp
);
319 if (sd
->device
->seat
!= sd
->session
->seat
)
322 sd
->node
= strdup(node
);
329 int session_device_new(Session
*s
, dev_t dev
, bool open_device
, SessionDevice
**out
) {
339 sd
= new0(SessionDevice
, 1);
346 sd
->type
= DEVICE_TYPE_UNKNOWN
;
348 r
= session_device_verify(sd
);
352 r
= hashmap_put(s
->devices
, &sd
->dev
, sd
);
357 /* Open the device for the first time. We need a valid fd to pass back
358 * to the caller. If the session is not active, this _might_ immediately
359 * revoke access and thus invalidate the fd. But this is still needed
360 * to pass a valid fd back. */
361 sd
->active
= session_is_active(s
);
362 r
= session_device_open(sd
, sd
->active
);
364 /* EINVAL _may_ mean a master is active; retry inactive */
365 if (sd
->active
&& r
== -EINVAL
) {
367 r
= session_device_open(sd
, false);
375 LIST_PREPEND(sd_by_device
, sd
->device
->session_devices
, sd
);
381 hashmap_remove(s
->devices
, &sd
->dev
);
387 void session_device_free(SessionDevice
*sd
) {
390 /* Make sure to remove the pushed fd. */
392 (void) sd_notifyf(false,
394 "FDNAME=session-%s-device-%u-%u",
395 sd
->session
->id
, major(sd
->dev
), minor(sd
->dev
));
397 session_device_stop(sd
);
398 session_device_notify(sd
, SESSION_DEVICE_RELEASE
);
401 LIST_REMOVE(sd_by_device
, sd
->device
->session_devices
, sd
);
403 hashmap_remove(sd
->session
->devices
, &sd
->dev
);
409 void session_device_complete_pause(SessionDevice
*sd
) {
416 session_device_stop(sd
);
418 /* if not all devices are paused, wait for further completion events */
419 HASHMAP_FOREACH(iter
, sd
->session
->devices
, i
)
423 /* complete any pending session switch */
424 seat_complete_switch(sd
->session
->seat
);
427 void session_device_resume_all(Session
*s
) {
433 HASHMAP_FOREACH(sd
, s
->devices
, i
) {
437 if (session_device_start(sd
) < 0)
439 if (session_device_save(sd
) < 0)
442 session_device_notify(sd
, SESSION_DEVICE_RESUME
);
446 void session_device_pause_all(Session
*s
) {
452 HASHMAP_FOREACH(sd
, s
->devices
, i
) {
456 session_device_stop(sd
);
457 session_device_notify(sd
, SESSION_DEVICE_PAUSE
);
461 unsigned session_device_try_pause_all(Session
*s
) {
462 unsigned num_pending
= 0;
468 HASHMAP_FOREACH(sd
, s
->devices
, i
) {
472 session_device_notify(sd
, SESSION_DEVICE_TRY_PAUSE
);
479 int session_device_save(SessionDevice
*sd
) {
480 _cleanup_free_
char *m
= NULL
;
486 /* Store device fd in PID1. It will send it back to us on restart so revocation will continue to work. To make
487 * things simple, send fds for all type of devices even if they don't support the revocation mechanism so we
488 * don't have to handle them differently later.
490 * Note: for device supporting revocation, PID1 will drop a stored fd automatically if the corresponding device
496 /* Session ID does not contain separators. */
497 id
= sd
->session
->id
;
498 assert(*(id
+ strcspn(id
, "-\n")) == '\0');
500 r
= asprintf(&m
, "FDSTORE=1\n"
501 "FDNAME=session-%s-device-%u-%u\n",
502 id
, major(sd
->dev
), minor(sd
->dev
));
506 r
= sd_pid_notify_with_fds(0, false, m
, &sd
->fd
, 1);
510 sd
->pushed_fd
= true;
514 void session_device_attach_fd(SessionDevice
*sd
, int fd
, bool active
) {
521 sd
->pushed_fd
= true;