1 /* SPDX-License-Identifier: LGPL-2.1+ */
4 #include <linux/input.h>
9 #if 0 /// elogind needs the systems udev header
15 #include "alloc-util.h"
18 #include "logind-session-device.h"
20 #include "parse-util.h"
21 #include "sd-daemon.h"
24 enum SessionDeviceNotifications {
25 SESSION_DEVICE_RESUME,
26 SESSION_DEVICE_TRY_PAUSE,
28 SESSION_DEVICE_RELEASE,
31 static int session_device_notify(SessionDevice *sd, enum SessionDeviceNotifications type) {
32 _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
33 _cleanup_free_ char *path = NULL;
35 uint32_t major, minor;
40 major = major(sd->dev);
41 minor = minor(sd->dev);
43 if (!sd->session->controller)
46 path = session_bus_path(sd->session);
50 r = sd_bus_message_new_signal(
51 sd->session->manager->bus,
53 "org.freedesktop.login1.Session",
54 (type == SESSION_DEVICE_RESUME) ? "ResumeDevice" : "PauseDevice");
58 r = sd_bus_message_set_destination(m, sd->session->controller);
64 case SESSION_DEVICE_RESUME:
65 r = sd_bus_message_append(m, "uuh", major, minor, sd->fd);
70 case SESSION_DEVICE_TRY_PAUSE:
74 case SESSION_DEVICE_PAUSE:
78 case SESSION_DEVICE_RELEASE:
87 r = sd_bus_message_append(m, "uus", major, minor, t);
92 return sd_bus_send(sd->session->manager->bus, m, NULL);
95 static void sd_eviocrevoke(int fd) {
96 static bool warned = false;
100 if (ioctl(fd, EVIOCREVOKE, NULL) < 0) {
102 if (errno == EINVAL && !warned) {
103 log_warning_errno(errno, "Kernel does not support evdev-revocation: %m");
109 static int sd_drmsetmaster(int fd) {
112 if (ioctl(fd, DRM_IOCTL_SET_MASTER, 0) < 0)
118 static int sd_drmdropmaster(int fd) {
121 if (ioctl(fd, DRM_IOCTL_DROP_MASTER, 0) < 0)
127 static int session_device_open(SessionDevice *sd, bool active) {
131 assert(sd->type != DEVICE_TYPE_UNKNOWN);
134 /* open device and try to get an udev_device from it */
135 fd = open(sd->node, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
141 case DEVICE_TYPE_DRM:
143 /* Weird legacy DRM semantics might return an error even though we're master. No way to detect
144 * that so fail at all times and let caller retry in inactive state. */
145 r = sd_drmsetmaster(fd);
151 /* DRM-Master is granted to the first user who opens a device automatically (ughh,
152 * racy!). Hence, we just drop DRM-Master in case we were the first. */
153 (void) sd_drmdropmaster(fd);
156 case DEVICE_TYPE_EVDEV:
161 case DEVICE_TYPE_UNKNOWN:
163 /* fallback for devices wihout synchronizations */
170 static int session_device_start(SessionDevice *sd) {
174 assert(session_is_active(sd->session));
181 case DEVICE_TYPE_DRM:
183 log_error("Failed to re-activate DRM fd, as the fd was lost (maybe logind restart went wrong?)");
187 /* Device is kept open. Simply call drmSetMaster() and hope there is no-one else. In case it fails, we
188 * keep the device paused. Maybe at some point we have a drmStealMaster(). */
189 r = sd_drmsetmaster(sd->fd);
194 case DEVICE_TYPE_EVDEV:
195 /* Evdev devices are revoked while inactive. Reopen it and we are fine. */
196 r = session_device_open(sd, true);
200 /* For evdev devices, the file descriptor might be left uninitialized. This might happen while resuming
201 * into a session and logind has been restarted right before. */
206 case DEVICE_TYPE_UNKNOWN:
208 /* fallback for devices without synchronizations */
216 static void session_device_stop(SessionDevice *sd) {
224 case DEVICE_TYPE_DRM:
226 log_error("Failed to de-activate DRM fd, as the fd was lost (maybe logind restart went wrong?)");
230 /* On DRM devices we simply drop DRM-Master but keep it open.
231 * This allows the user to keep resources allocated. The
232 * CAP_SYS_ADMIN restriction to DRM-Master prevents users from
233 * circumventing this. */
234 sd_drmdropmaster(sd->fd);
237 case DEVICE_TYPE_EVDEV:
238 /* Revoke access on evdev file-descriptors during deactivation.
239 * This will basically prevent any operations on the fd and
240 * cannot be undone. Good side is: it needs no CAP_SYS_ADMIN
241 * protection this way. */
242 sd_eviocrevoke(sd->fd);
245 case DEVICE_TYPE_UNKNOWN:
247 /* fallback for devices without synchronization */
254 static DeviceType detect_device_type(struct udev_device *dev) {
255 const char *sysname, *subsystem;
258 sysname = udev_device_get_sysname(dev);
259 subsystem = udev_device_get_subsystem(dev);
260 type = DEVICE_TYPE_UNKNOWN;
262 if (streq_ptr(subsystem, "drm")) {
263 if (startswith(sysname, "card"))
264 type = DEVICE_TYPE_DRM;
265 } else if (streq_ptr(subsystem, "input")) {
266 if (startswith(sysname, "event"))
267 type = DEVICE_TYPE_EVDEV;
273 static int session_device_verify(SessionDevice *sd) {
274 struct udev_device *dev, *p = NULL;
275 const char *sp, *node;
278 dev = udev_device_new_from_devnum(sd->session->manager->udev, 'c', sd->dev);
282 sp = udev_device_get_syspath(dev);
283 node = udev_device_get_devnode(dev);
289 /* detect device type so we can find the correct sysfs parent */
290 sd->type = detect_device_type(dev);
291 if (sd->type == DEVICE_TYPE_UNKNOWN) {
294 } else if (sd->type == DEVICE_TYPE_EVDEV) {
295 /* for evdev devices we need the parent node as device */
297 dev = udev_device_get_parent_with_subsystem_devtype(p, "input", NULL);
302 sp = udev_device_get_syspath(dev);
303 } else if (sd->type != DEVICE_TYPE_DRM) {
304 /* Prevent opening unsupported devices. Especially devices of
305 * subsystem "input" must be opened via the evdev node as
306 * we require EVIOCREVOKE. */
311 /* search for an existing seat device and return it if available */
312 sd->device = hashmap_get(sd->session->manager->devices, sp);
314 /* The caller might have gotten the udev event before we were
315 * able to process it. Hence, fake the "add" event and let the
316 * logind-manager handle the new device. */
317 r = manager_process_seat_device(sd->session->manager, dev);
321 /* if it's still not available, then the device is invalid */
322 sd->device = hashmap_get(sd->session->manager->devices, sp);
329 if (sd->device->seat != sd->session->seat) {
334 sd->node = strdup(node);
342 udev_device_unref(p ? : dev);
346 int session_device_new(Session *s, dev_t dev, bool open_device, SessionDevice **out) {
356 sd = new0(SessionDevice, 1);
363 sd->type = DEVICE_TYPE_UNKNOWN;
365 r = session_device_verify(sd);
369 r = hashmap_put(s->devices, &sd->dev, sd);
374 /* Open the device for the first time. We need a valid fd to pass back
375 * to the caller. If the session is not active, this _might_ immediately
376 * revoke access and thus invalidate the fd. But this is still needed
377 * to pass a valid fd back. */
378 sd->active = session_is_active(s);
379 r = session_device_open(sd, sd->active);
381 /* EINVAL _may_ mean a master is active; retry inactive */
382 if (sd->active && r == -EINVAL) {
384 r = session_device_open(sd, false);
392 LIST_PREPEND(sd_by_device, sd->device->session_devices, sd);
398 hashmap_remove(s->devices, &sd->dev);
404 void session_device_free(SessionDevice *sd) {
407 /* Make sure to remove the pushed fd. */
409 _cleanup_free_ char *m = NULL;
413 /* Session ID does not contain separators. */
414 id = sd->session->id;
415 assert(*(id + strcspn(id, "-\n")) == '\0');
417 r = asprintf(&m, "FDSTOREREMOVE=1\n"
418 "FDNAME=session-%s-device-%u-%u\n",
419 id, major(sd->dev), minor(sd->dev));
421 (void) sd_notify(false, m);
424 session_device_stop(sd);
425 session_device_notify(sd, SESSION_DEVICE_RELEASE);
428 LIST_REMOVE(sd_by_device, sd->device->session_devices, sd);
430 hashmap_remove(sd->session->devices, &sd->dev);
436 void session_device_complete_pause(SessionDevice *sd) {
443 session_device_stop(sd);
445 /* if not all devices are paused, wait for further completion events */
446 HASHMAP_FOREACH(iter, sd->session->devices, i)
450 /* complete any pending session switch */
451 seat_complete_switch(sd->session->seat);
454 void session_device_resume_all(Session *s) {
460 HASHMAP_FOREACH(sd, s->devices, i) {
464 if (session_device_start(sd) < 0)
466 if (session_device_save(sd) < 0)
469 session_device_notify(sd, SESSION_DEVICE_RESUME);
473 void session_device_pause_all(Session *s) {
479 HASHMAP_FOREACH(sd, s->devices, i) {
483 session_device_stop(sd);
484 session_device_notify(sd, SESSION_DEVICE_PAUSE);
488 unsigned int session_device_try_pause_all(Session *s) {
489 unsigned num_pending = 0;
495 HASHMAP_FOREACH(sd, s->devices, i) {
499 session_device_notify(sd, SESSION_DEVICE_TRY_PAUSE);
506 int session_device_save(SessionDevice *sd) {
507 _cleanup_free_ char *m = NULL;
513 /* Store device fd in PID1. It will send it back to us on restart so revocation will continue to work. To make
514 * things simple, send fds for all type of devices even if they don't support the revocation mechanism so we
515 * don't have to handle them differently later.
517 * Note: for device supporting revocation, PID1 will drop a stored fd automatically if the corresponding device
523 /* Session ID does not contain separators. */
524 id = sd->session->id;
525 assert(*(id + strcspn(id, "-\n")) == '\0');
527 r = asprintf(&m, "FDSTORE=1\n"
528 "FDNAME=session-%s-device-%u-%u\n",
529 id, major(sd->dev), minor(sd->dev));
533 r = sd_pid_notify_with_fds(0, false, m, &sd->fd, 1);
537 sd->pushed_fd = true;
541 void session_device_attach_fd(SessionDevice *sd, int fd, bool active) {
548 sd->pushed_fd = true;