2 This file is part of systemd.
4 Copyright 2013 David Herrmann
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
21 #include <linux/input.h>
23 #include <sys/ioctl.h>
24 #include <sys/types.h>
26 #if 0 /// elogind needs the systems udev header
32 #include "alloc-util.h"
35 #include "logind-session-device.h"
37 #include "sd-daemon.h"
40 enum SessionDeviceNotifications {
41 SESSION_DEVICE_RESUME,
42 SESSION_DEVICE_TRY_PAUSE,
44 SESSION_DEVICE_RELEASE,
47 static int session_device_notify(SessionDevice *sd, enum SessionDeviceNotifications type) {
48 _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
49 _cleanup_free_ char *path = NULL;
51 uint32_t major, minor;
56 major = major(sd->dev);
57 minor = minor(sd->dev);
59 if (!sd->session->controller)
62 path = session_bus_path(sd->session);
66 r = sd_bus_message_new_signal(
67 sd->session->manager->bus,
69 "org.freedesktop.login1.Session",
70 (type == SESSION_DEVICE_RESUME) ? "ResumeDevice" : "PauseDevice");
74 r = sd_bus_message_set_destination(m, sd->session->controller);
79 case SESSION_DEVICE_RESUME:
80 r = sd_bus_message_append(m, "uuh", major, minor, sd->fd);
84 case SESSION_DEVICE_TRY_PAUSE:
87 case SESSION_DEVICE_PAUSE:
90 case SESSION_DEVICE_RELEASE:
98 r = sd_bus_message_append(m, "uus", major, minor, t);
103 return sd_bus_send(sd->session->manager->bus, m, NULL);
106 static int sd_eviocrevoke(int fd) {
112 r = ioctl(fd, EVIOCREVOKE, NULL);
115 if (r == -EINVAL && !warned) {
117 log_warning("kernel does not support evdev-revocation");
124 static int sd_drmsetmaster(int fd) {
129 r = ioctl(fd, DRM_IOCTL_SET_MASTER, 0);
136 static int sd_drmdropmaster(int fd) {
141 r = ioctl(fd, DRM_IOCTL_DROP_MASTER, 0);
148 static int session_device_open(SessionDevice *sd, bool active) {
151 assert(sd->type != DEVICE_TYPE_UNKNOWN);
153 /* open device and try to get an udev_device from it */
154 fd = open(sd->node, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
159 case DEVICE_TYPE_DRM:
161 /* Weird legacy DRM semantics might return an error
162 * even though we're master. No way to detect that so
163 * fail at all times and let caller retry in inactive
165 r = sd_drmsetmaster(fd);
171 /* DRM-Master is granted to the first user who opens a
172 * device automatically (ughh, racy!). Hence, we just
173 * drop DRM-Master in case we were the first. */
174 sd_drmdropmaster(fd);
177 case DEVICE_TYPE_EVDEV:
181 case DEVICE_TYPE_UNKNOWN:
183 /* fallback for devices wihout synchronizations */
190 static int session_device_start(SessionDevice *sd) {
194 assert(session_is_active(sd->session));
200 case DEVICE_TYPE_DRM:
201 /* Device is kept open. Simply call drmSetMaster() and hope
202 * there is no-one else. In case it fails, we keep the device
203 * paused. Maybe at some point we have a drmStealMaster(). */
204 r = sd_drmsetmaster(sd->fd);
208 case DEVICE_TYPE_EVDEV:
209 /* Evdev devices are revoked while inactive. Reopen it and we
211 r = session_device_open(sd, true);
214 /* For evdev devices, the file descriptor might be left
215 * uninitialized. This might happen while resuming into a
216 * session and logind has been restarted right before. */
220 case DEVICE_TYPE_UNKNOWN:
222 /* fallback for devices wihout synchronizations */
230 static void session_device_stop(SessionDevice *sd) {
237 case DEVICE_TYPE_DRM:
238 /* On DRM devices we simply drop DRM-Master but keep it open.
239 * This allows the user to keep resources allocated. The
240 * CAP_SYS_ADMIN restriction to DRM-Master prevents users from
241 * circumventing this. */
242 sd_drmdropmaster(sd->fd);
244 case DEVICE_TYPE_EVDEV:
245 /* Revoke access on evdev file-descriptors during deactivation.
246 * This will basically prevent any operations on the fd and
247 * cannot be undone. Good side is: it needs no CAP_SYS_ADMIN
248 * protection this way. */
249 sd_eviocrevoke(sd->fd);
251 case DEVICE_TYPE_UNKNOWN:
253 /* fallback for devices without synchronization */
260 static DeviceType detect_device_type(struct udev_device *dev) {
261 const char *sysname, *subsystem;
264 sysname = udev_device_get_sysname(dev);
265 subsystem = udev_device_get_subsystem(dev);
266 type = DEVICE_TYPE_UNKNOWN;
268 if (streq_ptr(subsystem, "drm")) {
269 if (startswith(sysname, "card"))
270 type = DEVICE_TYPE_DRM;
271 } else if (streq_ptr(subsystem, "input")) {
272 if (startswith(sysname, "event"))
273 type = DEVICE_TYPE_EVDEV;
279 static int session_device_verify(SessionDevice *sd) {
280 struct udev_device *dev, *p = NULL;
281 const char *sp, *node;
284 dev = udev_device_new_from_devnum(sd->session->manager->udev, 'c', sd->dev);
288 sp = udev_device_get_syspath(dev);
289 node = udev_device_get_devnode(dev);
295 /* detect device type so we can find the correct sysfs parent */
296 sd->type = detect_device_type(dev);
297 if (sd->type == DEVICE_TYPE_UNKNOWN) {
300 } else if (sd->type == DEVICE_TYPE_EVDEV) {
301 /* for evdev devices we need the parent node as device */
303 dev = udev_device_get_parent_with_subsystem_devtype(p, "input", NULL);
308 sp = udev_device_get_syspath(dev);
309 } else if (sd->type != DEVICE_TYPE_DRM) {
310 /* Prevent opening unsupported devices. Especially devices of
311 * subsystem "input" must be opened via the evdev node as
312 * we require EVIOCREVOKE. */
317 /* search for an existing seat device and return it if available */
318 sd->device = hashmap_get(sd->session->manager->devices, sp);
320 /* The caller might have gotten the udev event before we were
321 * able to process it. Hence, fake the "add" event and let the
322 * logind-manager handle the new device. */
323 r = manager_process_seat_device(sd->session->manager, dev);
327 /* if it's still not available, then the device is invalid */
328 sd->device = hashmap_get(sd->session->manager->devices, sp);
335 if (sd->device->seat != sd->session->seat) {
340 sd->node = strdup(node);
348 udev_device_unref(p ? : dev);
352 int session_device_new(Session *s, dev_t dev, bool open_device, SessionDevice **out) {
362 sd = new0(SessionDevice, 1);
369 sd->type = DEVICE_TYPE_UNKNOWN;
371 r = session_device_verify(sd);
375 r = hashmap_put(s->devices, &sd->dev, sd);
382 /* Open the device for the first time. We need a valid fd to pass back
383 * to the caller. If the session is not active, this _might_ immediately
384 * revoke access and thus invalidate the fd. But this is still needed
385 * to pass a valid fd back. */
386 sd->active = session_is_active(s);
387 r = session_device_open(sd, sd->active);
389 /* EINVAL _may_ mean a master is active; retry inactive */
390 if (sd->active && r == -EINVAL) {
392 r = session_device_open(sd, false);
400 LIST_PREPEND(sd_by_device, sd->device->session_devices, sd);
406 hashmap_remove(s->devices, &sd->dev);
412 void session_device_free(SessionDevice *sd) {
415 session_device_stop(sd);
416 session_device_notify(sd, SESSION_DEVICE_RELEASE);
417 close_nointr(sd->fd);
419 LIST_REMOVE(sd_by_device, sd->device->session_devices, sd);
421 hashmap_remove(sd->session->devices, &sd->dev);
427 void session_device_complete_pause(SessionDevice *sd) {
434 session_device_stop(sd);
436 /* if not all devices are paused, wait for further completion events */
437 HASHMAP_FOREACH(iter, sd->session->devices, i)
441 /* complete any pending session switch */
442 seat_complete_switch(sd->session->seat);
445 void session_device_resume_all(Session *s) {
451 HASHMAP_FOREACH(sd, s->devices, i) {
453 if (session_device_start(sd) < 0)
455 if (session_device_save(sd) < 0)
457 session_device_notify(sd, SESSION_DEVICE_RESUME);
462 void session_device_pause_all(Session *s) {
468 HASHMAP_FOREACH(sd, s->devices, i) {
470 session_device_stop(sd);
471 session_device_notify(sd, SESSION_DEVICE_PAUSE);
476 unsigned int session_device_try_pause_all(Session *s) {
479 unsigned int num_pending = 0;
483 HASHMAP_FOREACH(sd, s->devices, i) {
485 session_device_notify(sd, SESSION_DEVICE_TRY_PAUSE);
493 int session_device_save(SessionDevice *sd) {
494 _cleanup_free_ char *state = NULL;
499 /* Store device fd in PID1. It will send it back to us on
500 * restart so revocation will continue to work. To make things
501 * simple, send fds for all type of devices even if they don't
502 * support the revocation mechanism so we don't have to handle
503 * them differently later.
505 * Note: for device supporting revocation, PID1 will drop a
506 * stored fd automatically if the corresponding device is
508 r = asprintf(&state, "FDSTORE=1\n"
509 "FDNAME=session-%s", sd->session->id);
513 return sd_pid_notify_with_fds(0, false, state, &sd->fd, 1);
516 void session_device_attach_fd(SessionDevice *sd, int fd, bool active) {