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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
118ecf32 DH |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2013 David Herrmann | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
118ecf32 | 21 | #include <fcntl.h> |
118ecf32 | 22 | #include <linux/input.h> |
118ecf32 DH |
23 | #include <string.h> |
24 | #include <sys/ioctl.h> | |
118ecf32 | 25 | #include <sys/types.h> |
118ecf32 | 26 | |
b4bbcaa9 TA |
27 | #include "libudev.h" |
28 | ||
b5efdb8a | 29 | #include "alloc-util.h" |
cc377381 | 30 | #include "bus-util.h" |
3ffd4af2 | 31 | #include "fd-util.h" |
cc377381 | 32 | #include "logind-session-device.h" |
3ffd4af2 | 33 | #include "missing.h" |
aed24c4c FB |
34 | #include "parse-util.h" |
35 | #include "sd-daemon.h" | |
3ffd4af2 | 36 | #include "util.h" |
118ecf32 DH |
37 | |
38 | enum SessionDeviceNotifications { | |
39 | SESSION_DEVICE_RESUME, | |
40 | SESSION_DEVICE_TRY_PAUSE, | |
41 | SESSION_DEVICE_PAUSE, | |
42 | SESSION_DEVICE_RELEASE, | |
43 | }; | |
44 | ||
cc377381 | 45 | static int session_device_notify(SessionDevice *sd, enum SessionDeviceNotifications type) { |
4afd3348 | 46 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; |
118ecf32 DH |
47 | _cleanup_free_ char *path = NULL; |
48 | const char *t = NULL; | |
081dfa85 | 49 | uint32_t major, minor; |
cc377381 | 50 | int r; |
118ecf32 DH |
51 | |
52 | assert(sd); | |
53 | ||
081dfa85 DH |
54 | major = major(sd->dev); |
55 | minor = minor(sd->dev); | |
56 | ||
118ecf32 | 57 | if (!sd->session->controller) |
cc377381 | 58 | return 0; |
118ecf32 DH |
59 | |
60 | path = session_bus_path(sd->session); | |
61 | if (!path) | |
cc377381 | 62 | return -ENOMEM; |
118ecf32 | 63 | |
cc377381 | 64 | r = sd_bus_message_new_signal( |
151b9b96 LP |
65 | sd->session->manager->bus, |
66 | &m, path, | |
cc377381 | 67 | "org.freedesktop.login1.Session", |
151b9b96 | 68 | (type == SESSION_DEVICE_RESUME) ? "ResumeDevice" : "PauseDevice"); |
118ecf32 | 69 | if (!m) |
cc377381 | 70 | return r; |
118ecf32 | 71 | |
cc377381 LP |
72 | r = sd_bus_message_set_destination(m, sd->session->controller); |
73 | if (r < 0) | |
74 | return r; | |
118ecf32 DH |
75 | |
76 | switch (type) { | |
77 | case SESSION_DEVICE_RESUME: | |
cc377381 LP |
78 | r = sd_bus_message_append(m, "uuh", major, minor, sd->fd); |
79 | if (r < 0) | |
80 | return r; | |
118ecf32 DH |
81 | break; |
82 | case SESSION_DEVICE_TRY_PAUSE: | |
83 | t = "pause"; | |
84 | break; | |
85 | case SESSION_DEVICE_PAUSE: | |
86 | t = "force"; | |
87 | break; | |
88 | case SESSION_DEVICE_RELEASE: | |
89 | t = "gone"; | |
90 | break; | |
91 | default: | |
cc377381 | 92 | return -EINVAL; |
118ecf32 DH |
93 | } |
94 | ||
cc377381 LP |
95 | if (t) { |
96 | r = sd_bus_message_append(m, "uus", major, minor, t); | |
97 | if (r < 0) | |
98 | return r; | |
99 | } | |
118ecf32 | 100 | |
cc377381 | 101 | return sd_bus_send(sd->session->manager->bus, m, NULL); |
118ecf32 DH |
102 | } |
103 | ||
104 | static int sd_eviocrevoke(int fd) { | |
105 | static bool warned; | |
106 | int r; | |
107 | ||
108 | assert(fd >= 0); | |
109 | ||
8dbce34b | 110 | r = ioctl(fd, EVIOCREVOKE, NULL); |
118ecf32 DH |
111 | if (r < 0) { |
112 | r = -errno; | |
113 | if (r == -EINVAL && !warned) { | |
114 | warned = true; | |
115 | log_warning("kernel does not support evdev-revocation"); | |
116 | } | |
117 | } | |
118 | ||
119 | return 0; | |
120 | } | |
121 | ||
122 | static int sd_drmsetmaster(int fd) { | |
123 | int r; | |
124 | ||
125 | assert(fd >= 0); | |
126 | ||
127 | r = ioctl(fd, DRM_IOCTL_SET_MASTER, 0); | |
128 | if (r < 0) | |
129 | return -errno; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int sd_drmdropmaster(int fd) { | |
135 | int r; | |
136 | ||
137 | assert(fd >= 0); | |
138 | ||
139 | r = ioctl(fd, DRM_IOCTL_DROP_MASTER, 0); | |
140 | if (r < 0) | |
141 | return -errno; | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | static int session_device_open(SessionDevice *sd, bool active) { | |
c2e5d024 | 147 | int fd, r; |
118ecf32 DH |
148 | |
149 | assert(sd->type != DEVICE_TYPE_UNKNOWN); | |
150 | ||
151 | /* open device and try to get an udev_device from it */ | |
152 | fd = open(sd->node, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); | |
153 | if (fd < 0) | |
154 | return -errno; | |
155 | ||
156 | switch (sd->type) { | |
157 | case DEVICE_TYPE_DRM: | |
c2e5d024 DH |
158 | if (active) { |
159 | /* Weird legacy DRM semantics might return an error | |
160 | * even though we're master. No way to detect that so | |
161 | * fail at all times and let caller retry in inactive | |
162 | * state. */ | |
163 | r = sd_drmsetmaster(fd); | |
164 | if (r < 0) { | |
d1107170 | 165 | close_nointr(fd); |
c2e5d024 DH |
166 | return r; |
167 | } | |
168 | } else { | |
118ecf32 DH |
169 | /* DRM-Master is granted to the first user who opens a |
170 | * device automatically (ughh, racy!). Hence, we just | |
171 | * drop DRM-Master in case we were the first. */ | |
172 | sd_drmdropmaster(fd); | |
173 | } | |
174 | break; | |
175 | case DEVICE_TYPE_EVDEV: | |
176 | if (!active) | |
177 | sd_eviocrevoke(fd); | |
178 | break; | |
118ecf32 DH |
179 | case DEVICE_TYPE_UNKNOWN: |
180 | default: | |
181 | /* fallback for devices wihout synchronizations */ | |
182 | break; | |
183 | } | |
184 | ||
185 | return fd; | |
186 | } | |
187 | ||
188 | static int session_device_start(SessionDevice *sd) { | |
189 | int r; | |
190 | ||
191 | assert(sd); | |
192 | assert(session_is_active(sd->session)); | |
193 | ||
194 | if (sd->active) | |
195 | return 0; | |
196 | ||
197 | switch (sd->type) { | |
198 | case DEVICE_TYPE_DRM: | |
199 | /* Device is kept open. Simply call drmSetMaster() and hope | |
200 | * there is no-one else. In case it fails, we keep the device | |
201 | * paused. Maybe at some point we have a drmStealMaster(). */ | |
202 | r = sd_drmsetmaster(sd->fd); | |
203 | if (r < 0) | |
204 | return r; | |
205 | break; | |
206 | case DEVICE_TYPE_EVDEV: | |
207 | /* Evdev devices are revoked while inactive. Reopen it and we | |
208 | * are fine. */ | |
209 | r = session_device_open(sd, true); | |
210 | if (r < 0) | |
211 | return r; | |
aed24c4c FB |
212 | /* For evdev devices, the file descriptor might be left |
213 | * uninitialized. This might happen while resuming into a | |
214 | * session and logind has been restarted right before. */ | |
215 | safe_close(sd->fd); | |
118ecf32 DH |
216 | sd->fd = r; |
217 | break; | |
118ecf32 DH |
218 | case DEVICE_TYPE_UNKNOWN: |
219 | default: | |
220 | /* fallback for devices wihout synchronizations */ | |
221 | break; | |
222 | } | |
223 | ||
224 | sd->active = true; | |
225 | return 0; | |
226 | } | |
227 | ||
228 | static void session_device_stop(SessionDevice *sd) { | |
229 | assert(sd); | |
230 | ||
231 | if (!sd->active) | |
232 | return; | |
233 | ||
234 | switch (sd->type) { | |
235 | case DEVICE_TYPE_DRM: | |
236 | /* On DRM devices we simply drop DRM-Master but keep it open. | |
237 | * This allows the user to keep resources allocated. The | |
238 | * CAP_SYS_ADMIN restriction to DRM-Master prevents users from | |
239 | * circumventing this. */ | |
240 | sd_drmdropmaster(sd->fd); | |
241 | break; | |
242 | case DEVICE_TYPE_EVDEV: | |
243 | /* Revoke access on evdev file-descriptors during deactivation. | |
244 | * This will basically prevent any operations on the fd and | |
245 | * cannot be undone. Good side is: it needs no CAP_SYS_ADMIN | |
246 | * protection this way. */ | |
247 | sd_eviocrevoke(sd->fd); | |
248 | break; | |
118ecf32 DH |
249 | case DEVICE_TYPE_UNKNOWN: |
250 | default: | |
251 | /* fallback for devices without synchronization */ | |
252 | break; | |
253 | } | |
254 | ||
255 | sd->active = false; | |
256 | } | |
257 | ||
258 | static DeviceType detect_device_type(struct udev_device *dev) { | |
259 | const char *sysname, *subsystem; | |
260 | DeviceType type; | |
261 | ||
262 | sysname = udev_device_get_sysname(dev); | |
263 | subsystem = udev_device_get_subsystem(dev); | |
264 | type = DEVICE_TYPE_UNKNOWN; | |
265 | ||
3a83f522 | 266 | if (streq_ptr(subsystem, "drm")) { |
118ecf32 DH |
267 | if (startswith(sysname, "card")) |
268 | type = DEVICE_TYPE_DRM; | |
269 | } else if (streq_ptr(subsystem, "input")) { | |
270 | if (startswith(sysname, "event")) | |
271 | type = DEVICE_TYPE_EVDEV; | |
272 | } | |
273 | ||
274 | return type; | |
275 | } | |
276 | ||
277 | static int session_device_verify(SessionDevice *sd) { | |
278 | struct udev_device *dev, *p = NULL; | |
279 | const char *sp, *node; | |
280 | int r; | |
281 | ||
282 | dev = udev_device_new_from_devnum(sd->session->manager->udev, 'c', sd->dev); | |
283 | if (!dev) | |
284 | return -ENODEV; | |
285 | ||
286 | sp = udev_device_get_syspath(dev); | |
287 | node = udev_device_get_devnode(dev); | |
288 | if (!node) { | |
289 | r = -EINVAL; | |
290 | goto err_dev; | |
291 | } | |
292 | ||
293 | /* detect device type so we can find the correct sysfs parent */ | |
294 | sd->type = detect_device_type(dev); | |
295 | if (sd->type == DEVICE_TYPE_UNKNOWN) { | |
296 | r = -ENODEV; | |
297 | goto err_dev; | |
298 | } else if (sd->type == DEVICE_TYPE_EVDEV) { | |
299 | /* for evdev devices we need the parent node as device */ | |
300 | p = dev; | |
301 | dev = udev_device_get_parent_with_subsystem_devtype(p, "input", NULL); | |
302 | if (!dev) { | |
303 | r = -ENODEV; | |
304 | goto err_dev; | |
305 | } | |
306 | sp = udev_device_get_syspath(dev); | |
3a83f522 | 307 | } else if (sd->type != DEVICE_TYPE_DRM) { |
118ecf32 DH |
308 | /* Prevent opening unsupported devices. Especially devices of |
309 | * subsystem "input" must be opened via the evdev node as | |
310 | * we require EVIOCREVOKE. */ | |
311 | r = -ENODEV; | |
312 | goto err_dev; | |
313 | } | |
314 | ||
315 | /* search for an existing seat device and return it if available */ | |
316 | sd->device = hashmap_get(sd->session->manager->devices, sp); | |
317 | if (!sd->device) { | |
318 | /* The caller might have gotten the udev event before we were | |
319 | * able to process it. Hence, fake the "add" event and let the | |
320 | * logind-manager handle the new device. */ | |
321 | r = manager_process_seat_device(sd->session->manager, dev); | |
322 | if (r < 0) | |
323 | goto err_dev; | |
324 | ||
325 | /* if it's still not available, then the device is invalid */ | |
326 | sd->device = hashmap_get(sd->session->manager->devices, sp); | |
327 | if (!sd->device) { | |
328 | r = -ENODEV; | |
329 | goto err_dev; | |
330 | } | |
331 | } | |
332 | ||
333 | if (sd->device->seat != sd->session->seat) { | |
334 | r = -EPERM; | |
335 | goto err_dev; | |
336 | } | |
337 | ||
338 | sd->node = strdup(node); | |
339 | if (!sd->node) { | |
340 | r = -ENOMEM; | |
341 | goto err_dev; | |
342 | } | |
343 | ||
344 | r = 0; | |
345 | err_dev: | |
346 | udev_device_unref(p ? : dev); | |
347 | return r; | |
348 | } | |
349 | ||
aed24c4c | 350 | int session_device_new(Session *s, dev_t dev, bool open_device, SessionDevice **out) { |
118ecf32 DH |
351 | SessionDevice *sd; |
352 | int r; | |
353 | ||
354 | assert(s); | |
355 | assert(out); | |
356 | ||
357 | if (!s->seat) | |
358 | return -EPERM; | |
359 | ||
360 | sd = new0(SessionDevice, 1); | |
361 | if (!sd) | |
362 | return -ENOMEM; | |
363 | ||
364 | sd->session = s; | |
365 | sd->dev = dev; | |
366 | sd->fd = -1; | |
367 | sd->type = DEVICE_TYPE_UNKNOWN; | |
368 | ||
369 | r = session_device_verify(sd); | |
370 | if (r < 0) | |
371 | goto error; | |
372 | ||
831dedef | 373 | r = hashmap_put(s->devices, &sd->dev, sd); |
118ecf32 DH |
374 | if (r < 0) { |
375 | r = -ENOMEM; | |
376 | goto error; | |
377 | } | |
378 | ||
aed24c4c FB |
379 | if (open_device) { |
380 | /* Open the device for the first time. We need a valid fd to pass back | |
381 | * to the caller. If the session is not active, this _might_ immediately | |
382 | * revoke access and thus invalidate the fd. But this is still needed | |
383 | * to pass a valid fd back. */ | |
384 | sd->active = session_is_active(s); | |
385 | r = session_device_open(sd, sd->active); | |
386 | if (r < 0) { | |
387 | /* EINVAL _may_ mean a master is active; retry inactive */ | |
388 | if (sd->active && r == -EINVAL) { | |
389 | sd->active = false; | |
390 | r = session_device_open(sd, false); | |
391 | } | |
392 | if (r < 0) | |
393 | goto error; | |
c2e5d024 | 394 | } |
aed24c4c | 395 | sd->fd = r; |
c2e5d024 | 396 | } |
118ecf32 | 397 | |
71fda00f | 398 | LIST_PREPEND(sd_by_device, sd->device->session_devices, sd); |
118ecf32 DH |
399 | |
400 | *out = sd; | |
401 | return 0; | |
402 | ||
403 | error: | |
831dedef | 404 | hashmap_remove(s->devices, &sd->dev); |
118ecf32 DH |
405 | free(sd->node); |
406 | free(sd); | |
407 | return r; | |
408 | } | |
409 | ||
410 | void session_device_free(SessionDevice *sd) { | |
411 | assert(sd); | |
412 | ||
4050e479 LP |
413 | if (sd->pushed_fd) { |
414 | const char *m; | |
415 | ||
416 | /* Remove the pushed fd again, just in case. */ | |
417 | ||
418 | m = strjoina("FDSTOREREMOVE=1\n" | |
419 | "FDNAME=session-", sd->session->id); | |
420 | ||
421 | (void) sd_notify(false, m); | |
422 | } | |
423 | ||
118ecf32 DH |
424 | session_device_stop(sd); |
425 | session_device_notify(sd, SESSION_DEVICE_RELEASE); | |
d1107170 | 426 | close_nointr(sd->fd); |
118ecf32 | 427 | |
71fda00f | 428 | LIST_REMOVE(sd_by_device, sd->device->session_devices, sd); |
118ecf32 | 429 | |
831dedef | 430 | hashmap_remove(sd->session->devices, &sd->dev); |
118ecf32 DH |
431 | |
432 | free(sd->node); | |
433 | free(sd); | |
434 | } | |
435 | ||
436 | void session_device_complete_pause(SessionDevice *sd) { | |
d7bd01b5 DH |
437 | SessionDevice *iter; |
438 | Iterator i; | |
439 | ||
118ecf32 DH |
440 | if (!sd->active) |
441 | return; | |
442 | ||
443 | session_device_stop(sd); | |
d7bd01b5 DH |
444 | |
445 | /* if not all devices are paused, wait for further completion events */ | |
446 | HASHMAP_FOREACH(iter, sd->session->devices, i) | |
447 | if (iter->active) | |
448 | return; | |
449 | ||
450 | /* complete any pending session switch */ | |
451 | seat_complete_switch(sd->session->seat); | |
118ecf32 DH |
452 | } |
453 | ||
454 | void session_device_resume_all(Session *s) { | |
455 | SessionDevice *sd; | |
456 | Iterator i; | |
118ecf32 DH |
457 | |
458 | assert(s); | |
459 | ||
460 | HASHMAP_FOREACH(sd, s->devices, i) { | |
461 | if (!sd->active) { | |
aed24c4c FB |
462 | if (session_device_start(sd) < 0) |
463 | continue; | |
464 | if (session_device_save(sd) < 0) | |
465 | continue; | |
466 | session_device_notify(sd, SESSION_DEVICE_RESUME); | |
118ecf32 DH |
467 | } |
468 | } | |
469 | } | |
470 | ||
471 | void session_device_pause_all(Session *s) { | |
472 | SessionDevice *sd; | |
473 | Iterator i; | |
474 | ||
475 | assert(s); | |
476 | ||
477 | HASHMAP_FOREACH(sd, s->devices, i) { | |
478 | if (sd->active) { | |
479 | session_device_stop(sd); | |
480 | session_device_notify(sd, SESSION_DEVICE_PAUSE); | |
481 | } | |
482 | } | |
483 | } | |
d7bd01b5 DH |
484 | |
485 | unsigned int session_device_try_pause_all(Session *s) { | |
486 | SessionDevice *sd; | |
487 | Iterator i; | |
488 | unsigned int num_pending = 0; | |
489 | ||
490 | assert(s); | |
491 | ||
492 | HASHMAP_FOREACH(sd, s->devices, i) { | |
493 | if (sd->active) { | |
494 | session_device_notify(sd, SESSION_DEVICE_TRY_PAUSE); | |
495 | ++num_pending; | |
496 | } | |
497 | } | |
498 | ||
499 | return num_pending; | |
500 | } | |
aed24c4c FB |
501 | |
502 | int session_device_save(SessionDevice *sd) { | |
4050e479 | 503 | const char *m; |
aed24c4c FB |
504 | int r; |
505 | ||
506 | assert(sd); | |
507 | ||
4050e479 LP |
508 | /* Store device fd in PID1. It will send it back to us on restart so revocation will continue to work. To make |
509 | * things simple, send fds for all type of devices even if they don't support the revocation mechanism so we | |
510 | * don't have to handle them differently later. | |
aed24c4c | 511 | * |
4050e479 LP |
512 | * Note: for device supporting revocation, PID1 will drop a stored fd automatically if the corresponding device |
513 | * is revoked. */ | |
514 | ||
515 | if (sd->pushed_fd) | |
516 | return 0; | |
517 | ||
518 | m = strjoina("FDSTORE=1\n" | |
519 | "FDNAME=session", sd->session->id); | |
520 | ||
521 | r = sd_pid_notify_with_fds(0, false, m, &sd->fd, 1); | |
aed24c4c | 522 | if (r < 0) |
4050e479 | 523 | return r; |
aed24c4c | 524 | |
4050e479 LP |
525 | sd->pushed_fd = true; |
526 | return 1; | |
aed24c4c FB |
527 | } |
528 | ||
529 | void session_device_attach_fd(SessionDevice *sd, int fd, bool active) { | |
530 | assert(fd > 0); | |
531 | assert(sd); | |
532 | assert(sd->fd < 0); | |
533 | assert(!sd->active); | |
534 | ||
535 | sd->fd = fd; | |
536 | sd->active = active; | |
537 | } |