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118ecf32 DH |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 David Herrmann | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <assert.h> | |
23 | #include <fcntl.h> | |
24 | #include <libudev.h> | |
25 | #include <linux/input.h> | |
26 | #include <linux/ioctl.h> | |
27 | #include <string.h> | |
28 | #include <sys/ioctl.h> | |
29 | #include <sys/stat.h> | |
30 | #include <sys/types.h> | |
31 | #include <unistd.h> | |
32 | ||
118ecf32 DH |
33 | #include "util.h" |
34 | #include "missing.h" | |
cc377381 LP |
35 | #include "bus-util.h" |
36 | #include "logind-session-device.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 LP |
45 | static int session_device_notify(SessionDevice *sd, enum SessionDeviceNotifications type) { |
46 | _cleanup_bus_message_unref_ 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 | ||
110 | r = ioctl(fd, EVIOCREVOKE, 1); | |
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; | |
d1107170 | 212 | close_nointr(sd->fd); |
118ecf32 DH |
213 | sd->fd = r; |
214 | break; | |
118ecf32 DH |
215 | case DEVICE_TYPE_UNKNOWN: |
216 | default: | |
217 | /* fallback for devices wihout synchronizations */ | |
218 | break; | |
219 | } | |
220 | ||
221 | sd->active = true; | |
222 | return 0; | |
223 | } | |
224 | ||
225 | static void session_device_stop(SessionDevice *sd) { | |
226 | assert(sd); | |
227 | ||
228 | if (!sd->active) | |
229 | return; | |
230 | ||
231 | switch (sd->type) { | |
232 | case DEVICE_TYPE_DRM: | |
233 | /* On DRM devices we simply drop DRM-Master but keep it open. | |
234 | * This allows the user to keep resources allocated. The | |
235 | * CAP_SYS_ADMIN restriction to DRM-Master prevents users from | |
236 | * circumventing this. */ | |
237 | sd_drmdropmaster(sd->fd); | |
238 | break; | |
239 | case DEVICE_TYPE_EVDEV: | |
240 | /* Revoke access on evdev file-descriptors during deactivation. | |
241 | * This will basically prevent any operations on the fd and | |
242 | * cannot be undone. Good side is: it needs no CAP_SYS_ADMIN | |
243 | * protection this way. */ | |
244 | sd_eviocrevoke(sd->fd); | |
245 | break; | |
118ecf32 DH |
246 | case DEVICE_TYPE_UNKNOWN: |
247 | default: | |
248 | /* fallback for devices without synchronization */ | |
249 | break; | |
250 | } | |
251 | ||
252 | sd->active = false; | |
253 | } | |
254 | ||
255 | static DeviceType detect_device_type(struct udev_device *dev) { | |
256 | const char *sysname, *subsystem; | |
257 | DeviceType type; | |
258 | ||
259 | sysname = udev_device_get_sysname(dev); | |
260 | subsystem = udev_device_get_subsystem(dev); | |
261 | type = DEVICE_TYPE_UNKNOWN; | |
262 | ||
3a83f522 | 263 | if (streq_ptr(subsystem, "drm")) { |
118ecf32 DH |
264 | if (startswith(sysname, "card")) |
265 | type = DEVICE_TYPE_DRM; | |
266 | } else if (streq_ptr(subsystem, "input")) { | |
267 | if (startswith(sysname, "event")) | |
268 | type = DEVICE_TYPE_EVDEV; | |
269 | } | |
270 | ||
271 | return type; | |
272 | } | |
273 | ||
274 | static int session_device_verify(SessionDevice *sd) { | |
275 | struct udev_device *dev, *p = NULL; | |
276 | const char *sp, *node; | |
277 | int r; | |
278 | ||
279 | dev = udev_device_new_from_devnum(sd->session->manager->udev, 'c', sd->dev); | |
280 | if (!dev) | |
281 | return -ENODEV; | |
282 | ||
283 | sp = udev_device_get_syspath(dev); | |
284 | node = udev_device_get_devnode(dev); | |
285 | if (!node) { | |
286 | r = -EINVAL; | |
287 | goto err_dev; | |
288 | } | |
289 | ||
290 | /* detect device type so we can find the correct sysfs parent */ | |
291 | sd->type = detect_device_type(dev); | |
292 | if (sd->type == DEVICE_TYPE_UNKNOWN) { | |
293 | r = -ENODEV; | |
294 | goto err_dev; | |
295 | } else if (sd->type == DEVICE_TYPE_EVDEV) { | |
296 | /* for evdev devices we need the parent node as device */ | |
297 | p = dev; | |
298 | dev = udev_device_get_parent_with_subsystem_devtype(p, "input", NULL); | |
299 | if (!dev) { | |
300 | r = -ENODEV; | |
301 | goto err_dev; | |
302 | } | |
303 | sp = udev_device_get_syspath(dev); | |
3a83f522 | 304 | } else if (sd->type != DEVICE_TYPE_DRM) { |
118ecf32 DH |
305 | /* Prevent opening unsupported devices. Especially devices of |
306 | * subsystem "input" must be opened via the evdev node as | |
307 | * we require EVIOCREVOKE. */ | |
308 | r = -ENODEV; | |
309 | goto err_dev; | |
310 | } | |
311 | ||
312 | /* search for an existing seat device and return it if available */ | |
313 | sd->device = hashmap_get(sd->session->manager->devices, sp); | |
314 | if (!sd->device) { | |
315 | /* The caller might have gotten the udev event before we were | |
316 | * able to process it. Hence, fake the "add" event and let the | |
317 | * logind-manager handle the new device. */ | |
318 | r = manager_process_seat_device(sd->session->manager, dev); | |
319 | if (r < 0) | |
320 | goto err_dev; | |
321 | ||
322 | /* if it's still not available, then the device is invalid */ | |
323 | sd->device = hashmap_get(sd->session->manager->devices, sp); | |
324 | if (!sd->device) { | |
325 | r = -ENODEV; | |
326 | goto err_dev; | |
327 | } | |
328 | } | |
329 | ||
330 | if (sd->device->seat != sd->session->seat) { | |
331 | r = -EPERM; | |
332 | goto err_dev; | |
333 | } | |
334 | ||
335 | sd->node = strdup(node); | |
336 | if (!sd->node) { | |
337 | r = -ENOMEM; | |
338 | goto err_dev; | |
339 | } | |
340 | ||
341 | r = 0; | |
342 | err_dev: | |
343 | udev_device_unref(p ? : dev); | |
344 | return r; | |
345 | } | |
346 | ||
347 | int session_device_new(Session *s, dev_t dev, SessionDevice **out) { | |
348 | SessionDevice *sd; | |
349 | int r; | |
350 | ||
351 | assert(s); | |
352 | assert(out); | |
353 | ||
354 | if (!s->seat) | |
355 | return -EPERM; | |
356 | ||
357 | sd = new0(SessionDevice, 1); | |
358 | if (!sd) | |
359 | return -ENOMEM; | |
360 | ||
361 | sd->session = s; | |
362 | sd->dev = dev; | |
363 | sd->fd = -1; | |
364 | sd->type = DEVICE_TYPE_UNKNOWN; | |
365 | ||
366 | r = session_device_verify(sd); | |
367 | if (r < 0) | |
368 | goto error; | |
369 | ||
831dedef | 370 | r = hashmap_put(s->devices, &sd->dev, sd); |
118ecf32 DH |
371 | if (r < 0) { |
372 | r = -ENOMEM; | |
373 | goto error; | |
374 | } | |
375 | ||
376 | /* Open the device for the first time. We need a valid fd to pass back | |
377 | * to the caller. If the session is not active, this _might_ immediately | |
378 | * revoke access and thus invalidate the fd. But this is still needed | |
379 | * to pass a valid fd back. */ | |
380 | sd->active = session_is_active(s); | |
c2e5d024 DH |
381 | r = session_device_open(sd, sd->active); |
382 | if (r < 0) { | |
383 | /* EINVAL _may_ mean a master is active; retry inactive */ | |
384 | if (sd->active && r == -EINVAL) { | |
385 | sd->active = false; | |
386 | r = session_device_open(sd, false); | |
387 | } | |
388 | if (r < 0) | |
389 | goto error; | |
390 | } | |
391 | sd->fd = r; | |
118ecf32 | 392 | |
71fda00f | 393 | LIST_PREPEND(sd_by_device, sd->device->session_devices, sd); |
118ecf32 DH |
394 | |
395 | *out = sd; | |
396 | return 0; | |
397 | ||
398 | error: | |
831dedef | 399 | hashmap_remove(s->devices, &sd->dev); |
118ecf32 DH |
400 | free(sd->node); |
401 | free(sd); | |
402 | return r; | |
403 | } | |
404 | ||
405 | void session_device_free(SessionDevice *sd) { | |
406 | assert(sd); | |
407 | ||
408 | session_device_stop(sd); | |
409 | session_device_notify(sd, SESSION_DEVICE_RELEASE); | |
d1107170 | 410 | close_nointr(sd->fd); |
118ecf32 | 411 | |
71fda00f | 412 | LIST_REMOVE(sd_by_device, sd->device->session_devices, sd); |
118ecf32 | 413 | |
831dedef | 414 | hashmap_remove(sd->session->devices, &sd->dev); |
118ecf32 DH |
415 | |
416 | free(sd->node); | |
417 | free(sd); | |
418 | } | |
419 | ||
420 | void session_device_complete_pause(SessionDevice *sd) { | |
d7bd01b5 DH |
421 | SessionDevice *iter; |
422 | Iterator i; | |
423 | ||
118ecf32 DH |
424 | if (!sd->active) |
425 | return; | |
426 | ||
427 | session_device_stop(sd); | |
d7bd01b5 DH |
428 | |
429 | /* if not all devices are paused, wait for further completion events */ | |
430 | HASHMAP_FOREACH(iter, sd->session->devices, i) | |
431 | if (iter->active) | |
432 | return; | |
433 | ||
434 | /* complete any pending session switch */ | |
435 | seat_complete_switch(sd->session->seat); | |
118ecf32 DH |
436 | } |
437 | ||
438 | void session_device_resume_all(Session *s) { | |
439 | SessionDevice *sd; | |
440 | Iterator i; | |
441 | int r; | |
442 | ||
443 | assert(s); | |
444 | ||
445 | HASHMAP_FOREACH(sd, s->devices, i) { | |
446 | if (!sd->active) { | |
447 | r = session_device_start(sd); | |
448 | if (!r) | |
449 | session_device_notify(sd, SESSION_DEVICE_RESUME); | |
450 | } | |
451 | } | |
452 | } | |
453 | ||
454 | void session_device_pause_all(Session *s) { | |
455 | SessionDevice *sd; | |
456 | Iterator i; | |
457 | ||
458 | assert(s); | |
459 | ||
460 | HASHMAP_FOREACH(sd, s->devices, i) { | |
461 | if (sd->active) { | |
462 | session_device_stop(sd); | |
463 | session_device_notify(sd, SESSION_DEVICE_PAUSE); | |
464 | } | |
465 | } | |
466 | } | |
d7bd01b5 DH |
467 | |
468 | unsigned int session_device_try_pause_all(Session *s) { | |
469 | SessionDevice *sd; | |
470 | Iterator i; | |
471 | unsigned int num_pending = 0; | |
472 | ||
473 | assert(s); | |
474 | ||
475 | HASHMAP_FOREACH(sd, s->devices, i) { | |
476 | if (sd->active) { | |
477 | session_device_notify(sd, SESSION_DEVICE_TRY_PAUSE); | |
478 | ++num_pending; | |
479 | } | |
480 | } | |
481 | ||
482 | return num_pending; | |
483 | } |