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1/*
2 * User level driver support for input subsystem
3 *
4 * Heavily based on evdev.c by Vojtech Pavlik
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
21 *
22 * Changes/Revisions:
23 * 0.4 01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
24 * - add UI_GET_SYSNAME ioctl
25 * 0.3 09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
26 * - updated ff support for the changes in kernel interface
27 * - added MODULE_VERSION
28 * 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>)
29 * - added force feedback support
30 * - added UI_SET_PHYS
31 * 0.1 20/06/2002
32 * - first public version
33 */
34#include <linux/poll.h>
35#include <linux/sched.h>
36#include <linux/slab.h>
37#include <linux/module.h>
38#include <linux/init.h>
39#include <linux/fs.h>
40#include <linux/miscdevice.h>
41#include <linux/uinput.h>
42#include <linux/input/mt.h>
43#include "../input-compat.h"
44
45static int uinput_dev_event(struct input_dev *dev,
46 unsigned int type, unsigned int code, int value)
47{
48 struct uinput_device *udev = input_get_drvdata(dev);
49
50 udev->buff[udev->head].type = type;
51 udev->buff[udev->head].code = code;
52 udev->buff[udev->head].value = value;
53 do_gettimeofday(&udev->buff[udev->head].time);
54 udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
55
56 wake_up_interruptible(&udev->waitq);
57
58 return 0;
59}
60
61/* Atomically allocate an ID for the given request. Returns 0 on success. */
62static bool uinput_request_alloc_id(struct uinput_device *udev,
63 struct uinput_request *request)
64{
65 unsigned int id;
66 bool reserved = false;
67
68 spin_lock(&udev->requests_lock);
69
70 for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
71 if (!udev->requests[id]) {
72 request->id = id;
73 udev->requests[id] = request;
74 reserved = true;
75 break;
76 }
77 }
78
79 spin_unlock(&udev->requests_lock);
80 return reserved;
81}
82
83static struct uinput_request *uinput_request_find(struct uinput_device *udev,
84 unsigned int id)
85{
86 /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
87 if (id >= UINPUT_NUM_REQUESTS)
88 return NULL;
89
90 return udev->requests[id];
91}
92
93static int uinput_request_reserve_slot(struct uinput_device *udev,
94 struct uinput_request *request)
95{
96 /* Allocate slot. If none are available right away, wait. */
97 return wait_event_interruptible(udev->requests_waitq,
98 uinput_request_alloc_id(udev, request));
99}
100
101static void uinput_request_done(struct uinput_device *udev,
102 struct uinput_request *request)
103{
104 /* Mark slot as available */
105 udev->requests[request->id] = NULL;
106 wake_up(&udev->requests_waitq);
107
108 complete(&request->done);
109}
110
111static int uinput_request_send(struct uinput_device *udev,
112 struct uinput_request *request)
113{
114 int retval;
115
116 retval = mutex_lock_interruptible(&udev->mutex);
117 if (retval)
118 return retval;
119
120 if (udev->state != UIST_CREATED) {
121 retval = -ENODEV;
122 goto out;
123 }
124
125 init_completion(&request->done);
126
127 /*
128 * Tell our userspace application about this new request
129 * by queueing an input event.
130 */
131 uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
132
133 out:
134 mutex_unlock(&udev->mutex);
135 return retval;
136}
137
138static int uinput_request_submit(struct uinput_device *udev,
139 struct uinput_request *request)
140{
141 int error;
142
143 error = uinput_request_reserve_slot(udev, request);
144 if (error)
145 return error;
146
147 error = uinput_request_send(udev, request);
148 if (error) {
149 uinput_request_done(udev, request);
150 return error;
151 }
152
153 wait_for_completion(&request->done);
154 return request->retval;
155}
156
157/*
158 * Fail all outstanding requests so handlers don't wait for the userspace
159 * to finish processing them.
160 */
161static void uinput_flush_requests(struct uinput_device *udev)
162{
163 struct uinput_request *request;
164 int i;
165
166 spin_lock(&udev->requests_lock);
167
168 for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
169 request = udev->requests[i];
170 if (request) {
171 request->retval = -ENODEV;
172 uinput_request_done(udev, request);
173 }
174 }
175
176 spin_unlock(&udev->requests_lock);
177}
178
179static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
180{
181 uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
182}
183
184static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
185{
186 uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
187}
188
189static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
190{
191 return uinput_dev_event(dev, EV_FF, effect_id, value);
192}
193
194static int uinput_dev_upload_effect(struct input_dev *dev,
195 struct ff_effect *effect,
196 struct ff_effect *old)
197{
198 struct uinput_device *udev = input_get_drvdata(dev);
199 struct uinput_request request;
200
201 /*
202 * uinput driver does not currently support periodic effects with
203 * custom waveform since it does not have a way to pass buffer of
204 * samples (custom_data) to userspace. If ever there is a device
205 * supporting custom waveforms we would need to define an additional
206 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
207 */
208 if (effect->type == FF_PERIODIC &&
209 effect->u.periodic.waveform == FF_CUSTOM)
210 return -EINVAL;
211
212 request.code = UI_FF_UPLOAD;
213 request.u.upload.effect = effect;
214 request.u.upload.old = old;
215
216 return uinput_request_submit(udev, &request);
217}
218
219static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
220{
221 struct uinput_device *udev = input_get_drvdata(dev);
222 struct uinput_request request;
223
224 if (!test_bit(EV_FF, dev->evbit))
225 return -ENOSYS;
226
227 request.code = UI_FF_ERASE;
228 request.u.effect_id = effect_id;
229
230 return uinput_request_submit(udev, &request);
231}
232
233static void uinput_destroy_device(struct uinput_device *udev)
234{
235 const char *name, *phys;
236 struct input_dev *dev = udev->dev;
237 enum uinput_state old_state = udev->state;
238
239 udev->state = UIST_NEW_DEVICE;
240
241 if (dev) {
242 name = dev->name;
243 phys = dev->phys;
244 if (old_state == UIST_CREATED) {
245 uinput_flush_requests(udev);
246 input_unregister_device(dev);
247 } else {
248 input_free_device(dev);
249 }
250 kfree(name);
251 kfree(phys);
252 udev->dev = NULL;
253 }
254}
255
256static int uinput_create_device(struct uinput_device *udev)
257{
258 struct input_dev *dev = udev->dev;
259 int error;
260
261 if (udev->state != UIST_SETUP_COMPLETE) {
262 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
263 return -EINVAL;
264 }
265
266 if (udev->ff_effects_max) {
267 error = input_ff_create(dev, udev->ff_effects_max);
268 if (error)
269 goto fail1;
270
271 dev->ff->upload = uinput_dev_upload_effect;
272 dev->ff->erase = uinput_dev_erase_effect;
273 dev->ff->playback = uinput_dev_playback;
274 dev->ff->set_gain = uinput_dev_set_gain;
275 dev->ff->set_autocenter = uinput_dev_set_autocenter;
276 }
277
278 error = input_register_device(udev->dev);
279 if (error)
280 goto fail2;
281
282 udev->state = UIST_CREATED;
283
284 return 0;
285
286 fail2: input_ff_destroy(dev);
287 fail1: uinput_destroy_device(udev);
288 return error;
289}
290
291static int uinput_open(struct inode *inode, struct file *file)
292{
293 struct uinput_device *newdev;
294
295 newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
296 if (!newdev)
297 return -ENOMEM;
298
299 mutex_init(&newdev->mutex);
300 spin_lock_init(&newdev->requests_lock);
301 init_waitqueue_head(&newdev->requests_waitq);
302 init_waitqueue_head(&newdev->waitq);
303 newdev->state = UIST_NEW_DEVICE;
304
305 file->private_data = newdev;
306 nonseekable_open(inode, file);
307
308 return 0;
309}
310
311static int uinput_validate_absbits(struct input_dev *dev)
312{
313 unsigned int cnt;
314 int retval = 0;
315
316 for (cnt = 0; cnt < ABS_CNT; cnt++) {
317 int min, max;
318 if (!test_bit(cnt, dev->absbit))
319 continue;
320
321 min = input_abs_get_min(dev, cnt);
322 max = input_abs_get_max(dev, cnt);
323
324 if ((min != 0 || max != 0) && max <= min) {
325 printk(KERN_DEBUG
326 "%s: invalid abs[%02x] min:%d max:%d\n",
327 UINPUT_NAME, cnt,
328 input_abs_get_min(dev, cnt),
329 input_abs_get_max(dev, cnt));
330 retval = -EINVAL;
331 break;
332 }
333
334 if (input_abs_get_flat(dev, cnt) >
335 input_abs_get_max(dev, cnt) - input_abs_get_min(dev, cnt)) {
336 printk(KERN_DEBUG
337 "%s: abs_flat #%02x out of range: %d "
338 "(min:%d/max:%d)\n",
339 UINPUT_NAME, cnt,
340 input_abs_get_flat(dev, cnt),
341 input_abs_get_min(dev, cnt),
342 input_abs_get_max(dev, cnt));
343 retval = -EINVAL;
344 break;
345 }
346 }
347 return retval;
348}
349
350static int uinput_allocate_device(struct uinput_device *udev)
351{
352 udev->dev = input_allocate_device();
353 if (!udev->dev)
354 return -ENOMEM;
355
356 udev->dev->event = uinput_dev_event;
357 input_set_drvdata(udev->dev, udev);
358
359 return 0;
360}
361
362static int uinput_setup_device(struct uinput_device *udev,
363 const char __user *buffer, size_t count)
364{
365 struct uinput_user_dev *user_dev;
366 struct input_dev *dev;
367 int i;
368 int retval;
369
370 if (count != sizeof(struct uinput_user_dev))
371 return -EINVAL;
372
373 if (!udev->dev) {
374 retval = uinput_allocate_device(udev);
375 if (retval)
376 return retval;
377 }
378
379 dev = udev->dev;
380
381 user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
382 if (IS_ERR(user_dev))
383 return PTR_ERR(user_dev);
384
385 udev->ff_effects_max = user_dev->ff_effects_max;
386
387 /* Ensure name is filled in */
388 if (!user_dev->name[0]) {
389 retval = -EINVAL;
390 goto exit;
391 }
392
393 kfree(dev->name);
394 dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
395 GFP_KERNEL);
396 if (!dev->name) {
397 retval = -ENOMEM;
398 goto exit;
399 }
400
401 dev->id.bustype = user_dev->id.bustype;
402 dev->id.vendor = user_dev->id.vendor;
403 dev->id.product = user_dev->id.product;
404 dev->id.version = user_dev->id.version;
405
406 for (i = 0; i < ABS_CNT; i++) {
407 input_abs_set_max(dev, i, user_dev->absmax[i]);
408 input_abs_set_min(dev, i, user_dev->absmin[i]);
409 input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
410 input_abs_set_flat(dev, i, user_dev->absflat[i]);
411 }
412
413 /* check if absmin/absmax/absfuzz/absflat are filled as
414 * told in Documentation/input/input-programming.txt */
415 if (test_bit(EV_ABS, dev->evbit)) {
416 retval = uinput_validate_absbits(dev);
417 if (retval < 0)
418 goto exit;
419 if (test_bit(ABS_MT_SLOT, dev->absbit)) {
420 int nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
421 input_mt_init_slots(dev, nslot, 0);
422 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
423 input_set_events_per_packet(dev, 60);
424 }
425 }
426
427 udev->state = UIST_SETUP_COMPLETE;
428 retval = count;
429
430 exit:
431 kfree(user_dev);
432 return retval;
433}
434
435static ssize_t uinput_inject_events(struct uinput_device *udev,
436 const char __user *buffer, size_t count)
437{
438 struct input_event ev;
439 size_t bytes = 0;
440
441 if (count != 0 && count < input_event_size())
442 return -EINVAL;
443
444 while (bytes + input_event_size() <= count) {
445 /*
446 * Note that even if some events were fetched successfully
447 * we are still going to return EFAULT instead of partial
448 * count to let userspace know that it got it's buffers
449 * all wrong.
450 */
451 if (input_event_from_user(buffer + bytes, &ev))
452 return -EFAULT;
453
454 input_event(udev->dev, ev.type, ev.code, ev.value);
455 bytes += input_event_size();
456 }
457
458 return bytes;
459}
460
461static ssize_t uinput_write(struct file *file, const char __user *buffer,
462 size_t count, loff_t *ppos)
463{
464 struct uinput_device *udev = file->private_data;
465 int retval;
466
467 if (count == 0)
468 return 0;
469
470 retval = mutex_lock_interruptible(&udev->mutex);
471 if (retval)
472 return retval;
473
474 retval = udev->state == UIST_CREATED ?
475 uinput_inject_events(udev, buffer, count) :
476 uinput_setup_device(udev, buffer, count);
477
478 mutex_unlock(&udev->mutex);
479
480 return retval;
481}
482
483static bool uinput_fetch_next_event(struct uinput_device *udev,
484 struct input_event *event)
485{
486 bool have_event;
487
488 spin_lock_irq(&udev->dev->event_lock);
489
490 have_event = udev->head != udev->tail;
491 if (have_event) {
492 *event = udev->buff[udev->tail];
493 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
494 }
495
496 spin_unlock_irq(&udev->dev->event_lock);
497
498 return have_event;
499}
500
501static ssize_t uinput_events_to_user(struct uinput_device *udev,
502 char __user *buffer, size_t count)
503{
504 struct input_event event;
505 size_t read = 0;
506
507 while (read + input_event_size() <= count &&
508 uinput_fetch_next_event(udev, &event)) {
509
510 if (input_event_to_user(buffer + read, &event))
511 return -EFAULT;
512
513 read += input_event_size();
514 }
515
516 return read;
517}
518
519static ssize_t uinput_read(struct file *file, char __user *buffer,
520 size_t count, loff_t *ppos)
521{
522 struct uinput_device *udev = file->private_data;
523 ssize_t retval;
524
525 if (count != 0 && count < input_event_size())
526 return -EINVAL;
527
528 do {
529 retval = mutex_lock_interruptible(&udev->mutex);
530 if (retval)
531 return retval;
532
533 if (udev->state != UIST_CREATED)
534 retval = -ENODEV;
535 else if (udev->head == udev->tail &&
536 (file->f_flags & O_NONBLOCK))
537 retval = -EAGAIN;
538 else
539 retval = uinput_events_to_user(udev, buffer, count);
540
541 mutex_unlock(&udev->mutex);
542
543 if (retval || count == 0)
544 break;
545
546 if (!(file->f_flags & O_NONBLOCK))
547 retval = wait_event_interruptible(udev->waitq,
548 udev->head != udev->tail ||
549 udev->state != UIST_CREATED);
550 } while (retval == 0);
551
552 return retval;
553}
554
555static unsigned int uinput_poll(struct file *file, poll_table *wait)
556{
557 struct uinput_device *udev = file->private_data;
558
559 poll_wait(file, &udev->waitq, wait);
560
561 if (udev->head != udev->tail)
562 return POLLIN | POLLRDNORM;
563
564 return 0;
565}
566
567static int uinput_release(struct inode *inode, struct file *file)
568{
569 struct uinput_device *udev = file->private_data;
570
571 uinput_destroy_device(udev);
572 kfree(udev);
573
574 return 0;
575}
576
577#ifdef CONFIG_COMPAT
578struct uinput_ff_upload_compat {
579 __u32 request_id;
580 __s32 retval;
581 struct ff_effect_compat effect;
582 struct ff_effect_compat old;
583};
584
585static int uinput_ff_upload_to_user(char __user *buffer,
586 const struct uinput_ff_upload *ff_up)
587{
588 if (INPUT_COMPAT_TEST) {
589 struct uinput_ff_upload_compat ff_up_compat;
590
591 ff_up_compat.request_id = ff_up->request_id;
592 ff_up_compat.retval = ff_up->retval;
593 /*
594 * It so happens that the pointer that gives us the trouble
595 * is the last field in the structure. Since we don't support
596 * custom waveforms in uinput anyway we can just copy the whole
597 * thing (to the compat size) and ignore the pointer.
598 */
599 memcpy(&ff_up_compat.effect, &ff_up->effect,
600 sizeof(struct ff_effect_compat));
601 memcpy(&ff_up_compat.old, &ff_up->old,
602 sizeof(struct ff_effect_compat));
603
604 if (copy_to_user(buffer, &ff_up_compat,
605 sizeof(struct uinput_ff_upload_compat)))
606 return -EFAULT;
607 } else {
608 if (copy_to_user(buffer, ff_up,
609 sizeof(struct uinput_ff_upload)))
610 return -EFAULT;
611 }
612
613 return 0;
614}
615
616static int uinput_ff_upload_from_user(const char __user *buffer,
617 struct uinput_ff_upload *ff_up)
618{
619 if (INPUT_COMPAT_TEST) {
620 struct uinput_ff_upload_compat ff_up_compat;
621
622 if (copy_from_user(&ff_up_compat, buffer,
623 sizeof(struct uinput_ff_upload_compat)))
624 return -EFAULT;
625
626 ff_up->request_id = ff_up_compat.request_id;
627 ff_up->retval = ff_up_compat.retval;
628 memcpy(&ff_up->effect, &ff_up_compat.effect,
629 sizeof(struct ff_effect_compat));
630 memcpy(&ff_up->old, &ff_up_compat.old,
631 sizeof(struct ff_effect_compat));
632
633 } else {
634 if (copy_from_user(ff_up, buffer,
635 sizeof(struct uinput_ff_upload)))
636 return -EFAULT;
637 }
638
639 return 0;
640}
641
642#else
643
644static int uinput_ff_upload_to_user(char __user *buffer,
645 const struct uinput_ff_upload *ff_up)
646{
647 if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
648 return -EFAULT;
649
650 return 0;
651}
652
653static int uinput_ff_upload_from_user(const char __user *buffer,
654 struct uinput_ff_upload *ff_up)
655{
656 if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
657 return -EFAULT;
658
659 return 0;
660}
661
662#endif
663
664#define uinput_set_bit(_arg, _bit, _max) \
665({ \
666 int __ret = 0; \
667 if (udev->state == UIST_CREATED) \
668 __ret = -EINVAL; \
669 else if ((_arg) > (_max)) \
670 __ret = -EINVAL; \
671 else set_bit((_arg), udev->dev->_bit); \
672 __ret; \
673})
674
675static int uinput_str_to_user(void __user *dest, const char *str,
676 unsigned int maxlen)
677{
678 char __user *p = dest;
679 int len, ret;
680
681 if (!str)
682 return -ENOENT;
683
684 if (maxlen == 0)
685 return -EINVAL;
686
687 len = strlen(str) + 1;
688 if (len > maxlen)
689 len = maxlen;
690
691 ret = copy_to_user(p, str, len);
692 if (ret)
693 return -EFAULT;
694
695 /* force terminating '\0' */
696 ret = put_user(0, p + len - 1);
697 return ret ? -EFAULT : len;
698}
699
700static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
701 unsigned long arg, void __user *p)
702{
703 int retval;
704 struct uinput_device *udev = file->private_data;
705 struct uinput_ff_upload ff_up;
706 struct uinput_ff_erase ff_erase;
707 struct uinput_request *req;
708 char *phys;
709 const char *name;
710 unsigned int size;
711
712 retval = mutex_lock_interruptible(&udev->mutex);
713 if (retval)
714 return retval;
715
716 if (!udev->dev) {
717 retval = uinput_allocate_device(udev);
718 if (retval)
719 goto out;
720 }
721
722 switch (cmd) {
723 case UI_DEV_CREATE:
724 retval = uinput_create_device(udev);
725 goto out;
726
727 case UI_DEV_DESTROY:
728 uinput_destroy_device(udev);
729 goto out;
730
731 case UI_SET_EVBIT:
732 retval = uinput_set_bit(arg, evbit, EV_MAX);
733 goto out;
734
735 case UI_SET_KEYBIT:
736 retval = uinput_set_bit(arg, keybit, KEY_MAX);
737 goto out;
738
739 case UI_SET_RELBIT:
740 retval = uinput_set_bit(arg, relbit, REL_MAX);
741 goto out;
742
743 case UI_SET_ABSBIT:
744 retval = uinput_set_bit(arg, absbit, ABS_MAX);
745 goto out;
746
747 case UI_SET_MSCBIT:
748 retval = uinput_set_bit(arg, mscbit, MSC_MAX);
749 goto out;
750
751 case UI_SET_LEDBIT:
752 retval = uinput_set_bit(arg, ledbit, LED_MAX);
753 goto out;
754
755 case UI_SET_SNDBIT:
756 retval = uinput_set_bit(arg, sndbit, SND_MAX);
757 goto out;
758
759 case UI_SET_FFBIT:
760 retval = uinput_set_bit(arg, ffbit, FF_MAX);
761 goto out;
762
763 case UI_SET_SWBIT:
764 retval = uinput_set_bit(arg, swbit, SW_MAX);
765 goto out;
766
767 case UI_SET_PROPBIT:
768 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
769 goto out;
770
771 case UI_SET_PHYS:
772 if (udev->state == UIST_CREATED) {
773 retval = -EINVAL;
774 goto out;
775 }
776
777 phys = strndup_user(p, 1024);
778 if (IS_ERR(phys)) {
779 retval = PTR_ERR(phys);
780 goto out;
781 }
782
783 kfree(udev->dev->phys);
784 udev->dev->phys = phys;
785 goto out;
786
787 case UI_BEGIN_FF_UPLOAD:
788 retval = uinput_ff_upload_from_user(p, &ff_up);
789 if (retval)
790 goto out;
791
792 req = uinput_request_find(udev, ff_up.request_id);
793 if (!req || req->code != UI_FF_UPLOAD ||
794 !req->u.upload.effect) {
795 retval = -EINVAL;
796 goto out;
797 }
798
799 ff_up.retval = 0;
800 ff_up.effect = *req->u.upload.effect;
801 if (req->u.upload.old)
802 ff_up.old = *req->u.upload.old;
803 else
804 memset(&ff_up.old, 0, sizeof(struct ff_effect));
805
806 retval = uinput_ff_upload_to_user(p, &ff_up);
807 goto out;
808
809 case UI_BEGIN_FF_ERASE:
810 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
811 retval = -EFAULT;
812 goto out;
813 }
814
815 req = uinput_request_find(udev, ff_erase.request_id);
816 if (!req || req->code != UI_FF_ERASE) {
817 retval = -EINVAL;
818 goto out;
819 }
820
821 ff_erase.retval = 0;
822 ff_erase.effect_id = req->u.effect_id;
823 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
824 retval = -EFAULT;
825 goto out;
826 }
827
828 goto out;
829
830 case UI_END_FF_UPLOAD:
831 retval = uinput_ff_upload_from_user(p, &ff_up);
832 if (retval)
833 goto out;
834
835 req = uinput_request_find(udev, ff_up.request_id);
836 if (!req || req->code != UI_FF_UPLOAD ||
837 !req->u.upload.effect) {
838 retval = -EINVAL;
839 goto out;
840 }
841
842 req->retval = ff_up.retval;
843 uinput_request_done(udev, req);
844 goto out;
845
846 case UI_END_FF_ERASE:
847 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
848 retval = -EFAULT;
849 goto out;
850 }
851
852 req = uinput_request_find(udev, ff_erase.request_id);
853 if (!req || req->code != UI_FF_ERASE) {
854 retval = -EINVAL;
855 goto out;
856 }
857
858 req->retval = ff_erase.retval;
859 uinput_request_done(udev, req);
860 goto out;
861 }
862
863 size = _IOC_SIZE(cmd);
864
865 /* Now check variable-length commands */
866 switch (cmd & ~IOCSIZE_MASK) {
867 case UI_GET_SYSNAME(0):
868 if (udev->state != UIST_CREATED) {
869 retval = -ENOENT;
870 goto out;
871 }
872 name = dev_name(&udev->dev->dev);
873 retval = uinput_str_to_user(p, name, size);
874 goto out;
875 }
876
877 retval = -EINVAL;
878 out:
879 mutex_unlock(&udev->mutex);
880 return retval;
881}
882
883static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
884{
885 return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
886}
887
888#ifdef CONFIG_COMPAT
889static long uinput_compat_ioctl(struct file *file,
890 unsigned int cmd, unsigned long arg)
891{
892 return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
893}
894#endif
895
896static const struct file_operations uinput_fops = {
897 .owner = THIS_MODULE,
898 .open = uinput_open,
899 .release = uinput_release,
900 .read = uinput_read,
901 .write = uinput_write,
902 .poll = uinput_poll,
903 .unlocked_ioctl = uinput_ioctl,
904#ifdef CONFIG_COMPAT
905 .compat_ioctl = uinput_compat_ioctl,
906#endif
907 .llseek = no_llseek,
908};
909
910static struct miscdevice uinput_misc = {
911 .fops = &uinput_fops,
912 .minor = UINPUT_MINOR,
913 .name = UINPUT_NAME,
914};
915MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
916MODULE_ALIAS("devname:" UINPUT_NAME);
917
918static int __init uinput_init(void)
919{
920 return misc_register(&uinput_misc);
921}
922
923static void __exit uinput_exit(void)
924{
925 misc_deregister(&uinput_misc);
926}
927
928MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
929MODULE_DESCRIPTION("User level driver support for input subsystem");
930MODULE_LICENSE("GPL");
931MODULE_VERSION("0.3");
932
933module_init(uinput_init);
934module_exit(uinput_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * User level driver support for input subsystem
4 *
5 * Heavily based on evdev.c by Vojtech Pavlik
6 *
7 * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
8 *
9 * Changes/Revisions:
10 * 0.4 01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
11 * - add UI_GET_SYSNAME ioctl
12 * 0.3 09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
13 * - updated ff support for the changes in kernel interface
14 * - added MODULE_VERSION
15 * 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>)
16 * - added force feedback support
17 * - added UI_SET_PHYS
18 * 0.1 20/06/2002
19 * - first public version
20 */
21#include <uapi/linux/uinput.h>
22#include <linux/poll.h>
23#include <linux/sched.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/fs.h>
28#include <linux/miscdevice.h>
29#include <linux/overflow.h>
30#include <linux/input/mt.h>
31#include "../input-compat.h"
32
33#define UINPUT_NAME "uinput"
34#define UINPUT_BUFFER_SIZE 16
35#define UINPUT_NUM_REQUESTS 16
36#define UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS 10
37
38enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
39
40struct uinput_request {
41 unsigned int id;
42 unsigned int code; /* UI_FF_UPLOAD, UI_FF_ERASE */
43
44 int retval;
45 struct completion done;
46
47 union {
48 unsigned int effect_id;
49 struct {
50 struct ff_effect *effect;
51 struct ff_effect *old;
52 } upload;
53 } u;
54};
55
56struct uinput_device {
57 struct input_dev *dev;
58 struct mutex mutex;
59 enum uinput_state state;
60 wait_queue_head_t waitq;
61 unsigned char ready;
62 unsigned char head;
63 unsigned char tail;
64 struct input_event buff[UINPUT_BUFFER_SIZE];
65 unsigned int ff_effects_max;
66
67 struct uinput_request *requests[UINPUT_NUM_REQUESTS];
68 wait_queue_head_t requests_waitq;
69 spinlock_t requests_lock;
70};
71
72static int uinput_dev_event(struct input_dev *dev,
73 unsigned int type, unsigned int code, int value)
74{
75 struct uinput_device *udev = input_get_drvdata(dev);
76 struct timespec64 ts;
77
78 ktime_get_ts64(&ts);
79
80 udev->buff[udev->head] = (struct input_event) {
81 .input_event_sec = ts.tv_sec,
82 .input_event_usec = ts.tv_nsec / NSEC_PER_USEC,
83 .type = type,
84 .code = code,
85 .value = value,
86 };
87
88 udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
89
90 wake_up_interruptible(&udev->waitq);
91
92 return 0;
93}
94
95/* Atomically allocate an ID for the given request. Returns 0 on success. */
96static bool uinput_request_alloc_id(struct uinput_device *udev,
97 struct uinput_request *request)
98{
99 unsigned int id;
100 bool reserved = false;
101
102 spin_lock(&udev->requests_lock);
103
104 for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
105 if (!udev->requests[id]) {
106 request->id = id;
107 udev->requests[id] = request;
108 reserved = true;
109 break;
110 }
111 }
112
113 spin_unlock(&udev->requests_lock);
114 return reserved;
115}
116
117static struct uinput_request *uinput_request_find(struct uinput_device *udev,
118 unsigned int id)
119{
120 /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
121 if (id >= UINPUT_NUM_REQUESTS)
122 return NULL;
123
124 return udev->requests[id];
125}
126
127static int uinput_request_reserve_slot(struct uinput_device *udev,
128 struct uinput_request *request)
129{
130 /* Allocate slot. If none are available right away, wait. */
131 return wait_event_interruptible(udev->requests_waitq,
132 uinput_request_alloc_id(udev, request));
133}
134
135static void uinput_request_release_slot(struct uinput_device *udev,
136 unsigned int id)
137{
138 /* Mark slot as available */
139 spin_lock(&udev->requests_lock);
140 udev->requests[id] = NULL;
141 spin_unlock(&udev->requests_lock);
142
143 wake_up(&udev->requests_waitq);
144}
145
146static int uinput_request_send(struct uinput_device *udev,
147 struct uinput_request *request)
148{
149 int retval;
150
151 retval = mutex_lock_interruptible(&udev->mutex);
152 if (retval)
153 return retval;
154
155 if (udev->state != UIST_CREATED) {
156 retval = -ENODEV;
157 goto out;
158 }
159
160 init_completion(&request->done);
161
162 /*
163 * Tell our userspace application about this new request
164 * by queueing an input event.
165 */
166 uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
167
168 out:
169 mutex_unlock(&udev->mutex);
170 return retval;
171}
172
173static int uinput_request_submit(struct uinput_device *udev,
174 struct uinput_request *request)
175{
176 int retval;
177
178 retval = uinput_request_reserve_slot(udev, request);
179 if (retval)
180 return retval;
181
182 retval = uinput_request_send(udev, request);
183 if (retval)
184 goto out;
185
186 if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
187 retval = -ETIMEDOUT;
188 goto out;
189 }
190
191 retval = request->retval;
192
193 out:
194 uinput_request_release_slot(udev, request->id);
195 return retval;
196}
197
198/*
199 * Fail all outstanding requests so handlers don't wait for the userspace
200 * to finish processing them.
201 */
202static void uinput_flush_requests(struct uinput_device *udev)
203{
204 struct uinput_request *request;
205 int i;
206
207 spin_lock(&udev->requests_lock);
208
209 for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
210 request = udev->requests[i];
211 if (request) {
212 request->retval = -ENODEV;
213 complete(&request->done);
214 }
215 }
216
217 spin_unlock(&udev->requests_lock);
218}
219
220static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
221{
222 uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
223}
224
225static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
226{
227 uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
228}
229
230static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
231{
232 return uinput_dev_event(dev, EV_FF, effect_id, value);
233}
234
235static int uinput_dev_upload_effect(struct input_dev *dev,
236 struct ff_effect *effect,
237 struct ff_effect *old)
238{
239 struct uinput_device *udev = input_get_drvdata(dev);
240 struct uinput_request request;
241
242 /*
243 * uinput driver does not currently support periodic effects with
244 * custom waveform since it does not have a way to pass buffer of
245 * samples (custom_data) to userspace. If ever there is a device
246 * supporting custom waveforms we would need to define an additional
247 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
248 */
249 if (effect->type == FF_PERIODIC &&
250 effect->u.periodic.waveform == FF_CUSTOM)
251 return -EINVAL;
252
253 request.code = UI_FF_UPLOAD;
254 request.u.upload.effect = effect;
255 request.u.upload.old = old;
256
257 return uinput_request_submit(udev, &request);
258}
259
260static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
261{
262 struct uinput_device *udev = input_get_drvdata(dev);
263 struct uinput_request request;
264
265 if (!test_bit(EV_FF, dev->evbit))
266 return -ENOSYS;
267
268 request.code = UI_FF_ERASE;
269 request.u.effect_id = effect_id;
270
271 return uinput_request_submit(udev, &request);
272}
273
274static int uinput_dev_flush(struct input_dev *dev, struct file *file)
275{
276 /*
277 * If we are called with file == NULL that means we are tearing
278 * down the device, and therefore we can not handle FF erase
279 * requests: either we are handling UI_DEV_DESTROY (and holding
280 * the udev->mutex), or the file descriptor is closed and there is
281 * nobody on the other side anymore.
282 */
283 return file ? input_ff_flush(dev, file) : 0;
284}
285
286static void uinput_destroy_device(struct uinput_device *udev)
287{
288 const char *name, *phys;
289 struct input_dev *dev = udev->dev;
290 enum uinput_state old_state = udev->state;
291
292 udev->state = UIST_NEW_DEVICE;
293
294 if (dev) {
295 name = dev->name;
296 phys = dev->phys;
297 if (old_state == UIST_CREATED) {
298 uinput_flush_requests(udev);
299 input_unregister_device(dev);
300 } else {
301 input_free_device(dev);
302 }
303 kfree(name);
304 kfree(phys);
305 udev->dev = NULL;
306 }
307}
308
309static int uinput_create_device(struct uinput_device *udev)
310{
311 struct input_dev *dev = udev->dev;
312 int error, nslot;
313
314 if (udev->state != UIST_SETUP_COMPLETE) {
315 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
316 return -EINVAL;
317 }
318
319 if (test_bit(EV_ABS, dev->evbit)) {
320 input_alloc_absinfo(dev);
321 if (!dev->absinfo) {
322 error = -EINVAL;
323 goto fail1;
324 }
325
326 if (test_bit(ABS_MT_SLOT, dev->absbit)) {
327 nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
328 error = input_mt_init_slots(dev, nslot, 0);
329 if (error)
330 goto fail1;
331 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
332 input_set_events_per_packet(dev, 60);
333 }
334 }
335
336 if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
337 printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
338 UINPUT_NAME);
339 error = -EINVAL;
340 goto fail1;
341 }
342
343 if (udev->ff_effects_max) {
344 error = input_ff_create(dev, udev->ff_effects_max);
345 if (error)
346 goto fail1;
347
348 dev->ff->upload = uinput_dev_upload_effect;
349 dev->ff->erase = uinput_dev_erase_effect;
350 dev->ff->playback = uinput_dev_playback;
351 dev->ff->set_gain = uinput_dev_set_gain;
352 dev->ff->set_autocenter = uinput_dev_set_autocenter;
353 /*
354 * The standard input_ff_flush() implementation does
355 * not quite work for uinput as we can't reasonably
356 * handle FF requests during device teardown.
357 */
358 dev->flush = uinput_dev_flush;
359 }
360
361 dev->event = uinput_dev_event;
362
363 input_set_drvdata(udev->dev, udev);
364
365 error = input_register_device(udev->dev);
366 if (error)
367 goto fail2;
368
369 udev->state = UIST_CREATED;
370
371 return 0;
372
373 fail2: input_ff_destroy(dev);
374 fail1: uinput_destroy_device(udev);
375 return error;
376}
377
378static int uinput_open(struct inode *inode, struct file *file)
379{
380 struct uinput_device *newdev;
381
382 newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
383 if (!newdev)
384 return -ENOMEM;
385
386 mutex_init(&newdev->mutex);
387 spin_lock_init(&newdev->requests_lock);
388 init_waitqueue_head(&newdev->requests_waitq);
389 init_waitqueue_head(&newdev->waitq);
390 newdev->state = UIST_NEW_DEVICE;
391
392 file->private_data = newdev;
393 stream_open(inode, file);
394
395 return 0;
396}
397
398static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
399 const struct input_absinfo *abs)
400{
401 int min, max, range;
402
403 min = abs->minimum;
404 max = abs->maximum;
405
406 if ((min != 0 || max != 0) && max < min) {
407 printk(KERN_DEBUG
408 "%s: invalid abs[%02x] min:%d max:%d\n",
409 UINPUT_NAME, code, min, max);
410 return -EINVAL;
411 }
412
413 if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
414 printk(KERN_DEBUG
415 "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
416 UINPUT_NAME, code, abs->flat, min, max);
417 return -EINVAL;
418 }
419
420 return 0;
421}
422
423static int uinput_validate_absbits(struct input_dev *dev)
424{
425 unsigned int cnt;
426 int error;
427
428 if (!test_bit(EV_ABS, dev->evbit))
429 return 0;
430
431 /*
432 * Check if absmin/absmax/absfuzz/absflat are sane.
433 */
434
435 for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
436 if (!dev->absinfo)
437 return -EINVAL;
438
439 error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
440 if (error)
441 return error;
442 }
443
444 return 0;
445}
446
447static int uinput_dev_setup(struct uinput_device *udev,
448 struct uinput_setup __user *arg)
449{
450 struct uinput_setup setup;
451 struct input_dev *dev;
452
453 if (udev->state == UIST_CREATED)
454 return -EINVAL;
455
456 if (copy_from_user(&setup, arg, sizeof(setup)))
457 return -EFAULT;
458
459 if (!setup.name[0])
460 return -EINVAL;
461
462 dev = udev->dev;
463 dev->id = setup.id;
464 udev->ff_effects_max = setup.ff_effects_max;
465
466 kfree(dev->name);
467 dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
468 if (!dev->name)
469 return -ENOMEM;
470
471 udev->state = UIST_SETUP_COMPLETE;
472 return 0;
473}
474
475static int uinput_abs_setup(struct uinput_device *udev,
476 struct uinput_setup __user *arg, size_t size)
477{
478 struct uinput_abs_setup setup = {};
479 struct input_dev *dev;
480 int error;
481
482 if (size > sizeof(setup))
483 return -E2BIG;
484
485 if (udev->state == UIST_CREATED)
486 return -EINVAL;
487
488 if (copy_from_user(&setup, arg, size))
489 return -EFAULT;
490
491 if (setup.code > ABS_MAX)
492 return -ERANGE;
493
494 dev = udev->dev;
495
496 error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
497 if (error)
498 return error;
499
500 input_alloc_absinfo(dev);
501 if (!dev->absinfo)
502 return -ENOMEM;
503
504 set_bit(setup.code, dev->absbit);
505 dev->absinfo[setup.code] = setup.absinfo;
506 return 0;
507}
508
509/* legacy setup via write() */
510static int uinput_setup_device_legacy(struct uinput_device *udev,
511 const char __user *buffer, size_t count)
512{
513 struct uinput_user_dev *user_dev;
514 struct input_dev *dev;
515 int i;
516 int retval;
517
518 if (count != sizeof(struct uinput_user_dev))
519 return -EINVAL;
520
521 if (!udev->dev) {
522 udev->dev = input_allocate_device();
523 if (!udev->dev)
524 return -ENOMEM;
525 }
526
527 dev = udev->dev;
528
529 user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
530 if (IS_ERR(user_dev))
531 return PTR_ERR(user_dev);
532
533 udev->ff_effects_max = user_dev->ff_effects_max;
534
535 /* Ensure name is filled in */
536 if (!user_dev->name[0]) {
537 retval = -EINVAL;
538 goto exit;
539 }
540
541 kfree(dev->name);
542 dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
543 GFP_KERNEL);
544 if (!dev->name) {
545 retval = -ENOMEM;
546 goto exit;
547 }
548
549 dev->id.bustype = user_dev->id.bustype;
550 dev->id.vendor = user_dev->id.vendor;
551 dev->id.product = user_dev->id.product;
552 dev->id.version = user_dev->id.version;
553
554 for (i = 0; i < ABS_CNT; i++) {
555 input_abs_set_max(dev, i, user_dev->absmax[i]);
556 input_abs_set_min(dev, i, user_dev->absmin[i]);
557 input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
558 input_abs_set_flat(dev, i, user_dev->absflat[i]);
559 }
560
561 retval = uinput_validate_absbits(dev);
562 if (retval < 0)
563 goto exit;
564
565 udev->state = UIST_SETUP_COMPLETE;
566 retval = count;
567
568 exit:
569 kfree(user_dev);
570 return retval;
571}
572
573/*
574 * Returns true if the given timestamp is valid (i.e., if all the following
575 * conditions are satisfied), false otherwise.
576 * 1) given timestamp is positive
577 * 2) it's within the allowed offset before the current time
578 * 3) it's not in the future
579 */
580static bool is_valid_timestamp(const ktime_t timestamp)
581{
582 ktime_t zero_time;
583 ktime_t current_time;
584 ktime_t min_time;
585 ktime_t offset;
586
587 zero_time = ktime_set(0, 0);
588 if (ktime_compare(zero_time, timestamp) >= 0)
589 return false;
590
591 current_time = ktime_get();
592 offset = ktime_set(UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS, 0);
593 min_time = ktime_sub(current_time, offset);
594
595 if (ktime_after(min_time, timestamp) || ktime_after(timestamp, current_time))
596 return false;
597
598 return true;
599}
600
601static ssize_t uinput_inject_events(struct uinput_device *udev,
602 const char __user *buffer, size_t count)
603{
604 struct input_event ev;
605 size_t bytes = 0;
606 ktime_t timestamp;
607
608 if (count != 0 && count < input_event_size())
609 return -EINVAL;
610
611 while (bytes + input_event_size() <= count) {
612 /*
613 * Note that even if some events were fetched successfully
614 * we are still going to return EFAULT instead of partial
615 * count to let userspace know that it got it's buffers
616 * all wrong.
617 */
618 if (input_event_from_user(buffer + bytes, &ev))
619 return -EFAULT;
620
621 timestamp = ktime_set(ev.input_event_sec, ev.input_event_usec * NSEC_PER_USEC);
622 if (is_valid_timestamp(timestamp))
623 input_set_timestamp(udev->dev, timestamp);
624
625 input_event(udev->dev, ev.type, ev.code, ev.value);
626 bytes += input_event_size();
627 cond_resched();
628 }
629
630 return bytes;
631}
632
633static ssize_t uinput_write(struct file *file, const char __user *buffer,
634 size_t count, loff_t *ppos)
635{
636 struct uinput_device *udev = file->private_data;
637 int retval;
638
639 if (count == 0)
640 return 0;
641
642 retval = mutex_lock_interruptible(&udev->mutex);
643 if (retval)
644 return retval;
645
646 retval = udev->state == UIST_CREATED ?
647 uinput_inject_events(udev, buffer, count) :
648 uinput_setup_device_legacy(udev, buffer, count);
649
650 mutex_unlock(&udev->mutex);
651
652 return retval;
653}
654
655static bool uinput_fetch_next_event(struct uinput_device *udev,
656 struct input_event *event)
657{
658 bool have_event;
659
660 spin_lock_irq(&udev->dev->event_lock);
661
662 have_event = udev->head != udev->tail;
663 if (have_event) {
664 *event = udev->buff[udev->tail];
665 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
666 }
667
668 spin_unlock_irq(&udev->dev->event_lock);
669
670 return have_event;
671}
672
673static ssize_t uinput_events_to_user(struct uinput_device *udev,
674 char __user *buffer, size_t count)
675{
676 struct input_event event;
677 size_t read = 0;
678
679 while (read + input_event_size() <= count &&
680 uinput_fetch_next_event(udev, &event)) {
681
682 if (input_event_to_user(buffer + read, &event))
683 return -EFAULT;
684
685 read += input_event_size();
686 }
687
688 return read;
689}
690
691static ssize_t uinput_read(struct file *file, char __user *buffer,
692 size_t count, loff_t *ppos)
693{
694 struct uinput_device *udev = file->private_data;
695 ssize_t retval;
696
697 if (count != 0 && count < input_event_size())
698 return -EINVAL;
699
700 do {
701 retval = mutex_lock_interruptible(&udev->mutex);
702 if (retval)
703 return retval;
704
705 if (udev->state != UIST_CREATED)
706 retval = -ENODEV;
707 else if (udev->head == udev->tail &&
708 (file->f_flags & O_NONBLOCK))
709 retval = -EAGAIN;
710 else
711 retval = uinput_events_to_user(udev, buffer, count);
712
713 mutex_unlock(&udev->mutex);
714
715 if (retval || count == 0)
716 break;
717
718 if (!(file->f_flags & O_NONBLOCK))
719 retval = wait_event_interruptible(udev->waitq,
720 udev->head != udev->tail ||
721 udev->state != UIST_CREATED);
722 } while (retval == 0);
723
724 return retval;
725}
726
727static __poll_t uinput_poll(struct file *file, poll_table *wait)
728{
729 struct uinput_device *udev = file->private_data;
730 __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* uinput is always writable */
731
732 poll_wait(file, &udev->waitq, wait);
733
734 if (udev->head != udev->tail)
735 mask |= EPOLLIN | EPOLLRDNORM;
736
737 return mask;
738}
739
740static int uinput_release(struct inode *inode, struct file *file)
741{
742 struct uinput_device *udev = file->private_data;
743
744 uinput_destroy_device(udev);
745 kfree(udev);
746
747 return 0;
748}
749
750#ifdef CONFIG_COMPAT
751struct uinput_ff_upload_compat {
752 __u32 request_id;
753 __s32 retval;
754 struct ff_effect_compat effect;
755 struct ff_effect_compat old;
756};
757
758static int uinput_ff_upload_to_user(char __user *buffer,
759 const struct uinput_ff_upload *ff_up)
760{
761 if (in_compat_syscall()) {
762 struct uinput_ff_upload_compat ff_up_compat;
763
764 ff_up_compat.request_id = ff_up->request_id;
765 ff_up_compat.retval = ff_up->retval;
766 /*
767 * It so happens that the pointer that gives us the trouble
768 * is the last field in the structure. Since we don't support
769 * custom waveforms in uinput anyway we can just copy the whole
770 * thing (to the compat size) and ignore the pointer.
771 */
772 memcpy(&ff_up_compat.effect, &ff_up->effect,
773 sizeof(struct ff_effect_compat));
774 memcpy(&ff_up_compat.old, &ff_up->old,
775 sizeof(struct ff_effect_compat));
776
777 if (copy_to_user(buffer, &ff_up_compat,
778 sizeof(struct uinput_ff_upload_compat)))
779 return -EFAULT;
780 } else {
781 if (copy_to_user(buffer, ff_up,
782 sizeof(struct uinput_ff_upload)))
783 return -EFAULT;
784 }
785
786 return 0;
787}
788
789static int uinput_ff_upload_from_user(const char __user *buffer,
790 struct uinput_ff_upload *ff_up)
791{
792 if (in_compat_syscall()) {
793 struct uinput_ff_upload_compat ff_up_compat;
794
795 if (copy_from_user(&ff_up_compat, buffer,
796 sizeof(struct uinput_ff_upload_compat)))
797 return -EFAULT;
798
799 ff_up->request_id = ff_up_compat.request_id;
800 ff_up->retval = ff_up_compat.retval;
801 memcpy(&ff_up->effect, &ff_up_compat.effect,
802 sizeof(struct ff_effect_compat));
803 memcpy(&ff_up->old, &ff_up_compat.old,
804 sizeof(struct ff_effect_compat));
805
806 } else {
807 if (copy_from_user(ff_up, buffer,
808 sizeof(struct uinput_ff_upload)))
809 return -EFAULT;
810 }
811
812 return 0;
813}
814
815#else
816
817static int uinput_ff_upload_to_user(char __user *buffer,
818 const struct uinput_ff_upload *ff_up)
819{
820 if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
821 return -EFAULT;
822
823 return 0;
824}
825
826static int uinput_ff_upload_from_user(const char __user *buffer,
827 struct uinput_ff_upload *ff_up)
828{
829 if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
830 return -EFAULT;
831
832 return 0;
833}
834
835#endif
836
837#define uinput_set_bit(_arg, _bit, _max) \
838({ \
839 int __ret = 0; \
840 if (udev->state == UIST_CREATED) \
841 __ret = -EINVAL; \
842 else if ((_arg) > (_max)) \
843 __ret = -EINVAL; \
844 else set_bit((_arg), udev->dev->_bit); \
845 __ret; \
846})
847
848static int uinput_str_to_user(void __user *dest, const char *str,
849 unsigned int maxlen)
850{
851 char __user *p = dest;
852 int len, ret;
853
854 if (!str)
855 return -ENOENT;
856
857 if (maxlen == 0)
858 return -EINVAL;
859
860 len = strlen(str) + 1;
861 if (len > maxlen)
862 len = maxlen;
863
864 ret = copy_to_user(p, str, len);
865 if (ret)
866 return -EFAULT;
867
868 /* force terminating '\0' */
869 ret = put_user(0, p + len - 1);
870 return ret ? -EFAULT : len;
871}
872
873static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
874 unsigned long arg, void __user *p)
875{
876 int retval;
877 struct uinput_device *udev = file->private_data;
878 struct uinput_ff_upload ff_up;
879 struct uinput_ff_erase ff_erase;
880 struct uinput_request *req;
881 char *phys;
882 const char *name;
883 unsigned int size;
884
885 retval = mutex_lock_interruptible(&udev->mutex);
886 if (retval)
887 return retval;
888
889 if (!udev->dev) {
890 udev->dev = input_allocate_device();
891 if (!udev->dev) {
892 retval = -ENOMEM;
893 goto out;
894 }
895 }
896
897 switch (cmd) {
898 case UI_GET_VERSION:
899 if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
900 retval = -EFAULT;
901 goto out;
902
903 case UI_DEV_CREATE:
904 retval = uinput_create_device(udev);
905 goto out;
906
907 case UI_DEV_DESTROY:
908 uinput_destroy_device(udev);
909 goto out;
910
911 case UI_DEV_SETUP:
912 retval = uinput_dev_setup(udev, p);
913 goto out;
914
915 /* UI_ABS_SETUP is handled in the variable size ioctls */
916
917 case UI_SET_EVBIT:
918 retval = uinput_set_bit(arg, evbit, EV_MAX);
919 goto out;
920
921 case UI_SET_KEYBIT:
922 retval = uinput_set_bit(arg, keybit, KEY_MAX);
923 goto out;
924
925 case UI_SET_RELBIT:
926 retval = uinput_set_bit(arg, relbit, REL_MAX);
927 goto out;
928
929 case UI_SET_ABSBIT:
930 retval = uinput_set_bit(arg, absbit, ABS_MAX);
931 goto out;
932
933 case UI_SET_MSCBIT:
934 retval = uinput_set_bit(arg, mscbit, MSC_MAX);
935 goto out;
936
937 case UI_SET_LEDBIT:
938 retval = uinput_set_bit(arg, ledbit, LED_MAX);
939 goto out;
940
941 case UI_SET_SNDBIT:
942 retval = uinput_set_bit(arg, sndbit, SND_MAX);
943 goto out;
944
945 case UI_SET_FFBIT:
946 retval = uinput_set_bit(arg, ffbit, FF_MAX);
947 goto out;
948
949 case UI_SET_SWBIT:
950 retval = uinput_set_bit(arg, swbit, SW_MAX);
951 goto out;
952
953 case UI_SET_PROPBIT:
954 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
955 goto out;
956
957 case UI_SET_PHYS:
958 if (udev->state == UIST_CREATED) {
959 retval = -EINVAL;
960 goto out;
961 }
962
963 phys = strndup_user(p, 1024);
964 if (IS_ERR(phys)) {
965 retval = PTR_ERR(phys);
966 goto out;
967 }
968
969 kfree(udev->dev->phys);
970 udev->dev->phys = phys;
971 goto out;
972
973 case UI_BEGIN_FF_UPLOAD:
974 retval = uinput_ff_upload_from_user(p, &ff_up);
975 if (retval)
976 goto out;
977
978 req = uinput_request_find(udev, ff_up.request_id);
979 if (!req || req->code != UI_FF_UPLOAD ||
980 !req->u.upload.effect) {
981 retval = -EINVAL;
982 goto out;
983 }
984
985 ff_up.retval = 0;
986 ff_up.effect = *req->u.upload.effect;
987 if (req->u.upload.old)
988 ff_up.old = *req->u.upload.old;
989 else
990 memset(&ff_up.old, 0, sizeof(struct ff_effect));
991
992 retval = uinput_ff_upload_to_user(p, &ff_up);
993 goto out;
994
995 case UI_BEGIN_FF_ERASE:
996 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
997 retval = -EFAULT;
998 goto out;
999 }
1000
1001 req = uinput_request_find(udev, ff_erase.request_id);
1002 if (!req || req->code != UI_FF_ERASE) {
1003 retval = -EINVAL;
1004 goto out;
1005 }
1006
1007 ff_erase.retval = 0;
1008 ff_erase.effect_id = req->u.effect_id;
1009 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
1010 retval = -EFAULT;
1011 goto out;
1012 }
1013
1014 goto out;
1015
1016 case UI_END_FF_UPLOAD:
1017 retval = uinput_ff_upload_from_user(p, &ff_up);
1018 if (retval)
1019 goto out;
1020
1021 req = uinput_request_find(udev, ff_up.request_id);
1022 if (!req || req->code != UI_FF_UPLOAD ||
1023 !req->u.upload.effect) {
1024 retval = -EINVAL;
1025 goto out;
1026 }
1027
1028 req->retval = ff_up.retval;
1029 complete(&req->done);
1030 goto out;
1031
1032 case UI_END_FF_ERASE:
1033 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
1034 retval = -EFAULT;
1035 goto out;
1036 }
1037
1038 req = uinput_request_find(udev, ff_erase.request_id);
1039 if (!req || req->code != UI_FF_ERASE) {
1040 retval = -EINVAL;
1041 goto out;
1042 }
1043
1044 req->retval = ff_erase.retval;
1045 complete(&req->done);
1046 goto out;
1047 }
1048
1049 size = _IOC_SIZE(cmd);
1050
1051 /* Now check variable-length commands */
1052 switch (cmd & ~IOCSIZE_MASK) {
1053 case UI_GET_SYSNAME(0):
1054 if (udev->state != UIST_CREATED) {
1055 retval = -ENOENT;
1056 goto out;
1057 }
1058 name = dev_name(&udev->dev->dev);
1059 retval = uinput_str_to_user(p, name, size);
1060 goto out;
1061
1062 case UI_ABS_SETUP & ~IOCSIZE_MASK:
1063 retval = uinput_abs_setup(udev, p, size);
1064 goto out;
1065 }
1066
1067 retval = -EINVAL;
1068 out:
1069 mutex_unlock(&udev->mutex);
1070 return retval;
1071}
1072
1073static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1074{
1075 return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
1076}
1077
1078#ifdef CONFIG_COMPAT
1079
1080/*
1081 * These IOCTLs change their size and thus their numbers between
1082 * 32 and 64 bits.
1083 */
1084#define UI_SET_PHYS_COMPAT \
1085 _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
1086#define UI_BEGIN_FF_UPLOAD_COMPAT \
1087 _IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload_compat)
1088#define UI_END_FF_UPLOAD_COMPAT \
1089 _IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload_compat)
1090
1091static long uinput_compat_ioctl(struct file *file,
1092 unsigned int cmd, unsigned long arg)
1093{
1094 switch (cmd) {
1095 case UI_SET_PHYS_COMPAT:
1096 cmd = UI_SET_PHYS;
1097 break;
1098 case UI_BEGIN_FF_UPLOAD_COMPAT:
1099 cmd = UI_BEGIN_FF_UPLOAD;
1100 break;
1101 case UI_END_FF_UPLOAD_COMPAT:
1102 cmd = UI_END_FF_UPLOAD;
1103 break;
1104 }
1105
1106 return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
1107}
1108#endif
1109
1110static const struct file_operations uinput_fops = {
1111 .owner = THIS_MODULE,
1112 .open = uinput_open,
1113 .release = uinput_release,
1114 .read = uinput_read,
1115 .write = uinput_write,
1116 .poll = uinput_poll,
1117 .unlocked_ioctl = uinput_ioctl,
1118#ifdef CONFIG_COMPAT
1119 .compat_ioctl = uinput_compat_ioctl,
1120#endif
1121 .llseek = no_llseek,
1122};
1123
1124static struct miscdevice uinput_misc = {
1125 .fops = &uinput_fops,
1126 .minor = UINPUT_MINOR,
1127 .name = UINPUT_NAME,
1128};
1129module_misc_device(uinput_misc);
1130
1131MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
1132MODULE_ALIAS("devname:" UINPUT_NAME);
1133
1134MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
1135MODULE_DESCRIPTION("User level driver support for input subsystem");
1136MODULE_LICENSE("GPL");