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