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