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