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: &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(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(lock: &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(lock: &udev->requests_lock);
140 udev->requests[id] = NULL;
141 spin_unlock(lock: &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(x: &request->done);
161
162 /*
163 * Tell our userspace application about this new request
164 * by queueing an input event.
165 */
166 uinput_dev_event(dev: udev->dev, EV_UINPUT, code: request->code, value: request->id);
167
168 out:
169 mutex_unlock(lock: &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(x: &request->done, timeout: 30 * HZ)) {
187 retval = -ETIMEDOUT;
188 goto out;
189 }
190
191 retval = request->retval;
192
193 out:
194 uinput_request_release_slot(udev, id: 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(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(lock: &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, value: 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, value: 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, code: 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: &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: &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(objp: name);
304 kfree(objp: 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, num_slots: nslot, flags: 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, n_events: 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, max_effects: 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(dev: udev->dev, data: 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(size: 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, filp: 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, code: cnt, abs: &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(to: &setup, from: arg, n: 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(objp: dev->name);
467 dev->name = kstrndup(s: 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(to: &setup, from: arg, n: 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, code: setup.code, abs: &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(nr: setup.code, addr: 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(ptr: user_dev))
531 return PTR_ERR(ptr: 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(objp: dev->name);
542 dev->name = kstrndup(s: 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, axis: i, val: user_dev->absmax[i]);
556 input_abs_set_min(dev, axis: i, val: user_dev->absmin[i]);
557 input_abs_set_fuzz(dev, axis: i, val: user_dev->absfuzz[i]);
558 input_abs_set_flat(dev, axis: i, val: 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(objp: 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(secs: 0, nsecs: 0);
588 if (ktime_compare(cmp1: zero_time, cmp2: timestamp) >= 0)
589 return false;
590
591 current_time = ktime_get();
592 offset = ktime_set(UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS, nsecs: 0);
593 min_time = ktime_sub(current_time, offset);
594
595 if (ktime_after(cmp1: min_time, cmp2: timestamp) || ktime_after(cmp1: timestamp, cmp2: 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: buffer + bytes, event: &ev))
619 return -EFAULT;
620
621 timestamp = ktime_set(secs: ev.input_event_sec, nsecs: ev.input_event_usec * NSEC_PER_USEC);
622 if (is_valid_timestamp(timestamp))
623 input_set_timestamp(dev: udev->dev, timestamp);
624
625 input_event(dev: udev->dev, type: ev.type, code: ev.code, value: 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(lock: &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(lock: &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(lock: &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: &event)) {
681
682 if (input_event_to_user(buffer: buffer + read, event: &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(lock: &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(filp: file, wait_address: &udev->waitq, p: 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(objp: 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(to: buffer, from: &ff_up_compat,
778 n: sizeof(struct uinput_ff_upload_compat)))
779 return -EFAULT;
780 } else {
781 if (copy_to_user(to: buffer, from: ff_up,
782 n: 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(to: &ff_up_compat, from: buffer,
796 n: 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(to: ff_up, from: buffer,
808 n: 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(to: p, from: str, n: 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, arg: 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(ptr: phys)) {
965 retval = PTR_ERR(ptr: phys);
966 goto out;
967 }
968
969 kfree(objp: 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(buffer: p, ff_up: &ff_up);
975 if (retval)
976 goto out;
977
978 req = uinput_request_find(udev, id: 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(buffer: p, ff_up: &ff_up);
993 goto out;
994
995 case UI_BEGIN_FF_ERASE:
996 if (copy_from_user(to: &ff_erase, from: p, n: sizeof(ff_erase))) {
997 retval = -EFAULT;
998 goto out;
999 }
1000
1001 req = uinput_request_find(udev, id: 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(to: p, from: &ff_erase, n: 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(buffer: p, ff_up: &ff_up);
1018 if (retval)
1019 goto out;
1020
1021 req = uinput_request_find(udev, id: 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(to: &ff_erase, from: p, n: sizeof(ff_erase))) {
1034 retval = -EFAULT;
1035 goto out;
1036 }
1037
1038 req = uinput_request_find(udev, id: 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(dev: &udev->dev->dev);
1059 retval = uinput_str_to_user(dest: p, str: name, maxlen: size);
1060 goto out;
1061
1062 case UI_ABS_SETUP & ~IOCSIZE_MASK:
1063 retval = uinput_abs_setup(udev, arg: p, size);
1064 goto out;
1065 }
1066
1067 retval = -EINVAL;
1068 out:
1069 mutex_unlock(lock: &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, p: (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, p: compat_ptr(uptr: 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");
1137

source code of linux/drivers/input/misc/uinput.c