xref: /linux/drivers/input/misc/uinput.c (revision bf070bb0e6c62ba3075db0a666763ba52c677102)
1 /*
2  *  User level driver support for input subsystem
3  *
4  * Heavily based on evdev.c by Vojtech Pavlik
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  *
20  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
21  *
22  * Changes/Revisions:
23  *	0.4	01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
24  *		- add UI_GET_SYSNAME ioctl
25  *	0.3	09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
26  *		- updated ff support for the changes in kernel interface
27  *		- added MODULE_VERSION
28  *	0.2	16/10/2004 (Micah Dowty <micah@navi.cx>)
29  *		- added force feedback support
30  *              - added UI_SET_PHYS
31  *	0.1	20/06/2002
32  *		- first public version
33  */
34 #include <uapi/linux/uinput.h>
35 #include <linux/poll.h>
36 #include <linux/sched.h>
37 #include <linux/slab.h>
38 #include <linux/module.h>
39 #include <linux/init.h>
40 #include <linux/fs.h>
41 #include <linux/miscdevice.h>
42 #include <linux/input/mt.h>
43 #include "../input-compat.h"
44 
45 #define UINPUT_NAME		"uinput"
46 #define UINPUT_BUFFER_SIZE	16
47 #define UINPUT_NUM_REQUESTS	16
48 
49 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
50 
51 struct uinput_request {
52 	unsigned int		id;
53 	unsigned int		code;	/* UI_FF_UPLOAD, UI_FF_ERASE */
54 
55 	int			retval;
56 	struct completion	done;
57 
58 	union {
59 		unsigned int	effect_id;
60 		struct {
61 			struct ff_effect *effect;
62 			struct ff_effect *old;
63 		} upload;
64 	} u;
65 };
66 
67 struct uinput_device {
68 	struct input_dev	*dev;
69 	struct mutex		mutex;
70 	enum uinput_state	state;
71 	wait_queue_head_t	waitq;
72 	unsigned char		ready;
73 	unsigned char		head;
74 	unsigned char		tail;
75 	struct input_event	buff[UINPUT_BUFFER_SIZE];
76 	unsigned int		ff_effects_max;
77 
78 	struct uinput_request	*requests[UINPUT_NUM_REQUESTS];
79 	wait_queue_head_t	requests_waitq;
80 	spinlock_t		requests_lock;
81 };
82 
83 static int uinput_dev_event(struct input_dev *dev,
84 			    unsigned int type, unsigned int code, int value)
85 {
86 	struct uinput_device	*udev = input_get_drvdata(dev);
87 
88 	udev->buff[udev->head].type = type;
89 	udev->buff[udev->head].code = code;
90 	udev->buff[udev->head].value = value;
91 	do_gettimeofday(&udev->buff[udev->head].time);
92 	udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
93 
94 	wake_up_interruptible(&udev->waitq);
95 
96 	return 0;
97 }
98 
99 /* Atomically allocate an ID for the given request. Returns 0 on success. */
100 static bool uinput_request_alloc_id(struct uinput_device *udev,
101 				    struct uinput_request *request)
102 {
103 	unsigned int id;
104 	bool reserved = false;
105 
106 	spin_lock(&udev->requests_lock);
107 
108 	for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
109 		if (!udev->requests[id]) {
110 			request->id = id;
111 			udev->requests[id] = request;
112 			reserved = true;
113 			break;
114 		}
115 	}
116 
117 	spin_unlock(&udev->requests_lock);
118 	return reserved;
119 }
120 
121 static struct uinput_request *uinput_request_find(struct uinput_device *udev,
122 						  unsigned int id)
123 {
124 	/* Find an input request, by ID. Returns NULL if the ID isn't valid. */
125 	if (id >= UINPUT_NUM_REQUESTS)
126 		return NULL;
127 
128 	return udev->requests[id];
129 }
130 
131 static int uinput_request_reserve_slot(struct uinput_device *udev,
132 				       struct uinput_request *request)
133 {
134 	/* Allocate slot. If none are available right away, wait. */
135 	return wait_event_interruptible(udev->requests_waitq,
136 					uinput_request_alloc_id(udev, request));
137 }
138 
139 static void uinput_request_release_slot(struct uinput_device *udev,
140 					unsigned int id)
141 {
142 	/* Mark slot as available */
143 	spin_lock(&udev->requests_lock);
144 	udev->requests[id] = NULL;
145 	spin_unlock(&udev->requests_lock);
146 
147 	wake_up(&udev->requests_waitq);
148 }
149 
150 static int uinput_request_send(struct uinput_device *udev,
151 			       struct uinput_request *request)
152 {
153 	int retval;
154 
155 	retval = mutex_lock_interruptible(&udev->mutex);
156 	if (retval)
157 		return retval;
158 
159 	if (udev->state != UIST_CREATED) {
160 		retval = -ENODEV;
161 		goto out;
162 	}
163 
164 	init_completion(&request->done);
165 
166 	/*
167 	 * Tell our userspace application about this new request
168 	 * by queueing an input event.
169 	 */
170 	uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
171 
172  out:
173 	mutex_unlock(&udev->mutex);
174 	return retval;
175 }
176 
177 static int uinput_request_submit(struct uinput_device *udev,
178 				 struct uinput_request *request)
179 {
180 	int retval;
181 
182 	retval = uinput_request_reserve_slot(udev, request);
183 	if (retval)
184 		return retval;
185 
186 	retval = uinput_request_send(udev, request);
187 	if (retval)
188 		goto out;
189 
190 	if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
191 		retval = -ETIMEDOUT;
192 		goto out;
193 	}
194 
195 	retval = request->retval;
196 
197  out:
198 	uinput_request_release_slot(udev, request->id);
199 	return retval;
200 }
201 
202 /*
203  * Fail all outstanding requests so handlers don't wait for the userspace
204  * to finish processing them.
205  */
206 static void uinput_flush_requests(struct uinput_device *udev)
207 {
208 	struct uinput_request *request;
209 	int i;
210 
211 	spin_lock(&udev->requests_lock);
212 
213 	for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
214 		request = udev->requests[i];
215 		if (request) {
216 			request->retval = -ENODEV;
217 			complete(&request->done);
218 		}
219 	}
220 
221 	spin_unlock(&udev->requests_lock);
222 }
223 
224 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
225 {
226 	uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
227 }
228 
229 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
230 {
231 	uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
232 }
233 
234 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
235 {
236 	return uinput_dev_event(dev, EV_FF, effect_id, value);
237 }
238 
239 static int uinput_dev_upload_effect(struct input_dev *dev,
240 				    struct ff_effect *effect,
241 				    struct ff_effect *old)
242 {
243 	struct uinput_device *udev = input_get_drvdata(dev);
244 	struct uinput_request request;
245 
246 	/*
247 	 * uinput driver does not currently support periodic effects with
248 	 * custom waveform since it does not have a way to pass buffer of
249 	 * samples (custom_data) to userspace. If ever there is a device
250 	 * supporting custom waveforms we would need to define an additional
251 	 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
252 	 */
253 	if (effect->type == FF_PERIODIC &&
254 			effect->u.periodic.waveform == FF_CUSTOM)
255 		return -EINVAL;
256 
257 	request.code = UI_FF_UPLOAD;
258 	request.u.upload.effect = effect;
259 	request.u.upload.old = old;
260 
261 	return uinput_request_submit(udev, &request);
262 }
263 
264 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
265 {
266 	struct uinput_device *udev = input_get_drvdata(dev);
267 	struct uinput_request request;
268 
269 	if (!test_bit(EV_FF, dev->evbit))
270 		return -ENOSYS;
271 
272 	request.code = UI_FF_ERASE;
273 	request.u.effect_id = effect_id;
274 
275 	return uinput_request_submit(udev, &request);
276 }
277 
278 static int uinput_dev_flush(struct input_dev *dev, struct file *file)
279 {
280 	/*
281 	 * If we are called with file == NULL that means we are tearing
282 	 * down the device, and therefore we can not handle FF erase
283 	 * requests: either we are handling UI_DEV_DESTROY (and holding
284 	 * the udev->mutex), or the file descriptor is closed and there is
285 	 * nobody on the other side anymore.
286 	 */
287 	return file ? input_ff_flush(dev, file) : 0;
288 }
289 
290 static void uinput_destroy_device(struct uinput_device *udev)
291 {
292 	const char *name, *phys;
293 	struct input_dev *dev = udev->dev;
294 	enum uinput_state old_state = udev->state;
295 
296 	udev->state = UIST_NEW_DEVICE;
297 
298 	if (dev) {
299 		name = dev->name;
300 		phys = dev->phys;
301 		if (old_state == UIST_CREATED) {
302 			uinput_flush_requests(udev);
303 			input_unregister_device(dev);
304 		} else {
305 			input_free_device(dev);
306 		}
307 		kfree(name);
308 		kfree(phys);
309 		udev->dev = NULL;
310 	}
311 }
312 
313 static int uinput_create_device(struct uinput_device *udev)
314 {
315 	struct input_dev *dev = udev->dev;
316 	int error, nslot;
317 
318 	if (udev->state != UIST_SETUP_COMPLETE) {
319 		printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
320 		return -EINVAL;
321 	}
322 
323 	if (test_bit(EV_ABS, dev->evbit)) {
324 		input_alloc_absinfo(dev);
325 		if (!dev->absinfo) {
326 			error = -EINVAL;
327 			goto fail1;
328 		}
329 
330 		if (test_bit(ABS_MT_SLOT, dev->absbit)) {
331 			nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
332 			error = input_mt_init_slots(dev, nslot, 0);
333 			if (error)
334 				goto fail1;
335 		} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
336 			input_set_events_per_packet(dev, 60);
337 		}
338 	}
339 
340 	if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
341 		printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
342 			UINPUT_NAME);
343 		error = -EINVAL;
344 		goto fail1;
345 	}
346 
347 	if (udev->ff_effects_max) {
348 		error = input_ff_create(dev, udev->ff_effects_max);
349 		if (error)
350 			goto fail1;
351 
352 		dev->ff->upload = uinput_dev_upload_effect;
353 		dev->ff->erase = uinput_dev_erase_effect;
354 		dev->ff->playback = uinput_dev_playback;
355 		dev->ff->set_gain = uinput_dev_set_gain;
356 		dev->ff->set_autocenter = uinput_dev_set_autocenter;
357 		/*
358 		 * The standard input_ff_flush() implementation does
359 		 * not quite work for uinput as we can't reasonably
360 		 * handle FF requests during device teardown.
361 		 */
362 		dev->flush = uinput_dev_flush;
363 	}
364 
365 	dev->event = uinput_dev_event;
366 
367 	input_set_drvdata(udev->dev, udev);
368 
369 	error = input_register_device(udev->dev);
370 	if (error)
371 		goto fail2;
372 
373 	udev->state = UIST_CREATED;
374 
375 	return 0;
376 
377  fail2:	input_ff_destroy(dev);
378  fail1: uinput_destroy_device(udev);
379 	return error;
380 }
381 
382 static int uinput_open(struct inode *inode, struct file *file)
383 {
384 	struct uinput_device *newdev;
385 
386 	newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
387 	if (!newdev)
388 		return -ENOMEM;
389 
390 	mutex_init(&newdev->mutex);
391 	spin_lock_init(&newdev->requests_lock);
392 	init_waitqueue_head(&newdev->requests_waitq);
393 	init_waitqueue_head(&newdev->waitq);
394 	newdev->state = UIST_NEW_DEVICE;
395 
396 	file->private_data = newdev;
397 	nonseekable_open(inode, file);
398 
399 	return 0;
400 }
401 
402 static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
403 				   const struct input_absinfo *abs)
404 {
405 	int min, max;
406 
407 	min = abs->minimum;
408 	max = abs->maximum;
409 
410 	if ((min != 0 || max != 0) && max <= min) {
411 		printk(KERN_DEBUG
412 		       "%s: invalid abs[%02x] min:%d max:%d\n",
413 		       UINPUT_NAME, code, min, max);
414 		return -EINVAL;
415 	}
416 
417 	if (abs->flat > max - min) {
418 		printk(KERN_DEBUG
419 		       "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
420 		       UINPUT_NAME, code, abs->flat, min, max);
421 		return -EINVAL;
422 	}
423 
424 	return 0;
425 }
426 
427 static int uinput_validate_absbits(struct input_dev *dev)
428 {
429 	unsigned int cnt;
430 	int error;
431 
432 	if (!test_bit(EV_ABS, dev->evbit))
433 		return 0;
434 
435 	/*
436 	 * Check if absmin/absmax/absfuzz/absflat are sane.
437 	 */
438 
439 	for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
440 		if (!dev->absinfo)
441 			return -EINVAL;
442 
443 		error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
444 		if (error)
445 			return error;
446 	}
447 
448 	return 0;
449 }
450 
451 static int uinput_dev_setup(struct uinput_device *udev,
452 			    struct uinput_setup __user *arg)
453 {
454 	struct uinput_setup setup;
455 	struct input_dev *dev;
456 
457 	if (udev->state == UIST_CREATED)
458 		return -EINVAL;
459 
460 	if (copy_from_user(&setup, arg, sizeof(setup)))
461 		return -EFAULT;
462 
463 	if (!setup.name[0])
464 		return -EINVAL;
465 
466 	dev = udev->dev;
467 	dev->id = setup.id;
468 	udev->ff_effects_max = setup.ff_effects_max;
469 
470 	kfree(dev->name);
471 	dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
472 	if (!dev->name)
473 		return -ENOMEM;
474 
475 	udev->state = UIST_SETUP_COMPLETE;
476 	return 0;
477 }
478 
479 static int uinput_abs_setup(struct uinput_device *udev,
480 			    struct uinput_setup __user *arg, size_t size)
481 {
482 	struct uinput_abs_setup setup = {};
483 	struct input_dev *dev;
484 	int error;
485 
486 	if (size > sizeof(setup))
487 		return -E2BIG;
488 
489 	if (udev->state == UIST_CREATED)
490 		return -EINVAL;
491 
492 	if (copy_from_user(&setup, arg, size))
493 		return -EFAULT;
494 
495 	if (setup.code > ABS_MAX)
496 		return -ERANGE;
497 
498 	dev = udev->dev;
499 
500 	error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
501 	if (error)
502 		return error;
503 
504 	input_alloc_absinfo(dev);
505 	if (!dev->absinfo)
506 		return -ENOMEM;
507 
508 	set_bit(setup.code, dev->absbit);
509 	dev->absinfo[setup.code] = setup.absinfo;
510 	return 0;
511 }
512 
513 /* legacy setup via write() */
514 static int uinput_setup_device_legacy(struct uinput_device *udev,
515 				      const char __user *buffer, size_t count)
516 {
517 	struct uinput_user_dev	*user_dev;
518 	struct input_dev	*dev;
519 	int			i;
520 	int			retval;
521 
522 	if (count != sizeof(struct uinput_user_dev))
523 		return -EINVAL;
524 
525 	if (!udev->dev) {
526 		udev->dev = input_allocate_device();
527 		if (!udev->dev)
528 			return -ENOMEM;
529 	}
530 
531 	dev = udev->dev;
532 
533 	user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
534 	if (IS_ERR(user_dev))
535 		return PTR_ERR(user_dev);
536 
537 	udev->ff_effects_max = user_dev->ff_effects_max;
538 
539 	/* Ensure name is filled in */
540 	if (!user_dev->name[0]) {
541 		retval = -EINVAL;
542 		goto exit;
543 	}
544 
545 	kfree(dev->name);
546 	dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
547 			     GFP_KERNEL);
548 	if (!dev->name) {
549 		retval = -ENOMEM;
550 		goto exit;
551 	}
552 
553 	dev->id.bustype	= user_dev->id.bustype;
554 	dev->id.vendor	= user_dev->id.vendor;
555 	dev->id.product	= user_dev->id.product;
556 	dev->id.version	= user_dev->id.version;
557 
558 	for (i = 0; i < ABS_CNT; i++) {
559 		input_abs_set_max(dev, i, user_dev->absmax[i]);
560 		input_abs_set_min(dev, i, user_dev->absmin[i]);
561 		input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
562 		input_abs_set_flat(dev, i, user_dev->absflat[i]);
563 	}
564 
565 	retval = uinput_validate_absbits(dev);
566 	if (retval < 0)
567 		goto exit;
568 
569 	udev->state = UIST_SETUP_COMPLETE;
570 	retval = count;
571 
572  exit:
573 	kfree(user_dev);
574 	return retval;
575 }
576 
577 static ssize_t uinput_inject_events(struct uinput_device *udev,
578 				    const char __user *buffer, size_t count)
579 {
580 	struct input_event ev;
581 	size_t bytes = 0;
582 
583 	if (count != 0 && count < input_event_size())
584 		return -EINVAL;
585 
586 	while (bytes + input_event_size() <= count) {
587 		/*
588 		 * Note that even if some events were fetched successfully
589 		 * we are still going to return EFAULT instead of partial
590 		 * count to let userspace know that it got it's buffers
591 		 * all wrong.
592 		 */
593 		if (input_event_from_user(buffer + bytes, &ev))
594 			return -EFAULT;
595 
596 		input_event(udev->dev, ev.type, ev.code, ev.value);
597 		bytes += input_event_size();
598 	}
599 
600 	return bytes;
601 }
602 
603 static ssize_t uinput_write(struct file *file, const char __user *buffer,
604 			    size_t count, loff_t *ppos)
605 {
606 	struct uinput_device *udev = file->private_data;
607 	int retval;
608 
609 	if (count == 0)
610 		return 0;
611 
612 	retval = mutex_lock_interruptible(&udev->mutex);
613 	if (retval)
614 		return retval;
615 
616 	retval = udev->state == UIST_CREATED ?
617 			uinput_inject_events(udev, buffer, count) :
618 			uinput_setup_device_legacy(udev, buffer, count);
619 
620 	mutex_unlock(&udev->mutex);
621 
622 	return retval;
623 }
624 
625 static bool uinput_fetch_next_event(struct uinput_device *udev,
626 				    struct input_event *event)
627 {
628 	bool have_event;
629 
630 	spin_lock_irq(&udev->dev->event_lock);
631 
632 	have_event = udev->head != udev->tail;
633 	if (have_event) {
634 		*event = udev->buff[udev->tail];
635 		udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
636 	}
637 
638 	spin_unlock_irq(&udev->dev->event_lock);
639 
640 	return have_event;
641 }
642 
643 static ssize_t uinput_events_to_user(struct uinput_device *udev,
644 				     char __user *buffer, size_t count)
645 {
646 	struct input_event event;
647 	size_t read = 0;
648 
649 	while (read + input_event_size() <= count &&
650 	       uinput_fetch_next_event(udev, &event)) {
651 
652 		if (input_event_to_user(buffer + read, &event))
653 			return -EFAULT;
654 
655 		read += input_event_size();
656 	}
657 
658 	return read;
659 }
660 
661 static ssize_t uinput_read(struct file *file, char __user *buffer,
662 			   size_t count, loff_t *ppos)
663 {
664 	struct uinput_device *udev = file->private_data;
665 	ssize_t retval;
666 
667 	if (count != 0 && count < input_event_size())
668 		return -EINVAL;
669 
670 	do {
671 		retval = mutex_lock_interruptible(&udev->mutex);
672 		if (retval)
673 			return retval;
674 
675 		if (udev->state != UIST_CREATED)
676 			retval = -ENODEV;
677 		else if (udev->head == udev->tail &&
678 			 (file->f_flags & O_NONBLOCK))
679 			retval = -EAGAIN;
680 		else
681 			retval = uinput_events_to_user(udev, buffer, count);
682 
683 		mutex_unlock(&udev->mutex);
684 
685 		if (retval || count == 0)
686 			break;
687 
688 		if (!(file->f_flags & O_NONBLOCK))
689 			retval = wait_event_interruptible(udev->waitq,
690 						  udev->head != udev->tail ||
691 						  udev->state != UIST_CREATED);
692 	} while (retval == 0);
693 
694 	return retval;
695 }
696 
697 static unsigned int uinput_poll(struct file *file, poll_table *wait)
698 {
699 	struct uinput_device *udev = file->private_data;
700 
701 	poll_wait(file, &udev->waitq, wait);
702 
703 	if (udev->head != udev->tail)
704 		return POLLIN | POLLRDNORM;
705 
706 	return 0;
707 }
708 
709 static int uinput_release(struct inode *inode, struct file *file)
710 {
711 	struct uinput_device *udev = file->private_data;
712 
713 	uinput_destroy_device(udev);
714 	kfree(udev);
715 
716 	return 0;
717 }
718 
719 #ifdef CONFIG_COMPAT
720 struct uinput_ff_upload_compat {
721 	__u32			request_id;
722 	__s32			retval;
723 	struct ff_effect_compat	effect;
724 	struct ff_effect_compat	old;
725 };
726 
727 static int uinput_ff_upload_to_user(char __user *buffer,
728 				    const struct uinput_ff_upload *ff_up)
729 {
730 	if (in_compat_syscall()) {
731 		struct uinput_ff_upload_compat ff_up_compat;
732 
733 		ff_up_compat.request_id = ff_up->request_id;
734 		ff_up_compat.retval = ff_up->retval;
735 		/*
736 		 * It so happens that the pointer that gives us the trouble
737 		 * is the last field in the structure. Since we don't support
738 		 * custom waveforms in uinput anyway we can just copy the whole
739 		 * thing (to the compat size) and ignore the pointer.
740 		 */
741 		memcpy(&ff_up_compat.effect, &ff_up->effect,
742 			sizeof(struct ff_effect_compat));
743 		memcpy(&ff_up_compat.old, &ff_up->old,
744 			sizeof(struct ff_effect_compat));
745 
746 		if (copy_to_user(buffer, &ff_up_compat,
747 				 sizeof(struct uinput_ff_upload_compat)))
748 			return -EFAULT;
749 	} else {
750 		if (copy_to_user(buffer, ff_up,
751 				 sizeof(struct uinput_ff_upload)))
752 			return -EFAULT;
753 	}
754 
755 	return 0;
756 }
757 
758 static int uinput_ff_upload_from_user(const char __user *buffer,
759 				      struct uinput_ff_upload *ff_up)
760 {
761 	if (in_compat_syscall()) {
762 		struct uinput_ff_upload_compat ff_up_compat;
763 
764 		if (copy_from_user(&ff_up_compat, buffer,
765 				   sizeof(struct uinput_ff_upload_compat)))
766 			return -EFAULT;
767 
768 		ff_up->request_id = ff_up_compat.request_id;
769 		ff_up->retval = ff_up_compat.retval;
770 		memcpy(&ff_up->effect, &ff_up_compat.effect,
771 			sizeof(struct ff_effect_compat));
772 		memcpy(&ff_up->old, &ff_up_compat.old,
773 			sizeof(struct ff_effect_compat));
774 
775 	} else {
776 		if (copy_from_user(ff_up, buffer,
777 				   sizeof(struct uinput_ff_upload)))
778 			return -EFAULT;
779 	}
780 
781 	return 0;
782 }
783 
784 #else
785 
786 static int uinput_ff_upload_to_user(char __user *buffer,
787 				    const struct uinput_ff_upload *ff_up)
788 {
789 	if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
790 		return -EFAULT;
791 
792 	return 0;
793 }
794 
795 static int uinput_ff_upload_from_user(const char __user *buffer,
796 				      struct uinput_ff_upload *ff_up)
797 {
798 	if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
799 		return -EFAULT;
800 
801 	return 0;
802 }
803 
804 #endif
805 
806 #define uinput_set_bit(_arg, _bit, _max)		\
807 ({							\
808 	int __ret = 0;					\
809 	if (udev->state == UIST_CREATED)		\
810 		__ret =  -EINVAL;			\
811 	else if ((_arg) > (_max))			\
812 		__ret = -EINVAL;			\
813 	else set_bit((_arg), udev->dev->_bit);		\
814 	__ret;						\
815 })
816 
817 static int uinput_str_to_user(void __user *dest, const char *str,
818 			      unsigned int maxlen)
819 {
820 	char __user *p = dest;
821 	int len, ret;
822 
823 	if (!str)
824 		return -ENOENT;
825 
826 	if (maxlen == 0)
827 		return -EINVAL;
828 
829 	len = strlen(str) + 1;
830 	if (len > maxlen)
831 		len = maxlen;
832 
833 	ret = copy_to_user(p, str, len);
834 	if (ret)
835 		return -EFAULT;
836 
837 	/* force terminating '\0' */
838 	ret = put_user(0, p + len - 1);
839 	return ret ? -EFAULT : len;
840 }
841 
842 static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
843 				 unsigned long arg, void __user *p)
844 {
845 	int			retval;
846 	struct uinput_device	*udev = file->private_data;
847 	struct uinput_ff_upload ff_up;
848 	struct uinput_ff_erase  ff_erase;
849 	struct uinput_request   *req;
850 	char			*phys;
851 	const char		*name;
852 	unsigned int		size;
853 
854 	retval = mutex_lock_interruptible(&udev->mutex);
855 	if (retval)
856 		return retval;
857 
858 	if (!udev->dev) {
859 		udev->dev = input_allocate_device();
860 		if (!udev->dev) {
861 			retval = -ENOMEM;
862 			goto out;
863 		}
864 	}
865 
866 	switch (cmd) {
867 	case UI_GET_VERSION:
868 		if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
869 			retval = -EFAULT;
870 		goto out;
871 
872 	case UI_DEV_CREATE:
873 		retval = uinput_create_device(udev);
874 		goto out;
875 
876 	case UI_DEV_DESTROY:
877 		uinput_destroy_device(udev);
878 		goto out;
879 
880 	case UI_DEV_SETUP:
881 		retval = uinput_dev_setup(udev, p);
882 		goto out;
883 
884 	/* UI_ABS_SETUP is handled in the variable size ioctls */
885 
886 	case UI_SET_EVBIT:
887 		retval = uinput_set_bit(arg, evbit, EV_MAX);
888 		goto out;
889 
890 	case UI_SET_KEYBIT:
891 		retval = uinput_set_bit(arg, keybit, KEY_MAX);
892 		goto out;
893 
894 	case UI_SET_RELBIT:
895 		retval = uinput_set_bit(arg, relbit, REL_MAX);
896 		goto out;
897 
898 	case UI_SET_ABSBIT:
899 		retval = uinput_set_bit(arg, absbit, ABS_MAX);
900 		goto out;
901 
902 	case UI_SET_MSCBIT:
903 		retval = uinput_set_bit(arg, mscbit, MSC_MAX);
904 		goto out;
905 
906 	case UI_SET_LEDBIT:
907 		retval = uinput_set_bit(arg, ledbit, LED_MAX);
908 		goto out;
909 
910 	case UI_SET_SNDBIT:
911 		retval = uinput_set_bit(arg, sndbit, SND_MAX);
912 		goto out;
913 
914 	case UI_SET_FFBIT:
915 		retval = uinput_set_bit(arg, ffbit, FF_MAX);
916 		goto out;
917 
918 	case UI_SET_SWBIT:
919 		retval = uinput_set_bit(arg, swbit, SW_MAX);
920 		goto out;
921 
922 	case UI_SET_PROPBIT:
923 		retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
924 		goto out;
925 
926 	case UI_SET_PHYS:
927 		if (udev->state == UIST_CREATED) {
928 			retval = -EINVAL;
929 			goto out;
930 		}
931 
932 		phys = strndup_user(p, 1024);
933 		if (IS_ERR(phys)) {
934 			retval = PTR_ERR(phys);
935 			goto out;
936 		}
937 
938 		kfree(udev->dev->phys);
939 		udev->dev->phys = phys;
940 		goto out;
941 
942 	case UI_BEGIN_FF_UPLOAD:
943 		retval = uinput_ff_upload_from_user(p, &ff_up);
944 		if (retval)
945 			goto out;
946 
947 		req = uinput_request_find(udev, ff_up.request_id);
948 		if (!req || req->code != UI_FF_UPLOAD ||
949 		    !req->u.upload.effect) {
950 			retval = -EINVAL;
951 			goto out;
952 		}
953 
954 		ff_up.retval = 0;
955 		ff_up.effect = *req->u.upload.effect;
956 		if (req->u.upload.old)
957 			ff_up.old = *req->u.upload.old;
958 		else
959 			memset(&ff_up.old, 0, sizeof(struct ff_effect));
960 
961 		retval = uinput_ff_upload_to_user(p, &ff_up);
962 		goto out;
963 
964 	case UI_BEGIN_FF_ERASE:
965 		if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
966 			retval = -EFAULT;
967 			goto out;
968 		}
969 
970 		req = uinput_request_find(udev, ff_erase.request_id);
971 		if (!req || req->code != UI_FF_ERASE) {
972 			retval = -EINVAL;
973 			goto out;
974 		}
975 
976 		ff_erase.retval = 0;
977 		ff_erase.effect_id = req->u.effect_id;
978 		if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
979 			retval = -EFAULT;
980 			goto out;
981 		}
982 
983 		goto out;
984 
985 	case UI_END_FF_UPLOAD:
986 		retval = uinput_ff_upload_from_user(p, &ff_up);
987 		if (retval)
988 			goto out;
989 
990 		req = uinput_request_find(udev, ff_up.request_id);
991 		if (!req || req->code != UI_FF_UPLOAD ||
992 		    !req->u.upload.effect) {
993 			retval = -EINVAL;
994 			goto out;
995 		}
996 
997 		req->retval = ff_up.retval;
998 		complete(&req->done);
999 		goto out;
1000 
1001 	case UI_END_FF_ERASE:
1002 		if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
1003 			retval = -EFAULT;
1004 			goto out;
1005 		}
1006 
1007 		req = uinput_request_find(udev, ff_erase.request_id);
1008 		if (!req || req->code != UI_FF_ERASE) {
1009 			retval = -EINVAL;
1010 			goto out;
1011 		}
1012 
1013 		req->retval = ff_erase.retval;
1014 		complete(&req->done);
1015 		goto out;
1016 	}
1017 
1018 	size = _IOC_SIZE(cmd);
1019 
1020 	/* Now check variable-length commands */
1021 	switch (cmd & ~IOCSIZE_MASK) {
1022 	case UI_GET_SYSNAME(0):
1023 		if (udev->state != UIST_CREATED) {
1024 			retval = -ENOENT;
1025 			goto out;
1026 		}
1027 		name = dev_name(&udev->dev->dev);
1028 		retval = uinput_str_to_user(p, name, size);
1029 		goto out;
1030 
1031 	case UI_ABS_SETUP & ~IOCSIZE_MASK:
1032 		retval = uinput_abs_setup(udev, p, size);
1033 		goto out;
1034 	}
1035 
1036 	retval = -EINVAL;
1037  out:
1038 	mutex_unlock(&udev->mutex);
1039 	return retval;
1040 }
1041 
1042 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1043 {
1044 	return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
1045 }
1046 
1047 #ifdef CONFIG_COMPAT
1048 
1049 #define UI_SET_PHYS_COMPAT	_IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
1050 
1051 static long uinput_compat_ioctl(struct file *file,
1052 				unsigned int cmd, unsigned long arg)
1053 {
1054 	if (cmd == UI_SET_PHYS_COMPAT)
1055 		cmd = UI_SET_PHYS;
1056 
1057 	return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
1058 }
1059 #endif
1060 
1061 static const struct file_operations uinput_fops = {
1062 	.owner		= THIS_MODULE,
1063 	.open		= uinput_open,
1064 	.release	= uinput_release,
1065 	.read		= uinput_read,
1066 	.write		= uinput_write,
1067 	.poll		= uinput_poll,
1068 	.unlocked_ioctl	= uinput_ioctl,
1069 #ifdef CONFIG_COMPAT
1070 	.compat_ioctl	= uinput_compat_ioctl,
1071 #endif
1072 	.llseek		= no_llseek,
1073 };
1074 
1075 static struct miscdevice uinput_misc = {
1076 	.fops		= &uinput_fops,
1077 	.minor		= UINPUT_MINOR,
1078 	.name		= UINPUT_NAME,
1079 };
1080 module_misc_device(uinput_misc);
1081 
1082 MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
1083 MODULE_ALIAS("devname:" UINPUT_NAME);
1084 
1085 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
1086 MODULE_DESCRIPTION("User level driver support for input subsystem");
1087 MODULE_LICENSE("GPL");
1088 MODULE_VERSION("0.3");
1089