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