summaryrefslogtreecommitdiffstats
path: root/drivers/input/misc/uinput.c
blob: 443151de90c6b506f6847b656a68d84577576ad1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
/*
 *  User level driver support for input subsystem
 *
 * Heavily based on evdev.c by Vojtech Pavlik
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
 *
 * Changes/Revisions:
 *	0.4	01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
 *		- add UI_GET_SYSNAME ioctl
 *	0.3	09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
 *		- updated ff support for the changes in kernel interface
 *		- added MODULE_VERSION
 *	0.2	16/10/2004 (Micah Dowty <micah@navi.cx>)
 *		- added force feedback support
 *              - added UI_SET_PHYS
 *	0.1	20/06/2002
 *		- first public version
 */
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/uinput.h>
#include <linux/input/mt.h>
#include "../input-compat.h"

static int uinput_dev_event(struct input_dev *dev,
			    unsigned int type, unsigned int code, int value)
{
	struct uinput_device	*udev = input_get_drvdata(dev);

	udev->buff[udev->head].type = type;
	udev->buff[udev->head].code = code;
	udev->buff[udev->head].value = value;
	do_gettimeofday(&udev->buff[udev->head].time);
	udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;

	wake_up_interruptible(&udev->waitq);

	return 0;
}

/* Atomically allocate an ID for the given request. Returns 0 on success. */
static bool uinput_request_alloc_id(struct uinput_device *udev,
				    struct uinput_request *request)
{
	unsigned int id;
	bool reserved = false;

	spin_lock(&udev->requests_lock);

	for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
		if (!udev->requests[id]) {
			request->id = id;
			udev->requests[id] = request;
			reserved = true;
			break;
		}
	}

	spin_unlock(&udev->requests_lock);
	return reserved;
}

static struct uinput_request *uinput_request_find(struct uinput_device *udev,
						  unsigned int id)
{
	/* Find an input request, by ID. Returns NULL if the ID isn't valid. */
	if (id >= UINPUT_NUM_REQUESTS)
		return NULL;

	return udev->requests[id];
}

static int uinput_request_reserve_slot(struct uinput_device *udev,
				       struct uinput_request *request)
{
	/* Allocate slot. If none are available right away, wait. */
	return wait_event_interruptible(udev->requests_waitq,
					uinput_request_alloc_id(udev, request));
}

static void uinput_request_release_slot(struct uinput_device *udev,
					unsigned int id)
{
	/* Mark slot as available */
	spin_lock(&udev->requests_lock);
	udev->requests[id] = NULL;
	spin_unlock(&udev->requests_lock);

	wake_up(&udev->requests_waitq);
}

static int uinput_request_send(struct uinput_device *udev,
			       struct uinput_request *request)
{
	int retval;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	if (udev->state != UIST_CREATED) {
		retval = -ENODEV;
		goto out;
	}

	init_completion(&request->done);

	/*
	 * Tell our userspace application about this new request
	 * by queueing an input event.
	 */
	uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);

 out:
	mutex_unlock(&udev->mutex);
	return retval;
}

static int uinput_request_submit(struct uinput_device *udev,
				 struct uinput_request *request)
{
	int retval;

	retval = uinput_request_reserve_slot(udev, request);
	if (retval)
		return retval;

	retval = uinput_request_send(udev, request);
	if (retval)
		goto out;

	wait_for_completion(&request->done);
	retval = request->retval;

 out:
	uinput_request_release_slot(udev, request->id);
	return retval;
}

/*
 * Fail all outstanding requests so handlers don't wait for the userspace
 * to finish processing them.
 */
static void uinput_flush_requests(struct uinput_device *udev)
{
	struct uinput_request *request;
	int i;

	spin_lock(&udev->requests_lock);

	for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
		request = udev->requests[i];
		if (request) {
			request->retval = -ENODEV;
			complete(&request->done);
		}
	}

	spin_unlock(&udev->requests_lock);
}

static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
{
	uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
}

static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
{
	uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
}

static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
{
	return uinput_dev_event(dev, EV_FF, effect_id, value);
}

static int uinput_dev_upload_effect(struct input_dev *dev,
				    struct ff_effect *effect,
				    struct ff_effect *old)
{
	struct uinput_device *udev = input_get_drvdata(dev);
	struct uinput_request request;

	/*
	 * uinput driver does not currently support periodic effects with
	 * custom waveform since it does not have a way to pass buffer of
	 * samples (custom_data) to userspace. If ever there is a device
	 * supporting custom waveforms we would need to define an additional
	 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
	 */
	if (effect->type == FF_PERIODIC &&
			effect->u.periodic.waveform == FF_CUSTOM)
		return -EINVAL;

	request.code = UI_FF_UPLOAD;
	request.u.upload.effect = effect;
	request.u.upload.old = old;

	return uinput_request_submit(udev, &request);
}

static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
{
	struct uinput_device *udev = input_get_drvdata(dev);
	struct uinput_request request;

	if (!test_bit(EV_FF, dev->evbit))
		return -ENOSYS;

	request.code = UI_FF_ERASE;
	request.u.effect_id = effect_id;

	return uinput_request_submit(udev, &request);
}

static int uinput_dev_flush(struct input_dev *dev, struct file *file)
{
	/*
	 * If we are called with file == NULL that means we are tearing
	 * down the device, and therefore we can not handle FF erase
	 * requests: either we are handling UI_DEV_DESTROY (and holding
	 * the udev->mutex), or the file descriptor is closed and there is
	 * nobody on the other side anymore.
	 */
	return file ? input_ff_flush(dev, file) : 0;
}

static void uinput_destroy_device(struct uinput_device *udev)
{
	const char *name, *phys;
	struct input_dev *dev = udev->dev;
	enum uinput_state old_state = udev->state;

	udev->state = UIST_NEW_DEVICE;

	if (dev) {
		name = dev->name;
		phys = dev->phys;
		if (old_state == UIST_CREATED) {
			uinput_flush_requests(udev);
			input_unregister_device(dev);
		} else {
			input_free_device(dev);
		}
		kfree(name);
		kfree(phys);
		udev->dev = NULL;
	}
}

static int uinput_create_device(struct uinput_device *udev)
{
	struct input_dev *dev = udev->dev;
	int error, nslot;

	if (udev->state != UIST_SETUP_COMPLETE) {
		printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
		return -EINVAL;
	}

	if (test_bit(EV_ABS, dev->evbit)) {
		input_alloc_absinfo(dev);
		if (!dev->absinfo) {
			error = -EINVAL;
			goto fail1;
		}

		if (test_bit(ABS_MT_SLOT, dev->absbit)) {
			nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
			error = input_mt_init_slots(dev, nslot, 0);
			if (error)
				goto fail1;
		} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
			input_set_events_per_packet(dev, 60);
		}
	}

	if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
		printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
			UINPUT_NAME);
		error = -EINVAL;
		goto fail1;
	}

	if (udev->ff_effects_max) {
		error = input_ff_create(dev, udev->ff_effects_max);
		if (error)
			goto fail1;

		dev->ff->upload = uinput_dev_upload_effect;
		dev->ff->erase = uinput_dev_erase_effect;
		dev->ff->playback = uinput_dev_playback;
		dev->ff->set_gain = uinput_dev_set_gain;
		dev->ff->set_autocenter = uinput_dev_set_autocenter;
		/*
		 * The standard input_ff_flush() implementation does
		 * not quite work for uinput as we can't reasonably
		 * handle FF requests during device teardown.
		 */
		dev->flush = uinput_dev_flush;
	}

	error = input_register_device(udev->dev);
	if (error)
		goto fail2;

	udev->state = UIST_CREATED;

	return 0;

 fail2:	input_ff_destroy(dev);
 fail1: uinput_destroy_device(udev);
	return error;
}

static int uinput_open(struct inode *inode, struct file *file)
{
	struct uinput_device *newdev;

	newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
	if (!newdev)
		return -ENOMEM;

	mutex_init(&newdev->mutex);
	spin_lock_init(&newdev->requests_lock);
	init_waitqueue_head(&newdev->requests_waitq);
	init_waitqueue_head(&newdev->waitq);
	newdev->state = UIST_NEW_DEVICE;

	file->private_data = newdev;
	nonseekable_open(inode, file);

	return 0;
}

static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
				   const struct input_absinfo *abs)
{
	int min, max;

	min = abs->minimum;
	max = abs->maximum;

	if ((min != 0 || max != 0) && max <= min) {
		printk(KERN_DEBUG
		       "%s: invalid abs[%02x] min:%d max:%d\n",
		       UINPUT_NAME, code, min, max);
		return -EINVAL;
	}

	if (abs->flat > max - min) {
		printk(KERN_DEBUG
		       "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
		       UINPUT_NAME, code, abs->flat, min, max);
		return -EINVAL;
	}

	return 0;
}

static int uinput_validate_absbits(struct input_dev *dev)
{
	unsigned int cnt;
	int error;

	if (!test_bit(EV_ABS, dev->evbit))
		return 0;

	/*
	 * Check if absmin/absmax/absfuzz/absflat are sane.
	 */

	for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
		if (!dev->absinfo)
			return -EINVAL;

		error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
		if (error)
			return error;
	}

	return 0;
}

static int uinput_allocate_device(struct uinput_device *udev)
{
	udev->dev = input_allocate_device();
	if (!udev->dev)
		return -ENOMEM;

	udev->dev->event = uinput_dev_event;
	input_set_drvdata(udev->dev, udev);

	return 0;
}

static int uinput_dev_setup(struct uinput_device *udev,
			    struct uinput_setup __user *arg)
{
	struct uinput_setup setup;
	struct input_dev *dev;

	if (udev->state == UIST_CREATED)
		return -EINVAL;

	if (copy_from_user(&setup, arg, sizeof(setup)))
		return -EFAULT;

	if (!setup.name[0])
		return -EINVAL;

	dev = udev->dev;
	dev->id = setup.id;
	udev->ff_effects_max = setup.ff_effects_max;

	kfree(dev->name);
	dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
	if (!dev->name)
		return -ENOMEM;

	udev->state = UIST_SETUP_COMPLETE;
	return 0;
}

static int uinput_abs_setup(struct uinput_device *udev,
			    struct uinput_setup __user *arg, size_t size)
{
	struct uinput_abs_setup setup = {};
	struct input_dev *dev;
	int error;

	if (size > sizeof(setup))
		return -E2BIG;

	if (udev->state == UIST_CREATED)
		return -EINVAL;

	if (copy_from_user(&setup, arg, size))
		return -EFAULT;

	if (setup.code > ABS_MAX)
		return -ERANGE;

	dev = udev->dev;

	error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
	if (error)
		return error;

	input_alloc_absinfo(dev);
	if (!dev->absinfo)
		return -ENOMEM;

	set_bit(setup.code, dev->absbit);
	dev->absinfo[setup.code] = setup.absinfo;
	return 0;
}

/* legacy setup via write() */
static int uinput_setup_device_legacy(struct uinput_device *udev,
				      const char __user *buffer, size_t count)
{
	struct uinput_user_dev	*user_dev;
	struct input_dev	*dev;
	int			i;
	int			retval;

	if (count != sizeof(struct uinput_user_dev))
		return -EINVAL;

	if (!udev->dev) {
		retval = uinput_allocate_device(udev);
		if (retval)
			return retval;
	}

	dev = udev->dev;

	user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
	if (IS_ERR(user_dev))
		return PTR_ERR(user_dev);

	udev->ff_effects_max = user_dev->ff_effects_max;

	/* Ensure name is filled in */
	if (!user_dev->name[0]) {
		retval = -EINVAL;
		goto exit;
	}

	kfree(dev->name);
	dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
			     GFP_KERNEL);
	if (!dev->name) {
		retval = -ENOMEM;
		goto exit;
	}

	dev->id.bustype	= user_dev->id.bustype;
	dev->id.vendor	= user_dev->id.vendor;
	dev->id.product	= user_dev->id.product;
	dev->id.version	= user_dev->id.version;

	for (i = 0; i < ABS_CNT; i++) {
		input_abs_set_max(dev, i, user_dev->absmax[i]);
		input_abs_set_min(dev, i, user_dev->absmin[i]);
		input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
		input_abs_set_flat(dev, i, user_dev->absflat[i]);
	}

	retval = uinput_validate_absbits(dev);
	if (retval < 0)
		goto exit;

	udev->state = UIST_SETUP_COMPLETE;
	retval = count;

 exit:
	kfree(user_dev);
	return retval;
}

static ssize_t uinput_inject_events(struct uinput_device *udev,
				    const char __user *buffer, size_t count)
{
	struct input_event ev;
	size_t bytes = 0;

	if (count != 0 && count < input_event_size())
		return -EINVAL;

	while (bytes + input_event_size() <= count) {
		/*
		 * Note that even if some events were fetched successfully
		 * we are still going to return EFAULT instead of partial
		 * count to let userspace know that it got it's buffers
		 * all wrong.
		 */
		if (input_event_from_user(buffer + bytes, &ev))
			return -EFAULT;

		input_event(udev->dev, ev.type, ev.code, ev.value);
		bytes += input_event_size();
	}

	return bytes;
}

static ssize_t uinput_write(struct file *file, const char __user *buffer,
			    size_t count, loff_t *ppos)
{
	struct uinput_device *udev = file->private_data;
	int retval;

	if (count == 0)
		return 0;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	retval = udev->state == UIST_CREATED ?
			uinput_inject_events(udev, buffer, count) :
			uinput_setup_device_legacy(udev, buffer, count);

	mutex_unlock(&udev->mutex);

	return retval;
}

static bool uinput_fetch_next_event(struct uinput_device *udev,
				    struct input_event *event)
{
	bool have_event;

	spin_lock_irq(&udev->dev->event_lock);

	have_event = udev->head != udev->tail;
	if (have_event) {
		*event = udev->buff[udev->tail];
		udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
	}

	spin_unlock_irq(&udev->dev->event_lock);

	return have_event;
}

static ssize_t uinput_events_to_user(struct uinput_device *udev,
				     char __user *buffer, size_t count)
{
	struct input_event event;
	size_t read = 0;

	while (read + input_event_size() <= count &&
	       uinput_fetch_next_event(udev, &event)) {

		if (input_event_to_user(buffer + read, &event))
			return -EFAULT;

		read += input_event_size();
	}

	return read;
}

static ssize_t uinput_read(struct file *file, char __user *buffer,
			   size_t count, loff_t *ppos)
{
	struct uinput_device *udev = file->private_data;
	ssize_t retval;

	if (count != 0 && count < input_event_size())
		return -EINVAL;

	do {
		retval = mutex_lock_interruptible(&udev->mutex);
		if (retval)
			return retval;

		if (udev->state != UIST_CREATED)
			retval = -ENODEV;
		else if (udev->head == udev->tail &&
			 (file->f_flags & O_NONBLOCK))
			retval = -EAGAIN;
		else
			retval = uinput_events_to_user(udev, buffer, count);

		mutex_unlock(&udev->mutex);

		if (retval || count == 0)
			break;

		if (!(file->f_flags & O_NONBLOCK))
			retval = wait_event_interruptible(udev->waitq,
						  udev->head != udev->tail ||
						  udev->state != UIST_CREATED);
	} while (retval == 0);

	return retval;
}

static unsigned int uinput_poll(struct file *file, poll_table *wait)
{
	struct uinput_device *udev = file->private_data;

	poll_wait(file, &udev->waitq, wait);

	if (udev->head != udev->tail)
		return POLLIN | POLLRDNORM;

	return 0;
}

static int uinput_release(struct inode *inode, struct file *file)
{
	struct uinput_device *udev = file->private_data;

	uinput_destroy_device(udev);
	kfree(udev);

	return 0;
}

#ifdef CONFIG_COMPAT
struct uinput_ff_upload_compat {
	__u32			request_id;
	__s32			retval;
	struct ff_effect_compat	effect;
	struct ff_effect_compat	old;
};

static int uinput_ff_upload_to_user(char __user *buffer,
				    const struct uinput_ff_upload *ff_up)
{
	if (in_compat_syscall()) {
		struct uinput_ff_upload_compat ff_up_compat;

		ff_up_compat.request_id = ff_up->request_id;
		ff_up_compat.retval = ff_up->retval;
		/*
		 * It so happens that the pointer that gives us the trouble
		 * is the last field in the structure. Since we don't support
		 * custom waveforms in uinput anyway we can just copy the whole
		 * thing (to the compat size) and ignore the pointer.
		 */
		memcpy(&ff_up_compat.effect, &ff_up->effect,
			sizeof(struct ff_effect_compat));
		memcpy(&ff_up_compat.old, &ff_up->old,
			sizeof(struct ff_effect_compat));

		if (copy_to_user(buffer, &ff_up_compat,
				 sizeof(struct uinput_ff_upload_compat)))
			return -EFAULT;
	} else {
		if (copy_to_user(buffer, ff_up,
				 sizeof(struct uinput_ff_upload)))
			return -EFAULT;
	}

	return 0;
}

static int uinput_ff_upload_from_user(const char __user *buffer,
				      struct uinput_ff_upload *ff_up)
{
	if (in_compat_syscall()) {
		struct uinput_ff_upload_compat ff_up_compat;

		if (copy_from_user(&ff_up_compat, buffer,
				   sizeof(struct uinput_ff_upload_compat)))
			return -EFAULT;

		ff_up->request_id = ff_up_compat.request_id;
		ff_up->retval = ff_up_compat.retval;
		memcpy(&ff_up->effect, &ff_up_compat.effect,
			sizeof(struct ff_effect_compat));
		memcpy(&ff_up->old, &ff_up_compat.old,
			sizeof(struct ff_effect_compat));

	} else {
		if (copy_from_user(ff_up, buffer,
				   sizeof(struct uinput_ff_upload)))
			return -EFAULT;
	}

	return 0;
}

#else

static int uinput_ff_upload_to_user(char __user *buffer,
				    const struct uinput_ff_upload *ff_up)
{
	if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
		return -EFAULT;

	return 0;
}

static int uinput_ff_upload_from_user(const char __user *buffer,
				      struct uinput_ff_upload *ff_up)
{
	if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
		return -EFAULT;

	return 0;
}

#endif

#define uinput_set_bit(_arg, _bit, _max)		\
({							\
	int __ret = 0;					\
	if (udev->state == UIST_CREATED)		\
		__ret =  -EINVAL;			\
	else if ((_arg) > (_max))			\
		__ret = -EINVAL;			\
	else set_bit((_arg), udev->dev->_bit);		\
	__ret;						\
})

static int uinput_str_to_user(void __user *dest, const char *str,
			      unsigned int maxlen)
{
	char __user *p = dest;
	int len, ret;

	if (!str)
		return -ENOENT;

	if (maxlen == 0)
		return -EINVAL;

	len = strlen(str) + 1;
	if (len > maxlen)
		len = maxlen;

	ret = copy_to_user(p, str, len);
	if (ret)
		return -EFAULT;

	/* force terminating '\0' */
	ret = put_user(0, p + len - 1);
	return ret ? -EFAULT : len;
}

static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
				 unsigned long arg, void __user *p)
{
	int			retval;
	struct uinput_device	*udev = file->private_data;
	struct uinput_ff_upload ff_up;
	struct uinput_ff_erase  ff_erase;
	struct uinput_request   *req;
	char			*phys;
	const char		*name;
	unsigned int		size;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	if (!udev->dev) {
		retval = uinput_allocate_device(udev);
		if (retval)
			goto out;
	}

	switch (cmd) {
		case UI_GET_VERSION:
			if (put_user(UINPUT_VERSION,
				     (unsigned int __user *)p))
				retval = -EFAULT;
			goto out;

		case UI_DEV_CREATE:
			retval = uinput_create_device(udev);
			goto out;

		case UI_DEV_DESTROY:
			uinput_destroy_device(udev);
			goto out;

		case UI_DEV_SETUP:
			retval = uinput_dev_setup(udev, p);
			goto out;

		/* UI_ABS_SETUP is handled in the variable size ioctls */

		case UI_SET_EVBIT:
			retval = uinput_set_bit(arg, evbit, EV_MAX);
			goto out;

		case UI_SET_KEYBIT:
			retval = uinput_set_bit(arg, keybit, KEY_MAX);
			goto out;

		case UI_SET_RELBIT:
			retval = uinput_set_bit(arg, relbit, REL_MAX);
			goto out;

		case UI_SET_ABSBIT:
			retval = uinput_set_bit(arg, absbit, ABS_MAX);
			goto out;

		case UI_SET_MSCBIT:
			retval = uinput_set_bit(arg, mscbit, MSC_MAX);
			goto out;

		case UI_SET_LEDBIT:
			retval = uinput_set_bit(arg, ledbit, LED_MAX);
			goto out;

		case UI_SET_SNDBIT:
			retval = uinput_set_bit(arg, sndbit, SND_MAX);
			goto out;

		case UI_SET_FFBIT:
			retval = uinput_set_bit(arg, ffbit, FF_MAX);
			goto out;

		case UI_SET_SWBIT:
			retval = uinput_set_bit(arg, swbit, SW_MAX);
			goto out;

		case UI_SET_PROPBIT:
			retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
			goto out;

		case UI_SET_PHYS:
			if (udev->state == UIST_CREATED) {
				retval = -EINVAL;
				goto out;
			}

			phys = strndup_user(p, 1024);
			if (IS_ERR(phys)) {
				retval = PTR_ERR(phys);
				goto out;
			}

			kfree(udev->dev->phys);
			udev->dev->phys = phys;
			goto out;

		case UI_BEGIN_FF_UPLOAD:
			retval = uinput_ff_upload_from_user(p, &ff_up);
			if (retval)
				goto out;

			req = uinput_request_find(udev, ff_up.request_id);
			if (!req || req->code != UI_FF_UPLOAD ||
			    !req->u.upload.effect) {
				retval = -EINVAL;
				goto out;
			}

			ff_up.retval = 0;
			ff_up.effect = *req->u.upload.effect;
			if (req->u.upload.old)
				ff_up.old = *req->u.upload.old;
			else
				memset(&ff_up.old, 0, sizeof(struct ff_effect));

			retval = uinput_ff_upload_to_user(p, &ff_up);
			goto out;

		case UI_BEGIN_FF_ERASE:
			if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
				retval = -EFAULT;
				goto out;
			}

			req = uinput_request_find(udev, ff_erase.request_id);
			if (!req || req->code != UI_FF_ERASE) {
				retval = -EINVAL;
				goto out;
			}

			ff_erase.retval = 0;
			ff_erase.effect_id = req->u.effect_id;
			if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
				retval = -EFAULT;
				goto out;
			}

			goto out;

		case UI_END_FF_UPLOAD:
			retval = uinput_ff_upload_from_user(p, &ff_up);
			if (retval)
				goto out;

			req = uinput_request_find(udev, ff_up.request_id);
			if (!req || req->code != UI_FF_UPLOAD ||
			    !req->u.upload.effect) {
				retval = -EINVAL;
				goto out;
			}

			req->retval = ff_up.retval;
			complete(&req->done);
			goto out;

		case UI_END_FF_ERASE:
			if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
				retval = -EFAULT;
				goto out;
			}

			req = uinput_request_find(udev, ff_erase.request_id);
			if (!req || req->code != UI_FF_ERASE) {
				retval = -EINVAL;
				goto out;
			}

			req->retval = ff_erase.retval;
			complete(&req->done);
			goto out;
	}

	size = _IOC_SIZE(cmd);

	/* Now check variable-length commands */
	switch (cmd & ~IOCSIZE_MASK) {
	case UI_GET_SYSNAME(0):
		if (udev->state != UIST_CREATED) {
			retval = -ENOENT;
			goto out;
		}
		name = dev_name(&udev->dev->dev);
		retval = uinput_str_to_user(p, name, size);
		goto out;

	case UI_ABS_SETUP & ~IOCSIZE_MASK:
		retval = uinput_abs_setup(udev, p, size);
		goto out;
	}

	retval = -EINVAL;
 out:
	mutex_unlock(&udev->mutex);
	return retval;
}

static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
}

#ifdef CONFIG_COMPAT

#define UI_SET_PHYS_COMPAT	_IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)

static long uinput_compat_ioctl(struct file *file,
				unsigned int cmd, unsigned long arg)
{
	if (cmd == UI_SET_PHYS_COMPAT)
		cmd = UI_SET_PHYS;

	return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
}
#endif

static const struct file_operations uinput_fops = {
	.owner		= THIS_MODULE,
	.open		= uinput_open,
	.release	= uinput_release,
	.read		= uinput_read,
	.write		= uinput_write,
	.poll		= uinput_poll,
	.unlocked_ioctl	= uinput_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= uinput_compat_ioctl,
#endif
	.llseek		= no_llseek,
};

static struct miscdevice uinput_misc = {
	.fops		= &uinput_fops,
	.minor		= UINPUT_MINOR,
	.name		= UINPUT_NAME,
};
module_misc_device(uinput_misc);

MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
MODULE_ALIAS("devname:" UINPUT_NAME);

MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
MODULE_DESCRIPTION("User level driver support for input subsystem");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.3");
OpenPOWER on IntegriCloud