summaryrefslogtreecommitdiffstats
path: root/drivers/hid/hidraw.c
blob: 5fbe0f81ab2ebd2c972237fa1be2bc3b544afee8 (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
/*
 * HID raw devices, giving access to raw HID events.
 *
 * In comparison to hiddev, this device does not process the
 * hid events at all (no parsing, no lookups). This lets applications
 * to work on raw hid events as they want to, and avoids a need to
 * use a transport-specific userspace libhid/libusb libraries.
 *
 *  Copyright (c) 2007-2014 Jiri Kosina
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/sched/signal.h>
#include <linux/string.h>

#include <linux/hidraw.h>

static int hidraw_major;
static struct cdev hidraw_cdev;
static struct class *hidraw_class;
static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
static DEFINE_MUTEX(minors_lock);

static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct hidraw_list *list = file->private_data;
	int ret = 0, len;
	DECLARE_WAITQUEUE(wait, current);

	mutex_lock(&list->read_mutex);

	while (ret == 0) {
		if (list->head == list->tail) {
			add_wait_queue(&list->hidraw->wait, &wait);
			set_current_state(TASK_INTERRUPTIBLE);

			while (list->head == list->tail) {
				if (signal_pending(current)) {
					ret = -ERESTARTSYS;
					break;
				}
				if (!list->hidraw->exist) {
					ret = -EIO;
					break;
				}
				if (file->f_flags & O_NONBLOCK) {
					ret = -EAGAIN;
					break;
				}

				/* allow O_NONBLOCK to work well from other threads */
				mutex_unlock(&list->read_mutex);
				schedule();
				mutex_lock(&list->read_mutex);
				set_current_state(TASK_INTERRUPTIBLE);
			}

			set_current_state(TASK_RUNNING);
			remove_wait_queue(&list->hidraw->wait, &wait);
		}

		if (ret)
			goto out;

		len = list->buffer[list->tail].len > count ?
			count : list->buffer[list->tail].len;

		if (list->buffer[list->tail].value) {
			if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
				ret = -EFAULT;
				goto out;
			}
			ret = len;
		}

		kfree(list->buffer[list->tail].value);
		list->buffer[list->tail].value = NULL;
		list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
	}
out:
	mutex_unlock(&list->read_mutex);
	return ret;
}

/*
 * The first byte of the report buffer is expected to be a report number.
 *
 * This function is to be called with the minors_lock mutex held.
 */
static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
{
	unsigned int minor = iminor(file_inode(file));
	struct hid_device *dev;
	__u8 *buf;
	int ret = 0;

	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
		ret = -ENODEV;
		goto out;
	}

	dev = hidraw_table[minor]->hid;

	if (count > HID_MAX_BUFFER_SIZE) {
		hid_warn(dev, "pid %d passed too large report\n",
			 task_pid_nr(current));
		ret = -EINVAL;
		goto out;
	}

	if (count < 2) {
		hid_warn(dev, "pid %d passed too short report\n",
			 task_pid_nr(current));
		ret = -EINVAL;
		goto out;
	}

	buf = memdup_user(buffer, count);
	if (IS_ERR(buf)) {
		ret = PTR_ERR(buf);
		goto out;
	}

	if ((report_type == HID_OUTPUT_REPORT) &&
	    !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
		ret = hid_hw_output_report(dev, buf, count);
		/*
		 * compatibility with old implementation of USB-HID and I2C-HID:
		 * if the device does not support receiving output reports,
		 * on an interrupt endpoint, fallback to SET_REPORT HID command.
		 */
		if (ret != -ENOSYS)
			goto out_free;
	}

	ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
				HID_REQ_SET_REPORT);

out_free:
	kfree(buf);
out:
	return ret;
}

static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	ssize_t ret;
	mutex_lock(&minors_lock);
	ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
	mutex_unlock(&minors_lock);
	return ret;
}


/*
 * This function performs a Get_Report transfer over the control endpoint
 * per section 7.2.1 of the HID specification, version 1.1.  The first byte
 * of buffer is the report number to request, or 0x0 if the defice does not
 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
 * or HID_INPUT_REPORT.
 *
 * This function is to be called with the minors_lock mutex held.
 */
static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
{
	unsigned int minor = iminor(file_inode(file));
	struct hid_device *dev;
	__u8 *buf;
	int ret = 0, len;
	unsigned char report_number;

	dev = hidraw_table[minor]->hid;

	if (!dev->ll_driver->raw_request) {
		ret = -ENODEV;
		goto out;
	}

	if (count > HID_MAX_BUFFER_SIZE) {
		printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
				task_pid_nr(current));
		ret = -EINVAL;
		goto out;
	}

	if (count < 2) {
		printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
				task_pid_nr(current));
		ret = -EINVAL;
		goto out;
	}

	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
	if (!buf) {
		ret = -ENOMEM;
		goto out;
	}

	/*
	 * Read the first byte from the user. This is the report number,
	 * which is passed to hid_hw_raw_request().
	 */
	if (copy_from_user(&report_number, buffer, 1)) {
		ret = -EFAULT;
		goto out_free;
	}

	ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
				 HID_REQ_GET_REPORT);

	if (ret < 0)
		goto out_free;

	len = (ret < count) ? ret : count;

	if (copy_to_user(buffer, buf, len)) {
		ret = -EFAULT;
		goto out_free;
	}

	ret = len;

out_free:
	kfree(buf);
out:
	return ret;
}

static unsigned int hidraw_poll(struct file *file, poll_table *wait)
{
	struct hidraw_list *list = file->private_data;

	poll_wait(file, &list->hidraw->wait, wait);
	if (list->head != list->tail)
		return POLLIN | POLLRDNORM;
	if (!list->hidraw->exist)
		return POLLERR | POLLHUP;
	return 0;
}

static int hidraw_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	struct hidraw *dev;
	struct hidraw_list *list;
	unsigned long flags;
	int err = 0;

	if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
		err = -ENOMEM;
		goto out;
	}

	mutex_lock(&minors_lock);
	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
		err = -ENODEV;
		goto out_unlock;
	}

	dev = hidraw_table[minor];
	if (!dev->open++) {
		err = hid_hw_power(dev->hid, PM_HINT_FULLON);
		if (err < 0) {
			dev->open--;
			goto out_unlock;
		}

		err = hid_hw_open(dev->hid);
		if (err < 0) {
			hid_hw_power(dev->hid, PM_HINT_NORMAL);
			dev->open--;
			goto out_unlock;
		}
	}

	list->hidraw = hidraw_table[minor];
	mutex_init(&list->read_mutex);
	spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
	list_add_tail(&list->node, &hidraw_table[minor]->list);
	spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
	file->private_data = list;
out_unlock:
	mutex_unlock(&minors_lock);
out:
	if (err < 0)
		kfree(list);
	return err;

}

static int hidraw_fasync(int fd, struct file *file, int on)
{
	struct hidraw_list *list = file->private_data;

	return fasync_helper(fd, file, on, &list->fasync);
}

static void drop_ref(struct hidraw *hidraw, int exists_bit)
{
	if (exists_bit) {
		hidraw->exist = 0;
		if (hidraw->open) {
			hid_hw_close(hidraw->hid);
			wake_up_interruptible(&hidraw->wait);
		}
		device_destroy(hidraw_class,
			       MKDEV(hidraw_major, hidraw->minor));
	} else {
		--hidraw->open;
	}
	if (!hidraw->open) {
		if (!hidraw->exist) {
			hidraw_table[hidraw->minor] = NULL;
			kfree(hidraw);
		} else {
			/* close device for last reader */
			hid_hw_close(hidraw->hid);
			hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
		}
	}
}

static int hidraw_release(struct inode * inode, struct file * file)
{
	unsigned int minor = iminor(inode);
	struct hidraw_list *list = file->private_data;
	unsigned long flags;

	mutex_lock(&minors_lock);

	spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
	list_del(&list->node);
	spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
	kfree(list);

	drop_ref(hidraw_table[minor], 0);

	mutex_unlock(&minors_lock);
	return 0;
}

static long hidraw_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	struct inode *inode = file_inode(file);
	unsigned int minor = iminor(inode);
	long ret = 0;
	struct hidraw *dev;
	void __user *user_arg = (void __user*) arg;

	mutex_lock(&minors_lock);
	dev = hidraw_table[minor];
	if (!dev) {
		ret = -ENODEV;
		goto out;
	}

	switch (cmd) {
		case HIDIOCGRDESCSIZE:
			if (put_user(dev->hid->rsize, (int __user *)arg))
				ret = -EFAULT;
			break;

		case HIDIOCGRDESC:
			{
				__u32 len;

				if (get_user(len, (int __user *)arg))
					ret = -EFAULT;
				else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
					ret = -EINVAL;
				else if (copy_to_user(user_arg + offsetof(
					struct hidraw_report_descriptor,
					value[0]),
					dev->hid->rdesc,
					min(dev->hid->rsize, len)))
					ret = -EFAULT;
				break;
			}
		case HIDIOCGRAWINFO:
			{
				struct hidraw_devinfo dinfo;

				dinfo.bustype = dev->hid->bus;
				dinfo.vendor = dev->hid->vendor;
				dinfo.product = dev->hid->product;
				if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
					ret = -EFAULT;
				break;
			}
		default:
			{
				struct hid_device *hid = dev->hid;
				if (_IOC_TYPE(cmd) != 'H') {
					ret = -EINVAL;
					break;
				}

				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
					int len = _IOC_SIZE(cmd);
					ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
					break;
				}
				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
					int len = _IOC_SIZE(cmd);
					ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
					break;
				}

				/* Begin Read-only ioctls. */
				if (_IOC_DIR(cmd) != _IOC_READ) {
					ret = -EINVAL;
					break;
				}

				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
					int len = strlen(hid->name) + 1;
					if (len > _IOC_SIZE(cmd))
						len = _IOC_SIZE(cmd);
					ret = copy_to_user(user_arg, hid->name, len) ?
						-EFAULT : len;
					break;
				}

				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
					int len = strlen(hid->phys) + 1;
					if (len > _IOC_SIZE(cmd))
						len = _IOC_SIZE(cmd);
					ret = copy_to_user(user_arg, hid->phys, len) ?
						-EFAULT : len;
					break;
				}
			}

		ret = -ENOTTY;
	}
out:
	mutex_unlock(&minors_lock);
	return ret;
}

static const struct file_operations hidraw_ops = {
	.owner =        THIS_MODULE,
	.read =         hidraw_read,
	.write =        hidraw_write,
	.poll =         hidraw_poll,
	.open =         hidraw_open,
	.release =      hidraw_release,
	.unlocked_ioctl = hidraw_ioctl,
	.fasync =	hidraw_fasync,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = hidraw_ioctl,
#endif
	.llseek =	noop_llseek,
};

int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
{
	struct hidraw *dev = hid->hidraw;
	struct hidraw_list *list;
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&dev->list_lock, flags);
	list_for_each_entry(list, &dev->list, node) {
		int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);

		if (new_head == list->tail)
			continue;

		if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
			ret = -ENOMEM;
			break;
		}
		list->buffer[list->head].len = len;
		list->head = new_head;
		kill_fasync(&list->fasync, SIGIO, POLL_IN);
	}
	spin_unlock_irqrestore(&dev->list_lock, flags);

	wake_up_interruptible(&dev->wait);
	return ret;
}
EXPORT_SYMBOL_GPL(hidraw_report_event);

int hidraw_connect(struct hid_device *hid)
{
	int minor, result;
	struct hidraw *dev;

	/* we accept any HID device, all applications */

	dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	result = -EINVAL;

	mutex_lock(&minors_lock);

	for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
		if (hidraw_table[minor])
			continue;
		hidraw_table[minor] = dev;
		result = 0;
		break;
	}

	if (result) {
		mutex_unlock(&minors_lock);
		kfree(dev);
		goto out;
	}

	dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
				 NULL, "%s%d", "hidraw", minor);

	if (IS_ERR(dev->dev)) {
		hidraw_table[minor] = NULL;
		mutex_unlock(&minors_lock);
		result = PTR_ERR(dev->dev);
		kfree(dev);
		goto out;
	}

	init_waitqueue_head(&dev->wait);
	spin_lock_init(&dev->list_lock);
	INIT_LIST_HEAD(&dev->list);

	dev->hid = hid;
	dev->minor = minor;

	dev->exist = 1;
	hid->hidraw = dev;

	mutex_unlock(&minors_lock);
out:
	return result;

}
EXPORT_SYMBOL_GPL(hidraw_connect);

void hidraw_disconnect(struct hid_device *hid)
{
	struct hidraw *hidraw = hid->hidraw;

	mutex_lock(&minors_lock);

	drop_ref(hidraw, 1);

	mutex_unlock(&minors_lock);
}
EXPORT_SYMBOL_GPL(hidraw_disconnect);

int __init hidraw_init(void)
{
	int result;
	dev_t dev_id;

	result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
			HIDRAW_MAX_DEVICES, "hidraw");
	if (result < 0) {
		pr_warn("can't get major number\n");
		goto out;
	}

	hidraw_major = MAJOR(dev_id);

	hidraw_class = class_create(THIS_MODULE, "hidraw");
	if (IS_ERR(hidraw_class)) {
		result = PTR_ERR(hidraw_class);
		goto error_cdev;
	}

        cdev_init(&hidraw_cdev, &hidraw_ops);
	result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
	if (result < 0)
		goto error_class;

	printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
out:
	return result;

error_class:
	class_destroy(hidraw_class);
error_cdev:
	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
	goto out;
}

void hidraw_exit(void)
{
	dev_t dev_id = MKDEV(hidraw_major, 0);

	cdev_del(&hidraw_cdev);
	class_destroy(hidraw_class);
	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);

}
OpenPOWER on IntegriCloud