xref: /openbmc/linux/drivers/hid/usbhid/hiddev.c (revision 715f23b6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) 2001 Paul Stewart
4  *  Copyright (c) 2001 Vojtech Pavlik
5  *
6  *  HID char devices, giving access to raw HID device events.
7  */
8 
9 /*
10  *
11  * Should you need to contact me, the author, you can do so either by
12  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
13  */
14 
15 #include <linux/poll.h>
16 #include <linux/slab.h>
17 #include <linux/sched/signal.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/input.h>
21 #include <linux/usb.h>
22 #include <linux/hid.h>
23 #include <linux/hiddev.h>
24 #include <linux/compat.h>
25 #include <linux/vmalloc.h>
26 #include <linux/nospec.h>
27 #include "usbhid.h"
28 
29 #ifdef CONFIG_USB_DYNAMIC_MINORS
30 #define HIDDEV_MINOR_BASE	0
31 #define HIDDEV_MINORS		256
32 #else
33 #define HIDDEV_MINOR_BASE	96
34 #define HIDDEV_MINORS		16
35 #endif
36 #define HIDDEV_BUFFER_SIZE	2048
37 
38 struct hiddev_list {
39 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
40 	int head;
41 	int tail;
42 	unsigned flags;
43 	struct fasync_struct *fasync;
44 	struct hiddev *hiddev;
45 	struct list_head node;
46 	struct mutex thread_lock;
47 };
48 
49 /*
50  * Find a report, given the report's type and ID.  The ID can be specified
51  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
52  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
53  * given type which follows old_id.
54  */
55 static struct hid_report *
56 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
57 {
58 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
59 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
60 	struct hid_report_enum *report_enum;
61 	struct hid_report *report;
62 	struct list_head *list;
63 
64 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
65 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
66 		return NULL;
67 
68 	report_enum = hid->report_enum +
69 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
70 
71 	switch (flags) {
72 	case 0: /* Nothing to do -- report_id is already set correctly */
73 		break;
74 
75 	case HID_REPORT_ID_FIRST:
76 		if (list_empty(&report_enum->report_list))
77 			return NULL;
78 
79 		list = report_enum->report_list.next;
80 		report = list_entry(list, struct hid_report, list);
81 		rinfo->report_id = report->id;
82 		break;
83 
84 	case HID_REPORT_ID_NEXT:
85 		report = report_enum->report_id_hash[rid];
86 		if (!report)
87 			return NULL;
88 
89 		list = report->list.next;
90 		if (list == &report_enum->report_list)
91 			return NULL;
92 
93 		report = list_entry(list, struct hid_report, list);
94 		rinfo->report_id = report->id;
95 		break;
96 
97 	default:
98 		return NULL;
99 	}
100 
101 	return report_enum->report_id_hash[rinfo->report_id];
102 }
103 
104 /*
105  * Perform an exhaustive search of the report table for a usage, given its
106  * type and usage id.
107  */
108 static struct hid_field *
109 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
110 {
111 	int i, j;
112 	struct hid_report *report;
113 	struct hid_report_enum *report_enum;
114 	struct hid_field *field;
115 
116 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
117 	    uref->report_type > HID_REPORT_TYPE_MAX)
118 		return NULL;
119 
120 	report_enum = hid->report_enum +
121 		(uref->report_type - HID_REPORT_TYPE_MIN);
122 
123 	list_for_each_entry(report, &report_enum->report_list, list) {
124 		for (i = 0; i < report->maxfield; i++) {
125 			field = report->field[i];
126 			for (j = 0; j < field->maxusage; j++) {
127 				if (field->usage[j].hid == uref->usage_code) {
128 					uref->report_id = report->id;
129 					uref->field_index = i;
130 					uref->usage_index = j;
131 					return field;
132 				}
133 			}
134 		}
135 	}
136 
137 	return NULL;
138 }
139 
140 static void hiddev_send_event(struct hid_device *hid,
141 			      struct hiddev_usage_ref *uref)
142 {
143 	struct hiddev *hiddev = hid->hiddev;
144 	struct hiddev_list *list;
145 	unsigned long flags;
146 
147 	spin_lock_irqsave(&hiddev->list_lock, flags);
148 	list_for_each_entry(list, &hiddev->list, node) {
149 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
150 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
151 			list->buffer[list->head] = *uref;
152 			list->head = (list->head + 1) &
153 				(HIDDEV_BUFFER_SIZE - 1);
154 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
155 		}
156 	}
157 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
158 
159 	wake_up_interruptible(&hiddev->wait);
160 }
161 
162 /*
163  * This is where hid.c calls into hiddev to pass an event that occurred over
164  * the interrupt pipe
165  */
166 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
167 		      struct hid_usage *usage, __s32 value)
168 {
169 	unsigned type = field->report_type;
170 	struct hiddev_usage_ref uref;
171 
172 	uref.report_type =
173 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
174 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
175 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
176 	uref.report_id = field->report->id;
177 	uref.field_index = field->index;
178 	uref.usage_index = (usage - field->usage);
179 	uref.usage_code = usage->hid;
180 	uref.value = value;
181 
182 	hiddev_send_event(hid, &uref);
183 }
184 EXPORT_SYMBOL_GPL(hiddev_hid_event);
185 
186 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
187 {
188 	unsigned type = report->type;
189 	struct hiddev_usage_ref uref;
190 
191 	memset(&uref, 0, sizeof(uref));
192 	uref.report_type =
193 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
194 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
195 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
196 	uref.report_id = report->id;
197 	uref.field_index = HID_FIELD_INDEX_NONE;
198 
199 	hiddev_send_event(hid, &uref);
200 }
201 
202 /*
203  * fasync file op
204  */
205 static int hiddev_fasync(int fd, struct file *file, int on)
206 {
207 	struct hiddev_list *list = file->private_data;
208 
209 	return fasync_helper(fd, file, on, &list->fasync);
210 }
211 
212 
213 /*
214  * release file op
215  */
216 static int hiddev_release(struct inode * inode, struct file * file)
217 {
218 	struct hiddev_list *list = file->private_data;
219 	unsigned long flags;
220 
221 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
222 	list_del(&list->node);
223 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
224 
225 	mutex_lock(&list->hiddev->existancelock);
226 	if (!--list->hiddev->open) {
227 		if (list->hiddev->exist) {
228 			hid_hw_close(list->hiddev->hid);
229 			hid_hw_power(list->hiddev->hid, PM_HINT_NORMAL);
230 		} else {
231 			mutex_unlock(&list->hiddev->existancelock);
232 			kfree(list->hiddev);
233 			vfree(list);
234 			return 0;
235 		}
236 	}
237 
238 	mutex_unlock(&list->hiddev->existancelock);
239 	vfree(list);
240 
241 	return 0;
242 }
243 
244 /*
245  * open file op
246  */
247 static int hiddev_open(struct inode *inode, struct file *file)
248 {
249 	struct hiddev_list *list;
250 	struct usb_interface *intf;
251 	struct hid_device *hid;
252 	struct hiddev *hiddev;
253 	int res;
254 
255 	intf = usbhid_find_interface(iminor(inode));
256 	if (!intf)
257 		return -ENODEV;
258 	hid = usb_get_intfdata(intf);
259 	hiddev = hid->hiddev;
260 
261 	if (!(list = vzalloc(sizeof(struct hiddev_list))))
262 		return -ENOMEM;
263 	mutex_init(&list->thread_lock);
264 	list->hiddev = hiddev;
265 	file->private_data = list;
266 
267 	/*
268 	 * no need for locking because the USB major number
269 	 * is shared which usbcore guards against disconnect
270 	 */
271 	if (list->hiddev->exist) {
272 		if (!list->hiddev->open++) {
273 			res = hid_hw_open(hiddev->hid);
274 			if (res < 0)
275 				goto bail;
276 		}
277 	} else {
278 		res = -ENODEV;
279 		goto bail;
280 	}
281 
282 	spin_lock_irq(&list->hiddev->list_lock);
283 	list_add_tail(&list->node, &hiddev->list);
284 	spin_unlock_irq(&list->hiddev->list_lock);
285 
286 	mutex_lock(&hiddev->existancelock);
287 	/*
288 	 * recheck exist with existance lock held to
289 	 * avoid opening a disconnected device
290 	 */
291 	if (!list->hiddev->exist) {
292 		res = -ENODEV;
293 		goto bail_unlock;
294 	}
295 	if (!list->hiddev->open++)
296 		if (list->hiddev->exist) {
297 			struct hid_device *hid = hiddev->hid;
298 			res = hid_hw_power(hid, PM_HINT_FULLON);
299 			if (res < 0)
300 				goto bail_unlock;
301 			res = hid_hw_open(hid);
302 			if (res < 0)
303 				goto bail_normal_power;
304 		}
305 	mutex_unlock(&hiddev->existancelock);
306 	return 0;
307 bail_normal_power:
308 	hid_hw_power(hid, PM_HINT_NORMAL);
309 bail_unlock:
310 	mutex_unlock(&hiddev->existancelock);
311 
312 	spin_lock_irq(&list->hiddev->list_lock);
313 	list_del(&list->node);
314 	spin_unlock_irq(&list->hiddev->list_lock);
315 bail:
316 	file->private_data = NULL;
317 	vfree(list);
318 	return res;
319 }
320 
321 /*
322  * "write" file op
323  */
324 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
325 {
326 	return -EINVAL;
327 }
328 
329 /*
330  * "read" file op
331  */
332 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
333 {
334 	DEFINE_WAIT(wait);
335 	struct hiddev_list *list = file->private_data;
336 	int event_size;
337 	int retval;
338 
339 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
340 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
341 
342 	if (count < event_size)
343 		return 0;
344 
345 	/* lock against other threads */
346 	retval = mutex_lock_interruptible(&list->thread_lock);
347 	if (retval)
348 		return -ERESTARTSYS;
349 
350 	while (retval == 0) {
351 		if (list->head == list->tail) {
352 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
353 
354 			while (list->head == list->tail) {
355 				if (signal_pending(current)) {
356 					retval = -ERESTARTSYS;
357 					break;
358 				}
359 				if (!list->hiddev->exist) {
360 					retval = -EIO;
361 					break;
362 				}
363 				if (file->f_flags & O_NONBLOCK) {
364 					retval = -EAGAIN;
365 					break;
366 				}
367 
368 				/* let O_NONBLOCK tasks run */
369 				mutex_unlock(&list->thread_lock);
370 				schedule();
371 				if (mutex_lock_interruptible(&list->thread_lock)) {
372 					finish_wait(&list->hiddev->wait, &wait);
373 					return -EINTR;
374 				}
375 				set_current_state(TASK_INTERRUPTIBLE);
376 			}
377 			finish_wait(&list->hiddev->wait, &wait);
378 
379 		}
380 
381 		if (retval) {
382 			mutex_unlock(&list->thread_lock);
383 			return retval;
384 		}
385 
386 
387 		while (list->head != list->tail &&
388 		       retval + event_size <= count) {
389 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
390 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
391 					struct hiddev_event event;
392 
393 					event.hid = list->buffer[list->tail].usage_code;
394 					event.value = list->buffer[list->tail].value;
395 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
396 						mutex_unlock(&list->thread_lock);
397 						return -EFAULT;
398 					}
399 					retval += sizeof(struct hiddev_event);
400 				}
401 			} else {
402 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
403 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
404 
405 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
406 						mutex_unlock(&list->thread_lock);
407 						return -EFAULT;
408 					}
409 					retval += sizeof(struct hiddev_usage_ref);
410 				}
411 			}
412 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
413 		}
414 
415 	}
416 	mutex_unlock(&list->thread_lock);
417 
418 	return retval;
419 }
420 
421 /*
422  * "poll" file op
423  * No kernel lock - fine
424  */
425 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
426 {
427 	struct hiddev_list *list = file->private_data;
428 
429 	poll_wait(file, &list->hiddev->wait, wait);
430 	if (list->head != list->tail)
431 		return EPOLLIN | EPOLLRDNORM | EPOLLOUT;
432 	if (!list->hiddev->exist)
433 		return EPOLLERR | EPOLLHUP;
434 	return 0;
435 }
436 
437 /*
438  * "ioctl" file op
439  */
440 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
441 {
442 	struct hid_device *hid = hiddev->hid;
443 	struct hiddev_report_info rinfo;
444 	struct hiddev_usage_ref_multi *uref_multi = NULL;
445 	struct hiddev_usage_ref *uref;
446 	struct hid_report *report;
447 	struct hid_field *field;
448 	int i;
449 
450 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
451 	if (!uref_multi)
452 		return -ENOMEM;
453 	uref = &uref_multi->uref;
454 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
455 		if (copy_from_user(uref_multi, user_arg,
456 				   sizeof(*uref_multi)))
457 			goto fault;
458 	} else {
459 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
460 			goto fault;
461 	}
462 
463 	switch (cmd) {
464 	case HIDIOCGUCODE:
465 		rinfo.report_type = uref->report_type;
466 		rinfo.report_id = uref->report_id;
467 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
468 			goto inval;
469 
470 		if (uref->field_index >= report->maxfield)
471 			goto inval;
472 		uref->field_index = array_index_nospec(uref->field_index,
473 						       report->maxfield);
474 
475 		field = report->field[uref->field_index];
476 		if (uref->usage_index >= field->maxusage)
477 			goto inval;
478 		uref->usage_index = array_index_nospec(uref->usage_index,
479 						       field->maxusage);
480 
481 		uref->usage_code = field->usage[uref->usage_index].hid;
482 
483 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
484 			goto fault;
485 
486 		goto goodreturn;
487 
488 	default:
489 		if (cmd != HIDIOCGUSAGE &&
490 		    cmd != HIDIOCGUSAGES &&
491 		    uref->report_type == HID_REPORT_TYPE_INPUT)
492 			goto inval;
493 
494 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
495 			field = hiddev_lookup_usage(hid, uref);
496 			if (field == NULL)
497 				goto inval;
498 		} else {
499 			rinfo.report_type = uref->report_type;
500 			rinfo.report_id = uref->report_id;
501 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
502 				goto inval;
503 
504 			if (uref->field_index >= report->maxfield)
505 				goto inval;
506 			uref->field_index = array_index_nospec(uref->field_index,
507 							       report->maxfield);
508 
509 			field = report->field[uref->field_index];
510 
511 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
512 				if (uref->usage_index >= field->maxusage)
513 					goto inval;
514 				uref->usage_index =
515 					array_index_nospec(uref->usage_index,
516 							   field->maxusage);
517 			} else if (uref->usage_index >= field->report_count)
518 				goto inval;
519 		}
520 
521 		if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
522 			if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
523 			    uref->usage_index + uref_multi->num_values >
524 			    field->report_count)
525 				goto inval;
526 
527 			uref->usage_index =
528 				array_index_nospec(uref->usage_index,
529 						   field->report_count -
530 						   uref_multi->num_values);
531 		}
532 
533 		switch (cmd) {
534 		case HIDIOCGUSAGE:
535 			uref->value = field->value[uref->usage_index];
536 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
537 				goto fault;
538 			goto goodreturn;
539 
540 		case HIDIOCSUSAGE:
541 			field->value[uref->usage_index] = uref->value;
542 			goto goodreturn;
543 
544 		case HIDIOCGCOLLECTIONINDEX:
545 			i = field->usage[uref->usage_index].collection_index;
546 			kfree(uref_multi);
547 			return i;
548 		case HIDIOCGUSAGES:
549 			for (i = 0; i < uref_multi->num_values; i++)
550 				uref_multi->values[i] =
551 				    field->value[uref->usage_index + i];
552 			if (copy_to_user(user_arg, uref_multi,
553 					 sizeof(*uref_multi)))
554 				goto fault;
555 			goto goodreturn;
556 		case HIDIOCSUSAGES:
557 			for (i = 0; i < uref_multi->num_values; i++)
558 				field->value[uref->usage_index + i] =
559 				    uref_multi->values[i];
560 			goto goodreturn;
561 		}
562 
563 goodreturn:
564 		kfree(uref_multi);
565 		return 0;
566 fault:
567 		kfree(uref_multi);
568 		return -EFAULT;
569 inval:
570 		kfree(uref_multi);
571 		return -EINVAL;
572 	}
573 }
574 
575 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
576 {
577 	struct hid_device *hid = hiddev->hid;
578 	struct usb_device *dev = hid_to_usb_dev(hid);
579 	int idx, len;
580 	char *buf;
581 
582 	if (get_user(idx, (int __user *)user_arg))
583 		return -EFAULT;
584 
585 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
586 		return -ENOMEM;
587 
588 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
589 		kfree(buf);
590 		return -EINVAL;
591 	}
592 
593 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
594 		kfree(buf);
595 		return -EFAULT;
596 	}
597 
598 	kfree(buf);
599 
600 	return len;
601 }
602 
603 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
604 {
605 	struct hiddev_list *list = file->private_data;
606 	struct hiddev *hiddev = list->hiddev;
607 	struct hid_device *hid;
608 	struct hiddev_collection_info cinfo;
609 	struct hiddev_report_info rinfo;
610 	struct hiddev_field_info finfo;
611 	struct hiddev_devinfo dinfo;
612 	struct hid_report *report;
613 	struct hid_field *field;
614 	void __user *user_arg = (void __user *)arg;
615 	int i, r = -EINVAL;
616 
617 	/* Called without BKL by compat methods so no BKL taken */
618 
619 	mutex_lock(&hiddev->existancelock);
620 	if (!hiddev->exist) {
621 		r = -ENODEV;
622 		goto ret_unlock;
623 	}
624 
625 	hid = hiddev->hid;
626 
627 	switch (cmd) {
628 
629 	case HIDIOCGVERSION:
630 		r = put_user(HID_VERSION, (int __user *)arg) ?
631 			-EFAULT : 0;
632 		break;
633 
634 	case HIDIOCAPPLICATION:
635 		if (arg >= hid->maxapplication)
636 			break;
637 
638 		for (i = 0; i < hid->maxcollection; i++)
639 			if (hid->collection[i].type ==
640 			    HID_COLLECTION_APPLICATION && arg-- == 0)
641 				break;
642 
643 		if (i < hid->maxcollection)
644 			r = hid->collection[i].usage;
645 		break;
646 
647 	case HIDIOCGDEVINFO:
648 		{
649 			struct usb_device *dev = hid_to_usb_dev(hid);
650 			struct usbhid_device *usbhid = hid->driver_data;
651 
652 			memset(&dinfo, 0, sizeof(dinfo));
653 
654 			dinfo.bustype = BUS_USB;
655 			dinfo.busnum = dev->bus->busnum;
656 			dinfo.devnum = dev->devnum;
657 			dinfo.ifnum = usbhid->ifnum;
658 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
659 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
660 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
661 			dinfo.num_applications = hid->maxapplication;
662 
663 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
664 				-EFAULT : 0;
665 			break;
666 		}
667 
668 	case HIDIOCGFLAG:
669 		r = put_user(list->flags, (int __user *)arg) ?
670 			-EFAULT : 0;
671 		break;
672 
673 	case HIDIOCSFLAG:
674 		{
675 			int newflags;
676 
677 			if (get_user(newflags, (int __user *)arg)) {
678 				r = -EFAULT;
679 				break;
680 			}
681 
682 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
683 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
684 			     (newflags & HIDDEV_FLAG_UREF) == 0))
685 				break;
686 
687 			list->flags = newflags;
688 
689 			r = 0;
690 			break;
691 		}
692 
693 	case HIDIOCGSTRING:
694 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
695 		break;
696 
697 	case HIDIOCINITREPORT:
698 		usbhid_init_reports(hid);
699 		hiddev->initialized = true;
700 		r = 0;
701 		break;
702 
703 	case HIDIOCGREPORT:
704 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
705 			r = -EFAULT;
706 			break;
707 		}
708 
709 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
710 			break;
711 
712 		report = hiddev_lookup_report(hid, &rinfo);
713 		if (report == NULL)
714 			break;
715 
716 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
717 		hid_hw_wait(hid);
718 
719 		r = 0;
720 		break;
721 
722 	case HIDIOCSREPORT:
723 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
724 			r = -EFAULT;
725 			break;
726 		}
727 
728 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
729 			break;
730 
731 		report = hiddev_lookup_report(hid, &rinfo);
732 		if (report == NULL)
733 			break;
734 
735 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
736 		hid_hw_wait(hid);
737 
738 		r = 0;
739 		break;
740 
741 	case HIDIOCGREPORTINFO:
742 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
743 			r = -EFAULT;
744 			break;
745 		}
746 
747 		report = hiddev_lookup_report(hid, &rinfo);
748 		if (report == NULL)
749 			break;
750 
751 		rinfo.num_fields = report->maxfield;
752 
753 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
754 			-EFAULT : 0;
755 		break;
756 
757 	case HIDIOCGFIELDINFO:
758 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
759 			r = -EFAULT;
760 			break;
761 		}
762 
763 		rinfo.report_type = finfo.report_type;
764 		rinfo.report_id = finfo.report_id;
765 
766 		report = hiddev_lookup_report(hid, &rinfo);
767 		if (report == NULL)
768 			break;
769 
770 		if (finfo.field_index >= report->maxfield)
771 			break;
772 		finfo.field_index = array_index_nospec(finfo.field_index,
773 						       report->maxfield);
774 
775 		field = report->field[finfo.field_index];
776 		memset(&finfo, 0, sizeof(finfo));
777 		finfo.report_type = rinfo.report_type;
778 		finfo.report_id = rinfo.report_id;
779 		finfo.field_index = field->report_count - 1;
780 		finfo.maxusage = field->maxusage;
781 		finfo.flags = field->flags;
782 		finfo.physical = field->physical;
783 		finfo.logical = field->logical;
784 		finfo.application = field->application;
785 		finfo.logical_minimum = field->logical_minimum;
786 		finfo.logical_maximum = field->logical_maximum;
787 		finfo.physical_minimum = field->physical_minimum;
788 		finfo.physical_maximum = field->physical_maximum;
789 		finfo.unit_exponent = field->unit_exponent;
790 		finfo.unit = field->unit;
791 
792 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
793 			-EFAULT : 0;
794 		break;
795 
796 	case HIDIOCGUCODE:
797 		/* fall through */
798 	case HIDIOCGUSAGE:
799 	case HIDIOCSUSAGE:
800 	case HIDIOCGUSAGES:
801 	case HIDIOCSUSAGES:
802 	case HIDIOCGCOLLECTIONINDEX:
803 		if (!hiddev->initialized) {
804 			usbhid_init_reports(hid);
805 			hiddev->initialized = true;
806 		}
807 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
808 		break;
809 
810 	case HIDIOCGCOLLECTIONINFO:
811 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
812 			r = -EFAULT;
813 			break;
814 		}
815 
816 		if (cinfo.index >= hid->maxcollection)
817 			break;
818 		cinfo.index = array_index_nospec(cinfo.index,
819 						 hid->maxcollection);
820 
821 		cinfo.type = hid->collection[cinfo.index].type;
822 		cinfo.usage = hid->collection[cinfo.index].usage;
823 		cinfo.level = hid->collection[cinfo.index].level;
824 
825 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
826 			-EFAULT : 0;
827 		break;
828 
829 	default:
830 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
831 			break;
832 
833 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
834 			int len = strlen(hid->name) + 1;
835 			if (len > _IOC_SIZE(cmd))
836 				 len = _IOC_SIZE(cmd);
837 			r = copy_to_user(user_arg, hid->name, len) ?
838 				-EFAULT : len;
839 			break;
840 		}
841 
842 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
843 			int len = strlen(hid->phys) + 1;
844 			if (len > _IOC_SIZE(cmd))
845 				len = _IOC_SIZE(cmd);
846 			r = copy_to_user(user_arg, hid->phys, len) ?
847 				-EFAULT : len;
848 			break;
849 		}
850 	}
851 
852 ret_unlock:
853 	mutex_unlock(&hiddev->existancelock);
854 	return r;
855 }
856 
857 static const struct file_operations hiddev_fops = {
858 	.owner =	THIS_MODULE,
859 	.read =		hiddev_read,
860 	.write =	hiddev_write,
861 	.poll =		hiddev_poll,
862 	.open =		hiddev_open,
863 	.release =	hiddev_release,
864 	.unlocked_ioctl =	hiddev_ioctl,
865 	.fasync =	hiddev_fasync,
866 	.compat_ioctl	= compat_ptr_ioctl,
867 	.llseek		= noop_llseek,
868 };
869 
870 static char *hiddev_devnode(struct device *dev, umode_t *mode)
871 {
872 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
873 }
874 
875 static struct usb_class_driver hiddev_class = {
876 	.name =		"hiddev%d",
877 	.devnode =	hiddev_devnode,
878 	.fops =		&hiddev_fops,
879 	.minor_base =	HIDDEV_MINOR_BASE,
880 };
881 
882 /*
883  * This is where hid.c calls us to connect a hid device to the hiddev driver
884  */
885 int hiddev_connect(struct hid_device *hid, unsigned int force)
886 {
887 	struct hiddev *hiddev;
888 	struct usbhid_device *usbhid = hid->driver_data;
889 	int retval;
890 
891 	if (!force) {
892 		unsigned int i;
893 		for (i = 0; i < hid->maxcollection; i++)
894 			if (hid->collection[i].type ==
895 			    HID_COLLECTION_APPLICATION &&
896 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
897 				break;
898 
899 		if (i == hid->maxcollection)
900 			return -1;
901 	}
902 
903 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
904 		return -1;
905 
906 	init_waitqueue_head(&hiddev->wait);
907 	INIT_LIST_HEAD(&hiddev->list);
908 	spin_lock_init(&hiddev->list_lock);
909 	mutex_init(&hiddev->existancelock);
910 	hid->hiddev = hiddev;
911 	hiddev->hid = hid;
912 	hiddev->exist = 1;
913 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
914 	if (retval) {
915 		hid_err(hid, "Not able to get a minor for this device\n");
916 		hid->hiddev = NULL;
917 		kfree(hiddev);
918 		return -1;
919 	}
920 
921 	/*
922 	 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
923 	 * the reports.
924 	 */
925 	hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
926 
927 	hiddev->minor = usbhid->intf->minor;
928 
929 	return 0;
930 }
931 
932 /*
933  * This is where hid.c calls us to disconnect a hiddev device from the
934  * corresponding hid device (usually because the usb device has disconnected)
935  */
936 static struct usb_class_driver hiddev_class;
937 void hiddev_disconnect(struct hid_device *hid)
938 {
939 	struct hiddev *hiddev = hid->hiddev;
940 	struct usbhid_device *usbhid = hid->driver_data;
941 
942 	usb_deregister_dev(usbhid->intf, &hiddev_class);
943 
944 	mutex_lock(&hiddev->existancelock);
945 	hiddev->exist = 0;
946 
947 	if (hiddev->open) {
948 		mutex_unlock(&hiddev->existancelock);
949 		hid_hw_close(hiddev->hid);
950 		wake_up_interruptible(&hiddev->wait);
951 	} else {
952 		mutex_unlock(&hiddev->existancelock);
953 		kfree(hiddev);
954 	}
955 }
956