xref: /openbmc/linux/drivers/hid/usbhid/hiddev.c (revision 43ffe817)
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 static int __hiddev_open(struct hiddev *hiddev, struct file *file)
245 {
246 	struct hiddev_list *list;
247 	int error;
248 
249 	lockdep_assert_held(&hiddev->existancelock);
250 
251 	list = vzalloc(sizeof(*list));
252 	if (!list)
253 		return -ENOMEM;
254 
255 	mutex_init(&list->thread_lock);
256 	list->hiddev = hiddev;
257 
258 	if (!hiddev->open++) {
259 		error = hid_hw_power(hiddev->hid, PM_HINT_FULLON);
260 		if (error < 0)
261 			goto err_drop_count;
262 
263 		error = hid_hw_open(hiddev->hid);
264 		if (error < 0)
265 			goto err_normal_power;
266 	}
267 
268 	spin_lock_irq(&hiddev->list_lock);
269 	list_add_tail(&list->node, &hiddev->list);
270 	spin_unlock_irq(&hiddev->list_lock);
271 
272 	file->private_data = list;
273 
274 	return 0;
275 
276 err_normal_power:
277 	hid_hw_power(hiddev->hid, PM_HINT_NORMAL);
278 err_drop_count:
279 	hiddev->open--;
280 	vfree(list);
281 	return error;
282 }
283 
284 /*
285  * open file op
286  */
287 static int hiddev_open(struct inode *inode, struct file *file)
288 {
289 	struct usb_interface *intf;
290 	struct hid_device *hid;
291 	struct hiddev *hiddev;
292 	int res;
293 
294 	intf = usbhid_find_interface(iminor(inode));
295 	if (!intf)
296 		return -ENODEV;
297 
298 	hid = usb_get_intfdata(intf);
299 	hiddev = hid->hiddev;
300 
301 	mutex_lock(&hiddev->existancelock);
302 	res = hiddev->exist ? __hiddev_open(hiddev, file) : -ENODEV;
303 	mutex_unlock(&hiddev->existancelock);
304 
305 	return res;
306 }
307 
308 /*
309  * "write" file op
310  */
311 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
312 {
313 	return -EINVAL;
314 }
315 
316 /*
317  * "read" file op
318  */
319 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
320 {
321 	DEFINE_WAIT(wait);
322 	struct hiddev_list *list = file->private_data;
323 	int event_size;
324 	int retval;
325 
326 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
327 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
328 
329 	if (count < event_size)
330 		return 0;
331 
332 	/* lock against other threads */
333 	retval = mutex_lock_interruptible(&list->thread_lock);
334 	if (retval)
335 		return -ERESTARTSYS;
336 
337 	while (retval == 0) {
338 		if (list->head == list->tail) {
339 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
340 
341 			while (list->head == list->tail) {
342 				if (signal_pending(current)) {
343 					retval = -ERESTARTSYS;
344 					break;
345 				}
346 				if (!list->hiddev->exist) {
347 					retval = -EIO;
348 					break;
349 				}
350 				if (file->f_flags & O_NONBLOCK) {
351 					retval = -EAGAIN;
352 					break;
353 				}
354 
355 				/* let O_NONBLOCK tasks run */
356 				mutex_unlock(&list->thread_lock);
357 				schedule();
358 				if (mutex_lock_interruptible(&list->thread_lock)) {
359 					finish_wait(&list->hiddev->wait, &wait);
360 					return -EINTR;
361 				}
362 				set_current_state(TASK_INTERRUPTIBLE);
363 			}
364 			finish_wait(&list->hiddev->wait, &wait);
365 
366 		}
367 
368 		if (retval) {
369 			mutex_unlock(&list->thread_lock);
370 			return retval;
371 		}
372 
373 
374 		while (list->head != list->tail &&
375 		       retval + event_size <= count) {
376 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
377 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
378 					struct hiddev_event event;
379 
380 					event.hid = list->buffer[list->tail].usage_code;
381 					event.value = list->buffer[list->tail].value;
382 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
383 						mutex_unlock(&list->thread_lock);
384 						return -EFAULT;
385 					}
386 					retval += sizeof(struct hiddev_event);
387 				}
388 			} else {
389 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
390 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
391 
392 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
393 						mutex_unlock(&list->thread_lock);
394 						return -EFAULT;
395 					}
396 					retval += sizeof(struct hiddev_usage_ref);
397 				}
398 			}
399 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
400 		}
401 
402 	}
403 	mutex_unlock(&list->thread_lock);
404 
405 	return retval;
406 }
407 
408 /*
409  * "poll" file op
410  * No kernel lock - fine
411  */
412 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
413 {
414 	struct hiddev_list *list = file->private_data;
415 
416 	poll_wait(file, &list->hiddev->wait, wait);
417 	if (list->head != list->tail)
418 		return EPOLLIN | EPOLLRDNORM | EPOLLOUT;
419 	if (!list->hiddev->exist)
420 		return EPOLLERR | EPOLLHUP;
421 	return 0;
422 }
423 
424 /*
425  * "ioctl" file op
426  */
427 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
428 {
429 	struct hid_device *hid = hiddev->hid;
430 	struct hiddev_report_info rinfo;
431 	struct hiddev_usage_ref_multi *uref_multi = NULL;
432 	struct hiddev_usage_ref *uref;
433 	struct hid_report *report;
434 	struct hid_field *field;
435 	int i;
436 
437 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
438 	if (!uref_multi)
439 		return -ENOMEM;
440 	uref = &uref_multi->uref;
441 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
442 		if (copy_from_user(uref_multi, user_arg,
443 				   sizeof(*uref_multi)))
444 			goto fault;
445 	} else {
446 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
447 			goto fault;
448 	}
449 
450 	switch (cmd) {
451 	case HIDIOCGUCODE:
452 		rinfo.report_type = uref->report_type;
453 		rinfo.report_id = uref->report_id;
454 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
455 			goto inval;
456 
457 		if (uref->field_index >= report->maxfield)
458 			goto inval;
459 		uref->field_index = array_index_nospec(uref->field_index,
460 						       report->maxfield);
461 
462 		field = report->field[uref->field_index];
463 		if (uref->usage_index >= field->maxusage)
464 			goto inval;
465 		uref->usage_index = array_index_nospec(uref->usage_index,
466 						       field->maxusage);
467 
468 		uref->usage_code = field->usage[uref->usage_index].hid;
469 
470 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
471 			goto fault;
472 
473 		goto goodreturn;
474 
475 	default:
476 		if (cmd != HIDIOCGUSAGE &&
477 		    cmd != HIDIOCGUSAGES &&
478 		    uref->report_type == HID_REPORT_TYPE_INPUT)
479 			goto inval;
480 
481 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
482 			field = hiddev_lookup_usage(hid, uref);
483 			if (field == NULL)
484 				goto inval;
485 		} else {
486 			rinfo.report_type = uref->report_type;
487 			rinfo.report_id = uref->report_id;
488 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
489 				goto inval;
490 
491 			if (uref->field_index >= report->maxfield)
492 				goto inval;
493 			uref->field_index = array_index_nospec(uref->field_index,
494 							       report->maxfield);
495 
496 			field = report->field[uref->field_index];
497 
498 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
499 				if (uref->usage_index >= field->maxusage)
500 					goto inval;
501 				uref->usage_index =
502 					array_index_nospec(uref->usage_index,
503 							   field->maxusage);
504 			} else if (uref->usage_index >= field->report_count)
505 				goto inval;
506 		}
507 
508 		if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
509 			if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
510 			    uref->usage_index + uref_multi->num_values >
511 			    field->report_count)
512 				goto inval;
513 
514 			uref->usage_index =
515 				array_index_nospec(uref->usage_index,
516 						   field->report_count -
517 						   uref_multi->num_values);
518 		}
519 
520 		switch (cmd) {
521 		case HIDIOCGUSAGE:
522 			if (uref->usage_index >= field->report_count)
523 				goto inval;
524 			uref->value = field->value[uref->usage_index];
525 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
526 				goto fault;
527 			goto goodreturn;
528 
529 		case HIDIOCSUSAGE:
530 			if (uref->usage_index >= field->report_count)
531 				goto inval;
532 			field->value[uref->usage_index] = uref->value;
533 			goto goodreturn;
534 
535 		case HIDIOCGCOLLECTIONINDEX:
536 			i = field->usage[uref->usage_index].collection_index;
537 			kfree(uref_multi);
538 			return i;
539 		case HIDIOCGUSAGES:
540 			for (i = 0; i < uref_multi->num_values; i++)
541 				uref_multi->values[i] =
542 				    field->value[uref->usage_index + i];
543 			if (copy_to_user(user_arg, uref_multi,
544 					 sizeof(*uref_multi)))
545 				goto fault;
546 			goto goodreturn;
547 		case HIDIOCSUSAGES:
548 			for (i = 0; i < uref_multi->num_values; i++)
549 				field->value[uref->usage_index + i] =
550 				    uref_multi->values[i];
551 			goto goodreturn;
552 		}
553 
554 goodreturn:
555 		kfree(uref_multi);
556 		return 0;
557 fault:
558 		kfree(uref_multi);
559 		return -EFAULT;
560 inval:
561 		kfree(uref_multi);
562 		return -EINVAL;
563 	}
564 }
565 
566 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
567 {
568 	struct hid_device *hid = hiddev->hid;
569 	struct usb_device *dev = hid_to_usb_dev(hid);
570 	int idx, len;
571 	char *buf;
572 
573 	if (get_user(idx, (int __user *)user_arg))
574 		return -EFAULT;
575 
576 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
577 		return -ENOMEM;
578 
579 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
580 		kfree(buf);
581 		return -EINVAL;
582 	}
583 
584 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
585 		kfree(buf);
586 		return -EFAULT;
587 	}
588 
589 	kfree(buf);
590 
591 	return len;
592 }
593 
594 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
595 {
596 	struct hiddev_list *list = file->private_data;
597 	struct hiddev *hiddev = list->hiddev;
598 	struct hid_device *hid;
599 	struct hiddev_collection_info cinfo;
600 	struct hiddev_report_info rinfo;
601 	struct hiddev_field_info finfo;
602 	struct hiddev_devinfo dinfo;
603 	struct hid_report *report;
604 	struct hid_field *field;
605 	void __user *user_arg = (void __user *)arg;
606 	int i, r = -EINVAL;
607 
608 	/* Called without BKL by compat methods so no BKL taken */
609 
610 	mutex_lock(&hiddev->existancelock);
611 	if (!hiddev->exist) {
612 		r = -ENODEV;
613 		goto ret_unlock;
614 	}
615 
616 	hid = hiddev->hid;
617 
618 	switch (cmd) {
619 
620 	case HIDIOCGVERSION:
621 		r = put_user(HID_VERSION, (int __user *)arg) ?
622 			-EFAULT : 0;
623 		break;
624 
625 	case HIDIOCAPPLICATION:
626 		if (arg >= hid->maxapplication)
627 			break;
628 
629 		for (i = 0; i < hid->maxcollection; i++)
630 			if (hid->collection[i].type ==
631 			    HID_COLLECTION_APPLICATION && arg-- == 0)
632 				break;
633 
634 		if (i < hid->maxcollection)
635 			r = hid->collection[i].usage;
636 		break;
637 
638 	case HIDIOCGDEVINFO:
639 		{
640 			struct usb_device *dev = hid_to_usb_dev(hid);
641 			struct usbhid_device *usbhid = hid->driver_data;
642 
643 			memset(&dinfo, 0, sizeof(dinfo));
644 
645 			dinfo.bustype = BUS_USB;
646 			dinfo.busnum = dev->bus->busnum;
647 			dinfo.devnum = dev->devnum;
648 			dinfo.ifnum = usbhid->ifnum;
649 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
650 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
651 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
652 			dinfo.num_applications = hid->maxapplication;
653 
654 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
655 				-EFAULT : 0;
656 			break;
657 		}
658 
659 	case HIDIOCGFLAG:
660 		r = put_user(list->flags, (int __user *)arg) ?
661 			-EFAULT : 0;
662 		break;
663 
664 	case HIDIOCSFLAG:
665 		{
666 			int newflags;
667 
668 			if (get_user(newflags, (int __user *)arg)) {
669 				r = -EFAULT;
670 				break;
671 			}
672 
673 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
674 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
675 			     (newflags & HIDDEV_FLAG_UREF) == 0))
676 				break;
677 
678 			list->flags = newflags;
679 
680 			r = 0;
681 			break;
682 		}
683 
684 	case HIDIOCGSTRING:
685 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
686 		break;
687 
688 	case HIDIOCINITREPORT:
689 		usbhid_init_reports(hid);
690 		hiddev->initialized = true;
691 		r = 0;
692 		break;
693 
694 	case HIDIOCGREPORT:
695 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
696 			r = -EFAULT;
697 			break;
698 		}
699 
700 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
701 			break;
702 
703 		report = hiddev_lookup_report(hid, &rinfo);
704 		if (report == NULL)
705 			break;
706 
707 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
708 		hid_hw_wait(hid);
709 
710 		r = 0;
711 		break;
712 
713 	case HIDIOCSREPORT:
714 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
715 			r = -EFAULT;
716 			break;
717 		}
718 
719 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
720 			break;
721 
722 		report = hiddev_lookup_report(hid, &rinfo);
723 		if (report == NULL)
724 			break;
725 
726 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
727 		hid_hw_wait(hid);
728 
729 		r = 0;
730 		break;
731 
732 	case HIDIOCGREPORTINFO:
733 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
734 			r = -EFAULT;
735 			break;
736 		}
737 
738 		report = hiddev_lookup_report(hid, &rinfo);
739 		if (report == NULL)
740 			break;
741 
742 		rinfo.num_fields = report->maxfield;
743 
744 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
745 			-EFAULT : 0;
746 		break;
747 
748 	case HIDIOCGFIELDINFO:
749 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
750 			r = -EFAULT;
751 			break;
752 		}
753 
754 		rinfo.report_type = finfo.report_type;
755 		rinfo.report_id = finfo.report_id;
756 
757 		report = hiddev_lookup_report(hid, &rinfo);
758 		if (report == NULL)
759 			break;
760 
761 		if (finfo.field_index >= report->maxfield)
762 			break;
763 		finfo.field_index = array_index_nospec(finfo.field_index,
764 						       report->maxfield);
765 
766 		field = report->field[finfo.field_index];
767 		memset(&finfo, 0, sizeof(finfo));
768 		finfo.report_type = rinfo.report_type;
769 		finfo.report_id = rinfo.report_id;
770 		finfo.field_index = field->report_count - 1;
771 		finfo.maxusage = field->maxusage;
772 		finfo.flags = field->flags;
773 		finfo.physical = field->physical;
774 		finfo.logical = field->logical;
775 		finfo.application = field->application;
776 		finfo.logical_minimum = field->logical_minimum;
777 		finfo.logical_maximum = field->logical_maximum;
778 		finfo.physical_minimum = field->physical_minimum;
779 		finfo.physical_maximum = field->physical_maximum;
780 		finfo.unit_exponent = field->unit_exponent;
781 		finfo.unit = field->unit;
782 
783 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
784 			-EFAULT : 0;
785 		break;
786 
787 	case HIDIOCGUCODE:
788 	case HIDIOCGUSAGE:
789 	case HIDIOCSUSAGE:
790 	case HIDIOCGUSAGES:
791 	case HIDIOCSUSAGES:
792 	case HIDIOCGCOLLECTIONINDEX:
793 		if (!hiddev->initialized) {
794 			usbhid_init_reports(hid);
795 			hiddev->initialized = true;
796 		}
797 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
798 		break;
799 
800 	case HIDIOCGCOLLECTIONINFO:
801 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
802 			r = -EFAULT;
803 			break;
804 		}
805 
806 		if (cinfo.index >= hid->maxcollection)
807 			break;
808 		cinfo.index = array_index_nospec(cinfo.index,
809 						 hid->maxcollection);
810 
811 		cinfo.type = hid->collection[cinfo.index].type;
812 		cinfo.usage = hid->collection[cinfo.index].usage;
813 		cinfo.level = hid->collection[cinfo.index].level;
814 
815 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
816 			-EFAULT : 0;
817 		break;
818 
819 	default:
820 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
821 			break;
822 
823 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
824 			int len = strlen(hid->name) + 1;
825 			if (len > _IOC_SIZE(cmd))
826 				 len = _IOC_SIZE(cmd);
827 			r = copy_to_user(user_arg, hid->name, len) ?
828 				-EFAULT : len;
829 			break;
830 		}
831 
832 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
833 			int len = strlen(hid->phys) + 1;
834 			if (len > _IOC_SIZE(cmd))
835 				len = _IOC_SIZE(cmd);
836 			r = copy_to_user(user_arg, hid->phys, len) ?
837 				-EFAULT : len;
838 			break;
839 		}
840 	}
841 
842 ret_unlock:
843 	mutex_unlock(&hiddev->existancelock);
844 	return r;
845 }
846 
847 static const struct file_operations hiddev_fops = {
848 	.owner =	THIS_MODULE,
849 	.read =		hiddev_read,
850 	.write =	hiddev_write,
851 	.poll =		hiddev_poll,
852 	.open =		hiddev_open,
853 	.release =	hiddev_release,
854 	.unlocked_ioctl =	hiddev_ioctl,
855 	.fasync =	hiddev_fasync,
856 	.compat_ioctl	= compat_ptr_ioctl,
857 	.llseek		= noop_llseek,
858 };
859 
860 static char *hiddev_devnode(struct device *dev, umode_t *mode)
861 {
862 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
863 }
864 
865 static struct usb_class_driver hiddev_class = {
866 	.name =		"hiddev%d",
867 	.devnode =	hiddev_devnode,
868 	.fops =		&hiddev_fops,
869 	.minor_base =	HIDDEV_MINOR_BASE,
870 };
871 
872 /*
873  * This is where hid.c calls us to connect a hid device to the hiddev driver
874  */
875 int hiddev_connect(struct hid_device *hid, unsigned int force)
876 {
877 	struct hiddev *hiddev;
878 	struct usbhid_device *usbhid = hid->driver_data;
879 	int retval;
880 
881 	if (!force) {
882 		unsigned int i;
883 		for (i = 0; i < hid->maxcollection; i++)
884 			if (hid->collection[i].type ==
885 			    HID_COLLECTION_APPLICATION &&
886 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
887 				break;
888 
889 		if (i == hid->maxcollection)
890 			return -1;
891 	}
892 
893 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
894 		return -1;
895 
896 	init_waitqueue_head(&hiddev->wait);
897 	INIT_LIST_HEAD(&hiddev->list);
898 	spin_lock_init(&hiddev->list_lock);
899 	mutex_init(&hiddev->existancelock);
900 	hid->hiddev = hiddev;
901 	hiddev->hid = hid;
902 	hiddev->exist = 1;
903 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
904 	if (retval) {
905 		hid_err(hid, "Not able to get a minor for this device\n");
906 		hid->hiddev = NULL;
907 		kfree(hiddev);
908 		return -1;
909 	}
910 
911 	/*
912 	 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
913 	 * the reports.
914 	 */
915 	hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
916 
917 	hiddev->minor = usbhid->intf->minor;
918 
919 	return 0;
920 }
921 
922 /*
923  * This is where hid.c calls us to disconnect a hiddev device from the
924  * corresponding hid device (usually because the usb device has disconnected)
925  */
926 static struct usb_class_driver hiddev_class;
927 void hiddev_disconnect(struct hid_device *hid)
928 {
929 	struct hiddev *hiddev = hid->hiddev;
930 	struct usbhid_device *usbhid = hid->driver_data;
931 
932 	usb_deregister_dev(usbhid->intf, &hiddev_class);
933 
934 	mutex_lock(&hiddev->existancelock);
935 	hiddev->exist = 0;
936 
937 	if (hiddev->open) {
938 		hid_hw_close(hiddev->hid);
939 		wake_up_interruptible(&hiddev->wait);
940 		mutex_unlock(&hiddev->existancelock);
941 	} else {
942 		mutex_unlock(&hiddev->existancelock);
943 		kfree(hiddev);
944 	}
945 }
946