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1 /*
2  *  Copyright (c) 2001 Paul Stewart
3  *  Copyright (c) 2001 Vojtech Pavlik
4  *
5  *  HID char devices, giving access to raw HID device events.
6  *
7  */
8 
9 /*
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  *
24  * Should you need to contact me, the author, you can do so either by
25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
26  */
27 
28 #include <linux/poll.h>
29 #include <linux/slab.h>
30 #include <linux/sched/signal.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/input.h>
34 #include <linux/usb.h>
35 #include <linux/hid.h>
36 #include <linux/hiddev.h>
37 #include <linux/compat.h>
38 #include <linux/vmalloc.h>
39 #include <linux/nospec.h>
40 #include "usbhid.h"
41 
42 #ifdef CONFIG_USB_DYNAMIC_MINORS
43 #define HIDDEV_MINOR_BASE	0
44 #define HIDDEV_MINORS		256
45 #else
46 #define HIDDEV_MINOR_BASE	96
47 #define HIDDEV_MINORS		16
48 #endif
49 #define HIDDEV_BUFFER_SIZE	2048
50 
51 struct hiddev_list {
52 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
53 	int head;
54 	int tail;
55 	unsigned flags;
56 	struct fasync_struct *fasync;
57 	struct hiddev *hiddev;
58 	struct list_head node;
59 	struct mutex thread_lock;
60 };
61 
62 /*
63  * Find a report, given the report's type and ID.  The ID can be specified
64  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
65  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
66  * given type which follows old_id.
67  */
68 static struct hid_report *
hiddev_lookup_report(struct hid_device * hid,struct hiddev_report_info * rinfo)69 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
70 {
71 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
72 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
73 	struct hid_report_enum *report_enum;
74 	struct hid_report *report;
75 	struct list_head *list;
76 
77 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
78 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
79 		return NULL;
80 
81 	report_enum = hid->report_enum +
82 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
83 
84 	switch (flags) {
85 	case 0: /* Nothing to do -- report_id is already set correctly */
86 		break;
87 
88 	case HID_REPORT_ID_FIRST:
89 		if (list_empty(&report_enum->report_list))
90 			return NULL;
91 
92 		list = report_enum->report_list.next;
93 		report = list_entry(list, struct hid_report, list);
94 		rinfo->report_id = report->id;
95 		break;
96 
97 	case HID_REPORT_ID_NEXT:
98 		report = report_enum->report_id_hash[rid];
99 		if (!report)
100 			return NULL;
101 
102 		list = report->list.next;
103 		if (list == &report_enum->report_list)
104 			return NULL;
105 
106 		report = list_entry(list, struct hid_report, list);
107 		rinfo->report_id = report->id;
108 		break;
109 
110 	default:
111 		return NULL;
112 	}
113 
114 	return report_enum->report_id_hash[rinfo->report_id];
115 }
116 
117 /*
118  * Perform an exhaustive search of the report table for a usage, given its
119  * type and usage id.
120  */
121 static struct hid_field *
hiddev_lookup_usage(struct hid_device * hid,struct hiddev_usage_ref * uref)122 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
123 {
124 	int i, j;
125 	struct hid_report *report;
126 	struct hid_report_enum *report_enum;
127 	struct hid_field *field;
128 
129 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
130 	    uref->report_type > HID_REPORT_TYPE_MAX)
131 		return NULL;
132 
133 	report_enum = hid->report_enum +
134 		(uref->report_type - HID_REPORT_TYPE_MIN);
135 
136 	list_for_each_entry(report, &report_enum->report_list, list) {
137 		for (i = 0; i < report->maxfield; i++) {
138 			field = report->field[i];
139 			for (j = 0; j < field->maxusage; j++) {
140 				if (field->usage[j].hid == uref->usage_code) {
141 					uref->report_id = report->id;
142 					uref->field_index = i;
143 					uref->usage_index = j;
144 					return field;
145 				}
146 			}
147 		}
148 	}
149 
150 	return NULL;
151 }
152 
hiddev_send_event(struct hid_device * hid,struct hiddev_usage_ref * uref)153 static void hiddev_send_event(struct hid_device *hid,
154 			      struct hiddev_usage_ref *uref)
155 {
156 	struct hiddev *hiddev = hid->hiddev;
157 	struct hiddev_list *list;
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&hiddev->list_lock, flags);
161 	list_for_each_entry(list, &hiddev->list, node) {
162 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
163 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
164 			list->buffer[list->head] = *uref;
165 			list->head = (list->head + 1) &
166 				(HIDDEV_BUFFER_SIZE - 1);
167 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
168 		}
169 	}
170 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
171 
172 	wake_up_interruptible(&hiddev->wait);
173 }
174 
175 /*
176  * This is where hid.c calls into hiddev to pass an event that occurred over
177  * the interrupt pipe
178  */
hiddev_hid_event(struct hid_device * hid,struct hid_field * field,struct hid_usage * usage,__s32 value)179 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
180 		      struct hid_usage *usage, __s32 value)
181 {
182 	unsigned type = field->report_type;
183 	struct hiddev_usage_ref uref;
184 
185 	uref.report_type =
186 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
187 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
188 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
189 	uref.report_id = field->report->id;
190 	uref.field_index = field->index;
191 	uref.usage_index = (usage - field->usage);
192 	uref.usage_code = usage->hid;
193 	uref.value = value;
194 
195 	hiddev_send_event(hid, &uref);
196 }
197 EXPORT_SYMBOL_GPL(hiddev_hid_event);
198 
hiddev_report_event(struct hid_device * hid,struct hid_report * report)199 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
200 {
201 	unsigned type = report->type;
202 	struct hiddev_usage_ref uref;
203 
204 	memset(&uref, 0, sizeof(uref));
205 	uref.report_type =
206 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
207 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
208 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
209 	uref.report_id = report->id;
210 	uref.field_index = HID_FIELD_INDEX_NONE;
211 
212 	hiddev_send_event(hid, &uref);
213 }
214 
215 /*
216  * fasync file op
217  */
hiddev_fasync(int fd,struct file * file,int on)218 static int hiddev_fasync(int fd, struct file *file, int on)
219 {
220 	struct hiddev_list *list = file->private_data;
221 
222 	return fasync_helper(fd, file, on, &list->fasync);
223 }
224 
225 
226 /*
227  * release file op
228  */
hiddev_release(struct inode * inode,struct file * file)229 static int hiddev_release(struct inode * inode, struct file * file)
230 {
231 	struct hiddev_list *list = file->private_data;
232 	unsigned long flags;
233 
234 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
235 	list_del(&list->node);
236 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
237 
238 	mutex_lock(&list->hiddev->existancelock);
239 	if (!--list->hiddev->open) {
240 		if (list->hiddev->exist) {
241 			hid_hw_close(list->hiddev->hid);
242 			hid_hw_power(list->hiddev->hid, PM_HINT_NORMAL);
243 		} else {
244 			mutex_unlock(&list->hiddev->existancelock);
245 			kfree(list->hiddev);
246 			vfree(list);
247 			return 0;
248 		}
249 	}
250 
251 	mutex_unlock(&list->hiddev->existancelock);
252 	vfree(list);
253 
254 	return 0;
255 }
256 
__hiddev_open(struct hiddev * hiddev,struct file * file)257 static int __hiddev_open(struct hiddev *hiddev, struct file *file)
258 {
259 	struct hiddev_list *list;
260 	int error;
261 
262 	lockdep_assert_held(&hiddev->existancelock);
263 
264 	list = vzalloc(sizeof(*list));
265 	if (!list)
266 		return -ENOMEM;
267 
268 	mutex_init(&list->thread_lock);
269 	list->hiddev = hiddev;
270 
271 	if (!hiddev->open++) {
272 		error = hid_hw_power(hiddev->hid, PM_HINT_FULLON);
273 		if (error < 0)
274 			goto err_drop_count;
275 
276 		error = hid_hw_open(hiddev->hid);
277 		if (error < 0)
278 			goto err_normal_power;
279 	}
280 
281 	spin_lock_irq(&hiddev->list_lock);
282 	list_add_tail(&list->node, &hiddev->list);
283 	spin_unlock_irq(&hiddev->list_lock);
284 
285 	file->private_data = list;
286 
287 	return 0;
288 
289 err_normal_power:
290 	hid_hw_power(hiddev->hid, PM_HINT_NORMAL);
291 err_drop_count:
292 	hiddev->open--;
293 	vfree(list);
294 	return error;
295 }
296 
297 /*
298  * open file op
299  */
hiddev_open(struct inode * inode,struct file * file)300 static int hiddev_open(struct inode *inode, struct file *file)
301 {
302 	struct usb_interface *intf;
303 	struct hid_device *hid;
304 	struct hiddev *hiddev;
305 	int res;
306 
307 	intf = usbhid_find_interface(iminor(inode));
308 	if (!intf)
309 		return -ENODEV;
310 
311 	hid = usb_get_intfdata(intf);
312 	hiddev = hid->hiddev;
313 
314 	mutex_lock(&hiddev->existancelock);
315 	res = hiddev->exist ? __hiddev_open(hiddev, file) : -ENODEV;
316 	mutex_unlock(&hiddev->existancelock);
317 
318 	return res;
319 }
320 
321 /*
322  * "write" file op
323  */
hiddev_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)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  */
hiddev_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)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  */
hiddev_poll(struct file * file,poll_table * wait)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;
432 	if (!list->hiddev->exist)
433 		return EPOLLERR | EPOLLHUP;
434 	return 0;
435 }
436 
437 /*
438  * "ioctl" file op
439  */
hiddev_ioctl_usage(struct hiddev * hiddev,unsigned int cmd,void __user * user_arg)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 			if (uref->usage_index >= field->report_count)
536 				goto inval;
537 			uref->value = field->value[uref->usage_index];
538 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
539 				goto fault;
540 			goto goodreturn;
541 
542 		case HIDIOCSUSAGE:
543 			if (uref->usage_index >= field->report_count)
544 				goto inval;
545 			field->value[uref->usage_index] = uref->value;
546 			goto goodreturn;
547 
548 		case HIDIOCGCOLLECTIONINDEX:
549 			i = field->usage[uref->usage_index].collection_index;
550 			kfree(uref_multi);
551 			return i;
552 		case HIDIOCGUSAGES:
553 			for (i = 0; i < uref_multi->num_values; i++)
554 				uref_multi->values[i] =
555 				    field->value[uref->usage_index + i];
556 			if (copy_to_user(user_arg, uref_multi,
557 					 sizeof(*uref_multi)))
558 				goto fault;
559 			goto goodreturn;
560 		case HIDIOCSUSAGES:
561 			for (i = 0; i < uref_multi->num_values; i++)
562 				field->value[uref->usage_index + i] =
563 				    uref_multi->values[i];
564 			goto goodreturn;
565 		}
566 
567 goodreturn:
568 		kfree(uref_multi);
569 		return 0;
570 fault:
571 		kfree(uref_multi);
572 		return -EFAULT;
573 inval:
574 		kfree(uref_multi);
575 		return -EINVAL;
576 	}
577 }
578 
hiddev_ioctl_string(struct hiddev * hiddev,unsigned int cmd,void __user * user_arg)579 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
580 {
581 	struct hid_device *hid = hiddev->hid;
582 	struct usb_device *dev = hid_to_usb_dev(hid);
583 	int idx, len;
584 	char *buf;
585 
586 	if (get_user(idx, (int __user *)user_arg))
587 		return -EFAULT;
588 
589 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
590 		return -ENOMEM;
591 
592 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
593 		kfree(buf);
594 		return -EINVAL;
595 	}
596 
597 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
598 		kfree(buf);
599 		return -EFAULT;
600 	}
601 
602 	kfree(buf);
603 
604 	return len;
605 }
606 
hiddev_ioctl(struct file * file,unsigned int cmd,unsigned long arg)607 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
608 {
609 	struct hiddev_list *list = file->private_data;
610 	struct hiddev *hiddev = list->hiddev;
611 	struct hid_device *hid;
612 	struct hiddev_collection_info cinfo;
613 	struct hiddev_report_info rinfo;
614 	struct hiddev_field_info finfo;
615 	struct hiddev_devinfo dinfo;
616 	struct hid_report *report;
617 	struct hid_field *field;
618 	void __user *user_arg = (void __user *)arg;
619 	int i, r = -EINVAL;
620 
621 	/* Called without BKL by compat methods so no BKL taken */
622 
623 	mutex_lock(&hiddev->existancelock);
624 	if (!hiddev->exist) {
625 		r = -ENODEV;
626 		goto ret_unlock;
627 	}
628 
629 	hid = hiddev->hid;
630 
631 	switch (cmd) {
632 
633 	case HIDIOCGVERSION:
634 		r = put_user(HID_VERSION, (int __user *)arg) ?
635 			-EFAULT : 0;
636 		break;
637 
638 	case HIDIOCAPPLICATION:
639 		if (arg >= hid->maxapplication)
640 			break;
641 
642 		for (i = 0; i < hid->maxcollection; i++)
643 			if (hid->collection[i].type ==
644 			    HID_COLLECTION_APPLICATION && arg-- == 0)
645 				break;
646 
647 		if (i < hid->maxcollection)
648 			r = hid->collection[i].usage;
649 		break;
650 
651 	case HIDIOCGDEVINFO:
652 		{
653 			struct usb_device *dev = hid_to_usb_dev(hid);
654 			struct usbhid_device *usbhid = hid->driver_data;
655 
656 			memset(&dinfo, 0, sizeof(dinfo));
657 
658 			dinfo.bustype = BUS_USB;
659 			dinfo.busnum = dev->bus->busnum;
660 			dinfo.devnum = dev->devnum;
661 			dinfo.ifnum = usbhid->ifnum;
662 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
663 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
664 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
665 			dinfo.num_applications = hid->maxapplication;
666 
667 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
668 				-EFAULT : 0;
669 			break;
670 		}
671 
672 	case HIDIOCGFLAG:
673 		r = put_user(list->flags, (int __user *)arg) ?
674 			-EFAULT : 0;
675 		break;
676 
677 	case HIDIOCSFLAG:
678 		{
679 			int newflags;
680 
681 			if (get_user(newflags, (int __user *)arg)) {
682 				r = -EFAULT;
683 				break;
684 			}
685 
686 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
687 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
688 			     (newflags & HIDDEV_FLAG_UREF) == 0))
689 				break;
690 
691 			list->flags = newflags;
692 
693 			r = 0;
694 			break;
695 		}
696 
697 	case HIDIOCGSTRING:
698 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
699 		break;
700 
701 	case HIDIOCINITREPORT:
702 		usbhid_init_reports(hid);
703 		hiddev->initialized = true;
704 		r = 0;
705 		break;
706 
707 	case HIDIOCGREPORT:
708 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
709 			r = -EFAULT;
710 			break;
711 		}
712 
713 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
714 			break;
715 
716 		report = hiddev_lookup_report(hid, &rinfo);
717 		if (report == NULL)
718 			break;
719 
720 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
721 		hid_hw_wait(hid);
722 
723 		r = 0;
724 		break;
725 
726 	case HIDIOCSREPORT:
727 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
728 			r = -EFAULT;
729 			break;
730 		}
731 
732 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
733 			break;
734 
735 		report = hiddev_lookup_report(hid, &rinfo);
736 		if (report == NULL)
737 			break;
738 
739 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
740 		hid_hw_wait(hid);
741 
742 		r = 0;
743 		break;
744 
745 	case HIDIOCGREPORTINFO:
746 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
747 			r = -EFAULT;
748 			break;
749 		}
750 
751 		report = hiddev_lookup_report(hid, &rinfo);
752 		if (report == NULL)
753 			break;
754 
755 		rinfo.num_fields = report->maxfield;
756 
757 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
758 			-EFAULT : 0;
759 		break;
760 
761 	case HIDIOCGFIELDINFO:
762 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
763 			r = -EFAULT;
764 			break;
765 		}
766 
767 		rinfo.report_type = finfo.report_type;
768 		rinfo.report_id = finfo.report_id;
769 
770 		report = hiddev_lookup_report(hid, &rinfo);
771 		if (report == NULL)
772 			break;
773 
774 		if (finfo.field_index >= report->maxfield)
775 			break;
776 		finfo.field_index = array_index_nospec(finfo.field_index,
777 						       report->maxfield);
778 
779 		field = report->field[finfo.field_index];
780 		memset(&finfo, 0, sizeof(finfo));
781 		finfo.report_type = rinfo.report_type;
782 		finfo.report_id = rinfo.report_id;
783 		finfo.field_index = field->report_count - 1;
784 		finfo.maxusage = field->maxusage;
785 		finfo.flags = field->flags;
786 		finfo.physical = field->physical;
787 		finfo.logical = field->logical;
788 		finfo.application = field->application;
789 		finfo.logical_minimum = field->logical_minimum;
790 		finfo.logical_maximum = field->logical_maximum;
791 		finfo.physical_minimum = field->physical_minimum;
792 		finfo.physical_maximum = field->physical_maximum;
793 		finfo.unit_exponent = field->unit_exponent;
794 		finfo.unit = field->unit;
795 
796 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
797 			-EFAULT : 0;
798 		break;
799 
800 	case HIDIOCGUCODE:
801 		/* fall through */
802 	case HIDIOCGUSAGE:
803 	case HIDIOCSUSAGE:
804 	case HIDIOCGUSAGES:
805 	case HIDIOCSUSAGES:
806 	case HIDIOCGCOLLECTIONINDEX:
807 		if (!hiddev->initialized) {
808 			usbhid_init_reports(hid);
809 			hiddev->initialized = true;
810 		}
811 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
812 		break;
813 
814 	case HIDIOCGCOLLECTIONINFO:
815 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
816 			r = -EFAULT;
817 			break;
818 		}
819 
820 		if (cinfo.index >= hid->maxcollection)
821 			break;
822 		cinfo.index = array_index_nospec(cinfo.index,
823 						 hid->maxcollection);
824 
825 		cinfo.type = hid->collection[cinfo.index].type;
826 		cinfo.usage = hid->collection[cinfo.index].usage;
827 		cinfo.level = hid->collection[cinfo.index].level;
828 
829 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
830 			-EFAULT : 0;
831 		break;
832 
833 	default:
834 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
835 			break;
836 
837 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
838 			int len = strlen(hid->name) + 1;
839 			if (len > _IOC_SIZE(cmd))
840 				 len = _IOC_SIZE(cmd);
841 			r = copy_to_user(user_arg, hid->name, len) ?
842 				-EFAULT : len;
843 			break;
844 		}
845 
846 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
847 			int len = strlen(hid->phys) + 1;
848 			if (len > _IOC_SIZE(cmd))
849 				len = _IOC_SIZE(cmd);
850 			r = copy_to_user(user_arg, hid->phys, len) ?
851 				-EFAULT : len;
852 			break;
853 		}
854 	}
855 
856 ret_unlock:
857 	mutex_unlock(&hiddev->existancelock);
858 	return r;
859 }
860 
861 #ifdef CONFIG_COMPAT
hiddev_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)862 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
863 {
864 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
865 }
866 #endif
867 
868 static const struct file_operations hiddev_fops = {
869 	.owner =	THIS_MODULE,
870 	.read =		hiddev_read,
871 	.write =	hiddev_write,
872 	.poll =		hiddev_poll,
873 	.open =		hiddev_open,
874 	.release =	hiddev_release,
875 	.unlocked_ioctl =	hiddev_ioctl,
876 	.fasync =	hiddev_fasync,
877 #ifdef CONFIG_COMPAT
878 	.compat_ioctl	= hiddev_compat_ioctl,
879 #endif
880 	.llseek		= noop_llseek,
881 };
882 
hiddev_devnode(struct device * dev,umode_t * mode)883 static char *hiddev_devnode(struct device *dev, umode_t *mode)
884 {
885 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
886 }
887 
888 static struct usb_class_driver hiddev_class = {
889 	.name =		"hiddev%d",
890 	.devnode =	hiddev_devnode,
891 	.fops =		&hiddev_fops,
892 	.minor_base =	HIDDEV_MINOR_BASE,
893 };
894 
895 /*
896  * This is where hid.c calls us to connect a hid device to the hiddev driver
897  */
hiddev_connect(struct hid_device * hid,unsigned int force)898 int hiddev_connect(struct hid_device *hid, unsigned int force)
899 {
900 	struct hiddev *hiddev;
901 	struct usbhid_device *usbhid = hid->driver_data;
902 	int retval;
903 
904 	if (!force) {
905 		unsigned int i;
906 		for (i = 0; i < hid->maxcollection; i++)
907 			if (hid->collection[i].type ==
908 			    HID_COLLECTION_APPLICATION &&
909 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
910 				break;
911 
912 		if (i == hid->maxcollection)
913 			return -1;
914 	}
915 
916 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
917 		return -1;
918 
919 	init_waitqueue_head(&hiddev->wait);
920 	INIT_LIST_HEAD(&hiddev->list);
921 	spin_lock_init(&hiddev->list_lock);
922 	mutex_init(&hiddev->existancelock);
923 	hid->hiddev = hiddev;
924 	hiddev->hid = hid;
925 	hiddev->exist = 1;
926 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
927 	if (retval) {
928 		hid_err(hid, "Not able to get a minor for this device\n");
929 		hid->hiddev = NULL;
930 		kfree(hiddev);
931 		return -1;
932 	}
933 
934 	/*
935 	 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
936 	 * the reports.
937 	 */
938 	hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
939 
940 	hiddev->minor = usbhid->intf->minor;
941 
942 	return 0;
943 }
944 
945 /*
946  * This is where hid.c calls us to disconnect a hiddev device from the
947  * corresponding hid device (usually because the usb device has disconnected)
948  */
949 static struct usb_class_driver hiddev_class;
hiddev_disconnect(struct hid_device * hid)950 void hiddev_disconnect(struct hid_device *hid)
951 {
952 	struct hiddev *hiddev = hid->hiddev;
953 	struct usbhid_device *usbhid = hid->driver_data;
954 
955 	usb_deregister_dev(usbhid->intf, &hiddev_class);
956 
957 	mutex_lock(&hiddev->existancelock);
958 	hiddev->exist = 0;
959 
960 	if (hiddev->open) {
961 		hid_hw_close(hiddev->hid);
962 		wake_up_interruptible(&hiddev->wait);
963 		mutex_unlock(&hiddev->existancelock);
964 	} else {
965 		mutex_unlock(&hiddev->existancelock);
966 		kfree(hiddev);
967 	}
968 }
969