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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/module.h>
31 #include <linux/init.h>
32 #include <linux/input.h>
33 #include <linux/usb.h>
34 #include <linux/hid.h>
35 #include <linux/hiddev.h>
36 #include <linux/compat.h>
37 #include <linux/vmalloc.h>
38 #include <linux/nospec.h>
39 #include "usbhid.h"
40 
41 #ifdef CONFIG_USB_DYNAMIC_MINORS
42 #define HIDDEV_MINOR_BASE	0
43 #define HIDDEV_MINORS		256
44 #else
45 #define HIDDEV_MINOR_BASE	96
46 #define HIDDEV_MINORS		16
47 #endif
48 #define HIDDEV_BUFFER_SIZE	2048
49 
50 struct hiddev {
51 	int exist;
52 	int open;
53 	struct mutex existancelock;
54 	wait_queue_head_t wait;
55 	struct hid_device *hid;
56 	struct list_head list;
57 	spinlock_t list_lock;
58 };
59 
60 struct hiddev_list {
61 	struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
62 	int head;
63 	int tail;
64 	unsigned flags;
65 	struct fasync_struct *fasync;
66 	struct hiddev *hiddev;
67 	struct list_head node;
68 	struct mutex thread_lock;
69 };
70 
71 /*
72  * Find a report, given the report's type and ID.  The ID can be specified
73  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
74  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
75  * given type which follows old_id.
76  */
77 static struct hid_report *
hiddev_lookup_report(struct hid_device * hid,struct hiddev_report_info * rinfo)78 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
79 {
80 	unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
81 	unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
82 	struct hid_report_enum *report_enum;
83 	struct hid_report *report;
84 	struct list_head *list;
85 
86 	if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
87 	    rinfo->report_type > HID_REPORT_TYPE_MAX)
88 		return NULL;
89 
90 	report_enum = hid->report_enum +
91 		(rinfo->report_type - HID_REPORT_TYPE_MIN);
92 
93 	switch (flags) {
94 	case 0: /* Nothing to do -- report_id is already set correctly */
95 		break;
96 
97 	case HID_REPORT_ID_FIRST:
98 		if (list_empty(&report_enum->report_list))
99 			return NULL;
100 
101 		list = report_enum->report_list.next;
102 		report = list_entry(list, struct hid_report, list);
103 		rinfo->report_id = report->id;
104 		break;
105 
106 	case HID_REPORT_ID_NEXT:
107 		report = report_enum->report_id_hash[rid];
108 		if (!report)
109 			return NULL;
110 
111 		list = report->list.next;
112 		if (list == &report_enum->report_list)
113 			return NULL;
114 
115 		report = list_entry(list, struct hid_report, list);
116 		rinfo->report_id = report->id;
117 		break;
118 
119 	default:
120 		return NULL;
121 	}
122 
123 	return report_enum->report_id_hash[rinfo->report_id];
124 }
125 
126 /*
127  * Perform an exhaustive search of the report table for a usage, given its
128  * type and usage id.
129  */
130 static struct hid_field *
hiddev_lookup_usage(struct hid_device * hid,struct hiddev_usage_ref * uref)131 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
132 {
133 	int i, j;
134 	struct hid_report *report;
135 	struct hid_report_enum *report_enum;
136 	struct hid_field *field;
137 
138 	if (uref->report_type < HID_REPORT_TYPE_MIN ||
139 	    uref->report_type > HID_REPORT_TYPE_MAX)
140 		return NULL;
141 
142 	report_enum = hid->report_enum +
143 		(uref->report_type - HID_REPORT_TYPE_MIN);
144 
145 	list_for_each_entry(report, &report_enum->report_list, list) {
146 		for (i = 0; i < report->maxfield; i++) {
147 			field = report->field[i];
148 			for (j = 0; j < field->maxusage; j++) {
149 				if (field->usage[j].hid == uref->usage_code) {
150 					uref->report_id = report->id;
151 					uref->field_index = i;
152 					uref->usage_index = j;
153 					return field;
154 				}
155 			}
156 		}
157 	}
158 
159 	return NULL;
160 }
161 
hiddev_send_event(struct hid_device * hid,struct hiddev_usage_ref * uref)162 static void hiddev_send_event(struct hid_device *hid,
163 			      struct hiddev_usage_ref *uref)
164 {
165 	struct hiddev *hiddev = hid->hiddev;
166 	struct hiddev_list *list;
167 	unsigned long flags;
168 
169 	spin_lock_irqsave(&hiddev->list_lock, flags);
170 	list_for_each_entry(list, &hiddev->list, node) {
171 		if (uref->field_index != HID_FIELD_INDEX_NONE ||
172 		    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
173 			list->buffer[list->head] = *uref;
174 			list->head = (list->head + 1) &
175 				(HIDDEV_BUFFER_SIZE - 1);
176 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
177 		}
178 	}
179 	spin_unlock_irqrestore(&hiddev->list_lock, flags);
180 
181 	wake_up_interruptible(&hiddev->wait);
182 }
183 
184 /*
185  * This is where hid.c calls into hiddev to pass an event that occurred over
186  * the interrupt pipe
187  */
hiddev_hid_event(struct hid_device * hid,struct hid_field * field,struct hid_usage * usage,__s32 value)188 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
189 		      struct hid_usage *usage, __s32 value)
190 {
191 	unsigned type = field->report_type;
192 	struct hiddev_usage_ref uref;
193 
194 	uref.report_type =
195 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
196 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
197 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
198 	uref.report_id = field->report->id;
199 	uref.field_index = field->index;
200 	uref.usage_index = (usage - field->usage);
201 	uref.usage_code = usage->hid;
202 	uref.value = value;
203 
204 	hiddev_send_event(hid, &uref);
205 }
206 EXPORT_SYMBOL_GPL(hiddev_hid_event);
207 
hiddev_report_event(struct hid_device * hid,struct hid_report * report)208 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
209 {
210 	unsigned type = report->type;
211 	struct hiddev_usage_ref uref;
212 
213 	memset(&uref, 0, sizeof(uref));
214 	uref.report_type =
215 	  (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
216 	  ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
217 	   ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
218 	uref.report_id = report->id;
219 	uref.field_index = HID_FIELD_INDEX_NONE;
220 
221 	hiddev_send_event(hid, &uref);
222 }
223 
224 /*
225  * fasync file op
226  */
hiddev_fasync(int fd,struct file * file,int on)227 static int hiddev_fasync(int fd, struct file *file, int on)
228 {
229 	struct hiddev_list *list = file->private_data;
230 
231 	return fasync_helper(fd, file, on, &list->fasync);
232 }
233 
234 
235 /*
236  * release file op
237  */
hiddev_release(struct inode * inode,struct file * file)238 static int hiddev_release(struct inode * inode, struct file * file)
239 {
240 	struct hiddev_list *list = file->private_data;
241 	unsigned long flags;
242 
243 	spin_lock_irqsave(&list->hiddev->list_lock, flags);
244 	list_del(&list->node);
245 	spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
246 
247 	mutex_lock(&list->hiddev->existancelock);
248 	if (!--list->hiddev->open) {
249 		if (list->hiddev->exist) {
250 			usbhid_close(list->hiddev->hid);
251 			usbhid_put_power(list->hiddev->hid);
252 		} else {
253 			mutex_unlock(&list->hiddev->existancelock);
254 			kfree(list->hiddev);
255 			vfree(list);
256 			return 0;
257 		}
258 	}
259 
260 	mutex_unlock(&list->hiddev->existancelock);
261 	vfree(list);
262 
263 	return 0;
264 }
265 
266 /*
267  * open file op
268  */
hiddev_open(struct inode * inode,struct file * file)269 static int hiddev_open(struct inode *inode, struct file *file)
270 {
271 	struct hiddev_list *list;
272 	struct usb_interface *intf;
273 	struct hid_device *hid;
274 	struct hiddev *hiddev;
275 	int res;
276 
277 	intf = usbhid_find_interface(iminor(inode));
278 	if (!intf)
279 		return -ENODEV;
280 	hid = usb_get_intfdata(intf);
281 	hiddev = hid->hiddev;
282 
283 	if (!(list = vzalloc(sizeof(struct hiddev_list))))
284 		return -ENOMEM;
285 	mutex_init(&list->thread_lock);
286 	list->hiddev = hiddev;
287 	file->private_data = list;
288 
289 	/*
290 	 * no need for locking because the USB major number
291 	 * is shared which usbcore guards against disconnect
292 	 */
293 	if (list->hiddev->exist) {
294 		if (!list->hiddev->open++) {
295 			res = usbhid_open(hiddev->hid);
296 			if (res < 0) {
297 				res = -EIO;
298 				goto bail;
299 			}
300 		}
301 	} else {
302 		res = -ENODEV;
303 		goto bail;
304 	}
305 
306 	spin_lock_irq(&list->hiddev->list_lock);
307 	list_add_tail(&list->node, &hiddev->list);
308 	spin_unlock_irq(&list->hiddev->list_lock);
309 
310 	mutex_lock(&hiddev->existancelock);
311 	/*
312 	 * recheck exist with existance lock held to
313 	 * avoid opening a disconnected device
314 	 */
315 	if (!list->hiddev->exist) {
316 		res = -ENODEV;
317 		goto bail_unlock;
318 	}
319 	if (!list->hiddev->open++)
320 		if (list->hiddev->exist) {
321 			struct hid_device *hid = hiddev->hid;
322 			res = usbhid_get_power(hid);
323 			if (res < 0) {
324 				res = -EIO;
325 				goto bail_unlock;
326 			}
327 			usbhid_open(hid);
328 		}
329 	mutex_unlock(&hiddev->existancelock);
330 	return 0;
331 bail_unlock:
332 	mutex_unlock(&hiddev->existancelock);
333 
334 	spin_lock_irq(&list->hiddev->list_lock);
335 	list_del(&list->node);
336 	spin_unlock_irq(&list->hiddev->list_lock);
337 bail:
338 	file->private_data = NULL;
339 	vfree(list);
340 	return res;
341 }
342 
343 /*
344  * "write" file op
345  */
hiddev_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)346 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
347 {
348 	return -EINVAL;
349 }
350 
351 /*
352  * "read" file op
353  */
hiddev_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)354 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
355 {
356 	DEFINE_WAIT(wait);
357 	struct hiddev_list *list = file->private_data;
358 	int event_size;
359 	int retval;
360 
361 	event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
362 		sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
363 
364 	if (count < event_size)
365 		return 0;
366 
367 	/* lock against other threads */
368 	retval = mutex_lock_interruptible(&list->thread_lock);
369 	if (retval)
370 		return -ERESTARTSYS;
371 
372 	while (retval == 0) {
373 		if (list->head == list->tail) {
374 			prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
375 
376 			while (list->head == list->tail) {
377 				if (signal_pending(current)) {
378 					retval = -ERESTARTSYS;
379 					break;
380 				}
381 				if (!list->hiddev->exist) {
382 					retval = -EIO;
383 					break;
384 				}
385 				if (file->f_flags & O_NONBLOCK) {
386 					retval = -EAGAIN;
387 					break;
388 				}
389 
390 				/* let O_NONBLOCK tasks run */
391 				mutex_unlock(&list->thread_lock);
392 				schedule();
393 				if (mutex_lock_interruptible(&list->thread_lock)) {
394 					finish_wait(&list->hiddev->wait, &wait);
395 					return -EINTR;
396 				}
397 				set_current_state(TASK_INTERRUPTIBLE);
398 			}
399 			finish_wait(&list->hiddev->wait, &wait);
400 
401 		}
402 
403 		if (retval) {
404 			mutex_unlock(&list->thread_lock);
405 			return retval;
406 		}
407 
408 
409 		while (list->head != list->tail &&
410 		       retval + event_size <= count) {
411 			if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
412 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
413 					struct hiddev_event event;
414 
415 					event.hid = list->buffer[list->tail].usage_code;
416 					event.value = list->buffer[list->tail].value;
417 					if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
418 						mutex_unlock(&list->thread_lock);
419 						return -EFAULT;
420 					}
421 					retval += sizeof(struct hiddev_event);
422 				}
423 			} else {
424 				if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
425 				    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
426 
427 					if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
428 						mutex_unlock(&list->thread_lock);
429 						return -EFAULT;
430 					}
431 					retval += sizeof(struct hiddev_usage_ref);
432 				}
433 			}
434 			list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
435 		}
436 
437 	}
438 	mutex_unlock(&list->thread_lock);
439 
440 	return retval;
441 }
442 
443 /*
444  * "poll" file op
445  * No kernel lock - fine
446  */
hiddev_poll(struct file * file,poll_table * wait)447 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
448 {
449 	struct hiddev_list *list = file->private_data;
450 
451 	poll_wait(file, &list->hiddev->wait, wait);
452 	if (list->head != list->tail)
453 		return POLLIN | POLLRDNORM;
454 	if (!list->hiddev->exist)
455 		return POLLERR | POLLHUP;
456 	return 0;
457 }
458 
459 /*
460  * "ioctl" file op
461  */
hiddev_ioctl_usage(struct hiddev * hiddev,unsigned int cmd,void __user * user_arg)462 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
463 {
464 	struct hid_device *hid = hiddev->hid;
465 	struct hiddev_report_info rinfo;
466 	struct hiddev_usage_ref_multi *uref_multi = NULL;
467 	struct hiddev_usage_ref *uref;
468 	struct hid_report *report;
469 	struct hid_field *field;
470 	int i;
471 
472 	uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
473 	if (!uref_multi)
474 		return -ENOMEM;
475 	uref = &uref_multi->uref;
476 	if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
477 		if (copy_from_user(uref_multi, user_arg,
478 				   sizeof(*uref_multi)))
479 			goto fault;
480 	} else {
481 		if (copy_from_user(uref, user_arg, sizeof(*uref)))
482 			goto fault;
483 	}
484 
485 	switch (cmd) {
486 	case HIDIOCGUCODE:
487 		rinfo.report_type = uref->report_type;
488 		rinfo.report_id = uref->report_id;
489 		if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
490 			goto inval;
491 
492 		if (uref->field_index >= report->maxfield)
493 			goto inval;
494 		uref->field_index = array_index_nospec(uref->field_index,
495 						       report->maxfield);
496 
497 		field = report->field[uref->field_index];
498 		if (uref->usage_index >= field->maxusage)
499 			goto inval;
500 		uref->usage_index = array_index_nospec(uref->usage_index,
501 						       field->maxusage);
502 
503 		uref->usage_code = field->usage[uref->usage_index].hid;
504 
505 		if (copy_to_user(user_arg, uref, sizeof(*uref)))
506 			goto fault;
507 
508 		goto goodreturn;
509 
510 	default:
511 		if (cmd != HIDIOCGUSAGE &&
512 		    cmd != HIDIOCGUSAGES &&
513 		    uref->report_type == HID_REPORT_TYPE_INPUT)
514 			goto inval;
515 
516 		if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
517 			field = hiddev_lookup_usage(hid, uref);
518 			if (field == NULL)
519 				goto inval;
520 		} else {
521 			rinfo.report_type = uref->report_type;
522 			rinfo.report_id = uref->report_id;
523 			if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
524 				goto inval;
525 
526 			if (uref->field_index >= report->maxfield)
527 				goto inval;
528 			uref->field_index = array_index_nospec(uref->field_index,
529 							       report->maxfield);
530 
531 			field = report->field[uref->field_index];
532 
533 			if (cmd == HIDIOCGCOLLECTIONINDEX) {
534 				if (uref->usage_index >= field->maxusage)
535 					goto inval;
536 				uref->usage_index =
537 					array_index_nospec(uref->usage_index,
538 							   field->maxusage);
539 			} else if (uref->usage_index >= field->report_count)
540 				goto inval;
541 		}
542 
543 		if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
544 			if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
545 			    uref->usage_index + uref_multi->num_values >
546 			    field->report_count)
547 				goto inval;
548 
549 			uref->usage_index =
550 				array_index_nospec(uref->usage_index,
551 						   field->report_count -
552 						   uref_multi->num_values);
553 		}
554 
555 		switch (cmd) {
556 		case HIDIOCGUSAGE:
557 			if (uref->usage_index >= field->report_count)
558 				goto inval;
559 			uref->value = field->value[uref->usage_index];
560 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
561 				goto fault;
562 			goto goodreturn;
563 
564 		case HIDIOCSUSAGE:
565 			if (uref->usage_index >= field->report_count)
566 				goto inval;
567 			field->value[uref->usage_index] = uref->value;
568 			goto goodreturn;
569 
570 		case HIDIOCGCOLLECTIONINDEX:
571 			i = field->usage[uref->usage_index].collection_index;
572 			kfree(uref_multi);
573 			return i;
574 		case HIDIOCGUSAGES:
575 			for (i = 0; i < uref_multi->num_values; i++)
576 				uref_multi->values[i] =
577 				    field->value[uref->usage_index + i];
578 			if (copy_to_user(user_arg, uref_multi,
579 					 sizeof(*uref_multi)))
580 				goto fault;
581 			goto goodreturn;
582 		case HIDIOCSUSAGES:
583 			for (i = 0; i < uref_multi->num_values; i++)
584 				field->value[uref->usage_index + i] =
585 				    uref_multi->values[i];
586 			goto goodreturn;
587 		}
588 
589 goodreturn:
590 		kfree(uref_multi);
591 		return 0;
592 fault:
593 		kfree(uref_multi);
594 		return -EFAULT;
595 inval:
596 		kfree(uref_multi);
597 		return -EINVAL;
598 	}
599 }
600 
hiddev_ioctl_string(struct hiddev * hiddev,unsigned int cmd,void __user * user_arg)601 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
602 {
603 	struct hid_device *hid = hiddev->hid;
604 	struct usb_device *dev = hid_to_usb_dev(hid);
605 	int idx, len;
606 	char *buf;
607 
608 	if (get_user(idx, (int __user *)user_arg))
609 		return -EFAULT;
610 
611 	if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
612 		return -ENOMEM;
613 
614 	if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
615 		kfree(buf);
616 		return -EINVAL;
617 	}
618 
619 	if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
620 		kfree(buf);
621 		return -EFAULT;
622 	}
623 
624 	kfree(buf);
625 
626 	return len;
627 }
628 
hiddev_ioctl(struct file * file,unsigned int cmd,unsigned long arg)629 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
630 {
631 	struct hiddev_list *list = file->private_data;
632 	struct hiddev *hiddev = list->hiddev;
633 	struct hid_device *hid;
634 	struct hiddev_collection_info cinfo;
635 	struct hiddev_report_info rinfo;
636 	struct hiddev_field_info finfo;
637 	struct hiddev_devinfo dinfo;
638 	struct hid_report *report;
639 	struct hid_field *field;
640 	void __user *user_arg = (void __user *)arg;
641 	int i, r = -EINVAL;
642 
643 	/* Called without BKL by compat methods so no BKL taken */
644 
645 	mutex_lock(&hiddev->existancelock);
646 	if (!hiddev->exist) {
647 		r = -ENODEV;
648 		goto ret_unlock;
649 	}
650 
651 	hid = hiddev->hid;
652 
653 	switch (cmd) {
654 
655 	case HIDIOCGVERSION:
656 		r = put_user(HID_VERSION, (int __user *)arg) ?
657 			-EFAULT : 0;
658 		break;
659 
660 	case HIDIOCAPPLICATION:
661 		if (arg >= hid->maxapplication)
662 			break;
663 
664 		for (i = 0; i < hid->maxcollection; i++)
665 			if (hid->collection[i].type ==
666 			    HID_COLLECTION_APPLICATION && arg-- == 0)
667 				break;
668 
669 		if (i < hid->maxcollection)
670 			r = hid->collection[i].usage;
671 		break;
672 
673 	case HIDIOCGDEVINFO:
674 		{
675 			struct usb_device *dev = hid_to_usb_dev(hid);
676 			struct usbhid_device *usbhid = hid->driver_data;
677 
678 			memset(&dinfo, 0, sizeof(dinfo));
679 
680 			dinfo.bustype = BUS_USB;
681 			dinfo.busnum = dev->bus->busnum;
682 			dinfo.devnum = dev->devnum;
683 			dinfo.ifnum = usbhid->ifnum;
684 			dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
685 			dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
686 			dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
687 			dinfo.num_applications = hid->maxapplication;
688 
689 			r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
690 				-EFAULT : 0;
691 			break;
692 		}
693 
694 	case HIDIOCGFLAG:
695 		r = put_user(list->flags, (int __user *)arg) ?
696 			-EFAULT : 0;
697 		break;
698 
699 	case HIDIOCSFLAG:
700 		{
701 			int newflags;
702 
703 			if (get_user(newflags, (int __user *)arg)) {
704 				r = -EFAULT;
705 				break;
706 			}
707 
708 			if ((newflags & ~HIDDEV_FLAGS) != 0 ||
709 			    ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
710 			     (newflags & HIDDEV_FLAG_UREF) == 0))
711 				break;
712 
713 			list->flags = newflags;
714 
715 			r = 0;
716 			break;
717 		}
718 
719 	case HIDIOCGSTRING:
720 		r = hiddev_ioctl_string(hiddev, cmd, user_arg);
721 		break;
722 
723 	case HIDIOCINITREPORT:
724 		usbhid_init_reports(hid);
725 		r = 0;
726 		break;
727 
728 	case HIDIOCGREPORT:
729 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
730 			r = -EFAULT;
731 			break;
732 		}
733 
734 		if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
735 			break;
736 
737 		report = hiddev_lookup_report(hid, &rinfo);
738 		if (report == NULL)
739 			break;
740 
741 		hid_hw_request(hid, report, HID_REQ_GET_REPORT);
742 		hid_hw_wait(hid);
743 
744 		r = 0;
745 		break;
746 
747 	case HIDIOCSREPORT:
748 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
749 			r = -EFAULT;
750 			break;
751 		}
752 
753 		if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
754 			break;
755 
756 		report = hiddev_lookup_report(hid, &rinfo);
757 		if (report == NULL)
758 			break;
759 
760 		hid_hw_request(hid, report, HID_REQ_SET_REPORT);
761 		hid_hw_wait(hid);
762 
763 		r = 0;
764 		break;
765 
766 	case HIDIOCGREPORTINFO:
767 		if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
768 			r = -EFAULT;
769 			break;
770 		}
771 
772 		report = hiddev_lookup_report(hid, &rinfo);
773 		if (report == NULL)
774 			break;
775 
776 		rinfo.num_fields = report->maxfield;
777 
778 		r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
779 			-EFAULT : 0;
780 		break;
781 
782 	case HIDIOCGFIELDINFO:
783 		if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
784 			r = -EFAULT;
785 			break;
786 		}
787 
788 		rinfo.report_type = finfo.report_type;
789 		rinfo.report_id = finfo.report_id;
790 
791 		report = hiddev_lookup_report(hid, &rinfo);
792 		if (report == NULL)
793 			break;
794 
795 		if (finfo.field_index >= report->maxfield)
796 			break;
797 		finfo.field_index = array_index_nospec(finfo.field_index,
798 						       report->maxfield);
799 
800 		field = report->field[finfo.field_index];
801 		memset(&finfo, 0, sizeof(finfo));
802 		finfo.report_type = rinfo.report_type;
803 		finfo.report_id = rinfo.report_id;
804 		finfo.field_index = field->report_count - 1;
805 		finfo.maxusage = field->maxusage;
806 		finfo.flags = field->flags;
807 		finfo.physical = field->physical;
808 		finfo.logical = field->logical;
809 		finfo.application = field->application;
810 		finfo.logical_minimum = field->logical_minimum;
811 		finfo.logical_maximum = field->logical_maximum;
812 		finfo.physical_minimum = field->physical_minimum;
813 		finfo.physical_maximum = field->physical_maximum;
814 		finfo.unit_exponent = field->unit_exponent;
815 		finfo.unit = field->unit;
816 
817 		r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
818 			-EFAULT : 0;
819 		break;
820 
821 	case HIDIOCGUCODE:
822 		/* fall through */
823 	case HIDIOCGUSAGE:
824 	case HIDIOCSUSAGE:
825 	case HIDIOCGUSAGES:
826 	case HIDIOCSUSAGES:
827 	case HIDIOCGCOLLECTIONINDEX:
828 		r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
829 		break;
830 
831 	case HIDIOCGCOLLECTIONINFO:
832 		if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
833 			r = -EFAULT;
834 			break;
835 		}
836 
837 		if (cinfo.index >= hid->maxcollection)
838 			break;
839 		cinfo.index = array_index_nospec(cinfo.index,
840 						 hid->maxcollection);
841 
842 		cinfo.type = hid->collection[cinfo.index].type;
843 		cinfo.usage = hid->collection[cinfo.index].usage;
844 		cinfo.level = hid->collection[cinfo.index].level;
845 
846 		r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
847 			-EFAULT : 0;
848 		break;
849 
850 	default:
851 		if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
852 			break;
853 
854 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
855 			int len = strlen(hid->name) + 1;
856 			if (len > _IOC_SIZE(cmd))
857 				 len = _IOC_SIZE(cmd);
858 			r = copy_to_user(user_arg, hid->name, len) ?
859 				-EFAULT : len;
860 			break;
861 		}
862 
863 		if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
864 			int len = strlen(hid->phys) + 1;
865 			if (len > _IOC_SIZE(cmd))
866 				len = _IOC_SIZE(cmd);
867 			r = copy_to_user(user_arg, hid->phys, len) ?
868 				-EFAULT : len;
869 			break;
870 		}
871 	}
872 
873 ret_unlock:
874 	mutex_unlock(&hiddev->existancelock);
875 	return r;
876 }
877 
878 #ifdef CONFIG_COMPAT
hiddev_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)879 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
880 {
881 	return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
882 }
883 #endif
884 
885 static const struct file_operations hiddev_fops = {
886 	.owner =	THIS_MODULE,
887 	.read =		hiddev_read,
888 	.write =	hiddev_write,
889 	.poll =		hiddev_poll,
890 	.open =		hiddev_open,
891 	.release =	hiddev_release,
892 	.unlocked_ioctl =	hiddev_ioctl,
893 	.fasync =	hiddev_fasync,
894 #ifdef CONFIG_COMPAT
895 	.compat_ioctl	= hiddev_compat_ioctl,
896 #endif
897 	.llseek		= noop_llseek,
898 };
899 
hiddev_devnode(struct device * dev,umode_t * mode)900 static char *hiddev_devnode(struct device *dev, umode_t *mode)
901 {
902 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
903 }
904 
905 static struct usb_class_driver hiddev_class = {
906 	.name =		"hiddev%d",
907 	.devnode =	hiddev_devnode,
908 	.fops =		&hiddev_fops,
909 	.minor_base =	HIDDEV_MINOR_BASE,
910 };
911 
912 /*
913  * This is where hid.c calls us to connect a hid device to the hiddev driver
914  */
hiddev_connect(struct hid_device * hid,unsigned int force)915 int hiddev_connect(struct hid_device *hid, unsigned int force)
916 {
917 	struct hiddev *hiddev;
918 	struct usbhid_device *usbhid = hid->driver_data;
919 	int retval;
920 
921 	if (!force) {
922 		unsigned int i;
923 		for (i = 0; i < hid->maxcollection; i++)
924 			if (hid->collection[i].type ==
925 			    HID_COLLECTION_APPLICATION &&
926 			    !IS_INPUT_APPLICATION(hid->collection[i].usage))
927 				break;
928 
929 		if (i == hid->maxcollection)
930 			return -1;
931 	}
932 
933 	if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
934 		return -1;
935 
936 	init_waitqueue_head(&hiddev->wait);
937 	INIT_LIST_HEAD(&hiddev->list);
938 	spin_lock_init(&hiddev->list_lock);
939 	mutex_init(&hiddev->existancelock);
940 	hid->hiddev = hiddev;
941 	hiddev->hid = hid;
942 	hiddev->exist = 1;
943 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
944 	if (retval) {
945 		hid_err(hid, "Not able to get a minor for this device\n");
946 		hid->hiddev = NULL;
947 		kfree(hiddev);
948 		return -1;
949 	}
950 	return 0;
951 }
952 
953 /*
954  * This is where hid.c calls us to disconnect a hiddev device from the
955  * corresponding hid device (usually because the usb device has disconnected)
956  */
957 static struct usb_class_driver hiddev_class;
hiddev_disconnect(struct hid_device * hid)958 void hiddev_disconnect(struct hid_device *hid)
959 {
960 	struct hiddev *hiddev = hid->hiddev;
961 	struct usbhid_device *usbhid = hid->driver_data;
962 
963 	usb_deregister_dev(usbhid->intf, &hiddev_class);
964 
965 	mutex_lock(&hiddev->existancelock);
966 	hiddev->exist = 0;
967 
968 	if (hiddev->open) {
969 		usbhid_close(hiddev->hid);
970 		wake_up_interruptible(&hiddev->wait);
971 		mutex_unlock(&hiddev->existancelock);
972 	} else {
973 		mutex_unlock(&hiddev->existancelock);
974 		kfree(hiddev);
975 	}
976 }
977