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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-stable.git] / drivers / hid / hidraw.c
blobc887f48756f4be2a4bac03128f2885bde96c1e39
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * HID raw devices, giving access to raw HID events.
4 *
5 * In comparison to hiddev, this device does not process the
6 * hid events at all (no parsing, no lookups). This lets applications
7 * to work on raw hid events as they want to, and avoids a need to
8 * use a transport-specific userspace libhid/libusb libraries.
9 *
10 * Copyright (c) 2007-2014 Jiri Kosina
11 */
12
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/fs.h>
17 #include <linux/module.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/cdev.h>
22 #include <linux/poll.h>
23 #include <linux/device.h>
24 #include <linux/major.h>
25 #include <linux/slab.h>
26 #include <linux/hid.h>
27 #include <linux/mutex.h>
28 #include <linux/sched/signal.h>
29 #include <linux/string.h>
30
31 #include <linux/hidraw.h>
32
33 static int hidraw_major;
34 static struct cdev hidraw_cdev;
35 static const struct class hidraw_class = {
36 .name = "hidraw",
37 };
38 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
39 static DECLARE_RWSEM(minors_rwsem);
40
41 static inline bool hidraw_is_revoked(struct hidraw_list *list)
42 {
43 return list->revoked;
44 }
45
46 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
47 {
48 struct hidraw_list *list = file->private_data;
49 int ret = 0, len;
50 DECLARE_WAITQUEUE(wait, current);
51
52 if (hidraw_is_revoked(list))
53 return -ENODEV;
54
55 mutex_lock(&list->read_mutex);
56
57 while (ret == 0) {
58 if (list->head == list->tail) {
59 add_wait_queue(&list->hidraw->wait, &wait);
60 set_current_state(TASK_INTERRUPTIBLE);
61
62 while (list->head == list->tail) {
63 if (signal_pending(current)) {
64 ret = -ERESTARTSYS;
65 break;
66 }
67 if (!list->hidraw->exist) {
68 ret = -EIO;
69 break;
70 }
71 if (file->f_flags & O_NONBLOCK) {
72 ret = -EAGAIN;
73 break;
74 }
75
76 /* allow O_NONBLOCK to work well from other threads */
77 mutex_unlock(&list->read_mutex);
78 schedule();
79 mutex_lock(&list->read_mutex);
80 set_current_state(TASK_INTERRUPTIBLE);
81 }
82
83 set_current_state(TASK_RUNNING);
84 remove_wait_queue(&list->hidraw->wait, &wait);
85 }
86
87 if (ret)
88 goto out;
89
90 len = list->buffer[list->tail].len > count ?
91 count : list->buffer[list->tail].len;
92
93 if (list->buffer[list->tail].value) {
94 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
95 ret = -EFAULT;
96 goto out;
97 }
98 ret = len;
99 }
100
101 kfree(list->buffer[list->tail].value);
102 list->buffer[list->tail].value = NULL;
103 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
104 }
105 out:
106 mutex_unlock(&list->read_mutex);
107 return ret;
108 }
109
110 /*
111 * The first byte of the report buffer is expected to be a report number.
112 */
113 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
114 {
115 unsigned int minor = iminor(file_inode(file));
116 struct hid_device *dev;
117 __u8 *buf;
118 int ret = 0;
119
120 lockdep_assert_held(&minors_rwsem);
121
122 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
123 ret = -ENODEV;
124 goto out;
125 }
126
127 dev = hidraw_table[minor]->hid;
128
129 if (count > HID_MAX_BUFFER_SIZE) {
130 hid_warn(dev, "pid %d passed too large report\n",
131 task_pid_nr(current));
132 ret = -EINVAL;
133 goto out;
134 }
135
136 if (count < 2) {
137 hid_warn(dev, "pid %d passed too short report\n",
138 task_pid_nr(current));
139 ret = -EINVAL;
140 goto out;
141 }
142
143 buf = memdup_user(buffer, count);
144 if (IS_ERR(buf)) {
145 ret = PTR_ERR(buf);
146 goto out;
147 }
148
149 if ((report_type == HID_OUTPUT_REPORT) &&
150 !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
151 ret = __hid_hw_output_report(dev, buf, count, (u64)(long)file, false);
152 /*
153 * compatibility with old implementation of USB-HID and I2C-HID:
154 * if the device does not support receiving output reports,
155 * on an interrupt endpoint, fallback to SET_REPORT HID command.
156 */
157 if (ret != -ENOSYS)
158 goto out_free;
159 }
160
161 ret = __hid_hw_raw_request(dev, buf[0], buf, count, report_type,
162 HID_REQ_SET_REPORT, (u64)(long)file, false);
163
164 out_free:
165 kfree(buf);
166 out:
167 return ret;
168 }
169
170 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
171 {
172 struct hidraw_list *list = file->private_data;
173 ssize_t ret;
174 down_read(&minors_rwsem);
175 if (hidraw_is_revoked(list))
176 ret = -ENODEV;
177 else
178 ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
179 up_read(&minors_rwsem);
180 return ret;
181 }
182
183
184 /*
185 * This function performs a Get_Report transfer over the control endpoint
186 * per section 7.2.1 of the HID specification, version 1.1. The first byte
187 * of buffer is the report number to request, or 0x0 if the device does not
188 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
189 * or HID_INPUT_REPORT.
190 */
191 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
192 {
193 unsigned int minor = iminor(file_inode(file));
194 struct hid_device *dev;
195 __u8 *buf;
196 int ret = 0, len;
197 unsigned char report_number;
198
199 lockdep_assert_held(&minors_rwsem);
200
201 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
202 ret = -ENODEV;
203 goto out;
204 }
205
206 dev = hidraw_table[minor]->hid;
207
208 if (!dev->ll_driver->raw_request) {
209 ret = -ENODEV;
210 goto out;
211 }
212
213 if (count > HID_MAX_BUFFER_SIZE) {
214 hid_warn(dev, "pid %d passed too large report\n",
215 task_pid_nr(current));
216 ret = -EINVAL;
217 goto out;
218 }
219
220 if (count < 2) {
221 hid_warn(dev, "pid %d passed too short report\n",
222 task_pid_nr(current));
223 ret = -EINVAL;
224 goto out;
225 }
226
227 buf = kmalloc(count, GFP_KERNEL);
228 if (!buf) {
229 ret = -ENOMEM;
230 goto out;
231 }
232
233 /*
234 * Read the first byte from the user. This is the report number,
235 * which is passed to hid_hw_raw_request().
236 */
237 if (copy_from_user(&report_number, buffer, 1)) {
238 ret = -EFAULT;
239 goto out_free;
240 }
241
242 ret = __hid_hw_raw_request(dev, report_number, buf, count, report_type,
243 HID_REQ_GET_REPORT, (u64)(long)file, false);
244
245 if (ret < 0)
246 goto out_free;
247
248 len = (ret < count) ? ret : count;
249
250 if (copy_to_user(buffer, buf, len)) {
251 ret = -EFAULT;
252 goto out_free;
253 }
254
255 ret = len;
256
257 out_free:
258 kfree(buf);
259 out:
260 return ret;
261 }
262
263 static __poll_t hidraw_poll(struct file *file, poll_table *wait)
264 {
265 struct hidraw_list *list = file->private_data;
266 __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* hidraw is always writable */
267
268 poll_wait(file, &list->hidraw->wait, wait);
269 if (list->head != list->tail)
270 mask |= EPOLLIN | EPOLLRDNORM;
271 if (!list->hidraw->exist || hidraw_is_revoked(list))
272 mask |= EPOLLERR | EPOLLHUP;
273 return mask;
274 }
275
276 static int hidraw_open(struct inode *inode, struct file *file)
277 {
278 unsigned int minor = iminor(inode);
279 struct hidraw *dev;
280 struct hidraw_list *list;
281 unsigned long flags;
282 int err = 0;
283
284 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
285 err = -ENOMEM;
286 goto out;
287 }
288
289 /*
290 * Technically not writing to the hidraw_table but a write lock is
291 * required to protect the device refcount. This is symmetrical to
292 * hidraw_release().
293 */
294 down_write(&minors_rwsem);
295 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
296 err = -ENODEV;
297 goto out_unlock;
298 }
299
300 dev = hidraw_table[minor];
301 if (!dev->open++) {
302 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
303 if (err < 0) {
304 dev->open--;
305 goto out_unlock;
306 }
307
308 err = hid_hw_open(dev->hid);
309 if (err < 0) {
310 hid_hw_power(dev->hid, PM_HINT_NORMAL);
311 dev->open--;
312 goto out_unlock;
313 }
314 }
315
316 list->hidraw = hidraw_table[minor];
317 mutex_init(&list->read_mutex);
318 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
319 list_add_tail(&list->node, &hidraw_table[minor]->list);
320 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
321 file->private_data = list;
322 out_unlock:
323 up_write(&minors_rwsem);
324 out:
325 if (err < 0)
326 kfree(list);
327 return err;
328
329 }
330
331 static int hidraw_fasync(int fd, struct file *file, int on)
332 {
333 struct hidraw_list *list = file->private_data;
334
335 if (hidraw_is_revoked(list))
336 return -ENODEV;
337
338 return fasync_helper(fd, file, on, &list->fasync);
339 }
340
341 static void drop_ref(struct hidraw *hidraw, int exists_bit)
342 {
343 if (exists_bit) {
344 hidraw->exist = 0;
345 if (hidraw->open) {
346 hid_hw_close(hidraw->hid);
347 wake_up_interruptible(&hidraw->wait);
348 }
349 device_destroy(&hidraw_class,
350 MKDEV(hidraw_major, hidraw->minor));
351 } else {
352 --hidraw->open;
353 }
354 if (!hidraw->open) {
355 if (!hidraw->exist) {
356 hidraw_table[hidraw->minor] = NULL;
357 kfree(hidraw);
358 } else {
359 /* close device for last reader */
360 hid_hw_close(hidraw->hid);
361 hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
362 }
363 }
364 }
365
366 static int hidraw_release(struct inode * inode, struct file * file)
367 {
368 unsigned int minor = iminor(inode);
369 struct hidraw_list *list = file->private_data;
370 unsigned long flags;
371
372 down_write(&minors_rwsem);
373
374 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
375 while (list->tail != list->head) {
376 kfree(list->buffer[list->tail].value);
377 list->buffer[list->tail].value = NULL;
378 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
379 }
380 list_del(&list->node);
381 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
382 kfree(list);
383
384 drop_ref(hidraw_table[minor], 0);
385
386 up_write(&minors_rwsem);
387 return 0;
388 }
389
390 static int hidraw_revoke(struct hidraw_list *list)
391 {
392 list->revoked = true;
393
394 return 0;
395 }
396
397 static long hidraw_ioctl(struct file *file, unsigned int cmd,
398 unsigned long arg)
399 {
400 struct inode *inode = file_inode(file);
401 unsigned int minor = iminor(inode);
402 long ret = 0;
403 struct hidraw *dev;
404 struct hidraw_list *list = file->private_data;
405 void __user *user_arg = (void __user*) arg;
406
407 down_read(&minors_rwsem);
408 dev = hidraw_table[minor];
409 if (!dev || !dev->exist || hidraw_is_revoked(list)) {
410 ret = -ENODEV;
411 goto out;
412 }
413
414 switch (cmd) {
415 case HIDIOCGRDESCSIZE:
416 if (put_user(dev->hid->rsize, (int __user *)arg))
417 ret = -EFAULT;
418 break;
419
420 case HIDIOCGRDESC:
421 {
422 __u32 len;
423
424 if (get_user(len, (int __user *)arg))
425 ret = -EFAULT;
426 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
427 ret = -EINVAL;
428 else if (copy_to_user(user_arg + offsetof(
429 struct hidraw_report_descriptor,
430 value[0]),
431 dev->hid->rdesc,
432 min(dev->hid->rsize, len)))
433 ret = -EFAULT;
434 break;
435 }
436 case HIDIOCGRAWINFO:
437 {
438 struct hidraw_devinfo dinfo;
439
440 dinfo.bustype = dev->hid->bus;
441 dinfo.vendor = dev->hid->vendor;
442 dinfo.product = dev->hid->product;
443 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
444 ret = -EFAULT;
445 break;
446 }
447 case HIDIOCREVOKE:
448 {
449 if (user_arg)
450 ret = -EINVAL;
451 else
452 ret = hidraw_revoke(list);
453 break;
454 }
455 default:
456 {
457 struct hid_device *hid = dev->hid;
458 if (_IOC_TYPE(cmd) != 'H') {
459 ret = -EINVAL;
460 break;
461 }
462
463 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
464 int len = _IOC_SIZE(cmd);
465 ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
466 break;
467 }
468 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
469 int len = _IOC_SIZE(cmd);
470 ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
471 break;
472 }
473
474 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSINPUT(0))) {
475 int len = _IOC_SIZE(cmd);
476 ret = hidraw_send_report(file, user_arg, len, HID_INPUT_REPORT);
477 break;
478 }
479 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGINPUT(0))) {
480 int len = _IOC_SIZE(cmd);
481 ret = hidraw_get_report(file, user_arg, len, HID_INPUT_REPORT);
482 break;
483 }
484
485 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSOUTPUT(0))) {
486 int len = _IOC_SIZE(cmd);
487 ret = hidraw_send_report(file, user_arg, len, HID_OUTPUT_REPORT);
488 break;
489 }
490 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGOUTPUT(0))) {
491 int len = _IOC_SIZE(cmd);
492 ret = hidraw_get_report(file, user_arg, len, HID_OUTPUT_REPORT);
493 break;
494 }
495
496 /* Begin Read-only ioctls. */
497 if (_IOC_DIR(cmd) != _IOC_READ) {
498 ret = -EINVAL;
499 break;
500 }
501
502 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
503 int len = strlen(hid->name) + 1;
504 if (len > _IOC_SIZE(cmd))
505 len = _IOC_SIZE(cmd);
506 ret = copy_to_user(user_arg, hid->name, len) ?
507 -EFAULT : len;
508 break;
509 }
510
511 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
512 int len = strlen(hid->phys) + 1;
513 if (len > _IOC_SIZE(cmd))
514 len = _IOC_SIZE(cmd);
515 ret = copy_to_user(user_arg, hid->phys, len) ?
516 -EFAULT : len;
517 break;
518 }
519
520 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWUNIQ(0))) {
521 int len = strlen(hid->uniq) + 1;
522 if (len > _IOC_SIZE(cmd))
523 len = _IOC_SIZE(cmd);
524 ret = copy_to_user(user_arg, hid->uniq, len) ?
525 -EFAULT : len;
526 break;
527 }
528 }
529
530 ret = -ENOTTY;
531 }
532 out:
533 up_read(&minors_rwsem);
534 return ret;
535 }
536
537 static const struct file_operations hidraw_ops = {
538 .owner = THIS_MODULE,
539 .read = hidraw_read,
540 .write = hidraw_write,
541 .poll = hidraw_poll,
542 .open = hidraw_open,
543 .release = hidraw_release,
544 .unlocked_ioctl = hidraw_ioctl,
545 .fasync = hidraw_fasync,
546 .compat_ioctl = compat_ptr_ioctl,
547 .llseek = noop_llseek,
548 };
549
550 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
551 {
552 struct hidraw *dev = hid->hidraw;
553 struct hidraw_list *list;
554 int ret = 0;
555 unsigned long flags;
556
557 spin_lock_irqsave(&dev->list_lock, flags);
558 list_for_each_entry(list, &dev->list, node) {
559 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
560
561 if (hidraw_is_revoked(list) || new_head == list->tail)
562 continue;
563
564 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
565 ret = -ENOMEM;
566 break;
567 }
568 list->buffer[list->head].len = len;
569 list->head = new_head;
570 kill_fasync(&list->fasync, SIGIO, POLL_IN);
571 }
572 spin_unlock_irqrestore(&dev->list_lock, flags);
573
574 wake_up_interruptible(&dev->wait);
575 return ret;
576 }
577 EXPORT_SYMBOL_GPL(hidraw_report_event);
578
579 int hidraw_connect(struct hid_device *hid)
580 {
581 int minor, result;
582 struct hidraw *dev;
583
584 /* we accept any HID device, all applications */
585
586 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
587 if (!dev)
588 return -ENOMEM;
589
590 result = -EINVAL;
591
592 down_write(&minors_rwsem);
593
594 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
595 if (hidraw_table[minor])
596 continue;
597 hidraw_table[minor] = dev;
598 result = 0;
599 break;
600 }
601
602 if (result) {
603 up_write(&minors_rwsem);
604 kfree(dev);
605 goto out;
606 }
607
608 dev->dev = device_create(&hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
609 NULL, "%s%d", "hidraw", minor);
610
611 if (IS_ERR(dev->dev)) {
612 hidraw_table[minor] = NULL;
613 up_write(&minors_rwsem);
614 result = PTR_ERR(dev->dev);
615 kfree(dev);
616 goto out;
617 }
618
619 init_waitqueue_head(&dev->wait);
620 spin_lock_init(&dev->list_lock);
621 INIT_LIST_HEAD(&dev->list);
622
623 dev->hid = hid;
624 dev->minor = minor;
625
626 dev->exist = 1;
627 hid->hidraw = dev;
628
629 up_write(&minors_rwsem);
630 out:
631 return result;
632
633 }
634 EXPORT_SYMBOL_GPL(hidraw_connect);
635
636 void hidraw_disconnect(struct hid_device *hid)
637 {
638 struct hidraw *hidraw = hid->hidraw;
639
640 down_write(&minors_rwsem);
641
642 drop_ref(hidraw, 1);
643
644 up_write(&minors_rwsem);
645 }
646 EXPORT_SYMBOL_GPL(hidraw_disconnect);
647
648 int __init hidraw_init(void)
649 {
650 int result;
651 dev_t dev_id;
652
653 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
654 HIDRAW_MAX_DEVICES, "hidraw");
655 if (result < 0) {
656 pr_warn("can't get major number\n");
657 goto out;
658 }
659
660 hidraw_major = MAJOR(dev_id);
661
662 result = class_register(&hidraw_class);
663 if (result)
664 goto error_cdev;
665
666 cdev_init(&hidraw_cdev, &hidraw_ops);
667 result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
668 if (result < 0)
669 goto error_class;
670
671 pr_info("raw HID events driver (C) Jiri Kosina\n");
672 out:
673 return result;
674
675 error_class:
676 class_unregister(&hidraw_class);
677 error_cdev:
678 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
679 goto out;
680 }
681
682 void hidraw_exit(void)
683 {
684 dev_t dev_id = MKDEV(hidraw_major, 0);
685
686 cdev_del(&hidraw_cdev);
687 class_unregister(&hidraw_class);
688 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
689
690 }
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