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