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1 | /* | |
2 | * HID raw devices, giving access to raw HID events. | |
3 | * | |
4 | * In comparison to hiddev, this device does not process the | |
5 | * hid events at all (no parsing, no lookups). This lets applications | |
6 | * to work on raw hid events as they want to, and avoids a need to | |
7 | * use a transport-specific userspace libhid/libusb libraries. | |
8 | * | |
9 | * Copyright (c) 2007 Jiri Kosina | |
10 | */ | |
11 | ||
12 | /* | |
13 | * This program is free software; you can redistribute it and/or modify it | |
14 | * under the terms and conditions of the GNU General Public License, | |
15 | * version 2, as published by the Free Software Foundation. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along with | |
18 | * this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
20 | */ | |
21 | ||
22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
23 | ||
24 | #include <linux/fs.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/cdev.h> | |
30 | #include <linux/poll.h> | |
31 | #include <linux/device.h> | |
32 | #include <linux/major.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/hid.h> | |
35 | #include <linux/mutex.h> | |
36 | #include <linux/sched.h> | |
37 | ||
38 | #include <linux/hidraw.h> | |
39 | ||
40 | static int hidraw_major; | |
41 | static struct cdev hidraw_cdev; | |
42 | static struct class *hidraw_class; | |
43 | static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; | |
44 | static DEFINE_MUTEX(minors_lock); | |
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 | mutex_lock(&list->read_mutex); | |
53 | ||
54 | while (ret == 0) { | |
55 | if (list->head == list->tail) { | |
56 | add_wait_queue(&list->hidraw->wait, &wait); | |
57 | set_current_state(TASK_INTERRUPTIBLE); | |
58 | ||
59 | while (list->head == list->tail) { | |
60 | if (file->f_flags & O_NONBLOCK) { | |
61 | ret = -EAGAIN; | |
62 | break; | |
63 | } | |
64 | if (signal_pending(current)) { | |
65 | ret = -ERESTARTSYS; | |
66 | break; | |
67 | } | |
68 | if (!list->hidraw->exist) { | |
69 | ret = -EIO; | |
70 | break; | |
71 | } | |
72 | ||
73 | /* allow O_NONBLOCK to work well from other threads */ | |
74 | mutex_unlock(&list->read_mutex); | |
75 | schedule(); | |
76 | mutex_lock(&list->read_mutex); | |
77 | set_current_state(TASK_INTERRUPTIBLE); | |
78 | } | |
79 | ||
80 | set_current_state(TASK_RUNNING); | |
81 | remove_wait_queue(&list->hidraw->wait, &wait); | |
82 | } | |
83 | ||
84 | if (ret) | |
85 | goto out; | |
86 | ||
87 | len = list->buffer[list->tail].len > count ? | |
88 | count : list->buffer[list->tail].len; | |
89 | ||
90 | if (list->buffer[list->tail].value) { | |
91 | if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { | |
92 | ret = -EFAULT; | |
93 | goto out; | |
94 | } | |
95 | ret = len; | |
96 | } | |
97 | ||
98 | kfree(list->buffer[list->tail].value); | |
99 | list->buffer[list->tail].value = NULL; | |
100 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
101 | } | |
102 | out: | |
103 | mutex_unlock(&list->read_mutex); | |
104 | return ret; | |
105 | } | |
106 | ||
107 | /* The first byte is expected to be a report number. | |
108 | * This function is to be called with the minors_lock mutex held */ | |
109 | static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type) | |
110 | { | |
111 | unsigned int minor = iminor(file->f_path.dentry->d_inode); | |
112 | struct hid_device *dev; | |
113 | __u8 *buf; | |
114 | int ret = 0; | |
115 | ||
116 | if (!hidraw_table[minor]) { | |
117 | ret = -ENODEV; | |
118 | goto out; | |
119 | } | |
120 | ||
121 | dev = hidraw_table[minor]->hid; | |
122 | ||
123 | if (!dev->hid_output_raw_report) { | |
124 | ret = -ENODEV; | |
125 | goto out; | |
126 | } | |
127 | ||
128 | if (count > HID_MAX_BUFFER_SIZE) { | |
129 | hid_warn(dev, "pid %d passed too large report\n", | |
130 | task_pid_nr(current)); | |
131 | ret = -EINVAL; | |
132 | goto out; | |
133 | } | |
134 | ||
135 | if (count < 2) { | |
136 | hid_warn(dev, "pid %d passed too short report\n", | |
137 | task_pid_nr(current)); | |
138 | ret = -EINVAL; | |
139 | goto out; | |
140 | } | |
141 | ||
142 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); | |
143 | if (!buf) { | |
144 | ret = -ENOMEM; | |
145 | goto out; | |
146 | } | |
147 | ||
148 | if (copy_from_user(buf, buffer, count)) { | |
149 | ret = -EFAULT; | |
150 | goto out_free; | |
151 | } | |
152 | ||
153 | ret = dev->hid_output_raw_report(dev, buf, count, report_type); | |
154 | out_free: | |
155 | kfree(buf); | |
156 | out: | |
157 | return ret; | |
158 | } | |
159 | ||
160 | /* the first byte is expected to be a report number */ | |
161 | static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) | |
162 | { | |
163 | ssize_t ret; | |
164 | mutex_lock(&minors_lock); | |
165 | ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT); | |
166 | mutex_unlock(&minors_lock); | |
167 | return ret; | |
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. This function is to be called with the minors_lock | |
176 | * mutex held. */ | |
177 | static 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->f_path.dentry->d_inode); | |
180 | struct hid_device *dev; | |
181 | __u8 *buf; | |
182 | int ret = 0, len; | |
183 | unsigned char report_number; | |
184 | ||
185 | dev = hidraw_table[minor]->hid; | |
186 | ||
187 | if (!dev->hid_get_raw_report) { | |
188 | ret = -ENODEV; | |
189 | goto out; | |
190 | } | |
191 | ||
192 | if (count > HID_MAX_BUFFER_SIZE) { | |
193 | printk(KERN_WARNING "hidraw: pid %d passed too large report\n", | |
194 | task_pid_nr(current)); | |
195 | ret = -EINVAL; | |
196 | goto out; | |
197 | } | |
198 | ||
199 | if (count < 2) { | |
200 | printk(KERN_WARNING "hidraw: pid %d passed too short report\n", | |
201 | task_pid_nr(current)); | |
202 | ret = -EINVAL; | |
203 | goto out; | |
204 | } | |
205 | ||
206 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); | |
207 | if (!buf) { | |
208 | ret = -ENOMEM; | |
209 | goto out; | |
210 | } | |
211 | ||
212 | /* Read the first byte from the user. This is the report number, | |
213 | * which is passed to dev->hid_get_raw_report(). */ | |
214 | if (copy_from_user(&report_number, buffer, 1)) { | |
215 | ret = -EFAULT; | |
216 | goto out_free; | |
217 | } | |
218 | ||
219 | ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type); | |
220 | ||
221 | if (ret < 0) | |
222 | goto out_free; | |
223 | ||
224 | len = (ret < count) ? ret : count; | |
225 | ||
226 | if (copy_to_user(buffer, buf, len)) { | |
227 | ret = -EFAULT; | |
228 | goto out_free; | |
229 | } | |
230 | ||
231 | ret = len; | |
232 | ||
233 | out_free: | |
234 | kfree(buf); | |
235 | out: | |
236 | return ret; | |
237 | } | |
238 | ||
239 | static unsigned int hidraw_poll(struct file *file, poll_table *wait) | |
240 | { | |
241 | struct hidraw_list *list = file->private_data; | |
242 | ||
243 | poll_wait(file, &list->hidraw->wait, wait); | |
244 | if (list->head != list->tail) | |
245 | return POLLIN | POLLRDNORM; | |
246 | if (!list->hidraw->exist) | |
247 | return POLLERR | POLLHUP; | |
248 | return 0; | |
249 | } | |
250 | ||
251 | static int hidraw_open(struct inode *inode, struct file *file) | |
252 | { | |
253 | unsigned int minor = iminor(inode); | |
254 | struct hidraw *dev; | |
255 | struct hidraw_list *list; | |
256 | int err = 0; | |
257 | ||
258 | if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { | |
259 | err = -ENOMEM; | |
260 | goto out; | |
261 | } | |
262 | ||
263 | mutex_lock(&minors_lock); | |
264 | if (!hidraw_table[minor]) { | |
265 | err = -ENODEV; | |
266 | goto out_unlock; | |
267 | } | |
268 | ||
269 | list->hidraw = hidraw_table[minor]; | |
270 | mutex_init(&list->read_mutex); | |
271 | list_add_tail(&list->node, &hidraw_table[minor]->list); | |
272 | file->private_data = list; | |
273 | ||
274 | dev = hidraw_table[minor]; | |
275 | if (!dev->open++) { | |
276 | err = hid_hw_power(dev->hid, PM_HINT_FULLON); | |
277 | if (err < 0) { | |
278 | dev->open--; | |
279 | goto out_unlock; | |
280 | } | |
281 | ||
282 | err = hid_hw_open(dev->hid); | |
283 | if (err < 0) { | |
284 | hid_hw_power(dev->hid, PM_HINT_NORMAL); | |
285 | dev->open--; | |
286 | } | |
287 | } | |
288 | ||
289 | out_unlock: | |
290 | mutex_unlock(&minors_lock); | |
291 | out: | |
292 | if (err < 0) | |
293 | kfree(list); | |
294 | return err; | |
295 | ||
296 | } | |
297 | ||
298 | static int hidraw_release(struct inode * inode, struct file * file) | |
299 | { | |
300 | unsigned int minor = iminor(inode); | |
301 | struct hidraw *dev; | |
302 | struct hidraw_list *list = file->private_data; | |
303 | int ret; | |
304 | int i; | |
305 | ||
306 | mutex_lock(&minors_lock); | |
307 | if (!hidraw_table[minor]) { | |
308 | ret = -ENODEV; | |
309 | goto unlock; | |
310 | } | |
311 | ||
312 | list_del(&list->node); | |
313 | dev = hidraw_table[minor]; | |
314 | if (!--dev->open) { | |
315 | if (list->hidraw->exist) { | |
316 | hid_hw_power(dev->hid, PM_HINT_NORMAL); | |
317 | hid_hw_close(dev->hid); | |
318 | } else { | |
319 | kfree(list->hidraw); | |
320 | } | |
321 | } | |
322 | ||
323 | for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i) | |
324 | kfree(list->buffer[i].value); | |
325 | kfree(list); | |
326 | ret = 0; | |
327 | unlock: | |
328 | mutex_unlock(&minors_lock); | |
329 | ||
330 | return ret; | |
331 | } | |
332 | ||
333 | static long hidraw_ioctl(struct file *file, unsigned int cmd, | |
334 | unsigned long arg) | |
335 | { | |
336 | struct inode *inode = file->f_path.dentry->d_inode; | |
337 | unsigned int minor = iminor(inode); | |
338 | long ret = 0; | |
339 | struct hidraw *dev; | |
340 | void __user *user_arg = (void __user*) arg; | |
341 | ||
342 | mutex_lock(&minors_lock); | |
343 | dev = hidraw_table[minor]; | |
344 | if (!dev) { | |
345 | ret = -ENODEV; | |
346 | goto out; | |
347 | } | |
348 | ||
349 | switch (cmd) { | |
350 | case HIDIOCGRDESCSIZE: | |
351 | if (put_user(dev->hid->rsize, (int __user *)arg)) | |
352 | ret = -EFAULT; | |
353 | break; | |
354 | ||
355 | case HIDIOCGRDESC: | |
356 | { | |
357 | __u32 len; | |
358 | ||
359 | if (get_user(len, (int __user *)arg)) | |
360 | ret = -EFAULT; | |
361 | else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) | |
362 | ret = -EINVAL; | |
363 | else if (copy_to_user(user_arg + offsetof( | |
364 | struct hidraw_report_descriptor, | |
365 | value[0]), | |
366 | dev->hid->rdesc, | |
367 | min(dev->hid->rsize, len))) | |
368 | ret = -EFAULT; | |
369 | break; | |
370 | } | |
371 | case HIDIOCGRAWINFO: | |
372 | { | |
373 | struct hidraw_devinfo dinfo; | |
374 | ||
375 | dinfo.bustype = dev->hid->bus; | |
376 | dinfo.vendor = dev->hid->vendor; | |
377 | dinfo.product = dev->hid->product; | |
378 | if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) | |
379 | ret = -EFAULT; | |
380 | break; | |
381 | } | |
382 | default: | |
383 | { | |
384 | struct hid_device *hid = dev->hid; | |
385 | if (_IOC_TYPE(cmd) != 'H') { | |
386 | ret = -EINVAL; | |
387 | break; | |
388 | } | |
389 | ||
390 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) { | |
391 | int len = _IOC_SIZE(cmd); | |
392 | ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT); | |
393 | break; | |
394 | } | |
395 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) { | |
396 | int len = _IOC_SIZE(cmd); | |
397 | ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT); | |
398 | break; | |
399 | } | |
400 | ||
401 | /* Begin Read-only ioctls. */ | |
402 | if (_IOC_DIR(cmd) != _IOC_READ) { | |
403 | ret = -EINVAL; | |
404 | break; | |
405 | } | |
406 | ||
407 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { | |
408 | int len = strlen(hid->name) + 1; | |
409 | if (len > _IOC_SIZE(cmd)) | |
410 | len = _IOC_SIZE(cmd); | |
411 | ret = copy_to_user(user_arg, hid->name, len) ? | |
412 | -EFAULT : len; | |
413 | break; | |
414 | } | |
415 | ||
416 | if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { | |
417 | int len = strlen(hid->phys) + 1; | |
418 | if (len > _IOC_SIZE(cmd)) | |
419 | len = _IOC_SIZE(cmd); | |
420 | ret = copy_to_user(user_arg, hid->phys, len) ? | |
421 | -EFAULT : len; | |
422 | break; | |
423 | } | |
424 | } | |
425 | ||
426 | ret = -ENOTTY; | |
427 | } | |
428 | out: | |
429 | mutex_unlock(&minors_lock); | |
430 | return ret; | |
431 | } | |
432 | ||
433 | static const struct file_operations hidraw_ops = { | |
434 | .owner = THIS_MODULE, | |
435 | .read = hidraw_read, | |
436 | .write = hidraw_write, | |
437 | .poll = hidraw_poll, | |
438 | .open = hidraw_open, | |
439 | .release = hidraw_release, | |
440 | .unlocked_ioctl = hidraw_ioctl, | |
441 | #ifdef CONFIG_COMPAT | |
442 | .compat_ioctl = hidraw_ioctl, | |
443 | #endif | |
444 | .llseek = noop_llseek, | |
445 | }; | |
446 | ||
447 | int hidraw_report_event(struct hid_device *hid, u8 *data, int len) | |
448 | { | |
449 | struct hidraw *dev = hid->hidraw; | |
450 | struct hidraw_list *list; | |
451 | int ret = 0; | |
452 | ||
453 | list_for_each_entry(list, &dev->list, node) { | |
454 | int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
455 | ||
456 | if (new_head == list->tail) | |
457 | continue; | |
458 | ||
459 | if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) { | |
460 | ret = -ENOMEM; | |
461 | break; | |
462 | } | |
463 | list->buffer[list->head].len = len; | |
464 | list->head = new_head; | |
465 | kill_fasync(&list->fasync, SIGIO, POLL_IN); | |
466 | } | |
467 | ||
468 | wake_up_interruptible(&dev->wait); | |
469 | return ret; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(hidraw_report_event); | |
472 | ||
473 | int hidraw_connect(struct hid_device *hid) | |
474 | { | |
475 | int minor, result; | |
476 | struct hidraw *dev; | |
477 | ||
478 | /* we accept any HID device, no matter the applications */ | |
479 | ||
480 | dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); | |
481 | if (!dev) | |
482 | return -ENOMEM; | |
483 | ||
484 | result = -EINVAL; | |
485 | ||
486 | mutex_lock(&minors_lock); | |
487 | ||
488 | for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { | |
489 | if (hidraw_table[minor]) | |
490 | continue; | |
491 | hidraw_table[minor] = dev; | |
492 | result = 0; | |
493 | break; | |
494 | } | |
495 | ||
496 | if (result) { | |
497 | mutex_unlock(&minors_lock); | |
498 | kfree(dev); | |
499 | goto out; | |
500 | } | |
501 | ||
502 | dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor), | |
503 | NULL, "%s%d", "hidraw", minor); | |
504 | ||
505 | if (IS_ERR(dev->dev)) { | |
506 | hidraw_table[minor] = NULL; | |
507 | mutex_unlock(&minors_lock); | |
508 | result = PTR_ERR(dev->dev); | |
509 | kfree(dev); | |
510 | goto out; | |
511 | } | |
512 | ||
513 | mutex_unlock(&minors_lock); | |
514 | init_waitqueue_head(&dev->wait); | |
515 | INIT_LIST_HEAD(&dev->list); | |
516 | ||
517 | dev->hid = hid; | |
518 | dev->minor = minor; | |
519 | ||
520 | dev->exist = 1; | |
521 | hid->hidraw = dev; | |
522 | ||
523 | out: | |
524 | return result; | |
525 | ||
526 | } | |
527 | EXPORT_SYMBOL_GPL(hidraw_connect); | |
528 | ||
529 | void hidraw_disconnect(struct hid_device *hid) | |
530 | { | |
531 | struct hidraw *hidraw = hid->hidraw; | |
532 | ||
533 | mutex_lock(&minors_lock); | |
534 | hidraw->exist = 0; | |
535 | ||
536 | device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); | |
537 | ||
538 | hidraw_table[hidraw->minor] = NULL; | |
539 | ||
540 | if (hidraw->open) { | |
541 | hid_hw_close(hid); | |
542 | wake_up_interruptible(&hidraw->wait); | |
543 | } else { | |
544 | kfree(hidraw); | |
545 | } | |
546 | mutex_unlock(&minors_lock); | |
547 | } | |
548 | EXPORT_SYMBOL_GPL(hidraw_disconnect); | |
549 | ||
550 | int __init hidraw_init(void) | |
551 | { | |
552 | int result; | |
553 | dev_t dev_id; | |
554 | ||
555 | result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, | |
556 | HIDRAW_MAX_DEVICES, "hidraw"); | |
557 | ||
558 | hidraw_major = MAJOR(dev_id); | |
559 | ||
560 | if (result < 0) { | |
561 | pr_warn("can't get major number\n"); | |
562 | goto out; | |
563 | } | |
564 | ||
565 | hidraw_class = class_create(THIS_MODULE, "hidraw"); | |
566 | if (IS_ERR(hidraw_class)) { | |
567 | result = PTR_ERR(hidraw_class); | |
568 | goto error_cdev; | |
569 | } | |
570 | ||
571 | cdev_init(&hidraw_cdev, &hidraw_ops); | |
572 | result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); | |
573 | if (result < 0) | |
574 | goto error_class; | |
575 | ||
576 | out: | |
577 | return result; | |
578 | ||
579 | error_class: | |
580 | class_destroy(hidraw_class); | |
581 | error_cdev: | |
582 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); | |
583 | goto out; | |
584 | } | |
585 | ||
586 | void hidraw_exit(void) | |
587 | { | |
588 | dev_t dev_id = MKDEV(hidraw_major, 0); | |
589 | ||
590 | cdev_del(&hidraw_cdev); | |
591 | class_destroy(hidraw_class); | |
592 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); | |
593 | ||
594 | } |