1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) 2001 Paul Stewart
4 * Copyright (c) 2001 Vojtech Pavlik
6 * HID char devices, giving access to raw HID device events.
11 * Should you need to contact me, the author, you can do so either by
12 * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
15 #include <linux/poll.h>
16 #include <linux/slab.h>
17 #include <linux/sched/signal.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/input.h>
21 #include <linux/usb.h>
22 #include <linux/hid.h>
23 #include <linux/hiddev.h>
24 #include <linux/compat.h>
25 #include <linux/vmalloc.h>
26 #include <linux/nospec.h>
29 #ifdef CONFIG_USB_DYNAMIC_MINORS
30 #define HIDDEV_MINOR_BASE 0
31 #define HIDDEV_MINORS 256
33 #define HIDDEV_MINOR_BASE 96
34 #define HIDDEV_MINORS 16
36 #define HIDDEV_BUFFER_SIZE 2048
39 struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
43 struct fasync_struct *fasync;
44 struct hiddev *hiddev;
45 struct list_head node;
46 struct mutex thread_lock;
50 * Find a report, given the report's type and ID. The ID can be specified
51 * indirectly by REPORT_ID_FIRST (which returns the first report of the given
52 * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
53 * given type which follows old_id.
55 static struct hid_report *
56 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
58 unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
59 unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
60 struct hid_report_enum *report_enum;
61 struct hid_report *report;
62 struct list_head *list;
64 if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
65 rinfo->report_type > HID_REPORT_TYPE_MAX)
68 report_enum = hid->report_enum +
69 (rinfo->report_type - HID_REPORT_TYPE_MIN);
72 case 0: /* Nothing to do -- report_id is already set correctly */
75 case HID_REPORT_ID_FIRST:
76 if (list_empty(&report_enum->report_list))
79 list = report_enum->report_list.next;
80 report = list_entry(list, struct hid_report, list);
81 rinfo->report_id = report->id;
84 case HID_REPORT_ID_NEXT:
85 report = report_enum->report_id_hash[rid];
89 list = report->list.next;
90 if (list == &report_enum->report_list)
93 report = list_entry(list, struct hid_report, list);
94 rinfo->report_id = report->id;
101 return report_enum->report_id_hash[rinfo->report_id];
105 * Perform an exhaustive search of the report table for a usage, given its
108 static struct hid_field *
109 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
112 struct hid_report *report;
113 struct hid_report_enum *report_enum;
114 struct hid_field *field;
116 if (uref->report_type < HID_REPORT_TYPE_MIN ||
117 uref->report_type > HID_REPORT_TYPE_MAX)
120 report_enum = hid->report_enum +
121 (uref->report_type - HID_REPORT_TYPE_MIN);
123 list_for_each_entry(report, &report_enum->report_list, list) {
124 for (i = 0; i < report->maxfield; i++) {
125 field = report->field[i];
126 for (j = 0; j < field->maxusage; j++) {
127 if (field->usage[j].hid == uref->usage_code) {
128 uref->report_id = report->id;
129 uref->field_index = i;
130 uref->usage_index = j;
140 static void hiddev_send_event(struct hid_device *hid,
141 struct hiddev_usage_ref *uref)
143 struct hiddev *hiddev = hid->hiddev;
144 struct hiddev_list *list;
147 spin_lock_irqsave(&hiddev->list_lock, flags);
148 list_for_each_entry(list, &hiddev->list, node) {
149 if (uref->field_index != HID_FIELD_INDEX_NONE ||
150 (list->flags & HIDDEV_FLAG_REPORT) != 0) {
151 list->buffer[list->head] = *uref;
152 list->head = (list->head + 1) &
153 (HIDDEV_BUFFER_SIZE - 1);
154 kill_fasync(&list->fasync, SIGIO, POLL_IN);
157 spin_unlock_irqrestore(&hiddev->list_lock, flags);
159 wake_up_interruptible(&hiddev->wait);
163 * This is where hid.c calls into hiddev to pass an event that occurred over
166 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
167 struct hid_usage *usage, __s32 value)
169 unsigned type = field->report_type;
170 struct hiddev_usage_ref uref;
173 (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
174 ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
175 ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
176 uref.report_id = field->report->id;
177 uref.field_index = field->index;
178 uref.usage_index = (usage - field->usage);
179 uref.usage_code = usage->hid;
182 hiddev_send_event(hid, &uref);
184 EXPORT_SYMBOL_GPL(hiddev_hid_event);
186 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
188 unsigned type = report->type;
189 struct hiddev_usage_ref uref;
191 memset(&uref, 0, sizeof(uref));
193 (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
194 ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
195 ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
196 uref.report_id = report->id;
197 uref.field_index = HID_FIELD_INDEX_NONE;
199 hiddev_send_event(hid, &uref);
205 static int hiddev_fasync(int fd, struct file *file, int on)
207 struct hiddev_list *list = file->private_data;
209 return fasync_helper(fd, file, on, &list->fasync);
216 static int hiddev_release(struct inode * inode, struct file * file)
218 struct hiddev_list *list = file->private_data;
221 spin_lock_irqsave(&list->hiddev->list_lock, flags);
222 list_del(&list->node);
223 spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
225 mutex_lock(&list->hiddev->existancelock);
226 if (!--list->hiddev->open) {
227 if (list->hiddev->exist) {
228 hid_hw_close(list->hiddev->hid);
229 hid_hw_power(list->hiddev->hid, PM_HINT_NORMAL);
231 mutex_unlock(&list->hiddev->existancelock);
238 mutex_unlock(&list->hiddev->existancelock);
247 static int hiddev_open(struct inode *inode, struct file *file)
249 struct hiddev_list *list;
250 struct usb_interface *intf;
251 struct hid_device *hid;
252 struct hiddev *hiddev;
255 intf = usbhid_find_interface(iminor(inode));
258 hid = usb_get_intfdata(intf);
259 hiddev = hid->hiddev;
261 if (!(list = vzalloc(sizeof(struct hiddev_list))))
263 mutex_init(&list->thread_lock);
264 list->hiddev = hiddev;
265 file->private_data = list;
268 * no need for locking because the USB major number
269 * is shared which usbcore guards against disconnect
271 if (list->hiddev->exist) {
272 if (!list->hiddev->open++) {
273 res = hid_hw_open(hiddev->hid);
282 spin_lock_irq(&list->hiddev->list_lock);
283 list_add_tail(&list->node, &hiddev->list);
284 spin_unlock_irq(&list->hiddev->list_lock);
286 mutex_lock(&hiddev->existancelock);
287 if (!list->hiddev->open++)
288 if (list->hiddev->exist) {
289 struct hid_device *hid = hiddev->hid;
290 res = hid_hw_power(hid, PM_HINT_FULLON);
293 res = hid_hw_open(hid);
295 goto bail_normal_power;
297 mutex_unlock(&hiddev->existancelock);
300 hid_hw_power(hid, PM_HINT_NORMAL);
302 mutex_unlock(&hiddev->existancelock);
304 file->private_data = NULL;
312 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
320 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
323 struct hiddev_list *list = file->private_data;
327 event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
328 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
330 if (count < event_size)
333 /* lock against other threads */
334 retval = mutex_lock_interruptible(&list->thread_lock);
338 while (retval == 0) {
339 if (list->head == list->tail) {
340 prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
342 while (list->head == list->tail) {
343 if (signal_pending(current)) {
344 retval = -ERESTARTSYS;
347 if (!list->hiddev->exist) {
351 if (file->f_flags & O_NONBLOCK) {
356 /* let O_NONBLOCK tasks run */
357 mutex_unlock(&list->thread_lock);
359 if (mutex_lock_interruptible(&list->thread_lock)) {
360 finish_wait(&list->hiddev->wait, &wait);
363 set_current_state(TASK_INTERRUPTIBLE);
365 finish_wait(&list->hiddev->wait, &wait);
370 mutex_unlock(&list->thread_lock);
375 while (list->head != list->tail &&
376 retval + event_size <= count) {
377 if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
378 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
379 struct hiddev_event event;
381 event.hid = list->buffer[list->tail].usage_code;
382 event.value = list->buffer[list->tail].value;
383 if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
384 mutex_unlock(&list->thread_lock);
387 retval += sizeof(struct hiddev_event);
390 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
391 (list->flags & HIDDEV_FLAG_REPORT) != 0) {
393 if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
394 mutex_unlock(&list->thread_lock);
397 retval += sizeof(struct hiddev_usage_ref);
400 list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
404 mutex_unlock(&list->thread_lock);
411 * No kernel lock - fine
413 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
415 struct hiddev_list *list = file->private_data;
417 poll_wait(file, &list->hiddev->wait, wait);
418 if (list->head != list->tail)
419 return EPOLLIN | EPOLLRDNORM;
420 if (!list->hiddev->exist)
421 return EPOLLERR | EPOLLHUP;
428 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
430 struct hid_device *hid = hiddev->hid;
431 struct hiddev_report_info rinfo;
432 struct hiddev_usage_ref_multi *uref_multi = NULL;
433 struct hiddev_usage_ref *uref;
434 struct hid_report *report;
435 struct hid_field *field;
438 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
441 uref = &uref_multi->uref;
442 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
443 if (copy_from_user(uref_multi, user_arg,
444 sizeof(*uref_multi)))
447 if (copy_from_user(uref, user_arg, sizeof(*uref)))
453 rinfo.report_type = uref->report_type;
454 rinfo.report_id = uref->report_id;
455 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
458 if (uref->field_index >= report->maxfield)
460 uref->field_index = array_index_nospec(uref->field_index,
463 field = report->field[uref->field_index];
464 if (uref->usage_index >= field->maxusage)
466 uref->usage_index = array_index_nospec(uref->usage_index,
469 uref->usage_code = field->usage[uref->usage_index].hid;
471 if (copy_to_user(user_arg, uref, sizeof(*uref)))
477 if (cmd != HIDIOCGUSAGE &&
478 cmd != HIDIOCGUSAGES &&
479 uref->report_type == HID_REPORT_TYPE_INPUT)
482 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
483 field = hiddev_lookup_usage(hid, uref);
487 rinfo.report_type = uref->report_type;
488 rinfo.report_id = uref->report_id;
489 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
492 if (uref->field_index >= report->maxfield)
494 uref->field_index = array_index_nospec(uref->field_index,
497 field = report->field[uref->field_index];
499 if (cmd == HIDIOCGCOLLECTIONINDEX) {
500 if (uref->usage_index >= field->maxusage)
503 array_index_nospec(uref->usage_index,
505 } else if (uref->usage_index >= field->report_count)
509 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
510 if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
511 uref->usage_index + uref_multi->num_values >
516 array_index_nospec(uref->usage_index,
517 field->report_count -
518 uref_multi->num_values);
523 uref->value = field->value[uref->usage_index];
524 if (copy_to_user(user_arg, uref, sizeof(*uref)))
529 field->value[uref->usage_index] = uref->value;
532 case HIDIOCGCOLLECTIONINDEX:
533 i = field->usage[uref->usage_index].collection_index;
537 for (i = 0; i < uref_multi->num_values; i++)
538 uref_multi->values[i] =
539 field->value[uref->usage_index + i];
540 if (copy_to_user(user_arg, uref_multi,
541 sizeof(*uref_multi)))
545 for (i = 0; i < uref_multi->num_values; i++)
546 field->value[uref->usage_index + i] =
547 uref_multi->values[i];
563 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
565 struct hid_device *hid = hiddev->hid;
566 struct usb_device *dev = hid_to_usb_dev(hid);
570 if (get_user(idx, (int __user *)user_arg))
573 if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
576 if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
581 if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
591 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
593 struct hiddev_list *list = file->private_data;
594 struct hiddev *hiddev = list->hiddev;
595 struct hid_device *hid;
596 struct hiddev_collection_info cinfo;
597 struct hiddev_report_info rinfo;
598 struct hiddev_field_info finfo;
599 struct hiddev_devinfo dinfo;
600 struct hid_report *report;
601 struct hid_field *field;
602 void __user *user_arg = (void __user *)arg;
605 /* Called without BKL by compat methods so no BKL taken */
607 mutex_lock(&hiddev->existancelock);
608 if (!hiddev->exist) {
618 r = put_user(HID_VERSION, (int __user *)arg) ?
622 case HIDIOCAPPLICATION:
623 if (arg >= hid->maxapplication)
626 for (i = 0; i < hid->maxcollection; i++)
627 if (hid->collection[i].type ==
628 HID_COLLECTION_APPLICATION && arg-- == 0)
631 if (i < hid->maxcollection)
632 r = hid->collection[i].usage;
637 struct usb_device *dev = hid_to_usb_dev(hid);
638 struct usbhid_device *usbhid = hid->driver_data;
640 memset(&dinfo, 0, sizeof(dinfo));
642 dinfo.bustype = BUS_USB;
643 dinfo.busnum = dev->bus->busnum;
644 dinfo.devnum = dev->devnum;
645 dinfo.ifnum = usbhid->ifnum;
646 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
647 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
648 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
649 dinfo.num_applications = hid->maxapplication;
651 r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
657 r = put_user(list->flags, (int __user *)arg) ?
665 if (get_user(newflags, (int __user *)arg)) {
670 if ((newflags & ~HIDDEV_FLAGS) != 0 ||
671 ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
672 (newflags & HIDDEV_FLAG_UREF) == 0))
675 list->flags = newflags;
682 r = hiddev_ioctl_string(hiddev, cmd, user_arg);
685 case HIDIOCINITREPORT:
686 usbhid_init_reports(hid);
687 hiddev->initialized = true;
692 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
697 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
700 report = hiddev_lookup_report(hid, &rinfo);
704 hid_hw_request(hid, report, HID_REQ_GET_REPORT);
711 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
716 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
719 report = hiddev_lookup_report(hid, &rinfo);
723 hid_hw_request(hid, report, HID_REQ_SET_REPORT);
729 case HIDIOCGREPORTINFO:
730 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
735 report = hiddev_lookup_report(hid, &rinfo);
739 rinfo.num_fields = report->maxfield;
741 r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
745 case HIDIOCGFIELDINFO:
746 if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
751 rinfo.report_type = finfo.report_type;
752 rinfo.report_id = finfo.report_id;
754 report = hiddev_lookup_report(hid, &rinfo);
758 if (finfo.field_index >= report->maxfield)
760 finfo.field_index = array_index_nospec(finfo.field_index,
763 field = report->field[finfo.field_index];
764 memset(&finfo, 0, sizeof(finfo));
765 finfo.report_type = rinfo.report_type;
766 finfo.report_id = rinfo.report_id;
767 finfo.field_index = field->report_count - 1;
768 finfo.maxusage = field->maxusage;
769 finfo.flags = field->flags;
770 finfo.physical = field->physical;
771 finfo.logical = field->logical;
772 finfo.application = field->application;
773 finfo.logical_minimum = field->logical_minimum;
774 finfo.logical_maximum = field->logical_maximum;
775 finfo.physical_minimum = field->physical_minimum;
776 finfo.physical_maximum = field->physical_maximum;
777 finfo.unit_exponent = field->unit_exponent;
778 finfo.unit = field->unit;
780 r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
790 case HIDIOCGCOLLECTIONINDEX:
791 if (!hiddev->initialized) {
792 usbhid_init_reports(hid);
793 hiddev->initialized = true;
795 r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
798 case HIDIOCGCOLLECTIONINFO:
799 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
804 if (cinfo.index >= hid->maxcollection)
806 cinfo.index = array_index_nospec(cinfo.index,
809 cinfo.type = hid->collection[cinfo.index].type;
810 cinfo.usage = hid->collection[cinfo.index].usage;
811 cinfo.level = hid->collection[cinfo.index].level;
813 r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
818 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
821 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
822 int len = strlen(hid->name) + 1;
823 if (len > _IOC_SIZE(cmd))
824 len = _IOC_SIZE(cmd);
825 r = copy_to_user(user_arg, hid->name, len) ?
830 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
831 int len = strlen(hid->phys) + 1;
832 if (len > _IOC_SIZE(cmd))
833 len = _IOC_SIZE(cmd);
834 r = copy_to_user(user_arg, hid->phys, len) ?
841 mutex_unlock(&hiddev->existancelock);
846 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
848 return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
852 static const struct file_operations hiddev_fops = {
853 .owner = THIS_MODULE,
855 .write = hiddev_write,
858 .release = hiddev_release,
859 .unlocked_ioctl = hiddev_ioctl,
860 .fasync = hiddev_fasync,
862 .compat_ioctl = hiddev_compat_ioctl,
864 .llseek = noop_llseek,
867 static char *hiddev_devnode(struct device *dev, umode_t *mode)
869 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
872 static struct usb_class_driver hiddev_class = {
874 .devnode = hiddev_devnode,
875 .fops = &hiddev_fops,
876 .minor_base = HIDDEV_MINOR_BASE,
880 * This is where hid.c calls us to connect a hid device to the hiddev driver
882 int hiddev_connect(struct hid_device *hid, unsigned int force)
884 struct hiddev *hiddev;
885 struct usbhid_device *usbhid = hid->driver_data;
890 for (i = 0; i < hid->maxcollection; i++)
891 if (hid->collection[i].type ==
892 HID_COLLECTION_APPLICATION &&
893 !IS_INPUT_APPLICATION(hid->collection[i].usage))
896 if (i == hid->maxcollection)
900 if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
903 init_waitqueue_head(&hiddev->wait);
904 INIT_LIST_HEAD(&hiddev->list);
905 spin_lock_init(&hiddev->list_lock);
906 mutex_init(&hiddev->existancelock);
907 hid->hiddev = hiddev;
910 retval = usb_register_dev(usbhid->intf, &hiddev_class);
912 hid_err(hid, "Not able to get a minor for this device\n");
919 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
922 hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
924 hiddev->minor = usbhid->intf->minor;
930 * This is where hid.c calls us to disconnect a hiddev device from the
931 * corresponding hid device (usually because the usb device has disconnected)
933 static struct usb_class_driver hiddev_class;
934 void hiddev_disconnect(struct hid_device *hid)
936 struct hiddev *hiddev = hid->hiddev;
937 struct usbhid_device *usbhid = hid->driver_data;
939 usb_deregister_dev(usbhid->intf, &hiddev_class);
941 mutex_lock(&hiddev->existancelock);
945 mutex_unlock(&hiddev->existancelock);
946 hid_hw_close(hiddev->hid);
947 wake_up_interruptible(&hiddev->wait);
949 mutex_unlock(&hiddev->existancelock);