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);
288 * recheck exist with existance lock held to
289 * avoid opening a disconnected device
291 if (!list->hiddev->exist) {
295 if (!list->hiddev->open++)
296 if (list->hiddev->exist) {
297 struct hid_device *hid = hiddev->hid;
298 res = hid_hw_power(hid, PM_HINT_FULLON);
301 res = hid_hw_open(hid);
303 goto bail_normal_power;
305 mutex_unlock(&hiddev->existancelock);
308 hid_hw_power(hid, PM_HINT_NORMAL);
310 mutex_unlock(&hiddev->existancelock);
312 spin_lock_irq(&list->hiddev->list_lock);
313 list_del(&list->node);
314 spin_unlock_irq(&list->hiddev->list_lock);
316 file->private_data = NULL;
324 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
332 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
335 struct hiddev_list *list = file->private_data;
339 event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
340 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
342 if (count < event_size)
345 /* lock against other threads */
346 retval = mutex_lock_interruptible(&list->thread_lock);
350 while (retval == 0) {
351 if (list->head == list->tail) {
352 prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
354 while (list->head == list->tail) {
355 if (signal_pending(current)) {
356 retval = -ERESTARTSYS;
359 if (!list->hiddev->exist) {
363 if (file->f_flags & O_NONBLOCK) {
368 /* let O_NONBLOCK tasks run */
369 mutex_unlock(&list->thread_lock);
371 if (mutex_lock_interruptible(&list->thread_lock)) {
372 finish_wait(&list->hiddev->wait, &wait);
375 set_current_state(TASK_INTERRUPTIBLE);
377 finish_wait(&list->hiddev->wait, &wait);
382 mutex_unlock(&list->thread_lock);
387 while (list->head != list->tail &&
388 retval + event_size <= count) {
389 if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
390 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
391 struct hiddev_event event;
393 event.hid = list->buffer[list->tail].usage_code;
394 event.value = list->buffer[list->tail].value;
395 if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
396 mutex_unlock(&list->thread_lock);
399 retval += sizeof(struct hiddev_event);
402 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
403 (list->flags & HIDDEV_FLAG_REPORT) != 0) {
405 if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
406 mutex_unlock(&list->thread_lock);
409 retval += sizeof(struct hiddev_usage_ref);
412 list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
416 mutex_unlock(&list->thread_lock);
423 * No kernel lock - fine
425 static __poll_t hiddev_poll(struct file *file, poll_table *wait)
427 struct hiddev_list *list = file->private_data;
429 poll_wait(file, &list->hiddev->wait, wait);
430 if (list->head != list->tail)
431 return EPOLLIN | EPOLLRDNORM | EPOLLOUT;
432 if (!list->hiddev->exist)
433 return EPOLLERR | EPOLLHUP;
440 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
442 struct hid_device *hid = hiddev->hid;
443 struct hiddev_report_info rinfo;
444 struct hiddev_usage_ref_multi *uref_multi = NULL;
445 struct hiddev_usage_ref *uref;
446 struct hid_report *report;
447 struct hid_field *field;
450 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
453 uref = &uref_multi->uref;
454 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
455 if (copy_from_user(uref_multi, user_arg,
456 sizeof(*uref_multi)))
459 if (copy_from_user(uref, user_arg, sizeof(*uref)))
465 rinfo.report_type = uref->report_type;
466 rinfo.report_id = uref->report_id;
467 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
470 if (uref->field_index >= report->maxfield)
472 uref->field_index = array_index_nospec(uref->field_index,
475 field = report->field[uref->field_index];
476 if (uref->usage_index >= field->maxusage)
478 uref->usage_index = array_index_nospec(uref->usage_index,
481 uref->usage_code = field->usage[uref->usage_index].hid;
483 if (copy_to_user(user_arg, uref, sizeof(*uref)))
489 if (cmd != HIDIOCGUSAGE &&
490 cmd != HIDIOCGUSAGES &&
491 uref->report_type == HID_REPORT_TYPE_INPUT)
494 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
495 field = hiddev_lookup_usage(hid, uref);
499 rinfo.report_type = uref->report_type;
500 rinfo.report_id = uref->report_id;
501 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
504 if (uref->field_index >= report->maxfield)
506 uref->field_index = array_index_nospec(uref->field_index,
509 field = report->field[uref->field_index];
511 if (cmd == HIDIOCGCOLLECTIONINDEX) {
512 if (uref->usage_index >= field->maxusage)
515 array_index_nospec(uref->usage_index,
517 } else if (uref->usage_index >= field->report_count)
521 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
522 if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
523 uref->usage_index + uref_multi->num_values >
528 array_index_nospec(uref->usage_index,
529 field->report_count -
530 uref_multi->num_values);
535 uref->value = field->value[uref->usage_index];
536 if (copy_to_user(user_arg, uref, sizeof(*uref)))
541 field->value[uref->usage_index] = uref->value;
544 case HIDIOCGCOLLECTIONINDEX:
545 i = field->usage[uref->usage_index].collection_index;
549 for (i = 0; i < uref_multi->num_values; i++)
550 uref_multi->values[i] =
551 field->value[uref->usage_index + i];
552 if (copy_to_user(user_arg, uref_multi,
553 sizeof(*uref_multi)))
557 for (i = 0; i < uref_multi->num_values; i++)
558 field->value[uref->usage_index + i] =
559 uref_multi->values[i];
575 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
577 struct hid_device *hid = hiddev->hid;
578 struct usb_device *dev = hid_to_usb_dev(hid);
582 if (get_user(idx, (int __user *)user_arg))
585 if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
588 if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
593 if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
603 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
605 struct hiddev_list *list = file->private_data;
606 struct hiddev *hiddev = list->hiddev;
607 struct hid_device *hid;
608 struct hiddev_collection_info cinfo;
609 struct hiddev_report_info rinfo;
610 struct hiddev_field_info finfo;
611 struct hiddev_devinfo dinfo;
612 struct hid_report *report;
613 struct hid_field *field;
614 void __user *user_arg = (void __user *)arg;
617 /* Called without BKL by compat methods so no BKL taken */
619 mutex_lock(&hiddev->existancelock);
620 if (!hiddev->exist) {
630 r = put_user(HID_VERSION, (int __user *)arg) ?
634 case HIDIOCAPPLICATION:
635 if (arg >= hid->maxapplication)
638 for (i = 0; i < hid->maxcollection; i++)
639 if (hid->collection[i].type ==
640 HID_COLLECTION_APPLICATION && arg-- == 0)
643 if (i < hid->maxcollection)
644 r = hid->collection[i].usage;
649 struct usb_device *dev = hid_to_usb_dev(hid);
650 struct usbhid_device *usbhid = hid->driver_data;
652 memset(&dinfo, 0, sizeof(dinfo));
654 dinfo.bustype = BUS_USB;
655 dinfo.busnum = dev->bus->busnum;
656 dinfo.devnum = dev->devnum;
657 dinfo.ifnum = usbhid->ifnum;
658 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
659 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
660 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
661 dinfo.num_applications = hid->maxapplication;
663 r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
669 r = put_user(list->flags, (int __user *)arg) ?
677 if (get_user(newflags, (int __user *)arg)) {
682 if ((newflags & ~HIDDEV_FLAGS) != 0 ||
683 ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
684 (newflags & HIDDEV_FLAG_UREF) == 0))
687 list->flags = newflags;
694 r = hiddev_ioctl_string(hiddev, cmd, user_arg);
697 case HIDIOCINITREPORT:
698 usbhid_init_reports(hid);
699 hiddev->initialized = true;
704 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
709 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
712 report = hiddev_lookup_report(hid, &rinfo);
716 hid_hw_request(hid, report, HID_REQ_GET_REPORT);
723 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
728 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
731 report = hiddev_lookup_report(hid, &rinfo);
735 hid_hw_request(hid, report, HID_REQ_SET_REPORT);
741 case HIDIOCGREPORTINFO:
742 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
747 report = hiddev_lookup_report(hid, &rinfo);
751 rinfo.num_fields = report->maxfield;
753 r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
757 case HIDIOCGFIELDINFO:
758 if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
763 rinfo.report_type = finfo.report_type;
764 rinfo.report_id = finfo.report_id;
766 report = hiddev_lookup_report(hid, &rinfo);
770 if (finfo.field_index >= report->maxfield)
772 finfo.field_index = array_index_nospec(finfo.field_index,
775 field = report->field[finfo.field_index];
776 memset(&finfo, 0, sizeof(finfo));
777 finfo.report_type = rinfo.report_type;
778 finfo.report_id = rinfo.report_id;
779 finfo.field_index = field->report_count - 1;
780 finfo.maxusage = field->maxusage;
781 finfo.flags = field->flags;
782 finfo.physical = field->physical;
783 finfo.logical = field->logical;
784 finfo.application = field->application;
785 finfo.logical_minimum = field->logical_minimum;
786 finfo.logical_maximum = field->logical_maximum;
787 finfo.physical_minimum = field->physical_minimum;
788 finfo.physical_maximum = field->physical_maximum;
789 finfo.unit_exponent = field->unit_exponent;
790 finfo.unit = field->unit;
792 r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
802 case HIDIOCGCOLLECTIONINDEX:
803 if (!hiddev->initialized) {
804 usbhid_init_reports(hid);
805 hiddev->initialized = true;
807 r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
810 case HIDIOCGCOLLECTIONINFO:
811 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
816 if (cinfo.index >= hid->maxcollection)
818 cinfo.index = array_index_nospec(cinfo.index,
821 cinfo.type = hid->collection[cinfo.index].type;
822 cinfo.usage = hid->collection[cinfo.index].usage;
823 cinfo.level = hid->collection[cinfo.index].level;
825 r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
830 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
833 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
834 int len = strlen(hid->name) + 1;
835 if (len > _IOC_SIZE(cmd))
836 len = _IOC_SIZE(cmd);
837 r = copy_to_user(user_arg, hid->name, len) ?
842 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
843 int len = strlen(hid->phys) + 1;
844 if (len > _IOC_SIZE(cmd))
845 len = _IOC_SIZE(cmd);
846 r = copy_to_user(user_arg, hid->phys, len) ?
853 mutex_unlock(&hiddev->existancelock);
858 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
860 return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
864 static const struct file_operations hiddev_fops = {
865 .owner = THIS_MODULE,
867 .write = hiddev_write,
870 .release = hiddev_release,
871 .unlocked_ioctl = hiddev_ioctl,
872 .fasync = hiddev_fasync,
874 .compat_ioctl = hiddev_compat_ioctl,
876 .llseek = noop_llseek,
879 static char *hiddev_devnode(struct device *dev, umode_t *mode)
881 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
884 static struct usb_class_driver hiddev_class = {
886 .devnode = hiddev_devnode,
887 .fops = &hiddev_fops,
888 .minor_base = HIDDEV_MINOR_BASE,
892 * This is where hid.c calls us to connect a hid device to the hiddev driver
894 int hiddev_connect(struct hid_device *hid, unsigned int force)
896 struct hiddev *hiddev;
897 struct usbhid_device *usbhid = hid->driver_data;
902 for (i = 0; i < hid->maxcollection; i++)
903 if (hid->collection[i].type ==
904 HID_COLLECTION_APPLICATION &&
905 !IS_INPUT_APPLICATION(hid->collection[i].usage))
908 if (i == hid->maxcollection)
912 if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
915 init_waitqueue_head(&hiddev->wait);
916 INIT_LIST_HEAD(&hiddev->list);
917 spin_lock_init(&hiddev->list_lock);
918 mutex_init(&hiddev->existancelock);
919 hid->hiddev = hiddev;
922 retval = usb_register_dev(usbhid->intf, &hiddev_class);
924 hid_err(hid, "Not able to get a minor for this device\n");
931 * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
934 hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
936 hiddev->minor = usbhid->intf->minor;
942 * This is where hid.c calls us to disconnect a hiddev device from the
943 * corresponding hid device (usually because the usb device has disconnected)
945 static struct usb_class_driver hiddev_class;
946 void hiddev_disconnect(struct hid_device *hid)
948 struct hiddev *hiddev = hid->hiddev;
949 struct usbhid_device *usbhid = hid->driver_data;
951 usb_deregister_dev(usbhid->intf, &hiddev_class);
953 mutex_lock(&hiddev->existancelock);
957 mutex_unlock(&hiddev->existancelock);
958 hid_hw_close(hiddev->hid);
959 wake_up_interruptible(&hiddev->wait);
961 mutex_unlock(&hiddev->existancelock);