linux/drivers/hid/usbhid/hiddev.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Copyright (c) 2001 Paul Stewart
   4 *  Copyright (c) 2001 Vojtech Pavlik
   5 *
   6 *  HID char devices, giving access to raw HID device events.
   7 */
   8
   9/*
  10 *
  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>
  13 */
  14
  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>
  27#include "usbhid.h"
  28
  29#ifdef CONFIG_USB_DYNAMIC_MINORS
  30#define HIDDEV_MINOR_BASE       0
  31#define HIDDEV_MINORS           256
  32#else
  33#define HIDDEV_MINOR_BASE       96
  34#define HIDDEV_MINORS           16
  35#endif
  36#define HIDDEV_BUFFER_SIZE      2048
  37
  38struct hiddev_list {
  39        struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  40        int head;
  41        int tail;
  42        unsigned flags;
  43        struct fasync_struct *fasync;
  44        struct hiddev *hiddev;
  45        struct list_head node;
  46        struct mutex thread_lock;
  47};
  48
  49/*
  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.
  54 */
  55static struct hid_report *
  56hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  57{
  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;
  63
  64        if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  65            rinfo->report_type > HID_REPORT_TYPE_MAX)
  66                return NULL;
  67
  68        report_enum = hid->report_enum +
  69                (rinfo->report_type - HID_REPORT_TYPE_MIN);
  70
  71        switch (flags) {
  72        case 0: /* Nothing to do -- report_id is already set correctly */
  73                break;
  74
  75        case HID_REPORT_ID_FIRST:
  76                if (list_empty(&report_enum->report_list))
  77                        return NULL;
  78
  79                list = report_enum->report_list.next;
  80                report = list_entry(list, struct hid_report, list);
  81                rinfo->report_id = report->id;
  82                break;
  83
  84        case HID_REPORT_ID_NEXT:
  85                report = report_enum->report_id_hash[rid];
  86                if (!report)
  87                        return NULL;
  88
  89                list = report->list.next;
  90                if (list == &report_enum->report_list)
  91                        return NULL;
  92
  93                report = list_entry(list, struct hid_report, list);
  94                rinfo->report_id = report->id;
  95                break;
  96
  97        default:
  98                return NULL;
  99        }
 100
 101        return report_enum->report_id_hash[rinfo->report_id];
 102}
 103
 104/*
 105 * Perform an exhaustive search of the report table for a usage, given its
 106 * type and usage id.
 107 */
 108static struct hid_field *
 109hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 110{
 111        int i, j;
 112        struct hid_report *report;
 113        struct hid_report_enum *report_enum;
 114        struct hid_field *field;
 115
 116        if (uref->report_type < HID_REPORT_TYPE_MIN ||
 117            uref->report_type > HID_REPORT_TYPE_MAX)
 118                return NULL;
 119
 120        report_enum = hid->report_enum +
 121                (uref->report_type - HID_REPORT_TYPE_MIN);
 122
 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;
 131                                        return field;
 132                                }
 133                        }
 134                }
 135        }
 136
 137        return NULL;
 138}
 139
 140static void hiddev_send_event(struct hid_device *hid,
 141                              struct hiddev_usage_ref *uref)
 142{
 143        struct hiddev *hiddev = hid->hiddev;
 144        struct hiddev_list *list;
 145        unsigned long flags;
 146
 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);
 155                }
 156        }
 157        spin_unlock_irqrestore(&hiddev->list_lock, flags);
 158
 159        wake_up_interruptible(&hiddev->wait);
 160}
 161
 162/*
 163 * This is where hid.c calls into hiddev to pass an event that occurred over
 164 * the interrupt pipe
 165 */
 166void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 167                      struct hid_usage *usage, __s32 value)
 168{
 169        unsigned type = field->report_type;
 170        struct hiddev_usage_ref uref;
 171
 172        uref.report_type =
 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;
 180        uref.value = value;
 181
 182        hiddev_send_event(hid, &uref);
 183}
 184EXPORT_SYMBOL_GPL(hiddev_hid_event);
 185
 186void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 187{
 188        unsigned type = report->type;
 189        struct hiddev_usage_ref uref;
 190
 191        memset(&uref, 0, sizeof(uref));
 192        uref.report_type =
 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;
 198
 199        hiddev_send_event(hid, &uref);
 200}
 201
 202/*
 203 * fasync file op
 204 */
 205static int hiddev_fasync(int fd, struct file *file, int on)
 206{
 207        struct hiddev_list *list = file->private_data;
 208
 209        return fasync_helper(fd, file, on, &list->fasync);
 210}
 211
 212
 213/*
 214 * release file op
 215 */
 216static int hiddev_release(struct inode * inode, struct file * file)
 217{
 218        struct hiddev_list *list = file->private_data;
 219        unsigned long flags;
 220
 221        spin_lock_irqsave(&list->hiddev->list_lock, flags);
 222        list_del(&list->node);
 223        spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 224
 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);
 230                } else {
 231                        mutex_unlock(&list->hiddev->existancelock);
 232                        kfree(list->hiddev);
 233                        vfree(list);
 234                        return 0;
 235                }
 236        }
 237
 238        mutex_unlock(&list->hiddev->existancelock);
 239        vfree(list);
 240
 241        return 0;
 242}
 243
 244static int __hiddev_open(struct hiddev *hiddev, struct file *file)
 245{
 246        struct hiddev_list *list;
 247        int error;
 248
 249        lockdep_assert_held(&hiddev->existancelock);
 250
 251        list = vzalloc(sizeof(*list));
 252        if (!list)
 253                return -ENOMEM;
 254
 255        mutex_init(&list->thread_lock);
 256        list->hiddev = hiddev;
 257
 258        if (!hiddev->open++) {
 259                error = hid_hw_power(hiddev->hid, PM_HINT_FULLON);
 260                if (error < 0)
 261                        goto err_drop_count;
 262
 263                error = hid_hw_open(hiddev->hid);
 264                if (error < 0)
 265                        goto err_normal_power;
 266        }
 267
 268        spin_lock_irq(&hiddev->list_lock);
 269        list_add_tail(&list->node, &hiddev->list);
 270        spin_unlock_irq(&hiddev->list_lock);
 271
 272        file->private_data = list;
 273
 274        return 0;
 275
 276err_normal_power:
 277        hid_hw_power(hiddev->hid, PM_HINT_NORMAL);
 278err_drop_count:
 279        hiddev->open--;
 280        vfree(list);
 281        return error;
 282}
 283
 284/*
 285 * open file op
 286 */
 287static int hiddev_open(struct inode *inode, struct file *file)
 288{
 289        struct usb_interface *intf;
 290        struct hid_device *hid;
 291        struct hiddev *hiddev;
 292        int res;
 293
 294        intf = usbhid_find_interface(iminor(inode));
 295        if (!intf)
 296                return -ENODEV;
 297
 298        hid = usb_get_intfdata(intf);
 299        hiddev = hid->hiddev;
 300
 301        mutex_lock(&hiddev->existancelock);
 302        res = hiddev->exist ? __hiddev_open(hiddev, file) : -ENODEV;
 303        mutex_unlock(&hiddev->existancelock);
 304
 305        return res;
 306}
 307
 308/*
 309 * "write" file op
 310 */
 311static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 312{
 313        return -EINVAL;
 314}
 315
 316/*
 317 * "read" file op
 318 */
 319static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 320{
 321        DEFINE_WAIT(wait);
 322        struct hiddev_list *list = file->private_data;
 323        int event_size;
 324        int retval;
 325
 326        event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 327                sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 328
 329        if (count < event_size)
 330                return 0;
 331
 332        /* lock against other threads */
 333        retval = mutex_lock_interruptible(&list->thread_lock);
 334        if (retval)
 335                return -ERESTARTSYS;
 336
 337        while (retval == 0) {
 338                if (list->head == list->tail) {
 339                        prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
 340
 341                        while (list->head == list->tail) {
 342                                if (signal_pending(current)) {
 343                                        retval = -ERESTARTSYS;
 344                                        break;
 345                                }
 346                                if (!list->hiddev->exist) {
 347                                        retval = -EIO;
 348                                        break;
 349                                }
 350                                if (file->f_flags & O_NONBLOCK) {
 351                                        retval = -EAGAIN;
 352                                        break;
 353                                }
 354
 355                                /* let O_NONBLOCK tasks run */
 356                                mutex_unlock(&list->thread_lock);
 357                                schedule();
 358                                if (mutex_lock_interruptible(&list->thread_lock)) {
 359                                        finish_wait(&list->hiddev->wait, &wait);
 360                                        return -EINTR;
 361                                }
 362                                set_current_state(TASK_INTERRUPTIBLE);
 363                        }
 364                        finish_wait(&list->hiddev->wait, &wait);
 365
 366                }
 367
 368                if (retval) {
 369                        mutex_unlock(&list->thread_lock);
 370                        return retval;
 371                }
 372
 373
 374                while (list->head != list->tail &&
 375                       retval + event_size <= count) {
 376                        if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 377                                if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
 378                                        struct hiddev_event event;
 379
 380                                        event.hid = list->buffer[list->tail].usage_code;
 381                                        event.value = list->buffer[list->tail].value;
 382                                        if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
 383                                                mutex_unlock(&list->thread_lock);
 384                                                return -EFAULT;
 385                                        }
 386                                        retval += sizeof(struct hiddev_event);
 387                                }
 388                        } else {
 389                                if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 390                                    (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 391
 392                                        if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
 393                                                mutex_unlock(&list->thread_lock);
 394                                                return -EFAULT;
 395                                        }
 396                                        retval += sizeof(struct hiddev_usage_ref);
 397                                }
 398                        }
 399                        list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 400                }
 401
 402        }
 403        mutex_unlock(&list->thread_lock);
 404
 405        return retval;
 406}
 407
 408/*
 409 * "poll" file op
 410 * No kernel lock - fine
 411 */
 412static __poll_t hiddev_poll(struct file *file, poll_table *wait)
 413{
 414        struct hiddev_list *list = file->private_data;
 415
 416        poll_wait(file, &list->hiddev->wait, wait);
 417        if (list->head != list->tail)
 418                return EPOLLIN | EPOLLRDNORM | EPOLLOUT;
 419        if (!list->hiddev->exist)
 420                return EPOLLERR | EPOLLHUP;
 421        return 0;
 422}
 423
 424/*
 425 * "ioctl" file op
 426 */
 427static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 428{
 429        struct hid_device *hid = hiddev->hid;
 430        struct hiddev_report_info rinfo;
 431        struct hiddev_usage_ref_multi *uref_multi = NULL;
 432        struct hiddev_usage_ref *uref;
 433        struct hid_report *report;
 434        struct hid_field *field;
 435        int i;
 436
 437        uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 438        if (!uref_multi)
 439                return -ENOMEM;
 440        uref = &uref_multi->uref;
 441        if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 442                if (copy_from_user(uref_multi, user_arg,
 443                                   sizeof(*uref_multi)))
 444                        goto fault;
 445        } else {
 446                if (copy_from_user(uref, user_arg, sizeof(*uref)))
 447                        goto fault;
 448        }
 449
 450        switch (cmd) {
 451        case HIDIOCGUCODE:
 452                rinfo.report_type = uref->report_type;
 453                rinfo.report_id = uref->report_id;
 454                if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 455                        goto inval;
 456
 457                if (uref->field_index >= report->maxfield)
 458                        goto inval;
 459                uref->field_index = array_index_nospec(uref->field_index,
 460                                                       report->maxfield);
 461
 462                field = report->field[uref->field_index];
 463                if (uref->usage_index >= field->maxusage)
 464                        goto inval;
 465                uref->usage_index = array_index_nospec(uref->usage_index,
 466                                                       field->maxusage);
 467
 468                uref->usage_code = field->usage[uref->usage_index].hid;
 469
 470                if (copy_to_user(user_arg, uref, sizeof(*uref)))
 471                        goto fault;
 472
 473                goto goodreturn;
 474
 475        default:
 476                if (cmd != HIDIOCGUSAGE &&
 477                    cmd != HIDIOCGUSAGES &&
 478                    uref->report_type == HID_REPORT_TYPE_INPUT)
 479                        goto inval;
 480
 481                if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 482                        field = hiddev_lookup_usage(hid, uref);
 483                        if (field == NULL)
 484                                goto inval;
 485                } else {
 486                        rinfo.report_type = uref->report_type;
 487                        rinfo.report_id = uref->report_id;
 488                        if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 489                                goto inval;
 490
 491                        if (uref->field_index >= report->maxfield)
 492                                goto inval;
 493                        uref->field_index = array_index_nospec(uref->field_index,
 494                                                               report->maxfield);
 495
 496                        field = report->field[uref->field_index];
 497
 498                        if (cmd == HIDIOCGCOLLECTIONINDEX) {
 499                                if (uref->usage_index >= field->maxusage)
 500                                        goto inval;
 501                                uref->usage_index =
 502                                        array_index_nospec(uref->usage_index,
 503                                                           field->maxusage);
 504                        } else if (uref->usage_index >= field->report_count)
 505                                goto inval;
 506                }
 507
 508                if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 509                        if (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 510                            uref->usage_index + uref_multi->num_values >
 511                            field->report_count)
 512                                goto inval;
 513
 514                        uref->usage_index =
 515                                array_index_nospec(uref->usage_index,
 516                                                   field->report_count -
 517                                                   uref_multi->num_values);
 518                }
 519
 520                switch (cmd) {
 521                case HIDIOCGUSAGE:
 522                        if (uref->usage_index >= field->report_count)
 523                                goto inval;
 524                        uref->value = field->value[uref->usage_index];
 525                        if (copy_to_user(user_arg, uref, sizeof(*uref)))
 526                                goto fault;
 527                        goto goodreturn;
 528
 529                case HIDIOCSUSAGE:
 530                        if (uref->usage_index >= field->report_count)
 531                                goto inval;
 532                        field->value[uref->usage_index] = uref->value;
 533                        goto goodreturn;
 534
 535                case HIDIOCGCOLLECTIONINDEX:
 536                        i = field->usage[uref->usage_index].collection_index;
 537                        kfree(uref_multi);
 538                        return i;
 539                case HIDIOCGUSAGES:
 540                        for (i = 0; i < uref_multi->num_values; i++)
 541                                uref_multi->values[i] =
 542                                    field->value[uref->usage_index + i];
 543                        if (copy_to_user(user_arg, uref_multi,
 544                                         sizeof(*uref_multi)))
 545                                goto fault;
 546                        goto goodreturn;
 547                case HIDIOCSUSAGES:
 548                        for (i = 0; i < uref_multi->num_values; i++)
 549                                field->value[uref->usage_index + i] =
 550                                    uref_multi->values[i];
 551                        goto goodreturn;
 552                }
 553
 554goodreturn:
 555                kfree(uref_multi);
 556                return 0;
 557fault:
 558                kfree(uref_multi);
 559                return -EFAULT;
 560inval:
 561                kfree(uref_multi);
 562                return -EINVAL;
 563        }
 564}
 565
 566static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 567{
 568        struct hid_device *hid = hiddev->hid;
 569        struct usb_device *dev = hid_to_usb_dev(hid);
 570        int idx, len;
 571        char *buf;
 572
 573        if (get_user(idx, (int __user *)user_arg))
 574                return -EFAULT;
 575
 576        if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 577                return -ENOMEM;
 578
 579        if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 580                kfree(buf);
 581                return -EINVAL;
 582        }
 583
 584        if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 585                kfree(buf);
 586                return -EFAULT;
 587        }
 588
 589        kfree(buf);
 590
 591        return len;
 592}
 593
 594static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 595{
 596        struct hiddev_list *list = file->private_data;
 597        struct hiddev *hiddev = list->hiddev;
 598        struct hid_device *hid;
 599        struct hiddev_collection_info cinfo;
 600        struct hiddev_report_info rinfo;
 601        struct hiddev_field_info finfo;
 602        struct hiddev_devinfo dinfo;
 603        struct hid_report *report;
 604        struct hid_field *field;
 605        void __user *user_arg = (void __user *)arg;
 606        int i, r = -EINVAL;
 607
 608        /* Called without BKL by compat methods so no BKL taken */
 609
 610        mutex_lock(&hiddev->existancelock);
 611        if (!hiddev->exist) {
 612                r = -ENODEV;
 613                goto ret_unlock;
 614        }
 615
 616        hid = hiddev->hid;
 617
 618        switch (cmd) {
 619
 620        case HIDIOCGVERSION:
 621                r = put_user(HID_VERSION, (int __user *)arg) ?
 622                        -EFAULT : 0;
 623                break;
 624
 625        case HIDIOCAPPLICATION:
 626                if (arg >= hid->maxapplication)
 627                        break;
 628
 629                for (i = 0; i < hid->maxcollection; i++)
 630                        if (hid->collection[i].type ==
 631                            HID_COLLECTION_APPLICATION && arg-- == 0)
 632                                break;
 633
 634                if (i < hid->maxcollection)
 635                        r = hid->collection[i].usage;
 636                break;
 637
 638        case HIDIOCGDEVINFO:
 639                {
 640                        struct usb_device *dev = hid_to_usb_dev(hid);
 641                        struct usbhid_device *usbhid = hid->driver_data;
 642
 643                        memset(&dinfo, 0, sizeof(dinfo));
 644
 645                        dinfo.bustype = BUS_USB;
 646                        dinfo.busnum = dev->bus->busnum;
 647                        dinfo.devnum = dev->devnum;
 648                        dinfo.ifnum = usbhid->ifnum;
 649                        dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 650                        dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 651                        dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 652                        dinfo.num_applications = hid->maxapplication;
 653
 654                        r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
 655                                -EFAULT : 0;
 656                        break;
 657                }
 658
 659        case HIDIOCGFLAG:
 660                r = put_user(list->flags, (int __user *)arg) ?
 661                        -EFAULT : 0;
 662                break;
 663
 664        case HIDIOCSFLAG:
 665                {
 666                        int newflags;
 667
 668                        if (get_user(newflags, (int __user *)arg)) {
 669                                r = -EFAULT;
 670                                break;
 671                        }
 672
 673                        if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 674                            ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 675                             (newflags & HIDDEV_FLAG_UREF) == 0))
 676                                break;
 677
 678                        list->flags = newflags;
 679
 680                        r = 0;
 681                        break;
 682                }
 683
 684        case HIDIOCGSTRING:
 685                r = hiddev_ioctl_string(hiddev, cmd, user_arg);
 686                break;
 687
 688        case HIDIOCINITREPORT:
 689                usbhid_init_reports(hid);
 690                hiddev->initialized = true;
 691                r = 0;
 692                break;
 693
 694        case HIDIOCGREPORT:
 695                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
 696                        r = -EFAULT;
 697                        break;
 698                }
 699
 700                if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 701                        break;
 702
 703                report = hiddev_lookup_report(hid, &rinfo);
 704                if (report == NULL)
 705                        break;
 706
 707                hid_hw_request(hid, report, HID_REQ_GET_REPORT);
 708                hid_hw_wait(hid);
 709
 710                r = 0;
 711                break;
 712
 713        case HIDIOCSREPORT:
 714                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
 715                        r = -EFAULT;
 716                        break;
 717                }
 718
 719                if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 720                        break;
 721
 722                report = hiddev_lookup_report(hid, &rinfo);
 723                if (report == NULL)
 724                        break;
 725
 726                hid_hw_request(hid, report, HID_REQ_SET_REPORT);
 727                hid_hw_wait(hid);
 728
 729                r = 0;
 730                break;
 731
 732        case HIDIOCGREPORTINFO:
 733                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
 734                        r = -EFAULT;
 735                        break;
 736                }
 737
 738                report = hiddev_lookup_report(hid, &rinfo);
 739                if (report == NULL)
 740                        break;
 741
 742                rinfo.num_fields = report->maxfield;
 743
 744                r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
 745                        -EFAULT : 0;
 746                break;
 747
 748        case HIDIOCGFIELDINFO:
 749                if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
 750                        r = -EFAULT;
 751                        break;
 752                }
 753
 754                rinfo.report_type = finfo.report_type;
 755                rinfo.report_id = finfo.report_id;
 756
 757                report = hiddev_lookup_report(hid, &rinfo);
 758                if (report == NULL)
 759                        break;
 760
 761                if (finfo.field_index >= report->maxfield)
 762                        break;
 763                finfo.field_index = array_index_nospec(finfo.field_index,
 764                                                       report->maxfield);
 765
 766                field = report->field[finfo.field_index];
 767                memset(&finfo, 0, sizeof(finfo));
 768                finfo.report_type = rinfo.report_type;
 769                finfo.report_id = rinfo.report_id;
 770                finfo.field_index = field->report_count - 1;
 771                finfo.maxusage = field->maxusage;
 772                finfo.flags = field->flags;
 773                finfo.physical = field->physical;
 774                finfo.logical = field->logical;
 775                finfo.application = field->application;
 776                finfo.logical_minimum = field->logical_minimum;
 777                finfo.logical_maximum = field->logical_maximum;
 778                finfo.physical_minimum = field->physical_minimum;
 779                finfo.physical_maximum = field->physical_maximum;
 780                finfo.unit_exponent = field->unit_exponent;
 781                finfo.unit = field->unit;
 782
 783                r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
 784                        -EFAULT : 0;
 785                break;
 786
 787        case HIDIOCGUCODE:
 788        case HIDIOCGUSAGE:
 789        case HIDIOCSUSAGE:
 790        case HIDIOCGUSAGES:
 791        case HIDIOCSUSAGES:
 792        case HIDIOCGCOLLECTIONINDEX:
 793                if (!hiddev->initialized) {
 794                        usbhid_init_reports(hid);
 795                        hiddev->initialized = true;
 796                }
 797                r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
 798                break;
 799
 800        case HIDIOCGCOLLECTIONINFO:
 801                if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
 802                        r = -EFAULT;
 803                        break;
 804                }
 805
 806                if (cinfo.index >= hid->maxcollection)
 807                        break;
 808                cinfo.index = array_index_nospec(cinfo.index,
 809                                                 hid->maxcollection);
 810
 811                cinfo.type = hid->collection[cinfo.index].type;
 812                cinfo.usage = hid->collection[cinfo.index].usage;
 813                cinfo.level = hid->collection[cinfo.index].level;
 814
 815                r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
 816                        -EFAULT : 0;
 817                break;
 818
 819        default:
 820                if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 821                        break;
 822
 823                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 824                        int len = strlen(hid->name) + 1;
 825                        if (len > _IOC_SIZE(cmd))
 826                                 len = _IOC_SIZE(cmd);
 827                        r = copy_to_user(user_arg, hid->name, len) ?
 828                                -EFAULT : len;
 829                        break;
 830                }
 831
 832                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 833                        int len = strlen(hid->phys) + 1;
 834                        if (len > _IOC_SIZE(cmd))
 835                                len = _IOC_SIZE(cmd);
 836                        r = copy_to_user(user_arg, hid->phys, len) ?
 837                                -EFAULT : len;
 838                        break;
 839                }
 840        }
 841
 842ret_unlock:
 843        mutex_unlock(&hiddev->existancelock);
 844        return r;
 845}
 846
 847static const struct file_operations hiddev_fops = {
 848        .owner =        THIS_MODULE,
 849        .read =         hiddev_read,
 850        .write =        hiddev_write,
 851        .poll =         hiddev_poll,
 852        .open =         hiddev_open,
 853        .release =      hiddev_release,
 854        .unlocked_ioctl =       hiddev_ioctl,
 855        .fasync =       hiddev_fasync,
 856        .compat_ioctl   = compat_ptr_ioctl,
 857        .llseek         = noop_llseek,
 858};
 859
 860static char *hiddev_devnode(struct device *dev, umode_t *mode)
 861{
 862        return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 863}
 864
 865static struct usb_class_driver hiddev_class = {
 866        .name =         "hiddev%d",
 867        .devnode =      hiddev_devnode,
 868        .fops =         &hiddev_fops,
 869        .minor_base =   HIDDEV_MINOR_BASE,
 870};
 871
 872/*
 873 * This is where hid.c calls us to connect a hid device to the hiddev driver
 874 */
 875int hiddev_connect(struct hid_device *hid, unsigned int force)
 876{
 877        struct hiddev *hiddev;
 878        struct usbhid_device *usbhid = hid->driver_data;
 879        int retval;
 880
 881        if (!force) {
 882                unsigned int i;
 883                for (i = 0; i < hid->maxcollection; i++)
 884                        if (hid->collection[i].type ==
 885                            HID_COLLECTION_APPLICATION &&
 886                            !IS_INPUT_APPLICATION(hid->collection[i].usage))
 887                                break;
 888
 889                if (i == hid->maxcollection)
 890                        return -EINVAL;
 891        }
 892
 893        if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 894                return -ENOMEM;
 895
 896        init_waitqueue_head(&hiddev->wait);
 897        INIT_LIST_HEAD(&hiddev->list);
 898        spin_lock_init(&hiddev->list_lock);
 899        mutex_init(&hiddev->existancelock);
 900        hid->hiddev = hiddev;
 901        hiddev->hid = hid;
 902        hiddev->exist = 1;
 903        retval = usb_register_dev(usbhid->intf, &hiddev_class);
 904        if (retval) {
 905                hid_err(hid, "Not able to get a minor for this device\n");
 906                hid->hiddev = NULL;
 907                kfree(hiddev);
 908                return retval;
 909        }
 910
 911        /*
 912         * If HID_QUIRK_NO_INIT_REPORTS is set, make sure we don't initialize
 913         * the reports.
 914         */
 915        hiddev->initialized = hid->quirks & HID_QUIRK_NO_INIT_REPORTS;
 916
 917        hiddev->minor = usbhid->intf->minor;
 918
 919        return 0;
 920}
 921
 922/*
 923 * This is where hid.c calls us to disconnect a hiddev device from the
 924 * corresponding hid device (usually because the usb device has disconnected)
 925 */
 926static struct usb_class_driver hiddev_class;
 927void hiddev_disconnect(struct hid_device *hid)
 928{
 929        struct hiddev *hiddev = hid->hiddev;
 930        struct usbhid_device *usbhid = hid->driver_data;
 931
 932        usb_deregister_dev(usbhid->intf, &hiddev_class);
 933
 934        mutex_lock(&hiddev->existancelock);
 935        hiddev->exist = 0;
 936
 937        if (hiddev->open) {
 938                hid_hw_close(hiddev->hid);
 939                wake_up_interruptible(&hiddev->wait);
 940                mutex_unlock(&hiddev->existancelock);
 941        } else {
 942                mutex_unlock(&hiddev->existancelock);
 943                kfree(hiddev);
 944        }
 945}
 946