linux/drivers/input/misc/uinput.c
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   1/*
   2 *  User level driver support for input subsystem
   3 *
   4 * Heavily based on evdev.c by Vojtech Pavlik
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 *
  20 * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  21 *
  22 * Changes/Revisions:
  23 *      0.3     09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
  24 *              - updated ff support for the changes in kernel interface
  25 *              - added MODULE_VERSION
  26 *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  27 *              - added force feedback support
  28 *              - added UI_SET_PHYS
  29 *      0.1     20/06/2002
  30 *              - first public version
  31 */
  32#include <linux/poll.h>
  33#include <linux/slab.h>
  34#include <linux/module.h>
  35#include <linux/init.h>
  36#include <linux/smp_lock.h>
  37#include <linux/fs.h>
  38#include <linux/miscdevice.h>
  39#include <linux/uinput.h>
  40
  41static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  42{
  43        struct uinput_device    *udev = input_get_drvdata(dev);
  44
  45        udev->buff[udev->head].type = type;
  46        udev->buff[udev->head].code = code;
  47        udev->buff[udev->head].value = value;
  48        do_gettimeofday(&udev->buff[udev->head].time);
  49        udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  50
  51        wake_up_interruptible(&udev->waitq);
  52
  53        return 0;
  54}
  55
  56static int uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request)
  57{
  58        /* Atomically allocate an ID for the given request. Returns 0 on success. */
  59        int id;
  60        int err = -1;
  61
  62        spin_lock(&udev->requests_lock);
  63
  64        for (id = 0; id < UINPUT_NUM_REQUESTS; id++)
  65                if (!udev->requests[id]) {
  66                        request->id = id;
  67                        udev->requests[id] = request;
  68                        err = 0;
  69                        break;
  70                }
  71
  72        spin_unlock(&udev->requests_lock);
  73        return err;
  74}
  75
  76static struct uinput_request* uinput_request_find(struct uinput_device *udev, int id)
  77{
  78        /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
  79        if (id >= UINPUT_NUM_REQUESTS || id < 0)
  80                return NULL;
  81        return udev->requests[id];
  82}
  83
  84static inline int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request)
  85{
  86        /* Allocate slot. If none are available right away, wait. */
  87        return wait_event_interruptible(udev->requests_waitq,
  88                                        !uinput_request_alloc_id(udev, request));
  89}
  90
  91static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request)
  92{
  93        /* Mark slot as available */
  94        udev->requests[request->id] = NULL;
  95        wake_up(&udev->requests_waitq);
  96
  97        complete(&request->done);
  98}
  99
 100static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 101{
 102        /* Tell our userspace app about this new request by queueing an input event */
 103        uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 104
 105        /* Wait for the request to complete */
 106        wait_for_completion(&request->done);
 107        return request->retval;
 108}
 109
 110static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 111{
 112        uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 113}
 114
 115static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 116{
 117        uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 118}
 119
 120static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
 121{
 122        return uinput_dev_event(dev, EV_FF, effect_id, value);
 123}
 124
 125static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
 126{
 127        struct uinput_request request;
 128        int retval;
 129
 130        request.id = -1;
 131        init_completion(&request.done);
 132        request.code = UI_FF_UPLOAD;
 133        request.u.upload.effect = effect;
 134        request.u.upload.old = old;
 135
 136        retval = uinput_request_reserve_slot(input_get_drvdata(dev), &request);
 137        if (!retval)
 138                retval = uinput_request_submit(dev, &request);
 139
 140        return retval;
 141}
 142
 143static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 144{
 145        struct uinput_request request;
 146        int retval;
 147
 148        if (!test_bit(EV_FF, dev->evbit))
 149                return -ENOSYS;
 150
 151        request.id = -1;
 152        init_completion(&request.done);
 153        request.code = UI_FF_ERASE;
 154        request.u.effect_id = effect_id;
 155
 156        retval = uinput_request_reserve_slot(input_get_drvdata(dev), &request);
 157        if (!retval)
 158                retval = uinput_request_submit(dev, &request);
 159
 160        return retval;
 161}
 162
 163static void uinput_destroy_device(struct uinput_device *udev)
 164{
 165        const char *name, *phys;
 166
 167        if (udev->dev) {
 168                name = udev->dev->name;
 169                phys = udev->dev->phys;
 170                if (udev->state == UIST_CREATED)
 171                        input_unregister_device(udev->dev);
 172                else
 173                        input_free_device(udev->dev);
 174                kfree(name);
 175                kfree(phys);
 176                udev->dev = NULL;
 177        }
 178
 179        udev->state = UIST_NEW_DEVICE;
 180}
 181
 182static int uinput_create_device(struct uinput_device *udev)
 183{
 184        struct input_dev *dev = udev->dev;
 185        int error;
 186
 187        if (udev->state != UIST_SETUP_COMPLETE) {
 188                printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 189                return -EINVAL;
 190        }
 191
 192        if (udev->ff_effects_max) {
 193                error = input_ff_create(dev, udev->ff_effects_max);
 194                if (error)
 195                        goto fail1;
 196
 197                dev->ff->upload = uinput_dev_upload_effect;
 198                dev->ff->erase = uinput_dev_erase_effect;
 199                dev->ff->playback = uinput_dev_playback;
 200                dev->ff->set_gain = uinput_dev_set_gain;
 201                dev->ff->set_autocenter = uinput_dev_set_autocenter;
 202        }
 203
 204        error = input_register_device(udev->dev);
 205        if (error)
 206                goto fail2;
 207
 208        udev->state = UIST_CREATED;
 209
 210        return 0;
 211
 212 fail2: input_ff_destroy(dev);
 213 fail1: uinput_destroy_device(udev);
 214        return error;
 215}
 216
 217static int uinput_open(struct inode *inode, struct file *file)
 218{
 219        struct uinput_device *newdev;
 220
 221        newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 222        if (!newdev)
 223                return -ENOMEM;
 224
 225        mutex_init(&newdev->mutex);
 226        spin_lock_init(&newdev->requests_lock);
 227        init_waitqueue_head(&newdev->requests_waitq);
 228        init_waitqueue_head(&newdev->waitq);
 229        newdev->state = UIST_NEW_DEVICE;
 230
 231        file->private_data = newdev;
 232
 233        return 0;
 234}
 235
 236static int uinput_validate_absbits(struct input_dev *dev)
 237{
 238        unsigned int cnt;
 239        int retval = 0;
 240
 241        for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 242                if (!test_bit(cnt, dev->absbit))
 243                        continue;
 244
 245                if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 246                        printk(KERN_DEBUG
 247                                "%s: invalid abs[%02x] min:%d max:%d\n",
 248                                UINPUT_NAME, cnt,
 249                                dev->absmin[cnt], dev->absmax[cnt]);
 250                        retval = -EINVAL;
 251                        break;
 252                }
 253
 254                if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 255                        printk(KERN_DEBUG
 256                                "%s: absflat[%02x] out of range: %d "
 257                                "(min:%d/max:%d)\n",
 258                                UINPUT_NAME, cnt, dev->absflat[cnt],
 259                                dev->absmin[cnt], dev->absmax[cnt]);
 260                        retval = -EINVAL;
 261                        break;
 262                }
 263        }
 264        return retval;
 265}
 266
 267static int uinput_allocate_device(struct uinput_device *udev)
 268{
 269        udev->dev = input_allocate_device();
 270        if (!udev->dev)
 271                return -ENOMEM;
 272
 273        udev->dev->event = uinput_dev_event;
 274        input_set_drvdata(udev->dev, udev);
 275
 276        return 0;
 277}
 278
 279static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 280{
 281        struct uinput_user_dev  *user_dev;
 282        struct input_dev        *dev;
 283        char                    *name;
 284        int                     size;
 285        int                     retval;
 286
 287        if (count != sizeof(struct uinput_user_dev))
 288                return -EINVAL;
 289
 290        if (!udev->dev) {
 291                retval = uinput_allocate_device(udev);
 292                if (retval)
 293                        return retval;
 294        }
 295
 296        dev = udev->dev;
 297
 298        user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 299        if (!user_dev)
 300                return -ENOMEM;
 301
 302        if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 303                retval = -EFAULT;
 304                goto exit;
 305        }
 306
 307        udev->ff_effects_max = user_dev->ff_effects_max;
 308
 309        size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 310        if (!size) {
 311                retval = -EINVAL;
 312                goto exit;
 313        }
 314
 315        kfree(dev->name);
 316        dev->name = name = kmalloc(size, GFP_KERNEL);
 317        if (!name) {
 318                retval = -ENOMEM;
 319                goto exit;
 320        }
 321        strlcpy(name, user_dev->name, size);
 322
 323        dev->id.bustype = user_dev->id.bustype;
 324        dev->id.vendor  = user_dev->id.vendor;
 325        dev->id.product = user_dev->id.product;
 326        dev->id.version = user_dev->id.version;
 327
 328        size = sizeof(int) * (ABS_MAX + 1);
 329        memcpy(dev->absmax, user_dev->absmax, size);
 330        memcpy(dev->absmin, user_dev->absmin, size);
 331        memcpy(dev->absfuzz, user_dev->absfuzz, size);
 332        memcpy(dev->absflat, user_dev->absflat, size);
 333
 334        /* check if absmin/absmax/absfuzz/absflat are filled as
 335         * told in Documentation/input/input-programming.txt */
 336        if (test_bit(EV_ABS, dev->evbit)) {
 337                retval = uinput_validate_absbits(dev);
 338                if (retval < 0)
 339                        goto exit;
 340        }
 341
 342        udev->state = UIST_SETUP_COMPLETE;
 343        retval = count;
 344
 345 exit:
 346        kfree(user_dev);
 347        return retval;
 348}
 349
 350static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 351{
 352        struct input_event ev;
 353
 354        if (count != sizeof(struct input_event))
 355                return -EINVAL;
 356
 357        if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 358                return -EFAULT;
 359
 360        input_event(udev->dev, ev.type, ev.code, ev.value);
 361
 362        return sizeof(struct input_event);
 363}
 364
 365static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 366{
 367        struct uinput_device *udev = file->private_data;
 368        int retval;
 369
 370        retval = mutex_lock_interruptible(&udev->mutex);
 371        if (retval)
 372                return retval;
 373
 374        retval = udev->state == UIST_CREATED ?
 375                        uinput_inject_event(udev, buffer, count) :
 376                        uinput_setup_device(udev, buffer, count);
 377
 378        mutex_unlock(&udev->mutex);
 379
 380        return retval;
 381}
 382
 383static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 384{
 385        struct uinput_device *udev = file->private_data;
 386        int retval = 0;
 387
 388        if (udev->state != UIST_CREATED)
 389                return -ENODEV;
 390
 391        if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 392                return -EAGAIN;
 393
 394        retval = wait_event_interruptible(udev->waitq,
 395                        udev->head != udev->tail || udev->state != UIST_CREATED);
 396        if (retval)
 397                return retval;
 398
 399        retval = mutex_lock_interruptible(&udev->mutex);
 400        if (retval)
 401                return retval;
 402
 403        if (udev->state != UIST_CREATED) {
 404                retval = -ENODEV;
 405                goto out;
 406        }
 407
 408        while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 409                if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 410                        retval = -EFAULT;
 411                        goto out;
 412                }
 413                udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 414                retval += sizeof(struct input_event);
 415        }
 416
 417 out:
 418        mutex_unlock(&udev->mutex);
 419
 420        return retval;
 421}
 422
 423static unsigned int uinput_poll(struct file *file, poll_table *wait)
 424{
 425        struct uinput_device *udev = file->private_data;
 426
 427        poll_wait(file, &udev->waitq, wait);
 428
 429        if (udev->head != udev->tail)
 430                return POLLIN | POLLRDNORM;
 431
 432        return 0;
 433}
 434
 435static int uinput_release(struct inode *inode, struct file *file)
 436{
 437        struct uinput_device *udev = file->private_data;
 438
 439        uinput_destroy_device(udev);
 440        kfree(udev);
 441
 442        return 0;
 443}
 444
 445#define uinput_set_bit(_arg, _bit, _max)                \
 446({                                                      \
 447        int __ret = 0;                                  \
 448        if (udev->state == UIST_CREATED)                \
 449                __ret =  -EINVAL;                       \
 450        else if ((_arg) > (_max))                       \
 451                __ret = -EINVAL;                        \
 452        else set_bit((_arg), udev->dev->_bit);          \
 453        __ret;                                          \
 454})
 455
 456static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 457{
 458        int                     retval;
 459        struct uinput_device    *udev;
 460        void __user             *p = (void __user *)arg;
 461        struct uinput_ff_upload ff_up;
 462        struct uinput_ff_erase  ff_erase;
 463        struct uinput_request   *req;
 464        int                     length;
 465        char                    *phys;
 466
 467        udev = file->private_data;
 468
 469        retval = mutex_lock_interruptible(&udev->mutex);
 470        if (retval)
 471                return retval;
 472
 473        if (!udev->dev) {
 474                retval = uinput_allocate_device(udev);
 475                if (retval)
 476                        goto out;
 477        }
 478
 479        switch (cmd) {
 480                case UI_DEV_CREATE:
 481                        retval = uinput_create_device(udev);
 482                        break;
 483
 484                case UI_DEV_DESTROY:
 485                        uinput_destroy_device(udev);
 486                        break;
 487
 488                case UI_SET_EVBIT:
 489                        retval = uinput_set_bit(arg, evbit, EV_MAX);
 490                        break;
 491
 492                case UI_SET_KEYBIT:
 493                        retval = uinput_set_bit(arg, keybit, KEY_MAX);
 494                        break;
 495
 496                case UI_SET_RELBIT:
 497                        retval = uinput_set_bit(arg, relbit, REL_MAX);
 498                        break;
 499
 500                case UI_SET_ABSBIT:
 501                        retval = uinput_set_bit(arg, absbit, ABS_MAX);
 502                        break;
 503
 504                case UI_SET_MSCBIT:
 505                        retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 506                        break;
 507
 508                case UI_SET_LEDBIT:
 509                        retval = uinput_set_bit(arg, ledbit, LED_MAX);
 510                        break;
 511
 512                case UI_SET_SNDBIT:
 513                        retval = uinput_set_bit(arg, sndbit, SND_MAX);
 514                        break;
 515
 516                case UI_SET_FFBIT:
 517                        retval = uinput_set_bit(arg, ffbit, FF_MAX);
 518                        break;
 519
 520                case UI_SET_SWBIT:
 521                        retval = uinput_set_bit(arg, swbit, SW_MAX);
 522                        break;
 523
 524                case UI_SET_PHYS:
 525                        if (udev->state == UIST_CREATED) {
 526                                retval = -EINVAL;
 527                                goto out;
 528                        }
 529                        length = strnlen_user(p, 1024);
 530                        if (length <= 0) {
 531                                retval = -EFAULT;
 532                                break;
 533                        }
 534                        kfree(udev->dev->phys);
 535                        udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 536                        if (!phys) {
 537                                retval = -ENOMEM;
 538                                break;
 539                        }
 540                        if (copy_from_user(phys, p, length)) {
 541                                udev->dev->phys = NULL;
 542                                kfree(phys);
 543                                retval = -EFAULT;
 544                                break;
 545                        }
 546                        phys[length - 1] = '\0';
 547                        break;
 548
 549                case UI_BEGIN_FF_UPLOAD:
 550                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 551                                retval = -EFAULT;
 552                                break;
 553                        }
 554                        req = uinput_request_find(udev, ff_up.request_id);
 555                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 556                                retval = -EINVAL;
 557                                break;
 558                        }
 559                        ff_up.retval = 0;
 560                        memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
 561                        if (req->u.upload.old)
 562                                memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
 563                        else
 564                                memset(&ff_up.old, 0, sizeof(struct ff_effect));
 565
 566                        if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 567                                retval = -EFAULT;
 568                                break;
 569                        }
 570                        break;
 571
 572                case UI_BEGIN_FF_ERASE:
 573                        if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 574                                retval = -EFAULT;
 575                                break;
 576                        }
 577                        req = uinput_request_find(udev, ff_erase.request_id);
 578                        if (!(req && req->code == UI_FF_ERASE)) {
 579                                retval = -EINVAL;
 580                                break;
 581                        }
 582                        ff_erase.retval = 0;
 583                        ff_erase.effect_id = req->u.effect_id;
 584                        if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 585                                retval = -EFAULT;
 586                                break;
 587                        }
 588                        break;
 589
 590                case UI_END_FF_UPLOAD:
 591                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 592                                retval = -EFAULT;
 593                                break;
 594                        }
 595                        req = uinput_request_find(udev, ff_up.request_id);
 596                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 597                                retval = -EINVAL;
 598                                break;
 599                        }
 600                        req->retval = ff_up.retval;
 601                        uinput_request_done(udev, req);
 602                        break;
 603
 604                case UI_END_FF_ERASE:
 605                        if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 606                                retval = -EFAULT;
 607                                break;
 608                        }
 609                        req = uinput_request_find(udev, ff_erase.request_id);
 610                        if (!(req && req->code == UI_FF_ERASE)) {
 611                                retval = -EINVAL;
 612                                break;
 613                        }
 614                        req->retval = ff_erase.retval;
 615                        uinput_request_done(udev, req);
 616                        break;
 617
 618                default:
 619                        retval = -EINVAL;
 620        }
 621
 622 out:
 623        mutex_unlock(&udev->mutex);
 624        return retval;
 625}
 626
 627static const struct file_operations uinput_fops = {
 628        .owner          = THIS_MODULE,
 629        .open           = uinput_open,
 630        .release        = uinput_release,
 631        .read           = uinput_read,
 632        .write          = uinput_write,
 633        .poll           = uinput_poll,
 634        .unlocked_ioctl = uinput_ioctl,
 635};
 636
 637static struct miscdevice uinput_misc = {
 638        .fops           = &uinput_fops,
 639        .minor          = UINPUT_MINOR,
 640        .name           = UINPUT_NAME,
 641};
 642
 643static int __init uinput_init(void)
 644{
 645        return misc_register(&uinput_misc);
 646}
 647
 648static void __exit uinput_exit(void)
 649{
 650        misc_deregister(&uinput_misc);
 651}
 652
 653MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 654MODULE_DESCRIPTION("User level driver support for input subsystem");
 655MODULE_LICENSE("GPL");
 656MODULE_VERSION("0.3");
 657
 658module_init(uinput_init);
 659module_exit(uinput_exit);
 660
 661