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        lock_kernel();
 226        mutex_init(&newdev->mutex);
 227        spin_lock_init(&newdev->requests_lock);
 228        init_waitqueue_head(&newdev->requests_waitq);
 229        init_waitqueue_head(&newdev->waitq);
 230        newdev->state = UIST_NEW_DEVICE;
 231
 232        file->private_data = newdev;
 233        unlock_kernel();
 234
 235        return 0;
 236}
 237
 238static int uinput_validate_absbits(struct input_dev *dev)
 239{
 240        unsigned int cnt;
 241        int retval = 0;
 242
 243        for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 244                if (!test_bit(cnt, dev->absbit))
 245                        continue;
 246
 247                if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 248                        printk(KERN_DEBUG
 249                                "%s: invalid abs[%02x] min:%d max:%d\n",
 250                                UINPUT_NAME, cnt,
 251                                dev->absmin[cnt], dev->absmax[cnt]);
 252                        retval = -EINVAL;
 253                        break;
 254                }
 255
 256                if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 257                        printk(KERN_DEBUG
 258                                "%s: absflat[%02x] out of range: %d "
 259                                "(min:%d/max:%d)\n",
 260                                UINPUT_NAME, cnt, dev->absflat[cnt],
 261                                dev->absmin[cnt], dev->absmax[cnt]);
 262                        retval = -EINVAL;
 263                        break;
 264                }
 265        }
 266        return retval;
 267}
 268
 269static int uinput_allocate_device(struct uinput_device *udev)
 270{
 271        udev->dev = input_allocate_device();
 272        if (!udev->dev)
 273                return -ENOMEM;
 274
 275        udev->dev->event = uinput_dev_event;
 276        input_set_drvdata(udev->dev, udev);
 277
 278        return 0;
 279}
 280
 281static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 282{
 283        struct uinput_user_dev  *user_dev;
 284        struct input_dev        *dev;
 285        char                    *name;
 286        int                     size;
 287        int                     retval;
 288
 289        if (count != sizeof(struct uinput_user_dev))
 290                return -EINVAL;
 291
 292        if (!udev->dev) {
 293                retval = uinput_allocate_device(udev);
 294                if (retval)
 295                        return retval;
 296        }
 297
 298        dev = udev->dev;
 299
 300        user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 301        if (!user_dev)
 302                return -ENOMEM;
 303
 304        if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 305                retval = -EFAULT;
 306                goto exit;
 307        }
 308
 309        udev->ff_effects_max = user_dev->ff_effects_max;
 310
 311        size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 312        if (!size) {
 313                retval = -EINVAL;
 314                goto exit;
 315        }
 316
 317        kfree(dev->name);
 318        dev->name = name = kmalloc(size, GFP_KERNEL);
 319        if (!name) {
 320                retval = -ENOMEM;
 321                goto exit;
 322        }
 323        strlcpy(name, user_dev->name, size);
 324
 325        dev->id.bustype = user_dev->id.bustype;
 326        dev->id.vendor  = user_dev->id.vendor;
 327        dev->id.product = user_dev->id.product;
 328        dev->id.version = user_dev->id.version;
 329
 330        size = sizeof(int) * (ABS_MAX + 1);
 331        memcpy(dev->absmax, user_dev->absmax, size);
 332        memcpy(dev->absmin, user_dev->absmin, size);
 333        memcpy(dev->absfuzz, user_dev->absfuzz, size);
 334        memcpy(dev->absflat, user_dev->absflat, size);
 335
 336        /* check if absmin/absmax/absfuzz/absflat are filled as
 337         * told in Documentation/input/input-programming.txt */
 338        if (test_bit(EV_ABS, dev->evbit)) {
 339                retval = uinput_validate_absbits(dev);
 340                if (retval < 0)
 341                        goto exit;
 342        }
 343
 344        udev->state = UIST_SETUP_COMPLETE;
 345        retval = count;
 346
 347 exit:
 348        kfree(user_dev);
 349        return retval;
 350}
 351
 352static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 353{
 354        struct input_event ev;
 355
 356        if (count != sizeof(struct input_event))
 357                return -EINVAL;
 358
 359        if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 360                return -EFAULT;
 361
 362        input_event(udev->dev, ev.type, ev.code, ev.value);
 363
 364        return sizeof(struct input_event);
 365}
 366
 367static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 368{
 369        struct uinput_device *udev = file->private_data;
 370        int retval;
 371
 372        retval = mutex_lock_interruptible(&udev->mutex);
 373        if (retval)
 374                return retval;
 375
 376        retval = udev->state == UIST_CREATED ?
 377                        uinput_inject_event(udev, buffer, count) :
 378                        uinput_setup_device(udev, buffer, count);
 379
 380        mutex_unlock(&udev->mutex);
 381
 382        return retval;
 383}
 384
 385static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 386{
 387        struct uinput_device *udev = file->private_data;
 388        int retval = 0;
 389
 390        if (udev->state != UIST_CREATED)
 391                return -ENODEV;
 392
 393        if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 394                return -EAGAIN;
 395
 396        retval = wait_event_interruptible(udev->waitq,
 397                        udev->head != udev->tail || udev->state != UIST_CREATED);
 398        if (retval)
 399                return retval;
 400
 401        retval = mutex_lock_interruptible(&udev->mutex);
 402        if (retval)
 403                return retval;
 404
 405        if (udev->state != UIST_CREATED) {
 406                retval = -ENODEV;
 407                goto out;
 408        }
 409
 410        while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 411                if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 412                        retval = -EFAULT;
 413                        goto out;
 414                }
 415                udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 416                retval += sizeof(struct input_event);
 417        }
 418
 419 out:
 420        mutex_unlock(&udev->mutex);
 421
 422        return retval;
 423}
 424
 425static unsigned int uinput_poll(struct file *file, poll_table *wait)
 426{
 427        struct uinput_device *udev = file->private_data;
 428
 429        poll_wait(file, &udev->waitq, wait);
 430
 431        if (udev->head != udev->tail)
 432                return POLLIN | POLLRDNORM;
 433
 434        return 0;
 435}
 436
 437static int uinput_release(struct inode *inode, struct file *file)
 438{
 439        struct uinput_device *udev = file->private_data;
 440
 441        uinput_destroy_device(udev);
 442        kfree(udev);
 443
 444        return 0;
 445}
 446
 447#define uinput_set_bit(_arg, _bit, _max)                \
 448({                                                      \
 449        int __ret = 0;                                  \
 450        if (udev->state == UIST_CREATED)                \
 451                __ret =  -EINVAL;                       \
 452        else if ((_arg) > (_max))                       \
 453                __ret = -EINVAL;                        \
 454        else set_bit((_arg), udev->dev->_bit);          \
 455        __ret;                                          \
 456})
 457
 458static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 459{
 460        int                     retval;
 461        struct uinput_device    *udev;
 462        void __user             *p = (void __user *)arg;
 463        struct uinput_ff_upload ff_up;
 464        struct uinput_ff_erase  ff_erase;
 465        struct uinput_request   *req;
 466        int                     length;
 467        char                    *phys;
 468
 469        udev = file->private_data;
 470
 471        retval = mutex_lock_interruptible(&udev->mutex);
 472        if (retval)
 473                return retval;
 474
 475        if (!udev->dev) {
 476                retval = uinput_allocate_device(udev);
 477                if (retval)
 478                        goto out;
 479        }
 480
 481        switch (cmd) {
 482                case UI_DEV_CREATE:
 483                        retval = uinput_create_device(udev);
 484                        break;
 485
 486                case UI_DEV_DESTROY:
 487                        uinput_destroy_device(udev);
 488                        break;
 489
 490                case UI_SET_EVBIT:
 491                        retval = uinput_set_bit(arg, evbit, EV_MAX);
 492                        break;
 493
 494                case UI_SET_KEYBIT:
 495                        retval = uinput_set_bit(arg, keybit, KEY_MAX);
 496                        break;
 497
 498                case UI_SET_RELBIT:
 499                        retval = uinput_set_bit(arg, relbit, REL_MAX);
 500                        break;
 501
 502                case UI_SET_ABSBIT:
 503                        retval = uinput_set_bit(arg, absbit, ABS_MAX);
 504                        break;
 505
 506                case UI_SET_MSCBIT:
 507                        retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 508                        break;
 509
 510                case UI_SET_LEDBIT:
 511                        retval = uinput_set_bit(arg, ledbit, LED_MAX);
 512                        break;
 513
 514                case UI_SET_SNDBIT:
 515                        retval = uinput_set_bit(arg, sndbit, SND_MAX);
 516                        break;
 517
 518                case UI_SET_FFBIT:
 519                        retval = uinput_set_bit(arg, ffbit, FF_MAX);
 520                        break;
 521
 522                case UI_SET_SWBIT:
 523                        retval = uinput_set_bit(arg, swbit, SW_MAX);
 524                        break;
 525
 526                case UI_SET_PHYS:
 527                        if (udev->state == UIST_CREATED) {
 528                                retval = -EINVAL;
 529                                goto out;
 530                        }
 531                        length = strnlen_user(p, 1024);
 532                        if (length <= 0) {
 533                                retval = -EFAULT;
 534                                break;
 535                        }
 536                        kfree(udev->dev->phys);
 537                        udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 538                        if (!phys) {
 539                                retval = -ENOMEM;
 540                                break;
 541                        }
 542                        if (copy_from_user(phys, p, length)) {
 543                                udev->dev->phys = NULL;
 544                                kfree(phys);
 545                                retval = -EFAULT;
 546                                break;
 547                        }
 548                        phys[length - 1] = '\0';
 549                        break;
 550
 551                case UI_BEGIN_FF_UPLOAD:
 552                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 553                                retval = -EFAULT;
 554                                break;
 555                        }
 556                        req = uinput_request_find(udev, ff_up.request_id);
 557                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 558                                retval = -EINVAL;
 559                                break;
 560                        }
 561                        ff_up.retval = 0;
 562                        memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
 563                        if (req->u.upload.old)
 564                                memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
 565                        else
 566                                memset(&ff_up.old, 0, sizeof(struct ff_effect));
 567
 568                        if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 569                                retval = -EFAULT;
 570                                break;
 571                        }
 572                        break;
 573
 574                case UI_BEGIN_FF_ERASE:
 575                        if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 576                                retval = -EFAULT;
 577                                break;
 578                        }
 579                        req = uinput_request_find(udev, ff_erase.request_id);
 580                        if (!(req && req->code == UI_FF_ERASE)) {
 581                                retval = -EINVAL;
 582                                break;
 583                        }
 584                        ff_erase.retval = 0;
 585                        ff_erase.effect_id = req->u.effect_id;
 586                        if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 587                                retval = -EFAULT;
 588                                break;
 589                        }
 590                        break;
 591
 592                case UI_END_FF_UPLOAD:
 593                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 594                                retval = -EFAULT;
 595                                break;
 596                        }
 597                        req = uinput_request_find(udev, ff_up.request_id);
 598                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 599                                retval = -EINVAL;
 600                                break;
 601                        }
 602                        req->retval = ff_up.retval;
 603                        uinput_request_done(udev, req);
 604                        break;
 605
 606                case UI_END_FF_ERASE:
 607                        if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 608                                retval = -EFAULT;
 609                                break;
 610                        }
 611                        req = uinput_request_find(udev, ff_erase.request_id);
 612                        if (!(req && req->code == UI_FF_ERASE)) {
 613                                retval = -EINVAL;
 614                                break;
 615                        }
 616                        req->retval = ff_erase.retval;
 617                        uinput_request_done(udev, req);
 618                        break;
 619
 620                default:
 621                        retval = -EINVAL;
 622        }
 623
 624 out:
 625        mutex_unlock(&udev->mutex);
 626        return retval;
 627}
 628
 629static const struct file_operations uinput_fops = {
 630        .owner          = THIS_MODULE,
 631        .open           = uinput_open,
 632        .release        = uinput_release,
 633        .read           = uinput_read,
 634        .write          = uinput_write,
 635        .poll           = uinput_poll,
 636        .unlocked_ioctl = uinput_ioctl,
 637};
 638
 639static struct miscdevice uinput_misc = {
 640        .fops           = &uinput_fops,
 641        .minor          = UINPUT_MINOR,
 642        .name           = UINPUT_NAME,
 643};
 644
 645static int __init uinput_init(void)
 646{
 647        return misc_register(&uinput_misc);
 648}
 649
 650static void __exit uinput_exit(void)
 651{
 652        misc_deregister(&uinput_misc);
 653}
 654
 655MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 656MODULE_DESCRIPTION("User level driver support for input subsystem");
 657MODULE_LICENSE("GPL");
 658MODULE_VERSION("0.3");
 659
 660module_init(uinput_init);
 661module_exit(uinput_exit);
 662
 663
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