drivers/input/misc/uinput.c

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