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/smp_lock.h>
  37 #include <linux/fs.h>
  38 #include <linux/miscdevice.h>
  39 #include <linux/uinput.h>
  40
  41 static 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
  56 static 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
  76 static 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
  84 static 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
  91 static 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
 100 static 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
 110 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 111 {
 112         uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 113 }
 114
 115 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 116 {
 117         uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 118 }
 119
 120 static 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
 125 static 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
 143 static 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
 163 static 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
 182 static 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
 217 static 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
 236 static 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
 267 static 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
 279 static 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
 350 static 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
 365 static 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
 383 static 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
 423 static 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
 435 static 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
 456 static 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
 627 static 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
 637 static struct miscdevice uinput_misc = {
 638         .fops           = &uinput_fops,
 639         .minor          = UINPUT_MINOR,
 640         .name           = UINPUT_NAME,
 641 };
 642
 643 static int __init uinput_init(void)
 644 {
 645         return misc_register(&uinput_misc);
 646 }
 647
 648 static void __exit uinput_exit(void)
 649 {
 650         misc_deregister(&uinput_misc);
 651 }
 652
 653 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 654 MODULE_DESCRIPTION("User level driver support for input subsystem");
 655 MODULE_LICENSE("GPL");
 656 MODULE_VERSION("0.3");
 657
 658 module_init(uinput_init);
 659 module_exit(uinput_exit);
 660