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  *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  24  *              - added force feedback support
  25  *              - added UI_SET_PHYS
  26  *      0.1     20/06/2002
  27  *              - first public version
  28  */
  29 #include <linux/poll.h>
  30 #include <linux/slab.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/input.h>
  34 #include <linux/smp_lock.h>
  35 #include <linux/fs.h>
  36 #include <linux/miscdevice.h>
  37 #include <linux/uinput.h>
  38
  39 static int uinput_dev_open(struct input_dev *dev)
  40 {
  41         return 0;
  42 }
  43
  44 static void uinput_dev_close(struct input_dev *dev)
  45 {
  46
  47 }
  48
  49 static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  50 {
  51         struct uinput_device    *udev;
  52
  53         udev = dev->private;
  54
  55         udev->buff[udev->head].type = type;
  56         udev->buff[udev->head].code = code;
  57         udev->buff[udev->head].value = value;
  58         do_gettimeofday(&udev->buff[udev->head].time);
  59         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  60
  61         wake_up_interruptible(&udev->waitq);
  62
  63         return 0;
  64 }
  65
  66 static int uinput_request_alloc_id(struct input_dev *dev, struct uinput_request *request)
  67 {
  68         /* Atomically allocate an ID for the given request. Returns 0 on success. */
  69         struct uinput_device *udev = dev->private;
  70         int id;
  71
  72         down(&udev->requests_sem);
  73         for (id=0; id<UINPUT_NUM_REQUESTS; id++)
  74                 if (!udev->requests[id]) {
  75                         udev->requests[id] = request;
  76                         request->id = id;
  77                         up(&udev->requests_sem);
  78                         return 0;
  79                 }
  80         up(&udev->requests_sem);
  81         return -1;
  82 }
  83
  84 static struct uinput_request* uinput_request_find(struct uinput_device *udev, int id)
  85 {
  86         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
  87         if (id >= UINPUT_NUM_REQUESTS || id < 0)
  88                 return NULL;
  89         if (udev->requests[id]->completed)
  90                 return NULL;
  91         return udev->requests[id];
  92 }
  93
  94 static void uinput_request_init(struct input_dev *dev, struct uinput_request *request, int code)
  95 {
  96         struct uinput_device *udev = dev->private;
  97
  98         memset(request, 0, sizeof(struct uinput_request));
  99         request->code = code;
 100         init_waitqueue_head(&request->waitq);
 101
 102         /* Allocate an ID. If none are available right away, wait. */
 103         request->retval = wait_event_interruptible(udev->requests_waitq,
 104                                        !uinput_request_alloc_id(dev, request));
 105 }
 106
 107 static void uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 108 {
 109         struct uinput_device *udev = dev->private;
 110         int retval;
 111
 112         /* Tell our userspace app about this new request by queueing an input event */
 113         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 114
 115         /* Wait for the request to complete */
 116         retval = wait_event_interruptible(request->waitq, request->completed);
 117         if (retval)
 118                 request->retval = retval;
 119
 120         /* Release this request's ID, let others know it's available */
 121         udev->requests[request->id] = NULL;
 122         wake_up_interruptible(&udev->requests_waitq);
 123 }
 124
 125 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
 126 {
 127         struct uinput_request request;
 128
 129         if (!test_bit(EV_FF, dev->evbit))
 130                 return -ENOSYS;
 131
 132         uinput_request_init(dev, &request, UI_FF_UPLOAD);
 133         if (request.retval)
 134                 return request.retval;
 135         request.u.effect = effect;
 136         uinput_request_submit(dev, &request);
 137         return request.retval;
 138 }
 139
 140 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 141 {
 142         struct uinput_request request;
 143
 144         if (!test_bit(EV_FF, dev->evbit))
 145                 return -ENOSYS;
 146
 147         uinput_request_init(dev, &request, UI_FF_ERASE);
 148         if (request.retval)
 149                 return request.retval;
 150         request.u.effect_id = effect_id;
 151         uinput_request_submit(dev, &request);
 152         return request.retval;
 153 }
 154
 155 static int uinput_create_device(struct uinput_device *udev)
 156 {
 157         if (!udev->dev->name) {
 158                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 159                 return -EINVAL;
 160         }
 161
 162         udev->dev->open = uinput_dev_open;
 163         udev->dev->close = uinput_dev_close;
 164         udev->dev->event = uinput_dev_event;
 165         udev->dev->upload_effect = uinput_dev_upload_effect;
 166         udev->dev->erase_effect = uinput_dev_erase_effect;
 167         udev->dev->private = udev;
 168
 169         init_waitqueue_head(&(udev->waitq));
 170
 171         input_register_device(udev->dev);
 172
 173         set_bit(UIST_CREATED, &(udev->state));
 174
 175         return 0;
 176 }
 177
 178 static int uinput_destroy_device(struct uinput_device *udev)
 179 {
 180         if (!test_bit(UIST_CREATED, &(udev->state))) {
 181                 printk(KERN_WARNING "%s: create the device first\n", UINPUT_NAME);
 182                 return -EINVAL;
 183         }
 184
 185         input_unregister_device(udev->dev);
 186
 187         clear_bit(UIST_CREATED, &(udev->state));
 188
 189         return 0;
 190 }
 191
 192 static int uinput_open(struct inode *inode, struct file *file)
 193 {
 194         struct uinput_device    *newdev;
 195         struct input_dev        *newinput;
 196
 197         newdev = kmalloc(sizeof(struct uinput_device), GFP_KERNEL);
 198         if (!newdev)
 199                 goto error;
 200         memset(newdev, 0, sizeof(struct uinput_device));
 201         init_MUTEX(&newdev->requests_sem);
 202         init_waitqueue_head(&newdev->requests_waitq);
 203
 204         newinput = kmalloc(sizeof(struct input_dev), GFP_KERNEL);
 205         if (!newinput)
 206                 goto cleanup;
 207         memset(newinput, 0, sizeof(struct input_dev));
 208
 209         newdev->dev = newinput;
 210
 211         file->private_data = newdev;
 212
 213         return 0;
 214 cleanup:
 215         kfree(newdev);
 216 error:
 217         return -ENOMEM;
 218 }
 219
 220 static int uinput_validate_absbits(struct input_dev *dev)
 221 {
 222         unsigned int cnt;
 223         int retval = 0;
 224
 225         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 226                 if (!test_bit(cnt, dev->absbit))
 227                         continue;
 228
 229                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 230                         printk(KERN_DEBUG
 231                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 232                                 UINPUT_NAME, cnt,
 233                                 dev->absmin[cnt], dev->absmax[cnt]);
 234                         retval = -EINVAL;
 235                         break;
 236                 }
 237
 238                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 239                         printk(KERN_DEBUG
 240                                 "%s: absflat[%02x] out of range: %d "
 241                                 "(min:%d/max:%d)\n",
 242                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 243                                 dev->absmin[cnt], dev->absmax[cnt]);
 244                         retval = -EINVAL;
 245                         break;
 246                 }
 247         }
 248         return retval;
 249 }
 250
 251 static int uinput_alloc_device(struct file *file, const char __user *buffer, size_t count)
 252 {
 253         struct uinput_user_dev  *user_dev;
 254         struct input_dev        *dev;
 255         struct uinput_device    *udev;
 256         int                     size,
 257                                 retval;
 258
 259         retval = count;
 260
 261         udev = file->private_data;
 262         dev = udev->dev;
 263
 264         user_dev = kmalloc(sizeof(*user_dev), GFP_KERNEL);
 265         if (!user_dev) {
 266                 retval = -ENOMEM;
 267                 goto exit;
 268         }
 269
 270         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 271                 retval = -EFAULT;
 272                 goto exit;
 273         }
 274
 275         if (NULL != dev->name)
 276                 kfree(dev->name);
 277
 278         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 279         dev->name = kmalloc(size, GFP_KERNEL);
 280         if (!dev->name) {
 281                 retval = -ENOMEM;
 282                 goto exit;
 283         }
 284
 285         strlcpy(dev->name, user_dev->name, size);
 286         dev->id.bustype = user_dev->id.bustype;
 287         dev->id.vendor  = user_dev->id.vendor;
 288         dev->id.product = user_dev->id.product;
 289         dev->id.version = user_dev->id.version;
 290         dev->ff_effects_max = user_dev->ff_effects_max;
 291
 292         size = sizeof(int) * (ABS_MAX + 1);
 293         memcpy(dev->absmax, user_dev->absmax, size);
 294         memcpy(dev->absmin, user_dev->absmin, size);
 295         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 296         memcpy(dev->absflat, user_dev->absflat, size);
 297
 298         /* check if absmin/absmax/absfuzz/absflat are filled as
 299          * told in Documentation/input/input-programming.txt */
 300         if (test_bit(EV_ABS, dev->evbit)) {
 301                 retval = uinput_validate_absbits(dev);
 302                 if (retval < 0)
 303                         kfree(dev->name);
 304         }
 305
 306 exit:
 307         kfree(user_dev);
 308         return retval;
 309 }
 310
 311 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 312 {
 313         struct uinput_device *udev = file->private_data;
 314
 315         if (test_bit(UIST_CREATED, &(udev->state))) {
 316                 struct input_event      ev;
 317
 318                 if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 319                         return -EFAULT;
 320                 input_event(udev->dev, ev.type, ev.code, ev.value);
 321         }
 322         else
 323                 count = uinput_alloc_device(file, buffer, count);
 324
 325         return count;
 326 }
 327
 328 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 329 {
 330         struct uinput_device *udev = file->private_data;
 331         int retval = 0;
 332
 333         if (!test_bit(UIST_CREATED, &(udev->state)))
 334                 return -ENODEV;
 335
 336         if ((udev->head == udev->tail) && (file->f_flags & O_NONBLOCK))
 337                 return -EAGAIN;
 338
 339         retval = wait_event_interruptible(udev->waitq,
 340                         (udev->head != udev->tail) ||
 341                         !test_bit(UIST_CREATED, &(udev->state)));
 342
 343         if (retval)
 344                 return retval;
 345
 346         if (!test_bit(UIST_CREATED, &(udev->state)))
 347                 return -ENODEV;
 348
 349         while ((udev->head != udev->tail) &&
 350             (retval + sizeof(struct input_event) <= count)) {
 351                 if (copy_to_user(buffer + retval, &(udev->buff[udev->tail]),
 352                     sizeof(struct input_event))) return -EFAULT;
 353                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 354                 retval += sizeof(struct input_event);
 355         }
 356
 357         return retval;
 358 }
 359
 360 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 361 {
 362         struct uinput_device *udev = file->private_data;
 363
 364         poll_wait(file, &udev->waitq, wait);
 365
 366         if (udev->head != udev->tail)
 367                 return POLLIN | POLLRDNORM;
 368
 369         return 0;
 370 }
 371
 372 static int uinput_burn_device(struct uinput_device *udev)
 373 {
 374         if (test_bit(UIST_CREATED, &(udev->state)))
 375                 uinput_destroy_device(udev);
 376
 377         if (NULL != udev->dev->name)
 378                 kfree(udev->dev->name);
 379         if (NULL != udev->dev->phys)
 380                 kfree(udev->dev->phys);
 381
 382         kfree(udev->dev);
 383         kfree(udev);
 384
 385         return 0;
 386 }
 387
 388 static int uinput_close(struct inode *inode, struct file *file)
 389 {
 390         return uinput_burn_device(file->private_data);
 391 }
 392
 393 static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 394 {
 395         int                     retval = 0;
 396         struct uinput_device    *udev;
 397         void __user             *p = (void __user *)arg;
 398         struct uinput_ff_upload ff_up;
 399         struct uinput_ff_erase  ff_erase;
 400         struct uinput_request   *req;
 401         int                     length;
 402
 403         udev = file->private_data;
 404
 405         /* device attributes can not be changed after the device is created */
 406         switch (cmd) {
 407                 case UI_SET_EVBIT:
 408                 case UI_SET_KEYBIT:
 409                 case UI_SET_RELBIT:
 410                 case UI_SET_ABSBIT:
 411                 case UI_SET_MSCBIT:
 412                 case UI_SET_LEDBIT:
 413                 case UI_SET_SNDBIT:
 414                 case UI_SET_FFBIT:
 415                 case UI_SET_PHYS:
 416                         if (test_bit(UIST_CREATED, &(udev->state)))
 417                                 return -EINVAL;
 418         }
 419
 420         switch (cmd) {
 421                 case UI_DEV_CREATE:
 422                         retval = uinput_create_device(udev);
 423                         break;
 424
 425                 case UI_DEV_DESTROY:
 426                         retval = uinput_destroy_device(udev);
 427                         break;
 428
 429                 case UI_SET_EVBIT:
 430                         if (arg > EV_MAX) {
 431                                 retval = -EINVAL;
 432                                 break;
 433                         }
 434                         set_bit(arg, udev->dev->evbit);
 435                         break;
 436
 437                 case UI_SET_KEYBIT:
 438                         if (arg > KEY_MAX) {
 439                                 retval = -EINVAL;
 440                                 break;
 441                         }
 442                         set_bit(arg, udev->dev->keybit);
 443                         break;
 444
 445                 case UI_SET_RELBIT:
 446                         if (arg > REL_MAX) {
 447                                 retval = -EINVAL;
 448                                 break;
 449                         }
 450                         set_bit(arg, udev->dev->relbit);
 451                         break;
 452
 453                 case UI_SET_ABSBIT:
 454                         if (arg > ABS_MAX) {
 455                                 retval = -EINVAL;
 456                                 break;
 457                         }
 458                         set_bit(arg, udev->dev->absbit);
 459                         break;
 460
 461                 case UI_SET_MSCBIT:
 462                         if (arg > MSC_MAX) {
 463                                 retval = -EINVAL;
 464                                 break;
 465                         }
 466                         set_bit(arg, udev->dev->mscbit);
 467                         break;
 468
 469                 case UI_SET_LEDBIT:
 470                         if (arg > LED_MAX) {
 471                                 retval = -EINVAL;
 472                                 break;
 473                         }
 474                         set_bit(arg, udev->dev->ledbit);
 475                         break;
 476
 477                 case UI_SET_SNDBIT:
 478                         if (arg > SND_MAX) {
 479                                 retval = -EINVAL;
 480                                 break;
 481                         }
 482                         set_bit(arg, udev->dev->sndbit);
 483                         break;
 484
 485                 case UI_SET_FFBIT:
 486                         if (arg > FF_MAX) {
 487                                 retval = -EINVAL;
 488                                 break;
 489                         }
 490                         set_bit(arg, udev->dev->ffbit);
 491                         break;
 492
 493                 case UI_SET_PHYS:
 494                         length = strnlen_user(p, 1024);
 495                         if (length <= 0) {
 496                                 retval = -EFAULT;
 497                                 break;
 498                         }
 499                         if (NULL != udev->dev->phys)
 500                                 kfree(udev->dev->phys);
 501                         udev->dev->phys = kmalloc(length, GFP_KERNEL);
 502                         if (!udev->dev->phys) {
 503                                 retval = -ENOMEM;
 504                                 break;
 505                         }
 506                         if (copy_from_user(udev->dev->phys, p, length)) {
 507                                 retval = -EFAULT;
 508                                 kfree(udev->dev->phys);
 509                                 udev->dev->phys = NULL;
 510                                 break;
 511                         }
 512                         udev->dev->phys[length-1] = '\0';
 513                         break;
 514
 515                 case UI_BEGIN_FF_UPLOAD:
 516                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 517                                 retval = -EFAULT;
 518                                 break;
 519                         }
 520                         req = uinput_request_find(udev, ff_up.request_id);
 521                         if (!(req && req->code==UI_FF_UPLOAD && req->u.effect)) {
 522                                 retval = -EINVAL;
 523                                 break;
 524                         }
 525                         ff_up.retval = 0;
 526                         memcpy(&ff_up.effect, req->u.effect, sizeof(struct ff_effect));
 527                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 528                                 retval = -EFAULT;
 529                                 break;
 530                         }
 531                         break;
 532
 533                 case UI_BEGIN_FF_ERASE:
 534                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 535                                 retval = -EFAULT;
 536                                 break;
 537                         }
 538                         req = uinput_request_find(udev, ff_erase.request_id);
 539                         if (!(req && req->code==UI_FF_ERASE)) {
 540                                 retval = -EINVAL;
 541                                 break;
 542                         }
 543                         ff_erase.retval = 0;
 544                         ff_erase.effect_id = req->u.effect_id;
 545                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 546                                 retval = -EFAULT;
 547                                 break;
 548                         }
 549                         break;
 550
 551                 case UI_END_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.effect)) {
 558                                 retval = -EINVAL;
 559                                 break;
 560                         }
 561                         req->retval = ff_up.retval;
 562                         memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
 563                         req->completed = 1;
 564                         wake_up_interruptible(&req->waitq);
 565                         break;
 566
 567                 case UI_END_FF_ERASE:
 568                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 569                                 retval = -EFAULT;
 570                                 break;
 571                         }
 572                         req = uinput_request_find(udev, ff_erase.request_id);
 573                         if (!(req && req->code==UI_FF_ERASE)) {
 574                                 retval = -EINVAL;
 575                                 break;
 576                         }
 577                         req->retval = ff_erase.retval;
 578                         req->completed = 1;
 579                         wake_up_interruptible(&req->waitq);
 580                         break;
 581
 582                 default:
 583                         retval = -EINVAL;
 584         }
 585         return retval;
 586 }
 587
 588 static struct file_operations uinput_fops = {
 589         .owner =        THIS_MODULE,
 590         .open =         uinput_open,
 591         .release =      uinput_close,
 592         .read =         uinput_read,
 593         .write =        uinput_write,
 594         .poll =         uinput_poll,
 595         .ioctl =        uinput_ioctl,
 596 };
 597
 598 static struct miscdevice uinput_misc = {
 599         .fops =         &uinput_fops,
 600         .minor =        UINPUT_MINOR,
 601         .name =         UINPUT_NAME,
 602 };
 603
 604 static int __init uinput_init(void)
 605 {
 606         return misc_register(&uinput_misc);
 607 }
 608
 609 static void __exit uinput_exit(void)
 610 {
 611         misc_deregister(&uinput_misc);
 612 }
 613
 614 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 615 MODULE_DESCRIPTION("User level driver support for input subsystem");
 616 MODULE_LICENSE("GPL");
 617
 618 module_init(uinput_init);
 619 module_exit(uinput_exit);
 620