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_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  40 {
  41         struct uinput_device    *udev;
  42
  43         udev = dev->private;
  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_interruptible(&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         int retval;
 103
 104         /* Tell our userspace app about this new request by queueing an input event */
 105         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 106
 107         /* Wait for the request to complete */
 108         retval = wait_for_completion_interruptible(&request->done);
 109         if (!retval)
 110                 retval = request->retval;
 111
 112         return retval;
 113 }
 114
 115 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
 116 {
 117         struct uinput_request request;
 118         int retval;
 119
 120         if (!test_bit(EV_FF, dev->evbit))
 121                 return -ENOSYS;
 122
 123         request.id = -1;
 124         init_completion(&request.done);
 125         request.code = UI_FF_UPLOAD;
 126         request.u.effect = effect;
 127
 128         retval = uinput_request_reserve_slot(dev->private, &request);
 129         if (!retval)
 130                 retval = uinput_request_submit(dev, &request);
 131
 132         return retval;
 133 }
 134
 135 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 136 {
 137         struct uinput_request request;
 138         int retval;
 139
 140         if (!test_bit(EV_FF, dev->evbit))
 141                 return -ENOSYS;
 142
 143         request.id = -1;
 144         init_completion(&request.done);
 145         request.code = UI_FF_ERASE;
 146         request.u.effect_id = effect_id;
 147
 148         retval = uinput_request_reserve_slot(dev->private, &request);
 149         if (!retval)
 150                 retval = uinput_request_submit(dev, &request);
 151
 152         return 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->event = uinput_dev_event;
 163         udev->dev->upload_effect = uinput_dev_upload_effect;
 164         udev->dev->erase_effect = uinput_dev_erase_effect;
 165         udev->dev->private = udev;
 166
 167         init_waitqueue_head(&udev->waitq);
 168
 169         input_register_device(udev->dev);
 170
 171         set_bit(UIST_CREATED, &udev->state);
 172
 173         return 0;
 174 }
 175
 176 static int uinput_destroy_device(struct uinput_device *udev)
 177 {
 178         if (!test_bit(UIST_CREATED, &udev->state)) {
 179                 printk(KERN_WARNING "%s: create the device first\n", UINPUT_NAME);
 180                 return -EINVAL;
 181         }
 182
 183         input_unregister_device(udev->dev);
 184
 185         clear_bit(UIST_CREATED, &udev->state);
 186
 187         return 0;
 188 }
 189
 190 static int uinput_open(struct inode *inode, struct file *file)
 191 {
 192         struct uinput_device    *newdev;
 193         struct input_dev        *newinput;
 194
 195         newdev = kmalloc(sizeof(struct uinput_device), GFP_KERNEL);
 196         if (!newdev)
 197                 goto error;
 198         memset(newdev, 0, sizeof(struct uinput_device));
 199         spin_lock_init(&newdev->requests_lock);
 200         init_waitqueue_head(&newdev->requests_waitq);
 201
 202         newinput = kmalloc(sizeof(struct input_dev), GFP_KERNEL);
 203         if (!newinput)
 204                 goto cleanup;
 205         memset(newinput, 0, sizeof(struct input_dev));
 206
 207         newdev->dev = newinput;
 208
 209         file->private_data = newdev;
 210
 211         return 0;
 212 cleanup:
 213         kfree(newdev);
 214 error:
 215         return -ENOMEM;
 216 }
 217
 218 static int uinput_validate_absbits(struct input_dev *dev)
 219 {
 220         unsigned int cnt;
 221         int retval = 0;
 222
 223         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 224                 if (!test_bit(cnt, dev->absbit))
 225                         continue;
 226
 227                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 228                         printk(KERN_DEBUG
 229                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 230                                 UINPUT_NAME, cnt,
 231                                 dev->absmin[cnt], dev->absmax[cnt]);
 232                         retval = -EINVAL;
 233                         break;
 234                 }
 235
 236                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 237                         printk(KERN_DEBUG
 238                                 "%s: absflat[%02x] out of range: %d "
 239                                 "(min:%d/max:%d)\n",
 240                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 241                                 dev->absmin[cnt], dev->absmax[cnt]);
 242                         retval = -EINVAL;
 243                         break;
 244                 }
 245         }
 246         return retval;
 247 }
 248
 249 static int uinput_alloc_device(struct file *file, const char __user *buffer, size_t count)
 250 {
 251         struct uinput_user_dev  *user_dev;
 252         struct input_dev        *dev;
 253         struct uinput_device    *udev;
 254         char                    *name;
 255         int                     size;
 256         int                     retval;
 257
 258         retval = count;
 259
 260         udev = file->private_data;
 261         dev = udev->dev;
 262
 263         user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 264         if (!user_dev) {
 265                 retval = -ENOMEM;
 266                 goto exit;
 267         }
 268
 269         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 270                 retval = -EFAULT;
 271                 goto exit;
 272         }
 273
 274         kfree(dev->name);
 275
 276         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 277         dev->name = name = kmalloc(size, GFP_KERNEL);
 278         if (!name) {
 279                 retval = -ENOMEM;
 280                 goto exit;
 281         }
 282         strlcpy(name, user_dev->name, size);
 283
 284         dev->id.bustype = user_dev->id.bustype;
 285         dev->id.vendor  = user_dev->id.vendor;
 286         dev->id.product = user_dev->id.product;
 287         dev->id.version = user_dev->id.version;
 288         dev->ff_effects_max = user_dev->ff_effects_max;
 289
 290         size = sizeof(int) * (ABS_MAX + 1);
 291         memcpy(dev->absmax, user_dev->absmax, size);
 292         memcpy(dev->absmin, user_dev->absmin, size);
 293         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 294         memcpy(dev->absflat, user_dev->absflat, size);
 295
 296         /* check if absmin/absmax/absfuzz/absflat are filled as
 297          * told in Documentation/input/input-programming.txt */
 298         if (test_bit(EV_ABS, dev->evbit)) {
 299                 int err = uinput_validate_absbits(dev);
 300                 if (err < 0) {
 301                         retval = err;
 302                         kfree(dev->name);
 303                 }
 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         } else
 322                 count = uinput_alloc_device(file, buffer, count);
 323
 324         return count;
 325 }
 326
 327 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 328 {
 329         struct uinput_device *udev = file->private_data;
 330         int retval = 0;
 331
 332         if (!test_bit(UIST_CREATED, &udev->state))
 333                 return -ENODEV;
 334
 335         if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 336                 return -EAGAIN;
 337
 338         retval = wait_event_interruptible(udev->waitq,
 339                         udev->head != udev->tail || !test_bit(UIST_CREATED, &udev->state));
 340         if (retval)
 341                 return retval;
 342
 343         if (!test_bit(UIST_CREATED, &udev->state))
 344                 return -ENODEV;
 345
 346         while ((udev->head != udev->tail) &&
 347             (retval + sizeof(struct input_event) <= count)) {
 348                 if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event)))
 349                         return -EFAULT;
 350                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 351                 retval += sizeof(struct input_event);
 352         }
 353
 354         return retval;
 355 }
 356
 357 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 358 {
 359         struct uinput_device *udev = file->private_data;
 360
 361         poll_wait(file, &udev->waitq, wait);
 362
 363         if (udev->head != udev->tail)
 364                 return POLLIN | POLLRDNORM;
 365
 366         return 0;
 367 }
 368
 369 static int uinput_burn_device(struct uinput_device *udev)
 370 {
 371         if (test_bit(UIST_CREATED, &udev->state))
 372                 uinput_destroy_device(udev);
 373
 374         kfree(udev->dev->name);
 375         kfree(udev->dev->phys);
 376         kfree(udev->dev);
 377         kfree(udev);
 378
 379         return 0;
 380 }
 381
 382 static int uinput_close(struct inode *inode, struct file *file)
 383 {
 384         uinput_burn_device(file->private_data);
 385         return 0;
 386 }
 387
 388 static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 389 {
 390         int                     retval = 0;
 391         struct uinput_device    *udev;
 392         void __user             *p = (void __user *)arg;
 393         struct uinput_ff_upload ff_up;
 394         struct uinput_ff_erase  ff_erase;
 395         struct uinput_request   *req;
 396         int                     length;
 397         char                    *phys;
 398
 399         udev = file->private_data;
 400
 401         /* device attributes can not be changed after the device is created */
 402         switch (cmd) {
 403                 case UI_SET_EVBIT:
 404                 case UI_SET_KEYBIT:
 405                 case UI_SET_RELBIT:
 406                 case UI_SET_ABSBIT:
 407                 case UI_SET_MSCBIT:
 408                 case UI_SET_LEDBIT:
 409                 case UI_SET_SNDBIT:
 410                 case UI_SET_FFBIT:
 411                 case UI_SET_PHYS:
 412                         if (test_bit(UIST_CREATED, &udev->state))
 413                                 return -EINVAL;
 414         }
 415
 416         switch (cmd) {
 417                 case UI_DEV_CREATE:
 418                         retval = uinput_create_device(udev);
 419                         break;
 420
 421                 case UI_DEV_DESTROY:
 422                         retval = uinput_destroy_device(udev);
 423                         break;
 424
 425                 case UI_SET_EVBIT:
 426                         if (arg > EV_MAX) {
 427                                 retval = -EINVAL;
 428                                 break;
 429                         }
 430                         set_bit(arg, udev->dev->evbit);
 431                         break;
 432
 433                 case UI_SET_KEYBIT:
 434                         if (arg > KEY_MAX) {
 435                                 retval = -EINVAL;
 436                                 break;
 437                         }
 438                         set_bit(arg, udev->dev->keybit);
 439                         break;
 440
 441                 case UI_SET_RELBIT:
 442                         if (arg > REL_MAX) {
 443                                 retval = -EINVAL;
 444                                 break;
 445                         }
 446                         set_bit(arg, udev->dev->relbit);
 447                         break;
 448
 449                 case UI_SET_ABSBIT:
 450                         if (arg > ABS_MAX) {
 451                                 retval = -EINVAL;
 452                                 break;
 453                         }
 454                         set_bit(arg, udev->dev->absbit);
 455                         break;
 456
 457                 case UI_SET_MSCBIT:
 458                         if (arg > MSC_MAX) {
 459                                 retval = -EINVAL;
 460                                 break;
 461                         }
 462                         set_bit(arg, udev->dev->mscbit);
 463                         break;
 464
 465                 case UI_SET_LEDBIT:
 466                         if (arg > LED_MAX) {
 467                                 retval = -EINVAL;
 468                                 break;
 469                         }
 470                         set_bit(arg, udev->dev->ledbit);
 471                         break;
 472
 473                 case UI_SET_SNDBIT:
 474                         if (arg > SND_MAX) {
 475                                 retval = -EINVAL;
 476                                 break;
 477                         }
 478                         set_bit(arg, udev->dev->sndbit);
 479                         break;
 480
 481                 case UI_SET_FFBIT:
 482                         if (arg > FF_MAX) {
 483                                 retval = -EINVAL;
 484                                 break;
 485                         }
 486                         set_bit(arg, udev->dev->ffbit);
 487                         break;
 488
 489                 case UI_SET_PHYS:
 490                         length = strnlen_user(p, 1024);
 491                         if (length <= 0) {
 492                                 retval = -EFAULT;
 493                                 break;
 494                         }
 495                         kfree(udev->dev->phys);
 496                         udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 497                         if (!phys) {
 498                                 retval = -ENOMEM;
 499                                 break;
 500                         }
 501                         if (copy_from_user(phys, p, length)) {
 502                                 udev->dev->phys = NULL;
 503                                 kfree(phys);
 504                                 retval = -EFAULT;
 505                                 break;
 506                         }
 507                         phys[length - 1] = '\0';
 508                         break;
 509
 510                 case UI_BEGIN_FF_UPLOAD:
 511                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 512                                 retval = -EFAULT;
 513                                 break;
 514                         }
 515                         req = uinput_request_find(udev, ff_up.request_id);
 516                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 517                                 retval = -EINVAL;
 518                                 break;
 519                         }
 520                         ff_up.retval = 0;
 521                         memcpy(&ff_up.effect, req->u.effect, sizeof(struct ff_effect));
 522                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 523                                 retval = -EFAULT;
 524                                 break;
 525                         }
 526                         break;
 527
 528                 case UI_BEGIN_FF_ERASE:
 529                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 530                                 retval = -EFAULT;
 531                                 break;
 532                         }
 533                         req = uinput_request_find(udev, ff_erase.request_id);
 534                         if (!(req && req->code == UI_FF_ERASE)) {
 535                                 retval = -EINVAL;
 536                                 break;
 537                         }
 538                         ff_erase.retval = 0;
 539                         ff_erase.effect_id = req->u.effect_id;
 540                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 541                                 retval = -EFAULT;
 542                                 break;
 543                         }
 544                         break;
 545
 546                 case UI_END_FF_UPLOAD:
 547                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 548                                 retval = -EFAULT;
 549                                 break;
 550                         }
 551                         req = uinput_request_find(udev, ff_up.request_id);
 552                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 553                                 retval = -EINVAL;
 554                                 break;
 555                         }
 556                         req->retval = ff_up.retval;
 557                         memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
 558                         uinput_request_done(udev, req);
 559                         break;
 560
 561                 case UI_END_FF_ERASE:
 562                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 563                                 retval = -EFAULT;
 564                                 break;
 565                         }
 566                         req = uinput_request_find(udev, ff_erase.request_id);
 567                         if (!(req && req->code == UI_FF_ERASE)) {
 568                                 retval = -EINVAL;
 569                                 break;
 570                         }
 571                         req->retval = ff_erase.retval;
 572                         uinput_request_done(udev, req);
 573                         break;
 574
 575                 default:
 576                         retval = -EINVAL;
 577         }
 578         return retval;
 579 }
 580
 581 static struct file_operations uinput_fops = {
 582         .owner =        THIS_MODULE,
 583         .open =         uinput_open,
 584         .release =      uinput_close,
 585         .read =         uinput_read,
 586         .write =        uinput_write,
 587         .poll =         uinput_poll,
 588         .ioctl =        uinput_ioctl,
 589 };
 590
 591 static struct miscdevice uinput_misc = {
 592         .fops =         &uinput_fops,
 593         .minor =        UINPUT_MINOR,
 594         .name =         UINPUT_NAME,
 595 };
 596
 597 static int __init uinput_init(void)
 598 {
 599         return misc_register(&uinput_misc);
 600 }
 601
 602 static void __exit uinput_exit(void)
 603 {
 604         misc_deregister(&uinput_misc);
 605 }
 606
 607 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 608 MODULE_DESCRIPTION("User level driver support for input subsystem");
 609 MODULE_LICENSE("GPL");
 610
 611 module_init(uinput_init);
 612 module_exit(uinput_exit);
 613