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 void uinput_destroy_device(struct uinput_device *udev)
 156 {
 157         const char *name, *phys;
 158
 159         if (udev->dev) {
 160                 name = udev->dev->name;
 161                 phys = udev->dev->phys;
 162                 if (udev->state == UIST_CREATED)
 163                         input_unregister_device(udev->dev);
 164                 else
 165                         input_free_device(udev->dev);
 166                 kfree(name);
 167                 kfree(phys);
 168                 udev->dev = NULL;
 169         }
 170
 171         udev->state = UIST_NEW_DEVICE;
 172 }
 173
 174 static int uinput_create_device(struct uinput_device *udev)
 175 {
 176         int error;
 177
 178         if (udev->state != UIST_SETUP_COMPLETE) {
 179                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 180                 return -EINVAL;
 181         }
 182
 183         error = input_register_device(udev->dev);
 184         if (error) {
 185                 uinput_destroy_device(udev);
 186                 return error;
 187         }
 188
 189         udev->state = UIST_CREATED;
 190
 191         return 0;
 192 }
 193
 194 static int uinput_open(struct inode *inode, struct file *file)
 195 {
 196         struct uinput_device *newdev;
 197
 198         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 199         if (!newdev)
 200                 return -ENOMEM;
 201
 202         init_MUTEX(&newdev->sem);
 203         spin_lock_init(&newdev->requests_lock);
 204         init_waitqueue_head(&newdev->requests_waitq);
 205         init_waitqueue_head(&newdev->waitq);
 206         newdev->state = UIST_NEW_DEVICE;
 207
 208         file->private_data = newdev;
 209
 210         return 0;
 211 }
 212
 213 static int uinput_validate_absbits(struct input_dev *dev)
 214 {
 215         unsigned int cnt;
 216         int retval = 0;
 217
 218         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 219                 if (!test_bit(cnt, dev->absbit))
 220                         continue;
 221
 222                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 223                         printk(KERN_DEBUG
 224                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 225                                 UINPUT_NAME, cnt,
 226                                 dev->absmin[cnt], dev->absmax[cnt]);
 227                         retval = -EINVAL;
 228                         break;
 229                 }
 230
 231                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 232                         printk(KERN_DEBUG
 233                                 "%s: absflat[%02x] out of range: %d "
 234                                 "(min:%d/max:%d)\n",
 235                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 236                                 dev->absmin[cnt], dev->absmax[cnt]);
 237                         retval = -EINVAL;
 238                         break;
 239                 }
 240         }
 241         return retval;
 242 }
 243
 244 static int uinput_allocate_device(struct uinput_device *udev)
 245 {
 246         udev->dev = input_allocate_device();
 247         if (!udev->dev)
 248                 return -ENOMEM;
 249
 250         udev->dev->event = uinput_dev_event;
 251         udev->dev->upload_effect = uinput_dev_upload_effect;
 252         udev->dev->erase_effect = uinput_dev_erase_effect;
 253         udev->dev->private = udev;
 254
 255         return 0;
 256 }
 257
 258 static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 259 {
 260         struct uinput_user_dev  *user_dev;
 261         struct input_dev        *dev;
 262         char                    *name;
 263         int                     size;
 264         int                     retval;
 265
 266         if (count != sizeof(struct uinput_user_dev))
 267                 return -EINVAL;
 268
 269         if (!udev->dev) {
 270                 retval = uinput_allocate_device(udev);
 271                 if (retval)
 272                         return retval;
 273         }
 274
 275         dev = udev->dev;
 276
 277         user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 278         if (!user_dev)
 279                 return -ENOMEM;
 280
 281         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 282                 retval = -EFAULT;
 283                 goto exit;
 284         }
 285
 286         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 287         if (!size) {
 288                 retval = -EINVAL;
 289                 goto exit;
 290         }
 291
 292         kfree(dev->name);
 293         dev->name = name = kmalloc(size, GFP_KERNEL);
 294         if (!name) {
 295                 retval = -ENOMEM;
 296                 goto exit;
 297         }
 298         strlcpy(name, user_dev->name, size);
 299
 300         dev->id.bustype = user_dev->id.bustype;
 301         dev->id.vendor  = user_dev->id.vendor;
 302         dev->id.product = user_dev->id.product;
 303         dev->id.version = user_dev->id.version;
 304         dev->ff_effects_max = user_dev->ff_effects_max;
 305
 306         size = sizeof(int) * (ABS_MAX + 1);
 307         memcpy(dev->absmax, user_dev->absmax, size);
 308         memcpy(dev->absmin, user_dev->absmin, size);
 309         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 310         memcpy(dev->absflat, user_dev->absflat, size);
 311
 312         /* check if absmin/absmax/absfuzz/absflat are filled as
 313          * told in Documentation/input/input-programming.txt */
 314         if (test_bit(EV_ABS, dev->evbit)) {
 315                 retval = uinput_validate_absbits(dev);
 316                 if (retval < 0)
 317                         goto exit;
 318         }
 319
 320         udev->state = UIST_SETUP_COMPLETE;
 321         retval = count;
 322
 323  exit:
 324         kfree(user_dev);
 325         return retval;
 326 }
 327
 328 static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 329 {
 330         struct input_event ev;
 331
 332         if (count != sizeof(struct input_event))
 333                 return -EINVAL;
 334
 335         if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 336                 return -EFAULT;
 337
 338         input_event(udev->dev, ev.type, ev.code, ev.value);
 339
 340         return sizeof(struct input_event);
 341 }
 342
 343 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 344 {
 345         struct uinput_device *udev = file->private_data;
 346         int retval;
 347
 348         retval = down_interruptible(&udev->sem);
 349         if (retval)
 350                 return retval;
 351
 352         retval = udev->state == UIST_CREATED ?
 353                         uinput_inject_event(udev, buffer, count) :
 354                         uinput_setup_device(udev, buffer, count);
 355
 356         up(&udev->sem);
 357
 358         return retval;
 359 }
 360
 361 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 362 {
 363         struct uinput_device *udev = file->private_data;
 364         int retval = 0;
 365
 366         if (udev->state != UIST_CREATED)
 367                 return -ENODEV;
 368
 369         if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 370                 return -EAGAIN;
 371
 372         retval = wait_event_interruptible(udev->waitq,
 373                         udev->head != udev->tail || udev->state != UIST_CREATED);
 374         if (retval)
 375                 return retval;
 376
 377         retval = down_interruptible(&udev->sem);
 378         if (retval)
 379                 return retval;
 380
 381         if (udev->state != UIST_CREATED) {
 382                 retval = -ENODEV;
 383                 goto out;
 384         }
 385
 386         while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 387                 if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 388                         retval = -EFAULT;
 389                         goto out;
 390                 }
 391                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 392                 retval += sizeof(struct input_event);
 393         }
 394
 395  out:
 396         up(&udev->sem);
 397
 398         return retval;
 399 }
 400
 401 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 402 {
 403         struct uinput_device *udev = file->private_data;
 404
 405         poll_wait(file, &udev->waitq, wait);
 406
 407         if (udev->head != udev->tail)
 408                 return POLLIN | POLLRDNORM;
 409
 410         return 0;
 411 }
 412
 413 static int uinput_release(struct inode *inode, struct file *file)
 414 {
 415         struct uinput_device *udev = file->private_data;
 416
 417         uinput_destroy_device(udev);
 418         kfree(udev);
 419
 420         return 0;
 421 }
 422
 423 #define uinput_set_bit(_arg, _bit, _max)                \
 424 ({                                                      \
 425         int __ret = 0;                                  \
 426         if (udev->state == UIST_CREATED)                \
 427                 __ret =  -EINVAL;                       \
 428         else if ((_arg) > (_max))                       \
 429                 __ret = -EINVAL;                        \
 430         else set_bit((_arg), udev->dev->_bit);          \
 431         __ret;                                          \
 432 })
 433
 434 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 435 {
 436         int                     retval;
 437         struct uinput_device    *udev;
 438         void __user             *p = (void __user *)arg;
 439         struct uinput_ff_upload ff_up;
 440         struct uinput_ff_erase  ff_erase;
 441         struct uinput_request   *req;
 442         int                     length;
 443         char                    *phys;
 444
 445         udev = file->private_data;
 446
 447         retval = down_interruptible(&udev->sem);
 448         if (retval)
 449                 return retval;
 450
 451         if (!udev->dev) {
 452                 retval = uinput_allocate_device(udev);
 453                 if (retval)
 454                         goto out;
 455         }
 456
 457         switch (cmd) {
 458                 case UI_DEV_CREATE:
 459                         retval = uinput_create_device(udev);
 460                         break;
 461
 462                 case UI_DEV_DESTROY:
 463                         uinput_destroy_device(udev);
 464                         break;
 465
 466                 case UI_SET_EVBIT:
 467                         retval = uinput_set_bit(arg, evbit, EV_MAX);
 468                         break;
 469
 470                 case UI_SET_KEYBIT:
 471                         retval = uinput_set_bit(arg, keybit, KEY_MAX);
 472                         break;
 473
 474                 case UI_SET_RELBIT:
 475                         retval = uinput_set_bit(arg, relbit, REL_MAX);
 476                         break;
 477
 478                 case UI_SET_ABSBIT:
 479                         retval = uinput_set_bit(arg, absbit, ABS_MAX);
 480                         break;
 481
 482                 case UI_SET_MSCBIT:
 483                         retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 484                         break;
 485
 486                 case UI_SET_LEDBIT:
 487                         retval = uinput_set_bit(arg, ledbit, LED_MAX);
 488                         break;
 489
 490                 case UI_SET_SNDBIT:
 491                         retval = uinput_set_bit(arg, sndbit, SND_MAX);
 492                         break;
 493
 494                 case UI_SET_FFBIT:
 495                         retval = uinput_set_bit(arg, ffbit, FF_MAX);
 496                         break;
 497
 498                 case UI_SET_PHYS:
 499                         if (udev->state == UIST_CREATED) {
 500                                 retval = -EINVAL;
 501                                 goto out;
 502                         }
 503                         length = strnlen_user(p, 1024);
 504                         if (length <= 0) {
 505                                 retval = -EFAULT;
 506                                 break;
 507                         }
 508                         kfree(udev->dev->phys);
 509                         udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 510                         if (!phys) {
 511                                 retval = -ENOMEM;
 512                                 break;
 513                         }
 514                         if (copy_from_user(phys, p, length)) {
 515                                 udev->dev->phys = NULL;
 516                                 kfree(phys);
 517                                 retval = -EFAULT;
 518                                 break;
 519                         }
 520                         phys[length - 1] = '\0';
 521                         break;
 522
 523                 case UI_BEGIN_FF_UPLOAD:
 524                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 525                                 retval = -EFAULT;
 526                                 break;
 527                         }
 528                         req = uinput_request_find(udev, ff_up.request_id);
 529                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 530                                 retval = -EINVAL;
 531                                 break;
 532                         }
 533                         ff_up.retval = 0;
 534                         memcpy(&ff_up.effect, req->u.effect, sizeof(struct ff_effect));
 535                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 536                                 retval = -EFAULT;
 537                                 break;
 538                         }
 539                         break;
 540
 541                 case UI_BEGIN_FF_ERASE:
 542                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 543                                 retval = -EFAULT;
 544                                 break;
 545                         }
 546                         req = uinput_request_find(udev, ff_erase.request_id);
 547                         if (!(req && req->code == UI_FF_ERASE)) {
 548                                 retval = -EINVAL;
 549                                 break;
 550                         }
 551                         ff_erase.retval = 0;
 552                         ff_erase.effect_id = req->u.effect_id;
 553                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 554                                 retval = -EFAULT;
 555                                 break;
 556                         }
 557                         break;
 558
 559                 case UI_END_FF_UPLOAD:
 560                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 561                                 retval = -EFAULT;
 562                                 break;
 563                         }
 564                         req = uinput_request_find(udev, ff_up.request_id);
 565                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 566                                 retval = -EINVAL;
 567                                 break;
 568                         }
 569                         req->retval = ff_up.retval;
 570                         memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
 571                         uinput_request_done(udev, req);
 572                         break;
 573
 574                 case UI_END_FF_ERASE:
 575                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 576                                 retval = -EFAULT;
 577                                 break;
 578                         }
 579                         req = uinput_request_find(udev, ff_erase.request_id);
 580                         if (!(req && req->code == UI_FF_ERASE)) {
 581                                 retval = -EINVAL;
 582                                 break;
 583                         }
 584                         req->retval = ff_erase.retval;
 585                         uinput_request_done(udev, req);
 586                         break;
 587
 588                 default:
 589                         retval = -EINVAL;
 590         }
 591
 592  out:
 593         up(&udev->sem);
 594         return retval;
 595 }
 596
 597 static struct file_operations uinput_fops = {
 598         .owner          = THIS_MODULE,
 599         .open           = uinput_open,
 600         .release        = uinput_release,
 601         .read           = uinput_read,
 602         .write          = uinput_write,
 603         .poll           = uinput_poll,
 604         .unlocked_ioctl = uinput_ioctl,
 605 };
 606
 607 static struct miscdevice uinput_misc = {
 608         .fops           = &uinput_fops,
 609         .minor          = UINPUT_MINOR,
 610         .name           = UINPUT_NAME,
 611 };
 612
 613 static int __init uinput_init(void)
 614 {
 615         return misc_register(&uinput_misc);
 616 }
 617
 618 static void __exit uinput_exit(void)
 619 {
 620         misc_deregister(&uinput_misc);
 621 }
 622
 623 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 624 MODULE_DESCRIPTION("User level driver support for input subsystem");
 625 MODULE_LICENSE("GPL");
 626
 627 module_init(uinput_init);
 628 module_exit(uinput_exit);
 629