drivers/input/misc/uinput.c

   1 /*
   2  *  User level driver support for input subsystem
   3  *
   4  * Heavily based on evdev.c by Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  21  *
  22  * Changes/Revisions:
  23  *      0.3     09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
  24  *              - updated ff support for the changes in kernel interface
  25  *              - added MODULE_VERSION
  26  *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  27  *              - added force feedback support
  28  *              - added UI_SET_PHYS
  29  *      0.1     20/06/2002
  30  *              - first public version
  31  */
  32 #include <linux/poll.h>
  33 #include <linux/slab.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/input.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/fs.h>
  39 #include <linux/miscdevice.h>
  40 #include <linux/uinput.h>
  41
  42 static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
  43 {
  44         struct uinput_device    *udev;
  45
  46         udev = dev->private;
  47
  48         udev->buff[udev->head].type = type;
  49         udev->buff[udev->head].code = code;
  50         udev->buff[udev->head].value = value;
  51         do_gettimeofday(&udev->buff[udev->head].time);
  52         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  53
  54         wake_up_interruptible(&udev->waitq);
  55
  56         return 0;
  57 }
  58
  59 static int uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request)
  60 {
  61         /* Atomically allocate an ID for the given request. Returns 0 on success. */
  62         int id;
  63         int err = -1;
  64
  65         spin_lock(&udev->requests_lock);
  66
  67         for (id = 0; id < UINPUT_NUM_REQUESTS; id++)
  68                 if (!udev->requests[id]) {
  69                         request->id = id;
  70                         udev->requests[id] = request;
  71                         err = 0;
  72                         break;
  73                 }
  74
  75         spin_unlock(&udev->requests_lock);
  76         return err;
  77 }
  78
  79 static struct uinput_request* uinput_request_find(struct uinput_device *udev, int id)
  80 {
  81         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
  82         if (id >= UINPUT_NUM_REQUESTS || id < 0)
  83                 return NULL;
  84         return udev->requests[id];
  85 }
  86
  87 static inline int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request)
  88 {
  89         /* Allocate slot. If none are available right away, wait. */
  90         return wait_event_interruptible(udev->requests_waitq,
  91                                         !uinput_request_alloc_id(udev, request));
  92 }
  93
  94 static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request)
  95 {
  96         /* Mark slot as available */
  97         udev->requests[request->id] = NULL;
  98         wake_up(&udev->requests_waitq);
  99
 100         complete(&request->done);
 101 }
 102
 103 static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 104 {
 105         /* Tell our userspace app about this new request by queueing an input event */
 106         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 107
 108         /* Wait for the request to complete */
 109         wait_for_completion(&request->done);
 110         return request->retval;
 111 }
 112
 113 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 114 {
 115         uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 116 }
 117
 118 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 119 {
 120         uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 121 }
 122
 123 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
 124 {
 125         return uinput_dev_event(dev, EV_FF, effect_id, value);
 126 }
 127
 128 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
 129 {
 130         struct uinput_request request;
 131         int retval;
 132
 133         request.id = -1;
 134         init_completion(&request.done);
 135         request.code = UI_FF_UPLOAD;
 136         request.u.upload.effect = effect;
 137         request.u.upload.old = old;
 138
 139         retval = uinput_request_reserve_slot(dev->private, &request);
 140         if (!retval)
 141                 retval = uinput_request_submit(dev, &request);
 142
 143         return retval;
 144 }
 145
 146 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 147 {
 148         struct uinput_request request;
 149         int retval;
 150
 151         if (!test_bit(EV_FF, dev->evbit))
 152                 return -ENOSYS;
 153
 154         request.id = -1;
 155         init_completion(&request.done);
 156         request.code = UI_FF_ERASE;
 157         request.u.effect_id = effect_id;
 158
 159         retval = uinput_request_reserve_slot(dev->private, &request);
 160         if (!retval)
 161                 retval = uinput_request_submit(dev, &request);
 162
 163         return retval;
 164 }
 165
 166 static void uinput_destroy_device(struct uinput_device *udev)
 167 {
 168         const char *name, *phys;
 169
 170         if (udev->dev) {
 171                 name = udev->dev->name;
 172                 phys = udev->dev->phys;
 173                 if (udev->state == UIST_CREATED)
 174                         input_unregister_device(udev->dev);
 175                 else
 176                         input_free_device(udev->dev);
 177                 kfree(name);
 178                 kfree(phys);
 179                 udev->dev = NULL;
 180         }
 181
 182         udev->state = UIST_NEW_DEVICE;
 183 }
 184
 185 static int uinput_create_device(struct uinput_device *udev)
 186 {
 187         struct input_dev *dev = udev->dev;
 188         int error;
 189
 190         if (udev->state != UIST_SETUP_COMPLETE) {
 191                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 192                 return -EINVAL;
 193         }
 194
 195         if (udev->ff_effects_max) {
 196                 error = input_ff_create(dev, udev->ff_effects_max);
 197                 if (error)
 198                         goto fail1;
 199
 200                 dev->ff->upload = uinput_dev_upload_effect;
 201                 dev->ff->erase = uinput_dev_erase_effect;
 202                 dev->ff->playback = uinput_dev_playback;
 203                 dev->ff->set_gain = uinput_dev_set_gain;
 204                 dev->ff->set_autocenter = uinput_dev_set_autocenter;
 205         }
 206
 207         error = input_register_device(udev->dev);
 208         if (error)
 209                 goto fail2;
 210
 211         udev->state = UIST_CREATED;
 212
 213         return 0;
 214
 215  fail2: input_ff_destroy(dev);
 216  fail1: uinput_destroy_device(udev);
 217         return error;
 218 }
 219
 220 static int uinput_open(struct inode *inode, struct file *file)
 221 {
 222         struct uinput_device *newdev;
 223
 224         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 225         if (!newdev)
 226                 return -ENOMEM;
 227
 228         mutex_init(&newdev->mutex);
 229         spin_lock_init(&newdev->requests_lock);
 230         init_waitqueue_head(&newdev->requests_waitq);
 231         init_waitqueue_head(&newdev->waitq);
 232         newdev->state = UIST_NEW_DEVICE;
 233
 234         file->private_data = newdev;
 235
 236         return 0;
 237 }
 238
 239 static int uinput_validate_absbits(struct input_dev *dev)
 240 {
 241         unsigned int cnt;
 242         int retval = 0;
 243
 244         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 245                 if (!test_bit(cnt, dev->absbit))
 246                         continue;
 247
 248                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 249                         printk(KERN_DEBUG
 250                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 251                                 UINPUT_NAME, cnt,
 252                                 dev->absmin[cnt], dev->absmax[cnt]);
 253                         retval = -EINVAL;
 254                         break;
 255                 }
 256
 257                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 258                         printk(KERN_DEBUG
 259                                 "%s: absflat[%02x] out of range: %d "
 260                                 "(min:%d/max:%d)\n",
 261                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 262                                 dev->absmin[cnt], dev->absmax[cnt]);
 263                         retval = -EINVAL;
 264                         break;
 265                 }
 266         }
 267         return retval;
 268 }
 269
 270 static int uinput_allocate_device(struct uinput_device *udev)
 271 {
 272         udev->dev = input_allocate_device();
 273         if (!udev->dev)
 274                 return -ENOMEM;
 275
 276         udev->dev->event = uinput_dev_event;
 277         udev->dev->private = udev;
 278
 279         return 0;
 280 }
 281
 282 static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 283 {
 284         struct uinput_user_dev  *user_dev;
 285         struct input_dev        *dev;
 286         char                    *name;
 287         int                     size;
 288         int                     retval;
 289
 290         if (count != sizeof(struct uinput_user_dev))
 291                 return -EINVAL;
 292
 293         if (!udev->dev) {
 294                 retval = uinput_allocate_device(udev);
 295                 if (retval)
 296                         return retval;
 297         }
 298
 299         dev = udev->dev;
 300
 301         user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 302         if (!user_dev)
 303                 return -ENOMEM;
 304
 305         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 306                 retval = -EFAULT;
 307                 goto exit;
 308         }
 309
 310         udev->ff_effects_max = user_dev->ff_effects_max;
 311
 312         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 313         if (!size) {
 314                 retval = -EINVAL;
 315                 goto exit;
 316         }
 317
 318         kfree(dev->name);
 319         dev->name = name = kmalloc(size, GFP_KERNEL);
 320         if (!name) {
 321                 retval = -ENOMEM;
 322                 goto exit;
 323         }
 324         strlcpy(name, user_dev->name, size);
 325
 326         dev->id.bustype = user_dev->id.bustype;
 327         dev->id.vendor  = user_dev->id.vendor;
 328         dev->id.product = user_dev->id.product;
 329         dev->id.version = user_dev->id.version;
 330
 331         size = sizeof(int) * (ABS_MAX + 1);
 332         memcpy(dev->absmax, user_dev->absmax, size);
 333         memcpy(dev->absmin, user_dev->absmin, size);
 334         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 335         memcpy(dev->absflat, user_dev->absflat, size);
 336
 337         /* check if absmin/absmax/absfuzz/absflat are filled as
 338          * told in Documentation/input/input-programming.txt */
 339         if (test_bit(EV_ABS, dev->evbit)) {
 340                 retval = uinput_validate_absbits(dev);
 341                 if (retval < 0)
 342                         goto exit;
 343         }
 344
 345         udev->state = UIST_SETUP_COMPLETE;
 346         retval = count;
 347
 348  exit:
 349         kfree(user_dev);
 350         return retval;
 351 }
 352
 353 static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 354 {
 355         struct input_event ev;
 356
 357         if (count != sizeof(struct input_event))
 358                 return -EINVAL;
 359
 360         if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 361                 return -EFAULT;
 362
 363         input_event(udev->dev, ev.type, ev.code, ev.value);
 364
 365         return sizeof(struct input_event);
 366 }
 367
 368 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 369 {
 370         struct uinput_device *udev = file->private_data;
 371         int retval;
 372
 373         retval = mutex_lock_interruptible(&udev->mutex);
 374         if (retval)
 375                 return retval;
 376
 377         retval = udev->state == UIST_CREATED ?
 378                         uinput_inject_event(udev, buffer, count) :
 379                         uinput_setup_device(udev, buffer, count);
 380
 381         mutex_unlock(&udev->mutex);
 382
 383         return retval;
 384 }
 385
 386 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 387 {
 388         struct uinput_device *udev = file->private_data;
 389         int retval = 0;
 390
 391         if (udev->state != UIST_CREATED)
 392                 return -ENODEV;
 393
 394         if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 395                 return -EAGAIN;
 396
 397         retval = wait_event_interruptible(udev->waitq,
 398                         udev->head != udev->tail || udev->state != UIST_CREATED);
 399         if (retval)
 400                 return retval;
 401
 402         retval = mutex_lock_interruptible(&udev->mutex);
 403         if (retval)
 404                 return retval;
 405
 406         if (udev->state != UIST_CREATED) {
 407                 retval = -ENODEV;
 408                 goto out;
 409         }
 410
 411         while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 412                 if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 413                         retval = -EFAULT;
 414                         goto out;
 415                 }
 416                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 417                 retval += sizeof(struct input_event);
 418         }
 419
 420  out:
 421         mutex_unlock(&udev->mutex);
 422
 423         return retval;
 424 }
 425
 426 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 427 {
 428         struct uinput_device *udev = file->private_data;
 429
 430         poll_wait(file, &udev->waitq, wait);
 431
 432         if (udev->head != udev->tail)
 433                 return POLLIN | POLLRDNORM;
 434
 435         return 0;
 436 }
 437
 438 static int uinput_release(struct inode *inode, struct file *file)
 439 {
 440         struct uinput_device *udev = file->private_data;
 441
 442         uinput_destroy_device(udev);
 443         kfree(udev);
 444
 445         return 0;
 446 }
 447
 448 #define uinput_set_bit(_arg, _bit, _max)                \
 449 ({                                                      \
 450         int __ret = 0;                                  \
 451         if (udev->state == UIST_CREATED)                \
 452                 __ret =  -EINVAL;                       \
 453         else if ((_arg) > (_max))                       \
 454                 __ret = -EINVAL;                        \
 455         else set_bit((_arg), udev->dev->_bit);          \
 456         __ret;                                          \
 457 })
 458
 459 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 460 {
 461         int                     retval;
 462         struct uinput_device    *udev;
 463         void __user             *p = (void __user *)arg;
 464         struct uinput_ff_upload ff_up;
 465         struct uinput_ff_erase  ff_erase;
 466         struct uinput_request   *req;
 467         int                     length;
 468         char                    *phys;
 469
 470         udev = file->private_data;
 471
 472         retval = mutex_lock_interruptible(&udev->mutex);
 473         if (retval)
 474                 return retval;
 475
 476         if (!udev->dev) {
 477                 retval = uinput_allocate_device(udev);
 478                 if (retval)
 479                         goto out;
 480         }
 481
 482         switch (cmd) {
 483                 case UI_DEV_CREATE:
 484                         retval = uinput_create_device(udev);
 485                         break;
 486
 487                 case UI_DEV_DESTROY:
 488                         uinput_destroy_device(udev);
 489                         break;
 490
 491                 case UI_SET_EVBIT:
 492                         retval = uinput_set_bit(arg, evbit, EV_MAX);
 493                         break;
 494
 495                 case UI_SET_KEYBIT:
 496                         retval = uinput_set_bit(arg, keybit, KEY_MAX);
 497                         break;
 498
 499                 case UI_SET_RELBIT:
 500                         retval = uinput_set_bit(arg, relbit, REL_MAX);
 501                         break;
 502
 503                 case UI_SET_ABSBIT:
 504                         retval = uinput_set_bit(arg, absbit, ABS_MAX);
 505                         break;
 506
 507                 case UI_SET_MSCBIT:
 508                         retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 509                         break;
 510
 511                 case UI_SET_LEDBIT:
 512                         retval = uinput_set_bit(arg, ledbit, LED_MAX);
 513                         break;
 514
 515                 case UI_SET_SNDBIT:
 516                         retval = uinput_set_bit(arg, sndbit, SND_MAX);
 517                         break;
 518
 519                 case UI_SET_FFBIT:
 520                         retval = uinput_set_bit(arg, ffbit, FF_MAX);
 521                         break;
 522
 523                 case UI_SET_SWBIT:
 524                         retval = uinput_set_bit(arg, swbit, SW_MAX);
 525                         break;
 526
 527                 case UI_SET_PHYS:
 528                         if (udev->state == UIST_CREATED) {
 529                                 retval = -EINVAL;
 530                                 goto out;
 531                         }
 532                         length = strnlen_user(p, 1024);
 533                         if (length <= 0) {
 534                                 retval = -EFAULT;
 535                                 break;
 536                         }
 537                         kfree(udev->dev->phys);
 538                         udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 539                         if (!phys) {
 540                                 retval = -ENOMEM;
 541                                 break;
 542                         }
 543                         if (copy_from_user(phys, p, length)) {
 544                                 udev->dev->phys = NULL;
 545                                 kfree(phys);
 546                                 retval = -EFAULT;
 547                                 break;
 548                         }
 549                         phys[length - 1] = '\0';
 550                         break;
 551
 552                 case UI_BEGIN_FF_UPLOAD:
 553                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 554                                 retval = -EFAULT;
 555                                 break;
 556                         }
 557                         req = uinput_request_find(udev, ff_up.request_id);
 558                         if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 559                                 retval = -EINVAL;
 560                                 break;
 561                         }
 562                         ff_up.retval = 0;
 563                         memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
 564                         if (req->u.upload.old)
 565                                 memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
 566                         else
 567                                 memset(&ff_up.old, 0, sizeof(struct ff_effect));
 568
 569                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 570                                 retval = -EFAULT;
 571                                 break;
 572                         }
 573                         break;
 574
 575                 case UI_BEGIN_FF_ERASE:
 576                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 577                                 retval = -EFAULT;
 578                                 break;
 579                         }
 580                         req = uinput_request_find(udev, ff_erase.request_id);
 581                         if (!(req && req->code == UI_FF_ERASE)) {
 582                                 retval = -EINVAL;
 583                                 break;
 584                         }
 585                         ff_erase.retval = 0;
 586                         ff_erase.effect_id = req->u.effect_id;
 587                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 588                                 retval = -EFAULT;
 589                                 break;
 590                         }
 591                         break;
 592
 593                 case UI_END_FF_UPLOAD:
 594                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 595                                 retval = -EFAULT;
 596                                 break;
 597                         }
 598                         req = uinput_request_find(udev, ff_up.request_id);
 599                         if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
 600                                 retval = -EINVAL;
 601                                 break;
 602                         }
 603                         req->retval = ff_up.retval;
 604                         uinput_request_done(udev, req);
 605                         break;
 606
 607                 case UI_END_FF_ERASE:
 608                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 609                                 retval = -EFAULT;
 610                                 break;
 611                         }
 612                         req = uinput_request_find(udev, ff_erase.request_id);
 613                         if (!(req && req->code == UI_FF_ERASE)) {
 614                                 retval = -EINVAL;
 615                                 break;
 616                         }
 617                         req->retval = ff_erase.retval;
 618                         uinput_request_done(udev, req);
 619                         break;
 620
 621                 default:
 622                         retval = -EINVAL;
 623         }
 624
 625  out:
 626         mutex_unlock(&udev->mutex);
 627         return retval;
 628 }
 629
 630 static const struct file_operations uinput_fops = {
 631         .owner          = THIS_MODULE,
 632         .open           = uinput_open,
 633         .release        = uinput_release,
 634         .read           = uinput_read,
 635         .write          = uinput_write,
 636         .poll           = uinput_poll,
 637         .unlocked_ioctl = uinput_ioctl,
 638 };
 639
 640 static struct miscdevice uinput_misc = {
 641         .fops           = &uinput_fops,
 642         .minor          = UINPUT_MINOR,
 643         .name           = UINPUT_NAME,
 644 };
 645
 646 static int __init uinput_init(void)
 647 {
 648         return misc_register(&uinput_misc);
 649 }
 650
 651 static void __exit uinput_exit(void)
 652 {
 653         misc_deregister(&uinput_misc);
 654 }
 655
 656 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 657 MODULE_DESCRIPTION("User level driver support for input subsystem");
 658 MODULE_LICENSE("GPL");
 659 MODULE_VERSION("0.3");
 660
 661 module_init(uinput_init);
 662 module_exit(uinput_exit);
 663