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(&udev->requests_waitq);
  96
  97         complete(&request->done);
  98 }
  99
 100 static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 101 {
 102         /* Tell our userspace app about this new request by queueing an input event */
 103         uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 104
 105         /* Wait for the request to complete */
 106         wait_for_completion(&request->done);
 107         return request->retval;
 108 }
 109
 110 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
 111 {
 112         struct uinput_request request;
 113         int retval;
 114
 115         if (!test_bit(EV_FF, dev->evbit))
 116                 return -ENOSYS;
 117
 118         request.id = -1;
 119         init_completion(&request.done);
 120         request.code = UI_FF_UPLOAD;
 121         request.u.effect = effect;
 122
 123         retval = uinput_request_reserve_slot(dev->private, &request);
 124         if (!retval)
 125                 retval = uinput_request_submit(dev, &request);
 126
 127         return retval;
 128 }
 129
 130 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 131 {
 132         struct uinput_request request;
 133         int retval;
 134
 135         if (!test_bit(EV_FF, dev->evbit))
 136                 return -ENOSYS;
 137
 138         request.id = -1;
 139         init_completion(&request.done);
 140         request.code = UI_FF_ERASE;
 141         request.u.effect_id = effect_id;
 142
 143         retval = uinput_request_reserve_slot(dev->private, &request);
 144         if (!retval)
 145                 retval = uinput_request_submit(dev, &request);
 146
 147         return retval;
 148 }
 149
 150 static void uinput_destroy_device(struct uinput_device *udev)
 151 {
 152         const char *name, *phys;
 153
 154         if (udev->dev) {
 155                 name = udev->dev->name;
 156                 phys = udev->dev->phys;
 157                 if (udev->state == UIST_CREATED)
 158                         input_unregister_device(udev->dev);
 159                 else
 160                         input_free_device(udev->dev);
 161                 kfree(name);
 162                 kfree(phys);
 163                 udev->dev = NULL;
 164         }
 165
 166         udev->state = UIST_NEW_DEVICE;
 167 }
 168
 169 static int uinput_create_device(struct uinput_device *udev)
 170 {
 171         int error;
 172
 173         if (udev->state != UIST_SETUP_COMPLETE) {
 174                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 175                 return -EINVAL;
 176         }
 177
 178         error = input_register_device(udev->dev);
 179         if (error) {
 180                 uinput_destroy_device(udev);
 181                 return error;
 182         }
 183
 184         udev->state = UIST_CREATED;
 185
 186         return 0;
 187 }
 188
 189 static int uinput_open(struct inode *inode, struct file *file)
 190 {
 191         struct uinput_device *newdev;
 192
 193         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 194         if (!newdev)
 195                 return -ENOMEM;
 196
 197         mutex_init(&newdev->mutex);
 198         spin_lock_init(&newdev->requests_lock);
 199         init_waitqueue_head(&newdev->requests_waitq);
 200         init_waitqueue_head(&newdev->waitq);
 201         newdev->state = UIST_NEW_DEVICE;
 202
 203         file->private_data = newdev;
 204
 205         return 0;
 206 }
 207
 208 static int uinput_validate_absbits(struct input_dev *dev)
 209 {
 210         unsigned int cnt;
 211         int retval = 0;
 212
 213         for (cnt = 0; cnt < ABS_MAX + 1; cnt++) {
 214                 if (!test_bit(cnt, dev->absbit))
 215                         continue;
 216
 217                 if ((dev->absmax[cnt] <= dev->absmin[cnt])) {
 218                         printk(KERN_DEBUG
 219                                 "%s: invalid abs[%02x] min:%d max:%d\n",
 220                                 UINPUT_NAME, cnt,
 221                                 dev->absmin[cnt], dev->absmax[cnt]);
 222                         retval = -EINVAL;
 223                         break;
 224                 }
 225
 226                 if (dev->absflat[cnt] > (dev->absmax[cnt] - dev->absmin[cnt])) {
 227                         printk(KERN_DEBUG
 228                                 "%s: absflat[%02x] out of range: %d "
 229                                 "(min:%d/max:%d)\n",
 230                                 UINPUT_NAME, cnt, dev->absflat[cnt],
 231                                 dev->absmin[cnt], dev->absmax[cnt]);
 232                         retval = -EINVAL;
 233                         break;
 234                 }
 235         }
 236         return retval;
 237 }
 238
 239 static int uinput_allocate_device(struct uinput_device *udev)
 240 {
 241         udev->dev = input_allocate_device();
 242         if (!udev->dev)
 243                 return -ENOMEM;
 244
 245         udev->dev->event = uinput_dev_event;
 246         udev->dev->upload_effect = uinput_dev_upload_effect;
 247         udev->dev->erase_effect = uinput_dev_erase_effect;
 248         udev->dev->private = udev;
 249
 250         return 0;
 251 }
 252
 253 static int uinput_setup_device(struct uinput_device *udev, const char __user *buffer, size_t count)
 254 {
 255         struct uinput_user_dev  *user_dev;
 256         struct input_dev        *dev;
 257         char                    *name;
 258         int                     size;
 259         int                     retval;
 260
 261         if (count != sizeof(struct uinput_user_dev))
 262                 return -EINVAL;
 263
 264         if (!udev->dev) {
 265                 retval = uinput_allocate_device(udev);
 266                 if (retval)
 267                         return retval;
 268         }
 269
 270         dev = udev->dev;
 271
 272         user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL);
 273         if (!user_dev)
 274                 return -ENOMEM;
 275
 276         if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) {
 277                 retval = -EFAULT;
 278                 goto exit;
 279         }
 280
 281         size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1;
 282         if (!size) {
 283                 retval = -EINVAL;
 284                 goto exit;
 285         }
 286
 287         kfree(dev->name);
 288         dev->name = name = kmalloc(size, GFP_KERNEL);
 289         if (!name) {
 290                 retval = -ENOMEM;
 291                 goto exit;
 292         }
 293         strlcpy(name, user_dev->name, size);
 294
 295         dev->id.bustype = user_dev->id.bustype;
 296         dev->id.vendor  = user_dev->id.vendor;
 297         dev->id.product = user_dev->id.product;
 298         dev->id.version = user_dev->id.version;
 299         dev->ff_effects_max = user_dev->ff_effects_max;
 300
 301         size = sizeof(int) * (ABS_MAX + 1);
 302         memcpy(dev->absmax, user_dev->absmax, size);
 303         memcpy(dev->absmin, user_dev->absmin, size);
 304         memcpy(dev->absfuzz, user_dev->absfuzz, size);
 305         memcpy(dev->absflat, user_dev->absflat, size);
 306
 307         /* check if absmin/absmax/absfuzz/absflat are filled as
 308          * told in Documentation/input/input-programming.txt */
 309         if (test_bit(EV_ABS, dev->evbit)) {
 310                 retval = uinput_validate_absbits(dev);
 311                 if (retval < 0)
 312                         goto exit;
 313         }
 314
 315         udev->state = UIST_SETUP_COMPLETE;
 316         retval = count;
 317
 318  exit:
 319         kfree(user_dev);
 320         return retval;
 321 }
 322
 323 static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
 324 {
 325         struct input_event ev;
 326
 327         if (count != sizeof(struct input_event))
 328                 return -EINVAL;
 329
 330         if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
 331                 return -EFAULT;
 332
 333         input_event(udev->dev, ev.type, ev.code, ev.value);
 334
 335         return sizeof(struct input_event);
 336 }
 337
 338 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 339 {
 340         struct uinput_device *udev = file->private_data;
 341         int retval;
 342
 343         retval = mutex_lock_interruptible(&udev->mutex);
 344         if (retval)
 345                 return retval;
 346
 347         retval = udev->state == UIST_CREATED ?
 348                         uinput_inject_event(udev, buffer, count) :
 349                         uinput_setup_device(udev, buffer, count);
 350
 351         mutex_unlock(&udev->mutex);
 352
 353         return retval;
 354 }
 355
 356 static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 357 {
 358         struct uinput_device *udev = file->private_data;
 359         int retval = 0;
 360
 361         if (udev->state != UIST_CREATED)
 362                 return -ENODEV;
 363
 364         if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
 365                 return -EAGAIN;
 366
 367         retval = wait_event_interruptible(udev->waitq,
 368                         udev->head != udev->tail || udev->state != UIST_CREATED);
 369         if (retval)
 370                 return retval;
 371
 372         retval = mutex_lock_interruptible(&udev->mutex);
 373         if (retval)
 374                 return retval;
 375
 376         if (udev->state != UIST_CREATED) {
 377                 retval = -ENODEV;
 378                 goto out;
 379         }
 380
 381         while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
 382                 if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
 383                         retval = -EFAULT;
 384                         goto out;
 385                 }
 386                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 387                 retval += sizeof(struct input_event);
 388         }
 389
 390  out:
 391         mutex_unlock(&udev->mutex);
 392
 393         return retval;
 394 }
 395
 396 static unsigned int uinput_poll(struct file *file, poll_table *wait)
 397 {
 398         struct uinput_device *udev = file->private_data;
 399
 400         poll_wait(file, &udev->waitq, wait);
 401
 402         if (udev->head != udev->tail)
 403                 return POLLIN | POLLRDNORM;
 404
 405         return 0;
 406 }
 407
 408 static int uinput_release(struct inode *inode, struct file *file)
 409 {
 410         struct uinput_device *udev = file->private_data;
 411
 412         uinput_destroy_device(udev);
 413         kfree(udev);
 414
 415         return 0;
 416 }
 417
 418 #define uinput_set_bit(_arg, _bit, _max)                \
 419 ({                                                      \
 420         int __ret = 0;                                  \
 421         if (udev->state == UIST_CREATED)                \
 422                 __ret =  -EINVAL;                       \
 423         else if ((_arg) > (_max))                       \
 424                 __ret = -EINVAL;                        \
 425         else set_bit((_arg), udev->dev->_bit);          \
 426         __ret;                                          \
 427 })
 428
 429 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 430 {
 431         int                     retval;
 432         struct uinput_device    *udev;
 433         void __user             *p = (void __user *)arg;
 434         struct uinput_ff_upload ff_up;
 435         struct uinput_ff_erase  ff_erase;
 436         struct uinput_request   *req;
 437         int                     length;
 438         char                    *phys;
 439
 440         udev = file->private_data;
 441
 442         retval = mutex_lock_interruptible(&udev->mutex);
 443         if (retval)
 444                 return retval;
 445
 446         if (!udev->dev) {
 447                 retval = uinput_allocate_device(udev);
 448                 if (retval)
 449                         goto out;
 450         }
 451
 452         switch (cmd) {
 453                 case UI_DEV_CREATE:
 454                         retval = uinput_create_device(udev);
 455                         break;
 456
 457                 case UI_DEV_DESTROY:
 458                         uinput_destroy_device(udev);
 459                         break;
 460
 461                 case UI_SET_EVBIT:
 462                         retval = uinput_set_bit(arg, evbit, EV_MAX);
 463                         break;
 464
 465                 case UI_SET_KEYBIT:
 466                         retval = uinput_set_bit(arg, keybit, KEY_MAX);
 467                         break;
 468
 469                 case UI_SET_RELBIT:
 470                         retval = uinput_set_bit(arg, relbit, REL_MAX);
 471                         break;
 472
 473                 case UI_SET_ABSBIT:
 474                         retval = uinput_set_bit(arg, absbit, ABS_MAX);
 475                         break;
 476
 477                 case UI_SET_MSCBIT:
 478                         retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 479                         break;
 480
 481                 case UI_SET_LEDBIT:
 482                         retval = uinput_set_bit(arg, ledbit, LED_MAX);
 483                         break;
 484
 485                 case UI_SET_SNDBIT:
 486                         retval = uinput_set_bit(arg, sndbit, SND_MAX);
 487                         break;
 488
 489                 case UI_SET_FFBIT:
 490                         retval = uinput_set_bit(arg, ffbit, FF_MAX);
 491                         break;
 492
 493                 case UI_SET_SWBIT:
 494                         retval = uinput_set_bit(arg, swbit, SW_MAX);
 495                         break;
 496
 497                 case UI_SET_PHYS:
 498                         if (udev->state == UIST_CREATED) {
 499                                 retval = -EINVAL;
 500                                 goto out;
 501                         }
 502                         length = strnlen_user(p, 1024);
 503                         if (length <= 0) {
 504                                 retval = -EFAULT;
 505                                 break;
 506                         }
 507                         kfree(udev->dev->phys);
 508                         udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
 509                         if (!phys) {
 510                                 retval = -ENOMEM;
 511                                 break;
 512                         }
 513                         if (copy_from_user(phys, p, length)) {
 514                                 udev->dev->phys = NULL;
 515                                 kfree(phys);
 516                                 retval = -EFAULT;
 517                                 break;
 518                         }
 519                         phys[length - 1] = '\0';
 520                         break;
 521
 522                 case UI_BEGIN_FF_UPLOAD:
 523                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 524                                 retval = -EFAULT;
 525                                 break;
 526                         }
 527                         req = uinput_request_find(udev, ff_up.request_id);
 528                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 529                                 retval = -EINVAL;
 530                                 break;
 531                         }
 532                         ff_up.retval = 0;
 533                         memcpy(&ff_up.effect, req->u.effect, sizeof(struct ff_effect));
 534                         if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
 535                                 retval = -EFAULT;
 536                                 break;
 537                         }
 538                         break;
 539
 540                 case UI_BEGIN_FF_ERASE:
 541                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 542                                 retval = -EFAULT;
 543                                 break;
 544                         }
 545                         req = uinput_request_find(udev, ff_erase.request_id);
 546                         if (!(req && req->code == UI_FF_ERASE)) {
 547                                 retval = -EINVAL;
 548                                 break;
 549                         }
 550                         ff_erase.retval = 0;
 551                         ff_erase.effect_id = req->u.effect_id;
 552                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 553                                 retval = -EFAULT;
 554                                 break;
 555                         }
 556                         break;
 557
 558                 case UI_END_FF_UPLOAD:
 559                         if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
 560                                 retval = -EFAULT;
 561                                 break;
 562                         }
 563                         req = uinput_request_find(udev, ff_up.request_id);
 564                         if (!(req && req->code == UI_FF_UPLOAD && req->u.effect)) {
 565                                 retval = -EINVAL;
 566                                 break;
 567                         }
 568                         req->retval = ff_up.retval;
 569                         memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
 570                         uinput_request_done(udev, req);
 571                         break;
 572
 573                 case UI_END_FF_ERASE:
 574                         if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 575                                 retval = -EFAULT;
 576                                 break;
 577                         }
 578                         req = uinput_request_find(udev, ff_erase.request_id);
 579                         if (!(req && req->code == UI_FF_ERASE)) {
 580                                 retval = -EINVAL;
 581                                 break;
 582                         }
 583                         req->retval = ff_erase.retval;
 584                         uinput_request_done(udev, req);
 585                         break;
 586
 587                 default:
 588                         retval = -EINVAL;
 589         }
 590
 591  out:
 592         mutex_unlock(&udev->mutex);
 593         return retval;
 594 }
 595
 596 static struct file_operations uinput_fops = {
 597         .owner          = THIS_MODULE,
 598         .open           = uinput_open,
 599         .release        = uinput_release,
 600         .read           = uinput_read,
 601         .write          = uinput_write,
 602         .poll           = uinput_poll,
 603         .unlocked_ioctl = uinput_ioctl,
 604 };
 605
 606 static struct miscdevice uinput_misc = {
 607         .fops           = &uinput_fops,
 608         .minor          = UINPUT_MINOR,
 609         .name           = UINPUT_NAME,
 610 };
 611
 612 static int __init uinput_init(void)
 613 {
 614         return misc_register(&uinput_misc);
 615 }
 616
 617 static void __exit uinput_exit(void)
 618 {
 619         misc_deregister(&uinput_misc);
 620 }
 621
 622 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
 623 MODULE_DESCRIPTION("User level driver support for input subsystem");
 624 MODULE_LICENSE("GPL");
 625
 626 module_init(uinput_init);
 627 module_exit(uinput_exit);
 628