1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * User level driver support for input subsystem 4 * 5 * Heavily based on evdev.c by Vojtech Pavlik 6 * 7 * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> 8 * 9 * Changes/Revisions: 10 * 0.4 01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>) 11 * - add UI_GET_SYSNAME ioctl 12 * 0.3 09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>) 13 * - updated ff support for the changes in kernel interface 14 * - added MODULE_VERSION 15 * 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>) 16 * - added force feedback support 17 * - added UI_SET_PHYS 18 * 0.1 20/06/2002 19 * - first public version 20 */ 21 #include <uapi/linux/uinput.h> 22 #include <linux/poll.h> 23 #include <linux/sched.h> 24 #include <linux/slab.h> 25 #include <linux/module.h> 26 #include <linux/init.h> 27 #include <linux/fs.h> 28 #include <linux/miscdevice.h> 29 #include <linux/overflow.h> 30 #include <linux/input/mt.h> 31 #include "../input-compat.h" 32 33 #define UINPUT_NAME "uinput" 34 #define UINPUT_BUFFER_SIZE 16 35 #define UINPUT_NUM_REQUESTS 16 36 #define UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS 10 37 38 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED }; 39 40 struct uinput_request { 41 unsigned int id; 42 unsigned int code; /* UI_FF_UPLOAD, UI_FF_ERASE */ 43 44 int retval; 45 struct completion done; 46 47 union { 48 unsigned int effect_id; 49 struct { 50 struct ff_effect *effect; 51 struct ff_effect *old; 52 } upload; 53 } u; 54 }; 55 56 struct uinput_device { 57 struct input_dev *dev; 58 struct mutex mutex; 59 enum uinput_state state; 60 wait_queue_head_t waitq; 61 unsigned char ready; 62 unsigned char head; 63 unsigned char tail; 64 struct input_event buff[UINPUT_BUFFER_SIZE]; 65 unsigned int ff_effects_max; 66 67 struct uinput_request *requests[UINPUT_NUM_REQUESTS]; 68 wait_queue_head_t requests_waitq; 69 spinlock_t requests_lock; 70 }; 71 72 static int uinput_dev_event(struct input_dev *dev, 73 unsigned int type, unsigned int code, int value) 74 { 75 struct uinput_device *udev = input_get_drvdata(dev); 76 struct timespec64 ts; 77 78 ktime_get_ts64(&ts); 79 80 udev->buff[udev->head] = (struct input_event) { 81 .input_event_sec = ts.tv_sec, 82 .input_event_usec = ts.tv_nsec / NSEC_PER_USEC, 83 .type = type, 84 .code = code, 85 .value = value, 86 }; 87 88 udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE; 89 90 wake_up_interruptible(&udev->waitq); 91 92 return 0; 93 } 94 95 /* Atomically allocate an ID for the given request. Returns 0 on success. */ 96 static bool uinput_request_alloc_id(struct uinput_device *udev, 97 struct uinput_request *request) 98 { 99 unsigned int id; 100 bool reserved = false; 101 102 spin_lock(&udev->requests_lock); 103 104 for (id = 0; id < UINPUT_NUM_REQUESTS; id++) { 105 if (!udev->requests[id]) { 106 request->id = id; 107 udev->requests[id] = request; 108 reserved = true; 109 break; 110 } 111 } 112 113 spin_unlock(&udev->requests_lock); 114 return reserved; 115 } 116 117 static struct uinput_request *uinput_request_find(struct uinput_device *udev, 118 unsigned int id) 119 { 120 /* Find an input request, by ID. Returns NULL if the ID isn't valid. */ 121 if (id >= UINPUT_NUM_REQUESTS) 122 return NULL; 123 124 return udev->requests[id]; 125 } 126 127 static int uinput_request_reserve_slot(struct uinput_device *udev, 128 struct uinput_request *request) 129 { 130 /* Allocate slot. If none are available right away, wait. */ 131 return wait_event_interruptible(udev->requests_waitq, 132 uinput_request_alloc_id(udev, request)); 133 } 134 135 static void uinput_request_release_slot(struct uinput_device *udev, 136 unsigned int id) 137 { 138 /* Mark slot as available */ 139 spin_lock(&udev->requests_lock); 140 udev->requests[id] = NULL; 141 spin_unlock(&udev->requests_lock); 142 143 wake_up(&udev->requests_waitq); 144 } 145 146 static int uinput_request_send(struct uinput_device *udev, 147 struct uinput_request *request) 148 { 149 int retval; 150 151 retval = mutex_lock_interruptible(&udev->mutex); 152 if (retval) 153 return retval; 154 155 if (udev->state != UIST_CREATED) { 156 retval = -ENODEV; 157 goto out; 158 } 159 160 init_completion(&request->done); 161 162 /* 163 * Tell our userspace application about this new request 164 * by queueing an input event. 165 */ 166 uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id); 167 168 out: 169 mutex_unlock(&udev->mutex); 170 return retval; 171 } 172 173 static int uinput_request_submit(struct uinput_device *udev, 174 struct uinput_request *request) 175 { 176 int retval; 177 178 retval = uinput_request_reserve_slot(udev, request); 179 if (retval) 180 return retval; 181 182 retval = uinput_request_send(udev, request); 183 if (retval) 184 goto out; 185 186 if (!wait_for_completion_timeout(&request->done, 30 * HZ)) { 187 retval = -ETIMEDOUT; 188 goto out; 189 } 190 191 retval = request->retval; 192 193 out: 194 uinput_request_release_slot(udev, request->id); 195 return retval; 196 } 197 198 /* 199 * Fail all outstanding requests so handlers don't wait for the userspace 200 * to finish processing them. 201 */ 202 static void uinput_flush_requests(struct uinput_device *udev) 203 { 204 struct uinput_request *request; 205 int i; 206 207 spin_lock(&udev->requests_lock); 208 209 for (i = 0; i < UINPUT_NUM_REQUESTS; i++) { 210 request = udev->requests[i]; 211 if (request) { 212 request->retval = -ENODEV; 213 complete(&request->done); 214 } 215 } 216 217 spin_unlock(&udev->requests_lock); 218 } 219 220 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain) 221 { 222 uinput_dev_event(dev, EV_FF, FF_GAIN, gain); 223 } 224 225 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude) 226 { 227 uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude); 228 } 229 230 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value) 231 { 232 return uinput_dev_event(dev, EV_FF, effect_id, value); 233 } 234 235 static int uinput_dev_upload_effect(struct input_dev *dev, 236 struct ff_effect *effect, 237 struct ff_effect *old) 238 { 239 struct uinput_device *udev = input_get_drvdata(dev); 240 struct uinput_request request; 241 242 /* 243 * uinput driver does not currently support periodic effects with 244 * custom waveform since it does not have a way to pass buffer of 245 * samples (custom_data) to userspace. If ever there is a device 246 * supporting custom waveforms we would need to define an additional 247 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out. 248 */ 249 if (effect->type == FF_PERIODIC && 250 effect->u.periodic.waveform == FF_CUSTOM) 251 return -EINVAL; 252 253 request.code = UI_FF_UPLOAD; 254 request.u.upload.effect = effect; 255 request.u.upload.old = old; 256 257 return uinput_request_submit(udev, &request); 258 } 259 260 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id) 261 { 262 struct uinput_device *udev = input_get_drvdata(dev); 263 struct uinput_request request; 264 265 if (!test_bit(EV_FF, dev->evbit)) 266 return -ENOSYS; 267 268 request.code = UI_FF_ERASE; 269 request.u.effect_id = effect_id; 270 271 return uinput_request_submit(udev, &request); 272 } 273 274 static int uinput_dev_flush(struct input_dev *dev, struct file *file) 275 { 276 /* 277 * If we are called with file == NULL that means we are tearing 278 * down the device, and therefore we can not handle FF erase 279 * requests: either we are handling UI_DEV_DESTROY (and holding 280 * the udev->mutex), or the file descriptor is closed and there is 281 * nobody on the other side anymore. 282 */ 283 return file ? input_ff_flush(dev, file) : 0; 284 } 285 286 static void uinput_destroy_device(struct uinput_device *udev) 287 { 288 const char *name, *phys; 289 struct input_dev *dev = udev->dev; 290 enum uinput_state old_state = udev->state; 291 292 udev->state = UIST_NEW_DEVICE; 293 294 if (dev) { 295 name = dev->name; 296 phys = dev->phys; 297 if (old_state == UIST_CREATED) { 298 uinput_flush_requests(udev); 299 input_unregister_device(dev); 300 } else { 301 input_free_device(dev); 302 } 303 kfree(name); 304 kfree(phys); 305 udev->dev = NULL; 306 } 307 } 308 309 static int uinput_create_device(struct uinput_device *udev) 310 { 311 struct input_dev *dev = udev->dev; 312 int error, nslot; 313 314 if (udev->state != UIST_SETUP_COMPLETE) { 315 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME); 316 return -EINVAL; 317 } 318 319 if (test_bit(EV_ABS, dev->evbit)) { 320 input_alloc_absinfo(dev); 321 if (!dev->absinfo) { 322 error = -EINVAL; 323 goto fail1; 324 } 325 326 if (test_bit(ABS_MT_SLOT, dev->absbit)) { 327 nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1; 328 error = input_mt_init_slots(dev, nslot, 0); 329 if (error) 330 goto fail1; 331 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) { 332 input_set_events_per_packet(dev, 60); 333 } 334 } 335 336 if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) { 337 printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n", 338 UINPUT_NAME); 339 error = -EINVAL; 340 goto fail1; 341 } 342 343 if (udev->ff_effects_max) { 344 error = input_ff_create(dev, udev->ff_effects_max); 345 if (error) 346 goto fail1; 347 348 dev->ff->upload = uinput_dev_upload_effect; 349 dev->ff->erase = uinput_dev_erase_effect; 350 dev->ff->playback = uinput_dev_playback; 351 dev->ff->set_gain = uinput_dev_set_gain; 352 dev->ff->set_autocenter = uinput_dev_set_autocenter; 353 /* 354 * The standard input_ff_flush() implementation does 355 * not quite work for uinput as we can't reasonably 356 * handle FF requests during device teardown. 357 */ 358 dev->flush = uinput_dev_flush; 359 } 360 361 dev->event = uinput_dev_event; 362 363 input_set_drvdata(udev->dev, udev); 364 365 error = input_register_device(udev->dev); 366 if (error) 367 goto fail2; 368 369 udev->state = UIST_CREATED; 370 371 return 0; 372 373 fail2: input_ff_destroy(dev); 374 fail1: uinput_destroy_device(udev); 375 return error; 376 } 377 378 static int uinput_open(struct inode *inode, struct file *file) 379 { 380 struct uinput_device *newdev; 381 382 newdev = kzalloc(sizeof(*newdev), GFP_KERNEL); 383 if (!newdev) 384 return -ENOMEM; 385 386 mutex_init(&newdev->mutex); 387 spin_lock_init(&newdev->requests_lock); 388 init_waitqueue_head(&newdev->requests_waitq); 389 init_waitqueue_head(&newdev->waitq); 390 newdev->state = UIST_NEW_DEVICE; 391 392 file->private_data = newdev; 393 stream_open(inode, file); 394 395 return 0; 396 } 397 398 static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code, 399 const struct input_absinfo *abs) 400 { 401 int min, max, range; 402 403 min = abs->minimum; 404 max = abs->maximum; 405 406 if ((min != 0 || max != 0) && max < min) { 407 printk(KERN_DEBUG 408 "%s: invalid abs[%02x] min:%d max:%d\n", 409 UINPUT_NAME, code, min, max); 410 return -EINVAL; 411 } 412 413 if (!check_sub_overflow(max, min, &range) && abs->flat > range) { 414 printk(KERN_DEBUG 415 "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n", 416 UINPUT_NAME, code, abs->flat, min, max); 417 return -EINVAL; 418 } 419 420 /* 421 * Limit number of contacts to a reasonable value (100). This 422 * ensures that we need less than 2 pages for struct input_mt 423 * (we are not using in-kernel slot assignment so not going to 424 * allocate memory for the "red" table), and we should have no 425 * trouble getting this much memory. 426 */ 427 if (code == ABS_MT_SLOT && max > 99) { 428 printk(KERN_DEBUG 429 "%s: unreasonably large number of slots requested: %d\n", 430 UINPUT_NAME, max); 431 return -EINVAL; 432 } 433 434 return 0; 435 } 436 437 static int uinput_validate_absbits(struct input_dev *dev) 438 { 439 unsigned int cnt; 440 int error; 441 442 if (!test_bit(EV_ABS, dev->evbit)) 443 return 0; 444 445 /* 446 * Check if absmin/absmax/absfuzz/absflat are sane. 447 */ 448 449 for_each_set_bit(cnt, dev->absbit, ABS_CNT) { 450 if (!dev->absinfo) 451 return -EINVAL; 452 453 error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]); 454 if (error) 455 return error; 456 } 457 458 return 0; 459 } 460 461 static int uinput_dev_setup(struct uinput_device *udev, 462 struct uinput_setup __user *arg) 463 { 464 struct uinput_setup setup; 465 struct input_dev *dev; 466 467 if (udev->state == UIST_CREATED) 468 return -EINVAL; 469 470 if (copy_from_user(&setup, arg, sizeof(setup))) 471 return -EFAULT; 472 473 if (!setup.name[0]) 474 return -EINVAL; 475 476 dev = udev->dev; 477 dev->id = setup.id; 478 udev->ff_effects_max = setup.ff_effects_max; 479 480 kfree(dev->name); 481 dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL); 482 if (!dev->name) 483 return -ENOMEM; 484 485 udev->state = UIST_SETUP_COMPLETE; 486 return 0; 487 } 488 489 static int uinput_abs_setup(struct uinput_device *udev, 490 struct uinput_setup __user *arg, size_t size) 491 { 492 struct uinput_abs_setup setup = {}; 493 struct input_dev *dev; 494 int error; 495 496 if (size > sizeof(setup)) 497 return -E2BIG; 498 499 if (udev->state == UIST_CREATED) 500 return -EINVAL; 501 502 if (copy_from_user(&setup, arg, size)) 503 return -EFAULT; 504 505 if (setup.code > ABS_MAX) 506 return -ERANGE; 507 508 dev = udev->dev; 509 510 error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo); 511 if (error) 512 return error; 513 514 input_alloc_absinfo(dev); 515 if (!dev->absinfo) 516 return -ENOMEM; 517 518 set_bit(setup.code, dev->absbit); 519 dev->absinfo[setup.code] = setup.absinfo; 520 return 0; 521 } 522 523 /* legacy setup via write() */ 524 static int uinput_setup_device_legacy(struct uinput_device *udev, 525 const char __user *buffer, size_t count) 526 { 527 struct uinput_user_dev *user_dev; 528 struct input_dev *dev; 529 int i; 530 int retval; 531 532 if (count != sizeof(struct uinput_user_dev)) 533 return -EINVAL; 534 535 if (!udev->dev) { 536 udev->dev = input_allocate_device(); 537 if (!udev->dev) 538 return -ENOMEM; 539 } 540 541 dev = udev->dev; 542 543 user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev)); 544 if (IS_ERR(user_dev)) 545 return PTR_ERR(user_dev); 546 547 udev->ff_effects_max = user_dev->ff_effects_max; 548 549 /* Ensure name is filled in */ 550 if (!user_dev->name[0]) { 551 retval = -EINVAL; 552 goto exit; 553 } 554 555 kfree(dev->name); 556 dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE, 557 GFP_KERNEL); 558 if (!dev->name) { 559 retval = -ENOMEM; 560 goto exit; 561 } 562 563 dev->id.bustype = user_dev->id.bustype; 564 dev->id.vendor = user_dev->id.vendor; 565 dev->id.product = user_dev->id.product; 566 dev->id.version = user_dev->id.version; 567 568 for (i = 0; i < ABS_CNT; i++) { 569 input_abs_set_max(dev, i, user_dev->absmax[i]); 570 input_abs_set_min(dev, i, user_dev->absmin[i]); 571 input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]); 572 input_abs_set_flat(dev, i, user_dev->absflat[i]); 573 } 574 575 retval = uinput_validate_absbits(dev); 576 if (retval < 0) 577 goto exit; 578 579 udev->state = UIST_SETUP_COMPLETE; 580 retval = count; 581 582 exit: 583 kfree(user_dev); 584 return retval; 585 } 586 587 /* 588 * Returns true if the given timestamp is valid (i.e., if all the following 589 * conditions are satisfied), false otherwise. 590 * 1) given timestamp is positive 591 * 2) it's within the allowed offset before the current time 592 * 3) it's not in the future 593 */ 594 static bool is_valid_timestamp(const ktime_t timestamp) 595 { 596 ktime_t zero_time; 597 ktime_t current_time; 598 ktime_t min_time; 599 ktime_t offset; 600 601 zero_time = ktime_set(0, 0); 602 if (ktime_compare(zero_time, timestamp) >= 0) 603 return false; 604 605 current_time = ktime_get(); 606 offset = ktime_set(UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS, 0); 607 min_time = ktime_sub(current_time, offset); 608 609 if (ktime_after(min_time, timestamp) || ktime_after(timestamp, current_time)) 610 return false; 611 612 return true; 613 } 614 615 static ssize_t uinput_inject_events(struct uinput_device *udev, 616 const char __user *buffer, size_t count) 617 { 618 struct input_event ev; 619 size_t bytes = 0; 620 ktime_t timestamp; 621 622 if (count != 0 && count < input_event_size()) 623 return -EINVAL; 624 625 while (bytes + input_event_size() <= count) { 626 /* 627 * Note that even if some events were fetched successfully 628 * we are still going to return EFAULT instead of partial 629 * count to let userspace know that it got it's buffers 630 * all wrong. 631 */ 632 if (input_event_from_user(buffer + bytes, &ev)) 633 return -EFAULT; 634 635 timestamp = ktime_set(ev.input_event_sec, ev.input_event_usec * NSEC_PER_USEC); 636 if (is_valid_timestamp(timestamp)) 637 input_set_timestamp(udev->dev, timestamp); 638 639 input_event(udev->dev, ev.type, ev.code, ev.value); 640 bytes += input_event_size(); 641 cond_resched(); 642 } 643 644 return bytes; 645 } 646 647 static ssize_t uinput_write(struct file *file, const char __user *buffer, 648 size_t count, loff_t *ppos) 649 { 650 struct uinput_device *udev = file->private_data; 651 int retval; 652 653 if (count == 0) 654 return 0; 655 656 retval = mutex_lock_interruptible(&udev->mutex); 657 if (retval) 658 return retval; 659 660 retval = udev->state == UIST_CREATED ? 661 uinput_inject_events(udev, buffer, count) : 662 uinput_setup_device_legacy(udev, buffer, count); 663 664 mutex_unlock(&udev->mutex); 665 666 return retval; 667 } 668 669 static bool uinput_fetch_next_event(struct uinput_device *udev, 670 struct input_event *event) 671 { 672 bool have_event; 673 674 spin_lock_irq(&udev->dev->event_lock); 675 676 have_event = udev->head != udev->tail; 677 if (have_event) { 678 *event = udev->buff[udev->tail]; 679 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE; 680 } 681 682 spin_unlock_irq(&udev->dev->event_lock); 683 684 return have_event; 685 } 686 687 static ssize_t uinput_events_to_user(struct uinput_device *udev, 688 char __user *buffer, size_t count) 689 { 690 struct input_event event; 691 size_t read = 0; 692 693 while (read + input_event_size() <= count && 694 uinput_fetch_next_event(udev, &event)) { 695 696 if (input_event_to_user(buffer + read, &event)) 697 return -EFAULT; 698 699 read += input_event_size(); 700 } 701 702 return read; 703 } 704 705 static ssize_t uinput_read(struct file *file, char __user *buffer, 706 size_t count, loff_t *ppos) 707 { 708 struct uinput_device *udev = file->private_data; 709 ssize_t retval; 710 711 if (count != 0 && count < input_event_size()) 712 return -EINVAL; 713 714 do { 715 retval = mutex_lock_interruptible(&udev->mutex); 716 if (retval) 717 return retval; 718 719 if (udev->state != UIST_CREATED) 720 retval = -ENODEV; 721 else if (udev->head == udev->tail && 722 (file->f_flags & O_NONBLOCK)) 723 retval = -EAGAIN; 724 else 725 retval = uinput_events_to_user(udev, buffer, count); 726 727 mutex_unlock(&udev->mutex); 728 729 if (retval || count == 0) 730 break; 731 732 if (!(file->f_flags & O_NONBLOCK)) 733 retval = wait_event_interruptible(udev->waitq, 734 udev->head != udev->tail || 735 udev->state != UIST_CREATED); 736 } while (retval == 0); 737 738 return retval; 739 } 740 741 static __poll_t uinput_poll(struct file *file, poll_table *wait) 742 { 743 struct uinput_device *udev = file->private_data; 744 __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* uinput is always writable */ 745 746 poll_wait(file, &udev->waitq, wait); 747 748 if (udev->head != udev->tail) 749 mask |= EPOLLIN | EPOLLRDNORM; 750 751 return mask; 752 } 753 754 static int uinput_release(struct inode *inode, struct file *file) 755 { 756 struct uinput_device *udev = file->private_data; 757 758 uinput_destroy_device(udev); 759 kfree(udev); 760 761 return 0; 762 } 763 764 #ifdef CONFIG_COMPAT 765 struct uinput_ff_upload_compat { 766 __u32 request_id; 767 __s32 retval; 768 struct ff_effect_compat effect; 769 struct ff_effect_compat old; 770 }; 771 772 static int uinput_ff_upload_to_user(char __user *buffer, 773 const struct uinput_ff_upload *ff_up) 774 { 775 if (in_compat_syscall()) { 776 struct uinput_ff_upload_compat ff_up_compat; 777 778 ff_up_compat.request_id = ff_up->request_id; 779 ff_up_compat.retval = ff_up->retval; 780 /* 781 * It so happens that the pointer that gives us the trouble 782 * is the last field in the structure. Since we don't support 783 * custom waveforms in uinput anyway we can just copy the whole 784 * thing (to the compat size) and ignore the pointer. 785 */ 786 memcpy(&ff_up_compat.effect, &ff_up->effect, 787 sizeof(struct ff_effect_compat)); 788 memcpy(&ff_up_compat.old, &ff_up->old, 789 sizeof(struct ff_effect_compat)); 790 791 if (copy_to_user(buffer, &ff_up_compat, 792 sizeof(struct uinput_ff_upload_compat))) 793 return -EFAULT; 794 } else { 795 if (copy_to_user(buffer, ff_up, 796 sizeof(struct uinput_ff_upload))) 797 return -EFAULT; 798 } 799 800 return 0; 801 } 802 803 static int uinput_ff_upload_from_user(const char __user *buffer, 804 struct uinput_ff_upload *ff_up) 805 { 806 if (in_compat_syscall()) { 807 struct uinput_ff_upload_compat ff_up_compat; 808 809 if (copy_from_user(&ff_up_compat, buffer, 810 sizeof(struct uinput_ff_upload_compat))) 811 return -EFAULT; 812 813 ff_up->request_id = ff_up_compat.request_id; 814 ff_up->retval = ff_up_compat.retval; 815 memcpy(&ff_up->effect, &ff_up_compat.effect, 816 sizeof(struct ff_effect_compat)); 817 memcpy(&ff_up->old, &ff_up_compat.old, 818 sizeof(struct ff_effect_compat)); 819 820 } else { 821 if (copy_from_user(ff_up, buffer, 822 sizeof(struct uinput_ff_upload))) 823 return -EFAULT; 824 } 825 826 return 0; 827 } 828 829 #else 830 831 static int uinput_ff_upload_to_user(char __user *buffer, 832 const struct uinput_ff_upload *ff_up) 833 { 834 if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload))) 835 return -EFAULT; 836 837 return 0; 838 } 839 840 static int uinput_ff_upload_from_user(const char __user *buffer, 841 struct uinput_ff_upload *ff_up) 842 { 843 if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload))) 844 return -EFAULT; 845 846 return 0; 847 } 848 849 #endif 850 851 #define uinput_set_bit(_arg, _bit, _max) \ 852 ({ \ 853 int __ret = 0; \ 854 if (udev->state == UIST_CREATED) \ 855 __ret = -EINVAL; \ 856 else if ((_arg) > (_max)) \ 857 __ret = -EINVAL; \ 858 else set_bit((_arg), udev->dev->_bit); \ 859 __ret; \ 860 }) 861 862 static int uinput_str_to_user(void __user *dest, const char *str, 863 unsigned int maxlen) 864 { 865 char __user *p = dest; 866 int len, ret; 867 868 if (!str) 869 return -ENOENT; 870 871 if (maxlen == 0) 872 return -EINVAL; 873 874 len = strlen(str) + 1; 875 if (len > maxlen) 876 len = maxlen; 877 878 ret = copy_to_user(p, str, len); 879 if (ret) 880 return -EFAULT; 881 882 /* force terminating '\0' */ 883 ret = put_user(0, p + len - 1); 884 return ret ? -EFAULT : len; 885 } 886 887 static long uinput_ioctl_handler(struct file *file, unsigned int cmd, 888 unsigned long arg, void __user *p) 889 { 890 int retval; 891 struct uinput_device *udev = file->private_data; 892 struct uinput_ff_upload ff_up; 893 struct uinput_ff_erase ff_erase; 894 struct uinput_request *req; 895 char *phys; 896 const char *name; 897 unsigned int size; 898 899 retval = mutex_lock_interruptible(&udev->mutex); 900 if (retval) 901 return retval; 902 903 if (!udev->dev) { 904 udev->dev = input_allocate_device(); 905 if (!udev->dev) { 906 retval = -ENOMEM; 907 goto out; 908 } 909 } 910 911 switch (cmd) { 912 case UI_GET_VERSION: 913 if (put_user(UINPUT_VERSION, (unsigned int __user *)p)) 914 retval = -EFAULT; 915 goto out; 916 917 case UI_DEV_CREATE: 918 retval = uinput_create_device(udev); 919 goto out; 920 921 case UI_DEV_DESTROY: 922 uinput_destroy_device(udev); 923 goto out; 924 925 case UI_DEV_SETUP: 926 retval = uinput_dev_setup(udev, p); 927 goto out; 928 929 /* UI_ABS_SETUP is handled in the variable size ioctls */ 930 931 case UI_SET_EVBIT: 932 retval = uinput_set_bit(arg, evbit, EV_MAX); 933 goto out; 934 935 case UI_SET_KEYBIT: 936 retval = uinput_set_bit(arg, keybit, KEY_MAX); 937 goto out; 938 939 case UI_SET_RELBIT: 940 retval = uinput_set_bit(arg, relbit, REL_MAX); 941 goto out; 942 943 case UI_SET_ABSBIT: 944 retval = uinput_set_bit(arg, absbit, ABS_MAX); 945 goto out; 946 947 case UI_SET_MSCBIT: 948 retval = uinput_set_bit(arg, mscbit, MSC_MAX); 949 goto out; 950 951 case UI_SET_LEDBIT: 952 retval = uinput_set_bit(arg, ledbit, LED_MAX); 953 goto out; 954 955 case UI_SET_SNDBIT: 956 retval = uinput_set_bit(arg, sndbit, SND_MAX); 957 goto out; 958 959 case UI_SET_FFBIT: 960 retval = uinput_set_bit(arg, ffbit, FF_MAX); 961 goto out; 962 963 case UI_SET_SWBIT: 964 retval = uinput_set_bit(arg, swbit, SW_MAX); 965 goto out; 966 967 case UI_SET_PROPBIT: 968 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX); 969 goto out; 970 971 case UI_SET_PHYS: 972 if (udev->state == UIST_CREATED) { 973 retval = -EINVAL; 974 goto out; 975 } 976 977 phys = strndup_user(p, 1024); 978 if (IS_ERR(phys)) { 979 retval = PTR_ERR(phys); 980 goto out; 981 } 982 983 kfree(udev->dev->phys); 984 udev->dev->phys = phys; 985 goto out; 986 987 case UI_BEGIN_FF_UPLOAD: 988 retval = uinput_ff_upload_from_user(p, &ff_up); 989 if (retval) 990 goto out; 991 992 req = uinput_request_find(udev, ff_up.request_id); 993 if (!req || req->code != UI_FF_UPLOAD || 994 !req->u.upload.effect) { 995 retval = -EINVAL; 996 goto out; 997 } 998 999 ff_up.retval = 0; 1000 ff_up.effect = *req->u.upload.effect; 1001 if (req->u.upload.old) 1002 ff_up.old = *req->u.upload.old; 1003 else 1004 memset(&ff_up.old, 0, sizeof(struct ff_effect)); 1005 1006 retval = uinput_ff_upload_to_user(p, &ff_up); 1007 goto out; 1008 1009 case UI_BEGIN_FF_ERASE: 1010 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) { 1011 retval = -EFAULT; 1012 goto out; 1013 } 1014 1015 req = uinput_request_find(udev, ff_erase.request_id); 1016 if (!req || req->code != UI_FF_ERASE) { 1017 retval = -EINVAL; 1018 goto out; 1019 } 1020 1021 ff_erase.retval = 0; 1022 ff_erase.effect_id = req->u.effect_id; 1023 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) { 1024 retval = -EFAULT; 1025 goto out; 1026 } 1027 1028 goto out; 1029 1030 case UI_END_FF_UPLOAD: 1031 retval = uinput_ff_upload_from_user(p, &ff_up); 1032 if (retval) 1033 goto out; 1034 1035 req = uinput_request_find(udev, ff_up.request_id); 1036 if (!req || req->code != UI_FF_UPLOAD || 1037 !req->u.upload.effect) { 1038 retval = -EINVAL; 1039 goto out; 1040 } 1041 1042 req->retval = ff_up.retval; 1043 complete(&req->done); 1044 goto out; 1045 1046 case UI_END_FF_ERASE: 1047 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) { 1048 retval = -EFAULT; 1049 goto out; 1050 } 1051 1052 req = uinput_request_find(udev, ff_erase.request_id); 1053 if (!req || req->code != UI_FF_ERASE) { 1054 retval = -EINVAL; 1055 goto out; 1056 } 1057 1058 req->retval = ff_erase.retval; 1059 complete(&req->done); 1060 goto out; 1061 } 1062 1063 size = _IOC_SIZE(cmd); 1064 1065 /* Now check variable-length commands */ 1066 switch (cmd & ~IOCSIZE_MASK) { 1067 case UI_GET_SYSNAME(0): 1068 if (udev->state != UIST_CREATED) { 1069 retval = -ENOENT; 1070 goto out; 1071 } 1072 name = dev_name(&udev->dev->dev); 1073 retval = uinput_str_to_user(p, name, size); 1074 goto out; 1075 1076 case UI_ABS_SETUP & ~IOCSIZE_MASK: 1077 retval = uinput_abs_setup(udev, p, size); 1078 goto out; 1079 } 1080 1081 retval = -EINVAL; 1082 out: 1083 mutex_unlock(&udev->mutex); 1084 return retval; 1085 } 1086 1087 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 1088 { 1089 return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg); 1090 } 1091 1092 #ifdef CONFIG_COMPAT 1093 1094 /* 1095 * These IOCTLs change their size and thus their numbers between 1096 * 32 and 64 bits. 1097 */ 1098 #define UI_SET_PHYS_COMPAT \ 1099 _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t) 1100 #define UI_BEGIN_FF_UPLOAD_COMPAT \ 1101 _IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload_compat) 1102 #define UI_END_FF_UPLOAD_COMPAT \ 1103 _IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload_compat) 1104 1105 static long uinput_compat_ioctl(struct file *file, 1106 unsigned int cmd, unsigned long arg) 1107 { 1108 switch (cmd) { 1109 case UI_SET_PHYS_COMPAT: 1110 cmd = UI_SET_PHYS; 1111 break; 1112 case UI_BEGIN_FF_UPLOAD_COMPAT: 1113 cmd = UI_BEGIN_FF_UPLOAD; 1114 break; 1115 case UI_END_FF_UPLOAD_COMPAT: 1116 cmd = UI_END_FF_UPLOAD; 1117 break; 1118 } 1119 1120 return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg)); 1121 } 1122 #endif 1123 1124 static const struct file_operations uinput_fops = { 1125 .owner = THIS_MODULE, 1126 .open = uinput_open, 1127 .release = uinput_release, 1128 .read = uinput_read, 1129 .write = uinput_write, 1130 .poll = uinput_poll, 1131 .unlocked_ioctl = uinput_ioctl, 1132 #ifdef CONFIG_COMPAT 1133 .compat_ioctl = uinput_compat_ioctl, 1134 #endif 1135 }; 1136 1137 static struct miscdevice uinput_misc = { 1138 .fops = &uinput_fops, 1139 .minor = UINPUT_MINOR, 1140 .name = UINPUT_NAME, 1141 }; 1142 module_misc_device(uinput_misc); 1143 1144 MODULE_ALIAS_MISCDEV(UINPUT_MINOR); 1145 MODULE_ALIAS("devname:" UINPUT_NAME); 1146 1147 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho"); 1148 MODULE_DESCRIPTION("User level driver support for input subsystem"); 1149 MODULE_LICENSE("GPL"); 1150