1 /* 2 * Event char devices, giving access to raw input device events. 3 * 4 * Copyright (c) 1999-2002 Vojtech Pavlik 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10 11 #define EVDEV_MINOR_BASE 64 12 #define EVDEV_MINORS 32 13 #define EVDEV_BUFFER_SIZE 64 14 15 #include <linux/poll.h> 16 #include <linux/slab.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/input.h> 20 #include <linux/major.h> 21 #include <linux/device.h> 22 #include <linux/compat.h> 23 24 struct evdev { 25 int exist; 26 int open; 27 int minor; 28 char name[16]; 29 struct input_handle handle; 30 wait_queue_head_t wait; 31 struct evdev_client *grab; 32 struct list_head client_list; 33 struct device dev; 34 }; 35 36 struct evdev_client { 37 struct input_event buffer[EVDEV_BUFFER_SIZE]; 38 int head; 39 int tail; 40 struct fasync_struct *fasync; 41 struct evdev *evdev; 42 struct list_head node; 43 }; 44 45 static struct evdev *evdev_table[EVDEV_MINORS]; 46 47 static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) 48 { 49 struct evdev *evdev = handle->private; 50 struct evdev_client *client; 51 52 if (evdev->grab) { 53 client = evdev->grab; 54 55 do_gettimeofday(&client->buffer[client->head].time); 56 client->buffer[client->head].type = type; 57 client->buffer[client->head].code = code; 58 client->buffer[client->head].value = value; 59 client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1); 60 61 kill_fasync(&client->fasync, SIGIO, POLL_IN); 62 } else 63 list_for_each_entry(client, &evdev->client_list, node) { 64 65 do_gettimeofday(&client->buffer[client->head].time); 66 client->buffer[client->head].type = type; 67 client->buffer[client->head].code = code; 68 client->buffer[client->head].value = value; 69 client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1); 70 71 kill_fasync(&client->fasync, SIGIO, POLL_IN); 72 } 73 74 wake_up_interruptible(&evdev->wait); 75 } 76 77 static int evdev_fasync(int fd, struct file *file, int on) 78 { 79 struct evdev_client *client = file->private_data; 80 int retval; 81 82 retval = fasync_helper(fd, file, on, &client->fasync); 83 84 return retval < 0 ? retval : 0; 85 } 86 87 static int evdev_flush(struct file *file, fl_owner_t id) 88 { 89 struct evdev_client *client = file->private_data; 90 struct evdev *evdev = client->evdev; 91 92 if (!evdev->exist) 93 return -ENODEV; 94 95 return input_flush_device(&evdev->handle, file); 96 } 97 98 static void evdev_free(struct device *dev) 99 { 100 struct evdev *evdev = container_of(dev, struct evdev, dev); 101 102 evdev_table[evdev->minor] = NULL; 103 kfree(evdev); 104 } 105 106 static int evdev_release(struct inode *inode, struct file *file) 107 { 108 struct evdev_client *client = file->private_data; 109 struct evdev *evdev = client->evdev; 110 111 if (evdev->grab == client) { 112 input_release_device(&evdev->handle); 113 evdev->grab = NULL; 114 } 115 116 evdev_fasync(-1, file, 0); 117 list_del(&client->node); 118 kfree(client); 119 120 if (!--evdev->open && evdev->exist) 121 input_close_device(&evdev->handle); 122 123 put_device(&evdev->dev); 124 125 return 0; 126 } 127 128 static int evdev_open(struct inode *inode, struct file *file) 129 { 130 struct evdev_client *client; 131 struct evdev *evdev; 132 int i = iminor(inode) - EVDEV_MINOR_BASE; 133 int error; 134 135 if (i >= EVDEV_MINORS) 136 return -ENODEV; 137 138 evdev = evdev_table[i]; 139 140 if (!evdev || !evdev->exist) 141 return -ENODEV; 142 143 get_device(&evdev->dev); 144 145 client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL); 146 if (!client) { 147 error = -ENOMEM; 148 goto err_put_evdev; 149 } 150 151 client->evdev = evdev; 152 list_add_tail(&client->node, &evdev->client_list); 153 154 if (!evdev->open++ && evdev->exist) { 155 error = input_open_device(&evdev->handle); 156 if (error) 157 goto err_free_client; 158 } 159 160 file->private_data = client; 161 return 0; 162 163 err_free_client: 164 list_del(&client->node); 165 kfree(client); 166 err_put_evdev: 167 put_device(&evdev->dev); 168 return error; 169 } 170 171 #ifdef CONFIG_COMPAT 172 173 struct input_event_compat { 174 struct compat_timeval time; 175 __u16 type; 176 __u16 code; 177 __s32 value; 178 }; 179 180 /* Note to the author of this code: did it ever occur to 181 you why the ifdefs are needed? Think about it again. -AK */ 182 #ifdef CONFIG_X86_64 183 # define COMPAT_TEST is_compat_task() 184 #elif defined(CONFIG_IA64) 185 # define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current)) 186 #elif defined(CONFIG_S390) 187 # define COMPAT_TEST test_thread_flag(TIF_31BIT) 188 #elif defined(CONFIG_MIPS) 189 # define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR) 190 #else 191 # define COMPAT_TEST test_thread_flag(TIF_32BIT) 192 #endif 193 194 static inline size_t evdev_event_size(void) 195 { 196 return COMPAT_TEST ? 197 sizeof(struct input_event_compat) : sizeof(struct input_event); 198 } 199 200 static int evdev_event_from_user(const char __user *buffer, struct input_event *event) 201 { 202 if (COMPAT_TEST) { 203 struct input_event_compat compat_event; 204 205 if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat))) 206 return -EFAULT; 207 208 event->time.tv_sec = compat_event.time.tv_sec; 209 event->time.tv_usec = compat_event.time.tv_usec; 210 event->type = compat_event.type; 211 event->code = compat_event.code; 212 event->value = compat_event.value; 213 214 } else { 215 if (copy_from_user(event, buffer, sizeof(struct input_event))) 216 return -EFAULT; 217 } 218 219 return 0; 220 } 221 222 static int evdev_event_to_user(char __user *buffer, const struct input_event *event) 223 { 224 if (COMPAT_TEST) { 225 struct input_event_compat compat_event; 226 227 compat_event.time.tv_sec = event->time.tv_sec; 228 compat_event.time.tv_usec = event->time.tv_usec; 229 compat_event.type = event->type; 230 compat_event.code = event->code; 231 compat_event.value = event->value; 232 233 if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat))) 234 return -EFAULT; 235 236 } else { 237 if (copy_to_user(buffer, event, sizeof(struct input_event))) 238 return -EFAULT; 239 } 240 241 return 0; 242 } 243 244 #else 245 246 static inline size_t evdev_event_size(void) 247 { 248 return sizeof(struct input_event); 249 } 250 251 static int evdev_event_from_user(const char __user *buffer, struct input_event *event) 252 { 253 if (copy_from_user(event, buffer, sizeof(struct input_event))) 254 return -EFAULT; 255 256 return 0; 257 } 258 259 static int evdev_event_to_user(char __user *buffer, const struct input_event *event) 260 { 261 if (copy_to_user(buffer, event, sizeof(struct input_event))) 262 return -EFAULT; 263 264 return 0; 265 } 266 267 #endif /* CONFIG_COMPAT */ 268 269 static ssize_t evdev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 270 { 271 struct evdev_client *client = file->private_data; 272 struct evdev *evdev = client->evdev; 273 struct input_event event; 274 int retval = 0; 275 276 if (!evdev->exist) 277 return -ENODEV; 278 279 while (retval < count) { 280 281 if (evdev_event_from_user(buffer + retval, &event)) 282 return -EFAULT; 283 input_inject_event(&evdev->handle, event.type, event.code, event.value); 284 retval += evdev_event_size(); 285 } 286 287 return retval; 288 } 289 290 static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 291 { 292 struct evdev_client *client = file->private_data; 293 struct evdev *evdev = client->evdev; 294 int retval; 295 296 if (count < evdev_event_size()) 297 return -EINVAL; 298 299 if (client->head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK)) 300 return -EAGAIN; 301 302 retval = wait_event_interruptible(evdev->wait, 303 client->head != client->tail || !evdev->exist); 304 if (retval) 305 return retval; 306 307 if (!evdev->exist) 308 return -ENODEV; 309 310 while (client->head != client->tail && retval + evdev_event_size() <= count) { 311 312 struct input_event *event = (struct input_event *) client->buffer + client->tail; 313 314 if (evdev_event_to_user(buffer + retval, event)) 315 return -EFAULT; 316 317 client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1); 318 retval += evdev_event_size(); 319 } 320 321 return retval; 322 } 323 324 /* No kernel lock - fine */ 325 static unsigned int evdev_poll(struct file *file, poll_table *wait) 326 { 327 struct evdev_client *client = file->private_data; 328 struct evdev *evdev = client->evdev; 329 330 poll_wait(file, &evdev->wait, wait); 331 return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) | 332 (evdev->exist ? 0 : (POLLHUP | POLLERR)); 333 } 334 335 #ifdef CONFIG_COMPAT 336 337 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) 338 #define NBITS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) 339 340 #ifdef __BIG_ENDIAN 341 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 342 unsigned int maxlen, void __user *p, int compat) 343 { 344 int len, i; 345 346 if (compat) { 347 len = NBITS_COMPAT(maxbit) * sizeof(compat_long_t); 348 if (len > maxlen) 349 len = maxlen; 350 351 for (i = 0; i < len / sizeof(compat_long_t); i++) 352 if (copy_to_user((compat_long_t __user *) p + i, 353 (compat_long_t *) bits + 354 i + 1 - ((i % 2) << 1), 355 sizeof(compat_long_t))) 356 return -EFAULT; 357 } else { 358 len = NBITS(maxbit) * sizeof(long); 359 if (len > maxlen) 360 len = maxlen; 361 362 if (copy_to_user(p, bits, len)) 363 return -EFAULT; 364 } 365 366 return len; 367 } 368 #else 369 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 370 unsigned int maxlen, void __user *p, int compat) 371 { 372 int len = compat ? 373 NBITS_COMPAT(maxbit) * sizeof(compat_long_t) : 374 NBITS(maxbit) * sizeof(long); 375 376 if (len > maxlen) 377 len = maxlen; 378 379 return copy_to_user(p, bits, len) ? -EFAULT : len; 380 } 381 #endif /* __BIG_ENDIAN */ 382 383 #else 384 385 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 386 unsigned int maxlen, void __user *p, int compat) 387 { 388 int len = NBITS(maxbit) * sizeof(long); 389 390 if (len > maxlen) 391 len = maxlen; 392 393 return copy_to_user(p, bits, len) ? -EFAULT : len; 394 } 395 396 #endif /* CONFIG_COMPAT */ 397 398 static int str_to_user(const char *str, unsigned int maxlen, void __user *p) 399 { 400 int len; 401 402 if (!str) 403 return -ENOENT; 404 405 len = strlen(str) + 1; 406 if (len > maxlen) 407 len = maxlen; 408 409 return copy_to_user(p, str, len) ? -EFAULT : len; 410 } 411 412 static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 413 void __user *p, int compat_mode) 414 { 415 struct evdev_client *client = file->private_data; 416 struct evdev *evdev = client->evdev; 417 struct input_dev *dev = evdev->handle.dev; 418 struct input_absinfo abs; 419 struct ff_effect effect; 420 int __user *ip = (int __user *)p; 421 int i, t, u, v; 422 int error; 423 424 if (!evdev->exist) 425 return -ENODEV; 426 427 switch (cmd) { 428 429 case EVIOCGVERSION: 430 return put_user(EV_VERSION, ip); 431 432 case EVIOCGID: 433 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 434 return -EFAULT; 435 return 0; 436 437 case EVIOCGREP: 438 if (!test_bit(EV_REP, dev->evbit)) 439 return -ENOSYS; 440 if (put_user(dev->rep[REP_DELAY], ip)) 441 return -EFAULT; 442 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 443 return -EFAULT; 444 return 0; 445 446 case EVIOCSREP: 447 if (!test_bit(EV_REP, dev->evbit)) 448 return -ENOSYS; 449 if (get_user(u, ip)) 450 return -EFAULT; 451 if (get_user(v, ip + 1)) 452 return -EFAULT; 453 454 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 455 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 456 457 return 0; 458 459 case EVIOCGKEYCODE: 460 if (get_user(t, ip)) 461 return -EFAULT; 462 463 error = dev->getkeycode(dev, t, &v); 464 if (error) 465 return error; 466 467 if (put_user(v, ip + 1)) 468 return -EFAULT; 469 470 return 0; 471 472 case EVIOCSKEYCODE: 473 if (get_user(t, ip) || get_user(v, ip + 1)) 474 return -EFAULT; 475 476 return dev->setkeycode(dev, t, v); 477 478 case EVIOCSFF: 479 if (copy_from_user(&effect, p, sizeof(effect))) 480 return -EFAULT; 481 482 error = input_ff_upload(dev, &effect, file); 483 484 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 485 return -EFAULT; 486 487 return error; 488 489 case EVIOCRMFF: 490 return input_ff_erase(dev, (int)(unsigned long) p, file); 491 492 case EVIOCGEFFECTS: 493 i = test_bit(EV_FF, dev->evbit) ? dev->ff->max_effects : 0; 494 if (put_user(i, ip)) 495 return -EFAULT; 496 return 0; 497 498 case EVIOCGRAB: 499 if (p) { 500 if (evdev->grab) 501 return -EBUSY; 502 if (input_grab_device(&evdev->handle)) 503 return -EBUSY; 504 evdev->grab = client; 505 return 0; 506 } else { 507 if (evdev->grab != client) 508 return -EINVAL; 509 input_release_device(&evdev->handle); 510 evdev->grab = NULL; 511 return 0; 512 } 513 514 default: 515 516 if (_IOC_TYPE(cmd) != 'E') 517 return -EINVAL; 518 519 if (_IOC_DIR(cmd) == _IOC_READ) { 520 521 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) { 522 523 unsigned long *bits; 524 int len; 525 526 switch (_IOC_NR(cmd) & EV_MAX) { 527 case 0: bits = dev->evbit; len = EV_MAX; break; 528 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; 529 case EV_REL: bits = dev->relbit; len = REL_MAX; break; 530 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; 531 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; 532 case EV_LED: bits = dev->ledbit; len = LED_MAX; break; 533 case EV_SND: bits = dev->sndbit; len = SND_MAX; break; 534 case EV_FF: bits = dev->ffbit; len = FF_MAX; break; 535 case EV_SW: bits = dev->swbit; len = SW_MAX; break; 536 default: return -EINVAL; 537 } 538 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode); 539 } 540 541 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) 542 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), 543 p, compat_mode); 544 545 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) 546 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd), 547 p, compat_mode); 548 549 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) 550 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd), 551 p, compat_mode); 552 553 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) 554 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd), 555 p, compat_mode); 556 557 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) 558 return str_to_user(dev->name, _IOC_SIZE(cmd), p); 559 560 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) 561 return str_to_user(dev->phys, _IOC_SIZE(cmd), p); 562 563 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) 564 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p); 565 566 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 567 568 t = _IOC_NR(cmd) & ABS_MAX; 569 570 abs.value = dev->abs[t]; 571 abs.minimum = dev->absmin[t]; 572 abs.maximum = dev->absmax[t]; 573 abs.fuzz = dev->absfuzz[t]; 574 abs.flat = dev->absflat[t]; 575 576 if (copy_to_user(p, &abs, sizeof(struct input_absinfo))) 577 return -EFAULT; 578 579 return 0; 580 } 581 582 } 583 584 if (_IOC_DIR(cmd) == _IOC_WRITE) { 585 586 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 587 588 t = _IOC_NR(cmd) & ABS_MAX; 589 590 if (copy_from_user(&abs, p, sizeof(struct input_absinfo))) 591 return -EFAULT; 592 593 dev->abs[t] = abs.value; 594 dev->absmin[t] = abs.minimum; 595 dev->absmax[t] = abs.maximum; 596 dev->absfuzz[t] = abs.fuzz; 597 dev->absflat[t] = abs.flat; 598 599 return 0; 600 } 601 } 602 } 603 return -EINVAL; 604 } 605 606 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 607 { 608 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 609 } 610 611 #ifdef CONFIG_COMPAT 612 static long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) 613 { 614 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 615 } 616 #endif 617 618 static const struct file_operations evdev_fops = { 619 .owner = THIS_MODULE, 620 .read = evdev_read, 621 .write = evdev_write, 622 .poll = evdev_poll, 623 .open = evdev_open, 624 .release = evdev_release, 625 .unlocked_ioctl = evdev_ioctl, 626 #ifdef CONFIG_COMPAT 627 .compat_ioctl = evdev_ioctl_compat, 628 #endif 629 .fasync = evdev_fasync, 630 .flush = evdev_flush 631 }; 632 633 static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 634 const struct input_device_id *id) 635 { 636 struct evdev *evdev; 637 int minor; 638 int error; 639 640 for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++); 641 if (minor == EVDEV_MINORS) { 642 printk(KERN_ERR "evdev: no more free evdev devices\n"); 643 return -ENFILE; 644 } 645 646 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL); 647 if (!evdev) 648 return -ENOMEM; 649 650 INIT_LIST_HEAD(&evdev->client_list); 651 init_waitqueue_head(&evdev->wait); 652 653 evdev->exist = 1; 654 evdev->minor = minor; 655 evdev->handle.dev = dev; 656 evdev->handle.name = evdev->name; 657 evdev->handle.handler = handler; 658 evdev->handle.private = evdev; 659 snprintf(evdev->name, sizeof(evdev->name), "event%d", minor); 660 661 snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id), 662 "event%d", minor); 663 evdev->dev.class = &input_class; 664 evdev->dev.parent = &dev->dev; 665 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor); 666 evdev->dev.release = evdev_free; 667 device_initialize(&evdev->dev); 668 669 evdev_table[minor] = evdev; 670 671 error = device_add(&evdev->dev); 672 if (error) 673 goto err_free_evdev; 674 675 error = input_register_handle(&evdev->handle); 676 if (error) 677 goto err_delete_evdev; 678 679 return 0; 680 681 err_delete_evdev: 682 device_del(&evdev->dev); 683 err_free_evdev: 684 put_device(&evdev->dev); 685 return error; 686 } 687 688 static void evdev_disconnect(struct input_handle *handle) 689 { 690 struct evdev *evdev = handle->private; 691 struct evdev_client *client; 692 693 input_unregister_handle(handle); 694 device_del(&evdev->dev); 695 696 evdev->exist = 0; 697 698 if (evdev->open) { 699 input_flush_device(handle, NULL); 700 input_close_device(handle); 701 list_for_each_entry(client, &evdev->client_list, node) 702 kill_fasync(&client->fasync, SIGIO, POLL_HUP); 703 wake_up_interruptible(&evdev->wait); 704 } 705 706 put_device(&evdev->dev); 707 } 708 709 static const struct input_device_id evdev_ids[] = { 710 { .driver_info = 1 }, /* Matches all devices */ 711 { }, /* Terminating zero entry */ 712 }; 713 714 MODULE_DEVICE_TABLE(input, evdev_ids); 715 716 static struct input_handler evdev_handler = { 717 .event = evdev_event, 718 .connect = evdev_connect, 719 .disconnect = evdev_disconnect, 720 .fops = &evdev_fops, 721 .minor = EVDEV_MINOR_BASE, 722 .name = "evdev", 723 .id_table = evdev_ids, 724 }; 725 726 static int __init evdev_init(void) 727 { 728 return input_register_handler(&evdev_handler); 729 } 730 731 static void __exit evdev_exit(void) 732 { 733 input_unregister_handler(&evdev_handler); 734 } 735 736 module_init(evdev_init); 737 module_exit(evdev_exit); 738 739 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 740 MODULE_DESCRIPTION("Input driver event char devices"); 741 MODULE_LICENSE("GPL"); 742