1 /* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */ 2 /* 3 * USB descriptor handling functions for libusbx 4 * Copyright 2007 Daniel Drake <dsd (at) gentoo.org> 5 * Copyright 2001 Johannes Erdfelt <johannes (at) erdfelt.com> 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with this library; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 #include <errno.h> 23 #include <stdint.h> 24 #include <stdlib.h> 25 #include <string.h> 26 27 #include "libusbi.h" 28 29 #define DESC_HEADER_LENGTH 2 30 #define DEVICE_DESC_LENGTH 18 31 #define CONFIG_DESC_LENGTH 9 32 #define INTERFACE_DESC_LENGTH 9 33 #define ENDPOINT_DESC_LENGTH 7 34 #define ENDPOINT_AUDIO_DESC_LENGTH 9 35 36 /** @defgroup desc USB descriptors 37 * This page details how to examine the various standard USB descriptors 38 * for detected devices 39 */ 40 41 /* set host_endian if the w values are already in host endian format, 42 * as opposed to bus endian. */ 43 int usbi_parse_descriptor(const unsigned char *source, const char *descriptor, 44 void *dest, int host_endian) 45 { 46 const unsigned char *sp = source; 47 unsigned char *dp = dest; 48 uint16_t w; 49 const char *cp; 50 uint32_t d; 51 52 for (cp = descriptor; *cp; cp++) { 53 switch (*cp) { 54 case 'b': /* 8-bit byte */ 55 *dp++ = *sp++; 56 break; 57 case 'w': /* 16-bit word, convert from little endian to CPU */ 58 dp += ((uintptr_t)dp & 1); /* Align to word boundary */ 59 60 if (host_endian) { 61 memcpy(dp, sp, 2); 62 } else { 63 w = (sp[1] << 8) | sp[0]; 64 *((uint16_t *)dp) = w; 65 } 66 sp += 2; 67 dp += 2; 68 break; 69 case 'd': /* 32-bit word, convert from little endian to CPU */ 70 dp += ((uintptr_t)dp & 1); /* Align to word boundary */ 71 72 if (host_endian) { 73 memcpy(dp, sp, 4); 74 } else { 75 d = (sp[3] << 24) | (sp[2] << 16) | 76 (sp[1] << 8) | sp[0]; 77 *((uint32_t *)dp) = d; 78 } 79 sp += 4; 80 dp += 4; 81 break; 82 case 'u': /* 16 byte UUID */ 83 memcpy(dp, sp, 16); 84 sp += 16; 85 dp += 16; 86 break; 87 } 88 } 89 90 return (int) (sp - source); 91 } 92 93 static void clear_endpoint(struct libusb_endpoint_descriptor *endpoint) 94 { 95 if (endpoint->extra) 96 free((unsigned char *) endpoint->extra); 97 } 98 99 static int parse_endpoint(struct libusb_context *ctx, 100 struct libusb_endpoint_descriptor *endpoint, unsigned char *buffer, 101 int size, int host_endian) 102 { 103 struct usb_descriptor_header header; 104 unsigned char *extra; 105 unsigned char *begin; 106 int parsed = 0; 107 int len; 108 109 if (size < DESC_HEADER_LENGTH) { 110 usbi_err(ctx, "short endpoint descriptor read %d/%d", 111 size, DESC_HEADER_LENGTH); 112 return LIBUSB_ERROR_IO; 113 } 114 115 usbi_parse_descriptor(buffer, "bb", &header, 0); 116 if (header.bDescriptorType != LIBUSB_DT_ENDPOINT) { 117 usbi_err(ctx, "unexpected descriptor %x (expected %x)", 118 header.bDescriptorType, LIBUSB_DT_ENDPOINT); 119 return parsed; 120 } 121 if (header.bLength > size) { 122 usbi_warn(ctx, "short endpoint descriptor read %d/%d", 123 size, header.bLength); 124 return parsed; 125 } 126 if (header.bLength >= ENDPOINT_AUDIO_DESC_LENGTH) 127 usbi_parse_descriptor(buffer, "bbbbwbbb", endpoint, host_endian); 128 else if (header.bLength >= ENDPOINT_DESC_LENGTH) 129 usbi_parse_descriptor(buffer, "bbbbwb", endpoint, host_endian); 130 else { 131 usbi_err(ctx, "invalid endpoint bLength (%d)", header.bLength); 132 return LIBUSB_ERROR_IO; 133 } 134 135 buffer += header.bLength; 136 size -= header.bLength; 137 parsed += header.bLength; 138 139 /* Skip over the rest of the Class Specific or Vendor Specific */ 140 /* descriptors */ 141 begin = buffer; 142 while (size >= DESC_HEADER_LENGTH) { 143 usbi_parse_descriptor(buffer, "bb", &header, 0); 144 if (header.bLength < DESC_HEADER_LENGTH) { 145 usbi_err(ctx, "invalid extra ep desc len (%d)", 146 header.bLength); 147 return LIBUSB_ERROR_IO; 148 } else if (header.bLength > size) { 149 usbi_warn(ctx, "short extra ep desc read %d/%d", 150 size, header.bLength); 151 return parsed; 152 } 153 154 /* If we find another "proper" descriptor then we're done */ 155 if ((header.bDescriptorType == LIBUSB_DT_ENDPOINT) || 156 (header.bDescriptorType == LIBUSB_DT_INTERFACE) || 157 (header.bDescriptorType == LIBUSB_DT_CONFIG) || 158 (header.bDescriptorType == LIBUSB_DT_DEVICE)) 159 break; 160 161 usbi_dbg("skipping descriptor %x", header.bDescriptorType); 162 buffer += header.bLength; 163 size -= header.bLength; 164 parsed += header.bLength; 165 } 166 167 /* Copy any unknown descriptors into a storage area for drivers */ 168 /* to later parse */ 169 len = (int)(buffer - begin); 170 if (!len) { 171 endpoint->extra = NULL; 172 endpoint->extra_length = 0; 173 return parsed; 174 } 175 176 extra = malloc(len); 177 endpoint->extra = extra; 178 if (!extra) { 179 endpoint->extra_length = 0; 180 return LIBUSB_ERROR_NO_MEM; 181 } 182 183 memcpy(extra, begin, len); 184 endpoint->extra_length = len; 185 186 return parsed; 187 } 188 189 static void clear_interface(struct libusb_interface *usb_interface) 190 { 191 int i; 192 int j; 193 194 if (usb_interface->altsetting) { 195 for (i = 0; i < usb_interface->num_altsetting; i++) { 196 struct libusb_interface_descriptor *ifp = 197 (struct libusb_interface_descriptor *) 198 usb_interface->altsetting + i; 199 if (ifp->extra) 200 free((void *) ifp->extra); 201 if (ifp->endpoint) { 202 for (j = 0; j < ifp->bNumEndpoints; j++) 203 clear_endpoint((struct libusb_endpoint_descriptor *) 204 ifp->endpoint + j); 205 free((void *) ifp->endpoint); 206 } 207 } 208 free((void *) usb_interface->altsetting); 209 usb_interface->altsetting = NULL; 210 } 211 212 } 213 214 static int parse_interface(libusb_context *ctx, 215 struct libusb_interface *usb_interface, unsigned char *buffer, int size, 216 int host_endian) 217 { 218 int i; 219 int len; 220 int r; 221 int parsed = 0; 222 int interface_number = -1; 223 size_t tmp; 224 struct usb_descriptor_header header; 225 struct libusb_interface_descriptor *ifp; 226 unsigned char *begin; 227 228 usb_interface->num_altsetting = 0; 229 230 while (size >= INTERFACE_DESC_LENGTH) { 231 struct libusb_interface_descriptor *altsetting = 232 (struct libusb_interface_descriptor *) usb_interface->altsetting; 233 altsetting = usbi_reallocf(altsetting, 234 sizeof(struct libusb_interface_descriptor) * 235 (usb_interface->num_altsetting + 1)); 236 if (!altsetting) { 237 r = LIBUSB_ERROR_NO_MEM; 238 goto err; 239 } 240 usb_interface->altsetting = altsetting; 241 242 ifp = altsetting + usb_interface->num_altsetting; 243 usbi_parse_descriptor(buffer, "bbbbbbbbb", ifp, 0); 244 if (ifp->bDescriptorType != LIBUSB_DT_INTERFACE) { 245 usbi_err(ctx, "unexpected descriptor %x (expected %x)", 246 ifp->bDescriptorType, LIBUSB_DT_INTERFACE); 247 return parsed; 248 } 249 if (ifp->bLength < INTERFACE_DESC_LENGTH) { 250 usbi_err(ctx, "invalid interface bLength (%d)", 251 ifp->bLength); 252 r = LIBUSB_ERROR_IO; 253 goto err; 254 } 255 if (ifp->bLength > size) { 256 usbi_warn(ctx, "short intf descriptor read %d/%d", 257 size, ifp->bLength); 258 return parsed; 259 } 260 if (ifp->bNumEndpoints > USB_MAXENDPOINTS) { 261 usbi_err(ctx, "too many endpoints (%d)", ifp->bNumEndpoints); 262 r = LIBUSB_ERROR_IO; 263 goto err; 264 } 265 266 usb_interface->num_altsetting++; 267 ifp->extra = NULL; 268 ifp->extra_length = 0; 269 ifp->endpoint = NULL; 270 271 if (interface_number == -1) 272 interface_number = ifp->bInterfaceNumber; 273 274 /* Skip over the interface */ 275 buffer += ifp->bLength; 276 parsed += ifp->bLength; 277 size -= ifp->bLength; 278 279 begin = buffer; 280 281 /* Skip over any interface, class or vendor descriptors */ 282 while (size >= DESC_HEADER_LENGTH) { 283 usbi_parse_descriptor(buffer, "bb", &header, 0); 284 if (header.bLength < DESC_HEADER_LENGTH) { 285 usbi_err(ctx, 286 "invalid extra intf desc len (%d)", 287 header.bLength); 288 r = LIBUSB_ERROR_IO; 289 goto err; 290 } else if (header.bLength > size) { 291 usbi_warn(ctx, 292 "short extra intf desc read %d/%d", 293 size, header.bLength); 294 return parsed; 295 } 296 297 /* If we find another "proper" descriptor then we're done */ 298 if ((header.bDescriptorType == LIBUSB_DT_INTERFACE) || 299 (header.bDescriptorType == LIBUSB_DT_ENDPOINT) || 300 (header.bDescriptorType == LIBUSB_DT_CONFIG) || 301 (header.bDescriptorType == LIBUSB_DT_DEVICE)) 302 break; 303 304 buffer += header.bLength; 305 parsed += header.bLength; 306 size -= header.bLength; 307 } 308 309 /* Copy any unknown descriptors into a storage area for */ 310 /* drivers to later parse */ 311 len = (int)(buffer - begin); 312 if (len) { 313 ifp->extra = malloc(len); 314 if (!ifp->extra) { 315 r = LIBUSB_ERROR_NO_MEM; 316 goto err; 317 } 318 memcpy((unsigned char *) ifp->extra, begin, len); 319 ifp->extra_length = len; 320 } 321 322 if (ifp->bNumEndpoints > 0) { 323 struct libusb_endpoint_descriptor *endpoint; 324 tmp = ifp->bNumEndpoints * sizeof(struct libusb_endpoint_descriptor); 325 endpoint = malloc(tmp); 326 ifp->endpoint = endpoint; 327 if (!endpoint) { 328 r = LIBUSB_ERROR_NO_MEM; 329 goto err; 330 } 331 332 memset(endpoint, 0, tmp); 333 for (i = 0; i < ifp->bNumEndpoints; i++) { 334 r = parse_endpoint(ctx, endpoint + i, buffer, size, 335 host_endian); 336 if (r < 0) 337 goto err; 338 if (r == 0) { 339 ifp->bNumEndpoints = (uint8_t)i; 340 break;; 341 } 342 343 buffer += r; 344 parsed += r; 345 size -= r; 346 } 347 } 348 349 /* We check to see if it's an alternate to this one */ 350 ifp = (struct libusb_interface_descriptor *) buffer; 351 if (size < LIBUSB_DT_INTERFACE_SIZE || 352 ifp->bDescriptorType != LIBUSB_DT_INTERFACE || 353 ifp->bInterfaceNumber != interface_number) 354 return parsed; 355 } 356 357 return parsed; 358 err: 359 clear_interface(usb_interface); 360 return r; 361 } 362 363 static void clear_configuration(struct libusb_config_descriptor *config) 364 { 365 if (config->interface) { 366 int i; 367 for (i = 0; i < config->bNumInterfaces; i++) 368 clear_interface((struct libusb_interface *) 369 config->interface + i); 370 free((void *) config->interface); 371 } 372 if (config->extra) 373 free((void *) config->extra); 374 } 375 376 static int parse_configuration(struct libusb_context *ctx, 377 struct libusb_config_descriptor *config, unsigned char *buffer, 378 int size, int host_endian) 379 { 380 int i; 381 int r; 382 size_t tmp; 383 struct usb_descriptor_header header; 384 struct libusb_interface *usb_interface; 385 386 if (size < LIBUSB_DT_CONFIG_SIZE) { 387 usbi_err(ctx, "short config descriptor read %d/%d", 388 size, LIBUSB_DT_CONFIG_SIZE); 389 return LIBUSB_ERROR_IO; 390 } 391 392 usbi_parse_descriptor(buffer, "bbwbbbbb", config, host_endian); 393 if (config->bDescriptorType != LIBUSB_DT_CONFIG) { 394 usbi_err(ctx, "unexpected descriptor %x (expected %x)", 395 config->bDescriptorType, LIBUSB_DT_CONFIG); 396 return LIBUSB_ERROR_IO; 397 } 398 if (config->bLength < LIBUSB_DT_CONFIG_SIZE) { 399 usbi_err(ctx, "invalid config bLength (%d)", config->bLength); 400 return LIBUSB_ERROR_IO; 401 } 402 if (config->bLength > size) { 403 usbi_err(ctx, "short config descriptor read %d/%d", 404 size, config->bLength); 405 return LIBUSB_ERROR_IO; 406 } 407 if (config->bNumInterfaces > USB_MAXINTERFACES) { 408 usbi_err(ctx, "too many interfaces (%d)", config->bNumInterfaces); 409 return LIBUSB_ERROR_IO; 410 } 411 412 tmp = config->bNumInterfaces * sizeof(struct libusb_interface); 413 usb_interface = malloc(tmp); 414 config->interface = usb_interface; 415 if (!config->interface) 416 return LIBUSB_ERROR_NO_MEM; 417 418 memset(usb_interface, 0, tmp); 419 buffer += config->bLength; 420 size -= config->bLength; 421 422 config->extra = NULL; 423 config->extra_length = 0; 424 425 for (i = 0; i < config->bNumInterfaces; i++) { 426 int len; 427 unsigned char *begin; 428 429 /* Skip over the rest of the Class Specific or Vendor */ 430 /* Specific descriptors */ 431 begin = buffer; 432 while (size >= DESC_HEADER_LENGTH) { 433 usbi_parse_descriptor(buffer, "bb", &header, 0); 434 435 if (header.bLength < DESC_HEADER_LENGTH) { 436 usbi_err(ctx, 437 "invalid extra config desc len (%d)", 438 header.bLength); 439 r = LIBUSB_ERROR_IO; 440 goto err; 441 } else if (header.bLength > size) { 442 usbi_warn(ctx, 443 "short extra config desc read %d/%d", 444 size, header.bLength); 445 config->bNumInterfaces = (uint8_t)i; 446 return size; 447 } 448 449 /* If we find another "proper" descriptor then we're done */ 450 if ((header.bDescriptorType == LIBUSB_DT_ENDPOINT) || 451 (header.bDescriptorType == LIBUSB_DT_INTERFACE) || 452 (header.bDescriptorType == LIBUSB_DT_CONFIG) || 453 (header.bDescriptorType == LIBUSB_DT_DEVICE)) 454 break; 455 456 usbi_dbg("skipping descriptor 0x%x\n", header.bDescriptorType); 457 buffer += header.bLength; 458 size -= header.bLength; 459 } 460 461 /* Copy any unknown descriptors into a storage area for */ 462 /* drivers to later parse */ 463 len = (int)(buffer - begin); 464 if (len) { 465 /* FIXME: We should realloc and append here */ 466 if (!config->extra_length) { 467 config->extra = malloc(len); 468 if (!config->extra) { 469 r = LIBUSB_ERROR_NO_MEM; 470 goto err; 471 } 472 473 memcpy((unsigned char *) config->extra, begin, len); 474 config->extra_length = len; 475 } 476 } 477 478 r = parse_interface(ctx, usb_interface + i, buffer, size, host_endian); 479 if (r < 0) 480 goto err; 481 if (r == 0) { 482 config->bNumInterfaces = (uint8_t)i; 483 break; 484 } 485 486 buffer += r; 487 size -= r; 488 } 489 490 return size; 491 492 err: 493 clear_configuration(config); 494 return r; 495 } 496 497 static int raw_desc_to_config(struct libusb_context *ctx, 498 unsigned char *buf, int size, int host_endian, 499 struct libusb_config_descriptor **config) 500 { 501 struct libusb_config_descriptor *_config = malloc(sizeof(*_config)); 502 int r; 503 504 if (!_config) 505 return LIBUSB_ERROR_NO_MEM; 506 507 r = parse_configuration(ctx, _config, buf, size, host_endian); 508 if (r < 0) { 509 usbi_err(ctx, "parse_configuration failed with error %d", r); 510 free(_config); 511 return r; 512 } else if (r > 0) { 513 usbi_warn(ctx, "still %d bytes of descriptor data left", r); 514 } 515 516 *config = _config; 517 return LIBUSB_SUCCESS; 518 } 519 520 int usbi_device_cache_descriptor(libusb_device *dev) 521 { 522 int r, host_endian = 0; 523 524 r = usbi_backend->get_device_descriptor(dev, (unsigned char *) &dev->device_descriptor, 525 &host_endian); 526 if (r < 0) 527 return r; 528 529 if (!host_endian) { 530 dev->device_descriptor.bcdUSB = libusb_le16_to_cpu(dev->device_descriptor.bcdUSB); 531 dev->device_descriptor.idVendor = libusb_le16_to_cpu(dev->device_descriptor.idVendor); 532 dev->device_descriptor.idProduct = libusb_le16_to_cpu(dev->device_descriptor.idProduct); 533 dev->device_descriptor.bcdDevice = libusb_le16_to_cpu(dev->device_descriptor.bcdDevice); 534 } 535 536 return LIBUSB_SUCCESS; 537 } 538 539 /** \ingroup desc 540 * Get the USB device descriptor for a given device. 541 * 542 * This is a non-blocking function; the device descriptor is cached in memory. 543 * 544 * Note since libusbx-1.0.16, \ref LIBUSBX_API_VERSION >= 0x01000102, this 545 * function always succeeds. 546 * 547 * \param dev the device 548 * \param desc output location for the descriptor data 549 * \returns 0 on success or a LIBUSB_ERROR code on failure 550 */ 551 int API_EXPORTED libusb_get_device_descriptor(libusb_device *dev, 552 struct libusb_device_descriptor *desc) 553 { 554 usbi_dbg(""); 555 memcpy((unsigned char *) desc, (unsigned char *) &dev->device_descriptor, 556 sizeof (dev->device_descriptor)); 557 return 0; 558 } 559 560 /** \ingroup desc 561 * Get the USB configuration descriptor for the currently active configuration. 562 * This is a non-blocking function which does not involve any requests being 563 * sent to the device. 564 * 565 * \param dev a device 566 * \param config output location for the USB configuration descriptor. Only 567 * valid if 0 was returned. Must be freed with libusb_free_config_descriptor() 568 * after use. 569 * \returns 0 on success 570 * \returns LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state 571 * \returns another LIBUSB_ERROR code on error 572 * \see libusb_get_config_descriptor 573 */ 574 int API_EXPORTED libusb_get_active_config_descriptor(libusb_device *dev, 575 struct libusb_config_descriptor **config) 576 { 577 struct libusb_config_descriptor _config; 578 unsigned char tmp[LIBUSB_DT_CONFIG_SIZE]; 579 unsigned char *buf = NULL; 580 int host_endian = 0; 581 int r; 582 583 r = usbi_backend->get_active_config_descriptor(dev, tmp, 584 LIBUSB_DT_CONFIG_SIZE, &host_endian); 585 if (r < 0) 586 return r; 587 if (r < LIBUSB_DT_CONFIG_SIZE) { 588 usbi_err(dev->ctx, "short config descriptor read %d/%d", 589 r, LIBUSB_DT_CONFIG_SIZE); 590 return LIBUSB_ERROR_IO; 591 } 592 593 usbi_parse_descriptor(tmp, "bbw", &_config, host_endian); 594 buf = malloc(_config.wTotalLength); 595 if (!buf) 596 return LIBUSB_ERROR_NO_MEM; 597 598 r = usbi_backend->get_active_config_descriptor(dev, buf, 599 _config.wTotalLength, &host_endian); 600 if (r >= 0) 601 r = raw_desc_to_config(dev->ctx, buf, r, host_endian, config); 602 603 free(buf); 604 return r; 605 } 606 607 /** \ingroup desc 608 * Get a USB configuration descriptor based on its index. 609 * This is a non-blocking function which does not involve any requests being 610 * sent to the device. 611 * 612 * \param dev a device 613 * \param config_index the index of the configuration you wish to retrieve 614 * \param config output location for the USB configuration descriptor. Only 615 * valid if 0 was returned. Must be freed with libusb_free_config_descriptor() 616 * after use. 617 * \returns 0 on success 618 * \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist 619 * \returns another LIBUSB_ERROR code on error 620 * \see libusb_get_active_config_descriptor() 621 * \see libusb_get_config_descriptor_by_value() 622 */ 623 int API_EXPORTED libusb_get_config_descriptor(libusb_device *dev, 624 uint8_t config_index, struct libusb_config_descriptor **config) 625 { 626 struct libusb_config_descriptor _config; 627 unsigned char tmp[LIBUSB_DT_CONFIG_SIZE]; 628 unsigned char *buf = NULL; 629 int host_endian = 0; 630 int r; 631 632 usbi_dbg("index %d", config_index); 633 if (config_index >= dev->num_configurations) 634 return LIBUSB_ERROR_NOT_FOUND; 635 636 r = usbi_backend->get_config_descriptor(dev, config_index, tmp, 637 LIBUSB_DT_CONFIG_SIZE, &host_endian); 638 if (r < 0) 639 return r; 640 if (r < LIBUSB_DT_CONFIG_SIZE) { 641 usbi_err(dev->ctx, "short config descriptor read %d/%d", 642 r, LIBUSB_DT_CONFIG_SIZE); 643 return LIBUSB_ERROR_IO; 644 } 645 646 usbi_parse_descriptor(tmp, "bbw", &_config, host_endian); 647 buf = malloc(_config.wTotalLength); 648 if (!buf) 649 return LIBUSB_ERROR_NO_MEM; 650 651 r = usbi_backend->get_config_descriptor(dev, config_index, buf, 652 _config.wTotalLength, &host_endian); 653 if (r >= 0) 654 r = raw_desc_to_config(dev->ctx, buf, r, host_endian, config); 655 656 free(buf); 657 return r; 658 } 659 660 /* iterate through all configurations, returning the index of the configuration 661 * matching a specific bConfigurationValue in the idx output parameter, or -1 662 * if the config was not found. 663 * returns 0 or a LIBUSB_ERROR code 664 */ 665 int usbi_get_config_index_by_value(struct libusb_device *dev, 666 uint8_t bConfigurationValue, int *idx) 667 { 668 uint8_t i; 669 670 usbi_dbg("value %d", bConfigurationValue); 671 for (i = 0; i < dev->num_configurations; i++) { 672 unsigned char tmp[6]; 673 int host_endian; 674 int r = usbi_backend->get_config_descriptor(dev, i, tmp, sizeof(tmp), 675 &host_endian); 676 if (r < 0) 677 return r; 678 if (tmp[5] == bConfigurationValue) { 679 *idx = i; 680 return 0; 681 } 682 } 683 684 *idx = -1; 685 return 0; 686 } 687 688 /** \ingroup desc 689 * Get a USB configuration descriptor with a specific bConfigurationValue. 690 * This is a non-blocking function which does not involve any requests being 691 * sent to the device. 692 * 693 * \param dev a device 694 * \param bConfigurationValue the bConfigurationValue of the configuration you 695 * wish to retrieve 696 * \param config output location for the USB configuration descriptor. Only 697 * valid if 0 was returned. Must be freed with libusb_free_config_descriptor() 698 * after use. 699 * \returns 0 on success 700 * \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist 701 * \returns another LIBUSB_ERROR code on error 702 * \see libusb_get_active_config_descriptor() 703 * \see libusb_get_config_descriptor() 704 */ 705 int API_EXPORTED libusb_get_config_descriptor_by_value(libusb_device *dev, 706 uint8_t bConfigurationValue, struct libusb_config_descriptor **config) 707 { 708 int r, idx, host_endian; 709 unsigned char *buf = NULL; 710 711 if (usbi_backend->get_config_descriptor_by_value) { 712 r = usbi_backend->get_config_descriptor_by_value(dev, 713 bConfigurationValue, &buf, &host_endian); 714 if (r < 0) 715 return r; 716 return raw_desc_to_config(dev->ctx, buf, r, host_endian, config); 717 } 718 719 r = usbi_get_config_index_by_value(dev, bConfigurationValue, &idx); 720 if (r < 0) 721 return r; 722 else if (idx == -1) 723 return LIBUSB_ERROR_NOT_FOUND; 724 else 725 return libusb_get_config_descriptor(dev, (uint8_t) idx, config); 726 } 727 728 /** \ingroup desc 729 * Free a configuration descriptor obtained from 730 * libusb_get_active_config_descriptor() or libusb_get_config_descriptor(). 731 * It is safe to call this function with a NULL config parameter, in which 732 * case the function simply returns. 733 * 734 * \param config the configuration descriptor to free 735 */ 736 void API_EXPORTED libusb_free_config_descriptor( 737 struct libusb_config_descriptor *config) 738 { 739 if (!config) 740 return; 741 742 clear_configuration(config); 743 free(config); 744 } 745 746 /** \ingroup desc 747 * Get an endpoints superspeed endpoint companion descriptor (if any) 748 * 749 * \param ctx the context to operate on, or NULL for the default context 750 * \param endpoint endpoint descriptor from which to get the superspeed 751 * endpoint companion descriptor 752 * \param ep_comp output location for the superspeed endpoint companion 753 * descriptor. Only valid if 0 was returned. Must be freed with 754 * libusb_free_ss_endpoint_companion_descriptor() after use. 755 * \returns 0 on success 756 * \returns LIBUSB_ERROR_NOT_FOUND if the configuration does not exist 757 * \returns another LIBUSB_ERROR code on error 758 */ 759 int API_EXPORTED libusb_get_ss_endpoint_companion_descriptor( 760 struct libusb_context *ctx, 761 const struct libusb_endpoint_descriptor *endpoint, 762 struct libusb_ss_endpoint_companion_descriptor **ep_comp) 763 { 764 struct usb_descriptor_header header; 765 int size = endpoint->extra_length; 766 const unsigned char *buffer = endpoint->extra; 767 768 *ep_comp = NULL; 769 770 while (size >= DESC_HEADER_LENGTH) { 771 usbi_parse_descriptor(buffer, "bb", &header, 0); 772 if (header.bLength < 2 || header.bLength > size) { 773 usbi_err(ctx, "invalid descriptor length %d", 774 header.bLength); 775 return LIBUSB_ERROR_IO; 776 } 777 if (header.bDescriptorType != LIBUSB_DT_SS_ENDPOINT_COMPANION) { 778 buffer += header.bLength; 779 size -= header.bLength; 780 continue; 781 } 782 if (header.bLength < LIBUSB_DT_SS_ENDPOINT_COMPANION_SIZE) { 783 usbi_err(ctx, "invalid ss-ep-comp-desc length %d", 784 header.bLength); 785 return LIBUSB_ERROR_IO; 786 } 787 *ep_comp = malloc(sizeof(**ep_comp)); 788 if (*ep_comp == NULL) 789 return LIBUSB_ERROR_NO_MEM; 790 usbi_parse_descriptor(buffer, "bbbbw", *ep_comp, 0); 791 return LIBUSB_SUCCESS; 792 } 793 return LIBUSB_ERROR_NOT_FOUND; 794 } 795 796 /** \ingroup desc 797 * Free a superspeed endpoint companion descriptor obtained from 798 * libusb_get_ss_endpoint_companion_descriptor(). 799 * It is safe to call this function with a NULL ep_comp parameter, in which 800 * case the function simply returns. 801 * 802 * \param ep_comp the superspeed endpoint companion descriptor to free 803 */ 804 void API_EXPORTED libusb_free_ss_endpoint_companion_descriptor( 805 struct libusb_ss_endpoint_companion_descriptor *ep_comp) 806 { 807 free(ep_comp); 808 } 809 810 static int parse_bos(struct libusb_context *ctx, 811 struct libusb_bos_descriptor **bos, 812 unsigned char *buffer, int size, int host_endian) 813 { 814 struct libusb_bos_descriptor bos_header, *_bos; 815 struct libusb_bos_dev_capability_descriptor dev_cap; 816 int i; 817 818 if (size < LIBUSB_DT_BOS_SIZE) { 819 usbi_err(ctx, "short bos descriptor read %d/%d", 820 size, LIBUSB_DT_BOS_SIZE); 821 return LIBUSB_ERROR_IO; 822 } 823 824 usbi_parse_descriptor(buffer, "bbwb", &bos_header, host_endian); 825 if (bos_header.bDescriptorType != LIBUSB_DT_BOS) { 826 usbi_err(ctx, "unexpected descriptor %x (expected %x)", 827 bos_header.bDescriptorType, LIBUSB_DT_BOS); 828 return LIBUSB_ERROR_IO; 829 } 830 if (bos_header.bLength < LIBUSB_DT_BOS_SIZE) { 831 usbi_err(ctx, "invalid bos bLength (%d)", bos_header.bLength); 832 return LIBUSB_ERROR_IO; 833 } 834 if (bos_header.bLength > size) { 835 usbi_err(ctx, "short bos descriptor read %d/%d", 836 size, bos_header.bLength); 837 return LIBUSB_ERROR_IO; 838 } 839 840 _bos = calloc (1, 841 sizeof(*_bos) + bos_header.bNumDeviceCaps * sizeof(void *)); 842 if (!_bos) 843 return LIBUSB_ERROR_NO_MEM; 844 845 usbi_parse_descriptor(buffer, "bbwb", _bos, host_endian); 846 buffer += bos_header.bLength; 847 size -= bos_header.bLength; 848 849 /* Get the device capability descriptors */ 850 for (i = 0; i < bos_header.bNumDeviceCaps; i++) { 851 if (size < LIBUSB_DT_DEVICE_CAPABILITY_SIZE) { 852 usbi_warn(ctx, "short dev-cap descriptor read %d/%d", 853 size, LIBUSB_DT_DEVICE_CAPABILITY_SIZE); 854 break; 855 } 856 usbi_parse_descriptor(buffer, "bbb", &dev_cap, host_endian); 857 if (dev_cap.bDescriptorType != LIBUSB_DT_DEVICE_CAPABILITY) { 858 usbi_warn(ctx, "unexpected descriptor %x (expected %x)", 859 dev_cap.bDescriptorType, LIBUSB_DT_DEVICE_CAPABILITY); 860 break; 861 } 862 if (dev_cap.bLength < LIBUSB_DT_DEVICE_CAPABILITY_SIZE) { 863 usbi_err(ctx, "invalid dev-cap bLength (%d)", 864 dev_cap.bLength); 865 libusb_free_bos_descriptor(_bos); 866 return LIBUSB_ERROR_IO; 867 } 868 if (dev_cap.bLength > size) { 869 usbi_warn(ctx, "short dev-cap descriptor read %d/%d", 870 size, dev_cap.bLength); 871 break; 872 } 873 874 _bos->dev_capability[i] = malloc(dev_cap.bLength); 875 if (!_bos->dev_capability[i]) { 876 libusb_free_bos_descriptor(_bos); 877 return LIBUSB_ERROR_NO_MEM; 878 } 879 memcpy(_bos->dev_capability[i], buffer, dev_cap.bLength); 880 buffer += dev_cap.bLength; 881 size -= dev_cap.bLength; 882 } 883 _bos->bNumDeviceCaps = (uint8_t)i; 884 *bos = _bos; 885 886 return LIBUSB_SUCCESS; 887 } 888 889 /** \ingroup desc 890 * Get a Binary Object Store (BOS) descriptor 891 * This is a BLOCKING function, which will send requests to the device. 892 * 893 * \param handle the handle of an open libusb device 894 * \param bos output location for the BOS descriptor. Only valid if 0 was returned. 895 * Must be freed with \ref libusb_free_bos_descriptor() after use. 896 * \returns 0 on success 897 * \returns LIBUSB_ERROR_NOT_FOUND if the device doesn't have a BOS descriptor 898 * \returns another LIBUSB_ERROR code on error 899 */ 900 int API_EXPORTED libusb_get_bos_descriptor(libusb_device_handle *handle, 901 struct libusb_bos_descriptor **bos) 902 { 903 struct libusb_bos_descriptor _bos; 904 uint8_t bos_header[LIBUSB_DT_BOS_SIZE] = {0}; 905 unsigned char *bos_data = NULL; 906 const int host_endian = 0; 907 int r; 908 909 /* Read the BOS. This generates 2 requests on the bus, 910 * one for the header, and one for the full BOS */ 911 r = libusb_get_descriptor(handle, LIBUSB_DT_BOS, 0, bos_header, 912 LIBUSB_DT_BOS_SIZE); 913 if (r < 0) { 914 if (r != LIBUSB_ERROR_PIPE) 915 usbi_err(handle->dev->ctx, "failed to read BOS (%d)", r); 916 return r; 917 } 918 if (r < LIBUSB_DT_BOS_SIZE) { 919 usbi_err(handle->dev->ctx, "short BOS read %d/%d", 920 r, LIBUSB_DT_BOS_SIZE); 921 return LIBUSB_ERROR_IO; 922 } 923 924 usbi_parse_descriptor(bos_header, "bbwb", &_bos, host_endian); 925 usbi_dbg("found BOS descriptor: size %d bytes, %d capabilities", 926 _bos.wTotalLength, _bos.bNumDeviceCaps); 927 bos_data = calloc(_bos.wTotalLength, 1); 928 if (bos_data == NULL) 929 return LIBUSB_ERROR_NO_MEM; 930 931 r = libusb_get_descriptor(handle, LIBUSB_DT_BOS, 0, bos_data, 932 _bos.wTotalLength); 933 if (r >= 0) 934 r = parse_bos(handle->dev->ctx, bos, bos_data, r, host_endian); 935 else 936 usbi_err(handle->dev->ctx, "failed to read BOS (%d)", r); 937 938 free(bos_data); 939 return r; 940 } 941 942 /** \ingroup desc 943 * Free a BOS descriptor obtained from libusb_get_bos_descriptor(). 944 * It is safe to call this function with a NULL bos parameter, in which 945 * case the function simply returns. 946 * 947 * \param bos the BOS descriptor to free 948 */ 949 void API_EXPORTED libusb_free_bos_descriptor(struct libusb_bos_descriptor *bos) 950 { 951 int i; 952 953 if (!bos) 954 return; 955 956 for (i = 0; i < bos->bNumDeviceCaps; i++) 957 free(bos->dev_capability[i]); 958 free(bos); 959 } 960 961 /** \ingroup desc 962 * Get an USB 2.0 Extension descriptor 963 * 964 * \param ctx the context to operate on, or NULL for the default context 965 * \param dev_cap Device Capability descriptor with a bDevCapabilityType of 966 * \ref libusb_capability_type::LIBUSB_BT_USB_2_0_EXTENSION 967 * LIBUSB_BT_USB_2_0_EXTENSION 968 * \param usb_2_0_extension output location for the USB 2.0 Extension 969 * descriptor. Only valid if 0 was returned. Must be freed with 970 * libusb_free_usb_2_0_extension_descriptor() after use. 971 * \returns 0 on success 972 * \returns a LIBUSB_ERROR code on error 973 */ 974 int API_EXPORTED libusb_get_usb_2_0_extension_descriptor( 975 struct libusb_context *ctx, 976 struct libusb_bos_dev_capability_descriptor *dev_cap, 977 struct libusb_usb_2_0_extension_descriptor **usb_2_0_extension) 978 { 979 struct libusb_usb_2_0_extension_descriptor *_usb_2_0_extension; 980 const int host_endian = 0; 981 982 if (dev_cap->bDevCapabilityType != LIBUSB_BT_USB_2_0_EXTENSION) { 983 usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)", 984 dev_cap->bDevCapabilityType, 985 LIBUSB_BT_USB_2_0_EXTENSION); 986 return LIBUSB_ERROR_INVALID_PARAM; 987 } 988 if (dev_cap->bLength < LIBUSB_BT_USB_2_0_EXTENSION_SIZE) { 989 usbi_err(ctx, "short dev-cap descriptor read %d/%d", 990 dev_cap->bLength, LIBUSB_BT_USB_2_0_EXTENSION_SIZE); 991 return LIBUSB_ERROR_IO; 992 } 993 994 _usb_2_0_extension = malloc(sizeof(*_usb_2_0_extension)); 995 if (!_usb_2_0_extension) 996 return LIBUSB_ERROR_NO_MEM; 997 998 usbi_parse_descriptor((unsigned char *)dev_cap, "bbbd", 999 _usb_2_0_extension, host_endian); 1000 1001 *usb_2_0_extension = _usb_2_0_extension; 1002 return LIBUSB_SUCCESS; 1003 } 1004 1005 /** \ingroup desc 1006 * Free a USB 2.0 Extension descriptor obtained from 1007 * libusb_get_usb_2_0_extension_descriptor(). 1008 * It is safe to call this function with a NULL usb_2_0_extension parameter, 1009 * in which case the function simply returns. 1010 * 1011 * \param usb_2_0_extension the USB 2.0 Extension descriptor to free 1012 */ 1013 void API_EXPORTED libusb_free_usb_2_0_extension_descriptor( 1014 struct libusb_usb_2_0_extension_descriptor *usb_2_0_extension) 1015 { 1016 free(usb_2_0_extension); 1017 } 1018 1019 /** \ingroup desc 1020 * Get a SuperSpeed USB Device Capability descriptor 1021 * 1022 * \param ctx the context to operate on, or NULL for the default context 1023 * \param dev_cap Device Capability descriptor with a bDevCapabilityType of 1024 * \ref libusb_capability_type::LIBUSB_BT_SS_USB_DEVICE_CAPABILITY 1025 * LIBUSB_BT_SS_USB_DEVICE_CAPABILITY 1026 * \param ss_usb_device_cap output location for the SuperSpeed USB Device 1027 * Capability descriptor. Only valid if 0 was returned. Must be freed with 1028 * libusb_free_ss_usb_device_capability_descriptor() after use. 1029 * \returns 0 on success 1030 * \returns a LIBUSB_ERROR code on error 1031 */ 1032 int API_EXPORTED libusb_get_ss_usb_device_capability_descriptor( 1033 struct libusb_context *ctx, 1034 struct libusb_bos_dev_capability_descriptor *dev_cap, 1035 struct libusb_ss_usb_device_capability_descriptor **ss_usb_device_cap) 1036 { 1037 struct libusb_ss_usb_device_capability_descriptor *_ss_usb_device_cap; 1038 const int host_endian = 0; 1039 1040 if (dev_cap->bDevCapabilityType != LIBUSB_BT_SS_USB_DEVICE_CAPABILITY) { 1041 usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)", 1042 dev_cap->bDevCapabilityType, 1043 LIBUSB_BT_SS_USB_DEVICE_CAPABILITY); 1044 return LIBUSB_ERROR_INVALID_PARAM; 1045 } 1046 if (dev_cap->bLength < LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE) { 1047 usbi_err(ctx, "short dev-cap descriptor read %d/%d", 1048 dev_cap->bLength, LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE); 1049 return LIBUSB_ERROR_IO; 1050 } 1051 1052 _ss_usb_device_cap = malloc(sizeof(*_ss_usb_device_cap)); 1053 if (!_ss_usb_device_cap) 1054 return LIBUSB_ERROR_NO_MEM; 1055 1056 usbi_parse_descriptor((unsigned char *)dev_cap, "bbbbwbbw", 1057 _ss_usb_device_cap, host_endian); 1058 1059 *ss_usb_device_cap = _ss_usb_device_cap; 1060 return LIBUSB_SUCCESS; 1061 } 1062 1063 /** \ingroup desc 1064 * Free a SuperSpeed USB Device Capability descriptor obtained from 1065 * libusb_get_ss_usb_device_capability_descriptor(). 1066 * It is safe to call this function with a NULL ss_usb_device_cap 1067 * parameter, in which case the function simply returns. 1068 * 1069 * \param ss_usb_device_cap the USB 2.0 Extension descriptor to free 1070 */ 1071 void API_EXPORTED libusb_free_ss_usb_device_capability_descriptor( 1072 struct libusb_ss_usb_device_capability_descriptor *ss_usb_device_cap) 1073 { 1074 free(ss_usb_device_cap); 1075 } 1076 1077 /** \ingroup desc 1078 * Get a Container ID descriptor 1079 * 1080 * \param ctx the context to operate on, or NULL for the default context 1081 * \param dev_cap Device Capability descriptor with a bDevCapabilityType of 1082 * \ref libusb_capability_type::LIBUSB_BT_CONTAINER_ID 1083 * LIBUSB_BT_CONTAINER_ID 1084 * \param container_id output location for the Container ID descriptor. 1085 * Only valid if 0 was returned. Must be freed with 1086 * libusb_free_container_id_descriptor() after use. 1087 * \returns 0 on success 1088 * \returns a LIBUSB_ERROR code on error 1089 */ 1090 int API_EXPORTED libusb_get_container_id_descriptor(struct libusb_context *ctx, 1091 struct libusb_bos_dev_capability_descriptor *dev_cap, 1092 struct libusb_container_id_descriptor **container_id) 1093 { 1094 struct libusb_container_id_descriptor *_container_id; 1095 const int host_endian = 0; 1096 1097 if (dev_cap->bDevCapabilityType != LIBUSB_BT_CONTAINER_ID) { 1098 usbi_err(ctx, "unexpected bDevCapabilityType %x (expected %x)", 1099 dev_cap->bDevCapabilityType, 1100 LIBUSB_BT_CONTAINER_ID); 1101 return LIBUSB_ERROR_INVALID_PARAM; 1102 } 1103 if (dev_cap->bLength < LIBUSB_BT_CONTAINER_ID_SIZE) { 1104 usbi_err(ctx, "short dev-cap descriptor read %d/%d", 1105 dev_cap->bLength, LIBUSB_BT_CONTAINER_ID_SIZE); 1106 return LIBUSB_ERROR_IO; 1107 } 1108 1109 _container_id = malloc(sizeof(*_container_id)); 1110 if (!_container_id) 1111 return LIBUSB_ERROR_NO_MEM; 1112 1113 usbi_parse_descriptor((unsigned char *)dev_cap, "bbbbu", 1114 _container_id, host_endian); 1115 1116 *container_id = _container_id; 1117 return LIBUSB_SUCCESS; 1118 } 1119 1120 /** \ingroup desc 1121 * Free a Container ID descriptor obtained from 1122 * libusb_get_container_id_descriptor(). 1123 * It is safe to call this function with a NULL container_id parameter, 1124 * in which case the function simply returns. 1125 * 1126 * \param container_id the USB 2.0 Extension descriptor to free 1127 */ 1128 void API_EXPORTED libusb_free_container_id_descriptor( 1129 struct libusb_container_id_descriptor *container_id) 1130 { 1131 free(container_id); 1132 } 1133 1134 /** \ingroup desc 1135 * Retrieve a string descriptor in C style ASCII. 1136 * 1137 * Wrapper around libusb_get_string_descriptor(). Uses the first language 1138 * supported by the device. 1139 * 1140 * \param dev a device handle 1141 * \param desc_index the index of the descriptor to retrieve 1142 * \param data output buffer for ASCII string descriptor 1143 * \param length size of data buffer 1144 * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure 1145 */ 1146 int API_EXPORTED libusb_get_string_descriptor_ascii(libusb_device_handle *dev, 1147 uint8_t desc_index, unsigned char *data, int length) 1148 { 1149 unsigned char tbuf[255]; /* Some devices choke on size > 255 */ 1150 int r, si, di; 1151 uint16_t langid; 1152 1153 /* Asking for the zero'th index is special - it returns a string 1154 * descriptor that contains all the language IDs supported by the 1155 * device. Typically there aren't many - often only one. Language 1156 * IDs are 16 bit numbers, and they start at the third byte in the 1157 * descriptor. There's also no point in trying to read descriptor 0 1158 * with this function. See USB 2.0 specification section 9.6.7 for 1159 * more information. 1160 */ 1161 1162 if (desc_index == 0) 1163 return LIBUSB_ERROR_INVALID_PARAM; 1164 1165 r = libusb_get_string_descriptor(dev, 0, 0, tbuf, sizeof(tbuf)); 1166 if (r < 0) 1167 return r; 1168 1169 if (r < 4) 1170 return LIBUSB_ERROR_IO; 1171 1172 langid = tbuf[2] | (tbuf[3] << 8); 1173 1174 r = libusb_get_string_descriptor(dev, desc_index, langid, tbuf, 1175 sizeof(tbuf)); 1176 if (r < 0) 1177 return r; 1178 1179 if (tbuf[1] != LIBUSB_DT_STRING) 1180 return LIBUSB_ERROR_IO; 1181 1182 if (tbuf[0] > r) 1183 return LIBUSB_ERROR_IO; 1184 1185 for (di = 0, si = 2; si < tbuf[0]; si += 2) { 1186 if (di >= (length - 1)) 1187 break; 1188 1189 if ((tbuf[si] & 0x80) || (tbuf[si + 1])) /* non-ASCII */ 1190 data[di++] = '?'; 1191 else 1192 data[di++] = tbuf[si]; 1193 } 1194 1195 data[di] = 0; 1196 return di; 1197 } 1198
