1 #include <machine/inttypes.h> 2 #include <sys/ioctl.h> 3 #include <sys/param.h> 4 #include <sys/stat.h> 5 #include <stdio.h> 6 #include <string.h> 7 #include <stdlib.h> 8 #include <dirent.h> 9 #include <errno.h> 10 #include <libdm.h> 11 #include <fcntl.h> 12 #include <uuid.h> 13 14 #include "internal.h" 15 #include "luks.h" 16 17 #define DEVICE_DIR "/dev" 18 #define DM_UUID_LEN 129 19 #define DM_UUID_PREFIX "CRYPT-" 20 #define DM_UUID_PREFIX_LEN 6 21 #define DM_CRYPT_TARGET "crypt" 22 #define RETRY_COUNT 5 23 24 /* Set if dm-crypt version was probed */ 25 static int _dm_crypt_checked = 0; 26 static int _dm_crypt_wipe_key_supported = 0; 27 28 static int _dm_use_count = 0; 29 static struct crypt_device *_context = NULL; 30 31 /* Compatibility for old device-mapper without udev support */ 32 #ifndef HAVE_DM_TASK_SET_COOKIE 33 #define CRYPT_TEMP_UDEV_FLAGS 0 34 #else 35 #define CRYPT_TEMP_UDEV_FLAGS DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \ 36 DM_UDEV_DISABLE_DISK_RULES_FLAG | \ 37 DM_UDEV_DISABLE_OTHER_RULES_FLAG 38 #endif 39 40 static int _dm_use_udev() 41 { 42 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */ 43 return dm_udev_get_sync_support(); 44 #else 45 return 0; 46 #endif 47 } 48 49 static void set_dm_error(int level, const char *file, int line, 50 const char *f, ...) 51 { 52 char *msg = NULL; 53 va_list va; 54 55 va_start(va, f); 56 if (vasprintf(&msg, f, va) > 0) { 57 if (level < 4) { 58 log_err(_context, msg); 59 log_err(_context, "\n"); 60 } else 61 log_dbg(msg); 62 } 63 free(msg); 64 va_end(va); 65 } 66 67 static int _dm_simple(int task, const char *name, int udev_wait); 68 69 static void _dm_set_crypt_compat(int maj, int min, int patch) 70 { 71 log_dbg("Detected dm-crypt target of version %i.%i.%i.", maj, min, patch); 72 73 if (maj >= 1 && min >=2) 74 _dm_crypt_wipe_key_supported = 1; 75 else 76 log_dbg("Suspend and resume disabled, no wipe key support."); 77 78 _dm_crypt_checked = 1; 79 } 80 81 static int _dm_check_versions(void) 82 { 83 struct dm_task *dmt; 84 struct dm_versions *target, *last_target; 85 86 if (_dm_crypt_checked) 87 return 1; 88 89 if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS))) 90 return 0; 91 92 if (!dm_task_run(dmt)) { 93 dm_task_destroy(dmt); 94 return 0; 95 } 96 97 target = dm_task_get_versions(dmt); 98 do { 99 last_target = target; 100 if (!strcmp(DM_CRYPT_TARGET, target->name)) { 101 _dm_set_crypt_compat((int)target->version[0], 102 (int)target->version[1], 103 (int)target->version[2]); 104 } 105 target = (void *) target + target->next; 106 } while (last_target != target); 107 108 dm_task_destroy(dmt); 109 return 1; 110 } 111 112 int dm_init(struct crypt_device *context, int check_kernel) 113 { 114 if (!_dm_use_count++) { 115 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.", 116 check_kernel ? "" : " (NO kernel check requested)", 117 _dm_use_udev() ? "en" : "dis"); 118 if (check_kernel && !_dm_check_versions()) { 119 log_err(context, _("Cannot initialize device-mapper. Is dm kernel module loaded?\n")); 120 return -1; 121 } 122 if (getuid() || geteuid()) 123 log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable.")); 124 dm_log_init(set_dm_error); 125 dm_log_init_verbose(10); 126 } 127 128 // FIXME: global context is not safe 129 if (context) 130 _context = context; 131 132 return 1; /* unsafe memory */ 133 } 134 135 void dm_exit(void) 136 { 137 if (_dm_use_count && (!--_dm_use_count)) { 138 log_dbg("Releasing device-mapper backend."); 139 dm_log_init_verbose(0); 140 dm_log_init(NULL); 141 dm_lib_release(); 142 _context = NULL; 143 } 144 } 145 146 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level) 147 { 148 struct dirent *entry; 149 struct stat st; 150 char *ptr; 151 char *result = NULL; 152 DIR *dir; 153 int space; 154 155 /* Ignore strange nested directories */ 156 if (dir_level > max_level) 157 return NULL; 158 159 path[PATH_MAX - 1] = '\0'; 160 ptr = path + strlen(path); 161 *ptr++ = '/'; 162 *ptr = '\0'; 163 space = PATH_MAX - (ptr - path); 164 165 dir = opendir(path); 166 if (!dir) 167 return NULL; 168 169 while((entry = readdir(dir))) { 170 if (entry->d_name[0] == '.' || 171 !strncmp(entry->d_name, "..", 2)) 172 continue; 173 174 strncpy(ptr, entry->d_name, space); 175 if (stat(path, &st) < 0) 176 continue; 177 178 if (S_ISDIR(st.st_mode)) { 179 result = __lookup_dev(path, dev, dir_level + 1, max_level); 180 if (result) 181 break; 182 } else if (S_ISBLK(st.st_mode)) { 183 /* workaround: ignore dm-X devices, these are internal kernel names */ 184 if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3)) 185 continue; 186 if (st.st_rdev == dev) { 187 result = strdup(path); 188 break; 189 } 190 } 191 } 192 193 closedir(dir); 194 return result; 195 } 196 197 static char *lookup_dev(const char *dev_id) 198 { 199 uint32_t major, minor; 200 dev_t dev; 201 char *result = NULL, buf[PATH_MAX + 1]; 202 203 if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2) 204 return NULL; 205 206 dev = makedev(major, minor); 207 strncpy(buf, DEVICE_DIR, PATH_MAX); 208 buf[PATH_MAX] = '\0'; 209 210 /* First try low level device */ 211 if ((result = __lookup_dev(buf, dev, 0, 0))) 212 return result; 213 214 /* If it is dm, try DM dir */ 215 if (dm_is_dm_major(major)) { 216 strncpy(buf, dm_dir(), PATH_MAX); 217 if ((result = __lookup_dev(buf, dev, 0, 0))) 218 return result; 219 } 220 221 strncpy(buf, DEVICE_DIR, PATH_MAX); 222 result = __lookup_dev(buf, dev, 0, 4); 223 224 /* If not found, return NULL */ 225 return result; 226 } 227 228 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead) 229 { 230 int fd, r = 0; 231 long read_ahead_long; 232 233 if ((fd = open(dev, O_RDONLY)) < 0) 234 return 0; 235 236 r = 0; 237 //r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1; 238 close(fd); 239 240 if (r) 241 *read_ahead = (uint32_t) read_ahead_long; 242 243 return r; 244 } 245 246 static void hex_key(char *hexkey, size_t key_size, const char *key) 247 { 248 int i; 249 250 for(i = 0; i < key_size; i++) 251 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]); 252 } 253 254 static char *get_params(const char *device, uint64_t skip, uint64_t offset, 255 const char *cipher, size_t key_size, const char *key) 256 { 257 char *params; 258 char *hexkey; 259 260 hexkey = safe_alloc(key_size * 2 + 1); 261 if (!hexkey) 262 return NULL; 263 264 hex_key(hexkey, key_size, key); 265 266 params = safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64); 267 if (!params) 268 goto out; 269 270 sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64, 271 cipher, hexkey, skip, device, offset); 272 273 out: 274 safe_free(hexkey); 275 return params; 276 } 277 278 /* DM helpers */ 279 static int _dm_simple(int task, const char *name, int udev_wait) 280 { 281 int r = 0; 282 struct dm_task *dmt; 283 uint32_t cookie = 0; 284 285 if (!_dm_use_udev()) 286 udev_wait = 0; 287 288 if (!(dmt = dm_task_create(task))) 289 return 0; 290 291 if (name && !dm_task_set_name(dmt, name)) 292 goto out; 293 294 if (udev_wait && !dm_task_set_cookie(dmt, &cookie, 0)) 295 goto out; 296 297 r = dm_task_run(dmt); 298 299 if (udev_wait) 300 (void)dm_udev_wait(cookie); 301 302 out: 303 dm_task_destroy(dmt); 304 return r; 305 } 306 307 static int _error_device(const char *name, size_t size) 308 { 309 struct dm_task *dmt; 310 int r = 0; 311 312 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD))) 313 return 0; 314 315 if (!dm_task_set_name(dmt, name)) 316 goto error; 317 318 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", "")) 319 goto error; 320 321 if (!dm_task_set_ro(dmt)) 322 goto error; 323 324 if (!dm_task_no_open_count(dmt)) 325 goto error; 326 327 if (!dm_task_run(dmt)) 328 goto error; 329 330 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) { 331 _dm_simple(DM_DEVICE_CLEAR, name, 0); 332 goto error; 333 } 334 335 r = 1; 336 337 error: 338 dm_task_destroy(dmt); 339 return r; 340 } 341 342 int dm_remove_device(const char *name, int force, uint64_t size) 343 { 344 int r = -EINVAL; 345 int retries = force ? RETRY_COUNT : 1; 346 int error_target = 0; 347 348 if (!name || (force && !size)) 349 return -EINVAL; 350 351 do { 352 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL; 353 if (--retries && r) { 354 log_dbg("WARNING: other process locked internal device %s, %s.", 355 name, retries ? "retrying remove" : "giving up"); 356 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG)) 357 debug_processes_using_device(name); 358 sleep(1); 359 if (force && !error_target) { 360 /* If force flag is set, replace device with error, read-only target. 361 * it should stop processes from reading it and also removed underlying 362 * device from mapping, so it is usable again. 363 * Force flag should be used only for temporary devices, which are 364 * intended to work inside cryptsetup only! 365 * Anyway, if some process try to read temporary cryptsetup device, 366 * it is bug - no other process should try touch it (e.g. udev). 367 */ 368 _error_device(name, size); 369 error_target = 1; 370 } 371 } 372 } while (r == -EINVAL && retries); 373 374 dm_task_update_nodes(); 375 376 return r; 377 } 378 379 #define UUID_LEN 37 /* 36 + \0, libuuid ... */ 380 /* 381 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name> 382 * CRYPT-PLAIN-name 383 * CRYPT-LUKS1-00000000000000000000000000000000-name 384 * CRYPT-TEMP-name 385 */ 386 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen) 387 { 388 char *ptr, uuid2[UUID_LEN] = {0}; 389 uuid_t uu; 390 int i = 0; 391 uint32_t ret; 392 393 /* Remove '-' chars */ 394 if (uuid) { 395 uuid_from_string(uuid, &uu, &ret); 396 if (ret != uuid_s_ok) { 397 printf("error in uuid_from_string(%s), err = %d\n", uuid, ret); 398 for (ptr = uuid2, i = 0; i < UUID_LEN; i++) { 399 if (uuid[i] != '-') { 400 *ptr = uuid[i]; 401 ptr++; 402 } 403 } 404 } 405 } 406 407 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s", 408 type ?: "", type ? "-" : "", 409 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "", 410 name); 411 412 log_dbg("DM-UUID is %s", buf); 413 if (i >= buflen) 414 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name); 415 } 416 417 int dm_create_device(const char *name, 418 const char *device, 419 const char *cipher, 420 const char *type, 421 const char *uuid, 422 uint64_t size, 423 uint64_t skip, 424 uint64_t offset, 425 size_t key_size, 426 const char *key, 427 int read_only, 428 int reload) 429 { 430 struct dm_task *dmt = NULL; 431 struct dm_info dmi; 432 char *params = NULL; 433 char *error = NULL; 434 char dev_uuid[DM_UUID_LEN] = {0}; 435 int r = -EINVAL; 436 uint32_t read_ahead = 0; 437 uint32_t cookie = 0; 438 uint16_t udev_flags = 0; 439 440 params = get_params(device, skip, offset, cipher, key_size, key); 441 if (!params) 442 goto out_no_removal; 443 444 if (type && !strncmp(type, "TEMP", 4)) 445 udev_flags = CRYPT_TEMP_UDEV_FLAGS; 446 447 /* All devices must have DM_UUID, only resize on old device is exception */ 448 if (reload) { 449 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD))) 450 goto out_no_removal; 451 452 if (!dm_task_set_name(dmt, name)) 453 goto out_no_removal; 454 } else { 455 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid)); 456 457 if (!(dmt = dm_task_create(DM_DEVICE_CREATE))) 458 goto out_no_removal; 459 460 if (!dm_task_set_name(dmt, name)) 461 goto out_no_removal; 462 463 if (!dm_task_set_uuid(dmt, dev_uuid)) 464 goto out_no_removal; 465 466 if (_dm_use_udev() && !dm_task_set_cookie(dmt, &cookie, udev_flags)) 467 goto out_no_removal; 468 } 469 470 if (read_only && !dm_task_set_ro(dmt)) 471 goto out_no_removal; 472 if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params)) 473 goto out_no_removal; 474 475 #ifdef DM_READ_AHEAD_MINIMUM_FLAG 476 if (_dev_read_ahead(device, &read_ahead) && 477 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG)) 478 goto out_no_removal; 479 #endif 480 481 if (!dm_task_run(dmt)) 482 goto out_no_removal; 483 484 if (reload) { 485 dm_task_destroy(dmt); 486 if (!(dmt = dm_task_create(DM_DEVICE_RESUME))) 487 goto out; 488 if (!dm_task_set_name(dmt, name)) 489 goto out; 490 if (uuid && !dm_task_set_uuid(dmt, dev_uuid)) 491 goto out; 492 if (_dm_use_udev() && !dm_task_set_cookie(dmt, &cookie, udev_flags)) 493 goto out; 494 if (!dm_task_run(dmt)) 495 goto out; 496 } 497 498 if (!dm_task_get_info(dmt, &dmi)) 499 goto out; 500 501 r = 0; 502 out: 503 if (_dm_use_udev()) { 504 (void)dm_udev_wait(cookie); 505 cookie = 0; 506 } 507 508 if (r < 0 && !reload) { 509 if (get_error()) 510 error = strdup(get_error()); 511 512 dm_remove_device(name, 0, 0); 513 514 if (error) { 515 set_error(error); 516 free(error); 517 } 518 } 519 520 out_no_removal: 521 if (cookie && _dm_use_udev()) 522 (void)dm_udev_wait(cookie); 523 524 if (params) 525 safe_free(params); 526 if (dmt) 527 dm_task_destroy(dmt); 528 529 dm_task_update_nodes(); 530 return r; 531 } 532 533 int dm_status_device(const char *name) 534 { 535 struct dm_task *dmt; 536 struct dm_info dmi; 537 uint64_t start, length; 538 char *target_type, *params; 539 void *next = NULL; 540 int r = -EINVAL; 541 542 if (!(dmt = dm_task_create(DM_DEVICE_STATUS))) 543 return -EINVAL; 544 545 if (!dm_task_set_name(dmt, name)) { 546 r = -EINVAL; 547 goto out; 548 } 549 550 if (!dm_task_run(dmt)) { 551 r = -EINVAL; 552 goto out; 553 } 554 555 if (!dm_task_get_info(dmt, &dmi)) { 556 r = -EINVAL; 557 goto out; 558 } 559 560 if (!dmi.exists) { 561 r = -ENODEV; 562 goto out; 563 } 564 565 next = dm_get_next_target(dmt, next, &start, &length, 566 &target_type, ¶ms); 567 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 || 568 start != 0 || next) 569 r = -EINVAL; 570 else 571 r = (dmi.open_count > 0); 572 out: 573 if (dmt) 574 dm_task_destroy(dmt); 575 576 return r; 577 } 578 579 int dm_query_device(const char *name, 580 char **device, 581 uint64_t *size, 582 uint64_t *skip, 583 uint64_t *offset, 584 char **cipher, 585 int *key_size, 586 char **key, 587 int *read_only, 588 int *suspended, 589 char **uuid) 590 { 591 struct dm_task *dmt; 592 struct dm_info dmi; 593 uint64_t start, length, val64; 594 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *tmp_uuid; 595 void *next = NULL; 596 int i, r = -EINVAL; 597 598 if (!(dmt = dm_task_create(DM_DEVICE_TABLE))) 599 goto out; 600 if (!dm_task_set_name(dmt, name)) 601 goto out; 602 r = -ENODEV; 603 if (!dm_task_run(dmt)) 604 goto out; 605 606 r = -EINVAL; 607 if (!dm_task_get_info(dmt, &dmi)) 608 goto out; 609 610 if (!dmi.exists) { 611 r = -ENODEV; 612 goto out; 613 } 614 615 next = dm_get_next_target(dmt, next, &start, &length, 616 &target_type, ¶ms); 617 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 || 618 start != 0 || next) 619 goto out; 620 621 if (size) 622 *size = length; 623 624 rcipher = strsep(¶ms, " "); 625 /* cipher */ 626 if (cipher) 627 *cipher = strdup(rcipher); 628 629 /* skip */ 630 key_ = strsep(¶ms, " "); 631 if (!params) 632 goto out; 633 val64 = strtoull(params, ¶ms, 10); 634 if (*params != ' ') 635 goto out; 636 params++; 637 if (skip) 638 *skip = val64; 639 640 /* device */ 641 rdevice = strsep(¶ms, " "); 642 if (device) 643 *device = lookup_dev(rdevice); 644 645 /*offset */ 646 if (!params) 647 goto out; 648 val64 = strtoull(params, ¶ms, 10); 649 if (*params) 650 goto out; 651 if (offset) 652 *offset = val64; 653 654 /* key_size */ 655 if (key_size) 656 *key_size = strlen(key_) / 2; 657 658 /* key */ 659 if (key_size && key) { 660 *key = safe_alloc(*key_size); 661 if (!*key) { 662 r = -ENOMEM; 663 goto out; 664 } 665 666 buffer[2] = '\0'; 667 for(i = 0; i < *key_size; i++) { 668 memcpy(buffer, &key_[i * 2], 2); 669 (*key)[i] = strtoul(buffer, &endp, 16); 670 if (endp != &buffer[2]) { 671 safe_free(key); 672 *key = NULL; 673 goto out; 674 } 675 } 676 } 677 memset(key_, 0, strlen(key_)); 678 679 if (read_only) 680 *read_only = dmi.read_only; 681 682 if (suspended) 683 *suspended = dmi.suspended; 684 685 if (uuid && (tmp_uuid = (char*)dm_task_get_uuid(dmt)) && 686 !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN)) 687 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN); 688 689 r = (dmi.open_count > 0); 690 out: 691 if (dmt) 692 dm_task_destroy(dmt); 693 694 return r; 695 } 696 697 static int _dm_message(const char *name, const char *msg) 698 { 699 int r = 0; 700 struct dm_task *dmt; 701 702 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG))) 703 return 0; 704 705 if (name && !dm_task_set_name(dmt, name)) 706 goto out; 707 708 if (!dm_task_set_sector(dmt, (uint64_t) 0)) 709 goto out; 710 711 if (!dm_task_set_message(dmt, msg)) 712 goto out; 713 714 r = dm_task_run(dmt); 715 716 out: 717 dm_task_destroy(dmt); 718 return r; 719 } 720 721 int dm_suspend_and_wipe_key(const char *name) 722 { 723 if (!_dm_check_versions()) 724 return -ENOTSUP; 725 726 if (!_dm_crypt_wipe_key_supported) 727 return -ENOTSUP; 728 729 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0)) 730 return -EINVAL; 731 732 if (!_dm_message(name, "key wipe")) { 733 _dm_simple(DM_DEVICE_RESUME, name, 1); 734 return -EINVAL; 735 } 736 737 return 0; 738 } 739 740 int dm_resume_and_reinstate_key(const char *name, 741 size_t key_size, 742 const char *key) 743 { 744 int msg_size = key_size * 2 + 10; // key set <key> 745 char *msg; 746 int r = 0; 747 748 if (!_dm_check_versions()) 749 return -ENOTSUP; 750 751 if (!_dm_crypt_wipe_key_supported) 752 return -ENOTSUP; 753 754 msg = safe_alloc(msg_size); 755 if (!msg) 756 return -ENOMEM; 757 758 memset(msg, 0, msg_size); 759 strcpy(msg, "key set "); 760 hex_key(&msg[8], key_size, key); 761 762 if (!_dm_message(name, msg) || 763 !_dm_simple(DM_DEVICE_RESUME, name, 1)) 764 r = -EINVAL; 765 766 safe_free(msg); 767 return r; 768 } 769 770 const char *dm_get_dir(void) 771 { 772 return dm_dir(); 773 } 774