lib/libdevmapper.c

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