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 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  29 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  30 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  31 #endif
  32
  33 /* Compatibility for old device-mapper without udev support */
  34 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  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 #define _dm_task_set_cookie     dm_task_set_cookie
  39 #define _dm_udev_wait           dm_udev_wait
  40 #else
  41 #define CRYPT_TEMP_UDEV_FLAGS   0
  42 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  43 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  44 #endif
  45
  46 static int _dm_use_udev()
  47 {
  48 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  49         return dm_udev_get_sync_support();
  50 #else
  51         return 0;
  52 #endif
  53 }
  54
  55 uint32_t dm_flags(void)
  56 {
  57         return _dm_crypt_flags;
  58 }
  59
  60 static void set_dm_error(int level, const char *file, int line,
  61                          const char *f, ...)
  62 {
  63         char *msg = NULL;
  64         va_list va;
  65
  66         va_start(va, f);
  67         if (vasprintf(&msg, f, va) > 0) {
  68                 if (level < 4) {
  69                         log_err(_context, msg);
  70                         log_err(_context, "\n");
  71                 } else
  72                         log_dbg(msg);
  73         }
  74         free(msg);
  75         va_end(va);
  76 }
  77
  78 static int _dm_simple(int task, const char *name, int udev_wait);
  79
  80 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
  81                                  unsigned crypt_min, unsigned crypt_patch)
  82 {
  83         unsigned dm_maj, dm_min, dm_patch;
  84
  85         if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
  86                 dm_maj = dm_min = dm_patch = 0;
  87
  88         log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
  89                 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
  90
  91         if (crypt_maj >= 1 && crypt_min >= 2)
  92                 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
  93         else
  94                 log_dbg("Suspend and resume disabled, no wipe key support.");
  95
  96         if (crypt_maj >= 1 && crypt_min >= 10)
  97                 _dm_crypt_flags |= DM_LMK_SUPPORTED;
  98
  99         if (dm_maj >= 4 && dm_min >= 20)
 100                 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
 101
 102         _dm_crypt_checked = 1;
 103 }
 104
 105 static int _dm_check_versions(void)
 106 {
 107         struct dm_task *dmt;
 108         struct dm_versions *target, *last_target;
 109         char dm_version[16];
 110
 111         if (_dm_crypt_checked)
 112                 return 1;
 113
 114         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 115                 return 0;
 116
 117         if (!dm_task_run(dmt)) {
 118                 dm_task_destroy(dmt);
 119                 return 0;
 120         }
 121
 122         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 123                 dm_task_destroy(dmt);
 124                 return 0;
 125         }
 126
 127         target = dm_task_get_versions(dmt);
 128         do {
 129                 last_target = target;
 130                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 131                         _dm_set_crypt_compat(dm_version,
 132                                              (unsigned)target->version[0],
 133                                              (unsigned)target->version[1],
 134                                              (unsigned)target->version[2]);
 135                 }
 136                 target = (void *) target + target->next;
 137         } while (last_target != target);
 138
 139         dm_task_destroy(dmt);
 140         return 1;
 141 }
 142
 143 int dm_init(struct crypt_device *context, int check_kernel)
 144 {
 145         if (!_dm_use_count++) {
 146                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 147                         check_kernel ? "" : " (NO kernel check requested)",
 148                         _dm_use_udev() ? "en" : "dis");
 149                 if (check_kernel && !_dm_check_versions()) {
 150                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 151                         return -1;
 152                 }
 153                 if (getuid() || geteuid())
 154                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 155                 dm_log_init(set_dm_error);
 156                 dm_log_init_verbose(10);
 157         }
 158
 159         // FIXME: global context is not safe
 160         if (context)
 161                 _context = context;
 162
 163         return 1;       /* unsafe memory */
 164 }
 165
 166 void dm_exit(void)
 167 {
 168         if (_dm_use_count && (!--_dm_use_count)) {
 169                 log_dbg("Releasing device-mapper backend.");
 170                 dm_log_init_verbose(0);
 171                 dm_log_init(NULL);
 172                 dm_lib_release();
 173                 _context = NULL;
 174         }
 175 }
 176
 177 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level)
 178 {
 179         struct dirent *entry;
 180         struct stat st;
 181         char *ptr;
 182         char *result = NULL;
 183         DIR *dir;
 184         int space;
 185
 186         /* Ignore strange nested directories */
 187         if (dir_level > max_level)
 188                 return NULL;
 189
 190         path[PATH_MAX - 1] = '\0';
 191         ptr = path + strlen(path);
 192         *ptr++ = '/';
 193         *ptr = '\0';
 194         space = PATH_MAX - (ptr - path);
 195
 196         dir = opendir(path);
 197         if (!dir)
 198                 return NULL;
 199
 200         while((entry = readdir(dir))) {
 201                 if (entry->d_name[0] == '.' ||
 202                     !strncmp(entry->d_name, "..", 2))
 203                         continue;
 204
 205                 strncpy(ptr, entry->d_name, space);
 206                 if (stat(path, &st) < 0)
 207                         continue;
 208
 209                 if (S_ISDIR(st.st_mode)) {
 210                         result = __lookup_dev(path, dev, dir_level + 1, max_level);
 211                         if (result)
 212                                 break;
 213                 } else if (S_ISBLK(st.st_mode)) {
 214                         /* workaround: ignore dm-X devices, these are internal kernel names */
 215                         if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3))
 216                                 continue;
 217                         if (st.st_rdev == dev) {
 218                                 result = strdup(path);
 219                                 break;
 220                         }
 221                 }
 222         }
 223
 224         closedir(dir);
 225         return result;
 226 }
 227
 228 static char *lookup_dev(const char *dev_id)
 229 {
 230         uint32_t major, minor;
 231         dev_t dev;
 232         char *result = NULL, buf[PATH_MAX + 1];
 233
 234         if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
 235                 return NULL;
 236
 237         dev = makedev(major, minor);
 238         strncpy(buf, DEVICE_DIR, PATH_MAX);
 239         buf[PATH_MAX] = '\0';
 240
 241         /* First try low level device */
 242         if ((result = __lookup_dev(buf, dev, 0, 0)))
 243                 return result;
 244
 245         /* If it is dm, try DM dir  */
 246         if (dm_is_dm_major(major)) {
 247                 strncpy(buf, dm_dir(), PATH_MAX);
 248                 if ((result = __lookup_dev(buf, dev, 0, 0)))
 249                         return result;
 250         }
 251
 252         strncpy(buf, DEVICE_DIR, PATH_MAX);
 253         result = __lookup_dev(buf, dev, 0, 4);
 254
 255         /* If not found, return NULL */
 256         return result;
 257 }
 258
 259 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead)
 260 {
 261         int fd, r = 0;
 262         long read_ahead_long;
 263
 264         if ((fd = open(dev, O_RDONLY)) < 0)
 265                 return 0;
 266
 267         r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1;
 268         close(fd);
 269
 270         if (r)
 271                 *read_ahead = (uint32_t) read_ahead_long;
 272
 273         return r;
 274 }
 275
 276 static void hex_key(char *hexkey, size_t key_size, const char *key)
 277 {
 278         int i;
 279
 280         for(i = 0; i < key_size; i++)
 281                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 282 }
 283
 284 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
 285                         const char *cipher, size_t key_size, const char *key)
 286 {
 287         char *params;
 288         char *hexkey;
 289
 290         hexkey = crypt_safe_alloc(key_size * 2 + 1);
 291         if (!hexkey)
 292                 return NULL;
 293
 294         hex_key(hexkey, key_size, key);
 295
 296         params = crypt_safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
 297         if (!params)
 298                 goto out;
 299
 300         sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
 301                 cipher, hexkey, skip, device, offset);
 302
 303 out:
 304         crypt_safe_free(hexkey);
 305         return params;
 306 }
 307
 308 /* DM helpers */
 309 static int _dm_simple(int task, const char *name, int udev_wait)
 310 {
 311         int r = 0;
 312         struct dm_task *dmt;
 313         uint32_t cookie = 0;
 314
 315         if (!_dm_use_udev())
 316                 udev_wait = 0;
 317
 318         if (!(dmt = dm_task_create(task)))
 319                 return 0;
 320
 321         if (name && !dm_task_set_name(dmt, name))
 322                 goto out;
 323
 324         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 325                 goto out;
 326
 327         r = dm_task_run(dmt);
 328
 329         if (udev_wait)
 330                 (void)_dm_udev_wait(cookie);
 331
 332       out:
 333         dm_task_destroy(dmt);
 334         return r;
 335 }
 336
 337 static int _error_device(const char *name, size_t size)
 338 {
 339         struct dm_task *dmt;
 340         int r = 0;
 341
 342         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 343                 return 0;
 344
 345         if (!dm_task_set_name(dmt, name))
 346                 goto error;
 347
 348         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 349                 goto error;
 350
 351         if (!dm_task_set_ro(dmt))
 352                 goto error;
 353
 354         if (!dm_task_no_open_count(dmt))
 355                 goto error;
 356
 357         if (!dm_task_run(dmt))
 358                 goto error;
 359
 360         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 361                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 362                 goto error;
 363         }
 364
 365         r = 1;
 366
 367 error:
 368         dm_task_destroy(dmt);
 369         return r;
 370 }
 371
 372 int dm_remove_device(const char *name, int force, uint64_t size)
 373 {
 374         int r = -EINVAL;
 375         int retries = force ? RETRY_COUNT : 1;
 376         int error_target = 0;
 377
 378         if (!name || (force && !size))
 379                 return -EINVAL;
 380
 381         do {
 382                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 383                 if (--retries && r) {
 384                         log_dbg("WARNING: other process locked internal device %s, %s.",
 385                                 name, retries ? "retrying remove" : "giving up");
 386                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 387                                 debug_processes_using_device(name);
 388                         sleep(1);
 389                         if (force && !error_target) {
 390                                 /* If force flag is set, replace device with error, read-only target.
 391                                  * it should stop processes from reading it and also removed underlying
 392                                  * device from mapping, so it is usable again.
 393                                  * Force flag should be used only for temporary devices, which are
 394                                  * intended to work inside cryptsetup only!
 395                                  * Anyway, if some process try to read temporary cryptsetup device,
 396                                  * it is bug - no other process should try touch it (e.g. udev).
 397                                  */
 398                                 _error_device(name, size);
 399                                 error_target = 1;
 400                         }
 401                 }
 402         } while (r == -EINVAL && retries);
 403
 404         dm_task_update_nodes();
 405
 406         return r;
 407 }
 408
 409 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 410 /*
 411  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 412  * CRYPT-PLAIN-name
 413  * CRYPT-LUKS1-00000000000000000000000000000000-name
 414  * CRYPT-TEMP-name
 415  */
 416 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 417 {
 418         char *ptr, uuid2[UUID_LEN] = {0};
 419         uuid_t uu;
 420         int i = 0;
 421
 422         /* Remove '-' chars */
 423         if (uuid && !uuid_parse(uuid, uu)) {
 424                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 425                         if (uuid[i] != '-') {
 426                                 *ptr = uuid[i];
 427                                 ptr++;
 428                         }
 429         }
 430
 431         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 432                 type ?: "", type ? "-" : "",
 433                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 434                 name);
 435
 436         log_dbg("DM-UUID is %s", buf);
 437         if (i >= buflen)
 438                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 439 }
 440
 441 int dm_create_device(const char *name,
 442                      const char *device,
 443                      const char *cipher,
 444                      const char *type,
 445                      const char *uuid,
 446                      uint64_t size,
 447                      uint64_t skip,
 448                      uint64_t offset,
 449                      size_t key_size,
 450                      const char *key,
 451                      int read_only,
 452                      int reload)
 453 {
 454         struct dm_task *dmt = NULL;
 455         struct dm_info dmi;
 456         char *params = NULL;
 457         char *error = NULL;
 458         char dev_uuid[DM_UUID_LEN] = {0};
 459         int r = -EINVAL;
 460         uint32_t read_ahead = 0;
 461         uint32_t cookie = 0;
 462         uint16_t udev_flags = 0;
 463
 464         params = get_params(device, skip, offset, cipher, key_size, key);
 465         if (!params)
 466                 goto out_no_removal;
 467
 468         if (type && !strncmp(type, "TEMP", 4))
 469                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 470
 471         /* All devices must have DM_UUID, only resize on old device is exception */
 472         if (reload) {
 473                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 474                         goto out_no_removal;
 475
 476                 if (!dm_task_set_name(dmt, name))
 477                         goto out_no_removal;
 478         } else {
 479                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 480
 481                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 482                         goto out_no_removal;
 483
 484                 if (!dm_task_set_name(dmt, name))
 485                         goto out_no_removal;
 486
 487                 if (!dm_task_set_uuid(dmt, dev_uuid))
 488                         goto out_no_removal;
 489
 490                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 491                         goto out_no_removal;
 492         }
 493
 494         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 495                 goto out_no_removal;
 496         if (read_only && !dm_task_set_ro(dmt))
 497                 goto out_no_removal;
 498         if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
 499                 goto out_no_removal;
 500
 501 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 502         if (_dev_read_ahead(device, &read_ahead) &&
 503             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 504                 goto out_no_removal;
 505 #endif
 506
 507         if (!dm_task_run(dmt))
 508                 goto out_no_removal;
 509
 510         if (reload) {
 511                 dm_task_destroy(dmt);
 512                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 513                         goto out;
 514                 if (!dm_task_set_name(dmt, name))
 515                         goto out;
 516                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 517                         goto out;
 518                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 519                         goto out;
 520                 if (!dm_task_run(dmt))
 521                         goto out;
 522         }
 523
 524         if (!dm_task_get_info(dmt, &dmi))
 525                 goto out;
 526
 527         r = 0;
 528 out:
 529         if (_dm_use_udev()) {
 530                 (void)_dm_udev_wait(cookie);
 531                 cookie = 0;
 532         }
 533
 534         if (r < 0 && !reload) {
 535                 if (get_error())
 536                         error = strdup(get_error());
 537
 538                 dm_remove_device(name, 0, 0);
 539
 540                 if (error) {
 541                         set_error(error);
 542                         free(error);
 543                 }
 544         }
 545
 546 out_no_removal:
 547         if (cookie && _dm_use_udev())
 548                 (void)_dm_udev_wait(cookie);
 549
 550         if (params)
 551                 crypt_safe_free(params);
 552         if (dmt)
 553                 dm_task_destroy(dmt);
 554
 555         dm_task_update_nodes();
 556         return r;
 557 }
 558
 559 int dm_status_device(const char *name)
 560 {
 561         struct dm_task *dmt;
 562         struct dm_info dmi;
 563         uint64_t start, length;
 564         char *target_type, *params;
 565         void *next = NULL;
 566         int r = -EINVAL;
 567
 568         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 569                 goto out;
 570
 571         if (!dm_task_set_name(dmt, name))
 572                 goto out;
 573
 574         if (!dm_task_run(dmt))
 575                 goto out;
 576
 577         if (!dm_task_get_info(dmt, &dmi))
 578                 goto out;
 579
 580         if (!dmi.exists) {
 581                 r = -ENODEV;
 582                 goto out;
 583         }
 584
 585         next = dm_get_next_target(dmt, next, &start, &length,
 586                                   &target_type, &params);
 587         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 588             start != 0 || next)
 589                 r = -EINVAL;
 590         else
 591                 r = (dmi.open_count > 0);
 592 out:
 593         if (dmt)
 594                 dm_task_destroy(dmt);
 595
 596         return r;
 597 }
 598
 599 int dm_query_device(const char *name,
 600                     char **device,
 601                     uint64_t *size,
 602                     uint64_t *skip,
 603                     uint64_t *offset,
 604                     char **cipher,
 605                     int *key_size,
 606                     char **key,
 607                     int *read_only,
 608                     int *suspended,
 609                     char **uuid)
 610 {
 611         struct dm_task *dmt;
 612         struct dm_info dmi;
 613         uint64_t start, length, val64;
 614         char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *tmp_uuid;
 615         void *next = NULL;
 616         int i, r = -EINVAL;
 617
 618         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 619                 goto out;
 620         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 621                 goto out;
 622         if (!dm_task_set_name(dmt, name))
 623                 goto out;
 624         r = -ENODEV;
 625         if (!dm_task_run(dmt))
 626                 goto out;
 627
 628         r = -EINVAL;
 629         if (!dm_task_get_info(dmt, &dmi))
 630                 goto out;
 631
 632         if (!dmi.exists) {
 633                 r = -ENODEV;
 634                 goto out;
 635         }
 636
 637         next = dm_get_next_target(dmt, next, &start, &length,
 638                                   &target_type, &params);
 639         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 640             start != 0 || next)
 641                 goto out;
 642
 643         if (size)
 644                 *size = length;
 645
 646         rcipher = strsep(&params, " ");
 647         /* cipher */
 648         if (cipher)
 649                 *cipher = strdup(rcipher);
 650
 651         /* skip */
 652         key_ = strsep(&params, " ");
 653         if (!params)
 654                 goto out;
 655         val64 = strtoull(params, &params, 10);
 656         if (*params != ' ')
 657                 goto out;
 658         params++;
 659         if (skip)
 660                 *skip = val64;
 661
 662         /* device */
 663         rdevice = strsep(&params, " ");
 664         if (device)
 665                 *device = lookup_dev(rdevice);
 666
 667         /*offset */
 668         if (!params)
 669                 goto out;
 670         val64 = strtoull(params, &params, 10);
 671         if (*params)
 672                 goto out;
 673         if (offset)
 674                 *offset = val64;
 675
 676         /* key_size */
 677         if (key_size)
 678                 *key_size = strlen(key_) / 2;
 679
 680         /* key */
 681         if (key_size && key) {
 682                 *key = crypt_safe_alloc(*key_size);
 683                 if (!*key) {
 684                         r = -ENOMEM;
 685                         goto out;
 686                 }
 687
 688                 buffer[2] = '\0';
 689                 for(i = 0; i < *key_size; i++) {
 690                         memcpy(buffer, &key_[i * 2], 2);
 691                         (*key)[i] = strtoul(buffer, &endp, 16);
 692                         if (endp != &buffer[2]) {
 693                                 crypt_safe_free(key);
 694                                 *key = NULL;
 695                                 goto out;
 696                         }
 697                 }
 698         }
 699         memset(key_, 0, strlen(key_));
 700
 701         if (read_only)
 702                 *read_only = dmi.read_only;
 703
 704         if (suspended)
 705                 *suspended = dmi.suspended;
 706
 707         if (uuid && (tmp_uuid = (char*)dm_task_get_uuid(dmt)) &&
 708             !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 709                 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 710
 711         r = (dmi.open_count > 0);
 712 out:
 713         if (dmt)
 714                 dm_task_destroy(dmt);
 715
 716         return r;
 717 }
 718
 719 static int _dm_message(const char *name, const char *msg)
 720 {
 721         int r = 0;
 722         struct dm_task *dmt;
 723
 724         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 725                 return 0;
 726
 727         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 728                 goto out;
 729
 730         if (name && !dm_task_set_name(dmt, name))
 731                 goto out;
 732
 733         if (!dm_task_set_sector(dmt, (uint64_t) 0))
 734                 goto out;
 735
 736         if (!dm_task_set_message(dmt, msg))
 737                 goto out;
 738
 739         r = dm_task_run(dmt);
 740
 741       out:
 742         dm_task_destroy(dmt);
 743         return r;
 744 }
 745
 746 int dm_suspend_and_wipe_key(const char *name)
 747 {
 748         if (!_dm_check_versions())
 749                 return -ENOTSUP;
 750
 751         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 752                 return -ENOTSUP;
 753
 754         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
 755                 return -EINVAL;
 756
 757         if (!_dm_message(name, "key wipe")) {
 758                 _dm_simple(DM_DEVICE_RESUME, name, 1);
 759                 return -EINVAL;
 760         }
 761
 762         return 0;
 763 }
 764
 765 int dm_resume_and_reinstate_key(const char *name,
 766                                 size_t key_size,
 767                                 const char *key)
 768 {
 769         int msg_size = key_size * 2 + 10; // key set <key>
 770         char *msg;
 771         int r = 0;
 772
 773         if (!_dm_check_versions())
 774                 return -ENOTSUP;
 775
 776         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 777                 return -ENOTSUP;
 778
 779         msg = crypt_safe_alloc(msg_size);
 780         if (!msg)
 781                 return -ENOMEM;
 782
 783         memset(msg, 0, msg_size);
 784         strcpy(msg, "key set ");
 785         hex_key(&msg[8], key_size, key);
 786
 787         if (!_dm_message(name, msg) ||
 788             !_dm_simple(DM_DEVICE_RESUME, name, 1))
 789                 r = -EINVAL;
 790
 791         crypt_safe_free(msg);
 792         return r;
 793 }
 794
 795 const char *dm_get_dir(void)
 796 {
 797         return dm_dir();
 798 }