lib/libdevmapper.c

   1 /*
   2  * libdevmapper - device-mapper backend for cryptsetup
   3  *
   4  * Copyright (C) 2004, Christophe Saout <christophe@saout.de>
   5  * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
   6  * Copyright (C) 2009-2011, Red Hat, Inc. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program 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
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <sys/ioctl.h>
  23 #include <sys/stat.h>
  24 #include <stdio.h>
  25 #include <dirent.h>
  26 #include <errno.h>
  27 #include <libdevmapper.h>
  28 #include <fcntl.h>
  29 #include <linux/fs.h>
  30 #include <uuid/uuid.h>
  31
  32 #include "internal.h"
  33 #include "luks.h"
  34
  35 #define DEVICE_DIR              "/dev"
  36 #define DM_UUID_LEN             129
  37 #define DM_UUID_PREFIX          "CRYPT-"
  38 #define DM_UUID_PREFIX_LEN      6
  39 #define DM_CRYPT_TARGET         "crypt"
  40 #define RETRY_COUNT             5
  41
  42 /* Set if dm-crypt version was probed */
  43 static int _dm_crypt_checked = 0;
  44 static uint32_t _dm_crypt_flags = 0;
  45
  46 static int _dm_use_count = 0;
  47 static struct crypt_device *_context = NULL;
  48
  49 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  50 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  51 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  52 #endif
  53
  54 /* Compatibility for old device-mapper without udev support */
  55 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  56 #define CRYPT_TEMP_UDEV_FLAGS   DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
  57                                 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
  58                                 DM_UDEV_DISABLE_OTHER_RULES_FLAG
  59 #define _dm_task_set_cookie     dm_task_set_cookie
  60 #define _dm_udev_wait           dm_udev_wait
  61 #else
  62 #define CRYPT_TEMP_UDEV_FLAGS   0
  63 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  64 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  65 #endif
  66
  67 static int _dm_use_udev()
  68 {
  69 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  70         return dm_udev_get_sync_support();
  71 #else
  72         return 0;
  73 #endif
  74 }
  75
  76 static void set_dm_error(int level, const char *file, int line,
  77                          const char *f, ...)
  78 {
  79         char *msg = NULL;
  80         va_list va;
  81
  82         va_start(va, f);
  83         if (vasprintf(&msg, f, va) > 0) {
  84                 if (level < 4) {
  85                         log_err(_context, msg);
  86                         log_err(_context, "\n");
  87                 } else
  88                         log_dbg(msg);
  89         }
  90         free(msg);
  91         va_end(va);
  92 }
  93
  94 static int _dm_simple(int task, const char *name, int udev_wait);
  95
  96 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
  97                                  unsigned crypt_min, unsigned crypt_patch)
  98 {
  99         unsigned dm_maj, dm_min, dm_patch;
 100
 101         if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
 102                 dm_maj = dm_min = dm_patch = 0;
 103
 104         log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
 105                 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
 106
 107         if (crypt_maj >= 1 && crypt_min >= 2)
 108                 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
 109         else
 110                 log_dbg("Suspend and resume disabled, no wipe key support.");
 111
 112         if (crypt_maj >= 1 && crypt_min >= 10)
 113                 _dm_crypt_flags |= DM_LMK_SUPPORTED;
 114
 115         if (dm_maj >= 4 && dm_min >= 20)
 116                 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
 117
 118         /* not perfect, 2.6.33 supports with 1.7.0 */
 119         if (crypt_maj >= 1 && crypt_min >= 8)
 120                 _dm_crypt_flags |= DM_PLAIN64_SUPPORTED;
 121
 122         /* Repeat test if dm-crypt is not present */
 123         if (crypt_maj > 0)
 124                 _dm_crypt_checked = 1;
 125 }
 126
 127 static int _dm_check_versions(void)
 128 {
 129         struct dm_task *dmt;
 130         struct dm_versions *target, *last_target;
 131         char dm_version[16];
 132
 133         if (_dm_crypt_checked)
 134                 return 1;
 135
 136         /* FIXME: add support to DM so it forces crypt target module load here */
 137         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 138                 return 0;
 139
 140         if (!dm_task_run(dmt)) {
 141                 dm_task_destroy(dmt);
 142                 return 0;
 143         }
 144
 145         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 146                 dm_task_destroy(dmt);
 147                 return 0;
 148         }
 149
 150         target = dm_task_get_versions(dmt);
 151         do {
 152                 last_target = target;
 153                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 154                         _dm_set_crypt_compat(dm_version,
 155                                              (unsigned)target->version[0],
 156                                              (unsigned)target->version[1],
 157                                              (unsigned)target->version[2]);
 158                 }
 159                 target = (void *) target + target->next;
 160         } while (last_target != target);
 161
 162         dm_task_destroy(dmt);
 163         return 1;
 164 }
 165
 166 uint32_t dm_flags(void)
 167 {
 168         if (!_dm_crypt_checked)
 169                 _dm_check_versions();
 170
 171         return _dm_crypt_flags;
 172 }
 173
 174 int dm_init(struct crypt_device *context, int check_kernel)
 175 {
 176         if (!_dm_use_count++) {
 177                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 178                         check_kernel ? "" : " (NO kernel check requested)",
 179                         _dm_use_udev() ? "en" : "dis");
 180                 if (check_kernel && !_dm_check_versions()) {
 181                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 182                         return -1;
 183                 }
 184                 if (getuid() || geteuid())
 185                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 186                 dm_log_init(set_dm_error);
 187                 dm_log_init_verbose(10);
 188         }
 189
 190         // FIXME: global context is not safe
 191         if (context)
 192                 _context = context;
 193
 194         return 1;       /* unsafe memory */
 195 }
 196
 197 void dm_exit(void)
 198 {
 199         if (_dm_use_count && (!--_dm_use_count)) {
 200                 log_dbg("Releasing device-mapper backend.");
 201                 dm_log_init_verbose(0);
 202                 dm_log_init(NULL);
 203                 dm_lib_release();
 204                 _context = NULL;
 205         }
 206 }
 207
 208 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level)
 209 {
 210         struct dirent *entry;
 211         struct stat st;
 212         char *ptr;
 213         char *result = NULL;
 214         DIR *dir;
 215         int space;
 216
 217         /* Ignore strange nested directories */
 218         if (dir_level > max_level)
 219                 return NULL;
 220
 221         path[PATH_MAX - 1] = '\0';
 222         ptr = path + strlen(path);
 223         *ptr++ = '/';
 224         *ptr = '\0';
 225         space = PATH_MAX - (ptr - path);
 226
 227         dir = opendir(path);
 228         if (!dir)
 229                 return NULL;
 230
 231         while((entry = readdir(dir))) {
 232                 if (entry->d_name[0] == '.' ||
 233                     !strncmp(entry->d_name, "..", 2))
 234                         continue;
 235
 236                 strncpy(ptr, entry->d_name, space);
 237                 if (stat(path, &st) < 0)
 238                         continue;
 239
 240                 if (S_ISDIR(st.st_mode)) {
 241                         result = __lookup_dev(path, dev, dir_level + 1, max_level);
 242                         if (result)
 243                                 break;
 244                 } else if (S_ISBLK(st.st_mode)) {
 245                         /* workaround: ignore dm-X devices, these are internal kernel names */
 246                         if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3))
 247                                 continue;
 248                         if (st.st_rdev == dev) {
 249                                 result = strdup(path);
 250                                 break;
 251                         }
 252                 }
 253         }
 254
 255         closedir(dir);
 256         return result;
 257 }
 258
 259 static char *lookup_dev(const char *dev_id)
 260 {
 261         uint32_t major, minor;
 262         dev_t dev;
 263         char *result = NULL, buf[PATH_MAX + 1];
 264
 265         if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
 266                 return NULL;
 267
 268         dev = makedev(major, minor);
 269         strncpy(buf, DEVICE_DIR, PATH_MAX);
 270         buf[PATH_MAX] = '\0';
 271
 272         /* First try low level device */
 273         if ((result = __lookup_dev(buf, dev, 0, 0)))
 274                 return result;
 275
 276         /* If it is dm, try DM dir  */
 277         if (dm_is_dm_major(major)) {
 278                 strncpy(buf, dm_dir(), PATH_MAX);
 279                 if ((result = __lookup_dev(buf, dev, 0, 0)))
 280                         return result;
 281         }
 282
 283         strncpy(buf, DEVICE_DIR, PATH_MAX);
 284         result = __lookup_dev(buf, dev, 0, 4);
 285
 286         /* If not found, return NULL */
 287         return result;
 288 }
 289
 290 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead)
 291 {
 292         int fd, r = 0;
 293         long read_ahead_long;
 294
 295         if ((fd = open(dev, O_RDONLY)) < 0)
 296                 return 0;
 297
 298         r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1;
 299         close(fd);
 300
 301         if (r)
 302                 *read_ahead = (uint32_t) read_ahead_long;
 303
 304         return r;
 305 }
 306
 307 static void hex_key(char *hexkey, size_t key_size, const char *key)
 308 {
 309         int i;
 310
 311         for(i = 0; i < key_size; i++)
 312                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 313 }
 314
 315 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
 316                         const char *cipher, size_t key_size, const char *key)
 317 {
 318         char *params;
 319         char *hexkey;
 320
 321         hexkey = crypt_safe_alloc(key_size * 2 + 1);
 322         if (!hexkey)
 323                 return NULL;
 324
 325         hex_key(hexkey, key_size, key);
 326
 327         params = crypt_safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
 328         if (!params)
 329                 goto out;
 330
 331         sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
 332                 cipher, hexkey, skip, device, offset);
 333
 334 out:
 335         crypt_safe_free(hexkey);
 336         return params;
 337 }
 338
 339 /* DM helpers */
 340 static int _dm_simple(int task, const char *name, int udev_wait)
 341 {
 342         int r = 0;
 343         struct dm_task *dmt;
 344         uint32_t cookie = 0;
 345
 346         if (!_dm_use_udev())
 347                 udev_wait = 0;
 348
 349         if (!(dmt = dm_task_create(task)))
 350                 return 0;
 351
 352         if (name && !dm_task_set_name(dmt, name))
 353                 goto out;
 354
 355         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 356                 goto out;
 357
 358         r = dm_task_run(dmt);
 359
 360         if (udev_wait)
 361                 (void)_dm_udev_wait(cookie);
 362
 363       out:
 364         dm_task_destroy(dmt);
 365         return r;
 366 }
 367
 368 static int _error_device(const char *name, size_t size)
 369 {
 370         struct dm_task *dmt;
 371         int r = 0;
 372
 373         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 374                 return 0;
 375
 376         if (!dm_task_set_name(dmt, name))
 377                 goto error;
 378
 379         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 380                 goto error;
 381
 382         if (!dm_task_set_ro(dmt))
 383                 goto error;
 384
 385         if (!dm_task_no_open_count(dmt))
 386                 goto error;
 387
 388         if (!dm_task_run(dmt))
 389                 goto error;
 390
 391         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 392                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 393                 goto error;
 394         }
 395
 396         r = 1;
 397
 398 error:
 399         dm_task_destroy(dmt);
 400         return r;
 401 }
 402
 403 int dm_remove_device(const char *name, int force, uint64_t size)
 404 {
 405         int r = -EINVAL;
 406         int retries = force ? RETRY_COUNT : 1;
 407         int error_target = 0;
 408
 409         if (!name || (force && !size))
 410                 return -EINVAL;
 411
 412         do {
 413                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 414                 if (--retries && r) {
 415                         log_dbg("WARNING: other process locked internal device %s, %s.",
 416                                 name, retries ? "retrying remove" : "giving up");
 417                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 418                                 debug_processes_using_device(name);
 419                         sleep(1);
 420                         if (force && !error_target) {
 421                                 /* If force flag is set, replace device with error, read-only target.
 422                                  * it should stop processes from reading it and also removed underlying
 423                                  * device from mapping, so it is usable again.
 424                                  * Force flag should be used only for temporary devices, which are
 425                                  * intended to work inside cryptsetup only!
 426                                  * Anyway, if some process try to read temporary cryptsetup device,
 427                                  * it is bug - no other process should try touch it (e.g. udev).
 428                                  */
 429                                 _error_device(name, size);
 430                                 error_target = 1;
 431                         }
 432                 }
 433         } while (r == -EINVAL && retries);
 434
 435         dm_task_update_nodes();
 436
 437         return r;
 438 }
 439
 440 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 441 /*
 442  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 443  * CRYPT-PLAIN-name
 444  * CRYPT-LUKS1-00000000000000000000000000000000-name
 445  * CRYPT-TEMP-name
 446  */
 447 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 448 {
 449         char *ptr, uuid2[UUID_LEN] = {0};
 450         uuid_t uu;
 451         int i = 0;
 452
 453         /* Remove '-' chars */
 454         if (uuid && !uuid_parse(uuid, uu)) {
 455                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 456                         if (uuid[i] != '-') {
 457                                 *ptr = uuid[i];
 458                                 ptr++;
 459                         }
 460         }
 461
 462         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 463                 type ?: "", type ? "-" : "",
 464                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 465                 name);
 466
 467         log_dbg("DM-UUID is %s", buf);
 468         if (i >= buflen)
 469                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 470 }
 471
 472 int dm_create_device(const char *name,
 473                      const char *device,
 474                      const char *cipher,
 475                      const char *type,
 476                      const char *uuid,
 477                      uint64_t size,
 478                      uint64_t skip,
 479                      uint64_t offset,
 480                      size_t key_size,
 481                      const char *key,
 482                      int read_only,
 483                      int reload)
 484 {
 485         struct dm_task *dmt = NULL;
 486         struct dm_info dmi;
 487         char *params = NULL;
 488         char *error = NULL;
 489         char dev_uuid[DM_UUID_LEN] = {0};
 490         int r = -EINVAL;
 491         uint32_t read_ahead = 0;
 492         uint32_t cookie = 0;
 493         uint16_t udev_flags = 0;
 494
 495         params = get_params(device, skip, offset, cipher, key_size, key);
 496         if (!params)
 497                 goto out_no_removal;
 498
 499         if (type && !strncmp(type, "TEMP", 4))
 500                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 501
 502         /* All devices must have DM_UUID, only resize on old device is exception */
 503         if (reload) {
 504                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 505                         goto out_no_removal;
 506
 507                 if (!dm_task_set_name(dmt, name))
 508                         goto out_no_removal;
 509         } else {
 510                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 511
 512                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 513                         goto out_no_removal;
 514
 515                 if (!dm_task_set_name(dmt, name))
 516                         goto out_no_removal;
 517
 518                 if (!dm_task_set_uuid(dmt, dev_uuid))
 519                         goto out_no_removal;
 520
 521                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 522                         goto out_no_removal;
 523         }
 524
 525         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 526                 goto out_no_removal;
 527         if (read_only && !dm_task_set_ro(dmt))
 528                 goto out_no_removal;
 529         if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
 530                 goto out_no_removal;
 531
 532 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 533         if (_dev_read_ahead(device, &read_ahead) &&
 534             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 535                 goto out_no_removal;
 536 #endif
 537
 538         if (!dm_task_run(dmt))
 539                 goto out_no_removal;
 540
 541         if (reload) {
 542                 dm_task_destroy(dmt);
 543                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 544                         goto out;
 545                 if (!dm_task_set_name(dmt, name))
 546                         goto out;
 547                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 548                         goto out;
 549                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 550                         goto out;
 551                 if (!dm_task_run(dmt))
 552                         goto out;
 553         }
 554
 555         if (!dm_task_get_info(dmt, &dmi))
 556                 goto out;
 557
 558         r = 0;
 559 out:
 560         if (_dm_use_udev()) {
 561                 (void)_dm_udev_wait(cookie);
 562                 cookie = 0;
 563         }
 564
 565         if (r < 0 && !reload) {
 566                 if (get_error())
 567                         error = strdup(get_error());
 568
 569                 dm_remove_device(name, 0, 0);
 570
 571                 if (error) {
 572                         set_error(error);
 573                         free(error);
 574                 }
 575         }
 576
 577 out_no_removal:
 578         if (cookie && _dm_use_udev())
 579                 (void)_dm_udev_wait(cookie);
 580
 581         if (params)
 582                 crypt_safe_free(params);
 583         if (dmt)
 584                 dm_task_destroy(dmt);
 585
 586         dm_task_update_nodes();
 587         return r;
 588 }
 589
 590 int dm_status_device(const char *name)
 591 {
 592         struct dm_task *dmt;
 593         struct dm_info dmi;
 594         uint64_t start, length;
 595         char *target_type, *params;
 596         void *next = NULL;
 597         int r = -EINVAL;
 598
 599         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 600                 goto out;
 601
 602         if (!dm_task_set_name(dmt, name))
 603                 goto out;
 604
 605         if (!dm_task_run(dmt))
 606                 goto out;
 607
 608         if (!dm_task_get_info(dmt, &dmi))
 609                 goto out;
 610
 611         if (!dmi.exists) {
 612                 r = -ENODEV;
 613                 goto out;
 614         }
 615
 616         next = dm_get_next_target(dmt, next, &start, &length,
 617                                   &target_type, &params);
 618         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 619             start != 0 || next)
 620                 r = -EINVAL;
 621         else
 622                 r = (dmi.open_count > 0);
 623 out:
 624         if (dmt)
 625                 dm_task_destroy(dmt);
 626
 627         return r;
 628 }
 629
 630 int dm_query_device(const char *name,
 631                     char **device,
 632                     uint64_t *size,
 633                     uint64_t *skip,
 634                     uint64_t *offset,
 635                     char **cipher,
 636                     int *key_size,
 637                     char **key,
 638                     int *read_only,
 639                     int *suspended,
 640                     char **uuid)
 641 {
 642         struct dm_task *dmt;
 643         struct dm_info dmi;
 644         uint64_t start, length, val64;
 645         char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *tmp_uuid;
 646         void *next = NULL;
 647         int i, r = -EINVAL;
 648
 649         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 650                 goto out;
 651         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 652                 goto out;
 653         if (!dm_task_set_name(dmt, name))
 654                 goto out;
 655         r = -ENODEV;
 656         if (!dm_task_run(dmt))
 657                 goto out;
 658
 659         r = -EINVAL;
 660         if (!dm_task_get_info(dmt, &dmi))
 661                 goto out;
 662
 663         if (!dmi.exists) {
 664                 r = -ENODEV;
 665                 goto out;
 666         }
 667
 668         next = dm_get_next_target(dmt, next, &start, &length,
 669                                   &target_type, &params);
 670         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 671             start != 0 || next)
 672                 goto out;
 673
 674         if (size)
 675                 *size = length;
 676
 677         rcipher = strsep(&params, " ");
 678         /* cipher */
 679         if (cipher)
 680                 *cipher = strdup(rcipher);
 681
 682         /* skip */
 683         key_ = strsep(&params, " ");
 684         if (!params)
 685                 goto out;
 686         val64 = strtoull(params, &params, 10);
 687         if (*params != ' ')
 688                 goto out;
 689         params++;
 690         if (skip)
 691                 *skip = val64;
 692
 693         /* device */
 694         rdevice = strsep(&params, " ");
 695         if (device)
 696                 *device = lookup_dev(rdevice);
 697
 698         /*offset */
 699         if (!params)
 700                 goto out;
 701         val64 = strtoull(params, &params, 10);
 702         if (*params)
 703                 goto out;
 704         if (offset)
 705                 *offset = val64;
 706
 707         /* key_size */
 708         if (key_size)
 709                 *key_size = strlen(key_) / 2;
 710
 711         /* key */
 712         if (key_size && key) {
 713                 *key = crypt_safe_alloc(*key_size);
 714                 if (!*key) {
 715                         r = -ENOMEM;
 716                         goto out;
 717                 }
 718
 719                 buffer[2] = '\0';
 720                 for(i = 0; i < *key_size; i++) {
 721                         memcpy(buffer, &key_[i * 2], 2);
 722                         (*key)[i] = strtoul(buffer, &endp, 16);
 723                         if (endp != &buffer[2]) {
 724                                 crypt_safe_free(key);
 725                                 *key = NULL;
 726                                 goto out;
 727                         }
 728                 }
 729         }
 730         memset(key_, 0, strlen(key_));
 731
 732         if (read_only)
 733                 *read_only = dmi.read_only;
 734
 735         if (suspended)
 736                 *suspended = dmi.suspended;
 737
 738         if (uuid && (tmp_uuid = (char*)dm_task_get_uuid(dmt)) &&
 739             !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 740                 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 741
 742         r = (dmi.open_count > 0);
 743 out:
 744         if (dmt)
 745                 dm_task_destroy(dmt);
 746
 747         return r;
 748 }
 749
 750 static int _dm_message(const char *name, const char *msg)
 751 {
 752         int r = 0;
 753         struct dm_task *dmt;
 754
 755         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 756                 return 0;
 757
 758         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 759                 goto out;
 760
 761         if (name && !dm_task_set_name(dmt, name))
 762                 goto out;
 763
 764         if (!dm_task_set_sector(dmt, (uint64_t) 0))
 765                 goto out;
 766
 767         if (!dm_task_set_message(dmt, msg))
 768                 goto out;
 769
 770         r = dm_task_run(dmt);
 771
 772       out:
 773         dm_task_destroy(dmt);
 774         return r;
 775 }
 776
 777 int dm_suspend_and_wipe_key(const char *name)
 778 {
 779         if (!_dm_check_versions())
 780                 return -ENOTSUP;
 781
 782         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 783                 return -ENOTSUP;
 784
 785         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
 786                 return -EINVAL;
 787
 788         if (!_dm_message(name, "key wipe")) {
 789                 _dm_simple(DM_DEVICE_RESUME, name, 1);
 790                 return -EINVAL;
 791         }
 792
 793         return 0;
 794 }
 795
 796 int dm_resume_and_reinstate_key(const char *name,
 797                                 size_t key_size,
 798                                 const char *key)
 799 {
 800         int msg_size = key_size * 2 + 10; // key set <key>
 801         char *msg;
 802         int r = 0;
 803
 804         if (!_dm_check_versions())
 805                 return -ENOTSUP;
 806
 807         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 808                 return -ENOTSUP;
 809
 810         msg = crypt_safe_alloc(msg_size);
 811         if (!msg)
 812                 return -ENOMEM;
 813
 814         memset(msg, 0, msg_size);
 815         strcpy(msg, "key set ");
 816         hex_key(&msg[8], key_size, key);
 817
 818         if (!_dm_message(name, msg) ||
 819             !_dm_simple(DM_DEVICE_RESUME, name, 1))
 820                 r = -EINVAL;
 821
 822         crypt_safe_free(msg);
 823         return r;
 824 }
 825
 826 const char *dm_get_dir(void)
 827 {
 828         return dm_dir();
 829 }