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) 2009-2012, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25 #include <libdevmapper.h>
  26 #include <fcntl.h>
  27 #include <linux/fs.h>
  28 #include <uuid/uuid.h>
  29
  30 #include "internal.h"
  31 #include "luks.h"
  32
  33 #define DM_UUID_LEN             129
  34 #define DM_UUID_PREFIX          "CRYPT-"
  35 #define DM_UUID_PREFIX_LEN      6
  36 #define DM_CRYPT_TARGET         "crypt"
  37 #define RETRY_COUNT             5
  38
  39 /* Set if dm-crypt version was probed */
  40 static int _dm_crypt_checked = 0;
  41 static uint32_t _dm_crypt_flags = 0;
  42
  43 static int _dm_use_count = 0;
  44 static struct crypt_device *_context = NULL;
  45
  46 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  47 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  48 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  49 #endif
  50
  51 /* Compatibility for old device-mapper without udev support */
  52 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  53 #define CRYPT_TEMP_UDEV_FLAGS   DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
  54                                 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
  55                                 DM_UDEV_DISABLE_OTHER_RULES_FLAG
  56 #define _dm_task_set_cookie     dm_task_set_cookie
  57 #define _dm_udev_wait           dm_udev_wait
  58 #else
  59 #define CRYPT_TEMP_UDEV_FLAGS   0
  60 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  61 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  62 #endif
  63
  64 static int _dm_use_udev(void)
  65 {
  66 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  67         return dm_udev_get_sync_support();
  68 #else
  69         return 0;
  70 #endif
  71 }
  72
  73 __attribute__((format(printf, 4, 5)))
  74 static void set_dm_error(int level,
  75                          const char *file __attribute__((unused)),
  76                          int line __attribute__((unused)),
  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         if (crypt_maj >= 1 && crypt_min >= 11)
 123                 _dm_crypt_flags |= DM_DISCARDS_SUPPORTED;
 124
 125         /* Repeat test if dm-crypt is not present */
 126         if (crypt_maj > 0)
 127                 _dm_crypt_checked = 1;
 128 }
 129
 130 static int _dm_check_versions(void)
 131 {
 132         struct dm_task *dmt;
 133         struct dm_versions *target, *last_target;
 134         char dm_version[16];
 135
 136         if (_dm_crypt_checked)
 137                 return 1;
 138
 139         /* FIXME: add support to DM so it forces crypt target module load here */
 140         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 141                 return 0;
 142
 143         if (!dm_task_run(dmt)) {
 144                 dm_task_destroy(dmt);
 145                 return 0;
 146         }
 147
 148         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 149                 dm_task_destroy(dmt);
 150                 return 0;
 151         }
 152
 153         target = dm_task_get_versions(dmt);
 154         do {
 155                 last_target = target;
 156                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 157                         _dm_set_crypt_compat(dm_version,
 158                                              (unsigned)target->version[0],
 159                                              (unsigned)target->version[1],
 160                                              (unsigned)target->version[2]);
 161                 }
 162                 target = (struct dm_versions *)((char *) target + target->next);
 163         } while (last_target != target);
 164
 165         dm_task_destroy(dmt);
 166         return 1;
 167 }
 168
 169 uint32_t dm_flags(void)
 170 {
 171         if (!_dm_crypt_checked)
 172                 _dm_check_versions();
 173
 174         return _dm_crypt_flags;
 175 }
 176
 177 int dm_init(struct crypt_device *context, int check_kernel)
 178 {
 179         if (!_dm_use_count++) {
 180                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 181                         check_kernel ? "" : " (NO kernel check requested)",
 182                         _dm_use_udev() ? "en" : "dis");
 183                 if (check_kernel && !_dm_check_versions()) {
 184                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 185                         return -1;
 186                 }
 187                 if (getuid() || geteuid())
 188                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 189                 dm_log_init(set_dm_error);
 190                 dm_log_init_verbose(10);
 191         }
 192
 193         // FIXME: global context is not safe
 194         if (context)
 195                 _context = context;
 196
 197         return 1;       /* unsafe memory */
 198 }
 199
 200 void dm_exit(void)
 201 {
 202         if (_dm_use_count && (!--_dm_use_count)) {
 203                 log_dbg("Releasing device-mapper backend.");
 204                 dm_log_init_verbose(0);
 205                 dm_log_init(NULL);
 206                 dm_lib_release();
 207                 _context = NULL;
 208         }
 209 }
 210
 211 /* Return path to DM device */
 212 char *dm_device_path(const char *prefix, int major, int minor)
 213 {
 214         struct dm_task *dmt;
 215         const char *name;
 216         char path[PATH_MAX];
 217
 218         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 219                 return NULL;
 220         if (!dm_task_set_minor(dmt, minor) ||
 221             !dm_task_set_major(dmt, major) ||
 222             !dm_task_run(dmt) ||
 223             !(name = dm_task_get_name(dmt))) {
 224                 dm_task_destroy(dmt);
 225                 return NULL;
 226         }
 227
 228         if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
 229                 path[0] = '\0';
 230
 231         dm_task_destroy(dmt);
 232
 233         return strdup(path);
 234 }
 235
 236 static void hex_key(char *hexkey, size_t key_size, const char *key)
 237 {
 238         unsigned i;
 239
 240         for(i = 0; i < key_size; i++)
 241                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 242 }
 243
 244 static char *get_params(struct crypt_dm_active_device *dmd)
 245 {
 246         int r, max_size;
 247         char *params, *hexkey;
 248         const char *features = "";
 249
 250         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 251                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 252                         features = " 1 allow_discards";
 253                         log_dbg("Discard/TRIM is allowed.");
 254                 } else
 255                         log_dbg("Discard/TRIM is not supported by the kernel.");
 256         }
 257
 258         hexkey = crypt_safe_alloc(dmd->vk->keylength * 2 + 1);
 259         if (!hexkey)
 260                 return NULL;
 261
 262         hex_key(hexkey, dmd->vk->keylength, dmd->vk->key);
 263
 264         max_size = strlen(hexkey) + strlen(dmd->cipher) +
 265                    strlen(dmd->device) + strlen(features) + 64;
 266         params = crypt_safe_alloc(max_size);
 267         if (!params)
 268                 goto out;
 269
 270         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 271                      dmd->cipher, hexkey, dmd->iv_offset, dmd->device,
 272                      dmd->offset, features);
 273         if (r < 0 || r >= max_size) {
 274                 crypt_safe_free(params);
 275                 params = NULL;
 276         }
 277 out:
 278         crypt_safe_free(hexkey);
 279         return params;
 280 }
 281
 282 /* DM helpers */
 283 static int _dm_simple(int task, const char *name, int udev_wait)
 284 {
 285         int r = 0;
 286         struct dm_task *dmt;
 287         uint32_t cookie = 0;
 288
 289         if (!_dm_use_udev())
 290                 udev_wait = 0;
 291
 292         if (!(dmt = dm_task_create(task)))
 293                 return 0;
 294
 295         if (name && !dm_task_set_name(dmt, name))
 296                 goto out;
 297
 298 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 299         /* Used only in DM_DEVICE_REMOVE */
 300         if (name && !dm_task_retry_remove(dmt))
 301                 goto out;
 302 #endif
 303         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 304                 goto out;
 305
 306         r = dm_task_run(dmt);
 307
 308         if (udev_wait)
 309                 (void)_dm_udev_wait(cookie);
 310
 311       out:
 312         dm_task_destroy(dmt);
 313         return r;
 314 }
 315
 316 static int _error_device(const char *name, size_t size)
 317 {
 318         struct dm_task *dmt;
 319         int r = 0;
 320
 321         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 322                 return 0;
 323
 324         if (!dm_task_set_name(dmt, name))
 325                 goto error;
 326
 327         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 328                 goto error;
 329
 330         if (!dm_task_set_ro(dmt))
 331                 goto error;
 332
 333         if (!dm_task_no_open_count(dmt))
 334                 goto error;
 335
 336         if (!dm_task_run(dmt))
 337                 goto error;
 338
 339         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 340                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 341                 goto error;
 342         }
 343
 344         r = 1;
 345
 346 error:
 347         dm_task_destroy(dmt);
 348         return r;
 349 }
 350
 351 int dm_remove_device(const char *name, int force, uint64_t size)
 352 {
 353         int r = -EINVAL;
 354         int retries = force ? RETRY_COUNT : 1;
 355         int error_target = 0;
 356
 357         if (!name || (force && !size))
 358                 return -EINVAL;
 359
 360         do {
 361                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 362                 if (--retries && r) {
 363                         log_dbg("WARNING: other process locked internal device %s, %s.",
 364                                 name, retries ? "retrying remove" : "giving up");
 365                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 366                                 debug_processes_using_device(name);
 367                         sleep(1);
 368                         if (force && !error_target) {
 369                                 /* If force flag is set, replace device with error, read-only target.
 370                                  * it should stop processes from reading it and also removed underlying
 371                                  * device from mapping, so it is usable again.
 372                                  * Force flag should be used only for temporary devices, which are
 373                                  * intended to work inside cryptsetup only!
 374                                  * Anyway, if some process try to read temporary cryptsetup device,
 375                                  * it is bug - no other process should try touch it (e.g. udev).
 376                                  */
 377                                 _error_device(name, size);
 378                                 error_target = 1;
 379                         }
 380                 }
 381         } while (r == -EINVAL && retries);
 382
 383         dm_task_update_nodes();
 384
 385         return r;
 386 }
 387
 388 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 389 /*
 390  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 391  * CRYPT-PLAIN-name
 392  * CRYPT-LUKS1-00000000000000000000000000000000-name
 393  * CRYPT-TEMP-name
 394  */
 395 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 396 {
 397         char *ptr, uuid2[UUID_LEN] = {0};
 398         uuid_t uu;
 399         unsigned i = 0;
 400
 401         /* Remove '-' chars */
 402         if (uuid && !uuid_parse(uuid, uu)) {
 403                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 404                         if (uuid[i] != '-') {
 405                                 *ptr = uuid[i];
 406                                 ptr++;
 407                         }
 408         }
 409
 410         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 411                 type ?: "", type ? "-" : "",
 412                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 413                 name);
 414
 415         log_dbg("DM-UUID is %s", buf);
 416         if (i >= buflen)
 417                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 418 }
 419
 420 int dm_create_device(const char *name,
 421                      const char *type,
 422                      struct crypt_dm_active_device *dmd,
 423                      int reload)
 424 {
 425         struct dm_task *dmt = NULL;
 426         struct dm_info dmi;
 427         char *params = NULL;
 428         char dev_uuid[DM_UUID_LEN] = {0};
 429         int r = -EINVAL;
 430         uint32_t read_ahead = 0;
 431         uint32_t cookie = 0;
 432         uint16_t udev_flags = 0;
 433
 434         params = get_params(dmd);
 435         if (!params)
 436                 goto out_no_removal;
 437
 438         if (type && !strncmp(type, "TEMP", 4))
 439                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 440
 441         /* All devices must have DM_UUID, only resize on old device is exception */
 442         if (reload) {
 443                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 444                         goto out_no_removal;
 445
 446                 if (!dm_task_set_name(dmt, name))
 447                         goto out_no_removal;
 448         } else {
 449                 dm_prepare_uuid(name, type, dmd->uuid, dev_uuid, sizeof(dev_uuid));
 450
 451                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 452                         goto out_no_removal;
 453
 454                 if (!dm_task_set_name(dmt, name))
 455                         goto out_no_removal;
 456
 457                 if (!dm_task_set_uuid(dmt, dev_uuid))
 458                         goto out_no_removal;
 459
 460                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 461                         goto out_no_removal;
 462         }
 463
 464         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 465                 goto out_no_removal;
 466         if ((dmd->flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 467                 goto out_no_removal;
 468         if (!dm_task_add_target(dmt, 0, dmd->size, DM_CRYPT_TARGET, params))
 469                 goto out_no_removal;
 470
 471 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 472         if (device_read_ahead(dmd->device, &read_ahead) &&
 473             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 474                 goto out_no_removal;
 475 #endif
 476
 477         if (!dm_task_run(dmt))
 478                 goto out_no_removal;
 479
 480         if (reload) {
 481                 dm_task_destroy(dmt);
 482                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 483                         goto out;
 484                 if (!dm_task_set_name(dmt, name))
 485                         goto out;
 486                 if (dmd->uuid && !dm_task_set_uuid(dmt, dev_uuid))
 487                         goto out;
 488                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 489                         goto out;
 490                 if (!dm_task_run(dmt))
 491                         goto out;
 492         }
 493
 494         if (!dm_task_get_info(dmt, &dmi))
 495                 goto out;
 496
 497         r = 0;
 498 out:
 499         if (_dm_use_udev()) {
 500                 (void)_dm_udev_wait(cookie);
 501                 cookie = 0;
 502         }
 503
 504         if (r < 0 && !reload)
 505                 dm_remove_device(name, 0, 0);
 506
 507 out_no_removal:
 508         if (cookie && _dm_use_udev())
 509                 (void)_dm_udev_wait(cookie);
 510
 511         if (params)
 512                 crypt_safe_free(params);
 513         if (dmt)
 514                 dm_task_destroy(dmt);
 515
 516         dm_task_update_nodes();
 517         return r;
 518 }
 519
 520 static int dm_status_dmi(const char *name, struct dm_info *dmi)
 521 {
 522         struct dm_task *dmt;
 523         uint64_t start, length;
 524         char *target_type, *params;
 525         void *next = NULL;
 526         int r = -EINVAL;
 527
 528         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 529                 goto out;
 530
 531         if (!dm_task_set_name(dmt, name))
 532                 goto out;
 533
 534         if (!dm_task_run(dmt))
 535                 goto out;
 536
 537         if (!dm_task_get_info(dmt, dmi))
 538                 goto out;
 539
 540         if (!dmi->exists) {
 541                 r = -ENODEV;
 542                 goto out;
 543         }
 544
 545         next = dm_get_next_target(dmt, next, &start, &length,
 546                                   &target_type, &params);
 547         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 548             start != 0 || next)
 549                 r = -EINVAL;
 550         else
 551                 r = 0;
 552 out:
 553         if (dmt)
 554                 dm_task_destroy(dmt);
 555
 556         return r;
 557 }
 558
 559 int dm_status_device(const char *name)
 560 {
 561         int r;
 562         struct dm_info dmi;
 563
 564         r = dm_status_dmi(name, &dmi);
 565         if (r < 0)
 566                 return r;
 567
 568         return (dmi.open_count > 0);
 569 }
 570
 571 int dm_status_suspended(const char *name)
 572 {
 573         int r;
 574         struct dm_info dmi;
 575
 576         r = dm_status_dmi(name, &dmi);
 577         if (r < 0)
 578                 return r;
 579
 580         return dmi.suspended ? 1 : 0;
 581 }
 582
 583 int dm_query_device(const char *name, uint32_t get_flags,
 584                     struct crypt_dm_active_device *dmd)
 585 {
 586         struct dm_task *dmt;
 587         struct dm_info dmi;
 588         uint64_t start, length, val64;
 589         char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 590         const char *tmp_uuid;
 591         void *next = NULL;
 592         unsigned int i;
 593         int r = -EINVAL;
 594
 595         memset(dmd, 0, sizeof(*dmd));
 596
 597         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 598                 goto out;
 599         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 600                 goto out;
 601         if (!dm_task_set_name(dmt, name))
 602                 goto out;
 603         r = -ENODEV;
 604         if (!dm_task_run(dmt))
 605                 goto out;
 606
 607         r = -EINVAL;
 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         tmp_uuid = dm_task_get_uuid(dmt);
 617
 618         next = dm_get_next_target(dmt, next, &start, &length,
 619                                   &target_type, &params);
 620         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 621             start != 0 || next)
 622                 goto out;
 623
 624         dmd->size = length;
 625
 626         rcipher = strsep(&params, " ");
 627         /* cipher */
 628         if (get_flags & DM_ACTIVE_CIPHER)
 629                 dmd->cipher = strdup(rcipher);
 630
 631         /* skip */
 632         key_ = strsep(&params, " ");
 633         if (!params)
 634                 goto out;
 635         val64 = strtoull(params, &params, 10);
 636         if (*params != ' ')
 637                 goto out;
 638         params++;
 639
 640         dmd->iv_offset = val64;
 641
 642         /* device */
 643         rdevice = strsep(&params, " ");
 644         if (get_flags & DM_ACTIVE_DEVICE)
 645                 dmd->device = crypt_lookup_dev(rdevice);
 646
 647         /*offset */
 648         if (!params)
 649                 goto out;
 650         val64 = strtoull(params, &params, 10);
 651         dmd->offset = val64;
 652
 653         /* Features section, available since crypt target version 1.11 */
 654         if (*params) {
 655                 if (*params != ' ')
 656                         goto out;
 657                 params++;
 658
 659                 /* Number of arguments */
 660                 val64 = strtoull(params, &params, 10);
 661                 if (*params != ' ')
 662                         goto out;
 663                 params++;
 664
 665                 for (i = 0; i < val64; i++) {
 666                         if (!params)
 667                                 goto out;
 668                         arg = strsep(&params, " ");
 669                         if (!strcasecmp(arg, "allow_discards"))
 670                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 671                         else /* unknown option */
 672                                 goto out;
 673                 }
 674
 675                 /* All parameters shold be processed */
 676                 if (params)
 677                         goto out;
 678         }
 679
 680         /* Never allow to return empty key */
 681         if ((get_flags & DM_ACTIVE_KEY) && dmi.suspended) {
 682                 log_dbg("Cannot read volume key while suspended.");
 683                 r = -EINVAL;
 684                 goto out;
 685         }
 686
 687         if (get_flags & DM_ACTIVE_KEYSIZE) {
 688                 dmd->vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 689                 if (!dmd->vk) {
 690                         r = -ENOMEM;
 691                         goto out;
 692                 }
 693
 694                 if (get_flags & DM_ACTIVE_KEY) {
 695                         buffer[2] = '\0';
 696                         for(i = 0; i < dmd->vk->keylength; i++) {
 697                                 memcpy(buffer, &key_[i * 2], 2);
 698                                 dmd->vk->key[i] = strtoul(buffer, &endp, 16);
 699                                 if (endp != &buffer[2]) {
 700                                         crypt_free_volume_key(dmd->vk);
 701                                         dmd->vk = NULL;
 702                                         r = -EINVAL;
 703                                         goto out;
 704                                 }
 705                         }
 706                 }
 707         }
 708         memset(key_, 0, strlen(key_));
 709
 710         if (dmi.read_only)
 711                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 712
 713         if (!tmp_uuid)
 714                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 715         else if (get_flags & DM_ACTIVE_UUID) {
 716                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 717                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 718         }
 719
 720         r = (dmi.open_count > 0);
 721 out:
 722         if (dmt)
 723                 dm_task_destroy(dmt);
 724
 725         return r;
 726 }
 727
 728 static int _dm_message(const char *name, const char *msg)
 729 {
 730         int r = 0;
 731         struct dm_task *dmt;
 732
 733         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 734                 return 0;
 735
 736         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 737                 goto out;
 738
 739         if (name && !dm_task_set_name(dmt, name))
 740                 goto out;
 741
 742         if (!dm_task_set_sector(dmt, (uint64_t) 0))
 743                 goto out;
 744
 745         if (!dm_task_set_message(dmt, msg))
 746                 goto out;
 747
 748         r = dm_task_run(dmt);
 749
 750       out:
 751         dm_task_destroy(dmt);
 752         return r;
 753 }
 754
 755 int dm_suspend_and_wipe_key(const char *name)
 756 {
 757         if (!_dm_check_versions())
 758                 return -ENOTSUP;
 759
 760         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 761                 return -ENOTSUP;
 762
 763         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
 764                 return -EINVAL;
 765
 766         if (!_dm_message(name, "key wipe")) {
 767                 _dm_simple(DM_DEVICE_RESUME, name, 1);
 768                 return -EINVAL;
 769         }
 770
 771         return 0;
 772 }
 773
 774 int dm_resume_and_reinstate_key(const char *name,
 775                                 size_t key_size,
 776                                 const char *key)
 777 {
 778         int msg_size = key_size * 2 + 10; // key set <key>
 779         char *msg;
 780         int r = 0;
 781
 782         if (!_dm_check_versions())
 783                 return -ENOTSUP;
 784
 785         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 786                 return -ENOTSUP;
 787
 788         msg = crypt_safe_alloc(msg_size);
 789         if (!msg)
 790                 return -ENOMEM;
 791
 792         memset(msg, 0, msg_size);
 793         strcpy(msg, "key set ");
 794         hex_key(&msg[8], key_size, key);
 795
 796         if (!_dm_message(name, msg) ||
 797             !_dm_simple(DM_DEVICE_RESUME, name, 1))
 798                 r = -EINVAL;
 799
 800         crypt_safe_free(msg);
 801         return r;
 802 }
 803
 804 const char *dm_get_dir(void)
 805 {
 806         return dm_dir();
 807 }
 808
 809 int dm_is_dm_device(int major, int minor)
 810 {
 811         return dm_is_dm_major((uint32_t)major);
 812 }
 813
 814 int dm_is_dm_kernel_name(const char *name)
 815 {
 816         return strncmp(name, "dm-", 3) ? 0 : 1;
 817 }
 818
 819 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
 820 {
 821         struct crypt_dm_active_device dmd;
 822         int r;
 823
 824         log_dbg("Checking segments for device %s.", name);
 825
 826         r = dm_query_device(name, 0, &dmd);
 827         if (r < 0)
 828                 return r;
 829
 830         if (offset >= (dmd.offset + dmd.size) || (offset + size) <= dmd.offset)
 831                 r = 0;
 832         else
 833                 r = -EBUSY;
 834
 835         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
 836                dmd.offset, dmd.offset + dmd.size, offset, offset + size,
 837                r ? " (overlapping)" : " (ok)");
 838
 839         return r;
 840 }