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 <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 (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 299                 goto out;
 300
 301         r = dm_task_run(dmt);
 302
 303         if (udev_wait)
 304                 (void)_dm_udev_wait(cookie);
 305
 306       out:
 307         dm_task_destroy(dmt);
 308         return r;
 309 }
 310
 311 static int _error_device(const char *name, size_t size)
 312 {
 313         struct dm_task *dmt;
 314         int r = 0;
 315
 316         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 317                 return 0;
 318
 319         if (!dm_task_set_name(dmt, name))
 320                 goto error;
 321
 322         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 323                 goto error;
 324
 325         if (!dm_task_set_ro(dmt))
 326                 goto error;
 327
 328         if (!dm_task_no_open_count(dmt))
 329                 goto error;
 330
 331         if (!dm_task_run(dmt))
 332                 goto error;
 333
 334         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 335                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 336                 goto error;
 337         }
 338
 339         r = 1;
 340
 341 error:
 342         dm_task_destroy(dmt);
 343         return r;
 344 }
 345
 346 int dm_remove_device(const char *name, int force, uint64_t size)
 347 {
 348         int r = -EINVAL;
 349         int retries = force ? RETRY_COUNT : 1;
 350         int error_target = 0;
 351
 352         if (!name || (force && !size))
 353                 return -EINVAL;
 354
 355         do {
 356                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 357                 if (--retries && r) {
 358                         log_dbg("WARNING: other process locked internal device %s, %s.",
 359                                 name, retries ? "retrying remove" : "giving up");
 360                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 361                                 debug_processes_using_device(name);
 362                         sleep(1);
 363                         if (force && !error_target) {
 364                                 /* If force flag is set, replace device with error, read-only target.
 365                                  * it should stop processes from reading it and also removed underlying
 366                                  * device from mapping, so it is usable again.
 367                                  * Force flag should be used only for temporary devices, which are
 368                                  * intended to work inside cryptsetup only!
 369                                  * Anyway, if some process try to read temporary cryptsetup device,
 370                                  * it is bug - no other process should try touch it (e.g. udev).
 371                                  */
 372                                 _error_device(name, size);
 373                                 error_target = 1;
 374                         }
 375                 }
 376         } while (r == -EINVAL && retries);
 377
 378         dm_task_update_nodes();
 379
 380         return r;
 381 }
 382
 383 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 384 /*
 385  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 386  * CRYPT-PLAIN-name
 387  * CRYPT-LUKS1-00000000000000000000000000000000-name
 388  * CRYPT-TEMP-name
 389  */
 390 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 391 {
 392         char *ptr, uuid2[UUID_LEN] = {0};
 393         uuid_t uu;
 394         unsigned i = 0;
 395
 396         /* Remove '-' chars */
 397         if (uuid && !uuid_parse(uuid, uu)) {
 398                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 399                         if (uuid[i] != '-') {
 400                                 *ptr = uuid[i];
 401                                 ptr++;
 402                         }
 403         }
 404
 405         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 406                 type ?: "", type ? "-" : "",
 407                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 408                 name);
 409
 410         log_dbg("DM-UUID is %s", buf);
 411         if (i >= buflen)
 412                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 413 }
 414
 415 int dm_create_device(const char *name,
 416                      const char *type,
 417                      struct crypt_dm_active_device *dmd,
 418                      int reload)
 419 {
 420         struct dm_task *dmt = NULL;
 421         struct dm_info dmi;
 422         char *params = NULL;
 423         char *error = NULL;
 424         char dev_uuid[DM_UUID_LEN] = {0};
 425         int r = -EINVAL;
 426         uint32_t read_ahead = 0;
 427         uint32_t cookie = 0;
 428         uint16_t udev_flags = 0;
 429
 430         params = get_params(dmd);
 431         if (!params)
 432                 goto out_no_removal;
 433
 434         if (type && !strncmp(type, "TEMP", 4))
 435                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 436
 437         /* All devices must have DM_UUID, only resize on old device is exception */
 438         if (reload) {
 439                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 440                         goto out_no_removal;
 441
 442                 if (!dm_task_set_name(dmt, name))
 443                         goto out_no_removal;
 444         } else {
 445                 dm_prepare_uuid(name, type, dmd->uuid, dev_uuid, sizeof(dev_uuid));
 446
 447                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 448                         goto out_no_removal;
 449
 450                 if (!dm_task_set_name(dmt, name))
 451                         goto out_no_removal;
 452
 453                 if (!dm_task_set_uuid(dmt, dev_uuid))
 454                         goto out_no_removal;
 455
 456                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 457                         goto out_no_removal;
 458         }
 459
 460         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 461                 goto out_no_removal;
 462         if ((dmd->flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 463                 goto out_no_removal;
 464         if (!dm_task_add_target(dmt, 0, dmd->size, DM_CRYPT_TARGET, params))
 465                 goto out_no_removal;
 466
 467 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 468         if (device_read_ahead(dmd->device, &read_ahead) &&
 469             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 470                 goto out_no_removal;
 471 #endif
 472
 473         if (!dm_task_run(dmt))
 474                 goto out_no_removal;
 475
 476         if (reload) {
 477                 dm_task_destroy(dmt);
 478                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 479                         goto out;
 480                 if (!dm_task_set_name(dmt, name))
 481                         goto out;
 482                 if (dmd->uuid && !dm_task_set_uuid(dmt, dev_uuid))
 483                         goto out;
 484                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 485                         goto out;
 486                 if (!dm_task_run(dmt))
 487                         goto out;
 488         }
 489
 490         if (!dm_task_get_info(dmt, &dmi))
 491                 goto out;
 492
 493         r = 0;
 494 out:
 495         if (_dm_use_udev()) {
 496                 (void)_dm_udev_wait(cookie);
 497                 cookie = 0;
 498         }
 499
 500         if (r < 0 && !reload) {
 501                 if (get_error())
 502                         error = strdup(get_error());
 503
 504                 dm_remove_device(name, 0, 0);
 505
 506                 if (error) {
 507                         set_error(error);
 508                         free(error);
 509                 }
 510         }
 511
 512 out_no_removal:
 513         if (cookie && _dm_use_udev())
 514                 (void)_dm_udev_wait(cookie);
 515
 516         if (params)
 517                 crypt_safe_free(params);
 518         if (dmt)
 519                 dm_task_destroy(dmt);
 520
 521         dm_task_update_nodes();
 522         return r;
 523 }
 524
 525 static int dm_status_dmi(const char *name, struct dm_info *dmi)
 526 {
 527         struct dm_task *dmt;
 528         uint64_t start, length;
 529         char *target_type, *params;
 530         void *next = NULL;
 531         int r = -EINVAL;
 532
 533         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 534                 goto out;
 535
 536         if (!dm_task_set_name(dmt, name))
 537                 goto out;
 538
 539         if (!dm_task_run(dmt))
 540                 goto out;
 541
 542         if (!dm_task_get_info(dmt, dmi))
 543                 goto out;
 544
 545         if (!dmi->exists) {
 546                 r = -ENODEV;
 547                 goto out;
 548         }
 549
 550         next = dm_get_next_target(dmt, next, &start, &length,
 551                                   &target_type, &params);
 552         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 553             start != 0 || next)
 554                 r = -EINVAL;
 555         else
 556                 r = 0;
 557 out:
 558         if (dmt)
 559                 dm_task_destroy(dmt);
 560
 561         return r;
 562 }
 563
 564 int dm_status_device(const char *name)
 565 {
 566         int r;
 567         struct dm_info dmi;
 568
 569         r = dm_status_dmi(name, &dmi);
 570         if (r < 0)
 571                 return r;
 572
 573         return (dmi.open_count > 0);
 574 }
 575
 576 int dm_status_suspended(const char *name)
 577 {
 578         int r;
 579         struct dm_info dmi;
 580
 581         r = dm_status_dmi(name, &dmi);
 582         if (r < 0)
 583                 return r;
 584
 585         return dmi.suspended ? 1 : 0;
 586 }
 587
 588 int dm_query_device(const char *name, uint32_t get_flags,
 589                     struct crypt_dm_active_device *dmd)
 590 {
 591         struct dm_task *dmt;
 592         struct dm_info dmi;
 593         uint64_t start, length, val64;
 594         char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 595         const char *tmp_uuid;
 596         void *next = NULL;
 597         unsigned int i;
 598         int r = -EINVAL;
 599
 600         memset(dmd, 0, sizeof(*dmd));
 601
 602         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 603                 goto out;
 604         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 605                 goto out;
 606         if (!dm_task_set_name(dmt, name))
 607                 goto out;
 608         r = -ENODEV;
 609         if (!dm_task_run(dmt))
 610                 goto out;
 611
 612         r = -EINVAL;
 613         if (!dm_task_get_info(dmt, &dmi))
 614                 goto out;
 615
 616         if (!dmi.exists) {
 617                 r = -ENODEV;
 618                 goto out;
 619         }
 620
 621         tmp_uuid = dm_task_get_uuid(dmt);
 622
 623         next = dm_get_next_target(dmt, next, &start, &length,
 624                                   &target_type, &params);
 625         if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
 626             start != 0 || next)
 627                 goto out;
 628
 629         dmd->size = length;
 630
 631         rcipher = strsep(&params, " ");
 632         /* cipher */
 633         if (get_flags & DM_ACTIVE_CIPHER)
 634                 dmd->cipher = strdup(rcipher);
 635
 636         /* skip */
 637         key_ = strsep(&params, " ");
 638         if (!params)
 639                 goto out;
 640         val64 = strtoull(params, &params, 10);
 641         if (*params != ' ')
 642                 goto out;
 643         params++;
 644
 645         dmd->iv_offset = val64;
 646
 647         /* device */
 648         rdevice = strsep(&params, " ");
 649         if (get_flags & DM_ACTIVE_DEVICE)
 650                 dmd->device = crypt_lookup_dev(rdevice);
 651
 652         /*offset */
 653         if (!params)
 654                 goto out;
 655         val64 = strtoull(params, &params, 10);
 656         dmd->offset = val64;
 657
 658         /* Features section, available since crypt target version 1.11 */
 659         if (*params) {
 660                 if (*params != ' ')
 661                         goto out;
 662                 params++;
 663
 664                 /* Number of arguments */
 665                 val64 = strtoull(params, &params, 10);
 666                 if (*params != ' ')
 667                         goto out;
 668                 params++;
 669
 670                 for (i = 0; i < val64; i++) {
 671                         if (!params)
 672                                 goto out;
 673                         arg = strsep(&params, " ");
 674                         if (!strcasecmp(arg, "allow_discards"))
 675                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 676                         else /* unknown option */
 677                                 goto out;
 678                 }
 679
 680                 /* All parameters shold be processed */
 681                 if (params)
 682                         goto out;
 683         }
 684
 685         /* Never allow to return empty key */
 686         if ((get_flags & DM_ACTIVE_KEY) && dmi.suspended) {
 687                 log_dbg("Cannot read volume key while suspended.");
 688                 r = -EINVAL;
 689                 goto out;
 690         }
 691
 692         if (get_flags & DM_ACTIVE_KEYSIZE) {
 693                 dmd->vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 694                 if (!dmd->vk) {
 695                         r = -ENOMEM;
 696                         goto out;
 697                 }
 698
 699                 if (get_flags & DM_ACTIVE_KEY) {
 700                         buffer[2] = '\0';
 701                         for(i = 0; i < dmd->vk->keylength; i++) {
 702                                 memcpy(buffer, &key_[i * 2], 2);
 703                                 dmd->vk->key[i] = strtoul(buffer, &endp, 16);
 704                                 if (endp != &buffer[2]) {
 705                                         crypt_free_volume_key(dmd->vk);
 706                                         dmd->vk = NULL;
 707                                         r = -EINVAL;
 708                                         goto out;
 709                                 }
 710                         }
 711                 }
 712         }
 713         memset(key_, 0, strlen(key_));
 714
 715         if (dmi.read_only)
 716                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 717
 718         if (!tmp_uuid)
 719                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 720         else if (get_flags & DM_ACTIVE_UUID) {
 721                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 722                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 723         }
 724
 725         r = (dmi.open_count > 0);
 726 out:
 727         if (dmt)
 728                 dm_task_destroy(dmt);
 729
 730         return r;
 731 }
 732
 733 static int _dm_message(const char *name, const char *msg)
 734 {
 735         int r = 0;
 736         struct dm_task *dmt;
 737
 738         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 739                 return 0;
 740
 741         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 742                 goto out;
 743
 744         if (name && !dm_task_set_name(dmt, name))
 745                 goto out;
 746
 747         if (!dm_task_set_sector(dmt, (uint64_t) 0))
 748                 goto out;
 749
 750         if (!dm_task_set_message(dmt, msg))
 751                 goto out;
 752
 753         r = dm_task_run(dmt);
 754
 755       out:
 756         dm_task_destroy(dmt);
 757         return r;
 758 }
 759
 760 int dm_suspend_and_wipe_key(const char *name)
 761 {
 762         if (!_dm_check_versions())
 763                 return -ENOTSUP;
 764
 765         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 766                 return -ENOTSUP;
 767
 768         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
 769                 return -EINVAL;
 770
 771         if (!_dm_message(name, "key wipe")) {
 772                 _dm_simple(DM_DEVICE_RESUME, name, 1);
 773                 return -EINVAL;
 774         }
 775
 776         return 0;
 777 }
 778
 779 int dm_resume_and_reinstate_key(const char *name,
 780                                 size_t key_size,
 781                                 const char *key)
 782 {
 783         int msg_size = key_size * 2 + 10; // key set <key>
 784         char *msg;
 785         int r = 0;
 786
 787         if (!_dm_check_versions())
 788                 return -ENOTSUP;
 789
 790         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 791                 return -ENOTSUP;
 792
 793         msg = crypt_safe_alloc(msg_size);
 794         if (!msg)
 795                 return -ENOMEM;
 796
 797         memset(msg, 0, msg_size);
 798         strcpy(msg, "key set ");
 799         hex_key(&msg[8], key_size, key);
 800
 801         if (!_dm_message(name, msg) ||
 802             !_dm_simple(DM_DEVICE_RESUME, name, 1))
 803                 r = -EINVAL;
 804
 805         crypt_safe_free(msg);
 806         return r;
 807 }
 808
 809 const char *dm_get_dir(void)
 810 {
 811         return dm_dir();
 812 }
 813
 814 int dm_is_dm_device(int major, int minor)
 815 {
 816         return dm_is_dm_major((uint32_t)major);
 817 }
 818
 819 int dm_is_dm_kernel_name(const char *name)
 820 {
 821         return strncmp(name, "dm-", 3) ? 0 : 1;
 822 }
 823
 824 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
 825 {
 826         struct crypt_dm_active_device dmd;
 827         int r;
 828
 829         log_dbg("Checking segments for device %s.", name);
 830
 831         r = dm_query_device(name, 0, &dmd);
 832         if (r < 0)
 833                 return r;
 834
 835         if (offset >= (dmd.offset + dmd.size) || (offset + size) <= dmd.offset)
 836                 r = 0;
 837         else
 838                 r = -EBUSY;
 839
 840         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
 841                dmd.offset, dmd.offset + dmd.size, offset, offset + size,
 842                r ? " (overlapping)" : " (ok)");
 843
 844         return r;
 845 }