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
  32 #define DM_UUID_LEN             129
  33 #define DM_UUID_PREFIX          "CRYPT-"
  34 #define DM_UUID_PREFIX_LEN      6
  35 #define DM_CRYPT_TARGET         "crypt"
  36 #define DM_VERITY_TARGET        "verity"
  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 void _dm_set_verity_compat(const char *dm_version, unsigned verity_maj,
 131                                    unsigned verity_min, unsigned verity_patch)
 132 {
 133         if (verity_maj > 0)
 134                 _dm_crypt_flags |= DM_VERITY_SUPPORTED;
 135
 136         log_dbg("Detected dm-verity version %i.%i.%i.",
 137                 verity_maj, verity_min, verity_patch);
 138 }
 139
 140 static int _dm_check_versions(void)
 141 {
 142         struct dm_task *dmt;
 143         struct dm_versions *target, *last_target;
 144         char dm_version[16];
 145
 146         if (_dm_crypt_checked)
 147                 return 1;
 148
 149         /* FIXME: add support to DM so it forces crypt target module load here */
 150         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 151                 return 0;
 152
 153         if (!dm_task_run(dmt)) {
 154                 dm_task_destroy(dmt);
 155                 return 0;
 156         }
 157
 158         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 159                 dm_task_destroy(dmt);
 160                 return 0;
 161         }
 162
 163         target = dm_task_get_versions(dmt);
 164         do {
 165                 last_target = target;
 166                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 167                         _dm_set_crypt_compat(dm_version,
 168                                              (unsigned)target->version[0],
 169                                              (unsigned)target->version[1],
 170                                              (unsigned)target->version[2]);
 171                 } else if (!strcmp(DM_VERITY_TARGET, target->name)) {
 172                         _dm_set_verity_compat(dm_version,
 173                                              (unsigned)target->version[0],
 174                                              (unsigned)target->version[1],
 175                                              (unsigned)target->version[2]);
 176                 }
 177                 target = (struct dm_versions *)((char *) target + target->next);
 178         } while (last_target != target);
 179
 180         dm_task_destroy(dmt);
 181         return 1;
 182 }
 183
 184 uint32_t dm_flags(void)
 185 {
 186         if (!_dm_crypt_checked)
 187                 _dm_check_versions();
 188
 189         return _dm_crypt_flags;
 190 }
 191
 192 int dm_init(struct crypt_device *context, int check_kernel)
 193 {
 194         if (!_dm_use_count++) {
 195                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 196                         check_kernel ? "" : " (NO kernel check requested)",
 197                         _dm_use_udev() ? "en" : "dis");
 198                 if (check_kernel && !_dm_check_versions()) {
 199                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 200                         return -1;
 201                 }
 202                 if (getuid() || geteuid())
 203                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 204                 dm_log_init(set_dm_error);
 205                 dm_log_init_verbose(10);
 206         }
 207
 208         // FIXME: global context is not safe
 209         if (context)
 210                 _context = context;
 211
 212         return 1;       /* unsafe memory */
 213 }
 214
 215 void dm_exit(void)
 216 {
 217         if (_dm_use_count && (!--_dm_use_count)) {
 218                 log_dbg("Releasing device-mapper backend.");
 219                 dm_log_init_verbose(0);
 220                 dm_log_init(NULL);
 221                 dm_lib_release();
 222                 _context = NULL;
 223         }
 224 }
 225
 226 /* Return path to DM device */
 227 char *dm_device_path(const char *prefix, int major, int minor)
 228 {
 229         struct dm_task *dmt;
 230         const char *name;
 231         char path[PATH_MAX];
 232
 233         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 234                 return NULL;
 235         if (!dm_task_set_minor(dmt, minor) ||
 236             !dm_task_set_major(dmt, major) ||
 237             !dm_task_run(dmt) ||
 238             !(name = dm_task_get_name(dmt))) {
 239                 dm_task_destroy(dmt);
 240                 return NULL;
 241         }
 242
 243         if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
 244                 path[0] = '\0';
 245
 246         dm_task_destroy(dmt);
 247
 248         return strdup(path);
 249 }
 250
 251 static void hex_key(char *hexkey, size_t key_size, const char *key)
 252 {
 253         unsigned i;
 254
 255         for(i = 0; i < key_size; i++)
 256                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 257 }
 258
 259 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 260 {
 261         int r, max_size, null_cipher = 0;
 262         char *params, *hexkey;
 263         const char *features = "";
 264
 265         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 266                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 267                         features = " 1 allow_discards";
 268                         log_dbg("Discard/TRIM is allowed.");
 269                 } else
 270                         log_dbg("Discard/TRIM is not supported by the kernel.");
 271         }
 272
 273         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 274                 null_cipher = 1;
 275
 276         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 277         if (!hexkey)
 278                 return NULL;
 279
 280         if (null_cipher)
 281                 strncpy(hexkey, "-", 2);
 282         else
 283                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 284
 285         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 286                    strlen(dmd->u.crypt.device) + strlen(features) + 64;
 287         params = crypt_safe_alloc(max_size);
 288         if (!params)
 289                 goto out;
 290
 291         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 292                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 293                      dmd->u.crypt.device, dmd->u.crypt.offset, features);
 294         if (r < 0 || r >= max_size) {
 295                 crypt_safe_free(params);
 296                 params = NULL;
 297         }
 298 out:
 299         crypt_safe_free(hexkey);
 300         return params;
 301 }
 302 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 303                                    struct crypt_dm_active_device *dmd)
 304 {
 305         int max_size, r;
 306         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 307
 308         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 309         if (!hexroot)
 310                 goto out;
 311         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 312
 313         hexsalt = crypt_safe_alloc(vp->salt_size * 2 + 1);
 314         if (!hexsalt)
 315                 goto out;
 316         hex_key(hexsalt, vp->salt_size, vp->salt);
 317
 318         max_size = strlen(hexroot) + strlen(hexsalt) +
 319                    strlen(dmd->u.verity.data_device) +
 320                    strlen(dmd->u.verity.hash_device) +
 321                    strlen(vp->hash_name) + 128;
 322
 323         params = crypt_safe_alloc(max_size);
 324         if (!params)
 325                 goto out;
 326
 327         r = snprintf(params, max_size,
 328                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 329                      vp->version, dmd->u.verity.data_device,
 330                      dmd->u.verity.hash_device,
 331                      vp->data_block_size, vp->hash_block_size,
 332                      vp->data_size, dmd->u.verity.hash_offset,
 333                      vp->hash_name, hexroot, hexsalt);
 334         if (r < 0 || r >= max_size) {
 335                 crypt_safe_free(params);
 336                 params = NULL;
 337         }
 338         log_dbg("TABLE: %s", params);
 339 out:
 340         crypt_safe_free(hexroot);
 341         crypt_safe_free(hexsalt);
 342         return params;
 343
 344 }
 345
 346 /* DM helpers */
 347 static int _dm_simple(int task, const char *name, int udev_wait)
 348 {
 349         int r = 0;
 350         struct dm_task *dmt;
 351         uint32_t cookie = 0;
 352
 353         if (!_dm_use_udev())
 354                 udev_wait = 0;
 355
 356         if (!(dmt = dm_task_create(task)))
 357                 return 0;
 358
 359         if (name && !dm_task_set_name(dmt, name))
 360                 goto out;
 361
 362 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 363         /* Used only in DM_DEVICE_REMOVE */
 364         if (name && !dm_task_retry_remove(dmt))
 365                 goto out;
 366 #endif
 367         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 368                 goto out;
 369
 370         r = dm_task_run(dmt);
 371
 372         if (udev_wait)
 373                 (void)_dm_udev_wait(cookie);
 374
 375       out:
 376         dm_task_destroy(dmt);
 377         return r;
 378 }
 379
 380 static int _error_device(const char *name, size_t size)
 381 {
 382         struct dm_task *dmt;
 383         int r = 0;
 384
 385         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 386                 return 0;
 387
 388         if (!dm_task_set_name(dmt, name))
 389                 goto error;
 390
 391         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 392                 goto error;
 393
 394         if (!dm_task_set_ro(dmt))
 395                 goto error;
 396
 397         if (!dm_task_no_open_count(dmt))
 398                 goto error;
 399
 400         if (!dm_task_run(dmt))
 401                 goto error;
 402
 403         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 404                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 405                 goto error;
 406         }
 407
 408         r = 1;
 409
 410 error:
 411         dm_task_destroy(dmt);
 412         return r;
 413 }
 414
 415 int dm_remove_device(const char *name, int force, uint64_t size)
 416 {
 417         int r = -EINVAL;
 418         int retries = force ? RETRY_COUNT : 1;
 419         int error_target = 0;
 420
 421         if (!name || (force && !size))
 422                 return -EINVAL;
 423
 424         do {
 425                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 426                 if (--retries && r) {
 427                         log_dbg("WARNING: other process locked internal device %s, %s.",
 428                                 name, retries ? "retrying remove" : "giving up");
 429                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 430                                 debug_processes_using_device(name);
 431                         sleep(1);
 432                         if (force && !error_target) {
 433                                 /* If force flag is set, replace device with error, read-only target.
 434                                  * it should stop processes from reading it and also removed underlying
 435                                  * device from mapping, so it is usable again.
 436                                  * Force flag should be used only for temporary devices, which are
 437                                  * intended to work inside cryptsetup only!
 438                                  * Anyway, if some process try to read temporary cryptsetup device,
 439                                  * it is bug - no other process should try touch it (e.g. udev).
 440                                  */
 441                                 _error_device(name, size);
 442                                 error_target = 1;
 443                         }
 444                 }
 445         } while (r == -EINVAL && retries);
 446
 447         dm_task_update_nodes();
 448
 449         return r;
 450 }
 451
 452 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 453 /*
 454  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 455  * CRYPT-PLAIN-name
 456  * CRYPT-LUKS1-00000000000000000000000000000000-name
 457  * CRYPT-TEMP-name
 458  */
 459 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 460 {
 461         char *ptr, uuid2[UUID_LEN] = {0};
 462         uuid_t uu;
 463         unsigned i = 0;
 464
 465         /* Remove '-' chars */
 466         if (uuid && !uuid_parse(uuid, uu)) {
 467                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 468                         if (uuid[i] != '-') {
 469                                 *ptr = uuid[i];
 470                                 ptr++;
 471                         }
 472         }
 473
 474         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 475                 type ?: "", type ? "-" : "",
 476                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 477                 name);
 478
 479         log_dbg("DM-UUID is %s", buf);
 480         if (i >= buflen)
 481                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 482 }
 483
 484 static int _dm_create_device(const char *name, const char *type,
 485                              const char *device, uint32_t flags,
 486                              const char *uuid, uint64_t size,
 487                              char *params, int reload)
 488 {
 489         struct dm_task *dmt = NULL;
 490         struct dm_info dmi;
 491         char dev_uuid[DM_UUID_LEN] = {0};
 492         int r = -EINVAL;
 493         uint32_t read_ahead = 0;
 494         uint32_t cookie = 0;
 495         uint16_t udev_flags = 0;
 496
 497         if (flags & CRYPT_ACTIVATE_PRIVATE)
 498                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 499
 500         /* All devices must have DM_UUID, only resize on old device is exception */
 501         if (reload) {
 502                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 503                         goto out_no_removal;
 504
 505                 if (!dm_task_set_name(dmt, name))
 506                         goto out_no_removal;
 507         } else {
 508                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 509
 510                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 511                         goto out_no_removal;
 512
 513                 if (!dm_task_set_name(dmt, name))
 514                         goto out_no_removal;
 515
 516                 if (!dm_task_set_uuid(dmt, dev_uuid))
 517                         goto out_no_removal;
 518
 519                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 520                         goto out_no_removal;
 521         }
 522
 523         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 524                 goto out_no_removal;
 525         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 526                 goto out_no_removal;
 527
 528         if (!dm_task_add_target(dmt, 0, size,
 529                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 530                 goto out_no_removal;
 531
 532 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 533         if (device_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                 dm_remove_device(name, 0, 0);
 567
 568 out_no_removal:
 569         if (cookie && _dm_use_udev())
 570                 (void)_dm_udev_wait(cookie);
 571
 572         if (params)
 573                 crypt_safe_free(params);
 574         if (dmt)
 575                 dm_task_destroy(dmt);
 576
 577         dm_task_update_nodes();
 578         return r;
 579 }
 580
 581 int dm_create_device(const char *name,
 582                      const char *type,
 583                      struct crypt_dm_active_device *dmd,
 584                      void *params,
 585                      int reload)
 586 {
 587         char *table_params = NULL;
 588
 589         if (dmd->target == DM_CRYPT)
 590                 table_params = get_dm_crypt_params(dmd);
 591         else if (dmd->target == DM_VERITY)
 592                 table_params = get_dm_verity_params(params, dmd);
 593
 594         if (!table_params)
 595                 return -EINVAL;
 596
 597         return _dm_create_device(name, type, dmd->u.crypt.device, dmd->flags,
 598                                  dmd->uuid, dmd->size, table_params, reload);
 599 }
 600
 601 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 602                           const char *target, char **status_line)
 603 {
 604         struct dm_task *dmt;
 605         uint64_t start, length;
 606         char *target_type, *params = NULL;
 607         void *next = NULL;
 608         int r = -EINVAL;
 609
 610         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 611                 goto out;
 612
 613         if (!dm_task_set_name(dmt, name))
 614                 goto out;
 615
 616         if (!dm_task_run(dmt))
 617                 goto out;
 618
 619         if (!dm_task_get_info(dmt, dmi))
 620                 goto out;
 621
 622         if (!dmi->exists) {
 623                 r = -ENODEV;
 624                 goto out;
 625         }
 626
 627         next = dm_get_next_target(dmt, next, &start, &length,
 628                                   &target_type, &params);
 629         if (!target_type || strcmp(target_type, target) != 0 ||
 630             start != 0 || next)
 631                 r = -EINVAL;
 632         else
 633                 r = 0;
 634 out:
 635         if (!r && status_line && !(*status_line = strdup(params)))
 636                 r = -ENOMEM;
 637
 638         if (dmt)
 639                 dm_task_destroy(dmt);
 640
 641         return r;
 642 }
 643
 644 int dm_status_device(const char *name)
 645 {
 646         int r;
 647         struct dm_info dmi;
 648
 649         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 650         if (r < 0)
 651                 return r;
 652
 653         return (dmi.open_count > 0);
 654 }
 655
 656 int dm_status_suspended(const char *name)
 657 {
 658         int r;
 659         struct dm_info dmi;
 660
 661         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 662         if (r < 0)
 663                 return r;
 664
 665         return dmi.suspended ? 1 : 0;
 666 }
 667
 668 int dm_status_verity_ok(const char *name)
 669 {
 670         int r;
 671         struct dm_info dmi;
 672         char *status_line = NULL;
 673
 674         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 675         if (r < 0 || !status_line) {
 676                 free(status_line);
 677                 return r;
 678         }
 679
 680         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 681         r = status_line[0] == 'V' ? 1 : 0;
 682         free(status_line);
 683
 684         return r;
 685 }
 686
 687 static int _dm_query_crypt(uint32_t get_flags,
 688                            struct dm_info *dmi,
 689                            char *params,
 690                            struct crypt_dm_active_device *dmd)
 691 {
 692         uint64_t val64;
 693         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 694         unsigned int i;
 695
 696         dmd->target = DM_CRYPT;
 697
 698         rcipher = strsep(&params, " ");
 699         /* cipher */
 700         if (get_flags & DM_ACTIVE_CIPHER)
 701                 dmd->u.crypt.cipher = strdup(rcipher);
 702
 703         /* skip */
 704         key_ = strsep(&params, " ");
 705         if (!params)
 706                 return -EINVAL;
 707         val64 = strtoull(params, &params, 10);
 708         if (*params != ' ')
 709                 return -EINVAL;
 710         params++;
 711
 712         dmd->u.crypt.iv_offset = val64;
 713
 714         /* device */
 715         rdevice = strsep(&params, " ");
 716         if (get_flags & DM_ACTIVE_DEVICE)
 717                 dmd->u.crypt.device = crypt_lookup_dev(rdevice);
 718
 719         /*offset */
 720         if (!params)
 721                 return -EINVAL;
 722         val64 = strtoull(params, &params, 10);
 723         dmd->u.crypt.offset = val64;
 724
 725         /* Features section, available since crypt target version 1.11 */
 726         if (*params) {
 727                 if (*params != ' ')
 728                         return -EINVAL;
 729                 params++;
 730
 731                 /* Number of arguments */
 732                 val64 = strtoull(params, &params, 10);
 733                 if (*params != ' ')
 734                         return -EINVAL;
 735                 params++;
 736
 737                 for (i = 0; i < val64; i++) {
 738                         if (!params)
 739                                 return -EINVAL;
 740                         arg = strsep(&params, " ");
 741                         if (!strcasecmp(arg, "allow_discards"))
 742                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 743                         else /* unknown option */
 744                                 return -EINVAL;
 745                 }
 746
 747                 /* All parameters shold be processed */
 748                 if (params)
 749                         return -EINVAL;
 750         }
 751
 752         /* Never allow to return empty key */
 753         if ((get_flags & DM_ACTIVE_KEY) && dmi->suspended) {
 754                 log_dbg("Cannot read volume key while suspended.");
 755                 return -EINVAL;
 756         }
 757
 758         if (get_flags & DM_ACTIVE_KEYSIZE) {
 759                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 760                 if (!dmd->u.crypt.vk)
 761                         return -ENOMEM;
 762
 763                 if (get_flags & DM_ACTIVE_KEY) {
 764                         buffer[2] = '\0';
 765                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 766                                 memcpy(buffer, &key_[i * 2], 2);
 767                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 768                                 if (endp != &buffer[2]) {
 769                                         crypt_free_volume_key(dmd->u.crypt.vk);
 770                                         dmd->u.crypt.vk = NULL;
 771                                         return -EINVAL;
 772                                 }
 773                         }
 774                 }
 775         }
 776         memset(key_, 0, strlen(key_));
 777
 778         return 0;
 779 }
 780
 781 static int _dm_query_verity(uint32_t get_flags,
 782                              struct dm_info *dmi,
 783                              char *params,
 784                              struct crypt_dm_active_device *dmd)
 785 {
 786         dmd->target = DM_VERITY;
 787         return -EINVAL;
 788 }
 789
 790 int dm_query_device(const char *name, uint32_t get_flags,
 791                     struct crypt_dm_active_device *dmd)
 792 {
 793         struct dm_task *dmt;
 794         struct dm_info dmi;
 795         uint64_t start, length;
 796         char *target_type, *params;
 797         const char *tmp_uuid;
 798         void *next = NULL;
 799         int r = -EINVAL;
 800
 801         memset(dmd, 0, sizeof(*dmd));
 802
 803         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 804                 goto out;
 805         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 806                 goto out;
 807         if (!dm_task_set_name(dmt, name))
 808                 goto out;
 809         r = -ENODEV;
 810         if (!dm_task_run(dmt))
 811                 goto out;
 812
 813         r = -EINVAL;
 814         if (!dm_task_get_info(dmt, &dmi))
 815                 goto out;
 816
 817         if (!dmi.exists) {
 818                 r = -ENODEV;
 819                 goto out;
 820         }
 821
 822         next = dm_get_next_target(dmt, next, &start, &length,
 823                                   &target_type, &params);
 824
 825         if (!target_type || start != 0 || next)
 826                 goto out;
 827
 828         if (!strcmp(target_type, DM_CRYPT_TARGET))
 829                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
 830         else if (!strcmp(target_type, DM_VERITY_TARGET))
 831                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
 832         else
 833                 r = -EINVAL;
 834
 835         if (r < 0)
 836                 goto out;
 837
 838         dmd->size = length;
 839
 840         if (dmi.read_only)
 841                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 842
 843         tmp_uuid = dm_task_get_uuid(dmt);
 844         if (!tmp_uuid)
 845                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 846         else if (get_flags & DM_ACTIVE_UUID) {
 847                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 848                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 849         }
 850
 851         r = (dmi.open_count > 0);
 852 out:
 853         if (dmt)
 854                 dm_task_destroy(dmt);
 855
 856         return r;
 857 }
 858
 859 static int _dm_message(const char *name, const char *msg)
 860 {
 861         int r = 0;
 862         struct dm_task *dmt;
 863
 864         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 865                 return 0;
 866
 867         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 868                 goto out;
 869
 870         if (name && !dm_task_set_name(dmt, name))
 871                 goto out;
 872
 873         if (!dm_task_set_sector(dmt, (uint64_t) 0))
 874                 goto out;
 875
 876         if (!dm_task_set_message(dmt, msg))
 877                 goto out;
 878
 879         r = dm_task_run(dmt);
 880
 881       out:
 882         dm_task_destroy(dmt);
 883         return r;
 884 }
 885
 886 int dm_suspend_and_wipe_key(const char *name)
 887 {
 888         if (!_dm_check_versions())
 889                 return -ENOTSUP;
 890
 891         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 892                 return -ENOTSUP;
 893
 894         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
 895                 return -EINVAL;
 896
 897         if (!_dm_message(name, "key wipe")) {
 898                 _dm_simple(DM_DEVICE_RESUME, name, 1);
 899                 return -EINVAL;
 900         }
 901
 902         return 0;
 903 }
 904
 905 int dm_resume_and_reinstate_key(const char *name,
 906                                 size_t key_size,
 907                                 const char *key)
 908 {
 909         int msg_size = key_size * 2 + 10; // key set <key>
 910         char *msg;
 911         int r = 0;
 912
 913         if (!_dm_check_versions())
 914                 return -ENOTSUP;
 915
 916         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
 917                 return -ENOTSUP;
 918
 919         msg = crypt_safe_alloc(msg_size);
 920         if (!msg)
 921                 return -ENOMEM;
 922
 923         memset(msg, 0, msg_size);
 924         strcpy(msg, "key set ");
 925         hex_key(&msg[8], key_size, key);
 926
 927         if (!_dm_message(name, msg) ||
 928             !_dm_simple(DM_DEVICE_RESUME, name, 1))
 929                 r = -EINVAL;
 930
 931         crypt_safe_free(msg);
 932         return r;
 933 }
 934
 935 const char *dm_get_dir(void)
 936 {
 937         return dm_dir();
 938 }
 939
 940 int dm_is_dm_device(int major, int minor)
 941 {
 942         return dm_is_dm_major((uint32_t)major);
 943 }
 944
 945 int dm_is_dm_kernel_name(const char *name)
 946 {
 947         return strncmp(name, "dm-", 3) ? 0 : 1;
 948 }
 949
 950 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
 951 {
 952         struct crypt_dm_active_device dmd;
 953         int r;
 954
 955         log_dbg("Checking segments for device %s.", name);
 956
 957         r = dm_query_device(name, 0, &dmd);
 958         if (r < 0)
 959                 return r;
 960
 961         if (offset >= (dmd.u.crypt.offset + dmd.size) ||
 962            (offset + size) <= dmd.u.crypt.offset)
 963                 r = 0;
 964         else
 965                 r = -EBUSY;
 966
 967         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
 968                dmd.u.crypt.offset, dmd.u.crypt.offset + dmd.size, offset, offset + size,
 969                r ? " (overlapping)" : " (ok)");
 970
 971         return r;
 972 }