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 /* http://code.google.com/p/cryptsetup/wiki/DMCrypt */
 260 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 261 {
 262         int r, max_size, null_cipher = 0;
 263         char *params, *hexkey;
 264         const char *features = "";
 265
 266         if (!dmd)
 267                 return NULL;
 268
 269         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 270                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 271                         features = " 1 allow_discards";
 272                         log_dbg("Discard/TRIM is allowed.");
 273                 } else
 274                         log_dbg("Discard/TRIM is not supported by the kernel.");
 275         }
 276
 277         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 278                 null_cipher = 1;
 279
 280         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 281         if (!hexkey)
 282                 return NULL;
 283
 284         if (null_cipher)
 285                 strncpy(hexkey, "-", 2);
 286         else
 287                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 288
 289         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 290                    strlen(dmd->data_device) + strlen(features) + 64;
 291         params = crypt_safe_alloc(max_size);
 292         if (!params)
 293                 goto out;
 294
 295         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 296                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 297                      dmd->data_device, dmd->u.crypt.offset, features);
 298         if (r < 0 || r >= max_size) {
 299                 crypt_safe_free(params);
 300                 params = NULL;
 301         }
 302 out:
 303         crypt_safe_free(hexkey);
 304         return params;
 305 }
 306
 307 /* http://code.google.com/p/cryptsetup/wiki/DMVerity */
 308 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 309                                    struct crypt_dm_active_device *dmd)
 310 {
 311         int max_size, r;
 312         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 313
 314         if (!vp || !dmd)
 315                 return NULL;
 316
 317         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 318         if (!hexroot)
 319                 goto out;
 320         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 321
 322         hexsalt = crypt_safe_alloc(vp->salt_size ? vp->salt_size * 2 + 1 : 2);
 323         if (!hexsalt)
 324                 goto out;
 325         if (vp->salt_size)
 326                 hex_key(hexsalt, vp->salt_size, vp->salt);
 327         else
 328                 strncpy(hexsalt, "-", 2);
 329
 330         max_size = strlen(hexroot) + strlen(hexsalt) +
 331                    strlen(dmd->data_device) +
 332                    strlen(dmd->u.verity.hash_device) +
 333                    strlen(vp->hash_name) + 128;
 334
 335         params = crypt_safe_alloc(max_size);
 336         if (!params)
 337                 goto out;
 338
 339         r = snprintf(params, max_size,
 340                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 341                      vp->hash_type, dmd->data_device,
 342                      dmd->u.verity.hash_device,
 343                      vp->data_block_size, vp->hash_block_size,
 344                      vp->data_size, dmd->u.verity.hash_offset,
 345                      vp->hash_name, hexroot, hexsalt);
 346         if (r < 0 || r >= max_size) {
 347                 crypt_safe_free(params);
 348                 params = NULL;
 349         }
 350 out:
 351         crypt_safe_free(hexroot);
 352         crypt_safe_free(hexsalt);
 353         return params;
 354
 355 }
 356
 357 /* DM helpers */
 358 static int _dm_simple(int task, const char *name, int udev_wait)
 359 {
 360         int r = 0;
 361         struct dm_task *dmt;
 362         uint32_t cookie = 0;
 363
 364         if (!_dm_use_udev())
 365                 udev_wait = 0;
 366
 367         if (!(dmt = dm_task_create(task)))
 368                 return 0;
 369
 370         if (name && !dm_task_set_name(dmt, name))
 371                 goto out;
 372
 373 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 374         /* Used only in DM_DEVICE_REMOVE */
 375         if (name && !dm_task_retry_remove(dmt))
 376                 goto out;
 377 #endif
 378         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 379                 goto out;
 380
 381         r = dm_task_run(dmt);
 382
 383         if (udev_wait)
 384                 (void)_dm_udev_wait(cookie);
 385
 386       out:
 387         dm_task_destroy(dmt);
 388         return r;
 389 }
 390
 391 static int _error_device(const char *name, size_t size)
 392 {
 393         struct dm_task *dmt;
 394         int r = 0;
 395
 396         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 397                 return 0;
 398
 399         if (!dm_task_set_name(dmt, name))
 400                 goto error;
 401
 402         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 403                 goto error;
 404
 405         if (!dm_task_set_ro(dmt))
 406                 goto error;
 407
 408         if (!dm_task_no_open_count(dmt))
 409                 goto error;
 410
 411         if (!dm_task_run(dmt))
 412                 goto error;
 413
 414         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 415                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 416                 goto error;
 417         }
 418
 419         r = 1;
 420
 421 error:
 422         dm_task_destroy(dmt);
 423         return r;
 424 }
 425
 426 int dm_remove_device(const char *name, int force, uint64_t size)
 427 {
 428         int r = -EINVAL;
 429         int retries = force ? RETRY_COUNT : 1;
 430         int error_target = 0;
 431
 432         if (!name || (force && !size))
 433                 return -EINVAL;
 434
 435         do {
 436                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 437                 if (--retries && r) {
 438                         log_dbg("WARNING: other process locked internal device %s, %s.",
 439                                 name, retries ? "retrying remove" : "giving up");
 440                         sleep(1);
 441                         if (force && !error_target) {
 442                                 /* If force flag is set, replace device with error, read-only target.
 443                                  * it should stop processes from reading it and also removed underlying
 444                                  * device from mapping, so it is usable again.
 445                                  * Force flag should be used only for temporary devices, which are
 446                                  * intended to work inside cryptsetup only!
 447                                  * Anyway, if some process try to read temporary cryptsetup device,
 448                                  * it is bug - no other process should try touch it (e.g. udev).
 449                                  */
 450                                 _error_device(name, size);
 451                                 error_target = 1;
 452                         }
 453                 }
 454         } while (r == -EINVAL && retries);
 455
 456         dm_task_update_nodes();
 457
 458         return r;
 459 }
 460
 461 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 462 /*
 463  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 464  * CRYPT-PLAIN-name
 465  * CRYPT-LUKS1-00000000000000000000000000000000-name
 466  * CRYPT-TEMP-name
 467  */
 468 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 469 {
 470         char *ptr, uuid2[UUID_LEN] = {0};
 471         uuid_t uu;
 472         unsigned i = 0;
 473
 474         /* Remove '-' chars */
 475         if (uuid && !uuid_parse(uuid, uu)) {
 476                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 477                         if (uuid[i] != '-') {
 478                                 *ptr = uuid[i];
 479                                 ptr++;
 480                         }
 481         }
 482
 483         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 484                 type ?: "", type ? "-" : "",
 485                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 486                 name);
 487
 488         log_dbg("DM-UUID is %s", buf);
 489         if (i >= buflen)
 490                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 491 }
 492
 493 static int _dm_create_device(const char *name, const char *type,
 494                              const char *device, uint32_t flags,
 495                              const char *uuid, uint64_t size,
 496                              char *params, int reload)
 497 {
 498         struct dm_task *dmt = NULL;
 499         struct dm_info dmi;
 500         char dev_uuid[DM_UUID_LEN] = {0};
 501         int r = -EINVAL;
 502         uint32_t read_ahead = 0;
 503         uint32_t cookie = 0;
 504         uint16_t udev_flags = 0;
 505
 506         if (flags & CRYPT_ACTIVATE_PRIVATE)
 507                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 508
 509         /* All devices must have DM_UUID, only resize on old device is exception */
 510         if (reload) {
 511                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 512                         goto out_no_removal;
 513
 514                 if (!dm_task_set_name(dmt, name))
 515                         goto out_no_removal;
 516         } else {
 517                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 518
 519                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 520                         goto out_no_removal;
 521
 522                 if (!dm_task_set_name(dmt, name))
 523                         goto out_no_removal;
 524
 525                 if (!dm_task_set_uuid(dmt, dev_uuid))
 526                         goto out_no_removal;
 527
 528                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 529                         goto out_no_removal;
 530         }
 531
 532         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 533                 goto out_no_removal;
 534         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 535                 goto out_no_removal;
 536
 537         if (!dm_task_add_target(dmt, 0, size,
 538                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 539                 goto out_no_removal;
 540
 541 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 542         if (device_read_ahead(device, &read_ahead) &&
 543             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 544                 goto out_no_removal;
 545 #endif
 546
 547         if (!dm_task_run(dmt))
 548                 goto out_no_removal;
 549
 550         if (reload) {
 551                 dm_task_destroy(dmt);
 552                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 553                         goto out;
 554                 if (!dm_task_set_name(dmt, name))
 555                         goto out;
 556                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 557                         goto out;
 558                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 559                         goto out;
 560                 if (!dm_task_run(dmt))
 561                         goto out;
 562         }
 563
 564         if (!dm_task_get_info(dmt, &dmi))
 565                 goto out;
 566
 567         r = 0;
 568 out:
 569         if (_dm_use_udev()) {
 570                 (void)_dm_udev_wait(cookie);
 571                 cookie = 0;
 572         }
 573
 574         if (r < 0 && !reload)
 575                 dm_remove_device(name, 0, 0);
 576
 577 out_no_removal:
 578         if (cookie && _dm_use_udev())
 579                 (void)_dm_udev_wait(cookie);
 580
 581         if (params)
 582                 crypt_safe_free(params);
 583         if (dmt)
 584                 dm_task_destroy(dmt);
 585
 586         dm_task_update_nodes();
 587         return r;
 588 }
 589
 590 int dm_create_device(const char *name,
 591                      const char *type,
 592                      struct crypt_dm_active_device *dmd,
 593                      int reload)
 594 {
 595         char *table_params = NULL;
 596
 597         if (dmd->target == DM_CRYPT)
 598                 table_params = get_dm_crypt_params(dmd);
 599         else if (dmd->target == DM_VERITY)
 600                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 601
 602         if (!table_params || !type)
 603                 return -EINVAL;
 604
 605         return _dm_create_device(name, type, dmd->data_device, dmd->flags,
 606                                  dmd->uuid, dmd->size, table_params, reload);
 607 }
 608
 609 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 610                           const char *target, char **status_line)
 611 {
 612         struct dm_task *dmt;
 613         uint64_t start, length;
 614         char *target_type, *params = NULL;
 615         void *next = NULL;
 616         int r = -EINVAL;
 617
 618         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 619                 goto out;
 620
 621         if (!dm_task_set_name(dmt, name))
 622                 goto out;
 623
 624         if (!dm_task_run(dmt))
 625                 goto out;
 626
 627         if (!dm_task_get_info(dmt, dmi))
 628                 goto out;
 629
 630         if (!dmi->exists) {
 631                 r = -ENODEV;
 632                 goto out;
 633         }
 634
 635         next = dm_get_next_target(dmt, next, &start, &length,
 636                                   &target_type, &params);
 637
 638         if (!target_type || start != 0 || next)
 639                 goto out;
 640
 641         if (target && strcmp(target_type, target))
 642                 goto out;
 643
 644         /* for target == NULL check all supported */
 645         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 646                         strcmp(target_type, DM_VERITY_TARGET)))
 647                 goto out;
 648         r = 0;
 649 out:
 650         if (!r && status_line && !(*status_line = strdup(params)))
 651                 r = -ENOMEM;
 652
 653         if (dmt)
 654                 dm_task_destroy(dmt);
 655
 656         return r;
 657 }
 658
 659 int dm_status_device(const char *name)
 660 {
 661         int r;
 662         struct dm_info dmi;
 663
 664         r = dm_status_dmi(name, &dmi, NULL, NULL);
 665         if (r < 0)
 666                 return r;
 667
 668         return (dmi.open_count > 0);
 669 }
 670
 671 int dm_status_suspended(const char *name)
 672 {
 673         int r;
 674         struct dm_info dmi;
 675
 676         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 677         if (r < 0)
 678                 return r;
 679
 680         return dmi.suspended ? 1 : 0;
 681 }
 682
 683 int dm_status_verity_ok(const char *name)
 684 {
 685         int r;
 686         struct dm_info dmi;
 687         char *status_line = NULL;
 688
 689         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 690         if (r < 0 || !status_line) {
 691                 free(status_line);
 692                 return r;
 693         }
 694
 695         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 696         r = status_line[0] == 'V' ? 1 : 0;
 697         free(status_line);
 698
 699         return r;
 700 }
 701
 702 /* FIXME use hex wrapper, user val wrappers for line parsing */
 703 static int _dm_query_crypt(uint32_t get_flags,
 704                            struct dm_info *dmi,
 705                            char *params,
 706                            struct crypt_dm_active_device *dmd)
 707 {
 708         uint64_t val64;
 709         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 710         unsigned int i;
 711
 712         memset(dmd, 0, sizeof(*dmd));
 713         dmd->target = DM_CRYPT;
 714
 715         rcipher = strsep(&params, " ");
 716         /* cipher */
 717         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 718                 dmd->u.crypt.cipher = strdup(rcipher);
 719
 720         /* skip */
 721         key_ = strsep(&params, " ");
 722         if (!params)
 723                 return -EINVAL;
 724         val64 = strtoull(params, &params, 10);
 725         if (*params != ' ')
 726                 return -EINVAL;
 727         params++;
 728
 729         dmd->u.crypt.iv_offset = val64;
 730
 731         /* device */
 732         rdevice = strsep(&params, " ");
 733         if (get_flags & DM_ACTIVE_DEVICE)
 734                 dmd->data_device = crypt_lookup_dev(rdevice);
 735
 736         /*offset */
 737         if (!params)
 738                 return -EINVAL;
 739         val64 = strtoull(params, &params, 10);
 740         dmd->u.crypt.offset = val64;
 741
 742         /* Features section, available since crypt target version 1.11 */
 743         if (*params) {
 744                 if (*params != ' ')
 745                         return -EINVAL;
 746                 params++;
 747
 748                 /* Number of arguments */
 749                 val64 = strtoull(params, &params, 10);
 750                 if (*params != ' ')
 751                         return -EINVAL;
 752                 params++;
 753
 754                 for (i = 0; i < val64; i++) {
 755                         if (!params)
 756                                 return -EINVAL;
 757                         arg = strsep(&params, " ");
 758                         if (!strcasecmp(arg, "allow_discards"))
 759                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 760                         else /* unknown option */
 761                                 return -EINVAL;
 762                 }
 763
 764                 /* All parameters shold be processed */
 765                 if (params)
 766                         return -EINVAL;
 767         }
 768
 769         /* Never allow to return empty key */
 770         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 771                 log_dbg("Cannot read volume key while suspended.");
 772                 return -EINVAL;
 773         }
 774
 775         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 776                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 777                 if (!dmd->u.crypt.vk)
 778                         return -ENOMEM;
 779
 780                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 781                         buffer[2] = '\0';
 782                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 783                                 memcpy(buffer, &key_[i * 2], 2);
 784                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 785                                 if (endp != &buffer[2]) {
 786                                         crypt_free_volume_key(dmd->u.crypt.vk);
 787                                         dmd->u.crypt.vk = NULL;
 788                                         return -EINVAL;
 789                                 }
 790                         }
 791                 }
 792         }
 793         memset(key_, 0, strlen(key_));
 794
 795         return 0;
 796 }
 797
 798 static int _dm_query_verity(uint32_t get_flags,
 799                              struct dm_info *dmi,
 800                              char *params,
 801                              struct crypt_dm_active_device *dmd)
 802 {
 803         struct crypt_params_verity *vp = NULL;
 804         uint32_t val32;
 805         uint64_t val64;
 806         ssize_t len;
 807         char *str, *str2;
 808
 809         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 810                 vp = dmd->u.verity.vp;
 811
 812         memset(dmd, 0, sizeof(*dmd));
 813
 814         dmd->target = DM_VERITY;
 815         dmd->u.verity.vp = vp;
 816
 817         /* version */
 818         val32 = strtoul(params, &params, 10);
 819         if (*params != ' ')
 820                 return -EINVAL;
 821         if (vp)
 822                 vp->hash_type = val32;
 823         params++;
 824
 825         /* data device */
 826         str = strsep(&params, " ");
 827         if (!params)
 828                 return -EINVAL;
 829         if (get_flags & DM_ACTIVE_DEVICE)
 830                 dmd->data_device = crypt_lookup_dev(str);
 831
 832         /* hash device */
 833         str = strsep(&params, " ");
 834         if (!params)
 835                 return -EINVAL;
 836         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE)
 837                 dmd->u.verity.hash_device = crypt_lookup_dev(str);
 838
 839         /* data block size*/
 840         val32 = strtoul(params, &params, 10);
 841         if (*params != ' ')
 842                 return -EINVAL;
 843         if (vp)
 844                 vp->data_block_size = val32;
 845         params++;
 846
 847         /* hash block size */
 848         val32 = strtoul(params, &params, 10);
 849         if (*params != ' ')
 850                 return -EINVAL;
 851         if (vp)
 852                 vp->hash_block_size = val32;
 853         params++;
 854
 855         /* data blocks */
 856         val64 = strtoull(params, &params, 10);
 857         if (*params != ' ')
 858                 return -EINVAL;
 859         if (vp)
 860                 vp->data_size = val64;
 861         params++;
 862
 863         /* hash start */
 864         val64 = strtoull(params, &params, 10);
 865         if (*params != ' ')
 866                 return -EINVAL;
 867         dmd->u.verity.hash_offset = val64;
 868         params++;
 869
 870         /* hash algorithm */
 871         str = strsep(&params, " ");
 872         if (!params)
 873                 return -EINVAL;
 874         if (vp)
 875                 vp->hash_name = strdup(str);
 876
 877         /* root digest */
 878         str = strsep(&params, " ");
 879         if (!params)
 880                 return -EINVAL;
 881         len = crypt_hex_to_bytes(str, &str2, 0);
 882         if (len < 0)
 883                 return len;
 884         dmd->u.verity.root_hash_size = len;
 885         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH)
 886                 dmd->u.verity.root_hash = str2;
 887         else
 888                 free(str2);
 889
 890         /* salt */
 891         str = strsep(&params, " ");
 892         if (params)
 893                 return -EINVAL;
 894         if (vp) {
 895                 if (!strcmp(str, "-")) {
 896                         vp->salt_size = 0;
 897                         vp->salt = NULL;
 898                 } else {
 899                         len = crypt_hex_to_bytes(str, &str2, 0);
 900                         if (len < 0)
 901                                 return len;
 902                         vp->salt_size = len;
 903                         vp->salt = str2;
 904                 }
 905         }
 906
 907         return 0;
 908 }
 909
 910 int dm_query_device(const char *name, uint32_t get_flags,
 911                     struct crypt_dm_active_device *dmd)
 912 {
 913         struct dm_task *dmt;
 914         struct dm_info dmi;
 915         uint64_t start, length;
 916         char *target_type, *params;
 917         const char *tmp_uuid;
 918         void *next = NULL;
 919         int r = -EINVAL;
 920
 921         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 922                 goto out;
 923         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 924                 goto out;
 925         if (!dm_task_set_name(dmt, name))
 926                 goto out;
 927         r = -ENODEV;
 928         if (!dm_task_run(dmt))
 929                 goto out;
 930
 931         r = -EINVAL;
 932         if (!dm_task_get_info(dmt, &dmi))
 933                 goto out;
 934
 935         if (!dmi.exists) {
 936                 r = -ENODEV;
 937                 goto out;
 938         }
 939
 940         next = dm_get_next_target(dmt, next, &start, &length,
 941                                   &target_type, &params);
 942
 943         if (!target_type || start != 0 || next)
 944                 goto out;
 945
 946         if (!strcmp(target_type, DM_CRYPT_TARGET)) {
 947                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
 948         } else if (!strcmp(target_type, DM_VERITY_TARGET)) {
 949                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
 950                 if (r < 0)
 951                         goto out;
 952                 r = dm_status_verity_ok(name);
 953                 if (r < 0)
 954                         goto out;
 955                 if (r == 0)
 956                         dmd->flags |= CRYPT_ACTIVATE_CORRUPTED;
 957                 r = 0;
 958         } else
 959                 r = -EINVAL;
 960
 961         if (r < 0)
 962                 goto out;
 963
 964         dmd->size = length;
 965
 966         if (dmi.read_only)
 967                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 968
 969         tmp_uuid = dm_task_get_uuid(dmt);
 970         if (!tmp_uuid)
 971                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 972         else if (get_flags & DM_ACTIVE_UUID) {
 973                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 974                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 975         }
 976
 977         r = (dmi.open_count > 0);
 978 out:
 979         if (dmt)
 980                 dm_task_destroy(dmt);
 981
 982         return r;
 983 }
 984
 985 static int _dm_message(const char *name, const char *msg)
 986 {
 987         int r = 0;
 988         struct dm_task *dmt;
 989
 990         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 991                 return 0;
 992
 993         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 994                 goto out;
 995
 996         if (name && !dm_task_set_name(dmt, name))
 997                 goto out;
 998
 999         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1000                 goto out;
1001
1002         if (!dm_task_set_message(dmt, msg))
1003                 goto out;
1004
1005         r = dm_task_run(dmt);
1006
1007       out:
1008         dm_task_destroy(dmt);
1009         return r;
1010 }
1011
1012 int dm_suspend_and_wipe_key(const char *name)
1013 {
1014         if (!_dm_check_versions())
1015                 return -ENOTSUP;
1016
1017         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1018                 return -ENOTSUP;
1019
1020         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
1021                 return -EINVAL;
1022
1023         if (!_dm_message(name, "key wipe")) {
1024                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1025                 return -EINVAL;
1026         }
1027
1028         return 0;
1029 }
1030
1031 int dm_resume_and_reinstate_key(const char *name,
1032                                 size_t key_size,
1033                                 const char *key)
1034 {
1035         int msg_size = key_size * 2 + 10; // key set <key>
1036         char *msg;
1037         int r = 0;
1038
1039         if (!_dm_check_versions())
1040                 return -ENOTSUP;
1041
1042         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1043                 return -ENOTSUP;
1044
1045         msg = crypt_safe_alloc(msg_size);
1046         if (!msg)
1047                 return -ENOMEM;
1048
1049         memset(msg, 0, msg_size);
1050         strcpy(msg, "key set ");
1051         hex_key(&msg[8], key_size, key);
1052
1053         if (!_dm_message(name, msg) ||
1054             !_dm_simple(DM_DEVICE_RESUME, name, 1))
1055                 r = -EINVAL;
1056
1057         crypt_safe_free(msg);
1058         return r;
1059 }
1060
1061 const char *dm_get_dir(void)
1062 {
1063         return dm_dir();
1064 }
1065
1066 int dm_is_dm_device(int major, int minor)
1067 {
1068         return dm_is_dm_major((uint32_t)major);
1069 }
1070
1071 int dm_is_dm_kernel_name(const char *name)
1072 {
1073         return strncmp(name, "dm-", 3) ? 0 : 1;
1074 }
1075
1076 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
1077 {
1078         struct crypt_dm_active_device dmd;
1079         int r;
1080
1081         log_dbg("Checking segments for device %s.", name);
1082
1083         r = dm_query_device(name, 0, &dmd);
1084         if (r < 0)
1085                 return r;
1086
1087         if (offset >= (dmd.u.crypt.offset + dmd.size) ||
1088            (offset + size) <= dmd.u.crypt.offset)
1089                 r = 0;
1090         else
1091                 r = -EBUSY;
1092
1093         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
1094                dmd.u.crypt.offset, dmd.u.crypt.offset + dmd.size, offset, offset + size,
1095                r ? " (overlapping)" : " (ok)");
1096
1097         return r;
1098 }