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 int hex_to_bytes(const char *hex, char *result)
 260 {
 261         char buf[3] = "xx\0", *endp;
 262         int i, len;
 263
 264         len = strlen(hex) / 2;
 265         for (i = 0; i < len; i++) {
 266                 memcpy(buf, &hex[i * 2], 2);
 267                 result[i] = strtoul(buf, &endp, 16);
 268                 if (endp != &buf[2])
 269                         return -EINVAL;
 270         }
 271         return i;
 272 }
 273
 274 /* http://code.google.com/p/cryptsetup/wiki/DMCrypt */
 275 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 276 {
 277         int r, max_size, null_cipher = 0;
 278         char *params, *hexkey;
 279         const char *features = "";
 280
 281         if (!dmd)
 282                 return NULL;
 283
 284         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 285                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 286                         features = " 1 allow_discards";
 287                         log_dbg("Discard/TRIM is allowed.");
 288                 } else
 289                         log_dbg("Discard/TRIM is not supported by the kernel.");
 290         }
 291
 292         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 293                 null_cipher = 1;
 294
 295         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 296         if (!hexkey)
 297                 return NULL;
 298
 299         if (null_cipher)
 300                 strncpy(hexkey, "-", 2);
 301         else
 302                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 303
 304         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 305                    strlen(dmd->data_device) + strlen(features) + 64;
 306         params = crypt_safe_alloc(max_size);
 307         if (!params)
 308                 goto out;
 309
 310         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 311                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 312                      dmd->data_device, dmd->u.crypt.offset, features);
 313         if (r < 0 || r >= max_size) {
 314                 crypt_safe_free(params);
 315                 params = NULL;
 316         }
 317 out:
 318         crypt_safe_free(hexkey);
 319         return params;
 320 }
 321
 322 /* http://code.google.com/p/cryptsetup/wiki/DMVerity */
 323 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 324                                    struct crypt_dm_active_device *dmd)
 325 {
 326         int max_size, r;
 327         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 328
 329         if (!vp || !dmd)
 330                 return NULL;
 331
 332         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 333         if (!hexroot)
 334                 goto out;
 335         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 336
 337         hexsalt = crypt_safe_alloc(vp->salt_size ? vp->salt_size * 2 + 1 : 2);
 338         if (!hexsalt)
 339                 goto out;
 340         if (vp->salt_size)
 341                 hex_key(hexsalt, vp->salt_size, vp->salt);
 342         else
 343                 strncpy(hexsalt, "-", 2);
 344
 345         max_size = strlen(hexroot) + strlen(hexsalt) +
 346                    strlen(dmd->data_device) +
 347                    strlen(dmd->u.verity.hash_device) +
 348                    strlen(vp->hash_name) + 128;
 349
 350         params = crypt_safe_alloc(max_size);
 351         if (!params)
 352                 goto out;
 353
 354         r = snprintf(params, max_size,
 355                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 356                      vp->version, dmd->data_device,
 357                      dmd->u.verity.hash_device,
 358                      vp->data_block_size, vp->hash_block_size,
 359                      vp->data_size, dmd->u.verity.hash_offset,
 360                      vp->hash_name, hexroot, hexsalt);
 361         if (r < 0 || r >= max_size) {
 362                 crypt_safe_free(params);
 363                 params = NULL;
 364         }
 365         log_dbg("TABLE: %s", params);
 366 out:
 367         crypt_safe_free(hexroot);
 368         crypt_safe_free(hexsalt);
 369         return params;
 370
 371 }
 372
 373 /* DM helpers */
 374 static int _dm_simple(int task, const char *name, int udev_wait)
 375 {
 376         int r = 0;
 377         struct dm_task *dmt;
 378         uint32_t cookie = 0;
 379
 380         if (!_dm_use_udev())
 381                 udev_wait = 0;
 382
 383         if (!(dmt = dm_task_create(task)))
 384                 return 0;
 385
 386         if (name && !dm_task_set_name(dmt, name))
 387                 goto out;
 388
 389 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 390         /* Used only in DM_DEVICE_REMOVE */
 391         if (name && !dm_task_retry_remove(dmt))
 392                 goto out;
 393 #endif
 394         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 395                 goto out;
 396
 397         r = dm_task_run(dmt);
 398
 399         if (udev_wait)
 400                 (void)_dm_udev_wait(cookie);
 401
 402       out:
 403         dm_task_destroy(dmt);
 404         return r;
 405 }
 406
 407 static int _error_device(const char *name, size_t size)
 408 {
 409         struct dm_task *dmt;
 410         int r = 0;
 411
 412         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 413                 return 0;
 414
 415         if (!dm_task_set_name(dmt, name))
 416                 goto error;
 417
 418         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 419                 goto error;
 420
 421         if (!dm_task_set_ro(dmt))
 422                 goto error;
 423
 424         if (!dm_task_no_open_count(dmt))
 425                 goto error;
 426
 427         if (!dm_task_run(dmt))
 428                 goto error;
 429
 430         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 431                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 432                 goto error;
 433         }
 434
 435         r = 1;
 436
 437 error:
 438         dm_task_destroy(dmt);
 439         return r;
 440 }
 441
 442 int dm_remove_device(const char *name, int force, uint64_t size)
 443 {
 444         int r = -EINVAL;
 445         int retries = force ? RETRY_COUNT : 1;
 446         int error_target = 0;
 447
 448         if (!name || (force && !size))
 449                 return -EINVAL;
 450
 451         do {
 452                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 453                 if (--retries && r) {
 454                         log_dbg("WARNING: other process locked internal device %s, %s.",
 455                                 name, retries ? "retrying remove" : "giving up");
 456                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 457                                 debug_processes_using_device(name);
 458                         sleep(1);
 459                         if (force && !error_target) {
 460                                 /* If force flag is set, replace device with error, read-only target.
 461                                  * it should stop processes from reading it and also removed underlying
 462                                  * device from mapping, so it is usable again.
 463                                  * Force flag should be used only for temporary devices, which are
 464                                  * intended to work inside cryptsetup only!
 465                                  * Anyway, if some process try to read temporary cryptsetup device,
 466                                  * it is bug - no other process should try touch it (e.g. udev).
 467                                  */
 468                                 _error_device(name, size);
 469                                 error_target = 1;
 470                         }
 471                 }
 472         } while (r == -EINVAL && retries);
 473
 474         dm_task_update_nodes();
 475
 476         return r;
 477 }
 478
 479 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 480 /*
 481  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 482  * CRYPT-PLAIN-name
 483  * CRYPT-LUKS1-00000000000000000000000000000000-name
 484  * CRYPT-TEMP-name
 485  */
 486 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 487 {
 488         char *ptr, uuid2[UUID_LEN] = {0};
 489         uuid_t uu;
 490         unsigned i = 0;
 491
 492         /* Remove '-' chars */
 493         if (uuid && !uuid_parse(uuid, uu)) {
 494                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 495                         if (uuid[i] != '-') {
 496                                 *ptr = uuid[i];
 497                                 ptr++;
 498                         }
 499         }
 500
 501         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 502                 type ?: "", type ? "-" : "",
 503                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 504                 name);
 505
 506         log_dbg("DM-UUID is %s", buf);
 507         if (i >= buflen)
 508                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 509 }
 510
 511 static int _dm_create_device(const char *name, const char *type,
 512                              const char *device, uint32_t flags,
 513                              const char *uuid, uint64_t size,
 514                              char *params, int reload)
 515 {
 516         struct dm_task *dmt = NULL;
 517         struct dm_info dmi;
 518         char dev_uuid[DM_UUID_LEN] = {0};
 519         int r = -EINVAL;
 520         uint32_t read_ahead = 0;
 521         uint32_t cookie = 0;
 522         uint16_t udev_flags = 0;
 523
 524         if (flags & CRYPT_ACTIVATE_PRIVATE)
 525                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 526
 527         /* All devices must have DM_UUID, only resize on old device is exception */
 528         if (reload) {
 529                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 530                         goto out_no_removal;
 531
 532                 if (!dm_task_set_name(dmt, name))
 533                         goto out_no_removal;
 534         } else {
 535                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 536
 537                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 538                         goto out_no_removal;
 539
 540                 if (!dm_task_set_name(dmt, name))
 541                         goto out_no_removal;
 542
 543                 if (!dm_task_set_uuid(dmt, dev_uuid))
 544                         goto out_no_removal;
 545
 546                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 547                         goto out_no_removal;
 548         }
 549
 550         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 551                 goto out_no_removal;
 552         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 553                 goto out_no_removal;
 554
 555         if (!dm_task_add_target(dmt, 0, size,
 556                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 557                 goto out_no_removal;
 558
 559 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 560         if (device_read_ahead(device, &read_ahead) &&
 561             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 562                 goto out_no_removal;
 563 #endif
 564
 565         if (!dm_task_run(dmt))
 566                 goto out_no_removal;
 567
 568         if (reload) {
 569                 dm_task_destroy(dmt);
 570                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 571                         goto out;
 572                 if (!dm_task_set_name(dmt, name))
 573                         goto out;
 574                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 575                         goto out;
 576                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 577                         goto out;
 578                 if (!dm_task_run(dmt))
 579                         goto out;
 580         }
 581
 582         if (!dm_task_get_info(dmt, &dmi))
 583                 goto out;
 584
 585         r = 0;
 586 out:
 587         if (_dm_use_udev()) {
 588                 (void)_dm_udev_wait(cookie);
 589                 cookie = 0;
 590         }
 591
 592         if (r < 0 && !reload)
 593                 dm_remove_device(name, 0, 0);
 594
 595 out_no_removal:
 596         if (cookie && _dm_use_udev())
 597                 (void)_dm_udev_wait(cookie);
 598
 599         if (params)
 600                 crypt_safe_free(params);
 601         if (dmt)
 602                 dm_task_destroy(dmt);
 603
 604         dm_task_update_nodes();
 605         return r;
 606 }
 607
 608 int dm_create_device(const char *name,
 609                      const char *type,
 610                      struct crypt_dm_active_device *dmd,
 611                      int reload)
 612 {
 613         char *table_params = NULL;
 614
 615         if (dmd->target == DM_CRYPT)
 616                 table_params = get_dm_crypt_params(dmd);
 617         else if (dmd->target == DM_VERITY)
 618                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 619
 620         if (!table_params)
 621                 return -EINVAL;
 622
 623         return _dm_create_device(name, type, dmd->data_device, dmd->flags,
 624                                  dmd->uuid, dmd->size, table_params, reload);
 625 }
 626
 627 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 628                           const char *target, char **status_line)
 629 {
 630         struct dm_task *dmt;
 631         uint64_t start, length;
 632         char *target_type, *params = NULL;
 633         void *next = NULL;
 634         int r = -EINVAL;
 635
 636         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 637                 goto out;
 638
 639         if (!dm_task_set_name(dmt, name))
 640                 goto out;
 641
 642         if (!dm_task_run(dmt))
 643                 goto out;
 644
 645         if (!dm_task_get_info(dmt, dmi))
 646                 goto out;
 647
 648         if (!dmi->exists) {
 649                 r = -ENODEV;
 650                 goto out;
 651         }
 652
 653         next = dm_get_next_target(dmt, next, &start, &length,
 654                                   &target_type, &params);
 655
 656         if (!target_type || start != 0 || next)
 657                 goto out;
 658
 659         if (target && strcmp(target_type, target))
 660                 goto out;
 661
 662         /* for target == NULL check all supported */
 663         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 664                         strcmp(target_type, DM_VERITY_TARGET)))
 665                 goto out;
 666         r = 0;
 667 out:
 668         if (!r && status_line && !(*status_line = strdup(params)))
 669                 r = -ENOMEM;
 670
 671         if (dmt)
 672                 dm_task_destroy(dmt);
 673
 674         return r;
 675 }
 676
 677 int dm_status_device(const char *name)
 678 {
 679         int r;
 680         struct dm_info dmi;
 681
 682         r = dm_status_dmi(name, &dmi, NULL, NULL);
 683         if (r < 0)
 684                 return r;
 685
 686         return (dmi.open_count > 0);
 687 }
 688
 689 int dm_status_suspended(const char *name)
 690 {
 691         int r;
 692         struct dm_info dmi;
 693
 694         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 695         if (r < 0)
 696                 return r;
 697
 698         return dmi.suspended ? 1 : 0;
 699 }
 700
 701 int dm_status_verity_ok(const char *name)
 702 {
 703         int r;
 704         struct dm_info dmi;
 705         char *status_line = NULL;
 706
 707         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 708         if (r < 0 || !status_line) {
 709                 free(status_line);
 710                 return r;
 711         }
 712
 713         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 714         r = status_line[0] == 'V' ? 1 : 0;
 715         free(status_line);
 716
 717         return r;
 718 }
 719
 720 /* FIXME use hex wrapper, user val wrappers for line parsing */
 721 static int _dm_query_crypt(uint32_t get_flags,
 722                            struct dm_info *dmi,
 723                            char *params,
 724                            struct crypt_dm_active_device *dmd)
 725 {
 726         uint64_t val64;
 727         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 728         unsigned int i;
 729
 730         memset(dmd, 0, sizeof(*dmd));
 731         dmd->target = DM_CRYPT;
 732
 733         rcipher = strsep(&params, " ");
 734         /* cipher */
 735         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 736                 dmd->u.crypt.cipher = strdup(rcipher);
 737
 738         /* skip */
 739         key_ = strsep(&params, " ");
 740         if (!params)
 741                 return -EINVAL;
 742         val64 = strtoull(params, &params, 10);
 743         if (*params != ' ')
 744                 return -EINVAL;
 745         params++;
 746
 747         dmd->u.crypt.iv_offset = val64;
 748
 749         /* device */
 750         rdevice = strsep(&params, " ");
 751         if (get_flags & DM_ACTIVE_DEVICE)
 752                 dmd->data_device = crypt_lookup_dev(rdevice);
 753
 754         /*offset */
 755         if (!params)
 756                 return -EINVAL;
 757         val64 = strtoull(params, &params, 10);
 758         dmd->u.crypt.offset = val64;
 759
 760         /* Features section, available since crypt target version 1.11 */
 761         if (*params) {
 762                 if (*params != ' ')
 763                         return -EINVAL;
 764                 params++;
 765
 766                 /* Number of arguments */
 767                 val64 = strtoull(params, &params, 10);
 768                 if (*params != ' ')
 769                         return -EINVAL;
 770                 params++;
 771
 772                 for (i = 0; i < val64; i++) {
 773                         if (!params)
 774                                 return -EINVAL;
 775                         arg = strsep(&params, " ");
 776                         if (!strcasecmp(arg, "allow_discards"))
 777                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 778                         else /* unknown option */
 779                                 return -EINVAL;
 780                 }
 781
 782                 /* All parameters shold be processed */
 783                 if (params)
 784                         return -EINVAL;
 785         }
 786
 787         /* Never allow to return empty key */
 788         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 789                 log_dbg("Cannot read volume key while suspended.");
 790                 return -EINVAL;
 791         }
 792
 793         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 794                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 795                 if (!dmd->u.crypt.vk)
 796                         return -ENOMEM;
 797
 798                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 799                         buffer[2] = '\0';
 800                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 801                                 memcpy(buffer, &key_[i * 2], 2);
 802                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 803                                 if (endp != &buffer[2]) {
 804                                         crypt_free_volume_key(dmd->u.crypt.vk);
 805                                         dmd->u.crypt.vk = NULL;
 806                                         return -EINVAL;
 807                                 }
 808                         }
 809                 }
 810         }
 811         memset(key_, 0, strlen(key_));
 812
 813         return 0;
 814 }
 815
 816 static int _dm_query_verity(uint32_t get_flags,
 817                              struct dm_info *dmi,
 818                              char *params,
 819                              struct crypt_dm_active_device *dmd)
 820 {
 821         struct crypt_params_verity *vp = NULL;
 822         uint32_t val32;
 823         uint64_t val64;
 824         size_t len;
 825         char *str, *str2;
 826
 827         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 828                 vp = dmd->u.verity.vp;
 829
 830         memset(dmd, 0, sizeof(*dmd));
 831
 832         dmd->target = DM_VERITY;
 833         dmd->u.verity.vp = vp;
 834
 835         /* version */
 836         val32 = strtoul(params, &params, 10);
 837         if (*params != ' ')
 838                 return -EINVAL;
 839         if (vp)
 840                 vp->version = val32;
 841         params++;
 842
 843         /* data device */
 844         str = strsep(&params, " ");
 845         if (!params)
 846                 return -EINVAL;
 847         if (get_flags & DM_ACTIVE_DEVICE)
 848                 dmd->data_device = crypt_lookup_dev(str);
 849
 850         /* hash device */
 851         str = strsep(&params, " ");
 852         if (!params)
 853                 return -EINVAL;
 854         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE)
 855                 dmd->u.verity.hash_device = crypt_lookup_dev(str);
 856
 857         /* data block size*/
 858         val32 = strtoul(params, &params, 10);
 859         if (*params != ' ')
 860                 return -EINVAL;
 861         if (vp)
 862                 vp->data_block_size = val32;
 863         params++;
 864
 865         /* hash block size */
 866         val32 = strtoul(params, &params, 10);
 867         if (*params != ' ')
 868                 return -EINVAL;
 869         if (vp)
 870                 vp->hash_block_size = val32;
 871         params++;
 872
 873         /* data blocks */
 874         val64 = strtoull(params, &params, 10);
 875         if (*params != ' ')
 876                 return -EINVAL;
 877         if (vp)
 878                 vp->data_size = val64;
 879         params++;
 880
 881         /* hash start */
 882         val64 = strtoull(params, &params, 10);
 883         if (*params != ' ')
 884                 return -EINVAL;
 885         dmd->u.verity.hash_offset = val64;
 886         params++;
 887
 888         /* hash algorithm */
 889         str = strsep(&params, " ");
 890         if (!params)
 891                 return -EINVAL;
 892         if (vp)
 893                 vp->hash_name = strdup(str);
 894
 895         /* root digest */
 896         str = strsep(&params, " ");
 897         if (!params)
 898                 return -EINVAL;
 899         len = strlen(str) / 2;
 900         dmd->u.verity.root_hash_size = len;
 901         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH) {
 902                 if (!(str2 = malloc(len)))
 903                         return -ENOMEM;
 904                 if (hex_to_bytes(str, str2) != len)
 905                         return -EINVAL;
 906                 dmd->u.verity.root_hash = str2;
 907         }
 908
 909         /* salt */
 910         str = strsep(&params, " ");
 911         if (params)
 912                 return -EINVAL;
 913         if (vp) {
 914                 len = strlen(str) / 2;
 915                 vp->salt_size = len;
 916                 if (!(str2 = malloc(len)))
 917                         return -ENOMEM;
 918                 if (hex_to_bytes(str, str2) != len)
 919                         return -EINVAL;
 920                 vp->salt = str2;
 921         }
 922
 923         return 0;
 924 }
 925
 926 int dm_query_device(const char *name, uint32_t get_flags,
 927                     struct crypt_dm_active_device *dmd)
 928 {
 929         struct dm_task *dmt;
 930         struct dm_info dmi;
 931         uint64_t start, length;
 932         char *target_type, *params;
 933         const char *tmp_uuid;
 934         void *next = NULL;
 935         int r = -EINVAL;
 936
 937         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 938                 goto out;
 939         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 940                 goto out;
 941         if (!dm_task_set_name(dmt, name))
 942                 goto out;
 943         r = -ENODEV;
 944         if (!dm_task_run(dmt))
 945                 goto out;
 946
 947         r = -EINVAL;
 948         if (!dm_task_get_info(dmt, &dmi))
 949                 goto out;
 950
 951         if (!dmi.exists) {
 952                 r = -ENODEV;
 953                 goto out;
 954         }
 955
 956         next = dm_get_next_target(dmt, next, &start, &length,
 957                                   &target_type, &params);
 958
 959         if (!target_type || start != 0 || next)
 960                 goto out;
 961
 962         if (!strcmp(target_type, DM_CRYPT_TARGET))
 963                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
 964         else if (!strcmp(target_type, DM_VERITY_TARGET))
 965                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
 966         else
 967                 r = -EINVAL;
 968
 969         if (r < 0)
 970                 goto out;
 971
 972         dmd->size = length;
 973
 974         if (dmi.read_only)
 975                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 976
 977         tmp_uuid = dm_task_get_uuid(dmt);
 978         if (!tmp_uuid)
 979                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 980         else if (get_flags & DM_ACTIVE_UUID) {
 981                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 982                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 983         }
 984
 985         r = (dmi.open_count > 0);
 986 out:
 987         if (dmt)
 988                 dm_task_destroy(dmt);
 989
 990         return r;
 991 }
 992
 993 static int _dm_message(const char *name, const char *msg)
 994 {
 995         int r = 0;
 996         struct dm_task *dmt;
 997
 998         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 999                 return 0;
1000
1001         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
1002                 goto out;
1003
1004         if (name && !dm_task_set_name(dmt, name))
1005                 goto out;
1006
1007         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1008                 goto out;
1009
1010         if (!dm_task_set_message(dmt, msg))
1011                 goto out;
1012
1013         r = dm_task_run(dmt);
1014
1015       out:
1016         dm_task_destroy(dmt);
1017         return r;
1018 }
1019
1020 int dm_suspend_and_wipe_key(const char *name)
1021 {
1022         if (!_dm_check_versions())
1023                 return -ENOTSUP;
1024
1025         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1026                 return -ENOTSUP;
1027
1028         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
1029                 return -EINVAL;
1030
1031         if (!_dm_message(name, "key wipe")) {
1032                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1033                 return -EINVAL;
1034         }
1035
1036         return 0;
1037 }
1038
1039 int dm_resume_and_reinstate_key(const char *name,
1040                                 size_t key_size,
1041                                 const char *key)
1042 {
1043         int msg_size = key_size * 2 + 10; // key set <key>
1044         char *msg;
1045         int r = 0;
1046
1047         if (!_dm_check_versions())
1048                 return -ENOTSUP;
1049
1050         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1051                 return -ENOTSUP;
1052
1053         msg = crypt_safe_alloc(msg_size);
1054         if (!msg)
1055                 return -ENOMEM;
1056
1057         memset(msg, 0, msg_size);
1058         strcpy(msg, "key set ");
1059         hex_key(&msg[8], key_size, key);
1060
1061         if (!_dm_message(name, msg) ||
1062             !_dm_simple(DM_DEVICE_RESUME, name, 1))
1063                 r = -EINVAL;
1064
1065         crypt_safe_free(msg);
1066         return r;
1067 }
1068
1069 const char *dm_get_dir(void)
1070 {
1071         return dm_dir();
1072 }
1073
1074 int dm_is_dm_device(int major, int minor)
1075 {
1076         return dm_is_dm_major((uint32_t)major);
1077 }
1078
1079 int dm_is_dm_kernel_name(const char *name)
1080 {
1081         return strncmp(name, "dm-", 3) ? 0 : 1;
1082 }
1083
1084 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
1085 {
1086         struct crypt_dm_active_device dmd;
1087         int r;
1088
1089         log_dbg("Checking segments for device %s.", name);
1090
1091         r = dm_query_device(name, 0, &dmd);
1092         if (r < 0)
1093                 return r;
1094
1095         if (offset >= (dmd.u.crypt.offset + dmd.size) ||
1096            (offset + size) <= dmd.u.crypt.offset)
1097                 r = 0;
1098         else
1099                 r = -EBUSY;
1100
1101         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
1102                dmd.u.crypt.offset, dmd.u.crypt.offset + dmd.size, offset, offset + size,
1103                r ? " (overlapping)" : " (ok)");
1104
1105         return r;
1106 }