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  * Copyright (C) 2009-2012, Milan Broz
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  */
  23
  24 #include <stdio.h>
  25 #include <dirent.h>
  26 #include <errno.h>
  27 #include <libdevmapper.h>
  28 #include <fcntl.h>
  29 #include <linux/fs.h>
  30 #include <uuid/uuid.h>
  31
  32 #include "internal.h"
  33
  34 #define DM_UUID_LEN             129
  35 #define DM_UUID_PREFIX          "CRYPT-"
  36 #define DM_UUID_PREFIX_LEN      6
  37 #define DM_CRYPT_TARGET         "crypt"
  38 #define DM_VERITY_TARGET        "verity"
  39 #define RETRY_COUNT             5
  40
  41 /* Set if dm-crypt version was probed */
  42 static int _dm_crypt_checked = 0;
  43 static int _quiet_log = 0;
  44 static uint32_t _dm_crypt_flags = 0;
  45
  46 static struct crypt_device *_context = NULL;
  47 static int _dm_use_count = 0;
  48
  49 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  50 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  51 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  52 #endif
  53
  54 /* Compatibility for old device-mapper without udev support */
  55 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  56 #define CRYPT_TEMP_UDEV_FLAGS   DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
  57                                 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
  58                                 DM_UDEV_DISABLE_OTHER_RULES_FLAG
  59 #define _dm_task_set_cookie     dm_task_set_cookie
  60 #define _dm_udev_wait           dm_udev_wait
  61 #else
  62 #define CRYPT_TEMP_UDEV_FLAGS   0
  63 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  64 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  65 #endif
  66
  67 static int _dm_use_udev(void)
  68 {
  69 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  70         return dm_udev_get_sync_support();
  71 #else
  72         return 0;
  73 #endif
  74 }
  75
  76 __attribute__((format(printf, 4, 5)))
  77 static void set_dm_error(int level,
  78                          const char *file __attribute__((unused)),
  79                          int line __attribute__((unused)),
  80                          const char *f, ...)
  81 {
  82         char *msg = NULL;
  83         va_list va;
  84
  85         va_start(va, f);
  86         if (vasprintf(&msg, f, va) > 0) {
  87                 if (level < 4 && !_quiet_log) {
  88                         log_err(_context, msg);
  89                         log_err(_context, "\n");
  90                 } else {
  91                         /* We do not use DM visual stack backtrace here */
  92                         if (strncmp(msg, "<backtrace>", 11))
  93                                 log_dbg(msg);
  94                 }
  95         }
  96         free(msg);
  97         va_end(va);
  98 }
  99
 100 static int _dm_simple(int task, const char *name, int udev_wait);
 101
 102 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
 103                                  unsigned crypt_min, unsigned crypt_patch)
 104 {
 105         unsigned dm_maj, dm_min, dm_patch;
 106
 107         if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
 108                 dm_maj = dm_min = dm_patch = 0;
 109
 110         log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
 111                 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
 112
 113         if (crypt_maj >= 1 && crypt_min >= 2)
 114                 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
 115         else
 116                 log_dbg("Suspend and resume disabled, no wipe key support.");
 117
 118         if (crypt_maj >= 1 && crypt_min >= 10)
 119                 _dm_crypt_flags |= DM_LMK_SUPPORTED;
 120
 121         if (dm_maj >= 4 && dm_min >= 20)
 122                 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
 123
 124         /* not perfect, 2.6.33 supports with 1.7.0 */
 125         if (crypt_maj >= 1 && crypt_min >= 8)
 126                 _dm_crypt_flags |= DM_PLAIN64_SUPPORTED;
 127
 128         if (crypt_maj >= 1 && crypt_min >= 11)
 129                 _dm_crypt_flags |= DM_DISCARDS_SUPPORTED;
 130
 131         /* Repeat test if dm-crypt is not present */
 132         if (crypt_maj > 0)
 133                 _dm_crypt_checked = 1;
 134 }
 135
 136 static void _dm_set_verity_compat(const char *dm_version, unsigned verity_maj,
 137                                    unsigned verity_min, unsigned verity_patch)
 138 {
 139         if (verity_maj > 0)
 140                 _dm_crypt_flags |= DM_VERITY_SUPPORTED;
 141
 142         log_dbg("Detected dm-verity version %i.%i.%i.",
 143                 verity_maj, verity_min, verity_patch);
 144 }
 145
 146 static int _dm_check_versions(void)
 147 {
 148         struct dm_task *dmt;
 149         struct dm_versions *target, *last_target;
 150         char dm_version[16];
 151         int r = 0;
 152
 153         if (_dm_crypt_checked)
 154                 return 1;
 155
 156         /* Shut up DM while checking */
 157         _quiet_log = 1;
 158
 159         /* FIXME: add support to DM so it forces crypt target module load here */
 160         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 161                 goto out;
 162
 163         if (!dm_task_run(dmt))
 164                 goto out;
 165
 166         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version)))
 167                 goto out;
 168
 169         target = dm_task_get_versions(dmt);
 170         do {
 171                 last_target = target;
 172                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 173                         _dm_set_crypt_compat(dm_version,
 174                                              (unsigned)target->version[0],
 175                                              (unsigned)target->version[1],
 176                                              (unsigned)target->version[2]);
 177                 } else if (!strcmp(DM_VERITY_TARGET, target->name)) {
 178                         _dm_set_verity_compat(dm_version,
 179                                              (unsigned)target->version[0],
 180                                              (unsigned)target->version[1],
 181                                              (unsigned)target->version[2]);
 182                 }
 183                 target = (struct dm_versions *)((char *) target + target->next);
 184         } while (last_target != target);
 185
 186         r = 1;
 187         log_dbg("Device-mapper backend running with UDEV support %sabled.",
 188                 _dm_use_udev() ? "en" : "dis");
 189 out:
 190         if (dmt)
 191                 dm_task_destroy(dmt);
 192
 193         _quiet_log = 0;
 194         return r;
 195 }
 196
 197 uint32_t dm_flags(void)
 198 {
 199         _dm_check_versions();
 200         return _dm_crypt_flags;
 201 }
 202
 203 /* This doesn't run any kernel checks, just set up userspace libdevmapper */
 204 void dm_backend_init(void)
 205 {
 206         if (!_dm_use_count++) {
 207                 log_dbg("Initialising device-mapper backend library.");
 208                 dm_log_init(set_dm_error);
 209                 dm_log_init_verbose(10);
 210         }
 211 }
 212
 213 void dm_backend_exit(void)
 214 {
 215         if (_dm_use_count && (!--_dm_use_count)) {
 216                 log_dbg("Releasing device-mapper backend.");
 217                 dm_log_init_verbose(0);
 218                 dm_log_init(NULL);
 219                 dm_lib_release();
 220         }
 221 }
 222
 223 /*
 224  * libdevmapper is not context friendly, switch context on every DM call.
 225  * FIXME: this is not safe if called in parallel but neither is DM lib.
 226  */
 227 static int dm_init_context(struct crypt_device *cd)
 228 {
 229         _context = cd;
 230         if (!_dm_check_versions()) {
 231                 if (getuid() || geteuid())
 232                         log_err(cd, _("Cannot initialize device-mapper, "
 233                                       "running as non-root user.\n"));
 234                 else
 235                         log_err(cd, _("Cannot initialize device-mapper. "
 236                                       "Is dm_mod kernel module loaded?\n"));
 237                 _context = NULL;
 238                 return -ENOTSUP;
 239         }
 240         return 0;
 241 }
 242 static void dm_exit_context(void)
 243 {
 244         _context = NULL;
 245 }
 246
 247 /* Return path to DM device */
 248 char *dm_device_path(const char *prefix, int major, int minor)
 249 {
 250         struct dm_task *dmt;
 251         const char *name;
 252         char path[PATH_MAX];
 253
 254         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 255                 return NULL;
 256         if (!dm_task_set_minor(dmt, minor) ||
 257             !dm_task_set_major(dmt, major) ||
 258             !dm_task_run(dmt) ||
 259             !(name = dm_task_get_name(dmt))) {
 260                 dm_task_destroy(dmt);
 261                 return NULL;
 262         }
 263
 264         if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
 265                 path[0] = '\0';
 266
 267         dm_task_destroy(dmt);
 268
 269         return strdup(path);
 270 }
 271
 272 static void hex_key(char *hexkey, size_t key_size, const char *key)
 273 {
 274         unsigned i;
 275
 276         for(i = 0; i < key_size; i++)
 277                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 278 }
 279
 280 /* http://code.google.com/p/cryptsetup/wiki/DMCrypt */
 281 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 282 {
 283         int r, max_size, null_cipher = 0;
 284         char *params, *hexkey;
 285         const char *features = "";
 286
 287         if (!dmd)
 288                 return NULL;
 289
 290         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 291                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 292                         features = " 1 allow_discards";
 293                         log_dbg("Discard/TRIM is allowed.");
 294                 } else
 295                         log_dbg("Discard/TRIM is not supported by the kernel.");
 296         }
 297
 298         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 299                 null_cipher = 1;
 300
 301         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 302         if (!hexkey)
 303                 return NULL;
 304
 305         if (null_cipher)
 306                 strncpy(hexkey, "-", 2);
 307         else
 308                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 309
 310         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 311                    strlen(device_block_path(dmd->data_device)) +
 312                    strlen(features) + 64;
 313         params = crypt_safe_alloc(max_size);
 314         if (!params)
 315                 goto out;
 316
 317         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 318                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 319                      device_block_path(dmd->data_device), dmd->u.crypt.offset,
 320                      features);
 321         if (r < 0 || r >= max_size) {
 322                 crypt_safe_free(params);
 323                 params = NULL;
 324         }
 325 out:
 326         crypt_safe_free(hexkey);
 327         return params;
 328 }
 329
 330 /* http://code.google.com/p/cryptsetup/wiki/DMVerity */
 331 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 332                                    struct crypt_dm_active_device *dmd)
 333 {
 334         int max_size, r;
 335         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 336
 337         if (!vp || !dmd)
 338                 return NULL;
 339
 340         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 341         if (!hexroot)
 342                 goto out;
 343         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 344
 345         hexsalt = crypt_safe_alloc(vp->salt_size ? vp->salt_size * 2 + 1 : 2);
 346         if (!hexsalt)
 347                 goto out;
 348         if (vp->salt_size)
 349                 hex_key(hexsalt, vp->salt_size, vp->salt);
 350         else
 351                 strncpy(hexsalt, "-", 2);
 352
 353         max_size = strlen(hexroot) + strlen(hexsalt) +
 354                    strlen(device_block_path(dmd->data_device)) +
 355                    strlen(device_block_path(dmd->u.verity.hash_device)) +
 356                    strlen(vp->hash_name) + 128;
 357
 358         params = crypt_safe_alloc(max_size);
 359         if (!params)
 360                 goto out;
 361
 362         r = snprintf(params, max_size,
 363                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 364                      vp->hash_type, device_block_path(dmd->data_device),
 365                      device_block_path(dmd->u.verity.hash_device),
 366                      vp->data_block_size, vp->hash_block_size,
 367                      vp->data_size, dmd->u.verity.hash_offset,
 368                      vp->hash_name, hexroot, hexsalt);
 369         if (r < 0 || r >= max_size) {
 370                 crypt_safe_free(params);
 371                 params = NULL;
 372         }
 373 out:
 374         crypt_safe_free(hexroot);
 375         crypt_safe_free(hexsalt);
 376         return params;
 377
 378 }
 379
 380 /* DM helpers */
 381 static int _dm_simple(int task, const char *name, int udev_wait)
 382 {
 383         int r = 0;
 384         struct dm_task *dmt;
 385         uint32_t cookie = 0;
 386
 387         if (!_dm_use_udev())
 388                 udev_wait = 0;
 389
 390         if (!(dmt = dm_task_create(task)))
 391                 return 0;
 392
 393         if (name && !dm_task_set_name(dmt, name))
 394                 goto out;
 395
 396 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 397         /* Used only in DM_DEVICE_REMOVE */
 398         if (name && !dm_task_retry_remove(dmt))
 399                 goto out;
 400 #endif
 401         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 402                 goto out;
 403
 404         r = dm_task_run(dmt);
 405
 406         if (udev_wait)
 407                 (void)_dm_udev_wait(cookie);
 408
 409       out:
 410         dm_task_destroy(dmt);
 411         return r;
 412 }
 413
 414 static int _error_device(const char *name, size_t size)
 415 {
 416         struct dm_task *dmt;
 417         int r = 0;
 418
 419         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 420                 return 0;
 421
 422         if (!dm_task_set_name(dmt, name))
 423                 goto error;
 424
 425         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 426                 goto error;
 427
 428         if (!dm_task_set_ro(dmt))
 429                 goto error;
 430
 431         if (!dm_task_no_open_count(dmt))
 432                 goto error;
 433
 434         if (!dm_task_run(dmt))
 435                 goto error;
 436
 437         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 438                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 439                 goto error;
 440         }
 441
 442         r = 1;
 443
 444 error:
 445         dm_task_destroy(dmt);
 446         return r;
 447 }
 448
 449 int dm_remove_device(struct crypt_device *cd, const char *name,
 450                      int force, uint64_t size)
 451 {
 452         int r = -EINVAL;
 453         int retries = force ? RETRY_COUNT : 1;
 454         int error_target = 0;
 455
 456         if (!name || (force && !size))
 457                 return -EINVAL;
 458
 459         if (dm_init_context(cd))
 460                 return -ENOTSUP;
 461
 462         do {
 463                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 464                 if (--retries && r) {
 465                         log_dbg("WARNING: other process locked internal device %s, %s.",
 466                                 name, retries ? "retrying remove" : "giving up");
 467                         sleep(1);
 468                         if (force && !error_target) {
 469                                 /* If force flag is set, replace device with error, read-only target.
 470                                  * it should stop processes from reading it and also removed underlying
 471                                  * device from mapping, so it is usable again.
 472                                  * Force flag should be used only for temporary devices, which are
 473                                  * intended to work inside cryptsetup only!
 474                                  * Anyway, if some process try to read temporary cryptsetup device,
 475                                  * it is bug - no other process should try touch it (e.g. udev).
 476                                  */
 477                                 _error_device(name, size);
 478                                 error_target = 1;
 479                         }
 480                 }
 481         } while (r == -EINVAL && retries);
 482
 483         dm_task_update_nodes();
 484         dm_exit_context();
 485
 486         return r;
 487 }
 488
 489 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 490 /*
 491  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 492  * CRYPT-PLAIN-name
 493  * CRYPT-LUKS1-00000000000000000000000000000000-name
 494  * CRYPT-TEMP-name
 495  */
 496 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 497 {
 498         char *ptr, uuid2[UUID_LEN] = {0};
 499         uuid_t uu;
 500         unsigned i = 0;
 501
 502         /* Remove '-' chars */
 503         if (uuid && !uuid_parse(uuid, uu)) {
 504                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 505                         if (uuid[i] != '-') {
 506                                 *ptr = uuid[i];
 507                                 ptr++;
 508                         }
 509         }
 510
 511         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 512                 type ?: "", type ? "-" : "",
 513                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 514                 name);
 515
 516         log_dbg("DM-UUID is %s", buf);
 517         if (i >= buflen)
 518                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 519 }
 520
 521 static int _dm_create_device(const char *name, const char *type,
 522                              struct device *device, uint32_t flags,
 523                              const char *uuid, uint64_t size,
 524                              char *params, int reload)
 525 {
 526         struct dm_task *dmt = NULL;
 527         struct dm_info dmi;
 528         char dev_uuid[DM_UUID_LEN] = {0};
 529         int r = -EINVAL;
 530         uint32_t read_ahead = 0;
 531         uint32_t cookie = 0;
 532         uint16_t udev_flags = 0;
 533
 534         if (flags & CRYPT_ACTIVATE_PRIVATE)
 535                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 536
 537         /* All devices must have DM_UUID, only resize on old device is exception */
 538         if (reload) {
 539                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 540                         goto out_no_removal;
 541
 542                 if (!dm_task_set_name(dmt, name))
 543                         goto out_no_removal;
 544         } else {
 545                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 546
 547                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 548                         goto out_no_removal;
 549
 550                 if (!dm_task_set_name(dmt, name))
 551                         goto out_no_removal;
 552
 553                 if (!dm_task_set_uuid(dmt, dev_uuid))
 554                         goto out_no_removal;
 555
 556                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 557                         goto out_no_removal;
 558         }
 559
 560         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 561                 goto out_no_removal;
 562         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 563                 goto out_no_removal;
 564
 565         if (!dm_task_add_target(dmt, 0, size,
 566                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 567                 goto out_no_removal;
 568
 569 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 570         if (device_read_ahead(device, &read_ahead) &&
 571             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 572                 goto out_no_removal;
 573 #endif
 574
 575         if (!dm_task_run(dmt))
 576                 goto out_no_removal;
 577
 578         if (reload) {
 579                 dm_task_destroy(dmt);
 580                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 581                         goto out;
 582                 if (!dm_task_set_name(dmt, name))
 583                         goto out;
 584                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 585                         goto out;
 586                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 587                         goto out;
 588                 if (!dm_task_run(dmt))
 589                         goto out;
 590         }
 591
 592         if (!dm_task_get_info(dmt, &dmi))
 593                 goto out;
 594
 595         r = 0;
 596 out:
 597         if (_dm_use_udev()) {
 598                 (void)_dm_udev_wait(cookie);
 599                 cookie = 0;
 600         }
 601
 602         if (r < 0 && !reload)
 603                 _dm_simple(DM_DEVICE_REMOVE, name, 1);
 604
 605 out_no_removal:
 606         if (cookie && _dm_use_udev())
 607                 (void)_dm_udev_wait(cookie);
 608
 609         if (params)
 610                 crypt_safe_free(params);
 611         if (dmt)
 612                 dm_task_destroy(dmt);
 613
 614         dm_task_update_nodes();
 615         return r;
 616 }
 617
 618 int dm_create_device(struct crypt_device *cd, const char *name,
 619                      const char *type,
 620                      struct crypt_dm_active_device *dmd,
 621                      int reload)
 622 {
 623         char *table_params = NULL;
 624         int r = -EINVAL;
 625
 626         if (!type)
 627                 return -EINVAL;
 628
 629         if (dm_init_context(cd))
 630                 return -ENOTSUP;
 631
 632         if (dmd->target == DM_CRYPT)
 633                 table_params = get_dm_crypt_params(dmd);
 634         else if (dmd->target == DM_VERITY)
 635                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 636
 637         if (table_params)
 638                 r = _dm_create_device(name, type, dmd->data_device,
 639                                       dmd->flags, dmd->uuid, dmd->size,
 640                                       table_params, reload);
 641         dm_exit_context();
 642         return r;
 643 }
 644
 645 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 646                           const char *target, char **status_line)
 647 {
 648         struct dm_task *dmt;
 649         uint64_t start, length;
 650         char *target_type, *params = NULL;
 651         void *next = NULL;
 652         int r = -EINVAL;
 653
 654         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 655                 goto out;
 656
 657         if (!dm_task_set_name(dmt, name))
 658                 goto out;
 659
 660         if (!dm_task_run(dmt))
 661                 goto out;
 662
 663         if (!dm_task_get_info(dmt, dmi))
 664                 goto out;
 665
 666         if (!dmi->exists) {
 667                 r = -ENODEV;
 668                 goto out;
 669         }
 670
 671         next = dm_get_next_target(dmt, next, &start, &length,
 672                                   &target_type, &params);
 673
 674         if (!target_type || start != 0 || next)
 675                 goto out;
 676
 677         if (target && strcmp(target_type, target))
 678                 goto out;
 679
 680         /* for target == NULL check all supported */
 681         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 682                         strcmp(target_type, DM_VERITY_TARGET)))
 683                 goto out;
 684         r = 0;
 685 out:
 686         if (!r && status_line && !(*status_line = strdup(params)))
 687                 r = -ENOMEM;
 688
 689         if (dmt)
 690                 dm_task_destroy(dmt);
 691
 692         return r;
 693 }
 694
 695 int dm_status_device(struct crypt_device *cd, const char *name)
 696 {
 697         int r;
 698         struct dm_info dmi;
 699         struct stat st;
 700
 701         /* libdevmapper is too clever and handles
 702          * path argument differenly with error.
 703          * Fail early here if parameter is non-existent path.
 704          */
 705         if (strchr(name, '/') && stat(name, &st) < 0)
 706                 return -ENODEV;
 707
 708         if (dm_init_context(cd))
 709                 return -ENOTSUP;
 710         r = dm_status_dmi(name, &dmi, NULL, NULL);
 711         dm_exit_context();
 712         if (r < 0)
 713                 return r;
 714
 715         return (dmi.open_count > 0);
 716 }
 717
 718 int dm_status_suspended(struct crypt_device *cd, const char *name)
 719 {
 720         int r;
 721         struct dm_info dmi;
 722
 723         if (dm_init_context(cd))
 724                 return -ENOTSUP;
 725         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 726         dm_exit_context();
 727         if (r < 0)
 728                 return r;
 729
 730         return dmi.suspended ? 1 : 0;
 731 }
 732
 733 static int _dm_status_verity_ok(const char *name)
 734 {
 735         int r;
 736         struct dm_info dmi;
 737         char *status_line = NULL;
 738
 739         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 740         if (r < 0 || !status_line) {
 741                 free(status_line);
 742                 return r;
 743         }
 744
 745         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 746         r = status_line[0] == 'V' ? 1 : 0;
 747         free(status_line);
 748
 749         return r;
 750 }
 751
 752 int dm_status_verity_ok(struct crypt_device *cd, const char *name)
 753 {
 754         int r;
 755
 756         if (dm_init_context(cd))
 757                 return -ENOTSUP;
 758         r = _dm_status_verity_ok(name);
 759         dm_exit_context();
 760         return r;
 761 }
 762
 763 /* FIXME use hex wrapper, user val wrappers for line parsing */
 764 static int _dm_query_crypt(uint32_t get_flags,
 765                            struct dm_info *dmi,
 766                            char *params,
 767                            struct crypt_dm_active_device *dmd)
 768 {
 769         uint64_t val64;
 770         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 771         unsigned int i;
 772         int r;
 773
 774         memset(dmd, 0, sizeof(*dmd));
 775         dmd->target = DM_CRYPT;
 776
 777         rcipher = strsep(&params, " ");
 778         /* cipher */
 779         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 780                 dmd->u.crypt.cipher = strdup(rcipher);
 781
 782         /* skip */
 783         key_ = strsep(&params, " ");
 784         if (!params)
 785                 return -EINVAL;
 786         val64 = strtoull(params, &params, 10);
 787         if (*params != ' ')
 788                 return -EINVAL;
 789         params++;
 790
 791         dmd->u.crypt.iv_offset = val64;
 792
 793         /* device */
 794         rdevice = strsep(&params, " ");
 795         if (get_flags & DM_ACTIVE_DEVICE) {
 796                 arg = crypt_lookup_dev(rdevice);
 797                 r = device_alloc(&dmd->data_device, arg);
 798                 free(arg);
 799                 if (r < 0 && r != -ENOTBLK)
 800                         return r;
 801         }
 802
 803         /*offset */
 804         if (!params)
 805                 return -EINVAL;
 806         val64 = strtoull(params, &params, 10);
 807         dmd->u.crypt.offset = val64;
 808
 809         /* Features section, available since crypt target version 1.11 */
 810         if (*params) {
 811                 if (*params != ' ')
 812                         return -EINVAL;
 813                 params++;
 814
 815                 /* Number of arguments */
 816                 val64 = strtoull(params, &params, 10);
 817                 if (*params != ' ')
 818                         return -EINVAL;
 819                 params++;
 820
 821                 for (i = 0; i < val64; i++) {
 822                         if (!params)
 823                                 return -EINVAL;
 824                         arg = strsep(&params, " ");
 825                         if (!strcasecmp(arg, "allow_discards"))
 826                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 827                         else /* unknown option */
 828                                 return -EINVAL;
 829                 }
 830
 831                 /* All parameters shold be processed */
 832                 if (params)
 833                         return -EINVAL;
 834         }
 835
 836         /* Never allow to return empty key */
 837         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 838                 log_dbg("Cannot read volume key while suspended.");
 839                 return -EINVAL;
 840         }
 841
 842         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 843                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 844                 if (!dmd->u.crypt.vk)
 845                         return -ENOMEM;
 846
 847                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 848                         buffer[2] = '\0';
 849                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 850                                 memcpy(buffer, &key_[i * 2], 2);
 851                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 852                                 if (endp != &buffer[2]) {
 853                                         crypt_free_volume_key(dmd->u.crypt.vk);
 854                                         dmd->u.crypt.vk = NULL;
 855                                         return -EINVAL;
 856                                 }
 857                         }
 858                 }
 859         }
 860         memset(key_, 0, strlen(key_));
 861
 862         return 0;
 863 }
 864
 865 static int _dm_query_verity(uint32_t get_flags,
 866                              struct dm_info *dmi,
 867                              char *params,
 868                              struct crypt_dm_active_device *dmd)
 869 {
 870         struct crypt_params_verity *vp = NULL;
 871         uint32_t val32;
 872         uint64_t val64;
 873         ssize_t len;
 874         char *str, *str2;
 875         int r;
 876
 877         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 878                 vp = dmd->u.verity.vp;
 879
 880         memset(dmd, 0, sizeof(*dmd));
 881
 882         dmd->target = DM_VERITY;
 883         dmd->u.verity.vp = vp;
 884
 885         /* version */
 886         val32 = strtoul(params, &params, 10);
 887         if (*params != ' ')
 888                 return -EINVAL;
 889         if (vp)
 890                 vp->hash_type = val32;
 891         params++;
 892
 893         /* data device */
 894         str = strsep(&params, " ");
 895         if (!params)
 896                 return -EINVAL;
 897         if (get_flags & DM_ACTIVE_DEVICE) {
 898                 str2 = crypt_lookup_dev(str);
 899                 r = device_alloc(&dmd->data_device, str2);
 900                 free(str2);
 901                 if (r < 0 && r != -ENOTBLK)
 902                         return r;
 903         }
 904
 905         /* hash device */
 906         str = strsep(&params, " ");
 907         if (!params)
 908                 return -EINVAL;
 909         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE) {
 910                 str2 = crypt_lookup_dev(str);
 911                 r = device_alloc(&dmd->u.verity.hash_device, str2);
 912                 free(str2);
 913                 if (r < 0 && r != -ENOTBLK)
 914                         return r;
 915         }
 916
 917         /* data block size*/
 918         val32 = strtoul(params, &params, 10);
 919         if (*params != ' ')
 920                 return -EINVAL;
 921         if (vp)
 922                 vp->data_block_size = val32;
 923         params++;
 924
 925         /* hash block size */
 926         val32 = strtoul(params, &params, 10);
 927         if (*params != ' ')
 928                 return -EINVAL;
 929         if (vp)
 930                 vp->hash_block_size = val32;
 931         params++;
 932
 933         /* data blocks */
 934         val64 = strtoull(params, &params, 10);
 935         if (*params != ' ')
 936                 return -EINVAL;
 937         if (vp)
 938                 vp->data_size = val64;
 939         params++;
 940
 941         /* hash start */
 942         val64 = strtoull(params, &params, 10);
 943         if (*params != ' ')
 944                 return -EINVAL;
 945         dmd->u.verity.hash_offset = val64;
 946         params++;
 947
 948         /* hash algorithm */
 949         str = strsep(&params, " ");
 950         if (!params)
 951                 return -EINVAL;
 952         if (vp)
 953                 vp->hash_name = strdup(str);
 954
 955         /* root digest */
 956         str = strsep(&params, " ");
 957         if (!params)
 958                 return -EINVAL;
 959         len = crypt_hex_to_bytes(str, &str2, 0);
 960         if (len < 0)
 961                 return len;
 962         dmd->u.verity.root_hash_size = len;
 963         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH)
 964                 dmd->u.verity.root_hash = str2;
 965         else
 966                 free(str2);
 967
 968         /* salt */
 969         str = strsep(&params, " ");
 970         if (params)
 971                 return -EINVAL;
 972         if (vp) {
 973                 if (!strcmp(str, "-")) {
 974                         vp->salt_size = 0;
 975                         vp->salt = NULL;
 976                 } else {
 977                         len = crypt_hex_to_bytes(str, &str2, 0);
 978                         if (len < 0)
 979                                 return len;
 980                         vp->salt_size = len;
 981                         vp->salt = str2;
 982                 }
 983         }
 984
 985         return 0;
 986 }
 987
 988 int dm_query_device(struct crypt_device *cd, const char *name,
 989                     uint32_t get_flags, struct crypt_dm_active_device *dmd)
 990 {
 991         struct dm_task *dmt;
 992         struct dm_info dmi;
 993         uint64_t start, length;
 994         char *target_type, *params;
 995         const char *tmp_uuid;
 996         void *next = NULL;
 997         int r = -EINVAL;
 998
 999         if (dm_init_context(cd))
1000                 return -ENOTSUP;
1001         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
1002                 goto out;
1003         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
1004                 goto out;
1005         if (!dm_task_set_name(dmt, name))
1006                 goto out;
1007         r = -ENODEV;
1008         if (!dm_task_run(dmt))
1009                 goto out;
1010
1011         r = -EINVAL;
1012         if (!dm_task_get_info(dmt, &dmi))
1013                 goto out;
1014
1015         if (!dmi.exists) {
1016                 r = -ENODEV;
1017                 goto out;
1018         }
1019
1020         next = dm_get_next_target(dmt, next, &start, &length,
1021                                   &target_type, &params);
1022
1023         if (!target_type || start != 0 || next)
1024                 goto out;
1025
1026         if (!strcmp(target_type, DM_CRYPT_TARGET)) {
1027                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
1028         } else if (!strcmp(target_type, DM_VERITY_TARGET)) {
1029                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
1030                 if (r < 0)
1031                         goto out;
1032                 r = _dm_status_verity_ok(name);
1033                 if (r < 0)
1034                         goto out;
1035                 if (r == 0)
1036                         dmd->flags |= CRYPT_ACTIVATE_CORRUPTED;
1037                 r = 0;
1038         } else
1039                 r = -EINVAL;
1040
1041         if (r < 0)
1042                 goto out;
1043
1044         dmd->size = length;
1045
1046         if (dmi.read_only)
1047                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
1048
1049         tmp_uuid = dm_task_get_uuid(dmt);
1050         if (!tmp_uuid)
1051                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
1052         else if (get_flags & DM_ACTIVE_UUID) {
1053                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
1054                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
1055         }
1056
1057         r = (dmi.open_count > 0);
1058 out:
1059         if (dmt)
1060                 dm_task_destroy(dmt);
1061
1062         dm_exit_context();
1063         return r;
1064 }
1065
1066 static int _dm_message(const char *name, const char *msg)
1067 {
1068         int r = 0;
1069         struct dm_task *dmt;
1070
1071         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
1072                 return 0;
1073
1074         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
1075                 goto out;
1076
1077         if (name && !dm_task_set_name(dmt, name))
1078                 goto out;
1079
1080         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1081                 goto out;
1082
1083         if (!dm_task_set_message(dmt, msg))
1084                 goto out;
1085
1086         r = dm_task_run(dmt);
1087
1088       out:
1089         dm_task_destroy(dmt);
1090         return r;
1091 }
1092
1093 int dm_suspend_and_wipe_key(struct crypt_device *cd, const char *name)
1094 {
1095         int r = -ENOTSUP;
1096
1097         if (dm_init_context(cd))
1098                 return -ENOTSUP;
1099
1100         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1101                 goto out;
1102
1103         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0)) {
1104                 r = -EINVAL;
1105                 goto out;
1106         }
1107
1108         if (!_dm_message(name, "key wipe")) {
1109                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1110                 r = -EINVAL;
1111                 goto out;
1112         }
1113         r = 0;
1114 out:
1115         dm_exit_context();
1116         return r;
1117 }
1118
1119 int dm_resume_and_reinstate_key(struct crypt_device *cd, const char *name,
1120                                 size_t key_size, const char *key)
1121 {
1122         int msg_size = key_size * 2 + 10; // key set <key>
1123         char *msg = NULL;
1124         int r = -ENOTSUP;
1125
1126         if (dm_init_context(cd))
1127                 return -ENOTSUP;
1128
1129         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1130                 goto out;
1131
1132         msg = crypt_safe_alloc(msg_size);
1133         if (!msg) {
1134                 r = -ENOMEM;
1135                 goto out;
1136         }
1137
1138         strcpy(msg, "key set ");
1139         hex_key(&msg[8], key_size, key);
1140
1141         if (!_dm_message(name, msg) ||
1142             !_dm_simple(DM_DEVICE_RESUME, name, 1)) {
1143                 r = -EINVAL;
1144                 goto out;
1145         }
1146         r = 0;
1147 out:
1148         crypt_safe_free(msg);
1149         dm_exit_context();
1150         return r;
1151 }
1152
1153 const char *dm_get_dir(void)
1154 {
1155         return dm_dir();
1156 }
1157
1158 int dm_is_dm_device(int major, int minor)
1159 {
1160         return dm_is_dm_major((uint32_t)major);
1161 }
1162
1163 int dm_is_dm_kernel_name(const char *name)
1164 {
1165         return strncmp(name, "dm-", 3) ? 0 : 1;
1166 }