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 int 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) {
 504                 if (uuid_parse(uuid, uu) < 0) {
 505                         log_dbg("Requested UUID %s has invalid format.", uuid);
 506                         return -EINVAL;
 507                 }
 508
 509                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 510                         if (uuid[i] != '-') {
 511                                 *ptr = uuid[i];
 512                                 ptr++;
 513                         }
 514         }
 515
 516         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 517                 type ?: "", type ? "-" : "",
 518                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 519                 name);
 520
 521         log_dbg("DM-UUID is %s", buf);
 522         if (i >= buflen)
 523                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 524
 525         return 0;
 526 }
 527
 528 static int _dm_create_device(const char *name, const char *type,
 529                              struct device *device, uint32_t flags,
 530                              const char *uuid, uint64_t size,
 531                              char *params, int reload)
 532 {
 533         struct dm_task *dmt = NULL;
 534         struct dm_info dmi;
 535         char dev_uuid[DM_UUID_LEN] = {0};
 536         int r = -EINVAL;
 537         uint32_t read_ahead = 0;
 538         uint32_t cookie = 0;
 539         uint16_t udev_flags = 0;
 540
 541         if (flags & CRYPT_ACTIVATE_PRIVATE)
 542                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 543
 544         /* All devices must have DM_UUID, only resize on old device is exception */
 545         if (reload) {
 546                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 547                         goto out_no_removal;
 548
 549                 if (!dm_task_set_name(dmt, name))
 550                         goto out_no_removal;
 551         } else {
 552                 r = dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 553                 if (r < 0)
 554                         return r;
 555
 556                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 557                         goto out_no_removal;
 558
 559                 if (!dm_task_set_name(dmt, name))
 560                         goto out_no_removal;
 561
 562                 if (!dm_task_set_uuid(dmt, dev_uuid))
 563                         goto out_no_removal;
 564
 565                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 566                         goto out_no_removal;
 567         }
 568
 569         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 570                 goto out_no_removal;
 571         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 572                 goto out_no_removal;
 573
 574         if (!dm_task_add_target(dmt, 0, size,
 575                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 576                 goto out_no_removal;
 577
 578 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 579         if (device_read_ahead(device, &read_ahead) &&
 580             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 581                 goto out_no_removal;
 582 #endif
 583
 584         if (!dm_task_run(dmt))
 585                 goto out_no_removal;
 586
 587         if (reload) {
 588                 dm_task_destroy(dmt);
 589                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 590                         goto out;
 591                 if (!dm_task_set_name(dmt, name))
 592                         goto out;
 593                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 594                         goto out;
 595                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 596                         goto out;
 597                 if (!dm_task_run(dmt))
 598                         goto out;
 599         }
 600
 601         if (!dm_task_get_info(dmt, &dmi))
 602                 goto out;
 603
 604         r = 0;
 605 out:
 606         if (_dm_use_udev()) {
 607                 (void)_dm_udev_wait(cookie);
 608                 cookie = 0;
 609         }
 610
 611         if (r < 0 && !reload)
 612                 _dm_simple(DM_DEVICE_REMOVE, name, 1);
 613
 614 out_no_removal:
 615         if (cookie && _dm_use_udev())
 616                 (void)_dm_udev_wait(cookie);
 617
 618         if (params)
 619                 crypt_safe_free(params);
 620         if (dmt)
 621                 dm_task_destroy(dmt);
 622
 623         dm_task_update_nodes();
 624         return r;
 625 }
 626
 627 int dm_create_device(struct crypt_device *cd, const char *name,
 628                      const char *type,
 629                      struct crypt_dm_active_device *dmd,
 630                      int reload)
 631 {
 632         char *table_params = NULL;
 633         int r = -EINVAL;
 634
 635         if (!type)
 636                 return -EINVAL;
 637
 638         if (dm_init_context(cd))
 639                 return -ENOTSUP;
 640
 641         if (dmd->target == DM_CRYPT)
 642                 table_params = get_dm_crypt_params(dmd);
 643         else if (dmd->target == DM_VERITY)
 644                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 645
 646         if (table_params)
 647                 r = _dm_create_device(name, type, dmd->data_device,
 648                                       dmd->flags, dmd->uuid, dmd->size,
 649                                       table_params, reload);
 650         dm_exit_context();
 651         return r;
 652 }
 653
 654 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 655                           const char *target, char **status_line)
 656 {
 657         struct dm_task *dmt;
 658         uint64_t start, length;
 659         char *target_type, *params = NULL;
 660         void *next = NULL;
 661         int r = -EINVAL;
 662
 663         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 664                 goto out;
 665
 666         if (!dm_task_set_name(dmt, name))
 667                 goto out;
 668
 669         if (!dm_task_run(dmt))
 670                 goto out;
 671
 672         if (!dm_task_get_info(dmt, dmi))
 673                 goto out;
 674
 675         if (!dmi->exists) {
 676                 r = -ENODEV;
 677                 goto out;
 678         }
 679
 680         next = dm_get_next_target(dmt, next, &start, &length,
 681                                   &target_type, &params);
 682
 683         if (!target_type || start != 0 || next)
 684                 goto out;
 685
 686         if (target && strcmp(target_type, target))
 687                 goto out;
 688
 689         /* for target == NULL check all supported */
 690         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 691                         strcmp(target_type, DM_VERITY_TARGET)))
 692                 goto out;
 693         r = 0;
 694 out:
 695         if (!r && status_line && !(*status_line = strdup(params)))
 696                 r = -ENOMEM;
 697
 698         if (dmt)
 699                 dm_task_destroy(dmt);
 700
 701         return r;
 702 }
 703
 704 int dm_status_device(struct crypt_device *cd, const char *name)
 705 {
 706         int r;
 707         struct dm_info dmi;
 708         struct stat st;
 709
 710         /* libdevmapper is too clever and handles
 711          * path argument differenly with error.
 712          * Fail early here if parameter is non-existent path.
 713          */
 714         if (strchr(name, '/') && stat(name, &st) < 0)
 715                 return -ENODEV;
 716
 717         if (dm_init_context(cd))
 718                 return -ENOTSUP;
 719         r = dm_status_dmi(name, &dmi, NULL, NULL);
 720         dm_exit_context();
 721         if (r < 0)
 722                 return r;
 723
 724         return (dmi.open_count > 0);
 725 }
 726
 727 int dm_status_suspended(struct crypt_device *cd, const char *name)
 728 {
 729         int r;
 730         struct dm_info dmi;
 731
 732         if (dm_init_context(cd))
 733                 return -ENOTSUP;
 734         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 735         dm_exit_context();
 736         if (r < 0)
 737                 return r;
 738
 739         return dmi.suspended ? 1 : 0;
 740 }
 741
 742 static int _dm_status_verity_ok(const char *name)
 743 {
 744         int r;
 745         struct dm_info dmi;
 746         char *status_line = NULL;
 747
 748         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 749         if (r < 0 || !status_line) {
 750                 free(status_line);
 751                 return r;
 752         }
 753
 754         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 755         r = status_line[0] == 'V' ? 1 : 0;
 756         free(status_line);
 757
 758         return r;
 759 }
 760
 761 int dm_status_verity_ok(struct crypt_device *cd, const char *name)
 762 {
 763         int r;
 764
 765         if (dm_init_context(cd))
 766                 return -ENOTSUP;
 767         r = _dm_status_verity_ok(name);
 768         dm_exit_context();
 769         return r;
 770 }
 771
 772 /* FIXME use hex wrapper, user val wrappers for line parsing */
 773 static int _dm_query_crypt(uint32_t get_flags,
 774                            struct dm_info *dmi,
 775                            char *params,
 776                            struct crypt_dm_active_device *dmd)
 777 {
 778         uint64_t val64;
 779         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 780         unsigned int i;
 781         int r;
 782
 783         memset(dmd, 0, sizeof(*dmd));
 784         dmd->target = DM_CRYPT;
 785
 786         rcipher = strsep(&params, " ");
 787         /* cipher */
 788         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 789                 dmd->u.crypt.cipher = strdup(rcipher);
 790
 791         /* skip */
 792         key_ = strsep(&params, " ");
 793         if (!params)
 794                 return -EINVAL;
 795         val64 = strtoull(params, &params, 10);
 796         if (*params != ' ')
 797                 return -EINVAL;
 798         params++;
 799
 800         dmd->u.crypt.iv_offset = val64;
 801
 802         /* device */
 803         rdevice = strsep(&params, " ");
 804         if (get_flags & DM_ACTIVE_DEVICE) {
 805                 arg = crypt_lookup_dev(rdevice);
 806                 r = device_alloc(&dmd->data_device, arg);
 807                 free(arg);
 808                 if (r < 0 && r != -ENOTBLK)
 809                         return r;
 810         }
 811
 812         /*offset */
 813         if (!params)
 814                 return -EINVAL;
 815         val64 = strtoull(params, &params, 10);
 816         dmd->u.crypt.offset = val64;
 817
 818         /* Features section, available since crypt target version 1.11 */
 819         if (*params) {
 820                 if (*params != ' ')
 821                         return -EINVAL;
 822                 params++;
 823
 824                 /* Number of arguments */
 825                 val64 = strtoull(params, &params, 10);
 826                 if (*params != ' ')
 827                         return -EINVAL;
 828                 params++;
 829
 830                 for (i = 0; i < val64; i++) {
 831                         if (!params)
 832                                 return -EINVAL;
 833                         arg = strsep(&params, " ");
 834                         if (!strcasecmp(arg, "allow_discards"))
 835                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 836                         else /* unknown option */
 837                                 return -EINVAL;
 838                 }
 839
 840                 /* All parameters shold be processed */
 841                 if (params)
 842                         return -EINVAL;
 843         }
 844
 845         /* Never allow to return empty key */
 846         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 847                 log_dbg("Cannot read volume key while suspended.");
 848                 return -EINVAL;
 849         }
 850
 851         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 852                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 853                 if (!dmd->u.crypt.vk)
 854                         return -ENOMEM;
 855
 856                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 857                         buffer[2] = '\0';
 858                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 859                                 memcpy(buffer, &key_[i * 2], 2);
 860                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 861                                 if (endp != &buffer[2]) {
 862                                         crypt_free_volume_key(dmd->u.crypt.vk);
 863                                         dmd->u.crypt.vk = NULL;
 864                                         return -EINVAL;
 865                                 }
 866                         }
 867                 }
 868         }
 869         memset(key_, 0, strlen(key_));
 870
 871         return 0;
 872 }
 873
 874 static int _dm_query_verity(uint32_t get_flags,
 875                              struct dm_info *dmi,
 876                              char *params,
 877                              struct crypt_dm_active_device *dmd)
 878 {
 879         struct crypt_params_verity *vp = NULL;
 880         uint32_t val32;
 881         uint64_t val64;
 882         ssize_t len;
 883         char *str, *str2;
 884         int r;
 885
 886         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 887                 vp = dmd->u.verity.vp;
 888
 889         memset(dmd, 0, sizeof(*dmd));
 890
 891         dmd->target = DM_VERITY;
 892         dmd->u.verity.vp = vp;
 893
 894         /* version */
 895         val32 = strtoul(params, &params, 10);
 896         if (*params != ' ')
 897                 return -EINVAL;
 898         if (vp)
 899                 vp->hash_type = val32;
 900         params++;
 901
 902         /* data device */
 903         str = strsep(&params, " ");
 904         if (!params)
 905                 return -EINVAL;
 906         if (get_flags & DM_ACTIVE_DEVICE) {
 907                 str2 = crypt_lookup_dev(str);
 908                 r = device_alloc(&dmd->data_device, str2);
 909                 free(str2);
 910                 if (r < 0 && r != -ENOTBLK)
 911                         return r;
 912         }
 913
 914         /* hash device */
 915         str = strsep(&params, " ");
 916         if (!params)
 917                 return -EINVAL;
 918         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE) {
 919                 str2 = crypt_lookup_dev(str);
 920                 r = device_alloc(&dmd->u.verity.hash_device, str2);
 921                 free(str2);
 922                 if (r < 0 && r != -ENOTBLK)
 923                         return r;
 924         }
 925
 926         /* data block size*/
 927         val32 = strtoul(params, &params, 10);
 928         if (*params != ' ')
 929                 return -EINVAL;
 930         if (vp)
 931                 vp->data_block_size = val32;
 932         params++;
 933
 934         /* hash block size */
 935         val32 = strtoul(params, &params, 10);
 936         if (*params != ' ')
 937                 return -EINVAL;
 938         if (vp)
 939                 vp->hash_block_size = val32;
 940         params++;
 941
 942         /* data blocks */
 943         val64 = strtoull(params, &params, 10);
 944         if (*params != ' ')
 945                 return -EINVAL;
 946         if (vp)
 947                 vp->data_size = val64;
 948         params++;
 949
 950         /* hash start */
 951         val64 = strtoull(params, &params, 10);
 952         if (*params != ' ')
 953                 return -EINVAL;
 954         dmd->u.verity.hash_offset = val64;
 955         params++;
 956
 957         /* hash algorithm */
 958         str = strsep(&params, " ");
 959         if (!params)
 960                 return -EINVAL;
 961         if (vp)
 962                 vp->hash_name = strdup(str);
 963
 964         /* root digest */
 965         str = strsep(&params, " ");
 966         if (!params)
 967                 return -EINVAL;
 968         len = crypt_hex_to_bytes(str, &str2, 0);
 969         if (len < 0)
 970                 return len;
 971         dmd->u.verity.root_hash_size = len;
 972         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH)
 973                 dmd->u.verity.root_hash = str2;
 974         else
 975                 free(str2);
 976
 977         /* salt */
 978         str = strsep(&params, " ");
 979         if (params)
 980                 return -EINVAL;
 981         if (vp) {
 982                 if (!strcmp(str, "-")) {
 983                         vp->salt_size = 0;
 984                         vp->salt = NULL;
 985                 } else {
 986                         len = crypt_hex_to_bytes(str, &str2, 0);
 987                         if (len < 0)
 988                                 return len;
 989                         vp->salt_size = len;
 990                         vp->salt = str2;
 991                 }
 992         }
 993
 994         return 0;
 995 }
 996
 997 int dm_query_device(struct crypt_device *cd, const char *name,
 998                     uint32_t get_flags, struct crypt_dm_active_device *dmd)
 999 {
1000         struct dm_task *dmt;
1001         struct dm_info dmi;
1002         uint64_t start, length;
1003         char *target_type, *params;
1004         const char *tmp_uuid;
1005         void *next = NULL;
1006         int r = -EINVAL;
1007
1008         if (dm_init_context(cd))
1009                 return -ENOTSUP;
1010         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
1011                 goto out;
1012         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
1013                 goto out;
1014         if (!dm_task_set_name(dmt, name))
1015                 goto out;
1016         r = -ENODEV;
1017         if (!dm_task_run(dmt))
1018                 goto out;
1019
1020         r = -EINVAL;
1021         if (!dm_task_get_info(dmt, &dmi))
1022                 goto out;
1023
1024         if (!dmi.exists) {
1025                 r = -ENODEV;
1026                 goto out;
1027         }
1028
1029         next = dm_get_next_target(dmt, next, &start, &length,
1030                                   &target_type, &params);
1031
1032         if (!target_type || start != 0 || next)
1033                 goto out;
1034
1035         if (!strcmp(target_type, DM_CRYPT_TARGET)) {
1036                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
1037         } else if (!strcmp(target_type, DM_VERITY_TARGET)) {
1038                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
1039                 if (r < 0)
1040                         goto out;
1041                 r = _dm_status_verity_ok(name);
1042                 if (r < 0)
1043                         goto out;
1044                 if (r == 0)
1045                         dmd->flags |= CRYPT_ACTIVATE_CORRUPTED;
1046                 r = 0;
1047         } else
1048                 r = -EINVAL;
1049
1050         if (r < 0)
1051                 goto out;
1052
1053         dmd->size = length;
1054
1055         if (dmi.read_only)
1056                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
1057
1058         tmp_uuid = dm_task_get_uuid(dmt);
1059         if (!tmp_uuid)
1060                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
1061         else if (get_flags & DM_ACTIVE_UUID) {
1062                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
1063                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
1064         }
1065
1066         r = (dmi.open_count > 0);
1067 out:
1068         if (dmt)
1069                 dm_task_destroy(dmt);
1070
1071         dm_exit_context();
1072         return r;
1073 }
1074
1075 static int _dm_message(const char *name, const char *msg)
1076 {
1077         int r = 0;
1078         struct dm_task *dmt;
1079
1080         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
1081                 return 0;
1082
1083         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
1084                 goto out;
1085
1086         if (name && !dm_task_set_name(dmt, name))
1087                 goto out;
1088
1089         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1090                 goto out;
1091
1092         if (!dm_task_set_message(dmt, msg))
1093                 goto out;
1094
1095         r = dm_task_run(dmt);
1096
1097       out:
1098         dm_task_destroy(dmt);
1099         return r;
1100 }
1101
1102 int dm_suspend_and_wipe_key(struct crypt_device *cd, const char *name)
1103 {
1104         int r = -ENOTSUP;
1105
1106         if (dm_init_context(cd))
1107                 return -ENOTSUP;
1108
1109         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1110                 goto out;
1111
1112         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0)) {
1113                 r = -EINVAL;
1114                 goto out;
1115         }
1116
1117         if (!_dm_message(name, "key wipe")) {
1118                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1119                 r = -EINVAL;
1120                 goto out;
1121         }
1122         r = 0;
1123 out:
1124         dm_exit_context();
1125         return r;
1126 }
1127
1128 int dm_resume_and_reinstate_key(struct crypt_device *cd, const char *name,
1129                                 size_t key_size, const char *key)
1130 {
1131         int msg_size = key_size * 2 + 10; // key set <key>
1132         char *msg = NULL;
1133         int r = -ENOTSUP;
1134
1135         if (dm_init_context(cd))
1136                 return -ENOTSUP;
1137
1138         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1139                 goto out;
1140
1141         msg = crypt_safe_alloc(msg_size);
1142         if (!msg) {
1143                 r = -ENOMEM;
1144                 goto out;
1145         }
1146
1147         strcpy(msg, "key set ");
1148         hex_key(&msg[8], key_size, key);
1149
1150         if (!_dm_message(name, msg) ||
1151             !_dm_simple(DM_DEVICE_RESUME, name, 1)) {
1152                 r = -EINVAL;
1153                 goto out;
1154         }
1155         r = 0;
1156 out:
1157         crypt_safe_free(msg);
1158         dm_exit_context();
1159         return r;
1160 }
1161
1162 const char *dm_get_dir(void)
1163 {
1164         return dm_dir();
1165 }
1166
1167 int dm_is_dm_device(int major, int minor)
1168 {
1169         return dm_is_dm_major((uint32_t)major);
1170 }
1171
1172 int dm_is_dm_kernel_name(const char *name)
1173 {
1174         return strncmp(name, "dm-", 3) ? 0 : 1;
1175 }