lib/libdevmapper.c

   1 /*
   2  * libdevmapper - device-mapper backend for cryptsetup
   3  *
   4  * Copyright (C) 2004, Christophe Saout <christophe@saout.de>
   5  * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
   6  * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25 #include <libdevmapper.h>
  26 #include <fcntl.h>
  27 #include <linux/fs.h>
  28 #include <uuid/uuid.h>
  29
  30 #include "internal.h"
  31
  32 #define DM_UUID_LEN             129
  33 #define DM_UUID_PREFIX          "CRYPT-"
  34 #define DM_UUID_PREFIX_LEN      6
  35 #define DM_CRYPT_TARGET         "crypt"
  36 #define DM_VERITY_TARGET        "verity"
  37 #define RETRY_COUNT             5
  38
  39 /* Set if dm-crypt version was probed */
  40 static int _dm_crypt_checked = 0;
  41 static uint32_t _dm_crypt_flags = 0;
  42
  43 static int _dm_use_count = 0;
  44 static struct crypt_device *_context = NULL;
  45
  46 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  47 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  48 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  49 #endif
  50
  51 /* Compatibility for old device-mapper without udev support */
  52 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  53 #define CRYPT_TEMP_UDEV_FLAGS   DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
  54                                 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
  55                                 DM_UDEV_DISABLE_OTHER_RULES_FLAG
  56 #define _dm_task_set_cookie     dm_task_set_cookie
  57 #define _dm_udev_wait           dm_udev_wait
  58 #else
  59 #define CRYPT_TEMP_UDEV_FLAGS   0
  60 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  61 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  62 #endif
  63
  64 static int _dm_use_udev(void)
  65 {
  66 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  67         return dm_udev_get_sync_support();
  68 #else
  69         return 0;
  70 #endif
  71 }
  72
  73 __attribute__((format(printf, 4, 5)))
  74 static void set_dm_error(int level,
  75                          const char *file __attribute__((unused)),
  76                          int line __attribute__((unused)),
  77                          const char *f, ...)
  78 {
  79         char *msg = NULL;
  80         va_list va;
  81
  82         va_start(va, f);
  83         if (vasprintf(&msg, f, va) > 0) {
  84                 if (level < 4) {
  85                         log_err(_context, msg);
  86                         log_err(_context, "\n");
  87                 } else
  88                         log_dbg(msg);
  89         }
  90         free(msg);
  91         va_end(va);
  92 }
  93
  94 static int _dm_simple(int task, const char *name, int udev_wait);
  95
  96 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
  97                                  unsigned crypt_min, unsigned crypt_patch)
  98 {
  99         unsigned dm_maj, dm_min, dm_patch;
 100
 101         if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
 102                 dm_maj = dm_min = dm_patch = 0;
 103
 104         log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
 105                 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
 106
 107         if (crypt_maj >= 1 && crypt_min >= 2)
 108                 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
 109         else
 110                 log_dbg("Suspend and resume disabled, no wipe key support.");
 111
 112         if (crypt_maj >= 1 && crypt_min >= 10)
 113                 _dm_crypt_flags |= DM_LMK_SUPPORTED;
 114
 115         if (dm_maj >= 4 && dm_min >= 20)
 116                 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
 117
 118         /* not perfect, 2.6.33 supports with 1.7.0 */
 119         if (crypt_maj >= 1 && crypt_min >= 8)
 120                 _dm_crypt_flags |= DM_PLAIN64_SUPPORTED;
 121
 122         if (crypt_maj >= 1 && crypt_min >= 11)
 123                 _dm_crypt_flags |= DM_DISCARDS_SUPPORTED;
 124
 125         /* Repeat test if dm-crypt is not present */
 126         if (crypt_maj > 0)
 127                 _dm_crypt_checked = 1;
 128 }
 129
 130 static void _dm_set_verity_compat(const char *dm_version, unsigned verity_maj,
 131                                    unsigned verity_min, unsigned verity_patch)
 132 {
 133         if (verity_maj > 0)
 134                 _dm_crypt_flags |= DM_VERITY_SUPPORTED;
 135
 136         log_dbg("Detected dm-verity version %i.%i.%i.",
 137                 verity_maj, verity_min, verity_patch);
 138 }
 139
 140 static int _dm_check_versions(void)
 141 {
 142         struct dm_task *dmt;
 143         struct dm_versions *target, *last_target;
 144         char dm_version[16];
 145
 146         if (_dm_crypt_checked)
 147                 return 1;
 148
 149         /* FIXME: add support to DM so it forces crypt target module load here */
 150         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 151                 return 0;
 152
 153         if (!dm_task_run(dmt)) {
 154                 dm_task_destroy(dmt);
 155                 return 0;
 156         }
 157
 158         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 159                 dm_task_destroy(dmt);
 160                 return 0;
 161         }
 162
 163         target = dm_task_get_versions(dmt);
 164         do {
 165                 last_target = target;
 166                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 167                         _dm_set_crypt_compat(dm_version,
 168                                              (unsigned)target->version[0],
 169                                              (unsigned)target->version[1],
 170                                              (unsigned)target->version[2]);
 171                 } else if (!strcmp(DM_VERITY_TARGET, target->name)) {
 172                         _dm_set_verity_compat(dm_version,
 173                                              (unsigned)target->version[0],
 174                                              (unsigned)target->version[1],
 175                                              (unsigned)target->version[2]);
 176                 }
 177                 target = (struct dm_versions *)((char *) target + target->next);
 178         } while (last_target != target);
 179
 180         dm_task_destroy(dmt);
 181         return 1;
 182 }
 183
 184 uint32_t dm_flags(void)
 185 {
 186         if (!_dm_crypt_checked)
 187                 _dm_check_versions();
 188
 189         return _dm_crypt_flags;
 190 }
 191
 192 int dm_init(struct crypt_device *context, int check_kernel)
 193 {
 194         if (!_dm_use_count++) {
 195                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 196                         check_kernel ? "" : " (NO kernel check requested)",
 197                         _dm_use_udev() ? "en" : "dis");
 198                 if (check_kernel && !_dm_check_versions()) {
 199                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 200                         return -1;
 201                 }
 202                 if (getuid() || geteuid())
 203                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 204                 dm_log_init(set_dm_error);
 205                 dm_log_init_verbose(10);
 206         }
 207
 208         // FIXME: global context is not safe
 209         if (context)
 210                 _context = context;
 211
 212         return 1;       /* unsafe memory */
 213 }
 214
 215 void dm_exit(void)
 216 {
 217         if (_dm_use_count && (!--_dm_use_count)) {
 218                 log_dbg("Releasing device-mapper backend.");
 219                 dm_log_init_verbose(0);
 220                 dm_log_init(NULL);
 221                 dm_lib_release();
 222                 _context = NULL;
 223         }
 224 }
 225
 226 /* Return path to DM device */
 227 char *dm_device_path(const char *prefix, int major, int minor)
 228 {
 229         struct dm_task *dmt;
 230         const char *name;
 231         char path[PATH_MAX];
 232
 233         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 234                 return NULL;
 235         if (!dm_task_set_minor(dmt, minor) ||
 236             !dm_task_set_major(dmt, major) ||
 237             !dm_task_run(dmt) ||
 238             !(name = dm_task_get_name(dmt))) {
 239                 dm_task_destroy(dmt);
 240                 return NULL;
 241         }
 242
 243         if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
 244                 path[0] = '\0';
 245
 246         dm_task_destroy(dmt);
 247
 248         return strdup(path);
 249 }
 250
 251 static void hex_key(char *hexkey, size_t key_size, const char *key)
 252 {
 253         unsigned i;
 254
 255         for(i = 0; i < key_size; i++)
 256                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 257 }
 258
 259 /* http://code.google.com/p/cryptsetup/wiki/DMCrypt */
 260 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 261 {
 262         int r, max_size, null_cipher = 0;
 263         char *params, *hexkey;
 264         const char *features = "";
 265
 266         if (!dmd)
 267                 return NULL;
 268
 269         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 270                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 271                         features = " 1 allow_discards";
 272                         log_dbg("Discard/TRIM is allowed.");
 273                 } else
 274                         log_dbg("Discard/TRIM is not supported by the kernel.");
 275         }
 276
 277         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 278                 null_cipher = 1;
 279
 280         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 281         if (!hexkey)
 282                 return NULL;
 283
 284         if (null_cipher)
 285                 strncpy(hexkey, "-", 2);
 286         else
 287                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 288
 289         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 290                    strlen(dmd->data_device) + strlen(features) + 64;
 291         params = crypt_safe_alloc(max_size);
 292         if (!params)
 293                 goto out;
 294
 295         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 296                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 297                      dmd->data_device, dmd->u.crypt.offset, features);
 298         if (r < 0 || r >= max_size) {
 299                 crypt_safe_free(params);
 300                 params = NULL;
 301         }
 302 out:
 303         crypt_safe_free(hexkey);
 304         return params;
 305 }
 306
 307 /* http://code.google.com/p/cryptsetup/wiki/DMVerity */
 308 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 309                                    struct crypt_dm_active_device *dmd)
 310 {
 311         int max_size, r;
 312         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 313
 314         if (!vp || !dmd)
 315                 return NULL;
 316
 317         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 318         if (!hexroot)
 319                 goto out;
 320         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 321
 322         hexsalt = crypt_safe_alloc(vp->salt_size ? vp->salt_size * 2 + 1 : 2);
 323         if (!hexsalt)
 324                 goto out;
 325         if (vp->salt_size)
 326                 hex_key(hexsalt, vp->salt_size, vp->salt);
 327         else
 328                 strncpy(hexsalt, "-", 2);
 329
 330         max_size = strlen(hexroot) + strlen(hexsalt) +
 331                    strlen(dmd->data_device) +
 332                    strlen(dmd->u.verity.hash_device) +
 333                    strlen(vp->hash_name) + 128;
 334
 335         params = crypt_safe_alloc(max_size);
 336         if (!params)
 337                 goto out;
 338
 339         r = snprintf(params, max_size,
 340                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 341                      vp->hash_type, dmd->data_device,
 342                      dmd->u.verity.hash_device,
 343                      vp->data_block_size, vp->hash_block_size,
 344                      vp->data_size, dmd->u.verity.hash_offset,
 345                      vp->hash_name, hexroot, hexsalt);
 346         if (r < 0 || r >= max_size) {
 347                 crypt_safe_free(params);
 348                 params = NULL;
 349         }
 350 out:
 351         crypt_safe_free(hexroot);
 352         crypt_safe_free(hexsalt);
 353         return params;
 354
 355 }
 356
 357 /* DM helpers */
 358 static int _dm_simple(int task, const char *name, int udev_wait)
 359 {
 360         int r = 0;
 361         struct dm_task *dmt;
 362         uint32_t cookie = 0;
 363
 364         if (!_dm_use_udev())
 365                 udev_wait = 0;
 366
 367         if (!(dmt = dm_task_create(task)))
 368                 return 0;
 369
 370         if (name && !dm_task_set_name(dmt, name))
 371                 goto out;
 372
 373 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 374         /* Used only in DM_DEVICE_REMOVE */
 375         if (name && !dm_task_retry_remove(dmt))
 376                 goto out;
 377 #endif
 378         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 379                 goto out;
 380
 381         r = dm_task_run(dmt);
 382
 383         if (udev_wait)
 384                 (void)_dm_udev_wait(cookie);
 385
 386       out:
 387         dm_task_destroy(dmt);
 388         return r;
 389 }
 390
 391 static int _error_device(const char *name, size_t size)
 392 {
 393         struct dm_task *dmt;
 394         int r = 0;
 395
 396         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 397                 return 0;
 398
 399         if (!dm_task_set_name(dmt, name))
 400                 goto error;
 401
 402         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 403                 goto error;
 404
 405         if (!dm_task_set_ro(dmt))
 406                 goto error;
 407
 408         if (!dm_task_no_open_count(dmt))
 409                 goto error;
 410
 411         if (!dm_task_run(dmt))
 412                 goto error;
 413
 414         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 415                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 416                 goto error;
 417         }
 418
 419         r = 1;
 420
 421 error:
 422         dm_task_destroy(dmt);
 423         return r;
 424 }
 425
 426 int dm_remove_device(const char *name, int force, uint64_t size)
 427 {
 428         int r = -EINVAL;
 429         int retries = force ? RETRY_COUNT : 1;
 430         int error_target = 0;
 431
 432         if (!name || (force && !size))
 433                 return -EINVAL;
 434
 435         do {
 436                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 437                 if (--retries && r) {
 438                         log_dbg("WARNING: other process locked internal device %s, %s.",
 439                                 name, retries ? "retrying remove" : "giving up");
 440                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 441                                 debug_processes_using_device(name);
 442                         sleep(1);
 443                         if (force && !error_target) {
 444                                 /* If force flag is set, replace device with error, read-only target.
 445                                  * it should stop processes from reading it and also removed underlying
 446                                  * device from mapping, so it is usable again.
 447                                  * Force flag should be used only for temporary devices, which are
 448                                  * intended to work inside cryptsetup only!
 449                                  * Anyway, if some process try to read temporary cryptsetup device,
 450                                  * it is bug - no other process should try touch it (e.g. udev).
 451                                  */
 452                                 _error_device(name, size);
 453                                 error_target = 1;
 454                         }
 455                 }
 456         } while (r == -EINVAL && retries);
 457
 458         dm_task_update_nodes();
 459
 460         return r;
 461 }
 462
 463 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 464 /*
 465  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 466  * CRYPT-PLAIN-name
 467  * CRYPT-LUKS1-00000000000000000000000000000000-name
 468  * CRYPT-TEMP-name
 469  */
 470 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 471 {
 472         char *ptr, uuid2[UUID_LEN] = {0};
 473         uuid_t uu;
 474         unsigned i = 0;
 475
 476         /* Remove '-' chars */
 477         if (uuid && !uuid_parse(uuid, uu)) {
 478                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 479                         if (uuid[i] != '-') {
 480                                 *ptr = uuid[i];
 481                                 ptr++;
 482                         }
 483         }
 484
 485         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 486                 type ?: "", type ? "-" : "",
 487                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 488                 name);
 489
 490         log_dbg("DM-UUID is %s", buf);
 491         if (i >= buflen)
 492                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 493 }
 494
 495 static int _dm_create_device(const char *name, const char *type,
 496                              const char *device, uint32_t flags,
 497                              const char *uuid, uint64_t size,
 498                              char *params, int reload)
 499 {
 500         struct dm_task *dmt = NULL;
 501         struct dm_info dmi;
 502         char dev_uuid[DM_UUID_LEN] = {0};
 503         int r = -EINVAL;
 504         uint32_t read_ahead = 0;
 505         uint32_t cookie = 0;
 506         uint16_t udev_flags = 0;
 507
 508         if (flags & CRYPT_ACTIVATE_PRIVATE)
 509                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 510
 511         /* All devices must have DM_UUID, only resize on old device is exception */
 512         if (reload) {
 513                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 514                         goto out_no_removal;
 515
 516                 if (!dm_task_set_name(dmt, name))
 517                         goto out_no_removal;
 518         } else {
 519                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 520
 521                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 522                         goto out_no_removal;
 523
 524                 if (!dm_task_set_name(dmt, name))
 525                         goto out_no_removal;
 526
 527                 if (!dm_task_set_uuid(dmt, dev_uuid))
 528                         goto out_no_removal;
 529
 530                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 531                         goto out_no_removal;
 532         }
 533
 534         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 535                 goto out_no_removal;
 536         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 537                 goto out_no_removal;
 538
 539         if (!dm_task_add_target(dmt, 0, size,
 540                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 541                 goto out_no_removal;
 542
 543 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 544         if (device_read_ahead(device, &read_ahead) &&
 545             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 546                 goto out_no_removal;
 547 #endif
 548
 549         if (!dm_task_run(dmt))
 550                 goto out_no_removal;
 551
 552         if (reload) {
 553                 dm_task_destroy(dmt);
 554                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 555                         goto out;
 556                 if (!dm_task_set_name(dmt, name))
 557                         goto out;
 558                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 559                         goto out;
 560                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 561                         goto out;
 562                 if (!dm_task_run(dmt))
 563                         goto out;
 564         }
 565
 566         if (!dm_task_get_info(dmt, &dmi))
 567                 goto out;
 568
 569         r = 0;
 570 out:
 571         if (_dm_use_udev()) {
 572                 (void)_dm_udev_wait(cookie);
 573                 cookie = 0;
 574         }
 575
 576         if (r < 0 && !reload)
 577                 dm_remove_device(name, 0, 0);
 578
 579 out_no_removal:
 580         if (cookie && _dm_use_udev())
 581                 (void)_dm_udev_wait(cookie);
 582
 583         if (params)
 584                 crypt_safe_free(params);
 585         if (dmt)
 586                 dm_task_destroy(dmt);
 587
 588         dm_task_update_nodes();
 589         return r;
 590 }
 591
 592 int dm_create_device(const char *name,
 593                      const char *type,
 594                      struct crypt_dm_active_device *dmd,
 595                      int reload)
 596 {
 597         char *table_params = NULL;
 598
 599         if (dmd->target == DM_CRYPT)
 600                 table_params = get_dm_crypt_params(dmd);
 601         else if (dmd->target == DM_VERITY)
 602                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 603
 604         if (!table_params || !type)
 605                 return -EINVAL;
 606
 607         return _dm_create_device(name, type, dmd->data_device, dmd->flags,
 608                                  dmd->uuid, dmd->size, table_params, reload);
 609 }
 610
 611 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 612                           const char *target, char **status_line)
 613 {
 614         struct dm_task *dmt;
 615         uint64_t start, length;
 616         char *target_type, *params = NULL;
 617         void *next = NULL;
 618         int r = -EINVAL;
 619
 620         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 621                 goto out;
 622
 623         if (!dm_task_set_name(dmt, name))
 624                 goto out;
 625
 626         if (!dm_task_run(dmt))
 627                 goto out;
 628
 629         if (!dm_task_get_info(dmt, dmi))
 630                 goto out;
 631
 632         if (!dmi->exists) {
 633                 r = -ENODEV;
 634                 goto out;
 635         }
 636
 637         next = dm_get_next_target(dmt, next, &start, &length,
 638                                   &target_type, &params);
 639
 640         if (!target_type || start != 0 || next)
 641                 goto out;
 642
 643         if (target && strcmp(target_type, target))
 644                 goto out;
 645
 646         /* for target == NULL check all supported */
 647         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 648                         strcmp(target_type, DM_VERITY_TARGET)))
 649                 goto out;
 650         r = 0;
 651 out:
 652         if (!r && status_line && !(*status_line = strdup(params)))
 653                 r = -ENOMEM;
 654
 655         if (dmt)
 656                 dm_task_destroy(dmt);
 657
 658         return r;
 659 }
 660
 661 int dm_status_device(const char *name)
 662 {
 663         int r;
 664         struct dm_info dmi;
 665
 666         r = dm_status_dmi(name, &dmi, NULL, NULL);
 667         if (r < 0)
 668                 return r;
 669
 670         return (dmi.open_count > 0);
 671 }
 672
 673 int dm_status_suspended(const char *name)
 674 {
 675         int r;
 676         struct dm_info dmi;
 677
 678         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 679         if (r < 0)
 680                 return r;
 681
 682         return dmi.suspended ? 1 : 0;
 683 }
 684
 685 int dm_status_verity_ok(const char *name)
 686 {
 687         int r;
 688         struct dm_info dmi;
 689         char *status_line = NULL;
 690
 691         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 692         if (r < 0 || !status_line) {
 693                 free(status_line);
 694                 return r;
 695         }
 696
 697         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 698         r = status_line[0] == 'V' ? 1 : 0;
 699         free(status_line);
 700
 701         return r;
 702 }
 703
 704 /* FIXME use hex wrapper, user val wrappers for line parsing */
 705 static int _dm_query_crypt(uint32_t get_flags,
 706                            struct dm_info *dmi,
 707                            char *params,
 708                            struct crypt_dm_active_device *dmd)
 709 {
 710         uint64_t val64;
 711         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 712         unsigned int i;
 713
 714         memset(dmd, 0, sizeof(*dmd));
 715         dmd->target = DM_CRYPT;
 716
 717         rcipher = strsep(&params, " ");
 718         /* cipher */
 719         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 720                 dmd->u.crypt.cipher = strdup(rcipher);
 721
 722         /* skip */
 723         key_ = strsep(&params, " ");
 724         if (!params)
 725                 return -EINVAL;
 726         val64 = strtoull(params, &params, 10);
 727         if (*params != ' ')
 728                 return -EINVAL;
 729         params++;
 730
 731         dmd->u.crypt.iv_offset = val64;
 732
 733         /* device */
 734         rdevice = strsep(&params, " ");
 735         if (get_flags & DM_ACTIVE_DEVICE)
 736                 dmd->data_device = crypt_lookup_dev(rdevice);
 737
 738         /*offset */
 739         if (!params)
 740                 return -EINVAL;
 741         val64 = strtoull(params, &params, 10);
 742         dmd->u.crypt.offset = val64;
 743
 744         /* Features section, available since crypt target version 1.11 */
 745         if (*params) {
 746                 if (*params != ' ')
 747                         return -EINVAL;
 748                 params++;
 749
 750                 /* Number of arguments */
 751                 val64 = strtoull(params, &params, 10);
 752                 if (*params != ' ')
 753                         return -EINVAL;
 754                 params++;
 755
 756                 for (i = 0; i < val64; i++) {
 757                         if (!params)
 758                                 return -EINVAL;
 759                         arg = strsep(&params, " ");
 760                         if (!strcasecmp(arg, "allow_discards"))
 761                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 762                         else /* unknown option */
 763                                 return -EINVAL;
 764                 }
 765
 766                 /* All parameters shold be processed */
 767                 if (params)
 768                         return -EINVAL;
 769         }
 770
 771         /* Never allow to return empty key */
 772         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 773                 log_dbg("Cannot read volume key while suspended.");
 774                 return -EINVAL;
 775         }
 776
 777         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 778                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 779                 if (!dmd->u.crypt.vk)
 780                         return -ENOMEM;
 781
 782                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 783                         buffer[2] = '\0';
 784                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 785                                 memcpy(buffer, &key_[i * 2], 2);
 786                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 787                                 if (endp != &buffer[2]) {
 788                                         crypt_free_volume_key(dmd->u.crypt.vk);
 789                                         dmd->u.crypt.vk = NULL;
 790                                         return -EINVAL;
 791                                 }
 792                         }
 793                 }
 794         }
 795         memset(key_, 0, strlen(key_));
 796
 797         return 0;
 798 }
 799
 800 static int _dm_query_verity(uint32_t get_flags,
 801                              struct dm_info *dmi,
 802                              char *params,
 803                              struct crypt_dm_active_device *dmd)
 804 {
 805         struct crypt_params_verity *vp = NULL;
 806         uint32_t val32;
 807         uint64_t val64;
 808         ssize_t len;
 809         char *str, *str2;
 810
 811         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 812                 vp = dmd->u.verity.vp;
 813
 814         memset(dmd, 0, sizeof(*dmd));
 815
 816         dmd->target = DM_VERITY;
 817         dmd->u.verity.vp = vp;
 818
 819         /* version */
 820         val32 = strtoul(params, &params, 10);
 821         if (*params != ' ')
 822                 return -EINVAL;
 823         if (vp)
 824                 vp->hash_type = val32;
 825         params++;
 826
 827         /* data device */
 828         str = strsep(&params, " ");
 829         if (!params)
 830                 return -EINVAL;
 831         if (get_flags & DM_ACTIVE_DEVICE)
 832                 dmd->data_device = crypt_lookup_dev(str);
 833
 834         /* hash device */
 835         str = strsep(&params, " ");
 836         if (!params)
 837                 return -EINVAL;
 838         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE)
 839                 dmd->u.verity.hash_device = crypt_lookup_dev(str);
 840
 841         /* data block size*/
 842         val32 = strtoul(params, &params, 10);
 843         if (*params != ' ')
 844                 return -EINVAL;
 845         if (vp)
 846                 vp->data_block_size = val32;
 847         params++;
 848
 849         /* hash block size */
 850         val32 = strtoul(params, &params, 10);
 851         if (*params != ' ')
 852                 return -EINVAL;
 853         if (vp)
 854                 vp->hash_block_size = val32;
 855         params++;
 856
 857         /* data blocks */
 858         val64 = strtoull(params, &params, 10);
 859         if (*params != ' ')
 860                 return -EINVAL;
 861         if (vp)
 862                 vp->data_size = val64;
 863         params++;
 864
 865         /* hash start */
 866         val64 = strtoull(params, &params, 10);
 867         if (*params != ' ')
 868                 return -EINVAL;
 869         dmd->u.verity.hash_offset = val64;
 870         params++;
 871
 872         /* hash algorithm */
 873         str = strsep(&params, " ");
 874         if (!params)
 875                 return -EINVAL;
 876         if (vp)
 877                 vp->hash_name = strdup(str);
 878
 879         /* root digest */
 880         str = strsep(&params, " ");
 881         if (!params)
 882                 return -EINVAL;
 883         len = crypt_hex_to_bytes(str, &str2, 0);
 884         if (len < 0)
 885                 return len;
 886         dmd->u.verity.root_hash_size = len;
 887         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH)
 888                 dmd->u.verity.root_hash = str2;
 889         else
 890                 free(str2);
 891
 892         /* salt */
 893         str = strsep(&params, " ");
 894         if (params)
 895                 return -EINVAL;
 896         if (vp) {
 897                 if (!strcmp(str, "-")) {
 898                         vp->salt_size = 0;
 899                         vp->salt = NULL;
 900                 } else {
 901                         len = crypt_hex_to_bytes(str, &str2, 0);
 902                         if (len < 0)
 903                                 return len;
 904                         vp->salt_size = len;
 905                         vp->salt = str2;
 906                 }
 907         }
 908
 909         return 0;
 910 }
 911
 912 int dm_query_device(const char *name, uint32_t get_flags,
 913                     struct crypt_dm_active_device *dmd)
 914 {
 915         struct dm_task *dmt;
 916         struct dm_info dmi;
 917         uint64_t start, length;
 918         char *target_type, *params;
 919         const char *tmp_uuid;
 920         void *next = NULL;
 921         int r = -EINVAL;
 922
 923         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 924                 goto out;
 925         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 926                 goto out;
 927         if (!dm_task_set_name(dmt, name))
 928                 goto out;
 929         r = -ENODEV;
 930         if (!dm_task_run(dmt))
 931                 goto out;
 932
 933         r = -EINVAL;
 934         if (!dm_task_get_info(dmt, &dmi))
 935                 goto out;
 936
 937         if (!dmi.exists) {
 938                 r = -ENODEV;
 939                 goto out;
 940         }
 941
 942         next = dm_get_next_target(dmt, next, &start, &length,
 943                                   &target_type, &params);
 944
 945         if (!target_type || start != 0 || next)
 946                 goto out;
 947
 948         if (!strcmp(target_type, DM_CRYPT_TARGET)) {
 949                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
 950         } else if (!strcmp(target_type, DM_VERITY_TARGET)) {
 951                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
 952                 if (r < 0)
 953                         goto out;
 954                 r = dm_status_verity_ok(name);
 955                 if (r < 0)
 956                         goto out;
 957                 if (r == 0)
 958                         dmd->flags |= CRYPT_ACTIVATE_CORRUPTED;
 959                 r = 0;
 960         } else
 961                 r = -EINVAL;
 962
 963         if (r < 0)
 964                 goto out;
 965
 966         dmd->size = length;
 967
 968         if (dmi.read_only)
 969                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 970
 971         tmp_uuid = dm_task_get_uuid(dmt);
 972         if (!tmp_uuid)
 973                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 974         else if (get_flags & DM_ACTIVE_UUID) {
 975                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 976                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 977         }
 978
 979         r = (dmi.open_count > 0);
 980 out:
 981         if (dmt)
 982                 dm_task_destroy(dmt);
 983
 984         return r;
 985 }
 986
 987 static int _dm_message(const char *name, const char *msg)
 988 {
 989         int r = 0;
 990         struct dm_task *dmt;
 991
 992         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 993                 return 0;
 994
 995         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 996                 goto out;
 997
 998         if (name && !dm_task_set_name(dmt, name))
 999                 goto out;
1000
1001         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1002                 goto out;
1003
1004         if (!dm_task_set_message(dmt, msg))
1005                 goto out;
1006
1007         r = dm_task_run(dmt);
1008
1009       out:
1010         dm_task_destroy(dmt);
1011         return r;
1012 }
1013
1014 int dm_suspend_and_wipe_key(const char *name)
1015 {
1016         if (!_dm_check_versions())
1017                 return -ENOTSUP;
1018
1019         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1020                 return -ENOTSUP;
1021
1022         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
1023                 return -EINVAL;
1024
1025         if (!_dm_message(name, "key wipe")) {
1026                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1027                 return -EINVAL;
1028         }
1029
1030         return 0;
1031 }
1032
1033 int dm_resume_and_reinstate_key(const char *name,
1034                                 size_t key_size,
1035                                 const char *key)
1036 {
1037         int msg_size = key_size * 2 + 10; // key set <key>
1038         char *msg;
1039         int r = 0;
1040
1041         if (!_dm_check_versions())
1042                 return -ENOTSUP;
1043
1044         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1045                 return -ENOTSUP;
1046
1047         msg = crypt_safe_alloc(msg_size);
1048         if (!msg)
1049                 return -ENOMEM;
1050
1051         memset(msg, 0, msg_size);
1052         strcpy(msg, "key set ");
1053         hex_key(&msg[8], key_size, key);
1054
1055         if (!_dm_message(name, msg) ||
1056             !_dm_simple(DM_DEVICE_RESUME, name, 1))
1057                 r = -EINVAL;
1058
1059         crypt_safe_free(msg);
1060         return r;
1061 }
1062
1063 const char *dm_get_dir(void)
1064 {
1065         return dm_dir();
1066 }
1067
1068 int dm_is_dm_device(int major, int minor)
1069 {
1070         return dm_is_dm_major((uint32_t)major);
1071 }
1072
1073 int dm_is_dm_kernel_name(const char *name)
1074 {
1075         return strncmp(name, "dm-", 3) ? 0 : 1;
1076 }
1077
1078 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
1079 {
1080         struct crypt_dm_active_device dmd;
1081         int r;
1082
1083         log_dbg("Checking segments for device %s.", name);
1084
1085         r = dm_query_device(name, 0, &dmd);
1086         if (r < 0)
1087                 return r;
1088
1089         if (offset >= (dmd.u.crypt.offset + dmd.size) ||
1090            (offset + size) <= dmd.u.crypt.offset)
1091                 r = 0;
1092         else
1093                 r = -EBUSY;
1094
1095         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
1096                dmd.u.crypt.offset, dmd.u.crypt.offset + dmd.size, offset, offset + size,
1097                r ? " (overlapping)" : " (ok)");
1098
1099         return r;
1100 }