lib/libdevmapper.c

   1 /*
   2  * libdevmapper - device-mapper backend for cryptsetup
   3  *
   4  * Copyright (C) 2004, Christophe Saout <christophe@saout.de>
   5  * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
   6  * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25 #include <libdevmapper.h>
  26 #include <fcntl.h>
  27 #include <linux/fs.h>
  28 #include <uuid/uuid.h>
  29
  30 #include "internal.h"
  31
  32 #define DM_UUID_LEN             129
  33 #define DM_UUID_PREFIX          "CRYPT-"
  34 #define DM_UUID_PREFIX_LEN      6
  35 #define DM_CRYPT_TARGET         "crypt"
  36 #define DM_VERITY_TARGET        "verity"
  37 #define RETRY_COUNT             5
  38
  39 /* Set if dm-crypt version was probed */
  40 static int _dm_crypt_checked = 0;
  41 static uint32_t _dm_crypt_flags = 0;
  42
  43 static int _dm_use_count = 0;
  44 static struct crypt_device *_context = NULL;
  45
  46 /* Check if we have DM flag to instruct kernel to force wipe buffers */
  47 #if !HAVE_DECL_DM_TASK_SECURE_DATA
  48 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
  49 #endif
  50
  51 /* Compatibility for old device-mapper without udev support */
  52 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
  53 #define CRYPT_TEMP_UDEV_FLAGS   DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
  54                                 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
  55                                 DM_UDEV_DISABLE_OTHER_RULES_FLAG
  56 #define _dm_task_set_cookie     dm_task_set_cookie
  57 #define _dm_udev_wait           dm_udev_wait
  58 #else
  59 #define CRYPT_TEMP_UDEV_FLAGS   0
  60 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
  61 static int _dm_udev_wait(uint32_t cookie) { return 0; };
  62 #endif
  63
  64 static int _dm_use_udev(void)
  65 {
  66 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
  67         return dm_udev_get_sync_support();
  68 #else
  69         return 0;
  70 #endif
  71 }
  72
  73 __attribute__((format(printf, 4, 5)))
  74 static void set_dm_error(int level,
  75                          const char *file __attribute__((unused)),
  76                          int line __attribute__((unused)),
  77                          const char *f, ...)
  78 {
  79         char *msg = NULL;
  80         va_list va;
  81
  82         va_start(va, f);
  83         if (vasprintf(&msg, f, va) > 0) {
  84                 if (level < 4) {
  85                         log_err(_context, msg);
  86                         log_err(_context, "\n");
  87                 } else
  88                         log_dbg(msg);
  89         }
  90         free(msg);
  91         va_end(va);
  92 }
  93
  94 static int _dm_simple(int task, const char *name, int udev_wait);
  95
  96 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
  97                                  unsigned crypt_min, unsigned crypt_patch)
  98 {
  99         unsigned dm_maj, dm_min, dm_patch;
 100
 101         if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
 102                 dm_maj = dm_min = dm_patch = 0;
 103
 104         log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
 105                 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
 106
 107         if (crypt_maj >= 1 && crypt_min >= 2)
 108                 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
 109         else
 110                 log_dbg("Suspend and resume disabled, no wipe key support.");
 111
 112         if (crypt_maj >= 1 && crypt_min >= 10)
 113                 _dm_crypt_flags |= DM_LMK_SUPPORTED;
 114
 115         if (dm_maj >= 4 && dm_min >= 20)
 116                 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
 117
 118         /* not perfect, 2.6.33 supports with 1.7.0 */
 119         if (crypt_maj >= 1 && crypt_min >= 8)
 120                 _dm_crypt_flags |= DM_PLAIN64_SUPPORTED;
 121
 122         if (crypt_maj >= 1 && crypt_min >= 11)
 123                 _dm_crypt_flags |= DM_DISCARDS_SUPPORTED;
 124
 125         /* Repeat test if dm-crypt is not present */
 126         if (crypt_maj > 0)
 127                 _dm_crypt_checked = 1;
 128 }
 129
 130 static void _dm_set_verity_compat(const char *dm_version, unsigned verity_maj,
 131                                    unsigned verity_min, unsigned verity_patch)
 132 {
 133         if (verity_maj > 0)
 134                 _dm_crypt_flags |= DM_VERITY_SUPPORTED;
 135
 136         log_dbg("Detected dm-verity version %i.%i.%i.",
 137                 verity_maj, verity_min, verity_patch);
 138 }
 139
 140 static int _dm_check_versions(void)
 141 {
 142         struct dm_task *dmt;
 143         struct dm_versions *target, *last_target;
 144         char dm_version[16];
 145
 146         if (_dm_crypt_checked)
 147                 return 1;
 148
 149         /* FIXME: add support to DM so it forces crypt target module load here */
 150         if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
 151                 return 0;
 152
 153         if (!dm_task_run(dmt)) {
 154                 dm_task_destroy(dmt);
 155                 return 0;
 156         }
 157
 158         if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
 159                 dm_task_destroy(dmt);
 160                 return 0;
 161         }
 162
 163         target = dm_task_get_versions(dmt);
 164         do {
 165                 last_target = target;
 166                 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
 167                         _dm_set_crypt_compat(dm_version,
 168                                              (unsigned)target->version[0],
 169                                              (unsigned)target->version[1],
 170                                              (unsigned)target->version[2]);
 171                 } else if (!strcmp(DM_VERITY_TARGET, target->name)) {
 172                         _dm_set_verity_compat(dm_version,
 173                                              (unsigned)target->version[0],
 174                                              (unsigned)target->version[1],
 175                                              (unsigned)target->version[2]);
 176                 }
 177                 target = (struct dm_versions *)((char *) target + target->next);
 178         } while (last_target != target);
 179
 180         dm_task_destroy(dmt);
 181         return 1;
 182 }
 183
 184 uint32_t dm_flags(void)
 185 {
 186         if (!_dm_crypt_checked)
 187                 _dm_check_versions();
 188
 189         return _dm_crypt_flags;
 190 }
 191
 192 int dm_init(struct crypt_device *context, int check_kernel)
 193 {
 194         if (!_dm_use_count++) {
 195                 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
 196                         check_kernel ? "" : " (NO kernel check requested)",
 197                         _dm_use_udev() ? "en" : "dis");
 198                 if (check_kernel && !_dm_check_versions()) {
 199                         log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
 200                         return -1;
 201                 }
 202                 if (getuid() || geteuid())
 203                         log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
 204                 dm_log_init(set_dm_error);
 205                 dm_log_init_verbose(10);
 206         }
 207
 208         // FIXME: global context is not safe
 209         if (context)
 210                 _context = context;
 211
 212         return 1;       /* unsafe memory */
 213 }
 214
 215 void dm_exit(void)
 216 {
 217         if (_dm_use_count && (!--_dm_use_count)) {
 218                 log_dbg("Releasing device-mapper backend.");
 219                 dm_log_init_verbose(0);
 220                 dm_log_init(NULL);
 221                 dm_lib_release();
 222                 _context = NULL;
 223         }
 224 }
 225
 226 /* Return path to DM device */
 227 char *dm_device_path(const char *prefix, int major, int minor)
 228 {
 229         struct dm_task *dmt;
 230         const char *name;
 231         char path[PATH_MAX];
 232
 233         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 234                 return NULL;
 235         if (!dm_task_set_minor(dmt, minor) ||
 236             !dm_task_set_major(dmt, major) ||
 237             !dm_task_run(dmt) ||
 238             !(name = dm_task_get_name(dmt))) {
 239                 dm_task_destroy(dmt);
 240                 return NULL;
 241         }
 242
 243         if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
 244                 path[0] = '\0';
 245
 246         dm_task_destroy(dmt);
 247
 248         return strdup(path);
 249 }
 250
 251 static void hex_key(char *hexkey, size_t key_size, const char *key)
 252 {
 253         unsigned i;
 254
 255         for(i = 0; i < key_size; i++)
 256                 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
 257 }
 258
 259 static int hex_to_bytes(const char *hex, char *result)
 260 {
 261         char buf[3] = "xx\0", *endp;
 262         int i, len;
 263
 264         len = strlen(hex) / 2;
 265         for (i = 0; i < len; i++) {
 266                 memcpy(buf, &hex[i * 2], 2);
 267                 result[i] = strtoul(buf, &endp, 16);
 268                 if (endp != &buf[2])
 269                         return -EINVAL;
 270         }
 271         return i;
 272 }
 273
 274 /* http://code.google.com/p/cryptsetup/wiki/DMCrypt */
 275 static char *get_dm_crypt_params(struct crypt_dm_active_device *dmd)
 276 {
 277         int r, max_size, null_cipher = 0;
 278         char *params, *hexkey;
 279         const char *features = "";
 280
 281         if (!dmd)
 282                 return NULL;
 283
 284         if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
 285                 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
 286                         features = " 1 allow_discards";
 287                         log_dbg("Discard/TRIM is allowed.");
 288                 } else
 289                         log_dbg("Discard/TRIM is not supported by the kernel.");
 290         }
 291
 292         if (!strncmp(dmd->u.crypt.cipher, "cipher_null-", 12))
 293                 null_cipher = 1;
 294
 295         hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->u.crypt.vk->keylength * 2 + 1));
 296         if (!hexkey)
 297                 return NULL;
 298
 299         if (null_cipher)
 300                 strncpy(hexkey, "-", 2);
 301         else
 302                 hex_key(hexkey, dmd->u.crypt.vk->keylength, dmd->u.crypt.vk->key);
 303
 304         max_size = strlen(hexkey) + strlen(dmd->u.crypt.cipher) +
 305                    strlen(dmd->data_device) + strlen(features) + 64;
 306         params = crypt_safe_alloc(max_size);
 307         if (!params)
 308                 goto out;
 309
 310         r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
 311                      dmd->u.crypt.cipher, hexkey, dmd->u.crypt.iv_offset,
 312                      dmd->data_device, dmd->u.crypt.offset, features);
 313         if (r < 0 || r >= max_size) {
 314                 crypt_safe_free(params);
 315                 params = NULL;
 316         }
 317 out:
 318         crypt_safe_free(hexkey);
 319         return params;
 320 }
 321
 322 /* http://code.google.com/p/cryptsetup/wiki/DMVerity */
 323 static char *get_dm_verity_params(struct crypt_params_verity *vp,
 324                                    struct crypt_dm_active_device *dmd)
 325 {
 326         int max_size, r;
 327         char *params = NULL, *hexroot = NULL, *hexsalt = NULL;
 328
 329         if (!vp || !dmd)
 330                 return NULL;
 331
 332         hexroot = crypt_safe_alloc(dmd->u.verity.root_hash_size * 2 + 1);
 333         if (!hexroot)
 334                 goto out;
 335         hex_key(hexroot, dmd->u.verity.root_hash_size, dmd->u.verity.root_hash);
 336
 337         hexsalt = crypt_safe_alloc(vp->salt_size * 2 + 1);
 338         if (!hexsalt)
 339                 goto out;
 340         hex_key(hexsalt, vp->salt_size, vp->salt);
 341
 342         max_size = strlen(hexroot) + strlen(hexsalt) +
 343                    strlen(dmd->data_device) +
 344                    strlen(dmd->u.verity.hash_device) +
 345                    strlen(vp->hash_name) + 128;
 346
 347         params = crypt_safe_alloc(max_size);
 348         if (!params)
 349                 goto out;
 350
 351         r = snprintf(params, max_size,
 352                      "%u %s %s %u %u %" PRIu64 " %" PRIu64 " %s %s %s",
 353                      vp->version, dmd->data_device,
 354                      dmd->u.verity.hash_device,
 355                      vp->data_block_size, vp->hash_block_size,
 356                      vp->data_size, dmd->u.verity.hash_offset,
 357                      vp->hash_name, hexroot, hexsalt);
 358         if (r < 0 || r >= max_size) {
 359                 crypt_safe_free(params);
 360                 params = NULL;
 361         }
 362         log_dbg("TABLE: %s", params);
 363 out:
 364         crypt_safe_free(hexroot);
 365         crypt_safe_free(hexsalt);
 366         return params;
 367
 368 }
 369
 370 /* DM helpers */
 371 static int _dm_simple(int task, const char *name, int udev_wait)
 372 {
 373         int r = 0;
 374         struct dm_task *dmt;
 375         uint32_t cookie = 0;
 376
 377         if (!_dm_use_udev())
 378                 udev_wait = 0;
 379
 380         if (!(dmt = dm_task_create(task)))
 381                 return 0;
 382
 383         if (name && !dm_task_set_name(dmt, name))
 384                 goto out;
 385
 386 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
 387         /* Used only in DM_DEVICE_REMOVE */
 388         if (name && !dm_task_retry_remove(dmt))
 389                 goto out;
 390 #endif
 391         if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
 392                 goto out;
 393
 394         r = dm_task_run(dmt);
 395
 396         if (udev_wait)
 397                 (void)_dm_udev_wait(cookie);
 398
 399       out:
 400         dm_task_destroy(dmt);
 401         return r;
 402 }
 403
 404 static int _error_device(const char *name, size_t size)
 405 {
 406         struct dm_task *dmt;
 407         int r = 0;
 408
 409         if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 410                 return 0;
 411
 412         if (!dm_task_set_name(dmt, name))
 413                 goto error;
 414
 415         if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
 416                 goto error;
 417
 418         if (!dm_task_set_ro(dmt))
 419                 goto error;
 420
 421         if (!dm_task_no_open_count(dmt))
 422                 goto error;
 423
 424         if (!dm_task_run(dmt))
 425                 goto error;
 426
 427         if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
 428                 _dm_simple(DM_DEVICE_CLEAR, name, 0);
 429                 goto error;
 430         }
 431
 432         r = 1;
 433
 434 error:
 435         dm_task_destroy(dmt);
 436         return r;
 437 }
 438
 439 int dm_remove_device(const char *name, int force, uint64_t size)
 440 {
 441         int r = -EINVAL;
 442         int retries = force ? RETRY_COUNT : 1;
 443         int error_target = 0;
 444
 445         if (!name || (force && !size))
 446                 return -EINVAL;
 447
 448         do {
 449                 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
 450                 if (--retries && r) {
 451                         log_dbg("WARNING: other process locked internal device %s, %s.",
 452                                 name, retries ? "retrying remove" : "giving up");
 453                         if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
 454                                 debug_processes_using_device(name);
 455                         sleep(1);
 456                         if (force && !error_target) {
 457                                 /* If force flag is set, replace device with error, read-only target.
 458                                  * it should stop processes from reading it and also removed underlying
 459                                  * device from mapping, so it is usable again.
 460                                  * Force flag should be used only for temporary devices, which are
 461                                  * intended to work inside cryptsetup only!
 462                                  * Anyway, if some process try to read temporary cryptsetup device,
 463                                  * it is bug - no other process should try touch it (e.g. udev).
 464                                  */
 465                                 _error_device(name, size);
 466                                 error_target = 1;
 467                         }
 468                 }
 469         } while (r == -EINVAL && retries);
 470
 471         dm_task_update_nodes();
 472
 473         return r;
 474 }
 475
 476 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
 477 /*
 478  * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
 479  * CRYPT-PLAIN-name
 480  * CRYPT-LUKS1-00000000000000000000000000000000-name
 481  * CRYPT-TEMP-name
 482  */
 483 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
 484 {
 485         char *ptr, uuid2[UUID_LEN] = {0};
 486         uuid_t uu;
 487         unsigned i = 0;
 488
 489         /* Remove '-' chars */
 490         if (uuid && !uuid_parse(uuid, uu)) {
 491                 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
 492                         if (uuid[i] != '-') {
 493                                 *ptr = uuid[i];
 494                                 ptr++;
 495                         }
 496         }
 497
 498         i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
 499                 type ?: "", type ? "-" : "",
 500                 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
 501                 name);
 502
 503         log_dbg("DM-UUID is %s", buf);
 504         if (i >= buflen)
 505                 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
 506 }
 507
 508 static int _dm_create_device(const char *name, const char *type,
 509                              const char *device, uint32_t flags,
 510                              const char *uuid, uint64_t size,
 511                              char *params, int reload)
 512 {
 513         struct dm_task *dmt = NULL;
 514         struct dm_info dmi;
 515         char dev_uuid[DM_UUID_LEN] = {0};
 516         int r = -EINVAL;
 517         uint32_t read_ahead = 0;
 518         uint32_t cookie = 0;
 519         uint16_t udev_flags = 0;
 520
 521         if (flags & CRYPT_ACTIVATE_PRIVATE)
 522                 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
 523
 524         /* All devices must have DM_UUID, only resize on old device is exception */
 525         if (reload) {
 526                 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
 527                         goto out_no_removal;
 528
 529                 if (!dm_task_set_name(dmt, name))
 530                         goto out_no_removal;
 531         } else {
 532                 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
 533
 534                 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
 535                         goto out_no_removal;
 536
 537                 if (!dm_task_set_name(dmt, name))
 538                         goto out_no_removal;
 539
 540                 if (!dm_task_set_uuid(dmt, dev_uuid))
 541                         goto out_no_removal;
 542
 543                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 544                         goto out_no_removal;
 545         }
 546
 547         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 548                 goto out_no_removal;
 549         if ((flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
 550                 goto out_no_removal;
 551
 552         if (!dm_task_add_target(dmt, 0, size,
 553                 !strcmp("VERITY", type) ? DM_VERITY_TARGET : DM_CRYPT_TARGET, params))
 554                 goto out_no_removal;
 555
 556 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
 557         if (device_read_ahead(device, &read_ahead) &&
 558             !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
 559                 goto out_no_removal;
 560 #endif
 561
 562         if (!dm_task_run(dmt))
 563                 goto out_no_removal;
 564
 565         if (reload) {
 566                 dm_task_destroy(dmt);
 567                 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
 568                         goto out;
 569                 if (!dm_task_set_name(dmt, name))
 570                         goto out;
 571                 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
 572                         goto out;
 573                 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
 574                         goto out;
 575                 if (!dm_task_run(dmt))
 576                         goto out;
 577         }
 578
 579         if (!dm_task_get_info(dmt, &dmi))
 580                 goto out;
 581
 582         r = 0;
 583 out:
 584         if (_dm_use_udev()) {
 585                 (void)_dm_udev_wait(cookie);
 586                 cookie = 0;
 587         }
 588
 589         if (r < 0 && !reload)
 590                 dm_remove_device(name, 0, 0);
 591
 592 out_no_removal:
 593         if (cookie && _dm_use_udev())
 594                 (void)_dm_udev_wait(cookie);
 595
 596         if (params)
 597                 crypt_safe_free(params);
 598         if (dmt)
 599                 dm_task_destroy(dmt);
 600
 601         dm_task_update_nodes();
 602         return r;
 603 }
 604
 605 int dm_create_device(const char *name,
 606                      const char *type,
 607                      struct crypt_dm_active_device *dmd,
 608                      int reload)
 609 {
 610         char *table_params = NULL;
 611
 612         if (dmd->target == DM_CRYPT)
 613                 table_params = get_dm_crypt_params(dmd);
 614         else if (dmd->target == DM_VERITY)
 615                 table_params = get_dm_verity_params(dmd->u.verity.vp, dmd);
 616
 617         if (!table_params)
 618                 return -EINVAL;
 619
 620         return _dm_create_device(name, type, dmd->data_device, dmd->flags,
 621                                  dmd->uuid, dmd->size, table_params, reload);
 622 }
 623
 624 static int dm_status_dmi(const char *name, struct dm_info *dmi,
 625                           const char *target, char **status_line)
 626 {
 627         struct dm_task *dmt;
 628         uint64_t start, length;
 629         char *target_type, *params = NULL;
 630         void *next = NULL;
 631         int r = -EINVAL;
 632
 633         if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
 634                 goto out;
 635
 636         if (!dm_task_set_name(dmt, name))
 637                 goto out;
 638
 639         if (!dm_task_run(dmt))
 640                 goto out;
 641
 642         if (!dm_task_get_info(dmt, dmi))
 643                 goto out;
 644
 645         if (!dmi->exists) {
 646                 r = -ENODEV;
 647                 goto out;
 648         }
 649
 650         next = dm_get_next_target(dmt, next, &start, &length,
 651                                   &target_type, &params);
 652
 653         if (!target_type || start != 0 || next)
 654                 goto out;
 655
 656         if (target && strcmp(target_type, target))
 657                 goto out;
 658
 659         /* for target == NULL check all supported */
 660         if (!target && (strcmp(target_type, DM_CRYPT_TARGET) &&
 661                         strcmp(target_type, DM_VERITY_TARGET)))
 662                 goto out;
 663         r = 0;
 664 out:
 665         if (!r && status_line && !(*status_line = strdup(params)))
 666                 r = -ENOMEM;
 667
 668         if (dmt)
 669                 dm_task_destroy(dmt);
 670
 671         return r;
 672 }
 673
 674 int dm_status_device(const char *name)
 675 {
 676         int r;
 677         struct dm_info dmi;
 678
 679         r = dm_status_dmi(name, &dmi, NULL, NULL);
 680         if (r < 0)
 681                 return r;
 682
 683         return (dmi.open_count > 0);
 684 }
 685
 686 int dm_status_suspended(const char *name)
 687 {
 688         int r;
 689         struct dm_info dmi;
 690
 691         r = dm_status_dmi(name, &dmi, DM_CRYPT_TARGET, NULL);
 692         if (r < 0)
 693                 return r;
 694
 695         return dmi.suspended ? 1 : 0;
 696 }
 697
 698 int dm_status_verity_ok(const char *name)
 699 {
 700         int r;
 701         struct dm_info dmi;
 702         char *status_line = NULL;
 703
 704         r = dm_status_dmi(name, &dmi, DM_VERITY_TARGET, &status_line);
 705         if (r < 0 || !status_line) {
 706                 free(status_line);
 707                 return r;
 708         }
 709
 710         log_dbg("Verity volume %s status is %s.", name, status_line ?: "");
 711         r = status_line[0] == 'V' ? 1 : 0;
 712         free(status_line);
 713
 714         return r;
 715 }
 716
 717 /* FIXME use hex wrapper, user val wrappers for line parsing */
 718 static int _dm_query_crypt(uint32_t get_flags,
 719                            struct dm_info *dmi,
 720                            char *params,
 721                            struct crypt_dm_active_device *dmd)
 722 {
 723         uint64_t val64;
 724         char *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
 725         unsigned int i;
 726
 727         memset(dmd, 0, sizeof(*dmd));
 728         dmd->target = DM_CRYPT;
 729
 730         rcipher = strsep(&params, " ");
 731         /* cipher */
 732         if (get_flags & DM_ACTIVE_CRYPT_CIPHER)
 733                 dmd->u.crypt.cipher = strdup(rcipher);
 734
 735         /* skip */
 736         key_ = strsep(&params, " ");
 737         if (!params)
 738                 return -EINVAL;
 739         val64 = strtoull(params, &params, 10);
 740         if (*params != ' ')
 741                 return -EINVAL;
 742         params++;
 743
 744         dmd->u.crypt.iv_offset = val64;
 745
 746         /* device */
 747         rdevice = strsep(&params, " ");
 748         if (get_flags & DM_ACTIVE_DEVICE)
 749                 dmd->data_device = crypt_lookup_dev(rdevice);
 750
 751         /*offset */
 752         if (!params)
 753                 return -EINVAL;
 754         val64 = strtoull(params, &params, 10);
 755         dmd->u.crypt.offset = val64;
 756
 757         /* Features section, available since crypt target version 1.11 */
 758         if (*params) {
 759                 if (*params != ' ')
 760                         return -EINVAL;
 761                 params++;
 762
 763                 /* Number of arguments */
 764                 val64 = strtoull(params, &params, 10);
 765                 if (*params != ' ')
 766                         return -EINVAL;
 767                 params++;
 768
 769                 for (i = 0; i < val64; i++) {
 770                         if (!params)
 771                                 return -EINVAL;
 772                         arg = strsep(&params, " ");
 773                         if (!strcasecmp(arg, "allow_discards"))
 774                                 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 775                         else /* unknown option */
 776                                 return -EINVAL;
 777                 }
 778
 779                 /* All parameters shold be processed */
 780                 if (params)
 781                         return -EINVAL;
 782         }
 783
 784         /* Never allow to return empty key */
 785         if ((get_flags & DM_ACTIVE_CRYPT_KEY) && dmi->suspended) {
 786                 log_dbg("Cannot read volume key while suspended.");
 787                 return -EINVAL;
 788         }
 789
 790         if (get_flags & DM_ACTIVE_CRYPT_KEYSIZE) {
 791                 dmd->u.crypt.vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
 792                 if (!dmd->u.crypt.vk)
 793                         return -ENOMEM;
 794
 795                 if (get_flags & DM_ACTIVE_CRYPT_KEY) {
 796                         buffer[2] = '\0';
 797                         for(i = 0; i < dmd->u.crypt.vk->keylength; i++) {
 798                                 memcpy(buffer, &key_[i * 2], 2);
 799                                 dmd->u.crypt.vk->key[i] = strtoul(buffer, &endp, 16);
 800                                 if (endp != &buffer[2]) {
 801                                         crypt_free_volume_key(dmd->u.crypt.vk);
 802                                         dmd->u.crypt.vk = NULL;
 803                                         return -EINVAL;
 804                                 }
 805                         }
 806                 }
 807         }
 808         memset(key_, 0, strlen(key_));
 809
 810         return 0;
 811 }
 812
 813 static int _dm_query_verity(uint32_t get_flags,
 814                              struct dm_info *dmi,
 815                              char *params,
 816                              struct crypt_dm_active_device *dmd)
 817 {
 818         struct crypt_params_verity *vp = NULL;
 819         uint32_t val32;
 820         uint64_t val64;
 821         size_t len;
 822         char *str, *str2;
 823
 824         if (get_flags & DM_ACTIVE_VERITY_PARAMS)
 825                 vp = dmd->u.verity.vp;
 826
 827         memset(dmd, 0, sizeof(*dmd));
 828
 829         dmd->target = DM_VERITY;
 830         dmd->u.verity.vp = vp;
 831
 832         /* version */
 833         val32 = strtoul(params, &params, 10);
 834         if (*params != ' ')
 835                 return -EINVAL;
 836         if (vp)
 837                 vp->version = val32;
 838         params++;
 839
 840         /* data device */
 841         str = strsep(&params, " ");
 842         if (!params)
 843                 return -EINVAL;
 844         if (get_flags & DM_ACTIVE_DEVICE)
 845                 dmd->data_device = crypt_lookup_dev(str);
 846
 847         /* hash device */
 848         str = strsep(&params, " ");
 849         if (!params)
 850                 return -EINVAL;
 851         if (get_flags & DM_ACTIVE_VERITY_HASH_DEVICE)
 852                 dmd->u.verity.hash_device = crypt_lookup_dev(str);
 853
 854         /* data block size*/
 855         val32 = strtoul(params, &params, 10);
 856         if (*params != ' ')
 857                 return -EINVAL;
 858         if (vp)
 859                 vp->data_block_size = val32;
 860         params++;
 861
 862         /* hash block size */
 863         val32 = strtoul(params, &params, 10);
 864         if (*params != ' ')
 865                 return -EINVAL;
 866         if (vp)
 867                 vp->hash_block_size = val32;
 868         params++;
 869
 870         /* data blocks */
 871         val64 = strtoull(params, &params, 10);
 872         if (*params != ' ')
 873                 return -EINVAL;
 874         if (vp)
 875                 vp->data_size = val64;
 876         params++;
 877
 878         /* hash start */
 879         val64 = strtoull(params, &params, 10);
 880         if (*params != ' ')
 881                 return -EINVAL;
 882         dmd->u.verity.hash_offset = val64;
 883         params++;
 884
 885         /* hash algorithm */
 886         str = strsep(&params, " ");
 887         if (!params)
 888                 return -EINVAL;
 889         if (vp)
 890                 vp->hash_name = strdup(str);
 891
 892         /* root digest */
 893         str = strsep(&params, " ");
 894         if (!params)
 895                 return -EINVAL;
 896         len = strlen(str) / 2;
 897         dmd->u.verity.root_hash_size = len;
 898         if (get_flags & DM_ACTIVE_VERITY_ROOT_HASH) {
 899                 if (!(str2 = malloc(len)))
 900                         return -ENOMEM;
 901                 if (hex_to_bytes(str, str2) != len)
 902                         return -EINVAL;
 903                 dmd->u.verity.root_hash = str2;
 904         }
 905
 906         /* salt */
 907         str = strsep(&params, " ");
 908         if (params)
 909                 return -EINVAL;
 910         if (vp) {
 911                 len = strlen(str) / 2;
 912                 vp->salt_size = len;
 913                 if (!(str2 = malloc(len)))
 914                         return -ENOMEM;
 915                 if (hex_to_bytes(str, str2) != len)
 916                         return -EINVAL;
 917                 vp->salt = str2;
 918         }
 919
 920         return 0;
 921 }
 922
 923 int dm_query_device(const char *name, uint32_t get_flags,
 924                     struct crypt_dm_active_device *dmd)
 925 {
 926         struct dm_task *dmt;
 927         struct dm_info dmi;
 928         uint64_t start, length;
 929         char *target_type, *params;
 930         const char *tmp_uuid;
 931         void *next = NULL;
 932         int r = -EINVAL;
 933
 934         if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
 935                 goto out;
 936         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 937                 goto out;
 938         if (!dm_task_set_name(dmt, name))
 939                 goto out;
 940         r = -ENODEV;
 941         if (!dm_task_run(dmt))
 942                 goto out;
 943
 944         r = -EINVAL;
 945         if (!dm_task_get_info(dmt, &dmi))
 946                 goto out;
 947
 948         if (!dmi.exists) {
 949                 r = -ENODEV;
 950                 goto out;
 951         }
 952
 953         next = dm_get_next_target(dmt, next, &start, &length,
 954                                   &target_type, &params);
 955
 956         if (!target_type || start != 0 || next)
 957                 goto out;
 958
 959         if (!strcmp(target_type, DM_CRYPT_TARGET))
 960                 r = _dm_query_crypt(get_flags, &dmi, params, dmd);
 961         else if (!strcmp(target_type, DM_VERITY_TARGET))
 962                 r = _dm_query_verity(get_flags, &dmi, params, dmd);
 963         else
 964                 r = -EINVAL;
 965
 966         if (r < 0)
 967                 goto out;
 968
 969         dmd->size = length;
 970
 971         if (dmi.read_only)
 972                 dmd->flags |= CRYPT_ACTIVATE_READONLY;
 973
 974         tmp_uuid = dm_task_get_uuid(dmt);
 975         if (!tmp_uuid)
 976                 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
 977         else if (get_flags & DM_ACTIVE_UUID) {
 978                 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
 979                         dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
 980         }
 981
 982         r = (dmi.open_count > 0);
 983 out:
 984         if (dmt)
 985                 dm_task_destroy(dmt);
 986
 987         return r;
 988 }
 989
 990 static int _dm_message(const char *name, const char *msg)
 991 {
 992         int r = 0;
 993         struct dm_task *dmt;
 994
 995         if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
 996                 return 0;
 997
 998         if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
 999                 goto out;
1000
1001         if (name && !dm_task_set_name(dmt, name))
1002                 goto out;
1003
1004         if (!dm_task_set_sector(dmt, (uint64_t) 0))
1005                 goto out;
1006
1007         if (!dm_task_set_message(dmt, msg))
1008                 goto out;
1009
1010         r = dm_task_run(dmt);
1011
1012       out:
1013         dm_task_destroy(dmt);
1014         return r;
1015 }
1016
1017 int dm_suspend_and_wipe_key(const char *name)
1018 {
1019         if (!_dm_check_versions())
1020                 return -ENOTSUP;
1021
1022         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1023                 return -ENOTSUP;
1024
1025         if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
1026                 return -EINVAL;
1027
1028         if (!_dm_message(name, "key wipe")) {
1029                 _dm_simple(DM_DEVICE_RESUME, name, 1);
1030                 return -EINVAL;
1031         }
1032
1033         return 0;
1034 }
1035
1036 int dm_resume_and_reinstate_key(const char *name,
1037                                 size_t key_size,
1038                                 const char *key)
1039 {
1040         int msg_size = key_size * 2 + 10; // key set <key>
1041         char *msg;
1042         int r = 0;
1043
1044         if (!_dm_check_versions())
1045                 return -ENOTSUP;
1046
1047         if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
1048                 return -ENOTSUP;
1049
1050         msg = crypt_safe_alloc(msg_size);
1051         if (!msg)
1052                 return -ENOMEM;
1053
1054         memset(msg, 0, msg_size);
1055         strcpy(msg, "key set ");
1056         hex_key(&msg[8], key_size, key);
1057
1058         if (!_dm_message(name, msg) ||
1059             !_dm_simple(DM_DEVICE_RESUME, name, 1))
1060                 r = -EINVAL;
1061
1062         crypt_safe_free(msg);
1063         return r;
1064 }
1065
1066 const char *dm_get_dir(void)
1067 {
1068         return dm_dir();
1069 }
1070
1071 int dm_is_dm_device(int major, int minor)
1072 {
1073         return dm_is_dm_major((uint32_t)major);
1074 }
1075
1076 int dm_is_dm_kernel_name(const char *name)
1077 {
1078         return strncmp(name, "dm-", 3) ? 0 : 1;
1079 }
1080
1081 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
1082 {
1083         struct crypt_dm_active_device dmd;
1084         int r;
1085
1086         log_dbg("Checking segments for device %s.", name);
1087
1088         r = dm_query_device(name, 0, &dmd);
1089         if (r < 0)
1090                 return r;
1091
1092         if (offset >= (dmd.u.crypt.offset + dmd.size) ||
1093            (offset + size) <= dmd.u.crypt.offset)
1094                 r = 0;
1095         else
1096                 r = -EBUSY;
1097
1098         log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
1099                dmd.u.crypt.offset, dmd.u.crypt.offset + dmd.size, offset, offset + size,
1100                r ? " (overlapping)" : " (ok)");
1101
1102         return r;
1103 }