2 * libdevmapper - device-mapper backend for cryptsetup
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.
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.
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.
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.
25 #include <libdevmapper.h>
28 #include <uuid/uuid.h>
33 #define DM_UUID_LEN 129
34 #define DM_UUID_PREFIX "CRYPT-"
35 #define DM_UUID_PREFIX_LEN 6
36 #define DM_CRYPT_TARGET "crypt"
39 /* Set if dm-crypt version was probed */
40 static int _dm_crypt_checked = 0;
41 static uint32_t _dm_crypt_flags = 0;
43 static int _dm_use_count = 0;
44 static struct crypt_device *_context = NULL;
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; }
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
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; };
64 static int _dm_use_udev(void)
66 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
67 return dm_udev_get_sync_support();
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)),
83 if (vasprintf(&msg, f, va) > 0) {
85 log_err(_context, msg);
86 log_err(_context, "\n");
94 static int _dm_simple(int task, const char *name, int udev_wait);
96 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
97 unsigned crypt_min, unsigned crypt_patch)
99 unsigned dm_maj, dm_min, dm_patch;
101 if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
102 dm_maj = dm_min = dm_patch = 0;
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);
107 if (crypt_maj >= 1 && crypt_min >= 2)
108 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
110 log_dbg("Suspend and resume disabled, no wipe key support.");
112 if (crypt_maj >= 1 && crypt_min >= 10)
113 _dm_crypt_flags |= DM_LMK_SUPPORTED;
115 if (dm_maj >= 4 && dm_min >= 20)
116 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
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;
122 if (crypt_maj >= 1 && crypt_min >= 11)
123 _dm_crypt_flags |= DM_DISCARDS_SUPPORTED;
125 /* Repeat test if dm-crypt is not present */
127 _dm_crypt_checked = 1;
130 static int _dm_check_versions(void)
133 struct dm_versions *target, *last_target;
136 if (_dm_crypt_checked)
139 /* FIXME: add support to DM so it forces crypt target module load here */
140 if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
143 if (!dm_task_run(dmt)) {
144 dm_task_destroy(dmt);
148 if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
149 dm_task_destroy(dmt);
153 target = dm_task_get_versions(dmt);
155 last_target = target;
156 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
157 _dm_set_crypt_compat(dm_version,
158 (unsigned)target->version[0],
159 (unsigned)target->version[1],
160 (unsigned)target->version[2]);
162 target = (struct dm_versions *)((char *) target + target->next);
163 } while (last_target != target);
165 dm_task_destroy(dmt);
169 uint32_t dm_flags(void)
171 if (!_dm_crypt_checked)
172 _dm_check_versions();
174 return _dm_crypt_flags;
177 int dm_init(struct crypt_device *context, int check_kernel)
179 if (!_dm_use_count++) {
180 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
181 check_kernel ? "" : " (NO kernel check requested)",
182 _dm_use_udev() ? "en" : "dis");
183 if (check_kernel && !_dm_check_versions()) {
184 log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
187 if (getuid() || geteuid())
188 log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
189 dm_log_init(set_dm_error);
190 dm_log_init_verbose(10);
193 // FIXME: global context is not safe
197 return 1; /* unsafe memory */
202 if (_dm_use_count && (!--_dm_use_count)) {
203 log_dbg("Releasing device-mapper backend.");
204 dm_log_init_verbose(0);
211 /* Return path to DM device */
212 char *dm_device_path(const char *prefix, int major, int minor)
218 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
220 if (!dm_task_set_minor(dmt, minor) ||
221 !dm_task_set_major(dmt, major) ||
223 !(name = dm_task_get_name(dmt))) {
224 dm_task_destroy(dmt);
228 if (snprintf(path, sizeof(path), "%s%s", prefix ?: "", name) < 0)
231 dm_task_destroy(dmt);
236 static void hex_key(char *hexkey, size_t key_size, const char *key)
240 for(i = 0; i < key_size; i++)
241 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
244 static char *get_params(struct crypt_dm_active_device *dmd)
246 int r, max_size, null_cipher = 0;
247 char *params, *hexkey;
248 const char *features = "";
250 if (dmd->flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
251 if (dm_flags() & DM_DISCARDS_SUPPORTED) {
252 features = " 1 allow_discards";
253 log_dbg("Discard/TRIM is allowed.");
255 log_dbg("Discard/TRIM is not supported by the kernel.");
258 if (!strncmp(dmd->cipher, "cipher_null-", 12))
261 hexkey = crypt_safe_alloc(null_cipher ? 2 : (dmd->vk->keylength * 2 + 1));
266 strncpy(hexkey, "-", 2);
268 hex_key(hexkey, dmd->vk->keylength, dmd->vk->key);
270 max_size = strlen(hexkey) + strlen(dmd->cipher) +
271 strlen(dmd->device) + strlen(features) + 64;
272 params = crypt_safe_alloc(max_size);
276 r = snprintf(params, max_size, "%s %s %" PRIu64 " %s %" PRIu64 "%s",
277 dmd->cipher, hexkey, dmd->iv_offset, dmd->device,
278 dmd->offset, features);
279 if (r < 0 || r >= max_size) {
280 crypt_safe_free(params);
284 crypt_safe_free(hexkey);
289 static int _dm_simple(int task, const char *name, int udev_wait)
298 if (!(dmt = dm_task_create(task)))
301 if (name && !dm_task_set_name(dmt, name))
304 #if HAVE_DECL_DM_TASK_RETRY_REMOVE
305 /* Used only in DM_DEVICE_REMOVE */
306 if (name && !dm_task_retry_remove(dmt))
309 if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
312 r = dm_task_run(dmt);
315 (void)_dm_udev_wait(cookie);
318 dm_task_destroy(dmt);
322 static int _error_device(const char *name, size_t size)
327 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
330 if (!dm_task_set_name(dmt, name))
333 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
336 if (!dm_task_set_ro(dmt))
339 if (!dm_task_no_open_count(dmt))
342 if (!dm_task_run(dmt))
345 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
346 _dm_simple(DM_DEVICE_CLEAR, name, 0);
353 dm_task_destroy(dmt);
357 int dm_remove_device(const char *name, int force, uint64_t size)
360 int retries = force ? RETRY_COUNT : 1;
361 int error_target = 0;
363 if (!name || (force && !size))
367 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
368 if (--retries && r) {
369 log_dbg("WARNING: other process locked internal device %s, %s.",
370 name, retries ? "retrying remove" : "giving up");
371 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
372 debug_processes_using_device(name);
374 if (force && !error_target) {
375 /* If force flag is set, replace device with error, read-only target.
376 * it should stop processes from reading it and also removed underlying
377 * device from mapping, so it is usable again.
378 * Force flag should be used only for temporary devices, which are
379 * intended to work inside cryptsetup only!
380 * Anyway, if some process try to read temporary cryptsetup device,
381 * it is bug - no other process should try touch it (e.g. udev).
383 _error_device(name, size);
387 } while (r == -EINVAL && retries);
389 dm_task_update_nodes();
394 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
396 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
398 * CRYPT-LUKS1-00000000000000000000000000000000-name
401 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
403 char *ptr, uuid2[UUID_LEN] = {0};
407 /* Remove '-' chars */
408 if (uuid && !uuid_parse(uuid, uu)) {
409 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
410 if (uuid[i] != '-') {
416 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
417 type ?: "", type ? "-" : "",
418 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
421 log_dbg("DM-UUID is %s", buf);
423 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
426 int dm_create_device(const char *name,
428 struct crypt_dm_active_device *dmd,
431 struct dm_task *dmt = NULL;
434 char dev_uuid[DM_UUID_LEN] = {0};
436 uint32_t read_ahead = 0;
438 uint16_t udev_flags = 0;
440 params = get_params(dmd);
444 if (dmd->flags & CRYPT_ACTIVATE_PRIVATE)
445 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
447 /* All devices must have DM_UUID, only resize on old device is exception */
449 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
452 if (!dm_task_set_name(dmt, name))
455 dm_prepare_uuid(name, type, dmd->uuid, dev_uuid, sizeof(dev_uuid));
457 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
460 if (!dm_task_set_name(dmt, name))
463 if (!dm_task_set_uuid(dmt, dev_uuid))
466 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
470 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
472 if ((dmd->flags & CRYPT_ACTIVATE_READONLY) && !dm_task_set_ro(dmt))
474 if (!dm_task_add_target(dmt, 0, dmd->size, DM_CRYPT_TARGET, params))
477 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
478 if (device_read_ahead(dmd->device, &read_ahead) &&
479 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
483 if (!dm_task_run(dmt))
487 dm_task_destroy(dmt);
488 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
490 if (!dm_task_set_name(dmt, name))
492 if (dmd->uuid && !dm_task_set_uuid(dmt, dev_uuid))
494 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
496 if (!dm_task_run(dmt))
500 if (!dm_task_get_info(dmt, &dmi))
505 if (_dm_use_udev()) {
506 (void)_dm_udev_wait(cookie);
510 if (r < 0 && !reload)
511 dm_remove_device(name, 0, 0);
514 if (cookie && _dm_use_udev())
515 (void)_dm_udev_wait(cookie);
518 crypt_safe_free(params);
520 dm_task_destroy(dmt);
522 dm_task_update_nodes();
526 static int dm_status_dmi(const char *name, struct dm_info *dmi)
529 uint64_t start, length;
530 char *target_type, *params;
534 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
537 if (!dm_task_set_name(dmt, name))
540 if (!dm_task_run(dmt))
543 if (!dm_task_get_info(dmt, dmi))
551 next = dm_get_next_target(dmt, next, &start, &length,
552 &target_type, ¶ms);
553 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
560 dm_task_destroy(dmt);
565 int dm_status_device(const char *name)
570 r = dm_status_dmi(name, &dmi);
574 return (dmi.open_count > 0);
577 int dm_status_suspended(const char *name)
582 r = dm_status_dmi(name, &dmi);
586 return dmi.suspended ? 1 : 0;
589 int dm_query_device(const char *name, uint32_t get_flags,
590 struct crypt_dm_active_device *dmd)
594 uint64_t start, length, val64;
595 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *arg;
596 const char *tmp_uuid;
601 memset(dmd, 0, sizeof(*dmd));
603 if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
605 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
607 if (!dm_task_set_name(dmt, name))
610 if (!dm_task_run(dmt))
614 if (!dm_task_get_info(dmt, &dmi))
622 tmp_uuid = dm_task_get_uuid(dmt);
624 next = dm_get_next_target(dmt, next, &start, &length,
625 &target_type, ¶ms);
626 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
632 rcipher = strsep(¶ms, " ");
634 if (get_flags & DM_ACTIVE_CIPHER)
635 dmd->cipher = strdup(rcipher);
638 key_ = strsep(¶ms, " ");
641 val64 = strtoull(params, ¶ms, 10);
646 dmd->iv_offset = val64;
649 rdevice = strsep(¶ms, " ");
650 if (get_flags & DM_ACTIVE_DEVICE)
651 dmd->device = crypt_lookup_dev(rdevice);
656 val64 = strtoull(params, ¶ms, 10);
659 /* Features section, available since crypt target version 1.11 */
665 /* Number of arguments */
666 val64 = strtoull(params, ¶ms, 10);
671 for (i = 0; i < val64; i++) {
674 arg = strsep(¶ms, " ");
675 if (!strcasecmp(arg, "allow_discards"))
676 dmd->flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
677 else /* unknown option */
681 /* All parameters shold be processed */
686 /* Never allow to return empty key */
687 if ((get_flags & DM_ACTIVE_KEY) && dmi.suspended) {
688 log_dbg("Cannot read volume key while suspended.");
693 if (get_flags & DM_ACTIVE_KEYSIZE) {
694 dmd->vk = crypt_alloc_volume_key(strlen(key_) / 2, NULL);
700 if (get_flags & DM_ACTIVE_KEY) {
702 for(i = 0; i < dmd->vk->keylength; i++) {
703 memcpy(buffer, &key_[i * 2], 2);
704 dmd->vk->key[i] = strtoul(buffer, &endp, 16);
705 if (endp != &buffer[2]) {
706 crypt_free_volume_key(dmd->vk);
714 memset(key_, 0, strlen(key_));
717 dmd->flags |= CRYPT_ACTIVATE_READONLY;
720 dmd->flags |= CRYPT_ACTIVATE_NO_UUID;
721 else if (get_flags & DM_ACTIVE_UUID) {
722 if (!strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
723 dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
726 r = (dmi.open_count > 0);
729 dm_task_destroy(dmt);
734 static int _dm_message(const char *name, const char *msg)
739 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
742 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
745 if (name && !dm_task_set_name(dmt, name))
748 if (!dm_task_set_sector(dmt, (uint64_t) 0))
751 if (!dm_task_set_message(dmt, msg))
754 r = dm_task_run(dmt);
757 dm_task_destroy(dmt);
761 int dm_suspend_and_wipe_key(const char *name)
763 if (!_dm_check_versions())
766 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
769 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
772 if (!_dm_message(name, "key wipe")) {
773 _dm_simple(DM_DEVICE_RESUME, name, 1);
780 int dm_resume_and_reinstate_key(const char *name,
784 int msg_size = key_size * 2 + 10; // key set <key>
788 if (!_dm_check_versions())
791 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
794 msg = crypt_safe_alloc(msg_size);
798 memset(msg, 0, msg_size);
799 strcpy(msg, "key set ");
800 hex_key(&msg[8], key_size, key);
802 if (!_dm_message(name, msg) ||
803 !_dm_simple(DM_DEVICE_RESUME, name, 1))
806 crypt_safe_free(msg);
810 const char *dm_get_dir(void)
815 int dm_is_dm_device(int major, int minor)
817 return dm_is_dm_major((uint32_t)major);
820 int dm_is_dm_kernel_name(const char *name)
822 return strncmp(name, "dm-", 3) ? 0 : 1;
825 int dm_check_segment(const char *name, uint64_t offset, uint64_t size)
827 struct crypt_dm_active_device dmd;
830 log_dbg("Checking segments for device %s.", name);
832 r = dm_query_device(name, 0, &dmd);
836 if (offset >= (dmd.offset + dmd.size) || (offset + size) <= dmd.offset)
841 log_dbg("seg: %" PRIu64 " - %" PRIu64 ", new %" PRIu64 " - %" PRIu64 "%s",
842 dmd.offset, dmd.offset + dmd.size, offset, offset + size,
843 r ? " (overlapping)" : " (ok)");