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) 2009-2011, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 /* Repeat test if dm-crypt is not present */
124 _dm_crypt_checked = 1;
127 static int _dm_check_versions(void)
130 struct dm_versions *target, *last_target;
133 if (_dm_crypt_checked)
136 /* FIXME: add support to DM so it forces crypt target module load here */
137 if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
140 if (!dm_task_run(dmt)) {
141 dm_task_destroy(dmt);
145 if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
146 dm_task_destroy(dmt);
150 target = dm_task_get_versions(dmt);
152 last_target = target;
153 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
154 _dm_set_crypt_compat(dm_version,
155 (unsigned)target->version[0],
156 (unsigned)target->version[1],
157 (unsigned)target->version[2]);
159 target = (struct dm_versions *)((char *) target + target->next);
160 } while (last_target != target);
162 dm_task_destroy(dmt);
166 uint32_t dm_flags(void)
168 if (!_dm_crypt_checked)
169 _dm_check_versions();
171 return _dm_crypt_flags;
174 int dm_init(struct crypt_device *context, int check_kernel)
176 if (!_dm_use_count++) {
177 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
178 check_kernel ? "" : " (NO kernel check requested)",
179 _dm_use_udev() ? "en" : "dis");
180 if (check_kernel && !_dm_check_versions()) {
181 log_err(context, _("Cannot initialize device-mapper. Is dm_mod kernel module loaded?\n"));
184 if (getuid() || geteuid())
185 log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
186 dm_log_init(set_dm_error);
187 dm_log_init_verbose(10);
190 // FIXME: global context is not safe
194 return 1; /* unsafe memory */
199 if (_dm_use_count && (!--_dm_use_count)) {
200 log_dbg("Releasing device-mapper backend.");
201 dm_log_init_verbose(0);
208 /* Return path to DM device */
209 char *dm_device_path(int major, int minor)
215 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
217 if (!dm_task_set_minor(dmt, minor) ||
218 !dm_task_set_major(dmt, major) ||
220 !(name = dm_task_get_name(dmt))) {
221 dm_task_destroy(dmt);
225 if (snprintf(path, sizeof(path), "/dev/mapper/%s", name) < 0)
228 dm_task_destroy(dmt);
233 static void hex_key(char *hexkey, size_t key_size, const char *key)
237 for(i = 0; i < key_size; i++)
238 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
241 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
242 const char *cipher, size_t key_size, const char *key)
247 hexkey = crypt_safe_alloc(key_size * 2 + 1);
251 hex_key(hexkey, key_size, key);
253 params = crypt_safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
257 sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
258 cipher, hexkey, skip, device, offset);
261 crypt_safe_free(hexkey);
266 static int _dm_simple(int task, const char *name, int udev_wait)
275 if (!(dmt = dm_task_create(task)))
278 if (name && !dm_task_set_name(dmt, name))
281 if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
284 r = dm_task_run(dmt);
287 (void)_dm_udev_wait(cookie);
290 dm_task_destroy(dmt);
294 static int _error_device(const char *name, size_t size)
299 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
302 if (!dm_task_set_name(dmt, name))
305 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
308 if (!dm_task_set_ro(dmt))
311 if (!dm_task_no_open_count(dmt))
314 if (!dm_task_run(dmt))
317 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
318 _dm_simple(DM_DEVICE_CLEAR, name, 0);
325 dm_task_destroy(dmt);
329 int dm_remove_device(const char *name, int force, uint64_t size)
332 int retries = force ? RETRY_COUNT : 1;
333 int error_target = 0;
335 if (!name || (force && !size))
339 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
340 if (--retries && r) {
341 log_dbg("WARNING: other process locked internal device %s, %s.",
342 name, retries ? "retrying remove" : "giving up");
343 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
344 debug_processes_using_device(name);
346 if (force && !error_target) {
347 /* If force flag is set, replace device with error, read-only target.
348 * it should stop processes from reading it and also removed underlying
349 * device from mapping, so it is usable again.
350 * Force flag should be used only for temporary devices, which are
351 * intended to work inside cryptsetup only!
352 * Anyway, if some process try to read temporary cryptsetup device,
353 * it is bug - no other process should try touch it (e.g. udev).
355 _error_device(name, size);
359 } while (r == -EINVAL && retries);
361 dm_task_update_nodes();
366 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
368 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
370 * CRYPT-LUKS1-00000000000000000000000000000000-name
373 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
375 char *ptr, uuid2[UUID_LEN] = {0};
379 /* Remove '-' chars */
380 if (uuid && !uuid_parse(uuid, uu)) {
381 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
382 if (uuid[i] != '-') {
388 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
389 type ?: "", type ? "-" : "",
390 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
393 log_dbg("DM-UUID is %s", buf);
395 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
398 int dm_create_device(const char *name,
411 struct dm_task *dmt = NULL;
415 char dev_uuid[DM_UUID_LEN] = {0};
417 uint32_t read_ahead = 0;
419 uint16_t udev_flags = 0;
421 params = get_params(device, skip, offset, cipher, key_size, key);
425 if (type && !strncmp(type, "TEMP", 4))
426 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
428 /* All devices must have DM_UUID, only resize on old device is exception */
430 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
433 if (!dm_task_set_name(dmt, name))
436 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
438 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
441 if (!dm_task_set_name(dmt, name))
444 if (!dm_task_set_uuid(dmt, dev_uuid))
447 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
451 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
453 if (read_only && !dm_task_set_ro(dmt))
455 if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
458 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
459 if (device_read_ahead(device, &read_ahead) &&
460 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
464 if (!dm_task_run(dmt))
468 dm_task_destroy(dmt);
469 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
471 if (!dm_task_set_name(dmt, name))
473 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
475 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
477 if (!dm_task_run(dmt))
481 if (!dm_task_get_info(dmt, &dmi))
486 if (_dm_use_udev()) {
487 (void)_dm_udev_wait(cookie);
491 if (r < 0 && !reload) {
493 error = strdup(get_error());
495 dm_remove_device(name, 0, 0);
504 if (cookie && _dm_use_udev())
505 (void)_dm_udev_wait(cookie);
508 crypt_safe_free(params);
510 dm_task_destroy(dmt);
512 dm_task_update_nodes();
516 int dm_status_device(const char *name)
520 uint64_t start, length;
521 char *target_type, *params;
525 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
528 if (!dm_task_set_name(dmt, name))
531 if (!dm_task_run(dmt))
534 if (!dm_task_get_info(dmt, &dmi))
542 next = dm_get_next_target(dmt, next, &start, &length,
543 &target_type, ¶ms);
544 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
548 r = (dmi.open_count > 0);
551 dm_task_destroy(dmt);
556 int dm_query_device(const char *name,
570 uint64_t start, length, val64;
571 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3];
572 const char *tmp_uuid;
576 if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
578 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
580 if (!dm_task_set_name(dmt, name))
583 if (!dm_task_run(dmt))
587 if (!dm_task_get_info(dmt, &dmi))
595 next = dm_get_next_target(dmt, next, &start, &length,
596 &target_type, ¶ms);
597 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
604 rcipher = strsep(¶ms, " ");
607 *cipher = strdup(rcipher);
610 key_ = strsep(¶ms, " ");
613 val64 = strtoull(params, ¶ms, 10);
621 rdevice = strsep(¶ms, " ");
623 *device = crypt_lookup_dev(rdevice);
628 val64 = strtoull(params, ¶ms, 10);
636 *key_size = strlen(key_) / 2;
639 if (key_size && key) {
640 *key = crypt_safe_alloc(*key_size);
647 for(i = 0; i < *key_size; i++) {
648 memcpy(buffer, &key_[i * 2], 2);
649 (*key)[i] = strtoul(buffer, &endp, 16);
650 if (endp != &buffer[2]) {
651 crypt_safe_free(key);
657 memset(key_, 0, strlen(key_));
660 *read_only = dmi.read_only;
663 *suspended = dmi.suspended;
665 if (uuid && (tmp_uuid = dm_task_get_uuid(dmt)) &&
666 !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
667 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
669 r = (dmi.open_count > 0);
672 dm_task_destroy(dmt);
677 static int _dm_message(const char *name, const char *msg)
682 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
685 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
688 if (name && !dm_task_set_name(dmt, name))
691 if (!dm_task_set_sector(dmt, (uint64_t) 0))
694 if (!dm_task_set_message(dmt, msg))
697 r = dm_task_run(dmt);
700 dm_task_destroy(dmt);
704 int dm_suspend_and_wipe_key(const char *name)
706 if (!_dm_check_versions())
709 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
712 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
715 if (!_dm_message(name, "key wipe")) {
716 _dm_simple(DM_DEVICE_RESUME, name, 1);
723 int dm_resume_and_reinstate_key(const char *name,
727 int msg_size = key_size * 2 + 10; // key set <key>
731 if (!_dm_check_versions())
734 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
737 msg = crypt_safe_alloc(msg_size);
741 memset(msg, 0, msg_size);
742 strcpy(msg, "key set ");
743 hex_key(&msg[8], key_size, key);
745 if (!_dm_message(name, msg) ||
746 !_dm_simple(DM_DEVICE_RESUME, name, 1))
749 crypt_safe_free(msg);
753 const char *dm_get_dir(void)
758 int dm_is_dm_device(int major, int minor)
760 return dm_is_dm_major((uint32_t)major);
763 int dm_is_dm_kernel_name(const char *name)
765 return strncmp(name, "dm-", 3) ? 0 : 1;