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
22 #include <sys/ioctl.h>
27 #include <libdevmapper.h>
30 #include <uuid/uuid.h>
35 #define DEVICE_DIR "/dev"
36 #define DM_UUID_LEN 129
37 #define DM_UUID_PREFIX "CRYPT-"
38 #define DM_UUID_PREFIX_LEN 6
39 #define DM_CRYPT_TARGET "crypt"
42 /* Set if dm-crypt version was probed */
43 static int _dm_crypt_checked = 0;
44 static uint32_t _dm_crypt_flags = 0;
46 static int _dm_use_count = 0;
47 static struct crypt_device *_context = NULL;
49 /* Check if we have DM flag to instruct kernel to force wipe buffers */
50 #if !HAVE_DECL_DM_TASK_SECURE_DATA
51 static int dm_task_secure_data(struct dm_task *dmt) { return 1; }
54 /* Compatibility for old device-mapper without udev support */
55 #if HAVE_DECL_DM_UDEV_DISABLE_DISK_RULES_FLAG
56 #define CRYPT_TEMP_UDEV_FLAGS DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
57 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
58 DM_UDEV_DISABLE_OTHER_RULES_FLAG
59 #define _dm_task_set_cookie dm_task_set_cookie
60 #define _dm_udev_wait dm_udev_wait
62 #define CRYPT_TEMP_UDEV_FLAGS 0
63 static int _dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags) { return 0; }
64 static int _dm_udev_wait(uint32_t cookie) { return 0; };
67 static int _dm_use_udev()
69 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
70 return dm_udev_get_sync_support();
76 static void set_dm_error(int level, const char *file, int line,
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 = (void *) 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 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level)
210 struct dirent *entry;
217 /* Ignore strange nested directories */
218 if (dir_level > max_level)
221 path[PATH_MAX - 1] = '\0';
222 ptr = path + strlen(path);
225 space = PATH_MAX - (ptr - path);
231 while((entry = readdir(dir))) {
232 if (entry->d_name[0] == '.' ||
233 !strncmp(entry->d_name, "..", 2))
236 strncpy(ptr, entry->d_name, space);
237 if (stat(path, &st) < 0)
240 if (S_ISDIR(st.st_mode)) {
241 result = __lookup_dev(path, dev, dir_level + 1, max_level);
244 } else if (S_ISBLK(st.st_mode)) {
245 /* workaround: ignore dm-X devices, these are internal kernel names */
246 if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3))
248 if (st.st_rdev == dev) {
249 result = strdup(path);
259 static char *lookup_dev(const char *dev_id)
261 uint32_t major, minor;
263 char *result = NULL, buf[PATH_MAX + 1];
265 if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
268 dev = makedev(major, minor);
269 strncpy(buf, DEVICE_DIR, PATH_MAX);
270 buf[PATH_MAX] = '\0';
272 /* First try low level device */
273 if ((result = __lookup_dev(buf, dev, 0, 0)))
276 /* If it is dm, try DM dir */
277 if (dm_is_dm_major(major)) {
278 strncpy(buf, dm_dir(), PATH_MAX);
279 if ((result = __lookup_dev(buf, dev, 0, 0)))
283 strncpy(buf, DEVICE_DIR, PATH_MAX);
284 result = __lookup_dev(buf, dev, 0, 4);
286 /* If not found, return NULL */
290 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead)
293 long read_ahead_long;
295 if ((fd = open(dev, O_RDONLY)) < 0)
298 r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1;
302 *read_ahead = (uint32_t) read_ahead_long;
307 static void hex_key(char *hexkey, size_t key_size, const char *key)
311 for(i = 0; i < key_size; i++)
312 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
315 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
316 const char *cipher, size_t key_size, const char *key)
321 hexkey = crypt_safe_alloc(key_size * 2 + 1);
325 hex_key(hexkey, key_size, key);
327 params = crypt_safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
331 sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
332 cipher, hexkey, skip, device, offset);
335 crypt_safe_free(hexkey);
340 static int _dm_simple(int task, const char *name, int udev_wait)
349 if (!(dmt = dm_task_create(task)))
352 if (name && !dm_task_set_name(dmt, name))
355 if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
358 r = dm_task_run(dmt);
361 (void)_dm_udev_wait(cookie);
364 dm_task_destroy(dmt);
368 static int _error_device(const char *name, size_t size)
373 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
376 if (!dm_task_set_name(dmt, name))
379 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
382 if (!dm_task_set_ro(dmt))
385 if (!dm_task_no_open_count(dmt))
388 if (!dm_task_run(dmt))
391 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
392 _dm_simple(DM_DEVICE_CLEAR, name, 0);
399 dm_task_destroy(dmt);
403 int dm_remove_device(const char *name, int force, uint64_t size)
406 int retries = force ? RETRY_COUNT : 1;
407 int error_target = 0;
409 if (!name || (force && !size))
413 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
414 if (--retries && r) {
415 log_dbg("WARNING: other process locked internal device %s, %s.",
416 name, retries ? "retrying remove" : "giving up");
417 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
418 debug_processes_using_device(name);
420 if (force && !error_target) {
421 /* If force flag is set, replace device with error, read-only target.
422 * it should stop processes from reading it and also removed underlying
423 * device from mapping, so it is usable again.
424 * Force flag should be used only for temporary devices, which are
425 * intended to work inside cryptsetup only!
426 * Anyway, if some process try to read temporary cryptsetup device,
427 * it is bug - no other process should try touch it (e.g. udev).
429 _error_device(name, size);
433 } while (r == -EINVAL && retries);
435 dm_task_update_nodes();
440 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
442 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
444 * CRYPT-LUKS1-00000000000000000000000000000000-name
447 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
449 char *ptr, uuid2[UUID_LEN] = {0};
453 /* Remove '-' chars */
454 if (uuid && !uuid_parse(uuid, uu)) {
455 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
456 if (uuid[i] != '-') {
462 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
463 type ?: "", type ? "-" : "",
464 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
467 log_dbg("DM-UUID is %s", buf);
469 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
472 int dm_create_device(const char *name,
485 struct dm_task *dmt = NULL;
489 char dev_uuid[DM_UUID_LEN] = {0};
491 uint32_t read_ahead = 0;
493 uint16_t udev_flags = 0;
495 params = get_params(device, skip, offset, cipher, key_size, key);
499 if (type && !strncmp(type, "TEMP", 4))
500 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
502 /* All devices must have DM_UUID, only resize on old device is exception */
504 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
507 if (!dm_task_set_name(dmt, name))
510 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
512 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
515 if (!dm_task_set_name(dmt, name))
518 if (!dm_task_set_uuid(dmt, dev_uuid))
521 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
525 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
527 if (read_only && !dm_task_set_ro(dmt))
529 if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
532 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
533 if (_dev_read_ahead(device, &read_ahead) &&
534 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
538 if (!dm_task_run(dmt))
542 dm_task_destroy(dmt);
543 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
545 if (!dm_task_set_name(dmt, name))
547 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
549 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
551 if (!dm_task_run(dmt))
555 if (!dm_task_get_info(dmt, &dmi))
560 if (_dm_use_udev()) {
561 (void)_dm_udev_wait(cookie);
565 if (r < 0 && !reload) {
567 error = strdup(get_error());
569 dm_remove_device(name, 0, 0);
578 if (cookie && _dm_use_udev())
579 (void)_dm_udev_wait(cookie);
582 crypt_safe_free(params);
584 dm_task_destroy(dmt);
586 dm_task_update_nodes();
590 int dm_status_device(const char *name)
594 uint64_t start, length;
595 char *target_type, *params;
599 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
602 if (!dm_task_set_name(dmt, name))
605 if (!dm_task_run(dmt))
608 if (!dm_task_get_info(dmt, &dmi))
616 next = dm_get_next_target(dmt, next, &start, &length,
617 &target_type, ¶ms);
618 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
622 r = (dmi.open_count > 0);
625 dm_task_destroy(dmt);
630 int dm_query_device(const char *name,
644 uint64_t start, length, val64;
645 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *tmp_uuid;
649 if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
651 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
653 if (!dm_task_set_name(dmt, name))
656 if (!dm_task_run(dmt))
660 if (!dm_task_get_info(dmt, &dmi))
668 next = dm_get_next_target(dmt, next, &start, &length,
669 &target_type, ¶ms);
670 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
677 rcipher = strsep(¶ms, " ");
680 *cipher = strdup(rcipher);
683 key_ = strsep(¶ms, " ");
686 val64 = strtoull(params, ¶ms, 10);
694 rdevice = strsep(¶ms, " ");
696 *device = lookup_dev(rdevice);
701 val64 = strtoull(params, ¶ms, 10);
709 *key_size = strlen(key_) / 2;
712 if (key_size && key) {
713 *key = crypt_safe_alloc(*key_size);
720 for(i = 0; i < *key_size; i++) {
721 memcpy(buffer, &key_[i * 2], 2);
722 (*key)[i] = strtoul(buffer, &endp, 16);
723 if (endp != &buffer[2]) {
724 crypt_safe_free(key);
730 memset(key_, 0, strlen(key_));
733 *read_only = dmi.read_only;
736 *suspended = dmi.suspended;
738 if (uuid && (tmp_uuid = (char*)dm_task_get_uuid(dmt)) &&
739 !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
740 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
742 r = (dmi.open_count > 0);
745 dm_task_destroy(dmt);
750 static int _dm_message(const char *name, const char *msg)
755 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
758 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
761 if (name && !dm_task_set_name(dmt, name))
764 if (!dm_task_set_sector(dmt, (uint64_t) 0))
767 if (!dm_task_set_message(dmt, msg))
770 r = dm_task_run(dmt);
773 dm_task_destroy(dmt);
777 int dm_suspend_and_wipe_key(const char *name)
779 if (!_dm_check_versions())
782 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
785 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
788 if (!_dm_message(name, "key wipe")) {
789 _dm_simple(DM_DEVICE_RESUME, name, 1);
796 int dm_resume_and_reinstate_key(const char *name,
800 int msg_size = key_size * 2 + 10; // key set <key>
804 if (!_dm_check_versions())
807 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
810 msg = crypt_safe_alloc(msg_size);
814 memset(msg, 0, msg_size);
815 strcpy(msg, "key set ");
816 hex_key(&msg[8], key_size, key);
818 if (!_dm_message(name, msg) ||
819 !_dm_simple(DM_DEVICE_RESUME, name, 1))
822 crypt_safe_free(msg);
826 const char *dm_get_dir(void)