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(void)
69 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
70 return dm_udev_get_sync_support();
76 __attribute__((format(printf, 4, 5)))
77 static void set_dm_error(int level,
78 const char *file __attribute__((unused)),
79 int line __attribute__((unused)),
86 if (vasprintf(&msg, f, va) > 0) {
88 log_err(_context, msg);
89 log_err(_context, "\n");
97 static int _dm_simple(int task, const char *name, int udev_wait);
99 static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
100 unsigned crypt_min, unsigned crypt_patch)
102 unsigned dm_maj, dm_min, dm_patch;
104 if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
105 dm_maj = dm_min = dm_patch = 0;
107 log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
108 crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
110 if (crypt_maj >= 1 && crypt_min >= 2)
111 _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
113 log_dbg("Suspend and resume disabled, no wipe key support.");
115 if (crypt_maj >= 1 && crypt_min >= 10)
116 _dm_crypt_flags |= DM_LMK_SUPPORTED;
118 if (dm_maj >= 4 && dm_min >= 20)
119 _dm_crypt_flags |= DM_SECURE_SUPPORTED;
121 /* not perfect, 2.6.33 supports with 1.7.0 */
122 if (crypt_maj >= 1 && crypt_min >= 8)
123 _dm_crypt_flags |= DM_PLAIN64_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 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level)
213 struct dirent *entry;
220 /* Ignore strange nested directories */
221 if (dir_level > max_level)
224 path[PATH_MAX - 1] = '\0';
225 ptr = path + strlen(path);
228 space = PATH_MAX - (ptr - path);
234 while((entry = readdir(dir))) {
235 if (entry->d_name[0] == '.' ||
236 !strncmp(entry->d_name, "..", 2))
239 strncpy(ptr, entry->d_name, space);
240 if (stat(path, &st) < 0)
243 if (S_ISDIR(st.st_mode)) {
244 result = __lookup_dev(path, dev, dir_level + 1, max_level);
247 } else if (S_ISBLK(st.st_mode)) {
248 /* workaround: ignore dm-X devices, these are internal kernel names */
249 if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3))
251 if (st.st_rdev == dev) {
252 result = strdup(path);
262 static char *lookup_dev(const char *dev_id)
264 uint32_t major, minor;
266 char *result = NULL, buf[PATH_MAX + 1];
268 if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
271 dev = makedev(major, minor);
272 strncpy(buf, DEVICE_DIR, PATH_MAX);
273 buf[PATH_MAX] = '\0';
275 /* First try low level device */
276 if ((result = __lookup_dev(buf, dev, 0, 0)))
279 /* If it is dm, try DM dir */
280 if (dm_is_dm_major(major)) {
281 strncpy(buf, dm_dir(), PATH_MAX);
282 if ((result = __lookup_dev(buf, dev, 0, 0)))
286 strncpy(buf, DEVICE_DIR, PATH_MAX);
287 result = __lookup_dev(buf, dev, 0, 4);
289 /* If not found, return NULL */
293 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead)
296 long read_ahead_long;
298 if ((fd = open(dev, O_RDONLY)) < 0)
301 r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1;
305 *read_ahead = (uint32_t) read_ahead_long;
310 static void hex_key(char *hexkey, size_t key_size, const char *key)
314 for(i = 0; i < key_size; i++)
315 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
318 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
319 const char *cipher, size_t key_size, const char *key)
324 hexkey = crypt_safe_alloc(key_size * 2 + 1);
328 hex_key(hexkey, key_size, key);
330 params = crypt_safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
334 sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
335 cipher, hexkey, skip, device, offset);
338 crypt_safe_free(hexkey);
343 static int _dm_simple(int task, const char *name, int udev_wait)
352 if (!(dmt = dm_task_create(task)))
355 if (name && !dm_task_set_name(dmt, name))
358 if (udev_wait && !_dm_task_set_cookie(dmt, &cookie, 0))
361 r = dm_task_run(dmt);
364 (void)_dm_udev_wait(cookie);
367 dm_task_destroy(dmt);
371 static int _error_device(const char *name, size_t size)
376 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
379 if (!dm_task_set_name(dmt, name))
382 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
385 if (!dm_task_set_ro(dmt))
388 if (!dm_task_no_open_count(dmt))
391 if (!dm_task_run(dmt))
394 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
395 _dm_simple(DM_DEVICE_CLEAR, name, 0);
402 dm_task_destroy(dmt);
406 int dm_remove_device(const char *name, int force, uint64_t size)
409 int retries = force ? RETRY_COUNT : 1;
410 int error_target = 0;
412 if (!name || (force && !size))
416 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
417 if (--retries && r) {
418 log_dbg("WARNING: other process locked internal device %s, %s.",
419 name, retries ? "retrying remove" : "giving up");
420 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
421 debug_processes_using_device(name);
423 if (force && !error_target) {
424 /* If force flag is set, replace device with error, read-only target.
425 * it should stop processes from reading it and also removed underlying
426 * device from mapping, so it is usable again.
427 * Force flag should be used only for temporary devices, which are
428 * intended to work inside cryptsetup only!
429 * Anyway, if some process try to read temporary cryptsetup device,
430 * it is bug - no other process should try touch it (e.g. udev).
432 _error_device(name, size);
436 } while (r == -EINVAL && retries);
438 dm_task_update_nodes();
443 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
445 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
447 * CRYPT-LUKS1-00000000000000000000000000000000-name
450 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
452 char *ptr, uuid2[UUID_LEN] = {0};
456 /* Remove '-' chars */
457 if (uuid && !uuid_parse(uuid, uu)) {
458 for (ptr = uuid2, i = 0; i < UUID_LEN; i++)
459 if (uuid[i] != '-') {
465 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
466 type ?: "", type ? "-" : "",
467 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
470 log_dbg("DM-UUID is %s", buf);
472 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
475 int dm_create_device(const char *name,
488 struct dm_task *dmt = NULL;
492 char dev_uuid[DM_UUID_LEN] = {0};
494 uint32_t read_ahead = 0;
496 uint16_t udev_flags = 0;
498 params = get_params(device, skip, offset, cipher, key_size, key);
502 if (type && !strncmp(type, "TEMP", 4))
503 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
505 /* All devices must have DM_UUID, only resize on old device is exception */
507 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
510 if (!dm_task_set_name(dmt, name))
513 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
515 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
518 if (!dm_task_set_name(dmt, name))
521 if (!dm_task_set_uuid(dmt, dev_uuid))
524 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
528 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
530 if (read_only && !dm_task_set_ro(dmt))
532 if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
535 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
536 if (_dev_read_ahead(device, &read_ahead) &&
537 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
541 if (!dm_task_run(dmt))
545 dm_task_destroy(dmt);
546 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
548 if (!dm_task_set_name(dmt, name))
550 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
552 if (_dm_use_udev() && !_dm_task_set_cookie(dmt, &cookie, udev_flags))
554 if (!dm_task_run(dmt))
558 if (!dm_task_get_info(dmt, &dmi))
563 if (_dm_use_udev()) {
564 (void)_dm_udev_wait(cookie);
568 if (r < 0 && !reload) {
570 error = strdup(get_error());
572 dm_remove_device(name, 0, 0);
581 if (cookie && _dm_use_udev())
582 (void)_dm_udev_wait(cookie);
585 crypt_safe_free(params);
587 dm_task_destroy(dmt);
589 dm_task_update_nodes();
593 int dm_status_device(const char *name)
597 uint64_t start, length;
598 char *target_type, *params;
602 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
605 if (!dm_task_set_name(dmt, name))
608 if (!dm_task_run(dmt))
611 if (!dm_task_get_info(dmt, &dmi))
619 next = dm_get_next_target(dmt, next, &start, &length,
620 &target_type, ¶ms);
621 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
625 r = (dmi.open_count > 0);
628 dm_task_destroy(dmt);
633 int dm_query_device(const char *name,
647 uint64_t start, length, val64;
648 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3];
649 const char *tmp_uuid;
653 if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
655 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
657 if (!dm_task_set_name(dmt, name))
660 if (!dm_task_run(dmt))
664 if (!dm_task_get_info(dmt, &dmi))
672 next = dm_get_next_target(dmt, next, &start, &length,
673 &target_type, ¶ms);
674 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
681 rcipher = strsep(¶ms, " ");
684 *cipher = strdup(rcipher);
687 key_ = strsep(¶ms, " ");
690 val64 = strtoull(params, ¶ms, 10);
698 rdevice = strsep(¶ms, " ");
700 *device = lookup_dev(rdevice);
705 val64 = strtoull(params, ¶ms, 10);
713 *key_size = strlen(key_) / 2;
716 if (key_size && key) {
717 *key = crypt_safe_alloc(*key_size);
724 for(i = 0; i < *key_size; i++) {
725 memcpy(buffer, &key_[i * 2], 2);
726 (*key)[i] = strtoul(buffer, &endp, 16);
727 if (endp != &buffer[2]) {
728 crypt_safe_free(key);
734 memset(key_, 0, strlen(key_));
737 *read_only = dmi.read_only;
740 *suspended = dmi.suspended;
742 if (uuid && (tmp_uuid = dm_task_get_uuid(dmt)) &&
743 !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
744 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
746 r = (dmi.open_count > 0);
749 dm_task_destroy(dmt);
754 static int _dm_message(const char *name, const char *msg)
759 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
762 if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
765 if (name && !dm_task_set_name(dmt, name))
768 if (!dm_task_set_sector(dmt, (uint64_t) 0))
771 if (!dm_task_set_message(dmt, msg))
774 r = dm_task_run(dmt);
777 dm_task_destroy(dmt);
781 int dm_suspend_and_wipe_key(const char *name)
783 if (!_dm_check_versions())
786 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
789 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
792 if (!_dm_message(name, "key wipe")) {
793 _dm_simple(DM_DEVICE_RESUME, name, 1);
800 int dm_resume_and_reinstate_key(const char *name,
804 int msg_size = key_size * 2 + 10; // key set <key>
808 if (!_dm_check_versions())
811 if (!(_dm_crypt_flags & DM_KEY_WIPE_SUPPORTED))
814 msg = crypt_safe_alloc(msg_size);
818 memset(msg, 0, msg_size);
819 strcpy(msg, "key set ");
820 hex_key(&msg[8], key_size, key);
822 if (!_dm_message(name, msg) ||
823 !_dm_simple(DM_DEVICE_RESUME, name, 1))
826 crypt_safe_free(msg);
830 const char *dm_get_dir(void)