1 #include <machine/inttypes.h>
2 #include <sys/ioctl.h>
3 #include <sys/param.h>
4 #include <sys/stat.h>
5 #include <stdio.h>
6 #include <string.h>
7 #include <stdlib.h>
8 #include <dirent.h>
9 #include <errno.h>
10 #include <libdm.h>
11 #include <fcntl.h>
12 #include <uuid.h>
13
14 #include "internal.h"
15 #include "luks.h"
16
17 #define DEVICE_DIR "/dev"
18 #define DM_UUID_LEN 129
19 #define DM_UUID_PREFIX "CRYPT-"
20 #define DM_UUID_PREFIX_LEN 6
21 #define DM_CRYPT_TARGET "crypt"
22 #define RETRY_COUNT 5
23
24 /* Set if dm-crypt version was probed */
25 static int _dm_crypt_checked = 0;
26 static int _dm_crypt_wipe_key_supported = 0;
27
28 static int _dm_use_count = 0;
29 static struct crypt_device *_context = NULL;
30
31 /* Compatibility for old device-mapper without udev support */
32 #ifndef HAVE_DM_TASK_SET_COOKIE
33 #define CRYPT_TEMP_UDEV_FLAGS 0
34 #else
35 #define CRYPT_TEMP_UDEV_FLAGS DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG | \
36 DM_UDEV_DISABLE_DISK_RULES_FLAG | \
37 DM_UDEV_DISABLE_OTHER_RULES_FLAG
38 #endif
39
_dm_use_udev()40 static int _dm_use_udev()
41 {
42 #ifdef USE_UDEV /* cannot be enabled if devmapper is too old */
43 return dm_udev_get_sync_support();
44 #else
45 return 0;
46 #endif
47 }
48
set_dm_error(int level,const char * file,int line,const char * f,...)49 static void set_dm_error(int level, const char *file, int line,
50 const char *f, ...)
51 {
52 char *msg = NULL;
53 va_list va;
54
55 va_start(va, f);
56 if (vasprintf(&msg, f, va) > 0) {
57 if (level < 4) {
58 log_err(_context, msg);
59 log_err(_context, "\n");
60 } else
61 log_dbg(msg);
62 }
63 free(msg);
64 va_end(va);
65 }
66
67 static int _dm_simple(int task, const char *name, int udev_wait);
68
_dm_set_crypt_compat(int maj,int min,int patch)69 static void _dm_set_crypt_compat(int maj, int min, int patch)
70 {
71 log_dbg("Detected dm-crypt target of version %i.%i.%i.", maj, min, patch);
72
73 if (maj >= 1 && min >=2)
74 _dm_crypt_wipe_key_supported = 1;
75 else
76 log_dbg("Suspend and resume disabled, no wipe key support.");
77
78 _dm_crypt_checked = 1;
79 }
80
_dm_check_versions(void)81 static int _dm_check_versions(void)
82 {
83 struct dm_task *dmt;
84 struct dm_versions *target, *last_target;
85
86 if (_dm_crypt_checked)
87 return 1;
88
89 if (!(dmt = dm_task_create(DM_DEVICE_LIST_VERSIONS)))
90 return 0;
91
92 if (!dm_task_run(dmt)) {
93 dm_task_destroy(dmt);
94 return 0;
95 }
96
97 target = dm_task_get_versions(dmt);
98 do {
99 last_target = target;
100 if (!strcmp(DM_CRYPT_TARGET, target->name)) {
101 _dm_set_crypt_compat((int)target->version[0],
102 (int)target->version[1],
103 (int)target->version[2]);
104 }
105 target = (void *) target + target->next;
106 } while (last_target != target);
107
108 dm_task_destroy(dmt);
109 return 1;
110 }
111
dm_init(struct crypt_device * context,int check_kernel)112 int dm_init(struct crypt_device *context, int check_kernel)
113 {
114 if (!_dm_use_count++) {
115 log_dbg("Initialising device-mapper backend%s, UDEV is %sabled.",
116 check_kernel ? "" : " (NO kernel check requested)",
117 _dm_use_udev() ? "en" : "dis");
118 if (check_kernel && !_dm_check_versions()) {
119 log_err(context, _("Cannot initialize device-mapper. Is dm kernel module loaded?\n"));
120 return -1;
121 }
122 if (getuid() || geteuid())
123 log_dbg(("WARNING: Running as a non-root user. Functionality may be unavailable."));
124 dm_log_init(set_dm_error);
125 dm_log_init_verbose(10);
126 }
127
128 // FIXME: global context is not safe
129 if (context)
130 _context = context;
131
132 return 1; /* unsafe memory */
133 }
134
dm_exit(void)135 void dm_exit(void)
136 {
137 if (_dm_use_count && (!--_dm_use_count)) {
138 log_dbg("Releasing device-mapper backend.");
139 dm_log_init_verbose(0);
140 dm_log_init(NULL);
141 dm_lib_release();
142 _context = NULL;
143 }
144 }
145
__lookup_dev(char * path,dev_t dev,int dir_level,const int max_level)146 static char *__lookup_dev(char *path, dev_t dev, int dir_level, const int max_level)
147 {
148 struct dirent *entry;
149 struct stat st;
150 char *ptr;
151 char *result = NULL;
152 DIR *dir;
153 int space;
154
155 /* Ignore strange nested directories */
156 if (dir_level > max_level)
157 return NULL;
158
159 path[PATH_MAX - 1] = '\0';
160 ptr = path + strlen(path);
161 *ptr++ = '/';
162 *ptr = '\0';
163 space = PATH_MAX - (ptr - path);
164
165 dir = opendir(path);
166 if (!dir)
167 return NULL;
168
169 while((entry = readdir(dir))) {
170 if (entry->d_name[0] == '.' ||
171 !strncmp(entry->d_name, "..", 2))
172 continue;
173
174 strncpy(ptr, entry->d_name, space);
175 if (stat(path, &st) < 0)
176 continue;
177
178 if (S_ISDIR(st.st_mode)) {
179 result = __lookup_dev(path, dev, dir_level + 1, max_level);
180 if (result)
181 break;
182 } else if (S_ISBLK(st.st_mode)) {
183 /* workaround: ignore dm-X devices, these are internal kernel names */
184 if (dir_level == 0 && !strncmp(entry->d_name, "dm-", 3))
185 continue;
186 if (st.st_rdev == dev) {
187 result = strdup(path);
188 break;
189 }
190 }
191 }
192
193 closedir(dir);
194 return result;
195 }
196
lookup_dev(const char * dev_id)197 static char *lookup_dev(const char *dev_id)
198 {
199 uint32_t major, minor;
200 dev_t dev;
201 char *result = NULL, buf[PATH_MAX + 1];
202
203 if (sscanf(dev_id, "%" PRIu32 ":%" PRIu32, &major, &minor) != 2)
204 return NULL;
205
206 dev = makedev(major, minor);
207 strncpy(buf, DEVICE_DIR, PATH_MAX);
208 buf[PATH_MAX] = '\0';
209
210 /* First try low level device */
211 if ((result = __lookup_dev(buf, dev, 0, 0)))
212 return result;
213
214 /* If it is dm, try DM dir */
215 if (dm_is_dm_major(major)) {
216 strncpy(buf, dm_dir(), PATH_MAX);
217 if ((result = __lookup_dev(buf, dev, 0, 0)))
218 return result;
219 }
220
221 strncpy(buf, DEVICE_DIR, PATH_MAX);
222 result = __lookup_dev(buf, dev, 0, 4);
223
224 /* If not found, return NULL */
225 return result;
226 }
227
_dev_read_ahead(const char * dev,uint32_t * read_ahead)228 static int _dev_read_ahead(const char *dev, uint32_t *read_ahead)
229 {
230 int fd, r = 0;
231 long read_ahead_long;
232
233 if ((fd = open(dev, O_RDONLY)) < 0)
234 return 0;
235
236 r = 0;
237 //r = ioctl(fd, BLKRAGET, &read_ahead_long) ? 0 : 1;
238 close(fd);
239
240 if (r)
241 *read_ahead = (uint32_t) read_ahead_long;
242
243 return r;
244 }
245
hex_key(char * hexkey,size_t key_size,const char * key)246 static void hex_key(char *hexkey, size_t key_size, const char *key)
247 {
248 int i;
249
250 for(i = 0; i < key_size; i++)
251 sprintf(&hexkey[i * 2], "%02x", (unsigned char)key[i]);
252 }
253
get_params(const char * device,uint64_t skip,uint64_t offset,const char * cipher,size_t key_size,const char * key)254 static char *get_params(const char *device, uint64_t skip, uint64_t offset,
255 const char *cipher, size_t key_size, const char *key)
256 {
257 char *params;
258 char *hexkey;
259
260 hexkey = safe_alloc(key_size * 2 + 1);
261 if (!hexkey)
262 return NULL;
263
264 hex_key(hexkey, key_size, key);
265
266 params = safe_alloc(strlen(hexkey) + strlen(cipher) + strlen(device) + 64);
267 if (!params)
268 goto out;
269
270 sprintf(params, "%s %s %" PRIu64 " %s %" PRIu64,
271 cipher, hexkey, skip, device, offset);
272
273 out:
274 safe_free(hexkey);
275 return params;
276 }
277
278 /* DM helpers */
_dm_simple(int task,const char * name,int udev_wait)279 static int _dm_simple(int task, const char *name, int udev_wait)
280 {
281 int r = 0;
282 struct dm_task *dmt;
283 uint32_t cookie = 0;
284
285 if (!_dm_use_udev())
286 udev_wait = 0;
287
288 if (!(dmt = dm_task_create(task)))
289 return 0;
290
291 if (name && !dm_task_set_name(dmt, name))
292 goto out;
293
294 if (udev_wait && !dm_task_set_cookie(dmt, &cookie, 0))
295 goto out;
296
297 r = dm_task_run(dmt);
298
299 if (udev_wait)
300 (void)dm_udev_wait(cookie);
301
302 out:
303 dm_task_destroy(dmt);
304 return r;
305 }
306
_error_device(const char * name,size_t size)307 static int _error_device(const char *name, size_t size)
308 {
309 struct dm_task *dmt;
310 int r = 0;
311
312 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
313 return 0;
314
315 if (!dm_task_set_name(dmt, name))
316 goto error;
317
318 if (!dm_task_add_target(dmt, UINT64_C(0), size, "error", ""))
319 goto error;
320
321 if (!dm_task_set_ro(dmt))
322 goto error;
323
324 if (!dm_task_no_open_count(dmt))
325 goto error;
326
327 if (!dm_task_run(dmt))
328 goto error;
329
330 if (!_dm_simple(DM_DEVICE_RESUME, name, 1)) {
331 _dm_simple(DM_DEVICE_CLEAR, name, 0);
332 goto error;
333 }
334
335 r = 1;
336
337 error:
338 dm_task_destroy(dmt);
339 return r;
340 }
341
dm_remove_device(const char * name,int force,uint64_t size)342 int dm_remove_device(const char *name, int force, uint64_t size)
343 {
344 int r = -EINVAL;
345 int retries = force ? RETRY_COUNT : 1;
346 int error_target = 0;
347
348 if (!name || (force && !size))
349 return -EINVAL;
350
351 do {
352 r = _dm_simple(DM_DEVICE_REMOVE, name, 1) ? 0 : -EINVAL;
353 if (--retries && r) {
354 log_dbg("WARNING: other process locked internal device %s, %s.",
355 name, retries ? "retrying remove" : "giving up");
356 if (force && (crypt_get_debug_level() == CRYPT_LOG_DEBUG))
357 debug_processes_using_device(name);
358 sleep(1);
359 if (force && !error_target) {
360 /* If force flag is set, replace device with error, read-only target.
361 * it should stop processes from reading it and also removed underlying
362 * device from mapping, so it is usable again.
363 * Force flag should be used only for temporary devices, which are
364 * intended to work inside cryptsetup only!
365 * Anyway, if some process try to read temporary cryptsetup device,
366 * it is bug - no other process should try touch it (e.g. udev).
367 */
368 _error_device(name, size);
369 error_target = 1;
370 }
371 }
372 } while (r == -EINVAL && retries);
373
374 dm_task_update_nodes();
375
376 return r;
377 }
378
379 #define UUID_LEN 37 /* 36 + \0, libuuid ... */
380 /*
381 * UUID has format: CRYPT-<devicetype>-[<uuid>-]<device name>
382 * CRYPT-PLAIN-name
383 * CRYPT-LUKS1-00000000000000000000000000000000-name
384 * CRYPT-TEMP-name
385 */
dm_prepare_uuid(const char * name,const char * type,const char * uuid,char * buf,size_t buflen)386 static void dm_prepare_uuid(const char *name, const char *type, const char *uuid, char *buf, size_t buflen)
387 {
388 char *ptr, uuid2[UUID_LEN] = {0};
389 uuid_t uu;
390 int i = 0;
391 uint32_t ret;
392
393 /* Remove '-' chars */
394 if (uuid) {
395 uuid_from_string(uuid, &uu, &ret);
396 if (ret != uuid_s_ok) {
397 printf("error in uuid_from_string(%s), err = %d\n", uuid, ret);
398 for (ptr = uuid2, i = 0; i < UUID_LEN; i++) {
399 if (uuid[i] != '-') {
400 *ptr = uuid[i];
401 ptr++;
402 }
403 }
404 }
405 }
406
407 i = snprintf(buf, buflen, DM_UUID_PREFIX "%s%s%s%s%s",
408 type ?: "", type ? "-" : "",
409 uuid2[0] ? uuid2 : "", uuid2[0] ? "-" : "",
410 name);
411
412 log_dbg("DM-UUID is %s", buf);
413 if (i >= buflen)
414 log_err(NULL, _("DM-UUID for device %s was truncated.\n"), name);
415 }
416
dm_create_device(const char * name,const char * device,const char * cipher,const char * type,const char * uuid,uint64_t size,uint64_t skip,uint64_t offset,size_t key_size,const char * key,int read_only,int reload)417 int dm_create_device(const char *name,
418 const char *device,
419 const char *cipher,
420 const char *type,
421 const char *uuid,
422 uint64_t size,
423 uint64_t skip,
424 uint64_t offset,
425 size_t key_size,
426 const char *key,
427 int read_only,
428 int reload)
429 {
430 struct dm_task *dmt = NULL;
431 struct dm_info dmi;
432 char *params = NULL;
433 char *error = NULL;
434 char dev_uuid[DM_UUID_LEN] = {0};
435 int r = -EINVAL;
436 uint32_t read_ahead = 0;
437 uint32_t cookie = 0;
438 uint16_t udev_flags = 0;
439
440 params = get_params(device, skip, offset, cipher, key_size, key);
441 if (!params)
442 goto out_no_removal;
443
444 if (type && !strncmp(type, "TEMP", 4))
445 udev_flags = CRYPT_TEMP_UDEV_FLAGS;
446
447 /* All devices must have DM_UUID, only resize on old device is exception */
448 if (reload) {
449 if (!(dmt = dm_task_create(DM_DEVICE_RELOAD)))
450 goto out_no_removal;
451
452 if (!dm_task_set_name(dmt, name))
453 goto out_no_removal;
454 } else {
455 dm_prepare_uuid(name, type, uuid, dev_uuid, sizeof(dev_uuid));
456
457 if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
458 goto out_no_removal;
459
460 if (!dm_task_set_name(dmt, name))
461 goto out_no_removal;
462
463 if (!dm_task_set_uuid(dmt, dev_uuid))
464 goto out_no_removal;
465
466 if (_dm_use_udev() && !dm_task_set_cookie(dmt, &cookie, udev_flags))
467 goto out_no_removal;
468 }
469
470 if (read_only && !dm_task_set_ro(dmt))
471 goto out_no_removal;
472 if (!dm_task_add_target(dmt, 0, size, DM_CRYPT_TARGET, params))
473 goto out_no_removal;
474
475 #ifdef DM_READ_AHEAD_MINIMUM_FLAG
476 if (_dev_read_ahead(device, &read_ahead) &&
477 !dm_task_set_read_ahead(dmt, read_ahead, DM_READ_AHEAD_MINIMUM_FLAG))
478 goto out_no_removal;
479 #endif
480
481 if (!dm_task_run(dmt))
482 goto out_no_removal;
483
484 if (reload) {
485 dm_task_destroy(dmt);
486 if (!(dmt = dm_task_create(DM_DEVICE_RESUME)))
487 goto out;
488 if (!dm_task_set_name(dmt, name))
489 goto out;
490 if (uuid && !dm_task_set_uuid(dmt, dev_uuid))
491 goto out;
492 if (_dm_use_udev() && !dm_task_set_cookie(dmt, &cookie, udev_flags))
493 goto out;
494 if (!dm_task_run(dmt))
495 goto out;
496 }
497
498 if (!dm_task_get_info(dmt, &dmi))
499 goto out;
500
501 r = 0;
502 out:
503 if (_dm_use_udev()) {
504 (void)dm_udev_wait(cookie);
505 cookie = 0;
506 }
507
508 if (r < 0 && !reload) {
509 if (get_error())
510 error = strdup(get_error());
511
512 dm_remove_device(name, 0, 0);
513
514 if (error) {
515 set_error(error);
516 free(error);
517 }
518 }
519
520 out_no_removal:
521 if (cookie && _dm_use_udev())
522 (void)dm_udev_wait(cookie);
523
524 if (params)
525 safe_free(params);
526 if (dmt)
527 dm_task_destroy(dmt);
528
529 dm_task_update_nodes();
530 return r;
531 }
532
dm_status_device(const char * name)533 int dm_status_device(const char *name)
534 {
535 struct dm_task *dmt;
536 struct dm_info dmi;
537 uint64_t start, length;
538 char *target_type, *params;
539 void *next = NULL;
540 int r = -EINVAL;
541
542 if (!(dmt = dm_task_create(DM_DEVICE_STATUS)))
543 return -EINVAL;
544
545 if (!dm_task_set_name(dmt, name)) {
546 r = -EINVAL;
547 goto out;
548 }
549
550 if (!dm_task_run(dmt)) {
551 r = -EINVAL;
552 goto out;
553 }
554
555 if (!dm_task_get_info(dmt, &dmi)) {
556 r = -EINVAL;
557 goto out;
558 }
559
560 if (!dmi.exists) {
561 r = -ENODEV;
562 goto out;
563 }
564
565 next = dm_get_next_target(dmt, next, &start, &length,
566 &target_type, ¶ms);
567 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
568 start != 0 || next)
569 r = -EINVAL;
570 else
571 r = (dmi.open_count > 0);
572 out:
573 if (dmt)
574 dm_task_destroy(dmt);
575
576 return r;
577 }
578
dm_query_device(const char * name,char ** device,uint64_t * size,uint64_t * skip,uint64_t * offset,char ** cipher,int * key_size,char ** key,int * read_only,int * suspended,char ** uuid)579 int dm_query_device(const char *name,
580 char **device,
581 uint64_t *size,
582 uint64_t *skip,
583 uint64_t *offset,
584 char **cipher,
585 int *key_size,
586 char **key,
587 int *read_only,
588 int *suspended,
589 char **uuid)
590 {
591 struct dm_task *dmt;
592 struct dm_info dmi;
593 uint64_t start, length, val64;
594 char *target_type, *params, *rcipher, *key_, *rdevice, *endp, buffer[3], *tmp_uuid;
595 void *next = NULL;
596 int i, r = -EINVAL;
597
598 if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
599 goto out;
600 if (!dm_task_set_name(dmt, name))
601 goto out;
602 r = -ENODEV;
603 if (!dm_task_run(dmt))
604 goto out;
605
606 r = -EINVAL;
607 if (!dm_task_get_info(dmt, &dmi))
608 goto out;
609
610 if (!dmi.exists) {
611 r = -ENODEV;
612 goto out;
613 }
614
615 next = dm_get_next_target(dmt, next, &start, &length,
616 &target_type, ¶ms);
617 if (!target_type || strcmp(target_type, DM_CRYPT_TARGET) != 0 ||
618 start != 0 || next)
619 goto out;
620
621 if (size)
622 *size = length;
623
624 rcipher = strsep(¶ms, " ");
625 /* cipher */
626 if (cipher)
627 *cipher = strdup(rcipher);
628
629 /* skip */
630 key_ = strsep(¶ms, " ");
631 if (!params)
632 goto out;
633 val64 = strtoull(params, ¶ms, 10);
634 if (*params != ' ')
635 goto out;
636 params++;
637 if (skip)
638 *skip = val64;
639
640 /* device */
641 rdevice = strsep(¶ms, " ");
642 if (device)
643 *device = lookup_dev(rdevice);
644
645 /*offset */
646 if (!params)
647 goto out;
648 val64 = strtoull(params, ¶ms, 10);
649 if (*params)
650 goto out;
651 if (offset)
652 *offset = val64;
653
654 /* key_size */
655 if (key_size)
656 *key_size = strlen(key_) / 2;
657
658 /* key */
659 if (key_size && key) {
660 *key = safe_alloc(*key_size);
661 if (!*key) {
662 r = -ENOMEM;
663 goto out;
664 }
665
666 buffer[2] = '\0';
667 for(i = 0; i < *key_size; i++) {
668 memcpy(buffer, &key_[i * 2], 2);
669 (*key)[i] = strtoul(buffer, &endp, 16);
670 if (endp != &buffer[2]) {
671 safe_free(key);
672 *key = NULL;
673 goto out;
674 }
675 }
676 }
677 memset(key_, 0, strlen(key_));
678
679 if (read_only)
680 *read_only = dmi.read_only;
681
682 if (suspended)
683 *suspended = dmi.suspended;
684
685 if (uuid && (tmp_uuid = (char*)dm_task_get_uuid(dmt)) &&
686 !strncmp(tmp_uuid, DM_UUID_PREFIX, DM_UUID_PREFIX_LEN))
687 *uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);
688
689 r = (dmi.open_count > 0);
690 out:
691 if (dmt)
692 dm_task_destroy(dmt);
693
694 return r;
695 }
696
_dm_message(const char * name,const char * msg)697 static int _dm_message(const char *name, const char *msg)
698 {
699 int r = 0;
700 struct dm_task *dmt;
701
702 if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
703 return 0;
704
705 if (name && !dm_task_set_name(dmt, name))
706 goto out;
707
708 if (!dm_task_set_sector(dmt, (uint64_t) 0))
709 goto out;
710
711 if (!dm_task_set_message(dmt, msg))
712 goto out;
713
714 r = dm_task_run(dmt);
715
716 out:
717 dm_task_destroy(dmt);
718 return r;
719 }
720
dm_suspend_and_wipe_key(const char * name)721 int dm_suspend_and_wipe_key(const char *name)
722 {
723 if (!_dm_check_versions())
724 return -ENOTSUP;
725
726 if (!_dm_crypt_wipe_key_supported)
727 return -ENOTSUP;
728
729 if (!_dm_simple(DM_DEVICE_SUSPEND, name, 0))
730 return -EINVAL;
731
732 if (!_dm_message(name, "key wipe")) {
733 _dm_simple(DM_DEVICE_RESUME, name, 1);
734 return -EINVAL;
735 }
736
737 return 0;
738 }
739
dm_resume_and_reinstate_key(const char * name,size_t key_size,const char * key)740 int dm_resume_and_reinstate_key(const char *name,
741 size_t key_size,
742 const char *key)
743 {
744 int msg_size = key_size * 2 + 10; // key set <key>
745 char *msg;
746 int r = 0;
747
748 if (!_dm_check_versions())
749 return -ENOTSUP;
750
751 if (!_dm_crypt_wipe_key_supported)
752 return -ENOTSUP;
753
754 msg = safe_alloc(msg_size);
755 if (!msg)
756 return -ENOMEM;
757
758 memset(msg, 0, msg_size);
759 strcpy(msg, "key set ");
760 hex_key(&msg[8], key_size, key);
761
762 if (!_dm_message(name, msg) ||
763 !_dm_simple(DM_DEVICE_RESUME, name, 1))
764 r = -EINVAL;
765
766 safe_free(msg);
767 return r;
768 }
769
dm_get_dir(void)770 const char *dm_get_dir(void)
771 {
772 return dm_dir();
773 }
774