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Merge pull request #24933 from keszybz/erradicate-strerror
[thirdparty/systemd.git] / src / shared / dissect-image.c
1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #if HAVE_VALGRIND_MEMCHECK_H
4 #include <valgrind/memcheck.h>
5 #endif
6
7 #include <linux/dm-ioctl.h>
8 #include <linux/loop.h>
9 #include <sys/file.h>
10 #include <sys/mount.h>
11 #include <sys/prctl.h>
12 #include <sys/wait.h>
13 #include <sysexits.h>
14
15 #if HAVE_OPENSSL
16 #include <openssl/err.h>
17 #include <openssl/pem.h>
18 #include <openssl/x509.h>
19 #endif
20
21 #include "sd-device.h"
22 #include "sd-id128.h"
23
24 #include "architecture.h"
25 #include "ask-password-api.h"
26 #include "blkid-util.h"
27 #include "blockdev-util.h"
28 #include "chase-symlinks.h"
29 #include "conf-files.h"
30 #include "copy.h"
31 #include "cryptsetup-util.h"
32 #include "def.h"
33 #include "device-nodes.h"
34 #include "device-util.h"
35 #include "discover-image.h"
36 #include "dissect-image.h"
37 #include "dm-util.h"
38 #include "env-file.h"
39 #include "env-util.h"
40 #include "extension-release.h"
41 #include "fd-util.h"
42 #include "fileio.h"
43 #include "fs-util.h"
44 #include "fsck-util.h"
45 #include "gpt.h"
46 #include "hexdecoct.h"
47 #include "hostname-setup.h"
48 #include "id128-util.h"
49 #include "import-util.h"
50 #include "io-util.h"
51 #include "mkdir-label.h"
52 #include "mount-util.h"
53 #include "mountpoint-util.h"
54 #include "namespace-util.h"
55 #include "nulstr-util.h"
56 #include "openssl-util.h"
57 #include "os-util.h"
58 #include "path-util.h"
59 #include "process-util.h"
60 #include "raw-clone.h"
61 #include "resize-fs.h"
62 #include "signal-util.h"
63 #include "stat-util.h"
64 #include "stdio-util.h"
65 #include "string-table.h"
66 #include "string-util.h"
67 #include "strv.h"
68 #include "tmpfile-util.h"
69 #include "udev-util.h"
70 #include "user-util.h"
71 #include "xattr-util.h"
72
73 /* how many times to wait for the device nodes to appear */
74 #define N_DEVICE_NODE_LIST_ATTEMPTS 10
75
76 int probe_filesystem(const char *node, char **ret_fstype) {
77 /* Try to find device content type and return it in *ret_fstype. If nothing is found,
78 * 0/NULL will be returned. -EUCLEAN will be returned for ambiguous results, and an
79 * different error otherwise. */
80
81 #if HAVE_BLKID
82 _cleanup_(blkid_free_probep) blkid_probe b = NULL;
83 const char *fstype;
84 int r;
85
86 errno = 0;
87 b = blkid_new_probe_from_filename(node);
88 if (!b)
89 return errno_or_else(ENOMEM);
90
91 blkid_probe_enable_superblocks(b, 1);
92 blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
93
94 errno = 0;
95 r = blkid_do_safeprobe(b);
96 if (r == 1)
97 goto not_found;
98 if (r == -2)
99 return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN),
100 "Results ambiguous for partition %s", node);
101 if (r != 0)
102 return log_debug_errno(errno_or_else(EIO), "Failed to probe partition %s: %m", node);
103
104 (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
105
106 if (fstype) {
107 char *t;
108
109 log_debug("Probed fstype '%s' on partition %s.", fstype, node);
110
111 t = strdup(fstype);
112 if (!t)
113 return -ENOMEM;
114
115 *ret_fstype = t;
116 return 1;
117 }
118
119 not_found:
120 log_debug("No type detected on partition %s", node);
121 *ret_fstype = NULL;
122 return 0;
123 #else
124 return -EOPNOTSUPP;
125 #endif
126 }
127
128 #if HAVE_BLKID
129 static int dissected_image_probe_filesystem(DissectedImage *m) {
130 int r;
131
132 assert(m);
133
134 /* Fill in file system types if we don't know them yet. */
135
136 for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
137 DissectedPartition *p = m->partitions + i;
138
139 if (!p->found)
140 continue;
141
142 if (!p->fstype && p->node) {
143 r = probe_filesystem(p->node, &p->fstype);
144 if (r < 0 && r != -EUCLEAN)
145 return r;
146 }
147
148 if (streq_ptr(p->fstype, "crypto_LUKS"))
149 m->encrypted = true;
150
151 if (p->fstype && fstype_is_ro(p->fstype))
152 p->rw = false;
153
154 if (!p->rw)
155 p->growfs = false;
156 }
157
158 return 0;
159 }
160
161 static void check_partition_flags(
162 const char *node,
163 unsigned long long pflags,
164 unsigned long long supported) {
165
166 assert(node);
167
168 /* Mask away all flags supported by this partition's type and the three flags the UEFI spec defines generically */
169 pflags &= ~(supported |
170 SD_GPT_FLAG_REQUIRED_PARTITION |
171 SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL |
172 SD_GPT_FLAG_LEGACY_BIOS_BOOTABLE);
173
174 if (pflags == 0)
175 return;
176
177 /* If there are other bits set, then log about it, to make things discoverable */
178 for (unsigned i = 0; i < sizeof(pflags) * 8; i++) {
179 unsigned long long bit = 1ULL << i;
180 if (!FLAGS_SET(pflags, bit))
181 continue;
182
183 log_debug("Unexpected partition flag %llu set on %s!", bit, node);
184 }
185 }
186 #endif
187
188 #if HAVE_BLKID
189 static int dissected_image_new(const char *path, DissectedImage **ret) {
190 _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
191 _cleanup_free_ char *name = NULL;
192 int r;
193
194 assert(ret);
195
196 if (path) {
197 _cleanup_free_ char *filename = NULL;
198
199 r = path_extract_filename(path, &filename);
200 if (r < 0)
201 return r;
202
203 r = raw_strip_suffixes(filename, &name);
204 if (r < 0)
205 return r;
206
207 if (!image_name_is_valid(name)) {
208 log_debug("Image name %s is not valid, ignoring.", strna(name));
209 name = mfree(name);
210 }
211 }
212
213 m = new(DissectedImage, 1);
214 if (!m)
215 return -ENOMEM;
216
217 *m = (DissectedImage) {
218 .has_init_system = -1,
219 .image_name = TAKE_PTR(name),
220 };
221
222 for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
223 m->partitions[i] = DISSECTED_PARTITION_NULL;
224
225 *ret = TAKE_PTR(m);
226 return 0;
227 }
228 #endif
229
230 static void dissected_partition_done(DissectedPartition *p) {
231 assert(p);
232
233 free(p->fstype);
234 free(p->node);
235 free(p->label);
236 free(p->decrypted_fstype);
237 free(p->decrypted_node);
238 free(p->mount_options);
239
240 *p = DISSECTED_PARTITION_NULL;
241 }
242
243 #if HAVE_BLKID
244 static int make_partition_devname(
245 const char *whole_devname,
246 int nr,
247 char **ret) {
248
249 bool need_p;
250
251 assert(whole_devname);
252 assert(nr > 0);
253
254 /* Given a whole block device node name (e.g. /dev/sda or /dev/loop7) generate a partition device
255 * name (e.g. /dev/sda7 or /dev/loop7p5). The rule the kernel uses is simple: if whole block device
256 * node name ends in a digit, then suffix a 'p', followed by the partition number. Otherwise, just
257 * suffix the partition number without any 'p'. */
258
259 if (isempty(whole_devname)) /* Make sure there *is* a last char */
260 return -EINVAL;
261
262 need_p = ascii_isdigit(whole_devname[strlen(whole_devname)-1]); /* Last char a digit? */
263
264 return asprintf(ret, "%s%s%i", whole_devname, need_p ? "p" : "", nr);
265 }
266
267 static int dissect_image(
268 DissectedImage *m,
269 int fd,
270 const char *devname,
271 const VeritySettings *verity,
272 const MountOptions *mount_options,
273 DissectImageFlags flags) {
274
275 sd_id128_t root_uuid = SD_ID128_NULL, root_verity_uuid = SD_ID128_NULL;
276 sd_id128_t usr_uuid = SD_ID128_NULL, usr_verity_uuid = SD_ID128_NULL;
277 bool is_gpt, is_mbr, multiple_generic = false,
278 generic_rw = false, /* initialize to appease gcc */
279 generic_growfs = false;
280 _cleanup_(blkid_free_probep) blkid_probe b = NULL;
281 _cleanup_free_ char *generic_node = NULL;
282 sd_id128_t generic_uuid = SD_ID128_NULL;
283 const char *pttype = NULL;
284 blkid_partlist pl;
285 int r, generic_nr = -1, n_partitions;
286
287 assert(m);
288 assert(fd >= 0);
289 assert(devname);
290 assert(!verity || verity->designator < 0 || IN_SET(verity->designator, PARTITION_ROOT, PARTITION_USR));
291 assert(!verity || verity->root_hash || verity->root_hash_size == 0);
292 assert(!verity || verity->root_hash_sig || verity->root_hash_sig_size == 0);
293 assert(!verity || (verity->root_hash || !verity->root_hash_sig));
294 assert(!((flags & DISSECT_IMAGE_GPT_ONLY) && (flags & DISSECT_IMAGE_NO_PARTITION_TABLE)));
295
296 /* Probes a disk image, and returns information about what it found in *ret.
297 *
298 * Returns -ENOPKG if no suitable partition table or file system could be found.
299 * Returns -EADDRNOTAVAIL if a root hash was specified but no matching root/verity partitions found.
300 * Returns -ENXIO if we couldn't find any partition suitable as root or /usr partition
301 * Returns -ENOTUNIQ if we only found multiple generic partitions and thus don't know what to do with that */
302
303 if (verity && verity->root_hash) {
304 sd_id128_t fsuuid, vuuid;
305
306 /* If a root hash is supplied, then we use the root partition that has a UUID that match the
307 * first 128bit of the root hash. And we use the verity partition that has a UUID that match
308 * the final 128bit. */
309
310 if (verity->root_hash_size < sizeof(sd_id128_t))
311 return -EINVAL;
312
313 memcpy(&fsuuid, verity->root_hash, sizeof(sd_id128_t));
314 memcpy(&vuuid, (const uint8_t*) verity->root_hash + verity->root_hash_size - sizeof(sd_id128_t), sizeof(sd_id128_t));
315
316 if (sd_id128_is_null(fsuuid))
317 return -EINVAL;
318 if (sd_id128_is_null(vuuid))
319 return -EINVAL;
320
321 /* If the verity data declares it's for the /usr partition, then search for that, in all
322 * other cases assume it's for the root partition. */
323 if (verity->designator == PARTITION_USR) {
324 usr_uuid = fsuuid;
325 usr_verity_uuid = vuuid;
326 } else {
327 root_uuid = fsuuid;
328 root_verity_uuid = vuuid;
329 }
330 }
331
332 b = blkid_new_probe();
333 if (!b)
334 return -ENOMEM;
335
336 errno = 0;
337 r = blkid_probe_set_device(b, fd, 0, 0);
338 if (r != 0)
339 return errno_or_else(ENOMEM);
340
341 if ((flags & DISSECT_IMAGE_GPT_ONLY) == 0) {
342 /* Look for file system superblocks, unless we only shall look for GPT partition tables */
343 blkid_probe_enable_superblocks(b, 1);
344 blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE|BLKID_SUBLKS_USAGE);
345 }
346
347 blkid_probe_enable_partitions(b, 1);
348 blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
349
350 errno = 0;
351 r = blkid_do_safeprobe(b);
352 if (IN_SET(r, -2, 1))
353 return log_debug_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to identify any partition table.");
354 if (r != 0)
355 return errno_or_else(EIO);
356
357 if ((!(flags & DISSECT_IMAGE_GPT_ONLY) &&
358 (flags & DISSECT_IMAGE_GENERIC_ROOT)) ||
359 (flags & DISSECT_IMAGE_NO_PARTITION_TABLE)) {
360 const char *usage = NULL;
361
362 /* If flags permit this, also allow using non-partitioned single-filesystem images */
363
364 (void) blkid_probe_lookup_value(b, "USAGE", &usage, NULL);
365 if (STRPTR_IN_SET(usage, "filesystem", "crypto")) {
366 _cleanup_free_ char *t = NULL, *n = NULL, *o = NULL;
367 const char *fstype = NULL, *options = NULL;
368
369 /* OK, we have found a file system, that's our root partition then. */
370 (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
371
372 if (fstype) {
373 t = strdup(fstype);
374 if (!t)
375 return -ENOMEM;
376 }
377
378 n = strdup(devname);
379 if (!n)
380 return -ENOMEM;
381
382 m->single_file_system = true;
383 m->encrypted = streq_ptr(fstype, "crypto_LUKS");
384
385 m->has_verity = verity && verity->data_path;
386 m->verity_ready = m->has_verity &&
387 verity->root_hash &&
388 (verity->designator < 0 || verity->designator == PARTITION_ROOT);
389
390 m->has_verity_sig = false; /* signature not embedded, must be specified */
391 m->verity_sig_ready = m->verity_ready &&
392 verity->root_hash_sig;
393
394 options = mount_options_from_designator(mount_options, PARTITION_ROOT);
395 if (options) {
396 o = strdup(options);
397 if (!o)
398 return -ENOMEM;
399 }
400
401 m->partitions[PARTITION_ROOT] = (DissectedPartition) {
402 .found = true,
403 .rw = !m->verity_ready && !fstype_is_ro(fstype),
404 .partno = -1,
405 .architecture = _ARCHITECTURE_INVALID,
406 .fstype = TAKE_PTR(t),
407 .node = TAKE_PTR(n),
408 .mount_options = TAKE_PTR(o),
409 .offset = 0,
410 .size = UINT64_MAX,
411 };
412
413 return 0;
414 }
415 }
416
417 (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
418 if (!pttype)
419 return -ENOPKG;
420
421 is_gpt = streq_ptr(pttype, "gpt");
422 is_mbr = streq_ptr(pttype, "dos");
423
424 if (!is_gpt && ((flags & DISSECT_IMAGE_GPT_ONLY) || !is_mbr))
425 return -ENOPKG;
426
427 /* We support external verity data partitions only if the image has no partition table */
428 if (verity && verity->data_path)
429 return -EBADR;
430
431 if (FLAGS_SET(flags, DISSECT_IMAGE_MANAGE_PARTITION_DEVICES)) {
432 /* Safety check: refuse block devices that carry a partition table but for which the kernel doesn't
433 * do partition scanning. */
434 r = blockdev_partscan_enabled(fd);
435 if (r < 0)
436 return r;
437 if (r == 0)
438 return -EPROTONOSUPPORT;
439 }
440
441 errno = 0;
442 pl = blkid_probe_get_partitions(b);
443 if (!pl)
444 return errno_or_else(ENOMEM);
445
446 errno = 0;
447 n_partitions = blkid_partlist_numof_partitions(pl);
448 if (n_partitions < 0)
449 return errno_or_else(EIO);
450
451 for (int i = 0; i < n_partitions; i++) {
452 _cleanup_free_ char *node = NULL;
453 unsigned long long pflags;
454 blkid_loff_t start, size;
455 blkid_partition pp;
456 int nr;
457
458 errno = 0;
459 pp = blkid_partlist_get_partition(pl, i);
460 if (!pp)
461 return errno_or_else(EIO);
462
463 pflags = blkid_partition_get_flags(pp);
464
465 errno = 0;
466 nr = blkid_partition_get_partno(pp);
467 if (nr < 0)
468 return errno_or_else(EIO);
469
470 errno = 0;
471 start = blkid_partition_get_start(pp);
472 if (start < 0)
473 return errno_or_else(EIO);
474
475 assert((uint64_t) start < UINT64_MAX/512);
476
477 errno = 0;
478 size = blkid_partition_get_size(pp);
479 if (size < 0)
480 return errno_or_else(EIO);
481
482 assert((uint64_t) size < UINT64_MAX/512);
483
484 r = make_partition_devname(devname, nr, &node);
485 if (r < 0)
486 return r;
487
488 /* So here's the thing: after the main ("whole") block device popped up it might take a while
489 * before the kernel fully probed the partition table. Waiting for that to finish is icky in
490 * userspace. So here's what we do instead. We issue the BLKPG_ADD_PARTITION ioctl to add the
491 * partition ourselves, racing against the kernel. Good thing is: if this call fails with
492 * EBUSY then the kernel was quicker than us, and that's totally OK, the outcome is good for
493 * us: the device node will exist. If OTOH our call was successful we won the race. Which is
494 * also good as the outcome is the same: the partition block device exists, and we can use
495 * it.
496 *
497 * Kernel returns EBUSY if there's already a partition by that number or an overlapping
498 * partition already existent. */
499
500 if (FLAGS_SET(flags, DISSECT_IMAGE_MANAGE_PARTITION_DEVICES)) {
501 r = block_device_add_partition(fd, node, nr, (uint64_t) start * 512, (uint64_t) size * 512);
502 if (r < 0) {
503 if (r != -EBUSY)
504 return log_debug_errno(r, "BLKPG_ADD_PARTITION failed: %m");
505
506 log_debug_errno(r, "Kernel was quicker than us in adding partition %i.", nr);
507 } else
508 log_debug("We were quicker than kernel in adding partition %i.", nr);
509 }
510
511 if (is_gpt) {
512 PartitionDesignator designator = _PARTITION_DESIGNATOR_INVALID;
513 Architecture architecture = _ARCHITECTURE_INVALID;
514 const char *stype, *sid, *fstype = NULL, *label;
515 sd_id128_t type_id, id;
516 bool rw = true, growfs = false;
517
518 sid = blkid_partition_get_uuid(pp);
519 if (!sid)
520 continue;
521 if (sd_id128_from_string(sid, &id) < 0)
522 continue;
523
524 stype = blkid_partition_get_type_string(pp);
525 if (!stype)
526 continue;
527 if (sd_id128_from_string(stype, &type_id) < 0)
528 continue;
529
530 label = blkid_partition_get_name(pp); /* libblkid returns NULL here if empty */
531
532 if (sd_id128_equal(type_id, SD_GPT_HOME)) {
533
534 check_partition_flags(node, pflags,
535 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
536
537 if (pflags & SD_GPT_FLAG_NO_AUTO)
538 continue;
539
540 designator = PARTITION_HOME;
541 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
542 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
543
544 } else if (sd_id128_equal(type_id, SD_GPT_SRV)) {
545
546 check_partition_flags(node, pflags,
547 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
548
549 if (pflags & SD_GPT_FLAG_NO_AUTO)
550 continue;
551
552 designator = PARTITION_SRV;
553 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
554 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
555
556 } else if (sd_id128_equal(type_id, SD_GPT_ESP)) {
557
558 /* Note that we don't check the SD_GPT_FLAG_NO_AUTO flag for the ESP, as it is
559 * not defined there. We instead check the SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL, as
560 * recommended by the UEFI spec (See "12.3.3 Number and Location of System
561 * Partitions"). */
562
563 if (pflags & SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL)
564 continue;
565
566 designator = PARTITION_ESP;
567 fstype = "vfat";
568
569 } else if (sd_id128_equal(type_id, SD_GPT_XBOOTLDR)) {
570
571 check_partition_flags(node, pflags,
572 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
573
574 if (pflags & SD_GPT_FLAG_NO_AUTO)
575 continue;
576
577 designator = PARTITION_XBOOTLDR;
578 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
579 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
580
581 } else if (gpt_partition_type_is_root(type_id)) {
582
583 check_partition_flags(node, pflags,
584 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
585
586 if (pflags & SD_GPT_FLAG_NO_AUTO)
587 continue;
588
589 /* If a root ID is specified, ignore everything but the root id */
590 if (!sd_id128_is_null(root_uuid) && !sd_id128_equal(root_uuid, id))
591 continue;
592
593 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
594 designator = PARTITION_ROOT_OF_ARCH(architecture);
595 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
596 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
597
598 } else if (gpt_partition_type_is_root_verity(type_id)) {
599
600 check_partition_flags(node, pflags,
601 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
602
603 if (pflags & SD_GPT_FLAG_NO_AUTO)
604 continue;
605
606 m->has_verity = true;
607
608 /* If no verity configuration is specified, then don't do verity */
609 if (!verity)
610 continue;
611 if (verity->designator >= 0 && verity->designator != PARTITION_ROOT)
612 continue;
613
614 /* If root hash is specified, then ignore everything but the root id */
615 if (!sd_id128_is_null(root_verity_uuid) && !sd_id128_equal(root_verity_uuid, id))
616 continue;
617
618 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
619 designator = PARTITION_VERITY_OF(PARTITION_ROOT_OF_ARCH(architecture));
620 fstype = "DM_verity_hash";
621 rw = false;
622
623 } else if (gpt_partition_type_is_root_verity_sig(type_id)) {
624
625 check_partition_flags(node, pflags,
626 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
627
628 if (pflags & SD_GPT_FLAG_NO_AUTO)
629 continue;
630
631 m->has_verity_sig = true;
632
633 if (!verity)
634 continue;
635 if (verity->designator >= 0 && verity->designator != PARTITION_ROOT)
636 continue;
637
638 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
639 designator = PARTITION_VERITY_SIG_OF(PARTITION_ROOT_OF_ARCH(architecture));
640 fstype = "verity_hash_signature";
641 rw = false;
642
643 } else if (gpt_partition_type_is_usr(type_id)) {
644
645 check_partition_flags(node, pflags,
646 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
647
648 if (pflags & SD_GPT_FLAG_NO_AUTO)
649 continue;
650
651 /* If a usr ID is specified, ignore everything but the usr id */
652 if (!sd_id128_is_null(usr_uuid) && !sd_id128_equal(usr_uuid, id))
653 continue;
654
655 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
656 designator = PARTITION_USR_OF_ARCH(architecture);
657 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
658 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
659
660 } else if (gpt_partition_type_is_usr_verity(type_id)) {
661
662 check_partition_flags(node, pflags,
663 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
664
665 if (pflags & SD_GPT_FLAG_NO_AUTO)
666 continue;
667
668 m->has_verity = true;
669
670 if (!verity)
671 continue;
672 if (verity->designator >= 0 && verity->designator != PARTITION_USR)
673 continue;
674
675 /* If usr hash is specified, then ignore everything but the usr id */
676 if (!sd_id128_is_null(usr_verity_uuid) && !sd_id128_equal(usr_verity_uuid, id))
677 continue;
678
679 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
680 designator = PARTITION_VERITY_OF(PARTITION_USR_OF_ARCH(architecture));
681 fstype = "DM_verity_hash";
682 rw = false;
683
684 } else if (gpt_partition_type_is_usr_verity_sig(type_id)) {
685
686 check_partition_flags(node, pflags,
687 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
688
689 if (pflags & SD_GPT_FLAG_NO_AUTO)
690 continue;
691
692 m->has_verity_sig = true;
693
694 if (!verity)
695 continue;
696 if (verity->designator >= 0 && verity->designator != PARTITION_USR)
697 continue;
698
699 assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0);
700 designator = PARTITION_VERITY_SIG_OF(PARTITION_USR_OF_ARCH(architecture));
701 fstype = "verity_hash_signature";
702 rw = false;
703
704 } else if (sd_id128_equal(type_id, SD_GPT_SWAP)) {
705
706 check_partition_flags(node, pflags, SD_GPT_FLAG_NO_AUTO);
707
708 if (pflags & SD_GPT_FLAG_NO_AUTO)
709 continue;
710
711 designator = PARTITION_SWAP;
712
713 } else if (sd_id128_equal(type_id, SD_GPT_LINUX_GENERIC)) {
714
715 check_partition_flags(node, pflags,
716 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
717
718 if (pflags & SD_GPT_FLAG_NO_AUTO)
719 continue;
720
721 if (generic_node)
722 multiple_generic = true;
723 else {
724 generic_nr = nr;
725 generic_rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
726 generic_growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
727 generic_uuid = id;
728 generic_node = strdup(node);
729 if (!generic_node)
730 return -ENOMEM;
731 }
732
733 } else if (sd_id128_equal(type_id, SD_GPT_TMP)) {
734
735 check_partition_flags(node, pflags,
736 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
737
738 if (pflags & SD_GPT_FLAG_NO_AUTO)
739 continue;
740
741 designator = PARTITION_TMP;
742 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
743 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
744
745 } else if (sd_id128_equal(type_id, SD_GPT_VAR)) {
746
747 check_partition_flags(node, pflags,
748 SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
749
750 if (pflags & SD_GPT_FLAG_NO_AUTO)
751 continue;
752
753 if (!FLAGS_SET(flags, DISSECT_IMAGE_RELAX_VAR_CHECK)) {
754 sd_id128_t var_uuid;
755
756 /* For /var we insist that the uuid of the partition matches the
757 * HMAC-SHA256 of the /var GPT partition type uuid, keyed by machine
758 * ID. Why? Unlike the other partitions /var is inherently
759 * installation specific, hence we need to be careful not to mount it
760 * in the wrong installation. By hashing the partition UUID from
761 * /etc/machine-id we can securely bind the partition to the
762 * installation. */
763
764 r = sd_id128_get_machine_app_specific(SD_GPT_VAR, &var_uuid);
765 if (r < 0)
766 return r;
767
768 if (!sd_id128_equal(var_uuid, id)) {
769 log_debug("Found a /var/ partition, but its UUID didn't match our expectations, ignoring.");
770 continue;
771 }
772 }
773
774 designator = PARTITION_VAR;
775 rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
776 growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
777 }
778
779 if (designator != _PARTITION_DESIGNATOR_INVALID) {
780 _cleanup_free_ char *t = NULL, *o = NULL, *l = NULL;
781 const char *options = NULL;
782
783 if (m->partitions[designator].found) {
784 /* For most partition types the first one we see wins. Except for the
785 * rootfs and /usr, where we do a version compare of the label, and
786 * let the newest version win. This permits a simple A/B versioning
787 * scheme in OS images. */
788
789 if (!PARTITION_DESIGNATOR_VERSIONED(designator) ||
790 strverscmp_improved(m->partitions[designator].label, label) >= 0)
791 continue;
792
793 dissected_partition_done(m->partitions + designator);
794 }
795
796 if (fstype) {
797 t = strdup(fstype);
798 if (!t)
799 return -ENOMEM;
800 }
801
802 if (label) {
803 l = strdup(label);
804 if (!l)
805 return -ENOMEM;
806 }
807
808 options = mount_options_from_designator(mount_options, designator);
809 if (options) {
810 o = strdup(options);
811 if (!o)
812 return -ENOMEM;
813 }
814
815 m->partitions[designator] = (DissectedPartition) {
816 .found = true,
817 .partno = nr,
818 .rw = rw,
819 .growfs = growfs,
820 .architecture = architecture,
821 .node = TAKE_PTR(node),
822 .fstype = TAKE_PTR(t),
823 .label = TAKE_PTR(l),
824 .uuid = id,
825 .mount_options = TAKE_PTR(o),
826 .offset = (uint64_t) start * 512,
827 .size = (uint64_t) size * 512,
828 };
829 }
830
831 } else if (is_mbr) {
832
833 switch (blkid_partition_get_type(pp)) {
834
835 case 0x83: /* Linux partition */
836
837 if (pflags != 0x80) /* Bootable flag */
838 continue;
839
840 if (generic_node)
841 multiple_generic = true;
842 else {
843 generic_nr = nr;
844 generic_rw = true;
845 generic_growfs = false;
846 generic_node = strdup(node);
847 if (!generic_node)
848 return -ENOMEM;
849 }
850
851 break;
852
853 case 0xEA: { /* Boot Loader Spec extended $BOOT partition */
854 _cleanup_free_ char *o = NULL;
855 sd_id128_t id = SD_ID128_NULL;
856 const char *sid, *options = NULL;
857
858 /* First one wins */
859 if (m->partitions[PARTITION_XBOOTLDR].found)
860 continue;
861
862 sid = blkid_partition_get_uuid(pp);
863 if (sid)
864 (void) sd_id128_from_string(sid, &id);
865
866 options = mount_options_from_designator(mount_options, PARTITION_XBOOTLDR);
867 if (options) {
868 o = strdup(options);
869 if (!o)
870 return -ENOMEM;
871 }
872
873 m->partitions[PARTITION_XBOOTLDR] = (DissectedPartition) {
874 .found = true,
875 .partno = nr,
876 .rw = true,
877 .growfs = false,
878 .architecture = _ARCHITECTURE_INVALID,
879 .node = TAKE_PTR(node),
880 .uuid = id,
881 .mount_options = TAKE_PTR(o),
882 .offset = (uint64_t) start * 512,
883 .size = (uint64_t) size * 512,
884 };
885
886 break;
887 }}
888 }
889 }
890
891 if (m->partitions[PARTITION_ROOT].found) {
892 /* If we found the primary arch, then invalidate the secondary and other arch to avoid any
893 * ambiguities, since we never want to mount the secondary or other arch in this case. */
894 m->partitions[PARTITION_ROOT_SECONDARY].found = false;
895 m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found = false;
896 m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG].found = false;
897 m->partitions[PARTITION_USR_SECONDARY].found = false;
898 m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false;
899 m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found = false;
900
901 m->partitions[PARTITION_ROOT_OTHER].found = false;
902 m->partitions[PARTITION_ROOT_OTHER_VERITY].found = false;
903 m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG].found = false;
904 m->partitions[PARTITION_USR_OTHER].found = false;
905 m->partitions[PARTITION_USR_OTHER_VERITY].found = false;
906 m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false;
907
908 } else if (m->partitions[PARTITION_ROOT_VERITY].found ||
909 m->partitions[PARTITION_ROOT_VERITY_SIG].found)
910 return -EADDRNOTAVAIL; /* Verity found but no matching rootfs? Something is off, refuse. */
911
912 else if (m->partitions[PARTITION_ROOT_SECONDARY].found) {
913
914 /* No root partition found but there's one for the secondary architecture? Then upgrade
915 * secondary arch to first and invalidate the other arch. */
916
917 log_debug("No root partition found of the native architecture, falling back to a root "
918 "partition of the secondary architecture.");
919
920 m->partitions[PARTITION_ROOT] = m->partitions[PARTITION_ROOT_SECONDARY];
921 zero(m->partitions[PARTITION_ROOT_SECONDARY]);
922 m->partitions[PARTITION_ROOT_VERITY] = m->partitions[PARTITION_ROOT_SECONDARY_VERITY];
923 zero(m->partitions[PARTITION_ROOT_SECONDARY_VERITY]);
924 m->partitions[PARTITION_ROOT_VERITY_SIG] = m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG];
925 zero(m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG]);
926
927 m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_SECONDARY];
928 zero(m->partitions[PARTITION_USR_SECONDARY]);
929 m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_SECONDARY_VERITY];
930 zero(m->partitions[PARTITION_USR_SECONDARY_VERITY]);
931 m->partitions[PARTITION_USR_VERITY_SIG] = m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG];
932 zero(m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG]);
933
934 m->partitions[PARTITION_ROOT_OTHER].found = false;
935 m->partitions[PARTITION_ROOT_OTHER_VERITY].found = false;
936 m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG].found = false;
937 m->partitions[PARTITION_USR_OTHER].found = false;
938 m->partitions[PARTITION_USR_OTHER_VERITY].found = false;
939 m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false;
940
941 } else if (m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found ||
942 m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG].found)
943 return -EADDRNOTAVAIL; /* as above */
944
945 else if (m->partitions[PARTITION_ROOT_OTHER].found) {
946
947 /* No root or secondary partition found but there's one for another architecture? Then
948 * upgrade the other architecture to first. */
949
950 log_debug("No root partition found of the native architecture or the secondary architecture, "
951 "falling back to a root partition of a non-native architecture (%s).",
952 architecture_to_string(m->partitions[PARTITION_ROOT_OTHER].architecture));
953
954 m->partitions[PARTITION_ROOT] = m->partitions[PARTITION_ROOT_OTHER];
955 zero(m->partitions[PARTITION_ROOT_OTHER]);
956 m->partitions[PARTITION_ROOT_VERITY] = m->partitions[PARTITION_ROOT_OTHER_VERITY];
957 zero(m->partitions[PARTITION_ROOT_OTHER_VERITY]);
958 m->partitions[PARTITION_ROOT_VERITY_SIG] = m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG];
959 zero(m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG]);
960
961 m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_OTHER];
962 zero(m->partitions[PARTITION_USR_OTHER]);
963 m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_OTHER_VERITY];
964 zero(m->partitions[PARTITION_USR_OTHER_VERITY]);
965 m->partitions[PARTITION_USR_VERITY_SIG] = m->partitions[PARTITION_USR_OTHER_VERITY_SIG];
966 zero(m->partitions[PARTITION_USR_OTHER_VERITY_SIG]);
967 }
968
969 /* Hmm, we found a signature partition but no Verity data? Something is off. */
970 if (m->partitions[PARTITION_ROOT_VERITY_SIG].found && !m->partitions[PARTITION_ROOT_VERITY].found)
971 return -EADDRNOTAVAIL;
972
973 if (m->partitions[PARTITION_USR].found) {
974 /* Invalidate secondary and other arch /usr/ if we found the primary arch */
975 m->partitions[PARTITION_USR_SECONDARY].found = false;
976 m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false;
977 m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found = false;
978
979 m->partitions[PARTITION_USR_OTHER].found = false;
980 m->partitions[PARTITION_USR_OTHER_VERITY].found = false;
981 m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false;
982
983 } else if (m->partitions[PARTITION_USR_VERITY].found ||
984 m->partitions[PARTITION_USR_VERITY_SIG].found)
985 return -EADDRNOTAVAIL; /* as above */
986
987 else if (m->partitions[PARTITION_USR_SECONDARY].found) {
988
989 log_debug("No usr partition found of the native architecture, falling back to a usr "
990 "partition of the secondary architecture.");
991
992 /* Upgrade secondary arch to primary */
993 m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_SECONDARY];
994 zero(m->partitions[PARTITION_USR_SECONDARY]);
995 m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_SECONDARY_VERITY];
996 zero(m->partitions[PARTITION_USR_SECONDARY_VERITY]);
997 m->partitions[PARTITION_USR_VERITY_SIG] = m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG];
998 zero(m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG]);
999
1000 m->partitions[PARTITION_USR_OTHER].found = false;
1001 m->partitions[PARTITION_USR_OTHER_VERITY].found = false;
1002 m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false;
1003
1004 } else if (m->partitions[PARTITION_USR_SECONDARY_VERITY].found ||
1005 m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found)
1006 return -EADDRNOTAVAIL; /* as above */
1007
1008 else if (m->partitions[PARTITION_USR_OTHER].found) {
1009
1010 log_debug("No usr partition found of the native architecture or the secondary architecture, "
1011 "falling back to a usr partition of a non-native architecture (%s).",
1012 architecture_to_string(m->partitions[PARTITION_ROOT_OTHER].architecture));
1013
1014 /* Upgrade other arch to primary */
1015 m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_OTHER];
1016 zero(m->partitions[PARTITION_USR_OTHER]);
1017 m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_OTHER_VERITY];
1018 zero(m->partitions[PARTITION_USR_OTHER_VERITY]);
1019 m->partitions[PARTITION_USR_VERITY_SIG] = m->partitions[PARTITION_USR_OTHER_VERITY_SIG];
1020 zero(m->partitions[PARTITION_USR_OTHER_VERITY_SIG]);
1021 }
1022
1023 /* Hmm, we found a signature partition but no Verity data? Something is off. */
1024 if (m->partitions[PARTITION_USR_VERITY_SIG].found && !m->partitions[PARTITION_USR_VERITY].found)
1025 return -EADDRNOTAVAIL;
1026
1027 /* If root and /usr are combined then insist that the architecture matches */
1028 if (m->partitions[PARTITION_ROOT].found &&
1029 m->partitions[PARTITION_USR].found &&
1030 (m->partitions[PARTITION_ROOT].architecture >= 0 &&
1031 m->partitions[PARTITION_USR].architecture >= 0 &&
1032 m->partitions[PARTITION_ROOT].architecture != m->partitions[PARTITION_USR].architecture))
1033 return -EADDRNOTAVAIL;
1034
1035 if (!m->partitions[PARTITION_ROOT].found &&
1036 !m->partitions[PARTITION_USR].found &&
1037 (flags & DISSECT_IMAGE_GENERIC_ROOT) &&
1038 (!verity || !verity->root_hash || verity->designator != PARTITION_USR)) {
1039
1040 /* OK, we found nothing usable, then check if there's a single generic partition, and use
1041 * that. If the root hash was set however, then we won't fall back to a generic node, because
1042 * the root hash decides. */
1043
1044 /* If we didn't find a properly marked root partition, but we did find a single suitable
1045 * generic Linux partition, then use this as root partition, if the caller asked for it. */
1046 if (multiple_generic)
1047 return -ENOTUNIQ;
1048
1049 /* If we didn't find a generic node, then we can't fix this up either */
1050 if (generic_node) {
1051 _cleanup_free_ char *o = NULL;
1052 const char *options;
1053
1054 options = mount_options_from_designator(mount_options, PARTITION_ROOT);
1055 if (options) {
1056 o = strdup(options);
1057 if (!o)
1058 return -ENOMEM;
1059 }
1060
1061 assert(generic_nr >= 0);
1062 m->partitions[PARTITION_ROOT] = (DissectedPartition) {
1063 .found = true,
1064 .rw = generic_rw,
1065 .growfs = generic_growfs,
1066 .partno = generic_nr,
1067 .architecture = _ARCHITECTURE_INVALID,
1068 .node = TAKE_PTR(generic_node),
1069 .uuid = generic_uuid,
1070 .mount_options = TAKE_PTR(o),
1071 .offset = UINT64_MAX,
1072 .size = UINT64_MAX,
1073 };
1074 }
1075 }
1076
1077 /* Check if we have a root fs if we are told to do check. /usr alone is fine too, but only if appropriate flag for that is set too */
1078 if (FLAGS_SET(flags, DISSECT_IMAGE_REQUIRE_ROOT) &&
1079 !(m->partitions[PARTITION_ROOT].found || (m->partitions[PARTITION_USR].found && FLAGS_SET(flags, DISSECT_IMAGE_USR_NO_ROOT))))
1080 return -ENXIO;
1081
1082 if (m->partitions[PARTITION_ROOT_VERITY].found) {
1083 /* We only support one verity partition per image, i.e. can't do for both /usr and root fs */
1084 if (m->partitions[PARTITION_USR_VERITY].found)
1085 return -ENOTUNIQ;
1086
1087 /* We don't support verity enabled root with a split out /usr. Neither with nor without
1088 * verity there. (Note that we do support verity-less root with verity-full /usr, though.) */
1089 if (m->partitions[PARTITION_USR].found)
1090 return -EADDRNOTAVAIL;
1091 }
1092
1093 if (verity) {
1094 /* If a verity designator is specified, then insist that the matching partition exists */
1095 if (verity->designator >= 0 && !m->partitions[verity->designator].found)
1096 return -EADDRNOTAVAIL;
1097
1098 bool have_verity_sig_partition =
1099 m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR_VERITY_SIG : PARTITION_ROOT_VERITY_SIG].found;
1100
1101 if (verity->root_hash) {
1102 /* If we have an explicit root hash and found the partitions for it, then we are ready to use
1103 * Verity, set things up for it */
1104
1105 if (verity->designator < 0 || verity->designator == PARTITION_ROOT) {
1106 if (!m->partitions[PARTITION_ROOT_VERITY].found || !m->partitions[PARTITION_ROOT].found)
1107 return -EADDRNOTAVAIL;
1108
1109 /* If we found a verity setup, then the root partition is necessarily read-only. */
1110 m->partitions[PARTITION_ROOT].rw = false;
1111 m->verity_ready = true;
1112
1113 } else {
1114 assert(verity->designator == PARTITION_USR);
1115
1116 if (!m->partitions[PARTITION_USR_VERITY].found || !m->partitions[PARTITION_USR].found)
1117 return -EADDRNOTAVAIL;
1118
1119 m->partitions[PARTITION_USR].rw = false;
1120 m->verity_ready = true;
1121 }
1122
1123 if (m->verity_ready)
1124 m->verity_sig_ready = verity->root_hash_sig || have_verity_sig_partition;
1125
1126 } else if (have_verity_sig_partition) {
1127
1128 /* If we found an embedded signature partition, we are ready, too. */
1129
1130 m->verity_ready = m->verity_sig_ready = true;
1131 m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR : PARTITION_ROOT].rw = false;
1132 }
1133 }
1134
1135 return 0;
1136 }
1137 #endif
1138
1139 int dissect_image_file(
1140 const char *path,
1141 const VeritySettings *verity,
1142 const MountOptions *mount_options,
1143 DissectImageFlags flags,
1144 DissectedImage **ret) {
1145
1146 #if HAVE_BLKID
1147 _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
1148 _cleanup_close_ int fd = -1;
1149 int r;
1150
1151 assert(path);
1152 assert((flags & DISSECT_IMAGE_BLOCK_DEVICE) == 0);
1153 assert(ret);
1154
1155 fd = open(path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
1156 if (fd < 0)
1157 return -errno;
1158
1159 r = fd_verify_regular(fd);
1160 if (r < 0)
1161 return r;
1162
1163 r = dissected_image_new(path, &m);
1164 if (r < 0)
1165 return r;
1166
1167 r = dissect_image(m, fd, path, verity, mount_options, flags);
1168 if (r < 0)
1169 return r;
1170
1171 *ret = TAKE_PTR(m);
1172 return 0;
1173 #else
1174 return -EOPNOTSUPP;
1175 #endif
1176 }
1177
1178 DissectedImage* dissected_image_unref(DissectedImage *m) {
1179 if (!m)
1180 return NULL;
1181
1182 /* First, clear dissected partitions. */
1183 for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
1184 dissected_partition_done(m->partitions + i);
1185
1186 /* Second, free decrypted images. This must be after dissected_partition_done(), as freeing
1187 * DecryptedImage may try to deactivate partitions. */
1188 decrypted_image_unref(m->decrypted_image);
1189
1190 /* Third, unref LoopDevice. This must be called after the above two, as freeing LoopDevice may try to
1191 * remove existing partitions on the loopback block device. */
1192 loop_device_unref(m->loop);
1193
1194 free(m->image_name);
1195 free(m->hostname);
1196 strv_free(m->machine_info);
1197 strv_free(m->os_release);
1198 strv_free(m->extension_release);
1199
1200 return mfree(m);
1201 }
1202
1203 static int is_loop_device(const char *path) {
1204 char s[SYS_BLOCK_PATH_MAX("/../loop/")];
1205 struct stat st;
1206
1207 assert(path);
1208
1209 if (stat(path, &st) < 0)
1210 return -errno;
1211
1212 if (!S_ISBLK(st.st_mode))
1213 return -ENOTBLK;
1214
1215 xsprintf_sys_block_path(s, "/loop/", st.st_dev);
1216 if (access(s, F_OK) < 0) {
1217 if (errno != ENOENT)
1218 return -errno;
1219
1220 /* The device itself isn't a loop device, but maybe it's a partition and its parent is? */
1221 xsprintf_sys_block_path(s, "/../loop/", st.st_dev);
1222 if (access(s, F_OK) < 0)
1223 return errno == ENOENT ? false : -errno;
1224 }
1225
1226 return true;
1227 }
1228
1229 static int run_fsck(const char *node, const char *fstype) {
1230 int r, exit_status;
1231 pid_t pid;
1232
1233 assert(node);
1234 assert(fstype);
1235
1236 r = fsck_exists_for_fstype(fstype);
1237 if (r < 0) {
1238 log_debug_errno(r, "Couldn't determine whether fsck for %s exists, proceeding anyway.", fstype);
1239 return 0;
1240 }
1241 if (r == 0) {
1242 log_debug("Not checking partition %s, as fsck for %s does not exist.", node, fstype);
1243 return 0;
1244 }
1245
1246 r = safe_fork("(fsck)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_NULL_STDIO, &pid);
1247 if (r < 0)
1248 return log_debug_errno(r, "Failed to fork off fsck: %m");
1249 if (r == 0) {
1250 /* Child */
1251 execl("/sbin/fsck", "/sbin/fsck", "-aT", node, NULL);
1252 log_open();
1253 log_debug_errno(errno, "Failed to execl() fsck: %m");
1254 _exit(FSCK_OPERATIONAL_ERROR);
1255 }
1256
1257 exit_status = wait_for_terminate_and_check("fsck", pid, 0);
1258 if (exit_status < 0)
1259 return log_debug_errno(exit_status, "Failed to fork off /sbin/fsck: %m");
1260
1261 if ((exit_status & ~FSCK_ERROR_CORRECTED) != FSCK_SUCCESS) {
1262 log_debug("fsck failed with exit status %i.", exit_status);
1263
1264 if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0)
1265 return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), "File system is corrupted, refusing.");
1266
1267 log_debug("Ignoring fsck error.");
1268 }
1269
1270 return 0;
1271 }
1272
1273 static int fs_grow(const char *node_path, const char *mount_path) {
1274 _cleanup_close_ int mount_fd = -1, node_fd = -1;
1275 uint64_t size, newsize;
1276 int r;
1277
1278 node_fd = open(node_path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
1279 if (node_fd < 0)
1280 return log_debug_errno(errno, "Failed to open node device %s: %m", node_path);
1281
1282 if (ioctl(node_fd, BLKGETSIZE64, &size) != 0)
1283 return log_debug_errno(errno, "Failed to get block device size of %s: %m", node_path);
1284
1285 mount_fd = open(mount_path, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
1286 if (mount_fd < 0)
1287 return log_debug_errno(errno, "Failed to open mountd file system %s: %m", mount_path);
1288
1289 log_debug("Resizing \"%s\" to %"PRIu64" bytes...", mount_path, size);
1290 r = resize_fs(mount_fd, size, &newsize);
1291 if (r < 0)
1292 return log_debug_errno(r, "Failed to resize \"%s\" to %"PRIu64" bytes: %m", mount_path, size);
1293
1294 if (newsize == size)
1295 log_debug("Successfully resized \"%s\" to %s bytes.",
1296 mount_path, FORMAT_BYTES(newsize));
1297 else {
1298 assert(newsize < size);
1299 log_debug("Successfully resized \"%s\" to %s bytes (%"PRIu64" bytes lost due to blocksize).",
1300 mount_path, FORMAT_BYTES(newsize), size - newsize);
1301 }
1302
1303 return 0;
1304 }
1305
1306 static int mount_partition(
1307 DissectedPartition *m,
1308 const char *where,
1309 const char *directory,
1310 uid_t uid_shift,
1311 uid_t uid_range,
1312 DissectImageFlags flags) {
1313
1314 _cleanup_free_ char *chased = NULL, *options = NULL;
1315 const char *p, *node, *fstype;
1316 bool rw, remap_uid_gid = false;
1317 int r;
1318
1319 assert(m);
1320 assert(where);
1321
1322 /* Use decrypted node and matching fstype if available, otherwise use the original device */
1323 node = m->decrypted_node ?: m->node;
1324 fstype = m->decrypted_node ? m->decrypted_fstype: m->fstype;
1325
1326 if (!m->found || !node)
1327 return 0;
1328 if (!fstype)
1329 return -EAFNOSUPPORT;
1330
1331 /* We are looking at an encrypted partition? This either means stacked encryption, or the caller
1332 * didn't call dissected_image_decrypt() beforehand. Let's return a recognizable error for this
1333 * case. */
1334 if (streq(fstype, "crypto_LUKS"))
1335 return -EUNATCH;
1336
1337 rw = m->rw && !(flags & DISSECT_IMAGE_MOUNT_READ_ONLY);
1338
1339 if (FLAGS_SET(flags, DISSECT_IMAGE_FSCK) && rw) {
1340 r = run_fsck(node, fstype);
1341 if (r < 0)
1342 return r;
1343 }
1344
1345 if (directory) {
1346 /* Automatically create missing mount points inside the image, if necessary. */
1347 r = mkdir_p_root(where, directory, uid_shift, (gid_t) uid_shift, 0755);
1348 if (r < 0 && r != -EROFS)
1349 return r;
1350
1351 r = chase_symlinks(directory, where, CHASE_PREFIX_ROOT, &chased, NULL);
1352 if (r < 0)
1353 return r;
1354
1355 p = chased;
1356 } else {
1357 /* Create top-level mount if missing – but only if this is asked for. This won't modify the
1358 * image (as the branch above does) but the host hierarchy, and the created directory might
1359 * survive our mount in the host hierarchy hence. */
1360 if (FLAGS_SET(flags, DISSECT_IMAGE_MKDIR)) {
1361 r = mkdir_p(where, 0755);
1362 if (r < 0)
1363 return r;
1364 }
1365
1366 p = where;
1367 }
1368
1369 /* If requested, turn on discard support. */
1370 if (fstype_can_discard(fstype) &&
1371 ((flags & DISSECT_IMAGE_DISCARD) ||
1372 ((flags & DISSECT_IMAGE_DISCARD_ON_LOOP) && is_loop_device(m->node) > 0))) {
1373 options = strdup("discard");
1374 if (!options)
1375 return -ENOMEM;
1376 }
1377
1378 if (uid_is_valid(uid_shift) && uid_shift != 0) {
1379
1380 if (fstype_can_uid_gid(fstype)) {
1381 _cleanup_free_ char *uid_option = NULL;
1382
1383 if (asprintf(&uid_option, "uid=" UID_FMT ",gid=" GID_FMT, uid_shift, (gid_t) uid_shift) < 0)
1384 return -ENOMEM;
1385
1386 if (!strextend_with_separator(&options, ",", uid_option))
1387 return -ENOMEM;
1388 } else if (FLAGS_SET(flags, DISSECT_IMAGE_MOUNT_IDMAPPED))
1389 remap_uid_gid = true;
1390 }
1391
1392 if (!isempty(m->mount_options))
1393 if (!strextend_with_separator(&options, ",", m->mount_options))
1394 return -ENOMEM;
1395
1396 /* So, when you request MS_RDONLY from ext4, then this means nothing. It happily still writes to the
1397 * backing storage. What's worse, the BLKRO[GS]ET flag and (in case of loopback devices)
1398 * LO_FLAGS_READ_ONLY don't mean anything, they affect userspace accesses only, and write accesses
1399 * from the upper file system still get propagated through to the underlying file system,
1400 * unrestricted. To actually get ext4/xfs/btrfs to stop writing to the device we need to specify
1401 * "norecovery" as mount option, in addition to MS_RDONLY. Yes, this sucks, since it means we need to
1402 * carry a per file system table here.
1403 *
1404 * Note that this means that we might not be able to mount corrupted file systems as read-only
1405 * anymore (since in some cases the kernel implementations will refuse mounting when corrupted,
1406 * read-only and "norecovery" is specified). But I think for the case of automatically determined
1407 * mount options for loopback devices this is the right choice, since otherwise using the same
1408 * loopback file twice even in read-only mode, is going to fail badly sooner or later. The usecase of
1409 * making reuse of the immutable images "just work" is more relevant to us than having read-only
1410 * access that actually modifies stuff work on such image files. Or to say this differently: if
1411 * people want their file systems to be fixed up they should just open them in writable mode, where
1412 * all these problems don't exist. */
1413 if (!rw && STRPTR_IN_SET(fstype, "ext3", "ext4", "xfs", "btrfs"))
1414 if (!strextend_with_separator(&options, ",", "norecovery"))
1415 return -ENOMEM;
1416
1417 r = mount_nofollow_verbose(LOG_DEBUG, node, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options);
1418 if (r < 0)
1419 return r;
1420
1421 if (rw && m->growfs && FLAGS_SET(flags, DISSECT_IMAGE_GROWFS))
1422 (void) fs_grow(node, p);
1423
1424 if (remap_uid_gid) {
1425 r = remount_idmap(p, uid_shift, uid_range, UID_INVALID, REMOUNT_IDMAPPING_HOST_ROOT);
1426 if (r < 0)
1427 return r;
1428 }
1429
1430 return 1;
1431 }
1432
1433 static int mount_root_tmpfs(const char *where, uid_t uid_shift, DissectImageFlags flags) {
1434 _cleanup_free_ char *options = NULL;
1435 int r;
1436
1437 assert(where);
1438
1439 /* For images that contain /usr/ but no rootfs, let's mount rootfs as tmpfs */
1440
1441 if (FLAGS_SET(flags, DISSECT_IMAGE_MKDIR)) {
1442 r = mkdir_p(where, 0755);
1443 if (r < 0)
1444 return r;
1445 }
1446
1447 if (uid_is_valid(uid_shift)) {
1448 if (asprintf(&options, "uid=" UID_FMT ",gid=" GID_FMT, uid_shift, (gid_t) uid_shift) < 0)
1449 return -ENOMEM;
1450 }
1451
1452 r = mount_nofollow_verbose(LOG_DEBUG, "rootfs", where, "tmpfs", MS_NODEV, options);
1453 if (r < 0)
1454 return r;
1455
1456 return 1;
1457 }
1458
1459 int dissected_image_mount(
1460 DissectedImage *m,
1461 const char *where,
1462 uid_t uid_shift,
1463 uid_t uid_range,
1464 DissectImageFlags flags) {
1465
1466 int r, xbootldr_mounted;
1467
1468 assert(m);
1469 assert(where);
1470
1471 /* Returns:
1472 *
1473 * -ENXIO → No root partition found
1474 * -EMEDIUMTYPE → DISSECT_IMAGE_VALIDATE_OS set but no os-release/extension-release file found
1475 * -EUNATCH → Encrypted partition found for which no dm-crypt was set up yet
1476 * -EUCLEAN → fsck for file system failed
1477 * -EBUSY → File system already mounted/used elsewhere (kernel)
1478 * -EAFNOSUPPORT → File system type not supported or not known
1479 */
1480
1481 if (!(m->partitions[PARTITION_ROOT].found ||
1482 (m->partitions[PARTITION_USR].found && FLAGS_SET(flags, DISSECT_IMAGE_USR_NO_ROOT))))
1483 return -ENXIO; /* Require a root fs or at least a /usr/ fs (the latter is subject to a flag of its own) */
1484
1485 if ((flags & DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY) == 0) {
1486
1487 /* First mount the root fs. If there's none we use a tmpfs. */
1488 if (m->partitions[PARTITION_ROOT].found)
1489 r = mount_partition(m->partitions + PARTITION_ROOT, where, NULL, uid_shift, uid_range, flags);
1490 else
1491 r = mount_root_tmpfs(where, uid_shift, flags);
1492 if (r < 0)
1493 return r;
1494
1495 /* For us mounting root always means mounting /usr as well */
1496 r = mount_partition(m->partitions + PARTITION_USR, where, "/usr", uid_shift, uid_range, flags);
1497 if (r < 0)
1498 return r;
1499
1500 if ((flags & (DISSECT_IMAGE_VALIDATE_OS|DISSECT_IMAGE_VALIDATE_OS_EXT)) != 0) {
1501 /* If either one of the validation flags are set, ensure that the image qualifies
1502 * as one or the other (or both). */
1503 bool ok = false;
1504
1505 if (FLAGS_SET(flags, DISSECT_IMAGE_VALIDATE_OS)) {
1506 r = path_is_os_tree(where);
1507 if (r < 0)
1508 return r;
1509 if (r > 0)
1510 ok = true;
1511 }
1512 if (!ok && FLAGS_SET(flags, DISSECT_IMAGE_VALIDATE_OS_EXT)) {
1513 r = path_is_extension_tree(where, m->image_name);
1514 if (r < 0)
1515 return r;
1516 if (r > 0)
1517 ok = true;
1518 }
1519
1520 if (!ok)
1521 return -ENOMEDIUM;
1522 }
1523 }
1524
1525 if (flags & DISSECT_IMAGE_MOUNT_ROOT_ONLY)
1526 return 0;
1527
1528 r = mount_partition(m->partitions + PARTITION_HOME, where, "/home", uid_shift, uid_range, flags);
1529 if (r < 0)
1530 return r;
1531
1532 r = mount_partition(m->partitions + PARTITION_SRV, where, "/srv", uid_shift, uid_range, flags);
1533 if (r < 0)
1534 return r;
1535
1536 r = mount_partition(m->partitions + PARTITION_VAR, where, "/var", uid_shift, uid_range, flags);
1537 if (r < 0)
1538 return r;
1539
1540 r = mount_partition(m->partitions + PARTITION_TMP, where, "/var/tmp", uid_shift, uid_range, flags);
1541 if (r < 0)
1542 return r;
1543
1544 xbootldr_mounted = mount_partition(m->partitions + PARTITION_XBOOTLDR, where, "/boot", uid_shift, uid_range, flags);
1545 if (xbootldr_mounted < 0)
1546 return xbootldr_mounted;
1547
1548 if (m->partitions[PARTITION_ESP].found) {
1549 int esp_done = false;
1550
1551 /* Mount the ESP to /efi if it exists. If it doesn't exist, use /boot instead, but only if it
1552 * exists and is empty, and we didn't already mount the XBOOTLDR partition into it. */
1553
1554 r = chase_symlinks("/efi", where, CHASE_PREFIX_ROOT, NULL, NULL);
1555 if (r < 0) {
1556 if (r != -ENOENT)
1557 return r;
1558
1559 /* /efi doesn't exist. Let's see if /boot is suitable then */
1560
1561 if (!xbootldr_mounted) {
1562 _cleanup_free_ char *p = NULL;
1563
1564 r = chase_symlinks("/boot", where, CHASE_PREFIX_ROOT, &p, NULL);
1565 if (r < 0) {
1566 if (r != -ENOENT)
1567 return r;
1568 } else if (dir_is_empty(p, /* ignore_hidden_or_backup= */ false) > 0) {
1569 /* It exists and is an empty directory. Let's mount the ESP there. */
1570 r = mount_partition(m->partitions + PARTITION_ESP, where, "/boot", uid_shift, uid_range, flags);
1571 if (r < 0)
1572 return r;
1573
1574 esp_done = true;
1575 }
1576 }
1577 }
1578
1579 if (!esp_done) {
1580 /* OK, let's mount the ESP now to /efi (possibly creating the dir if missing) */
1581
1582 r = mount_partition(m->partitions + PARTITION_ESP, where, "/efi", uid_shift, uid_range, flags);
1583 if (r < 0)
1584 return r;
1585 }
1586 }
1587
1588 return 0;
1589 }
1590
1591 int dissected_image_mount_and_warn(
1592 DissectedImage *m,
1593 const char *where,
1594 uid_t uid_shift,
1595 uid_t uid_range,
1596 DissectImageFlags flags) {
1597
1598 int r;
1599
1600 assert(m);
1601 assert(where);
1602
1603 r = dissected_image_mount(m, where, uid_shift, uid_range, flags);
1604 if (r == -ENXIO)
1605 return log_error_errno(r, "Not root file system found in image.");
1606 if (r == -EMEDIUMTYPE)
1607 return log_error_errno(r, "No suitable os-release/extension-release file in image found.");
1608 if (r == -EUNATCH)
1609 return log_error_errno(r, "Encrypted file system discovered, but decryption not requested.");
1610 if (r == -EUCLEAN)
1611 return log_error_errno(r, "File system check on image failed.");
1612 if (r == -EBUSY)
1613 return log_error_errno(r, "File system already mounted elsewhere.");
1614 if (r == -EAFNOSUPPORT)
1615 return log_error_errno(r, "File system type not supported or not known.");
1616 if (r < 0)
1617 return log_error_errno(r, "Failed to mount image: %m");
1618
1619 return r;
1620 }
1621
1622 #if HAVE_LIBCRYPTSETUP
1623 struct DecryptedPartition {
1624 struct crypt_device *device;
1625 char *name;
1626 bool relinquished;
1627 };
1628 #endif
1629
1630 typedef struct DecryptedPartition DecryptedPartition;
1631
1632 struct DecryptedImage {
1633 unsigned n_ref;
1634 DecryptedPartition *decrypted;
1635 size_t n_decrypted;
1636 };
1637
1638 static DecryptedImage* decrypted_image_free(DecryptedImage *d) {
1639 #if HAVE_LIBCRYPTSETUP
1640 int r;
1641
1642 if (!d)
1643 return NULL;
1644
1645 for (size_t i = 0; i < d->n_decrypted; i++) {
1646 DecryptedPartition *p = d->decrypted + i;
1647
1648 if (p->device && p->name && !p->relinquished) {
1649 /* Let's deactivate lazily, as the dm volume may be already/still used by other processes. */
1650 r = sym_crypt_deactivate_by_name(p->device, p->name, CRYPT_DEACTIVATE_DEFERRED);
1651 if (r < 0)
1652 log_debug_errno(r, "Failed to deactivate encrypted partition %s", p->name);
1653 }
1654
1655 if (p->device)
1656 sym_crypt_free(p->device);
1657 free(p->name);
1658 }
1659
1660 free(d->decrypted);
1661 free(d);
1662 #endif
1663 return NULL;
1664 }
1665
1666 DEFINE_TRIVIAL_REF_UNREF_FUNC(DecryptedImage, decrypted_image, decrypted_image_free);
1667
1668 #if HAVE_LIBCRYPTSETUP
1669 static int decrypted_image_new(DecryptedImage **ret) {
1670 _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL;
1671
1672 assert(ret);
1673
1674 d = new(DecryptedImage, 1);
1675 if (!d)
1676 return -ENOMEM;
1677
1678 *d = (DecryptedImage) {
1679 .n_ref = 1,
1680 };
1681
1682 *ret = TAKE_PTR(d);
1683 return 0;
1684 }
1685
1686 static int make_dm_name_and_node(const void *original_node, const char *suffix, char **ret_name, char **ret_node) {
1687 _cleanup_free_ char *name = NULL, *node = NULL;
1688 const char *base;
1689
1690 assert(original_node);
1691 assert(suffix);
1692 assert(ret_name);
1693 assert(ret_node);
1694
1695 base = strrchr(original_node, '/');
1696 if (!base)
1697 base = original_node;
1698 else
1699 base++;
1700 if (isempty(base))
1701 return -EINVAL;
1702
1703 name = strjoin(base, suffix);
1704 if (!name)
1705 return -ENOMEM;
1706 if (!filename_is_valid(name))
1707 return -EINVAL;
1708
1709 node = path_join(sym_crypt_get_dir(), name);
1710 if (!node)
1711 return -ENOMEM;
1712
1713 *ret_name = TAKE_PTR(name);
1714 *ret_node = TAKE_PTR(node);
1715
1716 return 0;
1717 }
1718
1719 static int decrypt_partition(
1720 DissectedPartition *m,
1721 const char *passphrase,
1722 DissectImageFlags flags,
1723 DecryptedImage *d) {
1724
1725 _cleanup_free_ char *node = NULL, *name = NULL;
1726 _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
1727 int r;
1728
1729 assert(m);
1730 assert(d);
1731
1732 if (!m->found || !m->node || !m->fstype)
1733 return 0;
1734
1735 if (!streq(m->fstype, "crypto_LUKS"))
1736 return 0;
1737
1738 if (!passphrase)
1739 return -ENOKEY;
1740
1741 r = dlopen_cryptsetup();
1742 if (r < 0)
1743 return r;
1744
1745 r = make_dm_name_and_node(m->node, "-decrypted", &name, &node);
1746 if (r < 0)
1747 return r;
1748
1749 if (!GREEDY_REALLOC0(d->decrypted, d->n_decrypted + 1))
1750 return -ENOMEM;
1751
1752 r = sym_crypt_init(&cd, m->node);
1753 if (r < 0)
1754 return log_debug_errno(r, "Failed to initialize dm-crypt: %m");
1755
1756 cryptsetup_enable_logging(cd);
1757
1758 r = sym_crypt_load(cd, CRYPT_LUKS, NULL);
1759 if (r < 0)
1760 return log_debug_errno(r, "Failed to load LUKS metadata: %m");
1761
1762 r = sym_crypt_activate_by_passphrase(cd, name, CRYPT_ANY_SLOT, passphrase, strlen(passphrase),
1763 ((flags & DISSECT_IMAGE_DEVICE_READ_ONLY) ? CRYPT_ACTIVATE_READONLY : 0) |
1764 ((flags & DISSECT_IMAGE_DISCARD_ON_CRYPTO) ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0));
1765 if (r < 0) {
1766 log_debug_errno(r, "Failed to activate LUKS device: %m");
1767 return r == -EPERM ? -EKEYREJECTED : r;
1768 }
1769
1770 d->decrypted[d->n_decrypted++] = (DecryptedPartition) {
1771 .name = TAKE_PTR(name),
1772 .device = TAKE_PTR(cd),
1773 };
1774
1775 m->decrypted_node = TAKE_PTR(node);
1776
1777 return 0;
1778 }
1779
1780 static int verity_can_reuse(
1781 const VeritySettings *verity,
1782 const char *name,
1783 struct crypt_device **ret_cd) {
1784
1785 /* If the same volume was already open, check that the root hashes match, and reuse it if they do */
1786 _cleanup_free_ char *root_hash_existing = NULL;
1787 _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
1788 struct crypt_params_verity crypt_params = {};
1789 size_t root_hash_existing_size;
1790 int r;
1791
1792 assert(verity);
1793 assert(name);
1794 assert(ret_cd);
1795
1796 r = sym_crypt_init_by_name(&cd, name);
1797 if (r < 0)
1798 return log_debug_errno(r, "Error opening verity device, crypt_init_by_name failed: %m");
1799
1800 cryptsetup_enable_logging(cd);
1801
1802 r = sym_crypt_get_verity_info(cd, &crypt_params);
1803 if (r < 0)
1804 return log_debug_errno(r, "Error opening verity device, crypt_get_verity_info failed: %m");
1805
1806 root_hash_existing_size = verity->root_hash_size;
1807 root_hash_existing = malloc0(root_hash_existing_size);
1808 if (!root_hash_existing)
1809 return -ENOMEM;
1810
1811 r = sym_crypt_volume_key_get(cd, CRYPT_ANY_SLOT, root_hash_existing, &root_hash_existing_size, NULL, 0);
1812 if (r < 0)
1813 return log_debug_errno(r, "Error opening verity device, crypt_volume_key_get failed: %m");
1814 if (verity->root_hash_size != root_hash_existing_size ||
1815 memcmp(root_hash_existing, verity->root_hash, verity->root_hash_size) != 0)
1816 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Error opening verity device, it already exists but root hashes are different.");
1817
1818 #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
1819 /* Ensure that, if signatures are supported, we only reuse the device if the previous mount used the
1820 * same settings, so that a previous unsigned mount will not be reused if the user asks to use
1821 * signing for the new one, and vice versa. */
1822 if (!!verity->root_hash_sig != !!(crypt_params.flags & CRYPT_VERITY_ROOT_HASH_SIGNATURE))
1823 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Error opening verity device, it already exists but signature settings are not the same.");
1824 #endif
1825
1826 *ret_cd = TAKE_PTR(cd);
1827 return 0;
1828 }
1829
1830 static inline char* dm_deferred_remove_clean(char *name) {
1831 if (!name)
1832 return NULL;
1833
1834 (void) sym_crypt_deactivate_by_name(NULL, name, CRYPT_DEACTIVATE_DEFERRED);
1835 return mfree(name);
1836 }
1837 DEFINE_TRIVIAL_CLEANUP_FUNC(char *, dm_deferred_remove_clean);
1838
1839 static int validate_signature_userspace(const VeritySettings *verity) {
1840 #if HAVE_OPENSSL
1841 _cleanup_(sk_X509_free_allp) STACK_OF(X509) *sk = NULL;
1842 _cleanup_strv_free_ char **certs = NULL;
1843 _cleanup_(PKCS7_freep) PKCS7 *p7 = NULL;
1844 _cleanup_free_ char *s = NULL;
1845 _cleanup_(BIO_freep) BIO *bio = NULL; /* 'bio' must be freed first, 's' second, hence keep this order
1846 * of declaration in place, please */
1847 const unsigned char *d;
1848 int r;
1849
1850 assert(verity);
1851 assert(verity->root_hash);
1852 assert(verity->root_hash_sig);
1853
1854 /* Because installing a signature certificate into the kernel chain is so messy, let's optionally do
1855 * userspace validation. */
1856
1857 r = conf_files_list_nulstr(&certs, ".crt", NULL, CONF_FILES_REGULAR|CONF_FILES_FILTER_MASKED, CONF_PATHS_NULSTR("verity.d"));
1858 if (r < 0)
1859 return log_debug_errno(r, "Failed to enumerate certificates: %m");
1860 if (strv_isempty(certs)) {
1861 log_debug("No userspace dm-verity certificates found.");
1862 return 0;
1863 }
1864
1865 d = verity->root_hash_sig;
1866 p7 = d2i_PKCS7(NULL, &d, (long) verity->root_hash_sig_size);
1867 if (!p7)
1868 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse PKCS7 DER signature data.");
1869
1870 s = hexmem(verity->root_hash, verity->root_hash_size);
1871 if (!s)
1872 return log_oom_debug();
1873
1874 bio = BIO_new_mem_buf(s, strlen(s));
1875 if (!bio)
1876 return log_oom_debug();
1877
1878 sk = sk_X509_new_null();
1879 if (!sk)
1880 return log_oom_debug();
1881
1882 STRV_FOREACH(i, certs) {
1883 _cleanup_(X509_freep) X509 *c = NULL;
1884 _cleanup_fclose_ FILE *f = NULL;
1885
1886 f = fopen(*i, "re");
1887 if (!f) {
1888 log_debug_errno(errno, "Failed to open '%s', ignoring: %m", *i);
1889 continue;
1890 }
1891
1892 c = PEM_read_X509(f, NULL, NULL, NULL);
1893 if (!c) {
1894 log_debug("Failed to load X509 certificate '%s', ignoring.", *i);
1895 continue;
1896 }
1897
1898 if (sk_X509_push(sk, c) == 0)
1899 return log_oom_debug();
1900
1901 TAKE_PTR(c);
1902 }
1903
1904 r = PKCS7_verify(p7, sk, NULL, bio, NULL, PKCS7_NOINTERN|PKCS7_NOVERIFY);
1905 if (r)
1906 log_debug("Userspace PKCS#7 validation succeeded.");
1907 else
1908 log_debug("Userspace PKCS#7 validation failed: %s", ERR_error_string(ERR_get_error(), NULL));
1909
1910 return r;
1911 #else
1912 log_debug("Not doing client-side validation of dm-verity root hash signatures, OpenSSL support disabled.");
1913 return 0;
1914 #endif
1915 }
1916
1917 static int do_crypt_activate_verity(
1918 struct crypt_device *cd,
1919 const char *name,
1920 const VeritySettings *verity) {
1921
1922 bool check_signature;
1923 int r;
1924
1925 assert(cd);
1926 assert(name);
1927 assert(verity);
1928
1929 if (verity->root_hash_sig) {
1930 r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_SIGNATURE");
1931 if (r < 0 && r != -ENXIO)
1932 log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_SIGNATURE");
1933
1934 check_signature = r != 0;
1935 } else
1936 check_signature = false;
1937
1938 if (check_signature) {
1939
1940 #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
1941 /* First, if we have support for signed keys in the kernel, then try that first. */
1942 r = sym_crypt_activate_by_signed_key(
1943 cd,
1944 name,
1945 verity->root_hash,
1946 verity->root_hash_size,
1947 verity->root_hash_sig,
1948 verity->root_hash_sig_size,
1949 CRYPT_ACTIVATE_READONLY);
1950 if (r >= 0)
1951 return r;
1952
1953 log_debug("Validation of dm-verity signature failed via the kernel, trying userspace validation instead.");
1954 #else
1955 log_debug("Activation of verity device with signature requested, but not supported via the kernel by %s due to missing crypt_activate_by_signed_key(), trying userspace validation instead.",
1956 program_invocation_short_name);
1957 #endif
1958
1959 /* So this didn't work via the kernel, then let's try userspace validation instead. If that
1960 * works we'll try to activate without telling the kernel the signature. */
1961
1962 r = validate_signature_userspace(verity);
1963 if (r < 0)
1964 return r;
1965 if (r == 0)
1966 return log_debug_errno(SYNTHETIC_ERRNO(ENOKEY),
1967 "Activation of signed Verity volume worked neither via the kernel nor in userspace, can't activate.");
1968 }
1969
1970 return sym_crypt_activate_by_volume_key(
1971 cd,
1972 name,
1973 verity->root_hash,
1974 verity->root_hash_size,
1975 CRYPT_ACTIVATE_READONLY);
1976 }
1977
1978 static usec_t verity_timeout(void) {
1979 usec_t t = 100 * USEC_PER_MSEC;
1980 const char *e;
1981 int r;
1982
1983 /* On slower machines, like non-KVM vm, setting up device may take a long time.
1984 * Let's make the timeout configurable. */
1985
1986 e = getenv("SYSTEMD_DISSECT_VERITY_TIMEOUT_SEC");
1987 if (!e)
1988 return t;
1989
1990 r = parse_sec(e, &t);
1991 if (r < 0)
1992 log_debug_errno(r,
1993 "Failed to parse timeout specified in $SYSTEMD_DISSECT_VERITY_TIMEOUT_SEC, "
1994 "using the default timeout (%s).",
1995 FORMAT_TIMESPAN(t, USEC_PER_MSEC));
1996
1997 return t;
1998 }
1999
2000 static int verity_partition(
2001 PartitionDesignator designator,
2002 DissectedPartition *m,
2003 DissectedPartition *v,
2004 const VeritySettings *verity,
2005 DissectImageFlags flags,
2006 DecryptedImage *d) {
2007
2008 _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
2009 _cleanup_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL;
2010 _cleanup_free_ char *node = NULL, *name = NULL;
2011 int r;
2012
2013 assert(m);
2014 assert(v || (verity && verity->data_path));
2015
2016 if (!verity || !verity->root_hash)
2017 return 0;
2018 if (!((verity->designator < 0 && designator == PARTITION_ROOT) ||
2019 (verity->designator == designator)))
2020 return 0;
2021
2022 if (!m->found || !m->node || !m->fstype)
2023 return 0;
2024 if (!verity->data_path) {
2025 if (!v->found || !v->node || !v->fstype)
2026 return 0;
2027
2028 if (!streq(v->fstype, "DM_verity_hash"))
2029 return 0;
2030 }
2031
2032 r = dlopen_cryptsetup();
2033 if (r < 0)
2034 return r;
2035
2036 if (FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE)) {
2037 /* Use the roothash, which is unique per volume, as the device node name, so that it can be reused */
2038 _cleanup_free_ char *root_hash_encoded = NULL;
2039
2040 root_hash_encoded = hexmem(verity->root_hash, verity->root_hash_size);
2041 if (!root_hash_encoded)
2042 return -ENOMEM;
2043
2044 r = make_dm_name_and_node(root_hash_encoded, "-verity", &name, &node);
2045 } else
2046 r = make_dm_name_and_node(m->node, "-verity", &name, &node);
2047 if (r < 0)
2048 return r;
2049
2050 r = sym_crypt_init(&cd, verity->data_path ?: v->node);
2051 if (r < 0)
2052 return r;
2053
2054 cryptsetup_enable_logging(cd);
2055
2056 r = sym_crypt_load(cd, CRYPT_VERITY, NULL);
2057 if (r < 0)
2058 return r;
2059
2060 r = sym_crypt_set_data_device(cd, m->node);
2061 if (r < 0)
2062 return r;
2063
2064 if (!GREEDY_REALLOC0(d->decrypted, d->n_decrypted + 1))
2065 return -ENOMEM;
2066
2067 /* If activating fails because the device already exists, check the metadata and reuse it if it matches.
2068 * In case of ENODEV/ENOENT, which can happen if another process is activating at the exact same time,
2069 * retry a few times before giving up. */
2070 for (unsigned i = 0; i < N_DEVICE_NODE_LIST_ATTEMPTS; i++) {
2071
2072 r = do_crypt_activate_verity(cd, name, verity);
2073 /* libdevmapper can return EINVAL when the device is already in the activation stage.
2074 * There's no way to distinguish this situation from a genuine error due to invalid
2075 * parameters, so immediately fall back to activating the device with a unique name.
2076 * Improvements in libcrypsetup can ensure this never happens:
2077 * https://gitlab.com/cryptsetup/cryptsetup/-/merge_requests/96 */
2078 if (r == -EINVAL && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
2079 break;
2080 if (r < 0 && !IN_SET(r,
2081 -EEXIST, /* Volume is already open and ready to be used */
2082 -EBUSY, /* Volume is being opened but not ready, crypt_init_by_name can fetch details */
2083 -ENODEV /* Volume is being opened but not ready, crypt_init_by_name would fail, try to open again */))
2084 return r;
2085 if (IN_SET(r, -EEXIST, -EBUSY)) {
2086 _cleanup_(sym_crypt_freep) struct crypt_device *existing_cd = NULL;
2087
2088 if (!restore_deferred_remove){
2089 /* To avoid races, disable automatic removal on umount while setting up the new device. Restore it on failure. */
2090 r = dm_deferred_remove_cancel(name);
2091 /* If activation returns EBUSY there might be no deferred removal to cancel, that's fine */
2092 if (r < 0 && r != -ENXIO)
2093 return log_debug_errno(r, "Disabling automated deferred removal for verity device %s failed: %m", node);
2094 if (r >= 0) {
2095 restore_deferred_remove = strdup(name);
2096 if (!restore_deferred_remove)
2097 return -ENOMEM;
2098 }
2099 }
2100
2101 r = verity_can_reuse(verity, name, &existing_cd);
2102 /* Same as above, -EINVAL can randomly happen when it actually means -EEXIST */
2103 if (r == -EINVAL && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
2104 break;
2105 if (r < 0 && !IN_SET(r, -ENODEV, -ENOENT, -EBUSY))
2106 return log_debug_errno(r, "Checking whether existing verity device %s can be reused failed: %m", node);
2107 if (r >= 0) {
2108 /* devmapper might say that the device exists, but the devlink might not yet have been
2109 * created. Check and wait for the udev event in that case. */
2110 r = device_wait_for_devlink(node, "block", verity_timeout(), NULL);
2111 /* Fallback to activation with a unique device if it's taking too long */
2112 if (r == -ETIMEDOUT && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
2113 break;
2114 if (r < 0)
2115 return r;
2116
2117 crypt_free_and_replace(cd, existing_cd);
2118 }
2119 }
2120 if (r >= 0)
2121 goto success;
2122
2123 /* Device is being opened by another process, but it has not finished yet, yield for 2ms */
2124 (void) usleep(2 * USEC_PER_MSEC);
2125 }
2126
2127 /* All trials failed or a conflicting verity device exists. Let's try to activate with a unique name. */
2128 if (FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE)) {
2129 /* Before trying to activate with unique name, we need to free crypt_device object.
2130 * Otherwise, we get error from libcryptsetup like the following:
2131 * ------
2132 * systemd[1234]: Cannot use device /dev/loop5 which is in use (already mapped or mounted).
2133 * ------
2134 */
2135 sym_crypt_free(cd);
2136 cd = NULL;
2137 return verity_partition(designator, m, v, verity, flags & ~DISSECT_IMAGE_VERITY_SHARE, d);
2138 }
2139
2140 return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), "All attempts to activate verity device %s failed.", name);
2141
2142 success:
2143 /* Everything looks good and we'll be able to mount the device, so deferred remove will be re-enabled at that point. */
2144 restore_deferred_remove = mfree(restore_deferred_remove);
2145
2146 d->decrypted[d->n_decrypted++] = (DecryptedPartition) {
2147 .name = TAKE_PTR(name),
2148 .device = TAKE_PTR(cd),
2149 };
2150
2151 m->decrypted_node = TAKE_PTR(node);
2152
2153 return 0;
2154 }
2155 #endif
2156
2157 int dissected_image_decrypt(
2158 DissectedImage *m,
2159 const char *passphrase,
2160 const VeritySettings *verity,
2161 DissectImageFlags flags) {
2162
2163 #if HAVE_LIBCRYPTSETUP
2164 _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL;
2165 int r;
2166 #endif
2167
2168 assert(m);
2169 assert(!verity || verity->root_hash || verity->root_hash_size == 0);
2170
2171 /* Returns:
2172 *
2173 * = 0 → There was nothing to decrypt
2174 * > 0 → Decrypted successfully
2175 * -ENOKEY → There's something to decrypt but no key was supplied
2176 * -EKEYREJECTED → Passed key was not correct
2177 */
2178
2179 if (verity && verity->root_hash && verity->root_hash_size < sizeof(sd_id128_t))
2180 return -EINVAL;
2181
2182 if (!m->encrypted && !m->verity_ready)
2183 return 0;
2184
2185 #if HAVE_LIBCRYPTSETUP
2186 r = decrypted_image_new(&d);
2187 if (r < 0)
2188 return r;
2189
2190 for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
2191 DissectedPartition *p = m->partitions + i;
2192 PartitionDesignator k;
2193
2194 if (!p->found)
2195 continue;
2196
2197 r = decrypt_partition(p, passphrase, flags, d);
2198 if (r < 0)
2199 return r;
2200
2201 k = PARTITION_VERITY_OF(i);
2202 if (k >= 0) {
2203 r = verity_partition(i, p, m->partitions + k, verity, flags | DISSECT_IMAGE_VERITY_SHARE, d);
2204 if (r < 0)
2205 return r;
2206 }
2207
2208 if (!p->decrypted_fstype && p->decrypted_node) {
2209 r = probe_filesystem(p->decrypted_node, &p->decrypted_fstype);
2210 if (r < 0 && r != -EUCLEAN)
2211 return r;
2212 }
2213 }
2214
2215 m->decrypted_image = TAKE_PTR(d);
2216
2217 return 1;
2218 #else
2219 return -EOPNOTSUPP;
2220 #endif
2221 }
2222
2223 int dissected_image_decrypt_interactively(
2224 DissectedImage *m,
2225 const char *passphrase,
2226 const VeritySettings *verity,
2227 DissectImageFlags flags) {
2228
2229 _cleanup_strv_free_erase_ char **z = NULL;
2230 int n = 3, r;
2231
2232 if (passphrase)
2233 n--;
2234
2235 for (;;) {
2236 r = dissected_image_decrypt(m, passphrase, verity, flags);
2237 if (r >= 0)
2238 return r;
2239 if (r == -EKEYREJECTED)
2240 log_error_errno(r, "Incorrect passphrase, try again!");
2241 else if (r != -ENOKEY)
2242 return log_error_errno(r, "Failed to decrypt image: %m");
2243
2244 if (--n < 0)
2245 return log_error_errno(SYNTHETIC_ERRNO(EKEYREJECTED),
2246 "Too many retries.");
2247
2248 z = strv_free(z);
2249
2250 r = ask_password_auto("Please enter image passphrase:", NULL, "dissect", "dissect", "dissect.passphrase", USEC_INFINITY, 0, &z);
2251 if (r < 0)
2252 return log_error_errno(r, "Failed to query for passphrase: %m");
2253
2254 passphrase = z[0];
2255 }
2256 }
2257
2258 static int decrypted_image_relinquish(DecryptedImage *d) {
2259 assert(d);
2260
2261 /* Turns on automatic removal after the last use ended for all DM devices of this image, and sets a
2262 * boolean so that we don't clean it up ourselves either anymore */
2263
2264 #if HAVE_LIBCRYPTSETUP
2265 int r;
2266
2267 for (size_t i = 0; i < d->n_decrypted; i++) {
2268 DecryptedPartition *p = d->decrypted + i;
2269
2270 if (p->relinquished)
2271 continue;
2272
2273 r = sym_crypt_deactivate_by_name(NULL, p->name, CRYPT_DEACTIVATE_DEFERRED);
2274 if (r < 0)
2275 return log_debug_errno(r, "Failed to mark %s for auto-removal: %m", p->name);
2276
2277 p->relinquished = true;
2278 }
2279 #endif
2280
2281 return 0;
2282 }
2283
2284 int dissected_image_relinquish(DissectedImage *m) {
2285 int r;
2286
2287 assert(m);
2288
2289 if (m->decrypted_image) {
2290 r = decrypted_image_relinquish(m->decrypted_image);
2291 if (r < 0)
2292 return r;
2293 }
2294
2295 if (m->loop)
2296 loop_device_relinquish(m->loop);
2297
2298 return 0;
2299 }
2300
2301 static char *build_auxiliary_path(const char *image, const char *suffix) {
2302 const char *e;
2303 char *n;
2304
2305 assert(image);
2306 assert(suffix);
2307
2308 e = endswith(image, ".raw");
2309 if (!e)
2310 return strjoin(e, suffix);
2311
2312 n = new(char, e - image + strlen(suffix) + 1);
2313 if (!n)
2314 return NULL;
2315
2316 strcpy(mempcpy(n, image, e - image), suffix);
2317 return n;
2318 }
2319
2320 void verity_settings_done(VeritySettings *v) {
2321 assert(v);
2322
2323 v->root_hash = mfree(v->root_hash);
2324 v->root_hash_size = 0;
2325
2326 v->root_hash_sig = mfree(v->root_hash_sig);
2327 v->root_hash_sig_size = 0;
2328
2329 v->data_path = mfree(v->data_path);
2330 }
2331
2332 int verity_settings_load(
2333 VeritySettings *verity,
2334 const char *image,
2335 const char *root_hash_path,
2336 const char *root_hash_sig_path) {
2337
2338 _cleanup_free_ void *root_hash = NULL, *root_hash_sig = NULL;
2339 size_t root_hash_size = 0, root_hash_sig_size = 0;
2340 _cleanup_free_ char *verity_data_path = NULL;
2341 PartitionDesignator designator;
2342 int r;
2343
2344 assert(verity);
2345 assert(image);
2346 assert(verity->designator < 0 || IN_SET(verity->designator, PARTITION_ROOT, PARTITION_USR));
2347
2348 /* If we are asked to load the root hash for a device node, exit early */
2349 if (is_device_path(image))
2350 return 0;
2351
2352 r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_SIDECAR");
2353 if (r < 0 && r != -ENXIO)
2354 log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_SIDECAR, ignoring: %m");
2355 if (r == 0)
2356 return 0;
2357
2358 designator = verity->designator;
2359
2360 /* We only fill in what isn't already filled in */
2361
2362 if (!verity->root_hash) {
2363 _cleanup_free_ char *text = NULL;
2364
2365 if (root_hash_path) {
2366 /* If explicitly specified it takes precedence */
2367 r = read_one_line_file(root_hash_path, &text);
2368 if (r < 0)
2369 return r;
2370
2371 if (designator < 0)
2372 designator = PARTITION_ROOT;
2373 } else {
2374 /* Otherwise look for xattr and separate file, and first for the data for root and if
2375 * that doesn't exist for /usr */
2376
2377 if (designator < 0 || designator == PARTITION_ROOT) {
2378 r = getxattr_malloc(image, "user.verity.roothash", &text);
2379 if (r < 0) {
2380 _cleanup_free_ char *p = NULL;
2381
2382 if (r != -ENOENT && !ERRNO_IS_XATTR_ABSENT(r))
2383 return r;
2384
2385 p = build_auxiliary_path(image, ".roothash");
2386 if (!p)
2387 return -ENOMEM;
2388
2389 r = read_one_line_file(p, &text);
2390 if (r < 0 && r != -ENOENT)
2391 return r;
2392 }
2393
2394 if (text)
2395 designator = PARTITION_ROOT;
2396 }
2397
2398 if (!text && (designator < 0 || designator == PARTITION_USR)) {
2399 /* So in the "roothash" xattr/file name above the "root" of course primarily
2400 * refers to the root of the Verity Merkle tree. But coincidentally it also
2401 * is the hash for the *root* file system, i.e. the "root" neatly refers to
2402 * two distinct concepts called "root". Taking benefit of this happy
2403 * coincidence we call the file with the root hash for the /usr/ file system
2404 * `usrhash`, because `usrroothash` or `rootusrhash` would just be too
2405 * confusing. We thus drop the reference to the root of the Merkle tree, and
2406 * just indicate which file system it's about. */
2407 r = getxattr_malloc(image, "user.verity.usrhash", &text);
2408 if (r < 0) {
2409 _cleanup_free_ char *p = NULL;
2410
2411 if (r != -ENOENT && !ERRNO_IS_XATTR_ABSENT(r))
2412 return r;
2413
2414 p = build_auxiliary_path(image, ".usrhash");
2415 if (!p)
2416 return -ENOMEM;
2417
2418 r = read_one_line_file(p, &text);
2419 if (r < 0 && r != -ENOENT)
2420 return r;
2421 }
2422
2423 if (text)
2424 designator = PARTITION_USR;
2425 }
2426 }
2427
2428 if (text) {
2429 r = unhexmem(text, strlen(text), &root_hash, &root_hash_size);
2430 if (r < 0)
2431 return r;
2432 if (root_hash_size < sizeof(sd_id128_t))
2433 return -EINVAL;
2434 }
2435 }
2436
2437 if ((root_hash || verity->root_hash) && !verity->root_hash_sig) {
2438 if (root_hash_sig_path) {
2439 r = read_full_file(root_hash_sig_path, (char**) &root_hash_sig, &root_hash_sig_size);
2440 if (r < 0 && r != -ENOENT)
2441 return r;
2442
2443 if (designator < 0)
2444 designator = PARTITION_ROOT;
2445 } else {
2446 if (designator < 0 || designator == PARTITION_ROOT) {
2447 _cleanup_free_ char *p = NULL;
2448
2449 /* Follow naming convention recommended by the relevant RFC:
2450 * https://tools.ietf.org/html/rfc5751#section-3.2.1 */
2451 p = build_auxiliary_path(image, ".roothash.p7s");
2452 if (!p)
2453 return -ENOMEM;
2454
2455 r = read_full_file(p, (char**) &root_hash_sig, &root_hash_sig_size);
2456 if (r < 0 && r != -ENOENT)
2457 return r;
2458 if (r >= 0)
2459 designator = PARTITION_ROOT;
2460 }
2461
2462 if (!root_hash_sig && (designator < 0 || designator == PARTITION_USR)) {
2463 _cleanup_free_ char *p = NULL;
2464
2465 p = build_auxiliary_path(image, ".usrhash.p7s");
2466 if (!p)
2467 return -ENOMEM;
2468
2469 r = read_full_file(p, (char**) &root_hash_sig, &root_hash_sig_size);
2470 if (r < 0 && r != -ENOENT)
2471 return r;
2472 if (r >= 0)
2473 designator = PARTITION_USR;
2474 }
2475 }
2476
2477 if (root_hash_sig && root_hash_sig_size == 0) /* refuse empty size signatures */
2478 return -EINVAL;
2479 }
2480
2481 if (!verity->data_path) {
2482 _cleanup_free_ char *p = NULL;
2483
2484 p = build_auxiliary_path(image, ".verity");
2485 if (!p)
2486 return -ENOMEM;
2487
2488 if (access(p, F_OK) < 0) {
2489 if (errno != ENOENT)
2490 return -errno;
2491 } else
2492 verity_data_path = TAKE_PTR(p);
2493 }
2494
2495 if (root_hash) {
2496 verity->root_hash = TAKE_PTR(root_hash);
2497 verity->root_hash_size = root_hash_size;
2498 }
2499
2500 if (root_hash_sig) {
2501 verity->root_hash_sig = TAKE_PTR(root_hash_sig);
2502 verity->root_hash_sig_size = root_hash_sig_size;
2503 }
2504
2505 if (verity_data_path)
2506 verity->data_path = TAKE_PTR(verity_data_path);
2507
2508 if (verity->designator < 0)
2509 verity->designator = designator;
2510
2511 return 1;
2512 }
2513
2514 int dissected_image_load_verity_sig_partition(
2515 DissectedImage *m,
2516 int fd,
2517 VeritySettings *verity) {
2518
2519 _cleanup_free_ void *root_hash = NULL, *root_hash_sig = NULL;
2520 _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
2521 size_t root_hash_size, root_hash_sig_size;
2522 _cleanup_free_ char *buf = NULL;
2523 PartitionDesignator d;
2524 DissectedPartition *p;
2525 JsonVariant *rh, *sig;
2526 ssize_t n;
2527 char *e;
2528 int r;
2529
2530 assert(m);
2531 assert(fd >= 0);
2532 assert(verity);
2533
2534 if (verity->root_hash && verity->root_hash_sig) /* Already loaded? */
2535 return 0;
2536
2537 r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_EMBEDDED");
2538 if (r < 0 && r != -ENXIO)
2539 log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_EMBEDDED, ignoring: %m");
2540 if (r == 0)
2541 return 0;
2542
2543 d = PARTITION_VERITY_SIG_OF(verity->designator < 0 ? PARTITION_ROOT : verity->designator);
2544 assert(d >= 0);
2545
2546 p = m->partitions + d;
2547 if (!p->found)
2548 return 0;
2549 if (p->offset == UINT64_MAX || p->size == UINT64_MAX)
2550 return -EINVAL;
2551
2552 if (p->size > 4*1024*1024) /* Signature data cannot possible be larger than 4M, refuse that */
2553 return -EFBIG;
2554
2555 buf = new(char, p->size+1);
2556 if (!buf)
2557 return -ENOMEM;
2558
2559 n = pread(fd, buf, p->size, p->offset);
2560 if (n < 0)
2561 return -ENOMEM;
2562 if ((uint64_t) n != p->size)
2563 return -EIO;
2564
2565 e = memchr(buf, 0, p->size);
2566 if (e) {
2567 /* If we found a NUL byte then the rest of the data must be NUL too */
2568 if (!memeqzero(e, p->size - (e - buf)))
2569 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature data contains embedded NUL byte.");
2570 } else
2571 buf[p->size] = 0;
2572
2573 r = json_parse(buf, 0, &v, NULL, NULL);
2574 if (r < 0)
2575 return log_debug_errno(r, "Failed to parse signature JSON data: %m");
2576
2577 rh = json_variant_by_key(v, "rootHash");
2578 if (!rh)
2579 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature JSON object lacks 'rootHash' field.");
2580 if (!json_variant_is_string(rh))
2581 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "'rootHash' field of signature JSON object is not a string.");
2582
2583 r = unhexmem(json_variant_string(rh), SIZE_MAX, &root_hash, &root_hash_size);
2584 if (r < 0)
2585 return log_debug_errno(r, "Failed to parse root hash field: %m");
2586
2587 /* Check if specified root hash matches if it is specified */
2588 if (verity->root_hash &&
2589 memcmp_nn(verity->root_hash, verity->root_hash_size, root_hash, root_hash_size) != 0) {
2590 _cleanup_free_ char *a = NULL, *b = NULL;
2591
2592 a = hexmem(root_hash, root_hash_size);
2593 b = hexmem(verity->root_hash, verity->root_hash_size);
2594
2595 return log_debug_errno(r, "Root hash in signature JSON data (%s) doesn't match configured hash (%s).", strna(a), strna(b));
2596 }
2597
2598 sig = json_variant_by_key(v, "signature");
2599 if (!sig)
2600 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature JSON object lacks 'signature' field.");
2601 if (!json_variant_is_string(sig))
2602 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "'signature' field of signature JSON object is not a string.");
2603
2604 r = unbase64mem(json_variant_string(sig), SIZE_MAX, &root_hash_sig, &root_hash_sig_size);
2605 if (r < 0)
2606 return log_debug_errno(r, "Failed to parse signature field: %m");
2607
2608 free_and_replace(verity->root_hash, root_hash);
2609 verity->root_hash_size = root_hash_size;
2610
2611 free_and_replace(verity->root_hash_sig, root_hash_sig);
2612 verity->root_hash_sig_size = root_hash_sig_size;
2613
2614 return 1;
2615 }
2616
2617 int dissected_image_acquire_metadata(DissectedImage *m, DissectImageFlags extra_flags) {
2618
2619 enum {
2620 META_HOSTNAME,
2621 META_MACHINE_ID,
2622 META_MACHINE_INFO,
2623 META_OS_RELEASE,
2624 META_EXTENSION_RELEASE,
2625 META_HAS_INIT_SYSTEM,
2626 _META_MAX,
2627 };
2628
2629 static const char *const paths[_META_MAX] = {
2630 [META_HOSTNAME] = "/etc/hostname\0",
2631 [META_MACHINE_ID] = "/etc/machine-id\0",
2632 [META_MACHINE_INFO] = "/etc/machine-info\0",
2633 [META_OS_RELEASE] = ("/etc/os-release\0"
2634 "/usr/lib/os-release\0"),
2635 [META_EXTENSION_RELEASE] = "extension-release\0", /* Used only for logging. */
2636 [META_HAS_INIT_SYSTEM] = "has-init-system\0", /* ditto */
2637 };
2638
2639 _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL, **extension_release = NULL;
2640 _cleanup_close_pair_ int error_pipe[2] = { -1, -1 };
2641 _cleanup_(rmdir_and_freep) char *t = NULL;
2642 _cleanup_(sigkill_waitp) pid_t child = 0;
2643 sd_id128_t machine_id = SD_ID128_NULL;
2644 _cleanup_free_ char *hostname = NULL;
2645 unsigned n_meta_initialized = 0;
2646 int fds[2 * _META_MAX], r, v;
2647 int has_init_system = -1;
2648 ssize_t n;
2649
2650 BLOCK_SIGNALS(SIGCHLD);
2651
2652 assert(m);
2653
2654 for (; n_meta_initialized < _META_MAX; n_meta_initialized ++) {
2655 if (!paths[n_meta_initialized]) {
2656 fds[2*n_meta_initialized] = fds[2*n_meta_initialized+1] = -1;
2657 continue;
2658 }
2659
2660 if (pipe2(fds + 2*n_meta_initialized, O_CLOEXEC) < 0) {
2661 r = -errno;
2662 goto finish;
2663 }
2664 }
2665
2666 r = mkdtemp_malloc("/tmp/dissect-XXXXXX", &t);
2667 if (r < 0)
2668 goto finish;
2669
2670 if (pipe2(error_pipe, O_CLOEXEC) < 0) {
2671 r = -errno;
2672 goto finish;
2673 }
2674
2675 r = safe_fork("(sd-dissect)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, &child);
2676 if (r < 0)
2677 goto finish;
2678 if (r == 0) {
2679 /* Child in a new mount namespace */
2680 error_pipe[0] = safe_close(error_pipe[0]);
2681
2682 r = dissected_image_mount(
2683 m,
2684 t,
2685 UID_INVALID,
2686 UID_INVALID,
2687 extra_flags |
2688 DISSECT_IMAGE_READ_ONLY |
2689 DISSECT_IMAGE_MOUNT_ROOT_ONLY |
2690 DISSECT_IMAGE_USR_NO_ROOT);
2691 if (r < 0) {
2692 log_debug_errno(r, "Failed to mount dissected image: %m");
2693 goto inner_fail;
2694 }
2695
2696 for (unsigned k = 0; k < _META_MAX; k++) {
2697 _cleanup_close_ int fd = -ENOENT;
2698 const char *p;
2699
2700 if (!paths[k])
2701 continue;
2702
2703 fds[2*k] = safe_close(fds[2*k]);
2704
2705 switch (k) {
2706
2707 case META_EXTENSION_RELEASE:
2708 /* As per the os-release spec, if the image is an extension it will have a file
2709 * named after the image name in extension-release.d/ - we use the image name
2710 * and try to resolve it with the extension-release helpers, as sometimes
2711 * the image names are mangled on deployment and do not match anymore.
2712 * Unlike other paths this is not fixed, and the image name
2713 * can be mangled on deployment, so by calling into the helper
2714 * we allow a fallback that matches on the first extension-release
2715 * file found in the directory, if one named after the image cannot
2716 * be found first. */
2717 r = open_extension_release(t, m->image_name, NULL, &fd);
2718 if (r < 0)
2719 fd = r; /* Propagate the error. */
2720 break;
2721
2722 case META_HAS_INIT_SYSTEM: {
2723 bool found = false;
2724
2725 FOREACH_STRING(init,
2726 "/usr/lib/systemd/systemd", /* systemd on /usr merged system */
2727 "/lib/systemd/systemd", /* systemd on /usr non-merged systems */
2728 "/sbin/init") { /* traditional path the Linux kernel invokes */
2729
2730 r = chase_symlinks(init, t, CHASE_PREFIX_ROOT, NULL, NULL);
2731 if (r < 0) {
2732 if (r != -ENOENT)
2733 log_debug_errno(r, "Failed to resolve %s, ignoring: %m", init);
2734 } else {
2735 found = true;
2736 break;
2737 }
2738 }
2739
2740 r = loop_write(fds[2*k+1], &found, sizeof(found), false);
2741 if (r < 0)
2742 goto inner_fail;
2743
2744 continue;
2745 }
2746
2747 default:
2748 NULSTR_FOREACH(p, paths[k]) {
2749 fd = chase_symlinks_and_open(p, t, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_NOCTTY, NULL);
2750 if (fd >= 0)
2751 break;
2752 }
2753 }
2754
2755 if (fd < 0) {
2756 log_debug_errno(fd, "Failed to read %s file of image, ignoring: %m", paths[k]);
2757 fds[2*k+1] = safe_close(fds[2*k+1]);
2758 continue;
2759 }
2760
2761 r = copy_bytes(fd, fds[2*k+1], UINT64_MAX, 0);
2762 if (r < 0)
2763 goto inner_fail;
2764
2765 fds[2*k+1] = safe_close(fds[2*k+1]);
2766 }
2767
2768 _exit(EXIT_SUCCESS);
2769
2770 inner_fail:
2771 /* Let parent know the error */
2772 (void) write(error_pipe[1], &r, sizeof(r));
2773 _exit(EXIT_FAILURE);
2774 }
2775
2776 error_pipe[1] = safe_close(error_pipe[1]);
2777
2778 for (unsigned k = 0; k < _META_MAX; k++) {
2779 _cleanup_fclose_ FILE *f = NULL;
2780
2781 if (!paths[k])
2782 continue;
2783
2784 fds[2*k+1] = safe_close(fds[2*k+1]);
2785
2786 f = take_fdopen(&fds[2*k], "r");
2787 if (!f) {
2788 r = -errno;
2789 goto finish;
2790 }
2791
2792 switch (k) {
2793
2794 case META_HOSTNAME:
2795 r = read_etc_hostname_stream(f, &hostname);
2796 if (r < 0)
2797 log_debug_errno(r, "Failed to read /etc/hostname of image: %m");
2798
2799 break;
2800
2801 case META_MACHINE_ID: {
2802 _cleanup_free_ char *line = NULL;
2803
2804 r = read_line(f, LONG_LINE_MAX, &line);
2805 if (r < 0)
2806 log_debug_errno(r, "Failed to read /etc/machine-id of image: %m");
2807 else if (r == 33) {
2808 r = sd_id128_from_string(line, &machine_id);
2809 if (r < 0)
2810 log_debug_errno(r, "Image contains invalid /etc/machine-id: %s", line);
2811 } else if (r == 0)
2812 log_debug("/etc/machine-id file of image is empty.");
2813 else if (streq(line, "uninitialized"))
2814 log_debug("/etc/machine-id file of image is uninitialized (likely aborted first boot).");
2815 else
2816 log_debug("/etc/machine-id file of image has unexpected length %i.", r);
2817
2818 break;
2819 }
2820
2821 case META_MACHINE_INFO:
2822 r = load_env_file_pairs(f, "machine-info", &machine_info);
2823 if (r < 0)
2824 log_debug_errno(r, "Failed to read /etc/machine-info of image: %m");
2825
2826 break;
2827
2828 case META_OS_RELEASE:
2829 r = load_env_file_pairs(f, "os-release", &os_release);
2830 if (r < 0)
2831 log_debug_errno(r, "Failed to read OS release file of image: %m");
2832
2833 break;
2834
2835 case META_EXTENSION_RELEASE:
2836 r = load_env_file_pairs(f, "extension-release", &extension_release);
2837 if (r < 0)
2838 log_debug_errno(r, "Failed to read extension release file of image: %m");
2839
2840 break;
2841
2842 case META_HAS_INIT_SYSTEM: {
2843 bool b = false;
2844 size_t nr;
2845
2846 errno = 0;
2847 nr = fread(&b, 1, sizeof(b), f);
2848 if (nr != sizeof(b))
2849 log_debug_errno(errno_or_else(EIO), "Failed to read has-init-system boolean: %m");
2850 else
2851 has_init_system = b;
2852
2853 break;
2854 }}
2855 }
2856
2857 r = wait_for_terminate_and_check("(sd-dissect)", child, 0);
2858 child = 0;
2859 if (r < 0)
2860 return r;
2861
2862 n = read(error_pipe[0], &v, sizeof(v));
2863 if (n < 0)
2864 return -errno;
2865 if (n == sizeof(v))
2866 return v; /* propagate error sent to us from child */
2867 if (n != 0)
2868 return -EIO;
2869
2870 if (r != EXIT_SUCCESS)
2871 return -EPROTO;
2872
2873 free_and_replace(m->hostname, hostname);
2874 m->machine_id = machine_id;
2875 strv_free_and_replace(m->machine_info, machine_info);
2876 strv_free_and_replace(m->os_release, os_release);
2877 strv_free_and_replace(m->extension_release, extension_release);
2878 m->has_init_system = has_init_system;
2879
2880 finish:
2881 for (unsigned k = 0; k < n_meta_initialized; k++)
2882 safe_close_pair(fds + 2*k);
2883
2884 return r;
2885 }
2886
2887 int dissect_loop_device(
2888 LoopDevice *loop,
2889 const VeritySettings *verity,
2890 const MountOptions *mount_options,
2891 DissectImageFlags flags,
2892 DissectedImage **ret) {
2893
2894 #if HAVE_BLKID
2895 _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
2896 int r;
2897
2898 assert(loop);
2899 assert(ret);
2900
2901 r = dissected_image_new(loop->backing_file ?: loop->node, &m);
2902 if (r < 0)
2903 return r;
2904
2905 m->loop = loop_device_ref(loop);
2906
2907 r = dissect_image(m, loop->fd, loop->node, verity, mount_options, flags | DISSECT_IMAGE_BLOCK_DEVICE);
2908 if (r < 0)
2909 return r;
2910
2911 r = dissected_image_probe_filesystem(m);
2912 if (r < 0)
2913 return r;
2914
2915 *ret = TAKE_PTR(m);
2916 return 0;
2917 #else
2918 return -EOPNOTSUPP;
2919 #endif
2920 }
2921
2922 int dissect_loop_device_and_warn(
2923 LoopDevice *loop,
2924 const VeritySettings *verity,
2925 const MountOptions *mount_options,
2926 DissectImageFlags flags,
2927 DissectedImage **ret) {
2928
2929 const char *name;
2930 int r;
2931
2932 assert(loop);
2933 assert(loop->fd >= 0);
2934
2935 name = ASSERT_PTR(loop->backing_file ?: loop->node);
2936
2937 r = dissect_loop_device(loop, verity, mount_options, flags, ret);
2938 switch (r) {
2939
2940 case -EOPNOTSUPP:
2941 return log_error_errno(r, "Dissecting images is not supported, compiled without blkid support.");
2942
2943 case -ENOPKG:
2944 return log_error_errno(r, "%s: Couldn't identify a suitable partition table or file system.", name);
2945
2946 case -ENOMEDIUM:
2947 return log_error_errno(r, "%s: The image does not pass validation.", name);
2948
2949 case -EADDRNOTAVAIL:
2950 return log_error_errno(r, "%s: No root partition for specified root hash found.", name);
2951
2952 case -ENOTUNIQ:
2953 return log_error_errno(r, "%s: Multiple suitable root partitions found in image.", name);
2954
2955 case -ENXIO:
2956 return log_error_errno(r, "%s: No suitable root partition found in image.", name);
2957
2958 case -EPROTONOSUPPORT:
2959 return log_error_errno(r, "Device '%s' is loopback block device with partition scanning turned off, please turn it on.", name);
2960
2961 case -ENOTBLK:
2962 return log_error_errno(r, "%s: Image is not a block device.", name);
2963
2964 case -EBADR:
2965 return log_error_errno(r,
2966 "Combining partitioned images (such as '%s') with external Verity data (such as '%s') not supported. "
2967 "(Consider setting $SYSTEMD_DISSECT_VERITY_SIDECAR=0 to disable automatic discovery of external Verity data.)",
2968 name, strna(verity ? verity->data_path : NULL));
2969
2970 default:
2971 if (r < 0)
2972 return log_error_errno(r, "Failed to dissect image '%s': %m", name);
2973
2974 return r;
2975 }
2976 }
2977
2978 bool dissected_image_verity_candidate(const DissectedImage *image, PartitionDesignator partition_designator) {
2979 assert(image);
2980
2981 /* Checks if this partition could theoretically do Verity. For non-partitioned images this only works
2982 * if there's an external verity file supplied, for which we can consult .has_verity. For partitioned
2983 * images we only check the partition type.
2984 *
2985 * This call is used to decide whether to suppress or show a verity column in tabular output of the
2986 * image. */
2987
2988 if (image->single_file_system)
2989 return partition_designator == PARTITION_ROOT && image->has_verity;
2990
2991 return PARTITION_VERITY_OF(partition_designator) >= 0;
2992 }
2993
2994 bool dissected_image_verity_ready(const DissectedImage *image, PartitionDesignator partition_designator) {
2995 PartitionDesignator k;
2996
2997 assert(image);
2998
2999 /* Checks if this partition has verity data available that we can activate. For non-partitioned this
3000 * works for the root partition, for others only if the associated verity partition was found. */
3001
3002 if (!image->verity_ready)
3003 return false;
3004
3005 if (image->single_file_system)
3006 return partition_designator == PARTITION_ROOT;
3007
3008 k = PARTITION_VERITY_OF(partition_designator);
3009 return k >= 0 && image->partitions[k].found;
3010 }
3011
3012 bool dissected_image_verity_sig_ready(const DissectedImage *image, PartitionDesignator partition_designator) {
3013 PartitionDesignator k;
3014
3015 assert(image);
3016
3017 /* Checks if this partition has verity signature data available that we can use. */
3018
3019 if (!image->verity_sig_ready)
3020 return false;
3021
3022 if (image->single_file_system)
3023 return partition_designator == PARTITION_ROOT;
3024
3025 k = PARTITION_VERITY_SIG_OF(partition_designator);
3026 return k >= 0 && image->partitions[k].found;
3027 }
3028
3029 MountOptions* mount_options_free_all(MountOptions *options) {
3030 MountOptions *m;
3031
3032 while ((m = options)) {
3033 LIST_REMOVE(mount_options, options, m);
3034 free(m->options);
3035 free(m);
3036 }
3037
3038 return NULL;
3039 }
3040
3041 const char* mount_options_from_designator(const MountOptions *options, PartitionDesignator designator) {
3042 LIST_FOREACH(mount_options, m, options)
3043 if (designator == m->partition_designator && !isempty(m->options))
3044 return m->options;
3045
3046 return NULL;
3047 }
3048
3049 int mount_image_privately_interactively(
3050 const char *image,
3051 DissectImageFlags flags,
3052 char **ret_directory,
3053 LoopDevice **ret_loop_device) {
3054
3055 _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT;
3056 _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
3057 _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
3058 _cleanup_(rmdir_and_freep) char *created_dir = NULL;
3059 _cleanup_free_ char *temp = NULL;
3060 int r;
3061
3062 /* Mounts an OS image at a temporary place, inside a newly created mount namespace of our own. This
3063 * is used by tools such as systemd-tmpfiles or systemd-firstboot to operate on some disk image
3064 * easily. */
3065
3066 assert(image);
3067 assert(ret_directory);
3068 assert(ret_loop_device);
3069
3070 r = verity_settings_load(&verity, image, NULL, NULL);
3071 if (r < 0)
3072 return log_error_errno(r, "Failed to load root hash data: %m");
3073
3074 r = tempfn_random_child(NULL, program_invocation_short_name, &temp);
3075 if (r < 0)
3076 return log_error_errno(r, "Failed to generate temporary mount directory: %m");
3077
3078 r = loop_device_make_by_path(
3079 image,
3080 FLAGS_SET(flags, DISSECT_IMAGE_DEVICE_READ_ONLY) ? O_RDONLY : O_RDWR,
3081 FLAGS_SET(flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN,
3082 LOCK_SH,
3083 &d);
3084 if (r < 0)
3085 return log_error_errno(r, "Failed to set up loopback device for %s: %m", image);
3086
3087 r = dissect_loop_device_and_warn(d, &verity, NULL, flags, &dissected_image);
3088 if (r < 0)
3089 return r;
3090
3091 r = dissected_image_load_verity_sig_partition(dissected_image, d->fd, &verity);
3092 if (r < 0)
3093 return r;
3094
3095 r = dissected_image_decrypt_interactively(dissected_image, NULL, &verity, flags);
3096 if (r < 0)
3097 return r;
3098
3099 r = detach_mount_namespace();
3100 if (r < 0)
3101 return log_error_errno(r, "Failed to detach mount namespace: %m");
3102
3103 r = mkdir_p(temp, 0700);
3104 if (r < 0)
3105 return log_error_errno(r, "Failed to create mount point: %m");
3106
3107 created_dir = TAKE_PTR(temp);
3108
3109 r = dissected_image_mount_and_warn(dissected_image, created_dir, UID_INVALID, UID_INVALID, flags);
3110 if (r < 0)
3111 return r;
3112
3113 r = loop_device_flock(d, LOCK_UN);
3114 if (r < 0)
3115 return r;
3116
3117 r = dissected_image_relinquish(dissected_image);
3118 if (r < 0)
3119 return log_error_errno(r, "Failed to relinquish DM and loopback block devices: %m");
3120
3121 *ret_directory = TAKE_PTR(created_dir);
3122 *ret_loop_device = TAKE_PTR(d);
3123
3124 return 0;
3125 }
3126
3127 static const char *const partition_designator_table[] = {
3128 [PARTITION_ROOT] = "root",
3129 [PARTITION_ROOT_SECONDARY] = "root-secondary",
3130 [PARTITION_ROOT_OTHER] = "root-other",
3131 [PARTITION_USR] = "usr",
3132 [PARTITION_USR_SECONDARY] = "usr-secondary",
3133 [PARTITION_USR_OTHER] = "usr-other",
3134 [PARTITION_HOME] = "home",
3135 [PARTITION_SRV] = "srv",
3136 [PARTITION_ESP] = "esp",
3137 [PARTITION_XBOOTLDR] = "xbootldr",
3138 [PARTITION_SWAP] = "swap",
3139 [PARTITION_ROOT_VERITY] = "root-verity",
3140 [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity",
3141 [PARTITION_ROOT_OTHER_VERITY] = "root-other-verity",
3142 [PARTITION_USR_VERITY] = "usr-verity",
3143 [PARTITION_USR_SECONDARY_VERITY] = "usr-secondary-verity",
3144 [PARTITION_USR_OTHER_VERITY] = "usr-other-verity",
3145 [PARTITION_ROOT_VERITY_SIG] = "root-verity-sig",
3146 [PARTITION_ROOT_SECONDARY_VERITY_SIG] = "root-secondary-verity-sig",
3147 [PARTITION_ROOT_OTHER_VERITY_SIG] = "root-other-verity-sig",
3148 [PARTITION_USR_VERITY_SIG] = "usr-verity-sig",
3149 [PARTITION_USR_SECONDARY_VERITY_SIG] = "usr-secondary-verity-sig",
3150 [PARTITION_USR_OTHER_VERITY_SIG] = "usr-other-verity-sig",
3151 [PARTITION_TMP] = "tmp",
3152 [PARTITION_VAR] = "var",
3153 };
3154
3155 int verity_dissect_and_mount(
3156 int src_fd,
3157 const char *src,
3158 const char *dest,
3159 const MountOptions *options,
3160 const char *required_host_os_release_id,
3161 const char *required_host_os_release_version_id,
3162 const char *required_host_os_release_sysext_level,
3163 const char *required_sysext_scope) {
3164
3165 _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL;
3166 _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
3167 _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT;
3168 DissectImageFlags dissect_image_flags;
3169 int r;
3170
3171 assert(src);
3172 assert(dest);
3173
3174 /* We might get an FD for the image, but we use the original path to look for the dm-verity files */
3175 r = verity_settings_load(&verity, src, NULL, NULL);
3176 if (r < 0)
3177 return log_debug_errno(r, "Failed to load root hash: %m");
3178
3179 dissect_image_flags = verity.data_path ? DISSECT_IMAGE_NO_PARTITION_TABLE : 0;
3180
3181 /* Note that we don't use loop_device_make here, as the FD is most likely O_PATH which would not be
3182 * accepted by LOOP_CONFIGURE, so just let loop_device_make_by_path reopen it as a regular FD. */
3183 r = loop_device_make_by_path(
3184 src_fd >= 0 ? FORMAT_PROC_FD_PATH(src_fd) : src,
3185 -1,
3186 verity.data_path ? 0 : LO_FLAGS_PARTSCAN,
3187 LOCK_SH,
3188 &loop_device);
3189 if (r < 0)
3190 return log_debug_errno(r, "Failed to create loop device for image: %m");
3191
3192 r = dissect_loop_device(
3193 loop_device,
3194 &verity,
3195 options,
3196 dissect_image_flags,
3197 &dissected_image);
3198 /* No partition table? Might be a single-filesystem image, try again */
3199 if (!verity.data_path && r == -ENOPKG)
3200 r = dissect_loop_device(
3201 loop_device,
3202 &verity,
3203 options,
3204 dissect_image_flags | DISSECT_IMAGE_NO_PARTITION_TABLE,
3205 &dissected_image);
3206 if (r < 0)
3207 return log_debug_errno(r, "Failed to dissect image: %m");
3208
3209 r = dissected_image_load_verity_sig_partition(dissected_image, loop_device->fd, &verity);
3210 if (r < 0)
3211 return r;
3212
3213 r = dissected_image_decrypt(
3214 dissected_image,
3215 NULL,
3216 &verity,
3217 dissect_image_flags);
3218 if (r < 0)
3219 return log_debug_errno(r, "Failed to decrypt dissected image: %m");
3220
3221 r = mkdir_p_label(dest, 0755);
3222 if (r < 0)
3223 return log_debug_errno(r, "Failed to create destination directory %s: %m", dest);
3224 r = umount_recursive(dest, 0);
3225 if (r < 0)
3226 return log_debug_errno(r, "Failed to umount under destination directory %s: %m", dest);
3227
3228 r = dissected_image_mount(dissected_image, dest, UID_INVALID, UID_INVALID, dissect_image_flags);
3229 if (r < 0)
3230 return log_debug_errno(r, "Failed to mount image: %m");
3231
3232 r = loop_device_flock(loop_device, LOCK_UN);
3233 if (r < 0)
3234 return log_debug_errno(r, "Failed to unlock loopback device: %m");
3235
3236 /* If we got os-release values from the caller, then we need to match them with the image's
3237 * extension-release.d/ content. Return -EINVAL if there's any mismatch.
3238 * First, check the distro ID. If that matches, then check the new SYSEXT_LEVEL value if
3239 * available, or else fallback to VERSION_ID. If neither is present (eg: rolling release),
3240 * then a simple match on the ID will be performed. */
3241 if (required_host_os_release_id) {
3242 _cleanup_strv_free_ char **extension_release = NULL;
3243
3244 assert(!isempty(required_host_os_release_id));
3245
3246 r = load_extension_release_pairs(dest, dissected_image->image_name, &extension_release);
3247 if (r < 0)
3248 return log_debug_errno(r, "Failed to parse image %s extension-release metadata: %m", dissected_image->image_name);
3249
3250 r = extension_release_validate(
3251 dissected_image->image_name,
3252 required_host_os_release_id,
3253 required_host_os_release_version_id,
3254 required_host_os_release_sysext_level,
3255 required_sysext_scope,
3256 extension_release);
3257 if (r == 0)
3258 return log_debug_errno(SYNTHETIC_ERRNO(ESTALE), "Image %s extension-release metadata does not match the root's", dissected_image->image_name);
3259 if (r < 0)
3260 return log_debug_errno(r, "Failed to compare image %s extension-release metadata with the root's os-release: %m", dissected_image->image_name);
3261 }
3262
3263 r = dissected_image_relinquish(dissected_image);
3264 if (r < 0)
3265 return log_debug_errno(r, "Failed to relinquish dissected image: %m");
3266
3267 return 0;
3268 }
3269
3270 DEFINE_STRING_TABLE_LOOKUP(partition_designator, PartitionDesignator);
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