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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
commit55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch)
tree33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/shared/dissect-image.c
parentInitial commit. (diff)
downloadsystemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz
systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/shared/dissect-image.c')
-rw-r--r--src/shared/dissect-image.c4069
1 files changed, 4069 insertions, 0 deletions
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
new file mode 100644
index 0000000..84cfbcd
--- /dev/null
+++ b/src/shared/dissect-image.c
@@ -0,0 +1,4069 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#if HAVE_VALGRIND_MEMCHECK_H
+#include <valgrind/memcheck.h>
+#endif
+
+#include <linux/dm-ioctl.h>
+#include <linux/loop.h>
+#include <sys/file.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <sysexits.h>
+
+#if HAVE_OPENSSL
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/x509.h>
+#endif
+
+#include "sd-device.h"
+#include "sd-id128.h"
+
+#include "architecture.h"
+#include "ask-password-api.h"
+#include "blkid-util.h"
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "chase.h"
+#include "conf-files.h"
+#include "constants.h"
+#include "copy.h"
+#include "cryptsetup-util.h"
+#include "device-nodes.h"
+#include "device-util.h"
+#include "devnum-util.h"
+#include "discover-image.h"
+#include "dissect-image.h"
+#include "dm-util.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "extension-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "fsck-util.h"
+#include "gpt.h"
+#include "hexdecoct.h"
+#include "hostname-setup.h"
+#include "id128-util.h"
+#include "import-util.h"
+#include "io-util.h"
+#include "missing_mount.h"
+#include "missing_syscall.h"
+#include "mkdir-label.h"
+#include "mount-util.h"
+#include "mountpoint-util.h"
+#include "namespace-util.h"
+#include "nulstr-util.h"
+#include "openssl-util.h"
+#include "os-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "raw-clone.h"
+#include "resize-fs.h"
+#include "signal-util.h"
+#include "sparse-endian.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "tmpfile-util.h"
+#include "udev-util.h"
+#include "user-util.h"
+#include "xattr-util.h"
+
+/* how many times to wait for the device nodes to appear */
+#define N_DEVICE_NODE_LIST_ATTEMPTS 10
+
+int dissect_fstype_ok(const char *fstype) {
+ const char *e;
+ bool b;
+
+ /* When we automatically mount file systems, be a bit conservative by default what we are willing to
+ * mount, just as an extra safety net to not mount with badly maintained legacy file system
+ * drivers. */
+
+ e = secure_getenv("SYSTEMD_DISSECT_FILE_SYSTEMS");
+ if (e) {
+ _cleanup_strv_free_ char **l = NULL;
+
+ l = strv_split(e, ":");
+ if (!l)
+ return -ENOMEM;
+
+ b = strv_contains(l, fstype);
+ } else
+ b = STR_IN_SET(fstype,
+ "btrfs",
+ "erofs",
+ "ext4",
+ "f2fs",
+ "squashfs",
+ "vfat",
+ "xfs");
+ if (b)
+ return true;
+
+ log_debug("File system type '%s' is not allowed to be mounted as result of automatic dissection.", fstype);
+ return false;
+}
+
+int probe_sector_size(int fd, uint32_t *ret) {
+
+ /* Disk images might be for 512B or for 4096 sector sizes, let's try to auto-detect that by searching
+ * for the GPT headers at the relevant byte offsets */
+
+ assert_cc(sizeof(GptHeader) == 92);
+
+ /* We expect a sector size in the range 512…4096. The GPT header is located in the second
+ * sector. Hence it could be at byte 512 at the earliest, and at byte 4096 at the latest. And we must
+ * read with granularity of the largest sector size we care about. Which means 8K. */
+ uint8_t sectors[2 * 4096];
+ uint32_t found = 0;
+ ssize_t n;
+
+ assert(fd >= 0);
+ assert(ret);
+
+ n = pread(fd, sectors, sizeof(sectors), 0);
+ if (n < 0)
+ return -errno;
+ if (n != sizeof(sectors)) /* too short? */
+ goto not_found;
+
+ /* Let's see if we find the GPT partition header with various expected sector sizes */
+ for (uint32_t sz = 512; sz <= 4096; sz <<= 1) {
+ const GptHeader *p;
+
+ assert(sizeof(sectors) >= sz * 2);
+ p = (const GptHeader*) (sectors + sz);
+
+ if (!gpt_header_has_signature(p))
+ continue;
+
+ if (found != 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOTUNIQ),
+ "Detected valid partition table at offsets matching multiple sector sizes, refusing.");
+
+ found = sz;
+ }
+
+ if (found != 0) {
+ log_debug("Determined sector size %" PRIu32 " based on discovered partition table.", found);
+ *ret = found;
+ return 1; /* indicate we *did* find it */
+ }
+
+not_found:
+ log_debug("Couldn't find any partition table to derive sector size of.");
+ *ret = 512; /* pick the traditional default */
+ return 0; /* indicate we didn't find it */
+}
+
+int probe_sector_size_prefer_ioctl(int fd, uint32_t *ret) {
+ struct stat st;
+
+ assert(fd >= 0);
+ assert(ret);
+
+ /* Just like probe_sector_size(), but if we are looking at a block device, will use the already
+ * configured sector size rather than probing by contents */
+
+ if (fstat(fd, &st) < 0)
+ return -errno;
+
+ if (S_ISBLK(st.st_mode))
+ return blockdev_get_sector_size(fd, ret);
+
+ return probe_sector_size(fd, ret);
+}
+
+int probe_filesystem_full(
+ int fd,
+ const char *path,
+ uint64_t offset,
+ uint64_t size,
+ char **ret_fstype) {
+
+ /* Try to find device content type and return it in *ret_fstype. If nothing is found,
+ * 0/NULL will be returned. -EUCLEAN will be returned for ambiguous results, and a
+ * different error otherwise. */
+
+#if HAVE_BLKID
+ _cleanup_(blkid_free_probep) blkid_probe b = NULL;
+ _cleanup_free_ char *path_by_fd = NULL;
+ _cleanup_close_ int fd_close = -EBADF;
+ const char *fstype;
+ int r;
+
+ assert(fd >= 0 || path);
+ assert(ret_fstype);
+
+ if (fd < 0) {
+ fd_close = open(path, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (fd_close < 0)
+ return -errno;
+
+ fd = fd_close;
+ }
+
+ if (!path) {
+ r = fd_get_path(fd, &path_by_fd);
+ if (r < 0)
+ return r;
+
+ path = path_by_fd;
+ }
+
+ if (size == 0) /* empty size? nothing found! */
+ goto not_found;
+
+ b = blkid_new_probe();
+ if (!b)
+ return -ENOMEM;
+
+ /* The Linux kernel maintains separate block device caches for main ("whole") and partition block
+ * devices, which means making a change to one might not be reflected immediately when reading via
+ * the other. That's massively confusing when mixing accesses to such devices. Let's address this in
+ * a limited way: when probing a file system that is not at the beginning of the block device we
+ * apparently probe a partition via the main block device, and in that case let's first flush the
+ * main block device cache, so that we get the data that the per-partition block device last
+ * sync'ed on.
+ *
+ * This only works under the assumption that any tools that write to the partition block devices
+ * issue an syncfs()/fsync() on the device after making changes. Typically file system formatting
+ * tools that write a superblock onto a partition block device do that, however. */
+ if (offset != 0)
+ if (ioctl(fd, BLKFLSBUF, 0) < 0)
+ log_debug_errno(errno, "Failed to flush block device cache, ignoring: %m");
+
+ errno = 0;
+ r = blkid_probe_set_device(
+ b,
+ fd,
+ offset,
+ size == UINT64_MAX ? 0 : size); /* when blkid sees size=0 it understands "everything". We prefer using UINT64_MAX for that */
+ if (r != 0)
+ return errno_or_else(ENOMEM);
+
+ blkid_probe_enable_superblocks(b, 1);
+ blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
+
+ errno = 0;
+ r = blkid_do_safeprobe(b);
+ if (r == _BLKID_SAFEPROBE_NOT_FOUND)
+ goto not_found;
+ if (r == _BLKID_SAFEPROBE_AMBIGUOUS)
+ return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN),
+ "Results ambiguous for partition %s", path);
+ if (r == _BLKID_SAFEPROBE_ERROR)
+ return log_debug_errno(errno_or_else(EIO), "Failed to probe partition %s: %m", path);
+
+ assert(r == _BLKID_SAFEPROBE_FOUND);
+
+ (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
+
+ if (fstype) {
+ char *t;
+
+ log_debug("Probed fstype '%s' on partition %s.", fstype, path);
+
+ t = strdup(fstype);
+ if (!t)
+ return -ENOMEM;
+
+ *ret_fstype = t;
+ return 1;
+ }
+
+not_found:
+ log_debug("No type detected on partition %s", path);
+ *ret_fstype = NULL;
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+#if HAVE_BLKID
+static int image_policy_may_use(
+ const ImagePolicy *policy,
+ PartitionDesignator designator) {
+
+ PartitionPolicyFlags f;
+
+ /* For each partition we find in the partition table do a first check if it may exist at all given
+ * the policy, or if it shall be ignored. */
+
+ f = image_policy_get_exhaustively(policy, designator);
+ if (f < 0)
+ return f;
+
+ if ((f & _PARTITION_POLICY_USE_MASK) == PARTITION_POLICY_ABSENT)
+ /* only flag set in policy is "absent"? then this partition may not exist at all */
+ return log_debug_errno(
+ SYNTHETIC_ERRNO(ERFKILL),
+ "Partition of designator '%s' exists, but not allowed by policy, refusing.",
+ partition_designator_to_string(designator));
+ if ((f & _PARTITION_POLICY_USE_MASK & ~PARTITION_POLICY_ABSENT) == PARTITION_POLICY_UNUSED) {
+ /* only "unused" or "unused" + "absent" are set? then don't use it */
+ log_debug("Partition of designator '%s' exists, and policy dictates to ignore it, doing so.",
+ partition_designator_to_string(designator));
+ return false; /* ignore! */
+ }
+
+ return true; /* use! */
+}
+
+static int image_policy_check_protection(
+ const ImagePolicy *policy,
+ PartitionDesignator designator,
+ PartitionPolicyFlags found_flags) {
+
+ PartitionPolicyFlags policy_flags;
+
+ /* Checks if the flags in the policy for the designated partition overlap the flags of what we found */
+
+ if (found_flags < 0)
+ return found_flags;
+
+ policy_flags = image_policy_get_exhaustively(policy, designator);
+ if (policy_flags < 0)
+ return policy_flags;
+
+ if ((found_flags & policy_flags) == 0) {
+ _cleanup_free_ char *found_flags_string = NULL, *policy_flags_string = NULL;
+
+ (void) partition_policy_flags_to_string(found_flags, /* simplify= */ true, &found_flags_string);
+ (void) partition_policy_flags_to_string(policy_flags, /* simplify= */ true, &policy_flags_string);
+
+ return log_debug_errno(SYNTHETIC_ERRNO(ERFKILL), "Partition %s discovered with policy '%s' but '%s' was required, refusing.",
+ partition_designator_to_string(designator),
+ strnull(found_flags_string), strnull(policy_flags_string));
+ }
+
+ return 0;
+}
+
+static int image_policy_check_partition_flags(
+ const ImagePolicy *policy,
+ PartitionDesignator designator,
+ uint64_t gpt_flags) {
+
+ PartitionPolicyFlags policy_flags;
+ bool b;
+
+ /* Checks if the partition flags in the policy match reality */
+
+ policy_flags = image_policy_get_exhaustively(policy, designator);
+ if (policy_flags < 0)
+ return policy_flags;
+
+ b = FLAGS_SET(gpt_flags, SD_GPT_FLAG_READ_ONLY);
+ if ((policy_flags & _PARTITION_POLICY_READ_ONLY_MASK) == (b ? PARTITION_POLICY_READ_ONLY_OFF : PARTITION_POLICY_READ_ONLY_ON))
+ return log_debug_errno(SYNTHETIC_ERRNO(ERFKILL), "Partition %s has 'read-only' flag incorrectly set (must be %s, is %s), refusing.",
+ partition_designator_to_string(designator),
+ one_zero(!b), one_zero(b));
+
+ b = FLAGS_SET(gpt_flags, SD_GPT_FLAG_GROWFS);
+ if ((policy_flags & _PARTITION_POLICY_GROWFS_MASK) == (b ? PARTITION_POLICY_GROWFS_OFF : PARTITION_POLICY_GROWFS_ON))
+ return log_debug_errno(SYNTHETIC_ERRNO(ERFKILL), "Partition %s has 'growfs' flag incorrectly set (must be %s, is %s), refusing.",
+ partition_designator_to_string(designator),
+ one_zero(!b), one_zero(b));
+
+ return 0;
+}
+
+static int dissected_image_probe_filesystems(
+ DissectedImage *m,
+ int fd,
+ const ImagePolicy *policy) {
+
+ int r;
+
+ assert(m);
+
+ /* Fill in file system types if we don't know them yet. */
+
+ for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
+ DissectedPartition *p = m->partitions + i;
+ PartitionPolicyFlags found_flags;
+
+ if (!p->found)
+ continue;
+
+ if (!p->fstype) {
+ /* If we have an fd referring to the partition block device, use that. Otherwise go
+ * via the whole block device or backing regular file, and read via offset. */
+ if (p->mount_node_fd >= 0)
+ r = probe_filesystem_full(p->mount_node_fd, p->node, 0, UINT64_MAX, &p->fstype);
+ else
+ r = probe_filesystem_full(fd, p->node, p->offset, p->size, &p->fstype);
+ if (r < 0)
+ return r;
+ }
+
+ if (streq_ptr(p->fstype, "crypto_LUKS")) {
+ m->encrypted = true;
+ found_flags = PARTITION_POLICY_ENCRYPTED; /* found this one, and its definitely encrypted */
+ } else
+ /* found it, but it's definitely not encrypted, hence mask the encrypted flag, but
+ * set all other ways that indicate "present". */
+ found_flags = PARTITION_POLICY_UNPROTECTED|PARTITION_POLICY_VERITY|PARTITION_POLICY_SIGNED;
+
+ if (p->fstype && fstype_is_ro(p->fstype))
+ p->rw = false;
+
+ if (!p->rw)
+ p->growfs = false;
+
+ /* We might have learnt more about the file system now (i.e. whether it is encrypted or not),
+ * hence we need to validate this against policy again, to see if the policy still matches
+ * with this new information. Note that image_policy_check_protection() will check for
+ * overlap between what's allowed in the policy and what we pass as 'found_policy' here. In
+ * the unencrypted case we thus might pass an overly unspecific mask here (i.e. unprotected
+ * OR verity OR signed), but that's fine since the earlier policy check already checked more
+ * specific which of those three cases where OK. Keep in mind that this function here only
+ * looks at specific partitions (and thus can only deduce encryption or not) but not the
+ * overall partition table (and thus cannot deduce verity or not). The earlier dissection
+ * checks already did the relevant checks that look at the whole partition table, and
+ * enforced policy there as needed. */
+ r = image_policy_check_protection(policy, i, found_flags);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+static void check_partition_flags(
+ const char *node,
+ unsigned long long pflags,
+ unsigned long long supported) {
+
+ assert(node);
+
+ /* Mask away all flags supported by this partition's type and the three flags the UEFI spec defines generically */
+ pflags &= ~(supported |
+ SD_GPT_FLAG_REQUIRED_PARTITION |
+ SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL |
+ SD_GPT_FLAG_LEGACY_BIOS_BOOTABLE);
+
+ if (pflags == 0)
+ return;
+
+ /* If there are other bits set, then log about it, to make things discoverable */
+ for (unsigned i = 0; i < sizeof(pflags) * 8; i++) {
+ unsigned long long bit = 1ULL << i;
+ if (!FLAGS_SET(pflags, bit))
+ continue;
+
+ log_debug("Unexpected partition flag %llu set on %s!", bit, node);
+ }
+}
+
+static int dissected_image_new(const char *path, DissectedImage **ret) {
+ _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+ _cleanup_free_ char *name = NULL;
+ int r;
+
+ assert(ret);
+
+ if (path) {
+ _cleanup_free_ char *filename = NULL;
+
+ r = path_extract_filename(path, &filename);
+ if (r < 0)
+ return r;
+
+ r = raw_strip_suffixes(filename, &name);
+ if (r < 0)
+ return r;
+
+ if (!image_name_is_valid(name)) {
+ log_debug("Image name %s is not valid, ignoring.", strna(name));
+ name = mfree(name);
+ }
+ }
+
+ m = new(DissectedImage, 1);
+ if (!m)
+ return -ENOMEM;
+
+ *m = (DissectedImage) {
+ .has_init_system = -1,
+ .image_name = TAKE_PTR(name),
+ };
+
+ for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
+ m->partitions[i] = DISSECTED_PARTITION_NULL;
+
+ *ret = TAKE_PTR(m);
+ return 0;
+}
+#endif
+
+static void dissected_partition_done(DissectedPartition *p) {
+ assert(p);
+
+ free(p->fstype);
+ free(p->node);
+ free(p->label);
+ free(p->decrypted_fstype);
+ free(p->decrypted_node);
+ free(p->mount_options);
+ safe_close(p->mount_node_fd);
+ safe_close(p->fsmount_fd);
+
+ *p = DISSECTED_PARTITION_NULL;
+}
+
+#if HAVE_BLKID
+static int make_partition_devname(
+ const char *whole_devname,
+ uint64_t diskseq,
+ int nr,
+ DissectImageFlags flags,
+ char **ret) {
+
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ assert(whole_devname);
+ assert(nr != 0); /* zero is not a valid partition nr */
+ assert(ret);
+
+ if (!FLAGS_SET(flags, DISSECT_IMAGE_DISKSEQ_DEVNODE) || diskseq == 0) {
+
+ /* Given a whole block device node name (e.g. /dev/sda or /dev/loop7) generate a partition
+ * device name (e.g. /dev/sda7 or /dev/loop7p5). The rule the kernel uses is simple: if whole
+ * block device node name ends in a digit, then suffix a 'p', followed by the partition
+ * number. Otherwise, just suffix the partition number without any 'p'. */
+
+ if (nr < 0) { /* whole disk? */
+ s = strdup(whole_devname);
+ if (!s)
+ return -ENOMEM;
+ } else {
+ size_t l = strlen(whole_devname);
+ if (l < 1) /* underflow check for the subtraction below */
+ return -EINVAL;
+
+ bool need_p = ascii_isdigit(whole_devname[l-1]); /* Last char a digit? */
+
+ if (asprintf(&s, "%s%s%i", whole_devname, need_p ? "p" : "", nr) < 0)
+ return -ENOMEM;
+ }
+ } else {
+ if (nr < 0) /* whole disk? */
+ r = asprintf(&s, "/dev/disk/by-diskseq/%" PRIu64, diskseq);
+ else
+ r = asprintf(&s, "/dev/disk/by-diskseq/%" PRIu64 "-part%i", diskseq, nr);
+ if (r < 0)
+ return -ENOMEM;
+ }
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+static int open_partition(
+ const char *node,
+ bool is_partition,
+ const LoopDevice *loop) {
+
+ _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+ _cleanup_close_ int fd = -EBADF;
+ dev_t devnum;
+ int r;
+
+ assert(node);
+ assert(loop);
+
+ fd = open(node, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ /* Check if the block device is a child of (or equivalent to) the originally provided one. */
+ r = block_device_new_from_fd(fd, is_partition ? BLOCK_DEVICE_LOOKUP_WHOLE_DISK : 0, &dev);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_devnum(dev, &devnum);
+ if (r < 0)
+ return r;
+
+ if (loop->devno != devnum)
+ return -ENXIO;
+
+ /* Also check diskseq. */
+ if (loop->diskseq != 0) {
+ uint64_t diskseq;
+
+ r = fd_get_diskseq(fd, &diskseq);
+ if (r < 0)
+ return r;
+
+ if (loop->diskseq != diskseq)
+ return -ENXIO;
+ }
+
+ log_debug("Opened %s (fd=%i, whole_block_devnum=" DEVNUM_FORMAT_STR ", diskseq=%" PRIu64 ").",
+ node, fd, DEVNUM_FORMAT_VAL(loop->devno), loop->diskseq);
+ return TAKE_FD(fd);
+}
+
+static int compare_arch(Architecture a, Architecture b) {
+ if (a == b)
+ return 0;
+
+ if (a == native_architecture())
+ return 1;
+
+ if (b == native_architecture())
+ return -1;
+
+#ifdef ARCHITECTURE_SECONDARY
+ if (a == ARCHITECTURE_SECONDARY)
+ return 1;
+
+ if (b == ARCHITECTURE_SECONDARY)
+ return -1;
+#endif
+
+ return 0;
+}
+
+static int dissect_image(
+ DissectedImage *m,
+ int fd,
+ const char *devname,
+ const VeritySettings *verity,
+ const MountOptions *mount_options,
+ const ImagePolicy *policy,
+ DissectImageFlags flags) {
+
+ sd_id128_t root_uuid = SD_ID128_NULL, root_verity_uuid = SD_ID128_NULL;
+ sd_id128_t usr_uuid = SD_ID128_NULL, usr_verity_uuid = SD_ID128_NULL;
+ bool is_gpt, is_mbr, multiple_generic = false,
+ generic_rw = false, /* initialize to appease gcc */
+ generic_growfs = false;
+ _cleanup_(blkid_free_probep) blkid_probe b = NULL;
+ _cleanup_free_ char *generic_node = NULL;
+ sd_id128_t generic_uuid = SD_ID128_NULL;
+ const char *pttype = NULL, *sptuuid = NULL;
+ blkid_partlist pl;
+ int r, generic_nr = -1, n_partitions;
+
+ assert(m);
+ assert(fd >= 0);
+ assert(devname);
+ assert(!verity || verity->designator < 0 || IN_SET(verity->designator, PARTITION_ROOT, PARTITION_USR));
+ assert(!verity || verity->root_hash || verity->root_hash_size == 0);
+ assert(!verity || verity->root_hash_sig || verity->root_hash_sig_size == 0);
+ assert(!verity || (verity->root_hash || !verity->root_hash_sig));
+ assert(!((flags & DISSECT_IMAGE_GPT_ONLY) && (flags & DISSECT_IMAGE_NO_PARTITION_TABLE)));
+ assert(m->sector_size > 0);
+
+ /* Probes a disk image, and returns information about what it found in *ret.
+ *
+ * Returns -ENOPKG if no suitable partition table or file system could be found.
+ * Returns -EADDRNOTAVAIL if a root hash was specified but no matching root/verity partitions found.
+ * Returns -ENXIO if we couldn't find any partition suitable as root or /usr partition
+ * Returns -ENOTUNIQ if we only found multiple generic partitions and thus don't know what to do with that
+ * Returns -ERFKILL if image doesn't match image policy
+ * Returns -EBADR if verity data was provided externally for an image that has a GPT partition table (i.e. is not just a naked fs)
+ * Returns -EPROTONOSUPPORT if DISSECT_IMAGE_ADD_PARTITION_DEVICES is set but the block device does not have partition logic enabled
+ * Returns -ENOMSG if we didn't find a single usable partition (and DISSECT_IMAGE_REFUSE_EMPTY is set) */
+
+ uint64_t diskseq = m->loop ? m->loop->diskseq : 0;
+
+ if (verity && verity->root_hash) {
+ sd_id128_t fsuuid, vuuid;
+
+ /* If a root hash is supplied, then we use the root partition that has a UUID that match the
+ * first 128-bit of the root hash. And we use the verity partition that has a UUID that match
+ * the final 128-bit. */
+
+ if (verity->root_hash_size < sizeof(sd_id128_t))
+ return -EINVAL;
+
+ memcpy(&fsuuid, verity->root_hash, sizeof(sd_id128_t));
+ memcpy(&vuuid, (const uint8_t*) verity->root_hash + verity->root_hash_size - sizeof(sd_id128_t), sizeof(sd_id128_t));
+
+ if (sd_id128_is_null(fsuuid))
+ return -EINVAL;
+ if (sd_id128_is_null(vuuid))
+ return -EINVAL;
+
+ /* If the verity data declares it's for the /usr partition, then search for that, in all
+ * other cases assume it's for the root partition. */
+ if (verity->designator == PARTITION_USR) {
+ usr_uuid = fsuuid;
+ usr_verity_uuid = vuuid;
+ } else {
+ root_uuid = fsuuid;
+ root_verity_uuid = vuuid;
+ }
+ }
+
+ b = blkid_new_probe();
+ if (!b)
+ return -ENOMEM;
+
+ errno = 0;
+ r = blkid_probe_set_device(b, fd, 0, 0);
+ if (r != 0)
+ return errno_or_else(ENOMEM);
+
+ errno = 0;
+ r = blkid_probe_set_sectorsize(b, m->sector_size);
+ if (r != 0)
+ return errno_or_else(EIO);
+
+ if ((flags & DISSECT_IMAGE_GPT_ONLY) == 0) {
+ /* Look for file system superblocks, unless we only shall look for GPT partition tables */
+ blkid_probe_enable_superblocks(b, 1);
+ blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE|BLKID_SUBLKS_USAGE|BLKID_SUBLKS_UUID);
+ }
+
+ blkid_probe_enable_partitions(b, 1);
+ blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
+
+ errno = 0;
+ r = blkid_do_safeprobe(b);
+ if (r == _BLKID_SAFEPROBE_ERROR)
+ return errno_or_else(EIO);
+ if (IN_SET(r, _BLKID_SAFEPROBE_AMBIGUOUS, _BLKID_SAFEPROBE_NOT_FOUND))
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to identify any partition table.");
+
+ assert(r == _BLKID_SAFEPROBE_FOUND);
+
+ if ((!(flags & DISSECT_IMAGE_GPT_ONLY) &&
+ (flags & DISSECT_IMAGE_GENERIC_ROOT)) ||
+ (flags & DISSECT_IMAGE_NO_PARTITION_TABLE)) {
+ const char *usage = NULL;
+
+ /* If flags permit this, also allow using non-partitioned single-filesystem images */
+
+ (void) blkid_probe_lookup_value(b, "USAGE", &usage, NULL);
+ if (STRPTR_IN_SET(usage, "filesystem", "crypto")) {
+ _cleanup_free_ char *t = NULL, *n = NULL, *o = NULL;
+ const char *fstype = NULL, *options = NULL, *suuid = NULL;
+ _cleanup_close_ int mount_node_fd = -EBADF;
+ sd_id128_t uuid = SD_ID128_NULL;
+ PartitionPolicyFlags found_flags;
+ bool encrypted;
+
+ /* OK, we have found a file system, that's our root partition then. */
+
+ r = image_policy_may_use(policy, PARTITION_ROOT);
+ if (r < 0)
+ return r;
+ if (r == 0) /* policy says ignore this, so we ignore it */
+ return -ENOPKG;
+
+ (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
+ (void) blkid_probe_lookup_value(b, "UUID", &suuid, NULL);
+
+ encrypted = streq_ptr(fstype, "crypto_LUKS");
+
+ if (verity_settings_data_covers(verity, PARTITION_ROOT))
+ found_flags = verity->root_hash_sig ? PARTITION_POLICY_SIGNED : PARTITION_POLICY_VERITY;
+ else
+ found_flags = encrypted ? PARTITION_POLICY_ENCRYPTED : PARTITION_POLICY_UNPROTECTED;
+
+ r = image_policy_check_protection(policy, PARTITION_ROOT, found_flags);
+ if (r < 0)
+ return r;
+
+ r = image_policy_check_partition_flags(policy, PARTITION_ROOT, 0); /* we have no gpt partition flags, hence check against all bits off */
+ if (r < 0)
+ return r;
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_PIN_PARTITION_DEVICES)) {
+ mount_node_fd = open_partition(devname, /* is_partition = */ false, m->loop);
+ if (mount_node_fd < 0)
+ return mount_node_fd;
+ }
+
+ if (fstype) {
+ t = strdup(fstype);
+ if (!t)
+ return -ENOMEM;
+ }
+
+ if (suuid) {
+ /* blkid will return FAT's serial number as UUID, hence it is quite possible
+ * that parsing this will fail. We'll ignore the ID, since it's just too
+ * short to be useful as tru identifier. */
+ r = sd_id128_from_string(suuid, &uuid);
+ if (r < 0)
+ log_debug_errno(r, "Failed to parse file system UUID '%s', ignoring: %m", suuid);
+ }
+
+ r = make_partition_devname(devname, diskseq, -1, flags, &n);
+ if (r < 0)
+ return r;
+
+ m->single_file_system = true;
+ m->encrypted = encrypted;
+
+ m->has_verity = verity && verity->data_path;
+ m->verity_ready = verity_settings_data_covers(verity, PARTITION_ROOT);
+
+ m->has_verity_sig = false; /* signature not embedded, must be specified */
+ m->verity_sig_ready = m->verity_ready && verity->root_hash_sig;
+
+ m->image_uuid = uuid;
+
+ options = mount_options_from_designator(mount_options, PARTITION_ROOT);
+ if (options) {
+ o = strdup(options);
+ if (!o)
+ return -ENOMEM;
+ }
+
+ m->partitions[PARTITION_ROOT] = (DissectedPartition) {
+ .found = true,
+ .rw = !m->verity_ready && !fstype_is_ro(fstype),
+ .partno = -1,
+ .architecture = _ARCHITECTURE_INVALID,
+ .fstype = TAKE_PTR(t),
+ .node = TAKE_PTR(n),
+ .mount_options = TAKE_PTR(o),
+ .mount_node_fd = TAKE_FD(mount_node_fd),
+ .offset = 0,
+ .size = UINT64_MAX,
+ .fsmount_fd = -EBADF,
+ };
+
+ return 0;
+ }
+ }
+
+ (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
+ if (!pttype)
+ return -ENOPKG;
+
+ is_gpt = streq_ptr(pttype, "gpt");
+ is_mbr = streq_ptr(pttype, "dos");
+
+ if (!is_gpt && ((flags & DISSECT_IMAGE_GPT_ONLY) || !is_mbr))
+ return -ENOPKG;
+
+ /* We support external verity data partitions only if the image has no partition table */
+ if (verity && verity->data_path)
+ return -EBADR;
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_ADD_PARTITION_DEVICES)) {
+ /* Safety check: refuse block devices that carry a partition table but for which the kernel doesn't
+ * do partition scanning. */
+ r = blockdev_partscan_enabled(fd);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EPROTONOSUPPORT;
+ }
+
+ (void) blkid_probe_lookup_value(b, "PTUUID", &sptuuid, NULL);
+ if (sptuuid) {
+ r = sd_id128_from_string(sptuuid, &m->image_uuid);
+ if (r < 0)
+ log_debug_errno(r, "Failed to parse partition table UUID '%s', ignoring: %m", sptuuid);
+ }
+
+ errno = 0;
+ pl = blkid_probe_get_partitions(b);
+ if (!pl)
+ return errno_or_else(ENOMEM);
+
+ errno = 0;
+ n_partitions = blkid_partlist_numof_partitions(pl);
+ if (n_partitions < 0)
+ return errno_or_else(EIO);
+
+ for (int i = 0; i < n_partitions; i++) {
+ _cleanup_free_ char *node = NULL;
+ unsigned long long pflags;
+ blkid_loff_t start, size;
+ blkid_partition pp;
+ int nr;
+
+ errno = 0;
+ pp = blkid_partlist_get_partition(pl, i);
+ if (!pp)
+ return errno_or_else(EIO);
+
+ pflags = blkid_partition_get_flags(pp);
+
+ errno = 0;
+ nr = blkid_partition_get_partno(pp);
+ if (nr < 0)
+ return errno_or_else(EIO);
+
+ errno = 0;
+ start = blkid_partition_get_start(pp);
+ if (start < 0)
+ return errno_or_else(EIO);
+
+ assert((uint64_t) start < UINT64_MAX/512);
+
+ errno = 0;
+ size = blkid_partition_get_size(pp);
+ if (size < 0)
+ return errno_or_else(EIO);
+
+ assert((uint64_t) size < UINT64_MAX/512);
+
+ /* While probing we need the non-diskseq device node name to access the thing, hence mask off
+ * DISSECT_IMAGE_DISKSEQ_DEVNODE. */
+ r = make_partition_devname(devname, diskseq, nr, flags & ~DISSECT_IMAGE_DISKSEQ_DEVNODE, &node);
+ if (r < 0)
+ return r;
+
+ /* So here's the thing: after the main ("whole") block device popped up it might take a while
+ * before the kernel fully probed the partition table. Waiting for that to finish is icky in
+ * userspace. So here's what we do instead. We issue the BLKPG_ADD_PARTITION ioctl to add the
+ * partition ourselves, racing against the kernel. Good thing is: if this call fails with
+ * EBUSY then the kernel was quicker than us, and that's totally OK, the outcome is good for
+ * us: the device node will exist. If OTOH our call was successful we won the race. Which is
+ * also good as the outcome is the same: the partition block device exists, and we can use
+ * it.
+ *
+ * Kernel returns EBUSY if there's already a partition by that number or an overlapping
+ * partition already existent. */
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_ADD_PARTITION_DEVICES)) {
+ r = block_device_add_partition(fd, node, nr, (uint64_t) start * 512, (uint64_t) size * 512);
+ if (r < 0) {
+ if (r != -EBUSY)
+ return log_debug_errno(r, "BLKPG_ADD_PARTITION failed: %m");
+
+ log_debug_errno(r, "Kernel was quicker than us in adding partition %i.", nr);
+ } else
+ log_debug("We were quicker than kernel in adding partition %i.", nr);
+ }
+
+ if (is_gpt) {
+ const char *fstype = NULL, *label;
+ sd_id128_t type_id, id;
+ GptPartitionType type;
+ bool rw = true, growfs = false;
+
+ r = blkid_partition_get_uuid_id128(pp, &id);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to read partition UUID, ignoring: %m");
+ continue;
+ }
+
+ r = blkid_partition_get_type_id128(pp, &type_id);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to read partition type UUID, ignoring: %m");
+ continue;
+ }
+
+ type = gpt_partition_type_from_uuid(type_id);
+
+ label = blkid_partition_get_name(pp); /* libblkid returns NULL here if empty */
+
+ if (IN_SET(type.designator,
+ PARTITION_HOME,
+ PARTITION_SRV,
+ PARTITION_XBOOTLDR,
+ PARTITION_TMP)) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
+ growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
+
+ } else if (type.designator == PARTITION_ESP) {
+
+ /* Note that we don't check the SD_GPT_FLAG_NO_AUTO flag for the ESP, as it is
+ * not defined there. We instead check the SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL, as
+ * recommended by the UEFI spec (See "12.3.3 Number and Location of System
+ * Partitions"). */
+
+ if (pflags & SD_GPT_FLAG_NO_BLOCK_IO_PROTOCOL)
+ continue;
+
+ fstype = "vfat";
+
+ } else if (type.designator == PARTITION_ROOT) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ /* If a root ID is specified, ignore everything but the root id */
+ if (!sd_id128_is_null(root_uuid) && !sd_id128_equal(root_uuid, id))
+ continue;
+
+ rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
+ growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
+
+ } else if (type.designator == PARTITION_ROOT_VERITY) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ m->has_verity = true;
+
+ /* If no verity configuration is specified, then don't do verity */
+ if (!verity)
+ continue;
+ if (verity->designator >= 0 && verity->designator != PARTITION_ROOT)
+ continue;
+
+ /* If root hash is specified, then ignore everything but the root id */
+ if (!sd_id128_is_null(root_verity_uuid) && !sd_id128_equal(root_verity_uuid, id))
+ continue;
+
+ fstype = "DM_verity_hash";
+ rw = false;
+
+ } else if (type.designator == PARTITION_ROOT_VERITY_SIG) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ m->has_verity_sig = true;
+
+ if (!verity)
+ continue;
+ if (verity->designator >= 0 && verity->designator != PARTITION_ROOT)
+ continue;
+
+ fstype = "verity_hash_signature";
+ rw = false;
+
+ } else if (type.designator == PARTITION_USR) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ /* If a usr ID is specified, ignore everything but the usr id */
+ if (!sd_id128_is_null(usr_uuid) && !sd_id128_equal(usr_uuid, id))
+ continue;
+
+ rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
+ growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
+
+ } else if (type.designator == PARTITION_USR_VERITY) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ m->has_verity = true;
+
+ if (!verity)
+ continue;
+ if (verity->designator >= 0 && verity->designator != PARTITION_USR)
+ continue;
+
+ /* If usr hash is specified, then ignore everything but the usr id */
+ if (!sd_id128_is_null(usr_verity_uuid) && !sd_id128_equal(usr_verity_uuid, id))
+ continue;
+
+ fstype = "DM_verity_hash";
+ rw = false;
+
+ } else if (type.designator == PARTITION_USR_VERITY_SIG) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ m->has_verity_sig = true;
+
+ if (!verity)
+ continue;
+ if (verity->designator >= 0 && verity->designator != PARTITION_USR)
+ continue;
+
+ fstype = "verity_hash_signature";
+ rw = false;
+
+ } else if (type.designator == PARTITION_SWAP) {
+
+ check_partition_flags(node, pflags, SD_GPT_FLAG_NO_AUTO);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ /* Note: we don't set fstype = "swap" here, because we still need to probe if
+ * it might be encrypted (i.e. fstype "crypt_LUKS") or unencrypted
+ * (i.e. fstype "swap"), and the only way to figure that out is via fstype
+ * probing. */
+
+ /* We don't have a designator for SD_GPT_LINUX_GENERIC so check the UUID instead. */
+ } else if (sd_id128_equal(type.uuid, SD_GPT_LINUX_GENERIC)) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ if (generic_node)
+ multiple_generic = true;
+ else {
+ generic_nr = nr;
+ generic_rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
+ generic_growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
+ generic_uuid = id;
+ generic_node = TAKE_PTR(node);
+ }
+
+ } else if (type.designator == PARTITION_VAR) {
+
+ check_partition_flags(node, pflags,
+ SD_GPT_FLAG_NO_AUTO | SD_GPT_FLAG_READ_ONLY | SD_GPT_FLAG_GROWFS);
+
+ if (pflags & SD_GPT_FLAG_NO_AUTO)
+ continue;
+
+ if (!FLAGS_SET(flags, DISSECT_IMAGE_RELAX_VAR_CHECK)) {
+ sd_id128_t var_uuid;
+
+ /* For /var we insist that the uuid of the partition matches the
+ * HMAC-SHA256 of the /var GPT partition type uuid, keyed by machine
+ * ID. Why? Unlike the other partitions /var is inherently
+ * installation specific, hence we need to be careful not to mount it
+ * in the wrong installation. By hashing the partition UUID from
+ * /etc/machine-id we can securely bind the partition to the
+ * installation. */
+
+ r = sd_id128_get_machine_app_specific(SD_GPT_VAR, &var_uuid);
+ if (r < 0)
+ return r;
+
+ if (!sd_id128_equal(var_uuid, id)) {
+ log_debug("Found a /var/ partition, but its UUID didn't match our expectations "
+ "(found: " SD_ID128_UUID_FORMAT_STR ", expected: " SD_ID128_UUID_FORMAT_STR "), ignoring.",
+ SD_ID128_FORMAT_VAL(id), SD_ID128_FORMAT_VAL(var_uuid));
+ continue;
+ }
+ }
+
+ rw = !(pflags & SD_GPT_FLAG_READ_ONLY);
+ growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS);
+ }
+
+ if (type.designator != _PARTITION_DESIGNATOR_INVALID) {
+ _cleanup_free_ char *t = NULL, *o = NULL, *l = NULL, *n = NULL;
+ _cleanup_close_ int mount_node_fd = -EBADF;
+ const char *options = NULL;
+
+ r = image_policy_may_use(policy, type.designator);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ /* Policy says: ignore; Remember this fact, so that we later can distinguish between "found but ignored" and "not found at all" */
+
+ if (!m->partitions[type.designator].found)
+ m->partitions[type.designator].ignored = true;
+
+ continue;
+ }
+
+ if (m->partitions[type.designator].found) {
+ int c;
+
+ /* For most partition types the first one we see wins. Except for the
+ * rootfs and /usr, where we do a version compare of the label, and
+ * let the newest version win. This permits a simple A/B versioning
+ * scheme in OS images. */
+
+ c = compare_arch(type.arch, m->partitions[type.designator].architecture);
+ if (c < 0) /* the arch we already found is better than the one we found now */
+ continue;
+ if (c == 0 && /* same arch? then go by version in label */
+ (!partition_designator_is_versioned(type.designator) ||
+ strverscmp_improved(label, m->partitions[type.designator].label) <= 0))
+ continue;
+
+ dissected_partition_done(m->partitions + type.designator);
+ }
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_PIN_PARTITION_DEVICES) &&
+ type.designator != PARTITION_SWAP) {
+ mount_node_fd = open_partition(node, /* is_partition = */ true, m->loop);
+ if (mount_node_fd < 0)
+ return mount_node_fd;
+ }
+
+ r = make_partition_devname(devname, diskseq, nr, flags, &n);
+ if (r < 0)
+ return r;
+
+ if (fstype) {
+ t = strdup(fstype);
+ if (!t)
+ return -ENOMEM;
+ }
+
+ if (label) {
+ l = strdup(label);
+ if (!l)
+ return -ENOMEM;
+ }
+
+ options = mount_options_from_designator(mount_options, type.designator);
+ if (options) {
+ o = strdup(options);
+ if (!o)
+ return -ENOMEM;
+ }
+
+ m->partitions[type.designator] = (DissectedPartition) {
+ .found = true,
+ .partno = nr,
+ .rw = rw,
+ .growfs = growfs,
+ .architecture = type.arch,
+ .node = TAKE_PTR(n),
+ .fstype = TAKE_PTR(t),
+ .label = TAKE_PTR(l),
+ .uuid = id,
+ .mount_options = TAKE_PTR(o),
+ .mount_node_fd = TAKE_FD(mount_node_fd),
+ .offset = (uint64_t) start * 512,
+ .size = (uint64_t) size * 512,
+ .gpt_flags = pflags,
+ .fsmount_fd = -EBADF,
+ };
+ }
+
+ } else if (is_mbr) {
+
+ switch (blkid_partition_get_type(pp)) {
+
+ case 0x83: /* Linux partition */
+
+ if (pflags != 0x80) /* Bootable flag */
+ continue;
+
+ if (generic_node)
+ multiple_generic = true;
+ else {
+ generic_nr = nr;
+ generic_rw = true;
+ generic_growfs = false;
+ generic_node = TAKE_PTR(node);
+ }
+
+ break;
+
+ case 0xEA: { /* Boot Loader Spec extended $BOOT partition */
+ _cleanup_close_ int mount_node_fd = -EBADF;
+ _cleanup_free_ char *o = NULL, *n = NULL;
+ sd_id128_t id = SD_ID128_NULL;
+ const char *options = NULL;
+
+ r = image_policy_may_use(policy, PARTITION_XBOOTLDR);
+ if (r < 0)
+ return r;
+ if (r == 0) { /* policy says: ignore */
+ if (!m->partitions[PARTITION_XBOOTLDR].found)
+ m->partitions[PARTITION_XBOOTLDR].ignored = true;
+
+ continue;
+ }
+
+ /* First one wins */
+ if (m->partitions[PARTITION_XBOOTLDR].found)
+ continue;
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_PIN_PARTITION_DEVICES)) {
+ mount_node_fd = open_partition(node, /* is_partition = */ true, m->loop);
+ if (mount_node_fd < 0)
+ return mount_node_fd;
+ }
+
+ (void) blkid_partition_get_uuid_id128(pp, &id);
+
+ r = make_partition_devname(devname, diskseq, nr, flags, &n);
+ if (r < 0)
+ return r;
+
+ options = mount_options_from_designator(mount_options, PARTITION_XBOOTLDR);
+ if (options) {
+ o = strdup(options);
+ if (!o)
+ return -ENOMEM;
+ }
+
+ m->partitions[PARTITION_XBOOTLDR] = (DissectedPartition) {
+ .found = true,
+ .partno = nr,
+ .rw = true,
+ .growfs = false,
+ .architecture = _ARCHITECTURE_INVALID,
+ .node = TAKE_PTR(n),
+ .uuid = id,
+ .mount_options = TAKE_PTR(o),
+ .mount_node_fd = TAKE_FD(mount_node_fd),
+ .offset = (uint64_t) start * 512,
+ .size = (uint64_t) size * 512,
+ .fsmount_fd = -EBADF,
+ };
+
+ break;
+ }}
+ }
+ }
+
+ if (!m->partitions[PARTITION_ROOT].found &&
+ (m->partitions[PARTITION_ROOT_VERITY].found ||
+ m->partitions[PARTITION_ROOT_VERITY_SIG].found))
+ return -EADDRNOTAVAIL; /* Verity found but no matching rootfs? Something is off, refuse. */
+
+ /* Hmm, we found a signature partition but no Verity data? Something is off. */
+ if (m->partitions[PARTITION_ROOT_VERITY_SIG].found && !m->partitions[PARTITION_ROOT_VERITY].found)
+ return -EADDRNOTAVAIL;
+
+ if (!m->partitions[PARTITION_USR].found &&
+ (m->partitions[PARTITION_USR_VERITY].found ||
+ m->partitions[PARTITION_USR_VERITY_SIG].found))
+ return -EADDRNOTAVAIL; /* as above */
+
+ /* as above */
+ if (m->partitions[PARTITION_USR_VERITY_SIG].found && !m->partitions[PARTITION_USR_VERITY].found)
+ return -EADDRNOTAVAIL;
+
+ /* If root and /usr are combined then insist that the architecture matches */
+ if (m->partitions[PARTITION_ROOT].found &&
+ m->partitions[PARTITION_USR].found &&
+ (m->partitions[PARTITION_ROOT].architecture >= 0 &&
+ m->partitions[PARTITION_USR].architecture >= 0 &&
+ m->partitions[PARTITION_ROOT].architecture != m->partitions[PARTITION_USR].architecture))
+ return -EADDRNOTAVAIL;
+
+ if (!m->partitions[PARTITION_ROOT].found &&
+ !m->partitions[PARTITION_USR].found &&
+ (flags & DISSECT_IMAGE_GENERIC_ROOT) &&
+ (!verity || !verity->root_hash || verity->designator != PARTITION_USR)) {
+
+ /* OK, we found nothing usable, then check if there's a single generic partition, and use
+ * that. If the root hash was set however, then we won't fall back to a generic node, because
+ * the root hash decides. */
+
+ /* If we didn't find a properly marked root partition, but we did find a single suitable
+ * generic Linux partition, then use this as root partition, if the caller asked for it. */
+ if (multiple_generic)
+ return -ENOTUNIQ;
+
+ /* If we didn't find a generic node, then we can't fix this up either */
+ if (generic_node) {
+ r = image_policy_may_use(policy, PARTITION_ROOT);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ /* Policy says: ignore; remember that we did */
+ m->partitions[PARTITION_ROOT].ignored = true;
+ else {
+ _cleanup_close_ int mount_node_fd = -EBADF;
+ _cleanup_free_ char *o = NULL, *n = NULL;
+ const char *options;
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_PIN_PARTITION_DEVICES)) {
+ mount_node_fd = open_partition(generic_node, /* is_partition = */ true, m->loop);
+ if (mount_node_fd < 0)
+ return mount_node_fd;
+ }
+
+ r = make_partition_devname(devname, diskseq, generic_nr, flags, &n);
+ if (r < 0)
+ return r;
+
+ options = mount_options_from_designator(mount_options, PARTITION_ROOT);
+ if (options) {
+ o = strdup(options);
+ if (!o)
+ return -ENOMEM;
+ }
+
+ assert(generic_nr >= 0);
+ m->partitions[PARTITION_ROOT] = (DissectedPartition) {
+ .found = true,
+ .rw = generic_rw,
+ .growfs = generic_growfs,
+ .partno = generic_nr,
+ .architecture = _ARCHITECTURE_INVALID,
+ .node = TAKE_PTR(n),
+ .uuid = generic_uuid,
+ .mount_options = TAKE_PTR(o),
+ .mount_node_fd = TAKE_FD(mount_node_fd),
+ .offset = UINT64_MAX,
+ .size = UINT64_MAX,
+ .fsmount_fd = -EBADF,
+ };
+ }
+ }
+ }
+
+ /* 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 */
+ if (FLAGS_SET(flags, DISSECT_IMAGE_REQUIRE_ROOT) &&
+ !(m->partitions[PARTITION_ROOT].found || (m->partitions[PARTITION_USR].found && FLAGS_SET(flags, DISSECT_IMAGE_USR_NO_ROOT))))
+ return -ENXIO;
+
+ if (m->partitions[PARTITION_ROOT_VERITY].found) {
+ /* We only support one verity partition per image, i.e. can't do for both /usr and root fs */
+ if (m->partitions[PARTITION_USR_VERITY].found)
+ return -ENOTUNIQ;
+
+ /* We don't support verity enabled root with a split out /usr. Neither with nor without
+ * verity there. (Note that we do support verity-less root with verity-full /usr, though.) */
+ if (m->partitions[PARTITION_USR].found)
+ return -EADDRNOTAVAIL;
+ }
+
+ if (verity) {
+ /* If a verity designator is specified, then insist that the matching partition exists */
+ if (verity->designator >= 0 && !m->partitions[verity->designator].found)
+ return -EADDRNOTAVAIL;
+
+ bool have_verity_sig_partition;
+ if (verity->designator >= 0)
+ have_verity_sig_partition = m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR_VERITY_SIG : PARTITION_ROOT_VERITY_SIG].found;
+ else
+ have_verity_sig_partition = m->partitions[PARTITION_USR_VERITY_SIG].found || m->partitions[PARTITION_ROOT_VERITY_SIG].found;
+
+ if (verity->root_hash) {
+ /* If we have an explicit root hash and found the partitions for it, then we are ready to use
+ * Verity, set things up for it */
+
+ if (verity->designator < 0 || verity->designator == PARTITION_ROOT) {
+ if (!m->partitions[PARTITION_ROOT_VERITY].found || !m->partitions[PARTITION_ROOT].found)
+ return -EADDRNOTAVAIL;
+
+ /* If we found a verity setup, then the root partition is necessarily read-only. */
+ m->partitions[PARTITION_ROOT].rw = false;
+ m->verity_ready = true;
+
+ } else {
+ assert(verity->designator == PARTITION_USR);
+
+ if (!m->partitions[PARTITION_USR_VERITY].found || !m->partitions[PARTITION_USR].found)
+ return -EADDRNOTAVAIL;
+
+ m->partitions[PARTITION_USR].rw = false;
+ m->verity_ready = true;
+ }
+
+ if (m->verity_ready)
+ m->verity_sig_ready = verity->root_hash_sig || have_verity_sig_partition;
+
+ } else if (have_verity_sig_partition) {
+
+ /* If we found an embedded signature partition, we are ready, too. */
+
+ m->verity_ready = m->verity_sig_ready = true;
+ if (verity->designator >= 0)
+ m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR : PARTITION_ROOT].rw = false;
+ else if (m->partitions[PARTITION_USR_VERITY_SIG].found)
+ m->partitions[PARTITION_USR].rw = false;
+ else if (m->partitions[PARTITION_ROOT_VERITY_SIG].found)
+ m->partitions[PARTITION_ROOT].rw = false;
+ }
+ }
+
+ bool any = false;
+
+ /* After we discovered all partitions let's see if the verity requirements match the policy. (Note:
+ * we don't check encryption requirements here, because we haven't probed the file system yet, hence
+ * don't know if this is encrypted or not) */
+ for (PartitionDesignator di = 0; di < _PARTITION_DESIGNATOR_MAX; di++) {
+ PartitionDesignator vi, si;
+ PartitionPolicyFlags found_flags;
+
+ any = any || m->partitions[di].found;
+
+ vi = partition_verity_of(di);
+ si = partition_verity_sig_of(di);
+
+ /* Determine the verity protection level for this partition. */
+ found_flags = m->partitions[di].found ?
+ (vi >= 0 && m->partitions[vi].found ?
+ (si >= 0 && m->partitions[si].found ? PARTITION_POLICY_SIGNED : PARTITION_POLICY_VERITY) :
+ PARTITION_POLICY_ENCRYPTED|PARTITION_POLICY_UNPROTECTED) :
+ (m->partitions[di].ignored ? PARTITION_POLICY_UNUSED : PARTITION_POLICY_ABSENT);
+
+ r = image_policy_check_protection(policy, di, found_flags);
+ if (r < 0)
+ return r;
+
+ if (m->partitions[di].found) {
+ r = image_policy_check_partition_flags(policy, di, m->partitions[di].gpt_flags);
+ if (r < 0)
+ return r;
+ }
+ }
+
+ if (!any && !FLAGS_SET(flags, DISSECT_IMAGE_ALLOW_EMPTY))
+ return -ENOMSG;
+
+ r = dissected_image_probe_filesystems(m, fd, policy);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+#endif
+
+int dissect_image_file(
+ const char *path,
+ const VeritySettings *verity,
+ const MountOptions *mount_options,
+ const ImagePolicy *image_policy,
+ DissectImageFlags flags,
+ DissectedImage **ret) {
+
+#if HAVE_BLKID
+ _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+ _cleanup_close_ int fd = -EBADF;
+ int r;
+
+ assert(path);
+
+ fd = open(path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ r = fd_verify_regular(fd);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_new(path, &m);
+ if (r < 0)
+ return r;
+
+ r = probe_sector_size(fd, &m->sector_size);
+ if (r < 0)
+ return r;
+
+ r = dissect_image(m, fd, path, verity, mount_options, image_policy, flags);
+ if (r < 0)
+ return r;
+
+ if (ret)
+ *ret = TAKE_PTR(m);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+int dissect_log_error(int log_level, int r, const char *name, const VeritySettings *verity) {
+ assert(log_level >= 0 && log_level <= LOG_DEBUG);
+ assert(name);
+
+ switch (r) {
+
+ case 0 ... INT_MAX: /* success! */
+ return r;
+
+ case -EOPNOTSUPP:
+ return log_full_errno(log_level, r, "Dissecting images is not supported, compiled without blkid support.");
+
+ case -ENOPKG:
+ return log_full_errno(log_level, r, "%s: Couldn't identify a suitable partition table or file system.", name);
+
+ case -ENOMEDIUM:
+ return log_full_errno(log_level, r, "%s: The image does not pass os-release/extension-release validation.", name);
+
+ case -EADDRNOTAVAIL:
+ return log_full_errno(log_level, r, "%s: No root partition for specified root hash found.", name);
+
+ case -ENOTUNIQ:
+ return log_full_errno(log_level, r, "%s: Multiple suitable root partitions found in image.", name);
+
+ case -ENXIO:
+ return log_full_errno(log_level, r, "%s: No suitable root partition found in image.", name);
+
+ case -EPROTONOSUPPORT:
+ return log_full_errno(log_level, r, "Device '%s' is a loopback block device with partition scanning turned off, please turn it on.", name);
+
+ case -ENOTBLK:
+ return log_full_errno(log_level, r, "%s: Image is not a block device.", name);
+
+ case -EBADR:
+ return log_full_errno(log_level, r,
+ "Combining partitioned images (such as '%s') with external Verity data (such as '%s') not supported. "
+ "(Consider setting $SYSTEMD_DISSECT_VERITY_SIDECAR=0 to disable automatic discovery of external Verity data.)",
+ name, strna(verity ? verity->data_path : NULL));
+
+ case -ERFKILL:
+ return log_full_errno(log_level, r, "%s: image does not match image policy.", name);
+
+ case -ENOMSG:
+ return log_full_errno(log_level, r, "%s: no suitable partitions found.", name);
+
+ default:
+ return log_full_errno(log_level, r, "%s: cannot dissect image: %m", name);
+ }
+}
+
+int dissect_image_file_and_warn(
+ const char *path,
+ const VeritySettings *verity,
+ const MountOptions *mount_options,
+ const ImagePolicy *image_policy,
+ DissectImageFlags flags,
+ DissectedImage **ret) {
+
+ return dissect_log_error(
+ LOG_ERR,
+ dissect_image_file(path, verity, mount_options, image_policy, flags, ret),
+ path,
+ verity);
+}
+
+DissectedImage* dissected_image_unref(DissectedImage *m) {
+ if (!m)
+ return NULL;
+
+ /* First, clear dissected partitions. */
+ for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++)
+ dissected_partition_done(m->partitions + i);
+
+ /* Second, free decrypted images. This must be after dissected_partition_done(), as freeing
+ * DecryptedImage may try to deactivate partitions. */
+ decrypted_image_unref(m->decrypted_image);
+
+ /* Third, unref LoopDevice. This must be called after the above two, as freeing LoopDevice may try to
+ * remove existing partitions on the loopback block device. */
+ loop_device_unref(m->loop);
+
+ free(m->image_name);
+ free(m->hostname);
+ strv_free(m->machine_info);
+ strv_free(m->os_release);
+ strv_free(m->initrd_release);
+ strv_free(m->confext_release);
+ strv_free(m->sysext_release);
+
+ return mfree(m);
+}
+
+static int is_loop_device(const char *path) {
+ char s[SYS_BLOCK_PATH_MAX("/../loop/")];
+ struct stat st;
+
+ assert(path);
+
+ if (stat(path, &st) < 0)
+ return -errno;
+
+ if (!S_ISBLK(st.st_mode))
+ return -ENOTBLK;
+
+ xsprintf_sys_block_path(s, "/loop/", st.st_dev);
+ if (access(s, F_OK) < 0) {
+ if (errno != ENOENT)
+ return -errno;
+
+ /* The device itself isn't a loop device, but maybe it's a partition and its parent is? */
+ xsprintf_sys_block_path(s, "/../loop/", st.st_dev);
+ if (access(s, F_OK) < 0)
+ return errno == ENOENT ? false : -errno;
+ }
+
+ return true;
+}
+
+static int run_fsck(int node_fd, const char *fstype) {
+ int r, exit_status;
+ pid_t pid;
+
+ assert(node_fd >= 0);
+ assert(fstype);
+
+ r = fsck_exists_for_fstype(fstype);
+ if (r < 0) {
+ log_debug_errno(r, "Couldn't determine whether fsck for %s exists, proceeding anyway.", fstype);
+ return 0;
+ }
+ if (r == 0) {
+ log_debug("Not checking partition %s, as fsck for %s does not exist.", FORMAT_PROC_FD_PATH(node_fd), fstype);
+ return 0;
+ }
+
+ r = safe_fork_full(
+ "(fsck)",
+ NULL,
+ &node_fd, 1, /* Leave the node fd open */
+ FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG_SIGTERM|FORK_REARRANGE_STDIO|FORK_CLOEXEC_OFF,
+ &pid);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to fork off fsck: %m");
+ if (r == 0) {
+ /* Child */
+ execlp("fsck", "fsck", "-aT", FORMAT_PROC_FD_PATH(node_fd), NULL);
+ log_open();
+ log_debug_errno(errno, "Failed to execl() fsck: %m");
+ _exit(FSCK_OPERATIONAL_ERROR);
+ }
+
+ exit_status = wait_for_terminate_and_check("fsck", pid, 0);
+ if (exit_status < 0)
+ return log_debug_errno(exit_status, "Failed to fork off fsck: %m");
+
+ if ((exit_status & ~FSCK_ERROR_CORRECTED) != FSCK_SUCCESS) {
+ log_debug("fsck failed with exit status %i.", exit_status);
+
+ if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), "File system is corrupted, refusing.");
+
+ log_debug("Ignoring fsck error.");
+ }
+
+ return 0;
+}
+
+static int fs_grow(const char *node_path, int mount_fd, const char *mount_path) {
+ _cleanup_close_ int _mount_fd = -EBADF, node_fd = -EBADF;
+ uint64_t size, newsize;
+ const char *id;
+ int r;
+
+ assert(node_path);
+ assert(mount_fd >= 0 || mount_path);
+
+ node_fd = open(node_path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+ if (node_fd < 0)
+ return log_debug_errno(errno, "Failed to open node device %s: %m", node_path);
+
+ if (ioctl(node_fd, BLKGETSIZE64, &size) != 0)
+ return log_debug_errno(errno, "Failed to get block device size of %s: %m", node_path);
+
+ if (mount_fd < 0) {
+ assert(mount_path);
+
+ _mount_fd = open(mount_path, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
+ if (_mount_fd < 0)
+ return log_debug_errno(errno, "Failed to open mounted file system %s: %m", mount_path);
+
+ mount_fd = _mount_fd;
+ } else {
+ mount_fd = fd_reopen_condition(mount_fd, O_RDONLY|O_DIRECTORY|O_CLOEXEC, O_RDONLY|O_DIRECTORY|O_CLOEXEC, &_mount_fd);
+ if (mount_fd < 0)
+ return log_debug_errno(errno, "Failed to reopen mount node: %m");
+ }
+
+ id = mount_path ?: node_path;
+
+ log_debug("Resizing \"%s\" to %"PRIu64" bytes...", id, size);
+ r = resize_fs(mount_fd, size, &newsize);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to resize \"%s\" to %"PRIu64" bytes: %m", id, size);
+
+ if (newsize == size)
+ log_debug("Successfully resized \"%s\" to %s bytes.",
+ id, FORMAT_BYTES(newsize));
+ else {
+ assert(newsize < size);
+ log_debug("Successfully resized \"%s\" to %s bytes (%"PRIu64" bytes lost due to blocksize).",
+ id, FORMAT_BYTES(newsize), size - newsize);
+ }
+
+ return 0;
+}
+
+int partition_pick_mount_options(
+ PartitionDesignator d,
+ const char *fstype,
+ bool rw,
+ bool discard,
+ char **ret_options,
+ unsigned long *ret_ms_flags) {
+
+ _cleanup_free_ char *options = NULL;
+
+ assert(ret_options);
+
+ /* Selects a baseline of bind mount flags, that should always apply.
+ *
+ * Firstly, we set MS_NODEV universally on all mounts, since we don't want to allow device nodes outside of /dev/.
+ *
+ * On /var/tmp/ we'll also set MS_NOSUID, same as we set for /tmp/ on the host.
+ *
+ * On the ESP and XBOOTLDR partitions we'll also disable symlinks, and execution. These file systems
+ * are generally untrusted (i.e. not encrypted or authenticated), and typically VFAT hence we should
+ * be as restrictive as possible, and this shouldn't hurt, since the functionality is not available
+ * there anyway. */
+
+ unsigned long flags = MS_NODEV;
+
+ if (!rw)
+ flags |= MS_RDONLY;
+
+ switch (d) {
+
+ case PARTITION_ESP:
+ case PARTITION_XBOOTLDR:
+ flags |= MS_NOSUID|MS_NOEXEC|ms_nosymfollow_supported();
+
+ /* The ESP might contain a pre-boot random seed. Let's make this unaccessible to regular
+ * userspace. ESP/XBOOTLDR is almost certainly VFAT, hence if we don't know assume it is. */
+ if (!fstype || fstype_can_umask(fstype))
+ if (!strextend_with_separator(&options, ",", "umask=0077"))
+ return -ENOMEM;
+ break;
+
+ case PARTITION_TMP:
+ flags |= MS_NOSUID;
+ break;
+
+ default:
+ break;
+ }
+
+ /* So, when you request MS_RDONLY from ext4, then this means nothing. It happily still writes to the
+ * backing storage. What's worse, the BLKRO[GS]ET flag and (in case of loopback devices)
+ * LO_FLAGS_READ_ONLY don't mean anything, they affect userspace accesses only, and write accesses
+ * from the upper file system still get propagated through to the underlying file system,
+ * unrestricted. To actually get ext4/xfs/btrfs to stop writing to the device we need to specify
+ * "norecovery" as mount option, in addition to MS_RDONLY. Yes, this sucks, since it means we need to
+ * carry a per file system table here.
+ *
+ * Note that this means that we might not be able to mount corrupted file systems as read-only
+ * anymore (since in some cases the kernel implementations will refuse mounting when corrupted,
+ * read-only and "norecovery" is specified). But I think for the case of automatically determined
+ * mount options for loopback devices this is the right choice, since otherwise using the same
+ * loopback file twice even in read-only mode, is going to fail badly sooner or later. The use case of
+ * making reuse of the immutable images "just work" is more relevant to us than having read-only
+ * access that actually modifies stuff work on such image files. Or to say this differently: if
+ * people want their file systems to be fixed up they should just open them in writable mode, where
+ * all these problems don't exist. */
+ if (!rw && fstype && fstype_can_norecovery(fstype))
+ if (!strextend_with_separator(&options, ",", "norecovery"))
+ return -ENOMEM;
+
+ if (discard && fstype && fstype_can_discard(fstype))
+ if (!strextend_with_separator(&options, ",", "discard"))
+ return -ENOMEM;
+
+ if (!ret_ms_flags) /* Fold flags into option string if ret_flags specified as NULL */
+ if (!strextend_with_separator(&options, ",",
+ FLAGS_SET(flags, MS_RDONLY) ? "ro" : "rw",
+ FLAGS_SET(flags, MS_NODEV) ? "nodev" : "dev",
+ FLAGS_SET(flags, MS_NOSUID) ? "nosuid" : "suid",
+ FLAGS_SET(flags, MS_NOEXEC) ? "noexec" : "exec",
+ FLAGS_SET(flags, MS_NOSYMFOLLOW) ? "nosymfollow" : NULL))
+ /* NB: we suppress 'symfollow' here, since it's the default, and old /bin/mount might not know it */
+ return -ENOMEM;
+
+ if (ret_ms_flags)
+ *ret_ms_flags = flags;
+
+ *ret_options = TAKE_PTR(options);
+ return 0;
+}
+
+static bool need_user_mapping(uid_t uid_shift, uid_t uid_range) {
+
+ if (!uid_is_valid(uid_shift))
+ return false;
+
+ return uid_shift != 0 || uid_range != UINT32_MAX;
+}
+
+static int mount_partition(
+ PartitionDesignator d,
+ DissectedPartition *m,
+ const char *where,
+ const char *directory,
+ uid_t uid_shift,
+ uid_t uid_range,
+ int userns_fd,
+ DissectImageFlags flags) {
+
+ _cleanup_free_ char *chased = NULL, *options = NULL;
+ const char *p = NULL, *node, *fstype = NULL;
+ bool rw, discard, grow;
+ unsigned long ms_flags;
+ int r;
+
+ assert(m);
+
+ if (!m->found)
+ return 0;
+
+ /* Check the various combinations when we can't do anything anymore */
+ if (m->fsmount_fd < 0 && m->mount_node_fd < 0)
+ return 0;
+ if (m->fsmount_fd >= 0 && !where)
+ return 0;
+ if (!where && m->mount_node_fd < 0)
+ return 0;
+
+ if (m->fsmount_fd < 0) {
+ fstype = dissected_partition_fstype(m);
+ if (!fstype)
+ return -EAFNOSUPPORT;
+
+ /* We are looking at an encrypted partition? This either means stacked encryption, or the
+ * caller didn't call dissected_image_decrypt() beforehand. Let's return a recognizable error
+ * for this case. */
+ if (streq(fstype, "crypto_LUKS"))
+ return -EUNATCH;
+
+ r = dissect_fstype_ok(fstype);
+ if (r < 0)
+ return r;
+ if (!r)
+ return -EIDRM; /* Recognizable error */
+ }
+
+ node = m->mount_node_fd < 0 ? NULL : FORMAT_PROC_FD_PATH(m->mount_node_fd);
+ rw = m->rw && !(flags & DISSECT_IMAGE_MOUNT_READ_ONLY);
+
+ discard = ((flags & DISSECT_IMAGE_DISCARD) ||
+ ((flags & DISSECT_IMAGE_DISCARD_ON_LOOP) && (m->node && is_loop_device(m->node) > 0)));
+
+ grow = rw && m->growfs && FLAGS_SET(flags, DISSECT_IMAGE_GROWFS);
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_FSCK) && rw && m->mount_node_fd >= 0 && m->fsmount_fd < 0) {
+ r = run_fsck(m->mount_node_fd, fstype);
+ if (r < 0)
+ return r;
+ }
+
+ if (where) {
+ if (directory) {
+ /* Automatically create missing mount points inside the image, if necessary. */
+ r = mkdir_p_root(where, directory, uid_shift, (gid_t) uid_shift, 0755, NULL);
+ if (r < 0 && r != -EROFS)
+ return r;
+
+ r = chase(directory, where, CHASE_PREFIX_ROOT, &chased, NULL);
+ if (r < 0)
+ return r;
+
+ p = chased;
+ } else {
+ /* Create top-level mount if missing – but only if this is asked for. This won't modify the
+ * image (as the branch above does) but the host hierarchy, and the created directory might
+ * survive our mount in the host hierarchy hence. */
+ if (FLAGS_SET(flags, DISSECT_IMAGE_MKDIR)) {
+ r = mkdir_p(where, 0755);
+ if (r < 0)
+ return r;
+ }
+
+ p = where;
+ }
+ }
+
+ if (m->fsmount_fd < 0) {
+ r = partition_pick_mount_options(d, fstype, rw, discard, &options, &ms_flags);
+ if (r < 0)
+ return r;
+
+ if (need_user_mapping(uid_shift, uid_range) && fstype_can_uid_gid(fstype)) {
+ _cleanup_free_ char *uid_option = NULL;
+
+ if (asprintf(&uid_option, "uid=" UID_FMT ",gid=" GID_FMT, uid_shift, (gid_t) uid_shift) < 0)
+ return -ENOMEM;
+
+ if (!strextend_with_separator(&options, ",", uid_option))
+ return -ENOMEM;
+
+ userns_fd = -EBADF; /* Not needed */
+ }
+
+ if (!isempty(m->mount_options))
+ if (!strextend_with_separator(&options, ",", m->mount_options))
+ return -ENOMEM;
+ }
+
+ if (p) {
+ if (m->fsmount_fd >= 0) {
+ /* Case #1: Attach existing fsmount fd to the file system */
+
+ r = mount_exchange_graceful(
+ m->fsmount_fd,
+ p,
+ FLAGS_SET(flags, DISSECT_IMAGE_TRY_ATOMIC_MOUNT_EXCHANGE));
+ if (r < 0)
+ return log_debug_errno(r, "Failed to mount image on '%s': %m", p);
+
+ } else {
+ assert(node);
+
+ /* Case #2: Mount directly into place */
+ r = mount_nofollow_verbose(LOG_DEBUG, node, p, fstype, ms_flags, options);
+ if (r < 0)
+ return r;
+
+ if (grow)
+ (void) fs_grow(node, -EBADF, p);
+
+ if (userns_fd >= 0) {
+ r = remount_idmap_fd(STRV_MAKE(p), userns_fd);
+ if (r < 0)
+ return r;
+ }
+ }
+ } else {
+ assert(node);
+
+ /* Case #3: Create fsmount fd */
+
+ m->fsmount_fd = make_fsmount(LOG_DEBUG, node, fstype, ms_flags, options, userns_fd);
+ if (m->fsmount_fd < 0)
+ return m->fsmount_fd;
+
+ if (grow)
+ (void) fs_grow(node, m->fsmount_fd, NULL);
+ }
+
+ return 1;
+}
+
+static int mount_root_tmpfs(const char *where, uid_t uid_shift, uid_t uid_range, DissectImageFlags flags) {
+ _cleanup_free_ char *options = NULL;
+ int r;
+
+ assert(where);
+
+ /* For images that contain /usr/ but no rootfs, let's mount rootfs as tmpfs */
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_MKDIR)) {
+ r = mkdir_p(where, 0755);
+ if (r < 0)
+ return r;
+ }
+
+ if (need_user_mapping(uid_shift, uid_range)) {
+ if (asprintf(&options, "uid=" UID_FMT ",gid=" GID_FMT, uid_shift, (gid_t) uid_shift) < 0)
+ return -ENOMEM;
+ }
+
+ r = mount_nofollow_verbose(LOG_DEBUG, "rootfs", where, "tmpfs", MS_NODEV, options);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int mount_point_is_available(const char *where, const char *path, bool missing_ok) {
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ /* Check whether <path> is suitable as a mountpoint, i.e. is an empty directory
+ * or does not exist at all (when missing_ok). */
+
+ r = chase(path, where, CHASE_PREFIX_ROOT, &p, NULL);
+ if (r == -ENOENT)
+ return missing_ok;
+ if (r < 0)
+ return log_debug_errno(r, "Failed to chase \"%s\": %m", path);
+
+ r = dir_is_empty(p, /* ignore_hidden_or_backup= */ false);
+ if (r == -ENOTDIR)
+ return false;
+ if (r < 0)
+ return log_debug_errno(r, "Failed to check directory \"%s\": %m", p);
+ return r > 0;
+}
+
+int dissected_image_mount(
+ DissectedImage *m,
+ const char *where,
+ uid_t uid_shift,
+ uid_t uid_range,
+ int userns_fd,
+ DissectImageFlags flags) {
+
+ _cleanup_close_ int my_userns_fd = -EBADF;
+ int r;
+
+ assert(m);
+
+ /* If 'where' is NULL then we'll use the new mount API to create fsmount() fds for the mounts and
+ * store them in DissectedPartition.fsmount_fd.
+ *
+ * If 'where' is not NULL then we'll either mount the partitions to the right places ourselves,
+ * or use DissectedPartition.fsmount_fd and bind it to the right places.
+ *
+ * This allows splitting the setting up up the superblocks and the binding to file systems paths into
+ * two distinct and differently privileged components: one that gets the fsmount fds, and the other
+ * that then applies them.
+ *
+ * Returns:
+ *
+ * -ENXIO → No root partition found
+ * -EMEDIUMTYPE → DISSECT_IMAGE_VALIDATE_OS set but no os-release/extension-release file found
+ * -EUNATCH → Encrypted partition found for which no dm-crypt was set up yet
+ * -EUCLEAN → fsck for file system failed
+ * -EBUSY → File system already mounted/used elsewhere (kernel)
+ * -EAFNOSUPPORT → File system type not supported or not known
+ * -EIDRM → File system is not among allowlisted "common" file systems
+ */
+
+ if (!where && (flags & (DISSECT_IMAGE_VALIDATE_OS|DISSECT_IMAGE_VALIDATE_OS_EXT)) != 0)
+ return -EOPNOTSUPP; /* for now, not supported */
+
+ if (!(m->partitions[PARTITION_ROOT].found ||
+ (m->partitions[PARTITION_USR].found && FLAGS_SET(flags, DISSECT_IMAGE_USR_NO_ROOT))))
+ return -ENXIO; /* Require a root fs or at least a /usr/ fs (the latter is subject to a flag of its own) */
+
+ if (userns_fd < 0 && need_user_mapping(uid_shift, uid_range) && FLAGS_SET(flags, DISSECT_IMAGE_MOUNT_IDMAPPED)) {
+
+ my_userns_fd = make_userns(uid_shift, uid_range, UID_INVALID, REMOUNT_IDMAPPING_HOST_ROOT);
+ if (my_userns_fd < 0)
+ return my_userns_fd;
+
+ userns_fd = my_userns_fd;
+ }
+
+ if ((flags & DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY) == 0) {
+
+ /* First mount the root fs. If there's none we use a tmpfs. */
+ if (m->partitions[PARTITION_ROOT].found) {
+ r = mount_partition(PARTITION_ROOT, m->partitions + PARTITION_ROOT, where, NULL, uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+
+ } else if (where) {
+ r = mount_root_tmpfs(where, uid_shift, uid_range, flags);
+ if (r < 0)
+ return r;
+ }
+
+ /* For us mounting root always means mounting /usr as well */
+ r = mount_partition(PARTITION_USR, m->partitions + PARTITION_USR, where, "/usr", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+ }
+
+ if ((flags & DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY) == 0 &&
+ (flags & (DISSECT_IMAGE_VALIDATE_OS|DISSECT_IMAGE_VALIDATE_OS_EXT)) != 0) {
+ /* If either one of the validation flags are set, ensure that the image qualifies as
+ * one or the other (or both). */
+ bool ok = false;
+
+ assert(where);
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_VALIDATE_OS)) {
+ r = path_is_os_tree(where);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ ok = true;
+ }
+ if (!ok && FLAGS_SET(flags, DISSECT_IMAGE_VALIDATE_OS_EXT) && m->image_name) {
+ r = extension_has_forbidden_content(where);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ r = path_is_extension_tree(IMAGE_SYSEXT, where, m->image_name, FLAGS_SET(flags, DISSECT_IMAGE_RELAX_EXTENSION_CHECK));
+ if (r == 0)
+ r = path_is_extension_tree(IMAGE_CONFEXT, where, m->image_name, FLAGS_SET(flags, DISSECT_IMAGE_RELAX_EXTENSION_CHECK));
+ if (r < 0)
+ return r;
+ if (r > 0)
+ ok = true;
+ }
+ }
+
+ if (!ok)
+ return -ENOMEDIUM;
+ }
+
+ if (flags & DISSECT_IMAGE_MOUNT_ROOT_ONLY)
+ return 0;
+
+ r = mount_partition(PARTITION_HOME, m->partitions + PARTITION_HOME, where, "/home", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+
+ r = mount_partition(PARTITION_SRV, m->partitions + PARTITION_SRV, where, "/srv", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+
+ r = mount_partition(PARTITION_VAR, m->partitions + PARTITION_VAR, where, "/var", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+
+ r = mount_partition(PARTITION_TMP, m->partitions + PARTITION_TMP, where, "/var/tmp", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+
+ int slash_boot_is_available = 0;
+ if (where) {
+ r = slash_boot_is_available = mount_point_is_available(where, "/boot", /* missing_ok = */ true);
+ if (r < 0)
+ return r;
+ }
+ if (!where || slash_boot_is_available) {
+ r = mount_partition(PARTITION_XBOOTLDR, m->partitions + PARTITION_XBOOTLDR, where, "/boot", uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+ slash_boot_is_available = !r;
+ }
+
+ if (m->partitions[PARTITION_ESP].found) {
+ const char *esp_path = NULL;
+
+ if (where) {
+ /* Mount the ESP to /boot/ if it exists and is empty and we didn't already mount the
+ * XBOOTLDR partition into it. Otherwise, use /efi instead, but only if it exists
+ * and is empty. */
+
+ if (slash_boot_is_available) {
+ r = mount_point_is_available(where, "/boot", /* missing_ok = */ false);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ esp_path = "/boot";
+ }
+
+ if (!esp_path) {
+ r = mount_point_is_available(where, "/efi", /* missing_ok = */ true);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ esp_path = "/efi";
+ }
+ }
+
+ /* OK, let's mount the ESP now (possibly creating the dir if missing) */
+ r = mount_partition(PARTITION_ESP, m->partitions + PARTITION_ESP, where, esp_path, uid_shift, uid_range, userns_fd, flags);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+int dissected_image_mount_and_warn(
+ DissectedImage *m,
+ const char *where,
+ uid_t uid_shift,
+ uid_t uid_range,
+ int userns_fd,
+ DissectImageFlags flags) {
+
+ int r;
+
+ assert(m);
+
+ r = dissected_image_mount(m, where, uid_shift, uid_range, userns_fd, flags);
+ if (r == -ENXIO)
+ return log_error_errno(r, "Not root file system found in image.");
+ if (r == -EMEDIUMTYPE)
+ return log_error_errno(r, "No suitable os-release/extension-release file in image found.");
+ if (r == -EUNATCH)
+ return log_error_errno(r, "Encrypted file system discovered, but decryption not requested.");
+ if (r == -EUCLEAN)
+ return log_error_errno(r, "File system check on image failed.");
+ if (r == -EBUSY)
+ return log_error_errno(r, "File system already mounted elsewhere.");
+ if (r == -EAFNOSUPPORT)
+ return log_error_errno(r, "File system type not supported or not known.");
+ if (r == -EIDRM)
+ return log_error_errno(r, "File system is too uncommon, refused.");
+ if (r < 0)
+ return log_error_errno(r, "Failed to mount image: %m");
+
+ return r;
+}
+
+#if HAVE_LIBCRYPTSETUP
+struct DecryptedPartition {
+ struct crypt_device *device;
+ char *name;
+ bool relinquished;
+};
+#endif
+
+typedef struct DecryptedPartition DecryptedPartition;
+
+struct DecryptedImage {
+ unsigned n_ref;
+ DecryptedPartition *decrypted;
+ size_t n_decrypted;
+};
+
+static DecryptedImage* decrypted_image_free(DecryptedImage *d) {
+#if HAVE_LIBCRYPTSETUP
+ int r;
+
+ if (!d)
+ return NULL;
+
+ for (size_t i = 0; i < d->n_decrypted; i++) {
+ DecryptedPartition *p = d->decrypted + i;
+
+ if (p->device && p->name && !p->relinquished) {
+ _cleanup_free_ char *node = NULL;
+
+ node = path_join("/dev/mapper", p->name);
+ if (node) {
+ r = btrfs_forget_device(node);
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to forget btrfs device %s, ignoring: %m", node);
+ } else
+ log_oom_debug();
+
+ /* Let's deactivate lazily, as the dm volume may be already/still used by other processes. */
+ r = sym_crypt_deactivate_by_name(p->device, p->name, CRYPT_DEACTIVATE_DEFERRED);
+ if (r < 0)
+ log_debug_errno(r, "Failed to deactivate encrypted partition %s", p->name);
+ }
+
+ if (p->device)
+ sym_crypt_free(p->device);
+ free(p->name);
+ }
+
+ free(d->decrypted);
+ free(d);
+#endif
+ return NULL;
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(DecryptedImage, decrypted_image, decrypted_image_free);
+
+#if HAVE_LIBCRYPTSETUP
+static int decrypted_image_new(DecryptedImage **ret) {
+ _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL;
+
+ assert(ret);
+
+ d = new(DecryptedImage, 1);
+ if (!d)
+ return -ENOMEM;
+
+ *d = (DecryptedImage) {
+ .n_ref = 1,
+ };
+
+ *ret = TAKE_PTR(d);
+ return 0;
+}
+
+static int make_dm_name_and_node(const void *original_node, const char *suffix, char **ret_name, char **ret_node) {
+ _cleanup_free_ char *name = NULL, *node = NULL;
+ const char *base;
+
+ assert(original_node);
+ assert(suffix);
+ assert(ret_name);
+ assert(ret_node);
+
+ base = strrchr(original_node, '/');
+ if (!base)
+ base = original_node;
+ else
+ base++;
+ if (isempty(base))
+ return -EINVAL;
+
+ name = strjoin(base, suffix);
+ if (!name)
+ return -ENOMEM;
+ if (!filename_is_valid(name))
+ return -EINVAL;
+
+ node = path_join(sym_crypt_get_dir(), name);
+ if (!node)
+ return -ENOMEM;
+
+ *ret_name = TAKE_PTR(name);
+ *ret_node = TAKE_PTR(node);
+
+ return 0;
+}
+
+static int decrypt_partition(
+ DissectedPartition *m,
+ const char *passphrase,
+ DissectImageFlags flags,
+ DecryptedImage *d) {
+
+ _cleanup_free_ char *node = NULL, *name = NULL;
+ _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
+ _cleanup_close_ int fd = -EBADF;
+ int r;
+
+ assert(m);
+ assert(d);
+
+ if (!m->found || !m->node || !m->fstype)
+ return 0;
+
+ if (!streq(m->fstype, "crypto_LUKS"))
+ return 0;
+
+ if (!passphrase)
+ return -ENOKEY;
+
+ r = dlopen_cryptsetup();
+ if (r < 0)
+ return r;
+
+ r = make_dm_name_and_node(m->node, "-decrypted", &name, &node);
+ if (r < 0)
+ return r;
+
+ if (!GREEDY_REALLOC0(d->decrypted, d->n_decrypted + 1))
+ return -ENOMEM;
+
+ r = sym_crypt_init(&cd, m->node);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to initialize dm-crypt: %m");
+
+ cryptsetup_enable_logging(cd);
+
+ r = sym_crypt_load(cd, CRYPT_LUKS, NULL);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to load LUKS metadata: %m");
+
+ r = sym_crypt_activate_by_passphrase(cd, name, CRYPT_ANY_SLOT, passphrase, strlen(passphrase),
+ ((flags & DISSECT_IMAGE_DEVICE_READ_ONLY) ? CRYPT_ACTIVATE_READONLY : 0) |
+ ((flags & DISSECT_IMAGE_DISCARD_ON_CRYPTO) ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0));
+ if (r < 0) {
+ log_debug_errno(r, "Failed to activate LUKS device: %m");
+ return r == -EPERM ? -EKEYREJECTED : r;
+ }
+
+ fd = open(node, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return log_debug_errno(errno, "Failed to open %s: %m", node);
+
+ d->decrypted[d->n_decrypted++] = (DecryptedPartition) {
+ .name = TAKE_PTR(name),
+ .device = TAKE_PTR(cd),
+ };
+
+ m->decrypted_node = TAKE_PTR(node);
+ close_and_replace(m->mount_node_fd, fd);
+
+ return 0;
+}
+
+static int verity_can_reuse(
+ const VeritySettings *verity,
+ const char *name,
+ struct crypt_device **ret_cd) {
+
+ /* If the same volume was already open, check that the root hashes match, and reuse it if they do */
+ _cleanup_free_ char *root_hash_existing = NULL;
+ _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
+ struct crypt_params_verity crypt_params = {};
+ size_t root_hash_existing_size;
+ int r;
+
+ assert(verity);
+ assert(name);
+ assert(ret_cd);
+
+ r = sym_crypt_init_by_name(&cd, name);
+ if (r < 0)
+ return log_debug_errno(r, "Error opening verity device, crypt_init_by_name failed: %m");
+
+ cryptsetup_enable_logging(cd);
+
+ r = sym_crypt_get_verity_info(cd, &crypt_params);
+ if (r < 0)
+ return log_debug_errno(r, "Error opening verity device, crypt_get_verity_info failed: %m");
+
+ root_hash_existing_size = verity->root_hash_size;
+ root_hash_existing = malloc0(root_hash_existing_size);
+ if (!root_hash_existing)
+ return -ENOMEM;
+
+ r = sym_crypt_volume_key_get(cd, CRYPT_ANY_SLOT, root_hash_existing, &root_hash_existing_size, NULL, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Error opening verity device, crypt_volume_key_get failed: %m");
+ if (verity->root_hash_size != root_hash_existing_size ||
+ memcmp(root_hash_existing, verity->root_hash, verity->root_hash_size) != 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Error opening verity device, it already exists but root hashes are different.");
+
+#if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+ /* Ensure that, if signatures are supported, we only reuse the device if the previous mount used the
+ * same settings, so that a previous unsigned mount will not be reused if the user asks to use
+ * signing for the new one, and vice versa. */
+ if (!!verity->root_hash_sig != !!(crypt_params.flags & CRYPT_VERITY_ROOT_HASH_SIGNATURE))
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Error opening verity device, it already exists but signature settings are not the same.");
+#endif
+
+ *ret_cd = TAKE_PTR(cd);
+ return 0;
+}
+
+static char* dm_deferred_remove_clean(char *name) {
+ if (!name)
+ return NULL;
+
+ (void) sym_crypt_deactivate_by_name(NULL, name, CRYPT_DEACTIVATE_DEFERRED);
+ return mfree(name);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char *, dm_deferred_remove_clean);
+
+static int validate_signature_userspace(const VeritySettings *verity) {
+#if HAVE_OPENSSL
+ _cleanup_(sk_X509_free_allp) STACK_OF(X509) *sk = NULL;
+ _cleanup_strv_free_ char **certs = NULL;
+ _cleanup_(PKCS7_freep) PKCS7 *p7 = NULL;
+ _cleanup_free_ char *s = NULL;
+ _cleanup_(BIO_freep) BIO *bio = NULL; /* 'bio' must be freed first, 's' second, hence keep this order
+ * of declaration in place, please */
+ const unsigned char *d;
+ int r;
+
+ assert(verity);
+ assert(verity->root_hash);
+ assert(verity->root_hash_sig);
+
+ /* Because installing a signature certificate into the kernel chain is so messy, let's optionally do
+ * userspace validation. */
+
+ r = conf_files_list_nulstr(&certs, ".crt", NULL, CONF_FILES_REGULAR|CONF_FILES_FILTER_MASKED, CONF_PATHS_NULSTR("verity.d"));
+ if (r < 0)
+ return log_debug_errno(r, "Failed to enumerate certificates: %m");
+ if (strv_isempty(certs)) {
+ log_debug("No userspace dm-verity certificates found.");
+ return 0;
+ }
+
+ d = verity->root_hash_sig;
+ p7 = d2i_PKCS7(NULL, &d, (long) verity->root_hash_sig_size);
+ if (!p7)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to parse PKCS7 DER signature data.");
+
+ s = hexmem(verity->root_hash, verity->root_hash_size);
+ if (!s)
+ return log_oom_debug();
+
+ bio = BIO_new_mem_buf(s, strlen(s));
+ if (!bio)
+ return log_oom_debug();
+
+ sk = sk_X509_new_null();
+ if (!sk)
+ return log_oom_debug();
+
+ STRV_FOREACH(i, certs) {
+ _cleanup_(X509_freep) X509 *c = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+
+ f = fopen(*i, "re");
+ if (!f) {
+ log_debug_errno(errno, "Failed to open '%s', ignoring: %m", *i);
+ continue;
+ }
+
+ c = PEM_read_X509(f, NULL, NULL, NULL);
+ if (!c) {
+ log_debug("Failed to load X509 certificate '%s', ignoring.", *i);
+ continue;
+ }
+
+ if (sk_X509_push(sk, c) == 0)
+ return log_oom_debug();
+
+ TAKE_PTR(c);
+ }
+
+ r = PKCS7_verify(p7, sk, NULL, bio, NULL, PKCS7_NOINTERN|PKCS7_NOVERIFY);
+ if (r)
+ log_debug("Userspace PKCS#7 validation succeeded.");
+ else
+ log_debug("Userspace PKCS#7 validation failed: %s", ERR_error_string(ERR_get_error(), NULL));
+
+ return r;
+#else
+ log_debug("Not doing client-side validation of dm-verity root hash signatures, OpenSSL support disabled.");
+ return 0;
+#endif
+}
+
+static int do_crypt_activate_verity(
+ struct crypt_device *cd,
+ const char *name,
+ const VeritySettings *verity) {
+
+ bool check_signature;
+ int r, k;
+
+ assert(cd);
+ assert(name);
+ assert(verity);
+
+ if (verity->root_hash_sig) {
+ r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_SIGNATURE");
+ if (r < 0 && r != -ENXIO)
+ log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_SIGNATURE");
+
+ check_signature = r != 0;
+ } else
+ check_signature = false;
+
+ if (check_signature) {
+
+#if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY
+ /* First, if we have support for signed keys in the kernel, then try that first. */
+ r = sym_crypt_activate_by_signed_key(
+ cd,
+ name,
+ verity->root_hash,
+ verity->root_hash_size,
+ verity->root_hash_sig,
+ verity->root_hash_sig_size,
+ CRYPT_ACTIVATE_READONLY);
+ if (r >= 0)
+ return r;
+
+ log_debug_errno(r, "Validation of dm-verity signature failed via the kernel, trying userspace validation instead: %m");
+#else
+ 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.",
+ program_invocation_short_name);
+ r = 0; /* Set for the propagation below */
+#endif
+
+ /* So this didn't work via the kernel, then let's try userspace validation instead. If that
+ * works we'll try to activate without telling the kernel the signature. */
+
+ /* Preferably propagate the original kernel error, so that the fallback logic can work,
+ * as the device-mapper is finicky around concurrent activations of the same volume */
+ k = validate_signature_userspace(verity);
+ if (k < 0)
+ return r < 0 ? r : k;
+ if (k == 0)
+ return log_debug_errno(r < 0 ? r : SYNTHETIC_ERRNO(ENOKEY),
+ "Activation of signed Verity volume worked neither via the kernel nor in userspace, can't activate.");
+ }
+
+ return sym_crypt_activate_by_volume_key(
+ cd,
+ name,
+ verity->root_hash,
+ verity->root_hash_size,
+ CRYPT_ACTIVATE_READONLY);
+}
+
+static usec_t verity_timeout(void) {
+ usec_t t = 100 * USEC_PER_MSEC;
+ const char *e;
+ int r;
+
+ /* On slower machines, like non-KVM vm, setting up device may take a long time.
+ * Let's make the timeout configurable. */
+
+ e = getenv("SYSTEMD_DISSECT_VERITY_TIMEOUT_SEC");
+ if (!e)
+ return t;
+
+ r = parse_sec(e, &t);
+ if (r < 0)
+ log_debug_errno(r,
+ "Failed to parse timeout specified in $SYSTEMD_DISSECT_VERITY_TIMEOUT_SEC, "
+ "using the default timeout (%s).",
+ FORMAT_TIMESPAN(t, USEC_PER_MSEC));
+
+ return t;
+}
+
+static int verity_partition(
+ PartitionDesignator designator,
+ DissectedPartition *m,
+ DissectedPartition *v,
+ const VeritySettings *verity,
+ DissectImageFlags flags,
+ DecryptedImage *d) {
+
+ _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
+ _cleanup_free_ char *node = NULL, *name = NULL;
+ _cleanup_close_ int mount_node_fd = -EBADF;
+ int r;
+
+ assert(m);
+ assert(v || (verity && verity->data_path));
+
+ if (!verity || !verity->root_hash)
+ return 0;
+ if (!((verity->designator < 0 && designator == PARTITION_ROOT) ||
+ (verity->designator == designator)))
+ return 0;
+
+ if (!m->found || !m->node || !m->fstype)
+ return 0;
+ if (!verity->data_path) {
+ if (!v->found || !v->node || !v->fstype)
+ return 0;
+
+ if (!streq(v->fstype, "DM_verity_hash"))
+ return 0;
+ }
+
+ r = dlopen_cryptsetup();
+ if (r < 0)
+ return r;
+
+ if (FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE)) {
+ /* Use the roothash, which is unique per volume, as the device node name, so that it can be reused */
+ _cleanup_free_ char *root_hash_encoded = NULL;
+
+ root_hash_encoded = hexmem(verity->root_hash, verity->root_hash_size);
+ if (!root_hash_encoded)
+ return -ENOMEM;
+
+ r = make_dm_name_and_node(root_hash_encoded, "-verity", &name, &node);
+ } else
+ r = make_dm_name_and_node(m->node, "-verity", &name, &node);
+ if (r < 0)
+ return r;
+
+ r = sym_crypt_init(&cd, verity->data_path ?: v->node);
+ if (r < 0)
+ return r;
+
+ cryptsetup_enable_logging(cd);
+
+ r = sym_crypt_load(cd, CRYPT_VERITY, NULL);
+ if (r < 0)
+ return r;
+
+ r = sym_crypt_set_data_device(cd, m->node);
+ if (r < 0)
+ return r;
+
+ if (!GREEDY_REALLOC0(d->decrypted, d->n_decrypted + 1))
+ return -ENOMEM;
+
+ /* If activating fails because the device already exists, check the metadata and reuse it if it matches.
+ * In case of ENODEV/ENOENT, which can happen if another process is activating at the exact same time,
+ * retry a few times before giving up. */
+ for (unsigned i = 0; i < N_DEVICE_NODE_LIST_ATTEMPTS; i++) {
+ _cleanup_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL;
+ _cleanup_(sym_crypt_freep) struct crypt_device *existing_cd = NULL;
+ _cleanup_close_ int fd = -EBADF;
+
+ /* First, check if the device already exists. */
+ fd = open(node, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0 && !ERRNO_IS_DEVICE_ABSENT(errno))
+ return log_debug_errno(errno, "Failed to open verity device %s: %m", node);
+ if (fd >= 0)
+ goto check; /* The device already exists. Let's check it. */
+
+ /* The symlink to the device node does not exist yet. Assume not activated, and let's activate it. */
+ r = do_crypt_activate_verity(cd, name, verity);
+ if (r >= 0)
+ goto try_open; /* The device is activated. Let's open it. */
+ /* libdevmapper can return EINVAL when the device is already in the activation stage.
+ * There's no way to distinguish this situation from a genuine error due to invalid
+ * parameters, so immediately fall back to activating the device with a unique name.
+ * Improvements in libcrypsetup can ensure this never happens:
+ * https://gitlab.com/cryptsetup/cryptsetup/-/merge_requests/96 */
+ if (r == -EINVAL && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
+ break;
+ if (r == -ENODEV) /* Volume is being opened but not ready, crypt_init_by_name would fail, try to open again */
+ goto try_again;
+ if (!IN_SET(r,
+ -EEXIST, /* Volume has already been opened and ready to be used. */
+ -EBUSY /* Volume is being opened but not ready, crypt_init_by_name() can fetch details. */))
+ return log_debug_errno(r, "Failed to activate verity device %s: %m", node);
+
+ check:
+ /* To avoid races, disable automatic removal on umount while setting up the new device. Restore it on failure. */
+ r = dm_deferred_remove_cancel(name);
+ /* -EBUSY and -ENXIO: the device has already been removed or being removed. We cannot
+ * use the device, try to open again. See target_message() in drivers/md/dm-ioctl.c
+ * and dm_cancel_deferred_remove() in drivers/md/dm.c */
+ if (IN_SET(r, -EBUSY, -ENXIO))
+ goto try_again;
+ if (r < 0)
+ return log_debug_errno(r, "Failed to disable automated deferred removal for verity device %s: %m", node);
+
+ restore_deferred_remove = strdup(name);
+ if (!restore_deferred_remove)
+ return log_oom_debug();
+
+ r = verity_can_reuse(verity, name, &existing_cd);
+ /* Same as above, -EINVAL can randomly happen when it actually means -EEXIST */
+ if (r == -EINVAL && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
+ break;
+ if (IN_SET(r,
+ -ENOENT, /* Removed?? */
+ -EBUSY, /* Volume is being opened but not ready, crypt_init_by_name() can fetch details. */
+ -ENODEV /* Volume is being opened but not ready, crypt_init_by_name() would fail, try to open again. */ ))
+ goto try_again;
+ if (r < 0)
+ return log_debug_errno(r, "Failed to check if existing verity device %s can be reused: %m", node);
+
+ if (fd < 0) {
+ /* devmapper might say that the device exists, but the devlink might not yet have been
+ * created. Check and wait for the udev event in that case. */
+ r = device_wait_for_devlink(node, "block", verity_timeout(), NULL);
+ /* Fallback to activation with a unique device if it's taking too long */
+ if (r == -ETIMEDOUT && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE))
+ break;
+ if (r < 0)
+ return log_debug_errno(r, "Failed to wait device node symlink %s: %m", node);
+ }
+
+ try_open:
+ if (fd < 0) {
+ /* Now, the device is activated and devlink is created. Let's open it. */
+ fd = open(node, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0) {
+ if (!ERRNO_IS_DEVICE_ABSENT(errno))
+ return log_debug_errno(errno, "Failed to open verity device %s: %m", node);
+
+ /* The device has already been removed?? */
+ goto try_again;
+ }
+ }
+
+ /* Everything looks good and we'll be able to mount the device, so deferred remove will be re-enabled at that point. */
+ restore_deferred_remove = mfree(restore_deferred_remove);
+
+ mount_node_fd = TAKE_FD(fd);
+ if (existing_cd)
+ crypt_free_and_replace(cd, existing_cd);
+
+ goto success;
+
+ try_again:
+ /* Device is being removed by another process. Let's wait for a while. */
+ (void) usleep_safe(2 * USEC_PER_MSEC);
+ }
+
+ /* All trials failed or a conflicting verity device exists. Let's try to activate with a unique name. */
+ if (FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE)) {
+ /* Before trying to activate with unique name, we need to free crypt_device object.
+ * Otherwise, we get error from libcryptsetup like the following:
+ * ------
+ * systemd[1234]: Cannot use device /dev/loop5 which is in use (already mapped or mounted).
+ * ------
+ */
+ sym_crypt_free(cd);
+ cd = NULL;
+ return verity_partition(designator, m, v, verity, flags & ~DISSECT_IMAGE_VERITY_SHARE, d);
+ }
+
+ return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), "All attempts to activate verity device %s failed.", name);
+
+success:
+ d->decrypted[d->n_decrypted++] = (DecryptedPartition) {
+ .name = TAKE_PTR(name),
+ .device = TAKE_PTR(cd),
+ };
+
+ m->decrypted_node = TAKE_PTR(node);
+ close_and_replace(m->mount_node_fd, mount_node_fd);
+
+ return 0;
+}
+#endif
+
+int dissected_image_decrypt(
+ DissectedImage *m,
+ const char *passphrase,
+ const VeritySettings *verity,
+ DissectImageFlags flags) {
+
+#if HAVE_LIBCRYPTSETUP
+ _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL;
+ int r;
+#endif
+
+ assert(m);
+ assert(!verity || verity->root_hash || verity->root_hash_size == 0);
+
+ /* Returns:
+ *
+ * = 0 → There was nothing to decrypt
+ * > 0 → Decrypted successfully
+ * -ENOKEY → There's something to decrypt but no key was supplied
+ * -EKEYREJECTED → Passed key was not correct
+ */
+
+ if (verity && verity->root_hash && verity->root_hash_size < sizeof(sd_id128_t))
+ return -EINVAL;
+
+ if (!m->encrypted && !m->verity_ready)
+ return 0;
+
+#if HAVE_LIBCRYPTSETUP
+ r = decrypted_image_new(&d);
+ if (r < 0)
+ return r;
+
+ for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
+ DissectedPartition *p = m->partitions + i;
+ PartitionDesignator k;
+
+ if (!p->found)
+ continue;
+
+ r = decrypt_partition(p, passphrase, flags, d);
+ if (r < 0)
+ return r;
+
+ k = partition_verity_of(i);
+ if (k >= 0) {
+ r = verity_partition(i, p, m->partitions + k, verity, flags | DISSECT_IMAGE_VERITY_SHARE, d);
+ if (r < 0)
+ return r;
+ }
+
+ if (!p->decrypted_fstype && p->mount_node_fd >= 0 && p->decrypted_node) {
+ r = probe_filesystem_full(p->mount_node_fd, p->decrypted_node, 0, UINT64_MAX, &p->decrypted_fstype);
+ if (r < 0 && r != -EUCLEAN)
+ return r;
+ }
+ }
+
+ m->decrypted_image = TAKE_PTR(d);
+
+ return 1;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+int dissected_image_decrypt_interactively(
+ DissectedImage *m,
+ const char *passphrase,
+ const VeritySettings *verity,
+ DissectImageFlags flags) {
+
+ _cleanup_strv_free_erase_ char **z = NULL;
+ int n = 3, r;
+
+ if (passphrase)
+ n--;
+
+ for (;;) {
+ r = dissected_image_decrypt(m, passphrase, verity, flags);
+ if (r >= 0)
+ return r;
+ if (r == -EKEYREJECTED)
+ log_error_errno(r, "Incorrect passphrase, try again!");
+ else if (r != -ENOKEY)
+ return log_error_errno(r, "Failed to decrypt image: %m");
+
+ if (--n < 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EKEYREJECTED),
+ "Too many retries.");
+
+ z = strv_free(z);
+
+ r = ask_password_auto("Please enter image passphrase:", NULL, "dissect", "dissect", "dissect.passphrase", USEC_INFINITY, 0, &z);
+ if (r < 0)
+ return log_error_errno(r, "Failed to query for passphrase: %m");
+
+ passphrase = z[0];
+ }
+}
+
+static int decrypted_image_relinquish(DecryptedImage *d) {
+ assert(d);
+
+ /* Turns on automatic removal after the last use ended for all DM devices of this image, and sets a
+ * boolean so that we don't clean it up ourselves either anymore */
+
+#if HAVE_LIBCRYPTSETUP
+ int r;
+
+ for (size_t i = 0; i < d->n_decrypted; i++) {
+ DecryptedPartition *p = d->decrypted + i;
+
+ if (p->relinquished)
+ continue;
+
+ r = sym_crypt_deactivate_by_name(NULL, p->name, CRYPT_DEACTIVATE_DEFERRED);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to mark %s for auto-removal: %m", p->name);
+
+ p->relinquished = true;
+ }
+#endif
+
+ return 0;
+}
+
+int dissected_image_relinquish(DissectedImage *m) {
+ int r;
+
+ assert(m);
+
+ if (m->decrypted_image) {
+ r = decrypted_image_relinquish(m->decrypted_image);
+ if (r < 0)
+ return r;
+ }
+
+ if (m->loop)
+ loop_device_relinquish(m->loop);
+
+ return 0;
+}
+
+static char *build_auxiliary_path(const char *image, const char *suffix) {
+ const char *e;
+ char *n;
+
+ assert(image);
+ assert(suffix);
+
+ e = endswith(image, ".raw");
+ if (!e)
+ return strjoin(e, suffix);
+
+ n = new(char, e - image + strlen(suffix) + 1);
+ if (!n)
+ return NULL;
+
+ strcpy(mempcpy(n, image, e - image), suffix);
+ return n;
+}
+
+void verity_settings_done(VeritySettings *v) {
+ assert(v);
+
+ v->root_hash = mfree(v->root_hash);
+ v->root_hash_size = 0;
+
+ v->root_hash_sig = mfree(v->root_hash_sig);
+ v->root_hash_sig_size = 0;
+
+ v->data_path = mfree(v->data_path);
+}
+
+int verity_settings_load(
+ VeritySettings *verity,
+ const char *image,
+ const char *root_hash_path,
+ const char *root_hash_sig_path) {
+
+ _cleanup_free_ void *root_hash = NULL, *root_hash_sig = NULL;
+ size_t root_hash_size = 0, root_hash_sig_size = 0;
+ _cleanup_free_ char *verity_data_path = NULL;
+ PartitionDesignator designator;
+ int r;
+
+ assert(verity);
+ assert(image);
+ assert(verity->designator < 0 || IN_SET(verity->designator, PARTITION_ROOT, PARTITION_USR));
+
+ /* If we are asked to load the root hash for a device node, exit early */
+ if (is_device_path(image))
+ return 0;
+
+ r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_SIDECAR");
+ if (r < 0 && r != -ENXIO)
+ log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_SIDECAR, ignoring: %m");
+ if (r == 0)
+ return 0;
+
+ designator = verity->designator;
+
+ /* We only fill in what isn't already filled in */
+
+ if (!verity->root_hash) {
+ _cleanup_free_ char *text = NULL;
+
+ if (root_hash_path) {
+ /* If explicitly specified it takes precedence */
+ r = read_one_line_file(root_hash_path, &text);
+ if (r < 0)
+ return r;
+
+ if (designator < 0)
+ designator = PARTITION_ROOT;
+ } else {
+ /* Otherwise look for xattr and separate file, and first for the data for root and if
+ * that doesn't exist for /usr */
+
+ if (designator < 0 || designator == PARTITION_ROOT) {
+ r = getxattr_malloc(image, "user.verity.roothash", &text);
+ if (r < 0) {
+ _cleanup_free_ char *p = NULL;
+
+ if (r != -ENOENT && !ERRNO_IS_XATTR_ABSENT(r))
+ return r;
+
+ p = build_auxiliary_path(image, ".roothash");
+ if (!p)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &text);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ }
+
+ if (text)
+ designator = PARTITION_ROOT;
+ }
+
+ if (!text && (designator < 0 || designator == PARTITION_USR)) {
+ /* So in the "roothash" xattr/file name above the "root" of course primarily
+ * refers to the root of the Verity Merkle tree. But coincidentally it also
+ * is the hash for the *root* file system, i.e. the "root" neatly refers to
+ * two distinct concepts called "root". Taking benefit of this happy
+ * coincidence we call the file with the root hash for the /usr/ file system
+ * `usrhash`, because `usrroothash` or `rootusrhash` would just be too
+ * confusing. We thus drop the reference to the root of the Merkle tree, and
+ * just indicate which file system it's about. */
+ r = getxattr_malloc(image, "user.verity.usrhash", &text);
+ if (r < 0) {
+ _cleanup_free_ char *p = NULL;
+
+ if (r != -ENOENT && !ERRNO_IS_XATTR_ABSENT(r))
+ return r;
+
+ p = build_auxiliary_path(image, ".usrhash");
+ if (!p)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &text);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ }
+
+ if (text)
+ designator = PARTITION_USR;
+ }
+ }
+
+ if (text) {
+ r = unhexmem(text, strlen(text), &root_hash, &root_hash_size);
+ if (r < 0)
+ return r;
+ if (root_hash_size < sizeof(sd_id128_t))
+ return -EINVAL;
+ }
+ }
+
+ if ((root_hash || verity->root_hash) && !verity->root_hash_sig) {
+ if (root_hash_sig_path) {
+ r = read_full_file(root_hash_sig_path, (char**) &root_hash_sig, &root_hash_sig_size);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ if (designator < 0)
+ designator = PARTITION_ROOT;
+ } else {
+ if (designator < 0 || designator == PARTITION_ROOT) {
+ _cleanup_free_ char *p = NULL;
+
+ /* Follow naming convention recommended by the relevant RFC:
+ * https://tools.ietf.org/html/rfc5751#section-3.2.1 */
+ p = build_auxiliary_path(image, ".roothash.p7s");
+ if (!p)
+ return -ENOMEM;
+
+ r = read_full_file(p, (char**) &root_hash_sig, &root_hash_sig_size);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ if (r >= 0)
+ designator = PARTITION_ROOT;
+ }
+
+ if (!root_hash_sig && (designator < 0 || designator == PARTITION_USR)) {
+ _cleanup_free_ char *p = NULL;
+
+ p = build_auxiliary_path(image, ".usrhash.p7s");
+ if (!p)
+ return -ENOMEM;
+
+ r = read_full_file(p, (char**) &root_hash_sig, &root_hash_sig_size);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ if (r >= 0)
+ designator = PARTITION_USR;
+ }
+ }
+
+ if (root_hash_sig && root_hash_sig_size == 0) /* refuse empty size signatures */
+ return -EINVAL;
+ }
+
+ if (!verity->data_path) {
+ _cleanup_free_ char *p = NULL;
+
+ p = build_auxiliary_path(image, ".verity");
+ if (!p)
+ return -ENOMEM;
+
+ if (access(p, F_OK) < 0) {
+ if (errno != ENOENT)
+ return -errno;
+ } else
+ verity_data_path = TAKE_PTR(p);
+ }
+
+ if (root_hash) {
+ verity->root_hash = TAKE_PTR(root_hash);
+ verity->root_hash_size = root_hash_size;
+ }
+
+ if (root_hash_sig) {
+ verity->root_hash_sig = TAKE_PTR(root_hash_sig);
+ verity->root_hash_sig_size = root_hash_sig_size;
+ }
+
+ if (verity_data_path)
+ verity->data_path = TAKE_PTR(verity_data_path);
+
+ if (verity->designator < 0)
+ verity->designator = designator;
+
+ return 1;
+}
+
+int dissected_image_load_verity_sig_partition(
+ DissectedImage *m,
+ int fd,
+ VeritySettings *verity) {
+
+ _cleanup_free_ void *root_hash = NULL, *root_hash_sig = NULL;
+ _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+ size_t root_hash_size, root_hash_sig_size;
+ _cleanup_free_ char *buf = NULL;
+ PartitionDesignator d;
+ DissectedPartition *p;
+ JsonVariant *rh, *sig;
+ ssize_t n;
+ char *e;
+ int r;
+
+ assert(m);
+ assert(fd >= 0);
+ assert(verity);
+
+ if (verity->root_hash && verity->root_hash_sig) /* Already loaded? */
+ return 0;
+
+ r = getenv_bool_secure("SYSTEMD_DISSECT_VERITY_EMBEDDED");
+ if (r < 0 && r != -ENXIO)
+ log_debug_errno(r, "Failed to parse $SYSTEMD_DISSECT_VERITY_EMBEDDED, ignoring: %m");
+ if (r == 0)
+ return 0;
+
+ d = partition_verity_sig_of(verity->designator < 0 ? PARTITION_ROOT : verity->designator);
+ assert(d >= 0);
+
+ p = m->partitions + d;
+ if (!p->found)
+ return 0;
+ if (p->offset == UINT64_MAX || p->size == UINT64_MAX)
+ return -EINVAL;
+
+ if (p->size > 4*1024*1024) /* Signature data cannot possible be larger than 4M, refuse that */
+ return log_debug_errno(SYNTHETIC_ERRNO(EFBIG), "Verity signature partition is larger than 4M, refusing.");
+
+ buf = new(char, p->size+1);
+ if (!buf)
+ return -ENOMEM;
+
+ n = pread(fd, buf, p->size, p->offset);
+ if (n < 0)
+ return -ENOMEM;
+ if ((uint64_t) n != p->size)
+ return -EIO;
+
+ e = memchr(buf, 0, p->size);
+ if (e) {
+ /* If we found a NUL byte then the rest of the data must be NUL too */
+ if (!memeqzero(e, p->size - (e - buf)))
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature data contains embedded NUL byte.");
+ } else
+ buf[p->size] = 0;
+
+ r = json_parse(buf, 0, &v, NULL, NULL);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to parse signature JSON data: %m");
+
+ rh = json_variant_by_key(v, "rootHash");
+ if (!rh)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature JSON object lacks 'rootHash' field.");
+ if (!json_variant_is_string(rh))
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "'rootHash' field of signature JSON object is not a string.");
+
+ r = unhexmem(json_variant_string(rh), SIZE_MAX, &root_hash, &root_hash_size);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to parse root hash field: %m");
+
+ /* Check if specified root hash matches if it is specified */
+ if (verity->root_hash &&
+ memcmp_nn(verity->root_hash, verity->root_hash_size, root_hash, root_hash_size) != 0) {
+ _cleanup_free_ char *a = NULL, *b = NULL;
+
+ a = hexmem(root_hash, root_hash_size);
+ b = hexmem(verity->root_hash, verity->root_hash_size);
+
+ return log_debug_errno(r, "Root hash in signature JSON data (%s) doesn't match configured hash (%s).", strna(a), strna(b));
+ }
+
+ sig = json_variant_by_key(v, "signature");
+ if (!sig)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature JSON object lacks 'signature' field.");
+ if (!json_variant_is_string(sig))
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "'signature' field of signature JSON object is not a string.");
+
+ r = unbase64mem(json_variant_string(sig), SIZE_MAX, &root_hash_sig, &root_hash_sig_size);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to parse signature field: %m");
+
+ free_and_replace(verity->root_hash, root_hash);
+ verity->root_hash_size = root_hash_size;
+
+ free_and_replace(verity->root_hash_sig, root_hash_sig);
+ verity->root_hash_sig_size = root_hash_sig_size;
+
+ return 1;
+}
+
+int dissected_image_acquire_metadata(DissectedImage *m, DissectImageFlags extra_flags) {
+
+ enum {
+ META_HOSTNAME,
+ META_MACHINE_ID,
+ META_MACHINE_INFO,
+ META_OS_RELEASE,
+ META_INITRD_RELEASE,
+ META_SYSEXT_RELEASE,
+ META_CONFEXT_RELEASE,
+ META_HAS_INIT_SYSTEM,
+ _META_MAX,
+ };
+
+ static const char *const paths[_META_MAX] = {
+ [META_HOSTNAME] = "/etc/hostname\0",
+ [META_MACHINE_ID] = "/etc/machine-id\0",
+ [META_MACHINE_INFO] = "/etc/machine-info\0",
+ [META_OS_RELEASE] = "/etc/os-release\0"
+ "/usr/lib/os-release\0",
+ [META_INITRD_RELEASE] = "/etc/initrd-release\0"
+ "/usr/lib/initrd-release\0",
+ [META_SYSEXT_RELEASE] = "sysext-release\0", /* String used only for logging. */
+ [META_CONFEXT_RELEASE] = "confext-release\0", /* ditto */
+ [META_HAS_INIT_SYSTEM] = "has-init-system\0", /* ditto */
+ };
+
+ _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL, **initrd_release = NULL, **sysext_release = NULL, **confext_release = NULL;
+ _cleanup_close_pair_ int error_pipe[2] = EBADF_PAIR;
+ _cleanup_(rmdir_and_freep) char *t = NULL;
+ _cleanup_(sigkill_waitp) pid_t child = 0;
+ sd_id128_t machine_id = SD_ID128_NULL;
+ _cleanup_free_ char *hostname = NULL;
+ unsigned n_meta_initialized = 0;
+ int fds[2 * _META_MAX], r, v;
+ int has_init_system = -1;
+ ssize_t n;
+
+ BLOCK_SIGNALS(SIGCHLD);
+
+ assert(m);
+
+ for (; n_meta_initialized < _META_MAX; n_meta_initialized ++) {
+ if (!paths[n_meta_initialized]) {
+ fds[2*n_meta_initialized] = fds[2*n_meta_initialized+1] = -EBADF;
+ continue;
+ }
+
+ if (pipe2(fds + 2*n_meta_initialized, O_CLOEXEC) < 0) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ r = mkdtemp_malloc("/tmp/dissect-XXXXXX", &t);
+ if (r < 0)
+ goto finish;
+
+ if (pipe2(error_pipe, O_CLOEXEC) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ r = safe_fork("(sd-dissect)", FORK_RESET_SIGNALS|FORK_DEATHSIG_SIGTERM|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, &child);
+ if (r < 0)
+ goto finish;
+ if (r == 0) {
+ /* Child in a new mount namespace */
+ error_pipe[0] = safe_close(error_pipe[0]);
+
+ r = dissected_image_mount(
+ m,
+ t,
+ /* uid_shift= */ UID_INVALID,
+ /* uid_range= */ UID_INVALID,
+ /* userns_fd= */ -EBADF,
+ extra_flags |
+ DISSECT_IMAGE_READ_ONLY |
+ DISSECT_IMAGE_MOUNT_ROOT_ONLY |
+ DISSECT_IMAGE_USR_NO_ROOT);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to mount dissected image: %m");
+ goto inner_fail;
+ }
+
+ for (unsigned k = 0; k < _META_MAX; k++) {
+ _cleanup_close_ int fd = -ENOENT;
+
+ if (!paths[k])
+ continue;
+
+ fds[2*k] = safe_close(fds[2*k]);
+
+ switch (k) {
+
+ case META_SYSEXT_RELEASE:
+ if (!m->image_name)
+ goto next;
+
+ /* As per the os-release spec, if the image is an extension it will have a
+ * file named after the image name in extension-release.d/ - we use the image
+ * name and try to resolve it with the extension-release helpers, as
+ * sometimes the image names are mangled on deployment and do not match
+ * anymore. Unlike other paths this is not fixed, and the image name can be
+ * mangled on deployment, so by calling into the helper we allow a fallback
+ * that matches on the first extension-release file found in the directory,
+ * if one named after the image cannot be found first. */
+ r = open_extension_release(
+ t,
+ IMAGE_SYSEXT,
+ m->image_name,
+ /* relax_extension_release_check= */ false,
+ /* ret_path= */ NULL,
+ &fd);
+ if (r < 0)
+ fd = r;
+ break;
+
+ case META_CONFEXT_RELEASE:
+ if (!m->image_name)
+ goto next;
+
+ /* As above */
+ r = open_extension_release(
+ t,
+ IMAGE_CONFEXT,
+ m->image_name,
+ /* relax_extension_release_check= */ false,
+ /* ret_path= */ NULL,
+ &fd);
+ if (r < 0)
+ fd = r;
+
+ break;
+
+ case META_HAS_INIT_SYSTEM: {
+ bool found = false;
+
+ FOREACH_STRING(init,
+ "/usr/lib/systemd/systemd", /* systemd on /usr/ merged system */
+ "/lib/systemd/systemd", /* systemd on /usr/ non-merged systems */
+ "/sbin/init") { /* traditional path the Linux kernel invokes */
+
+ r = chase(init, t, CHASE_PREFIX_ROOT, NULL, NULL);
+ if (r < 0) {
+ if (r != -ENOENT)
+ log_debug_errno(r, "Failed to resolve %s, ignoring: %m", init);
+ } else {
+ found = true;
+ break;
+ }
+ }
+
+ r = loop_write(fds[2*k+1], &found, sizeof(found));
+ if (r < 0)
+ goto inner_fail;
+
+ goto next;
+ }
+
+ default:
+ NULSTR_FOREACH(p, paths[k]) {
+ fd = chase_and_open(p, t, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_NOCTTY, NULL);
+ if (fd >= 0)
+ break;
+ }
+ }
+
+ if (fd < 0) {
+ log_debug_errno(fd, "Failed to read %s file of image, ignoring: %m", paths[k]);
+ goto next;
+ }
+
+ r = copy_bytes(fd, fds[2*k+1], UINT64_MAX, 0);
+ if (r < 0)
+ goto inner_fail;
+
+ next:
+ fds[2*k+1] = safe_close(fds[2*k+1]);
+ }
+
+ _exit(EXIT_SUCCESS);
+
+ inner_fail:
+ /* Let parent know the error */
+ (void) write(error_pipe[1], &r, sizeof(r));
+ _exit(EXIT_FAILURE);
+ }
+
+ error_pipe[1] = safe_close(error_pipe[1]);
+
+ for (unsigned k = 0; k < _META_MAX; k++) {
+ _cleanup_fclose_ FILE *f = NULL;
+
+ if (!paths[k])
+ continue;
+
+ fds[2*k+1] = safe_close(fds[2*k+1]);
+
+ f = take_fdopen(&fds[2*k], "r");
+ if (!f) {
+ r = -errno;
+ goto finish;
+ }
+
+ switch (k) {
+
+ case META_HOSTNAME:
+ r = read_etc_hostname_stream(f, &hostname);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read /etc/hostname of image: %m");
+
+ break;
+
+ case META_MACHINE_ID: {
+ _cleanup_free_ char *line = NULL;
+
+ r = read_line(f, LONG_LINE_MAX, &line);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read /etc/machine-id of image: %m");
+ else if (r == 33) {
+ r = sd_id128_from_string(line, &machine_id);
+ if (r < 0)
+ log_debug_errno(r, "Image contains invalid /etc/machine-id: %s", line);
+ } else if (r == 0)
+ log_debug("/etc/machine-id file of image is empty.");
+ else if (streq(line, "uninitialized"))
+ log_debug("/etc/machine-id file of image is uninitialized (likely aborted first boot).");
+ else
+ log_debug("/etc/machine-id file of image has unexpected length %i.", r);
+
+ break;
+ }
+
+ case META_MACHINE_INFO:
+ r = load_env_file_pairs(f, "machine-info", &machine_info);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read /etc/machine-info of image: %m");
+
+ break;
+
+ case META_OS_RELEASE:
+ r = load_env_file_pairs(f, "os-release", &os_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read OS release file of image: %m");
+
+ break;
+
+ case META_INITRD_RELEASE:
+ r = load_env_file_pairs(f, "initrd-release", &initrd_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read initrd release file of image: %m");
+
+ break;
+
+ case META_SYSEXT_RELEASE:
+ r = load_env_file_pairs(f, "sysext-release", &sysext_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read sysext release file of image: %m");
+
+ break;
+
+ case META_CONFEXT_RELEASE:
+ r = load_env_file_pairs(f, "confext-release", &confext_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read confext release file of image: %m");
+
+ break;
+
+ case META_HAS_INIT_SYSTEM: {
+ bool b = false;
+ size_t nr;
+
+ errno = 0;
+ nr = fread(&b, 1, sizeof(b), f);
+ if (nr != sizeof(b))
+ log_debug_errno(errno_or_else(EIO), "Failed to read has-init-system boolean: %m");
+ else
+ has_init_system = b;
+
+ break;
+ }}
+ }
+
+ r = wait_for_terminate_and_check("(sd-dissect)", child, 0);
+ child = 0;
+ if (r < 0)
+ goto finish;
+
+ n = read(error_pipe[0], &v, sizeof(v));
+ if (n < 0) {
+ r = -errno;
+ goto finish;
+ }
+ if (n == sizeof(v)) {
+ r = v; /* propagate error sent to us from child */
+ goto finish;
+ }
+ if (n != 0) {
+ r = -EIO;
+ goto finish;
+ }
+ if (r != EXIT_SUCCESS) {
+ r = -EPROTO;
+ goto finish;
+ }
+
+ free_and_replace(m->hostname, hostname);
+ m->machine_id = machine_id;
+ strv_free_and_replace(m->machine_info, machine_info);
+ strv_free_and_replace(m->os_release, os_release);
+ strv_free_and_replace(m->initrd_release, initrd_release);
+ strv_free_and_replace(m->sysext_release, sysext_release);
+ strv_free_and_replace(m->confext_release, confext_release);
+ m->has_init_system = has_init_system;
+
+finish:
+ for (unsigned k = 0; k < n_meta_initialized; k++)
+ safe_close_pair(fds + 2*k);
+
+ return r;
+}
+
+Architecture dissected_image_architecture(DissectedImage *img) {
+ assert(img);
+
+ if (img->partitions[PARTITION_ROOT].found &&
+ img->partitions[PARTITION_ROOT].architecture >= 0)
+ return img->partitions[PARTITION_ROOT].architecture;
+
+ if (img->partitions[PARTITION_USR].found &&
+ img->partitions[PARTITION_USR].architecture >= 0)
+ return img->partitions[PARTITION_USR].architecture;
+
+ return _ARCHITECTURE_INVALID;
+}
+
+int dissect_loop_device(
+ LoopDevice *loop,
+ const VeritySettings *verity,
+ const MountOptions *mount_options,
+ const ImagePolicy *image_policy,
+ DissectImageFlags flags,
+ DissectedImage **ret) {
+
+#if HAVE_BLKID
+ _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+ int r;
+
+ assert(loop);
+
+ r = dissected_image_new(loop->backing_file ?: loop->node, &m);
+ if (r < 0)
+ return r;
+
+ m->loop = loop_device_ref(loop);
+ m->sector_size = m->loop->sector_size;
+
+ r = dissect_image(m, loop->fd, loop->node, verity, mount_options, image_policy, flags);
+ if (r < 0)
+ return r;
+
+ if (ret)
+ *ret = TAKE_PTR(m);
+
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+int dissect_loop_device_and_warn(
+ LoopDevice *loop,
+ const VeritySettings *verity,
+ const MountOptions *mount_options,
+ const ImagePolicy *image_policy,
+ DissectImageFlags flags,
+ DissectedImage **ret) {
+
+ assert(loop);
+
+ return dissect_log_error(
+ LOG_ERR,
+ dissect_loop_device(loop, verity, mount_options, image_policy, flags, ret),
+ loop->backing_file ?: loop->node,
+ verity);
+
+}
+
+bool dissected_image_verity_candidate(const DissectedImage *image, PartitionDesignator partition_designator) {
+ assert(image);
+
+ /* Checks if this partition could theoretically do Verity. For non-partitioned images this only works
+ * if there's an external verity file supplied, for which we can consult .has_verity. For partitioned
+ * images we only check the partition type.
+ *
+ * This call is used to decide whether to suppress or show a verity column in tabular output of the
+ * image. */
+
+ if (image->single_file_system)
+ return partition_designator == PARTITION_ROOT && image->has_verity;
+
+ return partition_verity_of(partition_designator) >= 0;
+}
+
+bool dissected_image_verity_ready(const DissectedImage *image, PartitionDesignator partition_designator) {
+ PartitionDesignator k;
+
+ assert(image);
+
+ /* Checks if this partition has verity data available that we can activate. For non-partitioned this
+ * works for the root partition, for others only if the associated verity partition was found. */
+
+ if (!image->verity_ready)
+ return false;
+
+ if (image->single_file_system)
+ return partition_designator == PARTITION_ROOT;
+
+ k = partition_verity_of(partition_designator);
+ return k >= 0 && image->partitions[k].found;
+}
+
+bool dissected_image_verity_sig_ready(const DissectedImage *image, PartitionDesignator partition_designator) {
+ PartitionDesignator k;
+
+ assert(image);
+
+ /* Checks if this partition has verity signature data available that we can use. */
+
+ if (!image->verity_sig_ready)
+ return false;
+
+ if (image->single_file_system)
+ return partition_designator == PARTITION_ROOT;
+
+ k = partition_verity_sig_of(partition_designator);
+ return k >= 0 && image->partitions[k].found;
+}
+
+MountOptions* mount_options_free_all(MountOptions *options) {
+ MountOptions *m;
+
+ while ((m = LIST_POP(mount_options, options))) {
+ free(m->options);
+ free(m);
+ }
+
+ return NULL;
+}
+
+const char* mount_options_from_designator(const MountOptions *options, PartitionDesignator designator) {
+ LIST_FOREACH(mount_options, m, options)
+ if (designator == m->partition_designator && !isempty(m->options))
+ return m->options;
+
+ return NULL;
+}
+
+int mount_image_privately_interactively(
+ const char *image,
+ const ImagePolicy *image_policy,
+ DissectImageFlags flags,
+ char **ret_directory,
+ int *ret_dir_fd,
+ LoopDevice **ret_loop_device) {
+
+ _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT;
+ _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
+ _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
+ _cleanup_free_ char *dir = NULL;
+ int r;
+
+ /* Mounts an OS image at a temporary place, inside a newly created mount namespace of our own. This
+ * is used by tools such as systemd-tmpfiles or systemd-firstboot to operate on some disk image
+ * easily. */
+
+ assert(image);
+ assert(ret_loop_device);
+
+ /* We intend to mount this right-away, hence add the partitions if needed and pin them. */
+ flags |= DISSECT_IMAGE_ADD_PARTITION_DEVICES |
+ DISSECT_IMAGE_PIN_PARTITION_DEVICES;
+
+ r = verity_settings_load(&verity, image, NULL, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to load root hash data: %m");
+
+ r = loop_device_make_by_path(
+ image,
+ FLAGS_SET(flags, DISSECT_IMAGE_DEVICE_READ_ONLY) ? O_RDONLY : O_RDWR,
+ /* sector_size= */ UINT32_MAX,
+ FLAGS_SET(flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN,
+ LOCK_SH,
+ &d);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set up loopback device for %s: %m", image);
+
+ r = dissect_loop_device_and_warn(
+ d,
+ &verity,
+ /* mount_options= */ NULL,
+ image_policy,
+ flags,
+ &dissected_image);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_load_verity_sig_partition(dissected_image, d->fd, &verity);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_decrypt_interactively(dissected_image, NULL, &verity, flags);
+ if (r < 0)
+ return r;
+
+ r = detach_mount_namespace();
+ if (r < 0)
+ return log_error_errno(r, "Failed to detach mount namespace: %m");
+
+ r = mkdir_p("/run/systemd/mount-rootfs", 0555);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create mount point: %m");
+
+ r = dissected_image_mount_and_warn(
+ dissected_image,
+ "/run/systemd/mount-rootfs",
+ /* uid_shift= */ UID_INVALID,
+ /* uid_range= */ UID_INVALID,
+ /* userns_fd= */ -EBADF,
+ flags);
+ if (r < 0)
+ return r;
+
+ r = loop_device_flock(d, LOCK_UN);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_relinquish(dissected_image);
+ if (r < 0)
+ return log_error_errno(r, "Failed to relinquish DM and loopback block devices: %m");
+
+ if (ret_directory) {
+ dir = strdup("/run/systemd/mount-rootfs");
+ if (!dir)
+ return log_oom();
+ }
+
+ if (ret_dir_fd) {
+ _cleanup_close_ int dir_fd = -EBADF;
+
+ dir_fd = open("/run/systemd/mount-rootfs", O_CLOEXEC|O_DIRECTORY);
+ if (dir_fd < 0)
+ return log_error_errno(errno, "Failed to open mount point directory: %m");
+
+ *ret_dir_fd = TAKE_FD(dir_fd);
+ }
+
+ if (ret_directory)
+ *ret_directory = TAKE_PTR(dir);
+
+ *ret_loop_device = TAKE_PTR(d);
+ return 0;
+}
+
+static bool mount_options_relax_extension_release_checks(const MountOptions *options) {
+ if (!options)
+ return false;
+
+ return string_contains_word(mount_options_from_designator(options, PARTITION_ROOT), ",", "x-systemd.relax-extension-release-check") ||
+ string_contains_word(mount_options_from_designator(options, PARTITION_USR), ",", "x-systemd.relax-extension-release-check") ||
+ string_contains_word(options->options, ",", "x-systemd.relax-extension-release-check");
+}
+
+int verity_dissect_and_mount(
+ int src_fd,
+ const char *src,
+ const char *dest,
+ const MountOptions *options,
+ const ImagePolicy *image_policy,
+ const char *required_host_os_release_id,
+ const char *required_host_os_release_version_id,
+ const char *required_host_os_release_sysext_level,
+ const char *required_host_os_release_confext_level,
+ const char *required_sysext_scope,
+ DissectedImage **ret_image) {
+
+ _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL;
+ _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
+ _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT;
+ DissectImageFlags dissect_image_flags;
+ bool relax_extension_release_check;
+ int r;
+
+ assert(src);
+ /* Verifying release metadata requires mounted image for now, so ensure the check is skipped when
+ * opening an image without mounting it immediately (i.e.: 'dest' is NULL). */
+ assert(!required_host_os_release_id || dest);
+
+ relax_extension_release_check = mount_options_relax_extension_release_checks(options);
+
+ /* We might get an FD for the image, but we use the original path to look for the dm-verity files */
+ r = verity_settings_load(&verity, src, NULL, NULL);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to load root hash: %m");
+
+ dissect_image_flags = (verity.data_path ? DISSECT_IMAGE_NO_PARTITION_TABLE : 0) |
+ (relax_extension_release_check ? DISSECT_IMAGE_RELAX_EXTENSION_CHECK : 0) |
+ DISSECT_IMAGE_ADD_PARTITION_DEVICES |
+ DISSECT_IMAGE_PIN_PARTITION_DEVICES;
+
+ /* Note that we don't use loop_device_make here, as the FD is most likely O_PATH which would not be
+ * accepted by LOOP_CONFIGURE, so just let loop_device_make_by_path reopen it as a regular FD. */
+ r = loop_device_make_by_path(
+ src_fd >= 0 ? FORMAT_PROC_FD_PATH(src_fd) : src,
+ /* open_flags= */ -1,
+ /* sector_size= */ UINT32_MAX,
+ verity.data_path ? 0 : LO_FLAGS_PARTSCAN,
+ LOCK_SH,
+ &loop_device);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to create loop device for image: %m");
+
+ r = dissect_loop_device(
+ loop_device,
+ &verity,
+ options,
+ image_policy,
+ dissect_image_flags,
+ &dissected_image);
+ /* No partition table? Might be a single-filesystem image, try again */
+ if (!verity.data_path && r == -ENOPKG)
+ r = dissect_loop_device(
+ loop_device,
+ &verity,
+ options,
+ image_policy,
+ dissect_image_flags | DISSECT_IMAGE_NO_PARTITION_TABLE,
+ &dissected_image);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to dissect image: %m");
+
+ r = dissected_image_load_verity_sig_partition(dissected_image, loop_device->fd, &verity);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_decrypt(
+ dissected_image,
+ NULL,
+ &verity,
+ dissect_image_flags);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to decrypt dissected image: %m");
+
+ if (dest) {
+ r = mkdir_p_label(dest, 0755);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to create destination directory %s: %m", dest);
+ r = umount_recursive(dest, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to umount under destination directory %s: %m", dest);
+ }
+
+ r = dissected_image_mount(
+ dissected_image,
+ dest,
+ /* uid_shift= */ UID_INVALID,
+ /* uid_range= */ UID_INVALID,
+ /* userns_fd= */ -EBADF,
+ dissect_image_flags);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to mount image: %m");
+
+ r = loop_device_flock(loop_device, LOCK_UN);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to unlock loopback device: %m");
+
+ /* If we got os-release values from the caller, then we need to match them with the image's
+ * extension-release.d/ content. Return -EINVAL if there's any mismatch.
+ * First, check the distro ID. If that matches, then check the new SYSEXT_LEVEL value if
+ * available, or else fallback to VERSION_ID. If neither is present (eg: rolling release),
+ * then a simple match on the ID will be performed. */
+ if (required_host_os_release_id) {
+ _cleanup_strv_free_ char **extension_release = NULL;
+ ImageClass class = IMAGE_SYSEXT;
+
+ assert(!isempty(required_host_os_release_id));
+
+ r = load_extension_release_pairs(dest, IMAGE_SYSEXT, dissected_image->image_name, relax_extension_release_check, &extension_release);
+ if (r == -ENOENT) {
+ r = load_extension_release_pairs(dest, IMAGE_CONFEXT, dissected_image->image_name, relax_extension_release_check, &extension_release);
+ if (r >= 0)
+ class = IMAGE_CONFEXT;
+ }
+ if (r < 0)
+ return log_debug_errno(r, "Failed to parse image %s extension-release metadata: %m", dissected_image->image_name);
+
+ r = extension_release_validate(
+ dissected_image->image_name,
+ required_host_os_release_id,
+ required_host_os_release_version_id,
+ class == IMAGE_SYSEXT ? required_host_os_release_sysext_level : required_host_os_release_confext_level,
+ required_sysext_scope,
+ extension_release,
+ class);
+ if (r == 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(ESTALE), "Image %s extension-release metadata does not match the root's", dissected_image->image_name);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to compare image %s extension-release metadata with the root's os-release: %m", dissected_image->image_name);
+ }
+
+ r = dissected_image_relinquish(dissected_image);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to relinquish dissected image: %m");
+
+ if (ret_image)
+ *ret_image = TAKE_PTR(dissected_image);
+
+ return 0;
+}