diff options
Diffstat (limited to 'src/shared/dissect-image.c')
| -rw-r--r-- | src/shared/dissect-image.c | 3477 |
1 files changed, 3477 insertions, 0 deletions
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c new file mode 100644 index 0000000..d2446de --- /dev/null +++ b/src/shared/dissect-image.c @@ -0,0 +1,3477 @@ +/* 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 "chase-symlinks.h" +#include "conf-files.h" +#include "copy.h" +#include "cryptsetup-util.h" +#include "def.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-release.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 "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 "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 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 = -1; + 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 == 1) + goto not_found; + if (r == -2) + return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), + "Results ambiguous for partition %s", path); + if (r != 0) + return log_debug_errno(errno_or_else(EIO), "Failed to probe partition %s: %m", path); + + (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 dissected_image_probe_filesystems(DissectedImage *m, int fd) { + 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; + + 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; + + if (p->fstype && fstype_is_ro(p->fstype)) + p->rw = false; + + if (!p->rw) + p->growfs = false; + } + + 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); + } +} +#endif + +#if HAVE_BLKID +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); + + *p = DISSECTED_PARTITION_NULL; +} + +#if HAVE_BLKID +static int make_partition_devname( + const char *whole_devname, + int nr, + char **ret) { + + bool need_p; + + assert(whole_devname); + assert(nr > 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 (isempty(whole_devname)) /* Make sure there *is* a last char */ + return -EINVAL; + + need_p = ascii_isdigit(whole_devname[strlen(whole_devname)-1]); /* Last char a digit? */ + + return asprintf(ret, "%s%s%i", whole_devname, need_p ? "p" : "", nr); +} + +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 = -1; + 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 dissect_image( + DissectedImage *m, + int fd, + const char *devname, + const VeritySettings *verity, + const MountOptions *mount_options, + 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; + 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))); + + /* 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 */ + + 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 128bit of the root hash. And we use the verity partition that has a UUID that match + * the final 128bit. */ + + 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); + + 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_probe_enable_partitions(b, 1); + blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); + + errno = 0; + r = blkid_do_safeprobe(b); + if (IN_SET(r, -2, 1)) + return log_debug_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to identify any partition table."); + if (r != 0) + return errno_or_else(EIO); + + 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; + _cleanup_close_ int mount_node_fd = -1; + + 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; + } + + /* OK, we have found a file system, that's our root partition then. */ + (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); + + if (fstype) { + t = strdup(fstype); + if (!t) + return -ENOMEM; + } + + n = strdup(devname); + if (!n) + return -ENOMEM; + + m->single_file_system = true; + m->encrypted = streq_ptr(fstype, "crypto_LUKS"); + + m->has_verity = verity && verity->data_path; + m->verity_ready = m->has_verity && + verity->root_hash && + (verity->designator < 0 || verity->designator == PARTITION_ROOT); + + m->has_verity_sig = false; /* signature not embedded, must be specified */ + m->verity_sig_ready = m->verity_ready && + verity->root_hash_sig; + + 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, + }; + + 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; + } + + 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); + + r = make_partition_devname(devname, nr, &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) { + PartitionDesignator designator = _PARTITION_DESIGNATOR_INVALID; + Architecture architecture = _ARCHITECTURE_INVALID; + const char *stype, *sid, *fstype = NULL, *label; + sd_id128_t type_id, id; + bool rw = true, growfs = false; + + sid = blkid_partition_get_uuid(pp); + if (!sid) + continue; + if (sd_id128_from_string(sid, &id) < 0) + continue; + + stype = blkid_partition_get_type_string(pp); + if (!stype) + continue; + if (sd_id128_from_string(stype, &type_id) < 0) + continue; + + label = blkid_partition_get_name(pp); /* libblkid returns NULL here if empty */ + + if (sd_id128_equal(type_id, SD_GPT_HOME)) { + + 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; + + designator = PARTITION_HOME; + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (sd_id128_equal(type_id, SD_GPT_SRV)) { + + 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; + + designator = PARTITION_SRV; + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (sd_id128_equal(type_id, SD_GPT_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; + + designator = PARTITION_ESP; + fstype = "vfat"; + + } else if (sd_id128_equal(type_id, SD_GPT_XBOOTLDR)) { + + 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; + + designator = PARTITION_XBOOTLDR; + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (gpt_partition_type_is_root(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_ROOT_OF_ARCH(architecture); + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (gpt_partition_type_is_root_verity(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_VERITY_OF(PARTITION_ROOT_OF_ARCH(architecture)); + fstype = "DM_verity_hash"; + rw = false; + + } else if (gpt_partition_type_is_root_verity_sig(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_VERITY_SIG_OF(PARTITION_ROOT_OF_ARCH(architecture)); + fstype = "verity_hash_signature"; + rw = false; + + } else if (gpt_partition_type_is_usr(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_USR_OF_ARCH(architecture); + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (gpt_partition_type_is_usr_verity(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_VERITY_OF(PARTITION_USR_OF_ARCH(architecture)); + fstype = "DM_verity_hash"; + rw = false; + + } else if (gpt_partition_type_is_usr_verity_sig(type_id)) { + + 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; + + assert_se((architecture = gpt_partition_type_uuid_to_arch(type_id)) >= 0); + designator = PARTITION_VERITY_SIG_OF(PARTITION_USR_OF_ARCH(architecture)); + fstype = "verity_hash_signature"; + rw = false; + + } else if (sd_id128_equal(type_id, SD_GPT_SWAP)) { + + check_partition_flags(node, pflags, SD_GPT_FLAG_NO_AUTO); + + if (pflags & SD_GPT_FLAG_NO_AUTO) + continue; + + designator = PARTITION_SWAP; + + } else if (sd_id128_equal(type_id, 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 = strdup(node); + if (!generic_node) + return -ENOMEM; + } + + } else if (sd_id128_equal(type_id, SD_GPT_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; + + designator = PARTITION_TMP; + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + + } else if (sd_id128_equal(type_id, SD_GPT_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; + } + } + + designator = PARTITION_VAR; + rw = !(pflags & SD_GPT_FLAG_READ_ONLY); + growfs = FLAGS_SET(pflags, SD_GPT_FLAG_GROWFS); + } + + if (designator != _PARTITION_DESIGNATOR_INVALID) { + _cleanup_free_ char *t = NULL, *o = NULL, *l = NULL; + _cleanup_close_ int mount_node_fd = -1; + const char *options = NULL; + + if (m->partitions[designator].found) { + /* 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. */ + + if (!PARTITION_DESIGNATOR_VERSIONED(designator) || + strverscmp_improved(m->partitions[designator].label, label) >= 0) + continue; + + dissected_partition_done(m->partitions + designator); + } + + 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; + } + + 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, designator); + if (options) { + o = strdup(options); + if (!o) + return -ENOMEM; + } + + m->partitions[designator] = (DissectedPartition) { + .found = true, + .partno = nr, + .rw = rw, + .growfs = growfs, + .architecture = architecture, + .node = TAKE_PTR(node), + .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, + }; + } + + } 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 = strdup(node); + if (!generic_node) + return -ENOMEM; + } + + break; + + case 0xEA: { /* Boot Loader Spec extended $BOOT partition */ + _cleanup_close_ int mount_node_fd = -1; + _cleanup_free_ char *o = NULL; + sd_id128_t id = SD_ID128_NULL; + const char *sid, *options = NULL; + + /* 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; + } + + sid = blkid_partition_get_uuid(pp); + if (sid) + (void) sd_id128_from_string(sid, &id); + + 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(node), + .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, + }; + + break; + }} + } + } + + if (m->partitions[PARTITION_ROOT].found) { + /* If we found the primary arch, then invalidate the secondary and other arch to avoid any + * ambiguities, since we never want to mount the secondary or other arch in this case. */ + m->partitions[PARTITION_ROOT_SECONDARY].found = false; + m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found = false; + m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG].found = false; + m->partitions[PARTITION_USR_SECONDARY].found = false; + m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false; + m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found = false; + + m->partitions[PARTITION_ROOT_OTHER].found = false; + m->partitions[PARTITION_ROOT_OTHER_VERITY].found = false; + m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG].found = false; + m->partitions[PARTITION_USR_OTHER].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false; + + } else if (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. */ + + else if (m->partitions[PARTITION_ROOT_SECONDARY].found) { + + /* No root partition found but there's one for the secondary architecture? Then upgrade + * secondary arch to first and invalidate the other arch. */ + + log_debug("No root partition found of the native architecture, falling back to a root " + "partition of the secondary architecture."); + + m->partitions[PARTITION_ROOT] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_SECONDARY]); + m->partitions[PARTITION_ROOT_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_SECONDARY_VERITY]); + m->partitions[PARTITION_ROOT_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG]); + + m->partitions[PARTITION_USR] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY]); + m->partitions[PARTITION_USR_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY_VERITY]); + m->partitions[PARTITION_USR_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG]); + + m->partitions[PARTITION_ROOT_OTHER].found = false; + m->partitions[PARTITION_ROOT_OTHER_VERITY].found = false; + m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG].found = false; + m->partitions[PARTITION_USR_OTHER].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false; + + } else if (m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found || + m->partitions[PARTITION_ROOT_SECONDARY_VERITY_SIG].found) + return -EADDRNOTAVAIL; /* as above */ + + else if (m->partitions[PARTITION_ROOT_OTHER].found) { + + /* No root or secondary partition found but there's one for another architecture? Then + * upgrade the other architecture to first. */ + + log_debug("No root partition found of the native architecture or the secondary architecture, " + "falling back to a root partition of a non-native architecture (%s).", + architecture_to_string(m->partitions[PARTITION_ROOT_OTHER].architecture)); + + m->partitions[PARTITION_ROOT] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_OTHER]); + m->partitions[PARTITION_ROOT_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_OTHER_VERITY]); + m->partitions[PARTITION_ROOT_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_ROOT_OTHER_VERITY_SIG]); + + m->partitions[PARTITION_USR] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER]); + m->partitions[PARTITION_USR_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER_VERITY]); + m->partitions[PARTITION_USR_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER_VERITY_SIG]); + } + + /* 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) { + /* Invalidate secondary and other arch /usr/ if we found the primary arch */ + m->partitions[PARTITION_USR_SECONDARY].found = false; + m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false; + m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found = false; + + m->partitions[PARTITION_USR_OTHER].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false; + + } else if (m->partitions[PARTITION_USR_VERITY].found || + m->partitions[PARTITION_USR_VERITY_SIG].found) + return -EADDRNOTAVAIL; /* as above */ + + else if (m->partitions[PARTITION_USR_SECONDARY].found) { + + log_debug("No usr partition found of the native architecture, falling back to a usr " + "partition of the secondary architecture."); + + /* Upgrade secondary arch to primary */ + m->partitions[PARTITION_USR] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY]); + m->partitions[PARTITION_USR_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY_VERITY]); + m->partitions[PARTITION_USR_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG]); + + m->partitions[PARTITION_USR_OTHER].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY].found = false; + m->partitions[PARTITION_USR_OTHER_VERITY_SIG].found = false; + + } else if (m->partitions[PARTITION_USR_SECONDARY_VERITY].found || + m->partitions[PARTITION_USR_SECONDARY_VERITY_SIG].found) + return -EADDRNOTAVAIL; /* as above */ + + else if (m->partitions[PARTITION_USR_OTHER].found) { + + log_debug("No usr partition found of the native architecture or the secondary architecture, " + "falling back to a usr partition of a non-native architecture (%s).", + architecture_to_string(m->partitions[PARTITION_ROOT_OTHER].architecture)); + + /* Upgrade other arch to primary */ + m->partitions[PARTITION_USR] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER]); + m->partitions[PARTITION_USR_VERITY] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER_VERITY]); + m->partitions[PARTITION_USR_VERITY_SIG] = TAKE_PARTITION(m->partitions[PARTITION_USR_OTHER_VERITY_SIG]); + } + + /* Hmm, we found a signature partition but no Verity data? Something is off. */ + 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) { + _cleanup_close_ int mount_node_fd = -1; + _cleanup_free_ char *o = 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; + } + + 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(generic_node), + .uuid = generic_uuid, + .mount_options = TAKE_PTR(o), + .mount_node_fd = TAKE_FD(mount_node_fd), + .offset = UINT64_MAX, + .size = UINT64_MAX, + }; + } + } + + /* 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 = + m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR_VERITY_SIG : 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; + m->partitions[verity->designator == PARTITION_USR ? PARTITION_USR : PARTITION_ROOT].rw = false; + } + } + + r = dissected_image_probe_filesystems(m, fd); + if (r < 0) + return r; + + return 0; +} +#endif + +int dissect_image_file( + const char *path, + const VeritySettings *verity, + const MountOptions *mount_options, + DissectImageFlags flags, + DissectedImage **ret) { + +#if HAVE_BLKID + _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; + _cleanup_close_ int fd = -1; + int r; + + assert(path); + assert(ret); + + 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 = dissect_image(m, fd, path, verity, mount_options, flags); + if (r < 0) + return r; + + *ret = TAKE_PTR(m); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +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->extension_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; + _cleanup_free_ char *fsck_path = NULL; + + 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 = find_executable("fsck", &fsck_path); + /* We proceed anyway if we can't determine whether the fsck + * binary for some specific fstype exists, + * but the lack of the main fsck binary should be considered + * an error. */ + if (r < 0) + return log_error_errno(r, "Cannot find fsck binary: %m"); + + r = safe_fork_full( + "(fsck)", + &node_fd, 1, /* Leave the node fd open */ + FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_NULL_STDIO|FORK_CLOEXEC_OFF, + &pid); + if (r < 0) + return log_debug_errno(r, "Failed to fork off fsck: %m"); + if (r == 0) { + /* Child */ + execl(fsck_path, fsck_path, "-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 %s: %m", fsck_path); + + 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, const char *mount_path) { + _cleanup_close_ int mount_fd = -1, node_fd = -1; + uint64_t size, newsize; + int r; + + 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); + + mount_fd = open(mount_path, O_RDONLY|O_DIRECTORY|O_CLOEXEC); + if (mount_fd < 0) + return log_debug_errno(errno, "Failed to open mountd file system %s: %m", mount_path); + + log_debug("Resizing \"%s\" to %"PRIu64" bytes...", mount_path, size); + r = resize_fs(mount_fd, size, &newsize); + if (r < 0) + return log_debug_errno(r, "Failed to resize \"%s\" to %"PRIu64" bytes: %m", mount_path, size); + + if (newsize == size) + log_debug("Successfully resized \"%s\" to %s bytes.", + mount_path, FORMAT_BYTES(newsize)); + else { + assert(newsize < size); + log_debug("Successfully resized \"%s\" to %s bytes (%"PRIu64" bytes lost due to blocksize).", + mount_path, FORMAT_BYTES(newsize), size - newsize); + } + + return 0; +} + +static int mount_partition( + DissectedPartition *m, + const char *where, + const char *directory, + uid_t uid_shift, + uid_t uid_range, + DissectImageFlags flags) { + + _cleanup_free_ char *chased = NULL, *options = NULL; + const char *p, *node, *fstype; + bool rw, remap_uid_gid = false; + int r; + + assert(m); + assert(where); + + if (m->mount_node_fd < 0) + return 0; + + /* Use decrypted node and matching fstype if available, otherwise use the original device */ + node = FORMAT_PROC_FD_PATH(m->mount_node_fd); + fstype = m->decrypted_node ? m->decrypted_fstype: m->fstype; + + 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; + + rw = m->rw && !(flags & DISSECT_IMAGE_MOUNT_READ_ONLY); + + if (FLAGS_SET(flags, DISSECT_IMAGE_FSCK) && rw) { + r = run_fsck(m->mount_node_fd, fstype); + if (r < 0) + return r; + } + + 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); + if (r < 0 && r != -EROFS) + return r; + + r = chase_symlinks(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 requested, turn on discard support. */ + if (fstype_can_discard(fstype) && + ((flags & DISSECT_IMAGE_DISCARD) || + ((flags & DISSECT_IMAGE_DISCARD_ON_LOOP) && is_loop_device(m->node) > 0))) { + options = strdup("discard"); + if (!options) + return -ENOMEM; + } + + if (uid_is_valid(uid_shift) && uid_shift != 0) { + + if (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; + } else if (FLAGS_SET(flags, DISSECT_IMAGE_MOUNT_IDMAPPED)) + remap_uid_gid = true; + } + + if (!isempty(m->mount_options)) + if (!strextend_with_separator(&options, ",", m->mount_options)) + return -ENOMEM; + + /* 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 usecase 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 && STRPTR_IN_SET(fstype, "ext3", "ext4", "xfs", "btrfs")) + if (!strextend_with_separator(&options, ",", "norecovery")) + return -ENOMEM; + + r = mount_nofollow_verbose(LOG_DEBUG, node, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options); + if (r < 0) + return r; + + if (rw && m->growfs && FLAGS_SET(flags, DISSECT_IMAGE_GROWFS)) + (void) fs_grow(node, p); + + if (remap_uid_gid) { + r = remount_idmap(p, uid_shift, uid_range, UID_INVALID, REMOUNT_IDMAPPING_HOST_ROOT); + if (r < 0) + return r; + } + + return 1; +} + +static int mount_root_tmpfs(const char *where, uid_t uid_shift, 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 (uid_is_valid(uid_shift)) { + 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; +} + +int dissected_image_mount( + DissectedImage *m, + const char *where, + uid_t uid_shift, + uid_t uid_range, + DissectImageFlags flags) { + + int r, xbootldr_mounted; + + assert(m); + assert(where); + + /* 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 + */ + + 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 ((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(m->partitions + PARTITION_ROOT, where, NULL, uid_shift, uid_range, flags); + else + r = mount_root_tmpfs(where, uid_shift, flags); + if (r < 0) + return r; + + /* For us mounting root always means mounting /usr as well */ + r = mount_partition(m->partitions + PARTITION_USR, where, "/usr", uid_shift, uid_range, flags); + if (r < 0) + return r; + + if ((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; + + 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 = path_is_extension_tree(where, m->image_name, FLAGS_SET(flags, DISSECT_IMAGE_RELAX_SYSEXT_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(m->partitions + PARTITION_HOME, where, "/home", uid_shift, uid_range, flags); + if (r < 0) + return r; + + r = mount_partition(m->partitions + PARTITION_SRV, where, "/srv", uid_shift, uid_range, flags); + if (r < 0) + return r; + + r = mount_partition(m->partitions + PARTITION_VAR, where, "/var", uid_shift, uid_range, flags); + if (r < 0) + return r; + + r = mount_partition(m->partitions + PARTITION_TMP, where, "/var/tmp", uid_shift, uid_range, flags); + if (r < 0) + return r; + + xbootldr_mounted = mount_partition(m->partitions + PARTITION_XBOOTLDR, where, "/boot", uid_shift, uid_range, flags); + if (xbootldr_mounted < 0) + return xbootldr_mounted; + + if (m->partitions[PARTITION_ESP].found) { + int esp_done = false; + + /* Mount the ESP to /efi if it exists. If it doesn't exist, use /boot instead, but only if it + * exists and is empty, and we didn't already mount the XBOOTLDR partition into it. */ + + r = chase_symlinks("/efi", where, CHASE_PREFIX_ROOT, NULL, NULL); + if (r < 0) { + if (r != -ENOENT) + return r; + + /* /efi doesn't exist. Let's see if /boot is suitable then */ + + if (!xbootldr_mounted) { + _cleanup_free_ char *p = NULL; + + r = chase_symlinks("/boot", where, CHASE_PREFIX_ROOT, &p, NULL); + if (r < 0) { + if (r != -ENOENT) + return r; + } else if (dir_is_empty(p, /* ignore_hidden_or_backup= */ false) > 0) { + /* It exists and is an empty directory. Let's mount the ESP there. */ + r = mount_partition(m->partitions + PARTITION_ESP, where, "/boot", uid_shift, uid_range, flags); + if (r < 0) + return r; + + esp_done = true; + } + } + } + + if (!esp_done) { + /* OK, let's mount the ESP now to /efi (possibly creating the dir if missing) */ + + r = mount_partition(m->partitions + PARTITION_ESP, where, "/efi", uid_shift, uid_range, 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, + DissectImageFlags flags) { + + int r; + + assert(m); + assert(where); + + r = dissected_image_mount(m, where, uid_shift, uid_range, 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 < 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) { + /* 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 = -1; + 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 inline 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_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL; + _cleanup_free_ char *node = NULL, *name = NULL; + _cleanup_close_ int mount_node_fd = -1; + 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_(sym_crypt_freep) struct crypt_device *existing_cd = NULL; + _cleanup_close_ int fd = -1; + + /* 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: + if (!restore_deferred_remove){ + /* 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; + } + } + + 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(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: + /* 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); + + 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 -EFBIG; + + 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_EXTENSION_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_EXTENSION_RELEASE] = "extension-release\0", /* Used only for logging. */ + [META_HAS_INIT_SYSTEM] = "has-init-system\0", /* ditto */ + }; + + _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL, **extension_release = NULL; + _cleanup_close_pair_ int error_pipe[2] = { -1, -1 }; + _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] = -1; + 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|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_INVALID, + UID_INVALID, + 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; + const char *p; + + if (!paths[k]) + continue; + + fds[2*k] = safe_close(fds[2*k]); + + switch (k) { + + case META_EXTENSION_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, m->image_name, /* relax_extension_release_check= */ false, NULL, &fd); + if (r < 0) + fd = r; /* Propagate the error. */ + 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_symlinks(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), false); + if (r < 0) + goto inner_fail; + + goto next; + } + + default: + NULSTR_FOREACH(p, paths[k]) { + fd = chase_symlinks_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_EXTENSION_RELEASE: + r = load_env_file_pairs(f, "extension-release", &extension_release); + if (r < 0) + log_debug_errno(r, "Failed to read extension 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->extension_release, extension_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; +} + +int dissect_loop_device( + LoopDevice *loop, + const VeritySettings *verity, + const MountOptions *mount_options, + DissectImageFlags flags, + DissectedImage **ret) { + +#if HAVE_BLKID + _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; + int r; + + assert(loop); + assert(ret); + + r = dissected_image_new(loop->backing_file ?: loop->node, &m); + if (r < 0) + return r; + + m->loop = loop_device_ref(loop); + + r = dissect_image(m, loop->fd, loop->node, verity, mount_options, flags); + if (r < 0) + return r; + + *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, + DissectImageFlags flags, + DissectedImage **ret) { + + const char *name; + int r; + + assert(loop); + assert(loop->fd >= 0); + + name = ASSERT_PTR(loop->backing_file ?: loop->node); + + r = dissect_loop_device(loop, verity, mount_options, flags, ret); + switch (r) { + + case -EOPNOTSUPP: + return log_error_errno(r, "Dissecting images is not supported, compiled without blkid support."); + + case -ENOPKG: + return log_error_errno(r, "%s: Couldn't identify a suitable partition table or file system.", name); + + case -ENOMEDIUM: + return log_error_errno(r, "%s: The image does not pass validation.", name); + + case -EADDRNOTAVAIL: + return log_error_errno(r, "%s: No root partition for specified root hash found.", name); + + case -ENOTUNIQ: + return log_error_errno(r, "%s: Multiple suitable root partitions found in image.", name); + + case -ENXIO: + return log_error_errno(r, "%s: No suitable root partition found in image.", name); + + case -EPROTONOSUPPORT: + return log_error_errno(r, "Device '%s' is loopback block device with partition scanning turned off, please turn it on.", name); + + case -ENOTBLK: + return log_error_errno(r, "%s: Image is not a block device.", name); + + case -EBADR: + return log_error_errno(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)); + + default: + if (r < 0) + return log_error_errno(r, "Failed to dissect image '%s': %m", name); + + return r; + } +} + +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 = options)) { + LIST_REMOVE(mount_options, options, m); + 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, + DissectImageFlags flags, + char **ret_directory, + 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_(rmdir_and_freep) char *created_dir = NULL; + _cleanup_free_ char *temp = 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_directory); + 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 = tempfn_random_child(NULL, program_invocation_short_name, &temp); + if (r < 0) + return log_error_errno(r, "Failed to generate temporary mount directory: %m"); + + r = loop_device_make_by_path( + image, + FLAGS_SET(flags, DISSECT_IMAGE_DEVICE_READ_ONLY) ? O_RDONLY : O_RDWR, + 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, NULL, 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(temp, 0700); + if (r < 0) + return log_error_errno(r, "Failed to create mount point: %m"); + + created_dir = TAKE_PTR(temp); + + r = dissected_image_mount_and_warn(dissected_image, created_dir, UID_INVALID, UID_INVALID, 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"); + + *ret_directory = TAKE_PTR(created_dir); + *ret_loop_device = TAKE_PTR(d); + + return 0; +} + +static const char *const partition_designator_table[] = { + [PARTITION_ROOT] = "root", + [PARTITION_ROOT_SECONDARY] = "root-secondary", + [PARTITION_ROOT_OTHER] = "root-other", + [PARTITION_USR] = "usr", + [PARTITION_USR_SECONDARY] = "usr-secondary", + [PARTITION_USR_OTHER] = "usr-other", + [PARTITION_HOME] = "home", + [PARTITION_SRV] = "srv", + [PARTITION_ESP] = "esp", + [PARTITION_XBOOTLDR] = "xbootldr", + [PARTITION_SWAP] = "swap", + [PARTITION_ROOT_VERITY] = "root-verity", + [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity", + [PARTITION_ROOT_OTHER_VERITY] = "root-other-verity", + [PARTITION_USR_VERITY] = "usr-verity", + [PARTITION_USR_SECONDARY_VERITY] = "usr-secondary-verity", + [PARTITION_USR_OTHER_VERITY] = "usr-other-verity", + [PARTITION_ROOT_VERITY_SIG] = "root-verity-sig", + [PARTITION_ROOT_SECONDARY_VERITY_SIG] = "root-secondary-verity-sig", + [PARTITION_ROOT_OTHER_VERITY_SIG] = "root-other-verity-sig", + [PARTITION_USR_VERITY_SIG] = "usr-verity-sig", + [PARTITION_USR_SECONDARY_VERITY_SIG] = "usr-secondary-verity-sig", + [PARTITION_USR_OTHER_VERITY_SIG] = "usr-other-verity-sig", + [PARTITION_TMP] = "tmp", + [PARTITION_VAR] = "var", +}; + +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 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_sysext_scope) { + + _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); + assert(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_SYSEXT_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, + -1, + 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, + 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, + 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"); + + 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_INVALID, UID_INVALID, 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; + + assert(!isempty(required_host_os_release_id)); + + r = load_extension_release_pairs(dest, dissected_image->image_name, relax_extension_release_check, &extension_release); + 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, + required_host_os_release_sysext_level, + required_sysext_scope, + extension_release); + 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"); + + return 0; +} + +DEFINE_STRING_TABLE_LOOKUP(partition_designator, PartitionDesignator); |