/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include #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 "copy.h" #include "crypt-util.h" #include "def.h" #include "device-nodes.h" #include "device-util.h" #include "dissect-image.h" #include "env-file.h" #include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "gpt.h" #include "hexdecoct.h" #include "hostname-util.h" #include "id128-util.h" #include "linux-3.13/dm-ioctl.h" #include "missing.h" #include "mount-util.h" #include "mountpoint-util.h" #include "os-util.h" #include "path-util.h" #include "process-util.h" #include "raw-clone.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" int probe_filesystem(const char *node, 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 ambigous results, and an * different error otherwise. */ #if HAVE_BLKID _cleanup_(blkid_free_probep) blkid_probe b = NULL; const char *fstype; int r; errno = 0; b = blkid_new_probe_from_filename(node); if (!b) return -errno ?: -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) { log_debug("No type detected on partition %s", node); goto not_found; } if (r == -2) { log_debug("Results ambiguous for partition %s", node); return -EUCLEAN; } if (r != 0) return -errno ?: -EIO; (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); if (fstype) { char *t; t = strdup(fstype); if (!t) return -ENOMEM; *ret_fstype = t; return 1; } not_found: *ret_fstype = NULL; return 0; #else return -EOPNOTSUPP; #endif } #if HAVE_BLKID /* Detect RPMB and Boot partitions, which are not listed by blkid. * See https://github.com/systemd/systemd/issues/5806. */ static bool device_is_mmc_special_partition(sd_device *d) { const char *sysname; assert(d); if (sd_device_get_sysname(d, &sysname) < 0) return false; return startswith(sysname, "mmcblk") && (endswith(sysname, "rpmb") || endswith(sysname, "boot0") || endswith(sysname, "boot1")); } static bool device_is_block(sd_device *d) { const char *ss; assert(d); if (sd_device_get_subsystem(d, &ss) < 0) return false; return streq(ss, "block"); } static int enumerator_for_parent(sd_device *d, sd_device_enumerator **ret) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; int r; assert(d); assert(ret); r = sd_device_enumerator_new(&e); if (r < 0) return r; r = sd_device_enumerator_allow_uninitialized(e); if (r < 0) return r; r = sd_device_enumerator_add_match_parent(e, d); if (r < 0) return r; *ret = TAKE_PTR(e); return 0; } /* how many times to wait for the device nodes to appear */ #define N_DEVICE_NODE_LIST_ATTEMPTS 10 static int wait_for_partitions_to_appear( int fd, sd_device *d, unsigned num_partitions, DissectImageFlags flags, sd_device_enumerator **ret_enumerator) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; sd_device *q; unsigned n; int r; assert(fd >= 0); assert(d); assert(ret_enumerator); r = enumerator_for_parent(d, &e); if (r < 0) return r; /* Count the partitions enumerated by the kernel */ n = 0; FOREACH_DEVICE(e, q) { if (sd_device_get_devnum(q, NULL) < 0) continue; if (!device_is_block(q)) continue; if (device_is_mmc_special_partition(q)) continue; if (!FLAGS_SET(flags, DISSECT_IMAGE_NO_UDEV)) { r = device_wait_for_initialization(q, "block", NULL); if (r < 0) return r; } n++; } if (n == num_partitions + 1) { *ret_enumerator = TAKE_PTR(e); return 0; /* success! */ } if (n > num_partitions + 1) return log_debug_errno(SYNTHETIC_ERRNO(EIO), "blkid and kernel partition lists do not match."); /* The kernel has probed fewer partitions than blkid? Maybe the kernel prober is still running or it * got EBUSY because udev already opened the device. Let's reprobe the device, which is a synchronous * call that waits until probing is complete. */ for (unsigned j = 0; ; j++) { if (j++ > 20) return -EBUSY; if (ioctl(fd, BLKRRPART, 0) >= 0) break; r = -errno; if (r == -EINVAL) { struct loop_info64 info; /* If we are running on a loop device that has partition scanning off, return * an explicit recognizable error about this, so that callers can generate a * proper message explaining the situation. */ if (ioctl(fd, LOOP_GET_STATUS64, &info) >= 0 && (info.lo_flags & LO_FLAGS_PARTSCAN) == 0) { log_debug("Device is a loop device and partition scanning is off!"); return -EPROTONOSUPPORT; } } if (r != -EBUSY) return r; /* If something else has the device open, such as an udev rule, the ioctl will return * EBUSY. Since there's no way to wait until it isn't busy anymore, let's just wait a bit, * and try again. * * This is really something they should fix in the kernel! */ (void) usleep(50 * USEC_PER_MSEC); } return -EAGAIN; /* no success yet, try again */ } static int loop_wait_for_partitions_to_appear( int fd, sd_device *d, unsigned num_partitions, DissectImageFlags flags, sd_device_enumerator **ret_enumerator) { _cleanup_(sd_device_unrefp) sd_device *device = NULL; int r; assert(fd >= 0); assert(d); assert(ret_enumerator); log_debug("Waiting for device (parent + %d partitions) to appear...", num_partitions); if (!FLAGS_SET(flags, DISSECT_IMAGE_NO_UDEV)) { r = device_wait_for_initialization(d, "block", &device); if (r < 0) return r; } else device = sd_device_ref(d); for (unsigned i = 0; i < N_DEVICE_NODE_LIST_ATTEMPTS; i++) { r = wait_for_partitions_to_appear(fd, device, num_partitions, flags, ret_enumerator); if (r != -EAGAIN) return r; } return log_debug_errno(SYNTHETIC_ERRNO(ENXIO), "Kernel partitions dit not appear within %d attempts", N_DEVICE_NODE_LIST_ATTEMPTS); } #endif int dissect_image( int fd, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DissectedImage **ret) { #if HAVE_BLKID sd_id128_t root_uuid = SD_ID128_NULL, verity_uuid = SD_ID128_NULL; _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; bool is_gpt, is_mbr, generic_rw, multiple_generic = false; _cleanup_(sd_device_unrefp) sd_device *d = NULL; _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; _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; struct stat st; sd_device *q; unsigned i; assert(fd >= 0); assert(ret); assert(root_hash || root_hash_size == 0); /* Probes a disk image, and returns information about what it found in *ret. * * Returns -ENOPKG if no suitable partition table or file system could be found. * Returns -EADDRNOTAVAIL if a root hash was specified but no matching root/verity partitions found. */ if (root_hash) { /* 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 (root_hash_size < sizeof(sd_id128_t)) return -EINVAL; memcpy(&root_uuid, root_hash, sizeof(sd_id128_t)); memcpy(&verity_uuid, (const uint8_t*) root_hash + root_hash_size - sizeof(sd_id128_t), sizeof(sd_id128_t)); if (sd_id128_is_null(root_uuid)) return -EINVAL; if (sd_id128_is_null(verity_uuid)) return -EINVAL; } if (fstat(fd, &st) < 0) return -errno; if (!S_ISBLK(st.st_mode)) return -ENOTBLK; b = blkid_new_probe(); if (!b) return -ENOMEM; errno = 0; r = blkid_probe_set_device(b, fd, 0, 0); if (r != 0) return -errno ?: -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)) { log_debug("Failed to identify any partition table."); return -ENOPKG; } if (r != 0) return -errno ?: -EIO; m = new0(DissectedImage, 1); if (!m) return -ENOMEM; r = sd_device_new_from_devnum(&d, 'b', st.st_rdev); if (r < 0) return r; if (!(flags & DISSECT_IMAGE_GPT_ONLY) && (flags & DISSECT_IMAGE_REQUIRE_ROOT)) { const char *usage = NULL; (void) blkid_probe_lookup_value(b, "USAGE", &usage, NULL); if (STRPTR_IN_SET(usage, "filesystem", "crypto")) { _cleanup_free_ char *t = NULL, *n = NULL; const char *fstype = NULL; /* 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; } r = device_path_make_major_minor(st.st_mode, st.st_rdev, &n); if (r < 0) return r; m->partitions[PARTITION_ROOT] = (DissectedPartition) { .found = true, .rw = true, .partno = -1, .architecture = _ARCHITECTURE_INVALID, .fstype = TAKE_PTR(t), .node = TAKE_PTR(n), }; m->encrypted = streq_ptr(fstype, "crypto_LUKS"); r = loop_wait_for_partitions_to_appear(fd, d, 0, flags, &e); if (r < 0) return r; *ret = TAKE_PTR(m); 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; errno = 0; pl = blkid_probe_get_partitions(b); if (!pl) return -errno ?: -ENOMEM; r = loop_wait_for_partitions_to_appear(fd, d, blkid_partlist_numof_partitions(pl), flags, &e); if (r < 0) return r; FOREACH_DEVICE(e, q) { unsigned long long pflags; blkid_partition pp; const char *node; dev_t qn; int nr; r = sd_device_get_devnum(q, &qn); if (r < 0) continue; if (st.st_rdev == qn) continue; if (!device_is_block(q)) continue; if (device_is_mmc_special_partition(q)) continue; r = sd_device_get_devname(q, &node); if (r < 0) continue; pp = blkid_partlist_devno_to_partition(pl, qn); if (!pp) continue; pflags = blkid_partition_get_flags(pp); nr = blkid_partition_get_partno(pp); if (nr < 0) continue; if (is_gpt) { int designator = _PARTITION_DESIGNATOR_INVALID, architecture = _ARCHITECTURE_INVALID; const char *stype, *sid, *fstype = NULL; sd_id128_t type_id, id; bool rw = true; 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; if (sd_id128_equal(type_id, GPT_HOME)) { if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_HOME; rw = !(pflags & GPT_FLAG_READ_ONLY); } else if (sd_id128_equal(type_id, GPT_SRV)) { if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_SRV; rw = !(pflags & GPT_FLAG_READ_ONLY); } else if (sd_id128_equal(type_id, GPT_ESP)) { /* Note that we don't check the GPT_FLAG_NO_AUTO flag for the ESP, as it is not defined * there. We instead check the GPT_FLAG_NO_BLOCK_IO_PROTOCOL, as recommended by the * UEFI spec (See "12.3.3 Number and Location of System Partitions"). */ if (pflags & GPT_FLAG_NO_BLOCK_IO_PROTOCOL) continue; designator = PARTITION_ESP; fstype = "vfat"; } #ifdef GPT_ROOT_NATIVE else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) { if (pflags & 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; designator = PARTITION_ROOT; architecture = native_architecture(); rw = !(pflags & GPT_FLAG_READ_ONLY); } else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE_VERITY)) { if (pflags & GPT_FLAG_NO_AUTO) continue; m->can_verity = true; /* Ignore verity unless a root hash is specified */ if (sd_id128_is_null(verity_uuid) || !sd_id128_equal(verity_uuid, id)) continue; designator = PARTITION_ROOT_VERITY; fstype = "DM_verity_hash"; architecture = native_architecture(); rw = false; } #endif #ifdef GPT_ROOT_SECONDARY else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY)) { if (pflags & 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; designator = PARTITION_ROOT_SECONDARY; architecture = SECONDARY_ARCHITECTURE; rw = !(pflags & GPT_FLAG_READ_ONLY); } else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY_VERITY)) { if (pflags & GPT_FLAG_NO_AUTO) continue; m->can_verity = true; /* Ignore verity unless root has is specified */ if (sd_id128_is_null(verity_uuid) || !sd_id128_equal(verity_uuid, id)) continue; designator = PARTITION_ROOT_SECONDARY_VERITY; fstype = "DM_verity_hash"; architecture = SECONDARY_ARCHITECTURE; rw = false; } #endif else if (sd_id128_equal(type_id, GPT_SWAP)) { if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_SWAP; fstype = "swap"; } else if (sd_id128_equal(type_id, GPT_LINUX_GENERIC)) { if (pflags & GPT_FLAG_NO_AUTO) continue; if (generic_node) multiple_generic = true; else { generic_nr = nr; generic_rw = !(pflags & GPT_FLAG_READ_ONLY); generic_uuid = id; generic_node = strdup(node); if (!generic_node) return -ENOMEM; } } if (designator != _PARTITION_DESIGNATOR_INVALID) { _cleanup_free_ char *t = NULL, *n = NULL; /* First one wins */ if (m->partitions[designator].found) continue; if (fstype) { t = strdup(fstype); if (!t) return -ENOMEM; } n = strdup(node); if (!n) return -ENOMEM; m->partitions[designator] = (DissectedPartition) { .found = true, .partno = nr, .rw = rw, .architecture = architecture, .node = TAKE_PTR(n), .fstype = TAKE_PTR(t), .uuid = id, }; } } else if (is_mbr) { if (pflags != 0x80) /* Bootable flag */ continue; if (blkid_partition_get_type(pp) != 0x83) /* Linux partition */ continue; if (generic_node) multiple_generic = true; else { generic_nr = nr; generic_rw = true; generic_node = strdup(node); if (!generic_node) return -ENOMEM; } } } if (!m->partitions[PARTITION_ROOT].found) { /* No root partition found? Then let's see if ther's one for the secondary architecture. And if not * either, then check if there's a single generic one, and use that. */ if (m->partitions[PARTITION_ROOT_VERITY].found) return -EADDRNOTAVAIL; if (m->partitions[PARTITION_ROOT_SECONDARY].found) { m->partitions[PARTITION_ROOT] = m->partitions[PARTITION_ROOT_SECONDARY]; zero(m->partitions[PARTITION_ROOT_SECONDARY]); m->partitions[PARTITION_ROOT_VERITY] = m->partitions[PARTITION_ROOT_SECONDARY_VERITY]; zero(m->partitions[PARTITION_ROOT_SECONDARY_VERITY]); } else if (flags & DISSECT_IMAGE_REQUIRE_ROOT) { /* If the root has was set, then we won't fallback to a generic node, because the root hash * decides */ if (root_hash) return -EADDRNOTAVAIL; /* If we didn't find a generic node, then we can't fix this up either */ if (!generic_node) return -ENXIO; /* 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; m->partitions[PARTITION_ROOT] = (DissectedPartition) { .found = true, .rw = generic_rw, .partno = generic_nr, .architecture = _ARCHITECTURE_INVALID, .node = TAKE_PTR(generic_node), .uuid = generic_uuid, }; } } if (root_hash) { if (!m->partitions[PARTITION_ROOT_VERITY].found || !m->partitions[PARTITION_ROOT].found) return -EADDRNOTAVAIL; /* If we found the primary root with the hash, then we definitely want to suppress any secondary root * (which would be weird, after all the root hash should only be assigned to one pair of * partitions... */ m->partitions[PARTITION_ROOT_SECONDARY].found = false; m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found = false; /* If we found a verity setup, then the root partition is necessarily read-only. */ m->partitions[PARTITION_ROOT].rw = false; m->verity = true; } blkid_free_probe(b); b = NULL; /* Fill in file system types if we don't know them yet. */ for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { DissectedPartition *p = m->partitions + i; if (!p->found) continue; if (!p->fstype && p->node) { r = probe_filesystem(p->node, &p->fstype); if (r < 0 && r != -EUCLEAN) return r; } if (streq_ptr(p->fstype, "crypto_LUKS")) m->encrypted = true; if (p->fstype && fstype_is_ro(p->fstype)) p->rw = false; } *ret = TAKE_PTR(m); return 0; #else return -EOPNOTSUPP; #endif } DissectedImage* dissected_image_unref(DissectedImage *m) { unsigned i; if (!m) return NULL; for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { free(m->partitions[i].fstype); free(m->partitions[i].node); free(m->partitions[i].decrypted_fstype); free(m->partitions[i].decrypted_node); } free(m->hostname); strv_free(m->machine_info); strv_free(m->os_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 mount_partition( DissectedPartition *m, const char *where, const char *directory, uid_t uid_shift, DissectImageFlags flags) { _cleanup_free_ char *chased = NULL, *options = NULL; const char *p, *node, *fstype; bool rw; int r; assert(m); assert(where); node = m->decrypted_node ?: m->node; fstype = m->decrypted_fstype ?: m->fstype; if (!m->found || !node || !fstype) return 0; /* Stacked encryption? Yuck */ if (streq_ptr(fstype, "crypto_LUKS")) return -ELOOP; rw = m->rw && !(flags & DISSECT_IMAGE_READ_ONLY); if (directory) { r = chase_symlinks(directory, where, CHASE_PREFIX_ROOT, &chased); if (r < 0) return r; p = chased; } else 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)))) { options = strdup("discard"); if (!options) return -ENOMEM; } if (uid_is_valid(uid_shift) && uid_shift != 0 && 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, NULL)) return -ENOMEM; } return mount_verbose(LOG_DEBUG, node, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options); } int dissected_image_mount(DissectedImage *m, const char *where, uid_t uid_shift, DissectImageFlags flags) { int r; assert(m); assert(where); if (!m->partitions[PARTITION_ROOT].found) return -ENXIO; if ((flags & DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY) == 0) { r = mount_partition(m->partitions + PARTITION_ROOT, where, NULL, uid_shift, flags); if (r < 0) return r; if (flags & DISSECT_IMAGE_VALIDATE_OS) { r = path_is_os_tree(where); if (r < 0) return r; if (r == 0) return -EMEDIUMTYPE; } } if (flags & DISSECT_IMAGE_MOUNT_ROOT_ONLY) return 0; r = mount_partition(m->partitions + PARTITION_HOME, where, "/home", uid_shift, flags); if (r < 0) return r; r = mount_partition(m->partitions + PARTITION_SRV, where, "/srv", uid_shift, flags); if (r < 0) return r; if (m->partitions[PARTITION_ESP].found) { const char *mp; /* Mount the ESP to /efi if it exists and is empty. If it doesn't exist, use /boot instead. */ FOREACH_STRING(mp, "/efi", "/boot") { _cleanup_free_ char *p = NULL; r = chase_symlinks(mp, where, CHASE_PREFIX_ROOT, &p); if (r < 0) continue; r = dir_is_empty(p); if (r > 0) { r = mount_partition(m->partitions + PARTITION_ESP, where, mp, uid_shift, flags); if (r < 0) return r; } } } return 0; } #if HAVE_LIBCRYPTSETUP typedef struct DecryptedPartition { struct crypt_device *device; char *name; bool relinquished; } DecryptedPartition; struct DecryptedImage { DecryptedPartition *decrypted; size_t n_decrypted; size_t n_allocated; }; #endif DecryptedImage* decrypted_image_unref(DecryptedImage* d) { #if HAVE_LIBCRYPTSETUP size_t i; int r; if (!d) return NULL; for (i = 0; i < d->n_decrypted; i++) { DecryptedPartition *p = d->decrypted + i; if (p->device && p->name && !p->relinquished) { r = crypt_deactivate(p->device, p->name); if (r < 0) log_debug_errno(r, "Failed to deactivate encrypted partition %s", p->name); } if (p->device) crypt_free(p->device); free(p->name); } free(d); #endif return NULL; } #if HAVE_LIBCRYPTSETUP 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) return -EINVAL; base++; if (isempty(base)) return -EINVAL; name = strjoin(base, suffix); if (!name) return -ENOMEM; if (!filename_is_valid(name)) return -EINVAL; node = strjoin(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_(crypt_freep) struct crypt_device *cd = NULL; 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 = make_dm_name_and_node(m->node, "-decrypted", &name, &node); if (r < 0) return r; if (!GREEDY_REALLOC0(d->decrypted, d->n_allocated, d->n_decrypted + 1)) return -ENOMEM; r = crypt_init(&cd, m->node); if (r < 0) return log_debug_errno(r, "Failed to initialize dm-crypt: %m"); r = crypt_load(cd, CRYPT_LUKS, NULL); if (r < 0) return log_debug_errno(r, "Failed to load LUKS metadata: %m"); r = crypt_activate_by_passphrase(cd, name, CRYPT_ANY_SLOT, passphrase, strlen(passphrase), ((flags & DISSECT_IMAGE_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; } d->decrypted[d->n_decrypted].name = TAKE_PTR(name); d->decrypted[d->n_decrypted].device = TAKE_PTR(cd); d->n_decrypted++; m->decrypted_node = TAKE_PTR(node); return 0; } static int verity_partition( DissectedPartition *m, DissectedPartition *v, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DecryptedImage *d) { _cleanup_free_ char *node = NULL, *name = NULL; _cleanup_(crypt_freep) struct crypt_device *cd = NULL; int r; assert(m); assert(v); if (!root_hash) return 0; if (!m->found || !m->node || !m->fstype) return 0; if (!v->found || !v->node || !v->fstype) return 0; if (!streq(v->fstype, "DM_verity_hash")) return 0; r = make_dm_name_and_node(m->node, "-verity", &name, &node); if (r < 0) return r; if (!GREEDY_REALLOC0(d->decrypted, d->n_allocated, d->n_decrypted + 1)) return -ENOMEM; r = crypt_init(&cd, v->node); if (r < 0) return r; r = crypt_load(cd, CRYPT_VERITY, NULL); if (r < 0) return r; r = crypt_set_data_device(cd, m->node); if (r < 0) return r; r = crypt_activate_by_volume_key(cd, name, root_hash, root_hash_size, CRYPT_ACTIVATE_READONLY); if (r < 0) return r; d->decrypted[d->n_decrypted].name = TAKE_PTR(name); d->decrypted[d->n_decrypted].device = TAKE_PTR(cd); d->n_decrypted++; m->decrypted_node = TAKE_PTR(node); return 0; } #endif int dissected_image_decrypt( DissectedImage *m, const char *passphrase, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DecryptedImage **ret) { #if HAVE_LIBCRYPTSETUP _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL; unsigned i; int r; #endif assert(m); assert(root_hash || 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 (root_hash && root_hash_size < sizeof(sd_id128_t)) return -EINVAL; if (!m->encrypted && !m->verity) { *ret = NULL; return 0; } #if HAVE_LIBCRYPTSETUP d = new0(DecryptedImage, 1); if (!d) return -ENOMEM; for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { DissectedPartition *p = m->partitions + i; int 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(p, m->partitions + k, root_hash, root_hash_size, flags, d); if (r < 0) return r; } if (!p->decrypted_fstype && p->decrypted_node) { r = probe_filesystem(p->decrypted_node, &p->decrypted_fstype); if (r < 0 && r != -EUCLEAN) return r; } } *ret = TAKE_PTR(d); return 1; #else return -EOPNOTSUPP; #endif } int dissected_image_decrypt_interactively( DissectedImage *m, const char *passphrase, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DecryptedImage **ret) { _cleanup_strv_free_erase_ char **z = NULL; int n = 3, r; if (passphrase) n--; for (;;) { r = dissected_image_decrypt(m, passphrase, root_hash, root_hash_size, flags, ret); 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", USEC_INFINITY, 0, &z); if (r < 0) return log_error_errno(r, "Failed to query for passphrase: %m"); passphrase = z[0]; } } #if HAVE_LIBCRYPTSETUP static int deferred_remove(DecryptedPartition *p) { struct dm_ioctl dm = { .version = { DM_VERSION_MAJOR, DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL }, .data_size = sizeof(dm), .flags = DM_DEFERRED_REMOVE, }; _cleanup_close_ int fd = -1; assert(p); /* Unfortunately, libcryptsetup doesn't provide a proper API for this, hence call the ioctl() directly. */ fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC); if (fd < 0) return -errno; if (strlen(p->name) > sizeof(dm.name)) return -ENAMETOOLONG; strncpy(dm.name, p->name, sizeof(dm.name)); if (ioctl(fd, DM_DEV_REMOVE, &dm)) return -errno; return 0; } #endif int decrypted_image_relinquish(DecryptedImage *d) { #if HAVE_LIBCRYPTSETUP size_t i; int r; #endif 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 for (i = 0; i < d->n_decrypted; i++) { DecryptedPartition *p = d->decrypted + i; if (p->relinquished) continue; r = deferred_remove(p); 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 root_hash_load(const char *image, void **ret, size_t *ret_size) { _cleanup_free_ char *text = NULL; _cleanup_free_ void *k = NULL; size_t l; int r; assert(image); assert(ret); assert(ret_size); if (is_device_path(image)) { /* If we are asked to load the root hash for a device node, exit early */ *ret = NULL; *ret_size = 0; return 0; } r = getxattr_malloc(image, "user.verity.roothash", &text, true); if (r < 0) { char *fn, *e, *n; if (!IN_SET(r, -ENODATA, -EOPNOTSUPP, -ENOENT)) return r; fn = newa(char, strlen(image) + STRLEN(".roothash") + 1); n = stpcpy(fn, image); e = endswith(fn, ".raw"); if (e) n = e; strcpy(n, ".roothash"); r = read_one_line_file(fn, &text); if (r == -ENOENT) { *ret = NULL; *ret_size = 0; return 0; } if (r < 0) return r; } r = unhexmem(text, strlen(text), &k, &l); if (r < 0) return r; if (l < sizeof(sd_id128_t)) return -EINVAL; *ret = TAKE_PTR(k); *ret_size = l; return 1; } int dissected_image_acquire_metadata(DissectedImage *m) { enum { META_HOSTNAME, META_MACHINE_ID, META_MACHINE_INFO, META_OS_RELEASE, _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", }; _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL; _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, k; int fds[2 * _META_MAX], r; BLOCK_SIGNALS(SIGCHLD); assert(m); for (; n_meta_initialized < _META_MAX; n_meta_initialized ++) 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; 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) { r = dissected_image_mount(m, t, UID_INVALID, DISSECT_IMAGE_READ_ONLY|DISSECT_IMAGE_MOUNT_ROOT_ONLY|DISSECT_IMAGE_VALIDATE_OS); if (r < 0) { log_debug_errno(r, "Failed to mount dissected image: %m"); _exit(EXIT_FAILURE); } for (k = 0; k < _META_MAX; k++) { _cleanup_close_ int fd = -1; const char *p; fds[2*k] = safe_close(fds[2*k]); 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]); continue; } r = copy_bytes(fd, fds[2*k+1], (uint64_t) -1, 0); if (r < 0) _exit(EXIT_FAILURE); fds[2*k+1] = safe_close(fds[2*k+1]); } _exit(EXIT_SUCCESS); } for (k = 0; k < _META_MAX; k++) { _cleanup_fclose_ FILE *f = NULL; fds[2*k+1] = safe_close(fds[2*k+1]); f = fdopen(fds[2*k], "r"); if (!f) { r = -errno; goto finish; } fds[2*k] = -1; switch (k) { case META_HOSTNAME: r = read_etc_hostname_stream(f, &hostname); if (r < 0) log_debug_errno(r, "Failed to read /etc/hostname: %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: %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 is empty."); else log_debug("/etc/machine-id 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: %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: %m"); break; } } r = wait_for_terminate_and_check("(sd-dissect)", child, 0); child = 0; if (r < 0) goto finish; if (r != EXIT_SUCCESS) return -EPROTO; 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); finish: for (k = 0; k < n_meta_initialized; k++) safe_close_pair(fds + 2*k); return r; } int dissect_image_and_warn( int fd, const char *name, const void *root_hash, size_t root_hash_size, DissectImageFlags flags, DissectedImage **ret) { _cleanup_free_ char *buffer = NULL; int r; if (!name) { r = fd_get_path(fd, &buffer); if (r < 0) return r; name = buffer; } r = dissect_image(fd, root_hash, root_hash_size, 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, "Couldn't identify a suitable partition table or file system in '%s'.", name); case -EADDRNOTAVAIL: return log_error_errno(r, "No root partition for specified root hash found in '%s'.", name); case -ENOTUNIQ: return log_error_errno(r, "Multiple suitable root partitions found in image '%s'.", name); case -ENXIO: return log_error_errno(r, "No suitable root partition found in image '%s'.", name); case -EPROTONOSUPPORT: return log_error_errno(r, "Device '%s' is loopback block device with partition scanning turned off, please turn it on.", name); default: if (r < 0) return log_error_errno(r, "Failed to dissect image '%s': %m", name); return r; } } static const char *const partition_designator_table[] = { [PARTITION_ROOT] = "root", [PARTITION_ROOT_SECONDARY] = "root-secondary", [PARTITION_HOME] = "home", [PARTITION_SRV] = "srv", [PARTITION_ESP] = "esp", [PARTITION_SWAP] = "swap", [PARTITION_ROOT_VERITY] = "root-verity", [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity", }; DEFINE_STRING_TABLE_LOOKUP(partition_designator, int);