/* SPDX-License-Identifier: LGPL-2.1+ */ #if HAVE_VALGRIND_MEMCHECK_H #include #endif #include #include #include #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 "dm-util.h" #include "env-file.h" #include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "fsck-util.h" #include "gpt.h" #include "hexdecoct.h" #include "hostname-util.h" #include "id128-util.h" #include "mkdir.h" #include "mount-util.h" #include "mountpoint-util.h" #include "namespace-util.h" #include "nulstr-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 ambiguous 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_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) { log_debug("No type detected on partition %s", node); goto not_found; } if (r == -2) return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), "Results ambiguous for partition %s", node); if (r != 0) return errno_or_else(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", USEC_INFINITY, 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) { /* If we are running on a block device that has partition scanning off, return an * explicit recognizable error about this, so that callers can generate a proper * message explaining the situation. */ r = blockdev_partscan_enabled(fd); if (r < 0) return r; if (r == 0) return log_debug_errno(EPROTONOSUPPORT, "Device is a loop device and partition scanning is off!"); return -EINVAL; /* original error */ } 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", USEC_INFINITY, &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); } 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 | GPT_FLAG_REQUIRED_PARTITION | GPT_FLAG_NO_BLOCK_IO_PROTOCOL | 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 int dissect_image( int fd, const void *root_hash, size_t root_hash_size, const char *verity_data, const MountOptions *mount_options, 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); 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. */ 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_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); 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)) || (flags & DISSECT_IMAGE_NO_PARTITION_TABLE)) { 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, *o = NULL; const char *fstype = NULL, *options = 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->single_file_system = true; m->verity = root_hash && verity_data; m->can_verity = !!verity_data; options = mount_options_from_part(mount_options, 0); if (options) { o = strdup(options); if (!o) return -ENOMEM; } m->partitions[PARTITION_ROOT] = (DissectedPartition) { .found = true, .rw = !m->verity, .partno = -1, .architecture = _ARCHITECTURE_INVALID, .fstype = TAKE_PTR(t), .node = TAKE_PTR(n), .mount_options = TAKE_PTR(o), }; m->encrypted = streq_ptr(fstype, "crypto_LUKS"); /* Even on a single partition we need to wait for udev to create the * /dev/block/X:Y symlink to /dev/loopZ */ 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_or_else(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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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"; } else if (sd_id128_equal(type_id, GPT_XBOOTLDR)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_XBOOTLDR; rw = !(pflags & GPT_FLAG_READ_ONLY); } #ifdef GPT_ROOT_NATIVE else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_SWAP; fstype = "swap"; } else if (sd_id128_equal(type_id, GPT_LINUX_GENERIC)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); 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; } } else if (sd_id128_equal(type_id, GPT_TMP)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_TMP; rw = !(pflags & GPT_FLAG_READ_ONLY); } else if (sd_id128_equal(type_id, GPT_VAR)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY); if (pflags & 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(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, ignoring."); continue; } } designator = PARTITION_VAR; rw = !(pflags & GPT_FLAG_READ_ONLY); } if (designator != _PARTITION_DESIGNATOR_INVALID) { _cleanup_free_ char *t = NULL, *n = NULL, *o = NULL; const char *options = 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; options = mount_options_from_part(mount_options, nr); if (options) { o = strdup(options); if (!o) return -ENOMEM; } m->partitions[designator] = (DissectedPartition) { .found = true, .partno = nr, .rw = rw, .architecture = architecture, .node = TAKE_PTR(n), .fstype = TAKE_PTR(t), .uuid = id, .mount_options = TAKE_PTR(o), }; } } 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_node = strdup(node); if (!generic_node) return -ENOMEM; } break; case 0xEA: { /* Boot Loader Spec extended $BOOT partition */ _cleanup_free_ char *n = NULL, *o = NULL; sd_id128_t id = SD_ID128_NULL; const char *sid, *options = NULL; /* First one wins */ if (m->partitions[PARTITION_XBOOTLDR].found) continue; sid = blkid_partition_get_uuid(pp); if (sid) (void) sd_id128_from_string(sid, &id); n = strdup(node); if (!n) return -ENOMEM; options = mount_options_from_part(mount_options, nr); if (options) { o = strdup(options); if (!o) return -ENOMEM; } m->partitions[PARTITION_XBOOTLDR] = (DissectedPartition) { .found = true, .partno = nr, .rw = true, .architecture = _ARCHITECTURE_INVALID, .node = TAKE_PTR(n), .uuid = id, .mount_options = TAKE_PTR(o), }; break; }} } } 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) { _cleanup_free_ char *o = NULL; const char *options = NULL; /* If the root hash was set, then we won't fall back 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; options = mount_options_from_part(mount_options, generic_nr); if (options) { o = strdup(options); if (!o) return -ENOMEM; } m->partitions[PARTITION_ROOT] = (DissectedPartition) { .found = true, .rw = generic_rw, .partno = generic_nr, .architecture = _ARCHITECTURE_INVALID, .node = TAKE_PTR(generic_node), .uuid = generic_uuid, .mount_options = TAKE_PTR(o), }; } } 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->partitions[i].mount_options); } 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 run_fsck(const char *node, const char *fstype) { int r, exit_status; pid_t pid; assert(node); assert(fstype); r = fsck_exists(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.", node, fstype); return 0; } r = safe_fork("(fsck)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_NULL_STDIO, &pid); if (r < 0) return log_debug_errno(r, "Failed to fork off fsck: %m"); if (r == 0) { /* Child */ execl("/sbin/fsck", "/sbin/fsck", "-aT", node, NULL); 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 /sbin/fsck: %m"); if ((exit_status & ~FSCK_ERROR_CORRECTED) != FSCK_SUCCESS) { log_debug("fsck failed with exit status %i.", exit_status); if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0) return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), "File system is corrupted, refusing."); log_debug("Ignoring fsck error."); } return 0; } static int 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; /* 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_ptr(fstype, "crypto_LUKS")) return -EUNATCH; rw = m->rw && !(flags & DISSECT_IMAGE_READ_ONLY); if (FLAGS_SET(flags, DISSECT_IMAGE_FSCK) && rw) { r = run_fsck(node, fstype); if (r < 0) return r; } if (directory) { r = chase_symlinks(directory, where, CHASE_PREFIX_ROOT, &chased, NULL); 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; } if (!isempty(m->mount_options)) if (!strextend_with_separator(&options, ",", m->mount_options, NULL)) return -ENOMEM; if (FLAGS_SET(flags, DISSECT_IMAGE_MKDIR)) { r = mkdir_p(p, 0755); if (r < 0) return r; } r = mount_verbose(LOG_DEBUG, node, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options); if (r < 0) return r; return 1; } int dissected_image_mount(DissectedImage *m, const char *where, uid_t uid_shift, DissectImageFlags flags) { int r, boot_mounted; assert(m); assert(where); /* Returns: * * -ENXIO → No root partition found * -EMEDIUMTYPE → DISSECT_IMAGE_VALIDATE_OS set but no os-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) */ 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; /* Mask DISSECT_IMAGE_MKDIR for all subdirs: the idea is that only the top-level mount point is * created if needed, but the image itself not modified. */ flags &= ~DISSECT_IMAGE_MKDIR; 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; r = mount_partition(m->partitions + PARTITION_VAR, where, "/var", uid_shift, flags); if (r < 0) return r; r = mount_partition(m->partitions + PARTITION_TMP, where, "/var/tmp", uid_shift, flags); if (r < 0) return r; boot_mounted = mount_partition(m->partitions + PARTITION_XBOOTLDR, where, "/boot", uid_shift, flags); if (boot_mounted < 0) return boot_mounted; if (m->partitions[PARTITION_ESP].found) { /* 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) { r = mount_partition(m->partitions + PARTITION_ESP, where, "/efi", uid_shift, flags); if (r < 0) return r; } else if (boot_mounted <= 0) { _cleanup_free_ char *p = NULL; r = chase_symlinks("/boot", where, CHASE_PREFIX_ROOT, &p, NULL); if (r >= 0 && dir_is_empty(p) > 0) { r = mount_partition(m->partitions + PARTITION_ESP, where, "/boot", uid_shift, flags); if (r < 0) return r; } } } return 0; } int dissected_image_mount_and_warn(DissectedImage *m, const char *where, uid_t uid_shift, DissectImageFlags flags) { int r; assert(m); assert(where); r = dissected_image_mount(m, where, uid_shift, 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 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 < 0) return log_error_errno(r, "Failed to mount image: %m"); return r; } #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) 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(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"); cryptsetup_enable_logging(cd); 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_can_reuse(const void *root_hash, size_t root_hash_size, bool has_sig, 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_(crypt_freep) struct crypt_device *cd = NULL; struct crypt_params_verity crypt_params = {}; size_t root_hash_existing_size = root_hash_size; int r; assert(ret_cd); r = crypt_init_by_name(&cd, name); if (r < 0) return log_debug_errno(r, "Error opening verity device, crypt_init_by_name failed: %m"); r = 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 = malloc0(root_hash_size); if (!root_hash_existing) return -ENOMEM; r = 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 (root_hash_size != root_hash_existing_size || memcmp(root_hash_existing, root_hash, 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 viceversa. */ if (has_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 void dm_deferred_remove_clean(char *name) { if (!name) return; (void) crypt_deactivate_by_name(NULL, name, CRYPT_DEACTIVATE_DEFERRED); free(name); } DEFINE_TRIVIAL_CLEANUP_FUNC(char *, dm_deferred_remove_clean); static int verity_partition( DissectedPartition *m, DissectedPartition *v, const void *root_hash, size_t root_hash_size, const char *verity_data, const char *root_hash_sig_path, const void *root_hash_sig, size_t root_hash_sig_size, DissectImageFlags flags, DecryptedImage *d) { _cleanup_free_ char *node = NULL, *name = NULL, *hash_sig_from_file = NULL; _cleanup_(crypt_freep) struct crypt_device *cd = NULL; _cleanup_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL; int r; assert(m); assert(v || verity_data); if (!root_hash) return 0; if (!m->found || !m->node || !m->fstype) return 0; if (!verity_data) { if (!v->found || !v->node || !v->fstype) return 0; if (!streq(v->fstype, "DM_verity_hash")) return 0; } 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(root_hash, 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; if (!root_hash_sig && root_hash_sig_path) { r = read_full_file_full(AT_FDCWD, root_hash_sig_path, 0, &hash_sig_from_file, &root_hash_sig_size); if (r < 0) return r; } r = crypt_init(&cd, verity_data ?: v->node); if (r < 0) return r; cryptsetup_enable_logging(cd); 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; if (!GREEDY_REALLOC0(d->decrypted, d->n_allocated, 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++) { if (root_hash_sig || hash_sig_from_file) { #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY r = crypt_activate_by_signed_key(cd, name, root_hash, root_hash_size, root_hash_sig ?: hash_sig_from_file, root_hash_sig_size, CRYPT_ACTIVATE_READONLY); #else r = log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "activation of verity device with signature requested, but not supported by cryptsetup due to missing crypt_activate_by_signed_key()"); #endif } else r = crypt_activate_by_volume_key(cd, name, root_hash, root_hash_size, CRYPT_ACTIVATE_READONLY); /* 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)) return verity_partition(m, v, root_hash, root_hash_size, verity_data, NULL, root_hash_sig ?: hash_sig_from_file, root_hash_sig_size, flags & ~DISSECT_IMAGE_VERITY_SHARE, d); if (!IN_SET(r, 0, /* Success */ -EEXIST, /* Volume is already open and ready to be used */ -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 */)) return r; if (IN_SET(r, -EEXIST, -EBUSY)) { struct crypt_device *existing_cd = NULL; 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); /* If activation returns EBUSY there might be no deferred removal to cancel, that's fine */ if (r < 0 && r != -ENXIO) return log_debug_errno(r, "Disabling automated deferred removal for verity device %s failed: %m", node); if (r == 0) { restore_deferred_remove = strdup(name); if (!restore_deferred_remove) return -ENOMEM; } } r = verity_can_reuse(root_hash, root_hash_size, !!root_hash_sig || !!hash_sig_from_file, 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)) return verity_partition(m, v, root_hash, root_hash_size, verity_data, NULL, root_hash_sig ?: hash_sig_from_file, root_hash_sig_size, flags & ~DISSECT_IMAGE_VERITY_SHARE, d); if (!IN_SET(r, 0, -ENODEV, -ENOENT, -EBUSY)) return log_debug_errno(r, "Checking whether existing verity device %s can be reused failed: %m", node); if (r == 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", 100 * USEC_PER_MSEC, NULL); /* Fallback to activation with a unique device if it's taking too long */ if (r == -ETIMEDOUT) break; if (r < 0) return r; if (cd) crypt_free(cd); cd = existing_cd; } } if (r == 0) break; /* Device is being opened by another process, but it has not finished yet, yield for 2ms */ (void) usleep(2 * USEC_PER_MSEC); } /* An existing verity device was reported by libcryptsetup/libdevmapper, but we can't use it at this time. * Fall back to activating it with a unique device name. */ if (r != 0 && FLAGS_SET(flags, DISSECT_IMAGE_VERITY_SHARE)) return verity_partition(m, v, root_hash, root_hash_size, verity_data, NULL, root_hash_sig ?: hash_sig_from_file, root_hash_sig_size, flags & ~DISSECT_IMAGE_VERITY_SHARE, d); /* 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].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, const char *verity_data, const char *root_hash_sig_path, const void *root_hash_sig, size_t root_hash_sig_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, verity_data, root_hash_sig_path, root_hash_sig, root_hash_sig_size, flags | DISSECT_IMAGE_VERITY_SHARE, 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, const char *verity_data, const char *root_hash_sig_path, const void *root_hash_sig, size_t root_hash_sig_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, verity_data, root_hash_sig_path, root_hash_sig, root_hash_sig_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]; } } 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 = 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 verity_metadata_load( const char *image, const char *root_hash_path, void **ret_roothash, size_t *ret_roothash_size, char **ret_verity_data, char **ret_roothashsig) { _cleanup_free_ char *verity_filename = NULL, *roothashsig_filename = NULL; _cleanup_free_ void *roothash_decoded = NULL; size_t roothash_decoded_size = 0; int r; assert(image); if (is_device_path(image)) { /* If we are asked to load the root hash for a device node, exit early */ if (ret_roothash) *ret_roothash = NULL; if (ret_roothash_size) *ret_roothash_size = 0; if (ret_verity_data) *ret_verity_data = NULL; if (ret_roothashsig) *ret_roothashsig = NULL; return 0; } if (ret_verity_data) { char *e; verity_filename = new(char, strlen(image) + STRLEN(".verity") + 1); if (!verity_filename) return -ENOMEM; strcpy(verity_filename, image); e = endswith(verity_filename, ".raw"); if (e) strcpy(e, ".verity"); else strcat(verity_filename, ".verity"); r = access(verity_filename, F_OK); if (r < 0) { if (errno != ENOENT) return -errno; verity_filename = mfree(verity_filename); } } if (ret_roothashsig) { char *e; /* Follow naming convention recommended by the relevant RFC: * https://tools.ietf.org/html/rfc5751#section-3.2.1 */ roothashsig_filename = new(char, strlen(image) + STRLEN(".roothash.p7s") + 1); if (!roothashsig_filename) return -ENOMEM; strcpy(roothashsig_filename, image); e = endswith(roothashsig_filename, ".raw"); if (e) strcpy(e, ".roothash.p7s"); else strcat(roothashsig_filename, ".roothash.p7s"); r = access(roothashsig_filename, R_OK); if (r < 0) { if (errno != ENOENT) return -errno; roothashsig_filename = mfree(roothashsig_filename); } } if (ret_roothash) { _cleanup_free_ char *text = NULL; assert(ret_roothash_size); if (root_hash_path) { /* We have the path to a roothash to load and decode, eg: RootHash=/foo/bar.roothash */ r = read_one_line_file(root_hash_path, &text); if (r < 0) return r; } else { 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 < 0 && r != -ENOENT) return r; } } if (text) { r = unhexmem(text, strlen(text), &roothash_decoded, &roothash_decoded_size); if (r < 0) return r; if (roothash_decoded_size < sizeof(sd_id128_t)) return -EINVAL; } } if (ret_roothash) { *ret_roothash = TAKE_PTR(roothash_decoded); *ret_roothash_size = roothash_decoded_size; } if (ret_verity_data) *ret_verity_data = TAKE_PTR(verity_filename); if (roothashsig_filename) *ret_roothashsig = TAKE_PTR(roothashsig_filename); 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_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, k; int fds[2 * _META_MAX], r, v; ssize_t n; 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; 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) { error_pipe[0] = safe_close(error_pipe[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) { /* Let parent know the error */ (void) write(error_pipe[1], &r, sizeof(r)); log_debug_errno(r, "Failed to mount dissected image: %m"); _exit(EXIT_FAILURE); } for (k = 0; k < _META_MAX; k++) { _cleanup_close_ int fd = -ENOENT; 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]); fds[2*k+1] = safe_close(fds[2*k+1]); continue; } r = copy_bytes(fd, fds[2*k+1], (uint64_t) -1, 0); if (r < 0) { (void) write(error_pipe[1], &r, sizeof(r)); _exit(EXIT_FAILURE); } fds[2*k+1] = safe_close(fds[2*k+1]); } _exit(EXIT_SUCCESS); } error_pipe[1] = safe_close(error_pipe[1]); for (k = 0; k < _META_MAX; k++) { _cleanup_fclose_ FILE *f = NULL; 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: %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) return r; n = read(error_pipe[0], &v, sizeof(v)); if (n < 0) return -errno; if (n == sizeof(v)) return v; /* propagate error sent to us from child */ if (n != 0) return -EIO; 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, const char *verity_data, const MountOptions *mount_options, 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, verity_data, 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, "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; } } bool dissected_image_can_do_verity(const DissectedImage *image, unsigned partition_designator) { if (image->single_file_system) return partition_designator == PARTITION_ROOT && image->can_verity; return PARTITION_VERITY_OF(partition_designator) >= 0; } bool dissected_image_has_verity(const DissectedImage *image, unsigned partition_designator) { int k; if (image->single_file_system) return partition_designator == PARTITION_ROOT && image->verity; k = PARTITION_VERITY_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_part(const MountOptions *options, unsigned int partition_number) { MountOptions *m; LIST_FOREACH(mount_options, m, (MountOptions *)options) if (partition_number == m->partition_number && !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, DecryptedImage **ret_decrypted_image) { _cleanup_(loop_device_unrefp) LoopDevice *d = NULL; _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = 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); assert(ret_decrypted_image); 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_READ_ONLY) ? O_RDONLY : O_RDWR, FLAGS_SET(flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN, &d); if (r < 0) return log_error_errno(r, "Failed to set up loopback device: %m"); r = dissect_image_and_warn(d->fd, image, NULL, 0, NULL, NULL, flags, &dissected_image); if (r < 0) return r; r = dissected_image_decrypt_interactively(dissected_image, NULL, NULL, 0, NULL, NULL, NULL, 0, flags, &decrypted_image); 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, flags); if (r < 0) return r; if (decrypted_image) { r = decrypted_image_relinquish(decrypted_image); if (r < 0) return log_error_errno(r, "Failed to relinquish DM devices: %m"); } loop_device_relinquish(d); *ret_directory = TAKE_PTR(created_dir); *ret_loop_device = TAKE_PTR(d); *ret_decrypted_image = TAKE_PTR(decrypted_image); return 0; } 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_XBOOTLDR] = "xbootldr", [PARTITION_SWAP] = "swap", [PARTITION_ROOT_VERITY] = "root-verity", [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity", [PARTITION_TMP] = "tmp", [PARTITION_VAR] = "var", }; DEFINE_STRING_TABLE_LOOKUP(partition_designator, int);