/* SPDX-License-Identifier: LGPL-2.1-or-later */ #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 "cryptsetup-util.h" #include "def.h" #include "device-nodes.h" #include "device-util.h" #include "discover-image.h" #include "dissect-image.h" #include "dm-util.h" #include "env-file.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 "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 "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(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 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_add_match_subsystem(e, "block", true); if (r < 0) return r; r = sd_device_enumerator_add_match_parent(e, d); if (r < 0) return r; r = sd_device_enumerator_add_match_sysattr(e, "partition", NULL, true); if (r < 0) return r; *ret = TAKE_PTR(e); return 0; } static int device_is_partition( sd_device *d, sd_device *expected_parent, blkid_partition pp) { const char *v, *parent_syspath, *expected_parent_syspath; blkid_loff_t bsize, bstart; uint64_t size, start; int partno, bpartno, r; sd_device *parent; assert(d); assert(expected_parent); assert(pp); r = sd_device_get_subsystem(d, &v); if (r < 0) return r; if (!streq(v, "block")) return false; if (sd_device_get_devtype(d, &v) < 0 || !streq(v, "partition")) return false; r = sd_device_get_parent(d, &parent); if (r < 0) return false; /* Doesn't have a parent? No relevant to us */ r = sd_device_get_syspath(parent, &parent_syspath); /* Check parent of device of this action */ if (r < 0) return r; r = sd_device_get_syspath(expected_parent, &expected_parent_syspath); /* Check parent of device we are looking for */ if (r < 0) return r; if (!path_equal(parent_syspath, expected_parent_syspath)) return false; /* Has a different parent than what we need, not interesting to us */ /* On kernel uevents we may find the partition number in the PARTN= field. Let's use that preferably, * since it's cheaper and more importantly: the sysfs attribute "partition" appears to become * available late, hence let's use the property instead, which is available at the moment we see the * uevent. */ r = sd_device_get_property_value(d, "PARTN", &v); if (r == -ENOENT) r = sd_device_get_sysattr_value(d, "partition", &v); if (r < 0) return r; r = safe_atoi(v, &partno); if (r < 0) return r; errno = 0; bpartno = blkid_partition_get_partno(pp); if (bpartno < 0) return errno_or_else(EIO); if (partno != bpartno) return false; r = sd_device_get_sysattr_value(d, "start", &v); if (r < 0) return r; r = safe_atou64(v, &start); if (r < 0) return r; errno = 0; bstart = blkid_partition_get_start(pp); if (bstart < 0) return errno_or_else(EIO); if (start != (uint64_t) bstart) return false; r = sd_device_get_sysattr_value(d, "size", &v); if (r < 0) return r; r = safe_atou64(v, &size); if (r < 0) return r; errno = 0; bsize = blkid_partition_get_size(pp); if (bsize < 0) return errno_or_else(EIO); if (size != (uint64_t) bsize) return false; return true; } static int find_partition( sd_device *parent, blkid_partition pp, usec_t timestamp_not_before, sd_device **ret) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; sd_device *q; int r; assert(parent); assert(pp); assert(ret); r = enumerator_for_parent(parent, &e); if (r < 0) return r; FOREACH_DEVICE(e, q) { uint64_t usec; r = sd_device_get_usec_initialized(q, &usec); if (r == -EBUSY) /* Not initialized yet */ continue; if (r < 0) return r; if (timestamp_not_before != USEC_INFINITY && usec < timestamp_not_before) /* udev database entry older than our attachment? Then it's not ours */ continue; r = device_is_partition(q, parent, pp); if (r < 0) return r; if (r > 0) { *ret = sd_device_ref(q); return 0; } } return -ENXIO; } struct wait_data { sd_device *parent_device; blkid_partition blkidp; sd_device *found; uint64_t uevent_seqnum_not_before; }; static inline void wait_data_done(struct wait_data *d) { sd_device_unref(d->found); } static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) { struct wait_data *w = userdata; int r; assert(w); if (device_for_action(device, SD_DEVICE_REMOVE)) return 0; if (w->uevent_seqnum_not_before != UINT64_MAX) { uint64_t seqnum; r = sd_device_get_seqnum(device, &seqnum); if (r < 0) goto finish; if (seqnum <= w->uevent_seqnum_not_before) { /* From an older use of this loop device */ log_debug("Dropping event because seqnum too old (%" PRIu64 " <= %" PRIu64 ")", seqnum, w->uevent_seqnum_not_before); return 0; } } r = device_is_partition(device, w->parent_device, w->blkidp); if (r < 0) goto finish; if (r == 0) /* Not the one we need */ return 0; /* It's the one we need! Yay! */ assert(!w->found); w->found = sd_device_ref(device); r = 0; finish: return sd_event_exit(sd_device_monitor_get_event(monitor), r); } static int wait_for_partition_device( sd_device *parent, blkid_partition pp, usec_t deadline, uint64_t uevent_seqnum_not_before, usec_t timestamp_not_before, sd_device **ret) { _cleanup_(sd_event_source_unrefp) sd_event_source *timeout_source = NULL; _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL; _cleanup_(sd_event_unrefp) sd_event *event = NULL; int r; assert(parent); assert(pp); assert(ret); r = find_partition(parent, pp, timestamp_not_before, ret); if (r != -ENXIO) return r; r = sd_event_new(&event); if (r < 0) return r; r = sd_device_monitor_new(&monitor); if (r < 0) return r; r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, "block", "partition"); if (r < 0) return r; r = sd_device_monitor_filter_add_match_parent(monitor, parent, true); if (r < 0) return r; r = sd_device_monitor_filter_add_match_sysattr(monitor, "partition", NULL, true); if (r < 0) return r; r = sd_device_monitor_attach_event(monitor, event); if (r < 0) return r; _cleanup_(wait_data_done) struct wait_data w = { .parent_device = parent, .blkidp = pp, .uevent_seqnum_not_before = uevent_seqnum_not_before, }; r = sd_device_monitor_start(monitor, device_monitor_handler, &w); if (r < 0) return r; /* Check again, the partition might have appeared in the meantime */ r = find_partition(parent, pp, timestamp_not_before, ret); if (r != -ENXIO) return r; if (deadline != USEC_INFINITY) { r = sd_event_add_time( event, &timeout_source, CLOCK_MONOTONIC, deadline, 0, NULL, INT_TO_PTR(-ETIMEDOUT)); if (r < 0) return r; } r = sd_event_loop(event); if (r < 0) return r; assert(w.found); *ret = TAKE_PTR(w.found); 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 | 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); } } static int device_wait_for_initialization_harder( sd_device *device, const char *subsystem, usec_t deadline, sd_device **ret) { usec_t start, left, retrigger_timeout; int r; start = now(CLOCK_MONOTONIC); left = usec_sub_unsigned(deadline, start); if (DEBUG_LOGGING) { char buf[FORMAT_TIMESPAN_MAX]; const char *sn = NULL; (void) sd_device_get_sysname(device, &sn); log_device_debug(device, "Waiting for device '%s' to initialize for %s.", strna(sn), format_timespan(buf, sizeof(buf), left, 0)); } if (left != USEC_INFINITY) retrigger_timeout = CLAMP(left / 4, 1 * USEC_PER_SEC, 5 * USEC_PER_SEC); /* A fourth of the total timeout, but let's clamp to 1s…5s range */ else retrigger_timeout = 2 * USEC_PER_SEC; for (;;) { usec_t local_deadline, n; bool last_try; n = now(CLOCK_MONOTONIC); assert(n >= start); /* Find next deadline, when we'll retrigger */ local_deadline = start + DIV_ROUND_UP(n - start, retrigger_timeout) * retrigger_timeout; if (deadline != USEC_INFINITY && deadline <= local_deadline) { local_deadline = deadline; last_try = true; } else last_try = false; r = device_wait_for_initialization(device, subsystem, local_deadline, ret); if (r >= 0 && DEBUG_LOGGING) { char buf[FORMAT_TIMESPAN_MAX]; const char *sn = NULL; (void) sd_device_get_sysname(device, &sn); log_device_debug(device, "Successfully waited for device '%s' to initialize for %s.", strna(sn), format_timespan(buf, sizeof(buf), usec_sub_unsigned(now(CLOCK_MONOTONIC), start), 0)); } if (r != -ETIMEDOUT || last_try) return r; if (DEBUG_LOGGING) { char buf[FORMAT_TIMESPAN_MAX]; log_device_debug(device, "Device didn't initialize within %s, assuming lost event. Retriggering device.", format_timespan(buf, sizeof(buf), usec_sub_unsigned(now(CLOCK_MONOTONIC), start), 0)); } r = sd_device_trigger(device, SD_DEVICE_CHANGE); if (r < 0) return r; } } #endif #define DEVICE_TIMEOUT_USEC (45 * USEC_PER_SEC) 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); *p = (DissectedPartition) { .partno = -1, .architecture = -1 }; } int dissect_image( int fd, const VeritySettings *verity, const MountOptions *mount_options, uint64_t uevent_seqnum_not_before, usec_t timestamp_not_before, DissectImageFlags flags, DissectedImage **ret) { #if HAVE_BLKID #ifdef GPT_ROOT_NATIVE sd_id128_t root_uuid = SD_ID128_NULL, root_verity_uuid = SD_ID128_NULL; #endif #ifdef GPT_USR_NATIVE sd_id128_t usr_uuid = SD_ID128_NULL, usr_verity_uuid = SD_ID128_NULL; #endif bool is_gpt, is_mbr, multiple_generic = false, generic_rw = false, /* initialize to appease gcc */ generic_growfs = 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, *sysname = NULL; blkid_partlist pl; int r, generic_nr = -1, n_partitions; struct stat st; usec_t deadline; assert(fd >= 0); assert(ret); assert(!verity || verity->root_hash || verity->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. * 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. */ #ifdef GPT_USR_NATIVE if (verity->designator == PARTITION_USR) { usr_uuid = fsuuid; usr_verity_uuid = vuuid; } else { #endif #ifdef GPT_ROOT_NATIVE root_uuid = fsuuid; root_verity_uuid = vuuid; #endif #ifdef GPT_USR_NATIVE } #endif } if (fstat(fd, &st) < 0) return -errno; if (!S_ISBLK(st.st_mode)) return -ENOTBLK; r = sd_device_new_from_stat_rdev(&d, &st); if (r < 0) return r; if (!FLAGS_SET(flags, DISSECT_IMAGE_NO_UDEV)) { _cleanup_(sd_device_unrefp) sd_device *initialized = NULL; /* If udev support is enabled, then let's wait for the device to be initialized before we doing anything. */ r = device_wait_for_initialization_harder( d, "block", usec_add(now(CLOCK_MONOTONIC), DEVICE_TIMEOUT_USEC), &initialized); if (r < 0) return r; sd_device_unref(d); d = TAKE_PTR(initialized); } 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_get_sysname(d, &sysname); if (r < 0) return log_debug_errno(r, "Failed to get device sysname: %m"); if (startswith(sysname, "loop")) { _cleanup_free_ char *name_stripped = NULL; const char *full_path; r = sd_device_get_sysattr_value(d, "loop/backing_file", &full_path); if (r < 0) log_debug_errno(r, "Failed to lookup image name via loop device backing file sysattr, ignoring: %m"); else { r = raw_strip_suffixes(basename(full_path), &name_stripped); if (r < 0) return r; } free_and_replace(m->image_name, name_stripped); } else { r = free_and_strdup(&m->image_name, sysname); if (r < 0) return r; } if (!image_name_is_valid(m->image_name)) { log_debug("Image name %s is not valid, ignoring", strempty(m->image_name)); m->image_name = mfree(m->image_name); } 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")) { const char *fstype = NULL, *options = NULL, *devname = NULL; _cleanup_free_ char *t = NULL, *n = NULL, *o = 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 = sd_device_get_devname(d, &devname); if (r < 0) return r; n = strdup(devname); if (!n) return -ENOMEM; m->single_file_system = true; m->verity = verity && verity->root_hash && verity->data_path && (verity->designator < 0 || verity->designator == PARTITION_ROOT); m->can_verity = verity && verity->data_path; 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, .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"); *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; /* 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); deadline = usec_add(now(CLOCK_MONOTONIC), DEVICE_TIMEOUT_USEC); for (int i = 0; i < n_partitions; i++) { _cleanup_(sd_device_unrefp) sd_device *q = NULL; unsigned long long pflags; blkid_partition pp; const char *node; int nr; errno = 0; pp = blkid_partlist_get_partition(pl, i); if (!pp) return errno_or_else(EIO); r = wait_for_partition_device(d, pp, deadline, uevent_seqnum_not_before, timestamp_not_before, &q); if (r < 0) return r; r = sd_device_get_devname(q, &node); if (r < 0) return r; pflags = blkid_partition_get_flags(pp); errno = 0; nr = blkid_partition_get_partno(pp); if (nr < 0) return errno_or_else(EIO); if (is_gpt) { PartitionDesignator designator = _PARTITION_DESIGNATOR_INVALID; int 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, GPT_HOME)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY|GPT_FLAG_GROWFS); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_HOME; rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } else if (sd_id128_equal(type_id, GPT_SRV)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY|GPT_FLAG_GROWFS); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_SRV; rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } 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|GPT_FLAG_GROWFS); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_XBOOTLDR; rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } #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|GPT_FLAG_GROWFS); 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); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } 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(root_verity_uuid) || !sd_id128_equal(root_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|GPT_FLAG_GROWFS); 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); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } 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(root_verity_uuid) || !sd_id128_equal(root_verity_uuid, id)) continue; designator = PARTITION_ROOT_SECONDARY_VERITY; fstype = "DM_verity_hash"; architecture = SECONDARY_ARCHITECTURE; rw = false; } #endif #ifdef GPT_USR_NATIVE else if (sd_id128_equal(type_id, GPT_USR_NATIVE)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY|GPT_FLAG_GROWFS); if (pflags & 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; designator = PARTITION_USR; architecture = native_architecture(); rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } else if (sd_id128_equal(type_id, GPT_USR_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 usr hash is specified */ if (sd_id128_is_null(usr_verity_uuid) || !sd_id128_equal(usr_verity_uuid, id)) continue; designator = PARTITION_USR_VERITY; fstype = "DM_verity_hash"; architecture = native_architecture(); rw = false; } #endif #ifdef GPT_USR_SECONDARY else if (sd_id128_equal(type_id, GPT_USR_SECONDARY)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY|GPT_FLAG_GROWFS); if (pflags & 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; designator = PARTITION_USR_SECONDARY; architecture = SECONDARY_ARCHITECTURE; rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } else if (sd_id128_equal(type_id, GPT_USR_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 usr has is specified */ if (sd_id128_is_null(usr_verity_uuid) || !sd_id128_equal(usr_verity_uuid, id)) continue; designator = PARTITION_USR_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|GPT_FLAG_GROWFS); 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_growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); 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|GPT_FLAG_GROWFS); if (pflags & GPT_FLAG_NO_AUTO) continue; designator = PARTITION_TMP; rw = !(pflags & GPT_FLAG_READ_ONLY); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } else if (sd_id128_equal(type_id, GPT_VAR)) { check_partition_flags(node, pflags, GPT_FLAG_NO_AUTO|GPT_FLAG_READ_ONLY|GPT_FLAG_GROWFS); 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); growfs = FLAGS_SET(pflags, GPT_FLAG_GROWFS); } if (designator != _PARTITION_DESIGNATOR_INVALID) { _cleanup_free_ char *t = NULL, *n = NULL, *o = NULL, *l = NULL; 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 (fstype) { t = strdup(fstype); if (!t) return -ENOMEM; } n = strdup(node); if (!n) 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(n), .fstype = TAKE_PTR(t), .label = TAKE_PTR(l), .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_growfs = false; 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_designator(mount_options, PARTITION_XBOOTLDR); if (options) { o = strdup(options); if (!o) return -ENOMEM; } m->partitions[PARTITION_XBOOTLDR] = (DissectedPartition) { .found = true, .partno = nr, .rw = true, .growfs = false, .architecture = _ARCHITECTURE_INVALID, .node = TAKE_PTR(n), .uuid = id, .mount_options = TAKE_PTR(o), }; break; }} } } if (m->partitions[PARTITION_ROOT].found) { /* If we found the primary arch, then invalidate the secondary arch to avoid any ambiguities, * since we never want to mount the secondary arch in this case. */ m->partitions[PARTITION_ROOT_SECONDARY].found = false; m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found = false; m->partitions[PARTITION_USR_SECONDARY].found = false; m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false; } else if (m->partitions[PARTITION_ROOT_VERITY].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 */ 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]); m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_SECONDARY]; zero(m->partitions[PARTITION_USR_SECONDARY]); m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_SECONDARY_VERITY]; zero(m->partitions[PARTITION_USR_SECONDARY_VERITY]); } else if (m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found) return -EADDRNOTAVAIL; /* as above */ else if (m->partitions[PARTITION_USR].found) { /* Invalidate secondary arch /usr/ if we found the primary arch */ m->partitions[PARTITION_USR_SECONDARY].found = false; m->partitions[PARTITION_USR_SECONDARY_VERITY].found = false; } else if (m->partitions[PARTITION_USR_VERITY].found) return -EADDRNOTAVAIL; /* as above */ else if (m->partitions[PARTITION_USR_SECONDARY].found) { /* Upgrade secondary arch to primary */ m->partitions[PARTITION_USR] = m->partitions[PARTITION_USR_SECONDARY]; zero(m->partitions[PARTITION_USR_SECONDARY]); m->partitions[PARTITION_USR_VERITY] = m->partitions[PARTITION_USR_SECONDARY_VERITY]; zero(m->partitions[PARTITION_USR_SECONDARY_VERITY]); } else if (m->partitions[PARTITION_USR_SECONDARY_VERITY].found) return -EADDRNOTAVAIL; /* as above */ else if ((flags & DISSECT_IMAGE_GENERIC_ROOT) && (!verity || !verity->root_hash)) { /* OK, we found nothing usable, then check if there's a single generic one distro, 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_free_ char *o = NULL; const char *options; 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), }; } } /* 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; /* Refuse if we found a verity partition for /usr but no matching file system partition */ if (!m->partitions[PARTITION_USR].found && m->partitions[PARTITION_USR_VERITY].found) return -EADDRNOTAVAIL; /* Combinations of verity /usr with verity-less root is OK, but the reverse is not */ if (m->partitions[PARTITION_ROOT_VERITY].found && m->partitions[PARTITION_USR].found && !m->partitions[PARTITION_USR_VERITY].found) return -EADDRNOTAVAIL; if (verity && verity->root_hash) { 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 = true; } if (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 = true; } } blkid_free_probe(b); b = NULL; /* 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 && 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; if (!p->rw) p->growfs = false; } *ret = TAKE_PTR(m); return 0; #else return -EOPNOTSUPP; #endif } DissectedImage* dissected_image_unref(DissectedImage *m) { if (!m) return NULL; for (PartitionDesignator i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) dissected_partition_done(m->partitions + i); 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(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_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 /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 fs_grow(const char *node_path, const char *mount_path) { _cleanup_close_ int mount_fd = -1, node_fd = -1; char fb[FORMAT_BYTES_MAX]; 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(fb, sizeof fb, newsize)); else { assert(newsize < size); log_debug("Successfully resized \"%s\" to %s bytes (%"PRIu64" bytes lost due to blocksize).", mount_path, format_bytes(fb, sizeof fb, 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); /* Use decrypted node and matching fstype if available, otherwise use the original device */ node = m->decrypted_node ?: m->node; fstype = m->decrypted_node ? m->decrypted_fstype: m->fstype; if (!m->found || !node) return 0; 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(node, 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); 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) { r = path_is_os_tree(where); if (r < 0) return r; if (r == 0) { r = path_is_extension_tree(where, m->image_name); 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, 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) > 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 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 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) { r = sym_crypt_deactivate_by_name(p->device, p->name, 0); 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; } #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(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; 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_allocated, 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; } d->decrypted[d->n_decrypted++] = (DecryptedPartition) { .name = TAKE_PTR(name), .device = TAKE_PTR(cd), }; m->decrypted_node = TAKE_PTR(node); 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"); 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 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; 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_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 (verity->root_hash_sig) { #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY 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); #else r = log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Activation of verity device with signature requested, but not supported by %s due to missing crypt_activate_by_signed_key().", program_invocation_short_name); #endif } else r = sym_crypt_activate_by_volume_key( cd, name, verity->root_hash, verity->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(designator, m, v, verity, 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(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)) return verity_partition(designator, m, v, verity, 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", usec_add(now(CLOCK_MONOTONIC), 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) sym_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(designator, m, v, verity, 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++] = (DecryptedPartition) { .name = TAKE_PTR(name), .device = TAKE_PTR(cd), }; m->decrypted_node = TAKE_PTR(node); return 0; } #endif int dissected_image_decrypt( DissectedImage *m, const char *passphrase, const VeritySettings *verity, DissectImageFlags flags, DecryptedImage **ret) { #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) { *ret = NULL; return 0; } #if HAVE_LIBCRYPTSETUP d = new0(DecryptedImage, 1); if (!d) return -ENOMEM; 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->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 VeritySettings *verity, 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, verity, 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", "dissect.passphrase", 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) { 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; } 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; 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, true); if (r < 0) { _cleanup_free_ char *p = NULL; if (!IN_SET(r, -ENODATA, -ENOENT) && !ERRNO_IS_NOT_SUPPORTED(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, true); if (r < 0) { _cleanup_free_ char *p = NULL; if (!IN_SET(r, -ENODATA, -ENOENT) && !ERRNO_IS_NOT_SUPPORTED(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_acquire_metadata(DissectedImage *m) { enum { META_HOSTNAME, META_MACHINE_ID, META_MACHINE_INFO, META_OS_RELEASE, META_EXTENSION_RELEASE, _META_MAX, }; static const char *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] = NULL, }; _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; ssize_t n; BLOCK_SIGNALS(SIGCHLD); assert(m); /* 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/ */ if (m->image_name) { char *ext; ext = strjoina("/usr/lib/extension-release.d/extension-release.", m->image_name, "0"); ext[strlen(ext) - 1] = '\0'; /* Extra \0 for NULSTR_FOREACH using placeholder from above */ paths[META_EXTENSION_RELEASE] = ext; } else log_debug("No image name available, will skip extension-release metadata"); 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) { error_pipe[0] = safe_close(error_pipe[0]); r = dissected_image_mount( m, t, UID_INVALID, UID_INVALID, DISSECT_IMAGE_READ_ONLY| DISSECT_IMAGE_MOUNT_ROOT_ONLY| DISSECT_IMAGE_VALIDATE_OS| DISSECT_IMAGE_USR_NO_ROOT); 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 (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]); 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_MAX, 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 (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: %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 if (streq(line, "uninitialized")) log_debug("/etc/machine-id file is uninitialized (likely aborted first boot)."); 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; 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: %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); strv_free_and_replace(m->extension_release, extension_release); finish: for (unsigned 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 VeritySettings *verity, const MountOptions *mount_options, uint64_t uevent_seqnum_not_before, usec_t timestamp_not_before, 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, verity, mount_options, uevent_seqnum_not_before, timestamp_not_before, 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, PartitionDesignator 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, PartitionDesignator 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_designator(const MountOptions *options, PartitionDesignator designator) { const MountOptions *m; 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, DecryptedImage **ret_decrypted_image) { _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT; _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 = 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, &d); if (r < 0) return log_error_errno(r, "Failed to set up loopback device for %s: %m", image); r = dissect_image_and_warn(d->fd, image, &verity, NULL, d->uevent_seqnum_not_before, d->timestamp_not_before, flags, &dissected_image); if (r < 0) return r; r = dissected_image_decrypt_interactively(dissected_image, NULL, &verity, 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, 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_USR] = "usr", [PARTITION_USR_SECONDARY] = "usr-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_USR_VERITY] = "usr-verity", [PARTITION_USR_SECONDARY_VERITY] = "usr-secondary-verity", [PARTITION_TMP] = "tmp", [PARTITION_VAR] = "var", }; int verity_dissect_and_mount( 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) { _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL; _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL; _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL; _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT; DissectImageFlags dissect_image_flags; int r; assert(src); assert(dest); 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; r = loop_device_make_by_path( src, -1, verity.data_path ? 0 : LO_FLAGS_PARTSCAN, &loop_device); if (r < 0) return log_debug_errno(r, "Failed to create loop device for image: %m"); r = dissect_image( loop_device->fd, &verity, options, loop_device->uevent_seqnum_not_before, loop_device->timestamp_not_before, dissect_image_flags, &dissected_image); /* No partition table? Might be a single-filesystem image, try again */ if (!verity.data_path && r == -ENOPKG) r = dissect_image( loop_device->fd, &verity, options, loop_device->uevent_seqnum_not_before, loop_device->timestamp_not_before, 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_decrypt( dissected_image, NULL, &verity, dissect_image_flags, &decrypted_image); 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"); /* 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 (required_host_os_release_id && (required_host_os_release_version_id || required_host_os_release_sysext_level)) { _cleanup_strv_free_ char **extension_release = NULL; r = load_extension_release_pairs(dest, dissected_image->image_name, &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, 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); } if (decrypted_image) { r = decrypted_image_relinquish(decrypted_image); if (r < 0) return log_debug_errno(r, "Failed to relinquish decrypted image: %m"); } loop_device_relinquish(loop_device); return 0; } DEFINE_STRING_TABLE_LOOKUP(partition_designator, PartitionDesignator);