/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #if HAVE_VALGRIND_MEMCHECK_H #include #endif #include "sd-daemon.h" #include "sd-device.h" #include "sd-event.h" #include "sd-id128.h" #include "blkid-util.h" #include "blockdev-util.h" #include "btrfs-util.h" #include "chattr-util.h" #include "device-util.h" #include "devnum-util.h" #include "dm-util.h" #include "env-util.h" #include "errno-util.h" #include "fd-util.h" #include "fdisk-util.h" #include "fileio.h" #include "filesystems.h" #include "fs-util.h" #include "fsck-util.h" #include "glyph-util.h" #include "gpt.h" #include "home-util.h" #include "homework-blob.h" #include "homework-luks.h" #include "homework-mount.h" #include "io-util.h" #include "json-util.h" #include "keyring-util.h" #include "memory-util.h" #include "missing_magic.h" #include "mkdir.h" #include "mkfs-util.h" #include "mount-util.h" #include "openssl-util.h" #include "parse-util.h" #include "path-util.h" #include "process-util.h" #include "random-util.h" #include "resize-fs.h" #include "strv.h" #include "sync-util.h" #include "tmpfile-util.h" #include "udev-util.h" #include "user-util.h" /* Round down to the nearest 4K size. Given that newer hardware generally prefers 4K sectors, let's align our * partitions to that too. In the worst case we'll waste 3.5K per partition that way, but I think I can live * with that. */ #define DISK_SIZE_ROUND_DOWN(x) ((x) & ~UINT64_C(4095)) /* Rounds up to the nearest 4K boundary. Returns UINT64_MAX on overflow */ #define DISK_SIZE_ROUND_UP(x) \ ({ \ uint64_t _x = (x); \ _x > UINT64_MAX - 4095U ? UINT64_MAX : (_x + 4095U) & ~UINT64_C(4095); \ }) /* How much larger will the image on disk be than the fs inside it, i.e. the space we pay for the GPT and * LUKS2 envelope. (As measured on cryptsetup 2.4.1) */ #define GPT_LUKS2_OVERHEAD UINT64_C(18874368) static int resize_image_loop(UserRecord *h, HomeSetup *setup, uint64_t old_image_size, uint64_t new_image_size, uint64_t *ret_image_size); int run_mark_dirty(int fd, bool b) { char x = '1'; int r, ret; /* Sets or removes the 'user.home-dirty' xattr on the specified file. We use this to detect when a * home directory was not properly unmounted. */ assert(fd >= 0); r = fd_verify_regular(fd); if (r < 0) return r; if (b) { ret = fsetxattr(fd, "user.home-dirty", &x, 1, XATTR_CREATE); if (ret < 0 && errno != EEXIST) return log_debug_errno(errno, "Could not mark home directory as dirty: %m"); } else { r = fsync_full(fd); if (r < 0) return log_debug_errno(r, "Failed to synchronize image before marking it clean: %m"); ret = fremovexattr(fd, "user.home-dirty"); if (ret < 0 && !ERRNO_IS_XATTR_ABSENT(errno)) return log_debug_errno(errno, "Could not mark home directory as clean: %m"); } r = fsync_full(fd); if (r < 0) return log_debug_errno(r, "Failed to synchronize dirty flag to disk: %m"); return ret >= 0; } int run_mark_dirty_by_path(const char *path, bool b) { _cleanup_close_ int fd = -EBADF; assert(path); fd = open(path, O_RDWR|O_CLOEXEC|O_NOCTTY); if (fd < 0) return log_debug_errno(errno, "Failed to open %s to mark dirty or clean: %m", path); return run_mark_dirty(fd, b); } static int probe_file_system_by_fd( int fd, char **ret_fstype, sd_id128_t *ret_uuid) { _cleanup_(blkid_free_probep) blkid_probe b = NULL; const char *fstype = NULL, *uuid = NULL; sd_id128_t id; int r; assert(fd >= 0); assert(ret_fstype); assert(ret_uuid); 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); (void) blkid_probe_enable_superblocks(b, 1); (void) blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE|BLKID_SUBLKS_UUID); errno = 0; r = blkid_do_safeprobe(b); if (r == _BLKID_SAFEPROBE_ERROR) return errno_or_else(EIO); if (IN_SET(r, _BLKID_SAFEPROBE_AMBIGUOUS, _BLKID_SAFEPROBE_NOT_FOUND)) return -ENOPKG; assert(r == _BLKID_SAFEPROBE_FOUND); (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); if (!fstype) return -ENOPKG; (void) blkid_probe_lookup_value(b, "UUID", &uuid, NULL); if (!uuid) return -ENOPKG; r = sd_id128_from_string(uuid, &id); if (r < 0) return r; r = strdup_to(ret_fstype, fstype); if (r < 0) return r; *ret_uuid = id; return 0; } static int probe_file_system_by_path(const char *path, char **ret_fstype, sd_id128_t *ret_uuid) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); if (fd < 0) return negative_errno(); return probe_file_system_by_fd(fd, ret_fstype, ret_uuid); } static int block_get_size_by_fd(int fd, uint64_t *ret) { struct stat st; assert(fd >= 0); assert(ret); if (fstat(fd, &st) < 0) return -errno; if (!S_ISBLK(st.st_mode)) return -ENOTBLK; return blockdev_get_device_size(fd, ret); } static int block_get_size_by_path(const char *path, uint64_t *ret) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); if (fd < 0) return -errno; return block_get_size_by_fd(fd, ret); } static int run_fsck(const char *node, const char *fstype) { int r, exit_status; pid_t fsck_pid; assert(node); assert(fstype); r = fsck_exists_for_fstype(fstype); if (r < 0) return log_error_errno(r, "Failed to check if fsck for file system %s exists: %m", fstype); if (r == 0) { log_warning("No fsck for file system %s installed, ignoring.", fstype); return 0; } r = safe_fork("(fsck)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_STDOUT_TO_STDERR|FORK_CLOSE_ALL_FDS, &fsck_pid); if (r < 0) return r; if (r == 0) { /* Child */ execlp("fsck", "fsck", "-aTl", node, NULL); log_open(); log_error_errno(errno, "Failed to execute fsck: %m"); _exit(FSCK_OPERATIONAL_ERROR); } exit_status = wait_for_terminate_and_check("fsck", fsck_pid, WAIT_LOG_ABNORMAL); if (exit_status < 0) return exit_status; if ((exit_status & ~FSCK_ERROR_CORRECTED) != 0) { log_warning("fsck failed with exit status %i.", exit_status); if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "File system is corrupted, refusing."); log_warning("Ignoring fsck error."); } log_info("File system check completed."); return 1; } DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(key_serial_t, keyring_unlink, -1); static int upload_to_keyring(UserRecord *h, const void *vk, size_t vks, key_serial_t *ret) { _cleanup_free_ char *name = NULL; key_serial_t serial; assert(h); assert(vk); assert(vks > 0); /* We upload the LUKS volume key into the kernel session keyring, under the assumption that * systemd-homed gets its own private session keyring (i.e. the default service behavior, given * that KeyringMode=private is the default). That way, the key will survive between invocations * of systemd-homework. */ name = strjoin("homework-user-", h->user_name); if (!name) return -ENOMEM; serial = add_key("user", name, vk, vks, KEY_SPEC_SESSION_KEYRING); if (serial == -1) return -errno; if (ret) *ret = serial; return 1; } static int luks_try_passwords( UserRecord *h, struct crypt_device *cd, char **passwords, void *volume_key, size_t *volume_key_size) { int r; assert(h); assert(cd); assert(volume_key); assert(volume_key_size); STRV_FOREACH(pp, passwords) { size_t vks = *volume_key_size; r = sym_crypt_volume_key_get( cd, CRYPT_ANY_SLOT, volume_key, &vks, *pp, strlen(*pp)); if (r >= 0) { *volume_key_size = vks; return 0; } log_debug_errno(r, "Password %zu didn't work for unlocking LUKS superblock: %m", (size_t) (pp - passwords)); } return -ENOKEY; } static int luks_get_volume_key( UserRecord *h, struct crypt_device *cd, const PasswordCache *cache, void *volume_key, size_t *volume_key_size, key_serial_t *ret_key_serial) { char **list; size_t vks; int r; assert(h); assert(cd); assert(volume_key); assert(volume_key_size); if (cache && cache->volume_key) { /* Shortcut: If volume key was loaded from the keyring then just use it */ if (cache->volume_key_size > *volume_key_size) return log_error_errno(SYNTHETIC_ERRNO(ENOBUFS), "LUKS volume key from kernel keyring too big for buffer (need %zu bytes, have %zu).", cache->volume_key_size, *volume_key_size); memcpy(volume_key, cache->volume_key, cache->volume_key_size); *volume_key_size = cache->volume_key_size; if (ret_key_serial) *ret_key_serial = -1; /* Key came from keyring. No need to re-upload it */ return 0; } vks = *volume_key_size; FOREACH_ARGUMENT(list, cache ? cache->pkcs11_passwords : NULL, cache ? cache->fido2_passwords : NULL, h->password) { r = luks_try_passwords(h, cd, list, volume_key, &vks); if (r == -ENOKEY) continue; if (r < 0) return r; /* We got a volume key! */ if (ret_key_serial) { r = upload_to_keyring(h, volume_key, vks, ret_key_serial); if (r < 0) { log_warning_errno(r, "Failed to upload LUKS volume key to kernel keyring, ignoring: %m"); *ret_key_serial = -1; } } *volume_key_size = vks; return 0; } return -ENOKEY; } static int luks_setup( UserRecord *h, const char *node, const char *dm_name, sd_id128_t uuid, const char *cipher, const char *cipher_mode, uint64_t volume_key_size, const PasswordCache *cache, bool discard, struct crypt_device **ret, sd_id128_t *ret_found_uuid, void **ret_volume_key, size_t *ret_volume_key_size, key_serial_t *ret_key_serial) { _cleanup_(keyring_unlinkp) key_serial_t key_serial = -1; _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL; _cleanup_(erase_and_freep) void *vk = NULL; sd_id128_t p; size_t vks; int r; assert(h); assert(node); assert(dm_name); assert(ret); r = sym_crypt_init(&cd, node); if (r < 0) return log_error_errno(r, "Failed to allocate libcryptsetup context: %m"); cryptsetup_enable_logging(cd); r = sym_crypt_load(cd, CRYPT_LUKS2, NULL); if (r < 0) return log_error_errno(r, "Failed to load LUKS superblock: %m"); r = sym_crypt_get_volume_key_size(cd); if (r <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size."); vks = (size_t) r; if (!sd_id128_is_null(uuid) || ret_found_uuid) { const char *s; s = sym_crypt_get_uuid(cd); if (!s) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has no UUID."); r = sd_id128_from_string(s, &p); if (r < 0) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has invalid UUID."); /* Check that the UUID matches, if specified */ if (!sd_id128_is_null(uuid) && !sd_id128_equal(uuid, p)) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has wrong UUID."); } if (cipher && !streq_ptr(cipher, sym_crypt_get_cipher(cd))) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong cipher."); if (cipher_mode && !streq_ptr(cipher_mode, sym_crypt_get_cipher_mode(cd))) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong cipher mode."); if (volume_key_size != UINT64_MAX && vks != volume_key_size) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock declares wrong volume key size."); vk = malloc(vks); if (!vk) return log_oom(); r = luks_get_volume_key(h, cd, cache, vk, &vks, ret_key_serial ? &key_serial : NULL); if (r == -ENOKEY) return log_error_errno(r, "No valid password for LUKS superblock."); if (r < 0) return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); r = sym_crypt_activate_by_volume_key( cd, dm_name, vk, vks, discard ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0); if (r < 0) return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); log_info("Setting up LUKS device /dev/mapper/%s completed.", dm_name); *ret = TAKE_PTR(cd); if (ret_found_uuid) /* Return the UUID actually found if the caller wants to know */ *ret_found_uuid = p; if (ret_volume_key) *ret_volume_key = TAKE_PTR(vk); if (ret_volume_key_size) *ret_volume_key_size = vks; if (ret_key_serial) *ret_key_serial = TAKE_KEY_SERIAL(key_serial); return 0; } static int make_dm_names(UserRecord *h, HomeSetup *setup) { assert(h); assert(h->user_name); assert(setup); if (!setup->dm_name) { setup->dm_name = strjoin("home-", h->user_name); if (!setup->dm_name) return log_oom(); } if (!setup->dm_node) { setup->dm_node = path_join("/dev/mapper/", setup->dm_name); if (!setup->dm_node) return log_oom(); } return 0; } static int acquire_open_luks_device( UserRecord *h, HomeSetup *setup, bool graceful) { _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL; int r; assert(h); assert(setup); assert(!setup->crypt_device); r = dlopen_cryptsetup(); if (r < 0) return r; r = make_dm_names(h, setup); if (r < 0) return r; r = sym_crypt_init_by_name(&cd, setup->dm_name); if ((ERRNO_IS_NEG_DEVICE_ABSENT(r) || r == -EINVAL) && graceful) return 0; if (r < 0) return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", setup->dm_name); cryptsetup_enable_logging(cd); setup->crypt_device = TAKE_PTR(cd); return 1; } static int luks_open( UserRecord *h, HomeSetup *setup, const PasswordCache *cache, sd_id128_t *ret_found_uuid, void **ret_volume_key, size_t *ret_volume_key_size) { _cleanup_(erase_and_freep) void *vk = NULL; sd_id128_t p; size_t vks; int r; assert(h); assert(setup); assert(!setup->crypt_device); /* Opens a LUKS device that is already set up. Re-validates the password while doing so (which also * provides us with the volume key, which we want). */ r = acquire_open_luks_device(h, setup, /* graceful= */ false); if (r < 0) return r; r = sym_crypt_load(setup->crypt_device, CRYPT_LUKS2, NULL); if (r < 0) return log_error_errno(r, "Failed to load LUKS superblock: %m"); r = sym_crypt_get_volume_key_size(setup->crypt_device); if (r <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size."); vks = (size_t) r; if (ret_found_uuid) { const char *s; s = sym_crypt_get_uuid(setup->crypt_device); if (!s) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has no UUID."); r = sd_id128_from_string(s, &p); if (r < 0) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "LUKS superblock has invalid UUID."); } vk = malloc(vks); if (!vk) return log_oom(); r = luks_get_volume_key(h, setup->crypt_device, cache, vk, &vks, NULL); if (r == -ENOKEY) return log_error_errno(r, "No valid password for LUKS superblock."); if (r < 0) return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); log_info("Discovered used LUKS device /dev/mapper/%s, and validated password.", setup->dm_name); /* This is needed so that crypt_resize() can operate correctly for pre-existing LUKS devices. We need * to tell libcryptsetup the volume key explicitly, so that it is in the kernel keyring. */ r = sym_crypt_activate_by_volume_key(setup->crypt_device, NULL, vk, vks, CRYPT_ACTIVATE_KEYRING_KEY); if (r < 0) return log_error_errno(r, "Failed to upload volume key again: %m"); log_info("Successfully re-activated LUKS device."); if (ret_found_uuid) *ret_found_uuid = p; if (ret_volume_key) *ret_volume_key = TAKE_PTR(vk); if (ret_volume_key_size) *ret_volume_key_size = vks; return 0; } static int fs_validate( const char *dm_node, sd_id128_t uuid, char **ret_fstype, sd_id128_t *ret_found_uuid) { _cleanup_free_ char *fstype = NULL; sd_id128_t u = SD_ID128_NULL; /* avoid false maybe-unitialized warning */ int r; assert(dm_node); assert(ret_fstype); r = probe_file_system_by_path(dm_node, &fstype, &u); if (r < 0) return log_error_errno(r, "Failed to probe file system: %m"); /* Limit the set of supported file systems a bit, as protection against little tested kernel file * systems. Also, we only support the resize ioctls for these file systems. */ if (!supported_fstype(fstype)) return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "Image contains unsupported file system: %s", strna(fstype)); if (!sd_id128_is_null(uuid) && !sd_id128_equal(uuid, u)) return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "File system has wrong UUID."); log_info("Probing file system completed (found %s).", fstype); *ret_fstype = TAKE_PTR(fstype); if (ret_found_uuid) /* Return the UUID actually found if the caller wants to know */ *ret_found_uuid = u; return 0; } static int luks_validate( int fd, const char *label, sd_id128_t partition_uuid, sd_id128_t *ret_partition_uuid, uint64_t *ret_offset, uint64_t *ret_size) { _cleanup_(blkid_free_probep) blkid_probe b = NULL; sd_id128_t found_partition_uuid = SD_ID128_NULL; const char *fstype = NULL, *pttype = NULL; blkid_loff_t offset = 0, size = 0; blkid_partlist pl; bool found = false; int r, n; assert(fd >= 0); assert(label); assert(ret_offset); assert(ret_size); 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); (void) blkid_probe_enable_superblocks(b, 1); (void) blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE); (void) blkid_probe_enable_partitions(b, 1); (void) blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); errno = 0; r = blkid_do_safeprobe(b); if (r == _BLKID_SAFEPROBE_ERROR) return errno_or_else(EIO); if (IN_SET(r, _BLKID_SAFEPROBE_AMBIGUOUS, _BLKID_SAFEPROBE_NOT_FOUND)) return -ENOPKG; assert(r == _BLKID_SAFEPROBE_FOUND); (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); if (streq_ptr(fstype, "crypto_LUKS")) { /* Directly a LUKS image */ *ret_offset = 0; *ret_size = UINT64_MAX; /* full disk */ *ret_partition_uuid = SD_ID128_NULL; return 0; } else if (fstype) return -ENOPKG; (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL); if (!streq_ptr(pttype, "gpt")) return -ENOPKG; errno = 0; pl = blkid_probe_get_partitions(b); if (!pl) return errno_or_else(ENOMEM); errno = 0; n = blkid_partlist_numof_partitions(pl); if (n < 0) return errno_or_else(EIO); for (int i = 0; i < n; i++) { sd_id128_t id = SD_ID128_NULL; blkid_partition pp; errno = 0; pp = blkid_partlist_get_partition(pl, i); if (!pp) return errno_or_else(EIO); if (sd_id128_string_equal(blkid_partition_get_type_string(pp), SD_GPT_USER_HOME) <= 0) continue; if (!streq_ptr(blkid_partition_get_name(pp), label)) continue; r = blkid_partition_get_uuid_id128(pp, &id); if (r < 0) log_debug_errno(r, "Failed to read partition UUID, ignoring: %m"); else if (!sd_id128_is_null(partition_uuid) && !sd_id128_equal(id, partition_uuid)) continue; if (found) return -ENOPKG; offset = blkid_partition_get_start(pp); size = blkid_partition_get_size(pp); found_partition_uuid = id; found = true; } if (!found) return -ENOPKG; if (offset < 0) return -EINVAL; if ((uint64_t) offset > UINT64_MAX / 512U) return -EINVAL; if (size <= 0) return -EINVAL; if ((uint64_t) size > UINT64_MAX / 512U) return -EINVAL; *ret_offset = offset * 512U; *ret_size = size * 512U; *ret_partition_uuid = found_partition_uuid; return 0; } static int crypt_device_to_evp_cipher(struct crypt_device *cd, const EVP_CIPHER **ret) { _cleanup_free_ char *cipher_name = NULL; const char *cipher, *cipher_mode, *e; size_t key_size, key_bits; const EVP_CIPHER *cc; int r; assert(cd); /* Let's find the right OpenSSL EVP_CIPHER object that matches the encryption settings of the LUKS * device */ cipher = sym_crypt_get_cipher(cd); if (!cipher) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get cipher from LUKS device."); cipher_mode = sym_crypt_get_cipher_mode(cd); if (!cipher_mode) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get cipher mode from LUKS device."); e = strchr(cipher_mode, '-'); if (e) cipher_mode = strndupa_safe(cipher_mode, e - cipher_mode); r = sym_crypt_get_volume_key_size(cd); if (r <= 0) return log_error_errno(r < 0 ? r : SYNTHETIC_ERRNO(EINVAL), "Cannot get volume key size from LUKS device."); key_size = r; key_bits = key_size * 8; if (streq(cipher_mode, "xts")) key_bits /= 2; if (asprintf(&cipher_name, "%s-%zu-%s", cipher, key_bits, cipher_mode) < 0) return log_oom(); cc = EVP_get_cipherbyname(cipher_name); if (!cc) return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Selected cipher mode '%s' not supported, can't encrypt JSON record.", cipher_name); /* Verify that our key length calculations match what OpenSSL thinks */ r = EVP_CIPHER_key_length(cc); if (r < 0 || (uint64_t) r != key_size) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Key size of selected cipher doesn't meet our expectations."); *ret = cc; return 0; } static int luks_validate_home_record( struct crypt_device *cd, UserRecord *h, const void *volume_key, PasswordCache *cache, UserRecord **ret_luks_home_record) { int r; assert(cd); assert(h); for (int token = 0; token < sym_crypt_token_max(CRYPT_LUKS2); token++) { _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL, *rr = NULL; _cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL; _cleanup_(user_record_unrefp) UserRecord *lhr = NULL; _cleanup_free_ void *encrypted = NULL, *iv = NULL; size_t decrypted_size, encrypted_size, iv_size; int decrypted_size_out1, decrypted_size_out2; _cleanup_free_ char *decrypted = NULL; const char *text, *type; crypt_token_info state; sd_json_variant *jr, *jiv; unsigned line, column; const EVP_CIPHER *cc; state = sym_crypt_token_status(cd, token, &type); if (state == CRYPT_TOKEN_INACTIVE) /* First unconfigured token, give up */ break; if (IN_SET(state, CRYPT_TOKEN_INTERNAL, CRYPT_TOKEN_INTERNAL_UNKNOWN, CRYPT_TOKEN_EXTERNAL)) continue; if (state != CRYPT_TOKEN_EXTERNAL_UNKNOWN) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected token state of token %i: %i", token, (int) state); if (!streq(type, "systemd-homed")) continue; r = sym_crypt_token_json_get(cd, token, &text); if (r < 0) return log_error_errno(r, "Failed to read LUKS token %i: %m", token); r = sd_json_parse(text, SD_JSON_PARSE_SENSITIVE, &v, &line, &column); if (r < 0) return log_error_errno(r, "Failed to parse LUKS token JSON data %u:%u: %m", line, column); jr = sd_json_variant_by_key(v, "record"); if (!jr) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'record' field."); jiv = sd_json_variant_by_key(v, "iv"); if (!jiv) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'iv' field."); r = sd_json_variant_unbase64(jr, &encrypted, &encrypted_size); if (r < 0) return log_error_errno(r, "Failed to base64 decode record: %m"); r = sd_json_variant_unbase64(jiv, &iv, &iv_size); if (r < 0) return log_error_errno(r, "Failed to base64 decode IV: %m"); r = crypt_device_to_evp_cipher(cd, &cc); if (r < 0) return r; if (iv_size > INT_MAX || EVP_CIPHER_iv_length(cc) != (int) iv_size) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "IV size doesn't match."); context = EVP_CIPHER_CTX_new(); if (!context) return log_oom(); if (EVP_DecryptInit_ex(context, cc, NULL, volume_key, iv) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize decryption context."); decrypted_size = encrypted_size + EVP_CIPHER_key_length(cc) * 2; decrypted = new(char, decrypted_size); if (!decrypted) return log_oom(); if (EVP_DecryptUpdate(context, (uint8_t*) decrypted, &decrypted_size_out1, encrypted, encrypted_size) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to decrypt JSON record."); assert((size_t) decrypted_size_out1 <= decrypted_size); if (EVP_DecryptFinal_ex(context, (uint8_t*) decrypted + decrypted_size_out1, &decrypted_size_out2) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finish decryption of JSON record."); assert((size_t) decrypted_size_out1 + (size_t) decrypted_size_out2 < decrypted_size); decrypted_size = (size_t) decrypted_size_out1 + (size_t) decrypted_size_out2; if (memchr(decrypted, 0, decrypted_size)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Inner NUL byte in JSON record, refusing."); decrypted[decrypted_size] = 0; r = sd_json_parse(decrypted, SD_JSON_PARSE_SENSITIVE, &rr, NULL, NULL); if (r < 0) return log_error_errno(r, "Failed to parse decrypted JSON record, refusing."); lhr = user_record_new(); if (!lhr) return log_oom(); r = user_record_load(lhr, rr, USER_RECORD_LOAD_EMBEDDED|USER_RECORD_PERMISSIVE); if (r < 0) return log_error_errno(r, "Failed to parse user record: %m"); if (!user_record_compatible(h, lhr)) return log_error_errno(SYNTHETIC_ERRNO(EREMCHG), "LUKS home record not compatible with host record, refusing."); r = user_record_authenticate(lhr, h, cache, /* strict_verify= */ true); if (r < 0) return r; assert(r > 0); /* Insist that a password was verified */ *ret_luks_home_record = TAKE_PTR(lhr); return 0; } return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Couldn't find home record in LUKS2 header, refusing."); } static int format_luks_token_text( struct crypt_device *cd, UserRecord *hr, const void *volume_key, char **ret) { int r, encrypted_size_out1 = 0, encrypted_size_out2 = 0, iv_size, key_size; _cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL; _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL; _cleanup_free_ void *iv = NULL, *encrypted = NULL; size_t text_length, encrypted_size; _cleanup_free_ char *text = NULL; const EVP_CIPHER *cc; assert(cd); assert(hr); assert(volume_key); assert(ret); r = crypt_device_to_evp_cipher(cd, &cc); if (r < 0) return r; key_size = EVP_CIPHER_key_length(cc); iv_size = EVP_CIPHER_iv_length(cc); if (iv_size > 0) { iv = malloc(iv_size); if (!iv) return log_oom(); r = crypto_random_bytes(iv, iv_size); if (r < 0) return log_error_errno(r, "Failed to generate IV: %m"); } context = EVP_CIPHER_CTX_new(); if (!context) return log_oom(); if (EVP_EncryptInit_ex(context, cc, NULL, volume_key, iv) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize encryption context."); r = sd_json_variant_format(hr->json, 0, &text); if (r < 0) return log_error_errno(r, "Failed to format user record for LUKS: %m"); text_length = strlen(text); encrypted_size = text_length + 2*key_size - 1; encrypted = malloc(encrypted_size); if (!encrypted) return log_oom(); if (EVP_EncryptUpdate(context, encrypted, &encrypted_size_out1, (uint8_t*) text, text_length) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to encrypt JSON record."); assert((size_t) encrypted_size_out1 <= encrypted_size); if (EVP_EncryptFinal_ex(context, (uint8_t*) encrypted + encrypted_size_out1, &encrypted_size_out2) != 1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finish encryption of JSON record."); assert((size_t) encrypted_size_out1 + (size_t) encrypted_size_out2 <= encrypted_size); r = sd_json_buildo( &v, SD_JSON_BUILD_PAIR("type", JSON_BUILD_CONST_STRING("systemd-homed")), SD_JSON_BUILD_PAIR("keyslots", SD_JSON_BUILD_EMPTY_ARRAY), SD_JSON_BUILD_PAIR("record", SD_JSON_BUILD_BASE64(encrypted, encrypted_size_out1 + encrypted_size_out2)), SD_JSON_BUILD_PAIR("iv", SD_JSON_BUILD_BASE64(iv, iv_size))); if (r < 0) return log_error_errno(r, "Failed to prepare LUKS JSON token object: %m"); r = sd_json_variant_format(v, 0, ret); if (r < 0) return log_error_errno(r, "Failed to format encrypted user record for LUKS: %m"); return 0; } int home_store_header_identity_luks( UserRecord *h, HomeSetup *setup, UserRecord *old_home) { _cleanup_(user_record_unrefp) UserRecord *header_home = NULL; _cleanup_free_ char *text = NULL; int r; assert(h); if (!setup->crypt_device) return 0; assert(setup->volume_key); /* Let's store the user's identity record in the LUKS2 "token" header data fields, in an encrypted * fashion. Why that? If we'd rely on the record being embedded in the payload file system itself we * would have to mount the file system before we can validate the JSON record, its signatures and * whether it matches what we are looking for. However, kernel file system implementations are * generally not ready to be used on untrusted media. Hence let's store the record independently of * the file system, so that we can validate it first, and only then mount the file system. To keep * things simple we use the same encryption settings for this record as for the file system itself. */ r = user_record_clone(h, USER_RECORD_EXTRACT_EMBEDDED|USER_RECORD_PERMISSIVE, &header_home); if (r < 0) return log_error_errno(r, "Failed to determine new header record: %m"); if (old_home && user_record_equal(old_home, header_home)) { log_debug("Not updating header home record."); return 0; } r = format_luks_token_text(setup->crypt_device, header_home, setup->volume_key, &text); if (r < 0) return r; for (int token = 0; token < sym_crypt_token_max(CRYPT_LUKS2); token++) { crypt_token_info state; const char *type; state = sym_crypt_token_status(setup->crypt_device, token, &type); if (state == CRYPT_TOKEN_INACTIVE) /* First unconfigured token, we are done */ break; if (IN_SET(state, CRYPT_TOKEN_INTERNAL, CRYPT_TOKEN_INTERNAL_UNKNOWN, CRYPT_TOKEN_EXTERNAL)) continue; /* Not ours */ if (state != CRYPT_TOKEN_EXTERNAL_UNKNOWN) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected token state of token %i: %i", token, (int) state); if (!streq(type, "systemd-homed")) continue; r = sym_crypt_token_json_set(setup->crypt_device, token, text); if (r < 0) return log_error_errno(r, "Failed to set JSON token for slot %i: %m", token); /* Now, let's free the text so that for all further matching tokens we all crypt_json_token_set() * with a NULL text in order to invalidate the tokens. */ text = mfree(text); } if (text) return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Didn't find any record token to update."); log_info("Wrote LUKS header user record."); return 1; } int run_fitrim(int root_fd) { struct fstrim_range range = { .len = UINT64_MAX, }; /* If discarding is on, discard everything right after mounting, so that the discard setting takes * effect on activation. (Also, optionally, trim on logout) */ assert(root_fd >= 0); if (ioctl(root_fd, FITRIM, &range) < 0) { if (ERRNO_IS_NOT_SUPPORTED(errno) || errno == EBADF) { log_debug_errno(errno, "File system does not support FITRIM, not trimming."); return 0; } return log_warning_errno(errno, "Failed to invoke FITRIM, ignoring: %m"); } log_info("Discarded unused %s.", FORMAT_BYTES(range.len)); return 1; } int run_fallocate(int backing_fd, const struct stat *st) { struct stat stbuf; assert(backing_fd >= 0); /* If discarding is off, let's allocate the whole image before mounting, so that the setting takes * effect on activation */ if (!st) { if (fstat(backing_fd, &stbuf) < 0) return log_error_errno(errno, "Failed to fstat(): %m"); st = &stbuf; } if (!S_ISREG(st->st_mode)) return 0; if (st->st_blocks >= DIV_ROUND_UP(st->st_size, 512)) { log_info("Backing file is fully allocated already."); return 0; } if (fallocate(backing_fd, FALLOC_FL_KEEP_SIZE, 0, st->st_size) < 0) { if (ERRNO_IS_NOT_SUPPORTED(errno)) { log_debug_errno(errno, "fallocate() not supported on file system, ignoring."); return 0; } if (ERRNO_IS_DISK_SPACE(errno)) { log_debug_errno(errno, "Not enough disk space to fully allocate home."); return -ENOSPC; /* make recognizable */ } return log_error_errno(errno, "Failed to allocate backing file blocks: %m"); } log_info("Allocated additional %s.", FORMAT_BYTES((DIV_ROUND_UP(st->st_size, 512) - st->st_blocks) * 512)); return 1; } int run_fallocate_by_path(const char *backing_path) { _cleanup_close_ int backing_fd = -EBADF; backing_fd = open(backing_path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); if (backing_fd < 0) return log_error_errno(errno, "Failed to open '%s' for fallocate(): %m", backing_path); return run_fallocate(backing_fd, NULL); } static int lock_image_fd(int image_fd, const char *ip) { int r; /* If the $SYSTEMD_LUKS_LOCK environment variable is set we'll take an exclusive BSD lock on the * image file, and send it to our parent. homed will keep it open to ensure no other instance of * homed (across the network or such) will also mount the file. */ assert(image_fd >= 0); assert(ip); r = getenv_bool("SYSTEMD_LUKS_LOCK"); if (r == -ENXIO) return 0; if (r < 0) return log_error_errno(r, "Failed to parse $SYSTEMD_LUKS_LOCK environment variable: %m"); if (r == 0) return 0; if (flock(image_fd, LOCK_EX|LOCK_NB) < 0) { if (errno == EAGAIN) log_error_errno(errno, "Image file '%s' already locked, can't use.", ip); else log_error_errno(errno, "Failed to lock image file '%s': %m", ip); return errno != EAGAIN ? -errno : -EADDRINUSE; /* Make error recognizable */ } log_info("Successfully locked image file '%s'.", ip); /* Now send it to our parent to keep safe while the home dir is active */ r = sd_pid_notify_with_fds(0, false, "SYSTEMD_LUKS_LOCK_FD=1", &image_fd, 1); if (r < 0) log_warning_errno(r, "Failed to send LUKS lock fd to parent, ignoring: %m"); return 0; } static int open_image_file( UserRecord *h, const char *force_image_path, struct stat *ret_stat) { _cleanup_close_ int image_fd = -EBADF; struct stat st; const char *ip; int r; assert(h || force_image_path); ip = force_image_path ?: user_record_image_path(h); image_fd = open(ip, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); if (image_fd < 0) return log_error_errno(errno, "Failed to open image file %s: %m", ip); if (fstat(image_fd, &st) < 0) return log_error_errno(errno, "Failed to fstat() image file: %m"); if (!S_ISREG(st.st_mode) && !S_ISBLK(st.st_mode)) return log_error_errno( S_ISDIR(st.st_mode) ? SYNTHETIC_ERRNO(EISDIR) : SYNTHETIC_ERRNO(EBADFD), "Image file %s is not a regular file or block device: %m", ip); /* Locking block devices doesn't really make sense, as this might interfere with * udev's workings, and these locks aren't network propagated anyway, hence not what * we are after here. */ if (S_ISREG(st.st_mode)) { r = lock_image_fd(image_fd, ip); if (r < 0) return r; } if (ret_stat) *ret_stat = st; return TAKE_FD(image_fd); } int home_setup_luks( UserRecord *h, HomeSetupFlags flags, const char *force_image_path, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_luks_home) { sd_id128_t found_partition_uuid, found_fs_uuid = SD_ID128_NULL, found_luks_uuid = SD_ID128_NULL; _cleanup_(user_record_unrefp) UserRecord *luks_home = NULL; _cleanup_(erase_and_freep) void *volume_key = NULL; size_t volume_key_size = 0; uint64_t offset, size; struct stat st; int r; assert(h); assert(setup); assert(user_record_storage(h) == USER_LUKS); r = dlopen_cryptsetup(); if (r < 0) return r; r = make_dm_names(h, setup); if (r < 0) return r; /* Reuse the image fd if it has already been opened by an earlier step */ if (setup->image_fd < 0) { setup->image_fd = open_image_file(h, force_image_path, &st); if (setup->image_fd < 0) return setup->image_fd; } else if (fstat(setup->image_fd, &st) < 0) return log_error_errno(errno, "Failed to stat image: %m"); if (FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) { struct loop_info64 info; const char *n; if (!setup->crypt_device) { r = luks_open(h, setup, cache, &found_luks_uuid, &volume_key, &volume_key_size); if (r < 0) return r; } if (ret_luks_home) { r = luks_validate_home_record(setup->crypt_device, h, volume_key, cache, &luks_home); if (r < 0) return r; } n = sym_crypt_get_device_name(setup->crypt_device); if (!n) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine backing device for DM %s.", setup->dm_name); if (!setup->loop) { r = loop_device_open_from_path(n, O_RDWR, LOCK_UN, &setup->loop); if (r < 0) return log_error_errno(r, "Failed to open loopback device %s: %m", n); } if (ioctl(setup->loop->fd, LOOP_GET_STATUS64, &info) < 0) { _cleanup_free_ char *sysfs = NULL; if (!IN_SET(errno, ENOTTY, EINVAL)) return log_error_errno(errno, "Failed to get block device metrics of %s: %m", n); if (fstat(setup->loop->fd, &st) < 0) return log_error_errno(r, "Failed to stat block device %s: %m", n); assert(S_ISBLK(st.st_mode)); if (asprintf(&sysfs, "/sys/dev/block/" DEVNUM_FORMAT_STR "/partition", DEVNUM_FORMAT_VAL(st.st_rdev)) < 0) return log_oom(); if (access(sysfs, F_OK) < 0) { if (errno != ENOENT) return log_error_errno(errno, "Failed to determine whether %s exists: %m", sysfs); offset = 0; } else { _cleanup_free_ char *buffer = NULL; if (asprintf(&sysfs, "/sys/dev/block/" DEVNUM_FORMAT_STR "/start", DEVNUM_FORMAT_VAL(st.st_rdev)) < 0) return log_oom(); r = read_one_line_file(sysfs, &buffer); if (r < 0) return log_error_errno(r, "Failed to read partition start offset: %m"); r = safe_atou64(buffer, &offset); if (r < 0) return log_error_errno(r, "Failed to parse partition start offset: %m"); if (offset > UINT64_MAX / 512U) return log_error_errno(SYNTHETIC_ERRNO(E2BIG), "Offset too large for 64 byte range, refusing."); offset *= 512U; } size = setup->loop->device_size; } else { #if HAVE_VALGRIND_MEMCHECK_H VALGRIND_MAKE_MEM_DEFINED(&info, sizeof(info)); #endif offset = info.lo_offset; size = info.lo_sizelimit; } found_partition_uuid = found_fs_uuid = SD_ID128_NULL; log_info("Discovered used loopback device %s.", setup->loop->node); if (setup->root_fd < 0) { setup->root_fd = open(user_record_home_directory(h), O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (setup->root_fd < 0) return log_error_errno(errno, "Failed to open home directory: %m"); } } else { _cleanup_free_ char *fstype = NULL, *subdir = NULL; const char *ip; /* When we aren't reopening the home directory we are allocating it fresh, hence the relevant * objects can't be allocated yet. */ assert(setup->root_fd < 0); assert(!setup->crypt_device); assert(!setup->loop); ip = force_image_path ?: user_record_image_path(h); subdir = path_join(HOME_RUNTIME_WORK_DIR, user_record_user_name_and_realm(h)); if (!subdir) return log_oom(); r = luks_validate(setup->image_fd, user_record_user_name_and_realm(h), h->partition_uuid, &found_partition_uuid, &offset, &size); if (r < 0) return log_error_errno(r, "Failed to validate disk label: %m"); /* Everything before this point left the image untouched. We are now starting to make * changes, hence mark the image dirty */ if (run_mark_dirty(setup->image_fd, true) > 0) setup->do_mark_clean = true; if (!user_record_luks_discard(h)) { r = run_fallocate(setup->image_fd, &st); if (r < 0) return r; } r = loop_device_make( setup->image_fd, O_RDWR, offset, size, h->luks_sector_size == UINT64_MAX ? UINT32_MAX : user_record_luks_sector_size(h), /* if sector size is not specified, select UINT32_MAX, i.e. auto-probe */ /* loop_flags= */ 0, LOCK_UN, &setup->loop); if (r == -ENOENT) { log_error_errno(r, "Loopback block device support is not available on this system."); return -ENOLINK; /* make recognizable */ } if (r < 0) return log_error_errno(r, "Failed to allocate loopback context: %m"); log_info("Setting up loopback device %s completed.", setup->loop->node ?: ip); r = luks_setup(h, setup->loop->node ?: ip, setup->dm_name, h->luks_uuid, h->luks_cipher, h->luks_cipher_mode, h->luks_volume_key_size, cache, user_record_luks_discard(h) || user_record_luks_offline_discard(h), &setup->crypt_device, &found_luks_uuid, &volume_key, &volume_key_size, &setup->key_serial); if (r < 0) return r; setup->undo_dm = true; if (ret_luks_home) { r = luks_validate_home_record(setup->crypt_device, h, volume_key, cache, &luks_home); if (r < 0) return r; } r = fs_validate(setup->dm_node, h->file_system_uuid, &fstype, &found_fs_uuid); if (r < 0) return r; r = run_fsck(setup->dm_node, fstype); if (r < 0) return r; r = home_unshare_and_mount(setup->dm_node, fstype, user_record_luks_discard(h), user_record_mount_flags(h), h->luks_extra_mount_options); if (r < 0) return r; setup->undo_mount = true; setup->root_fd = open(subdir, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (setup->root_fd < 0) return log_error_errno(errno, "Failed to open home directory: %m"); if (user_record_luks_discard(h)) (void) run_fitrim(setup->root_fd); setup->do_offline_fallocate = !(setup->do_offline_fitrim = user_record_luks_offline_discard(h)); } if (!sd_id128_is_null(found_partition_uuid)) setup->found_partition_uuid = found_partition_uuid; if (!sd_id128_is_null(found_luks_uuid)) setup->found_luks_uuid = found_luks_uuid; if (!sd_id128_is_null(found_fs_uuid)) setup->found_fs_uuid = found_fs_uuid; setup->partition_offset = offset; setup->partition_size = size; if (volume_key) { erase_and_free(setup->volume_key); setup->volume_key = TAKE_PTR(volume_key); setup->volume_key_size = volume_key_size; } if (ret_luks_home) *ret_luks_home = TAKE_PTR(luks_home); return 0; } static void print_size_summary(uint64_t host_size, uint64_t encrypted_size, const struct statfs *sfs) { assert(sfs); log_info("Image size is %s, file system size is %s, file system payload size is %s, file system free is %s.", FORMAT_BYTES(host_size), FORMAT_BYTES(encrypted_size), FORMAT_BYTES((uint64_t) sfs->f_blocks * (uint64_t) sfs->f_frsize), FORMAT_BYTES((uint64_t) sfs->f_bfree * (uint64_t) sfs->f_frsize)); } static int home_auto_grow_luks( UserRecord *h, HomeSetup *setup, PasswordCache *cache) { struct statfs sfs; assert(h); assert(setup); if (!IN_SET(user_record_auto_resize_mode(h), AUTO_RESIZE_GROW, AUTO_RESIZE_SHRINK_AND_GROW)) return 0; assert(setup->root_fd >= 0); if (fstatfs(setup->root_fd, &sfs) < 0) return log_error_errno(errno, "Failed to statfs home directory: %m"); if (!fs_can_online_shrink_and_grow(sfs.f_type)) { log_debug("Not auto-grow file system, since selected file system cannot do both online shrink and grow."); return 0; } log_debug("Initiating auto-grow..."); return home_resize_luks( h, HOME_SETUP_ALREADY_ACTIVATED| HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES| HOME_SETUP_RESIZE_DONT_SHRINK| HOME_SETUP_RESIZE_DONT_UNDO, setup, cache, NULL); } int home_activate_luks( UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home) { _cleanup_(user_record_unrefp) UserRecord *new_home = NULL, *luks_home_record = NULL; uint64_t host_size, encrypted_size; const char *hdo, *hd; struct statfs sfs; int r; assert(h); assert(user_record_storage(h) == USER_LUKS); assert(setup); assert(ret_home); r = dlopen_cryptsetup(); if (r < 0) return r; assert_se(hdo = user_record_home_directory(h)); hd = strdupa_safe(hdo); /* copy the string out, since it might change later in the home record object */ r = home_get_state_luks(h, setup); if (r < 0) return r; if (r > 0) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Device mapper device %s already exists, refusing.", setup->dm_node); r = home_setup_luks( h, 0, NULL, setup, cache, &luks_home_record); if (r < 0) return r; r = home_auto_grow_luks(h, setup, cache); if (r < 0) return r; r = block_get_size_by_fd(setup->loop->fd, &host_size); if (r < 0) return log_error_errno(r, "Failed to get loopback block device size: %m"); r = block_get_size_by_path(setup->dm_node, &encrypted_size); if (r < 0) return log_error_errno(r, "Failed to get LUKS block device size: %m"); r = home_refresh( h, flags, setup, luks_home_record, cache, &sfs, &new_home); if (r < 0) return r; r = home_extend_embedded_identity(new_home, h, setup); if (r < 0) return r; setup->root_fd = safe_close(setup->root_fd); r = home_move_mount(user_record_user_name_and_realm(h), hd); if (r < 0) return r; setup->undo_mount = false; setup->do_offline_fitrim = false; loop_device_relinquish(setup->loop); r = sym_crypt_deactivate_by_name(NULL, setup->dm_name, CRYPT_DEACTIVATE_DEFERRED); if (r < 0) log_warning_errno(r, "Failed to relinquish DM device, ignoring: %m"); setup->undo_dm = false; setup->do_offline_fallocate = false; setup->do_mark_clean = false; setup->do_drop_caches = false; TAKE_KEY_SERIAL(setup->key_serial); /* Leave key in kernel keyring */ log_info("Activation completed."); print_size_summary(host_size, encrypted_size, &sfs); *ret_home = TAKE_PTR(new_home); return 1; } int home_deactivate_luks(UserRecord *h, HomeSetup *setup) { bool we_detached = false; int r; assert(h); assert(setup); /* Note that the DM device and loopback device are set to auto-detach, hence strictly speaking we * don't have to explicitly have to detach them. However, we do that nonetheless (in case of the DM * device), to avoid races: by explicitly detaching them we know when the detaching is complete. We * don't bother about the loopback device because unlike the DM device it doesn't have a fixed * name. */ if (!setup->crypt_device) { r = acquire_open_luks_device(h, setup, /* graceful= */ true); if (r < 0) return log_error_errno(r, "Failed to initialize cryptsetup context for %s: %m", setup->dm_name); if (r == 0) log_debug("LUKS device %s has already been detached.", setup->dm_name); } if (setup->crypt_device) { log_info("Discovered used LUKS device %s.", setup->dm_node); cryptsetup_enable_logging(setup->crypt_device); r = sym_crypt_deactivate_by_name(setup->crypt_device, setup->dm_name, 0); if (ERRNO_IS_NEG_DEVICE_ABSENT(r) || r == -EINVAL) log_debug_errno(r, "LUKS device %s is already detached.", setup->dm_node); else if (r < 0) return log_info_errno(r, "LUKS device %s couldn't be deactivated: %m", setup->dm_node); else { log_info("LUKS device detaching completed."); we_detached = true; } } (void) wait_for_block_device_gone(setup, USEC_PER_SEC * 30); setup->undo_dm = false; if (user_record_luks_offline_discard(h)) log_debug("Not allocating on logout."); else (void) run_fallocate_by_path(user_record_image_path(h)); run_mark_dirty_by_path(user_record_image_path(h), false); return we_detached; } int home_trim_luks(UserRecord *h, HomeSetup *setup) { assert(h); assert(setup); assert(setup->root_fd >= 0); if (!user_record_luks_offline_discard(h)) { log_debug("Not trimming on logout."); return 0; } (void) run_fitrim(setup->root_fd); return 0; } static struct crypt_pbkdf_type* build_good_pbkdf(struct crypt_pbkdf_type *buffer, UserRecord *hr) { assert(buffer); assert(hr); bool benchmark = user_record_luks_pbkdf_force_iterations(hr) == UINT64_MAX; *buffer = (struct crypt_pbkdf_type) { .hash = user_record_luks_pbkdf_hash_algorithm(hr), .type = user_record_luks_pbkdf_type(hr), .time_ms = benchmark ? user_record_luks_pbkdf_time_cost_usec(hr) / USEC_PER_MSEC : 0, .iterations = benchmark ? 0 : user_record_luks_pbkdf_force_iterations(hr), .max_memory_kb = user_record_luks_pbkdf_memory_cost(hr) / 1024, .parallel_threads = user_record_luks_pbkdf_parallel_threads(hr), .flags = benchmark ? 0 : CRYPT_PBKDF_NO_BENCHMARK, }; return buffer; } static struct crypt_pbkdf_type* build_minimal_pbkdf(struct crypt_pbkdf_type *buffer, UserRecord *hr) { assert(buffer); assert(hr); /* For PKCS#11 derived keys (which are generated randomly and are of high quality already) we use a * minimal PBKDF and CRYPT_PBKDF_NO_BENCHMARK flag to skip benchmark. */ *buffer = (struct crypt_pbkdf_type) { .hash = user_record_luks_pbkdf_hash_algorithm(hr), .type = CRYPT_KDF_PBKDF2, .iterations = 1000, /* recommended minimum count for pbkdf2 * according to NIST SP 800-132, ch. 5.2 */ .flags = CRYPT_PBKDF_NO_BENCHMARK }; return buffer; } static int luks_format( const char *node, const char *dm_name, sd_id128_t uuid, const char *label, const PasswordCache *cache, char **effective_passwords, bool discard, UserRecord *hr, struct crypt_device **ret) { _cleanup_(user_record_unrefp) UserRecord *reduced = NULL; _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL; _cleanup_(erase_and_freep) void *volume_key = NULL; struct crypt_pbkdf_type good_pbkdf, minimal_pbkdf; _cleanup_free_ char *text = NULL; size_t volume_key_size; int slot = 0, r; assert(node); assert(dm_name); assert(hr); assert(ret); r = sym_crypt_init(&cd, node); if (r < 0) return log_error_errno(r, "Failed to allocate libcryptsetup context: %m"); cryptsetup_enable_logging(cd); /* Normally we'd, just leave volume key generation to libcryptsetup. However, we can't, since we * can't extract the volume key from the library again, but we need it in order to encrypt the JSON * record. Hence, let's generate it on our own, so that we can keep track of it. */ volume_key_size = user_record_luks_volume_key_size(hr); volume_key = malloc(volume_key_size); if (!volume_key) return log_oom(); r = crypto_random_bytes(volume_key, volume_key_size); if (r < 0) return log_error_errno(r, "Failed to generate volume key: %m"); #if HAVE_CRYPT_SET_METADATA_SIZE /* Increase the metadata space to 4M, the largest LUKS2 supports */ r = sym_crypt_set_metadata_size(cd, 4096U*1024U, 0); if (r < 0) return log_error_errno(r, "Failed to change LUKS2 metadata size: %m"); #endif build_good_pbkdf(&good_pbkdf, hr); build_minimal_pbkdf(&minimal_pbkdf, hr); r = sym_crypt_format( cd, CRYPT_LUKS2, user_record_luks_cipher(hr), user_record_luks_cipher_mode(hr), SD_ID128_TO_UUID_STRING(uuid), volume_key, volume_key_size, &(struct crypt_params_luks2) { .label = label, .subsystem = "systemd-home", .sector_size = user_record_luks_sector_size(hr), .pbkdf = &good_pbkdf, }); if (r < 0) return log_error_errno(r, "Failed to format LUKS image: %m"); log_info("LUKS formatting completed."); STRV_FOREACH(pp, effective_passwords) { if (password_cache_contains(cache, *pp)) { /* is this a fido2 or pkcs11 password? */ log_debug("Using minimal PBKDF for slot %i", slot); r = sym_crypt_set_pbkdf_type(cd, &minimal_pbkdf); } else { log_debug("Using good PBKDF for slot %i", slot); r = sym_crypt_set_pbkdf_type(cd, &good_pbkdf); } if (r < 0) return log_error_errno(r, "Failed to tweak PBKDF for slot %i: %m", slot); r = sym_crypt_keyslot_add_by_volume_key( cd, slot, volume_key, volume_key_size, *pp, strlen(*pp)); if (r < 0) return log_error_errno(r, "Failed to set up LUKS password for slot %i: %m", slot); log_info("Writing password to LUKS keyslot %i completed.", slot); slot++; } r = sym_crypt_activate_by_volume_key( cd, dm_name, volume_key, volume_key_size, discard ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0); if (r < 0) return log_error_errno(r, "Failed to activate LUKS superblock: %m"); log_info("LUKS activation by volume key succeeded."); r = user_record_clone(hr, USER_RECORD_EXTRACT_EMBEDDED|USER_RECORD_PERMISSIVE, &reduced); if (r < 0) return log_error_errno(r, "Failed to prepare home record for LUKS: %m"); r = format_luks_token_text(cd, reduced, volume_key, &text); if (r < 0) return r; r = sym_crypt_token_json_set(cd, CRYPT_ANY_TOKEN, text); if (r < 0) return log_error_errno(r, "Failed to set LUKS JSON token: %m"); log_info("Writing user record as LUKS token completed."); if (ret) *ret = TAKE_PTR(cd); return 0; } static int make_partition_table( int fd, uint32_t sector_size, const char *label, sd_id128_t uuid, uint64_t *ret_offset, uint64_t *ret_size, sd_id128_t *ret_disk_uuid) { _cleanup_(fdisk_unref_partitionp) struct fdisk_partition *p = NULL, *q = NULL; _cleanup_(fdisk_unref_parttypep) struct fdisk_parttype *t = NULL; _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; _cleanup_free_ char *disk_uuid_as_string = NULL; uint64_t offset, size, first_lba, start, last_lba, end; sd_id128_t disk_uuid; int r; assert(fd >= 0); assert(label); assert(ret_offset); assert(ret_size); t = fdisk_new_parttype(); if (!t) return log_oom(); r = fdisk_parttype_set_typestr(t, SD_GPT_USER_HOME_STR); if (r < 0) return log_error_errno(r, "Failed to initialize partition type: %m"); r = fdisk_new_context_at(fd, /* path= */ NULL, /* read_only= */ false, sector_size, &c); if (r < 0) return log_error_errno(r, "Failed to open device: %m"); r = fdisk_create_disklabel(c, "gpt"); if (r < 0) return log_error_errno(r, "Failed to create GPT disk label: %m"); p = fdisk_new_partition(); if (!p) return log_oom(); r = fdisk_partition_set_type(p, t); if (r < 0) return log_error_errno(r, "Failed to set partition type: %m"); r = fdisk_partition_partno_follow_default(p, 1); if (r < 0) return log_error_errno(r, "Failed to place partition at first free partition index: %m"); first_lba = fdisk_get_first_lba(c); /* Boundary where usable space starts */ assert(first_lba <= UINT64_MAX/512); start = DISK_SIZE_ROUND_UP(first_lba * 512); /* Round up to multiple of 4K */ log_debug("Starting partition at offset %" PRIu64, start); if (start == UINT64_MAX) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Overflow while rounding up start LBA."); last_lba = fdisk_get_last_lba(c); /* One sector before boundary where usable space ends */ assert(last_lba < UINT64_MAX/512); end = DISK_SIZE_ROUND_DOWN((last_lba + 1) * 512); /* Round down to multiple of 4K */ if (end <= start) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Resulting partition size zero or negative."); r = fdisk_partition_set_start(p, start / 512); if (r < 0) return log_error_errno(r, "Failed to place partition at offset %" PRIu64 ": %m", start); r = fdisk_partition_set_size(p, (end - start) / 512); if (r < 0) return log_error_errno(r, "Failed to end partition at offset %" PRIu64 ": %m", end); r = fdisk_partition_set_name(p, label); if (r < 0) return log_error_errno(r, "Failed to set partition name: %m"); r = fdisk_partition_set_uuid(p, SD_ID128_TO_UUID_STRING(uuid)); if (r < 0) return log_error_errno(r, "Failed to set partition UUID: %m"); r = fdisk_add_partition(c, p, NULL); if (r < 0) return log_error_errno(r, "Failed to add partition: %m"); r = fdisk_write_disklabel(c); if (r < 0) return log_error_errno(r, "Failed to write disk label: %m"); r = fdisk_get_disklabel_id(c, &disk_uuid_as_string); if (r < 0) return log_error_errno(r, "Failed to determine disk label UUID: %m"); r = sd_id128_from_string(disk_uuid_as_string, &disk_uuid); if (r < 0) return log_error_errno(r, "Failed to parse disk label UUID: %m"); r = fdisk_get_partition(c, 0, &q); if (r < 0) return log_error_errno(r, "Failed to read created partition metadata: %m"); assert(fdisk_partition_has_start(q)); offset = fdisk_partition_get_start(q); if (offset > UINT64_MAX / 512U) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Partition offset too large."); assert(fdisk_partition_has_size(q)); size = fdisk_partition_get_size(q); if (size > UINT64_MAX / 512U) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Partition size too large."); *ret_offset = offset * 512U; *ret_size = size * 512U; *ret_disk_uuid = disk_uuid; return 0; } static bool supported_fs_size(const char *fstype, uint64_t host_size) { uint64_t m; m = minimal_size_by_fs_name(fstype); if (m == UINT64_MAX) return false; return host_size >= m; } static int wait_for_devlink(const char *path) { _cleanup_close_ int inotify_fd = -EBADF; usec_t until; int r; /* let's wait for a device link to show up in /dev, with a timeout. This is good to do since we * return a /dev/disk/by-uuid/… link to our callers and they likely want to access it right-away, * hence let's wait until udev has caught up with our changes, and wait for the symlink to be * created. */ until = usec_add(now(CLOCK_MONOTONIC), 45 * USEC_PER_SEC); for (;;) { _cleanup_free_ char *dn = NULL; usec_t w; r = access_nofollow(path, F_OK); if (r >= 0) return 0; /* Found it */ if (r != -ENOENT) return log_error_errno(r, "Failed to determine whether %s exists: %m", path); if (inotify_fd < 0) { /* We need to wait for the device symlink to show up, let's create an inotify watch for it */ inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC); if (inotify_fd < 0) return log_error_errno(errno, "Failed to allocate inotify fd: %m"); } r = path_extract_directory(path, &dn); if (r < 0) return log_error_errno(r, "Failed to extract directory from device node path '%s': %m", path); for (;;) { _cleanup_free_ char *ndn = NULL; log_info("Watching %s", dn); if (inotify_add_watch(inotify_fd, dn, IN_CREATE|IN_MOVED_TO|IN_ONLYDIR|IN_DELETE_SELF|IN_MOVE_SELF) < 0) { if (errno != ENOENT) return log_error_errno(errno, "Failed to add watch on %s: %m", dn); } else break; r = path_extract_directory(dn, &ndn); if (r == -EADDRNOTAVAIL) /* Arrived at the top? */ break; if (r < 0) return log_error_errno(r, "Failed to extract directory from device node path '%s': %m", dn); free_and_replace(dn, ndn); } w = now(CLOCK_MONOTONIC); if (w >= until) return log_error_errno(SYNTHETIC_ERRNO(ETIMEDOUT), "Device link %s still hasn't shown up, giving up.", path); r = fd_wait_for_event(inotify_fd, POLLIN, until - w); if (ERRNO_IS_NEG_TRANSIENT(r)) continue; if (r < 0) return log_error_errno(r, "Failed to watch inotify: %m"); (void) flush_fd(inotify_fd); } } static int calculate_initial_image_size(UserRecord *h, int image_fd, const char *fstype, uint64_t *ret) { uint64_t upper_boundary, lower_boundary; struct statfs sfs; assert(h); assert(image_fd >= 0); assert(ret); if (fstatfs(image_fd, &sfs) < 0) return log_error_errno(errno, "statfs() on image failed: %m"); upper_boundary = DISK_SIZE_ROUND_DOWN((uint64_t) sfs.f_bsize * sfs.f_bavail); if (h->disk_size != UINT64_MAX) *ret = MIN(DISK_SIZE_ROUND_DOWN(h->disk_size), upper_boundary); else if (h->disk_size_relative == UINT64_MAX) { if (upper_boundary > UINT64_MAX / USER_DISK_SIZE_DEFAULT_PERCENT) return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "Disk size too large."); *ret = DISK_SIZE_ROUND_DOWN(upper_boundary * USER_DISK_SIZE_DEFAULT_PERCENT / 100); log_info("Sizing home to %u%% of available disk space, which is %s.", USER_DISK_SIZE_DEFAULT_PERCENT, FORMAT_BYTES(*ret)); } else { *ret = DISK_SIZE_ROUND_DOWN((uint64_t) ((double) upper_boundary * (double) CLAMP(h->disk_size_relative, 0U, UINT32_MAX) / (double) UINT32_MAX)); log_info("Sizing home to %" PRIu64 ".%01" PRIu64 "%% of available disk space, which is %s.", (h->disk_size_relative * 100) / UINT32_MAX, ((h->disk_size_relative * 1000) / UINT32_MAX) % 10, FORMAT_BYTES(*ret)); } lower_boundary = minimal_size_by_fs_name(fstype); if (lower_boundary != UINT64_MAX) { assert(GPT_LUKS2_OVERHEAD < UINT64_MAX - lower_boundary); lower_boundary += GPT_LUKS2_OVERHEAD; } if (lower_boundary == UINT64_MAX || lower_boundary < USER_DISK_SIZE_MIN) lower_boundary = USER_DISK_SIZE_MIN; if (*ret < lower_boundary) *ret = lower_boundary; return 0; } static int home_truncate( UserRecord *h, int fd, uint64_t size) { bool trunc; int r; assert(h); assert(fd >= 0); trunc = user_record_luks_discard(h); if (!trunc) { r = fallocate(fd, 0, 0, size); if (r < 0 && ERRNO_IS_NOT_SUPPORTED(errno)) { /* Some file systems do not support fallocate(), let's gracefully degrade * (ZFS, reiserfs, …) and fall back to truncation */ log_notice_errno(errno, "Backing file system does not support fallocate(), falling back to ftruncate(), i.e. implicitly using non-discard mode."); trunc = true; } } if (trunc) r = ftruncate(fd, size); if (r < 0) { if (ERRNO_IS_DISK_SPACE(errno)) { log_debug_errno(errno, "Not enough disk space to allocate home of size %s.", FORMAT_BYTES(size)); return -ENOSPC; /* make recognizable */ } return log_error_errno(errno, "Failed to truncate home image: %m"); } return !trunc; /* Return == 0 if we managed to truncate, > 0 if we managed to allocate */ } int home_create_luks( UserRecord *h, HomeSetup *setup, const PasswordCache *cache, char **effective_passwords, UserRecord **ret_home) { _cleanup_free_ char *subdir = NULL, *disk_uuid_path = NULL; uint64_t encrypted_size, host_size = 0, partition_offset = 0, partition_size = 0; /* Unnecessary initialization to appease gcc */ _cleanup_(user_record_unrefp) UserRecord *new_home = NULL; sd_id128_t partition_uuid, fs_uuid, luks_uuid, disk_uuid; _cleanup_close_ int mount_fd = -EBADF; const char *fstype, *ip; struct statfs sfs; int r; _cleanup_strv_free_ char **extra_mkfs_options = NULL; assert(h); assert(h->storage < 0 || h->storage == USER_LUKS); assert(setup); assert(!setup->temporary_image_path); assert(setup->image_fd < 0); assert(ret_home); r = dlopen_cryptsetup(); if (r < 0) return r; assert_se(ip = user_record_image_path(h)); fstype = user_record_file_system_type(h); if (!supported_fstype(fstype)) return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "Unsupported file system type: %s", fstype); r = mkfs_exists(fstype); if (r < 0) return log_error_errno(r, "Failed to check if mkfs binary for %s exists: %m", fstype); if (r == 0) { if (h->file_system_type || streq(fstype, "ext4") || !supported_fstype("ext4")) return log_error_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT), "mkfs binary for file system type %s does not exist.", fstype); /* If the record does not explicitly declare a file system to use, and the compiled-in * default does not actually exist, than do an automatic fallback onto ext4, as the baseline * fs of Linux. We won't search for a working fs type here beyond ext4, i.e. nothing fancier * than a single, conservative fallback to baseline. This should be useful in minimal * environments where mkfs.btrfs or so are not made available, but mkfs.ext4 as Linux' most * boring, most basic fs is. */ log_info("Formatting tool for compiled-in default file system %s not available, falling back to ext4 instead.", fstype); fstype = "ext4"; } if (sd_id128_is_null(h->partition_uuid)) { r = sd_id128_randomize(&partition_uuid); if (r < 0) return log_error_errno(r, "Failed to acquire partition UUID: %m"); } else partition_uuid = h->partition_uuid; if (sd_id128_is_null(h->luks_uuid)) { r = sd_id128_randomize(&luks_uuid); if (r < 0) return log_error_errno(r, "Failed to acquire LUKS UUID: %m"); } else luks_uuid = h->luks_uuid; if (sd_id128_is_null(h->file_system_uuid)) { r = sd_id128_randomize(&fs_uuid); if (r < 0) return log_error_errno(r, "Failed to acquire file system UUID: %m"); } else fs_uuid = h->file_system_uuid; r = make_dm_names(h, setup); if (r < 0) return r; r = access(setup->dm_node, F_OK); if (r < 0) { if (errno != ENOENT) return log_error_errno(errno, "Failed to determine whether %s exists: %m", setup->dm_node); } else return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Device mapper device %s already exists, refusing.", setup->dm_node); if (path_startswith(ip, "/dev/")) { _cleanup_free_ char *sysfs = NULL; uint64_t block_device_size; struct stat st; /* Let's place the home directory on a real device, i.e. a USB stick or such */ setup->image_fd = open_image_file(h, ip, &st); if (setup->image_fd < 0) return setup->image_fd; if (!S_ISBLK(st.st_mode)) return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Device is not a block device, refusing."); if (asprintf(&sysfs, "/sys/dev/block/" DEVNUM_FORMAT_STR "/partition", DEVNUM_FORMAT_VAL(st.st_rdev)) < 0) return log_oom(); if (access(sysfs, F_OK) < 0) { if (errno != ENOENT) return log_error_errno(errno, "Failed to check whether %s exists: %m", sysfs); } else return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Operating on partitions is currently not supported, sorry. Please specify a top-level block device."); if (flock(setup->image_fd, LOCK_EX) < 0) /* make sure udev doesn't read from it while we operate on the device */ return log_error_errno(errno, "Failed to lock block device %s: %m", ip); r = blockdev_get_device_size(setup->image_fd, &block_device_size); if (r < 0) return log_error_errno(r, "Failed to read block device size: %m"); if (h->disk_size == UINT64_MAX) { /* If a relative disk size is requested, apply it relative to the block device size */ if (h->disk_size_relative < UINT32_MAX) host_size = CLAMP(DISK_SIZE_ROUND_DOWN(block_device_size * h->disk_size_relative / UINT32_MAX), USER_DISK_SIZE_MIN, USER_DISK_SIZE_MAX); else host_size = block_device_size; /* Otherwise, take the full device */ } else if (h->disk_size > block_device_size) return log_error_errno(SYNTHETIC_ERRNO(EMSGSIZE), "Selected disk size larger than backing block device, refusing."); else host_size = DISK_SIZE_ROUND_DOWN(h->disk_size); if (!supported_fs_size(fstype, LESS_BY(host_size, GPT_LUKS2_OVERHEAD))) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Selected file system size too small for %s.", fstype); /* After creation we should reference this partition by its UUID instead of the block * device. That's preferable since the user might have specified a device node such as * /dev/sdb to us, which might look very different when replugged. */ if (asprintf(&disk_uuid_path, "/dev/disk/by-uuid/" SD_ID128_UUID_FORMAT_STR, SD_ID128_FORMAT_VAL(luks_uuid)) < 0) return log_oom(); if (user_record_luks_discard(h) || user_record_luks_offline_discard(h)) { /* If we want online or offline discard, discard once before we start using things. */ if (ioctl(setup->image_fd, BLKDISCARD, (uint64_t[]) { 0, block_device_size }) < 0) log_full_errno(errno == EOPNOTSUPP ? LOG_DEBUG : LOG_WARNING, errno, "Failed to issue full-device BLKDISCARD on device, ignoring: %m"); else log_info("Full device discard completed."); } } else { _cleanup_free_ char *t = NULL; r = mkdir_parents(ip, 0755); if (r < 0) return log_error_errno(r, "Failed to create parent directory of %s: %m", ip); r = tempfn_random(ip, "homework", &t); if (r < 0) return log_error_errno(r, "Failed to derive temporary file name for %s: %m", ip); setup->image_fd = open(t, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600); if (setup->image_fd < 0) return log_error_errno(errno, "Failed to create home image %s: %m", t); setup->temporary_image_path = TAKE_PTR(t); r = chattr_full(setup->image_fd, NULL, FS_NOCOW_FL|FS_NOCOMP_FL, FS_NOCOW_FL|FS_NOCOMP_FL, NULL, NULL, CHATTR_FALLBACK_BITWISE); if (r < 0 && r != -ENOANO) /* ENOANO → some bits didn't work; which we skip logging about because chattr_full() already debug logs about those flags */ log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set file attributes on %s, ignoring: %m", setup->temporary_image_path); r = calculate_initial_image_size(h, setup->image_fd, fstype, &host_size); if (r < 0) return r; r = resize_image_loop(h, setup, 0, host_size, &host_size); if (r < 0) return r; log_info("Allocating image file completed."); } r = make_partition_table( setup->image_fd, user_record_luks_sector_size(h), user_record_user_name_and_realm(h), partition_uuid, &partition_offset, &partition_size, &disk_uuid); if (r < 0) return r; log_info("Writing of partition table completed."); r = loop_device_make( setup->image_fd, O_RDWR, partition_offset, partition_size, user_record_luks_sector_size(h), 0, LOCK_EX, &setup->loop); if (r < 0) { if (r == -ENOENT) { /* this means /dev/loop-control doesn't exist, i.e. we are in a container * or similar and loopback bock devices are not available, return a * recognizable error in this case. */ log_error_errno(r, "Loopback block device support is not available on this system."); return -ENOLINK; /* Make recognizable */ } return log_error_errno(r, "Failed to set up loopback device for %s: %m", setup->temporary_image_path); } log_info("Setting up loopback device %s completed.", setup->loop->node ?: ip); r = luks_format(setup->loop->node, setup->dm_name, luks_uuid, user_record_user_name_and_realm(h), cache, effective_passwords, user_record_luks_discard(h) || user_record_luks_offline_discard(h), h, &setup->crypt_device); if (r < 0) return r; setup->undo_dm = true; r = block_get_size_by_path(setup->dm_node, &encrypted_size); if (r < 0) return log_error_errno(r, "Failed to get encrypted block device size: %m"); log_info("Setting up LUKS device %s completed.", setup->dm_node); r = mkfs_options_from_env("HOME", fstype, &extra_mkfs_options); if (r < 0) return log_error_errno(r, "Failed to determine mkfs command line options for '%s': %m", fstype); r = make_filesystem(setup->dm_node, fstype, user_record_user_name_and_realm(h), /* root = */ NULL, fs_uuid, user_record_luks_discard(h), /* quiet = */ true, /* sector_size = */ 0, /* compression = */ NULL, /* compression_level= */ NULL, extra_mkfs_options); if (r < 0) return r; log_info("Formatting file system completed."); r = home_unshare_and_mount(setup->dm_node, fstype, user_record_luks_discard(h), user_record_mount_flags(h), h->luks_extra_mount_options); if (r < 0) return r; setup->undo_mount = true; subdir = path_join(HOME_RUNTIME_WORK_DIR, user_record_user_name_and_realm(h)); if (!subdir) return log_oom(); /* Prefer using a btrfs subvolume if we can, fall back to directory otherwise */ r = btrfs_subvol_make_fallback(AT_FDCWD, subdir, 0700); if (r < 0) return log_error_errno(r, "Failed to create user directory in mounted image file: %m"); setup->root_fd = open(subdir, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (setup->root_fd < 0) return log_error_errno(errno, "Failed to open user directory in mounted image file: %m"); (void) home_shift_uid(setup->root_fd, NULL, UID_NOBODY, h->uid, &mount_fd); if (mount_fd >= 0) { /* If we have established a new mount, then we can use that as new root fd to our home directory. */ safe_close(setup->root_fd); setup->root_fd = fd_reopen(mount_fd, O_RDONLY|O_CLOEXEC|O_DIRECTORY); if (setup->root_fd < 0) return log_error_errno(setup->root_fd, "Unable to convert mount fd into proper directory fd: %m"); mount_fd = safe_close(mount_fd); } r = home_populate(h, setup->root_fd); if (r < 0) return r; r = home_sync_and_statfs(setup->root_fd, &sfs); if (r < 0) return r; r = user_record_clone(h, USER_RECORD_LOAD_MASK_SECRET|USER_RECORD_LOG|USER_RECORD_PERMISSIVE, &new_home); if (r < 0) return log_error_errno(r, "Failed to clone record: %m"); r = user_record_add_binding( new_home, USER_LUKS, disk_uuid_path ?: ip, partition_uuid, luks_uuid, fs_uuid, sym_crypt_get_cipher(setup->crypt_device), sym_crypt_get_cipher_mode(setup->crypt_device), luks_volume_key_size_convert(setup->crypt_device), fstype, NULL, h->uid, (gid_t) h->uid); if (r < 0) return log_error_errno(r, "Failed to add binding to record: %m"); if (user_record_luks_offline_discard(h)) { r = run_fitrim(setup->root_fd); if (r < 0) return r; } setup->root_fd = safe_close(setup->root_fd); r = home_setup_undo_mount(setup, LOG_ERR); if (r < 0) return r; r = home_setup_undo_dm(setup, LOG_ERR); if (r < 0) return r; setup->loop = loop_device_unref(setup->loop); if (!user_record_luks_offline_discard(h)) { r= run_fallocate(setup->image_fd, NULL /* refresh stat() data */); if (r < 0) return r; } /* Sync everything to disk before we move things into place under the final name. */ if (fsync(setup->image_fd) < 0) return log_error_errno(r, "Failed to synchronize image to disk: %m"); if (disk_uuid_path) /* Reread partition table if this is a block device */ (void) ioctl(setup->image_fd, BLKRRPART, 0); else { assert(setup->temporary_image_path); if (rename(setup->temporary_image_path, ip) < 0) return log_error_errno(errno, "Failed to rename image file: %m"); setup->temporary_image_path = mfree(setup->temporary_image_path); /* If we operate on a file, sync the containing directory too. */ r = fsync_directory_of_file(setup->image_fd); if (r < 0) return log_error_errno(r, "Failed to synchronize directory of image file to disk: %m"); log_info("Moved image file into place."); } /* Let's close the image fd now. If we are operating on a real block device this will release the BSD * lock that ensures udev doesn't interfere with what we are doing */ setup->image_fd = safe_close(setup->image_fd); if (disk_uuid_path) (void) wait_for_devlink(disk_uuid_path); log_info("Creation completed."); print_size_summary(host_size, encrypted_size, &sfs); log_debug("GPT + LUKS2 overhead is %" PRIu64 " (expected %" PRIu64 ")", host_size - encrypted_size, GPT_LUKS2_OVERHEAD); *ret_home = TAKE_PTR(new_home); return 0; } int home_get_state_luks(UserRecord *h, HomeSetup *setup) { int r; assert(h); assert(setup); r = make_dm_names(h, setup); if (r < 0) return r; r = access(setup->dm_node, F_OK); if (r < 0 && errno != ENOENT) return log_error_errno(errno, "Failed to determine whether %s exists: %m", setup->dm_node); return r >= 0; } enum { CAN_RESIZE_ONLINE, CAN_RESIZE_OFFLINE, }; static int can_resize_fs(int fd, uint64_t old_size, uint64_t new_size) { struct statfs sfs; assert(fd >= 0); /* Filter out bogus requests early */ if (old_size == 0 || old_size == UINT64_MAX || new_size == 0 || new_size == UINT64_MAX) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid resize parameters."); if ((old_size & 511) != 0 || (new_size & 511) != 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Resize parameters not multiple of 512."); if (fstatfs(fd, &sfs) < 0) return log_error_errno(errno, "Failed to fstatfs() file system: %m"); if (is_fs_type(&sfs, BTRFS_SUPER_MAGIC)) { if (new_size < BTRFS_MINIMAL_SIZE) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for btrfs (needs to be 256M at least."); /* btrfs can grow and shrink online */ } else if (is_fs_type(&sfs, XFS_SUPER_MAGIC)) { if (new_size < XFS_MINIMAL_SIZE) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for xfs (needs to be 14M at least)."); /* XFS can grow, but not shrink */ if (new_size < old_size) return log_error_errno(SYNTHETIC_ERRNO(EMSGSIZE), "Shrinking this type of file system is not supported."); } else if (is_fs_type(&sfs, EXT4_SUPER_MAGIC)) { if (new_size < EXT4_MINIMAL_SIZE) return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "New file system size too small for ext4 (needs to be 1M at least)."); /* ext4 can grow online, and shrink offline */ if (new_size < old_size) return CAN_RESIZE_OFFLINE; } else return log_error_errno(SYNTHETIC_ERRNO(ESOCKTNOSUPPORT), "Resizing this type of file system is not supported."); return CAN_RESIZE_ONLINE; } static int ext4_offline_resize_fs( HomeSetup *setup, uint64_t new_size, bool discard, unsigned long flags, const char *extra_mount_options) { _cleanup_free_ char *size_str = NULL; bool re_open = false, re_mount = false; pid_t resize_pid, fsck_pid; int r, exit_status; assert(setup); assert(setup->dm_node); /* First, unmount the file system */ if (setup->root_fd >= 0) { setup->root_fd = safe_close(setup->root_fd); re_open = true; } if (setup->undo_mount) { r = home_setup_undo_mount(setup, LOG_ERR); if (r < 0) return r; re_mount = true; } log_info("Temporary unmounting of file system completed."); /* resize2fs requires that the file system is force checked first, do so. */ r = safe_fork("(e2fsck)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_STDOUT_TO_STDERR|FORK_CLOSE_ALL_FDS, &fsck_pid); if (r < 0) return r; if (r == 0) { /* Child */ execlp("e2fsck", "e2fsck", "-fp", setup->dm_node, NULL); log_open(); log_error_errno(errno, "Failed to execute e2fsck: %m"); _exit(EXIT_FAILURE); } exit_status = wait_for_terminate_and_check("e2fsck", fsck_pid, WAIT_LOG_ABNORMAL); if (exit_status < 0) return exit_status; if ((exit_status & ~FSCK_ERROR_CORRECTED) != 0) { log_warning("e2fsck failed with exit status %i.", exit_status); if ((exit_status & (FSCK_SYSTEM_SHOULD_REBOOT|FSCK_ERRORS_LEFT_UNCORRECTED)) != 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "File system is corrupted, refusing."); log_warning("Ignoring fsck error."); } log_info("Forced file system check completed."); /* We use 512 sectors here, because resize2fs doesn't do byte sizes */ if (asprintf(&size_str, "%" PRIu64 "s", new_size / 512) < 0) return log_oom(); /* Resize the thing */ r = safe_fork("(e2resize)", FORK_RESET_SIGNALS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_WAIT|FORK_STDOUT_TO_STDERR|FORK_CLOSE_ALL_FDS, &resize_pid); if (r < 0) return r; if (r == 0) { /* Child */ execlp("resize2fs", "resize2fs", setup->dm_node, size_str, NULL); log_open(); log_error_errno(errno, "Failed to execute resize2fs: %m"); _exit(EXIT_FAILURE); } log_info("Offline file system resize completed."); /* Re-establish mounts and reopen the directory */ if (re_mount) { r = home_mount_node(setup->dm_node, "ext4", discard, flags, extra_mount_options); if (r < 0) return r; setup->undo_mount = true; } if (re_open) { setup->root_fd = open(HOME_RUNTIME_WORK_DIR, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (setup->root_fd < 0) return log_error_errno(errno, "Failed to reopen file system: %m"); } log_info("File system mounted again."); return 0; } static int prepare_resize_partition( int fd, uint64_t partition_offset, uint64_t old_partition_size, sd_id128_t *ret_disk_uuid, struct fdisk_table **ret_table, struct fdisk_partition **ret_partition) { _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; _cleanup_(fdisk_unref_tablep) struct fdisk_table *t = NULL; _cleanup_free_ char *disk_uuid_as_string = NULL; struct fdisk_partition *found = NULL; sd_id128_t disk_uuid; size_t n_partitions; int r; assert(fd >= 0); assert(ret_disk_uuid); assert(ret_table); assert((partition_offset & 511) == 0); assert((old_partition_size & 511) == 0); assert(UINT64_MAX - old_partition_size >= partition_offset); if (partition_offset == 0) { /* If the offset is at the beginning we assume no partition table, let's exit early. */ log_debug("Not rewriting partition table, operating on naked device."); *ret_disk_uuid = SD_ID128_NULL; *ret_table = NULL; *ret_partition = NULL; return 0; } r = fdisk_new_context_at(fd, /* path= */ NULL, /* read_only= */ false, UINT32_MAX, &c); if (r < 0) return log_error_errno(r, "Failed to open device: %m"); if (!fdisk_is_labeltype(c, FDISK_DISKLABEL_GPT)) return log_error_errno(SYNTHETIC_ERRNO(ENOMEDIUM), "Disk has no GPT partition table."); r = fdisk_get_disklabel_id(c, &disk_uuid_as_string); if (r < 0) return log_error_errno(r, "Failed to acquire disk UUID: %m"); r = sd_id128_from_string(disk_uuid_as_string, &disk_uuid); if (r < 0) return log_error_errno(r, "Failed parse disk UUID: %m"); r = fdisk_get_partitions(c, &t); if (r < 0) return log_error_errno(r, "Failed to acquire partition table: %m"); n_partitions = fdisk_table_get_nents(t); for (size_t i = 0; i < n_partitions; i++) { struct fdisk_partition *p; p = fdisk_table_get_partition(t, i); if (!p) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to read partition metadata."); if (fdisk_partition_is_used(p) <= 0) continue; if (fdisk_partition_has_start(p) <= 0 || fdisk_partition_has_size(p) <= 0 || fdisk_partition_has_end(p) <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Found partition without a size."); if (fdisk_partition_get_start(p) == partition_offset / 512U && fdisk_partition_get_size(p) == old_partition_size / 512U) { if (found) return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ), "Partition found twice, refusing."); found = p; } else if (fdisk_partition_get_end(p) > partition_offset / 512U) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Can't extend, not last partition in image."); } if (!found) return log_error_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to find matching partition to resize."); *ret_disk_uuid = disk_uuid; *ret_table = TAKE_PTR(t); *ret_partition = found; return 1; } static int get_maximum_partition_size( int fd, struct fdisk_partition *p, uint64_t *ret_maximum_partition_size) { _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; uint64_t start_lba, start, last_lba, end; int r; assert(fd >= 0); assert(p); assert(ret_maximum_partition_size); r = fdisk_new_context_at(fd, /* path= */ NULL, /* read_only= */ true, /* sector_size= */ UINT32_MAX, &c); if (r < 0) return log_error_errno(r, "Failed to create fdisk context: %m"); start_lba = fdisk_partition_get_start(p); assert(start_lba <= UINT64_MAX/512); start = start_lba * 512; last_lba = fdisk_get_last_lba(c); /* One sector before boundary where usable space ends */ assert(last_lba < UINT64_MAX/512); end = DISK_SIZE_ROUND_DOWN((last_lba + 1) * 512); /* Round down to multiple of 4K */ if (start > end) return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Last LBA is before partition start."); *ret_maximum_partition_size = DISK_SIZE_ROUND_DOWN(end - start); return 1; } static int ask_cb(struct fdisk_context *c, struct fdisk_ask *ask, void *userdata) { char *result; assert(c); switch (fdisk_ask_get_type(ask)) { case FDISK_ASKTYPE_STRING: result = new(char, 37); if (!result) return log_oom(); fdisk_ask_string_set_result(ask, sd_id128_to_uuid_string(*(sd_id128_t*) userdata, result)); break; default: log_debug("Unexpected question from libfdisk, ignoring."); } return 0; } static int apply_resize_partition( int fd, sd_id128_t disk_uuids, struct fdisk_table *t, struct fdisk_partition *p, size_t new_partition_size) { _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; _cleanup_free_ void *two_zero_lbas = NULL; uint32_t ssz; ssize_t n; int r; assert(fd >= 0); assert(!t == !p); if (!t) /* no partition table to apply, exit early */ return 0; assert(p); /* Before writing our partition patch the final size in */ r = fdisk_partition_size_explicit(p, 1); if (r < 0) return log_error_errno(r, "Failed to enable explicit partition size: %m"); r = fdisk_partition_set_size(p, new_partition_size / 512U); if (r < 0) return log_error_errno(r, "Failed to change partition size: %m"); r = probe_sector_size(fd, &ssz); if (r < 0) return log_error_errno(r, "Failed to determine current sector size: %m"); two_zero_lbas = malloc0(ssz * 2); if (!two_zero_lbas) return log_oom(); /* libfdisk appears to get confused by the existing PMBR. Let's explicitly flush it out. */ n = pwrite(fd, two_zero_lbas, ssz * 2, 0); if (n < 0) return log_error_errno(errno, "Failed to wipe partition table: %m"); if ((size_t) n != ssz * 2) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while wiping partition table."); r = fdisk_new_context_at(fd, /* path= */ NULL, /* read_only= */ false, ssz, &c); if (r < 0) return log_error_errno(r, "Failed to open device: %m"); r = fdisk_create_disklabel(c, "gpt"); if (r < 0) return log_error_errno(r, "Failed to create GPT disk label: %m"); r = fdisk_apply_table(c, t); if (r < 0) return log_error_errno(r, "Failed to apply partition table: %m"); r = fdisk_set_ask(c, ask_cb, &disk_uuids); if (r < 0) return log_error_errno(r, "Failed to set libfdisk query function: %m"); r = fdisk_set_disklabel_id(c); if (r < 0) return log_error_errno(r, "Failed to change disklabel ID: %m"); r = fdisk_write_disklabel(c); if (r < 0) return log_error_errno(r, "Failed to write disk label: %m"); return 1; } /* Always keep at least 16M free, so that we can safely log in and update the user record while doing so */ #define HOME_MIN_FREE (16U*1024U*1024U) static int get_smallest_fs_size(int fd, uint64_t *ret) { uint64_t minsz, needed; struct statfs sfs; assert(fd >= 0); assert(ret); /* Determines the minimal disk size we might be able to shrink the file system referenced by the fd to. */ if (syncfs(fd) < 0) /* let's sync before we query the size, so that the values returned are accurate */ return log_error_errno(errno, "Failed to synchronize home file system: %m"); if (fstatfs(fd, &sfs) < 0) return log_error_errno(errno, "Failed to statfs() home file system: %m"); /* Let's determine the minimal file system size of the used fstype */ minsz = minimal_size_by_fs_magic(sfs.f_type); if (minsz == UINT64_MAX) return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Don't know minimum file system size of file system type '%s' of home directory.", fs_type_to_string(sfs.f_type)); if (minsz < USER_DISK_SIZE_MIN) minsz = USER_DISK_SIZE_MIN; if (sfs.f_bfree > sfs.f_blocks) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Detected amount of free blocks is greater than the total amount of file system blocks. Refusing."); /* Calculate how much disk space is currently in use. */ needed = sfs.f_blocks - sfs.f_bfree; if (needed > UINT64_MAX / sfs.f_bsize) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "File system size out of range."); needed *= sfs.f_bsize; /* Add some safety margin of free space we'll always keep */ if (needed > UINT64_MAX - HOME_MIN_FREE) /* Check for overflow */ needed = UINT64_MAX; else needed += HOME_MIN_FREE; *ret = DISK_SIZE_ROUND_UP(MAX(needed, minsz)); return 0; } static int get_largest_image_size(int fd, const struct stat *st, uint64_t *ret) { uint64_t used, avail, sum; struct statfs sfs; int r; assert(fd >= 0); assert(st); assert(ret); /* Determines the maximum file size we might be able to grow the image file referenced by the fd to. */ r = stat_verify_regular(st); if (r < 0) return log_error_errno(r, "Image file is not a regular file, refusing: %m"); if (syncfs(fd) < 0) return log_error_errno(errno, "Failed to synchronize file system backing image file: %m"); if (fstatfs(fd, &sfs) < 0) return log_error_errno(errno, "Failed to statfs() image file: %m"); used = (uint64_t) st->st_blocks * 512; avail = (uint64_t) sfs.f_bsize * sfs.f_bavail; if (avail > UINT64_MAX - used) sum = UINT64_MAX; else sum = avail + used; *ret = DISK_SIZE_ROUND_DOWN(MIN(sum, USER_DISK_SIZE_MAX)); return 0; } static int resize_fs_loop( UserRecord *h, HomeSetup *setup, int resize_type, uint64_t old_fs_size, uint64_t new_fs_size, uint64_t *ret_fs_size) { uint64_t current_fs_size; unsigned n_iterations = 0; int r; assert(h); assert(setup); assert(setup->root_fd >= 0); /* A bisection loop trying to find the closest size to what the user asked for. (Well, we bisect like * this only when we *shrink* the fs — if we grow the fs there's no need to bisect.) */ current_fs_size = old_fs_size; for (uint64_t lower_boundary = new_fs_size, upper_boundary = old_fs_size, try_fs_size = new_fs_size;;) { bool worked; n_iterations++; /* Now resize the file system */ if (resize_type == CAN_RESIZE_ONLINE) { r = resize_fs(setup->root_fd, try_fs_size, NULL); if (r < 0) { if (!ERRNO_IS_DISK_SPACE(r) || new_fs_size > old_fs_size) /* Not a disk space issue? Not trying to shrink? */ return log_error_errno(r, "Failed to resize file system: %m"); log_debug_errno(r, "Shrinking from %s to %s didn't work, not enough space for contained data.", FORMAT_BYTES(current_fs_size), FORMAT_BYTES(try_fs_size)); worked = false; } else { log_debug("Successfully resized from %s to %s.", FORMAT_BYTES(current_fs_size), FORMAT_BYTES(try_fs_size)); current_fs_size = try_fs_size; worked = true; } /* If we hit a disk space issue and are shrinking the fs, then maybe it helps to * increase the image size. */ } else { r = ext4_offline_resize_fs(setup, try_fs_size, user_record_luks_discard(h), user_record_mount_flags(h), h->luks_extra_mount_options); if (r < 0) return r; /* For now, when we fail to shrink an ext4 image we'll not try again via the * bisection logic. We might add that later, but given this involves shelling out * multiple programs, it's a bit too cumbersome for my taste. */ worked = true; current_fs_size = try_fs_size; } if (new_fs_size > old_fs_size) /* If we are growing we are done after one iteration */ break; /* If we are shrinking then let's adjust our bisection boundaries and try again. */ if (worked) upper_boundary = MIN(upper_boundary, try_fs_size); else lower_boundary = MAX(lower_boundary, try_fs_size); /* OK, this attempt to shrink didn't work. Let's try between the old size and what worked. */ if (lower_boundary >= upper_boundary) { log_debug("Image can't be shrunk further (range to try is empty)."); break; } /* Let's find a new value to try half-way between the lower boundary and the upper boundary * to try now. */ try_fs_size = DISK_SIZE_ROUND_DOWN(lower_boundary + (upper_boundary - lower_boundary) / 2); if (try_fs_size <= lower_boundary || try_fs_size >= upper_boundary) { log_debug("Image can't be shrunk further (remaining range to try too small)."); break; } } log_debug("Bisection loop completed after %u iterations.", n_iterations); if (ret_fs_size) *ret_fs_size = current_fs_size; return 0; } static int resize_image_loop( UserRecord *h, HomeSetup *setup, uint64_t old_image_size, uint64_t new_image_size, uint64_t *ret_image_size) { uint64_t current_image_size; unsigned n_iterations = 0; int r; assert(h); assert(setup); assert(setup->image_fd >= 0); /* A bisection loop trying to find the closest size to what the user asked for. (Well, we bisect like * this only when we *grow* the image — if we shrink the image then there's no need to bisect.) */ current_image_size = old_image_size; for (uint64_t lower_boundary = old_image_size, upper_boundary = new_image_size, try_image_size = new_image_size;;) { bool worked; n_iterations++; r = home_truncate(h, setup->image_fd, try_image_size); if (r < 0) { if (!ERRNO_IS_DISK_SPACE(r) || new_image_size < old_image_size) /* Not a disk space issue? Not trying to grow? */ return r; log_debug_errno(r, "Growing from %s to %s didn't work, not enough space on backing disk.", FORMAT_BYTES(current_image_size), FORMAT_BYTES(try_image_size)); worked = false; } else if (r > 0) { /* Success: allocation worked */ log_debug("Resizing from %s to %s via allocation worked successfully.", FORMAT_BYTES(current_image_size), FORMAT_BYTES(try_image_size)); current_image_size = try_image_size; worked = true; } else { /* Success, but through truncation, not allocation. */ log_debug("Resizing from %s to %s via truncation worked successfully.", FORMAT_BYTES(old_image_size), FORMAT_BYTES(try_image_size)); current_image_size = try_image_size; break; /* there's no point in the bisection logic if this was plain truncation and * not allocation, let's exit immediately. */ } if (new_image_size < old_image_size) /* If we are shrinking we are done after one iteration */ break; /* If we are growing then let's adjust our bisection boundaries and try again */ if (worked) lower_boundary = MAX(lower_boundary, try_image_size); else upper_boundary = MIN(upper_boundary, try_image_size); if (lower_boundary >= upper_boundary) { log_debug("Image can't be grown further (range to try is empty)."); break; } try_image_size = DISK_SIZE_ROUND_DOWN(lower_boundary + (upper_boundary - lower_boundary) / 2); if (try_image_size <= lower_boundary || try_image_size >= upper_boundary) { log_debug("Image can't be grown further (remaining range to try too small)."); break; } } log_debug("Bisection loop completed after %u iterations.", n_iterations); if (ret_image_size) *ret_image_size = current_image_size; return 0; } int home_resize_luks( UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, PasswordCache *cache, UserRecord **ret_home) { uint64_t old_image_size, new_image_size, old_fs_size, new_fs_size, crypto_offset, crypto_offset_bytes, new_partition_size, smallest_fs_size, resized_fs_size; _cleanup_(user_record_unrefp) UserRecord *header_home = NULL, *embedded_home = NULL, *new_home = NULL; _cleanup_(fdisk_unref_tablep) struct fdisk_table *table = NULL; struct fdisk_partition *partition = NULL; _cleanup_close_ int opened_image_fd = -EBADF; _cleanup_free_ char *whole_disk = NULL; int r, resize_type, image_fd = -EBADF, reconciled = USER_RECONCILE_IDENTICAL; sd_id128_t disk_uuid; const char *ip, *ipo; struct statfs sfs; struct stat st; enum { INTENTION_DONT_KNOW = 0, /* These happen to match the return codes of CMP() */ INTENTION_SHRINK = -1, INTENTION_GROW = 1, } intention = INTENTION_DONT_KNOW; assert(h); assert(user_record_storage(h) == USER_LUKS); assert(setup); r = dlopen_cryptsetup(); if (r < 0) return r; assert_se(ipo = user_record_image_path(h)); ip = strdupa_safe(ipo); /* copy out since original might change later in home record object */ if (setup->image_fd < 0) { setup->image_fd = open_image_file(h, NULL, &st); if (setup->image_fd < 0) return setup->image_fd; } else { if (fstat(setup->image_fd, &st) < 0) return log_error_errno(errno, "Failed to stat image file %s: %m", ip); } image_fd = setup->image_fd; if (S_ISBLK(st.st_mode)) { dev_t parent; r = block_get_whole_disk(st.st_rdev, &parent); if (r < 0) return log_error_errno(r, "Failed to acquire whole block device for %s: %m", ip); if (r > 0) { /* If we shall resize a file system on a partition device, then let's figure out the * whole disk device and operate on that instead, since we need to rewrite the * partition table to resize the partition. */ log_info("Operating on partition device %s, using parent device.", ip); opened_image_fd = r = device_open_from_devnum(S_IFBLK, parent, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK, &whole_disk); if (r < 0) return log_error_errno(r, "Failed to open whole block device for %s: %m", ip); image_fd = opened_image_fd; if (fstat(image_fd, &st) < 0) return log_error_errno(errno, "Failed to stat whole block device %s: %m", whole_disk); } else log_info("Operating on whole block device %s.", ip); r = blockdev_get_device_size(image_fd, &old_image_size); if (r < 0) return log_error_errno(r, "Failed to determine size of original block device: %m"); if (flock(image_fd, LOCK_EX) < 0) /* make sure udev doesn't read from it while we operate on the device */ return log_error_errno(errno, "Failed to lock block device %s: %m", ip); new_image_size = old_image_size; /* we can't resize physical block devices */ } else { r = stat_verify_regular(&st); if (r < 0) return log_error_errno(r, "Image %s is not a block device nor regular file: %m", ip); old_image_size = st.st_size; /* Note an asymmetry here: when we operate on loopback files the specified disk size we get we * apply onto the loopback file as a whole. When we operate on block devices we instead apply * to the partition itself only. */ if (FLAGS_SET(flags, HOME_SETUP_RESIZE_MINIMIZE)) { new_image_size = 0; intention = INTENTION_SHRINK; } else { uint64_t new_image_size_rounded; new_image_size_rounded = DISK_SIZE_ROUND_DOWN(h->disk_size); if (old_image_size >= new_image_size_rounded && old_image_size <= h->disk_size) { /* If exact match, or a match after we rounded down, don't do a thing */ log_info("Image size already matching, skipping operation."); return 0; } new_image_size = new_image_size_rounded; intention = CMP(new_image_size, old_image_size); /* Is this a shrink */ } } r = home_setup_luks( h, flags, whole_disk, setup, cache, FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES) ? NULL : &header_home); if (r < 0) return r; if (!FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES)) { reconciled = home_load_embedded_identity(h, setup->root_fd, header_home, USER_RECONCILE_REQUIRE_NEWER_OR_EQUAL, cache, &embedded_home, &new_home); if (reconciled < 0) return reconciled; } r = home_maybe_shift_uid(h, flags, setup); if (r < 0) return r; log_info("offset = %" PRIu64 ", size = %" PRIu64 ", image = %" PRIu64, setup->partition_offset, setup->partition_size, old_image_size); if ((UINT64_MAX - setup->partition_offset) < setup->partition_size || setup->partition_offset + setup->partition_size > old_image_size) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Old partition doesn't fit in backing storage, refusing."); /* Get target partition information in here for new_partition_size calculation */ r = prepare_resize_partition( image_fd, setup->partition_offset, setup->partition_size, &disk_uuid, &table, &partition); if (r < 0) return r; if (S_ISREG(st.st_mode)) { uint64_t partition_table_extra, largest_size; partition_table_extra = old_image_size - setup->partition_size; r = get_largest_image_size(setup->image_fd, &st, &largest_size); if (r < 0) return r; if (new_image_size > largest_size) new_image_size = largest_size; if (new_image_size < partition_table_extra) new_image_size = partition_table_extra; new_partition_size = DISK_SIZE_ROUND_DOWN(new_image_size - partition_table_extra); } else { assert(S_ISBLK(st.st_mode)); if (FLAGS_SET(flags, HOME_SETUP_RESIZE_MINIMIZE)) { new_partition_size = 0; intention = INTENTION_SHRINK; } else { uint64_t new_partition_size_rounded = DISK_SIZE_ROUND_DOWN(h->disk_size); if (h->disk_size == UINT64_MAX && partition) { r = get_maximum_partition_size(image_fd, partition, &new_partition_size_rounded); if (r < 0) return r; } if (setup->partition_size >= new_partition_size_rounded && setup->partition_size <= h->disk_size) { log_info("Partition size already matching, skipping operation."); return 0; } new_partition_size = new_partition_size_rounded; intention = CMP(new_partition_size, setup->partition_size); } } if ((UINT64_MAX - setup->partition_offset) < new_partition_size || setup->partition_offset + new_partition_size > new_image_size) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New partition doesn't fit into backing storage, refusing."); crypto_offset = sym_crypt_get_data_offset(setup->crypt_device); if (crypto_offset > UINT64_MAX/512U) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS2 data offset out of range, refusing."); crypto_offset_bytes = (uint64_t) crypto_offset * 512U; if (setup->partition_size <= crypto_offset_bytes) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Weird, old crypto payload offset doesn't actually fit in partition size?"); /* Make sure at least the LUKS header fit in */ if (new_partition_size <= crypto_offset_bytes) { uint64_t add; add = DISK_SIZE_ROUND_UP(crypto_offset_bytes) - new_partition_size; new_partition_size += add; if (S_ISREG(st.st_mode)) new_image_size += add; } old_fs_size = setup->partition_size - crypto_offset_bytes; new_fs_size = DISK_SIZE_ROUND_DOWN(new_partition_size - crypto_offset_bytes); r = get_smallest_fs_size(setup->root_fd, &smallest_fs_size); if (r < 0) return r; if (new_fs_size < smallest_fs_size) { uint64_t add; add = DISK_SIZE_ROUND_UP(smallest_fs_size) - new_fs_size; new_fs_size += add; new_partition_size += add; if (S_ISREG(st.st_mode)) new_image_size += add; } if (new_fs_size == old_fs_size) { log_info("New file system size identical to old file system size, skipping operation."); return 0; } if (FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_GROW) && new_fs_size > old_fs_size) { log_info("New file system size would be larger than old, but shrinking requested, skipping operation."); return 0; } if (FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SHRINK) && new_fs_size < old_fs_size) { log_info("New file system size would be smaller than old, but growing requested, skipping operation."); return 0; } if (CMP(new_fs_size, old_fs_size) != intention) { if (intention < 0) log_info("Shrink operation would enlarge file system, skipping operation."); else { assert(intention > 0); log_info("Grow operation would shrink file system, skipping operation."); } return 0; } /* Before we start doing anything, let's figure out if we actually can */ resize_type = can_resize_fs(setup->root_fd, old_fs_size, new_fs_size); if (resize_type < 0) return resize_type; if (resize_type == CAN_RESIZE_OFFLINE && FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) return log_error_errno(SYNTHETIC_ERRNO(ETXTBSY), "File systems of this type can only be resized offline, but is currently online."); log_info("Ready to resize image size %s %s %s, partition size %s %s %s, file system size %s %s %s.", FORMAT_BYTES(old_image_size), special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), FORMAT_BYTES(new_image_size), FORMAT_BYTES(setup->partition_size), special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), FORMAT_BYTES(new_partition_size), FORMAT_BYTES(old_fs_size), special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), FORMAT_BYTES(new_fs_size)); if (new_fs_size > old_fs_size) { /* → Grow */ if (S_ISREG(st.st_mode)) { uint64_t resized_image_size; /* Grow file size */ r = resize_image_loop(h, setup, old_image_size, new_image_size, &resized_image_size); if (r < 0) return r; if (resized_image_size == old_image_size) { log_info("Couldn't change image size."); return 0; } assert(resized_image_size > old_image_size); log_info("Growing of image file from %s to %s completed.", FORMAT_BYTES(old_image_size), FORMAT_BYTES(resized_image_size)); if (resized_image_size < new_image_size) { uint64_t sub; /* If the growing we managed to do is smaller than what we wanted we need to * adjust the partition/file system sizes we are going for, too */ sub = new_image_size - resized_image_size; assert(new_partition_size >= sub); new_partition_size -= sub; assert(new_fs_size >= sub); new_fs_size -= sub; } new_image_size = resized_image_size; } else { assert(S_ISBLK(st.st_mode)); assert(new_image_size == old_image_size); } /* Make sure loopback device sees the new bigger size */ r = loop_device_refresh_size(setup->loop, UINT64_MAX, new_partition_size); if (r == -ENOTTY) log_debug_errno(r, "Device is not a loopback device, not refreshing size."); else if (r < 0) return log_error_errno(r, "Failed to refresh loopback device size: %m"); else log_info("Refreshing loop device size completed."); r = apply_resize_partition(image_fd, disk_uuid, table, partition, new_partition_size); if (r < 0) return r; if (r > 0) log_info("Growing of partition completed."); if (S_ISBLK(st.st_mode) && ioctl(image_fd, BLKRRPART, 0) < 0) log_debug_errno(errno, "BLKRRPART failed on block device, ignoring: %m"); /* Tell LUKS about the new bigger size too */ r = sym_crypt_resize(setup->crypt_device, setup->dm_name, new_fs_size / 512U); if (r < 0) return log_error_errno(r, "Failed to grow LUKS device: %m"); log_info("LUKS device growing completed."); } else { /* → Shrink */ if (!FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES)) { r = home_store_embedded_identity(new_home, setup->root_fd, embedded_home); if (r < 0) return r; r = home_reconcile_blob_dirs(new_home, setup->root_fd, reconciled); if (r < 0) return r; } if (S_ISREG(st.st_mode)) { if (user_record_luks_discard(h)) /* Before we shrink, let's trim the file system, so that we need less space on disk during the shrinking */ (void) run_fitrim(setup->root_fd); else { /* If discard is off, let's ensure all backing blocks are allocated, so that our resize operation doesn't fail half-way */ r = run_fallocate(image_fd, &st); if (r < 0) return r; } } } /* Now try to resize the file system. The requested size might not always be possible, in which case * we'll try to get as close as we can get. The result is returned in 'resized_fs_size' */ r = resize_fs_loop(h, setup, resize_type, old_fs_size, new_fs_size, &resized_fs_size); if (r < 0) return r; if (resized_fs_size == old_fs_size) { log_info("Couldn't change file system size."); return 0; } log_info("File system resizing from %s to %s completed.", FORMAT_BYTES(old_fs_size), FORMAT_BYTES(resized_fs_size)); if (resized_fs_size > new_fs_size) { uint64_t add; /* If the shrinking we managed to do is larger than what we wanted we need to adjust the partition/image sizes. */ add = resized_fs_size - new_fs_size; new_partition_size += add; if (S_ISREG(st.st_mode)) new_image_size += add; } new_fs_size = resized_fs_size; /* Immediately sync afterwards */ r = home_sync_and_statfs(setup->root_fd, NULL); if (r < 0) return r; if (new_fs_size < old_fs_size) { /* → Shrink */ /* Shrink the LUKS device now, matching the new file system size */ r = sym_crypt_resize(setup->crypt_device, setup->dm_name, new_fs_size / 512); if (r < 0) return log_error_errno(r, "Failed to shrink LUKS device: %m"); log_info("LUKS device shrinking completed."); /* Refresh the loop devices size */ r = loop_device_refresh_size(setup->loop, UINT64_MAX, new_partition_size); if (r == -ENOTTY) log_debug_errno(r, "Device is not a loopback device, not refreshing size."); else if (r < 0) return log_error_errno(r, "Failed to refresh loopback device size: %m"); else log_info("Refreshing loop device size completed."); if (S_ISREG(st.st_mode)) { /* Shrink the image file */ if (ftruncate(image_fd, new_image_size) < 0) return log_error_errno(errno, "Failed to shrink image file %s: %m", ip); log_info("Shrinking of image file completed."); } else { assert(S_ISBLK(st.st_mode)); assert(new_image_size == old_image_size); } r = apply_resize_partition(image_fd, disk_uuid, table, partition, new_partition_size); if (r < 0) return r; if (r > 0) log_info("Shrinking of partition completed."); if (S_ISBLK(st.st_mode) && ioctl(image_fd, BLKRRPART, 0) < 0) log_debug_errno(errno, "BLKRRPART failed on block device, ignoring: %m"); } else { /* → Grow */ if (!FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES)) { r = home_store_embedded_identity(new_home, setup->root_fd, embedded_home); if (r < 0) return r; r = home_reconcile_blob_dirs(new_home, setup->root_fd, reconciled); if (r < 0) return r; } } if (!FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES)) { r = home_store_header_identity_luks(new_home, setup, header_home); if (r < 0) return r; r = home_extend_embedded_identity(new_home, h, setup); if (r < 0) return r; } if (user_record_luks_discard(h)) (void) run_fitrim(setup->root_fd); r = home_sync_and_statfs(setup->root_fd, &sfs); if (r < 0) return r; if (!FLAGS_SET(flags, HOME_SETUP_RESIZE_DONT_UNDO)) { r = home_setup_done(setup); if (r < 0) return r; } log_info("Resizing completed."); print_size_summary(new_image_size, new_fs_size, &sfs); if (ret_home) *ret_home = TAKE_PTR(new_home); return 0; } int home_passwd_luks( UserRecord *h, HomeSetupFlags flags, HomeSetup *setup, const PasswordCache *cache, /* the passwords acquired via PKCS#11/FIDO2 security tokens */ char **effective_passwords /* new passwords */) { size_t volume_key_size, max_key_slots, n_effective; _cleanup_(erase_and_freep) void *volume_key = NULL; struct crypt_pbkdf_type good_pbkdf, minimal_pbkdf; const char *type; int r; assert(h); assert(user_record_storage(h) == USER_LUKS); assert(setup); r = dlopen_cryptsetup(); if (r < 0) return r; type = sym_crypt_get_type(setup->crypt_device); if (!type) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine crypto device type."); r = sym_crypt_keyslot_max(type); if (r <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine number of key slots."); max_key_slots = r; r = sym_crypt_get_volume_key_size(setup->crypt_device); if (r <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine volume key size."); volume_key_size = (size_t) r; volume_key = malloc(volume_key_size); if (!volume_key) return log_oom(); r = luks_get_volume_key(h, setup->crypt_device, cache, volume_key, &volume_key_size, NULL); if (r == -ENOKEY) return log_error_errno(SYNTHETIC_ERRNO(ENOKEY), "Failed to unlock LUKS superblock with supplied passwords."); if (r < 0) return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); n_effective = strv_length(effective_passwords); build_good_pbkdf(&good_pbkdf, h); build_minimal_pbkdf(&minimal_pbkdf, h); for (size_t i = 0; i < max_key_slots; i++) { r = sym_crypt_keyslot_destroy(setup->crypt_device, i); if (r < 0 && !IN_SET(r, -ENOENT, -EINVAL)) /* Returns EINVAL or ENOENT if there's no key in this slot already */ return log_error_errno(r, "Failed to destroy LUKS password: %m"); if (i >= n_effective) { if (r >= 0) log_info("Destroyed LUKS key slot %zu.", i); continue; } if (password_cache_contains(cache, effective_passwords[i])) { /* Is this a FIDO2 or PKCS#11 password? */ log_debug("Using minimal PBKDF for slot %zu", i); r = sym_crypt_set_pbkdf_type(setup->crypt_device, &minimal_pbkdf); } else { log_debug("Using good PBKDF for slot %zu", i); r = sym_crypt_set_pbkdf_type(setup->crypt_device, &good_pbkdf); } if (r < 0) return log_error_errno(r, "Failed to tweak PBKDF for slot %zu: %m", i); r = sym_crypt_keyslot_add_by_volume_key( setup->crypt_device, i, volume_key, volume_key_size, effective_passwords[i], strlen(effective_passwords[i])); if (r < 0) return log_error_errno(r, "Failed to set up LUKS password: %m"); log_info("Updated LUKS key slot %zu.", i); } return 1; } int home_lock_luks(UserRecord *h, HomeSetup *setup) { const char *p; int r; assert(h); assert(setup); assert(setup->root_fd < 0); assert(!setup->crypt_device); r = acquire_open_luks_device(h, setup, /* graceful= */ false); if (r < 0) return r; log_info("Discovered used LUKS device %s.", setup->dm_node); assert_se(p = user_record_home_directory(h)); r = syncfs_path(AT_FDCWD, p); if (r < 0) /* Snake oil, but let's better be safe than sorry */ return log_error_errno(r, "Failed to synchronize file system %s: %m", p); log_info("File system synchronized."); /* Note that we don't invoke FIFREEZE here, it appears libcryptsetup/device-mapper already does that on its own for us */ r = sym_crypt_suspend(setup->crypt_device, setup->dm_name); if (r < 0) return log_error_errno(r, "Failed to suspend cryptsetup device: %s: %m", setup->dm_node); log_info("LUKS device suspended."); return 0; } int home_unlock_luks(UserRecord *h, HomeSetup *setup, const PasswordCache *cache) { _cleanup_(keyring_unlinkp) key_serial_t key_serial = -1; _cleanup_(erase_and_freep) void *vk = NULL; size_t vks; int r; assert(h); assert(setup); assert(!setup->crypt_device); r = acquire_open_luks_device(h, setup, /* graceful= */ false); if (r < 0) return r; log_info("Discovered used LUKS device %s.", setup->dm_node); r = sym_crypt_get_volume_key_size(setup->crypt_device); if (r <= 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size."); vks = (size_t) r; vk = malloc(vks); if (!vk) return log_oom(); r = luks_get_volume_key(h, setup->crypt_device, cache, vk, &vks, &key_serial); if (r == -ENOKEY) return log_error_errno(r, "No valid password for LUKS superblock."); if (r < 0) return log_error_errno(r, "Failed to unlock LUKS superblock: %m"); r = sym_crypt_resume_by_volume_key(setup->crypt_device, setup->dm_name, vk, vks); if (r < 0) return log_error_errno(r, "Failed to resume LUKS superblock: %m"); TAKE_KEY_SERIAL(key_serial); /* Leave key in kernel keyring */ log_info("LUKS device resumed."); return 0; } static int device_is_gone(HomeSetup *setup) { _cleanup_(sd_device_unrefp) sd_device *d = NULL; struct stat st; int r; assert(setup); if (!setup->dm_node) return true; if (stat(setup->dm_node, &st) < 0) { if (errno != ENOENT) return log_error_errno(errno, "Failed to stat block device node %s: %m", setup->dm_node); return true; } r = sd_device_new_from_stat_rdev(&d, &st); if (r < 0) { if (r != -ENODEV) return log_error_errno(errno, "Failed to allocate device object from block device node %s: %m", setup->dm_node); return true; } return false; } static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) { HomeSetup *setup = ASSERT_PTR(userdata); int r; if (!device_for_action(device, SD_DEVICE_REMOVE)) return 0; /* We don't really care for the device object passed to us, we just check if the device node still * exists */ r = device_is_gone(setup); if (r < 0) return r; if (r > 0) /* Yay! we are done! */ (void) sd_event_exit(sd_device_monitor_get_event(monitor), 0); return 0; } int wait_for_block_device_gone(HomeSetup *setup, usec_t timeout_usec) { _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *m = NULL; _cleanup_(sd_event_unrefp) sd_event *event = NULL; int r; assert(setup); /* So here's the thing: we enable "deferred deactivation" on our dm-crypt volumes. This means they * are automatically torn down once not used anymore (i.e. once unmounted). Which is great. It also * means that when we deactivate a home directory and try to tear down the volume that backs it, it * possibly is already torn down or in the process of being torn down, since we race against the * automatic tearing down. Which is fine, we handle errors from that. However, we lose the ability to * naturally wait for the tear down operation to complete: if we are not the ones who tear down the * device we are also not the ones who naturally block on that operation. Hence let's add some code * to actively wait for the device to go away, via sd-device. We'll call this whenever tearing down a * LUKS device, to ensure the device is really really gone before we proceed. Net effect: "homectl * deactivate foo && homectl activate foo" will work reliably, i.e. deactivation immediately followed * by activation will work. Also, by the time deactivation completes we can guarantee that all data * is sync'ed down to the lowest block layer as all higher levels are fully and entirely * destructed. */ if (!setup->dm_name) return 0; assert(setup->dm_node); log_debug("Waiting until %s disappears.", setup->dm_node); r = sd_event_new(&event); if (r < 0) return log_error_errno(r, "Failed to allocate event loop: %m"); r = sd_device_monitor_new(&m); if (r < 0) return log_error_errno(r, "Failed to allocate device monitor: %m"); r = sd_device_monitor_filter_add_match_subsystem_devtype(m, "block", "disk"); if (r < 0) return log_error_errno(r, "Failed to configure device monitor match: %m"); r = sd_device_monitor_attach_event(m, event); if (r < 0) return log_error_errno(r, "Failed to attach device monitor to event loop: %m"); r = sd_device_monitor_start(m, device_monitor_handler, setup); if (r < 0) return log_error_errno(r, "Failed to start device monitor: %m"); r = device_is_gone(setup); if (r < 0) return r; if (r > 0) { log_debug("%s has already disappeared before entering wait loop.", setup->dm_node); return 0; /* gone already */ } if (timeout_usec != USEC_INFINITY) { r = sd_event_add_time_relative(event, NULL, CLOCK_MONOTONIC, timeout_usec, 0, NULL, NULL); if (r < 0) return log_error_errno(r, "Failed to add timer event: %m"); } r = sd_event_loop(event); if (r < 0) return log_error_errno(r, "Failed to run event loop: %m"); r = device_is_gone(setup); if (r < 0) return r; if (r == 0) return log_error_errno(r, "Device %s still around.", setup->dm_node); log_debug("Successfully waited until device %s disappeared.", setup->dm_node); return 0; } int home_auto_shrink_luks(UserRecord *h, HomeSetup *setup, PasswordCache *cache) { struct statfs sfs; int r; assert(h); assert(user_record_storage(h) == USER_LUKS); assert(setup); assert(setup->root_fd >= 0); if (user_record_auto_resize_mode(h) != AUTO_RESIZE_SHRINK_AND_GROW) return 0; if (fstatfs(setup->root_fd, &sfs) < 0) return log_error_errno(errno, "Failed to statfs home directory: %m"); if (!fs_can_online_shrink_and_grow(sfs.f_type)) { log_debug("Not auto-shrinking file system, since selected file system cannot do both online shrink and grow."); return 0; } r = home_resize_luks( h, HOME_SETUP_ALREADY_ACTIVATED| HOME_SETUP_RESIZE_DONT_SYNC_IDENTITIES| HOME_SETUP_RESIZE_MINIMIZE| HOME_SETUP_RESIZE_DONT_GROW| HOME_SETUP_RESIZE_DONT_UNDO, setup, cache, NULL); if (r < 0) return r; return 1; }