diff options
Diffstat (limited to 'src/home/homework-luks.c')
| -rw-r--r-- | src/home/homework-luks.c | 3925 |
1 files changed, 3925 insertions, 0 deletions
diff --git a/src/home/homework-luks.c b/src/home/homework-luks.c new file mode 100644 index 0000000..5bd78a0 --- /dev/null +++ b/src/home/homework-luks.c @@ -0,0 +1,3925 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <linux/loop.h> +#include <poll.h> +#include <sys/file.h> +#include <sys/ioctl.h> +#include <sys/xattr.h> + +#if HAVE_VALGRIND_MEMCHECK_H +#include <valgrind/memcheck.h> +#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-luks.h" +#include "homework-mount.h" +#include "io-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; + _cleanup_free_ char *s = 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; + + s = strdup(fstype); + if (!s) + return -ENOMEM; + + *ret_fstype = TAKE_PTR(s); + *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 RET_NERRNO(ioctl(fd, BLKGETSIZE64, 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 char *password, + key_serial_t *ret_key_serial) { + + _cleanup_free_ char *name = NULL; + key_serial_t serial; + + assert(h); + assert(password); + + /* If auto-shrink-on-logout is turned on, we need to keep the key we used to unlock the LUKS volume + * around, since we'll need it when automatically resizing (since we can't ask the user there + * again). We do this by uploading it into the kernel keyring, specifically the "session" one. This + * is done under the assumption systemd-homed gets its private per-session keyring (i.e. default + * service behaviour, given that KeyringMode=private is the default). It will survive between our + * systemd-homework invocations that way. + * + * If auto-shrink-on-logout is disabled we'll skip this step, to be frugal with sensitive data. */ + + if (user_record_auto_resize_mode(h) != AUTO_RESIZE_SHRINK_AND_GROW) { /* Won't need it */ + if (ret_key_serial) + *ret_key_serial = -1; + return 0; + } + + name = strjoin("homework-user-", h->user_name); + if (!name) + return -ENOMEM; + + serial = add_key("user", name, password, strlen(password), KEY_SPEC_SESSION_KEYRING); + if (serial == -1) + return -errno; + + if (ret_key_serial) + *ret_key_serial = serial; + + return 1; +} + +static int luks_try_passwords( + UserRecord *h, + struct crypt_device *cd, + char **passwords, + void *volume_key, + size_t *volume_key_size, + key_serial_t *ret_key_serial) { + + int r; + + assert(h); + assert(cd); + + 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) { + if (ret_key_serial) { + /* If ret_key_serial is non-NULL, let's try to upload the password that + * worked, and return its serial. */ + r = upload_to_keyring(h, *pp, ret_key_serial); + if (r < 0) { + log_debug_errno(r, "Failed to upload LUKS password to kernel keyring, ignoring: %m"); + *ret_key_serial = -1; + } + } + + *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_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, + char **passwords, + 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; + char **list; + 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 = -ENOKEY; + FOREACH_POINTER(list, + cache ? cache->keyring_passswords : NULL, + cache ? cache->pkcs11_passwords : NULL, + cache ? cache->fido2_passwords : NULL, + passwords) { + r = luks_try_passwords(h, cd, list, vk, &vks, ret_key_serial ? &key_serial : NULL); + if (r != -ENOKEY) + break; + } + 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; + char **list; + 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 = -ENOKEY; + FOREACH_POINTER(list, + cache ? cache->keyring_passswords : NULL, + cache ? cache->pkcs11_passwords : NULL, + cache ? cache->fido2_passwords : NULL, + h->password) { + r = luks_try_passwords(h, setup->crypt_device, list, vk, &vks, NULL); + if (r != -ENOKEY) + break; + } + 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_(json_variant_unrefp) JsonVariant *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; + JsonVariant *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 = json_parse(text, 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 = json_variant_by_key(v, "record"); + if (!jr) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'record' field."); + jiv = json_variant_by_key(v, "iv"); + if (!jiv) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "LUKS token lacks 'iv' field."); + + r = json_variant_unbase64(jr, &encrypted, &encrypted_size); + if (r < 0) + return log_error_errno(r, "Failed to base64 decode record: %m"); + + r = 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 = json_parse(decrypted, 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_(json_variant_unrefp) JsonVariant *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 = 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 = json_build(&v, + JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("type", JSON_BUILD_CONST_STRING("systemd-homed")), + JSON_BUILD_PAIR("keyslots", JSON_BUILD_EMPTY_ARRAY), + JSON_BUILD_PAIR("record", JSON_BUILD_BASE64(encrypted, encrypted_size_out1 + encrypted_size_out2)), + JSON_BUILD_PAIR("iv", JSON_BUILD_BASE64(iv, iv_size)))); + if (r < 0) + return log_error_errno(r, "Failed to prepare LUKS JSON token object: %m"); + + r = 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 (ioctl(setup->loop->fd, BLKGETSIZE64, &size) < 0) + return log_error_errno(r, "Failed to read block device size 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; + } + } 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, + h->password, + 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 */ + *buffer = (struct crypt_pbkdf_type) { + .hash = user_record_luks_pbkdf_hash_algorithm(hr), + .type = CRYPT_KDF_PBKDF2, + .iterations = 1, + .time_ms = 1, + }; + + 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; + + if (laccess(path, F_OK) < 0) { + if (errno != ENOENT) + return log_error_errno(errno, "Failed to determine whether %s exists: %m", path); + } else + return 0; /* Found it */ + + 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); + + if (ioctl(setup->image_fd, BLKGETSIZE64, &block_device_size) < 0) + return log_error_errno(errno, "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, + 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_SB_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: %m"); + + 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; + 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); + + if (ioctl(image_fd, BLKGETSIZE64, &old_image_size) < 0) + return log_error_errno(errno, "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)) { + r = home_load_embedded_identity(h, setup->root_fd, header_home, USER_RECONCILE_REQUIRE_NEWER_OR_EQUAL, cache, &embedded_home, &new_home); + if (r < 0) + return r; + } + + 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, h->uid, embedded_home); + 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, h->uid, embedded_home); + 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; + char **list; + 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 = -ENOKEY; + FOREACH_POINTER(list, + cache ? cache->keyring_passswords : NULL, + cache ? cache->pkcs11_passwords : NULL, + cache ? cache->fido2_passwords : NULL, + h->password) { + + r = luks_try_passwords(h, setup->crypt_device, list, volume_key, &volume_key_size, NULL); + if (r != -ENOKEY) + break; + } + 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); + + /* If we changed the password, then make sure to update the copy in the keyring, so that + * auto-rebalance continues to work. We only do this if we operate on an active home dir. */ + if (i == 0 && FLAGS_SET(flags, HOME_SETUP_ALREADY_ACTIVATED)) + upload_to_keyring(h, effective_passwords[i], NULL); + } + + 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; +} + +static int luks_try_resume( + struct crypt_device *cd, + const char *dm_name, + char **password) { + + int r; + + assert(cd); + assert(dm_name); + + STRV_FOREACH(pp, password) { + r = sym_crypt_resume_by_passphrase( + cd, + dm_name, + CRYPT_ANY_SLOT, + *pp, + strlen(*pp)); + if (r >= 0) { + log_info("Resumed LUKS device %s.", dm_name); + return 0; + } + + log_debug_errno(r, "Password %zu didn't work for resuming device: %m", (size_t) (pp - password)); + } + + return -ENOKEY; +} + +int home_unlock_luks(UserRecord *h, HomeSetup *setup, const PasswordCache *cache) { + char **list; + 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 = -ENOKEY; + FOREACH_POINTER(list, + cache ? cache->pkcs11_passwords : NULL, + cache ? cache->fido2_passwords : NULL, + h->password) { + r = luks_try_resume(setup->crypt_device, setup->dm_name, list); + if (r != -ENOKEY) + break; + } + if (r == -ENOKEY) + return log_error_errno(r, "No valid password for LUKS superblock."); + if (r < 0) + return log_error_errno(r, "Failed to resume LUKS superblock: %m"); + + 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; +} |