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systemd/src/home/homework-luks.c
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/* 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/mount.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 "blkid-util.h"
#include "blockdev-util.h"
#include "btrfs-util.h"
#include "chattr-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 "gpt.h"
#include "home-util.h"
#include "homework-luks.h"
#include "homework-mount.h"
#include "id128-util.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 != ENODATA)
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 = -1;
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 > 0 ? -errno : -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 (IN_SET(r, -2, 1)) /* nothing found or ambiguous result */
return -ENOPKG;
if (r != 0)
return errno > 0 ? -errno : -EIO;
(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 = -1;
fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
if (fd < 0)
return -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 = -1;
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(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|FORK_LOG|FORK_STDOUT_TO_STDERR|FORK_CLOSE_ALL_FDS,
&fsck_pid);
if (r < 0)
return r;
if (r == 0) {
/* Child */
execl("/sbin/fsck", "/sbin/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_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 unlocks 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;
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 > 0 ? -errno : -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 (IN_SET(r, -2, 1)) /* nothing found or ambiguous result */
return -ENOPKG;
if (r != 0)
return errno > 0 ? -errno : -EIO;
(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 > 0 ? -errno : -ENOMEM;
errno = 0;
n = blkid_partlist_numof_partitions(pl);
if (n < 0)
return errno > 0 ? -errno : -EIO;
for (int i = 0; i < n; i++) {
blkid_partition pp;
sd_id128_t id = SD_ID128_NULL;
const char *sid;
errno = 0;
pp = blkid_partlist_get_partition(pl, i);
if (!pp)
return errno > 0 ? -errno : -EIO;
if (id128_equal_string(blkid_partition_get_type_string(pp), GPT_USER_HOME) <= 0)
continue;
if (!streq_ptr(blkid_partition_get_name(pp), label))
continue;
sid = blkid_partition_get_uuid(pp);
if (sid) {
r = sd_id128_from_string(sid, &id);
if (r < 0)
log_debug_errno(r, "Couldn't parse partition UUID %s, weird: %m", sid);
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 = genuine_random_bytes(iv, iv_size, RANDOM_BLOCK);
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 = -1;
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 = -1;
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 = SD_ID128_NULL, found_luks_uuid = SD_ID128_NULL, found_fs_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(n, O_RDWR, &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, 0, &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;
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);
we_detached = false;
}
}
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_DEVICE_ABSENT(r) || r == -EINVAL) {
log_debug_errno(r, "LUKS device %s is already detached.", setup->dm_node);
we_detached = false;
} 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);
*buffer = (struct crypt_pbkdf_type) {
.hash = user_record_luks_pbkdf_hash_algorithm(hr),
.type = user_record_luks_pbkdf_type(hr),
.time_ms = user_record_luks_pbkdf_time_cost_usec(hr) / USEC_PER_MSEC,
.max_memory_kb = user_record_luks_pbkdf_memory_cost(hr) / 1024,
.parallel_threads = user_record_luks_pbkdf_parallel_threads(hr),
};
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 = genuine_random_bytes(volume_key, volume_key_size, RANDOM_BLOCK);
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 = 512U,
.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,
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 *path = NULL, *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, GPT_USER_HOME_STR);
if (r < 0)
return log_error_errno(r, "Failed to initialize partition type: %m");
c = fdisk_new_context();
if (!c)
return log_oom();
if (asprintf(&path, "/proc/self/fd/%i", fd) < 0)
return log_oom();
r = fdisk_assign_device(c, path, 0);
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 = -1;
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");
}
dn = dirname_malloc(path);
for (;;) {
if (!dn)
return log_oom();
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;
if (empty_or_root(dn))
break;
dn = dirname_malloc(dn);
}
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, usec_sub_unsigned(until, w));
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 = -1;
const char *fstype, *ip;
struct statfs sfs;
int r;
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. an 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(t, setup->image_fd, 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_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, 0, &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);
}
r = loop_device_flock(setup->loop, LOCK_EX); /* make sure udev won't read before we are done */
if (r < 0)
return log_error_errno(r, "Failed to take lock on loop device: %m");
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 = make_filesystem(setup->dm_node, fstype, user_record_user_name_and_realm(h), fs_uuid, user_record_luks_discard(h));
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(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|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|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 *path = NULL, *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;
return 0;
}
c = fdisk_new_context();
if (!c)
return log_oom();
if (asprintf(&path, "/proc/self/fd/%i", fd) < 0)
return log_oom();
r = fdisk_assign_device(c, path, 0);
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 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;
_cleanup_free_ char *path = NULL;
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");
two_zero_lbas = malloc0(1024U);
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, 1024U, 0);
if (n < 0)
return log_error_errno(errno, "Failed to wipe partition table: %m");
if (n != 1024)
return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write while wiping partition table.");
c = fdisk_new_context();
if (!c)
return log_oom();
if (asprintf(&path, "/proc/self/fd/%i", fd) < 0)
return log_oom();
r = fdisk_assign_device(c, path, 0);
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 give this involves shelling out
* multiple programs it's a bit too cumbersome to 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 = -1;
_cleanup_free_ char *whole_disk = NULL;
int r, resize_type, image_fd = -1;
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);
r = device_path_make_major_minor(st.st_mode, parent, &whole_disk);
if (r < 0)
return log_error_errno(r, "Failed to derive whole disk path for %s: %m", ip);
opened_image_fd = open(whole_disk, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
if (opened_image_fd < 0)
return log_error_errno(errno, "Failed to open whole block device %s: %m", whole_disk);
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);
if (!S_ISBLK(st.st_mode))
return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Whole block device %s is not actually a block device, refusing.", 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 asymetry 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.");
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;
new_partition_size_rounded = DISK_SIZE_ROUND_DOWN(h->disk_size);
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, partition size %s → %s, file system size %s → %s.",
FORMAT_BYTES(old_image_size),
FORMAT_BYTES(new_image_size),
FORMAT_BYTES(setup->partition_size),
FORMAT_BYTES(new_partition_size),
FORMAT_BYTES(old_fs_size),
FORMAT_BYTES(new_fs_size));
r = prepare_resize_partition(
image_fd,
setup->partition_offset,
setup->partition_size,
&disk_uuid,
&table,
&partition);
if (r < 0)
return r;
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 unlocks 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 = userdata;
int r;
assert(setup);
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;
}
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