/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include #include #include #include "btrfs-util.h" #include "bus-common-errors.h" #include "bus-error.h" #include "bus-log-control-api.h" #include "bus-polkit.h" #include "clean-ipc.h" #include "conf-files.h" #include "device-util.h" #include "dirent-util.h" #include "fd-util.h" #include "fileio.h" #include "format-util.h" #include "fs-util.h" #include "gpt.h" #include "home-util.h" #include "homed-conf.h" #include "homed-home-bus.h" #include "homed-home.h" #include "homed-manager-bus.h" #include "homed-manager.h" #include "homed-varlink.h" #include "io-util.h" #include "mkdir.h" #include "process-util.h" #include "quota-util.h" #include "random-util.h" #include "resize-fs.h" #include "socket-util.h" #include "sort-util.h" #include "stat-util.h" #include "strv.h" #include "sync-util.h" #include "tmpfile-util.h" #include "udev-util.h" #include "user-record-sign.h" #include "user-record-util.h" #include "user-record.h" #include "user-util.h" /* Where to look for private/public keys that are used to sign the user records. We are not using * CONF_PATHS_NULSTR() here since we want to insert /var/lib/systemd/home/ in the middle. And we insert that * since we want to auto-generate a persistent private/public key pair if we need to. */ #define KEY_PATHS_NULSTR \ "/etc/systemd/home/\0" \ "/run/systemd/home/\0" \ "/var/lib/systemd/home/\0" \ "/usr/local/lib/systemd/home/\0" \ "/usr/lib/systemd/home/\0" static bool uid_is_home(uid_t uid) { return uid >= HOME_UID_MIN && uid <= HOME_UID_MAX; } /* Takes a value generated randomly or by hashing and turns it into a UID in the right range */ #define UID_CLAMP_INTO_HOME_RANGE(rnd) (((uid_t) (rnd) % (HOME_UID_MAX - HOME_UID_MIN + 1)) + HOME_UID_MIN) DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(homes_by_uid_hash_ops, void, trivial_hash_func, trivial_compare_func, Home, home_free); DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(homes_by_name_hash_ops, char, string_hash_func, string_compare_func, Home, home_free); DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(homes_by_worker_pid_hash_ops, void, trivial_hash_func, trivial_compare_func, Home, home_free); DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(homes_by_sysfs_hash_ops, char, path_hash_func, path_compare, Home, home_free); static int on_home_inotify(sd_event_source *s, const struct inotify_event *event, void *userdata); static int manager_gc_images(Manager *m); static int manager_enumerate_images(Manager *m); static int manager_assess_image(Manager *m, int dir_fd, const char *dir_path, const char *dentry_name); static void manager_revalidate_image(Manager *m, Home *h); static void manager_watch_home(Manager *m) { struct statfs sfs; int r; assert(m); m->inotify_event_source = sd_event_source_disable_unref(m->inotify_event_source); m->scan_slash_home = false; if (statfs(get_home_root(), &sfs) < 0) { log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to statfs() %s directory, disabling automatic scanning.", get_home_root()); return; } if (is_network_fs(&sfs)) { log_info("%s is a network file system, disabling automatic scanning.", get_home_root()); return; } if (is_fs_type(&sfs, AUTOFS_SUPER_MAGIC)) { log_info("%s is on autofs, disabling automatic scanning.", get_home_root()); return; } m->scan_slash_home = true; r = sd_event_add_inotify(m->event, &m->inotify_event_source, get_home_root(), IN_CREATE|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF|IN_ONLYDIR|IN_MOVED_TO|IN_MOVED_FROM|IN_DELETE, on_home_inotify, m); if (r < 0) log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r, "Failed to create inotify watch on %s, ignoring.", get_home_root()); (void) sd_event_source_set_description(m->inotify_event_source, "home-inotify"); log_info("Watching %s.", get_home_root()); } static int on_home_inotify(sd_event_source *s, const struct inotify_event *event, void *userdata) { _cleanup_free_ char *j = NULL; Manager *m = userdata; const char *e, *n; assert(m); assert(event); if ((event->mask & (IN_Q_OVERFLOW|IN_MOVE_SELF|IN_DELETE_SELF|IN_IGNORED|IN_UNMOUNT)) != 0) { if (FLAGS_SET(event->mask, IN_Q_OVERFLOW)) log_debug("%s inotify queue overflow, rescanning.", get_home_root()); else if (FLAGS_SET(event->mask, IN_MOVE_SELF)) log_info("%s moved or renamed, recreating watch and rescanning.", get_home_root()); else if (FLAGS_SET(event->mask, IN_DELETE_SELF)) log_info("%s deleted, recreating watch and rescanning.", get_home_root()); else if (FLAGS_SET(event->mask, IN_UNMOUNT)) log_info("%s unmounted, recreating watch and rescanning.", get_home_root()); else if (FLAGS_SET(event->mask, IN_IGNORED)) log_info("%s watch invalidated, recreating watch and rescanning.", get_home_root()); manager_watch_home(m); (void) manager_gc_images(m); (void) manager_enumerate_images(m); (void) bus_manager_emit_auto_login_changed(m); return 0; } /* For the other inotify events, let's ignore all events for file names that don't match our * expectations */ if (isempty(event->name)) return 0; e = endswith(event->name, FLAGS_SET(event->mask, IN_ISDIR) ? ".homedir" : ".home"); if (!e) return 0; n = strndupa_safe(event->name, e - event->name); if (!suitable_user_name(n)) return 0; j = path_join(get_home_root(), event->name); if (!j) return log_oom(); if ((event->mask & (IN_CREATE|IN_CLOSE_WRITE|IN_MOVED_TO)) != 0) { if (FLAGS_SET(event->mask, IN_CREATE)) log_debug("%s has been created, having a look.", j); else if (FLAGS_SET(event->mask, IN_CLOSE_WRITE)) log_debug("%s has been modified, having a look.", j); else if (FLAGS_SET(event->mask, IN_MOVED_TO)) log_debug("%s has been moved in, having a look.", j); (void) manager_assess_image(m, -1, get_home_root(), event->name); (void) bus_manager_emit_auto_login_changed(m); } if ((event->mask & (IN_DELETE | IN_CLOSE_WRITE | IN_MOVED_FROM)) != 0) { Home *h; if (FLAGS_SET(event->mask, IN_DELETE)) log_debug("%s has been deleted, revalidating.", j); else if (FLAGS_SET(event->mask, IN_CLOSE_WRITE)) log_debug("%s has been closed after writing, revalidating.", j); else if (FLAGS_SET(event->mask, IN_MOVED_FROM)) log_debug("%s has been moved away, revalidating.", j); h = hashmap_get(m->homes_by_name, n); if (h) { manager_revalidate_image(m, h); (void) bus_manager_emit_auto_login_changed(m); } } return 0; } int manager_new(Manager **ret) { _cleanup_(manager_freep) Manager *m = NULL; int r; assert(ret); m = new(Manager, 1); if (!m) return -ENOMEM; *m = (Manager) { .default_storage = _USER_STORAGE_INVALID, .rebalance_interval_usec = 2 * USEC_PER_MINUTE, /* initially, rebalance every 2min */ }; r = manager_parse_config_file(m); if (r < 0) return r; r = sd_event_default(&m->event); if (r < 0) return r; r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); if (r < 0) return r; r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); if (r < 0) return r; (void) sd_event_set_watchdog(m->event, true); m->homes_by_uid = hashmap_new(&homes_by_uid_hash_ops); if (!m->homes_by_uid) return -ENOMEM; m->homes_by_name = hashmap_new(&homes_by_name_hash_ops); if (!m->homes_by_name) return -ENOMEM; m->homes_by_worker_pid = hashmap_new(&homes_by_worker_pid_hash_ops); if (!m->homes_by_worker_pid) return -ENOMEM; m->homes_by_sysfs = hashmap_new(&homes_by_sysfs_hash_ops); if (!m->homes_by_sysfs) return -ENOMEM; *ret = TAKE_PTR(m); return 0; } Manager* manager_free(Manager *m) { Home *h; assert(m); HASHMAP_FOREACH(h, m->homes_by_worker_pid) (void) home_wait_for_worker(h); m->bus = sd_bus_flush_close_unref(m->bus); m->polkit_registry = bus_verify_polkit_async_registry_free(m->polkit_registry); m->device_monitor = sd_device_monitor_unref(m->device_monitor); m->inotify_event_source = sd_event_source_unref(m->inotify_event_source); m->notify_socket_event_source = sd_event_source_unref(m->notify_socket_event_source); m->deferred_rescan_event_source = sd_event_source_unref(m->deferred_rescan_event_source); m->deferred_gc_event_source = sd_event_source_unref(m->deferred_gc_event_source); m->deferred_auto_login_event_source = sd_event_source_unref(m->deferred_auto_login_event_source); m->rebalance_event_source = sd_event_source_unref(m->rebalance_event_source); m->event = sd_event_unref(m->event); m->homes_by_uid = hashmap_free(m->homes_by_uid); m->homes_by_name = hashmap_free(m->homes_by_name); m->homes_by_worker_pid = hashmap_free(m->homes_by_worker_pid); m->homes_by_sysfs = hashmap_free(m->homes_by_sysfs); if (m->private_key) EVP_PKEY_free(m->private_key); hashmap_free(m->public_keys); varlink_server_unref(m->varlink_server); free(m->userdb_service); free(m->default_file_system_type); return mfree(m); } int manager_verify_user_record(Manager *m, UserRecord *hr) { EVP_PKEY *pkey; int r; assert(m); assert(hr); if (!m->private_key && hashmap_isempty(m->public_keys)) { r = user_record_has_signature(hr); if (r < 0) return r; return r ? -ENOKEY : USER_RECORD_UNSIGNED; } /* Is it our own? */ if (m->private_key) { r = user_record_verify(hr, m->private_key); switch (r) { case USER_RECORD_FOREIGN: /* This record is not signed by this key, but let's see below */ break; case USER_RECORD_SIGNED: /* Signed by us, but also by others, let's propagate that */ case USER_RECORD_SIGNED_EXCLUSIVE: /* Signed by us, and nothing else, ditto */ case USER_RECORD_UNSIGNED: /* Not signed at all, ditto */ default: return r; } } HASHMAP_FOREACH(pkey, m->public_keys) { r = user_record_verify(hr, pkey); switch (r) { case USER_RECORD_FOREIGN: /* This record is not signed by this key, but let's see our other keys */ break; case USER_RECORD_SIGNED: /* It's signed by this key we are happy with, but which is not our own. */ case USER_RECORD_SIGNED_EXCLUSIVE: return USER_RECORD_FOREIGN; case USER_RECORD_UNSIGNED: /* It's not signed at all */ default: return r; } } return -ENOKEY; } static int manager_add_home_by_record( Manager *m, const char *name, int dir_fd, const char *fname) { _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; _cleanup_(user_record_unrefp) UserRecord *hr = NULL; unsigned line, column; int r, is_signed; struct stat st; Home *h; assert(m); assert(name); assert(fname); if (fstatat(dir_fd, fname, &st, 0) < 0) return log_error_errno(errno, "Failed to stat identity record %s: %m", fname); if (!S_ISREG(st.st_mode)) { log_debug("Identity record file %s is not a regular file, ignoring.", fname); return 0; } if (st.st_size == 0) goto unlink_this_file; r = json_parse_file_at(NULL, dir_fd, fname, JSON_PARSE_SENSITIVE, &v, &line, &column); if (r < 0) return log_error_errno(r, "Failed to parse identity record at %s:%u%u: %m", fname, line, column); if (json_variant_is_blank_object(v)) goto unlink_this_file; hr = user_record_new(); if (!hr) return log_oom(); r = user_record_load(hr, v, USER_RECORD_LOAD_REFUSE_SECRET|USER_RECORD_LOG|USER_RECORD_PERMISSIVE); if (r < 0) return r; if (!streq_ptr(hr->user_name, name)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Identity's user name %s does not match file name %s, refusing.", hr->user_name, name); is_signed = manager_verify_user_record(m, hr); switch (is_signed) { case -ENOKEY: return log_warning_errno(is_signed, "User record %s is not signed by any accepted key, ignoring.", fname); case USER_RECORD_UNSIGNED: return log_warning_errno(SYNTHETIC_ERRNO(EPERM), "User record %s is not signed at all, ignoring.", fname); case USER_RECORD_SIGNED: log_info("User record %s is signed by us (and others), accepting.", fname); break; case USER_RECORD_SIGNED_EXCLUSIVE: log_info("User record %s is signed only by us, accepting.", fname); break; case USER_RECORD_FOREIGN: log_info("User record %s is signed by registered key from others, accepting.", fname); break; default: assert(is_signed < 0); return log_error_errno(is_signed, "Failed to verify signature of user record in %s: %m", fname); } h = hashmap_get(m->homes_by_name, name); if (h) { r = home_set_record(h, hr); if (r < 0) return log_error_errno(r, "Failed to update home record for %s: %m", name); /* If we acquired a record now for a previously unallocated entry, then reset the state. This * makes sure home_get_state() will check for the availability of the image file dynamically * in order to detect to distinguish HOME_INACTIVE and HOME_ABSENT. */ if (h->state == HOME_UNFIXATED) h->state = _HOME_STATE_INVALID; } else { r = home_new(m, hr, NULL, &h); if (r < 0) return log_error_errno(r, "Failed to allocate new home object: %m"); log_info("Added registered home for user %s.", hr->user_name); } /* Only entries we exclusively signed are writable to us, hence remember the result */ h->signed_locally = is_signed == USER_RECORD_SIGNED_EXCLUSIVE; return 1; unlink_this_file: /* If this is an empty file, then let's just remove it. An empty file is not useful in any case, and * apparently xfs likes to leave empty files around when not unmounted cleanly (see * https://github.com/systemd/systemd/issues/15178 for example). Note that we don't delete non-empty * files even if they are invalid, because that's just too risky, we might delete data the user still * needs. But empty files are never useful, hence let's just remove them. */ if (unlinkat(dir_fd, fname, 0) < 0) return log_error_errno(errno, "Failed to remove empty user record file %s: %m", fname); log_notice("Discovered empty user record file %s/%s, removed automatically.", home_record_dir(), fname); return 0; } static int manager_enumerate_records(Manager *m) { _cleanup_closedir_ DIR *d = NULL; assert(m); d = opendir(home_record_dir()); if (!d) return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to open %s: %m", home_record_dir()); FOREACH_DIRENT(de, d, return log_error_errno(errno, "Failed to read record directory: %m")) { _cleanup_free_ char *n = NULL; const char *e; if (!dirent_is_file(de)) continue; e = endswith(de->d_name, ".identity"); if (!e) continue; n = strndup(de->d_name, e - de->d_name); if (!n) return log_oom(); if (!suitable_user_name(n)) continue; (void) manager_add_home_by_record(m, n, dirfd(d), de->d_name); } return 0; } static int search_quota(uid_t uid, const char *exclude_quota_path) { struct stat exclude_st = {}; dev_t previous_devno = 0; int r; /* Checks whether the specified UID owns any files on the files system, but ignore any file system * backing the specified file. The file is used when operating on home directories, where it's OK if * the UID of them already owns files. */ if (exclude_quota_path && stat(exclude_quota_path, &exclude_st) < 0) { if (errno != ENOENT) return log_warning_errno(errno, "Failed to stat %s, ignoring: %m", exclude_quota_path); } /* Check a few usual suspects where regular users might own files. Note that this is by no means * comprehensive, but should cover most cases. Note that in an ideal world every user would be * registered in NSS and avoid our own UID range, but for all other cases, it's a good idea to be * paranoid and check quota if we can. */ FOREACH_STRING(where, get_home_root(), "/tmp/", "/var/", "/var/mail/", "/var/tmp/", "/var/spool/") { struct dqblk req; struct stat st; if (stat(where, &st) < 0) { log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to stat %s, ignoring: %m", where); continue; } if (major(st.st_dev) == 0) { log_debug("Directory %s is not on a real block device, not checking quota for UID use.", where); continue; } if (st.st_dev == exclude_st.st_dev) { /* If an exclude path is specified, then ignore quota * reported on the same block device as that path. */ log_debug("Directory %s is where the home directory is located, not checking quota for UID use.", where); continue; } if (st.st_dev == previous_devno) { /* Does this directory have the same devno as the previous * one we tested? If so, there's no point in testing this * again. */ log_debug("Directory %s is on same device as previous tested directory, not checking quota for UID use a second time.", where); continue; } previous_devno = st.st_dev; r = quotactl_devnum(QCMD_FIXED(Q_GETQUOTA, USRQUOTA), st.st_dev, uid, &req); if (r < 0) { if (ERRNO_IS_NOT_SUPPORTED(r)) log_debug_errno(r, "No UID quota support on %s, ignoring.", where); else if (ERRNO_IS_PRIVILEGE(r)) log_debug_errno(r, "UID quota support for %s prohibited, ignoring.", where); else log_warning_errno(r, "Failed to query quota on %s, ignoring: %m", where); continue; } if ((FLAGS_SET(req.dqb_valid, QIF_SPACE) && req.dqb_curspace > 0) || (FLAGS_SET(req.dqb_valid, QIF_INODES) && req.dqb_curinodes > 0)) { log_debug_errno(errno, "Quota reports UID " UID_FMT " occupies disk space on %s.", uid, where); return 1; } } return 0; } static int manager_acquire_uid( Manager *m, uid_t start_uid, const char *user_name, const char *exclude_quota_path, uid_t *ret) { static const uint8_t hash_key[] = { 0xa3, 0xb8, 0x82, 0x69, 0x9a, 0x71, 0xf7, 0xa9, 0xe0, 0x7c, 0xf6, 0xf1, 0x21, 0x69, 0xd2, 0x1e }; enum { PHASE_SUGGESTED, PHASE_HASHED, PHASE_RANDOM } phase = PHASE_SUGGESTED; unsigned n_tries = 100; int r; assert(m); assert(ret); for (;;) { struct passwd *pw; struct group *gr; uid_t candidate; Home *other; if (--n_tries <= 0) return -EBUSY; switch (phase) { case PHASE_SUGGESTED: phase = PHASE_HASHED; if (!uid_is_home(start_uid)) continue; candidate = start_uid; break; case PHASE_HASHED: phase = PHASE_RANDOM; if (!user_name) continue; candidate = UID_CLAMP_INTO_HOME_RANGE(siphash24(user_name, strlen(user_name), hash_key)); break; case PHASE_RANDOM: random_bytes(&candidate, sizeof(candidate)); candidate = UID_CLAMP_INTO_HOME_RANGE(candidate); break; default: assert_not_reached(); } other = hashmap_get(m->homes_by_uid, UID_TO_PTR(candidate)); if (other) { log_debug("Candidate UID " UID_FMT " already used by another home directory (%s), let's try another.", candidate, other->user_name); continue; } pw = getpwuid(candidate); if (pw) { log_debug("Candidate UID " UID_FMT " already registered by another user in NSS (%s), let's try another.", candidate, pw->pw_name); continue; } gr = getgrgid((gid_t) candidate); if (gr) { log_debug("Candidate UID " UID_FMT " already registered by another group in NSS (%s), let's try another.", candidate, gr->gr_name); continue; } r = search_ipc(candidate, (gid_t) candidate); if (r < 0) continue; if (r > 0) { log_debug_errno(r, "Candidate UID " UID_FMT " already owns IPC objects, let's try another: %m", candidate); continue; } r = search_quota(candidate, exclude_quota_path); if (r != 0) continue; *ret = candidate; return 0; } } static int manager_add_home_by_image( Manager *m, const char *user_name, const char *realm, const char *image_path, const char *sysfs, UserStorage storage, uid_t start_uid) { _cleanup_(user_record_unrefp) UserRecord *hr = NULL; uid_t uid; Home *h; int r; assert(m); assert(m); assert(user_name); assert(image_path); assert(storage >= 0); assert(storage < _USER_STORAGE_MAX); h = hashmap_get(m->homes_by_name, user_name); if (h) { bool same; if (h->state != HOME_UNFIXATED) { log_debug("Found an image for user %s which already has a record, skipping.", user_name); return 0; /* ignore images that synthesize a user we already have a record for */ } same = user_record_storage(h->record) == storage; if (same) { if (h->sysfs && sysfs) same = path_equal(h->sysfs, sysfs); else if (!!h->sysfs != !!sysfs) same = false; else { const char *p; p = user_record_image_path(h->record); same = p && path_equal(p, image_path); } } if (!same) { log_debug("Found multiple images for user '%s', ignoring image '%s'.", user_name, image_path); return 0; } } else { /* Check NSS, in case there's another user or group by this name */ if (getpwnam(user_name) || getgrnam(user_name)) { log_debug("Found an existing user or group by name '%s', ignoring image '%s'.", user_name, image_path); return 0; } } if (h && uid_is_valid(h->uid)) uid = h->uid; else { r = manager_acquire_uid(m, start_uid, user_name, IN_SET(storage, USER_SUBVOLUME, USER_DIRECTORY, USER_FSCRYPT) ? image_path : NULL, &uid); if (r < 0) return log_warning_errno(r, "Failed to acquire unused UID for %s: %m", user_name); } hr = user_record_new(); if (!hr) return log_oom(); r = user_record_synthesize(hr, user_name, realm, image_path, storage, uid, (gid_t) uid); if (r < 0) return log_error_errno(r, "Failed to synthesize home record for %s (image %s): %m", user_name, image_path); if (h) { r = home_set_record(h, hr); if (r < 0) return log_error_errno(r, "Failed to update home record for %s: %m", user_name); } else { r = home_new(m, hr, sysfs, &h); if (r < 0) return log_error_errno(r, "Failed to allocate new home object: %m"); h->state = HOME_UNFIXATED; log_info("Discovered new home for user %s through image %s.", user_name, image_path); } return 1; } int manager_augment_record_with_uid( Manager *m, UserRecord *hr) { const char *exclude_quota_path = NULL; uid_t start_uid = UID_INVALID, uid; int r; assert(m); assert(hr); if (uid_is_valid(hr->uid)) return 0; if (IN_SET(hr->storage, USER_CLASSIC, USER_SUBVOLUME, USER_DIRECTORY, USER_FSCRYPT)) { const char * ip; ip = user_record_image_path(hr); if (ip) { struct stat st; if (stat(ip, &st) < 0) { if (errno != ENOENT) log_warning_errno(errno, "Failed to stat(%s): %m", ip); } else if (uid_is_home(st.st_uid)) { start_uid = st.st_uid; exclude_quota_path = ip; } } } r = manager_acquire_uid(m, start_uid, hr->user_name, exclude_quota_path, &uid); if (r < 0) return r; log_debug("Acquired new UID " UID_FMT " for %s.", uid, hr->user_name); r = user_record_add_binding( hr, _USER_STORAGE_INVALID, NULL, SD_ID128_NULL, SD_ID128_NULL, SD_ID128_NULL, NULL, NULL, UINT64_MAX, NULL, NULL, uid, (gid_t) uid); if (r < 0) return r; return 1; } static int manager_assess_image( Manager *m, int dir_fd, const char *dir_path, const char *dentry_name) { char *luks_suffix, *directory_suffix; _cleanup_free_ char *path = NULL; struct stat st; int r; assert(m); assert(dir_path); assert(dentry_name); luks_suffix = endswith(dentry_name, ".home"); if (luks_suffix) directory_suffix = NULL; else directory_suffix = endswith(dentry_name, ".homedir"); /* Early filter out: by name */ if (!luks_suffix && !directory_suffix) return 0; path = path_join(dir_path, dentry_name); if (!path) return log_oom(); /* Follow symlinks here, to allow people to link in stuff to make them available locally. */ if (dir_fd >= 0) r = fstatat(dir_fd, dentry_name, &st, 0); else r = stat(path, &st); if (r < 0) return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to stat() directory entry '%s', ignoring: %m", dentry_name); if (S_ISREG(st.st_mode)) { _cleanup_free_ char *n = NULL, *user_name = NULL, *realm = NULL; if (!luks_suffix) return 0; n = strndup(dentry_name, luks_suffix - dentry_name); if (!n) return log_oom(); r = split_user_name_realm(n, &user_name, &realm); if (r == -EINVAL) /* Not the right format: ignore */ return 0; if (r < 0) return log_error_errno(r, "Failed to split image name into user name/realm: %m"); return manager_add_home_by_image(m, user_name, realm, path, NULL, USER_LUKS, UID_INVALID); } if (S_ISDIR(st.st_mode)) { _cleanup_free_ char *n = NULL, *user_name = NULL, *realm = NULL; _cleanup_close_ int fd = -1; UserStorage storage; if (!directory_suffix) return 0; n = strndup(dentry_name, directory_suffix - dentry_name); if (!n) return log_oom(); r = split_user_name_realm(n, &user_name, &realm); if (r == -EINVAL) /* Not the right format: ignore */ return 0; if (r < 0) return log_error_errno(r, "Failed to split image name into user name/realm: %m"); if (dir_fd >= 0) fd = openat(dir_fd, dentry_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC); else fd = open(path, O_DIRECTORY|O_RDONLY|O_CLOEXEC); if (fd < 0) return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, "Failed to open directory '%s', ignoring: %m", path); if (fstat(fd, &st) < 0) return log_warning_errno(errno, "Failed to fstat() %s, ignoring: %m", path); assert(S_ISDIR(st.st_mode)); /* Must hold, we used O_DIRECTORY above */ r = btrfs_is_subvol_fd(fd); if (r < 0) return log_warning_errno(errno, "Failed to determine whether %s is a btrfs subvolume: %m", path); if (r > 0) storage = USER_SUBVOLUME; else { struct fscrypt_policy policy; if (ioctl(fd, FS_IOC_GET_ENCRYPTION_POLICY, &policy) < 0) { if (errno == ENODATA) log_debug_errno(errno, "Determined %s is not fscrypt encrypted.", path); else if (ERRNO_IS_NOT_SUPPORTED(errno)) log_debug_errno(errno, "Determined %s is not fscrypt encrypted because kernel or file system doesn't support it.", path); else log_debug_errno(errno, "FS_IOC_GET_ENCRYPTION_POLICY failed with unexpected error code on %s, ignoring: %m", path); storage = USER_DIRECTORY; } else storage = USER_FSCRYPT; } return manager_add_home_by_image(m, user_name, realm, path, NULL, storage, st.st_uid); } return 0; } int manager_enumerate_images(Manager *m) { _cleanup_closedir_ DIR *d = NULL; assert(m); if (!m->scan_slash_home) return 0; d = opendir(get_home_root()); if (!d) return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to open %s: %m", get_home_root()); FOREACH_DIRENT(de, d, return log_error_errno(errno, "Failed to read %s directory: %m", get_home_root())) (void) manager_assess_image(m, dirfd(d), get_home_root(), de->d_name); return 0; } static int manager_connect_bus(Manager *m) { _cleanup_free_ char *b = NULL; const char *suffix, *busname; int r; assert(m); assert(!m->bus); r = sd_bus_default_system(&m->bus); if (r < 0) return log_error_errno(r, "Failed to connect to system bus: %m"); r = bus_add_implementation(m->bus, &manager_object, m); if (r < 0) return r; r = bus_log_control_api_register(m->bus); if (r < 0) return r; suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX"); if (suffix) { b = strjoin("org.freedesktop.home1.", suffix); if (!b) return log_oom(); busname = b; } else busname = "org.freedesktop.home1"; r = sd_bus_request_name_async(m->bus, NULL, busname, 0, NULL, NULL); if (r < 0) return log_error_errno(r, "Failed to request name: %m"); r = sd_bus_attach_event(m->bus, m->event, 0); if (r < 0) return log_error_errno(r, "Failed to attach bus to event loop: %m"); (void) sd_bus_set_exit_on_disconnect(m->bus, true); return 0; } static int manager_bind_varlink(Manager *m) { _cleanup_free_ char *p = NULL; const char *suffix, *socket_path; int r; assert(m); assert(!m->varlink_server); r = varlink_server_new(&m->varlink_server, VARLINK_SERVER_ACCOUNT_UID|VARLINK_SERVER_INHERIT_USERDATA); if (r < 0) return log_error_errno(r, "Failed to allocate varlink server object: %m"); varlink_server_set_userdata(m->varlink_server, m); r = varlink_server_bind_method_many( m->varlink_server, "io.systemd.UserDatabase.GetUserRecord", vl_method_get_user_record, "io.systemd.UserDatabase.GetGroupRecord", vl_method_get_group_record, "io.systemd.UserDatabase.GetMemberships", vl_method_get_memberships); if (r < 0) return log_error_errno(r, "Failed to register varlink methods: %m"); (void) mkdir_p("/run/systemd/userdb", 0755); /* To make things easier to debug, when working from a homed managed home directory, let's optionally * use a different varlink socket name */ suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX"); if (suffix) { p = strjoin("/run/systemd/userdb/io.systemd.Home.", suffix); if (!p) return log_oom(); socket_path = p; } else socket_path = "/run/systemd/userdb/io.systemd.Home"; r = varlink_server_listen_address(m->varlink_server, socket_path, 0666); if (r < 0) return log_error_errno(r, "Failed to bind to varlink socket: %m"); r = varlink_server_attach_event(m->varlink_server, m->event, SD_EVENT_PRIORITY_NORMAL); if (r < 0) return log_error_errno(r, "Failed to attach varlink connection to event loop: %m"); assert(!m->userdb_service); m->userdb_service = strdup(basename(socket_path)); if (!m->userdb_service) return log_oom(); /* Avoid recursion */ if (setenv("SYSTEMD_BYPASS_USERDB", m->userdb_service, 1) < 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to set $SYSTEMD_BYPASS_USERDB: %m"); return 0; } static ssize_t read_datagram( int fd, struct ucred *ret_sender, void **ret, int *ret_passed_fd) { CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) + CMSG_SPACE(sizeof(int))) control; _cleanup_free_ void *buffer = NULL; _cleanup_close_ int passed_fd = -1; struct ucred *sender = NULL; struct cmsghdr *cmsg; struct msghdr mh; struct iovec iov; ssize_t n, m; assert(fd >= 0); assert(ret_sender); assert(ret); assert(ret_passed_fd); n = next_datagram_size_fd(fd); if (n < 0) return n; buffer = malloc(n + 2); if (!buffer) return -ENOMEM; /* Pass one extra byte, as a size check */ iov = IOVEC_MAKE(buffer, n + 1); mh = (struct msghdr) { .msg_iov = &iov, .msg_iovlen = 1, .msg_control = &control, .msg_controllen = sizeof(control), }; m = recvmsg_safe(fd, &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC); if (m < 0) return m; /* Ensure the size matches what we determined before */ if (m != n) { cmsg_close_all(&mh); return -EMSGSIZE; } CMSG_FOREACH(cmsg, &mh) { if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_CREDENTIALS && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { assert(!sender); sender = (struct ucred*) CMSG_DATA(cmsg); } if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) { cmsg_close_all(&mh); return -EMSGSIZE; } assert(passed_fd < 0); passed_fd = *(int*) CMSG_DATA(cmsg); } } if (sender) *ret_sender = *sender; else *ret_sender = (struct ucred) UCRED_INVALID; *ret_passed_fd = TAKE_FD(passed_fd); /* For safety reasons: let's always NUL terminate. */ ((char*) buffer)[n] = 0; *ret = TAKE_PTR(buffer); return 0; } static int on_notify_socket(sd_event_source *s, int fd, uint32_t revents, void *userdata) { _cleanup_strv_free_ char **l = NULL; _cleanup_free_ void *datagram = NULL; _cleanup_close_ int passed_fd = -1; struct ucred sender = UCRED_INVALID; Manager *m = userdata; ssize_t n; Home *h; assert(s); assert(m); n = read_datagram(fd, &sender, &datagram, &passed_fd); if (n < 0) { if (ERRNO_IS_TRANSIENT(n)) return 0; return log_error_errno(n, "Failed to read notify datagram: %m"); } if (sender.pid <= 0) { log_warning("Received notify datagram without valid sender PID, ignoring."); return 0; } h = hashmap_get(m->homes_by_worker_pid, PID_TO_PTR(sender.pid)); if (!h) { log_warning("Received notify datagram of unknown process, ignoring."); return 0; } l = strv_split(datagram, "\n"); if (!l) return log_oom(); home_process_notify(h, l, TAKE_FD(passed_fd)); return 0; } static int manager_listen_notify(Manager *m) { _cleanup_close_ int fd = -1; union sockaddr_union sa = { .un.sun_family = AF_UNIX, .un.sun_path = "/run/systemd/home/notify", }; const char *suffix; int r; assert(m); assert(!m->notify_socket_event_source); suffix = getenv("SYSTEMD_HOME_DEBUG_SUFFIX"); if (suffix) { _cleanup_free_ char *unix_path = NULL; unix_path = strjoin("/run/systemd/home/notify.", suffix); if (!unix_path) return log_oom(); r = sockaddr_un_set_path(&sa.un, unix_path); if (r < 0) return log_error_errno(r, "Socket path %s does not fit in sockaddr_un: %m", unix_path); } fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (fd < 0) return log_error_errno(errno, "Failed to create listening socket: %m"); (void) mkdir_parents(sa.un.sun_path, 0755); (void) sockaddr_un_unlink(&sa.un); if (bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) return log_error_errno(errno, "Failed to bind to socket: %m"); r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true); if (r < 0) return r; r = sd_event_add_io(m->event, &m->notify_socket_event_source, fd, EPOLLIN, on_notify_socket, m); if (r < 0) return log_error_errno(r, "Failed to allocate event source for notify socket: %m"); (void) sd_event_source_set_description(m->notify_socket_event_source, "notify-socket"); /* Make sure we process sd_notify() before SIGCHLD for any worker, so that we always know the error * number of a client before it exits. */ r = sd_event_source_set_priority(m->notify_socket_event_source, SD_EVENT_PRIORITY_NORMAL - 5); if (r < 0) return log_error_errno(r, "Failed to alter priority of NOTIFY_SOCKET event source: %m"); r = sd_event_source_set_io_fd_own(m->notify_socket_event_source, true); if (r < 0) return log_error_errno(r, "Failed to pass ownership of notify socket: %m"); return TAKE_FD(fd); } static int manager_add_device(Manager *m, sd_device *d) { _cleanup_free_ char *user_name = NULL, *realm = NULL, *node = NULL; const char *tabletype, *parttype, *partname, *partuuid, *sysfs; sd_id128_t id; int r; assert(m); assert(d); r = sd_device_get_syspath(d, &sysfs); if (r < 0) return log_error_errno(r, "Failed to acquire sysfs path of device: %m"); r = sd_device_get_property_value(d, "ID_PART_TABLE_TYPE", &tabletype); if (r == -ENOENT) return 0; if (r < 0) return log_error_errno(r, "Failed to acquire ID_PART_TABLE_TYPE device property, ignoring: %m"); if (!streq(tabletype, "gpt")) { log_debug("Found partition (%s) on non-GPT table, ignoring.", sysfs); return 0; } r = sd_device_get_property_value(d, "ID_PART_ENTRY_TYPE", &parttype); if (r == -ENOENT) return 0; if (r < 0) return log_error_errno(r, "Failed to acquire ID_PART_ENTRY_TYPE device property, ignoring: %m"); if (id128_equal_string(parttype, GPT_USER_HOME) <= 0) { log_debug("Found partition (%s) we don't care about, ignoring.", sysfs); return 0; } r = sd_device_get_property_value(d, "ID_PART_ENTRY_NAME", &partname); if (r < 0) return log_warning_errno(r, "Failed to acquire ID_PART_ENTRY_NAME device property, ignoring: %m"); r = split_user_name_realm(partname, &user_name, &realm); if (r == -EINVAL) return log_warning_errno(r, "Found partition with correct partition type but a non-parsable partition name '%s', ignoring.", partname); if (r < 0) return log_error_errno(r, "Failed to validate partition name '%s': %m", partname); r = sd_device_get_property_value(d, "ID_FS_UUID", &partuuid); if (r < 0) return log_warning_errno(r, "Failed to acquire ID_FS_UUID device property, ignoring: %m"); r = sd_id128_from_string(partuuid, &id); if (r < 0) return log_warning_errno(r, "Failed to parse ID_FS_UUID field '%s', ignoring: %m", partuuid); if (asprintf(&node, "/dev/disk/by-uuid/" SD_ID128_UUID_FORMAT_STR, SD_ID128_FORMAT_VAL(id)) < 0) return log_oom(); return manager_add_home_by_image(m, user_name, realm, node, sysfs, USER_LUKS, UID_INVALID); } static int manager_on_device(sd_device_monitor *monitor, sd_device *d, void *userdata) { Manager *m = userdata; int r; assert(m); assert(d); if (device_for_action(d, SD_DEVICE_REMOVE)) { const char *sysfs; Home *h; r = sd_device_get_syspath(d, &sysfs); if (r < 0) { log_warning_errno(r, "Failed to acquire sysfs path from device: %m"); return 0; } log_info("block device %s has been removed.", sysfs); /* Let's see if we previously synthesized a home record from this device, if so, let's just * revalidate that. Otherwise let's revalidate them all, but asynchronously. */ h = hashmap_get(m->homes_by_sysfs, sysfs); if (h) manager_revalidate_image(m, h); else manager_enqueue_gc(m, NULL); } else (void) manager_add_device(m, d); (void) bus_manager_emit_auto_login_changed(m); return 0; } static int manager_watch_devices(Manager *m) { int r; assert(m); assert(!m->device_monitor); r = sd_device_monitor_new(&m->device_monitor); if (r < 0) return log_error_errno(r, "Failed to allocate device monitor: %m"); r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "block", NULL); if (r < 0) return log_error_errno(r, "Failed to configure device monitor match: %m"); r = sd_device_monitor_attach_event(m->device_monitor, 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, manager_on_device, m); if (r < 0) return log_error_errno(r, "Failed to start device monitor: %m"); return 0; } static int manager_enumerate_devices(Manager *m) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; sd_device *d; int r; assert(m); r = sd_device_enumerator_new(&e); if (r < 0) return r; r = sd_device_enumerator_add_match_subsystem(e, "block", true); if (r < 0) return r; FOREACH_DEVICE(e, d) (void) manager_add_device(m, d); return 0; } static int manager_load_key_pair(Manager *m) { _cleanup_(fclosep) FILE *f = NULL; struct stat st; int r; assert(m); if (m->private_key) { EVP_PKEY_free(m->private_key); m->private_key = NULL; } r = search_and_fopen_nulstr("local.private", "re", NULL, KEY_PATHS_NULSTR, &f, NULL); if (r == -ENOENT) return 0; if (r < 0) return log_error_errno(r, "Failed to read private key file: %m"); if (fstat(fileno(f), &st) < 0) return log_error_errno(errno, "Failed to stat private key file: %m"); r = stat_verify_regular(&st); if (r < 0) return log_error_errno(r, "Private key file is not regular: %m"); if (st.st_uid != 0 || (st.st_mode & 0077) != 0) return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Private key file is readable by more than the root user"); m->private_key = PEM_read_PrivateKey(f, NULL, NULL, NULL); if (!m->private_key) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to load private key pair"); log_info("Successfully loaded private key pair."); return 1; } DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(EVP_PKEY_CTX*, EVP_PKEY_CTX_free, NULL); static int manager_generate_key_pair(Manager *m) { _cleanup_(EVP_PKEY_CTX_freep) EVP_PKEY_CTX *ctx = NULL; _cleanup_(unlink_and_freep) char *temp_public = NULL, *temp_private = NULL; _cleanup_fclose_ FILE *fpublic = NULL, *fprivate = NULL; int r; if (m->private_key) { EVP_PKEY_free(m->private_key); m->private_key = NULL; } ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL); if (!ctx) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to allocate Ed25519 key generation context."); if (EVP_PKEY_keygen_init(ctx) <= 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to initialize Ed25519 key generation context."); log_info("Generating key pair for signing local user identity records."); if (EVP_PKEY_keygen(ctx, &m->private_key) <= 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to generate Ed25519 key pair"); log_info("Successfully created Ed25519 key pair."); (void) mkdir_p("/var/lib/systemd/home", 0755); /* Write out public key (note that we only do that as a help to the user, we don't make use of this ever */ r = fopen_temporary("/var/lib/systemd/home/local.public", &fpublic, &temp_public); if (r < 0) return log_error_errno(errno, "Failed to open key file for writing: %m"); if (PEM_write_PUBKEY(fpublic, m->private_key) <= 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to write public key."); r = fflush_sync_and_check(fpublic); if (r < 0) return log_error_errno(r, "Failed to write private key: %m"); fpublic = safe_fclose(fpublic); /* Write out the private key (this actually writes out both private and public, OpenSSL is confusing) */ r = fopen_temporary("/var/lib/systemd/home/local.private", &fprivate, &temp_private); if (r < 0) return log_error_errno(errno, "Failed to open key file for writing: %m"); if (PEM_write_PrivateKey(fprivate, m->private_key, NULL, NULL, 0, NULL, 0) <= 0) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to write private key pair."); r = fflush_sync_and_check(fprivate); if (r < 0) return log_error_errno(r, "Failed to write private key: %m"); fprivate = safe_fclose(fprivate); /* Both are written now, move them into place */ if (rename(temp_public, "/var/lib/systemd/home/local.public") < 0) return log_error_errno(errno, "Failed to move public key file into place: %m"); temp_public = mfree(temp_public); if (rename(temp_private, "/var/lib/systemd/home/local.private") < 0) { (void) unlink_noerrno("/var/lib/systemd/home/local.public"); /* try to remove the file we already created */ return log_error_errno(errno, "Failed to move private key file into place: %m"); } temp_private = mfree(temp_private); r = fsync_path_at(AT_FDCWD, "/var/lib/systemd/home/"); if (r < 0) log_warning_errno(r, "Failed to sync /var/lib/systemd/home/, ignoring: %m"); return 1; } int manager_acquire_key_pair(Manager *m) { int r; assert(m); /* Already there? */ if (m->private_key) return 1; /* First try to load key off disk */ r = manager_load_key_pair(m); if (r != 0) return r; /* Didn't work, generate a new one */ return manager_generate_key_pair(m); } int manager_sign_user_record(Manager *m, UserRecord *u, UserRecord **ret, sd_bus_error *error) { int r; assert(m); assert(u); assert(ret); r = manager_acquire_key_pair(m); if (r < 0) return r; if (r == 0) return sd_bus_error_set(error, BUS_ERROR_NO_PRIVATE_KEY, "Can't sign without local key."); return user_record_sign(u, m->private_key, ret); } DEFINE_PRIVATE_HASH_OPS_FULL(public_key_hash_ops, char, string_hash_func, string_compare_func, free, EVP_PKEY, EVP_PKEY_free); DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(EVP_PKEY*, EVP_PKEY_free, NULL); static int manager_load_public_key_one(Manager *m, const char *path) { _cleanup_(EVP_PKEY_freep) EVP_PKEY *pkey = NULL; _cleanup_fclose_ FILE *f = NULL; _cleanup_free_ char *fn = NULL; struct stat st; int r; assert(m); if (streq(basename(path), "local.public")) /* we already loaded the private key, which includes the public one */ return 0; f = fopen(path, "re"); if (!f) { if (errno == ENOENT) return 0; return log_error_errno(errno, "Failed to open public key %s: %m", path); } if (fstat(fileno(f), &st) < 0) return log_error_errno(errno, "Failed to stat public key %s: %m", path); r = stat_verify_regular(&st); if (r < 0) return log_error_errno(r, "Public key file %s is not a regular file: %m", path); if (st.st_uid != 0 || (st.st_mode & 0022) != 0) return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Public key file %s is writable by more than the root user, refusing.", path); r = hashmap_ensure_allocated(&m->public_keys, &public_key_hash_ops); if (r < 0) return log_oom(); pkey = PEM_read_PUBKEY(f, &pkey, NULL, NULL); if (!pkey) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to parse public key file %s.", path); fn = strdup(basename(path)); if (!fn) return log_oom(); r = hashmap_put(m->public_keys, fn, pkey); if (r < 0) return log_error_errno(r, "Failed to add public key to set: %m"); TAKE_PTR(fn); TAKE_PTR(pkey); return 0; } static int manager_load_public_keys(Manager *m) { _cleanup_strv_free_ char **files = NULL; int r; assert(m); m->public_keys = hashmap_free(m->public_keys); r = conf_files_list_nulstr( &files, ".public", NULL, CONF_FILES_REGULAR|CONF_FILES_FILTER_MASKED, KEY_PATHS_NULSTR); if (r < 0) return log_error_errno(r, "Failed to assemble list of public key directories: %m"); STRV_FOREACH(i, files) (void) manager_load_public_key_one(m, *i); return 0; } int manager_startup(Manager *m) { int r; assert(m); r = manager_listen_notify(m); if (r < 0) return r; r = manager_connect_bus(m); if (r < 0) return r; r = manager_bind_varlink(m); if (r < 0) return r; r = manager_load_key_pair(m); /* only try to load it, don't generate any */ if (r < 0) return r; r = manager_load_public_keys(m); if (r < 0) return r; manager_watch_home(m); (void) manager_watch_devices(m); (void) manager_enumerate_records(m); (void) manager_enumerate_images(m); (void) manager_enumerate_devices(m); /* Let's clean up home directories whose devices got removed while we were not running */ (void) manager_enqueue_gc(m, NULL); return 0; } void manager_revalidate_image(Manager *m, Home *h) { int r; assert(m); assert(h); /* Frees an automatically discovered image, if it's synthetic and its image disappeared. Unmounts any * image if it's mounted but it's image vanished. */ if (h->current_operation || !ordered_set_isempty(h->pending_operations)) return; if (h->state == HOME_UNFIXATED) { r = user_record_test_image_path(h->record); if (r < 0) log_warning_errno(r, "Can't determine if image of %s exists, freeing unfixated user: %m", h->user_name); else if (r == USER_TEST_ABSENT) log_info("Image for %s disappeared, freeing unfixated user.", h->user_name); else return; home_free(h); } else if (h->state < 0) { r = user_record_test_home_directory(h->record); if (r < 0) { log_warning_errno(r, "Unable to determine state of home directory, ignoring: %m"); return; } if (r == USER_TEST_MOUNTED) { r = user_record_test_image_path(h->record); if (r < 0) { log_warning_errno(r, "Unable to determine state of image path, ignoring: %m"); return; } if (r == USER_TEST_ABSENT) { _cleanup_(operation_unrefp) Operation *o = NULL; log_notice("Backing image disappeared while home directory %s was mounted, unmounting it forcibly.", h->user_name); /* Wowza, the thing is mounted, but the device is gone? Act on it. */ r = home_killall(h); if (r < 0) log_warning_errno(r, "Failed to kill processes of user %s, ignoring: %m", h->user_name); /* We enqueue the operation here, after all the home directory might * currently already run some operation, and we can deactivate it only after * that's complete. */ o = operation_new(OPERATION_DEACTIVATE_FORCE, NULL); if (!o) { log_oom(); return; } r = home_schedule_operation(h, o, NULL); if (r < 0) log_warning_errno(r, "Failed to enqueue forced home directory %s deactivation, ignoring: %m", h->user_name); } } } } int manager_gc_images(Manager *m) { Home *h; assert_se(m); if (m->gc_focus) { /* Focus on a specific home */ h = TAKE_PTR(m->gc_focus); manager_revalidate_image(m, h); } else { /* Gc all */ HASHMAP_FOREACH(h, m->homes_by_name) manager_revalidate_image(m, h); } return 0; } static int on_deferred_rescan(sd_event_source *s, void *userdata) { Manager *m = userdata; assert(m); m->deferred_rescan_event_source = sd_event_source_disable_unref(m->deferred_rescan_event_source); manager_enumerate_devices(m); manager_enumerate_images(m); return 0; } int manager_enqueue_rescan(Manager *m) { int r; assert(m); if (m->deferred_rescan_event_source) return 0; if (!m->event) return 0; if (IN_SET(sd_event_get_state(m->event), SD_EVENT_FINISHED, SD_EVENT_EXITING)) return 0; r = sd_event_add_defer(m->event, &m->deferred_rescan_event_source, on_deferred_rescan, m); if (r < 0) return log_error_errno(r, "Failed to allocate rescan event source: %m"); r = sd_event_source_set_priority(m->deferred_rescan_event_source, SD_EVENT_PRIORITY_IDLE+1); if (r < 0) log_warning_errno(r, "Failed to tweak priority of event source, ignoring: %m"); (void) sd_event_source_set_description(m->deferred_rescan_event_source, "deferred-rescan"); return 1; } static int on_deferred_gc(sd_event_source *s, void *userdata) { Manager *m = userdata; assert(m); m->deferred_gc_event_source = sd_event_source_disable_unref(m->deferred_gc_event_source); manager_gc_images(m); return 0; } int manager_enqueue_gc(Manager *m, Home *focus) { int r; assert(m); /* This enqueues a request to GC dead homes. It may be called with focus=NULL in which case all homes * will be scanned, or with the parameter set, in which case only that home is checked. */ if (!m->event) return 0; if (IN_SET(sd_event_get_state(m->event), SD_EVENT_FINISHED, SD_EVENT_EXITING)) return 0; /* If a focus home is specified, then remember to focus just on this home. Otherwise invalidate any * focus that might be set to look at all homes. */ if (m->deferred_gc_event_source) { if (m->gc_focus != focus) /* not the same focus, then look at everything */ m->gc_focus = NULL; return 0; } else m->gc_focus = focus; /* start focused */ r = sd_event_add_defer(m->event, &m->deferred_gc_event_source, on_deferred_gc, m); if (r < 0) return log_error_errno(r, "Failed to allocate GC event source: %m"); r = sd_event_source_set_priority(m->deferred_gc_event_source, SD_EVENT_PRIORITY_IDLE); if (r < 0) log_warning_errno(r, "Failed to tweak priority of event source, ignoring: %m"); (void) sd_event_source_set_description(m->deferred_gc_event_source, "deferred-gc"); return 1; } static bool manager_shall_rebalance(Manager *m) { Home *h; assert(m); if (IN_SET(m->rebalance_state, REBALANCE_PENDING, REBALANCE_SHRINKING, REBALANCE_GROWING)) return true; HASHMAP_FOREACH(h, m->homes_by_name) if (home_shall_rebalance(h)) return true; return false; } static int home_cmp(Home *const*a, Home *const*b) { int r; assert(a); assert(*a); assert(b); assert(*b); /* Order user records by their weight (and by their name, to make things stable). We put the records * with the highest weight last, since we distribute space from the beginning and round down, hence * later entries tend to get slightly more than earlier entries. */ r = CMP(user_record_rebalance_weight((*a)->record), user_record_rebalance_weight((*b)->record)); if (r != 0) return r; return strcmp((*a)->user_name, (*b)->user_name); } static int manager_rebalance_calculate(Manager *m) { uint64_t weight_sum, free_sum, usage_sum = 0, min_free = UINT64_MAX; _cleanup_free_ Home **array = NULL; bool relevant = false; struct statfs sfs; int c = 0, r; Home *h; assert(m); if (statfs(get_home_root(), &sfs) < 0) return log_error_errno(errno, "Failed to statfs() /home: %m"); free_sum = (uint64_t) sfs.f_bsize * sfs.f_bavail; /* This much free space is available on the * underlying pool directory */ weight_sum = REBALANCE_WEIGHT_BACKING; /* Grant the underlying pool directory a fixed weight of 20 * (home dirs get 100 by default, i.e. 5x more). This weight * is not configurable, the per-home weights are. */ HASHMAP_FOREACH(h, m->homes_by_name) { statfs_f_type_t fstype; h->rebalance_pending = false; /* First, reset the flag, we only want it to be true for the * homes that qualify for rebalancing */ if (!home_shall_rebalance(h)) /* Only look at actual candidates */ continue; if (home_is_busy(h)) return -EBUSY; /* Let's not rebalance if there's a busy home directory. */ r = home_get_disk_status( h, &h->rebalance_size, &h->rebalance_usage, &h->rebalance_free, NULL, NULL, &fstype, NULL); if (r < 0) { log_warning_errno(r, "Failed to get free space of home '%s', ignoring.", h->user_name); continue; } if (h->rebalance_free > UINT64_MAX - free_sum) return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "Rebalance free overflow"); free_sum += h->rebalance_free; if (h->rebalance_usage > UINT64_MAX - usage_sum) return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "Rebalance usage overflow"); usage_sum += h->rebalance_usage; h->rebalance_weight = user_record_rebalance_weight(h->record); if (h->rebalance_weight > UINT64_MAX - weight_sum) return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "Rebalance weight overflow"); weight_sum += h->rebalance_weight; h->rebalance_min = minimal_size_by_fs_magic(fstype); if (!GREEDY_REALLOC(array, c+1)) return log_oom(); array[c++] = h; } if (c == 0) { log_debug("No homes to rebalance."); return 0; } assert(weight_sum > 0); log_debug("Disk space usage by all home directories to rebalance: %s — available disk space: %s", FORMAT_BYTES(usage_sum), FORMAT_BYTES(free_sum)); /* Bring the home directories in a well-defined order, so that we distribute space in a reproducible * way for the same parameters. */ typesafe_qsort(array, c, home_cmp); for (int i = 0; i < c; i++) { uint64_t new_free; double d; h = array[i]; assert(h->rebalance_free <= free_sum); assert(h->rebalance_usage <= usage_sum); assert(h->rebalance_weight <= weight_sum); d = ((double) (free_sum / 4096) * (double) h->rebalance_weight) / (double) weight_sum; /* Calculate new space for this home in units of 4K */ /* Convert from units of 4K back to bytes */ if (d >= (double) (UINT64_MAX/4096)) new_free = UINT64_MAX; else new_free = (uint64_t) d * 4096; /* Subtract the weight and assigned space from the sums now, to distribute the rounding noise * to the remaining home dirs */ free_sum = LESS_BY(free_sum, new_free); weight_sum = LESS_BY(weight_sum, h->rebalance_weight); /* Keep track of home directory with the least amount of space left: we want to schedule the * next rebalance more quickly if this is low */ if (new_free < min_free) min_free = h->rebalance_size; if (new_free > UINT64_MAX - h->rebalance_usage) h->rebalance_goal = UINT64_MAX-1; /* maximum size */ else { h->rebalance_goal = h->rebalance_usage + new_free; if (h->rebalance_min != UINT64_MAX && h->rebalance_goal < h->rebalance_min) h->rebalance_goal = h->rebalance_min; } /* Skip over this home if the state doesn't match the operation */ if ((m->rebalance_state == REBALANCE_SHRINKING && h->rebalance_goal > h->rebalance_size) || (m->rebalance_state == REBALANCE_GROWING && h->rebalance_goal < h->rebalance_size)) h->rebalance_pending = false; else { log_debug("Rebalancing home directory '%s' %s → %s.", h->user_name, FORMAT_BYTES(h->rebalance_size), FORMAT_BYTES(h->rebalance_goal)); h->rebalance_pending = true; } if ((fabs((double) h->rebalance_size - (double) h->rebalance_goal) * 100 / (double) h->rebalance_size) >= 5.0) relevant = true; } /* Scale next rebalancing interval based on the least amount of space of any of the home * directories. We pick a time in the range 1min … 15min, scaled by log2(min_free), so that: * 10M → ~0.7min, 100M → ~2.7min, 1G → ~4.6min, 10G → ~6.5min, 100G ~8.4 */ m->rebalance_interval_usec = (usec_t) CLAMP((LESS_BY(log2(min_free), 22)*15*USEC_PER_MINUTE)/26, 1 * USEC_PER_MINUTE, 15 * USEC_PER_MINUTE); log_debug("Rebalancing interval set to %s.", FORMAT_TIMESPAN(m->rebalance_interval_usec, USEC_PER_MSEC)); /* Let's suppress small resizes, growing/shrinking file systems isn't free after all */ if (!relevant) { log_debug("Skipping rebalancing, since all calculated size changes are below ±5%%."); return 0; } return c; } static int manager_rebalance_apply(Manager *m) { int c = 0, r; Home *h; assert(m); HASHMAP_FOREACH(h, m->homes_by_name) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; if (!h->rebalance_pending) continue; h->rebalance_pending = false; r = home_resize(h, h->rebalance_goal, /* secret= */ NULL, /* automatic= */ true, &error); if (r < 0) log_warning_errno(r, "Failed to resize home '%s' for rebalancing, ignoring: %s", h->user_name, bus_error_message(&error, r)); else c++; } return c; } static void manager_rebalance_reply_messages(Manager *m) { int r; assert(m); for (;;) { _cleanup_(sd_bus_message_unrefp) sd_bus_message *msg = set_steal_first(m->rebalance_pending_method_calls); if (!msg) break; r = sd_bus_reply_method_return(msg, NULL); if (r < 0) log_debug_errno(r, "Failed to reply to rebalance method call, ignoring: %m"); } } static int manager_rebalance_now(Manager *m) { RebalanceState busy_state; /* the state to revert to when operation fails if busy */ int r; assert(m); log_debug("Rebalancing now..."); /* We maintain a simple state engine here to keep track of what we are doing. We'll first shrink all * homes that shall be shrunk and then grow all homes that shall be grown, so that they can take up * the space now freed. */ for (;;) { switch (m->rebalance_state) { case REBALANCE_IDLE: case REBALANCE_PENDING: case REBALANCE_WAITING: /* First shrink large home dirs */ m->rebalance_state = REBALANCE_SHRINKING; busy_state = REBALANCE_PENDING; /* We are initiating the next rebalancing cycle now, let's make the queued methods * calls the pending ones, and flush out any pending ones (which shouldn't exist at * this time anyway) */ set_clear(m->rebalance_pending_method_calls); SWAP_TWO(m->rebalance_pending_method_calls, m->rebalance_queued_method_calls); log_debug("Shrinking phase.."); break; case REBALANCE_SHRINKING: /* Then grow small home dirs */ m->rebalance_state = REBALANCE_GROWING; busy_state = REBALANCE_SHRINKING; log_debug("Growing phase.."); break; case REBALANCE_GROWING: /* Finally, we are done */ log_info("Rebalancing complete."); m->rebalance_state = REBALANCE_IDLE; r = 0; goto finish; case REBALANCE_OFF: default: assert_not_reached(); } r = manager_rebalance_calculate(m); if (r == -EBUSY) { /* Calculations failed because one home directory is currently busy. Revert to a state that * tells us what to do next. */ log_debug("Can't enter phase, busy."); m->rebalance_state = busy_state; return r; } if (r < 0) goto finish; if (r == 0) continue; /* got to next step immediately, if there's nothing to do */ r = manager_rebalance_apply(m); if (r < 0) goto finish; if (r > 0) break; /* At least one resize operation is now pending, we are done for now */ /* If there was nothing to apply, go for next state right-away */ } return 0; finish: /* Reset state and schedule next rebalance */ m->rebalance_state = REBALANCE_IDLE; manager_rebalance_reply_messages(m); (void) manager_schedule_rebalance(m, /* immediately= */ false); return r; } static int on_rebalance_timer(sd_event_source *s, usec_t t, void *userdata) { Manager *m = userdata; assert(s); assert(m); assert(IN_SET(m->rebalance_state, REBALANCE_WAITING, REBALANCE_PENDING, REBALANCE_SHRINKING, REBALANCE_GROWING)); (void) manager_rebalance_now(m); return 0; } int manager_schedule_rebalance(Manager *m, bool immediately) { int r; assert(m); /* Check if there are any records where rebalancing is requested */ if (!manager_shall_rebalance(m)) { log_debug("Not scheduling rebalancing, not needed."); r = 0; /* report that we didn't schedule anything because nothing needed it */ goto turn_off; } if (immediately) { /* If we are told to rebalance immediately, then mark a rebalance as pending (even if we area * already running one) */ if (m->rebalance_event_source) { r = sd_event_source_set_time(m->rebalance_event_source, 0); if (r < 0) { log_error_errno(r, "Failed to schedule immediate rebalancing: %m"); goto turn_off; } r = sd_event_source_set_enabled(m->rebalance_event_source, SD_EVENT_ONESHOT); if (r < 0) { log_error_errno(r, "Failed to enable rebalancing event source: %m"); goto turn_off; } } else { r = sd_event_add_time(m->event, &m->rebalance_event_source, CLOCK_MONOTONIC, 0, USEC_PER_SEC, on_rebalance_timer, m); if (r < 0) { log_error_errno(r, "Failed to allocate rebalance event source: %m"); goto turn_off; } r = sd_event_source_set_priority(m->rebalance_event_source, SD_EVENT_PRIORITY_IDLE + 10); if (r < 0) { log_error_errno(r, "Failed to set rebalance event source priority: %m"); goto turn_off; } (void) sd_event_source_set_description(m->rebalance_event_source, "rebalance"); } if (!IN_SET(m->rebalance_state, REBALANCE_PENDING, REBALANCE_SHRINKING, REBALANCE_GROWING)) m->rebalance_state = REBALANCE_PENDING; log_debug("Scheduled immediate rebalancing..."); return 1; /* report that we scheduled something */ } /* If we are told to schedule a rebalancing eventually, then do so only if we are not executing * anything yet. Also if we have something scheduled already, leave it in place */ if (!IN_SET(m->rebalance_state, REBALANCE_OFF, REBALANCE_IDLE)) return 1; /* report that there's already something scheduled */ if (m->rebalance_event_source) { r = sd_event_source_set_time_relative(m->rebalance_event_source, m->rebalance_interval_usec); if (r < 0) { log_error_errno(r, "Failed to schedule immediate rebalancing: %m"); goto turn_off; } r = sd_event_source_set_enabled(m->rebalance_event_source, SD_EVENT_ONESHOT); if (r < 0) { log_error_errno(r, "Failed to enable rebalancing event source: %m"); goto turn_off; } } else { r = sd_event_add_time_relative(m->event, &m->rebalance_event_source, CLOCK_MONOTONIC, m->rebalance_interval_usec, USEC_PER_SEC, on_rebalance_timer, m); if (r < 0) { log_error_errno(r, "Failed to allocate rebalance event source: %m"); goto turn_off; } r = sd_event_source_set_priority(m->rebalance_event_source, SD_EVENT_PRIORITY_IDLE + 10); if (r < 0) { log_error_errno(r, "Failed to set rebalance event source priority: %m"); goto turn_off; } (void) sd_event_source_set_description(m->rebalance_event_source, "rebalance"); } m->rebalance_state = REBALANCE_WAITING; /* We managed to enqueue a timer event, we now wait until it fires */ log_debug("Scheduled rebalancing in %s...", FORMAT_TIMESPAN(m->rebalance_interval_usec, 0)); return 1; /* report that we scheduled something */ turn_off: m->rebalance_event_source = sd_event_source_disable_unref(m->rebalance_event_source); m->rebalance_state = REBALANCE_OFF; manager_rebalance_reply_messages(m); return r; } int manager_reschedule_rebalance(Manager *m) { int r; assert(m); /* If a rebalance is pending reschedules it so it gets executed immediately */ if (!IN_SET(m->rebalance_state, REBALANCE_PENDING, REBALANCE_SHRINKING, REBALANCE_GROWING)) return 0; r = manager_schedule_rebalance(m, /* immediately= */ true); if (r < 0) return r; return 1; }