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src/sysusers/sysusers.c
2 442 строки
91 KB
Frantisek Sumsal
sysusers: gracefully handle existing group in /etc/gshadow
04 авг 2026, 02:17
04 авг 2026, 02:17
36a9875
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/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include <stdlib.h> #include <sys/stat.h> #include "alloc-util.h" #include "build.h" #include "chase.h" #include "conf-files.h" #include "constants.h" #include "copy.h" #include "creds-util.h" #include "dissect-image.h" #include "dlopen-note.h" #include "errno-util.h" #include "extract-word.h" #include "fd-util.h" #include "fileio.h" #include "format-table.h" #include "format-util.h" #include "fs-util.h" #include "hashmap.h" #include "image-policy.h" #include "install-file.h" #include "label-util.h" #include "libaudit-util.h" #include "libcrypt-util.h" #include "log.h" #include "loop-util.h" #include "main-func.h" #include "mount-util.h" #include "options.h" #include "pager.h" #include "parse-argument.h" #include "path-util.h" #include "pretty-print.h" #include "set.h" #include "smack-util.h" #include "specifier.h" #include "string-util.h" #include "strv.h" #include "sync-util.h" #include "time-util.h" #include "tmpfile-util.h" #include "uid-classification.h" #include "uid-range.h" #include "user-util.h" #include "verbs.h" typedef enum ItemType { ADD_USER = 'u', ADD_GROUP = 'g', ADD_MEMBER = 'm', ADD_RANGE = 'r', } ItemType; static const char* item_type_to_string(ItemType t) { switch (t) { case ADD_USER: return "user"; case ADD_GROUP: return "group"; case ADD_MEMBER: return "member"; case ADD_RANGE: return "range"; default: assert_not_reached(); } } typedef struct Item { ItemType type; char *name; char *group_name; char *uid_path; char *gid_path; char *description; char *home; char *shell; gid_t gid; uid_t uid; char *filename; unsigned line; bool gid_set; /* When set the group with the specified GID must exist * and the check if a UID clashes with the GID is skipped. */ bool id_set_strict; bool uid_set; bool locked; bool todo_user; bool todo_group; } Item; static char *arg_root = NULL; static char *arg_image = NULL; static CatFlags arg_cat_flags = CAT_CONFIG_OFF; static const char *arg_replace = NULL; static bool arg_dry_run = false; static bool arg_inline = false; static PagerFlags arg_pager_flags = 0; static ImagePolicy *arg_image_policy = NULL; STATIC_DESTRUCTOR_REGISTER(arg_root, freep); STATIC_DESTRUCTOR_REGISTER(arg_image, freep); STATIC_DESTRUCTOR_REGISTER(arg_image_policy, image_policy_freep); typedef struct Context { int audit_fd; OrderedHashmap *users, *groups; OrderedHashmap *todo_uids, *todo_gids; OrderedHashmap *members; Hashmap *database_by_uid, *database_by_username; Hashmap *database_by_gid, *database_by_groupname; /* A helper set to hold names that are used by database_by_{uid,gid,username,groupname} above. */ Set *names; uid_t search_uid; UIDRange *uid_range; UGIDAllocationRange login_defs; bool login_defs_need_warning; LabelContext *label_context; } Context; static void context_done(Context *c) { assert(c); c->audit_fd = close_audit_fd(c->audit_fd); ordered_hashmap_free(c->groups); ordered_hashmap_free(c->users); ordered_hashmap_free(c->members); ordered_hashmap_free(c->todo_uids); ordered_hashmap_free(c->todo_gids); hashmap_free(c->database_by_uid); hashmap_free(c->database_by_username); hashmap_free(c->database_by_gid); hashmap_free(c->database_by_groupname); set_free(c->names); uid_range_free(c->uid_range); mac_label_context_free(c->label_context); } static void maybe_emit_login_defs_warning(Context *c) { assert(c); if (!c->login_defs_need_warning) return; if (c->login_defs.system_alloc_uid_min != SYSTEM_ALLOC_UID_MIN || c->login_defs.system_uid_max != SYSTEM_UID_MAX) log_warning("login.defs specifies UID allocation range "UID_FMT"–"UID_FMT " that is different than the built-in defaults ("UID_FMT"–"UID_FMT")", c->login_defs.system_alloc_uid_min, c->login_defs.system_uid_max, (uid_t) SYSTEM_ALLOC_UID_MIN, (uid_t) SYSTEM_UID_MAX); if (c->login_defs.system_alloc_gid_min != SYSTEM_ALLOC_GID_MIN || c->login_defs.system_gid_max != SYSTEM_GID_MAX) log_warning("login.defs specifies GID allocation range "GID_FMT"–"GID_FMT " that is different than the built-in defaults ("GID_FMT"–"GID_FMT")", c->login_defs.system_alloc_gid_min, c->login_defs.system_gid_max, (gid_t) SYSTEM_ALLOC_GID_MIN, (gid_t) SYSTEM_GID_MAX); c->login_defs_need_warning = false; } static void log_audit_accounts(Context *c, ItemType what) { #if HAVE_AUDIT assert(c); assert(IN_SET(what, ADD_USER, ADD_GROUP)); if (arg_dry_run || c->audit_fd < 0) return; Item *i; int type = what == ADD_USER ? AUDIT_ADD_USER : AUDIT_ADD_GROUP; const char *op = what == ADD_USER ? "adding-user" : "adding-group"; /* Notes: * * The op must not contain whitespace. The format with a dash matches what Fedora shadow-utils uses. * * We send id == -1, even though we know the number, in particular on success. This is because if we * send the id, the generated audit message will not contain the name. The name seems more useful * than the number, hence send just the name: * * type=ADD_USER msg=audit(01/10/2025 16:02:00.639:3854) : * pid=3846380 uid=root auid=zbyszek ses=2 msg='op=adding-user id=unknown(952) exe=systemd-sysusers ... res=success' * vs. * type=ADD_USER msg=audit(01/10/2025 16:03:15.457:3908) : * pid=3846607 uid=root auid=zbyszek ses=2 msg='op=adding-user acct=foo5 exe=systemd-sysusers ... res=success' */ ORDERED_HASHMAP_FOREACH(i, what == ADD_USER ? c->todo_uids : c->todo_gids) sym_audit_log_acct_message( c->audit_fd, type, program_invocation_short_name, op, i->name, /* id= */ (unsigned) -1, /* host= */ NULL, /* addr= */ NULL, /* tty= */ NULL, /* success= */ 1); #endif } static int load_user_database(Context *c) { _cleanup_free_ char *passwd_path = NULL; _cleanup_fclose_ FILE *f = NULL; struct passwd *pw; int r; assert(c); r = chase_and_fopen_unlocked("/etc/passwd", arg_root, CHASE_PREFIX_ROOT, "re", &passwd_path, &f); if (r == -ENOENT) return 0; if (r < 0) return r; while ((r = fgetpwent_sane(f, &pw)) > 0) { char *n = strdup(pw->pw_name); if (!n) return -ENOMEM; /* Note that we use trivial_hash_ops_free here, so identical strings can exist in the set. */ r = set_ensure_consume(&c->names, &trivial_hash_ops_free, n); if (r < 0) return r; assert(r > 0); /* The set uses pointer comparisons, so n must not be in the set. */ r = hashmap_ensure_put(&c->database_by_username, &string_hash_ops, n, UID_TO_PTR(pw->pw_uid)); if (r == -EEXIST) log_debug_errno(r, "%s: user '%s' is listed twice, ignoring duplicate uid.", passwd_path, n); else if (r < 0) return r; r = hashmap_ensure_put(&c->database_by_uid, /* hash_ops= */ NULL, UID_TO_PTR(pw->pw_uid), n); if (r == -EEXIST) log_debug_errno(r, "%s: uid "UID_FMT" is listed twice, ignoring duplicate name.", passwd_path, pw->pw_uid); else if (r < 0) return r; } return r; } static int load_group_database(Context *c) { _cleanup_free_ char *group_path = NULL; _cleanup_fclose_ FILE *f = NULL; struct group *gr; int r; assert(c); r = chase_and_fopen_unlocked("/etc/group", arg_root, CHASE_PREFIX_ROOT, "re", &group_path, &f); if (r == -ENOENT) return 0; if (r < 0) return r; while ((r = fgetgrent_sane(f, &gr)) > 0) { char *n = strdup(gr->gr_name); if (!n) return -ENOMEM; /* Note that we use trivial_hash_ops_free here, so identical strings can exist in the set. */ r = set_ensure_consume(&c->names, &trivial_hash_ops_free, n); if (r < 0) return r; assert(r > 0); /* The set uses pointer comparisons, so n must not be in the set. */ r = hashmap_ensure_put(&c->database_by_groupname, &string_hash_ops, n, GID_TO_PTR(gr->gr_gid)); if (r == -EEXIST) log_debug_errno(r, "%s: group '%s' is listed twice, ignoring duplicate gid.", group_path, n); else if (r < 0) return r; r = hashmap_ensure_put(&c->database_by_gid, /* hash_ops= */ NULL, GID_TO_PTR(gr->gr_gid), n); if (r == -EEXIST) log_debug_errno(r, "%s: gid "GID_FMT" is listed twice, ignoring duplicate name.", group_path, gr->gr_gid); else if (r < 0) return r; } return r; } static int make_backup(const char *target, const char *x, LabelContext *label_context) { _cleanup_(unlink_and_freep) char *dst_tmp = NULL; _cleanup_fclose_ FILE *dst = NULL; _cleanup_close_ int src = -EBADF; const char *backup; struct stat st; int r; assert(target); assert(x); src = open(x, O_RDONLY|O_CLOEXEC|O_NOCTTY); if (src < 0) { if (errno == ENOENT) /* No backup necessary... */ return 0; return -errno; } if (fstat(src, &st) < 0) return -errno; r = fopen_temporary_at_label( AT_FDCWD, target, /* The path for which to the look up the label */ x, /* Where we want the file actually to end up */ &dst, /* The temporary file we write to */ &dst_tmp, label_context); if (r < 0) return r; r = copy_bytes(src, fileno(dst), UINT64_MAX, /* copy_flags= */ 0); if (r < 0) return r; backup = strjoina(x, "-"); /* Copy over the access mask. Don't fail on chmod() or chown(). If it stays owned by us and/or * unreadable by others, then it isn't too bad... */ r = fchmod_and_chown_with_fallback(fileno(dst), dst_tmp, st.st_mode & 07777, st.st_uid, st.st_gid); if (r < 0) log_warning_errno(r, "Failed to change access mode or ownership of %s: %m", backup); if (futimens(fileno(dst), (const struct timespec[2]) { st.st_atim, st.st_mtim }) < 0) log_warning_errno(errno, "Failed to fix access and modification time of %s: %m", backup); r = fsync_full(fileno(dst)); if (r < 0) return r; if (rename(dst_tmp, backup) < 0) return -errno; dst_tmp = mfree(dst_tmp); /* disable the unlink_and_freep() hook now that the file has been renamed */ return 0; } static int putgrent_with_members( Context *c, const struct group *gr, FILE *group) { char **a; int r; assert(c); assert(gr); assert(group); a = ordered_hashmap_get(c->members, gr->gr_name); if (a) { _cleanup_strv_free_ char **l = NULL; bool added = false; l = strv_copy(gr->gr_mem); if (!l) return -ENOMEM; STRV_FOREACH(i, a) { if (strv_contains(l, *i)) continue; r = strv_extend(&l, *i); if (r < 0) return r; added = true; } if (added) { struct group t; strv_sort_uniq(l); t = *gr; t.gr_mem = l; r = putgrent_sane(&t, group); return r < 0 ? r : 1; } } return putgrent_sane(gr, group); } #if ENABLE_GSHADOW static int putsgent_with_members( Context *c, const struct sgrp *sg, FILE *gshadow) { char **a; int r; assert(sg); assert(gshadow); a = ordered_hashmap_get(c->members, sg->sg_namp); if (a) { _cleanup_strv_free_ char **l = NULL; bool added = false; l = strv_copy(sg->sg_mem); if (!l) return -ENOMEM; STRV_FOREACH(i, a) { if (strv_contains(l, *i)) continue; r = strv_extend(&l, *i); if (r < 0) return r; added = true; } if (added) { struct sgrp t; strv_sort_uniq(l); t = *sg; t.sg_mem = l; r = putsgent_sane(&t, gshadow); return r < 0 ? r : 1; } } return putsgent_sane(sg, gshadow); } #endif static const char* pick_shell(const Item *i) { assert(i); if (i->type != ADD_USER) return NULL; if (i->shell) return i->shell; if (i->uid_set && i->uid == 0) return default_root_shell(arg_root); return NOLOGIN; } static int read_shell_credential(const Item *i, char **ret) { _cleanup_free_ char *cn = NULL, *shell = NULL; int r; assert(i); cn = strjoin("passwd.shell.", i->name); if (!cn) return -ENOMEM; r = read_credential(cn, (void**) &shell, /* ret_size= */ NULL); if (r < 0) { log_debug_errno(r, "Couldn't read credential '%s', ignoring: %m", cn); if (ret) *ret = NULL; return 0; } path_simplify(shell); if (!valid_shell(shell)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Shell credential '%s' specifies invalid login shell '%s'.", cn, shell); if (ret) *ret = TAKE_PTR(shell); return 0; } static int write_temporary_passwd( Context *c, const char *passwd_path, FILE **ret_tmpfile, char **ret_tmpfile_path) { _cleanup_fclose_ FILE *original = NULL, *passwd = NULL; _cleanup_(unlink_and_freep) char *passwd_tmp = NULL; struct passwd *pw = NULL; Item *i; int r; assert(c); assert(ret_tmpfile); assert(ret_tmpfile_path); if (ordered_hashmap_isempty(c->todo_uids)) goto done; if (arg_dry_run) { ORDERED_HASHMAP_FOREACH(i, c->todo_uids) { r = read_shell_credential(i, /* ret= */ NULL); if (r < 0) return r; } log_info("Would write /etc/passwd%s", glyph(GLYPH_ELLIPSIS)); goto done; } r = fopen_temporary_at_label(AT_FDCWD, passwd_path, passwd_path, &passwd, &passwd_tmp, c->label_context); if (r < 0) return log_debug_errno(r, "Failed to open temporary copy of %s: %m", passwd_path); original = fopen(passwd_path, "re"); if (original) { /* Allow fallback path for when /proc is not mounted. On any normal system /proc will be * mounted, but e.g. when 'dnf --installroot' is used, it might not be. There is no security * relevance here, since the environment is ultimately trusted, and not requiring /proc makes * it easier to depend on sysusers in packaging scripts and suchlike. */ r = copy_rights_with_fallback(fileno(original), fileno(passwd), passwd_tmp); if (r < 0) return log_debug_errno(r, "Failed to copy permissions from %s to %s: %m", passwd_path, passwd_tmp); while ((r = fgetpwent_sane(original, &pw)) > 0) { i = ordered_hashmap_get(c->users, pw->pw_name); if (i && i->todo_user) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "%s: User \"%s\" already exists.", passwd_path, pw->pw_name); if (ordered_hashmap_contains(c->todo_uids, UID_TO_PTR(pw->pw_uid))) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "%s: Detected collision for UID " UID_FMT ".", passwd_path, pw->pw_uid); /* Make sure we keep the NIS entries (if any) at the end. */ if (IN_SET(pw->pw_name[0], '+', '-')) break; r = putpwent_sane(pw, passwd); if (r < 0) return log_debug_errno(r, "Failed to add existing user \"%s\" to temporary passwd file: %m", pw->pw_name); } if (r < 0) return log_debug_errno(r, "Failed to read %s: %m", passwd_path); } else { if (errno != ENOENT) return log_debug_errno(errno, "Failed to open %s: %m", passwd_path); if (fchmod(fileno(passwd), 0644) < 0) return log_debug_errno(errno, "Failed to fchmod %s: %m", passwd_tmp); } ORDERED_HASHMAP_FOREACH(i, c->todo_uids) { _cleanup_free_ char *creds_shell = NULL; struct passwd n = { .pw_name = i->name, .pw_uid = i->uid, .pw_gid = i->gid, .pw_gecos = (char*) strempty(i->description), /* "x" means the password is stored in the shadow file */ .pw_passwd = (char*) PASSWORD_SEE_SHADOW, /* We default to the root directory as home */ .pw_dir = i->home ?: (char*) "/", /* Initialize the shell to nologin, with one exception: * for root we patch in something special */ .pw_shell = (char*) pick_shell(i), }; r = read_shell_credential(i, &creds_shell); if (r < 0) return r; if (creds_shell) n.pw_shell = creds_shell; r = putpwent_sane(&n, passwd); if (r < 0) return log_debug_errno(r, "Failed to add new user \"%s\" to temporary passwd file: %m", i->name); } /* Append the remaining NIS entries if any */ while (pw) { r = putpwent_sane(pw, passwd); if (r < 0) return log_debug_errno(r, "Failed to add existing user \"%s\" to temporary passwd file: %m", pw->pw_name); r = fgetpwent_sane(original, &pw); if (r < 0) return log_debug_errno(r, "Failed to read %s: %m", passwd_path); if (r == 0) break; } r = fflush_sync_and_check(passwd); if (r < 0) return log_debug_errno(r, "Failed to flush %s: %m", passwd_tmp); done: *ret_tmpfile = TAKE_PTR(passwd); *ret_tmpfile_path = TAKE_PTR(passwd_tmp); return 0; } static int write_temporary_shadow( Context *c, const char *shadow_path, FILE **ret_tmpfile, char **ret_tmpfile_path) { _cleanup_fclose_ FILE *original = NULL, *shadow = NULL; _cleanup_(unlink_and_freep) char *shadow_tmp = NULL; struct spwd *sp = NULL; long lstchg; Item *i; int r; assert(c); assert(ret_tmpfile); assert(ret_tmpfile_path); if (ordered_hashmap_isempty(c->todo_uids)) goto done; if (arg_dry_run) { log_info("Would write /etc/shadow%s", glyph(GLYPH_ELLIPSIS)); goto done; } r = fopen_temporary_at_label(AT_FDCWD, shadow_path, shadow_path, &shadow, &shadow_tmp, c->label_context); if (r < 0) return log_debug_errno(r, "Failed to open temporary copy of %s: %m", shadow_path); lstchg = (long) (source_date_epoch_or_now() / USEC_PER_DAY); original = fopen(shadow_path, "re"); if (original) { r = copy_rights_with_fallback(fileno(original), fileno(shadow), shadow_tmp); if (r < 0) return log_debug_errno(r, "Failed to copy permissions from %s to %s: %m", shadow_path, shadow_tmp); while ((r = fgetspent_sane(original, &sp)) > 0) { i = ordered_hashmap_get(c->users, sp->sp_namp); if (i && i->todo_user) { /* we will update the existing entry */ sp->sp_lstchg = lstchg; /* only the /etc/shadow stage is left, so we can * safely remove the item from the todo set */ i->todo_user = false; ordered_hashmap_remove(c->todo_uids, UID_TO_PTR(i->uid)); } /* Make sure we keep the NIS entries (if any) at the end. */ if (IN_SET(sp->sp_namp[0], '+', '-')) break; r = putspent_sane(sp, shadow); if (r < 0) return log_debug_errno(r, "Failed to add existing user \"%s\" to temporary shadow file: %m", sp->sp_namp); } if (r < 0) return log_debug_errno(r, "Failed to read %s: %m", shadow_path); } else { if (errno != ENOENT) return log_debug_errno(errno, "Failed to open %s: %m", shadow_path); if (fchmod(fileno(shadow), 0000) < 0) return log_debug_errno(errno, "Failed to fchmod %s: %m", shadow_tmp); } ORDERED_HASHMAP_FOREACH(i, c->todo_uids) { _cleanup_(erase_and_freep) char *creds_password = NULL; bool is_hashed; struct spwd n = { .sp_namp = i->name, .sp_lstchg = lstchg, .sp_min = -1, .sp_max = -1, .sp_warn = -1, .sp_inact = -1, .sp_expire = i->locked ? 1 : -1, /* Negative expiration means "unset". Expiration 0 or 1 means "locked" */ .sp_flag = ULONG_MAX, /* this appears to be what everybody does ... */ }; r = get_credential_user_password(i->name, &creds_password, &is_hashed); if (r < 0) log_debug_errno(r, "Couldn't read password credential for user '%s', ignoring: %m", i->name); if (creds_password && !is_hashed) { _cleanup_(erase_and_freep) char* plaintext_password = TAKE_PTR(creds_password); r = hash_password(plaintext_password, &creds_password); if (r < 0) return log_debug_errno(r, "Failed to hash password: %m"); } if (creds_password) n.sp_pwdp = creds_password; else if (streq(i->name, "root")) /* Let firstboot set the password later */ n.sp_pwdp = (char*) PASSWORD_UNPROVISIONED; else n.sp_pwdp = (char*) PASSWORD_LOCKED_AND_INVALID; r = putspent_sane(&n, shadow); if (r < 0) return log_debug_errno(r, "Failed to add new user \"%s\" to temporary shadow file: %m", i->name); } /* Append the remaining NIS entries if any */ while (sp) { r = putspent_sane(sp, shadow); if (r < 0) return log_debug_errno(r, "Failed to add existing user \"%s\" to temporary shadow file: %m", sp->sp_namp); r = fgetspent_sane(original, &sp); if (r < 0) return log_debug_errno(r, "Failed to read %s: %m", shadow_path); if (r == 0) break; } if (!IN_SET(errno, 0, ENOENT)) return -errno; r = fflush_sync_and_check(shadow); if (r < 0) return log_debug_errno(r, "Failed to flush %s: %m", shadow_tmp); done: *ret_tmpfile = TAKE_PTR(shadow); *ret_tmpfile_path = TAKE_PTR(shadow_tmp); return 0; } static int write_temporary_group( Context *c, const char *group_path, FILE **ret_tmpfile, char **ret_tmpfile_path) { _cleanup_fclose_ FILE *original = NULL, *group = NULL; _cleanup_(unlink_and_freep) char *group_tmp = NULL; bool group_changed = false; struct group *gr = NULL; Item *i; int r; assert(c); assert(ret_tmpfile); assert(ret_tmpfile_path); if (ordered_hashmap_isempty(c->todo_gids) && ordered_hashmap_isempty(c->members)) goto done; if (arg_dry_run) { log_info("Would write /etc/group%s", glyph(GLYPH_ELLIPSIS)); goto done; } r = fopen_temporary_at_label(AT_FDCWD, group_path, group_path, &group, &group_tmp, c->label_context); if (r < 0) return log_error_errno(r, "Failed to open temporary copy of %s: %m", group_path); original = fopen(group_path, "re"); if (original) { r = copy_rights_with_fallback(fileno(original), fileno(group), group_tmp); if (r < 0) return log_error_errno(r, "Failed to copy permissions from %s to %s: %m", group_path, group_tmp); while ((r = fgetgrent_sane(original, &gr)) > 0) { /* Safety checks against name and GID collisions. Normally, * this should be unnecessary, but given that we look at the * entries anyway here, let's make an extra verification * step that we don't generate duplicate entries. */ i = ordered_hashmap_get(c->groups, gr->gr_name); if (i && i->todo_group) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "%s: Group \"%s\" already exists.", group_path, gr->gr_name); if (ordered_hashmap_contains(c->todo_gids, GID_TO_PTR(gr->gr_gid))) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "%s: Detected collision for GID " GID_FMT ".", group_path, gr->gr_gid); /* Make sure we keep the NIS entries (if any) at the end. */ if (IN_SET(gr->gr_name[0], '+', '-')) break; r = putgrent_with_members(c, gr, group); if (r < 0) return log_error_errno(r, "Failed to add existing group \"%s\" to temporary group file: %m", gr->gr_name); if (r > 0) group_changed = true; } if (r < 0) return log_error_errno(r, "Failed to read %s: %m", group_path); } else { if (errno != ENOENT) return log_error_errno(errno, "Failed to open %s: %m", group_path); if (fchmod(fileno(group), 0644) < 0) return log_error_errno(errno, "Failed to fchmod %s: %m", group_tmp); } ORDERED_HASHMAP_FOREACH(i, c->todo_gids) { struct group n = { .gr_name = i->name, .gr_gid = i->gid, .gr_passwd = (char*) PASSWORD_SEE_SHADOW, }; r = putgrent_with_members(c, &n, group); if (r < 0) return log_error_errno(r, "Failed to add new group \"%s\" to temporary group file: %m", n.gr_name); group_changed = true; } /* Append the remaining NIS entries if any */ while (gr) { r = putgrent_sane(gr, group); if (r < 0) return log_error_errno(r, "Failed to add existing group \"%s\" to temporary group file: %m", gr->gr_name); r = fgetgrent_sane(original, &gr); if (r < 0) return log_error_errno(r, "Failed to read %s: %m", group_path); if (r == 0) break; } r = fflush_sync_and_check(group); if (r < 0) return log_error_errno(r, "Failed to flush %s: %m", group_tmp); done: if (group_changed) { *ret_tmpfile = TAKE_PTR(group); *ret_tmpfile_path = TAKE_PTR(group_tmp); } else { *ret_tmpfile = NULL; *ret_tmpfile_path = NULL; } return 0; } static int write_temporary_gshadow( Context *c, const char * gshadow_path, FILE **ret_tmpfile, char **ret_tmpfile_path) { #if ENABLE_GSHADOW _cleanup_fclose_ FILE *original = NULL, *gshadow = NULL; _cleanup_(unlink_and_freep) char *gshadow_tmp = NULL; bool group_changed = false; Item *i; int r; assert(c); assert(ret_tmpfile); assert(ret_tmpfile_path); if (ordered_hashmap_isempty(c->todo_gids) && ordered_hashmap_isempty(c->members)) goto done; if (arg_dry_run) { log_info("Would write /etc/gshadow%s", glyph(GLYPH_ELLIPSIS)); goto done; } r = fopen_temporary_at_label(AT_FDCWD, gshadow_path, gshadow_path, &gshadow, &gshadow_tmp, c->label_context); if (r < 0) return log_error_errno(r, "Failed to open temporary copy of %s: %m", gshadow_path); original = fopen(gshadow_path, "re"); if (original) { struct sgrp *sg; r = copy_rights_with_fallback(fileno(original), fileno(gshadow), gshadow_tmp); if (r < 0) return log_error_errno(r, "Failed to copy permissions from %s to %s: %m", gshadow_path, gshadow_tmp); while ((r = fgetsgent_sane(original, &sg)) > 0) { i = ordered_hashmap_get(c->groups, sg->sg_namp); if (i && i->todo_group) { /* The group already exists in /etc/gshadow. Only the * /etc/gshadow stage is left, so we can safely remove * the item from the todo set. */ i->todo_group = false; ordered_hashmap_remove(c->todo_gids, GID_TO_PTR(i->gid)); } r = putsgent_with_members(c, sg, gshadow); if (r < 0) return log_error_errno(r, "Failed to add existing group \"%s\" to temporary gshadow file: %m", sg->sg_namp); if (r > 0) group_changed = true; } if (r < 0) return r; } else { if (errno != ENOENT) return log_error_errno(errno, "Failed to open %s: %m", gshadow_path); if (fchmod(fileno(gshadow), 0000) < 0) return log_error_errno(errno, "Failed to fchmod %s: %m", gshadow_tmp); } ORDERED_HASHMAP_FOREACH(i, c->todo_gids) { struct sgrp n = { .sg_namp = i->name, .sg_passwd = (char*) PASSWORD_LOCKED_AND_INVALID, }; r = putsgent_with_members(c, &n, gshadow); if (r < 0) return log_error_errno(r, "Failed to add new group \"%s\" to temporary gshadow file: %m", n.sg_namp); group_changed = true; } r = fflush_sync_and_check(gshadow); if (r < 0) return log_error_errno(r, "Failed to flush %s: %m", gshadow_tmp); done: if (group_changed) { *ret_tmpfile = TAKE_PTR(gshadow); *ret_tmpfile_path = TAKE_PTR(gshadow_tmp); } else #endif { *ret_tmpfile = NULL; *ret_tmpfile_path = NULL; } return 0; } static int write_files(Context *c) { _cleanup_fclose_ FILE *passwd = NULL, *group = NULL, *shadow = NULL, *gshadow = NULL; _cleanup_(unlink_and_freep) char *passwd_tmp = NULL, *group_tmp = NULL, *shadow_tmp = NULL, *gshadow_tmp = NULL; int r; _cleanup_free_ char *passwd_path = path_join(arg_root, "/etc/passwd"); if (!passwd_path) return log_oom(); _cleanup_free_ char *shadow_path = path_join(arg_root, "/etc/shadow"); if (!shadow_path) return log_oom(); _cleanup_free_ char *group_path = path_join(arg_root, "/etc/group"); if (!group_path) return log_oom(); _cleanup_free_ char *gshadow_path = path_join(arg_root, "/etc/gshadow"); if (!gshadow_path) return log_oom(); assert(c); r = write_temporary_group(c, group_path, &group, &group_tmp); if (r < 0) return r; r = write_temporary_gshadow(c, gshadow_path, &gshadow, &gshadow_tmp); if (r < 0) return r; r = write_temporary_passwd(c, passwd_path, &passwd, &passwd_tmp); if (r < 0) return r; r = write_temporary_shadow(c, shadow_path, &shadow, &shadow_tmp); if (r < 0) return r; /* Make a backup of the old files */ if (group) { r = make_backup(group_path, group_path, c->label_context); if (r < 0) return log_error_errno(r, "Failed to backup %s: %m", group_path); } if (gshadow) { r = make_backup(gshadow_path, gshadow_path, c->label_context); if (r < 0) return log_error_errno(r, "Failed to backup %s: %m", gshadow_path); } if (passwd) { r = make_backup(passwd_path, passwd_path, c->label_context); if (r < 0) return log_error_errno(r, "Failed to backup %s: %m", passwd_path); } if (shadow) { r = make_backup(shadow_path, shadow_path, c->label_context); if (r < 0) return log_error_errno(r, "Failed to backup %s: %m", shadow_path); } /* And make the new files count */ if (group) { r = rename_and_apply_smack_floor_label(group_tmp, group_path); if (r < 0) return log_error_errno(r, "Failed to rename %s to %s: %m", group_tmp, group_path); group_tmp = mfree(group_tmp); } /* OK, we have written the group entries successfully */ log_audit_accounts(c, ADD_GROUP); if (gshadow) { r = rename_and_apply_smack_floor_label(gshadow_tmp, gshadow_path); if (r < 0) return log_error_errno(r, "Failed to rename %s to %s: %m", gshadow_tmp, gshadow_path); gshadow_tmp = mfree(gshadow_tmp); } if (passwd) { r = rename_and_apply_smack_floor_label(passwd_tmp, passwd_path); if (r < 0) return log_error_errno(r, "Failed to rename %s to %s: %m", passwd_tmp, passwd_path); passwd_tmp = mfree(passwd_tmp); } /* OK, we have written the user entries successfully */ log_audit_accounts(c, ADD_USER); if (shadow) { r = rename_and_apply_smack_floor_label(shadow_tmp, shadow_path); if (r < 0) return log_error_errno(r, "Failed to rename %s to %s: %m", shadow_tmp, shadow_path); shadow_tmp = mfree(shadow_tmp); } return 0; } static int uid_is_ok( Context *c, uid_t uid, const char *name, bool check_with_gid) { int r; assert(c); /* Let's see if we already have assigned the UID a second time */ if (ordered_hashmap_contains(c->todo_uids, UID_TO_PTR(uid))) return 0; /* Try to avoid using uids that are already used by a group * that doesn't have the same name as our new user. */ if (check_with_gid) { Item *i; i = ordered_hashmap_get(c->todo_gids, GID_TO_PTR(uid)); if (i && !streq(i->name, name)) return 0; } /* Let's check the files directly */ if (hashmap_contains(c->database_by_uid, UID_TO_PTR(uid))) return 0; if (check_with_gid) { const char *n; n = hashmap_get(c->database_by_gid, GID_TO_PTR(uid)); if (n && !streq(n, name)) return 0; } /* Let's also check via NSS, to avoid UID clashes over LDAP and such, just in case */ if (!arg_root) { _cleanup_free_ struct group *g = NULL; r = getpwuid_malloc(uid, /* ret= */ NULL); if (r >= 0) return 0; if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up UID '" UID_FMT "' via NSS, assuming it doesn't exist: %m", uid); if (check_with_gid) { r = getgrgid_malloc((gid_t) uid, &g); if (r >= 0) { if (!streq(g->gr_name, name)) return 0; } else if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up GID '" GID_FMT "' via NSS, assuming it doesn't exist: %m", uid); } } return 1; } static int root_stat(const char *p, struct stat *ret_st) { return chase_and_stat(p, arg_root, CHASE_PREFIX_ROOT, /* ret_path= */ NULL, ret_st); } static int read_id_from_file(Item *i, uid_t *ret_uid, gid_t *ret_gid) { struct stat st; bool found_uid = false, found_gid = false; uid_t uid = 0; gid_t gid = 0; assert(i); /* First, try to get the GID directly */ if (ret_gid && i->gid_path && root_stat(i->gid_path, &st) >= 0) { gid = st.st_gid; found_gid = true; } /* Then, try to get the UID directly */ if ((ret_uid || (ret_gid && !found_gid)) && i->uid_path && root_stat(i->uid_path, &st) >= 0) { uid = st.st_uid; found_uid = true; /* If we need the gid, but had no success yet, also derive it from the UID path */ if (ret_gid && !found_gid) { gid = st.st_gid; found_gid = true; } } /* If that didn't work yet, then let's reuse the GID as UID */ if (ret_uid && !found_uid && i->gid_path) { if (found_gid) { uid = (uid_t) gid; found_uid = true; } else if (root_stat(i->gid_path, &st) >= 0) { uid = (uid_t) st.st_gid; found_uid = true; } } if (ret_uid) { if (!found_uid) return 0; *ret_uid = uid; } if (ret_gid) { if (!found_gid) return 0; *ret_gid = gid; } return 1; } static int add_user(Context *c, Item *i) { void *z; int r; assert(c); assert(i); /* Check the database directly */ z = hashmap_get(c->database_by_username, i->name); if (z) { log_debug("User %s already exists.", i->name); i->uid = PTR_TO_UID(z); i->uid_set = true; return 0; } if (!arg_root) { _cleanup_free_ struct passwd *p = NULL; /* Also check NSS */ r = getpwnam_malloc(i->name, &p); if (r >= 0) { log_debug("User %s already exists.", i->name); i->uid = p->pw_uid; i->uid_set = true; r = free_and_strdup(&i->description, p->pw_gecos); if (r < 0) return log_oom(); return 0; } if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up user '%s' via NSS, assuming it doesn't exist: %m", i->name); } /* Try to use the suggested numeric UID */ if (i->uid_set) { r = uid_is_ok(c, i->uid, i->name, !i->id_set_strict); if (r < 0) return log_error_errno(r, "Failed to verify UID " UID_FMT ": %m", i->uid); if (r == 0) { log_info("Suggested user ID " UID_FMT " for %s already used.", i->uid, i->name); i->uid_set = false; } } /* If that didn't work, try to read it from the specified path */ if (!i->uid_set) { uid_t candidate; if (read_id_from_file(i, &candidate, NULL) > 0) { if (candidate <= 0 || !uid_range_contains(c->uid_range, candidate)) log_debug("User ID " UID_FMT " of file not suitable for %s.", candidate, i->name); else { r = uid_is_ok(c, candidate, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify UID " UID_FMT ": %m", i->uid); else if (r > 0) { i->uid = candidate; i->uid_set = true; } else log_debug("User ID " UID_FMT " of file for %s is already used.", candidate, i->name); } } } /* Otherwise, try to reuse the group ID */ if (!i->uid_set && i->gid_set) { r = uid_is_ok(c, (uid_t) i->gid, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify UID " UID_FMT ": %m", i->uid); if (r > 0) { i->uid = (uid_t) i->gid; i->uid_set = true; } } /* And if that didn't work either, let's try to find a free one */ if (!i->uid_set) { maybe_emit_login_defs_warning(c); for (;;) { r = uid_range_next_lower(c->uid_range, &c->search_uid); if (r < 0) return log_error_errno(r, "No free user ID available for %s.", i->name); r = uid_is_ok(c, c->search_uid, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify UID " UID_FMT ": %m", i->uid); else if (r > 0) break; } i->uid_set = true; i->uid = c->search_uid; } r = ordered_hashmap_ensure_put(&c->todo_uids, NULL, UID_TO_PTR(i->uid), i); if (r == -EEXIST) return log_error_errno(r, "Requested user %s with UID " UID_FMT " and gid" GID_FMT " to be created is duplicated " "or conflicts with another user.", i->name, i->uid, i->gid); if (r == -ENOMEM) return log_oom(); if (r < 0) return log_error_errno(r, "Failed to store user %s with UID " UID_FMT " and GID " GID_FMT " to be created: %m", i->name, i->uid, i->gid); i->todo_user = true; log_info("Creating user '%s' (%s) with UID " UID_FMT " and GID " GID_FMT ".", i->name, strna(i->description), i->uid, i->gid); return 0; } static int gid_is_ok( Context *c, gid_t gid, const char *groupname, bool check_with_uid) { Item *user; char *username; int r; assert(c); assert(groupname); if (ordered_hashmap_contains(c->todo_gids, GID_TO_PTR(gid))) return 0; /* Avoid reusing gids that are already used by a different user */ if (check_with_uid) { user = ordered_hashmap_get(c->todo_uids, UID_TO_PTR(gid)); if (user && !streq(user->name, groupname)) return 0; } if (hashmap_contains(c->database_by_gid, GID_TO_PTR(gid))) return 0; if (check_with_uid) { username = hashmap_get(c->database_by_uid, UID_TO_PTR(gid)); if (username && !streq(username, groupname)) return 0; } if (!arg_root) { r = getgrgid_malloc(gid, /* ret= */ NULL); if (r >= 0) return 0; if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up GID '" GID_FMT "' via NSS, assuming it doesn't exist: %m", gid); if (check_with_uid) { r = getpwuid_malloc(gid, /* ret= */ NULL); if (r >= 0) return 0; if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up GID '" GID_FMT "' via NSS, assuming it doesn't exist: %m", gid); } } return 1; } static int get_gid_by_name( Context *c, const char *name, gid_t *ret_gid) { void *z; int r; assert(c); assert(ret_gid); /* Check the database directly */ z = hashmap_get(c->database_by_groupname, name); if (z) { *ret_gid = PTR_TO_GID(z); return 0; } /* Also check NSS */ if (!arg_root) { _cleanup_free_ struct group *g = NULL; r = getgrnam_malloc(name, &g); if (r >= 0) { *ret_gid = g->gr_gid; return 0; } if (r != -ESRCH) log_warning_errno(r, "Unexpected failure while looking up group '%s' via NSS, assuming it doesn't exist: %m", name); } return -ENOENT; } static int add_group(Context *c, Item *i) { int r; assert(c); assert(i); r = get_gid_by_name(c, i->name, &i->gid); if (r != -ENOENT) { if (r < 0) return r; log_debug("Group %s already exists.", i->name); i->gid_set = true; return 0; } /* Try to use the suggested numeric GID */ if (i->gid_set) { r = gid_is_ok(c, i->gid, i->name, false); if (r < 0) return log_error_errno(r, "Failed to verify GID " GID_FMT ": %m", i->gid); if (i->id_set_strict) { /* If we require the GID to already exist we can return here: * r > 0: means the GID does not exist -> fail * r == 0: means the GID exists -> nothing more to do. */ if (r > 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to create %s: please create GID " GID_FMT, i->name, i->gid); if (r == 0) return 0; } if (r == 0) { log_info("Suggested group ID " GID_FMT " for %s already used.", i->gid, i->name); i->gid_set = false; } } /* Try to reuse the numeric uid, if there's one */ if (!i->gid_set && i->uid_set) { r = gid_is_ok(c, (gid_t) i->uid, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify GID " GID_FMT ": %m", i->gid); if (r > 0) { i->gid = (gid_t) i->uid; i->gid_set = true; } } /* If that didn't work, try to read it from the specified path */ if (!i->gid_set) { gid_t candidate; if (read_id_from_file(i, NULL, &candidate) > 0) { if (candidate <= 0 || !uid_range_contains(c->uid_range, candidate)) log_debug("Group ID " GID_FMT " of file not suitable for %s.", candidate, i->name); else { r = gid_is_ok(c, candidate, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify GID " GID_FMT ": %m", i->gid); else if (r > 0) { i->gid = candidate; i->gid_set = true; } else log_debug("Group ID " GID_FMT " of file for %s already used.", candidate, i->name); } } } /* And if that didn't work either, let's try to find a free one */ if (!i->gid_set) { maybe_emit_login_defs_warning(c); for (;;) { /* We look for new GIDs in the UID pool! */ r = uid_range_next_lower(c->uid_range, &c->search_uid); if (r < 0) return log_error_errno(r, "No free group ID available for %s.", i->name); r = gid_is_ok(c, c->search_uid, i->name, true); if (r < 0) return log_error_errno(r, "Failed to verify GID " GID_FMT ": %m", i->gid); else if (r > 0) break; } i->gid_set = true; i->gid = c->search_uid; } r = ordered_hashmap_ensure_put(&c->todo_gids, NULL, GID_TO_PTR(i->gid), i); if (r == -EEXIST) return log_error_errno(r, "Requested group %s with GID "GID_FMT " to be created is duplicated or conflicts with another user.", i->name, i->gid); if (r == -ENOMEM) return log_oom(); if (r < 0) return log_error_errno(r, "Failed to store group %s with GID " GID_FMT " to be created: %m", i->name, i->gid); i->todo_group = true; log_info("Creating group '%s' with GID " GID_FMT ".", i->name, i->gid); return 0; } static int process_item(Context *c, Item *i) { int r; assert(c); assert(i); switch (i->type) { case ADD_USER: { Item *j = NULL; if (!i->gid_set) { j = ordered_hashmap_get(c->groups, i->group_name ?: i->name); /* If that's not a match, also check if the group name * matches a user name in the queue. */ if (!j && i->group_name) j = ordered_hashmap_get(c->users, i->group_name); } if (j && j->todo_group) { /* When a group with the target name is already in queue, * use the information about the group and do not create * duplicated group entry. */ i->gid_set = j->gid_set; i->gid = j->gid; i->id_set_strict = true; } else if (i->group_name) { /* When a group name was given instead of a GID and it's * not in queue, then it must already exist. */ r = get_gid_by_name(c, i->group_name, &i->gid); if (r < 0) return log_error_errno(r, "Group %s not found.", i->group_name); i->gid_set = true; i->id_set_strict = true; } else { r = add_group(c, i); if (r < 0) return r; } return add_user(c, i); } case ADD_GROUP: return add_group(c, i); default: assert_not_reached(); } } static Item* item_free(Item *i) { if (!i) return NULL; free(i->name); free(i->group_name); free(i->uid_path); free(i->gid_path); free(i->description); free(i->home); free(i->shell); free(i->filename); return mfree(i); } DEFINE_TRIVIAL_CLEANUP_FUNC(Item*, item_free); DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(item_hash_ops, char, string_hash_func, string_compare_func, Item, item_free); static Item* item_new(ItemType type, const char *name, const char *filename, unsigned line) { assert(name); assert(!!filename == (line > 0)); _cleanup_(item_freep) Item *new = new(Item, 1); if (!new) return NULL; *new = (Item) { .type = type, .line = line, }; if (free_and_strdup(&new->name, name) < 0 || free_and_strdup(&new->filename, filename) < 0) return NULL; return TAKE_PTR(new); } static int add_implicit(Context *c) { char *g, **l; int r; assert(c); /* Implicitly create additional users and groups, if they were listed in "m" lines */ ORDERED_HASHMAP_FOREACH_KEY(l, g, c->members) { STRV_FOREACH(m, l) if (!ordered_hashmap_contains(c->users, *m)) { _cleanup_(item_freep) Item *j = item_new(ADD_USER, *m, /* filename= */ NULL, /* line= */ 0); if (!j) return log_oom(); r = ordered_hashmap_ensure_put(&c->users, &item_hash_ops, j->name, j); if (r == -ENOMEM) return log_oom(); if (r < 0) return log_error_errno(r, "Failed to add implicit user '%s': %m", j->name); log_debug("Adding implicit user '%s' due to m line", j->name); TAKE_PTR(j); } if (!(ordered_hashmap_contains(c->users, g) || ordered_hashmap_contains(c->groups, g))) { _cleanup_(item_freep) Item *j = item_new(ADD_GROUP, g, /* filename= */ NULL, /* line= */ 0); if (!j) return log_oom(); r = ordered_hashmap_ensure_put(&c->groups, &item_hash_ops, j->name, j); if (r == -ENOMEM) return log_oom(); if (r < 0) return log_error_errno(r, "Failed to add implicit group '%s': %m", j->name); log_debug("Adding implicit group '%s' due to m line", j->name); TAKE_PTR(j); } } return 0; } static int item_equivalent(Item *a, Item *b) { int r; assert(a); assert(b); if (a->type != b->type) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because types differ"); return false; } if (!streq_ptr(a->name, b->name)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because names differ ('%s' vs. '%s')", a->name, b->name); return false; } /* Paths were simplified previously, so we can use streq. */ if (!streq_ptr(a->uid_path, b->uid_path)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because UID paths differ (%s vs. %s)", a->uid_path ?: "(unset)", b->uid_path ?: "(unset)"); return false; } if (!streq_ptr(a->gid_path, b->gid_path)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because GID paths differ (%s vs. %s)", a->gid_path ?: "(unset)", b->gid_path ?: "(unset)"); return false; } if (!streq_ptr(a->description, b->description)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because descriptions differ ('%s' vs. '%s')", strempty(a->description), strempty(b->description)); return false; } if ((a->uid_set != b->uid_set) || (a->uid_set && a->uid != b->uid)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because UIDs differ (%s vs. %s)", a->uid_set ? FORMAT_UID(a->uid) : "(unset)", b->uid_set ? FORMAT_UID(b->uid) : "(unset)"); return false; } if ((a->gid_set != b->gid_set) || (a->gid_set && a->gid != b->gid)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because GIDs differ (%s vs. %s)", a->gid_set ? FORMAT_GID(a->gid) : "(unset)", b->gid_set ? FORMAT_GID(b->gid) : "(unset)"); return false; } if (!streq_ptr(a->home, b->home)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because home directories differ ('%s' vs. '%s')", strempty(a->description), strempty(b->description)); return false; } /* Check if the two paths refer to the same file. * If the paths are equal (after normalization), it's obviously the same file. * If both paths specify a nologin shell, treat them as the same (e.g. /bin/true and /bin/false). * Otherwise, try to resolve the paths, and see if we get the same result, (e.g. /sbin/nologin and * /usr/sbin/nologin). * If we can't resolve something, treat different paths as different. */ const char *a_shell = pick_shell(a), *b_shell = pick_shell(b); if (!path_equal(a_shell, b_shell) && !(is_nologin_shell(a_shell) && is_nologin_shell(b_shell))) { _cleanup_free_ char *pa = NULL, *pb = NULL; r = chase(a_shell, arg_root, CHASE_PREFIX_ROOT | CHASE_NONEXISTENT, &pa, NULL); if (r < 0) { log_full_errno(ERRNO_IS_RESOURCE(r) ? LOG_ERR : LOG_DEBUG, r, "Failed to look up path '%s%s%s': %m", strempty(arg_root), arg_root ? "/" : "", a_shell); return ERRNO_IS_RESOURCE(r) ? r : false; } r = chase(b_shell, arg_root, CHASE_PREFIX_ROOT | CHASE_NONEXISTENT, &pb, NULL); if (r < 0) { log_full_errno(ERRNO_IS_RESOURCE(r) ? LOG_ERR : LOG_DEBUG, r, "Failed to look up path '%s%s%s': %m", strempty(arg_root), arg_root ? "/" : "", b_shell); return ERRNO_IS_RESOURCE(r) ? r : false; } if (!path_equal(pa, pb)) { log_syntax(NULL, LOG_DEBUG, a->filename, a->line, 0, "Item not equivalent because shells differ ('%s' vs. '%s')", pa, pb); return false; } } return true; } static int parse_line( const char *fname, unsigned line, const char *buffer, bool *invalid_config, void *context) { Context *c = ASSERT_PTR(context); _cleanup_free_ char *action = NULL, *name = NULL, *resolved_name = NULL, *id = NULL, *resolved_id = NULL, *description = NULL, *resolved_description = NULL, *home = NULL, *resolved_home = NULL, *shell = NULL, *resolved_shell = NULL; _cleanup_(item_freep) Item *i = NULL; Item *existing; OrderedHashmap *h; int r; const char *p; assert(fname); assert(line >= 1); assert(buffer); assert(!invalid_config); /* We don't support invalid_config yet. */ /* Parse columns */ p = buffer; r = extract_many_words(&p, NULL, EXTRACT_UNQUOTE, &action, &name, &id, &description, &home, &shell); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Syntax error."); if (r < 2) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Missing action and name columns."); if (!isempty(p)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Trailing garbage."); if (isempty(action)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EBADMSG), "Empty command specification."); bool locked = false; for (int pos = 1; action[pos]; pos++) if (action[pos] == '!' && !locked) locked = true; else return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EBADMSG), "Unknown modifiers in command '%s'.", action); if (!IN_SET(action[0], ADD_USER, ADD_GROUP, ADD_MEMBER, ADD_RANGE)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EBADMSG), "Unknown command type '%c'.", action[0]); /* Verify name */ if (empty_or_dash(name)) name = mfree(name); if (name) { r = specifier_printf(name, NAME_MAX, system_and_tmp_specifier_table, arg_root, NULL, &resolved_name); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to replace specifiers in '%s': %m", name); if (!valid_user_group_name(resolved_name, 0)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "'%s' is not a valid user or group name.", resolved_name); } /* Verify id */ if (empty_or_dash(id)) id = mfree(id); if (id) { r = specifier_printf(id, PATH_MAX-1, system_and_tmp_specifier_table, arg_root, NULL, &resolved_id); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to replace specifiers in '%s': %m", name); } /* Verify description */ if (empty_or_dash(description)) description = mfree(description); if (description) { r = specifier_printf(description, LONG_LINE_MAX, system_and_tmp_specifier_table, arg_root, NULL, &resolved_description); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to replace specifiers in '%s': %m", description); if (!valid_gecos(resolved_description)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "'%s' is not a valid GECOS field.", resolved_description); } /* Verify home */ if (empty_or_dash(home)) home = mfree(home); if (home) { r = specifier_printf(home, PATH_MAX-1, system_and_tmp_specifier_table, arg_root, NULL, &resolved_home); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to replace specifiers in '%s': %m", home); path_simplify(resolved_home); if (!valid_home(resolved_home)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "'%s' is not a valid home directory field.", resolved_home); } /* Verify shell */ if (empty_or_dash(shell)) shell = mfree(shell); if (shell) { r = specifier_printf(shell, PATH_MAX-1, system_and_tmp_specifier_table, arg_root, NULL, &resolved_shell); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to replace specifiers in '%s': %m", shell); path_simplify(resolved_shell); if (!valid_shell(resolved_shell)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "'%s' is not a valid login shell field.", resolved_shell); } switch (action[0]) { case ADD_RANGE: if (locked) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Flag '!' not permitted on lines of type 'r'."); if (resolved_name) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'r' don't take a name field."); if (!resolved_id) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'r' require an ID range in the third field."); if (description || home || shell) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type '%c' don't take a %s field.", action[0], description ? "GECOS" : home ? "home directory" : "login shell"); r = uid_range_add_str(&c->uid_range, resolved_id); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Invalid UID range %s.", resolved_id); return 0; case ADD_MEMBER: { /* Try to extend an existing member or group item */ if (!name) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'm' require a user name in the second field."); if (locked) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Flag '!' not permitted on lines of type 'm'."); if (!resolved_id) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'm' require a group name in the third field."); if (!valid_user_group_name(resolved_id, 0)) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "'%s' is not a valid user or group name.", resolved_id); if (description || home || shell) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type '%c' don't take a %s field.", action[0], description ? "GECOS" : home ? "home directory" : "login shell"); r = string_strv_ordered_hashmap_put(&c->members, resolved_id, resolved_name); if (r < 0) return log_error_errno(r, "Failed to store mapping for %s: %m", resolved_id); return 0; } case ADD_USER: if (!name) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'u' require a user name in the second field."); r = ordered_hashmap_ensure_allocated(&c->users, &item_hash_ops); if (r < 0) return log_oom(); i = item_new(ADD_USER, resolved_name, fname, line); if (!i) return log_oom(); if (resolved_id) { if (path_is_absolute(resolved_id)) i->uid_path = path_simplify(TAKE_PTR(resolved_id)); else { _cleanup_free_ char *uid = NULL, *gid = NULL; if (split_pair(resolved_id, ":", &uid, &gid) == 0) { r = parse_gid(gid, &i->gid); if (r < 0) { if (valid_user_group_name(gid, 0)) i->group_name = TAKE_PTR(gid); else return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to parse GID: '%s': %m", id); } else { i->gid_set = true; i->id_set_strict = true; } free_and_replace(resolved_id, uid); } if (!streq(resolved_id, "-")) { r = parse_uid(resolved_id, &i->uid); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to parse UID: '%s': %m", id); i->uid_set = true; } } } i->description = TAKE_PTR(resolved_description); i->home = TAKE_PTR(resolved_home); i->shell = TAKE_PTR(resolved_shell); i->locked = locked; h = c->users; break; case ADD_GROUP: if (!name) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type 'g' require a user name in the second field."); if (locked) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Flag '!' not permitted on lines of type 'g'."); if (description || home || shell) return log_syntax(NULL, LOG_ERR, fname, line, SYNTHETIC_ERRNO(EINVAL), "Lines of type '%c' don't take a %s field.", action[0], description ? "GECOS" : home ? "home directory" : "login shell"); r = ordered_hashmap_ensure_allocated(&c->groups, &item_hash_ops); if (r < 0) return log_oom(); i = item_new(ADD_GROUP, resolved_name, fname, line); if (!i) return log_oom(); if (resolved_id) { if (path_is_absolute(resolved_id)) i->gid_path = path_simplify(TAKE_PTR(resolved_id)); else { r = parse_gid(resolved_id, &i->gid); if (r < 0) return log_syntax(NULL, LOG_ERR, fname, line, r, "Failed to parse GID: '%s': %m", id); i->gid_set = true; } } h = c->groups; break; default: assert_not_reached(); } existing = ordered_hashmap_get(h, i->name); if (existing) { /* Two functionally-equivalent items are fine */ r = item_equivalent(i, existing); if (r < 0) return r; if (r == 0) { if (existing->filename) log_syntax(NULL, LOG_WARNING, fname, line, 0, "Conflict with earlier configuration for %s '%s' in %s:%u, ignoring line.", item_type_to_string(i->type), i->name, existing->filename, existing->line); else log_syntax(NULL, LOG_WARNING, fname, line, 0, "Conflict with earlier configuration for %s '%s', ignoring line.", item_type_to_string(i->type), i->name); } return 0; } r = ordered_hashmap_put(h, i->name, i); if (r < 0) return log_oom(); i = NULL; return 0; } static int read_config_file(Context *c, const char *fn, bool ignore_enoent) { return conf_file_read( arg_root, (const char**) CONF_PATHS_STRV("sysusers.d"), ASSERT_PTR(fn), parse_line, ASSERT_PTR(c), ignore_enoent, /* invalid_config= */ NULL); } static int cat_config(void) { _cleanup_strv_free_ char **files = NULL; int r; r = conf_files_list_with_replacement(arg_root, CONF_PATHS_STRV("sysusers.d"), arg_replace, &files, NULL); if (r < 0) return r; pager_open(arg_pager_flags); return cat_files(NULL, files, arg_cat_flags); } static int help(void) { _cleanup_free_ char *link = NULL; _cleanup_(table_unrefp) Table *cmds = NULL, *opts = NULL; int r; r = terminal_urlify_man("systemd-sysusers.service", "8", &link); if (r < 0) return log_oom(); r = option_parser_get_help_table(&cmds); if (r < 0) return r; r = option_parser_get_help_table_group("Options", &opts); if (r < 0) return r; (void) table_sync_column_widths(0, cmds, opts); printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n" "\n%sCreates system user and group accounts.%s\n" "\nCommands:\n", program_invocation_short_name, ansi_highlight(), ansi_normal()); r = table_print_or_warn(cmds); if (r < 0) return r; printf("\nOptions:\n"); r = table_print_or_warn(opts); if (r < 0) return r; printf("\nSee the %s for details.\n", link); return 0; } static int parse_argv(int argc, char *argv[], char ***ret_args) { int r; assert(argc >= 0); assert(argv); OptionParser opts = { argc, argv }; FOREACH_OPTION_OR_RETURN(c, &opts) switch (c) { OPTION_COMMON_CAT_CONFIG: arg_cat_flags = CAT_CONFIG_ON; break; OPTION_COMMON_TLDR: arg_cat_flags = CAT_TLDR; break; OPTION_COMMON_HELP: return help(); OPTION_COMMON_VERSION: return version(); OPTION_GROUP("Options"): {} OPTION_LONG("root", "PATH", "Operate on an alternate filesystem root"): r = parse_path_argument(opts.arg, /* suppress_root= */ false, &arg_root); if (r < 0) return r; break; OPTION_LONG("image", "PATH", "Operate on disk image as filesystem root"): r = parse_path_argument(opts.arg, /* suppress_root= */ false, &arg_image); if (r < 0) return r; break; OPTION_LONG("image-policy", "POLICY", "Specify disk image dissection policy"): r = parse_image_policy_argument(opts.arg, &arg_image_policy); if (r < 0) return r; break; OPTION_LONG("replace", "PATH", "Treat arguments as replacement for PATH"): if (!path_is_absolute(opts.arg)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "The argument to --replace= must be an absolute path."); if (!endswith(opts.arg, ".conf")) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "The argument to --replace= must have the extension '.conf'."); arg_replace = opts.arg; break; OPTION('n', "dry-run", NULL, "Just print what would be done"): arg_dry_run = true; break; OPTION_LONG("inline", NULL, "Treat arguments as configuration lines"): arg_inline = true; break; OPTION_COMMON_NO_PAGER: arg_pager_flags |= PAGER_DISABLE; break; } char **args = option_parser_get_args(&opts); size_t n_args = option_parser_get_n_args(&opts); if (arg_replace && arg_cat_flags != CAT_CONFIG_OFF) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Option --replace= is not supported with --cat-config/--tldr."); if (arg_inline && arg_cat_flags != CAT_CONFIG_OFF) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Option --inline is not supported with --cat-config/--tldr."); if (arg_replace && n_args == 0) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "When --replace= is given, some configuration items must be specified."); if (arg_image && arg_root) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Use either --root= or --image=, the combination of both is not supported."); *ret_args = args; return 1; } static int parse_arguments(Context *c, char **args) { unsigned pos = 1; int r; assert(c); STRV_FOREACH(arg, args) { if (arg_inline) /* Use (argument):n, where n==1 for the first positional arg */ r = parse_line("(argument)", pos, *arg, /* invalid_config= */ NULL, c); else r = read_config_file(c, *arg, /* ignore_enoent= */ false); if (r < 0) return r; pos++; } return 0; } static int read_config_files(Context *c, char **args) { _cleanup_strv_free_ char **files = NULL; _cleanup_free_ char *p = NULL; int r; assert(c); r = conf_files_list_with_replacement(arg_root, CONF_PATHS_STRV("sysusers.d"), arg_replace, &files, &p); if (r < 0) return r; STRV_FOREACH(f, files) if (p && path_equal(*f, p)) { log_debug("Parsing arguments at position \"%s\"%s", *f, glyph(GLYPH_ELLIPSIS)); r = parse_arguments(c, args); if (r < 0) return r; } else { log_debug("Reading config file \"%s\"%s", *f, glyph(GLYPH_ELLIPSIS)); /* Just warn, ignore result otherwise */ (void) read_config_file(c, *f, /* ignore_enoent= */ true); } return 0; } static int read_credential_lines(Context *c) { _cleanup_free_ char *j = NULL; const char *d; int r; assert(c); r = get_credentials_dir(&d); if (r == -ENXIO) return 0; if (r < 0) return log_error_errno(r, "Failed to get credentials directory: %m"); j = path_join(d, "sysusers.extra"); if (!j) return log_oom(); (void) read_config_file(c, j, /* ignore_enoent= */ true); return 0; } static int run(int argc, char *argv[]) { _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL; _cleanup_(umount_and_freep) char *mounted_dir = NULL; _cleanup_close_ int lock = -EBADF; _cleanup_(context_done) Context c = { .audit_fd = -EBADF, .search_uid = UID_INVALID, }; Item *i; int r; LIBAUDIT_NOTE(recommended); LIBBLKID_NOTE(recommended); LIBCRYPT_NOTE(recommended); LIBCRYPTSETUP_NOTE(suggested); LIBCRYPTO_NOTE(suggested); LIBMOUNT_NOTE(recommended); LIBSELINUX_NOTE(recommended); char **args = NULL; r = parse_argv(argc, argv, &args); if (r <= 0) return r; log_setup(); if (arg_cat_flags != CAT_CONFIG_OFF) return cat_config(); if (should_bypass("SYSTEMD_SYSUSERS")) return 0; umask(0022); r = mac_init(); if (r < 0) return r; if (arg_image) { assert(!arg_root); r = mount_image_privately_interactively( arg_image, arg_image_policy, DISSECT_IMAGE_GENERIC_ROOT | DISSECT_IMAGE_REQUIRE_ROOT | DISSECT_IMAGE_VALIDATE_OS | DISSECT_IMAGE_RELAX_VAR_CHECK | DISSECT_IMAGE_FSCK | DISSECT_IMAGE_GROWFS | DISSECT_IMAGE_ALLOW_USERSPACE_VERITY, &mounted_dir, /* ret_dir_fd= */ NULL, &loop_device); if (r < 0) return r; arg_root = strdup(mounted_dir); if (!arg_root) return log_oom(); } r = mac_label_context_new(arg_root, &c.label_context); if (r < 0) return log_error_errno(r, "Failed to initialize label context for root '%s': %m", arg_root); /* Prepare to emit audit events, but only if we're operating on the host system. */ if (!arg_root) c.audit_fd = open_audit_fd_or_warn(); /* If command line arguments are specified along with --replace, read all configuration files and * insert the positional arguments at the specified place. Otherwise, if command line arguments are * specified, execute just them, and finally, without --replace= or any positional arguments, just * read configuration and execute it. */ if (arg_replace || strv_isempty(args)) r = read_config_files(&c, args); else r = parse_arguments(&c, args); if (r < 0) return r; r = read_credential_lines(&c); if (r < 0) return r; /* Let's tell nss-systemd not to synthesize the "root" and "nobody" entries for it, so that our * detection whether the names or UID/GID area already used otherwise doesn't get confused. After * all, even though nss-systemd synthesizes these users/groups, they should still appear in * /etc/passwd and /etc/group, as the synthesizing logic is merely supposed to be fallback for cases * where we run with a completely unpopulated /etc. */ if (setenv("SYSTEMD_NSS_BYPASS_SYNTHETIC", "1", 1) < 0) return log_error_errno(errno, "Failed to set SYSTEMD_NSS_BYPASS_SYNTHETIC environment variable: %m"); if (!c.uid_range) { /* Default to default range of SYSTEMD_UID_MIN..SYSTEM_UID_MAX. */ r = read_login_defs(&c.login_defs, NULL, arg_root); if (r < 0) return log_error_errno(r, "Failed to read %s%s: %m", strempty(arg_root), "/etc/login.defs"); c.login_defs_need_warning = true; /* We pick a range that very conservative: we look at compiled-in maximum and the value in * /etc/login.defs. That way the UIDs/GIDs which we allocate will be interpreted correctly, * even if /etc/login.defs is removed later. (The bottom bound doesn't matter much, since * it's only used during allocation, so we use the configured value directly). */ uid_t begin = c.login_defs.system_alloc_uid_min, end = MIN3((uid_t) SYSTEM_UID_MAX, c.login_defs.system_uid_max, c.login_defs.system_gid_max); if (begin < end) { r = uid_range_add(&c.uid_range, begin, end - begin + 1); if (r < 0) return log_oom(); } } r = add_implicit(&c); if (r < 0) return r; if (!arg_dry_run) { lock = take_etc_passwd_lock(arg_root); if (lock < 0) return log_error_errno(lock, "Failed to take /etc/passwd lock: %m"); } r = load_user_database(&c); if (r < 0) return log_error_errno(r, "Failed to load user database: %m"); r = load_group_database(&c); if (r < 0) return log_error_errno(r, "Failed to read group database: %m"); ORDERED_HASHMAP_FOREACH(i, c.groups) (void) process_item(&c, i); ORDERED_HASHMAP_FOREACH(i, c.users) (void) process_item(&c, i); return write_files(&c); } DEFINE_MAIN_FUNCTION(run);