/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include "alloc-util.h" #include "conf-files.h" #include "copy.h" #include "def.h" #include "fd-util.h" #include "fileio.h" #include "format-util.h" #include "fs-util.h" #include "hashmap.h" #include "main-func.h" #include "pager.h" #include "path-util.h" #include "pretty-print.h" #include "set.h" #include "selinux-util.h" #include "smack-util.h" #include "specifier.h" #include "string-util.h" #include "strv.h" #include "tmpfile-util-label.h" #include "uid-range.h" #include "user-util.h" #include "utf8.h" #include "util.h" typedef enum ItemType { ADD_USER = 'u', ADD_GROUP = 'g', ADD_MEMBER = 'm', ADD_RANGE = 'r', } ItemType; typedef struct Item { ItemType type; char *name; char *uid_path; char *gid_path; char *description; char *home; char *shell; gid_t gid; uid_t uid; bool gid_set:1; /* 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:1; bool uid_set:1; bool todo_user:1; bool todo_group:1; } Item; static char *arg_root = NULL; static bool arg_cat_config = false; static const char *arg_replace = NULL; static bool arg_inline = false; static PagerFlags arg_pager_flags = 0; static OrderedHashmap *users = NULL, *groups = NULL; static OrderedHashmap *todo_uids = NULL, *todo_gids = NULL; static OrderedHashmap *members = NULL; static Hashmap *database_by_uid = NULL, *database_by_username = NULL; static Hashmap *database_by_gid = NULL, *database_by_groupname = NULL; static Set *database_users = NULL, *database_groups = NULL; static uid_t search_uid = UID_INVALID; static UidRange *uid_range = NULL; static unsigned n_uid_range = 0; STATIC_DESTRUCTOR_REGISTER(groups, ordered_hashmap_freep); STATIC_DESTRUCTOR_REGISTER(users, ordered_hashmap_freep); STATIC_DESTRUCTOR_REGISTER(members, ordered_hashmap_freep); STATIC_DESTRUCTOR_REGISTER(todo_uids, ordered_hashmap_freep); STATIC_DESTRUCTOR_REGISTER(todo_gids, ordered_hashmap_freep); STATIC_DESTRUCTOR_REGISTER(database_by_uid, hashmap_freep); STATIC_DESTRUCTOR_REGISTER(database_by_username, hashmap_freep); STATIC_DESTRUCTOR_REGISTER(database_users, set_free_freep); STATIC_DESTRUCTOR_REGISTER(database_by_gid, hashmap_freep); STATIC_DESTRUCTOR_REGISTER(database_by_groupname, hashmap_freep); STATIC_DESTRUCTOR_REGISTER(database_groups, set_free_freep); STATIC_DESTRUCTOR_REGISTER(uid_range, freep); STATIC_DESTRUCTOR_REGISTER(arg_root, freep); static int load_user_database(void) { _cleanup_fclose_ FILE *f = NULL; const char *passwd_path; struct passwd *pw; int r; passwd_path = prefix_roota(arg_root, "/etc/passwd"); f = fopen(passwd_path, "re"); if (!f) return errno == ENOENT ? 0 : -errno; r = hashmap_ensure_allocated(&database_by_username, &string_hash_ops); if (r < 0) return r; r = hashmap_ensure_allocated(&database_by_uid, NULL); if (r < 0) return r; r = set_ensure_allocated(&database_users, NULL); if (r < 0) return r; while ((r = fgetpwent_sane(f, &pw)) > 0) { char *n; int k, q; n = strdup(pw->pw_name); if (!n) return -ENOMEM; k = set_put(database_users, n); if (k < 0) { free(n); return k; } k = hashmap_put(database_by_username, n, UID_TO_PTR(pw->pw_uid)); if (k < 0 && k != -EEXIST) return k; q = hashmap_put(database_by_uid, UID_TO_PTR(pw->pw_uid), n); if (q < 0 && q != -EEXIST) return q; } return r; } static int load_group_database(void) { _cleanup_fclose_ FILE *f = NULL; const char *group_path; struct group *gr; int r; group_path = prefix_roota(arg_root, "/etc/group"); f = fopen(group_path, "re"); if (!f) return errno == ENOENT ? 0 : -errno; r = hashmap_ensure_allocated(&database_by_groupname, &string_hash_ops); if (r < 0) return r; r = hashmap_ensure_allocated(&database_by_gid, NULL); if (r < 0) return r; r = set_ensure_allocated(&database_groups, NULL); if (r < 0) return r; while ((r = fgetgrent_sane(f, &gr)) > 0) { char *n; int k, q; n = strdup(gr->gr_name); if (!n) return -ENOMEM; k = set_put(database_groups, n); if (k < 0) { free(n); return k; } k = hashmap_put(database_by_groupname, n, GID_TO_PTR(gr->gr_gid)); if (k < 0 && k != -EEXIST) return k; q = hashmap_put(database_by_gid, GID_TO_PTR(gr->gr_gid), n); if (q < 0 && q != -EEXIST) return q; } return r; } static int make_backup(const char *target, const char *x) { _cleanup_close_ int src = -1; _cleanup_fclose_ FILE *dst = NULL; _cleanup_free_ char *temp = NULL; char *backup; struct timespec ts[2]; struct stat st; int r; 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_label(target, x, &dst, &temp); if (r < 0) return r; r = copy_bytes(src, fileno(dst), (uint64_t) -1, COPY_REFLINK); if (r < 0) goto fail; /* Don't fail on chmod() or chown(). If it stays owned by us * and/or unreadable by others, then it isn't too bad... */ backup = strjoina(x, "-"); /* Copy over the access mask */ r = fchmod_and_chown(fileno(dst), 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); ts[0] = st.st_atim; ts[1] = st.st_mtim; if (futimens(fileno(dst), ts) < 0) log_warning_errno(errno, "Failed to fix access and modification time of %s: %m", backup); r = fflush_sync_and_check(dst); if (r < 0) goto fail; if (rename(temp, backup) < 0) { r = -errno; goto fail; } return 0; fail: (void) unlink(temp); return r; } static int putgrent_with_members(const struct group *gr, FILE *group) { char **a; assert(gr); assert(group); a = ordered_hashmap_get(members, gr->gr_name); if (a) { _cleanup_strv_free_ char **l = NULL; bool added = false; char **i; l = strv_copy(gr->gr_mem); if (!l) return -ENOMEM; STRV_FOREACH(i, a) { if (strv_find(l, *i)) continue; if (strv_extend(&l, *i) < 0) return -ENOMEM; added = true; } if (added) { struct group t; int r; strv_uniq(l); strv_sort(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(const struct sgrp *sg, FILE *gshadow) { char **a; assert(sg); assert(gshadow); a = ordered_hashmap_get(members, sg->sg_namp); if (a) { _cleanup_strv_free_ char **l = NULL; bool added = false; char **i; l = strv_copy(sg->sg_mem); if (!l) return -ENOMEM; STRV_FOREACH(i, a) { if (strv_find(l, *i)) continue; if (strv_extend(&l, *i) < 0) return -ENOMEM; added = true; } if (added) { struct sgrp t; int r; strv_uniq(l); strv_sort(l); t = *sg; t.sg_mem = l; r = putsgent_sane(&t, gshadow); return r < 0 ? r : 1; } } return putsgent_sane(sg, gshadow); } #endif static int sync_rights(FILE *from, FILE *to) { struct stat st; if (fstat(fileno(from), &st) < 0) return -errno; return fchmod_and_chown(fileno(to), st.st_mode & 07777, st.st_uid, st.st_gid); } static int rename_and_apply_smack(const char *temp_path, const char *dest_path) { int r = 0; if (rename(temp_path, dest_path) < 0) return -errno; #ifdef SMACK_RUN_LABEL r = mac_smack_apply(dest_path, SMACK_ATTR_ACCESS, SMACK_FLOOR_LABEL); if (r < 0) return r; #endif return r; } static const char* default_shell(uid_t uid) { return uid == 0 ? "/bin/sh" : "/sbin/nologin"; } static int write_temporary_passwd(const char *passwd_path, FILE **tmpfile, char **tmpfile_path) { _cleanup_fclose_ FILE *original = NULL, *passwd = NULL; _cleanup_(unlink_and_freep) char *passwd_tmp = NULL; struct passwd *pw = NULL; Iterator iterator; Item *i; int r; if (ordered_hashmap_size(todo_uids) == 0) return 0; r = fopen_temporary_label("/etc/passwd", passwd_path, &passwd, &passwd_tmp); if (r < 0) return r; original = fopen(passwd_path, "re"); if (original) { r = sync_rights(original, passwd); if (r < 0) return r; while ((r = fgetpwent_sane(original, &pw)) > 0) { i = ordered_hashmap_get(users, pw->pw_name); if (i && i->todo_user) { log_error("%s: User \"%s\" already exists.", passwd_path, pw->pw_name); return -EEXIST; } if (ordered_hashmap_contains(todo_uids, UID_TO_PTR(pw->pw_uid))) { log_error("%s: Detected collision for UID " UID_FMT ".", passwd_path, pw->pw_uid); return -EEXIST; } /* 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 r; } if (r < 0) return r; } else { if (errno != ENOENT) return -errno; if (fchmod(fileno(passwd), 0644) < 0) return -errno; } ORDERED_HASHMAP_FOREACH(i, todo_uids, iterator) { struct passwd n = { .pw_name = i->name, .pw_uid = i->uid, .pw_gid = i->gid, .pw_gecos = i->description, /* "x" means the password is stored in the shadow file */ .pw_passwd = (char*) "x", /* We default to the root directory as home */ .pw_dir = i->home ? i->home : (char*) "/", /* Initialize the shell to nologin, with one exception: * for root we patch in something special */ .pw_shell = i->shell ?: (char*) default_shell(i->uid), }; r = putpwent_sane(&n, passwd); if (r < 0) return r; } /* Append the remaining NIS entries if any */ while (pw) { r = putpwent_sane(pw, passwd); if (r < 0) return r; r = fgetpwent_sane(original, &pw); if (r < 0) return r; if (r == 0) break; } r = fflush_and_check(passwd); if (r < 0) return r; *tmpfile = TAKE_PTR(passwd); *tmpfile_path = TAKE_PTR(passwd_tmp); return 0; } static int write_temporary_shadow(const char *shadow_path, FILE **tmpfile, char **tmpfile_path) { _cleanup_fclose_ FILE *original = NULL, *shadow = NULL; _cleanup_(unlink_and_freep) char *shadow_tmp = NULL; struct spwd *sp = NULL; Iterator iterator; long lstchg; Item *i; int r; if (ordered_hashmap_size(todo_uids) == 0) return 0; r = fopen_temporary_label("/etc/shadow", shadow_path, &shadow, &shadow_tmp); if (r < 0) return r; lstchg = (long) (now(CLOCK_REALTIME) / USEC_PER_DAY); original = fopen(shadow_path, "re"); if (original) { r = sync_rights(original, shadow); if (r < 0) return r; while ((r = fgetspent_sane(original, &sp)) > 0) { i = ordered_hashmap_get(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(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 r; } if (r < 0) return r; } else { if (errno != ENOENT) return -errno; if (fchmod(fileno(shadow), 0000) < 0) return -errno; } ORDERED_HASHMAP_FOREACH(i, todo_uids, iterator) { struct spwd n = { .sp_namp = i->name, .sp_pwdp = (char*) "!!", .sp_lstchg = lstchg, .sp_min = -1, .sp_max = -1, .sp_warn = -1, .sp_inact = -1, .sp_expire = -1, .sp_flag = (unsigned long) -1, /* this appears to be what everybody does ... */ }; r = putspent_sane(&n, shadow); if (r < 0) return r; } /* Append the remaining NIS entries if any */ while (sp) { r = putspent_sane(sp, shadow); if (r < 0) return r; r = fgetspent_sane(original, &sp); if (r < 0) return r; if (r == 0) break; } if (!IN_SET(errno, 0, ENOENT)) return -errno; r = fflush_sync_and_check(shadow); if (r < 0) return r; *tmpfile = TAKE_PTR(shadow); *tmpfile_path = TAKE_PTR(shadow_tmp); return 0; } static int write_temporary_group(const char *group_path, FILE **tmpfile, char **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; Iterator iterator; Item *i; int r; if (ordered_hashmap_size(todo_gids) == 0 && ordered_hashmap_size(members) == 0) return 0; r = fopen_temporary_label("/etc/group", group_path, &group, &group_tmp); if (r < 0) return r; original = fopen(group_path, "re"); if (original) { r = sync_rights(original, group); if (r < 0) return r; 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(groups, gr->gr_name); if (i && i->todo_group) { log_error("%s: Group \"%s\" already exists.", group_path, gr->gr_name); return -EEXIST; } if (ordered_hashmap_contains(todo_gids, GID_TO_PTR(gr->gr_gid))) { log_error("%s: Detected collision for GID " GID_FMT ".", group_path, gr->gr_gid); return -EEXIST; } /* Make sure we keep the NIS entries (if any) at the end. */ if (IN_SET(gr->gr_name[0], '+', '-')) break; r = putgrent_with_members(gr, group); if (r < 0) return r; if (r > 0) group_changed = true; } if (r < 0) return r; } else { if (errno != ENOENT) return -errno; if (fchmod(fileno(group), 0644) < 0) return -errno; } ORDERED_HASHMAP_FOREACH(i, todo_gids, iterator) { struct group n = { .gr_name = i->name, .gr_gid = i->gid, .gr_passwd = (char*) "x", }; r = putgrent_with_members(&n, group); if (r < 0) return r; group_changed = true; } /* Append the remaining NIS entries if any */ while (gr) { r = putgrent_sane(gr, group); if (r < 0) return r; r = fgetgrent_sane(original, &gr); if (r < 0) return r; if (r == 0) break; } r = fflush_sync_and_check(group); if (r < 0) return r; if (group_changed) { *tmpfile = TAKE_PTR(group); *tmpfile_path = TAKE_PTR(group_tmp); } return 0; } static int write_temporary_gshadow(const char * gshadow_path, FILE **tmpfile, char **tmpfile_path) { #if ENABLE_GSHADOW _cleanup_fclose_ FILE *original = NULL, *gshadow = NULL; _cleanup_(unlink_and_freep) char *gshadow_tmp = NULL; bool group_changed = false; Iterator iterator; Item *i; int r; if (ordered_hashmap_size(todo_gids) == 0 && ordered_hashmap_size(members) == 0) return 0; r = fopen_temporary_label("/etc/gshadow", gshadow_path, &gshadow, &gshadow_tmp); if (r < 0) return r; original = fopen(gshadow_path, "re"); if (original) { struct sgrp *sg; r = sync_rights(original, gshadow); if (r < 0) return r; while ((r = fgetsgent_sane(original, &sg)) > 0) { i = ordered_hashmap_get(groups, sg->sg_namp); if (i && i->todo_group) { log_error("%s: Group \"%s\" already exists.", gshadow_path, sg->sg_namp); return -EEXIST; } r = putsgent_with_members(sg, gshadow); if (r < 0) return r; if (r > 0) group_changed = true; } if (r < 0) return r; } else { if (errno != ENOENT) return -errno; if (fchmod(fileno(gshadow), 0000) < 0) return -errno; } ORDERED_HASHMAP_FOREACH(i, todo_gids, iterator) { struct sgrp n = { .sg_namp = i->name, .sg_passwd = (char*) "!!", }; r = putsgent_with_members(&n, gshadow); if (r < 0) return r; group_changed = true; } r = fflush_sync_and_check(gshadow); if (r < 0) return r; if (group_changed) { *tmpfile = TAKE_PTR(gshadow); *tmpfile_path = TAKE_PTR(gshadow_tmp); } return 0; #else return 0; #endif } static int write_files(void) { _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; const char *passwd_path = NULL, *group_path = NULL, *shadow_path = NULL, *gshadow_path = NULL; int r; passwd_path = prefix_roota(arg_root, "/etc/passwd"); shadow_path = prefix_roota(arg_root, "/etc/shadow"); group_path = prefix_roota(arg_root, "/etc/group"); gshadow_path = prefix_roota(arg_root, "/etc/gshadow"); r = write_temporary_group(group_path, &group, &group_tmp); if (r < 0) return r; r = write_temporary_gshadow(gshadow_path, &gshadow, &gshadow_tmp); if (r < 0) return r; r = write_temporary_passwd(passwd_path, &passwd, &passwd_tmp); if (r < 0) return r; r = write_temporary_shadow(shadow_path, &shadow, &shadow_tmp); if (r < 0) return r; /* Make a backup of the old files */ if (group) { r = make_backup("/etc/group", group_path); if (r < 0) return r; } if (gshadow) { r = make_backup("/etc/gshadow", gshadow_path); if (r < 0) return r; } if (passwd) { r = make_backup("/etc/passwd", passwd_path); if (r < 0) return r; } if (shadow) { r = make_backup("/etc/shadow", shadow_path); if (r < 0) return r; } /* And make the new files count */ if (group) { r = rename_and_apply_smack(group_tmp, group_path); if (r < 0) return r; group_tmp = mfree(group_tmp); } if (gshadow) { r = rename_and_apply_smack(gshadow_tmp, gshadow_path); if (r < 0) return r; gshadow_tmp = mfree(gshadow_tmp); } if (passwd) { r = rename_and_apply_smack(passwd_tmp, passwd_path); if (r < 0) return r; passwd_tmp = mfree(passwd_tmp); } if (shadow) { r = rename_and_apply_smack(shadow_tmp, shadow_path); if (r < 0) return r; shadow_tmp = mfree(shadow_tmp); } return 0; } static int uid_is_ok(uid_t uid, const char *name, bool check_with_gid) { struct passwd *p; struct group *g; const char *n; Item *i; /* Let's see if we already have assigned the UID a second time */ if (ordered_hashmap_get(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) { i = ordered_hashmap_get(todo_gids, GID_TO_PTR(uid)); if (i && !streq(i->name, name)) return 0; } /* Let's check the files directly */ if (hashmap_contains(database_by_uid, UID_TO_PTR(uid))) return 0; if (check_with_gid) { n = hashmap_get(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) { errno = 0; p = getpwuid(uid); if (p) return 0; if (!IN_SET(errno, 0, ENOENT)) return -errno; if (check_with_gid) { errno = 0; g = getgrgid((gid_t) uid); if (g) { if (!streq(g->gr_name, name)) return 0; } else if (!IN_SET(errno, 0, ENOENT)) return -errno; } } return 1; } static int root_stat(const char *p, struct stat *st) { const char *fix; fix = prefix_roota(arg_root, p); if (stat(fix, st) < 0) return -errno; return 0; } static int read_id_from_file(Item *i, uid_t *_uid, gid_t *_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 (_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 ((_uid || (_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 (_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 (_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 (_uid) { if (!found_uid) return 0; *_uid = uid; } if (_gid) { if (!found_gid) return 0; *_gid = gid; } return 1; } static int add_user(Item *i) { void *z; int r; assert(i); /* Check the database directly */ z = hashmap_get(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) { struct passwd *p; /* Also check NSS */ errno = 0; p = getpwnam(i->name); if (p) { 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 (!IN_SET(errno, 0, ENOENT)) return log_error_errno(errno, "Failed to check if user %s already exists: %m", i->name); } /* Try to use the suggested numeric uid */ if (i->uid_set) { r = uid_is_ok(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_debug("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 c; if (read_id_from_file(i, &c, NULL) > 0) { if (c <= 0 || !uid_range_contains(uid_range, n_uid_range, c)) log_debug("User ID " UID_FMT " of file not suitable for %s.", c, i->name); else { r = uid_is_ok(c, 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 = c; i->uid_set = true; } else log_debug("User ID " UID_FMT " of file for %s is already used.", c, i->name); } } } /* Otherwise, try to reuse the group ID */ if (!i->uid_set && i->gid_set) { r = uid_is_ok((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) { for (;;) { r = uid_range_next_lower(uid_range, n_uid_range, &search_uid); if (r < 0) { log_error("No free user ID available for %s.", i->name); return r; } r = uid_is_ok(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 = search_uid; } r = ordered_hashmap_ensure_allocated(&todo_uids, NULL); if (r < 0) return log_oom(); r = ordered_hashmap_put(todo_uids, UID_TO_PTR(i->uid), i); if (r < 0) return log_oom(); 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(gid_t gid) { struct group *g; struct passwd *p; if (ordered_hashmap_get(todo_gids, GID_TO_PTR(gid))) return 0; /* Avoid reusing gids that are already used by a different user */ if (ordered_hashmap_get(todo_uids, UID_TO_PTR(gid))) return 0; if (hashmap_contains(database_by_gid, GID_TO_PTR(gid))) return 0; if (hashmap_contains(database_by_uid, UID_TO_PTR(gid))) return 0; if (!arg_root) { errno = 0; g = getgrgid(gid); if (g) return 0; if (!IN_SET(errno, 0, ENOENT)) return -errno; errno = 0; p = getpwuid((uid_t) gid); if (p) return 0; if (!IN_SET(errno, 0, ENOENT)) return -errno; } return 1; } static int add_group(Item *i) { void *z; int r; assert(i); /* Check the database directly */ z = hashmap_get(database_by_groupname, i->name); if (z) { log_debug("Group %s already exists.", i->name); i->gid = PTR_TO_GID(z); i->gid_set = true; return 0; } /* Also check NSS */ if (!arg_root) { struct group *g; errno = 0; g = getgrnam(i->name); if (g) { log_debug("Group %s already exists.", i->name); i->gid = g->gr_gid; i->gid_set = true; return 0; } if (!IN_SET(errno, 0, ENOENT)) return log_error_errno(errno, "Failed to check if group %s already exists: %m", i->name); } /* Try to use the suggested numeric gid */ if (i->gid_set) { r = gid_is_ok(i->gid); 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 %d", i->name, i->gid); if (r == 0) return 0; } if (r == 0) { log_debug("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((gid_t) i->uid); 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 c; if (read_id_from_file(i, NULL, &c) > 0) { if (c <= 0 || !uid_range_contains(uid_range, n_uid_range, c)) log_debug("Group ID " GID_FMT " of file not suitable for %s.", c, i->name); else { r = gid_is_ok(c); if (r < 0) return log_error_errno(r, "Failed to verify gid " GID_FMT ": %m", i->gid); else if (r > 0) { i->gid = c; i->gid_set = true; } else log_debug("Group ID " GID_FMT " of file for %s already used.", c, i->name); } } } /* And if that didn't work either, let's try to find a free one */ if (!i->gid_set) { for (;;) { /* We look for new GIDs in the UID pool! */ r = uid_range_next_lower(uid_range, n_uid_range, &search_uid); if (r < 0) { log_error("No free group ID available for %s.", i->name); return r; } r = gid_is_ok(search_uid); 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 = search_uid; } r = ordered_hashmap_ensure_allocated(&todo_gids, NULL); if (r < 0) return log_oom(); r = ordered_hashmap_put(todo_gids, GID_TO_PTR(i->gid), i); if (r < 0) return log_oom(); i->todo_group = true; log_info("Creating group %s with gid " GID_FMT ".", i->name, i->gid); return 0; } static int process_item(Item *i) { int r; assert(i); switch (i->type) { case ADD_USER: { Item *j; j = ordered_hashmap_get(groups, i->name); if (j && j->todo_group) { /* When the group with the same 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 { r = add_group(i); if (r < 0) return r; } return add_user(i); } case ADD_GROUP: return add_group(i); default: assert_not_reached("Unknown item type"); } } static Item* item_free(Item *i) { if (!i) return NULL; free(i->name); free(i->uid_path); free(i->gid_path); free(i->description); free(i->home); free(i->shell); 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 int add_implicit(void) { char *g, **l; Iterator iterator; int r; /* Implicitly create additional users and groups, if they were listed in "m" lines */ ORDERED_HASHMAP_FOREACH_KEY(l, g, members, iterator) { char **m; STRV_FOREACH(m, l) if (!ordered_hashmap_get(users, *m)) { _cleanup_(item_freep) Item *j = NULL; r = ordered_hashmap_ensure_allocated(&users, &item_hash_ops); if (r < 0) return log_oom(); j = new0(Item, 1); if (!j) return log_oom(); j->type = ADD_USER; j->name = strdup(*m); if (!j->name) return log_oom(); r = ordered_hashmap_put(users, j->name, j); if (r < 0) return log_oom(); log_debug("Adding implicit user '%s' due to m line", j->name); j = NULL; } if (!(ordered_hashmap_get(users, g) || ordered_hashmap_get(groups, g))) { _cleanup_(item_freep) Item *j = NULL; r = ordered_hashmap_ensure_allocated(&groups, &item_hash_ops); if (r < 0) return log_oom(); j = new0(Item, 1); if (!j) return log_oom(); j->type = ADD_GROUP; j->name = strdup(g); if (!j->name) return log_oom(); r = ordered_hashmap_put(groups, j->name, j); if (r < 0) return log_oom(); log_debug("Adding implicit group '%s' due to m line", j->name); j = NULL; } } return 0; } static bool item_equal(Item *a, Item *b) { assert(a); assert(b); if (a->type != b->type) return false; if (!streq_ptr(a->name, b->name)) return false; if (!streq_ptr(a->uid_path, b->uid_path)) return false; if (!streq_ptr(a->gid_path, b->gid_path)) return false; if (!streq_ptr(a->description, b->description)) return false; if (a->uid_set != b->uid_set) return false; if (a->uid_set && a->uid != b->uid) return false; if (a->gid_set != b->gid_set) return false; if (a->gid_set && a->gid != b->gid) return false; if (!streq_ptr(a->home, b->home)) return false; if (!streq_ptr(a->shell, b->shell)) return false; return true; } DEFINE_PRIVATE_HASH_OPS_FULL(members_hash_ops, char, string_hash_func, string_compare_func, free, char*, strv_free); static int parse_line(const char *fname, unsigned line, const char *buffer) { static const Specifier specifier_table[] = { { 'm', specifier_machine_id, NULL }, { 'b', specifier_boot_id, NULL }, { 'H', specifier_host_name, NULL }, { 'v', specifier_kernel_release, NULL }, { 'T', specifier_tmp_dir, NULL }, { 'V', specifier_var_tmp_dir, NULL }, {} }; _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, *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); /* Parse columns */ p = buffer; r = extract_many_words(&p, NULL, EXTRACT_QUOTES, &action, &name, &id, &description, &home, &shell, NULL); if (r < 0) { log_error("[%s:%u] Syntax error.", fname, line); return r; } if (r < 2) { log_error("[%s:%u] Missing action and name columns.", fname, line); return -EINVAL; } if (!isempty(p)) { log_error("[%s:%u] Trailing garbage.", fname, line); return -EINVAL; } /* Verify action */ if (strlen(action) != 1) { log_error("[%s:%u] Unknown modifier '%s'", fname, line, action); return -EINVAL; } if (!IN_SET(action[0], ADD_USER, ADD_GROUP, ADD_MEMBER, ADD_RANGE)) { log_error("[%s:%u] Unknown command type '%c'.", fname, line, action[0]); return -EBADMSG; } /* Verify name */ if (isempty(name) || streq(name, "-")) name = mfree(name); if (name) { r = specifier_printf(name, specifier_table, NULL, &resolved_name); if (r < 0) { log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, name); return r; } if (!valid_user_group_name(resolved_name)) { log_error("[%s:%u] '%s' is not a valid user or group name.", fname, line, resolved_name); return -EINVAL; } } /* Verify id */ if (isempty(id) || streq(id, "-")) id = mfree(id); if (id) { r = specifier_printf(id, specifier_table, NULL, &resolved_id); if (r < 0) { log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, name); return r; } } /* Verify description */ if (isempty(description) || streq(description, "-")) description = mfree(description); if (description) { r = specifier_printf(description, specifier_table, NULL, &resolved_description); if (r < 0) { log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, description); return r; } if (!valid_gecos(resolved_description)) { log_error("[%s:%u] '%s' is not a valid GECOS field.", fname, line, resolved_description); return -EINVAL; } } /* Verify home */ if (isempty(home) || streq(home, "-")) home = mfree(home); if (home) { r = specifier_printf(home, specifier_table, NULL, &resolved_home); if (r < 0) { log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, home); return r; } if (!valid_home(resolved_home)) { log_error("[%s:%u] '%s' is not a valid home directory field.", fname, line, resolved_home); return -EINVAL; } } /* Verify shell */ if (isempty(shell) || streq(shell, "-")) shell = mfree(shell); if (shell) { r = specifier_printf(shell, specifier_table, NULL, &resolved_shell); if (r < 0) { log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, shell); return r; } if (!valid_shell(resolved_shell)) { log_error("[%s:%u] '%s' is not a valid login shell field.", fname, line, resolved_shell); return -EINVAL; } } switch (action[0]) { case ADD_RANGE: if (resolved_name) { log_error("[%s:%u] Lines of type 'r' don't take a name field.", fname, line); return -EINVAL; } if (!resolved_id) { log_error("[%s:%u] Lines of type 'r' require a ID range in the third field.", fname, line); return -EINVAL; } if (description || home || shell) { log_error("[%s:%u] Lines of type '%c' don't take a %s field.", fname, line, action[0], description ? "GECOS" : home ? "home directory" : "login shell"); return -EINVAL; } r = uid_range_add_str(&uid_range, &n_uid_range, resolved_id); if (r < 0) { log_error("[%s:%u] Invalid UID range %s.", fname, line, resolved_id); return -EINVAL; } return 0; case ADD_MEMBER: { char **l; /* Try to extend an existing member or group item */ if (!name) { log_error("[%s:%u] Lines of type 'm' require a user name in the second field.", fname, line); return -EINVAL; } if (!resolved_id) { log_error("[%s:%u] Lines of type 'm' require a group name in the third field.", fname, line); return -EINVAL; } if (!valid_user_group_name(resolved_id)) { log_error("[%s:%u] '%s' is not a valid user or group name.", fname, line, resolved_id); return -EINVAL; } if (description || home || shell) { log_error("[%s:%u] Lines of type '%c' don't take a %s field.", fname, line, action[0], description ? "GECOS" : home ? "home directory" : "login shell"); return -EINVAL; } r = ordered_hashmap_ensure_allocated(&members, &members_hash_ops); if (r < 0) return log_oom(); l = ordered_hashmap_get(members, resolved_id); if (l) { /* A list for this group name already exists, let's append to it */ r = strv_push(&l, resolved_name); if (r < 0) return log_oom(); resolved_name = NULL; assert_se(ordered_hashmap_update(members, resolved_id, l) >= 0); } else { /* No list for this group name exists yet, create one */ l = new0(char *, 2); if (!l) return -ENOMEM; l[0] = resolved_name; l[1] = NULL; r = ordered_hashmap_put(members, resolved_id, l); if (r < 0) { free(l); return log_oom(); } resolved_id = resolved_name = NULL; } return 0; } case ADD_USER: if (!name) { log_error("[%s:%u] Lines of type 'u' require a user name in the second field.", fname, line); return -EINVAL; } r = ordered_hashmap_ensure_allocated(&users, &item_hash_ops); if (r < 0) return log_oom(); i = new0(Item, 1); if (!i) return log_oom(); if (resolved_id) { if (path_is_absolute(resolved_id)) { i->uid_path = TAKE_PTR(resolved_id); path_simplify(i->uid_path, false); } 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) return log_error_errno(r, "Failed to parse GID: '%s': %m", id); 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_error_errno(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); h = users; break; case ADD_GROUP: if (!name) { log_error("[%s:%u] Lines of type 'g' require a user name in the second field.", fname, line); return -EINVAL; } if (description || home || shell) { log_error("[%s:%u] Lines of type '%c' don't take a %s field.", fname, line, action[0], description ? "GECOS" : home ? "home directory" : "login shell"); return -EINVAL; } r = ordered_hashmap_ensure_allocated(&groups, &item_hash_ops); if (r < 0) return log_oom(); i = new0(Item, 1); if (!i) return log_oom(); if (resolved_id) { if (path_is_absolute(resolved_id)) { i->gid_path = TAKE_PTR(resolved_id); path_simplify(i->gid_path, false); } else { r = parse_gid(resolved_id, &i->gid); if (r < 0) return log_error_errno(r, "Failed to parse GID: '%s': %m", id); i->gid_set = true; } } h = groups; break; default: return -EBADMSG; } i->type = action[0]; i->name = TAKE_PTR(resolved_name); existing = ordered_hashmap_get(h, i->name); if (existing) { /* Two identical items are fine */ if (!item_equal(existing, i)) log_warning("Two or more conflicting lines for %s configured, ignoring.", 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(const char *fn, bool ignore_enoent) { _cleanup_fclose_ FILE *rf = NULL; FILE *f = NULL; unsigned v = 0; int r = 0; assert(fn); if (streq(fn, "-")) f = stdin; else { r = search_and_fopen(fn, "re", arg_root, (const char**) CONF_PATHS_STRV("sysusers.d"), &rf); if (r < 0) { if (ignore_enoent && r == -ENOENT) return 0; return log_error_errno(r, "Failed to open '%s', ignoring: %m", fn); } f = rf; } for (;;) { _cleanup_free_ char *line = NULL; char *l; int k; k = read_line(f, LONG_LINE_MAX, &line); if (k < 0) return log_error_errno(k, "Failed to read '%s': %m", fn); if (k == 0) break; v++; l = strstrip(line); if (IN_SET(*l, 0, '#')) continue; k = parse_line(fn, v, l); if (k < 0 && r == 0) r = k; } if (ferror(f)) { log_error_errno(errno, "Failed to read from file %s: %m", fn); if (r == 0) r = -EIO; } return r; } 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; (void) pager_open(arg_pager_flags); return cat_files(NULL, files, 0); } static int help(void) { _cleanup_free_ char *link = NULL; int r; r = terminal_urlify_man("systemd-sysusers.service", "8", &link); if (r < 0) return log_oom(); printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n" "Creates system user accounts.\n\n" " -h --help Show this help\n" " --version Show package version\n" " --cat-config Show configuration files\n" " --root=PATH Operate on an alternate filesystem root\n" " --replace=PATH Treat arguments as replacement for PATH\n" " --inline Treat arguments as configuration lines\n" " --no-pager Do not pipe output into a pager\n" "\nSee the %s for details.\n" , program_invocation_short_name , link ); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_CAT_CONFIG, ARG_ROOT, ARG_REPLACE, ARG_INLINE, ARG_NO_PAGER, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "cat-config", no_argument, NULL, ARG_CAT_CONFIG }, { "root", required_argument, NULL, ARG_ROOT }, { "replace", required_argument, NULL, ARG_REPLACE }, { "inline", no_argument, NULL, ARG_INLINE }, { "no-pager", no_argument, NULL, ARG_NO_PAGER }, {} }; int c, r; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) switch (c) { case 'h': return help(); case ARG_VERSION: return version(); case ARG_CAT_CONFIG: arg_cat_config = true; break; case ARG_ROOT: r = parse_path_argument_and_warn(optarg, true, &arg_root); if (r < 0) return r; break; case ARG_REPLACE: if (!path_is_absolute(optarg) || !endswith(optarg, ".conf")) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "The argument to --replace= must an absolute path to a config file"); arg_replace = optarg; break; case ARG_INLINE: arg_inline = true; break; case ARG_NO_PAGER: arg_pager_flags |= PAGER_DISABLE; break; case '?': return -EINVAL; default: assert_not_reached("Unhandled option"); } if (arg_replace && arg_cat_config) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Option --replace= is not supported with --cat-config"); if (arg_replace && optind >= argc) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "When --replace= is given, some configuration items must be specified"); return 1; } static int parse_arguments(char **args) { char **arg; unsigned pos = 1; int r; STRV_FOREACH(arg, args) { if (arg_inline) /* Use (argument):n, where n==1 for the first positional arg */ r = parse_line("(argument)", pos, *arg); else r = read_config_file(*arg, false); if (r < 0) return r; pos++; } return 0; } static int read_config_files(char **args) { _cleanup_strv_free_ char **files = NULL; _cleanup_free_ char *p = NULL; char **f; int r; 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\"…", *f); r = parse_arguments(args); if (r < 0) return r; } else { log_debug("Reading config file \"%s\"…", *f); /* Just warn, ignore result otherwise */ (void) read_config_file(*f, true); } return 0; } static int run(int argc, char *argv[]) { _cleanup_close_ int lock = -1; Iterator iterator; Item *i; int r; r = parse_argv(argc, argv); if (r <= 0) return r; log_setup_service(); if (arg_cat_config) return cat_config(); umask(0022); r = mac_selinux_init(); if (r < 0) return log_error_errno(r, "SELinux setup failed: %m"); /* 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 || optind >= argc) r = read_config_files(argv + optind); else r = parse_arguments(argv + optind); 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 (!uid_range) { /* Default to default range of 1..SYSTEM_UID_MAX */ r = uid_range_add(&uid_range, &n_uid_range, 1, SYSTEM_UID_MAX); if (r < 0) return log_oom(); } r = add_implicit(); if (r < 0) return r; 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(); if (r < 0) return log_error_errno(r, "Failed to load user database: %m"); r = load_group_database(); if (r < 0) return log_error_errno(r, "Failed to read group database: %m"); ORDERED_HASHMAP_FOREACH(i, groups, iterator) (void) process_item(i); ORDERED_HASHMAP_FOREACH(i, users, iterator) (void) process_item(i); r = write_files(); if (r < 0) return log_error_errno(r, "Failed to write files: %m"); return 0; } DEFINE_MAIN_FUNCTION(run);