/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2014 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <pwd.h> #include <grp.h> #include <shadow.h> #include <gshadow.h> #include <getopt.h> #include <utmp.h> #include "util.h" #include "hashmap.h" #include "specifier.h" #include "path-util.h" #include "build.h" #include "strv.h" #include "conf-files.h" #include "copy.h" #include "utf8.h" #include "fileio-label.h" #include "uid-range.h" #include "selinux-util.h" #include "formats-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; gid_t gid; uid_t uid; bool gid_set:1; bool uid_set:1; bool todo_user:1; bool todo_group:1; } Item; static char *arg_root = NULL; static const char conf_file_dirs[] = CONF_DIRS_NULSTR("sysusers"); static Hashmap *users = NULL, *groups = NULL; static Hashmap *todo_uids = NULL, *todo_gids = NULL; static Hashmap *members = NULL; static Hashmap *database_uid = NULL, *database_user = NULL; static Hashmap *database_gid = NULL, *database_group = NULL; static uid_t search_uid = UID_INVALID; static UidRange *uid_range = NULL; static unsigned n_uid_range = 0; #define fix_root(x) (arg_root ? strjoina(arg_root, x) : x) static int load_user_database(void) { _cleanup_fclose_ FILE *f = NULL; const char *passwd_path; struct passwd *pw; int r; passwd_path = fix_root("/etc/passwd"); f = fopen(passwd_path, "re"); if (!f) return errno == ENOENT ? 0 : -errno; r = hashmap_ensure_allocated(&database_user, &string_hash_ops); if (r < 0) return r; r = hashmap_ensure_allocated(&database_uid, NULL); if (r < 0) return r; errno = 0; while ((pw = fgetpwent(f))) { char *n; int k, q; n = strdup(pw->pw_name); if (!n) return -ENOMEM; k = hashmap_put(database_user, n, UID_TO_PTR(pw->pw_uid)); if (k < 0 && k != -EEXIST) { free(n); return k; } q = hashmap_put(database_uid, UID_TO_PTR(pw->pw_uid), n); if (q < 0 && q != -EEXIST) { if (k < 0) free(n); return q; } if (q < 0 && k < 0) free(n); errno = 0; } if (!IN_SET(errno, 0, ENOENT)) return -errno; return 0; } static int load_group_database(void) { _cleanup_fclose_ FILE *f = NULL; const char *group_path; struct group *gr; int r; group_path = fix_root("/etc/group"); f = fopen(group_path, "re"); if (!f) return errno == ENOENT ? 0 : -errno; r = hashmap_ensure_allocated(&database_group, &string_hash_ops); if (r < 0) return r; r = hashmap_ensure_allocated(&database_gid, NULL); if (r < 0) return r; errno = 0; while ((gr = fgetgrent(f))) { char *n; int k, q; n = strdup(gr->gr_name); if (!n) return -ENOMEM; k = hashmap_put(database_group, n, GID_TO_PTR(gr->gr_gid)); if (k < 0 && k != -EEXIST) { free(n); return k; } q = hashmap_put(database_gid, GID_TO_PTR(gr->gr_gid), n); if (q < 0 && q != -EEXIST) { if (k < 0) free(n); return q; } if (q < 0 && k < 0) free(n); errno = 0; } if (!IN_SET(errno, 0, ENOENT)) return -errno; return 0; } static int make_backup(const char *target, const char *x) { _cleanup_close_ int src = -1; _cleanup_fclose_ FILE *dst = NULL; char *backup, *temp; 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), (off_t) -1, true); 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 */ if (fchmod(fileno(dst), st.st_mode & 07777) < 0) log_warning_errno(errno, "Failed to change mode on %s: %m", backup); if (fchown(fileno(dst), st.st_uid, st.st_gid)< 0) log_warning_errno(errno, "Failed to change 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); if (rename(temp, backup) < 0) goto fail; return 0; fail: unlink(temp); return r; } static int putgrent_with_members(const struct group *gr, FILE *group) { char **a; assert(gr); assert(group); a = 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; strv_uniq(l); strv_sort(l); t = *gr; t.gr_mem = l; errno = 0; if (putgrent(&t, group) != 0) return errno ? -errno : -EIO; return 1; } } errno = 0; if (putgrent(gr, group) != 0) return errno ? -errno : -EIO; return 0; } static int putsgent_with_members(const struct sgrp *sg, FILE *gshadow) { char **a; assert(sg); assert(gshadow); a = 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; strv_uniq(l); strv_sort(l); t = *sg; t.sg_mem = l; errno = 0; if (putsgent(&t, gshadow) != 0) return errno ? -errno : -EIO; return 1; } } errno = 0; if (putsgent(sg, gshadow) != 0) return errno ? -errno : -EIO; return 0; } static int sync_rights(FILE *from, FILE *to) { struct stat st; if (fstat(fileno(from), &st) < 0) return -errno; if (fchmod(fileno(to), st.st_mode & 07777) < 0) return -errno; if (fchown(fileno(to), st.st_uid, st.st_gid) < 0) return -errno; return 0; } static int write_files(void) { _cleanup_fclose_ FILE *passwd = NULL, *group = NULL, *shadow = NULL, *gshadow = NULL; _cleanup_free_ 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; bool group_changed = false; Iterator iterator; Item *i; int r; if (hashmap_size(todo_gids) > 0 || hashmap_size(members) > 0) { _cleanup_fclose_ FILE *original = NULL; /* First we update the actual group list file */ group_path = fix_root("/etc/group"); r = fopen_temporary_label("/etc/group", group_path, &group, &group_tmp); if (r < 0) goto finish; original = fopen(group_path, "re"); if (original) { struct group *gr; r = sync_rights(original, group); if (r < 0) goto finish; errno = 0; while ((gr = fgetgrent(original))) { /* 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 = hashmap_get(groups, gr->gr_name); if (i && i->todo_group) { r = -EEXIST; goto finish; } if (hashmap_contains(todo_gids, GID_TO_PTR(gr->gr_gid))) { r = -EEXIST; goto finish; } r = putgrent_with_members(gr, group); if (r < 0) goto finish; if (r > 0) group_changed = true; errno = 0; } if (!IN_SET(errno, 0, ENOENT)) { r = -errno; goto finish; } } else if (errno != ENOENT) { r = -errno; goto finish; } else if (fchmod(fileno(group), 0644) < 0) { r = -errno; goto finish; } 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) goto finish; group_changed = true; } r = fflush_and_check(group); if (r < 0) goto finish; if (original) { fclose(original); original = NULL; } /* OK, now also update the shadow file for the group list */ gshadow_path = fix_root("/etc/gshadow"); r = fopen_temporary_label("/etc/gshadow", gshadow_path, &gshadow, &gshadow_tmp); if (r < 0) goto finish; original = fopen(gshadow_path, "re"); if (original) { struct sgrp *sg; r = sync_rights(original, gshadow); if (r < 0) goto finish; errno = 0; while ((sg = fgetsgent(original))) { i = hashmap_get(groups, sg->sg_namp); if (i && i->todo_group) { r = -EEXIST; goto finish; } r = putsgent_with_members(sg, gshadow); if (r < 0) goto finish; if (r > 0) group_changed = true; errno = 0; } if (!IN_SET(errno, 0, ENOENT)) { r = -errno; goto finish; } } else if (errno != ENOENT) { r = -errno; goto finish; } else if (fchmod(fileno(gshadow), 0000) < 0) { r = -errno; goto finish; } 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) goto finish; group_changed = true; } r = fflush_and_check(gshadow); if (r < 0) goto finish; } if (hashmap_size(todo_uids) > 0) { _cleanup_fclose_ FILE *original = NULL; long lstchg; /* First we update the user database itself */ passwd_path = fix_root("/etc/passwd"); r = fopen_temporary_label("/etc/passwd", passwd_path, &passwd, &passwd_tmp); if (r < 0) goto finish; original = fopen(passwd_path, "re"); if (original) { struct passwd *pw; r = sync_rights(original, passwd); if (r < 0) goto finish; errno = 0; while ((pw = fgetpwent(original))) { i = hashmap_get(users, pw->pw_name); if (i && i->todo_user) { r = -EEXIST; goto finish; } if (hashmap_contains(todo_uids, UID_TO_PTR(pw->pw_uid))) { r = -EEXIST; goto finish; } errno = 0; if (putpwent(pw, passwd) < 0) { r = errno ? -errno : -EIO; goto finish; } errno = 0; } if (!IN_SET(errno, 0, ENOENT)) { r = -errno; goto finish; } } else if (errno != ENOENT) { r = -errno; goto finish; } else if (fchmod(fileno(passwd), 0644) < 0) { r = -errno; goto finish; } 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->uid == 0 ? (char*) "/bin/sh" : (char*) "/sbin/nologin", }; errno = 0; if (putpwent(&n, passwd) != 0) { r = errno ? -errno : -EIO; goto finish; } } r = fflush_and_check(passwd); if (r < 0) goto finish; if (original) { fclose(original); original = NULL; } /* The we update the shadow database */ shadow_path = fix_root("/etc/shadow"); r = fopen_temporary_label("/etc/shadow", shadow_path, &shadow, &shadow_tmp); if (r < 0) goto finish; lstchg = (long) (now(CLOCK_REALTIME) / USEC_PER_DAY); original = fopen(shadow_path, "re"); if (original) { struct spwd *sp; r = sync_rights(original, shadow); if (r < 0) goto finish; errno = 0; while ((sp = fgetspent(original))) { i = 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; hashmap_remove(todo_uids, UID_TO_PTR(i->uid)); } errno = 0; if (putspent(sp, shadow) < 0) { r = errno ? -errno : -EIO; goto finish; } errno = 0; } if (!IN_SET(errno, 0, ENOENT)) { r = -errno; goto finish; } } else if (errno != ENOENT) { r = -errno; goto finish; } else if (fchmod(fileno(shadow), 0000) < 0) { r = -errno; goto finish; } 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 ... */ }; errno = 0; if (putspent(&n, shadow) != 0) { r = errno ? -errno : -EIO; goto finish; } } r = fflush_and_check(shadow); if (r < 0) goto finish; } /* Make a backup of the old files */ if (group_changed) { if (group) { r = make_backup("/etc/group", group_path); if (r < 0) goto finish; } if (gshadow) { r = make_backup("/etc/gshadow", gshadow_path); if (r < 0) goto finish; } } if (passwd) { r = make_backup("/etc/passwd", passwd_path); if (r < 0) goto finish; } if (shadow) { r = make_backup("/etc/shadow", shadow_path); if (r < 0) goto finish; } /* And make the new files count */ if (group_changed) { if (group) { if (rename(group_tmp, group_path) < 0) { r = -errno; goto finish; } free(group_tmp); group_tmp = NULL; } if (gshadow) { if (rename(gshadow_tmp, gshadow_path) < 0) { r = -errno; goto finish; } free(gshadow_tmp); gshadow_tmp = NULL; } } if (passwd) { if (rename(passwd_tmp, passwd_path) < 0) { r = -errno; goto finish; } free(passwd_tmp); passwd_tmp = NULL; } if (shadow) { if (rename(shadow_tmp, shadow_path) < 0) { r = -errno; goto finish; } free(shadow_tmp); shadow_tmp = NULL; } r = 0; finish: if (passwd_tmp) unlink(passwd_tmp); if (shadow_tmp) unlink(shadow_tmp); if (group_tmp) unlink(group_tmp); if (gshadow_tmp) unlink(gshadow_tmp); return r; } static int uid_is_ok(uid_t uid, const char *name) { 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 (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. */ i = 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_uid, UID_TO_PTR(uid))) return 0; n = hashmap_get(database_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; 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 = fix_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_user, 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; free(i->description); i->description = strdup(p->pw_gecos); 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); 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); 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); 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); 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 = hashmap_ensure_allocated(&todo_uids, NULL); if (r < 0) return log_oom(); r = 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 (hashmap_get(todo_gids, GID_TO_PTR(gid))) return 0; /* Avoid reusing gids that are already used by a different user */ if (hashmap_get(todo_uids, UID_TO_PTR(gid))) return 0; if (hashmap_contains(database_gid, GID_TO_PTR(gid))) return 0; if (hashmap_contains(database_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_group, 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 (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 = hashmap_ensure_allocated(&todo_gids, NULL); if (r < 0) return log_oom(); r = 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: r = add_group(i); if (r < 0) return r; return add_user(i); case ADD_GROUP: { Item *j; j = hashmap_get(users, i->name); if (j) { /* There's already user to be created for this * name, let's process that in one step */ if (i->gid_set) { j->gid = i->gid; j->gid_set = true; } if (i->gid_path) { free(j->gid_path); j->gid_path = strdup(i->gid_path); if (!j->gid_path) return log_oom(); } return 0; } return add_group(i); } default: assert_not_reached("Unknown item type"); } } static void item_free(Item *i) { if (!i) return; free(i->name); free(i->uid_path); free(i->gid_path); free(i->description); free(i); } DEFINE_TRIVIAL_CLEANUP_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 */ HASHMAP_FOREACH_KEY(l, g, members, iterator) { Item *i; char **m; i = hashmap_get(groups, g); if (!i) { _cleanup_(item_freep) Item *j = NULL; r = hashmap_ensure_allocated(&groups, &string_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 = 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; } STRV_FOREACH(m, l) { i = hashmap_get(users, *m); if (!i) { _cleanup_(item_freep) Item *j = NULL; r = hashmap_ensure_allocated(&users, &string_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 = 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; } } } 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; return true; } static bool valid_user_group_name(const char *u) { const char *i; long sz; if (isempty(u)) return false; if (!(u[0] >= 'a' && u[0] <= 'z') && !(u[0] >= 'A' && u[0] <= 'Z') && u[0] != '_') return false; for (i = u+1; *i; i++) { if (!(*i >= 'a' && *i <= 'z') && !(*i >= 'A' && *i <= 'Z') && !(*i >= '0' && *i <= '9') && *i != '_' && *i != '-') return false; } sz = sysconf(_SC_LOGIN_NAME_MAX); assert_se(sz > 0); if ((size_t) (i-u) > (size_t) sz) return false; if ((size_t) (i-u) > UT_NAMESIZE - 1) return false; return true; } static bool valid_gecos(const char *d) { if (!d) return false; if (!utf8_is_valid(d)) return false; if (string_has_cc(d, NULL)) return false; /* Colons are used as field separators, and hence not OK */ if (strchr(d, ':')) return false; return true; } static bool valid_home(const char *p) { if (isempty(p)) return false; if (!utf8_is_valid(p)) return false; if (string_has_cc(p, NULL)) return false; if (!path_is_absolute(p)) return false; if (!path_is_safe(p)) return false; /* Colons are used as field separators, and hence not OK */ if (strchr(p, ':')) return false; return true; } 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 }, {} }; _cleanup_free_ char *action = NULL, *name = NULL, *id = NULL, *resolved_name = NULL, *resolved_id = NULL, *description = NULL, *home = NULL; _cleanup_(item_freep) Item *i = NULL; Item *existing; Hashmap *h; int r; const char *p; assert(fname); assert(line >= 1); assert(buffer); /* Parse columns */ p = buffer; r = unquote_many_words(&p, 0, &action, &name, &id, &description, &home, 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 (*p != 0) { 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 command type '%c'.", fname, line, action[0]); return -EBADMSG; } /* Verify name */ if (isempty(name) || streq(name, "-")) { free(name); name = NULL; } 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, "-")) { free(id); id = NULL; } 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, "-")) { free(description); description = NULL; } if (description) { if (!valid_gecos(description)) { log_error("[%s:%u] '%s' is not a valid GECOS field.", fname, line, description); return -EINVAL; } } /* Verify home */ if (isempty(home) || streq(home, "-")) { free(home); home = NULL; } if (home) { if (!valid_home(home)) { log_error("[%s:%u] '%s' is not a valid home directory field.", fname, line, home); 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) { log_error("[%s:%u] Lines of type 'r' don't take a GECOS field.", fname, line); return -EINVAL; } if (home) { log_error("[%s:%u] Lines of type 'r' don't take a home directory field.", fname, line); 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) { log_error("[%s:%u] Lines of type 'm' don't take a GECOS field.", fname, line); return -EINVAL; } if (home) { log_error("[%s:%u] Lines of type 'm' don't take a home directory field.", fname, line); return -EINVAL; } r = hashmap_ensure_allocated(&members, &string_hash_ops); if (r < 0) return log_oom(); l = 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(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 = 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 = hashmap_ensure_allocated(&users, &string_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 = resolved_id; resolved_id = NULL; path_kill_slashes(i->uid_path); } else { r = parse_uid(resolved_id, &i->uid); if (r < 0) { log_error("Failed to parse UID: %s", id); return -EBADMSG; } i->uid_set = true; } } i->description = description; description = NULL; i->home = home; home = NULL; 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) { log_error("[%s:%u] Lines of type 'g' don't take a GECOS field.", fname, line); return -EINVAL; } if (home) { log_error("[%s:%u] Lines of type 'g' don't take a home directory field.", fname, line); return -EINVAL; } r = hashmap_ensure_allocated(&groups, &string_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 = resolved_id; resolved_id = NULL; path_kill_slashes(i->gid_path); } else { r = parse_gid(resolved_id, &i->gid); if (r < 0) { log_error("Failed to parse GID: %s", id); return -EBADMSG; } i->gid_set = true; } } h = groups; break; default: return -EBADMSG; } i->type = action[0]; i->name = resolved_name; resolved_name = NULL; existing = 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 = 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; char line[LINE_MAX]; unsigned v = 0; int r = 0; assert(fn); if (streq(fn, "-")) f = stdin; else { r = search_and_fopen_nulstr(fn, "re", arg_root, conf_file_dirs, &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; } FOREACH_LINE(line, f, break) { char *l; int k; v++; l = strstrip(line); if (*l == '#' || *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 void free_database(Hashmap *by_name, Hashmap *by_id) { char *name; for (;;) { name = hashmap_first(by_id); if (!name) break; hashmap_remove(by_name, name); hashmap_steal_first_key(by_id); free(name); } while ((name = hashmap_steal_first_key(by_name))) free(name); hashmap_free(by_name); hashmap_free(by_id); } static void help(void) { printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n" "Creates system user accounts.\n\n" " -h --help Show this help\n" " --version Show package version\n" " --root=PATH Operate on an alternate filesystem root\n" , program_invocation_short_name); } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_ROOT, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "root", required_argument, NULL, ARG_ROOT }, {} }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) switch (c) { case 'h': help(); return 0; case ARG_VERSION: puts(PACKAGE_STRING); puts(SYSTEMD_FEATURES); return 0; case ARG_ROOT: free(arg_root); arg_root = path_make_absolute_cwd(optarg); if (!arg_root) return log_oom(); path_kill_slashes(arg_root); break; case '?': return -EINVAL; default: assert_not_reached("Unhandled option"); } return 1; } int main(int argc, char *argv[]) { _cleanup_close_ int lock = -1; Iterator iterator; int r, k; Item *i; char *n; r = parse_argv(argc, argv); if (r <= 0) goto finish; log_set_target(LOG_TARGET_AUTO); log_parse_environment(); log_open(); umask(0022); r = mac_selinux_init(NULL); if (r < 0) { log_error_errno(r, "SELinux setup failed: %m"); goto finish; } if (optind < argc) { int j; for (j = optind; j < argc; j++) { k = read_config_file(argv[j], false); if (k < 0 && r == 0) r = k; } } else { _cleanup_strv_free_ char **files = NULL; char **f; r = conf_files_list_nulstr(&files, ".conf", arg_root, conf_file_dirs); if (r < 0) { log_error_errno(r, "Failed to enumerate sysusers.d files: %m"); goto finish; } STRV_FOREACH(f, files) { k = read_config_file(*f, true); if (k < 0 && r == 0) r = k; } } if (!uid_range) { /* Default to default range of 1..SYSTEMD_UID_MAX */ r = uid_range_add(&uid_range, &n_uid_range, 1, SYSTEM_UID_MAX); if (r < 0) { log_oom(); goto finish; } } r = add_implicit(); if (r < 0) goto finish; lock = take_password_lock(arg_root); if (lock < 0) { log_error_errno(lock, "Failed to take lock: %m"); goto finish; } r = load_user_database(); if (r < 0) { log_error_errno(r, "Failed to load user database: %m"); goto finish; } r = load_group_database(); if (r < 0) { log_error_errno(r, "Failed to read group database: %m"); goto finish; } HASHMAP_FOREACH(i, groups, iterator) process_item(i); HASHMAP_FOREACH(i, users, iterator) process_item(i); r = write_files(); if (r < 0) log_error_errno(r, "Failed to write files: %m"); finish: while ((i = hashmap_steal_first(groups))) item_free(i); while ((i = hashmap_steal_first(users))) item_free(i); while ((n = hashmap_first_key(members))) { strv_free(hashmap_steal_first(members)); free(n); } hashmap_free(groups); hashmap_free(users); hashmap_free(members); hashmap_free(todo_uids); hashmap_free(todo_gids); free_database(database_user, database_uid); free_database(database_group, database_gid); free(arg_root); return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }