/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 .
***/
#include
#include
#include
#include
#include
#include
#include "alloc-util.h"
#include "conf-files.h"
#include "copy.h"
#include "def.h"
#include "fd-util.h"
#include "fs-util.h"
#include "fileio-label.h"
#include "format-util.h"
#include "hashmap.h"
#include "path-util.h"
#include "selinux-util.h"
#include "smack-util.h"
#include "specifier.h"
#include "string-util.h"
#include "strv.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;
// id_set_strict means that the group with the specified gid must
// exist and that the check if a uid clashes with a 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_inline = false;
static const char conf_file_dirs[] = CONF_PATHS_NULSTR("sysusers.d");
static OrderedHashmap *users = NULL, *groups = NULL;
static OrderedHashmap *todo_uids = NULL, *todo_gids = NULL;
static OrderedHashmap *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;
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_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 = prefix_roota(arg_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;
_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 */
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);
r = fflush_sync_and_check(dst);
if (r < 0)
goto fail;
if (rename(temp, backup) < 0) {
r = -errno;
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 = 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;
strv_uniq(l);
strv_sort(l);
t = *gr;
t.gr_mem = l;
errno = 0;
if (putgrent(&t, group) != 0)
return errno > 0 ? -errno : -EIO;
return 1;
}
}
errno = 0;
if (putgrent(gr, group) != 0)
return errno > 0 ? -errno : -EIO;
return 0;
}
#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;
strv_uniq(l);
strv_sort(l);
t = *sg;
t.sg_mem = l;
errno = 0;
if (putsgent(&t, gshadow) != 0)
return errno > 0 ? -errno : -EIO;
return 1;
}
}
errno = 0;
if (putsgent(sg, gshadow) != 0)
return errno > 0 ? -errno : -EIO;
return 0;
}
#endif
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 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;
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) {
struct passwd *pw;
r = sync_rights(original, passwd);
if (r < 0)
return r;
errno = 0;
while ((pw = fgetpwent(original))) {
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;
}
errno = 0;
if (putpwent(pw, passwd) < 0)
return errno ? -errno : -EIO;
errno = 0;
}
if (!IN_SET(errno, 0, ENOENT))
return -errno;
} 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),
};
errno = 0;
if (putpwent(&n, passwd) != 0)
return errno ? -errno : -EIO;
}
r = fflush_and_check(passwd);
if (r < 0)
return r;
*tmpfile = passwd;
*tmpfile_path = passwd_tmp;
passwd = NULL;
passwd_tmp = NULL;
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;
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) {
struct spwd *sp;
r = sync_rights(original, shadow);
if (r < 0)
return r;
errno = 0;
while ((sp = fgetspent(original))) {
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));
}
errno = 0;
if (putspent(sp, shadow) < 0)
return errno ? -errno : -EIO;
errno = 0;
}
if (!IN_SET(errno, 0, ENOENT))
return -errno;
} 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 ... */
};
errno = 0;
if (putspent(&n, shadow) != 0)
return errno ? -errno : -EIO;
}
r = fflush_sync_and_check(shadow);
if (r < 0)
return r;
*tmpfile = shadow;
*tmpfile_path = shadow_tmp;
shadow = NULL;
shadow_tmp = NULL;
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;
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) {
struct group *gr;
r = sync_rights(original, group);
if (r < 0)
return r;
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 = 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;
}
r = putgrent_with_members(gr, group);
if (r < 0)
return r;
if (r > 0)
group_changed = true;
errno = 0;
}
if (!IN_SET(errno, 0, ENOENT))
return -errno;
} 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;
}
r = fflush_sync_and_check(group);
if (r < 0)
return r;
if (group_changed) {
*tmpfile = group;
*tmpfile_path = group_tmp;
group = NULL;
group_tmp = NULL;
}
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;
errno = 0;
while ((sg = fgetsgent(original))) {
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;
errno = 0;
}
if (!IN_SET(errno, 0, ENOENT))
return -errno;
} 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 = gshadow;
*tmpfile_path = gshadow_tmp;
gshadow = NULL;
gshadow_tmp = NULL;
}
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_uid, UID_TO_PTR(uid)))
return 0;
if (check_with_gid) {
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;
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_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;
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_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 (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) {
log_error("Failed to create %s: please create GID %d", i->name, i->gid);
return -EINVAL;
}
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:
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 void item_free(Item *i) {
if (!i)
return;
free(i->name);
free(i->uid_path);
free(i->gid_path);
free(i->description);
free(i->home);
free(i->shell);
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 */
ORDERED_HASHMAP_FOREACH_KEY(l, g, members, iterator) {
Item *i;
char **m;
i = ordered_hashmap_get(groups, g);
if (!i) {
_cleanup_(item_freep) Item *j = NULL;
r = ordered_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 = 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;
}
STRV_FOREACH(m, l) {
i = ordered_hashmap_get(users, *m);
if (!i) {
_cleanup_(item_freep) Item *j = NULL;
r = ordered_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 = 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;
}
}
}
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;
}
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, *resolved_name = NULL,
*id = NULL, *resolved_id = NULL,
*description = NULL,
*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) {
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, "-"))
home = mfree(home);
if (home) {
if (!valid_home(home)) {
log_error("[%s:%u] '%s' is not a valid home directory field.", fname, line, 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, &string_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, &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 {
_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);
}
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 = description;
description = NULL;
i->home = home;
home = NULL;
i->shell = resolved_shell;
resolved_shell = 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 || 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, &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)
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 = resolved_name;
resolved_name = NULL;
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;
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 (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 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"
" --inline Treat arguments as configuration lines\n"
, program_invocation_short_name);
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_ROOT,
ARG_INLINE,
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "root", required_argument, NULL, ARG_ROOT },
{ "inline", no_argument, NULL, ARG_INLINE },
{}
};
int c, r;
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:
return version();
case ARG_ROOT:
r = parse_path_argument_and_warn(optarg, true, &arg_root);
if (r < 0)
return r;
break;
case ARG_INLINE:
arg_inline = true;
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();
if (r < 0) {
log_error_errno(r, "SELinux setup failed: %m");
goto finish;
}
if (optind < argc) {
int j;
for (j = optind; j < argc; j++) {
if (arg_inline)
/* Use (argument):n, where n==1 for the first positional arg */
r = parse_line("(argument)", j - optind + 1, argv[j]);
else
r = read_config_file(argv[j], false);
if (r < 0)
goto finish;
}
} else {
_cleanup_strv_free_ char **files = NULL;
char **f;
r = conf_files_list_nulstr(&files, ".conf", arg_root, 0, 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;
}
}
/* 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) {
r = log_error_errno(errno, "Failed to set SYSTEMD_NSS_BYPASS_SYNTHETIC environment variable: %m");
goto finish;
}
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) {
log_oom();
goto finish;
}
}
r = add_implicit();
if (r < 0)
goto finish;
lock = take_etc_passwd_lock(arg_root);
if (lock < 0) {
log_error_errno(lock, "Failed to take /etc/passwd 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;
}
ORDERED_HASHMAP_FOREACH(i, groups, iterator)
process_item(i);
ORDERED_HASHMAP_FOREACH(i, users, iterator)
process_item(i);
r = write_files();
if (r < 0)
log_error_errno(r, "Failed to write files: %m");
finish:
ordered_hashmap_free_with_destructor(groups, item_free);
ordered_hashmap_free_with_destructor(users, item_free);
while ((n = ordered_hashmap_first_key(members))) {
strv_free(ordered_hashmap_steal_first(members));
free(n);
}
ordered_hashmap_free(members);
ordered_hashmap_free(todo_uids);
ordered_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;
}