/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "conf-files.h"
#include "dirent-util.h"
#include "dropin.h"
#include "escape.h"
#include "fd-util.h"
#include "fileio-label.h"
#include "fs-util.h"
#include "hashmap.h"
#include "log.h"
#include "macro.h"
#include "mkdir.h"
#include "path-util.h"
#include "set.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
int drop_in_file(const char *dir, const char *unit, unsigned level,
const char *name, char **_p, char **_q) {
char prefix[DECIMAL_STR_MAX(unsigned)];
_cleanup_free_ char *b = NULL;
char *p, *q;
assert(unit);
assert(name);
assert(_p);
assert(_q);
sprintf(prefix, "%u", level);
b = xescape(name, "/.");
if (!b)
return -ENOMEM;
if (!filename_is_valid(b))
return -EINVAL;
p = strjoin(dir, "/", unit, ".d");
if (!p)
return -ENOMEM;
q = strjoin(p, "/", prefix, "-", b, ".conf");
if (!q) {
free(p);
return -ENOMEM;
}
*_p = p;
*_q = q;
return 0;
}
int write_drop_in(const char *dir, const char *unit, unsigned level,
const char *name, const char *data) {
_cleanup_free_ char *p = NULL, *q = NULL;
int r;
assert(dir);
assert(unit);
assert(name);
assert(data);
r = drop_in_file(dir, unit, level, name, &p, &q);
if (r < 0)
return r;
(void) mkdir_p(p, 0755);
return write_string_file_atomic_label(q, data);
}
int write_drop_in_format(const char *dir, const char *unit, unsigned level,
const char *name, const char *format, ...) {
_cleanup_free_ char *p = NULL;
va_list ap;
int r;
assert(dir);
assert(unit);
assert(name);
assert(format);
va_start(ap, format);
r = vasprintf(&p, format, ap);
va_end(ap);
if (r < 0)
return -ENOMEM;
return write_drop_in(dir, unit, level, name, p);
}
static int unit_file_find_dir(
const char *original_root,
const char *path,
char ***dirs) {
_cleanup_free_ char *chased = NULL;
int r;
assert(path);
r = chase_symlinks(path, original_root, 0, &chased);
if (r == -ENOENT) /* Ignore -ENOENT, after all most units won't have a drop-in dir. */
return 0;
if (r == -ENAMETOOLONG) {
/* Also, ignore -ENAMETOOLONG but log about it. After all, users are not even able to create the
* drop-in dir in such case. This mostly happens for device units with an overly long /sys path. */
log_debug_errno(r, "Path '%s' too long, couldn't canonicalize, ignoring.", path);
return 0;
}
if (r < 0)
return log_warning_errno(r, "Failed to canonicalize path '%s': %m", path);
r = strv_push(dirs, chased);
if (r < 0)
return log_oom();
chased = NULL;
return 0;
}
static int unit_file_find_dirs(
const char *original_root,
Set *unit_path_cache,
const char *unit_path,
const char *name,
const char *suffix,
char ***dirs) {
_cleanup_free_ char *prefix = NULL, *instance = NULL, *built = NULL;
bool is_instance, chopped;
const char *dash;
UnitType type;
char *path;
size_t n;
int r;
assert(unit_path);
assert(name);
assert(suffix);
path = strjoina(unit_path, "/", name, suffix);
if (!unit_path_cache || set_get(unit_path_cache, path)) {
r = unit_file_find_dir(original_root, path, dirs);
if (r < 0)
return r;
}
is_instance = unit_name_is_valid(name, UNIT_NAME_INSTANCE);
if (is_instance) { /* Also try the template dir */
_cleanup_free_ char *template = NULL;
r = unit_name_template(name, &template);
if (r < 0)
return log_error_errno(r, "Failed to generate template from unit name: %m");
r = unit_file_find_dirs(original_root, unit_path_cache, unit_path, template, suffix, dirs);
if (r < 0)
return r;
}
/* Let's see if there's a "-" prefix for this unit name. If so, let's invoke ourselves for it. This will then
* recursively do the same for all our prefixes. i.e. this means given "foo-bar-waldo.service" we'll also
* search "foo-bar-.service" and "foo-.service".
*
* Note the order in which we do it: we traverse up adding drop-ins on each step. This means the more specific
* drop-ins may override the more generic drop-ins, which is the intended behaviour. */
r = unit_name_to_prefix(name, &prefix);
if (r < 0)
return log_error_errno(r, "Failed to derive unit name prefix from unit name: %m");
chopped = false;
for (;;) {
dash = strrchr(prefix, '-');
if (!dash) /* No dash? if so we are done */
return 0;
n = (size_t) (dash - prefix);
if (n == 0) /* Leading dash? If so, we are done */
return 0;
if (prefix[n+1] != 0 || chopped) {
prefix[n+1] = 0;
break;
}
/* Trailing dash? If so, chop it off and try again, but not more than once. */
prefix[n] = 0;
chopped = true;
}
if (!unit_prefix_is_valid(prefix))
return 0;
type = unit_name_to_type(name);
if (type < 0) {
log_error("Failed to to derive unit type from unit name: %s", name);
return -EINVAL;
}
if (is_instance) {
r = unit_name_to_instance(name, &instance);
if (r < 0)
return log_error_errno(r, "Failed to derive unit name instance from unit name: %m");
}
r = unit_name_build_from_type(prefix, instance, type, &built);
if (r < 0)
return log_error_errno(r, "Failed to build prefix unit name: %m");
return unit_file_find_dirs(original_root, unit_path_cache, unit_path, built, suffix, dirs);
}
int unit_file_find_dropin_paths(
const char *original_root,
char **lookup_path,
Set *unit_path_cache,
const char *dir_suffix,
const char *file_suffix,
Set *names,
char ***ret) {
_cleanup_strv_free_ char **dirs = NULL;
char *t, **p;
Iterator i;
int r;
assert(ret);
SET_FOREACH(t, names, i)
STRV_FOREACH(p, lookup_path)
(void) unit_file_find_dirs(original_root, unit_path_cache, *p, t, dir_suffix, &dirs);
if (strv_isempty(dirs)) {
*ret = NULL;
return 0;
}
r = conf_files_list_strv(ret, file_suffix, NULL, 0, (const char**) dirs);
if (r < 0)
return log_warning_errno(r, "Failed to create the list of configuration files: %m");
return 1;
}