src/basic/unit-file.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include "sd-id128.h"
   4
   5 #include "chase-symlinks.h"
   6 #include "dirent-util.h"
   7 #include "fd-util.h"
   8 #include "fs-util.h"
   9 #include "macro.h"
  10 #include "path-lookup.h"
  11 #include "set.h"
  12 #include "special.h"
  13 #include "stat-util.h"
  14 #include "string-util.h"
  15 #include "strv.h"
  16 #include "unit-file.h"
  17
  18 bool unit_type_may_alias(UnitType type) {
  19         return IN_SET(type,
  20                       UNIT_SERVICE,
  21                       UNIT_SOCKET,
  22                       UNIT_TARGET,
  23                       UNIT_DEVICE,
  24                       UNIT_TIMER,
  25                       UNIT_PATH);
  26 }
  27
  28 bool unit_type_may_template(UnitType type) {
  29         return IN_SET(type,
  30                       UNIT_SERVICE,
  31                       UNIT_SOCKET,
  32                       UNIT_TARGET,
  33                       UNIT_TIMER,
  34                       UNIT_PATH);
  35 }
  36
  37 int unit_symlink_name_compatible(const char *symlink, const char *target, bool instance_propagation) {
  38         _cleanup_free_ char *template = NULL;
  39         int r, un_type1, un_type2;
  40
  41         un_type1 = unit_name_classify(symlink);
  42
  43         /* The straightforward case: the symlink name matches the target and we have a valid unit */
  44         if (streq(symlink, target) &&
  45             (un_type1 & (UNIT_NAME_PLAIN | UNIT_NAME_INSTANCE)))
  46                 return 1;
  47
  48         r = unit_name_template(symlink, &template);
  49         if (r == -EINVAL)
  50                 return 0; /* Not a template */
  51         if (r < 0)
  52                 return r;
  53
  54         un_type2 = unit_name_classify(target);
  55
  56         /* An instance name points to a target that is just the template name */
  57         if (un_type1 == UNIT_NAME_INSTANCE &&
  58             un_type2 == UNIT_NAME_TEMPLATE &&
  59             streq(template, target))
  60                 return 1;
  61
  62         /* foo@.target.requires/bar@.service: instance will be propagated */
  63         if (instance_propagation &&
  64             un_type1 == UNIT_NAME_TEMPLATE &&
  65             un_type2 == UNIT_NAME_TEMPLATE &&
  66             streq(template, target))
  67                 return 1;
  68
  69         return 0;
  70 }
  71
  72 int unit_validate_alias_symlink_and_warn(const char *filename, const char *target) {
  73         const char *src, *dst;
  74         _cleanup_free_ char *src_instance = NULL, *dst_instance = NULL;
  75         UnitType src_unit_type, dst_unit_type;
  76         UnitNameFlags src_name_type, dst_name_type;
  77
  78         /* Check if the *alias* symlink is valid. This applies to symlinks like
  79          * /etc/systemd/system/dbus.service → dbus-broker.service, but not to .wants or .requires symlinks
  80          * and such. Neither does this apply to symlinks which *link* units, i.e. symlinks to outside of the
  81          * unit lookup path.
  82          *
  83          * -EINVAL is returned if the something is wrong with the source filename or the source unit type is
  84          *         not allowed to symlink,
  85          * -EXDEV if the target filename is not a valid unit name or doesn't match the source.
  86          */
  87
  88         src = basename(filename);
  89         dst = basename(target);
  90
  91         /* src checks */
  92
  93         src_name_type = unit_name_to_instance(src, &src_instance);
  94         if (src_name_type < 0)
  95                 return log_notice_errno(src_name_type,
  96                                         "%s: not a valid unit name \"%s\": %m", filename, src);
  97
  98         src_unit_type = unit_name_to_type(src);
  99         assert(src_unit_type >= 0); /* unit_name_to_instance() checked the suffix already */
 100
 101         if (!unit_type_may_alias(src_unit_type))
 102                 return log_notice_errno(SYNTHETIC_ERRNO(EINVAL),
 103                                         "%s: symlinks are not allowed for units of this type, rejecting.",
 104                                         filename);
 105
 106         if (src_name_type != UNIT_NAME_PLAIN &&
 107             !unit_type_may_template(src_unit_type))
 108                 return log_notice_errno(SYNTHETIC_ERRNO(EINVAL),
 109                                         "%s: templates not allowed for %s units, rejecting.",
 110                                         filename, unit_type_to_string(src_unit_type));
 111
 112         /* dst checks */
 113
 114         dst_name_type = unit_name_to_instance(dst, &dst_instance);
 115         if (dst_name_type < 0)
 116                 return log_notice_errno(dst_name_type == -EINVAL ? SYNTHETIC_ERRNO(EXDEV) : dst_name_type,
 117                                         "%s points to \"%s\" which is not a valid unit name: %m",
 118                                         filename, dst);
 119
 120         if (!(dst_name_type == src_name_type ||
 121               (src_name_type == UNIT_NAME_INSTANCE && dst_name_type == UNIT_NAME_TEMPLATE)))
 122                 return log_notice_errno(SYNTHETIC_ERRNO(EXDEV),
 123                                         "%s: symlink target name type \"%s\" does not match source, rejecting.",
 124                                         filename, dst);
 125
 126         if (dst_name_type == UNIT_NAME_INSTANCE) {
 127                 assert(src_instance);
 128                 assert(dst_instance);
 129                 if (!streq(src_instance, dst_instance))
 130                         return log_notice_errno(SYNTHETIC_ERRNO(EXDEV),
 131                                                 "%s: unit symlink target \"%s\" instance name doesn't match, rejecting.",
 132                                                 filename, dst);
 133         }
 134
 135         dst_unit_type = unit_name_to_type(dst);
 136         if (dst_unit_type != src_unit_type)
 137                 return log_notice_errno(SYNTHETIC_ERRNO(EXDEV),
 138                                         "%s: symlink target \"%s\" has incompatible suffix, rejecting.",
 139                                         filename, dst);
 140
 141         return 0;
 142 }
 143
 144 #define FOLLOW_MAX 8
 145
 146 static int unit_ids_map_get(
 147                 Hashmap *unit_ids_map,
 148                 const char *unit_name,
 149                 const char **ret_fragment_path) {
 150
 151         /* Resolve recursively until we hit an absolute path, i.e. a non-aliased unit.
 152          *
 153          * We distinguish the case where unit_name was not found in the hashmap at all, and the case where
 154          * some symlink was broken.
 155          *
 156          * If a symlink target points to an instance name, then we also check for the template. */
 157
 158         const char *id = NULL;
 159         int r;
 160
 161         for (unsigned n = 0; n < FOLLOW_MAX; n++) {
 162                 const char *t = hashmap_get(unit_ids_map, id ?: unit_name);
 163                 if (!t) {
 164                         _cleanup_free_ char *template = NULL;
 165
 166                         if (!id)
 167                                 return -ENOENT;
 168
 169                         r = unit_name_template(id, &template);
 170                         if (r == -EINVAL)
 171                                 return -ENXIO; /* we failed to find the symlink target */
 172                         if (r < 0)
 173                                 return log_error_errno(r, "Failed to determine template name for %s: %m", id);
 174
 175                         t = hashmap_get(unit_ids_map, template);
 176                         if (!t)
 177                                 return -ENXIO;
 178
 179                         /* We successfully switched from instanced name to a template, let's continue */
 180                 }
 181
 182                 if (path_is_absolute(t)) {
 183                         if (ret_fragment_path)
 184                                 *ret_fragment_path = t;
 185                         return 0;
 186                 }
 187
 188                 id = t;
 189         }
 190
 191         return -ELOOP;
 192 }
 193
 194 static bool lookup_paths_mtime_exclude(const LookupPaths *lp, const char *path) {
 195         /* Paths that are under our exclusive control. Users shall not alter those directly. */
 196
 197         return streq_ptr(path, lp->generator) ||
 198                streq_ptr(path, lp->generator_early) ||
 199                streq_ptr(path, lp->generator_late) ||
 200                streq_ptr(path, lp->transient) ||
 201                streq_ptr(path, lp->persistent_control) ||
 202                streq_ptr(path, lp->runtime_control);
 203 }
 204
 205 #define HASH_KEY SD_ID128_MAKE(4e,86,1b,e3,39,b3,40,46,98,5d,b8,11,34,8f,c3,c1)
 206
 207 bool lookup_paths_timestamp_hash_same(const LookupPaths *lp, uint64_t timestamp_hash, uint64_t *ret_new) {
 208         struct siphash state;
 209
 210         siphash24_init(&state, HASH_KEY.bytes);
 211
 212         char **dir;
 213         STRV_FOREACH(dir, (char**) lp->search_path) {
 214                 struct stat st;
 215
 216                 if (lookup_paths_mtime_exclude(lp, *dir))
 217                         continue;
 218
 219                 /* Determine the latest lookup path modification time */
 220                 if (stat(*dir, &st) < 0) {
 221                         if (errno == ENOENT)
 222                                 continue;
 223
 224                         log_debug_errno(errno, "Failed to stat %s, ignoring: %m", *dir);
 225                         continue;
 226                 }
 227
 228                 siphash24_compress_usec_t(timespec_load(&st.st_mtim), &state);
 229         }
 230
 231         uint64_t updated = siphash24_finalize(&state);
 232         if (ret_new)
 233                 *ret_new = updated;
 234         if (updated != timestamp_hash)
 235                 log_debug("Modification times have changed, need to update cache.");
 236         return updated == timestamp_hash;
 237 }
 238
 239 int unit_file_build_name_map(
 240                 const LookupPaths *lp,
 241                 uint64_t *cache_timestamp_hash,
 242                 Hashmap **unit_ids_map,
 243                 Hashmap **unit_names_map,
 244                 Set **path_cache) {
 245
 246         /* Build two mappings: any name → main unit (i.e. the end result of symlink resolution), unit name →
 247          * all aliases (i.e. the entry for a given key is a list of all names which point to this key). The
 248          * key is included in the value iff we saw a file or symlink with that name. In other words, if we
 249          * have a key, but it is not present in the value for itself, there was an alias pointing to it, but
 250          * the unit itself is not loadable.
 251          *
 252          * At the same, build a cache of paths where to find units. The non-const parameters are for input
 253          * and output. Existing contents will be freed before the new contents are stored.
 254          */
 255
 256         _cleanup_hashmap_free_ Hashmap *ids = NULL, *names = NULL;
 257         _cleanup_set_free_free_ Set *paths = NULL;
 258         uint64_t timestamp_hash;
 259         char **dir;
 260         int r;
 261
 262         /* Before doing anything, check if the timestamp hash that was passed is still valid.
 263          * If yes, do nothing. */
 264         if (cache_timestamp_hash &&
 265             lookup_paths_timestamp_hash_same(lp, *cache_timestamp_hash, &timestamp_hash))
 266                 return 0;
 267
 268         /* The timestamp hash is now set based on the mtimes from before when we start reading files.
 269          * If anything is modified concurrently, we'll consider the cache outdated. */
 270
 271         if (path_cache) {
 272                 paths = set_new(&path_hash_ops_free);
 273                 if (!paths)
 274                         return log_oom();
 275         }
 276
 277         STRV_FOREACH(dir, (char**) lp->search_path) {
 278                 _cleanup_closedir_ DIR *d = NULL;
 279                 struct dirent *de;
 280
 281                 d = opendir(*dir);
 282                 if (!d) {
 283                         if (errno != ENOENT)
 284                                 log_warning_errno(errno, "Failed to open \"%s\", ignoring: %m", *dir);
 285                         continue;
 286                 }
 287
 288                 FOREACH_DIRENT_ALL(de, d, log_warning_errno(errno, "Failed to read \"%s\", ignoring: %m", *dir)) {
 289                         _unused_ _cleanup_free_ char *_filename_free = NULL;
 290                         _cleanup_free_ char *simplified = NULL;
 291                         const char *dst = NULL;
 292                         char *filename;
 293
 294                         /* We only care about valid units and dirs with certain suffixes, let's ignore the
 295                          * rest. */
 296
 297                         if (IN_SET(de->d_type, DT_REG, DT_LNK)) {
 298
 299                                 if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
 300                                         continue;
 301
 302                                 /* Accept a regular file or symlink whose name is a valid unit file name. */
 303
 304                         } else if (de->d_type == DT_DIR) {
 305                                 bool valid_dir_name = false;
 306                                 const char *suffix;
 307
 308                                 /* Also accept a directory whose name is a valid unit file name ending in
 309                                  * .wants/, .requires/ or .d/ */
 310
 311                                 if (!paths) /* Skip directories early unless path_cache is requested */
 312                                         continue;
 313
 314                                 FOREACH_STRING(suffix, ".wants", ".requires", ".d") {
 315                                         _cleanup_free_ char *chopped = NULL;
 316                                         const char *e;
 317
 318                                         e = endswith(de->d_name, suffix);
 319                                         if (!e)
 320                                                 continue;
 321
 322                                         chopped = strndup(de->d_name, e - de->d_name);
 323                                         if (!chopped)
 324                                                 return log_oom();
 325
 326                                         if (unit_name_is_valid(chopped, UNIT_NAME_ANY) ||
 327                                             unit_type_from_string(chopped) >= 0) {
 328                                                 valid_dir_name = true;
 329                                                 break;
 330                                         }
 331                                 }
 332
 333                                 if (!valid_dir_name)
 334                                         continue;
 335                         } else
 336                                 continue;
 337
 338                         filename = path_join(*dir, de->d_name);
 339                         if (!filename)
 340                                 return log_oom();
 341
 342                         if (paths) {
 343                                 r = set_put(paths, filename);
 344                                 if (r < 0)
 345                                         return log_oom();
 346                                 if (r == 0)
 347                                         _filename_free = filename; /* Make sure we free the filename. */
 348                         } else
 349                                 _filename_free = filename; /* Make sure we free the filename. */
 350
 351                         if (!IN_SET(de->d_type, DT_REG, DT_LNK))
 352                                 continue;
 353
 354                         /* search_path is ordered by priority (highest first). If the name is already mapped
 355                          * to something (incl. itself), it means that we have already seen it, and we should
 356                          * ignore it here. */
 357                         if (hashmap_contains(ids, de->d_name))
 358                                 continue;
 359
 360                         if (de->d_type == DT_LNK) {
 361                                 /* We don't explicitly check for alias loops here. unit_ids_map_get() which
 362                                  * limits the number of hops should be used to access the map. */
 363
 364                                 _cleanup_free_ char *target = NULL;
 365
 366                                 r = readlinkat_malloc(dirfd(d), de->d_name, &target);
 367                                 if (r < 0) {
 368                                         log_warning_errno(r, "Failed to read symlink %s/%s, ignoring: %m",
 369                                                           *dir, de->d_name);
 370                                         continue;
 371                                 }
 372
 373                                 const bool is_abs = path_is_absolute(target);
 374                                 if (lp->root_dir || !is_abs) {
 375                                         char *target_abs = path_join(is_abs ? lp->root_dir : *dir, target);
 376                                         if (!target_abs)
 377                                                 return log_oom();
 378
 379                                         free_and_replace(target, target_abs);
 380                                 }
 381
 382                                 /* Get rid of "." and ".." components in target path */
 383                                 r = chase_symlinks(target, lp->root_dir, CHASE_NOFOLLOW | CHASE_NONEXISTENT, &simplified, NULL);
 384                                 if (r < 0) {
 385                                         log_warning_errno(r, "Failed to resolve symlink %s pointing to %s, ignoring: %m",
 386                                                           filename, target);
 387                                         continue;
 388                                 }
 389
 390                                 /* Check if the symlink goes outside of our search path.
 391                                  * If yes, it's a linked unit file or mask, and we don't care about the target name.
 392                                  * Let's just store the link source directly.
 393                                  * If not, let's verify that it's a good symlink. */
 394                                 char *tail = path_startswith_strv(simplified, lp->search_path);
 395                                 if (!tail) {
 396                                         log_debug("%s: linked unit file: %s → %s",
 397                                                   __func__, filename, simplified);
 398
 399                                         dst = filename;
 400                                 } else {
 401
 402                                         bool self_alias;
 403
 404                                         dst = basename(simplified);
 405                                         self_alias = streq(dst, de->d_name);
 406
 407                                         if (is_path(tail))
 408                                                 log_full(self_alias ? LOG_DEBUG : LOG_WARNING,
 409                                                          "Suspicious symlink %s→%s, treating as alias.",
 410                                                          filename, simplified);
 411
 412                                         r = unit_validate_alias_symlink_and_warn(filename, simplified);
 413                                         if (r < 0)
 414                                                 continue;
 415
 416                                         if (self_alias) {
 417                                                 /* A self-alias that has no effect */
 418                                                 log_debug("%s: self-alias: %s/%s → %s, ignoring.",
 419                                                           __func__, *dir, de->d_name, dst);
 420                                                 continue;
 421                                         }
 422
 423                                         log_debug("%s: alias: %s/%s → %s", __func__, *dir, de->d_name, dst);
 424                                 }
 425
 426                         } else {
 427                                 dst = filename;
 428                                 log_debug("%s: normal unit file: %s", __func__, dst);
 429                         }
 430
 431                         r = hashmap_put_strdup(&ids, de->d_name, dst);
 432                         if (r < 0)
 433                                 return log_warning_errno(r, "Failed to add entry to hashmap (%s→%s): %m",
 434                                                          de->d_name, dst);
 435                 }
 436         }
 437
 438         /* Let's also put the names in the reverse db. */
 439         const char *dummy, *src;
 440         HASHMAP_FOREACH_KEY(dummy, src, ids) {
 441                 _cleanup_free_ char *inst = NULL, *dst_inst = NULL;
 442                 const char *dst;
 443
 444                 r = unit_ids_map_get(ids, src, &dst);
 445                 if (r < 0)
 446                         continue;
 447
 448                 if (null_or_empty_path(dst) != 0)
 449                         continue;
 450
 451                 dst = basename(dst);
 452
 453                 /* If we have an symlink from an instance name to a template name, it is an alias just for
 454                  * this specific instance, foo@id.service ↔ template@id.service. */
 455                 if (unit_name_is_valid(dst, UNIT_NAME_TEMPLATE)) {
 456                         UnitNameFlags t = unit_name_to_instance(src, &inst);
 457                         if (t < 0)
 458                                 return log_error_errno(t, "Failed to extract instance part from %s: %m", src);
 459                         if (t == UNIT_NAME_INSTANCE) {
 460                                 r = unit_name_replace_instance(dst, inst, &dst_inst);
 461                                 if (r < 0) {
 462                                         /* This might happen e.g. if the combined length is too large.
 463                                          * Let's not make too much of a fuss. */
 464                                         log_debug_errno(r, "Failed to build alias name (%s + %s), ignoring: %m",
 465                                                         dst, inst);
 466                                         continue;
 467                                 }
 468
 469                                 dst = dst_inst;
 470                         }
 471                 }
 472
 473                 r = string_strv_hashmap_put(&names, dst, src);
 474                 if (r < 0)
 475                         return log_warning_errno(r, "Failed to add entry to hashmap (%s→%s): %m", dst, src);
 476         }
 477
 478         if (cache_timestamp_hash)
 479                 *cache_timestamp_hash = timestamp_hash;
 480
 481         hashmap_free_and_replace(*unit_ids_map, ids);
 482         hashmap_free_and_replace(*unit_names_map, names);
 483         if (path_cache)
 484                 set_free_and_replace(*path_cache, paths);
 485
 486         return 1;
 487 }
 488
 489 static int add_name(
 490                 const char *unit_name,
 491                 Set **names,
 492                 const char *name) {
 493         int r;
 494
 495         assert(names);
 496         assert(name);
 497
 498         r = set_put_strdup(names, name);
 499         if (r < 0)
 500                 return r;
 501         if (r > 0 && !streq(unit_name, name))
 502                 log_debug("Unit %s has alias %s.", unit_name, name);
 503         return r;
 504 }
 505
 506 static int add_names(
 507                 Hashmap *unit_ids_map,
 508                 Hashmap *unit_name_map,
 509                 const char *unit_name,
 510                 const char *fragment_basename,  /* Only set when adding additional names based on fragment path */
 511                 UnitNameFlags name_type,
 512                 const char *instance,
 513                 Set **names,
 514                 const char *name) {
 515
 516         char **aliases, **alias;
 517         int r;
 518
 519         assert(name_type == UNIT_NAME_PLAIN || instance);
 520
 521         /* The unit has its own name if it's not a template. If we're looking at a fragment, the fragment
 522          * name (possibly with instance inserted), is also always one of the unit names. */
 523         if (name_type != UNIT_NAME_TEMPLATE) {
 524                 r = add_name(unit_name, names, name);
 525                 if (r < 0)
 526                         return r;
 527         }
 528
 529         /* Add any aliases of the name to the set of names.
 530          *
 531          * We don't even need to know which fragment we will use. The unit_name_map should return the same
 532          * set of names for any of the aliases. */
 533         aliases = hashmap_get(unit_name_map, name);
 534         STRV_FOREACH(alias, aliases) {
 535                 if (name_type == UNIT_NAME_INSTANCE && unit_name_is_valid(*alias, UNIT_NAME_TEMPLATE)) {
 536                         _cleanup_free_ char *inst = NULL;
 537                         const char *inst_fragment = NULL;
 538
 539                         r = unit_name_replace_instance(*alias, instance, &inst);
 540                         if (r < 0)
 541                                 return log_debug_errno(r, "Cannot build instance name %s + %s: %m",
 542                                                        *alias, instance);
 543
 544                         /* Exclude any aliases that point in some other direction.
 545                          *
 546                          * See https://github.com/systemd/systemd/pull/13119#discussion_r308145418. */
 547                         r = unit_ids_map_get(unit_ids_map, inst, &inst_fragment);
 548                         if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO))
 549                                 return log_debug_errno(r, "Cannot find instance fragment %s: %m", inst);
 550
 551                         if (inst_fragment &&
 552                             !streq(basename(inst_fragment), fragment_basename)) {
 553                                 log_debug("Instance %s has fragment %s and is not an alias of %s.",
 554                                           inst, inst_fragment, unit_name);
 555                                 continue;
 556                         }
 557
 558                         r = set_consume(*names, TAKE_PTR(inst));
 559                         if (r > 0)
 560                                 log_debug("Unit %s has alias %s.", unit_name, inst);
 561                 } else
 562                         r = add_name(unit_name, names, *alias);
 563
 564                 if (r < 0)
 565                         return r;
 566         }
 567
 568         return 0;
 569 }
 570
 571 int unit_file_find_fragment(
 572                 Hashmap *unit_ids_map,
 573                 Hashmap *unit_name_map,
 574                 const char *unit_name,
 575                 const char **ret_fragment_path,
 576                 Set **ret_names) {
 577
 578         const char *fragment = NULL;
 579         _cleanup_free_ char *template = NULL, *instance = NULL;
 580         _cleanup_set_free_ Set *names = NULL;
 581         int r;
 582
 583         /* Finds a fragment path, and returns the set of names:
 584          * if we have …/foo.service and …/foo-alias.service→foo.service,
 585          * and …/foo@.service and …/foo-alias@.service→foo@.service,
 586          * and …/foo@inst.service,
 587          * this should return:
 588          * foo.service → …/foo.service, {foo.service, foo-alias.service},
 589          * foo-alias.service → …/foo.service, {foo.service, foo-alias.service},
 590          * foo@.service → …/foo@.service, {foo@.service, foo-alias@.service},
 591          * foo-alias@.service → …/foo@.service, {foo@.service, foo-alias@.service},
 592          * foo@bar.service → …/foo@.service, {foo@bar.service, foo-alias@bar.service},
 593          * foo-alias@bar.service → …/foo@.service, {foo@bar.service, foo-alias@bar.service},
 594          * foo-alias@inst.service → …/foo@inst.service, {foo@inst.service, foo-alias@inst.service}.
 595          */
 596
 597         UnitNameFlags name_type = unit_name_to_instance(unit_name, &instance);
 598         if (name_type < 0)
 599                 return name_type;
 600
 601         r = add_names(unit_ids_map, unit_name_map, unit_name, NULL, name_type, instance, &names, unit_name);
 602         if (r < 0)
 603                 return r;
 604
 605         /* First try to load fragment under the original name */
 606         r = unit_ids_map_get(unit_ids_map, unit_name, &fragment);
 607         if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO))
 608                 return log_debug_errno(r, "Cannot load unit %s: %m", unit_name);
 609
 610         if (!fragment && name_type == UNIT_NAME_INSTANCE) {
 611                 /* Look for a fragment under the template name */
 612
 613                 r = unit_name_template(unit_name, &template);
 614                 if (r < 0)
 615                         return log_debug_errno(r, "Failed to determine template name: %m");
 616
 617                 r = unit_ids_map_get(unit_ids_map, template, &fragment);
 618                 if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO))
 619                         return log_debug_errno(r, "Cannot load template %s: %m", template);
 620         }
 621
 622         if (fragment) {
 623                 const char *fragment_basename = basename(fragment);
 624
 625                 if (!streq(fragment_basename, unit_name)) {
 626                         /* Add names based on the fragment name to the set of names */
 627                         r = add_names(unit_ids_map, unit_name_map, unit_name, fragment_basename, name_type, instance, &names, fragment_basename);
 628                         if (r < 0)
 629                                 return r;
 630                 }
 631         }
 632
 633         *ret_fragment_path = fragment;
 634         *ret_names = TAKE_PTR(names);
 635
 636         return 0;
 637 }
 638
 639 static const char * const rlmap[] = {
 640         "emergency", SPECIAL_EMERGENCY_TARGET,
 641         "-b",        SPECIAL_EMERGENCY_TARGET,
 642         "rescue",    SPECIAL_RESCUE_TARGET,
 643         "single",    SPECIAL_RESCUE_TARGET,
 644         "-s",        SPECIAL_RESCUE_TARGET,
 645         "s",         SPECIAL_RESCUE_TARGET,
 646         "S",         SPECIAL_RESCUE_TARGET,
 647         "1",         SPECIAL_RESCUE_TARGET,
 648         "2",         SPECIAL_MULTI_USER_TARGET,
 649         "3",         SPECIAL_MULTI_USER_TARGET,
 650         "4",         SPECIAL_MULTI_USER_TARGET,
 651         "5",         SPECIAL_GRAPHICAL_TARGET,
 652         NULL
 653 };
 654
 655 static const char * const rlmap_initrd[] = {
 656         "emergency", SPECIAL_EMERGENCY_TARGET,
 657         "rescue",    SPECIAL_RESCUE_TARGET,
 658         NULL
 659 };
 660
 661 const char* runlevel_to_target(const char *word) {
 662         const char * const *rlmap_ptr;
 663
 664         if (!word)
 665                 return NULL;
 666
 667         if (in_initrd()) {
 668                 word = startswith(word, "rd.");
 669                 if (!word)
 670                         return NULL;
 671         }
 672
 673         rlmap_ptr = in_initrd() ? rlmap_initrd : rlmap;
 674
 675         for (size_t i = 0; rlmap_ptr[i]; i += 2)
 676                 if (streq(word, rlmap_ptr[i]))
 677                         return rlmap_ptr[i+1];
 678
 679         return NULL;
 680 }