src/basic/unit-file.c

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