src/unit.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/epoll.h>
  26 #include <sys/timerfd.h>
  27 #include <sys/poll.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <sys/stat.h>
  31
  32 #include "set.h"
  33 #include "unit.h"
  34 #include "macro.h"
  35 #include "strv.h"
  36 #include "load-fragment.h"
  37 #include "load-dropin.h"
  38 #include "log.h"
  39 #include "unit-name.h"
  40 #include "specifier.h"
  41 #include "dbus-unit.h"
  42 #include "special.h"
  43 #include "cgroup-util.h"
  44 #include "missing.h"
  45
  46 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
  47         [UNIT_SERVICE] = &service_vtable,
  48         [UNIT_TIMER] = &timer_vtable,
  49         [UNIT_SOCKET] = &socket_vtable,
  50         [UNIT_TARGET] = &target_vtable,
  51         [UNIT_DEVICE] = &device_vtable,
  52         [UNIT_MOUNT] = &mount_vtable,
  53         [UNIT_AUTOMOUNT] = &automount_vtable,
  54         [UNIT_SNAPSHOT] = &snapshot_vtable,
  55         [UNIT_SWAP] = &swap_vtable,
  56         [UNIT_PATH] = &path_vtable
  57 };
  58
  59 Unit *unit_new(Manager *m) {
  60         Unit *u;
  61
  62         assert(m);
  63
  64         if (!(u = new0(Unit, 1)))
  65                 return NULL;
  66
  67         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
  68                 free(u);
  69                 return NULL;
  70         }
  71
  72         u->meta.manager = m;
  73         u->meta.type = _UNIT_TYPE_INVALID;
  74         u->meta.deserialized_job = _JOB_TYPE_INVALID;
  75         u->meta.default_dependencies = true;
  76
  77         return u;
  78 }
  79
  80 bool unit_has_name(Unit *u, const char *name) {
  81         assert(u);
  82         assert(name);
  83
  84         return !!set_get(u->meta.names, (char*) name);
  85 }
  86
  87 int unit_add_name(Unit *u, const char *text) {
  88         UnitType t;
  89         char *s, *i = NULL;
  90         int r;
  91
  92         assert(u);
  93         assert(text);
  94
  95         if (unit_name_is_template(text)) {
  96                 if (!u->meta.instance)
  97                         return -EINVAL;
  98
  99                 s = unit_name_replace_instance(text, u->meta.instance);
 100         } else
 101                 s = strdup(text);
 102
 103         if (!s)
 104                 return -ENOMEM;
 105
 106         if (!unit_name_is_valid(s)) {
 107                 r = -EINVAL;
 108                 goto fail;
 109         }
 110
 111         assert_se((t = unit_name_to_type(s)) >= 0);
 112
 113         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
 114                 r = -EINVAL;
 115                 goto fail;
 116         }
 117
 118         if ((r = unit_name_to_instance(s, &i)) < 0)
 119                 goto fail;
 120
 121         if (i && unit_vtable[t]->no_instances)
 122                 goto fail;
 123
 124         /* Ensure that this unit is either instanced or not instanced,
 125          * but not both. */
 126         if (u->meta.type != _UNIT_TYPE_INVALID && !u->meta.instance != !i) {
 127                 r = -EINVAL;
 128                 goto fail;
 129         }
 130
 131         if (unit_vtable[t]->no_alias &&
 132             !set_isempty(u->meta.names) &&
 133             !set_get(u->meta.names, s)) {
 134                 r = -EEXIST;
 135                 goto fail;
 136         }
 137
 138         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
 139                 r = -E2BIG;
 140                 goto fail;
 141         }
 142
 143         if ((r = set_put(u->meta.names, s)) < 0) {
 144                 if (r == -EEXIST)
 145                         r = 0;
 146                 goto fail;
 147         }
 148
 149         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 150                 set_remove(u->meta.names, s);
 151                 goto fail;
 152         }
 153
 154         if (u->meta.type == _UNIT_TYPE_INVALID) {
 155
 156                 u->meta.type = t;
 157                 u->meta.id = s;
 158                 u->meta.instance = i;
 159
 160                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 161
 162                 if (UNIT_VTABLE(u)->init)
 163                         UNIT_VTABLE(u)->init(u);
 164         } else
 165                 free(i);
 166
 167         unit_add_to_dbus_queue(u);
 168         return 0;
 169
 170 fail:
 171         free(s);
 172         free(i);
 173
 174         return r;
 175 }
 176
 177 int unit_choose_id(Unit *u, const char *name) {
 178         char *s, *t = NULL, *i;
 179         int r;
 180
 181         assert(u);
 182         assert(name);
 183
 184         if (unit_name_is_template(name)) {
 185
 186                 if (!u->meta.instance)
 187                         return -EINVAL;
 188
 189                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
 190                         return -ENOMEM;
 191
 192                 name = t;
 193         }
 194
 195         /* Selects one of the names of this unit as the id */
 196         s = set_get(u->meta.names, (char*) name);
 197         free(t);
 198
 199         if (!s)
 200                 return -ENOENT;
 201
 202         if ((r = unit_name_to_instance(s, &i)) < 0)
 203                 return r;
 204
 205         u->meta.id = s;
 206
 207         free(u->meta.instance);
 208         u->meta.instance = i;
 209
 210         unit_add_to_dbus_queue(u);
 211
 212         return 0;
 213 }
 214
 215 int unit_set_description(Unit *u, const char *description) {
 216         char *s;
 217
 218         assert(u);
 219
 220         if (!(s = strdup(description)))
 221                 return -ENOMEM;
 222
 223         free(u->meta.description);
 224         u->meta.description = s;
 225
 226         unit_add_to_dbus_queue(u);
 227         return 0;
 228 }
 229
 230 bool unit_check_gc(Unit *u) {
 231         assert(u);
 232
 233         if (u->meta.load_state == UNIT_STUB)
 234                 return true;
 235
 236         if (UNIT_VTABLE(u)->no_gc)
 237                 return true;
 238
 239         if (u->meta.no_gc)
 240                 return true;
 241
 242         if (u->meta.job)
 243                 return true;
 244
 245         if (unit_active_state(u) != UNIT_INACTIVE)
 246                 return true;
 247
 248         if (UNIT_VTABLE(u)->check_gc)
 249                 if (UNIT_VTABLE(u)->check_gc(u))
 250                         return true;
 251
 252         return false;
 253 }
 254
 255 void unit_add_to_load_queue(Unit *u) {
 256         assert(u);
 257         assert(u->meta.type != _UNIT_TYPE_INVALID);
 258
 259         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 260                 return;
 261
 262         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 263         u->meta.in_load_queue = true;
 264 }
 265
 266 void unit_add_to_cleanup_queue(Unit *u) {
 267         assert(u);
 268
 269         if (u->meta.in_cleanup_queue)
 270                 return;
 271
 272         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 273         u->meta.in_cleanup_queue = true;
 274 }
 275
 276 void unit_add_to_gc_queue(Unit *u) {
 277         assert(u);
 278
 279         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 280                 return;
 281
 282         if (unit_check_gc(u))
 283                 return;
 284
 285         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 286         u->meta.in_gc_queue = true;
 287
 288         u->meta.manager->n_in_gc_queue ++;
 289
 290         if (u->meta.manager->gc_queue_timestamp <= 0)
 291                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 292 }
 293
 294 void unit_add_to_dbus_queue(Unit *u) {
 295         assert(u);
 296         assert(u->meta.type != _UNIT_TYPE_INVALID);
 297
 298         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue)
 299                 return;
 300
 301         /* Shortcut things if nobody cares */
 302         if (!bus_has_subscriber(u->meta.manager)) {
 303                 u->meta.sent_dbus_new_signal = true;
 304                 return;
 305         }
 306
 307         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 308         u->meta.in_dbus_queue = true;
 309 }
 310
 311 static void bidi_set_free(Unit *u, Set *s) {
 312         Iterator i;
 313         Unit *other;
 314
 315         assert(u);
 316
 317         /* Frees the set and makes sure we are dropped from the
 318          * inverse pointers */
 319
 320         SET_FOREACH(other, s, i) {
 321                 UnitDependency d;
 322
 323                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 324                         set_remove(other->meta.dependencies[d], u);
 325
 326                 unit_add_to_gc_queue(other);
 327         }
 328
 329         set_free(s);
 330 }
 331
 332 void unit_free(Unit *u) {
 333         UnitDependency d;
 334         Iterator i;
 335         char *t;
 336
 337         assert(u);
 338
 339         bus_unit_send_removed_signal(u);
 340
 341         if (u->meta.load_state != UNIT_STUB)
 342                 if (UNIT_VTABLE(u)->done)
 343                         UNIT_VTABLE(u)->done(u);
 344
 345         SET_FOREACH(t, u->meta.names, i)
 346                 hashmap_remove_value(u->meta.manager->units, t, u);
 347
 348         if (u->meta.job)
 349                 job_free(u->meta.job);
 350
 351         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 352                 bidi_set_free(u, u->meta.dependencies[d]);
 353
 354         if (u->meta.type != _UNIT_TYPE_INVALID)
 355                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 356
 357         if (u->meta.in_load_queue)
 358                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 359
 360         if (u->meta.in_dbus_queue)
 361                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 362
 363         if (u->meta.in_cleanup_queue)
 364                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 365
 366         if (u->meta.in_gc_queue) {
 367                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 368                 u->meta.manager->n_in_gc_queue--;
 369         }
 370
 371         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 372
 373         free(u->meta.description);
 374         free(u->meta.fragment_path);
 375
 376         set_free_free(u->meta.names);
 377
 378         free(u->meta.instance);
 379
 380         free(u);
 381 }
 382
 383 UnitActiveState unit_active_state(Unit *u) {
 384         assert(u);
 385
 386         if (u->meta.load_state == UNIT_MERGED)
 387                 return unit_active_state(unit_follow_merge(u));
 388
 389         /* After a reload it might happen that a unit is not correctly
 390          * loaded but still has a process around. That's why we won't
 391          * shortcut failed loading to UNIT_INACTIVE_MAINTENANCE. */
 392
 393         return UNIT_VTABLE(u)->active_state(u);
 394 }
 395
 396 const char* unit_sub_state_to_string(Unit *u) {
 397         assert(u);
 398
 399         return UNIT_VTABLE(u)->sub_state_to_string(u);
 400 }
 401
 402 static void complete_move(Set **s, Set **other) {
 403         assert(s);
 404         assert(other);
 405
 406         if (!*other)
 407                 return;
 408
 409         if (*s)
 410                 set_move(*s, *other);
 411         else {
 412                 *s = *other;
 413                 *other = NULL;
 414         }
 415 }
 416
 417 static void merge_names(Unit *u, Unit *other) {
 418         char *t;
 419         Iterator i;
 420
 421         assert(u);
 422         assert(other);
 423
 424         complete_move(&u->meta.names, &other->meta.names);
 425
 426         set_free_free(other->meta.names);
 427         other->meta.names = NULL;
 428         other->meta.id = NULL;
 429
 430         SET_FOREACH(t, u->meta.names, i)
 431                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
 432 }
 433
 434 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
 435         Iterator i;
 436         Unit *back;
 437         int r;
 438
 439         assert(u);
 440         assert(other);
 441         assert(d < _UNIT_DEPENDENCY_MAX);
 442
 443         SET_FOREACH(back, other->meta.dependencies[d], i) {
 444                 UnitDependency k;
 445
 446                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
 447                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
 448
 449                                 if (r == -EEXIST)
 450                                         set_remove(back->meta.dependencies[k], other);
 451                                 else
 452                                         assert(r == -ENOENT);
 453                         }
 454         }
 455
 456         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
 457
 458         set_free(other->meta.dependencies[d]);
 459         other->meta.dependencies[d] = NULL;
 460 }
 461
 462 int unit_merge(Unit *u, Unit *other) {
 463         UnitDependency d;
 464
 465         assert(u);
 466         assert(other);
 467         assert(u->meta.manager == other->meta.manager);
 468         assert(u->meta.type != _UNIT_TYPE_INVALID);
 469
 470         other = unit_follow_merge(other);
 471
 472         if (other == u)
 473                 return 0;
 474
 475         if (u->meta.type != other->meta.type)
 476                 return -EINVAL;
 477
 478         if (!u->meta.instance != !other->meta.instance)
 479                 return -EINVAL;
 480
 481         if (other->meta.load_state != UNIT_STUB &&
 482             other->meta.load_state != UNIT_FAILED)
 483                 return -EEXIST;
 484
 485         if (other->meta.job)
 486                 return -EEXIST;
 487
 488         if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(other)))
 489                 return -EEXIST;
 490
 491         /* Merge names */
 492         merge_names(u, other);
 493
 494         /* Merge dependencies */
 495         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 496                 merge_dependencies(u, other, d);
 497
 498         other->meta.load_state = UNIT_MERGED;
 499         other->meta.merged_into = u;
 500
 501         /* If there is still some data attached to the other node, we
 502          * don't need it anymore, and can free it. */
 503         if (other->meta.load_state != UNIT_STUB)
 504                 if (UNIT_VTABLE(other)->done)
 505                         UNIT_VTABLE(other)->done(other);
 506
 507         unit_add_to_dbus_queue(u);
 508         unit_add_to_cleanup_queue(other);
 509
 510         return 0;
 511 }
 512
 513 int unit_merge_by_name(Unit *u, const char *name) {
 514         Unit *other;
 515         int r;
 516         char *s = NULL;
 517
 518         assert(u);
 519         assert(name);
 520
 521         if (unit_name_is_template(name)) {
 522                 if (!u->meta.instance)
 523                         return -EINVAL;
 524
 525                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
 526                         return -ENOMEM;
 527
 528                 name = s;
 529         }
 530
 531         if (!(other = manager_get_unit(u->meta.manager, name)))
 532                 r = unit_add_name(u, name);
 533         else
 534                 r = unit_merge(u, other);
 535
 536         free(s);
 537         return r;
 538 }
 539
 540 Unit* unit_follow_merge(Unit *u) {
 541         assert(u);
 542
 543         while (u->meta.load_state == UNIT_MERGED)
 544                 assert_se(u = u->meta.merged_into);
 545
 546         return u;
 547 }
 548
 549 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 550         int r;
 551
 552         assert(u);
 553         assert(c);
 554
 555         if (c->std_output != EXEC_OUTPUT_KMSG &&
 556             c->std_output != EXEC_OUTPUT_SYSLOG &&
 557             c->std_error != EXEC_OUTPUT_KMSG &&
 558             c->std_error != EXEC_OUTPUT_SYSLOG)
 559                 return 0;
 560
 561         /* If syslog or kernel logging is requested, make sure our own
 562          * logging daemon is run first. */
 563
 564         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 565                 return r;
 566
 567         if (u->meta.manager->running_as == MANAGER_SYSTEM)
 568                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 569                         return r;
 570
 571         return 0;
 572 }
 573
 574 const char *unit_description(Unit *u) {
 575         assert(u);
 576
 577         if (u->meta.description)
 578                 return u->meta.description;
 579
 580         return u->meta.id;
 581 }
 582
 583 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 584         char *t;
 585         UnitDependency d;
 586         Iterator i;
 587         char *p2;
 588         const char *prefix2;
 589         CGroupBonding *b;
 590         char
 591                 timestamp1[FORMAT_TIMESTAMP_MAX],
 592                 timestamp2[FORMAT_TIMESTAMP_MAX],
 593                 timestamp3[FORMAT_TIMESTAMP_MAX],
 594                 timestamp4[FORMAT_TIMESTAMP_MAX],
 595                 timespan[FORMAT_TIMESPAN_MAX];
 596         Unit *following;
 597
 598         assert(u);
 599         assert(u->meta.type >= 0);
 600
 601         if (!prefix)
 602                 prefix = "";
 603         p2 = strappend(prefix, "\t");
 604         prefix2 = p2 ? p2 : prefix;
 605
 606         fprintf(f,
 607                 "%s-> Unit %s:\n"
 608                 "%s\tDescription: %s\n"
 609                 "%s\tInstance: %s\n"
 610                 "%s\tUnit Load State: %s\n"
 611                 "%s\tUnit Active State: %s\n"
 612                 "%s\tInactive Exit Timestamp: %s\n"
 613                 "%s\tActive Enter Timestamp: %s\n"
 614                 "%s\tActive Exit Timestamp: %s\n"
 615                 "%s\tInactive Enter Timestamp: %s\n"
 616                 "%s\tGC Check Good: %s\n"
 617                 "%s\tNeed Daemon Reload: %s\n",
 618                 prefix, u->meta.id,
 619                 prefix, unit_description(u),
 620                 prefix, strna(u->meta.instance),
 621                 prefix, unit_load_state_to_string(u->meta.load_state),
 622                 prefix, unit_active_state_to_string(unit_active_state(u)),
 623                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.inactive_exit_timestamp.realtime)),
 624                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_enter_timestamp.realtime)),
 625                 prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->meta.active_exit_timestamp.realtime)),
 626                 prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->meta.inactive_enter_timestamp.realtime)),
 627                 prefix, yes_no(unit_check_gc(u)),
 628                 prefix, yes_no(unit_need_daemon_reload(u)));
 629
 630         SET_FOREACH(t, u->meta.names, i)
 631                 fprintf(f, "%s\tName: %s\n", prefix, t);
 632
 633         if ((following = unit_following(u)))
 634                 fprintf(f, "%s\tFollowing: %s\n", prefix, following->meta.id);
 635
 636         if (u->meta.fragment_path)
 637                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
 638
 639         if (u->meta.job_timeout > 0)
 640                 fprintf(f, "%s\tJob Timeout: %s\n", prefix, format_timespan(timespan, sizeof(timespan), u->meta.job_timeout));
 641
 642         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 643                 Unit *other;
 644
 645                 SET_FOREACH(other, u->meta.dependencies[d], i)
 646                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
 647         }
 648
 649         if (u->meta.load_state == UNIT_LOADED) {
 650                 fprintf(f,
 651                         "%s\tRecursive Stop: %s\n"
 652                         "%s\tStopWhenUnneeded: %s\n"
 653                         "%s\tRefuseManualStart: %s\n"
 654                         "%s\tRefuseManualStop: %s\n"
 655                         "%s\tDefaultDependencies: %s\n"
 656                         "%s\tIgnoreDependencyFailure: %s\n",
 657                         prefix, yes_no(u->meta.recursive_stop),
 658                         prefix, yes_no(u->meta.stop_when_unneeded),
 659                         prefix, yes_no(u->meta.refuse_manual_start),
 660                         prefix, yes_no(u->meta.refuse_manual_stop),
 661                         prefix, yes_no(u->meta.default_dependencies),
 662                         prefix, yes_no(u->meta.ignore_dependency_failure));
 663
 664                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
 665                         fprintf(f, "%s\tControlGroup: %s:%s\n",
 666                                 prefix, b->controller, b->path);
 667
 668                 if (UNIT_VTABLE(u)->dump)
 669                         UNIT_VTABLE(u)->dump(u, f, prefix2);
 670
 671         } else if (u->meta.load_state == UNIT_MERGED)
 672                 fprintf(f,
 673                         "%s\tMerged into: %s\n",
 674                         prefix, u->meta.merged_into->meta.id);
 675         else if (u->meta.load_state == UNIT_FAILED)
 676                 fprintf(f, "%s\tLoad Error Code: %s\n", prefix, strerror(-u->meta.load_error));
 677
 678
 679         if (u->meta.job)
 680                 job_dump(u->meta.job, f, prefix2);
 681
 682         free(p2);
 683 }
 684
 685 /* Common implementation for multiple backends */
 686 int unit_load_fragment_and_dropin(Unit *u) {
 687         int r;
 688
 689         assert(u);
 690
 691         /* Load a .service file */
 692         if ((r = unit_load_fragment(u)) < 0)
 693                 return r;
 694
 695         if (u->meta.load_state == UNIT_STUB)
 696                 return -ENOENT;
 697
 698         /* Load drop-in directory data */
 699         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 700                 return r;
 701
 702         return 0;
 703 }
 704
 705 /* Common implementation for multiple backends */
 706 int unit_load_fragment_and_dropin_optional(Unit *u) {
 707         int r;
 708
 709         assert(u);
 710
 711         /* Same as unit_load_fragment_and_dropin(), but whether
 712          * something can be loaded or not doesn't matter. */
 713
 714         /* Load a .service file */
 715         if ((r = unit_load_fragment(u)) < 0)
 716                 return r;
 717
 718         if (u->meta.load_state == UNIT_STUB)
 719                 u->meta.load_state = UNIT_LOADED;
 720
 721         /* Load drop-in directory data */
 722         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 723                 return r;
 724
 725         return 0;
 726 }
 727
 728 int unit_load(Unit *u) {
 729         int r;
 730
 731         assert(u);
 732
 733         if (u->meta.in_load_queue) {
 734                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 735                 u->meta.in_load_queue = false;
 736         }
 737
 738         if (u->meta.type == _UNIT_TYPE_INVALID)
 739                 return -EINVAL;
 740
 741         if (u->meta.load_state != UNIT_STUB)
 742                 return 0;
 743
 744         if (UNIT_VTABLE(u)->load)
 745                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
 746                         goto fail;
 747
 748         if (u->meta.load_state == UNIT_STUB) {
 749                 r = -ENOENT;
 750                 goto fail;
 751         }
 752
 753         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
 754
 755         unit_add_to_dbus_queue(unit_follow_merge(u));
 756         unit_add_to_gc_queue(u);
 757
 758         return 0;
 759
 760 fail:
 761         u->meta.load_state = UNIT_FAILED;
 762         u->meta.load_error = r;
 763         unit_add_to_dbus_queue(u);
 764
 765         log_debug("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
 766
 767         return r;
 768 }
 769
 770 /* Errors:
 771  *         -EBADR:     This unit type does not support starting.
 772  *         -EALREADY:  Unit is already started.
 773  *         -EAGAIN:    An operation is already in progress. Retry later.
 774  *         -ECANCELED: Too many requests for now.
 775  */
 776 int unit_start(Unit *u) {
 777         UnitActiveState state;
 778
 779         assert(u);
 780
 781         if (u->meta.load_state != UNIT_LOADED)
 782                 return -EINVAL;
 783
 784         /* If this is already (being) started, then this will
 785          * succeed. Note that this will even succeed if this unit is
 786          * not startable by the user. This is relied on to detect when
 787          * we need to wait for units and when waiting is finished. */
 788         state = unit_active_state(u);
 789         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 790                 return -EALREADY;
 791
 792         /* If it is stopped, but we cannot start it, then fail */
 793         if (!UNIT_VTABLE(u)->start)
 794                 return -EBADR;
 795
 796         /* We don't suppress calls to ->start() here when we are
 797          * already starting, to allow this request to be used as a
 798          * "hurry up" call, for example when the unit is in some "auto
 799          * restart" state where it waits for a holdoff timer to elapse
 800          * before it will start again. */
 801
 802         unit_add_to_dbus_queue(u);
 803
 804         unit_status_printf(u, "Starting %s...\n", unit_description(u));
 805
 806         return UNIT_VTABLE(u)->start(u);
 807 }
 808
 809 bool unit_can_start(Unit *u) {
 810         assert(u);
 811
 812         return !!UNIT_VTABLE(u)->start;
 813 }
 814
 815 /* Errors:
 816  *         -EBADR:    This unit type does not support stopping.
 817  *         -EALREADY: Unit is already stopped.
 818  *         -EAGAIN:   An operation is already in progress. Retry later.
 819  */
 820 int unit_stop(Unit *u) {
 821         UnitActiveState state;
 822
 823         assert(u);
 824
 825         state = unit_active_state(u);
 826         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(state))
 827                 return -EALREADY;
 828
 829         if (!UNIT_VTABLE(u)->stop)
 830                 return -EBADR;
 831
 832         unit_add_to_dbus_queue(u);
 833
 834         unit_status_printf(u, "Stopping %s...\n", unit_description(u));
 835
 836         return UNIT_VTABLE(u)->stop(u);
 837 }
 838
 839 /* Errors:
 840  *         -EBADR:    This unit type does not support reloading.
 841  *         -ENOEXEC:  Unit is not started.
 842  *         -EAGAIN:   An operation is already in progress. Retry later.
 843  */
 844 int unit_reload(Unit *u) {
 845         UnitActiveState state;
 846
 847         assert(u);
 848
 849         if (u->meta.load_state != UNIT_LOADED)
 850                 return -EINVAL;
 851
 852         if (!unit_can_reload(u))
 853                 return -EBADR;
 854
 855         state = unit_active_state(u);
 856         if (state == UNIT_RELOADING)
 857                 return -EALREADY;
 858
 859         if (state != UNIT_ACTIVE)
 860                 return -ENOEXEC;
 861
 862         unit_add_to_dbus_queue(u);
 863         return UNIT_VTABLE(u)->reload(u);
 864 }
 865
 866 bool unit_can_reload(Unit *u) {
 867         assert(u);
 868
 869         if (!UNIT_VTABLE(u)->reload)
 870                 return false;
 871
 872         if (!UNIT_VTABLE(u)->can_reload)
 873                 return true;
 874
 875         return UNIT_VTABLE(u)->can_reload(u);
 876 }
 877
 878 static void unit_check_uneeded(Unit *u) {
 879         Iterator i;
 880         Unit *other;
 881
 882         assert(u);
 883
 884         /* If this service shall be shut down when unneeded then do
 885          * so. */
 886
 887         if (!u->meta.stop_when_unneeded)
 888                 return;
 889
 890         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 891                 return;
 892
 893         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 894                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 895                         return;
 896
 897         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 898                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 899                         return;
 900
 901         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 902                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 903                         return;
 904
 905         log_info("Service %s is not needed anymore. Stopping.", u->meta.id);
 906
 907         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 908         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL, NULL);
 909 }
 910
 911 static void retroactively_start_dependencies(Unit *u) {
 912         Iterator i;
 913         Unit *other;
 914
 915         assert(u);
 916         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 917
 918         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 919                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 920                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
 921
 922         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 923                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 924                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
 925
 926         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 927                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 928                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
 929
 930         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 931                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 932                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
 933
 934         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 935                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 936                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
 937
 938         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTED_BY], i)
 939                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 940                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
 941 }
 942
 943 static void retroactively_stop_dependencies(Unit *u) {
 944         Iterator i;
 945         Unit *other;
 946
 947         assert(u);
 948         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 949
 950         if (u->meta.recursive_stop) {
 951                 /* Pull down units need us recursively if enabled */
 952                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 953                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 954                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
 955         }
 956
 957         /* Garbage collect services that might not be needed anymore, if enabled */
 958         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 959                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 960                         unit_check_uneeded(other);
 961         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 962                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 963                         unit_check_uneeded(other);
 964         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 965                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 966                         unit_check_uneeded(other);
 967         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 968                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 969                         unit_check_uneeded(other);
 970         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
 971                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 972                         unit_check_uneeded(other);
 973 }
 974
 975 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 976         dual_timestamp ts;
 977         bool unexpected;
 978
 979         assert(u);
 980         assert(os < _UNIT_ACTIVE_STATE_MAX);
 981         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 982
 983         /* Note that this is called for all low-level state changes,
 984          * even if they might map to the same high-level
 985          * UnitActiveState! That means that ns == os is OK an expected
 986          * behaviour here. For example: if a mount point is remounted
 987          * this function will be called too! */
 988
 989         dual_timestamp_get(&ts);
 990
 991         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && !UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 992                 u->meta.inactive_exit_timestamp = ts;
 993         else if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 994                 u->meta.inactive_enter_timestamp = ts;
 995
 996         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 997                 u->meta.active_enter_timestamp = ts;
 998         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 999                 u->meta.active_exit_timestamp = ts;
1000
1001         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
1002                 cgroup_bonding_trim_list(u->meta.cgroup_bondings, true);
1003
1004         timer_unit_notify(u, ns);
1005         path_unit_notify(u, ns);
1006
1007         if (u->meta.job) {
1008                 unexpected = false;
1009
1010                 if (u->meta.job->state == JOB_WAITING)
1011
1012                         /* So we reached a different state for this
1013                          * job. Let's see if we can run it now if it
1014                          * failed previously due to EAGAIN. */
1015                         job_add_to_run_queue(u->meta.job);
1016
1017                 /* Let's check whether this state change constitutes a
1018                  * finished job, or maybe cotradicts a running job and
1019                  * hence needs to invalidate jobs. */
1020
1021                 switch (u->meta.job->type) {
1022
1023                 case JOB_START:
1024                 case JOB_VERIFY_ACTIVE:
1025
1026                         if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
1027                                 job_finish_and_invalidate(u->meta.job, true);
1028                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
1029                                 unexpected = true;
1030
1031                                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
1032                                         job_finish_and_invalidate(u->meta.job, ns != UNIT_MAINTENANCE);
1033                         }
1034
1035                         break;
1036
1037                 case JOB_RELOAD:
1038                 case JOB_RELOAD_OR_START:
1039
1040                         if (u->meta.job->state == JOB_RUNNING) {
1041                                 if (ns == UNIT_ACTIVE)
1042                                         job_finish_and_invalidate(u->meta.job, true);
1043                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_RELOADING) {
1044                                         unexpected = true;
1045
1046                                         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
1047                                                 job_finish_and_invalidate(u->meta.job, ns != UNIT_MAINTENANCE);
1048                                 }
1049                         }
1050
1051                         break;
1052
1053                 case JOB_STOP:
1054                 case JOB_RESTART:
1055                 case JOB_TRY_RESTART:
1056
1057                         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
1058                                 job_finish_and_invalidate(u->meta.job, true);
1059                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
1060                                 unexpected = true;
1061                                 job_finish_and_invalidate(u->meta.job, false);
1062                         }
1063
1064                         break;
1065
1066                 default:
1067                         assert_not_reached("Job type unknown");
1068                 }
1069
1070         } else
1071                 unexpected = true;
1072
1073         /* If this state change happened without being requested by a
1074          * job, then let's retroactively start or stop
1075          * dependencies. We skip that step when deserializing, since
1076          * we don't want to create any additional jobs just because
1077          * something is already activated. */
1078
1079         if (unexpected && u->meta.manager->n_deserializing <= 0) {
1080                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1081                         retroactively_start_dependencies(u);
1082                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1083                         retroactively_stop_dependencies(u);
1084         }
1085
1086         if (ns != os && ns == UNIT_MAINTENANCE) {
1087                 Iterator i;
1088                 Unit *other;
1089
1090                 SET_FOREACH(other, u->meta.dependencies[UNIT_ON_FAILURE], i)
1091                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
1092
1093                 log_notice("Unit %s entered maintenance state.", u->meta.id);
1094         }
1095
1096         /* Some names are special */
1097         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1098                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE))
1099                         /* The bus just might have become available,
1100                          * hence try to connect to it, if we aren't
1101                          * yet connected. */
1102                         bus_init(u->meta.manager);
1103
1104                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1105                         /* The syslog daemon just might have become
1106                          * available, hence try to connect to it, if
1107                          * we aren't yet connected. */
1108                         log_open();
1109
1110                 if (u->meta.type == UNIT_SERVICE &&
1111                     !UNIT_IS_ACTIVE_OR_RELOADING(os)) {
1112                         /* Write audit record if we have just finished starting up */
1113                         manager_send_unit_audit(u->meta.manager, u, AUDIT_SERVICE_START, 1);
1114                         u->meta.in_audit = true;
1115                 }
1116
1117         } else {
1118
1119                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1120                         /* The syslog daemon might just have
1121                          * terminated, hence try to disconnect from
1122                          * it. */
1123                         log_close_syslog();
1124
1125                 /* We don't care about D-Bus here, since we'll get an
1126                  * asynchronous notification for it anyway. */
1127
1128                 if (u->meta.type == UNIT_SERVICE &&
1129                     UNIT_IS_INACTIVE_OR_MAINTENANCE(ns) &&
1130                     !UNIT_IS_INACTIVE_OR_MAINTENANCE(os)) {
1131
1132                         /* Hmm, if there was no start record written
1133                          * write it now, so that we always have a nice
1134                          * pair */
1135                         if (!u->meta.in_audit) {
1136                                 manager_send_unit_audit(u->meta.manager, u, AUDIT_SERVICE_START, ns == UNIT_INACTIVE);
1137
1138                                 if (ns == UNIT_INACTIVE)
1139                                         manager_send_unit_audit(u->meta.manager, u, AUDIT_SERVICE_STOP, true);
1140                         } else
1141                                 /* Write audit record if we have just finished shutting down */
1142                                 manager_send_unit_audit(u->meta.manager, u, AUDIT_SERVICE_STOP, ns == UNIT_INACTIVE);
1143
1144                         u->meta.in_audit = false;
1145                 }
1146         }
1147
1148         /* Maybe we finished startup and are now ready for being
1149          * stopped because unneeded? */
1150         unit_check_uneeded(u);
1151
1152         unit_add_to_dbus_queue(u);
1153         unit_add_to_gc_queue(u);
1154 }
1155
1156 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1157         struct epoll_event ev;
1158
1159         assert(u);
1160         assert(fd >= 0);
1161         assert(w);
1162         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1163
1164         zero(ev);
1165         ev.data.ptr = w;
1166         ev.events = events;
1167
1168         if (epoll_ctl(u->meta.manager->epoll_fd,
1169                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1170                       fd,
1171                       &ev) < 0)
1172                 return -errno;
1173
1174         w->fd = fd;
1175         w->type = WATCH_FD;
1176         w->data.unit = u;
1177
1178         return 0;
1179 }
1180
1181 void unit_unwatch_fd(Unit *u, Watch *w) {
1182         assert(u);
1183         assert(w);
1184
1185         if (w->type == WATCH_INVALID)
1186                 return;
1187
1188         assert(w->type == WATCH_FD);
1189         assert(w->data.unit == u);
1190         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1191
1192         w->fd = -1;
1193         w->type = WATCH_INVALID;
1194         w->data.unit = NULL;
1195 }
1196
1197 int unit_watch_pid(Unit *u, pid_t pid) {
1198         assert(u);
1199         assert(pid >= 1);
1200
1201         /* Watch a specific PID. We only support one unit watching
1202          * each PID for now. */
1203
1204         return hashmap_put(u->meta.manager->watch_pids, LONG_TO_PTR(pid), u);
1205 }
1206
1207 void unit_unwatch_pid(Unit *u, pid_t pid) {
1208         assert(u);
1209         assert(pid >= 1);
1210
1211         hashmap_remove_value(u->meta.manager->watch_pids, LONG_TO_PTR(pid), u);
1212 }
1213
1214 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1215         struct itimerspec its;
1216         int flags, fd;
1217         bool ours;
1218
1219         assert(u);
1220         assert(w);
1221         assert(w->type == WATCH_INVALID || (w->type == WATCH_UNIT_TIMER && w->data.unit == u));
1222
1223         /* This will try to reuse the old timer if there is one */
1224
1225         if (w->type == WATCH_UNIT_TIMER) {
1226                 assert(w->data.unit == u);
1227                 assert(w->fd >= 0);
1228
1229                 ours = false;
1230                 fd = w->fd;
1231         } else if (w->type == WATCH_INVALID) {
1232
1233                 ours = true;
1234                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1235                         return -errno;
1236         } else
1237                 assert_not_reached("Invalid watch type");
1238
1239         zero(its);
1240
1241         if (delay <= 0) {
1242                 /* Set absolute time in the past, but not 0, since we
1243                  * don't want to disarm the timer */
1244                 its.it_value.tv_sec = 0;
1245                 its.it_value.tv_nsec = 1;
1246
1247                 flags = TFD_TIMER_ABSTIME;
1248         } else {
1249                 timespec_store(&its.it_value, delay);
1250                 flags = 0;
1251         }
1252
1253         /* This will also flush the elapse counter */
1254         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1255                 goto fail;
1256
1257         if (w->type == WATCH_INVALID) {
1258                 struct epoll_event ev;
1259
1260                 zero(ev);
1261                 ev.data.ptr = w;
1262                 ev.events = EPOLLIN;
1263
1264                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1265                         goto fail;
1266         }
1267
1268         w->type = WATCH_UNIT_TIMER;
1269         w->fd = fd;
1270         w->data.unit = u;
1271
1272         return 0;
1273
1274 fail:
1275         if (ours)
1276                 close_nointr_nofail(fd);
1277
1278         return -errno;
1279 }
1280
1281 void unit_unwatch_timer(Unit *u, Watch *w) {
1282         assert(u);
1283         assert(w);
1284
1285         if (w->type == WATCH_INVALID)
1286                 return;
1287
1288         assert(w->type == WATCH_UNIT_TIMER);
1289         assert(w->data.unit == u);
1290         assert(w->fd >= 0);
1291
1292         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1293         close_nointr_nofail(w->fd);
1294
1295         w->fd = -1;
1296         w->type = WATCH_INVALID;
1297         w->data.unit = NULL;
1298 }
1299
1300 bool unit_job_is_applicable(Unit *u, JobType j) {
1301         assert(u);
1302         assert(j >= 0 && j < _JOB_TYPE_MAX);
1303
1304         switch (j) {
1305
1306         case JOB_VERIFY_ACTIVE:
1307         case JOB_START:
1308                 return true;
1309
1310         case JOB_STOP:
1311         case JOB_RESTART:
1312         case JOB_TRY_RESTART:
1313                 return unit_can_start(u);
1314
1315         case JOB_RELOAD:
1316                 return unit_can_reload(u);
1317
1318         case JOB_RELOAD_OR_START:
1319                 return unit_can_reload(u) && unit_can_start(u);
1320
1321         default:
1322                 assert_not_reached("Invalid job type");
1323         }
1324 }
1325
1326 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1327
1328         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1329                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1330                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1331                 [UNIT_WANTS] = UNIT_WANTED_BY,
1332                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1333                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1334                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1335                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1336                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1337                 [UNIT_CONFLICTS] = UNIT_CONFLICTED_BY,
1338                 [UNIT_CONFLICTED_BY] = UNIT_CONFLICTS,
1339                 [UNIT_BEFORE] = UNIT_AFTER,
1340                 [UNIT_AFTER] = UNIT_BEFORE,
1341                 [UNIT_ON_FAILURE] = _UNIT_DEPENDENCY_INVALID,
1342                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1343                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1344         };
1345         int r, q = 0, v = 0, w = 0;
1346
1347         assert(u);
1348         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1349         assert(other);
1350
1351         /* We won't allow dependencies on ourselves. We will not
1352          * consider them an error however. */
1353         if (u == other)
1354                 return 0;
1355
1356         if (UNIT_VTABLE(u)->no_requires &&
1357             (d == UNIT_REQUIRES ||
1358              d == UNIT_REQUIRES_OVERRIDABLE ||
1359              d == UNIT_REQUISITE ||
1360              d == UNIT_REQUISITE_OVERRIDABLE)) {
1361                     return -EINVAL;
1362         }
1363
1364         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
1365                 return r;
1366
1367         if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
1368                 if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1369                         return r;
1370
1371         if (add_reference)
1372                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1373                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1374                         return r;
1375
1376         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1377                 return q;
1378
1379         if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
1380                 if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1381                         r = v;
1382                         goto fail;
1383                 }
1384
1385         if (add_reference) {
1386                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1387                         r = w;
1388                         goto fail;
1389                 }
1390
1391                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1392                         goto fail;
1393         }
1394
1395         unit_add_to_dbus_queue(u);
1396         return 0;
1397
1398 fail:
1399         if (q > 0)
1400                 set_remove(u->meta.dependencies[d], other);
1401
1402         if (v > 0)
1403                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1404
1405         if (w > 0)
1406                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1407
1408         return r;
1409 }
1410
1411 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference) {
1412         int r;
1413
1414         assert(u);
1415
1416         if ((r = unit_add_dependency(u, d, other, add_reference)) < 0)
1417                 return r;
1418
1419         if ((r = unit_add_dependency(u, e, other, add_reference)) < 0)
1420                 return r;
1421
1422         return 0;
1423 }
1424
1425 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1426         char *s;
1427
1428         assert(u);
1429         assert(name || path);
1430
1431         if (!name)
1432                 name = file_name_from_path(path);
1433
1434         if (!unit_name_is_template(name)) {
1435                 *p = NULL;
1436                 return name;
1437         }
1438
1439         if (u->meta.instance)
1440                 s = unit_name_replace_instance(name, u->meta.instance);
1441         else {
1442                 char *i;
1443
1444                 if (!(i = unit_name_to_prefix(u->meta.id)))
1445                         return NULL;
1446
1447                 s = unit_name_replace_instance(name, i);
1448                 free(i);
1449         }
1450
1451         if (!s)
1452                 return NULL;
1453
1454         *p = s;
1455         return s;
1456 }
1457
1458 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1459         Unit *other;
1460         int r;
1461         char *s;
1462
1463         assert(u);
1464         assert(name || path);
1465
1466         if (!(name = resolve_template(u, name, path, &s)))
1467                 return -ENOMEM;
1468
1469         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1470                 goto finish;
1471
1472         r = unit_add_dependency(u, d, other, add_reference);
1473
1474 finish:
1475         free(s);
1476         return r;
1477 }
1478
1479 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1480         Unit *other;
1481         int r;
1482         char *s;
1483
1484         assert(u);
1485         assert(name || path);
1486
1487         if (!(name = resolve_template(u, name, path, &s)))
1488                 return -ENOMEM;
1489
1490         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1491                 goto finish;
1492
1493         r = unit_add_two_dependencies(u, d, e, other, add_reference);
1494
1495 finish:
1496         free(s);
1497         return r;
1498 }
1499
1500 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1501         Unit *other;
1502         int r;
1503         char *s;
1504
1505         assert(u);
1506         assert(name || path);
1507
1508         if (!(name = resolve_template(u, name, path, &s)))
1509                 return -ENOMEM;
1510
1511         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1512                 goto finish;
1513
1514         r = unit_add_dependency(other, d, u, add_reference);
1515
1516 finish:
1517         free(s);
1518         return r;
1519 }
1520
1521 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1522         Unit *other;
1523         int r;
1524         char *s;
1525
1526         assert(u);
1527         assert(name || path);
1528
1529         if (!(name = resolve_template(u, name, path, &s)))
1530                 return -ENOMEM;
1531
1532         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1533                 goto finish;
1534
1535         if ((r = unit_add_two_dependencies(other, d, e, u, add_reference)) < 0)
1536                 goto finish;
1537
1538 finish:
1539         free(s);
1540         return r;
1541 }
1542
1543 int set_unit_path(const char *p) {
1544         char *cwd, *c;
1545         int r;
1546
1547         /* This is mostly for debug purposes */
1548
1549         if (path_is_absolute(p)) {
1550                 if (!(c = strdup(p)))
1551                         return -ENOMEM;
1552         } else {
1553                 if (!(cwd = get_current_dir_name()))
1554                         return -errno;
1555
1556                 r = asprintf(&c, "%s/%s", cwd, p);
1557                 free(cwd);
1558
1559                 if (r < 0)
1560                         return -ENOMEM;
1561         }
1562
1563         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1564                 r = -errno;
1565                 free(c);
1566                 return r;
1567         }
1568
1569         return 0;
1570 }
1571
1572 char *unit_dbus_path(Unit *u) {
1573         char *p, *e;
1574
1575         assert(u);
1576
1577         if (!u->meta.id)
1578                 return NULL;
1579
1580         if (!(e = bus_path_escape(u->meta.id)))
1581                 return NULL;
1582
1583         p = strappend("/org/freedesktop/systemd1/unit/", e);
1584         free(e);
1585
1586         return p;
1587 }
1588
1589 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1590         CGroupBonding *l;
1591         int r;
1592
1593         assert(u);
1594         assert(b);
1595
1596         assert(b->path);
1597
1598         if (!b->controller)
1599                 if (!(b->controller = strdup(SYSTEMD_CGROUP_CONTROLLER)))
1600                         return -ENOMEM;
1601
1602         /* Ensure this hasn't been added yet */
1603         assert(!b->unit);
1604
1605         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1606         LIST_PREPEND(CGroupBonding, by_path, l, b);
1607
1608         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1609                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1610                 return r;
1611         }
1612
1613         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1614         b->unit = u;
1615
1616         return 0;
1617 }
1618
1619 static char *default_cgroup_path(Unit *u) {
1620         char *p;
1621         int r;
1622
1623         assert(u);
1624
1625         if (u->meta.instance) {
1626                 char *t;
1627
1628                 if (!(t = unit_name_template(u->meta.id)))
1629                         return NULL;
1630
1631                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1632                 free(t);
1633         } else
1634                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1635
1636         return r < 0 ? NULL : p;
1637 }
1638
1639 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1640         char *controller = NULL, *path = NULL;
1641         CGroupBonding *b = NULL;
1642         int r;
1643
1644         assert(u);
1645         assert(name);
1646
1647         if ((r = cg_split_spec(name, &controller, &path)) < 0)
1648                 return r;
1649
1650         if (!path)
1651                 path = default_cgroup_path(u);
1652
1653         if (!controller)
1654                 controller = strdup(SYSTEMD_CGROUP_CONTROLLER);
1655
1656         if (!path || !controller) {
1657                 free(path);
1658                 free(controller);
1659
1660                 return -ENOMEM;
1661         }
1662
1663         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1664                 r = -EEXIST;
1665                 goto fail;
1666         }
1667
1668         if (!(b = new0(CGroupBonding, 1))) {
1669                 r = -ENOMEM;
1670                 goto fail;
1671         }
1672
1673         b->controller = controller;
1674         b->path = path;
1675         b->only_us = false;
1676         b->clean_up = false;
1677
1678         if ((r = unit_add_cgroup(u, b)) < 0)
1679                 goto fail;
1680
1681         return 0;
1682
1683 fail:
1684         free(path);
1685         free(controller);
1686         free(b);
1687
1688         return r;
1689 }
1690
1691 int unit_add_default_cgroup(Unit *u) {
1692         CGroupBonding *b;
1693         int r = -ENOMEM;
1694
1695         assert(u);
1696
1697         /* Adds in the default cgroup data, if it wasn't specified yet */
1698
1699         if (unit_get_default_cgroup(u))
1700                 return 0;
1701
1702         if (!(b = new0(CGroupBonding, 1)))
1703                 return -ENOMEM;
1704
1705         if (!(b->path = default_cgroup_path(u)))
1706                 goto fail;
1707
1708         b->clean_up = true;
1709         b->only_us = true;
1710
1711         if ((r = unit_add_cgroup(u, b)) < 0)
1712                 goto fail;
1713
1714         return 0;
1715
1716 fail:
1717         free(b->path);
1718         free(b->controller);
1719         free(b);
1720
1721         return r;
1722 }
1723
1724 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1725         assert(u);
1726
1727         return cgroup_bonding_find_list(u->meta.cgroup_bondings, SYSTEMD_CGROUP_CONTROLLER);
1728 }
1729
1730 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1731         char *t;
1732         int r;
1733
1734         assert(u);
1735         assert(type);
1736         assert(_found);
1737
1738         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1739                 return -ENOMEM;
1740
1741         assert(!unit_has_name(u, t));
1742
1743         r = manager_load_unit(u->meta.manager, t, NULL, NULL, _found);
1744         free(t);
1745
1746         assert(r < 0 || *_found != u);
1747
1748         return r;
1749 }
1750
1751 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1752         Unit *found;
1753         char *t;
1754
1755         assert(u);
1756         assert(type);
1757         assert(_found);
1758
1759         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1760                 return -ENOMEM;
1761
1762         assert(!unit_has_name(u, t));
1763
1764         found = manager_get_unit(u->meta.manager, t);
1765         free(t);
1766
1767         if (!found)
1768                 return -ENOENT;
1769
1770         *_found = found;
1771         return 0;
1772 }
1773
1774 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1775         Unit *u = userdata;
1776         assert(u);
1777
1778         return unit_name_to_prefix_and_instance(u->meta.id);
1779 }
1780
1781 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1782         Unit *u = userdata;
1783         assert(u);
1784
1785         return unit_name_to_prefix(u->meta.id);
1786 }
1787
1788 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1789         Unit *u = userdata;
1790         char *p, *r;
1791
1792         assert(u);
1793
1794         if (!(p = unit_name_to_prefix(u->meta.id)))
1795                 return NULL;
1796
1797         r = unit_name_unescape(p);
1798         free(p);
1799
1800         return r;
1801 }
1802
1803 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1804         Unit *u = userdata;
1805         assert(u);
1806
1807         if (u->meta.instance)
1808                 return unit_name_unescape(u->meta.instance);
1809
1810         return strdup("");
1811 }
1812
1813 char *unit_name_printf(Unit *u, const char* format) {
1814
1815         /*
1816          * This will use the passed string as format string and
1817          * replace the following specifiers:
1818          *
1819          * %n: the full id of the unit                 (foo@bar.waldo)
1820          * %N: the id of the unit without the suffix   (foo@bar)
1821          * %p: the prefix                              (foo)
1822          * %i: the instance                            (bar)
1823          */
1824
1825         const Specifier table[] = {
1826                 { 'n', specifier_string,              u->meta.id },
1827                 { 'N', specifier_prefix_and_instance, NULL },
1828                 { 'p', specifier_prefix,              NULL },
1829                 { 'i', specifier_string,              u->meta.instance },
1830                 { 0, NULL, NULL }
1831         };
1832
1833         assert(u);
1834         assert(format);
1835
1836         return specifier_printf(format, table, u);
1837 }
1838
1839 char *unit_full_printf(Unit *u, const char *format) {
1840
1841         /* This is similar to unit_name_printf() but also supports
1842          * unescaping */
1843
1844         const Specifier table[] = {
1845                 { 'n', specifier_string,              u->meta.id },
1846                 { 'N', specifier_prefix_and_instance, NULL },
1847                 { 'p', specifier_prefix,              NULL },
1848                 { 'P', specifier_prefix_unescaped,    NULL },
1849                 { 'i', specifier_string,              u->meta.instance },
1850                 { 'I', specifier_instance_unescaped,  NULL },
1851                 { 0, NULL, NULL }
1852         };
1853
1854         assert(u);
1855         assert(format);
1856
1857         return specifier_printf(format, table, u);
1858 }
1859
1860 char **unit_full_printf_strv(Unit *u, char **l) {
1861         size_t n;
1862         char **r, **i, **j;
1863
1864         /* Applies unit_full_printf to every entry in l */
1865
1866         assert(u);
1867
1868         n = strv_length(l);
1869         if (!(r = new(char*, n+1)))
1870                 return NULL;
1871
1872         for (i = l, j = r; *i; i++, j++)
1873                 if (!(*j = unit_full_printf(u, *i)))
1874                         goto fail;
1875
1876         *j = NULL;
1877         return r;
1878
1879 fail:
1880         j--;
1881         while (j >= r)
1882                 free(*j);
1883
1884         free(r);
1885
1886         return NULL;
1887 }
1888
1889 int unit_watch_bus_name(Unit *u, const char *name) {
1890         assert(u);
1891         assert(name);
1892
1893         /* Watch a specific name on the bus. We only support one unit
1894          * watching each name for now. */
1895
1896         return hashmap_put(u->meta.manager->watch_bus, name, u);
1897 }
1898
1899 void unit_unwatch_bus_name(Unit *u, const char *name) {
1900         assert(u);
1901         assert(name);
1902
1903         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1904 }
1905
1906 bool unit_can_serialize(Unit *u) {
1907         assert(u);
1908
1909         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1910 }
1911
1912 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1913         int r;
1914
1915         assert(u);
1916         assert(f);
1917         assert(fds);
1918
1919         if (!unit_can_serialize(u))
1920                 return 0;
1921
1922         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1923                 return r;
1924
1925         if (u->meta.job)
1926                 unit_serialize_item(u, f, "job", job_type_to_string(u->meta.job->type));
1927
1928         /* End marker */
1929         fputc('\n', f);
1930         return 0;
1931 }
1932
1933 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1934         va_list ap;
1935
1936         assert(u);
1937         assert(f);
1938         assert(key);
1939         assert(format);
1940
1941         fputs(key, f);
1942         fputc('=', f);
1943
1944         va_start(ap, format);
1945         vfprintf(f, format, ap);
1946         va_end(ap);
1947
1948         fputc('\n', f);
1949 }
1950
1951 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1952         assert(u);
1953         assert(f);
1954         assert(key);
1955         assert(value);
1956
1957         fprintf(f, "%s=%s\n", key, value);
1958 }
1959
1960 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1961         int r;
1962
1963         assert(u);
1964         assert(f);
1965         assert(fds);
1966
1967         if (!unit_can_serialize(u))
1968                 return 0;
1969
1970         for (;;) {
1971                 char line[1024], *l, *v;
1972                 size_t k;
1973
1974                 if (!fgets(line, sizeof(line), f)) {
1975                         if (feof(f))
1976                                 return 0;
1977                         return -errno;
1978                 }
1979
1980                 char_array_0(line);
1981                 l = strstrip(line);
1982
1983                 /* End marker */
1984                 if (l[0] == 0)
1985                         return 0;
1986
1987                 k = strcspn(l, "=");
1988
1989                 if (l[k] == '=') {
1990                         l[k] = 0;
1991                         v = l+k+1;
1992                 } else
1993                         v = l+k;
1994
1995                 if (streq(l, "job")) {
1996                         JobType type;
1997
1998                         if ((type = job_type_from_string(v)) < 0)
1999                                 log_debug("Failed to parse job type value %s", v);
2000                         else
2001                                 u->meta.deserialized_job = type;
2002
2003                         continue;
2004                 }
2005
2006                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
2007                         return r;
2008         }
2009 }
2010
2011 int unit_add_node_link(Unit *u, const char *what, bool wants) {
2012         Unit *device;
2013         char *e;
2014         int r;
2015
2016         assert(u);
2017
2018         if (!what)
2019                 return 0;
2020
2021         /* Adds in links to the device node that this unit is based on */
2022
2023         if (!is_device_path(what))
2024                 return 0;
2025
2026         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
2027                 return -ENOMEM;
2028
2029         r = manager_load_unit(u->meta.manager, e, NULL, NULL, &device);
2030         free(e);
2031
2032         if (r < 0)
2033                 return r;
2034
2035         if ((r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_REQUIRES, device, true)) < 0)
2036                 return r;
2037
2038         if (wants)
2039                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
2040                         return r;
2041
2042         return 0;
2043 }
2044
2045 int unit_coldplug(Unit *u) {
2046         int r;
2047
2048         assert(u);
2049
2050         if (UNIT_VTABLE(u)->coldplug)
2051                 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
2052                         return r;
2053
2054         if (u->meta.deserialized_job >= 0) {
2055                 if ((r = manager_add_job(u->meta.manager, u->meta.deserialized_job, u, JOB_FAIL, false, NULL, NULL)) < 0)
2056                         return r;
2057
2058                 u->meta.deserialized_job = _JOB_TYPE_INVALID;
2059         }
2060
2061         return 0;
2062 }
2063
2064 void unit_status_printf(Unit *u, const char *format, ...) {
2065         va_list ap;
2066
2067         assert(u);
2068         assert(format);
2069
2070         if (!UNIT_VTABLE(u)->show_status)
2071                 return;
2072
2073         if (u->meta.manager->running_as != MANAGER_SYSTEM)
2074                 return;
2075
2076         if (!u->meta.manager->show_status)
2077                 return;
2078
2079         if (!manager_is_booting_or_shutting_down(u->meta.manager))
2080                 return;
2081
2082         va_start(ap, format);
2083         status_vprintf(format, ap);
2084         va_end(ap);
2085 }
2086
2087 bool unit_need_daemon_reload(Unit *u) {
2088         struct stat st;
2089
2090         assert(u);
2091
2092         if (!u->meta.fragment_path)
2093                 return false;
2094
2095         zero(st);
2096         if (stat(u->meta.fragment_path, &st) < 0)
2097                 /* What, cannot access this anymore? */
2098                 return true;
2099
2100         return
2101                 u->meta.fragment_mtime &&
2102                 timespec_load(&st.st_mtim) != u->meta.fragment_mtime;
2103 }
2104
2105 void unit_reset_maintenance(Unit *u) {
2106         assert(u);
2107
2108         if (UNIT_VTABLE(u)->reset_maintenance)
2109                 UNIT_VTABLE(u)->reset_maintenance(u);
2110 }
2111
2112 Unit *unit_following(Unit *u) {
2113         assert(u);
2114
2115         if (UNIT_VTABLE(u)->following)
2116                 return UNIT_VTABLE(u)->following(u);
2117
2118         return NULL;
2119 }
2120
2121 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
2122         [UNIT_STUB] = "stub",
2123         [UNIT_LOADED] = "loaded",
2124         [UNIT_FAILED] = "failed",
2125         [UNIT_MERGED] = "merged"
2126 };
2127
2128 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
2129
2130 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
2131         [UNIT_ACTIVE] = "active",
2132         [UNIT_RELOADING] = "reloading",
2133         [UNIT_INACTIVE] = "inactive",
2134         [UNIT_MAINTENANCE] = "maintenance",
2135         [UNIT_ACTIVATING] = "activating",
2136         [UNIT_DEACTIVATING] = "deactivating"
2137 };
2138
2139 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
2140
2141 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
2142         [UNIT_REQUIRES] = "Requires",
2143         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
2144         [UNIT_WANTS] = "Wants",
2145         [UNIT_REQUISITE] = "Requisite",
2146         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
2147         [UNIT_REQUIRED_BY] = "RequiredBy",
2148         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
2149         [UNIT_WANTED_BY] = "WantedBy",
2150         [UNIT_CONFLICTS] = "Conflicts",
2151         [UNIT_CONFLICTED_BY] = "ConflictedBy",
2152         [UNIT_BEFORE] = "Before",
2153         [UNIT_AFTER] = "After",
2154         [UNIT_REFERENCES] = "References",
2155         [UNIT_REFERENCED_BY] = "ReferencedBy",
2156         [UNIT_ON_FAILURE] = "OnFailure"
2157 };
2158
2159 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
2160
2161 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
2162         [KILL_CONTROL_GROUP] = "control-group",
2163         [KILL_PROCESS_GROUP] = "process-group",
2164         [KILL_PROCESS] = "process",
2165         [KILL_NONE] = "none"
2166 };
2167
2168 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);