src/unit.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   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
  31 #include "set.h"
  32 #include "unit.h"
  33 #include "macro.h"
  34 #include "strv.h"
  35 #include "load-fragment.h"
  36 #include "load-dropin.h"
  37 #include "log.h"
  38 #include "unit-name.h"
  39 #include "specifier.h"
  40 #include "dbus-unit.h"
  41 #include "special.h"
  42
  43 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
  44         [UNIT_SERVICE] = &service_vtable,
  45         [UNIT_TIMER] = &timer_vtable,
  46         [UNIT_SOCKET] = &socket_vtable,
  47         [UNIT_TARGET] = &target_vtable,
  48         [UNIT_DEVICE] = &device_vtable,
  49         [UNIT_MOUNT] = &mount_vtable,
  50         [UNIT_AUTOMOUNT] = &automount_vtable,
  51         [UNIT_SNAPSHOT] = &snapshot_vtable,
  52         [UNIT_SWAP] = &swap_vtable,
  53         [UNIT_PATH] = &path_vtable
  54 };
  55
  56 Unit *unit_new(Manager *m) {
  57         Unit *u;
  58
  59         assert(m);
  60
  61         if (!(u = new0(Unit, 1)))
  62                 return NULL;
  63
  64         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
  65                 free(u);
  66                 return NULL;
  67         }
  68
  69         u->meta.manager = m;
  70         u->meta.type = _UNIT_TYPE_INVALID;
  71         u->meta.deserialized_job = _JOB_TYPE_INVALID;
  72         u->meta.default_dependencies = true;
  73
  74         return u;
  75 }
  76
  77 bool unit_has_name(Unit *u, const char *name) {
  78         assert(u);
  79         assert(name);
  80
  81         return !!set_get(u->meta.names, (char*) name);
  82 }
  83
  84 int unit_add_name(Unit *u, const char *text) {
  85         UnitType t;
  86         char *s = NULL, *i = NULL;
  87         int r;
  88
  89         assert(u);
  90         assert(text);
  91
  92         if (unit_name_is_template(text)) {
  93                 if (!u->meta.instance)
  94                         return -EINVAL;
  95
  96                 s = unit_name_replace_instance(text, u->meta.instance);
  97         } else
  98                 s = strdup(text);
  99
 100         if (!s)
 101                 return -ENOMEM;
 102
 103         if (!unit_name_is_valid(s)) {
 104                 r = -EINVAL;
 105                 goto fail;
 106         }
 107
 108         assert_se((t = unit_name_to_type(s)) >= 0);
 109
 110         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
 111                 r = -EINVAL;
 112                 goto fail;
 113         }
 114
 115         if ((r = unit_name_to_instance(s, &i)) < 0)
 116                 goto fail;
 117
 118         if (i && unit_vtable[t]->no_instances)
 119                 goto fail;
 120
 121         if (u->meta.type != _UNIT_TYPE_INVALID && !streq_ptr(u->meta.instance, i)) {
 122                 r = -EINVAL;
 123                 goto fail;
 124         }
 125
 126         if (unit_vtable[t]->no_alias &&
 127             !set_isempty(u->meta.names) &&
 128             !set_get(u->meta.names, s)) {
 129                 r = -EEXIST;
 130                 goto fail;
 131         }
 132
 133         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
 134                 r = -E2BIG;
 135                 goto fail;
 136         }
 137
 138         if ((r = set_put(u->meta.names, s)) < 0) {
 139                 if (r == -EEXIST)
 140                         r = 0;
 141                 goto fail;
 142         }
 143
 144         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 145                 set_remove(u->meta.names, s);
 146                 goto fail;
 147         }
 148
 149         if (u->meta.type == _UNIT_TYPE_INVALID) {
 150
 151                 u->meta.type = t;
 152                 u->meta.id = s;
 153                 u->meta.instance = i;
 154
 155                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 156
 157                 if (UNIT_VTABLE(u)->init)
 158                         UNIT_VTABLE(u)->init(u);
 159         } else
 160                 free(i);
 161
 162         unit_add_to_dbus_queue(u);
 163         return 0;
 164
 165 fail:
 166         free(s);
 167         free(i);
 168
 169         return r;
 170 }
 171
 172 int unit_choose_id(Unit *u, const char *name) {
 173         char *s, *t = NULL;
 174
 175         assert(u);
 176         assert(name);
 177
 178         if (unit_name_is_template(name)) {
 179
 180                 if (!u->meta.instance)
 181                         return -EINVAL;
 182
 183                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
 184                         return -ENOMEM;
 185
 186                 name = t;
 187         }
 188
 189         /* Selects one of the names of this unit as the id */
 190         s = set_get(u->meta.names, (char*) name);
 191         free(t);
 192
 193         if (!s)
 194                 return -ENOENT;
 195
 196         u->meta.id = s;
 197         unit_add_to_dbus_queue(u);
 198
 199         return 0;
 200 }
 201
 202 int unit_set_description(Unit *u, const char *description) {
 203         char *s;
 204
 205         assert(u);
 206
 207         if (!(s = strdup(description)))
 208                 return -ENOMEM;
 209
 210         free(u->meta.description);
 211         u->meta.description = s;
 212
 213         unit_add_to_dbus_queue(u);
 214         return 0;
 215 }
 216
 217 bool unit_check_gc(Unit *u) {
 218         assert(u);
 219
 220         if (u->meta.load_state == UNIT_STUB)
 221                 return true;
 222
 223         if (UNIT_VTABLE(u)->no_gc)
 224                 return true;
 225
 226         if (u->meta.job)
 227                 return true;
 228
 229         if (unit_active_state(u) != UNIT_INACTIVE)
 230                 return true;
 231
 232         if (UNIT_VTABLE(u)->check_gc)
 233                 if (UNIT_VTABLE(u)->check_gc(u))
 234                         return true;
 235
 236         return false;
 237 }
 238
 239 void unit_add_to_load_queue(Unit *u) {
 240         assert(u);
 241         assert(u->meta.type != _UNIT_TYPE_INVALID);
 242
 243         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 244                 return;
 245
 246         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 247         u->meta.in_load_queue = true;
 248 }
 249
 250 void unit_add_to_cleanup_queue(Unit *u) {
 251         assert(u);
 252
 253         if (u->meta.in_cleanup_queue)
 254                 return;
 255
 256         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 257         u->meta.in_cleanup_queue = true;
 258 }
 259
 260 void unit_add_to_gc_queue(Unit *u) {
 261         assert(u);
 262
 263         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 264                 return;
 265
 266         if (unit_check_gc(u))
 267                 return;
 268
 269         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 270         u->meta.in_gc_queue = true;
 271
 272         u->meta.manager->n_in_gc_queue ++;
 273
 274         if (u->meta.manager->gc_queue_timestamp <= 0)
 275                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 276 }
 277
 278 void unit_add_to_dbus_queue(Unit *u) {
 279         assert(u);
 280         assert(u->meta.type != _UNIT_TYPE_INVALID);
 281
 282         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue)
 283                 return;
 284
 285         /* Shortcut things if nobody cares */
 286         if (!bus_has_subscriber(u->meta.manager)) {
 287                 u->meta.sent_dbus_new_signal = true;
 288                 return;
 289         }
 290
 291         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 292         u->meta.in_dbus_queue = true;
 293 }
 294
 295 static void bidi_set_free(Unit *u, Set *s) {
 296         Iterator i;
 297         Unit *other;
 298
 299         assert(u);
 300
 301         /* Frees the set and makes sure we are dropped from the
 302          * inverse pointers */
 303
 304         SET_FOREACH(other, s, i) {
 305                 UnitDependency d;
 306
 307                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 308                         set_remove(other->meta.dependencies[d], u);
 309
 310                 unit_add_to_gc_queue(other);
 311         }
 312
 313         set_free(s);
 314 }
 315
 316 void unit_free(Unit *u) {
 317         UnitDependency d;
 318         Iterator i;
 319         char *t;
 320
 321         assert(u);
 322
 323         bus_unit_send_removed_signal(u);
 324
 325         if (u->meta.load_state != UNIT_STUB)
 326                 if (UNIT_VTABLE(u)->done)
 327                         UNIT_VTABLE(u)->done(u);
 328
 329         SET_FOREACH(t, u->meta.names, i)
 330                 hashmap_remove_value(u->meta.manager->units, t, u);
 331
 332         if (u->meta.job)
 333                 job_free(u->meta.job);
 334
 335         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 336                 bidi_set_free(u, u->meta.dependencies[d]);
 337
 338         if (u->meta.type != _UNIT_TYPE_INVALID)
 339                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 340
 341         if (u->meta.in_load_queue)
 342                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 343
 344         if (u->meta.in_dbus_queue)
 345                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 346
 347         if (u->meta.in_cleanup_queue)
 348                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 349
 350         if (u->meta.in_gc_queue) {
 351                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 352                 u->meta.manager->n_in_gc_queue--;
 353         }
 354
 355         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 356
 357         free(u->meta.description);
 358         free(u->meta.fragment_path);
 359
 360         set_free_free(u->meta.names);
 361
 362         free(u->meta.instance);
 363
 364         free(u);
 365 }
 366
 367 UnitActiveState unit_active_state(Unit *u) {
 368         assert(u);
 369
 370         if (u->meta.load_state == UNIT_MERGED)
 371                 return unit_active_state(unit_follow_merge(u));
 372
 373         /* After a reload it might happen that a unit is not correctly
 374          * loaded but still has a process around. That's why we won't
 375          * shortcut failed loading to UNIT_INACTIVE_MAINTENANCE. */
 376
 377         return UNIT_VTABLE(u)->active_state(u);
 378 }
 379
 380 const char* unit_sub_state_to_string(Unit *u) {
 381         assert(u);
 382
 383         return UNIT_VTABLE(u)->sub_state_to_string(u);
 384 }
 385
 386 static void complete_move(Set **s, Set **other) {
 387         assert(s);
 388         assert(other);
 389
 390         if (!*other)
 391                 return;
 392
 393         if (*s)
 394                 set_move(*s, *other);
 395         else {
 396                 *s = *other;
 397                 *other = NULL;
 398         }
 399 }
 400
 401 static void merge_names(Unit *u, Unit *other) {
 402         char *t;
 403         Iterator i;
 404
 405         assert(u);
 406         assert(other);
 407
 408         complete_move(&u->meta.names, &other->meta.names);
 409
 410         set_free_free(other->meta.names);
 411         other->meta.names = NULL;
 412         other->meta.id = NULL;
 413
 414         SET_FOREACH(t, u->meta.names, i)
 415                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
 416 }
 417
 418 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
 419         Iterator i;
 420         Unit *back;
 421         int r;
 422
 423         assert(u);
 424         assert(other);
 425         assert(d < _UNIT_DEPENDENCY_MAX);
 426
 427         SET_FOREACH(back, other->meta.dependencies[d], i) {
 428                 UnitDependency k;
 429
 430                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
 431                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
 432
 433                                 if (r == -EEXIST)
 434                                         set_remove(back->meta.dependencies[k], other);
 435                                 else
 436                                         assert(r == -ENOENT);
 437                         }
 438         }
 439
 440         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
 441
 442         set_free(other->meta.dependencies[d]);
 443         other->meta.dependencies[d] = NULL;
 444 }
 445
 446 int unit_merge(Unit *u, Unit *other) {
 447         UnitDependency d;
 448
 449         assert(u);
 450         assert(other);
 451         assert(u->meta.manager == other->meta.manager);
 452         assert(u->meta.type != _UNIT_TYPE_INVALID);
 453
 454         other = unit_follow_merge(other);
 455
 456         if (other == u)
 457                 return 0;
 458
 459         if (u->meta.type != other->meta.type)
 460                 return -EINVAL;
 461
 462         if (!streq_ptr(u->meta.instance, other->meta.instance))
 463                 return -EINVAL;
 464
 465         if (other->meta.load_state != UNIT_STUB &&
 466             other->meta.load_state != UNIT_FAILED)
 467                 return -EEXIST;
 468
 469         if (other->meta.job)
 470                 return -EEXIST;
 471
 472         if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(other)))
 473                 return -EEXIST;
 474
 475         /* Merge names */
 476         merge_names(u, other);
 477
 478         /* Merge dependencies */
 479         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 480                 merge_dependencies(u, other, d);
 481
 482         other->meta.load_state = UNIT_MERGED;
 483         other->meta.merged_into = u;
 484
 485         /* If there is still some data attached to the other node, we
 486          * don't need it anymore, and can free it. */
 487         if (other->meta.load_state != UNIT_STUB)
 488                 if (UNIT_VTABLE(other)->done)
 489                         UNIT_VTABLE(other)->done(other);
 490
 491         unit_add_to_dbus_queue(u);
 492         unit_add_to_cleanup_queue(other);
 493
 494         return 0;
 495 }
 496
 497 int unit_merge_by_name(Unit *u, const char *name) {
 498         Unit *other;
 499         int r;
 500         char *s = NULL;
 501
 502         assert(u);
 503         assert(name);
 504
 505         if (unit_name_is_template(name)) {
 506                 if (!u->meta.instance)
 507                         return -EINVAL;
 508
 509                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
 510                         return -ENOMEM;
 511
 512                 name = s;
 513         }
 514
 515         if (!(other = manager_get_unit(u->meta.manager, name)))
 516                 r = unit_add_name(u, name);
 517         else
 518                 r = unit_merge(u, other);
 519
 520         free(s);
 521         return r;
 522 }
 523
 524 Unit* unit_follow_merge(Unit *u) {
 525         assert(u);
 526
 527         while (u->meta.load_state == UNIT_MERGED)
 528                 assert_se(u = u->meta.merged_into);
 529
 530         return u;
 531 }
 532
 533 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 534         int r;
 535
 536         assert(u);
 537         assert(c);
 538
 539         if (c->std_output != EXEC_OUTPUT_KMSG &&
 540             c->std_output != EXEC_OUTPUT_SYSLOG &&
 541             c->std_error != EXEC_OUTPUT_KMSG &&
 542             c->std_error != EXEC_OUTPUT_SYSLOG)
 543                 return 0;
 544
 545         /* If syslog or kernel logging is requested, make sure our own
 546          * logging daemon is run first. */
 547
 548         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 549                 return r;
 550
 551         if (u->meta.manager->running_as == MANAGER_SYSTEM)
 552                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 553                         return r;
 554
 555         return 0;
 556 }
 557
 558 const char *unit_description(Unit *u) {
 559         assert(u);
 560
 561         if (u->meta.description)
 562                 return u->meta.description;
 563
 564         return u->meta.id;
 565 }
 566
 567 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 568         char *t;
 569         UnitDependency d;
 570         Iterator i;
 571         char *p2;
 572         const char *prefix2;
 573         CGroupBonding *b;
 574         char
 575                 timestamp1[FORMAT_TIMESTAMP_MAX],
 576                 timestamp2[FORMAT_TIMESTAMP_MAX],
 577                 timestamp3[FORMAT_TIMESTAMP_MAX],
 578                 timestamp4[FORMAT_TIMESTAMP_MAX];
 579
 580         assert(u);
 581         assert(u->meta.type >= 0);
 582
 583         if (!prefix)
 584                 prefix = "";
 585         p2 = strappend(prefix, "\t");
 586         prefix2 = p2 ? p2 : prefix;
 587
 588         fprintf(f,
 589                 "%s-> Unit %s:\n"
 590                 "%s\tDescription: %s\n"
 591                 "%s\tInstance: %s\n"
 592                 "%s\tUnit Load State: %s\n"
 593                 "%s\tUnit Active State: %s\n"
 594                 "%s\tInactive Exit Timestamp: %s\n"
 595                 "%s\tActive Enter Timestamp: %s\n"
 596                 "%s\tActive Exit Timestamp: %s\n"
 597                 "%s\tInactive Enter Timestamp: %s\n"
 598                 "%s\tGC Check Good: %s\n",
 599                 prefix, u->meta.id,
 600                 prefix, unit_description(u),
 601                 prefix, strna(u->meta.instance),
 602                 prefix, unit_load_state_to_string(u->meta.load_state),
 603                 prefix, unit_active_state_to_string(unit_active_state(u)),
 604                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.inactive_exit_timestamp.realtime)),
 605                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_enter_timestamp.realtime)),
 606                 prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->meta.active_exit_timestamp.realtime)),
 607                 prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->meta.inactive_enter_timestamp.realtime)),
 608                 prefix, yes_no(unit_check_gc(u)));
 609
 610         SET_FOREACH(t, u->meta.names, i)
 611                 fprintf(f, "%s\tName: %s\n", prefix, t);
 612
 613         if (u->meta.fragment_path)
 614                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
 615
 616         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 617                 Unit *other;
 618
 619                 SET_FOREACH(other, u->meta.dependencies[d], i)
 620                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
 621         }
 622
 623         if (u->meta.load_state == UNIT_LOADED) {
 624                 fprintf(f,
 625                         "%s\tRecursive Stop: %s\n"
 626                         "%s\tStopWhenUnneeded: %s\n"
 627                         "%s\tOnlyByDependency: %s\n"
 628                         "%s\tDefaultDependencies: %s\n",
 629                         prefix, yes_no(u->meta.recursive_stop),
 630                         prefix, yes_no(u->meta.stop_when_unneeded),
 631                         prefix, yes_no(u->meta.only_by_dependency),
 632                         prefix, yes_no(u->meta.default_dependencies));
 633
 634                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
 635                         fprintf(f, "%s\tControlGroup: %s:%s\n",
 636                                 prefix, b->controller, b->path);
 637
 638                 if (UNIT_VTABLE(u)->dump)
 639                         UNIT_VTABLE(u)->dump(u, f, prefix2);
 640
 641         } else if (u->meta.load_state == UNIT_MERGED)
 642                 fprintf(f,
 643                         "%s\tMerged into: %s\n",
 644                         prefix, u->meta.merged_into->meta.id);
 645
 646         if (u->meta.job)
 647                 job_dump(u->meta.job, f, prefix2);
 648
 649         free(p2);
 650 }
 651
 652 /* Common implementation for multiple backends */
 653 int unit_load_fragment_and_dropin(Unit *u) {
 654         int r;
 655
 656         assert(u);
 657
 658         /* Load a .service file */
 659         if ((r = unit_load_fragment(u)) < 0)
 660                 return r;
 661
 662         if (u->meta.load_state == UNIT_STUB)
 663                 return -ENOENT;
 664
 665         /* Load drop-in directory data */
 666         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 667                 return r;
 668
 669         return 0;
 670 }
 671
 672 /* Common implementation for multiple backends */
 673 int unit_load_fragment_and_dropin_optional(Unit *u) {
 674         int r;
 675
 676         assert(u);
 677
 678         /* Same as unit_load_fragment_and_dropin(), but whether
 679          * something can be loaded or not doesn't matter. */
 680
 681         /* Load a .service file */
 682         if ((r = unit_load_fragment(u)) < 0)
 683                 return r;
 684
 685         if (u->meta.load_state == UNIT_STUB)
 686                 u->meta.load_state = UNIT_LOADED;
 687
 688         /* Load drop-in directory data */
 689         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 690                 return r;
 691
 692         return 0;
 693 }
 694
 695 /* Common implementation for multiple backends */
 696 int unit_load_nop(Unit *u) {
 697         assert(u);
 698
 699         if (u->meta.load_state == UNIT_STUB)
 700                 u->meta.load_state = UNIT_LOADED;
 701
 702         return 0;
 703 }
 704
 705 int unit_load(Unit *u) {
 706         int r;
 707
 708         assert(u);
 709
 710         if (u->meta.in_load_queue) {
 711                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 712                 u->meta.in_load_queue = false;
 713         }
 714
 715         if (u->meta.type == _UNIT_TYPE_INVALID)
 716                 return -EINVAL;
 717
 718         if (u->meta.load_state != UNIT_STUB)
 719                 return 0;
 720
 721         if (UNIT_VTABLE(u)->load)
 722                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
 723                         goto fail;
 724
 725         if (u->meta.load_state == UNIT_STUB) {
 726                 r = -ENOENT;
 727                 goto fail;
 728         }
 729
 730         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
 731
 732         unit_add_to_dbus_queue(unit_follow_merge(u));
 733         unit_add_to_gc_queue(u);
 734
 735         return 0;
 736
 737 fail:
 738         u->meta.load_state = UNIT_FAILED;
 739         unit_add_to_dbus_queue(u);
 740
 741         log_notice("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
 742
 743         return r;
 744 }
 745
 746 /* Errors:
 747  *         -EBADR:     This unit type does not support starting.
 748  *         -EALREADY:  Unit is already started.
 749  *         -EAGAIN:    An operation is already in progress. Retry later.
 750  *         -ECANCELED: Too many requests for now.
 751  */
 752 int unit_start(Unit *u) {
 753         UnitActiveState state;
 754
 755         assert(u);
 756
 757         if (u->meta.load_state != UNIT_LOADED)
 758                 return -EINVAL;
 759
 760         /* If this is already (being) started, then this will
 761          * succeed. Note that this will even succeed if this unit is
 762          * not startable by the user. This is relied on to detect when
 763          * we need to wait for units and when waiting is finished. */
 764         state = unit_active_state(u);
 765         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 766                 return -EALREADY;
 767
 768         /* If it is stopped, but we cannot start it, then fail */
 769         if (!UNIT_VTABLE(u)->start)
 770                 return -EBADR;
 771
 772         /* We don't suppress calls to ->start() here when we are
 773          * already starting, to allow this request to be used as a
 774          * "hurry up" call, for example when the unit is in some "auto
 775          * restart" state where it waits for a holdoff timer to elapse
 776          * before it will start again. */
 777
 778         unit_add_to_dbus_queue(u);
 779
 780         unit_status_printf(u, "Starting %s...\n", unit_description(u));
 781
 782         return UNIT_VTABLE(u)->start(u);
 783 }
 784
 785 bool unit_can_start(Unit *u) {
 786         assert(u);
 787
 788         return !!UNIT_VTABLE(u)->start;
 789 }
 790
 791 /* Errors:
 792  *         -EBADR:    This unit type does not support stopping.
 793  *         -EALREADY: Unit is already stopped.
 794  *         -EAGAIN:   An operation is already in progress. Retry later.
 795  */
 796 int unit_stop(Unit *u) {
 797         UnitActiveState state;
 798
 799         assert(u);
 800
 801         state = unit_active_state(u);
 802         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(state))
 803                 return -EALREADY;
 804
 805         if (!UNIT_VTABLE(u)->stop)
 806                 return -EBADR;
 807
 808         unit_add_to_dbus_queue(u);
 809
 810         unit_status_printf(u, "Stopping %s...\n", unit_description(u));
 811
 812         return UNIT_VTABLE(u)->stop(u);
 813 }
 814
 815 /* Errors:
 816  *         -EBADR:    This unit type does not support reloading.
 817  *         -ENOEXEC:  Unit is not started.
 818  *         -EAGAIN:   An operation is already in progress. Retry later.
 819  */
 820 int unit_reload(Unit *u) {
 821         UnitActiveState state;
 822
 823         assert(u);
 824
 825         if (u->meta.load_state != UNIT_LOADED)
 826                 return -EINVAL;
 827
 828         if (!unit_can_reload(u))
 829                 return -EBADR;
 830
 831         state = unit_active_state(u);
 832         if (unit_active_state(u) == UNIT_RELOADING)
 833                 return -EALREADY;
 834
 835         if (unit_active_state(u) != UNIT_ACTIVE)
 836                 return -ENOEXEC;
 837
 838         unit_add_to_dbus_queue(u);
 839         return UNIT_VTABLE(u)->reload(u);
 840 }
 841
 842 bool unit_can_reload(Unit *u) {
 843         assert(u);
 844
 845         if (!UNIT_VTABLE(u)->reload)
 846                 return false;
 847
 848         if (!UNIT_VTABLE(u)->can_reload)
 849                 return true;
 850
 851         return UNIT_VTABLE(u)->can_reload(u);
 852 }
 853
 854 static void unit_check_uneeded(Unit *u) {
 855         Iterator i;
 856         Unit *other;
 857
 858         assert(u);
 859
 860         /* If this service shall be shut down when unneeded then do
 861          * so. */
 862
 863         if (!u->meta.stop_when_unneeded)
 864                 return;
 865
 866         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 867                 return;
 868
 869         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 870                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 871                         return;
 872
 873         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 874                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 875                         return;
 876
 877         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 878                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 879                         return;
 880
 881         log_info("Service %s is not needed anymore. Stopping.", u->meta.id);
 882
 883         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 884         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL, NULL);
 885 }
 886
 887 static void retroactively_start_dependencies(Unit *u) {
 888         Iterator i;
 889         Unit *other;
 890
 891         assert(u);
 892         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 893
 894         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 895                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 896                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
 897
 898         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 899                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 900                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
 901
 902         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 903                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 904                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
 905
 906         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 907                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 908                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
 909
 910         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 911                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 912                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
 913 }
 914
 915 static void retroactively_stop_dependencies(Unit *u) {
 916         Iterator i;
 917         Unit *other;
 918
 919         assert(u);
 920         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 921
 922         if (u->meta.recursive_stop) {
 923                 /* Pull down units need us recursively if enabled */
 924                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 925                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 926                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
 927         }
 928
 929         /* Garbage collect services that might not be needed anymore, if enabled */
 930         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 931                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 932                         unit_check_uneeded(other);
 933         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 934                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 935                         unit_check_uneeded(other);
 936         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 937                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 938                         unit_check_uneeded(other);
 939         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 940                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 941                         unit_check_uneeded(other);
 942         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
 943                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 944                         unit_check_uneeded(other);
 945 }
 946
 947 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 948         dual_timestamp ts;
 949
 950         assert(u);
 951         assert(os < _UNIT_ACTIVE_STATE_MAX);
 952         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 953
 954         /* Note that this is called for all low-level state changes,
 955          * even if they might map to the same high-level
 956          * UnitActiveState! That means that ns == os is OK an expected
 957          * behaviour here. For example: if a mount point is remounted
 958          * this function will be called too and the utmp code below
 959          * relies on that! */
 960
 961         dual_timestamp_get(&ts);
 962
 963         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && !UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 964                 u->meta.inactive_exit_timestamp = ts;
 965         else if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 966                 u->meta.inactive_enter_timestamp = ts;
 967
 968         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 969                 u->meta.active_enter_timestamp = ts;
 970         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 971                 u->meta.active_exit_timestamp = ts;
 972
 973         timer_unit_notify(u, ns);
 974         path_unit_notify(u, ns);
 975
 976         if (u->meta.job) {
 977                 bool unexpected = false;
 978
 979                 if (u->meta.job->state == JOB_WAITING)
 980
 981                         /* So we reached a different state for this
 982                          * job. Let's see if we can run it now if it
 983                          * failed previously due to EAGAIN. */
 984                         job_add_to_run_queue(u->meta.job);
 985
 986
 987                 /* Let's check whether this state change constitutes a
 988                  * finished job, or maybe cotradicts a running job and
 989                  * hence needs to invalidate jobs. */
 990
 991                 switch (u->meta.job->type) {
 992
 993                 case JOB_START:
 994                 case JOB_VERIFY_ACTIVE:
 995
 996                         if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 997                                 job_finish_and_invalidate(u->meta.job, true);
 998                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
 999                                 unexpected = true;
1000                                 job_finish_and_invalidate(u->meta.job, false);
1001                         }
1002
1003                         break;
1004
1005                 case JOB_RELOAD:
1006                 case JOB_RELOAD_OR_START:
1007
1008                         if (u->meta.job->state == JOB_RUNNING) {
1009                                 if (ns == UNIT_ACTIVE)
1010                                         job_finish_and_invalidate(u->meta.job, true);
1011                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_RELOADING) {
1012                                         unexpected = true;
1013                                         job_finish_and_invalidate(u->meta.job, false);
1014                                 }
1015                         }
1016
1017                         break;
1018
1019                 case JOB_STOP:
1020                 case JOB_RESTART:
1021                 case JOB_TRY_RESTART:
1022
1023                         if (ns == UNIT_INACTIVE || ns == UNIT_MAINTENANCE)
1024                                 job_finish_and_invalidate(u->meta.job, true);
1025                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
1026                                 unexpected = true;
1027                                 job_finish_and_invalidate(u->meta.job, false);
1028                         }
1029
1030                         break;
1031
1032                 default:
1033                         assert_not_reached("Job type unknown");
1034                 }
1035
1036                 /* If this state change happened without being
1037                  * requested by a job, then let's retroactively start
1038                  * or stop dependencies */
1039
1040                 if (unexpected) {
1041                         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1042                                 retroactively_start_dependencies(u);
1043                         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1044                                 retroactively_stop_dependencies(u);
1045                 }
1046         }
1047
1048         /* Some names are special */
1049         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1050                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1051                         /* The bus just might have become available,
1052                          * hence try to connect to it, if we aren't
1053                          * yet connected. */
1054                         bus_init(u->meta.manager);
1055                 }
1056
1057                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1058                         /* The syslog daemon just might have become
1059                          * available, hence try to connect to it, if
1060                          * we aren't yet connected. */
1061                         log_open();
1062
1063                 if (u->meta.type == UNIT_MOUNT)
1064                         /* Another directory became available, let's
1065                          * check if that is enough to write our utmp
1066                          * entry. */
1067                         manager_write_utmp_reboot(u->meta.manager);
1068
1069                 if (u->meta.type == UNIT_TARGET)
1070                         /* A target got activated, maybe this is a runlevel? */
1071                         manager_write_utmp_runlevel(u->meta.manager, u);
1072
1073         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1074
1075                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1076                         /* The syslog daemon might just have
1077                          * terminated, hence try to disconnect from
1078                          * it. */
1079                         log_close_syslog();
1080
1081                 /* We don't care about D-Bus here, since we'll get an
1082                  * asynchronous notification for it anyway. */
1083         }
1084
1085         /* Maybe we finished startup and are now ready for being
1086          * stopped because unneeded? */
1087         unit_check_uneeded(u);
1088
1089         unit_add_to_dbus_queue(u);
1090         unit_add_to_gc_queue(u);
1091 }
1092
1093 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1094         struct epoll_event ev;
1095
1096         assert(u);
1097         assert(fd >= 0);
1098         assert(w);
1099         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1100
1101         zero(ev);
1102         ev.data.ptr = w;
1103         ev.events = events;
1104
1105         if (epoll_ctl(u->meta.manager->epoll_fd,
1106                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1107                       fd,
1108                       &ev) < 0)
1109                 return -errno;
1110
1111         w->fd = fd;
1112         w->type = WATCH_FD;
1113         w->data.unit = u;
1114
1115         return 0;
1116 }
1117
1118 void unit_unwatch_fd(Unit *u, Watch *w) {
1119         assert(u);
1120         assert(w);
1121
1122         if (w->type == WATCH_INVALID)
1123                 return;
1124
1125         assert(w->type == WATCH_FD);
1126         assert(w->data.unit == u);
1127         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1128
1129         w->fd = -1;
1130         w->type = WATCH_INVALID;
1131         w->data.unit = NULL;
1132 }
1133
1134 int unit_watch_pid(Unit *u, pid_t pid) {
1135         assert(u);
1136         assert(pid >= 1);
1137
1138         /* Watch a specific PID. We only support one unit watching
1139          * each PID for now. */
1140
1141         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1142 }
1143
1144 void unit_unwatch_pid(Unit *u, pid_t pid) {
1145         assert(u);
1146         assert(pid >= 1);
1147
1148         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1149 }
1150
1151 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1152         struct itimerspec its;
1153         int flags, fd;
1154         bool ours;
1155
1156         assert(u);
1157         assert(w);
1158         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1159
1160         /* This will try to reuse the old timer if there is one */
1161
1162         if (w->type == WATCH_TIMER) {
1163                 ours = false;
1164                 fd = w->fd;
1165         } else {
1166                 ours = true;
1167                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1168                         return -errno;
1169         }
1170
1171         zero(its);
1172
1173         if (delay <= 0) {
1174                 /* Set absolute time in the past, but not 0, since we
1175                  * don't want to disarm the timer */
1176                 its.it_value.tv_sec = 0;
1177                 its.it_value.tv_nsec = 1;
1178
1179                 flags = TFD_TIMER_ABSTIME;
1180         } else {
1181                 timespec_store(&its.it_value, delay);
1182                 flags = 0;
1183         }
1184
1185         /* This will also flush the elapse counter */
1186         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1187                 goto fail;
1188
1189         if (w->type == WATCH_INVALID) {
1190                 struct epoll_event ev;
1191
1192                 zero(ev);
1193                 ev.data.ptr = w;
1194                 ev.events = EPOLLIN;
1195
1196                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1197                         goto fail;
1198         }
1199
1200         w->fd = fd;
1201         w->type = WATCH_TIMER;
1202         w->data.unit = u;
1203
1204         return 0;
1205
1206 fail:
1207         if (ours)
1208                 close_nointr_nofail(fd);
1209
1210         return -errno;
1211 }
1212
1213 void unit_unwatch_timer(Unit *u, Watch *w) {
1214         assert(u);
1215         assert(w);
1216
1217         if (w->type == WATCH_INVALID)
1218                 return;
1219
1220         assert(w->type == WATCH_TIMER && w->data.unit == u);
1221
1222         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1223         close_nointr_nofail(w->fd);
1224
1225         w->fd = -1;
1226         w->type = WATCH_INVALID;
1227         w->data.unit = NULL;
1228 }
1229
1230 bool unit_job_is_applicable(Unit *u, JobType j) {
1231         assert(u);
1232         assert(j >= 0 && j < _JOB_TYPE_MAX);
1233
1234         switch (j) {
1235
1236         case JOB_VERIFY_ACTIVE:
1237         case JOB_START:
1238                 return true;
1239
1240         case JOB_STOP:
1241         case JOB_RESTART:
1242         case JOB_TRY_RESTART:
1243                 return unit_can_start(u);
1244
1245         case JOB_RELOAD:
1246                 return unit_can_reload(u);
1247
1248         case JOB_RELOAD_OR_START:
1249                 return unit_can_reload(u) && unit_can_start(u);
1250
1251         default:
1252                 assert_not_reached("Invalid job type");
1253         }
1254 }
1255
1256 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1257
1258         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1259                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1260                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1261                 [UNIT_WANTS] = UNIT_WANTED_BY,
1262                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1263                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1264                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1265                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1266                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1267                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1268                 [UNIT_BEFORE] = UNIT_AFTER,
1269                 [UNIT_AFTER] = UNIT_BEFORE,
1270                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1271                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1272         };
1273         int r, q = 0, v = 0, w = 0;
1274
1275         assert(u);
1276         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1277         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1278         assert(other);
1279
1280         /* We won't allow dependencies on ourselves. We will not
1281          * consider them an error however. */
1282         if (u == other)
1283                 return 0;
1284
1285         if (UNIT_VTABLE(u)->no_requires &&
1286             (d == UNIT_REQUIRES ||
1287              d == UNIT_REQUIRES_OVERRIDABLE ||
1288              d == UNIT_REQUISITE ||
1289              d == UNIT_REQUISITE_OVERRIDABLE)) {
1290                     return -EINVAL;
1291         }
1292
1293         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1294             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1295                 return r;
1296
1297         if (add_reference)
1298                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1299                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1300                         return r;
1301
1302         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1303                 return q;
1304
1305         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1306                 r = v;
1307                 goto fail;
1308         }
1309
1310         if (add_reference) {
1311                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1312                         r = w;
1313                         goto fail;
1314                 }
1315
1316                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1317                         goto fail;
1318         }
1319
1320         unit_add_to_dbus_queue(u);
1321         return 0;
1322
1323 fail:
1324         if (q > 0)
1325                 set_remove(u->meta.dependencies[d], other);
1326
1327         if (v > 0)
1328                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1329
1330         if (w > 0)
1331                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1332
1333         return r;
1334 }
1335
1336 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference) {
1337         int r;
1338
1339         assert(u);
1340
1341         if ((r = unit_add_dependency(u, d, other, add_reference)) < 0)
1342                 return r;
1343
1344         if ((r = unit_add_dependency(u, e, other, add_reference)) < 0)
1345                 return r;
1346
1347         return 0;
1348 }
1349
1350 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1351         char *s;
1352
1353         assert(u);
1354         assert(name || path);
1355
1356         if (!name)
1357                 name = file_name_from_path(path);
1358
1359         if (!unit_name_is_template(name)) {
1360                 *p = NULL;
1361                 return name;
1362         }
1363
1364         if (u->meta.instance)
1365                 s = unit_name_replace_instance(name, u->meta.instance);
1366         else {
1367                 char *i;
1368
1369                 if (!(i = unit_name_to_prefix(u->meta.id)))
1370                         return NULL;
1371
1372                 s = unit_name_replace_instance(name, i);
1373                 free(i);
1374         }
1375
1376         if (!s)
1377                 return NULL;
1378
1379         *p = s;
1380         return s;
1381 }
1382
1383 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1384         Unit *other;
1385         int r;
1386         char *s;
1387
1388         assert(u);
1389         assert(name || path);
1390
1391         if (!(name = resolve_template(u, name, path, &s)))
1392                 return -ENOMEM;
1393
1394         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1395                 goto finish;
1396
1397         r = unit_add_dependency(u, d, other, add_reference);
1398
1399 finish:
1400         free(s);
1401         return r;
1402 }
1403
1404 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1405         Unit *other;
1406         int r;
1407         char *s;
1408
1409         assert(u);
1410         assert(name || path);
1411
1412         if (!(name = resolve_template(u, name, path, &s)))
1413                 return -ENOMEM;
1414
1415         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1416                 goto finish;
1417
1418         r = unit_add_two_dependencies(u, d, e, other, add_reference);
1419
1420 finish:
1421         free(s);
1422         return r;
1423 }
1424
1425 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1426         Unit *other;
1427         int r;
1428         char *s;
1429
1430         assert(u);
1431         assert(name || path);
1432
1433         if (!(name = resolve_template(u, name, path, &s)))
1434                 return -ENOMEM;
1435
1436         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1437                 goto finish;
1438
1439         r = unit_add_dependency(other, d, u, add_reference);
1440
1441 finish:
1442         free(s);
1443         return r;
1444 }
1445
1446 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1447         Unit *other;
1448         int r;
1449         char *s;
1450
1451         assert(u);
1452         assert(name || path);
1453
1454         if (!(name = resolve_template(u, name, path, &s)))
1455                 return -ENOMEM;
1456
1457         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1458                 goto finish;
1459
1460         if ((r = unit_add_two_dependencies(other, d, e, u, add_reference)) < 0)
1461                 goto finish;
1462
1463 finish:
1464         free(s);
1465         return r;
1466 }
1467
1468 int set_unit_path(const char *p) {
1469         char *cwd, *c;
1470         int r;
1471
1472         /* This is mostly for debug purposes */
1473
1474         if (path_is_absolute(p)) {
1475                 if (!(c = strdup(p)))
1476                         return -ENOMEM;
1477         } else {
1478                 if (!(cwd = get_current_dir_name()))
1479                         return -errno;
1480
1481                 r = asprintf(&c, "%s/%s", cwd, p);
1482                 free(cwd);
1483
1484                 if (r < 0)
1485                         return -ENOMEM;
1486         }
1487
1488         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1489                 r = -errno;
1490                 free(c);
1491                 return r;
1492         }
1493
1494         return 0;
1495 }
1496
1497 char *unit_dbus_path(Unit *u) {
1498         char *p, *e;
1499
1500         assert(u);
1501
1502         if (!(e = bus_path_escape(u->meta.id)))
1503                 return NULL;
1504
1505         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1506                 free(e);
1507                 return NULL;
1508         }
1509
1510         free(e);
1511         return p;
1512 }
1513
1514 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1515         CGroupBonding *l;
1516         int r;
1517
1518         assert(u);
1519         assert(b);
1520         assert(b->path);
1521
1522         /* Ensure this hasn't been added yet */
1523         assert(!b->unit);
1524
1525         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1526         LIST_PREPEND(CGroupBonding, by_path, l, b);
1527
1528         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1529                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1530                 return r;
1531         }
1532
1533         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1534         b->unit = u;
1535
1536         return 0;
1537 }
1538
1539 static char *default_cgroup_path(Unit *u) {
1540         char *p;
1541         int r;
1542
1543         assert(u);
1544
1545         if (u->meta.instance) {
1546                 char *t;
1547
1548                 if (!(t = unit_name_template(u->meta.id)))
1549                         return NULL;
1550
1551                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1552                 free(t);
1553         } else
1554                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1555
1556         return r < 0 ? NULL : p;
1557 }
1558
1559 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1560         size_t n;
1561         char *controller = NULL, *path = NULL;
1562         CGroupBonding *b = NULL;
1563         int r;
1564
1565         assert(u);
1566         assert(name);
1567
1568         /* Detect controller name */
1569         n = strcspn(name, ":");
1570
1571         if (name[n] == 0 ||
1572             (name[n] == ':' && name[n+1] == 0)) {
1573
1574                 /* Only controller name, no path? */
1575
1576                 if (!(path = default_cgroup_path(u)))
1577                         return -ENOMEM;
1578
1579         } else {
1580                 const char *p;
1581
1582                 /* Controller name, and path. */
1583                 p = name+n+1;
1584
1585                 if (!path_is_absolute(p))
1586                         return -EINVAL;
1587
1588                 if (!(path = strdup(p)))
1589                         return -ENOMEM;
1590         }
1591
1592         if (n > 0)
1593                 controller = strndup(name, n);
1594         else
1595                 controller = strdup(u->meta.manager->cgroup_controller);
1596
1597         if (!controller) {
1598                 r = -ENOMEM;
1599                 goto fail;
1600         }
1601
1602         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1603                 r = -EEXIST;
1604                 goto fail;
1605         }
1606
1607         if (!(b = new0(CGroupBonding, 1))) {
1608                 r = -ENOMEM;
1609                 goto fail;
1610         }
1611
1612         b->controller = controller;
1613         b->path = path;
1614         b->only_us = false;
1615         b->clean_up = false;
1616
1617         if ((r = unit_add_cgroup(u, b)) < 0)
1618                 goto fail;
1619
1620         return 0;
1621
1622 fail:
1623         free(path);
1624         free(controller);
1625         free(b);
1626
1627         return r;
1628 }
1629
1630 int unit_add_default_cgroup(Unit *u) {
1631         CGroupBonding *b;
1632         int r = -ENOMEM;
1633
1634         assert(u);
1635
1636         /* Adds in the default cgroup data, if it wasn't specified yet */
1637
1638         if (unit_get_default_cgroup(u))
1639                 return 0;
1640
1641         if (!(b = new0(CGroupBonding, 1)))
1642                 return -ENOMEM;
1643
1644         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1645                 goto fail;
1646
1647         if (!(b->path = default_cgroup_path(u)))
1648                 goto fail;
1649
1650         b->clean_up = true;
1651         b->only_us = true;
1652
1653         if ((r = unit_add_cgroup(u, b)) < 0)
1654                 goto fail;
1655
1656         return 0;
1657
1658 fail:
1659         free(b->path);
1660         free(b->controller);
1661         free(b);
1662
1663         return r;
1664 }
1665
1666 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1667         assert(u);
1668
1669         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1670 }
1671
1672 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1673         char *t;
1674         int r;
1675
1676         assert(u);
1677         assert(type);
1678         assert(_found);
1679
1680         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1681                 return -ENOMEM;
1682
1683         assert(!unit_has_name(u, t));
1684
1685         r = manager_load_unit(u->meta.manager, t, NULL, NULL, _found);
1686         free(t);
1687
1688         assert(r < 0 || *_found != u);
1689
1690         return r;
1691 }
1692
1693 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1694         Unit *found;
1695         char *t;
1696
1697         assert(u);
1698         assert(type);
1699         assert(_found);
1700
1701         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1702                 return -ENOMEM;
1703
1704         assert(!unit_has_name(u, t));
1705
1706         found = manager_get_unit(u->meta.manager, t);
1707         free(t);
1708
1709         if (!found)
1710                 return -ENOENT;
1711
1712         *_found = found;
1713         return 0;
1714 }
1715
1716 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1717         Unit *u = userdata;
1718         assert(u);
1719
1720         return unit_name_to_prefix_and_instance(u->meta.id);
1721 }
1722
1723 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1724         Unit *u = userdata;
1725         assert(u);
1726
1727         return unit_name_to_prefix(u->meta.id);
1728 }
1729
1730 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1731         Unit *u = userdata;
1732         char *p, *r;
1733
1734         assert(u);
1735
1736         if (!(p = unit_name_to_prefix(u->meta.id)))
1737                 return NULL;
1738
1739         r = unit_name_unescape(p);
1740         free(p);
1741
1742         return r;
1743 }
1744
1745 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1746         Unit *u = userdata;
1747         assert(u);
1748
1749         if (u->meta.instance)
1750                 return unit_name_unescape(u->meta.instance);
1751
1752         return strdup("");
1753 }
1754
1755 char *unit_name_printf(Unit *u, const char* format) {
1756
1757         /*
1758          * This will use the passed string as format string and
1759          * replace the following specifiers:
1760          *
1761          * %n: the full id of the unit                 (foo@bar.waldo)
1762          * %N: the id of the unit without the suffix   (foo@bar)
1763          * %p: the prefix                              (foo)
1764          * %i: the instance                            (bar)
1765          */
1766
1767         const Specifier table[] = {
1768                 { 'n', specifier_string,              u->meta.id },
1769                 { 'N', specifier_prefix_and_instance, NULL },
1770                 { 'p', specifier_prefix,              NULL },
1771                 { 'i', specifier_string,              u->meta.instance },
1772                 { 0, NULL, NULL }
1773         };
1774
1775         assert(u);
1776         assert(format);
1777
1778         return specifier_printf(format, table, u);
1779 }
1780
1781 char *unit_full_printf(Unit *u, const char *format) {
1782
1783         /* This is similar to unit_name_printf() but also supports
1784          * unescaping */
1785
1786         const Specifier table[] = {
1787                 { 'n', specifier_string,              u->meta.id },
1788                 { 'N', specifier_prefix_and_instance, NULL },
1789                 { 'p', specifier_prefix,              NULL },
1790                 { 'P', specifier_prefix_unescaped,    NULL },
1791                 { 'i', specifier_string,              u->meta.instance },
1792                 { 'I', specifier_instance_unescaped,  NULL },
1793                 { 0, NULL, NULL }
1794         };
1795
1796         assert(u);
1797         assert(format);
1798
1799         return specifier_printf(format, table, u);
1800 }
1801
1802 char **unit_full_printf_strv(Unit *u, char **l) {
1803         size_t n;
1804         char **r, **i, **j;
1805
1806         /* Applies unit_full_printf to every entry in l */
1807
1808         assert(u);
1809
1810         n = strv_length(l);
1811         if (!(r = new(char*, n+1)))
1812                 return NULL;
1813
1814         for (i = l, j = r; *i; i++, j++)
1815                 if (!(*j = unit_full_printf(u, *i)))
1816                         goto fail;
1817
1818         *j = NULL;
1819         return r;
1820
1821 fail:
1822         j--;
1823         while (j >= r)
1824                 free(*j);
1825
1826         free(r);
1827
1828         return NULL;
1829 }
1830
1831 int unit_watch_bus_name(Unit *u, const char *name) {
1832         assert(u);
1833         assert(name);
1834
1835         /* Watch a specific name on the bus. We only support one unit
1836          * watching each name for now. */
1837
1838         return hashmap_put(u->meta.manager->watch_bus, name, u);
1839 }
1840
1841 void unit_unwatch_bus_name(Unit *u, const char *name) {
1842         assert(u);
1843         assert(name);
1844
1845         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1846 }
1847
1848 bool unit_can_serialize(Unit *u) {
1849         assert(u);
1850
1851         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1852 }
1853
1854 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1855         int r;
1856
1857         assert(u);
1858         assert(f);
1859         assert(fds);
1860
1861         if (!unit_can_serialize(u))
1862                 return 0;
1863
1864         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1865                 return r;
1866
1867         if (u->meta.job)
1868                 unit_serialize_item(u, f, "job", job_type_to_string(u->meta.job->type));
1869
1870         /* End marker */
1871         fputc('\n', f);
1872         return 0;
1873 }
1874
1875 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1876         va_list ap;
1877
1878         assert(u);
1879         assert(f);
1880         assert(key);
1881         assert(format);
1882
1883         fputs(key, f);
1884         fputc('=', f);
1885
1886         va_start(ap, format);
1887         vfprintf(f, format, ap);
1888         va_end(ap);
1889
1890         fputc('\n', f);
1891 }
1892
1893 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1894         assert(u);
1895         assert(f);
1896         assert(key);
1897         assert(value);
1898
1899         fprintf(f, "%s=%s\n", key, value);
1900 }
1901
1902 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1903         int r;
1904
1905         assert(u);
1906         assert(f);
1907         assert(fds);
1908
1909         if (!unit_can_serialize(u))
1910                 return 0;
1911
1912         for (;;) {
1913                 char line[1024], *l, *v;
1914                 size_t k;
1915
1916                 if (!fgets(line, sizeof(line), f)) {
1917                         if (feof(f))
1918                                 return 0;
1919                         return -errno;
1920                 }
1921
1922                 l = strstrip(line);
1923
1924                 /* End marker */
1925                 if (l[0] == 0)
1926                         return 0;
1927
1928                 k = strcspn(l, "=");
1929
1930                 if (l[k] == '=') {
1931                         l[k] = 0;
1932                         v = l+k+1;
1933                 } else
1934                         v = l+k;
1935
1936                 if (streq(l, "job")) {
1937                         JobType type;
1938
1939                         if ((type = job_type_from_string(v)) < 0)
1940                                 log_debug("Failed to parse job type value %s", v);
1941                         else
1942                                 u->meta.deserialized_job = type;
1943
1944                         continue;
1945                 }
1946
1947                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1948                         return r;
1949         }
1950 }
1951
1952 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1953         Unit *device;
1954         char *e;
1955         int r;
1956
1957         assert(u);
1958
1959         if (!what)
1960                 return 0;
1961
1962         /* Adds in links to the device node that this unit is based on */
1963
1964         if (!is_device_path(what))
1965                 return 0;
1966
1967         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1968                 return -ENOMEM;
1969
1970         r = manager_load_unit(u->meta.manager, e, NULL, NULL, &device);
1971         free(e);
1972
1973         if (r < 0)
1974                 return r;
1975
1976         if ((r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_REQUIRES, device, true)) < 0)
1977                 return r;
1978
1979         if (wants)
1980                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1981                         return r;
1982
1983         return 0;
1984 }
1985
1986 int unit_coldplug(Unit *u) {
1987         int r;
1988
1989         assert(u);
1990
1991         if (UNIT_VTABLE(u)->coldplug)
1992                 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
1993                         return r;
1994
1995         if (u->meta.deserialized_job >= 0) {
1996                 if ((r = manager_add_job(u->meta.manager, u->meta.deserialized_job, u, JOB_FAIL, false, NULL, NULL)) < 0)
1997                         return r;
1998
1999                 u->meta.deserialized_job = _JOB_TYPE_INVALID;
2000         }
2001
2002         return 0;
2003 }
2004
2005 void unit_status_printf(Unit *u, const char *format, ...) {
2006         va_list ap;
2007
2008         assert(u);
2009         assert(format);
2010
2011         if (!UNIT_VTABLE(u)->show_status)
2012                 return;
2013
2014         if (u->meta.manager->running_as != MANAGER_SYSTEM)
2015                 return;
2016
2017         if (!u->meta.manager->show_status)
2018                 return;
2019
2020         if (!manager_is_booting_or_shutting_down(u->meta.manager))
2021                 return;
2022
2023         va_start(ap, format);
2024         status_vprintf(format, ap);
2025         va_end(ap);
2026 }
2027
2028 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
2029         [UNIT_SERVICE] = "service",
2030         [UNIT_TIMER] = "timer",
2031         [UNIT_SOCKET] = "socket",
2032         [UNIT_TARGET] = "target",
2033         [UNIT_DEVICE] = "device",
2034         [UNIT_MOUNT] = "mount",
2035         [UNIT_AUTOMOUNT] = "automount",
2036         [UNIT_SNAPSHOT] = "snapshot",
2037         [UNIT_SWAP] = "swap"
2038 };
2039
2040 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
2041
2042 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
2043         [UNIT_STUB] = "stub",
2044         [UNIT_LOADED] = "loaded",
2045         [UNIT_FAILED] = "failed",
2046         [UNIT_MERGED] = "merged"
2047 };
2048
2049 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
2050
2051 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
2052         [UNIT_ACTIVE] = "active",
2053         [UNIT_RELOADING] = "reloading",
2054         [UNIT_INACTIVE] = "inactive",
2055         [UNIT_MAINTENANCE] = "maintenance",
2056         [UNIT_ACTIVATING] = "activating",
2057         [UNIT_DEACTIVATING] = "deactivating"
2058 };
2059
2060 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
2061
2062 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
2063         [UNIT_REQUIRES] = "Requires",
2064         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
2065         [UNIT_WANTS] = "Wants",
2066         [UNIT_REQUISITE] = "Requisite",
2067         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
2068         [UNIT_REQUIRED_BY] = "RequiredBy",
2069         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
2070         [UNIT_WANTED_BY] = "WantedBy",
2071         [UNIT_CONFLICTS] = "Conflicts",
2072         [UNIT_BEFORE] = "Before",
2073         [UNIT_AFTER] = "After",
2074         [UNIT_REFERENCES] = "References",
2075         [UNIT_REFERENCED_BY] = "ReferencedBy"
2076 };
2077
2078 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
2079
2080 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
2081         [KILL_CONTROL_GROUP] = "control-group",
2082         [KILL_PROCESS_GROUP] = "process-group",
2083         [KILL_PROCESS] = "process",
2084         [KILL_NONE] = "none"
2085 };
2086
2087 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);