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