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_debug("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         return UNIT_VTABLE(u)->start(u);
 780 }
 781
 782 bool unit_can_start(Unit *u) {
 783         assert(u);
 784
 785         return !!UNIT_VTABLE(u)->start;
 786 }
 787
 788 /* Errors:
 789  *         -EBADR:    This unit type does not support stopping.
 790  *         -EALREADY: Unit is already stopped.
 791  *         -EAGAIN:   An operation is already in progress. Retry later.
 792  */
 793 int unit_stop(Unit *u) {
 794         UnitActiveState state;
 795
 796         assert(u);
 797
 798         state = unit_active_state(u);
 799         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(state))
 800                 return -EALREADY;
 801
 802         if (!UNIT_VTABLE(u)->stop)
 803                 return -EBADR;
 804
 805         unit_add_to_dbus_queue(u);
 806         return UNIT_VTABLE(u)->stop(u);
 807 }
 808
 809 /* Errors:
 810  *         -EBADR:    This unit type does not support reloading.
 811  *         -ENOEXEC:  Unit is not started.
 812  *         -EAGAIN:   An operation is already in progress. Retry later.
 813  */
 814 int unit_reload(Unit *u) {
 815         UnitActiveState state;
 816
 817         assert(u);
 818
 819         if (u->meta.load_state != UNIT_LOADED)
 820                 return -EINVAL;
 821
 822         if (!unit_can_reload(u))
 823                 return -EBADR;
 824
 825         state = unit_active_state(u);
 826         if (unit_active_state(u) == UNIT_RELOADING)
 827                 return -EALREADY;
 828
 829         if (unit_active_state(u) != UNIT_ACTIVE)
 830                 return -ENOEXEC;
 831
 832         unit_add_to_dbus_queue(u);
 833         return UNIT_VTABLE(u)->reload(u);
 834 }
 835
 836 bool unit_can_reload(Unit *u) {
 837         assert(u);
 838
 839         if (!UNIT_VTABLE(u)->reload)
 840                 return false;
 841
 842         if (!UNIT_VTABLE(u)->can_reload)
 843                 return true;
 844
 845         return UNIT_VTABLE(u)->can_reload(u);
 846 }
 847
 848 static void unit_check_uneeded(Unit *u) {
 849         Iterator i;
 850         Unit *other;
 851
 852         assert(u);
 853
 854         /* If this service shall be shut down when unneeded then do
 855          * so. */
 856
 857         if (!u->meta.stop_when_unneeded)
 858                 return;
 859
 860         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 861                 return;
 862
 863         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 864                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 865                         return;
 866
 867         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 868                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 869                         return;
 870
 871         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 872                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 873                         return;
 874
 875         log_debug("Service %s is not needed anymore. Stopping.", u->meta.id);
 876
 877         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 878         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 879 }
 880
 881 static void retroactively_start_dependencies(Unit *u) {
 882         Iterator i;
 883         Unit *other;
 884
 885         assert(u);
 886         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 887
 888         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 889                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 890                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 891
 892         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 893                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 894                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 895
 896         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 897                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 898                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 899
 900         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 901                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 902                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 903
 904         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 905                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 906                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 907 }
 908
 909 static void retroactively_stop_dependencies(Unit *u) {
 910         Iterator i;
 911         Unit *other;
 912
 913         assert(u);
 914         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 915
 916         if (u->meta.recursive_stop) {
 917                 /* Pull down units need us recursively if enabled */
 918                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 919                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 920                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 921         }
 922
 923         /* Garbage collect services that might not be needed anymore, if enabled */
 924         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 925                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 926                         unit_check_uneeded(other);
 927         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 928                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 929                         unit_check_uneeded(other);
 930         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], 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_REQUISITE], 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_REQUISITE_OVERRIDABLE], i)
 937                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 938                         unit_check_uneeded(other);
 939 }
 940
 941 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 942         bool unexpected = false;
 943         dual_timestamp ts;
 944
 945         assert(u);
 946         assert(os < _UNIT_ACTIVE_STATE_MAX);
 947         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 948
 949         /* Note that this is called for all low-level state changes,
 950          * even if they might map to the same high-level
 951          * UnitActiveState! That means that ns == os is OK an expected
 952          * behaviour here. For example: if a mount point is remounted
 953          * this function will be called too and the utmp code below
 954          * relies on that! */
 955
 956         dual_timestamp_get(&ts);
 957
 958         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && !UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 959                 u->meta.inactive_exit_timestamp = ts;
 960         else if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
 961                 u->meta.inactive_enter_timestamp = ts;
 962
 963         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 964                 u->meta.active_enter_timestamp = ts;
 965         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 966                 u->meta.active_exit_timestamp = ts;
 967
 968         timer_unit_notify(u, ns);
 969         path_unit_notify(u, ns);
 970
 971         if (u->meta.job) {
 972
 973                 if (u->meta.job->state == JOB_WAITING)
 974
 975                         /* So we reached a different state for this
 976                          * job. Let's see if we can run it now if it
 977                          * failed previously due to EAGAIN. */
 978                         job_add_to_run_queue(u->meta.job);
 979
 980
 981                 /* Let's check whether this state change constitutes a
 982                  * finished job, or maybe cotradicts a running job and
 983                  * hence needs to invalidate jobs. */
 984
 985                 switch (u->meta.job->type) {
 986
 987                 case JOB_START:
 988                 case JOB_VERIFY_ACTIVE:
 989
 990                         if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 991                                 job_finish_and_invalidate(u->meta.job, true);
 992                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
 993                                 unexpected = true;
 994                                 job_finish_and_invalidate(u->meta.job, false);
 995                         }
 996
 997                         break;
 998
 999                 case JOB_RELOAD:
1000                 case JOB_RELOAD_OR_START:
1001
1002                         if (u->meta.job->state == JOB_RUNNING) {
1003                                 if (ns == UNIT_ACTIVE)
1004                                         job_finish_and_invalidate(u->meta.job, true);
1005                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_RELOADING) {
1006                                         unexpected = true;
1007                                         job_finish_and_invalidate(u->meta.job, false);
1008                                 }
1009                         }
1010
1011                         break;
1012
1013                 case JOB_STOP:
1014                 case JOB_RESTART:
1015                 case JOB_TRY_RESTART:
1016
1017                         if (ns == UNIT_INACTIVE)
1018                                 job_finish_and_invalidate(u->meta.job, true);
1019                         else if (ns == UNIT_MAINTENANCE)
1020                                 job_finish_and_invalidate(u->meta.job, false);
1021                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
1022                                 unexpected = true;
1023                                 job_finish_and_invalidate(u->meta.job, false);
1024                         }
1025
1026                         break;
1027
1028                 default:
1029                         assert_not_reached("Job type unknown");
1030                 }
1031         }
1032
1033         /* If this state change happened without being requested by a
1034          * job, then let's retroactively start or stop dependencies */
1035
1036         if (unexpected) {
1037                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1038                         retroactively_start_dependencies(u);
1039                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1040                         retroactively_stop_dependencies(u);
1041         }
1042
1043         /* Some names are special */
1044         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1045                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1046                         /* The bus just might have become available,
1047                          * hence try to connect to it, if we aren't
1048                          * yet connected. */
1049                         bus_init(u->meta.manager);
1050                 }
1051
1052                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1053                         /* The syslog daemon just might have become
1054                          * available, hence try to connect to it, if
1055                          * we aren't yet connected. */
1056                         log_open();
1057
1058                 if (u->meta.type == UNIT_MOUNT)
1059                         /* Another directory became available, let's
1060                          * check if that is enough to write our utmp
1061                          * entry. */
1062                         manager_write_utmp_reboot(u->meta.manager);
1063
1064                 if (u->meta.type == UNIT_TARGET)
1065                         /* A target got activated, maybe this is a runlevel? */
1066                         manager_write_utmp_runlevel(u->meta.manager, u);
1067
1068         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1069
1070                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1071                         /* The syslog daemon might just have
1072                          * terminated, hence try to disconnect from
1073                          * it. */
1074                         log_close_syslog();
1075
1076                 /* We don't care about D-Bus here, since we'll get an
1077                  * asynchronous notification for it anyway. */
1078         }
1079
1080         /* Maybe we finished startup and are now ready for being
1081          * stopped because unneeded? */
1082         unit_check_uneeded(u);
1083
1084         unit_add_to_dbus_queue(u);
1085         unit_add_to_gc_queue(u);
1086 }
1087
1088 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1089         struct epoll_event ev;
1090
1091         assert(u);
1092         assert(fd >= 0);
1093         assert(w);
1094         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1095
1096         zero(ev);
1097         ev.data.ptr = w;
1098         ev.events = events;
1099
1100         if (epoll_ctl(u->meta.manager->epoll_fd,
1101                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1102                       fd,
1103                       &ev) < 0)
1104                 return -errno;
1105
1106         w->fd = fd;
1107         w->type = WATCH_FD;
1108         w->data.unit = u;
1109
1110         return 0;
1111 }
1112
1113 void unit_unwatch_fd(Unit *u, Watch *w) {
1114         assert(u);
1115         assert(w);
1116
1117         if (w->type == WATCH_INVALID)
1118                 return;
1119
1120         assert(w->type == WATCH_FD);
1121         assert(w->data.unit == u);
1122         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1123
1124         w->fd = -1;
1125         w->type = WATCH_INVALID;
1126         w->data.unit = NULL;
1127 }
1128
1129 int unit_watch_pid(Unit *u, pid_t pid) {
1130         assert(u);
1131         assert(pid >= 1);
1132
1133         /* Watch a specific PID. We only support one unit watching
1134          * each PID for now. */
1135
1136         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1137 }
1138
1139 void unit_unwatch_pid(Unit *u, pid_t pid) {
1140         assert(u);
1141         assert(pid >= 1);
1142
1143         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1144 }
1145
1146 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1147         struct itimerspec its;
1148         int flags, fd;
1149         bool ours;
1150
1151         assert(u);
1152         assert(w);
1153         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1154
1155         /* This will try to reuse the old timer if there is one */
1156
1157         if (w->type == WATCH_TIMER) {
1158                 ours = false;
1159                 fd = w->fd;
1160         } else {
1161                 ours = true;
1162                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1163                         return -errno;
1164         }
1165
1166         zero(its);
1167
1168         if (delay <= 0) {
1169                 /* Set absolute time in the past, but not 0, since we
1170                  * don't want to disarm the timer */
1171                 its.it_value.tv_sec = 0;
1172                 its.it_value.tv_nsec = 1;
1173
1174                 flags = TFD_TIMER_ABSTIME;
1175         } else {
1176                 timespec_store(&its.it_value, delay);
1177                 flags = 0;
1178         }
1179
1180         /* This will also flush the elapse counter */
1181         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1182                 goto fail;
1183
1184         if (w->type == WATCH_INVALID) {
1185                 struct epoll_event ev;
1186
1187                 zero(ev);
1188                 ev.data.ptr = w;
1189                 ev.events = EPOLLIN;
1190
1191                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1192                         goto fail;
1193         }
1194
1195         w->fd = fd;
1196         w->type = WATCH_TIMER;
1197         w->data.unit = u;
1198
1199         return 0;
1200
1201 fail:
1202         if (ours)
1203                 close_nointr_nofail(fd);
1204
1205         return -errno;
1206 }
1207
1208 void unit_unwatch_timer(Unit *u, Watch *w) {
1209         assert(u);
1210         assert(w);
1211
1212         if (w->type == WATCH_INVALID)
1213                 return;
1214
1215         assert(w->type == WATCH_TIMER && w->data.unit == u);
1216
1217         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1218         close_nointr_nofail(w->fd);
1219
1220         w->fd = -1;
1221         w->type = WATCH_INVALID;
1222         w->data.unit = NULL;
1223 }
1224
1225 bool unit_job_is_applicable(Unit *u, JobType j) {
1226         assert(u);
1227         assert(j >= 0 && j < _JOB_TYPE_MAX);
1228
1229         switch (j) {
1230
1231         case JOB_VERIFY_ACTIVE:
1232         case JOB_START:
1233                 return true;
1234
1235         case JOB_STOP:
1236         case JOB_RESTART:
1237         case JOB_TRY_RESTART:
1238                 return unit_can_start(u);
1239
1240         case JOB_RELOAD:
1241                 return unit_can_reload(u);
1242
1243         case JOB_RELOAD_OR_START:
1244                 return unit_can_reload(u) && unit_can_start(u);
1245
1246         default:
1247                 assert_not_reached("Invalid job type");
1248         }
1249 }
1250
1251 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1252
1253         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1254                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1255                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1256                 [UNIT_WANTS] = UNIT_WANTED_BY,
1257                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1258                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1259                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1260                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1261                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1262                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1263                 [UNIT_BEFORE] = UNIT_AFTER,
1264                 [UNIT_AFTER] = UNIT_BEFORE,
1265                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1266                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1267         };
1268         int r, q = 0, v = 0, w = 0;
1269
1270         assert(u);
1271         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1272         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1273         assert(other);
1274
1275         /* We won't allow dependencies on ourselves. We will not
1276          * consider them an error however. */
1277         if (u == other)
1278                 return 0;
1279
1280         if (UNIT_VTABLE(u)->no_requires &&
1281             (d == UNIT_REQUIRES ||
1282              d == UNIT_REQUIRES_OVERRIDABLE ||
1283              d == UNIT_REQUISITE ||
1284              d == UNIT_REQUISITE_OVERRIDABLE)) {
1285                     return -EINVAL;
1286         }
1287
1288         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1289             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1290                 return r;
1291
1292         if (add_reference)
1293                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1294                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1295                         return r;
1296
1297         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1298                 return q;
1299
1300         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1301                 r = v;
1302                 goto fail;
1303         }
1304
1305         if (add_reference) {
1306                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1307                         r = w;
1308                         goto fail;
1309                 }
1310
1311                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1312                         goto fail;
1313         }
1314
1315         unit_add_to_dbus_queue(u);
1316         return 0;
1317
1318 fail:
1319         if (q > 0)
1320                 set_remove(u->meta.dependencies[d], other);
1321
1322         if (v > 0)
1323                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1324
1325         if (w > 0)
1326                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1327
1328         return r;
1329 }
1330
1331 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference) {
1332         int r;
1333
1334         assert(u);
1335
1336         if ((r = unit_add_dependency(u, d, other, add_reference)) < 0)
1337                 return r;
1338
1339         if ((r = unit_add_dependency(u, e, other, add_reference)) < 0)
1340                 return r;
1341
1342         return 0;
1343 }
1344
1345 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1346         char *s;
1347
1348         assert(u);
1349         assert(name || path);
1350
1351         if (!name)
1352                 name = file_name_from_path(path);
1353
1354         if (!unit_name_is_template(name)) {
1355                 *p = NULL;
1356                 return name;
1357         }
1358
1359         if (u->meta.instance)
1360                 s = unit_name_replace_instance(name, u->meta.instance);
1361         else {
1362                 char *i;
1363
1364                 if (!(i = unit_name_to_prefix(u->meta.id)))
1365                         return NULL;
1366
1367                 s = unit_name_replace_instance(name, i);
1368                 free(i);
1369         }
1370
1371         if (!s)
1372                 return NULL;
1373
1374         *p = s;
1375         return s;
1376 }
1377
1378 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1379         Unit *other;
1380         int r;
1381         char *s;
1382
1383         assert(u);
1384         assert(name || path);
1385
1386         if (!(name = resolve_template(u, name, path, &s)))
1387                 return -ENOMEM;
1388
1389         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1390                 goto finish;
1391
1392         r = unit_add_dependency(u, d, other, add_reference);
1393
1394 finish:
1395         free(s);
1396         return r;
1397 }
1398
1399 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1400         Unit *other;
1401         int r;
1402         char *s;
1403
1404         assert(u);
1405         assert(name || path);
1406
1407         if (!(name = resolve_template(u, name, path, &s)))
1408                 return -ENOMEM;
1409
1410         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1411                 goto finish;
1412
1413         r = unit_add_two_dependencies(u, d, e, other, add_reference);
1414
1415 finish:
1416         free(s);
1417         return r;
1418 }
1419
1420 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1421         Unit *other;
1422         int r;
1423         char *s;
1424
1425         assert(u);
1426         assert(name || path);
1427
1428         if (!(name = resolve_template(u, name, path, &s)))
1429                 return -ENOMEM;
1430
1431         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1432                 goto finish;
1433
1434         r = unit_add_dependency(other, d, u, add_reference);
1435
1436 finish:
1437         free(s);
1438         return r;
1439 }
1440
1441 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1442         Unit *other;
1443         int r;
1444         char *s;
1445
1446         assert(u);
1447         assert(name || path);
1448
1449         if (!(name = resolve_template(u, name, path, &s)))
1450                 return -ENOMEM;
1451
1452         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1453                 goto finish;
1454
1455         if ((r = unit_add_two_dependencies(other, d, e, u, add_reference)) < 0)
1456                 goto finish;
1457
1458 finish:
1459         free(s);
1460         return r;
1461 }
1462
1463 int set_unit_path(const char *p) {
1464         char *cwd, *c;
1465         int r;
1466
1467         /* This is mostly for debug purposes */
1468
1469         if (path_is_absolute(p)) {
1470                 if (!(c = strdup(p)))
1471                         return -ENOMEM;
1472         } else {
1473                 if (!(cwd = get_current_dir_name()))
1474                         return -errno;
1475
1476                 r = asprintf(&c, "%s/%s", cwd, p);
1477                 free(cwd);
1478
1479                 if (r < 0)
1480                         return -ENOMEM;
1481         }
1482
1483         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1484                 r = -errno;
1485                 free(c);
1486                 return r;
1487         }
1488
1489         return 0;
1490 }
1491
1492 char *unit_dbus_path(Unit *u) {
1493         char *p, *e;
1494
1495         assert(u);
1496
1497         if (!(e = bus_path_escape(u->meta.id)))
1498                 return NULL;
1499
1500         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1501                 free(e);
1502                 return NULL;
1503         }
1504
1505         free(e);
1506         return p;
1507 }
1508
1509 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1510         CGroupBonding *l;
1511         int r;
1512
1513         assert(u);
1514         assert(b);
1515         assert(b->path);
1516
1517         /* Ensure this hasn't been added yet */
1518         assert(!b->unit);
1519
1520         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1521         LIST_PREPEND(CGroupBonding, by_path, l, b);
1522
1523         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1524                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1525                 return r;
1526         }
1527
1528         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1529         b->unit = u;
1530
1531         return 0;
1532 }
1533
1534 static char *default_cgroup_path(Unit *u) {
1535         char *p;
1536         int r;
1537
1538         assert(u);
1539
1540         if (u->meta.instance) {
1541                 char *t;
1542
1543                 if (!(t = unit_name_template(u->meta.id)))
1544                         return NULL;
1545
1546                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1547                 free(t);
1548         } else
1549                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1550
1551         return r < 0 ? NULL : p;
1552 }
1553
1554 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1555         size_t n;
1556         char *controller = NULL, *path = NULL;
1557         CGroupBonding *b = NULL;
1558         int r;
1559
1560         assert(u);
1561         assert(name);
1562
1563         /* Detect controller name */
1564         n = strcspn(name, ":");
1565
1566         if (name[n] == 0 ||
1567             (name[n] == ':' && name[n+1] == 0)) {
1568
1569                 /* Only controller name, no path? */
1570
1571                 if (!(path = default_cgroup_path(u)))
1572                         return -ENOMEM;
1573
1574         } else {
1575                 const char *p;
1576
1577                 /* Controller name, and path. */
1578                 p = name+n+1;
1579
1580                 if (!path_is_absolute(p))
1581                         return -EINVAL;
1582
1583                 if (!(path = strdup(p)))
1584                         return -ENOMEM;
1585         }
1586
1587         if (n > 0)
1588                 controller = strndup(name, n);
1589         else
1590                 controller = strdup(u->meta.manager->cgroup_controller);
1591
1592         if (!controller) {
1593                 r = -ENOMEM;
1594                 goto fail;
1595         }
1596
1597         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1598                 r = -EEXIST;
1599                 goto fail;
1600         }
1601
1602         if (!(b = new0(CGroupBonding, 1))) {
1603                 r = -ENOMEM;
1604                 goto fail;
1605         }
1606
1607         b->controller = controller;
1608         b->path = path;
1609         b->only_us = false;
1610         b->clean_up = false;
1611
1612         if ((r = unit_add_cgroup(u, b)) < 0)
1613                 goto fail;
1614
1615         return 0;
1616
1617 fail:
1618         free(path);
1619         free(controller);
1620         free(b);
1621
1622         return r;
1623 }
1624
1625 int unit_add_default_cgroup(Unit *u) {
1626         CGroupBonding *b;
1627         int r = -ENOMEM;
1628
1629         assert(u);
1630
1631         /* Adds in the default cgroup data, if it wasn't specified yet */
1632
1633         if (unit_get_default_cgroup(u))
1634                 return 0;
1635
1636         if (!(b = new0(CGroupBonding, 1)))
1637                 return -ENOMEM;
1638
1639         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1640                 goto fail;
1641
1642         if (!(b->path = default_cgroup_path(u)))
1643                 goto fail;
1644
1645         b->clean_up = true;
1646         b->only_us = true;
1647
1648         if ((r = unit_add_cgroup(u, b)) < 0)
1649                 goto fail;
1650
1651         return 0;
1652
1653 fail:
1654         free(b->path);
1655         free(b->controller);
1656         free(b);
1657
1658         return r;
1659 }
1660
1661 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1662         assert(u);
1663
1664         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1665 }
1666
1667 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1668         char *t;
1669         int r;
1670
1671         assert(u);
1672         assert(type);
1673         assert(_found);
1674
1675         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1676                 return -ENOMEM;
1677
1678         assert(!unit_has_name(u, t));
1679
1680         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1681         free(t);
1682
1683         assert(r < 0 || *_found != u);
1684
1685         return r;
1686 }
1687
1688 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1689         Unit *found;
1690         char *t;
1691
1692         assert(u);
1693         assert(type);
1694         assert(_found);
1695
1696         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1697                 return -ENOMEM;
1698
1699         assert(!unit_has_name(u, t));
1700
1701         found = manager_get_unit(u->meta.manager, t);
1702         free(t);
1703
1704         if (!found)
1705                 return -ENOENT;
1706
1707         *_found = found;
1708         return 0;
1709 }
1710
1711 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1712         Unit *u = userdata;
1713         assert(u);
1714
1715         return unit_name_to_prefix_and_instance(u->meta.id);
1716 }
1717
1718 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1719         Unit *u = userdata;
1720         assert(u);
1721
1722         return unit_name_to_prefix(u->meta.id);
1723 }
1724
1725 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1726         Unit *u = userdata;
1727         char *p, *r;
1728
1729         assert(u);
1730
1731         if (!(p = unit_name_to_prefix(u->meta.id)))
1732                 return NULL;
1733
1734         r = unit_name_unescape(p);
1735         free(p);
1736
1737         return r;
1738 }
1739
1740 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1741         Unit *u = userdata;
1742         assert(u);
1743
1744         if (u->meta.instance)
1745                 return unit_name_unescape(u->meta.instance);
1746
1747         return strdup("");
1748 }
1749
1750 char *unit_name_printf(Unit *u, const char* format) {
1751
1752         /*
1753          * This will use the passed string as format string and
1754          * replace the following specifiers:
1755          *
1756          * %n: the full id of the unit                 (foo@bar.waldo)
1757          * %N: the id of the unit without the suffix   (foo@bar)
1758          * %p: the prefix                              (foo)
1759          * %i: the instance                            (bar)
1760          */
1761
1762         const Specifier table[] = {
1763                 { 'n', specifier_string,              u->meta.id },
1764                 { 'N', specifier_prefix_and_instance, NULL },
1765                 { 'p', specifier_prefix,              NULL },
1766                 { 'i', specifier_string,              u->meta.instance },
1767                 { 0, NULL, NULL }
1768         };
1769
1770         assert(u);
1771         assert(format);
1772
1773         return specifier_printf(format, table, u);
1774 }
1775
1776 char *unit_full_printf(Unit *u, const char *format) {
1777
1778         /* This is similar to unit_name_printf() but also supports
1779          * unescaping */
1780
1781         const Specifier table[] = {
1782                 { 'n', specifier_string,              u->meta.id },
1783                 { 'N', specifier_prefix_and_instance, NULL },
1784                 { 'p', specifier_prefix,              NULL },
1785                 { 'P', specifier_prefix_unescaped,    NULL },
1786                 { 'i', specifier_string,              u->meta.instance },
1787                 { 'I', specifier_instance_unescaped,  NULL },
1788                 { 0, NULL, NULL }
1789         };
1790
1791         assert(u);
1792         assert(format);
1793
1794         return specifier_printf(format, table, u);
1795 }
1796
1797 char **unit_full_printf_strv(Unit *u, char **l) {
1798         size_t n;
1799         char **r, **i, **j;
1800
1801         /* Applies unit_full_printf to every entry in l */
1802
1803         assert(u);
1804
1805         n = strv_length(l);
1806         if (!(r = new(char*, n+1)))
1807                 return NULL;
1808
1809         for (i = l, j = r; *i; i++, j++)
1810                 if (!(*j = unit_full_printf(u, *i)))
1811                         goto fail;
1812
1813         *j = NULL;
1814         return r;
1815
1816 fail:
1817         j--;
1818         while (j >= r)
1819                 free(*j);
1820
1821         free(r);
1822
1823         return NULL;
1824 }
1825
1826 int unit_watch_bus_name(Unit *u, const char *name) {
1827         assert(u);
1828         assert(name);
1829
1830         /* Watch a specific name on the bus. We only support one unit
1831          * watching each name for now. */
1832
1833         return hashmap_put(u->meta.manager->watch_bus, name, u);
1834 }
1835
1836 void unit_unwatch_bus_name(Unit *u, const char *name) {
1837         assert(u);
1838         assert(name);
1839
1840         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1841 }
1842
1843 bool unit_can_serialize(Unit *u) {
1844         assert(u);
1845
1846         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1847 }
1848
1849 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1850         int r;
1851
1852         assert(u);
1853         assert(f);
1854         assert(fds);
1855
1856         if (!unit_can_serialize(u))
1857                 return 0;
1858
1859         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1860                 return r;
1861
1862         if (u->meta.job)
1863                 unit_serialize_item(u, f, "job", job_type_to_string(u->meta.job->type));
1864
1865         /* End marker */
1866         fputc('\n', f);
1867         return 0;
1868 }
1869
1870 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1871         va_list ap;
1872
1873         assert(u);
1874         assert(f);
1875         assert(key);
1876         assert(format);
1877
1878         fputs(key, f);
1879         fputc('=', f);
1880
1881         va_start(ap, format);
1882         vfprintf(f, format, ap);
1883         va_end(ap);
1884
1885         fputc('\n', f);
1886 }
1887
1888 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1889         assert(u);
1890         assert(f);
1891         assert(key);
1892         assert(value);
1893
1894         fprintf(f, "%s=%s\n", key, value);
1895 }
1896
1897 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1898         int r;
1899
1900         assert(u);
1901         assert(f);
1902         assert(fds);
1903
1904         if (!unit_can_serialize(u))
1905                 return 0;
1906
1907         for (;;) {
1908                 char line[1024], *l, *v;
1909                 size_t k;
1910
1911                 if (!fgets(line, sizeof(line), f)) {
1912                         if (feof(f))
1913                                 return 0;
1914                         return -errno;
1915                 }
1916
1917                 l = strstrip(line);
1918
1919                 /* End marker */
1920                 if (l[0] == 0)
1921                         return 0;
1922
1923                 k = strcspn(l, "=");
1924
1925                 if (l[k] == '=') {
1926                         l[k] = 0;
1927                         v = l+k+1;
1928                 } else
1929                         v = l+k;
1930
1931                 if (streq(l, "job")) {
1932                         JobType type;
1933
1934                         if ((type = job_type_from_string(v)) < 0)
1935                                 log_debug("Failed to parse job type value %s", v);
1936                         else
1937                                 u->meta.deserialized_job = type;
1938
1939                         continue;
1940                 }
1941
1942                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1943                         return r;
1944         }
1945 }
1946
1947 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1948         Unit *device;
1949         char *e;
1950         int r;
1951
1952         assert(u);
1953
1954         if (!what)
1955                 return 0;
1956
1957         /* Adds in links to the device node that this unit is based on */
1958
1959         if (!is_device_path(what))
1960                 return 0;
1961
1962         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1963                 return -ENOMEM;
1964
1965         r = manager_load_unit(u->meta.manager, e, NULL, &device);
1966         free(e);
1967
1968         if (r < 0)
1969                 return r;
1970
1971         if ((r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_REQUIRES, device, true)) < 0)
1972                 return r;
1973
1974         if (wants)
1975                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1976                         return r;
1977
1978         return 0;
1979 }
1980
1981 int unit_coldplug(Unit *u) {
1982         int r;
1983
1984         assert(u);
1985
1986         if (UNIT_VTABLE(u)->coldplug)
1987                 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
1988                         return r;
1989
1990         if (u->meta.deserialized_job >= 0) {
1991                 if ((r = manager_add_job(u->meta.manager, u->meta.deserialized_job, u, JOB_FAIL, false, NULL)) < 0)
1992                         return r;
1993
1994                 u->meta.deserialized_job = _JOB_TYPE_INVALID;
1995         }
1996
1997         return 0;
1998 }
1999
2000 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
2001         [UNIT_SERVICE] = "service",
2002         [UNIT_TIMER] = "timer",
2003         [UNIT_SOCKET] = "socket",
2004         [UNIT_TARGET] = "target",
2005         [UNIT_DEVICE] = "device",
2006         [UNIT_MOUNT] = "mount",
2007         [UNIT_AUTOMOUNT] = "automount",
2008         [UNIT_SNAPSHOT] = "snapshot",
2009         [UNIT_SWAP] = "swap"
2010 };
2011
2012 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
2013
2014 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
2015         [UNIT_STUB] = "stub",
2016         [UNIT_LOADED] = "loaded",
2017         [UNIT_FAILED] = "failed",
2018         [UNIT_MERGED] = "merged"
2019 };
2020
2021 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
2022
2023 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
2024         [UNIT_ACTIVE] = "active",
2025         [UNIT_RELOADING] = "reloading",
2026         [UNIT_INACTIVE] = "inactive",
2027         [UNIT_MAINTENANCE] = "maintenance",
2028         [UNIT_ACTIVATING] = "activating",
2029         [UNIT_DEACTIVATING] = "deactivating"
2030 };
2031
2032 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
2033
2034 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
2035         [UNIT_REQUIRES] = "Requires",
2036         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
2037         [UNIT_WANTS] = "Wants",
2038         [UNIT_REQUISITE] = "Requisite",
2039         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
2040         [UNIT_REQUIRED_BY] = "RequiredBy",
2041         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
2042         [UNIT_WANTED_BY] = "WantedBy",
2043         [UNIT_CONFLICTS] = "Conflicts",
2044         [UNIT_BEFORE] = "Before",
2045         [UNIT_AFTER] = "After",
2046         [UNIT_REFERENCES] = "References",
2047         [UNIT_REFERENCED_BY] = "ReferencedBy"
2048 };
2049
2050 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
2051
2052 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
2053         [KILL_CONTROL_GROUP] = "control-group",
2054         [KILL_PROCESS_GROUP] = "process-group",
2055         [KILL_PROCESS] = "process",
2056         [KILL_NONE] = "none"
2057 };
2058
2059 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);