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