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