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
  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         [UNIT_SWAP] = &swap_vtable,
  52         [UNIT_PATH] = &path_vtable
  53 };
  54
  55 Unit *unit_new(Manager *m) {
  56         Unit *u;
  57
  58         assert(m);
  59
  60         if (!(u = new0(Unit, 1)))
  61                 return NULL;
  62
  63         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
  64                 free(u);
  65                 return NULL;
  66         }
  67
  68         u->meta.manager = m;
  69         u->meta.type = _UNIT_TYPE_INVALID;
  70         u->meta.deserialized_job = _JOB_TYPE_INVALID;
  71
  72         return u;
  73 }
  74
  75 bool unit_has_name(Unit *u, const char *name) {
  76         assert(u);
  77         assert(name);
  78
  79         return !!set_get(u->meta.names, (char*) name);
  80 }
  81
  82 int unit_add_name(Unit *u, const char *text) {
  83         UnitType t;
  84         char *s = NULL, *i = NULL;
  85         int r;
  86
  87         assert(u);
  88         assert(text);
  89
  90         if (unit_name_is_template(text)) {
  91                 if (!u->meta.instance)
  92                         return -EINVAL;
  93
  94                 s = unit_name_replace_instance(text, u->meta.instance);
  95         } else
  96                 s = strdup(text);
  97
  98         if (!s)
  99                 return -ENOMEM;
 100
 101         if (!unit_name_is_valid(s)) {
 102                 r = -EINVAL;
 103                 goto fail;
 104         }
 105
 106         assert_se((t = unit_name_to_type(s)) >= 0);
 107
 108         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
 109                 r = -EINVAL;
 110                 goto fail;
 111         }
 112
 113         if ((r = unit_name_to_instance(s, &i)) < 0)
 114                 goto fail;
 115
 116         if (i && unit_vtable[t]->no_instances)
 117                 goto fail;
 118
 119         if (u->meta.type != _UNIT_TYPE_INVALID && !streq_ptr(u->meta.instance, i)) {
 120                 r = -EINVAL;
 121                 goto fail;
 122         }
 123
 124         if (unit_vtable[t]->no_alias &&
 125             !set_isempty(u->meta.names) &&
 126             !set_get(u->meta.names, s)) {
 127                 r = -EEXIST;
 128                 goto fail;
 129         }
 130
 131         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
 132                 r = -E2BIG;
 133                 goto fail;
 134         }
 135
 136         if ((r = set_put(u->meta.names, s)) < 0) {
 137                 if (r == -EEXIST)
 138                         r = 0;
 139                 goto fail;
 140         }
 141
 142         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 143                 set_remove(u->meta.names, s);
 144                 goto fail;
 145         }
 146
 147         if (u->meta.type == _UNIT_TYPE_INVALID) {
 148
 149                 u->meta.type = t;
 150                 u->meta.id = s;
 151                 u->meta.instance = i;
 152
 153                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 154
 155                 if (UNIT_VTABLE(u)->init)
 156                         UNIT_VTABLE(u)->init(u);
 157         } else
 158                 free(i);
 159
 160         unit_add_to_dbus_queue(u);
 161         return 0;
 162
 163 fail:
 164         free(s);
 165         free(i);
 166
 167         return r;
 168 }
 169
 170 int unit_choose_id(Unit *u, const char *name) {
 171         char *s, *t = NULL;
 172
 173         assert(u);
 174         assert(name);
 175
 176         if (unit_name_is_template(name)) {
 177
 178                 if (!u->meta.instance)
 179                         return -EINVAL;
 180
 181                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
 182                         return -ENOMEM;
 183
 184                 name = t;
 185         }
 186
 187         /* Selects one of the names of this unit as the id */
 188         s = set_get(u->meta.names, (char*) name);
 189         free(t);
 190
 191         if (!s)
 192                 return -ENOENT;
 193
 194         u->meta.id = s;
 195         unit_add_to_dbus_queue(u);
 196
 197         return 0;
 198 }
 199
 200 int unit_set_description(Unit *u, const char *description) {
 201         char *s;
 202
 203         assert(u);
 204
 205         if (!(s = strdup(description)))
 206                 return -ENOMEM;
 207
 208         free(u->meta.description);
 209         u->meta.description = s;
 210
 211         unit_add_to_dbus_queue(u);
 212         return 0;
 213 }
 214
 215 bool unit_check_gc(Unit *u) {
 216         assert(u);
 217
 218         if (u->meta.load_state == UNIT_STUB)
 219                 return true;
 220
 221         if (UNIT_VTABLE(u)->no_gc)
 222                 return true;
 223
 224         if (u->meta.job)
 225                 return true;
 226
 227         if (unit_active_state(u) != UNIT_INACTIVE)
 228                 return true;
 229
 230         if (UNIT_VTABLE(u)->check_gc)
 231                 if (UNIT_VTABLE(u)->check_gc(u))
 232                         return true;
 233
 234         return false;
 235 }
 236
 237 void unit_add_to_load_queue(Unit *u) {
 238         assert(u);
 239         assert(u->meta.type != _UNIT_TYPE_INVALID);
 240
 241         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 242                 return;
 243
 244         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 245         u->meta.in_load_queue = true;
 246 }
 247
 248 void unit_add_to_cleanup_queue(Unit *u) {
 249         assert(u);
 250
 251         if (u->meta.in_cleanup_queue)
 252                 return;
 253
 254         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 255         u->meta.in_cleanup_queue = true;
 256 }
 257
 258 void unit_add_to_gc_queue(Unit *u) {
 259         assert(u);
 260
 261         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 262                 return;
 263
 264         if (unit_check_gc(u))
 265                 return;
 266
 267         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 268         u->meta.in_gc_queue = true;
 269
 270         u->meta.manager->n_in_gc_queue ++;
 271
 272         if (u->meta.manager->gc_queue_timestamp <= 0)
 273                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 274 }
 275
 276 void unit_add_to_dbus_queue(Unit *u) {
 277         assert(u);
 278         assert(u->meta.type != _UNIT_TYPE_INVALID);
 279
 280         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue)
 281                 return;
 282
 283         if (set_isempty(u->meta.manager->subscribed)) {
 284                 u->meta.sent_dbus_new_signal = true;
 285                 return;
 286         }
 287
 288         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 289         u->meta.in_dbus_queue = true;
 290 }
 291
 292 static void bidi_set_free(Unit *u, Set *s) {
 293         Iterator i;
 294         Unit *other;
 295
 296         assert(u);
 297
 298         /* Frees the set and makes sure we are dropped from the
 299          * inverse pointers */
 300
 301         SET_FOREACH(other, s, i) {
 302                 UnitDependency d;
 303
 304                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 305                         set_remove(other->meta.dependencies[d], u);
 306
 307                 unit_add_to_gc_queue(other);
 308         }
 309
 310         set_free(s);
 311 }
 312
 313 void unit_free(Unit *u) {
 314         UnitDependency d;
 315         Iterator i;
 316         char *t;
 317
 318         assert(u);
 319
 320         bus_unit_send_removed_signal(u);
 321
 322         if (u->meta.load_state != UNIT_STUB)
 323                 if (UNIT_VTABLE(u)->done)
 324                         UNIT_VTABLE(u)->done(u);
 325
 326         SET_FOREACH(t, u->meta.names, i)
 327                 hashmap_remove_value(u->meta.manager->units, t, u);
 328
 329         if (u->meta.job)
 330                 job_free(u->meta.job);
 331
 332         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 333                 bidi_set_free(u, u->meta.dependencies[d]);
 334
 335         if (u->meta.type != _UNIT_TYPE_INVALID)
 336                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 337
 338         if (u->meta.in_load_queue)
 339                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 340
 341         if (u->meta.in_dbus_queue)
 342                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 343
 344         if (u->meta.in_cleanup_queue)
 345                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 346
 347         if (u->meta.in_gc_queue) {
 348                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 349                 u->meta.manager->n_in_gc_queue--;
 350         }
 351
 352         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 353
 354         free(u->meta.description);
 355         free(u->meta.fragment_path);
 356
 357         while ((t = set_steal_first(u->meta.names)))
 358                 free(t);
 359         set_free(u->meta.names);
 360
 361         free(u->meta.instance);
 362
 363         free(u);
 364 }
 365
 366 UnitActiveState unit_active_state(Unit *u) {
 367         assert(u);
 368
 369         if (u->meta.load_state != UNIT_LOADED)
 370                 return UNIT_INACTIVE;
 371
 372         return UNIT_VTABLE(u)->active_state(u);
 373 }
 374
 375 const char* unit_sub_state_to_string(Unit *u) {
 376         assert(u);
 377
 378         return UNIT_VTABLE(u)->sub_state_to_string(u);
 379 }
 380
 381 static void complete_move(Set **s, Set **other) {
 382         assert(s);
 383         assert(other);
 384
 385         if (!*other)
 386                 return;
 387
 388         if (*s)
 389                 set_move(*s, *other);
 390         else {
 391                 *s = *other;
 392                 *other = NULL;
 393         }
 394 }
 395
 396 static void merge_names(Unit *u, Unit *other) {
 397         char *t;
 398         Iterator i;
 399
 400         assert(u);
 401         assert(other);
 402
 403         complete_move(&u->meta.names, &other->meta.names);
 404
 405         while ((t = set_steal_first(other->meta.names)))
 406                 free(t);
 407
 408         set_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_active_state(other) != UNIT_INACTIVE)
 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_SESSION)
 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 this is already (being) started, then this will
 754          * succeed. Note that this will even succeed if this unit is
 755          * not startable by the user. This is relied on to detect when
 756          * we need to wait for units and when waiting is finished. */
 757         state = unit_active_state(u);
 758         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 759                 return -EALREADY;
 760
 761         /* If it is stopped, but we cannot start it, then fail */
 762         if (!UNIT_VTABLE(u)->start)
 763                 return -EBADR;
 764
 765         /* We don't suppress calls to ->start() here when we are
 766          * already starting, to allow this request to be used as a
 767          * "hurry up" call, for example when the unit is in some "auto
 768          * restart" state where it waits for a holdoff timer to elapse
 769          * before it will start again. */
 770
 771         unit_add_to_dbus_queue(u);
 772         return UNIT_VTABLE(u)->start(u);
 773 }
 774
 775 bool unit_can_start(Unit *u) {
 776         assert(u);
 777
 778         return !!UNIT_VTABLE(u)->start;
 779 }
 780
 781 /* Errors:
 782  *         -EBADR:    This unit type does not support stopping.
 783  *         -EALREADY: Unit is already stopped.
 784  *         -EAGAIN:   An operation is already in progress. Retry later.
 785  */
 786 int unit_stop(Unit *u) {
 787         UnitActiveState state;
 788
 789         assert(u);
 790
 791         state = unit_active_state(u);
 792         if (state == UNIT_INACTIVE)
 793                 return -EALREADY;
 794
 795         if (!UNIT_VTABLE(u)->stop)
 796                 return -EBADR;
 797
 798         unit_add_to_dbus_queue(u);
 799         return UNIT_VTABLE(u)->stop(u);
 800 }
 801
 802 /* Errors:
 803  *         -EBADR:    This unit type does not support reloading.
 804  *         -ENOEXEC:  Unit is not started.
 805  *         -EAGAIN:   An operation is already in progress. Retry later.
 806  */
 807 int unit_reload(Unit *u) {
 808         UnitActiveState state;
 809
 810         assert(u);
 811
 812         if (!unit_can_reload(u))
 813                 return -EBADR;
 814
 815         state = unit_active_state(u);
 816         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 817                 return -EALREADY;
 818
 819         if (unit_active_state(u) != UNIT_ACTIVE)
 820                 return -ENOEXEC;
 821
 822         unit_add_to_dbus_queue(u);
 823         return UNIT_VTABLE(u)->reload(u);
 824 }
 825
 826 bool unit_can_reload(Unit *u) {
 827         assert(u);
 828
 829         if (!UNIT_VTABLE(u)->reload)
 830                 return false;
 831
 832         if (!UNIT_VTABLE(u)->can_reload)
 833                 return true;
 834
 835         return UNIT_VTABLE(u)->can_reload(u);
 836 }
 837
 838 static void unit_check_uneeded(Unit *u) {
 839         Iterator i;
 840         Unit *other;
 841
 842         assert(u);
 843
 844         /* If this service shall be shut down when unneeded then do
 845          * so. */
 846
 847         if (!u->meta.stop_when_unneeded)
 848                 return;
 849
 850         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 851                 return;
 852
 853         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 854                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 855                         return;
 856
 857         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 858                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 859                         return;
 860
 861         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 862                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 863                         return;
 864
 865         log_debug("Service %s is not needed anymore. Stopping.", u->meta.id);
 866
 867         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 868         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 869 }
 870
 871 static void retroactively_start_dependencies(Unit *u) {
 872         Iterator i;
 873         Unit *other;
 874
 875         assert(u);
 876         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 877
 878         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 879                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 880                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 881
 882         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 883                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 884                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 885
 886         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 887                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 888                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 889
 890         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 891                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 892                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 893
 894         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 895                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 896                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 897 }
 898
 899 static void retroactively_stop_dependencies(Unit *u) {
 900         Iterator i;
 901         Unit *other;
 902
 903         assert(u);
 904         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 905
 906         if (u->meta.recursive_stop) {
 907                 /* Pull down units need us recursively if enabled */
 908                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 909                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 910                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 911         }
 912
 913         /* Garbage collect services that might not be needed anymore, if enabled */
 914         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 915                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 916                         unit_check_uneeded(other);
 917         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 918                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 919                         unit_check_uneeded(other);
 920         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], 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_REQUISITE], 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_REQUISITE_OVERRIDABLE], i)
 927                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 928                         unit_check_uneeded(other);
 929 }
 930
 931 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 932         bool unexpected = false;
 933         timestamp ts;
 934
 935         assert(u);
 936         assert(os < _UNIT_ACTIVE_STATE_MAX);
 937         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 938
 939         /* Note that this is called for all low-level state changes,
 940          * even if they might map to the same high-level
 941          * UnitActiveState! That means that ns == os is OK an expected
 942          * behaviour here. For example: if a mount point is remounted
 943          * this function will be called too and the utmp code below
 944          * relies on that! */
 945
 946         timestamp_get(&ts);
 947
 948         if (os == UNIT_INACTIVE && ns != UNIT_INACTIVE)
 949                 u->meta.inactive_exit_timestamp = ts;
 950         else if (os != UNIT_INACTIVE && ns == UNIT_INACTIVE)
 951                 u->meta.inactive_enter_timestamp = ts;
 952
 953         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 954                 u->meta.active_enter_timestamp = ts;
 955         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 956                 u->meta.active_exit_timestamp = ts;
 957
 958         timer_unit_notify(u, ns);
 959         path_unit_notify(u, ns);
 960
 961         if (u->meta.job) {
 962
 963                 if (u->meta.job->state == JOB_WAITING)
 964
 965                         /* So we reached a different state for this
 966                          * job. Let's see if we can run it now if it
 967                          * failed previously due to EAGAIN. */
 968                         job_add_to_run_queue(u->meta.job);
 969
 970
 971                 /* Let's check whether this state change constitutes a
 972                  * finished job, or maybe cotradicts a running job and
 973                  * hence needs to invalidate jobs. */
 974
 975                 switch (u->meta.job->type) {
 976
 977                 case JOB_START:
 978                 case JOB_VERIFY_ACTIVE:
 979
 980                         if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 981                                 job_finish_and_invalidate(u->meta.job, true);
 982                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
 983                                 unexpected = true;
 984                                 job_finish_and_invalidate(u->meta.job, false);
 985                         }
 986
 987                         break;
 988
 989                 case JOB_RELOAD:
 990                 case JOB_RELOAD_OR_START:
 991
 992                         if (u->meta.job->state == JOB_RUNNING) {
 993                                 if (ns == UNIT_ACTIVE)
 994                                         job_finish_and_invalidate(u->meta.job, true);
 995                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_ACTIVE_RELOADING) {
 996                                         unexpected = true;
 997                                         job_finish_and_invalidate(u->meta.job, false);
 998                                 }
 999                         }
1000
1001                         break;
1002
1003                 case JOB_STOP:
1004                 case JOB_RESTART:
1005                 case JOB_TRY_RESTART:
1006
1007                         if (ns == UNIT_INACTIVE)
1008                                 job_finish_and_invalidate(u->meta.job, true);
1009                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
1010                                 unexpected = true;
1011                                 job_finish_and_invalidate(u->meta.job, false);
1012                         }
1013
1014                         break;
1015
1016                 default:
1017                         assert_not_reached("Job type unknown");
1018                 }
1019         }
1020
1021         /* If this state change happened without being requested by a
1022          * job, then let's retroactively start or stop dependencies */
1023
1024         if (unexpected) {
1025                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1026                         retroactively_start_dependencies(u);
1027                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1028                         retroactively_stop_dependencies(u);
1029         }
1030
1031         /* Some names are special */
1032         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1033                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1034                         /* The bus just might have become available,
1035                          * hence try to connect to it, if we aren't
1036                          * yet connected. */
1037                         bus_init_system(u->meta.manager);
1038                         bus_init_api(u->meta.manager);
1039                 }
1040
1041                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1042                         /* The syslog daemon just might have become
1043                          * available, hence try to connect to it, if
1044                          * we aren't yet connected. */
1045                         log_open();
1046
1047                 if (u->meta.type == UNIT_MOUNT)
1048                         /* Another directory became available, let's
1049                          * check if that is enough to write our utmp
1050                          * entry. */
1051                         manager_write_utmp_reboot(u->meta.manager);
1052
1053                 if (u->meta.type == UNIT_TARGET)
1054                         /* A target got activated, maybe this is a runlevel? */
1055                         manager_write_utmp_runlevel(u->meta.manager, u);
1056
1057         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1058
1059                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1060                         /* The syslog daemon might just have
1061                          * terminated, hence try to disconnect from
1062                          * it. */
1063                         log_close_syslog();
1064
1065                 /* We don't care about D-Bus here, since we'll get an
1066                  * asynchronous notification for it anyway. */
1067         }
1068
1069         /* Maybe we finished startup and are now ready for being
1070          * stopped because unneeded? */
1071         unit_check_uneeded(u);
1072
1073         unit_add_to_dbus_queue(u);
1074         unit_add_to_gc_queue(u);
1075 }
1076
1077 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1078         struct epoll_event ev;
1079
1080         assert(u);
1081         assert(fd >= 0);
1082         assert(w);
1083         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1084
1085         zero(ev);
1086         ev.data.ptr = w;
1087         ev.events = events;
1088
1089         if (epoll_ctl(u->meta.manager->epoll_fd,
1090                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1091                       fd,
1092                       &ev) < 0)
1093                 return -errno;
1094
1095         w->fd = fd;
1096         w->type = WATCH_FD;
1097         w->data.unit = u;
1098
1099         return 0;
1100 }
1101
1102 void unit_unwatch_fd(Unit *u, Watch *w) {
1103         assert(u);
1104         assert(w);
1105
1106         if (w->type == WATCH_INVALID)
1107                 return;
1108
1109         assert(w->type == WATCH_FD);
1110         assert(w->data.unit == u);
1111         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1112
1113         w->fd = -1;
1114         w->type = WATCH_INVALID;
1115         w->data.unit = NULL;
1116 }
1117
1118 int unit_watch_pid(Unit *u, pid_t pid) {
1119         assert(u);
1120         assert(pid >= 1);
1121
1122         /* Watch a specific PID. We only support one unit watching
1123          * each PID for now. */
1124
1125         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1126 }
1127
1128 void unit_unwatch_pid(Unit *u, pid_t pid) {
1129         assert(u);
1130         assert(pid >= 1);
1131
1132         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1133 }
1134
1135 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1136         struct itimerspec its;
1137         int flags, fd;
1138         bool ours;
1139
1140         assert(u);
1141         assert(w);
1142         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1143
1144         /* This will try to reuse the old timer if there is one */
1145
1146         if (w->type == WATCH_TIMER) {
1147                 ours = false;
1148                 fd = w->fd;
1149         } else {
1150                 ours = true;
1151                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1152                         return -errno;
1153         }
1154
1155         zero(its);
1156
1157         if (delay <= 0) {
1158                 /* Set absolute time in the past, but not 0, since we
1159                  * don't want to disarm the timer */
1160                 its.it_value.tv_sec = 0;
1161                 its.it_value.tv_nsec = 1;
1162
1163                 flags = TFD_TIMER_ABSTIME;
1164         } else {
1165                 timespec_store(&its.it_value, delay);
1166                 flags = 0;
1167         }
1168
1169         /* This will also flush the elapse counter */
1170         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1171                 goto fail;
1172
1173         if (w->type == WATCH_INVALID) {
1174                 struct epoll_event ev;
1175
1176                 zero(ev);
1177                 ev.data.ptr = w;
1178                 ev.events = EPOLLIN;
1179
1180                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1181                         goto fail;
1182         }
1183
1184         w->fd = fd;
1185         w->type = WATCH_TIMER;
1186         w->data.unit = u;
1187
1188         return 0;
1189
1190 fail:
1191         if (ours)
1192                 close_nointr_nofail(fd);
1193
1194         return -errno;
1195 }
1196
1197 void unit_unwatch_timer(Unit *u, Watch *w) {
1198         assert(u);
1199         assert(w);
1200
1201         if (w->type == WATCH_INVALID)
1202                 return;
1203
1204         assert(w->type == WATCH_TIMER && w->data.unit == u);
1205
1206         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1207         close_nointr_nofail(w->fd);
1208
1209         w->fd = -1;
1210         w->type = WATCH_INVALID;
1211         w->data.unit = NULL;
1212 }
1213
1214 bool unit_job_is_applicable(Unit *u, JobType j) {
1215         assert(u);
1216         assert(j >= 0 && j < _JOB_TYPE_MAX);
1217
1218         switch (j) {
1219
1220         case JOB_VERIFY_ACTIVE:
1221         case JOB_START:
1222                 return true;
1223
1224         case JOB_STOP:
1225         case JOB_RESTART:
1226         case JOB_TRY_RESTART:
1227                 return unit_can_start(u);
1228
1229         case JOB_RELOAD:
1230                 return unit_can_reload(u);
1231
1232         case JOB_RELOAD_OR_START:
1233                 return unit_can_reload(u) && unit_can_start(u);
1234
1235         default:
1236                 assert_not_reached("Invalid job type");
1237         }
1238 }
1239
1240 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1241
1242         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1243                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1244                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1245                 [UNIT_WANTS] = UNIT_WANTED_BY,
1246                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1247                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1248                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1249                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1250                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1251                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1252                 [UNIT_BEFORE] = UNIT_AFTER,
1253                 [UNIT_AFTER] = UNIT_BEFORE,
1254                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1255                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1256         };
1257         int r, q = 0, v = 0, w = 0;
1258
1259         assert(u);
1260         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1261         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1262         assert(other);
1263
1264         /* We won't allow dependencies on ourselves. We will not
1265          * consider them an error however. */
1266         if (u == other)
1267                 return 0;
1268
1269         if (UNIT_VTABLE(u)->no_requires &&
1270             (d == UNIT_REQUIRES ||
1271              d == UNIT_REQUIRES_OVERRIDABLE ||
1272              d == UNIT_REQUISITE ||
1273              d == UNIT_REQUISITE_OVERRIDABLE)) {
1274                     return -EINVAL;
1275         }
1276
1277         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1278             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1279                 return r;
1280
1281         if (add_reference)
1282                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1283                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1284                         return r;
1285
1286         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1287                 return q;
1288
1289         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1290                 r = v;
1291                 goto fail;
1292         }
1293
1294         if (add_reference) {
1295                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1296                         r = w;
1297                         goto fail;
1298                 }
1299
1300                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1301                         goto fail;
1302         }
1303
1304         unit_add_to_dbus_queue(u);
1305         return 0;
1306
1307 fail:
1308         if (q > 0)
1309                 set_remove(u->meta.dependencies[d], other);
1310
1311         if (v > 0)
1312                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1313
1314         if (w > 0)
1315                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1316
1317         return r;
1318 }
1319
1320 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1321         char *s;
1322
1323         assert(u);
1324         assert(name || path);
1325
1326         if (!name)
1327                 name = file_name_from_path(path);
1328
1329         if (!unit_name_is_template(name)) {
1330                 *p = NULL;
1331                 return name;
1332         }
1333
1334         if (u->meta.instance)
1335                 s = unit_name_replace_instance(name, u->meta.instance);
1336         else {
1337                 char *i;
1338
1339                 if (!(i = unit_name_to_prefix(u->meta.id)))
1340                         return NULL;
1341
1342                 s = unit_name_replace_instance(name, i);
1343                 free(i);
1344         }
1345
1346         if (!s)
1347                 return NULL;
1348
1349         *p = s;
1350         return s;
1351 }
1352
1353 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1354         Unit *other;
1355         int r;
1356         char *s;
1357
1358         assert(u);
1359         assert(name || path);
1360
1361         if (!(name = resolve_template(u, name, path, &s)))
1362                 return -ENOMEM;
1363
1364         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1365                 goto finish;
1366
1367         r = unit_add_dependency(u, d, other, add_reference);
1368
1369 finish:
1370         free(s);
1371         return r;
1372 }
1373
1374 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1375         Unit *other;
1376         int r;
1377         char *s;
1378
1379         assert(u);
1380         assert(name || path);
1381
1382         if (!(name = resolve_template(u, name, path, &s)))
1383                 return -ENOMEM;
1384
1385         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1386                 goto finish;
1387
1388         r = unit_add_dependency(other, d, u, add_reference);
1389
1390 finish:
1391         free(s);
1392         return r;
1393 }
1394
1395 int set_unit_path(const char *p) {
1396         char *cwd, *c;
1397         int r;
1398
1399         /* This is mostly for debug purposes */
1400
1401         if (path_is_absolute(p)) {
1402                 if (!(c = strdup(p)))
1403                         return -ENOMEM;
1404         } else {
1405                 if (!(cwd = get_current_dir_name()))
1406                         return -errno;
1407
1408                 r = asprintf(&c, "%s/%s", cwd, p);
1409                 free(cwd);
1410
1411                 if (r < 0)
1412                         return -ENOMEM;
1413         }
1414
1415         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1416                 r = -errno;
1417                 free(c);
1418                 return r;
1419         }
1420
1421         return 0;
1422 }
1423
1424 char *unit_dbus_path(Unit *u) {
1425         char *p, *e;
1426
1427         assert(u);
1428
1429         if (!(e = bus_path_escape(u->meta.id)))
1430                 return NULL;
1431
1432         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1433                 free(e);
1434                 return NULL;
1435         }
1436
1437         free(e);
1438         return p;
1439 }
1440
1441 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1442         CGroupBonding *l;
1443         int r;
1444
1445         assert(u);
1446         assert(b);
1447         assert(b->path);
1448
1449         /* Ensure this hasn't been added yet */
1450         assert(!b->unit);
1451
1452         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1453         LIST_PREPEND(CGroupBonding, by_path, l, b);
1454
1455         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1456                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1457                 return r;
1458         }
1459
1460         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1461         b->unit = u;
1462
1463         return 0;
1464 }
1465
1466 static char *default_cgroup_path(Unit *u) {
1467         char *p;
1468         int r;
1469
1470         assert(u);
1471
1472         if (u->meta.instance) {
1473                 char *t;
1474
1475                 if (!(t = unit_name_template(u->meta.id)))
1476                         return NULL;
1477
1478                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1479                 free(t);
1480         } else
1481                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1482
1483         return r < 0 ? NULL : p;
1484 }
1485
1486 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1487         size_t n;
1488         char *controller = NULL, *path = NULL;
1489         CGroupBonding *b = NULL;
1490         int r;
1491
1492         assert(u);
1493         assert(name);
1494
1495         /* Detect controller name */
1496         n = strcspn(name, ":");
1497
1498         if (name[n] == 0 ||
1499             (name[n] == ':' && name[n+1] == 0)) {
1500
1501                 /* Only controller name, no path? */
1502
1503                 if (!(path = default_cgroup_path(u)))
1504                         return -ENOMEM;
1505
1506         } else {
1507                 const char *p;
1508
1509                 /* Controller name, and path. */
1510                 p = name+n+1;
1511
1512                 if (!path_is_absolute(p))
1513                         return -EINVAL;
1514
1515                 if (!(path = strdup(p)))
1516                         return -ENOMEM;
1517         }
1518
1519         if (n > 0)
1520                 controller = strndup(name, n);
1521         else
1522                 controller = strdup(u->meta.manager->cgroup_controller);
1523
1524         if (!controller) {
1525                 r = -ENOMEM;
1526                 goto fail;
1527         }
1528
1529         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1530                 r = -EEXIST;
1531                 goto fail;
1532         }
1533
1534         if (!(b = new0(CGroupBonding, 1))) {
1535                 r = -ENOMEM;
1536                 goto fail;
1537         }
1538
1539         b->controller = controller;
1540         b->path = path;
1541         b->only_us = false;
1542         b->clean_up = false;
1543
1544         if ((r = unit_add_cgroup(u, b)) < 0)
1545                 goto fail;
1546
1547         return 0;
1548
1549 fail:
1550         free(path);
1551         free(controller);
1552         free(b);
1553
1554         return r;
1555 }
1556
1557 int unit_add_default_cgroup(Unit *u) {
1558         CGroupBonding *b;
1559         int r = -ENOMEM;
1560
1561         assert(u);
1562
1563         /* Adds in the default cgroup data, if it wasn't specified yet */
1564
1565         if (unit_get_default_cgroup(u))
1566                 return 0;
1567
1568         if (!(b = new0(CGroupBonding, 1)))
1569                 return -ENOMEM;
1570
1571         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1572                 goto fail;
1573
1574         if (!(b->path = default_cgroup_path(u)))
1575                 goto fail;
1576
1577         b->clean_up = true;
1578         b->only_us = true;
1579
1580         if ((r = unit_add_cgroup(u, b)) < 0)
1581                 goto fail;
1582
1583         return 0;
1584
1585 fail:
1586         free(b->path);
1587         free(b->controller);
1588         free(b);
1589
1590         return r;
1591 }
1592
1593 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1594         assert(u);
1595
1596         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1597 }
1598
1599 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1600         char *t;
1601         int r;
1602
1603         assert(u);
1604         assert(type);
1605         assert(_found);
1606
1607         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1608                 return -ENOMEM;
1609
1610         assert(!unit_has_name(u, t));
1611
1612         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1613         free(t);
1614
1615         assert(r < 0 || *_found != u);
1616
1617         return r;
1618 }
1619
1620 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1621         Unit *found;
1622         char *t;
1623
1624         assert(u);
1625         assert(type);
1626         assert(_found);
1627
1628         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1629                 return -ENOMEM;
1630
1631         assert(!unit_has_name(u, t));
1632
1633         found = manager_get_unit(u->meta.manager, t);
1634         free(t);
1635
1636         if (!found)
1637                 return -ENOENT;
1638
1639         *_found = found;
1640         return 0;
1641 }
1642
1643 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1644         Unit *u = userdata;
1645         assert(u);
1646
1647         return unit_name_to_prefix_and_instance(u->meta.id);
1648 }
1649
1650 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1651         Unit *u = userdata;
1652         assert(u);
1653
1654         return unit_name_to_prefix(u->meta.id);
1655 }
1656
1657 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1658         Unit *u = userdata;
1659         char *p, *r;
1660
1661         assert(u);
1662
1663         if (!(p = unit_name_to_prefix(u->meta.id)))
1664                 return NULL;
1665
1666         r = unit_name_unescape(p);
1667         free(p);
1668
1669         return r;
1670 }
1671
1672 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1673         Unit *u = userdata;
1674         assert(u);
1675
1676         if (u->meta.instance)
1677                 return unit_name_unescape(u->meta.instance);
1678
1679         return strdup("");
1680 }
1681
1682 char *unit_name_printf(Unit *u, const char* format) {
1683
1684         /*
1685          * This will use the passed string as format string and
1686          * replace the following specifiers:
1687          *
1688          * %n: the full id of the unit                 (foo@bar.waldo)
1689          * %N: the id of the unit without the suffix   (foo@bar)
1690          * %p: the prefix                              (foo)
1691          * %i: the instance                            (bar)
1692          */
1693
1694         const Specifier table[] = {
1695                 { 'n', specifier_string,              u->meta.id },
1696                 { 'N', specifier_prefix_and_instance, NULL },
1697                 { 'p', specifier_prefix,              NULL },
1698                 { 'i', specifier_string,              u->meta.instance },
1699                 { 0, NULL, NULL }
1700         };
1701
1702         assert(u);
1703         assert(format);
1704
1705         return specifier_printf(format, table, u);
1706 }
1707
1708 char *unit_full_printf(Unit *u, const char *format) {
1709
1710         /* This is similar to unit_name_printf() but also supports
1711          * unescaping */
1712
1713         const Specifier table[] = {
1714                 { 'n', specifier_string,              u->meta.id },
1715                 { 'N', specifier_prefix_and_instance, NULL },
1716                 { 'p', specifier_prefix,              NULL },
1717                 { 'P', specifier_prefix_unescaped,    NULL },
1718                 { 'i', specifier_string,              u->meta.instance },
1719                 { 'I', specifier_instance_unescaped,  NULL },
1720                 { 0, NULL, NULL }
1721         };
1722
1723         assert(u);
1724         assert(format);
1725
1726         return specifier_printf(format, table, u);
1727 }
1728
1729 char **unit_full_printf_strv(Unit *u, char **l) {
1730         size_t n;
1731         char **r, **i, **j;
1732
1733         /* Applies unit_full_printf to every entry in l */
1734
1735         assert(u);
1736
1737         n = strv_length(l);
1738         if (!(r = new(char*, n+1)))
1739                 return NULL;
1740
1741         for (i = l, j = r; *i; i++, j++)
1742                 if (!(*j = unit_full_printf(u, *i)))
1743                         goto fail;
1744
1745         *j = NULL;
1746         return r;
1747
1748 fail:
1749         j--;
1750         while (j >= r)
1751                 free(*j);
1752
1753         free(r);
1754
1755         return NULL;
1756 }
1757
1758 int unit_watch_bus_name(Unit *u, const char *name) {
1759         assert(u);
1760         assert(name);
1761
1762         /* Watch a specific name on the bus. We only support one unit
1763          * watching each name for now. */
1764
1765         return hashmap_put(u->meta.manager->watch_bus, name, u);
1766 }
1767
1768 void unit_unwatch_bus_name(Unit *u, const char *name) {
1769         assert(u);
1770         assert(name);
1771
1772         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1773 }
1774
1775 bool unit_can_serialize(Unit *u) {
1776         assert(u);
1777
1778         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1779 }
1780
1781 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1782         int r;
1783
1784         assert(u);
1785         assert(f);
1786         assert(fds);
1787
1788         if (!unit_can_serialize(u))
1789                 return 0;
1790
1791         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1792                 return r;
1793
1794         if (u->meta.job)
1795                 unit_serialize_item(u, f, "job", job_type_to_string(u->meta.job->type));
1796
1797         /* End marker */
1798         fputc('\n', f);
1799         return 0;
1800 }
1801
1802 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1803         va_list ap;
1804
1805         assert(u);
1806         assert(f);
1807         assert(key);
1808         assert(format);
1809
1810         fputs(key, f);
1811         fputc('=', f);
1812
1813         va_start(ap, format);
1814         vfprintf(f, format, ap);
1815         va_end(ap);
1816
1817         fputc('\n', f);
1818 }
1819
1820 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1821         assert(u);
1822         assert(f);
1823         assert(key);
1824         assert(value);
1825
1826         fprintf(f, "%s=%s\n", key, value);
1827 }
1828
1829 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1830         int r;
1831
1832         assert(u);
1833         assert(f);
1834         assert(fds);
1835
1836         if (!unit_can_serialize(u))
1837                 return 0;
1838
1839         for (;;) {
1840                 char line[1024], *l, *v;
1841                 size_t k;
1842
1843                 if (!fgets(line, sizeof(line), f)) {
1844                         if (feof(f))
1845                                 return 0;
1846                         return -errno;
1847                 }
1848
1849                 l = strstrip(line);
1850
1851                 /* End marker */
1852                 if (l[0] == 0)
1853                         return 0;
1854
1855                 k = strcspn(l, "=");
1856
1857                 if (l[k] == '=') {
1858                         l[k] = 0;
1859                         v = l+k+1;
1860                 } else
1861                         v = l+k;
1862
1863                 if (streq(l, "job")) {
1864                         JobType type;
1865
1866                         if ((type = job_type_from_string(v)) < 0)
1867                                 log_debug("Failed to parse job type value %s", v);
1868                         else
1869                                 u->meta.deserialized_job = type;
1870
1871                         continue;
1872                 }
1873
1874                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1875                         return r;
1876         }
1877 }
1878
1879 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1880         Unit *device;
1881         char *e;
1882         int r;
1883
1884         assert(u);
1885
1886         if (!what)
1887                 return 0;
1888
1889         /* Adds in links to the device node that this unit is based on */
1890
1891         if (!is_device_path(what))
1892                 return 0;
1893
1894         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1895                 return -ENOMEM;
1896
1897         r = manager_load_unit(u->meta.manager, e, NULL, &device);
1898         free(e);
1899
1900         if (r < 0)
1901                 return r;
1902
1903         if ((r = unit_add_dependency(u, UNIT_AFTER, device, true)) < 0)
1904                 return r;
1905
1906         if ((r = unit_add_dependency(u, UNIT_REQUIRES, device, true)) < 0)
1907                 return r;
1908
1909         if (wants)
1910                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1911                         return r;
1912
1913         return 0;
1914 }
1915
1916 int unit_coldplug(Unit *u) {
1917         int r;
1918
1919         assert(u);
1920
1921         if (UNIT_VTABLE(u)->coldplug)
1922                 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
1923                         return r;
1924
1925         if (u->meta.deserialized_job >= 0) {
1926                 if ((r = manager_add_job(u->meta.manager, u->meta.deserialized_job, u, JOB_FAIL, false, NULL)) < 0)
1927                         return r;
1928
1929                 u->meta.deserialized_job = _JOB_TYPE_INVALID;
1930         }
1931
1932         return 0;
1933 }
1934
1935 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1936         [UNIT_SERVICE] = "service",
1937         [UNIT_TIMER] = "timer",
1938         [UNIT_SOCKET] = "socket",
1939         [UNIT_TARGET] = "target",
1940         [UNIT_DEVICE] = "device",
1941         [UNIT_MOUNT] = "mount",
1942         [UNIT_AUTOMOUNT] = "automount",
1943         [UNIT_SNAPSHOT] = "snapshot",
1944         [UNIT_SWAP] = "swap"
1945 };
1946
1947 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1948
1949 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1950         [UNIT_STUB] = "stub",
1951         [UNIT_LOADED] = "loaded",
1952         [UNIT_FAILED] = "failed",
1953         [UNIT_MERGED] = "merged"
1954 };
1955
1956 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1957
1958 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1959         [UNIT_ACTIVE] = "active",
1960         [UNIT_INACTIVE] = "inactive",
1961         [UNIT_ACTIVATING] = "activating",
1962         [UNIT_DEACTIVATING] = "deactivating"
1963 };
1964
1965 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1966
1967 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1968         [UNIT_REQUIRES] = "Requires",
1969         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
1970         [UNIT_WANTS] = "Wants",
1971         [UNIT_REQUISITE] = "Requisite",
1972         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
1973         [UNIT_REQUIRED_BY] = "RequiredBy",
1974         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
1975         [UNIT_WANTED_BY] = "WantedBy",
1976         [UNIT_CONFLICTS] = "Conflicts",
1977         [UNIT_BEFORE] = "Before",
1978         [UNIT_AFTER] = "After",
1979         [UNIT_REFERENCES] = "References",
1980         [UNIT_REFERENCED_BY] = "ReferencedBy"
1981 };
1982
1983 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
1984
1985 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1986         [KILL_CONTROL_GROUP] = "control-group",
1987         [KILL_PROCESS_GROUP] = "process-group",
1988         [KILL_PROCESS] = "process",
1989         [KILL_NONE] = "none"
1990 };
1991
1992 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);