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 };
  53
  54 Unit *unit_new(Manager *m) {
  55         Unit *u;
  56
  57         assert(m);
  58
  59         if (!(u = new0(Unit, 1)))
  60                 return NULL;
  61
  62         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
  63                 free(u);
  64                 return NULL;
  65         }
  66
  67         u->meta.manager = m;
  68         u->meta.type = _UNIT_TYPE_INVALID;
  69
  70         return u;
  71 }
  72
  73 bool unit_has_name(Unit *u, const char *name) {
  74         assert(u);
  75         assert(name);
  76
  77         return !!set_get(u->meta.names, (char*) name);
  78 }
  79
  80 int unit_add_name(Unit *u, const char *text) {
  81         UnitType t;
  82         char *s = NULL, *i = NULL;
  83         int r;
  84
  85         assert(u);
  86         assert(text);
  87
  88         if (unit_name_is_template(text)) {
  89                 if (!u->meta.instance)
  90                         return -EINVAL;
  91
  92                 s = unit_name_replace_instance(text, u->meta.instance);
  93         } else
  94                 s = strdup(text);
  95
  96         if (!s)
  97                 return -ENOMEM;
  98
  99         if (!unit_name_is_valid(s)) {
 100                 r = -EINVAL;
 101                 goto fail;
 102         }
 103
 104         assert_se((t = unit_name_to_type(s)) >= 0);
 105
 106         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
 107                 r = -EINVAL;
 108                 goto fail;
 109         }
 110
 111         if ((r = unit_name_to_instance(s, &i)) < 0)
 112                 goto fail;
 113
 114         if (i && unit_vtable[t]->no_instances)
 115                 goto fail;
 116
 117         if (u->meta.type != _UNIT_TYPE_INVALID && !streq_ptr(u->meta.instance, i)) {
 118                 r = -EINVAL;
 119                 goto fail;
 120         }
 121
 122         if (unit_vtable[t]->no_alias &&
 123             !set_isempty(u->meta.names) &&
 124             !set_get(u->meta.names, s)) {
 125                 r = -EEXIST;
 126                 goto fail;
 127         }
 128
 129         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
 130                 r = -E2BIG;
 131                 goto fail;
 132         }
 133
 134         if ((r = set_put(u->meta.names, s)) < 0) {
 135                 if (r == -EEXIST)
 136                         r = 0;
 137                 goto fail;
 138         }
 139
 140         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 141                 set_remove(u->meta.names, s);
 142                 goto fail;
 143         }
 144
 145         if (u->meta.type == _UNIT_TYPE_INVALID) {
 146
 147                 u->meta.type = t;
 148                 u->meta.id = s;
 149                 u->meta.instance = i;
 150
 151                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 152
 153                 if (UNIT_VTABLE(u)->init)
 154                         UNIT_VTABLE(u)->init(u);
 155         } else
 156                 free(i);
 157
 158         unit_add_to_dbus_queue(u);
 159         return 0;
 160
 161 fail:
 162         free(s);
 163         free(i);
 164
 165         return r;
 166 }
 167
 168 int unit_choose_id(Unit *u, const char *name) {
 169         char *s, *t = NULL;
 170
 171         assert(u);
 172         assert(name);
 173
 174         if (unit_name_is_template(name)) {
 175
 176                 if (!u->meta.instance)
 177                         return -EINVAL;
 178
 179                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
 180                         return -ENOMEM;
 181
 182                 name = t;
 183         }
 184
 185         /* Selects one of the names of this unit as the id */
 186         s = set_get(u->meta.names, (char*) name);
 187         free(t);
 188
 189         if (!s)
 190                 return -ENOENT;
 191
 192         u->meta.id = s;
 193         unit_add_to_dbus_queue(u);
 194
 195         return 0;
 196 }
 197
 198 int unit_set_description(Unit *u, const char *description) {
 199         char *s;
 200
 201         assert(u);
 202
 203         if (!(s = strdup(description)))
 204                 return -ENOMEM;
 205
 206         free(u->meta.description);
 207         u->meta.description = s;
 208
 209         unit_add_to_dbus_queue(u);
 210         return 0;
 211 }
 212
 213 bool unit_check_gc(Unit *u) {
 214         assert(u);
 215
 216         if (u->meta.load_state == UNIT_STUB)
 217                 return true;
 218
 219         if (UNIT_VTABLE(u)->no_gc)
 220                 return true;
 221
 222         if (u->meta.job)
 223                 return true;
 224
 225         if (unit_active_state(u) != UNIT_INACTIVE)
 226                 return true;
 227
 228         if (UNIT_VTABLE(u)->check_gc)
 229                 if (UNIT_VTABLE(u)->check_gc(u))
 230                         return true;
 231
 232         return false;
 233 }
 234
 235 void unit_add_to_load_queue(Unit *u) {
 236         assert(u);
 237         assert(u->meta.type != _UNIT_TYPE_INVALID);
 238
 239         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 240                 return;
 241
 242         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 243         u->meta.in_load_queue = true;
 244 }
 245
 246 void unit_add_to_cleanup_queue(Unit *u) {
 247         assert(u);
 248
 249         if (u->meta.in_cleanup_queue)
 250                 return;
 251
 252         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 253         u->meta.in_cleanup_queue = true;
 254 }
 255
 256 void unit_add_to_gc_queue(Unit *u) {
 257         assert(u);
 258
 259         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 260                 return;
 261
 262         if (unit_check_gc(u))
 263                 return;
 264
 265         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 266         u->meta.in_gc_queue = true;
 267
 268         u->meta.manager->n_in_gc_queue ++;
 269
 270         if (u->meta.manager->gc_queue_timestamp <= 0)
 271                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 272 }
 273
 274 void unit_add_to_dbus_queue(Unit *u) {
 275         assert(u);
 276         assert(u->meta.type != _UNIT_TYPE_INVALID);
 277
 278         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue)
 279                 return;
 280
 281         if (set_isempty(u->meta.manager->subscribed)) {
 282                 u->meta.sent_dbus_new_signal = true;
 283                 return;
 284         }
 285
 286         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 287         u->meta.in_dbus_queue = true;
 288 }
 289
 290 static void bidi_set_free(Unit *u, Set *s) {
 291         Iterator i;
 292         Unit *other;
 293
 294         assert(u);
 295
 296         /* Frees the set and makes sure we are dropped from the
 297          * inverse pointers */
 298
 299         SET_FOREACH(other, s, i) {
 300                 UnitDependency d;
 301
 302                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 303                         set_remove(other->meta.dependencies[d], u);
 304
 305                 unit_add_to_gc_queue(other);
 306         }
 307
 308         set_free(s);
 309 }
 310
 311 void unit_free(Unit *u) {
 312         UnitDependency d;
 313         Iterator i;
 314         char *t;
 315
 316         assert(u);
 317
 318         bus_unit_send_removed_signal(u);
 319
 320         /* Detach from next 'bigger' objects */
 321         SET_FOREACH(t, u->meta.names, i)
 322                 hashmap_remove_value(u->meta.manager->units, t, u);
 323
 324         if (u->meta.type != _UNIT_TYPE_INVALID)
 325                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 326
 327         if (u->meta.in_load_queue)
 328                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 329
 330         if (u->meta.in_dbus_queue)
 331                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 332
 333         if (u->meta.in_cleanup_queue)
 334                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 335
 336         if (u->meta.in_gc_queue) {
 337                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 338                 u->meta.manager->n_in_gc_queue--;
 339         }
 340
 341         /* Free data and next 'smaller' objects */
 342         if (u->meta.job)
 343                 job_free(u->meta.job);
 344
 345         if (u->meta.load_state != UNIT_STUB)
 346                 if (UNIT_VTABLE(u)->done)
 347                         UNIT_VTABLE(u)->done(u);
 348
 349         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 350
 351         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 352                 bidi_set_free(u, u->meta.dependencies[d]);
 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)),
 604                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_enter_timestamp)),
 605                 prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->meta.active_exit_timestamp)),
 606                 prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->meta.inactive_enter_timestamp)),
 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         usec_t 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         ts = now(CLOCK_REALTIME);
 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         if (u->meta.job) {
 959
 960                 if (u->meta.job->state == JOB_WAITING)
 961
 962                         /* So we reached a different state for this
 963                          * job. Let's see if we can run it now if it
 964                          * failed previously due to EAGAIN. */
 965                         job_add_to_run_queue(u->meta.job);
 966
 967                 else {
 968                         assert(u->meta.job->state == JOB_RUNNING);
 969
 970                         /* Let's check whether this state change
 971                          * constitutes a finished job, or maybe
 972                          * cotradicts a running job and hence needs to
 973                          * 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 (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 (ns == UNIT_ACTIVE)
 993                                         job_finish_and_invalidate(u->meta.job, true);
 994                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_ACTIVE_RELOADING) {
 995                                         unexpected = true;
 996                                         job_finish_and_invalidate(u->meta.job, false);
 997                                 }
 998
 999                                 break;
1000
1001                         case JOB_STOP:
1002                         case JOB_RESTART:
1003                         case JOB_TRY_RESTART:
1004
1005                                 if (ns == UNIT_INACTIVE)
1006                                         job_finish_and_invalidate(u->meta.job, true);
1007                                 else if (ns != UNIT_DEACTIVATING) {
1008                                         unexpected = true;
1009                                         job_finish_and_invalidate(u->meta.job, false);
1010                                 }
1011
1012                                 break;
1013
1014                         default:
1015                                 assert_not_reached("Job type unknown");
1016                         }
1017                 }
1018         }
1019
1020         /* If this state change happened without being requested by a
1021          * job, then let's retroactively start or stop dependencies */
1022
1023         if (unexpected) {
1024                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1025                         retroactively_start_dependencies(u);
1026                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1027                         retroactively_stop_dependencies(u);
1028         }
1029
1030         /* Some names are special */
1031         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1032                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1033                         /* The bus just might have become available,
1034                          * hence try to connect to it, if we aren't
1035                          * yet connected. */
1036                         bus_init_system(u->meta.manager);
1037                         bus_init_api(u->meta.manager);
1038                 }
1039
1040                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1041                         /* The syslog daemon just might have become
1042                          * available, hence try to connect to it, if
1043                          * we aren't yet connected. */
1044                         log_open();
1045
1046                 if (u->meta.type == UNIT_MOUNT)
1047                         /* Another directory became available, let's
1048                          * check if that is enough to write our utmp
1049                          * entry. */
1050                         manager_write_utmp_reboot(u->meta.manager);
1051
1052                 if (u->meta.type == UNIT_TARGET)
1053                         /* A target got activated, maybe this is a runlevel? */
1054                         manager_write_utmp_runlevel(u->meta.manager, u);
1055
1056         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1057
1058                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1059                         /* The syslog daemon might just have
1060                          * terminated, hence try to disconnect from
1061                          * it. */
1062                         log_close_syslog();
1063
1064                 /* We don't care about D-Bus here, since we'll get an
1065                  * asynchronous notification for it anyway. */
1066         }
1067
1068         /* Maybe we finished startup and are now ready for being
1069          * stopped because unneeded? */
1070         unit_check_uneeded(u);
1071
1072         unit_add_to_dbus_queue(u);
1073         unit_add_to_gc_queue(u);
1074 }
1075
1076 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1077         struct epoll_event ev;
1078
1079         assert(u);
1080         assert(fd >= 0);
1081         assert(w);
1082         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1083
1084         zero(ev);
1085         ev.data.ptr = w;
1086         ev.events = events;
1087
1088         if (epoll_ctl(u->meta.manager->epoll_fd,
1089                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1090                       fd,
1091                       &ev) < 0)
1092                 return -errno;
1093
1094         w->fd = fd;
1095         w->type = WATCH_FD;
1096         w->data.unit = u;
1097
1098         return 0;
1099 }
1100
1101 void unit_unwatch_fd(Unit *u, Watch *w) {
1102         assert(u);
1103         assert(w);
1104
1105         if (w->type == WATCH_INVALID)
1106                 return;
1107
1108         assert(w->type == WATCH_FD);
1109         assert(w->data.unit == u);
1110         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1111
1112         w->fd = -1;
1113         w->type = WATCH_INVALID;
1114         w->data.unit = NULL;
1115 }
1116
1117 int unit_watch_pid(Unit *u, pid_t pid) {
1118         assert(u);
1119         assert(pid >= 1);
1120
1121         /* Watch a specific PID. We only support one unit watching
1122          * each PID for now. */
1123
1124         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1125 }
1126
1127 void unit_unwatch_pid(Unit *u, pid_t pid) {
1128         assert(u);
1129         assert(pid >= 1);
1130
1131         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1132 }
1133
1134 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1135         struct itimerspec its;
1136         int flags, fd;
1137         bool ours;
1138
1139         assert(u);
1140         assert(w);
1141         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1142
1143         /* This will try to reuse the old timer if there is one */
1144
1145         if (w->type == WATCH_TIMER) {
1146                 ours = false;
1147                 fd = w->fd;
1148         } else {
1149                 ours = true;
1150                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1151                         return -errno;
1152         }
1153
1154         zero(its);
1155
1156         if (delay <= 0) {
1157                 /* Set absolute time in the past, but not 0, since we
1158                  * don't want to disarm the timer */
1159                 its.it_value.tv_sec = 0;
1160                 its.it_value.tv_nsec = 1;
1161
1162                 flags = TFD_TIMER_ABSTIME;
1163         } else {
1164                 timespec_store(&its.it_value, delay);
1165                 flags = 0;
1166         }
1167
1168         /* This will also flush the elapse counter */
1169         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1170                 goto fail;
1171
1172         if (w->type == WATCH_INVALID) {
1173                 struct epoll_event ev;
1174
1175                 zero(ev);
1176                 ev.data.ptr = w;
1177                 ev.events = EPOLLIN;
1178
1179                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1180                         goto fail;
1181         }
1182
1183         w->fd = fd;
1184         w->type = WATCH_TIMER;
1185         w->data.unit = u;
1186
1187         return 0;
1188
1189 fail:
1190         if (ours)
1191                 close_nointr_nofail(fd);
1192
1193         return -errno;
1194 }
1195
1196 void unit_unwatch_timer(Unit *u, Watch *w) {
1197         assert(u);
1198         assert(w);
1199
1200         if (w->type == WATCH_INVALID)
1201                 return;
1202
1203         assert(w->type == WATCH_TIMER && w->data.unit == u);
1204
1205         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1206         close_nointr_nofail(w->fd);
1207
1208         w->fd = -1;
1209         w->type = WATCH_INVALID;
1210         w->data.unit = NULL;
1211 }
1212
1213 bool unit_job_is_applicable(Unit *u, JobType j) {
1214         assert(u);
1215         assert(j >= 0 && j < _JOB_TYPE_MAX);
1216
1217         switch (j) {
1218
1219         case JOB_VERIFY_ACTIVE:
1220         case JOB_START:
1221                 return true;
1222
1223         case JOB_STOP:
1224         case JOB_RESTART:
1225         case JOB_TRY_RESTART:
1226                 return unit_can_start(u);
1227
1228         case JOB_RELOAD:
1229                 return unit_can_reload(u);
1230
1231         case JOB_RELOAD_OR_START:
1232                 return unit_can_reload(u) && unit_can_start(u);
1233
1234         default:
1235                 assert_not_reached("Invalid job type");
1236         }
1237 }
1238
1239 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1240
1241         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1242                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1243                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1244                 [UNIT_WANTS] = UNIT_WANTED_BY,
1245                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1246                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1247                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1248                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1249                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1250                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1251                 [UNIT_BEFORE] = UNIT_AFTER,
1252                 [UNIT_AFTER] = UNIT_BEFORE,
1253                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1254                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1255         };
1256         int r, q = 0, v = 0, w = 0;
1257
1258         assert(u);
1259         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1260         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1261         assert(other);
1262
1263         /* We won't allow dependencies on ourselves. We will not
1264          * consider them an error however. */
1265         if (u == other)
1266                 return 0;
1267
1268         if (UNIT_VTABLE(u)->no_requires &&
1269             (d == UNIT_REQUIRES ||
1270              d == UNIT_REQUIRES_OVERRIDABLE ||
1271              d == UNIT_REQUISITE ||
1272              d == UNIT_REQUISITE_OVERRIDABLE)) {
1273                     return -EINVAL;
1274         }
1275
1276         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1277             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1278                 return r;
1279
1280         if (add_reference)
1281                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1282                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1283                         return r;
1284
1285         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1286                 return q;
1287
1288         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1289                 r = v;
1290                 goto fail;
1291         }
1292
1293         if (add_reference) {
1294                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1295                         r = w;
1296                         goto fail;
1297                 }
1298
1299                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1300                         goto fail;
1301         }
1302
1303         unit_add_to_dbus_queue(u);
1304         return 0;
1305
1306 fail:
1307         if (q > 0)
1308                 set_remove(u->meta.dependencies[d], other);
1309
1310         if (v > 0)
1311                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1312
1313         if (w > 0)
1314                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1315
1316         return r;
1317 }
1318
1319 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1320         char *s;
1321
1322         assert(u);
1323         assert(name || path);
1324
1325         if (!name)
1326                 name = file_name_from_path(path);
1327
1328         if (!unit_name_is_template(name)) {
1329                 *p = NULL;
1330                 return name;
1331         }
1332
1333         if (u->meta.instance)
1334                 s = unit_name_replace_instance(name, u->meta.instance);
1335         else {
1336                 char *i;
1337
1338                 if (!(i = unit_name_to_prefix(u->meta.id)))
1339                         return NULL;
1340
1341                 s = unit_name_replace_instance(name, i);
1342                 free(i);
1343         }
1344
1345         if (!s)
1346                 return NULL;
1347
1348         *p = s;
1349         return s;
1350 }
1351
1352 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1353         Unit *other;
1354         int r;
1355         char *s;
1356
1357         assert(u);
1358         assert(name || path);
1359
1360         if (!(name = resolve_template(u, name, path, &s)))
1361                 return -ENOMEM;
1362
1363         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1364                 goto finish;
1365
1366         r = unit_add_dependency(u, d, other, add_reference);
1367
1368 finish:
1369         free(s);
1370         return r;
1371 }
1372
1373 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1374         Unit *other;
1375         int r;
1376         char *s;
1377
1378         assert(u);
1379         assert(name || path);
1380
1381         if (!(name = resolve_template(u, name, path, &s)))
1382                 return -ENOMEM;
1383
1384         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1385                 goto finish;
1386
1387         r = unit_add_dependency(other, d, u, add_reference);
1388
1389 finish:
1390         free(s);
1391         return r;
1392 }
1393
1394 int set_unit_path(const char *p) {
1395         char *cwd, *c;
1396         int r;
1397
1398         /* This is mostly for debug purposes */
1399
1400         if (path_is_absolute(p)) {
1401                 if (!(c = strdup(p)))
1402                         return -ENOMEM;
1403         } else {
1404                 if (!(cwd = get_current_dir_name()))
1405                         return -errno;
1406
1407                 r = asprintf(&c, "%s/%s", cwd, p);
1408                 free(cwd);
1409
1410                 if (r < 0)
1411                         return -ENOMEM;
1412         }
1413
1414         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1415                 r = -errno;
1416                 free(c);
1417                 return r;
1418         }
1419
1420         return 0;
1421 }
1422
1423 char *unit_dbus_path(Unit *u) {
1424         char *p, *e;
1425
1426         assert(u);
1427
1428         if (!(e = bus_path_escape(u->meta.id)))
1429                 return NULL;
1430
1431         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1432                 free(e);
1433                 return NULL;
1434         }
1435
1436         free(e);
1437         return p;
1438 }
1439
1440 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1441         CGroupBonding *l;
1442         int r;
1443
1444         assert(u);
1445         assert(b);
1446         assert(b->path);
1447
1448         /* Ensure this hasn't been added yet */
1449         assert(!b->unit);
1450
1451         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1452         LIST_PREPEND(CGroupBonding, by_path, l, b);
1453
1454         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1455                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1456                 return r;
1457         }
1458
1459         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1460         b->unit = u;
1461
1462         return 0;
1463 }
1464
1465 static char *default_cgroup_path(Unit *u) {
1466         char *p;
1467         int r;
1468
1469         assert(u);
1470
1471         if (u->meta.instance) {
1472                 char *t;
1473
1474                 if (!(t = unit_name_template(u->meta.id)))
1475                         return NULL;
1476
1477                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1478                 free(t);
1479         } else
1480                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1481
1482         return r < 0 ? NULL : p;
1483 }
1484
1485 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1486         size_t n;
1487         char *controller = NULL, *path = NULL;
1488         CGroupBonding *b = NULL;
1489         int r;
1490
1491         assert(u);
1492         assert(name);
1493
1494         /* Detect controller name */
1495         n = strcspn(name, ":");
1496
1497         if (name[n] == 0 ||
1498             (name[n] == ':' && name[n+1] == 0)) {
1499
1500                 /* Only controller name, no path? */
1501
1502                 if (!(path = default_cgroup_path(u)))
1503                         return -ENOMEM;
1504
1505         } else {
1506                 const char *p;
1507
1508                 /* Controller name, and path. */
1509                 p = name+n+1;
1510
1511                 if (!path_is_absolute(p))
1512                         return -EINVAL;
1513
1514                 if (!(path = strdup(p)))
1515                         return -ENOMEM;
1516         }
1517
1518         if (n > 0)
1519                 controller = strndup(name, n);
1520         else
1521                 controller = strdup(u->meta.manager->cgroup_controller);
1522
1523         if (!controller) {
1524                 r = -ENOMEM;
1525                 goto fail;
1526         }
1527
1528         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1529                 r = -EEXIST;
1530                 goto fail;
1531         }
1532
1533         if (!(b = new0(CGroupBonding, 1))) {
1534                 r = -ENOMEM;
1535                 goto fail;
1536         }
1537
1538         b->controller = controller;
1539         b->path = path;
1540         b->only_us = false;
1541         b->clean_up = false;
1542
1543         if ((r = unit_add_cgroup(u, b)) < 0)
1544                 goto fail;
1545
1546         return 0;
1547
1548 fail:
1549         free(path);
1550         free(controller);
1551         free(b);
1552
1553         return r;
1554 }
1555
1556 int unit_add_default_cgroup(Unit *u) {
1557         CGroupBonding *b;
1558         int r = -ENOMEM;
1559
1560         assert(u);
1561
1562         /* Adds in the default cgroup data, if it wasn't specified yet */
1563
1564         if (unit_get_default_cgroup(u))
1565                 return 0;
1566
1567         if (!(b = new0(CGroupBonding, 1)))
1568                 return -ENOMEM;
1569
1570         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1571                 goto fail;
1572
1573         if (!(b->path = default_cgroup_path(u)))
1574                 goto fail;
1575
1576         b->clean_up = true;
1577         b->only_us = true;
1578
1579         if ((r = unit_add_cgroup(u, b)) < 0)
1580                 goto fail;
1581
1582         return 0;
1583
1584 fail:
1585         free(b->path);
1586         free(b->controller);
1587         free(b);
1588
1589         return r;
1590 }
1591
1592 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1593         assert(u);
1594
1595         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1596 }
1597
1598 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1599         char *t;
1600         int r;
1601
1602         assert(u);
1603         assert(type);
1604         assert(_found);
1605
1606         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1607                 return -ENOMEM;
1608
1609         assert(!unit_has_name(u, t));
1610
1611         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1612         free(t);
1613
1614         assert(r < 0 || *_found != u);
1615
1616         return r;
1617 }
1618
1619 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1620         Unit *found;
1621         char *t;
1622
1623         assert(u);
1624         assert(type);
1625         assert(_found);
1626
1627         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1628                 return -ENOMEM;
1629
1630         assert(!unit_has_name(u, t));
1631
1632         found = manager_get_unit(u->meta.manager, t);
1633         free(t);
1634
1635         if (!found)
1636                 return -ENOENT;
1637
1638         *_found = found;
1639         return 0;
1640 }
1641
1642 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1643         Unit *u = userdata;
1644         assert(u);
1645
1646         return unit_name_to_prefix_and_instance(u->meta.id);
1647 }
1648
1649 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1650         Unit *u = userdata;
1651         assert(u);
1652
1653         return unit_name_to_prefix(u->meta.id);
1654 }
1655
1656 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1657         Unit *u = userdata;
1658         char *p, *r;
1659
1660         assert(u);
1661
1662         if (!(p = unit_name_to_prefix(u->meta.id)))
1663                 return NULL;
1664
1665         r = unit_name_unescape(p);
1666         free(p);
1667
1668         return r;
1669 }
1670
1671 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1672         Unit *u = userdata;
1673         assert(u);
1674
1675         if (u->meta.instance)
1676                 return unit_name_unescape(u->meta.instance);
1677
1678         return strdup("");
1679 }
1680
1681 char *unit_name_printf(Unit *u, const char* format) {
1682
1683         /*
1684          * This will use the passed string as format string and
1685          * replace the following specifiers:
1686          *
1687          * %n: the full id of the unit                 (foo@bar.waldo)
1688          * %N: the id of the unit without the suffix   (foo@bar)
1689          * %p: the prefix                              (foo)
1690          * %i: the instance                            (bar)
1691          */
1692
1693         const Specifier table[] = {
1694                 { 'n', specifier_string,              u->meta.id },
1695                 { 'N', specifier_prefix_and_instance, NULL },
1696                 { 'p', specifier_prefix,              NULL },
1697                 { 'i', specifier_string,              u->meta.instance },
1698                 { 0, NULL, NULL }
1699         };
1700
1701         assert(u);
1702         assert(format);
1703
1704         return specifier_printf(format, table, u);
1705 }
1706
1707 char *unit_full_printf(Unit *u, const char *format) {
1708
1709         /* This is similar to unit_name_printf() but also supports
1710          * unescaping */
1711
1712         const Specifier table[] = {
1713                 { 'n', specifier_string,              u->meta.id },
1714                 { 'N', specifier_prefix_and_instance, NULL },
1715                 { 'p', specifier_prefix,              NULL },
1716                 { 'P', specifier_prefix_unescaped,    NULL },
1717                 { 'i', specifier_string,              u->meta.instance },
1718                 { 'I', specifier_instance_unescaped,  NULL },
1719                 { 0, NULL, NULL }
1720         };
1721
1722         assert(u);
1723         assert(format);
1724
1725         return specifier_printf(format, table, u);
1726 }
1727
1728 char **unit_full_printf_strv(Unit *u, char **l) {
1729         size_t n;
1730         char **r, **i, **j;
1731
1732         /* Applies unit_full_printf to every entry in l */
1733
1734         assert(u);
1735
1736         n = strv_length(l);
1737         if (!(r = new(char*, n+1)))
1738                 return NULL;
1739
1740         for (i = l, j = r; *i; i++, j++)
1741                 if (!(*j = unit_full_printf(u, *i)))
1742                         goto fail;
1743
1744         *j = NULL;
1745         return r;
1746
1747 fail:
1748         j--;
1749         while (j >= r)
1750                 free(*j);
1751
1752         free(r);
1753
1754         return NULL;
1755 }
1756
1757 int unit_watch_bus_name(Unit *u, const char *name) {
1758         assert(u);
1759         assert(name);
1760
1761         /* Watch a specific name on the bus. We only support one unit
1762          * watching each name for now. */
1763
1764         return hashmap_put(u->meta.manager->watch_bus, name, u);
1765 }
1766
1767 void unit_unwatch_bus_name(Unit *u, const char *name) {
1768         assert(u);
1769         assert(name);
1770
1771         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1772 }
1773
1774 bool unit_can_serialize(Unit *u) {
1775         assert(u);
1776
1777         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1778 }
1779
1780 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1781         int r;
1782
1783         assert(u);
1784         assert(f);
1785         assert(fds);
1786
1787         if (!unit_can_serialize(u))
1788                 return 0;
1789
1790         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1791                 return r;
1792
1793         /* End marker */
1794         fputc('\n', f);
1795         return 0;
1796 }
1797
1798 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1799         va_list ap;
1800
1801         assert(u);
1802         assert(f);
1803         assert(key);
1804         assert(format);
1805
1806         fputs(key, f);
1807         fputc('=', f);
1808
1809         va_start(ap, format);
1810         vfprintf(f, format, ap);
1811         va_end(ap);
1812
1813         fputc('\n', f);
1814 }
1815
1816 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1817         assert(u);
1818         assert(f);
1819         assert(key);
1820         assert(value);
1821
1822         fprintf(f, "%s=%s\n", key, value);
1823 }
1824
1825 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1826         int r;
1827
1828         assert(u);
1829         assert(f);
1830         assert(fds);
1831
1832         if (!unit_can_serialize(u))
1833                 return 0;
1834
1835         for (;;) {
1836                 char line[1024], *l, *v;
1837                 size_t k;
1838
1839                 if (!fgets(line, sizeof(line), f)) {
1840                         if (feof(f))
1841                                 return 0;
1842                         return -errno;
1843                 }
1844
1845                 l = strstrip(line);
1846
1847                 /* End marker */
1848                 if (l[0] == 0)
1849                         return 0;
1850
1851                 k = strcspn(l, "=");
1852
1853                 if (l[k] == '=') {
1854                         l[k] = 0;
1855                         v = l+k+1;
1856                 } else
1857                         v = l+k;
1858
1859                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1860                         return r;
1861         }
1862 }
1863
1864 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1865         Unit *device;
1866         char *e;
1867         int r;
1868
1869         assert(u);
1870
1871         if (!what)
1872                 return 0;
1873
1874         /* Adds in links to the device node that this unit is based on */
1875
1876         if (!is_device_path(what))
1877                 return 0;
1878
1879         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1880                 return -ENOMEM;
1881
1882         r = manager_load_unit(u->meta.manager, e, NULL, &device);
1883         free(e);
1884
1885         if (r < 0)
1886                 return r;
1887
1888         if ((r = unit_add_dependency(u, UNIT_AFTER, device, true)) < 0)
1889                 return r;
1890
1891         if ((r = unit_add_dependency(u, UNIT_REQUIRES, device, true)) < 0)
1892                 return r;
1893
1894         if (wants)
1895                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1896                         return r;
1897
1898         return 0;
1899 }
1900
1901 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1902         [UNIT_SERVICE] = "service",
1903         [UNIT_TIMER] = "timer",
1904         [UNIT_SOCKET] = "socket",
1905         [UNIT_TARGET] = "target",
1906         [UNIT_DEVICE] = "device",
1907         [UNIT_MOUNT] = "mount",
1908         [UNIT_AUTOMOUNT] = "automount",
1909         [UNIT_SNAPSHOT] = "snapshot",
1910         [UNIT_SWAP] = "swap"
1911 };
1912
1913 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1914
1915 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1916         [UNIT_STUB] = "stub",
1917         [UNIT_LOADED] = "loaded",
1918         [UNIT_FAILED] = "failed",
1919         [UNIT_MERGED] = "merged"
1920 };
1921
1922 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1923
1924 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1925         [UNIT_ACTIVE] = "active",
1926         [UNIT_INACTIVE] = "inactive",
1927         [UNIT_ACTIVATING] = "activating",
1928         [UNIT_DEACTIVATING] = "deactivating"
1929 };
1930
1931 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1932
1933 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1934         [UNIT_REQUIRES] = "Requires",
1935         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
1936         [UNIT_WANTS] = "Wants",
1937         [UNIT_REQUISITE] = "Requisite",
1938         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
1939         [UNIT_REQUIRED_BY] = "RequiredBy",
1940         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
1941         [UNIT_WANTED_BY] = "WantedBy",
1942         [UNIT_CONFLICTS] = "Conflicts",
1943         [UNIT_BEFORE] = "Before",
1944         [UNIT_AFTER] = "After",
1945         [UNIT_REFERENCES] = "References",
1946         [UNIT_REFERENCED_BY] = "ReferencedBy"
1947 };
1948
1949 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
1950
1951 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1952         [KILL_CONTROL_GROUP] = "control-group",
1953         [KILL_PROCESS_GROUP] = "process-group",
1954         [KILL_PROCESS] = "process",
1955         [KILL_NONE] = "none"
1956 };
1957
1958 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);