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 (UNIT_VTABLE(u)->no_gc)
 217                 return true;
 218
 219         if (u->meta.job)
 220                 return true;
 221
 222         if (unit_active_state(u) != UNIT_INACTIVE)
 223                 return true;
 224
 225         if (UNIT_VTABLE(u)->check_gc)
 226                 if (UNIT_VTABLE(u)->check_gc(u))
 227                         return true;
 228
 229         return false;
 230 }
 231
 232 void unit_add_to_load_queue(Unit *u) {
 233         assert(u);
 234         assert(u->meta.type != _UNIT_TYPE_INVALID);
 235
 236         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 237                 return;
 238
 239         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 240         u->meta.in_load_queue = true;
 241 }
 242
 243 void unit_add_to_cleanup_queue(Unit *u) {
 244         assert(u);
 245
 246         if (u->meta.in_cleanup_queue)
 247                 return;
 248
 249         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 250         u->meta.in_cleanup_queue = true;
 251 }
 252
 253 void unit_add_to_gc_queue(Unit *u) {
 254         assert(u);
 255
 256         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 257                 return;
 258
 259         if (unit_check_gc(u))
 260                 return;
 261
 262         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 263         u->meta.in_gc_queue = true;
 264
 265         u->meta.manager->n_in_gc_queue ++;
 266
 267         if (u->meta.manager->gc_queue_timestamp <= 0)
 268                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 269 }
 270
 271 void unit_add_to_dbus_queue(Unit *u) {
 272         assert(u);
 273         assert(u->meta.type != _UNIT_TYPE_INVALID);
 274
 275         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue || set_isempty(u->meta.manager->subscribed))
 276                 return;
 277
 278         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 279         u->meta.in_dbus_queue = true;
 280 }
 281
 282 static void bidi_set_free(Unit *u, Set *s) {
 283         Iterator i;
 284         Unit *other;
 285
 286         assert(u);
 287
 288         /* Frees the set and makes sure we are dropped from the
 289          * inverse pointers */
 290
 291         SET_FOREACH(other, s, i) {
 292                 UnitDependency d;
 293
 294                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 295                         set_remove(other->meta.dependencies[d], u);
 296
 297                 unit_add_to_gc_queue(other);
 298         }
 299
 300         set_free(s);
 301 }
 302
 303 void unit_free(Unit *u) {
 304         UnitDependency d;
 305         Iterator i;
 306         char *t;
 307
 308         assert(u);
 309
 310         bus_unit_send_removed_signal(u);
 311
 312         /* Detach from next 'bigger' objects */
 313         SET_FOREACH(t, u->meta.names, i)
 314                 hashmap_remove_value(u->meta.manager->units, t, u);
 315
 316         if (u->meta.type != _UNIT_TYPE_INVALID)
 317                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 318
 319         if (u->meta.in_load_queue)
 320                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 321
 322         if (u->meta.in_dbus_queue)
 323                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 324
 325         if (u->meta.in_cleanup_queue)
 326                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 327
 328         if (u->meta.in_gc_queue) {
 329                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 330                 u->meta.manager->n_in_gc_queue--;
 331         }
 332
 333         /* Free data and next 'smaller' objects */
 334         if (u->meta.job)
 335                 job_free(u->meta.job);
 336
 337         if (u->meta.load_state != UNIT_STUB)
 338                 if (UNIT_VTABLE(u)->done)
 339                         UNIT_VTABLE(u)->done(u);
 340
 341         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 342
 343         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 344                 bidi_set_free(u, u->meta.dependencies[d]);
 345
 346         free(u->meta.description);
 347         free(u->meta.fragment_path);
 348
 349         while ((t = set_steal_first(u->meta.names)))
 350                 free(t);
 351         set_free(u->meta.names);
 352
 353         free(u->meta.instance);
 354
 355         free(u);
 356 }
 357
 358 UnitActiveState unit_active_state(Unit *u) {
 359         assert(u);
 360
 361         if (u->meta.load_state != UNIT_LOADED)
 362                 return UNIT_INACTIVE;
 363
 364         return UNIT_VTABLE(u)->active_state(u);
 365 }
 366
 367 const char* unit_sub_state_to_string(Unit *u) {
 368         assert(u);
 369
 370         return UNIT_VTABLE(u)->sub_state_to_string(u);
 371 }
 372
 373 static void complete_move(Set **s, Set **other) {
 374         assert(s);
 375         assert(other);
 376
 377         if (!*other)
 378                 return;
 379
 380         if (*s)
 381                 set_move(*s, *other);
 382         else {
 383                 *s = *other;
 384                 *other = NULL;
 385         }
 386 }
 387
 388 static void merge_names(Unit *u, Unit *other) {
 389         char *t;
 390         Iterator i;
 391
 392         assert(u);
 393         assert(other);
 394
 395         complete_move(&u->meta.names, &other->meta.names);
 396
 397         while ((t = set_steal_first(other->meta.names)))
 398                 free(t);
 399
 400         set_free(other->meta.names);
 401         other->meta.names = NULL;
 402         other->meta.id = NULL;
 403
 404         SET_FOREACH(t, u->meta.names, i)
 405                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
 406 }
 407
 408 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
 409         Iterator i;
 410         Unit *back;
 411         int r;
 412
 413         assert(u);
 414         assert(other);
 415         assert(d < _UNIT_DEPENDENCY_MAX);
 416
 417         SET_FOREACH(back, other->meta.dependencies[d], i) {
 418                 UnitDependency k;
 419
 420                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
 421                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
 422
 423                                 if (r == -EEXIST)
 424                                         set_remove(back->meta.dependencies[k], other);
 425                                 else
 426                                         assert(r == -ENOENT);
 427                         }
 428         }
 429
 430         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
 431
 432         set_free(other->meta.dependencies[d]);
 433         other->meta.dependencies[d] = NULL;
 434 }
 435
 436 int unit_merge(Unit *u, Unit *other) {
 437         UnitDependency d;
 438
 439         assert(u);
 440         assert(other);
 441         assert(u->meta.manager == other->meta.manager);
 442         assert(u->meta.type != _UNIT_TYPE_INVALID);
 443
 444         other = unit_follow_merge(other);
 445
 446         if (other == u)
 447                 return 0;
 448
 449         if (u->meta.type != other->meta.type)
 450                 return -EINVAL;
 451
 452         if (!streq_ptr(u->meta.instance, other->meta.instance))
 453                 return -EINVAL;
 454
 455         if (other->meta.load_state != UNIT_STUB &&
 456             other->meta.load_state != UNIT_FAILED)
 457                 return -EEXIST;
 458
 459         if (other->meta.job)
 460                 return -EEXIST;
 461
 462         if (unit_active_state(other) != UNIT_INACTIVE)
 463                 return -EEXIST;
 464
 465         /* Merge names */
 466         merge_names(u, other);
 467
 468         /* Merge dependencies */
 469         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 470                 merge_dependencies(u, other, d);
 471
 472         other->meta.load_state = UNIT_MERGED;
 473         other->meta.merged_into = u;
 474
 475         /* If there is still some data attached to the other node, we
 476          * don't need it anymore, and can free it. */
 477         if (other->meta.load_state != UNIT_STUB)
 478                 if (UNIT_VTABLE(other)->done)
 479                         UNIT_VTABLE(other)->done(other);
 480
 481         unit_add_to_dbus_queue(u);
 482         unit_add_to_cleanup_queue(other);
 483
 484         return 0;
 485 }
 486
 487 int unit_merge_by_name(Unit *u, const char *name) {
 488         Unit *other;
 489         int r;
 490         char *s = NULL;
 491
 492         assert(u);
 493         assert(name);
 494
 495         if (unit_name_is_template(name)) {
 496                 if (!u->meta.instance)
 497                         return -EINVAL;
 498
 499                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
 500                         return -ENOMEM;
 501
 502                 name = s;
 503         }
 504
 505         if (!(other = manager_get_unit(u->meta.manager, name)))
 506                 r = unit_add_name(u, name);
 507         else
 508                 r = unit_merge(u, other);
 509
 510         free(s);
 511         return r;
 512 }
 513
 514 Unit* unit_follow_merge(Unit *u) {
 515         assert(u);
 516
 517         while (u->meta.load_state == UNIT_MERGED)
 518                 assert_se(u = u->meta.merged_into);
 519
 520         return u;
 521 }
 522
 523 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 524         int r;
 525
 526         assert(u);
 527         assert(c);
 528
 529         if (c->std_output != EXEC_OUTPUT_KERNEL && c->std_output != EXEC_OUTPUT_SYSLOG)
 530                 return 0;
 531
 532         /* If syslog or kernel logging is requested, make sure our own
 533          * logging daemon is run first. */
 534
 535         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 536                 return r;
 537
 538         if (u->meta.manager->running_as != MANAGER_SESSION)
 539                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 540                         return r;
 541
 542         return 0;
 543 }
 544
 545 const char *unit_description(Unit *u) {
 546         assert(u);
 547
 548         if (u->meta.description)
 549                 return u->meta.description;
 550
 551         return u->meta.id;
 552 }
 553
 554 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 555         char *t;
 556         UnitDependency d;
 557         Iterator i;
 558         char *p2;
 559         const char *prefix2;
 560         CGroupBonding *b;
 561         char timestamp1[FORMAT_TIMESTAMP_MAX], timestamp2[FORMAT_TIMESTAMP_MAX];
 562
 563         assert(u);
 564         assert(u->meta.type >= 0);
 565
 566         if (!prefix)
 567                 prefix = "";
 568         p2 = strappend(prefix, "\t");
 569         prefix2 = p2 ? p2 : prefix;
 570
 571         fprintf(f,
 572                 "%s-> Unit %s:\n"
 573                 "%s\tDescription: %s\n"
 574                 "%s\tInstance: %s\n"
 575                 "%s\tUnit Load State: %s\n"
 576                 "%s\tUnit Active State: %s\n"
 577                 "%s\tActive Enter Timestamp: %s\n"
 578                 "%s\tActive Exit Timestamp: %s\n"
 579                 "%s\tGC Check Good: %s\n",
 580                 prefix, u->meta.id,
 581                 prefix, unit_description(u),
 582                 prefix, strna(u->meta.instance),
 583                 prefix, unit_load_state_to_string(u->meta.load_state),
 584                 prefix, unit_active_state_to_string(unit_active_state(u)),
 585                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.active_enter_timestamp)),
 586                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_exit_timestamp)),
 587                 prefix, yes_no(unit_check_gc(u)));
 588
 589         SET_FOREACH(t, u->meta.names, i)
 590                 fprintf(f, "%s\tName: %s\n", prefix, t);
 591
 592         if (u->meta.fragment_path)
 593                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
 594
 595         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 596                 Unit *other;
 597
 598                 SET_FOREACH(other, u->meta.dependencies[d], i)
 599                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
 600         }
 601
 602         if (u->meta.load_state == UNIT_LOADED) {
 603                 fprintf(f,
 604                         "%s\tRecursive Stop: %s\n"
 605                         "%s\tStop When Unneeded: %s\n",
 606                         prefix, yes_no(u->meta.recursive_stop),
 607                         prefix, yes_no(u->meta.stop_when_unneeded));
 608
 609                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
 610                         fprintf(f, "%s\tControlGroup: %s:%s\n",
 611                                 prefix, b->controller, b->path);
 612
 613                 if (UNIT_VTABLE(u)->dump)
 614                         UNIT_VTABLE(u)->dump(u, f, prefix2);
 615
 616         } else if (u->meta.load_state == UNIT_MERGED)
 617                 fprintf(f,
 618                         "%s\tMerged into: %s\n",
 619                         prefix, u->meta.merged_into->meta.id);
 620
 621         if (u->meta.job)
 622                 job_dump(u->meta.job, f, prefix2);
 623
 624         free(p2);
 625 }
 626
 627 /* Common implementation for multiple backends */
 628 int unit_load_fragment_and_dropin(Unit *u) {
 629         int r;
 630
 631         assert(u);
 632
 633         /* Load a .service file */
 634         if ((r = unit_load_fragment(u)) < 0)
 635                 return r;
 636
 637         if (u->meta.load_state == UNIT_STUB)
 638                 return -ENOENT;
 639
 640         /* Load drop-in directory data */
 641         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 642                 return r;
 643
 644         return 0;
 645 }
 646
 647 /* Common implementation for multiple backends */
 648 int unit_load_fragment_and_dropin_optional(Unit *u) {
 649         int r;
 650
 651         assert(u);
 652
 653         /* Same as unit_load_fragment_and_dropin(), but whether
 654          * something can be loaded or not doesn't matter. */
 655
 656         /* Load a .service file */
 657         if ((r = unit_load_fragment(u)) < 0)
 658                 return r;
 659
 660         if (u->meta.load_state == UNIT_STUB)
 661                 u->meta.load_state = UNIT_LOADED;
 662
 663         /* Load drop-in directory data */
 664         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 665                 return r;
 666
 667         return 0;
 668 }
 669
 670 /* Common implementation for multiple backends */
 671 int unit_load_nop(Unit *u) {
 672         assert(u);
 673
 674         if (u->meta.load_state == UNIT_STUB)
 675                 u->meta.load_state = UNIT_LOADED;
 676
 677         return 0;
 678 }
 679
 680 int unit_load(Unit *u) {
 681         int r;
 682
 683         assert(u);
 684
 685         if (u->meta.in_load_queue) {
 686                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 687                 u->meta.in_load_queue = false;
 688         }
 689
 690         if (u->meta.type == _UNIT_TYPE_INVALID)
 691                 return -EINVAL;
 692
 693         if (u->meta.load_state != UNIT_STUB)
 694                 return 0;
 695
 696         if (UNIT_VTABLE(u)->load)
 697                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
 698                         goto fail;
 699
 700         if (u->meta.load_state == UNIT_STUB) {
 701                 r = -ENOENT;
 702                 goto fail;
 703         }
 704
 705         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
 706
 707         unit_add_to_dbus_queue(unit_follow_merge(u));
 708         unit_add_to_gc_queue(u);
 709
 710         return 0;
 711
 712 fail:
 713         u->meta.load_state = UNIT_FAILED;
 714         unit_add_to_dbus_queue(u);
 715
 716         log_debug("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
 717
 718         return r;
 719 }
 720
 721 /* Errors:
 722  *         -EBADR:    This unit type does not support starting.
 723  *         -EALREADY: Unit is already started.
 724  *         -EAGAIN:   An operation is already in progress. Retry later.
 725  */
 726 int unit_start(Unit *u) {
 727         UnitActiveState state;
 728
 729         assert(u);
 730
 731         /* If this is already (being) started, then this will
 732          * succeed. Note that this will even succeed if this unit is
 733          * not startable by the user. This is relied on to detect when
 734          * we need to wait for units and when waiting is finished. */
 735         state = unit_active_state(u);
 736         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 737                 return -EALREADY;
 738
 739         /* If it is stopped, but we cannot start it, then fail */
 740         if (!UNIT_VTABLE(u)->start)
 741                 return -EBADR;
 742
 743         /* We don't suppress calls to ->start() here when we are
 744          * already starting, to allow this request to be used as a
 745          * "hurry up" call, for example when the unit is in some "auto
 746          * restart" state where it waits for a holdoff timer to elapse
 747          * before it will start again. */
 748
 749         unit_add_to_dbus_queue(u);
 750         return UNIT_VTABLE(u)->start(u);
 751 }
 752
 753 bool unit_can_start(Unit *u) {
 754         assert(u);
 755
 756         return !!UNIT_VTABLE(u)->start;
 757 }
 758
 759 /* Errors:
 760  *         -EBADR:    This unit type does not support stopping.
 761  *         -EALREADY: Unit is already stopped.
 762  *         -EAGAIN:   An operation is already in progress. Retry later.
 763  */
 764 int unit_stop(Unit *u) {
 765         UnitActiveState state;
 766
 767         assert(u);
 768
 769         state = unit_active_state(u);
 770         if (state == UNIT_INACTIVE)
 771                 return -EALREADY;
 772
 773         if (!UNIT_VTABLE(u)->stop)
 774                 return -EBADR;
 775
 776         unit_add_to_dbus_queue(u);
 777         return UNIT_VTABLE(u)->stop(u);
 778 }
 779
 780 /* Errors:
 781  *         -EBADR:    This unit type does not support reloading.
 782  *         -ENOEXEC:  Unit is not started.
 783  *         -EAGAIN:   An operation is already in progress. Retry later.
 784  */
 785 int unit_reload(Unit *u) {
 786         UnitActiveState state;
 787
 788         assert(u);
 789
 790         if (!unit_can_reload(u))
 791                 return -EBADR;
 792
 793         state = unit_active_state(u);
 794         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 795                 return -EALREADY;
 796
 797         if (unit_active_state(u) != UNIT_ACTIVE)
 798                 return -ENOEXEC;
 799
 800         unit_add_to_dbus_queue(u);
 801         return UNIT_VTABLE(u)->reload(u);
 802 }
 803
 804 bool unit_can_reload(Unit *u) {
 805         assert(u);
 806
 807         if (!UNIT_VTABLE(u)->reload)
 808                 return false;
 809
 810         if (!UNIT_VTABLE(u)->can_reload)
 811                 return true;
 812
 813         return UNIT_VTABLE(u)->can_reload(u);
 814 }
 815
 816 static void unit_check_uneeded(Unit *u) {
 817         Iterator i;
 818         Unit *other;
 819
 820         assert(u);
 821
 822         /* If this service shall be shut down when unneeded then do
 823          * so. */
 824
 825         if (!u->meta.stop_when_unneeded)
 826                 return;
 827
 828         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 829                 return;
 830
 831         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 832                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 833                         return;
 834
 835         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 836                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 837                         return;
 838
 839         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 840                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 841                         return;
 842
 843         log_debug("Service %s is not needed anymore. Stopping.", u->meta.id);
 844
 845         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 846         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 847 }
 848
 849 static void retroactively_start_dependencies(Unit *u) {
 850         Iterator i;
 851         Unit *other;
 852
 853         assert(u);
 854         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 855
 856         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 857                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 858                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 859
 860         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 861                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 862                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 863
 864         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 865                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 866                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 867
 868         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 869                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 870                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 871
 872         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 873                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 874                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 875 }
 876
 877 static void retroactively_stop_dependencies(Unit *u) {
 878         Iterator i;
 879         Unit *other;
 880
 881         assert(u);
 882         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 883
 884         if (u->meta.recursive_stop) {
 885                 /* Pull down units need us recursively if enabled */
 886                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 887                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 888                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 889         }
 890
 891         /* Garbage collect services that might not be needed anymore, if enabled */
 892         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 893                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 894                         unit_check_uneeded(other);
 895         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 896                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 897                         unit_check_uneeded(other);
 898         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 899                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 900                         unit_check_uneeded(other);
 901         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 902                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 903                         unit_check_uneeded(other);
 904         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
 905                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 906                         unit_check_uneeded(other);
 907 }
 908
 909 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 910         bool unexpected = false;
 911
 912         assert(u);
 913         assert(os < _UNIT_ACTIVE_STATE_MAX);
 914         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 915
 916         /* Note that this is called for all low-level state changes,
 917          * even if they might map to the same high-level
 918          * UnitActiveState! That means that ns == os is OK an expected
 919          * behaviour here. For example: if a mount point is remounted
 920          * this function will be called too and the utmp code below
 921          * relies on that! */
 922
 923         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 924                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 925         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 926                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 927
 928         if (u->meta.job) {
 929
 930                 if (u->meta.job->state == JOB_WAITING)
 931
 932                         /* So we reached a different state for this
 933                          * job. Let's see if we can run it now if it
 934                          * failed previously due to EAGAIN. */
 935                         job_add_to_run_queue(u->meta.job);
 936
 937                 else {
 938                         assert(u->meta.job->state == JOB_RUNNING);
 939
 940                         /* Let's check whether this state change
 941                          * constitutes a finished job, or maybe
 942                          * cotradicts a running job and hence needs to
 943                          * invalidate jobs. */
 944
 945                         switch (u->meta.job->type) {
 946
 947                         case JOB_START:
 948                         case JOB_VERIFY_ACTIVE:
 949
 950                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 951                                         job_finish_and_invalidate(u->meta.job, true);
 952                                 else if (ns != UNIT_ACTIVATING) {
 953                                         unexpected = true;
 954                                         job_finish_and_invalidate(u->meta.job, false);
 955                                 }
 956
 957                                 break;
 958
 959                         case JOB_RELOAD:
 960                         case JOB_RELOAD_OR_START:
 961
 962                                 if (ns == UNIT_ACTIVE)
 963                                         job_finish_and_invalidate(u->meta.job, true);
 964                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_ACTIVE_RELOADING) {
 965                                         unexpected = true;
 966                                         job_finish_and_invalidate(u->meta.job, false);
 967                                 }
 968
 969                                 break;
 970
 971                         case JOB_STOP:
 972                         case JOB_RESTART:
 973                         case JOB_TRY_RESTART:
 974
 975                                 if (ns == UNIT_INACTIVE)
 976                                         job_finish_and_invalidate(u->meta.job, true);
 977                                 else if (ns != UNIT_DEACTIVATING) {
 978                                         unexpected = true;
 979                                         job_finish_and_invalidate(u->meta.job, false);
 980                                 }
 981
 982                                 break;
 983
 984                         default:
 985                                 assert_not_reached("Job type unknown");
 986                         }
 987                 }
 988         }
 989
 990         /* If this state change happened without being requested by a
 991          * job, then let's retroactively start or stop dependencies */
 992
 993         if (unexpected) {
 994                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 995                         retroactively_start_dependencies(u);
 996                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 997                         retroactively_stop_dependencies(u);
 998         }
 999
1000         /* Some names are special */
1001         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1002                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1003                         /* The bus just might have become available,
1004                          * hence try to connect to it, if we aren't
1005                          * yet connected. */
1006                         bus_init_system(u->meta.manager);
1007                         bus_init_api(u->meta.manager);
1008                 }
1009
1010                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1011                         /* The syslog daemon just might have become
1012                          * available, hence try to connect to it, if
1013                          * we aren't yet connected. */
1014                         log_open_syslog();
1015
1016                 if (u->meta.type == UNIT_MOUNT)
1017                         /* Another directory became available, let's
1018                          * check if that is enough to write our utmp
1019                          * entry. */
1020                         manager_write_utmp_reboot(u->meta.manager);
1021
1022                 if (u->meta.type == UNIT_TARGET)
1023                         /* A target got activated, maybe this is a runlevel? */
1024                         manager_write_utmp_runlevel(u->meta.manager, u);
1025
1026         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1027
1028                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1029                         /* The syslog daemon might just have
1030                          * terminated, hence try to disconnect from
1031                          * it. */
1032                         log_close_syslog();
1033
1034                 /* We don't care about D-Bus here, since we'll get an
1035                  * asynchronous notification for it anyway. */
1036         }
1037
1038         /* Maybe we finished startup and are now ready for being
1039          * stopped because unneeded? */
1040         unit_check_uneeded(u);
1041
1042         unit_add_to_dbus_queue(u);
1043         unit_add_to_gc_queue(u);
1044 }
1045
1046 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1047         struct epoll_event ev;
1048
1049         assert(u);
1050         assert(fd >= 0);
1051         assert(w);
1052         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1053
1054         zero(ev);
1055         ev.data.ptr = w;
1056         ev.events = events;
1057
1058         if (epoll_ctl(u->meta.manager->epoll_fd,
1059                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1060                       fd,
1061                       &ev) < 0)
1062                 return -errno;
1063
1064         w->fd = fd;
1065         w->type = WATCH_FD;
1066         w->data.unit = u;
1067
1068         return 0;
1069 }
1070
1071 void unit_unwatch_fd(Unit *u, Watch *w) {
1072         assert(u);
1073         assert(w);
1074
1075         if (w->type == WATCH_INVALID)
1076                 return;
1077
1078         assert(w->type == WATCH_FD);
1079         assert(w->data.unit == u);
1080         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1081
1082         w->fd = -1;
1083         w->type = WATCH_INVALID;
1084         w->data.unit = NULL;
1085 }
1086
1087 int unit_watch_pid(Unit *u, pid_t pid) {
1088         assert(u);
1089         assert(pid >= 1);
1090
1091         /* Watch a specific PID. We only support one unit watching
1092          * each PID for now. */
1093
1094         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1095 }
1096
1097 void unit_unwatch_pid(Unit *u, pid_t pid) {
1098         assert(u);
1099         assert(pid >= 1);
1100
1101         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1102 }
1103
1104 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1105         struct itimerspec its;
1106         int flags, fd;
1107         bool ours;
1108
1109         assert(u);
1110         assert(w);
1111         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1112
1113         /* This will try to reuse the old timer if there is one */
1114
1115         if (w->type == WATCH_TIMER) {
1116                 ours = false;
1117                 fd = w->fd;
1118         } else {
1119                 ours = true;
1120                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1121                         return -errno;
1122         }
1123
1124         zero(its);
1125
1126         if (delay <= 0) {
1127                 /* Set absolute time in the past, but not 0, since we
1128                  * don't want to disarm the timer */
1129                 its.it_value.tv_sec = 0;
1130                 its.it_value.tv_nsec = 1;
1131
1132                 flags = TFD_TIMER_ABSTIME;
1133         } else {
1134                 timespec_store(&its.it_value, delay);
1135                 flags = 0;
1136         }
1137
1138         /* This will also flush the elapse counter */
1139         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1140                 goto fail;
1141
1142         if (w->type == WATCH_INVALID) {
1143                 struct epoll_event ev;
1144
1145                 zero(ev);
1146                 ev.data.ptr = w;
1147                 ev.events = EPOLLIN;
1148
1149                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1150                         goto fail;
1151         }
1152
1153         w->fd = fd;
1154         w->type = WATCH_TIMER;
1155         w->data.unit = u;
1156
1157         return 0;
1158
1159 fail:
1160         if (ours)
1161                 close_nointr_nofail(fd);
1162
1163         return -errno;
1164 }
1165
1166 void unit_unwatch_timer(Unit *u, Watch *w) {
1167         assert(u);
1168         assert(w);
1169
1170         if (w->type == WATCH_INVALID)
1171                 return;
1172
1173         assert(w->type == WATCH_TIMER && w->data.unit == u);
1174
1175         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1176         close_nointr_nofail(w->fd);
1177
1178         w->fd = -1;
1179         w->type = WATCH_INVALID;
1180         w->data.unit = NULL;
1181 }
1182
1183 bool unit_job_is_applicable(Unit *u, JobType j) {
1184         assert(u);
1185         assert(j >= 0 && j < _JOB_TYPE_MAX);
1186
1187         switch (j) {
1188
1189         case JOB_VERIFY_ACTIVE:
1190         case JOB_START:
1191                 return true;
1192
1193         case JOB_STOP:
1194         case JOB_RESTART:
1195         case JOB_TRY_RESTART:
1196                 return unit_can_start(u);
1197
1198         case JOB_RELOAD:
1199                 return unit_can_reload(u);
1200
1201         case JOB_RELOAD_OR_START:
1202                 return unit_can_reload(u) && unit_can_start(u);
1203
1204         default:
1205                 assert_not_reached("Invalid job type");
1206         }
1207 }
1208
1209 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1210
1211         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1212                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1213                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1214                 [UNIT_WANTS] = UNIT_WANTED_BY,
1215                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1216                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1217                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1218                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1219                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1220                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1221                 [UNIT_BEFORE] = UNIT_AFTER,
1222                 [UNIT_AFTER] = UNIT_BEFORE,
1223                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1224                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1225         };
1226         int r, q = 0, v = 0, w = 0;
1227
1228         assert(u);
1229         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1230         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1231         assert(other);
1232
1233         /* We won't allow dependencies on ourselves. We will not
1234          * consider them an error however. */
1235         if (u == other)
1236                 return 0;
1237
1238         if (UNIT_VTABLE(u)->no_requires &&
1239             (d == UNIT_REQUIRES ||
1240              d == UNIT_REQUIRES_OVERRIDABLE ||
1241              d == UNIT_REQUISITE ||
1242              d == UNIT_REQUISITE_OVERRIDABLE)) {
1243                     return -EINVAL;
1244         }
1245
1246         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1247             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1248                 return r;
1249
1250         if (add_reference)
1251                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1252                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1253                         return r;
1254
1255         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1256                 return q;
1257
1258         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1259                 r = v;
1260                 goto fail;
1261         }
1262
1263         if (add_reference) {
1264                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1265                         r = w;
1266                         goto fail;
1267                 }
1268
1269                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1270                         goto fail;
1271         }
1272
1273         unit_add_to_dbus_queue(u);
1274         return 0;
1275
1276 fail:
1277         if (q > 0)
1278                 set_remove(u->meta.dependencies[d], other);
1279
1280         if (v > 0)
1281                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1282
1283         if (w > 0)
1284                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1285
1286         return r;
1287 }
1288
1289 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1290         char *s;
1291
1292         assert(u);
1293         assert(name || path);
1294
1295         if (!name)
1296                 name = file_name_from_path(path);
1297
1298         if (!unit_name_is_template(name)) {
1299                 *p = NULL;
1300                 return name;
1301         }
1302
1303         if (u->meta.instance)
1304                 s = unit_name_replace_instance(name, u->meta.instance);
1305         else {
1306                 char *i;
1307
1308                 if (!(i = unit_name_to_prefix(u->meta.id)))
1309                         return NULL;
1310
1311                 s = unit_name_replace_instance(name, i);
1312                 free(i);
1313         }
1314
1315         if (!s)
1316                 return NULL;
1317
1318         *p = s;
1319         return s;
1320 }
1321
1322 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1323         Unit *other;
1324         int r;
1325         char *s;
1326
1327         assert(u);
1328         assert(name || path);
1329
1330         if (!(name = resolve_template(u, name, path, &s)))
1331                 return -ENOMEM;
1332
1333         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1334                 goto finish;
1335
1336         r = unit_add_dependency(u, d, other, add_reference);
1337
1338 finish:
1339         free(s);
1340         return r;
1341 }
1342
1343 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1344         Unit *other;
1345         int r;
1346         char *s;
1347
1348         assert(u);
1349         assert(name || path);
1350
1351         if (!(name = resolve_template(u, name, path, &s)))
1352                 return -ENOMEM;
1353
1354         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1355                 goto finish;
1356
1357         r = unit_add_dependency(other, d, u, add_reference);
1358
1359 finish:
1360         free(s);
1361         return r;
1362 }
1363
1364 int set_unit_path(const char *p) {
1365         char *cwd, *c;
1366         int r;
1367
1368         /* This is mostly for debug purposes */
1369
1370         if (path_is_absolute(p)) {
1371                 if (!(c = strdup(p)))
1372                         return -ENOMEM;
1373         } else {
1374                 if (!(cwd = get_current_dir_name()))
1375                         return -errno;
1376
1377                 r = asprintf(&c, "%s/%s", cwd, p);
1378                 free(cwd);
1379
1380                 if (r < 0)
1381                         return -ENOMEM;
1382         }
1383
1384         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1385                 r = -errno;
1386                 free(c);
1387                 return r;
1388         }
1389
1390         return 0;
1391 }
1392
1393 char *unit_dbus_path(Unit *u) {
1394         char *p, *e;
1395
1396         assert(u);
1397
1398         if (!(e = bus_path_escape(u->meta.id)))
1399                 return NULL;
1400
1401         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1402                 free(e);
1403                 return NULL;
1404         }
1405
1406         free(e);
1407         return p;
1408 }
1409
1410 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1411         CGroupBonding *l;
1412         int r;
1413
1414         assert(u);
1415         assert(b);
1416         assert(b->path);
1417
1418         /* Ensure this hasn't been added yet */
1419         assert(!b->unit);
1420
1421         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1422         LIST_PREPEND(CGroupBonding, by_path, l, b);
1423
1424         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1425                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1426                 return r;
1427         }
1428
1429         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1430         b->unit = u;
1431
1432         return 0;
1433 }
1434
1435 static char *default_cgroup_path(Unit *u) {
1436         char *p;
1437         int r;
1438
1439         assert(u);
1440
1441         if (u->meta.instance) {
1442                 char *t;
1443
1444                 if (!(t = unit_name_template(u->meta.id)))
1445                         return NULL;
1446
1447                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1448                 free(t);
1449         } else
1450                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1451
1452         return r < 0 ? NULL : p;
1453 }
1454
1455 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1456         size_t n;
1457         char *controller = NULL, *path = NULL;
1458         CGroupBonding *b = NULL;
1459         int r;
1460
1461         assert(u);
1462         assert(name);
1463
1464         /* Detect controller name */
1465         n = strcspn(name, ":");
1466
1467         if (name[n] == 0 ||
1468             (name[n] == ':' && name[n+1] == 0)) {
1469
1470                 /* Only controller name, no path? */
1471
1472                 if (!(path = default_cgroup_path(u)))
1473                         return -ENOMEM;
1474
1475         } else {
1476                 const char *p;
1477
1478                 /* Controller name, and path. */
1479                 p = name+n+1;
1480
1481                 if (!path_is_absolute(p))
1482                         return -EINVAL;
1483
1484                 if (!(path = strdup(p)))
1485                         return -ENOMEM;
1486         }
1487
1488         if (n > 0)
1489                 controller = strndup(name, n);
1490         else
1491                 controller = strdup(u->meta.manager->cgroup_controller);
1492
1493         if (!controller) {
1494                 r = -ENOMEM;
1495                 goto fail;
1496         }
1497
1498         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1499                 r = -EEXIST;
1500                 goto fail;
1501         }
1502
1503         if (!(b = new0(CGroupBonding, 1))) {
1504                 r = -ENOMEM;
1505                 goto fail;
1506         }
1507
1508         b->controller = controller;
1509         b->path = path;
1510         b->only_us = false;
1511         b->clean_up = false;
1512
1513         if ((r = unit_add_cgroup(u, b)) < 0)
1514                 goto fail;
1515
1516         return 0;
1517
1518 fail:
1519         free(path);
1520         free(controller);
1521         free(b);
1522
1523         return r;
1524 }
1525
1526 int unit_add_default_cgroup(Unit *u) {
1527         CGroupBonding *b;
1528         int r = -ENOMEM;
1529
1530         assert(u);
1531
1532         /* Adds in the default cgroup data, if it wasn't specified yet */
1533
1534         if (unit_get_default_cgroup(u))
1535                 return 0;
1536
1537         if (!(b = new0(CGroupBonding, 1)))
1538                 return -ENOMEM;
1539
1540         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1541                 goto fail;
1542
1543         if (!(b->path = default_cgroup_path(u)))
1544                 goto fail;
1545
1546         b->clean_up = true;
1547         b->only_us = true;
1548
1549         if ((r = unit_add_cgroup(u, b)) < 0)
1550                 goto fail;
1551
1552         return 0;
1553
1554 fail:
1555         free(b->path);
1556         free(b->controller);
1557         free(b);
1558
1559         return r;
1560 }
1561
1562 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1563         assert(u);
1564
1565         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1566 }
1567
1568 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1569         char *t;
1570         int r;
1571
1572         assert(u);
1573         assert(type);
1574         assert(_found);
1575
1576         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1577                 return -ENOMEM;
1578
1579         assert(!unit_has_name(u, t));
1580
1581         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1582         free(t);
1583
1584         assert(r < 0 || *_found != u);
1585
1586         return r;
1587 }
1588
1589 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1590         Unit *found;
1591         char *t;
1592
1593         assert(u);
1594         assert(type);
1595         assert(_found);
1596
1597         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1598                 return -ENOMEM;
1599
1600         assert(!unit_has_name(u, t));
1601
1602         found = manager_get_unit(u->meta.manager, t);
1603         free(t);
1604
1605         if (!found)
1606                 return -ENOENT;
1607
1608         *_found = found;
1609         return 0;
1610 }
1611
1612 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1613         Unit *u = userdata;
1614         assert(u);
1615
1616         return unit_name_to_prefix_and_instance(u->meta.id);
1617 }
1618
1619 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1620         Unit *u = userdata;
1621         assert(u);
1622
1623         return unit_name_to_prefix(u->meta.id);
1624 }
1625
1626 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1627         Unit *u = userdata;
1628         char *p, *r;
1629
1630         assert(u);
1631
1632         if (!(p = unit_name_to_prefix(u->meta.id)))
1633                 return NULL;
1634
1635         r = unit_name_unescape(p);
1636         free(p);
1637
1638         return r;
1639 }
1640
1641 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1642         Unit *u = userdata;
1643         assert(u);
1644
1645         if (u->meta.instance)
1646                 return unit_name_unescape(u->meta.instance);
1647
1648         return strdup("");
1649 }
1650
1651 char *unit_name_printf(Unit *u, const char* format) {
1652
1653         /*
1654          * This will use the passed string as format string and
1655          * replace the following specifiers:
1656          *
1657          * %n: the full id of the unit                 (foo@bar.waldo)
1658          * %N: the id of the unit without the suffix   (foo@bar)
1659          * %p: the prefix                              (foo)
1660          * %i: the instance                            (bar)
1661          */
1662
1663         const Specifier table[] = {
1664                 { 'n', specifier_string,              u->meta.id },
1665                 { 'N', specifier_prefix_and_instance, NULL },
1666                 { 'p', specifier_prefix,              NULL },
1667                 { 'i', specifier_string,              u->meta.instance },
1668                 { 0, NULL, NULL }
1669         };
1670
1671         assert(u);
1672         assert(format);
1673
1674         return specifier_printf(format, table, u);
1675 }
1676
1677 char *unit_full_printf(Unit *u, const char *format) {
1678
1679         /* This is similar to unit_name_printf() but also supports
1680          * unescaping */
1681
1682         const Specifier table[] = {
1683                 { 'n', specifier_string,              u->meta.id },
1684                 { 'N', specifier_prefix_and_instance, NULL },
1685                 { 'p', specifier_prefix,              NULL },
1686                 { 'P', specifier_prefix_unescaped,    NULL },
1687                 { 'i', specifier_string,              u->meta.instance },
1688                 { 'I', specifier_instance_unescaped,  NULL },
1689                 { 0, NULL, NULL }
1690         };
1691
1692         assert(u);
1693         assert(format);
1694
1695         return specifier_printf(format, table, u);
1696 }
1697
1698 char **unit_full_printf_strv(Unit *u, char **l) {
1699         size_t n;
1700         char **r, **i, **j;
1701
1702         /* Applies unit_full_printf to every entry in l */
1703
1704         assert(u);
1705
1706         n = strv_length(l);
1707         if (!(r = new(char*, n+1)))
1708                 return NULL;
1709
1710         for (i = l, j = r; *i; i++, j++)
1711                 if (!(*j = unit_full_printf(u, *i)))
1712                         goto fail;
1713
1714         *j = NULL;
1715         return r;
1716
1717 fail:
1718         j--;
1719         while (j >= r)
1720                 free(*j);
1721
1722         free(r);
1723
1724         return NULL;
1725 }
1726
1727 int unit_watch_bus_name(Unit *u, const char *name) {
1728         assert(u);
1729         assert(name);
1730
1731         /* Watch a specific name on the bus. We only support one unit
1732          * watching each name for now. */
1733
1734         return hashmap_put(u->meta.manager->watch_bus, name, u);
1735 }
1736
1737 void unit_unwatch_bus_name(Unit *u, const char *name) {
1738         assert(u);
1739         assert(name);
1740
1741         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1742 }
1743
1744 bool unit_can_serialize(Unit *u) {
1745         assert(u);
1746
1747         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1748 }
1749
1750 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1751         int r;
1752
1753         assert(u);
1754         assert(f);
1755         assert(fds);
1756
1757         if (!unit_can_serialize(u))
1758                 return 0;
1759
1760         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1761                 return r;
1762
1763         /* End marker */
1764         fputc('\n', f);
1765         return 0;
1766 }
1767
1768 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1769         va_list ap;
1770
1771         assert(u);
1772         assert(f);
1773         assert(key);
1774         assert(format);
1775
1776         fputs(key, f);
1777         fputc('=', f);
1778
1779         va_start(ap, format);
1780         vfprintf(f, format, ap);
1781         va_end(ap);
1782
1783         fputc('\n', f);
1784 }
1785
1786 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1787         assert(u);
1788         assert(f);
1789         assert(key);
1790         assert(value);
1791
1792         fprintf(f, "%s=%s\n", key, value);
1793 }
1794
1795 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1796         int r;
1797
1798         assert(u);
1799         assert(f);
1800         assert(fds);
1801
1802         if (!unit_can_serialize(u))
1803                 return 0;
1804
1805         for (;;) {
1806                 char line[1024], *l, *v;
1807                 size_t k;
1808
1809                 if (!fgets(line, sizeof(line), f)) {
1810                         if (feof(f))
1811                                 return 0;
1812                         return -errno;
1813                 }
1814
1815                 l = strstrip(line);
1816
1817                 /* End marker */
1818                 if (l[0] == 0)
1819                         return 0;
1820
1821                 k = strcspn(l, "=");
1822
1823                 if (l[k] == '=') {
1824                         l[k] = 0;
1825                         v = l+k+1;
1826                 } else
1827                         v = l+k;
1828
1829                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1830                         return r;
1831         }
1832 }
1833
1834 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1835         Unit *device;
1836         char *e;
1837         int r;
1838
1839         assert(u);
1840
1841         if (!what)
1842                 return 0;
1843
1844         /* Adds in links to the device node that this unit is based on */
1845
1846         if (!path_startswith(what, "/dev/") && !path_startswith(what, "/sys/"))
1847                 return 0;
1848
1849         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1850                 return -ENOMEM;
1851
1852         r = manager_load_unit(u->meta.manager, e, NULL, &device);
1853         free(e);
1854
1855         if (r < 0)
1856                 return r;
1857
1858         if ((r = unit_add_dependency(u, UNIT_AFTER, device, true)) < 0)
1859                 return r;
1860
1861         if ((r = unit_add_dependency(u, UNIT_REQUIRES, device, true)) < 0)
1862                 return r;
1863
1864         if (wants)
1865                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1866                         return r;
1867
1868         return 0;
1869 }
1870
1871 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1872         [UNIT_SERVICE] = "service",
1873         [UNIT_TIMER] = "timer",
1874         [UNIT_SOCKET] = "socket",
1875         [UNIT_TARGET] = "target",
1876         [UNIT_DEVICE] = "device",
1877         [UNIT_MOUNT] = "mount",
1878         [UNIT_AUTOMOUNT] = "automount",
1879         [UNIT_SNAPSHOT] = "snapshot",
1880         [UNIT_SWAP] = "swap"
1881 };
1882
1883 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1884
1885 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1886         [UNIT_STUB] = "stub",
1887         [UNIT_LOADED] = "loaded",
1888         [UNIT_FAILED] = "failed",
1889         [UNIT_MERGED] = "merged"
1890 };
1891
1892 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1893
1894 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1895         [UNIT_ACTIVE] = "active",
1896         [UNIT_INACTIVE] = "inactive",
1897         [UNIT_ACTIVATING] = "activating",
1898         [UNIT_DEACTIVATING] = "deactivating"
1899 };
1900
1901 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1902
1903 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1904         [UNIT_REQUIRES] = "Requires",
1905         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
1906         [UNIT_WANTS] = "Wants",
1907         [UNIT_REQUISITE] = "Requisite",
1908         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
1909         [UNIT_REQUIRED_BY] = "RequiredBy",
1910         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
1911         [UNIT_WANTED_BY] = "WantedBy",
1912         [UNIT_CONFLICTS] = "Conflicts",
1913         [UNIT_BEFORE] = "Before",
1914         [UNIT_AFTER] = "After",
1915         [UNIT_REFERENCES] = "References",
1916         [UNIT_REFERENCED_BY] = "ReferencedBy"
1917 };
1918
1919 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
1920
1921 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1922         [KILL_CONTROL_GROUP] = "control-group",
1923         [KILL_PROCESS_GROUP] = "process-group",
1924         [KILL_PROCESS] = "process",
1925         [KILL_NONE] = "none"
1926 };
1927
1928 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);