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)
 276                 return;
 277
 278         if (set_isempty(u->meta.manager->subscribed)) {
 279                 u->meta.sent_dbus_new_signal = true;
 280                 return;
 281         }
 282
 283         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 284         u->meta.in_dbus_queue = true;
 285 }
 286
 287 static void bidi_set_free(Unit *u, Set *s) {
 288         Iterator i;
 289         Unit *other;
 290
 291         assert(u);
 292
 293         /* Frees the set and makes sure we are dropped from the
 294          * inverse pointers */
 295
 296         SET_FOREACH(other, s, i) {
 297                 UnitDependency d;
 298
 299                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 300                         set_remove(other->meta.dependencies[d], u);
 301
 302                 unit_add_to_gc_queue(other);
 303         }
 304
 305         set_free(s);
 306 }
 307
 308 void unit_free(Unit *u) {
 309         UnitDependency d;
 310         Iterator i;
 311         char *t;
 312
 313         assert(u);
 314
 315         bus_unit_send_removed_signal(u);
 316
 317         /* Detach from next 'bigger' objects */
 318         SET_FOREACH(t, u->meta.names, i)
 319                 hashmap_remove_value(u->meta.manager->units, t, u);
 320
 321         if (u->meta.type != _UNIT_TYPE_INVALID)
 322                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 323
 324         if (u->meta.in_load_queue)
 325                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 326
 327         if (u->meta.in_dbus_queue)
 328                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 329
 330         if (u->meta.in_cleanup_queue)
 331                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 332
 333         if (u->meta.in_gc_queue) {
 334                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 335                 u->meta.manager->n_in_gc_queue--;
 336         }
 337
 338         /* Free data and next 'smaller' objects */
 339         if (u->meta.job)
 340                 job_free(u->meta.job);
 341
 342         if (u->meta.load_state != UNIT_STUB)
 343                 if (UNIT_VTABLE(u)->done)
 344                         UNIT_VTABLE(u)->done(u);
 345
 346         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 347
 348         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 349                 bidi_set_free(u, u->meta.dependencies[d]);
 350
 351         free(u->meta.description);
 352         free(u->meta.fragment_path);
 353
 354         while ((t = set_steal_first(u->meta.names)))
 355                 free(t);
 356         set_free(u->meta.names);
 357
 358         free(u->meta.instance);
 359
 360         free(u);
 361 }
 362
 363 UnitActiveState unit_active_state(Unit *u) {
 364         assert(u);
 365
 366         if (u->meta.load_state != UNIT_LOADED)
 367                 return UNIT_INACTIVE;
 368
 369         return UNIT_VTABLE(u)->active_state(u);
 370 }
 371
 372 const char* unit_sub_state_to_string(Unit *u) {
 373         assert(u);
 374
 375         return UNIT_VTABLE(u)->sub_state_to_string(u);
 376 }
 377
 378 static void complete_move(Set **s, Set **other) {
 379         assert(s);
 380         assert(other);
 381
 382         if (!*other)
 383                 return;
 384
 385         if (*s)
 386                 set_move(*s, *other);
 387         else {
 388                 *s = *other;
 389                 *other = NULL;
 390         }
 391 }
 392
 393 static void merge_names(Unit *u, Unit *other) {
 394         char *t;
 395         Iterator i;
 396
 397         assert(u);
 398         assert(other);
 399
 400         complete_move(&u->meta.names, &other->meta.names);
 401
 402         while ((t = set_steal_first(other->meta.names)))
 403                 free(t);
 404
 405         set_free(other->meta.names);
 406         other->meta.names = NULL;
 407         other->meta.id = NULL;
 408
 409         SET_FOREACH(t, u->meta.names, i)
 410                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
 411 }
 412
 413 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
 414         Iterator i;
 415         Unit *back;
 416         int r;
 417
 418         assert(u);
 419         assert(other);
 420         assert(d < _UNIT_DEPENDENCY_MAX);
 421
 422         SET_FOREACH(back, other->meta.dependencies[d], i) {
 423                 UnitDependency k;
 424
 425                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
 426                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
 427
 428                                 if (r == -EEXIST)
 429                                         set_remove(back->meta.dependencies[k], other);
 430                                 else
 431                                         assert(r == -ENOENT);
 432                         }
 433         }
 434
 435         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
 436
 437         set_free(other->meta.dependencies[d]);
 438         other->meta.dependencies[d] = NULL;
 439 }
 440
 441 int unit_merge(Unit *u, Unit *other) {
 442         UnitDependency d;
 443
 444         assert(u);
 445         assert(other);
 446         assert(u->meta.manager == other->meta.manager);
 447         assert(u->meta.type != _UNIT_TYPE_INVALID);
 448
 449         other = unit_follow_merge(other);
 450
 451         if (other == u)
 452                 return 0;
 453
 454         if (u->meta.type != other->meta.type)
 455                 return -EINVAL;
 456
 457         if (!streq_ptr(u->meta.instance, other->meta.instance))
 458                 return -EINVAL;
 459
 460         if (other->meta.load_state != UNIT_STUB &&
 461             other->meta.load_state != UNIT_FAILED)
 462                 return -EEXIST;
 463
 464         if (other->meta.job)
 465                 return -EEXIST;
 466
 467         if (unit_active_state(other) != UNIT_INACTIVE)
 468                 return -EEXIST;
 469
 470         /* Merge names */
 471         merge_names(u, other);
 472
 473         /* Merge dependencies */
 474         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 475                 merge_dependencies(u, other, d);
 476
 477         other->meta.load_state = UNIT_MERGED;
 478         other->meta.merged_into = u;
 479
 480         /* If there is still some data attached to the other node, we
 481          * don't need it anymore, and can free it. */
 482         if (other->meta.load_state != UNIT_STUB)
 483                 if (UNIT_VTABLE(other)->done)
 484                         UNIT_VTABLE(other)->done(other);
 485
 486         unit_add_to_dbus_queue(u);
 487         unit_add_to_cleanup_queue(other);
 488
 489         return 0;
 490 }
 491
 492 int unit_merge_by_name(Unit *u, const char *name) {
 493         Unit *other;
 494         int r;
 495         char *s = NULL;
 496
 497         assert(u);
 498         assert(name);
 499
 500         if (unit_name_is_template(name)) {
 501                 if (!u->meta.instance)
 502                         return -EINVAL;
 503
 504                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
 505                         return -ENOMEM;
 506
 507                 name = s;
 508         }
 509
 510         if (!(other = manager_get_unit(u->meta.manager, name)))
 511                 r = unit_add_name(u, name);
 512         else
 513                 r = unit_merge(u, other);
 514
 515         free(s);
 516         return r;
 517 }
 518
 519 Unit* unit_follow_merge(Unit *u) {
 520         assert(u);
 521
 522         while (u->meta.load_state == UNIT_MERGED)
 523                 assert_se(u = u->meta.merged_into);
 524
 525         return u;
 526 }
 527
 528 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 529         int r;
 530
 531         assert(u);
 532         assert(c);
 533
 534         if (c->std_output != EXEC_OUTPUT_KERNEL && c->std_output != EXEC_OUTPUT_SYSLOG)
 535                 return 0;
 536
 537         /* If syslog or kernel logging is requested, make sure our own
 538          * logging daemon is run first. */
 539
 540         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 541                 return r;
 542
 543         if (u->meta.manager->running_as != MANAGER_SESSION)
 544                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 545                         return r;
 546
 547         return 0;
 548 }
 549
 550 const char *unit_description(Unit *u) {
 551         assert(u);
 552
 553         if (u->meta.description)
 554                 return u->meta.description;
 555
 556         return u->meta.id;
 557 }
 558
 559 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 560         char *t;
 561         UnitDependency d;
 562         Iterator i;
 563         char *p2;
 564         const char *prefix2;
 565         CGroupBonding *b;
 566         char
 567                 timestamp1[FORMAT_TIMESTAMP_MAX],
 568                 timestamp2[FORMAT_TIMESTAMP_MAX],
 569                 timestamp3[FORMAT_TIMESTAMP_MAX],
 570                 timestamp4[FORMAT_TIMESTAMP_MAX];
 571
 572         assert(u);
 573         assert(u->meta.type >= 0);
 574
 575         if (!prefix)
 576                 prefix = "";
 577         p2 = strappend(prefix, "\t");
 578         prefix2 = p2 ? p2 : prefix;
 579
 580         fprintf(f,
 581                 "%s-> Unit %s:\n"
 582                 "%s\tDescription: %s\n"
 583                 "%s\tInstance: %s\n"
 584                 "%s\tUnit Load State: %s\n"
 585                 "%s\tUnit Active State: %s\n"
 586                 "%s\tInactive Exit Timestamp: %s\n"
 587                 "%s\tActive Enter Timestamp: %s\n"
 588                 "%s\tActive Exit Timestamp: %s\n"
 589                 "%s\tInactive Enter Timestamp: %s\n"
 590                 "%s\tGC Check Good: %s\n",
 591                 prefix, u->meta.id,
 592                 prefix, unit_description(u),
 593                 prefix, strna(u->meta.instance),
 594                 prefix, unit_load_state_to_string(u->meta.load_state),
 595                 prefix, unit_active_state_to_string(unit_active_state(u)),
 596                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.inactive_exit_timestamp)),
 597                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_enter_timestamp)),
 598                 prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->meta.active_exit_timestamp)),
 599                 prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->meta.inactive_enter_timestamp)),
 600                 prefix, yes_no(unit_check_gc(u)));
 601
 602         SET_FOREACH(t, u->meta.names, i)
 603                 fprintf(f, "%s\tName: %s\n", prefix, t);
 604
 605         if (u->meta.fragment_path)
 606                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
 607
 608         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 609                 Unit *other;
 610
 611                 SET_FOREACH(other, u->meta.dependencies[d], i)
 612                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
 613         }
 614
 615         if (u->meta.load_state == UNIT_LOADED) {
 616                 fprintf(f,
 617                         "%s\tRecursive Stop: %s\n"
 618                         "%s\tStop When Unneeded: %s\n",
 619                         prefix, yes_no(u->meta.recursive_stop),
 620                         prefix, yes_no(u->meta.stop_when_unneeded));
 621
 622                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
 623                         fprintf(f, "%s\tControlGroup: %s:%s\n",
 624                                 prefix, b->controller, b->path);
 625
 626                 if (UNIT_VTABLE(u)->dump)
 627                         UNIT_VTABLE(u)->dump(u, f, prefix2);
 628
 629         } else if (u->meta.load_state == UNIT_MERGED)
 630                 fprintf(f,
 631                         "%s\tMerged into: %s\n",
 632                         prefix, u->meta.merged_into->meta.id);
 633
 634         if (u->meta.job)
 635                 job_dump(u->meta.job, f, prefix2);
 636
 637         free(p2);
 638 }
 639
 640 /* Common implementation for multiple backends */
 641 int unit_load_fragment_and_dropin(Unit *u) {
 642         int r;
 643
 644         assert(u);
 645
 646         /* Load a .service file */
 647         if ((r = unit_load_fragment(u)) < 0)
 648                 return r;
 649
 650         if (u->meta.load_state == UNIT_STUB)
 651                 return -ENOENT;
 652
 653         /* Load drop-in directory data */
 654         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 655                 return r;
 656
 657         return 0;
 658 }
 659
 660 /* Common implementation for multiple backends */
 661 int unit_load_fragment_and_dropin_optional(Unit *u) {
 662         int r;
 663
 664         assert(u);
 665
 666         /* Same as unit_load_fragment_and_dropin(), but whether
 667          * something can be loaded or not doesn't matter. */
 668
 669         /* Load a .service file */
 670         if ((r = unit_load_fragment(u)) < 0)
 671                 return r;
 672
 673         if (u->meta.load_state == UNIT_STUB)
 674                 u->meta.load_state = UNIT_LOADED;
 675
 676         /* Load drop-in directory data */
 677         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 678                 return r;
 679
 680         return 0;
 681 }
 682
 683 /* Common implementation for multiple backends */
 684 int unit_load_nop(Unit *u) {
 685         assert(u);
 686
 687         if (u->meta.load_state == UNIT_STUB)
 688                 u->meta.load_state = UNIT_LOADED;
 689
 690         return 0;
 691 }
 692
 693 int unit_load(Unit *u) {
 694         int r;
 695
 696         assert(u);
 697
 698         if (u->meta.in_load_queue) {
 699                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 700                 u->meta.in_load_queue = false;
 701         }
 702
 703         if (u->meta.type == _UNIT_TYPE_INVALID)
 704                 return -EINVAL;
 705
 706         if (u->meta.load_state != UNIT_STUB)
 707                 return 0;
 708
 709         if (UNIT_VTABLE(u)->load)
 710                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
 711                         goto fail;
 712
 713         if (u->meta.load_state == UNIT_STUB) {
 714                 r = -ENOENT;
 715                 goto fail;
 716         }
 717
 718         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
 719
 720         unit_add_to_dbus_queue(unit_follow_merge(u));
 721         unit_add_to_gc_queue(u);
 722
 723         return 0;
 724
 725 fail:
 726         u->meta.load_state = UNIT_FAILED;
 727         unit_add_to_dbus_queue(u);
 728
 729         log_debug("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
 730
 731         return r;
 732 }
 733
 734 /* Errors:
 735  *         -EBADR:    This unit type does not support starting.
 736  *         -EALREADY: Unit is already started.
 737  *         -EAGAIN:   An operation is already in progress. Retry later.
 738  */
 739 int unit_start(Unit *u) {
 740         UnitActiveState state;
 741
 742         assert(u);
 743
 744         /* If this is already (being) started, then this will
 745          * succeed. Note that this will even succeed if this unit is
 746          * not startable by the user. This is relied on to detect when
 747          * we need to wait for units and when waiting is finished. */
 748         state = unit_active_state(u);
 749         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 750                 return -EALREADY;
 751
 752         /* If it is stopped, but we cannot start it, then fail */
 753         if (!UNIT_VTABLE(u)->start)
 754                 return -EBADR;
 755
 756         /* We don't suppress calls to ->start() here when we are
 757          * already starting, to allow this request to be used as a
 758          * "hurry up" call, for example when the unit is in some "auto
 759          * restart" state where it waits for a holdoff timer to elapse
 760          * before it will start again. */
 761
 762         unit_add_to_dbus_queue(u);
 763         return UNIT_VTABLE(u)->start(u);
 764 }
 765
 766 bool unit_can_start(Unit *u) {
 767         assert(u);
 768
 769         return !!UNIT_VTABLE(u)->start;
 770 }
 771
 772 /* Errors:
 773  *         -EBADR:    This unit type does not support stopping.
 774  *         -EALREADY: Unit is already stopped.
 775  *         -EAGAIN:   An operation is already in progress. Retry later.
 776  */
 777 int unit_stop(Unit *u) {
 778         UnitActiveState state;
 779
 780         assert(u);
 781
 782         state = unit_active_state(u);
 783         if (state == UNIT_INACTIVE)
 784                 return -EALREADY;
 785
 786         if (!UNIT_VTABLE(u)->stop)
 787                 return -EBADR;
 788
 789         unit_add_to_dbus_queue(u);
 790         return UNIT_VTABLE(u)->stop(u);
 791 }
 792
 793 /* Errors:
 794  *         -EBADR:    This unit type does not support reloading.
 795  *         -ENOEXEC:  Unit is not started.
 796  *         -EAGAIN:   An operation is already in progress. Retry later.
 797  */
 798 int unit_reload(Unit *u) {
 799         UnitActiveState state;
 800
 801         assert(u);
 802
 803         if (!unit_can_reload(u))
 804                 return -EBADR;
 805
 806         state = unit_active_state(u);
 807         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 808                 return -EALREADY;
 809
 810         if (unit_active_state(u) != UNIT_ACTIVE)
 811                 return -ENOEXEC;
 812
 813         unit_add_to_dbus_queue(u);
 814         return UNIT_VTABLE(u)->reload(u);
 815 }
 816
 817 bool unit_can_reload(Unit *u) {
 818         assert(u);
 819
 820         if (!UNIT_VTABLE(u)->reload)
 821                 return false;
 822
 823         if (!UNIT_VTABLE(u)->can_reload)
 824                 return true;
 825
 826         return UNIT_VTABLE(u)->can_reload(u);
 827 }
 828
 829 static void unit_check_uneeded(Unit *u) {
 830         Iterator i;
 831         Unit *other;
 832
 833         assert(u);
 834
 835         /* If this service shall be shut down when unneeded then do
 836          * so. */
 837
 838         if (!u->meta.stop_when_unneeded)
 839                 return;
 840
 841         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 842                 return;
 843
 844         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 845                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 846                         return;
 847
 848         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 849                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 850                         return;
 851
 852         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 853                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 854                         return;
 855
 856         log_debug("Service %s is not needed anymore. Stopping.", u->meta.id);
 857
 858         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 859         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 860 }
 861
 862 static void retroactively_start_dependencies(Unit *u) {
 863         Iterator i;
 864         Unit *other;
 865
 866         assert(u);
 867         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 868
 869         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 870                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 871                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 872
 873         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 874                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 875                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 876
 877         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 878                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 879                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 880
 881         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 882                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 883                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 884
 885         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 886                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 887                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 888 }
 889
 890 static void retroactively_stop_dependencies(Unit *u) {
 891         Iterator i;
 892         Unit *other;
 893
 894         assert(u);
 895         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 896
 897         if (u->meta.recursive_stop) {
 898                 /* Pull down units need us recursively if enabled */
 899                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 900                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 901                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 902         }
 903
 904         /* Garbage collect services that might not be needed anymore, if enabled */
 905         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 906                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 907                         unit_check_uneeded(other);
 908         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 909                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 910                         unit_check_uneeded(other);
 911         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 912                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 913                         unit_check_uneeded(other);
 914         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], 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_REQUISITE_OVERRIDABLE], i)
 918                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 919                         unit_check_uneeded(other);
 920 }
 921
 922 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 923         bool unexpected = false;
 924         usec_t ts;
 925
 926         assert(u);
 927         assert(os < _UNIT_ACTIVE_STATE_MAX);
 928         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 929
 930         /* Note that this is called for all low-level state changes,
 931          * even if they might map to the same high-level
 932          * UnitActiveState! That means that ns == os is OK an expected
 933          * behaviour here. For example: if a mount point is remounted
 934          * this function will be called too and the utmp code below
 935          * relies on that! */
 936
 937         ts = now(CLOCK_REALTIME);
 938
 939         if (os == UNIT_INACTIVE && ns != UNIT_INACTIVE)
 940                 u->meta.inactive_exit_timestamp = ts;
 941         else if (os != UNIT_INACTIVE && ns == UNIT_INACTIVE)
 942                 u->meta.inactive_enter_timestamp = ts;
 943
 944         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 945                 u->meta.active_enter_timestamp = ts;
 946         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 947                 u->meta.active_exit_timestamp = ts;
 948
 949         if (u->meta.job) {
 950
 951                 if (u->meta.job->state == JOB_WAITING)
 952
 953                         /* So we reached a different state for this
 954                          * job. Let's see if we can run it now if it
 955                          * failed previously due to EAGAIN. */
 956                         job_add_to_run_queue(u->meta.job);
 957
 958                 else {
 959                         assert(u->meta.job->state == JOB_RUNNING);
 960
 961                         /* Let's check whether this state change
 962                          * constitutes a finished job, or maybe
 963                          * cotradicts a running job and hence needs to
 964                          * invalidate jobs. */
 965
 966                         switch (u->meta.job->type) {
 967
 968                         case JOB_START:
 969                         case JOB_VERIFY_ACTIVE:
 970
 971                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 972                                         job_finish_and_invalidate(u->meta.job, true);
 973                                 else if (ns != UNIT_ACTIVATING) {
 974                                         unexpected = true;
 975                                         job_finish_and_invalidate(u->meta.job, false);
 976                                 }
 977
 978                                 break;
 979
 980                         case JOB_RELOAD:
 981                         case JOB_RELOAD_OR_START:
 982
 983                                 if (ns == UNIT_ACTIVE)
 984                                         job_finish_and_invalidate(u->meta.job, true);
 985                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_ACTIVE_RELOADING) {
 986                                         unexpected = true;
 987                                         job_finish_and_invalidate(u->meta.job, false);
 988                                 }
 989
 990                                 break;
 991
 992                         case JOB_STOP:
 993                         case JOB_RESTART:
 994                         case JOB_TRY_RESTART:
 995
 996                                 if (ns == UNIT_INACTIVE)
 997                                         job_finish_and_invalidate(u->meta.job, true);
 998                                 else if (ns != UNIT_DEACTIVATING) {
 999                                         unexpected = true;
1000                                         job_finish_and_invalidate(u->meta.job, false);
1001                                 }
1002
1003                                 break;
1004
1005                         default:
1006                                 assert_not_reached("Job type unknown");
1007                         }
1008                 }
1009         }
1010
1011         /* If this state change happened without being requested by a
1012          * job, then let's retroactively start or stop dependencies */
1013
1014         if (unexpected) {
1015                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1016                         retroactively_start_dependencies(u);
1017                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1018                         retroactively_stop_dependencies(u);
1019         }
1020
1021         /* Some names are special */
1022         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1023                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1024                         /* The bus just might have become available,
1025                          * hence try to connect to it, if we aren't
1026                          * yet connected. */
1027                         bus_init_system(u->meta.manager);
1028                         bus_init_api(u->meta.manager);
1029                 }
1030
1031                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1032                         /* The syslog daemon just might have become
1033                          * available, hence try to connect to it, if
1034                          * we aren't yet connected. */
1035                         log_open();
1036
1037                 if (u->meta.type == UNIT_MOUNT)
1038                         /* Another directory became available, let's
1039                          * check if that is enough to write our utmp
1040                          * entry. */
1041                         manager_write_utmp_reboot(u->meta.manager);
1042
1043                 if (u->meta.type == UNIT_TARGET)
1044                         /* A target got activated, maybe this is a runlevel? */
1045                         manager_write_utmp_runlevel(u->meta.manager, u);
1046
1047         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1048
1049                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1050                         /* The syslog daemon might just have
1051                          * terminated, hence try to disconnect from
1052                          * it. */
1053                         log_close_syslog();
1054
1055                 /* We don't care about D-Bus here, since we'll get an
1056                  * asynchronous notification for it anyway. */
1057         }
1058
1059         /* Maybe we finished startup and are now ready for being
1060          * stopped because unneeded? */
1061         unit_check_uneeded(u);
1062
1063         unit_add_to_dbus_queue(u);
1064         unit_add_to_gc_queue(u);
1065 }
1066
1067 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1068         struct epoll_event ev;
1069
1070         assert(u);
1071         assert(fd >= 0);
1072         assert(w);
1073         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1074
1075         zero(ev);
1076         ev.data.ptr = w;
1077         ev.events = events;
1078
1079         if (epoll_ctl(u->meta.manager->epoll_fd,
1080                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1081                       fd,
1082                       &ev) < 0)
1083                 return -errno;
1084
1085         w->fd = fd;
1086         w->type = WATCH_FD;
1087         w->data.unit = u;
1088
1089         return 0;
1090 }
1091
1092 void unit_unwatch_fd(Unit *u, Watch *w) {
1093         assert(u);
1094         assert(w);
1095
1096         if (w->type == WATCH_INVALID)
1097                 return;
1098
1099         assert(w->type == WATCH_FD);
1100         assert(w->data.unit == u);
1101         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1102
1103         w->fd = -1;
1104         w->type = WATCH_INVALID;
1105         w->data.unit = NULL;
1106 }
1107
1108 int unit_watch_pid(Unit *u, pid_t pid) {
1109         assert(u);
1110         assert(pid >= 1);
1111
1112         /* Watch a specific PID. We only support one unit watching
1113          * each PID for now. */
1114
1115         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1116 }
1117
1118 void unit_unwatch_pid(Unit *u, pid_t pid) {
1119         assert(u);
1120         assert(pid >= 1);
1121
1122         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1123 }
1124
1125 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1126         struct itimerspec its;
1127         int flags, fd;
1128         bool ours;
1129
1130         assert(u);
1131         assert(w);
1132         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1133
1134         /* This will try to reuse the old timer if there is one */
1135
1136         if (w->type == WATCH_TIMER) {
1137                 ours = false;
1138                 fd = w->fd;
1139         } else {
1140                 ours = true;
1141                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1142                         return -errno;
1143         }
1144
1145         zero(its);
1146
1147         if (delay <= 0) {
1148                 /* Set absolute time in the past, but not 0, since we
1149                  * don't want to disarm the timer */
1150                 its.it_value.tv_sec = 0;
1151                 its.it_value.tv_nsec = 1;
1152
1153                 flags = TFD_TIMER_ABSTIME;
1154         } else {
1155                 timespec_store(&its.it_value, delay);
1156                 flags = 0;
1157         }
1158
1159         /* This will also flush the elapse counter */
1160         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1161                 goto fail;
1162
1163         if (w->type == WATCH_INVALID) {
1164                 struct epoll_event ev;
1165
1166                 zero(ev);
1167                 ev.data.ptr = w;
1168                 ev.events = EPOLLIN;
1169
1170                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1171                         goto fail;
1172         }
1173
1174         w->fd = fd;
1175         w->type = WATCH_TIMER;
1176         w->data.unit = u;
1177
1178         return 0;
1179
1180 fail:
1181         if (ours)
1182                 close_nointr_nofail(fd);
1183
1184         return -errno;
1185 }
1186
1187 void unit_unwatch_timer(Unit *u, Watch *w) {
1188         assert(u);
1189         assert(w);
1190
1191         if (w->type == WATCH_INVALID)
1192                 return;
1193
1194         assert(w->type == WATCH_TIMER && w->data.unit == u);
1195
1196         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1197         close_nointr_nofail(w->fd);
1198
1199         w->fd = -1;
1200         w->type = WATCH_INVALID;
1201         w->data.unit = NULL;
1202 }
1203
1204 bool unit_job_is_applicable(Unit *u, JobType j) {
1205         assert(u);
1206         assert(j >= 0 && j < _JOB_TYPE_MAX);
1207
1208         switch (j) {
1209
1210         case JOB_VERIFY_ACTIVE:
1211         case JOB_START:
1212                 return true;
1213
1214         case JOB_STOP:
1215         case JOB_RESTART:
1216         case JOB_TRY_RESTART:
1217                 return unit_can_start(u);
1218
1219         case JOB_RELOAD:
1220                 return unit_can_reload(u);
1221
1222         case JOB_RELOAD_OR_START:
1223                 return unit_can_reload(u) && unit_can_start(u);
1224
1225         default:
1226                 assert_not_reached("Invalid job type");
1227         }
1228 }
1229
1230 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1231
1232         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1233                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1234                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1235                 [UNIT_WANTS] = UNIT_WANTED_BY,
1236                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1237                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1238                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1239                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1240                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1241                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1242                 [UNIT_BEFORE] = UNIT_AFTER,
1243                 [UNIT_AFTER] = UNIT_BEFORE,
1244                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1245                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1246         };
1247         int r, q = 0, v = 0, w = 0;
1248
1249         assert(u);
1250         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1251         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1252         assert(other);
1253
1254         /* We won't allow dependencies on ourselves. We will not
1255          * consider them an error however. */
1256         if (u == other)
1257                 return 0;
1258
1259         if (UNIT_VTABLE(u)->no_requires &&
1260             (d == UNIT_REQUIRES ||
1261              d == UNIT_REQUIRES_OVERRIDABLE ||
1262              d == UNIT_REQUISITE ||
1263              d == UNIT_REQUISITE_OVERRIDABLE)) {
1264                     return -EINVAL;
1265         }
1266
1267         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1268             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1269                 return r;
1270
1271         if (add_reference)
1272                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1273                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1274                         return r;
1275
1276         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1277                 return q;
1278
1279         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1280                 r = v;
1281                 goto fail;
1282         }
1283
1284         if (add_reference) {
1285                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1286                         r = w;
1287                         goto fail;
1288                 }
1289
1290                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1291                         goto fail;
1292         }
1293
1294         unit_add_to_dbus_queue(u);
1295         return 0;
1296
1297 fail:
1298         if (q > 0)
1299                 set_remove(u->meta.dependencies[d], other);
1300
1301         if (v > 0)
1302                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1303
1304         if (w > 0)
1305                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1306
1307         return r;
1308 }
1309
1310 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1311         char *s;
1312
1313         assert(u);
1314         assert(name || path);
1315
1316         if (!name)
1317                 name = file_name_from_path(path);
1318
1319         if (!unit_name_is_template(name)) {
1320                 *p = NULL;
1321                 return name;
1322         }
1323
1324         if (u->meta.instance)
1325                 s = unit_name_replace_instance(name, u->meta.instance);
1326         else {
1327                 char *i;
1328
1329                 if (!(i = unit_name_to_prefix(u->meta.id)))
1330                         return NULL;
1331
1332                 s = unit_name_replace_instance(name, i);
1333                 free(i);
1334         }
1335
1336         if (!s)
1337                 return NULL;
1338
1339         *p = s;
1340         return s;
1341 }
1342
1343 int unit_add_dependency_by_name(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(u, d, other, add_reference);
1358
1359 finish:
1360         free(s);
1361         return r;
1362 }
1363
1364 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1365         Unit *other;
1366         int r;
1367         char *s;
1368
1369         assert(u);
1370         assert(name || path);
1371
1372         if (!(name = resolve_template(u, name, path, &s)))
1373                 return -ENOMEM;
1374
1375         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1376                 goto finish;
1377
1378         r = unit_add_dependency(other, d, u, add_reference);
1379
1380 finish:
1381         free(s);
1382         return r;
1383 }
1384
1385 int set_unit_path(const char *p) {
1386         char *cwd, *c;
1387         int r;
1388
1389         /* This is mostly for debug purposes */
1390
1391         if (path_is_absolute(p)) {
1392                 if (!(c = strdup(p)))
1393                         return -ENOMEM;
1394         } else {
1395                 if (!(cwd = get_current_dir_name()))
1396                         return -errno;
1397
1398                 r = asprintf(&c, "%s/%s", cwd, p);
1399                 free(cwd);
1400
1401                 if (r < 0)
1402                         return -ENOMEM;
1403         }
1404
1405         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1406                 r = -errno;
1407                 free(c);
1408                 return r;
1409         }
1410
1411         return 0;
1412 }
1413
1414 char *unit_dbus_path(Unit *u) {
1415         char *p, *e;
1416
1417         assert(u);
1418
1419         if (!(e = bus_path_escape(u->meta.id)))
1420                 return NULL;
1421
1422         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1423                 free(e);
1424                 return NULL;
1425         }
1426
1427         free(e);
1428         return p;
1429 }
1430
1431 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1432         CGroupBonding *l;
1433         int r;
1434
1435         assert(u);
1436         assert(b);
1437         assert(b->path);
1438
1439         /* Ensure this hasn't been added yet */
1440         assert(!b->unit);
1441
1442         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1443         LIST_PREPEND(CGroupBonding, by_path, l, b);
1444
1445         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1446                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1447                 return r;
1448         }
1449
1450         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1451         b->unit = u;
1452
1453         return 0;
1454 }
1455
1456 static char *default_cgroup_path(Unit *u) {
1457         char *p;
1458         int r;
1459
1460         assert(u);
1461
1462         if (u->meta.instance) {
1463                 char *t;
1464
1465                 if (!(t = unit_name_template(u->meta.id)))
1466                         return NULL;
1467
1468                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1469                 free(t);
1470         } else
1471                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1472
1473         return r < 0 ? NULL : p;
1474 }
1475
1476 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1477         size_t n;
1478         char *controller = NULL, *path = NULL;
1479         CGroupBonding *b = NULL;
1480         int r;
1481
1482         assert(u);
1483         assert(name);
1484
1485         /* Detect controller name */
1486         n = strcspn(name, ":");
1487
1488         if (name[n] == 0 ||
1489             (name[n] == ':' && name[n+1] == 0)) {
1490
1491                 /* Only controller name, no path? */
1492
1493                 if (!(path = default_cgroup_path(u)))
1494                         return -ENOMEM;
1495
1496         } else {
1497                 const char *p;
1498
1499                 /* Controller name, and path. */
1500                 p = name+n+1;
1501
1502                 if (!path_is_absolute(p))
1503                         return -EINVAL;
1504
1505                 if (!(path = strdup(p)))
1506                         return -ENOMEM;
1507         }
1508
1509         if (n > 0)
1510                 controller = strndup(name, n);
1511         else
1512                 controller = strdup(u->meta.manager->cgroup_controller);
1513
1514         if (!controller) {
1515                 r = -ENOMEM;
1516                 goto fail;
1517         }
1518
1519         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1520                 r = -EEXIST;
1521                 goto fail;
1522         }
1523
1524         if (!(b = new0(CGroupBonding, 1))) {
1525                 r = -ENOMEM;
1526                 goto fail;
1527         }
1528
1529         b->controller = controller;
1530         b->path = path;
1531         b->only_us = false;
1532         b->clean_up = false;
1533
1534         if ((r = unit_add_cgroup(u, b)) < 0)
1535                 goto fail;
1536
1537         return 0;
1538
1539 fail:
1540         free(path);
1541         free(controller);
1542         free(b);
1543
1544         return r;
1545 }
1546
1547 int unit_add_default_cgroup(Unit *u) {
1548         CGroupBonding *b;
1549         int r = -ENOMEM;
1550
1551         assert(u);
1552
1553         /* Adds in the default cgroup data, if it wasn't specified yet */
1554
1555         if (unit_get_default_cgroup(u))
1556                 return 0;
1557
1558         if (!(b = new0(CGroupBonding, 1)))
1559                 return -ENOMEM;
1560
1561         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1562                 goto fail;
1563
1564         if (!(b->path = default_cgroup_path(u)))
1565                 goto fail;
1566
1567         b->clean_up = true;
1568         b->only_us = true;
1569
1570         if ((r = unit_add_cgroup(u, b)) < 0)
1571                 goto fail;
1572
1573         return 0;
1574
1575 fail:
1576         free(b->path);
1577         free(b->controller);
1578         free(b);
1579
1580         return r;
1581 }
1582
1583 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1584         assert(u);
1585
1586         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1587 }
1588
1589 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1590         char *t;
1591         int r;
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         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1603         free(t);
1604
1605         assert(r < 0 || *_found != u);
1606
1607         return r;
1608 }
1609
1610 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1611         Unit *found;
1612         char *t;
1613
1614         assert(u);
1615         assert(type);
1616         assert(_found);
1617
1618         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1619                 return -ENOMEM;
1620
1621         assert(!unit_has_name(u, t));
1622
1623         found = manager_get_unit(u->meta.manager, t);
1624         free(t);
1625
1626         if (!found)
1627                 return -ENOENT;
1628
1629         *_found = found;
1630         return 0;
1631 }
1632
1633 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1634         Unit *u = userdata;
1635         assert(u);
1636
1637         return unit_name_to_prefix_and_instance(u->meta.id);
1638 }
1639
1640 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1641         Unit *u = userdata;
1642         assert(u);
1643
1644         return unit_name_to_prefix(u->meta.id);
1645 }
1646
1647 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1648         Unit *u = userdata;
1649         char *p, *r;
1650
1651         assert(u);
1652
1653         if (!(p = unit_name_to_prefix(u->meta.id)))
1654                 return NULL;
1655
1656         r = unit_name_unescape(p);
1657         free(p);
1658
1659         return r;
1660 }
1661
1662 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1663         Unit *u = userdata;
1664         assert(u);
1665
1666         if (u->meta.instance)
1667                 return unit_name_unescape(u->meta.instance);
1668
1669         return strdup("");
1670 }
1671
1672 char *unit_name_printf(Unit *u, const char* format) {
1673
1674         /*
1675          * This will use the passed string as format string and
1676          * replace the following specifiers:
1677          *
1678          * %n: the full id of the unit                 (foo@bar.waldo)
1679          * %N: the id of the unit without the suffix   (foo@bar)
1680          * %p: the prefix                              (foo)
1681          * %i: the instance                            (bar)
1682          */
1683
1684         const Specifier table[] = {
1685                 { 'n', specifier_string,              u->meta.id },
1686                 { 'N', specifier_prefix_and_instance, NULL },
1687                 { 'p', specifier_prefix,              NULL },
1688                 { 'i', specifier_string,              u->meta.instance },
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(Unit *u, const char *format) {
1699
1700         /* This is similar to unit_name_printf() but also supports
1701          * unescaping */
1702
1703         const Specifier table[] = {
1704                 { 'n', specifier_string,              u->meta.id },
1705                 { 'N', specifier_prefix_and_instance, NULL },
1706                 { 'p', specifier_prefix,              NULL },
1707                 { 'P', specifier_prefix_unescaped,    NULL },
1708                 { 'i', specifier_string,              u->meta.instance },
1709                 { 'I', specifier_instance_unescaped,  NULL },
1710                 { 0, NULL, NULL }
1711         };
1712
1713         assert(u);
1714         assert(format);
1715
1716         return specifier_printf(format, table, u);
1717 }
1718
1719 char **unit_full_printf_strv(Unit *u, char **l) {
1720         size_t n;
1721         char **r, **i, **j;
1722
1723         /* Applies unit_full_printf to every entry in l */
1724
1725         assert(u);
1726
1727         n = strv_length(l);
1728         if (!(r = new(char*, n+1)))
1729                 return NULL;
1730
1731         for (i = l, j = r; *i; i++, j++)
1732                 if (!(*j = unit_full_printf(u, *i)))
1733                         goto fail;
1734
1735         *j = NULL;
1736         return r;
1737
1738 fail:
1739         j--;
1740         while (j >= r)
1741                 free(*j);
1742
1743         free(r);
1744
1745         return NULL;
1746 }
1747
1748 int unit_watch_bus_name(Unit *u, const char *name) {
1749         assert(u);
1750         assert(name);
1751
1752         /* Watch a specific name on the bus. We only support one unit
1753          * watching each name for now. */
1754
1755         return hashmap_put(u->meta.manager->watch_bus, name, u);
1756 }
1757
1758 void unit_unwatch_bus_name(Unit *u, const char *name) {
1759         assert(u);
1760         assert(name);
1761
1762         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1763 }
1764
1765 bool unit_can_serialize(Unit *u) {
1766         assert(u);
1767
1768         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1769 }
1770
1771 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1772         int r;
1773
1774         assert(u);
1775         assert(f);
1776         assert(fds);
1777
1778         if (!unit_can_serialize(u))
1779                 return 0;
1780
1781         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1782                 return r;
1783
1784         /* End marker */
1785         fputc('\n', f);
1786         return 0;
1787 }
1788
1789 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1790         va_list ap;
1791
1792         assert(u);
1793         assert(f);
1794         assert(key);
1795         assert(format);
1796
1797         fputs(key, f);
1798         fputc('=', f);
1799
1800         va_start(ap, format);
1801         vfprintf(f, format, ap);
1802         va_end(ap);
1803
1804         fputc('\n', f);
1805 }
1806
1807 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1808         assert(u);
1809         assert(f);
1810         assert(key);
1811         assert(value);
1812
1813         fprintf(f, "%s=%s\n", key, value);
1814 }
1815
1816 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1817         int r;
1818
1819         assert(u);
1820         assert(f);
1821         assert(fds);
1822
1823         if (!unit_can_serialize(u))
1824                 return 0;
1825
1826         for (;;) {
1827                 char line[1024], *l, *v;
1828                 size_t k;
1829
1830                 if (!fgets(line, sizeof(line), f)) {
1831                         if (feof(f))
1832                                 return 0;
1833                         return -errno;
1834                 }
1835
1836                 l = strstrip(line);
1837
1838                 /* End marker */
1839                 if (l[0] == 0)
1840                         return 0;
1841
1842                 k = strcspn(l, "=");
1843
1844                 if (l[k] == '=') {
1845                         l[k] = 0;
1846                         v = l+k+1;
1847                 } else
1848                         v = l+k;
1849
1850                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1851                         return r;
1852         }
1853 }
1854
1855 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1856         Unit *device;
1857         char *e;
1858         int r;
1859
1860         assert(u);
1861
1862         if (!what)
1863                 return 0;
1864
1865         /* Adds in links to the device node that this unit is based on */
1866
1867         if (!is_device_path(what))
1868                 return 0;
1869
1870         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
1871                 return -ENOMEM;
1872
1873         r = manager_load_unit(u->meta.manager, e, NULL, &device);
1874         free(e);
1875
1876         if (r < 0)
1877                 return r;
1878
1879         if ((r = unit_add_dependency(u, UNIT_AFTER, device, true)) < 0)
1880                 return r;
1881
1882         if ((r = unit_add_dependency(u, UNIT_REQUIRES, device, true)) < 0)
1883                 return r;
1884
1885         if (wants)
1886                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
1887                         return r;
1888
1889         return 0;
1890 }
1891
1892 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1893         [UNIT_SERVICE] = "service",
1894         [UNIT_TIMER] = "timer",
1895         [UNIT_SOCKET] = "socket",
1896         [UNIT_TARGET] = "target",
1897         [UNIT_DEVICE] = "device",
1898         [UNIT_MOUNT] = "mount",
1899         [UNIT_AUTOMOUNT] = "automount",
1900         [UNIT_SNAPSHOT] = "snapshot",
1901         [UNIT_SWAP] = "swap"
1902 };
1903
1904 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1905
1906 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1907         [UNIT_STUB] = "stub",
1908         [UNIT_LOADED] = "loaded",
1909         [UNIT_FAILED] = "failed",
1910         [UNIT_MERGED] = "merged"
1911 };
1912
1913 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1914
1915 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1916         [UNIT_ACTIVE] = "active",
1917         [UNIT_INACTIVE] = "inactive",
1918         [UNIT_ACTIVATING] = "activating",
1919         [UNIT_DEACTIVATING] = "deactivating"
1920 };
1921
1922 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1923
1924 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1925         [UNIT_REQUIRES] = "Requires",
1926         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
1927         [UNIT_WANTS] = "Wants",
1928         [UNIT_REQUISITE] = "Requisite",
1929         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
1930         [UNIT_REQUIRED_BY] = "RequiredBy",
1931         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
1932         [UNIT_WANTED_BY] = "WantedBy",
1933         [UNIT_CONFLICTS] = "Conflicts",
1934         [UNIT_BEFORE] = "Before",
1935         [UNIT_AFTER] = "After",
1936         [UNIT_REFERENCES] = "References",
1937         [UNIT_REFERENCED_BY] = "ReferencedBy"
1938 };
1939
1940 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
1941
1942 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1943         [KILL_CONTROL_GROUP] = "control-group",
1944         [KILL_PROCESS_GROUP] = "process-group",
1945         [KILL_PROCESS] = "process",
1946         [KILL_NONE] = "none"
1947 };
1948
1949 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);