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 };
  52
  53 Unit *unit_new(Manager *m) {
  54         Unit *u;
  55
  56         assert(m);
  57
  58         if (!(u = new0(Unit, 1)))
  59                 return NULL;
  60
  61         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
  62                 free(u);
  63                 return NULL;
  64         }
  65
  66         u->meta.manager = m;
  67         u->meta.type = _UNIT_TYPE_INVALID;
  68
  69         return u;
  70 }
  71
  72 bool unit_has_name(Unit *u, const char *name) {
  73         assert(u);
  74         assert(name);
  75
  76         return !!set_get(u->meta.names, (char*) name);
  77 }
  78
  79 int unit_add_name(Unit *u, const char *text) {
  80         UnitType t;
  81         char *s = NULL, *i = NULL;
  82         int r;
  83
  84         assert(u);
  85         assert(text);
  86
  87         if (unit_name_is_template(text)) {
  88                 if (!u->meta.instance)
  89                         return -EINVAL;
  90
  91                 s = unit_name_replace_instance(text, u->meta.instance);
  92         } else
  93                 s = strdup(text);
  94
  95         if (!s)
  96                 return -ENOMEM;
  97
  98         if (!unit_name_is_valid(s)) {
  99                 r = -EINVAL;
 100                 goto fail;
 101         }
 102
 103         assert_se((t = unit_name_to_type(s)) >= 0);
 104
 105         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
 106                 r = -EINVAL;
 107                 goto fail;
 108         }
 109
 110         if ((r = unit_name_to_instance(s, &i)) < 0)
 111                 goto fail;
 112
 113         if (i && unit_vtable[t]->no_instances)
 114                 goto fail;
 115
 116         if (u->meta.type != _UNIT_TYPE_INVALID && !streq_ptr(u->meta.instance, i)) {
 117                 r = -EINVAL;
 118                 goto fail;
 119         }
 120
 121         if (unit_vtable[t]->no_alias &&
 122             !set_isempty(u->meta.names) &&
 123             !set_get(u->meta.names, s)) {
 124                 r = -EEXIST;
 125                 goto fail;
 126         }
 127
 128         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
 129                 r = -E2BIG;
 130                 goto fail;
 131         }
 132
 133         if ((r = set_put(u->meta.names, s)) < 0) {
 134                 if (r == -EEXIST)
 135                         r = 0;
 136                 goto fail;
 137         }
 138
 139         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 140                 set_remove(u->meta.names, s);
 141                 goto fail;
 142         }
 143
 144         if (u->meta.type == _UNIT_TYPE_INVALID) {
 145
 146                 u->meta.type = t;
 147                 u->meta.id = s;
 148                 u->meta.instance = i;
 149
 150                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 151
 152                 if (UNIT_VTABLE(u)->init)
 153                         UNIT_VTABLE(u)->init(u);
 154         } else
 155                 free(i);
 156
 157         unit_add_to_dbus_queue(u);
 158         return 0;
 159
 160 fail:
 161         free(s);
 162         free(i);
 163
 164         return r;
 165 }
 166
 167 int unit_choose_id(Unit *u, const char *name) {
 168         char *s, *t = NULL;
 169
 170         assert(u);
 171         assert(name);
 172
 173         if (unit_name_is_template(name)) {
 174
 175                 if (!u->meta.instance)
 176                         return -EINVAL;
 177
 178                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
 179                         return -ENOMEM;
 180
 181                 name = t;
 182         }
 183
 184         /* Selects one of the names of this unit as the id */
 185         s = set_get(u->meta.names, (char*) name);
 186         free(t);
 187
 188         if (!s)
 189                 return -ENOENT;
 190
 191         u->meta.id = s;
 192         unit_add_to_dbus_queue(u);
 193
 194         return 0;
 195 }
 196
 197 int unit_set_description(Unit *u, const char *description) {
 198         char *s;
 199
 200         assert(u);
 201
 202         if (!(s = strdup(description)))
 203                 return -ENOMEM;
 204
 205         free(u->meta.description);
 206         u->meta.description = s;
 207
 208         unit_add_to_dbus_queue(u);
 209         return 0;
 210 }
 211
 212 bool unit_check_gc(Unit *u) {
 213         assert(u);
 214
 215         if (UNIT_VTABLE(u)->no_gc)
 216                 return true;
 217
 218         if (u->meta.job)
 219                 return true;
 220
 221         if (unit_active_state(u) != UNIT_INACTIVE)
 222                 return true;
 223
 224         if (UNIT_VTABLE(u)->check_gc)
 225                 if (UNIT_VTABLE(u)->check_gc(u))
 226                         return true;
 227
 228         return false;
 229 }
 230
 231 void unit_add_to_load_queue(Unit *u) {
 232         assert(u);
 233         assert(u->meta.type != _UNIT_TYPE_INVALID);
 234
 235         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 236                 return;
 237
 238         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 239         u->meta.in_load_queue = true;
 240 }
 241
 242 void unit_add_to_cleanup_queue(Unit *u) {
 243         assert(u);
 244
 245         if (u->meta.in_cleanup_queue)
 246                 return;
 247
 248         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 249         u->meta.in_cleanup_queue = true;
 250 }
 251
 252 void unit_add_to_gc_queue(Unit *u) {
 253         assert(u);
 254
 255         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
 256                 return;
 257
 258         if (unit_check_gc(u))
 259                 return;
 260
 261         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 262         u->meta.in_gc_queue = true;
 263
 264         u->meta.manager->n_in_gc_queue ++;
 265
 266         if (u->meta.manager->gc_queue_timestamp <= 0)
 267                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
 268 }
 269
 270 void unit_add_to_dbus_queue(Unit *u) {
 271         assert(u);
 272         assert(u->meta.type != _UNIT_TYPE_INVALID);
 273
 274         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue || set_isempty(u->meta.manager->subscribed))
 275                 return;
 276
 277         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 278         u->meta.in_dbus_queue = true;
 279 }
 280
 281 static void bidi_set_free(Unit *u, Set *s) {
 282         Iterator i;
 283         Unit *other;
 284
 285         assert(u);
 286
 287         /* Frees the set and makes sure we are dropped from the
 288          * inverse pointers */
 289
 290         SET_FOREACH(other, s, i) {
 291                 UnitDependency d;
 292
 293                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 294                         set_remove(other->meta.dependencies[d], u);
 295
 296                 unit_add_to_gc_queue(other);
 297         }
 298
 299         set_free(s);
 300 }
 301
 302 void unit_free(Unit *u) {
 303         UnitDependency d;
 304         Iterator i;
 305         char *t;
 306
 307         assert(u);
 308
 309         bus_unit_send_removed_signal(u);
 310
 311         /* Detach from next 'bigger' objects */
 312         SET_FOREACH(t, u->meta.names, i)
 313                 hashmap_remove_value(u->meta.manager->units, t, u);
 314
 315         if (u->meta.type != _UNIT_TYPE_INVALID)
 316                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 317
 318         if (u->meta.in_load_queue)
 319                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 320
 321         if (u->meta.in_dbus_queue)
 322                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 323
 324         if (u->meta.in_cleanup_queue)
 325                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
 326
 327         if (u->meta.in_gc_queue) {
 328                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
 329                 u->meta.manager->n_in_gc_queue--;
 330         }
 331
 332         /* Free data and next 'smaller' objects */
 333         if (u->meta.job)
 334                 job_free(u->meta.job);
 335
 336         if (u->meta.load_state != UNIT_STUB)
 337                 if (UNIT_VTABLE(u)->done)
 338                         UNIT_VTABLE(u)->done(u);
 339
 340         cgroup_bonding_free_list(u->meta.cgroup_bondings);
 341
 342         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 343                 bidi_set_free(u, u->meta.dependencies[d]);
 344
 345         free(u->meta.description);
 346         free(u->meta.fragment_path);
 347
 348         while ((t = set_steal_first(u->meta.names)))
 349                 free(t);
 350         set_free(u->meta.names);
 351
 352         free(u->meta.instance);
 353
 354         free(u);
 355 }
 356
 357 UnitActiveState unit_active_state(Unit *u) {
 358         assert(u);
 359
 360         if (u->meta.load_state != UNIT_LOADED)
 361                 return UNIT_INACTIVE;
 362
 363         return UNIT_VTABLE(u)->active_state(u);
 364 }
 365
 366 const char* unit_sub_state_to_string(Unit *u) {
 367         assert(u);
 368
 369         return UNIT_VTABLE(u)->sub_state_to_string(u);
 370 }
 371
 372 static void complete_move(Set **s, Set **other) {
 373         assert(s);
 374         assert(other);
 375
 376         if (!*other)
 377                 return;
 378
 379         if (*s)
 380                 set_move(*s, *other);
 381         else {
 382                 *s = *other;
 383                 *other = NULL;
 384         }
 385 }
 386
 387 static void merge_names(Unit *u, Unit *other) {
 388         char *t;
 389         Iterator i;
 390
 391         assert(u);
 392         assert(other);
 393
 394         complete_move(&u->meta.names, &other->meta.names);
 395
 396         while ((t = set_steal_first(other->meta.names)))
 397                 free(t);
 398
 399         set_free(other->meta.names);
 400         other->meta.names = NULL;
 401         other->meta.id = NULL;
 402
 403         SET_FOREACH(t, u->meta.names, i)
 404                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
 405 }
 406
 407 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
 408         Iterator i;
 409         Unit *back;
 410         int r;
 411
 412         assert(u);
 413         assert(other);
 414         assert(d < _UNIT_DEPENDENCY_MAX);
 415
 416         SET_FOREACH(back, other->meta.dependencies[d], i) {
 417                 UnitDependency k;
 418
 419                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
 420                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
 421
 422                                 if (r == -EEXIST)
 423                                         set_remove(back->meta.dependencies[k], other);
 424                                 else
 425                                         assert(r == -ENOENT);
 426                         }
 427         }
 428
 429         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
 430
 431         set_free(other->meta.dependencies[d]);
 432         other->meta.dependencies[d] = NULL;
 433 }
 434
 435 int unit_merge(Unit *u, Unit *other) {
 436         UnitDependency d;
 437
 438         assert(u);
 439         assert(other);
 440         assert(u->meta.manager == other->meta.manager);
 441         assert(u->meta.type != _UNIT_TYPE_INVALID);
 442
 443         other = unit_follow_merge(other);
 444
 445         if (other == u)
 446                 return 0;
 447
 448         if (u->meta.type != other->meta.type)
 449                 return -EINVAL;
 450
 451         if (!streq_ptr(u->meta.instance, other->meta.instance))
 452                 return -EINVAL;
 453
 454         if (other->meta.load_state != UNIT_STUB &&
 455             other->meta.load_state != UNIT_FAILED)
 456                 return -EEXIST;
 457
 458         if (other->meta.job)
 459                 return -EEXIST;
 460
 461         if (unit_active_state(other) != UNIT_INACTIVE)
 462                 return -EEXIST;
 463
 464         /* Merge names */
 465         merge_names(u, other);
 466
 467         /* Merge dependencies */
 468         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 469                 merge_dependencies(u, other, d);
 470
 471         other->meta.load_state = UNIT_MERGED;
 472         other->meta.merged_into = u;
 473
 474         /* If there is still some data attached to the other node, we
 475          * don't need it anymore, and can free it. */
 476         if (other->meta.load_state != UNIT_STUB)
 477                 if (UNIT_VTABLE(other)->done)
 478                         UNIT_VTABLE(other)->done(other);
 479
 480         unit_add_to_dbus_queue(u);
 481         unit_add_to_cleanup_queue(other);
 482
 483         return 0;
 484 }
 485
 486 int unit_merge_by_name(Unit *u, const char *name) {
 487         Unit *other;
 488         int r;
 489         char *s = NULL;
 490
 491         assert(u);
 492         assert(name);
 493
 494         if (unit_name_is_template(name)) {
 495                 if (!u->meta.instance)
 496                         return -EINVAL;
 497
 498                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
 499                         return -ENOMEM;
 500
 501                 name = s;
 502         }
 503
 504         if (!(other = manager_get_unit(u->meta.manager, name)))
 505                 r = unit_add_name(u, name);
 506         else
 507                 r = unit_merge(u, other);
 508
 509         free(s);
 510         return r;
 511 }
 512
 513 Unit* unit_follow_merge(Unit *u) {
 514         assert(u);
 515
 516         while (u->meta.load_state == UNIT_MERGED)
 517                 assert_se(u = u->meta.merged_into);
 518
 519         return u;
 520 }
 521
 522 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
 523         int r;
 524
 525         assert(u);
 526         assert(c);
 527
 528         if (c->std_output != EXEC_OUTPUT_KERNEL && c->std_output != EXEC_OUTPUT_SYSLOG)
 529                 return 0;
 530
 531         /* If syslog or kernel logging is requested, make sure our own
 532          * logging daemon is run first. */
 533
 534         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 535                 return r;
 536
 537         if (u->meta.manager->running_as != MANAGER_SESSION)
 538                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
 539                         return r;
 540
 541         return 0;
 542 }
 543
 544 const char *unit_description(Unit *u) {
 545         assert(u);
 546
 547         if (u->meta.description)
 548                 return u->meta.description;
 549
 550         return u->meta.id;
 551 }
 552
 553 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 554         char *t;
 555         UnitDependency d;
 556         Iterator i;
 557         char *p2;
 558         const char *prefix2;
 559         CGroupBonding *b;
 560         char timestamp1[FORMAT_TIMESTAMP_MAX], timestamp2[FORMAT_TIMESTAMP_MAX];
 561
 562         assert(u);
 563         assert(u->meta.type >= 0);
 564
 565         if (!prefix)
 566                 prefix = "";
 567         p2 = strappend(prefix, "\t");
 568         prefix2 = p2 ? p2 : prefix;
 569
 570         fprintf(f,
 571                 "%s→ Unit %s:\n"
 572                 "%s\tDescription: %s\n"
 573                 "%s\tInstance: %s\n"
 574                 "%s\tUnit Load State: %s\n"
 575                 "%s\tUnit Active State: %s\n"
 576                 "%s\tActive Enter Timestamp: %s\n"
 577                 "%s\tActive Exit Timestamp: %s\n"
 578                 "%s\tGC Check Good: %s\n",
 579                 prefix, u->meta.id,
 580                 prefix, unit_description(u),
 581                 prefix, strna(u->meta.instance),
 582                 prefix, unit_load_state_to_string(u->meta.load_state),
 583                 prefix, unit_active_state_to_string(unit_active_state(u)),
 584                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.active_enter_timestamp)),
 585                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_exit_timestamp)),
 586                 prefix, yes_no(unit_check_gc(u)));
 587
 588         SET_FOREACH(t, u->meta.names, i)
 589                 fprintf(f, "%s\tName: %s\n", prefix, t);
 590
 591         if (u->meta.fragment_path)
 592                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
 593
 594         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 595                 Unit *other;
 596
 597                 SET_FOREACH(other, u->meta.dependencies[d], i)
 598                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
 599         }
 600
 601         if (u->meta.load_state == UNIT_LOADED) {
 602                 fprintf(f,
 603                         "%s\tRecursive Stop: %s\n"
 604                         "%s\tStop When Unneeded: %s\n",
 605                         prefix, yes_no(u->meta.recursive_stop),
 606                         prefix, yes_no(u->meta.stop_when_unneeded));
 607
 608                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
 609                         fprintf(f, "%s\tControlGroup: %s:%s\n",
 610                                 prefix, b->controller, b->path);
 611
 612                 if (UNIT_VTABLE(u)->dump)
 613                         UNIT_VTABLE(u)->dump(u, f, prefix2);
 614
 615         } else if (u->meta.load_state == UNIT_MERGED)
 616                 fprintf(f,
 617                         "%s\tMerged into: %s\n",
 618                         prefix, u->meta.merged_into->meta.id);
 619
 620         if (u->meta.job)
 621                 job_dump(u->meta.job, f, prefix2);
 622
 623         free(p2);
 624 }
 625
 626 /* Common implementation for multiple backends */
 627 int unit_load_fragment_and_dropin(Unit *u) {
 628         int r;
 629
 630         assert(u);
 631
 632         /* Load a .service file */
 633         if ((r = unit_load_fragment(u)) < 0)
 634                 return r;
 635
 636         if (u->meta.load_state == UNIT_STUB)
 637                 return -ENOENT;
 638
 639         /* Load drop-in directory data */
 640         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 641                 return r;
 642
 643         return 0;
 644 }
 645
 646 /* Common implementation for multiple backends */
 647 int unit_load_fragment_and_dropin_optional(Unit *u) {
 648         int r;
 649
 650         assert(u);
 651
 652         /* Same as unit_load_fragment_and_dropin(), but whether
 653          * something can be loaded or not doesn't matter. */
 654
 655         /* Load a .service file */
 656         if ((r = unit_load_fragment(u)) < 0)
 657                 return r;
 658
 659         if (u->meta.load_state == UNIT_STUB)
 660                 u->meta.load_state = UNIT_LOADED;
 661
 662         /* Load drop-in directory data */
 663         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
 664                 return r;
 665
 666         return 0;
 667 }
 668
 669 /* Common implementation for multiple backends */
 670 int unit_load_nop(Unit *u) {
 671         assert(u);
 672
 673         if (u->meta.load_state == UNIT_STUB)
 674                 u->meta.load_state = UNIT_LOADED;
 675
 676         return 0;
 677 }
 678
 679 int unit_load(Unit *u) {
 680         int r;
 681
 682         assert(u);
 683
 684         if (u->meta.in_load_queue) {
 685                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 686                 u->meta.in_load_queue = false;
 687         }
 688
 689         if (u->meta.type == _UNIT_TYPE_INVALID)
 690                 return -EINVAL;
 691
 692         if (u->meta.load_state != UNIT_STUB)
 693                 return 0;
 694
 695         if (UNIT_VTABLE(u)->load)
 696                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
 697                         goto fail;
 698
 699         if (u->meta.load_state == UNIT_STUB) {
 700                 r = -ENOENT;
 701                 goto fail;
 702         }
 703
 704         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
 705
 706         unit_add_to_dbus_queue(unit_follow_merge(u));
 707         unit_add_to_gc_queue(u);
 708
 709         return 0;
 710
 711 fail:
 712         u->meta.load_state = UNIT_FAILED;
 713         unit_add_to_dbus_queue(u);
 714
 715         log_error("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
 716
 717         return r;
 718 }
 719
 720 /* Errors:
 721  *         -EBADR:    This unit type does not support starting.
 722  *         -EALREADY: Unit is already started.
 723  *         -EAGAIN:   An operation is already in progress. Retry later.
 724  */
 725 int unit_start(Unit *u) {
 726         UnitActiveState state;
 727
 728         assert(u);
 729
 730         /* If this is already (being) started, then this will
 731          * succeed. Note that this will even succeed if this unit is
 732          * not startable by the user. This is relied on to detect when
 733          * we need to wait for units and when waiting is finished. */
 734         state = unit_active_state(u);
 735         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 736                 return -EALREADY;
 737
 738         /* If it is stopped, but we cannot start it, then fail */
 739         if (!UNIT_VTABLE(u)->start)
 740                 return -EBADR;
 741
 742         /* We don't suppress calls to ->start() here when we are
 743          * already starting, to allow this request to be used as a
 744          * "hurry up" call, for example when the unit is in some "auto
 745          * restart" state where it waits for a holdoff timer to elapse
 746          * before it will start again. */
 747
 748         unit_add_to_dbus_queue(u);
 749         return UNIT_VTABLE(u)->start(u);
 750 }
 751
 752 bool unit_can_start(Unit *u) {
 753         assert(u);
 754
 755         return !!UNIT_VTABLE(u)->start;
 756 }
 757
 758 /* Errors:
 759  *         -EBADR:    This unit type does not support stopping.
 760  *         -EALREADY: Unit is already stopped.
 761  *         -EAGAIN:   An operation is already in progress. Retry later.
 762  */
 763 int unit_stop(Unit *u) {
 764         UnitActiveState state;
 765
 766         assert(u);
 767
 768         state = unit_active_state(u);
 769         if (state == UNIT_INACTIVE)
 770                 return -EALREADY;
 771
 772         if (!UNIT_VTABLE(u)->stop)
 773                 return -EBADR;
 774
 775         unit_add_to_dbus_queue(u);
 776         return UNIT_VTABLE(u)->stop(u);
 777 }
 778
 779 /* Errors:
 780  *         -EBADR:    This unit type does not support reloading.
 781  *         -ENOEXEC:  Unit is not started.
 782  *         -EAGAIN:   An operation is already in progress. Retry later.
 783  */
 784 int unit_reload(Unit *u) {
 785         UnitActiveState state;
 786
 787         assert(u);
 788
 789         if (!unit_can_reload(u))
 790                 return -EBADR;
 791
 792         state = unit_active_state(u);
 793         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 794                 return -EALREADY;
 795
 796         if (unit_active_state(u) != UNIT_ACTIVE)
 797                 return -ENOEXEC;
 798
 799         unit_add_to_dbus_queue(u);
 800         return UNIT_VTABLE(u)->reload(u);
 801 }
 802
 803 bool unit_can_reload(Unit *u) {
 804         assert(u);
 805
 806         if (!UNIT_VTABLE(u)->reload)
 807                 return false;
 808
 809         if (!UNIT_VTABLE(u)->can_reload)
 810                 return true;
 811
 812         return UNIT_VTABLE(u)->can_reload(u);
 813 }
 814
 815 static void unit_check_uneeded(Unit *u) {
 816         Iterator i;
 817         Unit *other;
 818
 819         assert(u);
 820
 821         /* If this service shall be shut down when unneeded then do
 822          * so. */
 823
 824         if (!u->meta.stop_when_unneeded)
 825                 return;
 826
 827         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 828                 return;
 829
 830         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 831                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 832                         return;
 833
 834         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
 835                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 836                         return;
 837
 838         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 839                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 840                         return;
 841
 842         log_debug("Service %s is not needed anymore. Stopping.", u->meta.id);
 843
 844         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 845         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 846 }
 847
 848 static void retroactively_start_dependencies(Unit *u) {
 849         Iterator i;
 850         Unit *other;
 851
 852         assert(u);
 853         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 854
 855         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 856                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 857                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 858
 859         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 860                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 861                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 862
 863         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 864                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 865                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 866
 867         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 868                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 869                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 870
 871         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 872                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 873                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 874 }
 875
 876 static void retroactively_stop_dependencies(Unit *u) {
 877         Iterator i;
 878         Unit *other;
 879
 880         assert(u);
 881         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 882
 883         if (u->meta.recursive_stop) {
 884                 /* Pull down units need us recursively if enabled */
 885                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 886                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 887                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 888         }
 889
 890         /* Garbage collect services that might not be needed anymore, if enabled */
 891         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 892                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 893                         unit_check_uneeded(other);
 894         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
 895                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 896                         unit_check_uneeded(other);
 897         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 898                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 899                         unit_check_uneeded(other);
 900         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 901                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 902                         unit_check_uneeded(other);
 903         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
 904                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 905                         unit_check_uneeded(other);
 906 }
 907
 908 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 909         bool unexpected = false;
 910
 911         assert(u);
 912         assert(os < _UNIT_ACTIVE_STATE_MAX);
 913         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 914
 915         /* Note that this is called for all low-level state changes,
 916          * even if they might map to the same high-level
 917          * UnitActiveState! That means that ns == os is OK an expected
 918          * behaviour here. For example: if a mount point is remounted
 919          * this function will be called too and the utmp code below
 920          * relies on that! */
 921
 922         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 923                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 924         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 925                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 926
 927         if (u->meta.job) {
 928
 929                 if (u->meta.job->state == JOB_WAITING)
 930
 931                         /* So we reached a different state for this
 932                          * job. Let's see if we can run it now if it
 933                          * failed previously due to EAGAIN. */
 934                         job_add_to_run_queue(u->meta.job);
 935
 936                 else {
 937                         assert(u->meta.job->state == JOB_RUNNING);
 938
 939                         /* Let's check whether this state change
 940                          * constitutes a finished job, or maybe
 941                          * cotradicts a running job and hence needs to
 942                          * invalidate jobs. */
 943
 944                         switch (u->meta.job->type) {
 945
 946                         case JOB_START:
 947                         case JOB_VERIFY_ACTIVE:
 948
 949                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
 950                                         job_finish_and_invalidate(u->meta.job, true);
 951                                 else if (ns != UNIT_ACTIVATING) {
 952                                         unexpected = true;
 953                                         job_finish_and_invalidate(u->meta.job, false);
 954                                 }
 955
 956                                 break;
 957
 958                         case JOB_RELOAD:
 959                         case JOB_RELOAD_OR_START:
 960
 961                                 if (ns == UNIT_ACTIVE)
 962                                         job_finish_and_invalidate(u->meta.job, true);
 963                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_ACTIVE_RELOADING) {
 964                                         unexpected = true;
 965                                         job_finish_and_invalidate(u->meta.job, false);
 966                                 }
 967
 968                                 break;
 969
 970                         case JOB_STOP:
 971                         case JOB_RESTART:
 972                         case JOB_TRY_RESTART:
 973
 974                                 if (ns == UNIT_INACTIVE)
 975                                         job_finish_and_invalidate(u->meta.job, true);
 976                                 else if (ns != UNIT_DEACTIVATING) {
 977                                         unexpected = true;
 978                                         job_finish_and_invalidate(u->meta.job, false);
 979                                 }
 980
 981                                 break;
 982
 983                         default:
 984                                 assert_not_reached("Job type unknown");
 985                         }
 986                 }
 987         }
 988
 989         /* If this state change happened without being requested by a
 990          * job, then let's retroactively start or stop dependencies */
 991
 992         if (unexpected) {
 993                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 994                         retroactively_start_dependencies(u);
 995                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 996                         retroactively_stop_dependencies(u);
 997         }
 998
 999         /* Some names are special */
1000         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1001                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1002                         /* The bus just might have become available,
1003                          * hence try to connect to it, if we aren't
1004                          * yet connected. */
1005                         bus_init_system(u->meta.manager);
1006                         bus_init_api(u->meta.manager);
1007                 }
1008
1009                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1010                         /* The syslog daemon just might have become
1011                          * available, hence try to connect to it, if
1012                          * we aren't yet connected. */
1013                         log_open_syslog();
1014
1015                 if (u->meta.type == UNIT_MOUNT)
1016                         /* Another directory became available, let's
1017                          * check if that is enough to write our utmp
1018                          * entry. */
1019                         manager_write_utmp_reboot(u->meta.manager);
1020
1021                 if (u->meta.type == UNIT_TARGET)
1022                         /* A target got activated, maybe this is a runlevel? */
1023                         manager_write_utmp_runlevel(u->meta.manager, u);
1024
1025         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1026
1027                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1028                         /* The syslog daemon might just have
1029                          * terminated, hence try to disconnect from
1030                          * it. */
1031                         log_close_syslog();
1032
1033                 /* We don't care about D-Bus here, since we'll get an
1034                  * asynchronous notification for it anyway. */
1035         }
1036
1037         /* Maybe we finished startup and are now ready for being
1038          * stopped because unneeded? */
1039         unit_check_uneeded(u);
1040
1041         unit_add_to_dbus_queue(u);
1042         unit_add_to_gc_queue(u);
1043 }
1044
1045 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1046         struct epoll_event ev;
1047
1048         assert(u);
1049         assert(fd >= 0);
1050         assert(w);
1051         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1052
1053         zero(ev);
1054         ev.data.ptr = w;
1055         ev.events = events;
1056
1057         if (epoll_ctl(u->meta.manager->epoll_fd,
1058                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1059                       fd,
1060                       &ev) < 0)
1061                 return -errno;
1062
1063         w->fd = fd;
1064         w->type = WATCH_FD;
1065         w->data.unit = u;
1066
1067         return 0;
1068 }
1069
1070 void unit_unwatch_fd(Unit *u, Watch *w) {
1071         assert(u);
1072         assert(w);
1073
1074         if (w->type == WATCH_INVALID)
1075                 return;
1076
1077         assert(w->type == WATCH_FD);
1078         assert(w->data.unit == u);
1079         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1080
1081         w->fd = -1;
1082         w->type = WATCH_INVALID;
1083         w->data.unit = NULL;
1084 }
1085
1086 int unit_watch_pid(Unit *u, pid_t pid) {
1087         assert(u);
1088         assert(pid >= 1);
1089
1090         /* Watch a specific PID. We only support one unit watching
1091          * each PID for now. */
1092
1093         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1094 }
1095
1096 void unit_unwatch_pid(Unit *u, pid_t pid) {
1097         assert(u);
1098         assert(pid >= 1);
1099
1100         hashmap_remove_value(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
1101 }
1102
1103 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1104         struct itimerspec its;
1105         int flags, fd;
1106         bool ours;
1107
1108         assert(u);
1109         assert(w);
1110         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
1111
1112         /* This will try to reuse the old timer if there is one */
1113
1114         if (w->type == WATCH_TIMER) {
1115                 ours = false;
1116                 fd = w->fd;
1117         } else {
1118                 ours = true;
1119                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1120                         return -errno;
1121         }
1122
1123         zero(its);
1124
1125         if (delay <= 0) {
1126                 /* Set absolute time in the past, but not 0, since we
1127                  * don't want to disarm the timer */
1128                 its.it_value.tv_sec = 0;
1129                 its.it_value.tv_nsec = 1;
1130
1131                 flags = TFD_TIMER_ABSTIME;
1132         } else {
1133                 timespec_store(&its.it_value, delay);
1134                 flags = 0;
1135         }
1136
1137         /* This will also flush the elapse counter */
1138         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1139                 goto fail;
1140
1141         if (w->type == WATCH_INVALID) {
1142                 struct epoll_event ev;
1143
1144                 zero(ev);
1145                 ev.data.ptr = w;
1146                 ev.events = EPOLLIN;
1147
1148                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1149                         goto fail;
1150         }
1151
1152         w->fd = fd;
1153         w->type = WATCH_TIMER;
1154         w->data.unit = u;
1155
1156         return 0;
1157
1158 fail:
1159         if (ours)
1160                 close_nointr_nofail(fd);
1161
1162         return -errno;
1163 }
1164
1165 void unit_unwatch_timer(Unit *u, Watch *w) {
1166         assert(u);
1167         assert(w);
1168
1169         if (w->type == WATCH_INVALID)
1170                 return;
1171
1172         assert(w->type == WATCH_TIMER && w->data.unit == u);
1173
1174         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1175         close_nointr_nofail(w->fd);
1176
1177         w->fd = -1;
1178         w->type = WATCH_INVALID;
1179         w->data.unit = NULL;
1180 }
1181
1182 bool unit_job_is_applicable(Unit *u, JobType j) {
1183         assert(u);
1184         assert(j >= 0 && j < _JOB_TYPE_MAX);
1185
1186         switch (j) {
1187
1188         case JOB_VERIFY_ACTIVE:
1189         case JOB_START:
1190                 return true;
1191
1192         case JOB_STOP:
1193         case JOB_RESTART:
1194         case JOB_TRY_RESTART:
1195                 return unit_can_start(u);
1196
1197         case JOB_RELOAD:
1198                 return unit_can_reload(u);
1199
1200         case JOB_RELOAD_OR_START:
1201                 return unit_can_reload(u) && unit_can_start(u);
1202
1203         default:
1204                 assert_not_reached("Invalid job type");
1205         }
1206 }
1207
1208 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1209
1210         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1211                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1212                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1213                 [UNIT_WANTS] = UNIT_WANTED_BY,
1214                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1215                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1216                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1217                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1218                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1219                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
1220                 [UNIT_BEFORE] = UNIT_AFTER,
1221                 [UNIT_AFTER] = UNIT_BEFORE,
1222                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1223                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1224         };
1225         int r, q = 0, v = 0, w = 0;
1226
1227         assert(u);
1228         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1229         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
1230         assert(other);
1231
1232         /* We won't allow dependencies on ourselves. We will not
1233          * consider them an error however. */
1234         if (u == other)
1235                 return 0;
1236
1237         if (UNIT_VTABLE(u)->no_requires &&
1238             (d == UNIT_REQUIRES ||
1239              d == UNIT_REQUIRES_OVERRIDABLE ||
1240              d == UNIT_REQUISITE ||
1241              d == UNIT_REQUISITE_OVERRIDABLE)) {
1242                     return -EINVAL;
1243         }
1244
1245         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
1246             (r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1247                 return r;
1248
1249         if (add_reference)
1250                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1251                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1252                         return r;
1253
1254         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1255                 return q;
1256
1257         if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1258                 r = v;
1259                 goto fail;
1260         }
1261
1262         if (add_reference) {
1263                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1264                         r = w;
1265                         goto fail;
1266                 }
1267
1268                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1269                         goto fail;
1270         }
1271
1272         unit_add_to_dbus_queue(u);
1273         return 0;
1274
1275 fail:
1276         if (q > 0)
1277                 set_remove(u->meta.dependencies[d], other);
1278
1279         if (v > 0)
1280                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1281
1282         if (w > 0)
1283                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1284
1285         return r;
1286 }
1287
1288 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1289         char *s;
1290
1291         assert(u);
1292         assert(name || path);
1293
1294         if (!name)
1295                 name = file_name_from_path(path);
1296
1297         if (!unit_name_is_template(name)) {
1298                 *p = NULL;
1299                 return name;
1300         }
1301
1302         if (u->meta.instance)
1303                 s = unit_name_replace_instance(name, u->meta.instance);
1304         else {
1305                 char *i;
1306
1307                 if (!(i = unit_name_to_prefix(u->meta.id)))
1308                         return NULL;
1309
1310                 s = unit_name_replace_instance(name, i);
1311                 free(i);
1312         }
1313
1314         if (!s)
1315                 return NULL;
1316
1317         *p = s;
1318         return s;
1319 }
1320
1321 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1322         Unit *other;
1323         int r;
1324         char *s;
1325
1326         assert(u);
1327         assert(name || path);
1328
1329         if (!(name = resolve_template(u, name, path, &s)))
1330                 return -ENOMEM;
1331
1332         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1333                 goto finish;
1334
1335         r = unit_add_dependency(u, d, other, add_reference);
1336
1337 finish:
1338         free(s);
1339         return r;
1340 }
1341
1342 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1343         Unit *other;
1344         int r;
1345         char *s;
1346
1347         assert(u);
1348         assert(name || path);
1349
1350         if (!(name = resolve_template(u, name, path, &s)))
1351                 return -ENOMEM;
1352
1353         if ((r = manager_load_unit(u->meta.manager, name, path, &other)) < 0)
1354                 goto finish;
1355
1356         r = unit_add_dependency(other, d, u, add_reference);
1357
1358 finish:
1359         free(s);
1360         return r;
1361 }
1362
1363 int set_unit_path(const char *p) {
1364         char *cwd, *c;
1365         int r;
1366
1367         /* This is mostly for debug purposes */
1368
1369         if (path_is_absolute(p)) {
1370                 if (!(c = strdup(p)))
1371                         return -ENOMEM;
1372         } else {
1373                 if (!(cwd = get_current_dir_name()))
1374                         return -errno;
1375
1376                 r = asprintf(&c, "%s/%s", cwd, p);
1377                 free(cwd);
1378
1379                 if (r < 0)
1380                         return -ENOMEM;
1381         }
1382
1383         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1384                 r = -errno;
1385                 free(c);
1386                 return r;
1387         }
1388
1389         return 0;
1390 }
1391
1392 char *unit_dbus_path(Unit *u) {
1393         char *p, *e;
1394
1395         assert(u);
1396
1397         if (!(e = bus_path_escape(u->meta.id)))
1398                 return NULL;
1399
1400         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1401                 free(e);
1402                 return NULL;
1403         }
1404
1405         free(e);
1406         return p;
1407 }
1408
1409 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1410         CGroupBonding *l;
1411         int r;
1412
1413         assert(u);
1414         assert(b);
1415         assert(b->path);
1416
1417         /* Ensure this hasn't been added yet */
1418         assert(!b->unit);
1419
1420         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1421         LIST_PREPEND(CGroupBonding, by_path, l, b);
1422
1423         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1424                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1425                 return r;
1426         }
1427
1428         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1429         b->unit = u;
1430
1431         return 0;
1432 }
1433
1434 static char *default_cgroup_path(Unit *u) {
1435         char *p;
1436         int r;
1437
1438         assert(u);
1439
1440         if (u->meta.instance) {
1441                 char *t;
1442
1443                 if (!(t = unit_name_template(u->meta.id)))
1444                         return NULL;
1445
1446                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1447                 free(t);
1448         } else
1449                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1450
1451         return r < 0 ? NULL : p;
1452 }
1453
1454 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1455         size_t n;
1456         char *controller = NULL, *path = NULL;
1457         CGroupBonding *b = NULL;
1458         int r;
1459
1460         assert(u);
1461         assert(name);
1462
1463         /* Detect controller name */
1464         n = strcspn(name, ":");
1465
1466         if (name[n] == 0 ||
1467             (name[n] == ':' && name[n+1] == 0)) {
1468
1469                 /* Only controller name, no path? */
1470
1471                 if (!(path = default_cgroup_path(u)))
1472                         return -ENOMEM;
1473
1474         } else {
1475                 const char *p;
1476
1477                 /* Controller name, and path. */
1478                 p = name+n+1;
1479
1480                 if (!path_is_absolute(p))
1481                         return -EINVAL;
1482
1483                 if (!(path = strdup(p)))
1484                         return -ENOMEM;
1485         }
1486
1487         if (n > 0)
1488                 controller = strndup(name, n);
1489         else
1490                 controller = strdup(u->meta.manager->cgroup_controller);
1491
1492         if (!controller) {
1493                 r = -ENOMEM;
1494                 goto fail;
1495         }
1496
1497         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1498                 r = -EEXIST;
1499                 goto fail;
1500         }
1501
1502         if (!(b = new0(CGroupBonding, 1))) {
1503                 r = -ENOMEM;
1504                 goto fail;
1505         }
1506
1507         b->controller = controller;
1508         b->path = path;
1509         b->only_us = false;
1510         b->clean_up = false;
1511
1512         if ((r = unit_add_cgroup(u, b)) < 0)
1513                 goto fail;
1514
1515         return 0;
1516
1517 fail:
1518         free(path);
1519         free(controller);
1520         free(b);
1521
1522         return r;
1523 }
1524
1525 int unit_add_default_cgroup(Unit *u) {
1526         CGroupBonding *b;
1527         int r = -ENOMEM;
1528
1529         assert(u);
1530
1531         /* Adds in the default cgroup data, if it wasn't specified yet */
1532
1533         if (unit_get_default_cgroup(u))
1534                 return 0;
1535
1536         if (!(b = new0(CGroupBonding, 1)))
1537                 return -ENOMEM;
1538
1539         if (!(b->controller = strdup(u->meta.manager->cgroup_controller)))
1540                 goto fail;
1541
1542         if (!(b->path = default_cgroup_path(u)))
1543                 goto fail;
1544
1545         b->clean_up = true;
1546         b->only_us = true;
1547
1548         if ((r = unit_add_cgroup(u, b)) < 0)
1549                 goto fail;
1550
1551         return 0;
1552
1553 fail:
1554         free(b->path);
1555         free(b->controller);
1556         free(b);
1557
1558         return r;
1559 }
1560
1561 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1562         assert(u);
1563
1564         return cgroup_bonding_find_list(u->meta.cgroup_bondings, u->meta.manager->cgroup_controller);
1565 }
1566
1567 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1568         char *t;
1569         int r;
1570
1571         assert(u);
1572         assert(type);
1573         assert(_found);
1574
1575         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1576                 return -ENOMEM;
1577
1578         assert(!unit_has_name(u, t));
1579
1580         r = manager_load_unit(u->meta.manager, t, NULL, _found);
1581         free(t);
1582
1583         assert(r < 0 || *_found != u);
1584
1585         return r;
1586 }
1587
1588 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1589         Unit *found;
1590         char *t;
1591
1592         assert(u);
1593         assert(type);
1594         assert(_found);
1595
1596         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1597                 return -ENOMEM;
1598
1599         assert(!unit_has_name(u, t));
1600
1601         found = manager_get_unit(u->meta.manager, t);
1602         free(t);
1603
1604         if (!found)
1605                 return -ENOENT;
1606
1607         *_found = found;
1608         return 0;
1609 }
1610
1611 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1612         Unit *u = userdata;
1613         assert(u);
1614
1615         return unit_name_to_prefix_and_instance(u->meta.id);
1616 }
1617
1618 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1619         Unit *u = userdata;
1620         assert(u);
1621
1622         return unit_name_to_prefix(u->meta.id);
1623 }
1624
1625 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1626         Unit *u = userdata;
1627         char *p, *r;
1628
1629         assert(u);
1630
1631         if (!(p = unit_name_to_prefix(u->meta.id)))
1632                 return NULL;
1633
1634         r = unit_name_unescape(p);
1635         free(p);
1636
1637         return r;
1638 }
1639
1640 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1641         Unit *u = userdata;
1642         assert(u);
1643
1644         if (u->meta.instance)
1645                 return unit_name_unescape(u->meta.instance);
1646
1647         return strdup("");
1648 }
1649
1650 char *unit_name_printf(Unit *u, const char* format) {
1651
1652         /*
1653          * This will use the passed string as format string and
1654          * replace the following specifiers:
1655          *
1656          * %n: the full id of the unit                 (foo@bar.waldo)
1657          * %N: the id of the unit without the suffix   (foo@bar)
1658          * %p: the prefix                              (foo)
1659          * %i: the instance                            (bar)
1660          */
1661
1662         const Specifier table[] = {
1663                 { 'n', specifier_string,              u->meta.id },
1664                 { 'N', specifier_prefix_and_instance, NULL },
1665                 { 'p', specifier_prefix,              NULL },
1666                 { 'i', specifier_string,              u->meta.instance },
1667                 { 0, NULL, NULL }
1668         };
1669
1670         assert(u);
1671         assert(format);
1672
1673         return specifier_printf(format, table, u);
1674 }
1675
1676 char *unit_full_printf(Unit *u, const char *format) {
1677
1678         /* This is similar to unit_name_printf() but also supports
1679          * unescaping */
1680
1681         const Specifier table[] = {
1682                 { 'n', specifier_string,              u->meta.id },
1683                 { 'N', specifier_prefix_and_instance, NULL },
1684                 { 'p', specifier_prefix,              NULL },
1685                 { 'P', specifier_prefix_unescaped,    NULL },
1686                 { 'i', specifier_string,              u->meta.instance },
1687                 { 'I', specifier_instance_unescaped,  NULL },
1688                 { 0, NULL, NULL }
1689         };
1690
1691         assert(u);
1692         assert(format);
1693
1694         return specifier_printf(format, table, u);
1695 }
1696
1697 char **unit_full_printf_strv(Unit *u, char **l) {
1698         size_t n;
1699         char **r, **i, **j;
1700
1701         /* Applies unit_full_printf to every entry in l */
1702
1703         assert(u);
1704
1705         n = strv_length(l);
1706         if (!(r = new(char*, n+1)))
1707                 return NULL;
1708
1709         for (i = l, j = r; *i; i++, j++)
1710                 if (!(*j = unit_full_printf(u, *i)))
1711                         goto fail;
1712
1713         *j = NULL;
1714         return r;
1715
1716 fail:
1717         j--;
1718         while (j >= r)
1719                 free(*j);
1720
1721         free(r);
1722
1723         return NULL;
1724 }
1725
1726 int unit_watch_bus_name(Unit *u, const char *name) {
1727         assert(u);
1728         assert(name);
1729
1730         /* Watch a specific name on the bus. We only support one unit
1731          * watching each name for now. */
1732
1733         return hashmap_put(u->meta.manager->watch_bus, name, u);
1734 }
1735
1736 void unit_unwatch_bus_name(Unit *u, const char *name) {
1737         assert(u);
1738         assert(name);
1739
1740         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1741 }
1742
1743 bool unit_can_serialize(Unit *u) {
1744         assert(u);
1745
1746         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1747 }
1748
1749 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1750         int r;
1751
1752         assert(u);
1753         assert(f);
1754         assert(fds);
1755
1756         if (!unit_can_serialize(u))
1757                 return 0;
1758
1759         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1760                 return r;
1761
1762         /* End marker */
1763         fputc('\n', f);
1764         return 0;
1765 }
1766
1767 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1768         va_list ap;
1769
1770         assert(u);
1771         assert(f);
1772         assert(key);
1773         assert(format);
1774
1775         fputs(key, f);
1776         fputc('=', f);
1777
1778         va_start(ap, format);
1779         vfprintf(f, format, ap);
1780         va_end(ap);
1781
1782         fputc('\n', f);
1783 }
1784
1785 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1786         assert(u);
1787         assert(f);
1788         assert(key);
1789         assert(value);
1790
1791         fprintf(f, "%s=%s\n", key, value);
1792 }
1793
1794 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1795         int r;
1796
1797         assert(u);
1798         assert(f);
1799         assert(fds);
1800
1801         if (!unit_can_serialize(u))
1802                 return 0;
1803
1804         for (;;) {
1805                 char line[1024], *l, *v;
1806                 size_t k;
1807
1808                 if (!fgets(line, sizeof(line), f)) {
1809                         if (feof(f))
1810                                 return 0;
1811                         return -errno;
1812                 }
1813
1814                 l = strstrip(line);
1815
1816                 /* End marker */
1817                 if (l[0] == 0)
1818                         return 0;
1819
1820                 k = strcspn(l, "=");
1821
1822                 if (l[k] == '=') {
1823                         l[k] = 0;
1824                         v = l+k+1;
1825                 } else
1826                         v = l+k;
1827
1828                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1829                         return r;
1830         }
1831 }
1832
1833
1834 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1835         [UNIT_SERVICE] = "service",
1836         [UNIT_TIMER] = "timer",
1837         [UNIT_SOCKET] = "socket",
1838         [UNIT_TARGET] = "target",
1839         [UNIT_DEVICE] = "device",
1840         [UNIT_MOUNT] = "mount",
1841         [UNIT_AUTOMOUNT] = "automount",
1842         [UNIT_SNAPSHOT] = "snapshot"
1843 };
1844
1845 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1846
1847 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1848         [UNIT_STUB] = "stub",
1849         [UNIT_LOADED] = "loaded",
1850         [UNIT_FAILED] = "failed",
1851         [UNIT_MERGED] = "merged"
1852 };
1853
1854 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1855
1856 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1857         [UNIT_ACTIVE] = "active",
1858         [UNIT_INACTIVE] = "inactive",
1859         [UNIT_ACTIVATING] = "activating",
1860         [UNIT_DEACTIVATING] = "deactivating"
1861 };
1862
1863 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1864
1865 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1866         [UNIT_REQUIRES] = "Requires",
1867         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
1868         [UNIT_WANTS] = "Wants",
1869         [UNIT_REQUISITE] = "Requisite",
1870         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
1871         [UNIT_REQUIRED_BY] = "RequiredBy",
1872         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
1873         [UNIT_WANTED_BY] = "WantedBy",
1874         [UNIT_CONFLICTS] = "Conflicts",
1875         [UNIT_BEFORE] = "Before",
1876         [UNIT_AFTER] = "After",
1877         [UNIT_REFERENCES] = "References",
1878         [UNIT_REFERENCED_BY] = "ReferencedBy"
1879 };
1880
1881 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
1882
1883 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1884         [KILL_CONTROL_GROUP] = "control-group",
1885         [KILL_PROCESS_GROUP] = "process-group",
1886         [KILL_PROCESS] = "process",
1887         [KILL_NONE] = "none"
1888 };
1889
1890 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);