unit.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <assert.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <sys/epoll.h>
   7 #include <sys/timerfd.h>
   8 #include <sys/poll.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11
  12 #include "set.h"
  13 #include "unit.h"
  14 #include "macro.h"
  15 #include "strv.h"
  16 #include "load-fragment.h"
  17 #include "load-dropin.h"
  18 #include "log.h"
  19
  20 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
  21         [UNIT_SERVICE] = &service_vtable,
  22         [UNIT_TIMER] = &timer_vtable,
  23         [UNIT_SOCKET] = &socket_vtable,
  24         [UNIT_TARGET] = &target_vtable,
  25         [UNIT_DEVICE] = &device_vtable,
  26         [UNIT_MOUNT] = &mount_vtable,
  27         [UNIT_AUTOMOUNT] = &automount_vtable,
  28         [UNIT_SNAPSHOT] = &snapshot_vtable
  29 };
  30
  31 UnitType unit_name_to_type(const char *n) {
  32         UnitType t;
  33
  34         assert(n);
  35
  36         for (t = 0; t < _UNIT_TYPE_MAX; t++)
  37                 if (endswith(n, unit_vtable[t]->suffix))
  38                         return t;
  39
  40         return _UNIT_TYPE_INVALID;
  41 }
  42
  43 #define VALID_CHARS                             \
  44         "0123456789"                            \
  45         "abcdefghijklmnopqrstuvwxyz"            \
  46         "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
  47         "-_.\\"
  48
  49 bool unit_name_is_valid(const char *n) {
  50         UnitType t;
  51         const char *e, *i;
  52
  53         assert(n);
  54
  55         if (strlen(n) >= UNIT_NAME_MAX)
  56                 return false;
  57
  58         t = unit_name_to_type(n);
  59         if (t < 0 || t >= _UNIT_TYPE_MAX)
  60                 return false;
  61
  62         if (!(e = strrchr(n, '.')))
  63                 return false;
  64
  65         if (e == n)
  66                 return false;
  67
  68         for (i = n; i < e; i++)
  69                 if (!strchr(VALID_CHARS, *i))
  70                         return false;
  71
  72         return true;
  73 }
  74
  75 char *unit_name_change_suffix(const char *n, const char *suffix) {
  76         char *e, *r;
  77         size_t a, b;
  78
  79         assert(n);
  80         assert(unit_name_is_valid(n));
  81         assert(suffix);
  82
  83         assert_se(e = strrchr(n, '.'));
  84         a = e - n;
  85         b = strlen(suffix);
  86
  87         if (!(r = new(char, a + b + 1)))
  88                 return NULL;
  89
  90         memcpy(r, n, a);
  91         memcpy(r+a, suffix, b+1);
  92
  93         return r;
  94 }
  95
  96 Unit *unit_new(Manager *m) {
  97         Unit *u;
  98
  99         assert(m);
 100
 101         if (!(u = new0(Unit, 1)))
 102                 return NULL;
 103
 104         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
 105                 free(u);
 106                 return NULL;
 107         }
 108
 109         u->meta.manager = m;
 110         u->meta.type = _UNIT_TYPE_INVALID;
 111
 112         return u;
 113 }
 114
 115 int unit_add_name(Unit *u, const char *text) {
 116         UnitType t;
 117         char *s;
 118         int r;
 119
 120         assert(u);
 121         assert(text);
 122
 123         if (!unit_name_is_valid(text))
 124                 return -EINVAL;
 125
 126         if ((t = unit_name_to_type(text)) == _UNIT_TYPE_INVALID)
 127                 return -EINVAL;
 128
 129         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type)
 130                 return -EINVAL;
 131
 132         if (!(s = strdup(text)))
 133                 return -ENOMEM;
 134
 135         if ((r = set_put(u->meta.names, s)) < 0) {
 136                 free(s);
 137
 138                 if (r == -EEXIST)
 139                         return 0;
 140
 141                 return r;
 142         }
 143
 144         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 145                 set_remove(u->meta.names, s);
 146                 free(s);
 147                 return r;
 148         }
 149
 150         if (u->meta.type == _UNIT_TYPE_INVALID)
 151                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 152
 153         u->meta.type = t;
 154
 155         if (!u->meta.id)
 156                 u->meta.id = s;
 157
 158         return 0;
 159 }
 160
 161 int unit_choose_id(Unit *u, const char *name) {
 162         char *s;
 163
 164         assert(u);
 165         assert(name);
 166
 167         /* Selects one of the names of this unit as the id */
 168
 169         if (!(s = set_get(u->meta.names, (char*) name)))
 170                 return -ENOENT;
 171
 172         u->meta.id = s;
 173         return 0;
 174 }
 175
 176 int unit_set_description(Unit *u, const char *description) {
 177         char *s;
 178
 179         assert(u);
 180
 181         if (!(s = strdup(description)))
 182                 return -ENOMEM;
 183
 184         free(u->meta.description);
 185         u->meta.description = s;
 186         return 0;
 187 }
 188
 189 void unit_add_to_load_queue(Unit *u) {
 190         assert(u);
 191
 192         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 193                 return;
 194
 195         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 196         u->meta.in_load_queue = true;
 197 }
 198
 199 static void bidi_set_free(Unit *u, Set *s) {
 200         Iterator i;
 201         Unit *other;
 202
 203         assert(u);
 204
 205         /* Frees the set and makes sure we are dropped from the
 206          * inverse pointers */
 207
 208         SET_FOREACH(other, s, i) {
 209                 UnitDependency d;
 210
 211                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 212                         set_remove(other->meta.dependencies[d], u);
 213         }
 214
 215         set_free(s);
 216 }
 217
 218 void unit_free(Unit *u) {
 219         UnitDependency d;
 220         Iterator i;
 221         char *t;
 222
 223         assert(u);
 224
 225         /* Detach from next 'bigger' objects */
 226
 227         SET_FOREACH(t, u->meta.names, i)
 228                 hashmap_remove_value(u->meta.manager->units, t, u);
 229
 230         if (u->meta.type != _UNIT_TYPE_INVALID)
 231                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 232
 233         if (u->meta.in_load_queue)
 234                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 235
 236         if (u->meta.load_state == UNIT_LOADED)
 237                 if (UNIT_VTABLE(u)->done)
 238                         UNIT_VTABLE(u)->done(u);
 239
 240         /* Free data and next 'smaller' objects */
 241         if (u->meta.job)
 242                 job_free(u->meta.job);
 243
 244         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 245                 bidi_set_free(u, u->meta.dependencies[d]);
 246
 247         free(u->meta.description);
 248         free(u->meta.load_path);
 249
 250         while ((t = set_steal_first(u->meta.names)))
 251                 free(t);
 252         set_free(u->meta.names);
 253
 254         free(u);
 255 }
 256
 257 UnitActiveState unit_active_state(Unit *u) {
 258         assert(u);
 259
 260         if (u->meta.load_state != UNIT_LOADED)
 261                 return UNIT_INACTIVE;
 262
 263         return UNIT_VTABLE(u)->active_state(u);
 264 }
 265
 266 static int ensure_merge(Set **s, Set *other) {
 267
 268         if (!other)
 269                 return 0;
 270
 271         if (*s)
 272                 return set_merge(*s, other);
 273
 274         if (!(*s = set_copy(other)))
 275                 return -ENOMEM;
 276
 277         return 0;
 278 }
 279
 280 /* FIXME: Does not rollback on failure! Needs to fix special unit
 281  * pointers. Needs to merge names and dependencies properly.*/
 282 int unit_merge(Unit *u, Unit *other) {
 283         int r;
 284         UnitDependency d;
 285
 286         assert(u);
 287         assert(other);
 288         assert(u->meta.manager == other->meta.manager);
 289
 290         /* This merges 'other' into 'unit'. FIXME: This does not
 291          * rollback on failure. */
 292
 293         if (u->meta.type != u->meta.type)
 294                 return -EINVAL;
 295
 296         if (u->meta.load_state != UNIT_STUB)
 297                 return -EINVAL;
 298
 299         /* Merge names */
 300         if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0)
 301                 return r;
 302
 303         /* Merge dependencies */
 304         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 305                 /* fixme, the inverse mapping is missing */
 306                 if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0)
 307                         return r;
 308
 309         return 0;
 310 }
 311
 312 const char* unit_id(Unit *u) {
 313         assert(u);
 314
 315         if (u->meta.id)
 316                 return u->meta.id;
 317
 318         return set_first(u->meta.names);
 319 }
 320
 321 const char *unit_description(Unit *u) {
 322         assert(u);
 323
 324         if (u->meta.description)
 325                 return u->meta.description;
 326
 327         return unit_id(u);
 328 }
 329
 330 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 331
 332         char *t;
 333         UnitDependency d;
 334         Iterator i;
 335         char *prefix2;
 336
 337         assert(u);
 338
 339         if (!prefix)
 340                 prefix = "";
 341         prefix2 = strappend(prefix, "\t");
 342         if (!prefix2)
 343                 prefix2 = "";
 344
 345         fprintf(f,
 346                 "%s→ Unit %s:\n"
 347                 "%s\tDescription: %s\n"
 348                 "%s\tUnit Load State: %s\n"
 349                 "%s\tUnit Active State: %s\n"
 350                 "%s\tRecursive Stop: %s\n"
 351                 "%s\tStop When Unneeded: %s\n",
 352                 prefix, unit_id(u),
 353                 prefix, unit_description(u),
 354                 prefix, unit_load_state_to_string(u->meta.load_state),
 355                 prefix, unit_active_state_to_string(unit_active_state(u)),
 356                 prefix, yes_no(u->meta.recursive_stop),
 357                 prefix, yes_no(u->meta.stop_when_unneeded));
 358
 359         if (u->meta.load_path)
 360                 fprintf(f, "%s\tLoad Path: %s\n", prefix, u->meta.load_path);
 361
 362         SET_FOREACH(t, u->meta.names, i)
 363                 fprintf(f, "%s\tName: %s\n", prefix, t);
 364
 365         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 366                 Unit *other;
 367
 368                 if (set_isempty(u->meta.dependencies[d]))
 369                         continue;
 370
 371                 SET_FOREACH(other, u->meta.dependencies[d], i)
 372                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), unit_id(other));
 373         }
 374
 375         if (UNIT_VTABLE(u)->dump)
 376                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 377
 378         if (u->meta.job)
 379                 job_dump(u->meta.job, f, prefix2);
 380
 381         free(prefix2);
 382 }
 383
 384 /* Common implementation for multiple backends */
 385 int unit_load_fragment_and_dropin(Unit *u) {
 386         int r, ret;
 387
 388         assert(u);
 389
 390         /* Load a .socket file */
 391         if ((r = unit_load_fragment(u)) < 0)
 392                 return r;
 393
 394         ret = r > 0;
 395
 396         /* Load drop-in directory data */
 397         if ((r = unit_load_dropin(u)) < 0)
 398                 return r;
 399
 400         return ret;
 401 }
 402
 403 int unit_load(Unit *u) {
 404         int r;
 405
 406         assert(u);
 407
 408         if (u->meta.in_load_queue) {
 409                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 410                 u->meta.in_load_queue = false;
 411         }
 412
 413         if (u->meta.load_state != UNIT_STUB)
 414                 return 0;
 415
 416         if (UNIT_VTABLE(u)->init)
 417                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 418                         goto fail;
 419
 420         u->meta.load_state = UNIT_LOADED;
 421         return 0;
 422
 423 fail:
 424         u->meta.load_state = UNIT_FAILED;
 425         return r;
 426 }
 427
 428 /* Errors:
 429  *         -EBADR:    This unit type does not support starting.
 430  *         -EALREADY: Unit is already started.
 431  *         -EAGAIN:   An operation is already in progress. Retry later.
 432  */
 433 int unit_start(Unit *u) {
 434         UnitActiveState state;
 435
 436         assert(u);
 437
 438         if (!UNIT_VTABLE(u)->start)
 439                 return -EBADR;
 440
 441         state = unit_active_state(u);
 442         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 443                 return -EALREADY;
 444
 445         /* We don't suppress calls to ->start() here when we are
 446          * already starting, to allow this request to be used as a
 447          * "hurry up" call, for example when the unit is in some "auto
 448          * restart" state where it waits for a holdoff timer to elapse
 449          * before it will start again. */
 450
 451         return UNIT_VTABLE(u)->start(u);
 452 }
 453
 454 bool unit_can_start(Unit *u) {
 455         assert(u);
 456
 457         return !!UNIT_VTABLE(u)->start;
 458 }
 459
 460 /* Errors:
 461  *         -EBADR:    This unit type does not support stopping.
 462  *         -EALREADY: Unit is already stopped.
 463  *         -EAGAIN:   An operation is already in progress. Retry later.
 464  */
 465 int unit_stop(Unit *u) {
 466         UnitActiveState state;
 467
 468         assert(u);
 469
 470         if (!UNIT_VTABLE(u)->stop)
 471                 return -EBADR;
 472
 473         state = unit_active_state(u);
 474         if (state == UNIT_INACTIVE)
 475                 return -EALREADY;
 476
 477         if (state == UNIT_DEACTIVATING)
 478                 return 0;
 479
 480         return UNIT_VTABLE(u)->stop(u);
 481 }
 482
 483 /* Errors:
 484  *         -EBADR:    This unit type does not support reloading.
 485  *         -ENOEXEC:  Unit is not started.
 486  *         -EAGAIN:   An operation is already in progress. Retry later.
 487  */
 488 int unit_reload(Unit *u) {
 489         UnitActiveState state;
 490
 491         assert(u);
 492
 493         if (!unit_can_reload(u))
 494                 return -EBADR;
 495
 496         state = unit_active_state(u);
 497         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 498                 return -EALREADY;
 499
 500         if (unit_active_state(u) != UNIT_ACTIVE)
 501                 return -ENOEXEC;
 502
 503         return UNIT_VTABLE(u)->reload(u);
 504 }
 505
 506 bool unit_can_reload(Unit *u) {
 507         assert(u);
 508
 509         if (!UNIT_VTABLE(u)->reload)
 510                 return false;
 511
 512         if (!UNIT_VTABLE(u)->can_reload)
 513                 return true;
 514
 515         return UNIT_VTABLE(u)->can_reload(u);
 516 }
 517
 518 static void unit_check_uneeded(Unit *u) {
 519         Iterator i;
 520         Unit *other;
 521
 522         assert(u);
 523
 524         /* If this service shall be shut down when unneeded then do
 525          * so. */
 526
 527         if (!u->meta.stop_when_unneeded)
 528                 return;
 529
 530         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 531                 return;
 532
 533         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 534                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 535                         return;
 536
 537         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 538                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 539                         return;
 540
 541         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 542                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 543                         return;
 544
 545         log_debug("Service %s is not needed anymore. Stopping.", unit_id(u));
 546
 547         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 548         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 549 }
 550
 551 static void retroactively_start_dependencies(Unit *u) {
 552         Iterator i;
 553         Unit *other;
 554
 555         assert(u);
 556         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 557
 558         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 559                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 560                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 561
 562         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 563                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 564                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 565
 566         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 567                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 568                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 569
 570         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 571                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 572                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 573
 574         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 575                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 576                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 577 }
 578
 579 static void retroactively_stop_dependencies(Unit *u) {
 580         Iterator i;
 581         Unit *other;
 582
 583         assert(u);
 584         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 585
 586         if (u->meta.recursive_stop) {
 587                 /* Pull down units need us recursively if enabled */
 588                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 589                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 590                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 591         }
 592
 593         /* Garbage collect services that might not be needed anymore, if enabled */
 594         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 595                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 596                         unit_check_uneeded(other);
 597         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 598                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 599                         unit_check_uneeded(other);
 600         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 601                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 602                         unit_check_uneeded(other);
 603         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 604                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 605                         unit_check_uneeded(other);
 606         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUISITE], i)
 607                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 608                         unit_check_uneeded(other);
 609 }
 610
 611 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 612         assert(u);
 613         assert(os < _UNIT_ACTIVE_STATE_MAX);
 614         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 615         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 616         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 617
 618         if (os == ns)
 619                 return;
 620
 621         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 622                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 623         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 624                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 625
 626         if (u->meta.job) {
 627
 628                 if (u->meta.job->state == JOB_WAITING)
 629
 630                         /* So we reached a different state for this
 631                          * job. Let's see if we can run it now if it
 632                          * failed previously due to EAGAIN. */
 633                         job_schedule_run(u->meta.job);
 634
 635                 else {
 636                         assert(u->meta.job->state == JOB_RUNNING);
 637
 638                         /* Let's check whether this state change
 639                          * constitutes a finished job, or maybe
 640                          * cotradicts a running job and hence needs to
 641                          * invalidate jobs. */
 642
 643                         switch (u->meta.job->type) {
 644
 645                         case JOB_START:
 646                         case JOB_VERIFY_ACTIVE:
 647
 648                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 649                                         job_finish_and_invalidate(u->meta.job, true);
 650                                         return;
 651                                 } else if (ns == UNIT_ACTIVATING)
 652                                         return;
 653                                 else
 654                                         job_finish_and_invalidate(u->meta.job, false);
 655
 656                                 break;
 657
 658                         case JOB_RELOAD:
 659                         case JOB_RELOAD_OR_START:
 660
 661                                 if (ns == UNIT_ACTIVE) {
 662                                         job_finish_and_invalidate(u->meta.job, true);
 663                                         return;
 664                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 665                                         return;
 666                                 else
 667                                         job_finish_and_invalidate(u->meta.job, false);
 668
 669                                 break;
 670
 671                         case JOB_STOP:
 672                         case JOB_RESTART:
 673                         case JOB_TRY_RESTART:
 674
 675                                 if (ns == UNIT_INACTIVE) {
 676                                         job_finish_and_invalidate(u->meta.job, true);
 677                                         return;
 678                                 } else if (ns == UNIT_DEACTIVATING)
 679                                         return;
 680                                 else
 681                                         job_finish_and_invalidate(u->meta.job, false);
 682
 683                                 break;
 684
 685                         default:
 686                                 assert_not_reached("Job type unknown");
 687                         }
 688                 }
 689         }
 690
 691         /* If this state change happened without being requested by a
 692          * job, then let's retroactively start or stop dependencies */
 693
 694         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 695                 retroactively_start_dependencies(u);
 696         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 697                 retroactively_stop_dependencies(u);
 698
 699         /* Maybe we finished startup and are now ready for being
 700          * stopped because unneeded? */
 701         unit_check_uneeded(u);
 702 }
 703
 704 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 705         struct epoll_event ev;
 706
 707         assert(u);
 708         assert(fd >= 0);
 709         assert(w);
 710         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
 711
 712         zero(ev);
 713         ev.data.ptr = w;
 714         ev.events = events;
 715
 716         if (epoll_ctl(u->meta.manager->epoll_fd,
 717                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 718                       fd,
 719                       &ev) < 0)
 720                 return -errno;
 721
 722         w->fd = fd;
 723         w->type = WATCH_FD;
 724         w->data.unit = u;
 725
 726         return 0;
 727 }
 728
 729 void unit_unwatch_fd(Unit *u, Watch *w) {
 730         assert(u);
 731         assert(w);
 732
 733         if (w->type == WATCH_INVALID)
 734                 return;
 735
 736         assert(w->type == WATCH_FD);
 737         assert(w->data.unit == u);
 738         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 739
 740         w->fd = -1;
 741         w->type = WATCH_INVALID;
 742         w->data.unit = NULL;
 743 }
 744
 745 int unit_watch_pid(Unit *u, pid_t pid) {
 746         assert(u);
 747         assert(pid >= 1);
 748
 749         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 750 }
 751
 752 void unit_unwatch_pid(Unit *u, pid_t pid) {
 753         assert(u);
 754         assert(pid >= 1);
 755
 756         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 757 }
 758
 759 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 760         struct itimerspec its;
 761         int flags, fd;
 762         bool ours;
 763
 764         assert(u);
 765         assert(w);
 766         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
 767
 768         /* This will try to reuse the old timer if there is one */
 769
 770         if (w->type == WATCH_TIMER) {
 771                 ours = false;
 772                 fd = w->fd;
 773         } else {
 774                 ours = true;
 775                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 776                         return -errno;
 777         }
 778
 779         zero(its);
 780
 781         if (delay <= 0) {
 782                 /* Set absolute time in the past, but not 0, since we
 783                  * don't want to disarm the timer */
 784                 its.it_value.tv_sec = 0;
 785                 its.it_value.tv_nsec = 1;
 786
 787                 flags = TFD_TIMER_ABSTIME;
 788         } else {
 789                 timespec_store(&its.it_value, delay);
 790                 flags = 0;
 791         }
 792
 793         /* This will also flush the elapse counter */
 794         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 795                 goto fail;
 796
 797         if (w->type == WATCH_INVALID) {
 798                 struct epoll_event ev;
 799
 800                 zero(ev);
 801                 ev.data.ptr = w;
 802                 ev.events = EPOLLIN;
 803
 804                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 805                         goto fail;
 806         }
 807
 808         w->fd = fd;
 809         w->type = WATCH_TIMER;
 810         w->data.unit = u;
 811
 812         return 0;
 813
 814 fail:
 815         if (ours)
 816                 close_nointr_nofail(fd);
 817
 818         return -errno;
 819 }
 820
 821 void unit_unwatch_timer(Unit *u, Watch *w) {
 822         assert(u);
 823         assert(w);
 824
 825         if (w->type == WATCH_INVALID)
 826                 return;
 827
 828         assert(w->type == WATCH_TIMER && w->data.unit == u);
 829
 830         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 831         assert_se(close_nointr(w->fd) == 0);
 832
 833         w->fd = -1;
 834         w->type = WATCH_INVALID;
 835         w->data.unit = NULL;
 836 }
 837
 838 bool unit_job_is_applicable(Unit *u, JobType j) {
 839         assert(u);
 840         assert(j >= 0 && j < _JOB_TYPE_MAX);
 841
 842         switch (j) {
 843
 844         case JOB_VERIFY_ACTIVE:
 845         case JOB_START:
 846                 return true;
 847
 848         case JOB_STOP:
 849         case JOB_RESTART:
 850         case JOB_TRY_RESTART:
 851                 return unit_can_start(u);
 852
 853         case JOB_RELOAD:
 854                 return unit_can_reload(u);
 855
 856         case JOB_RELOAD_OR_START:
 857                 return unit_can_reload(u) && unit_can_start(u);
 858
 859         default:
 860                 assert_not_reached("Invalid job type");
 861         }
 862 }
 863
 864 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 865
 866         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 867                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 868                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 869                 [UNIT_WANTS] = UNIT_WANTED_BY,
 870                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 871                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 872                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 873                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 874                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 875                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 876                 [UNIT_BEFORE] = UNIT_AFTER,
 877                 [UNIT_AFTER] = UNIT_BEFORE
 878         };
 879         int r;
 880
 881         assert(u);
 882         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 883         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 884         assert(other);
 885
 886         /* We won't allow dependencies on ourselves. We will not
 887          * consider them an error however. */
 888         if (u == other)
 889                 return 0;
 890
 891         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 892                 return r;
 893
 894         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 895                 return r;
 896
 897         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 898                 return r;
 899
 900         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 901                 set_remove(u->meta.dependencies[d], other);
 902                 return r;
 903         }
 904
 905         return 0;
 906 }
 907
 908 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 909         Unit *other;
 910         int r;
 911
 912         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 913                 return r;
 914
 915         if ((r = unit_add_dependency(u, d, other)) < 0)
 916                 return r;
 917
 918         return 0;
 919 }
 920
 921 const char *unit_path(void) {
 922         char *e;
 923
 924         if ((e = getenv("UNIT_PATH")))
 925                 if (path_is_absolute(e))
 926                     return e;
 927
 928         return UNIT_PATH;
 929 }
 930
 931 int set_unit_path(const char *p) {
 932         char *cwd, *c;
 933         int r;
 934
 935         /* This is mostly for debug purposes */
 936
 937         if (path_is_absolute(p)) {
 938                 if (!(c = strdup(p)))
 939                         return -ENOMEM;
 940         } else {
 941                 if (!(cwd = get_current_dir_name()))
 942                         return -errno;
 943
 944                 r = asprintf(&c, "%s/%s", cwd, p);
 945                 free(cwd);
 946
 947                 if (r < 0)
 948                         return -ENOMEM;
 949         }
 950
 951         if (setenv("UNIT_PATH", c, 0) < 0) {
 952                 r = -errno;
 953                 free(c);
 954                 return r;
 955         }
 956
 957         return 0;
 958 }
 959
 960 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
 961         char *r, *t;
 962         const char *f;
 963         size_t a, b, c;
 964
 965         assert(path);
 966
 967         /* Takes a path and a suffix and prefix and makes a nice
 968          * string suitable as unit name of it, escaping all weird
 969          * chars on the way.
 970          *
 971          * / becomes ., and all chars not alloweed in a unit name get
 972          * escaped as \xFF, including \ and ., of course. This
 973          * escaping is hence reversible.
 974          */
 975
 976         if (!prefix)
 977                 prefix = "";
 978
 979         if (!suffix)
 980                 suffix = "";
 981
 982         a = strlen(prefix);
 983         b = strlen(path);
 984         c = strlen(suffix);
 985
 986         if (!(r = new(char, a+b*4+c+1)))
 987                 return NULL;
 988
 989         memcpy(r, prefix, a);
 990
 991         for (f = path, t = r+a; *f; f++) {
 992                 if (*f == '/')
 993                         *(t++) = '.';
 994                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
 995                         *(t++) = '\\';
 996                         *(t++) = 'x';
 997                         *(t++) = hexchar(*f > 4);
 998                         *(t++) = hexchar(*f);
 999                 } else
1000                         *(t++) = *f;
1001         }
1002
1003         memcpy(t, suffix, c+1);
1004
1005         return r;
1006 }
1007
1008 char *unit_dbus_path(Unit *u) {
1009         char *p, *e;
1010
1011         assert(u);
1012
1013         if (!(e = bus_path_escape(unit_id(u))))
1014                 return NULL;
1015
1016         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1017                 free(e);
1018                 return NULL;
1019         }
1020
1021         free(e);
1022         return p;
1023 }
1024
1025 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1026         [UNIT_SERVICE] = "service",
1027         [UNIT_TIMER] = "timer",
1028         [UNIT_SOCKET] = "socket",
1029         [UNIT_TARGET] = "target",
1030         [UNIT_DEVICE] = "device",
1031         [UNIT_MOUNT] = "mount",
1032         [UNIT_AUTOMOUNT] = "automount",
1033         [UNIT_SNAPSHOT] = "snapshot"
1034 };
1035
1036 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1037
1038 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1039         [UNIT_STUB] = "stub",
1040         [UNIT_LOADED] = "loaded",
1041         [UNIT_FAILED] = "failed"
1042 };
1043
1044 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1045
1046 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1047         [UNIT_ACTIVE] = "active",
1048         [UNIT_INACTIVE] = "inactive",
1049         [UNIT_ACTIVATING] = "activating",
1050         [UNIT_DEACTIVATING] = "deactivating"
1051 };
1052
1053 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1054
1055 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1056         [UNIT_REQUIRES] = "Requires",
1057         [UNIT_SOFT_REQUIRES] = "SoftRequires",
1058         [UNIT_WANTS] = "Wants",
1059         [UNIT_REQUISITE] = "Requisite",
1060         [UNIT_SOFT_REQUISITE] = "SoftRequisite",
1061         [UNIT_REQUIRED_BY] = "RequiredBy",
1062         [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
1063         [UNIT_WANTED_BY] = "WantedBy",
1064         [UNIT_CONFLICTS] = "Conflicts",
1065         [UNIT_BEFORE] = "Before",
1066         [UNIT_AFTER] = "After",
1067 };
1068
1069 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);