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         static const char* const load_state_table[_UNIT_LOAD_STATE_MAX] = {
 333                 [UNIT_STUB] = "stub",
 334                 [UNIT_LOADED] = "loaded",
 335                 [UNIT_FAILED] = "failed"
 336         };
 337
 338         static const char* const active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
 339                 [UNIT_ACTIVE] = "active",
 340                 [UNIT_INACTIVE] = "inactive",
 341                 [UNIT_ACTIVATING] = "activating",
 342                 [UNIT_DEACTIVATING] = "deactivating"
 343         };
 344
 345         static const char* const dependency_table[_UNIT_DEPENDENCY_MAX] = {
 346                 [UNIT_REQUIRES] = "Requires",
 347                 [UNIT_SOFT_REQUIRES] = "SoftRequires",
 348                 [UNIT_WANTS] = "Wants",
 349                 [UNIT_REQUISITE] = "Requisite",
 350                 [UNIT_SOFT_REQUISITE] = "SoftRequisite",
 351                 [UNIT_REQUIRED_BY] = "RequiredBy",
 352                 [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
 353                 [UNIT_WANTED_BY] = "WantedBy",
 354                 [UNIT_CONFLICTS] = "Conflicts",
 355                 [UNIT_BEFORE] = "Before",
 356                 [UNIT_AFTER] = "After",
 357         };
 358
 359         char *t;
 360         UnitDependency d;
 361         Iterator i;
 362         char *prefix2;
 363
 364         assert(u);
 365
 366         if (!prefix)
 367                 prefix = "";
 368         prefix2 = strappend(prefix, "\t");
 369         if (!prefix2)
 370                 prefix2 = "";
 371
 372         fprintf(f,
 373                 "%s→ Unit %s:\n"
 374                 "%s\tDescription: %s\n"
 375                 "%s\tUnit Load State: %s\n"
 376                 "%s\tUnit Active State: %s\n"
 377                 "%s\tRecursive Deactivate: %s\n"
 378                 "%s\tStop When Unneeded: %s\n",
 379                 prefix, unit_id(u),
 380                 prefix, unit_description(u),
 381                 prefix, load_state_table[u->meta.load_state],
 382                 prefix, active_state_table[unit_active_state(u)],
 383                 prefix, yes_no(u->meta.recursive_stop),
 384                 prefix, yes_no(u->meta.stop_when_unneeded));
 385
 386         if (u->meta.load_path)
 387                 fprintf(f, "%s\tLoad Path: %s\n", prefix, u->meta.load_path);
 388
 389         SET_FOREACH(t, u->meta.names, i)
 390                 fprintf(f, "%s\tName: %s\n", prefix, t);
 391
 392         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 393                 Unit *other;
 394
 395                 if (set_isempty(u->meta.dependencies[d]))
 396                         continue;
 397
 398                 SET_FOREACH(other, u->meta.dependencies[d], i)
 399                         fprintf(f, "%s\t%s: %s\n", prefix, dependency_table[d], unit_id(other));
 400         }
 401
 402         if (UNIT_VTABLE(u)->dump)
 403                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 404
 405         if (u->meta.job)
 406                 job_dump(u->meta.job, f, prefix2);
 407
 408         free(prefix2);
 409 }
 410
 411 /* Common implementation for multiple backends */
 412 int unit_load_fragment_and_dropin(Unit *u) {
 413         int r, ret;
 414
 415         assert(u);
 416
 417         /* Load a .socket file */
 418         if ((r = unit_load_fragment(u)) < 0)
 419                 return r;
 420
 421         ret = r > 0;
 422
 423         /* Load drop-in directory data */
 424         if ((r = unit_load_dropin(u)) < 0)
 425                 return r;
 426
 427         return ret;
 428 }
 429
 430 int unit_load(Unit *u) {
 431         int r;
 432
 433         assert(u);
 434
 435         if (u->meta.in_load_queue) {
 436                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 437                 u->meta.in_load_queue = false;
 438         }
 439
 440         if (u->meta.load_state != UNIT_STUB)
 441                 return 0;
 442
 443         if (UNIT_VTABLE(u)->init)
 444                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 445                         goto fail;
 446
 447         u->meta.load_state = UNIT_LOADED;
 448         return 0;
 449
 450 fail:
 451         u->meta.load_state = UNIT_FAILED;
 452         return r;
 453 }
 454
 455 /* Errors:
 456  *         -EBADR:    This unit type does not support starting.
 457  *         -EALREADY: Unit is already started.
 458  *         -EAGAIN:   An operation is already in progress. Retry later.
 459  */
 460 int unit_start(Unit *u) {
 461         UnitActiveState state;
 462
 463         assert(u);
 464
 465         if (!UNIT_VTABLE(u)->start)
 466                 return -EBADR;
 467
 468         state = unit_active_state(u);
 469         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 470                 return -EALREADY;
 471
 472         /* We don't suppress calls to ->start() here when we are
 473          * already starting, to allow this request to be used as a
 474          * "hurry up" call, for example when the unit is in some "auto
 475          * restart" state where it waits for a holdoff timer to elapse
 476          * before it will start again. */
 477
 478         return UNIT_VTABLE(u)->start(u);
 479 }
 480
 481 bool unit_can_start(Unit *u) {
 482         assert(u);
 483
 484         return !!UNIT_VTABLE(u)->start;
 485 }
 486
 487 /* Errors:
 488  *         -EBADR:    This unit type does not support stopping.
 489  *         -EALREADY: Unit is already stopped.
 490  *         -EAGAIN:   An operation is already in progress. Retry later.
 491  */
 492 int unit_stop(Unit *u) {
 493         UnitActiveState state;
 494
 495         assert(u);
 496
 497         if (!UNIT_VTABLE(u)->stop)
 498                 return -EBADR;
 499
 500         state = unit_active_state(u);
 501         if (state == UNIT_INACTIVE)
 502                 return -EALREADY;
 503
 504         if (state == UNIT_DEACTIVATING)
 505                 return 0;
 506
 507         return UNIT_VTABLE(u)->stop(u);
 508 }
 509
 510 /* Errors:
 511  *         -EBADR:    This unit type does not support reloading.
 512  *         -ENOEXEC:  Unit is not started.
 513  *         -EAGAIN:   An operation is already in progress. Retry later.
 514  */
 515 int unit_reload(Unit *u) {
 516         UnitActiveState state;
 517
 518         assert(u);
 519
 520         if (!unit_can_reload(u))
 521                 return -EBADR;
 522
 523         state = unit_active_state(u);
 524         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 525                 return -EALREADY;
 526
 527         if (unit_active_state(u) != UNIT_ACTIVE)
 528                 return -ENOEXEC;
 529
 530         return UNIT_VTABLE(u)->reload(u);
 531 }
 532
 533 bool unit_can_reload(Unit *u) {
 534         assert(u);
 535
 536         if (!UNIT_VTABLE(u)->reload)
 537                 return false;
 538
 539         if (!UNIT_VTABLE(u)->can_reload)
 540                 return true;
 541
 542         return UNIT_VTABLE(u)->can_reload(u);
 543 }
 544
 545 static void unit_check_uneeded(Unit *u) {
 546         Iterator i;
 547         Unit *other;
 548
 549         assert(u);
 550
 551         /* If this service shall be shut down when unneeded then do
 552          * so. */
 553
 554         if (!u->meta.stop_when_unneeded)
 555                 return;
 556
 557         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 558                 return;
 559
 560         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 561                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 562                         return;
 563
 564         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 565                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 566                         return;
 567
 568         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 569                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 570                         return;
 571
 572         log_debug("Service %s is not needed anymore. Stopping.", unit_id(u));
 573
 574         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 575         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 576 }
 577
 578 static void retroactively_start_dependencies(Unit *u) {
 579         Iterator i;
 580         Unit *other;
 581
 582         assert(u);
 583         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 584
 585         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 586                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 587                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 588
 589         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 590                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 591                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 592
 593         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 594                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 595                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 596
 597         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 598                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 599                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 600
 601         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 602                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 603                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 604 }
 605
 606 static void retroactively_stop_dependencies(Unit *u) {
 607         Iterator i;
 608         Unit *other;
 609
 610         assert(u);
 611         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 612
 613         if (u->meta.recursive_stop) {
 614                 /* Pull down units need us recursively if enabled */
 615                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 616                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 617                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 618         }
 619
 620         /* Garbage collect services that might not be needed anymore, if enabled */
 621         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 622                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 623                         unit_check_uneeded(other);
 624         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 625                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 626                         unit_check_uneeded(other);
 627         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 628                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 629                         unit_check_uneeded(other);
 630         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 631                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 632                         unit_check_uneeded(other);
 633         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUISITE], i)
 634                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 635                         unit_check_uneeded(other);
 636 }
 637
 638 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 639         assert(u);
 640         assert(os < _UNIT_ACTIVE_STATE_MAX);
 641         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 642         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 643         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 644
 645         if (os == ns)
 646                 return;
 647
 648         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 649                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 650         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 651                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 652
 653         if (u->meta.job) {
 654
 655                 if (u->meta.job->state == JOB_WAITING)
 656
 657                         /* So we reached a different state for this
 658                          * job. Let's see if we can run it now if it
 659                          * failed previously due to EAGAIN. */
 660                         job_schedule_run(u->meta.job);
 661
 662                 else {
 663                         assert(u->meta.job->state == JOB_RUNNING);
 664
 665                         /* Let's check whether this state change
 666                          * constitutes a finished job, or maybe
 667                          * cotradicts a running job and hence needs to
 668                          * invalidate jobs. */
 669
 670                         switch (u->meta.job->type) {
 671
 672                         case JOB_START:
 673                         case JOB_VERIFY_ACTIVE:
 674
 675                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 676                                         job_finish_and_invalidate(u->meta.job, true);
 677                                         return;
 678                                 } else if (ns == UNIT_ACTIVATING)
 679                                         return;
 680                                 else
 681                                         job_finish_and_invalidate(u->meta.job, false);
 682
 683                                 break;
 684
 685                         case JOB_RELOAD:
 686                         case JOB_RELOAD_OR_START:
 687
 688                                 if (ns == UNIT_ACTIVE) {
 689                                         job_finish_and_invalidate(u->meta.job, true);
 690                                         return;
 691                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 692                                         return;
 693                                 else
 694                                         job_finish_and_invalidate(u->meta.job, false);
 695
 696                                 break;
 697
 698                         case JOB_STOP:
 699                         case JOB_RESTART:
 700                         case JOB_TRY_RESTART:
 701
 702                                 if (ns == UNIT_INACTIVE) {
 703                                         job_finish_and_invalidate(u->meta.job, true);
 704                                         return;
 705                                 } else if (ns == UNIT_DEACTIVATING)
 706                                         return;
 707                                 else
 708                                         job_finish_and_invalidate(u->meta.job, false);
 709
 710                                 break;
 711
 712                         default:
 713                                 assert_not_reached("Job type unknown");
 714                         }
 715                 }
 716         }
 717
 718         /* If this state change happened without being requested by a
 719          * job, then let's retroactively start or stop dependencies */
 720
 721         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 722                 retroactively_start_dependencies(u);
 723         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 724                 retroactively_stop_dependencies(u);
 725
 726         /* Maybe we finished startup and are now ready for being
 727          * stopped because unneeded? */
 728         unit_check_uneeded(u);
 729 }
 730
 731 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 732         struct epoll_event ev;
 733
 734         assert(u);
 735         assert(fd >= 0);
 736         assert(w);
 737         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->unit == u));
 738
 739         zero(ev);
 740         ev.data.ptr = w;
 741         ev.events = events;
 742
 743         if (epoll_ctl(u->meta.manager->epoll_fd,
 744                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 745                       fd,
 746                       &ev) < 0)
 747                 return -errno;
 748
 749         w->fd = fd;
 750         w->type = WATCH_FD;
 751         w->unit = u;
 752
 753         return 0;
 754 }
 755
 756 void unit_unwatch_fd(Unit *u, Watch *w) {
 757         assert(u);
 758         assert(w);
 759
 760         if (w->type == WATCH_INVALID)
 761                 return;
 762
 763         assert(w->type == WATCH_FD && w->unit == u);
 764         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 765
 766         w->fd = -1;
 767         w->type = WATCH_INVALID;
 768         w->unit = NULL;
 769 }
 770
 771 int unit_watch_pid(Unit *u, pid_t pid) {
 772         assert(u);
 773         assert(pid >= 1);
 774
 775         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 776 }
 777
 778 void unit_unwatch_pid(Unit *u, pid_t pid) {
 779         assert(u);
 780         assert(pid >= 1);
 781
 782         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 783 }
 784
 785 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 786         struct itimerspec its;
 787         int flags, fd;
 788         bool ours;
 789
 790         assert(u);
 791         assert(w);
 792         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->unit == u));
 793
 794         /* This will try to reuse the old timer if there is one */
 795
 796         if (w->type == WATCH_TIMER) {
 797                 ours = false;
 798                 fd = w->fd;
 799         } else {
 800                 ours = true;
 801                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 802                         return -errno;
 803         }
 804
 805         zero(its);
 806
 807         if (delay <= 0) {
 808                 /* Set absolute time in the past, but not 0, since we
 809                  * don't want to disarm the timer */
 810                 its.it_value.tv_sec = 0;
 811                 its.it_value.tv_nsec = 1;
 812
 813                 flags = TFD_TIMER_ABSTIME;
 814         } else {
 815                 timespec_store(&its.it_value, delay);
 816                 flags = 0;
 817         }
 818
 819         /* This will also flush the elapse counter */
 820         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 821                 goto fail;
 822
 823         if (w->type == WATCH_INVALID) {
 824                 struct epoll_event ev;
 825
 826                 zero(ev);
 827                 ev.data.ptr = w;
 828                 ev.events = EPOLLIN;
 829
 830                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 831                         goto fail;
 832         }
 833
 834         w->fd = fd;
 835         w->type = WATCH_TIMER;
 836         w->unit = u;
 837
 838         return 0;
 839
 840 fail:
 841         if (ours)
 842                 assert_se(close_nointr(fd) == 0);
 843
 844         return -errno;
 845 }
 846
 847 void unit_unwatch_timer(Unit *u, Watch *w) {
 848         assert(u);
 849         assert(w);
 850
 851         if (w->type == WATCH_INVALID)
 852                 return;
 853
 854         assert(w->type == WATCH_TIMER && w->unit == u);
 855
 856         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 857         assert_se(close_nointr(w->fd) == 0);
 858
 859         w->fd = -1;
 860         w->type = WATCH_INVALID;
 861         w->unit = NULL;
 862 }
 863
 864 bool unit_job_is_applicable(Unit *u, JobType j) {
 865         assert(u);
 866         assert(j >= 0 && j < _JOB_TYPE_MAX);
 867
 868         switch (j) {
 869
 870         case JOB_VERIFY_ACTIVE:
 871         case JOB_START:
 872                 return true;
 873
 874         case JOB_STOP:
 875         case JOB_RESTART:
 876         case JOB_TRY_RESTART:
 877                 return unit_can_start(u);
 878
 879         case JOB_RELOAD:
 880                 return unit_can_reload(u);
 881
 882         case JOB_RELOAD_OR_START:
 883                 return unit_can_reload(u) && unit_can_start(u);
 884
 885         default:
 886                 assert_not_reached("Invalid job type");
 887         }
 888 }
 889
 890 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 891
 892         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 893                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 894                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 895                 [UNIT_WANTS] = UNIT_WANTED_BY,
 896                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 897                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 898                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 899                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 900                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 901                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 902                 [UNIT_BEFORE] = UNIT_AFTER,
 903                 [UNIT_AFTER] = UNIT_BEFORE
 904         };
 905         int r;
 906
 907         assert(u);
 908         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 909         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 910         assert(other);
 911
 912         /* We won't allow dependencies on ourselves. We will not
 913          * consider them an error however. */
 914         if (u == other)
 915                 return 0;
 916
 917         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 918                 return r;
 919
 920         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 921                 return r;
 922
 923         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 924                 return r;
 925
 926         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 927                 set_remove(u->meta.dependencies[d], other);
 928                 return r;
 929         }
 930
 931         return 0;
 932 }
 933
 934 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 935         Unit *other;
 936         int r;
 937
 938         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 939                 return r;
 940
 941         if ((r = unit_add_dependency(u, d, other)) < 0)
 942                 return r;
 943
 944         return 0;
 945 }
 946
 947 const char *unit_path(void) {
 948         char *e;
 949
 950         if ((e = getenv("UNIT_PATH")))
 951                 if (path_is_absolute(e))
 952                     return e;
 953
 954         return UNIT_PATH;
 955 }
 956
 957 int set_unit_path(const char *p) {
 958         char *cwd, *c;
 959         int r;
 960
 961         /* This is mostly for debug purposes */
 962
 963         if (path_is_absolute(p)) {
 964                 if (!(c = strdup(p)))
 965                         return -ENOMEM;
 966         } else {
 967                 if (!(cwd = get_current_dir_name()))
 968                         return -errno;
 969
 970                 r = asprintf(&c, "%s/%s", cwd, p);
 971                 free(cwd);
 972
 973                 if (r < 0)
 974                         return -ENOMEM;
 975         }
 976
 977         if (setenv("UNIT_PATH", c, 0) < 0) {
 978                 r = -errno;
 979                 free(c);
 980                 return r;
 981         }
 982
 983         return 0;
 984 }
 985
 986 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
 987         char *r, *t;
 988         const char *f;
 989         size_t a, b, c;
 990
 991         assert(path);
 992
 993         /* Takes a path and a suffix and prefix and makes a nice
 994          * string suitable as unit name of it, escaping all weird
 995          * chars on the way.
 996          *
 997          * / becomes ., and all chars not alloweed in a unit name get
 998          * escaped as \xFF, including \ and ., of course. This
 999          * escaping is hence reversible.
1000          */
1001
1002         if (!prefix)
1003                 prefix = "";
1004
1005         if (!suffix)
1006                 suffix = "";
1007
1008         a = strlen(prefix);
1009         b = strlen(path);
1010         c = strlen(suffix);
1011
1012         if (!(r = new(char, a+b*4+c+1)))
1013                 return NULL;
1014
1015         memcpy(r, prefix, a);
1016
1017         for (f = path, t = r+a; *f; f++) {
1018                 if (*f == '/')
1019                         *(t++) = '.';
1020                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
1021                         *(t++) = '\\';
1022                         *(t++) = 'x';
1023                         *(t++) = hexchar(*f > 4);
1024                         *(t++) = hexchar(*f);
1025                 } else
1026                         *(t++) = *f;
1027         }
1028
1029         memcpy(t, suffix, c+1);
1030
1031         return r;
1032 }