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