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         u->meta.type = t;
 151
 152         if (!u->meta.id)
 153                 u->meta.id = s;
 154
 155         return 0;
 156 }
 157
 158 int unit_choose_id(Unit *u, const char *name) {
 159         char *s;
 160
 161         assert(u);
 162         assert(name);
 163
 164         /* Selects one of the names of this unit as the id */
 165
 166         if (!(s = set_get(u->meta.names, (char*) name)))
 167                 return -ENOENT;
 168
 169         u->meta.id = s;
 170         return 0;
 171 }
 172
 173 void unit_add_to_load_queue(Unit *u) {
 174         assert(u);
 175
 176         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 177                 return;
 178
 179         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 180         u->meta.in_load_queue = true;
 181 }
 182
 183 static void bidi_set_free(Unit *u, Set *s) {
 184         Iterator i;
 185         Unit *other;
 186
 187         assert(u);
 188
 189         /* Frees the set and makes sure we are dropped from the
 190          * inverse pointers */
 191
 192         SET_FOREACH(other, s, i) {
 193                 UnitDependency d;
 194
 195                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 196                         set_remove(other->meta.dependencies[d], u);
 197         }
 198
 199         set_free(s);
 200 }
 201
 202 void unit_free(Unit *u) {
 203         UnitDependency d;
 204         Iterator i;
 205         char *t;
 206
 207         assert(u);
 208
 209         /* Detach from next 'bigger' objects */
 210
 211         SET_FOREACH(t, u->meta.names, i)
 212                 hashmap_remove_value(u->meta.manager->units, t, u);
 213
 214         if (u->meta.in_load_queue)
 215                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 216
 217         if (u->meta.load_state == UNIT_LOADED)
 218                 if (UNIT_VTABLE(u)->done)
 219                         UNIT_VTABLE(u)->done(u);
 220
 221         /* Free data and next 'smaller' objects */
 222         if (u->meta.job)
 223                 job_free(u->meta.job);
 224
 225         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 226                 bidi_set_free(u, u->meta.dependencies[d]);
 227
 228         free(u->meta.description);
 229         free(u->meta.load_path);
 230
 231         while ((t = set_steal_first(u->meta.names)))
 232                 free(t);
 233         set_free(u->meta.names);
 234
 235         free(u);
 236 }
 237
 238 UnitActiveState unit_active_state(Unit *u) {
 239         assert(u);
 240
 241         if (u->meta.load_state != UNIT_LOADED)
 242                 return UNIT_INACTIVE;
 243
 244         return UNIT_VTABLE(u)->active_state(u);
 245 }
 246
 247 static int ensure_merge(Set **s, Set *other) {
 248
 249         if (!other)
 250                 return 0;
 251
 252         if (*s)
 253                 return set_merge(*s, other);
 254
 255         if (!(*s = set_copy(other)))
 256                 return -ENOMEM;
 257
 258         return 0;
 259 }
 260
 261 /* FIXME: Does not rollback on failure! Needs to fix special unit
 262  * pointers. Needs to merge names and dependencies properly.*/
 263 int unit_merge(Unit *u, Unit *other) {
 264         int r;
 265         UnitDependency d;
 266
 267         assert(u);
 268         assert(other);
 269         assert(u->meta.manager == other->meta.manager);
 270
 271         /* This merges 'other' into 'unit'. FIXME: This does not
 272          * rollback on failure. */
 273
 274         if (u->meta.type != u->meta.type)
 275                 return -EINVAL;
 276
 277         if (u->meta.load_state != UNIT_STUB)
 278                 return -EINVAL;
 279
 280         /* Merge names */
 281         if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0)
 282                 return r;
 283
 284         /* Merge dependencies */
 285         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 286                 /* fixme, the inverse mapping is missing */
 287                 if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0)
 288                         return r;
 289
 290         return 0;
 291 }
 292
 293 const char* unit_id(Unit *u) {
 294         assert(u);
 295
 296         if (u->meta.id)
 297                 return u->meta.id;
 298
 299         return set_first(u->meta.names);
 300 }
 301
 302 const char *unit_description(Unit *u) {
 303         assert(u);
 304
 305         if (u->meta.description)
 306                 return u->meta.description;
 307
 308         return unit_id(u);
 309 }
 310
 311 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 312
 313         static const char* const load_state_table[_UNIT_LOAD_STATE_MAX] = {
 314                 [UNIT_STUB] = "stub",
 315                 [UNIT_LOADED] = "loaded",
 316                 [UNIT_FAILED] = "failed"
 317         };
 318
 319         static const char* const active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
 320                 [UNIT_ACTIVE] = "active",
 321                 [UNIT_INACTIVE] = "inactive",
 322                 [UNIT_ACTIVATING] = "activating",
 323                 [UNIT_DEACTIVATING] = "deactivating"
 324         };
 325
 326         static const char* const dependency_table[_UNIT_DEPENDENCY_MAX] = {
 327                 [UNIT_REQUIRES] = "Requires",
 328                 [UNIT_SOFT_REQUIRES] = "SoftRequires",
 329                 [UNIT_WANTS] = "Wants",
 330                 [UNIT_REQUISITE] = "Requisite",
 331                 [UNIT_SOFT_REQUISITE] = "SoftRequisite",
 332                 [UNIT_REQUIRED_BY] = "RequiredBy",
 333                 [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
 334                 [UNIT_WANTED_BY] = "WantedBy",
 335                 [UNIT_CONFLICTS] = "Conflicts",
 336                 [UNIT_BEFORE] = "Before",
 337                 [UNIT_AFTER] = "After",
 338         };
 339
 340         char *t;
 341         UnitDependency d;
 342         Iterator i;
 343         char *prefix2;
 344
 345         assert(u);
 346
 347         if (!prefix)
 348                 prefix = "";
 349         prefix2 = strappend(prefix, "\t");
 350         if (!prefix2)
 351                 prefix2 = "";
 352
 353         fprintf(f,
 354                 "%s→ Unit %s:\n"
 355                 "%s\tDescription: %s\n"
 356                 "%s\tUnit Load State: %s\n"
 357                 "%s\tUnit Active State: %s\n",
 358                 prefix, unit_id(u),
 359                 prefix, unit_description(u),
 360                 prefix, load_state_table[u->meta.load_state],
 361                 prefix, active_state_table[unit_active_state(u)]);
 362
 363         if (u->meta.load_path)
 364                 fprintf(f, "%s\tLoad Path: %s\n", prefix, u->meta.load_path);
 365
 366         SET_FOREACH(t, u->meta.names, i)
 367                 fprintf(f, "%s\tName: %s\n", prefix, t);
 368
 369         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 370                 Unit *other;
 371
 372                 if (set_isempty(u->meta.dependencies[d]))
 373                         continue;
 374
 375                 SET_FOREACH(other, u->meta.dependencies[d], i)
 376                         fprintf(f, "%s\t%s: %s\n", prefix, dependency_table[d], unit_id(other));
 377         }
 378
 379         if (UNIT_VTABLE(u)->dump)
 380                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 381
 382         if (u->meta.job)
 383                 job_dump(u->meta.job, f, prefix2);
 384
 385         free(prefix2);
 386 }
 387
 388 /* Common implementation for multiple backends */
 389 int unit_load_fragment_and_dropin(Unit *u) {
 390         int r, ret;
 391
 392         assert(u);
 393
 394         /* Load a .socket file */
 395         if ((r = unit_load_fragment(u)) < 0)
 396                 return r;
 397
 398         ret = r > 0;
 399
 400         /* Load drop-in directory data */
 401         if ((r = unit_load_dropin(u)) < 0)
 402                 return r;
 403
 404         return ret;
 405 }
 406
 407 int unit_load(Unit *u) {
 408         int r;
 409
 410         assert(u);
 411
 412         if (u->meta.in_load_queue) {
 413                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 414                 u->meta.in_load_queue = false;
 415         }
 416
 417         if (u->meta.load_state != UNIT_STUB)
 418                 return 0;
 419
 420         if (UNIT_VTABLE(u)->init)
 421                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 422                         goto fail;
 423
 424         u->meta.load_state = UNIT_LOADED;
 425         return 0;
 426
 427 fail:
 428         u->meta.load_state = UNIT_FAILED;
 429         return r;
 430 }
 431
 432 /* Errors:
 433  *         -EBADR:    This unit type does not support starting.
 434  *         -EALREADY: Unit is already started.
 435  *         -EAGAIN:   An operation is already in progress. Retry later.
 436  */
 437 int unit_start(Unit *u) {
 438         UnitActiveState state;
 439
 440         assert(u);
 441
 442         if (!UNIT_VTABLE(u)->start)
 443                 return -EBADR;
 444
 445         state = unit_active_state(u);
 446         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 447                 return -EALREADY;
 448
 449         /* We don't suppress calls to ->start() here when we are
 450          * already starting, to allow this request to be used as a
 451          * "hurry up" call, for example when the unit is in some "auto
 452          * restart" state where it waits for a holdoff timer to elapse
 453          * before it will start again. */
 454
 455         return UNIT_VTABLE(u)->start(u);
 456 }
 457
 458 bool unit_can_start(Unit *u) {
 459         assert(u);
 460
 461         return !!UNIT_VTABLE(u)->start;
 462 }
 463
 464 /* Errors:
 465  *         -EBADR:    This unit type does not support stopping.
 466  *         -EALREADY: Unit is already stopped.
 467  *         -EAGAIN:   An operation is already in progress. Retry later.
 468  */
 469 int unit_stop(Unit *u) {
 470         UnitActiveState state;
 471
 472         assert(u);
 473
 474         if (!UNIT_VTABLE(u)->stop)
 475                 return -EBADR;
 476
 477         state = unit_active_state(u);
 478         if (state == UNIT_INACTIVE)
 479                 return -EALREADY;
 480
 481         if (state == UNIT_DEACTIVATING)
 482                 return 0;
 483
 484         return UNIT_VTABLE(u)->stop(u);
 485 }
 486
 487 /* Errors:
 488  *         -EBADR:    This unit type does not support reloading.
 489  *         -ENOEXEC:  Unit is not started.
 490  *         -EAGAIN:   An operation is already in progress. Retry later.
 491  */
 492 int unit_reload(Unit *u) {
 493         UnitActiveState state;
 494
 495         assert(u);
 496
 497         if (!unit_can_reload(u))
 498                 return -EBADR;
 499
 500         state = unit_active_state(u);
 501         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 502                 return -EALREADY;
 503
 504         if (unit_active_state(u) != UNIT_ACTIVE)
 505                 return -ENOEXEC;
 506
 507         return UNIT_VTABLE(u)->reload(u);
 508 }
 509
 510 bool unit_can_reload(Unit *u) {
 511         assert(u);
 512
 513         if (!UNIT_VTABLE(u)->reload)
 514                 return false;
 515
 516         if (!UNIT_VTABLE(u)->can_reload)
 517                 return true;
 518
 519         return UNIT_VTABLE(u)->can_reload(u);
 520 }
 521
 522 static void retroactively_start_dependencies(Unit *u) {
 523         Iterator i;
 524         Unit *other;
 525
 526         assert(u);
 527         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 528
 529         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 530                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 531                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 532
 533         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 534                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 535                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 536
 537         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 538                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 539                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 540
 541         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 542                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 543                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 544
 545         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 546                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 547                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 548 }
 549
 550 static void retroactively_stop_dependencies(Unit *u) {
 551         Iterator i;
 552         Unit *other;
 553
 554         assert(u);
 555         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 556
 557         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 558                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 559                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 560 }
 561
 562 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 563         assert(u);
 564         assert(os < _UNIT_ACTIVE_STATE_MAX);
 565         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 566         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 567         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 568
 569         if (os == ns)
 570                 return;
 571
 572         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 573                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 574         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 575                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 576
 577         if (u->meta.job) {
 578
 579                 if (u->meta.job->state == JOB_WAITING)
 580
 581                         /* So we reached a different state for this
 582                          * job. Let's see if we can run it now if it
 583                          * failed previously due to EAGAIN. */
 584                         job_schedule_run(u->meta.job);
 585
 586                 else {
 587                         assert(u->meta.job->state == JOB_RUNNING);
 588
 589                         /* Let's check of this state change
 590                          * constitutes a finished job, or maybe
 591                          * cotradicts a running job and hence needs to
 592                          * invalidate jobs. */
 593
 594                         switch (u->meta.job->type) {
 595
 596                         case JOB_START:
 597                         case JOB_VERIFY_ACTIVE:
 598
 599                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 600                                         job_finish_and_invalidate(u->meta.job, true);
 601                                         return;
 602                                 } else if (ns == UNIT_ACTIVATING)
 603                                         return;
 604                                 else
 605                                         job_finish_and_invalidate(u->meta.job, false);
 606
 607                                 break;
 608
 609                         case JOB_RELOAD:
 610                         case JOB_RELOAD_OR_START:
 611
 612                                 if (ns == UNIT_ACTIVE) {
 613                                         job_finish_and_invalidate(u->meta.job, true);
 614                                         return;
 615                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 616                                         return;
 617                                 else
 618                                         job_finish_and_invalidate(u->meta.job, false);
 619
 620                                 break;
 621
 622                         case JOB_STOP:
 623                         case JOB_RESTART:
 624                         case JOB_TRY_RESTART:
 625
 626                                 if (ns == UNIT_INACTIVE) {
 627                                         job_finish_and_invalidate(u->meta.job, true);
 628                                         return;
 629                                 } else if (ns == UNIT_DEACTIVATING)
 630                                         return;
 631                                 else
 632                                         job_finish_and_invalidate(u->meta.job, false);
 633
 634                                 break;
 635
 636                         default:
 637                                 assert_not_reached("Job type unknown");
 638                         }
 639                 }
 640         }
 641
 642         /* If this state change happened without being requested by a
 643          * job, then let's retroactively start or stop dependencies */
 644
 645         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 646                 retroactively_start_dependencies(u);
 647         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 648                 retroactively_stop_dependencies(u);
 649 }
 650
 651 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 652         struct epoll_event ev;
 653
 654         assert(u);
 655         assert(fd >= 0);
 656         assert(w);
 657         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->unit == u));
 658
 659         zero(ev);
 660         ev.data.ptr = w;
 661         ev.events = events;
 662
 663         if (epoll_ctl(u->meta.manager->epoll_fd,
 664                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 665                       fd,
 666                       &ev) < 0)
 667                 return -errno;
 668
 669         w->fd = fd;
 670         w->type = WATCH_FD;
 671         w->unit = u;
 672
 673         return 0;
 674 }
 675
 676 void unit_unwatch_fd(Unit *u, Watch *w) {
 677         assert(u);
 678         assert(w);
 679
 680         if (w->type == WATCH_INVALID)
 681                 return;
 682
 683         assert(w->type == WATCH_FD && w->unit == u);
 684         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 685
 686         w->fd = -1;
 687         w->type = WATCH_INVALID;
 688         w->unit = NULL;
 689 }
 690
 691 int unit_watch_pid(Unit *u, pid_t pid) {
 692         assert(u);
 693         assert(pid >= 1);
 694
 695         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 696 }
 697
 698 void unit_unwatch_pid(Unit *u, pid_t pid) {
 699         assert(u);
 700         assert(pid >= 1);
 701
 702         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 703 }
 704
 705 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 706         struct itimerspec its;
 707         int flags, fd;
 708         bool ours;
 709
 710         assert(u);
 711         assert(w);
 712         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->unit == u));
 713
 714         /* This will try to reuse the old timer if there is one */
 715
 716         if (w->type == WATCH_TIMER) {
 717                 ours = false;
 718                 fd = w->fd;
 719         } else {
 720                 ours = true;
 721                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 722                         return -errno;
 723         }
 724
 725         zero(its);
 726
 727         if (delay <= 0) {
 728                 /* Set absolute time in the past, but not 0, since we
 729                  * don't want to disarm the timer */
 730                 its.it_value.tv_sec = 0;
 731                 its.it_value.tv_nsec = 1;
 732
 733                 flags = TFD_TIMER_ABSTIME;
 734         } else {
 735                 timespec_store(&its.it_value, delay);
 736                 flags = 0;
 737         }
 738
 739         /* This will also flush the elapse counter */
 740         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 741                 goto fail;
 742
 743         if (w->type == WATCH_INVALID) {
 744                 struct epoll_event ev;
 745
 746                 zero(ev);
 747                 ev.data.ptr = w;
 748                 ev.events = POLLIN;
 749
 750                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 751                         goto fail;
 752         }
 753
 754         w->fd = fd;
 755         w->type = WATCH_TIMER;
 756         w->unit = u;
 757
 758         return 0;
 759
 760 fail:
 761         if (ours)
 762                 assert_se(close_nointr(fd) == 0);
 763
 764         return -errno;
 765 }
 766
 767 void unit_unwatch_timer(Unit *u, Watch *w) {
 768         assert(u);
 769         assert(w);
 770
 771         if (w->type == WATCH_INVALID)
 772                 return;
 773
 774         assert(w->type == WATCH_TIMER && w->unit == u);
 775
 776         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 777         assert_se(close_nointr(w->fd) == 0);
 778
 779         w->fd = -1;
 780         w->type = WATCH_INVALID;
 781         w->unit = NULL;
 782 }
 783
 784 bool unit_job_is_applicable(Unit *u, JobType j) {
 785         assert(u);
 786         assert(j >= 0 && j < _JOB_TYPE_MAX);
 787
 788         switch (j) {
 789
 790         case JOB_VERIFY_ACTIVE:
 791         case JOB_START:
 792                 return true;
 793
 794         case JOB_STOP:
 795         case JOB_RESTART:
 796         case JOB_TRY_RESTART:
 797                 return unit_can_start(u);
 798
 799         case JOB_RELOAD:
 800                 return unit_can_reload(u);
 801
 802         case JOB_RELOAD_OR_START:
 803                 return unit_can_reload(u) && unit_can_start(u);
 804
 805         default:
 806                 assert_not_reached("Invalid job type");
 807         }
 808 }
 809
 810 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 811
 812         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 813                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 814                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 815                 [UNIT_WANTS] = UNIT_WANTED_BY,
 816                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 817                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 818                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 819                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 820                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 821                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 822                 [UNIT_BEFORE] = UNIT_AFTER,
 823                 [UNIT_AFTER] = UNIT_BEFORE
 824         };
 825         int r;
 826
 827         assert(u);
 828         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 829         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 830         assert(other);
 831
 832         /* We won't allow dependencies on ourselves. We will not
 833          * consider them an error however. */
 834         if (u == other)
 835                 return 0;
 836
 837         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 838                 return r;
 839
 840         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 841                 return r;
 842
 843         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 844                 return r;
 845
 846         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 847                 set_remove(u->meta.dependencies[d], other);
 848                 return r;
 849         }
 850
 851         return 0;
 852 }
 853
 854 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 855         Unit *other;
 856         int r;
 857
 858         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 859                 return r;
 860
 861         if ((r = unit_add_dependency(u, d, other)) < 0)
 862                 return r;
 863
 864         return 0;
 865 }
 866
 867 const char *unit_path(void) {
 868         char *e;
 869
 870         if ((e = getenv("UNIT_PATH")))
 871                 if (path_is_absolute(e))
 872                     return e;
 873
 874         return UNIT_PATH;
 875 }
 876
 877 int set_unit_path(const char *p) {
 878         char *cwd, *c;
 879         int r;
 880
 881         /* This is mostly for debug purposes */
 882
 883         if (path_is_absolute(p)) {
 884                 if (!(c = strdup(p)))
 885                         return -ENOMEM;
 886         } else {
 887                 if (!(cwd = get_current_dir_name()))
 888                         return -errno;
 889
 890                 r = asprintf(&c, "%s/%s", cwd, p);
 891                 free(cwd);
 892
 893                 if (r < 0)
 894                         return -ENOMEM;
 895         }
 896
 897         if (setenv("UNIT_PATH", c, 0) < 0) {
 898                 r = -errno;
 899                 free(c);
 900                 return r;
 901         }
 902
 903         return 0;
 904 }
 905
 906 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
 907         char *r, *t;
 908         const char *f;
 909         size_t a, b, c;
 910
 911         assert(path);
 912
 913         /* Takes a path and a suffix and prefix and makes a nice
 914          * string suitable as unit name of it, escaping all weird
 915          * chars on the way.
 916          *
 917          * / becomes ., and all chars not alloweed in a unit name get
 918          * escaped as \xFF, including \ and ., of course. This
 919          * escaping is hence reversible.
 920          */
 921
 922         if (!prefix)
 923                 prefix = "";
 924
 925         if (!suffix)
 926                 suffix = "";
 927
 928         a = strlen(prefix);
 929         b = strlen(path);
 930         c = strlen(suffix);
 931
 932         if (!(r = new(char, a+b*4+c+1)))
 933                 return NULL;
 934
 935         memcpy(r, prefix, a);
 936
 937         for (f = path, t = r+a; *f; f++) {
 938                 if (*f == '/')
 939                         *(t++) = '.';
 940                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
 941                         *(t++) = '\\';
 942                         *(t++) = 'x';
 943                         *(t++) = hexchar(*f > 4);
 944                         *(t++) = hexchar(*f);
 945                 } else
 946                         *(t++) = *f;
 947         }
 948
 949         memcpy(t, suffix, c+1);
 950
 951         return r;
 952 }