unit.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/epoll.h>
  26 #include <sys/timerfd.h>
  27 #include <sys/poll.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30
  31 #include "set.h"
  32 #include "unit.h"
  33 #include "macro.h"
  34 #include "strv.h"
  35 #include "load-fragment.h"
  36 #include "load-dropin.h"
  37 #include "log.h"
  38
  39 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
  40         [UNIT_SERVICE] = &service_vtable,
  41         [UNIT_TIMER] = &timer_vtable,
  42         [UNIT_SOCKET] = &socket_vtable,
  43         [UNIT_TARGET] = &target_vtable,
  44         [UNIT_DEVICE] = &device_vtable,
  45         [UNIT_MOUNT] = &mount_vtable,
  46         [UNIT_AUTOMOUNT] = &automount_vtable,
  47         [UNIT_SNAPSHOT] = &snapshot_vtable
  48 };
  49
  50 UnitType unit_name_to_type(const char *n) {
  51         UnitType t;
  52
  53         assert(n);
  54
  55         for (t = 0; t < _UNIT_TYPE_MAX; t++)
  56                 if (endswith(n, unit_vtable[t]->suffix))
  57                         return t;
  58
  59         return _UNIT_TYPE_INVALID;
  60 }
  61
  62 #define VALID_CHARS                             \
  63         "0123456789"                            \
  64         "abcdefghijklmnopqrstuvwxyz"            \
  65         "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
  66         "-_.\\"
  67
  68 bool unit_name_is_valid(const char *n) {
  69         UnitType t;
  70         const char *e, *i;
  71
  72         assert(n);
  73
  74         if (strlen(n) >= UNIT_NAME_MAX)
  75                 return false;
  76
  77         t = unit_name_to_type(n);
  78         if (t < 0 || t >= _UNIT_TYPE_MAX)
  79                 return false;
  80
  81         if (!(e = strrchr(n, '.')))
  82                 return false;
  83
  84         if (e == n)
  85                 return false;
  86
  87         for (i = n; i < e; i++)
  88                 if (!strchr(VALID_CHARS, *i))
  89                         return false;
  90
  91         return true;
  92 }
  93
  94 char *unit_name_change_suffix(const char *n, const char *suffix) {
  95         char *e, *r;
  96         size_t a, b;
  97
  98         assert(n);
  99         assert(unit_name_is_valid(n));
 100         assert(suffix);
 101
 102         assert_se(e = strrchr(n, '.'));
 103         a = e - n;
 104         b = strlen(suffix);
 105
 106         if (!(r = new(char, a + b + 1)))
 107                 return NULL;
 108
 109         memcpy(r, n, a);
 110         memcpy(r+a, suffix, b+1);
 111
 112         return r;
 113 }
 114
 115 Unit *unit_new(Manager *m) {
 116         Unit *u;
 117
 118         assert(m);
 119
 120         if (!(u = new0(Unit, 1)))
 121                 return NULL;
 122
 123         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
 124                 free(u);
 125                 return NULL;
 126         }
 127
 128         u->meta.manager = m;
 129         u->meta.type = _UNIT_TYPE_INVALID;
 130
 131         return u;
 132 }
 133
 134 int unit_add_name(Unit *u, const char *text) {
 135         UnitType t;
 136         char *s;
 137         int r;
 138
 139         assert(u);
 140         assert(text);
 141
 142         if (!unit_name_is_valid(text))
 143                 return -EINVAL;
 144
 145         if ((t = unit_name_to_type(text)) == _UNIT_TYPE_INVALID)
 146                 return -EINVAL;
 147
 148         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type)
 149                 return -EINVAL;
 150
 151         if (!(s = strdup(text)))
 152                 return -ENOMEM;
 153
 154         if ((r = set_put(u->meta.names, s)) < 0) {
 155                 free(s);
 156
 157                 if (r == -EEXIST)
 158                         return 0;
 159
 160                 return r;
 161         }
 162
 163         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
 164                 set_remove(u->meta.names, s);
 165                 free(s);
 166                 return r;
 167         }
 168
 169         if (u->meta.type == _UNIT_TYPE_INVALID)
 170                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
 171
 172         u->meta.type = t;
 173
 174         if (!u->meta.id)
 175                 u->meta.id = s;
 176
 177         return 0;
 178 }
 179
 180 int unit_choose_id(Unit *u, const char *name) {
 181         char *s;
 182
 183         assert(u);
 184         assert(name);
 185
 186         /* Selects one of the names of this unit as the id */
 187
 188         if (!(s = set_get(u->meta.names, (char*) name)))
 189                 return -ENOENT;
 190
 191         u->meta.id = s;
 192         return 0;
 193 }
 194
 195 int unit_set_description(Unit *u, const char *description) {
 196         char *s;
 197
 198         assert(u);
 199
 200         if (!(s = strdup(description)))
 201                 return -ENOMEM;
 202
 203         free(u->meta.description);
 204         u->meta.description = s;
 205         return 0;
 206 }
 207
 208 void unit_add_to_load_queue(Unit *u) {
 209         assert(u);
 210
 211         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 212                 return;
 213
 214         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 215         u->meta.in_load_queue = true;
 216 }
 217
 218 static void bidi_set_free(Unit *u, Set *s) {
 219         Iterator i;
 220         Unit *other;
 221
 222         assert(u);
 223
 224         /* Frees the set and makes sure we are dropped from the
 225          * inverse pointers */
 226
 227         SET_FOREACH(other, s, i) {
 228                 UnitDependency d;
 229
 230                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 231                         set_remove(other->meta.dependencies[d], u);
 232         }
 233
 234         set_free(s);
 235 }
 236
 237 void unit_free(Unit *u) {
 238         UnitDependency d;
 239         Iterator i;
 240         char *t;
 241
 242         assert(u);
 243
 244         /* Detach from next 'bigger' objects */
 245
 246         SET_FOREACH(t, u->meta.names, i)
 247                 hashmap_remove_value(u->meta.manager->units, t, u);
 248
 249         if (u->meta.type != _UNIT_TYPE_INVALID)
 250                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 251
 252         if (u->meta.in_load_queue)
 253                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 254
 255         if (u->meta.load_state == UNIT_LOADED)
 256                 if (UNIT_VTABLE(u)->done)
 257                         UNIT_VTABLE(u)->done(u);
 258
 259         /* Free data and next 'smaller' objects */
 260         if (u->meta.job)
 261                 job_free(u->meta.job);
 262
 263         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 264                 bidi_set_free(u, u->meta.dependencies[d]);
 265
 266         free(u->meta.description);
 267         free(u->meta.load_path);
 268
 269         while ((t = set_steal_first(u->meta.names)))
 270                 free(t);
 271         set_free(u->meta.names);
 272
 273         free(u);
 274 }
 275
 276 UnitActiveState unit_active_state(Unit *u) {
 277         assert(u);
 278
 279         if (u->meta.load_state != UNIT_LOADED)
 280                 return UNIT_INACTIVE;
 281
 282         return UNIT_VTABLE(u)->active_state(u);
 283 }
 284
 285 static int ensure_merge(Set **s, Set *other) {
 286
 287         if (!other)
 288                 return 0;
 289
 290         if (*s)
 291                 return set_merge(*s, other);
 292
 293         if (!(*s = set_copy(other)))
 294                 return -ENOMEM;
 295
 296         return 0;
 297 }
 298
 299 /* FIXME: Does not rollback on failure! Needs to fix special unit
 300  * pointers. Needs to merge names and dependencies properly.*/
 301 int unit_merge(Unit *u, Unit *other) {
 302         int r;
 303         UnitDependency d;
 304
 305         assert(u);
 306         assert(other);
 307         assert(u->meta.manager == other->meta.manager);
 308
 309         /* This merges 'other' into 'unit'. FIXME: This does not
 310          * rollback on failure. */
 311
 312         if (u->meta.type != u->meta.type)
 313                 return -EINVAL;
 314
 315         if (u->meta.load_state != UNIT_STUB)
 316                 return -EINVAL;
 317
 318         /* Merge names */
 319         if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0)
 320                 return r;
 321
 322         /* Merge dependencies */
 323         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 324                 /* fixme, the inverse mapping is missing */
 325                 if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0)
 326                         return r;
 327
 328         return 0;
 329 }
 330
 331 const char* unit_id(Unit *u) {
 332         assert(u);
 333
 334         if (u->meta.id)
 335                 return u->meta.id;
 336
 337         return set_first(u->meta.names);
 338 }
 339
 340 const char *unit_description(Unit *u) {
 341         assert(u);
 342
 343         if (u->meta.description)
 344                 return u->meta.description;
 345
 346         return unit_id(u);
 347 }
 348
 349 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 350
 351         char *t;
 352         UnitDependency d;
 353         Iterator i;
 354         char *prefix2;
 355
 356         assert(u);
 357
 358         if (!prefix)
 359                 prefix = "";
 360         prefix2 = strappend(prefix, "\t");
 361         if (!prefix2)
 362                 prefix2 = "";
 363
 364         fprintf(f,
 365                 "%s→ Unit %s:\n"
 366                 "%s\tDescription: %s\n"
 367                 "%s\tUnit Load State: %s\n"
 368                 "%s\tUnit Active State: %s\n"
 369                 "%s\tRecursive Stop: %s\n"
 370                 "%s\tStop When Unneeded: %s\n",
 371                 prefix, unit_id(u),
 372                 prefix, unit_description(u),
 373                 prefix, unit_load_state_to_string(u->meta.load_state),
 374                 prefix, unit_active_state_to_string(unit_active_state(u)),
 375                 prefix, yes_no(u->meta.recursive_stop),
 376                 prefix, yes_no(u->meta.stop_when_unneeded));
 377
 378         if (u->meta.load_path)
 379                 fprintf(f, "%s\tLoad Path: %s\n", prefix, u->meta.load_path);
 380
 381         SET_FOREACH(t, u->meta.names, i)
 382                 fprintf(f, "%s\tName: %s\n", prefix, t);
 383
 384         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 385                 Unit *other;
 386
 387                 if (set_isempty(u->meta.dependencies[d]))
 388                         continue;
 389
 390                 SET_FOREACH(other, u->meta.dependencies[d], i)
 391                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), unit_id(other));
 392         }
 393
 394         if (UNIT_VTABLE(u)->dump)
 395                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 396
 397         if (u->meta.job)
 398                 job_dump(u->meta.job, f, prefix2);
 399
 400         free(prefix2);
 401 }
 402
 403 /* Common implementation for multiple backends */
 404 int unit_load_fragment_and_dropin(Unit *u) {
 405         int r, ret;
 406
 407         assert(u);
 408
 409         /* Load a .socket file */
 410         if ((r = unit_load_fragment(u)) < 0)
 411                 return r;
 412
 413         ret = r > 0;
 414
 415         /* Load drop-in directory data */
 416         if ((r = unit_load_dropin(u)) < 0)
 417                 return r;
 418
 419         return ret;
 420 }
 421
 422 int unit_load(Unit *u) {
 423         int r;
 424
 425         assert(u);
 426
 427         if (u->meta.in_load_queue) {
 428                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 429                 u->meta.in_load_queue = false;
 430         }
 431
 432         if (u->meta.load_state != UNIT_STUB)
 433                 return 0;
 434
 435         if (UNIT_VTABLE(u)->init)
 436                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 437                         goto fail;
 438
 439         u->meta.load_state = UNIT_LOADED;
 440         return 0;
 441
 442 fail:
 443         u->meta.load_state = UNIT_FAILED;
 444         return r;
 445 }
 446
 447 /* Errors:
 448  *         -EBADR:    This unit type does not support starting.
 449  *         -EALREADY: Unit is already started.
 450  *         -EAGAIN:   An operation is already in progress. Retry later.
 451  */
 452 int unit_start(Unit *u) {
 453         UnitActiveState state;
 454
 455         assert(u);
 456
 457         if (!UNIT_VTABLE(u)->start)
 458                 return -EBADR;
 459
 460         state = unit_active_state(u);
 461         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 462                 return -EALREADY;
 463
 464         /* We don't suppress calls to ->start() here when we are
 465          * already starting, to allow this request to be used as a
 466          * "hurry up" call, for example when the unit is in some "auto
 467          * restart" state where it waits for a holdoff timer to elapse
 468          * before it will start again. */
 469
 470         return UNIT_VTABLE(u)->start(u);
 471 }
 472
 473 bool unit_can_start(Unit *u) {
 474         assert(u);
 475
 476         return !!UNIT_VTABLE(u)->start;
 477 }
 478
 479 /* Errors:
 480  *         -EBADR:    This unit type does not support stopping.
 481  *         -EALREADY: Unit is already stopped.
 482  *         -EAGAIN:   An operation is already in progress. Retry later.
 483  */
 484 int unit_stop(Unit *u) {
 485         UnitActiveState state;
 486
 487         assert(u);
 488
 489         if (!UNIT_VTABLE(u)->stop)
 490                 return -EBADR;
 491
 492         state = unit_active_state(u);
 493         if (state == UNIT_INACTIVE)
 494                 return -EALREADY;
 495
 496         if (state == UNIT_DEACTIVATING)
 497                 return 0;
 498
 499         return UNIT_VTABLE(u)->stop(u);
 500 }
 501
 502 /* Errors:
 503  *         -EBADR:    This unit type does not support reloading.
 504  *         -ENOEXEC:  Unit is not started.
 505  *         -EAGAIN:   An operation is already in progress. Retry later.
 506  */
 507 int unit_reload(Unit *u) {
 508         UnitActiveState state;
 509
 510         assert(u);
 511
 512         if (!unit_can_reload(u))
 513                 return -EBADR;
 514
 515         state = unit_active_state(u);
 516         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 517                 return -EALREADY;
 518
 519         if (unit_active_state(u) != UNIT_ACTIVE)
 520                 return -ENOEXEC;
 521
 522         return UNIT_VTABLE(u)->reload(u);
 523 }
 524
 525 bool unit_can_reload(Unit *u) {
 526         assert(u);
 527
 528         if (!UNIT_VTABLE(u)->reload)
 529                 return false;
 530
 531         if (!UNIT_VTABLE(u)->can_reload)
 532                 return true;
 533
 534         return UNIT_VTABLE(u)->can_reload(u);
 535 }
 536
 537 static void unit_check_uneeded(Unit *u) {
 538         Iterator i;
 539         Unit *other;
 540
 541         assert(u);
 542
 543         /* If this service shall be shut down when unneeded then do
 544          * so. */
 545
 546         if (!u->meta.stop_when_unneeded)
 547                 return;
 548
 549         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 550                 return;
 551
 552         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 553                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 554                         return;
 555
 556         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 557                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 558                         return;
 559
 560         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 561                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 562                         return;
 563
 564         log_debug("Service %s is not needed anymore. Stopping.", unit_id(u));
 565
 566         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 567         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 568 }
 569
 570 static void retroactively_start_dependencies(Unit *u) {
 571         Iterator i;
 572         Unit *other;
 573
 574         assert(u);
 575         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 576
 577         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 578                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 579                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 580
 581         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 582                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 583                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 584
 585         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], 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_WANTS], 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_CONFLICTS], i)
 594                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 595                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 596 }
 597
 598 static void retroactively_stop_dependencies(Unit *u) {
 599         Iterator i;
 600         Unit *other;
 601
 602         assert(u);
 603         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 604
 605         if (u->meta.recursive_stop) {
 606                 /* Pull down units need us recursively if enabled */
 607                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 608                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 609                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 610         }
 611
 612         /* Garbage collect services that might not be needed anymore, if enabled */
 613         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 614                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 615                         unit_check_uneeded(other);
 616         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 617                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 618                         unit_check_uneeded(other);
 619         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 620                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 621                         unit_check_uneeded(other);
 622         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 623                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 624                         unit_check_uneeded(other);
 625         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUISITE], i)
 626                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 627                         unit_check_uneeded(other);
 628 }
 629
 630 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 631         assert(u);
 632         assert(os < _UNIT_ACTIVE_STATE_MAX);
 633         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 634         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 635         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 636
 637         if (os == ns)
 638                 return;
 639
 640         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 641                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 642         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 643                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 644
 645         if (u->meta.job) {
 646
 647                 if (u->meta.job->state == JOB_WAITING)
 648
 649                         /* So we reached a different state for this
 650                          * job. Let's see if we can run it now if it
 651                          * failed previously due to EAGAIN. */
 652                         job_schedule_run(u->meta.job);
 653
 654                 else {
 655                         assert(u->meta.job->state == JOB_RUNNING);
 656
 657                         /* Let's check whether this state change
 658                          * constitutes a finished job, or maybe
 659                          * cotradicts a running job and hence needs to
 660                          * invalidate jobs. */
 661
 662                         switch (u->meta.job->type) {
 663
 664                         case JOB_START:
 665                         case JOB_VERIFY_ACTIVE:
 666
 667                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 668                                         job_finish_and_invalidate(u->meta.job, true);
 669                                         return;
 670                                 } else if (ns == UNIT_ACTIVATING)
 671                                         return;
 672                                 else
 673                                         job_finish_and_invalidate(u->meta.job, false);
 674
 675                                 break;
 676
 677                         case JOB_RELOAD:
 678                         case JOB_RELOAD_OR_START:
 679
 680                                 if (ns == UNIT_ACTIVE) {
 681                                         job_finish_and_invalidate(u->meta.job, true);
 682                                         return;
 683                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 684                                         return;
 685                                 else
 686                                         job_finish_and_invalidate(u->meta.job, false);
 687
 688                                 break;
 689
 690                         case JOB_STOP:
 691                         case JOB_RESTART:
 692                         case JOB_TRY_RESTART:
 693
 694                                 if (ns == UNIT_INACTIVE) {
 695                                         job_finish_and_invalidate(u->meta.job, true);
 696                                         return;
 697                                 } else if (ns == UNIT_DEACTIVATING)
 698                                         return;
 699                                 else
 700                                         job_finish_and_invalidate(u->meta.job, false);
 701
 702                                 break;
 703
 704                         default:
 705                                 assert_not_reached("Job type unknown");
 706                         }
 707                 }
 708         }
 709
 710         /* If this state change happened without being requested by a
 711          * job, then let's retroactively start or stop dependencies */
 712
 713         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 714                 retroactively_start_dependencies(u);
 715         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 716                 retroactively_stop_dependencies(u);
 717
 718         /* Maybe we finished startup and are now ready for being
 719          * stopped because unneeded? */
 720         unit_check_uneeded(u);
 721 }
 722
 723 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 724         struct epoll_event ev;
 725
 726         assert(u);
 727         assert(fd >= 0);
 728         assert(w);
 729         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
 730
 731         zero(ev);
 732         ev.data.ptr = w;
 733         ev.events = events;
 734
 735         if (epoll_ctl(u->meta.manager->epoll_fd,
 736                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 737                       fd,
 738                       &ev) < 0)
 739                 return -errno;
 740
 741         w->fd = fd;
 742         w->type = WATCH_FD;
 743         w->data.unit = u;
 744
 745         return 0;
 746 }
 747
 748 void unit_unwatch_fd(Unit *u, Watch *w) {
 749         assert(u);
 750         assert(w);
 751
 752         if (w->type == WATCH_INVALID)
 753                 return;
 754
 755         assert(w->type == WATCH_FD);
 756         assert(w->data.unit == u);
 757         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 758
 759         w->fd = -1;
 760         w->type = WATCH_INVALID;
 761         w->data.unit = NULL;
 762 }
 763
 764 int unit_watch_pid(Unit *u, pid_t pid) {
 765         assert(u);
 766         assert(pid >= 1);
 767
 768         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 769 }
 770
 771 void unit_unwatch_pid(Unit *u, pid_t pid) {
 772         assert(u);
 773         assert(pid >= 1);
 774
 775         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 776 }
 777
 778 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 779         struct itimerspec its;
 780         int flags, fd;
 781         bool ours;
 782
 783         assert(u);
 784         assert(w);
 785         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
 786
 787         /* This will try to reuse the old timer if there is one */
 788
 789         if (w->type == WATCH_TIMER) {
 790                 ours = false;
 791                 fd = w->fd;
 792         } else {
 793                 ours = true;
 794                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 795                         return -errno;
 796         }
 797
 798         zero(its);
 799
 800         if (delay <= 0) {
 801                 /* Set absolute time in the past, but not 0, since we
 802                  * don't want to disarm the timer */
 803                 its.it_value.tv_sec = 0;
 804                 its.it_value.tv_nsec = 1;
 805
 806                 flags = TFD_TIMER_ABSTIME;
 807         } else {
 808                 timespec_store(&its.it_value, delay);
 809                 flags = 0;
 810         }
 811
 812         /* This will also flush the elapse counter */
 813         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 814                 goto fail;
 815
 816         if (w->type == WATCH_INVALID) {
 817                 struct epoll_event ev;
 818
 819                 zero(ev);
 820                 ev.data.ptr = w;
 821                 ev.events = EPOLLIN;
 822
 823                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 824                         goto fail;
 825         }
 826
 827         w->fd = fd;
 828         w->type = WATCH_TIMER;
 829         w->data.unit = u;
 830
 831         return 0;
 832
 833 fail:
 834         if (ours)
 835                 close_nointr_nofail(fd);
 836
 837         return -errno;
 838 }
 839
 840 void unit_unwatch_timer(Unit *u, Watch *w) {
 841         assert(u);
 842         assert(w);
 843
 844         if (w->type == WATCH_INVALID)
 845                 return;
 846
 847         assert(w->type == WATCH_TIMER && w->data.unit == u);
 848
 849         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 850         assert_se(close_nointr(w->fd) == 0);
 851
 852         w->fd = -1;
 853         w->type = WATCH_INVALID;
 854         w->data.unit = NULL;
 855 }
 856
 857 bool unit_job_is_applicable(Unit *u, JobType j) {
 858         assert(u);
 859         assert(j >= 0 && j < _JOB_TYPE_MAX);
 860
 861         switch (j) {
 862
 863         case JOB_VERIFY_ACTIVE:
 864         case JOB_START:
 865                 return true;
 866
 867         case JOB_STOP:
 868         case JOB_RESTART:
 869         case JOB_TRY_RESTART:
 870                 return unit_can_start(u);
 871
 872         case JOB_RELOAD:
 873                 return unit_can_reload(u);
 874
 875         case JOB_RELOAD_OR_START:
 876                 return unit_can_reload(u) && unit_can_start(u);
 877
 878         default:
 879                 assert_not_reached("Invalid job type");
 880         }
 881 }
 882
 883 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 884
 885         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 886                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 887                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 888                 [UNIT_WANTS] = UNIT_WANTED_BY,
 889                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 890                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 891                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 892                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 893                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 894                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 895                 [UNIT_BEFORE] = UNIT_AFTER,
 896                 [UNIT_AFTER] = UNIT_BEFORE
 897         };
 898         int r;
 899
 900         assert(u);
 901         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 902         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 903         assert(other);
 904
 905         /* We won't allow dependencies on ourselves. We will not
 906          * consider them an error however. */
 907         if (u == other)
 908                 return 0;
 909
 910         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 911                 return r;
 912
 913         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 914                 return r;
 915
 916         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 917                 return r;
 918
 919         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 920                 set_remove(u->meta.dependencies[d], other);
 921                 return r;
 922         }
 923
 924         return 0;
 925 }
 926
 927 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 928         Unit *other;
 929         int r;
 930
 931         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 932                 return r;
 933
 934         if ((r = unit_add_dependency(u, d, other)) < 0)
 935                 return r;
 936
 937         return 0;
 938 }
 939
 940 const char *unit_path(void) {
 941         char *e;
 942
 943         if ((e = getenv("UNIT_PATH")))
 944                 if (path_is_absolute(e))
 945                     return e;
 946
 947         return UNIT_PATH;
 948 }
 949
 950 int set_unit_path(const char *p) {
 951         char *cwd, *c;
 952         int r;
 953
 954         /* This is mostly for debug purposes */
 955
 956         if (path_is_absolute(p)) {
 957                 if (!(c = strdup(p)))
 958                         return -ENOMEM;
 959         } else {
 960                 if (!(cwd = get_current_dir_name()))
 961                         return -errno;
 962
 963                 r = asprintf(&c, "%s/%s", cwd, p);
 964                 free(cwd);
 965
 966                 if (r < 0)
 967                         return -ENOMEM;
 968         }
 969
 970         if (setenv("UNIT_PATH", c, 0) < 0) {
 971                 r = -errno;
 972                 free(c);
 973                 return r;
 974         }
 975
 976         return 0;
 977 }
 978
 979 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
 980         char *r, *t;
 981         const char *f;
 982         size_t a, b, c;
 983
 984         assert(path);
 985
 986         /* Takes a path and a suffix and prefix and makes a nice
 987          * string suitable as unit name of it, escaping all weird
 988          * chars on the way.
 989          *
 990          * / becomes ., and all chars not alloweed in a unit name get
 991          * escaped as \xFF, including \ and ., of course. This
 992          * escaping is hence reversible.
 993          */
 994
 995         if (!prefix)
 996                 prefix = "";
 997
 998         if (!suffix)
 999                 suffix = "";
1000
1001         a = strlen(prefix);
1002         b = strlen(path);
1003         c = strlen(suffix);
1004
1005         if (!(r = new(char, a+b*4+c+1)))
1006                 return NULL;
1007
1008         memcpy(r, prefix, a);
1009
1010         for (f = path, t = r+a; *f; f++) {
1011                 if (*f == '/')
1012                         *(t++) = '.';
1013                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
1014                         *(t++) = '\\';
1015                         *(t++) = 'x';
1016                         *(t++) = hexchar(*f > 4);
1017                         *(t++) = hexchar(*f);
1018                 } else
1019                         *(t++) = *f;
1020         }
1021
1022         memcpy(t, suffix, c+1);
1023
1024         return r;
1025 }
1026
1027 char *unit_dbus_path(Unit *u) {
1028         char *p, *e;
1029
1030         assert(u);
1031
1032         if (!(e = bus_path_escape(unit_id(u))))
1033                 return NULL;
1034
1035         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1036                 free(e);
1037                 return NULL;
1038         }
1039
1040         free(e);
1041         return p;
1042 }
1043
1044 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1045         [UNIT_SERVICE] = "service",
1046         [UNIT_TIMER] = "timer",
1047         [UNIT_SOCKET] = "socket",
1048         [UNIT_TARGET] = "target",
1049         [UNIT_DEVICE] = "device",
1050         [UNIT_MOUNT] = "mount",
1051         [UNIT_AUTOMOUNT] = "automount",
1052         [UNIT_SNAPSHOT] = "snapshot"
1053 };
1054
1055 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1056
1057 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1058         [UNIT_STUB] = "stub",
1059         [UNIT_LOADED] = "loaded",
1060         [UNIT_FAILED] = "failed"
1061 };
1062
1063 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1064
1065 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1066         [UNIT_ACTIVE] = "active",
1067         [UNIT_INACTIVE] = "inactive",
1068         [UNIT_ACTIVATING] = "activating",
1069         [UNIT_DEACTIVATING] = "deactivating"
1070 };
1071
1072 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1073
1074 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1075         [UNIT_REQUIRES] = "Requires",
1076         [UNIT_SOFT_REQUIRES] = "SoftRequires",
1077         [UNIT_WANTS] = "Wants",
1078         [UNIT_REQUISITE] = "Requisite",
1079         [UNIT_SOFT_REQUISITE] = "SoftRequisite",
1080         [UNIT_REQUIRED_BY] = "RequiredBy",
1081         [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
1082         [UNIT_WANTED_BY] = "WantedBy",
1083         [UNIT_CONFLICTS] = "Conflicts",
1084         [UNIT_BEFORE] = "Before",
1085         [UNIT_AFTER] = "After",
1086 };
1087
1088 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);