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         unit_add_to_dbus_queue(u);
 178         return 0;
 179 }
 180
 181 int unit_choose_id(Unit *u, const char *name) {
 182         char *s;
 183
 184         assert(u);
 185         assert(name);
 186
 187         /* Selects one of the names of this unit as the id */
 188
 189         if (!(s = set_get(u->meta.names, (char*) name)))
 190                 return -ENOENT;
 191
 192         u->meta.id = s;
 193
 194         unit_add_to_dbus_queue(u);
 195         return 0;
 196 }
 197
 198 int unit_set_description(Unit *u, const char *description) {
 199         char *s;
 200
 201         assert(u);
 202
 203         if (!(s = strdup(description)))
 204                 return -ENOMEM;
 205
 206         free(u->meta.description);
 207         u->meta.description = s;
 208
 209         unit_add_to_dbus_queue(u);
 210         return 0;
 211 }
 212
 213 void unit_add_to_load_queue(Unit *u) {
 214         assert(u);
 215
 216         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
 217                 return;
 218
 219         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 220         u->meta.in_load_queue = true;
 221 }
 222
 223 void unit_add_to_dbus_queue(Unit *u) {
 224         assert(u);
 225
 226         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue || set_isempty(u->meta.manager->subscribed))
 227                 return;
 228
 229         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 230         u->meta.in_dbus_queue = true;
 231 }
 232
 233 static void bidi_set_free(Unit *u, Set *s) {
 234         Iterator i;
 235         Unit *other;
 236
 237         assert(u);
 238
 239         /* Frees the set and makes sure we are dropped from the
 240          * inverse pointers */
 241
 242         SET_FOREACH(other, s, i) {
 243                 UnitDependency d;
 244
 245                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 246                         set_remove(other->meta.dependencies[d], u);
 247         }
 248
 249         set_free(s);
 250 }
 251
 252 void unit_free(Unit *u) {
 253         UnitDependency d;
 254         Iterator i;
 255         char *t;
 256
 257         assert(u);
 258
 259         bus_unit_send_removed_signal(u);
 260
 261         /* Detach from next 'bigger' objects */
 262
 263         SET_FOREACH(t, u->meta.names, i)
 264                 hashmap_remove_value(u->meta.manager->units, t, u);
 265
 266         if (u->meta.type != _UNIT_TYPE_INVALID)
 267                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
 268
 269         if (u->meta.in_load_queue)
 270                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 271
 272         if (u->meta.in_dbus_queue)
 273                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
 274
 275         if (u->meta.load_state == UNIT_LOADED)
 276                 if (UNIT_VTABLE(u)->done)
 277                         UNIT_VTABLE(u)->done(u);
 278
 279         /* Free data and next 'smaller' objects */
 280         if (u->meta.job)
 281                 job_free(u->meta.job);
 282
 283         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 284                 bidi_set_free(u, u->meta.dependencies[d]);
 285
 286         free(u->meta.description);
 287         free(u->meta.load_path);
 288
 289         while ((t = set_steal_first(u->meta.names)))
 290                 free(t);
 291         set_free(u->meta.names);
 292
 293         free(u);
 294 }
 295
 296 UnitActiveState unit_active_state(Unit *u) {
 297         assert(u);
 298
 299         if (u->meta.load_state != UNIT_LOADED)
 300                 return UNIT_INACTIVE;
 301
 302         return UNIT_VTABLE(u)->active_state(u);
 303 }
 304
 305 static int ensure_merge(Set **s, Set *other) {
 306
 307         if (!other)
 308                 return 0;
 309
 310         if (*s)
 311                 return set_merge(*s, other);
 312
 313         if (!(*s = set_copy(other)))
 314                 return -ENOMEM;
 315
 316         return 0;
 317 }
 318
 319 /* FIXME: Does not rollback on failure! Needs to fix special unit
 320  * pointers. Needs to merge names and dependencies properly.*/
 321 int unit_merge(Unit *u, Unit *other) {
 322         int r;
 323         UnitDependency d;
 324
 325         assert(u);
 326         assert(other);
 327         assert(u->meta.manager == other->meta.manager);
 328
 329         /* This merges 'other' into 'unit'. FIXME: This does not
 330          * rollback on failure. */
 331
 332         if (u->meta.type != u->meta.type)
 333                 return -EINVAL;
 334
 335         if (u->meta.load_state != UNIT_STUB)
 336                 return -EINVAL;
 337
 338         /* Merge names */
 339         if ((r = ensure_merge(&u->meta.names, other->meta.names)) < 0)
 340                 return r;
 341
 342         /* Merge dependencies */
 343         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
 344                 /* fixme, the inverse mapping is missing */
 345                 if ((r = ensure_merge(&u->meta.dependencies[d], other->meta.dependencies[d])) < 0)
 346                         return r;
 347
 348         unit_add_to_dbus_queue(u);
 349
 350         return 0;
 351 }
 352
 353 const char* unit_id(Unit *u) {
 354         assert(u);
 355
 356         if (u->meta.id)
 357                 return u->meta.id;
 358
 359         return set_first(u->meta.names);
 360 }
 361
 362 const char *unit_description(Unit *u) {
 363         assert(u);
 364
 365         if (u->meta.description)
 366                 return u->meta.description;
 367
 368         return unit_id(u);
 369 }
 370
 371 void unit_dump(Unit *u, FILE *f, const char *prefix) {
 372
 373         char *t;
 374         UnitDependency d;
 375         Iterator i;
 376         char *p2;
 377         const char *prefix2;
 378
 379         assert(u);
 380
 381         if (!prefix)
 382                 prefix = "";
 383         p2 = strappend(prefix, "\t");
 384         prefix2 = p2 ? p2 : prefix;
 385
 386         fprintf(f,
 387                 "%s→ Unit %s:\n"
 388                 "%s\tDescription: %s\n"
 389                 "%s\tUnit Load State: %s\n"
 390                 "%s\tUnit Active State: %s\n"
 391                 "%s\tRecursive Stop: %s\n"
 392                 "%s\tStop When Unneeded: %s\n",
 393                 prefix, unit_id(u),
 394                 prefix, unit_description(u),
 395                 prefix, unit_load_state_to_string(u->meta.load_state),
 396                 prefix, unit_active_state_to_string(unit_active_state(u)),
 397                 prefix, yes_no(u->meta.recursive_stop),
 398                 prefix, yes_no(u->meta.stop_when_unneeded));
 399
 400         if (u->meta.load_path)
 401                 fprintf(f, "%s\tLoad Path: %s\n", prefix, u->meta.load_path);
 402
 403         SET_FOREACH(t, u->meta.names, i)
 404                 fprintf(f, "%s\tName: %s\n", prefix, t);
 405
 406         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
 407                 Unit *other;
 408
 409                 if (set_isempty(u->meta.dependencies[d]))
 410                         continue;
 411
 412                 SET_FOREACH(other, u->meta.dependencies[d], i)
 413                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), unit_id(other));
 414         }
 415
 416         if (UNIT_VTABLE(u)->dump)
 417                 UNIT_VTABLE(u)->dump(u, f, prefix2);
 418
 419         if (u->meta.job)
 420                 job_dump(u->meta.job, f, prefix2);
 421
 422         free(p2);
 423 }
 424
 425 /* Common implementation for multiple backends */
 426 int unit_load_fragment_and_dropin(Unit *u) {
 427         int r, ret;
 428
 429         assert(u);
 430
 431         /* Load a .socket file */
 432         if ((r = unit_load_fragment(u)) < 0)
 433                 return r;
 434
 435         ret = r > 0;
 436
 437         /* Load drop-in directory data */
 438         if ((r = unit_load_dropin(u)) < 0)
 439                 return r;
 440
 441         return ret;
 442 }
 443
 444 int unit_load(Unit *u) {
 445         int r;
 446
 447         assert(u);
 448
 449         if (u->meta.in_load_queue) {
 450                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
 451                 u->meta.in_load_queue = false;
 452         }
 453
 454         if (u->meta.load_state != UNIT_STUB)
 455                 return 0;
 456
 457         if (UNIT_VTABLE(u)->init)
 458                 if ((r = UNIT_VTABLE(u)->init(u)) < 0)
 459                         goto fail;
 460
 461         u->meta.load_state = UNIT_LOADED;
 462         unit_add_to_dbus_queue(u);
 463         return 0;
 464
 465 fail:
 466         u->meta.load_state = UNIT_FAILED;
 467         unit_add_to_dbus_queue(u);
 468         return r;
 469 }
 470
 471 /* Errors:
 472  *         -EBADR:    This unit type does not support starting.
 473  *         -EALREADY: Unit is already started.
 474  *         -EAGAIN:   An operation is already in progress. Retry later.
 475  */
 476 int unit_start(Unit *u) {
 477         UnitActiveState state;
 478
 479         assert(u);
 480
 481         /* If this is already (being) started, then this will
 482          * succeed. Note that this will even succeed if this unit is
 483          * not startable by the user. This is relied on to detect when
 484          * we need to wait for units and when waiting is finished. */
 485         state = unit_active_state(u);
 486         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 487                 return -EALREADY;
 488
 489         /* If it is stopped, but we cannot start it, then fail */
 490         if (!UNIT_VTABLE(u)->start)
 491                 return -EBADR;
 492
 493         /* We don't suppress calls to ->start() here when we are
 494          * already starting, to allow this request to be used as a
 495          * "hurry up" call, for example when the unit is in some "auto
 496          * restart" state where it waits for a holdoff timer to elapse
 497          * before it will start again. */
 498
 499         unit_add_to_dbus_queue(u);
 500         return UNIT_VTABLE(u)->start(u);
 501 }
 502
 503 bool unit_can_start(Unit *u) {
 504         assert(u);
 505
 506         return !!UNIT_VTABLE(u)->start;
 507 }
 508
 509 /* Errors:
 510  *         -EBADR:    This unit type does not support stopping.
 511  *         -EALREADY: Unit is already stopped.
 512  *         -EAGAIN:   An operation is already in progress. Retry later.
 513  */
 514 int unit_stop(Unit *u) {
 515         UnitActiveState state;
 516
 517         assert(u);
 518
 519         state = unit_active_state(u);
 520         if (state == UNIT_INACTIVE)
 521                 return -EALREADY;
 522
 523         if (!UNIT_VTABLE(u)->stop)
 524                 return -EBADR;
 525
 526         if (state == UNIT_DEACTIVATING)
 527                 return 0;
 528
 529         unit_add_to_dbus_queue(u);
 530         return UNIT_VTABLE(u)->stop(u);
 531 }
 532
 533 /* Errors:
 534  *         -EBADR:    This unit type does not support reloading.
 535  *         -ENOEXEC:  Unit is not started.
 536  *         -EAGAIN:   An operation is already in progress. Retry later.
 537  */
 538 int unit_reload(Unit *u) {
 539         UnitActiveState state;
 540
 541         assert(u);
 542
 543         if (!unit_can_reload(u))
 544                 return -EBADR;
 545
 546         state = unit_active_state(u);
 547         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 548                 return -EALREADY;
 549
 550         if (unit_active_state(u) != UNIT_ACTIVE)
 551                 return -ENOEXEC;
 552
 553         unit_add_to_dbus_queue(u);
 554         return UNIT_VTABLE(u)->reload(u);
 555 }
 556
 557 bool unit_can_reload(Unit *u) {
 558         assert(u);
 559
 560         if (!UNIT_VTABLE(u)->reload)
 561                 return false;
 562
 563         if (!UNIT_VTABLE(u)->can_reload)
 564                 return true;
 565
 566         return UNIT_VTABLE(u)->can_reload(u);
 567 }
 568
 569 static void unit_check_uneeded(Unit *u) {
 570         Iterator i;
 571         Unit *other;
 572
 573         assert(u);
 574
 575         /* If this service shall be shut down when unneeded then do
 576          * so. */
 577
 578         if (!u->meta.stop_when_unneeded)
 579                 return;
 580
 581         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 582                 return;
 583
 584         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 585                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 586                         return;
 587
 588         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 589                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 590                         return;
 591
 592         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 593                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 594                         return;
 595
 596         log_debug("Service %s is not needed anymore. Stopping.", unit_id(u));
 597
 598         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 599         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 600 }
 601
 602 static void retroactively_start_dependencies(Unit *u) {
 603         Iterator i;
 604         Unit *other;
 605
 606         assert(u);
 607         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 608
 609         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 610                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 611                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 612
 613         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 614                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 615                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 616
 617         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 618                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 619                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 620
 621         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 622                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 623                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 624
 625         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 626                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 627                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 628 }
 629
 630 static void retroactively_stop_dependencies(Unit *u) {
 631         Iterator i;
 632         Unit *other;
 633
 634         assert(u);
 635         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 636
 637         if (u->meta.recursive_stop) {
 638                 /* Pull down units need us recursively if enabled */
 639                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 640                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 641                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 642         }
 643
 644         /* Garbage collect services that might not be needed anymore, if enabled */
 645         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 646                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 647                         unit_check_uneeded(other);
 648         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 649                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 650                         unit_check_uneeded(other);
 651         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 652                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 653                         unit_check_uneeded(other);
 654         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 655                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 656                         unit_check_uneeded(other);
 657         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUISITE], i)
 658                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 659                         unit_check_uneeded(other);
 660 }
 661
 662 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 663         assert(u);
 664         assert(os < _UNIT_ACTIVE_STATE_MAX);
 665         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 666         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 667         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 668
 669         if (os == ns)
 670                 return;
 671
 672         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 673                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 674         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 675                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 676
 677         if (u->meta.job) {
 678
 679                 if (u->meta.job->state == JOB_WAITING)
 680
 681                         /* So we reached a different state for this
 682                          * job. Let's see if we can run it now if it
 683                          * failed previously due to EAGAIN. */
 684                         job_add_to_run_queue(u->meta.job);
 685
 686                 else {
 687                         assert(u->meta.job->state == JOB_RUNNING);
 688
 689                         /* Let's check whether this state change
 690                          * constitutes a finished job, or maybe
 691                          * cotradicts a running job and hence needs to
 692                          * invalidate jobs. */
 693
 694                         switch (u->meta.job->type) {
 695
 696                         case JOB_START:
 697                         case JOB_VERIFY_ACTIVE:
 698
 699                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 700                                         job_finish_and_invalidate(u->meta.job, true);
 701                                         return;
 702                                 } else if (ns == UNIT_ACTIVATING)
 703                                         return;
 704                                 else
 705                                         job_finish_and_invalidate(u->meta.job, false);
 706
 707                                 break;
 708
 709                         case JOB_RELOAD:
 710                         case JOB_RELOAD_OR_START:
 711
 712                                 if (ns == UNIT_ACTIVE) {
 713                                         job_finish_and_invalidate(u->meta.job, true);
 714                                         return;
 715                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 716                                         return;
 717                                 else
 718                                         job_finish_and_invalidate(u->meta.job, false);
 719
 720                                 break;
 721
 722                         case JOB_STOP:
 723                         case JOB_RESTART:
 724                         case JOB_TRY_RESTART:
 725
 726                                 if (ns == UNIT_INACTIVE) {
 727                                         job_finish_and_invalidate(u->meta.job, true);
 728                                         return;
 729                                 } else if (ns == UNIT_DEACTIVATING)
 730                                         return;
 731                                 else
 732                                         job_finish_and_invalidate(u->meta.job, false);
 733
 734                                 break;
 735
 736                         default:
 737                                 assert_not_reached("Job type unknown");
 738                         }
 739                 }
 740         }
 741
 742         /* If this state change happened without being requested by a
 743          * job, then let's retroactively start or stop dependencies */
 744
 745         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 746                 retroactively_start_dependencies(u);
 747         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 748                 retroactively_stop_dependencies(u);
 749
 750         /* Maybe we finished startup and are now ready for being
 751          * stopped because unneeded? */
 752         unit_check_uneeded(u);
 753
 754         unit_add_to_dbus_queue(u);
 755 }
 756
 757 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 758         struct epoll_event ev;
 759
 760         assert(u);
 761         assert(fd >= 0);
 762         assert(w);
 763         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
 764
 765         zero(ev);
 766         ev.data.ptr = w;
 767         ev.events = events;
 768
 769         if (epoll_ctl(u->meta.manager->epoll_fd,
 770                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 771                       fd,
 772                       &ev) < 0)
 773                 return -errno;
 774
 775         w->fd = fd;
 776         w->type = WATCH_FD;
 777         w->data.unit = u;
 778
 779         return 0;
 780 }
 781
 782 void unit_unwatch_fd(Unit *u, Watch *w) {
 783         assert(u);
 784         assert(w);
 785
 786         if (w->type == WATCH_INVALID)
 787                 return;
 788
 789         assert(w->type == WATCH_FD);
 790         assert(w->data.unit == u);
 791         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 792
 793         w->fd = -1;
 794         w->type = WATCH_INVALID;
 795         w->data.unit = NULL;
 796 }
 797
 798 int unit_watch_pid(Unit *u, pid_t pid) {
 799         assert(u);
 800         assert(pid >= 1);
 801
 802         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 803 }
 804
 805 void unit_unwatch_pid(Unit *u, pid_t pid) {
 806         assert(u);
 807         assert(pid >= 1);
 808
 809         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 810 }
 811
 812 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 813         struct itimerspec its;
 814         int flags, fd;
 815         bool ours;
 816
 817         assert(u);
 818         assert(w);
 819         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
 820
 821         /* This will try to reuse the old timer if there is one */
 822
 823         if (w->type == WATCH_TIMER) {
 824                 ours = false;
 825                 fd = w->fd;
 826         } else {
 827                 ours = true;
 828                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 829                         return -errno;
 830         }
 831
 832         zero(its);
 833
 834         if (delay <= 0) {
 835                 /* Set absolute time in the past, but not 0, since we
 836                  * don't want to disarm the timer */
 837                 its.it_value.tv_sec = 0;
 838                 its.it_value.tv_nsec = 1;
 839
 840                 flags = TFD_TIMER_ABSTIME;
 841         } else {
 842                 timespec_store(&its.it_value, delay);
 843                 flags = 0;
 844         }
 845
 846         /* This will also flush the elapse counter */
 847         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 848                 goto fail;
 849
 850         if (w->type == WATCH_INVALID) {
 851                 struct epoll_event ev;
 852
 853                 zero(ev);
 854                 ev.data.ptr = w;
 855                 ev.events = EPOLLIN;
 856
 857                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 858                         goto fail;
 859         }
 860
 861         w->fd = fd;
 862         w->type = WATCH_TIMER;
 863         w->data.unit = u;
 864
 865         return 0;
 866
 867 fail:
 868         if (ours)
 869                 close_nointr_nofail(fd);
 870
 871         return -errno;
 872 }
 873
 874 void unit_unwatch_timer(Unit *u, Watch *w) {
 875         assert(u);
 876         assert(w);
 877
 878         if (w->type == WATCH_INVALID)
 879                 return;
 880
 881         assert(w->type == WATCH_TIMER && w->data.unit == u);
 882
 883         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 884         assert_se(close_nointr(w->fd) == 0);
 885
 886         w->fd = -1;
 887         w->type = WATCH_INVALID;
 888         w->data.unit = NULL;
 889 }
 890
 891 bool unit_job_is_applicable(Unit *u, JobType j) {
 892         assert(u);
 893         assert(j >= 0 && j < _JOB_TYPE_MAX);
 894
 895         switch (j) {
 896
 897         case JOB_VERIFY_ACTIVE:
 898         case JOB_START:
 899                 return true;
 900
 901         case JOB_STOP:
 902         case JOB_RESTART:
 903         case JOB_TRY_RESTART:
 904                 return unit_can_start(u);
 905
 906         case JOB_RELOAD:
 907                 return unit_can_reload(u);
 908
 909         case JOB_RELOAD_OR_START:
 910                 return unit_can_reload(u) && unit_can_start(u);
 911
 912         default:
 913                 assert_not_reached("Invalid job type");
 914         }
 915 }
 916
 917 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 918
 919         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 920                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 921                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 922                 [UNIT_WANTS] = UNIT_WANTED_BY,
 923                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 924                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 925                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 926                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 927                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 928                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 929                 [UNIT_BEFORE] = UNIT_AFTER,
 930                 [UNIT_AFTER] = UNIT_BEFORE
 931         };
 932         int r;
 933
 934         assert(u);
 935         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 936         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 937         assert(other);
 938
 939         /* We won't allow dependencies on ourselves. We will not
 940          * consider them an error however. */
 941         if (u == other)
 942                 return 0;
 943
 944         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 945                 return r;
 946
 947         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 948                 return r;
 949
 950         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 951                 return r;
 952
 953         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 954                 set_remove(u->meta.dependencies[d], other);
 955                 return r;
 956         }
 957
 958         unit_add_to_dbus_queue(u);
 959         return 0;
 960 }
 961
 962 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 963         Unit *other;
 964         int r;
 965
 966         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 967                 return r;
 968
 969         if ((r = unit_add_dependency(u, d, other)) < 0)
 970                 return r;
 971
 972         return 0;
 973 }
 974
 975 const char *unit_path(void) {
 976         char *e;
 977
 978         if ((e = getenv("UNIT_PATH")))
 979                 if (path_is_absolute(e))
 980                     return e;
 981
 982         return UNIT_PATH;
 983 }
 984
 985 int set_unit_path(const char *p) {
 986         char *cwd, *c;
 987         int r;
 988
 989         /* This is mostly for debug purposes */
 990
 991         if (path_is_absolute(p)) {
 992                 if (!(c = strdup(p)))
 993                         return -ENOMEM;
 994         } else {
 995                 if (!(cwd = get_current_dir_name()))
 996                         return -errno;
 997
 998                 r = asprintf(&c, "%s/%s", cwd, p);
 999                 free(cwd);
1000
1001                 if (r < 0)
1002                         return -ENOMEM;
1003         }
1004
1005         if (setenv("UNIT_PATH", c, 0) < 0) {
1006                 r = -errno;
1007                 free(c);
1008                 return r;
1009         }
1010
1011         return 0;
1012 }
1013
1014 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
1015         char *r, *t;
1016         const char *f;
1017         size_t a, b, c;
1018
1019         assert(path);
1020
1021         /* Takes a path and a suffix and prefix and makes a nice
1022          * string suitable as unit name of it, escaping all weird
1023          * chars on the way.
1024          *
1025          * / becomes ., and all chars not alloweed in a unit name get
1026          * escaped as \xFF, including \ and ., of course. This
1027          * escaping is hence reversible.
1028          */
1029
1030         if (!prefix)
1031                 prefix = "";
1032
1033         if (!suffix)
1034                 suffix = "";
1035
1036         a = strlen(prefix);
1037         b = strlen(path);
1038         c = strlen(suffix);
1039
1040         if (!(r = new(char, a+b*4+c+1)))
1041                 return NULL;
1042
1043         memcpy(r, prefix, a);
1044
1045         for (f = path, t = r+a; *f; f++) {
1046                 if (*f == '/')
1047                         *(t++) = '.';
1048                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
1049                         *(t++) = '\\';
1050                         *(t++) = 'x';
1051                         *(t++) = hexchar(*f > 4);
1052                         *(t++) = hexchar(*f);
1053                 } else
1054                         *(t++) = *f;
1055         }
1056
1057         memcpy(t, suffix, c+1);
1058
1059         return r;
1060 }
1061
1062 char *unit_dbus_path(Unit *u) {
1063         char *p, *e;
1064
1065         assert(u);
1066
1067         if (!(e = bus_path_escape(unit_id(u))))
1068                 return NULL;
1069
1070         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1071                 free(e);
1072                 return NULL;
1073         }
1074
1075         free(e);
1076         return p;
1077 }
1078
1079 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1080         [UNIT_SERVICE] = "service",
1081         [UNIT_TIMER] = "timer",
1082         [UNIT_SOCKET] = "socket",
1083         [UNIT_TARGET] = "target",
1084         [UNIT_DEVICE] = "device",
1085         [UNIT_MOUNT] = "mount",
1086         [UNIT_AUTOMOUNT] = "automount",
1087         [UNIT_SNAPSHOT] = "snapshot"
1088 };
1089
1090 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1091
1092 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1093         [UNIT_STUB] = "stub",
1094         [UNIT_LOADED] = "loaded",
1095         [UNIT_FAILED] = "failed"
1096 };
1097
1098 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1099
1100 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1101         [UNIT_ACTIVE] = "active",
1102         [UNIT_INACTIVE] = "inactive",
1103         [UNIT_ACTIVATING] = "activating",
1104         [UNIT_DEACTIVATING] = "deactivating"
1105 };
1106
1107 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1108
1109 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1110         [UNIT_REQUIRES] = "Requires",
1111         [UNIT_SOFT_REQUIRES] = "SoftRequires",
1112         [UNIT_WANTS] = "Wants",
1113         [UNIT_REQUISITE] = "Requisite",
1114         [UNIT_SOFT_REQUISITE] = "SoftRequisite",
1115         [UNIT_REQUIRED_BY] = "RequiredBy",
1116         [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
1117         [UNIT_WANTED_BY] = "WantedBy",
1118         [UNIT_CONFLICTS] = "Conflicts",
1119         [UNIT_BEFORE] = "Before",
1120         [UNIT_AFTER] = "After",
1121 };
1122
1123 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);