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 (!UNIT_VTABLE(u)->start)
 482                 return -EBADR;
 483
 484         state = unit_active_state(u);
 485         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
 486                 return -EALREADY;
 487
 488         /* We don't suppress calls to ->start() here when we are
 489          * already starting, to allow this request to be used as a
 490          * "hurry up" call, for example when the unit is in some "auto
 491          * restart" state where it waits for a holdoff timer to elapse
 492          * before it will start again. */
 493
 494         unit_add_to_dbus_queue(u);
 495         return UNIT_VTABLE(u)->start(u);
 496 }
 497
 498 bool unit_can_start(Unit *u) {
 499         assert(u);
 500
 501         return !!UNIT_VTABLE(u)->start;
 502 }
 503
 504 /* Errors:
 505  *         -EBADR:    This unit type does not support stopping.
 506  *         -EALREADY: Unit is already stopped.
 507  *         -EAGAIN:   An operation is already in progress. Retry later.
 508  */
 509 int unit_stop(Unit *u) {
 510         UnitActiveState state;
 511
 512         assert(u);
 513
 514         if (!UNIT_VTABLE(u)->stop)
 515                 return -EBADR;
 516
 517         state = unit_active_state(u);
 518         if (state == UNIT_INACTIVE)
 519                 return -EALREADY;
 520
 521         if (state == UNIT_DEACTIVATING)
 522                 return 0;
 523
 524         unit_add_to_dbus_queue(u);
 525         return UNIT_VTABLE(u)->stop(u);
 526 }
 527
 528 /* Errors:
 529  *         -EBADR:    This unit type does not support reloading.
 530  *         -ENOEXEC:  Unit is not started.
 531  *         -EAGAIN:   An operation is already in progress. Retry later.
 532  */
 533 int unit_reload(Unit *u) {
 534         UnitActiveState state;
 535
 536         assert(u);
 537
 538         if (!unit_can_reload(u))
 539                 return -EBADR;
 540
 541         state = unit_active_state(u);
 542         if (unit_active_state(u) == UNIT_ACTIVE_RELOADING)
 543                 return -EALREADY;
 544
 545         if (unit_active_state(u) != UNIT_ACTIVE)
 546                 return -ENOEXEC;
 547
 548         unit_add_to_dbus_queue(u);
 549         return UNIT_VTABLE(u)->reload(u);
 550 }
 551
 552 bool unit_can_reload(Unit *u) {
 553         assert(u);
 554
 555         if (!UNIT_VTABLE(u)->reload)
 556                 return false;
 557
 558         if (!UNIT_VTABLE(u)->can_reload)
 559                 return true;
 560
 561         return UNIT_VTABLE(u)->can_reload(u);
 562 }
 563
 564 static void unit_check_uneeded(Unit *u) {
 565         Iterator i;
 566         Unit *other;
 567
 568         assert(u);
 569
 570         /* If this service shall be shut down when unneeded then do
 571          * so. */
 572
 573         if (!u->meta.stop_when_unneeded)
 574                 return;
 575
 576         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
 577                 return;
 578
 579         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 580                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 581                         return;
 582
 583         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
 584                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 585                         return;
 586
 587         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
 588                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 589                         return;
 590
 591         log_debug("Service %s is not needed anymore. Stopping.", unit_id(u));
 592
 593         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
 594         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL);
 595 }
 596
 597 static void retroactively_start_dependencies(Unit *u) {
 598         Iterator i;
 599         Unit *other;
 600
 601         assert(u);
 602         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
 603
 604         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 605                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 606                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 607
 608         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 609                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 610                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 611
 612         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 613                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 614                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL);
 615
 616         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 617                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 618                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL);
 619
 620         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
 621                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
 622                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 623 }
 624
 625 static void retroactively_stop_dependencies(Unit *u) {
 626         Iterator i;
 627         Unit *other;
 628
 629         assert(u);
 630         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
 631
 632         if (u->meta.recursive_stop) {
 633                 /* Pull down units need us recursively if enabled */
 634                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
 635                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 636                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL);
 637         }
 638
 639         /* Garbage collect services that might not be needed anymore, if enabled */
 640         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
 641                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 642                         unit_check_uneeded(other);
 643         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRES], i)
 644                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 645                         unit_check_uneeded(other);
 646         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
 647                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 648                         unit_check_uneeded(other);
 649         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
 650                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 651                         unit_check_uneeded(other);
 652         SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUISITE], i)
 653                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
 654                         unit_check_uneeded(other);
 655 }
 656
 657 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
 658         assert(u);
 659         assert(os < _UNIT_ACTIVE_STATE_MAX);
 660         assert(ns < _UNIT_ACTIVE_STATE_MAX);
 661         assert(!(os == UNIT_ACTIVE && ns == UNIT_ACTIVATING));
 662         assert(!(os == UNIT_INACTIVE && ns == UNIT_DEACTIVATING));
 663
 664         if (os == ns)
 665                 return;
 666
 667         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
 668                 u->meta.active_enter_timestamp = now(CLOCK_REALTIME);
 669         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
 670                 u->meta.active_exit_timestamp = now(CLOCK_REALTIME);
 671
 672         if (u->meta.job) {
 673
 674                 if (u->meta.job->state == JOB_WAITING)
 675
 676                         /* So we reached a different state for this
 677                          * job. Let's see if we can run it now if it
 678                          * failed previously due to EAGAIN. */
 679                         job_add_to_run_queue(u->meta.job);
 680
 681                 else {
 682                         assert(u->meta.job->state == JOB_RUNNING);
 683
 684                         /* Let's check whether this state change
 685                          * constitutes a finished job, or maybe
 686                          * cotradicts a running job and hence needs to
 687                          * invalidate jobs. */
 688
 689                         switch (u->meta.job->type) {
 690
 691                         case JOB_START:
 692                         case JOB_VERIFY_ACTIVE:
 693
 694                                 if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
 695                                         job_finish_and_invalidate(u->meta.job, true);
 696                                         return;
 697                                 } else if (ns == UNIT_ACTIVATING)
 698                                         return;
 699                                 else
 700                                         job_finish_and_invalidate(u->meta.job, false);
 701
 702                                 break;
 703
 704                         case JOB_RELOAD:
 705                         case JOB_RELOAD_OR_START:
 706
 707                                 if (ns == UNIT_ACTIVE) {
 708                                         job_finish_and_invalidate(u->meta.job, true);
 709                                         return;
 710                                 } else if (ns == UNIT_ACTIVATING || ns == UNIT_ACTIVE_RELOADING)
 711                                         return;
 712                                 else
 713                                         job_finish_and_invalidate(u->meta.job, false);
 714
 715                                 break;
 716
 717                         case JOB_STOP:
 718                         case JOB_RESTART:
 719                         case JOB_TRY_RESTART:
 720
 721                                 if (ns == UNIT_INACTIVE) {
 722                                         job_finish_and_invalidate(u->meta.job, true);
 723                                         return;
 724                                 } else if (ns == UNIT_DEACTIVATING)
 725                                         return;
 726                                 else
 727                                         job_finish_and_invalidate(u->meta.job, false);
 728
 729                                 break;
 730
 731                         default:
 732                                 assert_not_reached("Job type unknown");
 733                         }
 734                 }
 735         }
 736
 737         /* If this state change happened without being requested by a
 738          * job, then let's retroactively start or stop dependencies */
 739
 740         if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
 741                 retroactively_start_dependencies(u);
 742         else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
 743                 retroactively_stop_dependencies(u);
 744
 745         /* Maybe we finished startup and are now ready for being
 746          * stopped because unneeded? */
 747         unit_check_uneeded(u);
 748
 749         unit_add_to_dbus_queue(u);
 750 }
 751
 752 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
 753         struct epoll_event ev;
 754
 755         assert(u);
 756         assert(fd >= 0);
 757         assert(w);
 758         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
 759
 760         zero(ev);
 761         ev.data.ptr = w;
 762         ev.events = events;
 763
 764         if (epoll_ctl(u->meta.manager->epoll_fd,
 765                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
 766                       fd,
 767                       &ev) < 0)
 768                 return -errno;
 769
 770         w->fd = fd;
 771         w->type = WATCH_FD;
 772         w->data.unit = u;
 773
 774         return 0;
 775 }
 776
 777 void unit_unwatch_fd(Unit *u, Watch *w) {
 778         assert(u);
 779         assert(w);
 780
 781         if (w->type == WATCH_INVALID)
 782                 return;
 783
 784         assert(w->type == WATCH_FD);
 785         assert(w->data.unit == u);
 786         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 787
 788         w->fd = -1;
 789         w->type = WATCH_INVALID;
 790         w->data.unit = NULL;
 791 }
 792
 793 int unit_watch_pid(Unit *u, pid_t pid) {
 794         assert(u);
 795         assert(pid >= 1);
 796
 797         return hashmap_put(u->meta.manager->watch_pids, UINT32_TO_PTR(pid), u);
 798 }
 799
 800 void unit_unwatch_pid(Unit *u, pid_t pid) {
 801         assert(u);
 802         assert(pid >= 1);
 803
 804         hashmap_remove(u->meta.manager->watch_pids, UINT32_TO_PTR(pid));
 805 }
 806
 807 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
 808         struct itimerspec its;
 809         int flags, fd;
 810         bool ours;
 811
 812         assert(u);
 813         assert(w);
 814         assert(w->type == WATCH_INVALID || (w->type == WATCH_TIMER && w->data.unit == u));
 815
 816         /* This will try to reuse the old timer if there is one */
 817
 818         if (w->type == WATCH_TIMER) {
 819                 ours = false;
 820                 fd = w->fd;
 821         } else {
 822                 ours = true;
 823                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
 824                         return -errno;
 825         }
 826
 827         zero(its);
 828
 829         if (delay <= 0) {
 830                 /* Set absolute time in the past, but not 0, since we
 831                  * don't want to disarm the timer */
 832                 its.it_value.tv_sec = 0;
 833                 its.it_value.tv_nsec = 1;
 834
 835                 flags = TFD_TIMER_ABSTIME;
 836         } else {
 837                 timespec_store(&its.it_value, delay);
 838                 flags = 0;
 839         }
 840
 841         /* This will also flush the elapse counter */
 842         if (timerfd_settime(fd, flags, &its, NULL) < 0)
 843                 goto fail;
 844
 845         if (w->type == WATCH_INVALID) {
 846                 struct epoll_event ev;
 847
 848                 zero(ev);
 849                 ev.data.ptr = w;
 850                 ev.events = EPOLLIN;
 851
 852                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
 853                         goto fail;
 854         }
 855
 856         w->fd = fd;
 857         w->type = WATCH_TIMER;
 858         w->data.unit = u;
 859
 860         return 0;
 861
 862 fail:
 863         if (ours)
 864                 close_nointr_nofail(fd);
 865
 866         return -errno;
 867 }
 868
 869 void unit_unwatch_timer(Unit *u, Watch *w) {
 870         assert(u);
 871         assert(w);
 872
 873         if (w->type == WATCH_INVALID)
 874                 return;
 875
 876         assert(w->type == WATCH_TIMER && w->data.unit == u);
 877
 878         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
 879         assert_se(close_nointr(w->fd) == 0);
 880
 881         w->fd = -1;
 882         w->type = WATCH_INVALID;
 883         w->data.unit = NULL;
 884 }
 885
 886 bool unit_job_is_applicable(Unit *u, JobType j) {
 887         assert(u);
 888         assert(j >= 0 && j < _JOB_TYPE_MAX);
 889
 890         switch (j) {
 891
 892         case JOB_VERIFY_ACTIVE:
 893         case JOB_START:
 894                 return true;
 895
 896         case JOB_STOP:
 897         case JOB_RESTART:
 898         case JOB_TRY_RESTART:
 899                 return unit_can_start(u);
 900
 901         case JOB_RELOAD:
 902                 return unit_can_reload(u);
 903
 904         case JOB_RELOAD_OR_START:
 905                 return unit_can_reload(u) && unit_can_start(u);
 906
 907         default:
 908                 assert_not_reached("Invalid job type");
 909         }
 910 }
 911
 912 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other) {
 913
 914         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
 915                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
 916                 [UNIT_SOFT_REQUIRES] = UNIT_SOFT_REQUIRED_BY,
 917                 [UNIT_WANTS] = UNIT_WANTED_BY,
 918                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
 919                 [UNIT_SOFT_REQUISITE] = UNIT_SOFT_REQUIRED_BY,
 920                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 921                 [UNIT_SOFT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
 922                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
 923                 [UNIT_CONFLICTS] = UNIT_CONFLICTS,
 924                 [UNIT_BEFORE] = UNIT_AFTER,
 925                 [UNIT_AFTER] = UNIT_BEFORE
 926         };
 927         int r;
 928
 929         assert(u);
 930         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
 931         assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
 932         assert(other);
 933
 934         /* We won't allow dependencies on ourselves. We will not
 935          * consider them an error however. */
 936         if (u == other)
 937                 return 0;
 938
 939         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
 940                 return r;
 941
 942         if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
 943                 return r;
 944
 945         if ((r = set_put(u->meta.dependencies[d], other)) < 0)
 946                 return r;
 947
 948         if ((r = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
 949                 set_remove(u->meta.dependencies[d], other);
 950                 return r;
 951         }
 952
 953         unit_add_to_dbus_queue(u);
 954         return 0;
 955 }
 956
 957 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name) {
 958         Unit *other;
 959         int r;
 960
 961         if ((r = manager_load_unit(u->meta.manager, name, &other)) < 0)
 962                 return r;
 963
 964         if ((r = unit_add_dependency(u, d, other)) < 0)
 965                 return r;
 966
 967         return 0;
 968 }
 969
 970 const char *unit_path(void) {
 971         char *e;
 972
 973         if ((e = getenv("UNIT_PATH")))
 974                 if (path_is_absolute(e))
 975                     return e;
 976
 977         return UNIT_PATH;
 978 }
 979
 980 int set_unit_path(const char *p) {
 981         char *cwd, *c;
 982         int r;
 983
 984         /* This is mostly for debug purposes */
 985
 986         if (path_is_absolute(p)) {
 987                 if (!(c = strdup(p)))
 988                         return -ENOMEM;
 989         } else {
 990                 if (!(cwd = get_current_dir_name()))
 991                         return -errno;
 992
 993                 r = asprintf(&c, "%s/%s", cwd, p);
 994                 free(cwd);
 995
 996                 if (r < 0)
 997                         return -ENOMEM;
 998         }
 999
1000         if (setenv("UNIT_PATH", c, 0) < 0) {
1001                 r = -errno;
1002                 free(c);
1003                 return r;
1004         }
1005
1006         return 0;
1007 }
1008
1009 char *unit_name_escape_path(const char *prefix, const char *path, const char *suffix) {
1010         char *r, *t;
1011         const char *f;
1012         size_t a, b, c;
1013
1014         assert(path);
1015
1016         /* Takes a path and a suffix and prefix and makes a nice
1017          * string suitable as unit name of it, escaping all weird
1018          * chars on the way.
1019          *
1020          * / becomes ., and all chars not alloweed in a unit name get
1021          * escaped as \xFF, including \ and ., of course. This
1022          * escaping is hence reversible.
1023          */
1024
1025         if (!prefix)
1026                 prefix = "";
1027
1028         if (!suffix)
1029                 suffix = "";
1030
1031         a = strlen(prefix);
1032         b = strlen(path);
1033         c = strlen(suffix);
1034
1035         if (!(r = new(char, a+b*4+c+1)))
1036                 return NULL;
1037
1038         memcpy(r, prefix, a);
1039
1040         for (f = path, t = r+a; *f; f++) {
1041                 if (*f == '/')
1042                         *(t++) = '.';
1043                 else if (*f == '.' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
1044                         *(t++) = '\\';
1045                         *(t++) = 'x';
1046                         *(t++) = hexchar(*f > 4);
1047                         *(t++) = hexchar(*f);
1048                 } else
1049                         *(t++) = *f;
1050         }
1051
1052         memcpy(t, suffix, c+1);
1053
1054         return r;
1055 }
1056
1057 char *unit_dbus_path(Unit *u) {
1058         char *p, *e;
1059
1060         assert(u);
1061
1062         if (!(e = bus_path_escape(unit_id(u))))
1063                 return NULL;
1064
1065         if (asprintf(&p, "/org/freedesktop/systemd1/unit/%s", e) < 0) {
1066                 free(e);
1067                 return NULL;
1068         }
1069
1070         free(e);
1071         return p;
1072 }
1073
1074 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
1075         [UNIT_SERVICE] = "service",
1076         [UNIT_TIMER] = "timer",
1077         [UNIT_SOCKET] = "socket",
1078         [UNIT_TARGET] = "target",
1079         [UNIT_DEVICE] = "device",
1080         [UNIT_MOUNT] = "mount",
1081         [UNIT_AUTOMOUNT] = "automount",
1082         [UNIT_SNAPSHOT] = "snapshot"
1083 };
1084
1085 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
1086
1087 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
1088         [UNIT_STUB] = "stub",
1089         [UNIT_LOADED] = "loaded",
1090         [UNIT_FAILED] = "failed"
1091 };
1092
1093 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
1094
1095 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
1096         [UNIT_ACTIVE] = "active",
1097         [UNIT_INACTIVE] = "inactive",
1098         [UNIT_ACTIVATING] = "activating",
1099         [UNIT_DEACTIVATING] = "deactivating"
1100 };
1101
1102 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
1103
1104 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
1105         [UNIT_REQUIRES] = "Requires",
1106         [UNIT_SOFT_REQUIRES] = "SoftRequires",
1107         [UNIT_WANTS] = "Wants",
1108         [UNIT_REQUISITE] = "Requisite",
1109         [UNIT_SOFT_REQUISITE] = "SoftRequisite",
1110         [UNIT_REQUIRED_BY] = "RequiredBy",
1111         [UNIT_SOFT_REQUIRED_BY] = "SoftRequiredBy",
1112         [UNIT_WANTED_BY] = "WantedBy",
1113         [UNIT_CONFLICTS] = "Conflicts",
1114         [UNIT_BEFORE] = "Before",
1115         [UNIT_AFTER] = "After",
1116 };
1117
1118 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);