chiark / gitweb /
util: when replacing env vars replace unset envvars by nothing
[elogind.git] / src / 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 #include <sys/stat.h>
31
32 #include "set.h"
33 #include "unit.h"
34 #include "macro.h"
35 #include "strv.h"
36 #include "load-fragment.h"
37 #include "load-dropin.h"
38 #include "log.h"
39 #include "unit-name.h"
40 #include "specifier.h"
41 #include "dbus-unit.h"
42 #include "special.h"
43 #include "cgroup-util.h"
44
45 const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
46         [UNIT_SERVICE] = &service_vtable,
47         [UNIT_TIMER] = &timer_vtable,
48         [UNIT_SOCKET] = &socket_vtable,
49         [UNIT_TARGET] = &target_vtable,
50         [UNIT_DEVICE] = &device_vtable,
51         [UNIT_MOUNT] = &mount_vtable,
52         [UNIT_AUTOMOUNT] = &automount_vtable,
53         [UNIT_SNAPSHOT] = &snapshot_vtable,
54         [UNIT_SWAP] = &swap_vtable,
55         [UNIT_PATH] = &path_vtable
56 };
57
58 Unit *unit_new(Manager *m) {
59         Unit *u;
60
61         assert(m);
62
63         if (!(u = new0(Unit, 1)))
64                 return NULL;
65
66         if (!(u->meta.names = set_new(string_hash_func, string_compare_func))) {
67                 free(u);
68                 return NULL;
69         }
70
71         u->meta.manager = m;
72         u->meta.type = _UNIT_TYPE_INVALID;
73         u->meta.deserialized_job = _JOB_TYPE_INVALID;
74         u->meta.default_dependencies = true;
75
76         return u;
77 }
78
79 bool unit_has_name(Unit *u, const char *name) {
80         assert(u);
81         assert(name);
82
83         return !!set_get(u->meta.names, (char*) name);
84 }
85
86 int unit_add_name(Unit *u, const char *text) {
87         UnitType t;
88         char *s, *i = NULL;
89         int r;
90
91         assert(u);
92         assert(text);
93
94         if (unit_name_is_template(text)) {
95                 if (!u->meta.instance)
96                         return -EINVAL;
97
98                 s = unit_name_replace_instance(text, u->meta.instance);
99         } else
100                 s = strdup(text);
101
102         if (!s)
103                 return -ENOMEM;
104
105         if (!unit_name_is_valid(s)) {
106                 r = -EINVAL;
107                 goto fail;
108         }
109
110         assert_se((t = unit_name_to_type(s)) >= 0);
111
112         if (u->meta.type != _UNIT_TYPE_INVALID && t != u->meta.type) {
113                 r = -EINVAL;
114                 goto fail;
115         }
116
117         if ((r = unit_name_to_instance(s, &i)) < 0)
118                 goto fail;
119
120         if (i && unit_vtable[t]->no_instances)
121                 goto fail;
122
123         /* Ensure that this unit is either instanced or not instanced,
124          * but not both. */
125         if (u->meta.type != _UNIT_TYPE_INVALID && !u->meta.instance != !i) {
126                 r = -EINVAL;
127                 goto fail;
128         }
129
130         if (unit_vtable[t]->no_alias &&
131             !set_isempty(u->meta.names) &&
132             !set_get(u->meta.names, s)) {
133                 r = -EEXIST;
134                 goto fail;
135         }
136
137         if (hashmap_size(u->meta.manager->units) >= MANAGER_MAX_NAMES) {
138                 r = -E2BIG;
139                 goto fail;
140         }
141
142         if ((r = set_put(u->meta.names, s)) < 0) {
143                 if (r == -EEXIST)
144                         r = 0;
145                 goto fail;
146         }
147
148         if ((r = hashmap_put(u->meta.manager->units, s, u)) < 0) {
149                 set_remove(u->meta.names, s);
150                 goto fail;
151         }
152
153         if (u->meta.type == _UNIT_TYPE_INVALID) {
154
155                 u->meta.type = t;
156                 u->meta.id = s;
157                 u->meta.instance = i;
158
159                 LIST_PREPEND(Meta, units_per_type, u->meta.manager->units_per_type[t], &u->meta);
160
161                 if (UNIT_VTABLE(u)->init)
162                         UNIT_VTABLE(u)->init(u);
163         } else
164                 free(i);
165
166         unit_add_to_dbus_queue(u);
167         return 0;
168
169 fail:
170         free(s);
171         free(i);
172
173         return r;
174 }
175
176 int unit_choose_id(Unit *u, const char *name) {
177         char *s, *t = NULL, *i;
178         int r;
179
180         assert(u);
181         assert(name);
182
183         if (unit_name_is_template(name)) {
184
185                 if (!u->meta.instance)
186                         return -EINVAL;
187
188                 if (!(t = unit_name_replace_instance(name, u->meta.instance)))
189                         return -ENOMEM;
190
191                 name = t;
192         }
193
194         /* Selects one of the names of this unit as the id */
195         s = set_get(u->meta.names, (char*) name);
196         free(t);
197
198         if (!s)
199                 return -ENOENT;
200
201         if ((r = unit_name_to_instance(s, &i)) < 0)
202                 return r;
203
204         u->meta.id = s;
205
206         free(u->meta.instance);
207         u->meta.instance = i;
208
209         unit_add_to_dbus_queue(u);
210
211         return 0;
212 }
213
214 int unit_set_description(Unit *u, const char *description) {
215         char *s;
216
217         assert(u);
218
219         if (!(s = strdup(description)))
220                 return -ENOMEM;
221
222         free(u->meta.description);
223         u->meta.description = s;
224
225         unit_add_to_dbus_queue(u);
226         return 0;
227 }
228
229 bool unit_check_gc(Unit *u) {
230         assert(u);
231
232         if (u->meta.load_state == UNIT_STUB)
233                 return true;
234
235         if (UNIT_VTABLE(u)->no_gc)
236                 return true;
237
238         if (u->meta.job)
239                 return true;
240
241         if (unit_active_state(u) != UNIT_INACTIVE)
242                 return true;
243
244         if (UNIT_VTABLE(u)->check_gc)
245                 if (UNIT_VTABLE(u)->check_gc(u))
246                         return true;
247
248         return false;
249 }
250
251 void unit_add_to_load_queue(Unit *u) {
252         assert(u);
253         assert(u->meta.type != _UNIT_TYPE_INVALID);
254
255         if (u->meta.load_state != UNIT_STUB || u->meta.in_load_queue)
256                 return;
257
258         LIST_PREPEND(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
259         u->meta.in_load_queue = true;
260 }
261
262 void unit_add_to_cleanup_queue(Unit *u) {
263         assert(u);
264
265         if (u->meta.in_cleanup_queue)
266                 return;
267
268         LIST_PREPEND(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
269         u->meta.in_cleanup_queue = true;
270 }
271
272 void unit_add_to_gc_queue(Unit *u) {
273         assert(u);
274
275         if (u->meta.in_gc_queue || u->meta.in_cleanup_queue)
276                 return;
277
278         if (unit_check_gc(u))
279                 return;
280
281         LIST_PREPEND(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
282         u->meta.in_gc_queue = true;
283
284         u->meta.manager->n_in_gc_queue ++;
285
286         if (u->meta.manager->gc_queue_timestamp <= 0)
287                 u->meta.manager->gc_queue_timestamp = now(CLOCK_MONOTONIC);
288 }
289
290 void unit_add_to_dbus_queue(Unit *u) {
291         assert(u);
292         assert(u->meta.type != _UNIT_TYPE_INVALID);
293
294         if (u->meta.load_state == UNIT_STUB || u->meta.in_dbus_queue)
295                 return;
296
297         /* Shortcut things if nobody cares */
298         if (!bus_has_subscriber(u->meta.manager)) {
299                 u->meta.sent_dbus_new_signal = true;
300                 return;
301         }
302
303         LIST_PREPEND(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
304         u->meta.in_dbus_queue = true;
305 }
306
307 static void bidi_set_free(Unit *u, Set *s) {
308         Iterator i;
309         Unit *other;
310
311         assert(u);
312
313         /* Frees the set and makes sure we are dropped from the
314          * inverse pointers */
315
316         SET_FOREACH(other, s, i) {
317                 UnitDependency d;
318
319                 for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
320                         set_remove(other->meta.dependencies[d], u);
321
322                 unit_add_to_gc_queue(other);
323         }
324
325         set_free(s);
326 }
327
328 void unit_free(Unit *u) {
329         UnitDependency d;
330         Iterator i;
331         char *t;
332
333         assert(u);
334
335         bus_unit_send_removed_signal(u);
336
337         if (u->meta.load_state != UNIT_STUB)
338                 if (UNIT_VTABLE(u)->done)
339                         UNIT_VTABLE(u)->done(u);
340
341         SET_FOREACH(t, u->meta.names, i)
342                 hashmap_remove_value(u->meta.manager->units, t, u);
343
344         if (u->meta.job)
345                 job_free(u->meta.job);
346
347         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
348                 bidi_set_free(u, u->meta.dependencies[d]);
349
350         if (u->meta.type != _UNIT_TYPE_INVALID)
351                 LIST_REMOVE(Meta, units_per_type, u->meta.manager->units_per_type[u->meta.type], &u->meta);
352
353         if (u->meta.in_load_queue)
354                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
355
356         if (u->meta.in_dbus_queue)
357                 LIST_REMOVE(Meta, dbus_queue, u->meta.manager->dbus_unit_queue, &u->meta);
358
359         if (u->meta.in_cleanup_queue)
360                 LIST_REMOVE(Meta, cleanup_queue, u->meta.manager->cleanup_queue, &u->meta);
361
362         if (u->meta.in_gc_queue) {
363                 LIST_REMOVE(Meta, gc_queue, u->meta.manager->gc_queue, &u->meta);
364                 u->meta.manager->n_in_gc_queue--;
365         }
366
367         cgroup_bonding_free_list(u->meta.cgroup_bondings);
368
369         free(u->meta.description);
370         free(u->meta.fragment_path);
371
372         set_free_free(u->meta.names);
373
374         free(u->meta.instance);
375
376         free(u);
377 }
378
379 UnitActiveState unit_active_state(Unit *u) {
380         assert(u);
381
382         if (u->meta.load_state == UNIT_MERGED)
383                 return unit_active_state(unit_follow_merge(u));
384
385         /* After a reload it might happen that a unit is not correctly
386          * loaded but still has a process around. That's why we won't
387          * shortcut failed loading to UNIT_INACTIVE_MAINTENANCE. */
388
389         return UNIT_VTABLE(u)->active_state(u);
390 }
391
392 const char* unit_sub_state_to_string(Unit *u) {
393         assert(u);
394
395         return UNIT_VTABLE(u)->sub_state_to_string(u);
396 }
397
398 static void complete_move(Set **s, Set **other) {
399         assert(s);
400         assert(other);
401
402         if (!*other)
403                 return;
404
405         if (*s)
406                 set_move(*s, *other);
407         else {
408                 *s = *other;
409                 *other = NULL;
410         }
411 }
412
413 static void merge_names(Unit *u, Unit *other) {
414         char *t;
415         Iterator i;
416
417         assert(u);
418         assert(other);
419
420         complete_move(&u->meta.names, &other->meta.names);
421
422         set_free_free(other->meta.names);
423         other->meta.names = NULL;
424         other->meta.id = NULL;
425
426         SET_FOREACH(t, u->meta.names, i)
427                 assert_se(hashmap_replace(u->meta.manager->units, t, u) == 0);
428 }
429
430 static void merge_dependencies(Unit *u, Unit *other, UnitDependency d) {
431         Iterator i;
432         Unit *back;
433         int r;
434
435         assert(u);
436         assert(other);
437         assert(d < _UNIT_DEPENDENCY_MAX);
438
439         SET_FOREACH(back, other->meta.dependencies[d], i) {
440                 UnitDependency k;
441
442                 for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++)
443                         if ((r = set_remove_and_put(back->meta.dependencies[k], other, u)) < 0) {
444
445                                 if (r == -EEXIST)
446                                         set_remove(back->meta.dependencies[k], other);
447                                 else
448                                         assert(r == -ENOENT);
449                         }
450         }
451
452         complete_move(&u->meta.dependencies[d], &other->meta.dependencies[d]);
453
454         set_free(other->meta.dependencies[d]);
455         other->meta.dependencies[d] = NULL;
456 }
457
458 int unit_merge(Unit *u, Unit *other) {
459         UnitDependency d;
460
461         assert(u);
462         assert(other);
463         assert(u->meta.manager == other->meta.manager);
464         assert(u->meta.type != _UNIT_TYPE_INVALID);
465
466         other = unit_follow_merge(other);
467
468         if (other == u)
469                 return 0;
470
471         if (u->meta.type != other->meta.type)
472                 return -EINVAL;
473
474         if (!u->meta.instance != !other->meta.instance)
475                 return -EINVAL;
476
477         if (other->meta.load_state != UNIT_STUB &&
478             other->meta.load_state != UNIT_FAILED)
479                 return -EEXIST;
480
481         if (other->meta.job)
482                 return -EEXIST;
483
484         if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(other)))
485                 return -EEXIST;
486
487         /* Merge names */
488         merge_names(u, other);
489
490         /* Merge dependencies */
491         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
492                 merge_dependencies(u, other, d);
493
494         other->meta.load_state = UNIT_MERGED;
495         other->meta.merged_into = u;
496
497         /* If there is still some data attached to the other node, we
498          * don't need it anymore, and can free it. */
499         if (other->meta.load_state != UNIT_STUB)
500                 if (UNIT_VTABLE(other)->done)
501                         UNIT_VTABLE(other)->done(other);
502
503         unit_add_to_dbus_queue(u);
504         unit_add_to_cleanup_queue(other);
505
506         return 0;
507 }
508
509 int unit_merge_by_name(Unit *u, const char *name) {
510         Unit *other;
511         int r;
512         char *s = NULL;
513
514         assert(u);
515         assert(name);
516
517         if (unit_name_is_template(name)) {
518                 if (!u->meta.instance)
519                         return -EINVAL;
520
521                 if (!(s = unit_name_replace_instance(name, u->meta.instance)))
522                         return -ENOMEM;
523
524                 name = s;
525         }
526
527         if (!(other = manager_get_unit(u->meta.manager, name)))
528                 r = unit_add_name(u, name);
529         else
530                 r = unit_merge(u, other);
531
532         free(s);
533         return r;
534 }
535
536 Unit* unit_follow_merge(Unit *u) {
537         assert(u);
538
539         while (u->meta.load_state == UNIT_MERGED)
540                 assert_se(u = u->meta.merged_into);
541
542         return u;
543 }
544
545 int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
546         int r;
547
548         assert(u);
549         assert(c);
550
551         if (c->std_output != EXEC_OUTPUT_KMSG &&
552             c->std_output != EXEC_OUTPUT_SYSLOG &&
553             c->std_error != EXEC_OUTPUT_KMSG &&
554             c->std_error != EXEC_OUTPUT_SYSLOG)
555                 return 0;
556
557         /* If syslog or kernel logging is requested, make sure our own
558          * logging daemon is run first. */
559
560         if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
561                 return r;
562
563         if (u->meta.manager->running_as == MANAGER_SYSTEM)
564                 if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, SPECIAL_LOGGER_SOCKET, NULL, true)) < 0)
565                         return r;
566
567         return 0;
568 }
569
570 const char *unit_description(Unit *u) {
571         assert(u);
572
573         if (u->meta.description)
574                 return u->meta.description;
575
576         return u->meta.id;
577 }
578
579 void unit_dump(Unit *u, FILE *f, const char *prefix) {
580         char *t;
581         UnitDependency d;
582         Iterator i;
583         char *p2;
584         const char *prefix2;
585         CGroupBonding *b;
586         char
587                 timestamp1[FORMAT_TIMESTAMP_MAX],
588                 timestamp2[FORMAT_TIMESTAMP_MAX],
589                 timestamp3[FORMAT_TIMESTAMP_MAX],
590                 timestamp4[FORMAT_TIMESTAMP_MAX],
591                 timespan[FORMAT_TIMESPAN_MAX];
592         Unit *following;
593
594         assert(u);
595         assert(u->meta.type >= 0);
596
597         if (!prefix)
598                 prefix = "";
599         p2 = strappend(prefix, "\t");
600         prefix2 = p2 ? p2 : prefix;
601
602         fprintf(f,
603                 "%s-> Unit %s:\n"
604                 "%s\tDescription: %s\n"
605                 "%s\tInstance: %s\n"
606                 "%s\tUnit Load State: %s\n"
607                 "%s\tUnit Active State: %s\n"
608                 "%s\tInactive Exit Timestamp: %s\n"
609                 "%s\tActive Enter Timestamp: %s\n"
610                 "%s\tActive Exit Timestamp: %s\n"
611                 "%s\tInactive Enter Timestamp: %s\n"
612                 "%s\tGC Check Good: %s\n"
613                 "%s\tNeed Daemon Reload: %s\n",
614                 prefix, u->meta.id,
615                 prefix, unit_description(u),
616                 prefix, strna(u->meta.instance),
617                 prefix, unit_load_state_to_string(u->meta.load_state),
618                 prefix, unit_active_state_to_string(unit_active_state(u)),
619                 prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->meta.inactive_exit_timestamp.realtime)),
620                 prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->meta.active_enter_timestamp.realtime)),
621                 prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->meta.active_exit_timestamp.realtime)),
622                 prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->meta.inactive_enter_timestamp.realtime)),
623                 prefix, yes_no(unit_check_gc(u)),
624                 prefix, yes_no(unit_need_daemon_reload(u)));
625
626         SET_FOREACH(t, u->meta.names, i)
627                 fprintf(f, "%s\tName: %s\n", prefix, t);
628
629         if ((following = unit_following(u)))
630                 fprintf(f, "%s\tFollowing: %s\n", prefix, following->meta.id);
631
632         if (u->meta.fragment_path)
633                 fprintf(f, "%s\tFragment Path: %s\n", prefix, u->meta.fragment_path);
634
635         if (u->meta.job_timeout > 0)
636                 fprintf(f, "%s\tJob Timeout: %s\n", prefix, format_timespan(timespan, sizeof(timespan), u->meta.job_timeout));
637
638         for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
639                 Unit *other;
640
641                 SET_FOREACH(other, u->meta.dependencies[d], i)
642                         fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->meta.id);
643         }
644
645         if (u->meta.load_state == UNIT_LOADED) {
646                 fprintf(f,
647                         "%s\tRecursive Stop: %s\n"
648                         "%s\tStopWhenUnneeded: %s\n"
649                         "%s\tRefuseManualStart: %s\n"
650                         "%s\tRefuseManualStop: %s\n"
651                         "%s\tDefaultDependencies: %s\n"
652                         "%s\tIgnoreDependencyFailure: %s\n",
653                         prefix, yes_no(u->meta.recursive_stop),
654                         prefix, yes_no(u->meta.stop_when_unneeded),
655                         prefix, yes_no(u->meta.refuse_manual_start),
656                         prefix, yes_no(u->meta.refuse_manual_stop),
657                         prefix, yes_no(u->meta.default_dependencies),
658                         prefix, yes_no(u->meta.ignore_dependency_failure));
659
660                 LIST_FOREACH(by_unit, b, u->meta.cgroup_bondings)
661                         fprintf(f, "%s\tControlGroup: %s:%s\n",
662                                 prefix, b->controller, b->path);
663
664                 if (UNIT_VTABLE(u)->dump)
665                         UNIT_VTABLE(u)->dump(u, f, prefix2);
666
667         } else if (u->meta.load_state == UNIT_MERGED)
668                 fprintf(f,
669                         "%s\tMerged into: %s\n",
670                         prefix, u->meta.merged_into->meta.id);
671
672         if (u->meta.job)
673                 job_dump(u->meta.job, f, prefix2);
674
675         free(p2);
676 }
677
678 /* Common implementation for multiple backends */
679 int unit_load_fragment_and_dropin(Unit *u) {
680         int r;
681
682         assert(u);
683
684         /* Load a .service file */
685         if ((r = unit_load_fragment(u)) < 0)
686                 return r;
687
688         if (u->meta.load_state == UNIT_STUB)
689                 return -ENOENT;
690
691         /* Load drop-in directory data */
692         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
693                 return r;
694
695         return 0;
696 }
697
698 /* Common implementation for multiple backends */
699 int unit_load_fragment_and_dropin_optional(Unit *u) {
700         int r;
701
702         assert(u);
703
704         /* Same as unit_load_fragment_and_dropin(), but whether
705          * something can be loaded or not doesn't matter. */
706
707         /* Load a .service file */
708         if ((r = unit_load_fragment(u)) < 0)
709                 return r;
710
711         if (u->meta.load_state == UNIT_STUB)
712                 u->meta.load_state = UNIT_LOADED;
713
714         /* Load drop-in directory data */
715         if ((r = unit_load_dropin(unit_follow_merge(u))) < 0)
716                 return r;
717
718         return 0;
719 }
720
721 /* Common implementation for multiple backends */
722 int unit_load_nop(Unit *u) {
723         assert(u);
724
725         if (u->meta.load_state == UNIT_STUB)
726                 u->meta.load_state = UNIT_LOADED;
727
728         return 0;
729 }
730
731 int unit_load(Unit *u) {
732         int r;
733
734         assert(u);
735
736         if (u->meta.in_load_queue) {
737                 LIST_REMOVE(Meta, load_queue, u->meta.manager->load_queue, &u->meta);
738                 u->meta.in_load_queue = false;
739         }
740
741         if (u->meta.type == _UNIT_TYPE_INVALID)
742                 return -EINVAL;
743
744         if (u->meta.load_state != UNIT_STUB)
745                 return 0;
746
747         if (UNIT_VTABLE(u)->load)
748                 if ((r = UNIT_VTABLE(u)->load(u)) < 0)
749                         goto fail;
750
751         if (u->meta.load_state == UNIT_STUB) {
752                 r = -ENOENT;
753                 goto fail;
754         }
755
756         assert((u->meta.load_state != UNIT_MERGED) == !u->meta.merged_into);
757
758         unit_add_to_dbus_queue(unit_follow_merge(u));
759         unit_add_to_gc_queue(u);
760
761         return 0;
762
763 fail:
764         u->meta.load_state = UNIT_FAILED;
765         unit_add_to_dbus_queue(u);
766
767         log_notice("Failed to load configuration for %s: %s", u->meta.id, strerror(-r));
768
769         return r;
770 }
771
772 /* Errors:
773  *         -EBADR:     This unit type does not support starting.
774  *         -EALREADY:  Unit is already started.
775  *         -EAGAIN:    An operation is already in progress. Retry later.
776  *         -ECANCELED: Too many requests for now.
777  */
778 int unit_start(Unit *u) {
779         UnitActiveState state;
780
781         assert(u);
782
783         if (u->meta.load_state != UNIT_LOADED)
784                 return -EINVAL;
785
786         /* If this is already (being) started, then this will
787          * succeed. Note that this will even succeed if this unit is
788          * not startable by the user. This is relied on to detect when
789          * we need to wait for units and when waiting is finished. */
790         state = unit_active_state(u);
791         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
792                 return -EALREADY;
793
794         /* If it is stopped, but we cannot start it, then fail */
795         if (!UNIT_VTABLE(u)->start)
796                 return -EBADR;
797
798         /* We don't suppress calls to ->start() here when we are
799          * already starting, to allow this request to be used as a
800          * "hurry up" call, for example when the unit is in some "auto
801          * restart" state where it waits for a holdoff timer to elapse
802          * before it will start again. */
803
804         unit_add_to_dbus_queue(u);
805
806         unit_status_printf(u, "Starting %s...\n", unit_description(u));
807
808         return UNIT_VTABLE(u)->start(u);
809 }
810
811 bool unit_can_start(Unit *u) {
812         assert(u);
813
814         return !!UNIT_VTABLE(u)->start;
815 }
816
817 /* Errors:
818  *         -EBADR:    This unit type does not support stopping.
819  *         -EALREADY: Unit is already stopped.
820  *         -EAGAIN:   An operation is already in progress. Retry later.
821  */
822 int unit_stop(Unit *u) {
823         UnitActiveState state;
824
825         assert(u);
826
827         state = unit_active_state(u);
828         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(state))
829                 return -EALREADY;
830
831         if (!UNIT_VTABLE(u)->stop)
832                 return -EBADR;
833
834         unit_add_to_dbus_queue(u);
835
836         unit_status_printf(u, "Stopping %s...\n", unit_description(u));
837
838         return UNIT_VTABLE(u)->stop(u);
839 }
840
841 /* Errors:
842  *         -EBADR:    This unit type does not support reloading.
843  *         -ENOEXEC:  Unit is not started.
844  *         -EAGAIN:   An operation is already in progress. Retry later.
845  */
846 int unit_reload(Unit *u) {
847         UnitActiveState state;
848
849         assert(u);
850
851         if (u->meta.load_state != UNIT_LOADED)
852                 return -EINVAL;
853
854         if (!unit_can_reload(u))
855                 return -EBADR;
856
857         state = unit_active_state(u);
858         if (unit_active_state(u) == UNIT_RELOADING)
859                 return -EALREADY;
860
861         if (unit_active_state(u) != UNIT_ACTIVE)
862                 return -ENOEXEC;
863
864         unit_add_to_dbus_queue(u);
865         return UNIT_VTABLE(u)->reload(u);
866 }
867
868 bool unit_can_reload(Unit *u) {
869         assert(u);
870
871         if (!UNIT_VTABLE(u)->reload)
872                 return false;
873
874         if (!UNIT_VTABLE(u)->can_reload)
875                 return true;
876
877         return UNIT_VTABLE(u)->can_reload(u);
878 }
879
880 static void unit_check_uneeded(Unit *u) {
881         Iterator i;
882         Unit *other;
883
884         assert(u);
885
886         /* If this service shall be shut down when unneeded then do
887          * so. */
888
889         if (!u->meta.stop_when_unneeded)
890                 return;
891
892         if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
893                 return;
894
895         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
896                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
897                         return;
898
899         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i)
900                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
901                         return;
902
903         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTED_BY], i)
904                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
905                         return;
906
907         log_info("Service %s is not needed anymore. Stopping.", u->meta.id);
908
909         /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
910         manager_add_job(u->meta.manager, JOB_STOP, u, JOB_FAIL, true, NULL, NULL);
911 }
912
913 static void retroactively_start_dependencies(Unit *u) {
914         Iterator i;
915         Unit *other;
916
917         assert(u);
918         assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
919
920         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
921                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
922                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
923
924         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
925                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
926                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
927
928         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
929                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
930                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
931
932         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
933                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
934                         manager_add_job(u->meta.manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
935
936         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i)
937                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
938                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
939
940         SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTED_BY], i)
941                 if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
942                         manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
943 }
944
945 static void retroactively_stop_dependencies(Unit *u) {
946         Iterator i;
947         Unit *other;
948
949         assert(u);
950         assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
951
952         if (u->meta.recursive_stop) {
953                 /* Pull down units need us recursively if enabled */
954                 SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i)
955                         if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
956                                 manager_add_job(u->meta.manager, JOB_STOP, other, JOB_REPLACE, true, NULL, NULL);
957         }
958
959         /* Garbage collect services that might not be needed anymore, if enabled */
960         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES], i)
961                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
962                         unit_check_uneeded(other);
963         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
964                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
965                         unit_check_uneeded(other);
966         SET_FOREACH(other, u->meta.dependencies[UNIT_WANTS], i)
967                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
968                         unit_check_uneeded(other);
969         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE], i)
970                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
971                         unit_check_uneeded(other);
972         SET_FOREACH(other, u->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
973                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
974                         unit_check_uneeded(other);
975 }
976
977 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
978         dual_timestamp ts;
979         bool unexpected;
980
981         assert(u);
982         assert(os < _UNIT_ACTIVE_STATE_MAX);
983         assert(ns < _UNIT_ACTIVE_STATE_MAX);
984
985         /* Note that this is called for all low-level state changes,
986          * even if they might map to the same high-level
987          * UnitActiveState! That means that ns == os is OK an expected
988          * behaviour here. For example: if a mount point is remounted
989          * this function will be called too and the utmp code below
990          * relies on that! */
991
992         dual_timestamp_get(&ts);
993
994         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && !UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
995                 u->meta.inactive_exit_timestamp = ts;
996         else if (!UNIT_IS_INACTIVE_OR_MAINTENANCE(os) && UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
997                 u->meta.inactive_enter_timestamp = ts;
998
999         if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
1000                 u->meta.active_enter_timestamp = ts;
1001         else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
1002                 u->meta.active_exit_timestamp = ts;
1003
1004         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
1005                 cgroup_bonding_trim_list(u->meta.cgroup_bondings, true);
1006
1007         timer_unit_notify(u, ns);
1008         path_unit_notify(u, ns);
1009
1010         if (u->meta.job) {
1011                 unexpected = false;
1012
1013                 if (u->meta.job->state == JOB_WAITING)
1014
1015                         /* So we reached a different state for this
1016                          * job. Let's see if we can run it now if it
1017                          * failed previously due to EAGAIN. */
1018                         job_add_to_run_queue(u->meta.job);
1019
1020                 /* Let's check whether this state change constitutes a
1021                  * finished job, or maybe cotradicts a running job and
1022                  * hence needs to invalidate jobs. */
1023
1024                 switch (u->meta.job->type) {
1025
1026                 case JOB_START:
1027                 case JOB_VERIFY_ACTIVE:
1028
1029                         if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
1030                                 job_finish_and_invalidate(u->meta.job, true);
1031                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
1032                                 unexpected = true;
1033                                 job_finish_and_invalidate(u->meta.job, false);
1034                         }
1035
1036                         break;
1037
1038                 case JOB_RELOAD:
1039                 case JOB_RELOAD_OR_START:
1040
1041                         if (u->meta.job->state == JOB_RUNNING) {
1042                                 if (ns == UNIT_ACTIVE)
1043                                         job_finish_and_invalidate(u->meta.job, true);
1044                                 else if (ns != UNIT_ACTIVATING && ns != UNIT_RELOADING) {
1045                                         unexpected = true;
1046                                         job_finish_and_invalidate(u->meta.job, false);
1047                                 }
1048                         }
1049
1050                         break;
1051
1052                 case JOB_STOP:
1053                 case JOB_RESTART:
1054                 case JOB_TRY_RESTART:
1055
1056                         if (ns == UNIT_INACTIVE || ns == UNIT_MAINTENANCE)
1057                                 job_finish_and_invalidate(u->meta.job, true);
1058                         else if (u->meta.job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
1059                                 unexpected = true;
1060                                 job_finish_and_invalidate(u->meta.job, false);
1061                         }
1062
1063                         break;
1064
1065                 default:
1066                         assert_not_reached("Job type unknown");
1067                 }
1068
1069         } else
1070                 unexpected = true;
1071
1072         /* If this state change happened without being requested by a
1073          * job, then let's retroactively start or stop
1074          * dependencies. We skip that step when deserializing, since
1075          * we don't want to create any additional jobs just because
1076          * something is already activated. */
1077
1078         if (unexpected && u->meta.manager->n_deserializing <= 0) {
1079                 if (UNIT_IS_INACTIVE_OR_DEACTIVATING(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
1080                         retroactively_start_dependencies(u);
1081                 else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
1082                         retroactively_stop_dependencies(u);
1083         }
1084
1085         if (ns != os && ns == UNIT_MAINTENANCE) {
1086                 Iterator i;
1087                 Unit *other;
1088
1089                 SET_FOREACH(other, u->meta.dependencies[UNIT_ON_FAILURE], i)
1090                         manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
1091
1092                 log_notice("Unit %s entered maintenance state.", u->meta.id);
1093         }
1094
1095         /* Some names are special */
1096         if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1097                 if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1098                         /* The bus just might have become available,
1099                          * hence try to connect to it, if we aren't
1100                          * yet connected. */
1101                         bus_init(u->meta.manager);
1102                 }
1103
1104                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1105                         /* The syslog daemon just might have become
1106                          * available, hence try to connect to it, if
1107                          * we aren't yet connected. */
1108                         log_open();
1109
1110                 if (u->meta.type == UNIT_MOUNT)
1111                         /* Another directory became available, let's
1112                          * check if that is enough to write our utmp
1113                          * entry. */
1114                         manager_write_utmp_reboot(u->meta.manager);
1115
1116                 if (u->meta.type == UNIT_TARGET)
1117                         /* A target got activated, maybe this is a runlevel? */
1118                         manager_write_utmp_runlevel(u->meta.manager, u);
1119
1120         } else if (!UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
1121
1122                 if (unit_has_name(u, SPECIAL_SYSLOG_SERVICE))
1123                         /* The syslog daemon might just have
1124                          * terminated, hence try to disconnect from
1125                          * it. */
1126                         log_close_syslog();
1127
1128                 /* We don't care about D-Bus here, since we'll get an
1129                  * asynchronous notification for it anyway. */
1130         }
1131
1132         /* Maybe we finished startup and are now ready for being
1133          * stopped because unneeded? */
1134         unit_check_uneeded(u);
1135
1136         unit_add_to_dbus_queue(u);
1137         unit_add_to_gc_queue(u);
1138 }
1139
1140 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w) {
1141         struct epoll_event ev;
1142
1143         assert(u);
1144         assert(fd >= 0);
1145         assert(w);
1146         assert(w->type == WATCH_INVALID || (w->type == WATCH_FD && w->fd == fd && w->data.unit == u));
1147
1148         zero(ev);
1149         ev.data.ptr = w;
1150         ev.events = events;
1151
1152         if (epoll_ctl(u->meta.manager->epoll_fd,
1153                       w->type == WATCH_INVALID ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,
1154                       fd,
1155                       &ev) < 0)
1156                 return -errno;
1157
1158         w->fd = fd;
1159         w->type = WATCH_FD;
1160         w->data.unit = u;
1161
1162         return 0;
1163 }
1164
1165 void unit_unwatch_fd(Unit *u, Watch *w) {
1166         assert(u);
1167         assert(w);
1168
1169         if (w->type == WATCH_INVALID)
1170                 return;
1171
1172         assert(w->type == WATCH_FD);
1173         assert(w->data.unit == u);
1174         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1175
1176         w->fd = -1;
1177         w->type = WATCH_INVALID;
1178         w->data.unit = NULL;
1179 }
1180
1181 int unit_watch_pid(Unit *u, pid_t pid) {
1182         assert(u);
1183         assert(pid >= 1);
1184
1185         /* Watch a specific PID. We only support one unit watching
1186          * each PID for now. */
1187
1188         return hashmap_put(u->meta.manager->watch_pids, LONG_TO_PTR(pid), u);
1189 }
1190
1191 void unit_unwatch_pid(Unit *u, pid_t pid) {
1192         assert(u);
1193         assert(pid >= 1);
1194
1195         hashmap_remove_value(u->meta.manager->watch_pids, LONG_TO_PTR(pid), u);
1196 }
1197
1198 int unit_watch_timer(Unit *u, usec_t delay, Watch *w) {
1199         struct itimerspec its;
1200         int flags, fd;
1201         bool ours;
1202
1203         assert(u);
1204         assert(w);
1205         assert(w->type == WATCH_INVALID || (w->type == WATCH_UNIT_TIMER && w->data.unit == u));
1206
1207         /* This will try to reuse the old timer if there is one */
1208
1209         if (w->type == WATCH_UNIT_TIMER) {
1210                 assert(w->data.unit == u);
1211                 assert(w->fd >= 0);
1212
1213                 ours = false;
1214                 fd = w->fd;
1215         } else if (w->type == WATCH_INVALID) {
1216
1217                 ours = true;
1218                 if ((fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
1219                         return -errno;
1220         } else
1221                 assert_not_reached("Invalid watch type");
1222
1223         zero(its);
1224
1225         if (delay <= 0) {
1226                 /* Set absolute time in the past, but not 0, since we
1227                  * don't want to disarm the timer */
1228                 its.it_value.tv_sec = 0;
1229                 its.it_value.tv_nsec = 1;
1230
1231                 flags = TFD_TIMER_ABSTIME;
1232         } else {
1233                 timespec_store(&its.it_value, delay);
1234                 flags = 0;
1235         }
1236
1237         /* This will also flush the elapse counter */
1238         if (timerfd_settime(fd, flags, &its, NULL) < 0)
1239                 goto fail;
1240
1241         if (w->type == WATCH_INVALID) {
1242                 struct epoll_event ev;
1243
1244                 zero(ev);
1245                 ev.data.ptr = w;
1246                 ev.events = EPOLLIN;
1247
1248                 if (epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
1249                         goto fail;
1250         }
1251
1252         w->type = WATCH_UNIT_TIMER;
1253         w->fd = fd;
1254         w->data.unit = u;
1255
1256         return 0;
1257
1258 fail:
1259         if (ours)
1260                 close_nointr_nofail(fd);
1261
1262         return -errno;
1263 }
1264
1265 void unit_unwatch_timer(Unit *u, Watch *w) {
1266         assert(u);
1267         assert(w);
1268
1269         if (w->type == WATCH_INVALID)
1270                 return;
1271
1272         assert(w->type == WATCH_UNIT_TIMER);
1273         assert(w->data.unit == u);
1274         assert(w->fd >= 0);
1275
1276         assert_se(epoll_ctl(u->meta.manager->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
1277         close_nointr_nofail(w->fd);
1278
1279         w->fd = -1;
1280         w->type = WATCH_INVALID;
1281         w->data.unit = NULL;
1282 }
1283
1284 bool unit_job_is_applicable(Unit *u, JobType j) {
1285         assert(u);
1286         assert(j >= 0 && j < _JOB_TYPE_MAX);
1287
1288         switch (j) {
1289
1290         case JOB_VERIFY_ACTIVE:
1291         case JOB_START:
1292                 return true;
1293
1294         case JOB_STOP:
1295         case JOB_RESTART:
1296         case JOB_TRY_RESTART:
1297                 return unit_can_start(u);
1298
1299         case JOB_RELOAD:
1300                 return unit_can_reload(u);
1301
1302         case JOB_RELOAD_OR_START:
1303                 return unit_can_reload(u) && unit_can_start(u);
1304
1305         default:
1306                 assert_not_reached("Invalid job type");
1307         }
1308 }
1309
1310 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
1311
1312         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
1313                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
1314                 [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1315                 [UNIT_WANTS] = UNIT_WANTED_BY,
1316                 [UNIT_REQUISITE] = UNIT_REQUIRED_BY,
1317                 [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
1318                 [UNIT_REQUIRED_BY] = _UNIT_DEPENDENCY_INVALID,
1319                 [UNIT_REQUIRED_BY_OVERRIDABLE] = _UNIT_DEPENDENCY_INVALID,
1320                 [UNIT_WANTED_BY] = _UNIT_DEPENDENCY_INVALID,
1321                 [UNIT_CONFLICTS] = UNIT_CONFLICTED_BY,
1322                 [UNIT_CONFLICTED_BY] = UNIT_CONFLICTS,
1323                 [UNIT_BEFORE] = UNIT_AFTER,
1324                 [UNIT_AFTER] = UNIT_BEFORE,
1325                 [UNIT_ON_FAILURE] = _UNIT_DEPENDENCY_INVALID,
1326                 [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
1327                 [UNIT_REFERENCED_BY] = UNIT_REFERENCES
1328         };
1329         int r, q = 0, v = 0, w = 0;
1330
1331         assert(u);
1332         assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
1333         assert(other);
1334
1335         /* We won't allow dependencies on ourselves. We will not
1336          * consider them an error however. */
1337         if (u == other)
1338                 return 0;
1339
1340         if (UNIT_VTABLE(u)->no_requires &&
1341             (d == UNIT_REQUIRES ||
1342              d == UNIT_REQUIRES_OVERRIDABLE ||
1343              d == UNIT_REQUISITE ||
1344              d == UNIT_REQUISITE_OVERRIDABLE)) {
1345                     return -EINVAL;
1346         }
1347
1348         if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
1349                 return r;
1350
1351         if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
1352                 if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
1353                         return r;
1354
1355         if (add_reference)
1356                 if ((r = set_ensure_allocated(&u->meta.dependencies[UNIT_REFERENCES], trivial_hash_func, trivial_compare_func)) < 0 ||
1357                     (r = set_ensure_allocated(&other->meta.dependencies[UNIT_REFERENCED_BY], trivial_hash_func, trivial_compare_func)) < 0)
1358                         return r;
1359
1360         if ((q = set_put(u->meta.dependencies[d], other)) < 0)
1361                 return q;
1362
1363         if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
1364                 if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
1365                         r = v;
1366                         goto fail;
1367                 }
1368
1369         if (add_reference) {
1370                 if ((w = set_put(u->meta.dependencies[UNIT_REFERENCES], other)) < 0) {
1371                         r = w;
1372                         goto fail;
1373                 }
1374
1375                 if ((r = set_put(other->meta.dependencies[UNIT_REFERENCED_BY], u)) < 0)
1376                         goto fail;
1377         }
1378
1379         unit_add_to_dbus_queue(u);
1380         return 0;
1381
1382 fail:
1383         if (q > 0)
1384                 set_remove(u->meta.dependencies[d], other);
1385
1386         if (v > 0)
1387                 set_remove(other->meta.dependencies[inverse_table[d]], u);
1388
1389         if (w > 0)
1390                 set_remove(u->meta.dependencies[UNIT_REFERENCES], other);
1391
1392         return r;
1393 }
1394
1395 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference) {
1396         int r;
1397
1398         assert(u);
1399
1400         if ((r = unit_add_dependency(u, d, other, add_reference)) < 0)
1401                 return r;
1402
1403         if ((r = unit_add_dependency(u, e, other, add_reference)) < 0)
1404                 return r;
1405
1406         return 0;
1407 }
1408
1409 static const char *resolve_template(Unit *u, const char *name, const char*path, char **p) {
1410         char *s;
1411
1412         assert(u);
1413         assert(name || path);
1414
1415         if (!name)
1416                 name = file_name_from_path(path);
1417
1418         if (!unit_name_is_template(name)) {
1419                 *p = NULL;
1420                 return name;
1421         }
1422
1423         if (u->meta.instance)
1424                 s = unit_name_replace_instance(name, u->meta.instance);
1425         else {
1426                 char *i;
1427
1428                 if (!(i = unit_name_to_prefix(u->meta.id)))
1429                         return NULL;
1430
1431                 s = unit_name_replace_instance(name, i);
1432                 free(i);
1433         }
1434
1435         if (!s)
1436                 return NULL;
1437
1438         *p = s;
1439         return s;
1440 }
1441
1442 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1443         Unit *other;
1444         int r;
1445         char *s;
1446
1447         assert(u);
1448         assert(name || path);
1449
1450         if (!(name = resolve_template(u, name, path, &s)))
1451                 return -ENOMEM;
1452
1453         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1454                 goto finish;
1455
1456         r = unit_add_dependency(u, d, other, add_reference);
1457
1458 finish:
1459         free(s);
1460         return r;
1461 }
1462
1463 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1464         Unit *other;
1465         int r;
1466         char *s;
1467
1468         assert(u);
1469         assert(name || path);
1470
1471         if (!(name = resolve_template(u, name, path, &s)))
1472                 return -ENOMEM;
1473
1474         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1475                 goto finish;
1476
1477         r = unit_add_two_dependencies(u, d, e, other, add_reference);
1478
1479 finish:
1480         free(s);
1481         return r;
1482 }
1483
1484 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
1485         Unit *other;
1486         int r;
1487         char *s;
1488
1489         assert(u);
1490         assert(name || path);
1491
1492         if (!(name = resolve_template(u, name, path, &s)))
1493                 return -ENOMEM;
1494
1495         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1496                 goto finish;
1497
1498         r = unit_add_dependency(other, d, u, add_reference);
1499
1500 finish:
1501         free(s);
1502         return r;
1503 }
1504
1505 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
1506         Unit *other;
1507         int r;
1508         char *s;
1509
1510         assert(u);
1511         assert(name || path);
1512
1513         if (!(name = resolve_template(u, name, path, &s)))
1514                 return -ENOMEM;
1515
1516         if ((r = manager_load_unit(u->meta.manager, name, path, NULL, &other)) < 0)
1517                 goto finish;
1518
1519         if ((r = unit_add_two_dependencies(other, d, e, u, add_reference)) < 0)
1520                 goto finish;
1521
1522 finish:
1523         free(s);
1524         return r;
1525 }
1526
1527 int set_unit_path(const char *p) {
1528         char *cwd, *c;
1529         int r;
1530
1531         /* This is mostly for debug purposes */
1532
1533         if (path_is_absolute(p)) {
1534                 if (!(c = strdup(p)))
1535                         return -ENOMEM;
1536         } else {
1537                 if (!(cwd = get_current_dir_name()))
1538                         return -errno;
1539
1540                 r = asprintf(&c, "%s/%s", cwd, p);
1541                 free(cwd);
1542
1543                 if (r < 0)
1544                         return -ENOMEM;
1545         }
1546
1547         if (setenv("SYSTEMD_UNIT_PATH", c, 0) < 0) {
1548                 r = -errno;
1549                 free(c);
1550                 return r;
1551         }
1552
1553         return 0;
1554 }
1555
1556 char *unit_dbus_path(Unit *u) {
1557         char *p, *e;
1558
1559         assert(u);
1560
1561         if (!u->meta.id)
1562                 return NULL;
1563
1564         if (!(e = bus_path_escape(u->meta.id)))
1565                 return NULL;
1566
1567         p = strappend("/org/freedesktop/systemd1/unit/", e);
1568         free(e);
1569
1570         return p;
1571 }
1572
1573 int unit_add_cgroup(Unit *u, CGroupBonding *b) {
1574         CGroupBonding *l;
1575         int r;
1576
1577         assert(u);
1578         assert(b);
1579
1580         assert(b->path);
1581
1582         if (!b->controller)
1583                 if (!(b->controller = strdup(SYSTEMD_CGROUP_CONTROLLER)))
1584                         return -ENOMEM;
1585
1586         /* Ensure this hasn't been added yet */
1587         assert(!b->unit);
1588
1589         l = hashmap_get(u->meta.manager->cgroup_bondings, b->path);
1590         LIST_PREPEND(CGroupBonding, by_path, l, b);
1591
1592         if ((r = hashmap_replace(u->meta.manager->cgroup_bondings, b->path, l)) < 0) {
1593                 LIST_REMOVE(CGroupBonding, by_path, l, b);
1594                 return r;
1595         }
1596
1597         LIST_PREPEND(CGroupBonding, by_unit, u->meta.cgroup_bondings, b);
1598         b->unit = u;
1599
1600         return 0;
1601 }
1602
1603 static char *default_cgroup_path(Unit *u) {
1604         char *p;
1605         int r;
1606
1607         assert(u);
1608
1609         if (u->meta.instance) {
1610                 char *t;
1611
1612                 if (!(t = unit_name_template(u->meta.id)))
1613                         return NULL;
1614
1615                 r = asprintf(&p, "%s/%s/%s", u->meta.manager->cgroup_hierarchy, t, u->meta.instance);
1616                 free(t);
1617         } else
1618                 r = asprintf(&p, "%s/%s", u->meta.manager->cgroup_hierarchy, u->meta.id);
1619
1620         return r < 0 ? NULL : p;
1621 }
1622
1623 int unit_add_cgroup_from_text(Unit *u, const char *name) {
1624         char *controller = NULL, *path = NULL;
1625         CGroupBonding *b = NULL;
1626         int r;
1627
1628         assert(u);
1629         assert(name);
1630
1631         if ((r = cg_split_spec(name, &controller, &path)) < 0)
1632                 return r;
1633
1634         if (!path)
1635                 path = default_cgroup_path(u);
1636
1637         if (!controller)
1638                 controller = strdup(SYSTEMD_CGROUP_CONTROLLER);
1639
1640         if (!path || !controller) {
1641                 free(path);
1642                 free(controller);
1643
1644                 return -ENOMEM;
1645         }
1646
1647         if (cgroup_bonding_find_list(u->meta.cgroup_bondings, controller)) {
1648                 r = -EEXIST;
1649                 goto fail;
1650         }
1651
1652         if (!(b = new0(CGroupBonding, 1))) {
1653                 r = -ENOMEM;
1654                 goto fail;
1655         }
1656
1657         b->controller = controller;
1658         b->path = path;
1659         b->only_us = false;
1660         b->clean_up = false;
1661
1662         if ((r = unit_add_cgroup(u, b)) < 0)
1663                 goto fail;
1664
1665         return 0;
1666
1667 fail:
1668         free(path);
1669         free(controller);
1670         free(b);
1671
1672         return r;
1673 }
1674
1675 int unit_add_default_cgroup(Unit *u) {
1676         CGroupBonding *b;
1677         int r = -ENOMEM;
1678
1679         assert(u);
1680
1681         /* Adds in the default cgroup data, if it wasn't specified yet */
1682
1683         if (unit_get_default_cgroup(u))
1684                 return 0;
1685
1686         if (!(b = new0(CGroupBonding, 1)))
1687                 return -ENOMEM;
1688
1689         if (!(b->path = default_cgroup_path(u)))
1690                 goto fail;
1691
1692         b->clean_up = true;
1693         b->only_us = true;
1694
1695         if ((r = unit_add_cgroup(u, b)) < 0)
1696                 goto fail;
1697
1698         return 0;
1699
1700 fail:
1701         free(b->path);
1702         free(b->controller);
1703         free(b);
1704
1705         return r;
1706 }
1707
1708 CGroupBonding* unit_get_default_cgroup(Unit *u) {
1709         assert(u);
1710
1711         return cgroup_bonding_find_list(u->meta.cgroup_bondings, SYSTEMD_CGROUP_CONTROLLER);
1712 }
1713
1714 int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
1715         char *t;
1716         int r;
1717
1718         assert(u);
1719         assert(type);
1720         assert(_found);
1721
1722         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1723                 return -ENOMEM;
1724
1725         assert(!unit_has_name(u, t));
1726
1727         r = manager_load_unit(u->meta.manager, t, NULL, NULL, _found);
1728         free(t);
1729
1730         assert(r < 0 || *_found != u);
1731
1732         return r;
1733 }
1734
1735 int unit_get_related_unit(Unit *u, const char *type, Unit **_found) {
1736         Unit *found;
1737         char *t;
1738
1739         assert(u);
1740         assert(type);
1741         assert(_found);
1742
1743         if (!(t = unit_name_change_suffix(u->meta.id, type)))
1744                 return -ENOMEM;
1745
1746         assert(!unit_has_name(u, t));
1747
1748         found = manager_get_unit(u->meta.manager, t);
1749         free(t);
1750
1751         if (!found)
1752                 return -ENOENT;
1753
1754         *_found = found;
1755         return 0;
1756 }
1757
1758 static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
1759         Unit *u = userdata;
1760         assert(u);
1761
1762         return unit_name_to_prefix_and_instance(u->meta.id);
1763 }
1764
1765 static char *specifier_prefix(char specifier, void *data, void *userdata) {
1766         Unit *u = userdata;
1767         assert(u);
1768
1769         return unit_name_to_prefix(u->meta.id);
1770 }
1771
1772 static char *specifier_prefix_unescaped(char specifier, void *data, void *userdata) {
1773         Unit *u = userdata;
1774         char *p, *r;
1775
1776         assert(u);
1777
1778         if (!(p = unit_name_to_prefix(u->meta.id)))
1779                 return NULL;
1780
1781         r = unit_name_unescape(p);
1782         free(p);
1783
1784         return r;
1785 }
1786
1787 static char *specifier_instance_unescaped(char specifier, void *data, void *userdata) {
1788         Unit *u = userdata;
1789         assert(u);
1790
1791         if (u->meta.instance)
1792                 return unit_name_unescape(u->meta.instance);
1793
1794         return strdup("");
1795 }
1796
1797 char *unit_name_printf(Unit *u, const char* format) {
1798
1799         /*
1800          * This will use the passed string as format string and
1801          * replace the following specifiers:
1802          *
1803          * %n: the full id of the unit                 (foo@bar.waldo)
1804          * %N: the id of the unit without the suffix   (foo@bar)
1805          * %p: the prefix                              (foo)
1806          * %i: the instance                            (bar)
1807          */
1808
1809         const Specifier table[] = {
1810                 { 'n', specifier_string,              u->meta.id },
1811                 { 'N', specifier_prefix_and_instance, NULL },
1812                 { 'p', specifier_prefix,              NULL },
1813                 { 'i', specifier_string,              u->meta.instance },
1814                 { 0, NULL, NULL }
1815         };
1816
1817         assert(u);
1818         assert(format);
1819
1820         return specifier_printf(format, table, u);
1821 }
1822
1823 char *unit_full_printf(Unit *u, const char *format) {
1824
1825         /* This is similar to unit_name_printf() but also supports
1826          * unescaping */
1827
1828         const Specifier table[] = {
1829                 { 'n', specifier_string,              u->meta.id },
1830                 { 'N', specifier_prefix_and_instance, NULL },
1831                 { 'p', specifier_prefix,              NULL },
1832                 { 'P', specifier_prefix_unescaped,    NULL },
1833                 { 'i', specifier_string,              u->meta.instance },
1834                 { 'I', specifier_instance_unescaped,  NULL },
1835                 { 0, NULL, NULL }
1836         };
1837
1838         assert(u);
1839         assert(format);
1840
1841         return specifier_printf(format, table, u);
1842 }
1843
1844 char **unit_full_printf_strv(Unit *u, char **l) {
1845         size_t n;
1846         char **r, **i, **j;
1847
1848         /* Applies unit_full_printf to every entry in l */
1849
1850         assert(u);
1851
1852         n = strv_length(l);
1853         if (!(r = new(char*, n+1)))
1854                 return NULL;
1855
1856         for (i = l, j = r; *i; i++, j++)
1857                 if (!(*j = unit_full_printf(u, *i)))
1858                         goto fail;
1859
1860         *j = NULL;
1861         return r;
1862
1863 fail:
1864         j--;
1865         while (j >= r)
1866                 free(*j);
1867
1868         free(r);
1869
1870         return NULL;
1871 }
1872
1873 int unit_watch_bus_name(Unit *u, const char *name) {
1874         assert(u);
1875         assert(name);
1876
1877         /* Watch a specific name on the bus. We only support one unit
1878          * watching each name for now. */
1879
1880         return hashmap_put(u->meta.manager->watch_bus, name, u);
1881 }
1882
1883 void unit_unwatch_bus_name(Unit *u, const char *name) {
1884         assert(u);
1885         assert(name);
1886
1887         hashmap_remove_value(u->meta.manager->watch_bus, name, u);
1888 }
1889
1890 bool unit_can_serialize(Unit *u) {
1891         assert(u);
1892
1893         return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
1894 }
1895
1896 int unit_serialize(Unit *u, FILE *f, FDSet *fds) {
1897         int r;
1898
1899         assert(u);
1900         assert(f);
1901         assert(fds);
1902
1903         if (!unit_can_serialize(u))
1904                 return 0;
1905
1906         if ((r = UNIT_VTABLE(u)->serialize(u, f, fds)) < 0)
1907                 return r;
1908
1909         if (u->meta.job)
1910                 unit_serialize_item(u, f, "job", job_type_to_string(u->meta.job->type));
1911
1912         /* End marker */
1913         fputc('\n', f);
1914         return 0;
1915 }
1916
1917 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
1918         va_list ap;
1919
1920         assert(u);
1921         assert(f);
1922         assert(key);
1923         assert(format);
1924
1925         fputs(key, f);
1926         fputc('=', f);
1927
1928         va_start(ap, format);
1929         vfprintf(f, format, ap);
1930         va_end(ap);
1931
1932         fputc('\n', f);
1933 }
1934
1935 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
1936         assert(u);
1937         assert(f);
1938         assert(key);
1939         assert(value);
1940
1941         fprintf(f, "%s=%s\n", key, value);
1942 }
1943
1944 int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
1945         int r;
1946
1947         assert(u);
1948         assert(f);
1949         assert(fds);
1950
1951         if (!unit_can_serialize(u))
1952                 return 0;
1953
1954         for (;;) {
1955                 char line[1024], *l, *v;
1956                 size_t k;
1957
1958                 if (!fgets(line, sizeof(line), f)) {
1959                         if (feof(f))
1960                                 return 0;
1961                         return -errno;
1962                 }
1963
1964                 l = strstrip(line);
1965
1966                 /* End marker */
1967                 if (l[0] == 0)
1968                         return 0;
1969
1970                 k = strcspn(l, "=");
1971
1972                 if (l[k] == '=') {
1973                         l[k] = 0;
1974                         v = l+k+1;
1975                 } else
1976                         v = l+k;
1977
1978                 if (streq(l, "job")) {
1979                         JobType type;
1980
1981                         if ((type = job_type_from_string(v)) < 0)
1982                                 log_debug("Failed to parse job type value %s", v);
1983                         else
1984                                 u->meta.deserialized_job = type;
1985
1986                         continue;
1987                 }
1988
1989                 if ((r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds)) < 0)
1990                         return r;
1991         }
1992 }
1993
1994 int unit_add_node_link(Unit *u, const char *what, bool wants) {
1995         Unit *device;
1996         char *e;
1997         int r;
1998
1999         assert(u);
2000
2001         if (!what)
2002                 return 0;
2003
2004         /* Adds in links to the device node that this unit is based on */
2005
2006         if (!is_device_path(what))
2007                 return 0;
2008
2009         if (!(e = unit_name_build_escape(what+1, NULL, ".device")))
2010                 return -ENOMEM;
2011
2012         r = manager_load_unit(u->meta.manager, e, NULL, NULL, &device);
2013         free(e);
2014
2015         if (r < 0)
2016                 return r;
2017
2018         if ((r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_REQUIRES, device, true)) < 0)
2019                 return r;
2020
2021         if (wants)
2022                 if ((r = unit_add_dependency(device, UNIT_WANTS, u, false)) < 0)
2023                         return r;
2024
2025         return 0;
2026 }
2027
2028 int unit_coldplug(Unit *u) {
2029         int r;
2030
2031         assert(u);
2032
2033         if (UNIT_VTABLE(u)->coldplug)
2034                 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
2035                         return r;
2036
2037         if (u->meta.deserialized_job >= 0) {
2038                 if ((r = manager_add_job(u->meta.manager, u->meta.deserialized_job, u, JOB_FAIL, false, NULL, NULL)) < 0)
2039                         return r;
2040
2041                 u->meta.deserialized_job = _JOB_TYPE_INVALID;
2042         }
2043
2044         return 0;
2045 }
2046
2047 void unit_status_printf(Unit *u, const char *format, ...) {
2048         va_list ap;
2049
2050         assert(u);
2051         assert(format);
2052
2053         if (!UNIT_VTABLE(u)->show_status)
2054                 return;
2055
2056         if (u->meta.manager->running_as != MANAGER_SYSTEM)
2057                 return;
2058
2059         if (!u->meta.manager->show_status)
2060                 return;
2061
2062         if (!manager_is_booting_or_shutting_down(u->meta.manager))
2063                 return;
2064
2065         va_start(ap, format);
2066         status_vprintf(format, ap);
2067         va_end(ap);
2068 }
2069
2070 bool unit_need_daemon_reload(Unit *u) {
2071         struct stat st;
2072
2073         assert(u);
2074
2075         if (!u->meta.fragment_path)
2076                 return false;
2077
2078         zero(st);
2079         if (stat(u->meta.fragment_path, &st) < 0)
2080                 /* What, cannot access this anymore? */
2081                 return true;
2082
2083         return
2084                 u->meta.fragment_mtime &&
2085                 timespec_load(&st.st_mtim) != u->meta.fragment_mtime;
2086 }
2087
2088 void unit_reset_maintenance(Unit *u) {
2089         assert(u);
2090
2091         if (UNIT_VTABLE(u)->reset_maintenance)
2092                 UNIT_VTABLE(u)->reset_maintenance(u);
2093 }
2094
2095 Unit *unit_following(Unit *u) {
2096         assert(u);
2097
2098         if (UNIT_VTABLE(u)->following)
2099                 return UNIT_VTABLE(u)->following(u);
2100
2101         return NULL;
2102 }
2103
2104 static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
2105         [UNIT_SERVICE] = "service",
2106         [UNIT_TIMER] = "timer",
2107         [UNIT_SOCKET] = "socket",
2108         [UNIT_TARGET] = "target",
2109         [UNIT_DEVICE] = "device",
2110         [UNIT_MOUNT] = "mount",
2111         [UNIT_AUTOMOUNT] = "automount",
2112         [UNIT_SNAPSHOT] = "snapshot",
2113         [UNIT_SWAP] = "swap"
2114 };
2115
2116 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
2117
2118 static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
2119         [UNIT_STUB] = "stub",
2120         [UNIT_LOADED] = "loaded",
2121         [UNIT_FAILED] = "failed",
2122         [UNIT_MERGED] = "merged"
2123 };
2124
2125 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
2126
2127 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
2128         [UNIT_ACTIVE] = "active",
2129         [UNIT_RELOADING] = "reloading",
2130         [UNIT_INACTIVE] = "inactive",
2131         [UNIT_MAINTENANCE] = "maintenance",
2132         [UNIT_ACTIVATING] = "activating",
2133         [UNIT_DEACTIVATING] = "deactivating"
2134 };
2135
2136 DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
2137
2138 static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
2139         [UNIT_REQUIRES] = "Requires",
2140         [UNIT_REQUIRES_OVERRIDABLE] = "RequiresOverridable",
2141         [UNIT_WANTS] = "Wants",
2142         [UNIT_REQUISITE] = "Requisite",
2143         [UNIT_REQUISITE_OVERRIDABLE] = "RequisiteOverridable",
2144         [UNIT_REQUIRED_BY] = "RequiredBy",
2145         [UNIT_REQUIRED_BY_OVERRIDABLE] = "RequiredByOverridable",
2146         [UNIT_WANTED_BY] = "WantedBy",
2147         [UNIT_CONFLICTS] = "Conflicts",
2148         [UNIT_CONFLICTED_BY] = "ConflictedBy",
2149         [UNIT_BEFORE] = "Before",
2150         [UNIT_AFTER] = "After",
2151         [UNIT_REFERENCES] = "References",
2152         [UNIT_REFERENCED_BY] = "ReferencedBy",
2153         [UNIT_ON_FAILURE] = "OnFailure"
2154 };
2155
2156 DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
2157
2158 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
2159         [KILL_CONTROL_GROUP] = "control-group",
2160         [KILL_PROCESS_GROUP] = "process-group",
2161         [KILL_PROCESS] = "process",
2162         [KILL_NONE] = "none"
2163 };
2164
2165 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);