summaryrefslogtreecommitdiff
path: root/src/core/unit.h
blob: be6abaff98e8fcb5ca63ecb948842e832264ea10 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#pragma once

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>

typedef struct Unit Unit;
typedef struct UnitVTable UnitVTable;
typedef enum UnitActiveState UnitActiveState;
typedef enum UnitDependency UnitDependency;
typedef struct UnitRef UnitRef;
typedef struct UnitStatusMessageFormats UnitStatusMessageFormats;

#include "set.h"
#include "util.h"
#include "list.h"
#include "socket-util.h"
#include "execute.h"
#include "cgroup.h"
#include "condition.h"
#include "install.h"
#include "unit-name.h"

enum UnitActiveState {
        UNIT_ACTIVE,
        UNIT_RELOADING,
        UNIT_INACTIVE,
        UNIT_FAILED,
        UNIT_ACTIVATING,
        UNIT_DEACTIVATING,
        _UNIT_ACTIVE_STATE_MAX,
        _UNIT_ACTIVE_STATE_INVALID = -1
};

static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
        return t == UNIT_ACTIVE || t == UNIT_RELOADING;
}

static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
        return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_RELOADING;
}

static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
        return t == UNIT_INACTIVE || t == UNIT_FAILED || t == UNIT_DEACTIVATING;
}

static inline bool UNIT_IS_INACTIVE_OR_FAILED(UnitActiveState t) {
        return t == UNIT_INACTIVE || t == UNIT_FAILED;
}

enum UnitDependency {
        /* Positive dependencies */
        UNIT_REQUIRES,
        UNIT_REQUIRES_OVERRIDABLE,
        UNIT_REQUISITE,
        UNIT_REQUISITE_OVERRIDABLE,
        UNIT_WANTS,
        UNIT_BINDS_TO,
        UNIT_PART_OF,

        /* Inverse of the above */
        UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
        UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'requires_overridable' and 'requisite_overridable' is 'soft_required_by' */
        UNIT_WANTED_BY,               /* inverse of 'wants' */
        UNIT_BOUND_BY,                /* inverse of 'binds_to' */
        UNIT_CONSISTS_OF,             /* inverse of 'part_of' */

        /* Negative dependencies */
        UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */
        UNIT_CONFLICTED_BY,

        /* Order */
        UNIT_BEFORE,                  /* inverse of 'before' is 'after' and vice versa */
        UNIT_AFTER,

        /* On Failure */
        UNIT_ON_FAILURE,

        /* Triggers (i.e. a socket triggers a service) */
        UNIT_TRIGGERS,
        UNIT_TRIGGERED_BY,

        /* Propagate reloads */
        UNIT_PROPAGATES_RELOAD_TO,
        UNIT_RELOAD_PROPAGATED_FROM,

        /* Reference information for GC logic */
        UNIT_REFERENCES,              /* Inverse of 'references' is 'referenced_by' */
        UNIT_REFERENCED_BY,

        _UNIT_DEPENDENCY_MAX,
        _UNIT_DEPENDENCY_INVALID = -1
};

#include "manager.h"
#include "job.h"

struct UnitRef {
        /* Keeps tracks of references to a unit. This is useful so
         * that we can merge two units if necessary and correct all
         * references to them */

        Unit* unit;
        LIST_FIELDS(UnitRef, refs);
};

struct Unit {
        Manager *manager;

        UnitType type;
        UnitLoadState load_state;
        Unit *merged_into;

        char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
        char *instance;

        Set *names;
        Set *dependencies[_UNIT_DEPENDENCY_MAX];

        char **requires_mounts_for;

        char *description;
        char **documentation;

        char *fragment_path; /* if loaded from a config file this is the primary path to it */
        char *source_path; /* if converted, the source file */
        char **dropin_paths;
        usec_t fragment_mtime;
        usec_t source_mtime;
        usec_t dropin_mtime;

        /* If there is something to do with this unit, then this is the installed job for it */
        Job *job;

        /* JOB_NOP jobs are special and can be installed without disturbing the real job. */
        Job *nop_job;

        usec_t job_timeout;

        /* References to this */
        LIST_HEAD(UnitRef, refs);

        /* Conditions to check */
        LIST_HEAD(Condition, conditions);

        dual_timestamp condition_timestamp;

        dual_timestamp inactive_exit_timestamp;
        dual_timestamp active_enter_timestamp;
        dual_timestamp active_exit_timestamp;
        dual_timestamp inactive_enter_timestamp;

        /* Counterparts in the cgroup filesystem */
        char *cgroup_path;
        bool cgroup_realized;
        CGroupControllerMask cgroup_mask;

        UnitRef slice;

        /* Per type list */
        LIST_FIELDS(Unit, units_by_type);

        /* All units which have requires_mounts_for set */
        LIST_FIELDS(Unit, has_requires_mounts_for);

        /* Load queue */
        LIST_FIELDS(Unit, load_queue);

        /* D-Bus queue */
        LIST_FIELDS(Unit, dbus_queue);

        /* Cleanup queue */
        LIST_FIELDS(Unit, cleanup_queue);

        /* GC queue */
        LIST_FIELDS(Unit, gc_queue);

        /* CGroup realize members queue */
        LIST_FIELDS(Unit, cgroup_queue);

        /* Used during GC sweeps */
        unsigned gc_marker;

        /* When deserializing, temporarily store the job type for this
         * unit here, if there was a job scheduled.
         * Only for deserializing from a legacy version. New style uses full
         * serialized jobs. */
        int deserialized_job; /* This is actually of type JobType */

        /* Error code when we didn't manage to load the unit (negative) */
        int load_error;

        /* Cached unit file state */
        UnitFileState unit_file_state;

        /* Garbage collect us we nobody wants or requires us anymore */
        bool stop_when_unneeded;

        /* Create default dependencies */
        bool default_dependencies;

        /* Refuse manual starting, allow starting only indirectly via dependency. */
        bool refuse_manual_start;

        /* Don't allow the user to stop this unit manually, allow stopping only indirectly via dependency. */
        bool refuse_manual_stop;

        /* Allow isolation requests */
        bool allow_isolate;

        /* Isolate OnFailure unit */
        bool on_failure_isolate;

        /* Ignore this unit when isolating */
        bool ignore_on_isolate;

        /* Ignore this unit when snapshotting */
        bool ignore_on_snapshot;

        /* Did the last condition check succeed? */
        bool condition_result;

        bool in_load_queue:1;
        bool in_dbus_queue:1;
        bool in_cleanup_queue:1;
        bool in_gc_queue:1;
        bool in_cgroup_queue:1;

        bool sent_dbus_new_signal:1;

        bool no_gc:1;

        bool in_audit:1;
};

struct UnitStatusMessageFormats {
        const char *starting_stopping[2];
        const char *finished_start_job[_JOB_RESULT_MAX];
        const char *finished_stop_job[_JOB_RESULT_MAX];
};

typedef enum UnitSetPropertiesMode {
        UNIT_CHECK = 0,
        UNIT_RUNTIME = 1,
        UNIT_PERSISTENT = 2,
} UnitSetPropertiesMode;

#include "service.h"
#include "timer.h"
#include "socket.h"
#include "target.h"
#include "device.h"
#include "mount.h"
#include "automount.h"
#include "snapshot.h"
#include "swap.h"
#include "path.h"
#include "slice.h"

struct UnitVTable {
        /* How much memory does an object of this unit type need */
        size_t object_size;

        /* If greater than 0, the offset into the object where
         * ExecContext is found, if the unit type has that */
        size_t exec_context_offset;

        /* If greater than 0, the offset into the object where
         * CGroupContext is found, if the unit type has that */
        size_t cgroup_context_offset;

        /* The name of the configuration file section with the private settings of this unit*/
        const char *private_section;

        /* Config file sections this unit type understands, separated
         * by NUL chars */
        const char *sections;

        /* This should reset all type-specific variables. This should
         * not allocate memory, and is called with zero-initialized
         * data. It should hence only initialize variables that need
         * to be set != 0. */
        void (*init)(Unit *u);

        /* This should free all type-specific variables. It should be
         * idempotent. */
        void (*done)(Unit *u);

        /* Actually load data from disk. This may fail, and should set
         * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
         * UNIT_STUB if no configuration could be found. */
        int (*load)(Unit *u);

        /* If a lot of units got created via enumerate(), this is
         * where to actually set the state and call unit_notify(). */
        int (*coldplug)(Unit *u);

        void (*dump)(Unit *u, FILE *f, const char *prefix);

        int (*start)(Unit *u);
        int (*stop)(Unit *u);
        int (*reload)(Unit *u);

        int (*kill)(Unit *u, KillWho w, int signo, DBusError *error);

        bool (*can_reload)(Unit *u);

        /* Write all data that cannot be restored from other sources
         * away using unit_serialize_item() */
        int (*serialize)(Unit *u, FILE *f, FDSet *fds);

        /* Restore one item from the serialization */
        int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);

        /* Try to match up fds with what we need for this unit */
        int (*distribute_fds)(Unit *u, FDSet *fds);

        /* Boils down the more complex internal state of this unit to
         * a simpler one that the engine can understand */
        UnitActiveState (*active_state)(Unit *u);

        /* Returns the substate specific to this unit type as
         * string. This is purely information so that we can give the
         * user a more fine grained explanation in which actual state a
         * unit is in. */
        const char* (*sub_state_to_string)(Unit *u);

        /* Return true when there is reason to keep this entry around
         * even nothing references it and it isn't active in any
         * way */
        bool (*check_gc)(Unit *u);

        /* Return true when this unit is suitable for snapshotting */
        bool (*check_snapshot)(Unit *u);

        void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
        void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
        void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);

        /* Reset failed state if we are in failed state */
        void (*reset_failed)(Unit *u);

        /* Called whenever any of the cgroups this unit watches for
         * ran empty */
        void (*notify_cgroup_empty)(Unit *u);

        /* Called whenever a process of this unit sends us a message */
        void (*notify_message)(Unit *u, pid_t pid, char **tags);

        /* Called whenever a name this Unit registered for comes or
         * goes away. */
        void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, const char *new_owner);

        /* Called whenever a bus PID lookup finishes */
        void (*bus_query_pid_done)(Unit *u, const char *name, pid_t pid);

        /* Called for each message received on the bus */
        DBusHandlerResult (*bus_message_handler)(Unit *u, DBusConnection *c, DBusMessage *message);

        /* Called for each property that is being set */
        int (*bus_set_property)(Unit *u, const char *name, DBusMessageIter *i, UnitSetPropertiesMode mode, DBusError *error);

        /* Called after at least one property got changed to apply the necessary change */
        int (*bus_commit_properties)(Unit *u);

        /* Return the unit this unit is following */
        Unit *(*following)(Unit *u);

        /* Return the set of units that are following each other */
        int (*following_set)(Unit *u, Set **s);

        /* Invoked each time a unit this unit is triggering changes
         * state or gains/loses a job */
        void (*trigger_notify)(Unit *u, Unit *trigger);

        /* Called whenever CLOCK_REALTIME made a jump */
        void (*time_change)(Unit *u);

        /* This is called for each unit type and should be used to
         * enumerate existing devices and load them. However,
         * everything that is loaded here should still stay in
         * inactive state. It is the job of the coldplug() call above
         * to put the units into the initial state.  */
        int (*enumerate)(Manager *m);

        /* Type specific cleanups. */
        void (*shutdown)(Manager *m);

        /* When sending out PropertiesChanged signal, which properties
         * shall be invalidated? This is a NUL separated list of
         * strings, to minimize relocations a little. */
        const char *bus_invalidating_properties;

        /* The interface name */
        const char *bus_interface;

        UnitStatusMessageFormats status_message_formats;

        /* Can units of this type have multiple names? */
        bool no_alias:1;

        /* Instances make no sense for this type */
        bool no_instances:1;

        /* Exclude from automatic gc */
        bool no_gc:1;
};

extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];

#define UNIT_VTABLE(u) unit_vtable[(u)->type]

/* For casting a unit into the various unit types */
#define DEFINE_CAST(UPPERCASE, MixedCase)                               \
        static inline MixedCase* UPPERCASE(Unit *u) {                   \
                if (_unlikely_(!u || u->type != UNIT_##UPPERCASE))      \
                        return NULL;                                    \
                                                                        \
                return (MixedCase*) u;                                  \
        }

/* For casting the various unit types into a unit */
#define UNIT(u) (&(u)->meta)

#define UNIT_TRIGGER(u) ((Unit*) set_first((u)->dependencies[UNIT_TRIGGERS]))

DEFINE_CAST(SOCKET, Socket);
DEFINE_CAST(TIMER, Timer);
DEFINE_CAST(SERVICE, Service);
DEFINE_CAST(TARGET, Target);
DEFINE_CAST(DEVICE, Device);
DEFINE_CAST(MOUNT, Mount);
DEFINE_CAST(AUTOMOUNT, Automount);
DEFINE_CAST(SNAPSHOT, Snapshot);
DEFINE_CAST(SWAP, Swap);
DEFINE_CAST(PATH, Path);
DEFINE_CAST(SLICE, Slice);

Unit *unit_new(Manager *m, size_t size);
void unit_free(Unit *u);

int unit_add_name(Unit *u, const char *name);

int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference);
int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference);

int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);

int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);

int unit_add_exec_dependencies(Unit *u, ExecContext *c);

int unit_choose_id(Unit *u, const char *name);
int unit_set_description(Unit *u, const char *description);

bool unit_check_gc(Unit *u);

void unit_add_to_load_queue(Unit *u);
void unit_add_to_dbus_queue(Unit *u);
void unit_add_to_cleanup_queue(Unit *u);
void unit_add_to_gc_queue(Unit *u);

int unit_merge(Unit *u, Unit *other);
int unit_merge_by_name(Unit *u, const char *other);

Unit *unit_follow_merge(Unit *u) _pure_;

int unit_load_fragment_and_dropin(Unit *u);
int unit_load_fragment_and_dropin_optional(Unit *u);
int unit_load(Unit *unit);

int unit_add_default_slice(Unit *u);

const char *unit_description(Unit *u) _pure_;

bool unit_has_name(Unit *u, const char *name);

UnitActiveState unit_active_state(Unit *u);

const char* unit_sub_state_to_string(Unit *u);

void unit_dump(Unit *u, FILE *f, const char *prefix);

bool unit_can_reload(Unit *u) _pure_;
bool unit_can_start(Unit *u) _pure_;
bool unit_can_isolate(Unit *u) _pure_;

int unit_start(Unit *u);
int unit_stop(Unit *u);
int unit_reload(Unit *u);

int unit_kill(Unit *u, KillWho w, int signo, DBusError *error);
int unit_kill_common(Unit *u, KillWho who, int signo, pid_t main_pid, pid_t control_pid, DBusError *error);

void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_success);

int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
void unit_unwatch_fd(Unit *u, Watch *w);

int unit_watch_pid(Unit *u, pid_t pid);
void unit_unwatch_pid(Unit *u, pid_t pid);

int unit_watch_timer(Unit *u, clockid_t, bool relative, usec_t usec, Watch *w);
void unit_unwatch_timer(Unit *u, Watch *w);

int unit_watch_bus_name(Unit *u, const char *name);
void unit_unwatch_bus_name(Unit *u, const char *name);

bool unit_job_is_applicable(Unit *u, JobType j);

int set_unit_path(const char *p);

char *unit_dbus_path(Unit *u);

int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
int unit_get_related_unit(Unit *u, const char *type, Unit **_found);

bool unit_can_serialize(Unit *u) _pure_;
int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs);
void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *value, ...) _printf_attr_(4,5);
void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value);
int unit_deserialize(Unit *u, FILE *f, FDSet *fds);

int unit_add_node_link(Unit *u, const char *what, bool wants);

int unit_coldplug(Unit *u);

void unit_status_printf(Unit *u, const char *status, const char *unit_status_msg_format) _printf_attr_(3, 0);

bool unit_need_daemon_reload(Unit *u);

void unit_reset_failed(Unit *u);

Unit *unit_following(Unit *u);

const char *unit_slice_name(Unit *u);

bool unit_stop_pending(Unit *u) _pure_;
bool unit_inactive_or_pending(Unit *u) _pure_;
bool unit_active_or_pending(Unit *u);

int unit_add_default_target_dependency(Unit *u, Unit *target);

char *unit_default_cgroup_path(Unit *u);

int unit_following_set(Unit *u, Set **s);

void unit_start_on_failure(Unit *u);
void unit_trigger_notify(Unit *u);

bool unit_condition_test(Unit *u);

UnitFileState unit_get_unit_file_state(Unit *u);

Unit* unit_ref_set(UnitRef *ref, Unit *u);
void unit_ref_unset(UnitRef *ref);

#define UNIT_DEREF(ref) ((ref).unit)
#define UNIT_ISSET(ref) (!!(ref).unit)

int unit_add_one_mount_link(Unit *u, Mount *m);
int unit_add_mount_links(Unit *u);

int unit_exec_context_defaults(Unit *u, ExecContext *c);

ExecContext *unit_get_exec_context(Unit *u) _pure_;
CGroupContext *unit_get_cgroup_context(Unit *u) _pure_;

int unit_write_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data);
int unit_write_drop_in_private_section(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data);
int unit_remove_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name);

int unit_kill_context(Unit *u, KillContext *c, bool sigkill, pid_t main_pid, pid_t control_pid, bool main_pid_alien);

const char *unit_active_state_to_string(UnitActiveState i) _const_;
UnitActiveState unit_active_state_from_string(const char *s) _pure_;

const char *unit_dependency_to_string(UnitDependency i) _const_;
UnitDependency unit_dependency_from_string(const char *s) _pure_;

/* Macros which append UNIT= or USER_UNIT= to the message */

#define log_full_unit(level, unit, ...) log_meta_object(level, __FILE__, __LINE__, __func__, getpid() == 1 ? "UNIT=" : "USER_UNIT=", unit, __VA_ARGS__)
#define log_debug_unit(unit, ...)       log_full_unit(LOG_DEBUG, unit, __VA_ARGS__)
#define log_info_unit(unit, ...)        log_full_unit(LOG_INFO, unit, __VA_ARGS__)
#define log_notice_unit(unit, ...)      log_full_unit(LOG_NOTICE, unit, __VA_ARGS__)
#define log_warning_unit(unit, ...)     log_full_unit(LOG_WARNING, unit, __VA_ARGS__)
#define log_error_unit(unit, ...)       log_full_unit(LOG_ERR, unit, __VA_ARGS__)

#define log_struct_unit(level, unit, ...) log_struct(level, getpid() == 1 ? "UNIT=%s" : "USER_UNIT=%s", unit, __VA_ARGS__)