summaryrefslogtreecommitdiff
path: root/unit.h
blob: 72a742ca4a1f4db24b5580b9f0005d722a4da87e (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
/*-*- Mode: C; c-basic-offset: 8 -*-*/

#ifndef foounithfoo
#define foounithfoo

/***
  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 General Public License as published by
  the Free Software Foundation; either version 2 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
  General Public License for more details.

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

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

typedef union Unit Unit;
typedef struct Meta Meta;
typedef struct UnitVTable UnitVTable;
typedef enum UnitType UnitType;
typedef enum UnitLoadState UnitLoadState;
typedef enum UnitActiveState UnitActiveState;
typedef enum UnitDependency UnitDependency;

#include "set.h"
#include "util.h"
#include "list.h"
#include "socket-util.h"
#include "execute.h"

#define UNIT_NAME_MAX 128
#define DEFAULT_TIMEOUT_USEC (20*USEC_PER_SEC)
#define DEFAULT_RESTART_USEC (100*USEC_PER_MSEC)

typedef enum KillMode {
        KILL_CONTROL_GROUP = 0,
        KILL_PROCESS_GROUP,
        KILL_PROCESS,
        KILL_NONE,
        _KILL_MODE_MAX,
        _KILL_MODE_INVALID = -1
} KillMode;

enum UnitType {
        UNIT_SERVICE = 0,
        UNIT_SOCKET,
        UNIT_TARGET,
        UNIT_DEVICE,
        UNIT_MOUNT,
        UNIT_AUTOMOUNT,
        UNIT_SNAPSHOT,
        UNIT_TIMER,
        UNIT_SWAP,
        _UNIT_TYPE_MAX,
        _UNIT_TYPE_INVALID = -1
};

enum UnitLoadState {
        UNIT_STUB,
        UNIT_LOADED,
        UNIT_FAILED,
        UNIT_MERGED,
        _UNIT_LOAD_STATE_MAX,
        _UNIT_LOAD_STATE_INVALID = -1
};

enum UnitActiveState {
        UNIT_ACTIVE,
        UNIT_ACTIVE_RELOADING,
        UNIT_INACTIVE,
        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_ACTIVE_RELOADING;
}

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

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

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

        /* Inverse of the above */
        UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
        UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'soft_requires' and 'soft_requisite' is 'soft_required_by' */
        UNIT_WANTED_BY,               /* inverse of 'wants' */

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

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

        /* 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"
#include "cgroup.h"

struct Meta {
        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 *description;
        char *fragment_path; /* if loaded from a config file this is the primary path to it */

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

        usec_t active_enter_timestamp;
        usec_t active_exit_timestamp;

        /* Counterparts in the cgroup filesystem */
        CGroupBonding *cgroup_bondings;

        /* Per type list */
        LIST_FIELDS(Meta, units_per_type);

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

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

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

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

        /* Used during GC sweeps */
        unsigned gc_marker;

        /* If we go down, pull down everything that depends on us, too */
        bool recursive_stop;

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

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

        bool sent_dbus_new_signal:1;
};

#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"

union Unit {
        Meta meta;
        Service service;
        Timer timer;
        Socket socket;
        Target target;
        Device device;
        Mount mount;
        Automount automount;
        Snapshot snapshot;
        Swap swap;
};

struct UnitVTable {
        const char *suffix;

        /* 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 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);

        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);

        /* 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 finegrained 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);

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

        /* Called whenever a name thus 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, DBusMessage *message);

        /* 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);

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

        /* If true units of this types can never have "Requires"
         * dependencies, because state changes can only be observed,
         * not triggered */
        bool no_requires:1;

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

        /* Exclude this type from snapshots */
        bool no_snapshots:1;

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

        /* Exclude from isolation requests */
        bool no_isolate:1;
};

extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];

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

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

/* For casting the various unit types into a unit */
#define UNIT(u) ((Unit*) (u))

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);

Unit *unit_new(Manager *m);
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_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *filename, 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_exec_dependencies(Unit *u, ExecContext *c);

int unit_add_cgroup(Unit *u, CGroupBonding *b);
int unit_add_cgroup_from_text(Unit *u, const char *name);
int unit_add_default_cgroup(Unit *u);
CGroupBonding* unit_get_default_cgroup(Unit *u);

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);

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

const char *unit_description(Unit *u);

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);
bool unit_can_start(Unit *u);

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

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

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, usec_t delay, 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);

char *unit_name_printf(Unit *u, const char* text);
char *unit_full_printf(Unit *u, const char *text);
char **unit_full_printf_strv(Unit *u, char **l);

bool unit_can_serialize(Unit *u);
int unit_serialize(Unit *u, FILE *f, FDSet *fds);
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);

const char *unit_type_to_string(UnitType i);
UnitType unit_type_from_string(const char *s);

const char *unit_load_state_to_string(UnitLoadState i);
UnitLoadState unit_load_state_from_string(const char *s);

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

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

const char *kill_mode_to_string(KillMode k);
KillMode kill_mode_from_string(const char *s);

#endif