src/core/unit.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #ifndef foounithfoo
   4 #define foounithfoo
   5
   6 /***
   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
  11   systemd is free software; you can redistribute it and/or modify it
  12   under the terms of the GNU Lesser General Public License as published by
  13   the Free Software Foundation; either version 2.1 of the License, or
  14   (at your option) any later version.
  15
  16   systemd is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   Lesser General Public License for more details.
  20
  21   You should have received a copy of the GNU Lesser General Public License
  22   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  23 ***/
  24
  25 #include <stdbool.h>
  26 #include <stdlib.h>
  27
  28 typedef struct Unit Unit;
  29 typedef struct UnitVTable UnitVTable;
  30 typedef enum UnitType UnitType;
  31 typedef enum UnitLoadState UnitLoadState;
  32 typedef enum UnitActiveState UnitActiveState;
  33 typedef enum UnitDependency UnitDependency;
  34 typedef struct UnitRef UnitRef;
  35 typedef struct UnitStatusMessageFormats UnitStatusMessageFormats;
  36
  37 #include "set.h"
  38 #include "util.h"
  39 #include "list.h"
  40 #include "socket-util.h"
  41 #include "execute.h"
  42 #include "condition.h"
  43 #include "install.h"
  44 #include "unit-name.h"
  45
  46 enum UnitLoadState {
  47         UNIT_STUB,
  48         UNIT_LOADED,
  49         UNIT_ERROR,
  50         UNIT_MERGED,
  51         UNIT_MASKED,
  52         _UNIT_LOAD_STATE_MAX,
  53         _UNIT_LOAD_STATE_INVALID = -1
  54 };
  55
  56 enum UnitActiveState {
  57         UNIT_ACTIVE,
  58         UNIT_RELOADING,
  59         UNIT_INACTIVE,
  60         UNIT_FAILED,
  61         UNIT_ACTIVATING,
  62         UNIT_DEACTIVATING,
  63         _UNIT_ACTIVE_STATE_MAX,
  64         _UNIT_ACTIVE_STATE_INVALID = -1
  65 };
  66
  67 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  68         return t == UNIT_ACTIVE || t == UNIT_RELOADING;
  69 }
  70
  71 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  72         return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_RELOADING;
  73 }
  74
  75 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  76         return t == UNIT_INACTIVE || t == UNIT_FAILED || t == UNIT_DEACTIVATING;
  77 }
  78
  79 static inline bool UNIT_IS_INACTIVE_OR_FAILED(UnitActiveState t) {
  80         return t == UNIT_INACTIVE || t == UNIT_FAILED;
  81 }
  82
  83 enum UnitDependency {
  84         /* Positive dependencies */
  85         UNIT_REQUIRES,
  86         UNIT_REQUIRES_OVERRIDABLE,
  87         UNIT_REQUISITE,
  88         UNIT_REQUISITE_OVERRIDABLE,
  89         UNIT_WANTS,
  90         UNIT_BIND_TO,
  91
  92         /* Inverse of the above */
  93         UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
  94         UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'requires_overridable' and 'requisite_overridable' is 'soft_required_by' */
  95         UNIT_WANTED_BY,               /* inverse of 'wants' */
  96         UNIT_BOUND_BY,                /* inverse of 'bind_to' */
  97
  98         /* Negative dependencies */
  99         UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */
 100         UNIT_CONFLICTED_BY,
 101
 102         /* Order */
 103         UNIT_BEFORE,                  /* inverse of 'before' is 'after' and vice versa */
 104         UNIT_AFTER,
 105
 106         /* On Failure */
 107         UNIT_ON_FAILURE,
 108
 109         /* Triggers (i.e. a socket triggers a service) */
 110         UNIT_TRIGGERS,
 111         UNIT_TRIGGERED_BY,
 112
 113         /* Propagate reloads */
 114         UNIT_PROPAGATE_RELOAD_TO,
 115         UNIT_PROPAGATE_RELOAD_FROM,
 116
 117         /* Reference information for GC logic */
 118         UNIT_REFERENCES,              /* Inverse of 'references' is 'referenced_by' */
 119         UNIT_REFERENCED_BY,
 120
 121         _UNIT_DEPENDENCY_MAX,
 122         _UNIT_DEPENDENCY_INVALID = -1
 123 };
 124
 125 #include "manager.h"
 126 #include "job.h"
 127 #include "cgroup.h"
 128 #include "cgroup-attr.h"
 129
 130 struct Unit {
 131         Manager *manager;
 132
 133         UnitType type;
 134         UnitLoadState load_state;
 135         Unit *merged_into;
 136
 137         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 138         char *instance;
 139
 140         Set *names;
 141         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 142
 143         char **requires_mounts_for;
 144
 145         char *description;
 146         char **documentation;
 147
 148         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 149         char *source_path; /* if converted, the source file */
 150         usec_t fragment_mtime;
 151         usec_t source_mtime;
 152
 153         /* If there is something to do with this unit, then this is the installed job for it */
 154         Job *job;
 155
 156         /* JOB_NOP jobs are special and can be installed without disturbing the real job. */
 157         Job *nop_job;
 158
 159         usec_t job_timeout;
 160
 161         /* References to this */
 162         LIST_HEAD(UnitRef, refs);
 163
 164         /* Conditions to check */
 165         LIST_HEAD(Condition, conditions);
 166
 167         dual_timestamp condition_timestamp;
 168
 169         dual_timestamp inactive_exit_timestamp;
 170         dual_timestamp active_enter_timestamp;
 171         dual_timestamp active_exit_timestamp;
 172         dual_timestamp inactive_enter_timestamp;
 173
 174         /* Counterparts in the cgroup filesystem */
 175         CGroupBonding *cgroup_bondings;
 176         CGroupAttribute *cgroup_attributes;
 177
 178         /* Per type list */
 179         LIST_FIELDS(Unit, units_by_type);
 180
 181         /* All units which have requires_mounts_for set */
 182         LIST_FIELDS(Unit, has_requires_mounts_for);
 183
 184         /* Load queue */
 185         LIST_FIELDS(Unit, load_queue);
 186
 187         /* D-Bus queue */
 188         LIST_FIELDS(Unit, dbus_queue);
 189
 190         /* Cleanup queue */
 191         LIST_FIELDS(Unit, cleanup_queue);
 192
 193         /* GC queue */
 194         LIST_FIELDS(Unit, gc_queue);
 195
 196         /* Used during GC sweeps */
 197         unsigned gc_marker;
 198
 199         /* When deserializing, temporarily store the job type for this
 200          * unit here, if there was a job scheduled.
 201          * Only for deserializing from a legacy version. New style uses full
 202          * serialized jobs. */
 203         int deserialized_job; /* This is actually of type JobType */
 204
 205         /* Error code when we didn't manage to load the unit (negative) */
 206         int load_error;
 207
 208         /* Cached unit file state */
 209         UnitFileState unit_file_state;
 210
 211         /* Garbage collect us we nobody wants or requires us anymore */
 212         bool stop_when_unneeded;
 213
 214         /* Create default dependencies */
 215         bool default_dependencies;
 216
 217         /* Refuse manual starting, allow starting only indirectly via dependency. */
 218         bool refuse_manual_start;
 219
 220         /* Don't allow the user to stop this unit manually, allow stopping only indirectly via dependency. */
 221         bool refuse_manual_stop;
 222
 223         /* Allow isolation requests */
 224         bool allow_isolate;
 225
 226         /* Isolate OnFailure unit */
 227         bool on_failure_isolate;
 228
 229         /* Ignore this unit when isolating */
 230         bool ignore_on_isolate;
 231
 232         /* Ignore this unit when snapshotting */
 233         bool ignore_on_snapshot;
 234
 235         /* Did the last condition check suceed? */
 236         bool condition_result;
 237
 238         bool in_load_queue:1;
 239         bool in_dbus_queue:1;
 240         bool in_cleanup_queue:1;
 241         bool in_gc_queue:1;
 242
 243         bool sent_dbus_new_signal:1;
 244
 245         bool no_gc:1;
 246
 247         bool in_audit:1;
 248 };
 249
 250 struct UnitRef {
 251         /* Keeps tracks of references to a unit. This is useful so
 252          * that we can merge two units if necessary and correct all
 253          * references to them */
 254
 255         Unit* unit;
 256         LIST_FIELDS(UnitRef, refs);
 257 };
 258
 259 struct UnitStatusMessageFormats {
 260         const char *starting_stopping[2];
 261         const char *finished_start_job[_JOB_RESULT_MAX];
 262         const char *finished_stop_job[_JOB_RESULT_MAX];
 263 };
 264
 265 #include "service.h"
 266 #include "timer.h"
 267 #include "socket.h"
 268 #include "target.h"
 269 #include "device.h"
 270 #include "mount.h"
 271 #include "automount.h"
 272 #include "snapshot.h"
 273 #include "swap.h"
 274 #include "path.h"
 275
 276 struct UnitVTable {
 277         const char *suffix;
 278
 279         /* How much memory does an object of this unit type need */
 280         size_t object_size;
 281
 282         /* Config file sections this unit type understands, separated
 283          * by NUL chars */
 284         const char *sections;
 285
 286         /* This should reset all type-specific variables. This should
 287          * not allocate memory, and is called with zero-initialized
 288          * data. It should hence only initialize variables that need
 289          * to be set != 0. */
 290         void (*init)(Unit *u);
 291
 292         /* This should free all type-specific variables. It should be
 293          * idempotent. */
 294         void (*done)(Unit *u);
 295
 296         /* Actually load data from disk. This may fail, and should set
 297          * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
 298          * UNIT_STUB if no configuration could be found. */
 299         int (*load)(Unit *u);
 300
 301         /* If a a lot of units got created via enumerate(), this is
 302          * where to actually set the state and call unit_notify(). */
 303         int (*coldplug)(Unit *u);
 304
 305         void (*dump)(Unit *u, FILE *f, const char *prefix);
 306
 307         int (*start)(Unit *u);
 308         int (*stop)(Unit *u);
 309         int (*reload)(Unit *u);
 310
 311         int (*kill)(Unit *u, KillWho w, KillMode m, int signo, DBusError *error);
 312
 313         bool (*can_reload)(Unit *u);
 314
 315         /* Write all data that cannot be restored from other sources
 316          * away using unit_serialize_item() */
 317         int (*serialize)(Unit *u, FILE *f, FDSet *fds);
 318
 319         /* Restore one item from the serialization */
 320         int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);
 321
 322         /* Boils down the more complex internal state of this unit to
 323          * a simpler one that the engine can understand */
 324         UnitActiveState (*active_state)(Unit *u);
 325
 326         /* Returns the substate specific to this unit type as
 327          * string. This is purely information so that we can give the
 328          * user a more fine grained explanation in which actual state a
 329          * unit is in. */
 330         const char* (*sub_state_to_string)(Unit *u);
 331
 332         /* Return true when there is reason to keep this entry around
 333          * even nothing references it and it isn't active in any
 334          * way */
 335         bool (*check_gc)(Unit *u);
 336
 337         /* Return true when this unit is suitable for snapshotting */
 338         bool (*check_snapshot)(Unit *u);
 339
 340         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 341         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 342         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 343
 344         /* Reset failed state if we are in failed state */
 345         void (*reset_failed)(Unit *u);
 346
 347         /* Called whenever any of the cgroups this unit watches for
 348          * ran empty */
 349         void (*cgroup_notify_empty)(Unit *u);
 350
 351         /* Called whenever a process of this unit sends us a message */
 352         void (*notify_message)(Unit *u, pid_t pid, char **tags);
 353
 354         /* Called whenever a name thus Unit registered for comes or
 355          * goes away. */
 356         void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, const char *new_owner);
 357
 358         /* Called whenever a bus PID lookup finishes */
 359         void (*bus_query_pid_done)(Unit *u, const char *name, pid_t pid);
 360
 361         /* Called for each message received on the bus */
 362         DBusHandlerResult (*bus_message_handler)(Unit *u, DBusConnection *c, DBusMessage *message);
 363
 364         /* Return the unit this unit is following */
 365         Unit *(*following)(Unit *u);
 366
 367         /* Return the set of units that are following each other */
 368         int (*following_set)(Unit *u, Set **s);
 369
 370         /* This is called for each unit type and should be used to
 371          * enumerate existing devices and load them. However,
 372          * everything that is loaded here should still stay in
 373          * inactive state. It is the job of the coldplug() call above
 374          * to put the units into the initial state.  */
 375         int (*enumerate)(Manager *m);
 376
 377         /* Type specific cleanups. */
 378         void (*shutdown)(Manager *m);
 379
 380         /* When sending out PropertiesChanged signal, which properties
 381          * shall be invalidated? This is a NUL separated list of
 382          * strings, to minimize relocations a little. */
 383         const char *bus_invalidating_properties;
 384
 385         /* The interface name */
 386         const char *bus_interface;
 387
 388         UnitStatusMessageFormats status_message_formats;
 389
 390         /* Can units of this type have multiple names? */
 391         bool no_alias:1;
 392
 393         /* Instances make no sense for this type */
 394         bool no_instances:1;
 395
 396         /* Exclude from automatic gc */
 397         bool no_gc:1;
 398 };
 399
 400 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 401
 402 #define UNIT_VTABLE(u) unit_vtable[(u)->type]
 403
 404 /* For casting a unit into the various unit types */
 405 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 406         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 407                 if (_unlikely_(!u || u->type != UNIT_##UPPERCASE))      \
 408                         return NULL;                                    \
 409                                                                         \
 410                 return (MixedCase*) u;                                  \
 411         }
 412
 413 /* For casting the various unit types into a unit */
 414 #define UNIT(u) (&(u)->meta)
 415
 416 DEFINE_CAST(SOCKET, Socket);
 417 DEFINE_CAST(TIMER, Timer);
 418 DEFINE_CAST(SERVICE, Service);
 419 DEFINE_CAST(TARGET, Target);
 420 DEFINE_CAST(DEVICE, Device);
 421 DEFINE_CAST(MOUNT, Mount);
 422 DEFINE_CAST(AUTOMOUNT, Automount);
 423 DEFINE_CAST(SNAPSHOT, Snapshot);
 424 DEFINE_CAST(SWAP, Swap);
 425 DEFINE_CAST(PATH, Path);
 426
 427 Unit *unit_new(Manager *m, size_t size);
 428 void unit_free(Unit *u);
 429
 430 int unit_add_name(Unit *u, const char *name);
 431
 432 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference);
 433 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference);
 434
 435 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
 436 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);
 437
 438 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
 439 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);
 440
 441 int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 442
 443 int unit_add_cgroup(Unit *u, CGroupBonding *b);
 444 int unit_add_cgroup_from_text(Unit *u, const char *name);
 445 int unit_add_default_cgroups(Unit *u);
 446 CGroupBonding* unit_get_default_cgroup(Unit *u);
 447 int unit_add_cgroup_attribute(Unit *u, const char *controller, const char *name, const char *value, CGroupAttributeMapCallback map_callback);
 448
 449 int unit_choose_id(Unit *u, const char *name);
 450 int unit_set_description(Unit *u, const char *description);
 451
 452 bool unit_check_gc(Unit *u);
 453
 454 void unit_add_to_load_queue(Unit *u);
 455 void unit_add_to_dbus_queue(Unit *u);
 456 void unit_add_to_cleanup_queue(Unit *u);
 457 void unit_add_to_gc_queue(Unit *u);
 458
 459 int unit_merge(Unit *u, Unit *other);
 460 int unit_merge_by_name(Unit *u, const char *other);
 461
 462 Unit *unit_follow_merge(Unit *u);
 463
 464 int unit_load_fragment_and_dropin(Unit *u);
 465 int unit_load_fragment_and_dropin_optional(Unit *u);
 466 int unit_load(Unit *unit);
 467
 468 const char *unit_description(Unit *u);
 469
 470 bool unit_has_name(Unit *u, const char *name);
 471
 472 UnitActiveState unit_active_state(Unit *u);
 473
 474 const char* unit_sub_state_to_string(Unit *u);
 475
 476 void unit_dump(Unit *u, FILE *f, const char *prefix);
 477
 478 bool unit_can_reload(Unit *u);
 479 bool unit_can_start(Unit *u);
 480 bool unit_can_isolate(Unit *u);
 481
 482 int unit_start(Unit *u);
 483 int unit_stop(Unit *u);
 484 int unit_reload(Unit *u);
 485
 486 int unit_kill(Unit *u, KillWho w, KillMode m, int signo, DBusError *error);
 487
 488 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_success);
 489
 490 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 491 void unit_unwatch_fd(Unit *u, Watch *w);
 492
 493 int unit_watch_pid(Unit *u, pid_t pid);
 494 void unit_unwatch_pid(Unit *u, pid_t pid);
 495
 496 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 497 void unit_unwatch_timer(Unit *u, Watch *w);
 498
 499 int unit_watch_bus_name(Unit *u, const char *name);
 500 void unit_unwatch_bus_name(Unit *u, const char *name);
 501
 502 bool unit_job_is_applicable(Unit *u, JobType j);
 503
 504 int set_unit_path(const char *p);
 505
 506 char *unit_dbus_path(Unit *u);
 507
 508 int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
 509 int unit_get_related_unit(Unit *u, const char *type, Unit **_found);
 510
 511 char *unit_name_printf(Unit *u, const char* text);
 512 char *unit_full_printf(Unit *u, const char *text);
 513 char **unit_full_printf_strv(Unit *u, char **l);
 514
 515 bool unit_can_serialize(Unit *u);
 516 int unit_serialize(Unit *u, FILE *f, FDSet *fds);
 517 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *value, ...) _printf_attr_(4,5);
 518 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value);
 519 int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
 520
 521 int unit_add_node_link(Unit *u, const char *what, bool wants);
 522
 523 int unit_coldplug(Unit *u);
 524
 525 void unit_status_printf(Unit *u, const char *status, const char *format, ...);
 526
 527 bool unit_need_daemon_reload(Unit *u);
 528
 529 void unit_reset_failed(Unit *u);
 530
 531 Unit *unit_following(Unit *u);
 532
 533 bool unit_pending_inactive(Unit *u);
 534 bool unit_pending_active(Unit *u);
 535
 536 int unit_add_default_target_dependency(Unit *u, Unit *target);
 537
 538 int unit_following_set(Unit *u, Set **s);
 539
 540 UnitType unit_name_to_type(const char *n);
 541 bool unit_name_is_valid(const char *n, bool template_ok);
 542
 543 void unit_trigger_on_failure(Unit *u);
 544
 545 bool unit_condition_test(Unit *u);
 546
 547 UnitFileState unit_get_unit_file_state(Unit *u);
 548
 549 Unit* unit_ref_set(UnitRef *ref, Unit *u);
 550 void unit_ref_unset(UnitRef *ref);
 551
 552 #define UNIT_DEREF(ref) ((ref).unit)
 553
 554 int unit_add_one_mount_link(Unit *u, Mount *m);
 555 int unit_add_mount_links(Unit *u);
 556
 557 const char *unit_load_state_to_string(UnitLoadState i);
 558 UnitLoadState unit_load_state_from_string(const char *s);
 559
 560 const char *unit_active_state_to_string(UnitActiveState i);
 561 UnitActiveState unit_active_state_from_string(const char *s);
 562
 563 const char *unit_dependency_to_string(UnitDependency i);
 564 UnitDependency unit_dependency_from_string(const char *s);
 565
 566 #endif