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