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
  45 enum UnitType {
  46         UNIT_SERVICE = 0,
  47         UNIT_SOCKET,
  48         UNIT_TARGET,
  49         UNIT_DEVICE,
  50         UNIT_MOUNT,
  51         UNIT_AUTOMOUNT,
  52         UNIT_SNAPSHOT,
  53         UNIT_TIMER,
  54         UNIT_SWAP,
  55         UNIT_PATH,
  56         _UNIT_TYPE_MAX,
  57         _UNIT_TYPE_INVALID = -1
  58 };
  59
  60 enum UnitLoadState {
  61         UNIT_STUB,
  62         UNIT_LOADED,
  63         UNIT_ERROR,
  64         UNIT_MERGED,
  65         UNIT_MASKED,
  66         _UNIT_LOAD_STATE_MAX,
  67         _UNIT_LOAD_STATE_INVALID = -1
  68 };
  69
  70 enum UnitActiveState {
  71         UNIT_ACTIVE,
  72         UNIT_RELOADING,
  73         UNIT_INACTIVE,
  74         UNIT_FAILED,
  75         UNIT_ACTIVATING,
  76         UNIT_DEACTIVATING,
  77         _UNIT_ACTIVE_STATE_MAX,
  78         _UNIT_ACTIVE_STATE_INVALID = -1
  79 };
  80
  81 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  82         return t == UNIT_ACTIVE || t == UNIT_RELOADING;
  83 }
  84
  85 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  86         return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_RELOADING;
  87 }
  88
  89 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  90         return t == UNIT_INACTIVE || t == UNIT_FAILED || t == UNIT_DEACTIVATING;
  91 }
  92
  93 static inline bool UNIT_IS_INACTIVE_OR_FAILED(UnitActiveState t) {
  94         return t == UNIT_INACTIVE || t == UNIT_FAILED;
  95 }
  96
  97 enum UnitDependency {
  98         /* Positive dependencies */
  99         UNIT_REQUIRES,
 100         UNIT_REQUIRES_OVERRIDABLE,
 101         UNIT_REQUISITE,
 102         UNIT_REQUISITE_OVERRIDABLE,
 103         UNIT_WANTS,
 104         UNIT_BIND_TO,
 105
 106         /* Inverse of the above */
 107         UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
 108         UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'requires_overridable' and 'requisite_overridable' is 'soft_required_by' */
 109         UNIT_WANTED_BY,               /* inverse of 'wants' */
 110         UNIT_BOUND_BY,                /* inverse of 'bind_to' */
 111
 112         /* Negative dependencies */
 113         UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */
 114         UNIT_CONFLICTED_BY,
 115
 116         /* Order */
 117         UNIT_BEFORE,                  /* inverse of 'before' is 'after' and vice versa */
 118         UNIT_AFTER,
 119
 120         /* On Failure */
 121         UNIT_ON_FAILURE,
 122
 123         /* Triggers (i.e. a socket triggers a service) */
 124         UNIT_TRIGGERS,
 125         UNIT_TRIGGERED_BY,
 126
 127         /* Propagate reloads */
 128         UNIT_PROPAGATE_RELOAD_TO,
 129         UNIT_PROPAGATE_RELOAD_FROM,
 130
 131         /* Reference information for GC logic */
 132         UNIT_REFERENCES,              /* Inverse of 'references' is 'referenced_by' */
 133         UNIT_REFERENCED_BY,
 134
 135         _UNIT_DEPENDENCY_MAX,
 136         _UNIT_DEPENDENCY_INVALID = -1
 137 };
 138
 139 #include "manager.h"
 140 #include "job.h"
 141 #include "cgroup.h"
 142 #include "cgroup-attr.h"
 143
 144 struct Unit {
 145         Manager *manager;
 146
 147         UnitType type;
 148         UnitLoadState load_state;
 149         Unit *merged_into;
 150
 151         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 152         char *instance;
 153
 154         Set *names;
 155         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 156
 157         char **requires_mounts_for;
 158
 159         char *description;
 160
 161         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 162         usec_t fragment_mtime;
 163
 164         /* If there is something to do with this unit, then this is the installed job for it */
 165         Job *job;
 166
 167         /* JOB_NOP jobs are special and can be installed without disturbing the real job. */
 168         Job *nop_job;
 169
 170         usec_t job_timeout;
 171
 172         /* References to this */
 173         LIST_HEAD(UnitRef, refs);
 174
 175         /* Conditions to check */
 176         LIST_HEAD(Condition, conditions);
 177
 178         dual_timestamp condition_timestamp;
 179
 180         dual_timestamp inactive_exit_timestamp;
 181         dual_timestamp active_enter_timestamp;
 182         dual_timestamp active_exit_timestamp;
 183         dual_timestamp inactive_enter_timestamp;
 184
 185         /* Counterparts in the cgroup filesystem */
 186         CGroupBonding *cgroup_bondings;
 187         CGroupAttribute *cgroup_attributes;
 188
 189         /* Per type list */
 190         LIST_FIELDS(Unit, units_by_type);
 191
 192         /* All units which have requires_mounts_for set */
 193         LIST_FIELDS(Unit, has_requires_mounts_for);
 194
 195         /* Load queue */
 196         LIST_FIELDS(Unit, load_queue);
 197
 198         /* D-Bus queue */
 199         LIST_FIELDS(Unit, dbus_queue);
 200
 201         /* Cleanup queue */
 202         LIST_FIELDS(Unit, cleanup_queue);
 203
 204         /* GC queue */
 205         LIST_FIELDS(Unit, gc_queue);
 206
 207         /* Used during GC sweeps */
 208         unsigned gc_marker;
 209
 210         /* When deserializing, temporarily store the job type for this
 211          * unit here, if there was a job scheduled.
 212          * Only for deserializing from a legacy version. New style uses full
 213          * serialized jobs. */
 214         int deserialized_job; /* This is actually of type JobType */
 215
 216         /* Error code when we didn't manage to load the unit (negative) */
 217         int load_error;
 218
 219         /* Cached unit file state */
 220         UnitFileState unit_file_state;
 221
 222         /* Garbage collect us we nobody wants or requires us anymore */
 223         bool stop_when_unneeded;
 224
 225         /* Create default dependencies */
 226         bool default_dependencies;
 227
 228         /* Refuse manual starting, allow starting only indirectly via dependency. */
 229         bool refuse_manual_start;
 230
 231         /* Don't allow the user to stop this unit manually, allow stopping only indirectly via dependency. */
 232         bool refuse_manual_stop;
 233
 234         /* Allow isolation requests */
 235         bool allow_isolate;
 236
 237         /* Isolate OnFailure unit */
 238         bool on_failure_isolate;
 239
 240         /* Ignore this unit when isolating */
 241         bool ignore_on_isolate;
 242
 243         /* Ignore this unit when snapshotting */
 244         bool ignore_on_snapshot;
 245
 246         /* Did the last condition check suceed? */
 247         bool condition_result;
 248
 249         bool in_load_queue:1;
 250         bool in_dbus_queue:1;
 251         bool in_cleanup_queue:1;
 252         bool in_gc_queue:1;
 253
 254         bool sent_dbus_new_signal:1;
 255
 256         bool no_gc:1;
 257
 258         bool in_audit:1;
 259 };
 260
 261 struct UnitRef {
 262         /* Keeps tracks of references to a unit. This is useful so
 263          * that we can merge two units if necessary and correct all
 264          * references to them */
 265
 266         Unit* unit;
 267         LIST_FIELDS(UnitRef, refs);
 268 };
 269
 270 struct UnitStatusMessageFormats {
 271         const char *starting_stopping[2];
 272         const char *finished_start_job[_JOB_RESULT_MAX];
 273         const char *finished_stop_job[_JOB_RESULT_MAX];
 274 };
 275
 276 #include "service.h"
 277 #include "timer.h"
 278 #include "socket.h"
 279 #include "target.h"
 280 #include "device.h"
 281 #include "mount.h"
 282 #include "automount.h"
 283 #include "snapshot.h"
 284 #include "swap.h"
 285 #include "path.h"
 286
 287 struct UnitVTable {
 288         const char *suffix;
 289
 290         /* How much memory does an object of this unit type need */
 291         size_t object_size;
 292
 293         /* Config file sections this unit type understands, separated
 294          * by NUL chars */
 295         const char *sections;
 296
 297         /* This should reset all type-specific variables. This should
 298          * not allocate memory, and is called with zero-initialized
 299          * data. It should hence only initialize variables that need
 300          * to be set != 0. */
 301         void (*init)(Unit *u);
 302
 303         /* This should free all type-specific variables. It should be
 304          * idempotent. */
 305         void (*done)(Unit *u);
 306
 307         /* Actually load data from disk. This may fail, and should set
 308          * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
 309          * UNIT_STUB if no configuration could be found. */
 310         int (*load)(Unit *u);
 311
 312         /* If a a lot of units got created via enumerate(), this is
 313          * where to actually set the state and call unit_notify(). */
 314         int (*coldplug)(Unit *u);
 315
 316         void (*dump)(Unit *u, FILE *f, const char *prefix);
 317
 318         int (*start)(Unit *u);
 319         int (*stop)(Unit *u);
 320         int (*reload)(Unit *u);
 321
 322         int (*kill)(Unit *u, KillWho w, KillMode m, int signo, DBusError *error);
 323
 324         bool (*can_reload)(Unit *u);
 325
 326         /* Write all data that cannot be restored from other sources
 327          * away using unit_serialize_item() */
 328         int (*serialize)(Unit *u, FILE *f, FDSet *fds);
 329
 330         /* Restore one item from the serialization */
 331         int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);
 332
 333         /* Boils down the more complex internal state of this unit to
 334          * a simpler one that the engine can understand */
 335         UnitActiveState (*active_state)(Unit *u);
 336
 337         /* Returns the substate specific to this unit type as
 338          * string. This is purely information so that we can give the
 339          * user a more fine grained explanation in which actual state a
 340          * unit is in. */
 341         const char* (*sub_state_to_string)(Unit *u);
 342
 343         /* Return true when there is reason to keep this entry around
 344          * even nothing references it and it isn't active in any
 345          * way */
 346         bool (*check_gc)(Unit *u);
 347
 348         /* Return true when this unit is suitable for snapshotting */
 349         bool (*check_snapshot)(Unit *u);
 350
 351         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 352         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 353         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 354
 355         /* Check whether unit needs a daemon reload */
 356         bool (*need_daemon_reload)(Unit *u);
 357
 358         /* Reset failed state if we are in failed state */
 359         void (*reset_failed)(Unit *u);
 360
 361         /* Called whenever any of the cgroups this unit watches for
 362          * ran empty */
 363         void (*cgroup_notify_empty)(Unit *u);
 364
 365         /* Called whenever a process of this unit sends us a message */
 366         void (*notify_message)(Unit *u, pid_t pid, char **tags);
 367
 368         /* Called whenever a name thus Unit registered for comes or
 369          * goes away. */
 370         void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, const char *new_owner);
 371
 372         /* Called whenever a bus PID lookup finishes */
 373         void (*bus_query_pid_done)(Unit *u, const char *name, pid_t pid);
 374
 375         /* Called for each message received on the bus */
 376         DBusHandlerResult (*bus_message_handler)(Unit *u, DBusConnection *c, DBusMessage *message);
 377
 378         /* Return the unit this unit is following */
 379         Unit *(*following)(Unit *u);
 380
 381         /* Return the set of units that are following each other */
 382         int (*following_set)(Unit *u, Set **s);
 383
 384         /* This is called for each unit type and should be used to
 385          * enumerate existing devices and load them. However,
 386          * everything that is loaded here should still stay in
 387          * inactive state. It is the job of the coldplug() call above
 388          * to put the units into the initial state.  */
 389         int (*enumerate)(Manager *m);
 390
 391         /* Type specific cleanups. */
 392         void (*shutdown)(Manager *m);
 393
 394         /* When sending out PropertiesChanged signal, which properties
 395          * shall be invalidated? This is a NUL separated list of
 396          * strings, to minimize relocations a little. */
 397         const char *bus_invalidating_properties;
 398
 399         /* The interface name */
 400         const char *bus_interface;
 401
 402         UnitStatusMessageFormats status_message_formats;
 403
 404         /* Can units of this type have multiple names? */
 405         bool no_alias:1;
 406
 407         /* Instances make no sense for this type */
 408         bool no_instances:1;
 409
 410         /* Exclude from automatic gc */
 411         bool no_gc:1;
 412 };
 413
 414 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 415
 416 #define UNIT_VTABLE(u) unit_vtable[(u)->type]
 417
 418 /* For casting a unit into the various unit types */
 419 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 420         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 421                 if (_unlikely_(!u || u->type != UNIT_##UPPERCASE))      \
 422                         return NULL;                                    \
 423                                                                         \
 424                 return (MixedCase*) u;                                  \
 425         }
 426
 427 /* For casting the various unit types into a unit */
 428 #define UNIT(u) (&(u)->meta)
 429
 430 DEFINE_CAST(SOCKET, Socket);
 431 DEFINE_CAST(TIMER, Timer);
 432 DEFINE_CAST(SERVICE, Service);
 433 DEFINE_CAST(TARGET, Target);
 434 DEFINE_CAST(DEVICE, Device);
 435 DEFINE_CAST(MOUNT, Mount);
 436 DEFINE_CAST(AUTOMOUNT, Automount);
 437 DEFINE_CAST(SNAPSHOT, Snapshot);
 438 DEFINE_CAST(SWAP, Swap);
 439 DEFINE_CAST(PATH, Path);
 440
 441 Unit *unit_new(Manager *m, size_t size);
 442 void unit_free(Unit *u);
 443
 444 int unit_add_name(Unit *u, const char *name);
 445
 446 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference);
 447 int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference);
 448
 449 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
 450 int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);
 451
 452 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name, const char *filename, bool add_reference);
 453 int unit_add_two_dependencies_by_name_inverse(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference);
 454
 455 int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 456
 457 int unit_add_cgroup(Unit *u, CGroupBonding *b);
 458 int unit_add_cgroup_from_text(Unit *u, const char *name);
 459 int unit_add_default_cgroups(Unit *u);
 460 CGroupBonding* unit_get_default_cgroup(Unit *u);
 461 int unit_add_cgroup_attribute(Unit *u, const char *controller, const char *name, const char *value, CGroupAttributeMapCallback map_callback);
 462
 463 int unit_choose_id(Unit *u, const char *name);
 464 int unit_set_description(Unit *u, const char *description);
 465
 466 bool unit_check_gc(Unit *u);
 467
 468 void unit_add_to_load_queue(Unit *u);
 469 void unit_add_to_dbus_queue(Unit *u);
 470 void unit_add_to_cleanup_queue(Unit *u);
 471 void unit_add_to_gc_queue(Unit *u);
 472
 473 int unit_merge(Unit *u, Unit *other);
 474 int unit_merge_by_name(Unit *u, const char *other);
 475
 476 Unit *unit_follow_merge(Unit *u);
 477
 478 int unit_load_fragment_and_dropin(Unit *u);
 479 int unit_load_fragment_and_dropin_optional(Unit *u);
 480 int unit_load(Unit *unit);
 481
 482 const char *unit_description(Unit *u);
 483
 484 bool unit_has_name(Unit *u, const char *name);
 485
 486 UnitActiveState unit_active_state(Unit *u);
 487
 488 const char* unit_sub_state_to_string(Unit *u);
 489
 490 void unit_dump(Unit *u, FILE *f, const char *prefix);
 491
 492 bool unit_can_reload(Unit *u);
 493 bool unit_can_start(Unit *u);
 494 bool unit_can_isolate(Unit *u);
 495
 496 int unit_start(Unit *u);
 497 int unit_stop(Unit *u);
 498 int unit_reload(Unit *u);
 499
 500 int unit_kill(Unit *u, KillWho w, KillMode m, int signo, DBusError *error);
 501
 502 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_success);
 503
 504 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 505 void unit_unwatch_fd(Unit *u, Watch *w);
 506
 507 int unit_watch_pid(Unit *u, pid_t pid);
 508 void unit_unwatch_pid(Unit *u, pid_t pid);
 509
 510 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 511 void unit_unwatch_timer(Unit *u, Watch *w);
 512
 513 int unit_watch_bus_name(Unit *u, const char *name);
 514 void unit_unwatch_bus_name(Unit *u, const char *name);
 515
 516 bool unit_job_is_applicable(Unit *u, JobType j);
 517
 518 int set_unit_path(const char *p);
 519
 520 char *unit_dbus_path(Unit *u);
 521
 522 int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
 523 int unit_get_related_unit(Unit *u, const char *type, Unit **_found);
 524
 525 char *unit_name_printf(Unit *u, const char* text);
 526 char *unit_full_printf(Unit *u, const char *text);
 527 char **unit_full_printf_strv(Unit *u, char **l);
 528
 529 bool unit_can_serialize(Unit *u);
 530 int unit_serialize(Unit *u, FILE *f, FDSet *fds);
 531 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *value, ...) _printf_attr_(4,5);
 532 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value);
 533 int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
 534
 535 int unit_add_node_link(Unit *u, const char *what, bool wants);
 536
 537 int unit_coldplug(Unit *u);
 538
 539 void unit_status_printf(Unit *u, const char *status, const char *format, ...);
 540
 541 bool unit_need_daemon_reload(Unit *u);
 542
 543 void unit_reset_failed(Unit *u);
 544
 545 Unit *unit_following(Unit *u);
 546
 547 bool unit_pending_inactive(Unit *u);
 548 bool unit_pending_active(Unit *u);
 549
 550 int unit_add_default_target_dependency(Unit *u, Unit *target);
 551
 552 int unit_following_set(Unit *u, Set **s);
 553
 554 UnitType unit_name_to_type(const char *n);
 555 bool unit_name_is_valid(const char *n, bool template_ok);
 556
 557 void unit_trigger_on_failure(Unit *u);
 558
 559 bool unit_condition_test(Unit *u);
 560
 561 UnitFileState unit_get_unit_file_state(Unit *u);
 562
 563 Unit* unit_ref_set(UnitRef *ref, Unit *u);
 564 void unit_ref_unset(UnitRef *ref);
 565
 566 #define UNIT_DEREF(ref) ((ref).unit)
 567
 568 int unit_add_one_mount_link(Unit *u, Mount *m);
 569 int unit_add_mount_links(Unit *u);
 570
 571 const char *unit_load_state_to_string(UnitLoadState i);
 572 UnitLoadState unit_load_state_from_string(const char *s);
 573
 574 const char *unit_active_state_to_string(UnitActiveState i);
 575 UnitActiveState unit_active_state_from_string(const char *s);
 576
 577 const char *unit_dependency_to_string(UnitDependency i);
 578 UnitDependency unit_dependency_from_string(const char *s);
 579
 580 #endif