src/core/unit.h

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