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