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
  42 #define UNIT_NAME_MAX 256
  43 #define DEFAULT_TIMEOUT_USEC (60*USEC_PER_SEC)
  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_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
 105         /* Inverse of the above */
 106         UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
 107         UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'soft_requires' and 'soft_requisite' is 'soft_required_by' */
 108         UNIT_WANTED_BY,               /* inverse of 'wants' */
 109
 110         /* Negative dependencies */
 111         UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */
 112         UNIT_CONFLICTED_BY,
 113
 114         /* Order */
 115         UNIT_BEFORE,                  /* inverse of 'before' is 'after' and vice versa */
 116         UNIT_AFTER,
 117
 118         /* On Failure */
 119         UNIT_ON_FAILURE,
 120
 121         /* Reference information for GC logic */
 122         UNIT_REFERENCES,              /* Inverse of 'references' is 'referenced_by' */
 123         UNIT_REFERENCED_BY,
 124
 125         _UNIT_DEPENDENCY_MAX,
 126         _UNIT_DEPENDENCY_INVALID = -1
 127 };
 128
 129 #include "manager.h"
 130 #include "job.h"
 131 #include "cgroup.h"
 132
 133 struct Meta {
 134         Manager *manager;
 135
 136         UnitType type;
 137         UnitLoadState load_state;
 138         Unit *merged_into;
 139
 140         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 141         char *instance;
 142
 143         Set *names;
 144         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 145
 146         char *description;
 147
 148         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 149         usec_t fragment_mtime;
 150
 151         /* If there is something to do with this unit, then this is
 152          * the job for it */
 153         Job *job;
 154
 155         usec_t job_timeout;
 156
 157         dual_timestamp inactive_exit_timestamp;
 158         dual_timestamp active_enter_timestamp;
 159         dual_timestamp active_exit_timestamp;
 160         dual_timestamp inactive_enter_timestamp;
 161
 162         /* Counterparts in the cgroup filesystem */
 163         CGroupBonding *cgroup_bondings;
 164
 165         /* Per type list */
 166         LIST_FIELDS(Meta, units_per_type);
 167
 168         /* Load queue */
 169         LIST_FIELDS(Meta, load_queue);
 170
 171         /* D-Bus queue */
 172         LIST_FIELDS(Meta, dbus_queue);
 173
 174         /* Cleanup queue */
 175         LIST_FIELDS(Meta, cleanup_queue);
 176
 177         /* GC queue */
 178         LIST_FIELDS(Meta, gc_queue);
 179
 180         /* Used during GC sweeps */
 181         unsigned gc_marker;
 182
 183         /* When deserializing, temporarily store the job type for this
 184          * unit here, if there was a job scheduled */
 185         int deserialized_job; /* This is actually of type JobType */
 186
 187         /* Error code when we didn't manage to load the unit (negative) */
 188         int load_error;
 189
 190         /* If we go down, pull down everything that depends on us, too */
 191         bool recursive_stop;
 192
 193         /* Garbage collect us we nobody wants or requires us anymore */
 194         bool stop_when_unneeded;
 195
 196         /* Create default depedencies */
 197         bool default_dependencies;
 198
 199         /* Bring up this unit even if a dependency fails to start */
 200         bool ignore_dependency_failure;
 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         bool (*can_reload)(Unit *u);
 277
 278         /* Write all data that cannot be restored from other sources
 279          * away using unit_serialize_item() */
 280         int (*serialize)(Unit *u, FILE *f, FDSet *fds);
 281
 282         /* Restore one item from the serialization */
 283         int (*deserialize_item)(Unit *u, const char *key, const char *data, FDSet *fds);
 284
 285         /* Boils down the more complex internal state of this unit to
 286          * a simpler one that the engine can understand */
 287         UnitActiveState (*active_state)(Unit *u);
 288
 289         /* Returns the substate specific to this unit type as
 290          * string. This is purely information so that we can give the
 291          * user a more finegrained explanation in which actual state a
 292          * unit is in. */
 293         const char* (*sub_state_to_string)(Unit *u);
 294
 295         /* Return true when there is reason to keep this entry around
 296          * even nothing references it and it isn't active in any
 297          * way */
 298         bool (*check_gc)(Unit *u);
 299
 300         /* Return true when this unit is suitable for snapshotting */
 301         bool (*check_snapshot)(Unit *u);
 302
 303         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 304         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 305         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 306
 307         /* Reset failed state if we are in failed state */
 308         void (*reset_failed)(Unit *u);
 309
 310         /* Called whenever any of the cgroups this unit watches for
 311          * ran empty */
 312         void (*cgroup_notify_empty)(Unit *u);
 313
 314         /* Called whenever a process of this unit sends us a message */
 315         void (*notify_message)(Unit *u, pid_t pid, char **tags);
 316
 317         /* Called whenever a name thus Unit registered for comes or
 318          * goes away. */
 319         void (*bus_name_owner_change)(Unit *u, const char *name, const char *old_owner, const char *new_owner);
 320
 321         /* Called whenever a bus PID lookup finishes */
 322         void (*bus_query_pid_done)(Unit *u, const char *name, pid_t pid);
 323
 324         /* Called for each message received on the bus */
 325         DBusHandlerResult (*bus_message_handler)(Unit *u, DBusConnection *c, DBusMessage *message);
 326
 327         /* Return the unit this unit is following */
 328         Unit *(*following)(Unit *u);
 329
 330         /* This is called for each unit type and should be used to
 331          * enumerate existing devices and load them. However,
 332          * everything that is loaded here should still stay in
 333          * inactive state. It is the job of the coldplug() call above
 334          * to put the units into the initial state.  */
 335         int (*enumerate)(Manager *m);
 336
 337         /* Type specific cleanups. */
 338         void (*shutdown)(Manager *m);
 339
 340         /* When sending out PropertiesChanged signal, which properties
 341          * shall be invalidated? This is a NUL seperated list of
 342          * strings, to minimize relocations a little. */
 343         const char *bus_invalidating_properties;
 344
 345         /* The interface name */
 346         const char *bus_interface;
 347
 348         /* Can units of this type have multiple names? */
 349         bool no_alias:1;
 350
 351         /* If true units of this types can never have "Requires"
 352          * dependencies, because state changes can only be observed,
 353          * not triggered */
 354         bool no_requires: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_cgroup(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 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns);
 458
 459 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 460 void unit_unwatch_fd(Unit *u, Watch *w);
 461
 462 int unit_watch_pid(Unit *u, pid_t pid);
 463 void unit_unwatch_pid(Unit *u, pid_t pid);
 464
 465 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 466 void unit_unwatch_timer(Unit *u, Watch *w);
 467
 468 int unit_watch_bus_name(Unit *u, const char *name);
 469 void unit_unwatch_bus_name(Unit *u, const char *name);
 470
 471 bool unit_job_is_applicable(Unit *u, JobType j);
 472
 473 int set_unit_path(const char *p);
 474
 475 char *unit_dbus_path(Unit *u);
 476
 477 int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
 478 int unit_get_related_unit(Unit *u, const char *type, Unit **_found);
 479
 480 char *unit_name_printf(Unit *u, const char* text);
 481 char *unit_full_printf(Unit *u, const char *text);
 482 char **unit_full_printf_strv(Unit *u, char **l);
 483
 484 bool unit_can_serialize(Unit *u);
 485 int unit_serialize(Unit *u, FILE *f, FDSet *fds);
 486 void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *value, ...) _printf_attr_(4,5);
 487 void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value);
 488 int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
 489
 490 int unit_add_node_link(Unit *u, const char *what, bool wants);
 491
 492 int unit_coldplug(Unit *u);
 493
 494 void unit_status_printf(Unit *u, const char *format, ...);
 495
 496 bool unit_need_daemon_reload(Unit *u);
 497
 498 void unit_reset_failed(Unit *u);
 499
 500 Unit *unit_following(Unit *u);
 501
 502 const char *unit_load_state_to_string(UnitLoadState i);
 503 UnitLoadState unit_load_state_from_string(const char *s);
 504
 505 const char *unit_active_state_to_string(UnitActiveState i);
 506 UnitActiveState unit_active_state_from_string(const char *s);
 507
 508 const char *unit_dependency_to_string(UnitDependency i);
 509 UnitDependency unit_dependency_from_string(const char *s);
 510
 511 const char *kill_mode_to_string(KillMode k);
 512 KillMode kill_mode_from_string(const char *s);
 513
 514 #endif