unit.h

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   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 128
  43 #define DEFAULT_TIMEOUT_USEC (20*USEC_PER_SEC)
  44 #define DEFAULT_RESTART_USEC (100*USEC_PER_MSEC)
  45
  46 typedef enum KillMode {
  47         KILL_CONTROL_GROUP = 0,
  48         KILL_PROCESS_GROUP,
  49         KILL_PROCESS,
  50         KILL_NONE,
  51         _KILL_MODE_MAX,
  52         _KILL_MODE_INVALID = -1
  53 } KillMode;
  54
  55 enum UnitType {
  56         UNIT_SERVICE = 0,
  57         UNIT_TIMER,
  58         UNIT_SOCKET,
  59         UNIT_TARGET,
  60         UNIT_DEVICE,
  61         UNIT_MOUNT,
  62         UNIT_AUTOMOUNT,
  63         UNIT_SNAPSHOT,
  64         _UNIT_TYPE_MAX,
  65         _UNIT_TYPE_INVALID = -1
  66 };
  67
  68 enum UnitLoadState {
  69         UNIT_STUB,
  70         UNIT_LOADED,
  71         UNIT_FAILED,
  72         UNIT_MERGED,
  73         _UNIT_LOAD_STATE_MAX,
  74         _UNIT_LOAD_STATE_INVALID = -1
  75 };
  76
  77 enum UnitActiveState {
  78         UNIT_ACTIVE,
  79         UNIT_ACTIVE_RELOADING,
  80         UNIT_INACTIVE,
  81         UNIT_ACTIVATING,
  82         UNIT_DEACTIVATING,
  83         _UNIT_ACTIVE_STATE_MAX,
  84         _UNIT_ACTIVE_STATE_INVALID = -1
  85 };
  86
  87 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  88         return t == UNIT_ACTIVE || t == UNIT_ACTIVE_RELOADING;
  89 }
  90
  91 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  92         return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_ACTIVE_RELOADING;
  93 }
  94
  95 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  96         return t == UNIT_INACTIVE || t == UNIT_DEACTIVATING;
  97 }
  98
  99 enum UnitDependency {
 100         /* Positive dependencies */
 101         UNIT_REQUIRES,
 102         UNIT_SOFT_REQUIRES,
 103         UNIT_WANTS,
 104         UNIT_REQUISITE,
 105         UNIT_SOFT_REQUISITE,
 106
 107         /* Inverse of the above */
 108         UNIT_REQUIRED_BY,       /* inverse of 'requires' and 'requisite' is 'required_by' */
 109         UNIT_SOFT_REQUIRED_BY,  /* inverse of 'soft_requires' and 'soft_requisite' is 'soft_required_by' */
 110         UNIT_WANTED_BY,         /* inverse of 'wants' */
 111
 112         /* Negative dependencies */
 113         UNIT_CONFLICTS,         /* inverse of 'conflicts' is 'conflicts' */
 114
 115         /* Order */
 116         UNIT_BEFORE,            /* inverse of before is after and vice versa */
 117         UNIT_AFTER,
 118
 119         _UNIT_DEPENDENCY_MAX,
 120         _UNIT_DEPENDENCY_INVALID = -1
 121 };
 122
 123 #include "manager.h"
 124 #include "job.h"
 125 #include "cgroup.h"
 126
 127 struct Meta {
 128         Manager *manager;
 129
 130         UnitType type;
 131         UnitLoadState load_state;
 132         Unit *merged_into;
 133
 134         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 135
 136         Set *names;
 137         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 138
 139         char *description;
 140         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 141
 142         /* If there is something to do with this unit, then this is
 143          * the job for it */
 144         Job *job;
 145
 146         bool in_load_queue:1;
 147         bool in_dbus_queue:1;
 148         bool in_cleanup_queue:1;
 149         bool sent_dbus_new_signal:1;
 150
 151         /* If we go down, pull down everything that depends on us, too */
 152         bool recursive_stop;
 153
 154         /* Garbage collect us we nobody wants or requires us anymore */
 155         bool stop_when_unneeded;
 156
 157         usec_t active_enter_timestamp;
 158         usec_t active_exit_timestamp;
 159
 160         /* Counterparts in the cgroup filesystem */
 161         CGroupBonding *cgroup_bondings;
 162
 163         /* Load queue */
 164         LIST_FIELDS(Meta, load_queue);
 165
 166         /* Per type list */
 167         LIST_FIELDS(Meta, units_per_type);
 168
 169         /* D-Bus queue */
 170         LIST_FIELDS(Meta, dbus_queue);
 171
 172         /* Cleanup queue */
 173         LIST_FIELDS(Meta, cleanup_queue);
 174 };
 175
 176 #include "service.h"
 177 #include "timer.h"
 178 #include "socket.h"
 179 #include "target.h"
 180 #include "device.h"
 181 #include "mount.h"
 182 #include "automount.h"
 183 #include "snapshot.h"
 184
 185 union Unit {
 186         Meta meta;
 187         Service service;
 188         Timer timer;
 189         Socket socket;
 190         Target target;
 191         Device device;
 192         Mount mount;
 193         Automount automount;
 194         Snapshot snapshot;
 195 };
 196
 197 struct UnitVTable {
 198         const char *suffix;
 199
 200         /* Can units of this type have multiple names? */
 201         bool no_alias:1;
 202
 203         /* If true units of this types can never have "Requires"
 204          * dependencies, because state changes can only be observed,
 205          * not triggered */
 206         bool refuse_requires:1;
 207
 208         /* This should reset all type-specific variables. This should
 209          * not allocate memory, and is either called with 0
 210          * initialized data, or with data left from done() */
 211         void (*init)(Unit *u);
 212
 213         /* Actually load data from disk. This may fail, and should set
 214          * load_state to UNIT_LOADED, UNIT_MERGED or leave it at
 215          * UNIT_STUB if no configuration could be found. */
 216         int (*load)(Unit *u);
 217
 218         /* This should free all type-specific variables. It should be
 219          * idempotent. There's no need to reset variables that deal
 220          * with dynamic memory/resources. */
 221         void (*done)(Unit *u);
 222
 223         /* If a a lot of units got created via enumerate(), this is
 224          * where to actually set the state and call unit_notify(). */
 225         int (*coldplug)(Unit *u);
 226
 227         void (*dump)(Unit *u, FILE *f, const char *prefix);
 228
 229         int (*start)(Unit *u);
 230         int (*stop)(Unit *u);
 231         int (*reload)(Unit *u);
 232
 233         bool (*can_reload)(Unit *u);
 234
 235         /* Boils down the more complex internal state of this unit to
 236          * a simpler one that the engine can understand */
 237         UnitActiveState (*active_state)(Unit *u);
 238
 239         /* Returns the substate specific to this unit type as
 240          * string. This is purely information so that we can give the
 241          * user a more finegrained explanation in which actual state a
 242          * unit is in. */
 243         const char* (*sub_state_to_string)(Unit *u);
 244
 245         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 246         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 247         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 248
 249         void (*cgroup_notify_empty)(Unit *u);
 250
 251         /* This is called for each unit type and should be used to
 252          * enumerate existing devices and load them. However,
 253          * everything that is loaded here should still stay in
 254          * inactive state. It is the job of the coldplug() call above
 255          * to put the units into the initial state.  */
 256         int (*enumerate)(Manager *m);
 257
 258         /* Type specific cleanups. */
 259         void (*shutdown)(Manager *m);
 260 };
 261
 262 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 263
 264 #define UNIT_VTABLE(u) unit_vtable[(u)->meta.type]
 265
 266 /* For casting a unit into the various unit types */
 267 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 268         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 269                 if (!u || u->meta.type != UNIT_##UPPERCASE)             \
 270                         return NULL;                                    \
 271                                                                         \
 272                 return (MixedCase*) u;                                  \
 273         }
 274
 275 /* For casting the various unit types into a unit */
 276 #define UNIT(u) ((Unit*) (u))
 277
 278 DEFINE_CAST(SOCKET, Socket);
 279 DEFINE_CAST(TIMER, Timer);
 280 DEFINE_CAST(SERVICE, Service);
 281 DEFINE_CAST(TARGET, Target);
 282 DEFINE_CAST(DEVICE, Device);
 283 DEFINE_CAST(MOUNT, Mount);
 284 DEFINE_CAST(AUTOMOUNT, Automount);
 285 DEFINE_CAST(SNAPSHOT, Snapshot);
 286
 287 UnitType unit_name_to_type(const char *n);
 288 bool unit_name_is_valid(const char *n);
 289 char *unit_name_change_suffix(const char *n, const char *suffix);
 290
 291 Unit *unit_new(Manager *m);
 292 void unit_free(Unit *u);
 293
 294 int unit_add_name(Unit *u, const char *name);
 295 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other);
 296 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name);
 297 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name);
 298
 299 int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 300
 301 int unit_add_cgroup(Unit *u, CGroupBonding *b);
 302 int unit_add_cgroup_from_text(Unit *u, const char *name);
 303 int unit_add_default_cgroup(Unit *u);
 304 CGroupBonding* unit_get_default_cgroup(Unit *u);
 305
 306 int unit_choose_id(Unit *u, const char *name);
 307 int unit_set_description(Unit *u, const char *description);
 308
 309 void unit_add_to_load_queue(Unit *u);
 310 void unit_add_to_dbus_queue(Unit *u);
 311 void unit_add_to_cleanup_queue(Unit *u);
 312
 313 int unit_merge(Unit *u, Unit *other);
 314 int unit_merge_by_name(Unit *u, const char *other);
 315
 316 Unit *unit_follow_merge(Unit *u);
 317
 318 int unit_load_fragment_and_dropin(Unit *u);
 319 int unit_load_fragment_and_dropin_optional(Unit *u);
 320 int unit_load(Unit *unit);
 321
 322 const char* unit_id(Unit *u);
 323 const char *unit_description(Unit *u);
 324
 325 bool unit_has_name(Unit *u, const char *name);
 326
 327 UnitActiveState unit_active_state(Unit *u);
 328
 329 const char* unit_sub_state_to_string(Unit *u);
 330
 331 void unit_dump(Unit *u, FILE *f, const char *prefix);
 332
 333 bool unit_can_reload(Unit *u);
 334 bool unit_can_start(Unit *u);
 335
 336 int unit_start(Unit *u);
 337 int unit_stop(Unit *u);
 338 int unit_reload(Unit *u);
 339
 340 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns);
 341
 342 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 343 void unit_unwatch_fd(Unit *u, Watch *w);
 344
 345 int unit_watch_pid(Unit *u, pid_t pid);
 346 void unit_unwatch_pid(Unit *u, pid_t pid);
 347
 348 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 349 void unit_unwatch_timer(Unit *u, Watch *w);
 350
 351 bool unit_job_is_applicable(Unit *u, JobType j);
 352
 353 int set_unit_path(const char *p);
 354
 355 char *unit_name_escape_path(const char *path, const char *suffix);
 356
 357 char *unit_dbus_path(Unit *u);
 358
 359 int unit_load_related_unit(Unit *u, const char *type, Unit **_found);
 360
 361 const char *unit_type_to_string(UnitType i);
 362 UnitType unit_type_from_string(const char *s);
 363
 364 const char *unit_load_state_to_string(UnitLoadState i);
 365 UnitLoadState unit_load_state_from_string(const char *s);
 366
 367 const char *unit_active_state_to_string(UnitActiveState i);
 368 UnitActiveState unit_active_state_from_string(const char *s);
 369
 370 const char *unit_dependency_to_string(UnitDependency i);
 371 UnitDependency unit_dependency_from_string(const char *s);
 372
 373 const char *kill_mode_to_string(KillMode k);
 374 KillMode kill_mode_from_string(const char *s);
 375
 376 #endif