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 enum UnitType {
  47         UNIT_SERVICE = 0,
  48         UNIT_TIMER,
  49         UNIT_SOCKET,
  50         UNIT_TARGET,
  51         UNIT_DEVICE,
  52         UNIT_MOUNT,
  53         UNIT_AUTOMOUNT,
  54         UNIT_SNAPSHOT,
  55         _UNIT_TYPE_MAX,
  56         _UNIT_TYPE_INVALID = -1,
  57 };
  58
  59 enum UnitLoadState {
  60         UNIT_STUB,
  61         UNIT_LOADED,
  62         UNIT_FAILED,
  63         UNIT_MERGED,
  64         _UNIT_LOAD_STATE_MAX,
  65         _UNIT_LOAD_STATE_INVALID = -1
  66 };
  67
  68 enum UnitActiveState {
  69         UNIT_ACTIVE,
  70         UNIT_ACTIVE_RELOADING,
  71         UNIT_INACTIVE,
  72         UNIT_ACTIVATING,
  73         UNIT_DEACTIVATING,
  74         _UNIT_ACTIVE_STATE_MAX,
  75         _UNIT_ACTIVE_STATE_INVALID = -1
  76 };
  77
  78 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
  79         return t == UNIT_ACTIVE || t == UNIT_ACTIVE_RELOADING;
  80 }
  81
  82 static inline bool UNIT_IS_ACTIVE_OR_ACTIVATING(UnitActiveState t) {
  83         return t == UNIT_ACTIVE || t == UNIT_ACTIVATING || t == UNIT_ACTIVE_RELOADING;
  84 }
  85
  86 static inline bool UNIT_IS_INACTIVE_OR_DEACTIVATING(UnitActiveState t) {
  87         return t == UNIT_INACTIVE || t == UNIT_DEACTIVATING;
  88 }
  89
  90 enum UnitDependency {
  91         /* Positive dependencies */
  92         UNIT_REQUIRES,
  93         UNIT_SOFT_REQUIRES,
  94         UNIT_WANTS,
  95         UNIT_REQUISITE,
  96         UNIT_SOFT_REQUISITE,
  97
  98         /* Inverse of the above */
  99         UNIT_REQUIRED_BY,       /* inverse of 'requires' and 'requisite' is 'required_by' */
 100         UNIT_SOFT_REQUIRED_BY,  /* inverse of 'soft_requires' and 'soft_requisite' is 'soft_required_by' */
 101         UNIT_WANTED_BY,         /* inverse of 'wants' */
 102
 103         /* Negative dependencies */
 104         UNIT_CONFLICTS,         /* inverse of 'conflicts' is 'conflicts' */
 105
 106         /* Order */
 107         UNIT_BEFORE,            /* inverse of before is after and vice versa */
 108         UNIT_AFTER,
 109
 110         _UNIT_DEPENDENCY_MAX,
 111         _UNIT_DEPENDENCY_INVALID = -1
 112 };
 113
 114 #include "manager.h"
 115 #include "job.h"
 116 #include "cgroup.h"
 117
 118 struct Meta {
 119         Manager *manager;
 120
 121         UnitType type;
 122         UnitLoadState load_state;
 123         Unit *merged_into;
 124
 125         char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
 126
 127         Set *names;
 128         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 129
 130         char *description;
 131         char *fragment_path; /* if loaded from a config file this is the primary path to it */
 132
 133         /* If there is something to do with this unit, then this is
 134          * the job for it */
 135         Job *job;
 136
 137         bool in_load_queue:1;
 138         bool in_dbus_queue:1;
 139         bool in_cleanup_queue:1;
 140         bool sent_dbus_new_signal:1;
 141
 142         /* If we go down, pull down everything that depends on us, too */
 143         bool recursive_stop;
 144
 145         /* Garbage collect us we nobody wants or requires us anymore */
 146         bool stop_when_unneeded;
 147
 148         usec_t active_enter_timestamp;
 149         usec_t active_exit_timestamp;
 150
 151         /* Counterparts in the cgroup filesystem */
 152         CGroupBonding *cgroup_bondings;
 153
 154         /* Load queue */
 155         LIST_FIELDS(Meta, load_queue);
 156
 157         /* Per type list */
 158         LIST_FIELDS(Meta, units_per_type);
 159
 160         /* D-Bus queue */
 161         LIST_FIELDS(Meta, dbus_queue);
 162
 163         /* Cleanup queue */
 164         LIST_FIELDS(Meta, cleanup_queue);
 165 };
 166
 167 #include "service.h"
 168 #include "timer.h"
 169 #include "socket.h"
 170 #include "target.h"
 171 #include "device.h"
 172 #include "mount.h"
 173 #include "automount.h"
 174 #include "snapshot.h"
 175
 176 union Unit {
 177         Meta meta;
 178         Service service;
 179         Timer timer;
 180         Socket socket;
 181         Target target;
 182         Device device;
 183         Mount mount;
 184         Automount automount;
 185         Snapshot snapshot;
 186 };
 187
 188 struct UnitVTable {
 189         const char *suffix;
 190
 191         int (*init)(Unit *u, UnitLoadState *new_state);
 192         void (*done)(Unit *u);
 193         int (*coldplug)(Unit *u);
 194
 195         void (*dump)(Unit *u, FILE *f, const char *prefix);
 196
 197         int (*start)(Unit *u);
 198         int (*stop)(Unit *u);
 199         int (*reload)(Unit *u);
 200
 201         bool (*can_reload)(Unit *u);
 202
 203         /* Boils down the more complex internal state of this unit to
 204          * a simpler one that the engine can understand */
 205         UnitActiveState (*active_state)(Unit *u);
 206
 207         void (*fd_event)(Unit *u, int fd, uint32_t events, Watch *w);
 208         void (*sigchld_event)(Unit *u, pid_t pid, int code, int status);
 209         void (*timer_event)(Unit *u, uint64_t n_elapsed, Watch *w);
 210
 211         void (*cgroup_notify_empty)(Unit *u);
 212
 213         /* This is called for each unit type and should be used to
 214          * enumerate existing devices and load them. However,
 215          * everything that is loaded here should still stay in
 216          * inactive state. It is the job of the coldplug() call above
 217          * to put the units into the initial state.  */
 218         int (*enumerate)(Manager *m);
 219
 220         /* Type specific cleanups. */
 221         void (*shutdown)(Manager *m);
 222 };
 223
 224 extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
 225
 226 #define UNIT_VTABLE(u) unit_vtable[(u)->meta.type]
 227
 228 /* For casting a unit into the various unit types */
 229 #define DEFINE_CAST(UPPERCASE, MixedCase)                               \
 230         static inline MixedCase* UPPERCASE(Unit *u) {                   \
 231                 if (!u || u->meta.type != UNIT_##UPPERCASE)             \
 232                         return NULL;                                    \
 233                                                                         \
 234                 return (MixedCase*) u;                                  \
 235         }
 236
 237 /* For casting the various unit types into a unit */
 238 #define UNIT(u) ((Unit*) (u))
 239
 240 DEFINE_CAST(SOCKET, Socket);
 241 DEFINE_CAST(TIMER, Timer);
 242 DEFINE_CAST(SERVICE, Service);
 243 DEFINE_CAST(TARGET, Target);
 244 DEFINE_CAST(DEVICE, Device);
 245 DEFINE_CAST(MOUNT, Mount);
 246 DEFINE_CAST(AUTOMOUNT, Automount);
 247 DEFINE_CAST(SNAPSHOT, Snapshot);
 248
 249 UnitType unit_name_to_type(const char *n);
 250 bool unit_name_is_valid(const char *n);
 251 char *unit_name_change_suffix(const char *n, const char *suffix);
 252
 253 Unit *unit_new(Manager *m);
 254 void unit_free(Unit *u);
 255
 256 int unit_add_name(Unit *u, const char *name);
 257 int unit_add_dependency(Unit *u, UnitDependency d, Unit *other);
 258 int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name);
 259 int unit_add_dependency_by_name_inverse(Unit *u, UnitDependency d, const char *name);
 260
 261 int unit_add_exec_dependencies(Unit *u, ExecContext *c);
 262
 263 int unit_add_cgroup(Unit *u, CGroupBonding *b);
 264 int unit_add_cgroup_from_text(Unit *u, const char *name);
 265 int unit_add_default_cgroup(Unit *u);
 266 CGroupBonding* unit_get_default_cgroup(Unit *u);
 267
 268 int unit_choose_id(Unit *u, const char *name);
 269 int unit_set_description(Unit *u, const char *description);
 270
 271 void unit_add_to_load_queue(Unit *u);
 272 void unit_add_to_dbus_queue(Unit *u);
 273 void unit_add_to_cleanup_queue(Unit *u);
 274
 275 int unit_merge(Unit *u, Unit *other);
 276 int unit_merge_by_name(Unit *u, const char *other);
 277
 278 Unit *unit_follow_merge(Unit *u);
 279
 280 int unit_load_fragment_and_dropin(Unit *u, UnitLoadState *new_state);
 281 int unit_load_fragment_and_dropin_optional(Unit *u, UnitLoadState *new_state);
 282 int unit_load(Unit *unit);
 283
 284 const char* unit_id(Unit *u);
 285 const char *unit_description(Unit *u);
 286
 287 bool unit_has_name(Unit *u, const char *name);
 288
 289 UnitActiveState unit_active_state(Unit *u);
 290
 291 void unit_dump(Unit *u, FILE *f, const char *prefix);
 292
 293 bool unit_can_reload(Unit *u);
 294 bool unit_can_start(Unit *u);
 295
 296 int unit_start(Unit *u);
 297 int unit_stop(Unit *u);
 298 int unit_reload(Unit *u);
 299
 300 void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns);
 301
 302 int unit_watch_fd(Unit *u, int fd, uint32_t events, Watch *w);
 303 void unit_unwatch_fd(Unit *u, Watch *w);
 304
 305 int unit_watch_pid(Unit *u, pid_t pid);
 306 void unit_unwatch_pid(Unit *u, pid_t pid);
 307
 308 int unit_watch_timer(Unit *u, usec_t delay, Watch *w);
 309 void unit_unwatch_timer(Unit *u, Watch *w);
 310
 311 bool unit_job_is_applicable(Unit *u, JobType j);
 312
 313 int set_unit_path(const char *p);
 314
 315 char *unit_name_escape_path(const char *path, const char *suffix);
 316
 317 const char *unit_type_to_string(UnitType i);
 318 UnitType unit_type_from_string(const char *s);
 319
 320 const char *unit_load_state_to_string(UnitLoadState i);
 321 UnitLoadState unit_load_state_from_string(const char *s);
 322
 323 const char *unit_active_state_to_string(UnitActiveState i);
 324 UnitActiveState unit_active_state_from_string(const char *s);
 325
 326 const char *unit_dependency_to_string(UnitDependency i);
 327 UnitDependency unit_dependency_from_string(const char *s);
 328
 329 char *unit_dbus_path(Unit *u);
 330
 331 #endif