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