src/core/target.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "dbus-target.h"
  23 #include "log.h"
  24 #include "special.h"
  25 #include "string-util.h"
  26 #include "unit-name.h"
  27 #include "unit.h"
  28 #include "target.h"
  29
  30 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  31         [TARGET_DEAD] = UNIT_INACTIVE,
  32         [TARGET_ACTIVE] = UNIT_ACTIVE
  33 };
  34
  35 static void target_set_state(Target *t, TargetState state) {
  36         TargetState old_state;
  37         assert(t);
  38
  39         old_state = t->state;
  40         t->state = state;
  41
  42         if (state != old_state)
  43                 log_debug("%s changed %s -> %s",
  44                           UNIT(t)->id,
  45                           target_state_to_string(old_state),
  46                           target_state_to_string(state));
  47
  48         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  49 }
  50
  51 static int target_add_default_dependencies(Target *t) {
  52
  53         static const UnitDependency deps[] = {
  54                 UNIT_REQUIRES,
  55                 UNIT_REQUIRES_OVERRIDABLE,
  56                 UNIT_REQUISITE,
  57                 UNIT_REQUISITE_OVERRIDABLE,
  58                 UNIT_WANTS,
  59                 UNIT_BINDS_TO,
  60                 UNIT_PART_OF
  61         };
  62
  63         Iterator i;
  64         Unit *other;
  65         int r;
  66         unsigned k;
  67
  68         assert(t);
  69
  70         /* Imply ordering for requirement dependencies on target
  71          * units. Note that when the user created a contradicting
  72          * ordering manually we won't add anything in here to make
  73          * sure we don't create a loop. */
  74
  75         for (k = 0; k < ELEMENTSOF(deps); k++)
  76                 SET_FOREACH(other, UNIT(t)->dependencies[deps[k]], i) {
  77                         r = unit_add_default_target_dependency(other, UNIT(t));
  78                         if (r < 0)
  79                                 return r;
  80                 }
  81
  82         /* Make sure targets are unloaded on shutdown */
  83         return unit_add_dependency_by_name(UNIT(t), UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  84 }
  85
  86 static int target_load(Unit *u) {
  87         Target *t = TARGET(u);
  88         int r;
  89
  90         assert(t);
  91
  92         r = unit_load_fragment_and_dropin(u);
  93         if (r < 0)
  94                 return r;
  95
  96         /* This is a new unit? Then let's add in some extras */
  97         if (u->load_state == UNIT_LOADED && u->default_dependencies) {
  98                 r = target_add_default_dependencies(t);
  99                 if (r < 0)
 100                         return r;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int target_coldplug(Unit *u) {
 107         Target *t = TARGET(u);
 108
 109         assert(t);
 110         assert(t->state == TARGET_DEAD);
 111
 112         if (t->deserialized_state != t->state)
 113                 target_set_state(t, t->deserialized_state);
 114
 115         return 0;
 116 }
 117
 118 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 119         Target *t = TARGET(u);
 120
 121         assert(t);
 122         assert(f);
 123
 124         fprintf(f,
 125                 "%sTarget State: %s\n",
 126                 prefix, target_state_to_string(t->state));
 127 }
 128
 129 static int target_start(Unit *u) {
 130         Target *t = TARGET(u);
 131
 132         assert(t);
 133         assert(t->state == TARGET_DEAD);
 134
 135         target_set_state(t, TARGET_ACTIVE);
 136         return 1;
 137 }
 138
 139 static int target_stop(Unit *u) {
 140         Target *t = TARGET(u);
 141
 142         assert(t);
 143         assert(t->state == TARGET_ACTIVE);
 144
 145         target_set_state(t, TARGET_DEAD);
 146         return 1;
 147 }
 148
 149 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 150         Target *s = TARGET(u);
 151
 152         assert(s);
 153         assert(f);
 154         assert(fds);
 155
 156         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 157         return 0;
 158 }
 159
 160 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 161         Target *s = TARGET(u);
 162
 163         assert(u);
 164         assert(key);
 165         assert(value);
 166         assert(fds);
 167
 168         if (streq(key, "state")) {
 169                 TargetState state;
 170
 171                 state = target_state_from_string(value);
 172                 if (state < 0)
 173                         log_debug("Failed to parse state value %s", value);
 174                 else
 175                         s->deserialized_state = state;
 176
 177         } else
 178                 log_debug("Unknown serialization key '%s'", key);
 179
 180         return 0;
 181 }
 182
 183 _pure_ static UnitActiveState target_active_state(Unit *u) {
 184         assert(u);
 185
 186         return state_translation_table[TARGET(u)->state];
 187 }
 188
 189 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 190         assert(u);
 191
 192         return target_state_to_string(TARGET(u)->state);
 193 }
 194
 195 const UnitVTable target_vtable = {
 196         .object_size = sizeof(Target),
 197
 198         .sections =
 199                 "Unit\0"
 200                 "Target\0"
 201                 "Install\0",
 202
 203         .load = target_load,
 204         .coldplug = target_coldplug,
 205
 206         .dump = target_dump,
 207
 208         .start = target_start,
 209         .stop = target_stop,
 210
 211         .serialize = target_serialize,
 212         .deserialize_item = target_deserialize_item,
 213
 214         .active_state = target_active_state,
 215         .sub_state_to_string = target_sub_state_to_string,
 216
 217         .bus_vtable = bus_target_vtable,
 218
 219         .status_message_formats = {
 220                 .finished_start_job = {
 221                         [JOB_DONE]       = "Reached target %s.",
 222                 },
 223                 .finished_stop_job = {
 224                         [JOB_DONE]       = "Stopped target %s.",
 225                 },
 226         },
 227 };