src/core/target.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include "dbus-target.h"
  21 #include "log.h"
  22 #include "special.h"
  23 #include "string-util.h"
  24 #include "unit-name.h"
  25 #include "unit.h"
  26 #include "target.h"
  27
  28 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  29         [TARGET_DEAD] = UNIT_INACTIVE,
  30         [TARGET_ACTIVE] = UNIT_ACTIVE
  31 };
  32
  33 static void target_set_state(Target *t, TargetState state) {
  34         TargetState old_state;
  35         assert(t);
  36
  37         old_state = t->state;
  38         t->state = state;
  39
  40         if (state != old_state)
  41                 log_debug("%s changed %s -> %s",
  42                           UNIT(t)->id,
  43                           target_state_to_string(old_state),
  44                           target_state_to_string(state));
  45
  46         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  47 }
  48
  49 static int target_add_default_dependencies(Target *t) {
  50
  51         static const UnitDependency deps[] = {
  52                 UNIT_REQUIRES,
  53                 UNIT_REQUISITE,
  54                 UNIT_WANTS,
  55                 UNIT_BINDS_TO,
  56                 UNIT_PART_OF
  57         };
  58
  59         Iterator i;
  60         Unit *other;
  61         int r;
  62         unsigned k;
  63
  64         assert(t);
  65
  66         if (!UNIT(t)->default_dependencies)
  67                 return 0;
  68
  69         /* Imply ordering for requirement dependencies on target
  70          * units. Note that when the user created a contradicting
  71          * ordering manually we won't add anything in here to make
  72          * sure we don't create a loop. */
  73
  74         for (k = 0; k < ELEMENTSOF(deps); k++)
  75                 SET_FOREACH(other, UNIT(t)->dependencies[deps[k]], i) {
  76                         r = unit_add_default_target_dependency(other, UNIT(t));
  77                         if (r < 0)
  78                                 return r;
  79                 }
  80
  81         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  82                 return 0;
  83
  84         /* Make sure targets are unloaded on shutdown */
  85         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  86 }
  87
  88 static int target_load(Unit *u) {
  89         Target *t = TARGET(u);
  90         int r;
  91
  92         assert(t);
  93
  94         r = unit_load_fragment_and_dropin(u);
  95         if (r < 0)
  96                 return r;
  97
  98         /* This is a new unit? Then let's add in some extras */
  99         if (u->load_state == UNIT_LOADED) {
 100                 r = target_add_default_dependencies(t);
 101                 if (r < 0)
 102                         return r;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static int target_coldplug(Unit *u) {
 109         Target *t = TARGET(u);
 110
 111         assert(t);
 112         assert(t->state == TARGET_DEAD);
 113
 114         if (t->deserialized_state != t->state)
 115                 target_set_state(t, t->deserialized_state);
 116
 117         return 0;
 118 }
 119
 120 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 121         Target *t = TARGET(u);
 122
 123         assert(t);
 124         assert(f);
 125
 126         fprintf(f,
 127                 "%sTarget State: %s\n",
 128                 prefix, target_state_to_string(t->state));
 129 }
 130
 131 static int target_start(Unit *u) {
 132         Target *t = TARGET(u);
 133         int r;
 134
 135         assert(t);
 136         assert(t->state == TARGET_DEAD);
 137
 138         r = unit_acquire_invocation_id(u);
 139         if (r < 0)
 140                 return r;
 141
 142         target_set_state(t, TARGET_ACTIVE);
 143         return 1;
 144 }
 145
 146 static int target_stop(Unit *u) {
 147         Target *t = TARGET(u);
 148
 149         assert(t);
 150         assert(t->state == TARGET_ACTIVE);
 151
 152         target_set_state(t, TARGET_DEAD);
 153         return 1;
 154 }
 155
 156 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 157         Target *s = TARGET(u);
 158
 159         assert(s);
 160         assert(f);
 161         assert(fds);
 162
 163         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 164         return 0;
 165 }
 166
 167 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 168         Target *s = TARGET(u);
 169
 170         assert(u);
 171         assert(key);
 172         assert(value);
 173         assert(fds);
 174
 175         if (streq(key, "state")) {
 176                 TargetState state;
 177
 178                 state = target_state_from_string(value);
 179                 if (state < 0)
 180                         log_debug("Failed to parse state value %s", value);
 181                 else
 182                         s->deserialized_state = state;
 183
 184         } else
 185                 log_debug("Unknown serialization key '%s'", key);
 186
 187         return 0;
 188 }
 189
 190 _pure_ static UnitActiveState target_active_state(Unit *u) {
 191         assert(u);
 192
 193         return state_translation_table[TARGET(u)->state];
 194 }
 195
 196 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 197         assert(u);
 198
 199         return target_state_to_string(TARGET(u)->state);
 200 }
 201
 202 const UnitVTable target_vtable = {
 203         .object_size = sizeof(Target),
 204
 205         .sections =
 206                 "Unit\0"
 207                 "Target\0"
 208                 "Install\0",
 209
 210         .load = target_load,
 211         .coldplug = target_coldplug,
 212
 213         .dump = target_dump,
 214
 215         .start = target_start,
 216         .stop = target_stop,
 217
 218         .serialize = target_serialize,
 219         .deserialize_item = target_deserialize_item,
 220
 221         .active_state = target_active_state,
 222         .sub_state_to_string = target_sub_state_to_string,
 223
 224         .bus_vtable = bus_target_vtable,
 225
 226         .status_message_formats = {
 227                 .finished_start_job = {
 228                         [JOB_DONE]       = "Reached target %s.",
 229                 },
 230                 .finished_stop_job = {
 231                         [JOB_DONE]       = "Stopped target %s.",
 232                 },
 233         },
 234 };