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         int r;
  60         unsigned k;
  61
  62         assert(t);
  63
  64         if (!UNIT(t)->default_dependencies)
  65                 return 0;
  66
  67         /* Imply ordering for requirement dependencies on target units. Note that when the user created a contradicting
  68          * ordering manually we won't add anything in here to make sure we don't create a loop. */
  69
  70         for (k = 0; k < ELEMENTSOF(deps); k++) {
  71                 Unit *other;
  72                 Iterator i;
  73                 void *v;
  74
  75                 HASHMAP_FOREACH_KEY(v, 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
  82         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  83                 return 0;
  84
  85         /* Make sure targets are unloaded on shutdown */
  86         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT);
  87 }
  88
  89 static int target_load(Unit *u) {
  90         Target *t = TARGET(u);
  91         int r;
  92
  93         assert(t);
  94
  95         r = unit_load_fragment_and_dropin(u);
  96         if (r < 0)
  97                 return r;
  98
  99         /* This is a new unit? Then let's add in some extras */
 100         if (u->load_state == UNIT_LOADED) {
 101                 r = target_add_default_dependencies(t);
 102                 if (r < 0)
 103                         return r;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static int target_coldplug(Unit *u) {
 110         Target *t = TARGET(u);
 111
 112         assert(t);
 113         assert(t->state == TARGET_DEAD);
 114
 115         if (t->deserialized_state != t->state)
 116                 target_set_state(t, t->deserialized_state);
 117
 118         return 0;
 119 }
 120
 121 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 122         Target *t = TARGET(u);
 123
 124         assert(t);
 125         assert(f);
 126
 127         fprintf(f,
 128                 "%sTarget State: %s\n",
 129                 prefix, target_state_to_string(t->state));
 130 }
 131
 132 static int target_start(Unit *u) {
 133         Target *t = TARGET(u);
 134         int r;
 135
 136         assert(t);
 137         assert(t->state == TARGET_DEAD);
 138
 139         r = unit_acquire_invocation_id(u);
 140         if (r < 0)
 141                 return r;
 142
 143         target_set_state(t, TARGET_ACTIVE);
 144         return 1;
 145 }
 146
 147 static int target_stop(Unit *u) {
 148         Target *t = TARGET(u);
 149
 150         assert(t);
 151         assert(t->state == TARGET_ACTIVE);
 152
 153         target_set_state(t, TARGET_DEAD);
 154         return 1;
 155 }
 156
 157 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 158         Target *s = TARGET(u);
 159
 160         assert(s);
 161         assert(f);
 162         assert(fds);
 163
 164         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 165         return 0;
 166 }
 167
 168 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 169         Target *s = TARGET(u);
 170
 171         assert(u);
 172         assert(key);
 173         assert(value);
 174         assert(fds);
 175
 176         if (streq(key, "state")) {
 177                 TargetState state;
 178
 179                 state = target_state_from_string(value);
 180                 if (state < 0)
 181                         log_debug("Failed to parse state value %s", value);
 182                 else
 183                         s->deserialized_state = state;
 184
 185         } else
 186                 log_debug("Unknown serialization key '%s'", key);
 187
 188         return 0;
 189 }
 190
 191 _pure_ static UnitActiveState target_active_state(Unit *u) {
 192         assert(u);
 193
 194         return state_translation_table[TARGET(u)->state];
 195 }
 196
 197 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 198         assert(u);
 199
 200         return target_state_to_string(TARGET(u)->state);
 201 }
 202
 203 const UnitVTable target_vtable = {
 204         .object_size = sizeof(Target),
 205
 206         .sections =
 207                 "Unit\0"
 208                 "Target\0"
 209                 "Install\0",
 210
 211         .load = target_load,
 212         .coldplug = target_coldplug,
 213
 214         .dump = target_dump,
 215
 216         .start = target_start,
 217         .stop = target_stop,
 218
 219         .serialize = target_serialize,
 220         .deserialize_item = target_deserialize_item,
 221
 222         .active_state = target_active_state,
 223         .sub_state_to_string = target_sub_state_to_string,
 224
 225         .bus_vtable = bus_target_vtable,
 226
 227         .status_message_formats = {
 228                 .finished_start_job = {
 229                         [JOB_DONE]       = "Reached target %s.",
 230                 },
 231                 .finished_stop_job = {
 232                         [JOB_DONE]       = "Stopped target %s.",
 233                 },
 234         },
 235 };