src/core/target.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include "dbus-target.h"
   4 #include "dbus-unit.h"
   5 #include "log.h"
   6 #include "serialize.h"
   7 #include "special.h"
   8 #include "string-util.h"
   9 #include "target.h"
  10 #include "unit-name.h"
  11 #include "unit.h"
  12
  13 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  14         [TARGET_DEAD] = UNIT_INACTIVE,
  15         [TARGET_ACTIVE] = UNIT_ACTIVE
  16 };
  17
  18 static void target_set_state(Target *t, TargetState state) {
  19         TargetState old_state;
  20         assert(t);
  21
  22         if (t->state != state)
  23                 bus_unit_send_pending_change_signal(UNIT(t), false);
  24
  25         old_state = t->state;
  26         t->state = state;
  27
  28         if (state != old_state)
  29                 log_debug("%s changed %s -> %s",
  30                           UNIT(t)->id,
  31                           target_state_to_string(old_state),
  32                           target_state_to_string(state));
  33
  34         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], 0);
  35 }
  36
  37 static int target_add_default_dependencies(Target *t) {
  38
  39         static const UnitDependency deps[] = {
  40                 UNIT_REQUIRES,
  41                 UNIT_REQUISITE,
  42                 UNIT_WANTS,
  43                 UNIT_BINDS_TO,
  44                 UNIT_PART_OF
  45         };
  46
  47         int r;
  48         unsigned k;
  49
  50         assert(t);
  51
  52         if (!UNIT(t)->default_dependencies)
  53                 return 0;
  54
  55         /* Imply ordering for requirement dependencies on target units. Note that when the user created a contradicting
  56          * ordering manually we won't add anything in here to make sure we don't create a loop. */
  57
  58         for (k = 0; k < ELEMENTSOF(deps); k++) {
  59                 Unit *other;
  60                 Iterator i;
  61                 void *v;
  62
  63                 HASHMAP_FOREACH_KEY(v, other, UNIT(t)->dependencies[deps[k]], i) {
  64                         r = unit_add_default_target_dependency(other, UNIT(t));
  65                         if (r < 0)
  66                                 return r;
  67                 }
  68         }
  69
  70         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  71                 return 0;
  72
  73         /* Make sure targets are unloaded on shutdown */
  74         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  75 }
  76
  77 static int target_load(Unit *u) {
  78         Target *t = TARGET(u);
  79         int r;
  80
  81         assert(t);
  82
  83         r = unit_load_fragment_and_dropin(u, true);
  84         if (r < 0)
  85                 return r;
  86
  87         /* This is a new unit? Then let's add in some extras */
  88         if (u->load_state == UNIT_LOADED) {
  89                 r = target_add_default_dependencies(t);
  90                 if (r < 0)
  91                         return r;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int target_coldplug(Unit *u) {
  98         Target *t = TARGET(u);
  99
 100         assert(t);
 101         assert(t->state == TARGET_DEAD);
 102
 103         if (t->deserialized_state != t->state)
 104                 target_set_state(t, t->deserialized_state);
 105
 106         return 0;
 107 }
 108
 109 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 110         Target *t = TARGET(u);
 111
 112         assert(t);
 113         assert(f);
 114
 115         fprintf(f,
 116                 "%sTarget State: %s\n",
 117                 prefix, target_state_to_string(t->state));
 118 }
 119
 120 static int target_start(Unit *u) {
 121         Target *t = TARGET(u);
 122         int r;
 123
 124         assert(t);
 125         assert(t->state == TARGET_DEAD);
 126
 127         r = unit_acquire_invocation_id(u);
 128         if (r < 0)
 129                 return r;
 130
 131         target_set_state(t, TARGET_ACTIVE);
 132         return 1;
 133 }
 134
 135 static int target_stop(Unit *u) {
 136         Target *t = TARGET(u);
 137
 138         assert(t);
 139         assert(t->state == TARGET_ACTIVE);
 140
 141         target_set_state(t, TARGET_DEAD);
 142         return 1;
 143 }
 144
 145 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 146         Target *s = TARGET(u);
 147
 148         assert(s);
 149         assert(f);
 150         assert(fds);
 151
 152         (void) serialize_item(f, "state", target_state_to_string(s->state));
 153         return 0;
 154 }
 155
 156 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 157         Target *s = TARGET(u);
 158
 159         assert(u);
 160         assert(key);
 161         assert(value);
 162         assert(fds);
 163
 164         if (streq(key, "state")) {
 165                 TargetState state;
 166
 167                 state = target_state_from_string(value);
 168                 if (state < 0)
 169                         log_debug("Failed to parse state value %s", value);
 170                 else
 171                         s->deserialized_state = state;
 172
 173         } else
 174                 log_debug("Unknown serialization key '%s'", key);
 175
 176         return 0;
 177 }
 178
 179 _pure_ static UnitActiveState target_active_state(Unit *u) {
 180         assert(u);
 181
 182         return state_translation_table[TARGET(u)->state];
 183 }
 184
 185 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 186         assert(u);
 187
 188         return target_state_to_string(TARGET(u)->state);
 189 }
 190
 191 const UnitVTable target_vtable = {
 192         .object_size = sizeof(Target),
 193
 194         .sections =
 195                 "Unit\0"
 196                 "Target\0"
 197                 "Install\0",
 198
 199         .load = target_load,
 200         .coldplug = target_coldplug,
 201
 202         .dump = target_dump,
 203
 204         .start = target_start,
 205         .stop = target_stop,
 206
 207         .serialize = target_serialize,
 208         .deserialize_item = target_deserialize_item,
 209
 210         .active_state = target_active_state,
 211         .sub_state_to_string = target_sub_state_to_string,
 212
 213         .bus_vtable = bus_target_vtable,
 214
 215         .status_message_formats = {
 216                 .finished_start_job = {
 217                         [JOB_DONE]       = "Reached target %s.",
 218                 },
 219                 .finished_stop_job = {
 220                         [JOB_DONE]       = "Stopped target %s.",
 221                 },
 222         },
 223 };