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                 void *v;
  61
  62                 HASHMAP_FOREACH_KEY(v, other, UNIT(t)->dependencies[deps[k]]) {
  63                         r = unit_add_default_target_dependency(other, UNIT(t));
  64                         if (r < 0)
  65                                 return r;
  66                 }
  67         }
  68
  69         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  70                 return 0;
  71
  72         /* Make sure targets are unloaded on shutdown */
  73         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  74 }
  75
  76 static int target_load(Unit *u) {
  77         Target *t = TARGET(u);
  78         int r;
  79
  80         assert(t);
  81
  82         r = unit_load_fragment_and_dropin(u, true);
  83         if (r < 0)
  84                 return r;
  85
  86         if (u->load_state != UNIT_LOADED)
  87                 return 0;
  88
  89         /* This is a new unit? Then let's add in some extras */
  90         return target_add_default_dependencies(t);
  91 }
  92
  93 static int target_coldplug(Unit *u) {
  94         Target *t = TARGET(u);
  95
  96         assert(t);
  97         assert(t->state == TARGET_DEAD);
  98
  99         if (t->deserialized_state != t->state)
 100                 target_set_state(t, t->deserialized_state);
 101
 102         return 0;
 103 }
 104
 105 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 106         Target *t = TARGET(u);
 107
 108         assert(t);
 109         assert(f);
 110
 111         fprintf(f,
 112                 "%sTarget State: %s\n",
 113                 prefix, target_state_to_string(t->state));
 114 }
 115
 116 static int target_start(Unit *u) {
 117         Target *t = TARGET(u);
 118         int r;
 119
 120         assert(t);
 121         assert(t->state == TARGET_DEAD);
 122
 123         r = unit_acquire_invocation_id(u);
 124         if (r < 0)
 125                 return r;
 126
 127         target_set_state(t, TARGET_ACTIVE);
 128         return 1;
 129 }
 130
 131 static int target_stop(Unit *u) {
 132         Target *t = TARGET(u);
 133
 134         assert(t);
 135         assert(t->state == TARGET_ACTIVE);
 136
 137         target_set_state(t, TARGET_DEAD);
 138         return 1;
 139 }
 140
 141 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 142         Target *s = TARGET(u);
 143
 144         assert(s);
 145         assert(f);
 146         assert(fds);
 147
 148         (void) serialize_item(f, "state", target_state_to_string(s->state));
 149         return 0;
 150 }
 151
 152 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 153         Target *s = TARGET(u);
 154
 155         assert(u);
 156         assert(key);
 157         assert(value);
 158         assert(fds);
 159
 160         if (streq(key, "state")) {
 161                 TargetState state;
 162
 163                 state = target_state_from_string(value);
 164                 if (state < 0)
 165                         log_debug("Failed to parse state value %s", value);
 166                 else
 167                         s->deserialized_state = state;
 168
 169         } else
 170                 log_debug("Unknown serialization key '%s'", key);
 171
 172         return 0;
 173 }
 174
 175 _pure_ static UnitActiveState target_active_state(Unit *u) {
 176         assert(u);
 177
 178         return state_translation_table[TARGET(u)->state];
 179 }
 180
 181 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 182         assert(u);
 183
 184         return target_state_to_string(TARGET(u)->state);
 185 }
 186
 187 const UnitVTable target_vtable = {
 188         .object_size = sizeof(Target),
 189
 190         .sections =
 191                 "Unit\0"
 192                 "Target\0"
 193                 "Install\0",
 194
 195         .can_fail = true,
 196
 197         .load = target_load,
 198         .coldplug = target_coldplug,
 199
 200         .dump = target_dump,
 201
 202         .start = target_start,
 203         .stop = target_stop,
 204
 205         .serialize = target_serialize,
 206         .deserialize_item = target_deserialize_item,
 207
 208         .active_state = target_active_state,
 209         .sub_state_to_string = target_sub_state_to_string,
 210
 211         .status_message_formats = {
 212                 .finished_start_job = {
 213                         [JOB_DONE]       = "Reached target %s.",
 214                 },
 215                 .finished_stop_job = {
 216                         [JOB_DONE]       = "Stopped target %s.",
 217                 },
 218         },
 219 };