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