src/core/target.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   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], /* reload_success = */ true);
  35 }
  36
  37 static int target_add_default_dependencies(Target *t) {
  38         _cleanup_free_ Unit **others = NULL;
  39         int r, n_others;
  40
  41         assert(t);
  42
  43         if (!UNIT(t)->default_dependencies)
  44                 return 0;
  45
  46         /* Imply ordering for requirement dependencies on target units. Note that when the user created a
  47          * contradicting ordering manually we won't add anything in here to make sure we don't create a
  48          * loop.
  49          *
  50          * Note that quite likely iterating through these dependencies will add new dependencies, which
  51          * conflicts with the hashmap-based iteration logic. Hence, instead of iterating through the
  52          * dependencies and acting on them as we go, first take an "atomic snapshot" of sorts and iterate
  53          * through that. */
  54
  55         n_others = unit_get_dependency_array(UNIT(t), UNIT_ATOM_ADD_DEFAULT_TARGET_DEPENDENCY_QUEUE, &others);
  56         if (n_others < 0)
  57                 return n_others;
  58
  59         for (int i = 0; i < n_others; i++) {
  60                 r = unit_add_default_target_dependency(others[i], UNIT(t));
  61                 if (r < 0)
  62                         return r;
  63         }
  64
  65         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  66                 return 0;
  67
  68         /* Make sure targets are unloaded on shutdown */
  69         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  70 }
  71
  72 static int target_load(Unit *u) {
  73         Target *t = TARGET(u);
  74         int r;
  75
  76         assert(t);
  77
  78         r = unit_load_fragment_and_dropin(u, true);
  79         if (r < 0)
  80                 return r;
  81
  82         if (u->load_state != UNIT_LOADED)
  83                 return 0;
  84
  85         /* This is a new unit? Then let's add in some extras */
  86         return target_add_default_dependencies(t);
  87 }
  88
  89 static int target_coldplug(Unit *u) {
  90         Target *t = TARGET(u);
  91
  92         assert(t);
  93         assert(t->state == TARGET_DEAD);
  94
  95         if (t->deserialized_state != t->state)
  96                 target_set_state(t, t->deserialized_state);
  97
  98         return 0;
  99 }
 100
 101 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 102         Target *t = TARGET(u);
 103
 104         assert(t);
 105         assert(f);
 106
 107         fprintf(f,
 108                 "%sTarget State: %s\n",
 109                 prefix, target_state_to_string(t->state));
 110 }
 111
 112 static int target_start(Unit *u) {
 113         Target *t = TARGET(u);
 114         int r;
 115
 116         assert(t);
 117         assert(t->state == TARGET_DEAD);
 118
 119         r = unit_acquire_invocation_id(u);
 120         if (r < 0)
 121                 return r;
 122
 123         target_set_state(t, TARGET_ACTIVE);
 124         return 1;
 125 }
 126
 127 static int target_stop(Unit *u) {
 128         Target *t = TARGET(u);
 129
 130         assert(t);
 131         assert(t->state == TARGET_ACTIVE);
 132
 133         target_set_state(t, TARGET_DEAD);
 134         return 1;
 135 }
 136
 137 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 138         Target *s = TARGET(u);
 139
 140         assert(s);
 141         assert(f);
 142         assert(fds);
 143
 144         (void) serialize_item(f, "state", target_state_to_string(s->state));
 145         return 0;
 146 }
 147
 148 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 149         Target *s = TARGET(u);
 150
 151         assert(s);
 152         assert(u);
 153         assert(key);
 154         assert(value);
 155         assert(fds);
 156
 157         if (streq(key, "state")) {
 158                 TargetState state;
 159
 160                 state = target_state_from_string(value);
 161                 if (state < 0)
 162                         log_debug("Failed to parse state value %s", value);
 163                 else
 164                         s->deserialized_state = state;
 165
 166         } else
 167                 log_debug("Unknown serialization key '%s'", key);
 168
 169         return 0;
 170 }
 171
 172 _pure_ static UnitActiveState target_active_state(Unit *u) {
 173         assert(u);
 174
 175         return state_translation_table[TARGET(u)->state];
 176 }
 177
 178 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 179         assert(u);
 180
 181         return target_state_to_string(TARGET(u)->state);
 182 }
 183
 184 const UnitVTable target_vtable = {
 185         .object_size = sizeof(Target),
 186
 187         .sections =
 188                 "Unit\0"
 189                 "Target\0"
 190                 "Install\0",
 191
 192         .can_fail = true,
 193
 194         .load = target_load,
 195         .coldplug = target_coldplug,
 196
 197         .dump = target_dump,
 198
 199         .start = target_start,
 200         .stop = target_stop,
 201
 202         .serialize = target_serialize,
 203         .deserialize_item = target_deserialize_item,
 204
 205         .active_state = target_active_state,
 206         .sub_state_to_string = target_sub_state_to_string,
 207
 208         .status_message_formats = {
 209                 .finished_start_job = {
 210                         [JOB_DONE]       = "Reached target %s.",
 211                 },
 212                 .finished_stop_job = {
 213                         [JOB_DONE]       = "Stopped target %s.",
 214                 },
 215         },
 216 };