src/core/target.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2010 Lennart Poettering
   4 ***/
   5
   6 #include "dbus-target.h"
   7 #include "log.h"
   8 #include "special.h"
   9 #include "string-util.h"
  10 #include "unit-name.h"
  11 #include "unit.h"
  12 #include "target.h"
  13
  14 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  15         [TARGET_DEAD] = UNIT_INACTIVE,
  16         [TARGET_ACTIVE] = UNIT_ACTIVE
  17 };
  18
  19 static void target_set_state(Target *t, TargetState state) {
  20         TargetState old_state;
  21         assert(t);
  22
  23         old_state = t->state;
  24         t->state = state;
  25
  26         if (state != old_state)
  27                 log_debug("%s changed %s -> %s",
  28                           UNIT(t)->id,
  29                           target_state_to_string(old_state),
  30                           target_state_to_string(state));
  31
  32         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], 0);
  33 }
  34
  35 static int target_add_default_dependencies(Target *t) {
  36
  37         static const UnitDependency deps[] = {
  38                 UNIT_REQUIRES,
  39                 UNIT_REQUISITE,
  40                 UNIT_WANTS,
  41                 UNIT_BINDS_TO,
  42                 UNIT_PART_OF
  43         };
  44
  45         int r;
  46         unsigned k;
  47
  48         assert(t);
  49
  50         if (!UNIT(t)->default_dependencies)
  51                 return 0;
  52
  53         /* Imply ordering for requirement dependencies on target units. Note that when the user created a contradicting
  54          * ordering manually we won't add anything in here to make sure we don't create a loop. */
  55
  56         for (k = 0; k < ELEMENTSOF(deps); k++) {
  57                 Unit *other;
  58                 Iterator i;
  59                 void *v;
  60
  61                 HASHMAP_FOREACH_KEY(v, other, UNIT(t)->dependencies[deps[k]], i) {
  62                         r = unit_add_default_target_dependency(other, UNIT(t));
  63                         if (r < 0)
  64                                 return r;
  65                 }
  66         }
  67
  68         if (unit_has_name(UNIT(t), SPECIAL_SHUTDOWN_TARGET))
  69                 return 0;
  70
  71         /* Make sure targets are unloaded on shutdown */
  72         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT);
  73 }
  74
  75 static int target_load(Unit *u) {
  76         Target *t = TARGET(u);
  77         int r;
  78
  79         assert(t);
  80
  81         r = unit_load_fragment_and_dropin(u);
  82         if (r < 0)
  83                 return r;
  84
  85         /* This is a new unit? Then let's add in some extras */
  86         if (u->load_state == UNIT_LOADED) {
  87                 r = target_add_default_dependencies(t);
  88                 if (r < 0)
  89                         return r;
  90         }
  91
  92         return 0;
  93 }
  94
  95 static int target_coldplug(Unit *u) {
  96         Target *t = TARGET(u);
  97
  98         assert(t);
  99         assert(t->state == TARGET_DEAD);
 100
 101         if (t->deserialized_state != t->state)
 102                 target_set_state(t, t->deserialized_state);
 103
 104         return 0;
 105 }
 106
 107 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 108         Target *t = TARGET(u);
 109
 110         assert(t);
 111         assert(f);
 112
 113         fprintf(f,
 114                 "%sTarget State: %s\n",
 115                 prefix, target_state_to_string(t->state));
 116 }
 117
 118 static int target_start(Unit *u) {
 119         Target *t = TARGET(u);
 120         int r;
 121
 122         assert(t);
 123         assert(t->state == TARGET_DEAD);
 124
 125         r = unit_acquire_invocation_id(u);
 126         if (r < 0)
 127                 return r;
 128
 129         target_set_state(t, TARGET_ACTIVE);
 130         return 1;
 131 }
 132
 133 static int target_stop(Unit *u) {
 134         Target *t = TARGET(u);
 135
 136         assert(t);
 137         assert(t->state == TARGET_ACTIVE);
 138
 139         target_set_state(t, TARGET_DEAD);
 140         return 1;
 141 }
 142
 143 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 144         Target *s = TARGET(u);
 145
 146         assert(s);
 147         assert(f);
 148         assert(fds);
 149
 150         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 151         return 0;
 152 }
 153
 154 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 155         Target *s = TARGET(u);
 156
 157         assert(u);
 158         assert(key);
 159         assert(value);
 160         assert(fds);
 161
 162         if (streq(key, "state")) {
 163                 TargetState state;
 164
 165                 state = target_state_from_string(value);
 166                 if (state < 0)
 167                         log_debug("Failed to parse state value %s", value);
 168                 else
 169                         s->deserialized_state = state;
 170
 171         } else
 172                 log_debug("Unknown serialization key '%s'", key);
 173
 174         return 0;
 175 }
 176
 177 _pure_ static UnitActiveState target_active_state(Unit *u) {
 178         assert(u);
 179
 180         return state_translation_table[TARGET(u)->state];
 181 }
 182
 183 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 184         assert(u);
 185
 186         return target_state_to_string(TARGET(u)->state);
 187 }
 188
 189 const UnitVTable target_vtable = {
 190         .object_size = sizeof(Target),
 191
 192         .sections =
 193                 "Unit\0"
 194                 "Target\0"
 195                 "Install\0",
 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         .bus_vtable = bus_target_vtable,
 212
 213         .status_message_formats = {
 214                 .finished_start_job = {
 215                         [JOB_DONE]       = "Reached target %s.",
 216                 },
 217                 .finished_stop_job = {
 218                         [JOB_DONE]       = "Stopped target %s.",
 219                 },
 220         },
 221 };