src/core/target.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include "dbus-target.h"
  21 #include "log.h"
  22 #include "special.h"
  23 #include "string-util.h"
  24 #include "unit-name.h"
  25 #include "unit.h"
  26 #include "target.h"
  27
  28 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  29         [TARGET_DEAD] = UNIT_INACTIVE,
  30         [TARGET_ACTIVE] = UNIT_ACTIVE
  31 };
  32
  33 static void target_set_state(Target *t, TargetState state) {
  34         TargetState old_state;
  35         assert(t);
  36
  37         old_state = t->state;
  38         t->state = state;
  39
  40         if (state != old_state)
  41                 log_debug("%s changed %s -> %s",
  42                           UNIT(t)->id,
  43                           target_state_to_string(old_state),
  44                           target_state_to_string(state));
  45
  46         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  47 }
  48
  49 static int target_add_default_dependencies(Target *t) {
  50
  51         static const UnitDependency deps[] = {
  52                 UNIT_REQUIRES,
  53                 UNIT_REQUISITE,
  54                 UNIT_WANTS,
  55                 UNIT_BINDS_TO,
  56                 UNIT_PART_OF
  57         };
  58
  59         Iterator i;
  60         Unit *other;
  61         int r;
  62         unsigned k;
  63
  64         assert(t);
  65
  66         /* Imply ordering for requirement dependencies on target
  67          * units. Note that when the user created a contradicting
  68          * ordering manually we won't add anything in here to make
  69          * sure we don't create a loop. */
  70
  71         for (k = 0; k < ELEMENTSOF(deps); k++)
  72                 SET_FOREACH(other, UNIT(t)->dependencies[deps[k]], i) {
  73                         r = unit_add_default_target_dependency(other, UNIT(t));
  74                         if (r < 0)
  75                                 return r;
  76                 }
  77
  78         /* Make sure targets are unloaded on shutdown */
  79         return unit_add_dependency_by_name(UNIT(t), UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  80 }
  81
  82 static int target_load(Unit *u) {
  83         Target *t = TARGET(u);
  84         int r;
  85
  86         assert(t);
  87
  88         r = unit_load_fragment_and_dropin(u);
  89         if (r < 0)
  90                 return r;
  91
  92         /* This is a new unit? Then let's add in some extras */
  93         if (u->load_state == UNIT_LOADED && u->default_dependencies) {
  94                 r = target_add_default_dependencies(t);
  95                 if (r < 0)
  96                         return r;
  97         }
  98
  99         return 0;
 100 }
 101
 102 static int target_coldplug(Unit *u) {
 103         Target *t = TARGET(u);
 104
 105         assert(t);
 106         assert(t->state == TARGET_DEAD);
 107
 108         if (t->deserialized_state != t->state)
 109                 target_set_state(t, t->deserialized_state);
 110
 111         return 0;
 112 }
 113
 114 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 115         Target *t = TARGET(u);
 116
 117         assert(t);
 118         assert(f);
 119
 120         fprintf(f,
 121                 "%sTarget State: %s\n",
 122                 prefix, target_state_to_string(t->state));
 123 }
 124
 125 static int target_start(Unit *u) {
 126         Target *t = TARGET(u);
 127         int r;
 128
 129         assert(t);
 130         assert(t->state == TARGET_DEAD);
 131
 132         r = unit_acquire_invocation_id(u);
 133         if (r < 0)
 134                 return r;
 135
 136         target_set_state(t, TARGET_ACTIVE);
 137         return 1;
 138 }
 139
 140 static int target_stop(Unit *u) {
 141         Target *t = TARGET(u);
 142
 143         assert(t);
 144         assert(t->state == TARGET_ACTIVE);
 145
 146         target_set_state(t, TARGET_DEAD);
 147         return 1;
 148 }
 149
 150 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 151         Target *s = TARGET(u);
 152
 153         assert(s);
 154         assert(f);
 155         assert(fds);
 156
 157         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 158         return 0;
 159 }
 160
 161 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 162         Target *s = TARGET(u);
 163
 164         assert(u);
 165         assert(key);
 166         assert(value);
 167         assert(fds);
 168
 169         if (streq(key, "state")) {
 170                 TargetState state;
 171
 172                 state = target_state_from_string(value);
 173                 if (state < 0)
 174                         log_debug("Failed to parse state value %s", value);
 175                 else
 176                         s->deserialized_state = state;
 177
 178         } else
 179                 log_debug("Unknown serialization key '%s'", key);
 180
 181         return 0;
 182 }
 183
 184 _pure_ static UnitActiveState target_active_state(Unit *u) {
 185         assert(u);
 186
 187         return state_translation_table[TARGET(u)->state];
 188 }
 189
 190 _pure_ static const char *target_sub_state_to_string(Unit *u) {
 191         assert(u);
 192
 193         return target_state_to_string(TARGET(u)->state);
 194 }
 195
 196 const UnitVTable target_vtable = {
 197         .object_size = sizeof(Target),
 198
 199         .sections =
 200                 "Unit\0"
 201                 "Target\0"
 202                 "Install\0",
 203
 204         .load = target_load,
 205         .coldplug = target_coldplug,
 206
 207         .dump = target_dump,
 208
 209         .start = target_start,
 210         .stop = target_stop,
 211
 212         .serialize = target_serialize,
 213         .deserialize_item = target_deserialize_item,
 214
 215         .active_state = target_active_state,
 216         .sub_state_to_string = target_sub_state_to_string,
 217
 218         .bus_vtable = bus_target_vtable,
 219
 220         .status_message_formats = {
 221                 .finished_start_job = {
 222                         [JOB_DONE]       = "Reached target %s.",
 223                 },
 224                 .finished_stop_job = {
 225                         [JOB_DONE]       = "Stopped target %s.",
 226                 },
 227         },
 228 };