src/target.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <unistd.h>
  25
  26 #include "unit.h"
  27 #include "target.h"
  28 #include "load-fragment.h"
  29 #include "log.h"
  30 #include "dbus-target.h"
  31 #include "special.h"
  32 #include "unit-name.h"
  33
  34 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  35         [TARGET_DEAD] = UNIT_INACTIVE,
  36         [TARGET_ACTIVE] = UNIT_ACTIVE
  37 };
  38
  39 static void target_set_state(Target *t, TargetState state) {
  40         TargetState old_state;
  41         assert(t);
  42
  43         old_state = t->state;
  44         t->state = state;
  45
  46         if (state != old_state)
  47                 log_debug("%s changed %s -> %s",
  48                           t->meta.id,
  49                           target_state_to_string(old_state),
  50                           target_state_to_string(state));
  51
  52         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
  53 }
  54
  55 static int target_add_default_dependencies(Target *t) {
  56         Iterator i;
  57         Unit *other;
  58         int r;
  59
  60         /* Imply ordering for requirement dependencies on target
  61          * units. Note that when the user created a contradicting
  62          * ordering manually we won't add anything in here to make
  63          * sure we don't create a loop. */
  64
  65         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES], i)
  66                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  67                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  68                                 return r;
  69         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
  70                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  71                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  72                                 return r;
  73         SET_FOREACH(other, t->meta.dependencies[UNIT_WANTS], i)
  74                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  75                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  76                                 return r;
  77
  78         /* Make sure targets are unloaded on shutdown */
  79         return unit_add_dependency_by_name(UNIT(t), UNIT_CONFLICTED_BY, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  80 }
  81
  82 static int target_add_getty_dependencies(Target *t) {
  83         char *n;
  84         int r;
  85
  86         assert(t);
  87
  88         if (!unit_has_name(UNIT(t), SPECIAL_GETTY_TARGET))
  89                 return 0;
  90
  91         /* Automatically add in a serial getty on the kernel
  92          * console */
  93         if (t->meta.manager->console) {
  94                 log_debug("Automatically adding serial getty for %s", t->meta.manager->console);
  95                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, t->meta.manager->console)))
  96                         return -ENOMEM;
  97
  98                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
  99                 free(n);
 100
 101                 if (r < 0)
 102                         return r;
 103         }
 104
 105         /* Automatically add in a serial getty on the first
 106          * virtualizer console */
 107         if (access("/sys/class/tty/hvc0", F_OK) == 0) {
 108                 log_debug("Automatic adding serial getty for hvc0");
 109                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, "hvc0")))
 110                         return -ENOMEM;
 111
 112                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
 113                 free(n);
 114
 115                 if (r < 0)
 116                         return r;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int target_load(Unit *u) {
 123         Target *t = TARGET(u);
 124         int r;
 125
 126         assert(t);
 127
 128         if ((r = unit_load_fragment_and_dropin(u)) < 0)
 129                 return r;
 130
 131         /* This is a new unit? Then let's add in some extras */
 132         if (u->meta.load_state == UNIT_LOADED) {
 133                 if (u->meta.default_dependencies)
 134                         if ((r = target_add_default_dependencies(t)) < 0)
 135                                 return r;
 136
 137                 if ((r = target_add_getty_dependencies(t)) < 0)
 138                         return r;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int target_coldplug(Unit *u) {
 145         Target *t = TARGET(u);
 146
 147         assert(t);
 148         assert(t->state == TARGET_DEAD);
 149
 150         if (t->deserialized_state != t->state)
 151                 target_set_state(t, t->deserialized_state);
 152
 153         return 0;
 154 }
 155
 156 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 157         Target *t = TARGET(u);
 158
 159         assert(t);
 160         assert(f);
 161
 162         fprintf(f,
 163                 "%sTarget State: %s\n",
 164                 prefix, target_state_to_string(t->state));
 165 }
 166
 167 static int target_start(Unit *u) {
 168         Target *t = TARGET(u);
 169
 170         assert(t);
 171         assert(t->state == TARGET_DEAD);
 172
 173         target_set_state(t, TARGET_ACTIVE);
 174         return 0;
 175 }
 176
 177 static int target_stop(Unit *u) {
 178         Target *t = TARGET(u);
 179
 180         assert(t);
 181         assert(t->state == TARGET_ACTIVE);
 182
 183         target_set_state(t, TARGET_DEAD);
 184         return 0;
 185 }
 186
 187 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 188         Target *s = TARGET(u);
 189
 190         assert(s);
 191         assert(f);
 192         assert(fds);
 193
 194         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 195         return 0;
 196 }
 197
 198 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 199         Target *s = TARGET(u);
 200
 201         assert(u);
 202         assert(key);
 203         assert(value);
 204         assert(fds);
 205
 206         if (streq(key, "state")) {
 207                 TargetState state;
 208
 209                 if ((state = target_state_from_string(value)) < 0)
 210                         log_debug("Failed to parse state value %s", value);
 211                 else
 212                         s->deserialized_state = state;
 213
 214         } else
 215                 log_debug("Unknown serialization key '%s'", key);
 216
 217         return 0;
 218 }
 219
 220 static UnitActiveState target_active_state(Unit *u) {
 221         assert(u);
 222
 223         return state_translation_table[TARGET(u)->state];
 224 }
 225
 226 static const char *target_sub_state_to_string(Unit *u) {
 227         assert(u);
 228
 229         return target_state_to_string(TARGET(u)->state);
 230 }
 231
 232 static const char* const target_state_table[_TARGET_STATE_MAX] = {
 233         [TARGET_DEAD] = "dead",
 234         [TARGET_ACTIVE] = "active"
 235 };
 236
 237 DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 238
 239 const UnitVTable target_vtable = {
 240         .suffix = ".target",
 241
 242         .load = target_load,
 243         .coldplug = target_coldplug,
 244
 245         .dump = target_dump,
 246
 247         .start = target_start,
 248         .stop = target_stop,
 249
 250         .serialize = target_serialize,
 251         .deserialize_item = target_deserialize_item,
 252
 253         .active_state = target_active_state,
 254         .sub_state_to_string = target_sub_state_to_string,
 255
 256         .bus_interface = "org.freedesktop.systemd1.Target",
 257         .bus_message_handler = bus_target_message_handler
 258 };