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         return 0;
  79 }
  80
  81 static int target_add_getty_dependencies(Target *t) {
  82         char *n;
  83         int r;
  84
  85         assert(t);
  86
  87         if (!unit_has_name(UNIT(t), SPECIAL_GETTY_TARGET))
  88                 return 0;
  89
  90         /* Automatically add in a serial getty on the kernel
  91          * console */
  92         if (t->meta.manager->console) {
  93                 log_debug("Automatically adding serial getty for %s", t->meta.manager->console);
  94                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, t->meta.manager->console)))
  95                         return -ENOMEM;
  96
  97                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
  98                 free(n);
  99
 100                 if (r < 0)
 101                         return r;
 102         }
 103
 104         /* Automatically add in a serial getty on the first
 105          * virtualizer console */
 106         if (access("/sys/class/tty/hvc0", F_OK) == 0) {
 107                 log_debug("Automatic adding serial getty for hvc0");
 108                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, "hvc0")))
 109                         return -ENOMEM;
 110
 111                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
 112                 free(n);
 113
 114                 if (r < 0)
 115                         return r;
 116         }
 117
 118         return 0;
 119 }
 120
 121 static int target_load(Unit *u) {
 122         Target *t = TARGET(u);
 123         int r;
 124
 125         assert(t);
 126
 127         if ((r = unit_load_fragment_and_dropin(u)) < 0)
 128                 return r;
 129
 130         /* This is a new unit? Then let's add in some extras */
 131         if (u->meta.load_state == UNIT_LOADED) {
 132                 if (u->meta.default_dependencies)
 133                         if ((r = target_add_default_dependencies(t)) < 0)
 134                                 return r;
 135
 136                 if ((r = target_add_getty_dependencies(t)) < 0)
 137                         return r;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int target_coldplug(Unit *u) {
 144         Target *t = TARGET(u);
 145
 146         assert(t);
 147         assert(t->state == TARGET_DEAD);
 148
 149         if (t->deserialized_state != t->state)
 150                 target_set_state(t, t->deserialized_state);
 151
 152         return 0;
 153 }
 154
 155 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 156         Target *t = TARGET(u);
 157
 158         assert(t);
 159         assert(f);
 160
 161         fprintf(f,
 162                 "%sTarget State: %s\n",
 163                 prefix, target_state_to_string(t->state));
 164 }
 165
 166 static int target_start(Unit *u) {
 167         Target *t = TARGET(u);
 168
 169         assert(t);
 170         assert(t->state == TARGET_DEAD);
 171
 172         target_set_state(t, TARGET_ACTIVE);
 173         return 0;
 174 }
 175
 176 static int target_stop(Unit *u) {
 177         Target *t = TARGET(u);
 178
 179         assert(t);
 180         assert(t->state == TARGET_ACTIVE);
 181
 182         target_set_state(t, TARGET_DEAD);
 183         return 0;
 184 }
 185
 186 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 187         Target *s = TARGET(u);
 188
 189         assert(s);
 190         assert(f);
 191         assert(fds);
 192
 193         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 194         return 0;
 195 }
 196
 197 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 198         Target *s = TARGET(u);
 199
 200         assert(u);
 201         assert(key);
 202         assert(value);
 203         assert(fds);
 204
 205         if (streq(key, "state")) {
 206                 TargetState state;
 207
 208                 if ((state = target_state_from_string(value)) < 0)
 209                         log_debug("Failed to parse state value %s", value);
 210                 else
 211                         s->deserialized_state = state;
 212
 213         } else
 214                 log_debug("Unknown serialization key '%s'", key);
 215
 216         return 0;
 217 }
 218
 219 static UnitActiveState target_active_state(Unit *u) {
 220         assert(u);
 221
 222         return state_translation_table[TARGET(u)->state];
 223 }
 224
 225 static const char *target_sub_state_to_string(Unit *u) {
 226         assert(u);
 227
 228         return target_state_to_string(TARGET(u)->state);
 229 }
 230
 231 static const char* const target_state_table[_TARGET_STATE_MAX] = {
 232         [TARGET_DEAD] = "dead",
 233         [TARGET_ACTIVE] = "active"
 234 };
 235
 236 DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 237
 238 const UnitVTable target_vtable = {
 239         .suffix = ".target",
 240
 241         .load = target_load,
 242         .coldplug = target_coldplug,
 243
 244         .dump = target_dump,
 245
 246         .start = target_start,
 247         .stop = target_stop,
 248
 249         .serialize = target_serialize,
 250         .deserialize_item = target_deserialize_item,
 251
 252         .active_state = target_active_state,
 253         .sub_state_to_string = target_sub_state_to_string,
 254
 255         .bus_interface = "org.freedesktop.systemd1.Target",
 256         .bus_message_handler = bus_target_message_handler
 257 };