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         assert(t);
  57
  58         /* Make sure targets are unloaded on shutdown */
  59         return unit_add_dependency_by_name(UNIT(t), UNIT_CONFLICTED_BY, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  60 }
  61
  62 static int target_add_getty_dependencies(Target *t) {
  63         char *n;
  64         int r;
  65
  66         assert(t);
  67
  68         if (!unit_has_name(UNIT(t), SPECIAL_GETTY_TARGET))
  69                 return 0;
  70
  71         /* Automatically add in a serial getty on the kernel
  72          * console */
  73         if (t->meta.manager->console) {
  74                 log_debug("Automatically adding serial getty for %s", t->meta.manager->console);
  75                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, t->meta.manager->console)))
  76                         return -ENOMEM;
  77
  78                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
  79                 free(n);
  80
  81                 if (r < 0)
  82                         return r;
  83         }
  84
  85         /* Automatically add in a serial getty on the first
  86          * virtualizer console */
  87         if (access("/sys/class/tty/hvc0", F_OK) == 0) {
  88                 log_debug("Automatic adding serial getty for hvc0");
  89                 if (!(n = unit_name_replace_instance(SPECIAL_SERIAL_GETTY_SERVICE, "hvc0")))
  90                         return -ENOMEM;
  91
  92                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_WANTS, n, NULL, true);
  93                 free(n);
  94
  95                 if (r < 0)
  96                         return r;
  97         }
  98
  99         return 0;
 100 }
 101
 102 static int target_load(Unit *u) {
 103         Target *t = TARGET(u);
 104         int r;
 105
 106         assert(t);
 107
 108         if ((r = unit_load_fragment_and_dropin(u)) < 0)
 109                 return r;
 110
 111         /* This is a new unit? Then let's add in some extras */
 112         if (u->meta.load_state == UNIT_LOADED) {
 113                 if (u->meta.default_dependencies)
 114                         if ((r = target_add_default_dependencies(t)) < 0)
 115                                 return r;
 116
 117                 if ((r = target_add_getty_dependencies(t)) < 0)
 118                         return r;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static int target_coldplug(Unit *u) {
 125         Target *t = TARGET(u);
 126
 127         assert(t);
 128         assert(t->state == TARGET_DEAD);
 129
 130         if (t->deserialized_state != t->state)
 131                 target_set_state(t, t->deserialized_state);
 132
 133         return 0;
 134 }
 135
 136 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 137         Target *t = TARGET(u);
 138
 139         assert(t);
 140         assert(f);
 141
 142         fprintf(f,
 143                 "%sTarget State: %s\n",
 144                 prefix, target_state_to_string(t->state));
 145 }
 146
 147 static int target_start(Unit *u) {
 148         Target *t = TARGET(u);
 149
 150         assert(t);
 151         assert(t->state == TARGET_DEAD);
 152
 153         target_set_state(t, TARGET_ACTIVE);
 154         return 0;
 155 }
 156
 157 static int target_stop(Unit *u) {
 158         Target *t = TARGET(u);
 159
 160         assert(t);
 161         assert(t->state == TARGET_ACTIVE);
 162
 163         target_set_state(t, TARGET_DEAD);
 164         return 0;
 165 }
 166
 167 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 168         Target *s = TARGET(u);
 169
 170         assert(s);
 171         assert(f);
 172         assert(fds);
 173
 174         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 175         return 0;
 176 }
 177
 178 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 179         Target *s = TARGET(u);
 180
 181         assert(u);
 182         assert(key);
 183         assert(value);
 184         assert(fds);
 185
 186         if (streq(key, "state")) {
 187                 TargetState state;
 188
 189                 if ((state = target_state_from_string(value)) < 0)
 190                         log_debug("Failed to parse state value %s", value);
 191                 else
 192                         s->deserialized_state = state;
 193
 194         } else
 195                 log_debug("Unknown serialization key '%s'", key);
 196
 197         return 0;
 198 }
 199
 200 static UnitActiveState target_active_state(Unit *u) {
 201         assert(u);
 202
 203         return state_translation_table[TARGET(u)->state];
 204 }
 205
 206 static const char *target_sub_state_to_string(Unit *u) {
 207         assert(u);
 208
 209         return target_state_to_string(TARGET(u)->state);
 210 }
 211
 212 static const char* const target_state_table[_TARGET_STATE_MAX] = {
 213         [TARGET_DEAD] = "dead",
 214         [TARGET_ACTIVE] = "active"
 215 };
 216
 217 DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 218
 219 const UnitVTable target_vtable = {
 220         .suffix = ".target",
 221
 222         .load = target_load,
 223         .coldplug = target_coldplug,
 224
 225         .dump = target_dump,
 226
 227         .start = target_start,
 228         .stop = target_stop,
 229
 230         .serialize = target_serialize,
 231         .deserialize_item = target_deserialize_item,
 232
 233         .active_state = target_active_state,
 234         .sub_state_to_string = target_sub_state_to_string,
 235
 236         .bus_interface = "org.freedesktop.systemd1.Target",
 237         .bus_message_handler = bus_target_message_handler
 238 };