src/target.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   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
  25 #include "unit.h"
  26 #include "target.h"
  27 #include "load-fragment.h"
  28 #include "log.h"
  29 #include "dbus-target.h"
  30 #include "special.h"
  31
  32 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
  33         [TARGET_DEAD] = UNIT_INACTIVE,
  34         [TARGET_ACTIVE] = UNIT_ACTIVE
  35 };
  36
  37 static void target_set_state(Target *t, TargetState state) {
  38         TargetState old_state;
  39         assert(t);
  40
  41         old_state = t->state;
  42         t->state = state;
  43
  44         if (state != old_state)
  45                 log_debug("%s changed %s -> %s",
  46                           t->meta.id,
  47                           target_state_to_string(old_state),
  48                           target_state_to_string(state));
  49
  50         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
  51 }
  52
  53 static int target_add_default_dependencies(Target *t) {
  54         Iterator i;
  55         Unit *other;
  56         int r;
  57
  58         /* Imply ordering for requirement dependencies
  59          * on target units. */
  60
  61         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES], i)
  62                 if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  63                         return r;
  64         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
  65                 if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  66                         return r;
  67         SET_FOREACH(other, t->meta.dependencies[UNIT_WANTS], i)
  68                 if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  69                         return r;
  70
  71         return 0;
  72 }
  73
  74 static int target_load(Unit *u) {
  75         Target *t = TARGET(u);
  76         int r;
  77
  78         assert(t);
  79
  80         if ((r = unit_load_fragment_and_dropin(u)) < 0)
  81                 return r;
  82
  83         /* This is a new unit? Then let's add in some extras */
  84         if (u->meta.load_state == UNIT_LOADED) {
  85                 if (u->meta.default_dependencies)
  86                         if ((r = target_add_default_dependencies(t)) < 0)
  87                                 return r;
  88         }
  89
  90         return 0;
  91 }
  92
  93 static int target_coldplug(Unit *u) {
  94         Target *t = TARGET(u);
  95
  96         assert(t);
  97         assert(t->state == TARGET_DEAD);
  98
  99         if (t->deserialized_state != t->state)
 100                 target_set_state(t, t->deserialized_state);
 101
 102         return 0;
 103 }
 104
 105 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 106         Target *t = TARGET(u);
 107
 108         assert(t);
 109         assert(f);
 110
 111         fprintf(f,
 112                 "%sTarget State: %s\n",
 113                 prefix, target_state_to_string(t->state));
 114 }
 115
 116 static int target_start(Unit *u) {
 117         Target *t = TARGET(u);
 118
 119         assert(t);
 120         assert(t->state == TARGET_DEAD);
 121
 122         target_set_state(t, TARGET_ACTIVE);
 123         return 0;
 124 }
 125
 126 static int target_stop(Unit *u) {
 127         Target *t = TARGET(u);
 128
 129         assert(t);
 130         assert(t->state == TARGET_ACTIVE);
 131
 132         target_set_state(t, TARGET_DEAD);
 133         return 0;
 134 }
 135
 136 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 137         Target *s = TARGET(u);
 138
 139         assert(s);
 140         assert(f);
 141         assert(fds);
 142
 143         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 144         return 0;
 145 }
 146
 147 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 148         Target *s = TARGET(u);
 149
 150         assert(u);
 151         assert(key);
 152         assert(value);
 153         assert(fds);
 154
 155         if (streq(key, "state")) {
 156                 TargetState state;
 157
 158                 if ((state = target_state_from_string(value)) < 0)
 159                         log_debug("Failed to parse state value %s", value);
 160                 else
 161                         s->deserialized_state = state;
 162
 163         } else
 164                 log_debug("Unknown serialization key '%s'", key);
 165
 166         return 0;
 167 }
 168
 169 static UnitActiveState target_active_state(Unit *u) {
 170         assert(u);
 171
 172         return state_translation_table[TARGET(u)->state];
 173 }
 174
 175 static const char *target_sub_state_to_string(Unit *u) {
 176         assert(u);
 177
 178         return target_state_to_string(TARGET(u)->state);
 179 }
 180
 181 int target_get_runlevel(Target *t) {
 182
 183         static const struct {
 184                 const char *special;
 185                 const int runlevel;
 186         } table[] = {
 187                 { SPECIAL_RUNLEVEL5_TARGET, '5' },
 188                 { SPECIAL_RUNLEVEL4_TARGET, '4' },
 189                 { SPECIAL_RUNLEVEL3_TARGET, '3' },
 190                 { SPECIAL_RUNLEVEL2_TARGET, '2' },
 191                 { SPECIAL_RESCUE_TARGET,    '1' },
 192                 { SPECIAL_POWEROFF_TARGET,  '0' },
 193                 { SPECIAL_REBOOT_TARGET,    '6' },
 194         };
 195
 196         unsigned i;
 197
 198         assert(t);
 199
 200         /* Tries to determine if this is a SysV runlevel and returns
 201          * it if that is so. */
 202
 203         for (i = 0; i < ELEMENTSOF(table); i++)
 204                 if (unit_has_name(UNIT(t), table[i].special))
 205                         return table[i].runlevel;
 206
 207         return 0;
 208 }
 209
 210 static const char* const target_state_table[_TARGET_STATE_MAX] = {
 211         [TARGET_DEAD] = "dead",
 212         [TARGET_ACTIVE] = "active"
 213 };
 214
 215 DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 216
 217 const UnitVTable target_vtable = {
 218         .suffix = ".target",
 219
 220         .load = target_load,
 221         .coldplug = target_coldplug,
 222
 223         .dump = target_dump,
 224
 225         .start = target_start,
 226         .stop = target_stop,
 227
 228         .serialize = target_serialize,
 229         .deserialize_item = target_deserialize_item,
 230
 231         .active_state = target_active_state,
 232         .sub_state_to_string = target_sub_state_to_string,
 233
 234         .bus_message_handler = bus_target_message_handler
 235 };