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
  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 on target
  59          * units. Note that when the user created a contradicting
  60          * ordering manually we won't add anything in here to make
  61          * sure we don't create a loop. */
  62
  63         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES], i)
  64                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  65                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  66                                 return r;
  67         SET_FOREACH(other, t->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
  68                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  69                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  70                                 return r;
  71         SET_FOREACH(other, t->meta.dependencies[UNIT_WANTS], i)
  72                 if (!set_get(t->meta.dependencies[UNIT_BEFORE], other))
  73                         if ((r = unit_add_dependency(UNIT(t), UNIT_AFTER, other, true)) < 0)
  74                                 return r;
  75
  76         return 0;
  77 }
  78
  79 static int target_load(Unit *u) {
  80         Target *t = TARGET(u);
  81         int r;
  82
  83         assert(t);
  84
  85         if ((r = unit_load_fragment_and_dropin(u)) < 0)
  86                 return r;
  87
  88         /* This is a new unit? Then let's add in some extras */
  89         if (u->meta.load_state == UNIT_LOADED) {
  90                 if (u->meta.default_dependencies)
  91                         if ((r = target_add_default_dependencies(t)) < 0)
  92                                 return r;
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int target_coldplug(Unit *u) {
  99         Target *t = TARGET(u);
 100
 101         assert(t);
 102         assert(t->state == TARGET_DEAD);
 103
 104         if (t->deserialized_state != t->state)
 105                 target_set_state(t, t->deserialized_state);
 106
 107         return 0;
 108 }
 109
 110 static void target_dump(Unit *u, FILE *f, const char *prefix) {
 111         Target *t = TARGET(u);
 112
 113         assert(t);
 114         assert(f);
 115
 116         fprintf(f,
 117                 "%sTarget State: %s\n",
 118                 prefix, target_state_to_string(t->state));
 119 }
 120
 121 static int target_start(Unit *u) {
 122         Target *t = TARGET(u);
 123
 124         assert(t);
 125         assert(t->state == TARGET_DEAD);
 126
 127         target_set_state(t, TARGET_ACTIVE);
 128         return 0;
 129 }
 130
 131 static int target_stop(Unit *u) {
 132         Target *t = TARGET(u);
 133
 134         assert(t);
 135         assert(t->state == TARGET_ACTIVE);
 136
 137         target_set_state(t, TARGET_DEAD);
 138         return 0;
 139 }
 140
 141 static int target_serialize(Unit *u, FILE *f, FDSet *fds) {
 142         Target *s = TARGET(u);
 143
 144         assert(s);
 145         assert(f);
 146         assert(fds);
 147
 148         unit_serialize_item(u, f, "state", target_state_to_string(s->state));
 149         return 0;
 150 }
 151
 152 static int target_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 153         Target *s = TARGET(u);
 154
 155         assert(u);
 156         assert(key);
 157         assert(value);
 158         assert(fds);
 159
 160         if (streq(key, "state")) {
 161                 TargetState state;
 162
 163                 if ((state = target_state_from_string(value)) < 0)
 164                         log_debug("Failed to parse state value %s", value);
 165                 else
 166                         s->deserialized_state = state;
 167
 168         } else
 169                 log_debug("Unknown serialization key '%s'", key);
 170
 171         return 0;
 172 }
 173
 174 static UnitActiveState target_active_state(Unit *u) {
 175         assert(u);
 176
 177         return state_translation_table[TARGET(u)->state];
 178 }
 179
 180 static const char *target_sub_state_to_string(Unit *u) {
 181         assert(u);
 182
 183         return target_state_to_string(TARGET(u)->state);
 184 }
 185
 186 static const char* const target_state_table[_TARGET_STATE_MAX] = {
 187         [TARGET_DEAD] = "dead",
 188         [TARGET_ACTIVE] = "active"
 189 };
 190
 191 DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 192
 193 const UnitVTable target_vtable = {
 194         .suffix = ".target",
 195
 196         .load = target_load,
 197         .coldplug = target_coldplug,
 198
 199         .dump = target_dump,
 200
 201         .start = target_start,
 202         .stop = target_stop,
 203
 204         .serialize = target_serialize,
 205         .deserialize_item = target_deserialize_item,
 206
 207         .active_state = target_active_state,
 208         .sub_state_to_string = target_sub_state_to_string,
 209
 210         .bus_message_handler = bus_target_message_handler
 211 };