main.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 <dbus/dbus.h>
  23
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <getopt.h>
  31
  32 #include "manager.h"
  33 #include "log.h"
  34 #include "mount-setup.h"
  35
  36 static enum {
  37         ACTION_RUN,
  38         ACTION_HELP,
  39         ACTION_TEST
  40 } action = ACTION_RUN;
  41
  42 static char *default_unit = NULL;
  43 static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID;
  44
  45 static int set_default_unit(const char *u) {
  46         char *c;
  47
  48         assert(u);
  49
  50         if (!(c = strdup(u)))
  51                 return -ENOMEM;
  52
  53         free(default_unit);
  54         default_unit = c;
  55         return 0;
  56 }
  57
  58 static int parse_proc_cmdline_word(const char *word) {
  59
  60         static const char * const rlmap[] = {
  61                 "single", SPECIAL_RUNLEVEL1_TARGET,
  62                 "-s",     SPECIAL_RUNLEVEL1_TARGET,
  63                 "s",      SPECIAL_RUNLEVEL1_TARGET,
  64                 "S",      SPECIAL_RUNLEVEL1_TARGET,
  65                 "1",      SPECIAL_RUNLEVEL1_TARGET,
  66                 "2",      SPECIAL_RUNLEVEL2_TARGET,
  67                 "3",      SPECIAL_RUNLEVEL3_TARGET,
  68                 "4",      SPECIAL_RUNLEVEL4_TARGET,
  69                 "5",      SPECIAL_RUNLEVEL5_TARGET
  70         };
  71
  72         if (startswith(word, "systemd.default="))
  73                 return set_default_unit(word + 16);
  74
  75         else if (startswith(word, "systemd.log_target=")) {
  76
  77                 if (log_set_target_from_string(word + 19) < 0)
  78                         log_warning("Failed to parse log target %s. Ignoring.", word + 19);
  79
  80         } else if (startswith(word, "systemd.log_level=")) {
  81
  82                 if (log_set_max_level_from_string(word + 18) < 0)
  83                         log_warning("Failed to parse log level %s. Ignoring.", word + 18);
  84
  85         } else {
  86                 unsigned i;
  87
  88                 /* SysV compatibility */
  89
  90                 for (i = 0; i < ELEMENTSOF(rlmap); i += 2)
  91                         if (streq(word, rlmap[i]))
  92                                 return set_default_unit(rlmap[i+1]);
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int parse_proc_cmdline(void) {
  99         char *line;
 100         int r;
 101         char *w;
 102         size_t l;
 103         char *state;
 104
 105         if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) {
 106                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno));
 107                 return 0;
 108         }
 109
 110         FOREACH_WORD_QUOTED(w, l, line, state) {
 111                 char *word;
 112
 113                 if (!(word = strndup(w, l))) {
 114                         r = -ENOMEM;
 115                         goto finish;
 116                 }
 117
 118                 r = parse_proc_cmdline_word(word);
 119                 free(word);
 120
 121                 if (r < 0)
 122                         goto finish;
 123         }
 124
 125         r = 0;
 126
 127 finish:
 128         free(line);
 129         return r;
 130 }
 131
 132 static int parse_argv(int argc, char *argv[]) {
 133
 134         enum {
 135                 ARG_LOG_LEVEL = 0x100,
 136                 ARG_LOG_TARGET,
 137                 ARG_DEFAULT,
 138                 ARG_RUNNING_AS,
 139                 ARG_TEST
 140         };
 141
 142         static const struct option options[] = {
 143                 { "log-level",  required_argument, NULL, ARG_LOG_LEVEL },
 144                 { "log-target", required_argument, NULL, ARG_LOG_TARGET },
 145                 { "default",    required_argument, NULL, ARG_DEFAULT },
 146                 { "running-as", required_argument, NULL, ARG_RUNNING_AS },
 147                 { "test",       no_argument,       NULL, ARG_TEST },
 148                 { "help",       no_argument,       NULL, 'h' },
 149                 { NULL,         0,                 NULL, 0 }
 150         };
 151
 152         int c, r;
 153
 154         assert(argc >= 1);
 155         assert(argv);
 156
 157         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
 158
 159                 switch (c) {
 160
 161                 case ARG_LOG_LEVEL:
 162                         if ((r = log_set_max_level_from_string(optarg)) < 0) {
 163                                 log_error("Failed to parse log level %s.", optarg);
 164                                 return r;
 165                         }
 166
 167                         break;
 168
 169                 case ARG_LOG_TARGET:
 170
 171                         if ((r = log_set_target_from_string(optarg)) < 0) {
 172                                 log_error("Failed to parse log target %s.", optarg);
 173                                 return r;
 174                         }
 175
 176                         break;
 177
 178                 case ARG_DEFAULT:
 179
 180                         if ((r = set_default_unit(optarg)) < 0) {
 181                                 log_error("Failed to set default unit %s: %s", optarg, strerror(-r));
 182                                 return r;
 183                         }
 184
 185                         break;
 186
 187                 case ARG_RUNNING_AS: {
 188                         ManagerRunningAs as;
 189
 190                         if ((as = manager_running_as_from_string(optarg)) < 0) {
 191                                 log_error("Failed to parse running as value %s", optarg);
 192                                 return -EINVAL;
 193                         }
 194
 195                         running_as = as;
 196                         break;
 197                 }
 198
 199                 case ARG_TEST:
 200                         action = ACTION_TEST;
 201                         break;
 202
 203                 case 'h':
 204                         action = ACTION_HELP;
 205                         break;
 206
 207                 case '?':
 208                         return -EINVAL;
 209
 210                 default:
 211                         log_error("Unknown option code %c", c);
 212                         return -EINVAL;
 213                 }
 214
 215         return 0;
 216 }
 217
 218 static int help(void) {
 219
 220         printf("%s [options]\n\n"
 221                "  -h --help               Show this help\n"
 222                "     --default=UNIT       Set default unit\n"
 223                "     --log-level=LEVEL    Set log level\n"
 224                "     --log-target=TARGET  Set log target (console, syslog, kmsg)\n"
 225                "     --running-as=AS      Set running as (init, system, session)\n"
 226                "     --test               Determine startup sequence, dump it and exit\n",
 227                __progname);
 228
 229         return 0;
 230 }
 231
 232 int main(int argc, char *argv[]) {
 233         Manager *m = NULL;
 234         Unit *target = NULL;
 235         Job *job = NULL;
 236         int r, retval = 1;
 237
 238         if (getpid() == 1)
 239                 running_as = MANAGER_INIT;
 240         else if (getuid() == 0)
 241                 running_as = MANAGER_SYSTEM;
 242         else
 243                 running_as = MANAGER_SESSION;
 244
 245         if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0)
 246                 goto finish;
 247
 248         /* Mount /proc, /sys and friends, so that /proc/cmdline and
 249          * /proc/$PID/fd is available. */
 250         if (mount_setup() < 0)
 251                 goto finish;
 252
 253         /* Reset all signal handlers. */
 254         assert_se(reset_all_signal_handlers() == 0);
 255
 256         /* Close all open files */
 257         assert_se(close_all_fds(NULL, 0) == 0);
 258
 259         if (running_as != MANAGER_SESSION)
 260                 if (parse_proc_cmdline() < 0)
 261                         goto finish;
 262
 263         log_parse_environment();
 264
 265         if (parse_argv(argc, argv) < 0)
 266                 goto finish;
 267
 268         if (action == ACTION_HELP) {
 269                 retval = help();
 270                 goto finish;
 271         }
 272
 273         assert_se(action == ACTION_RUN || action == ACTION_TEST);
 274
 275         /* Set up PATH unless it is already set */
 276         setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", false);
 277
 278         /* Move out of the way, so that we won't block unmounts */
 279         assert_se(chdir("/")  == 0);
 280
 281         /* Become a session leader if we aren't one yet. */
 282         setsid();
 283
 284         /* Disable the umask logic */
 285         umask(0);
 286
 287         /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */
 288         dbus_connection_set_change_sigpipe(FALSE);
 289
 290         /* Open the logging devices, if possible and necessary*/
 291         log_open_syslog();
 292         log_open_kmsg();
 293
 294         log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
 295
 296         if ((r = manager_new(running_as, &m)) < 0) {
 297                 log_error("Failed to allocate manager object: %s", strerror(-r));
 298                 goto finish;
 299         }
 300
 301         if ((r = manager_coldplug(m)) < 0) {
 302                 log_error("Failed to retrieve coldplug information: %s", strerror(-r));
 303                 goto finish;
 304         }
 305
 306         log_debug("Activating default unit: %s", default_unit);
 307
 308         if ((r = manager_load_unit(m, default_unit, &target)) < 0) {
 309                 log_error("Failed to load default target: %s", strerror(-r));
 310                 goto finish;
 311         }
 312
 313         if (action == ACTION_TEST) {
 314                 printf("→ By units:\n");
 315                 manager_dump_units(m, stdout, "\t");
 316         }
 317
 318         if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, false, &job)) < 0) {
 319                 log_error("Failed to start default target: %s", strerror(-r));
 320                 goto finish;
 321         }
 322
 323         if (action == ACTION_TEST) {
 324                 printf("→ By jobs:\n");
 325                 manager_dump_jobs(m, stdout, "\t");
 326
 327                 if (getpid() == 1)
 328                         pause();
 329
 330                 retval = 0;
 331                 goto finish;
 332         }
 333
 334         if ((r = manager_loop(m)) < 0) {
 335                 log_error("Failed to run mainloop: %s", strerror(-r));
 336                 goto finish;
 337         }
 338
 339         retval = 0;
 340
 341         log_debug("Exit.");
 342
 343 finish:
 344         if (m)
 345                 manager_free(m);
 346
 347         free(default_unit);
 348
 349         dbus_shutdown();
 350
 351         return retval;
 352 }