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 #include <signal.h>
  32 #include <sys/wait.h>
  33
  34 #include "manager.h"
  35 #include "log.h"
  36 #include "mount-setup.h"
  37 #include "hostname-setup.h"
  38 #include "load-fragment.h"
  39
  40 static enum {
  41         ACTION_RUN,
  42         ACTION_HELP,
  43         ACTION_TEST,
  44         ACTION_DUMP_CONFIGURATION_ITEMS
  45 } action = ACTION_RUN;
  46
  47 static char *default_unit = NULL;
  48 static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID;
  49
  50 static bool dump_core = true;
  51 static bool crash_shell = false;
  52 static int crash_chvt = -1;
  53
  54 _noreturn static void freeze(void) {
  55         for (;;)
  56                 pause();
  57 }
  58
  59 _noreturn static void crash(int sig) {
  60
  61         if (!dump_core)
  62                 log_error("Caught <%s>, not dumping core.", strsignal(sig));
  63         else {
  64                 pid_t pid;
  65
  66                 if ((pid = fork()) < 0)
  67                         log_error("Caught <%s>, cannot fork for core dump: %s", strsignal(sig), strerror(errno));
  68
  69                 else if (pid == 0) {
  70                         struct sigaction sa;
  71                         struct rlimit rl;
  72
  73                         /* Enable default signal handler for core dump */
  74                         zero(sa);
  75                         sa.sa_handler = SIG_DFL;
  76                         assert_se(sigaction(sig, &sa, NULL) == 0);
  77
  78                         /* Don't limit the core dump size */
  79                         zero(rl);
  80                         rl.rlim_cur = RLIM_INFINITY;
  81                         rl.rlim_max = RLIM_INFINITY;
  82                         setrlimit(RLIMIT_CORE, &rl);
  83
  84                         /* Just to be sure... */
  85                         assert_se(chdir("/") == 0);
  86
  87                         /* Raise the signal again */
  88                         raise(sig);
  89
  90                         assert_not_reached("We shouldn't be here...");
  91                         _exit(1);
  92
  93                 } else {
  94                         int status, r;
  95
  96                         /* Order things nicely. */
  97                         if ((r = waitpid(pid, &status, 0)) < 0)
  98                                 log_error("Caught <%s>, waitpid() failed: %s", strsignal(sig), strerror(errno));
  99                         else if (!WCOREDUMP(status))
 100                                 log_error("Caught <%s>, core dump failed.", strsignal(sig));
 101                         else
 102                                 log_error("Caught <%s>, dumped core as pid %llu.", strsignal(sig), (unsigned long long) pid);
 103                 }
 104         }
 105
 106         if (crash_chvt)
 107                 chvt(crash_chvt);
 108
 109         if (crash_shell) {
 110                 log_info("Executing crash shell in 10s...");
 111                 sleep(10);
 112
 113                 execl("/bin/sh", "/bin/sh", NULL);
 114                 log_error("execl() failed: %s", strerror(errno));
 115         }
 116
 117         log_info("Freezing execution.");
 118         freeze();
 119 }
 120
 121 static void install_crash_handler(void) {
 122         struct sigaction sa;
 123
 124         zero(sa);
 125
 126         sa.sa_handler = crash;
 127         sa.sa_flags = SA_NODEFER;
 128
 129         assert_se(sigaction(SIGSEGV, &sa, NULL) == 0);
 130         assert_se(sigaction(SIGILL, &sa, NULL) == 0);
 131         assert_se(sigaction(SIGFPE, &sa, NULL) == 0);
 132         assert_se(sigaction(SIGBUS, &sa, NULL) == 0);
 133         assert_se(sigaction(SIGQUIT, &sa, NULL) == 0);
 134         assert_se(sigaction(SIGABRT, &sa, NULL) == 0);
 135 }
 136
 137 static int set_default_unit(const char *u) {
 138         char *c;
 139
 140         assert(u);
 141
 142         if (!(c = strdup(u)))
 143                 return -ENOMEM;
 144
 145         free(default_unit);
 146         default_unit = c;
 147         return 0;
 148 }
 149
 150 static int parse_proc_cmdline_word(const char *word) {
 151
 152         static const char * const rlmap[] = {
 153                 "single", SPECIAL_RUNLEVEL1_TARGET,
 154                 "-s",     SPECIAL_RUNLEVEL1_TARGET,
 155                 "s",      SPECIAL_RUNLEVEL1_TARGET,
 156                 "S",      SPECIAL_RUNLEVEL1_TARGET,
 157                 "1",      SPECIAL_RUNLEVEL1_TARGET,
 158                 "2",      SPECIAL_RUNLEVEL2_TARGET,
 159                 "3",      SPECIAL_RUNLEVEL3_TARGET,
 160                 "4",      SPECIAL_RUNLEVEL4_TARGET,
 161                 "5",      SPECIAL_RUNLEVEL5_TARGET
 162         };
 163
 164         if (startswith(word, "systemd.default="))
 165                 return set_default_unit(word + 16);
 166
 167         else if (startswith(word, "systemd.log_target=")) {
 168
 169                 if (log_set_target_from_string(word + 19) < 0)
 170                         log_warning("Failed to parse log target %s. Ignoring.", word + 19);
 171
 172         } else if (startswith(word, "systemd.log_level=")) {
 173
 174                 if (log_set_max_level_from_string(word + 18) < 0)
 175                         log_warning("Failed to parse log level %s. Ignoring.", word + 18);
 176
 177         } else if (startswith(word, "systemd.dump_core=")) {
 178                 int r;
 179
 180                 if ((r = parse_boolean(word + 18)) < 0)
 181                         log_warning("Failed to parse dump core switch %s, Ignoring.", word + 18);
 182                 else
 183                         dump_core = r;
 184
 185         } else if (startswith(word, "systemd.crash_shell=")) {
 186                 int r;
 187
 188                 if ((r = parse_boolean(word + 20)) < 0)
 189                         log_warning("Failed to parse crash shell switch %s, Ignoring.", word + 20);
 190                 else
 191                         crash_shell = r;
 192
 193         } else if (startswith(word, "systemd.crash_chvt=")) {
 194                 int k;
 195
 196                 if (safe_atoi(word + 19, &k) < 0)
 197                         log_warning("Failed to parse crash chvt switch %s, Ignoring.", word + 19);
 198                 else
 199                         crash_chvt = k;
 200
 201         } else if (startswith(word, "systemd.")) {
 202
 203                 log_warning("Unknown kernel switch %s. Ignoring.", word);
 204
 205                 log_info("Supported kernel switches:");
 206                 log_info("systemd.default=UNIT                     Default unit to start");
 207                 log_info("systemd.log_target=console|kmsg|syslog   Log target");
 208                 log_info("systemd.log_level=LEVEL                  Log level");
 209                 log_info("systemd.dump_core=0|1                    Dump core on crash");
 210                 log_info("systemd.crash_shell=0|1                  On crash run shell");
 211                 log_info("systemd.crash_chvt=N                     Change to VT #N on crash");
 212
 213         } else {
 214                 unsigned i;
 215
 216                 /* SysV compatibility */
 217                 for (i = 0; i < ELEMENTSOF(rlmap); i += 2)
 218                         if (streq(word, rlmap[i]))
 219                                 return set_default_unit(rlmap[i+1]);
 220         }
 221
 222         return 0;
 223 }
 224
 225 static int parse_proc_cmdline(void) {
 226         char *line;
 227         int r;
 228         char *w;
 229         size_t l;
 230         char *state;
 231
 232         if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) {
 233                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno));
 234                 return 0;
 235         }
 236
 237         FOREACH_WORD_QUOTED(w, l, line, state) {
 238                 char *word;
 239
 240                 if (!(word = strndup(w, l))) {
 241                         r = -ENOMEM;
 242                         goto finish;
 243                 }
 244
 245                 r = parse_proc_cmdline_word(word);
 246                 free(word);
 247
 248                 if (r < 0)
 249                         goto finish;
 250         }
 251
 252         r = 0;
 253
 254 finish:
 255         free(line);
 256         return r;
 257 }
 258
 259 static int parse_argv(int argc, char *argv[]) {
 260
 261         enum {
 262                 ARG_LOG_LEVEL = 0x100,
 263                 ARG_LOG_TARGET,
 264                 ARG_DEFAULT,
 265                 ARG_RUNNING_AS,
 266                 ARG_TEST,
 267                 ARG_DUMP_CONFIGURATION_ITEMS
 268         };
 269
 270         static const struct option options[] = {
 271                 { "log-level",  required_argument, NULL, ARG_LOG_LEVEL },
 272                 { "log-target", required_argument, NULL, ARG_LOG_TARGET },
 273                 { "default",    required_argument, NULL, ARG_DEFAULT },
 274                 { "running-as", required_argument, NULL, ARG_RUNNING_AS },
 275                 { "test",       no_argument,       NULL, ARG_TEST },
 276                 { "help",       no_argument,       NULL, 'h' },
 277                 { "dump-configuration-items", no_argument, NULL, ARG_DUMP_CONFIGURATION_ITEMS },
 278                 { NULL,         0,                 NULL, 0 }
 279         };
 280
 281         int c, r;
 282
 283         assert(argc >= 1);
 284         assert(argv);
 285
 286         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
 287
 288                 switch (c) {
 289
 290                 case ARG_LOG_LEVEL:
 291                         if ((r = log_set_max_level_from_string(optarg)) < 0) {
 292                                 log_error("Failed to parse log level %s.", optarg);
 293                                 return r;
 294                         }
 295
 296                         break;
 297
 298                 case ARG_LOG_TARGET:
 299
 300                         if ((r = log_set_target_from_string(optarg)) < 0) {
 301                                 log_error("Failed to parse log target %s.", optarg);
 302                                 return r;
 303                         }
 304
 305                         break;
 306
 307                 case ARG_DEFAULT:
 308
 309                         if ((r = set_default_unit(optarg)) < 0) {
 310                                 log_error("Failed to set default unit %s: %s", optarg, strerror(-r));
 311                                 return r;
 312                         }
 313
 314                         break;
 315
 316                 case ARG_RUNNING_AS: {
 317                         ManagerRunningAs as;
 318
 319                         if ((as = manager_running_as_from_string(optarg)) < 0) {
 320                                 log_error("Failed to parse running as value %s", optarg);
 321                                 return -EINVAL;
 322                         }
 323
 324                         running_as = as;
 325                         break;
 326                 }
 327
 328                 case ARG_TEST:
 329                         action = ACTION_TEST;
 330                         break;
 331
 332                 case ARG_DUMP_CONFIGURATION_ITEMS:
 333                         action = ACTION_DUMP_CONFIGURATION_ITEMS;
 334                         break;
 335
 336                 case 'h':
 337                         action = ACTION_HELP;
 338                         break;
 339
 340                 case '?':
 341                         return -EINVAL;
 342
 343                 default:
 344                         log_error("Unknown option code %c", c);
 345                         return -EINVAL;
 346                 }
 347
 348         return 0;
 349 }
 350
 351 static int help(void) {
 352
 353         printf("%s [options]\n\n"
 354                "  -h --help                      Show this help\n"
 355                "     --default=UNIT              Set default unit\n"
 356                "     --log-level=LEVEL           Set log level\n"
 357                "     --log-target=TARGET         Set log target (console, syslog, kmsg)\n"
 358                "     --running-as=AS             Set running as (init, system, session)\n"
 359                "     --test                      Determine startup sequence, dump it and exit\n"
 360                "     --dump-configuration-items  Dump understood unit configuration items\n",
 361                __progname);
 362
 363         return 0;
 364 }
 365
 366 int main(int argc, char *argv[]) {
 367         Manager *m = NULL;
 368         Unit *target = NULL;
 369         Job *job = NULL;
 370         int r, retval = 1;
 371
 372         if (getpid() == 1)
 373                 running_as = MANAGER_INIT;
 374         else if (getuid() == 0)
 375                 running_as = MANAGER_SYSTEM;
 376         else
 377                 running_as = MANAGER_SESSION;
 378
 379         if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0)
 380                 goto finish;
 381
 382         /* Mount /proc, /sys and friends, so that /proc/cmdline and
 383          * /proc/$PID/fd is available. */
 384         if (mount_setup() < 0)
 385                 goto finish;
 386
 387         /* Reset all signal handlers. */
 388         assert_se(reset_all_signal_handlers() == 0);
 389
 390         /* If we are init, we can block sigkill. Yay. */
 391         signal(SIGKILL, SIG_IGN);
 392         signal(SIGPIPE, SIG_IGN);
 393
 394         /* Close all open files */
 395         assert_se(close_all_fds(NULL, 0) == 0);
 396
 397         if (running_as != MANAGER_SESSION)
 398                 if (parse_proc_cmdline() < 0)
 399                         goto finish;
 400
 401         log_parse_environment();
 402
 403         if (parse_argv(argc, argv) < 0)
 404                 goto finish;
 405
 406         if (action == ACTION_HELP) {
 407                 retval = help();
 408                 goto finish;
 409         } else if (action == ACTION_DUMP_CONFIGURATION_ITEMS) {
 410                 unit_dump_config_items(stdout);
 411                 retval = 0;
 412                 goto finish;
 413         }
 414
 415         assert_se(action == ACTION_RUN || action == ACTION_TEST);
 416
 417         /* Set up PATH unless it is already set */
 418         setenv("PATH",
 419                "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
 420                running_as == MANAGER_INIT);
 421
 422         /* Move out of the way, so that we won't block unmounts */
 423         assert_se(chdir("/")  == 0);
 424
 425         /* Become a session leader if we aren't one yet. */
 426         setsid();
 427
 428         /* Disable the umask logic */
 429         umask(0);
 430
 431         /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */
 432         dbus_connection_set_change_sigpipe(FALSE);
 433
 434         /* Open the logging devices, if possible and necessary */
 435         log_open_syslog();
 436         log_open_kmsg();
 437
 438         /* Make sure we leave a core dump without panicing the
 439          * kernel. */
 440         if (getpid() == 1)
 441                 install_crash_handler();
 442
 443         log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
 444
 445         if (running_as == MANAGER_INIT)
 446                 hostname_setup();
 447
 448         if ((r = manager_new(running_as, &m)) < 0) {
 449                 log_error("Failed to allocate manager object: %s", strerror(-r));
 450                 goto finish;
 451         }
 452
 453         if ((r = manager_coldplug(m)) < 0) {
 454                 log_error("Failed to retrieve coldplug information: %s", strerror(-r));
 455                 goto finish;
 456         }
 457
 458         log_debug("Activating default unit: %s", default_unit);
 459
 460         if ((r = manager_load_unit(m, default_unit, &target)) < 0) {
 461                 log_error("Failed to load default target: %s", strerror(-r));
 462
 463                 log_info("Trying to load rescue target...");
 464                 if ((r = manager_load_unit(m, SPECIAL_RESCUE_TARGET, &target)) < 0) {
 465                         log_error("Failed to load rescue target: %s", strerror(-r));
 466                         goto finish;
 467                 }
 468         }
 469
 470         if (action == ACTION_TEST) {
 471                 printf("→ By units:\n");
 472                 manager_dump_units(m, stdout, "\t");
 473         }
 474
 475         if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, false, &job)) < 0) {
 476                 log_error("Failed to start default target: %s", strerror(-r));
 477                 goto finish;
 478         }
 479
 480         if (action == ACTION_TEST) {
 481                 printf("→ By jobs:\n");
 482                 manager_dump_jobs(m, stdout, "\t");
 483
 484                 if (getpid() == 1)
 485                         pause();
 486
 487                 retval = 0;
 488                 goto finish;
 489         }
 490
 491         if ((r = manager_loop(m)) < 0) {
 492                 log_error("Failed to run mainloop: %s", strerror(-r));
 493                 goto finish;
 494         }
 495
 496         retval = 0;
 497
 498         log_debug("Exit.");
 499
 500 finish:
 501         if (m)
 502                 manager_free(m);
 503
 504         free(default_unit);
 505
 506         dbus_shutdown();
 507
 508         return retval;
 509 }