src/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 #include <fcntl.h>
  34
  35 #include "manager.h"
  36 #include "log.h"
  37 #include "mount-setup.h"
  38 #include "hostname-setup.h"
  39 #include "loopback-setup.h"
  40 #include "kmod-setup.h"
  41 #include "load-fragment.h"
  42 #include "fdset.h"
  43
  44 static enum {
  45         ACTION_RUN,
  46         ACTION_HELP,
  47         ACTION_TEST,
  48         ACTION_DUMP_CONFIGURATION_ITEMS,
  49         ACTION_DONE
  50 } action = ACTION_RUN;
  51
  52 static char *default_unit = NULL;
  53 static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID;
  54
  55 static bool dump_core = true;
  56 static bool crash_shell = false;
  57 static int crash_chvt = -1;
  58 static bool confirm_spawn = false;
  59 static FILE* serialization = NULL;
  60
  61 _noreturn_ static void freeze(void) {
  62         for (;;)
  63                 pause();
  64 }
  65
  66 static void nop_handler(int sig) {
  67 }
  68
  69 _noreturn_ static void crash(int sig) {
  70
  71         if (!dump_core)
  72                 log_error("Caught <%s>, not dumping core.", strsignal(sig));
  73         else {
  74                 struct sigaction sa;
  75                 pid_t pid;
  76
  77                 /* We want to wait for the core process, hence let's enable SIGCHLD */
  78                 zero(sa);
  79                 sa.sa_handler = nop_handler;
  80                 sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
  81                 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
  82
  83                 if ((pid = fork()) < 0)
  84                         log_error("Caught <%s>, cannot fork for core dump: %s", strsignal(sig), strerror(errno));
  85
  86                 else if (pid == 0) {
  87                         struct rlimit rl;
  88
  89                         /* Enable default signal handler for core dump */
  90                         zero(sa);
  91                         sa.sa_handler = SIG_DFL;
  92                         assert_se(sigaction(sig, &sa, NULL) == 0);
  93
  94                         /* Don't limit the core dump size */
  95                         zero(rl);
  96                         rl.rlim_cur = RLIM_INFINITY;
  97                         rl.rlim_max = RLIM_INFINITY;
  98                         setrlimit(RLIMIT_CORE, &rl);
  99
 100                         /* Just to be sure... */
 101                         assert_se(chdir("/") == 0);
 102
 103                         /* Raise the signal again */
 104                         raise(sig);
 105
 106                         assert_not_reached("We shouldn't be here...");
 107                         _exit(1);
 108
 109                 } else {
 110                         int status, r;
 111
 112                         /* Order things nicely. */
 113                         if ((r = waitpid(pid, &status, 0)) < 0)
 114                                 log_error("Caught <%s>, waitpid() failed: %s", strsignal(sig), strerror(errno));
 115                         else if (!WCOREDUMP(status))
 116                                 log_error("Caught <%s>, core dump failed.", strsignal(sig));
 117                         else
 118                                 log_error("Caught <%s>, dumped core as pid %llu.", strsignal(sig), (unsigned long long) pid);
 119                 }
 120         }
 121
 122         if (crash_chvt)
 123                 chvt(crash_chvt);
 124
 125         if (crash_shell) {
 126                 struct sigaction sa;
 127                 pid_t pid;
 128
 129                 log_info("Executing crash shell in 10s...");
 130                 sleep(10);
 131
 132                 /* Let the kernel reap children for us */
 133                 zero(sa);
 134                 sa.sa_handler = SIG_IGN;
 135                 sa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT|SA_RESTART;
 136                 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 137
 138                 if ((pid = fork()) < 0)
 139                         log_error("Failed to fork off crash shell: %s", strerror(errno));
 140                 else if (pid == 0) {
 141                         int fd, r;
 142
 143                         if ((fd = acquire_terminal("/dev/console", false, true, true)) < 0)
 144                                 log_error("Failed to acquire terminal: %s", strerror(-fd));
 145                         else if ((r = make_stdio(fd)) < 0)
 146                                 log_error("Failed to duplicate terminal fd: %s", strerror(-r));
 147
 148                         execl("/bin/sh", "/bin/sh", NULL);
 149
 150                         log_error("execl() failed: %s", strerror(errno));
 151                         _exit(1);
 152                 }
 153
 154                 log_info("Successfully spawned crash shall as pid %llu.", (unsigned long long) pid);
 155         }
 156
 157         log_info("Freezing execution.");
 158         freeze();
 159 }
 160
 161 static void install_crash_handler(void) {
 162         struct sigaction sa;
 163
 164         zero(sa);
 165
 166         sa.sa_handler = crash;
 167         sa.sa_flags = SA_NODEFER;
 168
 169         sigaction_many(&sa, SIGNALS_CRASH_HANDLER, -1);
 170 }
 171
 172 static int make_null_stdio(void) {
 173         int null_fd, r;
 174
 175         if ((null_fd = open("/dev/null", O_RDWR|O_NOCTTY)) < 0) {
 176                 log_error("Failed to open /dev/null: %m");
 177                 return -errno;
 178         }
 179
 180         if ((r = make_stdio(null_fd)) < 0)
 181                 log_warning("Failed to dup2() device: %s", strerror(-r));
 182
 183         return r;
 184 }
 185
 186 static int console_setup(bool do_reset) {
 187         int tty_fd, r;
 188
 189         /* If we are init, we connect stdin/stdout/stderr to /dev/null
 190          * and make sure we don't have a controlling tty. */
 191
 192         release_terminal();
 193
 194         if (!do_reset)
 195                 return 0;
 196
 197         if ((tty_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
 198                 log_error("Failed to open /dev/console: %s", strerror(-tty_fd));
 199                 return -tty_fd;
 200         }
 201
 202         if ((r = reset_terminal(tty_fd)) < 0)
 203                 log_error("Failed to reset /dev/console: %s", strerror(-r));
 204
 205         close_nointr_nofail(tty_fd);
 206         return r;
 207 }
 208
 209 static int set_default_unit(const char *u) {
 210         char *c;
 211
 212         assert(u);
 213
 214         if (!(c = strdup(u)))
 215                 return -ENOMEM;
 216
 217         free(default_unit);
 218         default_unit = c;
 219         return 0;
 220 }
 221
 222 static int parse_proc_cmdline_word(const char *word) {
 223
 224         static const char * const rlmap[] = {
 225                 "single", SPECIAL_RUNLEVEL1_TARGET,
 226                 "-s",     SPECIAL_RUNLEVEL1_TARGET,
 227                 "s",      SPECIAL_RUNLEVEL1_TARGET,
 228                 "S",      SPECIAL_RUNLEVEL1_TARGET,
 229                 "1",      SPECIAL_RUNLEVEL1_TARGET,
 230                 "2",      SPECIAL_RUNLEVEL2_TARGET,
 231                 "3",      SPECIAL_RUNLEVEL3_TARGET,
 232                 "4",      SPECIAL_RUNLEVEL4_TARGET,
 233                 "5",      SPECIAL_RUNLEVEL5_TARGET
 234         };
 235
 236         if (startswith(word, "systemd.unit="))
 237                 return set_default_unit(word + 13);
 238
 239         else if (startswith(word, "systemd.log_target=")) {
 240
 241                 if (log_set_target_from_string(word + 19) < 0)
 242                         log_warning("Failed to parse log target %s. Ignoring.", word + 19);
 243
 244         } else if (startswith(word, "systemd.log_level=")) {
 245
 246                 if (log_set_max_level_from_string(word + 18) < 0)
 247                         log_warning("Failed to parse log level %s. Ignoring.", word + 18);
 248
 249         } else if (startswith(word, "systemd.log_color=")) {
 250
 251                 if (log_show_color_from_string(word + 18) < 0)
 252                         log_warning("Failed to parse log color setting %s. Ignoring.", word + 18);
 253
 254         } else if (startswith(word, "systemd.log_location=")) {
 255
 256                 if (log_show_location_from_string(word + 21) < 0)
 257                         log_warning("Failed to parse log location setting %s. Ignoring.", word + 21);
 258
 259         } else if (startswith(word, "systemd.dump_core=")) {
 260                 int r;
 261
 262                 if ((r = parse_boolean(word + 18)) < 0)
 263                         log_warning("Failed to parse dump core switch %s, Ignoring.", word + 18);
 264                 else
 265                         dump_core = r;
 266
 267         } else if (startswith(word, "systemd.crash_shell=")) {
 268                 int r;
 269
 270                 if ((r = parse_boolean(word + 20)) < 0)
 271                         log_warning("Failed to parse crash shell switch %s, Ignoring.", word + 20);
 272                 else
 273                         crash_shell = r;
 274
 275
 276         } else if (startswith(word, "systemd.confirm_spawn=")) {
 277                 int r;
 278
 279                 if ((r = parse_boolean(word + 22)) < 0)
 280                         log_warning("Failed to parse confirm spawn switch %s, Ignoring.", word + 22);
 281                 else
 282                         confirm_spawn = r;
 283
 284         } else if (startswith(word, "systemd.crash_chvt=")) {
 285                 int k;
 286
 287                 if (safe_atoi(word + 19, &k) < 0)
 288                         log_warning("Failed to parse crash chvt switch %s, Ignoring.", word + 19);
 289                 else
 290                         crash_chvt = k;
 291
 292         } else if (startswith(word, "systemd.")) {
 293
 294                 log_warning("Unknown kernel switch %s. Ignoring.", word);
 295
 296                 log_info("Supported kernel switches:\n"
 297                          "systemd.unit=UNIT                        Default unit to start\n"
 298                          "systemd.log_target=console|kmsg|syslog|  Log target\n"
 299                          "                   syslog-org-kmsg|null\n"
 300                          "systemd.log_level=LEVEL                  Log level\n"
 301                          "systemd.log_color=0|1                    Highlight important log messages\n"
 302                          "systemd.log_location=0|1                 Include code location in log messages\n"
 303                          "systemd.dump_core=0|1                    Dump core on crash\n"
 304                          "systemd.crash_shell=0|1                  On crash run shell\n"
 305                          "systemd.crash_chvt=N                     Change to VT #N on crash\n"
 306                          "systemd.confirm_spawn=0|1                Confirm every process spawn");
 307
 308         } else {
 309                 unsigned i;
 310
 311                 /* SysV compatibility */
 312                 for (i = 0; i < ELEMENTSOF(rlmap); i += 2)
 313                         if (streq(word, rlmap[i]))
 314                                 return set_default_unit(rlmap[i+1]);
 315         }
 316
 317         return 0;
 318 }
 319
 320 static int parse_proc_cmdline(void) {
 321         char *line;
 322         int r;
 323         char *w;
 324         size_t l;
 325         char *state;
 326
 327         if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) {
 328                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno));
 329                 return 0;
 330         }
 331
 332         FOREACH_WORD_QUOTED(w, l, line, state) {
 333                 char *word;
 334
 335                 if (!(word = strndup(w, l))) {
 336                         r = -ENOMEM;
 337                         goto finish;
 338                 }
 339
 340                 r = parse_proc_cmdline_word(word);
 341                 free(word);
 342
 343                 if (r < 0)
 344                         goto finish;
 345         }
 346
 347         r = 0;
 348
 349 finish:
 350         free(line);
 351         return r;
 352 }
 353
 354 static int parse_argv(int argc, char *argv[]) {
 355
 356         enum {
 357                 ARG_LOG_LEVEL = 0x100,
 358                 ARG_LOG_TARGET,
 359                 ARG_LOG_COLOR,
 360                 ARG_LOG_LOCATION,
 361                 ARG_UNIT,
 362                 ARG_RUNNING_AS,
 363                 ARG_TEST,
 364                 ARG_DUMP_CONFIGURATION_ITEMS,
 365                 ARG_CONFIRM_SPAWN,
 366                 ARG_DESERIALIZE,
 367                 ARG_INTROSPECT
 368         };
 369
 370         static const struct option options[] = {
 371                 { "log-level",                required_argument, NULL, ARG_LOG_LEVEL                },
 372                 { "log-target",               required_argument, NULL, ARG_LOG_TARGET               },
 373                 { "log-color",                optional_argument, NULL, ARG_LOG_COLOR                },
 374                 { "log-location",             optional_argument, NULL, ARG_LOG_LOCATION             },
 375                 { "unit",                     required_argument, NULL, ARG_UNIT                     },
 376                 { "running-as",               required_argument, NULL, ARG_RUNNING_AS               },
 377                 { "test",                     no_argument,       NULL, ARG_TEST                     },
 378                 { "help",                     no_argument,       NULL, 'h'                          },
 379                 { "dump-configuration-items", no_argument,       NULL, ARG_DUMP_CONFIGURATION_ITEMS },
 380                 { "confirm-spawn",            no_argument,       NULL, ARG_CONFIRM_SPAWN            },
 381                 { "deserialize",              required_argument, NULL, ARG_DESERIALIZE              },
 382                 { "introspect",               optional_argument, NULL, ARG_INTROSPECT               },
 383                 { NULL,                       0,                 NULL, 0                            }
 384         };
 385
 386         int c, r;
 387
 388         assert(argc >= 1);
 389         assert(argv);
 390
 391         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
 392
 393                 switch (c) {
 394
 395                 case ARG_LOG_LEVEL:
 396                         if ((r = log_set_max_level_from_string(optarg)) < 0) {
 397                                 log_error("Failed to parse log level %s.", optarg);
 398                                 return r;
 399                         }
 400
 401                         break;
 402
 403                 case ARG_LOG_TARGET:
 404
 405                         if ((r = log_set_target_from_string(optarg)) < 0) {
 406                                 log_error("Failed to parse log target %s.", optarg);
 407                                 return r;
 408                         }
 409
 410                         break;
 411
 412                 case ARG_LOG_COLOR:
 413
 414                         if ((r = log_show_color_from_string(optarg)) < 0) {
 415                                 log_error("Failed to parse log color setting %s.", optarg);
 416                                 return r;
 417                         }
 418
 419                         break;
 420
 421                 case ARG_LOG_LOCATION:
 422
 423                         if ((r = log_show_location_from_string(optarg)) < 0) {
 424                                 log_error("Failed to parse log location setting %s.", optarg);
 425                                 return r;
 426                         }
 427
 428                         break;
 429
 430                 case ARG_UNIT:
 431
 432                         if ((r = set_default_unit(optarg)) < 0) {
 433                                 log_error("Failed to set default unit %s: %s", optarg, strerror(-r));
 434                                 return r;
 435                         }
 436
 437                         break;
 438
 439                 case ARG_RUNNING_AS: {
 440                         ManagerRunningAs as;
 441
 442                         if ((as = manager_running_as_from_string(optarg)) < 0) {
 443                                 log_error("Failed to parse running as value %s", optarg);
 444                                 return -EINVAL;
 445                         }
 446
 447                         running_as = as;
 448                         break;
 449                 }
 450
 451                 case ARG_TEST:
 452                         action = ACTION_TEST;
 453                         break;
 454
 455                 case ARG_DUMP_CONFIGURATION_ITEMS:
 456                         action = ACTION_DUMP_CONFIGURATION_ITEMS;
 457                         break;
 458
 459                 case ARG_CONFIRM_SPAWN:
 460                         confirm_spawn = true;
 461                         break;
 462
 463                 case ARG_DESERIALIZE: {
 464                         int fd;
 465                         FILE *f;
 466
 467                         if ((r = safe_atoi(optarg, &fd)) < 0 || fd < 0) {
 468                                 log_error("Failed to parse deserialize option %s.", optarg);
 469                                 return r;
 470                         }
 471
 472                         if (!(f = fdopen(fd, "r"))) {
 473                                 log_error("Failed to open serialization fd: %m");
 474                                 return r;
 475                         }
 476
 477                         if (serialization)
 478                                 fclose(serialization);
 479
 480                         serialization = f;
 481
 482                         break;
 483                 }
 484
 485                 case ARG_INTROSPECT: {
 486                         const char * const * i = NULL;
 487
 488                         for (i = bus_interface_table; *i; i += 2)
 489                                 if (!optarg || streq(i[0], optarg)) {
 490                                         fputs(DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
 491                                               "<node>\n", stdout);
 492                                         fputs(i[1], stdout);
 493                                         fputs("</node>\n", stdout);
 494
 495                                         if (optarg)
 496                                                 break;
 497                                 }
 498
 499                         if (!i[0] && optarg)
 500                                 log_error("Unknown interface %s.", optarg);
 501
 502                         action = ACTION_DONE;
 503                         break;
 504                 }
 505
 506                 case 'h':
 507                         action = ACTION_HELP;
 508                         break;
 509
 510                 case '?':
 511                         return -EINVAL;
 512
 513                 default:
 514                         log_error("Unknown option code %c", c);
 515                         return -EINVAL;
 516                 }
 517
 518         /* PID 1 will get the kernel arguments as parameters, which we
 519          * ignore and unconditionally read from
 520          * /proc/cmdline. However, we need to ignore those arguments
 521          * here. */
 522         if (running_as != MANAGER_INIT && optind < argc) {
 523                 log_error("Excess arguments.");
 524                 return -EINVAL;
 525         }
 526
 527         return 0;
 528 }
 529
 530 static int help(void) {
 531
 532         printf("%s [options]\n\n"
 533                "Starts up and maintains the system or a session.\n\n"
 534                "  -h --help                      Show this help\n"
 535                "     --unit=UNIT                 Set default unit\n"
 536                "     --running-as=AS             Set running as (init, system, session)\n"
 537                "     --test                      Determine startup sequence, dump it and exit\n"
 538                "     --dump-configuration-items  Dump understood unit configuration items\n"
 539                "     --confirm-spawn             Ask for confirmation when spawning processes\n"
 540                "     --introspect[=INTERFACE]    Extract D-Bus interface data\n"
 541                "     --log-level=LEVEL           Set log level\n"
 542                "     --log-target=TARGET         Set log target (console, syslog, kmsg, syslog-or-kmsg, null)\n"
 543                "     --log-color[=0|1]           Highlight import log messages\n"
 544                "     --log-location[=0|1]        Include code location in log messages\n",
 545                program_invocation_short_name);
 546
 547         return 0;
 548 }
 549
 550 static int prepare_reexecute(Manager *m, FILE **_f, FDSet **_fds) {
 551         FILE *f = NULL;
 552         FDSet *fds = NULL;
 553         int r;
 554
 555         assert(m);
 556         assert(_f);
 557         assert(_fds);
 558
 559         if ((r = manager_open_serialization(&f)) < 0) {
 560                 log_error("Failed to create serialization faile: %s", strerror(-r));
 561                 goto fail;
 562         }
 563
 564         if (!(fds = fdset_new())) {
 565                 r = -ENOMEM;
 566                 log_error("Failed to allocate fd set: %s", strerror(-r));
 567                 goto fail;
 568         }
 569
 570         if ((r = manager_serialize(m, f, fds)) < 0) {
 571                 log_error("Failed to serialize state: %s", strerror(-r));
 572                 goto fail;
 573         }
 574
 575         if (fseeko(f, 0, SEEK_SET) < 0) {
 576                 log_error("Failed to rewind serialization fd: %m");
 577                 goto fail;
 578         }
 579
 580         if ((r = fd_cloexec(fileno(f), false)) < 0) {
 581                 log_error("Failed to disable O_CLOEXEC for serialization: %s", strerror(-r));
 582                 goto fail;
 583         }
 584
 585         if ((r = fdset_cloexec(fds, false)) < 0) {
 586                 log_error("Failed to disable O_CLOEXEC for serialization fds: %s", strerror(-r));
 587                 goto fail;
 588         }
 589
 590         *_f = f;
 591         *_fds = fds;
 592
 593         return 0;
 594
 595 fail:
 596         fdset_free(fds);
 597
 598         if (f)
 599                 fclose(f);
 600
 601         return r;
 602 }
 603
 604 int main(int argc, char *argv[]) {
 605         Manager *m = NULL;
 606         Unit *target = NULL;
 607         Job *job = NULL;
 608         int r, retval = 1;
 609         FDSet *fds = NULL;
 610         bool reexecute = false;
 611
 612         log_show_color(true);
 613         log_show_location(false);
 614         log_set_max_level(LOG_DEBUG);
 615
 616         if (getpid() == 1) {
 617                 running_as = MANAGER_INIT;
 618                 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 619         } else {
 620                 running_as = MANAGER_SESSION;
 621                 log_set_target(LOG_TARGET_CONSOLE);
 622         }
 623
 624         if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0)
 625                 goto finish;
 626
 627         /* Mount /proc, /sys and friends, so that /proc/cmdline and
 628          * /proc/$PID/fd is available. */
 629         if (geteuid() == 0)
 630                 if (mount_setup() < 0)
 631                         goto finish;
 632
 633         /* Reset all signal handlers. */
 634         assert_se(reset_all_signal_handlers() == 0);
 635
 636         /* If we are init, we can block sigkill. Yay. */
 637         ignore_signals(SIGNALS_IGNORE, -1);
 638
 639         if (running_as != MANAGER_SESSION)
 640                 if (parse_proc_cmdline() < 0)
 641                         goto finish;
 642
 643         log_parse_environment();
 644
 645         if (parse_argv(argc, argv) < 0)
 646                 goto finish;
 647
 648         if (action == ACTION_HELP) {
 649                 retval = help();
 650                 goto finish;
 651         } else if (action == ACTION_DUMP_CONFIGURATION_ITEMS) {
 652                 unit_dump_config_items(stdout);
 653                 retval = 0;
 654                 goto finish;
 655         } else if (action == ACTION_DONE) {
 656                 retval = 0;
 657                 goto finish;
 658         }
 659
 660         assert_se(action == ACTION_RUN || action == ACTION_TEST);
 661
 662         /* Remember open file descriptors for later deserialization */
 663         if (serialization) {
 664                 if ((r = fdset_new_fill(&fds)) < 0) {
 665                         log_error("Failed to allocate fd set: %s", strerror(-r));
 666                         goto finish;
 667                 }
 668
 669                 assert_se(fdset_remove(fds, fileno(serialization)) >= 0);
 670         } else
 671                 close_all_fds(NULL, 0);
 672
 673         /* Set up PATH unless it is already set */
 674         setenv("PATH",
 675                "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
 676                running_as == MANAGER_INIT);
 677
 678         /* Move out of the way, so that we won't block unmounts */
 679         assert_se(chdir("/")  == 0);
 680
 681         if (running_as != MANAGER_SESSION) {
 682                 /* Become a session leader if we aren't one yet. */
 683                 setsid();
 684
 685                 /* Disable the umask logic */
 686                 umask(0);
 687         }
 688
 689         /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */
 690         dbus_connection_set_change_sigpipe(FALSE);
 691
 692         /* Reset the console, but only if this is really init and we
 693          * are freshly booted */
 694         if (running_as != MANAGER_SESSION && action == ACTION_RUN) {
 695                 console_setup(getpid() == 1 && !serialization);
 696                 make_null_stdio();
 697         }
 698
 699         /* Open the logging devices, if possible and necessary */
 700         log_open();
 701
 702         /* Make sure we leave a core dump without panicing the
 703          * kernel. */
 704         if (getpid() == 1)
 705                 install_crash_handler();
 706
 707         log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
 708
 709         if (running_as == MANAGER_INIT) {
 710                 kmod_setup();
 711                 hostname_setup();
 712                 loopback_setup();
 713         }
 714
 715         if ((r = manager_new(running_as, confirm_spawn, &m)) < 0) {
 716                 log_error("Failed to allocate manager object: %s", strerror(-r));
 717                 goto finish;
 718         }
 719
 720         if ((r = manager_startup(m, serialization, fds)) < 0)
 721                 log_error("Failed to fully start up daemon: %s", strerror(-r));
 722
 723         if (fds) {
 724                 /* This will close all file descriptors that were opened, but
 725                  * not claimed by any unit. */
 726
 727                 fdset_free(fds);
 728                 fds = NULL;
 729         }
 730
 731         if (serialization) {
 732                 fclose(serialization);
 733                 serialization = NULL;
 734         } else {
 735                 log_debug("Activating default unit: %s", default_unit);
 736
 737                 if ((r = manager_load_unit(m, default_unit, NULL, &target)) < 0) {
 738                         log_error("Failed to load default target: %s", strerror(-r));
 739
 740                         log_info("Trying to load rescue target...");
 741                         if ((r = manager_load_unit(m, SPECIAL_RESCUE_TARGET, NULL, &target)) < 0) {
 742                                 log_error("Failed to load rescue target: %s", strerror(-r));
 743                                 goto finish;
 744                         }
 745                 }
 746
 747                 if (action == ACTION_TEST) {
 748                         printf("-> By units:\n");
 749                         manager_dump_units(m, stdout, "\t");
 750                 }
 751
 752                 if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, false, &job)) < 0) {
 753                         log_error("Failed to start default target: %s", strerror(-r));
 754                         goto finish;
 755                 }
 756
 757                 if (action == ACTION_TEST) {
 758                         printf("-> By jobs:\n");
 759                         manager_dump_jobs(m, stdout, "\t");
 760                         retval = 0;
 761                         goto finish;
 762                 }
 763         }
 764
 765         for (;;) {
 766                 if ((r = manager_loop(m)) < 0) {
 767                         log_error("Failed to run mainloop: %s", strerror(-r));
 768                         goto finish;
 769                 }
 770
 771                 switch (m->exit_code) {
 772
 773                 case MANAGER_EXIT:
 774                         retval = 0;
 775                         log_debug("Exit.");
 776                         goto finish;
 777
 778                 case MANAGER_RELOAD:
 779                         if ((r = manager_reload(m)) < 0)
 780                                 log_error("Failed to reload: %s", strerror(-r));
 781                         break;
 782
 783                 case MANAGER_REEXECUTE:
 784                         if (prepare_reexecute(m, &serialization, &fds) < 0)
 785                                 goto finish;
 786
 787                         reexecute = true;
 788                         log_debug("Reexecuting.");
 789                         goto finish;
 790
 791                 default:
 792                         assert_not_reached("Unknown exit code.");
 793                 }
 794         }
 795
 796 finish:
 797         if (m)
 798                 manager_free(m);
 799
 800         free(default_unit);
 801
 802         dbus_shutdown();
 803
 804         if (reexecute) {
 805                 const char *args[11];
 806                 unsigned i = 0;
 807                 char sfd[16];
 808
 809                 assert(serialization);
 810                 assert(fds);
 811
 812                 args[i++] = SYSTEMD_BINARY_PATH;
 813
 814                 args[i++] = "--log-level";
 815                 args[i++] = log_level_to_string(log_get_max_level());
 816
 817                 args[i++] = "--log-target";
 818                 args[i++] = log_target_to_string(log_get_target());
 819
 820                 args[i++] = "--running-as";
 821                 args[i++] = manager_running_as_to_string(running_as);
 822
 823                 snprintf(sfd, sizeof(sfd), "%i", fileno(serialization));
 824                 char_array_0(sfd);
 825
 826                 args[i++] = "--deserialize";
 827                 args[i++] = sfd;
 828
 829                 if (confirm_spawn)
 830                         args[i++] = "--confirm-spawn";
 831
 832                 args[i++] = NULL;
 833
 834                 assert(i <= ELEMENTSOF(args));
 835
 836                 execv(args[0], (char* const*) args);
 837
 838                 log_error("Failed to reexecute: %m");
 839         }
 840
 841         if (serialization)
 842                 fclose(serialization);
 843
 844         if (fds)
 845                 fdset_free(fds);
 846
 847         if (getpid() == 1)
 848                 freeze();
 849
 850         return retval;
 851 }