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 #include "special.h"
  44
  45 static enum {
  46         ACTION_RUN,
  47         ACTION_HELP,
  48         ACTION_TEST,
  49         ACTION_DUMP_CONFIGURATION_ITEMS,
  50         ACTION_DONE
  51 } action = ACTION_RUN;
  52
  53 static char *default_unit = NULL;
  54 static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID;
  55
  56 static bool dump_core = true;
  57 static bool crash_shell = false;
  58 static int crash_chvt = -1;
  59 static bool confirm_spawn = false;
  60 static FILE* serialization = NULL;
  61
  62 _noreturn_ static void freeze(void) {
  63         for (;;)
  64                 pause();
  65 }
  66
  67 static void nop_handler(int sig) {
  68 }
  69
  70 _noreturn_ static void crash(int sig) {
  71
  72         if (!dump_core)
  73                 log_error("Caught <%s>, not dumping core.", strsignal(sig));
  74         else {
  75                 struct sigaction sa;
  76                 pid_t pid;
  77
  78                 /* We want to wait for the core process, hence let's enable SIGCHLD */
  79                 zero(sa);
  80                 sa.sa_handler = nop_handler;
  81                 sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
  82                 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
  83
  84                 if ((pid = fork()) < 0)
  85                         log_error("Caught <%s>, cannot fork for core dump: %s", strsignal(sig), strerror(errno));
  86
  87                 else if (pid == 0) {
  88                         struct rlimit rl;
  89
  90                         /* Enable default signal handler for core dump */
  91                         zero(sa);
  92                         sa.sa_handler = SIG_DFL;
  93                         assert_se(sigaction(sig, &sa, NULL) == 0);
  94
  95                         /* Don't limit the core dump size */
  96                         zero(rl);
  97                         rl.rlim_cur = RLIM_INFINITY;
  98                         rl.rlim_max = RLIM_INFINITY;
  99                         setrlimit(RLIMIT_CORE, &rl);
 100
 101                         /* Just to be sure... */
 102                         assert_se(chdir("/") == 0);
 103
 104                         /* Raise the signal again */
 105                         raise(sig);
 106
 107                         assert_not_reached("We shouldn't be here...");
 108                         _exit(1);
 109
 110                 } else {
 111                         int status, r;
 112
 113                         /* Order things nicely. */
 114                         if ((r = waitpid(pid, &status, 0)) < 0)
 115                                 log_error("Caught <%s>, waitpid() failed: %s", strsignal(sig), strerror(errno));
 116                         else if (!WCOREDUMP(status))
 117                                 log_error("Caught <%s>, core dump failed.", strsignal(sig));
 118                         else
 119                                 log_error("Caught <%s>, dumped core as pid %lu.", strsignal(sig), (unsigned long) pid);
 120                 }
 121         }
 122
 123         if (crash_chvt)
 124                 chvt(crash_chvt);
 125
 126         if (crash_shell) {
 127                 struct sigaction sa;
 128                 pid_t pid;
 129
 130                 log_info("Executing crash shell in 10s...");
 131                 sleep(10);
 132
 133                 /* Let the kernel reap children for us */
 134                 zero(sa);
 135                 sa.sa_handler = SIG_IGN;
 136                 sa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT|SA_RESTART;
 137                 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 138
 139                 if ((pid = fork()) < 0)
 140                         log_error("Failed to fork off crash shell: %s", strerror(errno));
 141                 else if (pid == 0) {
 142                         int fd, r;
 143
 144                         if ((fd = acquire_terminal("/dev/console", false, true, true)) < 0)
 145                                 log_error("Failed to acquire terminal: %s", strerror(-fd));
 146                         else if ((r = make_stdio(fd)) < 0)
 147                                 log_error("Failed to duplicate terminal fd: %s", strerror(-r));
 148
 149                         execl("/bin/sh", "/bin/sh", NULL);
 150
 151                         log_error("execl() failed: %s", strerror(errno));
 152                         _exit(1);
 153                 }
 154
 155                 log_info("Successfully spawned crash shall as pid %lu.", (unsigned long) pid);
 156         }
 157
 158         log_info("Freezing execution.");
 159         freeze();
 160 }
 161
 162 static void install_crash_handler(void) {
 163         struct sigaction sa;
 164
 165         zero(sa);
 166
 167         sa.sa_handler = crash;
 168         sa.sa_flags = SA_NODEFER;
 169
 170         sigaction_many(&sa, SIGNALS_CRASH_HANDLER, -1);
 171 }
 172
 173 static int make_null_stdio(void) {
 174         int null_fd, r;
 175
 176         if ((null_fd = open("/dev/null", O_RDWR|O_NOCTTY)) < 0) {
 177                 log_error("Failed to open /dev/null: %m");
 178                 return -errno;
 179         }
 180
 181         if ((r = make_stdio(null_fd)) < 0)
 182                 log_warning("Failed to dup2() device: %s", strerror(-r));
 183
 184         return r;
 185 }
 186
 187 static int console_setup(bool do_reset) {
 188         int tty_fd, r;
 189
 190         /* If we are init, we connect stdin/stdout/stderr to /dev/null
 191          * and make sure we don't have a controlling tty. */
 192
 193         release_terminal();
 194
 195         if (!do_reset)
 196                 return 0;
 197
 198         if ((tty_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
 199                 log_error("Failed to open /dev/console: %s", strerror(-tty_fd));
 200                 return -tty_fd;
 201         }
 202
 203         if ((r = reset_terminal(tty_fd)) < 0)
 204                 log_error("Failed to reset /dev/console: %s", strerror(-r));
 205
 206         close_nointr_nofail(tty_fd);
 207         return r;
 208 }
 209
 210 static int set_default_unit(const char *u) {
 211         char *c;
 212
 213         assert(u);
 214
 215         if (!(c = strdup(u)))
 216                 return -ENOMEM;
 217
 218         free(default_unit);
 219         default_unit = c;
 220         return 0;
 221 }
 222
 223 static int parse_proc_cmdline_word(const char *word) {
 224
 225         static const char * const rlmap[] = {
 226                 "single", SPECIAL_RESCUE_TARGET,
 227                 "-s",     SPECIAL_RESCUE_TARGET,
 228                 "s",      SPECIAL_RESCUE_TARGET,
 229                 "S",      SPECIAL_RESCUE_TARGET,
 230                 "1",      SPECIAL_RESCUE_TARGET,
 231                 "2",      SPECIAL_RUNLEVEL2_TARGET,
 232                 "3",      SPECIAL_RUNLEVEL3_TARGET,
 233                 "4",      SPECIAL_RUNLEVEL4_TARGET,
 234                 "5",      SPECIAL_RUNLEVEL5_TARGET
 235         };
 236
 237         if (startswith(word, "systemd.unit="))
 238                 return set_default_unit(word + 13);
 239
 240         else if (startswith(word, "systemd.log_target=")) {
 241
 242                 if (log_set_target_from_string(word + 19) < 0)
 243                         log_warning("Failed to parse log target %s. Ignoring.", word + 19);
 244
 245         } else if (startswith(word, "systemd.log_level=")) {
 246
 247                 if (log_set_max_level_from_string(word + 18) < 0)
 248                         log_warning("Failed to parse log level %s. Ignoring.", word + 18);
 249
 250         } else if (startswith(word, "systemd.log_color=")) {
 251
 252                 if (log_show_color_from_string(word + 18) < 0)
 253                         log_warning("Failed to parse log color setting %s. Ignoring.", word + 18);
 254
 255         } else if (startswith(word, "systemd.log_location=")) {
 256
 257                 if (log_show_location_from_string(word + 21) < 0)
 258                         log_warning("Failed to parse log location setting %s. Ignoring.", word + 21);
 259
 260         } else if (startswith(word, "systemd.dump_core=")) {
 261                 int r;
 262
 263                 if ((r = parse_boolean(word + 18)) < 0)
 264                         log_warning("Failed to parse dump core switch %s, Ignoring.", word + 18);
 265                 else
 266                         dump_core = r;
 267
 268         } else if (startswith(word, "systemd.crash_shell=")) {
 269                 int r;
 270
 271                 if ((r = parse_boolean(word + 20)) < 0)
 272                         log_warning("Failed to parse crash shell switch %s, Ignoring.", word + 20);
 273                 else
 274                         crash_shell = r;
 275
 276
 277         } else if (startswith(word, "systemd.confirm_spawn=")) {
 278                 int r;
 279
 280                 if ((r = parse_boolean(word + 22)) < 0)
 281                         log_warning("Failed to parse confirm spawn switch %s, Ignoring.", word + 22);
 282                 else
 283                         confirm_spawn = r;
 284
 285         } else if (startswith(word, "systemd.crash_chvt=")) {
 286                 int k;
 287
 288                 if (safe_atoi(word + 19, &k) < 0)
 289                         log_warning("Failed to parse crash chvt switch %s, Ignoring.", word + 19);
 290                 else
 291                         crash_chvt = k;
 292
 293         } else if (startswith(word, "systemd.")) {
 294
 295                 log_warning("Unknown kernel switch %s. Ignoring.", word);
 296
 297                 log_info("Supported kernel switches:\n"
 298                          "systemd.unit=UNIT                        Default unit to start\n"
 299                          "systemd.log_target=console|kmsg|syslog|  Log target\n"
 300                          "                   syslog-org-kmsg|null\n"
 301                          "systemd.log_level=LEVEL                  Log level\n"
 302                          "systemd.log_color=0|1                    Highlight important log messages\n"
 303                          "systemd.log_location=0|1                 Include code location in log messages\n"
 304                          "systemd.dump_core=0|1                    Dump core on crash\n"
 305                          "systemd.crash_shell=0|1                  On crash run shell\n"
 306                          "systemd.crash_chvt=N                     Change to VT #N on crash\n"
 307                          "systemd.confirm_spawn=0|1                Confirm every process spawn");
 308
 309         } else {
 310                 unsigned i;
 311
 312                 /* SysV compatibility */
 313                 for (i = 0; i < ELEMENTSOF(rlmap); i += 2)
 314                         if (streq(word, rlmap[i]))
 315                                 return set_default_unit(rlmap[i+1]);
 316         }
 317
 318         return 0;
 319 }
 320
 321 static int parse_proc_cmdline(void) {
 322         char *line;
 323         int r;
 324         char *w;
 325         size_t l;
 326         char *state;
 327
 328         if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) {
 329                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno));
 330                 return 0;
 331         }
 332
 333         FOREACH_WORD_QUOTED(w, l, line, state) {
 334                 char *word;
 335
 336                 if (!(word = strndup(w, l))) {
 337                         r = -ENOMEM;
 338                         goto finish;
 339                 }
 340
 341                 r = parse_proc_cmdline_word(word);
 342                 free(word);
 343
 344                 if (r < 0)
 345                         goto finish;
 346         }
 347
 348         r = 0;
 349
 350 finish:
 351         free(line);
 352         return r;
 353 }
 354
 355 static int parse_argv(int argc, char *argv[]) {
 356
 357         enum {
 358                 ARG_LOG_LEVEL = 0x100,
 359                 ARG_LOG_TARGET,
 360                 ARG_LOG_COLOR,
 361                 ARG_LOG_LOCATION,
 362                 ARG_UNIT,
 363                 ARG_RUNNING_AS,
 364                 ARG_TEST,
 365                 ARG_DUMP_CONFIGURATION_ITEMS,
 366                 ARG_CONFIRM_SPAWN,
 367                 ARG_DESERIALIZE,
 368                 ARG_INTROSPECT
 369         };
 370
 371         static const struct option options[] = {
 372                 { "log-level",                required_argument, NULL, ARG_LOG_LEVEL                },
 373                 { "log-target",               required_argument, NULL, ARG_LOG_TARGET               },
 374                 { "log-color",                optional_argument, NULL, ARG_LOG_COLOR                },
 375                 { "log-location",             optional_argument, NULL, ARG_LOG_LOCATION             },
 376                 { "unit",                     required_argument, NULL, ARG_UNIT                     },
 377                 { "running-as",               required_argument, NULL, ARG_RUNNING_AS               },
 378                 { "test",                     no_argument,       NULL, ARG_TEST                     },
 379                 { "help",                     no_argument,       NULL, 'h'                          },
 380                 { "dump-configuration-items", no_argument,       NULL, ARG_DUMP_CONFIGURATION_ITEMS },
 381                 { "confirm-spawn",            no_argument,       NULL, ARG_CONFIRM_SPAWN            },
 382                 { "deserialize",              required_argument, NULL, ARG_DESERIALIZE              },
 383                 { "introspect",               optional_argument, NULL, ARG_INTROSPECT               },
 384                 { NULL,                       0,                 NULL, 0                            }
 385         };
 386
 387         int c, r;
 388
 389         assert(argc >= 1);
 390         assert(argv);
 391
 392         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
 393
 394                 switch (c) {
 395
 396                 case ARG_LOG_LEVEL:
 397                         if ((r = log_set_max_level_from_string(optarg)) < 0) {
 398                                 log_error("Failed to parse log level %s.", optarg);
 399                                 return r;
 400                         }
 401
 402                         break;
 403
 404                 case ARG_LOG_TARGET:
 405
 406                         if ((r = log_set_target_from_string(optarg)) < 0) {
 407                                 log_error("Failed to parse log target %s.", optarg);
 408                                 return r;
 409                         }
 410
 411                         break;
 412
 413                 case ARG_LOG_COLOR:
 414
 415                         if (optarg) {
 416                                 if ((r = log_show_color_from_string(optarg)) < 0) {
 417                                         log_error("Failed to parse log color setting %s.", optarg);
 418                                         return r;
 419                                 }
 420                         } else
 421                                 log_show_color(true);
 422
 423                         break;
 424
 425                 case ARG_LOG_LOCATION:
 426
 427                         if (optarg) {
 428                                 if ((r = log_show_location_from_string(optarg)) < 0) {
 429                                         log_error("Failed to parse log location setting %s.", optarg);
 430                                         return r;
 431                                 }
 432                         } else
 433                                 log_show_location(true);
 434
 435                         break;
 436
 437                 case ARG_UNIT:
 438
 439                         if ((r = set_default_unit(optarg)) < 0) {
 440                                 log_error("Failed to set default unit %s: %s", optarg, strerror(-r));
 441                                 return r;
 442                         }
 443
 444                         break;
 445
 446                 case ARG_RUNNING_AS: {
 447                         ManagerRunningAs as;
 448
 449                         if ((as = manager_running_as_from_string(optarg)) < 0) {
 450                                 log_error("Failed to parse running as value %s", optarg);
 451                                 return -EINVAL;
 452                         }
 453
 454                         running_as = as;
 455                         break;
 456                 }
 457
 458                 case ARG_TEST:
 459                         action = ACTION_TEST;
 460                         break;
 461
 462                 case ARG_DUMP_CONFIGURATION_ITEMS:
 463                         action = ACTION_DUMP_CONFIGURATION_ITEMS;
 464                         break;
 465
 466                 case ARG_CONFIRM_SPAWN:
 467                         confirm_spawn = true;
 468                         break;
 469
 470                 case ARG_DESERIALIZE: {
 471                         int fd;
 472                         FILE *f;
 473
 474                         if ((r = safe_atoi(optarg, &fd)) < 0 || fd < 0) {
 475                                 log_error("Failed to parse deserialize option %s.", optarg);
 476                                 return r;
 477                         }
 478
 479                         if (!(f = fdopen(fd, "r"))) {
 480                                 log_error("Failed to open serialization fd: %m");
 481                                 return r;
 482                         }
 483
 484                         if (serialization)
 485                                 fclose(serialization);
 486
 487                         serialization = f;
 488
 489                         break;
 490                 }
 491
 492                 case ARG_INTROSPECT: {
 493                         const char * const * i = NULL;
 494
 495                         for (i = bus_interface_table; *i; i += 2)
 496                                 if (!optarg || streq(i[0], optarg)) {
 497                                         fputs(DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
 498                                               "<node>\n", stdout);
 499                                         fputs(i[1], stdout);
 500                                         fputs("</node>\n", stdout);
 501
 502                                         if (optarg)
 503                                                 break;
 504                                 }
 505
 506                         if (!i[0] && optarg)
 507                                 log_error("Unknown interface %s.", optarg);
 508
 509                         action = ACTION_DONE;
 510                         break;
 511                 }
 512
 513                 case 'h':
 514                         action = ACTION_HELP;
 515                         break;
 516
 517                 case '?':
 518                         return -EINVAL;
 519
 520                 default:
 521                         log_error("Unknown option code %c", c);
 522                         return -EINVAL;
 523                 }
 524
 525         /* PID 1 will get the kernel arguments as parameters, which we
 526          * ignore and unconditionally read from
 527          * /proc/cmdline. However, we need to ignore those arguments
 528          * here. */
 529         if (running_as != MANAGER_SYSTEM && optind < argc) {
 530                 log_error("Excess arguments.");
 531                 return -EINVAL;
 532         }
 533
 534         return 0;
 535 }
 536
 537 static int help(void) {
 538
 539         printf("%s [options]\n\n"
 540                "Starts up and maintains the system or a session.\n\n"
 541                "  -h --help                      Show this help\n"
 542                "     --unit=UNIT                 Set default unit\n"
 543                "     --running-as=AS             Set running as (system, session)\n"
 544                "     --test                      Determine startup sequence, dump it and exit\n"
 545                "     --dump-configuration-items  Dump understood unit configuration items\n"
 546                "     --confirm-spawn             Ask for confirmation when spawning processes\n"
 547                "     --introspect[=INTERFACE]    Extract D-Bus interface data\n"
 548                "     --log-level=LEVEL           Set log level\n"
 549                "     --log-target=TARGET         Set log target (console, syslog, kmsg, syslog-or-kmsg, null)\n"
 550                "     --log-color[=0|1]           Highlight import log messages\n"
 551                "     --log-location[=0|1]        Include code location in log messages\n",
 552                program_invocation_short_name);
 553
 554         return 0;
 555 }
 556
 557 static int prepare_reexecute(Manager *m, FILE **_f, FDSet **_fds) {
 558         FILE *f = NULL;
 559         FDSet *fds = NULL;
 560         int r;
 561
 562         assert(m);
 563         assert(_f);
 564         assert(_fds);
 565
 566         if ((r = manager_open_serialization(&f)) < 0) {
 567                 log_error("Failed to create serialization faile: %s", strerror(-r));
 568                 goto fail;
 569         }
 570
 571         if (!(fds = fdset_new())) {
 572                 r = -ENOMEM;
 573                 log_error("Failed to allocate fd set: %s", strerror(-r));
 574                 goto fail;
 575         }
 576
 577         if ((r = manager_serialize(m, f, fds)) < 0) {
 578                 log_error("Failed to serialize state: %s", strerror(-r));
 579                 goto fail;
 580         }
 581
 582         if (fseeko(f, 0, SEEK_SET) < 0) {
 583                 log_error("Failed to rewind serialization fd: %m");
 584                 goto fail;
 585         }
 586
 587         if ((r = fd_cloexec(fileno(f), false)) < 0) {
 588                 log_error("Failed to disable O_CLOEXEC for serialization: %s", strerror(-r));
 589                 goto fail;
 590         }
 591
 592         if ((r = fdset_cloexec(fds, false)) < 0) {
 593                 log_error("Failed to disable O_CLOEXEC for serialization fds: %s", strerror(-r));
 594                 goto fail;
 595         }
 596
 597         *_f = f;
 598         *_fds = fds;
 599
 600         return 0;
 601
 602 fail:
 603         fdset_free(fds);
 604
 605         if (f)
 606                 fclose(f);
 607
 608         return r;
 609 }
 610
 611 int main(int argc, char *argv[]) {
 612         Manager *m = NULL;
 613         Unit *target = NULL;
 614         Job *job = NULL;
 615         int r, retval = 1;
 616         FDSet *fds = NULL;
 617         bool reexecute = false;
 618
 619         if (getpid() != 1 && strstr(program_invocation_short_name, "init")) {
 620                 /* This is compatbility support for SysV, where
 621                  * calling init as a user is identical to telinit. */
 622
 623                 errno = -ENOENT;
 624                 execv(SYSTEMCTL_BINARY_PATH, argv);
 625                 log_error("Failed to exec " SYSTEMCTL_BINARY_PATH ": %m");
 626                 return 1;
 627         }
 628
 629         log_show_color(true);
 630         log_show_location(false);
 631         log_set_max_level(LOG_DEBUG);
 632
 633         if (getpid() == 1) {
 634                 running_as = MANAGER_SYSTEM;
 635                 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 636         } else {
 637                 running_as = MANAGER_SESSION;
 638                 log_set_target(LOG_TARGET_CONSOLE);
 639         }
 640
 641         if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0)
 642                 goto finish;
 643
 644         /* Mount /proc, /sys and friends, so that /proc/cmdline and
 645          * /proc/$PID/fd is available. */
 646         if (geteuid() == 0)
 647                 if (mount_setup() < 0)
 648                         goto finish;
 649
 650         /* Reset all signal handlers. */
 651         assert_se(reset_all_signal_handlers() == 0);
 652
 653         /* If we are init, we can block sigkill. Yay. */
 654         ignore_signals(SIGNALS_IGNORE, -1);
 655
 656         if (running_as == MANAGER_SYSTEM)
 657                 if (parse_proc_cmdline() < 0)
 658                         goto finish;
 659
 660         log_parse_environment();
 661
 662         if (parse_argv(argc, argv) < 0)
 663                 goto finish;
 664
 665         if (action == ACTION_HELP) {
 666                 retval = help();
 667                 goto finish;
 668         } else if (action == ACTION_DUMP_CONFIGURATION_ITEMS) {
 669                 unit_dump_config_items(stdout);
 670                 retval = 0;
 671                 goto finish;
 672         } else if (action == ACTION_DONE) {
 673                 retval = 0;
 674                 goto finish;
 675         }
 676
 677         assert_se(action == ACTION_RUN || action == ACTION_TEST);
 678
 679         /* Remember open file descriptors for later deserialization */
 680         if (serialization) {
 681                 if ((r = fdset_new_fill(&fds)) < 0) {
 682                         log_error("Failed to allocate fd set: %s", strerror(-r));
 683                         goto finish;
 684                 }
 685
 686                 assert_se(fdset_remove(fds, fileno(serialization)) >= 0);
 687         } else
 688                 close_all_fds(NULL, 0);
 689
 690         /* Set up PATH unless it is already set */
 691         setenv("PATH",
 692                "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
 693                running_as == MANAGER_SYSTEM);
 694
 695         /* Move out of the way, so that we won't block unmounts */
 696         assert_se(chdir("/")  == 0);
 697
 698         if (running_as == MANAGER_SYSTEM) {
 699                 /* Become a session leader if we aren't one yet. */
 700                 setsid();
 701
 702                 /* Disable the umask logic */
 703                 umask(0);
 704         }
 705
 706         /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */
 707         dbus_connection_set_change_sigpipe(FALSE);
 708
 709         /* Reset the console, but only if this is really init and we
 710          * are freshly booted */
 711         if (running_as == MANAGER_SYSTEM && action == ACTION_RUN) {
 712                 console_setup(getpid() == 1 && !serialization);
 713                 make_null_stdio();
 714         }
 715
 716         /* Open the logging devices, if possible and necessary */
 717         log_open();
 718
 719         /* Make sure we leave a core dump without panicing the
 720          * kernel. */
 721         if (getpid() == 1)
 722                 install_crash_handler();
 723
 724         log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
 725
 726         if (running_as == MANAGER_SYSTEM) {
 727                 kmod_setup();
 728                 hostname_setup();
 729                 loopback_setup();
 730         }
 731
 732         if ((r = manager_new(running_as, confirm_spawn, &m)) < 0) {
 733                 log_error("Failed to allocate manager object: %s", strerror(-r));
 734                 goto finish;
 735         }
 736
 737         if ((r = manager_startup(m, serialization, fds)) < 0)
 738                 log_error("Failed to fully start up daemon: %s", strerror(-r));
 739
 740         if (fds) {
 741                 /* This will close all file descriptors that were opened, but
 742                  * not claimed by any unit. */
 743
 744                 fdset_free(fds);
 745                 fds = NULL;
 746         }
 747
 748         if (serialization) {
 749                 fclose(serialization);
 750                 serialization = NULL;
 751         } else {
 752                 log_debug("Activating default unit: %s", default_unit);
 753
 754                 if ((r = manager_load_unit(m, default_unit, NULL, &target)) < 0) {
 755                         log_error("Failed to load default target: %s", strerror(-r));
 756
 757                         log_info("Trying to load rescue target...");
 758                         if ((r = manager_load_unit(m, SPECIAL_RESCUE_TARGET, NULL, &target)) < 0) {
 759                                 log_error("Failed to load rescue target: %s", strerror(-r));
 760                                 goto finish;
 761                         }
 762                 }
 763
 764                 if (action == ACTION_TEST) {
 765                         printf("-> By units:\n");
 766                         manager_dump_units(m, stdout, "\t");
 767                 }
 768
 769                 if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, false, &job)) < 0) {
 770                         log_error("Failed to start default target: %s", strerror(-r));
 771                         goto finish;
 772                 }
 773
 774                 if (action == ACTION_TEST) {
 775                         printf("-> By jobs:\n");
 776                         manager_dump_jobs(m, stdout, "\t");
 777                         retval = 0;
 778                         goto finish;
 779                 }
 780         }
 781
 782         for (;;) {
 783                 if ((r = manager_loop(m)) < 0) {
 784                         log_error("Failed to run mainloop: %s", strerror(-r));
 785                         goto finish;
 786                 }
 787
 788                 switch (m->exit_code) {
 789
 790                 case MANAGER_EXIT:
 791                         retval = 0;
 792                         log_debug("Exit.");
 793                         goto finish;
 794
 795                 case MANAGER_RELOAD:
 796                         if ((r = manager_reload(m)) < 0)
 797                                 log_error("Failed to reload: %s", strerror(-r));
 798                         break;
 799
 800                 case MANAGER_REEXECUTE:
 801                         if (prepare_reexecute(m, &serialization, &fds) < 0)
 802                                 goto finish;
 803
 804                         reexecute = true;
 805                         log_debug("Reexecuting.");
 806                         goto finish;
 807
 808                 default:
 809                         assert_not_reached("Unknown exit code.");
 810                 }
 811         }
 812
 813 finish:
 814         if (m)
 815                 manager_free(m);
 816
 817         free(default_unit);
 818
 819         dbus_shutdown();
 820
 821         if (reexecute) {
 822                 const char *args[11];
 823                 unsigned i = 0;
 824                 char sfd[16];
 825
 826                 assert(serialization);
 827                 assert(fds);
 828
 829                 args[i++] = SYSTEMD_BINARY_PATH;
 830
 831                 args[i++] = "--log-level";
 832                 args[i++] = log_level_to_string(log_get_max_level());
 833
 834                 args[i++] = "--log-target";
 835                 args[i++] = log_target_to_string(log_get_target());
 836
 837                 args[i++] = "--running-as";
 838                 args[i++] = manager_running_as_to_string(running_as);
 839
 840                 snprintf(sfd, sizeof(sfd), "%i", fileno(serialization));
 841                 char_array_0(sfd);
 842
 843                 args[i++] = "--deserialize";
 844                 args[i++] = sfd;
 845
 846                 if (confirm_spawn)
 847                         args[i++] = "--confirm-spawn";
 848
 849                 args[i++] = NULL;
 850
 851                 assert(i <= ELEMENTSOF(args));
 852
 853                 execv(args[0], (char* const*) args);
 854
 855                 log_error("Failed to reexecute: %m");
 856         }
 857
 858         if (serialization)
 859                 fclose(serialization);
 860
 861         if (fds)
 862                 fdset_free(fds);
 863
 864         if (getpid() == 1)
 865                 freeze();
 866
 867         return retval;
 868 }