/*-*- Mode: C; c-basic-offset: 8 -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <dbus/dbus.h> #include <stdio.h> #include <errno.h> #include <string.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <getopt.h> #include <signal.h> #include <sys/wait.h> #include <fcntl.h> #include "manager.h" #include "log.h" #include "mount-setup.h" #include "hostname-setup.h" #include "loopback-setup.h" #include "load-fragment.h" #include "fdset.h" static enum { ACTION_RUN, ACTION_HELP, ACTION_TEST, ACTION_DUMP_CONFIGURATION_ITEMS } action = ACTION_RUN; static char *default_unit = NULL; static ManagerRunningAs running_as = _MANAGER_RUNNING_AS_INVALID; static bool dump_core = true; static bool crash_shell = false; static int crash_chvt = -1; static bool confirm_spawn = false; static FILE* serialization = NULL; _noreturn static void freeze(void) { for (;;) pause(); } static void nop_handler(int sig) { } _noreturn static void crash(int sig) { if (!dump_core) log_error("Caught <%s>, not dumping core.", strsignal(sig)); else { struct sigaction sa; pid_t pid; /* We want to wait for the core process, hence let's enable SIGCHLD */ zero(sa); sa.sa_handler = nop_handler; sa.sa_flags = SA_NOCLDSTOP|SA_RESTART; assert_se(sigaction(SIGCHLD, &sa, NULL) == 0); if ((pid = fork()) < 0) log_error("Caught <%s>, cannot fork for core dump: %s", strsignal(sig), strerror(errno)); else if (pid == 0) { struct rlimit rl; /* Enable default signal handler for core dump */ zero(sa); sa.sa_handler = SIG_DFL; assert_se(sigaction(sig, &sa, NULL) == 0); /* Don't limit the core dump size */ zero(rl); rl.rlim_cur = RLIM_INFINITY; rl.rlim_max = RLIM_INFINITY; setrlimit(RLIMIT_CORE, &rl); /* Just to be sure... */ assert_se(chdir("/") == 0); /* Raise the signal again */ raise(sig); assert_not_reached("We shouldn't be here..."); _exit(1); } else { int status, r; /* Order things nicely. */ if ((r = waitpid(pid, &status, 0)) < 0) log_error("Caught <%s>, waitpid() failed: %s", strsignal(sig), strerror(errno)); else if (!WCOREDUMP(status)) log_error("Caught <%s>, core dump failed.", strsignal(sig)); else log_error("Caught <%s>, dumped core as pid %llu.", strsignal(sig), (unsigned long long) pid); } } if (crash_chvt) chvt(crash_chvt); if (crash_shell) { struct sigaction sa; pid_t pid; log_info("Executing crash shell in 10s..."); sleep(10); /* Let the kernel reap children for us */ zero(sa); sa.sa_handler = SIG_IGN; sa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT|SA_RESTART; assert_se(sigaction(SIGCHLD, &sa, NULL) == 0); if ((pid = fork()) < 0) log_error("Failed to fork off crash shell: %s", strerror(errno)); else if (pid == 0) { int fd, r; if ((fd = acquire_terminal("/dev/console", false, true)) < 0) { log_error("Failed to acquire terminal: %s", strerror(-fd)); _exit(1); } if ((r = make_stdio(fd)) < 0) { log_error("Failed to duplicate terminal fd: %s", strerror(-r)); _exit(1); } execl("/bin/sh", "/bin/sh", NULL); log_error("execl() failed: %s", strerror(errno)); _exit(1); } log_info("Successfully spawned crash shall as pid %llu.", (unsigned long long) pid); } log_info("Freezing execution."); freeze(); } static void install_crash_handler(void) { struct sigaction sa; zero(sa); sa.sa_handler = crash; sa.sa_flags = SA_NODEFER; assert_se(sigaction(SIGSEGV, &sa, NULL) == 0); assert_se(sigaction(SIGILL, &sa, NULL) == 0); assert_se(sigaction(SIGFPE, &sa, NULL) == 0); assert_se(sigaction(SIGBUS, &sa, NULL) == 0); assert_se(sigaction(SIGQUIT, &sa, NULL) == 0); assert_se(sigaction(SIGABRT, &sa, NULL) == 0); } static int make_null_stdio(void) { int null_fd, r; if ((null_fd = open("/dev/null", O_RDWR)) < 0) { log_error("Failed to open /dev/null: %m"); return -errno; } if ((r = make_stdio(null_fd)) < 0) log_warning("Failed to dup2() device: %s", strerror(-r)); return r; } static int console_setup(bool do_reset) { int tty_fd, r; /* If we are init, we connect stdin/stdout/stderr to /dev/null * and make sure we don't have a controlling tty. */ release_terminal(); if (!do_reset) return 0; if ((tty_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) { log_error("Failed to open /dev/console: %s", strerror(-tty_fd)); return -tty_fd; } if ((r = reset_terminal(tty_fd)) < 0) log_error("Failed to reset /dev/console: %s", strerror(-r)); close_nointr_nofail(tty_fd); return r; } static int set_default_unit(const char *u) { char *c; assert(u); if (!(c = strdup(u))) return -ENOMEM; free(default_unit); default_unit = c; return 0; } static int parse_proc_cmdline_word(const char *word) { static const char * const rlmap[] = { "single", SPECIAL_RUNLEVEL1_TARGET, "-s", SPECIAL_RUNLEVEL1_TARGET, "s", SPECIAL_RUNLEVEL1_TARGET, "S", SPECIAL_RUNLEVEL1_TARGET, "1", SPECIAL_RUNLEVEL1_TARGET, "2", SPECIAL_RUNLEVEL2_TARGET, "3", SPECIAL_RUNLEVEL3_TARGET, "4", SPECIAL_RUNLEVEL4_TARGET, "5", SPECIAL_RUNLEVEL5_TARGET }; if (startswith(word, "systemd.default=")) return set_default_unit(word + 16); else if (startswith(word, "systemd.log_target=")) { if (log_set_target_from_string(word + 19) < 0) log_warning("Failed to parse log target %s. Ignoring.", word + 19); } else if (startswith(word, "systemd.log_level=")) { if (log_set_max_level_from_string(word + 18) < 0) log_warning("Failed to parse log level %s. Ignoring.", word + 18); } else if (startswith(word, "systemd.dump_core=")) { int r; if ((r = parse_boolean(word + 18)) < 0) log_warning("Failed to parse dump core switch %s, Ignoring.", word + 18); else dump_core = r; } else if (startswith(word, "systemd.crash_shell=")) { int r; if ((r = parse_boolean(word + 20)) < 0) log_warning("Failed to parse crash shell switch %s, Ignoring.", word + 20); else crash_shell = r; } else if (startswith(word, "systemd.confirm_spawn=")) { int r; if ((r = parse_boolean(word + 22)) < 0) log_warning("Failed to parse confirm spawn switch %s, Ignoring.", word + 22); else confirm_spawn = r; } else if (startswith(word, "systemd.crash_chvt=")) { int k; if (safe_atoi(word + 19, &k) < 0) log_warning("Failed to parse crash chvt switch %s, Ignoring.", word + 19); else crash_chvt = k; } else if (startswith(word, "systemd.")) { log_warning("Unknown kernel switch %s. Ignoring.", word); log_info("Supported kernel switches:"); log_info("systemd.default=UNIT Default unit to start"); log_info("systemd.log_target=console|kmsg|syslog Log target"); log_info("systemd.log_level=LEVEL Log level"); log_info("systemd.dump_core=0|1 Dump core on crash"); log_info("systemd.crash_shell=0|1 On crash run shell"); log_info("systemd.crash_chvt=N Change to VT #N on crash"); log_info("systemd.confirm_spawn=0|1 Confirm every process spawn"); } else { unsigned i; /* SysV compatibility */ for (i = 0; i < ELEMENTSOF(rlmap); i += 2) if (streq(word, rlmap[i])) return set_default_unit(rlmap[i+1]); } return 0; } static int parse_proc_cmdline(void) { char *line; int r; char *w; size_t l; char *state; if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) { log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno)); return 0; } FOREACH_WORD_QUOTED(w, l, line, state) { char *word; if (!(word = strndup(w, l))) { r = -ENOMEM; goto finish; } r = parse_proc_cmdline_word(word); free(word); if (r < 0) goto finish; } r = 0; finish: free(line); return r; } static int parse_argv(int argc, char *argv[]) { enum { ARG_LOG_LEVEL = 0x100, ARG_LOG_TARGET, ARG_DEFAULT, ARG_RUNNING_AS, ARG_TEST, ARG_DUMP_CONFIGURATION_ITEMS, ARG_CONFIRM_SPAWN, ARG_DESERIALIZE }; static const struct option options[] = { { "log-level", required_argument, NULL, ARG_LOG_LEVEL }, { "log-target", required_argument, NULL, ARG_LOG_TARGET }, { "default", required_argument, NULL, ARG_DEFAULT }, { "running-as", required_argument, NULL, ARG_RUNNING_AS }, { "test", no_argument, NULL, ARG_TEST }, { "help", no_argument, NULL, 'h' }, { "dump-configuration-items", no_argument, NULL, ARG_DUMP_CONFIGURATION_ITEMS }, { "confirm-spawn", no_argument, NULL, ARG_CONFIRM_SPAWN }, { "deserialize", required_argument, NULL, ARG_DESERIALIZE }, { NULL, 0, NULL, 0 } }; int c, r; assert(argc >= 1); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) switch (c) { case ARG_LOG_LEVEL: if ((r = log_set_max_level_from_string(optarg)) < 0) { log_error("Failed to parse log level %s.", optarg); return r; } break; case ARG_LOG_TARGET: if ((r = log_set_target_from_string(optarg)) < 0) { log_error("Failed to parse log target %s.", optarg); return r; } break; case ARG_DEFAULT: if ((r = set_default_unit(optarg)) < 0) { log_error("Failed to set default unit %s: %s", optarg, strerror(-r)); return r; } break; case ARG_RUNNING_AS: { ManagerRunningAs as; if ((as = manager_running_as_from_string(optarg)) < 0) { log_error("Failed to parse running as value %s", optarg); return -EINVAL; } running_as = as; break; } case ARG_TEST: action = ACTION_TEST; break; case ARG_DUMP_CONFIGURATION_ITEMS: action = ACTION_DUMP_CONFIGURATION_ITEMS; break; case ARG_CONFIRM_SPAWN: confirm_spawn = true; break; case ARG_DESERIALIZE: { int fd; FILE *f; if ((r = safe_atoi(optarg, &fd)) < 0 || fd < 0) { log_error("Failed to parse deserialize option %s.", optarg); return r; } if (!(f = fdopen(fd, "r"))) { log_error("Failed to open serialization fd: %m"); return r; } if (serialization) fclose(serialization); serialization = f; break; } case 'h': action = ACTION_HELP; break; case '?': return -EINVAL; default: log_error("Unknown option code %c", c); return -EINVAL; } /* PID 1 will get the kernel arguments as parameters, which we * ignore and unconditionally read from * /proc/cmdline. However, we need to ignore those arguments * here. */ if (running_as != MANAGER_INIT && optind < argc) { log_error("Excess arguments."); return -EINVAL; } return 0; } static int help(void) { printf("%s [options]\n\n" " -h --help Show this help\n" " --default=UNIT Set default unit\n" " --log-level=LEVEL Set log level\n" " --log-target=TARGET Set log target (console, syslog, kmsg, syslog-or-kmsg)\n" " --running-as=AS Set running as (init, system, session)\n" " --test Determine startup sequence, dump it and exit\n" " --dump-configuration-items Dump understood unit configuration items\n" " --confirm-spawn Ask for confirmation when spawning processes\n", __progname); return 0; } static int prepare_reexecute(Manager *m, FILE **_f, FDSet **_fds) { FILE *f = NULL; FDSet *fds = NULL; int r; assert(m); assert(_f); assert(_fds); if ((r = manager_open_serialization(&f)) < 0) { log_error("Failed to create serialization faile: %s", strerror(-r)); goto fail; } if (!(fds = fdset_new())) { r = -ENOMEM; log_error("Failed to allocate fd set: %s", strerror(-r)); goto fail; } if ((r = manager_serialize(m, f, fds)) < 0) { log_error("Failed to serialize state: %s", strerror(-r)); goto fail; } if (fseeko(f, 0, SEEK_SET) < 0) { log_error("Failed to rewind serialization fd: %m"); goto fail; } if ((r = fd_cloexec(fileno(f), false)) < 0) { log_error("Failed to disable O_CLOEXEC for serialization: %s", strerror(-r)); goto fail; } if ((r = fdset_cloexec(fds, false)) < 0) { log_error("Failed to disable O_CLOEXEC for serialization fds: %s", strerror(-r)); goto fail; } *_f = f; *_fds = fds; return 0; fail: fdset_free(fds); if (f) fclose(f); return r; } int main(int argc, char *argv[]) { Manager *m = NULL; Unit *target = NULL; Job *job = NULL; int r, retval = 1; FDSet *fds = NULL; bool reexecute = false; if (getpid() == 1) { running_as = MANAGER_INIT; log_set_target(LOG_TARGET_SYSLOG_OR_KMSG); } else running_as = MANAGER_SESSION; if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0) goto finish; /* Mount /proc, /sys and friends, so that /proc/cmdline and * /proc/$PID/fd is available. */ if (mount_setup() < 0) goto finish; /* Reset all signal handlers. */ assert_se(reset_all_signal_handlers() == 0); /* If we are init, we can block sigkill. Yay. */ ignore_signal(SIGKILL); ignore_signal(SIGPIPE); if (running_as != MANAGER_SESSION) if (parse_proc_cmdline() < 0) goto finish; log_parse_environment(); if (parse_argv(argc, argv) < 0) goto finish; if (action == ACTION_HELP) { retval = help(); goto finish; } else if (action == ACTION_DUMP_CONFIGURATION_ITEMS) { unit_dump_config_items(stdout); retval = 0; goto finish; } assert_se(action == ACTION_RUN || action == ACTION_TEST); /* Remember open file descriptors for later deserialization */ if (serialization) { if ((r = fdset_new_fill(&fds)) < 0) { log_error("Failed to allocate fd set: %s", strerror(-r)); goto finish; } assert_se(fdset_remove(fds, fileno(serialization)) >= 0); } else close_all_fds(NULL, 0); /* Set up PATH unless it is already set */ setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", running_as == MANAGER_INIT); /* Move out of the way, so that we won't block unmounts */ assert_se(chdir("/") == 0); if (running_as != MANAGER_SESSION) { /* Become a session leader if we aren't one yet. */ setsid(); /* Disable the umask logic */ umask(0); } /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */ dbus_connection_set_change_sigpipe(FALSE); /* Reset the console, but only if this is really init and we * are freshly booted */ if (running_as != MANAGER_SESSION && action == ACTION_RUN) { console_setup(getpid() == 1 && !serialization); make_null_stdio(); } /* Open the logging devices, if possible and necessary */ log_open(); /* Make sure we leave a core dump without panicing the * kernel. */ if (getpid() == 1) install_crash_handler(); log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as)); if (running_as == MANAGER_INIT) { hostname_setup(); loopback_setup(); } if ((r = manager_new(running_as, confirm_spawn, &m)) < 0) { log_error("Failed to allocate manager object: %s", strerror(-r)); goto finish; } if ((r = manager_startup(m, serialization, fds)) < 0) log_error("Failed to fully start up daemon: %s", strerror(-r)); if (fds) { /* This will close all file descriptors that were opened, but * not claimed by any unit. */ fdset_free(fds); fds = NULL; } if (serialization) { fclose(serialization); serialization = NULL; } else { log_debug("Activating default unit: %s", default_unit); if ((r = manager_load_unit(m, default_unit, NULL, &target)) < 0) { log_error("Failed to load default target: %s", strerror(-r)); log_info("Trying to load rescue target..."); if ((r = manager_load_unit(m, SPECIAL_RESCUE_TARGET, NULL, &target)) < 0) { log_error("Failed to load rescue target: %s", strerror(-r)); goto finish; } } if (action == ACTION_TEST) { printf("-> By units:\n"); manager_dump_units(m, stdout, "\t"); } if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, false, &job)) < 0) { log_error("Failed to start default target: %s", strerror(-r)); goto finish; } if (action == ACTION_TEST) { printf("-> By jobs:\n"); manager_dump_jobs(m, stdout, "\t"); retval = 0; goto finish; } } for (;;) { if ((r = manager_loop(m)) < 0) { log_error("Failed to run mainloop: %s", strerror(-r)); goto finish; } switch (m->exit_code) { case MANAGER_EXIT: retval = 0; log_debug("Exit."); goto finish; case MANAGER_RELOAD: if ((r = manager_reload(m)) < 0) log_error("Failed to reload: %s", strerror(-r)); break; case MANAGER_REEXECUTE: if (prepare_reexecute(m, &serialization, &fds) < 0) goto finish; reexecute = true; log_debug("Reexecuting."); goto finish; default: assert_not_reached("Unknown exit code."); } } finish: if (m) manager_free(m); free(default_unit); dbus_shutdown(); if (reexecute) { const char *args[11]; unsigned i = 0; char sfd[16]; assert(serialization); assert(fds); args[i++] = SYSTEMD_BINARY_PATH; args[i++] = "--log-level"; args[i++] = log_level_to_string(log_get_max_level()); args[i++] = "--log-target"; args[i++] = log_target_to_string(log_get_target()); args[i++] = "--running-as"; args[i++] = manager_running_as_to_string(running_as); snprintf(sfd, sizeof(sfd), "%i", fileno(serialization)); char_array_0(sfd); args[i++] = "--deserialize"; args[i++] = sfd; if (confirm_spawn) args[i++] = "--confirm-spawn"; args[i++] = NULL; assert(i <= ELEMENTSOF(args)); execv(args[0], (char* const*) args); log_error("Failed to reexecute: %m"); } if (serialization) fclose(serialization); if (fds) fdset_free(fds); if (getpid() == 1) freeze(); return retval; }