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-rw-r--r--src/main.c787
1 files changed, 787 insertions, 0 deletions
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 000000000..bba2975e4
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,787 @@
+/*-*- 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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-23 23:37:12 +0000