chiark / gitweb /
main: install crash handler for creating core dumps
[elogind.git] / main.c
diff --git a/main.c b/main.c
index 47292bb2041cdca50a0b4955e3e5e956ed611f06..4aa63cba77310ac27fd56a2476b8703a2fab6ffc 100644 (file)
--- a/main.c
+++ b/main.c
 /*-*- 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 "manager.h"
 #include "log.h"
+#include "mount-setup.h"
+#include "hostname-setup.h"
+#include "load-fragment.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;
+
+_noreturn static void freeze(void) {
+        for (;;)
+                pause();
+}
+
+_noreturn static void crash(int sig) {
+
+        if (!dump_core)
+                log_error("Caught <%s>, not dumping core.", strsignal(sig));
+        else {
+                pid_t pid;
+
+                log_warning("Caugh <%s>, dumping core.", strsignal(sig));
+
+                if ((pid = fork()) < 0)
+                        log_error("Caught <%s>, cannot dump core: %s", strsignal(sig), strerror(errno));
+
+                else if (pid == 0) {
+                        struct sigaction sa;
+                        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);
+                }
+        }
+
+        log_error("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(SIGABRT, &sa, NULL) == 0);
+}
+
+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 {
+                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
+        };
+
+        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 },
+                { 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 'h':
+                        action = ACTION_HELP;
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        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)\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",
+               __progname);
+
+        return 0;
+}
 
 int main(int argc, char *argv[]) {
         Manager *m = NULL;
-        Name *milestone = NULL, *syslog = NULL;
+        Unit *target = NULL;
         Job *job = NULL;
         int r, retval = 1;
 
-        assert_se(chdir("test1") == 0);
+        if (getpid() == 1)
+                running_as = MANAGER_INIT;
+        else if (getuid() == 0)
+                running_as = MANAGER_SYSTEM;
+        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);
+
+        /* Close all open files */
+        assert_se(close_all_fds(NULL, 0) == 0);
+
+        if (running_as != MANAGER_SESSION)
+                if (parse_proc_cmdline() < 0)
+                        goto finish;
+
+        log_parse_environment();
 
-        if (!(m = manager_new()) < 0) {
-                log_error("Failed to allocate manager object: %s", strerror(ENOMEM));
+        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;
         }
 
-        if ((r = manager_load_name(m, "default.milestone", &milestone)) < 0) {
-                log_error("Failed to load default milestone: %s", strerror(-r));
+        assert_se(action == ACTION_RUN || action == ACTION_TEST);
+
+        /* 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);
+
+        /* 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);
+
+        /* Open the logging devices, if possible and necessary*/
+        log_open_syslog();
+        log_open_kmsg();
+
+        install_crash_handler();
+        assert(!"esel");
+
+        log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as));
+
+        if (running_as == MANAGER_INIT)
+                hostname_setup();
+
+        if ((r = manager_new(running_as, &m)) < 0) {
+                log_error("Failed to allocate manager object: %s", strerror(-r));
                 goto finish;
         }
 
-        if ((r = manager_load_name(m, "syslog.socket", &syslog)) < 0) {
-                log_error("Failed to load syslog socket: %s", strerror(-r));
+        if ((r = manager_coldplug(m)) < 0) {
+                log_error("Failed to retrieve coldplug information: %s", strerror(-r));
                 goto finish;
         }
 
-        if ((r = manager_add_job(m, JOB_START, milestone, JOB_REPLACE, false, &job)) < 0) {
-                log_error("Failed to start default milestone: %s", strerror(-r));
+        log_debug("Activating default unit: %s", default_unit);
+
+        if ((r = manager_load_unit(m, default_unit, &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, &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;
         }
 
-        printf("- By names:\n");
-        manager_dump_names(m, stdout, "\t");
+        if (action == ACTION_TEST) {
+                printf("→ By jobs:\n");
+                manager_dump_jobs(m, stdout, "\t");
 
-        printf("- By jobs:\n");
-        manager_dump_jobs(m, stdout, "\t");
+                if (getpid() == 1)
+                        pause();
 
-        manager_run_jobs(m);
+                retval = 0;
+                goto finish;
+        }
 
-        manager_loop(m);
+        if ((r = manager_loop(m)) < 0) {
+                log_error("Failed to run mainloop: %s", strerror(-r));
+                goto finish;
+        }
 
         retval = 0;
 
+        log_debug("Exit.");
+
 finish:
         if (m)
                 manager_free(m);
 
+        free(default_unit);
+
+        dbus_shutdown();
+
         return retval;
 }