chiark / gitweb /
main: never reset console unless pid=1, to make sure that we don't kill X when somebo...
[elogind.git] / main.c
diff --git a/main.c b/main.c
index acfa35fe6e76f309bb92c98dbe30352dcfbbc4c3..0aa3796e878755fe3bce4df60f508c8d69fe9870 100644 (file)
--- a/main.c
+++ b/main.c
 #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 "load-fragment.h"
+#include "fdset.h"
 
 static enum {
         ACTION_RUN,
-        ACTION_HELP
+        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) {
+                        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 console_setup(bool do_reset) {
+        int tty_fd = -1, null_fd = -1, r = 0;
+
+        /* If we are init, we connect stdout/stderr to /dev/console
+         * and stdin to /dev/null and make sure we don't have a
+         * controlling tty. */
+
+        release_terminal();
+
+        if ((tty_fd = open_terminal("/dev/console", O_WRONLY)) < 0) {
+                log_error("Failed to open /dev/console: %s", strerror(-tty_fd));
+                r = -tty_fd;
+                goto finish;
+        }
+
+        if ((null_fd = open("/dev/null", O_RDONLY)) < 0) {
+                log_error("Failed to open /dev/null: %m");
+                r = -errno;
+                goto finish;
+        }
+
+        assert(tty_fd >= 3);
+        assert(null_fd >= 3);
+
+        if (do_reset)
+                if (reset_terminal(tty_fd) < 0)
+                        log_error("Failed to reset /dev/console: %m");
+
+        if (dup2(tty_fd, STDOUT_FILENO) < 0 ||
+            dup2(tty_fd, STDERR_FILENO) < 0 ||
+            dup2(null_fd, STDIN_FILENO) < 0) {
+                log_error("Failed to dup2() device: %m");
+                r = -errno;
+                goto finish;
+        }
+
+        r = 0;
+
+finish:
+        if (tty_fd >= 0)
+                close_nointr_nofail(tty_fd);
+
+        if (null_fd >= 0)
+                close_nointr_nofail(null_fd);
+
+        return r;
+}
 
 static int set_default_unit(const char *u) {
         char *c;
@@ -68,7 +240,7 @@ static int parse_proc_cmdline_word(const char *word) {
         };
 
         if (startswith(word, "systemd.default="))
-                return set_default_unit(word + 15);
+                return set_default_unit(word + 16);
 
         else if (startswith(word, "systemd.log_target=")) {
 
@@ -80,11 +252,56 @@ static int parse_proc_cmdline_word(const char *word) {
                 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]);
@@ -132,15 +349,25 @@ static int parse_argv(int argc, char *argv[]) {
         enum {
                 ARG_LOG_LEVEL = 0x100,
                 ARG_LOG_TARGET,
-                ARG_DEFAULT
+                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 },
-                { "help",       no_argument,       NULL, 'h' },
-                { NULL,         0,                 NULL, 0 }
+                { "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;
@@ -178,6 +405,52 @@ static int parse_argv(int argc, char *argv[]) {
 
                         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;
@@ -190,47 +463,112 @@ static int parse_argv(int argc, char *argv[]) {
                         return -EINVAL;
                 }
 
-        if (optind < argc) {
-                log_error("Too many 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)\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"
+               "     --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;
+        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. */
-        mount_setup();
+        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 we are init, we can block sigkill. Yay. */
+        ignore_signal(SIGKILL);
+        ignore_signal(SIGPIPE);
 
-        if (parse_proc_cmdline() < 0)
-                goto finish;
+        if (running_as != MANAGER_SESSION)
+                if (parse_proc_cmdline() < 0)
+                        goto finish;
 
         log_parse_environment();
 
@@ -240,62 +578,143 @@ int main(int argc, char *argv[]) {
         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);
+        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);
 
-        /* Become a session leader if we aren't one yet. */
-        setsid();
+        if (running_as != MANAGER_SESSION) {
+                /* Become a session leader if we aren't one yet. */
+                setsid();
 
-        /* Disable the umask logic */
-        umask(0);
+                /* Disable the umask logic */
+                umask(0);
+        }
+
+        /* Reset the console, but only if this is really init and we
+         * are freshly booted */
+        if (running_as == MANAGER_INIT)
+                console_setup(getpid() == 1 && !serialization);
 
         /* 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*/
+        /* Open the logging devices, if possible and necessary */
         log_open_syslog();
         log_open_kmsg();
 
-        if ((r = manager_new(&m)) < 0) {
+        /* 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();
+
+        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_coldplug(m)) < 0) {
-                log_error("Failed to retrieve coldplug information: %s", strerror(-r));
-                goto finish;
-        }
+        if ((r = manager_startup(m, serialization, fds)) < 0)
+                log_error("Failed to fully startup daemon: %s", strerror(-r));
 
-        log_debug("Activating default unit: %s", default_unit);
+        if (fds) {
+                /* This will close all file descriptors that were opened, but
+                 * not claimed by any unit. */
 
-        if ((r = manager_load_unit(m, default_unit, &target)) < 0) {
-                log_error("Failed to load default target: %s", strerror(-r));
-                goto finish;
+                fdset_free(fds);
+                fds = NULL;
         }
 
-        printf("→ By units:\n");
-        manager_dump_units(m, stdout, "\t");
+        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));
 
-        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;
-        }
+                        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;
+                        }
+                }
 
-        printf("→ By jobs:\n");
-        manager_dump_jobs(m, stdout, "\t");
+                if (action == ACTION_TEST) {
+                        printf("→ By units:\n");
+                        manager_dump_units(m, stdout, "\t");
+                }
 
-        if ((r = manager_loop(m)) < 0) {
-                log_error("Failed to run mainloop: %s", strerror(-r));
-                goto finish;
+                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;
+                }
         }
 
-        retval = 0;
+        for (;;) {
+                if ((r = manager_loop(m)) < 0) {
+                        log_error("Failed to run mainloop: %s", strerror(-r));
+                        goto finish;
+                }
 
-        log_debug("Exit.");
+                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)
@@ -305,5 +724,51 @@ finish:
 
         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;
 }