#include <sys/mman.h>

#include <sys/types.h>

#include <sys/reboot.h>

#include <linux/reboot.h>

#include <sys/wait.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/mount.h>

#include <sys/syscall.h>

#include <fcntl.h>

#include <dirent.h>

#include <errno.h>

#include <unistd.h>

#include <signal.h>

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

#include "missing.h"

#include "log.h"

#include "umount.h"

#include "util.h"

#include "mkdir.h"

#include "virt.h"

#include "watchdog.h"

#include "killall.h"

#define FINALIZE_ATTEMPTS 50

static int prepare_new_root(void) {

static const char dirs[] =

"/run/initramfs/oldroot\0"

"/run/initramfs/proc\0"

"/run/initramfs/sys\0"

"/run/initramfs/dev\0"

"/run/initramfs/run\0";

const char *dir;

if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {

log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");

return -errno;

}

if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {

log_error("Failed to make /run/initramfs private mount: %m");

return -errno;

}

NULSTR_FOREACH(dir, dirs)

if (mkdir_p_label(dir, 0755) < 0 && errno != EEXIST) {

log_error("Failed to mkdir %s: %m", dir);

return -errno;

}

if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {

log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");

return -errno;

}

if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {

log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");

return -errno;

}

if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {

log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");

return -errno;

}

if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {

log_error("Failed to mount bind /run on /run/initramfs/run: %m");

return -errno;

}

return 0;

}

static int pivot_to_new_root(void) {

if (chdir("/run/initramfs") < 0) {

log_error("Failed to change directory to /run/initramfs: %m");

return -errno;

}

/* Work-around for a kernel bug: for some reason the kernel

if (mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) < 0)

log_warning("Failed to make \"/\" private mount: %m");

if (pivot_root(".", "oldroot") < 0) {

log_error("pivot failed: %m");

/* only chroot if pivot root succeeded */

return -errno;

}

chroot(".");

setsid();

make_console_stdio();

log_info("Successfully changed into root pivot.");

return 0;

}

int main(int argc, char *argv[]) {

int cmd, r;

unsigned retries;

bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;

bool in_container, use_watchdog = false;

char *arguments[3];

log_parse_environment();

log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */

log_open();

umask(0022);

if (getpid() != 1) {

log_error("Not executed by init (pid 1).");

r = -EPERM;

goto error;

}

if (argc != 2) {

log_error("Invalid number of arguments.");

r = -EINVAL;

goto error;

}

in_container = detect_container(NULL) > 0;

if (streq(argv[1], "reboot"))

cmd = RB_AUTOBOOT;

else if (streq(argv[1], "poweroff"))

cmd = RB_POWER_OFF;

else if (streq(argv[1], "halt"))

cmd = RB_HALT_SYSTEM;

else if (streq(argv[1], "kexec"))

cmd = LINUX_REBOOT_CMD_KEXEC;

else {

log_error("Unknown action '%s'.", argv[1]);

r = -EINVAL;

goto error;

}

use_watchdog = !!getenv("WATCHDOG_USEC");

/* lock us into memory */

mlockall(MCL_CURRENT|MCL_FUTURE);

log_info("Sending SIGTERM to remaining processes...");

broadcast_signal(SIGTERM, true);

log_info("Sending SIGKILL to remaining processes...");

broadcast_signal(SIGKILL, true);

if (in_container) {

need_swapoff = false;

need_dm_detach = false;

need_loop_detach = false;

}

/* Unmount all mountpoints, swaps, and loopback devices */

for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {

bool changed = false;

if (use_watchdog)

watchdog_ping();

if (need_umount) {

log_info("Unmounting file systems.");

r = umount_all(&changed);

if (r == 0) {

need_umount = false;

log_info("All filesystems unmounted.");

} else if (r > 0)

log_info("Not all file systems unmounted, %d left.", r);

else

log_error("Failed to unmount file systems: %s", strerror(-r));

}

if (need_swapoff) {

log_info("Deactivating swaps.");

r = swapoff_all(&changed);

if (r == 0) {

need_swapoff = false;

log_info("All swaps deactivated.");

} else if (r > 0)

log_info("Not all swaps deactivated, %d left.", r);

else

log_error("Failed to deactivate swaps: %s", strerror(-r));

}

if (need_loop_detach) {

log_info("Detaching loop devices.");

r = loopback_detach_all(&changed);

if (r == 0) {

need_loop_detach = false;

log_info("All loop devices detached.");

} else if (r > 0)

log_info("Not all loop devices detached, %d left.", r);

else

log_error("Failed to detach loop devices: %s", strerror(-r));

}

if (need_dm_detach) {

log_info("Detaching DM devices.");

r = dm_detach_all(&changed);

if (r == 0) {

need_dm_detach = false;

log_info("All DM devices detached.");

} else if (r > 0)

log_info("Not all DM devices detached, %d left.", r);

else

log_error("Failed to detach DM devices: %s", strerror(-r));

}

if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {

if (retries > 0)

log_info("All filesystems, swaps, loop devices, DM devices detached.");

/* Yay, done */

break;

}

/* If in this iteration we didn't manage to

if (!changed) {

log_error("Cannot finalize remaining file systems and devices, giving up.");

break;

}

log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1);

}

if (retries >= FINALIZE_ATTEMPTS)

log_error("Too many iterations, giving up.");

else

log_info("Storage is finalized.");

arguments[0] = NULL;

arguments[1] = argv[1];

arguments[2] = NULL;

execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, arguments);

if (!in_container && !in_initrd() &&

access("/run/initramfs/shutdown", X_OK) == 0) {

if (prepare_new_root() >= 0 &&

pivot_to_new_root() >= 0) {

log_info("Returning to initrd...");

execv("/shutdown", argv);

log_error("Failed to execute shutdown binary: %m");

}

}

/* The kernel will automaticall flush ATA disks and suchlike

if (!in_container)

sync();

if (cmd == LINUX_REBOOT_CMD_KEXEC) {

if (!in_container) {

/* We cheat and exec kexec to avoid doing all its work */

pid_t pid = fork();

if (pid < 0)

log_error("Could not fork: %m. Falling back to normal reboot.");

else if (pid > 0) {

wait_for_terminate_and_warn("kexec", pid);

log_warning("kexec failed. Falling back to normal reboot.");

} else {

/* Child */

const char *args[3] = { "/sbin/kexec", "-e", NULL };

execv(args[0], (char * const *) args);

return EXIT_FAILURE;

}

}

cmd = RB_AUTOBOOT;

}

reboot(cmd);

if (errno == EPERM && in_container) {

/* If we are in a container, and we lacked

log_error("Exiting container.");

exit(0);

}

log_error("Failed to invoke reboot(): %m");

r = -errno;

error:

log_error("Critical error while doing system shutdown: %s", strerror(-r));

freeze();

return EXIT_FAILURE;

}