/* vi: set sw=4 ts=4: */
/*
 * Poweroff reboot and halt, oh my.
 *
 * Copyright 2006 by Rob Landley <rob@landley.net>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

//applet:IF_HALT(APPLET(halt, BB_DIR_SBIN, BB_SUID_DROP))
//applet:IF_HALT(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
//applet:IF_HALT(APPLET_ODDNAME(reboot, halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))

//kbuild:lib-$(CONFIG_HALT) += halt.o

//config:config HALT
//config:       bool "poweroff, halt, and reboot"
//config:       default y
//config:       help
//config:         Stop all processes and either halt, reboot, or power off the system.
//config:
//config:config FEATURE_CALL_TELINIT
//config:       bool "Call telinit on shutdown and reboot"
//config:       default y
//config:       depends on HALT && !INIT
//config:       help
//config:         Call an external program (normally telinit) to facilitate
//config:         a switch to a proper runlevel.
//config:
//config:         This option is only available if you selected halt and friends,
//config:         but did not select init.
//config:
//config:config TELINIT_PATH
//config:       string "Path to telinit executable"
//config:       default "/sbin/telinit"
//config:       depends on FEATURE_CALL_TELINIT
//config:       help
//config:         When busybox halt and friends have to call external telinit
//config:         to facilitate proper shutdown, this path is to be used when
//config:         locating telinit executable.

//usage:#define halt_trivial_usage
//usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
//usage:#define halt_full_usage "\n\n"
//usage:       "Halt the system\n"
//usage:     "\n        -d SEC  Delay interval"
//usage:     "\n        -n      Do not sync"
//usage:     "\n        -f      Force (don't go through init)"
//usage:        IF_FEATURE_WTMP(
//usage:     "\n        -w      Only write a wtmp record"
//usage:        )
//usage:
//usage:#define poweroff_trivial_usage
//usage:       "[-d DELAY] [-n] [-f]"
//usage:#define poweroff_full_usage "\n\n"
//usage:       "Halt and shut off power\n"
//usage:     "\n        -d SEC  Delay interval"
//usage:     "\n        -n      Do not sync"
//usage:     "\n        -f      Force (don't go through init)"
//usage:
//usage:#define reboot_trivial_usage
//usage:       "[-d DELAY] [-n] [-f]"
//usage:#define reboot_full_usage "\n\n"
//usage:       "Reboot the system\n"
//usage:     "\n        -d SEC  Delay interval"
//usage:     "\n        -n      Do not sync"
//usage:     "\n        -f      Force (don't go through init)"

#include "libbb.h"
#include "reboot.h"

#if ENABLE_FEATURE_WTMP
#include <sys/utsname.h>

static void write_wtmp(void)
{
        struct utmp utmp;
        struct utsname uts;
        /* "man utmp" says wtmp file should *not* be created automagically */
        /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
                close(creat(bb_path_wtmp_file, 0664));
        }*/
        memset(&utmp, 0, sizeof(utmp));
        utmp.ut_tv.tv_sec = time(NULL);
        strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
        utmp.ut_type = RUN_LVL;
        utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
        utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
        uname(&uts);
        safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
        updwtmp(bb_path_wtmp_file, &utmp);
}
#else
#define write_wtmp() ((void)0)
#endif


int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int halt_main(int argc UNUSED_PARAM, char **argv)
{
        static const int magic[] = {
                RB_HALT_SYSTEM,
                RB_POWER_OFF,
                RB_AUTOBOOT
        };
        static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };

        int delay = 0;
        int which, flags, rc;

        /* Figure out which applet we're running */
        for (which = 0; "hpr"[which] != applet_name[0]; which++)
                continue;

        /* Parse and handle arguments */
        opt_complementary = "d+"; /* -d N */
        /* We support -w even if !ENABLE_FEATURE_WTMP,
         * in order to not break scripts.
         * -i (shut down network interfaces) is ignored.
         */
        flags = getopt32(argv, "d:nfwi", &delay);

        sleep(delay);

        write_wtmp();

        if (flags & 8) /* -w */
                return EXIT_SUCCESS;

        if (!(flags & 2)) /* no -n */
                sync();

        /* Perform action. */
        rc = 1;
        if (!(flags & 4)) { /* no -f */
//TODO: I tend to think that signalling linuxrc is wrong
// pity original author didn't comment on it...
                if (ENABLE_FEATURE_INITRD) {
                        /* talk to linuxrc */
                        /* bbox init/linuxrc assumed */
                        pid_t *pidlist = find_pid_by_name("linuxrc");
                        if (pidlist[0] > 0)
                                rc = kill(pidlist[0], signals[which]);
                        if (ENABLE_FEATURE_CLEAN_UP)
                                free(pidlist);
                }
                if (rc) {
                        /* talk to init */
                        if (!ENABLE_FEATURE_CALL_TELINIT) {
                                /* bbox init assumed */
                                rc = kill(1, signals[which]);
                        } else {
                                /* SysV style init assumed */
                                /* runlevels:
                                 * 0 == shutdown
                                 * 6 == reboot */
                                execlp(CONFIG_TELINIT_PATH,
                                                CONFIG_TELINIT_PATH,
                                                which == 2 ? "6" : "0",
                                                (char *)NULL
                                );
                                bb_perror_msg_and_die("can't execute '%s'",
                                                CONFIG_TELINIT_PATH);
                        }
                }
        } else {
                rc = reboot(magic[which]);
        }

        if (rc)
                bb_perror_nomsg_and_die();
        return rc;
}