busybox/init/halt.c
Denys Vlasenko 205d48e948 *: add comment about APPLET_ODDNAME format
It confused me more than once

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-01-29 14:57:33 +01:00

197 lines
5.4 KiB
C

/* 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.
*/
//config:config HALT
//config: bool "halt"
//config: default y
//config: help
//config: Stop all processes and halt the system.
//config:
//config:config POWEROFF
//config: bool "poweroff"
//config: default y
//config: help
//config: Stop all processes and power off the system.
//config:
//config:config REBOOT
//config: bool "reboot"
//config: default y
//config: help
//config: Stop all processes and reboot the system.
//config:
//config:config FEATURE_CALL_TELINIT
//config: bool "Call telinit on shutdown and reboot"
//config: default y
//config: depends on (HALT || POWEROFF || REBOOT) && !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.
//applet:IF_HALT(APPLET(halt, BB_DIR_SBIN, BB_SUID_DROP))
// APPLET_ODDNAME:name main location suid_type help
//applet:IF_POWEROFF(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
//applet:IF_REBOOT( APPLET_ODDNAME(reboot, halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))
//kbuild:lib-$(CONFIG_HALT) += halt.o
//kbuild:lib-$(CONFIG_POWEROFF) += halt.o
//kbuild:lib-$(CONFIG_REBOOT) += halt.o
//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 utmpx 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));
updwtmpx(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 */
if (ENABLE_HALT && !ENABLE_POWEROFF && !ENABLE_REBOOT)
which = 0;
else
if (!ENABLE_HALT && ENABLE_POWEROFF && !ENABLE_REBOOT)
which = 1;
else
if (!ENABLE_HALT && !ENABLE_POWEROFF && ENABLE_REBOOT)
which = 2;
else
for (which = 0; "hpr"[which] != applet_name[0]; which++)
continue;
/* Parse and handle arguments */
/* 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_LINUXRC) {
/* 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;
}