init/halt.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Poweroff reboot and halt, oh my.
   4  *
   5  * Copyright 2006 by Rob Landley <rob@landley.net>
   6  *
   7  * Licensed under GPLv2, see file LICENSE in this source tree.
   8  */
   9
  10 //applet:IF_HALT(APPLET(halt, _BB_DIR_SBIN, _BB_SUID_DROP))
  11 //applet:IF_HALT(APPLET_ODDNAME(poweroff, halt, _BB_DIR_SBIN, _BB_SUID_DROP, poweroff))
  12 //applet:IF_HALT(APPLET_ODDNAME(reboot, halt, _BB_DIR_SBIN, _BB_SUID_DROP, reboot))
  13
  14 //kbuild:lib-$(CONFIG_HALT) += halt.o
  15
  16 //config:config HALT
  17 //config:       bool "poweroff, halt, and reboot"
  18 //config:       default y
  19 //config:       help
  20 //config:         Stop all processes and either halt, reboot, or power off the system.
  21 //config:
  22 //config:config FEATURE_CALL_TELINIT
  23 //config:       bool "Call telinit on shutdown and reboot"
  24 //config:       default y
  25 //config:       depends on HALT && !INIT
  26 //config:       help
  27 //config:         Call an external program (normally telinit) to facilitate
  28 //config:         a switch to a proper runlevel.
  29 //config:
  30 //config:         This option is only available if you selected halt and friends,
  31 //config:         but did not select init.
  32 //config:
  33 //config:config TELINIT_PATH
  34 //config:       string "Path to telinit executable"
  35 //config:       default "/sbin/telinit"
  36 //config:       depends on FEATURE_CALL_TELINIT
  37 //config:       help
  38 //config:         When busybox halt and friends have to call external telinit
  39 //config:         to facilitate proper shutdown, this path is to be used when
  40 //config:         locating telinit executable.
  41
  42 //usage:#define halt_trivial_usage
  43 //usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
  44 //usage:#define halt_full_usage "\n\n"
  45 //usage:       "Halt the system\n"
  46 //usage:     "\nOptions:"
  47 //usage:     "\n        -d SEC  Delay interval"
  48 //usage:     "\n        -n      Do not sync"
  49 //usage:     "\n        -f      Force (don't go through init)"
  50 //usage:        IF_FEATURE_WTMP(
  51 //usage:     "\n        -w      Only write a wtmp record"
  52 //usage:        )
  53 //usage:
  54 //usage:#define poweroff_trivial_usage
  55 //usage:       "[-d DELAY] [-n] [-f]"
  56 //usage:#define poweroff_full_usage "\n\n"
  57 //usage:       "Halt and shut off power\n"
  58 //usage:     "\nOptions:"
  59 //usage:     "\n        -d SEC  Delay interval"
  60 //usage:     "\n        -n      Do not sync"
  61 //usage:     "\n        -f      Force (don't go through init)"
  62 //usage:
  63 //usage:#define reboot_trivial_usage
  64 //usage:       "[-d DELAY] [-n] [-f]"
  65 //usage:#define reboot_full_usage "\n\n"
  66 //usage:       "Reboot the system\n"
  67 //usage:     "\nOptions:"
  68 //usage:     "\n        -d SEC  Delay interval"
  69 //usage:     "\n        -n      Do not sync"
  70 //usage:     "\n        -f      Force (don't go through init)"
  71
  72 #include "libbb.h"
  73 #include "reboot.h"
  74
  75 #if ENABLE_FEATURE_WTMP
  76 #include <sys/utsname.h>
  77 #include <utmp.h>
  78
  79 static void write_wtmp(void)
  80 {
  81         struct utmp utmp;
  82         struct utsname uts;
  83         /* "man utmp" says wtmp file should *not* be created automagically */
  84         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
  85                 close(creat(bb_path_wtmp_file, 0664));
  86         }*/
  87         memset(&utmp, 0, sizeof(utmp));
  88         utmp.ut_tv.tv_sec = time(NULL);
  89         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
  90         utmp.ut_type = RUN_LVL;
  91         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
  92         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
  93         uname(&uts);
  94         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
  95         updwtmp(bb_path_wtmp_file, &utmp);
  96 }
  97 #else
  98 #define write_wtmp() ((void)0)
  99 #endif
 100
 101
 102 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 103 int halt_main(int argc UNUSED_PARAM, char **argv)
 104 {
 105         static const int magic[] = {
 106                 RB_HALT_SYSTEM,
 107                 RB_POWER_OFF,
 108                 RB_AUTOBOOT
 109         };
 110         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
 111
 112         int delay = 0;
 113         int which, flags, rc;
 114
 115         /* Figure out which applet we're running */
 116         for (which = 0; "hpr"[which] != applet_name[0]; which++)
 117                 continue;
 118
 119         /* Parse and handle arguments */
 120         opt_complementary = "d+"; /* -d N */
 121         /* We support -w even if !ENABLE_FEATURE_WTMP,
 122          * in order to not break scripts.
 123          * -i (shut down network interfaces) is ignored.
 124          */
 125         flags = getopt32(argv, "d:nfwi", &delay);
 126
 127         sleep(delay);
 128
 129         write_wtmp();
 130
 131         if (flags & 8) /* -w */
 132                 return EXIT_SUCCESS;
 133
 134         if (!(flags & 2)) /* no -n */
 135                 sync();
 136
 137         /* Perform action. */
 138         rc = 1;
 139         if (!(flags & 4)) { /* no -f */
 140 //TODO: I tend to think that signalling linuxrc is wrong
 141 // pity original author didn't comment on it...
 142                 if (ENABLE_FEATURE_INITRD) {
 143                         /* talk to linuxrc */
 144                         /* bbox init/linuxrc assumed */
 145                         pid_t *pidlist = find_pid_by_name("linuxrc");
 146                         if (pidlist[0] > 0)
 147                                 rc = kill(pidlist[0], signals[which]);
 148                         if (ENABLE_FEATURE_CLEAN_UP)
 149                                 free(pidlist);
 150                 }
 151                 if (rc) {
 152                         /* talk to init */
 153                         if (!ENABLE_FEATURE_CALL_TELINIT) {
 154                                 /* bbox init assumed */
 155                                 rc = kill(1, signals[which]);
 156                         } else {
 157                                 /* SysV style init assumed */
 158                                 /* runlevels:
 159                                  * 0 == shutdown
 160                                  * 6 == reboot */
 161                                 rc = execlp(CONFIG_TELINIT_PATH,
 162                                                 CONFIG_TELINIT_PATH,
 163                                                 which == 2 ? "6" : "0",
 164                                                 (char *)NULL
 165                                 );
 166                         }
 167                 }
 168         } else {
 169                 rc = reboot(magic[which]);
 170         }
 171
 172         if (rc)
 173                 bb_perror_nomsg_and_die();
 174         return rc;
 175 }