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 //config:config HALT
  11 //config:       bool "halt (3.7 kb)"
  12 //config:       default y
  13 //config:       help
  14 //config:       Stop all processes and halt the system.
  15 //config:
  16 //config:config POWEROFF
  17 //config:       bool "poweroff (3.7 kb)"
  18 //config:       default y
  19 //config:       help
  20 //config:       Stop all processes and power off the system.
  21 //config:
  22 //config:config REBOOT
  23 //config:       bool "reboot (3.7 kb)"
  24 //config:       default y
  25 //config:       help
  26 //config:       Stop all processes and reboot the system.
  27 //config:
  28 //config:config FEATURE_CALL_TELINIT
  29 //config:       bool "Call telinit on shutdown and reboot"
  30 //config:       default y
  31 //config:       depends on (HALT || POWEROFF || REBOOT) && !INIT
  32 //config:       help
  33 //config:       Call an external program (normally telinit) to facilitate
  34 //config:       a switch to a proper runlevel.
  35 //config:
  36 //config:       This option is only available if you selected halt and friends,
  37 //config:       but did not select init.
  38 //config:
  39 //config:config TELINIT_PATH
  40 //config:       string "Path to telinit executable"
  41 //config:       default "/sbin/telinit"
  42 //config:       depends on FEATURE_CALL_TELINIT
  43 //config:       help
  44 //config:       When busybox halt and friends have to call external telinit
  45 //config:       to facilitate proper shutdown, this path is to be used when
  46 //config:       locating telinit executable.
  47
  48 //applet:IF_HALT(APPLET(halt, BB_DIR_SBIN, BB_SUID_DROP))
  49 //                   APPLET_ODDNAME:name      main  location     suid_type     help
  50 //applet:IF_POWEROFF(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
  51 //applet:IF_REBOOT(  APPLET_ODDNAME(reboot,   halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))
  52
  53 //kbuild:lib-$(CONFIG_HALT) += halt.o
  54 //kbuild:lib-$(CONFIG_POWEROFF) += halt.o
  55 //kbuild:lib-$(CONFIG_REBOOT) += halt.o
  56
  57 //usage:#define halt_trivial_usage
  58 //usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
  59 //usage:#define halt_full_usage "\n\n"
  60 //usage:       "Halt the system\n"
  61 //usage:     "\n        -d SEC  Delay interval"
  62 //usage:     "\n        -n      Do not sync"
  63 //usage:     "\n        -f      Force (don't go through init)"
  64 //usage:        IF_FEATURE_WTMP(
  65 //usage:     "\n        -w      Only write a wtmp record"
  66 //usage:        )
  67 //usage:
  68 //usage:#define poweroff_trivial_usage
  69 //usage:       "[-d DELAY] [-n] [-f]"
  70 //usage:#define poweroff_full_usage "\n\n"
  71 //usage:       "Halt and shut off power\n"
  72 //usage:     "\n        -d SEC  Delay interval"
  73 //usage:     "\n        -n      Do not sync"
  74 //usage:     "\n        -f      Force (don't go through init)"
  75 //usage:
  76 //usage:#define reboot_trivial_usage
  77 //usage:       "[-d DELAY] [-n] [-f]"
  78 //usage:#define reboot_full_usage "\n\n"
  79 //usage:       "Reboot the system\n"
  80 //usage:     "\n        -d SEC  Delay interval"
  81 //usage:     "\n        -n      Do not sync"
  82 //usage:     "\n        -f      Force (don't go through init)"
  83
  84 #include "libbb.h"
  85 #include "reboot.h"
  86
  87 #if ENABLE_FEATURE_WTMP
  88 #include <sys/utsname.h>
  89
  90 static void write_wtmp(void)
  91 {
  92         struct utmpx utmp;
  93         struct utsname uts;
  94         /* "man utmp" says wtmp file should *not* be created automagically */
  95         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
  96                 close(creat(bb_path_wtmp_file, 0664));
  97         }*/
  98         memset(&utmp, 0, sizeof(utmp));
  99         utmp.ut_tv.tv_sec = time(NULL);
 100         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
 101         utmp.ut_type = RUN_LVL;
 102         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
 103         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
 104         uname(&uts);
 105         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
 106         updwtmpx(bb_path_wtmp_file, &utmp);
 107 }
 108 #else
 109 #define write_wtmp() ((void)0)
 110 #endif
 111
 112
 113 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 114 int halt_main(int argc UNUSED_PARAM, char **argv)
 115 {
 116         static const int magic[] = {
 117                 RB_HALT_SYSTEM,
 118                 RB_POWER_OFF,
 119                 RB_AUTOBOOT
 120         };
 121         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
 122
 123         int delay = 0;
 124         int which, flags, rc;
 125
 126         /* Figure out which applet we're running */
 127         if (ENABLE_HALT && !ENABLE_POWEROFF && !ENABLE_REBOOT)
 128                 which = 0;
 129         else
 130         if (!ENABLE_HALT && ENABLE_POWEROFF && !ENABLE_REBOOT)
 131                 which = 1;
 132         else
 133         if (!ENABLE_HALT && !ENABLE_POWEROFF && ENABLE_REBOOT)
 134                 which = 2;
 135         else
 136         for (which = 0; "hpr"[which] != applet_name[0]; which++)
 137                 continue;
 138
 139         /* Parse and handle arguments */
 140         /* We support -w even if !ENABLE_FEATURE_WTMP,
 141          * in order to not break scripts.
 142          * -i (shut down network interfaces) is ignored.
 143          */
 144         flags = getopt32(argv, "d:+nfwi", &delay);
 145
 146         sleep(delay);
 147
 148         write_wtmp();
 149
 150         if (flags & 8) /* -w */
 151                 return EXIT_SUCCESS;
 152
 153         if (!(flags & 2)) /* no -n */
 154                 sync();
 155
 156         /* Perform action. */
 157         rc = 1;
 158         if (!(flags & 4)) { /* no -f */
 159 //TODO: I tend to think that signalling linuxrc is wrong
 160 // pity original author didn't comment on it...
 161                 if (ENABLE_LINUXRC) {
 162                         /* talk to linuxrc */
 163                         /* bbox init/linuxrc assumed */
 164                         pid_t *pidlist = find_pid_by_name("linuxrc");
 165                         if (pidlist[0] > 0)
 166                                 rc = kill(pidlist[0], signals[which]);
 167                         if (ENABLE_FEATURE_CLEAN_UP)
 168                                 free(pidlist);
 169                 }
 170                 if (rc) {
 171                         /* talk to init */
 172                         if (!ENABLE_FEATURE_CALL_TELINIT) {
 173                                 /* bbox init assumed */
 174                                 rc = kill(1, signals[which]);
 175                         } else {
 176                                 /* SysV style init assumed */
 177                                 /* runlevels:
 178                                  * 0 == shutdown
 179                                  * 6 == reboot */
 180                                 execlp(CONFIG_TELINIT_PATH,
 181                                                 CONFIG_TELINIT_PATH,
 182                                                 which == 2 ? "6" : "0",
 183                                                 (char *)NULL
 184                                 );
 185                                 bb_perror_msg_and_die("can't execute '%s'",
 186                                                 CONFIG_TELINIT_PATH);
 187                         }
 188                 }
 189         } else {
 190                 rc = reboot(magic[which]);
 191         }
 192
 193         if (rc)
 194                 bb_perror_nomsg_and_die();
 195         return rc;
 196 }