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"
  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"
  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"
  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:IF_POWEROFF(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
  50 //applet:IF_REBOOT(APPLET_ODDNAME(reboot, halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))
  51
  52 //kbuild:lib-$(CONFIG_HALT) += halt.o
  53 //kbuild:lib-$(CONFIG_POWEROFF) += halt.o
  54 //kbuild:lib-$(CONFIG_REBOOT) += halt.o
  55
  56 //usage:#define halt_trivial_usage
  57 //usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
  58 //usage:#define halt_full_usage "\n\n"
  59 //usage:       "Halt the system\n"
  60 //usage:     "\n        -d SEC  Delay interval"
  61 //usage:     "\n        -n      Do not sync"
  62 //usage:     "\n        -f      Force (don't go through init)"
  63 //usage:        IF_FEATURE_WTMP(
  64 //usage:     "\n        -w      Only write a wtmp record"
  65 //usage:        )
  66 //usage:
  67 //usage:#define poweroff_trivial_usage
  68 //usage:       "[-d DELAY] [-n] [-f]"
  69 //usage:#define poweroff_full_usage "\n\n"
  70 //usage:       "Halt and shut off power\n"
  71 //usage:     "\n        -d SEC  Delay interval"
  72 //usage:     "\n        -n      Do not sync"
  73 //usage:     "\n        -f      Force (don't go through init)"
  74 //usage:
  75 //usage:#define reboot_trivial_usage
  76 //usage:       "[-d DELAY] [-n] [-f]"
  77 //usage:#define reboot_full_usage "\n\n"
  78 //usage:       "Reboot the system\n"
  79 //usage:     "\n        -d SEC  Delay interval"
  80 //usage:     "\n        -n      Do not sync"
  81 //usage:     "\n        -f      Force (don't go through init)"
  82
  83 #include "libbb.h"
  84 #include "reboot.h"
  85
  86 #if ENABLE_FEATURE_WTMP
  87 #include <sys/utsname.h>
  88
  89 static void write_wtmp(void)
  90 {
  91         struct utmpx utmp;
  92         struct utsname uts;
  93         /* "man utmp" says wtmp file should *not* be created automagically */
  94         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
  95                 close(creat(bb_path_wtmp_file, 0664));
  96         }*/
  97         memset(&utmp, 0, sizeof(utmp));
  98         utmp.ut_tv.tv_sec = time(NULL);
  99         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
 100         utmp.ut_type = RUN_LVL;
 101         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
 102         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
 103         uname(&uts);
 104         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
 105         updwtmpx(bb_path_wtmp_file, &utmp);
 106 }
 107 #else
 108 #define write_wtmp() ((void)0)
 109 #endif
 110
 111
 112 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 113 int halt_main(int argc UNUSED_PARAM, char **argv)
 114 {
 115         static const int magic[] = {
 116                 RB_HALT_SYSTEM,
 117                 RB_POWER_OFF,
 118                 RB_AUTOBOOT
 119         };
 120         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
 121
 122         int delay = 0;
 123         int which, flags, rc;
 124
 125         /* Figure out which applet we're running */
 126         if (ENABLE_HALT && !ENABLE_POWEROFF && !ENABLE_REBOOT)
 127                 which = 0;
 128         else
 129         if (!ENABLE_HALT && ENABLE_POWEROFF && !ENABLE_REBOOT)
 130                 which = 1;
 131         else
 132         if (!ENABLE_HALT && !ENABLE_POWEROFF && ENABLE_REBOOT)
 133                 which = 2;
 134         else
 135         for (which = 0; "hpr"[which] != applet_name[0]; which++)
 136                 continue;
 137
 138         /* Parse and handle arguments */
 139         /* We support -w even if !ENABLE_FEATURE_WTMP,
 140          * in order to not break scripts.
 141          * -i (shut down network interfaces) is ignored.
 142          */
 143         flags = getopt32(argv, "d:+nfwi", &delay);
 144
 145         sleep(delay);
 146
 147         write_wtmp();
 148
 149         if (flags & 8) /* -w */
 150                 return EXIT_SUCCESS;
 151
 152         if (!(flags & 2)) /* no -n */
 153                 sync();
 154
 155         /* Perform action. */
 156         rc = 1;
 157         if (!(flags & 4)) { /* no -f */
 158 //TODO: I tend to think that signalling linuxrc is wrong
 159 // pity original author didn't comment on it...
 160                 if (ENABLE_LINUXRC) {
 161                         /* talk to linuxrc */
 162                         /* bbox init/linuxrc assumed */
 163                         pid_t *pidlist = find_pid_by_name("linuxrc");
 164                         if (pidlist[0] > 0)
 165                                 rc = kill(pidlist[0], signals[which]);
 166                         if (ENABLE_FEATURE_CLEAN_UP)
 167                                 free(pidlist);
 168                 }
 169                 if (rc) {
 170                         /* talk to init */
 171                         if (!ENABLE_FEATURE_CALL_TELINIT) {
 172                                 /* bbox init assumed */
 173                                 rc = kill(1, signals[which]);
 174                         } else {
 175                                 /* SysV style init assumed */
 176                                 /* runlevels:
 177                                  * 0 == shutdown
 178                                  * 6 == reboot */
 179                                 execlp(CONFIG_TELINIT_PATH,
 180                                                 CONFIG_TELINIT_PATH,
 181                                                 which == 2 ? "6" : "0",
 182                                                 (char *)NULL
 183                                 );
 184                                 bb_perror_msg_and_die("can't execute '%s'",
 185                                                 CONFIG_TELINIT_PATH);
 186                         }
 187                 }
 188         } else {
 189                 rc = reboot(magic[which]);
 190         }
 191
 192         if (rc)
 193                 bb_perror_nomsg_and_die();
 194         return rc;
 195 }