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 GPL version 2, see file LICENSE in this tarball for details.
   8  */
   9
  10 #include "libbb.h"
  11 #include <sys/reboot.h>
  12
  13 #if ENABLE_FEATURE_WTMP
  14 #include <sys/utsname.h>
  15 #include <utmp.h>
  16
  17 static void write_wtmp(void)
  18 {
  19         struct utmp utmp;
  20         struct utsname uts;
  21         /* "man utmp" says wtmp file should *not* be created automagically */
  22         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
  23                 close(creat(bb_path_wtmp_file, 0664));
  24         }*/
  25         memset(&utmp, 0, sizeof(utmp));
  26         utmp.ut_tv.tv_sec = time(NULL);
  27         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
  28         utmp.ut_type = RUN_LVL;
  29         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
  30         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
  31         uname(&uts);
  32         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
  33         updwtmp(bb_path_wtmp_file, &utmp);
  34 }
  35 #else
  36 #define write_wtmp() ((void)0)
  37 #endif
  38
  39 #ifndef RB_HALT_SYSTEM
  40 #define RB_HALT_SYSTEM RB_HALT
  41 #endif
  42
  43 #ifndef RB_POWERDOWN
  44 /* Stop system and switch power off if possible.  */
  45 # define RB_POWERDOWN   0x4321fedc
  46 #endif
  47 #ifndef RB_POWER_OFF
  48 # define RB_POWER_OFF RB_POWERDOWN
  49 #endif
  50
  51
  52 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  53 int halt_main(int argc UNUSED_PARAM, char **argv)
  54 {
  55         static const int magic[] = {
  56                 RB_HALT_SYSTEM,
  57                 RB_POWER_OFF,
  58                 RB_AUTOBOOT
  59         };
  60         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
  61
  62         int delay = 0;
  63         int which, flags, rc;
  64
  65         /* Figure out which applet we're running */
  66         for (which = 0; "hpr"[which] != applet_name[0]; which++)
  67                 continue;
  68
  69         /* Parse and handle arguments */
  70         opt_complementary = "d+"; /* -d N */
  71         /* We support -w even if !ENABLE_FEATURE_WTMP,
  72          * in order to not break scripts.
  73          * -i (shut down network interfaces) is ignored.
  74          */
  75         flags = getopt32(argv, "d:nfwi", &delay);
  76
  77         sleep(delay);
  78
  79         write_wtmp();
  80
  81         if (flags & 8) /* -w */
  82                 return EXIT_SUCCESS;
  83
  84         if (!(flags & 2)) /* no -n */
  85                 sync();
  86
  87         /* Perform action. */
  88         rc = 1;
  89         if (!(flags & 4)) { /* no -f */
  90 //TODO: I tend to think that signalling linuxrc is wrong
  91 // pity original author didn't comment on it...
  92                 if (ENABLE_FEATURE_INITRD) {
  93                         /* talk to linuxrc */
  94                         /* bbox init/linuxrc assumed */
  95                         pid_t *pidlist = find_pid_by_name("linuxrc");
  96                         if (pidlist[0] > 0)
  97                                 rc = kill(pidlist[0], signals[which]);
  98                         if (ENABLE_FEATURE_CLEAN_UP)
  99                                 free(pidlist);
 100                 }
 101                 if (rc) {
 102                         /* talk to init */
 103                         if (!ENABLE_FEATURE_CALL_TELINIT) {
 104                                 /* bbox init assumed */
 105                                 rc = kill(1, signals[which]);
 106                         } else {
 107                                 /* SysV style init assumed */
 108                                 /* runlevels:
 109                                  * 0 == shutdown
 110                                  * 6 == reboot */
 111                                 rc = execlp(CONFIG_TELINIT_PATH,
 112                                                 CONFIG_TELINIT_PATH,
 113                                                 which == 2 ? "6" : "0",
 114                                                 (char *)NULL
 115                                 );
 116                         }
 117                 }
 118         } else {
 119                 rc = reboot(magic[which]);
 120         }
 121
 122         if (rc)
 123                 bb_perror_nomsg_and_die();
 124         return rc;
 125 }