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