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 #include "libbb.h"
  11 #include "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
  40 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  41 int halt_main(int argc UNUSED_PARAM, char **argv)
  42 {
  43         static const int magic[] = {
  44                 RB_HALT_SYSTEM,
  45                 RB_POWER_OFF,
  46                 RB_AUTOBOOT
  47         };
  48         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
  49
  50         int delay = 0;
  51         int which, flags, rc;
  52
  53         /* Figure out which applet we're running */
  54         for (which = 0; "hpr"[which] != applet_name[0]; which++)
  55                 continue;
  56
  57         /* Parse and handle arguments */
  58         opt_complementary = "d+"; /* -d N */
  59         /* We support -w even if !ENABLE_FEATURE_WTMP,
  60          * in order to not break scripts.
  61          * -i (shut down network interfaces) is ignored.
  62          */
  63         flags = getopt32(argv, "d:nfwi", &delay);
  64
  65         sleep(delay);
  66
  67         write_wtmp();
  68
  69         if (flags & 8) /* -w */
  70                 return EXIT_SUCCESS;
  71
  72         if (!(flags & 2)) /* no -n */
  73                 sync();
  74
  75         /* Perform action. */
  76         rc = 1;
  77         if (!(flags & 4)) { /* no -f */
  78 //TODO: I tend to think that signalling linuxrc is wrong
  79 // pity original author didn't comment on it...
  80                 if (ENABLE_FEATURE_INITRD) {
  81                         /* talk to linuxrc */
  82                         /* bbox init/linuxrc assumed */
  83                         pid_t *pidlist = find_pid_by_name("linuxrc");
  84                         if (pidlist[0] > 0)
  85                                 rc = kill(pidlist[0], signals[which]);
  86                         if (ENABLE_FEATURE_CLEAN_UP)
  87                                 free(pidlist);
  88                 }
  89                 if (rc) {
  90                         /* talk to init */
  91                         if (!ENABLE_FEATURE_CALL_TELINIT) {
  92                                 /* bbox init assumed */
  93                                 rc = kill(1, signals[which]);
  94                         } else {
  95                                 /* SysV style init assumed */
  96                                 /* runlevels:
  97                                  * 0 == shutdown
  98                                  * 6 == reboot */
  99                                 rc = execlp(CONFIG_TELINIT_PATH,
 100                                                 CONFIG_TELINIT_PATH,
 101                                                 which == 2 ? "6" : "0",
 102                                                 (char *)NULL
 103                                 );
 104                         }
 105                 }
 106         } else {
 107                 rc = reboot(magic[which]);
 108         }
 109
 110         if (rc)
 111                 bb_perror_nomsg_and_die();
 112         return rc;
 113 }