signal.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <sys/reboot.h>
  16 #include <sys/types.h>
  17
  18 #include <unistd.h>
  19
  20 #include "procd.h"
  21
  22 static void do_reboot(void)
  23 {
  24         LOG("reboot\n");
  25         fflush(stderr);
  26         sync();
  27         sleep(2);
  28         reboot(RB_AUTOBOOT);
  29         while (1)
  30         ;
  31 }
  32
  33 static void signal_shutdown(int signal, siginfo_t *siginfo, void *data)
  34 {
  35         int event = 0;
  36         char *msg = NULL;
  37
  38 #ifndef DISABLE_INIT
  39         switch(signal) {
  40         case SIGINT:
  41         case SIGTERM:
  42                 event = RB_AUTOBOOT;
  43                 msg = "reboot";
  44                 break;
  45         case SIGUSR1:
  46         case SIGUSR2:
  47                 event = RB_POWER_OFF;
  48                 msg = "poweroff";
  49                 break;
  50         }
  51 #endif
  52
  53         DEBUG(1, "Triggering %s\n", msg);
  54         if (event)
  55                 procd_shutdown(event);
  56 }
  57
  58 struct sigaction sa_shutdown = {
  59         .sa_sigaction = signal_shutdown,
  60         .sa_flags = SA_SIGINFO
  61 };
  62
  63 static void signal_crash(int signal, siginfo_t *siginfo, void *data)
  64 {
  65         ERROR("Rebooting as procd has crashed\n");
  66         do_reboot();
  67 }
  68
  69 struct sigaction sa_crash = {
  70         .sa_sigaction = signal_crash,
  71         .sa_flags = SA_SIGINFO
  72 };
  73
  74 static void signal_dummy(int signal, siginfo_t *siginfo, void *data)
  75 {
  76         ERROR("Got unexpected signal %d\n", signal);
  77 }
  78
  79 struct sigaction sa_dummy = {
  80         .sa_sigaction = signal_dummy,
  81         .sa_flags = SA_SIGINFO
  82 };
  83
  84 void procd_signal(void)
  85 {
  86         signal(SIGPIPE, SIG_IGN);
  87         if (getpid() != 1)
  88                 return;
  89         sigaction(SIGTERM, &sa_shutdown, NULL);
  90         sigaction(SIGINT, &sa_shutdown, NULL);
  91         sigaction(SIGUSR1, &sa_shutdown, NULL);
  92         sigaction(SIGUSR2, &sa_shutdown, NULL);
  93         sigaction(SIGSEGV, &sa_crash, NULL);
  94         sigaction(SIGBUS, &sa_crash, NULL);
  95         sigaction(SIGHUP, &sa_dummy, NULL);
  96         sigaction(SIGKILL, &sa_dummy, NULL);
  97         sigaction(SIGSTOP, &sa_dummy, NULL);
  98 #ifndef DISABLE_INIT
  99         reboot(RB_DISABLE_CAD);
 100 #endif
 101 }