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 int preinit;
  23
  24 static void do_reboot(void)
  25 {
  26         LOG("reboot\n");
  27         fflush(stderr);
  28         sync();
  29         sleep(1);
  30         reboot(RB_AUTOBOOT);
  31         while (1)
  32         ;
  33 }
  34
  35 static void signal_shutdown(int signal, siginfo_t *siginfo, void *data)
  36 {
  37         int event = 0;
  38         char *msg = NULL;
  39
  40         if (preinit)
  41                 do_reboot();
  42
  43         switch(signal) {
  44         case SIGTERM:
  45                 event = RB_AUTOBOOT;
  46                 msg = "reboot";
  47                 break;
  48         case SIGUSR1:
  49         case SIGUSR2:
  50                 event = RB_POWER_OFF;
  51                 msg = "poweroff";
  52                 break;
  53         }
  54
  55         DEBUG(1, "Triggering %s\n", msg);
  56         if (event)
  57                 procd_shutdown(event);
  58 }
  59
  60 struct sigaction sa_shutdown = {
  61         .sa_sigaction = signal_shutdown,
  62         .sa_flags = SA_SIGINFO
  63 };
  64
  65 static void signal_crash(int signal, siginfo_t *siginfo, void *data)
  66 {
  67         ERROR("Rebooting as procd has crashed\n");
  68         do_reboot();
  69 }
  70
  71 struct sigaction sa_crash = {
  72         .sa_sigaction = signal_crash,
  73         .sa_flags = SA_SIGINFO
  74 };
  75
  76 static void signal_dummy(int signal, siginfo_t *siginfo, void *data)
  77 {
  78         ERROR("Got unexpected signal %d\n", signal);
  79 }
  80
  81 struct sigaction sa_dummy = {
  82         .sa_sigaction = signal_dummy,
  83         .sa_flags = SA_SIGINFO
  84 };
  85
  86 void procd_signal(void)
  87 {
  88         sigaction(SIGPIPE, &sa_dummy, NULL);
  89         if (getpid() != 1)
  90                 return;
  91         sigaction(SIGTERM, &sa_shutdown, NULL);
  92         sigaction(SIGUSR1, &sa_shutdown, NULL);
  93         sigaction(SIGUSR2, &sa_shutdown, NULL);
  94         sigaction(SIGSEGV, &sa_crash, NULL);
  95         sigaction(SIGBUS, &sa_crash, NULL);
  96         sigaction(SIGHUP, &sa_dummy, NULL);
  97         sigaction(SIGKILL, &sa_dummy, NULL);
  98         sigaction(SIGSTOP, &sa_dummy, NULL);
  99 }
 100
 101 void procd_signal_preinit(void)
 102 {
 103         preinit = 1;
 104         sigaction(SIGTERM, &sa_shutdown, NULL);
 105         sigaction(SIGUSR1, &sa_shutdown, NULL);
 106         sigaction(SIGUSR2, &sa_shutdown, NULL);
 107 }