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