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         switch(signal) {
  39         case SIGTERM:
  40                 event = RB_AUTOBOOT;
  41                 msg = "reboot";
  42                 break;
  43         case SIGUSR1:
  44         case SIGUSR2:
  45                 event = RB_POWER_OFF;
  46                 msg = "poweroff";
  47                 break;
  48         }
  49
  50         DEBUG(1, "Triggering %s\n", msg);
  51         if (event)
  52                 procd_shutdown(event);
  53 }
  54
  55 struct sigaction sa_shutdown = {
  56         .sa_sigaction = signal_shutdown,
  57         .sa_flags = SA_SIGINFO
  58 };
  59
  60 static void signal_crash(int signal, siginfo_t *siginfo, void *data)
  61 {
  62         ERROR("Rebooting as procd has crashed\n");
  63         do_reboot();
  64 }
  65
  66 struct sigaction sa_crash = {
  67         .sa_sigaction = signal_crash,
  68         .sa_flags = SA_SIGINFO
  69 };
  70
  71 static void signal_dummy(int signal, siginfo_t *siginfo, void *data)
  72 {
  73         ERROR("Got unexpected signal %d\n", signal);
  74 }
  75
  76 struct sigaction sa_dummy = {
  77         .sa_sigaction = signal_dummy,
  78         .sa_flags = SA_SIGINFO
  79 };
  80
  81 void procd_signal(void)
  82 {
  83         signal(SIGPIPE, SIG_IGN);
  84         if (getpid() != 1)
  85                 return;
  86         sigaction(SIGTERM, &sa_shutdown, NULL);
  87         sigaction(SIGUSR1, &sa_shutdown, NULL);
  88         sigaction(SIGUSR2, &sa_shutdown, NULL);
  89         sigaction(SIGSEGV, &sa_crash, NULL);
  90         sigaction(SIGBUS, &sa_crash, NULL);
  91         sigaction(SIGHUP, &sa_dummy, NULL);
  92         sigaction(SIGKILL, &sa_dummy, NULL);
  93         sigaction(SIGSTOP, &sa_dummy, NULL);
  94 }