state.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 <fcntl.h>
  16 #include <sys/reboot.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <unistd.h>
  20 #include <sys/types.h>
  21 #include <signal.h>
  22
  23 #include "procd.h"
  24 #include "syslog.h"
  25 #include "plug/hotplug.h"
  26 #include "watchdog.h"
  27 #include "service/service.h"
  28 #include "utils/utils.h"
  29
  30 enum {
  31         STATE_NONE = 0,
  32         STATE_EARLY,
  33         STATE_UBUS,
  34         STATE_INIT,
  35         STATE_RUNNING,
  36         STATE_SHUTDOWN,
  37         STATE_HALT,
  38         __STATE_MAX,
  39 };
  40
  41 static int state = STATE_NONE;
  42 static int reboot_event;
  43
  44 static void set_stdio(const char* tty)
  45 {
  46         if (chdir("/dev") ||
  47             !freopen(tty, "r", stdin) ||
  48             !freopen(tty, "w", stdout) ||
  49             !freopen(tty, "w", stderr) ||
  50             chdir("/"))
  51                 ERROR("failed to set stdio\n");
  52         else
  53                 fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
  54 }
  55
  56 static void set_console(void)
  57 {
  58         const char* tty;
  59         char* split;
  60         char line[ 20 ];
  61         const char* try[] = { "tty0", "console", NULL }; /* Try the most common outputs */
  62         int f, i = 0;
  63
  64         tty = get_cmdline_val("console",line,sizeof(line));
  65         if (tty != NULL) {
  66                 split = strchr(tty, ',');
  67                 if ( split != NULL )
  68                         *split = '\0';
  69         } else {
  70                 // Try a default
  71                 tty=try[i];
  72                 i++;
  73         }
  74
  75         if (chdir("/dev")) {
  76                 ERROR("failed to change dir to /dev\n");
  77                 return;
  78         }
  79         while (tty!=NULL) {
  80                 f = open(tty, O_RDONLY);
  81                 if (f >= 0) {
  82                         close(f);
  83                         break;
  84                 }
  85
  86                 tty=try[i];
  87                 i++;
  88         }
  89         if (chdir("/"))
  90                 ERROR("failed to change dir to /\n");
  91
  92         if (tty != NULL)
  93                 set_stdio(tty);
  94 }
  95
  96 static void state_enter(void)
  97 {
  98         char ubus_cmd[] = "/sbin/ubusd";
  99
 100         switch (state) {
 101         case STATE_EARLY:
 102                 LOG("- early -\n");
 103                 watchdog_init(0);
 104                 hotplug("/etc/hotplug.json");
 105                 procd_coldplug();
 106                 break;
 107
 108         case STATE_UBUS:
 109                 // try to reopen incase the wdt was not available before coldplug
 110                 watchdog_init(0);
 111                 set_stdio("console");
 112                 LOG("- ubus -\n");
 113                 procd_connect_ubus();
 114                 service_start_early("ubus", ubus_cmd);
 115                 break;
 116
 117         case STATE_INIT:
 118                 LOG("- init -\n");
 119                 procd_inittab();
 120                 procd_inittab_run("respawn");
 121                 procd_inittab_run("askconsole");
 122                 procd_inittab_run("askfirst");
 123                 procd_inittab_run("sysinit");
 124
 125                 // switch to syslog log channel
 126                 ulog_open(ULOG_SYSLOG, LOG_DAEMON, "procd");
 127                 break;
 128
 129         case STATE_RUNNING:
 130                 LOG("- init complete -\n");
 131                 break;
 132
 133         case STATE_SHUTDOWN:
 134                 /* Redirect output to the console for the users' benefit */
 135                 set_console();
 136                 LOG("- shutdown -\n");
 137                 procd_inittab_run("shutdown");
 138                 sync();
 139                 break;
 140
 141         case STATE_HALT:
 142                 // To prevent killed processes from interrupting the sleep
 143                 signal(SIGCHLD, SIG_IGN);
 144                 LOG("- SIGTERM processes -\n");
 145                 kill(-1, SIGTERM);
 146                 sync();
 147                 sleep(1);
 148                 LOG("- SIGKILL processes -\n");
 149                 kill(-1, SIGKILL);
 150                 sync();
 151                 sleep(1);
 152 #ifndef DISABLE_INIT
 153                 if (reboot_event == RB_POWER_OFF)
 154                         LOG("- power down -\n");
 155                 else
 156                         LOG("- reboot -\n");
 157
 158                 /* Allow time for last message to reach serial console, etc */
 159                 sleep(1);
 160
 161                 /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS)
 162                  * in linux/kernel/sys.c, which can cause the machine to panic when
 163                  * the init process exits... */
 164                 if (!vfork( )) { /* child */
 165                         reboot(reboot_event);
 166                         _exit(EXIT_SUCCESS);
 167                 }
 168                 while (1)
 169                         sleep(1);
 170 #else
 171                 exit(0);
 172 #endif
 173                 break;
 174
 175         default:
 176                 ERROR("Unhandled state %d\n", state);
 177                 return;
 178         };
 179 }
 180
 181 void procd_state_next(void)
 182 {
 183         DEBUG(4, "Change state %d -> %d\n", state, state + 1);
 184         state++;
 185         state_enter();
 186 }
 187
 188 void procd_state_ubus_connect(void)
 189 {
 190         if (state == STATE_UBUS)
 191                 procd_state_next();
 192 }
 193
 194 void procd_shutdown(int event)
 195 {
 196         if (state >= STATE_SHUTDOWN)
 197                 return;
 198         DEBUG(2, "Shutting down system with event %x\n", event);
 199         reboot_event = event;
 200         state = STATE_SHUTDOWN;
 201         state_enter();
 202 }