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