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 "container.h"
  24 #include "procd.h"
  25 #include "syslog.h"
  26 #include "plug/hotplug.h"
  27 #include "watchdog.h"
  28 #include "service/service.h"
  29 #include "utils/utils.h"
  30
  31 enum {
  32         STATE_NONE = 0,
  33         STATE_EARLY,
  34         STATE_UBUS,
  35         STATE_INIT,
  36         STATE_RUNNING,
  37         STATE_SHUTDOWN,
  38         STATE_HALT,
  39         __STATE_MAX,
  40 };
  41
  42 static int state = STATE_NONE;
  43 static int reboot_event;
  44
  45 static void set_stdio(const char* tty)
  46 {
  47         if (chdir("/dev") ||
  48             !freopen(tty, "r", stdin) ||
  49             !freopen(tty, "w", stdout) ||
  50             !freopen(tty, "w", stderr) ||
  51             chdir("/"))
  52                 ERROR("failed to set stdio: %m\n");
  53         else
  54                 fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
  55 }
  56
  57 static void set_console(void)
  58 {
  59         const char* tty;
  60         char* split;
  61         char line[ 20 ];
  62         const char* try[] = { "tty0", "console", NULL }; /* Try the most common outputs */
  63         int f, i = 0;
  64
  65         tty = get_cmdline_val("console",line,sizeof(line));
  66         if (tty != NULL) {
  67                 split = strchr(tty, ',');
  68                 if ( split != NULL )
  69                         *split = '\0';
  70         } else {
  71                 // Try a default
  72                 tty=try[i];
  73                 i++;
  74         }
  75
  76         if (chdir("/dev")) {
  77                 ERROR("failed to change dir to /dev: %m\n");
  78                 return;
  79         }
  80         while (tty!=NULL) {
  81                 f = open(tty, O_RDONLY);
  82                 if (f >= 0) {
  83                         close(f);
  84                         break;
  85                 }
  86
  87                 tty=try[i];
  88                 i++;
  89         }
  90         if (chdir("/"))
  91                 ERROR("failed to change dir to /: %m\n");
  92
  93         if (tty != NULL)
  94                 set_stdio(tty);
  95 }
  96
  97 static void perform_halt()
  98 {
  99         if (reboot_event == RB_POWER_OFF)
 100                 LOG("- power down -\n");
 101         else
 102                 LOG("- reboot -\n");
 103
 104         /* Allow time for last message to reach serial console, etc */
 105         sleep(1);
 106
 107         if (is_container()) {
 108                 reboot(reboot_event);
 109                 exit(EXIT_SUCCESS);
 110                 return;
 111         }
 112
 113         /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS)
 114          * in linux/kernel/sys.c, which can cause the machine to panic when
 115          * the init process exits... */
 116         if (!vfork()) { /* child */
 117                 reboot(reboot_event);
 118                 _exit(EXIT_SUCCESS);
 119         }
 120
 121         while (1)
 122                 sleep(1);
 123 }
 124
 125 static void state_enter(void)
 126 {
 127         char ubus_cmd[] = "/sbin/ubusd";
 128
 129         switch (state) {
 130         case STATE_EARLY:
 131                 LOG("- early -\n");
 132                 watchdog_init(0);
 133                 hotplug("/etc/hotplug.json");
 134                 procd_coldplug();
 135                 break;
 136
 137         case STATE_UBUS:
 138                 // try to reopen incase the wdt was not available before coldplug
 139                 watchdog_init(0);
 140                 set_stdio("console");
 141                 LOG("- ubus -\n");
 142                 procd_connect_ubus();
 143                 service_start_early("ubus", ubus_cmd);
 144                 break;
 145
 146         case STATE_INIT:
 147                 LOG("- init -\n");
 148                 procd_inittab();
 149                 procd_inittab_run("respawn");
 150                 procd_inittab_run("askconsole");
 151                 procd_inittab_run("askfirst");
 152                 procd_inittab_run("sysinit");
 153
 154                 // switch to syslog log channel
 155                 ulog_open(ULOG_SYSLOG, LOG_DAEMON, "procd");
 156                 break;
 157
 158         case STATE_RUNNING:
 159                 LOG("- init complete -\n");
 160                 procd_inittab_run("respawnlate");
 161                 procd_inittab_run("askconsolelate");
 162                 break;
 163
 164         case STATE_SHUTDOWN:
 165                 /* Redirect output to the console for the users' benefit */
 166                 set_console();
 167                 LOG("- shutdown -\n");
 168                 procd_inittab_run("shutdown");
 169                 sync();
 170                 break;
 171
 172         case STATE_HALT:
 173                 // To prevent killed processes from interrupting the sleep
 174                 signal(SIGCHLD, SIG_IGN);
 175                 LOG("- SIGTERM processes -\n");
 176                 kill(-1, SIGTERM);
 177                 sync();
 178                 sleep(1);
 179                 LOG("- SIGKILL processes -\n");
 180                 kill(-1, SIGKILL);
 181                 sync();
 182                 sleep(1);
 183 #ifndef DISABLE_INIT
 184                 perform_halt();
 185 #else
 186                 exit(EXIT_SUCCESS);
 187 #endif
 188                 break;
 189
 190         default:
 191                 ERROR("Unhandled state %d\n", state);
 192                 return;
 193         };
 194 }
 195
 196 void procd_state_next(void)
 197 {
 198         DEBUG(4, "Change state %d -> %d\n", state, state + 1);
 199         state++;
 200         state_enter();
 201 }
 202
 203 void procd_state_ubus_connect(void)
 204 {
 205         if (state == STATE_UBUS)
 206                 procd_state_next();
 207 }
 208
 209 void procd_shutdown(int event)
 210 {
 211         if (state >= STATE_SHUTDOWN)
 212                 return;
 213         DEBUG(2, "Shutting down system with event %x\n", event);
 214         reboot_event = event;
 215         state = STATE_SHUTDOWN;
 216         state_enter();
 217 }