text: /* Optional /dev/initctl FIFO monitor, for receiving commands from telinit
   *
   * Copyright (c) 2008-2010  Claudio Matsuoka <cmatsuoka@gmail.com>
   * Copyright (c) 2008-2015  Joachim Nilsson <troglobit@gmail.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include "config.h"		/* Generated by configure script */
  
  #include <errno.h>
  #include <fcntl.h>		/* O_RDONLY et al */
  #include <signal.h>
  #include <string.h>
  #include <unistd.h>		/* read() */
  #include <sys/stat.h>
  #include <lite/lite.h>
  
  #include "finit.h"
  #include "conf.h"
  #include "helpers.h"
  #include "plugin.h"
  #include "sig.h"
  #include "service.h"
  
  static void parse(void *arg, int fd, int events);
  static void setup(void *arg);
  
  static plugin_t plugin = {
  	.name = __FILE__,
  	.io = {
  		.cb    = parse,
  		.flags = PLUGIN_IO_READ,
  	},
  	.hook[HOOK_BASEFS_UP] = {
  		.cb    = setup
  	},
  	.depends = { "bootmisc", },
  };
  
  static void fifo_open(void)
  {
  	plugin.io.fd = open(FINIT_FIFO, O_RDWR | O_NONBLOCK | O_CLOEXEC);
  	if (-1 == plugin.io.fd) {
  		_e("Failed opening %s FIFO, error %d: %s", FINIT_FIFO, errno, strerror(errno));
  		return;
  	}
  }
  
  /*
   * We only handle INIT_HALT for differentiating between halt/poweroff
   */
  static void set_env(char *data)
  {
  	const char *var = "INIT_HALT";
  
  	if (strncmp(data, var, strlen(var)))
  		return;
  	data += strlen(var);
  
  	/*
  	 * No value means unset env, in this case cancel shutdown.
  	 */
  	if (data[0] == 0) {
  		halt = SHUT_DEFAULT;
  		/* XXX: Cancel timer here, when we get support for timed shutdown */
  		return;
  	}
  
  	if (string_match(data, "=POWERDOWN"))
  		halt = SHUT_OFF;
  	if (string_match(data, "=HALT"))
  		halt = SHUT_HALT;
  
  	/* Now we wait for runlevel change, or cancelled shutdown */
  }
  
  /*
   * Standard reboot/shutdown utilities talk to init using /run/initctl.
   * We should check if the fifo was recreated and reopen it.
   *
   * For SysV compatibility the default is to halt the system when issuing
   * `init 0`, unless INIT_HALT=POWERDOWN, as performed by the SysV utils.
   */
  static void parse(void *arg, int fd, int events)
  {
  	int lvl;
  	struct init_request rq;
  
  	while (1) {
  		ssize_t len = read(fd, &rq, sizeof(rq));
  
  		if (len <= 0) {
  			if (-1 == len) {
  				if (EINTR == errno)
  					continue;
  
  				if (EAGAIN == errno)
  					break;
  
  				_e("Failed reading initctl request, error %d: %s", errno, strerror(errno));
  			}
  
  			_d("Nothing to do, bailing out.");
  			break;
  		}
  
  		if (rq.magic != INIT_MAGIC || len != sizeof(rq)) {
  			_e("Invalid initctl request.");
  			break;
  		}
  
  		switch (rq.cmd) {
  		case INIT_CMD_RUNLVL:
  			switch (rq.runlevel) {
  			case 's':
  			case 'S':
  				rq.runlevel = '1'; /* Single user mode */
  				/* fallthrough */
  
  			case '0'...'9':
  				_d("Setting new runlevel %c", rq.runlevel);
  				lvl = rq.runlevel - '0';
  				if (lvl == 6)
  					halt = SHUT_REBOOT;
  				service_runlevel(lvl);
  				break;
  
  			default:
  				_d("Unsupported runlevel: %d", rq.runlevel);
  				break;
  			}
  			break;
  
  		case INIT_CMD_RELOAD:
  			service_reload_dynamic();
  			break;
  
  		case INIT_CMD_SETENV:
  			set_env(rq.data);
  			break;
  
  		default:
  			_d("Unsupported cmd: %d", rq.cmd);
  			break;
  		}
  	}
  
  	close(fd);
  	fifo_open();
  }
  
  /* Must run after the base FS is up, needs /run, or /var/run */
  static void setup(void *arg)
  {
  	_d("Setting up %s", FINIT_FIFO);
  	makefifo(FINIT_FIFO, 0600);
  
  	fifo_open();
  	plugin_io_init(&plugin);
  }
  
  PLUGIN_INIT(plugin_init)
  {
  	plugin_register(&plugin);
  }
  
  PLUGIN_EXIT(plugin_exit)
  {
  	plugin_unregister(&plugin);
  }
  
  /**
   * Local Variables:
   *  indent-tabs-mode: t
   *  c-file-style: "linux"
   * End:
   */
  