/*
 *  Copyright (C) 2000-2007 Proxmox Server Solutions GmbH. All rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

void
exec_init (char *argv[], char *envp[])
{
    execve ("/sbin/init.org", argv, envp);
    execve ("/etc/init", argv, envp);
    execve ("/bin/init", argv, envp);

    exit (-1); // not reached
}

static int terminate = 0;

void 
sigterm_handler (int signum)
{
  terminate = 1;
}

int
main (int argc, char *argv[], char *envp[])
{
  int pid;

  pid = getpid();

  if (pid == 1) {
        
    if (mkfifo ("/var/log/init.fifo", 0644) != 0) {
      if (errno != EEXIST) {
	// perror ("unable to create fifo");
	exec_init (argv, envp); // start without log
      }
    }

    char *envp[] = {"HOME=/", "TERM=linux", "CONSOLE=/var/log/init.fifo", NULL};
    pid = fork ();

    if (pid > 0) {
      exec_init (argv, envp);
    }

    if (pid == 0) { // child
      struct sigaction act;
      int fd;
      int fifo;
      int len;
      
      char buf[4096];

      char *txt;
      char txtbuf[4096];

      sigemptyset(&act.sa_mask);
      act.sa_handler = sigterm_handler;
      act.sa_flags = SA_RESETHAND;
      sigaction(SIGTERM, &act, NULL);

      if ((fd = open("/var/log/init.log", O_CREAT|O_WRONLY|O_TRUNC, 0644)) == -1) {
	// perror ("unable to open '/var/log/init.log'");
	exit (-1);
      }

      if ((fifo = open("/var/log/init.fifo", O_RDONLY)) == -1) {
	sprintf (txtbuf, "ERROR: unable to open fifo: %s\n", strerror(errno));
	write (fd, txtbuf, strlen (txtbuf));
	exit (-1);
      }

      while (1) {

	len = read (fifo, buf, 4096);
	
	if (terminate) { // got signal 
	  if (len > 0) {
	    write (fd, buf, len);
	  }
	  break;
	}
	if (len == -1) {
	  if (errno == EAGAIN || errno == EINTR) {
	    continue;
	  }

	  sprintf (txtbuf, "ERROR: unable to read fifo: %s\n", strerror(errno));
	  write (fd, txtbuf, strlen (txtbuf));
	  break;
	}

	if (len == 0) { // EOF - try later
	  sleep (1);
	  continue;
	}
	write (fd, buf, len);
      }
     
      // terminated - just write a CR
      txt = "\n"; write (fd, txt, strlen (txt));

      close (fifo);
      close (fd);
    }

  } else {
    // controll call (/sbin/telinit)
    exec_init (argv, envp);
  }

  exit (0);
}