// Syslog - Unix-compatible syslog routines
//
// Original version by Tim Endres, <time@ice.com>.
//
// Re-written and fixed up by Jef Poskanzer <jef@mail.acme.com>.
//
// Copyright (C)1996 by Jef Poskanzer <jef@mail.acme.com>. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme;

import java.io.*;
import java.net.*;

// Unix-compatible syslog routines.
// <P>
/// The Syslog class implements the Unix syslog protocol allowing Java
// to log messages to the standard syslog files. Care has been taken to
// preserve as much of the Unix implementation as possible.
// <p>
// To use Syslog, simply create an instance, and use the syslog() method
// to log your message. The class provides all the expected syslog constants.
// For example, LOG_ERR is Syslog.LOG_ERR.
// <P>
// Original version by <A HREF="http://www.ice.com/~time/">Tim Endres</A><BR>
// <A HREF="/resources/classes/Acme/Syslog.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>

public class Syslog
    {

    // Priorities.
    public static final int LOG_EMERG	= 0; // system is unusable
    public static final int LOG_ALERT	= 1; // action must be taken immediately
    public static final int LOG_CRIT	= 2; // critical conditions
    public static final int LOG_ERR	= 3; // error conditions
    public static final int LOG_WARNING	= 4; // warning conditions
    public static final int LOG_NOTICE	= 5; // normal but significant condition
    public static final int LOG_INFO	= 6; // informational
    public static final int LOG_DEBUG	= 7; // debug-level messages
    public static final int LOG_PRIMASK = 0x0007; // mask to extract priority

    // Facilities.
    public static final int LOG_KERN	= (0<<3); // kernel messages
    public static final int LOG_USER	= (1<<3); // random user-level messages
    public static final int LOG_MAIL	= (2<<3); // mail system
    public static final int LOG_DAEMON	= (3<<3); // system daemons
    public static final int LOG_AUTH	= (4<<3); // security/authorization
    public static final int LOG_SYSLOG	= (5<<3); // internal syslogd use
    public static final int LOG_LPR	= (6<<3); // line printer subsystem
    public static final int LOG_NEWS	= (7<<3); // network news subsystem
    public static final int LOG_UUCP	= (8<<3); // UUCP subsystem
    public static final int LOG_CRON	= (15<<3); // clock daemon
    // Other codes through 15 reserved for system use.
    public static final int LOG_LOCAL0	= (16<<3); // reserved for local use
    public static final int LOG_LOCAL1	= (17<<3); // reserved for local use
    public static final int LOG_LOCAL2	= (18<<3); // reserved for local use
    public static final int LOG_LOCAL3	= (19<<3); // reserved for local use
    public static final int LOG_LOCAL4	= (20<<3); // reserved for local use
    public static final int LOG_LOCAL5	= (21<<3); // reserved for local use
    public static final int LOG_LOCAL6	= (22<<3); // reserved for local use
    public static final int LOG_LOCAL7	= (23<<3); // reserved for local use

    public static final int LOG_FACMASK	= 0x03F8; // mask to extract facility

    // Option flags.
    public static final int LOG_PID	= 0x01; // log the pid with each message
    public static final int LOG_CONS	= 0x02; // log on the console if errors
    public static final int LOG_NDELAY	= 0x08; // don't delay open
    public static final int LOG_NOWAIT	= 0x10; // don't wait for console forks


    private static final int PORT = 514;

    private String		ident;
    private int			logopt;
    private int			facility;

    private InetAddress		address;
    private DatagramPacket	packet;
    private DatagramSocket	socket;


    /// Creating a Syslog instance is equivalent of the Unix openlog() call.
    // @exception SyslogException if there was a problem
    public Syslog( String ident, int logopt, int facility ) throws SyslogException
	{
	if ( ident == null )
	    this.ident = new String( Thread.currentThread().getName() );
	else
	    this.ident = ident;
	this.logopt = logopt;
	this.facility = facility;

	try
	    {
	    address = InetAddress.getLocalHost();
	    }
	catch ( UnknownHostException e )
	    {
	    throw new SyslogException(
		"error locating localhost: " + e.getMessage() );
	    }
	try
	    {
	    socket = new DatagramSocket();
	    }
	catch ( SocketException e )
	    {
	    throw new SyslogException( 
		"error creating syslog udp socket: " + e.getMessage() );
	    }
	catch ( IOException e )
	    {
	    throw new SyslogException( 
		"error creating syslog udp socket: " + e.getMessage() );
	    }
	}

    /// Use this method to log your syslog messages. The facility and
    // level are the same as their Unix counterparts, and the Syslog
    // class provides constants for these fields. The msg is what is
    // actually logged.
    // @exception SyslogException if there was a problem
    public void syslog( int priority, String msg ) throws SyslogException
	{
	int		pricode;
	int		length;
	int		idx, sidx, nidx;
	StringBuffer	buffer;
	byte[]		data;
	byte[]		numbuf = new byte[32];
	String		strObj;

	pricode = MakePriorityCode( facility, priority );
	Integer priObj = new Integer( pricode );

	length = 4 + ident.length() + msg.length() + 1;
	length += ( pricode > 99 ) ? 3 : ( ( pricode > 9 ) ? 2 : 1 );

	data = new byte[length];

	idx = 0;
	data[idx++] = (byte) '<';

	strObj = priObj.toString( priObj.intValue() );
	strObj.getBytes( 0, strObj.length(), data, idx );
	idx += strObj.length();

	data[idx++] = (byte) '>';

	ident.getBytes( 0, ident.length(), data, idx );
	idx += ident.length();

	data[idx++] = (byte) ':';
	data[idx++] = (byte) ' ';

	msg.getBytes( 0, msg.length(), data, idx );
	idx += msg.length();

	data[idx] = 0;

	packet = new DatagramPacket( data, length, address, PORT );

	try
	    {
	    socket.send( packet );
	    }
	catch ( IOException e )
	    {
	    throw new SyslogException(
		"error sending message: '" + e.getMessage() + "'" );
	    }
	}

    private int MakePriorityCode( int facility, int priority )
	{
	return ( ( facility & LOG_FACMASK ) | priority );
	}


/******************************************************************************
    /// Test routine.
    public static void main( String args[] )
	{
	try
	    {
	    Syslog s = new Syslog( null, 0, LOG_LOCAL1 );
	    s.syslog( Syslog.LOG_ERR, "Hello." );
	    }
	catch ( SyslogException e )
	    {
	    System.err.println( e.toString() );
	    }
	}
******************************************************************************/

    }