/*
 * @(#)file      SnmpMessage.java
 * @(#)author    Sun Microsystems, Inc.
 * @(#)version   4.32
 * @(#)date      07/06/14
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 */


package com.sun.jmx.snmp;


// "@(#)SnmpMessage.java 1.1 98/07/23 SMI"

// java imports
//
import java.util.Vector;
import java.net.InetAddress;

// import debug stuff
//
import com.sun.jmx.trace.Trace;

/**
 * Is a partially decoded representation of an SNMP packet.
 * <P>
 * You will not normally need to use this class unless you decide to
 * implement your own {@link com.sun.jmx.snmp.SnmpPduFactory SnmpPduFactory} object.
 * <P>
 * The <CODE>SnmpMessage</CODE> class is directly mapped onto the 
 * <CODE>Message</CODE> syntax defined in RFC1157 and RFC1902.
 * <BLOCKQUOTE>
 * <PRE>
 * Message ::= SEQUENCE {
 *    version       INTEGER { version(1) }, -- for SNMPv2
 *    community     OCTET STRING,           -- community name
 *    data          ANY                     -- an SNMPv2 PDU
 * }
 * </PRE>
 * </BLOCKQUOTE>
 *
 * <p><b>This API is a Sun Microsystems internal API  and is subject 
 * to change without notice.</b></p>
 * @see SnmpPduFactory
 * @see SnmpPduPacket
 *
 * @version     1.1     07/23/98
 * @author      Sun Microsystems, Inc
 */

public class SnmpMessage extends SnmpMsg implements SnmpDefinitions {
    /**
     * Community name.
     */
    public byte[] community ;
  
    /**
     * Encodes this message and puts the result in the specified byte array.
     * For internal use only.
     * 
     * @param outputBytes An array to receive the resulting encoding.
     *
     * @exception ArrayIndexOutOfBoundsException If the result does not fit
     *                                           into the specified array.
     */
    public int encodeMessage(byte[] outputBytes) throws SnmpTooBigException {
        int encodingLength = 0 ;
        if (data == null)
            throw new IllegalArgumentException("Data field is null") ;

        //
        // Reminder: BerEncoder does backward encoding !
        //
        try {
            BerEncoder benc = new BerEncoder(outputBytes) ;
            benc.openSequence() ;
            benc.putAny(data, dataLength) ;
            benc.putOctetString((community != null) ? community : new byte[0]) ;
            benc.putInteger(version) ;
            benc.closeSequence() ;
            encodingLength = benc.trim() ;
        }
        catch(ArrayIndexOutOfBoundsException x) {
            throw new SnmpTooBigException() ;
        }
    
        return encodingLength ;
    }
    /**
     * Returns the associated request ID.
     * @param inputBytes The flat message.
     * @return The request ID.
     *
     * @since 1.5
     */
    public int getRequestId(byte[] inputBytes) throws SnmpStatusException {
	int requestId = 0;
	BerDecoder bdec = null;	
	BerDecoder bdec2 = null;
	byte[] any = null;
	try {
	    bdec = new BerDecoder(inputBytes);
	    bdec.openSequence();
	    bdec.fetchInteger();
            bdec.fetchOctetString();
	    any = bdec.fetchAny();
	    bdec2 = new BerDecoder(any);
            int type = bdec2.getTag();
            bdec2.openSequence(type);
	    requestId = bdec2.fetchInteger();
	}
        catch(BerException x) {
            throw new SnmpStatusException("Invalid encoding") ;
        }
	try {
	    bdec.closeSequence();
	}
        catch(BerException x) {
        }
	try {
	    bdec2.closeSequence();
	}
        catch(BerException x) {
        }
	return requestId;
    }
    /**
     * Decodes the specified bytes and initializes this message.
     * For internal use only.
     * 
     * @param inputBytes The bytes to be decoded.
     *
     * @exception SnmpStatusException If the specified bytes are not a valid encoding.
     */
    public void decodeMessage(byte[] inputBytes, int byteCount) 
        throws SnmpStatusException {
        try {
            BerDecoder bdec = new BerDecoder(inputBytes/*, byteCount */) ; // FIXME
            bdec.openSequence() ;
            version = bdec.fetchInteger() ;
            community = bdec.fetchOctetString() ;
            data = bdec.fetchAny() ;
            dataLength = data.length ;
            bdec.closeSequence() ;
        }
        catch(BerException x) {
            throw new SnmpStatusException("Invalid encoding") ;
        }
    }
  
    /**
     * Initializes this message with the specified <CODE>pdu</CODE>.
     * <P>
     * This method initializes the data field with an array of 
     * <CODE>maxDataLength</CODE> bytes. It encodes the <CODE>pdu</CODE>. 
     * The resulting encoding is stored in the data field
     * and the length of the encoding is stored in <CODE>dataLength</CODE>.
     * <p>
     * If the encoding length exceeds <CODE>maxDataLength</CODE>, 
     * the method throws an exception.
     * 
     * @param pdu The PDU to be encoded.
     * @param maxDataLength The maximum length permitted for the data field.
     *
     * @exception SnmpStatusException If the specified <CODE>pdu</CODE> is not valid.
     * @exception SnmpTooBigException If the resulting encoding does not fit
     * into <CODE>maxDataLength</CODE> bytes.
     * @exception ArrayIndexOutOfBoundsException If the encoding exceeds <CODE>maxDataLength</CODE>.
     *
     * @since 1.5
     */  
    public void encodeSnmpPdu(SnmpPdu pdu, int maxDataLength) 
        throws SnmpStatusException, SnmpTooBigException {
	//
        // The easy work
        //
	SnmpPduPacket pdupacket = (SnmpPduPacket) pdu;
        version = pdupacket.version ;
        community = pdupacket.community ;
        address = pdupacket.address ;
        port = pdupacket.port ;
    
        //
        // Allocate the array to receive the encoding.
        //
        data = new byte[maxDataLength] ;
    
        //
        // Encode the pdupacket
        // Reminder: BerEncoder does backward encoding !
        //
    
        try {
            BerEncoder benc = new BerEncoder(data) ;
            benc.openSequence() ;
            encodeVarBindList(benc, pdupacket.varBindList) ;

            switch(pdupacket.type) {

            case pduGetRequestPdu :
            case pduGetNextRequestPdu :
            case pduInformRequestPdu :
            case pduGetResponsePdu :
            case pduSetRequestPdu :
            case pduV2TrapPdu :
            case pduReportPdu :
                SnmpPduRequest reqPdu = (SnmpPduRequest)pdupacket ;
                benc.putInteger(reqPdu.errorIndex) ;
                benc.putInteger(reqPdu.errorStatus) ;
                benc.putInteger(reqPdu.requestId) ;
                break ;

            case pduGetBulkRequestPdu :
                SnmpPduBulk bulkPdu = (SnmpPduBulk)pdupacket ;
                benc.putInteger(bulkPdu.maxRepetitions) ;
                benc.putInteger(bulkPdu.nonRepeaters) ;
                benc.putInteger(bulkPdu.requestId) ;
                break ;

            case pduV1TrapPdu :
                SnmpPduTrap trapPdu = (SnmpPduTrap)pdupacket ;
                benc.putInteger(trapPdu.timeStamp, SnmpValue.TimeticksTag) ;
                benc.putInteger(trapPdu.specificTrap) ;
                benc.putInteger(trapPdu.genericTrap) ;
		if(trapPdu.agentAddr != null)
		    benc.putOctetString(trapPdu.agentAddr.byteValue(), SnmpValue.IpAddressTag) ;
		else
		    benc.putOctetString(new byte[0], SnmpValue.IpAddressTag);
                benc.putOid(trapPdu.enterprise.longValue()) ;
                break ;

            default:
                throw new SnmpStatusException("Invalid pdu type " + String.valueOf(pdupacket.type)) ;
            }
            benc.closeSequence(pdupacket.type) ;
            dataLength = benc.trim() ;
        }
        catch(ArrayIndexOutOfBoundsException x) {
            throw new SnmpTooBigException() ;
        }	
    }
    /**
     * Gets the PDU encoded in this message.
     * <P>
     * This method decodes the data field and returns the resulting PDU.
     * 
     * @return The resulting PDU.
     * @exception SnmpStatusException If the encoding is not valid.
     *
     * @since 1.5
     */
    public SnmpPdu decodeSnmpPdu() 
        throws SnmpStatusException {
	//
        // Decode the pdu
        //
        SnmpPduPacket pdu = null ;
        BerDecoder bdec = new BerDecoder(data) ;
        try {
            int type = bdec.getTag() ;
            bdec.openSequence(type) ;
            switch(type) {
		
            case pduGetRequestPdu :
            case pduGetNextRequestPdu :
            case pduInformRequestPdu :
            case pduGetResponsePdu :
            case pduSetRequestPdu :
            case pduV2TrapPdu :
            case pduReportPdu :
                SnmpPduRequest reqPdu = new SnmpPduRequest() ;
                reqPdu.requestId = bdec.fetchInteger() ;
                reqPdu.errorStatus = bdec.fetchInteger() ;
                reqPdu.errorIndex = bdec.fetchInteger() ;
                pdu = reqPdu ;
                break ;

            case pduGetBulkRequestPdu :
                SnmpPduBulk bulkPdu = new SnmpPduBulk() ;
                bulkPdu.requestId = bdec.fetchInteger() ;
                bulkPdu.nonRepeaters = bdec.fetchInteger() ;
                bulkPdu.maxRepetitions = bdec.fetchInteger() ;
                pdu = bulkPdu ;
                break ;

            case pduV1TrapPdu :
                SnmpPduTrap trapPdu = new SnmpPduTrap() ;
                trapPdu.enterprise = new SnmpOid(bdec.fetchOid()) ;
		byte []b = bdec.fetchOctetString(SnmpValue.IpAddressTag);
		if(b.length != 0)
		    trapPdu.agentAddr = new SnmpIpAddress(b) ;
		else
		    trapPdu.agentAddr = null;
                trapPdu.genericTrap = bdec.fetchInteger() ;
                trapPdu.specificTrap = bdec.fetchInteger() ;
                trapPdu.timeStamp = bdec.fetchInteger(SnmpValue.TimeticksTag) ;
                pdu = trapPdu ;
                break ;

            default:
                throw new SnmpStatusException(snmpRspWrongEncoding) ;
            }
            pdu.type = type ;
            pdu.varBindList = decodeVarBindList(bdec) ;  
            bdec.closeSequence() ;
        } catch(BerException e) {
            if (isDebugOn()) {
                debug("decodeSnmpPdu", e);
            }
            throw new SnmpStatusException(snmpRspWrongEncoding);
        } catch(IllegalArgumentException e) {
	    // bug id 4654066
            if (isDebugOn()) {
                debug("decodeSnmpPdu", e);
            }
            throw new SnmpStatusException(snmpRspWrongEncoding);
        }
    
        //
        // The easy work
        //
        pdu.version = version ;
        pdu.community = community ;
        pdu.address = address ;
        pdu.port = port ;
    
        return pdu;
    }
    /**
     * Dumps this message in a string.
     *
     * @return The string containing the dump.
     */
    public String printMessage() {
	StringBuffer sb = new StringBuffer();
	if (community == null) {
            sb.append("Community: null") ;
        }
        else {
            sb.append("Community: {\n") ;
            sb.append(dumpHexBuffer(community, 0, community.length)) ;
            sb.append("\n}\n") ;
        }
	return sb.append(super.printMessage()).toString();	
    }
    // TRACES & DEBUG
    //---------------
    
    boolean isTraceOn() {
        return Trace.isSelected(Trace.LEVEL_TRACE, Trace.INFO_SNMP);
    }

    void trace(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_TRACE, Trace.INFO_SNMP, clz, func, info);
    }

    void trace(String func, String info) {
        trace(dbgTag, func, info);
    }
    
    boolean isDebugOn() {
        return Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_SNMP);
    }

    void debug(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_SNMP, clz, func, info);
    }

    void debug(String clz, String func, Throwable exception) {
        Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_SNMP, clz, func, exception);
    }

    void debug(String func, String info) {
        debug(dbgTag, func, info);
    }
    
    void debug(String func, Throwable exception) {
        debug(dbgTag, func, exception);
    }
    
    String dbgTag = "SnmpMessage";
}




