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SnmpMsg.javaAPI DocJava SE 5 API14915Fri Aug 26 14:55:02 BST 2005com.sun.jmx.snmp

SnmpMsg

public abstract class SnmpMsg extends Object implements SnmpDefinitions
A partially decoded representation of an SNMP packet. It contains the information contained in any SNMP message (SNMPv1, SNMPv2 or SNMPv3).

This API is a Sun Microsystems internal API and is subject to change without notice.

since
1.5

Fields Summary
public int
version
The protocol version.

decodeMessage and encodeMessage do not perform any check on this value.
decodeSnmpPdu and encodeSnmpPdu only accept the values 0 (for SNMPv1), 1 (for SNMPv2) and 3 (for SNMPv3).

public byte[]
data
Encoding of the PDU.

This is usually the BER encoding of the PDU's syntax defined in RFC1157 and RFC1902. However, this can be authenticated or encrypted data (but you need to implemented your own SnmpPduFactory class).

public int
dataLength
Number of useful bytes in the data field.
public InetAddress
address
Source or destination address.
For an incoming message it's the source. For an outgoing message it's the destination.
public int
port
Source or destination port.
For an incoming message it's the source. For an outgoing message it's the destination.
public com.sun.jmx.snmp.SnmpSecurityParameters
securityParameters
Security parameters. Contain informations according to Security Model (Usm, community string based, ...).
Constructors Summary
Methods Summary
public abstract voiddecodeMessage(byte[] inputBytes, int byteCount)
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 abstract SnmpPdudecodeSnmpPdu()
Gets the PDU encoded in this message.


This method decodes the data field and returns the resulting PDU.
return
The resulting PDU.
exception
SnmpStatusException If the encoding is not valid.
public SnmpVarBind[]decodeVarBindList(BerDecoder bdec)
For SNMP Runtime private use only.
	    bdec.openSequence() ;
	    Vector tmp = new Vector() ;
	    while (bdec.cannotCloseSequence()) {
		SnmpVarBind bind = new SnmpVarBind() ;
		bdec.openSequence() ;
		bind.oid = new SnmpOid(bdec.fetchOid()) ;
		bind.setSnmpValue(decodeVarBindValue(bdec)) ;
		bdec.closeSequence() ;
		tmp.addElement(bind) ;
	    }
	    bdec.closeSequence() ;
	    SnmpVarBind[] varBindList= new SnmpVarBind[tmp.size()] ;
	    tmp.copyInto(varBindList);
	    return varBindList ;
	
SnmpValuedecodeVarBindValue(BerDecoder bdec)
For SNMP Runtime private use only.
        SnmpValue result = null ;
        int tag = bdec.getTag() ;

	// bugId 4641696 : RuntimeExceptions must be transformed in 
	//                 BerException.
        switch(tag) {
	    
            //
            // Simple syntax
            //
        case BerDecoder.IntegerTag :
	    try {
		result = new SnmpInt(bdec.fetchInteger()) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpInt from decoded value.");
	    }
            break ;
        case BerDecoder.OctetStringTag :
	    try {
		result = new SnmpString(bdec.fetchOctetString()) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpString from decoded value.");
	    }
            break ;
        case BerDecoder.OidTag :
	    try {
		result = new SnmpOid(bdec.fetchOid()) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpOid from decoded value.");
	    }
            break ;
        case BerDecoder.NullTag :
            bdec.fetchNull() ;
	    try {
		result = new SnmpNull() ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpNull from decoded value.");
	    }
            break ;

            //
            // Application syntax
            //
        case SnmpValue.IpAddressTag :
	    try {
		result = new SnmpIpAddress(bdec.fetchOctetString(tag)) ;
	    } catch (RuntimeException r) {
		throw new  BerException();
	      // BerException("Can't build SnmpIpAddress from decoded value.");
	    }
            break ;
        case SnmpValue.CounterTag :
	    try {
		result = new SnmpCounter(bdec.fetchIntegerAsLong(tag)) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpCounter from decoded value.");
	    }
            break ;
        case SnmpValue.GaugeTag :
	    try {
		result = new SnmpGauge(bdec.fetchIntegerAsLong(tag)) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpGauge from decoded value.");
	    }
            break ;
        case SnmpValue.TimeticksTag :
	    try {
		result = new SnmpTimeticks(bdec.fetchIntegerAsLong(tag)) ;
	    } catch(RuntimeException r) {
		throw new BerException();
	     // BerException("Can't build SnmpTimeticks from decoded value.");
	    }
            break ;
        case SnmpValue.OpaqueTag :
	    try {
		result = new SnmpOpaque(bdec.fetchOctetString(tag)) ;
	    } catch(RuntimeException r) {
		throw new BerException();
		// BerException("Can't build SnmpOpaque from decoded value.");
	    }
            break ;
      
            //
            // V2 syntaxes
            //
        case SnmpValue.Counter64Tag :
            if (version == snmpVersionOne) {
                throw new BerException(BerException.BAD_VERSION) ;
            }
	    try {
		result = new SnmpCounter64(bdec.fetchIntegerAsLong(tag)) ;
	    } catch(RuntimeException r) {
		throw new BerException();
	     // BerException("Can't build SnmpCounter64 from decoded value.");
	    }
            break ;
    
        case SnmpVarBind.errNoSuchObjectTag :
            if (version == snmpVersionOne) {
                throw new BerException(BerException.BAD_VERSION) ;
            }
            bdec.fetchNull(tag) ;
            result = SnmpVarBind.noSuchObject ;
            break ;
        
        case SnmpVarBind.errNoSuchInstanceTag :
            if (version == snmpVersionOne) {
                throw new BerException(BerException.BAD_VERSION) ;
            }
            bdec.fetchNull(tag) ;
            result = SnmpVarBind.noSuchInstance ;
            break ;
        
        case SnmpVarBind.errEndOfMibViewTag :
            if (version == snmpVersionOne) {
                throw new BerException(BerException.BAD_VERSION) ;
            }
            bdec.fetchNull(tag) ;
            result = SnmpVarBind.endOfMibView ;
            break ;
        
        default:
            throw new BerException() ;

        }
    
        return result ;
    
public static java.lang.StringdumpHexBuffer(byte[] b, int offset, int len)
Dumps the content of a byte buffer using hexadecimal form.
param
b The buffer to dump.
param
offset The position of the first byte to be dumped.
param
len The number of bytes to be dumped starting from offset.
return
The string containing the dump.
 
        StringBuffer buf = new StringBuffer(len << 1) ;
        int k = 1 ; 
        int flen = offset + len ; 
 
        for (int i = offset; i < flen ; i++) { 
            int j = b[i] & 0xFF ; 
            buf.append(Character.forDigit((j >>> 4) , 16)) ; 
            buf.append(Character.forDigit((j & 0x0F), 16)) ; 
            k++ ; 
            if (k%16 == 0) { 
                buf.append('\n") ; 
                k = 1 ; 
            } else 
                buf.append(' ") ; 
        } 
        return buf.toString() ; 
    
public abstract intencodeMessage(byte[] outputBytes)
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 abstract voidencodeSnmpPdu(SnmpPdu pdu, int maxDataLength)
Initializes this message with the specified pdu.


This method initializes the data field with an array of
maxDataLength bytes. It encodes the pdu.
The resulting encoding is stored in the data field
and the length of the encoding is stored in dataLength.


If the encoding length exceeds maxDataLength,
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 pdu is not valid.
exception
SnmpTooBigException If the resulting encoding does not fit
into maxDataLength bytes.
exception
ArrayIndexOutOfBoundsException If the encoding exceeds maxDataLength.
public voidencodeVarBindList(BerEncoder benc, SnmpVarBind[] varBindList)
For SNMP Runtime private use only.
        //
        // Remember: the encoder does backward encoding
        //
        int encodedVarBindCount = 0 ;
        try {
            benc.openSequence() ;
            if (varBindList != null) {
                for (int i = varBindList.length - 1 ; i >= 0 ; i--) {
                    SnmpVarBind bind = varBindList[i] ;
                    if (bind != null) {
                        benc.openSequence() ;
                        encodeVarBindValue(benc, bind.value) ;
                        benc.putOid(bind.oid.longValue()) ;
                        benc.closeSequence() ;
                        encodedVarBindCount++ ;
                    }
                }  
            }  
            benc.closeSequence() ;
        }
        catch(ArrayIndexOutOfBoundsException x) {
            throw new SnmpTooBigException(encodedVarBindCount) ;
        }
    
voidencodeVarBindValue(BerEncoder benc, SnmpValue v)
For SNMP Runtime private use only.
        if (v == null) {
            benc.putNull() ;
        }
        else if (v instanceof SnmpIpAddress) {
            benc.putOctetString(((SnmpIpAddress)v).byteValue(), SnmpValue.IpAddressTag) ;
        }
        else if (v instanceof SnmpCounter) {
            benc.putInteger(((SnmpCounter)v).longValue(), SnmpValue.CounterTag) ;
        }
        else if (v instanceof SnmpGauge) {
            benc.putInteger(((SnmpGauge)v).longValue(), SnmpValue.GaugeTag) ;
        }
        else if (v instanceof SnmpTimeticks) {
            benc.putInteger(((SnmpTimeticks)v).longValue(), SnmpValue.TimeticksTag) ;
        }
        else if (v instanceof SnmpOpaque) {
            benc.putOctetString(((SnmpOpaque)v).byteValue(), SnmpValue.OpaqueTag) ;
        }
        else if (v instanceof SnmpInt) {
            benc.putInteger(((SnmpInt)v).intValue()) ;
        }
        else if (v instanceof SnmpString) {
            benc.putOctetString(((SnmpString)v).byteValue()) ;
        }
        else if (v instanceof SnmpOid) {
            benc.putOid(((SnmpOid)v).longValue()) ;
        }
        else if (v instanceof SnmpCounter64) {
            if (version == snmpVersionOne) {
                throw new SnmpStatusException("Invalid value for SNMP v1 : " + v) ;
            }  
            benc.putInteger(((SnmpCounter64)v).longValue(), SnmpValue.Counter64Tag) ;
        }
        else if (v instanceof SnmpNull) {
            int tag = ((SnmpNull)v).getTag() ;
            if ((version == snmpVersionOne) && (tag != SnmpValue.NullTag)) {
                throw new SnmpStatusException("Invalid value for SNMP v1 : " + v) ;
            }
            if ((version == snmpVersionTwo) &&
                (tag != SnmpValue.NullTag) && 
                (tag != SnmpVarBind.errNoSuchObjectTag) && 
                (tag != SnmpVarBind.errNoSuchInstanceTag) &&
                (tag != SnmpVarBind.errEndOfMibViewTag)) {
                throw new SnmpStatusException("Invalid value " + v) ;
            }
            benc.putNull(tag) ;
        }
        else {
            throw new SnmpStatusException("Invalid value " + v) ;
        }
    
    
public static intgetProtocolVersion(byte[] data)
Returns the encoded SNMP version present in the passed byte array.
param
data The unmarshalled SNMP message.
return
The SNMP version (0, 1 or 3).
                                  
         
	  
	int version = 0;
	BerDecoder bdec = null;	
	try {
	    bdec = new BerDecoder(data);
	    bdec.openSequence();
	    version = bdec.fetchInteger();
	}
        catch(BerException x) {
            throw new SnmpStatusException("Invalid encoding") ;
        }
	try {
	    bdec.closeSequence();
	}
        catch(BerException x) {
        }
	return version;
    
public abstract intgetRequestId(byte[] data)
Returns the associated request ID.
param
data The flat message.
return
The request ID.
public java.lang.StringprintMessage()
Dumps this message in a string.
return
The string containing the dump.
        StringBuffer sb = new StringBuffer() ;
        sb.append("Version: ") ;
        sb.append(version) ;
        sb.append("\n") ;
        if (data == null) {
            sb.append("Data: null") ;
        }
        else {
            sb.append("Data: {\n") ;
            sb.append(dumpHexBuffer(data, 0, dataLength)) ;
            sb.append("\n}\n") ;
        }

        return sb.toString() ;