snmpcontext.java

snmp zip 包开发snmp协议

// NAME
//      $RCSfile: SnmpContext.java,v $
// DESCRIPTION
//      [given below in javadoc format]
// DELTA
//      $Revision: 3.23 $
// CREATED
//      $Date: 2006/02/09 14:24:15 $
// COPYRIGHT
//      Westhawk Ltd
// TO DO
//

/*
 * Copyright (C) 1995, 1996 by West Consulting BV
 *
 * Permission to use, copy, modify, and distribute this software
 * for any purpose and without fee is hereby granted, provided
 * that the above copyright notices appear in all copies and that
 * both the copyright notice and this permission notice appear in
 * supporting documentation.
 * This software is provided "as is" without express or implied
 * warranty.
 * author <a href="mailto:[e-mail]">Tim Panton</a>
 */

/*
 * Copyright (C) 1996 - 2006 by Westhawk Ltd
 * <a href="www.westhawk.co.uk">www.westhawk.co.uk</a>
 *
 * Permission to use, copy, modify, and distribute this software
 * for any purpose and without fee is hereby granted, provided
 * that the above copyright notices appear in all copies and that
 * both the copyright notice and this permission notice appear in
 * supporting documentation.
 * This software is provided "as is" without express or implied
 * warranty.
 * author <a href="mailto:[e-mail]">Tim Panton</a>
 */

package uk.co.westhawk.snmp.stack;

import java.net.*;
import java.io.*;
import java.util.*;
import uk.co.westhawk.snmp.event.*;

/**
 * This class contains the SNMP v1 context that is needed by every PDU to
 * send a SNMP v1 request.
 *
 * <p>
 * <code>destroy()</code> should be called when the context is no longer
 * used. This is the only way the threads will be stopped and garbage
 * collected.
 * </p>
 *
 * @see SnmpContextFace
 * @see SnmpContextPool
 * @author <a href="mailto:[e-mail]">Tim Panton</a>
 * @version $Revision: 3.23 $ $Date: 2006/02/09 14:24:15 $
 */
public class SnmpContext extends AbstractSnmpContext 
implements SnmpContextFace, Cloneable
{
    private static final String     version_id =
        "@(#)$Id: SnmpContext.java,v 3.23 2006/02/09 14:24:15 birgit Exp $ Copyright Westhawk Ltd";

    String community = SnmpContextFace.DEFAULT_COMMUNITY;

/**
 * Constructor.
 *
 * @param host The host to which the PDU will be sent
 * @param port The port where the SNMP server will be
 * @see AbstractSnmpContext#AbstractSnmpContext(String, int)
 */
public SnmpContext(String host, int port) throws java.io.IOException
{
    super(host, port);
}

/**
 * Constructor.
 *
 * @param host The host to which the Pdu will be sent
 * @param port The port where the SNMP server will be
 * @param typeSocketA The local address the server will bind to
 *
 * @see AbstractSnmpContext#AbstractSnmpContext(String, int, String)
 */
public SnmpContext(String host, int port, String typeSocketA) 
throws java.io.IOException
{
    super(host, port, typeSocketA);
}

/**
 * Constructor.
 *
 * @param host The host to which the PDU will be sent
 * @param port The port where the SNMP server will be
 * @param bindAddress The local address the server will bind to
 * @param typeSocketA The type of socket to use. 
 *
 * @see AbstractSnmpContext#AbstractSnmpContext(String, int, String, String)
 * @see SnmpContextBasisFace#STANDARD_SOCKET
 * @see SnmpContextBasisFace#TCP_SOCKET
 * @see SnmpContextBasisFace#NETSCAPE_SOCKET
 * @see SnmpContextBasisFace#KVM_SOCKET
 * @since 4_14
 */
public SnmpContext(String host, int port, String bindAddress, String typeSocketA) 
throws java.io.IOException
{
    super(host, port, bindAddress, typeSocketA);
}

public int getVersion()
{
    return SnmpConstants.SNMP_VERSION_1;
}

public String getCommunity()
{
    return community;
}

public void setCommunity(String newCommunity)
{
    community = newCommunity;
}

public byte[] encodePacket(byte msg_type, int rId, int errstat, 
      int errind, Enumeration ve, Object obj) 
      throws java.io.IOException, EncodingException
{
    byte [] packet = null;
    if (isDestroyed == true)
    {
        throw new EncodingException("Context can no longer be used, since it is already destroyed");
    }
    else
    {
        AsnEncoderv1 enc = new AsnEncoderv1();
        ByteArrayOutputStream bay = enc.EncodeSNMP(this, msg_type, rId, errstat,
              errind, ve);

        int sz = bay.size();
        if (sz > maxRecvSize)
        {
            throw new EncodingException("Packet size ("+ sz 
                + ") is > maximum size (" + maxRecvSize +")");
        }
        packet = bay.toByteArray();
    }
    return packet;
}


public byte[] encodePacket(byte msg_type, String enterprise, 
      byte[] IpAddress, int generic_trap, int specific_trap, 
      long timeTicks, Enumeration ve) 
      throws java.io.IOException, EncodingException
{
    byte [] packet = null;
    AsnEncoderv1 enc = new AsnEncoderv1();
    ByteArrayOutputStream bay = enc.EncodeSNMP(this, msg_type, enterprise, 
          IpAddress, generic_trap, specific_trap, timeTicks, ve);

    int sz = bay.size();
    if (sz > maxRecvSize)
    {
        throw new EncodingException("Packet size ("+ sz 
            + ") is > maximum size (" + maxRecvSize +")");
    }
    packet = bay.toByteArray();
    return packet;
}

/**
 * Processes an incoming SNMP v1 response.
 */
protected void processIncomingResponse(ByteArrayInputStream in)
throws DecodingException, IOException
{
    AsnDecoderv1 rpdu = new AsnDecoderv1();
    AsnSequence seqPdu = rpdu.DecodeSNMP(in, getCommunity());
    if (seqPdu instanceof AsnPduSequence)
    {
        AsnPduSequence pduSeq = (AsnPduSequence) seqPdu;
        if (pduSeq != null)
        {
            // got a message
            Integer rid = new Integer(pduSeq.getReqId());
            Pdu answ = getPdu(rid);
            if (answ != null)
            {
                answ.fillin(pduSeq);
            }
            else
            {
                if (AsnObject.debug > 3)
                {
                    System.out.println(getClass().getName() + ".processIncomingResponse(): No Pdu with reqid " + rid.intValue());
                }
            }
        }
        else
        {
            if (AsnObject.debug > 3)
            {
                System.out.println(getClass().getName() + ".processIncomingResponse(): Error - missing seq input");
            }
        }
    }
    else
    {
        // it must be a Trap
    }
}

public Pdu processIncomingPdu(byte [] message) 
throws DecodingException, IOException
{
    AsnDecoderv1 rpdu = new AsnDecoderv1();
    ByteArrayInputStream in = new ByteArrayInputStream(message);

    Pdu pdu = null;
    AsnSequence seqPdu = rpdu.DecodeSNMP(in, getCommunity());
    if (seqPdu instanceof AsnTrapPduv1Sequence)
    {
        AsnTrapPduv1Sequence pduSeq = (AsnTrapPduv1Sequence) seqPdu;
        if (pduSeq != null)
        {
            TrapPduv1 trapPdu = new uk.co.westhawk.snmp.stack.TrapPduv1(this);
            trapPdu.fillin(pduSeq);
            pdu = trapPdu;
        }
    }
    else
    {
        // must be an ordinary PDU
        AsnPduSequence pduSeq = (AsnPduSequence) seqPdu;
        if (pduSeq != null)
        {
            byte type = pduSeq.getRespType();
            switch (type)
            {
                case SnmpConstants.GET_REQ_MSG:
                    pdu = new uk.co.westhawk.snmp.stack.GetPdu(this);
                    break;
                case SnmpConstants.GETNEXT_REQ_MSG:
                    pdu = new uk.co.westhawk.snmp.stack.GetNextPdu(this);
                    break;
                case SnmpConstants.SET_REQ_MSG:
                    pdu = new uk.co.westhawk.snmp.stack.SetPdu(this);
                    break;
                //case SnmpConstants.GET_RSP_MSG:
                //  A longly response should never be received here.
                //  They should come in via the processIncomingResponse
                //  route.
                //case SnmpConstants.GETBULK_REQ_MSG:
                //  not in v1
                //case SnmpConstants.INFORM_REQ_MSG:
                //  not in v1
                //case SnmpConstants.GET_RPRT_MSG:
                //  not in v1
                //case SnmpConstants.TRPV2_REQ_MSG:
                //  not in v1
                default:
                    if (AsnObject.debug > 3)
                    {
                        System.out.println(getClass().getName() 
                            + ".ProcessIncomingPdu(): PDU received with type " 
                            + pduSeq.getRespTypeString()
                            + ". Ignoring it.");
                    }
            }

            if (pdu != null)
            {
                pdu.fillin(pduSeq);
            }
        }
    }
    return pdu;
}

/**
 * Returns a clone of this SnmpContext.
 *
 * @exception CloneNotSupportedException Thrown when the constructor
 * generates an IOException
 */
public Object clone() throws CloneNotSupportedException
{
    SnmpContext clContext = null;
    try
    {
        clContext = new SnmpContext(hostname, hostPort, bindAddr, typeSocket);
        clContext.setCommunity(new String(community));
    }
    catch (java.io.IOException exc)
    {
        throw new CloneNotSupportedException("IOException " 
            + exc.getMessage());
    }
    return clContext;
}


/**
 * Returns the hash key. This key is built out of all properties. It
 * serves as key for a hashtable of (v1) contexts.
 *
 * @since 4_14
 * @return The hash key
 */
public String getHashKey()
{
    String str = hostname
          + "_" + hostPort
          + "_" + typeSocket
          + "_" + community
          + "_v" + getVersion();
    return str;
}

/**
 * Returns a string representation of the object.
 *
 * @return The string
 */
public String toString()
{
    StringBuffer buffer = new StringBuffer("SnmpContext[");
    buffer.append("host=").append(hostname);
    buffer.append(", port=").append(hostPort);
    buffer.append(", bindAddress=").append(bindAddr);
    buffer.append(", socketType=").append(typeSocket);
    buffer.append(", community=").append(community);
    buffer.append(", #trapListeners=").append(trapSupport.getListenerCount());
    buffer.append(", #pduListeners=").append(pduSupport.getListenerCount());
    buffer.append("]");
    return buffer.toString();
}

}