snmpcontextv3basis.java

snmp zip 包开发snmp协议

            ret = "userPrivacyPassword is null, but usePrivacy is true";
        }
        else if (userPrivacyPassword.length() == 0) 
        {
            ret = "userPrivacyPassword is empty, but usePrivacy is true";
        }
        else if (useAuthentication == false) 
        {
            ret = "useAuthentication is false, but usePrivacy is true";
        }
    } 

    if (useAuthentication == true) 
    {
        if (userAuthenticationPassword == null) 
        {
            ret = "userAuthenticationPassword is null, but useAuthentication is true";
        }
        else if (userAuthenticationPassword.length() == 0) 
        {
            ret = "userAuthenticationPassword is empty, but useAuthentication is true";
        }
    }
    return ret;
}


/**
 * Does the actual encoding. 
 *
 * @see #encodeDiscoveryPacket
 * @see #encodePacket
 */
protected byte[] actualEncodePacket(byte msg_type, int rId, int errstat, 
      int errind, Enumeration ve, TimeWindowNode node, Object obj) 
      throws java.io.IOException, EncodingException
{
    AsnEncoderv3 enc = new AsnEncoderv3();
    String msg = checkContextSanity();
    if (msg != null)
    {
        throw new EncodingException(msg);
    }

    int msgId = ((Integer)obj).intValue();
    if (AsnObject.debug > 6)
    {
        System.out.println(getClass().getName() + ".actualEncodePacket(): msgId="
            + msgId + ", Pdu reqId=" + rId);
    }
    byte[] packet = enc.EncodeSNMPv3(this, msgId, node, 
          msg_type, rId, errstat, errind, ve);

    return packet;
}

/**
 * Processes an incoming SNMP v3 response.
 */
protected void processIncomingResponse(ByteArrayInputStream in)
throws DecodingException, IOException
{
    AsnDecoderv3 rpdu = new AsnDecoderv3();
    // don't have to check for context sanity here: if the request was
    // fine, so should be the response
    byte [] bu = null;
    // need to duplicate the message for V3 to rewrite 
    int nb = in.available();
    bu = new byte[nb];
    in.read(bu);
    in = new ByteArrayInputStream(bu);

    AsnSequence asnTopSeq = rpdu.DecodeSNMPv3(in);
    int msgId = rpdu.getMsgId(asnTopSeq);
    Integer rid = (Integer) msgIdHash.get(new Integer(msgId));
    if (rid != null)
    {
        if (AsnObject.debug > 6)
        {
            System.out.println(getClass().getName() + ".processIncomingResponse(): msgId="
                + msgId + ", Pdu reqId=" + rid);
        }
        Pdu pdu = getPdu(rid);
        try
        {
            AsnPduSequence pduSeq = rpdu.processSNMPv3(this, asnTopSeq, bu, false);
            if (pduSeq != null)
            {
                // got a message
                Integer rid2 = new Integer(pduSeq.getReqId());
                if (AsnObject.debug > 6)
                {
                    System.out.println(getClass().getName() + ".processIncomingResponse():"
                    + " rid2=" + rid2);
                }

                Pdu newPdu = null;
                if (rid2.intValue() != rid.intValue())
                {
                    newPdu = getPdu(rid2);
                    if (AsnObject.debug > 3)
                    {
                        System.out.println(getClass().getName() + ".processIncomingResponse(): "
                            + "pduReqId of msgId (" + rid.intValue() 
                            + ") != pduReqId of Pdu (" + rid2.intValue()
                            + ")");
                    }
                    if (newPdu == null)
                    {
                        if (AsnObject.debug > 3)
                        {
                            System.out.println(getClass().getName() + ".processIncomingResponse(): "
                                + "Using pduReqId of msgId (" + rid.intValue() + ")");
                        }
                    }
                }

                if (newPdu != null)
                {
                    pdu = newPdu;
                }
            }
            else
            {
                if (AsnObject.debug > 6)
                {
                    System.out.println(getClass().getName() + ".processIncomingResponse():"
                    + " pduSeq is null.");
                }
            }

            if (pdu != null)
            {
                pdu.fillin(pduSeq);
            }
            else
            {
                if (AsnObject.debug > 6)
                {
                    System.out.println(getClass().getName() + ".processIncomingResponse(): No Pdu with reqid " + rid.intValue());
                }
            }
        }
        catch (DecodingException exc)
        {
            if (pdu != null)
            {
                pdu.setErrorStatus(AsnObject.SNMP_ERR_DECODING_EXC, exc);
                pdu.fillin(null);
            }
            else
            {
                throw exc;
            }
        }
    }
    else
    {
        if (AsnObject.debug > 3)
        {
            System.out.println(getClass().getName() + ".processIncomingResponse(): Pdu of msgId " + msgId 
                + " is already answered");
        }
        rid = new Integer(-1);
    }
}

/**
 * Returns if we send this PDU in authoritative role or not.
 * The engine who sends a Response, a Trapv2 or a Report is
 * authoritative.
 *
 * @since 4_14
 * @return true if authoritative, false if not.
 */
// Note: for when adding INFORM
// When sending an INFORM, the receiver is the authoritative engine, so
// the INFORM does NOT have to be added to this list!
protected boolean isAuthoritative(byte msg_type)
{
    return (msg_type == AsnObject.GET_RSP_MSG
                ||
            msg_type == AsnObject.TRPV2_REQ_MSG
                ||
            msg_type == AsnObject.GET_RPRT_MSG);
}

void discoverIfNeeded()
throws java.io.IOException, PduException
{
    uk.co.westhawk.snmp.beans.UsmDiscoveryBean discBean = null;
    boolean isNeeded = false;

    TimeWindow tWindow = TimeWindow.getCurrent();
    String engineId = tWindow.getSnmpEngineId(getSendToHostAddress(), hostPort);
    if (engineId == null)
    {
        isNeeded = true;
        discBean = new uk.co.westhawk.snmp.beans.UsmDiscoveryBean(
                getSendToHostAddress(), hostPort, bindAddr, typeSocket);
    }

    if (isUseAuthentication())
    {
        if (isNeeded)
        {
            discBean.setAuthenticationDetails(userName,
                userAuthenticationPassword, authenticationProtocol);
        }
        else if (tWindow.isTimeLineKnown(engineId) == false)
        {
            isNeeded = true;
            discBean = new uk.co.westhawk.snmp.beans.UsmDiscoveryBean(
                    getSendToHostAddress(), hostPort, bindAddr, typeSocket);
            discBean.setAuthenticationDetails(userName,
                userAuthenticationPassword, authenticationProtocol);
        }

        if (isNeeded && isUsePrivacy())
        {
            discBean.setPrivacyDetails(userPrivacyPassword);
        }
    }

    if (isNeeded)
    {
        discBean.startDiscovery();

    }

    // If contextEngineId is null or of length zero, set
    // it to the snmpEngineId.
    if (contextEngineId == null || contextEngineId.length == 0)
    {
        engineId = tWindow.getSnmpEngineId(getSendToHostAddress(), hostPort);
        setContextEngineId(SnmpUtilities.toBytes(engineId));
    }
}


/**
 * Adds the specified request pdu listener to receive PDUs on the
 * specified listening context that matches this context.
 * This method will call usmAgent.setSnmpContext(this).
 *
 * <p>
 * Don't use the TCP_SOCKET when listening for request PDUs. It doesn't
 * provide functionality to send a response back. 
 * </p>
 *
 * @see AbstractSnmpContext#addRequestPduListener(RequestPduListener, ListeningContextPool)
 *
 * @param l The request PDU listener 
 * @param lcontext The listening context
 */
public void addRequestPduListener(RequestPduListener l, ListeningContextPool lcontext)
throws java.io.IOException
{
    super.addRequestPduListener(l, lcontext);

    usmAgent.setSnmpContext(this);
    TimeWindow tWindow = TimeWindow.getCurrent();
    if (usmAgent.getSnmpEngineId() == null)
    {
        throw new IOException("UsmAgent "
            + usmAgent.getClass().getName() 
            + " should provide Engine ID!");
    }
    tWindow.setSnmpEngineId(usmAgent.MYFAKEHOSTNAME, hostPort, usmAgent.getSnmpEngineId());
    tWindow.updateTimeWindow(usmAgent.getSnmpEngineId(),
        usmAgent.getSnmpEngineBoots(), usmAgent.getSnmpEngineTime(),
        this.isUseAuthentication());
}



/**
 * Copies all parameters into another SnmpContextv3.
 */
public Object cloneParameters(SnmpContextv3Face clContext) 
{
    clContext.setUserName(new String(userName));
    clContext.setUseAuthentication(useAuthentication);
    if (userAuthenticationPassword != null)
    {
        clContext.setUserAuthenticationPassword(
            new String(userAuthenticationPassword));
    }
    clContext.setAuthenticationProtocol(authenticationProtocol);
    clContext.setUsePrivacy(usePrivacy);
    if (userPrivacyPassword != null)
    {
        clContext.setUserPrivacyPassword(new String(userPrivacyPassword));
    }

    clContext.setContextName(new String(contextName));

    int l = contextEngineId.length;
    byte[] newContextEngineId = new byte[l];
    System.arraycopy(contextEngineId, 0, newContextEngineId, 0, l);  
    clContext.setContextEngineId(newContextEngineId);

    clContext.setUsmAgent(usmAgent);
    return clContext;
}

/**
 * Returns the hash key. This key is built out of all properties. It
 * serves as key for a hashtable of (v3) contexts.
 *
 * @since 4_14
 * @return The hash key
 */
public String getHashKey()
{
    StringBuffer buffer = new StringBuffer();
    buffer.append(hostname);
    buffer.append("_").append(hostPort);
    buffer.append("_").append(bindAddr);
    buffer.append("_").append(typeSocket);
    buffer.append("_").append(useAuthentication);
    buffer.append("_").append(authenticationProtocol);
    buffer.append("_").append(userAuthenticationPassword);
    buffer.append("_").append(userName);
    buffer.append("_").append(usePrivacy);
    buffer.append("_").append(userPrivacyPassword);
    buffer.append("_").append(SnmpUtilities.toHexString(contextEngineId));
    buffer.append("_").append(contextName);
    buffer.append("_v").append(getVersion());

    return buffer.toString();
}

/**
 * Returns a string representation of the object.
 * @return The string
 */
public String toString()
{
    StringBuffer buffer = new StringBuffer(getClass().getName() + "[");
    buffer.append("host=").append(hostname);
    buffer.append(", sendToHost=").append(getSendToHostAddress());
    buffer.append(", port=").append(hostPort);
    buffer.append(", bindAddress=").append(bindAddr);
    buffer.append(", socketType=").append(typeSocket);
    buffer.append(", contextEngineId=").append(SnmpUtilities.toHexString(contextEngineId));
    buffer.append(", contextName=").append(contextName);
    buffer.append(", userName=").append(userName);
    buffer.append(", useAuthentication=").append(useAuthentication);
    buffer.append(", authenticationProtocol=").append(ProtocolNames[authenticationProtocol]);
    buffer.append(", userAuthenticationPassword=").append(userAuthenticationPassword);
    buffer.append(", usePrivacy=").append(usePrivacy);
    buffer.append(", userPrivacyPassword=").append(userPrivacyPassword);
    buffer.append(", #trapListeners=").append(trapSupport.getListenerCount());
    buffer.append(", #pduListeners=").append(pduSupport.getListenerCount());
    buffer.append("]");
    return buffer.toString();
}

}