snmprequesthandler.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

            
                case SnmpPduPacket.pduGetBulkRequestPdu:
                    respPdu = makeGetBulkResponsePdu((SnmpPduBulk)reqPdu,
                                                     userData) ;
                    break ;
                }
            }
            else { // reqPdu is rejected by ACLs
                // respPdu contains the error response to be sent.
                // We send this response only if authResEnabled is true.
                if (!snmpServer.getAuthRespEnabled()) { // No response should be sent
                    respPdu = null ;
                }
                if (snmpServer.getAuthTrapEnabled()) { // A trap must be sent
                    try {
                        snmpServer.snmpV1Trap(SnmpPduTrap.
					      trapAuthenticationFailure, 0, 
					      new SnmpVarBindList()) ;
                    }
                    catch(Exception x) {
                        if (isDebugOn()) {
                            debug("makeResponsePdu", 
				  "failure when sending authentication trap");
                            debug("makeResponsePdu", x);
                        }
                    }
                }
            }
        }
        return respPdu ;
    }
  
    //
    // Generates a response packet, filling the values in the
    // varbindlist with one of endOfMibView, noSuchObject, noSuchInstance
    // according to the value of <code>status</code>
    // 
    // @param statusTag should be one of:
    //        <li>SnmpDataTypeEnums.errEndOfMibViewTag</li>
    //        <li>SnmpDataTypeEnums.errNoSuchObjectTag</li>
    //        <li>SnmpDataTypeEnums.errNoSuchInstanceTag</li>
    //
    SnmpPduPacket makeErrorVarbindPdu(SnmpPduPacket req, int statusTag) {

        final SnmpVarBind[] vblist = req.varBindList;
        final int length = vblist.length;

        switch (statusTag) {
        case SnmpDataTypeEnums.errEndOfMibViewTag:
            for (int i=0 ; i<length ; i++) 
                vblist[i].value = SnmpVarBind.endOfMibView;
            break;
        case SnmpDataTypeEnums.errNoSuchObjectTag:
            for (int i=0 ; i<length ; i++) 
                vblist[i].value = SnmpVarBind.noSuchObject;
            break;
        case SnmpDataTypeEnums.errNoSuchInstanceTag:
            for (int i=0 ; i<length ; i++) 
                vblist[i].value = SnmpVarBind.noSuchInstance;
            break;
        default:
            return newErrorResponsePdu(req,snmpRspGenErr,1);
        }
        return newValidResponsePdu(req,vblist);
    }

    // Generates an appropriate response when no mib is registered in
    // the adaptor.
    //
    // <li>If the version is V1:</li>
    // <ul><li>Generates a NoSuchName error V1 response PDU</li></ul>
    // <li>If the version is V2:</li>
    // <ul><li>If the request is a GET, fills the varbind list with
    //         NoSuchObject's</li>
    //     <li>If the request is a GET-NEXT/GET-BULK, fills the varbind 
    //         list with EndOfMibView's</li>
    //     <li>If the request is a SET, generates a NoAccess error V2 
    //          response PDU</li>
    // </ul>
    // 
    //
    SnmpPduPacket makeNoMibErrorPdu(SnmpPduRequest req, Object userData) {
        // There is no agent registered
        //
        if (req.version == SnmpDefinitions.snmpVersionOne) {
            // Version 1: => NoSuchName
            return 
                newErrorResponsePdu(req,snmpRspNoSuchName,1);
        } else if (req.version == SnmpDefinitions.snmpVersionTwo) {
            // Version 2: => depends on PDU type
            switch (req.type) {
            case pduSetRequestPdu :
            case pduWalkRequest : 
                // SET request => NoAccess
                return 
                    newErrorResponsePdu(req,snmpRspNoAccess,1);
            case pduGetRequestPdu : 
                // GET request => NoSuchObject
                return 
                    makeErrorVarbindPdu(req,SnmpDataTypeEnums.
					errNoSuchObjectTag);
            case pduGetNextRequestPdu :
            case pduGetBulkRequestPdu : 
                // GET-NEXT or GET-BULK => EndOfMibView
                return 
                    makeErrorVarbindPdu(req,SnmpDataTypeEnums.
					errEndOfMibViewTag);
            default:
            }
        }
        // Something wrong here: => snmpRspGenErr
        return newErrorResponsePdu(req,snmpRspGenErr,1);
    }

    /**
     * Here we make the response pdu from a get/set request pdu.
     * At this level, the result is never null.
     */
    private SnmpPduPacket makeGetSetResponsePdu(SnmpPduRequest req,
                                                Object userData) {
   
        // Create the trhead group specific for handling sub-requests 
	// associated to the current request. Use the invoke id
        //
        // Nice idea to use a thread group on a request basis. 
	// However the impact on performance is terrible !
        // theGroup= new ThreadGroup(thread.getThreadGroup(), 
	//                "request " + String.valueOf(req.requestId));
	
        // Let's build the varBindList for the response pdu
        //
   
        if (req.varBindList == null) {
            // Good ! Let's make a full response pdu.
            //
            return newValidResponsePdu(req, null) ;
        }

        // First we need to split the request into subrequests
        //
        splitRequest(req);
        int nbSubRequest= subs.size();
        if (nbSubRequest == 1)
            return turboProcessingGetSet(req,userData);
  
    
        // Execute all the subrequests resulting from the split of the 
	// varbind list.
        //
        SnmpPduPacket result= executeSubRequest(req,userData);
        if (result != null)
            // It means that an error occured. The error is already 
	    // formatted by the executeSubRequest
            // method.
            return result;
        
        // So far so good. So we need to concatenate all the answers.
        //
        if (isTraceOn()) {
            trace("makeGetSetResponsePdu", 
		  "Build the unified response for request " + req.requestId);
        }
        return mergeResponses(req);
    }
  
    /**
     * The method runs all the sub-requests associated to the current 
     * instance of SnmpRequestHandler.
     */
    private SnmpPduPacket executeSubRequest(SnmpPduPacket req,
                                            Object userData) {
    
        int errorStatus = SnmpDefinitions.snmpRspNoError ;
        int nbSubRequest= subs.size();
            
	int i=0;
        // If it's a set request, we must first check any varBind
        //
        if (req.type == pduSetRequestPdu) {
     
	    i=0;
            for(Enumeration e= subs.elements(); e.hasMoreElements() ; i++) {
                // Indicate to the sub request that a check must be invoked ...
                // OK we should have defined out own tag for that !
                //
                SnmpSubRequestHandler sub= (SnmpSubRequestHandler) 
		    e.nextElement();
                sub.setUserData(userData);
                sub.type= pduWalkRequest;

		sub.run();

		sub.type= pduSetRequestPdu;

		if (sub.getErrorStatus() != SnmpDefinitions.snmpRspNoError) {
		    // No point to go any further.
		    //
		    if (isDebugOn()) {
			debug("executeSubRequest", "an error occurs");
		    }

		    return newErrorResponsePdu(req, errorStatus, 
					       sub.getErrorIndex() + 1) ;
		}
            }
        }// end processing check operation for a set PDU.
    
        // Let's start the sub-requests.
        // 
	i=0;
        for(Enumeration e= subs.elements(); e.hasMoreElements() ;i++) {
            SnmpSubRequestHandler sub= (SnmpSubRequestHandler) e.nextElement();
        /* NPCTE fix for bugId 4492741, esc 0, 16-August 2001 */ 
	    sub.setUserData(userData);
	/* end of NPCTE fix for bugId 4492741 */      

	    sub.run();

            if (sub.getErrorStatus() != SnmpDefinitions.snmpRspNoError) {
                // No point to go any further.
                //
                if (isDebugOn()) {
                    debug("executeSubRequest", "an error occurs");
                }

                return newErrorResponsePdu(req, errorStatus, 
					   sub.getErrorIndex() + 1) ;
            }
	}
    
        // everything is ok
        //
        return null;
    }
  
    /**
     * Optimize when there is only one sub request
     */
    private SnmpPduPacket turboProcessingGetSet(SnmpPduRequest req,
                                                Object userData) {
  
        int errorStatus = SnmpDefinitions.snmpRspNoError ;
        SnmpSubRequestHandler sub= (SnmpSubRequestHandler) 
	    subs.elements().nextElement();
        sub.setUserData(userData);

        // Indicate to the sub request that a check must be invoked ...
        // OK we should have defined out own tag for that !
        //
        if (req.type == SnmpDefinitions.pduSetRequestPdu) {
            sub.type= pduWalkRequest;
            sub.run();    
            sub.type= pduSetRequestPdu;
       
            // Check the error status. 
            //
            errorStatus= sub.getErrorStatus();
            if (errorStatus != SnmpDefinitions.snmpRspNoError) {
                // No point to go any further.
                //
                return newErrorResponsePdu(req, errorStatus, 
					   sub.getErrorIndex() + 1) ;
            }
        }
  
        // process the operation
        //
   
        sub.run();
        errorStatus= sub.getErrorStatus();
        if (errorStatus != SnmpDefinitions.snmpRspNoError) {
            // No point to go any further.
            //
            if (isDebugOn()) {
                debug("turboProcessingGetSet", "an error occurs");
            }
            int realIndex= sub.getErrorIndex() + 1;
            return newErrorResponsePdu(req, errorStatus, realIndex) ;
        }
    
        // So far so good. So we need to concatenate all the answers.
        //
    
        if (isTraceOn()) {
            trace("turboProcessingGetSet", 
		  "build the unified response for request " + req.requestId);
        }
        return mergeResponses(req);
    }
  
    /**
     * Here we make the response pdu for a bulk request.
     * At this level, the result is never null.
     */
    private SnmpPduPacket makeGetBulkResponsePdu(SnmpPduBulk req, 
                                                 Object userData) {
   
        SnmpVarBind[] respVarBindList = null ;
    
        // RFC 1905, Section 4.2.3, p14
        int L = req.varBindList.length ;
        int N = Math.max(Math.min(req.nonRepeaters, L), 0) ;
        int M = Math.max(req.maxRepetitions, 0) ;
        int R = L - N ;
    
        if (req.varBindList == null) {
            // Good ! Let's make a full response pdu.
            //
            return newValidResponsePdu(req, null) ;
        }
    
        // Split the request into subrequests.
        //
        splitBulkRequest(req, N, M, R);
        SnmpPduPacket result= executeSubRequest(req,userData);
        if (result != null)
            return result;
    
        respVarBindList= mergeBulkResponses(N + (M * R));

        // Now we remove useless trailing endOfMibView.
        //
        int m2 ; // respVarBindList[m2] item and next are going to be removed
        int t = respVarBindList.length ;
        while ((t > N) && (respVarBindList[t-1].
			   value.equals(SnmpVarBind.endOfMibView))) {
            t-- ;
        }
        if (t == N)
            m2 = N + R ;
        else
            m2 = N + ((t -1 -N) / R + 2) * R ; // Trivial, of course...
        if (m2 < respVarBindList.length) {
            SnmpVarBind[] truncatedList = new SnmpVarBind[m2] ;
            for (int i = 0 ; i < m2 ; i++) {
                truncatedList[i] = respVarBindList[i] ;
            }
            respVarBindList = truncatedList ;
        }

        // Good ! Let's make a full response pdu.
        //
        return newValidResponsePdu(req, respVarBindList) ;
    }
  
    /**
     * Check the type of the pdu: only the get/set/bulk request
     * are accepted.
     */
    private boolean checkPduType(SnmpPduPacket pdu) {

        boolean result = true ;

        switch(pdu.type) {
    
        case SnmpDefinitions.pduGetRequestPdu:
        case SnmpDefinitions.pduGetNextRequestPdu:
        case SnmpDefinitions.pduSetRequestPdu:
        case SnmpDefinitions.pduGetBulkRequestPdu:
            result = true ;
            break;

        default:
            if (isDebugOn()) {
                debug("checkPduType", "cannot respond to this kind of PDU");
            }
            result = false ;
            break;
        }
    
        return result ;
    }
  
    /**
     * Check if the specified pdu is conform to the ACL.
     * This method returns null if the pdu is ok. If not, it returns
     * the response pdu to be replied.
     */
    private SnmpPduPacket checkAcl(SnmpPduPacket pdu) {
        SnmpPduPacket response = null ;
        String community = new String(pdu.community) ;
    
        // We check the pdu type and create an error response if
        // the check failed.