org.snmp4j.smi.VariableBinding Java Examples

public List<SNMPTriple> querySingleSNMPTableByOID(String oid) throws IOException
{
 if(oid == null || oid.isEmpty())return null;
 if(!oid.startsWith("."))oid = "."+oid;
    TableUtils tUtils = new TableUtils(snmp, new DefaultPDUFactory());
    List<TableEvent> events = tUtils.getTable(getTarget(), new OID[]{new OID(oid)}, null, null);

 List<SNMPTriple> snmpList = new ArrayList<SNMPTriple>();
    
    for (TableEvent event : events) {
      if(event.isError()) {
     	 logger.warning(this.address + ": SNMP event error: "+event.getErrorMessage());
     	 continue;
           //throw new RuntimeException(event.getErrorMessage());
      }
      for(VariableBinding vb: event.getColumns()) {
   	   String key = vb.getOid().toString();
   	   String value = vb.getVariable().toString();
   	 snmpList.add(new SNMPTriple(key, "", value));
      }
    }
 return snmpList;
}
 

/**
 * Send PDU to H3C, then waiting response event will be caught by listener.
 *
 * @param snmp
 * @param userTarget
 * @param pdu
 * @throws IOException
 * @throws InterruptedException
 */
private void sendGetPDU(Snmp snmp, UserTarget userTarget, ScopedPDU pdu)
        throws IOException, InterruptedException {

    final CountDownLatch latch = new CountDownLatch(1);
    ResponseListener listener = new ResponseListener() {

        @Override
        public void onResponse(ResponseEvent event) {
            ((Snmp) event.getSource()).cancel(event.getRequest(), this);
            PDU response = event.getResponse();
            PDU request = event.getRequest();
            LOG.debug("[request]: {}", request);

            if (response == null) {
                LOG.error("[ERROR]: response is null");

            } else if (response.getErrorStatus() != 0) {
                LOG.error(String.format("[ERROR]: response status %s, Text: %s",
                        response.getErrorStatus(),
                        response.getErrorStatusText()));
            } else {
                LOG.debug("Received response Success!");
                for (int i = 0; i < response.size(); i++) {
                    VariableBinding vb = response.get(i);
                    LOG.info("{} = {}",
                            vb.getOid(),
                            vb.getVariable());
                }
                LOG.debug("SNMP Async GetList OID finished. ");
                latch.countDown();
            }
        }
    };
    snmp.send(pdu, userTarget, null, listener);
    LOG.debug("async send pdu wait for response...");

    boolean wait = latch.await(3, TimeUnit.SECONDS);
    LOG.debug("latch.await =:" + wait);
}
 

/**
 * Transforms a flow FlowRule object to a variable binding.
 * @param rule FlowRule object
 * @param delete whether it is a delete or edit request
 * @return variable binding
 */
public static VariableBinding fromFlowRule(FlowRule rule, boolean delete) {
    Set<Criterion> criterions = rule.selector().criteria();
    PortNumber inPort = criterions.stream()
            .filter(c -> c instanceof PortCriterion)
            .map(c -> ((PortCriterion) c).port())
            .findAny()
            .orElse(null);
    long input = inPort.toLong();
    List<Instruction> instructions = rule.treatment().immediate();
    PortNumber outPort = instructions.stream()
            .filter(c -> c instanceof Instructions.OutputInstruction)
            .map(c -> ((Instructions.OutputInstruction) c).port())
            .findAny()
            .orElse(null);
    long output = outPort.toLong();
    OID oid = new OID(PORT_PATCH_OID + "." + input);
    Variable var = new UnsignedInteger32(delete ? 0 : output);
    return new VariableBinding(oid, var);
}
 

private boolean setPortTargetPower(PortNumber port, long power) {
    log.debug("Set port{} target power...", port);
    List<VariableBinding> vbs = new ArrayList<>();

    OID voaStateOid = new OID(VOA_STATE_OID + "." + port.toLong());
    Variable voaStateVar = new UnsignedInteger32(VOA_STATE_ABSOLUTE);
    VariableBinding voaStateVb = new VariableBinding(voaStateOid, voaStateVar);
    vbs.add(voaStateVb);

    OID voaLevelOid = new OID(VOA_LEVEL_OID + "." + port.toLong());
    Variable voaLevelVar = new UnsignedInteger32(power);
    VariableBinding voaLevelVb = new VariableBinding(voaLevelOid, voaLevelVar);
    vbs.add(voaLevelVb);

    DeviceId deviceId = handler().data().deviceId();
    try {
        set(handler(), vbs);
    } catch (IOException e) {
        log.error("Error writing ports table for device {} exception {}", deviceId, e);
        return false;
    }
    return true;
}
 

private PortNumber getAddDropPort(int channel, boolean isAddPort) {
    OID oid = new OID(CTRL_CHANNEL_ADD_DROP_PORT_INDEX + (isAddPort ? "1" : "2"));

    for (TreeEvent event : snmp.get(oid)) {
        if (event == null) {
            return null;
        }

        VariableBinding[] varBindings = event.getVariableBindings();

        for (VariableBinding varBinding : varBindings) {
            if (varBinding.getOid().last() == channel) {
                int port = varBinding.getVariable().toInt();
                if (!isAddPort) {
                    port += DROP_PORT_OFFSET;
                }
                return PortNumber.portNumber(port);

            }
        }

    }

    return null;
}
 

private static boolean checkWalkFinished(OID targetOID, PDU pdu, VariableBinding vb) {
    boolean finished = false;
    if (pdu.getErrorStatus() != 0) {
        finished = true;
    } else if (vb.getOid() == null) {
        finished = true;
    } else if (vb.getOid().size() < targetOID.size()) {
        finished = true;
    } else if (targetOID.leftMostCompare(targetOID.size(), vb.getOid()) != 0) {
        finished = true;
    } else if (Null.isExceptionSyntax(vb.getVariable().getSyntax())) {
        finished = true;
    } else if (vb.getOid().compareTo(targetOID) <= 0) {
        finished = true;
    }
    return finished;

}
 

private static boolean checkWalkFinished(OID targetOID, PDU pdu, VariableBinding vb) {
    boolean finished = false;
    if (pdu.getErrorStatus() != 0) {
        finished = true;
    } else if (vb.getOid() == null) {
        finished = true;
    } else if (vb.getOid().size() < targetOID.size()) {
        finished = true;
    } else if (targetOID.leftMostCompare(targetOID.size(), vb.getOid()) != 0) {
        finished = true;
    } else if (Null.isExceptionSyntax(vb.getVariable().getSyntax())) {
        finished = true;
    } else if (vb.getOid().compareTo(targetOID) <= 0) {
        finished = true;
    }
    return finished;

}
 

/**
 * This method is capable of handling multiple OIDs
 * @param oids
 * @return
 * @throws IOException
 */
public Map<OID, String> get(OID oids[]) throws IOException 
{
	PDU pdu = createPDU();
	for (OID oid : oids) {
		pdu.add(new VariableBinding(oid));
	}
	pdu.setType(PDU.GET);
	ResponseEvent event = snmp.send(pdu, getTarget(), null);
	if(event != null) {
		PDU pdu2 = event.getResponse();
		VariableBinding[] binds = pdu2!=null?event.getResponse().toArray():null;
		if(binds!=null)
		{
			Map<OID, String> res = new LinkedHashMap<OID, String>(binds.length);
			for(VariableBinding b: binds)
				res.put(b.getOid(), b.getVariable().toString());
			return res;
		}else return null;
	}
	throw new RuntimeException("GET timed out");
}
 

public List<SNMPTriple> getDiskData(String device) throws IOException {

int index = this.getDiskIndex(device);
if(index<0)
{
	return new ArrayList<SNMPTriple>();
}
logger.fine("Query disk stats for "+index);
PDU pdu = createPDU();
for ( int i=1; i< DISK_TABLE_ENTRIES.length; i++) {
	if(DISK_TABLE_ENTRIES[i].length()==0)continue;
	pdu.add(new VariableBinding(new OID("."+DISK_TABLE_OID+"."+i+"."+index)));
}
pdu.setType(PDU.GET);
Map<String, String> res = new HashMap<String, String>(13);
ResponseEvent event = snmp.send(pdu, getTarget(), null);
if(event != null) {
	VariableBinding[] binds = event.getResponse().toArray();
	for(VariableBinding b: binds)
		res.put(b.getOid().toString(), b.getVariable().toString());
	//logger.info(res.toString());
}		
      List<SNMPTriple> resList = new ArrayList<SNMPTriple>(res.size());
      for(int i=1;i<DISK_TABLE_ENTRIES.length; i++) {
	if(DISK_TABLE_ENTRIES[i].length()==0)continue;
	resList.add(new SNMPTriple("."+DISK_TABLE_OID+"."+i+"."+index, DISK_TABLE_ENTRIES[i], res.get(DISK_TABLE_OID+"."+i+"."+index)));
      }
       return resList;
 }
 

private boolean editConnection(FlowRule rule, boolean delete) {
    List<VariableBinding> vbs = new ArrayList<>();
    vbs.add(fromFlowRule(rule, delete));
    DeviceId deviceId = handler().data().deviceId();
    try {
        set(handler(), vbs);
    } catch (IOException e) {
        log.error("Error writing ports table for device {} exception {}", deviceId, e);
        return false;
    }
    // TODO: check for errors
    return true;
}
 

public static void sendTrapV2(String port) throws IOException {
    PDU trap = new PDU();
    trap.setType(PDU.TRAP);

    OID oid = new OID("1.2.3.4.5");
    trap.add(new VariableBinding(SnmpConstants.snmpTrapOID, oid));
    trap.add(new VariableBinding(SnmpConstants.sysUpTime, new TimeTicks(5000)));
    trap.add(new VariableBinding(SnmpConstants.sysDescr, new OctetString("System Description")));

    // Add Payload
    Variable var = new OctetString("some string");
    trap.add(new VariableBinding(oid, var));

    // Specify receiver
    Address targetaddress = new UdpAddress("127.0.0.1/" + port);
    CommunityTarget target = new CommunityTarget();
    target.setCommunity(new OctetString("public"));
    target.setVersion(SnmpConstants.version2c);
    target.setAddress(targetaddress);

    // Send
    Snmp snmp = new Snmp(new DefaultUdpTransportMapping());
    snmp.send(trap, target, null, null);

    snmp.close();
}
 

private void addOIDs2PDU(List<String> oidList) {
    pdu = new ScopedPDU();
    pdu.setType(PDU.GET);
    for (String oid : oidList) {
        pdu.add(new VariableBinding(new OID(oid)));
    }
}
 

/**
  * Query index for given process name. Note the parameter only provides 128 characters,
  * so it could be difficult for us to differentiate each other if multi processes with same name exist.
  * So we will return this list and use the sum from all processes for our metrics
  * @param process
  * @return
  * @throws IOException
  */
 private List<Integer> getProcessIndexes(String process) throws IOException {
  List<Integer> indexes = new ArrayList<Integer> ();
     if(process == null || process.isEmpty())return indexes;

     TableUtils tUtils = new TableUtils(snmp, new DefaultPDUFactory());
     logger.fine("Query "+this.address+" for process " + process);
      @SuppressWarnings("unchecked")
      List<TableEvent> events = tUtils.getTable(getTarget(), new OID[]{new OID("."+PROCESS_TABLE_OID)}, null, null);

      for (TableEvent event : events) {
        if(event.isError()) {
       	 logger.warning(this.address + ": SNMP event error: "+event.getErrorMessage());
       	 continue;
             //throw new RuntimeException(event.getErrorMessage());
        }
        for(VariableBinding vb: event.getColumns()) {
     	   String key = vb.getOid().toString();
     	   String value = vb.getVariable().toString();
     	   if(process!=null && !process.isEmpty() && !value.equalsIgnoreCase(process))
     		   continue;
     	   if(value!=null)
     	   {
     	       logger.fine("Find process OID entry: "+key);
     	       int index = -1;
     	       String[] strs = key.split("\\.");
     	       try
     	       {
     	    	   index = Integer.parseInt(strs[strs.length-1]);
     	    	   indexes.add(index);
     	       }catch(Exception ex){}
     	   }
        }
      }
      return indexes;
}
 

private Map<Integer, String> getNetIfIndexes(String device) throws IOException {
  Map<Integer, String> ifMaps = new HashMap<Integer, String> ();
		
     TableUtils tUtils = new TableUtils(snmp, new DefaultPDUFactory());
     
     logger.fine("Query "+this.address+" for network interface, excluding lo");
      @SuppressWarnings("unchecked")
      List<TableEvent> events = tUtils.getTable(getTarget(), new OID[]{new OID("."+IF_TABLE_DEVICE_OID)}, null, null);

      for (TableEvent event : events) {
        if(event.isError()) {
       	 logger.warning(this.address + ": SNMP event error: "+event.getErrorMessage());
       	 continue;
             //throw new RuntimeException(event.getErrorMessage());
        }
        for(VariableBinding vb: event.getColumns()) {
     	   String key = vb.getOid().toString();
     	   String value = vb.getVariable().toString();
     	   if(device!=null && !device.isEmpty() && !value.equalsIgnoreCase(device))
     		   continue;
     	   if(value!=null && !value.equalsIgnoreCase("lo"))
     	   {
     	       logger.fine("Find device OID entry: "+key);
     	         int index = -1;
     	         String[] strs = key.split("\\.");
     	         try
     	         {
     	        	 index = Integer.parseInt(strs[strs.length-1]);
     	        	 ifMaps.put(index, value);
     	         }catch(Exception ex){}
     	   }
        }
      }
      return ifMaps;
}
 

private int getAlarmId(TreeEvent treeEvents) {
    VariableBinding[] varBindings = treeEvents.getVariableBindings();
    for (VariableBinding varBinding : varBindings) {
        return varBinding.getVariable().toInt();
    }
    return -1;
}
 

private int getDiskIndex(String device) throws IOException {

      TableUtils tUtils = new TableUtils(snmp, new DefaultPDUFactory());
      
      logger.fine("Query "+this.address+" for disk data: "+device);
       @SuppressWarnings("unchecked")
       List<TableEvent> events = tUtils.getTable(getTarget(), new OID[]{new OID("."+DISK_TABLE_DEVICE_OID)}, null, null);

       for (TableEvent event : events) {
         if(event.isError()) {
        	 logger.warning(this.address + ": SNMP event error: "+event.getErrorMessage());
        	 continue;
              //throw new RuntimeException(event.getErrorMessage());
         }
         for(VariableBinding vb: event.getColumns()) {
      	   String key = vb.getOid().toString();
      	   String value = vb.getVariable().toString();
      	   if(value!=null && value.equals(device))
      	   {
      	       logger.fine("Find device OID entry: "+key);
      	         int index = -1;
      	         String[] strs = key.split("\\.");
      	         try
      	         {
      	        	 index = Integer.parseInt(strs[strs.length-1]);
      	         }catch(Exception ex){}
      	         return index;
      	   }
         }
       }
       return -1;
 }
 

/**
 * Method to construct {@link FlowFile} attributes from a vector of {@link VariableBinding}
 * @param attributes attributes
 * @param vector vector of {@link VariableBinding}
 */
private static void addGetOidValues(Map<String, String> attributes, Object vector) {
    if (vector instanceof Vector) {
        @SuppressWarnings("unchecked")
        Vector<VariableBinding> variables = (Vector<VariableBinding>) vector;
        for (VariableBinding variableBinding : variables) {
            addAttributeFromVariable(variableBinding, attributes);
        }
    }
}
 

/**
 * Method to construct {@link FlowFile} attributes from a vector of {@link VariableBinding}
 * @param attributes attributes
 * @param vector vector of {@link VariableBinding}
 */
private static void addWalkOidValues(Map<String, String> attributes, Object vector) {
    if (vector instanceof VariableBinding[]) {
        VariableBinding[] variables = (VariableBinding[]) vector;
        for (VariableBinding variableBinding : variables) {
            addAttributeFromVariable(variableBinding, attributes);
        }
    }
}
 

/**
 * 获取指定OID的 get
 *
 * @param snmp
 * @param target
 * @param oid
 * @return
 * @throws IOException
 */
public static PDU snmpGet(Snmp snmp, Target target, String oid) throws IOException {
    ScopedPDU pdu = new ScopedPDU();
    pdu.setType(PDU.GET);
    pdu.add(new VariableBinding(new OID(oid)));

    ResponseEvent responseEvent = snmp.send(pdu, target);
    PDU response = responseEvent.getResponse();
    if(response == null){
        log.warn("response null - error:{} peerAddress:{} source:{} request:{}",
                responseEvent.getError(),
                responseEvent.getPeerAddress(),
                responseEvent.getSource(),
                responseEvent.getRequest());
    }
    return response;
}
 

/**
 * 判断传入的PDU是否带有可用的监控数据
 * @param pdu
 * @param index
 * 指定的索引的VariableBinding对象
 * @return
 * true : 可用
 * false : 不可用
 */
public static boolean isValidPDU(PDU pdu,int index){
    if(pdu == null){
        return false;
    }
    VariableBinding vb = pdu.get(index);
    if(vb == null){
        return false;
    }
    String vbResult = vb.toString();
    return !"noSuchInstance".equalsIgnoreCase(vbResult) &&
            !"noSuchObject".equalsIgnoreCase(vbResult) &&
            !"noNextInstance".equalsIgnoreCase(vbResult) &&
            !"endOfView".equalsIgnoreCase(vbResult);
}
 

/**
 * 判断传入的PDU是否带有可用的监控数据(PDU携带的第一个VariableBinding对象)
 * @param pdu
 * @return
 * true : 可用
 * false : 不可用
 */
public static boolean isValidPDU(PDU pdu){
    if(pdu == null){
        return false;
    }
    VariableBinding vb = pdu.get(0);
    if(vb == null){
        return false;
    }
    String vbResult = vb.toString();
    return !"noSuchInstance".equalsIgnoreCase(vbResult) &&
            !"noSuchObject".equalsIgnoreCase(vbResult) &&
            !"noNextInstance".equalsIgnoreCase(vbResult) &&
            !"endOfView".equalsIgnoreCase(vbResult);
}
 

/**
 * Method to construct {@link FlowFile} attributes from a vector of {@link VariableBinding}
 * @param attributes attributes
 * @param vector vector of {@link VariableBinding}
 */
private static void addGetOidValues(Map<String, String> attributes, Object vector) {
    if (vector instanceof Vector) {
        @SuppressWarnings("unchecked")
        Vector<VariableBinding> variables = (Vector<VariableBinding>) vector;
        for (VariableBinding variableBinding : variables) {
            addAttributeFromVariable(variableBinding, attributes);
        }
    }
}
 

private PDU createPDU(SnmpTrapInfo snmpTrapInfo) {
    PDU trap = new PDU();
    trap.setType(PDU.TRAP);

    int alertType = snmpTrapInfo.getAlertType() + 1;
    if (alertType > 0) {
        long sysUpTimeTicks = ManagementFactory.getRuntimeMXBean().getUptime() / 10;
        trap.add(new VariableBinding(SnmpConstants.sysUpTime, new TimeTicks(sysUpTimeTicks)));
        trap.add(new VariableBinding(SnmpConstants.snmpTrapOID, getOID(CsSnmpConstants.TRAPS_PREFIX + alertType)));
        if (snmpTrapInfo.getDataCenterId() != 0) {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.DATA_CENTER_ID), new UnsignedInteger32(snmpTrapInfo.getDataCenterId())));
        }

        if (snmpTrapInfo.getPodId() != 0) {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.POD_ID), new UnsignedInteger32(snmpTrapInfo.getPodId())));
        }

        if (snmpTrapInfo.getClusterId() != 0) {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.CLUSTER_ID), new UnsignedInteger32(snmpTrapInfo.getClusterId())));
        }

        if (snmpTrapInfo.getMessage() != null) {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.MESSAGE), new OctetString(snmpTrapInfo.getMessage())));
        } else {
            throw new CloudRuntimeException(" What is the use of alert without message ");
        }

        if (snmpTrapInfo.getGenerationTime() != null) {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.GENERATION_TIME), new OctetString(snmpTrapInfo.getGenerationTime().toString())));
        } else {
            trap.add(new VariableBinding(getOID(CsSnmpConstants.GENERATION_TIME)));
        }
    } else {
        throw new CloudRuntimeException(" Invalid alert Type ");
    }

    return trap;
}
 

public ResponseEvent getEvent(OID oids[]) throws IOException 
{
	PDU pdu = createPDU();
	for (OID oid : oids) {
		pdu.add(new VariableBinding(oid));
	}
	pdu.setType(PDU.GET);
	ResponseEvent event = snmp.send(pdu, getTarget(), null);
	if(event != null) {
		return event;
	}
	throw new RuntimeException("GET timed out");
}
 

/**
 * 获取指定OID的 get
 *
 * @param snmp
 * @param target
 * @param oid
 * @return
 * @throws IOException
 */
public static PDU snmpGet(Snmp snmp, Target target, String oid) throws IOException {
    ScopedPDU pdu = new ScopedPDU();
    pdu.setType(PDU.GET);
    pdu.add(new VariableBinding(new OID(oid)));

    ResponseEvent responseEvent = snmp.send(pdu, target);
    PDU response = responseEvent.getResponse();
    if(response == null){
        log.warn("response null - error:{} peerAddress:{} source:{} request:{}",
                responseEvent.getError(),
                responseEvent.getPeerAddress(),
                responseEvent.getSource(),
                responseEvent.getRequest());
    }
    return response;
}
 

/**
 * 判断传入的PDU是否带有可用的监控数据
 * @param pdu
 * @param index
 * 指定的索引的VariableBinding对象
 * @return
 * true : 可用
 * false : 不可用
 */
public static boolean isValidPDU(PDU pdu,int index){
    if(pdu == null){
        return false;
    }
    VariableBinding vb = pdu.get(index);
    if(vb == null){
        return false;
    }
    String vbResult = vb.toString();
    return !"noSuchInstance".equalsIgnoreCase(vbResult) &&
            !"noSuchObject".equalsIgnoreCase(vbResult) &&
            !"noNextInstance".equalsIgnoreCase(vbResult) &&
            !"endOfView".equalsIgnoreCase(vbResult);
}
 

/**
 * Method to construct {@link FlowFile} attributes from a vector of {@link VariableBinding}
 * @param attributes attributes
 * @param vector vector of {@link VariableBinding}
 */
private static void addWalkOidValues(Map<String, String> attributes, Object vector) {
    if (vector instanceof VariableBinding[]) {
        VariableBinding[] variables = (VariableBinding[]) vector;
        for (VariableBinding variableBinding : variables) {
            addAttributeFromVariable(variableBinding, attributes);
        }
    }
}
 

/**
 * 判断传入的PDU是否带有可用的监控数据(PDU携带的第一个VariableBinding对象)
 * @param pdu
 * @return
 * true : 可用
 * false : 不可用
 */
public static boolean isValidPDU(PDU pdu){
    if(pdu == null){
        return false;
    }
    VariableBinding vb = pdu.get(0);
    if(vb == null){
        return false;
    }
    String vbResult = vb.toString();
    return !"noSuchInstance".equalsIgnoreCase(vbResult) &&
            !"noSuchObject".equalsIgnoreCase(vbResult) &&
            !"noNextInstance".equalsIgnoreCase(vbResult) &&
            !"endOfView".equalsIgnoreCase(vbResult);
}
 

private List<FlowRule> fetchRules(OID oid, boolean isAdd, PortNumber linePort) {
    List<FlowRule> rules = new LinkedList<>();

    for (TreeEvent event : snmp.get(oid)) {
        if (event == null) {
            continue;
        }

        VariableBinding[] varBindings = event.getVariableBindings();
        for (VariableBinding varBinding : varBindings) {
            CrossConnectCache cache = this.handler().get(CrossConnectCache.class);

            if (varBinding.getVariable().toInt() == IN_SERVICE) {
                int channel = varBinding.getOid().removeLast();

                PortNumber addDropPort = getAddDropPort(channel, isAdd);
                if (addDropPort == null) {
                    continue;
                }

                TrafficSelector selector = DefaultTrafficSelector.builder()
                        .matchInPort(isAdd ? addDropPort : linePort)
                        .add(Criteria.matchOchSignalType(OchSignalType.FIXED_GRID))
                        .add(Criteria.matchLambda(toOchSignal(channel)))
                        .build();
                TrafficTreatment treatment = DefaultTrafficTreatment.builder()
                        .setOutput(isAdd ? linePort : addDropPort)
                        .build();

                // Lookup flow ID and priority
                int hash = Objects.hash(data().deviceId(), selector, treatment);
                Pair<FlowId, Integer> lookup = cache.get(hash);
                if (lookup == null) {
                    continue;
                }

                FlowRule fr = DefaultFlowRule.builder()
                        .forDevice(data().deviceId())
                        .makePermanent()
                        .withSelector(selector)
                        .withTreatment(treatment)
                        .withPriority(lookup.getRight())
                        .withCookie(lookup.getLeft().value())
                        .build();
                rules.add(fr);
            }
        }
    }

    return rules;
}
 

private List<PortNumber> acquirePorts() {
    List<TableEvent> events;
    DeviceId deviceId = handler().data().deviceId();
    List<PortNumber> ports = new ArrayList<>();

    try {
        OID[] columnOIDs = {new OID(OPM_POWER_OID)};
        events = getTable(handler(), columnOIDs);
    } catch (IOException e) {
        log.error("Error reading opm power table for device {} exception {}", deviceId, e);
        return ports;
    }

    if (events == null) {
        log.error("Error reading opm power table for device {}", deviceId);
        return ports;
    }

    for (TableEvent event : events) {
        if (event == null) {
            log.error("Error reading event for device {}", deviceId);
            continue;
        }
        VariableBinding[] columns = event.getColumns();
        if (columns == null) {
            log.error("Error reading columns for device {}", deviceId);
            continue;
        }

        VariableBinding opmColumn = columns[0];
        if (opmColumn == null) {
            continue;
        }

        int port = event.getIndex().last();
        int opm = opmColumn.getVariable().toInt();
        if (opm == 0) {
            continue;
        }

        ports.add(PortNumber.portNumber(port));
    }

    return ports;
}