package org.jscsi.target.connection.stage.fullfeature;
   
   
   import static org.jscsi.target.storage.IStorageModule.VIRTUAL_BLOCK_SIZE;
   
   import java.io.IOException;
   import java.security.DigestException;
   
   import org.jscsi.exception.InternetSCSIException;
  import org.jscsi.parser.BasicHeaderSegment;
  import org.jscsi.parser.ProtocolDataUnit;
  import org.jscsi.parser.scsi.SCSICommandParser;
  import org.jscsi.target.connection.phase.TargetFullFeaturePhase;
  import org.jscsi.target.scsi.cdb.ReadCapacity10Cdb;
  import org.jscsi.target.scsi.cdb.ReadCapacity16Cdb;
  import org.jscsi.target.scsi.cdb.ReadCapacityCdb;
  import org.jscsi.target.scsi.cdb.ScsiOperationCode;
  import org.jscsi.target.scsi.readCapacity.ReadCapacity10ParameterData;
  import org.jscsi.target.scsi.readCapacity.ReadCapacity16ParameterData;
  import org.jscsi.target.scsi.readCapacity.ReadCapacityParameterData;
  import org.jscsi.target.scsi.sense.AdditionalSenseCodeAndQualifier;
  import org.jscsi.target.scsi.sense.senseDataDescriptor.senseKeySpecific.FieldPointerSenseKeySpecificData;
  import org.jscsi.target.settings.SettingsException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  public final class ReadCapacityStage extends TargetFullFeatureStage {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(ReadCapacityStage.class);
  
      public ReadCapacityStage (final TargetFullFeaturePhase targetFullFeaturePhase) {
          super(targetFullFeaturePhase);
      }
  
      @Override
      public void execute (ProtocolDataUnit pdu) throws IOException , InterruptedException , InternetSCSIException , DigestException , SettingsException {
  
          // find out the type of READ CAPACITY command ((10) or (16))
          final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();
          final SCSICommandParser parser = (SCSICommandParser) bhs.getParser();
          final ScsiOperationCode opCode = ScsiOperationCode.valueOf(parser.getCDB().get(0));
          ReadCapacityCdb cdb;
          if (opCode == ScsiOperationCode.READ_CAPACITY_10)
              cdb = new ReadCapacity10Cdb(parser.getCDB());
          else if (opCode == ScsiOperationCode.READ_CAPACITY_16)
              cdb = new ReadCapacity16Cdb(parser.getCDB());
          else {
              // programmer error, we should not be here, close the connection
              throw new InternetSCSIException("wrong SCSI Operation Code " + opCode + " in ReadCapacityStage");
          }
  
          /*
           * Everything is fine, carry on. The PMI bit of the command descriptor block is ignored, since there is no way
           * to know if "substantial vendor specific delay in data transfer may be encountered" after the address in the
           * LOGICAL BLOCK ADDRESS field. Therefore we always try to return the whole length of the storage medium.
           */
  
          // make sure that the LOGICAL BLOCK ADDRESS field is valid and send
          // appropriate response
          if (session.getStorageModule().checkBounds(cdb.getLogicalBlockAddress(), 0) != 0) {
              // invalid, log error, send error PDU, and return
              LOGGER.error("encountered " + cdb.getClass() + " in ReadCapacityStage with " + "LOGICAL BLOCK ADDRESS = " + cdb.getLogicalBlockAddress());
  
              final FieldPointerSenseKeySpecificData fp = new FieldPointerSenseKeySpecificData(true,// senseKeySpecificDataValid
              true,// commandData (i.e. invalid field in CDB)
              false,// bitPointerValid
              0,// bitPointer, reserved since invalid
              0);// fieldPointer to the SCSI OpCode field
              final FieldPointerSenseKeySpecificData[] fpArray = new FieldPointerSenseKeySpecificData[] { fp };
              final ProtocolDataUnit responsePdu = createFixedFormatErrorPdu(fpArray,// senseKeySpecificData
                      AdditionalSenseCodeAndQualifier.LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,// additionalSenseCodeAndQualifier
                      bhs.getInitiatorTaskTag(),// initiatorTaskTag
                      parser.getExpectedDataTransferLength());// expectedDataTransferLength
              connection.sendPdu(responsePdu);
              return;
          } else {
              // send PDU with requested READ CAPACITY parameter data
              ReadCapacityParameterData parameterData;
              if (cdb instanceof ReadCapacity10Cdb)
                  parameterData = new ReadCapacity10ParameterData(session.getStorageModule().getSizeInBlocks(),// returnedLogicalBlockAddress
                  VIRTUAL_BLOCK_SIZE);// logicalBlockLengthInBytes
              else
                  parameterData = new ReadCapacity16ParameterData(session.getStorageModule().getSizeInBlocks(),// returnedLogicalBlockAddress
                  VIRTUAL_BLOCK_SIZE);// logicalBlockLengthInBytes
  
              sendResponse(bhs.getInitiatorTaskTag(),// initiatorTaskTag,
                      parser.getExpectedDataTransferLength(),// expectedDataTransferLength,
                      parameterData);// responseData
          }
      }
  
  }