package org.jscsi.target.connection.stage.fullfeature;

 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.parser.scsi.SCSIResponseParser;

 import org.jscsi.parser.scsi.SCSIStatus;

 import org.jscsi.target.connection.TargetPduFactory;

 import org.jscsi.target.connection.phase.TargetFullFeaturePhase;

 import org.jscsi.target.scsi.ScsiResponseDataSegment;

 import org.jscsi.target.scsi.cdb.FormatUnitCDB;

 import org.jscsi.target.scsi.sense.AdditionalSenseBytes;

 import org.jscsi.target.scsi.sense.AdditionalSenseCodeAndQualifier;

 import org.jscsi.target.scsi.sense.ErrorType;

 import org.jscsi.target.scsi.sense.FixedFormatSenseData;

 import org.jscsi.target.scsi.sense.SenseKey;

 import org.jscsi.target.scsi.sense.information.FourByteInformation;

 import org.jscsi.target.scsi.sense.senseDataDescriptor.senseKeySpecific.FieldPointerSenseKeySpecificData;

 import org.jscsi.target.settings.SettingsException;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A stage for processing <code>FORMAT UNIT</code> SCSI commands.

  * <p>

  * The <code>FORMAT UNIT</code> command requests that the device server format the medium into application client

  * accessible logical blocks as specified in the number of logical blocks and logical block length values received in

  * the last mode parameter block descriptor in a <code>MODE SELECT</code> command (see SPC-4). In addition, the device

  * server may certify the medium and create control structures for the management of the medium and defects.

  * <p>

  * The degree that the medium is altered by this command is vendor specific.

  * <p>

  * If a device server receives a <code>FORMAT UNIT</code> command before receiving a MODE SELECT command with a mode

  * parameter block descriptor, then the device server shall use the number of logical blocks and logical block length at

  * which the logical unit is currently formatted (i.e., no change is made to the number of logical blocks and the

  * logical block length of the logical unit during the format operation).

  * <p>

  * <code>FORMAT UNIT</code> commands received by the jSCI Target will not lead to any persistent changes of the virtual

  * logical unit.

  * 

  * @author Andreas Ergenzinger

  */

 public class FormatUnitStage extends TargetFullFeatureStage {

     private static final Logger LOGGER = LoggerFactory.getLogger(ReadStage.class);

     public FormatUnitStage (TargetFullFeaturePhase targetFullFeaturePhase) {

         super(targetFullFeaturePhase);

     }

     @Override

     public void execute (ProtocolDataUnit pdu) throws IOException , InterruptedException , InternetSCSIException , DigestException , SettingsException {

         LOGGER.debug("Initiator has sent FORMAT UNIT command.");

         final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

         final SCSICommandParser parser = (SCSICommandParser) bhs.getParser();

         ProtocolDataUnit responsePdu = null;// the response PDU

         // get command details in CDB

         final FormatUnitCDB cdb = new FormatUnitCDB(parser.getCDB());

         final FieldPointerSenseKeySpecificData[] illegalFieldPointers = cdb.getIllegalFieldPointers();

         if (illegalFieldPointers != null) {

             // an illegal request has been made

             FixedFormatSenseData senseData = new FixedFormatSenseData(false,// valid

             ErrorType.CURRENT,// error type

             false,// file mark

             false,// end of medium

             false,// incorrect length indicator

             SenseKey.ILLEGAL_REQUEST,// sense key

             new FourByteInformation(),// information

             new FourByteInformation(),// command specific information

             AdditionalSenseCodeAndQualifier.INVALID_FIELD_IN_CDB,// additional

                                                                  // sense

                                                                  // code

                                                                  // and

                                                                  // qualifier

             (byte) 0,// field replaceable unit code

             illegalFieldPointers[0],// sense key specific data, only

                                     // report first problem

             new AdditionalSenseBytes());// additional sense bytes

             responsePdu = TargetPduFactory.createSCSIResponsePdu(false,// bidirectionalReadResidualOverflow

                     false,// bidirectionalReadResidualUnderflow

                     false,// residualOverflow

                     false,// residualUnderflow,

                     SCSIResponseParser.ServiceResponse.COMMAND_COMPLETED_AT_TARGET,// response,

                     SCSIStatus.CHECK_CONDITION,// status,

                     bhs.getInitiatorTaskTag(),// initiatorTaskTag,

                     0,// snackTag

                     0,// expectedDataSequenceNumber

                     0,// bidirectionalReadResidualCount

                     0,// residualCount

                     new ScsiResponseDataSegment(senseData, parser.getExpectedDataTransferLength()));// data

                                                                                                     // segment

         } else {

             // PDU is okay

             // carry out command

             /*

              * If we were nice, we would have to get (we would actually have to save it first) the number of blocks and

              * the block length requested by the initiator in the last MODE SENSE command and then change the logical

              * block layout accordingly. However, since the target is not required by the SCSI standard to make those

              * changes ("The degree that the medium is altered by this command is vendor specific."), doing nothing is

              * okay.

              */

             responsePdu = createScsiResponsePdu(SCSIStatus.GOOD,// status

                     bhs.getInitiatorTaskTag(),// initiatorTaskTag,

                     parser.getExpectedDataTransferLength(),// expectedDataTransferLength,

                     0);// responseDataSize

         }

         // send response

         connection.sendPdu(responsePdu);

     }

 }