Examples of org.jscsi.parser.nop.NOPOutParser

org.jscsi.parser.nop.NOPOutParser

NOPOutParser

This class parses a NOP-Out message defined in the iSCSI Standard (RFC3720).
A NOP-Out may be used by an initiator as a "ping request" to verify that a connection/session is still active and all its components are operational. The NOP-In response is the "ping echo".
A NOP-Out is also sent by an initiator in response to a NOP-In.
A NOP-Out may also be used to confirm a changed ExpStatSN if another PDU will not be available for a long time.
Upon receipt of a NOP-In with the Target Transfer Tag set to a valid value (not the reserved 0xffffffff ), the initiator MUST respond with a NOP-Out. In this case, the NOP-Out Target Transfer Tag MUST contain a copy of the NOP-In Target Transfer Tag.
These fields have these specific meanings:
Initiator Task Tag:
The NOP-Out MUST have the Initiator Task Tag set to a valid value only if a response in the form of NOP-In is requested (i.e., the NOP-Out is used as a ping request). Otherwise, the Initiator Task Tag MUST be set to 0xffffffff.
When a target receives the NOP-Out with a valid Initiator Task Tag, it MUST respond with a Nop-In Response (see Section 10.19 NOP-In).
If the Initiator Task Tag contains 0xffffffff, the I bit MUST be set to 1 and the CmdSN is not advanced after this PDU is sent.
Ping Data
Ping data are reflected in the NOP-In Response. The length of the reflected data are limited to MaxRecvDataSegmentLength. The length of ping data are indicated by the DataSegmentLength. 0 is a valid value for the DataSegmentLength and indicates the absence of ping data.
@author Volker Wildi


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


        final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();
        final NOPOutParser parser = (NOPOutParser) bhs.getParser();


        if (parser.getTargetTransferTag() != RESERVED_TAG_VALUE) {
            /*
             * This is an error. The jSCSI Target does not send NOP-In ping messages, which would be the only legal
             * reason for the initiator sending a NOP-Out with the TargetTransferTag equal to 0xffffffff. And even if
             * the jSCSI Target was sending pings, the echo would be processed in a dedicated stage. Therefore, we treat
             * this as an error. Close the connection.
             */
            throw new InternetSCSIException("NOP-Out PDU TargetTransferTag = " + parser.getTargetTransferTag() + " in PingStage");
        }


        // decide whether or not response is necessary
        if (bhs.getInitiatorTaskTag() == RESERVED_TAG_VALUE) return;// send no response


        // else
        // prepare response data segment (copy up to initiator's
        // MaxRecvDataSegmentLength)
        final int dataSegmentLength = Math.min(pdu.getDataSegment().capacity(), settings.getMaxRecvDataSegmentLength());
        final ByteBuffer responseDataSegment = ByteBuffer.allocate(dataSegmentLength);
        responseDataSegment.put(pdu.getDataSegment().array(),// source array,
                0,// offset within the array of the first byte to be read
                dataSegmentLength);// length


        // send response
        final ProtocolDataUnit responsePdu = TargetPduFactory.createNopInPDU(0,// logicalUnitNumber,
                                                                               // reserved
                bhs.getInitiatorTaskTag(),// initiatorTaskTag
                RESERVED_TAG_VALUE,// targetTransferTag
                responseDataSegment, parser.getExpectedStatusSequenceNumber());
        connection.sendPdu(responsePdu);
    }

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            case SCSI_DATA_OUT :
                return new DataOutParser(protocolDataUnit);
            case SCSI_DATA_IN :
                return new DataInParser(protocolDataUnit);
            case NOP_OUT :
                return new NOPOutParser(protocolDataUnit);
            case NOP_IN :
                return new NOPInParser(protocolDataUnit);
            case R2T :
                return new Ready2TransferParser(protocolDataUnit);
            case REJECT :

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Related Classes of org.jscsi.parser.nop.NOPOutParser

org.jscsi.parser.MessageParserFactory

org.jscsi.target.connection.stage.fullfeature.PingStage

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