org.jscsi.parser.nop.NOPOutParser Maven / Gradle / Ivy
/**
* Copyright (c) 2012, University of Konstanz, Distributed Systems Group All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or other materials provided with the
* distribution. * Neither the name of the University of Konstanz nor the names of its contributors may be used to
* endorse or promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jscsi.parser.nop;
import org.jscsi.exception.InternetSCSIException;
import org.jscsi.parser.Constants;
import org.jscsi.parser.InitiatorMessageParser;
import org.jscsi.parser.ProtocolDataUnit;
import org.jscsi.parser.datasegment.DataSegmentFactory.DataSegmentFormat;
import org.jscsi.utils.Utils;
/**
* 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
*/
public final class NOPOutParser extends InitiatorMessageParser {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** The TargetTransferTag. */
protected int targetTransferTag;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Default constructor, creates a new, empty NOPOutParser object.
*
* @param initProtocolDataUnit The reference ProtocolDataUnit instance, which contains this
* NOPOutParser subclass object.
*/
public NOPOutParser (final ProtocolDataUnit initProtocolDataUnit) {
super(initProtocolDataUnit);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* A target assigned identifier for the operation.
*
* The NOP-Out MUST only have the Target Transfer Tag set if it is issued in response to a NOP-In with a valid
* Target Transfer Tag. In this case, it copies the Target Transfer Tag from the NOP-In PDU. Otherwise, the Target
* Transfer Tag MUST be set to 0xffffffff.
*
* When the Target Transfer Tag is set to a value other than 0xffffffff, the LUN field MUST also be
* copied from the NOP-In.
*
* @return The target transfer tag of this object.
*/
public final int getTargetTransferTag () {
return targetTransferTag;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
public final String toString () {
final StringBuilder sb = new StringBuilder(Constants.LOG_INITIAL_SIZE);
Utils.printField(sb, "LUN", logicalUnitNumber, 1);
Utils.printField(sb, "Target Transfer Tag", targetTransferTag, 1);
sb.append(super.toString());
return sb.toString();
}
/** {@inheritDoc} */
@Override
public final DataSegmentFormat getDataSegmentFormat () {
return DataSegmentFormat.BINARY;
}
/** {@inheritDoc} */
@Override
public final void clear () {
super.clear();
targetTransferTag = 0x00000000;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final void deserializeBytes1to3 (final int line) throws InternetSCSIException {
Utils.isReserved(line & Constants.LAST_THREE_BYTES_MASK);
}
/** {@inheritDoc} */
@Override
protected final void deserializeBytes20to23 (final int line) throws InternetSCSIException {
targetTransferTag = line;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final void checkIntegrity () throws InternetSCSIException {
// do nothing...
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final int serializeBytes20to23 () {
return targetTransferTag;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
}