org.jscsi.parser.nop.NOPInParser 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.ProtocolDataUnit;
import org.jscsi.parser.TargetMessageParser;
import org.jscsi.parser.datasegment.DataSegmentFactory.DataSegmentFormat;
import org.jscsi.utils.Utils;
/**
* NOPInParser
*
* This class parses a NOP-In message defined in the iSCSI Standard (RFC3720).
*
* NOP-In is either sent by a target as a response to a NOP-Out, as a "ping" to an initiator, or as a means to carry a
* changed ExpCmdSN and/or MaxCmdSN if another PDU will not be available for a long time (as
* determined by the target).
*
* When a target receives the NOP-Out with a valid Initiator Task Tag (not the reserved value 0xffffffff),
* it MUST respond with a NOP-In with the same Initiator Task Tag that was provided in the NOP-Out request. It MUST also
* duplicate up to the first MaxRecvDataSegmentLength bytes of the initiator provided Ping Data. For such a
* response, the Target Transfer Tag MUST be 0xffffffff.
*
* Otherwise, when a target sends a NOP-In that is not a response to a Nop-Out received from the initiator, the
* Initiator Task Tag MUST be set to 0xffffffff and the Data Segment MUST NOT contain any data
* (DataSegmentLength MUST be 0).
*
* This fields have these specific meanings:
*
* A LUN MUST be set to a correct value when the Target Transfer Tag is valid (not the reserved value
* 0xffffffff).
*
* The StatSN field will always contain the next StatSN. However, when the Initiator Task Tag is set to
* 0xffffffff, StatSN for the connection is not advanced after this PDU is sent.
*
*
* @author Volker Wildi
*/
public final class NOPInParser extends TargetMessageParser {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** Target Transfer Tag. */
private int targetTransferTag;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Default constructor, creates a new, empty NOPInParser object.
*
* @param initProtocolDataUnit The reference ProtocolDataUnit instance, which contains this
* NOPInParser subclass object.
*/
public NOPInParser (final ProtocolDataUnit initProtocolDataUnit) {
super(initProtocolDataUnit);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* If the target is responding to a NOP-Out, this is set to the reserved value 0xffffffff.
*
* If the target is sending a NOP-In as a Ping (intending to receive a corresponding NOP-Out), this field is set to
* a valid value (not the reserved 0xffffffff).
*
* If the target is initiating a NOP-In without wanting to receive a corresponding NOP-Out, this field MUST hold the
* reserved value of 0xffffffff.
*
* @return The target transfer tag of this object.
*/
public final int getTargetTransferTag () {
return targetTransferTag;
}
/**
* Sets the Target Transfer Tag of this object.
*
* @param targetTransferTag the new Target Transfer Tag.
*/
public final void setTargetTransferTag (final int targetTransferTag) {
this.targetTransferTag = 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;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
}