org.jscsi.parser.text.TextRequestParser 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.text;
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;
/**
* TextRequestParser
*
* This class parses a Text Request message defined in the iSCSI Standard (RFC3720).
*
* @author Volker Wildi
*/
public final class TextRequestParser extends InitiatorMessageParser {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** Continue Flag. */
private boolean continueFlag;
/** Target Transfer Tag. */
private int targetTransferTag;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Default constructor, creates a new, empty TextRequestParser object.
*
* @param initProtocolDataUnit The reference ProtocolDataUnit instance, which contains this
* TextRequestParser subclass object.
*/
public TextRequestParser (final ProtocolDataUnit initProtocolDataUnit) {
super(initProtocolDataUnit);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
public final String toString () {
final StringBuilder sb = new StringBuilder(Constants.LOG_INITIAL_SIZE);
Utils.printField(sb, "Continue Flag", continueFlag, 1);
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.TEXT;
}
/** {@inheritDoc} */
@Override
public final void clear () {
super.clear();
continueFlag = false;
targetTransferTag = 0x00000000;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Sets the Target Transfer Tag to a new one.
*
* @param newTargetTransferTag The new Target Transfer Tag.
* @see #getTargetTransferTag()
*/
public final void setTargetTransferTag (final int newTargetTransferTag) {
targetTransferTag = newTargetTransferTag;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* When set to 1, indicates that the text (set of key=value pairs) in this Text Request is not complete
* (it will be continued on subsequent Text Requests); otherwise, it indicates that this Text Request ends a set of
* key=value pairs. A Text Request with the C bit set to 1 MUST have the F bit set to
* 0.
*
* @return True, if the Continue Flag is set. Else false.
*/
public final boolean isContinueFlag () {
return continueFlag;
}
/**
* When the Target Transfer Tag is set to the reserved value 0xffffffff, it tells the target
* that this is a new request and the target resets any internal state associated with the Initiator Task Tag
* (resets the current negotiation state). The target sets the Target Transfer Tag in a text response to a value
* other than the reserved value 0xffffffff whenever it indicates that it has more data to send or more
* operations to perform that are associated with the specified Initiator Task Tag. It MUST do so whenever it sets
* the F bit to 0 in the response. By copying the Target Transfer Tag from the response to
* the next Text Request, the initiator tells the target to continue the operation for the specific Initiator Task
* Tag. The initiator MUST ignore the Target Transfer Tag in the Text Response when the F bit is set to
* 1. This mechanism allows the initiator and target to transfer a large amount of textual data over a
* sequence of text-command/text-response exchanges, or to perform extended negotiation sequences. If the Target
* Transfer Tag is not 0xffffffff, the LUN field MUST be sent by the target in the Text
* Response.
*
* A target MAY reset its internal negotiation state if an exchange is stalled by the initiator for a long time or
* if it is running out of resources. Long text responses are handled as in the following example: I->T Text
* SendTargets=All (F=1,TTT=0xffffffff) T->I Text <part 1> (F=0,TTT=0x12345678) I->T Text <empty> (F=1,
* TTT=0x12345678) T->I Text <part 2> (F=0, TTT=0x12345678) I->T Text <empty> (F=1, TTT=0x12345678) ...
* T->I Text <part n> (F=1, TTT=0xffffffff)
*
* @return The Target Transfer Tag of this TextRequestParser object.
*/
public final int getTargetTransferTag () {
return targetTransferTag;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final void deserializeBytes1to3 (final int line) throws InternetSCSIException {
continueFlag = Utils.isBitSet(line & Constants.CONTINUE_FLAG_MASK);
Utils.isReserved(line & ~Constants.CONTINUE_FLAG_MASK);
}
/** {@inheritDoc} */
@Override
protected final void deserializeBytes20to23 (final int line) throws InternetSCSIException {
targetTransferTag = line;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final void checkIntegrity () throws InternetSCSIException {
String exceptionMessage;
do {
if (protocolDataUnit.getBasicHeaderSegment().isFinalFlag() && continueFlag) {
exceptionMessage = "Final and Continue Flag cannot be set at the same time.";
break;
}
// message is checked correctly
return;
} while (false);
throw new InternetSCSIException(exceptionMessage);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected final int serializeBytes1to3 () {
int line = 0;
if (continueFlag) {
line |= Constants.CONTINUE_FLAG_MASK;
}
return line;
}
/** {@inheritDoc} */
@Override
protected final int serializeBytes20to23 () {
return targetTransferTag;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
}