/**
* 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 <COPYRIGHT HOLDER> 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;
import org.jscsi.exception.InternetSCSIException;
import org.jscsi.utils.Utils;
/**
* <h1>TargetMessageParser</h1>
* <p>
* This abstract class is the base class of all target message parsers defined in the iSCSI Protocol
* (RFC3720). This class defines some methods, which are common in all parsers to simplify the parsing
* process.
*
* @author Volker Wildi
*/
public abstract class TargetMessageParser extends AbstractMessageParser {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** Status Sequence Number. */
protected int statusSequenceNumber;
/** Next Expected Commamd Sequence Number. */
protected int expectedCommandSequenceNumber;
/** Maximum Command Sequence Number. */
protected int maximumCommandSequenceNumber;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Default constructor, creates a new, empty <code>TargetMessageParser</code> object.
*
* @param initProtocolDataUnit
* The reference <code>ProtocolDataUnit</code> instance, which
* contains this <code>TargetMessageParser</code> subclass
* object.
*/
public TargetMessageParser(final ProtocolDataUnit initProtocolDataUnit) {
super(initProtocolDataUnit);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
public String getShortInfo() {
return "<- " + getClass().getSimpleName() + ": statSN: " + getStatusSequenceNumber() + ", expCmdSN: "
+ getExpectedCommandSequenceNumber() + ", maxCmdSN: " + getMaximumCommandSequenceNumber();
}
/** {@inheritDoc} */
@Override
public String toString() {
final StringBuilder sb = new StringBuilder(Constants.LOG_INITIAL_SIZE);
Utils.printField(sb, "StatusSequenceNumber", statusSequenceNumber, 1);
Utils.printField(sb, "ExpectedCommandSequenceNumber", expectedCommandSequenceNumber, 1);
Utils.printField(sb, "MaximumCommandSequenceNumber", maximumCommandSequenceNumber, 1);
return sb.toString();
}
/** {@inheritDoc} */
@Override
public void clear() {
super.clear();
statusSequenceNumber = 0;
expectedCommandSequenceNumber = 0;
maximumCommandSequenceNumber = 0;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* This <code>AbstractMessageParser</code> instance affects the
* incrementation of the <code>Expected Status Sequence Number</code>.
*
* @return <code>true</code>, if the counter has to be incremented. Else <code>false</code>.
*/
@Override
public boolean incrementSequenceNumber() {
return true;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Next Expected Commamd Sequence Number from this Initiator <code>ExpCmdSN</code> is a Sequence Number
* that the target iSCSI returns
* to the initiator to acknowledge command reception. It is used to update a
* local variable with the same name. An <code>ExpCmdSN</code> equal to <code>MaxCmdSN+1</code> indicates
* that the target cannot accept new
* commands.
*
* @return Expected Command Sequence Number.
*/
public final int getExpectedCommandSequenceNumber() {
return expectedCommandSequenceNumber;
}
/**
* Maximum Command Sequence Number from this Initiator <code>MaxCmdSN</code> is a Sequence Number that the
* target iSCSI returns to the initiator to
* indicate the maximum <code>CmdSN</code> the initiator can send. It is
* used to update a local variable with the same name. If <code>MaxCmdSN</code> is equal to
* <code>ExpCmdSN-1</code>, this indicates
* to the initiator that the target cannot receive any additional commands.
* When <code>MaxCmdSN</code> changes at the target while the target has no
* pending PDUs to convey this information to the initiator, it MUST
* generate a NOP-IN to carry the new <code>MaxCmdSN</code>.
*
* @return Maximum Command Sequence Number.
*/
public final int getMaximumCommandSequenceNumber() {
return maximumCommandSequenceNumber;
}
/**
* The Status Sequence Number (StatSN) is a Sequence Number that the target
* iSCSI layer generates per connection and that in turn, enables the
* initiator to acknowledge status reception. <code>StatSN</code> is
* incremented by <code>1</code> for every response/status sent on a
* connection except for responses sent as a result of a retry or SNACK. In
* the case of responses sent due to a retransmission request, the <code>StatSN</code> MUST be the same as
* the first time the PDU was sent
* unless the connection has since been restarted.
*
* @return Status Sequence Number.
*/
public final int getStatusSequenceNumber() {
return statusSequenceNumber;
}
/**
* Sets the Expected Command Sequence Number of this <code>TargetMessageParser</code> object to the given
* value.
*
* @param newExpectedCommandSequenceNumber
* The new Expected Command Sequence Number.
*/
public final void setExpectedCommandSequenceNumber(final int newExpectedCommandSequenceNumber) {
expectedCommandSequenceNumber = newExpectedCommandSequenceNumber;
}
/**
* Sets the Maximum Command Sequence Number of this <code>TargetMessageParser</code> object to the given
* value.
*
* @param newMaximumCommandSequenceNumber
* The new Maximum Command Sequence Number.
*/
public final void setMaximumCommandSequenceNumber(final int newMaximumCommandSequenceNumber) {
maximumCommandSequenceNumber = newMaximumCommandSequenceNumber;
}
/**
* Sets the Status Sequence Number of this <code>TargetMessageParser</code> object to the given value.
*
* @param newStatusSequenceNumber
* The new Status Sequence Number.
*/
public final void setStatusSequenceNumber(final int newStatusSequenceNumber) {
statusSequenceNumber = newStatusSequenceNumber;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected void deserializeBytes1to3(final int line) throws InternetSCSIException {
Utils.isReserved(line);
}
/** {@inheritDoc} */
@Override
protected void deserializeBytes20to23(final int line) throws InternetSCSIException {
Utils.isReserved(line);
}
/** {@inheritDoc} */
@Override
protected final void deserializeBytes24to27(final int line) throws InternetSCSIException {
statusSequenceNumber = line;
}
/** {@inheritDoc} */
@Override
protected final void deserializeBytes28to31(final int line) throws InternetSCSIException {
expectedCommandSequenceNumber = line;
}
/** {@inheritDoc} */
@Override
protected final void deserializeBytes32to35(final int line) throws InternetSCSIException {
maximumCommandSequenceNumber = line;
}
/** {@inheritDoc} */
@Override
protected void deserializeBytes36to39(final int line) throws InternetSCSIException {
Utils.isReserved(line);
}
/** {@inheritDoc} */
@Override
protected void deserializeBytes40to43(final int line) throws InternetSCSIException {
Utils.isReserved(line);
}
/** {@inheritDoc} */
@Override
protected void deserializeBytes44to47(final int line) throws InternetSCSIException {
Utils.isReserved(line);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
protected int serializeBytes1to3() {
return Constants.RESERVED_INT;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes20to23() {
return Constants.RESERVED_INT;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes24to27() {
return statusSequenceNumber;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes28to31() {
return expectedCommandSequenceNumber;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes32to35() {
return maximumCommandSequenceNumber;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes36to39() {
return Constants.RESERVED_INT;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes40to43() {
return Constants.RESERVED_INT;
}
/** {@inheritDoc} */
@Override
protected int serializeBytes44to47() {
return Constants.RESERVED_INT;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
}