org.jscsi.parser.nop

Class NOPInParser

java.lang.Object

org.jscsi.parser.AbstractMessageParser

org.jscsi.parser.TargetMessageParser

org.jscsi.parser.nop.NOPInParser

public final class NOPInParser
extends TargetMessageParser

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

Field Summary

Fields inherited from class org.jscsi.parser.TargetMessageParser

expectedCommandSequenceNumber, maximumCommandSequenceNumber, statusSequenceNumber

Fields inherited from class org.jscsi.parser.AbstractMessageParser

logicalUnitNumber, protocolDataUnit

Constructor Summary

Constructors

Constructor and Description
NOPInParser(ProtocolDataUnit initProtocolDataUnit) Default constructor, creates a new, empty NOPInParser object.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	checkIntegrity() This method checks, if all parsed fields are valid.
void	clear() This method sets all settings to their initial values.
protected void	deserializeBytes1to3(int line) Parse the bytes 1 till 3 in the Basic Header Segment.
protected void	deserializeBytes20to23(int line) Parse the bytes 20 till 23 in the Basic Header Segment.
DataSegmentFactory.DataSegmentFormat	getDataSegmentFormat() If this method returns true, hen it indicates that the data segment data is interpreted as binary data.
int	getTargetTransferTag() If the target is responding to a NOP-Out, this is set to the reserved value 0xffffffff.
protected int	serializeBytes20to23() Serializes the bytes 20 till 23 in the Basic Header Segment.
void	setTargetTransferTag(int targetTransferTag) Sets the Target Transfer Tag of this object.
String	toString() This method concatenate all the fields of a derived parser to allow an easy generation of debug informations.

Methods inherited from class org.jscsi.parser.TargetMessageParser

deserializeBytes24to27, deserializeBytes28to31, deserializeBytes32to35, deserializeBytes36to39, deserializeBytes40to43, deserializeBytes44to47, getExpectedCommandSequenceNumber, getMaximumCommandSequenceNumber, getShortInfo, getStatusSequenceNumber, incrementSequenceNumber, serializeBytes1to3, serializeBytes24to27, serializeBytes28to31, serializeBytes32to35, serializeBytes36to39, serializeBytes40to43, serializeBytes44to47, setExpectedCommandSequenceNumber, setMaximumCommandSequenceNumber, setStatusSequenceNumber

Methods inherited from class org.jscsi.parser.AbstractMessageParser

canContainAdditionalHeaderSegments, canHaveDigests, deserializeBytes12to15, deserializeBytes8to11, getLogicalUnitNumber, serializeBytes12to15, serializeBytes8to11, setLogicalUnitNumber

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NOPInParser

public NOPInParser(ProtocolDataUnit initProtocolDataUnit)

Default constructor, creates a new, empty NOPInParser object.

Parameters:

initProtocolDataUnit - The reference ProtocolDataUnit instance, which contains this NOPInParser subclass object.

Method Detail

getTargetTransferTag

public final int getTargetTransferTag()

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.

Returns:

The target transfer tag of this object.

setTargetTransferTag

public final void setTargetTransferTag(int targetTransferTag)

Sets the Target Transfer Tag of this object.

Parameters:

targetTransferTag - the new Target Transfer Tag.

toString

public final String toString()

This method concatenate all the fields of a derived parser to allow an easy generation of debug informations.

Overrides:

toString in class TargetMessageParser

Returns:

The debug formatted string.

getDataSegmentFormat

public final DataSegmentFactory.DataSegmentFormat getDataSegmentFormat()

If this method returns true, hen it indicates that the data segment data is interpreted as binary data. Else the data segment data must be interpreted as Text Format.

Specified by:

getDataSegmentFormat in class AbstractMessageParser

Returns:

Returns a format defined by the DataSegmentFormat enumeration.

See Also:

DataSegmentFactory.DataSegmentFormat

clear

public final void clear()

This method sets all settings to their initial values.

Overrides:

clear in class TargetMessageParser

deserializeBytes1to3

protected final void deserializeBytes1to3(int line)
                                   throws InternetSCSIException

Parse the bytes 1 till 3 in the Basic Header Segment.

Overrides:

deserializeBytes1to3 in class TargetMessageParser

Parameters:

line - The actual line

Throws:

InternetSCSIException - If any violation of the iSCSI-Standard emerge.

deserializeBytes20to23

protected final void deserializeBytes20to23(int line)
                                     throws InternetSCSIException

Parse the bytes 20 till 23 in the Basic Header Segment.

Overrides:

deserializeBytes20to23 in class TargetMessageParser

Parameters:

line - The actual line

Throws:

InternetSCSIException - If any violation of the iSCSI-Standard emerge.

checkIntegrity

protected final void checkIntegrity()
                             throws InternetSCSIException

This method checks, if all parsed fields are valid. Because there are several fields, which are reserved for future versions, and these must be zero. Is this the case an exception will be thrown.

Specified by:

checkIntegrity in class AbstractMessageParser

Throws:

InternetSCSIException - If the integrity is violated.

serializeBytes20to23

protected final int serializeBytes20to23()

Serializes the bytes 20 till 23 in the Basic Header Segment.

Overrides:

serializeBytes20to23 in class TargetMessageParser

Returns:

The serialized byte representation.