org.jscsi.parser.scsi

Class SCSICommandParser

java.lang.Object

org.jscsi.parser.AbstractMessageParser

org.jscsi.parser.InitiatorMessageParser

org.jscsi.parser.scsi.SCSICommandParser

public class SCSICommandParser
extends InitiatorMessageParser

SCSICommandParser

This class parses a SCSI Command message defined in the iSCSI Standard (RFC3720).

CmdSN - Command Sequence Number

Enables ordered delivery across multiple connections in a single session.

ExpStatSN

Command responses up to ExpStatSN - 1 (mod 2**32) have been received (acknowledges status) on the connection.

Data Segment - Command Data

Some SCSI commands require additional parameter data to accompany the SCSI command. This data may be placed beyond the boundary of the iSCSI header in a data segment. Alternatively, user data (e.g., from a WRITE operation) can be placed in the data segment (both cases are referred to as immediate data). These data are governed by the rules for solicited vs. unsolicited data outlined in Section 3.2.4.2 Data Transfer Overview.

Author:

Volker Wildi

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SCSICommandParser.TaskAttributes This enumeration defines all valid types of additional header segments, which are defined by the iSCSI standard (RFC3720).

Field Summary

Fields inherited from class org.jscsi.parser.InitiatorMessageParser

commandSequenceNumber, expectedStatusSequenceNumber

Fields inherited from class org.jscsi.parser.AbstractMessageParser

logicalUnitNumber, protocolDataUnit

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canContainAdditionalHeaderSegments() If this method returns true, it indicates that this derived AbstractMessageParser can contain one or more Additional Header Segments.
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.
protected void	deserializeBytes32to35(int line) Parse the bytes 32 till 35 in the Basic Header Segment.
protected void	deserializeBytes36to39(int line) Parse the bytes 36 till 39 in the Basic Header Segment.
protected void	deserializeBytes40to43(int line) Parse the bytes 40 till 43 in the Basic Header Segment.
protected void	deserializeBytes44to47(int line) Parse the bytes 44 till 47 in the Basic Header Segment.
ByteBuffer	getCDB() There are 16 bytes in the CDB field to accommodate the commonly used CDBs.
DataSegmentFactory.DataSegmentFormat	getDataSegmentFormat() If this method returns true, hen it indicates that the data segment data is interpreted as binary data.
int	getExpectedDataTransferLength() For unidirectional operations, the Expected Data Transfer Length field contains the number of bytes of data involved in this SCSI operation.
SCSICommandParser.TaskAttributes	getTaskAttributes()
boolean	isReadExpectedFlag() The command expects input data (read).
boolean	isWriteExpectedFlag() The command expects output data (write).
protected int	serializeBytes1to3() Serializes the bytes 1 till 3 in the Basic Header Segment.
protected int	serializeBytes20to23() Serializes the bytes 20 till 23 in the Basic Header Segment.
protected int	serializeBytes32to35() Serializes the bytes 32 till 35 in the Basic Header Segment.
protected int	serializeBytes36to39() Serializes the bytes 36 till 39 in the Basic Header Segment.
protected int	serializeBytes40to43() Serializes the bytes 40 till 43 in the Basic Header Segment.
protected int	serializeBytes44to47() Serializes the bytes 44 till 47 in the Basic Header Segment.
void	setCommandDescriptorBlock(ByteBuffer newCDB) Sets the new Command Descriptor Block.
void	setExpectedDataTransferLength(int newExpectedDataTransferLength)
void	setReadExpectedFlag(boolean newReadExpectedFlag)
void	setTaskAttributes(SCSICommandParser.TaskAttributes newTaskAttributes)
void	setWriteExpectedFlag(boolean newWriteExpectedFlag)
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.InitiatorMessageParser

deserializeBytes24to27, deserializeBytes28to31, getCommandSequenceNumber, getExpectedStatusSequenceNumber, getShortInfo, incrementSequenceNumber, serializeBytes24to27, serializeBytes28to31, setCommandSequenceNumber, setExpectedStatusSequenceNumber

Methods inherited from class org.jscsi.parser.AbstractMessageParser

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

SCSICommandParser

public SCSICommandParser(ProtocolDataUnit initProtocolDataUnit)

Default constructor, creates a new, empty SCSICommandParser object.

Parameters:

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

Method Detail

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 InitiatorMessageParser

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

canContainAdditionalHeaderSegments

public final boolean canContainAdditionalHeaderSegments()

If this method returns true, it indicates that this derived AbstractMessageParser can contain one or more Additional Header Segments.

Overrides:

canContainAdditionalHeaderSegments in class AbstractMessageParser

Returns:

Returns true, if this AbstractMessageParser object can contain one or more AHSs.

See Also:

AdditionalHeaderSegment

clear

public final void clear()

This method sets all settings to their initial values.

Overrides:

clear in class InitiatorMessageParser

getCDB

public final ByteBuffer getCDB()

There are 16 bytes in the CDB field to accommodate the commonly used CDBs. Whenever the CDB is larger than 16 bytes, an Extended CDB AHS MUST be used to contain the CDB spillover.

Returns:

A ByteBuffer with the content of the Command Descriptor Blocks contained in this SCSICommandParser object.

getExpectedDataTransferLength

public final int getExpectedDataTransferLength()

For unidirectional operations, the Expected Data Transfer Length field contains the number of bytes of data involved in this SCSI operation. For a unidirectional write operation (W flag set to 1 and R flag set to 0), the initiator uses this field to specify the number of bytes of data it expects to transfer for this operation. For a unidirectional read operation (W flag set to 0 and R flag set to 1), the initiator uses this field to specify the number of bytes of data it expects the target to transfer to the initiator. It corresponds to the SAM2 byte count.

For bidirectional operations (both R and W flags are set to 1 ), this field contains the number of data bytes involved in the write transfer. For bidirectional operations, an additional header segment MUST be present in the header sequence that indicates the Bidirectional Read Expected Data Transfer Length. The Expected Data Transfer Length field and the Bidirectional Read Expected Data Transfer Length field correspond to the SAM2 byte count.

If the Expected Data Transfer Length for a write and the length of the immediate data part that follows the command (if any) are the same, then no more data PDUs are expected to follow. In this case, the F bit MUST be set to 1.

If the Expected Data Transfer Length is higher than the FirstBurstLength (the negotiated maximum amount of unsolicited data the target will accept), the initiator MUST send the maximum amount of unsolicited data OR ONLY the immediate data, if any.

Upon completion of a data transfer, the target informs the initiator (through residual counts) of how many bytes were actually processed (sent and/or received) by the target.

Returns:

The Expected Data Transfer Length of this SCSICommandParser object.

isReadExpectedFlag

public final boolean isReadExpectedFlag()

The command expects input data (read).

Returns:

true,if a read command is expected. Else false.

setReadExpectedFlag

public final void setReadExpectedFlag(boolean newReadExpectedFlag)

Parameters:

newReadExpectedFlag - The readExpectedFlag to set.

getTaskAttributes

public final SCSICommandParser.TaskAttributes getTaskAttributes()

Returns:

Returns the taskAttributes.

setTaskAttributes

public final void setTaskAttributes(SCSICommandParser.TaskAttributes newTaskAttributes)

Parameters:

newTaskAttributes - The taskAttributes to set.

isWriteExpectedFlag

public final boolean isWriteExpectedFlag()

The command expects output data (write).

Returns:

true,if a write command is expected. Else false.

setWriteExpectedFlag

public final void setWriteExpectedFlag(boolean newWriteExpectedFlag)

Parameters:

newWriteExpectedFlag - The writeExpectedFlag to set.

setCommandDescriptorBlock

public final void setCommandDescriptorBlock(ByteBuffer newCDB)

Sets the new Command Descriptor Block.

Parameters:

newCDB - The new Command Descriptor Block.

setExpectedDataTransferLength

public final void setExpectedDataTransferLength(int newExpectedDataTransferLength)

Parameters:

newExpectedDataTransferLength - The expectedDataTransferLength to set.

deserializeBytes1to3

protected final void deserializeBytes1to3(int line)
                                   throws InternetSCSIException

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

Overrides:

deserializeBytes1to3 in class InitiatorMessageParser

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 InitiatorMessageParser

Parameters:

line - The actual line

Throws:

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

deserializeBytes32to35

protected final void deserializeBytes32to35(int line)
                                     throws InternetSCSIException

Parse the bytes 32 till 35 in the Basic Header Segment.

Overrides:

deserializeBytes32to35 in class InitiatorMessageParser

Parameters:

line - The actual line

Throws:

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

deserializeBytes36to39

protected final void deserializeBytes36to39(int line)
                                     throws InternetSCSIException

Parse the bytes 36 till 39 in the Basic Header Segment.

Overrides:

deserializeBytes36to39 in class InitiatorMessageParser

Parameters:

line - The actual line

Throws:

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

deserializeBytes40to43

protected final void deserializeBytes40to43(int line)
                                     throws InternetSCSIException

Parse the bytes 40 till 43 in the Basic Header Segment.

Overrides:

deserializeBytes40to43 in class InitiatorMessageParser

Parameters:

line - The actual line

Throws:

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

deserializeBytes44to47

protected final void deserializeBytes44to47(int line)
                                     throws InternetSCSIException

Parse the bytes 44 till 47 in the Basic Header Segment.

Overrides:

deserializeBytes44to47 in class InitiatorMessageParser

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.

serializeBytes1to3

protected final int serializeBytes1to3()

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

Overrides:

serializeBytes1to3 in class InitiatorMessageParser

Returns:

The serialized byte representation.

serializeBytes20to23

protected final int serializeBytes20to23()

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

Overrides:

serializeBytes20to23 in class InitiatorMessageParser

Returns:

The serialized byte representation.

serializeBytes32to35

protected final int serializeBytes32to35()

Serializes the bytes 32 till 35 in the Basic Header Segment.

Overrides:

serializeBytes32to35 in class InitiatorMessageParser

Returns:

The serialized byte representation.

serializeBytes36to39

protected final int serializeBytes36to39()

Serializes the bytes 36 till 39 in the Basic Header Segment.

Overrides:

serializeBytes36to39 in class InitiatorMessageParser

Returns:

The serialized byte representation.

serializeBytes40to43

protected final int serializeBytes40to43()

Serializes the bytes 40 till 43 in the Basic Header Segment.

Overrides:

serializeBytes40to43 in class InitiatorMessageParser

Returns:

The serialized byte representation.

serializeBytes44to47

protected final int serializeBytes44to47()

Serializes the bytes 44 till 47 in the Basic Header Segment.

Overrides:

serializeBytes44to47 in class InitiatorMessageParser

Returns:

The serialized byte representation.