|
|
package org.openslx.virtualization.disk;
import java.io.RandomAccessFile;
import java.nio.charset.StandardCharsets;
import org.openslx.util.Util;
import org.openslx.virtualization.configuration.VirtualizationConfigurationVmwareFileFormat;
import org.openslx.virtualization.Version;
import org.openslx.virtualization.configuration.VirtualizationConfigurationException;
/**
* VMDK (sparse extent) disk image for virtual machines.
*
* @author Manuel Bentele
* @version 1.0
*/
public class DiskImageVmdk extends DiskImage
{
/**
* Big endian representation of the little endian magic bytes <code>KDMV</code>.
*/
private static final int VMDK_MAGIC = 0x4b444d56;
/**
* Size of a VMDK disk image data cluster in bytes.
*/
private static final int VMDK_SECTOR_SIZE = 512;
/**
* Default hardware version of a VMDK disk image.
*/
private static final int VMDK_DEFAULT_HW_VERSION = 10;
/**
* Stores disk configuration if VMDK disk image contains an embedded descriptor file.
*/
private final VirtualizationConfigurationVmwareFileFormat vmdkConfig;
/**
* Creates a new VMDK disk image from an existing VMDK image file.
*
* @param diskImage file to a VMDK disk storing the image content.
*
* @throws DiskImageException parsing of the VMDK's embedded descriptor file failed.
*/
DiskImageVmdk( RandomAccessFile diskImage ) throws DiskImageException
{
super( diskImage );
this.vmdkConfig = this.parseVmdkConfig();
}
/**
* Probe specified file with unknown format to be a VMDK disk image file.
*
* @param diskImage file with unknown format that should be probed.
* @return state whether file is a VMDK disk image or not.
*
* @throws DiskImageException cannot probe specified file with unknown format.
*/
public static boolean probe( RandomAccessFile diskImage ) throws DiskImageException
{
final boolean isVmdkImageFormat;
// goto the beginning of the disk image to read the magic bytes
final int diskImageMagic = DiskImageUtils.readInt( diskImage, 0 );
// check if disk image's magic bytes can be found
if ( diskImageMagic == DiskImageVmdk.VMDK_MAGIC ) {
isVmdkImageFormat = true;
} else {
isVmdkImageFormat = false;
}
return isVmdkImageFormat;
}
/**
* Returns the creation type from the VMDK's embedded descriptor file.
*
* @return creation type from the VMDK's embedded descriptor file.
*/
private String getCreationType()
{
final VirtualizationConfigurationVmwareFileFormat vmdkConfig = this.getVmdkConfig();
final String vmdkCreationType;
if ( vmdkConfig == null ) {
// VMDK disk image does not contain any descriptor file
// assume that the file is not stand alone
vmdkCreationType = null;
} else {
// VMDK disk image contains a descriptor file
// get creation type from the content of the descriptor file
vmdkCreationType = this.vmdkConfig.get( "createType" );
}
return vmdkCreationType;
}
/**
* Parse the configuration of the VMDK's embedded descriptor file.
*
* @return parsed configuration of the VMDK's embedded descriptor file.
*
* @throws DiskImageException parsing of the VMDK's embedded descriptor file failed.
*/
protected VirtualizationConfigurationVmwareFileFormat parseVmdkConfig() throws DiskImageException
{
final RandomAccessFile diskFile = this.getDiskImage();
final VirtualizationConfigurationVmwareFileFormat vmdkConfig;
// get offset and size of descriptor file embedded into the VMDK disk image
final long vmdkDescriptorSectorOffset = Long.reverseBytes( DiskImageUtils.readLong( diskFile, 28 ) );
final long vmdkDescriptorSectorSize = Long.reverseBytes( DiskImageUtils.readLong( diskFile, 36 ) );
if ( vmdkDescriptorSectorOffset > 0 ) {
// get content of descriptor file embedded into the VMDK disk image
final long vmdkDescriptorOffset = vmdkDescriptorSectorOffset * DiskImageVmdk.VMDK_SECTOR_SIZE;
final long vmdkDescriptorSizeMax = vmdkDescriptorSectorSize * DiskImageVmdk.VMDK_SECTOR_SIZE;
final String descriptorStr = new String ( DiskImageUtils.readBytesAsArray( diskFile, vmdkDescriptorOffset,
Long.valueOf( vmdkDescriptorSizeMax ).intValue() ), StandardCharsets.US_ASCII );
// get final length of the content within the sectors to be able to trim all 'zero' characters
final int vmdkDescriptorSize = descriptorStr.indexOf( 0 );
// if final length of the content is invalid, throw an exception
if ( vmdkDescriptorSize > vmdkDescriptorSizeMax || vmdkDescriptorSize < 0 ) {
final String errorMsg = "Embedded descriptor size in VMDK disk image is invalid!";
throw new DiskImageException( errorMsg );
}
// trim all 'zero' characters at the end of the descriptor content to avoid errors during parsing
final String configStr = descriptorStr.substring( 0, vmdkDescriptorSize );
// create configuration instance from content of the descriptor file
try {
vmdkConfig = new VirtualizationConfigurationVmwareFileFormat( configStr.getBytes(), vmdkDescriptorSize );
} catch ( VirtualizationConfigurationException e ) {
throw new DiskImageException( e.getLocalizedMessage() );
}
} else {
// there is no descriptor file embedded into the VMDK disk image
vmdkConfig = null;
}
return vmdkConfig;
}
/**
* Returns parsed configuration of the VMDK's embedded descriptor file.
*
* @return parsed configuration of the VMDK's embedded descriptor file.
*/
protected VirtualizationConfigurationVmwareFileFormat getVmdkConfig()
{
return this.vmdkConfig;
}
/**
* Returns the hardware version from the VMDK's embedded descriptor file.
*
* If the VMDK's embedded descriptor file does not contain any hardware version configuration
* entry, the default hardware version (see {@link #VMDK_DEFAULT_HW_VERSION}) is returned.
*
* @return hardware version from the VMDK's embedded descriptor file.
*
* @throws DiskImageException unable to obtain the VMDK's hardware version of the disk image
* format.
*/
public Version getHwVersion() throws DiskImageException
{
final VirtualizationConfigurationVmwareFileFormat vmdkConfig = this.getVmdkConfig();
final Version hwVersion;
if ( vmdkConfig != null ) {
// VMDK image contains a hardware version, so return parsed hardware version
// if hardware version cannot be parsed, return default hardware version
final String hwVersionStr = vmdkConfig.get( "ddb.virtualHWVersion" );
final int hwVersionMajor = Util.parseInt( hwVersionStr, DiskImageVmdk.VMDK_DEFAULT_HW_VERSION );
hwVersion = new Version( Integer.valueOf( hwVersionMajor ).shortValue() );
} else {
// VMDK image does not contain any hardware version, so return default hardware version
final int hwVersionMajor = DiskImageVmdk.VMDK_DEFAULT_HW_VERSION;
hwVersion = new Version( Integer.valueOf( hwVersionMajor ).shortValue() );
}
return hwVersion;
}
@Override
public boolean isStandalone() throws DiskImageException
{
final String vmdkCreationType = this.getCreationType();
final boolean vmdkStandalone;
if ( vmdkCreationType != null ) {
// creation type is defined, so check if VMDK disk image is a snapshot
if ( this.isSnapshot() ) {
// VMDK disk image is a snapshot and not stand alone
vmdkStandalone = false;
} else {
// VMDK disk image is not a snapshot
// determine stand alone disk image property
vmdkStandalone = vmdkCreationType.equalsIgnoreCase( "streamOptimized" ) ||
vmdkCreationType.equalsIgnoreCase( "monolithicSparse" );
}
} else {
// creation type is not defined
// assume that the file is not stand alone
vmdkStandalone = false;
}
return vmdkStandalone;
}
@Override
public boolean isCompressed() throws DiskImageException
{
final String vmdkCreationType = this.getCreationType();
final boolean vmdkCompressed;
if ( vmdkCreationType != null && vmdkCreationType.equalsIgnoreCase( "streamOptimized" ) ) {
// creation type is defined, and VMDK disk image is compressed
vmdkCompressed = true;
} else {
// creation type for compression is not defined
// assume that the file is not compressed
vmdkCompressed = false;
}
return vmdkCompressed;
}
@Override
public boolean isSnapshot() throws DiskImageException
{
final VirtualizationConfigurationVmwareFileFormat vmdkConfig = this.getVmdkConfig();
final boolean vmdkSnapshot;
if ( vmdkConfig == null ) {
// VMDK disk image does not contain any descriptor file
// assume that the file is not a snapshot
vmdkSnapshot = false;
} else {
// get parent CID to determine snapshot disk image property
final String parentCid = vmdkConfig.get( "parentCID" );
if ( parentCid != null && !parentCid.equalsIgnoreCase( "ffffffff" ) ) {
// link to parent content identifier is defined, so VMDK disk image is a snapshot
vmdkSnapshot = true;
} else {
// link to parent content identifier is not defined, so VMDK disk image is not a snapshot
vmdkSnapshot = false;
}
}
return vmdkSnapshot;
}
@Override
public Version getVersion() throws DiskImageException
{
final RandomAccessFile diskFile = this.getDiskImage();
final int vmdkVersion = Integer.reverseBytes( DiskImageUtils.readInt( diskFile, 4 ) );
return new Version( Integer.valueOf( vmdkVersion ).shortValue() );
}
@Override
public String getDescription() throws DiskImageException
{
return null;
}
@Override
public ImageFormat getFormat()
{
return ImageFormat.VMDK;
}
}
|
