public static DiskImage Create(DiskImage hdd, long offset, long size)
{
while (hdd is OffsetDiskImage)
{
var off = (OffsetDiskImage)hdd;
offset += off.mOffset;
hdd = off.mHdd;
}
return(new OffsetDiskImage(hdd, offset, size));
}
protected OffsetTableDiskImage(DiskImage hdd)
{
if (hdd == null)
{
throw new ArgumentNullException(nameof(hdd));
}
mHdd = hdd;
mReadBlock = readBlock;
mGetBlockKey = getBlockKey;
}
protected void Init(DiskImage hdd, long offset, long size)
{
if (offset < 0)
{
throw new ArgumentOutOfRangeException();
}
if (offset + size > hdd.Length)
{
throw new ArgumentOutOfRangeException();
}
mHdd = hdd;
mOffset = offset;
mSize = size;
}
unsafe public VdiDiskImage(DiskImage hdd)
: base(hdd)
{
var headBytes = hdd.ReadBytes(0, sizeof(VdiHeader));
VdiHeader head = Program.ToStruct <VdiHeader>(headBytes);
if (head.ImageSig != VdiMagic)
{
throw new Exception("Wrong magic.");
}
if (head.Version != VdiVersion)
{
throw new Exception("Wrong version.");
}
if (head.SizeOfHeader != VdiHeadSize)
{
throw new Exception("Wrong size.");
}
if (head.ImageType != ImageType.Dynamic)
{
throw new NotImplementedException("Only dynamic is supported.");
}
var dataOffset = head.OffsetData;
mBlockOffsets = new long[head.BlocksInHdd];
mBlockSize = (int)head.BlockSize;
for (long i = 0; i < head.BlocksInHdd; i++)
{
uint blockLoc;
hdd.Get <uint>(head.OffsetBlocks + i * 4, out blockLoc);
if (blockLoc == ~0u)
{
mBlockOffsets[i] = -1;
}
else
{
mBlockOffsets[i] = dataOffset + blockLoc * mBlockSize;
}
}
}
public VhdxDiskImage(DiskImage hdd)
: base(hdd)
{
VHDX_REGION_TABLE_ENTRY batRegion, metadataRegion;
GetRegions(out batRegion, out metadataRegion);
VHDX_FILE_PARAMETERS fileParams;
uint logicalSectorSize;
ReadMetadata(metadataRegion, out fileParams, out mVirtualDiskSize, out logicalSectorSize);
//TODO: confirm that we should use the logical, not the physica sector size.
if (logicalSectorSize != Program.SECTOR_SIZE)
{
//TODO: support other sizes.
throw new Exception("Unsupported sector size.");
}
if (fileParams.HasParent)
{
throw new NotImplementedException("Differencing disk are not supported.");
}
//check all these calculations to make sure our assumptions about data sizes are correct
checked
{
mBlockSize = (int)fileParams.BlockSize;
int chunkRatio = (int)((1L << 23) * logicalSectorSize / mBlockSize);
int dataBlockCount = (int)Math.Ceiling((decimal)mVirtualDiskSize / mBlockSize);
int sectorBitmapCount = (int)Math.Ceiling((decimal)dataBlockCount / chunkRatio);
int totalBatEntries = dataBlockCount + (int)Math.Floor((dataBlockCount - 1) / (decimal)chunkRatio);
if (batRegion.Length < Program.SizeOf <VHDX_BAT_ENTRY>() * totalBatEntries)
{
throw new Exception("Bat region is not big enough to contain all the bat entries!");
}
var batBytes = mHdd.ReadBytes((long)batRegion.FileOffset, (int)batRegion.Length);
mBlockOffsets = new long[dataBlockCount];
int fileOffsetsNdx = 0;
for (int i = 0; i < totalBatEntries; i++)
{
var isSectorBitmap = i % (chunkRatio + 1) == chunkRatio;
var entry = Program.ToStruct <VHDX_BAT_ENTRY>(batBytes, i * Program.SizeOf <VHDX_BAT_ENTRY>());
if (isSectorBitmap)
{
if (entry.SectorBitmapState != SectorBitmapState.NotPresent)
{
throw new Exception("Present bat entry!");
}
}
else
{
long offset;
switch (entry.PayloadState)
{
case PayloadBlockState.NotPresent:
case PayloadBlockState.Undefined:
case PayloadBlockState.BlockZero:
case PayloadBlockState.Unmapped:
offset = 0;
break;
case PayloadBlockState.FullyPresent:
offset = entry.FileOffsetMB << 20;
break;
case PayloadBlockState.PartiallyPresent:
throw new NotSupportedException("Partially present blocks are not supported.");
default:
throw new Exception($"Unknown BAT entry state: {entry.PayloadState}");
}
if (offset == 0)
{
offset = -1;
}
mBlockOffsets[fileOffsetsNdx++] = offset;
}
}
}
}
private OffsetDiskImage(DiskImage hdd, long offset, long size)
{
Init(hdd, offset, size);
}
public FixedVhd(DiskImage hdd, in VhdHeader head)