public unsafe VdiHardDisk(HardDisk 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 static HardDisk Create(HardDisk hdd)
{
byte[] headBytes = hdd.ReadBytes(hdd.Length - 512, 512);
VhdHeader head = Program.ToStructFromBigEndian <VhdHeader>(headBytes);
if (head.CookieStr != "conectix")
{
throw new Exception("missing magic string");
}
if (head.FileFormatVersion != 0x00010000)
{
throw new Exception("upsupported version");
}
//TODO: validate checksum
if (head.DiskType == DiskType.Fixed)
{
return(new FixedVhd(hdd, in head));
}
else if (head.DiskType == DiskType.Dynamic)
{
return(new DynamicVhd(hdd, in head));
}
else
{
throw new Exception("Only fixed size VHDs are supported.");
}
}
unsafe public VdiHardDisk(HardDisk 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 override void ReadBytes(Span <byte> dest, long offset)
{
CheckOffsets(offset, dest.Length);
mHdd.ReadBytes(dest, mOffset + offset);
}
protected override void ReadBytesCore(Span <byte> dest, long offset)
{
mHdd.ReadBytes(dest, offset);
}
static VhdHeader GetHeader(HardDisk hdd)
{
return Program.ToStructByteSwap<VhdHeader>(hdd.ReadBytes(hdd.Length - 512, 512));
}
public DynamicVhd(HardDisk hdd)
: base(hdd)
{
VhdHeader head = GetHeader(hdd);
int dySize = Program.SizeOf<DynamicHeader>();
DynamicHeader dyhead = Program.ToStructByteSwap<DynamicHeader>(hdd.ReadBytes(head.DataOffset, dySize));
if (dyhead.CookieStr != "cxsparse")
throw new Exception("missing magic string");
if (dyhead.HeaderVersion != 0x00010000)
throw new NotSupportedException("wrong version");
if (dyhead.ParentUniqueID != Guid.Empty)
throw new NotSupportedException("Differencing disks not supported.");
mSize = head.CurrentSize;
mBlockSize = dyhead.BlockSize;
int sectorBitmapSize = (mBlockSize / SECTOR_SIZE) / 8;
int numberOfBlocks = (int)(mSize / mBlockSize);
if (numberOfBlocks > dyhead.MaxTableEntries)
throw new Exception();
mBlockOffsets = new long[numberOfBlocks];
var bat = hdd.ReadBytes(dyhead.TableOffset, numberOfBlocks * 4);
for (int i = 0; i < numberOfBlocks; i++)
{
Program.ByteSwap(typeof(int), bat, i * 4);
long batEntry = Program.ToStruct<int>(bat, i * 4);
if (batEntry != -1)
{
batEntry *= SECTOR_SIZE;
//skip the sector bitmap, since we don't support differencing disks
batEntry += sectorBitmapSize;
}
mBlockOffsets[i] = batEntry;
}
}
