/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="System.IO.InvalidDataException"></exception>
/// <exception cref="System.NotImplementedException"></exception>
/// <exception cref="System.UnauthorizedAccessException"></exception>
public VirtualHardDisk(string virtualHardDiskPath) : base(virtualHardDiskPath)
{
// We can't read the VHD footer using this.ReadSector() because it's out of the disk boundaries
m_file = new RawDiskImage(virtualHardDiskPath, BytesPerDiskSector);
byte[] buffer = m_file.ReadSector(m_file.Size / BytesPerDiskSector - 1);
m_vhdFooter = new VHDFooter(buffer);
if (!m_vhdFooter.IsValid)
{
// check to see if a header is present (dynamic VHD) and use it instead
buffer = m_file.ReadSector(0);
m_vhdFooter = new VHDFooter(buffer);
if (!m_vhdFooter.IsValid)
{
throw new InvalidDataException("Invalid VHD footer");
}
}
if (m_vhdFooter.DiskType == VirtualHardDiskType.Fixed)
{
}
else if (m_vhdFooter.DiskType == VirtualHardDiskType.Dynamic)
{
buffer = m_file.ReadSectors(1, 2);
m_dynamicHeader = new DynamicDiskHeader(buffer);
m_blockAllocationTable = BlockAllocationTable.ReadBlockAllocationTable(virtualHardDiskPath, m_dynamicHeader);
}
else
{
throw new NotImplementedException("Differencing VHD is not supported");
}
SetGeometry();
}
/// <param name="size">In bytes</param>
/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="System.UnauthorizedAccessException"></exception>
public static VirtualHardDisk Create(string path, long size)
{
VHDFooter footer = new VHDFooter();
footer.OriginalSize = (ulong)size;
footer.CurrentSize = (ulong)size;
footer.SetCurrentTimeStamp();
footer.SetDiskGeometry((ulong)size / BytesPerDiskSector);
RawDiskImage diskImage = RawDiskImage.Create(path, size + VHDFooter.Length, BytesPerDiskSector);
diskImage.WriteSectors(size / BytesPerDiskSector, footer.GetBytes());
return(new VirtualHardDisk(path));
}
/// <param name="diskSize">In bytes</param>
/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="System.UnauthorizedAccessException"></exception>
public static VirtualHardDisk CreateFixedDisk(string path, long diskSize)
{
if (diskSize % BytesPerDiskSector > 0)
{
throw new ArgumentException("diskSize must be a multiple of sector size");
}
VHDFooter footer = new VHDFooter();
footer.OriginalSize = (ulong)diskSize;
footer.CurrentSize = (ulong)diskSize;
footer.SetCurrentTimeStamp();
footer.SetDiskGeometry((ulong)diskSize / BytesPerDiskSector);
RawDiskImage diskImage = RawDiskImage.Create(path, diskSize + VHDFooter.Length, BytesPerDiskSector);
diskImage.WriteSectors(diskSize / BytesPerDiskSector, footer.GetBytes());
return(new VirtualHardDisk(path));
}
/// <param name="diskSize">In bytes</param>
/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="System.UnauthorizedAccessException"></exception>
public static VirtualHardDisk CreateDynamicDisk(string path, long diskSize)
{
const int BlockSizeInBytes = 4096 * BytesPerDiskSector;
if (diskSize % BlockSizeInBytes > 0)
{
// All blocks within a given image must be the same size
throw new ArgumentException("Dynamic VHD disk size must be a multiple of 2MiB");
}
VHDFooter footer = new VHDFooter();
footer.OriginalSize = (ulong)diskSize;
footer.CurrentSize = (ulong)diskSize;
footer.SetCurrentTimeStamp();
footer.SetDiskGeometry((ulong)diskSize / BytesPerDiskSector);
footer.DiskType = VirtualHardDiskType.Dynamic;
DynamicDiskHeader header = new DynamicDiskHeader();
header.TableOffset = VHDFooter.Length + DynamicDiskHeader.Length;
header.BlockSize = BlockSizeInBytes;
header.MaxTableEntries = (uint)Math.Ceiling((double)diskSize / BlockSizeInBytes);
BlockAllocationTable blockAllocationTable = new BlockAllocationTable(header.MaxTableEntries);
byte[] footerBytes = footer.GetBytes();
byte[] headerBytes = header.GetBytes();
byte[] blockAllocationTableBytes = blockAllocationTable.GetBytes();
int fileSize = VHDFooter.Length + DynamicDiskHeader.Length + blockAllocationTableBytes.Length + VHDFooter.Length;
RawDiskImage diskImage = RawDiskImage.Create(path, fileSize, BytesPerDiskSector);
diskImage.WriteSectors(0, footerBytes);
diskImage.WriteSectors(1, headerBytes);
diskImage.WriteSectors(3, blockAllocationTableBytes);
diskImage.WriteSectors(fileSize / BytesPerDiskSector - 1, footerBytes);
return(new VirtualHardDisk(path));
}
/// <param name="length">In bytes</param>
/// <exception cref="System.IO.IOException"></exception>
/// <exception cref="System.UnauthorizedAccessException"></exception>
public static VirtualHardDisk Create(string path, long length)
{
bool hasManageVolumePrivilege = SecurityUtils.ObtainManageVolumePrivilege();
FileStream stream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None);
try
{
stream.SetLength(length + 512); // VHD footer is 512 bytes
if (hasManageVolumePrivilege)
{
FileStreamUtils.SetValidLength(stream, length + 512);
}
}
catch (IOException)
{
stream.Close();
try
{
// Delete the incomplete file
File.Delete(path);
}
catch (IOException)
{
}
throw;
}
VHDFooter footer = new VHDFooter();
footer.OriginalSize = (ulong)length;
footer.CurrentSize = (ulong)length;
footer.SetCurrentTimeStamp();
footer.SetDiskGeometry((ulong)length / DiskImage.DEFAULT_BYTES_PER_SECTOR);
stream.Seek(length, SeekOrigin.Begin);
stream.Write(footer.GetBytes(), 0, VHDFooter.Length);
stream.Close();
return(new VirtualHardDisk(path));
}
