/// <summary>[AlphaFS] Creates an NTFS directory junction (similar to CMD command: "MKLINK /J").</summary>
internal static void CreateDirectoryJunction(SafeFileHandle safeHandle, string directoryPath)
{
var targetDirBytes = Encoding.Unicode.GetBytes(Path.NonInterpretedPathPrefix + Path.GetRegularPathCore(directoryPath, GetFullPathOptions.AddTrailingDirectorySeparator, false));
var header = new NativeMethods.ReparseDataBufferHeader
{
ReparseTag = ReparsePointTag.MountPoint,
ReparseDataLength = (ushort)(targetDirBytes.Length + 12)
};
var mountPoint = new NativeMethods.MountPointReparseBuffer
{
SubstituteNameOffset = 0,
SubstituteNameLength = (ushort)targetDirBytes.Length,
PrintNameOffset = (ushort)(targetDirBytes.Length + UnicodeEncoding.CharSize),
PrintNameLength = 0
};
var reparseDataBuffer = new NativeMethods.REPARSE_DATA_BUFFER
{
ReparseTag = header.ReparseTag,
ReparseDataLength = header.ReparseDataLength,
SubstituteNameOffset = mountPoint.SubstituteNameOffset,
SubstituteNameLength = mountPoint.SubstituteNameLength,
PrintNameOffset = mountPoint.PrintNameOffset,
PrintNameLength = mountPoint.PrintNameLength,
PathBuffer = new byte[NativeMethods.MAXIMUM_REPARSE_DATA_BUFFER_SIZE - 16] // 16368
};
targetDirBytes.CopyTo(reparseDataBuffer.PathBuffer, 0);
using (var safeBuffer = new SafeGlobalMemoryBufferHandle(Marshal.SizeOf(reparseDataBuffer)))
{
safeBuffer.StructureToPtr(reparseDataBuffer, false);
uint bytesReturned;
var succes = NativeMethods.DeviceIoControl2(safeHandle, NativeMethods.FSCTL_SET_REPARSE_POINT, safeBuffer, (uint)(targetDirBytes.Length + 20), IntPtr.Zero, 0, out bytesReturned, IntPtr.Zero);
var lastError = Marshal.GetLastWin32Error();
if (!succes)
{
NativeError.ThrowException(lastError, directoryPath);
}
}
}
internal static LinkTargetInfo GetLinkTargetInfoInternal(SafeFileHandle safeHandle)
{
// Start with a large buffer to prevent a 2nd call.
uint bytesReturned = NativeMethods.MaxPathUnicode;
using (SafeGlobalMemoryBufferHandle safeBuffer = new SafeGlobalMemoryBufferHandle((int)bytesReturned))
{
do
{
// Possible PInvoke signature bug: safeBuffer.Capacity and bytesReturned are always the same.
// Since a large buffer is used, we are not affected.
// DeviceIoControlMethod.Buffered = 0,
// DeviceIoControlFileDevice.FileSystem = 9
// FsctlGetReparsePoint = (DeviceIoControlFileDevice.FileSystem << 16) | (42 << 2) | DeviceIoControlMethod.Buffered | (0 << 14)
if (!NativeMethods.DeviceIoControl(safeHandle, ((9 << 16) | (42 << 2) | 0 | (0 << 14)), IntPtr.Zero, 0, safeBuffer, (uint)safeBuffer.Capacity, out bytesReturned, IntPtr.Zero))
{
int lastError = Marshal.GetLastWin32Error();
switch ((uint)lastError)
{
case Win32Errors.ERROR_MORE_DATA:
case Win32Errors.ERROR_INSUFFICIENT_BUFFER:
if (safeBuffer.Capacity < bytesReturned)
{
safeBuffer.Close();
break;
}
// Throws IOException.
NativeError.ThrowException(lastError, true);
break;
}
}
else
{
break;
}
} while (true);
// CA2001:AvoidCallingProblematicMethods
IntPtr buffer = IntPtr.Zero;
bool successRef = false;
safeBuffer.DangerousAddRef(ref successRef);
// MSDN: The DangerousGetHandle method poses a security risk because it can return a handle that is not valid.
if (successRef)
{
buffer = safeBuffer.DangerousGetHandle();
}
safeBuffer.DangerousRelease();
if (buffer == IntPtr.Zero)
{
NativeError.ThrowException(Resources.HandleDangerousRef);
}
// CA2001:AvoidCallingProblematicMethods
Type toMountPointReparseBuffer = typeof(NativeMethods.MountPointReparseBuffer);
Type toReparseDataBufferHeader = typeof(NativeMethods.ReparseDataBufferHeader);
Type toSymbolicLinkReparseBuffer = typeof(NativeMethods.SymbolicLinkReparseBuffer);
IntPtr marshalReparseBuffer = Marshal.OffsetOf(toReparseDataBufferHeader, "data");
NativeMethods.ReparseDataBufferHeader header = Utils.MarshalPtrToStructure <NativeMethods.ReparseDataBufferHeader>(0, buffer);
IntPtr dataPos;
byte[] dataBuffer;
switch (header.ReparseTag)
{
case ReparsePointTag.MountPoint:
NativeMethods.MountPointReparseBuffer mprb = Utils.MarshalPtrToStructure <NativeMethods.MountPointReparseBuffer>(0, new IntPtr(buffer.ToInt64() + marshalReparseBuffer.ToInt64()));
dataPos = new IntPtr(marshalReparseBuffer.ToInt64() + Marshal.OffsetOf(toMountPointReparseBuffer, "data").ToInt64());
dataBuffer = new byte[bytesReturned - dataPos.ToInt64()];
Marshal.Copy(new IntPtr(buffer.ToInt64() + dataPos.ToInt64()), dataBuffer, 0, dataBuffer.Length);
return(new LinkTargetInfo(
Encoding.Unicode.GetString(dataBuffer, mprb.SubstituteNameOffset, mprb.SubstituteNameLength),
Encoding.Unicode.GetString(dataBuffer, mprb.PrintNameOffset, mprb.PrintNameLength)));
case ReparsePointTag.SymLink:
NativeMethods.SymbolicLinkReparseBuffer slrb = Utils.MarshalPtrToStructure <NativeMethods.SymbolicLinkReparseBuffer>(0, new IntPtr(buffer.ToInt64() + marshalReparseBuffer.ToInt64()));
dataPos = new IntPtr(marshalReparseBuffer.ToInt64() + Marshal.OffsetOf(toSymbolicLinkReparseBuffer, "data").ToInt64());
dataBuffer = new byte[bytesReturned - dataPos.ToInt64()];
Marshal.Copy(new IntPtr(buffer.ToInt64() + dataPos.ToInt64()), dataBuffer, 0, dataBuffer.Length);
return(new SymbolicLinkTargetInfo(
Encoding.Unicode.GetString(dataBuffer, slrb.SubstituteNameOffset, slrb.SubstituteNameLength),
Encoding.Unicode.GetString(dataBuffer, slrb.PrintNameOffset, slrb.PrintNameLength), slrb.Flags));
default:
throw new UnrecognizedReparsePointException();
}
}
}
