/// <summary>
/// Validates the reparse point tag and GUID given.
/// </summary>
/// <param name="reparseTag">Reparse point tag.</param>
/// <param name="reparseGuid">Reparse point GUID.</param>
/// <exception cref="ArgumentException">
/// <paramref name="reparseTag"/> is a Microsoft tag, but the <paramref name="reparseGuid"/> is not <see langword="null"/>.
/// <para>-or-</para>
/// <paramref name="reparseTag"/> is a non-Microsoft tag, but the <paramref name="reparseGuid"/> is <see langword="null"/>.
/// </exception>
private static void ValidateTagAndGuid(int reparseTag, Guid?reparseGuid)
{
bool isMicrosoftTag = ReparsePointHelper.IsMicrosoftTag(reparseTag);
if (isMicrosoftTag && reparseGuid.HasValue)
{
throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "0x{0:X8} is a Microsoft tag, but the reparse GUID is specified.", reparseTag), nameof(reparseGuid));
}
if (!isMicrosoftTag && !reparseGuid.HasValue)
{
throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "0x{0:X8} is a non-Microsoft tag, but the reparse GUID is not specified.", reparseTag), nameof(reparseGuid));
}
}
/// <summary>
/// Gets the target for the symbolic link given.
/// </summary>
/// <param name="linkPath">Path to the symbolic link to get target for.</param>
/// <returns>Path to the link target.</returns>
/// <exception cref="ArgumentNullException"><paramref name="linkPath"/> is <see langword="null"/> or empty.</exception>
/// <exception cref="InvalidOperationException">Target information could not be retrieved from the symbolic link.</exception>
public static string GetLinkTarget(string linkPath)
{
SymbolicLinkReparsePointData reparseData = ReparsePointHelper.GetReparsePointData <SymbolicLinkReparsePointData>(linkPath, SymlinkHelper.SymbolicLinkTag, null);
return(Encoding.Unicode.GetString(reparseData.PathBuffer, reparseData.PrintNameOffset, reparseData.PrintNameLength));
}
/// <summary>
/// Sets the reparse point data for the <paramref name="path"/> given.
/// </summary>
/// <param name="path">File or directory to set the reparse point data for.</param>
/// <param name="data">
/// Reparse point data to be set.
/// It should be a value type, or an <see cref="IEnumerable"/>, and it should not contain
/// reparse point data header information, because this function handles it separately.
/// </param>
/// <param name="reparseTag">Reparse point tag.</param>
/// <param name="reparseGuid">Reparse point <see cref="Guid"/>. Must be specified, if the <paramref name="reparseTag"/> is a non-Microsoft tag.</param>
/// <exception cref="ArgumentNullException"><paramref name="path"/> is <see langword="null"/> or empty.</exception>
/// <exception cref="ArgumentException">
/// <paramref name="data"/> is not a collection or a value type.
/// <para>-or-</para>
/// <paramref name="reparseTag"/> is a Microsoft tag, but the <paramref name="reparseGuid"/> is not <see langword="null"/>.
/// <para>-or-</para>
/// <paramref name="reparseTag"/> is a non-Microsoft tag, but the <paramref name="reparseGuid"/> is <see langword="null"/>.
/// </exception>
/// <exception cref="InvalidOperationException">
/// Reparse point <paramref name="data"/> cannot be set for the <paramref name="path"/>.
/// </exception>
/// <exception cref="IOException">
/// <paramref name="path"/> cannot be accessed.
/// </exception>
/// <remarks>
/// This method will <i>NOT</i> update file attributes.<br/>
/// For example, the <see cref="FileAttributes.ReparsePoint"/> will not be set.
/// </remarks>
public static void SetReparsePointData(string path, object data, int reparseTag, Guid?reparseGuid)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
ReparsePointHelper.ValidateTagAndGuid(reparseTag, reparseGuid);
bool isMicrosoftTag = ReparsePointHelper.IsMicrosoftTag(reparseTag);
string normalizedPath = LongPathCommon.NormalizePath(path);
if (!LongPathCommon.Exists(normalizedPath))
{
throw new IOException(string.Format(CultureInfo.InvariantCulture, "{0} cannot be found.", path));
}
using (SafeFileHandle handle = NativeMethods.CreateFile(
normalizedPath,
AccessRights.GenericWrite,
FileShare.None,
IntPtr.Zero,
FileMode.Open,
EFileAttributes.OpenReparsePoint | EFileAttributes.BackupSemantics,
IntPtr.Zero))
{
if (handle.IsInvalid)
{
Exception nativeException = Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
throw new IOException(string.Format(CultureInfo.InvariantCulture, "Unable to open: {0}", path), nativeException);
}
int dataSize = MarshalingHelper.GetObjectSize(data);
object header = isMicrosoftTag
? (object)new ReparseDataBufferHeader {
ReparseDataLength = unchecked ((ushort)dataSize), ReparseTag = reparseTag
}
: new ReparseGuidDataBufferHeader {
ReparseDataLength = unchecked ((ushort)dataSize), ReparseTag = reparseTag, ReparseGuid = reparseGuid.Value
};
int headerSize = Marshal.SizeOf(header);
int tagDataLength = headerSize + dataSize;
using (ResizableBuffer buffer = new ResizableBuffer(Math.Max(ReparsePointHelper.BufferSize, tagDataLength)))
{
MarshalingHelper.MarshalObjectToPointer(new[] { header, data }, buffer.DangerousGetPointer());
// Set the reparse point data.
int bytesReturned;
bool success = NativeMethods.DeviceIoControl(
handle,
ReparsePointHelper.SetReparsePointControlCode,
buffer.DangerousGetPointer(),
tagDataLength,
IntPtr.Zero,
0,
out bytesReturned,
IntPtr.Zero);
if (!success)
{
Exception nativeException = Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Unable to set the reparse point data: {0}", path), nativeException);
}
}
}
}
/// <summary>
/// Gets the reparse point data from the <paramref name="path"/> given.
/// </summary>
/// <typeparam name="T">
/// Reparse point buffer data type.
/// It should not contain reparse point data header information, because this function handles it separately.
/// </typeparam>
/// <param name="path">Path to the reparse point to get data from.</param>
/// <param name="reparseTag">Reparse point tag.</param>
/// <param name="reparseGuid">Reparse point <see cref="Guid"/>. Must be specified, if the <paramref name="reparseTag"/> is a non-Microsoft tag.</param>
/// <returns>Reparse point data found.</returns>
/// <exception cref="ArgumentNullException"><paramref name="path"/> is <see langword="null"/> or empty.</exception>
/// <exception cref="ArgumentException">
/// <paramref name="reparseTag"/> is a Microsoft tag, but the <paramref name="reparseGuid"/> is not <see langword="null"/>.
/// <para>-or-</para>
/// <paramref name="reparseTag"/> is a non-Microsoft tag, but the <paramref name="reparseGuid"/> is <see langword="null"/>.
/// </exception>
/// <exception cref="InvalidOperationException">
/// <paramref name="path"/> cannot be found.
/// <para>-or-</para>
/// <paramref name="path"/> is not a reparse point.
/// <para>-or-</para>
/// <paramref name="path"/> reparse point cannot be opened.
/// <para>-or-</para>
/// <paramref name="path"/> reparse point data cannot be retrieved.
/// <para>-or-</para>
/// <paramref name="path"/> reparse point tag or GUID is invalid.
/// </exception>
/// <remarks>
/// See <c>http://msdn.microsoft.com/en-us/library/windows/desktop/aa365511(v=vs.85).aspx</c> for more details about reparse point tags.
/// </remarks>
public static T GetReparsePointData <T>(string path, int reparseTag, Guid?reparseGuid)
where T : struct
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(nameof(path));
}
ReparsePointHelper.ValidateTagAndGuid(reparseTag, reparseGuid);
bool isMicrosoftTag = ReparsePointHelper.IsMicrosoftTag(reparseTag);
string normalizedPath = LongPathCommon.NormalizePath(path);
bool isDirectory;
if (!LongPathCommon.Exists(normalizedPath, out isDirectory))
{
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Path does not exist: {0}", path));
}
// Check, whether the path given is a reparse point.
FileAttributes attributes = isDirectory ? new LongPathDirectoryInfo(normalizedPath).Attributes : LongPathFile.GetAttributes(normalizedPath);
if (!attributes.HasFlag(FileAttributes.ReparsePoint))
{
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Path given is not a reparse point: {0}", path));
}
using (SafeFileHandle handle = NativeMethods.CreateFile(
normalizedPath,
AccessRights.GenericRead,
FileShare.Read,
IntPtr.Zero,
FileMode.Open,
EFileAttributes.OpenReparsePoint | EFileAttributes.BackupSemantics,
IntPtr.Zero))
{
if (handle.IsInvalid)
{
Exception nativeException = Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Unable to open reparse point: {0}", path), nativeException);
}
// Make sure that the buffer will be large enough to hold reparse point data.
int initialBufferSize = Math.Max(ReparsePointHelper.BufferSize, Marshal.SizeOf(typeof(ReparseGuidDataBufferHeader)) + Marshal.SizeOf(typeof(T)));
using (ResizableBuffer buffer = new ResizableBuffer(initialBufferSize))
{
// Query the reparse point data.
int bytesReturned;
bool success = NativeMethods.DeviceIoControl(
handle,
ReparsePointHelper.GetReparsePointControlCode,
IntPtr.Zero,
0,
buffer.DangerousGetPointer(),
buffer.ByteLength,
out bytesReturned,
IntPtr.Zero);
int headerSize = isMicrosoftTag ? Marshal.SizeOf(typeof(ReparseDataBufferHeader)) : Marshal.SizeOf(typeof(ReparseGuidDataBufferHeader));
if (!success)
{
int hr = Marshal.GetHRForLastWin32Error();
if (hr != NativeMethods.ErrorMoreData)
{
Exception nativeException = Marshal.GetExceptionForHR(hr);
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Unable to get the reparse point data: {0}", path), nativeException);
}
// Read the ReparseDataLength value, and resize buffer to fit the data.
int dataSize = headerSize + Marshal.ReadInt16(buffer.DangerousGetPointer(), 4 /* sizeof(uint) */);
buffer.Resize(dataSize);
success = NativeMethods.DeviceIoControl(
handle,
ReparsePointHelper.GetReparsePointControlCode,
IntPtr.Zero,
0,
buffer.DangerousGetPointer(),
buffer.ByteLength,
out bytesReturned,
IntPtr.Zero);
if (!success)
{
Exception nativeException = Marshal.GetExceptionForHR(hr);
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Unable to get the reparse point data: {0}", path), nativeException);
}
}
// Make sure that the reparse tag is correct.
uint tag = unchecked ((uint)Marshal.ReadInt32(buffer.DangerousGetPointer()));
if (tag != unchecked ((uint)reparseTag))
{
throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, "Reparse point tag is invalid. Path has 0x{0:X8}, but 0x{1:X8} is specified.", tag, reparseTag));
}
// Make sure that the reparse point GUID is correct, if needed.
if (!isMicrosoftTag)
{
ReparseGuidDataBufferHeader header = (ReparseGuidDataBufferHeader)Marshal.PtrToStructure(buffer.DangerousGetPointer(), typeof(ReparseGuidDataBufferHeader));
if (header.ReparseGuid != reparseGuid)
{
throw new InvalidOperationException(string.Format(
CultureInfo.InvariantCulture,
"Reparse point GUID is invalid. Path has {0}, but {1} is specified.",
header.ReparseGuid.ToString("N"),
reparseGuid.Value.ToString("N")));
}
}
return((T)Marshal.PtrToStructure(buffer.DangerousGetPointer() + headerSize, typeof(T)));
}
}
}