private static unsafe SafeFileHandle CreateFileOpenHandle(string path, FileMode mode, FileAccess access, FileShare share, FileOptions options)
{
Interop.Kernel32.SECURITY_ATTRIBUTES secAttrs = GetSecAttrs(share);
int fAccess =
((access & FileAccess.Read) == FileAccess.Read ? Interop.Kernel32.GenericOperations.GENERIC_READ : 0) |
((access & FileAccess.Write) == FileAccess.Write ? Interop.Kernel32.GenericOperations.GENERIC_WRITE : 0);
// Our Inheritable bit was stolen from Windows, but should be set in
// the security attributes class. Don't leave this bit set.
share &= ~FileShare.Inheritable;
// Must use a valid Win32 constant here...
if (mode == FileMode.Append)
{
mode = FileMode.OpenOrCreate;
}
int flagsAndAttributes = (int)options;
// For mitigating local elevation of privilege attack through named pipes
// make sure we always call CreateFile with SECURITY_ANONYMOUS so that the
// named pipe server can't impersonate a high privileged client security context
// (note that this is the effective default on CreateFile2)
flagsAndAttributes |= (Interop.Kernel32.SecurityOptions.SECURITY_SQOS_PRESENT | Interop.Kernel32.SecurityOptions.SECURITY_ANONYMOUS);
using (DisableMediaInsertionPrompt.Create())
{
Debug.Assert(path != null);
return(ValidateFileHandle(
Interop.Kernel32.CreateFile(path, fAccess, share, &secAttrs, mode, flagsAndAttributes, IntPtr.Zero),
path,
(options & FileOptions.Asynchronous) != 0));
}
}
public static DisableMediaInsertionPrompt Create()
{
DisableMediaInsertionPrompt prompt = default;
prompt._disableSuccess = Interop.Kernel32.SetThreadErrorMode(Interop.Kernel32.SEM_FAILCRITICALERRORS, out prompt._oldMode);
return(prompt);
}
private static unsafe void ThrowExceptionEncryptDecryptFail(string fullPath)
{
int errorCode = Marshal.GetLastWin32Error();
if (errorCode == Interop.Errors.ERROR_ACCESS_DENIED)
{
// Check to see if the file system support the Encrypted File System (EFS)
string name = DriveInfoInternal.NormalizeDriveName(Path.GetPathRoot(fullPath));
using (DisableMediaInsertionPrompt.Create())
{
if (!Interop.Kernel32.GetVolumeInformation(name, null, 0, null, null, out int fileSystemFlags, null, 0))
{
errorCode = Marshal.GetLastWin32Error();
throw Win32Marshal.GetExceptionForWin32Error(errorCode, name);
}
if ((fileSystemFlags & Interop.Kernel32.FILE_SUPPORTS_ENCRYPTION) == 0)
{
throw new NotSupportedException(SR.PlatformNotSupported_FileEncryption);
}
}
}
throw Win32Marshal.GetExceptionForWin32Error(errorCode, fullPath);
}
internal static unsafe SafeFileHandle Open(string fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, long preallocationSize)
{
using (DisableMediaInsertionPrompt.Create())
{
SafeFileHandle fileHandle = new SafeFileHandle(
NtCreateFile(fullPath, mode, access, share, options, preallocationSize),
ownsHandle: true,
options);
fileHandle.InitThreadPoolBindingIfNeeded();
return(fileHandle);
}
}
internal static int FillAttributeInfo(string path, ref Interop.Kernel32.WIN32_FILE_ATTRIBUTE_DATA data, bool returnErrorOnNotFound)
{
int errorCode = Interop.Errors.ERROR_SUCCESS;
using (DisableMediaInsertionPrompt.Create())
{
if (!Interop.Kernel32.GetFileAttributesEx(path, Interop.Kernel32.GET_FILEEX_INFO_LEVELS.GetFileExInfoStandard, ref data))
{
errorCode = Marshal.GetLastWin32Error();
if (errorCode == Interop.Errors.ERROR_ACCESS_DENIED)
{
// Files that are marked for deletion will not let you GetFileAttributes,
// ERROR_ACCESS_DENIED is given back without filling out the data struct.
// FindFirstFile, however, will. Historically we always gave back attributes
// for marked-for-deletion files.
var findData = new Interop.Kernel32.WIN32_FIND_DATA();
using (SafeFindHandle handle = Interop.Kernel32.FindFirstFile(path, ref findData))
{
if (handle.IsInvalid)
{
errorCode = Marshal.GetLastWin32Error();
}
else
{
errorCode = Interop.Errors.ERROR_SUCCESS;
data.PopulateFrom(ref findData);
}
}
}
}
}
if (errorCode != Interop.Errors.ERROR_SUCCESS && !returnErrorOnNotFound)
{
switch (errorCode)
{
case Interop.Errors.ERROR_FILE_NOT_FOUND:
case Interop.Errors.ERROR_PATH_NOT_FOUND:
case Interop.Errors.ERROR_NOT_READY: // Removable media not ready
// Return default value for backward compatibility
data.dwFileAttributes = -1;
return(Interop.Errors.ERROR_SUCCESS);
}
}
return(errorCode);
}
internal static unsafe SafeFileHandle Open(string fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, long preallocationSize)
{
using (DisableMediaInsertionPrompt.Create())
{
// we don't use NtCreateFile as there is no public and reliable way
// of converting DOS to NT file paths (RtlDosPathNameToRelativeNtPathName_U_WithStatus is not documented)
SafeFileHandle fileHandle = CreateFile(fullPath, mode, access, share, options);
if (FileStreamHelpers.ShouldPreallocate(preallocationSize, access, mode))
{
Preallocate(fullPath, preallocationSize, fileHandle);
}
fileHandle.InitThreadPoolBindingIfNeeded();
return(fileHandle);
}
}
internal static unsafe SafeFileHandle Open(string fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, long preallocationSize)
{
using (DisableMediaInsertionPrompt.Create())
{
// we don't use NtCreateFile as there is no public and reliable way
// of converting DOS to NT file paths (RtlDosPathNameToRelativeNtPathName_U_WithStatus is not documented)
SafeFileHandle fileHandle = CreateFile(fullPath, mode, access, share, options);
if (preallocationSize > 0)
{
Preallocate(fullPath, preallocationSize, fileHandle);
}
if ((options & FileOptions.Asynchronous) != 0)
{
// the handle has not been exposed yet, so we don't need to aquire a lock
fileHandle.InitThreadPoolBinding();
}
return(fileHandle);
}
}
/// <summary>
/// Returns 0 on success, otherwise a Win32 error code. Note that
/// classes should use -1 as the uninitialized state for dataInitialized.
/// </summary>
/// <param name="returnErrorOnNotFound">Return the error code for not found errors?</param>
internal static int FillAttributeInfo(string path, ref Interop.Kernel32.WIN32_FILE_ATTRIBUTE_DATA data, bool returnErrorOnNotFound)
{
int errorCode = Interop.Errors.ERROR_SUCCESS;
// Neither GetFileAttributes or FindFirstFile like trailing separators
path = PathInternal.TrimEndingDirectorySeparator(path);
using (DisableMediaInsertionPrompt.Create())
{
if (!Interop.Kernel32.GetFileAttributesEx(path, Interop.Kernel32.GET_FILEEX_INFO_LEVELS.GetFileExInfoStandard, ref data))
{
errorCode = Marshal.GetLastWin32Error();
if (errorCode != Interop.Errors.ERROR_FILE_NOT_FOUND &&
errorCode != Interop.Errors.ERROR_PATH_NOT_FOUND &&
errorCode != Interop.Errors.ERROR_NOT_READY &&
errorCode != Interop.Errors.ERROR_INVALID_NAME &&
errorCode != Interop.Errors.ERROR_BAD_PATHNAME &&
errorCode != Interop.Errors.ERROR_BAD_NETPATH &&
errorCode != Interop.Errors.ERROR_BAD_NET_NAME &&
errorCode != Interop.Errors.ERROR_INVALID_PARAMETER &&
errorCode != Interop.Errors.ERROR_NETWORK_UNREACHABLE &&
errorCode != Interop.Errors.ERROR_NETWORK_ACCESS_DENIED &&
errorCode != Interop.Errors.ERROR_INVALID_HANDLE // eg from \\.\CON
)
{
// Assert so we can track down other cases (if any) to add to our test suite
Debug.Assert(errorCode == Interop.Errors.ERROR_ACCESS_DENIED || errorCode == Interop.Errors.ERROR_SHARING_VIOLATION,
$"Unexpected error code getting attributes {errorCode}");
// Files that are marked for deletion will not let you GetFileAttributes,
// ERROR_ACCESS_DENIED is given back without filling out the data struct.
// FindFirstFile, however, will. Historically we always gave back attributes
// for marked-for-deletion files.
//
// Another case where enumeration works is with special system files such as
// pagefile.sys that give back ERROR_SHARING_VIOLATION on GetAttributes.
//
// Ideally we'd only try again for known cases due to the potential performance
// hit. The last attempt to do so baked for nearly a year before we found the
// pagefile.sys case. As such we're probably stuck filtering out specific
// cases that we know we don't want to retry on.
var findData = new Interop.Kernel32.WIN32_FIND_DATA();
using (SafeFindHandle handle = Interop.Kernel32.FindFirstFile(path, ref findData))
{
if (handle.IsInvalid)
{
errorCode = Marshal.GetLastWin32Error();
}
else
{
errorCode = Interop.Errors.ERROR_SUCCESS;
data.PopulateFrom(ref findData);
}
}
}
}
}
if (errorCode != Interop.Errors.ERROR_SUCCESS && !returnErrorOnNotFound)
{
switch (errorCode)
{
case Interop.Errors.ERROR_FILE_NOT_FOUND:
case Interop.Errors.ERROR_PATH_NOT_FOUND:
case Interop.Errors.ERROR_NOT_READY: // Removable media not ready
// Return default value for backward compatibility
data.dwFileAttributes = -1;
return(Interop.Errors.ERROR_SUCCESS);
}
}
return(errorCode);
}
