private void OpenSqlFileStream
(
string path,
byte[] transactionContext,
System.IO.FileAccess access,
System.IO.FileOptions options,
Int64 allocationSize
)
{
//-----------------------------------------------------------------
// precondition validation
// these should be checked by any caller of this method
// ensure we have validated and normalized the path before
Debug.Assert(path != null);
Debug.Assert(transactionContext != null);
if (access != FileAccess.Read && access != FileAccess.Write && access != FileAccess.ReadWrite)
{
throw ADP.ArgumentOutOfRange("access");
}
// FileOptions is a set of flags, so AND the given value against the set of values we do not support
if ((options & ~(FileOptions.WriteThrough | FileOptions.Asynchronous | FileOptions.RandomAccess | FileOptions.SequentialScan)) != 0)
{
throw ADP.ArgumentOutOfRange("options");
}
//-----------------------------------------------------------------
// normalize the provided path
// * compress path to remove any occurrences of '.' or '..'
// * trim whitespace from the beginning and end of the path
// * ensure that the path starts with '\\'
// * ensure that the path does not start with '\\.\'
// * ensure that the path is not longer than Int16.MaxValue
path = GetFullPathInternal(path);
// ensure the running code has permission to read/write the file
DemandAccessPermission(path, access);
FileFullEaInformation eaBuffer = null;
SecurityQualityOfService qos = null;
UnicodeString objectName = null;
Microsoft.Win32.SafeHandles.SafeFileHandle hFile = null;
int nDesiredAccess = UnsafeNativeMethods.FILE_READ_ATTRIBUTES | UnsafeNativeMethods.SYNCHRONIZE;
UInt32 dwCreateOptions = 0;
UInt32 dwCreateDisposition = 0;
System.IO.FileShare shareAccess = System.IO.FileShare.None;
switch (access)
{
case System.IO.FileAccess.Read:
nDesiredAccess |= UnsafeNativeMethods.FILE_READ_DATA;
shareAccess = System.IO.FileShare.Delete | System.IO.FileShare.ReadWrite;
dwCreateDisposition = (uint)UnsafeNativeMethods.CreationDisposition.FILE_OPEN;
break;
case System.IO.FileAccess.Write:
nDesiredAccess |= UnsafeNativeMethods.FILE_WRITE_DATA;
shareAccess = System.IO.FileShare.Delete | System.IO.FileShare.Read;
dwCreateDisposition = (uint)UnsafeNativeMethods.CreationDisposition.FILE_OVERWRITE;
break;
case System.IO.FileAccess.ReadWrite:
default:
// we validate the value of 'access' parameter in the beginning of this method
Debug.Assert(access == System.IO.FileAccess.ReadWrite);
nDesiredAccess |= UnsafeNativeMethods.FILE_READ_DATA | UnsafeNativeMethods.FILE_WRITE_DATA;
shareAccess = System.IO.FileShare.Delete | System.IO.FileShare.Read;
dwCreateDisposition = (uint)UnsafeNativeMethods.CreationDisposition.FILE_OVERWRITE;
break;
}
if ((options & System.IO.FileOptions.WriteThrough) != 0)
{
dwCreateOptions |= (uint)UnsafeNativeMethods.CreateOption.FILE_WRITE_THROUGH;
}
if ((options & System.IO.FileOptions.Asynchronous) == 0)
{
dwCreateOptions |= (uint)UnsafeNativeMethods.CreateOption.FILE_SYNCHRONOUS_IO_NONALERT;
}
if ((options & System.IO.FileOptions.SequentialScan) != 0)
{
dwCreateOptions |= (uint)UnsafeNativeMethods.CreateOption.FILE_SEQUENTIAL_ONLY;
}
if ((options & System.IO.FileOptions.RandomAccess) != 0)
{
dwCreateOptions |= (uint)UnsafeNativeMethods.CreateOption.FILE_RANDOM_ACCESS;
}
try
{
eaBuffer = new FileFullEaInformation(transactionContext);
qos = new SecurityQualityOfService(UnsafeNativeMethods.SecurityImpersonationLevel.SecurityAnonymous,
false, false);
// NOTE: the Name property is intended to reveal the publicly available moniker for the
// FILESTREAM attributed column data. We will not surface the internal processing that
// takes place to create the mappedPath.
string mappedPath = InitializeNtPath(path);
objectName = new UnicodeString(mappedPath);
UnsafeNativeMethods.OBJECT_ATTRIBUTES oa;
oa.length = Marshal.SizeOf(typeof(UnsafeNativeMethods.OBJECT_ATTRIBUTES));
oa.rootDirectory = IntPtr.Zero;
oa.attributes = (int)UnsafeNativeMethods.Attributes.CaseInsensitive;
oa.securityDescriptor = IntPtr.Zero;
oa.securityQualityOfService = qos;
oa.objectName = objectName;
UnsafeNativeMethods.IO_STATUS_BLOCK ioStatusBlock;
uint oldMode;
uint retval = 0;
UnsafeNativeMethods.SetErrorModeWrapper(UnsafeNativeMethods.SEM_FAILCRITICALERRORS, out oldMode);
try
{
SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.SqlFileStream.OpenSqlFileStream|ADV> {0}, desiredAccess=0x{1}, allocationSize={2}, " +
"fileAttributes=0x{3}, shareAccess=0x{4}, dwCreateDisposition=0x{5}, createOptions=0x{ dwCreateOptions}", ObjectID, (int)nDesiredAccess, allocationSize, 0, (int)shareAccess, dwCreateDisposition);
retval = UnsafeNativeMethods.NtCreateFile(out hFile, nDesiredAccess,
ref oa, out ioStatusBlock, ref allocationSize,
0, shareAccess, dwCreateDisposition, dwCreateOptions,
eaBuffer, (uint)eaBuffer.Length);
}
finally
{
UnsafeNativeMethods.SetErrorModeWrapper(oldMode, out oldMode);
}
switch (retval)
{
case 0:
break;
case UnsafeNativeMethods.STATUS_SHARING_VIOLATION:
throw ADP.InvalidOperation(StringsHelper.GetString(StringsHelper.SqlFileStream_FileAlreadyInTransaction));
case UnsafeNativeMethods.STATUS_INVALID_PARAMETER:
throw ADP.Argument(StringsHelper.GetString(StringsHelper.SqlFileStream_InvalidParameter));
case UnsafeNativeMethods.STATUS_OBJECT_NAME_NOT_FOUND:
{
System.IO.DirectoryNotFoundException e = new System.IO.DirectoryNotFoundException();
ADP.TraceExceptionAsReturnValue(e);
throw e;
}
default:
{
uint error = UnsafeNativeMethods.RtlNtStatusToDosError(retval);
if (error == UnsafeNativeMethods.ERROR_MR_MID_NOT_FOUND)
{
// status code could not be mapped to a Win32 error code
error = retval;
}
System.ComponentModel.Win32Exception e = new System.ComponentModel.Win32Exception(unchecked ((int)error));
ADP.TraceExceptionAsReturnValue(e);
throw e;
}
}
if (hFile.IsInvalid)
{
System.ComponentModel.Win32Exception e = new System.ComponentModel.Win32Exception(UnsafeNativeMethods.ERROR_INVALID_HANDLE);
ADP.TraceExceptionAsReturnValue(e);
throw e;
}
UnsafeNativeMethods.FileType fileType = UnsafeNativeMethods.GetFileType(hFile);
if (fileType != UnsafeNativeMethods.FileType.Disk)
{
hFile.Dispose();
throw ADP.Argument(StringsHelper.GetString(StringsHelper.SqlFileStream_PathNotValidDiskResource));
}
// if the user is opening the SQL FileStream in read/write mode, we assume that they want to scan
// through current data and then append new data to the end, so we need to tell SQL Server to preserve
// the existing file contents.
if (access == System.IO.FileAccess.ReadWrite)
{
uint ioControlCode = UnsafeNativeMethods.CTL_CODE(UnsafeNativeMethods.FILE_DEVICE_FILE_SYSTEM,
IoControlCodeFunctionCode, (byte)UnsafeNativeMethods.Method.METHOD_BUFFERED,
(byte)UnsafeNativeMethods.Access.FILE_ANY_ACCESS);
uint cbBytesReturned = 0;
if (!UnsafeNativeMethods.DeviceIoControl(hFile, ioControlCode, IntPtr.Zero, 0, IntPtr.Zero, 0, out cbBytesReturned, IntPtr.Zero))
{
System.ComponentModel.Win32Exception e = new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
ADP.TraceExceptionAsReturnValue(e);
throw e;
}
}
// now that we've successfully opened a handle on the path and verified that it is a file,
// use the SafeFileHandle to initialize our internal System.IO.FileStream instance
// NOTE: need to assert UnmanagedCode permissions for this constructor. This is relatively benign
// in that we've done much the same validation as in the FileStream(string path, ...) ctor case
// most notably, validating that the handle type corresponds to an on-disk file.
bool bRevertAssert = false;
try
{
SecurityPermission sp = new SecurityPermission(SecurityPermissionFlag.UnmanagedCode);
sp.Assert();
bRevertAssert = true;
System.Diagnostics.Debug.Assert(m_fs == null);
m_fs = new System.IO.FileStream(hFile, access, DefaultBufferSize, ((options & System.IO.FileOptions.Asynchronous) != 0));
}
finally
{
if (bRevertAssert)
{
SecurityPermission.RevertAssert();
}
}
}
catch
{
if (hFile != null && !hFile.IsInvalid)
{
hFile.Dispose();
}
throw;
}
finally
{
if (eaBuffer != null)
{
eaBuffer.Dispose();
eaBuffer = null;
}
if (qos != null)
{
qos.Dispose();
qos = null;
}
if (objectName != null)
{
objectName.Dispose();
objectName = null;
}
}
}