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sys,dll: reparse point testing

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This commit is contained in:
Bill Zissimopoulos
2016-09-10 23:00:55 -07:00
parent 0d25e73364
commit af2cc10c15
8 changed files with 171 additions and 112 deletions
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41
src/sys/fsctl.c
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@ -109,8 +109,9 @@ static NTSTATUS FspFsvolFileSystemControlReparsePoint(
ULONG InputBufferLength = IrpSp->Parameters.FileSystemControl.InputBufferLength;
ULONG OutputBufferLength = IrpSp->Parameters.FileSystemControl.OutputBufferLength;
PREPARSE_DATA_BUFFER ReparseData;
PWSTR PathBuffer;
BOOLEAN TargetOnFileSystem = FALSE;
PWSTR ReparseTargetPath;
USHORT ReparseTargetPathLength;
UINT16 TargetOnFileSystem = 0;
FSP_FSCTL_TRANSACT_REQ *Request;
ASSERT(FileNode == FileDesc->FileNode);
@ -139,36 +140,28 @@ static NTSTATUS FspFsvolFileSystemControlReparsePoint(
return STATUS_PRIVILEGE_NOT_HELD;
}
/* determine if target resides on same device as link (convenience for user mode) */
PathBuffer = ReparseData->SymbolicLinkReparseBuffer.PathBuffer +
ReparseTargetPath = ReparseData->SymbolicLinkReparseBuffer.PathBuffer +
ReparseData->SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR);
if (ReparseData->SymbolicLinkReparseBuffer.SubstituteNameLength > 4 * sizeof(WCHAR) &&
'\\' == PathBuffer[0] &&
'?' == PathBuffer[1] &&
'?' == PathBuffer[2] &&
'\\' == PathBuffer[3])
ReparseTargetPathLength = ReparseData->SymbolicLinkReparseBuffer.SubstituteNameLength;
/* is this an absolute path? determine if target resides on same device as link */
if (ReparseTargetPathLength >= sizeof(WCHAR) && L'\\' == ReparseTargetPath[0])
{
UNICODE_STRING TargetDeviceName;
PFILE_OBJECT TargetDeviceFile;
UNICODE_STRING TargetObjectName;
PDEVICE_OBJECT TargetDeviceObject;
ULONG TargetFileNameIndex;
RtlInitEmptyUnicodeString(&TargetDeviceName,
PathBuffer,
ReparseData->SymbolicLinkReparseBuffer.SubstituteNameLength);
TargetObjectName.Length = TargetObjectName.MaximumLength = ReparseTargetPathLength;
TargetObjectName.Buffer = ReparseTargetPath;
/* the first path component is assumed to be the device name */
TargetDeviceName.Length = 4 * sizeof(WCHAR);
while (TargetDeviceName.Length < TargetDeviceName.MaximumLength &&
'\\' != TargetDeviceName.Buffer[TargetDeviceName.Length / sizeof(WCHAR)])
TargetDeviceName.Length += sizeof(WCHAR);
Result = IoGetDeviceObjectPointer(&TargetDeviceName,
FILE_READ_ATTRIBUTES, &TargetDeviceFile, &TargetDeviceObject);
Result = FspGetDeviceObjectByName(&TargetObjectName, FILE_READ_DATA,
&TargetFileNameIndex, &TargetDeviceObject);
if (!NT_SUCCESS(Result))
goto target_check_exit;
TargetOnFileSystem = IoGetRelatedDeviceObject(FileObject) == TargetDeviceObject;
ObDereferenceObject(TargetDeviceFile);
TargetOnFileSystem = IoGetRelatedDeviceObject(FileObject) == TargetDeviceObject ?
(UINT16)TargetFileNameIndex : 0;
ObDereferenceObject(TargetDeviceObject);
target_check_exit:
;