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sys,dll: reparse point implementation: WIP

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This commit is contained in:
Bill Zissimopoulos
2016-08-15 04:53:11 -07:00
parent 7337f3c6cd
commit f7e0362350
7 changed files with 514 additions and 37 deletions
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59
src/sys/fsctl.c
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@ -103,7 +103,9 @@ static NTSTATUS FspFsvolFileSystemControlReparsePoint(
PVOID OutputBuffer = Irp->UserBuffer;
ULONG InputBufferLength = IrpSp->Parameters.FileSystemControl.InputBufferLength;
ULONG OutputBufferLength = IrpSp->Parameters.FileSystemControl.OutputBufferLength;
ULONG ReparseTag;
PREPARSE_DATA_BUFFER ReparseData;
PWSTR PathBuffer;
BOOLEAN TargetOnFileSystem = FALSE;
FSP_FSCTL_TRANSACT_REQ *Request;
ASSERT(FileNode == FileDesc->FileNode);
@ -123,16 +125,53 @@ static NTSTATUS FspFsvolFileSystemControlReparsePoint(
if (!NT_SUCCESS(Result))
return Result;
ReparseTag = ((PREPARSE_DATA_BUFFER)InputBuffer)->ReparseTag;
ReparseData = (PREPARSE_DATA_BUFFER)InputBuffer;
/* NTFS severely limits symbolic links; we will not do that unless our file system asks */
if (FsvolDeviceExtension->VolumeParams.ReparsePointsPrivilegeCheck)
if (IO_REPARSE_TAG_SYMLINK == ReparseData->ReparseTag)
{
if (IO_REPARSE_TAG_SYMLINK == ReparseTag &&
KernelMode != Irp->RequestorMode &&
SeSinglePrivilegeCheck(RtlConvertLongToLuid(SE_CREATE_SYMBOLIC_LINK_PRIVILEGE),
UserMode))
return STATUS_ACCESS_DENIED;
/* NTFS severely limits symbolic links; we will not do that unless our file system asks */
if (FsvolDeviceExtension->VolumeParams.ReparsePointsPrivilegeCheck)
{
if (KernelMode != Irp->RequestorMode &&
SeSinglePrivilegeCheck(RtlConvertLongToLuid(SE_CREATE_SYMBOLIC_LINK_PRIVILEGE),
UserMode))
return STATUS_ACCESS_DENIED;
}
/* determine if target resides on same device as link (convenience for user mode) */
PathBuffer = ReparseData->SymbolicLinkReparseBuffer.PathBuffer +
ReparseData->SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR);
if (ReparseData->SymbolicLinkReparseBuffer.SubstituteNameLength > 4 * sizeof(WCHAR) &&
'\\' == PathBuffer[0] &&
'?' == PathBuffer[1] &&
'?' == PathBuffer[2] &&
'\\' == PathBuffer[3])
{
UNICODE_STRING TargetDeviceName;
PFILE_OBJECT TargetDeviceFile;
PDEVICE_OBJECT TargetDeviceObject;
RtlInitEmptyUnicodeString(&TargetDeviceName,
PathBuffer,
ReparseData->SymbolicLinkReparseBuffer.SubstituteNameLength);
/* 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);
if (!NT_SUCCESS(Result))
goto target_check_exit;
TargetOnFileSystem = IoGetRelatedDeviceObject(FileObject) == TargetDeviceObject;
ObDereferenceObject(TargetDeviceFile);
target_check_exit:
;
}
}
}
else
@ -169,6 +208,8 @@ static NTSTATUS FspFsvolFileSystemControlReparsePoint(
Request->Req.FileSystemControl.Buffer.Size = (UINT16)InputBufferLength;
RtlCopyMemory(Request->Buffer + Request->Req.FileSystemControl.Buffer.Offset,
InputBuffer, InputBufferLength);
Request->Req.FileSystemControl.TargetOnFileSystem = TargetOnFileSystem;
}
FspFileNodeSetOwner(FileNode, Full, Request);