From 12c4e07a1840c03e6bc3907f3482a9ec4ce57d0c Mon Sep 17 00:00:00 2001
From: Dibyamartanda Samanta <dibyaxp@noreply.codingworkshop.git>
Date: Fri, 17 May 2024 17:03:52 +0200
Subject: [PATCH] [NTOSKRNL:CC] Use standard FSRTL routines for Write/Read

CcMdlReadComplete, CcMdlWriteComplete, Older Macros are WDM Header dependent
---
 NTOSKRNL/CC/ccmdlhandler.cpp | 57 +++++++++++++++++++++++++-----------
 1 file changed, 40 insertions(+), 17 deletions(-)

diff --git a/NTOSKRNL/CC/ccmdlhandler.cpp b/NTOSKRNL/CC/ccmdlhandler.cpp
index 5e4fc8b..86b73e2 100644
--- a/NTOSKRNL/CC/ccmdlhandler.cpp
+++ b/NTOSKRNL/CC/ccmdlhandler.cpp
@@ -207,15 +207,26 @@ NTAPI
 CcMdlReadComplete(IN PFILE_OBJECT FileObject,
                   IN PMDL MdlChain)
 {
-    PDEVICE_OBJECT RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
-    FAST_IO_DISPATCH FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
-	/* Start Faster MDL Operator if Suceeds , don't execute slower CcMdlReadComplete2*/
-	BOOL MdlReadComplete_FLag =  (*PFAST_IO_MDL_READ_COMPLETE) (  FileObject, MdlChain, RelatedDeviceObject);
-    
-	if ( !FastIoDispatch|| FastIoDispatch->SizeOfFastIoDispatch <= MAXIO_DISPATCH|| (MdlReadComplete_FLag = FastIoDispatch->MdlReadComplete) == 0|| !MdlReadComplete_FLag )
-   {
-    CcMdlReadComplete2(NULL,MdlChain);
-   }
+    PDEVICE_OBJECT RelatedDeviceObject = nullptr;
+    PFAST_IO_DISPATCH FastIoDispatch = nullptr;
+    IO_MDLREAD_COMPLETE_ROUTINE MdlReadComplete;
+
+    RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
+    FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
+    if(MdlChain == nullptr)
+      {   DBGPRINT("Invalid MDLChain \n");
+           return;
+      }
+    if (FastIoDispatch &&
+        FastIoDispatch->SizeOfFastIoDispatch >= sizeof(FAST_IO_DISPATCH) &&
+        (MdlReadComplete = FastIoDispatch->MdlReadComplete) != NULL &&
+        MdlReadComplete(FileObject, MdlChain, RelatedDeviceObject))
+    {
+        /* Faster Fast I/O MDL path successful, if it fails, we will go for our slower implementation*/
+        return;
+    }
+
+    CcMdlReadComplete2(FileObject, MdlChain);
 }
 
 VOID
@@ -250,14 +261,26 @@ CcMdlWriteComplete(IN PFILE_OBJECT FileObject,
                    IN PMDL MdlChain)
 {
 	
-	DEVICE_OBJECT RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
-    FAST_IO_DISPATCH FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
-	BOOL MdlWriteComplete_FLag = (*PFAST_IO_MDL_WRITE_COMPLETE) ( FileObject, FileOffset, MdlChain, RelatedDeviceObject);
-		/* Start Faster MDL Operator if Suceeds , don't execute slower CcMdlReadComplete2*/
-	if (!FastIoDispatch|| FastIoDispatch->SizeOfFastIoDispatch <= MAXIO_DISPATCH|| (MdlWriteComplete_FLag = FastIoDispatch->MdlWriteComplete) == 0||  !MdlWriteComplete_FLag)
-  {
-     CcMdlWriteComplete2(FileObject,FileOffset,MdlChain);
-  }
+	  PDEVICE_OBJECT RelatedDeviceObject = nullptr;
+    PFAST_IO_DISPATCH FastIoDispatch = nullptr;
+    IO_MDLWRITE_COMPLETE_ROUTINE MdlWriteComplete;
+    if(MdlChain == nullptr)
+    {   DBGPRINT("Invalid MDLChain \n");
+    return;
+    }
+    RelatedDeviceObject = IoGetRelatedDeviceObject(FileObject);
+    FastIoDispatch = RelatedDeviceObject->DriverObject->FastIoDispatch;
+
+    if (FastIoDispatch &&
+        FastIoDispatch->SizeOfFastIoDispatch >= sizeof(FAST_IO_DISPATCH) &&
+        (MdlWriteComplete = FastIoDispatch->MdlWriteComplete) != NULL &&
+        MdlWriteComplete(FileObject, FileOffset, MdlChain, RelatedDeviceObject))
+    {
+        /* Faster Fast I/O MDL path successful, if it fails, we will go for our slower implementation*/
+        return;
+    }
+
+    CcMdlWriteComplete2(FileObject, FileOffset, MdlChain);
 }
 
 VOID