[NTOSKRNL:CC] Implemented CcFindBitmapRangeToDirty

NTOSKRNL/CC/ccutil.cpp

@@ -6,6 +6,72 @@
  * COPYRIGHT:  2023-2029 Dibymartanda Samanta <>
  */ 
 
+class BitmapRangeManager {
+private:
+static constexpr LONGLONG CalculateBasePage(LONGLONG InputPage) {
+        return (InputPage & ~(0x1000 - 1));
+    }
+public:
+    static PBITMAP_RANGE FindBitmapRangeToDirty(PMBCB Mbcb, LONGLONG InputPage, PULONG* pBitmap) {
+        PBITMAP_RANGE CurrentRange = nullptr;
+        PBITMAP_RANGE NewRange = nullptr;
+        PLIST_ENTRY HeadList = nullptr;
+        LONGLONG BasePage = {0};
+
+
+        HeadList = &Mbcb->BitmapRanges;
+        BasePage = CalculateBasePage(InputPage);
+
+        CurrentRange = CONTAINING_RECORD(Mbcb->BitmapRanges.Flink, BITMAP_RANGE, Links);
+
+        while(true){
+            if (BasePage == CurrentRange->BasePage)
+                return CurrentRange;
+
+            if (CurrentRange->DirtyPages || NewRange) {
+                if (BasePage > CurrentRange->BasePage)
+                    HeadList = &CurrentRange->Links;
+            }
+            else {
+                NewRange = CurrentRange;
+            }
+
+            if (CurrentRange->Links.Flink == &Mbcb->BitmapRanges)
+                break;
+
+            CurrentRange = CONTAINING_RECORD(CurrentRange->Links.Flink, BITMAP_RANGE, Links);
+
+            if (CurrentRange->BasePage > BasePage && NewRange)
+                break;
+        } 
+
+        if (NewRange) {
+            RemoveEntryList(&NewRange->Links);
+        }
+        else {
+            NewRange = reinterpret_cast<PBITMAP_RANGE>(ExAllocatePoolWithTag(NonPagedPool, sizeof(*NewRange), 'rBcC'));
+            if (!NewRange) {
+                return nullptr;
+            }
+
+            RtlZeroMemory(NewRange, sizeof(*NewRange));
+        }
+
+        InsertHeadList(HeadList, &NewRange->Links);
+
+        NewRange->BasePage = BasePage;
+        NewRange->FirstDirtyPage = 0xFFFFFFFF;
+        NewRange->LastDirtyPage = 0;
+
+        if (!NewRange->Bitmap) {
+
+            NewRange->Bitmap = *pBitmap;
+            *pBitmap = nullptr;
+        }
+
+        return NewRange;
+    }
+};
 
 /*  Internal Functions */
 LONG
@@ -27,7 +93,7 @@ CcFindBitmapRangeToDirty(
     _In_ LONGLONG InputPage,
     _Inout_ PULONG* PBITMAP)
 {
-    NT_DBGBREAK("UNIMPLEMENTED\n");
+    return BitmapRangeManager::FindBitmapRangeToDirty(Mbcb, InputPage, pBitmap);
     
 }