passing reference object from win32 dll to mfc dll - winapi

Question

I have hooked a exported MFC DLL function using naked function.
the definition of naked function is as follows :
__declspec(naked)
static void __cdecl GenericHook(void* __this,class CScrollViewAccess* objParam1, class CRect& objParam2,unsigned int iParam1, unsigned long iParam2, char* szParam1,
void* vParam1, class CFont* objParam3,class CFont* objParam4,
class CBrush* objParam5)
{ /*function body start*/
__asm pushad; /* first "argument", which is also used to store registers */
__asm push ecx; /* padding so that ebp+8 refers to the first "argument" */
/* set up standard prologue */
__asm push ebp;
__asm mov ebp, esp;
__asm sub esp, __LOCAL_SIZE;
if(flg == false)
{
//RECT* rct = reinterpret_cast(&objParam2);
hInst = LoadLibrary("C:\\Sample.dll"); /// MFC Dll
funcPTR = (CMYCLASS_)(((int)hInst)+((int)0x00001032));
funcPTR(__this,objParam2);
/* standard epilogue */
__asm mov esp, ebp;
__asm pop ebp;
__asm pop ecx; /* clear padding */
__asm popad; /* clear first "argument" */
__asm jmp [Trampoline];
}
/*function body end*/
The Mfc dll has following function:
void CMyClass::returnRect(class CRect& objParam)
{
int width = objParam.Width();
int height = objParam.Height();
CPoint pt = objParam.TopLeft();
FILE* fp;
char szEnter[6] = {13,0,10,0,0,0};
fp = fopen("c:\\LogFolder\\log.txt","ab+");
fprintf(fp,"Width: %d Height: %d X co-ord: %d Y co-ord: %d\n%s",width,height,pt.x,pt.y,szEnter);
fclose(fp);
}
after passing CRect& parameter to the MFC DLL the values logged are wrong.
How to process the reference object?

Answer 1

I have solved this hooking problem as follows:
extern "C" __declspec(naked) __declspec(dllexport) void __stdcall GenericHook()
{ /*function body start*/
/* set up standard prologue */
__asm push ebp;
__asm mov ebp, esp;
__asm pushad;
// __asm sub esp, __LOCAL_SIZE; // Grow stack size
__asm mov eax,[ebp+4]; //Return Address
__asm mov objParam1,eax;
__asm mov eax,DWORD ptr[ebp+8]; //arg1
__asm mov objParam2,eax;
__asm mov eax,DWORD ptr[ebp+12]; //arg2
__asm mov objParam3,eax;
__asm mov eax,DWORD ptr[ebp+16]; //arg3
__asm mov objParam4,eax;
__asm mov eax,DWORD ptr[ebp+20]; //arg4
__asm mov objParam5,eax;
/*-------------PROCESSING START---------------------*/
fp = fopen("c:\\LogFolder\\log.txt","ab+");
fprintf(fp,"arg1: %lu~arg2: %lu~arg3: %lu~arg4: %lu~ar5: %lu\n",objParam1,objParam2,objParam3,objParam4,objParam5);
fprintf(fp,"==========================================================================\n\n");
fclose(fp);
/*-------------PROCESSING END-----------------------*/
/* standard epilogue
__asm add esp, __LOCAL_SIZE;*/
__asm popad;
__asm mov esp, ebp;
__asm pop ebp;
__asm jmp [Trampoline];
}