Spying on COM Objects

Figure 3: Excerpt from log.cpp

	
/*-----------------------------------------------------------------

   FUNCTION: Logger::IntrerceptEntry

   PURPOSE:  Main entry of the interceptor of exported functions
             and COM methods. It will be called by our stubs.
      
   PARAMETERS:                   .
                                  
   ASM_APIFunctionStub * p_pStub  Pointer to the calling stub
   PDWORD  p_pdwFrame             function call stack frame
-----------------------------------------------------------------*/
/*static*/
void __stdcall Logger::IntrerceptEntry
(
    ASM_APIFunctionStub * p_pStub,
    PDWORD  p_pdwFrame
)
{
    char l_szPrintedParams[512];
    DWORD l_dwThis = 0;

    //__try
    //It will be nice to protect ourselves, 
    //but hard without C library
    {
        int l_iNestedLevel = 0;
        PrivateStackFrame * l_pFrame = g_Data.m_pRetMgr?
            g_Data.m_pRetMgr->pInterceptFunctionReturn
            (p_pStub, p_pdwFrame, &l_iNestedLevel) : NULL;

        *l_szPrintedParams = 0;
        if(l_pFrame)
        {
            if(p_pdwFrame)
               p_pdwFrame++;//Skip DWORD return address

            ParamProcContext l_Context(
                *((FunctionParameters *)p_pStub->m_dwParamsOffset),
                *l_pFrame, p_pdwFrame, FALSE);

            l_Context.iProcAllParams(l_szPrintedParams, 
                    sizeof(l_szPrintedParams));
            l_dwThis = l_Context.dwGetThis();
        }

        vLogFunction(p_pStub, NULL, l_szPrintedParams, 
            l_dwThis, l_iNestedLevel);
    
        // Patch the return address of this function so 
        // that returns to us
    }
    /*
    __except(1)
    {
        MYTRACE(TF_Error, 
            "ERROR : exception inside IntrerceptEntry");
    }
    */
}//void __stdcall IntrerceptEntry