CODEWITHSUNDEEP
c++windowswmiprovider
SaKu
SaKu

Reputation: 11

Supplying Data to WMI by Writing a Provider

I am new to c++ and I am trying to develop a WMI provider in windows. After few searches I have come across a documentation of MSDN (https://learn.microsoft.com/en-us/windows/win32/wmisdk/supplying-data-to-wmi-by-writing-a-provider) I have followed all the steps and finally used the same example they have given, still it not go beyond the DllRegisterServer method after I register the dll using regsvr32 command. But it says after registering the dll wmi instance should be there.

My guess is I am missing something from the documentation or I am not understanding basic of Dll.

What I want is to call Initialize method in InstProv file after the registration process is success.

Please excuse me if this is a lame question, since I could not find much resources under WMI Providers thought of raise my problem here.

Here is my DllRegisterServer method

STDAPI DllRegisterServer(void)
{   
    char       szID[128];
    WCHAR      wcID[128];
    char       szCLSID[128];
    TCHAR       szModule[MAX_PATH + 1];
    const char * pName = "WMI Sample Instance Provider";
    const char * pModel = "Both";
    HKEY hKey1, hKey2;


    // Create the path.

    memset(wcID, NULL, sizeof(wcID));
    memset(szID, NULL, sizeof(szID)); 
    StringFromGUID2(CLSID_instprovider, wcID, sizeof(wcID)/sizeof(WCHAR));
    wcstombs(szID, wcID, sizeof(szID)); 
    StringCbCopy(szCLSID, sizeof(szCLSID), "Software\\classes\\CLSID\\");
    StringCbCat(szCLSID, sizeof(szCLSID), (LPCTSTR)szID);

    // Create entries under CLSID

    LONG lRet = RegCreateKeyEx( HKEY_LOCAL_MACHINE, 
                                szCLSID, 
                                0, 
                                NULL,
                                REG_OPTION_NON_VOLATILE, 
                                KEY_WRITE, 
                                NULL, 
                                &hKey1, 
                                NULL );
    if (lRet != ERROR_SUCCESS)
    {
        return E_FAIL;
    }

    lRet = RegSetValueEx(hKey1, NULL, 0, REG_SZ, (BYTE *)pName, strlen(pName)+1);
    if (lRet != ERROR_SUCCESS)
    {
        RegCloseKey(hKey1);
        return E_FAIL;
    }

    lRet = RegCreateKeyEx( hKey1, "InprocServer32", 0, NULL, REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &hKey2, NULL );
    if (lRet != ERROR_SUCCESS)
    {
        RegCloseKey(hKey1);
        return E_FAIL;
    }

    memset(&szModule, NULL, sizeof(szModule));
    GetModuleFileName(ghModule, szModule, sizeof(szModule)/sizeof(TCHAR) - 1);

    lRet = RegSetValueEx(hKey2, NULL, 0, REG_SZ, (BYTE *)szModule, strlen(szModule)+1);
    if (lRet != ERROR_SUCCESS)
    {
        RegCloseKey(hKey2);
        RegCloseKey(hKey1);
        return E_FAIL;
    }
    
    lRet = RegSetValueEx(hKey2, "ThreadingModel", 0, REG_SZ, (BYTE *)pModel, strlen(pModel)+1);
    if (lRet != ERROR_SUCCESS)
    {
        RegCloseKey(hKey2);
        RegCloseKey(hKey1);
        return E_FAIL;
    }
    RegCloseKey(hKey1);
    RegCloseKey(hKey2);
    return NOERROR;
}

Upvotes: 1

Views: 219

Answers (1)

Oliver
Oliver

Reputation: 1

Same problem here, it didn't work out for me using the sample code on that page. So I used the WMI provider framework from Gwyn Cole link to home page where one can download the framework. It works like a charm. It is based on ATL, so it is very maintainable in my humble opinion.

It also worked to create a provider with MI, but it had some stability issues, which will likely be my fault. But since WMI is deprecated, MI is the way to go. It's pretty interesting to find, that Microsoft developed an open source MI framework for Linux, which quite much overlaps with MI for Windows GITHub

Upvotes: 0

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