Windows Firewall interfaces, INetFwProducts, and InetFwProduct.

Article
09/19/2013

Jeff here again. Today I have samples of the Windows Firewall interfaces, INetFwProducts, and InetFwProduct.

#include "stdafx.h"
#include <windows.h>
#include <stdio.h>
#include <netfw.h>

#pragma comment( lib, "ole32.lib" )

// Forward declarations

HRESULT FWProductsCOMInitialize(INetFwProducts** ppFwProducts);

int _tmain(int argc, _TCHAR* argv[])
{
    HRESULT hrComInit = S_OK;
    HRESULT hr = S_OK;
    long cnt = 0;
    INetFwProduct *pFwProduct = NULL;
    INetFwProducts *pFwProducts = NULL;

// Initialize COM.

hrComInit = CoInitializeEx(0, COINIT_APARTMENTTHREADED );

    if (hrComInit != RPC_E_CHANGED_MODE)
    {
        if (FAILED(hrComInit))
        {
            printf("CoInitializeEx failed: 0x%08lx\n", hrComInit);
            goto Cleanup;
        }
    }

hr = FWProductsCOMInitialize(&pFwProducts);

    if (FAILED(hr))
    {
        goto Cleanup;
    }

hr = pFwProducts->get_Count(&cnt);

       if (SUCCEEDED(hr))
       {
              printf("get_Count: %d\n",cnt);
              hr = pFwProducts->Item(cnt - 1 , &pFwProduct);

              if (SUCCEEDED(hr))
              {
                     BSTR bsDisplayName = NULL;
                     hr = pFwProduct->get_DisplayName(&bsDisplayName);

                     if (SUCCEEDED(hr))
                     {
                           printf("Display name: %S\n", bsDisplayName);
                           SysFreeString(bsDisplayName);
                     }

BSTR bsExe = NULL;

hr = pFwProduct->get_PathToSignedProductExe(&bsExe);

if (SUCCEEDED(hr))
{

printf("Path to signed exe: %S\n", bsExe);
SysFreeString(bsExe);

}

IUnknown *pUnkNewEnum;
hr = pFwProducts->get__NewEnum(&pUnkNewEnum);

if (SUCCEEDED(hr))
{

IEnumVARIANT*pUnkVariant;

hr = pUnkNewEnum->QueryInterface(IID_IEnumVARIANT,(void**) &pUnkVariant);

if (SUCCEEDED(hr))
{

do
{

                                         ULONG celt=1;
                                         VARIANT var1[1];
                                         VariantInit(&var1[0]);
                                         ULONG CeltReturned=0;

hr = pUnkVariant->Next(celt,&var1[0],&CeltReturned);

if (SUCCEEDED(hr))
{

                                                if(S_FALSE==hr)
                                                {
                                                      //noop possible

                                                }
                                                else
                                                {

switch (var1[0].vt)
{

case VT_UNKNOWN:
case VT_DISPATCH:

                                                              {
                                                                     INetFwProduct *pFwProductQI = NULL;
                                                                     HRESULT hrQI;
                                                                     hrQI =var1[0].punkVal->QueryInterface(IID_INetFwProduct, (void**)&pFwProductQI);

if(SUCCEEDED(hrQI))
{

HRESULT hrDisplayName;

BSTR displayNameEnum;

hrDisplayName = pFwProductQI->get_DisplayName(&displayNameEnum);

if(SUCCEEDED(hrQI))

{
printf("\nEnum Display Name: %S\n", displayNameEnum);

//clean-up

SysFreeString(displayNameEnum);

VariantClear(&var1[0]);

}

break;

default:

break;

}

while(hr !=S_FALSE && !FAILED(hr));

}

Cleanup:

// Release INetFwPolicy2

    if (pFwProduct != NULL)
    {
        pFwProduct->Release();
    }

// Uninitialize COM.

    if (SUCCEEDED(hrComInit))
    {
        CoUninitialize();

}

return 0;

}

HRESULT FWProductsCOMInitialize(INetFwProducts** ppFwProducts)

{
HRESULT hr = S_OK;

hr = CoCreateInstance( __uuidof(NetFwProducts),

NULL,

CLSCTX_INPROC_SERVER,

__uuidof(INetFwProducts),

(void**)ppFwProducts);

     if (FAILED(hr))
    {
        printf("CoCreateInstance for INetFwProducts failed: 0x%08lx\n", hr);

goto Cleanup;

}

Cleanup:

return hr;

}

For these APIs to work, the Windows Firewall Service needs to be running, otherwise get_Count() returns a bogus number. These APIs only work with 3^rd party firewalls, they won’t return the Microsoft firewall.

/Jeff

Windows Firewall interfaces, INetFwProducts, and InetFwProduct.

Additional resources