C# Enable/disable Windows 7 / Windows 7 Embedded Firewall

Question

I am working on a project where it must be possible to enable/disable the integrated Windows Firewall of a Windows 7 Embedded system by programm.

using the code:

private static INetFwPolicy2 getCurrPolicy()
    {
        INetFwPolicy2 fwPolicy2;
        Type tNetFwPolicy2 = Type.GetTypeFromProgID("HNetCfg.FwPolicy2");
        if (tNetFwPolicy2 != null)
            fwPolicy2 = (INetFwPolicy2)Activator.CreateInstance(tNetFwPolicy2);
        else
            return null;
        return fwPolicy2;
    }

    public static bool GetFirewallStatus()
    {
        bool result = false;
        try
        {
            INetFwPolicy2 fwPolicy2 = getCurrPolicy();
            NET_FW_PROFILE_TYPE2_ fwCurrentProfileTypes;
            //read Current Profile Types (only to increase Performace)
            //avoids access on CurrentProfileTypes from each Property
            fwCurrentProfileTypes = NET_FW_PROFILE_TYPE2_)fwPolicy2.CurrentProfileTypes;
            result = (fwPolicy2.get_FirewallEnabled(fwCurrentProfileTypes));
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
        return result;
    }

    public static void SetFirewallStatus(bool newStatus)
    {
        try
        {
            NET_FW_PROFILE_TYPE2_ fwCurrentProfileTypes;
            INetFwPolicy2 currPolicy = getCurrPolicy();
            //read Current Profile Types (only to increase Performace)
            //avoids access on CurrentProfileTypes from each Property
            fwCurrentProfileTypes = NET_FW_PROFILE_TYPE2_)currPolicy.CurrentProfileTypes;
            currPolicy.set_FirewallEnabled(fwCurrentProfileTypes, newStatus);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

What happens is that at every function call of the currPolicy objects i get the following message:

System.ArgumentException: Value does not fall within the expected range.

Now there is my question: Why do I get this error and how can I make it work?

Thanks!

Answer 1

After reading the documentation again, i came across the line "When you pass a profile type obtained from the CurrentProfileTypes property, make sure that you pass only one profile type to get_FirewallEnabled and put_FirewallEnabled. Note that get_CurrentProfileTypes can return multiple profiles."

(http://msdn.microsoft.com/en-us/library/windows/desktop/aa365316%28v=vs.85%29.aspx)

And yes, i have actually got more than one profile type returned. So the API works when you only pass one profile to the get and set methods of FirewallEnabled. e.g.:

result = (fwPolicy2.get_FirewallEnabled(NET_FW_PROFILE_TYPE2_.NET_FW_PROFILE2_PUBLIC));