Managing Firewall Rules via INetFwPolicy2

[Dragokas]

Below provided several examples how to work with INetFwPolicy2 interface to setup Windows Firewall for your application.

You'll have to connect type library via Project - References - NetFW.TLB

Option Explicit

Private Sub Form_Load()
    'Adding program to list of allowed applications (inbound & outbound) 
    Firewall_AddAllowedProgram "app", "c:\path\app.exe"

    'Checking if program is allowed 
    Debug.Print Firewall_IsAllowedProgram("c:\path\app.exe")

    'Disabling firewall rule by program path 
    Firewall_DisableProgram "c:\path\app.exe"

    'Removing firewall rule by name 
    Firewall_RemoveRuleName "app"
End Sub

Public Function Firewall_AddAllowedProgram(RuleName As String, ProgramPath As String) As Boolean

    On Error GoTo ErrH

    Dim pFwNetFwPolicy2 As New NetFwPolicy2
    Dim pFwRules As INetFwRules
    Dim pFwRule As NetFwRule

    Set pFwRules = pFwNetFwPolicy2.Rules

    Firewall_RemoveRuleName RuleName
    Firewall_DisableProgram ProgramPath

    Set pFwRule = New NetFwRule
    With pFwRule
        .Action = NET_FW_ACTION_ALLOW
        .ApplicationName = ProgramPath
        .Direction = NET_FW_RULE_DIR_OUT
        .Enabled = True
        .InterfaceTypes = "All"
        .LocalAddresses = "*"
        .Name = RuleName
        .Profiles = NET_FW_PROFILE2_ALL
        .Protocol = NET_FW_IP_PROTOCOL_ANY
        .RemoteAddresses = "*"
    End With

    pFwRules.Add pFwRule

    Set pFwRule = New NetFwRule
    With pFwRule
        .Action = NET_FW_ACTION_ALLOW
        .ApplicationName = ProgramPath
        .Direction = NET_FW_RULE_DIR_IN
        .Enabled = True
        .InterfaceTypes = "All"
        .LocalAddresses = "*"
        .Name = RuleName
        .Profiles = NET_FW_PROFILE2_ALL
        .Protocol = NET_FW_IP_PROTOCOL_ANY
        .RemoteAddresses = "*"
    End With

    pFwRules.Add pFwRule
    Set pFwNetFwPolicy2 = Nothing

    Firewall_AddAllowedProgram = True
    Exit Function
ErrH:
    Debug.Print "ERROR: in " & "Firewall_AddAllowedProgram" & ". Err # " & Err.Number & " (" & Err.LastDllError & ") - " & Err.Description
End Function

Public Function Firewall_RemoveRuleName(RuleName As String) As Boolean

    On Error GoTo ErrH

    Dim pFwNetFwPolicy2 As New NetFwPolicy2
    Dim pFwRules As INetFwRules

    Set pFwRules = pFwNetFwPolicy2.Rules
    pFwRules.Remove RuleName
    pFwRules.Remove RuleName

    Set pFwNetFwPolicy2 = Nothing

    Firewall_RemoveRuleName = True
    Exit Function
ErrH:
    Debug.Print "ERROR: in " & "Firewall_RemoveRuleName" & ". Err # " & Err.Number & " (" & Err.LastDllError & ") - " & Err.Description
End Function

Public Function Firewall_DisableProgram(sPath As String) As Boolean

    On Error GoTo ErrH

    Dim pFwNetFwPolicy2 As New NetFwPolicy2
    Dim pFwRules As INetFwRules
    Dim pFwRule As NetFwRule

    Set pFwRules = pFwNetFwPolicy2.Rules
    For Each pFwRule In pFwRules
        With pFwRule
            If StrComp(.ApplicationName, sPath, 1) = 0 Then
                .Enabled = False
            End If
        End With
    Next

    Set pFwNetFwPolicy2 = Nothing

    Firewall_DisableProgram = True
    Exit Function
ErrH:
    Debug.Print "ERROR: in " & "Firewall_DisableProgram" & ". Err # " & Err.Number & " (" & Err.LastDllError & ") - " & Err.Description
End Function

Public Function Firewall_IsAllowedProgram(sPath As String) As Boolean

    On Error GoTo ErrH

    Dim pFwNetFwPolicy2 As New NetFwPolicy2
    Dim pFwRules As INetFwRules
    Dim pFwRule As NetFwRule

    Set pFwRules = pFwNetFwPolicy2.Rules
    For Each pFwRule In pFwRules
        With pFwRule
            If StrComp(.ApplicationName, sPath, 1) = 0 Then
                If .Enabled And .Action = NET_FW_ACTION_ALLOW Then
                    Firewall_IsAllowedProgram = True
                    Exit For
                End If
            End If
        End With
    Next

    Set pFwNetFwPolicy2 = Nothing
    Exit Function
ErrH:
    Debug.Print "ERROR: in " & "Firewall_IsAllowedProgram" & ". Err # " & Err.Number & " (" & Err.LastDllError & ") - " & Err.Description
End Function

[xiaoyao]

HOW TO LIST ALL Firewall EXE LIST?OR NAME LIST?
EXE1 NAME1
EXE2 NAME2

[Dragokas]

Private Sub Form_Load()
    'Lists all firewall rules, excepting disabled 
    Firewall_ListRules
End Sub

Public Sub Firewall_ListRules()

    On Error GoTo ErrH

    Dim pFwNetFwPolicy2 As New NetFwPolicy2
    Dim pFwRules As INetFwRules
    Dim pFwRule As NetFwRule

    Set pFwRules = pFwNetFwPolicy2.Rules

    For Each pFwRule In pFwRules
        If pFwRule.Enabled Then
            Debug.Print _
                IIf(pFwRule.Action = NET_FW_ACTION_ALLOW, "[Allow]", "[Block]") & " " & _
                IIf(pFwRule.Direction = NET_FW_RULE_DIR_IN, "[in] ", "[out]") & " " & _
                pFwRule.ApplicationName & " (" & pFwRule.Name & ")"
        End If
    Next

    Set pFwNetFwPolicy2 = Nothing
    Exit Sub
ErrH:
    Debug.Print "ERROR: in " & "Firewall_ListRules" & ". Err # " & Err.Number & " (" & Err.LastDllError & ") - " & Err.Description
End Sub

Be carefull, system rule names are localized.

[xiaoyao]

thank you very much

[cidtek]

I would like to list the actual port and protocol exceptions for my program that are allowed in the firewall.

Can this be done?

[Dragokas]

cidtek, use the code in the post #3.

And filter what you need by checking .ApplicationName property.

You can find other properties via IntelliSense or F2 of NetFwRule object.

Port and protocol are saved in properties:
- pFwRule.Protocol
- pFwRule.RemotePorts
- pFwRule.LocalPorts

[cidtek]

Thanks!