MVC - Block IP Address Using Action Filter

Article Overview

Background

Implementation of Action Filter (OnActionExecuting)
Inject Filter at a different level
Skip Filter at a different level

Pre-requisites
How to block an IP address using Action Filter

Implementation of Action Filter (OnActionExecuting)
Inject Filter at a different level
Skip Filter at a different level

Complete example

Implementation of Action Filter (OnActionExecuting)
Inject Filter at a different level
Skip Filter at a different level
Output

Summary

Background

There was a requirement for an MVC web application where I had to allow application access only to specific IP addresses. In other words, I had to block IP addresses that weren't valid. I have gone through various sites to implement Filters, Action Filters, Get IP address, etc. Hence, I had to customize searched solutions in an effective and easy way.

This article mainly focuses on three key things:

Implementation of Action Filter (OnActionExecuting)
Inject Filter at a different level
Skip Filter at a different level

Here, I have kept all the implementation details along with a complete example.

Prerequisites

You MUST have basic knowledge of ASP .NET MVC, Filters, and Action Filter.

How to block an IP address using Action Filter

There are mainly three key steps to implement this:

Implementation of Action Filter (OnActionExecuting)
Inject Filter at a different level
Skip Filter at a different level

Now, let us see in detail.

Implementation of Action Filter (OnActionExecuting)

First, add a folder “Attribute” into MVC Web Application.

Second, add a class “LogAttribute” into “Attribute” folder.

Third, inherit “ActionFilterAttribute” to “LogAttribute” class.

public class LogAttribute : ActionFilterAttribute

ActionFilterAttribute is an abstract class having four virtual methods (OnActionExecuted, OnActionExecuting, OnResultExecuted, and OnResultExecuting) which we can override in “LogAttribute” class.

Fourth, override “OnActionExecuting” method in “LogAttribute” class.

public override void OnActionExecuting(ActionExecutingContext filterContext)

Inject Filter at a different level

There are mainly three levels where you can inject a filter: Action, Controller, and Globally.

Action: When a filter is injected with a set of actions, only those actions will be injected

[Log]
public ActionResult About()
{

Controller: When a filter is injected into a controller class, all its actions are also injected

[Log]
public class HomeController : Controller
{

Globally: By registering filters globally will be triggered by all the actions performed in the application

public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute());
filters.Add(new LogAttribute());
}

Skip Filter at a different level

There are mainly two levels where you can skip an injected filter.

Globally filters can be skipped at Controller or Action level.

Filter injected at Controller can be skipped at the Action level.

First, create another filter SkipAttribute and inherit System.Attribute.

public class SkipAttribute : System.Attribute

Second, inject above filter at the action.

[Skip]
public ActionResult Error()
{

Third, modify LogAttribute to ignore for SkipFilter.

bool skipFilter = filterContext.ActionDescriptor.ControllerDescriptor.IsDefined(typeof(SkipAttribute), true) || filterContext.ActionDescriptor.IsDefined(typeof(SkipAttribute), true);

Here, I have given high-level steps for our requirement. Now, let us see the complete example which will give you more clarity about these steps.

Complete example

For the complete example, I have prepared and uploaded a file which contains all the code.

Implementation of Action Filter (OnActionExecuting)
Inject Filter at different level
Skip Filter at different level
Output

Implementation of Action Filter (OnActionExecuting)

Inject Filter at a different level

Skip Filter at a different level

Output

First, valid IP.

Second, invalid IP.

Third, Log tracking file.

Summary

Now, I believe you will be able to implement Action Filter (OnActionExecuting) along with injecting at different levels as well as skipping at a specific level.

10 Comments

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Dhruvik Sathvara7y ago
Very useful article.. thanks for sharing...
- Pankajkumar Patel7y ago
  Thanks Dhruvik Sathvara for the feedback
Chittaranjan Swain7y ago
Nice article, thanks for sharing.
- Pankajkumar Patel7y ago
  Thanks Chittaranjan Swain for the feedback
Arvind Patel7y ago
Nice article...!!
- Pankajkumar Patel7y ago
  Thanks Arvind Patel for the feedback
Arvind Kataria7y ago
Good Explanation ... !!!
- Pankajkumar Patel7y ago
  Thanks Arvind Kataria for the feedback
Amit Mohanty7y ago
Nice article
- Pankajkumar Patel7y ago
  Thanks Amit Mohanty for the feedback