Limit wifi access using .net application

Question

Currently following is the setup of my wifi connection.

Laptop 1 ------> Wifi Router <------ Laptop 2

There are about 5 laptops which connect to the wifi router to access internet. Network is password protected so anyone with a valid network key can connect and access internet.

I am planning to develop a local website which will be having a list of username and passwords. I will also remove the password of the wifi network so that anyone can connect.

If a connected system tries to access a web page in the internet then redirect them to a Login page (in the local website) and ask them to login. Once successfully logged i,n the mac id should be added to "Allow" list and monitoring starts. Internet should not be available for those who don't have a valid username and password.

I was thinking about developing the application to block/allow internet access though a vb.net/c# application.

I am okay with the website part. What I would like to know is

1. How I can block/allow internet access through the .net application.

2. Is it possible in .net or should I be going for an unmanaged code development?

3. If it is possible where is the best place to start? I have experience in winforms development but not much of network programming.

4. Will there be any change in my current wifi setup? May be a new webserver/proxy server which will host the website and the windows application?

Sorry about too many questions ;-)

Answer 1

There are two ways to go about this: You can buy an advanced wireless router that lets you hook up some sort of authentication system, or you can have a separate wired system between the wireless router and its upstream connection (with two network cards). At this point, you should be able to have software on that system to manage the traffic that goes across it (although I don't have direct knowledge of any particular software firewalls that you might be able to use for this)

Answer 2

DD-WRT (free firmware) has built in hotspot that already includes many of the features you are looking to build:

http://www.wi-fiplanet.com/tutorials/article.php/3730746

The DD-WRT software runs on the ubiquitous WRT54G router - which you may be using.

Total cost: $0-50 (depending on if you have a WRT54G already)