Speed-o-meter

in all honesty it is a mess having been produced in the sleep deprived haze of the hack day and needs both tidying up and commenting. I should get this done soon and uploaded to GitHub.

The API I am using to access the usage data from the Monowall firewall is intended for use on the web admin interface but can be used for anything. Unlike the rest of the interface that is written in PHP, this is written in C to make it more efficient.

The actual call is simple if you know about. Just type http://firewall.ip.address/stats.cgi?interface in to your browser replacing the interface with the WAN name from https://firewall.ip.address/interfaces_assign.php .

This will return 3 numbers. The first is the time of the request, second is the data downloaded, and the third is the data uploaded. You will need to use the last reading and the current one to calculate the actual throughput.

Currently the Arduino is connecting directly to the Monowall firewall on port 80 and requesting "/stats.cgi?vr0". This is an endpoint for the Web GUI API to monitor network usage in real time. vr0 is the name in the Interface on the WAN side.

In the HTTP headers we are sending "Authorization: Basic ****************************" where the starts are replaced with "username:password" base 64 encoded. This works well, but the password is as good as in the clear so is a bit of a security issue. Even if we have a secure connection between the firewall and the Speed-o-meter anyone administering the firewall will also be sending the password insecurely.

The solution to this is to use as HTTPS connection to the firewall, but the Arduino is not powerful enough to use HTTPS on its own. Normally I would proxy the request via a server that can connect via HTTPS, and this is what I started to do, but then I decided will look at creating a Monowall plugin. This plugin will either give access to the bandwidth data without authentication or encryption, or perhaps push the data to the Arduino. Watch this space.

I have uploaded a diagram of how the system works, and how it fits in to the network.

I took the opportunity to link the Speed-o-meter in to Maker Space's network on Saturday to create a short demonstration video. Enjoy.