Somebody had to do it. Maximilian Stadlmeier did:

User space network drivers on Linux are often used in production environments to improve the performance of network-heavy applications. However, their inner workings are not clear to most
programmers who use them. ixy aims to change this by providing a small educational user space network driver, which is gives a good overview of how these drivers work, using only 1000 lines of C code.
While the language C is a good common denominator, which many developers are familiar with, its syntax is often much more dicult to read than that of more modern languages and makes the driver seem more complex than it actually is.

For this thesis I created a C# version of ixy, named ixy.cs, which utilizes the more modern syntax and additional safety of the C# programming language in order to make user space network driver development even more accessible. The viability of C# for driver programming will be analyzed and its advantages and disadvantages will be discussed.

The actual implementation (with other programming languages as well) can be found here.

Apparently it’s not as slow as you might think: