Common code in netebpfext.sys should be refactor for reusability

[Alan-Jowett]

The netebpfext.sys driver contains a lot of common code that makes writing eBPF extension drivers simpler.

This code should be refactored and be made available to other driver developers.

Possible options:

1. Export Driver
2. Static library
3. A git submodule

An export driver is probably the most useful as it would allow a single version of the code to be patched once if there was a bug.

[Alan-Jowett]

List all files in https://github.com/microsoft/ntosebpfext/tree/main/ntosebpfext

Total LOC - 3371
Code that is specific to this extension - 435

$ pwd
/e/ntosebpfext/ntosebpfext
$ git ls-files | xargs cat | wc -l
3371
$ cat ntos_ebpf_ext_process.c  | wc -l
413
$ cat ntos_ebpf_ext_process.h  | wc -l
22

87% of this driver code is boiler plate.

[mtfriesen]

FWIW, the XDP boilerplate that seems trivially submodule-able is in https://github.com/microsoft/xdp-for-windows/blob/main/src/xdp/ebpfextension.c. This was derived from the netebpfext codebase, but is subtly different.