Add the README w/ the status of the project...

README.md

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+Testing FreeBSD ethernet Interfaces
+===================================
+
+This project is on pause for now, but contains work that I've done in
+late 2020 and early 2021 to try to create a test suite to make sure that
+FreeBSD ethernet drivers are programmed correctly, and have the correct
+behaviors.
+
+It is easy to assume that if an interface passes traffic that things are
+working properly, but there is much more to it than that.  As far as I
+can tell, there is no comprehensive test suite to validate that a driver
+works as expected, and that the features it claims to implement are
+properly implemented.
+
+A non-exhaustive list of features that could be listed as supported, but
+not working are jumbo frames (large MTU), hardware VLAN tagging, and
+checksum offload.  In the case of the last two, a driver can claim to
+support these, but if the underlying bits in ifnet structure are not set,
+nothing will happen.  Another example is that a driver could just always
+set that the checksum is valid, even when it is not.  In most cases, this
+won't be noticed, and with many protocols doing their own verification
+(ssh and TLS), it will just result in a dropped connection, but in other
+cases it will cause data corruption.
+
+As part of this project, two sets of patches were developed, one is the
+[kvm_ctf branch](https://www.funkthat.com/gitea/jmg/freebsd/src/branch/kvm_ctf)
+which implements the begining of an ABI agnostic method for transfering
+data from kernel to userland (and possibly back w/ some adaptations).
+It uses [Compact C Type Format](https://www.freebsd.org/cgi/man.cgi?query=ctf&apropos=0&sektion=0&manpath=FreeBSD+12.2-RELEASE+and+Ports&arch=default&format=html)
+to understand the layout of kernel data structures and the member sizes.
+The good thing about this is that it can, and will work against core
+dumps.  It would allow for minimal changes existing programs that use
+libkvm to get forwards compatibility.
+
+The other part is a custom DLT for fetching the mbuf csum flags on
+packets.  This covers both TX and RX, so can be used to verify that
+transmitted checksums are correctly updated AND verify that the
+correct flags are set on received packets.  The code for this is
+available on the [dlt_mbuf branch](https://www.funkthat.com/gitea/jmg/freebsd/src/branch/dlt_mbuf).
+The `bpf.py` file contains interface code for opening the BPF device
+and returning the necessary information.
+
+
+testinterfaces.sh
+=================
+
+This is the initial shell script version.  It uses a pair of FreeBSD
+jails w/ vnets, one with the interface under test, and another interface
+that is used to generate and receive the necessary test packets.  This
+has the advantage that it tests the full network stack, but due to
+various bugs, both in the FreeBSD IP stack (IPv6 addresses don't always
+get assigned properly), and possibly the driver (needing packets in the
+opposite direction to happen before they flow), it makes this a bit
+difficult to fully test.
+
+testeth.py
+==========
+
+This was started to allow direct inspection of the checksum flags.
+One advantage is that as packets can be generated and sent w/
+scapy/BPF, jails+vnets are not required, nor is the IP stack involved.
+The disadvantage is that it does not (currently) test the full network
+stack.
+
+Some progress has been made in replicating the features of the shell
+script, but this program is not as nearly complete, nor tested as the
+shell version.