No, it doesn't look like these products are what you're looking for. It sounds like you want a USB to Ethernet adaptor. I suspect you're looking for hardware that have an open source driver, rather then open hardware as mentioned that would include schematics and diagrams for studying and modifying.
I haven't personally found any one brand specifically, but when online shopping, keep an eye out for clues like "Linux 3.x" support.
For example, I purchased an off-the-shelf USB to Ethernet adaptor like this one from Amazon:
It says it has a AX88179 chipset, which is widely supported on a variety of operating systems.
0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet
This driver is in the Linux kernel. The source code can be found here: