Initial support for TCP Authentication Option

[cdleonard]

This works with Linux patches from here: https://github.com/cdleonard/linux/commits/tcp_authopt

Upstream RFC: https://www.notion.so/TCP-AuthOpt-b4c58f69d3eb44e48f7acd4997ec1e7e#f79df14201ee4619adaaa0524458c049

ABI is unstable so this shouldn't be merged but feedback is welcome.

Signed-off-by: Leonard Crestez [email protected]

[xiaopeng163]

Hi @cdleonard that is a good one, thanks for your work.