Include the timestamp TCP option in keep alive packets as well.
Include the timestamp TCP option in keep alive packets as well.

According to RFC 7323 "once TSopt has been successfully negotiated,
... [it] MUST be sent in every non-<RST> segment for the duration
of the connection."  Which means that keep alives which are just
ACK packets must include that too.

Pointed out and tested by Lauri Tirkkonen <lotheac at iki ! fi>, thanks!
ok mpi

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars