network/tcp_fastopen: add support for IPv6

Support for TCP Fast Open over IPv6 has been added to Linux 3.16.
Determine IP protocol from defined IP address. Also, make use of IPv6
server socket because it is backward compatible with IPv4 connections.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
3 files changed