References: golang.org/x/sys/unix.IP_USER

const golang.org/x/sys/unix.IP_USER_FLOW

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L4148: 	IP_USER_FLOW   = 0xd

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)