code: func stringToProtocol(protocol string) uint16 {
  	switch strings.ToLower(protocol) {
  	case "tcp":
  		return uint16(syscall.IPPROTO_TCP)
  	case "udp":
  		return uint16(syscall.IPPROTO_UDP)
  	case "sctp":
  		return uint16(syscall.IPPROTO_SCTP)
  	}
  	return uint16(0)
  }
docs: // stringToProtocolType returns the protocol type for the given name