pkg/netutil/isolate_linux.go
func DropPort(port int) error {
	cmdStr := fmt.Sprintf("sudo iptables -A OUTPUT -p tcp --destination-port %d -j DROP", port)
	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
		return err
	}
	cmdStr = fmt.Sprintf("sudo iptables -A INPUT -p tcp --destination-port %d -j DROP", port)
	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
	return err
}
func DropPort(port int) error {
	cmdStr := fmt.Sprintf("sudo iptables -A OUTPUT -p tcp --destination-port %d -j DROP", port)
	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
		return err
	}
	cmdStr = fmt.Sprintf("sudo iptables -A INPUT -p tcp --destination-port %d -j DROP", port)
	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
	return err
}
// DropPort drops all tcp packets that are received from the given port and sent to the given port.