net.clackrouter.component.extension
Class DNSHijacker

java.lang.Object
  net.clackrouter.component.base.ClackComponent
      net.clackrouter.component.extension.DNSHijacker

All Implemented Interfaces:

Alarm

public class DNSHijacker
extends ClackComponent

A fun little component that hijacks DNS requests being forwarded by the IP layer and sends back false replies.

Nested Class Summary

Nested classes/interfaces inherited from class net.clackrouter.component.base.ClackComponent

ClackComponent.Waiter

Field Summary

static java.lang.String	DEFAULT_FALSE_ADDRESS
static java.lang.String	DEFAULT_TARGET
static int	NUM_PORTS
static int	PORT_IN
static int	PORT_OUT

Fields inherited from class net.clackrouter.component.base.ClackComponent

componentCell, m_has_error, m_log, m_name, m_num_ports, m_packetcount_in, m_packetcount_out, m_ports, mListeners, mRouter, pendingError, SIGNAL_ERROR_LEN_MSEC, UNIQUE_COUNT, view

Constructor Summary

DNSHijacker(Router r, java.lang.String name)

DNSHijacker(Router r, java.lang.String name, java.lang.String target, java.lang.String falseAddress)

Method Summary

void	acceptPacket(VNSPacket packet, int port_number) Extract the packet and see if its UDP, and then DNS.
boolean	isModifying() Reports whether this component modifies packets passed through it This value is used by the static checking algorithm used to make sure port connections are valid.
void	setHijackPair(java.lang.String toHijack, java.net.InetAddress toReply) Sets a new address to hijack, and false IP
protected void	setupPorts(int numPorts) Allocates an array of ClackPort objects to be used by this component

Methods inherited from class net.clackrouter.component.base.ClackComponent

createCopy, createInputPullPort, createInputPushPort, createOutputPullPort, createOutputPushPort, error, fireListeners, getColor, getComponentCell, getHierarchicalView, getLog, getName, getNumPorts, getPacketCountIn, getPacketCountOut, getPendingError, getPort, getPropertiesView, getRouter, getSerializableProperties, getTime, getTypeName, getUniqueCount, getView, handlePullRequest, hasError, initializeProperties, isHierarchical, log, notifyAlarm, poll, registerListener, sendOutPort, setAlarm, setComponentCell, setName, setPendingError, setView, showErrorDialog, signalError, try_repaint, unregisterListener

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PORT_IN

public static int PORT_IN

PORT_OUT

public static int PORT_OUT

NUM_PORTS

public static int NUM_PORTS

DEFAULT_TARGET

public static java.lang.String DEFAULT_TARGET

DEFAULT_FALSE_ADDRESS

public static java.lang.String DEFAULT_FALSE_ADDRESS

Constructor Detail

DNSHijacker

public DNSHijacker(Router r,
                   java.lang.String name)

DNSHijacker

public DNSHijacker(Router r,
                   java.lang.String name,
                   java.lang.String target,
                   java.lang.String falseAddress)

Method Detail

setHijackPair

public void setHijackPair(java.lang.String toHijack,
                          java.net.InetAddress toReply)

Sets a new address to hijack, and false IP

Parameters:

toHijack - the domain name to hijack

toReply - the false IP address with which to reply

setupPorts

protected void setupPorts(int numPorts)

Description copied from class: ClackComponent

Allocates an array of ClackPort objects to be used by this component

Overrides:

setupPorts in class ClackComponent

Parameters:

numPorts - the number of ports to create

acceptPacket

public void acceptPacket(VNSPacket packet,
                         int port_number)

Extract the packet and see if its UDP, and then DNS. If it is, check if their is a query for the target DNS name we are trying to hijack. If there is, we create a DNS answer and add it to the original packet, modify the flags, flip the IP addresses and pass it on to be forwarded.

Overrides:

acceptPacket in class ClackComponent

Parameters:

packet - The pushed packet

port_number - The number of the port that this packet is arriving on

isModifying

public boolean isModifying()

Description copied from class: ClackComponent

Reports whether this component modifies packets passed through it This value is used by the static checking algorithm used to make sure port connections are valid. Sub-classes that do not modify packets should override this method

Overrides:

isModifying in class ClackComponent

Returns:

by default, we assume the component modifies packets