net.sourceforge.jpcap.simulator
Class PacketCaptureSimulator

java.lang.Object
  net.sourceforge.jpcap.capture.PacketDispatcher
      net.sourceforge.jpcap.capture.PacketCaptureBase
          net.sourceforge.jpcap.simulator.PacketCaptureSimulator

All Implemented Interfaces:

PacketCaptureCapable, PacketDispatchCapable, net.sourceforge.jpcap.capture.PacketHandler

public class PacketCaptureSimulator

extends PacketCaptureBase

implements PacketCaptureCapable

This class has the same external interface as PacketCapture.

Instead of capturing and dispatching packets from a physical network device, however, this class generates fake packets. The type and frequency of the packets is set by policies configured in the simulator property file.

Instances of this class are used mostly by developers working on applications that utilize jpcap in environments where a real network device isn't available or when the type of packets arriving needs to be carefully controlled.

For more documentation on this class's methods, see PacketCaptureCapable; Javadoc is 'inherited' from this interface.

Field Summary

Fields inherited from class net.sourceforge.jpcap.capture.PacketCaptureBase

droppedCount, linkType, receivedCount

Fields inherited from interface net.sourceforge.jpcap.capture.PacketCaptureCapable

DEFAULT_SNAPLEN, DEFAULT_TIMEOUT

Constructor Summary

PacketCaptureSimulator()

Method Summary

void	capture(int count) The simulator's implementation of capture causes packets to be randomly generated.
void	close() Close the capture device.
java.lang.String	findDevice() Detect a network device suitable for packet capture.
int	getLinkLayerType() Fetch the link layer type for the specified device.
int	getNetmask(java.lang.String device) Fetch the network mask for the specified device.
int	getNetwork(java.lang.String device) Fetch the network number for the specified device.
int	getSnapshotLength() Get the snapshot length given that network device is open.
CaptureStatistics	getStatistics() Fetch statistics on captured packets.
java.lang.String[]	lookupDevices()
void	open(java.lang.String device, boolean promiscuous) Open a network device for data capture.
void	open(java.lang.String device, int snaplen, boolean promiscuous, int timeout) Open a network device for data capture.
void	openOffline(java.lang.String fileName) Open a tcpdump-formatted savefile.
void	setFilter(java.lang.String filterExpression, boolean optimize) Create, compile and activate a filter from a filter expression.

Methods inherited from class net.sourceforge.jpcap.capture.PacketCaptureBase

handlePacket

Methods inherited from class net.sourceforge.jpcap.capture.PacketDispatcher

addPacketListener, addRawPacketListener, dispatchPacket, dispatchRawPacket, removePacketListener, removeRawPacketListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sourceforge.jpcap.capture.PacketCaptureCapable

addPacketListener, addRawPacketListener, removePacketListener, removeRawPacketListener

Constructor Detail

PacketCaptureSimulator

public PacketCaptureSimulator()

Method Detail

open

public void open(java.lang.String device,
                 boolean promiscuous)
          throws CaptureDeviceOpenException

Description copied from interface: PacketCaptureCapable

Open a network device for data capture. Throws an exception if the device name specified is invalid. Uses default values for the capture timeout and snaplen.

Specified by:

open in interface PacketCaptureCapable

Parameters:

device - the name of the network device. Examples of valid network devices on linux are 'eth0' and 'ppp0'.

promiscuous - whether or not the device should be opened in promiscuous mode.

Throws:

CaptureDeviceOpenException

open

public void open(java.lang.String device,
                 int snaplen,
                 boolean promiscuous,
                 int timeout)

Description copied from interface: PacketCaptureCapable

Open a network device for data capture.

Specified by:

open in interface PacketCaptureCapable

Parameters:

device - the name of the network device. Examples of valid network devices on linux are 'eth0' and 'ppp0'.

snaplen - the 'snapshot' length. Defines the maximum number of bytes to save from each captured packet.

promiscuous - whether or not the device should be opened in promiscuous mode.

timeout - the packet capture timeout in milliseconds.

openOffline

public void openOffline(java.lang.String fileName)

Description copied from interface: PacketCaptureCapable

Open a tcpdump-formatted savefile.

Specified by:

openOffline in interface PacketCaptureCapable

Parameters:

fileName - the name of the savefile.

setFilter

public void setFilter(java.lang.String filterExpression,
                      boolean optimize)
               throws InvalidFilterException

Description copied from interface: PacketCaptureCapable

Create, compile and activate a filter from a filter expression.

Specified by:

setFilter in interface PacketCaptureCapable

Parameters:

filterExpression - the filter expression. For example, the expression "host techno" would filter only packets sent or arriving at the host named techno.

optimize - whether or not the resulting bpf code is optimized internally by libpcap.

Throws:

InvalidFilterException

capture

public void capture(int count)
             throws CapturePacketException

The simulator's implementation of capture causes packets to be randomly generated. The packet frequency and type are configurable.

Specified by:

capture in interface PacketCaptureCapable

Parameters:

count - the number of packets to capture. If count is negative, capture will block forever, unless an exception is thrown.

Throws:

CapturePacketException

getStatistics

public CaptureStatistics getStatistics()

Description copied from interface: PacketCaptureCapable

Fetch statistics on captured packets. This method should not be called unless capture() was previously called.

Specified by:

getStatistics in interface PacketCaptureCapable

Returns:

packet capture statistics.

close

public void close()

Description copied from interface: PacketCaptureCapable

Close the capture device.

Specified by:

close in interface PacketCaptureCapable

findDevice

public java.lang.String findDevice()
                            throws CaptureDeviceNotFoundException

Description copied from interface: PacketCaptureCapable

Detect a network device suitable for packet capture.

Specified by:

findDevice in interface PacketCaptureCapable

Returns:

a string describing the network device. if no device can be found, null is returned.

Throws:

CaptureDeviceNotFoundException

lookupDevices

public java.lang.String[] lookupDevices()
                                 throws CaptureDeviceLookupException

Throws:

CaptureDeviceLookupException

getNetwork

public int getNetwork(java.lang.String device)
               throws CaptureConfigurationException

Description copied from interface: PacketCaptureCapable

Fetch the network number for the specified device.

Specified by:

getNetwork in interface PacketCaptureCapable

Parameters:

device - the name of the network device.

Returns:

the network address

Throws:

CaptureConfigurationException

getNetmask

public int getNetmask(java.lang.String device)
               throws CaptureConfigurationException

Description copied from interface: PacketCaptureCapable

Fetch the network mask for the specified device.

Specified by:

getNetmask in interface PacketCaptureCapable

Parameters:

device - the name of the network device.

Returns:

the netmask address

Throws:

CaptureConfigurationException

getLinkLayerType

public int getLinkLayerType()
                     throws CaptureConfigurationException

Description copied from interface: PacketCaptureCapable

Fetch the link layer type for the specified device.

Specified by:

getLinkLayerType in interface PacketCaptureCapable

Returns:

the link layer type code.

Throws:

CaptureConfigurationException

getSnapshotLength

public int getSnapshotLength()

Description copied from interface: PacketCaptureCapable

Get the snapshot length given that network device is open.

Specified by:

getSnapshotLength in interface PacketCaptureCapable

Returns:

the packet snapshot length.