nl.sidnlabs.pcap.decoder

Class IPDecoder

java.lang.Object

nl.sidnlabs.pcap.decoder.IPDecoder

public class IPDecoder
extends Object

Decode the IP header

Field Summary

Fields

Modifier and Type	Field and Description
static int	IP_FLAGS
static int	IP_FRAGMENT_OFFSET
static int	IP_PROTOCOL_VERSION_4
static int	IP_PROTOCOL_VERSION_6
static int	IP_TOTAL_LEN_OFFSET

Constructor Summary

Constructors

Constructor and Description
IPDecoder(Decoder tcpReader, Decoder udpReader, ICMPDecoder icmpDecoder)

Method Summary

Modifier and Type	Method and Description
void	clearCache(int ipFragmentTTL) Clear expired cache entries in order to avoid memory problems
Packet	createPacket(byte[] packetData, int ipStart)
Packet	decode(byte[] packetData, int ipStart, long packetTimestampSecs, long packetTimestampMicros)
com.google.common.collect.Multimap<Datagram,DatagramPayload>	getDatagrams()
byte[]	reassemble(Packet packet, byte[] packetData) Reassemble the IP packet is it is fragmented.
void	setDatagrams(com.google.common.collect.Multimap<Datagram,DatagramPayload> datagrams)

Methods inherited from class java.lang.Object

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

Field Detail

IP_PROTOCOL_VERSION_4

public static final int IP_PROTOCOL_VERSION_4

See Also:

Constant Field Values

IP_PROTOCOL_VERSION_6

public static final int IP_PROTOCOL_VERSION_6

See Also:

Constant Field Values

IP_TOTAL_LEN_OFFSET

public static final int IP_TOTAL_LEN_OFFSET

See Also:

Constant Field Values

IP_FLAGS

public static final int IP_FLAGS

See Also:

Constant Field Values

IP_FRAGMENT_OFFSET

public static final int IP_FRAGMENT_OFFSET

See Also:

Constant Field Values

Constructor Detail

IPDecoder

public IPDecoder(Decoder tcpReader,
                 Decoder udpReader,
                 ICMPDecoder icmpDecoder)

Method Detail

decode

public Packet decode(byte[] packetData,
                     int ipStart,
                     long packetTimestampSecs,
                     long packetTimestampMicros)

createPacket

public Packet createPacket(byte[] packetData,
                           int ipStart)

reassemble

public byte[] reassemble(Packet packet,
                         byte[] packetData)

Reassemble the IP packet is it is fragmented. If it is not fragmented then the packetData bytes are returned as result. If the packet is fragmented and this packet is the final fragment then all the bytes from the fragments are concatenated and returned. if fragmented and current fragment is not yet the final fragment then an empty byte array is returned. the

Parameters:

packet - the current packet

packetData - the payload of the current packet

Returns:

input, reassembled or no bytes

getDatagrams

public com.google.common.collect.Multimap<Datagram,DatagramPayload> getDatagrams()

setDatagrams

public void setDatagrams(com.google.common.collect.Multimap<Datagram,DatagramPayload> datagrams)

clearCache

public void clearCache(int ipFragmentTTL)

Clear expired cache entries in order to avoid memory problems

Parameters:

ipFragmentTTL - timeout for IP fragments