io.pkts.packet.impl

Class AbstractPacket

java.lang.Object

io.pkts.packet.impl.AbstractPacket

All Implemented Interfaces:

Packet, Cloneable

Direct Known Subclasses:

AbstractApplicationPacket, IPv4PacketImpl, IPv6PacketImpl, MACPacketImpl, PCapPacketImpl, RtcpPacketImpl, RtpPacketImpl, SDPPacketImpl, SipPacketImpl, TransportPacketImpl

public abstract class AbstractPacket
extends Object
implements Packet

ALL packets within pkts.io must implement this AbstractPacket.

Author:

jonas@jonasborjesson.com

Constructor Summary

Constructors

Constructor and Description
AbstractPacket(Protocol p, Packet parent, Buffer payload)

Method Summary

Modifier and Type	Method and Description
Packet	checkParent(Protocol p)
abstract Packet	clone()
String	getName() Get the name of the packet.
Packet	getPacket(Protocol p) Find the packet for protocol p.
Packet	getParentPacket() Almost all packets have a parent, which is the encapsulating protocol.
Buffer	getPayload() Get the payload of the frame.
Protocol	getProtocol() Get the protocol of this frame.
boolean	hasProtocol(Protocol p) Check whether this packet contains a particular protocol.
void	verify() Calling this method will force the packet to completely parse its data and check so that all the information conforms to whatever rules this packet needs to follow.
void	write(OutputStream out) The write strategy is fairly simple.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.pkts.packet.Packet

getArrivalTime, getNextPacket, write

Constructor Detail

AbstractPacket

public AbstractPacket(Protocol p,
                      Packet parent,
                      Buffer payload)

Parameters:

p - the protocol that this Packet is representing.

parent - all Packet have a parent, this is it.

payload - the payload of the packet, which may be null. Note, this is the actual payload of this packet. For an IPPacket that would typically be TransportPacket (such as udp or tcp). For a UDPPacket, the payload could really be anything, such as a SipPacket.

Method Detail

verify

public void verify()

Description copied from interface: Packet

Calling this method will force the packet to completely parse its data and check so that all the information conforms to whatever rules this packet needs to follow. E.g., if this happens to be a SIP packet, then it will check if it has the mandatory headers etc. Some simpler packets, such as the IPPacket, hardly does anything in this method but more complex protocols such as SIP (once again), HTTP etc can spend quite some time verifying everything, which is why you don't want to do it unless you really have to. In general, yajpcap has the philosophy of "assume that everything is ok until things blow up and then deal with it"

Specified by:

verify in interface Packet

write

public final void write(OutputStream out)
                 throws IOException

The write strategy is fairly simple. If we have a "nextPacket" it means that we have been asked to frame our payload which also means that that payload may have changed and therefore ask the nextPacket to write itself back out to the stream. If there is no nextPacket we can just take the raw payload and write it out as is since it cannot have changed since we framed this packet.

Specified by:

write in interface Packet

Throws:

IOException

clone

public abstract Packet clone()

Specified by:

clone in interface Packet

Overrides:

clone in class Object

getParentPacket

public Packet getParentPacket()

Description copied from interface: Packet

Almost all packets have a parent, which is the encapsulating protocol. E.g., the parent of a SipPacket is typically a TransportPacket such as UDPPacket or a TCPPacket. The parent of a TransportPacket is usually a IPPacket and so on.

Specified by:

getParentPacket in interface Packet

Returns:

hasProtocol

public boolean hasProtocol(Protocol p)
                    throws IOException

Description copied from interface: Packet

Check whether this packet contains a particular protocol. This will cause the packet to examine all the containing packets to check whether they are indeed the protocol the user asked for.

Specified by:

hasProtocol in interface Packet

Returns:

Throws:

IOException - in case something goes wrong when framing the rest of the protocol stack

getProtocol

public Protocol getProtocol()

Description copied from interface: Packet

Get the protocol of this frame.

Specified by:

getProtocol in interface Packet

Returns:

getPacket

public Packet getPacket(Protocol p)
                 throws IOException,
                        PacketParseException

Description copied from interface: Packet

Find the packet for protocol p.

Specified by:

getPacket in interface Packet

Returns:

the packets that encapsulates the protocol or null if this protocol doesn't exist

Throws:

IOException - in case something goes wrong when framing the rest of the protocol stack

PacketParseException - if the next packet can't be parsed by the framer

checkParent

public Packet checkParent(Protocol p)

getName

public String getName()

Description copied from interface: Packet

Get the name of the packet. Wireshark will give you a short description of all the known protocols within its "super" packet. E.g., if you "click" on the Pcap Frame it will have a field called "protocols in frame" and will display something like "eth:ip:udp:sip:sdp", this function will return a short name like that.

Specified by:

getName in interface Packet

Returns:

getPayload

public Buffer getPayload()

Description copied from interface: Packet

Get the payload of the frame. If null, then this frame doesn't have any payload

Specified by:

getPayload in interface Packet

Returns: