com.hp.util.pkt

Class Packet

java.lang.Object

com.hp.util.pkt.Packet

public class Packet
extends Object

Packet (immutable) contains a list of protocol layers.

An onion metaphor is used to describe the layers of a packet. The layer index corresponds to the depth inside the packet. For example, if the following packet is constructed:

 Packet p = new Packet(eth, ip, udp, dhcp)
 

The layers are of the form:

• layers[0] = eth (outermost)
• layers[1] = ip
• layers[2] = udp
• layers[3] = dhcp (innermost)

In which case, a call to innermostId() would return ProtocolId.DHCP.

Author:

Frank Wood

Constructor Summary

Constructors

Constructor and Description
Packet(List<Protocol> layers) Constructor creates a packet of protocol layers.
Packet(Protocol... layers) Constructor creates a packet of protocol layers.

Method Summary

Methods

Modifier and Type	Method and Description
static long	computeProtocolMask(ProtocolId... protocols) Computes the mask of all protocol IDs.
Protocol	get(int i) Returns the protocol layer at the given index.
<P extends Protocol> P	get(ProtocolId id) Returns the first occurrence of the protocol (outer to inner) with the given protocol ID.
<P extends Protocol> P	get(ProtocolId id, int nth) Returns the Nth occurrence of the protocol (outer to inner) with the given protocol ID.
boolean	has(ProtocolId id) Returns true if the protocols corresponding to the given ID is contained in the packet.
boolean	hasAll(ProtocolId... ids) Returns true if all the protocols corresponding to the IDs are contained in the packet.
boolean	hasAny(ProtocolId... ids) Returns true if any of the protocols corresponding to the IDs are contained in the packet.
Protocol	innermost() Returns the innermost layer protocol (highest in the network stack).
Protocol	innermost(ProtocolId id) Returns the innermost layer protocol (highest in the network stack) that matches the provided protocol ID.
ProtocolId	innermostId() Returns the innermost layer protocol ID (highest in the the network stack).
List<ProtocolId>	protocolIds() Returns a list of protocol IDs from the outermost to innermost layer.
long	protocolMask() Returns the bit mask representing present protocol IDs.
int	size() Returns the number of protocol layers.
String	toDebugString() Returns the formatted debug string for the packet.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Packet

public Packet(Protocol... layers)

Constructor creates a packet of protocol layers.

Parameters:

layers - protocol layers

Packet

public Packet(List<Protocol> layers)

Constructor creates a packet of protocol layers.

Parameters:

layers - protocol layers

Method Detail

computeProtocolMask

public static long computeProtocolMask(ProtocolId... protocols)

Computes the mask of all protocol IDs.

Parameters:

protocols - collection of protocols

Returns:

bit mask of all protocol IDs

size

public int size()

Returns the number of protocol layers.

Returns:

the number of protocol layers

get

public Protocol get(int i)

Returns the protocol layer at the given index.

Parameters:

i - layer index

Returns:

the protocol layer at the given index or null

get

public <P extends Protocol> P get(ProtocolId id)

Returns the first occurrence of the protocol (outer to inner) with the given protocol ID.

Parameters:

id - protocol ID

Returns:

the protocol for the given ID or null

get

public <P extends Protocol> P get(ProtocolId id,
                         int nth)

Returns the Nth occurrence of the protocol (outer to inner) with the given protocol ID. For example if the layers are of the form:

• layers[0] = eth (outermost)
• layers[1] = ip
• layers[2] = gre
• layers[3] = eth
• layers[4] = ip
• layers[5] = udp
• layers[6] = dns

 get(ETHERNET, 0) // returns layers[0], same as get(ETHERNET)
 get(ETHERNET, 1) // returns layers[3]
 

Suppress warning is needed here because of the cast from Protocol to the generic type. It is safe because each concrete protocol must implement Protocol.id() to return its distinct ID.

Parameters:

id - protocol ID

nth - Nth protocol layer

Returns:

the protocol for the given ID or null

has

public boolean has(ProtocolId id)

Returns true if the protocols corresponding to the given ID is contained in the packet.

Parameters:

id - protocol ID

Returns:

true if the protocol is contained in the packet

hasAll

public boolean hasAll(ProtocolId... ids)

Returns true if all the protocols corresponding to the IDs are contained in the packet.

Parameters:

ids - protocol IDs

Returns:

true if all of the protocols are contained in the packet

hasAny

public boolean hasAny(ProtocolId... ids)

Returns true if any of the protocols corresponding to the IDs are contained in the packet.

Parameters:

ids - protocol IDs

Returns:

true if any of the protocols are contained in the packet

protocolIds

public List<ProtocolId> protocolIds()

Returns a list of protocol IDs from the outermost to innermost layer.

Returns:

list of protocol IDs

innermost

public Protocol innermost()

Returns the innermost layer protocol (highest in the network stack).

Returns:

the protocol layer or null

innermost

public Protocol innermost(ProtocolId id)

Returns the innermost layer protocol (highest in the network stack) that matches the provided protocol ID.

Parameters:

id - protocol ID

Returns:

the protocol layer or null

innermostId

public ProtocolId innermostId()

Returns the innermost layer protocol ID (highest in the the network stack).

Returns:

the protocol layer ID or UNKNOWN if there are no known protocols in the packet

protocolMask

public long protocolMask()

Returns the bit mask representing present protocol IDs.

Returns:

bit mask of protocol IDs

toString

public String toString()

Overrides:

toString in class Object

toDebugString

public String toDebugString()

Returns the formatted debug string for the packet.

Returns:

the formatted debug string representing this packet