org.jnetpcap.protocol.network
Class Icmp

java.lang.Object
  org.jnetpcap.nio.JMemory
      org.jnetpcap.nio.JBuffer
          org.jnetpcap.packet.JHeader
              org.jnetpcap.packet.JHeaderMap<Icmp>
                  org.jnetpcap.protocol.network.Icmp

All Implemented Interfaces:

JCompoundHeader<Icmp>, JHeaderChecksum, JPayloadAccessor

@Header
public class Icmp
extends JHeaderMap<Icmp>
implements JHeaderChecksum

ICMP header definition.

Author:

Mark Bednarczyk, Sly Technologies, Inc.

Nested Class Summary

static class	Icmp.DestinationUnreachable ICMP Destination Unreachable header definition.
static class	Icmp.Echo ICMP Echo header (ping) baseclass definition.
static class	Icmp.EchoReply ICMP Echo Reply header definition.
static class	Icmp.EchoRequest ICMP Echo Request header definition.
static class	Icmp.IcmpCode A table of Icmp sub-codes per Icmp type.
static class	Icmp.IcmpType A table of IcmpTypes and their names.
static class	Icmp.ParamProblem ICMP Paramater Protoblem header definition.
static class	Icmp.Redirect ICMP Redirect header definition.
static class	Icmp.Reserved Base class for various ICMP Headers that contain a reserved field.
static class	Icmp.SourceQuench ICMP Source Quence header definition.

Nested classes/interfaces inherited from class org.jnetpcap.packet.JHeader

JHeader.State

Nested classes/interfaces inherited from class org.jnetpcap.nio.JMemory

JMemory.Type

Field Summary

static int

ID The Constant ID.

Fields inherited from class org.jnetpcap.packet.JHeaderMap

MAX_HEADERS, optionsBitmap, optionsLength, optionsOffsets, X_HEADERS

Fields inherited from class org.jnetpcap.packet.JHeader

annotatedHeader, BYTE, EMPTY_HEADER_ARRAY, isSubHeader, packet, state

Fields inherited from class org.jnetpcap.nio.JMemory

JNETPCAP_LIBRARY_NAME, MAX_DIRECT_MEMORY_DEFAULT, POINTER

Constructor Summary

Icmp()

Method Summary

int	calculateChecksum() Calculates a checksum using protocol specification for a header.
int	checksum() Retrieves the header's checksum.
java.lang.String	checksumDescription() Checksum description.
int	code() Code.
Icmp.IcmpCode	codeEnum() Code enum.
protected void	decodeHeader() Decode header.
static int	headerLength(JBuffer buffer, int offset) Header length.
boolean	isChecksumValid() Checks if the checksum is valid, for un-fragmented packets.
int	type() Type.
java.lang.String	typeDescription() Type description.
Icmp.IcmpType	typeEnum() Type enum.

Methods inherited from class org.jnetpcap.packet.JHeaderMap

getSubHeader, getSubHeaders, hasSubHeader, hasSubHeader, hasSubHeaders, setSubHeader, setSubHeaders

Methods inherited from class org.jnetpcap.packet.JHeader

decode, getAnnotatedHeader, getDescription, getFields, getGap, getGapLength, getGapOffset, getHeader, getHeaderLength, getHeaderOffset, getId, getIndex, getLength, getName, getNextHeaderId, getNextHeaderOffset, getNicname, getOffset, getPacket, getParent, getPayload, getPayloadLength, getPayloadOffset, getPostfix, getPostfixLength, getPostfixOffset, getPrefix, getPrefixLength, getPrefixOffset, getPreviousHeaderId, getPreviousHeaderOffset, getState, hasDescription, hasGap, hasNextHeader, hasPayload, hasPostfix, hasPrefix, hasPreviousHeader, isFragmented, isGapTruncated, isHeaderTruncated, isPayloadTruncated, isPostfixTruncated, isPrefixTruncated, peer, peer, peerPayloadTo, setPacket, sizeof, toString, transferPayloadTo, transferPayloadTo, transferPayloadTo, validateHeader

Methods inherited from class org.jnetpcap.nio.JBuffer

findUTF8String, getByte, getByteArray, getByteArray, getByteArray, getDouble, getFloat, getInt, getLong, getShort, getUByte, getUInt, getUShort, getUTF8Char, getUTF8String, getUTF8String, getUTF8String, getUTF8String, isReadonly, order, order, peer, peer, peer, peer, setByte, setByteArray, setByteBuffer, setDouble, setFloat, setInt, setLong, setShort, setShort0, setUByte, setUInt, setUShort, transferFrom, transferFrom, transferFrom, transferTo, transferTo, transferTo

Methods inherited from class org.jnetpcap.nio.JMemory

availableDirectMemory, check, cleanup, createReference, isInitialized, isJMemoryBasedOwner, isOwner, maxDirectMemory, peer, reservedDirectMemory, setSize, size, softDirectMemory, toDebugString, toHexdump, toHexdump, totalActiveAllocated, totalAllocateCalls, totalAllocated, totalAllocatedSegments0To255Bytes, totalAllocatedSegments256OrAbove, totalDeAllocateCalls, totalDeAllocated, transferFrom, transferFrom, transferFromDirect, transferOwnership, transferTo, transferTo, transferTo, transferTo, transferTo, transferTo0

Methods inherited from class java.lang.Object

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

Field Detail

ID

public static final int ID

The Constant ID.

See Also:

Constant Field Values

Constructor Detail

Icmp

public Icmp()

Method Detail

headerLength

@HeaderLength
public static int headerLength(JBuffer buffer,
                                            int offset)

Header length.

Parameters:

buffer - the buffer

offset - the offset

Returns:

the int

checksumDescription

@Dynamic(value=DESCRIPTION)
public java.lang.String checksumDescription()

Checksum description.

Returns:

the string

checksum

@Field(offset=16,
       length=16,
       format="%x")
public int checksum()

Retrieves the header's checksum.

Specified by:

checksum in interface JHeaderChecksum

Returns:

header's stored checksum

code

@Field(offset=8,
       length=8,
       format="%x")
public int code()

Code.

Returns:

the int

codeEnum

public Icmp.IcmpCode codeEnum()

Code enum.

Returns:

the icmp code

decodeHeader

protected void decodeHeader()

Decode header.

Overrides:

decodeHeader in class JHeader

See Also:

JHeader.decodeHeader()

type

@Field(offset=0,
       length=8,
       format="%x")
public int type()

Type.

Returns:

the int

typeDescription

@Dynamic(value=DESCRIPTION)
public java.lang.String typeDescription()

Type description.

Returns:

the string

typeEnum

public Icmp.IcmpType typeEnum()

Type enum.

Returns:

the icmp type

calculateChecksum

public int calculateChecksum()

Calculates a checksum using protocol specification for a header. Checksums for partial headers or fragmented packets (unless the protocol alows it) are not calculated.

Specified by:

calculateChecksum in interface JHeaderChecksum

Returns:

header's calculated checksum

isChecksumValid

public boolean isChecksumValid()

Checks if the checksum is valid, for un-fragmented packets. If a packet is fragmented, the checksum is not verified as data to is incomplete, but the method returns true none the less.

Specified by:

isChecksumValid in interface JHeaderChecksum

Returns:

true if checksum checks out or if this is a fragment, otherwise if the computed checksum does not match the stored checksum false is returned