pcpp::IPv4Layer Class Reference

#include <IPv4Layer.h>

Inheritance diagram for pcpp::IPv4Layer:

Public Member Functions
	IPv4Layer (uint8_t *data, size_t dataLen, Layer *prevLayer, Packet *packet)
	IPv4Layer (uint8_t *data, size_t dataLen, Layer *prevLayer, Packet *packet, bool setTotalLenAsDataLen)
	IPv4Layer ()
	IPv4Layer (const IPv4Address &srcIP, const IPv4Address &dstIP)
	IPv4Layer (const IPv4Layer &other)
IPv4Layer &	operator= (const IPv4Layer &other)
iphdr *	getIPv4Header ()
IPv4Address	getSrcIpAddress ()
void	setSrcIpAddress (const IPv4Address &ipAddr)
IPv4Address	getDstIpAddress ()
void	setDstIpAddress (const IPv4Address &ipAddr)
bool	isFragment ()
bool	isFirstFragment ()
bool	isLastFragment ()
uint8_t	getFragmentFlags ()
uint16_t	getFragmentOffset ()
IPv4Option	getOption (IPv4OptionTypes option)
IPv4Option	getFirstOption ()
IPv4Option	getNextOption (IPv4Option &option)
size_t	getOptionCount ()
IPv4Option	addOption (const IPv4OptionBuilder &optionBuilder)
IPv4Option	addOptionAfter (const IPv4OptionBuilder &optionBuilder, IPv4OptionTypes prevOptionType=IPV4OPT_Unknown)
bool	removeOption (IPv4OptionTypes option)
bool	removeAllOptions ()
void	parseNextLayer ()
size_t	getHeaderLen ()
void	computeCalculateFields ()
std::string	toString ()
OsiModelLayer	getOsiModelLayer ()
Public Member Functions inherited from pcpp::Layer
virtual	~Layer ()
Layer *	getNextLayer ()
Layer *	getPrevLayer ()
ProtocolType	getProtocol ()
uint8_t *	getData ()
size_t	getDataLen ()
uint8_t *	getLayerPayload ()
size_t	getLayerPayloadSize ()
bool	isAllocatedToPacket ()
void	copyData (uint8_t *toArr)
uint8_t *	getDataPtr (size_t offset=0)

Detailed Description

Represents an IPv4 protocol layer

Constructor & Destructor Documentation

IPv4Layer() [1/5]

pcpp::IPv4Layer::IPv4Layer	(	uint8_t *	data,
		size_t	dataLen,
		Layer *	prevLayer,
		Packet *	packet
	)

A constructor that creates the layer from an existing packet raw data

Parameters

[in]	data	A pointer to the raw data (will be casted to iphdr)
[in]	dataLen	Size of the data in bytes
[in]	prevLayer	A pointer to the previous layer
[in]	packet	A pointer to the Packet instance where layer will be stored in

IPv4Layer() [2/5]

pcpp::IPv4Layer::IPv4Layer	(	uint8_t *	data,
		size_t	dataLen,
		Layer *	prevLayer,
		Packet *	packet,
		bool	setTotalLenAsDataLen
	)

A constructor that creates the layer from an existing packet raw data

Parameters

[in]	data	A pointer to the raw data (will be casted to iphdr)
[in]	dataLen	Size of the data in bytes
[in]	prevLayer	A pointer to the previous layer
[in]	packet	A pointer to the Packet instance where layer will be stored in
[in]	setTotalLenAsDataLen	When setting this value to "true" or when using the other c'tor, the layer data length is calculated from iphdr::totalLength field. When setting to "false" the data length is set as the value of dataLen parameter. Please notice that if iphdr::totalLength is equal to zero (which can happen in TCP Segmentation Offloading), this flag is ignored and the layer data length is calculated by the actual data captured on the wire

IPv4Layer() [3/5]

pcpp::IPv4Layer::IPv4Layer

(

)

A constructor that allocates a new IPv4 header with empty fields

IPv4Layer() [4/5]

pcpp::IPv4Layer::IPv4Layer	(	const IPv4Address &	srcIP,
		const IPv4Address &	dstIP
	)

A constructor that allocates a new IPv4 header with source and destination IPv4 addresses

Parameters

[in]	srcIP	Source IPv4 address
[in]	dstIP	Destination IPv4 address

IPv4Layer() [5/5]

pcpp::IPv4Layer::IPv4Layer

(

const IPv4Layer &

other

)

A copy constructor that copy the entire header from the other IPv4Layer (including IPv4 options)

Member Function Documentation

addOption()

IPv4Option pcpp::IPv4Layer::addOption

(

const IPv4OptionBuilder &

optionBuilder

)

Add a new IPv4 option at the end of the layer (after the last IPv4 option)

Parameters

[in]

optionBuilder

An IPv4OptionBuilder object that contains the IPv4 option data to be added

Returns

A IPv4Option object that contains the newly added IPv4 option data or logical NULL (IPv4Option::isNull() == true) if addition failed. In case of a failure a corresponding error message will be printed to log

addOptionAfter()

IPv4Option pcpp::IPv4Layer::addOptionAfter	(	const IPv4OptionBuilder &	optionBuilder,
		IPv4OptionTypes	prevOptionType = IPV4OPT_Unknown
	)

Add a new IPv4 option after an existing one

Parameters

[in]	optionBuilder	An IPv4OptionBuilder object that contains the requested IPv4 option data to be added
[in]	prevOptionType	The IPv4 option which the newly added option should come after. This is an optional parameter which gets a default value of IPV4OPT_Unknown if omitted, which means the new option will be added as the first option in the layer

Returns

A IPv4Option object containing the newly added IPv4 option data or logical NULL (IPv4Option::isNull() == true) if addition failed. In case of a failure a corresponding error message will be printed to log

computeCalculateFields()

void pcpp::IPv4Layer::computeCalculateFields ( )

virtual

Calculate the following fields:

• iphdr::ipVersion = 4;
• iphdr::totalLength = total packet length
• iphdr::headerChecksum = calculated
• iphdr::protocol = calculated if next layer is known: PACKETPP_IPPROTO_TCP for TCP, PACKETPP_IPPROTO_UDP for UDP, PACKETPP_IPPROTO_ICMP for ICMP

Implements pcpp::Layer.

getDstIpAddress()

IPv4Address pcpp::IPv4Layer::getDstIpAddress ( )

inline

Get the destination IP address in the form of IPv4Address

Returns

An IPv4Address containing the destination address

getFirstOption()

IPv4Option pcpp::IPv4Layer::getFirstOption

(

)

Returns

The first IPv4 option in the packet. If the current layer contains no options the returned value will contain a logical NULL (IPv4Option::isNull() == true)

getFragmentFlags()

uint8_t pcpp::IPv4Layer::getFragmentFlags

(

)

Returns

A bitmask containing the fragmentation flags (e.g IP_DONT_FRAGMENT or IP_MORE_FRAGMENTS)

getFragmentOffset()

uint16_t pcpp::IPv4Layer::getFragmentOffset

(

)

Returns

The fragment offset in case this packet is a fragment, 0 otherwise

getHeaderLen()

size_t pcpp::IPv4Layer::getHeaderLen ( )

inlinevirtual

Returns

Size of IPv4 header (including IPv4 options if exist)

Implements pcpp::Layer.

getIPv4Header()

iphdr* pcpp::IPv4Layer::getIPv4Header ( )

inline

Get a pointer to the IPv4 header. Notice this points directly to the data, so every change will change the actual packet data

Returns

A pointer to the iphdr

getNextOption()

IPv4Option pcpp::IPv4Layer::getNextOption

(

IPv4Option &

option

)

Get the IPv4 option that comes after a given option. If the given option was the last one, the returned value will contain a logical NULL (IPv4Option::isNull() == true)

Parameters

[in]

option

An IPv4 option object that exists in the current layer

Returns

A IPv4Option object that contains the IPv4 option data that comes next, or logical NULL if the given IPv4 option: (1) was the last one; or (2) contains a logical NULL; or (3) doesn't belong to this packet

getOption()

IPv4Option pcpp::IPv4Layer::getOption

(

IPv4OptionTypes

option

)

Get an IPv4 option by type.

Parameters

[in]

option

IPv4 option type

Returns

An IPv4Option object that contains the first option that matches this type, or logical NULL (IPv4Option::isNull() == true) if no such option found

getOptionCount()

size_t pcpp::IPv4Layer::getOptionCount

(

)

Returns

The number of IPv4 options in this layer

getOsiModelLayer()

OsiModelLayer pcpp::IPv4Layer::getOsiModelLayer ( )

inlinevirtual

Returns

The OSI Model layer this protocol belongs to

Implements pcpp::Layer.

getSrcIpAddress()

IPv4Address pcpp::IPv4Layer::getSrcIpAddress ( )

inline

Get the source IP address in the form of IPv4Address

Returns

An IPv4Address containing the source address

isFirstFragment()

bool pcpp::IPv4Layer::isFirstFragment

(

)

Returns

True if this packet is a fragment (in sense of IP fragmentation) and is the first fragment (which usually contains the L4 header). Return false otherwise (not a fragment or not the first fragment)

isFragment()

bool pcpp::IPv4Layer::isFragment

(

)

Returns

True if this packet is a fragment (in sense of IP fragmentation), false otherwise

isLastFragment()

bool pcpp::IPv4Layer::isLastFragment

(

)

Returns

True if this packet is a fragment (in sense of IP fragmentation) and is the last fragment. Return false otherwise (not a fragment or not the last fragment)

operator=()

IPv4Layer& pcpp::IPv4Layer::operator=

(

const IPv4Layer &

other

)

An assignment operator that first delete all data from current layer and then copy the entire header from the other IPv4Layer (including IPv4 options)

parseNextLayer()

void pcpp::IPv4Layer::parseNextLayer ( )

virtual

Currently identifies the following next layers: UdpLayer, TcpLayer. Otherwise sets PayloadLayer

Implements pcpp::Layer.

removeAllOptions()

bool pcpp::IPv4Layer::removeAllOptions

(

)

Remove all IPv4 options from the layer

Returns

True if options removed successfully or false if some error occurred (an appropriate error message will be printed to log)

removeOption()

bool pcpp::IPv4Layer::removeOption

(

IPv4OptionTypes

option

)

Remove an IPv4 option

Parameters

[in]

option

The option type to remove

Returns

True if option was removed successfully or false if option type wasn't found or failed to shorten the layer. If an option appears twice in the layer, its first instance will be removed

setDstIpAddress()

void pcpp::IPv4Layer::setDstIpAddress ( const IPv4Address &  ipAddr )

inline

Set the dest IP address

Parameters

[in]

ipAddr

The IP address to set

setSrcIpAddress()

void pcpp::IPv4Layer::setSrcIpAddress ( const IPv4Address &  ipAddr )

inline

Set the source IP address

Parameters

[in]

ipAddr

The IP address to set

toString()

std::string pcpp::IPv4Layer::toString ( )

virtual

Returns

A string representation of the layer most important data (should look like the layer description in Wireshark)

Implements pcpp::Layer.