pcpp::TcpLayer Class Reference

#include <TcpLayer.h>

Inheritance diagram for pcpp::TcpLayer:

Public Member Functions
	TcpLayer (uint8_t *data, size_t dataLen, Layer *prevLayer, Packet *packet)
	TcpLayer ()
	TcpLayer (uint16_t portSrc, uint16_t portDst)
	TcpLayer (const TcpLayer &other)
TcpLayer &	operator= (const TcpLayer &other)
tcphdr *	getTcpHeader () const
TcpOption	getTcpOption (TcpOptionType option) const
TcpOption	getFirstTcpOption () const
TcpOption	getNextTcpOption (TcpOption &tcpOption) const
size_t	getTcpOptionCount () const
TcpOption	addTcpOption (const TcpOptionBuilder &optionBuilder)
TcpOption	addTcpOptionAfter (const TcpOptionBuilder &optionBuilder, TcpOptionType prevOptionType=TCPOPT_Unknown)
bool	removeTcpOption (TcpOptionType optionType)
bool	removeAllTcpOptions ()
uint16_t	calculateChecksum (bool writeResultToPacket)
void	parseNextLayer ()
size_t	getHeaderLen () const
void	computeCalculateFields ()
std::string	toString () const
OsiModelLayer	getOsiModelLayer () const
Public Member Functions inherited from pcpp::Layer
virtual	~Layer ()
Layer *	getNextLayer () const
Layer *	getPrevLayer () const
ProtocolType	getProtocol () const
uint8_t *	getData () const
size_t	getDataLen () const
uint8_t *	getLayerPayload () const
size_t	getLayerPayloadSize () const
bool	isAllocatedToPacket () const
void	copyData (uint8_t *toArr) const
uint8_t *	getDataPtr (size_t offset=0) const

Detailed Description

Represents a TCP (Transmission Control Protocol) protocol layer

Constructor & Destructor Documentation

TcpLayer() [1/4]

pcpp::TcpLayer::TcpLayer	(	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 tcphdr)
[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

TcpLayer() [2/4]

pcpp::TcpLayer::TcpLayer

(

)

A constructor that allocates a new TCP header with zero TCP options

TcpLayer() [3/4]

pcpp::TcpLayer::TcpLayer	(	uint16_t	portSrc,
		uint16_t	portDst
	)

A constructor that allocates a new TCP header with source port and destination port and zero TCP options

Parameters

[in]	portSrc	Source port
[in]	portDst	Destination port

TcpLayer() [4/4]

pcpp::TcpLayer::TcpLayer

(

const TcpLayer &

other

)

A copy constructor that copy the entire header from the other TcpLayer (including TCP options)

Member Function Documentation

addTcpOption()

TcpOption pcpp::TcpLayer::addTcpOption

(

const TcpOptionBuilder &

optionBuilder

)

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

Parameters

[in]

optionBuilder

A TcpOptionBuilder object that contains the TCP option data to be added

Returns

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

addTcpOptionAfter()

TcpOption pcpp::TcpLayer::addTcpOptionAfter	(	const TcpOptionBuilder &	optionBuilder,
		TcpOptionType	prevOptionType = TCPOPT_Unknown
	)

Add a new TCP option after an existing one

Parameters

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

Returns

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

calculateChecksum()

uint16_t pcpp::TcpLayer::calculateChecksum

(

bool

writeResultToPacket

)

Calculate the checksum from header and data and possibly write the result to tcphdr::headerChecksum

Parameters

[in]

writeResultToPacket

If set to true then checksum result will be written to tcphdr::headerChecksum

Returns

The checksum result

computeCalculateFields()

void pcpp::TcpLayer::computeCalculateFields ( )

virtual

Calculate tcphdr::headerChecksum field

Implements pcpp::Layer.

getFirstTcpOption()

TcpOption pcpp::TcpLayer::getFirstTcpOption

(

)

const

Returns

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

getHeaderLen()

size_t pcpp::TcpLayer::getHeaderLen ( ) const

inlinevirtual

Returns

Size of tcphdr + all TCP options

Implements pcpp::Layer.

getNextTcpOption()

TcpOption pcpp::TcpLayer::getNextTcpOption

(

TcpOption &

tcpOption

)

const

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

Parameters

[in]

tcpOption

A TCP option object that exists in the current layer

Returns

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

getOsiModelLayer()

OsiModelLayer pcpp::TcpLayer::getOsiModelLayer ( ) const

inlinevirtual

Returns

The OSI Model layer this protocol belongs to

Implements pcpp::Layer.

getTcpHeader()

tcphdr* pcpp::TcpLayer::getTcpHeader ( ) const

inline

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

Returns

A pointer to the tcphdr

getTcpOption()

TcpOption pcpp::TcpLayer::getTcpOption

(

TcpOptionType

option

)

const

Get a TCP option by type

Parameters

[in]

option

TCP option type to retrieve

Returns

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

getTcpOptionCount()

size_t pcpp::TcpLayer::getTcpOptionCount

(

)

const

Returns

The number of TCP options in this layer

operator=()

TcpLayer& pcpp::TcpLayer::operator=

(

const TcpLayer &

other

)

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

parseNextLayer()

void pcpp::TcpLayer::parseNextLayer ( )

virtual

Currently identifies the following next layers: HttpRequestLayer, HttpResponseLayer. Otherwise sets PayloadLayer

Implements pcpp::Layer.

removeAllTcpOptions()

bool pcpp::TcpLayer::removeAllTcpOptions

(

)

Remove all TCP options in this layer

Returns

True if all TCP options were successfully removed or false if removal failed for some reason (a proper error will be written to log)

removeTcpOption()

bool pcpp::TcpLayer::removeTcpOption

(

TcpOptionType

optionType

)

Remove an existing TCP option from the layer. TCP option is found by type

Parameters

[in]

optionType

The TCP option type to remove

Returns

True if TCP option was removed or false if type wasn't found or if removal failed (in each case a proper error will be written to log)

toString()

std::string pcpp::TcpLayer::toString ( ) const

virtual

Returns

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

Implements pcpp::Layer.