#include <DnsLayer.h>

Inheritance diagram for pcpp::DnsLayer:

Public Member Functions
	DnsLayer (uint8_t data, size_t dataLen, Layer prevLayer, Packet *packet)

	DnsLayer ()

	DnsLayer (const DnsLayer &other)

DnsLayer &	operator= (const DnsLayer &other)

dnshdr *	getDnsHeader () const

DnsQuery *	getQuery (const std::string &name, bool exactMatch) const

DnsQuery *	getFirstQuery () const

DnsQuery *	getNextQuery (DnsQuery *query) const

size_t	getQueryCount () const

DnsQuery *	addQuery (const std::string &name, DnsType dnsType, DnsClass dnsClass)

DnsQuery *	addQuery (DnsQuery *const copyQuery)

bool	removeQuery (const std::string &queryNameToRemove, bool exactMatch)

bool	removeQuery (DnsQuery *queryToRemove)

DnsResource *	getAnswer (const std::string &name, bool exactMatch) const

DnsResource *	getFirstAnswer () const

DnsResource *	getNextAnswer (DnsResource *answer) const

size_t	getAnswerCount () const

DnsResource *	addAnswer (const std::string &name, DnsType dnsType, DnsClass dnsClass, uint32_t ttl, IDnsResourceData *data)

DnsResource *	addAnswer (DnsResource *const copyAnswer)

bool	removeAnswer (const std::string &answerNameToRemove, bool exactMatch)

bool	removeAnswer (DnsResource *answerToRemove)

DnsResource *	getAuthority (const std::string &name, bool exactMatch) const

DnsResource *	getFirstAuthority () const

DnsResource *	getNextAuthority (DnsResource *authority) const

size_t	getAuthorityCount () const

DnsResource *	addAuthority (const std::string &name, DnsType dnsType, DnsClass dnsClass, uint32_t ttl, IDnsResourceData *data)

DnsResource *	addAuthority (DnsResource *const copyAuthority)

bool	removeAuthority (const std::string &authorityNameToRemove, bool exactMatch)

bool	removeAuthority (DnsResource *authorityToRemove)

DnsResource *	getAdditionalRecord (const std::string &name, bool exactMatch) const

DnsResource *	getFirstAdditionalRecord () const

DnsResource *	getNextAdditionalRecord (DnsResource *additionalRecord) const

size_t	getAdditionalRecordCount () const

DnsResource *	addAdditionalRecord (const std::string &name, DnsType dnsType, DnsClass dnsClass, uint32_t ttl, IDnsResourceData *data)

DnsResource *	addAdditionalRecord (const std::string &name, DnsType dnsType, uint16_t customData1, uint32_t customData2, IDnsResourceData *data)

DnsResource *	addAdditionalRecord (DnsResource *const copyAdditionalRecord)

bool	removeAdditionalRecord (const std::string &additionalRecordNameToRemove, bool exactMatch)

bool	removeAdditionalRecord (DnsResource *additionalRecordToRemove)

void	parseNextLayer ()

size_t	getHeaderLen () const

virtual 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

Static Public Member Functions
static bool	isDnsPort (uint16_t port)

static bool	isDataValid (const uint8_t *data, size_t dataLen, bool dnsOverTcp=false)

Detailed Description

Represents the DNS protocol layer

Constructor & Destructor Documentation

◆ DnsLayer() [1/3]

pcpp::DnsLayer::DnsLayer	(	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
[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

◆ DnsLayer() [2/3]

pcpp::DnsLayer::DnsLayer ( )

A constructor that creates an empty DNS layer: all members of dnshdr are set to 0 and layer will contain no records

◆ DnsLayer() [3/3]

pcpp::DnsLayer::DnsLayer ( const DnsLayer & other )

A copy constructor for this layer

Parameters

[in] other The DNS layer to copy from

Member Function Documentation

◆ addAdditionalRecord() [1/3]

DnsResource* pcpp::DnsLayer::addAdditionalRecord	(	const std::string &	name,
		DnsType	dnsType,
		DnsClass	dnsClass,
		uint32_t	ttl,
		IDnsResourceData *	data
	)

Add a new DNS additional record to the layer

Parameters

[in]	name	The value that shall be set in the name field of the additional record
[in]	dnsType	The value that shall be set in the DNS type field of the additional record
[in]	dnsClass	The value that shall be set in the DNS class field of the additional record
[in]	ttl	The value that shall be set in the 'time-to-leave' field of the additional record
[in]	data	The additional record data to be set. The type of the data should match the type of the DNS record (for example: DNS record of type A should have data of type IPv4DnsResourceData. Please see DnsResource::setData() for more info on this

Returns: A pointer to the newly created DNS additional record or NULL if additional record could not be created (an appropriate error log message will be printed in this case)

◆ addAdditionalRecord() [2/3]

DnsResource* pcpp::DnsLayer::addAdditionalRecord	(	const std::string &	name,
		DnsType	dnsType,
		uint16_t	customData1,
		uint32_t	customData2,
		IDnsResourceData *	data
	)

Add a new DNS additional record to the layer that doesn't have DNS class and TTL. Instead these bytes may contains some arbitrary data. In the future I may add support for these kinds of additional data records. For now, these bytes are set as raw

Parameters

[in]	name	The value that shall be set in the name field of the additional record
[in]	dnsType	The value that shall be set in the DNS type field of the additional record
[in]	customData1	Two bytes of the arbitrary data that will be set in the offset usually used for the DNS class
[in]	customData2	Four bytes of the arbitrary data that will be set in the offset usually used for the TTL
[in]	data	The additional record data to be set. The type of the data should match the type of the DNS record. (for example: DNS record of type A should have data of type IPv4DnsResourceData. Please see DnsResource::setData() for more info on this

Returns: A pointer to the newly created DNS additional record or NULL if additional record could not be created (an appropriate error log message will be printed in this case)

◆ addAdditionalRecord() [3/3]

DnsResource* pcpp::DnsLayer::addAdditionalRecord ( DnsResource *const copyAdditionalRecord )

Add a new DNS additional record similar to an already existing DNS additional record. All additional record fields will be copied from the existing additional record

Parameters

[in] copyAdditionalRecord The record to create the new record from. copyAdditionalRecord won't be changed in any way

Returns: A pointer to the newly created DNS additional record or NULL if query could not be created (an appropriate error log message will be printed in this case)

◆ addAnswer() [1/2]

DnsResource* pcpp::DnsLayer::addAnswer	(	const std::string &	name,
		DnsType	dnsType,
		DnsClass	dnsClass,
		uint32_t	ttl,
		IDnsResourceData *	data
	)

Add a new DNS answer to the layer

Parameters

[in]	name	The value that shall be set in the name field of the answer
[in]	dnsType	The value that shall be set in the DNS type field of the answer
[in]	dnsClass	The value that shall be set in the DNS class field of the answer
[in]	ttl	The value that shall be set in the 'time-to-leave' field of the answer
[in]	data	The answer data to be set. The type of the data should match the type of the DNS record (for example: DNS record of type A should have data of type IPv4DnsResourceData. Please see DnsResource::setData() for more info on this

Returns: A pointer to the newly created DNS answer or NULL if answer could not be created (an appropriate error log message will be printed in this case)

◆ addAnswer() [2/2]

DnsResource* pcpp::DnsLayer::addAnswer ( DnsResource *const copyAnswer )

Add a new DNS answer similar to an already existing DNS answer. All answer fields will be copied from the existing answer

Parameters

[in] copyAnswer The record to create the new record from. copyAnswer won't be changed in any way

Returns: A pointer to the newly created DNS answer or NULL if query could not be created (an appropriate error log message will be printed in this case)

◆ addAuthority() [1/2]

DnsResource* pcpp::DnsLayer::addAuthority	(	const std::string &	name,
		DnsType	dnsType,
		DnsClass	dnsClass,
		uint32_t	ttl,
		IDnsResourceData *	data
	)

Add a new DNS authority to the layer

Parameters

[in]	name	The value that shall be set in the name field of the authority
[in]	dnsType	The value that shall be set in the DNS type field of the authority
[in]	dnsClass	The value that shall be set in the DNS class field of the authority
[in]	ttl	The value that shall be set in the 'time-to-leave' field of the authority
[in]	data	The authority data to be set. The type of the data should match the type of the DNS record (for example: DNS record of type A should have data of type IPv4DnsResourceData. Please see DnsResource::setData() for more info on this

Returns: A pointer to the newly created DNS authority or NULL if authority could not be created (an appropriate error log message will be printed in this case)

◆ addAuthority() [2/2]

DnsResource* pcpp::DnsLayer::addAuthority ( DnsResource *const copyAuthority )

Add a new DNS authority similar to an already existing DNS authority. All authority fields will be copied from the existing authority

Parameters

[in] copyAuthority The record to create the new record from. copyAuthority won't be changed in any way

Returns: A pointer to the newly created DNS authority or NULL if query could not be created (an appropriate error log message will be printed in this case)

◆ addQuery() [1/2]

DnsQuery* pcpp::DnsLayer::addQuery	(	const std::string &	name,
		DnsType	dnsType,
		DnsClass	dnsClass
	)

Add a new DNS query to the layer

Parameters

[in]	name	The value that shall be set in the name field of the query
[in]	dnsType	The value that shall be set in the DNS type field of the query
[in]	dnsClass	The value that shall be set in the DNS class field of the query

Returns: A pointer to the newly created DNS query or NULL if query could not be created (an appropriate error log message will be printed in this case)

◆ addQuery() [2/2]

DnsQuery* pcpp::DnsLayer::addQuery ( DnsQuery *const copyQuery )

Add a new DNS query similar to an already existing DNS query. All query fields will be copied from the existing query

Parameters

[in] copyQuery The record to create the new record from. copyQuery won't be changed in any way

Returns: A pointer to the newly created DNS query or NULL if query could not be created (an appropriate error log message will be printed in this case)

◆ computeCalculateFields()

virtual void pcpp::DnsLayer::computeCalculateFields ( )

inlinevirtual

Does nothing for this layer

Returns: No return value

Implements pcpp::Layer.

Reimplemented in pcpp::DnsOverTcpLayer.

◆ getAdditionalRecord()

DnsResource* pcpp::DnsLayer::getAdditionalRecord	(	const std::string &	name,
		bool	exactMatch
	)		const

Searches for a DNS additional record by its name field. Notice this method returns only an additional record which its name equals to the requested name. If several additional records match the requested name, the first one will be returned. If no additional records match the requested name, NULL will be returned

Parameters

[in]	name	The name of the additional record to search
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: The first matching DNS additional record or NULL if no additional records were found

◆ getAdditionalRecordCount()

size_t pcpp::DnsLayer::getAdditionalRecordCount ( ) const

Returns: The number of DNS additional records in the packet

◆ getAnswer()

DnsResource* pcpp::DnsLayer::getAnswer	(	const std::string &	name,
		bool	exactMatch
	)		const

Searches for a DNS answer by its name field. Notice this method returns only an answer which its name equals to the requested name. If several answers match the requested name, the first one will be returned. If no answers match the requested name, NULL will be returned

Parameters

[in]	name	The name of the answer to search
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: The first matching DNS answer or NULL if no answers were found

◆ getAnswerCount()

size_t pcpp::DnsLayer::getAnswerCount ( ) const

Returns: The number of DNS answers in the packet

◆ getAuthority()

DnsResource* pcpp::DnsLayer::getAuthority	(	const std::string &	name,
		bool	exactMatch
	)		const

Searches for a DNS authority by its name field. Notice this method returns only an authority which its name equals to the requested name. If several authorities match the requested name, the first one will be returned. If no authorities match the requested name, NULL will be returned

Parameters

[in]	name	The name of the authority to search
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: The first matching DNS authority or NULL if no authorities were found

◆ getAuthorityCount()

size_t pcpp::DnsLayer::getAuthorityCount ( ) const

Returns: The number of DNS authorities in the packet

◆ getDnsHeader()

dnshdr* pcpp::DnsLayer::getDnsHeader ( ) const

Get a pointer to the DNS header (as opposed to the DNS data which is the queries, answers, etc. Data can be retrieved through the other methods of this layer. Notice the return value points directly to the data, so every change will change the actual packet data

Returns: A pointer to the dnshdr

◆ getFirstAdditionalRecord()

DnsResource* pcpp::DnsLayer::getFirstAdditionalRecord ( ) const

Returns: The first DNS additional record in the packet or NULL if packet doesn't contain any additional records

◆ getFirstAnswer()

DnsResource* pcpp::DnsLayer::getFirstAnswer ( ) const

Returns: The first DNS answer in the packet or NULL if packet doesn't contain any answers

◆ getFirstAuthority()

DnsResource* pcpp::DnsLayer::getFirstAuthority ( ) const

Returns: The first DNS authority in the packet or NULL if packet doesn't contain any authorities

◆ getFirstQuery()

DnsQuery* pcpp::DnsLayer::getFirstQuery ( ) const

Returns: The first DNS query in the packet or NULL if packet doesn't contain any queries

◆ getHeaderLen()

size_t pcpp::DnsLayer::getHeaderLen ( ) const

inlinevirtual

Returns: The size of the DNS data in the packet including he DNS header and size of all queries, answers, authorities and additional records

Implements pcpp::Layer.

◆ getNextAdditionalRecord()

DnsResource* pcpp::DnsLayer::getNextAdditionalRecord ( DnsResource * additionalRecord ) const

Get the DNS additional record following a certain additional record

Parameters

[in] additionalRecord A pointer to a DNS additional record that exist in the packet

Returns: The DNS additional record following 'additionalRecord'. If 'additionalRecord' is NULL or 'additionalRecord' is the last additional record in the packet NULL will be returned

◆ getNextAnswer()

DnsResource* pcpp::DnsLayer::getNextAnswer ( DnsResource * answer ) const

Get the DNS answer following a certain answer

Parameters

[in] answer A pointer to a DNS answer that exist in the packet

Returns: The DNS answer following 'answer'. If 'answer' is NULL or 'answer' is the last answer in the packet NULL will be returned

◆ getNextAuthority()

DnsResource* pcpp::DnsLayer::getNextAuthority ( DnsResource * authority ) const

Get the DNS authority following a certain authority

Parameters

[in] authority A pointer to a DNS authority that exist in the packet

Returns: The DNS authority following 'authority'. If 'authority' is NULL or 'authority' is the last authority in the packet NULL will be returned

◆ getNextQuery()

DnsQuery* pcpp::DnsLayer::getNextQuery ( DnsQuery * query ) const

Get the DNS query following a certain query

Parameters

[in] query A pointer to a DNS query that exist in the packet

Returns: The DNS query following 'query'. If 'query' is NULL or 'query' is the last query in the packet NULL will be returned

◆ getOsiModelLayer()

OsiModelLayer pcpp::DnsLayer::getOsiModelLayer ( ) const

inlinevirtual

Returns: The OSI Model layer this protocol belongs to

Implements pcpp::Layer.

◆ getQuery()

DnsQuery* pcpp::DnsLayer::getQuery	(	const std::string &	name,
		bool	exactMatch
	)		const

Searches for a DNS query by its name field. Notice this method returns only a query which its name equals to the requested name. If several queries match the requested name, the first one will be returned. If no queries match the requested name, NULL will be returned

Parameters

[in]	name	The name of the query to search
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: The first matching DNS query or NULL if no queries were found

◆ getQueryCount()

size_t pcpp::DnsLayer::getQueryCount ( ) const

Returns: The number of DNS queries in the packet

◆ isDataValid()

bool pcpp::DnsLayer::isDataValid	(	const uint8_t *	data,
		size_t	dataLen,
		bool	dnsOverTcp = `false`
	)

inlinestatic

A static method that validates the input data

Parameters

[in]	data	The pointer to the beginning of a byte stream of a DNS packet
[in]	dataLen	The length of the byte stream
[in]	dnsOverTcp	Should be set to "true" if this is DNS is over TCP, otherwise set to "false" (which is also the default value)

Returns: True if the data is valid and can represent a DNS packet

◆ isDnsPort()

bool pcpp::DnsLayer::isDnsPort ( uint16_t port )

inlinestatic

A static method that checks whether the port is considered as DNS

Parameters

[in] port The port number to be checked

Returns: True if the port is associated with the DNS protocol

◆ operator=()

DnsLayer& pcpp::DnsLayer::operator= ( const DnsLayer & other )

An assignment operator for this layer

Parameters

[in] other The DNS layer to assign

Returns: A reference to the assignee

◆ parseNextLayer()

void pcpp::DnsLayer::parseNextLayer ( )

inlinevirtual

Does nothing for this layer (DnsLayer is always last)

Implements pcpp::Layer.

◆ removeAdditionalRecord() [1/2]

bool pcpp::DnsLayer::removeAdditionalRecord	(	const std::string &	additionalRecordNameToRemove,
		bool	exactMatch
	)

Remove an existing additional record by name. If several additional records matches the name, the first match will be removed

Parameters

[in]	additionalRecordNameToRemove	The name of the additional record to remove
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: True if additional record was found and successfully removed or false if additional record was not found or couldn't be removed

◆ removeAdditionalRecord() [2/2]

bool pcpp::DnsLayer::removeAdditionalRecord ( DnsResource * additionalRecordToRemove )

Remove an existing additional record

Parameters

[in] additionalRecordToRemove A pointer to the additional record to remove

Returns: True if additional record was found and successfully removed or false if additional record was not found or couldn't be removed

◆ removeAnswer() [1/2]

bool pcpp::DnsLayer::removeAnswer	(	const std::string &	answerNameToRemove,
		bool	exactMatch
	)

Remove an existing answer by name. If several answers matches the name, the first match will be removed

Parameters

[in]	answerNameToRemove	The name of the answer to remove
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: True if answer was found and successfully removed or false if answer was not found or couldn't be removed

◆ removeAnswer() [2/2]

bool pcpp::DnsLayer::removeAnswer ( DnsResource * answerToRemove )

Remove an existing answer

Parameters

[in] answerToRemove A pointer to the answer to remove

Returns: True if answer was found and successfully removed or false if answer was not found or couldn't be removed

◆ removeAuthority() [1/2]

bool pcpp::DnsLayer::removeAuthority	(	const std::string &	authorityNameToRemove,
		bool	exactMatch
	)

Remove an existing authority by name. If several authorities matches the name, the first match will be removed

Parameters

[in]	authorityNameToRemove	The name of the authority to remove
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: True if authority was found and successfully removed or false if authority was not found or couldn't be removed

◆ removeAuthority() [2/2]

bool pcpp::DnsLayer::removeAuthority ( DnsResource * authorityToRemove )

Remove an existing authority

Parameters

[in] authorityToRemove A pointer to the authority to remove

Returns: True if authority was found and successfully removed or false if authority was not found or couldn't be removed

◆ removeQuery() [1/2]

bool pcpp::DnsLayer::removeQuery	(	const std::string &	queryNameToRemove,
		bool	exactMatch
	)

Remove an existing query by name. If several queries matches the name, the first match will be removed

Parameters

[in]	queryNameToRemove	The name of the query to remove
[in]	exactMatch	Indicate whether to match the whole name or just a part of it

Returns: True if query was found and successfully removed or false if query was not found or couldn't be removed

◆ removeQuery() [2/2]

bool pcpp::DnsLayer::removeQuery ( DnsQuery * queryToRemove )

Remove an existing query

Parameters

[in] queryToRemove A pointer to the query to remove

Returns: True if query was found and successfully removed or false if query was not found or couldn't be removed

◆ toString()

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

virtual

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

Implements pcpp::Layer.

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ DnsLayer() [1/3]

◆ DnsLayer() [2/3]

◆ DnsLayer() [3/3]

Member Function Documentation

◆ addAdditionalRecord() [1/3]

◆ addAdditionalRecord() [2/3]

◆ addAdditionalRecord() [3/3]

◆ addAnswer() [1/2]

◆ addAnswer() [2/2]

◆ addAuthority() [1/2]

◆ addAuthority() [2/2]

◆ addQuery() [1/2]

◆ addQuery() [2/2]

◆ computeCalculateFields()

◆ getAdditionalRecord()

◆ getAdditionalRecordCount()

◆ getAnswer()

◆ getAnswerCount()

◆ getAuthority()

◆ getAuthorityCount()

◆ getDnsHeader()

◆ getFirstAdditionalRecord()

◆ getFirstAnswer()

◆ getFirstAuthority()

◆ getFirstQuery()

◆ getHeaderLen()

◆ getNextAdditionalRecord()

◆ getNextAnswer()

◆ getNextAuthority()

◆ getNextQuery()

◆ getOsiModelLayer()

◆ getQuery()

◆ getQueryCount()

◆ isDataValid()

◆ isDnsPort()

◆ operator=()

◆ parseNextLayer()

◆ removeAdditionalRecord() [1/2]

◆ removeAdditionalRecord() [2/2]

◆ removeAnswer() [1/2]

◆ removeAnswer() [2/2]

◆ removeAuthority() [1/2]

◆ removeAuthority() [2/2]

◆ removeQuery() [1/2]

◆ removeQuery() [2/2]

◆ toString()