pcpp::SdpLayer Class Reference

#include <SdpLayer.h>

Inheritance diagram for pcpp::SdpLayer:

Public Member Functions
	SdpLayer (uint8_t *data, size_t dataLen, Layer *prevLayer, Packet *packet)
	SdpLayer ()
	An empty c'tor which initialize an empty message with no fields.
	SdpLayer (const std::string &username, long sessionID, long sessionVersion, IPv4Address ipAddress, const std::string &sessionName, long startTime, long stopTime)
	SdpLayer (const SdpLayer &other)
SdpLayer &	operator= (const SdpLayer &other)
IPv4Address	getOwnerIPv4Address () const
uint16_t	getMediaPort (const std::string &mediaType) const
bool	addMediaDescription (const std::string &mediaType, uint16_t mediaPort, const std::string &mediaProtocol, const std::string &mediaFormat, const std::vector< std::string > &mediaAttributes)
OsiModelLayer	getOsiModelLayer () const override
std::string	toString () const override
Public Member Functions inherited from pcpp::TextBasedProtocolMessage
HeaderField *	getFieldByName (std::string fieldName, int index=0) const
HeaderField *	getFirstField () const
HeaderField *	getNextField (HeaderField *prevField) const
int	getFieldCount () const
virtual HeaderField *	addField (const std::string &fieldName, const std::string &fieldValue)
virtual HeaderField *	addField (const HeaderField &newField)
HeaderField *	addEndOfHeader ()
virtual HeaderField *	insertField (HeaderField *prevField, const std::string &fieldName, const std::string &fieldValue)
virtual HeaderField *	insertField (std::string prevFieldName, const std::string &fieldName, const std::string &fieldValue)
virtual HeaderField *	insertField (HeaderField *prevField, const HeaderField &newField)
bool	removeField (HeaderField *fieldToRemove)
bool	removeField (std::string fieldName, int index=0)
bool	isHeaderComplete () const
void	parseNextLayer () override
	Currently set only PayloadLayer for the rest of the data.
size_t	getHeaderLen () const override
void	computeCalculateFields () override
	Does nothing for this class.
Public Member Functions inherited from pcpp::Layer
	~Layer () override
Layer *	getNextLayer () const
Layer *	getPrevLayer () const
ProtocolType	getProtocol () const
bool	isMemberOfProtocolFamily (ProtocolTypeFamily protocolTypeFamily) 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 override

Detailed Description

Represents a SDP (Session Description Protocol) message. SDP is a text-based protocol described by a series of fields, one per line (lines are separated by CRLF). The form of each field is as follows:

[character]=[value]

Each character represents a certain type of field. All field type are represented as macros in SdpLayer.h file (for example: PCPP_SDP_ORIGINATOR_FIELD is a macro for the originator field (o=) ).
For more details about SDP structure please refer to its Wikipedia page: https://en.wikipedia.org/wiki/Session_Description_Protocol

Constructor & Destructor Documentation

SdpLayer() [1/3]

pcpp::SdpLayer::SdpLayer	(	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

SdpLayer() [2/3]

pcpp::SdpLayer::SdpLayer	(	const std::string &	username,
		long	sessionID,
		long	sessionVersion,
		IPv4Address	ipAddress,
		const std::string &	sessionName,
		long	startTime,
		long	stopTime
	)

A c'tor which initializes a message with the minimum required fields.
After this c'tor the message will look like this:

v=0
o=[username] [sessionID] [sessionVersion] IN IP4 [ipAddress]
s=[sessionName]
c=IN IP4 [ipAddress]
t=[startTime] [endTime]

Parameters

[in]	username	User's login on the originating host
[in]	sessionID	A globally unique identifier for the session
[in]	sessionVersion	A version number for this session description
[in]	ipAddress	The address of the machine from which the session is created
[in]	sessionName	A textual session name
[in]	startTime	The start time of the session
[in]	stopTime	The stop time of the session

SdpLayer() [3/3]

pcpp::SdpLayer::SdpLayer ( const SdpLayer &  other )

inline

A copy constructor for this layer. Inherits the base copy constructor and doesn't add anything else

Parameters

[in]

other

The instance to copy from

Member Function Documentation

addMediaDescription()

bool pcpp::SdpLayer::addMediaDescription	(	const std::string &	mediaType,
		uint16_t	mediaPort,
		const std::string &	mediaProtocol,
		const std::string &	mediaFormat,
		const std::vector< std::string > &	mediaAttributes
	)

Adds a 'media-description' field (m=) with all necessary data and attribute fields (a=) with data relevant for this media.
After this method is run the following block of fields will be added at the end of the message:

m=[mediaType] [mediaPort] [mediaProtocol] [mediaFormat]
a=[1st media attribute]
a=[2nd media attribute]
...

Parameters

[in]	mediaType	The media type, usually "audio", "video", "text" or "image"
[in]	mediaPort	The transport port to which the media stream is sent
[in]	mediaProtocol	The transport protocol, usually "udp", "RTP/AVP" or "RTP/SAVP"
[in]	mediaFormat	A space-separated list of media format description. For example: "8 96"
[in]	mediaAttributes	A vector of media attributes. Each string in this vector will be translated into a 'media-attribute' field (a=)

Returns

True if all fields were added properly or false if at least one field was failed to be added

getMediaPort()

uint16_t pcpp::SdpLayer::getMediaPort

(

const std::string &

mediaType

)

const

The 'media-description' field (m=) contains the transport port to which the media stream is sent. This port can be used to track the RTP data relevant for the call. This method extracts this port from the 'media-description' field and returns it. Since a SDP message can contain several 'media-description' fields, one for each media type (e.g audio, image, etc.), the user is required to provide the media type. A value of 0 will be returned in the following cases: (1) if 'media-description' field doesn't exist; (2) if provided media type was not found; (3) if 'media-description' field didn't contain a port

Parameters

[in]

mediaType

The media type to search in

Returns

The transport port to which the media stream is sent

getOsiModelLayer()

OsiModelLayer pcpp::SdpLayer::getOsiModelLayer ( ) const

inlineoverridevirtual

Returns

The OSI Model layer this protocol belongs to

Implements pcpp::Layer.

getOwnerIPv4Address()

IPv4Address pcpp::SdpLayer::getOwnerIPv4Address

(

)

const

The 'originator' field (o=) contains the IP address of the the machine from which the session is created. This IP address can be used to track the RTP data relevant for the call. This method extracts this IP address from the 'originator' field and returns it. A value of IPv4Address::Zero will be returned in the following cases: (1) if 'originator' field doesn't exist; (2) if it doesn't contain the IP address; (3) if it contains a non-IPv4 address

Returns

The IP address of the the machine from which the session is created

operator=()

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

inline

An assignment operator overload for this layer. Inherits the base assignment operator and doesn't add anything else

Parameters

[in]

other

The instance to copy from

toString()

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

overridevirtual

Returns

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

Implements pcpp::Layer.