rtppkt.h

ccrtp, ccrtp-1.5.0.tar.gz

	};

	/**
 	 * @struct RFC2833Payload
	 * @short a structure defining RFC2833 Telephony events.
	 *
	 * structure to define RFC2833 telephony events in RTP.  You can
	 * use this by recasing the pointer returned by getPayload().
	 */

public:
	struct RFC2833Payload
	{
#if __BYTE_ORDER == __BIG_ENDIAN
        	uint8 event : 8;
        	bool ebit : 1;
        	bool rbit : 1;
        	uint8 vol : 6;
        	uint16 duration : 16;
#else
        	uint8 event : 8;
        	uint8 vol : 6;
        	bool rbit : 1;
        	bool ebit : 1;
        	uint16 duration : 16;
#endif
	};

private:
	/**
	 * @struct RTPHeaderExt
	 *
	 * Fixed component of the variable-length header extension,
	 * appended to the fixed header, after the CSRC list, when X
	 * == 1.
	 **/
	struct RTPHeaderExt
	{
		uint16 undefined; ///< to be defined
		uint16 length;    ///< number of 32-bit words in the extension
	};
#ifdef	CCXX_PACKED
#pragma pack()
#endif

	/* definitions for access to most common 2833 fields... */

public:
	/**
	 * Fetch a raw 2833 packet.
	 *
	 * @return low level 2833 data structure.
	 */
	inline struct RFC2833Payload *getRaw2833Payload(void)
		{return (struct RFC2833Payload *)getPayload();};

	/**
	 * Fetch 2833 duration field.
	 *
	 * @return 2833 duration in native host machine byte order.
	 */
	inline uint16 get2833Duration(void)
		{return ntohs(getRaw2833Payload()->duration);};

	/**
	 * Set 2833 duration field.
	 *
	 * @param timestamp to use, native host machine byte order.
	 */
	inline void set2833Duration(uint16 timestamp)
		{getRaw2833Payload()->duration = htons(timestamp);};
};

/**
 * @class OutgoingRTPPkt
 * @short RTP packets being sent.
 *
 * This class is intented to construct packet objects just before they
 * are inserted into the sending queue, so that they are processed in
 * a understandable and format independent manner inside the stack.
 *
 * @author Federico Montesino Pouzols <[e-mail]>
 **/
class __EXPORT OutgoingRTPPkt : public RTPPacket
{
public:
	/**
	 * Construct a new packet to be sent, containing several
	 * contributing source identifiers, header extensions and
	 * payload.
         *
         * A new copy in memory (holding all this components
	 * along with the fixed header) is created. If the pointer
         * to the SRTP CryptoContext is not NULL and holds a CryptoContext
         * for the SSRC take the SSRC data into account when computing
         * the required memory buffer.
	 *
	 * @param csrcs array of countributing source 32-bit
	 *        identifiers, in host order.
	 * @param numcsrc number of CSRC identifiers in the array.
	 * @param hdrext whole header extension.
	 * @param hdrextlen size of whole header extension, in octets.
	 * @param data payload.
	 * @param datalen payload length, in octets.
	 * @param paddinglen pad packet to a multiple of paddinglen.
         * @param pcc Pointer to the SRTP CryptoContext, defaults to NULL
         * if not specified.
	 *
	 * @note For efficiency purposes, since this constructor is
	 * valid for all packets but is too complex for the common
	 * case, two simpler others are provided.
	 **/
	OutgoingRTPPkt(const uint32* const csrcs, uint16 numcsrc,
		       const unsigned char* const hdrext, uint32 hdrextlen,
		       const unsigned char* const data, size_t datalen,
                       uint8 paddinglen= 0, CryptoContext* pcc= NULL);

	/**
	 * Construct a new packet to be sent, containing several
	 * contributing source identifiers and payload.
         *
         * A new copy in
	 * memory (holding all this components along with the fixed
         * header) is created. If the pointer
         * to the SRTP CryptoContext is not NULL and holds a CryptoContext
         * for the SSRC take the SSRC data into account when computing
         * the required memory buffer.
	 *
	 * @param csrcs array of countributing source 32-bit
	 * identifiers, in host order.
	 * @param numcsrc number of CSRC identifiers in the array.
	 * @param data payload.
	 * @param datalen payload length, in octets.
	 * @param paddinglen pad packet to a multiple of paddinglen.
         * @param pcc Pointer to the SRTP CryptoContext, defaults to NULL
         * if not specified.
         **/
	OutgoingRTPPkt(const uint32* const csrcs, uint16 numcsrc,
		       const unsigned char* const data, size_t datalen,
                       uint8 paddinglen= 0, CryptoContext* pcc= NULL);

	/**
	 * Construct a new packet (fast variant, with no contributing
	 * sources and no header extension) to be sent.
         *
         * A new copy in
         * memory (holding the whole packet) is created. If the pointer
         * to the SRTP CryptoContext is not NULL and holds a CryptoContext
         * for the SSRC take the SSRC data into account when computing
         * the required memory buffer.
	 *
	 * @param data payload.
	 * @param datalen payload length, in octets.
	 * @param paddinglen pad packet to a multiple of paddinglen.
         * @param pcc Pointer to the SRTP CryptoContext, defaults to NULL
         * if not specified.
         **/
	OutgoingRTPPkt(const unsigned char* const data, size_t datalen,
                       uint8 paddinglen= 0, CryptoContext* pcc= NULL);

	~OutgoingRTPPkt()
	{ }

	/**
	 * @param pt Packet payload type.
	 **/
	inline void
	setPayloadType(PayloadType pt)
	{ getHeader()->payload = pt; };

	/**
         * Sets the sequence number in the header.
         *
	 * @param seq Packet sequence number, in host order.
	 **/
	inline void
	setSeqNum(uint16 seq)
	{
		cachedSeqNum = seq;
		getHeader()->sequence = htons(seq);
	}

	/**
	 * @param pts Packet timestamp, in host order.
	 **/
	inline void
	setTimestamp(uint32 pts)
	{
		cachedTimestamp = pts;
		getHeader()->timestamp = htonl(pts);
	}

	/**
	 * Set synchronization source numeric identifier.
	 *
	 * @param ssrc 32-bit Synchronization SouRCe numeric
	 * identifier, in host order.
	 **/
	inline void
	setSSRC(uint32 ssrc) const
	{ getHeader()->sources[0] = htonl(ssrc); }

	/**
	 * Set synchronization source numeric identifier. Special
	 * version to save endianness conversion.
	 *
	 * @param ssrc 32-bit Synchronization SouRCe numeric
	 * identifier, in network order.
	 **/
	inline void
	setSSRCNetwork(uint32 ssrc) const
	{ getHeader()->sources[0] = ssrc; }

	/**
	 * Specify the value of the marker bit. By default, the marker
	 * bit of outgoing packets is false/0. This method allows to
	 * explicity specify and change that value.
	 *
	 * @param mark value for the market bit.
	 */
	inline void
	setMarker(bool mark)
	{ getHeader()->marker = mark; }

        /**
         * Called packet is setup.
         *
         * This private method computes the SRTP data and stores it in the
         * packet. Then encrypt the payload data (ex padding).
         */
        void protect(uint32 ssrc, CryptoContext* pcc);

	/**
	 * Outgoing packets are equal if their sequence numbers match.
	 **/
	inline bool
	operator==(const OutgoingRTPPkt &p) const
	{ return ( this->getSeqNum() == p.getSeqNum() ); }

	/**
	 * Outgoing packets are not equal if their sequence numbers differ.
	 **/
	inline bool
	operator!=(const OutgoingRTPPkt &p) const
	{ return ( this->getSeqNum() != p.getSeqNum() ); }

        void enableZrtpChecksum() { zrtpChecksumLength = 2;}
        void computeZrtpChecksum();

private:
	/**
	 * Copy constructor from objects of its same kind, declared
	 * private to avoid its use.
	 **/
	OutgoingRTPPkt(const OutgoingRTPPkt &o);

	/**
	 * Assignment operator from objects of its same kind, declared
	 * private to avoid its use.
	 **/
	OutgoingRTPPkt&
	operator=(const OutgoingRTPPkt &o);

	/**
	 * Set the list of CSRC identifiers in an RTP packet,
	 * switching host to network order.
	 */
	void setCSRCArray(const uint32* const csrcs, uint16 numcsrc);

        int32 zrtpChecksumLength;

};

/**
 * @class IncomingRTPPkt
 *
 * @short RTP packets received from other participants.
 *
 * This class is intented to construct a packet object just after
 * every packet is received by the scheduled queue, so that they are
 * processed in an understandable and format independent manner inside
 * the stack.
 *
 * @author Federico Montesino Pouzols <[e-mail]>
 */
class __EXPORT IncomingRTPPkt : public RTPPacket
{
public:
	/**
	 * Build an RTP packet object from a data buffer. This
	 * constructor first performs a generic RTP data packet header
	 * check, whose result can be checked via isHeaderValid().
	 *
	 * @param block pointer to the buffer the whole packet is stored in.
	 * @param len length of the whole packet, expressed in octets.
	 *
	 * @note If check fails, the packet object is
	 * incomplete. checking isHeaderValid() is recommended before
	 * using a new RTPPacket object.
	 **/
	IncomingRTPPkt(const unsigned char* block, size_t len);

	~IncomingRTPPkt()
	{ }

	/**
	 * Get validity of this packet
	 * @return whether the header check performed at construction
	 *         time ended successfully.
	 **/
	inline bool
	isHeaderValid()
	{ return headerValid; }

	/**
	 * Get synchronization source numeric identifier.
	 *
	 * @return 32-bits Synchronization SouRCe numeric identifier,
	 * in host order.
	 **/
	inline uint32
	getSSRC() const
	{ return cachedSSRC; }

        /**
         * Unprotect a received packet.
         *
         * Perform SRTP processing on this packet.
         *
         * @param pcc Pointer to SRTP CryptoContext.
         * @return
         *     one if no errors, -1 if authentication failed, -2 if
         *     replay check failed
         */
        int32
        unprotect(CryptoContext* pcc);

	/**
	 * Two incoming packets are equal if they come from sources
	 * with the same SSRC and have the same sequence number.
	 **/
	inline bool
	operator==(const IncomingRTPPkt &p) const
	{ return ( (this->getSeqNum() == p.getSeqNum()) &&
		   (this->getSSRC() == p.getSSRC()) ); }

	/**
	 * Two incoming packets are not equal if they come from
	 * different sources or have different sequence numbers.
	 **/
	inline bool
	operator!=(const IncomingRTPPkt &p) const
	{ return !( *this == p ); }

        /**
         * Recompute and check ZRTP checksum
         *
         * If the <em>check</em> parameter is true then
         * this method recomputes the ZRTP checksum and compares it
         * with the checksum conatined in the packet. If the parameter
         * is set to false the method only adjusts the length of the
         * data.
         *
         * @param check
         *     if <code>true</code> recompute and check, otherwise
         *     adjust length of packet data only.
         * @return <code>true</code> if check is ok or only length was
         *     adjusted. If check fails returns <code>false</code>
         */
         bool
         checkZrtpChecksum(bool check);

private:
	/**
	 * Copy constructor from objects of its same kind, declared
	 * private to avoid its use.
	 **/
	IncomingRTPPkt(const IncomingRTPPkt &ip);

	/**
	 * Assignment operator from objects of its same kind, declared
	 * private to avoid its use.
	 */
	IncomingRTPPkt&
	operator=(const IncomingRTPPkt &ip);

	/// Header validity, checked at construction time.
	bool headerValid;
	/// SSRC 32-bit identifier in host order.
	uint32 cachedSSRC;
	// Masks for RTP header validation: types matching RTCP SR or
	// RR must be rejected to avoid accepting misaddressed RTCP
	// packets.
	static const uint16 RTP_INVALID_PT_MASK;
	static const uint16 RTP_INVALID_PT_VALUE;
};

/** @}*/ // rtppacket

#ifdef  CCXX_NAMESPACES
}
#endif

#endif  // ndef CCXX_RTP_RTPPKT_H_

/** EMACS **
 * Local variables:
 * mode: c++
 * c-basic-offset: 8
 * End:
 */