sip_transport.h

一个开源的sip源代码

     */
    pj_status_t (*send_msg)(pjsip_transport *transport, 
			    pjsip_tx_data *tdata,
			    const pj_sockaddr_t *rem_addr,
			    int addr_len,
			    void *token,
			    pjsip_transport_callback callback);

    /**
     * Instruct the transport to initiate graceful shutdown procedure.
     * After all objects release their reference to this transport,
     * the transport will be deleted.
     *
     * Note that application MUST use #pjsip_transport_shutdown() instead.
     *
     * @param transport	    The transport.
     *
     * @return		    PJ_SUCCESS on success.
     */
    pj_status_t (*do_shutdown)(pjsip_transport *transport);

    /**
     * Forcefully destroy this transport regardless whether there are
     * objects that currently use this transport. This function should only
     * be called by transport manager or other internal objects (such as the
     * transport itself) who know what they're doing. Application should use
     * #pjsip_transport_shutdown() instead.
     *
     * @param transport	    The transport.
     *
     * @return		    PJ_SUCCESS on success.
     */
    pj_status_t (*destroy)(pjsip_transport *transport);

    /*
     * Application may extend this structure..
     */
};


/**
 * Register a transport instance to the transport manager. This function
 * is normally called by the transport instance when it is created
 * by application.
 *
 * @param mgr		The transport manager.
 * @param tp		The new transport to be registered.
 *
 * @return		PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_transport_register( pjsip_tpmgr *mgr,
					       pjsip_transport *tp );


/**
 * Start graceful shutdown procedure for this transport. After graceful
 * shutdown has been initiated, no new reference can be obtained for
 * the transport. However, existing objects that currently uses the
 * transport may still use this transport to send and receive packets.
 *
 * After all objects release their reference to this transport,
 * the transport will be destroyed immediately.
 *
 * @param tp		    The transport.
 *
 * @return		    PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_transport_shutdown(pjsip_transport *tp);

/**
 * Destroy a transport when there is no object currently uses the transport.
 * This function is normally called internally by transport manager or the
 * transport itself. Application should use #pjsip_transport_shutdown()
 * instead.
 *
 * @param tp		The transport instance.
 *
 * @return		PJ_SUCCESS on success or the appropriate error code.
 *			Some of possible errors are PJSIP_EBUSY if the 
 *			transport's reference counter is not zero.
 */
PJ_DECL(pj_status_t) pjsip_transport_destroy( pjsip_transport *tp);

/**
 * Add reference counter to the specified transport. Any objects that wishes
 * to keep the reference of the transport MUST increment the transport's
 * reference counter to prevent it from being destroyed.
 *
 * @param tp		The transport instance.
 *
 * @return		PJ_SUCCESS on success or the appropriate error code.
 */
PJ_DECL(pj_status_t) pjsip_transport_add_ref( pjsip_transport *tp );

/**
 * Decrement reference counter of the specified transport. When an object no
 * longer want to keep the reference to the transport, it must decrement the
 * reference counter. When the reference counter of the transport reaches 
 * zero, the transport manager will start the idle timer to destroy the
 * transport if no objects acquire the reference counter during the idle
 * interval.
 *
 * @param tp		The transport instance.
 *
 * @return		PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_transport_dec_ref( pjsip_transport *tp );


/**
 * This function is called by transport instances to report an incoming 
 * packet to the transport manager. The transport manager then would try to
 * parse all SIP messages in the packet, and for each parsed SIP message, it
 * would report the message to the SIP endpoint (#pjsip_endpoint).
 *
 * @param mgr		The transport manager instance.
 * @param rdata		The receive data buffer containing the packet. The
 *			transport MUST fully initialize tp_info and pkt_info
 *			member of the rdata.
 *
 * @return		The number of bytes successfully processed from the
 *			packet. If the transport is datagram oriented, the
 *			value will be equal to the size of the packet. For
 *			stream oriented transport (e.g. TCP, TLS), the value
 *			returned may be less than the packet size, if 
 *			partial message is received. The transport then MUST
 *			keep the remainder part and report it again to
 *			this function once more data/packet is received.
 */
PJ_DECL(pj_ssize_t) pjsip_tpmgr_receive_packet(pjsip_tpmgr *mgr,
					       pjsip_rx_data *rdata);


/*****************************************************************************
 *
 * TRANSPORT FACTORY
 *
 *****************************************************************************/


/**
 * A transport factory is normally used for connection oriented transports
 * (such as TCP or TLS) to create instances of transports. It registers
 * a new transport type to the transport manager, and the transport manager
 * would ask the factory to create a transport instance when it received
 * command from application to send a SIP message using the specified
 * transport type.
 */
struct pjsip_tpfactory
{
    /** This list is managed by transport manager. */
    PJ_DECL_LIST_MEMBER(struct pjsip_tpfactory);

    char		    obj_name[PJ_MAX_OBJ_NAME];	/**< Name.	*/

    pj_pool_t		   *pool;	    /**< Owned memory pool.	*/
    pj_lock_t		   *lock;	    /**< Lock object.		*/

    pjsip_transport_type_e  type;	    /**< Transport type.	*/
    char		   *type_name;      /**< Type string name.	*/
    unsigned		    flag;	    /**< Transport flag.	*/

    pj_sockaddr		    local_addr;	    /**< Bound address.		*/
    pjsip_host_port	    addr_name;	    /**< Published name.	*/

    /**
     * Create new outbound connection.
     * Note that the factory is responsible for both creating the
     * transport and registering it to the transport manager.
     */
    pj_status_t (*create_transport)(pjsip_tpfactory *factory,
				    pjsip_tpmgr *mgr,
				    pjsip_endpoint *endpt,
				    const pj_sockaddr *rem_addr,
				    int addr_len,
				    pjsip_transport **transport);

    /**
     * Destroy the listener.
     */
    pj_status_t (*destroy)(pjsip_tpfactory *factory);

    /*
     * Application may extend this structure..
     */
};



/**
 * Register a transport factory.
 *
 * @param mgr		The transport manager.
 * @param tpf		Transport factory.
 *
 * @return		PJ_SUCCESS if listener was successfully created.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_register_tpfactory(pjsip_tpmgr *mgr,
						    pjsip_tpfactory *tpf);

/**
 * Unregister factory.
 *
 * @param mgr		The transport manager.
 * @param tpf		Transport factory.
 *
 * @return		PJ_SUCCESS is sucessfully unregistered.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_unregister_tpfactory(pjsip_tpmgr *mgr,
						      pjsip_tpfactory *tpf);


/*****************************************************************************
 *
 * TRANSPORT MANAGER
 *
 *****************************************************************************/
typedef void (*pjsip_rx_callback)(pjsip_endpoint*, pj_status_t, pjsip_rx_data *);
typedef pj_status_t (*pjsip_tx_callback)(pjsip_endpoint*, pjsip_tx_data*);
/**
 * Create a new transport manager.
 *
 * @param pool	    Pool.
 * @param endpt	    Endpoint instance.
 * @param rx_cb	    Callback to receive incoming message.
 * @param tx_cb	    Callback to be called before transport manager is sending
 *		    outgoing message.
 * @param p_mgr	    Pointer to receive the new transport manager.
 *
 * @return	    PJ_SUCCESS or the appropriate error code on error.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_create( pj_pool_t *pool,
					 pjsip_endpoint * endpt,
					 pjsip_rx_callback rx_cb,
					 pjsip_tx_callback tx_cb,
					 pjsip_tpmgr **p_mgr);


/**
 * Find out the appropriate local address info (IP address and port) to
 * advertise in Contact header based on the remote address to be 
 * contacted. The local address info would be the address name of the
 * transport or listener which will be used to send the request.
 *
 * In this implementation, it will only select the transport based on
 * the transport type in the request.
 *
 * @param tpmgr	    The transport manager.
 * @param pool	    Pool to allocate memory for the IP address.
 * @param type	    Destination address to contact.
 * @param sel	    Optional pointer to prefered transport, if any.
 * @param ip_addr   Pointer to receive the IP address.
 * @param port	    Pointer to receive the port number.
 *
 * @return	    PJ_SUCCESS, or the appropriate error code.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_find_local_addr( pjsip_tpmgr *tpmgr,
						  pj_pool_t *pool,
						  pjsip_transport_type_e type,
						  const pjsip_tpselector *sel,
						  pj_str_t *ip_addr,
						  int *port);

/**
 * Return number of transports currently registered to the transport
 * manager.
 *
 * @param mgr	    The transport manager.
 *
 * @return	    Number of transports.
 */
PJ_DECL(unsigned) pjsip_tpmgr_get_transport_count(pjsip_tpmgr *mgr);


/**
 * Destroy transport manager.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_destroy(pjsip_tpmgr *mgr);


/**
 * Dump transport info.
 */
PJ_DECL(void) pjsip_tpmgr_dump_transports(pjsip_tpmgr *mgr);


/*****************************************************************************
 *
 * PUBLIC API
 *
 *****************************************************************************/


/**
 * Find transport to be used to send message to remote destination. If no
 * suitable transport is found, a new one will be created.
 *
 * This is an internal function since normally application doesn't have access
 * to transport manager. Application should use pjsip_endpt_acquire_transport()
 * instead.
 *
 * @param mgr	    The transport manager instance.
 * @param type	    The type of transport to be acquired.
 * @param remote    The remote address to send message to.
 * @param addr_len  Length of the remote address.
 * @param sel	    Optional pointer to transport selector instance which is
 *		    used to find explicit transport, if required.
 * @param tp	    Pointer to receive the transport instance, if one is found.
 *
 * @return	    PJ_SUCCESS on success, or the appropriate error code.
 */
PJ_DECL(pj_status_t) pjsip_tpmgr_acquire_transport(pjsip_tpmgr *mgr,
						   pjsip_transport_type_e type,
						   const pj_sockaddr_t *remote,
						   int addr_len,
						   const pjsip_tpselector *sel,
						   pjsip_transport **tp);

typedef void (*pjsip_tp_send_callback)(void *token, pjsip_tx_data *tdata,
									   pj_ssize_t bytes_sent);
/**
 * Send a SIP message using the specified transport.
 */
PJ_DECL(pj_status_t) pjsip_transport_send( pjsip_transport *tr, 
					   pjsip_tx_data *tdata,
					   const pj_sockaddr_t *addr,
					   int addr_len,
					   void *token,
					   pjsip_tp_send_callback cb);


/**
 * @}
 */


PJ_END_DECL

#endif	/* __PJSIP_SIP_TRANSPORT_H__ */