Transaction
[Transaction Layer]

Transaction instance for all types of SIP transactions.The pjsip_transaction describes SIP transaction, and is used for both INVITE and non-INVITE, UAC or UAS. Application must register the transaction layer module with pjsip_tsx_layer_init_module() before performing any stateful operations.

Data Structures
struct	pjsip_transaction
Enumerations
enum	pjsip_tsx_state_e { PJSIP_TSX_STATE_NULL, PJSIP_TSX_STATE_CALLING, PJSIP_TSX_STATE_TRYING, PJSIP_TSX_STATE_PROCEEDING, PJSIP_TSX_STATE_COMPLETED, PJSIP_TSX_STATE_CONFIRMED, PJSIP_TSX_STATE_TERMINATED, PJSIP_TSX_STATE_DESTROYED, PJSIP_TSX_STATE_MAX }
Functions
pj_status_t	pjsip_tsx_layer_init_module (pjsip_endpoint *endpt)
pjsip_module *	pjsip_tsx_layer_instance (void)
pj_status_t	pjsip_tsx_layer_destroy (void)
unsigned	pjsip_tsx_layer_get_tsx_count (void)
pjsip_transaction *	pjsip_tsx_layer_find_tsx (const pj_str_t *key, pj_bool_t lock)
pj_status_t	pjsip_tsx_create_uac (pjsip_module tsx_user, pjsip_tx_data tdata, pjsip_transaction **p_tsx)
pj_status_t	pjsip_tsx_create_uas (pjsip_module tsx_user, pjsip_rx_data rdata, pjsip_transaction **p_tsx)
pj_status_t	pjsip_tsx_set_transport (pjsip_transaction tsx, const pjsip_tpselector sel)
void	pjsip_tsx_recv_msg (pjsip_transaction tsx, pjsip_rx_data rdata)
pj_status_t	pjsip_tsx_send_msg (pjsip_transaction tsx, pjsip_tx_data tdata)
pj_status_t	pjsip_tsx_retransmit_no_state (pjsip_transaction tsx, pjsip_tx_data tdata)
pj_status_t	pjsip_tsx_create_key (pj_pool_t pool, pj_str_t key, pjsip_role_e role, const pjsip_method method, const pjsip_rx_data rdata)
pj_status_t	pjsip_tsx_terminate (pjsip_transaction *tsx, int code)
pj_status_t	pjsip_tsx_stop_retransmit (pjsip_transaction *tsx)
pj_status_t	pjsip_tsx_set_timeout (pjsip_transaction *tsx, unsigned millisec)
pjsip_transaction *	pjsip_rdata_get_tsx (pjsip_rx_data *rdata)

Enumeration Type Documentation

enum pjsip_tsx_state_e

This enumeration represents transaction state.

Enumerator:

PJSIP_TSX_STATE_NULL	For UAC, before any message is sent.
PJSIP_TSX_STATE_CALLING	For UAC, just after request is sent.
PJSIP_TSX_STATE_TRYING	For UAS, just after request is received.
PJSIP_TSX_STATE_PROCEEDING	For UAS/UAC, after provisional response.
PJSIP_TSX_STATE_COMPLETED	For UAS/UAC, after final response.
PJSIP_TSX_STATE_CONFIRMED	For UAS, after ACK is received.
PJSIP_TSX_STATE_TERMINATED	For UAS/UAC, before it's destroyed.
PJSIP_TSX_STATE_DESTROYED	For UAS/UAC, will be destroyed now.
PJSIP_TSX_STATE_MAX	Number of states.

Function Documentation

pj_status_t pjsip_tsx_layer_init_module ( pjsip_endpoint * endpt )

Create and register transaction layer module to the specified endpoint.

Parameters:

endpt

The endpoint instance.

Returns:: PJ_SUCCESS on success.

pjsip_module* pjsip_tsx_layer_instance ( void )

Get the instance of the transaction layer module.

Returns:: The transaction layer module.

pj_status_t pjsip_tsx_layer_destroy ( void )

Unregister and destroy transaction layer module.

Returns:: PJ_SUCCESS on success.

unsigned pjsip_tsx_layer_get_tsx_count ( void )

Retrieve the current number of transactions currently registered in the hash table.

Returns:: Number of transactions.

pjsip_transaction* pjsip_tsx_layer_find_tsx	(	const pj_str_t *	key,
		pj_bool_t	lock
	)

Find a transaction with the specified key. The transaction key normally is created by calling pjsip_tsx_create_key() from an incoming message.

Parameters:

	key	The key string to find the transaction.
	lock	If non-zero, transaction will be locked before the function returns, to make sure that it's not deleted by other threads.

Returns:: The matching transaction instance, or NULL if transaction can not be found.

pj_status_t pjsip_tsx_create_uac	(	pjsip_module *	tsx_user,
		pjsip_tx_data *	tdata,
		pjsip_transaction **	p_tsx
	)

Create, initialize, and register a new transaction as UAC from the specified transmit data (tdata). The transmit data must have a valid Request-Line and CSeq header.

If Via header does not exist, it will be created along with a unique branch parameter. If it exists and contains branch parameter, then the branch parameter will be used as is as the transaction key. If it exists but branch parameter doesn't exist, a unique branch parameter will be created.

Parameters:

	tsx_user	Module to be registered as transaction user of the new transaction, which will receive notification from the transaction via on_tsx_state() callback.
	tdata	The outgoing request message.
	p_tsx	On return will contain the new transaction instance.

Returns:: PJ_SUCCESS if successfull.

pj_status_t pjsip_tsx_create_uas	(	pjsip_module *	tsx_user,
		pjsip_rx_data *	rdata,
		pjsip_transaction **	p_tsx
	)

Create, initialize, and register a new transaction as UAS from the specified incoming request in rdata. After calling this function, application MUST call pjsip_tsx_recv_msg() so that transaction moves from state NULL.

Parameters:

	tsx_user	Module to be registered as transaction user of the new transaction, which will receive notification from the transaction via on_tsx_state() callback.
	rdata	The received incoming request.
	p_tsx	On return will contain the new transaction instance.

Returns:: PJ_SUCCESS if successfull.

pj_status_t pjsip_tsx_set_transport	(	pjsip_transaction *	tsx,
		const pjsip_tpselector *	sel
	)

Lock/bind transaction to a specific transport/listener. This is optional, as normally transport will be selected automatically based on the destination of the message upon resolver completion.

Parameters:

	tsx	The transaction.
	sel	Transport selector containing the specification of transport or listener to be used by this transaction to send requests.

Returns:: PJ_SUCCESS on success, or the appropriate error code.

void pjsip_tsx_recv_msg	(	pjsip_transaction *	tsx,
		pjsip_rx_data *	rdata
	)

Call this function to manually feed a message to the transaction. For UAS transaction, application MUST call this function after UAS transaction has been created.

This function SHOULD only be called to pass initial request message to UAS transaction. Before this function returns, on_tsx_state() callback of the transaction user will be called. If response message is passed to this function, then on_rx_response() will also be called before on_tsx_state().

Parameters:

	tsx	The transaction.
	rdata	The message.

pj_status_t pjsip_tsx_send_msg	(	pjsip_transaction *	tsx,
		pjsip_tx_data *	tdata
	)

Transmit message in tdata with this transaction. It is possible to pass NULL in tdata for UAC transaction, which in this case the last message transmitted, or the request message which was specified when calling pjsip_tsx_create_uac(), will be sent.

This function decrements the reference counter of the transmit buffer only when it returns PJ_SUCCESS;

Parameters:

	tsx	The transaction.
	tdata	The outgoing message. If NULL is specified, then the last message transmitted (or the message specified in UAC initialization) will be sent.

Returns:: PJ_SUCCESS if successfull.

pj_status_t pjsip_tsx_retransmit_no_state	(	pjsip_transaction *	tsx,
		pjsip_tx_data *	tdata
	)

Manually retransmit the last message transmitted by this transaction, without updating the transaction state. This function is useful when TU wants to maintain the retransmision by itself (for example, retransmitting reliable provisional response).

Parameters:

	tsx	The transaction.
	tdata	The outgoing message. If NULL is specified, then the last message transmitted (or the message specified in UAC initialization) will be sent.

Returns:: PJ_SUCCESS if successful.

pj_status_t pjsip_tsx_create_key	(	pj_pool_t *	pool,
		pj_str_t *	key,
		pjsip_role_e	role,
		const pjsip_method *	method,
		const pjsip_rx_data *	rdata
	)

Create transaction key, which is used to match incoming requests or response (retransmissions) against transactions.

Parameters:

	pool	The pool
	key	Output key.
	role	The role of the transaction.
	method	The method to be put as a key.
	rdata	The received data to calculate.

Returns:: PJ_SUCCESS or the appropriate error code.

pj_status_t pjsip_tsx_terminate	(	pjsip_transaction *	tsx,
		int	code
	)

Force terminate transaction.

Parameters:

	tsx	The transaction.
	code	The status code to report.

pj_status_t pjsip_tsx_stop_retransmit ( pjsip_transaction * tsx )

Cease retransmission on the UAC transaction. The UAC transaction is still considered running, and it will complete when either final response is received or the transaction times out.

This operation normally is used for INVITE transaction only, when the transaction is cancelled before any provisional response has been received.

Parameters:

tsx

The transaction.

Returns:: PJ_SUCCESS or the appropriate error code.

pj_status_t pjsip_tsx_set_timeout	(	pjsip_transaction *	tsx,
		unsigned	millisec
	)

Start a timer to terminate transaction after the specified time has elapsed. This function is only valid for INVITE transaction, and only before final response is received for the INVITE transaction. It is normally called after the UAC has sent CANCEL for this INVITE transaction.

The purpose of this function is to terminate the transaction if UAS does not send final response to this INVITE transaction even after it sends 200/OK to CANCEL (for example when the UAS complies to RFC 2543).

Once this timer is set, the transaction will be terminated either when a final response is received or the timer expires.

Parameters:

	tsx	The transaction.
	millisec	Timeout value in milliseconds.

Returns:: PJ_SUCCESS or the appropriate error code.

pjsip_transaction* pjsip_rdata_get_tsx ( pjsip_rx_data * rdata )

Get the transaction instance in the incoming message. If the message has a corresponding transaction, this function will return non NULL value.

Parameters:

rdata

The incoming message buffer.

Returns:: The transaction instance associated with this message, or NULL if the message doesn't match any transactions.

Transaction [Transaction Layer]

Data Structures

Enumerations

Functions

Enumeration Type Documentation

Function Documentation

Transaction
[Transaction Layer]