Group PJSIP_MOD

group PJSIP_MOD

Modules are the primary means to extend PJSIP!

Modules are the primary means to extend PJSIP. Without modules, PJSIP would not know how to handle messages, and will simply discard all incoming messages.

Modules are registered by creating and initializing pjsip_module structure, and register the structure to PJSIP with pjsip_endpt_register_module().

The PJSIP Developer’s Guide has a thorough discussion on this subject, and readers are encouraged to read the document for more information.

Enums

enum pjsip_module_priority

Module priority guidelines.

Values:

enumerator PJSIP_MOD_PRIORITY_TRANSPORT_LAYER

This is the priority used by transport layer.

enumerator PJSIP_MOD_PRIORITY_TSX_LAYER

This is the priority used by transaction layer.

enumerator PJSIP_MOD_PRIORITY_UA_PROXY_LAYER

This is the priority used by the user agent and proxy layer.

enumerator PJSIP_MOD_PRIORITY_DIALOG_USAGE

This is the priority used by the dialog usages.

enumerator PJSIP_MOD_PRIORITY_APPLICATION

This is the recommended priority to be used by applications.

struct pjsip_module

#include <sip_module.h>

The declaration for SIP module. This structure would be passed to pjsip_endpt_register_module() to register the module to PJSIP.

Forward declaration for module (sip_module.h).

Public Functions

PJ_DECL_LIST_MEMBER(struct pjsip_module)

To allow chaining of modules in the endpoint.

Public Members

pj_str_t name

Module name to identify the module.

This field MUST be initialized before registering the module.

int id

Module ID. Application must initialize this field with -1 before registering the module to PJSIP. After the module is registered, this field will contain a unique ID to identify the module.

int priority

Integer number to identify module initialization and start order with regard to other modules. Higher number will make the module gets initialized later.

This field MUST be initialized before registering the module.

pj_status_t (*load)(pjsip_endpoint *endpt)

Optional function to be called to initialize the module. This function will be called by endpoint during module registration. If the value is NULL, then it’s equal to returning PJ_SUCCESS.

Param endpt:

The endpoint instance.

Return:

Module should return PJ_SUCCESS to indicate success.

pj_status_t (*start)(void)

Optional function to be called to start the module. This function will be called by endpoint during module registration. If the value is NULL, then it’s equal to returning PJ_SUCCESS.

Return:

Module should return zero to indicate success.

pj_status_t (*stop)(void)

Optional function to be called to deinitialize the module before it is unloaded. This function will be called by endpoint during module unregistration. If the value is NULL, then it’s equal to returning PJ_SUCCESS.

Return:

Module should return PJ_SUCCESS to indicate success.

pj_status_t (*unload)(void)

Optional function to be called to deinitialize the module before it is unloaded. This function will be called by endpoint during module unregistration. If the value is NULL, then it’s equal to returning PJ_SUCCESS.

Param mod:

The module.

Return:

Module should return PJ_SUCCESS to indicate success.

pj_bool_t (*on_rx_request)(pjsip_rx_data *rdata)

Optional function to be called to process incoming request message.

Param rdata:

The incoming message.

Return:

Module should return PJ_TRUE if it handles the request, or otherwise it should return PJ_FALSE to allow other modules to handle the request.

pj_bool_t (*on_rx_response)(pjsip_rx_data *rdata)

Optional function to be called to process incoming response message.

Param rdata:

The incoming message.

Return:

Module should return PJ_TRUE if it handles the response, or otherwise it should return PJ_FALSE to allow other modules to handle the response.

pj_status_t (*on_tx_request)(pjsip_tx_data *tdata)

Optional function to be called when transport layer is about to transmit outgoing request message.

Param tdata:

The outgoing request message.

Return:

Module should return PJ_SUCCESS in all cases. If non-zero is returned, the message will not be sent.

pj_status_t (*on_tx_response)(pjsip_tx_data *tdata)

Optional function to be called when transport layer is about to transmit outgoing response message.

Param tdata:

The outgoing response message.

Return:

Module should return PJ_SUCCESS in all cases. If non-zero is returned, the message will not be sent.

void (*on_tsx_state)(pjsip_transaction *tsx, pjsip_event *event)

Optional function to be called when this module is acting as transaction user for the specified transaction, when the transaction’s state has changed.

Param tsx:

The transaction.

Param event:

The event which has caused the transaction state to change.