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asterisk/include/asterisk/res_sip_pubsub.h

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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2013, Digium, Inc.
*
* Mark Michelson <mmichelson@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
#ifndef _RES_SIP_PUBSUB_H
#define _RES_SIP_PUBSUB_H
#include "asterisk/linkedlists.h"
/* Forward declarations */
struct pjsip_rx_data;
struct pjsip_tx_data;
struct pjsip_evsub;
struct ast_sip_endpoint;
struct ast_datastore;
struct ast_datastore_info;
/*!
* \brief Opaque structure representing an RFC 3265 SIP subscription
*/
struct ast_sip_subscription;
/*!
* \brief Role for the subscription that is being created
*/
enum ast_sip_subscription_role {
/* Sending SUBSCRIBEs, receiving NOTIFYs */
AST_SIP_SUBSCRIBER,
/* Sending NOTIFYs, receiving SUBSCRIBEs */
AST_SIP_NOTIFIER,
};
/*!
* \brief Data for responses to SUBSCRIBEs and NOTIFIEs
*
* Some of PJSIP's evsub callbacks expect us to provide them
* with data so that they can craft a response rather than have
* us create our own response.
*
* Filling in the structure is optional, since the framework
* will automatically respond with a 200 OK response if we do
* not provide it with any additional data.
*/
struct ast_sip_subscription_response_data {
/*! Status code of the response */
int status_code;
/*! Optional status text */
const char *status_text;
/*! Optional additional headers to add to the response */
struct ast_variable *headers;
/*! Optional body to add to the response */
struct ast_sip_body *body;
};
#define AST_SIP_MAX_ACCEPT 32
struct ast_sip_subscription_handler {
/*! The name of the event this handler deals with */
const char *event_name;
/*! The types of body this handler accepts */
const char *accept[AST_SIP_MAX_ACCEPT];
/*!
* \brief Called when a subscription is to be destroyed
*
* This is a subscriber and notifier callback.
*
* The handler is not expected to send any sort of requests or responses
* during this callback. The handler MUST, however, begin the destruction
* process for the subscription during this callback.
*/
void (*subscription_shutdown)(struct ast_sip_subscription *subscription);
/*!
* \brief Called when a SUBSCRIBE arrives in order to create a new subscription
*
* This is a notifier callback.
*
* If the notifier wishes to accept the subscription, then it can create
* a new ast_sip_subscription to do so.
*
* If the notifier chooses to create a new subscription, then it must accept
* the incoming subscription using pjsip_evsub_accept() and it must also
* send an initial NOTIFY with the current subscription state.
*
* \param endpoint The endpoint from which we received the SUBSCRIBE
* \param rdata The SUBSCRIBE request
* \retval NULL The SUBSCRIBE has not been accepted
* \retval non-NULL The newly-created subscription
*/
struct ast_sip_subscription *(*new_subscribe)(struct ast_sip_endpoint *endpoint,
pjsip_rx_data *rdata);
/*!
* \brief Called when an endpoint renews a subscription.
*
* This is a notifier callback.
*
* Because of the way that the PJSIP evsub framework works, it will automatically
* send a response to the SUBSCRIBE. However, the subscription handler must send
* a NOTIFY with the current subscription state when this callback is called.
*
* The response_data that is passed into this callback is used to craft what should
* be in the response to the incoming SUBSCRIBE. It is initialized with a 200 status
* code and all other parameters are empty.
*
* \param sub The subscription that is being renewed
* \param rdata The SUBSCRIBE request in question
* \param[out] response_data Data pertaining to the SIP response that should be
* sent to the SUBSCRIBE
*/
void (*resubscribe)(struct ast_sip_subscription *sub,
pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
/*!
* \brief Called when a subscription times out.
*
* This is a notifier callback
*
* This indicates that the subscription has timed out. The subscription handler is
* expected to send a NOTIFY that terminates the subscription.
*
* \param sub The subscription that has timed out
*/
void (*subscription_timeout)(struct ast_sip_subscription *sub);
/*!
* \brief Called when a subscription is terminated via a SUBSCRIBE or NOTIFY request
*
* This is a notifier and subscriber callback.
*
* The PJSIP subscription framework will automatically send the response to the
* request. If a notifier receives this callback, then the subscription handler
* is expected to send a final NOTIFY to terminate the subscription.
*
* \param sub The subscription being terminated
* \param rdata The request that terminated the subscription
*/
void (*subscription_terminated)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
/*!
* \brief Called when a subscription handler's outbound NOTIFY receives a response
*
* This is a notifier callback.
*
* \param sub The subscription
* \param rdata The NOTIFY response
*/
void (*notify_response)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
/*!
* \brief Called when a subscription handler receives an inbound NOTIFY
*
* This is a subscriber callback.
*
* Because of the way that the PJSIP evsub framework works, it will automatically
* send a response to the NOTIFY. By default this will be a 200 OK response, but
* this callback can change details of the response by returning response data
* to use.
*
* The response_data that is passed into this callback is used to craft what should
* be in the response to the incoming SUBSCRIBE. It is initialized with a 200 status
* code and all other parameters are empty.
*
* \param sub The subscription
* \param rdata The NOTIFY request
* \param[out] response_data Data pertaining to the SIP response that should be
* sent to the SUBSCRIBE
*/
void (*notify_request)(struct ast_sip_subscription *sub,
pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
/*!
* \brief Called when it is time for a subscriber to resubscribe
*
* This is a subscriber callback.
*
* The subscriber can reresh the subscription using the pjsip_evsub_initiate()
* function.
*
* \param sub The subscription to refresh
* \retval 0 Success
* \retval non-zero Failure
*/
int (*refresh_subscription)(struct ast_sip_subscription *sub);
AST_LIST_ENTRY(ast_sip_subscription_handler) next;
};
/*!
* \brief Create a new ast_sip_subscription structure
*
* In most cases the pubsub core will create a general purpose subscription
* within PJSIP. However, PJSIP provides enhanced support for the following
* event packages:
*
* presence
* message-summary
*
* If either of these events are handled by the subscription handler, then
* the special-purpose event subscriptions will be created within PJSIP,
* and it will be expected that your subscription handler make use of the
* special PJSIP APIs.
*
* \param handler The subsription handler for this subscription
* \param role Whether we are acting as subscriber or notifier for this subscription
* \param endpoint The endpoint involved in this subscription
* \param rdata If acting as a notifier, the SUBSCRIBE request that triggered subscription creation
*/
struct ast_sip_subscription *ast_sip_create_subscription(const struct ast_sip_subscription_handler *handler,
enum ast_sip_subscription_role role, struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
/*!
* \brief Get the endpoint that is associated with this subscription
*
* This function will increase the reference count of the endpoint. Be sure to
* release the reference to it when you are finished with the endpoint.
*
* \retval NULL Could not get endpoint
* \retval non-NULL The endpoint
*/
struct ast_sip_endpoint *ast_sip_subscription_get_endpoint(struct ast_sip_subscription *sub);
/*!
* \brief Get the serializer for the subscription
*
* Tasks that originate outside of a SIP servant thread should get the serializer
* and push the task to the serializer.
*
* \param sub The subscription
* \retval NULL Failure
* \retval non-NULL The subscription's serializer
*/
struct ast_taskprocessor *ast_sip_subscription_get_serializer(struct ast_sip_subscription *sub);
/*!
* \brief Get the underlying PJSIP evsub structure
*
* This is useful when wishing to call PJSIP's API calls in order to
* create SUBSCRIBEs, NOTIFIES, etc. as well as get subscription state
*
* This function, as well as all methods called on the pjsip_evsub should
* be done in a SIP servant thread.
*
* \param sub The subscription
* \retval NULL Failure
* \retval non-NULL The underlying pjsip_evsub
*/
pjsip_evsub *ast_sip_subscription_get_evsub(struct ast_sip_subscription *sub);
/*!
* \brief Send a request created via a PJSIP evsub method
*
* Callers of this function should take care to do so within a SIP servant
* thread.
*
* \param sub The subscription on which to send the request
* \param tdata The request to send
* \retval 0 Success
* \retval non-zero Failure
*/
int ast_sip_subscription_send_request(struct ast_sip_subscription *sub, pjsip_tx_data *tdata);
/*!
* \brief Alternative for ast_datastore_alloc()
*
* There are two major differences between this and ast_datastore_alloc()
* 1) This allocates a refcounted object
* 2) This will fill in a uid if one is not provided
*
* DO NOT call ast_datastore_free() on a datastore allocated in this
* way since that function will attempt to free the datastore rather
* than play nicely with its refcount.
*
* \param info Callbacks for datastore
* \param uid Identifier for datastore
* \retval NULL Failed to allocate datastore
* \retval non-NULL Newly allocated datastore
*/
struct ast_datastore *ast_sip_subscription_alloc_datastore(const struct ast_datastore_info *info, const char *uid);
/*!
* \brief Add a datastore to a SIP subscription
*
* Note that SIP uses reference counted datastores. The datastore passed into this function
* must have been allocated using ao2_alloc() or there will be serious problems.
*
* \param subscription The ssubscription to add the datastore to
* \param datastore The datastore to be added to the subscription
* \retval 0 Success
* \retval -1 Failure
*/
int ast_sip_subscription_add_datastore(struct ast_sip_subscription *subscription, struct ast_datastore *datastore);
/*!
* \brief Retrieve a subscription datastore
*
* The datastore retrieved will have its reference count incremented. When the caller is done
* with the datastore, the reference counted needs to be decremented using ao2_ref().
*
* \param subscription The subscription from which to retrieve the datastore
* \param name The name of the datastore to retrieve
* \retval NULL Failed to find the specified datastore
* \retval non-NULL The specified datastore
*/
struct ast_datastore *ast_sip_subscription_get_datastore(struct ast_sip_subscription *subscription, const char *name);
/*!
* \brief Remove a subscription datastore from the subscription
*
* This operation may cause the datastore's free() callback to be called if the reference
* count reaches zero.
*
* \param subscription The subscription to remove the datastore from
* \param name The name of the datastore to remove
*/
void ast_sip_subscription_remove_datastore(struct ast_sip_subscription *subscription, const char *name);
/*!
* \brief Register a subscription handler
*
* \retval 0 Handler was registered successfully
* \retval non-zero Handler was not registered successfully
*/
int ast_sip_register_subscription_handler(struct ast_sip_subscription_handler *handler);
/*!
* \brief Unregister a subscription handler
*/
void ast_sip_unregister_subscription_handler(struct ast_sip_subscription_handler *handler);
#endif /* RES_SIP_PUBSUB_H */