res_pjsip_mwi.c

	return 200;
}

static int mwi_subscription_established(struct ast_sip_subscription *sip_sub)
{
	const char *resource = ast_sip_subscription_get_resource_name(sip_sub);
	struct mwi_subscription *sub;
	struct ast_sip_endpoint *endpoint = ast_sip_subscription_get_endpoint(sip_sub);
	struct ao2_container *solicited_mwi;

	/* no aor in uri? subscribe to all on endpoint */
	if (ast_strlen_zero(resource)) {
		sub = mwi_subscribe_all(endpoint, sip_sub);
	} else {
		sub = mwi_subscribe_single(endpoint, sip_sub, resource);
	}
	if (!sub) {
		ao2_cleanup(endpoint);
		return -1;
	}

	if (!ao2_container_count(sub->stasis_subs)) {
		/*
		 * We setup no MWI subscriptions so remove the MWI datastore
		 * to break the ref loop.
		 */
		ast_sip_subscription_remove_datastore(sip_sub, MWI_DATASTORE);
	}

	solicited_mwi = ao2_global_obj_ref(mwi_solicited);
	if (solicited_mwi) {
		ao2_link(solicited_mwi, sub);
		ao2_ref(solicited_mwi, -1);
	}

	ao2_cleanup(sub);
	ao2_cleanup(endpoint);
	return 0;
}

static void *mwi_get_notify_data(struct ast_sip_subscription *sub)
{
	struct ast_sip_message_accumulator *counter;
	struct mwi_subscription *mwi_sub;
	struct ast_datastore *mwi_datastore;
	struct ast_sip_aor *aor;
	struct ast_sip_endpoint *endpoint = ast_sip_subscription_get_endpoint(sub);

	mwi_datastore = ast_sip_subscription_get_datastore(sub, MWI_DATASTORE);
	if (!mwi_datastore) {
		return NULL;
	}
	mwi_sub = mwi_datastore->data;

	counter = ao2_alloc(sizeof(*counter), NULL);
	if (!counter) {
		ao2_cleanup(mwi_datastore);
		return NULL;
	}

	if ((aor = find_aor_for_resource(endpoint, ast_sip_subscription_get_resource_name(sub)))) {
		pjsip_dialog *dlg = ast_sip_subscription_get_dialog(sub);
		pjsip_sip_uri *sip_uri = ast_sip_subscription_get_sip_uri(sub);

		if (dlg && sip_uri) {
			set_voicemail_extension(dlg->pool, sip_uri, counter, aor->voicemail_extension);
		}
		ao2_ref(aor, -1);
	}
	ao2_cleanup(endpoint);

	ao2_callback(mwi_sub->stasis_subs, OBJ_NODATA, get_message_count, counter);
	ao2_cleanup(mwi_datastore);
	return counter;
}

static void mwi_subscription_mailboxes_str(struct ao2_container *stasis_subs,
					   struct ast_str **str)
{
	int is_first = 1;
	struct mwi_stasis_subscription *node;
	struct ao2_iterator i = ao2_iterator_init(stasis_subs, 0);

	while ((node = ao2_iterator_next(&i))) {
		if (is_first) {
			is_first = 0;
			ast_str_append(str, 0, "%s", node->mailbox);
		} else {
			ast_str_append(str, 0, ",%s", node->mailbox);
		}
		ao2_ref(node, -1);
	}
	ao2_iterator_destroy(&i);
}

static void mwi_to_ami(struct ast_sip_subscription *sub,
		       struct ast_str **buf)
{
	struct mwi_subscription *mwi_sub;
	struct ast_datastore *mwi_datastore;

	mwi_datastore = ast_sip_subscription_get_datastore(sub, MWI_DATASTORE);
	if (!mwi_datastore) {
		return;
	}

	mwi_sub = mwi_datastore->data;

	ast_str_append(buf, 0, "SubscriptionType: mwi\r\n");
	ast_str_append(buf, 0, "Mailboxes: ");
	mwi_subscription_mailboxes_str(mwi_sub->stasis_subs, buf);
	ast_str_append(buf, 0, "\r\n");

	ao2_ref(mwi_datastore, -1);
}

static int serialized_notify(void *userdata)
{
	struct mwi_subscription *mwi_sub = userdata;

	send_mwi_notify(mwi_sub);
	ao2_ref(mwi_sub, -1);
	return 0;
}

static int serialized_cleanup(void *userdata)
{
	struct mwi_subscription *mwi_sub = userdata;

	/* This is getting rid of the reference that was added
	 * just before this serialized task was pushed.
	 */
	ao2_cleanup(mwi_sub);
	/* This is getting rid of the reference held by the
	 * stasis subscription
	 */
	ao2_cleanup(mwi_sub);
	return 0;
}

static int send_notify(void *obj, void *arg, int flags)
{
	struct mwi_subscription *mwi_sub = obj;
	struct ast_taskprocessor *serializer = mwi_sub->is_solicited
		? ast_sip_subscription_get_serializer(mwi_sub->sip_sub)
		: ast_serializer_pool_get(mwi_serializer_pool);

	if (ast_sip_push_task(serializer, serialized_notify, ao2_bump(mwi_sub))) {
		ao2_ref(mwi_sub, -1);
	}

	return 0;
}

static void mwi_stasis_cb(void *userdata, struct stasis_subscription *sub,
		struct stasis_message *msg)
{
	struct mwi_subscription *mwi_sub = userdata;

	if (stasis_subscription_final_message(sub, msg)) {
		if (ast_sip_push_task(ast_serializer_pool_get(mwi_serializer_pool),
				serialized_cleanup, ao2_bump(mwi_sub))) {
			ao2_ref(mwi_sub, -1);
		}
		return;
	}

	if (ast_mwi_state_type() == stasis_message_type(msg)) {
		send_notify(mwi_sub, NULL, 0);
	}
}

/*!
 * \internal
 * \brief Create unsolicited MWI subscriptions for an endpoint
 *
 * \note Call with the unsolicited_mwi container lock held.
 *
 * \param endpoint An endpoint object
 * \param recreate Whether or not unsolicited subscriptions are potentially being recreated
 * \param send_now Whether or not to send a notify once the subscription is created
 * \param unsolicited_mwi A container of unsolicited mwi objects
 * \param solicited_mwi A container of solicited mwi objects
 *
 * \retval 0
 */
static int create_unsolicited_mwi_subscriptions(struct ast_sip_endpoint *endpoint,
	int recreate, int send_now, struct ao2_container *unsolicited_mwi, struct ao2_container *solicited_mwi)
{
	RAII_VAR(struct mwi_subscription *, aggregate_sub, NULL, ao2_cleanup);
	char *mailboxes;
	char *mailbox;
	int sub_added = 0;

	if (ast_strlen_zero(endpoint->subscription.mwi.mailboxes)) {
		return 0;
	}

	if (endpoint->subscription.mwi.aggregate) {
		const char *endpoint_id = ast_sorcery_object_get_id(endpoint);

		/* Check if aggregate subscription exists */
		aggregate_sub = ao2_find(unsolicited_mwi, endpoint_id, OBJ_SEARCH_KEY | OBJ_NOLOCK);

		/*
		 * If enabled there should only ever exist a single aggregate subscription object
		 * for an endpoint. So if it exists just return unless subscriptions are potentially
		 * being added back in. If that's the case then continue.
		 */
		if (aggregate_sub && !recreate) {
			return 0;
		}

		if (!aggregate_sub) {
			aggregate_sub = mwi_subscription_alloc(endpoint, 0, NULL);
			if (!aggregate_sub) {
				return 0; /* No MWI aggregation for you */
			}

			/*
			 * Just in case we somehow get in the position of recreating with no previous
			 * aggregate object, set recreate to false here in order to allow the new
			 * object to be linked into the container below
			 */
			recreate = 0;
		}
	}

	/* Lock solicited so we don't potentially add to both containers */
	if (solicited_mwi) {
		ao2_lock(solicited_mwi);
	}

	mailboxes = ast_strdupa(endpoint->subscription.mwi.mailboxes);
	while ((mailbox = ast_strip(strsep(&mailboxes, ",")))) {
		struct mwi_subscription *sub;
		struct mwi_stasis_subscription *mwi_stasis_sub;

		if (!is_unsolicited_allowed(endpoint, mailbox, unsolicited_mwi, solicited_mwi)) {
			continue;
		}

		sub = aggregate_sub ?: mwi_subscription_alloc(endpoint, 0, NULL);
		if (!sub) {
			continue;
		}

		mwi_stasis_sub = mwi_stasis_subscription_alloc(mailbox, sub);
		if (mwi_stasis_sub) {
			ao2_link(sub->stasis_subs, mwi_stasis_sub);
			ao2_ref(mwi_stasis_sub, -1);
		}
		if (!aggregate_sub) {
			ao2_link_flags(unsolicited_mwi, sub, OBJ_NOLOCK);
			if (send_now) {
				send_notify(sub, NULL, 0);
			}
			ao2_ref(sub, -1);
		}

		if (aggregate_sub && !sub_added) {
			/* If aggregation track if at least one subscription has been added */
			sub_added = 1;
		}
	}

	if (aggregate_sub) {
		if (ao2_container_count(aggregate_sub->stasis_subs)) {
			/* Only link if we're dealing with a new aggregate object */
			if (!recreate) {
				ao2_link_flags(unsolicited_mwi, aggregate_sub, OBJ_NOLOCK);
			}
			if (send_now && sub_added) {
				send_notify(aggregate_sub, NULL, 0);
			}
		}
	}

	if (solicited_mwi) {
		ao2_unlock(solicited_mwi);
	}

	return 0;
}

static int create_mwi_subscriptions_for_endpoint(void *obj, void *arg, void *data, int flags)
{
	return create_unsolicited_mwi_subscriptions(obj, 0, 0, arg, data);
}

static int unsubscribe(void *obj, void *arg, int flags)
{
	struct mwi_subscription *mwi_sub = obj;

	ao2_callback(mwi_sub->stasis_subs, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, unsubscribe_stasis, NULL);

	return CMP_MATCH;
}

static void create_mwi_subscriptions(void)
{
	struct ao2_container *unsolicited_mwi;
	struct ao2_container *solicited_mwi;
	struct ao2_container *endpoints;
	struct ast_variable *var;

	unsolicited_mwi = ao2_global_obj_ref(mwi_unsolicited);
	if (!unsolicited_mwi) {
		return;
	}

	var = ast_variable_new("mailboxes !=", "", "");

	endpoints = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "endpoint",
		AST_RETRIEVE_FLAG_MULTIPLE, var);

	ast_variables_destroy(var);
	if (!endpoints) {
		ao2_ref(unsolicited_mwi, -1);
		return;
	}

	solicited_mwi = ao2_global_obj_ref(mwi_solicited);

	/* We remove all the old stasis subscriptions first before applying the new configuration. This
	 * prevents a situation where there might be multiple overlapping stasis subscriptions for an
	 * endpoint for mailboxes. Though there may be mailbox changes during the gap between unsubscribing
	 * and resubscribing, up-to-date mailbox state will be sent out to the endpoint when the
	 * new stasis subscription is established
	 */
	ao2_lock(unsolicited_mwi);
	ao2_callback(unsolicited_mwi, OBJ_NOLOCK | OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, unsubscribe, NULL);
	ao2_callback_data(endpoints, OBJ_NODATA, create_mwi_subscriptions_for_endpoint, unsolicited_mwi, solicited_mwi);
	ao2_unlock(unsolicited_mwi);

	ao2_ref(endpoints, -1);
	ao2_cleanup(solicited_mwi);
	ao2_ref(unsolicited_mwi, -1);
}

/*! \brief Function called to send MWI NOTIFY on any unsolicited mailboxes relating to this AOR */
static int send_contact_notify(void *obj, void *arg, int flags)
{
	struct mwi_subscription *mwi_sub = obj;
	const char *aor = arg;

	if (!mwi_sub->aors || !strstr(mwi_sub->aors, aor)) {
		return 0;
	}

	if (ast_sip_push_task(ast_serializer_pool_get(mwi_serializer_pool),
			serialized_notify, ao2_bump(mwi_sub))) {
		ao2_ref(mwi_sub, -1);
	}

	return 0;
}

/*! \brief Create mwi subscriptions and notify */
static void mwi_contact_changed(const struct ast_sip_contact *contact)
{
	char *id = ast_strdupa(ast_sorcery_object_get_id(contact));
	char *aor = NULL;
	struct ast_sip_endpoint *endpoint = NULL;
	struct ao2_container *unsolicited_mwi;
	struct ao2_container *solicited_mwi;

	if (contact->endpoint) {
		endpoint = ao2_bump(contact->endpoint);
	} else {
		if (!ast_strlen_zero(contact->endpoint_name)) {
			endpoint = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", contact->endpoint_name);
		}
	}

	if (!endpoint || ast_strlen_zero(endpoint->subscription.mwi.mailboxes)) {
		ao2_cleanup(endpoint);
		return;
	}

	unsolicited_mwi = ao2_global_obj_ref(mwi_unsolicited);
	if (!unsolicited_mwi) {
		ao2_cleanup(endpoint);
		return;
	}

	solicited_mwi = ao2_global_obj_ref(mwi_solicited);

	ao2_lock(unsolicited_mwi);
	create_unsolicited_mwi_subscriptions(endpoint, 0, 0, unsolicited_mwi, solicited_mwi);
	ao2_unlock(unsolicited_mwi);
	ao2_cleanup(endpoint);
	ao2_cleanup(solicited_mwi);
	ao2_ref(unsolicited_mwi, -1);

	aor = strsep(&id, ";@");
	ao2_callback(unsolicited_mwi, OBJ_NODATA, send_contact_notify, aor);
}

/*! \brief Function called when a contact is updated */
static void mwi_contact_updated(const void *object)
{
	mwi_contact_changed(object);
}

/*! \brief Function called when a contact is added */
static void mwi_contact_added(const void *object)
{
	mwi_contact_changed(object);
}

/*! \brief Function called when a contact is deleted */
static void mwi_contact_deleted(const void *object)
{
	const struct ast_sip_contact *contact = object;
	struct ao2_iterator *mwi_subs;
	struct mwi_subscription *mwi_sub;
	struct ast_sip_endpoint *endpoint = NULL;
	struct ast_sip_contact *found_contact;
	struct ao2_container *unsolicited_mwi;

	if (contact->endpoint) {
		endpoint = ao2_bump(contact->endpoint);
	} else {
		if (!ast_strlen_zero(contact->endpoint_name)) {
			endpoint = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", contact->endpoint_name);
		}
	}

	if (!endpoint || ast_strlen_zero(endpoint->subscription.mwi.mailboxes)) {
		ao2_cleanup(endpoint);
		return;
	}

	/* Check if there is another contact */
	found_contact = ast_sip_location_retrieve_contact_from_aor_list(endpoint->aors);
	ao2_cleanup(endpoint);
	if (found_contact) {
		ao2_cleanup(found_contact);
		return;
	}

	unsolicited_mwi = ao2_global_obj_ref(mwi_unsolicited);
	if (!unsolicited_mwi) {
		return;
	}

	ao2_lock(unsolicited_mwi);
	mwi_subs = ao2_find(unsolicited_mwi, contact->endpoint_name,
		OBJ_SEARCH_KEY | OBJ_MULTIPLE | OBJ_NOLOCK | OBJ_UNLINK);
	if (mwi_subs) {
		for (; (mwi_sub = ao2_iterator_next(mwi_subs)); ao2_cleanup(mwi_sub)) {
			unsubscribe(mwi_sub, NULL, 0);
		}
		ao2_iterator_destroy(mwi_subs);
	}
	ao2_unlock(unsolicited_mwi);
	ao2_ref(unsolicited_mwi, -1);
}

/*! \brief Observer for contacts so unsolicited MWI is sent when a contact changes */
static const struct ast_sorcery_observer mwi_contact_observer = {
	.created = mwi_contact_added,
	.updated = mwi_contact_updated,
	.deleted = mwi_contact_deleted,
};

/*! \brief Task invoked to send initial MWI NOTIFY for unsolicited */
static int send_initial_notify_all(void *obj)
{
	struct ao2_container *unsolicited_mwi = ao2_global_obj_ref(mwi_unsolicited);

	if (unsolicited_mwi) {
		ao2_callback(unsolicited_mwi, OBJ_NODATA, send_notify, NULL);
		ao2_ref(unsolicited_mwi, -1);
	}

	return 0;
}

/*! \brief Event callback which fires initial unsolicited MWI NOTIFY messages when we're fully booted */
static void mwi_startup_event_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message)
{
	struct ast_json_payload *payload;
	const char *type;

	if (stasis_message_type(message) != ast_manager_get_generic_type()) {
		return;
	}

	payload = stasis_message_data(message);
	type = ast_json_string_get(ast_json_object_get(payload->json, "type"));

	if (strcmp(type, "FullyBooted")) {
		return;
	}

	ast_sip_push_task(ast_serializer_pool_get(mwi_serializer_pool),
		send_initial_notify_all, NULL);

	stasis_unsubscribe(sub);
}

static void global_loaded(const char *object_type)
{
	ast_free(default_voicemail_extension);
	default_voicemail_extension = ast_sip_get_default_voicemail_extension();
	ast_serializer_pool_set_alerts(mwi_serializer_pool,
		ast_sip_get_mwi_tps_queue_high(), ast_sip_get_mwi_tps_queue_low());
}

static struct ast_sorcery_observer global_observer = {
	.loaded = global_loaded,
};

static int reload(void)
{
	if (!ast_sip_get_mwi_disable_initial_unsolicited()) {
		create_mwi_subscriptions();
	}
	return 0;
}

static int unload_module(void)
{
#if 0
	struct ao2_container *unsolicited_mwi;

	ast_sorcery_observer_remove(ast_sip_get_sorcery(), "global", &global_observer);
	ast_sorcery_observer_remove(ast_sip_get_sorcery(), "contact", &mwi_contact_observer);

	unsolicited_mwi = ao2_global_obj_replace(mwi_unsolicited, NULL);
	if (unsolicited_mwi) {
		ao2_callback(unsolicited_mwi, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, unsubscribe, NULL);
		ao2_ref(unsolicited_mwi, -1);
	}

	ao2_global_obj_release(mwi_solicited);

	if (ast_serializer_pool_destroy(mwi_serializer_pool)) {
		ast_log(LOG_WARNING, "Unload incomplete. Try again later\n");
		return -1;
	}
	mwi_serializer_pool = NULL;

	ast_sip_unregister_subscription_handler(&mwi_handler);

	ast_free(default_voicemail_extension);
	default_voicemail_extension = NULL;
	return 0;
#else
	/* If we were allowed to unload, the above is what we would do.
	 * pjsip_evsub_register_pkg is called by ast_sip_register_subscription_handler
	 * but there is no corresponding unregister function, so unloading
	 * a module does not remove the event package. If this module is ever
	 * loaded again, then pjproject will assert and cause a crash.
	 * For that reason, we must not be allowed to unload, but if
	 * a pjsip_evsub_unregister_pkg API is added in the future
	 * then we should go back to unloading the module as intended.
	 */
	return -1;
#endif
}

static int load_module(void)
{
	struct ao2_container *mwi_container;

	if (ast_sip_register_subscription_handler(&mwi_handler)) {
		return AST_MODULE_LOAD_DECLINE;
	}

	mwi_serializer_pool = ast_serializer_pool_create("pjsip/mwi",
		MWI_SERIALIZER_POOL_SIZE, ast_sip_threadpool(), MAX_UNLOAD_TIMEOUT_TIME);
	if (!mwi_serializer_pool) {
		ast_log(AST_LOG_WARNING, "Failed to create MWI serializer pool. The default SIP pool will be used for MWI\n");
	}

	mwi_container = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0, MWI_BUCKETS,
		mwi_sub_hash, NULL, mwi_sub_cmp);
	if (!mwi_container) {
		unload_module();
		return AST_MODULE_LOAD_DECLINE;
	}
	ao2_global_obj_replace_unref(mwi_solicited, mwi_container);
	ao2_ref(mwi_container, -1);

	mwi_container = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0, MWI_BUCKETS,
		mwi_sub_hash, NULL, mwi_sub_cmp);
	if (!mwi_container) {
		unload_module();
		return AST_MODULE_LOAD_DECLINE;
	}
	ao2_global_obj_replace_unref(mwi_unsolicited, mwi_container);
	ao2_ref(mwi_container, -1);

	ast_sorcery_observer_add(ast_sip_get_sorcery(), "contact", &mwi_contact_observer);
	ast_sorcery_observer_add(ast_sip_get_sorcery(), "global", &global_observer);
	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");

	if (!ast_sip_get_mwi_disable_initial_unsolicited()) {
		create_mwi_subscriptions();
		if (ast_test_flag(&ast_options, AST_OPT_FLAG_FULLY_BOOTED)) {
			ast_sip_push_task(ast_serializer_pool_get(mwi_serializer_pool),
				send_initial_notify_all, NULL);
		} else {
			struct stasis_subscription *sub;

			sub = stasis_subscribe_pool(ast_manager_get_topic(), mwi_startup_event_cb, NULL);
			stasis_subscription_accept_message_type(sub, ast_manager_get_generic_type());
			stasis_subscription_set_filter(sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
		}
	}

	if (!mwi_serializer_pool) {
		/*
		 * If the mwi serializer pool was unable to be established then the module will
		 * use the default serializer pool. If this happens prevent manual unloading
		 * since there would now exist the potential for a crash on unload.
		 */
		ast_module_shutdown_ref(ast_module_info->self);
	}

	return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP MWI resource",
	.support_level = AST_MODULE_SUPPORT_CORE,
	.load = load_module,
	.unload = unload_module,
	.reload = reload,
	.load_pri = AST_MODPRI_CHANNEL_DEPEND + 5,
	.requires = "res_pjsip,res_pjsip_pubsub",
);