Allow res_parking to be unloadable

This change protects accesses of res_parking such that it can unload
safely once transient uses of its registered functions are complete.
The parking API has been restructured such that its consumers do not
have access to the vtable exposed by the parking provider, but instead
route through stubs to prevent consumers from holding on to function
pointers.

This adds calls to all the parking unload functions and moves
application loading and unloading into functions in
parking_applications.c similar to the rest of the parts of res_parking.

Review: https://reviewboard.asterisk.org/r/2763/
(closes issue ASTERISK-22142)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@396890 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 66 insertions, 4 deletions

diff --git a/include/asterisk/parking.h b/include/asterisk/parking.h
index 25149854a..8b2b4b409 100644
--- a/include/asterisk/parking.h
+++ b/include/asterisk/parking.h
@@ -114,6 +114,8 @@ struct stasis_message_type *ast_parked_call_type(void);
 
 #define PARKING_MODULE_VERSION 1
 
+struct ast_module_info;
+
 /*!
  * \brief A function table providing parking functionality to the \ref AstBridging
  * Bridging API and other consumers
@@ -188,15 +190,67 @@ struct ast_parking_bridge_feature_fn_table {
 	 * \retval non-zero on error
 	 */
 	int (* parking_park_bridge_channel)(struct ast_bridge_channel *parkee, const char *parkee_uuid, const char *parker_uuid, const char *app_data);
+
+	/*! \brief The module info for the module registering this parking provider */
+	const struct ast_module_info *module_info;
 };
 
 /*!
- * \brief Obtain the current parking provider
+ * \brief Determine if the context/exten is a "parking" extension
+ *
+ * \retval 0 if the extension is not a parking extension
+ * \retval 1 if the extension is a parking extension
+ */
+int ast_parking_is_exten_park(const char *context, const char *exten);
+
+/*!
+ * \brief Park the bridge and/or callers that this channel is in
+ *
+ * \param parker The bridge_channel parking the bridge
+ * \param exten Optional. The extension the channel or bridge was parked at if the
+ * call succeeds.
+ * \param length Optional. If \c exten is specified, the size of the buffer.
+ *
+ * \note This is safe to be called outside of the \ref AstBridging Bridging API.
+ *
+ * \retval 0 on success
+ * \retval non-zero on error
+ */
+int ast_parking_park_call(struct ast_bridge_channel *parker, char *exten, size_t length);
+
+/*!
+ * \brief Perform a blind transfer to a parking extension.
+ *
+ * \param parker The \ref bridge_channel object that is initiating the parking
+ * \param context The context to blind transfer to
+ * \param exten The extension to blind transfer to
+ *
+ * \note If the bridge \ref parker is in has more than one other occupant, the entire
+ * bridge will be parked using a Local channel
+ *
+ * \note This is safe to be called outside of the \ref AstBridging Bridging API.
+ *
+ * \retval 0 on success
+ * \retval non-zero on error
+ */
+int ast_parking_blind_transfer_park(struct ast_bridge_channel *parker, const char *context, const char *exten);
+
+/*!
+ * \brief Perform a direct park on a channel in a bridge.
  *
- * \retval NULL if no provider exists
- * \retval an ao2 ref counted object of the existing provider's function table
+ * \param parkee The channel in the bridge to be parked.
+ * \param parkee_uuid The UUID of the channel being packed.
+ * \param parker_uuid The UUID of the channel performing the park.
+ * \param app_data Data to pass to the Park application
+ *
+ * \note This must be called within the context of the \ref AstBridging Bridging API.
+ * External entities should not call this method directly, but should instead use
+ * the direct call parking method or the blind transfer method.
+ *
+ * \retval 0 on success
+ * \retval non-zero on error
  */
-struct ast_parking_bridge_feature_fn_table *ast_parking_get_bridge_features(void);
+int ast_parking_park_bridge_channel(struct ast_bridge_channel *parkee, const char *parkee_uuid, const char *parker_uuid, const char *app_data);
 
 /*!
  * \brief Register a parking provider
@@ -217,3 +271,11 @@ int ast_parking_register_bridge_features(struct ast_parking_bridge_feature_fn_ta
  * \retval -1 on error
  */
 int ast_parking_unregister_bridge_features(const char *module_name);
+
+/*!
+ * \brief Check whether a parking provider is registered
+ *
+ * \retval 0 if there is no parking provider regsistered
+ * \retval 1 if there is a parking provider regsistered
+ */
+int ast_parking_provider_registered(void);