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, 78 insertions, 12 deletions

diff --git a/main/parking.c b/main/parking.c
index 83c599ba0..9a92e6e15 100644
--- a/main/parking.c
+++ b/main/parking.c
@@ -34,6 +34,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/parking.h"
 #include "asterisk/channel.h"
 #include "asterisk/_private.h"
+#include "asterisk/module.h"
 
 /*! \brief Message type for parked calls */
 STASIS_MESSAGE_TYPE_DEFN(ast_parked_call_type);
@@ -124,19 +125,77 @@ struct ast_parked_call_payload *ast_parked_call_payload_create(enum ast_parked_c
 	return payload;
 }
 
-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)
 {
-	return (struct ast_parking_bridge_feature_fn_table*)ao2_global_obj_ref(parking_provider);
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, table,
+		ao2_global_obj_ref(parking_provider), ao2_cleanup);
+
+	if (!table || !table->parking_park_bridge_channel) {
+		return -1;
+	}
+
+	if (table->module_info) {
+		SCOPED_MODULE_USE(table->module_info->self);
+		return table->parking_park_bridge_channel(parkee, parkee_uuid, parker_uuid, app_data);
+	}
+
+	return table->parking_park_bridge_channel(parkee, parkee_uuid, parker_uuid, app_data);
 }
 
-/*! \brief A wrapper around the fn_table to ao2-ify it */
-struct parking_provider_wrapper {
-	struct ast_parking_bridge_feature_fn_table fn_table;
-};
+int ast_parking_blind_transfer_park(struct ast_bridge_channel *parker, const char *context, const char *exten)
+{
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, table,
+		ao2_global_obj_ref(parking_provider), ao2_cleanup);
+
+	if (!table || !table->parking_blind_transfer_park) {
+		return -1;
+	}
+
+	if (table->module_info) {
+		SCOPED_MODULE_USE(table->module_info->self);
+		return table->parking_blind_transfer_park(parker, context, exten);
+	}
+
+	return table->parking_blind_transfer_park(parker, context, exten);
+}
+
+int ast_parking_park_call(struct ast_bridge_channel *parker, char *exten, size_t length)
+{
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, table,
+		ao2_global_obj_ref(parking_provider), ao2_cleanup);
+
+	if (!table || !table->parking_park_call) {
+		return -1;
+	}
+
+	if (table->module_info) {
+		SCOPED_MODULE_USE(table->module_info->self);
+		return table->parking_park_call(parker, exten, length);
+	}
+
+	return table->parking_park_call(parker, exten, length);
+}
+
+int ast_parking_is_exten_park(const char *context, const char *exten)
+{
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, table,
+		ao2_global_obj_ref(parking_provider), ao2_cleanup);
+
+	if (!table || !table->parking_is_exten_park) {
+		return -1;
+	}
+
+	if (table->module_info) {
+		SCOPED_MODULE_USE(table->module_info->self);
+		return table->parking_is_exten_park(context, exten);
+	}
+
+	return table->parking_is_exten_park(context, exten);
+}
 
 int ast_parking_register_bridge_features(struct ast_parking_bridge_feature_fn_table *fn_table)
 {
-	RAII_VAR(struct parking_provider_wrapper *, wrapper,
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, wrapper,
 		ao2_global_obj_ref(parking_provider), ao2_cleanup);
 
 	if (fn_table->module_version != PARKING_MODULE_VERSION) {
@@ -147,7 +206,7 @@ int ast_parking_register_bridge_features(struct ast_parking_bridge_feature_fn_ta
 
 	if (wrapper) {
 		ast_log(AST_LOG_WARNING, "Parking provider already registered by %s!\n",
-			wrapper->fn_table.module_name);
+			wrapper->module_name);
 		return -1;
 	}
 
@@ -155,7 +214,7 @@ int ast_parking_register_bridge_features(struct ast_parking_bridge_feature_fn_ta
 	if (!wrapper) {
 		return -1;
 	}
-	wrapper->fn_table = *fn_table;
+	*wrapper = *fn_table;
 
 	ao2_global_obj_replace(parking_provider, wrapper);
 	return 0;
@@ -163,15 +222,14 @@ int ast_parking_register_bridge_features(struct ast_parking_bridge_feature_fn_ta
 
 int ast_parking_unregister_bridge_features(const char *module_name)
 {
-	RAII_VAR(struct parking_provider_wrapper *, wrapper,
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, wrapper,
 		ao2_global_obj_ref(parking_provider), ao2_cleanup);
 
 	if (!wrapper) {
-		ast_log(AST_LOG_WARNING, "No parking provider to unregister\n");
 		return -1;
 	}
 
-	if (strcmp(wrapper->fn_table.module_name, module_name)) {
+	if (strcmp(wrapper->module_name, module_name)) {
 		ast_log(AST_LOG_WARNING, "%s has not registered the parking provider\n", module_name);
 		return -1;
 	}
@@ -179,3 +237,11 @@ int ast_parking_unregister_bridge_features(const char *module_name)
 	ao2_global_obj_replace_unref(parking_provider, NULL);
 	return 0;
 }
+
+int ast_parking_provider_registered(void)
+{
+	RAII_VAR(struct ast_parking_bridge_feature_fn_table *, table,
+		ao2_global_obj_ref(parking_provider), ao2_cleanup);
+
+	return !!table;
+}