res_pjsip: Enable unload of all modules at shutdown.

* Move most of res_pjsip:module_unload to unload_pjsip to resolve crashes
  caused by running PJSIP functions from non-PJSIP threads.
* Remove call to pjsip_endpt_destroy(ast_pjsip_endpoint), it was causing
  crashes in some cases.  In theory pj_shutdown() should take care of this.
* Mark res_pjsip_keepalive and res_pjsip_session as allowed to unload at
  shutdown.
* Resolve leaked config global in res_pjsip_notify.
* Unregister pubsub pjsip service module.
* Implement cleanup for res_pjsip_session.

ASTERISK-24731 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/4498/
........

Merged revisions 433469 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@433470 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip.c

@@ -3520,14 +3520,21 @@ static int reload_module(void)
 static int unload_pjsip(void *data)
 {
 	ast_cli_unregister_multiple(cli_commands, ARRAY_LEN(cli_commands));
+	ast_res_pjsip_cleanup_options_handling();
+	internal_sip_destroy_outbound_authentication();
+	ast_sip_destroy_distributor();
+	ast_res_pjsip_destroy_configuration();
+	ast_sip_destroy_system();
+	ast_sip_destroy_global_headers();
+	internal_sip_unregister_service(&supplement_module);
+	if (monitor_thread) {
+		stop_monitor_thread();
+	}
 	if (memory_pool) {
 		pj_pool_release(memory_pool);
 		memory_pool = NULL;
 	}
-	if (ast_pjsip_endpoint) {
-		pjsip_endpt_destroy(ast_pjsip_endpoint);
 	ast_pjsip_endpoint = NULL;
-	}
 	pj_caching_pool_destroy(&caching_pool);
 	pj_shutdown();
 	return 0;
@@ -3535,16 +3542,6 @@ static int unload_pjsip(void *data)
 
 static int unload_module(void)
 {
-	ast_res_pjsip_cleanup_options_handling();
-	internal_sip_destroy_outbound_authentication();
-	ast_sip_destroy_distributor();
-	ast_res_pjsip_destroy_configuration();
-	ast_sip_destroy_system();
-	ast_sip_destroy_global_headers();
-	internal_sip_unregister_service(&supplement_module);
-	if (monitor_thread) {
-		stop_monitor_thread();
-	}
 	/* The thread this is called from cannot call PJSIP/PJLIB functions,
 	 * so we have to push the work to the threadpool to handle
 	 */

res/res_pjsip_keepalive.c

@@ -244,7 +244,7 @@ static int load_module(void)
 
 	ast_sorcery_observer_add(ast_sip_get_sorcery(), "global", &keepalive_global_observer);
 	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");
-	ast_module_ref(ast_module_info->self);
+	ast_module_shutdown_ref(ast_module_info->self);
 	return AST_MODULE_LOAD_SUCCESS;
 }
 

res/res_pjsip_notify.c

@@ -1021,6 +1021,7 @@ static int unload_module(void)
 	ast_manager_unregister("PJSIPNotify");
 	ast_cli_unregister_multiple(cli_options, ARRAY_LEN(cli_options));
 	aco_info_destroy(&notify_cfg);
+	ao2_global_obj_release(globals);
 
 	return 0;
 }

res/res_pjsip_pubsub.c

@@ -4286,6 +4286,7 @@ static int unload_module(void)
 	ast_manager_unregister(AMI_SHOW_SUBSCRIPTIONS_INBOUND);
 	ast_manager_unregister("PJSIPShowResourceLists");
 
+	ast_sip_unregister_service(&pubsub_module);
 	if (sched) {
 		ast_sched_context_destroy(sched);
 	}

res/res_pjsip_session.c

@@ -2641,14 +2641,18 @@ static int load_module(void)
 	}
 	ast_sip_register_service(&session_reinvite_module);
 
-	ast_module_ref(ast_module_info->self);
+	ast_module_shutdown_ref(ast_module_info->self);
 
 	return AST_MODULE_LOAD_SUCCESS;
 }
 
 static int unload_module(void)
 {
-	/* This will never get called as this module can't be unloaded */
+	ast_sip_unregister_service(&session_reinvite_module);
+	ast_sip_unregister_service(&session_module);
+	ast_sorcery_delete(ast_sip_get_sorcery(), nat_hook);
+	ao2_cleanup(nat_hook);
+	ao2_cleanup(sdp_handlers);
 	return 0;
 }