pbx: Add helper function to execute applications.

Finding an application and executing it if found is
a common task throughout Asterisk. This adds a helper
function around pbx_exec to do this, to eliminate
redundant code and make it easier for modules to
substitute variables and execute applications by name.

ASTERISK-30061 #close

Change-Id: Ifee4d2825df7545fb515d763d393065675140c84

apps/app_disa.c

@@ -361,7 +361,6 @@ static int disa_exec(struct ast_channel *chan, const char *data)
 
 	if (k == 3) {
 		int recheck = 0;
-		struct ast_app *app_reset_cdr;
 
 		if (!ast_exists_extension(chan, args.context, exten, 1,
 			S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
@@ -386,10 +385,7 @@ static int disa_exec(struct ast_channel *chan, const char *data)
 				ast_channel_unlock(chan);
 			}
 
-			app_reset_cdr = pbx_findapp("ResetCDR");
-			if (app_reset_cdr) {
-				pbx_exec(chan, app_reset_cdr, special_noanswer ? "" : "e");
-			} else {
+			if (ast_pbx_exec_application(chan, "ResetCDR", special_noanswer ? "" : "e")) {
 				ast_log(AST_LOG_NOTICE, "ResetCDR application not found; CDR will not be reset\n");
 			}
 			ast_explicit_goto(chan, args.context, exten, 1);

include/asterisk/pbx.h

@@ -268,6 +268,23 @@ struct ast_app *pbx_findapp(const char *app);
  */
 int pbx_exec(struct ast_channel *c, struct ast_app *app, const char *data);
 
+/*!
+ * \brief Execute an application
+ *
+ * \param c channel to execute on
+ * \param app name of app to execute
+ * \param data the data passed into the app
+ *
+ * This application executes an application by name on a given channel.
+ * It is a wrapper around pbx_exec that will perform variable substitution
+ * and then execute the application if it exists.
+ * If the application is not found, a warning is logged.
+ *
+ * \retval 0 success
+ * \retval -1 failure (including application not found)
+ */
+int ast_pbx_exec_application(struct ast_channel *chan, const char *app_name, const char *app_args);
+
 /*!
  * \brief Register a new context or find an existing one
  *

main/bridge_channel.c

@@ -1178,23 +1178,7 @@ static int run_app_helper(struct ast_channel *chan, const char *app_name, const
 	} else if (!strcasecmp("Macro", app_name)) {
 		ast_app_exec_macro(NULL, chan, app_args);
 	} else {
-		struct ast_app *app;
-
-		app = pbx_findapp(app_name);
-		if (!app) {
-			ast_log(LOG_WARNING, "Could not find application (%s)\n", app_name);
-		} else {
-			struct ast_str *substituted_args = ast_str_create(16);
-
-			if (substituted_args) {
-				ast_str_substitute_variables(&substituted_args, 0, chan, app_args);
-				res = pbx_exec(chan, app, ast_str_buffer(substituted_args));
-				ast_free(substituted_args);
-			} else {
-				ast_log(LOG_WARNING, "Could not substitute application argument variables for %s\n", app_name);
-				res = pbx_exec(chan, app, app_args);
-			}
-		}
+		res = ast_pbx_exec_application(chan, app_name, app_args);
 	}
 	return res;
 }

main/dial.c

@@ -166,14 +166,12 @@ static int predial_disable(void *data)
 static void answer_exec_run(struct ast_dial *dial, struct ast_dial_channel *dial_channel, char *app, char *args)
 {
 	struct ast_channel *chan = dial_channel->owner;
-	struct ast_app *ast_app = pbx_findapp(app);
 
+	/* Execute the application, if available */
+	if (ast_pbx_exec_application(chan, app, args)) {
 		/* If the application was not found, return immediately */
-	if (!ast_app)
 		return;
-
-	/* All is well... execute the application */
-	pbx_exec(chan, ast_app, args);
+	}
 
 	/* If another thread is not taking over hang up the channel */
 	ast_mutex_lock(&dial->lock);

main/features.c

@@ -504,12 +504,7 @@ static void bridge_check_monitor(struct ast_channel *chan, struct ast_channel *p
 		ast_channel_unlock(peer);
 	}
 	if (monitor_chan) {
-		struct ast_app *monitor_app;
-
-		monitor_app = pbx_findapp("Monitor");
-		if (monitor_app) {
-			pbx_exec(monitor_chan, monitor_app, monitor_args);
-		}
+		ast_pbx_exec_application(monitor_chan, "Monitor", monitor_args);
 	}
 }
 

main/pbx_app.c

@@ -498,6 +498,31 @@ int pbx_exec(struct ast_channel *c,	/*!< Channel */
 	return res;
 }
 
+int ast_pbx_exec_application(struct ast_channel *chan, const char *app_name, const char *app_args)
+{
+	int res = -1;
+	struct ast_app *app;
+
+	app = pbx_findapp(app_name);
+	if (!app) {
+		ast_log(LOG_WARNING, "Could not find application (%s)\n", app_name);
+	} else {
+		struct ast_str *substituted_args = NULL;
+
+		if (!ast_strlen_zero(app_args) && (substituted_args = ast_str_create(16))) {
+			ast_str_substitute_variables(&substituted_args, 0, chan, app_args);
+			res = pbx_exec(chan, app, ast_str_buffer(substituted_args));
+			ast_free(substituted_args);
+		} else {
+			if (!ast_strlen_zero(app_args)) {
+				ast_log(LOG_WARNING, "Could not substitute application argument variables for %s\n", app_name);
+			}
+			res = pbx_exec(chan, app, app_args);
+		}
+	}
+	return res;
+}
+
 static struct ast_cli_entry app_cli[] = {
 	AST_CLI_DEFINE(handle_show_applications, "Shows registered dialplan applications"),
 	AST_CLI_DEFINE(handle_show_application, "Describe a specific dialplan application"),

main/pbx_builtins.c

@@ -1000,7 +1000,6 @@ static int pbx_builtin_execiftime(struct ast_channel *chan, const char *data)
 {
 	char *s, *appname;
 	struct ast_timing timing;
-	struct ast_app *app;
 	static const char * const usage = "ExecIfTime requires an argument:\n  <time range>,<days of week>,<days of month>,<months>[,<timezone>]?<appname>[(<appargs>)]";
 
 	if (ast_strlen_zero(data)) {
@@ -1038,13 +1037,7 @@ static int pbx_builtin_execiftime(struct ast_channel *chan, const char *data)
 			ast_log(LOG_WARNING, "Failed to find closing parenthesis\n");
 	}
 
-
-	if ((app = pbx_findapp(appname))) {
-		return pbx_exec(chan, app, S_OR(s, ""));
-	} else {
-		ast_log(LOG_WARNING, "Cannot locate application %s\n", appname);
-		return -1;
-	}
+	return ast_pbx_exec_application(chan, appname, S_OR(s, ""));
 }
 
 /*!

res/res_stasis_snoop.c

@@ -263,14 +263,8 @@ static struct ast_channel_tech snoop_tech = {
 static void *snoop_stasis_thread(void *obj)
 {
 	RAII_VAR(struct stasis_app_snoop *, snoop, obj, ao2_cleanup);
-	struct ast_app *stasis = pbx_findapp("Stasis");
 
-	if (!stasis) {
-		ast_hangup(snoop->chan);
-		return NULL;
-	}
-
-	pbx_exec(snoop->chan, stasis, ast_str_buffer(snoop->app));
+	ast_pbx_exec_application(snoop->chan, "Stasis", ast_str_buffer(snoop->app));
 
 	ast_hangup(snoop->chan);