func_uuid: Add a new dialplan function to generate UUIDs

This function is useful for uniquely identifying calls, recordings, and other entities in distributed environments, as well as for generating an argument for the AudioSocket application.

(cherry picked from commit ba01e712da)

funcs/func_uuid.c

@@ -0,0 +1,76 @@
+/*
+* Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2024, Maksim Nesterov
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief UUID dialplan function
+ *
+ * \author Maksim Nesterov <braamsdev@gmail.com>
+ *
+ * \ingroup functions
+ */
+
+/*** MODULEINFO
+	<support_level>extended</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include "asterisk/module.h"
+#include "asterisk/pbx.h"
+#include "asterisk/uuid.h"
+
+/*** DOCUMENTATION
+	<function name="UUID" language="en_US">
+		<synopsis>
+			Generates an UUID.
+		</synopsis>
+		<syntax>
+		</syntax>
+		<description>
+			<para>Returns a version 4 (random) Universally Unique Identifier (UUID) as a string.</para>
+			<example title="Generate an UUID">
+			same => n,Set(uuid=${UUID()})
+			</example>
+		</description>
+	</function>
+ ***/
+
+static int uuid(struct ast_channel *chan, const char *cmd, char *data,
+				char *buf, size_t len)
+{
+	ast_uuid_generate_str(buf, AST_UUID_STR_LEN);
+	return 0;
+}
+
+static struct ast_custom_function uuid_function = {
+	.name = "UUID",
+	.read = uuid,
+	.read_max = AST_UUID_STR_LEN,
+};
+
+static int unload_module(void)
+{
+	return ast_custom_function_unregister(&uuid_function);
+}
+
+static int load_module(void)
+{
+	return ast_custom_function_register(&uuid_function);
+}
+
+AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY,
+								  "UUID generation dialplan function");