ARI: Add the ability to download the media associated with a stored recording

This patch adds a new feature to ARI that allows a client to download
the media associated with a stored recording. The new route is
/recordings/stored/{name}/file, and transmits the underlying binary file
using Asterisk's HTTP server's underlying file transfer facilities.

Because this REST route returns non-JSON, a few small enhancements had
to be made to the Python Swagger generation code, as well as the
mustache templates that generate the ARI bindings.

ASTERISK-26042 #close

Change-Id: I49ec5c4afdec30bb665d9c977ab423b5387e0181

CHANGES

@@ -32,6 +32,10 @@ ARI
    back to the resource. The "PlaybackFinished" event is raised when all media
    URIs are done.
 
+ * Stored recordings now allow for the media associated with a stored recording
+   to be retrieved. The new route, GET /recordings/stored/{name}/file, will
+   transmit the raw media file to the requester as binary.
+
 
 Applications
 ------------------

include/asterisk/ari.h

@@ -95,6 +95,8 @@ struct ast_ari_response {
 	/*! HTTP response code.
 	 * See http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html */
 	int response_code;
+	/*! File descriptor for whatever file we want to respond with */
+	int fd;
 	/*! Corresponding text for the response code */
 	const char *response_text; /* Shouldn't http.c handle this? */
 	/*! Flag to indicate that no further response is needed */

include/asterisk/stasis_app_recording.h

@@ -48,6 +48,30 @@ struct stasis_app_stored_recording;
 const char *stasis_app_stored_recording_get_file(
 	struct stasis_app_stored_recording *recording);
 
+/*!
+ * \brief Returns the full filename, with extension, for this recording.
+ * \since 14.0.0
+ *
+ * \param recording Recording to query.
+ *
+ * \return Absolute path to the recording file, with the extension.
+ * \return \c NULL on error
+ */
+const char *stasis_app_stored_recording_get_filename(
+	struct stasis_app_stored_recording *recording);
+
+/*!
+ * \brief Returns the extension for this recording.
+ * \since 14.0.0
+ *
+ * \param recording Recording to query.
+ *
+ * \return The extension associated with this recording.
+ * \return \c NULL on error
+ */
+const char *stasis_app_stored_recording_get_extension(
+	struct stasis_app_stored_recording *recording);
+
 /*!
  * \brief Convert stored recording info to JSON.
  *

res/ari/resource_recordings.c

@@ -101,6 +101,50 @@ void ast_ari_recordings_get_stored(struct ast_variable *headers,
 	ast_ari_response_ok(response, json);
 }
 
+void ast_ari_recordings_get_stored_file(struct ast_tcptls_session_instance *ser,
+	struct ast_variable *headers, struct ast_ari_recordings_get_stored_file_args *args,
+	struct ast_ari_response *response)
+{
+	RAII_VAR(struct stasis_app_stored_recording *, recording,
+		stasis_app_stored_recording_find_by_name(args->recording_name),
+		ao2_cleanup);
+	static const char *format_type_names[AST_MEDIA_TYPE_TEXT + 1] = {
+		[AST_MEDIA_TYPE_UNKNOWN] = "binary",
+		[AST_MEDIA_TYPE_AUDIO] = "audio",
+		[AST_MEDIA_TYPE_VIDEO] = "video",
+		[AST_MEDIA_TYPE_IMAGE] = "image",
+		[AST_MEDIA_TYPE_TEXT] = "text",
+	};
+	struct ast_format *format;
+
+	response->message = ast_json_null();
+
+	if (!recording) {
+		ast_ari_response_error(response, 404, "Not Found",
+			"Recording not found");
+		return;
+	}
+
+	format = ast_get_format_for_file_ext(stasis_app_stored_recording_get_extension(recording));
+	if (!format) {
+		ast_ari_response_error(response, 500, "Internal Server Error",
+			"Format specified by recording not available or loaded");
+		return;
+	}
+
+	response->fd = open(stasis_app_stored_recording_get_filename(recording), O_RDONLY);
+	if (response->fd < 0) {
+		ast_ari_response_error(response, 403, "Forbidden",
+			"Recording could not be opened");
+		return;
+	}
+
+	ast_str_append(&response->headers, 0, "Content-Type: %s/%s\r\n",
+		format_type_names[ast_format_get_type(format)],
+		stasis_app_stored_recording_get_extension(recording));
+	ast_ari_response_ok(response, ast_json_null());
+}
+
 void ast_ari_recordings_copy_stored(struct ast_variable *headers,
 	struct ast_ari_recordings_copy_stored_args *args,
 	struct ast_ari_response *response)

res/ari/resource_recordings.h

@@ -76,6 +76,20 @@ struct ast_ari_recordings_delete_stored_args {
  * \param[out] response HTTP response
  */
 void ast_ari_recordings_delete_stored(struct ast_variable *headers, struct ast_ari_recordings_delete_stored_args *args, struct ast_ari_response *response);
+/*! Argument struct for ast_ari_recordings_get_stored_file() */
+struct ast_ari_recordings_get_stored_file_args {
+	/*! The name of the recording */
+	const char *recording_name;
+};
+/*!
+ * \brief Get the file associated with the stored recording.
+ *
+ * \param ser TCP/TLS session instance
+ * \param headers HTTP headers
+ * \param args Swagger parameters
+ * \param[out] response HTTP response
+ */
+void ast_ari_recordings_get_stored_file(struct ast_tcptls_session_instance *ser, struct ast_variable *headers, struct ast_ari_recordings_get_stored_file_args *args, struct ast_ari_response *response);
 /*! Argument struct for ast_ari_recordings_copy_stored() */
 struct ast_ari_recordings_copy_stored_args {
 	/*! The name of the recording to copy */

res/res_ari.c

@@ -870,7 +870,7 @@ static int ast_ari_callback(struct ast_tcptls_session_instance *ser,
 	RAII_VAR(struct ast_ari_conf *, conf, NULL, ao2_cleanup);
 	RAII_VAR(struct ast_str *, response_body, ast_str_create(256), ast_free);
 	RAII_VAR(struct ast_ari_conf_user *, user, NULL, ao2_cleanup);
-	struct ast_ari_response response = {};
+	struct ast_ari_response response = { .fd = -1, 0 };
 	RAII_VAR(struct ast_variable *, post_vars, NULL, ast_variables_destroy);
 
 	if (!response_body) {
@@ -1011,11 +1011,14 @@ request_failed:
 		response.response_text, ast_str_buffer(response.headers), ast_str_buffer(response_body));
 	ast_http_send(ser, method, response.response_code,
 		      response.response_text, response.headers, response_body,
-		      0, 0);
+		      response.fd != -1 ? response.fd : 0, 0);
 	/* ast_http_send takes ownership, so we don't have to free them */
 	response_body = NULL;
 
 	ast_json_unref(response.message);
+	if (response.fd >= 0) {
+		close(response.fd);
+	}
 	return 0;
 }
 
@@ -1023,7 +1026,6 @@ static struct ast_http_uri http_uri = {
 	.callback = ast_ari_callback,
 	.description = "Asterisk RESTful API",
 	.uri = "ari",
-
 	.has_subtree = 1,
 	.data = NULL,
 	.key = __FILE__,

res/res_ari_recordings.c

@@ -218,6 +218,65 @@ static void ast_ari_recordings_delete_stored_cb(
 	}
 #endif /* AST_DEVMODE */
 
+fin: __attribute__((unused))
+	return;
+}
+/*!
+ * \brief Parameter parsing callback for /recordings/stored/{recordingName}/file.
+ * \param get_params GET parameters in the HTTP request.
+ * \param path_vars Path variables extracted from the request.
+ * \param headers HTTP headers.
+ * \param[out] response Response to the HTTP request.
+ */
+static void ast_ari_recordings_get_stored_file_cb(
+	struct ast_tcptls_session_instance *ser,
+	struct ast_variable *get_params, struct ast_variable *path_vars,
+	struct ast_variable *headers, struct ast_ari_response *response)
+{
+	struct ast_ari_recordings_get_stored_file_args args = {};
+	struct ast_variable *i;
+	RAII_VAR(struct ast_json *, body, NULL, ast_json_unref);
+#if defined(AST_DEVMODE)
+	int is_valid;
+	int code;
+#endif /* AST_DEVMODE */
+
+	for (i = path_vars; i; i = i->next) {
+		if (strcmp(i->name, "recordingName") == 0) {
+			args.recording_name = (i->value);
+		} else
+		{}
+	}
+	ast_ari_recordings_get_stored_file(ser, headers, &args, response);
+#if defined(AST_DEVMODE)
+	code = response->response_code;
+
+	switch (code) {
+	case 0: /* Implementation is still a stub, or the code wasn't set */
+		is_valid = response->message == NULL;
+		break;
+	case 500: /* Internal Server Error */
+	case 501: /* Not Implemented */
+	case 404: /* Recording not found */
+		is_valid = 1;
+		break;
+	default:
+		if (200 <= code && code <= 299) {
+			/* No validation on a raw binary response */
+			is_valid = 1;
+		} else {
+			ast_log(LOG_ERROR, "Invalid error response %d for /recordings/stored/{recordingName}/file\n", code);
+			is_valid = 0;
+		}
+	}
+
+	if (!is_valid) {
+		ast_log(LOG_ERROR, "Response validation failed for /recordings/stored/{recordingName}/file\n");
+		ast_ari_response_error(response, 500,
+			"Internal Server Error", "Response validation failed");
+	}
+#endif /* AST_DEVMODE */
+
 fin: __attribute__((unused))
 	return;
 }
@@ -737,6 +796,15 @@ fin: __attribute__((unused))
 	return;
 }
 
+/*! \brief REST handler for /api-docs/recordings.{format} */
+static struct stasis_rest_handlers recordings_stored_recordingName_file = {
+	.path_segment = "file",
+	.callbacks = {
+		[AST_HTTP_GET] = ast_ari_recordings_get_stored_file_cb,
+	},
+	.num_children = 0,
+	.children = {  }
+};
 /*! \brief REST handler for /api-docs/recordings.{format} */
 static struct stasis_rest_handlers recordings_stored_recordingName_copy = {
 	.path_segment = "copy",
@@ -754,8 +822,8 @@ static struct stasis_rest_handlers recordings_stored_recordingName = {
 		[AST_HTTP_GET] = ast_ari_recordings_get_stored_cb,
 		[AST_HTTP_DELETE] = ast_ari_recordings_delete_stored_cb,
 	},
-	.num_children = 1,
-	.children = { &recordings_stored_recordingName_copy, }
+	.num_children = 2,
+	.children = { &recordings_stored_recordingName_file,&recordings_stored_recordingName_copy, }
 };
 /*! \brief REST handler for /api-docs/recordings.{format} */
 static struct stasis_rest_handlers recordings_stored = {

res/stasis_recording/stored.c

@@ -62,6 +62,24 @@ const char *stasis_app_stored_recording_get_file(
 	return recording->file;
 }
 
+const char *stasis_app_stored_recording_get_filename(
+	struct stasis_app_stored_recording *recording)
+{
+	if (!recording) {
+		return NULL;
+	}
+	return recording->file_with_ext;
+}
+
+const char *stasis_app_stored_recording_get_extension(
+	struct stasis_app_stored_recording *recording)
+{
+	if (!recording) {
+		return NULL;
+	}
+	return recording->format;
+}
+
 /*!
  * \brief Split a path into directory and file, resolving canonical directory.
  *

rest-api-templates/ari_resource.h.mustache

@@ -82,11 +82,19 @@ int ast_ari_{{c_name}}_{{c_nickname}}_parse_body(
  * {{{notes}}}
 {{/notes}}
  *
+{{#is_binary_response}}
+ * \param ser TCP/TLS session instance
+{{/is_binary_response}}
  * \param headers HTTP headers
  * \param args Swagger parameters
  * \param[out] response HTTP response
  */
+{{^is_binary_response}}
 void ast_ari_{{c_name}}_{{c_nickname}}(struct ast_variable *headers, struct ast_ari_{{c_name}}_{{c_nickname}}_args *args, struct ast_ari_response *response);
+{{/is_binary_response}}
+{{#is_binary_response}}
+void ast_ari_{{c_name}}_{{c_nickname}}(struct ast_tcptls_session_instance *ser, struct ast_variable *headers, struct ast_ari_{{c_name}}_{{c_nickname}}_args *args, struct ast_ari_response *response);
+{{/is_binary_response}}
 {{/is_req}}
 {{#is_websocket}}
 

rest-api-templates/res_ari_resource.c.mustache

@@ -91,7 +91,12 @@ static void ast_ari_{{c_name}}_{{c_nickname}}_cb(
 #endif /* AST_DEVMODE */
 
 {{> param_parsing}}
+{{^is_binary_response}}
 	ast_ari_{{c_name}}_{{c_nickname}}(headers, &args, response);
+{{/is_binary_response}}
+{{#is_binary_response}}
+	ast_ari_{{c_name}}_{{c_nickname}}(ser, headers, &args, response);
+{{/is_binary_response}}
 #if defined(AST_DEVMODE)
 	code = response->response_code;
 
@@ -114,8 +119,14 @@ static void ast_ari_{{c_name}}_{{c_nickname}}_cb(
 				ast_ari_validate_{{c_singular_name}}_fn());
 {{/is_list}}
 {{^is_list}}
+{{^is_binary_response}}
 			is_valid = ast_ari_validate_{{c_name}}(
 				response->message);
+{{/is_binary_response}}
+{{#is_binary_response}}
+			/* No validation on a raw binary response */
+			is_valid = 1;
+{{/is_binary_response}}
 {{/is_list}}
 {{/response_class}}
 		} else {

rest-api-templates/swagger_model.py

@@ -332,6 +332,7 @@ class SwaggerType(Stringify):
         self.is_list = None
         self.singular_name = None
         self.is_primitive = None
+        self.is_binary = None
 
     def load(self, type_name, processor, context):
         # Some common errors
@@ -346,6 +347,7 @@ class SwaggerType(Stringify):
         else:
             self.singular_name = self.name
         self.is_primitive = self.singular_name in SWAGGER_PRIMITIVES
+        self.is_binary = (self.singular_name == 'binary')
         processor.process_type(self, context)
         return self
 
@@ -401,6 +403,7 @@ class Operation(Stringify):
         self.has_header_parameters = self.header_parameters and True
         self.has_parameters = self.has_query_parameters or \
             self.has_path_parameters or self.has_header_parameters
+        self.is_binary_response = self.response_class.is_binary
 
         # Body param is different, since there's at most one
         self.body_parameter = [

rest-api/api-docs/recordings.json

@@ -69,6 +69,38 @@
 				}
 			]
 		},
+		{
+			"path": "/recordings/stored/{recordingName}/file",
+			"description": "The actual file associated with the stored recording",
+			"operations": [
+				{
+					"httpMethod": "GET",
+					"summary": "Get the file associated with the stored recording.",
+					"nickname": "getStoredFile",
+					"responseClass": "binary",
+					"parameters": [
+						{
+							"name": "recordingName",
+							"description": "The name of the recording",
+							"paramType": "path",
+							"required": true,
+							"allowMultiple": false,
+							"dataType": "string"
+						}
+					],
+					"errorResponses": [
+						{
+							"code": 403,
+							"reason": "The recording file could not be opened"
+						},
+						{
+							"code": 404,
+							"reason": "Recording not found"
+						}
+					]
+				}
+			]
+		},
 		{
 			"path": "/recordings/stored/{recordingName}/copy",
 			"description": "Copy an individual recording",