ARI: Add method to create a new channel.

This adds a new ARI method to the channels resource that allows for the
creation of a new channel. The channel is created and then placed into
the specified Stasis application.

This is different from the existing originate method that creates a
channel, dials it, and then places the answered channel into the
dialplan or a Stasis application. This method does not attempt to call
the channel at all. Dialing is left as a later step after channel
creation. This allows for pre-dialing channel manipulation if desired.

ASTERISK-25889

Change-Id: I3c96a0aba914b08e39f6256371a5bd4c92cbded8

CHANGES

@@ -12,6 +12,14 @@
 --- Functionality changes from Asterisk 13 to Asterisk 14 --------------------
 ------------------------------------------------------------------------------
 
+ARI
+-----------------
+ * A new ARI method has been added to the channels resource. "create" allows for
+ you to create a new channel and place that channel into a Stasis application. This
+ is similar to origination except that the specified channel is not dialed. This
+ allows for an application writer to create a channel, perform manipulations on it,
+ and then delay dialing the channel until later.
+
 Applications
 ------------------
 

res/ari/resource_channels.c

@@ -1461,3 +1461,112 @@ void ast_ari_channels_snoop_channel_with_id(struct ast_variable *headers,
 		args->snoop_id,
 		response);
 }
+
+struct ari_channel_thread_data {
+	struct ast_channel *chan;
+	struct ast_str *stasis_stuff;
+};
+
+static void chan_data_destroy(struct ari_channel_thread_data *chan_data)
+{
+	ast_free(chan_data->stasis_stuff);
+	ast_hangup(chan_data->chan);
+	ast_free(chan_data);
+}
+
+/*!
+ * \brief Thread that owns stasis-created channel.
+ *
+ * The channel enters into a Stasis application immediately upon creation. In this
+ * way, the channel can be manipulated by the Stasis application. Once the channel
+ * exits the Stasis application, it is hung up.
+ */
+static void *ari_channel_thread(void *data)
+{
+	struct ari_channel_thread_data *chan_data = data;
+	struct ast_app *stasis_app;
+
+	stasis_app = pbx_findapp("Stasis");
+	if (!stasis_app) {
+		ast_log(LOG_ERROR, "Stasis dialplan application is not registered");
+		chan_data_destroy(chan_data);
+		return NULL;
+	}
+
+	pbx_exec(chan_data->chan, stasis_app, ast_str_buffer(chan_data->stasis_stuff));
+
+	chan_data_destroy(chan_data);
+
+	return NULL;
+}
+
+void ast_ari_channels_create(struct ast_variable *headers,
+	struct ast_ari_channels_create_args *args,
+	struct ast_ari_response *response)
+{
+	struct ast_assigned_ids assignedids = {
+		.uniqueid = args->channel_id,
+		.uniqueid2 = args->other_channel_id,
+	};
+	struct ari_channel_thread_data *chan_data;
+	struct ast_channel_snapshot *snapshot;
+	pthread_t thread;
+	char *dialtech;
+	char dialdevice[AST_CHANNEL_NAME];
+	char *stuff;
+	int cause;
+	struct ast_format_cap *request_cap;
+	struct ast_channel *originator;
+
+	chan_data = ast_calloc(1, sizeof(*chan_data));
+	if (!chan_data) {
+		ast_ari_response_alloc_failed(response);
+		return;
+	}
+
+	chan_data->stasis_stuff = ast_str_create(32);
+	if (!chan_data->stasis_stuff) {
+		ast_ari_response_alloc_failed(response);
+		chan_data_destroy(chan_data);
+		return;
+	}
+
+	ast_str_append(&chan_data->stasis_stuff, 0, "%s", args->app);
+	if (!ast_strlen_zero(args->app_args)) {
+		ast_str_append(&chan_data->stasis_stuff, 0, ",%s", args->app_args);
+	}
+
+	dialtech = ast_strdupa(args->endpoint);
+	if ((stuff = strchr(dialtech, '/'))) {
+		*stuff++ = '\0';
+		ast_copy_string(dialdevice, stuff, sizeof(dialdevice));
+	}
+
+	originator = ast_channel_get_by_name(args->originator);
+	if (originator) {
+		request_cap = ao2_bump(ast_channel_nativeformats(originator));
+	} else {
+		request_cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+		ast_format_cap_append_by_type(request_cap, AST_MEDIA_TYPE_AUDIO);
+	}
+
+	chan_data->chan = ast_request(dialtech, request_cap, &assignedids, originator, dialdevice, &cause);
+	ao2_cleanup(request_cap);
+	ast_channel_cleanup(originator);
+	if (!chan_data->chan) {
+		ast_ari_response_alloc_failed(response);
+		chan_data_destroy(chan_data);
+		return;
+	}
+
+	snapshot = ast_channel_snapshot_get_latest(ast_channel_uniqueid(chan_data->chan));
+
+	if (ast_pthread_create_detached(&thread, NULL, ari_channel_thread, chan_data)) {
+		ast_ari_response_alloc_failed(response);
+		chan_data_destroy(chan_data);
+	} else {
+		ast_ari_response_ok(response, ast_channel_snapshot_to_json(snapshot, NULL));
+	}
+
+	ao2_ref(snapshot, -1);
+}

res/ari/resource_channels.h

@@ -100,6 +100,40 @@ int ast_ari_channels_originate_parse_body(
  * \param[out] response HTTP response
  */
 void ast_ari_channels_originate(struct ast_variable *headers, struct ast_ari_channels_originate_args *args, struct ast_ari_response *response);
+/*! Argument struct for ast_ari_channels_create() */
+struct ast_ari_channels_create_args {
+	/*! Endpoint for channel communication */
+	const char *endpoint;
+	/*! Stasis Application to place channel into */
+	const char *app;
+	/*! The application arguments to pass to the Stasis application provided by 'app'. Mutually exclusive with 'context', 'extension', 'priority', and 'label'. */
+	const char *app_args;
+	/*! The unique id to assign the channel on creation. */
+	const char *channel_id;
+	/*! The unique id to assign the second channel when using local channels. */
+	const char *other_channel_id;
+	/*! Unique ID of the calling channel */
+	const char *originator;
+};
+/*!
+ * \brief Body parsing function for /channels/create.
+ * \param body The JSON body from which to parse parameters.
+ * \param[out] args The args structure to parse into.
+ * \retval zero on success
+ * \retval non-zero on failure
+ */
+int ast_ari_channels_create_parse_body(
+	struct ast_json *body,
+	struct ast_ari_channels_create_args *args);
+
+/*!
+ * \brief Create channel.
+ *
+ * \param headers HTTP headers
+ * \param args Swagger parameters
+ * \param[out] response HTTP response
+ */
+void ast_ari_channels_create(struct ast_variable *headers, struct ast_ari_channels_create_args *args, struct ast_ari_response *response);
 /*! Argument struct for ast_ari_channels_get() */
 struct ast_ari_channels_get_args {
 	/*! Channel's id */

res/res_ari_channels.c

@@ -265,6 +265,131 @@ static void ast_ari_channels_originate_cb(
 	}
 #endif /* AST_DEVMODE */
 
+fin: __attribute__((unused))
+	return;
+}
+int ast_ari_channels_create_parse_body(
+	struct ast_json *body,
+	struct ast_ari_channels_create_args *args)
+{
+	struct ast_json *field;
+	/* Parse query parameters out of it */
+	field = ast_json_object_get(body, "endpoint");
+	if (field) {
+		args->endpoint = ast_json_string_get(field);
+	}
+	field = ast_json_object_get(body, "app");
+	if (field) {
+		args->app = ast_json_string_get(field);
+	}
+	field = ast_json_object_get(body, "appArgs");
+	if (field) {
+		args->app_args = ast_json_string_get(field);
+	}
+	field = ast_json_object_get(body, "channelId");
+	if (field) {
+		args->channel_id = ast_json_string_get(field);
+	}
+	field = ast_json_object_get(body, "otherChannelId");
+	if (field) {
+		args->other_channel_id = ast_json_string_get(field);
+	}
+	field = ast_json_object_get(body, "originator");
+	if (field) {
+		args->originator = ast_json_string_get(field);
+	}
+	return 0;
+}
+
+/*!
+ * \brief Parameter parsing callback for /channels/create.
+ * \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_channels_create_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_channels_create_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 = get_params; i; i = i->next) {
+		if (strcmp(i->name, "endpoint") == 0) {
+			args.endpoint = (i->value);
+		} else
+		if (strcmp(i->name, "app") == 0) {
+			args.app = (i->value);
+		} else
+		if (strcmp(i->name, "appArgs") == 0) {
+			args.app_args = (i->value);
+		} else
+		if (strcmp(i->name, "channelId") == 0) {
+			args.channel_id = (i->value);
+		} else
+		if (strcmp(i->name, "otherChannelId") == 0) {
+			args.other_channel_id = (i->value);
+		} else
+		if (strcmp(i->name, "originator") == 0) {
+			args.originator = (i->value);
+		} else
+		{}
+	}
+	/* Look for a JSON request entity */
+	body = ast_http_get_json(ser, headers);
+	if (!body) {
+		switch (errno) {
+		case EFBIG:
+			ast_ari_response_error(response, 413, "Request Entity Too Large", "Request body too large");
+			goto fin;
+		case ENOMEM:
+			ast_ari_response_error(response, 500, "Internal Server Error", "Error processing request");
+			goto fin;
+		case EIO:
+			ast_ari_response_error(response, 400, "Bad Request", "Error parsing request body");
+			goto fin;
+		}
+	}
+	if (ast_ari_channels_create_parse_body(body, &args)) {
+		ast_ari_response_alloc_failed(response);
+		goto fin;
+	}
+	ast_ari_channels_create(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 */
+		is_valid = 1;
+		break;
+	default:
+		if (200 <= code && code <= 299) {
+			is_valid = ast_ari_validate_channel(
+				response->message);
+		} else {
+			ast_log(LOG_ERROR, "Invalid error response %d for /channels/create\n", code);
+			is_valid = 0;
+		}
+	}
+
+	if (!is_valid) {
+		ast_log(LOG_ERROR, "Response validation failed for /channels/create\n");
+		ast_ari_response_error(response, 500,
+			"Internal Server Error", "Response validation failed");
+	}
+#endif /* AST_DEVMODE */
+
 fin: __attribute__((unused))
 	return;
 }
@@ -2553,6 +2678,15 @@ fin: __attribute__((unused))
 	return;
 }
 
+/*! \brief REST handler for /api-docs/channels.{format} */
+static struct stasis_rest_handlers channels_create = {
+	.path_segment = "create",
+	.callbacks = {
+		[AST_HTTP_POST] = ast_ari_channels_create_cb,
+	},
+	.num_children = 0,
+	.children = {  }
+};
 /*! \brief REST handler for /api-docs/channels.{format} */
 static struct stasis_rest_handlers channels_channelId_continue = {
 	.path_segment = "continue",
@@ -2715,8 +2849,8 @@ static struct stasis_rest_handlers channels = {
 		[AST_HTTP_GET] = ast_ari_channels_list_cb,
 		[AST_HTTP_POST] = ast_ari_channels_originate_cb,
 	},
-	.num_children = 1,
-	.children = { &channels_channelId, }
+	.num_children = 2,
+	.children = { &channels_create,&channels_channelId, }
 };
 
 static int load_module(void)

rest-api/api-docs/channels.json

@@ -139,6 +139,68 @@
 				}
 			]
 		},
+		{
+			"path": "/channels/create",
+			"description": "Create a channel and place it in a Stasis app, but do not dial the channel yet.",
+			"operations": [
+				{
+					"httpMethod": "POST",
+					"summary": "Create channel.",
+					"nickname": "create",
+					"responseClass": "Channel",
+					"parameters": [
+						{
+							"name": "endpoint",
+							"description": "Endpoint for channel communication",
+							"paramType": "query",
+							"required": true,
+							"allowMultiple": false,
+							"dataType": "string"
+						},
+						{
+							"name": "app",
+							"description": "Stasis Application to place channel into",
+							"paramType": "query",
+							"required": true,
+							"allowMultiple": false,
+							"dataType": "string"
+						},
+						{
+							"name": "appArgs",
+							"description": "The application arguments to pass to the Stasis application provided by 'app'. Mutually exclusive with 'context', 'extension', 'priority', and 'label'.",
+							"paramType": "query",
+							"required": false,
+							"allowMultiple": false,
+							"dataType": "string"
+						},
+						{
+							"name": "channelId",
+							"description": "The unique id to assign the channel on creation.",
+							"paramType": "query",
+							"required": false,
+							"allowMultiple": false,
+							"dataType": "string"
+						},
+						{
+							"name": "otherChannelId",
+							"description": "The unique id to assign the second channel when using local channels.",
+							"paramType": "query",
+							"required": false,
+							"allowMultiple": false,
+							"dataType": "string"
+						},
+						{
+							"name": "originator",
+							"description": "Unique ID of the calling channel",
+							"paramType": "query",
+							"required": false,
+							"allowMultiple": false,
+							"dataType": "string"
+						}
+					]
+				}
+			]
+		},
 		{
 			"path": "/channels/{channelId}",
 			"description": "Active channel",