ubus/ubus-example.c

/*
 * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <unistd.h>

#include "libubus.h"

static struct ubus_context *ctx;
static struct ubus_watch_object test_event;
struct blob_buf b;

enum {
	HELLO_ID,
	HELLO_MSG,
	__HELLO_MAX
};

static const struct blobmsg_policy hello_policy[] = {
	[HELLO_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
	[HELLO_MSG] = { .name = "msg", .type = BLOBMSG_TYPE_STRING },
};

static int test_hello(struct ubus_context *ctx, struct ubus_object *obj,
		      struct ubus_request_data *req, const char *method,
		      struct blob_attr *msg)
{
	struct blob_attr *tb[__HELLO_MAX];
	char *msgstr = "(unknown)";
	char *strbuf;

	blobmsg_parse(hello_policy, ARRAY_SIZE(hello_policy), tb, blob_data(msg), blob_len(msg));

	if (tb[HELLO_MSG])
		msgstr = blobmsg_data(tb[HELLO_MSG]);

	blob_buf_init(&b, 0);
	strbuf = blobmsg_alloc_string_buffer(&b, "message", 64 + strlen(obj->name) + strlen(msgstr));
	sprintf(strbuf, "%s received a message: %s", obj->name, msgstr);
	blobmsg_add_string_buffer(&b);
	ubus_send_reply(ctx, req, b.head);
	return 0;
}

enum {
	WATCH_ID,
	__WATCH_MAX
};

static const struct blobmsg_policy watch_policy[__WATCH_MAX] = {
	[WATCH_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
};

static void test_handle_event(struct ubus_context *ctx, struct ubus_watch_object *w,
                       uint32_t id)
{
	fprintf(stderr, "Object %08x went away\n", id);
}

static int test_watch(struct ubus_context *ctx, struct ubus_object *obj,
		      struct ubus_request_data *req, const char *method,
		      struct blob_attr *msg)
{
	struct blob_attr *tb[__WATCH_MAX];
	int ret;

	blobmsg_parse(watch_policy, __WATCH_MAX, tb, blob_data(msg), blob_len(msg));
	if (!tb[WATCH_ID])
		return UBUS_STATUS_INVALID_ARGUMENT;

	test_event.cb = test_handle_event;
	ret = ubus_watch_object_add(ctx, &test_event, blobmsg_get_u32(tb[WATCH_ID]));
	fprintf(stderr, "Watching object %08x: %s\n", blobmsg_get_u32(tb[WATCH_ID]), ubus_strerror(ret));
	return ret;
}

static const struct ubus_method test_methods[] = {
	UBUS_METHOD("hello", test_hello, hello_policy),
	UBUS_METHOD("watch", test_watch, watch_policy),
};

static struct ubus_object_type test_object_type =
	UBUS_OBJECT_TYPE("test", test_methods);

static struct ubus_object test_object = {
	.name = "test",
	.type = &test_object_type,
	.methods = test_methods,
	.n_methods = ARRAY_SIZE(test_methods),
};

static struct ubus_object test_client_object = {
	.type = &test_object_type,
	.methods = test_methods,
	.n_methods = ARRAY_SIZE(test_methods),
};

static void server_main(void)
{
	int ret;

	ret = ubus_add_object(ctx, &test_object);
	if (ret)
		fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));

	ret = ubus_register_watch_object(ctx, &test_event);
	if (ret)
		fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));

	uloop_run();
}

static void client_main(void)
{
	uint32_t id;
	int ret;

	ret = ubus_add_object(ctx, &test_client_object);
	if (ret) {
		fprintf(stderr, "Failed to add_object object: %s\n", ubus_strerror(ret));
		return;
	}

	if (ubus_lookup_id(ctx, test_object.name, &id)) {
		fprintf(stderr, "Failed to look up test object\n");
		return;
	}

	blob_buf_init(&b, 0);
	blobmsg_add_u32(&b, "id", test_client_object.id);
	ubus_invoke(ctx, id, "watch", b.head, NULL, 0, 3000);
	uloop_run();
}

int main(int argc, char **argv)
{
	const char *ubus_socket = NULL;
	bool client = false;
	int ch;

	while ((ch = getopt(argc, argv, "cs:")) != -1) {
		switch (ch) {
		case 's':
			ubus_socket = optarg;
			break;
		case 'c':
			client = true;
			break;
		default:
			break;
		}
	}

	argc -= optind;
	argv += optind;

	uloop_init();

	ctx = ubus_connect(ubus_socket);
	if (!ctx) {
		fprintf(stderr, "Failed to connect to ubus\n");
		return -1;
	}

	ubus_add_uloop(ctx);

	if (client)
		client_main();
	else
		server_main();

	ubus_free(ctx);
	uloop_done();

	return 0;
}