subscribe_ubus.c

#include <libubox/blobmsg_json.h>
#include <libubus.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


#define TOPIC_NAME "topology.connection"
#define UBUS_SOCKET "/var/run/ubus.sock"
/**
 * Global ubus context
 */
static struct ubus_context *ctx;

/**
 * Handle event messages from ubus
 *
 * @param ctx     Ubus context
 * @param obj     Ubus object
 * @param req     Request data
 * @param method  Method name
 * @param msg     Message blob
 * @return 0 on success
 */
static int handle_receive_event(struct ubus_context *ctx, struct ubus_object *obj,
                                struct ubus_request_data *req, const char *method,
                                struct blob_attr *msg) {
    char *json_str = blobmsg_format_json(msg, true);
    
    if (json_str) {
        printf("Received event: %s\n", json_str);
        free(json_str);
    } else {
        printf("Failed to parse received event.\n");
    }
    
    return 0;
}

/**
 * Ubus method definition
 */
static const struct ubus_method receive_methods[] = {
    UBUS_METHOD_NOARG("push_event", handle_receive_event),
};

/**
 * Ubus object type definition
 */
static struct ubus_object_type receive_object_type =
    UBUS_OBJECT_TYPE("push_event", receive_methods);

/**
 * Ubus object definition
 */
static struct ubus_object receive_object = {
    .name = TOPIC_NAME,
    .type = &receive_object_type,
    .methods = receive_methods,
    .n_methods = ARRAY_SIZE(receive_methods),
};

/**
 * Initialize ubus connection
 *
 * @param ubus_socket Path to ubus socket
 * @return 0 on success, -1 on failure
 */
static int init_ubus(const char *ubus_socket) {
    ctx = ubus_connect(ubus_socket);
    if (!ctx) {
        fprintf(stderr, "Failed to connect to UBUS at %s\n", ubus_socket);
        return -1;
    }
    
    printf("Connected to UBUS at %s\n", ubus_socket);
    
    if (ubus_add_object(ctx, &receive_object)) {
        fprintf(stderr, "Failed to add UBUS object.\n");
        ubus_free(ctx);
        return -1;
    }
    
    printf("UBUS object registered successfully.\n");
    return 0;
}

/**
 * Cleanup ubus resources
 */
static void cleanup_ubus(void) {
    if (ctx) {
        ubus_free(ctx);
        printf("Disconnected from UBUS\n");
    }
}

int main(int argc, char **argv) {
    int ret = EXIT_SUCCESS;

    /* Initialize ubus connection */
    if (init_ubus(UBUS_SOCKET) < 0) {
        return EXIT_FAILURE;
    }

    /* Start event loop */
    uloop_init();
    ubus_add_uloop(ctx);
    uloop_run();

    /* Cleanup */
    cleanup_ubus();
    uloop_done();

    return ret;
}