ubusd: add support for watching objects to get notified when they go away

[project/ubus.git] / libubus.c

diff --git a/libubus.c b/libubus.c
index 4502f24..590a0fa 100644 (file)
--- a/libubus.c
+++ b/libubus.c
@@ -709,7 +709,7 @@ static bool ubus_push_object_type(const struct ubus_object_type *type)
        return true;
 }
 
-static int __ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
+int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 {
        struct ubus_request req;
        int ret;
@@ -740,14 +740,6 @@ static int __ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
        return 0;
 }
 
-int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
-{
-       if (!obj->name || !obj->type)
-               return UBUS_STATUS_INVALID_ARGUMENT;
-
-       return __ubus_add_object(ctx, obj);
-}
-
 static void ubus_remove_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 {
        struct ubus_object *obj = req->priv;
@@ -819,7 +811,7 @@ int ubus_register_event_handler(struct ubus_context *ctx,
                if (!!obj->name ^ !!obj->type)
                        return UBUS_STATUS_INVALID_ARGUMENT;
 
-               ret = __ubus_add_object(ctx, obj);
+               ret = ubus_add_object(ctx, obj);
                if (ret)
                        return ret;
        }
@@ -835,6 +827,81 @@ int ubus_register_event_handler(struct ubus_context *ctx,
                          NULL, NULL, 0);
 }
 
+enum {
+       WATCH_ID,
+       WATCH_NOTIFY,
+       __WATCH_MAX
+};
+
+static const struct blobmsg_policy watch_policy[] = {
+       [WATCH_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
+       [WATCH_NOTIFY] = { .name = "notify", .type = BLOBMSG_TYPE_STRING },
+};
+
+
+static int ubus_watch_cb(struct ubus_context *ctx, struct ubus_object *obj,
+                        struct ubus_request_data *req,
+                        const char *method, struct blob_attr *msg)
+{
+       struct ubus_watch_object *w;
+       struct blob_attr *tb[__WATCH_MAX];
+
+       blobmsg_parse(watch_policy, ARRAY_SIZE(watch_policy), tb, blob_data(msg), blob_len(msg));
+
+       if (!tb[WATCH_ID] || !tb[WATCH_NOTIFY])
+               return UBUS_STATUS_INVALID_ARGUMENT;
+
+       if (req->peer)
+               return UBUS_STATUS_INVALID_ARGUMENT;
+
+       w = container_of(obj, struct ubus_watch_object, obj);
+       w->cb(ctx, w, blobmsg_get_u32(tb[WATCH_ID]));
+       return 0;
+}
+
+static const struct ubus_method watch_method = {
+       .name = NULL,
+       .handler = ubus_watch_cb,
+};
+
+int ubus_register_watch_object(struct ubus_context *ctx, struct ubus_watch_object *w_obj)
+{
+       struct ubus_object *obj = &w_obj->obj;
+
+       obj->methods = &watch_method;
+       obj->n_methods = 1;
+
+       return ubus_add_object(ctx, obj);
+}
+
+static int
+__ubus_watch_request(struct ubus_context *ctx, struct ubus_object *obj, uint32_t id, const char *method, int type)
+{
+       struct ubus_request req;
+
+       blob_buf_init(&b, 0);
+       blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
+       blob_put_int32(&b, UBUS_ATTR_TARGET, id);
+       if (method)
+               blob_put_string(&b, UBUS_ATTR_METHOD, method);
+
+       if (ubus_start_request(ctx, &req, b.head, type, 0) < 0)
+               return UBUS_STATUS_INVALID_ARGUMENT;
+
+       return ubus_complete_request(ctx, &req, 0);
+
+}
+
+int ubus_watch_object_add(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
+{
+       return __ubus_watch_request(ctx, &obj->obj, id, "event", UBUS_MSG_ADD_WATCH);
+}
+
+int ubus_watch_object_remove(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
+{
+       return __ubus_watch_request(ctx, &obj->obj, id, NULL, UBUS_MSG_REMOVE_WATCH);
+}
+
 int ubus_send_event(struct ubus_context *ctx, const char *id,
                    struct blob_attr *data)
 {