add support for attaching arbitrary state data to interfaces

3 files changed, 77 insertions, 1 deletions

diff --git a/interface.c b/interface.c
index 902f55b..c5addea 100644
--- a/interface.c
+++ b/interface.c
@@ -81,6 +81,42 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 }
 
 static void
+interface_data_del(struct interface *iface, struct interface_data *data)
+{
+	avl_delete(&iface->data, &data->node);
+	free(data);
+}
+
+static void
+interface_data_flush(struct interface *iface)
+{
+	struct interface_data *d, *tmp;
+
+	avl_for_each_element_safe(&iface->data, d, node, tmp)
+		interface_data_del(iface, d);
+}
+
+int
+interface_add_data(struct interface *iface, const struct blob_attr *data)
+{
+	struct interface_data *n, *o;
+
+	if (!blobmsg_check_attr(data, true))
+		return UBUS_STATUS_INVALID_ARGUMENT;
+
+	n = calloc(1, sizeof(*data) + blob_pad_len(data));
+	memcpy(n->data, data, blob_pad_len(data));
+	n->node.key = blobmsg_name(data);
+
+	o = avl_find_element(&iface->data, n->node.key, o, node);
+	if (o)
+		interface_data_del(iface, o);
+
+	avl_insert(&iface->data, &n->node);
+	return 0;
+}
+
+static void
 interface_event(struct interface *iface, enum interface_event ev)
 {
 	struct interface_user *dep, *tmp;
@@ -98,6 +134,7 @@ interface_flush_state(struct interface *iface)
 		device_release(&iface->main_dev);
 	if (iface->l3_dev.dev)
 		device_release(&iface->l3_dev);
+	interface_data_flush(iface);
 }
 
 static void
@@ -318,6 +355,7 @@ interface_init(struct interface *iface, const char *name,
 	INIT_LIST_HEAD(&iface->hotplug_list);
 	interface_ip_init(&iface->proto_ip, iface);
 	interface_ip_init(&iface->config_ip, iface);
+	avl_init(&iface->data, avl_strcmp, false, NULL);
 	iface->config_ip.enabled = false;
 
 	iface->main_dev.cb = interface_cb;
diff --git a/interface.h b/interface.h
index b2ecd23..5e3f383 100644
--- a/interface.h
+++ b/interface.h
@@ -51,6 +51,11 @@ struct interface_ip_settings {
 	struct vlist_simple_tree dns_search;
 };
 
+struct interface_data {
+	struct avl_node node;
+	struct blob_attr data[];
+};
+
 /*
  * interface configuration
  */
@@ -92,6 +97,9 @@ struct interface {
 	/* errors/warnings while trying to bring up the interface */
 	struct list_head errors;
 
+	/* extra data provided by protocol handlers or modules */
+	struct avl_tree data;
+
 	struct uloop_timeout remove_timer;
 	struct ubus_object ubus;
 };
@@ -123,6 +131,8 @@ int interface_remove_link(struct interface *iface, struct device *dev);
 void interface_add_error(struct interface *iface, const char *subsystem,
 			 const char *code, const char **data, int n_data);
 
+int interface_add_data(struct interface *iface, const struct blob_attr *data);
+
 void interface_update_start(struct interface *iface);
 void interface_update_complete(struct interface *iface);
 
diff --git a/ubus.c b/ubus.c
index 40c6374..b01d6ad 100644
--- a/ubus.c
+++ b/ubus.c
@@ -289,6 +289,7 @@ netifd_handle_status(struct ubus_context *ctx, struct ubus_object *obj,
 		     struct blob_attr *msg)
 {
 	struct interface *iface;
+	struct interface_data *data;
 	struct device *dev;
 	void *a;
 
@@ -321,6 +322,12 @@ netifd_handle_status(struct ubus_context *ctx, struct ubus_object *obj,
 		blobmsg_close_array(&b, a);
 	}
 
+	a = blobmsg_open_table(&b, "data");
+	avl_for_each_element(&iface->data, data, node)
+		blob_put(&b, blob_id(data->data), blob_data(data->data), blob_len(data->data));
+
+	blobmsg_close_table(&b, a);
+
 	if (!list_is_empty(&iface->errors))
 		netifd_add_interface_errors(&b, iface);
 
@@ -425,6 +432,26 @@ netifd_handle_iface_prepare(struct ubus_context *ctx, struct ubus_object *obj,
 	return ops->prepare(dev);
 }
 
+static int
+netifd_handle_set_data(struct ubus_context *ctx, struct ubus_object *obj,
+		       struct ubus_request_data *req, const char *method,
+		       struct blob_attr *msg)
+{
+	struct interface *iface;
+	struct blob_attr *cur;
+	int rem, ret;
+
+	iface = container_of(obj, struct interface, ubus);
+
+	blob_for_each_attr(cur, msg, rem) {
+		ret = interface_add_data(iface, cur);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static struct ubus_method iface_object_methods[] = {
 	{ .name = "up", .handler = netifd_handle_up },
 	{ .name = "down", .handler = netifd_handle_down },
@@ -433,7 +460,8 @@ static struct ubus_method iface_object_methods[] = {
 	UBUS_METHOD("add_device", netifd_iface_handle_device, dev_policy ),
 	UBUS_METHOD("remove_device", netifd_iface_handle_device, dev_policy ),
 	{ .name = "notify_proto", .handler = netifd_iface_notify_proto },
-	{ .name = "remove", .handler = netifd_iface_remove }
+	{ .name = "remove", .handler = netifd_iface_remove },
+	{ .name = "set_data", .handler = netifd_handle_set_data },
 };
 
 static struct ubus_object_type iface_object_type =