+list_node_t *list_insert_before(list_t *list, list_node_t *before, void *data) {
+ list_node_t *node;
+
+ node = list_alloc_node();
+
+ node->data = data;
+ node->next = before;
+ node->prev = before->prev;
+ before->prev = node;
+
+ if(node->prev)
+ node->prev->next = node;
+ else
+ list->head = node;
+
+ list->count++;
+
+ return node;
+}
+