diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4b6defc..eb112af 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ IF(APPLE)
   LINK_DIRECTORIES(/opt/local/lib)
 ENDIF()
 
-SET(SOURCES avl.c avl-cmp.c blob.c blobmsg.c uloop.c usock.c)
+SET(SOURCES avl.c avl-cmp.c blob.c blobmsg.c uloop.c usock.c vlist.c)
 
 ADD_LIBRARY(ubox SHARED ${SOURCES})
 
diff --git a/vlist.c b/vlist.c
new file mode 100644
index 0000000..b2de7d6
--- /dev/null
+++ b/vlist.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include "vlist.h"
+
+void
+vlist_init(struct vlist_tree *tree, avl_tree_comp cmp, vlist_update_cb update)
+{
+	tree->update = update;
+	tree->version = 1;
+
+	avl_init(&tree->avl, cmp, 0, tree);
+}
+
+void
+vlist_delete(struct vlist_tree *tree, struct vlist_node *node)
+{
+	if (!tree->no_delete)
+		avl_delete(&tree->avl, &node->avl);
+	tree->update(tree, NULL, node);
+}
+
+void
+vlist_add(struct vlist_tree *tree, struct vlist_node *node, void *key)
+{
+	struct vlist_node *old_node = NULL;
+	struct avl_node *anode;
+
+	node->avl.key = key;
+	node->version = tree->version;
+
+	anode = avl_find(&tree->avl, key);
+	if (anode) {
+		old_node = container_of(anode, struct vlist_node, avl);
+		if (tree->keep_old || tree->no_delete) {
+			old_node->version = tree->version;
+			goto update_only;
+		}
+
+		avl_delete(&tree->avl, anode);
+	}
+
+	avl_insert(&tree->avl, &node->avl);
+
+update_only:
+	tree->update(tree, node, old_node);
+}
+
+void
+vlist_flush(struct vlist_tree *tree)
+{
+	struct vlist_node *node, *tmp;
+
+	avl_for_each_element_safe(&tree->avl, node, avl, tmp) {
+		if ((node->version == tree->version || node->version == -1) &&
+		    tree->version != -1)
+			continue;
+
+		vlist_delete(tree, node);
+	}
+}
+
+void
+vlist_flush_all(struct vlist_tree *tree)
+{
+	tree->version = -1;
+	vlist_flush(tree);
+}
+
+
diff --git a/vlist.h b/vlist.h
new file mode 100644
index 0000000..19c1c20
--- /dev/null
+++ b/vlist.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "avl.h"
+
+struct vlist_tree;
+struct vlist_node;
+
+typedef void (*vlist_update_cb)(struct vlist_tree *tree,
+				struct vlist_node *node_new,
+				struct vlist_node *node_old);
+
+struct vlist_tree {
+	struct avl_tree avl;
+
+	vlist_update_cb update;
+	bool keep_old;
+	bool no_delete;
+
+	int version;
+};
+
+struct vlist_node {
+	struct avl_node avl;
+	int version;
+};
+
+void vlist_init(struct vlist_tree *tree, avl_tree_comp cmp, vlist_update_cb update);
+
+#define vlist_find(tree, name, element, node_member) \
+	avl_find_element(&(tree)->avl, name, element, node_member.avl)
+
+static inline void vlist_update(struct vlist_tree *tree)
+{
+	tree->version++;
+}
+
+void vlist_add(struct vlist_tree *tree, struct vlist_node *node, void *key);
+void vlist_delete(struct vlist_tree *tree, struct vlist_node *node);
+void vlist_flush(struct vlist_tree *tree);
+void vlist_flush_all(struct vlist_tree *tree);
+
+#define vlist_for_each_element(tree, element, node_member) \
+	avl_for_each_element(&(tree)->avl, element, node_member.avl)
+