1 files changed, 12 insertions, 1 deletions
diff --git a/lib/hash.h b/lib/hash.h
index fc5fea14..4239b1d8 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -1,4 +1,14 @@
-
+/*
+ *	BIRD Library -- Generic Hash Table
+ *
+ *	(c) 2013 Ondrej Zajicek <santiago@crfreenet.org>
+ *	(c) 2013 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_HASH_H_
+#define _BIRD_HASH_H_
 
 #define HASH(type)		struct { type **data; uint count, order; }
 #define HASH_TYPE(v)		typeof(** (v).data)
@@ -178,3 +188,4 @@
 
 #define HASH_WALK_FILTER_END } while (0)
 
+#endif