diff --git a/checksum.h b/checksum.h
new file mode 100644
index 0000000..c8346a0
--- /dev/null
+++ b/checksum.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2011 Daniel Drown
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * checksum.h - checksum functions
+ */
+#ifndef __CHECKSUM_H__
+#define __CHECKSUM_H__
+
+uint32_t ip_checksum_add(uint32_t current_sum, const void *data, int len);
+uint16_t ip_checksum_finish(uint32_t temp_sum);
+uint16_t ip_checksum(const void *data, int len);
+
+uint32_t ipv6_pseudo_header_checksum(uint32_t current_sum, const struct ip6_hdr *ip6);
+uint32_t ipv4_pseudo_header_checksum(uint32_t current_sum, const struct iphdr *ip);
+
+#endif /* __CHECKSUM_H__ */