X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fcsum.c;h=fb32a530dfce8d9935b78cb24906dfc7df2ce2c8;hb=f40869bdf6feca4d3ff7c59a1fb1f7ac101bc967;hp=668d7108e86d7e47865f6ee3f56a02d0db774c1b;hpb=6879df6b58388ef7dbd8f27c9c152a2df902773d;p=sliver-openvswitch.git

diff --git a/lib/csum.c b/lib/csum.c
index 668d7108e..fb32a530d 100644
--- a/lib/csum.c
+++ b/lib/csum.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,8 @@
 #include "csum.h"
 #include "unaligned.h"
 
+#ifndef __CHECKER__
+
 /* Returns the IP checksum of the 'n' bytes in 'data'.
  *
  * The return value has the same endianness as the data.  That is, if 'data'
@@ -109,3 +111,23 @@ recalc_csum32(ovs_be16 old_csum, ovs_be32 old_u32, ovs_be32 new_u32)
     return recalc_csum16(recalc_csum16(old_csum, old_u32, new_u32),
                          old_u32 >> 16, new_u32 >> 16);
 }
+
+/* Returns the new checksum for a packet in which the checksum field previously
+ * contained 'old_csum' and in which a field that contained 'old_u32[4]' was
+ * changed to contain 'new_u32[4]'. */
+ovs_be16
+recalc_csum128(ovs_be16 old_csum, ovs_be32 old_u32[4],
+               const ovs_be32 new_u32[4])
+{
+    ovs_be16 new_csum = old_csum;
+    int i;
+
+    for (i = 0; i < 4; ++i) {
+        new_csum = recalc_csum32(new_csum, old_u32[i], new_u32[i]);
+    }
+    return new_csum;
+}
+#else  /* __CHECKER__ */
+/* Making sparse happy with these functions also makes them unreadable, so
+ * don't bother to show it their implementations. */
+#endif