datapath: Properly calculate checksum when updating TOS field.

[sliver-openvswitch.git] / datapath / linux / compat / include / net / checksum.h

diff --git a/datapath/linux/compat/include/net/checksum.h b/datapath/linux/compat/include/net/checksum.h
index 73f2f59..ee64f24 100644 (file)
--- a/datapath/linux/compat/include/net/checksum.h
+++ b/datapath/linux/compat/include/net/checksum.h
@@ -25,6 +25,11 @@ static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to)
 
        *sum = csum_fold(csum_partial((char *)diff, sizeof(diff), ~csum_unfold(*sum)));
 }
+
+static inline void csum_replace2(__sum16 *sum, __be16 from, __be16 to)
+{
+       csum_replace4(sum, (__force __be32)from, (__force __be32)to);
+}
 #endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)