datapath: Try to avoid custom checksum update function.

[sliver-openvswitch.git] / datapath / checksum.h

diff --git a/datapath/checksum.h b/datapath/checksum.h
index bf93179..7d65396 100644 (file)
--- a/datapath/checksum.h
+++ b/datapath/checksum.h
@@ -12,6 +12,8 @@
 #include <linux/skbuff.h>
 #include <linux/version.h>
 
+#include <net/checksum.h>
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22) || \
        (defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID))
 #define NEED_CSUM_NORMALIZE
@@ -100,4 +102,27 @@ static inline void set_skb_csum_pointers(struct sk_buff *skb, u16 csum_start,
 #endif
 }
 
+#if defined(NEED_CSUM_NORMALIZE) || LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
+/* This is really compatibility code that belongs in the compat directory.
+ * However, it needs access to our normalized checksum values, so put it here.
+ */
+#define inet_proto_csum_replace4 rpl_inet_proto_csum_replace4
+static inline void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
+                                           __be32 from, __be32 to,
+                                           int pseudohdr)
+{
+       __be32 diff[] = { ~from, to };
+
+       if (get_ip_summed(skb) != OVS_CSUM_PARTIAL) {
+               *sum = csum_fold(csum_partial((char *)diff, sizeof(diff),
+                               ~csum_unfold(*sum)));
+               if (get_ip_summed(skb) == OVS_CSUM_COMPLETE && pseudohdr)
+                       skb->csum = ~csum_partial((char *)diff, sizeof(diff),
+                                               ~skb->csum);
+       } else if (pseudohdr)
+               *sum = ~csum_fold(csum_partial((char *)diff, sizeof(diff),
+                               csum_unfold(*sum)));
+}
+#endif
+
 #endif /* checksum.h */