-void nf_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
- __be32 from, __be32 to, int pseudohdr)
-{
- __be32 diff[] = { ~from, to };
- if (skb->ip_summed != CHECKSUM_PARTIAL) {
- *sum = csum_fold(csum_partial((char *)diff, sizeof(diff),
- ~csum_unfold(*sum)));
- if (skb->ip_summed == CHECKSUM_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)));
-}
-EXPORT_SYMBOL(nf_proto_csum_replace4);
-