+ struct ipv6hdr *ip6h = skb->nh.ipv6h;
+ unsigned int csum = 0;
+
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (hook != NF_IP6_PRE_ROUTING && hook != NF_IP6_LOCAL_IN)
+ break;
+ if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ skb->len - dataoff, protocol,
+ csum_sub(skb->csum,
+ skb_checksum(skb, 0,
+ dataoff, 0)))) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ break;
+ }
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ skb->len - dataoff,
+ protocol,
+ csum_sub(0,
+ skb_checksum(skb, 0,
+ dataoff, 0)));
+ csum = __skb_checksum_complete(skb);
+ }
+ return csum;