[NETFILTER]: Add address family specific checksum helpers
Add checksum operation which takes care of verifying the checksum and
dealing with HW checksum errors and avoids multiple checksum
operations by setting ip_summed to CHECKSUM_UNNECESSARY after
successful verification.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index f514a01..3e9ecfa 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -79,8 +79,42 @@
return 0;
}
+unsigned int nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol)
+{
+ 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;
+}
+
+EXPORT_SYMBOL(nf_ip6_checksum);
+
static struct nf_afinfo nf_ip6_afinfo = {
.family = AF_INET6,
+ .checksum = nf_ip6_checksum,
.saveroute = nf_ip6_saveroute,
.reroute = nf_ip6_reroute,
.route_key_size = sizeof(struct ip6_rt_info),