- if (skb->proto_csum_blank) {
- if (skb->protocol != htons(ETH_P_IP))
- goto out;
- if (!skb_pull_up_to(skb, skb->nh.iph + 1))
- goto out;
- skb->h.raw = (unsigned char *)skb->nh.iph + 4*skb->nh.iph->ihl;
- switch (skb->nh.iph->protocol) {
- case IPPROTO_TCP:
- skb->csum = offsetof(struct tcphdr, check);
- break;
- case IPPROTO_UDP:
- skb->csum = offsetof(struct udphdr, check);
- break;
- default:
- if (net_ratelimit())
- printk(KERN_ERR "Attempting to checksum a non-"
- "TCP/UDP packet, dropping a protocol"
- " %d packet", skb->nh.iph->protocol);
- goto out;
- }
- if (!skb_pull_up_to(skb, skb->h.raw + skb->csum + 2))
- goto out;
- skb->ip_summed = CHECKSUM_HW;
- skb->proto_csum_blank = 0;
+ struct iphdr *iph;
+ unsigned char *th;
+ int err = -EPROTO;
+ __u16 csum_start, csum_offset;
+
+ if (!skb->proto_csum_blank)
+ return 0;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ goto out;
+
+ if (!skb_pull_up_to(skb, skb_network_header(skb) + 1))
+ goto out;
+
+ iph = ip_hdr(skb);
+ th = skb_network_header(skb) + 4 * iph->ihl;
+
+ csum_start = th - skb->head;
+ switch (iph->protocol) {
+ case IPPROTO_TCP:
+ csum_offset = offsetof(struct tcphdr, check);
+ break;
+ case IPPROTO_UDP:
+ csum_offset = offsetof(struct udphdr, check);
+ break;
+ default:
+ if (net_ratelimit())
+ printk(KERN_ERR "Attempting to checksum a non-"
+ "TCP/UDP packet, dropping a protocol"
+ " %d packet", iph->protocol);
+ goto out;