-static DEFINE_PER_CPU(struct net_device_stats, loopback_stats);
-
-#define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16)
-
-/* KISS: just allocate small chunks and copy bits.
- *
- * So, in fact, this is documentation, explaining what we expect
- * of largesending device modulo TCP checksum, which is ignored for loopback.
- */
-
-static void emulate_large_send_offload(struct sk_buff *skb)
-{
- struct iphdr *iph = skb->nh.iph;
- struct tcphdr *th = (struct tcphdr*)(skb->nh.raw + (iph->ihl * 4));
- unsigned int doffset = (iph->ihl + th->doff) * 4;
- unsigned int mtu = skb_shinfo(skb)->tso_size + doffset;
- unsigned int offset = 0;
- u32 seq = ntohl(th->seq);
- u16 id = ntohs(iph->id);
-
- while (offset + doffset < skb->len) {
- unsigned int frag_size = min(mtu, skb->len - offset) - doffset;
- struct sk_buff *nskb = alloc_skb(mtu + 32, GFP_ATOMIC);
-
- if (!nskb)
- break;
- skb_reserve(nskb, 32);
- nskb->mac.raw = nskb->data - 14;
- nskb->nh.raw = nskb->data;
- iph = nskb->nh.iph;
- memcpy(nskb->data, skb->nh.raw, doffset);
- if (skb_copy_bits(skb,
- doffset + offset,
- nskb->data + doffset,
- frag_size))
- BUG();
- skb_put(nskb, doffset + frag_size);
- nskb->ip_summed = CHECKSUM_UNNECESSARY;
- nskb->dev = skb->dev;
- nskb->priority = skb->priority;
- nskb->protocol = skb->protocol;
- nskb->dst = dst_clone(skb->dst);
- memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
- nskb->pkt_type = skb->pkt_type;
-
- th = (struct tcphdr*)(nskb->nh.raw + iph->ihl*4);
- iph->tot_len = htons(frag_size + doffset);
- iph->id = htons(id);
- iph->check = 0;
- iph->check = ip_fast_csum((unsigned char *) iph, iph->ihl);
- th->seq = htonl(seq);
- if (offset + doffset + frag_size < skb->len)
- th->fin = th->psh = 0;
- netif_rx(nskb);
- offset += frag_size;
- seq += frag_size;
- id++;
- }
-
- dev_kfree_skb(skb);
-}