+static struct sk_buff **inet_gro_receive(struct sk_buff **head,
+ struct sk_buff *skb)
+{
+ const struct net_protocol *ops;
+ struct sk_buff **pp = NULL;
+ struct sk_buff *p;
+ struct iphdr *iph;
+ unsigned int hlen;
+ unsigned int off;
+ unsigned int id;
+ int flush = 1;
+ int proto;
+
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*iph);
+ iph = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ iph = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!iph))
+ goto out;
+ }
+
+ proto = iph->protocol & (MAX_INET_PROTOS - 1);
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet_protos[proto]);
+ if (!ops || !ops->gro_receive)
+ goto out_unlock;
+
+ if (*(u8 *)iph != 0x45)
+ goto out_unlock;
+
+ if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
+ goto out_unlock;
+
+ id = ntohl(*(u32 *)&iph->id);
+ flush = (u16)((ntohl(*(u32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
+ id >>= 16;
+
+ for (p = *head; p; p = p->next) {
+ struct iphdr *iph2;
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ iph2 = ip_hdr(p);
+
+ if ((iph->protocol ^ iph2->protocol) |
+ (iph->tos ^ iph2->tos) |
+ (iph->saddr ^ iph2->saddr) |
+ (iph->daddr ^ iph2->daddr)) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+
+ /* All fields must match except length and checksum. */
+ NAPI_GRO_CB(p)->flush |=
+ (iph->ttl ^ iph2->ttl) |
+ ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
+
+ NAPI_GRO_CB(p)->flush |= flush;
+ }
+
+ NAPI_GRO_CB(skb)->flush |= flush;
+ skb_gro_pull(skb, sizeof(*iph));
+ skb_set_transport_header(skb, skb_gro_offset(skb));
+
+ pp = ops->gro_receive(head, skb);
+
+out_unlock:
+ rcu_read_unlock();
+
+out:
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ return pp;
+}
+
+static int inet_gro_complete(struct sk_buff *skb)
+{
+ const struct net_protocol *ops;
+ struct iphdr *iph = ip_hdr(skb);
+ int proto = iph->protocol & (MAX_INET_PROTOS - 1);
+ int err = -ENOSYS;
+ __be16 newlen = htons(skb->len - skb_network_offset(skb));
+
+ csum_replace2(&iph->check, iph->tot_len, newlen);
+ iph->tot_len = newlen;
+
+ rcu_read_lock();
+ ops = rcu_dereference(inet_protos[proto]);
+ if (WARN_ON(!ops || !ops->gro_complete))
+ goto out_unlock;
+
+ err = ops->gro_complete(skb);
+
+out_unlock:
+ rcu_read_unlock();
+
+ return err;
+}
+