net: Add skb_gro_receive

[linux-2.6-omap-h63xx.git] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 18e224af05a632a213fdd19634dc290f01491646..b8d0abb264334d6d5589d107c8cf4007e393ffd4 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2582,6 +2582,65 @@ err:
 
 EXPORT_SYMBOL_GPL(skb_segment);
 
+int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+{
+       struct sk_buff *p = *head;
+       struct sk_buff *nskb;
+       unsigned int headroom;
+       unsigned int hlen = p->data - skb_mac_header(p);
+
+       if (hlen + p->len + skb->len >= 65536)
+               return -E2BIG;
+
+       if (skb_shinfo(p)->frag_list)
+               goto merge;
+
+       headroom = skb_headroom(p);
+       nskb = netdev_alloc_skb(p->dev, headroom);
+       if (unlikely(!nskb))
+               return -ENOMEM;
+
+       __copy_skb_header(nskb, p);
+       nskb->mac_len = p->mac_len;
+
+       skb_reserve(nskb, headroom);
+
+       skb_set_mac_header(nskb, -hlen);
+       skb_set_network_header(nskb, skb_network_offset(p));
+       skb_set_transport_header(nskb, skb_transport_offset(p));
+
+       memcpy(skb_mac_header(nskb), skb_mac_header(p), hlen);
+
+       *NAPI_GRO_CB(nskb) = *NAPI_GRO_CB(p);
+       skb_shinfo(nskb)->frag_list = p;
+       skb_header_release(p);
+       nskb->prev = p;
+
+       nskb->data_len += p->len;
+       nskb->truesize += p->len;
+       nskb->len += p->len;
+
+       *head = nskb;
+       nskb->next = p->next;
+       p->next = NULL;
+
+       p = nskb;
+
+merge:
+       NAPI_GRO_CB(p)->count++;
+       p->prev->next = skb;
+       p->prev = skb;
+       skb_header_release(skb);
+
+       p->data_len += skb->len;
+       p->truesize += skb->len;
+       p->len += skb->len;
+
+       NAPI_GRO_CB(skb)->same_flow = 1;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(skb_gro_receive);
+
 void __init skb_init(void)
 {
        skbuff_head_cache = kmem_cache_create("skbuff_head_cache",