[NETFILTER] bridge: code rearrangement for clarity

[net-next-2.6.git] / net / bridge / br_netfilter.c

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 05b3de88824362fd797c1fe3309567520cc163df..b498efcfe451b0e74c38e94626777292c23688bc 100644 (file)
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -127,14 +127,37 @@ static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
 
 static inline void nf_bridge_save_header(struct sk_buff *skb)
 {
-        int header_size = 16;
+        int header_size = ETH_HLEN;
 
        if (skb->protocol == htons(ETH_P_8021Q))
-               header_size = 18;
+               header_size += VLAN_HLEN;
 
        memcpy(skb->nf_bridge->data, skb->data - header_size, header_size);
 }
 
+/*
+ * When forwarding bridge frames, we save a copy of the original
+ * header before processing.
+ */
+int nf_bridge_copy_header(struct sk_buff *skb)
+{
+       int err;
+        int header_size = ETH_HLEN;
+
+       if (skb->protocol == htons(ETH_P_8021Q))
+               header_size += VLAN_HLEN;
+
+       err = skb_cow(skb, header_size);
+       if (err)
+               return err;
+
+       memcpy(skb->data - header_size, skb->nf_bridge->data, header_size);
+
+       if (skb->protocol == htons(ETH_P_8021Q))
+               __skb_push(skb, VLAN_HLEN);
+       return 0;
+}
+
 /* PF_BRIDGE/PRE_ROUTING *********************************************/
 /* Undo the changes made for ip6tables PREROUTING and continue the
  * bridge PRE_ROUTING hook. */