ip_tunnel: push generic protocol handling to ip_tunnel module.

Process skb tunnel header before sending packet to protocol handler.
this allows code sharing between gre and ovs gre modules.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 34 insertions, 0 deletions

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 927687e83f18..7167b08977df 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -86,3 +86,37 @@ int iptunnel_xmit(struct net *net, struct rtable *rt,
 	return pkt_len;
 }
 EXPORT_SYMBOL_GPL(iptunnel_xmit);
+
+int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
+{
+	if (unlikely(!pskb_may_pull(skb, hdr_len)))
+		return -ENOMEM;
+
+	skb_pull_rcsum(skb, hdr_len);
+
+	if (inner_proto == htons(ETH_P_TEB)) {
+		struct ethhdr *eh = (struct ethhdr *)skb->data;
+
+		if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
+			return -ENOMEM;
+
+		if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
+			skb->protocol = eh->h_proto;
+		else
+			skb->protocol = htons(ETH_P_802_2);
+
+	} else {
+		skb->protocol = inner_proto;
+	}
+
+	nf_reset(skb);
+	secpath_reset(skb);
+	if (!skb->l4_rxhash)
+		skb->rxhash = 0;
+	skb_dst_drop(skb);
+	skb->vlan_tci = 0;
+	skb_set_queue_mapping(skb, 0);
+	skb->pkt_type = PACKET_HOST;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iptunnel_pull_header);