[SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iph

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ip.h b/include/linux/ip.h
index 1d36b97..f2f26db 100644
--- a/include/linux/ip.h
+++ b/include/linux/ip.h
@@ -104,6 +104,15 @@
 	/*The options start here. */
 };
 
+#ifdef __KERNEL__
+#include <linux/skbuff.h>
+
+static inline struct iphdr *ip_hdr(const struct sk_buff *skb)
+{
+	return (struct iphdr *)skb_network_header(skb);
+}
+#endif
+
 struct ip_auth_hdr {
 	__u8  nexthdr;
 	__u8  hdrlen;		/* This one is measured in 32 bit units! */