[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/net/ipv4/udp.c b/net/ipv4/udp.c
index 1bbf551..b4cad50 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -867,7 +867,7 @@
 	{
 		sin->sin_family = AF_INET;
 		sin->sin_port = skb->h.uh->source;
-		sin->sin_addr.s_addr = skb->nh.iph->saddr;
+		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 		memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 	}
 	if (inet->cmsg_flags)
@@ -990,7 +990,7 @@
 		return 0;
 
 	/* Now we can update and verify the packet length... */
-	iph = skb->nh.iph;
+	iph = ip_hdr(skb);
 	iphlen = iph->ihl << 2;
 	iph->tot_len = htons(ntohs(iph->tot_len) - len);
 	if (skb->len < iphlen + len) {
@@ -1168,6 +1168,7 @@
 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
 				 int proto)
 {
+	const struct iphdr *iph;
 	int err;
 
 	UDP_SKB_CB(skb)->partial_cov = 0;
@@ -1179,16 +1180,16 @@
 			return err;
 	}
 
+	iph = ip_hdr(skb);
 	if (uh->check == 0) {
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 	} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
-	       if (!csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr,
-				      skb->len, proto, skb->csum))
+	       if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
+				      proto, skb->csum))
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
 	if (skb->ip_summed != CHECKSUM_UNNECESSARY)
-		skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
-					       skb->nh.iph->daddr,
+		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
 					       skb->len, proto, 0);
 	/* Probably, we should checksum udp header (it should be in cache
 	 * in any case) and data in tiny packets (< rx copybreak).
@@ -1208,8 +1209,8 @@
 	struct udphdr *uh = skb->h.uh;
 	unsigned short ulen;
 	struct rtable *rt = (struct rtable*)skb->dst;
-	__be32 saddr = skb->nh.iph->saddr;
-	__be32 daddr = skb->nh.iph->daddr;
+	__be32 saddr = ip_hdr(skb)->saddr;
+	__be32 daddr = ip_hdr(skb)->daddr;
 
 	/*
 	 *  Validate the packet.