[SK_BUFF]: Introduce skb_network_header()

For the places where we need a pointer to the network header, it is still legal
to touch skb->nh.raw directly if just adding to, subtracting from or setting it
to another layer header.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 7194eb40b6d0..95ddbbd1552a 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -154,7 +154,7 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
         ah = (struct ip_auth_hdr*)skb->data;
         iph = skb->nh.iph;
 
-        ihl = skb->data - skb->nh.raw;
+        ihl = skb->data - skb_network_header(skb);
         memcpy(work_buf, iph, ihl);
 
         iph->ttl = 0;
@@ -181,7 +181,8 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
                 }
         }
         ((struct iphdr*)work_buf)->protocol = ah->nexthdr;
-        skb->h.raw = memcpy(skb->nh.raw += ah_hlen, work_buf, ihl);
+        skb->nh.raw += ah_hlen;
+        skb->h.raw = memcpy(skb_network_header(skb), work_buf, ihl);
         __skb_pull(skb, ah_hlen + ihl);
 
         return 0;