[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, 7 insertions, 5 deletions

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index dc68b7269c3c..1c914386982f 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -238,8 +238,8 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
         top_iph = (struct ipv6hdr *)skb->data;
         top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
 
-        nexthdr = *skb->nh.raw;
-        *skb->nh.raw = IPPROTO_AH;
+        nexthdr = *skb_network_header(skb);
+        *skb_network_header(skb) = IPPROTO_AH;
 
         /* When there are no extension headers, we only need to save the first
          * 8 bytes of the base IP header.
@@ -341,7 +341,7 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
             pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
                 goto out;
 
-        hdr_len = skb->data - skb->nh.raw;
+        hdr_len = skb->data - skb_network_header(skb);
         ah = (struct ipv6_auth_hdr*)skb->data;
         ahp = x->data;
         nexthdr = ah->nexthdr;
@@ -354,7 +354,7 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
         if (!pskb_may_pull(skb, ah_hlen))
                 goto out;
 
-        tmp_hdr = kmemdup(skb->nh.raw, hdr_len, GFP_ATOMIC);
+        tmp_hdr = kmemdup(skb_network_header(skb), hdr_len, GFP_ATOMIC);
         if (!tmp_hdr)
                 goto out;
         if (ipv6_clear_mutable_options(skb->nh.ipv6h, hdr_len, XFRM_POLICY_IN))
@@ -382,7 +382,9 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
                 }
         }
 
-        skb->h.raw = memcpy(skb->nh.raw += ah_hlen, tmp_hdr, hdr_len);
+        skb->nh.raw += ah_hlen;
+        memcpy(skb_network_header(skb), tmp_hdr, hdr_len);
+        skb->h.raw = skb->nh.raw;
         __skb_pull(skb, ah_hlen + hdr_len);
 
         kfree(tmp_hdr);