[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, 5 insertions, 3 deletions

diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 8ce5ef2d0b1c..498f17b5c42f 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -87,9 +87,10 @@ static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 {
         int err = -EINVAL;
         const unsigned char *old_mac;
+        const unsigned char *nh = skb_network_header(skb);
 
-        if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6
-            && skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
+        if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 &&
+            nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
                 goto out;
         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
                 goto out;
@@ -98,7 +99,8 @@ static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
             (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
                 goto out;
 
-        if (skb->nh.raw[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
+        nh = skb_network_header(skb);
+        if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
                 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
                         ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
                 if (!(x->props.flags & XFRM_STATE_NOECN))