[IPSEC]: Use IPv6 calling convention as the convention for x->mode->output

The IPv6 calling convention for x->mode->output is more general and could
help an eventual protocol-generic x->type->output implementation.  This
patch adopts it for IPv4 as well and modifies the IPv4 type output functions
accordingly.

It also rewrites the IPv6 mac/transport header calculation to be based off
the network header where practical.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index dbb1f11721e4..e4f7aa39978d 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -82,14 +82,14 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
                         goto error;
         }
 
-        ah = (struct ip_auth_hdr *)((char *)top_iph+top_iph->ihl*4);
-        ah->nexthdr = top_iph->protocol;
+        ah = (struct ip_auth_hdr *)skb_transport_header(skb);
+        ah->nexthdr = *skb_mac_header(skb);
+        *skb_mac_header(skb) = IPPROTO_AH;
 
         top_iph->tos = 0;
         top_iph->tot_len = htons(skb->len);
         top_iph->frag_off = 0;
         top_iph->ttl = 0;
-        top_iph->protocol = IPPROTO_AH;
         top_iph->check = 0;
 
         ahp = x->data;