[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, 5 insertions, 6 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 0f5e8387ccb4..93153d105619 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -60,10 +60,10 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 
         skb_push(skb, -skb_network_offset(skb));
         top_iph = ip_hdr(skb);
-        esph = (struct ip_esp_hdr *)(skb_network_header(skb) +
-                                     top_iph->ihl * 4);
+        esph = (struct ip_esp_hdr *)skb_transport_header(skb);
         top_iph->tot_len = htons(skb->len + alen);
-        *(skb_tail_pointer(trailer) - 1) = top_iph->protocol;
+        *(skb_tail_pointer(trailer) - 1) = *skb_mac_header(skb);
+        *skb_mac_header(skb) = IPPROTO_ESP;
 
         spin_lock_bh(&x->lock);
 
@@ -91,9 +91,8 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
                         break;
                 }
 
-                top_iph->protocol = IPPROTO_UDP;
-        } else
-                top_iph->protocol = IPPROTO_ESP;
+                *skb_mac_header(skb) = IPPROTO_UDP;
+        }
 
         esph->spi = x->id.spi;
         esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq);