[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, 5 deletions

diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index 1929d451dab5..bf74f64fe5fb 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -98,10 +98,10 @@ out:
 static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
 {
         struct ipcomp_data *ipcd = x->data;
-        const int ihlen = ip_hdrlen(skb);
+        const int ihlen = skb_transport_offset(skb);
         const int plen = skb->len - ihlen;
         int dlen = IPCOMP_SCRATCH_SIZE;
-        u8 *start = skb->data + ihlen;
+        u8 *start = skb_transport_header(skb);
         const int cpu = get_cpu();
         u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
         struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
@@ -154,11 +154,11 @@ static int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
 
         /* Install ipcomp header, convert into ipcomp datagram. */
         iph->tot_len = htons(skb->len);
-        ipch = (struct ip_comp_hdr *)((char *)iph + iph->ihl * 4);
-        ipch->nexthdr = iph->protocol;
+        ipch = (struct ip_comp_hdr *)skb_transport_header(skb);
+        ipch->nexthdr = *skb_mac_header(skb);
         ipch->flags = 0;
         ipch->cpi = htons((u16 )ntohl(x->id.spi));
-        iph->protocol = IPPROTO_COMP;
+        *skb_mac_header(skb) = IPPROTO_COMP;
         ip_send_check(iph);
         return 0;