[IPSEC]: Remove nhoff from xfrm_input

The nhoff field isn't actually necessary in xfrm_input.  For tunnel
mode transforms we now throw away the output IP header so it makes no
sense to fill in the nexthdr field.  For transport mode we can now let
the function transport_finish do the setting and it knows where the
nexthdr field is.

The only other thing that needs the nexthdr field to be set is the
header extraction code.  However, we can simply move the protocol
extraction out of the generic header extraction.

We want to minimise the amount of info we have to carry around between
transforms as this simplifies the resumption process for async crypto.

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

1 files changed, 2 insertions, 3 deletions

diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 5cad522e8ef6..cce9d4586045 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -102,7 +102,6 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
         __be32 seq;
         struct xfrm_state *x;
         int decaps = 0;
-        unsigned int nhoff = XFRM_SPI_SKB_CB(skb)->nhoff;
         unsigned int daddroff = XFRM_SPI_SKB_CB(skb)->daddroff;
 
         /* Allocate new secpath or COW existing one. */
@@ -157,8 +156,6 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
                         goto drop_unlock;
                 }
 
-                skb_network_header(skb)[nhoff] = nexthdr;
-
                 /* only the first xfrm gets the encap type */
                 encap_type = 0;
 
@@ -170,6 +167,8 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
                 spin_unlock(&x->lock);
 
+                XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
+
                 if (x->inner_mode->input(x, skb))
                         goto drop;