[IPSEC]: Add xfrm_input_state helper

This patch adds the xfrm_input_state helper function which returns the
current xfrm state being processed on the input path given an sk_buff.
This is currently only used by xfrm_input but will be used by ESP upon
asynchronous resumption.

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

2 files changed, 6 insertions, 1 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 503d0d294a4c..fe881b6e2bd0 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1317,4 +1317,9 @@ static inline void xfrm_states_delete(struct xfrm_state **states, int n)
 }
 #endif
 
+static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
+{
+        return skb->sp->xvec[skb->sp->len - 1];
+}
+
 #endif  /* _NET_XFRM_H */
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 8b2b1b59133e..8624cbdb2a1e 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -109,7 +109,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
         /* A negative encap_type indicates async resumption. */
         if (encap_type < 0) {
                 async = 1;
-                x = skb->sp->xvec[skb->sp->len - 1];
+                x = xfrm_input_state(skb);
                 seq = XFRM_SKB_CB(skb)->seq;
                 goto resume;
         }