[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>

1 files changed, 5 insertions, 0 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 */