xfrm: Clone states properly on migration

We loose a lot of information of the original state if we
clone it with xfrm_state_clone(). In particular, there is
no crypto algorithm attached if the original state uses
an aead algorithm. This patch add the missing information
to the clone state.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index afa5730..fb5654a 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1648,6 +1648,11 @@
 }
 #endif
 
+static inline int aead_len(struct xfrm_algo_aead *alg)
+{
+	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
+}
+
 static inline int xfrm_alg_len(const struct xfrm_algo *alg)
 {
 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
@@ -1686,6 +1691,12 @@
 	return 0;
 }
 
+static inline struct xfrm_algo_aead *xfrm_algo_aead_clone(struct xfrm_algo_aead *orig)
+{
+	return kmemdup(orig, aead_len(orig), GFP_KERNEL);
+}
+
+
 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
 {
 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);