xfrm: Store aalg in xfrm_state with a user specified truncation length

Adding a xfrm_state requires an authentication algorithm specified
either as xfrm_algo or as xfrm_algo_auth with a specific truncation
length. For compatibility, both attributes are dumped to userspace,
and we also accept both attributes, but prefer the new syntax.

If no truncation length is specified, or the authentication algorithm
is specified using xfrm_algo, the truncation length from the algorithm
description in the kernel is used.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 1 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 93d184b91a8c..6d85861ab990 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -162,7 +162,7 @@ struct xfrm_state {
         struct xfrm_lifetime_cfg lft;
 
         /* Data for transformer */
-        struct xfrm_algo        *aalg;
+        struct xfrm_algo_auth   *aalg;
         struct xfrm_algo        *ealg;
         struct xfrm_algo        *calg;
         struct xfrm_algo_aead   *aead;
@@ -1532,12 +1532,22 @@ static inline int xfrm_alg_len(struct xfrm_algo *alg)
         return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
 }
 
+static inline int xfrm_alg_auth_len(struct xfrm_algo_auth *alg)
+{
+        return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
+}
+
 #ifdef CONFIG_XFRM_MIGRATE
 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
 {
         return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
 }
 
+static inline struct xfrm_algo_auth *xfrm_algo_auth_clone(struct xfrm_algo_auth *orig)
+{
+        return kmemdup(orig, xfrm_alg_auth_len(orig), GFP_KERNEL);
+}
+
 static inline void xfrm_states_put(struct xfrm_state **states, int n)
 {
         int i;