xfrm: Add basic infrastructure to support IPsec extended sequence numbers

This patch adds the struct xfrm_replay_state_esn which will be
used to support IPsec extended sequence numbers and anti replay windows
bigger than 32 packets. Also we add a function that returns the actual
size of the xfrm_replay_state_esn, a xfrm netlink atribute and a xfrm state
flag for the use of extended sequence numbers.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 8f8bd82606bf..7640822bc515 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -186,9 +186,11 @@ struct xfrm_state {
 
         /* State for replay detection */
         struct xfrm_replay_state replay;
+        struct xfrm_replay_state_esn *replay_esn;
 
         /* Replay detection state at the time we sent the last notification */
         struct xfrm_replay_state preplay;
+        struct xfrm_replay_state_esn *preplay_esn;
 
         /* internal flag that only holds state for delayed aevent at the
          * moment
@@ -1569,6 +1571,11 @@ static inline int xfrm_alg_auth_len(const struct xfrm_algo_auth *alg)
         return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
 }
 
+static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay_esn)
+{
+        return sizeof(*replay_esn) + replay_esn->bmp_len * sizeof(__u32);
+}
+
 #ifdef CONFIG_XFRM_MIGRATE
 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
 {