xfrm: Add support for IPsec extended sequence numbers

This patch adds support for IPsec extended sequence numbers (esn)
as defined in RFC 4303. The bits to manage the anti-replay window
are based on a patch from Alex Badea.

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, 4 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 55d5f5c3d119..872065ca7f8c 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -107,6 +107,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
         struct net *net = dev_net(skb->dev);
         int err;
         __be32 seq;
+        __be32 seq_hi;
         struct xfrm_state *x;
         xfrm_address_t *daddr;
         struct xfrm_mode *inner_mode;
@@ -184,7 +185,10 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
                 spin_unlock(&x->lock);
 
+                seq_hi = htonl(xfrm_replay_seqhi(x, seq));
+
                 XFRM_SKB_CB(skb)->seq.input.low = seq;
+                XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
 
                 nexthdr = x->type->input(x, skb);