[XFRM]: Add generation count to xfrm_state and xfrm_dst.

Each xfrm_state inserted gets a new generation counter
value.  When a bundle is created, the xfrm_dst objects
get the current generation counter of the xfrm_state
they will attach to at dst->xfrm.

xfrm_bundle_ok() will return false if it sees an
xfrm_dst with a generation count different from the
generation count of the xfrm_state that dst points to.

This provides a facility by which to passively and
cheaply invalidate cached IPSEC routes during SA
database changes.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 3405e5d9d51c..fd4a300b5baf 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -104,6 +104,8 @@ struct xfrm_state
         struct xfrm_id          id;
         struct xfrm_selector    sel;
 
+        u32                     genid;
+
         /* Key manger bits */
         struct {
                 u8              state;
@@ -590,6 +592,7 @@ struct xfrm_dst
                 struct rt6_info         rt6;
         } u;
         struct dst_entry *route;
+        u32 genid;
         u32 route_mtu_cached;
         u32 child_mtu_cached;
         u32 route_cookie;