2 files changed, 47 insertions, 1 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 59c5d18cc385..ff4da42fcfc6 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -36,7 +36,11 @@ struct dst_entry {
         struct net_device       *dev;
         struct  dst_ops         *ops;
         unsigned long           _metrics;
-        unsigned long           expires;
+        union {
+                unsigned long           expires;
+                /* point to where the dst_entry copied from */
+                struct dst_entry        *from;
+        };
         struct dst_entry        *path;
         struct neighbour __rcu  *_neighbour;
 #ifdef CONFIG_XFRM
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index b26bb8101981..c64778fd5e13 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -123,6 +123,48 @@ static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
         return ((struct rt6_info *)dst)->rt6i_idev;
 }
 
+static inline void rt6_clean_expires(struct rt6_info *rt)
+{
+        if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
+                dst_release(rt->dst.from);
+
+        rt->rt6i_flags &= ~RTF_EXPIRES;
+        rt->dst.expires = 0;
+}
+
+static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
+{
+        if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
+                dst_release(rt->dst.from);
+
+        rt->rt6i_flags |= RTF_EXPIRES;
+        rt->dst.expires = expires;
+}
+
+static inline void rt6_update_expires(struct rt6_info *rt, int timeout)
+{
+        if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
+                dst_release(rt->dst.from);
+
+        dst_set_expires(&rt->dst, timeout);
+        rt->rt6i_flags |= RTF_EXPIRES;
+}
+
+static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
+{
+        struct dst_entry *new = (struct dst_entry *) from;
+
+        if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) {
+                if (new == rt->dst.from)
+                        return;
+                dst_release(rt->dst.from);
+        }
+
+        rt->rt6i_flags &= ~RTF_EXPIRES;
+        rt->dst.from = new;
+        dst_hold(new);
+}
+
 struct fib6_walker_t {
         struct list_head lh;
         struct fib6_node *root, *node;