net: check for refcount if pop a stacked dst_entry

[net-next-2.6.git] / include / net / dst.h

diff --git a/include/net/dst.h b/include/net/dst.h
index ce078cda6b748a61eadfcf16315b84e8893aeded..81d1413a87010967684febe7344169baa7d828ef 100644 (file)
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -168,6 +168,12 @@ static inline void dst_use(struct dst_entry *dst, unsigned long time)
        dst->lastuse = time;
 }
 
+static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
+{
+       dst->__use++;
+       dst->lastuse = time;
+}
+
 static inline
 struct dst_entry * dst_clone(struct dst_entry * dst)
 {
@@ -177,22 +183,78 @@ struct dst_entry * dst_clone(struct dst_entry * dst)
 }
 
 extern void dst_release(struct dst_entry *dst);
+
+static inline void refdst_drop(unsigned long refdst)
+{
+       if (!(refdst & SKB_DST_NOREF))
+               dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
+}
+
+/**
+ * skb_dst_drop - drops skb dst
+ * @skb: buffer
+ *
+ * Drops dst reference count if a reference was taken.
+ */
 static inline void skb_dst_drop(struct sk_buff *skb)
 {
-       if (skb->_skb_dst)
-               dst_release(skb_dst(skb));
-       skb->_skb_dst = 0UL;
+       if (skb->_skb_refdst) {
+               refdst_drop(skb->_skb_refdst);
+               skb->_skb_refdst = 0UL;
+       }
+}
+
+static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
+{
+       nskb->_skb_refdst = oskb->_skb_refdst;
+       if (!(nskb->_skb_refdst & SKB_DST_NOREF))
+               dst_clone(skb_dst(nskb));
+}
+
+/**
+ * skb_dst_force - makes sure skb dst is refcounted
+ * @skb: buffer
+ *
+ * If dst is not yet refcounted, let's do it
+ */
+static inline void skb_dst_force(struct sk_buff *skb)
+{
+       if (skb_dst_is_noref(skb)) {
+               WARN_ON(!rcu_read_lock_held());
+               skb->_skb_refdst &= ~SKB_DST_NOREF;
+               dst_clone(skb_dst(skb));
+       }
+}
+
+
+/**
+ *     skb_tunnel_rx - prepare skb for rx reinsert
+ *     @skb: buffer
+ *     @dev: tunnel device
+ *
+ *     After decapsulation, packet is going to re-enter (netif_rx()) our stack,
+ *     so make some cleanups, and perform accounting.
+ */
+static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
+{
+       skb->dev = dev;
+       /* TODO : stats should be SMP safe */
+       dev->stats.rx_packets++;
+       dev->stats.rx_bytes += skb->len;
+       skb->rxhash = 0;
+       skb_dst_drop(skb);
+       nf_reset(skb);
 }
 
 /* Children define the path of the packet through the
  * Linux networking.  Thus, destinations are stackable.
  */
 
-static inline struct dst_entry *dst_pop(struct dst_entry *dst)
+static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
 {
-       struct dst_entry *child = dst_clone(dst->child);
+       struct dst_entry *child = skb_dst(skb)->child;
 
-       dst_release(dst);
+       skb_dst_drop(skb);
        return child;
 }
 
@@ -225,21 +287,6 @@ static inline void dst_confirm(struct dst_entry *dst)
                neigh_confirm(dst->neighbour);
 }
 
-static inline void dst_negative_advice(struct dst_entry **dst_p,
-                                      struct sock *sk)
-{
-       struct dst_entry * dst = *dst_p;
-       if (dst && dst->ops->negative_advice) {
-               *dst_p = dst->ops->negative_advice(dst);
-
-               if (dst != *dst_p) {
-                       extern void sk_reset_txq(struct sock *sk);
-
-                       sk_reset_txq(sk);
-               }
-       }
-}
-
 static inline void dst_link_failure(struct sk_buff *skb)
 {
        struct dst_entry *dst = skb_dst(skb);