net: Add skb_queue_next().

A lot of code wants to iterate over an SKB queue at the top level using
it's own control structure and iterator scheme.

Provide skb_queue_next(), which is only valid to invoke if
skb_queue_is_last() returns false.

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

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3a5838da160e..d2f1778877d7 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -486,6 +486,24 @@ static inline bool skb_queue_is_last(const struct sk_buff_head *list,
 }
 
 /**
+ *      skb_queue_next - return the next packet in the queue
+ *      @list: queue head
+ *      @skb: current buffer
+ *
+ *      Return the next packet in @list after @skb.  It is only valid to
+ *      call this if skb_queue_is_last() evaluates to false.
+ */
+static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
+                                             const struct sk_buff *skb)
+{
+        /* This BUG_ON may seem severe, but if we just return then we
+         * are going to dereference garbage.
+         */
+        BUG_ON(skb_queue_is_last(list, skb));
+        return skb->next;
+}
+
+/**
  *      skb_get - reference buffer
  *      @skb: buffer to reference
  *