Merge branch 'ip-Use-rb-trees-for-IP-frag-queue'

Peter Oskolkov says:

====================
ip: Use rb trees for IP frag queue.

This patchset
 * changes IPv4 defrag behavior to match that of IPv6: overlapping
   fragments now cause the whole IP datagram to be discarded (suggested
   by David Miller): there are no legitimate use cases for overlapping
   fragments;
 * changes IPv4 defrag queue from a list to a rb tree (suggested
   by Eric Dumazet): this change removes a potential attach vector.

Upcoming patches will contain similar changes for IPv6 frag queue,
as well as a comprehensive IP defrag self-test (temporarily delayed).
====================

Signed-off-by: David S. Miller <[email protected]>

1 files changed, 7 insertions, 4 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index fd3cb1b247df..7ebdf158a795 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -676,13 +676,16 @@ struct sk_buff {
 				 * UDP receive path is one user.
 				 */
 				unsigned long		dev_scratch;
-				int			ip_defrag_offset;
 			};
 		};
-		struct rb_node		rbnode; /* used in netem & tcp stack */
+		struct rb_node		rbnode; /* used in netem, ip4 defrag, and tcp stack */
 		struct list_head	list;
 	};
-	struct sock		*sk;
+
+	union {
+		struct sock		*sk;
+		int			ip_defrag_offset;
+	};
 
 	union {
 		ktime_t		tstamp;
@@ -2585,7 +2588,7 @@ static inline void __skb_queue_purge(struct sk_buff_head *list)
 		kfree_skb(skb);
 }
 
-void skb_rbtree_purge(struct rb_root *root);
+unsigned int skb_rbtree_purge(struct rb_root *root);
 
 void *netdev_alloc_frag(unsigned int fragsz);