1 files changed, 106 insertions, 93 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 6fdcd2427776..0eccd9c3a883 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -1,170 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __NET_FRAG_H__
 #define __NET_FRAG_H__
 
-#include <linux/percpu_counter.h>
-
-struct netns_frags {
-	/* The percpu_counter "mem" need to be cacheline aligned.
-	 *  mem.count must not share cacheline with other writers
-	 */
-	struct percpu_counter   mem ____cacheline_aligned_in_smp;
+#include <linux/rhashtable-types.h>
+#include <linux/completion.h>
+#include <linux/in6.h>
+#include <linux/rbtree_types.h>
+#include <linux/refcount.h>
+#include <net/dropreason-core.h>
 
+/* Per netns frag queues directory */
+struct fqdir {
 	/* sysctls */
+	long			high_thresh;
+	long			low_thresh;
 	int			timeout;
-	int			high_thresh;
-	int			low_thresh;
 	int			max_dist;
+	struct inet_frags	*f;
+	struct net		*net;
+	bool			dead;
+
+	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
+
+	/* Keep atomic mem on separate cachelines in structs that include it */
+	atomic_long_t		mem ____cacheline_aligned_in_smp;
+	struct work_struct	destroy_work;
+	struct llist_node	free_list;
 };
 
 /**
- * fragment queue flags
+ * enum: fragment queue flags
  *
  * @INET_FRAG_FIRST_IN: first fragment has arrived
  * @INET_FRAG_LAST_IN: final fragment has arrived
  * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction
+ * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable
+ * @INET_FRAG_DROP: if skbs must be dropped (instead of being consumed)
  */
 enum {
 	INET_FRAG_FIRST_IN	= BIT(0),
 	INET_FRAG_LAST_IN	= BIT(1),
 	INET_FRAG_COMPLETE	= BIT(2),
+	INET_FRAG_HASH_DEAD	= BIT(3),
+	INET_FRAG_DROP		= BIT(4),
+};
+
+struct frag_v4_compare_key {
+	__be32		saddr;
+	__be32		daddr;
+	u32		user;
+	u32		vif;
+	__be16		id;
+	u16		protocol;
+};
+
+struct frag_v6_compare_key {
+	struct in6_addr	saddr;
+	struct in6_addr	daddr;
+	u32		user;
+	__be32		id;
+	u32		iif;
 };
 
 /**
  * struct inet_frag_queue - fragment queue
  *
- * @lock: spinlock protecting the queue
+ * @node: rhash node
+ * @key: keys identifying this frag.
  * @timer: queue expiration timer
- * @list: hash bucket list
+ * @lock: spinlock protecting this frag
  * @refcnt: reference count of the queue
- * @fragments: received fragments head
+ * @rb_fragments: received fragments rb-tree root
  * @fragments_tail: received fragments tail
+ * @last_run_head: the head of the last "run". see ip_fragment.c
  * @stamp: timestamp of the last received fragment
  * @len: total length of the original datagram
  * @meat: length of received fragments so far
+ * @tstamp_type: stamp has a mono delivery time (EDT)
  * @flags: fragment queue flags
  * @max_size: maximum received fragment size
- * @net: namespace that this frag belongs to
- * @list_evictor: list of queues to forcefully evict (e.g. due to low memory)
+ * @fqdir: pointer to struct fqdir
+ * @rcu: rcu head for freeing deferall
  */
 struct inet_frag_queue {
-	spinlock_t		lock;
+	struct rhash_head	node;
+	union {
+		struct frag_v4_compare_key v4;
+		struct frag_v6_compare_key v6;
+	} key;
 	struct timer_list	timer;
-	struct hlist_node	list;
+	spinlock_t		lock;
 	refcount_t		refcnt;
-	struct sk_buff		*fragments;
+	struct rb_root		rb_fragments;
 	struct sk_buff		*fragments_tail;
+	struct sk_buff		*last_run_head;
 	ktime_t			stamp;
 	int			len;
 	int			meat;
+	u8			tstamp_type;
 	__u8			flags;
 	u16			max_size;
-	struct netns_frags	*net;
-	struct hlist_node	list_evictor;
-};
-
-#define INETFRAGS_HASHSZ	1024
-
-/* averaged:
- * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ /
- *	       rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or
- *	       struct frag_queue))
- */
-#define INETFRAGS_MAXDEPTH	128
-
-struct inet_frag_bucket {
-	struct hlist_head	chain;
-	spinlock_t		chain_lock;
+	struct fqdir		*fqdir;
+	struct rcu_head		rcu;
 };
 
 struct inet_frags {
-	struct inet_frag_bucket	hash[INETFRAGS_HASHSZ];
-
-	struct work_struct	frags_work;
-	unsigned int next_bucket;
-	unsigned long last_rebuild_jiffies;
-	bool rebuild;
-
-	/* The first call to hashfn is responsible to initialize
-	 * rnd. This is best done with net_get_random_once.
-	 *
-	 * rnd_seqlock is used to let hash insertion detect
-	 * when it needs to re-lookup the hash chain to use.
-	 */
-	u32			rnd;
-	seqlock_t		rnd_seqlock;
 	unsigned int		qsize;
 
-	unsigned int		(*hashfn)(const struct inet_frag_queue *);
-	bool			(*match)(const struct inet_frag_queue *q,
-					 const void *arg);
 	void			(*constructor)(struct inet_frag_queue *q,
 					       const void *arg);
 	void			(*destructor)(struct inet_frag_queue *);
-	void			(*frag_expire)(unsigned long data);
+	void			(*frag_expire)(struct timer_list *t);
 	struct kmem_cache	*frags_cachep;
 	const char		*frags_cache_name;
+	struct rhashtable_params rhash_params;
+	refcount_t		refcnt;
+	struct completion	completion;
 };
 
 int inet_frags_init(struct inet_frags *);
 void inet_frags_fini(struct inet_frags *);
 
-static inline int inet_frags_init_net(struct netns_frags *nf)
-{
-	return percpu_counter_init(&nf->mem, 0, GFP_KERNEL);
-}
-static inline void inet_frags_uninit_net(struct netns_frags *nf)
-{
-	percpu_counter_destroy(&nf->mem);
-}
+int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net);
 
-void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
-
-void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
-void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f);
-struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
-		struct inet_frags *f, void *key, unsigned int hash);
-
-void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
-				   const char *prefix);
-
-static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
+static inline void fqdir_pre_exit(struct fqdir *fqdir)
 {
-	if (refcount_dec_and_test(&q->refcnt))
-		inet_frag_destroy(q, f);
-}
+	/* Prevent creation of new frags.
+	 * Pairs with READ_ONCE() in inet_frag_find().
+	 */
+	WRITE_ONCE(fqdir->high_thresh, 0);
 
-static inline bool inet_frag_evicting(struct inet_frag_queue *q)
-{
-	return !hlist_unhashed(&q->list_evictor);
+	/* Pairs with READ_ONCE() in inet_frag_kill(), ip_expire()
+	 * and ip6frag_expire_frag_queue().
+	 */
+	WRITE_ONCE(fqdir->dead, true);
 }
+void fqdir_exit(struct fqdir *fqdir);
 
-/* Memory Tracking Functions. */
+void inet_frag_kill(struct inet_frag_queue *q, int *refs);
+void inet_frag_destroy(struct inet_frag_queue *q);
+struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);
 
-/* The default percpu_counter batch size is not big enough to scale to
- * fragmentation mem acct sizes.
- * The mem size of a 64K fragment is approx:
- *  (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes
- */
-static unsigned int frag_percpu_counter_batch = 130000;
+/* Free all skbs in the queue; return the sum of their truesizes. */
+unsigned int inet_frag_rbtree_purge(struct rb_root *root,
+				    enum skb_drop_reason reason);
 
-static inline int frag_mem_limit(struct netns_frags *nf)
+static inline void inet_frag_putn(struct inet_frag_queue *q, int refs)
 {
-	return percpu_counter_read(&nf->mem);
+	if (refs && refcount_sub_and_test(refs, &q->refcnt))
+		inet_frag_destroy(q);
 }
 
-static inline void sub_frag_mem_limit(struct netns_frags *nf, int i)
+/* Memory Tracking Functions. */
+
+static inline long frag_mem_limit(const struct fqdir *fqdir)
 {
-	percpu_counter_add_batch(&nf->mem, -i, frag_percpu_counter_batch);
+	return atomic_long_read(&fqdir->mem);
 }
 
-static inline void add_frag_mem_limit(struct netns_frags *nf, int i)
+static inline void sub_frag_mem_limit(struct fqdir *fqdir, long val)
 {
-	percpu_counter_add_batch(&nf->mem, i, frag_percpu_counter_batch);
+	atomic_long_sub(val, &fqdir->mem);
 }
 
-static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
+static inline void add_frag_mem_limit(struct fqdir *fqdir, long val)
 {
-	return percpu_counter_sum_positive(&nf->mem);
+	atomic_long_add(val, &fqdir->mem);
 }
 
 /* RFC 3168 support :
@@ -178,4 +179,16 @@ static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
 
 extern const u8 ip_frag_ecn_table[16];
 
+/* Return values of inet_frag_queue_insert() */
+#define IPFRAG_OK	0
+#define IPFRAG_DUP	1
+#define IPFRAG_OVERLAP	2
+int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
+			   int offset, int end);
+void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
+			      struct sk_buff *parent);
+void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
+			    void *reasm_data, bool try_coalesce);
+struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
+
 #endif