Initial import

1 files changed, 179 insertions, 0 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
new file mode 100644
index 000000000..8d1765577
--- /dev/null
+++ b/include/net/inet_frag.h
@@ -0,0 +1,179 @@
+#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;
+
+	/* sysctls */
+	int			timeout;
+	int			high_thresh;
+	int			low_thresh;
+};
+
+/**
+ * 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_EVICTED: frag queue is being evicted
+ */
+enum {
+	INET_FRAG_FIRST_IN	= BIT(0),
+	INET_FRAG_LAST_IN	= BIT(1),
+	INET_FRAG_COMPLETE	= BIT(2),
+	INET_FRAG_EVICTED	= BIT(3)
+};
+
+/**
+ * struct inet_frag_queue - fragment queue
+ *
+ * @lock: spinlock protecting the queue
+ * @timer: queue expiration timer
+ * @list: hash bucket list
+ * @refcnt: reference count of the queue
+ * @fragments: received fragments head
+ * @fragments_tail: received fragments tail
+ * @stamp: timestamp of the last received fragment
+ * @len: total length of the original datagram
+ * @meat: length of received fragments so far
+ * @flags: fragment queue flags
+ * @max_size: (ipv4 only) maximum received fragment size with IP_DF set
+ * @net: namespace that this frag belongs to
+ */
+struct inet_frag_queue {
+	spinlock_t		lock;
+	struct timer_list	timer;
+	struct hlist_node	list;
+	atomic_t		refcnt;
+	struct sk_buff		*fragments;
+	struct sk_buff		*fragments_tail;
+	ktime_t			stamp;
+	int			len;
+	int			meat;
+	__u8			flags;
+	u16			max_size;
+	struct netns_frags	*net;
+};
+
+#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 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;
+	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			(*skb_free)(struct sk_buff *);
+	void			(*frag_expire)(unsigned long data);
+	struct kmem_cache	*frags_cachep;
+	const char		*frags_cache_name;
+};
+
+int inet_frags_init(struct inet_frags *);
+void inet_frags_fini(struct inet_frags *);
+
+void inet_frags_init_net(struct netns_frags *nf);
+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)
+{
+	if (atomic_dec_and_test(&q->refcnt))
+		inet_frag_destroy(q, f);
+}
+
+/* Memory Tracking Functions. */
+
+/* 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;
+
+static inline int frag_mem_limit(struct netns_frags *nf)
+{
+	return percpu_counter_read(&nf->mem);
+}
+
+static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i)
+{
+	__percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch);
+}
+
+static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
+{
+	__percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch);
+}
+
+static inline void init_frag_mem_limit(struct netns_frags *nf)
+{
+	percpu_counter_init(&nf->mem, 0, GFP_KERNEL);
+}
+
+static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
+{
+	unsigned int res;
+
+	local_bh_disable();
+	res = percpu_counter_sum_positive(&nf->mem);
+	local_bh_enable();
+
+	return res;
+}
+
+/* RFC 3168 support :
+ * We want to check ECN values of all fragments, do detect invalid combinations.
+ * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
+ */
+#define	IPFRAG_ECN_NOT_ECT	0x01 /* one frag had ECN_NOT_ECT */
+#define	IPFRAG_ECN_ECT_1	0x02 /* one frag had ECN_ECT_1 */
+#define	IPFRAG_ECN_ECT_0	0x04 /* one frag had ECN_ECT_0 */
+#define	IPFRAG_ECN_CE		0x08 /* one frag had ECN_CE */
+
+extern const u8 ip_frag_ecn_table[16];
+
+#endif