xref: /linux/include/net/inet_frag.h (revision 98366c20a275e957416e9516db5dcb7195b4e101)
1 #ifndef __NET_FRAG_H__
2 #define __NET_FRAG_H__
3 
4 struct inet_frag_queue {
5 	struct hlist_node	list;
6 	struct list_head	lru_list;   /* lru list member */
7 	spinlock_t		lock;
8 	atomic_t		refcnt;
9 	struct timer_list	timer;      /* when will this queue expire? */
10 	struct sk_buff		*fragments; /* list of received fragments */
11 	ktime_t			stamp;
12 	int			len;        /* total length of orig datagram */
13 	int			meat;
14 	__u8			last_in;    /* first/last segment arrived? */
15 
16 #define COMPLETE		4
17 #define FIRST_IN		2
18 #define LAST_IN			1
19 };
20 
21 #define INETFRAGS_HASHSZ		64
22 
23 struct inet_frags_ctl {
24 	int high_thresh;
25 	int low_thresh;
26 	int timeout;
27 	int secret_interval;
28 };
29 
30 struct inet_frags {
31 	struct list_head	lru_list;
32 	struct hlist_head	hash[INETFRAGS_HASHSZ];
33 	rwlock_t		lock;
34 	u32			rnd;
35 	int			nqueues;
36 	int			qsize;
37 	atomic_t		mem;
38 	struct timer_list	secret_timer;
39 	struct inet_frags_ctl	*ctl;
40 
41 	unsigned int		(*hashfn)(struct inet_frag_queue *);
42 	void			(*constructor)(struct inet_frag_queue *q,
43 						void *arg);
44 	void			(*destructor)(struct inet_frag_queue *);
45 	void			(*skb_free)(struct sk_buff *);
46 	int			(*match)(struct inet_frag_queue *q,
47 						void *arg);
48 	void			(*frag_expire)(unsigned long data);
49 };
50 
51 void inet_frags_init(struct inet_frags *);
52 void inet_frags_fini(struct inet_frags *);
53 
54 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
55 void inet_frag_destroy(struct inet_frag_queue *q,
56 				struct inet_frags *f, int *work);
57 int inet_frag_evictor(struct inet_frags *f);
58 struct inet_frag_queue *inet_frag_find(struct inet_frags *f, void *key,
59 		unsigned int hash);
60 
61 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
62 {
63 	if (atomic_dec_and_test(&q->refcnt))
64 		inet_frag_destroy(q, f, NULL);
65 }
66 
67 #endif
68