xref: /linux/include/net/inetpeer.h (revision 4bedea94545165364618d403d03b61d797acba0b)
1 /*
2  *		INETPEER - A storage for permanent information about peers
3  *
4  *  Version:	$Id: inetpeer.h,v 1.2 2002/01/12 07:54:56 davem Exp $
5  *
6  *  Authors:	Andrey V. Savochkin <saw@msu.ru>
7  */
8 
9 #ifndef _NET_INETPEER_H
10 #define _NET_INETPEER_H
11 
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/jiffies.h>
15 #include <linux/spinlock.h>
16 #include <asm/atomic.h>
17 
18 struct inet_peer
19 {
20 	struct inet_peer	*avl_left, *avl_right;
21 	struct inet_peer	*unused_next, **unused_prevp;
22 	unsigned long		dtime;		/* the time of last use of not
23 						 * referenced entries */
24 	atomic_t		refcnt;
25 	__u32			v4daddr;	/* peer's address */
26 	__u16			avl_height;
27 	__u16			ip_id_count;	/* IP ID for the next packet */
28 	__u32			tcp_ts;
29 	unsigned long		tcp_ts_stamp;
30 };
31 
32 void			inet_initpeers(void) __init;
33 
34 /* can be called with or without local BH being disabled */
35 struct inet_peer	*inet_getpeer(__u32 daddr, int create);
36 
37 extern spinlock_t inet_peer_unused_lock;
38 extern struct inet_peer **inet_peer_unused_tailp;
39 /* can be called from BH context or outside */
40 static inline void	inet_putpeer(struct inet_peer *p)
41 {
42 	spin_lock_bh(&inet_peer_unused_lock);
43 	if (atomic_dec_and_test(&p->refcnt)) {
44 		p->unused_prevp = inet_peer_unused_tailp;
45 		p->unused_next = NULL;
46 		*inet_peer_unused_tailp = p;
47 		inet_peer_unused_tailp = &p->unused_next;
48 		p->dtime = jiffies;
49 	}
50 	spin_unlock_bh(&inet_peer_unused_lock);
51 }
52 
53 extern spinlock_t inet_peer_idlock;
54 /* can be called with or without local BH being disabled */
55 static inline __u16	inet_getid(struct inet_peer *p, int more)
56 {
57 	__u16 id;
58 
59 	spin_lock_bh(&inet_peer_idlock);
60 	id = p->ip_id_count;
61 	p->ip_id_count += 1 + more;
62 	spin_unlock_bh(&inet_peer_idlock);
63 	return id;
64 }
65 
66 #endif /* _NET_INETPEER_H */
67