1/*
2 *		INETPEER - A storage for permanent information about peers
3 *
4 *  Version:	$Id: inetpeer.h,v 1.1.1.1 2008/10/15 03:29:28 james26_jang 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/sched.h>
15#include <linux/spinlock.h>
16#include <asm/atomic.h>
17
18struct inet_peer
19{
20	struct inet_peer	*avl_left, *avl_right;
21	struct inet_peer	*unused_next, **unused_prevp;
22	atomic_t		refcnt;
23	unsigned long		dtime;		/* the time of last use of not
24						 * referenced entries */
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
32void			inet_initpeers(void) __init;
33
34/* can be called with or without local BH being disabled */
35struct inet_peer	*inet_getpeer(__u32 daddr, int create);
36
37extern spinlock_t inet_peer_unused_lock;
38extern struct inet_peer *inet_peer_unused_head;
39extern struct inet_peer **inet_peer_unused_tailp;
40/* can be called from BH context or outside */
41static inline void	inet_putpeer(struct inet_peer *p)
42{
43	spin_lock_bh(&inet_peer_unused_lock);
44	if (atomic_dec_and_test(&p->refcnt)) {
45		p->unused_prevp = inet_peer_unused_tailp;
46		p->unused_next = NULL;
47		*inet_peer_unused_tailp = p;
48		inet_peer_unused_tailp = &p->unused_next;
49		p->dtime = jiffies;
50	}
51	spin_unlock_bh(&inet_peer_unused_lock);
52}
53
54extern spinlock_t inet_peer_idlock;
55/* can be called with or without local BH being disabled */
56static inline __u16	inet_getid(struct inet_peer *p)
57{
58	__u16 id;
59
60	spin_lock_bh(&inet_peer_idlock);
61	id = p->ip_id_count++;
62	spin_unlock_bh(&inet_peer_idlock);
63	return id;
64}
65
66#endif /* _NET_INETPEER_H */
67