[deliverable/linux.git] / include / net / inetpeer.h

/*
 *		INETPEER - A storage for permanent information about peers
 *
 *  Authors:	Andrey V. Savochkin <saw@msu.ru>
 */

#ifndef _NET_INETPEER_H
#define _NET_INETPEER_H

#include <linux/types.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <net/ipv6.h>
#include <asm/atomic.h>

struct inetpeer_addr {
	union {
		__be32		a4;
		__be32		a6[4];
	};
	__u16	family;
};

struct inet_peer {
	/* group together avl_left,avl_right,v4daddr to speedup lookups */
	struct inet_peer __rcu	*avl_left, *avl_right;
	struct inetpeer_addr	daddr;
	__u32			avl_height;
	struct list_head	unused;
	__u32			dtime;		/* the time of last use of not
						 * referenced entries */
	atomic_t		refcnt;
	/*
	 * Once inet_peer is queued for deletion (refcnt == -1), following fields
	 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp
	 * We can share memory with rcu_head to keep inet_peer small
	 */
	union {
		struct {
			atomic_t	rid;		/* Frag reception counter */
			atomic_t	ip_id_count;	/* IP ID for the next packet */
			__u32		tcp_ts;
			__u32		tcp_ts_stamp;
		};
		struct rcu_head         rcu;
	};
};

void			inet_initpeers(void) __init;

/* can be called with or without local BH being disabled */
struct inet_peer	*inet_getpeer(struct inetpeer_addr *daddr, int create);

static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create)
{
	struct inetpeer_addr daddr;

	daddr.a4 = v4daddr;
	daddr.family = AF_INET;
	return inet_getpeer(&daddr, create);
}

static inline struct inet_peer *inet_getpeer_v6(struct in6_addr *v6daddr, int create)
{
	struct inetpeer_addr daddr;

	ipv6_addr_copy((struct in6_addr *)daddr.a6, v6daddr);
	daddr.family = AF_INET6;
	return inet_getpeer(&daddr, create);
}

/* can be called from BH context or outside */
extern void inet_putpeer(struct inet_peer *p);

/*
 * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
 * tcp_ts_stamp if no refcount is taken on inet_peer
 */
static inline void inet_peer_refcheck(const struct inet_peer *p)
{
	WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
}


/* can be called with or without local BH being disabled */
static inline __u16	inet_getid(struct inet_peer *p, int more)
{
	more++;
	inet_peer_refcheck(p);
	return atomic_add_return(more, &p->ip_id_count) - more;
}

#endif /* _NET_INETPEER_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INETPEER - A storage for permanent information about peers
	3	*
1da177e4 LT	4	* Authors: Andrey V. Savochkin <saw@msu.ru>
	5	*/
	6
	7	#ifndef _NET_INETPEER_H
	8	#define _NET_INETPEER_H
	9
	10	#include <linux/types.h>
	11	#include <linux/init.h>
	12	#include <linux/jiffies.h>
	13	#include <linux/spinlock.h>
672f007d	14	#include <net/ipv6.h>
1da177e4 LT	15	#include <asm/atomic.h>
1da177e4 LT	16
8790ca17	17	struct inetpeer_addr {
582a72da DM	18	union {
	19	__be32 a4;
	20	__be32 a6[4];
	21	};
	22	__u16 family;
8790ca17	23	};
582a72da	24
fd2c3ef7	25	struct inet_peer {
78d79423	26	/* group together avl_left,avl_right,v4daddr to speedup lookups */
b914c4ea	27	struct inet_peer __rcu avl_left, avl_right;
8790ca17	28	struct inetpeer_addr daddr;
2c1409a0	29	__u32 avl_height;
d71209de	30	struct list_head unused;
4663afe2	31	__u32 dtime; /* the time of last use of not
1da177e4 LT	32	* referenced entries */
1da177e4 LT	33	atomic_t refcnt;
317fe0e6 ED	34	/*
	35	* Once inet_peer is queued for deletion (refcnt == -1), following fields
	36	* are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp
	37	* We can share memory with rcu_head to keep inet_peer small
317fe0e6 ED	38	*/
	39	union {
	40	struct {
	41	atomic_t rid; /* Frag reception counter */
	42	atomic_t ip_id_count; /* IP ID for the next packet */
	43	__u32 tcp_ts;
	44	__u32 tcp_ts_stamp;
	45	};
	46	struct rcu_head rcu;
	47	};
1da177e4 LT	48	};
	49
	50	void inet_initpeers(void) __init;
	51
	52	/* can be called with or without local BH being disabled */
8790ca17	53	struct inet_peer inet_getpeer(struct inetpeer_addr daddr, int create);
b534ecf1 DM	54
	55	static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create)
	56	{
8790ca17	57	struct inetpeer_addr daddr;
b534ecf1 DM	58
	59	daddr.a4 = v4daddr;
	60	daddr.family = AF_INET;
	61	return inet_getpeer(&daddr, create);
	62	}
1da177e4	63
672f007d DM	64	static inline struct inet_peer inet_getpeer_v6(struct in6_addr v6daddr, int create)
672f007d DM	65	{
8790ca17	66	struct inetpeer_addr daddr;
672f007d DM	67
	68	ipv6_addr_copy((struct in6_addr *)daddr.a6, v6daddr);
	69	daddr.family = AF_INET6;
	70	return inet_getpeer(&daddr, create);
	71	}
	72
1da177e4	73	/* can be called from BH context or outside */
4663afe2	74	extern void inet_putpeer(struct inet_peer *p);
1da177e4	75
317fe0e6 ED	76	/*
	77	* temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
	78	* tcp_ts_stamp if no refcount is taken on inet_peer
	79	*/
	80	static inline void inet_peer_refcheck(const struct inet_peer *p)
	81	{
	82	WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
	83	}
	84
	85
1da177e4 LT	86	/* can be called with or without local BH being disabled */
	87	static inline __u16 inet_getid(struct inet_peer *p, int more)
	88	{
2c1409a0	89	more++;
317fe0e6	90	inet_peer_refcheck(p);
2c1409a0	91	return atomic_add_return(more, &p->ip_id_count) - more;
1da177e4 LT	92	}
	93
	94	#endif /* _NET_INETPEER_H */