[linux-block.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 <linux/rtnetlink.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, metrics
	 * We can share memory with rcu_head to help 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;
			u32		metrics[RTAX_MAX];
			u32		rate_tokens;	/* rate limiting for ICMP */
			unsigned long	rate_last;
		};
		struct rcu_head         rcu;
	};
};

void			inet_initpeers(void) __init;

#define INETPEER_METRICS_NEW	(~(u32) 0)

static inline bool inet_metrics_new(const struct inet_peer *p)
{
	return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
}

/* 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);
extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);

/*
 * 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>
60659823	14	#include <linux/rtnetlink.h>
672f007d	15	#include <net/ipv6.h>
1da177e4 LT	16	#include <asm/atomic.h>
1da177e4 LT	17
8790ca17	18	struct inetpeer_addr {
582a72da DM	19	union {
	20	__be32 a4;
	21	__be32 a6[4];
	22	};
	23	__u16 family;
8790ca17	24	};
582a72da	25
fd2c3ef7	26	struct inet_peer {
78d79423	27	/* group together avl_left,avl_right,v4daddr to speedup lookups */
b914c4ea	28	struct inet_peer __rcu avl_left, avl_right;
8790ca17	29	struct inetpeer_addr daddr;
2c1409a0	30	__u32 avl_height;
d71209de	31	struct list_head unused;
4663afe2	32	__u32 dtime; /* the time of last use of not
1da177e4 LT	33	* referenced entries */
1da177e4 LT	34	atomic_t refcnt;
317fe0e6 ED	35	/*
317fe0e6 ED	36	* Once inet_peer is queued for deletion (refcnt == -1), following fields
60659823 DM	37	* are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp, metrics
60659823 DM	38	* We can share memory with rcu_head to help keep inet_peer small.
317fe0e6 ED	39	*/
	40	union {
	41	struct {
	42	atomic_t rid; /* Frag reception counter */
	43	atomic_t ip_id_count; /* IP ID for the next packet */
	44	__u32 tcp_ts;
	45	__u32 tcp_ts_stamp;
60659823	46	u32 metrics[RTAX_MAX];
92d86829 DM	47	u32 rate_tokens; /* rate limiting for ICMP */
92d86829 DM	48	unsigned long rate_last;
317fe0e6 ED	49	};
	50	struct rcu_head rcu;
	51	};
1da177e4 LT	52	};
	53
	54	void inet_initpeers(void) __init;
	55
144001bd DM	56	#define INETPEER_METRICS_NEW (~(u32) 0)
	57
	58	static inline bool inet_metrics_new(const struct inet_peer *p)
	59	{
	60	return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
	61	}
	62
1da177e4	63	/* can be called with or without local BH being disabled */
8790ca17	64	struct inet_peer inet_getpeer(struct inetpeer_addr daddr, int create);
b534ecf1 DM	65
	66	static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create)
	67	{
8790ca17	68	struct inetpeer_addr daddr;
b534ecf1 DM	69
	70	daddr.a4 = v4daddr;
	71	daddr.family = AF_INET;
	72	return inet_getpeer(&daddr, create);
	73	}
1da177e4	74
672f007d DM	75	static inline struct inet_peer inet_getpeer_v6(struct in6_addr v6daddr, int create)
672f007d DM	76	{
8790ca17	77	struct inetpeer_addr daddr;
672f007d DM	78
	79	ipv6_addr_copy((struct in6_addr *)daddr.a6, v6daddr);
	80	daddr.family = AF_INET6;
	81	return inet_getpeer(&daddr, create);
	82	}
	83
1da177e4	84	/* can be called from BH context or outside */
4663afe2	85	extern void inet_putpeer(struct inet_peer *p);
92d86829	86	extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
1da177e4	87
317fe0e6 ED	88	/*
	89	* temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
	90	* tcp_ts_stamp if no refcount is taken on inet_peer
	91	*/
	92	static inline void inet_peer_refcheck(const struct inet_peer *p)
	93	{
	94	WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
	95	}
	96
	97
1da177e4 LT	98	/* can be called with or without local BH being disabled */
	99	static inline __u16 inet_getid(struct inet_peer *p, int more)
	100	{
2c1409a0	101	more++;
317fe0e6	102	inet_peer_refcheck(p);
2c1409a0	103	return atomic_add_return(more, &p->ip_id_count) - more;
1da177e4 LT	104	}
	105
	106	#endif /* _NET_INETPEER_H */