/* *		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 <linux/atomic.h> struct inetpeer_addr_base {	union {		__be32			a4;		__be32			a6[4];	};}; struct inetpeer_addr {	struct inetpeer_addr_base	addr;	__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; 	u32			metrics[RTAX_MAX];	u32			rate_tokens;	/* rate limiting for ICMP */	unsigned long		rate_last;	unsigned long		pmtu_expires;	u32			pmtu_orig;	u32			pmtu_learned;	struct inetpeer_addr_base redirect_learned;	/*	 * 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 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;		};		struct rcu_head         rcu;		struct inet_peer	*gc_next;	}; 	/* following fields might be frequently dirtied */	__u32			dtime;	/* the time of last use of not referenced entries */	atomic_t		refcnt;}; 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(const struct inetpeer_addr *daddr, int create); static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create){	struct inetpeer_addr daddr; 	daddr.addr.a4 = v4daddr;	daddr.family = AF_INET;	return inet_getpeer(&daddr, create);} static inline struct inet_peer *inet_getpeer_v6(const struct in6_addr *v6daddr, int create){	struct inetpeer_addr daddr; 	ipv6_addr_copy((struct in6_addr *)daddr.addr.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 int inet_getid(struct inet_peer *p, int more){	int old, new;	more++;	inet_peer_refcheck(p);	do {		old = atomic_read(&p->ip_id_count);		new = old + more;		if (!new)			new = 1;	} while (atomic_cmpxchg(&p->ip_id_count, old, new) != old);	return new;} #endif /* _NET_INETPEER_H */