69 строки
1.8 KiB
C
69 строки
1.8 KiB
C
/*
|
|
* 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 <asm/atomic.h>
|
|
|
|
struct inet_peer {
|
|
/* group together avl_left,avl_right,v4daddr to speedup lookups */
|
|
struct inet_peer __rcu *avl_left, *avl_right;
|
|
__be32 v4daddr; /* peer's address */
|
|
__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
|
|
* (less then 64 bytes)
|
|
*/
|
|
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(__be32 daddr, int 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 */
|