linux-stable/include/net/inetpeer.h
Herbert Xu 89cee8b1cb [IPV4]: Safer reassembly
Another spin of Herbert Xu's "safer ip reassembly" patch
for 2.6.16.

(The original patch is here:
http://marc.theaimsgroup.com/?l=linux-netdev&m=112281936522415&w=2
and my only contribution is to have tested it.)

This patch (optionally) does additional checks before accepting IP
fragments, which can greatly reduce the possibility of reassembling
fragments which originated from different IP datagrams.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:31 -08:00

67 lines
1.7 KiB
C

/*
* INETPEER - A storage for permanent information about peers
*
* Version: $Id: inetpeer.h,v 1.2 2002/01/12 07:54:56 davem Exp $
*
* 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
{
struct inet_peer *avl_left, *avl_right;
struct inet_peer *unused_next, **unused_prevp;
unsigned long dtime; /* the time of last use of not
* referenced entries */
atomic_t refcnt;
__u32 v4daddr; /* peer's address */
__u16 avl_height;
__u16 ip_id_count; /* IP ID for the next packet */
atomic_t rid; /* Frag reception counter */
__u32 tcp_ts;
unsigned long tcp_ts_stamp;
};
void inet_initpeers(void) __init;
/* can be called with or without local BH being disabled */
struct inet_peer *inet_getpeer(__u32 daddr, int create);
extern spinlock_t inet_peer_unused_lock;
extern struct inet_peer **inet_peer_unused_tailp;
/* can be called from BH context or outside */
static inline void inet_putpeer(struct inet_peer *p)
{
spin_lock_bh(&inet_peer_unused_lock);
if (atomic_dec_and_test(&p->refcnt)) {
p->unused_prevp = inet_peer_unused_tailp;
p->unused_next = NULL;
*inet_peer_unused_tailp = p;
inet_peer_unused_tailp = &p->unused_next;
p->dtime = jiffies;
}
spin_unlock_bh(&inet_peer_unused_lock);
}
extern spinlock_t inet_peer_idlock;
/* can be called with or without local BH being disabled */
static inline __u16 inet_getid(struct inet_peer *p, int more)
{
__u16 id;
spin_lock_bh(&inet_peer_idlock);
id = p->ip_id_count;
p->ip_id_count += 1 + more;
spin_unlock_bh(&inet_peer_idlock);
return id;
}
#endif /* _NET_INETPEER_H */