swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 492c2e476eac010962850006c49df326919b284c authored by Linus Torvalds on 12 May 2008, 00:09:41 UTC
Linux 2.6.26-rc2
Linux 2.6.26-rc2
Tip revision: 492c2e4
nf_conntrack_ecache.c
/* Event cache for netfilter. */
/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/netfilter.h>
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/stddef.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain);
EXPORT_SYMBOL_GPL(nf_conntrack_chain);
ATOMIC_NOTIFIER_HEAD(nf_ct_expect_chain);
EXPORT_SYMBOL_GPL(nf_ct_expect_chain);
DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache);
EXPORT_PER_CPU_SYMBOL_GPL(nf_conntrack_ecache);
/* deliver cached events and clear cache entry - must be called with locally
* disabled softirqs */
static inline void
__nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache)
{
if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct)
&& ecache->events)
atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events,
ecache->ct);
ecache->events = 0;
nf_ct_put(ecache->ct);
ecache->ct = NULL;
}
/* Deliver all cached events for a particular conntrack. This is called
* by code prior to async packet handling for freeing the skb */
void nf_ct_deliver_cached_events(const struct nf_conn *ct)
{
struct nf_conntrack_ecache *ecache;
local_bh_disable();
ecache = &__get_cpu_var(nf_conntrack_ecache);
if (ecache->ct == ct)
__nf_ct_deliver_cached_events(ecache);
local_bh_enable();
}
EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
/* Deliver cached events for old pending events, if current conntrack != old */
void __nf_ct_event_cache_init(struct nf_conn *ct)
{
struct nf_conntrack_ecache *ecache;
/* take care of delivering potentially old events */
ecache = &__get_cpu_var(nf_conntrack_ecache);
BUG_ON(ecache->ct == ct);
if (ecache->ct)
__nf_ct_deliver_cached_events(ecache);
/* initialize for this conntrack/packet */
ecache->ct = ct;
nf_conntrack_get(&ct->ct_general);
}
EXPORT_SYMBOL_GPL(__nf_ct_event_cache_init);
/* flush the event cache - touches other CPU's data and must not be called
* while packets are still passing through the code */
void nf_ct_event_cache_flush(void)
{
struct nf_conntrack_ecache *ecache;
int cpu;
for_each_possible_cpu(cpu) {
ecache = &per_cpu(nf_conntrack_ecache, cpu);
if (ecache->ct)
nf_ct_put(ecache->ct);
}
}
int nf_conntrack_register_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&nf_conntrack_chain, nb);
}
EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier);
int nf_conntrack_unregister_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&nf_conntrack_chain, nb);
}
EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier);
int nf_ct_expect_register_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&nf_ct_expect_chain, nb);
}
EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier);
int nf_ct_expect_unregister_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&nf_ct_expect_chain, nb);
}
EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);