1 /* Event cache for netfilter. */
3 /* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
5 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/types.h>
13 #include <linux/netfilter.h>
14 #include <linux/skbuff.h>
15 #include <linux/vmalloc.h>
16 #include <linux/stddef.h>
17 #include <linux/err.h>
18 #include <linux/percpu.h>
19 #include <linux/kernel.h>
20 #include <linux/netdevice.h>
22 #include <net/netfilter/nf_conntrack.h>
23 #include <net/netfilter/nf_conntrack_core.h>
24 #include <net/netfilter/nf_conntrack_extend.h>
26 static DEFINE_MUTEX(nf_ct_ecache_mutex
);
28 struct nf_ct_event_notifier
*nf_conntrack_event_cb __read_mostly
;
29 EXPORT_SYMBOL_GPL(nf_conntrack_event_cb
);
31 struct nf_exp_event_notifier
*nf_expect_event_cb __read_mostly
;
32 EXPORT_SYMBOL_GPL(nf_expect_event_cb
);
34 /* deliver cached events and clear cache entry - must be called with locally
35 * disabled softirqs */
36 void nf_ct_deliver_cached_events(struct nf_conn
*ct
)
39 struct nf_ct_event_notifier
*notify
;
40 struct nf_conntrack_ecache
*e
;
43 notify
= rcu_dereference(nf_conntrack_event_cb
);
47 e
= nf_ct_ecache_find(ct
);
51 events
= xchg(&e
->cache
, 0);
53 if (nf_ct_is_confirmed(ct
) && !nf_ct_is_dying(ct
) && events
) {
54 struct nf_ct_event item
= {
60 /* We make a copy of the missed event cache without taking
61 * the lock, thus we may send missed events twice. However,
62 * this does not harm and it happens very rarely. */
63 unsigned long missed
= e
->missed
;
65 ret
= notify
->fcn(events
| missed
, &item
);
66 if (unlikely(ret
< 0 || missed
)) {
67 spin_lock_bh(&ct
->lock
);
72 spin_unlock_bh(&ct
->lock
);
79 EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events
);
81 int nf_conntrack_register_notifier(struct nf_ct_event_notifier
*new)
84 struct nf_ct_event_notifier
*notify
;
86 mutex_lock(&nf_ct_ecache_mutex
);
87 notify
= rcu_dereference(nf_conntrack_event_cb
);
92 rcu_assign_pointer(nf_conntrack_event_cb
, new);
93 mutex_unlock(&nf_ct_ecache_mutex
);
97 mutex_unlock(&nf_ct_ecache_mutex
);
100 EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier
);
102 void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier
*new)
104 struct nf_ct_event_notifier
*notify
;
106 mutex_lock(&nf_ct_ecache_mutex
);
107 notify
= rcu_dereference(nf_conntrack_event_cb
);
108 BUG_ON(notify
!= new);
109 rcu_assign_pointer(nf_conntrack_event_cb
, NULL
);
110 mutex_unlock(&nf_ct_ecache_mutex
);
112 EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier
);
114 int nf_ct_expect_register_notifier(struct nf_exp_event_notifier
*new)
117 struct nf_exp_event_notifier
*notify
;
119 mutex_lock(&nf_ct_ecache_mutex
);
120 notify
= rcu_dereference(nf_expect_event_cb
);
121 if (notify
!= NULL
) {
125 rcu_assign_pointer(nf_expect_event_cb
, new);
126 mutex_unlock(&nf_ct_ecache_mutex
);
130 mutex_unlock(&nf_ct_ecache_mutex
);
133 EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier
);
135 void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier
*new)
137 struct nf_exp_event_notifier
*notify
;
139 mutex_lock(&nf_ct_ecache_mutex
);
140 notify
= rcu_dereference(nf_expect_event_cb
);
141 BUG_ON(notify
!= new);
142 rcu_assign_pointer(nf_expect_event_cb
, NULL
);
143 mutex_unlock(&nf_ct_ecache_mutex
);
145 EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier
);
147 #define NF_CT_EVENTS_DEFAULT 1
148 static int nf_ct_events __read_mostly
= NF_CT_EVENTS_DEFAULT
;
149 static int nf_ct_events_retry_timeout __read_mostly
= 15*HZ
;
152 static struct ctl_table event_sysctl_table
[] = {
154 .procname
= "nf_conntrack_events",
155 .data
= &init_net
.ct
.sysctl_events
,
156 .maxlen
= sizeof(unsigned int),
158 .proc_handler
= proc_dointvec
,
161 .procname
= "nf_conntrack_events_retry_timeout",
162 .data
= &init_net
.ct
.sysctl_events_retry_timeout
,
163 .maxlen
= sizeof(unsigned int),
165 .proc_handler
= proc_dointvec_jiffies
,
169 #endif /* CONFIG_SYSCTL */
171 static struct nf_ct_ext_type event_extend __read_mostly
= {
172 .len
= sizeof(struct nf_conntrack_ecache
),
173 .align
= __alignof__(struct nf_conntrack_ecache
),
174 .id
= NF_CT_EXT_ECACHE
,
178 static int nf_conntrack_event_init_sysctl(struct net
*net
)
180 struct ctl_table
*table
;
182 table
= kmemdup(event_sysctl_table
, sizeof(event_sysctl_table
),
187 table
[0].data
= &net
->ct
.sysctl_events
;
188 table
[1].data
= &net
->ct
.sysctl_events_retry_timeout
;
190 net
->ct
.event_sysctl_header
=
191 register_net_sysctl_table(net
,
192 nf_net_netfilter_sysctl_path
, table
);
193 if (!net
->ct
.event_sysctl_header
) {
194 printk(KERN_ERR
"nf_ct_event: can't register to sysctl.\n");
205 static void nf_conntrack_event_fini_sysctl(struct net
*net
)
207 struct ctl_table
*table
;
209 table
= net
->ct
.event_sysctl_header
->ctl_table_arg
;
210 unregister_net_sysctl_table(net
->ct
.event_sysctl_header
);
214 static int nf_conntrack_event_init_sysctl(struct net
*net
)
219 static void nf_conntrack_event_fini_sysctl(struct net
*net
)
222 #endif /* CONFIG_SYSCTL */
224 int nf_conntrack_ecache_init(struct net
*net
)
228 net
->ct
.sysctl_events
= nf_ct_events
;
229 net
->ct
.sysctl_events_retry_timeout
= nf_ct_events_retry_timeout
;
231 if (net_eq(net
, &init_net
)) {
232 ret
= nf_ct_extend_register(&event_extend
);
234 printk(KERN_ERR
"nf_ct_event: Unable to register "
235 "event extension.\n");
236 goto out_extend_register
;
240 ret
= nf_conntrack_event_init_sysctl(net
);
247 if (net_eq(net
, &init_net
))
248 nf_ct_extend_unregister(&event_extend
);
253 void nf_conntrack_ecache_fini(struct net
*net
)
255 nf_conntrack_event_fini_sysctl(net
);
256 if (net_eq(net
, &init_net
))
257 nf_ct_extend_unregister(&event_extend
);