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 notify->fcn(events, &item);
66 EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events);
68 int nf_conntrack_register_notifier(struct nf_ct_event_notifier *new)
71 struct nf_ct_event_notifier *notify;
73 mutex_lock(&nf_ct_ecache_mutex);
74 notify = rcu_dereference(nf_conntrack_event_cb);
79 rcu_assign_pointer(nf_conntrack_event_cb, new);
80 mutex_unlock(&nf_ct_ecache_mutex);
84 mutex_unlock(&nf_ct_ecache_mutex);
87 EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier);
89 void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *new)
91 struct nf_ct_event_notifier *notify;
93 mutex_lock(&nf_ct_ecache_mutex);
94 notify = rcu_dereference(nf_conntrack_event_cb);
95 BUG_ON(notify != new);
96 rcu_assign_pointer(nf_conntrack_event_cb, NULL);
97 mutex_unlock(&nf_ct_ecache_mutex);
99 EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier);
101 int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *new)
104 struct nf_exp_event_notifier *notify;
106 mutex_lock(&nf_ct_ecache_mutex);
107 notify = rcu_dereference(nf_expect_event_cb);
108 if (notify != NULL) {
112 rcu_assign_pointer(nf_expect_event_cb, new);
113 mutex_unlock(&nf_ct_ecache_mutex);
117 mutex_unlock(&nf_ct_ecache_mutex);
120 EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier);
122 void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *new)
124 struct nf_exp_event_notifier *notify;
126 mutex_lock(&nf_ct_ecache_mutex);
127 notify = rcu_dereference(nf_expect_event_cb);
128 BUG_ON(notify != new);
129 rcu_assign_pointer(nf_expect_event_cb, NULL);
130 mutex_unlock(&nf_ct_ecache_mutex);
132 EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier);
134 #define NF_CT_EVENTS_DEFAULT 1
135 static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT;
138 static struct ctl_table event_sysctl_table[] = {
140 .ctl_name = CTL_UNNUMBERED,
141 .procname = "nf_conntrack_events",
142 .data = &init_net.ct.sysctl_events,
143 .maxlen = sizeof(unsigned int),
145 .proc_handler = proc_dointvec,
149 #endif /* CONFIG_SYSCTL */
151 static struct nf_ct_ext_type event_extend __read_mostly = {
152 .len = sizeof(struct nf_conntrack_ecache),
153 .align = __alignof__(struct nf_conntrack_ecache),
154 .id = NF_CT_EXT_ECACHE,
158 static int nf_conntrack_event_init_sysctl(struct net *net)
160 struct ctl_table *table;
162 table = kmemdup(event_sysctl_table, sizeof(event_sysctl_table),
167 table[0].data = &net->ct.sysctl_events;
169 net->ct.event_sysctl_header =
170 register_net_sysctl_table(net,
171 nf_net_netfilter_sysctl_path, table);
172 if (!net->ct.event_sysctl_header) {
173 printk(KERN_ERR "nf_ct_event: can't register to sysctl.\n");
184 static void nf_conntrack_event_fini_sysctl(struct net *net)
186 struct ctl_table *table;
188 table = net->ct.event_sysctl_header->ctl_table_arg;
189 unregister_net_sysctl_table(net->ct.event_sysctl_header);
193 static int nf_conntrack_event_init_sysctl(struct net *net)
198 static void nf_conntrack_event_fini_sysctl(struct net *net)
201 #endif /* CONFIG_SYSCTL */
203 int nf_conntrack_ecache_init(struct net *net)
207 net->ct.sysctl_events = nf_ct_events;
209 if (net_eq(net, &init_net)) {
210 ret = nf_ct_extend_register(&event_extend);
212 printk(KERN_ERR "nf_ct_event: Unable to register "
213 "event extension.\n");
214 goto out_extend_register;
218 ret = nf_conntrack_event_init_sysctl(net);
225 if (net_eq(net, &init_net))
226 nf_ct_extend_unregister(&event_extend);
231 void nf_conntrack_ecache_fini(struct net *net)
233 nf_conntrack_event_fini_sysctl(net);
234 if (net_eq(net, &init_net))
235 nf_ct_extend_unregister(&event_extend);