Commit | Line | Data |
---|---|---|
f6180121 MJ |
1 | /* Event cache for netfilter. */ |
2 | ||
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> | |
6 | * | |
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. | |
10 | */ | |
11 | ||
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> | |
f6180121 MJ |
19 | #include <linux/kernel.h> |
20 | #include <linux/netdevice.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
f6180121 MJ |
22 | |
23 | #include <net/netfilter/nf_conntrack.h> | |
f6180121 | 24 | #include <net/netfilter/nf_conntrack_core.h> |
a0891aa6 | 25 | #include <net/netfilter/nf_conntrack_extend.h> |
f6180121 | 26 | |
e34d5c1a | 27 | static DEFINE_MUTEX(nf_ct_ecache_mutex); |
13b18339 | 28 | |
e34d5c1a PNA |
29 | struct nf_ct_event_notifier *nf_conntrack_event_cb __read_mostly; |
30 | EXPORT_SYMBOL_GPL(nf_conntrack_event_cb); | |
31 | ||
32 | struct nf_exp_event_notifier *nf_expect_event_cb __read_mostly; | |
33 | EXPORT_SYMBOL_GPL(nf_expect_event_cb); | |
f6180121 | 34 | |
f6180121 MJ |
35 | /* deliver cached events and clear cache entry - must be called with locally |
36 | * disabled softirqs */ | |
a0891aa6 | 37 | void nf_ct_deliver_cached_events(struct nf_conn *ct) |
f6180121 | 38 | { |
a0891aa6 | 39 | unsigned long events; |
e34d5c1a | 40 | struct nf_ct_event_notifier *notify; |
a0891aa6 | 41 | struct nf_conntrack_ecache *e; |
e34d5c1a PNA |
42 | |
43 | rcu_read_lock(); | |
44 | notify = rcu_dereference(nf_conntrack_event_cb); | |
45 | if (notify == NULL) | |
46 | goto out_unlock; | |
47 | ||
a0891aa6 PNA |
48 | e = nf_ct_ecache_find(ct); |
49 | if (e == NULL) | |
50 | goto out_unlock; | |
51 | ||
52 | events = xchg(&e->cache, 0); | |
53 | ||
54 | if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct) && events) { | |
19abb7b0 | 55 | struct nf_ct_event item = { |
a0891aa6 | 56 | .ct = ct, |
19abb7b0 PNA |
57 | .pid = 0, |
58 | .report = 0 | |
59 | }; | |
dd7669a9 PNA |
60 | int ret; |
61 | /* We make a copy of the missed event cache without taking | |
62 | * the lock, thus we may send missed events twice. However, | |
63 | * this does not harm and it happens very rarely. */ | |
64 | unsigned long missed = e->missed; | |
65 | ||
66 | ret = notify->fcn(events | missed, &item); | |
67 | if (unlikely(ret < 0 || missed)) { | |
68 | spin_lock_bh(&ct->lock); | |
69 | if (ret < 0) | |
70 | e->missed |= events; | |
71 | else | |
72 | e->missed &= ~missed; | |
73 | spin_unlock_bh(&ct->lock); | |
74 | } | |
19abb7b0 | 75 | } |
f6180121 | 76 | |
e34d5c1a PNA |
77 | out_unlock: |
78 | rcu_read_unlock(); | |
f6180121 | 79 | } |
13b18339 | 80 | EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); |
f6180121 | 81 | |
e34d5c1a | 82 | int nf_conntrack_register_notifier(struct nf_ct_event_notifier *new) |
010c7d6f | 83 | { |
e34d5c1a | 84 | int ret = 0; |
b56f2d55 | 85 | struct nf_ct_event_notifier *notify; |
e34d5c1a PNA |
86 | |
87 | mutex_lock(&nf_ct_ecache_mutex); | |
b56f2d55 PM |
88 | notify = rcu_dereference_protected(nf_conntrack_event_cb, |
89 | lockdep_is_held(&nf_ct_ecache_mutex)); | |
90 | if (notify != NULL) { | |
e34d5c1a PNA |
91 | ret = -EBUSY; |
92 | goto out_unlock; | |
93 | } | |
94 | rcu_assign_pointer(nf_conntrack_event_cb, new); | |
95 | mutex_unlock(&nf_ct_ecache_mutex); | |
96 | return ret; | |
97 | ||
98 | out_unlock: | |
99 | mutex_unlock(&nf_ct_ecache_mutex); | |
100 | return ret; | |
010c7d6f PM |
101 | } |
102 | EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier); | |
103 | ||
e34d5c1a | 104 | void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *new) |
010c7d6f | 105 | { |
b56f2d55 PM |
106 | struct nf_ct_event_notifier *notify; |
107 | ||
e34d5c1a | 108 | mutex_lock(&nf_ct_ecache_mutex); |
b56f2d55 PM |
109 | notify = rcu_dereference_protected(nf_conntrack_event_cb, |
110 | lockdep_is_held(&nf_ct_ecache_mutex)); | |
111 | BUG_ON(notify != new); | |
e34d5c1a PNA |
112 | rcu_assign_pointer(nf_conntrack_event_cb, NULL); |
113 | mutex_unlock(&nf_ct_ecache_mutex); | |
010c7d6f PM |
114 | } |
115 | EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier); | |
116 | ||
e34d5c1a | 117 | int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *new) |
010c7d6f | 118 | { |
e34d5c1a | 119 | int ret = 0; |
b56f2d55 | 120 | struct nf_exp_event_notifier *notify; |
e34d5c1a PNA |
121 | |
122 | mutex_lock(&nf_ct_ecache_mutex); | |
b56f2d55 PM |
123 | notify = rcu_dereference_protected(nf_expect_event_cb, |
124 | lockdep_is_held(&nf_ct_ecache_mutex)); | |
125 | if (notify != NULL) { | |
e34d5c1a PNA |
126 | ret = -EBUSY; |
127 | goto out_unlock; | |
128 | } | |
129 | rcu_assign_pointer(nf_expect_event_cb, new); | |
130 | mutex_unlock(&nf_ct_ecache_mutex); | |
131 | return ret; | |
132 | ||
133 | out_unlock: | |
134 | mutex_unlock(&nf_ct_ecache_mutex); | |
135 | return ret; | |
010c7d6f | 136 | } |
6823645d | 137 | EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier); |
010c7d6f | 138 | |
e34d5c1a | 139 | void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *new) |
010c7d6f | 140 | { |
b56f2d55 PM |
141 | struct nf_exp_event_notifier *notify; |
142 | ||
e34d5c1a | 143 | mutex_lock(&nf_ct_ecache_mutex); |
b56f2d55 PM |
144 | notify = rcu_dereference_protected(nf_expect_event_cb, |
145 | lockdep_is_held(&nf_ct_ecache_mutex)); | |
146 | BUG_ON(notify != new); | |
e34d5c1a PNA |
147 | rcu_assign_pointer(nf_expect_event_cb, NULL); |
148 | mutex_unlock(&nf_ct_ecache_mutex); | |
010c7d6f | 149 | } |
6823645d | 150 | EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier); |
a0891aa6 PNA |
151 | |
152 | #define NF_CT_EVENTS_DEFAULT 1 | |
153 | static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT; | |
dd7669a9 | 154 | static int nf_ct_events_retry_timeout __read_mostly = 15*HZ; |
a0891aa6 PNA |
155 | |
156 | #ifdef CONFIG_SYSCTL | |
157 | static struct ctl_table event_sysctl_table[] = { | |
158 | { | |
a0891aa6 PNA |
159 | .procname = "nf_conntrack_events", |
160 | .data = &init_net.ct.sysctl_events, | |
161 | .maxlen = sizeof(unsigned int), | |
162 | .mode = 0644, | |
163 | .proc_handler = proc_dointvec, | |
164 | }, | |
dd7669a9 | 165 | { |
dd7669a9 PNA |
166 | .procname = "nf_conntrack_events_retry_timeout", |
167 | .data = &init_net.ct.sysctl_events_retry_timeout, | |
168 | .maxlen = sizeof(unsigned int), | |
169 | .mode = 0644, | |
170 | .proc_handler = proc_dointvec_jiffies, | |
171 | }, | |
a0891aa6 PNA |
172 | {} |
173 | }; | |
174 | #endif /* CONFIG_SYSCTL */ | |
175 | ||
176 | static struct nf_ct_ext_type event_extend __read_mostly = { | |
177 | .len = sizeof(struct nf_conntrack_ecache), | |
178 | .align = __alignof__(struct nf_conntrack_ecache), | |
179 | .id = NF_CT_EXT_ECACHE, | |
180 | }; | |
181 | ||
182 | #ifdef CONFIG_SYSCTL | |
183 | static int nf_conntrack_event_init_sysctl(struct net *net) | |
184 | { | |
185 | struct ctl_table *table; | |
186 | ||
187 | table = kmemdup(event_sysctl_table, sizeof(event_sysctl_table), | |
188 | GFP_KERNEL); | |
189 | if (!table) | |
190 | goto out; | |
191 | ||
192 | table[0].data = &net->ct.sysctl_events; | |
dd7669a9 | 193 | table[1].data = &net->ct.sysctl_events_retry_timeout; |
a0891aa6 PNA |
194 | |
195 | net->ct.event_sysctl_header = | |
196 | register_net_sysctl_table(net, | |
197 | nf_net_netfilter_sysctl_path, table); | |
198 | if (!net->ct.event_sysctl_header) { | |
199 | printk(KERN_ERR "nf_ct_event: can't register to sysctl.\n"); | |
200 | goto out_register; | |
201 | } | |
202 | return 0; | |
203 | ||
204 | out_register: | |
205 | kfree(table); | |
206 | out: | |
207 | return -ENOMEM; | |
208 | } | |
209 | ||
210 | static void nf_conntrack_event_fini_sysctl(struct net *net) | |
211 | { | |
212 | struct ctl_table *table; | |
213 | ||
214 | table = net->ct.event_sysctl_header->ctl_table_arg; | |
215 | unregister_net_sysctl_table(net->ct.event_sysctl_header); | |
216 | kfree(table); | |
217 | } | |
218 | #else | |
219 | static int nf_conntrack_event_init_sysctl(struct net *net) | |
220 | { | |
221 | return 0; | |
222 | } | |
223 | ||
224 | static void nf_conntrack_event_fini_sysctl(struct net *net) | |
225 | { | |
226 | } | |
227 | #endif /* CONFIG_SYSCTL */ | |
228 | ||
229 | int nf_conntrack_ecache_init(struct net *net) | |
230 | { | |
231 | int ret; | |
232 | ||
233 | net->ct.sysctl_events = nf_ct_events; | |
dd7669a9 | 234 | net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout; |
a0891aa6 PNA |
235 | |
236 | if (net_eq(net, &init_net)) { | |
237 | ret = nf_ct_extend_register(&event_extend); | |
238 | if (ret < 0) { | |
239 | printk(KERN_ERR "nf_ct_event: Unable to register " | |
240 | "event extension.\n"); | |
241 | goto out_extend_register; | |
242 | } | |
243 | } | |
244 | ||
245 | ret = nf_conntrack_event_init_sysctl(net); | |
246 | if (ret < 0) | |
247 | goto out_sysctl; | |
248 | ||
249 | return 0; | |
250 | ||
251 | out_sysctl: | |
252 | if (net_eq(net, &init_net)) | |
253 | nf_ct_extend_unregister(&event_extend); | |
254 | out_extend_register: | |
255 | return ret; | |
256 | } | |
257 | ||
258 | void nf_conntrack_ecache_fini(struct net *net) | |
259 | { | |
260 | nf_conntrack_event_fini_sysctl(net); | |
261 | if (net_eq(net, &init_net)) | |
262 | nf_ct_extend_unregister(&event_extend); | |
263 | } |