Commit | Line | Data |
---|---|---|
f6180121 MJ |
1 | /* Event cache for netfilter. */ |
2 | ||
f229f6ce PM |
3 | /* |
4 | * (C) 2005 Harald Welte <laforge@gnumonks.org> | |
5 | * (C) 2005 Patrick McHardy <kaber@trash.net> | |
6 | * (C) 2005-2006 Netfilter Core Team <coreteam@netfilter.org> | |
7 | * (C) 2005 USAGI/WIDE Project <http://www.linux-ipv6.org> | |
f6180121 MJ |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/types.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/stddef.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/percpu.h> | |
f6180121 MJ |
21 | #include <linux/kernel.h> |
22 | #include <linux/netdevice.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
bc3b2d7f | 24 | #include <linux/export.h> |
f6180121 MJ |
25 | |
26 | #include <net/netfilter/nf_conntrack.h> | |
f6180121 | 27 | #include <net/netfilter/nf_conntrack_core.h> |
a0891aa6 | 28 | #include <net/netfilter/nf_conntrack_extend.h> |
f6180121 | 29 | |
e34d5c1a | 30 | static DEFINE_MUTEX(nf_ct_ecache_mutex); |
13b18339 | 31 | |
f6180121 MJ |
32 | /* deliver cached events and clear cache entry - must be called with locally |
33 | * disabled softirqs */ | |
a0891aa6 | 34 | void nf_ct_deliver_cached_events(struct nf_conn *ct) |
f6180121 | 35 | { |
70e9942f | 36 | struct net *net = nf_ct_net(ct); |
58020f77 | 37 | unsigned long events, missed; |
e34d5c1a | 38 | struct nf_ct_event_notifier *notify; |
a0891aa6 | 39 | struct nf_conntrack_ecache *e; |
58020f77 TZ |
40 | struct nf_ct_event item; |
41 | int ret; | |
e34d5c1a PNA |
42 | |
43 | rcu_read_lock(); | |
70e9942f | 44 | notify = rcu_dereference(net->ct.nf_conntrack_event_cb); |
e34d5c1a PNA |
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 | ||
58020f77 TZ |
54 | if (!nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct) || !events) |
55 | goto out_unlock; | |
56 | ||
57 | /* We make a copy of the missed event cache without taking | |
58 | * the lock, thus we may send missed events twice. However, | |
59 | * this does not harm and it happens very rarely. */ | |
60 | missed = e->missed; | |
61 | ||
62 | if (!((events | missed) & e->ctmask)) | |
63 | goto out_unlock; | |
64 | ||
65 | item.ct = ct; | |
15e47304 | 66 | item.portid = 0; |
58020f77 TZ |
67 | item.report = 0; |
68 | ||
69 | ret = notify->fcn(events | missed, &item); | |
70 | ||
71 | if (likely(ret >= 0 && !missed)) | |
72 | goto out_unlock; | |
73 | ||
74 | spin_lock_bh(&ct->lock); | |
75 | if (ret < 0) | |
76 | e->missed |= events; | |
77 | else | |
78 | e->missed &= ~missed; | |
79 | spin_unlock_bh(&ct->lock); | |
f6180121 | 80 | |
e34d5c1a PNA |
81 | out_unlock: |
82 | rcu_read_unlock(); | |
f6180121 | 83 | } |
13b18339 | 84 | EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); |
f6180121 | 85 | |
70e9942f PNA |
86 | int nf_conntrack_register_notifier(struct net *net, |
87 | struct nf_ct_event_notifier *new) | |
010c7d6f | 88 | { |
031d7709 | 89 | int ret; |
b56f2d55 | 90 | struct nf_ct_event_notifier *notify; |
e34d5c1a PNA |
91 | |
92 | mutex_lock(&nf_ct_ecache_mutex); | |
70e9942f | 93 | notify = rcu_dereference_protected(net->ct.nf_conntrack_event_cb, |
b56f2d55 PM |
94 | lockdep_is_held(&nf_ct_ecache_mutex)); |
95 | if (notify != NULL) { | |
e34d5c1a PNA |
96 | ret = -EBUSY; |
97 | goto out_unlock; | |
98 | } | |
cf778b00 | 99 | rcu_assign_pointer(net->ct.nf_conntrack_event_cb, new); |
031d7709 | 100 | ret = 0; |
e34d5c1a PNA |
101 | |
102 | out_unlock: | |
103 | mutex_unlock(&nf_ct_ecache_mutex); | |
104 | return ret; | |
010c7d6f PM |
105 | } |
106 | EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier); | |
107 | ||
70e9942f PNA |
108 | void nf_conntrack_unregister_notifier(struct net *net, |
109 | struct nf_ct_event_notifier *new) | |
010c7d6f | 110 | { |
b56f2d55 PM |
111 | struct nf_ct_event_notifier *notify; |
112 | ||
e34d5c1a | 113 | mutex_lock(&nf_ct_ecache_mutex); |
70e9942f | 114 | notify = rcu_dereference_protected(net->ct.nf_conntrack_event_cb, |
b56f2d55 PM |
115 | lockdep_is_held(&nf_ct_ecache_mutex)); |
116 | BUG_ON(notify != new); | |
70e9942f | 117 | RCU_INIT_POINTER(net->ct.nf_conntrack_event_cb, NULL); |
e34d5c1a | 118 | mutex_unlock(&nf_ct_ecache_mutex); |
09ab11eb | 119 | /* synchronize_rcu() is called from ctnetlink_exit. */ |
010c7d6f PM |
120 | } |
121 | EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier); | |
122 | ||
70e9942f PNA |
123 | int nf_ct_expect_register_notifier(struct net *net, |
124 | struct nf_exp_event_notifier *new) | |
010c7d6f | 125 | { |
031d7709 | 126 | int ret; |
b56f2d55 | 127 | struct nf_exp_event_notifier *notify; |
e34d5c1a PNA |
128 | |
129 | mutex_lock(&nf_ct_ecache_mutex); | |
70e9942f | 130 | notify = rcu_dereference_protected(net->ct.nf_expect_event_cb, |
b56f2d55 PM |
131 | lockdep_is_held(&nf_ct_ecache_mutex)); |
132 | if (notify != NULL) { | |
e34d5c1a PNA |
133 | ret = -EBUSY; |
134 | goto out_unlock; | |
135 | } | |
cf778b00 | 136 | rcu_assign_pointer(net->ct.nf_expect_event_cb, new); |
031d7709 | 137 | ret = 0; |
e34d5c1a PNA |
138 | |
139 | out_unlock: | |
140 | mutex_unlock(&nf_ct_ecache_mutex); | |
141 | return ret; | |
010c7d6f | 142 | } |
6823645d | 143 | EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier); |
010c7d6f | 144 | |
70e9942f PNA |
145 | void nf_ct_expect_unregister_notifier(struct net *net, |
146 | struct nf_exp_event_notifier *new) | |
010c7d6f | 147 | { |
b56f2d55 PM |
148 | struct nf_exp_event_notifier *notify; |
149 | ||
e34d5c1a | 150 | mutex_lock(&nf_ct_ecache_mutex); |
70e9942f | 151 | notify = rcu_dereference_protected(net->ct.nf_expect_event_cb, |
b56f2d55 PM |
152 | lockdep_is_held(&nf_ct_ecache_mutex)); |
153 | BUG_ON(notify != new); | |
70e9942f | 154 | RCU_INIT_POINTER(net->ct.nf_expect_event_cb, NULL); |
e34d5c1a | 155 | mutex_unlock(&nf_ct_ecache_mutex); |
09ab11eb | 156 | /* synchronize_rcu() is called from ctnetlink_exit. */ |
010c7d6f | 157 | } |
6823645d | 158 | EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier); |
a0891aa6 PNA |
159 | |
160 | #define NF_CT_EVENTS_DEFAULT 1 | |
161 | static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT; | |
dd7669a9 | 162 | static int nf_ct_events_retry_timeout __read_mostly = 15*HZ; |
a0891aa6 PNA |
163 | |
164 | #ifdef CONFIG_SYSCTL | |
165 | static struct ctl_table event_sysctl_table[] = { | |
166 | { | |
a0891aa6 PNA |
167 | .procname = "nf_conntrack_events", |
168 | .data = &init_net.ct.sysctl_events, | |
169 | .maxlen = sizeof(unsigned int), | |
170 | .mode = 0644, | |
171 | .proc_handler = proc_dointvec, | |
172 | }, | |
dd7669a9 | 173 | { |
dd7669a9 PNA |
174 | .procname = "nf_conntrack_events_retry_timeout", |
175 | .data = &init_net.ct.sysctl_events_retry_timeout, | |
176 | .maxlen = sizeof(unsigned int), | |
177 | .mode = 0644, | |
178 | .proc_handler = proc_dointvec_jiffies, | |
179 | }, | |
a0891aa6 PNA |
180 | {} |
181 | }; | |
182 | #endif /* CONFIG_SYSCTL */ | |
183 | ||
184 | static struct nf_ct_ext_type event_extend __read_mostly = { | |
185 | .len = sizeof(struct nf_conntrack_ecache), | |
186 | .align = __alignof__(struct nf_conntrack_ecache), | |
187 | .id = NF_CT_EXT_ECACHE, | |
188 | }; | |
189 | ||
190 | #ifdef CONFIG_SYSCTL | |
191 | static int nf_conntrack_event_init_sysctl(struct net *net) | |
192 | { | |
193 | struct ctl_table *table; | |
194 | ||
195 | table = kmemdup(event_sysctl_table, sizeof(event_sysctl_table), | |
196 | GFP_KERNEL); | |
197 | if (!table) | |
198 | goto out; | |
199 | ||
200 | table[0].data = &net->ct.sysctl_events; | |
dd7669a9 | 201 | table[1].data = &net->ct.sysctl_events_retry_timeout; |
a0891aa6 | 202 | |
464dc801 EB |
203 | /* Don't export sysctls to unprivileged users */ |
204 | if (net->user_ns != &init_user_ns) | |
205 | table[0].procname = NULL; | |
206 | ||
a0891aa6 | 207 | net->ct.event_sysctl_header = |
ec8f23ce | 208 | register_net_sysctl(net, "net/netfilter", table); |
a0891aa6 PNA |
209 | if (!net->ct.event_sysctl_header) { |
210 | printk(KERN_ERR "nf_ct_event: can't register to sysctl.\n"); | |
211 | goto out_register; | |
212 | } | |
213 | return 0; | |
214 | ||
215 | out_register: | |
216 | kfree(table); | |
217 | out: | |
218 | return -ENOMEM; | |
219 | } | |
220 | ||
221 | static void nf_conntrack_event_fini_sysctl(struct net *net) | |
222 | { | |
223 | struct ctl_table *table; | |
224 | ||
225 | table = net->ct.event_sysctl_header->ctl_table_arg; | |
226 | unregister_net_sysctl_table(net->ct.event_sysctl_header); | |
227 | kfree(table); | |
228 | } | |
229 | #else | |
230 | static int nf_conntrack_event_init_sysctl(struct net *net) | |
231 | { | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static void nf_conntrack_event_fini_sysctl(struct net *net) | |
236 | { | |
237 | } | |
238 | #endif /* CONFIG_SYSCTL */ | |
239 | ||
3fe0f943 | 240 | int nf_conntrack_ecache_pernet_init(struct net *net) |
a0891aa6 | 241 | { |
a0891aa6 | 242 | net->ct.sysctl_events = nf_ct_events; |
dd7669a9 | 243 | net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout; |
3fe0f943 G |
244 | return nf_conntrack_event_init_sysctl(net); |
245 | } | |
a0891aa6 | 246 | |
3fe0f943 G |
247 | void nf_conntrack_ecache_pernet_fini(struct net *net) |
248 | { | |
249 | nf_conntrack_event_fini_sysctl(net); | |
250 | } | |
a0891aa6 | 251 | |
3fe0f943 G |
252 | int nf_conntrack_ecache_init(void) |
253 | { | |
254 | int ret = nf_ct_extend_register(&event_extend); | |
a0891aa6 | 255 | if (ret < 0) |
3fe0f943 | 256 | pr_err("nf_ct_event: Unable to register event extension.\n"); |
a0891aa6 PNA |
257 | return ret; |
258 | } | |
259 | ||
3fe0f943 | 260 | void nf_conntrack_ecache_fini(void) |
a0891aa6 | 261 | { |
3fe0f943 | 262 | nf_ct_extend_unregister(&event_extend); |
a0891aa6 | 263 | } |