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Commit | Line | Data |
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8f03dea5 MJ |
1 | /* L3/L4 protocol support for nf_conntrack. */ |
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/module.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
d62f9ed4 | 16 | #include <linux/mutex.h> |
8f03dea5 MJ |
17 | #include <linux/vmalloc.h> |
18 | #include <linux/stddef.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/percpu.h> | |
8f03dea5 MJ |
21 | #include <linux/notifier.h> |
22 | #include <linux/kernel.h> | |
23 | #include <linux/netdevice.h> | |
efb9a8c2 | 24 | #include <linux/rtnetlink.h> |
8f03dea5 MJ |
25 | |
26 | #include <net/netfilter/nf_conntrack.h> | |
27 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
605dcad6 | 28 | #include <net/netfilter/nf_conntrack_l4proto.h> |
8f03dea5 MJ |
29 | #include <net/netfilter/nf_conntrack_core.h> |
30 | ||
42bad1da | 31 | static struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly; |
ae5718fb | 32 | struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly; |
13b18339 | 33 | EXPORT_SYMBOL_GPL(nf_ct_l3protos); |
8f03dea5 | 34 | |
b19caa0c | 35 | static DEFINE_MUTEX(nf_ct_proto_mutex); |
d62f9ed4 | 36 | |
b19caa0c | 37 | #ifdef CONFIG_SYSCTL |
d62f9ed4 | 38 | static int |
b3fd3ffe | 39 | nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_path *path, |
d62f9ed4 PM |
40 | struct ctl_table *table, unsigned int *users) |
41 | { | |
42 | if (*header == NULL) { | |
b3fd3ffe | 43 | *header = register_sysctl_paths(path, table); |
d62f9ed4 PM |
44 | if (*header == NULL) |
45 | return -ENOMEM; | |
46 | } | |
47 | if (users != NULL) | |
48 | (*users)++; | |
49 | return 0; | |
50 | } | |
51 | ||
52 | static void | |
53 | nf_ct_unregister_sysctl(struct ctl_table_header **header, | |
54 | struct ctl_table *table, unsigned int *users) | |
55 | { | |
56 | if (users != NULL && --*users > 0) | |
57 | return; | |
b3fd3ffe PE |
58 | |
59 | unregister_sysctl_table(*header); | |
d62f9ed4 PM |
60 | *header = NULL; |
61 | } | |
62 | #endif | |
63 | ||
605dcad6 MJ |
64 | struct nf_conntrack_l4proto * |
65 | __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto) | |
8f03dea5 MJ |
66 | { |
67 | if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL)) | |
605dcad6 | 68 | return &nf_conntrack_l4proto_generic; |
8f03dea5 | 69 | |
923f4902 | 70 | return rcu_dereference(nf_ct_protos[l3proto][l4proto]); |
8f03dea5 | 71 | } |
13b18339 | 72 | EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find); |
8f03dea5 MJ |
73 | |
74 | /* this is guaranteed to always return a valid protocol helper, since | |
75 | * it falls back to generic_protocol */ | |
8f03dea5 MJ |
76 | struct nf_conntrack_l3proto * |
77 | nf_ct_l3proto_find_get(u_int16_t l3proto) | |
78 | { | |
79 | struct nf_conntrack_l3proto *p; | |
80 | ||
923f4902 | 81 | rcu_read_lock(); |
8f03dea5 MJ |
82 | p = __nf_ct_l3proto_find(l3proto); |
83 | if (!try_module_get(p->me)) | |
605dcad6 | 84 | p = &nf_conntrack_l3proto_generic; |
923f4902 | 85 | rcu_read_unlock(); |
8f03dea5 MJ |
86 | |
87 | return p; | |
88 | } | |
13b18339 | 89 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get); |
8f03dea5 MJ |
90 | |
91 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
92 | { | |
93 | module_put(p->me); | |
94 | } | |
13b18339 | 95 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_put); |
8f03dea5 MJ |
96 | |
97 | int | |
98 | nf_ct_l3proto_try_module_get(unsigned short l3proto) | |
99 | { | |
100 | int ret; | |
101 | struct nf_conntrack_l3proto *p; | |
102 | ||
103 | retry: p = nf_ct_l3proto_find_get(l3proto); | |
605dcad6 | 104 | if (p == &nf_conntrack_l3proto_generic) { |
8f03dea5 MJ |
105 | ret = request_module("nf_conntrack-%d", l3proto); |
106 | if (!ret) | |
107 | goto retry; | |
108 | ||
109 | return -EPROTOTYPE; | |
110 | } | |
111 | ||
112 | return 0; | |
113 | } | |
13b18339 | 114 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get); |
8f03dea5 MJ |
115 | |
116 | void nf_ct_l3proto_module_put(unsigned short l3proto) | |
117 | { | |
118 | struct nf_conntrack_l3proto *p; | |
119 | ||
3b254c54 PM |
120 | /* rcu_read_lock not necessary since the caller holds a reference, but |
121 | * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find() | |
122 | */ | |
123 | rcu_read_lock(); | |
8f03dea5 | 124 | p = __nf_ct_l3proto_find(l3proto); |
8f03dea5 | 125 | module_put(p->me); |
3b254c54 | 126 | rcu_read_unlock(); |
8f03dea5 | 127 | } |
13b18339 | 128 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put); |
8f03dea5 MJ |
129 | |
130 | static int kill_l3proto(struct nf_conn *i, void *data) | |
131 | { | |
5e8fbe2a | 132 | return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto; |
8f03dea5 MJ |
133 | } |
134 | ||
605dcad6 | 135 | static int kill_l4proto(struct nf_conn *i, void *data) |
8f03dea5 | 136 | { |
605dcad6 MJ |
137 | struct nf_conntrack_l4proto *l4proto; |
138 | l4proto = (struct nf_conntrack_l4proto *)data; | |
5e8fbe2a PM |
139 | return nf_ct_protonum(i) == l4proto->l4proto && |
140 | nf_ct_l3num(i) == l4proto->l3proto; | |
8f03dea5 MJ |
141 | } |
142 | ||
d62f9ed4 PM |
143 | static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto) |
144 | { | |
145 | int err = 0; | |
146 | ||
147 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
148 | if (l3proto->ctl_table != NULL) { |
149 | err = nf_ct_register_sysctl(&l3proto->ctl_table_header, | |
150 | l3proto->ctl_table_path, | |
151 | l3proto->ctl_table, NULL); | |
152 | } | |
d62f9ed4 PM |
153 | #endif |
154 | return err; | |
155 | } | |
156 | ||
157 | static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) | |
158 | { | |
159 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
160 | if (l3proto->ctl_table_header != NULL) |
161 | nf_ct_unregister_sysctl(&l3proto->ctl_table_header, | |
162 | l3proto->ctl_table, NULL); | |
d62f9ed4 PM |
163 | #endif |
164 | } | |
165 | ||
8f03dea5 MJ |
166 | int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) |
167 | { | |
168 | int ret = 0; | |
169 | ||
0661cca9 PM |
170 | if (proto->l3proto >= AF_MAX) |
171 | return -EBUSY; | |
ae5718fb | 172 | |
d0dba725 HE |
173 | if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size) |
174 | return -EINVAL; | |
175 | ||
b19caa0c | 176 | mutex_lock(&nf_ct_proto_mutex); |
605dcad6 | 177 | if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { |
8f03dea5 | 178 | ret = -EBUSY; |
ae5718fb | 179 | goto out_unlock; |
8f03dea5 | 180 | } |
d62f9ed4 PM |
181 | |
182 | ret = nf_ct_l3proto_register_sysctl(proto); | |
183 | if (ret < 0) | |
0661cca9 PM |
184 | goto out_unlock; |
185 | ||
d0dba725 HE |
186 | if (proto->nlattr_tuple_size) |
187 | proto->nla_size = 3 * proto->nlattr_tuple_size(); | |
188 | ||
0661cca9 | 189 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); |
8f03dea5 | 190 | |
ae5718fb | 191 | out_unlock: |
b19caa0c | 192 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
193 | return ret; |
194 | } | |
13b18339 | 195 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register); |
8f03dea5 | 196 | |
fe3eb20c | 197 | void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto) |
8f03dea5 | 198 | { |
678d6675 AD |
199 | struct net *net; |
200 | ||
fe3eb20c | 201 | BUG_ON(proto->l3proto >= AF_MAX); |
ae5718fb | 202 | |
b19caa0c | 203 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 204 | BUG_ON(nf_ct_l3protos[proto->l3proto] != proto); |
923f4902 PM |
205 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], |
206 | &nf_conntrack_l3proto_generic); | |
0661cca9 | 207 | nf_ct_l3proto_unregister_sysctl(proto); |
b19caa0c | 208 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 209 | |
0661cca9 | 210 | synchronize_rcu(); |
d62f9ed4 | 211 | |
8f03dea5 | 212 | /* Remove all contrack entries for this protocol */ |
efb9a8c2 | 213 | rtnl_lock(); |
678d6675 AD |
214 | for_each_net(net) |
215 | nf_ct_iterate_cleanup(net, kill_l3proto, proto); | |
efb9a8c2 | 216 | rtnl_unlock(); |
8f03dea5 | 217 | } |
13b18339 | 218 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister); |
8f03dea5 | 219 | |
d62f9ed4 PM |
220 | static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto) |
221 | { | |
222 | int err = 0; | |
223 | ||
224 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
225 | if (l4proto->ctl_table != NULL) { |
226 | err = nf_ct_register_sysctl(l4proto->ctl_table_header, | |
227 | nf_net_netfilter_sysctl_path, | |
228 | l4proto->ctl_table, | |
229 | l4proto->ctl_table_users); | |
a999e683 PM |
230 | if (err < 0) |
231 | goto out; | |
d62f9ed4 | 232 | } |
a999e683 PM |
233 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
234 | if (l4proto->ctl_compat_table != NULL) { | |
235 | err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header, | |
236 | nf_net_ipv4_netfilter_sysctl_path, | |
237 | l4proto->ctl_compat_table, NULL); | |
238 | if (err == 0) | |
239 | goto out; | |
240 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
241 | l4proto->ctl_table, | |
242 | l4proto->ctl_table_users); | |
243 | } | |
244 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
245 | out: | |
933a41e7 | 246 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
247 | return err; |
248 | } | |
249 | ||
250 | static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) | |
251 | { | |
252 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
253 | if (l4proto->ctl_table_header != NULL && |
254 | *l4proto->ctl_table_header != NULL) | |
255 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
256 | l4proto->ctl_table, | |
257 | l4proto->ctl_table_users); | |
a999e683 PM |
258 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
259 | if (l4proto->ctl_compat_table_header != NULL) | |
260 | nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, | |
261 | l4proto->ctl_compat_table, NULL); | |
262 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 | 263 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
264 | } |
265 | ||
8f03dea5 MJ |
266 | /* FIXME: Allow NULL functions and sub in pointers to generic for |
267 | them. --RR */ | |
605dcad6 | 268 | int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 MJ |
269 | { |
270 | int ret = 0; | |
271 | ||
0661cca9 PM |
272 | if (l4proto->l3proto >= PF_MAX) |
273 | return -EBUSY; | |
ae5718fb | 274 | |
d0dba725 HE |
275 | if ((l4proto->to_nlattr && !l4proto->nlattr_size) |
276 | || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size)) | |
277 | return -EINVAL; | |
278 | ||
b19caa0c | 279 | mutex_lock(&nf_ct_proto_mutex); |
c6a1e615 | 280 | if (!nf_ct_protos[l4proto->l3proto]) { |
8f03dea5 | 281 | /* l3proto may be loaded latter. */ |
605dcad6 | 282 | struct nf_conntrack_l4proto **proto_array; |
8f03dea5 MJ |
283 | int i; |
284 | ||
c6a1e615 PM |
285 | proto_array = kmalloc(MAX_NF_CT_PROTO * |
286 | sizeof(struct nf_conntrack_l4proto *), | |
287 | GFP_KERNEL); | |
8f03dea5 MJ |
288 | if (proto_array == NULL) { |
289 | ret = -ENOMEM; | |
b19caa0c | 290 | goto out_unlock; |
8f03dea5 | 291 | } |
c6a1e615 | 292 | |
8f03dea5 | 293 | for (i = 0; i < MAX_NF_CT_PROTO; i++) |
605dcad6 | 294 | proto_array[i] = &nf_conntrack_l4proto_generic; |
c6a1e615 PM |
295 | nf_ct_protos[l4proto->l3proto] = proto_array; |
296 | } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != | |
297 | &nf_conntrack_l4proto_generic) { | |
298 | ret = -EBUSY; | |
299 | goto out_unlock; | |
8f03dea5 MJ |
300 | } |
301 | ||
d62f9ed4 PM |
302 | ret = nf_ct_l4proto_register_sysctl(l4proto); |
303 | if (ret < 0) | |
0661cca9 PM |
304 | goto out_unlock; |
305 | ||
d0dba725 HE |
306 | l4proto->nla_size = 0; |
307 | if (l4proto->nlattr_size) | |
308 | l4proto->nla_size += l4proto->nlattr_size(); | |
309 | if (l4proto->nlattr_tuple_size) | |
310 | l4proto->nla_size += 3 * l4proto->nlattr_tuple_size(); | |
311 | ||
c6a1e615 PM |
312 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
313 | l4proto); | |
8f03dea5 MJ |
314 | |
315 | out_unlock: | |
b19caa0c | 316 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
317 | return ret; |
318 | } | |
13b18339 | 319 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register); |
8f03dea5 | 320 | |
fe3eb20c | 321 | void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 | 322 | { |
678d6675 AD |
323 | struct net *net; |
324 | ||
fe3eb20c | 325 | BUG_ON(l4proto->l3proto >= PF_MAX); |
ae5718fb | 326 | |
b19caa0c | 327 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 328 | BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto); |
923f4902 PM |
329 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
330 | &nf_conntrack_l4proto_generic); | |
0661cca9 | 331 | nf_ct_l4proto_unregister_sysctl(l4proto); |
b19caa0c | 332 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 333 | |
0661cca9 | 334 | synchronize_rcu(); |
d62f9ed4 | 335 | |
8f03dea5 | 336 | /* Remove all contrack entries for this protocol */ |
efb9a8c2 | 337 | rtnl_lock(); |
678d6675 AD |
338 | for_each_net(net) |
339 | nf_ct_iterate_cleanup(net, kill_l4proto, l4proto); | |
efb9a8c2 | 340 | rtnl_unlock(); |
8f03dea5 | 341 | } |
13b18339 | 342 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister); |
ac5357eb PM |
343 | |
344 | int nf_conntrack_proto_init(void) | |
345 | { | |
346 | unsigned int i; | |
347 | int err; | |
348 | ||
349 | err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic); | |
350 | if (err < 0) | |
351 | return err; | |
352 | ||
353 | for (i = 0; i < AF_MAX; i++) | |
354 | rcu_assign_pointer(nf_ct_l3protos[i], | |
355 | &nf_conntrack_l3proto_generic); | |
356 | return 0; | |
357 | } | |
358 | ||
359 | void nf_conntrack_proto_fini(void) | |
360 | { | |
361 | unsigned int i; | |
362 | ||
363 | nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic); | |
364 | ||
365 | /* free l3proto protocol tables */ | |
366 | for (i = 0; i < PF_MAX; i++) | |
367 | kfree(nf_ct_protos[i]); | |
368 | } |