Commit | Line | Data |
---|---|---|
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 | ||
0906a372 AB |
31 | static struct nf_conntrack_l4proto __rcu **nf_ct_protos[PF_MAX] __read_mostly; |
32 | struct nf_conntrack_l3proto __rcu *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 | 129 | |
c1ebd7df PNA |
130 | struct nf_conntrack_l4proto * |
131 | nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num) | |
132 | { | |
133 | struct nf_conntrack_l4proto *p; | |
134 | ||
135 | rcu_read_lock(); | |
136 | p = __nf_ct_l4proto_find(l3num, l4num); | |
137 | if (!try_module_get(p->me)) | |
138 | p = &nf_conntrack_l4proto_generic; | |
139 | rcu_read_unlock(); | |
140 | ||
141 | return p; | |
142 | } | |
143 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get); | |
144 | ||
145 | void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p) | |
146 | { | |
147 | module_put(p->me); | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_put); | |
150 | ||
8f03dea5 MJ |
151 | static int kill_l3proto(struct nf_conn *i, void *data) |
152 | { | |
5e8fbe2a | 153 | return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto; |
8f03dea5 MJ |
154 | } |
155 | ||
605dcad6 | 156 | static int kill_l4proto(struct nf_conn *i, void *data) |
8f03dea5 | 157 | { |
605dcad6 MJ |
158 | struct nf_conntrack_l4proto *l4proto; |
159 | l4proto = (struct nf_conntrack_l4proto *)data; | |
5e8fbe2a PM |
160 | return nf_ct_protonum(i) == l4proto->l4proto && |
161 | nf_ct_l3num(i) == l4proto->l3proto; | |
8f03dea5 MJ |
162 | } |
163 | ||
d62f9ed4 PM |
164 | static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto) |
165 | { | |
166 | int err = 0; | |
167 | ||
168 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
169 | if (l3proto->ctl_table != NULL) { |
170 | err = nf_ct_register_sysctl(&l3proto->ctl_table_header, | |
171 | l3proto->ctl_table_path, | |
172 | l3proto->ctl_table, NULL); | |
173 | } | |
d62f9ed4 PM |
174 | #endif |
175 | return err; | |
176 | } | |
177 | ||
178 | static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) | |
179 | { | |
180 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
181 | if (l3proto->ctl_table_header != NULL) |
182 | nf_ct_unregister_sysctl(&l3proto->ctl_table_header, | |
183 | l3proto->ctl_table, NULL); | |
d62f9ed4 PM |
184 | #endif |
185 | } | |
186 | ||
8f03dea5 MJ |
187 | int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) |
188 | { | |
189 | int ret = 0; | |
0e60ebe0 | 190 | struct nf_conntrack_l3proto *old; |
8f03dea5 | 191 | |
0661cca9 PM |
192 | if (proto->l3proto >= AF_MAX) |
193 | return -EBUSY; | |
ae5718fb | 194 | |
d0dba725 HE |
195 | if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size) |
196 | return -EINVAL; | |
197 | ||
b19caa0c | 198 | mutex_lock(&nf_ct_proto_mutex); |
0e60ebe0 ED |
199 | old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto], |
200 | lockdep_is_held(&nf_ct_proto_mutex)); | |
201 | if (old != &nf_conntrack_l3proto_generic) { | |
8f03dea5 | 202 | ret = -EBUSY; |
ae5718fb | 203 | goto out_unlock; |
8f03dea5 | 204 | } |
d62f9ed4 PM |
205 | |
206 | ret = nf_ct_l3proto_register_sysctl(proto); | |
207 | if (ret < 0) | |
0661cca9 PM |
208 | goto out_unlock; |
209 | ||
d0dba725 HE |
210 | if (proto->nlattr_tuple_size) |
211 | proto->nla_size = 3 * proto->nlattr_tuple_size(); | |
212 | ||
0661cca9 | 213 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); |
8f03dea5 | 214 | |
ae5718fb | 215 | out_unlock: |
b19caa0c | 216 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
217 | return ret; |
218 | } | |
13b18339 | 219 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register); |
8f03dea5 | 220 | |
fe3eb20c | 221 | void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto) |
8f03dea5 | 222 | { |
678d6675 AD |
223 | struct net *net; |
224 | ||
fe3eb20c | 225 | BUG_ON(proto->l3proto >= AF_MAX); |
ae5718fb | 226 | |
b19caa0c | 227 | mutex_lock(&nf_ct_proto_mutex); |
0e60ebe0 ED |
228 | BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto], |
229 | lockdep_is_held(&nf_ct_proto_mutex) | |
230 | ) != proto); | |
923f4902 PM |
231 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], |
232 | &nf_conntrack_l3proto_generic); | |
0661cca9 | 233 | nf_ct_l3proto_unregister_sysctl(proto); |
b19caa0c | 234 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 235 | |
0661cca9 | 236 | synchronize_rcu(); |
d62f9ed4 | 237 | |
8f03dea5 | 238 | /* Remove all contrack entries for this protocol */ |
efb9a8c2 | 239 | rtnl_lock(); |
678d6675 AD |
240 | for_each_net(net) |
241 | nf_ct_iterate_cleanup(net, kill_l3proto, proto); | |
efb9a8c2 | 242 | rtnl_unlock(); |
8f03dea5 | 243 | } |
13b18339 | 244 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister); |
8f03dea5 | 245 | |
d62f9ed4 PM |
246 | static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto) |
247 | { | |
248 | int err = 0; | |
249 | ||
250 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
251 | if (l4proto->ctl_table != NULL) { |
252 | err = nf_ct_register_sysctl(l4proto->ctl_table_header, | |
253 | nf_net_netfilter_sysctl_path, | |
254 | l4proto->ctl_table, | |
255 | l4proto->ctl_table_users); | |
a999e683 PM |
256 | if (err < 0) |
257 | goto out; | |
d62f9ed4 | 258 | } |
a999e683 PM |
259 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
260 | if (l4proto->ctl_compat_table != NULL) { | |
261 | err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header, | |
262 | nf_net_ipv4_netfilter_sysctl_path, | |
263 | l4proto->ctl_compat_table, NULL); | |
264 | if (err == 0) | |
265 | goto out; | |
266 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
267 | l4proto->ctl_table, | |
268 | l4proto->ctl_table_users); | |
269 | } | |
270 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
271 | out: | |
933a41e7 | 272 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
273 | return err; |
274 | } | |
275 | ||
276 | static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) | |
277 | { | |
278 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
279 | if (l4proto->ctl_table_header != NULL && |
280 | *l4proto->ctl_table_header != NULL) | |
281 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
282 | l4proto->ctl_table, | |
283 | l4proto->ctl_table_users); | |
a999e683 PM |
284 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
285 | if (l4proto->ctl_compat_table_header != NULL) | |
286 | nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, | |
287 | l4proto->ctl_compat_table, NULL); | |
288 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 | 289 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
290 | } |
291 | ||
8f03dea5 MJ |
292 | /* FIXME: Allow NULL functions and sub in pointers to generic for |
293 | them. --RR */ | |
605dcad6 | 294 | int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 MJ |
295 | { |
296 | int ret = 0; | |
297 | ||
0661cca9 PM |
298 | if (l4proto->l3proto >= PF_MAX) |
299 | return -EBUSY; | |
ae5718fb | 300 | |
d0dba725 HE |
301 | if ((l4proto->to_nlattr && !l4proto->nlattr_size) |
302 | || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size)) | |
303 | return -EINVAL; | |
304 | ||
b19caa0c | 305 | mutex_lock(&nf_ct_proto_mutex); |
c6a1e615 | 306 | if (!nf_ct_protos[l4proto->l3proto]) { |
8f03dea5 | 307 | /* l3proto may be loaded latter. */ |
c5d277d2 | 308 | struct nf_conntrack_l4proto __rcu **proto_array; |
8f03dea5 MJ |
309 | int i; |
310 | ||
c6a1e615 PM |
311 | proto_array = kmalloc(MAX_NF_CT_PROTO * |
312 | sizeof(struct nf_conntrack_l4proto *), | |
313 | GFP_KERNEL); | |
8f03dea5 MJ |
314 | if (proto_array == NULL) { |
315 | ret = -ENOMEM; | |
b19caa0c | 316 | goto out_unlock; |
8f03dea5 | 317 | } |
c6a1e615 | 318 | |
8f03dea5 | 319 | for (i = 0; i < MAX_NF_CT_PROTO; i++) |
c5d277d2 | 320 | RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic); |
d817d29d ED |
321 | |
322 | /* Before making proto_array visible to lockless readers, | |
323 | * we must make sure its content is committed to memory. | |
324 | */ | |
325 | smp_wmb(); | |
326 | ||
c6a1e615 | 327 | nf_ct_protos[l4proto->l3proto] = proto_array; |
0e60ebe0 ED |
328 | } else if (rcu_dereference_protected( |
329 | nf_ct_protos[l4proto->l3proto][l4proto->l4proto], | |
330 | lockdep_is_held(&nf_ct_proto_mutex) | |
331 | ) != &nf_conntrack_l4proto_generic) { | |
c6a1e615 PM |
332 | ret = -EBUSY; |
333 | goto out_unlock; | |
8f03dea5 MJ |
334 | } |
335 | ||
d62f9ed4 PM |
336 | ret = nf_ct_l4proto_register_sysctl(l4proto); |
337 | if (ret < 0) | |
0661cca9 PM |
338 | goto out_unlock; |
339 | ||
d0dba725 HE |
340 | l4proto->nla_size = 0; |
341 | if (l4proto->nlattr_size) | |
342 | l4proto->nla_size += l4proto->nlattr_size(); | |
343 | if (l4proto->nlattr_tuple_size) | |
344 | l4proto->nla_size += 3 * l4proto->nlattr_tuple_size(); | |
345 | ||
c6a1e615 PM |
346 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
347 | l4proto); | |
8f03dea5 MJ |
348 | |
349 | out_unlock: | |
b19caa0c | 350 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
351 | return ret; |
352 | } | |
13b18339 | 353 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register); |
8f03dea5 | 354 | |
fe3eb20c | 355 | void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 | 356 | { |
678d6675 AD |
357 | struct net *net; |
358 | ||
fe3eb20c | 359 | BUG_ON(l4proto->l3proto >= PF_MAX); |
ae5718fb | 360 | |
b19caa0c | 361 | mutex_lock(&nf_ct_proto_mutex); |
0e60ebe0 ED |
362 | BUG_ON(rcu_dereference_protected( |
363 | nf_ct_protos[l4proto->l3proto][l4proto->l4proto], | |
364 | lockdep_is_held(&nf_ct_proto_mutex) | |
365 | ) != l4proto); | |
923f4902 PM |
366 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
367 | &nf_conntrack_l4proto_generic); | |
0661cca9 | 368 | nf_ct_l4proto_unregister_sysctl(l4proto); |
b19caa0c | 369 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 370 | |
0661cca9 | 371 | synchronize_rcu(); |
d62f9ed4 | 372 | |
8f03dea5 | 373 | /* Remove all contrack entries for this protocol */ |
efb9a8c2 | 374 | rtnl_lock(); |
678d6675 AD |
375 | for_each_net(net) |
376 | nf_ct_iterate_cleanup(net, kill_l4proto, l4proto); | |
efb9a8c2 | 377 | rtnl_unlock(); |
8f03dea5 | 378 | } |
13b18339 | 379 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister); |
ac5357eb PM |
380 | |
381 | int nf_conntrack_proto_init(void) | |
382 | { | |
383 | unsigned int i; | |
384 | int err; | |
385 | ||
386 | err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic); | |
387 | if (err < 0) | |
388 | return err; | |
389 | ||
390 | for (i = 0; i < AF_MAX; i++) | |
391 | rcu_assign_pointer(nf_ct_l3protos[i], | |
392 | &nf_conntrack_l3proto_generic); | |
393 | return 0; | |
394 | } | |
395 | ||
396 | void nf_conntrack_proto_fini(void) | |
397 | { | |
398 | unsigned int i; | |
399 | ||
400 | nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic); | |
401 | ||
402 | /* free l3proto protocol tables */ | |
403 | for (i = 0; i < PF_MAX; i++) | |
404 | kfree(nf_ct_protos[i]); | |
405 | } |