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