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