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> | |
d62f9ed4 | 15 | #include <linux/mutex.h> |
8f03dea5 MJ |
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> | |
21 | #include <linux/moduleparam.h> | |
22 | #include <linux/notifier.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/netdevice.h> | |
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 | ||
605dcad6 | 31 | 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 PM |
38 | static int |
39 | nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path, | |
40 | struct ctl_table *table, unsigned int *users) | |
41 | { | |
42 | if (*header == NULL) { | |
43 | *header = nf_register_sysctl_table(path, table); | |
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; | |
58 | nf_unregister_sysctl_table(*header, table); | |
59 | *header = NULL; | |
60 | } | |
61 | #endif | |
62 | ||
605dcad6 MJ |
63 | struct nf_conntrack_l4proto * |
64 | __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto) | |
8f03dea5 MJ |
65 | { |
66 | if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL)) | |
605dcad6 | 67 | return &nf_conntrack_l4proto_generic; |
8f03dea5 | 68 | |
923f4902 | 69 | return rcu_dereference(nf_ct_protos[l3proto][l4proto]); |
8f03dea5 | 70 | } |
13b18339 | 71 | EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find); |
8f03dea5 MJ |
72 | |
73 | /* this is guaranteed to always return a valid protocol helper, since | |
74 | * it falls back to generic_protocol */ | |
605dcad6 MJ |
75 | struct nf_conntrack_l4proto * |
76 | nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto) | |
8f03dea5 | 77 | { |
605dcad6 | 78 | struct nf_conntrack_l4proto *p; |
8f03dea5 | 79 | |
923f4902 | 80 | rcu_read_lock(); |
605dcad6 | 81 | p = __nf_ct_l4proto_find(l3proto, l4proto); |
8f03dea5 | 82 | if (!try_module_get(p->me)) |
605dcad6 | 83 | p = &nf_conntrack_l4proto_generic; |
923f4902 | 84 | rcu_read_unlock(); |
8f03dea5 MJ |
85 | |
86 | return p; | |
87 | } | |
13b18339 | 88 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get); |
8f03dea5 | 89 | |
605dcad6 | 90 | void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p) |
8f03dea5 MJ |
91 | { |
92 | module_put(p->me); | |
93 | } | |
13b18339 | 94 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_put); |
8f03dea5 MJ |
95 | |
96 | struct nf_conntrack_l3proto * | |
97 | nf_ct_l3proto_find_get(u_int16_t l3proto) | |
98 | { | |
99 | struct nf_conntrack_l3proto *p; | |
100 | ||
923f4902 | 101 | rcu_read_lock(); |
8f03dea5 MJ |
102 | p = __nf_ct_l3proto_find(l3proto); |
103 | if (!try_module_get(p->me)) | |
605dcad6 | 104 | p = &nf_conntrack_l3proto_generic; |
923f4902 | 105 | rcu_read_unlock(); |
8f03dea5 MJ |
106 | |
107 | return p; | |
108 | } | |
13b18339 | 109 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get); |
8f03dea5 MJ |
110 | |
111 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
112 | { | |
113 | module_put(p->me); | |
114 | } | |
13b18339 | 115 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_put); |
8f03dea5 MJ |
116 | |
117 | int | |
118 | nf_ct_l3proto_try_module_get(unsigned short l3proto) | |
119 | { | |
120 | int ret; | |
121 | struct nf_conntrack_l3proto *p; | |
122 | ||
123 | retry: p = nf_ct_l3proto_find_get(l3proto); | |
605dcad6 | 124 | if (p == &nf_conntrack_l3proto_generic) { |
8f03dea5 MJ |
125 | ret = request_module("nf_conntrack-%d", l3proto); |
126 | if (!ret) | |
127 | goto retry; | |
128 | ||
129 | return -EPROTOTYPE; | |
130 | } | |
131 | ||
132 | return 0; | |
133 | } | |
13b18339 | 134 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get); |
8f03dea5 MJ |
135 | |
136 | void nf_ct_l3proto_module_put(unsigned short l3proto) | |
137 | { | |
138 | struct nf_conntrack_l3proto *p; | |
139 | ||
923f4902 | 140 | /* rcu_read_lock not necessary since the caller holds a reference */ |
8f03dea5 | 141 | p = __nf_ct_l3proto_find(l3proto); |
8f03dea5 MJ |
142 | module_put(p->me); |
143 | } | |
13b18339 | 144 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put); |
8f03dea5 MJ |
145 | |
146 | static int kill_l3proto(struct nf_conn *i, void *data) | |
147 | { | |
148 | return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == | |
149 | ((struct nf_conntrack_l3proto *)data)->l3proto); | |
150 | } | |
151 | ||
605dcad6 | 152 | static int kill_l4proto(struct nf_conn *i, void *data) |
8f03dea5 | 153 | { |
605dcad6 MJ |
154 | struct nf_conntrack_l4proto *l4proto; |
155 | l4proto = (struct nf_conntrack_l4proto *)data; | |
8f03dea5 | 156 | return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum == |
605dcad6 | 157 | l4proto->l4proto) && |
8f03dea5 | 158 | (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == |
605dcad6 | 159 | l4proto->l3proto); |
8f03dea5 MJ |
160 | } |
161 | ||
d62f9ed4 PM |
162 | static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto) |
163 | { | |
164 | int err = 0; | |
165 | ||
166 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
167 | if (l3proto->ctl_table != NULL) { |
168 | err = nf_ct_register_sysctl(&l3proto->ctl_table_header, | |
169 | l3proto->ctl_table_path, | |
170 | l3proto->ctl_table, NULL); | |
171 | } | |
d62f9ed4 PM |
172 | #endif |
173 | return err; | |
174 | } | |
175 | ||
176 | static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) | |
177 | { | |
178 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
179 | if (l3proto->ctl_table_header != NULL) |
180 | nf_ct_unregister_sysctl(&l3proto->ctl_table_header, | |
181 | l3proto->ctl_table, NULL); | |
d62f9ed4 PM |
182 | #endif |
183 | } | |
184 | ||
8f03dea5 MJ |
185 | int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) |
186 | { | |
187 | int ret = 0; | |
188 | ||
0661cca9 PM |
189 | if (proto->l3proto >= AF_MAX) |
190 | return -EBUSY; | |
ae5718fb | 191 | |
b19caa0c | 192 | mutex_lock(&nf_ct_proto_mutex); |
605dcad6 | 193 | if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { |
8f03dea5 | 194 | ret = -EBUSY; |
ae5718fb | 195 | goto out_unlock; |
8f03dea5 | 196 | } |
d62f9ed4 PM |
197 | |
198 | ret = nf_ct_l3proto_register_sysctl(proto); | |
199 | if (ret < 0) | |
0661cca9 PM |
200 | goto out_unlock; |
201 | ||
202 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); | |
8f03dea5 | 203 | |
ae5718fb | 204 | out_unlock: |
b19caa0c | 205 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
206 | return ret; |
207 | } | |
13b18339 | 208 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register); |
8f03dea5 | 209 | |
fe3eb20c | 210 | void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto) |
8f03dea5 | 211 | { |
fe3eb20c | 212 | BUG_ON(proto->l3proto >= AF_MAX); |
ae5718fb | 213 | |
b19caa0c | 214 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 215 | BUG_ON(nf_ct_l3protos[proto->l3proto] != proto); |
923f4902 PM |
216 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], |
217 | &nf_conntrack_l3proto_generic); | |
0661cca9 | 218 | nf_ct_l3proto_unregister_sysctl(proto); |
b19caa0c | 219 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 220 | |
0661cca9 | 221 | synchronize_rcu(); |
d62f9ed4 | 222 | |
8f03dea5 MJ |
223 | /* Remove all contrack entries for this protocol */ |
224 | nf_ct_iterate_cleanup(kill_l3proto, proto); | |
225 | } | |
13b18339 | 226 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister); |
8f03dea5 | 227 | |
d62f9ed4 PM |
228 | static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto) |
229 | { | |
230 | int err = 0; | |
231 | ||
232 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
233 | if (l4proto->ctl_table != NULL) { |
234 | err = nf_ct_register_sysctl(l4proto->ctl_table_header, | |
235 | nf_net_netfilter_sysctl_path, | |
236 | l4proto->ctl_table, | |
237 | l4proto->ctl_table_users); | |
a999e683 PM |
238 | if (err < 0) |
239 | goto out; | |
d62f9ed4 | 240 | } |
a999e683 PM |
241 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
242 | if (l4proto->ctl_compat_table != NULL) { | |
243 | err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header, | |
244 | nf_net_ipv4_netfilter_sysctl_path, | |
245 | l4proto->ctl_compat_table, NULL); | |
246 | if (err == 0) | |
247 | goto out; | |
248 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
249 | l4proto->ctl_table, | |
250 | l4proto->ctl_table_users); | |
251 | } | |
252 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
253 | out: | |
933a41e7 | 254 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
255 | return err; |
256 | } | |
257 | ||
258 | static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) | |
259 | { | |
260 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
261 | if (l4proto->ctl_table_header != NULL && |
262 | *l4proto->ctl_table_header != NULL) | |
263 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
264 | l4proto->ctl_table, | |
265 | l4proto->ctl_table_users); | |
a999e683 PM |
266 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
267 | if (l4proto->ctl_compat_table_header != NULL) | |
268 | nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, | |
269 | l4proto->ctl_compat_table, NULL); | |
270 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 | 271 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
272 | } |
273 | ||
8f03dea5 MJ |
274 | /* FIXME: Allow NULL functions and sub in pointers to generic for |
275 | them. --RR */ | |
605dcad6 | 276 | int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 MJ |
277 | { |
278 | int ret = 0; | |
279 | ||
0661cca9 PM |
280 | if (l4proto->l3proto >= PF_MAX) |
281 | return -EBUSY; | |
ae5718fb | 282 | |
b19caa0c | 283 | mutex_lock(&nf_ct_proto_mutex); |
8f03dea5 | 284 | retry: |
605dcad6 MJ |
285 | if (nf_ct_protos[l4proto->l3proto]) { |
286 | if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] | |
287 | != &nf_conntrack_l4proto_generic) { | |
8f03dea5 MJ |
288 | ret = -EBUSY; |
289 | goto out_unlock; | |
290 | } | |
291 | } else { | |
292 | /* l3proto may be loaded latter. */ | |
605dcad6 | 293 | struct nf_conntrack_l4proto **proto_array; |
8f03dea5 MJ |
294 | int i; |
295 | ||
605dcad6 | 296 | proto_array = (struct nf_conntrack_l4proto **) |
8f03dea5 | 297 | kmalloc(MAX_NF_CT_PROTO * |
605dcad6 | 298 | sizeof(struct nf_conntrack_l4proto *), |
8f03dea5 MJ |
299 | GFP_KERNEL); |
300 | if (proto_array == NULL) { | |
301 | ret = -ENOMEM; | |
b19caa0c | 302 | goto out_unlock; |
8f03dea5 MJ |
303 | } |
304 | for (i = 0; i < MAX_NF_CT_PROTO; i++) | |
605dcad6 | 305 | proto_array[i] = &nf_conntrack_l4proto_generic; |
8f03dea5 | 306 | |
b19caa0c | 307 | if (nf_ct_protos[l4proto->l3proto]) |
8f03dea5 | 308 | /* bad timing, but no problem */ |
8f03dea5 | 309 | kfree(proto_array); |
b19caa0c | 310 | else |
605dcad6 | 311 | nf_ct_protos[l4proto->l3proto] = proto_array; |
8f03dea5 MJ |
312 | |
313 | /* | |
314 | * Just once because array is never freed until unloading | |
315 | * nf_conntrack.ko | |
316 | */ | |
317 | goto retry; | |
318 | } | |
319 | ||
d62f9ed4 PM |
320 | ret = nf_ct_l4proto_register_sysctl(l4proto); |
321 | if (ret < 0) | |
0661cca9 PM |
322 | goto out_unlock; |
323 | ||
324 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto); | |
8f03dea5 MJ |
325 | |
326 | out_unlock: | |
b19caa0c | 327 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
328 | return ret; |
329 | } | |
13b18339 | 330 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register); |
8f03dea5 | 331 | |
fe3eb20c | 332 | void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 | 333 | { |
fe3eb20c | 334 | BUG_ON(l4proto->l3proto >= PF_MAX); |
ae5718fb | 335 | |
b19caa0c | 336 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 337 | BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto); |
923f4902 PM |
338 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
339 | &nf_conntrack_l4proto_generic); | |
0661cca9 | 340 | nf_ct_l4proto_unregister_sysctl(l4proto); |
b19caa0c | 341 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 342 | |
0661cca9 | 343 | synchronize_rcu(); |
d62f9ed4 | 344 | |
8f03dea5 | 345 | /* Remove all contrack entries for this protocol */ |
605dcad6 | 346 | nf_ct_iterate_cleanup(kill_l4proto, l4proto); |
8f03dea5 | 347 | } |
13b18339 | 348 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister); |
ac5357eb PM |
349 | |
350 | int nf_conntrack_proto_init(void) | |
351 | { | |
352 | unsigned int i; | |
353 | int err; | |
354 | ||
355 | err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic); | |
356 | if (err < 0) | |
357 | return err; | |
358 | ||
359 | for (i = 0; i < AF_MAX; i++) | |
360 | rcu_assign_pointer(nf_ct_l3protos[i], | |
361 | &nf_conntrack_l3proto_generic); | |
362 | return 0; | |
363 | } | |
364 | ||
365 | void nf_conntrack_proto_fini(void) | |
366 | { | |
367 | unsigned int i; | |
368 | ||
369 | nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic); | |
370 | ||
371 | /* free l3proto protocol tables */ | |
372 | for (i = 0; i < PF_MAX; i++) | |
373 | kfree(nf_ct_protos[i]); | |
374 | } |