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 | ||
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 */ | |
605dcad6 MJ |
76 | struct nf_conntrack_l4proto * |
77 | nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto) | |
8f03dea5 | 78 | { |
605dcad6 | 79 | struct nf_conntrack_l4proto *p; |
8f03dea5 | 80 | |
923f4902 | 81 | rcu_read_lock(); |
605dcad6 | 82 | p = __nf_ct_l4proto_find(l3proto, l4proto); |
8f03dea5 | 83 | if (!try_module_get(p->me)) |
605dcad6 | 84 | p = &nf_conntrack_l4proto_generic; |
923f4902 | 85 | rcu_read_unlock(); |
8f03dea5 MJ |
86 | |
87 | return p; | |
88 | } | |
13b18339 | 89 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get); |
8f03dea5 | 90 | |
605dcad6 | 91 | void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p) |
8f03dea5 MJ |
92 | { |
93 | module_put(p->me); | |
94 | } | |
13b18339 | 95 | EXPORT_SYMBOL_GPL(nf_ct_l4proto_put); |
8f03dea5 MJ |
96 | |
97 | struct nf_conntrack_l3proto * | |
98 | nf_ct_l3proto_find_get(u_int16_t l3proto) | |
99 | { | |
100 | struct nf_conntrack_l3proto *p; | |
101 | ||
923f4902 | 102 | rcu_read_lock(); |
8f03dea5 MJ |
103 | p = __nf_ct_l3proto_find(l3proto); |
104 | if (!try_module_get(p->me)) | |
605dcad6 | 105 | p = &nf_conntrack_l3proto_generic; |
923f4902 | 106 | rcu_read_unlock(); |
8f03dea5 MJ |
107 | |
108 | return p; | |
109 | } | |
13b18339 | 110 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get); |
8f03dea5 MJ |
111 | |
112 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
113 | { | |
114 | module_put(p->me); | |
115 | } | |
13b18339 | 116 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_put); |
8f03dea5 MJ |
117 | |
118 | int | |
119 | nf_ct_l3proto_try_module_get(unsigned short l3proto) | |
120 | { | |
121 | int ret; | |
122 | struct nf_conntrack_l3proto *p; | |
123 | ||
124 | retry: p = nf_ct_l3proto_find_get(l3proto); | |
605dcad6 | 125 | if (p == &nf_conntrack_l3proto_generic) { |
8f03dea5 MJ |
126 | ret = request_module("nf_conntrack-%d", l3proto); |
127 | if (!ret) | |
128 | goto retry; | |
129 | ||
130 | return -EPROTOTYPE; | |
131 | } | |
132 | ||
133 | return 0; | |
134 | } | |
13b18339 | 135 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get); |
8f03dea5 MJ |
136 | |
137 | void nf_ct_l3proto_module_put(unsigned short l3proto) | |
138 | { | |
139 | struct nf_conntrack_l3proto *p; | |
140 | ||
923f4902 | 141 | /* rcu_read_lock not necessary since the caller holds a reference */ |
8f03dea5 | 142 | p = __nf_ct_l3proto_find(l3proto); |
8f03dea5 MJ |
143 | module_put(p->me); |
144 | } | |
13b18339 | 145 | EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put); |
8f03dea5 MJ |
146 | |
147 | static int kill_l3proto(struct nf_conn *i, void *data) | |
148 | { | |
5e8fbe2a | 149 | return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto; |
8f03dea5 MJ |
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; | |
5e8fbe2a PM |
156 | return nf_ct_protonum(i) == l4proto->l4proto && |
157 | nf_ct_l3num(i) == l4proto->l3proto; | |
8f03dea5 MJ |
158 | } |
159 | ||
d62f9ed4 PM |
160 | static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto) |
161 | { | |
162 | int err = 0; | |
163 | ||
164 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
165 | if (l3proto->ctl_table != NULL) { |
166 | err = nf_ct_register_sysctl(&l3proto->ctl_table_header, | |
167 | l3proto->ctl_table_path, | |
168 | l3proto->ctl_table, NULL); | |
169 | } | |
d62f9ed4 PM |
170 | #endif |
171 | return err; | |
172 | } | |
173 | ||
174 | static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) | |
175 | { | |
176 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
177 | if (l3proto->ctl_table_header != NULL) |
178 | nf_ct_unregister_sysctl(&l3proto->ctl_table_header, | |
179 | l3proto->ctl_table, NULL); | |
d62f9ed4 PM |
180 | #endif |
181 | } | |
182 | ||
8f03dea5 MJ |
183 | int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) |
184 | { | |
185 | int ret = 0; | |
186 | ||
0661cca9 PM |
187 | if (proto->l3proto >= AF_MAX) |
188 | return -EBUSY; | |
ae5718fb | 189 | |
b19caa0c | 190 | mutex_lock(&nf_ct_proto_mutex); |
605dcad6 | 191 | if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { |
8f03dea5 | 192 | ret = -EBUSY; |
ae5718fb | 193 | goto out_unlock; |
8f03dea5 | 194 | } |
d62f9ed4 PM |
195 | |
196 | ret = nf_ct_l3proto_register_sysctl(proto); | |
197 | if (ret < 0) | |
0661cca9 PM |
198 | goto out_unlock; |
199 | ||
200 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); | |
8f03dea5 | 201 | |
ae5718fb | 202 | out_unlock: |
b19caa0c | 203 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
204 | return ret; |
205 | } | |
13b18339 | 206 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register); |
8f03dea5 | 207 | |
fe3eb20c | 208 | void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto) |
8f03dea5 | 209 | { |
fe3eb20c | 210 | BUG_ON(proto->l3proto >= AF_MAX); |
ae5718fb | 211 | |
b19caa0c | 212 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 213 | BUG_ON(nf_ct_l3protos[proto->l3proto] != proto); |
923f4902 PM |
214 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], |
215 | &nf_conntrack_l3proto_generic); | |
0661cca9 | 216 | nf_ct_l3proto_unregister_sysctl(proto); |
b19caa0c | 217 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 218 | |
0661cca9 | 219 | synchronize_rcu(); |
d62f9ed4 | 220 | |
8f03dea5 MJ |
221 | /* Remove all contrack entries for this protocol */ |
222 | nf_ct_iterate_cleanup(kill_l3proto, proto); | |
223 | } | |
13b18339 | 224 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister); |
8f03dea5 | 225 | |
d62f9ed4 PM |
226 | static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto) |
227 | { | |
228 | int err = 0; | |
229 | ||
230 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
231 | if (l4proto->ctl_table != NULL) { |
232 | err = nf_ct_register_sysctl(l4proto->ctl_table_header, | |
233 | nf_net_netfilter_sysctl_path, | |
234 | l4proto->ctl_table, | |
235 | l4proto->ctl_table_users); | |
a999e683 PM |
236 | if (err < 0) |
237 | goto out; | |
d62f9ed4 | 238 | } |
a999e683 PM |
239 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
240 | if (l4proto->ctl_compat_table != NULL) { | |
241 | err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header, | |
242 | nf_net_ipv4_netfilter_sysctl_path, | |
243 | l4proto->ctl_compat_table, NULL); | |
244 | if (err == 0) | |
245 | goto out; | |
246 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
247 | l4proto->ctl_table, | |
248 | l4proto->ctl_table_users); | |
249 | } | |
250 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
251 | out: | |
933a41e7 | 252 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
253 | return err; |
254 | } | |
255 | ||
256 | static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) | |
257 | { | |
258 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
259 | if (l4proto->ctl_table_header != NULL && |
260 | *l4proto->ctl_table_header != NULL) | |
261 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
262 | l4proto->ctl_table, | |
263 | l4proto->ctl_table_users); | |
a999e683 PM |
264 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
265 | if (l4proto->ctl_compat_table_header != NULL) | |
266 | nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, | |
267 | l4proto->ctl_compat_table, NULL); | |
268 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 | 269 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
270 | } |
271 | ||
8f03dea5 MJ |
272 | /* FIXME: Allow NULL functions and sub in pointers to generic for |
273 | them. --RR */ | |
605dcad6 | 274 | int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 MJ |
275 | { |
276 | int ret = 0; | |
277 | ||
0661cca9 PM |
278 | if (l4proto->l3proto >= PF_MAX) |
279 | return -EBUSY; | |
ae5718fb | 280 | |
b19caa0c | 281 | mutex_lock(&nf_ct_proto_mutex); |
c6a1e615 | 282 | if (!nf_ct_protos[l4proto->l3proto]) { |
8f03dea5 | 283 | /* l3proto may be loaded latter. */ |
605dcad6 | 284 | struct nf_conntrack_l4proto **proto_array; |
8f03dea5 MJ |
285 | int i; |
286 | ||
c6a1e615 PM |
287 | proto_array = kmalloc(MAX_NF_CT_PROTO * |
288 | sizeof(struct nf_conntrack_l4proto *), | |
289 | GFP_KERNEL); | |
8f03dea5 MJ |
290 | if (proto_array == NULL) { |
291 | ret = -ENOMEM; | |
b19caa0c | 292 | goto out_unlock; |
8f03dea5 | 293 | } |
c6a1e615 | 294 | |
8f03dea5 | 295 | for (i = 0; i < MAX_NF_CT_PROTO; i++) |
605dcad6 | 296 | proto_array[i] = &nf_conntrack_l4proto_generic; |
c6a1e615 PM |
297 | nf_ct_protos[l4proto->l3proto] = proto_array; |
298 | } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != | |
299 | &nf_conntrack_l4proto_generic) { | |
300 | ret = -EBUSY; | |
301 | goto out_unlock; | |
8f03dea5 MJ |
302 | } |
303 | ||
d62f9ed4 PM |
304 | ret = nf_ct_l4proto_register_sysctl(l4proto); |
305 | if (ret < 0) | |
0661cca9 PM |
306 | goto out_unlock; |
307 | ||
c6a1e615 PM |
308 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
309 | l4proto); | |
8f03dea5 MJ |
310 | |
311 | out_unlock: | |
b19caa0c | 312 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
313 | return ret; |
314 | } | |
13b18339 | 315 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register); |
8f03dea5 | 316 | |
fe3eb20c | 317 | void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 | 318 | { |
fe3eb20c | 319 | BUG_ON(l4proto->l3proto >= PF_MAX); |
ae5718fb | 320 | |
b19caa0c | 321 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 322 | BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto); |
923f4902 PM |
323 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
324 | &nf_conntrack_l4proto_generic); | |
0661cca9 | 325 | nf_ct_l4proto_unregister_sysctl(l4proto); |
b19caa0c | 326 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 327 | |
0661cca9 | 328 | synchronize_rcu(); |
d62f9ed4 | 329 | |
8f03dea5 | 330 | /* Remove all contrack entries for this protocol */ |
605dcad6 | 331 | nf_ct_iterate_cleanup(kill_l4proto, l4proto); |
8f03dea5 | 332 | } |
13b18339 | 333 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister); |
ac5357eb PM |
334 | |
335 | int nf_conntrack_proto_init(void) | |
336 | { | |
337 | unsigned int i; | |
338 | int err; | |
339 | ||
340 | err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic); | |
341 | if (err < 0) | |
342 | return err; | |
343 | ||
344 | for (i = 0; i < AF_MAX; i++) | |
345 | rcu_assign_pointer(nf_ct_l3protos[i], | |
346 | &nf_conntrack_l3proto_generic); | |
347 | return 0; | |
348 | } | |
349 | ||
350 | void nf_conntrack_proto_fini(void) | |
351 | { | |
352 | unsigned int i; | |
353 | ||
354 | nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic); | |
355 | ||
356 | /* free l3proto protocol tables */ | |
357 | for (i = 0; i < PF_MAX; i++) | |
358 | kfree(nf_ct_protos[i]); | |
359 | } |