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 | { | |
149 | return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == | |
150 | ((struct nf_conntrack_l3proto *)data)->l3proto); | |
151 | } | |
152 | ||
605dcad6 | 153 | static int kill_l4proto(struct nf_conn *i, void *data) |
8f03dea5 | 154 | { |
605dcad6 MJ |
155 | struct nf_conntrack_l4proto *l4proto; |
156 | l4proto = (struct nf_conntrack_l4proto *)data; | |
8f03dea5 | 157 | return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum == |
605dcad6 | 158 | l4proto->l4proto) && |
8f03dea5 | 159 | (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num == |
605dcad6 | 160 | l4proto->l3proto); |
8f03dea5 MJ |
161 | } |
162 | ||
d62f9ed4 PM |
163 | static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto) |
164 | { | |
165 | int err = 0; | |
166 | ||
167 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
168 | if (l3proto->ctl_table != NULL) { |
169 | err = nf_ct_register_sysctl(&l3proto->ctl_table_header, | |
170 | l3proto->ctl_table_path, | |
171 | l3proto->ctl_table, NULL); | |
172 | } | |
d62f9ed4 PM |
173 | #endif |
174 | return err; | |
175 | } | |
176 | ||
177 | static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) | |
178 | { | |
179 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
180 | if (l3proto->ctl_table_header != NULL) |
181 | nf_ct_unregister_sysctl(&l3proto->ctl_table_header, | |
182 | l3proto->ctl_table, NULL); | |
d62f9ed4 PM |
183 | #endif |
184 | } | |
185 | ||
8f03dea5 MJ |
186 | int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) |
187 | { | |
188 | int ret = 0; | |
189 | ||
0661cca9 PM |
190 | if (proto->l3proto >= AF_MAX) |
191 | return -EBUSY; | |
ae5718fb | 192 | |
b19caa0c | 193 | mutex_lock(&nf_ct_proto_mutex); |
605dcad6 | 194 | if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { |
8f03dea5 | 195 | ret = -EBUSY; |
ae5718fb | 196 | goto out_unlock; |
8f03dea5 | 197 | } |
d62f9ed4 PM |
198 | |
199 | ret = nf_ct_l3proto_register_sysctl(proto); | |
200 | if (ret < 0) | |
0661cca9 PM |
201 | goto out_unlock; |
202 | ||
203 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); | |
8f03dea5 | 204 | |
ae5718fb | 205 | out_unlock: |
b19caa0c | 206 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
207 | return ret; |
208 | } | |
13b18339 | 209 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register); |
8f03dea5 | 210 | |
fe3eb20c | 211 | void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto) |
8f03dea5 | 212 | { |
fe3eb20c | 213 | BUG_ON(proto->l3proto >= AF_MAX); |
ae5718fb | 214 | |
b19caa0c | 215 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 216 | BUG_ON(nf_ct_l3protos[proto->l3proto] != proto); |
923f4902 PM |
217 | rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], |
218 | &nf_conntrack_l3proto_generic); | |
0661cca9 | 219 | nf_ct_l3proto_unregister_sysctl(proto); |
b19caa0c | 220 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 221 | |
0661cca9 | 222 | synchronize_rcu(); |
d62f9ed4 | 223 | |
8f03dea5 MJ |
224 | /* Remove all contrack entries for this protocol */ |
225 | nf_ct_iterate_cleanup(kill_l3proto, proto); | |
226 | } | |
13b18339 | 227 | EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister); |
8f03dea5 | 228 | |
d62f9ed4 PM |
229 | static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto) |
230 | { | |
231 | int err = 0; | |
232 | ||
233 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
234 | if (l4proto->ctl_table != NULL) { |
235 | err = nf_ct_register_sysctl(l4proto->ctl_table_header, | |
236 | nf_net_netfilter_sysctl_path, | |
237 | l4proto->ctl_table, | |
238 | l4proto->ctl_table_users); | |
a999e683 PM |
239 | if (err < 0) |
240 | goto out; | |
d62f9ed4 | 241 | } |
a999e683 PM |
242 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
243 | if (l4proto->ctl_compat_table != NULL) { | |
244 | err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header, | |
245 | nf_net_ipv4_netfilter_sysctl_path, | |
246 | l4proto->ctl_compat_table, NULL); | |
247 | if (err == 0) | |
248 | goto out; | |
249 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
250 | l4proto->ctl_table, | |
251 | l4proto->ctl_table_users); | |
252 | } | |
253 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
254 | out: | |
933a41e7 | 255 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
256 | return err; |
257 | } | |
258 | ||
259 | static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) | |
260 | { | |
261 | #ifdef CONFIG_SYSCTL | |
d62f9ed4 PM |
262 | if (l4proto->ctl_table_header != NULL && |
263 | *l4proto->ctl_table_header != NULL) | |
264 | nf_ct_unregister_sysctl(l4proto->ctl_table_header, | |
265 | l4proto->ctl_table, | |
266 | l4proto->ctl_table_users); | |
a999e683 PM |
267 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
268 | if (l4proto->ctl_compat_table_header != NULL) | |
269 | nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, | |
270 | l4proto->ctl_compat_table, NULL); | |
271 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 | 272 | #endif /* CONFIG_SYSCTL */ |
d62f9ed4 PM |
273 | } |
274 | ||
8f03dea5 MJ |
275 | /* FIXME: Allow NULL functions and sub in pointers to generic for |
276 | them. --RR */ | |
605dcad6 | 277 | int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 MJ |
278 | { |
279 | int ret = 0; | |
280 | ||
0661cca9 PM |
281 | if (l4proto->l3proto >= PF_MAX) |
282 | return -EBUSY; | |
ae5718fb | 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; |
c6a1e615 PM |
300 | nf_ct_protos[l4proto->l3proto] = proto_array; |
301 | } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != | |
302 | &nf_conntrack_l4proto_generic) { | |
303 | ret = -EBUSY; | |
304 | goto out_unlock; | |
8f03dea5 MJ |
305 | } |
306 | ||
d62f9ed4 PM |
307 | ret = nf_ct_l4proto_register_sysctl(l4proto); |
308 | if (ret < 0) | |
0661cca9 PM |
309 | goto out_unlock; |
310 | ||
c6a1e615 PM |
311 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
312 | l4proto); | |
8f03dea5 MJ |
313 | |
314 | out_unlock: | |
b19caa0c | 315 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 MJ |
316 | return ret; |
317 | } | |
13b18339 | 318 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register); |
8f03dea5 | 319 | |
fe3eb20c | 320 | void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto) |
8f03dea5 | 321 | { |
fe3eb20c | 322 | BUG_ON(l4proto->l3proto >= PF_MAX); |
ae5718fb | 323 | |
b19caa0c | 324 | mutex_lock(&nf_ct_proto_mutex); |
fe3eb20c | 325 | BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto); |
923f4902 PM |
326 | rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], |
327 | &nf_conntrack_l4proto_generic); | |
0661cca9 | 328 | nf_ct_l4proto_unregister_sysctl(l4proto); |
b19caa0c | 329 | mutex_unlock(&nf_ct_proto_mutex); |
8f03dea5 | 330 | |
0661cca9 | 331 | synchronize_rcu(); |
d62f9ed4 | 332 | |
8f03dea5 | 333 | /* Remove all contrack entries for this protocol */ |
605dcad6 | 334 | nf_ct_iterate_cleanup(kill_l4proto, l4proto); |
8f03dea5 | 335 | } |
13b18339 | 336 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister); |
ac5357eb PM |
337 | |
338 | int nf_conntrack_proto_init(void) | |
339 | { | |
340 | unsigned int i; | |
341 | int err; | |
342 | ||
343 | err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic); | |
344 | if (err < 0) | |
345 | return err; | |
346 | ||
347 | for (i = 0; i < AF_MAX; i++) | |
348 | rcu_assign_pointer(nf_ct_l3protos[i], | |
349 | &nf_conntrack_l3proto_generic); | |
350 | return 0; | |
351 | } | |
352 | ||
353 | void nf_conntrack_proto_fini(void) | |
354 | { | |
355 | unsigned int i; | |
356 | ||
357 | nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic); | |
358 | ||
359 | /* free l3proto protocol tables */ | |
360 | for (i = 0; i < PF_MAX; i++) | |
361 | kfree(nf_ct_protos[i]); | |
362 | } |