]>
Commit | Line | Data |
---|---|---|
84f3bb9a PM |
1 | /* |
2 | * Copyright (c) 2010 Patrick McHardy <kaber@trash.net> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
a7fed762 | 8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
84f3bb9a | 9 | #include <linux/module.h> |
5a0e3ad6 | 10 | #include <linux/gfp.h> |
84f3bb9a | 11 | #include <linux/skbuff.h> |
84f3bb9a PM |
12 | #include <linux/netfilter_ipv4/ip_tables.h> |
13 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
14 | #include <linux/netfilter/x_tables.h> | |
15 | #include <linux/netfilter/xt_CT.h> | |
16 | #include <net/netfilter/nf_conntrack.h> | |
eeb4cb95 | 17 | #include <net/netfilter/nf_conntrack_l4proto.h> |
84f3bb9a PM |
18 | #include <net/netfilter/nf_conntrack_helper.h> |
19 | #include <net/netfilter/nf_conntrack_ecache.h> | |
24de58f4 | 20 | #include <net/netfilter/nf_conntrack_timeout.h> |
5d0aa2cc | 21 | #include <net/netfilter/nf_conntrack_zones.h> |
84f3bb9a | 22 | |
24de58f4 PNA |
23 | static unsigned int xt_ct_target_v0(struct sk_buff *skb, |
24 | const struct xt_action_param *par) | |
84f3bb9a PM |
25 | { |
26 | const struct xt_ct_target_info *info = par->targinfo; | |
27 | struct nf_conn *ct = info->ct; | |
28 | ||
29 | /* Previously seen (loopback)? Ignore. */ | |
30 | if (skb->nfct != NULL) | |
31 | return XT_CONTINUE; | |
32 | ||
33 | atomic_inc(&ct->ct_general.use); | |
34 | skb->nfct = &ct->ct_general; | |
35 | skb->nfctinfo = IP_CT_NEW; | |
36 | ||
37 | return XT_CONTINUE; | |
38 | } | |
39 | ||
24de58f4 PNA |
40 | static unsigned int xt_ct_target_v1(struct sk_buff *skb, |
41 | const struct xt_action_param *par) | |
42 | { | |
43 | const struct xt_ct_target_info_v1 *info = par->targinfo; | |
44 | struct nf_conn *ct = info->ct; | |
45 | ||
46 | /* Previously seen (loopback)? Ignore. */ | |
47 | if (skb->nfct != NULL) | |
48 | return XT_CONTINUE; | |
49 | ||
50 | atomic_inc(&ct->ct_general.use); | |
51 | skb->nfct = &ct->ct_general; | |
52 | skb->nfctinfo = IP_CT_NEW; | |
53 | ||
54 | return XT_CONTINUE; | |
55 | } | |
56 | ||
84f3bb9a PM |
57 | static u8 xt_ct_find_proto(const struct xt_tgchk_param *par) |
58 | { | |
076f7839 | 59 | if (par->family == NFPROTO_IPV4) { |
84f3bb9a PM |
60 | const struct ipt_entry *e = par->entryinfo; |
61 | ||
62 | if (e->ip.invflags & IPT_INV_PROTO) | |
63 | return 0; | |
64 | return e->ip.proto; | |
076f7839 | 65 | } else if (par->family == NFPROTO_IPV6) { |
84f3bb9a PM |
66 | const struct ip6t_entry *e = par->entryinfo; |
67 | ||
68 | if (e->ipv6.invflags & IP6T_INV_PROTO) | |
69 | return 0; | |
70 | return e->ipv6.proto; | |
71 | } else | |
72 | return 0; | |
73 | } | |
74 | ||
24de58f4 | 75 | static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par) |
84f3bb9a PM |
76 | { |
77 | struct xt_ct_target_info *info = par->targinfo; | |
78 | struct nf_conntrack_tuple t; | |
79 | struct nf_conn_help *help; | |
80 | struct nf_conn *ct; | |
4a5a5c73 | 81 | int ret = 0; |
84f3bb9a PM |
82 | u8 proto; |
83 | ||
9bf04646 PNA |
84 | if (info->flags & ~XT_CT_NOTRACK) |
85 | return -EINVAL; | |
84f3bb9a PM |
86 | |
87 | if (info->flags & XT_CT_NOTRACK) { | |
5bfddbd4 | 88 | ct = nf_ct_untracked_get(); |
84f3bb9a PM |
89 | atomic_inc(&ct->ct_general.use); |
90 | goto out; | |
91 | } | |
92 | ||
5d0aa2cc PM |
93 | #ifndef CONFIG_NF_CONNTRACK_ZONES |
94 | if (info->zone) | |
95 | goto err1; | |
96 | #endif | |
97 | ||
4a5a5c73 JE |
98 | ret = nf_ct_l3proto_try_module_get(par->family); |
99 | if (ret < 0) | |
84f3bb9a PM |
100 | goto err1; |
101 | ||
102 | memset(&t, 0, sizeof(t)); | |
5d0aa2cc | 103 | ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL); |
4a5a5c73 | 104 | ret = PTR_ERR(ct); |
84f3bb9a PM |
105 | if (IS_ERR(ct)) |
106 | goto err2; | |
107 | ||
4a5a5c73 | 108 | ret = 0; |
84f3bb9a PM |
109 | if ((info->ct_events || info->exp_events) && |
110 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
111 | GFP_KERNEL)) | |
112 | goto err3; | |
113 | ||
9bf04646 | 114 | if (info->helper[0]) { |
4a5a5c73 | 115 | ret = -ENOENT; |
84f3bb9a | 116 | proto = xt_ct_find_proto(par); |
a7fed762 JE |
117 | if (!proto) { |
118 | pr_info("You must specify a L4 protocol, " | |
119 | "and not use inversions on it.\n"); | |
84f3bb9a | 120 | goto err3; |
a7fed762 | 121 | } |
84f3bb9a | 122 | |
4a5a5c73 | 123 | ret = -ENOMEM; |
84f3bb9a PM |
124 | help = nf_ct_helper_ext_add(ct, GFP_KERNEL); |
125 | if (help == NULL) | |
126 | goto err3; | |
127 | ||
4a5a5c73 | 128 | ret = -ENOENT; |
84f3bb9a PM |
129 | help->helper = nf_conntrack_helper_try_module_get(info->helper, |
130 | par->family, | |
131 | proto); | |
a7fed762 JE |
132 | if (help->helper == NULL) { |
133 | pr_info("No such helper \"%s\"\n", info->helper); | |
84f3bb9a | 134 | goto err3; |
a7fed762 | 135 | } |
84f3bb9a PM |
136 | } |
137 | ||
138 | __set_bit(IPS_TEMPLATE_BIT, &ct->status); | |
139 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
140 | out: | |
141 | info->ct = ct; | |
d6b00a53 | 142 | return 0; |
84f3bb9a PM |
143 | |
144 | err3: | |
145 | nf_conntrack_free(ct); | |
146 | err2: | |
147 | nf_ct_l3proto_module_put(par->family); | |
148 | err1: | |
4a5a5c73 | 149 | return ret; |
84f3bb9a PM |
150 | } |
151 | ||
ee14186f PNA |
152 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
153 | static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout) | |
154 | { | |
155 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
156 | ||
157 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
158 | if (timeout_put) | |
159 | timeout_put(timeout); | |
160 | } | |
161 | #endif | |
162 | ||
24de58f4 PNA |
163 | static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par) |
164 | { | |
165 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
166 | struct nf_conntrack_tuple t; | |
167 | struct nf_conn_help *help; | |
168 | struct nf_conn *ct; | |
169 | int ret = 0; | |
170 | u8 proto; | |
ee14186f PNA |
171 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
172 | struct ctnl_timeout *timeout; | |
173 | #endif | |
24de58f4 PNA |
174 | if (info->flags & ~XT_CT_NOTRACK) |
175 | return -EINVAL; | |
176 | ||
177 | if (info->flags & XT_CT_NOTRACK) { | |
178 | ct = nf_ct_untracked_get(); | |
179 | atomic_inc(&ct->ct_general.use); | |
180 | goto out; | |
181 | } | |
182 | ||
183 | #ifndef CONFIG_NF_CONNTRACK_ZONES | |
184 | if (info->zone) | |
185 | goto err1; | |
186 | #endif | |
187 | ||
188 | ret = nf_ct_l3proto_try_module_get(par->family); | |
189 | if (ret < 0) | |
190 | goto err1; | |
191 | ||
192 | memset(&t, 0, sizeof(t)); | |
193 | ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL); | |
194 | ret = PTR_ERR(ct); | |
195 | if (IS_ERR(ct)) | |
196 | goto err2; | |
197 | ||
198 | ret = 0; | |
199 | if ((info->ct_events || info->exp_events) && | |
200 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
201 | GFP_KERNEL)) | |
202 | goto err3; | |
203 | ||
204 | if (info->helper[0]) { | |
205 | ret = -ENOENT; | |
206 | proto = xt_ct_find_proto(par); | |
207 | if (!proto) { | |
208 | pr_info("You must specify a L4 protocol, " | |
209 | "and not use inversions on it.\n"); | |
210 | goto err3; | |
211 | } | |
212 | ||
213 | ret = -ENOMEM; | |
214 | help = nf_ct_helper_ext_add(ct, GFP_KERNEL); | |
215 | if (help == NULL) | |
216 | goto err3; | |
217 | ||
218 | ret = -ENOENT; | |
219 | help->helper = nf_conntrack_helper_try_module_get(info->helper, | |
220 | par->family, | |
221 | proto); | |
222 | if (help->helper == NULL) { | |
223 | pr_info("No such helper \"%s\"\n", info->helper); | |
224 | goto err3; | |
225 | } | |
226 | } | |
227 | ||
228 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT | |
6cf51852 | 229 | if (info->timeout[0]) { |
24de58f4 | 230 | typeof(nf_ct_timeout_find_get_hook) timeout_find_get; |
24de58f4 PNA |
231 | struct nf_conn_timeout *timeout_ext; |
232 | ||
1ac0bf99 | 233 | rcu_read_lock(); |
24de58f4 PNA |
234 | timeout_find_get = |
235 | rcu_dereference(nf_ct_timeout_find_get_hook); | |
236 | ||
237 | if (timeout_find_get) { | |
238 | const struct ipt_entry *e = par->entryinfo; | |
eeb4cb95 | 239 | struct nf_conntrack_l4proto *l4proto; |
24de58f4 PNA |
240 | |
241 | if (e->ip.invflags & IPT_INV_PROTO) { | |
242 | ret = -EINVAL; | |
243 | pr_info("You cannot use inversion on " | |
244 | "L4 protocol\n"); | |
1ac0bf99 | 245 | goto err4; |
24de58f4 PNA |
246 | } |
247 | timeout = timeout_find_get(info->timeout); | |
248 | if (timeout == NULL) { | |
249 | ret = -ENOENT; | |
250 | pr_info("No such timeout policy \"%s\"\n", | |
251 | info->timeout); | |
1ac0bf99 | 252 | goto err4; |
24de58f4 PNA |
253 | } |
254 | if (timeout->l3num != par->family) { | |
255 | ret = -EINVAL; | |
256 | pr_info("Timeout policy `%s' can only be " | |
257 | "used by L3 protocol number %d\n", | |
258 | info->timeout, timeout->l3num); | |
ee14186f | 259 | goto err5; |
24de58f4 | 260 | } |
eeb4cb95 PNA |
261 | /* Make sure the timeout policy matches any existing |
262 | * protocol tracker, otherwise default to generic. | |
263 | */ | |
264 | l4proto = __nf_ct_l4proto_find(par->family, | |
265 | e->ip.proto); | |
266 | if (timeout->l4proto->l4proto != l4proto->l4proto) { | |
24de58f4 PNA |
267 | ret = -EINVAL; |
268 | pr_info("Timeout policy `%s' can only be " | |
269 | "used by L4 protocol number %d\n", | |
c1ebd7df PNA |
270 | info->timeout, |
271 | timeout->l4proto->l4proto); | |
ee14186f | 272 | goto err5; |
24de58f4 PNA |
273 | } |
274 | timeout_ext = nf_ct_timeout_ext_add(ct, timeout, | |
ca53e440 | 275 | GFP_ATOMIC); |
24de58f4 PNA |
276 | if (timeout_ext == NULL) { |
277 | ret = -ENOMEM; | |
ee14186f | 278 | goto err5; |
24de58f4 PNA |
279 | } |
280 | } else { | |
281 | ret = -ENOENT; | |
282 | pr_info("Timeout policy base is empty\n"); | |
1ac0bf99 | 283 | goto err4; |
24de58f4 | 284 | } |
1ac0bf99 | 285 | rcu_read_unlock(); |
24de58f4 PNA |
286 | } |
287 | #endif | |
288 | ||
289 | __set_bit(IPS_TEMPLATE_BIT, &ct->status); | |
290 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
291 | out: | |
292 | info->ct = ct; | |
293 | return 0; | |
294 | ||
44b52bcc | 295 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
ee14186f PNA |
296 | err5: |
297 | __xt_ct_tg_timeout_put(timeout); | |
1ac0bf99 PNA |
298 | err4: |
299 | rcu_read_unlock(); | |
44b52bcc | 300 | #endif |
24de58f4 PNA |
301 | err3: |
302 | nf_conntrack_free(ct); | |
303 | err2: | |
304 | nf_ct_l3proto_module_put(par->family); | |
305 | err1: | |
306 | return ret; | |
307 | } | |
308 | ||
309 | static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par) | |
84f3bb9a PM |
310 | { |
311 | struct xt_ct_target_info *info = par->targinfo; | |
312 | struct nf_conn *ct = info->ct; | |
313 | struct nf_conn_help *help; | |
314 | ||
5bfddbd4 | 315 | if (!nf_ct_is_untracked(ct)) { |
84f3bb9a PM |
316 | help = nfct_help(ct); |
317 | if (help) | |
318 | module_put(help->helper->me); | |
319 | ||
320 | nf_ct_l3proto_module_put(par->family); | |
321 | } | |
322 | nf_ct_put(info->ct); | |
323 | } | |
324 | ||
24de58f4 PNA |
325 | static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par) |
326 | { | |
327 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
328 | struct nf_conn *ct = info->ct; | |
329 | struct nf_conn_help *help; | |
330 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT | |
331 | struct nf_conn_timeout *timeout_ext; | |
332 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
333 | #endif | |
334 | if (!nf_ct_is_untracked(ct)) { | |
335 | help = nfct_help(ct); | |
336 | if (help) | |
337 | module_put(help->helper->me); | |
338 | ||
339 | nf_ct_l3proto_module_put(par->family); | |
340 | ||
341 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT | |
1ac0bf99 | 342 | rcu_read_lock(); |
24de58f4 PNA |
343 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); |
344 | ||
345 | if (timeout_put) { | |
346 | timeout_ext = nf_ct_timeout_find(ct); | |
347 | if (timeout_ext) | |
348 | timeout_put(timeout_ext->timeout); | |
349 | } | |
1ac0bf99 | 350 | rcu_read_unlock(); |
24de58f4 PNA |
351 | #endif |
352 | } | |
353 | nf_ct_put(info->ct); | |
354 | } | |
355 | ||
356 | static struct xt_target xt_ct_tg_reg[] __read_mostly = { | |
357 | { | |
358 | .name = "CT", | |
359 | .family = NFPROTO_UNSPEC, | |
360 | .targetsize = sizeof(struct xt_ct_target_info), | |
361 | .checkentry = xt_ct_tg_check_v0, | |
362 | .destroy = xt_ct_tg_destroy_v0, | |
363 | .target = xt_ct_target_v0, | |
364 | .table = "raw", | |
365 | .me = THIS_MODULE, | |
366 | }, | |
367 | { | |
368 | .name = "CT", | |
369 | .family = NFPROTO_UNSPEC, | |
370 | .revision = 1, | |
371 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
372 | .checkentry = xt_ct_tg_check_v1, | |
373 | .destroy = xt_ct_tg_destroy_v1, | |
374 | .target = xt_ct_target_v1, | |
375 | .table = "raw", | |
376 | .me = THIS_MODULE, | |
377 | }, | |
84f3bb9a PM |
378 | }; |
379 | ||
380 | static int __init xt_ct_tg_init(void) | |
381 | { | |
24de58f4 | 382 | return xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); |
84f3bb9a PM |
383 | } |
384 | ||
385 | static void __exit xt_ct_tg_exit(void) | |
386 | { | |
24de58f4 | 387 | xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); |
84f3bb9a PM |
388 | } |
389 | ||
390 | module_init(xt_ct_tg_init); | |
391 | module_exit(xt_ct_tg_exit); | |
392 | ||
393 | MODULE_LICENSE("GPL"); | |
394 | MODULE_DESCRIPTION("Xtables: connection tracking target"); | |
395 | MODULE_ALIAS("ipt_CT"); | |
396 | MODULE_ALIAS("ip6t_CT"); |