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Commit | Line | Data |
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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 | ||
236df005 PNA |
75 | static int |
76 | xt_ct_set_helper(struct nf_conn *ct, const char *helper_name, | |
77 | const struct xt_tgchk_param *par) | |
78 | { | |
79 | struct nf_conntrack_helper *helper; | |
80 | struct nf_conn_help *help; | |
81 | u8 proto; | |
82 | ||
83 | proto = xt_ct_find_proto(par); | |
84 | if (!proto) { | |
85 | pr_info("You must specify a L4 protocol, and not use " | |
86 | "inversions on it.\n"); | |
87 | return -ENOENT; | |
88 | } | |
89 | ||
90 | helper = nf_conntrack_helper_try_module_get(helper_name, par->family, | |
91 | proto); | |
92 | if (helper == NULL) { | |
93 | pr_info("No such helper \"%s\"\n", helper_name); | |
94 | return -ENOENT; | |
95 | } | |
96 | ||
97 | help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL); | |
98 | if (help == NULL) { | |
99 | module_put(helper->me); | |
100 | return -ENOMEM; | |
101 | } | |
102 | ||
103 | help->helper = helper; | |
104 | return 0; | |
105 | } | |
106 | ||
24de58f4 | 107 | static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par) |
84f3bb9a PM |
108 | { |
109 | struct xt_ct_target_info *info = par->targinfo; | |
110 | struct nf_conntrack_tuple t; | |
84f3bb9a | 111 | struct nf_conn *ct; |
4610476d | 112 | int ret = -EOPNOTSUPP; |
84f3bb9a | 113 | |
9bf04646 PNA |
114 | if (info->flags & ~XT_CT_NOTRACK) |
115 | return -EINVAL; | |
84f3bb9a PM |
116 | |
117 | if (info->flags & XT_CT_NOTRACK) { | |
5bfddbd4 | 118 | ct = nf_ct_untracked_get(); |
84f3bb9a PM |
119 | atomic_inc(&ct->ct_general.use); |
120 | goto out; | |
121 | } | |
122 | ||
5d0aa2cc PM |
123 | #ifndef CONFIG_NF_CONNTRACK_ZONES |
124 | if (info->zone) | |
125 | goto err1; | |
126 | #endif | |
127 | ||
4a5a5c73 JE |
128 | ret = nf_ct_l3proto_try_module_get(par->family); |
129 | if (ret < 0) | |
84f3bb9a PM |
130 | goto err1; |
131 | ||
132 | memset(&t, 0, sizeof(t)); | |
5d0aa2cc | 133 | ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL); |
4a5a5c73 | 134 | ret = PTR_ERR(ct); |
84f3bb9a PM |
135 | if (IS_ERR(ct)) |
136 | goto err2; | |
137 | ||
4a5a5c73 | 138 | ret = 0; |
84f3bb9a PM |
139 | if ((info->ct_events || info->exp_events) && |
140 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
141 | GFP_KERNEL)) | |
142 | goto err3; | |
143 | ||
9bf04646 | 144 | if (info->helper[0]) { |
236df005 PNA |
145 | ret = xt_ct_set_helper(ct, info->helper, par); |
146 | if (ret < 0) | |
1afc5679 | 147 | goto err3; |
84f3bb9a PM |
148 | } |
149 | ||
150 | __set_bit(IPS_TEMPLATE_BIT, &ct->status); | |
151 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
252b3e8c PNA |
152 | |
153 | /* Overload tuple linked list to put us in template list. */ | |
154 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
155 | &par->net->ct.tmpl); | |
84f3bb9a PM |
156 | out: |
157 | info->ct = ct; | |
d6b00a53 | 158 | return 0; |
84f3bb9a PM |
159 | |
160 | err3: | |
161 | nf_conntrack_free(ct); | |
162 | err2: | |
163 | nf_ct_l3proto_module_put(par->family); | |
164 | err1: | |
4a5a5c73 | 165 | return ret; |
84f3bb9a PM |
166 | } |
167 | ||
ee14186f PNA |
168 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
169 | static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout) | |
170 | { | |
171 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
172 | ||
173 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
174 | if (timeout_put) | |
175 | timeout_put(timeout); | |
176 | } | |
177 | #endif | |
178 | ||
236df005 PNA |
179 | static int |
180 | xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par, | |
181 | const char *timeout_name) | |
182 | { | |
183 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT | |
184 | typeof(nf_ct_timeout_find_get_hook) timeout_find_get; | |
185 | struct ctnl_timeout *timeout; | |
186 | struct nf_conn_timeout *timeout_ext; | |
236df005 PNA |
187 | struct nf_conntrack_l4proto *l4proto; |
188 | int ret = 0; | |
0153d5a8 | 189 | u8 proto; |
236df005 PNA |
190 | |
191 | rcu_read_lock(); | |
192 | timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook); | |
193 | if (timeout_find_get == NULL) { | |
194 | ret = -ENOENT; | |
195 | pr_info("Timeout policy base is empty\n"); | |
196 | goto out; | |
197 | } | |
198 | ||
0153d5a8 PNA |
199 | proto = xt_ct_find_proto(par); |
200 | if (!proto) { | |
236df005 | 201 | ret = -EINVAL; |
0153d5a8 PNA |
202 | pr_info("You must specify a L4 protocol, and not use " |
203 | "inversions on it.\n"); | |
236df005 PNA |
204 | goto out; |
205 | } | |
206 | ||
207 | timeout = timeout_find_get(timeout_name); | |
208 | if (timeout == NULL) { | |
209 | ret = -ENOENT; | |
210 | pr_info("No such timeout policy \"%s\"\n", timeout_name); | |
211 | goto out; | |
212 | } | |
213 | ||
214 | if (timeout->l3num != par->family) { | |
215 | ret = -EINVAL; | |
216 | pr_info("Timeout policy `%s' can only be used by L3 protocol " | |
217 | "number %d\n", timeout_name, timeout->l3num); | |
218 | goto err_put_timeout; | |
219 | } | |
220 | /* Make sure the timeout policy matches any existing protocol tracker, | |
221 | * otherwise default to generic. | |
222 | */ | |
0153d5a8 | 223 | l4proto = __nf_ct_l4proto_find(par->family, proto); |
236df005 PNA |
224 | if (timeout->l4proto->l4proto != l4proto->l4proto) { |
225 | ret = -EINVAL; | |
226 | pr_info("Timeout policy `%s' can only be used by L4 protocol " | |
227 | "number %d\n", | |
228 | timeout_name, timeout->l4proto->l4proto); | |
229 | goto err_put_timeout; | |
230 | } | |
231 | timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC); | |
232 | if (timeout_ext == NULL) | |
233 | ret = -ENOMEM; | |
234 | ||
235 | err_put_timeout: | |
236 | __xt_ct_tg_timeout_put(timeout); | |
237 | out: | |
238 | rcu_read_unlock(); | |
239 | return ret; | |
240 | #else | |
241 | return -EOPNOTSUPP; | |
242 | #endif | |
243 | } | |
244 | ||
24de58f4 PNA |
245 | static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par) |
246 | { | |
247 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
248 | struct nf_conntrack_tuple t; | |
24de58f4 | 249 | struct nf_conn *ct; |
4610476d | 250 | int ret = -EOPNOTSUPP; |
236df005 | 251 | |
24de58f4 PNA |
252 | if (info->flags & ~XT_CT_NOTRACK) |
253 | return -EINVAL; | |
254 | ||
255 | if (info->flags & XT_CT_NOTRACK) { | |
256 | ct = nf_ct_untracked_get(); | |
257 | atomic_inc(&ct->ct_general.use); | |
258 | goto out; | |
259 | } | |
260 | ||
261 | #ifndef CONFIG_NF_CONNTRACK_ZONES | |
262 | if (info->zone) | |
263 | goto err1; | |
264 | #endif | |
265 | ||
266 | ret = nf_ct_l3proto_try_module_get(par->family); | |
267 | if (ret < 0) | |
268 | goto err1; | |
269 | ||
270 | memset(&t, 0, sizeof(t)); | |
271 | ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL); | |
272 | ret = PTR_ERR(ct); | |
273 | if (IS_ERR(ct)) | |
274 | goto err2; | |
275 | ||
276 | ret = 0; | |
277 | if ((info->ct_events || info->exp_events) && | |
278 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
279 | GFP_KERNEL)) | |
280 | goto err3; | |
281 | ||
282 | if (info->helper[0]) { | |
236df005 PNA |
283 | ret = xt_ct_set_helper(ct, info->helper, par); |
284 | if (ret < 0) | |
1afc5679 | 285 | goto err3; |
24de58f4 PNA |
286 | } |
287 | ||
6cf51852 | 288 | if (info->timeout[0]) { |
236df005 PNA |
289 | ret = xt_ct_set_timeout(ct, par, info->timeout); |
290 | if (ret < 0) | |
291 | goto err3; | |
24de58f4 | 292 | } |
24de58f4 PNA |
293 | |
294 | __set_bit(IPS_TEMPLATE_BIT, &ct->status); | |
295 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
252b3e8c PNA |
296 | |
297 | /* Overload tuple linked list to put us in template list. */ | |
298 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
299 | &par->net->ct.tmpl); | |
24de58f4 PNA |
300 | out: |
301 | info->ct = ct; | |
302 | return 0; | |
303 | ||
304 | err3: | |
305 | nf_conntrack_free(ct); | |
306 | err2: | |
307 | nf_ct_l3proto_module_put(par->family); | |
308 | err1: | |
309 | return ret; | |
310 | } | |
311 | ||
312 | static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par) | |
84f3bb9a PM |
313 | { |
314 | struct xt_ct_target_info *info = par->targinfo; | |
315 | struct nf_conn *ct = info->ct; | |
316 | struct nf_conn_help *help; | |
317 | ||
5bfddbd4 | 318 | if (!nf_ct_is_untracked(ct)) { |
84f3bb9a PM |
319 | help = nfct_help(ct); |
320 | if (help) | |
321 | module_put(help->helper->me); | |
322 | ||
323 | nf_ct_l3proto_module_put(par->family); | |
324 | } | |
325 | nf_ct_put(info->ct); | |
326 | } | |
327 | ||
236df005 | 328 | static void xt_ct_destroy_timeout(struct nf_conn *ct) |
24de58f4 | 329 | { |
24de58f4 PNA |
330 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
331 | struct nf_conn_timeout *timeout_ext; | |
332 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
236df005 PNA |
333 | |
334 | rcu_read_lock(); | |
335 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
336 | ||
337 | if (timeout_put) { | |
338 | timeout_ext = nf_ct_timeout_find(ct); | |
339 | if (timeout_ext) | |
340 | timeout_put(timeout_ext->timeout); | |
341 | } | |
342 | rcu_read_unlock(); | |
24de58f4 | 343 | #endif |
236df005 PNA |
344 | } |
345 | ||
346 | static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par) | |
347 | { | |
348 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
349 | struct nf_conn *ct = info->ct; | |
350 | struct nf_conn_help *help; | |
351 | ||
24de58f4 PNA |
352 | if (!nf_ct_is_untracked(ct)) { |
353 | help = nfct_help(ct); | |
354 | if (help) | |
355 | module_put(help->helper->me); | |
356 | ||
357 | nf_ct_l3proto_module_put(par->family); | |
358 | ||
236df005 | 359 | xt_ct_destroy_timeout(ct); |
24de58f4 PNA |
360 | } |
361 | nf_ct_put(info->ct); | |
362 | } | |
363 | ||
364 | static struct xt_target xt_ct_tg_reg[] __read_mostly = { | |
365 | { | |
366 | .name = "CT", | |
367 | .family = NFPROTO_UNSPEC, | |
368 | .targetsize = sizeof(struct xt_ct_target_info), | |
369 | .checkentry = xt_ct_tg_check_v0, | |
370 | .destroy = xt_ct_tg_destroy_v0, | |
371 | .target = xt_ct_target_v0, | |
372 | .table = "raw", | |
373 | .me = THIS_MODULE, | |
374 | }, | |
375 | { | |
376 | .name = "CT", | |
377 | .family = NFPROTO_UNSPEC, | |
378 | .revision = 1, | |
379 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
380 | .checkentry = xt_ct_tg_check_v1, | |
381 | .destroy = xt_ct_tg_destroy_v1, | |
382 | .target = xt_ct_target_v1, | |
383 | .table = "raw", | |
384 | .me = THIS_MODULE, | |
385 | }, | |
84f3bb9a PM |
386 | }; |
387 | ||
10db9069 PNA |
388 | static unsigned int |
389 | notrack_tg(struct sk_buff *skb, const struct xt_action_param *par) | |
390 | { | |
391 | /* Previously seen (loopback)? Ignore. */ | |
392 | if (skb->nfct != NULL) | |
393 | return XT_CONTINUE; | |
394 | ||
395 | skb->nfct = &nf_ct_untracked_get()->ct_general; | |
396 | skb->nfctinfo = IP_CT_NEW; | |
397 | nf_conntrack_get(skb->nfct); | |
398 | ||
399 | return XT_CONTINUE; | |
400 | } | |
401 | ||
402 | static int notrack_chk(const struct xt_tgchk_param *par) | |
403 | { | |
404 | if (!par->net->xt.notrack_deprecated_warning) { | |
405 | pr_info("netfilter: NOTRACK target is deprecated, " | |
406 | "use CT instead or upgrade iptables\n"); | |
407 | par->net->xt.notrack_deprecated_warning = true; | |
408 | } | |
409 | return 0; | |
410 | } | |
411 | ||
412 | static struct xt_target notrack_tg_reg __read_mostly = { | |
413 | .name = "NOTRACK", | |
414 | .revision = 0, | |
415 | .family = NFPROTO_UNSPEC, | |
416 | .checkentry = notrack_chk, | |
417 | .target = notrack_tg, | |
418 | .table = "raw", | |
419 | .me = THIS_MODULE, | |
420 | }; | |
421 | ||
84f3bb9a PM |
422 | static int __init xt_ct_tg_init(void) |
423 | { | |
10db9069 PNA |
424 | int ret; |
425 | ||
426 | ret = xt_register_target(¬rack_tg_reg); | |
427 | if (ret < 0) | |
428 | return ret; | |
429 | ||
430 | ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); | |
431 | if (ret < 0) { | |
432 | xt_unregister_target(¬rack_tg_reg); | |
433 | return ret; | |
434 | } | |
435 | return 0; | |
84f3bb9a PM |
436 | } |
437 | ||
438 | static void __exit xt_ct_tg_exit(void) | |
439 | { | |
24de58f4 | 440 | xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); |
10db9069 | 441 | xt_unregister_target(¬rack_tg_reg); |
84f3bb9a PM |
442 | } |
443 | ||
444 | module_init(xt_ct_tg_init); | |
445 | module_exit(xt_ct_tg_exit); | |
446 | ||
447 | MODULE_LICENSE("GPL"); | |
448 | MODULE_DESCRIPTION("Xtables: connection tracking target"); | |
449 | MODULE_ALIAS("ipt_CT"); | |
450 | MODULE_ALIAS("ip6t_CT"); | |
10db9069 PNA |
451 | MODULE_ALIAS("ipt_NOTRACK"); |
452 | MODULE_ALIAS("ip6t_NOTRACK"); |