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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 | |
d52ed437 | 23 | static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct) |
84f3bb9a | 24 | { |
84f3bb9a PM |
25 | /* Previously seen (loopback)? Ignore. */ |
26 | if (skb->nfct != NULL) | |
27 | return XT_CONTINUE; | |
28 | ||
27e7190e ED |
29 | /* special case the untracked ct : we want the percpu object */ |
30 | if (!ct) | |
31 | ct = nf_ct_untracked_get(); | |
84f3bb9a PM |
32 | atomic_inc(&ct->ct_general.use); |
33 | skb->nfct = &ct->ct_general; | |
34 | skb->nfctinfo = IP_CT_NEW; | |
35 | ||
36 | return XT_CONTINUE; | |
37 | } | |
38 | ||
d52ed437 | 39 | static unsigned int xt_ct_target_v0(struct sk_buff *skb, |
24de58f4 PNA |
40 | const struct xt_action_param *par) |
41 | { | |
d52ed437 | 42 | const struct xt_ct_target_info *info = par->targinfo; |
24de58f4 PNA |
43 | struct nf_conn *ct = info->ct; |
44 | ||
d52ed437 PNA |
45 | return xt_ct_target(skb, ct); |
46 | } | |
24de58f4 | 47 | |
d52ed437 PNA |
48 | static unsigned int xt_ct_target_v1(struct sk_buff *skb, |
49 | const struct xt_action_param *par) | |
50 | { | |
51 | const struct xt_ct_target_info_v1 *info = par->targinfo; | |
52 | struct nf_conn *ct = info->ct; | |
24de58f4 | 53 | |
d52ed437 | 54 | return xt_ct_target(skb, ct); |
24de58f4 PNA |
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 | ||
ee14186f PNA |
107 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
108 | static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout) | |
109 | { | |
110 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
111 | ||
112 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
113 | if (timeout_put) | |
114 | timeout_put(timeout); | |
115 | } | |
116 | #endif | |
117 | ||
236df005 PNA |
118 | static int |
119 | xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par, | |
120 | const char *timeout_name) | |
121 | { | |
122 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT | |
123 | typeof(nf_ct_timeout_find_get_hook) timeout_find_get; | |
124 | struct ctnl_timeout *timeout; | |
125 | struct nf_conn_timeout *timeout_ext; | |
236df005 PNA |
126 | struct nf_conntrack_l4proto *l4proto; |
127 | int ret = 0; | |
0153d5a8 | 128 | u8 proto; |
236df005 PNA |
129 | |
130 | rcu_read_lock(); | |
131 | timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook); | |
132 | if (timeout_find_get == NULL) { | |
133 | ret = -ENOENT; | |
134 | pr_info("Timeout policy base is empty\n"); | |
135 | goto out; | |
136 | } | |
137 | ||
0153d5a8 PNA |
138 | proto = xt_ct_find_proto(par); |
139 | if (!proto) { | |
236df005 | 140 | ret = -EINVAL; |
0153d5a8 PNA |
141 | pr_info("You must specify a L4 protocol, and not use " |
142 | "inversions on it.\n"); | |
236df005 PNA |
143 | goto out; |
144 | } | |
145 | ||
19576c94 | 146 | timeout = timeout_find_get(par->net, timeout_name); |
236df005 PNA |
147 | if (timeout == NULL) { |
148 | ret = -ENOENT; | |
149 | pr_info("No such timeout policy \"%s\"\n", timeout_name); | |
150 | goto out; | |
151 | } | |
152 | ||
153 | if (timeout->l3num != par->family) { | |
154 | ret = -EINVAL; | |
155 | pr_info("Timeout policy `%s' can only be used by L3 protocol " | |
156 | "number %d\n", timeout_name, timeout->l3num); | |
157 | goto err_put_timeout; | |
158 | } | |
159 | /* Make sure the timeout policy matches any existing protocol tracker, | |
160 | * otherwise default to generic. | |
161 | */ | |
0153d5a8 | 162 | l4proto = __nf_ct_l4proto_find(par->family, proto); |
236df005 PNA |
163 | if (timeout->l4proto->l4proto != l4proto->l4proto) { |
164 | ret = -EINVAL; | |
165 | pr_info("Timeout policy `%s' can only be used by L4 protocol " | |
166 | "number %d\n", | |
167 | timeout_name, timeout->l4proto->l4proto); | |
168 | goto err_put_timeout; | |
169 | } | |
170 | timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC); | |
171 | if (timeout_ext == NULL) | |
172 | ret = -ENOMEM; | |
173 | ||
403d89ad PNA |
174 | rcu_read_unlock(); |
175 | return ret; | |
176 | ||
236df005 PNA |
177 | err_put_timeout: |
178 | __xt_ct_tg_timeout_put(timeout); | |
179 | out: | |
180 | rcu_read_unlock(); | |
181 | return ret; | |
182 | #else | |
183 | return -EOPNOTSUPP; | |
184 | #endif | |
185 | } | |
186 | ||
deedb590 DB |
187 | static u16 xt_ct_flags_to_dir(const struct xt_ct_target_info_v1 *info) |
188 | { | |
189 | switch (info->flags & (XT_CT_ZONE_DIR_ORIG | | |
190 | XT_CT_ZONE_DIR_REPL)) { | |
191 | case XT_CT_ZONE_DIR_ORIG: | |
192 | return NF_CT_ZONE_DIR_ORIG; | |
193 | case XT_CT_ZONE_DIR_REPL: | |
194 | return NF_CT_ZONE_DIR_REPL; | |
195 | default: | |
196 | return NF_CT_DEFAULT_ZONE_DIR; | |
197 | } | |
198 | } | |
199 | ||
d52ed437 PNA |
200 | static int xt_ct_tg_check(const struct xt_tgchk_param *par, |
201 | struct xt_ct_target_info_v1 *info) | |
24de58f4 | 202 | { |
308ac914 | 203 | struct nf_conntrack_zone zone; |
24de58f4 | 204 | struct nf_conn *ct; |
4610476d | 205 | int ret = -EOPNOTSUPP; |
236df005 | 206 | |
24de58f4 | 207 | if (info->flags & XT_CT_NOTRACK) { |
27e7190e | 208 | ct = NULL; |
24de58f4 PNA |
209 | goto out; |
210 | } | |
211 | ||
212 | #ifndef CONFIG_NF_CONNTRACK_ZONES | |
deedb590 | 213 | if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG | |
5e8018fc DB |
214 | XT_CT_ZONE_DIR_REPL | |
215 | XT_CT_ZONE_MARK)) | |
24de58f4 PNA |
216 | goto err1; |
217 | #endif | |
218 | ||
ecb2421b | 219 | ret = nf_ct_netns_get(par->net, par->family); |
24de58f4 PNA |
220 | if (ret < 0) |
221 | goto err1; | |
222 | ||
308ac914 DB |
223 | memset(&zone, 0, sizeof(zone)); |
224 | zone.id = info->zone; | |
deedb590 | 225 | zone.dir = xt_ct_flags_to_dir(info); |
5e8018fc DB |
226 | if (info->flags & XT_CT_ZONE_MARK) |
227 | zone.flags |= NF_CT_FLAG_MARK; | |
308ac914 DB |
228 | |
229 | ct = nf_ct_tmpl_alloc(par->net, &zone, GFP_KERNEL); | |
1a727c63 DC |
230 | if (!ct) { |
231 | ret = -ENOMEM; | |
24de58f4 | 232 | goto err2; |
1a727c63 | 233 | } |
24de58f4 PNA |
234 | |
235 | ret = 0; | |
236 | if ((info->ct_events || info->exp_events) && | |
237 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
14abfa16 EL |
238 | GFP_KERNEL)) { |
239 | ret = -EINVAL; | |
24de58f4 | 240 | goto err3; |
14abfa16 | 241 | } |
24de58f4 PNA |
242 | |
243 | if (info->helper[0]) { | |
236df005 PNA |
244 | ret = xt_ct_set_helper(ct, info->helper, par); |
245 | if (ret < 0) | |
1afc5679 | 246 | goto err3; |
24de58f4 PNA |
247 | } |
248 | ||
6cf51852 | 249 | if (info->timeout[0]) { |
236df005 PNA |
250 | ret = xt_ct_set_timeout(ct, par, info->timeout); |
251 | if (ret < 0) | |
252 | goto err3; | |
24de58f4 | 253 | } |
0838aa7f PNA |
254 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); |
255 | nf_conntrack_get(&ct->ct_general); | |
24de58f4 PNA |
256 | out: |
257 | info->ct = ct; | |
258 | return 0; | |
259 | ||
260 | err3: | |
9cf94eab | 261 | nf_ct_tmpl_free(ct); |
24de58f4 | 262 | err2: |
ecb2421b | 263 | nf_ct_netns_put(par->net, par->family); |
24de58f4 PNA |
264 | err1: |
265 | return ret; | |
266 | } | |
267 | ||
d52ed437 | 268 | static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par) |
84f3bb9a PM |
269 | { |
270 | struct xt_ct_target_info *info = par->targinfo; | |
d52ed437 PNA |
271 | struct xt_ct_target_info_v1 info_v1 = { |
272 | .flags = info->flags, | |
273 | .zone = info->zone, | |
274 | .ct_events = info->ct_events, | |
275 | .exp_events = info->exp_events, | |
276 | }; | |
277 | int ret; | |
84f3bb9a | 278 | |
5474f57f PNA |
279 | if (info->flags & ~XT_CT_NOTRACK) |
280 | return -EINVAL; | |
281 | ||
d52ed437 | 282 | memcpy(info_v1.helper, info->helper, sizeof(info->helper)); |
84f3bb9a | 283 | |
d52ed437 PNA |
284 | ret = xt_ct_tg_check(par, &info_v1); |
285 | if (ret < 0) | |
286 | return ret; | |
287 | ||
288 | info->ct = info_v1.ct; | |
289 | ||
290 | return ret; | |
291 | } | |
292 | ||
293 | static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par) | |
294 | { | |
5474f57f PNA |
295 | struct xt_ct_target_info_v1 *info = par->targinfo; |
296 | ||
297 | if (info->flags & ~XT_CT_NOTRACK) | |
298 | return -EINVAL; | |
299 | ||
300 | return xt_ct_tg_check(par, par->targinfo); | |
301 | } | |
302 | ||
303 | static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par) | |
304 | { | |
305 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
306 | ||
307 | if (info->flags & ~XT_CT_MASK) | |
308 | return -EINVAL; | |
309 | ||
d52ed437 | 310 | return xt_ct_tg_check(par, par->targinfo); |
84f3bb9a PM |
311 | } |
312 | ||
236df005 | 313 | static void xt_ct_destroy_timeout(struct nf_conn *ct) |
24de58f4 | 314 | { |
24de58f4 PNA |
315 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
316 | struct nf_conn_timeout *timeout_ext; | |
317 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
236df005 PNA |
318 | |
319 | rcu_read_lock(); | |
320 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
321 | ||
322 | if (timeout_put) { | |
323 | timeout_ext = nf_ct_timeout_find(ct); | |
ae2d708e | 324 | if (timeout_ext) { |
236df005 | 325 | timeout_put(timeout_ext->timeout); |
ae2d708e PNA |
326 | RCU_INIT_POINTER(timeout_ext->timeout, NULL); |
327 | } | |
236df005 PNA |
328 | } |
329 | rcu_read_unlock(); | |
24de58f4 | 330 | #endif |
236df005 PNA |
331 | } |
332 | ||
d52ed437 PNA |
333 | static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par, |
334 | struct xt_ct_target_info_v1 *info) | |
236df005 | 335 | { |
236df005 PNA |
336 | struct nf_conn *ct = info->ct; |
337 | struct nf_conn_help *help; | |
338 | ||
27e7190e | 339 | if (ct && !nf_ct_is_untracked(ct)) { |
24de58f4 PNA |
340 | help = nfct_help(ct); |
341 | if (help) | |
342 | module_put(help->helper->me); | |
343 | ||
ecb2421b | 344 | nf_ct_netns_put(par->net, par->family); |
24de58f4 | 345 | |
236df005 | 346 | xt_ct_destroy_timeout(ct); |
27e7190e | 347 | nf_ct_put(info->ct); |
24de58f4 | 348 | } |
d52ed437 PNA |
349 | } |
350 | ||
351 | static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par) | |
352 | { | |
353 | struct xt_ct_target_info *info = par->targinfo; | |
354 | struct xt_ct_target_info_v1 info_v1 = { | |
355 | .flags = info->flags, | |
356 | .zone = info->zone, | |
357 | .ct_events = info->ct_events, | |
358 | .exp_events = info->exp_events, | |
359 | .ct = info->ct, | |
360 | }; | |
361 | memcpy(info_v1.helper, info->helper, sizeof(info->helper)); | |
362 | ||
363 | xt_ct_tg_destroy(par, &info_v1); | |
364 | } | |
365 | ||
366 | static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par) | |
367 | { | |
368 | xt_ct_tg_destroy(par, par->targinfo); | |
24de58f4 PNA |
369 | } |
370 | ||
371 | static struct xt_target xt_ct_tg_reg[] __read_mostly = { | |
372 | { | |
373 | .name = "CT", | |
374 | .family = NFPROTO_UNSPEC, | |
375 | .targetsize = sizeof(struct xt_ct_target_info), | |
376 | .checkentry = xt_ct_tg_check_v0, | |
377 | .destroy = xt_ct_tg_destroy_v0, | |
378 | .target = xt_ct_target_v0, | |
379 | .table = "raw", | |
380 | .me = THIS_MODULE, | |
381 | }, | |
382 | { | |
383 | .name = "CT", | |
384 | .family = NFPROTO_UNSPEC, | |
385 | .revision = 1, | |
386 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
387 | .checkentry = xt_ct_tg_check_v1, | |
388 | .destroy = xt_ct_tg_destroy_v1, | |
389 | .target = xt_ct_target_v1, | |
390 | .table = "raw", | |
391 | .me = THIS_MODULE, | |
392 | }, | |
5474f57f PNA |
393 | { |
394 | .name = "CT", | |
395 | .family = NFPROTO_UNSPEC, | |
396 | .revision = 2, | |
397 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
398 | .checkentry = xt_ct_tg_check_v2, | |
399 | .destroy = xt_ct_tg_destroy_v1, | |
400 | .target = xt_ct_target_v1, | |
401 | .table = "raw", | |
402 | .me = THIS_MODULE, | |
403 | }, | |
84f3bb9a PM |
404 | }; |
405 | ||
10db9069 PNA |
406 | static unsigned int |
407 | notrack_tg(struct sk_buff *skb, const struct xt_action_param *par) | |
408 | { | |
409 | /* Previously seen (loopback)? Ignore. */ | |
410 | if (skb->nfct != NULL) | |
411 | return XT_CONTINUE; | |
412 | ||
413 | skb->nfct = &nf_ct_untracked_get()->ct_general; | |
414 | skb->nfctinfo = IP_CT_NEW; | |
415 | nf_conntrack_get(skb->nfct); | |
416 | ||
417 | return XT_CONTINUE; | |
418 | } | |
419 | ||
420 | static int notrack_chk(const struct xt_tgchk_param *par) | |
421 | { | |
422 | if (!par->net->xt.notrack_deprecated_warning) { | |
423 | pr_info("netfilter: NOTRACK target is deprecated, " | |
424 | "use CT instead or upgrade iptables\n"); | |
425 | par->net->xt.notrack_deprecated_warning = true; | |
426 | } | |
427 | return 0; | |
428 | } | |
429 | ||
430 | static struct xt_target notrack_tg_reg __read_mostly = { | |
431 | .name = "NOTRACK", | |
432 | .revision = 0, | |
433 | .family = NFPROTO_UNSPEC, | |
434 | .checkentry = notrack_chk, | |
435 | .target = notrack_tg, | |
436 | .table = "raw", | |
437 | .me = THIS_MODULE, | |
438 | }; | |
439 | ||
84f3bb9a PM |
440 | static int __init xt_ct_tg_init(void) |
441 | { | |
10db9069 PNA |
442 | int ret; |
443 | ||
444 | ret = xt_register_target(¬rack_tg_reg); | |
445 | if (ret < 0) | |
446 | return ret; | |
447 | ||
448 | ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); | |
449 | if (ret < 0) { | |
450 | xt_unregister_target(¬rack_tg_reg); | |
451 | return ret; | |
452 | } | |
453 | return 0; | |
84f3bb9a PM |
454 | } |
455 | ||
456 | static void __exit xt_ct_tg_exit(void) | |
457 | { | |
24de58f4 | 458 | xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); |
10db9069 | 459 | xt_unregister_target(¬rack_tg_reg); |
84f3bb9a PM |
460 | } |
461 | ||
462 | module_init(xt_ct_tg_init); | |
463 | module_exit(xt_ct_tg_exit); | |
464 | ||
465 | MODULE_LICENSE("GPL"); | |
466 | MODULE_DESCRIPTION("Xtables: connection tracking target"); | |
467 | MODULE_ALIAS("ipt_CT"); | |
468 | MODULE_ALIAS("ip6t_CT"); | |
10db9069 PNA |
469 | MODULE_ALIAS("ipt_NOTRACK"); |
470 | MODULE_ALIAS("ip6t_NOTRACK"); |