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 | |
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 | ||
146 | timeout = timeout_find_get(timeout_name); | |
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 | ||
174 | err_put_timeout: | |
175 | __xt_ct_tg_timeout_put(timeout); | |
176 | out: | |
177 | rcu_read_unlock(); | |
178 | return ret; | |
179 | #else | |
180 | return -EOPNOTSUPP; | |
181 | #endif | |
182 | } | |
183 | ||
d52ed437 PNA |
184 | static int xt_ct_tg_check(const struct xt_tgchk_param *par, |
185 | struct xt_ct_target_info_v1 *info) | |
24de58f4 | 186 | { |
24de58f4 | 187 | struct nf_conntrack_tuple t; |
24de58f4 | 188 | struct nf_conn *ct; |
4610476d | 189 | int ret = -EOPNOTSUPP; |
236df005 | 190 | |
24de58f4 | 191 | if (info->flags & XT_CT_NOTRACK) { |
27e7190e | 192 | ct = NULL; |
24de58f4 PNA |
193 | goto out; |
194 | } | |
195 | ||
196 | #ifndef CONFIG_NF_CONNTRACK_ZONES | |
197 | if (info->zone) | |
198 | goto err1; | |
199 | #endif | |
200 | ||
201 | ret = nf_ct_l3proto_try_module_get(par->family); | |
202 | if (ret < 0) | |
203 | goto err1; | |
204 | ||
205 | memset(&t, 0, sizeof(t)); | |
206 | ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL); | |
207 | ret = PTR_ERR(ct); | |
208 | if (IS_ERR(ct)) | |
209 | goto err2; | |
210 | ||
211 | ret = 0; | |
212 | if ((info->ct_events || info->exp_events) && | |
213 | !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events, | |
214 | GFP_KERNEL)) | |
215 | goto err3; | |
216 | ||
217 | if (info->helper[0]) { | |
236df005 PNA |
218 | ret = xt_ct_set_helper(ct, info->helper, par); |
219 | if (ret < 0) | |
1afc5679 | 220 | goto err3; |
24de58f4 PNA |
221 | } |
222 | ||
6cf51852 | 223 | if (info->timeout[0]) { |
236df005 PNA |
224 | ret = xt_ct_set_timeout(ct, par, info->timeout); |
225 | if (ret < 0) | |
226 | goto err3; | |
24de58f4 | 227 | } |
24de58f4 PNA |
228 | |
229 | __set_bit(IPS_TEMPLATE_BIT, &ct->status); | |
230 | __set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
252b3e8c PNA |
231 | |
232 | /* Overload tuple linked list to put us in template list. */ | |
233 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
234 | &par->net->ct.tmpl); | |
24de58f4 PNA |
235 | out: |
236 | info->ct = ct; | |
237 | return 0; | |
238 | ||
239 | err3: | |
240 | nf_conntrack_free(ct); | |
241 | err2: | |
242 | nf_ct_l3proto_module_put(par->family); | |
243 | err1: | |
244 | return ret; | |
245 | } | |
246 | ||
d52ed437 | 247 | static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par) |
84f3bb9a PM |
248 | { |
249 | struct xt_ct_target_info *info = par->targinfo; | |
d52ed437 PNA |
250 | struct xt_ct_target_info_v1 info_v1 = { |
251 | .flags = info->flags, | |
252 | .zone = info->zone, | |
253 | .ct_events = info->ct_events, | |
254 | .exp_events = info->exp_events, | |
255 | }; | |
256 | int ret; | |
84f3bb9a | 257 | |
5474f57f PNA |
258 | if (info->flags & ~XT_CT_NOTRACK) |
259 | return -EINVAL; | |
260 | ||
d52ed437 | 261 | memcpy(info_v1.helper, info->helper, sizeof(info->helper)); |
84f3bb9a | 262 | |
d52ed437 PNA |
263 | ret = xt_ct_tg_check(par, &info_v1); |
264 | if (ret < 0) | |
265 | return ret; | |
266 | ||
267 | info->ct = info_v1.ct; | |
268 | ||
269 | return ret; | |
270 | } | |
271 | ||
272 | static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par) | |
273 | { | |
5474f57f PNA |
274 | struct xt_ct_target_info_v1 *info = par->targinfo; |
275 | ||
276 | if (info->flags & ~XT_CT_NOTRACK) | |
277 | return -EINVAL; | |
278 | ||
279 | return xt_ct_tg_check(par, par->targinfo); | |
280 | } | |
281 | ||
282 | static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par) | |
283 | { | |
284 | struct xt_ct_target_info_v1 *info = par->targinfo; | |
285 | ||
286 | if (info->flags & ~XT_CT_MASK) | |
287 | return -EINVAL; | |
288 | ||
d52ed437 | 289 | return xt_ct_tg_check(par, par->targinfo); |
84f3bb9a PM |
290 | } |
291 | ||
236df005 | 292 | static void xt_ct_destroy_timeout(struct nf_conn *ct) |
24de58f4 | 293 | { |
24de58f4 PNA |
294 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
295 | struct nf_conn_timeout *timeout_ext; | |
296 | typeof(nf_ct_timeout_put_hook) timeout_put; | |
236df005 PNA |
297 | |
298 | rcu_read_lock(); | |
299 | timeout_put = rcu_dereference(nf_ct_timeout_put_hook); | |
300 | ||
301 | if (timeout_put) { | |
302 | timeout_ext = nf_ct_timeout_find(ct); | |
303 | if (timeout_ext) | |
304 | timeout_put(timeout_ext->timeout); | |
305 | } | |
306 | rcu_read_unlock(); | |
24de58f4 | 307 | #endif |
236df005 PNA |
308 | } |
309 | ||
d52ed437 PNA |
310 | static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par, |
311 | struct xt_ct_target_info_v1 *info) | |
236df005 | 312 | { |
236df005 PNA |
313 | struct nf_conn *ct = info->ct; |
314 | struct nf_conn_help *help; | |
315 | ||
27e7190e | 316 | if (ct && !nf_ct_is_untracked(ct)) { |
24de58f4 PNA |
317 | help = nfct_help(ct); |
318 | if (help) | |
319 | module_put(help->helper->me); | |
320 | ||
321 | nf_ct_l3proto_module_put(par->family); | |
322 | ||
236df005 | 323 | xt_ct_destroy_timeout(ct); |
27e7190e | 324 | nf_ct_put(info->ct); |
24de58f4 | 325 | } |
d52ed437 PNA |
326 | } |
327 | ||
328 | static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par) | |
329 | { | |
330 | struct xt_ct_target_info *info = par->targinfo; | |
331 | struct xt_ct_target_info_v1 info_v1 = { | |
332 | .flags = info->flags, | |
333 | .zone = info->zone, | |
334 | .ct_events = info->ct_events, | |
335 | .exp_events = info->exp_events, | |
336 | .ct = info->ct, | |
337 | }; | |
338 | memcpy(info_v1.helper, info->helper, sizeof(info->helper)); | |
339 | ||
340 | xt_ct_tg_destroy(par, &info_v1); | |
341 | } | |
342 | ||
343 | static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par) | |
344 | { | |
345 | xt_ct_tg_destroy(par, par->targinfo); | |
24de58f4 PNA |
346 | } |
347 | ||
348 | static struct xt_target xt_ct_tg_reg[] __read_mostly = { | |
349 | { | |
350 | .name = "CT", | |
351 | .family = NFPROTO_UNSPEC, | |
352 | .targetsize = sizeof(struct xt_ct_target_info), | |
353 | .checkentry = xt_ct_tg_check_v0, | |
354 | .destroy = xt_ct_tg_destroy_v0, | |
355 | .target = xt_ct_target_v0, | |
356 | .table = "raw", | |
357 | .me = THIS_MODULE, | |
358 | }, | |
359 | { | |
360 | .name = "CT", | |
361 | .family = NFPROTO_UNSPEC, | |
362 | .revision = 1, | |
363 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
364 | .checkentry = xt_ct_tg_check_v1, | |
365 | .destroy = xt_ct_tg_destroy_v1, | |
366 | .target = xt_ct_target_v1, | |
367 | .table = "raw", | |
368 | .me = THIS_MODULE, | |
369 | }, | |
5474f57f PNA |
370 | { |
371 | .name = "CT", | |
372 | .family = NFPROTO_UNSPEC, | |
373 | .revision = 2, | |
374 | .targetsize = sizeof(struct xt_ct_target_info_v1), | |
375 | .checkentry = xt_ct_tg_check_v2, | |
376 | .destroy = xt_ct_tg_destroy_v1, | |
377 | .target = xt_ct_target_v1, | |
378 | .table = "raw", | |
379 | .me = THIS_MODULE, | |
380 | }, | |
84f3bb9a PM |
381 | }; |
382 | ||
10db9069 PNA |
383 | static unsigned int |
384 | notrack_tg(struct sk_buff *skb, const struct xt_action_param *par) | |
385 | { | |
386 | /* Previously seen (loopback)? Ignore. */ | |
387 | if (skb->nfct != NULL) | |
388 | return XT_CONTINUE; | |
389 | ||
390 | skb->nfct = &nf_ct_untracked_get()->ct_general; | |
391 | skb->nfctinfo = IP_CT_NEW; | |
392 | nf_conntrack_get(skb->nfct); | |
393 | ||
394 | return XT_CONTINUE; | |
395 | } | |
396 | ||
397 | static int notrack_chk(const struct xt_tgchk_param *par) | |
398 | { | |
399 | if (!par->net->xt.notrack_deprecated_warning) { | |
400 | pr_info("netfilter: NOTRACK target is deprecated, " | |
401 | "use CT instead or upgrade iptables\n"); | |
402 | par->net->xt.notrack_deprecated_warning = true; | |
403 | } | |
404 | return 0; | |
405 | } | |
406 | ||
407 | static struct xt_target notrack_tg_reg __read_mostly = { | |
408 | .name = "NOTRACK", | |
409 | .revision = 0, | |
410 | .family = NFPROTO_UNSPEC, | |
411 | .checkentry = notrack_chk, | |
412 | .target = notrack_tg, | |
413 | .table = "raw", | |
414 | .me = THIS_MODULE, | |
415 | }; | |
416 | ||
84f3bb9a PM |
417 | static int __init xt_ct_tg_init(void) |
418 | { | |
10db9069 PNA |
419 | int ret; |
420 | ||
421 | ret = xt_register_target(¬rack_tg_reg); | |
422 | if (ret < 0) | |
423 | return ret; | |
424 | ||
425 | ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); | |
426 | if (ret < 0) { | |
427 | xt_unregister_target(¬rack_tg_reg); | |
428 | return ret; | |
429 | } | |
430 | return 0; | |
84f3bb9a PM |
431 | } |
432 | ||
433 | static void __exit xt_ct_tg_exit(void) | |
434 | { | |
24de58f4 | 435 | xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg)); |
10db9069 | 436 | xt_unregister_target(¬rack_tg_reg); |
84f3bb9a PM |
437 | } |
438 | ||
439 | module_init(xt_ct_tg_init); | |
440 | module_exit(xt_ct_tg_exit); | |
441 | ||
442 | MODULE_LICENSE("GPL"); | |
443 | MODULE_DESCRIPTION("Xtables: connection tracking target"); | |
444 | MODULE_ALIAS("ipt_CT"); | |
445 | MODULE_ALIAS("ip6t_CT"); | |
10db9069 PNA |
446 | MODULE_ALIAS("ipt_NOTRACK"); |
447 | MODULE_ALIAS("ip6t_NOTRACK"); |