Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...
[deliverable/linux.git] / net / netfilter / xt_CT.c
CommitLineData
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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>
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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>
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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 23static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct)
84f3bb9a 24{
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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();
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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 39static 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;
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43 struct nf_conn *ct = info->ct;
44
d52ed437
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45 return xt_ct_target(skb, ct);
46}
24de58f4 47
d52ed437
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48static 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);
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55}
56
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57static u8 xt_ct_find_proto(const struct xt_tgchk_param *par)
58{
076f7839 59 if (par->family == NFPROTO_IPV4) {
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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) {
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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
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75static int
76xt_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
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107#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
108static 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
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118static int
119xt_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;
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126 struct nf_conntrack_l4proto *l4proto;
127 int ret = 0;
0153d5a8 128 u8 proto;
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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
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138 proto = xt_ct_find_proto(par);
139 if (!proto) {
236df005 140 ret = -EINVAL;
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141 pr_info("You must specify a L4 protocol, and not use "
142 "inversions on it.\n");
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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);
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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
174err_put_timeout:
175 __xt_ct_tg_timeout_put(timeout);
176out:
177 rcu_read_unlock();
178 return ret;
179#else
180 return -EOPNOTSUPP;
181#endif
182}
183
d52ed437
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184static 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;
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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,
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214 GFP_KERNEL)) {
215 ret = -EINVAL;
24de58f4 216 goto err3;
14abfa16 217 }
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218
219 if (info->helper[0]) {
236df005
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220 ret = xt_ct_set_helper(ct, info->helper, par);
221 if (ret < 0)
1afc5679 222 goto err3;
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223 }
224
6cf51852 225 if (info->timeout[0]) {
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226 ret = xt_ct_set_timeout(ct, par, info->timeout);
227 if (ret < 0)
228 goto err3;
24de58f4 229 }
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230
231 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
232 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
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233
234 /* Overload tuple linked list to put us in template list. */
235 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
236 &par->net->ct.tmpl);
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237out:
238 info->ct = ct;
239 return 0;
240
241err3:
242 nf_conntrack_free(ct);
243err2:
244 nf_ct_l3proto_module_put(par->family);
245err1:
246 return ret;
247}
248
d52ed437 249static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
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250{
251 struct xt_ct_target_info *info = par->targinfo;
d52ed437
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252 struct xt_ct_target_info_v1 info_v1 = {
253 .flags = info->flags,
254 .zone = info->zone,
255 .ct_events = info->ct_events,
256 .exp_events = info->exp_events,
257 };
258 int ret;
84f3bb9a 259
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260 if (info->flags & ~XT_CT_NOTRACK)
261 return -EINVAL;
262
d52ed437 263 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
84f3bb9a 264
d52ed437
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265 ret = xt_ct_tg_check(par, &info_v1);
266 if (ret < 0)
267 return ret;
268
269 info->ct = info_v1.ct;
270
271 return ret;
272}
273
274static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
275{
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276 struct xt_ct_target_info_v1 *info = par->targinfo;
277
278 if (info->flags & ~XT_CT_NOTRACK)
279 return -EINVAL;
280
281 return xt_ct_tg_check(par, par->targinfo);
282}
283
284static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
285{
286 struct xt_ct_target_info_v1 *info = par->targinfo;
287
288 if (info->flags & ~XT_CT_MASK)
289 return -EINVAL;
290
d52ed437 291 return xt_ct_tg_check(par, par->targinfo);
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292}
293
236df005 294static void xt_ct_destroy_timeout(struct nf_conn *ct)
24de58f4 295{
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296#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
297 struct nf_conn_timeout *timeout_ext;
298 typeof(nf_ct_timeout_put_hook) timeout_put;
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299
300 rcu_read_lock();
301 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
302
303 if (timeout_put) {
304 timeout_ext = nf_ct_timeout_find(ct);
305 if (timeout_ext)
306 timeout_put(timeout_ext->timeout);
307 }
308 rcu_read_unlock();
24de58f4 309#endif
236df005
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310}
311
d52ed437
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312static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
313 struct xt_ct_target_info_v1 *info)
236df005 314{
236df005
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315 struct nf_conn *ct = info->ct;
316 struct nf_conn_help *help;
317
27e7190e 318 if (ct && !nf_ct_is_untracked(ct)) {
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319 help = nfct_help(ct);
320 if (help)
321 module_put(help->helper->me);
322
323 nf_ct_l3proto_module_put(par->family);
324
236df005 325 xt_ct_destroy_timeout(ct);
27e7190e 326 nf_ct_put(info->ct);
24de58f4 327 }
d52ed437
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328}
329
330static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
331{
332 struct xt_ct_target_info *info = par->targinfo;
333 struct xt_ct_target_info_v1 info_v1 = {
334 .flags = info->flags,
335 .zone = info->zone,
336 .ct_events = info->ct_events,
337 .exp_events = info->exp_events,
338 .ct = info->ct,
339 };
340 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
341
342 xt_ct_tg_destroy(par, &info_v1);
343}
344
345static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
346{
347 xt_ct_tg_destroy(par, par->targinfo);
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348}
349
350static struct xt_target xt_ct_tg_reg[] __read_mostly = {
351 {
352 .name = "CT",
353 .family = NFPROTO_UNSPEC,
354 .targetsize = sizeof(struct xt_ct_target_info),
355 .checkentry = xt_ct_tg_check_v0,
356 .destroy = xt_ct_tg_destroy_v0,
357 .target = xt_ct_target_v0,
358 .table = "raw",
359 .me = THIS_MODULE,
360 },
361 {
362 .name = "CT",
363 .family = NFPROTO_UNSPEC,
364 .revision = 1,
365 .targetsize = sizeof(struct xt_ct_target_info_v1),
366 .checkentry = xt_ct_tg_check_v1,
367 .destroy = xt_ct_tg_destroy_v1,
368 .target = xt_ct_target_v1,
369 .table = "raw",
370 .me = THIS_MODULE,
371 },
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372 {
373 .name = "CT",
374 .family = NFPROTO_UNSPEC,
375 .revision = 2,
376 .targetsize = sizeof(struct xt_ct_target_info_v1),
377 .checkentry = xt_ct_tg_check_v2,
378 .destroy = xt_ct_tg_destroy_v1,
379 .target = xt_ct_target_v1,
380 .table = "raw",
381 .me = THIS_MODULE,
382 },
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383};
384
10db9069
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385static unsigned int
386notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
387{
388 /* Previously seen (loopback)? Ignore. */
389 if (skb->nfct != NULL)
390 return XT_CONTINUE;
391
392 skb->nfct = &nf_ct_untracked_get()->ct_general;
393 skb->nfctinfo = IP_CT_NEW;
394 nf_conntrack_get(skb->nfct);
395
396 return XT_CONTINUE;
397}
398
399static int notrack_chk(const struct xt_tgchk_param *par)
400{
401 if (!par->net->xt.notrack_deprecated_warning) {
402 pr_info("netfilter: NOTRACK target is deprecated, "
403 "use CT instead or upgrade iptables\n");
404 par->net->xt.notrack_deprecated_warning = true;
405 }
406 return 0;
407}
408
409static struct xt_target notrack_tg_reg __read_mostly = {
410 .name = "NOTRACK",
411 .revision = 0,
412 .family = NFPROTO_UNSPEC,
413 .checkentry = notrack_chk,
414 .target = notrack_tg,
415 .table = "raw",
416 .me = THIS_MODULE,
417};
418
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419static int __init xt_ct_tg_init(void)
420{
10db9069
PNA
421 int ret;
422
423 ret = xt_register_target(&notrack_tg_reg);
424 if (ret < 0)
425 return ret;
426
427 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
428 if (ret < 0) {
429 xt_unregister_target(&notrack_tg_reg);
430 return ret;
431 }
432 return 0;
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433}
434
435static void __exit xt_ct_tg_exit(void)
436{
24de58f4 437 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
10db9069 438 xt_unregister_target(&notrack_tg_reg);
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439}
440
441module_init(xt_ct_tg_init);
442module_exit(xt_ct_tg_exit);
443
444MODULE_LICENSE("GPL");
445MODULE_DESCRIPTION("Xtables: connection tracking target");
446MODULE_ALIAS("ipt_CT");
447MODULE_ALIAS("ip6t_CT");
10db9069
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448MODULE_ALIAS("ipt_NOTRACK");
449MODULE_ALIAS("ip6t_NOTRACK");
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