Merge 3.4-rc6 into usb-next
[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>
c1ebd7df 20#include <net/netfilter/nf_conntrack_l4proto.h>
24de58f4 21#include <net/netfilter/nf_conntrack_timeout.h>
5d0aa2cc 22#include <net/netfilter/nf_conntrack_zones.h>
84f3bb9a 23
24de58f4
PNA
24static unsigned int xt_ct_target_v0(struct sk_buff *skb,
25 const struct xt_action_param *par)
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26{
27 const struct xt_ct_target_info *info = par->targinfo;
28 struct nf_conn *ct = info->ct;
29
30 /* Previously seen (loopback)? Ignore. */
31 if (skb->nfct != NULL)
32 return XT_CONTINUE;
33
34 atomic_inc(&ct->ct_general.use);
35 skb->nfct = &ct->ct_general;
36 skb->nfctinfo = IP_CT_NEW;
37
38 return XT_CONTINUE;
39}
40
24de58f4
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41static unsigned int xt_ct_target_v1(struct sk_buff *skb,
42 const struct xt_action_param *par)
43{
44 const struct xt_ct_target_info_v1 *info = par->targinfo;
45 struct nf_conn *ct = info->ct;
46
47 /* Previously seen (loopback)? Ignore. */
48 if (skb->nfct != NULL)
49 return XT_CONTINUE;
50
51 atomic_inc(&ct->ct_general.use);
52 skb->nfct = &ct->ct_general;
53 skb->nfctinfo = IP_CT_NEW;
54
55 return XT_CONTINUE;
56}
57
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58static u8 xt_ct_find_proto(const struct xt_tgchk_param *par)
59{
076f7839 60 if (par->family == NFPROTO_IPV4) {
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61 const struct ipt_entry *e = par->entryinfo;
62
63 if (e->ip.invflags & IPT_INV_PROTO)
64 return 0;
65 return e->ip.proto;
076f7839 66 } else if (par->family == NFPROTO_IPV6) {
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67 const struct ip6t_entry *e = par->entryinfo;
68
69 if (e->ipv6.invflags & IP6T_INV_PROTO)
70 return 0;
71 return e->ipv6.proto;
72 } else
73 return 0;
74}
75
24de58f4 76static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
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77{
78 struct xt_ct_target_info *info = par->targinfo;
79 struct nf_conntrack_tuple t;
80 struct nf_conn_help *help;
81 struct nf_conn *ct;
4a5a5c73 82 int ret = 0;
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83 u8 proto;
84
9bf04646
PNA
85 if (info->flags & ~XT_CT_NOTRACK)
86 return -EINVAL;
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87
88 if (info->flags & XT_CT_NOTRACK) {
5bfddbd4 89 ct = nf_ct_untracked_get();
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90 atomic_inc(&ct->ct_general.use);
91 goto out;
92 }
93
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94#ifndef CONFIG_NF_CONNTRACK_ZONES
95 if (info->zone)
96 goto err1;
97#endif
98
4a5a5c73
JE
99 ret = nf_ct_l3proto_try_module_get(par->family);
100 if (ret < 0)
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101 goto err1;
102
103 memset(&t, 0, sizeof(t));
5d0aa2cc 104 ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
4a5a5c73 105 ret = PTR_ERR(ct);
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106 if (IS_ERR(ct))
107 goto err2;
108
4a5a5c73 109 ret = 0;
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110 if ((info->ct_events || info->exp_events) &&
111 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
112 GFP_KERNEL))
113 goto err3;
114
9bf04646 115 if (info->helper[0]) {
4a5a5c73 116 ret = -ENOENT;
84f3bb9a 117 proto = xt_ct_find_proto(par);
a7fed762
JE
118 if (!proto) {
119 pr_info("You must specify a L4 protocol, "
120 "and not use inversions on it.\n");
84f3bb9a 121 goto err3;
a7fed762 122 }
84f3bb9a 123
4a5a5c73 124 ret = -ENOMEM;
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125 help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
126 if (help == NULL)
127 goto err3;
128
4a5a5c73 129 ret = -ENOENT;
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130 help->helper = nf_conntrack_helper_try_module_get(info->helper,
131 par->family,
132 proto);
a7fed762
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133 if (help->helper == NULL) {
134 pr_info("No such helper \"%s\"\n", info->helper);
84f3bb9a 135 goto err3;
a7fed762 136 }
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137 }
138
139 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
140 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
141out:
142 info->ct = ct;
d6b00a53 143 return 0;
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144
145err3:
146 nf_conntrack_free(ct);
147err2:
148 nf_ct_l3proto_module_put(par->family);
149err1:
4a5a5c73 150 return ret;
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151}
152
ee14186f
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153#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
154static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
155{
156 typeof(nf_ct_timeout_put_hook) timeout_put;
157
158 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
159 if (timeout_put)
160 timeout_put(timeout);
161}
162#endif
163
24de58f4
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164static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
165{
166 struct xt_ct_target_info_v1 *info = par->targinfo;
167 struct nf_conntrack_tuple t;
168 struct nf_conn_help *help;
169 struct nf_conn *ct;
170 int ret = 0;
171 u8 proto;
ee14186f
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172#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
173 struct ctnl_timeout *timeout;
174#endif
24de58f4
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175 if (info->flags & ~XT_CT_NOTRACK)
176 return -EINVAL;
177
178 if (info->flags & XT_CT_NOTRACK) {
179 ct = nf_ct_untracked_get();
180 atomic_inc(&ct->ct_general.use);
181 goto out;
182 }
183
184#ifndef CONFIG_NF_CONNTRACK_ZONES
185 if (info->zone)
186 goto err1;
187#endif
188
189 ret = nf_ct_l3proto_try_module_get(par->family);
190 if (ret < 0)
191 goto err1;
192
193 memset(&t, 0, sizeof(t));
194 ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
195 ret = PTR_ERR(ct);
196 if (IS_ERR(ct))
197 goto err2;
198
199 ret = 0;
200 if ((info->ct_events || info->exp_events) &&
201 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
202 GFP_KERNEL))
203 goto err3;
204
205 if (info->helper[0]) {
206 ret = -ENOENT;
207 proto = xt_ct_find_proto(par);
208 if (!proto) {
209 pr_info("You must specify a L4 protocol, "
210 "and not use inversions on it.\n");
211 goto err3;
212 }
213
214 ret = -ENOMEM;
215 help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
216 if (help == NULL)
217 goto err3;
218
219 ret = -ENOENT;
220 help->helper = nf_conntrack_helper_try_module_get(info->helper,
221 par->family,
222 proto);
223 if (help->helper == NULL) {
224 pr_info("No such helper \"%s\"\n", info->helper);
225 goto err3;
226 }
227 }
228
229#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
6cf51852 230 if (info->timeout[0]) {
24de58f4 231 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
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232 struct nf_conn_timeout *timeout_ext;
233
1ac0bf99 234 rcu_read_lock();
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235 timeout_find_get =
236 rcu_dereference(nf_ct_timeout_find_get_hook);
237
238 if (timeout_find_get) {
239 const struct ipt_entry *e = par->entryinfo;
eeb4cb95 240 struct nf_conntrack_l4proto *l4proto;
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241
242 if (e->ip.invflags & IPT_INV_PROTO) {
243 ret = -EINVAL;
244 pr_info("You cannot use inversion on "
245 "L4 protocol\n");
1ac0bf99 246 goto err4;
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247 }
248 timeout = timeout_find_get(info->timeout);
249 if (timeout == NULL) {
250 ret = -ENOENT;
251 pr_info("No such timeout policy \"%s\"\n",
252 info->timeout);
1ac0bf99 253 goto err4;
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254 }
255 if (timeout->l3num != par->family) {
256 ret = -EINVAL;
257 pr_info("Timeout policy `%s' can only be "
258 "used by L3 protocol number %d\n",
259 info->timeout, timeout->l3num);
ee14186f 260 goto err5;
24de58f4 261 }
eeb4cb95
PNA
262 /* Make sure the timeout policy matches any existing
263 * protocol tracker, otherwise default to generic.
264 */
265 l4proto = __nf_ct_l4proto_find(par->family,
266 e->ip.proto);
267 if (timeout->l4proto->l4proto != l4proto->l4proto) {
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268 ret = -EINVAL;
269 pr_info("Timeout policy `%s' can only be "
270 "used by L4 protocol number %d\n",
c1ebd7df
PNA
271 info->timeout,
272 timeout->l4proto->l4proto);
ee14186f 273 goto err5;
24de58f4
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274 }
275 timeout_ext = nf_ct_timeout_ext_add(ct, timeout,
ca53e440 276 GFP_ATOMIC);
24de58f4
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277 if (timeout_ext == NULL) {
278 ret = -ENOMEM;
ee14186f 279 goto err5;
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280 }
281 } else {
282 ret = -ENOENT;
283 pr_info("Timeout policy base is empty\n");
1ac0bf99 284 goto err4;
24de58f4 285 }
1ac0bf99 286 rcu_read_unlock();
24de58f4
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287 }
288#endif
289
290 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
291 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
292out:
293 info->ct = ct;
294 return 0;
295
44b52bcc 296#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
ee14186f
PNA
297err5:
298 __xt_ct_tg_timeout_put(timeout);
1ac0bf99
PNA
299err4:
300 rcu_read_unlock();
44b52bcc 301#endif
24de58f4
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302err3:
303 nf_conntrack_free(ct);
304err2:
305 nf_ct_l3proto_module_put(par->family);
306err1:
307 return ret;
308}
309
310static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
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311{
312 struct xt_ct_target_info *info = par->targinfo;
313 struct nf_conn *ct = info->ct;
314 struct nf_conn_help *help;
315
5bfddbd4 316 if (!nf_ct_is_untracked(ct)) {
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317 help = nfct_help(ct);
318 if (help)
319 module_put(help->helper->me);
320
321 nf_ct_l3proto_module_put(par->family);
322 }
323 nf_ct_put(info->ct);
324}
325
24de58f4
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326static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
327{
328 struct xt_ct_target_info_v1 *info = par->targinfo;
329 struct nf_conn *ct = info->ct;
330 struct nf_conn_help *help;
331#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
332 struct nf_conn_timeout *timeout_ext;
333 typeof(nf_ct_timeout_put_hook) timeout_put;
334#endif
335 if (!nf_ct_is_untracked(ct)) {
336 help = nfct_help(ct);
337 if (help)
338 module_put(help->helper->me);
339
340 nf_ct_l3proto_module_put(par->family);
341
342#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1ac0bf99 343 rcu_read_lock();
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344 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
345
346 if (timeout_put) {
347 timeout_ext = nf_ct_timeout_find(ct);
348 if (timeout_ext)
349 timeout_put(timeout_ext->timeout);
350 }
1ac0bf99 351 rcu_read_unlock();
24de58f4
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352#endif
353 }
354 nf_ct_put(info->ct);
355}
356
357static struct xt_target xt_ct_tg_reg[] __read_mostly = {
358 {
359 .name = "CT",
360 .family = NFPROTO_UNSPEC,
361 .targetsize = sizeof(struct xt_ct_target_info),
362 .checkentry = xt_ct_tg_check_v0,
363 .destroy = xt_ct_tg_destroy_v0,
364 .target = xt_ct_target_v0,
365 .table = "raw",
366 .me = THIS_MODULE,
367 },
368 {
369 .name = "CT",
370 .family = NFPROTO_UNSPEC,
371 .revision = 1,
372 .targetsize = sizeof(struct xt_ct_target_info_v1),
373 .checkentry = xt_ct_tg_check_v1,
374 .destroy = xt_ct_tg_destroy_v1,
375 .target = xt_ct_target_v1,
376 .table = "raw",
377 .me = THIS_MODULE,
378 },
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379};
380
381static int __init xt_ct_tg_init(void)
382{
24de58f4 383 return xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
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384}
385
386static void __exit xt_ct_tg_exit(void)
387{
24de58f4 388 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
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389}
390
391module_init(xt_ct_tg_init);
392module_exit(xt_ct_tg_exit);
393
394MODULE_LICENSE("GPL");
395MODULE_DESCRIPTION("Xtables: connection tracking target");
396MODULE_ALIAS("ipt_CT");
397MODULE_ALIAS("ip6t_CT");
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