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13#include <linux/types.h>
14#include <linux/netfilter.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/mutex.h>
18#include <linux/vmalloc.h>
19#include <linux/stddef.h>
20#include <linux/err.h>
21#include <linux/percpu.h>
22#include <linux/notifier.h>
23#include <linux/kernel.h>
24#include <linux/netdevice.h>
25
26#include <net/netfilter/nf_conntrack.h>
27#include <net/netfilter/nf_conntrack_l3proto.h>
28#include <net/netfilter/nf_conntrack_l4proto.h>
29#include <net/netfilter/nf_conntrack_core.h>
30
31static struct nf_conntrack_l4proto __rcu **nf_ct_protos[PF_MAX] __read_mostly;
32struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX] __read_mostly;
33EXPORT_SYMBOL_GPL(nf_ct_l3protos);
34
35static DEFINE_MUTEX(nf_ct_proto_mutex);
36
37#ifdef CONFIG_SYSCTL
38static int
39nf_ct_register_sysctl(struct net *net,
40 struct ctl_table_header **header,
41 const char *path,
42 struct ctl_table *table)
43{
44 if (*header == NULL) {
45 *header = register_net_sysctl(net, path, table);
46 if (*header == NULL)
47 return -ENOMEM;
48 }
49
50 return 0;
51}
52
53static void
54nf_ct_unregister_sysctl(struct ctl_table_header **header,
55 struct ctl_table **table,
56 unsigned int users)
57{
58 if (users > 0)
59 return;
60
61 unregister_net_sysctl_table(*header);
62 kfree(*table);
63 *header = NULL;
64 *table = NULL;
65}
66#endif
67
68struct nf_conntrack_l4proto *
69__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
70{
71 if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL))
72 return &nf_conntrack_l4proto_generic;
73
74 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
75}
76EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
77
78
79
80struct nf_conntrack_l3proto *
81nf_ct_l3proto_find_get(u_int16_t l3proto)
82{
83 struct nf_conntrack_l3proto *p;
84
85 rcu_read_lock();
86 p = __nf_ct_l3proto_find(l3proto);
87 if (!try_module_get(p->me))
88 p = &nf_conntrack_l3proto_generic;
89 rcu_read_unlock();
90
91 return p;
92}
93EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
94
95void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
96{
97 module_put(p->me);
98}
99EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
100
101int
102nf_ct_l3proto_try_module_get(unsigned short l3proto)
103{
104 int ret;
105 struct nf_conntrack_l3proto *p;
106
107retry: p = nf_ct_l3proto_find_get(l3proto);
108 if (p == &nf_conntrack_l3proto_generic) {
109 ret = request_module("nf_conntrack-%d", l3proto);
110 if (!ret)
111 goto retry;
112
113 return -EPROTOTYPE;
114 }
115
116 return 0;
117}
118EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
119
120void nf_ct_l3proto_module_put(unsigned short l3proto)
121{
122 struct nf_conntrack_l3proto *p;
123
124
125
126
127 rcu_read_lock();
128 p = __nf_ct_l3proto_find(l3proto);
129 module_put(p->me);
130 rcu_read_unlock();
131}
132EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
133
134struct nf_conntrack_l4proto *
135nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
136{
137 struct nf_conntrack_l4proto *p;
138
139 rcu_read_lock();
140 p = __nf_ct_l4proto_find(l3num, l4num);
141 if (!try_module_get(p->me))
142 p = &nf_conntrack_l4proto_generic;
143 rcu_read_unlock();
144
145 return p;
146}
147EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
148
149void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
150{
151 module_put(p->me);
152}
153EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
154
155static int kill_l3proto(struct nf_conn *i, void *data)
156{
157 return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
158}
159
160static int kill_l4proto(struct nf_conn *i, void *data)
161{
162 struct nf_conntrack_l4proto *l4proto;
163 l4proto = (struct nf_conntrack_l4proto *)data;
164 return nf_ct_protonum(i) == l4proto->l4proto &&
165 nf_ct_l3num(i) == l4proto->l3proto;
166}
167
168static struct nf_ip_net *nf_ct_l3proto_net(struct net *net,
169 struct nf_conntrack_l3proto *l3proto)
170{
171 if (l3proto->l3proto == PF_INET)
172 return &net->ct.nf_ct_proto;
173 else
174 return NULL;
175}
176
177static int nf_ct_l3proto_register_sysctl(struct net *net,
178 struct nf_conntrack_l3proto *l3proto)
179{
180 int err = 0;
181 struct nf_ip_net *in = nf_ct_l3proto_net(net, l3proto);
182
183 if (in == NULL)
184 return 0;
185
186#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
187 if (in->ctl_table != NULL) {
188 err = nf_ct_register_sysctl(net,
189 &in->ctl_table_header,
190 l3proto->ctl_table_path,
191 in->ctl_table);
192 if (err < 0) {
193 kfree(in->ctl_table);
194 in->ctl_table = NULL;
195 }
196 }
197#endif
198 return err;
199}
200
201static void nf_ct_l3proto_unregister_sysctl(struct net *net,
202 struct nf_conntrack_l3proto *l3proto)
203{
204 struct nf_ip_net *in = nf_ct_l3proto_net(net, l3proto);
205
206 if (in == NULL)
207 return;
208#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
209 if (in->ctl_table_header != NULL)
210 nf_ct_unregister_sysctl(&in->ctl_table_header,
211 &in->ctl_table,
212 0);
213#endif
214}
215
216int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
217{
218 int ret = 0;
219 struct nf_conntrack_l3proto *old;
220
221 if (proto->l3proto >= AF_MAX)
222 return -EBUSY;
223
224 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
225 return -EINVAL;
226
227 mutex_lock(&nf_ct_proto_mutex);
228 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
229 lockdep_is_held(&nf_ct_proto_mutex));
230 if (old != &nf_conntrack_l3proto_generic) {
231 ret = -EBUSY;
232 goto out_unlock;
233 }
234
235 if (proto->nlattr_tuple_size)
236 proto->nla_size = 3 * proto->nlattr_tuple_size();
237
238 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
239
240out_unlock:
241 mutex_unlock(&nf_ct_proto_mutex);
242 return ret;
243
244}
245EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
246
247int nf_ct_l3proto_pernet_register(struct net *net,
248 struct nf_conntrack_l3proto *proto)
249{
250 int ret = 0;
251
252 if (proto->init_net) {
253 ret = proto->init_net(net);
254 if (ret < 0)
255 return ret;
256 }
257
258 return nf_ct_l3proto_register_sysctl(net, proto);
259}
260EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);
261
262void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
263{
264 BUG_ON(proto->l3proto >= AF_MAX);
265
266 mutex_lock(&nf_ct_proto_mutex);
267 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
268 lockdep_is_held(&nf_ct_proto_mutex)
269 ) != proto);
270 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
271 &nf_conntrack_l3proto_generic);
272 mutex_unlock(&nf_ct_proto_mutex);
273
274 synchronize_rcu();
275}
276EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
277
278void nf_ct_l3proto_pernet_unregister(struct net *net,
279 struct nf_conntrack_l3proto *proto)
280{
281 nf_ct_l3proto_unregister_sysctl(net, proto);
282
283
284 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
285}
286EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);
287
288static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
289 struct nf_conntrack_l4proto *l4proto)
290{
291 if (l4proto->get_net_proto) {
292
293 return l4proto->get_net_proto(net);
294 } else if (l4proto->net_id) {
295
296 return net_generic(net, *l4proto->net_id);
297 }
298 return NULL;
299}
300
301static
302int nf_ct_l4proto_register_sysctl(struct net *net,
303 struct nf_proto_net *pn,
304 struct nf_conntrack_l4proto *l4proto)
305{
306 int err = 0;
307
308#ifdef CONFIG_SYSCTL
309 if (pn->ctl_table != NULL) {
310 err = nf_ct_register_sysctl(net,
311 &pn->ctl_table_header,
312 "net/netfilter",
313 pn->ctl_table);
314 if (err < 0) {
315 if (!pn->users) {
316 kfree(pn->ctl_table);
317 pn->ctl_table = NULL;
318 }
319 }
320 }
321#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
322 if (l4proto->l3proto != AF_INET6 && pn->ctl_compat_table != NULL) {
323 if (err < 0) {
324 nf_ct_kfree_compat_sysctl_table(pn);
325 goto out;
326 }
327 err = nf_ct_register_sysctl(net,
328 &pn->ctl_compat_header,
329 "net/ipv4/netfilter",
330 pn->ctl_compat_table);
331 if (err == 0)
332 goto out;
333
334 nf_ct_kfree_compat_sysctl_table(pn);
335 nf_ct_unregister_sysctl(&pn->ctl_table_header,
336 &pn->ctl_table,
337 pn->users);
338 }
339out:
340#endif
341#endif
342 return err;
343}
344
345static
346void nf_ct_l4proto_unregister_sysctl(struct net *net,
347 struct nf_proto_net *pn,
348 struct nf_conntrack_l4proto *l4proto)
349{
350#ifdef CONFIG_SYSCTL
351 if (pn->ctl_table_header != NULL)
352 nf_ct_unregister_sysctl(&pn->ctl_table_header,
353 &pn->ctl_table,
354 pn->users);
355
356#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
357 if (l4proto->l3proto != AF_INET6 && pn->ctl_compat_header != NULL)
358 nf_ct_unregister_sysctl(&pn->ctl_compat_header,
359 &pn->ctl_compat_table,
360 0);
361#endif
362#endif
363}
364
365
366
367int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto)
368{
369 int ret = 0;
370
371 if (l4proto->l3proto >= PF_MAX)
372 return -EBUSY;
373
374 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
375 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
376 return -EINVAL;
377
378 mutex_lock(&nf_ct_proto_mutex);
379 if (!nf_ct_protos[l4proto->l3proto]) {
380
381 struct nf_conntrack_l4proto __rcu **proto_array;
382 int i;
383
384 proto_array = kmalloc(MAX_NF_CT_PROTO *
385 sizeof(struct nf_conntrack_l4proto *),
386 GFP_KERNEL);
387 if (proto_array == NULL) {
388 ret = -ENOMEM;
389 goto out_unlock;
390 }
391
392 for (i = 0; i < MAX_NF_CT_PROTO; i++)
393 RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic);
394
395
396
397
398 smp_wmb();
399
400 nf_ct_protos[l4proto->l3proto] = proto_array;
401 } else if (rcu_dereference_protected(
402 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
403 lockdep_is_held(&nf_ct_proto_mutex)
404 ) != &nf_conntrack_l4proto_generic) {
405 ret = -EBUSY;
406 goto out_unlock;
407 }
408
409 l4proto->nla_size = 0;
410 if (l4proto->nlattr_size)
411 l4proto->nla_size += l4proto->nlattr_size();
412 if (l4proto->nlattr_tuple_size)
413 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
414
415 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
416 l4proto);
417out_unlock:
418 mutex_unlock(&nf_ct_proto_mutex);
419 return ret;
420}
421EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
422
423int nf_ct_l4proto_pernet_register(struct net *net,
424 struct nf_conntrack_l4proto *l4proto)
425{
426 int ret = 0;
427 struct nf_proto_net *pn = NULL;
428
429 if (l4proto->init_net) {
430 ret = l4proto->init_net(net, l4proto->l3proto);
431 if (ret < 0)
432 goto out;
433 }
434
435 pn = nf_ct_l4proto_net(net, l4proto);
436 if (pn == NULL)
437 goto out;
438
439 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
440 if (ret < 0)
441 goto out;
442
443 pn->users++;
444out:
445 return ret;
446}
447EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
448
449void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
450{
451 BUG_ON(l4proto->l3proto >= PF_MAX);
452
453 mutex_lock(&nf_ct_proto_mutex);
454 BUG_ON(rcu_dereference_protected(
455 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
456 lockdep_is_held(&nf_ct_proto_mutex)
457 ) != l4proto);
458 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
459 &nf_conntrack_l4proto_generic);
460 mutex_unlock(&nf_ct_proto_mutex);
461
462 synchronize_rcu();
463}
464EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
465
466void nf_ct_l4proto_pernet_unregister(struct net *net,
467 struct nf_conntrack_l4proto *l4proto)
468{
469 struct nf_proto_net *pn = NULL;
470
471 pn = nf_ct_l4proto_net(net, l4proto);
472 if (pn == NULL)
473 return;
474
475 pn->users--;
476 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
477
478
479 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
480}
481EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
482
483int nf_conntrack_proto_pernet_init(struct net *net)
484{
485 int err;
486 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
487 &nf_conntrack_l4proto_generic);
488
489 err = nf_conntrack_l4proto_generic.init_net(net,
490 nf_conntrack_l4proto_generic.l3proto);
491 if (err < 0)
492 return err;
493 err = nf_ct_l4proto_register_sysctl(net,
494 pn,
495 &nf_conntrack_l4proto_generic);
496 if (err < 0)
497 return err;
498
499 pn->users++;
500 return 0;
501}
502
503void nf_conntrack_proto_pernet_fini(struct net *net)
504{
505 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
506 &nf_conntrack_l4proto_generic);
507
508 pn->users--;
509 nf_ct_l4proto_unregister_sysctl(net,
510 pn,
511 &nf_conntrack_l4proto_generic);
512}
513
514int nf_conntrack_proto_init(void)
515{
516 unsigned int i;
517 for (i = 0; i < AF_MAX; i++)
518 rcu_assign_pointer(nf_ct_l3protos[i],
519 &nf_conntrack_l3proto_generic);
520 return 0;
521}
522
523void nf_conntrack_proto_fini(void)
524{
525 unsigned int i;
526
527 for (i = 0; i < PF_MAX; i++)
528 kfree(nf_ct_protos[i]);
529}
530
