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12#include <linux/types.h>
13#include <linux/netfilter.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/mutex.h>
17#include <linux/vmalloc.h>
18#include <linux/stddef.h>
19#include <linux/err.h>
20#include <linux/percpu.h>
21#include <linux/notifier.h>
22#include <linux/kernel.h>
23#include <linux/netdevice.h>
24#include <linux/rtnetlink.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
216static int
217nf_conntrack_l3proto_register_net(struct nf_conntrack_l3proto *proto)
218{
219 int ret = 0;
220 struct nf_conntrack_l3proto *old;
221
222 if (proto->l3proto >= AF_MAX)
223 return -EBUSY;
224
225 if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
226 return -EINVAL;
227
228 mutex_lock(&nf_ct_proto_mutex);
229 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
230 lockdep_is_held(&nf_ct_proto_mutex));
231 if (old != &nf_conntrack_l3proto_generic) {
232 ret = -EBUSY;
233 goto out_unlock;
234 }
235
236 if (proto->nlattr_tuple_size)
237 proto->nla_size = 3 * proto->nlattr_tuple_size();
238
239 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
240
241out_unlock:
242 mutex_unlock(&nf_ct_proto_mutex);
243 return ret;
244
245}
246
247int nf_conntrack_l3proto_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 ret = nf_ct_l3proto_register_sysctl(net, proto);
259 if (ret < 0)
260 return ret;
261
262 if (net == &init_net) {
263 ret = nf_conntrack_l3proto_register_net(proto);
264 if (ret < 0)
265 nf_ct_l3proto_unregister_sysctl(net, proto);
266 }
267
268 return ret;
269}
270EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
271
272static void
273nf_conntrack_l3proto_unregister_net(struct nf_conntrack_l3proto *proto)
274{
275 BUG_ON(proto->l3proto >= AF_MAX);
276
277 mutex_lock(&nf_ct_proto_mutex);
278 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
279 lockdep_is_held(&nf_ct_proto_mutex)
280 ) != proto);
281 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
282 &nf_conntrack_l3proto_generic);
283 mutex_unlock(&nf_ct_proto_mutex);
284
285 synchronize_rcu();
286}
287
288void nf_conntrack_l3proto_unregister(struct net *net,
289 struct nf_conntrack_l3proto *proto)
290{
291 if (net == &init_net)
292 nf_conntrack_l3proto_unregister_net(proto);
293
294 nf_ct_l3proto_unregister_sysctl(net, proto);
295
296
297 rtnl_lock();
298 nf_ct_iterate_cleanup(net, kill_l3proto, proto);
299 rtnl_unlock();
300}
301EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
302
303static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
304 struct nf_conntrack_l4proto *l4proto)
305{
306 if (l4proto->get_net_proto) {
307
308 return l4proto->get_net_proto(net);
309 } else if (l4proto->net_id) {
310
311 return net_generic(net, *l4proto->net_id);
312 }
313 return NULL;
314}
315
316static
317int nf_ct_l4proto_register_sysctl(struct net *net,
318 struct nf_proto_net *pn,
319 struct nf_conntrack_l4proto *l4proto)
320{
321 int err = 0;
322
323#ifdef CONFIG_SYSCTL
324 if (pn->ctl_table != NULL) {
325 err = nf_ct_register_sysctl(net,
326 &pn->ctl_table_header,
327 "net/netfilter",
328 pn->ctl_table);
329 if (err < 0) {
330 if (!pn->users) {
331 kfree(pn->ctl_table);
332 pn->ctl_table = NULL;
333 }
334 }
335 }
336#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
337 if (l4proto->l3proto != AF_INET6 && pn->ctl_compat_table != NULL) {
338 if (err < 0) {
339 nf_ct_kfree_compat_sysctl_table(pn);
340 goto out;
341 }
342 err = nf_ct_register_sysctl(net,
343 &pn->ctl_compat_header,
344 "net/ipv4/netfilter",
345 pn->ctl_compat_table);
346 if (err == 0)
347 goto out;
348
349 nf_ct_kfree_compat_sysctl_table(pn);
350 nf_ct_unregister_sysctl(&pn->ctl_table_header,
351 &pn->ctl_table,
352 pn->users);
353 }
354out:
355#endif
356#endif
357 return err;
358}
359
360static
361void nf_ct_l4proto_unregister_sysctl(struct net *net,
362 struct nf_proto_net *pn,
363 struct nf_conntrack_l4proto *l4proto)
364{
365#ifdef CONFIG_SYSCTL
366 if (pn->ctl_table_header != NULL)
367 nf_ct_unregister_sysctl(&pn->ctl_table_header,
368 &pn->ctl_table,
369 pn->users);
370
371#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
372 if (l4proto->l3proto != AF_INET6 && pn->ctl_compat_header != NULL)
373 nf_ct_unregister_sysctl(&pn->ctl_compat_header,
374 &pn->ctl_compat_table,
375 0);
376#endif
377#endif
378}
379
380
381
382static int
383nf_conntrack_l4proto_register_net(struct nf_conntrack_l4proto *l4proto)
384{
385 int ret = 0;
386
387 if (l4proto->l3proto >= PF_MAX)
388 return -EBUSY;
389
390 if ((l4proto->to_nlattr && !l4proto->nlattr_size)
391 || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
392 return -EINVAL;
393
394 mutex_lock(&nf_ct_proto_mutex);
395 if (!nf_ct_protos[l4proto->l3proto]) {
396
397 struct nf_conntrack_l4proto __rcu **proto_array;
398 int i;
399
400 proto_array = kmalloc(MAX_NF_CT_PROTO *
401 sizeof(struct nf_conntrack_l4proto *),
402 GFP_KERNEL);
403 if (proto_array == NULL) {
404 ret = -ENOMEM;
405 goto out_unlock;
406 }
407
408 for (i = 0; i < MAX_NF_CT_PROTO; i++)
409 RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic);
410
411
412
413
414 smp_wmb();
415
416 nf_ct_protos[l4proto->l3proto] = proto_array;
417 } else if (rcu_dereference_protected(
418 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
419 lockdep_is_held(&nf_ct_proto_mutex)
420 ) != &nf_conntrack_l4proto_generic) {
421 ret = -EBUSY;
422 goto out_unlock;
423 }
424
425 l4proto->nla_size = 0;
426 if (l4proto->nlattr_size)
427 l4proto->nla_size += l4proto->nlattr_size();
428 if (l4proto->nlattr_tuple_size)
429 l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
430
431 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
432 l4proto);
433out_unlock:
434 mutex_unlock(&nf_ct_proto_mutex);
435 return ret;
436}
437
438int nf_conntrack_l4proto_register(struct net *net,
439 struct nf_conntrack_l4proto *l4proto)
440{
441 int ret = 0;
442 struct nf_proto_net *pn = NULL;
443
444 if (l4proto->init_net) {
445 ret = l4proto->init_net(net, l4proto->l3proto);
446 if (ret < 0)
447 goto out;
448 }
449
450 pn = nf_ct_l4proto_net(net, l4proto);
451 if (pn == NULL)
452 goto out;
453
454 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
455 if (ret < 0)
456 goto out;
457
458 if (net == &init_net) {
459 ret = nf_conntrack_l4proto_register_net(l4proto);
460 if (ret < 0) {
461 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
462 goto out;
463 }
464 }
465
466 pn->users++;
467out:
468 return ret;
469}
470EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
471
472static void
473nf_conntrack_l4proto_unregister_net(struct nf_conntrack_l4proto *l4proto)
474{
475 BUG_ON(l4proto->l3proto >= PF_MAX);
476
477 mutex_lock(&nf_ct_proto_mutex);
478 BUG_ON(rcu_dereference_protected(
479 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
480 lockdep_is_held(&nf_ct_proto_mutex)
481 ) != l4proto);
482 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
483 &nf_conntrack_l4proto_generic);
484 mutex_unlock(&nf_ct_proto_mutex);
485
486 synchronize_rcu();
487}
488
489void nf_conntrack_l4proto_unregister(struct net *net,
490 struct nf_conntrack_l4proto *l4proto)
491{
492 struct nf_proto_net *pn = NULL;
493
494 if (net == &init_net)
495 nf_conntrack_l4proto_unregister_net(l4proto);
496
497 pn = nf_ct_l4proto_net(net, l4proto);
498 if (pn == NULL)
499 return;
500
501 pn->users--;
502 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
503
504
505 rtnl_lock();
506 nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
507 rtnl_unlock();
508}
509EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
510
511int nf_conntrack_proto_init(struct net *net)
512{
513 unsigned int i;
514 int err;
515 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
516 &nf_conntrack_l4proto_generic);
517
518 err = nf_conntrack_l4proto_generic.init_net(net,
519 nf_conntrack_l4proto_generic.l3proto);
520 if (err < 0)
521 return err;
522 err = nf_ct_l4proto_register_sysctl(net,
523 pn,
524 &nf_conntrack_l4proto_generic);
525 if (err < 0)
526 return err;
527
528 if (net == &init_net) {
529 for (i = 0; i < AF_MAX; i++)
530 rcu_assign_pointer(nf_ct_l3protos[i],
531 &nf_conntrack_l3proto_generic);
532 }
533
534 pn->users++;
535 return 0;
536}
537
538void nf_conntrack_proto_fini(struct net *net)
539{
540 unsigned int i;
541 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
542 &nf_conntrack_l4proto_generic);
543
544 pn->users--;
545 nf_ct_l4proto_unregister_sysctl(net,
546 pn,
547 &nf_conntrack_l4proto_generic);
548 if (net == &init_net) {
549
550 for (i = 0; i < PF_MAX; i++)
551 kfree(nf_ct_protos[i]);
552 }
553}
554
