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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#include <net/netfilter/nf_log.h>
31
32static struct nf_conntrack_l4proto __rcu **nf_ct_protos[NFPROTO_NUMPROTO] __read_mostly;
33struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO] __read_mostly;
34EXPORT_SYMBOL_GPL(nf_ct_l3protos);
35
36static DEFINE_MUTEX(nf_ct_proto_mutex);
37
38#ifdef CONFIG_SYSCTL
39static int
40nf_ct_register_sysctl(struct net *net,
41 struct ctl_table_header **header,
42 const char *path,
43 struct ctl_table *table)
44{
45 if (*header == NULL) {
46 *header = register_net_sysctl(net, path, table);
47 if (*header == NULL)
48 return -ENOMEM;
49 }
50
51 return 0;
52}
53
54static void
55nf_ct_unregister_sysctl(struct ctl_table_header **header,
56 struct ctl_table **table,
57 unsigned int users)
58{
59 if (users > 0)
60 return;
61
62 unregister_net_sysctl_table(*header);
63 kfree(*table);
64 *header = NULL;
65 *table = NULL;
66}
67
68__printf(5, 6)
69void nf_l4proto_log_invalid(const struct sk_buff *skb,
70 struct net *net,
71 u16 pf, u8 protonum,
72 const char *fmt, ...)
73{
74 struct va_format vaf;
75 va_list args;
76
77 if (net->ct.sysctl_log_invalid != protonum &&
78 net->ct.sysctl_log_invalid != IPPROTO_RAW)
79 return;
80
81 va_start(args, fmt);
82 vaf.fmt = fmt;
83 vaf.va = &args;
84
85 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
86 "nf_ct_proto_%d: %pV ", protonum, &vaf);
87 va_end(args);
88}
89EXPORT_SYMBOL_GPL(nf_l4proto_log_invalid);
90
91__printf(3, 4)
92void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
93 const struct nf_conn *ct,
94 const char *fmt, ...)
95{
96 struct va_format vaf;
97 struct net *net;
98 va_list args;
99
100 net = nf_ct_net(ct);
101 if (likely(net->ct.sysctl_log_invalid == 0))
102 return;
103
104 va_start(args, fmt);
105 vaf.fmt = fmt;
106 vaf.va = &args;
107
108 nf_l4proto_log_invalid(skb, net, nf_ct_l3num(ct),
109 nf_ct_protonum(ct), "%pV", &vaf);
110 va_end(args);
111}
112EXPORT_SYMBOL_GPL(nf_ct_l4proto_log_invalid);
113#endif
114
115const struct nf_conntrack_l4proto *
116__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
117{
118 if (unlikely(l3proto >= NFPROTO_NUMPROTO || nf_ct_protos[l3proto] == NULL))
119 return &nf_conntrack_l4proto_generic;
120
121 return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
122}
123EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
124
125
126
127const struct nf_conntrack_l3proto *
128nf_ct_l3proto_find_get(u_int16_t l3proto)
129{
130 struct nf_conntrack_l3proto *p;
131
132 rcu_read_lock();
133 p = __nf_ct_l3proto_find(l3proto);
134 if (!try_module_get(p->me))
135 p = &nf_conntrack_l3proto_generic;
136 rcu_read_unlock();
137
138 return p;
139}
140EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
141
142int
143nf_ct_l3proto_try_module_get(unsigned short l3proto)
144{
145 const struct nf_conntrack_l3proto *p;
146 int ret;
147
148retry: p = nf_ct_l3proto_find_get(l3proto);
149 if (p == &nf_conntrack_l3proto_generic) {
150 ret = request_module("nf_conntrack-%d", l3proto);
151 if (!ret)
152 goto retry;
153
154 return -EPROTOTYPE;
155 }
156
157 return 0;
158}
159EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
160
161void nf_ct_l3proto_module_put(unsigned short l3proto)
162{
163 struct nf_conntrack_l3proto *p;
164
165
166
167
168 rcu_read_lock();
169 p = __nf_ct_l3proto_find(l3proto);
170 module_put(p->me);
171 rcu_read_unlock();
172}
173EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
174
175static int nf_ct_netns_do_get(struct net *net, u8 nfproto)
176{
177 const struct nf_conntrack_l3proto *l3proto;
178 int ret;
179
180 might_sleep();
181
182 ret = nf_ct_l3proto_try_module_get(nfproto);
183 if (ret < 0)
184 return ret;
185
186
187 rcu_read_lock();
188 l3proto = __nf_ct_l3proto_find(nfproto);
189 rcu_read_unlock();
190
191 if (!l3proto->net_ns_get)
192 return 0;
193
194 ret = l3proto->net_ns_get(net);
195 if (ret < 0)
196 nf_ct_l3proto_module_put(nfproto);
197
198 return ret;
199}
200
201int nf_ct_netns_get(struct net *net, u8 nfproto)
202{
203 int err;
204
205 if (nfproto == NFPROTO_INET) {
206 err = nf_ct_netns_do_get(net, NFPROTO_IPV4);
207 if (err < 0)
208 goto err1;
209 err = nf_ct_netns_do_get(net, NFPROTO_IPV6);
210 if (err < 0)
211 goto err2;
212 } else {
213 err = nf_ct_netns_do_get(net, nfproto);
214 if (err < 0)
215 goto err1;
216 }
217 return 0;
218
219err2:
220 nf_ct_netns_put(net, NFPROTO_IPV4);
221err1:
222 return err;
223}
224EXPORT_SYMBOL_GPL(nf_ct_netns_get);
225
226static void nf_ct_netns_do_put(struct net *net, u8 nfproto)
227{
228 const struct nf_conntrack_l3proto *l3proto;
229
230 might_sleep();
231
232
233 rcu_read_lock();
234 l3proto = __nf_ct_l3proto_find(nfproto);
235 rcu_read_unlock();
236
237 if (WARN_ON(!l3proto))
238 return;
239
240 if (l3proto->net_ns_put)
241 l3proto->net_ns_put(net);
242
243 nf_ct_l3proto_module_put(nfproto);
244}
245
246void nf_ct_netns_put(struct net *net, uint8_t nfproto)
247{
248 if (nfproto == NFPROTO_INET) {
249 nf_ct_netns_do_put(net, NFPROTO_IPV4);
250 nf_ct_netns_do_put(net, NFPROTO_IPV6);
251 } else
252 nf_ct_netns_do_put(net, nfproto);
253}
254EXPORT_SYMBOL_GPL(nf_ct_netns_put);
255
256const struct nf_conntrack_l4proto *
257nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
258{
259 const struct nf_conntrack_l4proto *p;
260
261 rcu_read_lock();
262 p = __nf_ct_l4proto_find(l3num, l4num);
263 if (!try_module_get(p->me))
264 p = &nf_conntrack_l4proto_generic;
265 rcu_read_unlock();
266
267 return p;
268}
269EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
270
271void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p)
272{
273 module_put(p->me);
274}
275EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
276
277static int kill_l3proto(struct nf_conn *i, void *data)
278{
279 return nf_ct_l3num(i) == ((const struct nf_conntrack_l3proto *)data)->l3proto;
280}
281
282static int kill_l4proto(struct nf_conn *i, void *data)
283{
284 const struct nf_conntrack_l4proto *l4proto;
285 l4proto = data;
286 return nf_ct_protonum(i) == l4proto->l4proto &&
287 nf_ct_l3num(i) == l4proto->l3proto;
288}
289
290int nf_ct_l3proto_register(const struct nf_conntrack_l3proto *proto)
291{
292 int ret = 0;
293 struct nf_conntrack_l3proto *old;
294
295 if (proto->l3proto >= NFPROTO_NUMPROTO)
296 return -EBUSY;
297#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
298 if (proto->tuple_to_nlattr && proto->nla_size == 0)
299 return -EINVAL;
300#endif
301 mutex_lock(&nf_ct_proto_mutex);
302 old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
303 lockdep_is_held(&nf_ct_proto_mutex));
304 if (old != &nf_conntrack_l3proto_generic) {
305 ret = -EBUSY;
306 goto out_unlock;
307 }
308
309 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
310
311out_unlock:
312 mutex_unlock(&nf_ct_proto_mutex);
313 return ret;
314
315}
316EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
317
318void nf_ct_l3proto_unregister(const struct nf_conntrack_l3proto *proto)
319{
320 BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);
321
322 mutex_lock(&nf_ct_proto_mutex);
323 BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
324 lockdep_is_held(&nf_ct_proto_mutex)
325 ) != proto);
326 rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
327 &nf_conntrack_l3proto_generic);
328 mutex_unlock(&nf_ct_proto_mutex);
329
330 synchronize_rcu();
331
332 nf_ct_iterate_destroy(kill_l3proto, (void*)proto);
333}
334EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
335
336static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
337 const struct nf_conntrack_l4proto *l4proto)
338{
339 if (l4proto->get_net_proto) {
340
341 return l4proto->get_net_proto(net);
342 } else if (l4proto->net_id) {
343
344 return net_generic(net, *l4proto->net_id);
345 }
346 return NULL;
347}
348
349static
350int nf_ct_l4proto_register_sysctl(struct net *net,
351 struct nf_proto_net *pn,
352 const struct nf_conntrack_l4proto *l4proto)
353{
354 int err = 0;
355
356#ifdef CONFIG_SYSCTL
357 if (pn->ctl_table != NULL) {
358 err = nf_ct_register_sysctl(net,
359 &pn->ctl_table_header,
360 "net/netfilter",
361 pn->ctl_table);
362 if (err < 0) {
363 if (!pn->users) {
364 kfree(pn->ctl_table);
365 pn->ctl_table = NULL;
366 }
367 }
368 }
369#endif
370 return err;
371}
372
373static
374void nf_ct_l4proto_unregister_sysctl(struct net *net,
375 struct nf_proto_net *pn,
376 const struct nf_conntrack_l4proto *l4proto)
377{
378#ifdef CONFIG_SYSCTL
379 if (pn->ctl_table_header != NULL)
380 nf_ct_unregister_sysctl(&pn->ctl_table_header,
381 &pn->ctl_table,
382 pn->users);
383#endif
384}
385
386
387
388int nf_ct_l4proto_register_one(const struct nf_conntrack_l4proto *l4proto)
389{
390 int ret = 0;
391
392 if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
393 return -EBUSY;
394
395 if ((l4proto->to_nlattr && l4proto->nlattr_size == 0) ||
396 (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
397 return -EINVAL;
398
399 mutex_lock(&nf_ct_proto_mutex);
400 if (!nf_ct_protos[l4proto->l3proto]) {
401
402 struct nf_conntrack_l4proto __rcu **proto_array;
403 int i;
404
405 proto_array =
406 kmalloc_array(MAX_NF_CT_PROTO,
407 sizeof(struct nf_conntrack_l4proto *),
408 GFP_KERNEL);
409 if (proto_array == NULL) {
410 ret = -ENOMEM;
411 goto out_unlock;
412 }
413
414 for (i = 0; i < MAX_NF_CT_PROTO; i++)
415 RCU_INIT_POINTER(proto_array[i],
416 &nf_conntrack_l4proto_generic);
417
418
419
420
421 smp_wmb();
422
423 nf_ct_protos[l4proto->l3proto] = proto_array;
424 } else if (rcu_dereference_protected(
425 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
426 lockdep_is_held(&nf_ct_proto_mutex)
427 ) != &nf_conntrack_l4proto_generic) {
428 ret = -EBUSY;
429 goto out_unlock;
430 }
431
432 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
433 l4proto);
434out_unlock:
435 mutex_unlock(&nf_ct_proto_mutex);
436 return ret;
437}
438EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
439
440int nf_ct_l4proto_pernet_register_one(struct net *net,
441 const struct nf_conntrack_l4proto *l4proto)
442{
443 int ret = 0;
444 struct nf_proto_net *pn = NULL;
445
446 if (l4proto->init_net) {
447 ret = l4proto->init_net(net, l4proto->l3proto);
448 if (ret < 0)
449 goto out;
450 }
451
452 pn = nf_ct_l4proto_net(net, l4proto);
453 if (pn == NULL)
454 goto out;
455
456 ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
457 if (ret < 0)
458 goto out;
459
460 pn->users++;
461out:
462 return ret;
463}
464EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
465
466static void __nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
467
468{
469 BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
470
471 BUG_ON(rcu_dereference_protected(
472 nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
473 lockdep_is_held(&nf_ct_proto_mutex)
474 ) != l4proto);
475 rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
476 &nf_conntrack_l4proto_generic);
477}
478
479void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
480{
481 mutex_lock(&nf_ct_proto_mutex);
482 __nf_ct_l4proto_unregister_one(l4proto);
483 mutex_unlock(&nf_ct_proto_mutex);
484
485 synchronize_net();
486
487 nf_ct_iterate_destroy(kill_l4proto, (void *)l4proto);
488}
489EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
490
491void nf_ct_l4proto_pernet_unregister_one(struct net *net,
492 const struct nf_conntrack_l4proto *l4proto)
493{
494 struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
495
496 if (pn == NULL)
497 return;
498
499 pn->users--;
500 nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
501}
502EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);
503
504int nf_ct_l4proto_register(const struct nf_conntrack_l4proto * const l4proto[],
505 unsigned int num_proto)
506{
507 int ret = -EINVAL, ver;
508 unsigned int i;
509
510 for (i = 0; i < num_proto; i++) {
511 ret = nf_ct_l4proto_register_one(l4proto[i]);
512 if (ret < 0)
513 break;
514 }
515 if (i != num_proto) {
516 ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
517 pr_err("nf_conntrack_ipv%d: can't register l4 %d proto.\n",
518 ver, l4proto[i]->l4proto);
519 nf_ct_l4proto_unregister(l4proto, i);
520 }
521 return ret;
522}
523EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
524
525int nf_ct_l4proto_pernet_register(struct net *net,
526 const struct nf_conntrack_l4proto *const l4proto[],
527 unsigned int num_proto)
528{
529 int ret = -EINVAL;
530 unsigned int i;
531
532 for (i = 0; i < num_proto; i++) {
533 ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
534 if (ret < 0)
535 break;
536 }
537 if (i != num_proto) {
538 pr_err("nf_conntrack_proto_%d %d: pernet registration failed\n",
539 l4proto[i]->l4proto,
540 l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
541 nf_ct_l4proto_pernet_unregister(net, l4proto, i);
542 }
543 return ret;
544}
545EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
546
547void nf_ct_l4proto_unregister(const struct nf_conntrack_l4proto * const l4proto[],
548 unsigned int num_proto)
549{
550 int i;
551
552 mutex_lock(&nf_ct_proto_mutex);
553 for (i = 0; i < num_proto; i++)
554 __nf_ct_l4proto_unregister_one(l4proto[i]);
555 mutex_unlock(&nf_ct_proto_mutex);
556
557 synchronize_net();
558
559 for (i = 0; i < num_proto; i++)
560 nf_ct_iterate_destroy(kill_l4proto, (void *)l4proto[i]);
561}
562EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
563
564void nf_ct_l4proto_pernet_unregister(struct net *net,
565 const struct nf_conntrack_l4proto *const l4proto[],
566 unsigned int num_proto)
567{
568 while (num_proto-- != 0)
569 nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
570}
571EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
572
573int nf_conntrack_proto_pernet_init(struct net *net)
574{
575 int err;
576 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
577 &nf_conntrack_l4proto_generic);
578
579 err = nf_conntrack_l4proto_generic.init_net(net,
580 nf_conntrack_l4proto_generic.l3proto);
581 if (err < 0)
582 return err;
583 err = nf_ct_l4proto_register_sysctl(net,
584 pn,
585 &nf_conntrack_l4proto_generic);
586 if (err < 0)
587 return err;
588
589 pn->users++;
590 return 0;
591}
592
593void nf_conntrack_proto_pernet_fini(struct net *net)
594{
595 struct nf_proto_net *pn = nf_ct_l4proto_net(net,
596 &nf_conntrack_l4proto_generic);
597
598 pn->users--;
599 nf_ct_l4proto_unregister_sysctl(net,
600 pn,
601 &nf_conntrack_l4proto_generic);
602}
603
604int nf_conntrack_proto_init(void)
605{
606 unsigned int i;
607 for (i = 0; i < NFPROTO_NUMPROTO; i++)
608 rcu_assign_pointer(nf_ct_l3protos[i],
609 &nf_conntrack_l3proto_generic);
610 return 0;
611}
612
613void nf_conntrack_proto_fini(void)
614{
615 unsigned int i;
616
617 for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
618 kfree(nf_ct_protos[i]);
619}
620
