tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
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 (or any later at your option).
7 *
8 * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
9 */
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/skbuff.h>
14#include <linux/netlink.h>
15#include <linux/rculist.h>
16#include <linux/slab.h>
17#include <linux/types.h>
18#include <linux/list.h>
19#include <linux/errno.h>
20#include <net/netlink.h>
21#include <net/sock.h>
22
23#include <net/netfilter/nf_conntrack_helper.h>
24#include <net/netfilter/nf_conntrack_expect.h>
25#include <net/netfilter/nf_conntrack_ecache.h>
26
27#include <linux/netfilter/nfnetlink.h>
28#include <linux/netfilter/nfnetlink_conntrack.h>
29#include <linux/netfilter/nfnetlink_cthelper.h>
30
31MODULE_LICENSE("GPL");
32MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
33MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
34
35static int
36nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
37 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
38{
39 const struct nf_conn_help *help;
40 struct nf_conntrack_helper *helper;
41
42 help = nfct_help(ct);
43 if (help == NULL)
44 return NF_DROP;
45
46 /* rcu_read_lock()ed by nf_hook_slow */
47 helper = rcu_dereference(help->helper);
48 if (helper == NULL)
49 return NF_DROP;
50
51 /* This is an user-space helper not yet configured, skip. */
52 if ((helper->flags &
53 (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
54 NF_CT_HELPER_F_USERSPACE)
55 return NF_ACCEPT;
56
57 /* If the user-space helper is not available, don't block traffic. */
58 return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
59}
60
61static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
62 [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
63 [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
64};
65
66static int
67nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
68 const struct nlattr *attr)
69{
70 struct nlattr *tb[NFCTH_TUPLE_MAX+1];
71
72 nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol);
73
74 if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
75 return -EINVAL;
76
77 tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
78 tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
79
80 return 0;
81}
82
83static int
84nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
85{
86 const struct nf_conn_help *help = nfct_help(ct);
87
88 if (attr == NULL)
89 return -EINVAL;
90
91 if (help->helper->data_len == 0)
92 return -EINVAL;
93
94 memcpy(&help->data, nla_data(attr), help->helper->data_len);
95 return 0;
96}
97
98static int
99nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
100{
101 const struct nf_conn_help *help = nfct_help(ct);
102
103 if (help->helper->data_len &&
104 nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
105 goto nla_put_failure;
106
107 return 0;
108
109nla_put_failure:
110 return -ENOSPC;
111}
112
113static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
114 [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
115 .len = NF_CT_HELPER_NAME_LEN-1 },
116 [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
117 [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
118};
119
120static int
121nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
122 const struct nlattr *attr)
123{
124 struct nlattr *tb[NFCTH_POLICY_MAX+1];
125
126 nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol);
127
128 if (!tb[NFCTH_POLICY_NAME] ||
129 !tb[NFCTH_POLICY_EXPECT_MAX] ||
130 !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
131 return -EINVAL;
132
133 strncpy(expect_policy->name,
134 nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN);
135 expect_policy->max_expected =
136 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
137 expect_policy->timeout =
138 ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
139
140 return 0;
141}
142
143static const struct nla_policy
144nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
145 [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
146};
147
148static int
149nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
150 const struct nlattr *attr)
151{
152 int i, ret;
153 struct nf_conntrack_expect_policy *expect_policy;
154 struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
155
156 nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr,
157 nfnl_cthelper_expect_policy_set);
158
159 if (!tb[NFCTH_POLICY_SET_NUM])
160 return -EINVAL;
161
162 helper->expect_class_max =
163 ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
164
165 if (helper->expect_class_max != 0 &&
166 helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
167 return -EOVERFLOW;
168
169 expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
170 helper->expect_class_max, GFP_KERNEL);
171 if (expect_policy == NULL)
172 return -ENOMEM;
173
174 for (i=0; i<helper->expect_class_max; i++) {
175 if (!tb[NFCTH_POLICY_SET+i])
176 goto err;
177
178 ret = nfnl_cthelper_expect_policy(&expect_policy[i],
179 tb[NFCTH_POLICY_SET+i]);
180 if (ret < 0)
181 goto err;
182 }
183 helper->expect_policy = expect_policy;
184 return 0;
185err:
186 kfree(expect_policy);
187 return -EINVAL;
188}
189
190static int
191nfnl_cthelper_create(const struct nlattr * const tb[],
192 struct nf_conntrack_tuple *tuple)
193{
194 struct nf_conntrack_helper *helper;
195 int ret;
196
197 if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
198 return -EINVAL;
199
200 helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
201 if (helper == NULL)
202 return -ENOMEM;
203
204 ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
205 if (ret < 0)
206 goto err;
207
208 strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
209 helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
210 helper->flags |= NF_CT_HELPER_F_USERSPACE;
211 memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
212
213 helper->me = THIS_MODULE;
214 helper->help = nfnl_userspace_cthelper;
215 helper->from_nlattr = nfnl_cthelper_from_nlattr;
216 helper->to_nlattr = nfnl_cthelper_to_nlattr;
217
218 /* Default to queue number zero, this can be updated at any time. */
219 if (tb[NFCTH_QUEUE_NUM])
220 helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
221
222 if (tb[NFCTH_STATUS]) {
223 int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
224
225 switch(status) {
226 case NFCT_HELPER_STATUS_ENABLED:
227 helper->flags |= NF_CT_HELPER_F_CONFIGURED;
228 break;
229 case NFCT_HELPER_STATUS_DISABLED:
230 helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
231 break;
232 }
233 }
234
235 ret = nf_conntrack_helper_register(helper);
236 if (ret < 0)
237 goto err;
238
239 return 0;
240err:
241 kfree(helper);
242 return ret;
243}
244
245static int
246nfnl_cthelper_update(const struct nlattr * const tb[],
247 struct nf_conntrack_helper *helper)
248{
249 int ret;
250
251 if (tb[NFCTH_PRIV_DATA_LEN])
252 return -EBUSY;
253
254 if (tb[NFCTH_POLICY]) {
255 ret = nfnl_cthelper_parse_expect_policy(helper,
256 tb[NFCTH_POLICY]);
257 if (ret < 0)
258 return ret;
259 }
260 if (tb[NFCTH_QUEUE_NUM])
261 helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
262
263 if (tb[NFCTH_STATUS]) {
264 int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
265
266 switch(status) {
267 case NFCT_HELPER_STATUS_ENABLED:
268 helper->flags |= NF_CT_HELPER_F_CONFIGURED;
269 break;
270 case NFCT_HELPER_STATUS_DISABLED:
271 helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
272 break;
273 }
274 }
275 return 0;
276}
277
278static int
279nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb,
280 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
281{
282 const char *helper_name;
283 struct nf_conntrack_helper *cur, *helper = NULL;
284 struct nf_conntrack_tuple tuple;
285 int ret = 0, i;
286
287 if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
288 return -EINVAL;
289
290 helper_name = nla_data(tb[NFCTH_NAME]);
291
292 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
293 if (ret < 0)
294 return ret;
295
296 rcu_read_lock();
297 for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
298 hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
299
300 /* skip non-userspace conntrack helpers. */
301 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
302 continue;
303
304 if (strncmp(cur->name, helper_name,
305 NF_CT_HELPER_NAME_LEN) != 0)
306 continue;
307
308 if ((tuple.src.l3num != cur->tuple.src.l3num ||
309 tuple.dst.protonum != cur->tuple.dst.protonum))
310 continue;
311
312 if (nlh->nlmsg_flags & NLM_F_EXCL) {
313 ret = -EEXIST;
314 goto err;
315 }
316 helper = cur;
317 break;
318 }
319 }
320 rcu_read_unlock();
321
322 if (helper == NULL)
323 ret = nfnl_cthelper_create(tb, &tuple);
324 else
325 ret = nfnl_cthelper_update(tb, helper);
326
327 return ret;
328err:
329 rcu_read_unlock();
330 return ret;
331}
332
333static int
334nfnl_cthelper_dump_tuple(struct sk_buff *skb,
335 struct nf_conntrack_helper *helper)
336{
337 struct nlattr *nest_parms;
338
339 nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED);
340 if (nest_parms == NULL)
341 goto nla_put_failure;
342
343 if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
344 htons(helper->tuple.src.l3num)))
345 goto nla_put_failure;
346
347 if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
348 goto nla_put_failure;
349
350 nla_nest_end(skb, nest_parms);
351 return 0;
352
353nla_put_failure:
354 return -1;
355}
356
357static int
358nfnl_cthelper_dump_policy(struct sk_buff *skb,
359 struct nf_conntrack_helper *helper)
360{
361 int i;
362 struct nlattr *nest_parms1, *nest_parms2;
363
364 nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED);
365 if (nest_parms1 == NULL)
366 goto nla_put_failure;
367
368 if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
369 htonl(helper->expect_class_max)))
370 goto nla_put_failure;
371
372 for (i=0; i<helper->expect_class_max; i++) {
373 nest_parms2 = nla_nest_start(skb,
374 (NFCTH_POLICY_SET+i) | NLA_F_NESTED);
375 if (nest_parms2 == NULL)
376 goto nla_put_failure;
377
378 if (nla_put_string(skb, NFCTH_POLICY_NAME,
379 helper->expect_policy[i].name))
380 goto nla_put_failure;
381
382 if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
383 htonl(helper->expect_policy[i].max_expected)))
384 goto nla_put_failure;
385
386 if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
387 htonl(helper->expect_policy[i].timeout)))
388 goto nla_put_failure;
389
390 nla_nest_end(skb, nest_parms2);
391 }
392 nla_nest_end(skb, nest_parms1);
393 return 0;
394
395nla_put_failure:
396 return -1;
397}
398
399static int
400nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
401 int event, struct nf_conntrack_helper *helper)
402{
403 struct nlmsghdr *nlh;
404 struct nfgenmsg *nfmsg;
405 unsigned int flags = portid ? NLM_F_MULTI : 0;
406 int status;
407
408 event |= NFNL_SUBSYS_CTHELPER << 8;
409 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
410 if (nlh == NULL)
411 goto nlmsg_failure;
412
413 nfmsg = nlmsg_data(nlh);
414 nfmsg->nfgen_family = AF_UNSPEC;
415 nfmsg->version = NFNETLINK_V0;
416 nfmsg->res_id = 0;
417
418 if (nla_put_string(skb, NFCTH_NAME, helper->name))
419 goto nla_put_failure;
420
421 if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
422 goto nla_put_failure;
423
424 if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
425 goto nla_put_failure;
426
427 if (nfnl_cthelper_dump_policy(skb, helper) < 0)
428 goto nla_put_failure;
429
430 if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
431 goto nla_put_failure;
432
433 if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
434 status = NFCT_HELPER_STATUS_ENABLED;
435 else
436 status = NFCT_HELPER_STATUS_DISABLED;
437
438 if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
439 goto nla_put_failure;
440
441 nlmsg_end(skb, nlh);
442 return skb->len;
443
444nlmsg_failure:
445nla_put_failure:
446 nlmsg_cancel(skb, nlh);
447 return -1;
448}
449
450static int
451nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
452{
453 struct nf_conntrack_helper *cur, *last;
454
455 rcu_read_lock();
456 last = (struct nf_conntrack_helper *)cb->args[1];
457 for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
458restart:
459 hlist_for_each_entry_rcu(cur,
460 &nf_ct_helper_hash[cb->args[0]], hnode) {
461
462 /* skip non-userspace conntrack helpers. */
463 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
464 continue;
465
466 if (cb->args[1]) {
467 if (cur != last)
468 continue;
469 cb->args[1] = 0;
470 }
471 if (nfnl_cthelper_fill_info(skb,
472 NETLINK_CB(cb->skb).portid,
473 cb->nlh->nlmsg_seq,
474 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
475 NFNL_MSG_CTHELPER_NEW, cur) < 0) {
476 cb->args[1] = (unsigned long)cur;
477 goto out;
478 }
479 }
480 }
481 if (cb->args[1]) {
482 cb->args[1] = 0;
483 goto restart;
484 }
485out:
486 rcu_read_unlock();
487 return skb->len;
488}
489
490static int
491nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb,
492 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
493{
494 int ret = -ENOENT, i;
495 struct nf_conntrack_helper *cur;
496 struct sk_buff *skb2;
497 char *helper_name = NULL;
498 struct nf_conntrack_tuple tuple;
499 bool tuple_set = false;
500
501 if (nlh->nlmsg_flags & NLM_F_DUMP) {
502 struct netlink_dump_control c = {
503 .dump = nfnl_cthelper_dump_table,
504 };
505 return netlink_dump_start(nfnl, skb, nlh, &c);
506 }
507
508 if (tb[NFCTH_NAME])
509 helper_name = nla_data(tb[NFCTH_NAME]);
510
511 if (tb[NFCTH_TUPLE]) {
512 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
513 if (ret < 0)
514 return ret;
515
516 tuple_set = true;
517 }
518
519 for (i = 0; i < nf_ct_helper_hsize; i++) {
520 hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
521
522 /* skip non-userspace conntrack helpers. */
523 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
524 continue;
525
526 if (helper_name && strncmp(cur->name, helper_name,
527 NF_CT_HELPER_NAME_LEN) != 0) {
528 continue;
529 }
530 if (tuple_set &&
531 (tuple.src.l3num != cur->tuple.src.l3num ||
532 tuple.dst.protonum != cur->tuple.dst.protonum))
533 continue;
534
535 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
536 if (skb2 == NULL) {
537 ret = -ENOMEM;
538 break;
539 }
540
541 ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid,
542 nlh->nlmsg_seq,
543 NFNL_MSG_TYPE(nlh->nlmsg_type),
544 NFNL_MSG_CTHELPER_NEW, cur);
545 if (ret <= 0) {
546 kfree_skb(skb2);
547 break;
548 }
549
550 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
551 MSG_DONTWAIT);
552 if (ret > 0)
553 ret = 0;
554
555 /* this avoids a loop in nfnetlink. */
556 return ret == -EAGAIN ? -ENOBUFS : ret;
557 }
558 }
559 return ret;
560}
561
562static int
563nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb,
564 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
565{
566 char *helper_name = NULL;
567 struct nf_conntrack_helper *cur;
568 struct hlist_node *tmp;
569 struct nf_conntrack_tuple tuple;
570 bool tuple_set = false, found = false;
571 int i, j = 0, ret;
572
573 if (tb[NFCTH_NAME])
574 helper_name = nla_data(tb[NFCTH_NAME]);
575
576 if (tb[NFCTH_TUPLE]) {
577 ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
578 if (ret < 0)
579 return ret;
580
581 tuple_set = true;
582 }
583
584 for (i = 0; i < nf_ct_helper_hsize; i++) {
585 hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
586 hnode) {
587 /* skip non-userspace conntrack helpers. */
588 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
589 continue;
590
591 j++;
592
593 if (helper_name && strncmp(cur->name, helper_name,
594 NF_CT_HELPER_NAME_LEN) != 0) {
595 continue;
596 }
597 if (tuple_set &&
598 (tuple.src.l3num != cur->tuple.src.l3num ||
599 tuple.dst.protonum != cur->tuple.dst.protonum))
600 continue;
601
602 found = true;
603 nf_conntrack_helper_unregister(cur);
604 }
605 }
606 /* Make sure we return success if we flush and there is no helpers */
607 return (found || j == 0) ? 0 : -ENOENT;
608}
609
610static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
611 [NFCTH_NAME] = { .type = NLA_NUL_STRING,
612 .len = NF_CT_HELPER_NAME_LEN-1 },
613 [NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
614};
615
616static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
617 [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
618 .attr_count = NFCTH_MAX,
619 .policy = nfnl_cthelper_policy },
620 [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
621 .attr_count = NFCTH_MAX,
622 .policy = nfnl_cthelper_policy },
623 [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
624 .attr_count = NFCTH_MAX,
625 .policy = nfnl_cthelper_policy },
626};
627
628static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
629 .name = "cthelper",
630 .subsys_id = NFNL_SUBSYS_CTHELPER,
631 .cb_count = NFNL_MSG_CTHELPER_MAX,
632 .cb = nfnl_cthelper_cb,
633};
634
635MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
636
637static int __init nfnl_cthelper_init(void)
638{
639 int ret;
640
641 ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
642 if (ret < 0) {
643 pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
644 goto err_out;
645 }
646 return 0;
647err_out:
648 return ret;
649}
650
651static void __exit nfnl_cthelper_exit(void)
652{
653 struct nf_conntrack_helper *cur;
654 struct hlist_node *tmp;
655 int i;
656
657 nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
658
659 for (i=0; i<nf_ct_helper_hsize; i++) {
660 hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
661 hnode) {
662 /* skip non-userspace conntrack helpers. */
663 if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
664 continue;
665
666 nf_conntrack_helper_unregister(cur);
667 }
668 }
669}
670
671module_init(nfnl_cthelper_init);
672module_exit(nfnl_cthelper_exit);