Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation (or any later at your option).
8 */
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/rculist.h>
13#include <linux/rculist_nulls.h>
14#include <linux/types.h>
15#include <linux/timer.h>
16#include <linux/security.h>
17#include <linux/skbuff.h>
18#include <linux/errno.h>
19#include <linux/netlink.h>
20#include <linux/spinlock.h>
21#include <linux/interrupt.h>
22#include <linux/slab.h>
23
24#include <linux/netfilter.h>
25#include <net/netlink.h>
26#include <net/sock.h>
27#include <net/netfilter/nf_conntrack.h>
28#include <net/netfilter/nf_conntrack_core.h>
29#include <net/netfilter/nf_conntrack_l3proto.h>
30#include <net/netfilter/nf_conntrack_l4proto.h>
31#include <net/netfilter/nf_conntrack_tuple.h>
32#include <net/netfilter/nf_conntrack_timeout.h>
33
34#include <linux/netfilter/nfnetlink.h>
35#include <linux/netfilter/nfnetlink_cttimeout.h>
36
37MODULE_LICENSE("GPL");
38MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
39MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
40
41static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
42 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
43 .len = CTNL_TIMEOUT_NAME_MAX - 1},
44 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
45 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
46 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
47};
48
49static int
50ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
51 struct net *net, const struct nlattr *attr)
52{
53 int ret = 0;
54
55 if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
56 struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
57
58 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
59 attr, l4proto->ctnl_timeout.nla_policy);
60 if (ret < 0)
61 return ret;
62
63 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
64 }
65 return ret;
66}
67
68static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
69 struct sk_buff *skb,
70 const struct nlmsghdr *nlh,
71 const struct nlattr * const cda[])
72{
73 __u16 l3num;
74 __u8 l4num;
75 struct nf_conntrack_l4proto *l4proto;
76 struct ctnl_timeout *timeout, *matching = NULL;
77 char *name;
78 int ret;
79
80 if (!cda[CTA_TIMEOUT_NAME] ||
81 !cda[CTA_TIMEOUT_L3PROTO] ||
82 !cda[CTA_TIMEOUT_L4PROTO] ||
83 !cda[CTA_TIMEOUT_DATA])
84 return -EINVAL;
85
86 name = nla_data(cda[CTA_TIMEOUT_NAME]);
87 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
88 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
89
90 list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
91 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
92 continue;
93
94 if (nlh->nlmsg_flags & NLM_F_EXCL)
95 return -EEXIST;
96
97 matching = timeout;
98 break;
99 }
100
101 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
102
103 /* This protocol is not supportted, skip. */
104 if (l4proto->l4proto != l4num) {
105 ret = -EOPNOTSUPP;
106 goto err_proto_put;
107 }
108
109 if (matching) {
110 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
111 /* You cannot replace one timeout policy by another of
112 * different kind, sorry.
113 */
114 if (matching->l3num != l3num ||
115 matching->l4proto->l4proto != l4num) {
116 ret = -EINVAL;
117 goto err_proto_put;
118 }
119
120 ret = ctnl_timeout_parse_policy(&matching->data,
121 l4proto, net,
122 cda[CTA_TIMEOUT_DATA]);
123 return ret;
124 }
125 ret = -EBUSY;
126 goto err_proto_put;
127 }
128
129 timeout = kzalloc(sizeof(struct ctnl_timeout) +
130 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
131 if (timeout == NULL) {
132 ret = -ENOMEM;
133 goto err_proto_put;
134 }
135
136 ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
137 cda[CTA_TIMEOUT_DATA]);
138 if (ret < 0)
139 goto err;
140
141 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
142 timeout->l3num = l3num;
143 timeout->l4proto = l4proto;
144 atomic_set(&timeout->refcnt, 1);
145 list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
146
147 return 0;
148err:
149 kfree(timeout);
150err_proto_put:
151 nf_ct_l4proto_put(l4proto);
152 return ret;
153}
154
155static int
156ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
157 int event, struct ctnl_timeout *timeout)
158{
159 struct nlmsghdr *nlh;
160 struct nfgenmsg *nfmsg;
161 unsigned int flags = portid ? NLM_F_MULTI : 0;
162 struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
163
164 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
165 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
166 if (nlh == NULL)
167 goto nlmsg_failure;
168
169 nfmsg = nlmsg_data(nlh);
170 nfmsg->nfgen_family = AF_UNSPEC;
171 nfmsg->version = NFNETLINK_V0;
172 nfmsg->res_id = 0;
173
174 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
175 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
176 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
177 nla_put_be32(skb, CTA_TIMEOUT_USE,
178 htonl(atomic_read(&timeout->refcnt))))
179 goto nla_put_failure;
180
181 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
182 struct nlattr *nest_parms;
183 int ret;
184
185 nest_parms = nla_nest_start(skb,
186 CTA_TIMEOUT_DATA | NLA_F_NESTED);
187 if (!nest_parms)
188 goto nla_put_failure;
189
190 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
191 if (ret < 0)
192 goto nla_put_failure;
193
194 nla_nest_end(skb, nest_parms);
195 }
196
197 nlmsg_end(skb, nlh);
198 return skb->len;
199
200nlmsg_failure:
201nla_put_failure:
202 nlmsg_cancel(skb, nlh);
203 return -1;
204}
205
206static int
207ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
208{
209 struct net *net = sock_net(skb->sk);
210 struct ctnl_timeout *cur, *last;
211
212 if (cb->args[2])
213 return 0;
214
215 last = (struct ctnl_timeout *)cb->args[1];
216 if (cb->args[1])
217 cb->args[1] = 0;
218
219 rcu_read_lock();
220 list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
221 if (last) {
222 if (cur != last)
223 continue;
224
225 last = NULL;
226 }
227 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
228 cb->nlh->nlmsg_seq,
229 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
230 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
231 cb->args[1] = (unsigned long)cur;
232 break;
233 }
234 }
235 if (!cb->args[1])
236 cb->args[2] = 1;
237 rcu_read_unlock();
238 return skb->len;
239}
240
241static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
242 struct sk_buff *skb,
243 const struct nlmsghdr *nlh,
244 const struct nlattr * const cda[])
245{
246 int ret = -ENOENT;
247 char *name;
248 struct ctnl_timeout *cur;
249
250 if (nlh->nlmsg_flags & NLM_F_DUMP) {
251 struct netlink_dump_control c = {
252 .dump = ctnl_timeout_dump,
253 };
254 return netlink_dump_start(ctnl, skb, nlh, &c);
255 }
256
257 if (!cda[CTA_TIMEOUT_NAME])
258 return -EINVAL;
259 name = nla_data(cda[CTA_TIMEOUT_NAME]);
260
261 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
262 struct sk_buff *skb2;
263
264 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
265 continue;
266
267 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
268 if (skb2 == NULL) {
269 ret = -ENOMEM;
270 break;
271 }
272
273 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
274 nlh->nlmsg_seq,
275 NFNL_MSG_TYPE(nlh->nlmsg_type),
276 IPCTNL_MSG_TIMEOUT_NEW, cur);
277 if (ret <= 0) {
278 kfree_skb(skb2);
279 break;
280 }
281 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
282 MSG_DONTWAIT);
283 if (ret > 0)
284 ret = 0;
285
286 /* this avoids a loop in nfnetlink. */
287 return ret == -EAGAIN ? -ENOBUFS : ret;
288 }
289 return ret;
290}
291
292static void untimeout(struct nf_conntrack_tuple_hash *i,
293 struct ctnl_timeout *timeout)
294{
295 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
296 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
297
298 if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
299 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
300}
301
302static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
303{
304 struct nf_conntrack_tuple_hash *h;
305 const struct hlist_nulls_node *nn;
306 unsigned int last_hsize;
307 spinlock_t *lock;
308 int i;
309
310 local_bh_disable();
311restart:
312 last_hsize = nf_conntrack_htable_size;
313 for (i = 0; i < last_hsize; i++) {
314 lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
315 nf_conntrack_lock(lock);
316 if (last_hsize != nf_conntrack_htable_size) {
317 spin_unlock(lock);
318 goto restart;
319 }
320
321 hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
322 untimeout(h, timeout);
323 spin_unlock(lock);
324 }
325 local_bh_enable();
326}
327
328/* try to delete object, fail if it is still in use. */
329static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
330{
331 int ret = 0;
332
333 /* We want to avoid races with ctnl_timeout_put. So only when the
334 * current refcnt is 1, we decrease it to 0.
335 */
336 if (atomic_cmpxchg(&timeout->refcnt, 1, 0) == 1) {
337 /* We are protected by nfnl mutex. */
338 list_del_rcu(&timeout->head);
339 nf_ct_l4proto_put(timeout->l4proto);
340 ctnl_untimeout(net, timeout);
341 kfree_rcu(timeout, rcu_head);
342 } else {
343 ret = -EBUSY;
344 }
345 return ret;
346}
347
348static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
349 struct sk_buff *skb,
350 const struct nlmsghdr *nlh,
351 const struct nlattr * const cda[])
352{
353 struct ctnl_timeout *cur;
354 int ret = -ENOENT;
355 char *name;
356
357 if (!cda[CTA_TIMEOUT_NAME]) {
358 list_for_each_entry(cur, &net->nfct_timeout_list, head)
359 ctnl_timeout_try_del(net, cur);
360
361 return 0;
362 }
363 name = nla_data(cda[CTA_TIMEOUT_NAME]);
364
365 list_for_each_entry(cur, &net->nfct_timeout_list, head) {
366 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
367 continue;
368
369 ret = ctnl_timeout_try_del(net, cur);
370 if (ret < 0)
371 return ret;
372
373 break;
374 }
375 return ret;
376}
377
378static int cttimeout_default_set(struct net *net, struct sock *ctnl,
379 struct sk_buff *skb,
380 const struct nlmsghdr *nlh,
381 const struct nlattr * const cda[])
382{
383 __u16 l3num;
384 __u8 l4num;
385 struct nf_conntrack_l4proto *l4proto;
386 unsigned int *timeouts;
387 int ret;
388
389 if (!cda[CTA_TIMEOUT_L3PROTO] ||
390 !cda[CTA_TIMEOUT_L4PROTO] ||
391 !cda[CTA_TIMEOUT_DATA])
392 return -EINVAL;
393
394 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
395 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
396 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
397
398 /* This protocol is not supported, skip. */
399 if (l4proto->l4proto != l4num) {
400 ret = -EOPNOTSUPP;
401 goto err;
402 }
403
404 timeouts = l4proto->get_timeouts(net);
405
406 ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
407 cda[CTA_TIMEOUT_DATA]);
408 if (ret < 0)
409 goto err;
410
411 nf_ct_l4proto_put(l4proto);
412 return 0;
413err:
414 nf_ct_l4proto_put(l4proto);
415 return ret;
416}
417
418static int
419cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
420 u32 seq, u32 type, int event,
421 struct nf_conntrack_l4proto *l4proto)
422{
423 struct nlmsghdr *nlh;
424 struct nfgenmsg *nfmsg;
425 unsigned int flags = portid ? NLM_F_MULTI : 0;
426
427 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
428 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
429 if (nlh == NULL)
430 goto nlmsg_failure;
431
432 nfmsg = nlmsg_data(nlh);
433 nfmsg->nfgen_family = AF_UNSPEC;
434 nfmsg->version = NFNETLINK_V0;
435 nfmsg->res_id = 0;
436
437 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
438 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
439 goto nla_put_failure;
440
441 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
442 struct nlattr *nest_parms;
443 unsigned int *timeouts = l4proto->get_timeouts(net);
444 int ret;
445
446 nest_parms = nla_nest_start(skb,
447 CTA_TIMEOUT_DATA | NLA_F_NESTED);
448 if (!nest_parms)
449 goto nla_put_failure;
450
451 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
452 if (ret < 0)
453 goto nla_put_failure;
454
455 nla_nest_end(skb, nest_parms);
456 }
457
458 nlmsg_end(skb, nlh);
459 return skb->len;
460
461nlmsg_failure:
462nla_put_failure:
463 nlmsg_cancel(skb, nlh);
464 return -1;
465}
466
467static int cttimeout_default_get(struct net *net, struct sock *ctnl,
468 struct sk_buff *skb,
469 const struct nlmsghdr *nlh,
470 const struct nlattr * const cda[])
471{
472 __u16 l3num;
473 __u8 l4num;
474 struct nf_conntrack_l4proto *l4proto;
475 struct sk_buff *skb2;
476 int ret, err;
477
478 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
479 return -EINVAL;
480
481 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
482 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
483 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
484
485 /* This protocol is not supported, skip. */
486 if (l4proto->l4proto != l4num) {
487 err = -EOPNOTSUPP;
488 goto err;
489 }
490
491 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
492 if (skb2 == NULL) {
493 err = -ENOMEM;
494 goto err;
495 }
496
497 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
498 nlh->nlmsg_seq,
499 NFNL_MSG_TYPE(nlh->nlmsg_type),
500 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
501 l4proto);
502 if (ret <= 0) {
503 kfree_skb(skb2);
504 err = -ENOMEM;
505 goto err;
506 }
507 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
508 if (ret > 0)
509 ret = 0;
510
511 /* this avoids a loop in nfnetlink. */
512 return ret == -EAGAIN ? -ENOBUFS : ret;
513err:
514 nf_ct_l4proto_put(l4proto);
515 return err;
516}
517
518#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
519static struct ctnl_timeout *
520ctnl_timeout_find_get(struct net *net, const char *name)
521{
522 struct ctnl_timeout *timeout, *matching = NULL;
523
524 rcu_read_lock();
525 list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
526 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
527 continue;
528
529 if (!try_module_get(THIS_MODULE))
530 goto err;
531
532 if (!atomic_inc_not_zero(&timeout->refcnt)) {
533 module_put(THIS_MODULE);
534 goto err;
535 }
536 matching = timeout;
537 break;
538 }
539err:
540 rcu_read_unlock();
541 return matching;
542}
543
544static void ctnl_timeout_put(struct ctnl_timeout *timeout)
545{
546 if (atomic_dec_and_test(&timeout->refcnt))
547 kfree_rcu(timeout, rcu_head);
548
549 module_put(THIS_MODULE);
550}
551#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
552
553static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
554 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
555 .attr_count = CTA_TIMEOUT_MAX,
556 .policy = cttimeout_nla_policy },
557 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy },
560 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
561 .attr_count = CTA_TIMEOUT_MAX,
562 .policy = cttimeout_nla_policy },
563 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
564 .attr_count = CTA_TIMEOUT_MAX,
565 .policy = cttimeout_nla_policy },
566 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
567 .attr_count = CTA_TIMEOUT_MAX,
568 .policy = cttimeout_nla_policy },
569};
570
571static const struct nfnetlink_subsystem cttimeout_subsys = {
572 .name = "conntrack_timeout",
573 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
574 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
575 .cb = cttimeout_cb,
576};
577
578MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
579
580static int __net_init cttimeout_net_init(struct net *net)
581{
582 INIT_LIST_HEAD(&net->nfct_timeout_list);
583
584 return 0;
585}
586
587static void __net_exit cttimeout_net_exit(struct net *net)
588{
589 struct ctnl_timeout *cur, *tmp;
590
591 ctnl_untimeout(net, NULL);
592
593 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
594 list_del_rcu(&cur->head);
595 nf_ct_l4proto_put(cur->l4proto);
596
597 if (atomic_dec_and_test(&cur->refcnt))
598 kfree_rcu(cur, rcu_head);
599 }
600}
601
602static struct pernet_operations cttimeout_ops = {
603 .init = cttimeout_net_init,
604 .exit = cttimeout_net_exit,
605};
606
607static int __init cttimeout_init(void)
608{
609 int ret;
610
611 ret = register_pernet_subsys(&cttimeout_ops);
612 if (ret < 0)
613 return ret;
614
615 ret = nfnetlink_subsys_register(&cttimeout_subsys);
616 if (ret < 0) {
617 pr_err("cttimeout_init: cannot register cttimeout with "
618 "nfnetlink.\n");
619 goto err_out;
620 }
621#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
622 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
623 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
624#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
625 return 0;
626
627err_out:
628 unregister_pernet_subsys(&cttimeout_ops);
629 return ret;
630}
631
632static void __exit cttimeout_exit(void)
633{
634 pr_info("cttimeout: unregistering from nfnetlink.\n");
635
636 nfnetlink_subsys_unregister(&cttimeout_subsys);
637
638 unregister_pernet_subsys(&cttimeout_ops);
639#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
640 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
641 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
642#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
643 rcu_barrier();
644}
645
646module_init(cttimeout_init);
647module_exit(cttimeout_exit);