Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
5 */
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/rculist.h>
10#include <linux/rculist_nulls.h>
11#include <linux/types.h>
12#include <linux/timer.h>
13#include <linux/security.h>
14#include <linux/skbuff.h>
15#include <linux/errno.h>
16#include <linux/netlink.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20
21#include <linux/netfilter.h>
22#include <net/netlink.h>
23#include <net/netns/generic.h>
24#include <net/sock.h>
25#include <net/netfilter/nf_conntrack.h>
26#include <net/netfilter/nf_conntrack_core.h>
27#include <net/netfilter/nf_conntrack_l4proto.h>
28#include <net/netfilter/nf_conntrack_tuple.h>
29#include <net/netfilter/nf_conntrack_timeout.h>
30
31#include <linux/netfilter/nfnetlink.h>
32#include <linux/netfilter/nfnetlink_cttimeout.h>
33
34static unsigned int nfct_timeout_id __read_mostly;
35
36struct nfct_timeout_pernet {
37 struct list_head nfct_timeout_list;
38};
39
40MODULE_LICENSE("GPL");
41MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
42MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
43
44static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
45 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
46 .len = CTNL_TIMEOUT_NAME_MAX - 1},
47 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
48 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
49 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
50};
51
52static struct nfct_timeout_pernet *nfct_timeout_pernet(struct net *net)
53{
54 return net_generic(net, nfct_timeout_id);
55}
56
57static int
58ctnl_timeout_parse_policy(void *timeout,
59 const struct nf_conntrack_l4proto *l4proto,
60 struct net *net, const struct nlattr *attr)
61{
62 struct nlattr **tb;
63 int ret = 0;
64
65 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
66 GFP_KERNEL);
67
68 if (!tb)
69 return -ENOMEM;
70
71 ret = nla_parse_nested_deprecated(tb,
72 l4proto->ctnl_timeout.nlattr_max,
73 attr,
74 l4proto->ctnl_timeout.nla_policy,
75 NULL);
76 if (ret < 0)
77 goto err;
78
79 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
80
81err:
82 kfree(tb);
83 return ret;
84}
85
86static int cttimeout_new_timeout(struct sk_buff *skb,
87 const struct nfnl_info *info,
88 const struct nlattr * const cda[])
89{
90 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
91 __u16 l3num;
92 __u8 l4num;
93 const struct nf_conntrack_l4proto *l4proto;
94 struct ctnl_timeout *timeout, *matching = NULL;
95 char *name;
96 int ret;
97
98 if (!cda[CTA_TIMEOUT_NAME] ||
99 !cda[CTA_TIMEOUT_L3PROTO] ||
100 !cda[CTA_TIMEOUT_L4PROTO] ||
101 !cda[CTA_TIMEOUT_DATA])
102 return -EINVAL;
103
104 name = nla_data(cda[CTA_TIMEOUT_NAME]);
105 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
106 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
107
108 list_for_each_entry(timeout, &pernet->nfct_timeout_list, head) {
109 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
110 continue;
111
112 if (info->nlh->nlmsg_flags & NLM_F_EXCL)
113 return -EEXIST;
114
115 matching = timeout;
116 break;
117 }
118
119 if (matching) {
120 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
121 /* You cannot replace one timeout policy by another of
122 * different kind, sorry.
123 */
124 if (matching->timeout.l3num != l3num ||
125 matching->timeout.l4proto->l4proto != l4num)
126 return -EINVAL;
127
128 return ctnl_timeout_parse_policy(&matching->timeout.data,
129 matching->timeout.l4proto,
130 info->net,
131 cda[CTA_TIMEOUT_DATA]);
132 }
133
134 return -EBUSY;
135 }
136
137 l4proto = nf_ct_l4proto_find(l4num);
138
139 /* This protocol is not supportted, skip. */
140 if (l4proto->l4proto != l4num) {
141 ret = -EOPNOTSUPP;
142 goto err_proto_put;
143 }
144
145 timeout = kzalloc(sizeof(struct ctnl_timeout) +
146 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
147 if (timeout == NULL) {
148 ret = -ENOMEM;
149 goto err_proto_put;
150 }
151
152 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto,
153 info->net, cda[CTA_TIMEOUT_DATA]);
154 if (ret < 0)
155 goto err;
156
157 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
158 timeout->timeout.l3num = l3num;
159 timeout->timeout.l4proto = l4proto;
160 refcount_set(&timeout->refcnt, 1);
161 list_add_tail_rcu(&timeout->head, &pernet->nfct_timeout_list);
162
163 return 0;
164err:
165 kfree(timeout);
166err_proto_put:
167 return ret;
168}
169
170static int
171ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
172 int event, struct ctnl_timeout *timeout)
173{
174 struct nlmsghdr *nlh;
175 unsigned int flags = portid ? NLM_F_MULTI : 0;
176 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
177 struct nlattr *nest_parms;
178 int ret;
179
180 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
181 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
182 NFNETLINK_V0, 0);
183 if (!nlh)
184 goto nlmsg_failure;
185
186 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
187 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
188 htons(timeout->timeout.l3num)) ||
189 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
190 nla_put_be32(skb, CTA_TIMEOUT_USE,
191 htonl(refcount_read(&timeout->refcnt))))
192 goto nla_put_failure;
193
194 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
195 if (!nest_parms)
196 goto nla_put_failure;
197
198 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
199 if (ret < 0)
200 goto nla_put_failure;
201
202 nla_nest_end(skb, nest_parms);
203
204 nlmsg_end(skb, nlh);
205 return skb->len;
206
207nlmsg_failure:
208nla_put_failure:
209 nlmsg_cancel(skb, nlh);
210 return -1;
211}
212
213static int
214ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
215{
216 struct nfct_timeout_pernet *pernet;
217 struct net *net = sock_net(skb->sk);
218 struct ctnl_timeout *cur, *last;
219
220 if (cb->args[2])
221 return 0;
222
223 last = (struct ctnl_timeout *)cb->args[1];
224 if (cb->args[1])
225 cb->args[1] = 0;
226
227 rcu_read_lock();
228 pernet = nfct_timeout_pernet(net);
229 list_for_each_entry_rcu(cur, &pernet->nfct_timeout_list, head) {
230 if (last) {
231 if (cur != last)
232 continue;
233
234 last = NULL;
235 }
236 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
237 cb->nlh->nlmsg_seq,
238 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
239 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
240 cb->args[1] = (unsigned long)cur;
241 break;
242 }
243 }
244 if (!cb->args[1])
245 cb->args[2] = 1;
246 rcu_read_unlock();
247 return skb->len;
248}
249
250static int cttimeout_get_timeout(struct sk_buff *skb,
251 const struct nfnl_info *info,
252 const struct nlattr * const cda[])
253{
254 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
255 int ret = -ENOENT;
256 char *name;
257 struct ctnl_timeout *cur;
258
259 if (info->nlh->nlmsg_flags & NLM_F_DUMP) {
260 struct netlink_dump_control c = {
261 .dump = ctnl_timeout_dump,
262 };
263 return netlink_dump_start(info->sk, skb, info->nlh, &c);
264 }
265
266 if (!cda[CTA_TIMEOUT_NAME])
267 return -EINVAL;
268 name = nla_data(cda[CTA_TIMEOUT_NAME]);
269
270 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
271 struct sk_buff *skb2;
272
273 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
274 continue;
275
276 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
277 if (skb2 == NULL) {
278 ret = -ENOMEM;
279 break;
280 }
281
282 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
283 info->nlh->nlmsg_seq,
284 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
285 IPCTNL_MSG_TIMEOUT_NEW, cur);
286 if (ret <= 0) {
287 kfree_skb(skb2);
288 break;
289 }
290
291 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
292 break;
293 }
294
295 return ret;
296}
297
298/* try to delete object, fail if it is still in use. */
299static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
300{
301 int ret = 0;
302
303 /* We want to avoid races with ctnl_timeout_put. So only when the
304 * current refcnt is 1, we decrease it to 0.
305 */
306 if (refcount_dec_if_one(&timeout->refcnt)) {
307 /* We are protected by nfnl mutex. */
308 list_del_rcu(&timeout->head);
309 nf_ct_untimeout(net, &timeout->timeout);
310 kfree_rcu(timeout, rcu_head);
311 } else {
312 ret = -EBUSY;
313 }
314 return ret;
315}
316
317static int cttimeout_del_timeout(struct sk_buff *skb,
318 const struct nfnl_info *info,
319 const struct nlattr * const cda[])
320{
321 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
322 struct ctnl_timeout *cur, *tmp;
323 int ret = -ENOENT;
324 char *name;
325
326 if (!cda[CTA_TIMEOUT_NAME]) {
327 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list,
328 head)
329 ctnl_timeout_try_del(info->net, cur);
330
331 return 0;
332 }
333 name = nla_data(cda[CTA_TIMEOUT_NAME]);
334
335 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
336 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
337 continue;
338
339 ret = ctnl_timeout_try_del(info->net, cur);
340 if (ret < 0)
341 return ret;
342
343 break;
344 }
345 return ret;
346}
347
348static int cttimeout_default_set(struct sk_buff *skb,
349 const struct nfnl_info *info,
350 const struct nlattr * const cda[])
351{
352 const struct nf_conntrack_l4proto *l4proto;
353 __u8 l4num;
354 int ret;
355
356 if (!cda[CTA_TIMEOUT_L3PROTO] ||
357 !cda[CTA_TIMEOUT_L4PROTO] ||
358 !cda[CTA_TIMEOUT_DATA])
359 return -EINVAL;
360
361 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
362 l4proto = nf_ct_l4proto_find(l4num);
363
364 /* This protocol is not supported, skip. */
365 if (l4proto->l4proto != l4num) {
366 ret = -EOPNOTSUPP;
367 goto err;
368 }
369
370 ret = ctnl_timeout_parse_policy(NULL, l4proto, info->net,
371 cda[CTA_TIMEOUT_DATA]);
372 if (ret < 0)
373 goto err;
374
375 return 0;
376err:
377 return ret;
378}
379
380static int
381cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
382 u32 seq, u32 type, int event, u16 l3num,
383 const struct nf_conntrack_l4proto *l4proto,
384 const unsigned int *timeouts)
385{
386 struct nlmsghdr *nlh;
387 unsigned int flags = portid ? NLM_F_MULTI : 0;
388 struct nlattr *nest_parms;
389 int ret;
390
391 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
392 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
393 NFNETLINK_V0, 0);
394 if (!nlh)
395 goto nlmsg_failure;
396
397 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
398 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
399 goto nla_put_failure;
400
401 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
402 if (!nest_parms)
403 goto nla_put_failure;
404
405 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
406 if (ret < 0)
407 goto nla_put_failure;
408
409 nla_nest_end(skb, nest_parms);
410
411 nlmsg_end(skb, nlh);
412 return skb->len;
413
414nlmsg_failure:
415nla_put_failure:
416 nlmsg_cancel(skb, nlh);
417 return -1;
418}
419
420static int cttimeout_default_get(struct sk_buff *skb,
421 const struct nfnl_info *info,
422 const struct nlattr * const cda[])
423{
424 const struct nf_conntrack_l4proto *l4proto;
425 unsigned int *timeouts = NULL;
426 struct sk_buff *skb2;
427 __u16 l3num;
428 __u8 l4num;
429 int ret;
430
431 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
432 return -EINVAL;
433
434 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
435 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
436 l4proto = nf_ct_l4proto_find(l4num);
437
438 if (l4proto->l4proto != l4num)
439 return -EOPNOTSUPP;
440
441 switch (l4proto->l4proto) {
442 case IPPROTO_ICMP:
443 timeouts = &nf_icmp_pernet(info->net)->timeout;
444 break;
445 case IPPROTO_TCP:
446 timeouts = nf_tcp_pernet(info->net)->timeouts;
447 break;
448 case IPPROTO_UDP:
449 case IPPROTO_UDPLITE:
450 timeouts = nf_udp_pernet(info->net)->timeouts;
451 break;
452 case IPPROTO_DCCP:
453#ifdef CONFIG_NF_CT_PROTO_DCCP
454 timeouts = nf_dccp_pernet(info->net)->dccp_timeout;
455#endif
456 break;
457 case IPPROTO_ICMPV6:
458 timeouts = &nf_icmpv6_pernet(info->net)->timeout;
459 break;
460 case IPPROTO_SCTP:
461#ifdef CONFIG_NF_CT_PROTO_SCTP
462 timeouts = nf_sctp_pernet(info->net)->timeouts;
463#endif
464 break;
465 case IPPROTO_GRE:
466#ifdef CONFIG_NF_CT_PROTO_GRE
467 timeouts = nf_gre_pernet(info->net)->timeouts;
468#endif
469 break;
470 case 255:
471 timeouts = &nf_generic_pernet(info->net)->timeout;
472 break;
473 default:
474 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
475 break;
476 }
477
478 if (!timeouts)
479 return -EOPNOTSUPP;
480
481 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
482 if (!skb2)
483 return -ENOMEM;
484
485 ret = cttimeout_default_fill_info(info->net, skb2,
486 NETLINK_CB(skb).portid,
487 info->nlh->nlmsg_seq,
488 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
489 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
490 l3num, l4proto, timeouts);
491 if (ret <= 0) {
492 kfree_skb(skb2);
493 return -ENOMEM;
494 }
495
496 return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
497}
498
499static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
500 const char *name)
501{
502 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
503 struct ctnl_timeout *timeout, *matching = NULL;
504
505 list_for_each_entry_rcu(timeout, &pernet->nfct_timeout_list, head) {
506 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
507 continue;
508
509 if (!try_module_get(THIS_MODULE))
510 goto err;
511
512 if (!refcount_inc_not_zero(&timeout->refcnt)) {
513 module_put(THIS_MODULE);
514 goto err;
515 }
516 matching = timeout;
517 break;
518 }
519err:
520 return matching ? &matching->timeout : NULL;
521}
522
523static void ctnl_timeout_put(struct nf_ct_timeout *t)
524{
525 struct ctnl_timeout *timeout =
526 container_of(t, struct ctnl_timeout, timeout);
527
528 if (refcount_dec_and_test(&timeout->refcnt))
529 kfree_rcu(timeout, rcu_head);
530
531 module_put(THIS_MODULE);
532}
533
534static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
535 [IPCTNL_MSG_TIMEOUT_NEW] = {
536 .call = cttimeout_new_timeout,
537 .type = NFNL_CB_MUTEX,
538 .attr_count = CTA_TIMEOUT_MAX,
539 .policy = cttimeout_nla_policy
540 },
541 [IPCTNL_MSG_TIMEOUT_GET] = {
542 .call = cttimeout_get_timeout,
543 .type = NFNL_CB_MUTEX,
544 .attr_count = CTA_TIMEOUT_MAX,
545 .policy = cttimeout_nla_policy
546 },
547 [IPCTNL_MSG_TIMEOUT_DELETE] = {
548 .call = cttimeout_del_timeout,
549 .type = NFNL_CB_MUTEX,
550 .attr_count = CTA_TIMEOUT_MAX,
551 .policy = cttimeout_nla_policy
552 },
553 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET] = {
554 .call = cttimeout_default_set,
555 .type = NFNL_CB_MUTEX,
556 .attr_count = CTA_TIMEOUT_MAX,
557 .policy = cttimeout_nla_policy
558 },
559 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET] = {
560 .call = cttimeout_default_get,
561 .type = NFNL_CB_MUTEX,
562 .attr_count = CTA_TIMEOUT_MAX,
563 .policy = cttimeout_nla_policy
564 },
565};
566
567static const struct nfnetlink_subsystem cttimeout_subsys = {
568 .name = "conntrack_timeout",
569 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
570 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
571 .cb = cttimeout_cb,
572};
573
574MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
575
576static int __net_init cttimeout_net_init(struct net *net)
577{
578 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
579
580 INIT_LIST_HEAD(&pernet->nfct_timeout_list);
581
582 return 0;
583}
584
585static void __net_exit cttimeout_net_exit(struct net *net)
586{
587 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
588 struct ctnl_timeout *cur, *tmp;
589
590 nf_ct_unconfirmed_destroy(net);
591 nf_ct_untimeout(net, NULL);
592
593 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
594 list_del_rcu(&cur->head);
595
596 if (refcount_dec_and_test(&cur->refcnt))
597 kfree_rcu(cur, rcu_head);
598 }
599}
600
601static struct pernet_operations cttimeout_ops = {
602 .init = cttimeout_net_init,
603 .exit = cttimeout_net_exit,
604 .id = &nfct_timeout_id,
605 .size = sizeof(struct nfct_timeout_pernet),
606};
607
608static int __init cttimeout_init(void)
609{
610 int ret;
611
612 ret = register_pernet_subsys(&cttimeout_ops);
613 if (ret < 0)
614 return ret;
615
616 ret = nfnetlink_subsys_register(&cttimeout_subsys);
617 if (ret < 0) {
618 pr_err("cttimeout_init: cannot register cttimeout with "
619 "nfnetlink.\n");
620 goto err_out;
621 }
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 return 0;
625
626err_out:
627 unregister_pernet_subsys(&cttimeout_ops);
628 return ret;
629}
630
631static void __exit cttimeout_exit(void)
632{
633 nfnetlink_subsys_unregister(&cttimeout_subsys);
634
635 unregister_pernet_subsys(&cttimeout_ops);
636 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
637 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
638 synchronize_rcu();
639}
640
641module_init(cttimeout_init);
642module_exit(cttimeout_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
5 */
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/rculist.h>
10#include <linux/rculist_nulls.h>
11#include <linux/types.h>
12#include <linux/timer.h>
13#include <linux/security.h>
14#include <linux/skbuff.h>
15#include <linux/errno.h>
16#include <linux/netlink.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20
21#include <linux/netfilter.h>
22#include <net/netlink.h>
23#include <net/netns/generic.h>
24#include <net/sock.h>
25#include <net/netfilter/nf_conntrack.h>
26#include <net/netfilter/nf_conntrack_core.h>
27#include <net/netfilter/nf_conntrack_l4proto.h>
28#include <net/netfilter/nf_conntrack_tuple.h>
29#include <net/netfilter/nf_conntrack_timeout.h>
30
31#include <linux/netfilter/nfnetlink.h>
32#include <linux/netfilter/nfnetlink_cttimeout.h>
33
34static unsigned int nfct_timeout_id __read_mostly;
35
36struct ctnl_timeout {
37 struct list_head head;
38 struct list_head free_head;
39 struct rcu_head rcu_head;
40 refcount_t refcnt;
41 char name[CTNL_TIMEOUT_NAME_MAX];
42
43 /* must be at the end */
44 struct nf_ct_timeout timeout;
45};
46
47struct nfct_timeout_pernet {
48 struct list_head nfct_timeout_list;
49 struct list_head nfct_timeout_freelist;
50};
51
52MODULE_LICENSE("GPL");
53MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
54MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
55
56static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
57 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
58 .len = CTNL_TIMEOUT_NAME_MAX - 1},
59 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
60 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
61 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
62};
63
64static struct nfct_timeout_pernet *nfct_timeout_pernet(struct net *net)
65{
66 return net_generic(net, nfct_timeout_id);
67}
68
69static int
70ctnl_timeout_parse_policy(void *timeout,
71 const struct nf_conntrack_l4proto *l4proto,
72 struct net *net, const struct nlattr *attr)
73{
74 struct nlattr **tb;
75 int ret = 0;
76
77 tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
78 GFP_KERNEL);
79
80 if (!tb)
81 return -ENOMEM;
82
83 ret = nla_parse_nested_deprecated(tb,
84 l4proto->ctnl_timeout.nlattr_max,
85 attr,
86 l4proto->ctnl_timeout.nla_policy,
87 NULL);
88 if (ret < 0)
89 goto err;
90
91 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
92
93err:
94 kfree(tb);
95 return ret;
96}
97
98static int cttimeout_new_timeout(struct sk_buff *skb,
99 const struct nfnl_info *info,
100 const struct nlattr * const cda[])
101{
102 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
103 __u16 l3num;
104 __u8 l4num;
105 const struct nf_conntrack_l4proto *l4proto;
106 struct ctnl_timeout *timeout, *matching = NULL;
107 char *name;
108 int ret;
109
110 if (!cda[CTA_TIMEOUT_NAME] ||
111 !cda[CTA_TIMEOUT_L3PROTO] ||
112 !cda[CTA_TIMEOUT_L4PROTO] ||
113 !cda[CTA_TIMEOUT_DATA])
114 return -EINVAL;
115
116 name = nla_data(cda[CTA_TIMEOUT_NAME]);
117 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
118 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
119
120 list_for_each_entry(timeout, &pernet->nfct_timeout_list, head) {
121 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
122 continue;
123
124 if (info->nlh->nlmsg_flags & NLM_F_EXCL)
125 return -EEXIST;
126
127 matching = timeout;
128 break;
129 }
130
131 if (matching) {
132 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
133 /* You cannot replace one timeout policy by another of
134 * different kind, sorry.
135 */
136 if (matching->timeout.l3num != l3num ||
137 matching->timeout.l4proto->l4proto != l4num)
138 return -EINVAL;
139
140 return ctnl_timeout_parse_policy(&matching->timeout.data,
141 matching->timeout.l4proto,
142 info->net,
143 cda[CTA_TIMEOUT_DATA]);
144 }
145
146 return -EBUSY;
147 }
148
149 l4proto = nf_ct_l4proto_find(l4num);
150
151 /* This protocol is not supportted, skip. */
152 if (l4proto->l4proto != l4num) {
153 ret = -EOPNOTSUPP;
154 goto err_proto_put;
155 }
156
157 timeout = kzalloc(sizeof(struct ctnl_timeout) +
158 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
159 if (timeout == NULL) {
160 ret = -ENOMEM;
161 goto err_proto_put;
162 }
163
164 ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto,
165 info->net, cda[CTA_TIMEOUT_DATA]);
166 if (ret < 0)
167 goto err;
168
169 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
170 timeout->timeout.l3num = l3num;
171 timeout->timeout.l4proto = l4proto;
172 refcount_set(&timeout->refcnt, 1);
173 __module_get(THIS_MODULE);
174 list_add_tail_rcu(&timeout->head, &pernet->nfct_timeout_list);
175
176 return 0;
177err:
178 kfree(timeout);
179err_proto_put:
180 return ret;
181}
182
183static int
184ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
185 int event, struct ctnl_timeout *timeout)
186{
187 struct nlmsghdr *nlh;
188 unsigned int flags = portid ? NLM_F_MULTI : 0;
189 const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
190 struct nlattr *nest_parms;
191 int ret;
192
193 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
194 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
195 NFNETLINK_V0, 0);
196 if (!nlh)
197 goto nlmsg_failure;
198
199 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
200 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
201 htons(timeout->timeout.l3num)) ||
202 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
203 nla_put_be32(skb, CTA_TIMEOUT_USE,
204 htonl(refcount_read(&timeout->refcnt))))
205 goto nla_put_failure;
206
207 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
208 if (!nest_parms)
209 goto nla_put_failure;
210
211 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
212 if (ret < 0)
213 goto nla_put_failure;
214
215 nla_nest_end(skb, nest_parms);
216
217 nlmsg_end(skb, nlh);
218 return skb->len;
219
220nlmsg_failure:
221nla_put_failure:
222 nlmsg_cancel(skb, nlh);
223 return -1;
224}
225
226static int
227ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
228{
229 struct nfct_timeout_pernet *pernet;
230 struct net *net = sock_net(skb->sk);
231 struct ctnl_timeout *cur, *last;
232
233 if (cb->args[2])
234 return 0;
235
236 last = (struct ctnl_timeout *)cb->args[1];
237 if (cb->args[1])
238 cb->args[1] = 0;
239
240 rcu_read_lock();
241 pernet = nfct_timeout_pernet(net);
242 list_for_each_entry_rcu(cur, &pernet->nfct_timeout_list, head) {
243 if (last) {
244 if (cur != last)
245 continue;
246
247 last = NULL;
248 }
249 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
250 cb->nlh->nlmsg_seq,
251 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
252 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
253 cb->args[1] = (unsigned long)cur;
254 break;
255 }
256 }
257 if (!cb->args[1])
258 cb->args[2] = 1;
259 rcu_read_unlock();
260 return skb->len;
261}
262
263static int cttimeout_get_timeout(struct sk_buff *skb,
264 const struct nfnl_info *info,
265 const struct nlattr * const cda[])
266{
267 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
268 int ret = -ENOENT;
269 char *name;
270 struct ctnl_timeout *cur;
271
272 if (info->nlh->nlmsg_flags & NLM_F_DUMP) {
273 struct netlink_dump_control c = {
274 .dump = ctnl_timeout_dump,
275 };
276 return netlink_dump_start(info->sk, skb, info->nlh, &c);
277 }
278
279 if (!cda[CTA_TIMEOUT_NAME])
280 return -EINVAL;
281 name = nla_data(cda[CTA_TIMEOUT_NAME]);
282
283 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
284 struct sk_buff *skb2;
285
286 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
287 continue;
288
289 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
290 if (skb2 == NULL) {
291 ret = -ENOMEM;
292 break;
293 }
294
295 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
296 info->nlh->nlmsg_seq,
297 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
298 IPCTNL_MSG_TIMEOUT_NEW, cur);
299 if (ret <= 0) {
300 kfree_skb(skb2);
301 break;
302 }
303
304 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
305 break;
306 }
307
308 return ret;
309}
310
311/* try to delete object, fail if it is still in use. */
312static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
313{
314 int ret = 0;
315
316 /* We want to avoid races with ctnl_timeout_put. So only when the
317 * current refcnt is 1, we decrease it to 0.
318 */
319 if (refcount_dec_if_one(&timeout->refcnt)) {
320 /* We are protected by nfnl mutex. */
321 list_del_rcu(&timeout->head);
322 nf_ct_untimeout(net, &timeout->timeout);
323 kfree_rcu(timeout, rcu_head);
324 } else {
325 ret = -EBUSY;
326 }
327 return ret;
328}
329
330static int cttimeout_del_timeout(struct sk_buff *skb,
331 const struct nfnl_info *info,
332 const struct nlattr * const cda[])
333{
334 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(info->net);
335 struct ctnl_timeout *cur, *tmp;
336 int ret = -ENOENT;
337 char *name;
338
339 if (!cda[CTA_TIMEOUT_NAME]) {
340 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list,
341 head)
342 ctnl_timeout_try_del(info->net, cur);
343
344 return 0;
345 }
346 name = nla_data(cda[CTA_TIMEOUT_NAME]);
347
348 list_for_each_entry(cur, &pernet->nfct_timeout_list, head) {
349 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
350 continue;
351
352 ret = ctnl_timeout_try_del(info->net, cur);
353 if (ret < 0)
354 return ret;
355
356 break;
357 }
358 return ret;
359}
360
361static int cttimeout_default_set(struct sk_buff *skb,
362 const struct nfnl_info *info,
363 const struct nlattr * const cda[])
364{
365 const struct nf_conntrack_l4proto *l4proto;
366 __u8 l4num;
367 int ret;
368
369 if (!cda[CTA_TIMEOUT_L3PROTO] ||
370 !cda[CTA_TIMEOUT_L4PROTO] ||
371 !cda[CTA_TIMEOUT_DATA])
372 return -EINVAL;
373
374 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
375 l4proto = nf_ct_l4proto_find(l4num);
376
377 /* This protocol is not supported, skip. */
378 if (l4proto->l4proto != l4num) {
379 ret = -EOPNOTSUPP;
380 goto err;
381 }
382
383 ret = ctnl_timeout_parse_policy(NULL, l4proto, info->net,
384 cda[CTA_TIMEOUT_DATA]);
385 if (ret < 0)
386 goto err;
387
388 return 0;
389err:
390 return ret;
391}
392
393static int
394cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
395 u32 seq, u32 type, int event, u16 l3num,
396 const struct nf_conntrack_l4proto *l4proto,
397 const unsigned int *timeouts)
398{
399 struct nlmsghdr *nlh;
400 unsigned int flags = portid ? NLM_F_MULTI : 0;
401 struct nlattr *nest_parms;
402 int ret;
403
404 event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
405 nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
406 NFNETLINK_V0, 0);
407 if (!nlh)
408 goto nlmsg_failure;
409
410 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
411 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
412 goto nla_put_failure;
413
414 nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
415 if (!nest_parms)
416 goto nla_put_failure;
417
418 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
419 if (ret < 0)
420 goto nla_put_failure;
421
422 nla_nest_end(skb, nest_parms);
423
424 nlmsg_end(skb, nlh);
425 return skb->len;
426
427nlmsg_failure:
428nla_put_failure:
429 nlmsg_cancel(skb, nlh);
430 return -1;
431}
432
433static int cttimeout_default_get(struct sk_buff *skb,
434 const struct nfnl_info *info,
435 const struct nlattr * const cda[])
436{
437 const struct nf_conntrack_l4proto *l4proto;
438 unsigned int *timeouts = NULL;
439 struct sk_buff *skb2;
440 __u16 l3num;
441 __u8 l4num;
442 int ret;
443
444 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
445 return -EINVAL;
446
447 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
448 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
449 l4proto = nf_ct_l4proto_find(l4num);
450
451 if (l4proto->l4proto != l4num)
452 return -EOPNOTSUPP;
453
454 switch (l4proto->l4proto) {
455 case IPPROTO_ICMP:
456 timeouts = &nf_icmp_pernet(info->net)->timeout;
457 break;
458 case IPPROTO_TCP:
459 timeouts = nf_tcp_pernet(info->net)->timeouts;
460 break;
461 case IPPROTO_UDP:
462 case IPPROTO_UDPLITE:
463 timeouts = nf_udp_pernet(info->net)->timeouts;
464 break;
465 case IPPROTO_DCCP:
466#ifdef CONFIG_NF_CT_PROTO_DCCP
467 timeouts = nf_dccp_pernet(info->net)->dccp_timeout;
468#endif
469 break;
470 case IPPROTO_ICMPV6:
471 timeouts = &nf_icmpv6_pernet(info->net)->timeout;
472 break;
473 case IPPROTO_SCTP:
474#ifdef CONFIG_NF_CT_PROTO_SCTP
475 timeouts = nf_sctp_pernet(info->net)->timeouts;
476#endif
477 break;
478 case IPPROTO_GRE:
479#ifdef CONFIG_NF_CT_PROTO_GRE
480 timeouts = nf_gre_pernet(info->net)->timeouts;
481#endif
482 break;
483 case 255:
484 timeouts = &nf_generic_pernet(info->net)->timeout;
485 break;
486 default:
487 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
488 break;
489 }
490
491 if (!timeouts)
492 return -EOPNOTSUPP;
493
494 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
495 if (!skb2)
496 return -ENOMEM;
497
498 ret = cttimeout_default_fill_info(info->net, skb2,
499 NETLINK_CB(skb).portid,
500 info->nlh->nlmsg_seq,
501 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
502 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
503 l3num, l4proto, timeouts);
504 if (ret <= 0) {
505 kfree_skb(skb2);
506 return -ENOMEM;
507 }
508
509 return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
510}
511
512static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
513 const char *name)
514{
515 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
516 struct ctnl_timeout *timeout, *matching = NULL;
517
518 list_for_each_entry_rcu(timeout, &pernet->nfct_timeout_list, head) {
519 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
520 continue;
521
522 if (!refcount_inc_not_zero(&timeout->refcnt))
523 goto err;
524 matching = timeout;
525 break;
526 }
527err:
528 return matching ? &matching->timeout : NULL;
529}
530
531static void ctnl_timeout_put(struct nf_ct_timeout *t)
532{
533 struct ctnl_timeout *timeout =
534 container_of(t, struct ctnl_timeout, timeout);
535
536 if (refcount_dec_and_test(&timeout->refcnt)) {
537 kfree_rcu(timeout, rcu_head);
538 module_put(THIS_MODULE);
539 }
540}
541
542static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
543 [IPCTNL_MSG_TIMEOUT_NEW] = {
544 .call = cttimeout_new_timeout,
545 .type = NFNL_CB_MUTEX,
546 .attr_count = CTA_TIMEOUT_MAX,
547 .policy = cttimeout_nla_policy
548 },
549 [IPCTNL_MSG_TIMEOUT_GET] = {
550 .call = cttimeout_get_timeout,
551 .type = NFNL_CB_MUTEX,
552 .attr_count = CTA_TIMEOUT_MAX,
553 .policy = cttimeout_nla_policy
554 },
555 [IPCTNL_MSG_TIMEOUT_DELETE] = {
556 .call = cttimeout_del_timeout,
557 .type = NFNL_CB_MUTEX,
558 .attr_count = CTA_TIMEOUT_MAX,
559 .policy = cttimeout_nla_policy
560 },
561 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET] = {
562 .call = cttimeout_default_set,
563 .type = NFNL_CB_MUTEX,
564 .attr_count = CTA_TIMEOUT_MAX,
565 .policy = cttimeout_nla_policy
566 },
567 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET] = {
568 .call = cttimeout_default_get,
569 .type = NFNL_CB_MUTEX,
570 .attr_count = CTA_TIMEOUT_MAX,
571 .policy = cttimeout_nla_policy
572 },
573};
574
575static const struct nfnetlink_subsystem cttimeout_subsys = {
576 .name = "conntrack_timeout",
577 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
578 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
579 .cb = cttimeout_cb,
580};
581
582MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
583
584static int __net_init cttimeout_net_init(struct net *net)
585{
586 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
587
588 INIT_LIST_HEAD(&pernet->nfct_timeout_list);
589 INIT_LIST_HEAD(&pernet->nfct_timeout_freelist);
590
591 return 0;
592}
593
594static void __net_exit cttimeout_net_pre_exit(struct net *net)
595{
596 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
597 struct ctnl_timeout *cur, *tmp;
598
599 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
600 list_del_rcu(&cur->head);
601 list_add(&cur->free_head, &pernet->nfct_timeout_freelist);
602 }
603
604 /* core calls synchronize_rcu() after this */
605}
606
607static void __net_exit cttimeout_net_exit(struct net *net)
608{
609 struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
610 struct ctnl_timeout *cur, *tmp;
611
612 if (list_empty(&pernet->nfct_timeout_freelist))
613 return;
614
615 nf_ct_untimeout(net, NULL);
616
617 list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_freelist, free_head) {
618 list_del(&cur->free_head);
619
620 if (refcount_dec_and_test(&cur->refcnt))
621 kfree_rcu(cur, rcu_head);
622 }
623}
624
625static struct pernet_operations cttimeout_ops = {
626 .init = cttimeout_net_init,
627 .pre_exit = cttimeout_net_pre_exit,
628 .exit = cttimeout_net_exit,
629 .id = &nfct_timeout_id,
630 .size = sizeof(struct nfct_timeout_pernet),
631};
632
633static const struct nf_ct_timeout_hooks hooks = {
634 .timeout_find_get = ctnl_timeout_find_get,
635 .timeout_put = ctnl_timeout_put,
636};
637
638static int __init cttimeout_init(void)
639{
640 int ret;
641
642 ret = register_pernet_subsys(&cttimeout_ops);
643 if (ret < 0)
644 return ret;
645
646 ret = nfnetlink_subsys_register(&cttimeout_subsys);
647 if (ret < 0) {
648 pr_err("cttimeout_init: cannot register cttimeout with "
649 "nfnetlink.\n");
650 goto err_out;
651 }
652 RCU_INIT_POINTER(nf_ct_timeout_hook, &hooks);
653 return 0;
654
655err_out:
656 unregister_pernet_subsys(&cttimeout_ops);
657 return ret;
658}
659
660static int untimeout(struct nf_conn *ct, void *timeout)
661{
662 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
663
664 if (timeout_ext)
665 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
666
667 return 0;
668}
669
670static void __exit cttimeout_exit(void)
671{
672 nfnetlink_subsys_unregister(&cttimeout_subsys);
673
674 unregister_pernet_subsys(&cttimeout_ops);
675 RCU_INIT_POINTER(nf_ct_timeout_hook, NULL);
676
677 nf_ct_iterate_destroy(untimeout, NULL);
678}
679
680module_init(cttimeout_init);
681module_exit(cttimeout_exit);