1
2
3
4
5
6
7
8
9
10
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13#include <linux/init.h>
14#include <linux/ip.h>
15#include <linux/ipv6.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/proc_fs.h>
19#include <linux/seq_file.h>
20#include <linux/string.h>
21#include <linux/ctype.h>
22#include <linux/list.h>
23#include <linux/random.h>
24#include <linux/jhash.h>
25#include <linux/bitops.h>
26#include <linux/skbuff.h>
27#include <linux/inet.h>
28#include <linux/slab.h>
29#include <linux/vmalloc.h>
30#include <net/net_namespace.h>
31#include <net/netns/generic.h>
32
33#include <linux/netfilter/x_tables.h>
34#include <linux/netfilter/xt_recent.h>
35
36MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
37MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
38MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
39MODULE_LICENSE("GPL");
40MODULE_ALIAS("ipt_recent");
41MODULE_ALIAS("ip6t_recent");
42
43static unsigned int ip_list_tot __read_mostly = 100;
44static unsigned int ip_list_hash_size __read_mostly;
45static unsigned int ip_list_perms __read_mostly = 0644;
46static unsigned int ip_list_uid __read_mostly;
47static unsigned int ip_list_gid __read_mostly;
48module_param(ip_list_tot, uint, 0400);
49module_param(ip_list_hash_size, uint, 0400);
50module_param(ip_list_perms, uint, 0400);
51module_param(ip_list_uid, uint, 0644);
52module_param(ip_list_gid, uint, 0644);
53MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
54MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
55MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
56MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
57MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
58
59
60static unsigned int ip_pkt_list_tot __read_mostly;
61module_param(ip_pkt_list_tot, uint, 0400);
62MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
63
64#define XT_RECENT_MAX_NSTAMPS 256
65
66struct recent_entry {
67 struct list_head list;
68 struct list_head lru_list;
69 union nf_inet_addr addr;
70 u_int16_t family;
71 u_int8_t ttl;
72 u_int8_t index;
73 u_int16_t nstamps;
74 unsigned long stamps[];
75};
76
77struct recent_table {
78 struct list_head list;
79 char name[XT_RECENT_NAME_LEN];
80 union nf_inet_addr mask;
81 unsigned int refcnt;
82 unsigned int entries;
83 u8 nstamps_max_mask;
84 struct list_head lru_list;
85 struct list_head iphash[];
86};
87
88struct recent_net {
89 struct list_head tables;
90#ifdef CONFIG_PROC_FS
91 struct proc_dir_entry *xt_recent;
92#endif
93};
94
95static unsigned int recent_net_id __read_mostly;
96
97static inline struct recent_net *recent_pernet(struct net *net)
98{
99 return net_generic(net, recent_net_id);
100}
101
102static DEFINE_SPINLOCK(recent_lock);
103static DEFINE_MUTEX(recent_mutex);
104
105#ifdef CONFIG_PROC_FS
106static const struct proc_ops recent_mt_proc_ops;
107#endif
108
109static u_int32_t hash_rnd __read_mostly;
110
111static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
112{
113 return jhash_1word((__force u32)addr->ip, hash_rnd) &
114 (ip_list_hash_size - 1);
115}
116
117static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
118{
119 return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
120 (ip_list_hash_size - 1);
121}
122
123static struct recent_entry *
124recent_entry_lookup(const struct recent_table *table,
125 const union nf_inet_addr *addrp, u_int16_t family,
126 u_int8_t ttl)
127{
128 struct recent_entry *e;
129 unsigned int h;
130
131 if (family == NFPROTO_IPV4)
132 h = recent_entry_hash4(addrp);
133 else
134 h = recent_entry_hash6(addrp);
135
136 list_for_each_entry(e, &table->iphash[h], list)
137 if (e->family == family &&
138 memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
139 (ttl == e->ttl || ttl == 0 || e->ttl == 0))
140 return e;
141 return NULL;
142}
143
144static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
145{
146 list_del(&e->list);
147 list_del(&e->lru_list);
148 kfree(e);
149 t->entries--;
150}
151
152
153
154
155static void recent_entry_reap(struct recent_table *t, unsigned long time)
156{
157 struct recent_entry *e;
158
159
160
161
162 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
163
164
165
166
167 if (time_after(time, e->stamps[e->index-1]))
168 recent_entry_remove(t, e);
169}
170
171static struct recent_entry *
172recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
173 u_int16_t family, u_int8_t ttl)
174{
175 struct recent_entry *e;
176 unsigned int nstamps_max = t->nstamps_max_mask;
177
178 if (t->entries >= ip_list_tot) {
179 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
180 recent_entry_remove(t, e);
181 }
182
183 nstamps_max += 1;
184 e = kmalloc(struct_size(e, stamps, nstamps_max), GFP_ATOMIC);
185 if (e == NULL)
186 return NULL;
187 memcpy(&e->addr, addr, sizeof(e->addr));
188 e->ttl = ttl;
189 e->stamps[0] = jiffies;
190 e->nstamps = 1;
191 e->index = 1;
192 e->family = family;
193 if (family == NFPROTO_IPV4)
194 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
195 else
196 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
197 list_add_tail(&e->lru_list, &t->lru_list);
198 t->entries++;
199 return e;
200}
201
202static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
203{
204 e->index &= t->nstamps_max_mask;
205 e->stamps[e->index++] = jiffies;
206 if (e->index > e->nstamps)
207 e->nstamps = e->index;
208 list_move_tail(&e->lru_list, &t->lru_list);
209}
210
211static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
212 const char *name)
213{
214 struct recent_table *t;
215
216 list_for_each_entry(t, &recent_net->tables, list)
217 if (!strcmp(t->name, name))
218 return t;
219 return NULL;
220}
221
222static void recent_table_flush(struct recent_table *t)
223{
224 struct recent_entry *e, *next;
225 unsigned int i;
226
227 for (i = 0; i < ip_list_hash_size; i++)
228 list_for_each_entry_safe(e, next, &t->iphash[i], list)
229 recent_entry_remove(t, e);
230}
231
232static bool
233recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
234{
235 struct net *net = xt_net(par);
236 struct recent_net *recent_net = recent_pernet(net);
237 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
238 struct recent_table *t;
239 struct recent_entry *e;
240 union nf_inet_addr addr = {}, addr_mask;
241 u_int8_t ttl;
242 bool ret = info->invert;
243
244 if (xt_family(par) == NFPROTO_IPV4) {
245 const struct iphdr *iph = ip_hdr(skb);
246
247 if (info->side == XT_RECENT_DEST)
248 addr.ip = iph->daddr;
249 else
250 addr.ip = iph->saddr;
251
252 ttl = iph->ttl;
253 } else {
254 const struct ipv6hdr *iph = ipv6_hdr(skb);
255
256 if (info->side == XT_RECENT_DEST)
257 memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
258 else
259 memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
260
261 ttl = iph->hop_limit;
262 }
263
264
265 if (xt_out(par) != NULL &&
266 (!skb->sk || !net_eq(net, sock_net(skb->sk))))
267 ttl++;
268
269 spin_lock_bh(&recent_lock);
270 t = recent_table_lookup(recent_net, info->name);
271
272 nf_inet_addr_mask(&addr, &addr_mask, &t->mask);
273
274 e = recent_entry_lookup(t, &addr_mask, xt_family(par),
275 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
276 if (e == NULL) {
277 if (!(info->check_set & XT_RECENT_SET))
278 goto out;
279 e = recent_entry_init(t, &addr_mask, xt_family(par), ttl);
280 if (e == NULL)
281 par->hotdrop = true;
282 ret = !ret;
283 goto out;
284 }
285
286 if (info->check_set & XT_RECENT_SET)
287 ret = !ret;
288 else if (info->check_set & XT_RECENT_REMOVE) {
289 recent_entry_remove(t, e);
290 ret = !ret;
291 } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
292 unsigned long time = jiffies - info->seconds * HZ;
293 unsigned int i, hits = 0;
294
295 for (i = 0; i < e->nstamps; i++) {
296 if (info->seconds && time_after(time, e->stamps[i]))
297 continue;
298 if (!info->hit_count || ++hits >= info->hit_count) {
299 ret = !ret;
300 break;
301 }
302 }
303
304
305 if (info->check_set & XT_RECENT_REAP)
306 recent_entry_reap(t, time);
307 }
308
309 if (info->check_set & XT_RECENT_SET ||
310 (info->check_set & XT_RECENT_UPDATE && ret)) {
311 recent_entry_update(t, e);
312 e->ttl = ttl;
313 }
314out:
315 spin_unlock_bh(&recent_lock);
316 return ret;
317}
318
319static void recent_table_free(void *addr)
320{
321 kvfree(addr);
322}
323
324static int recent_mt_check(const struct xt_mtchk_param *par,
325 const struct xt_recent_mtinfo_v1 *info)
326{
327 struct recent_net *recent_net = recent_pernet(par->net);
328 struct recent_table *t;
329#ifdef CONFIG_PROC_FS
330 struct proc_dir_entry *pde;
331 kuid_t uid;
332 kgid_t gid;
333#endif
334 unsigned int nstamp_mask;
335 unsigned int i;
336 int ret = -EINVAL;
337
338 net_get_random_once(&hash_rnd, sizeof(hash_rnd));
339
340 if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
341 pr_info_ratelimited("Unsupported userspace flags (%08x)\n",
342 info->check_set);
343 return -EINVAL;
344 }
345 if (hweight8(info->check_set &
346 (XT_RECENT_SET | XT_RECENT_REMOVE |
347 XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
348 return -EINVAL;
349 if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
350 (info->seconds || info->hit_count ||
351 (info->check_set & XT_RECENT_MODIFIERS)))
352 return -EINVAL;
353 if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
354 return -EINVAL;
355 if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) {
356 pr_info_ratelimited("hitcount (%u) is larger than allowed maximum (%u)\n",
357 info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
358 return -EINVAL;
359 }
360 ret = xt_check_proc_name(info->name, sizeof(info->name));
361 if (ret)
362 return ret;
363
364 if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
365 nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
366 else if (info->hit_count)
367 nstamp_mask = roundup_pow_of_two(info->hit_count) - 1;
368 else
369 nstamp_mask = 32 - 1;
370
371 mutex_lock(&recent_mutex);
372 t = recent_table_lookup(recent_net, info->name);
373 if (t != NULL) {
374 if (nstamp_mask > t->nstamps_max_mask) {
375 spin_lock_bh(&recent_lock);
376 recent_table_flush(t);
377 t->nstamps_max_mask = nstamp_mask;
378 spin_unlock_bh(&recent_lock);
379 }
380
381 t->refcnt++;
382 ret = 0;
383 goto out;
384 }
385
386 t = kvzalloc(struct_size(t, iphash, ip_list_hash_size), GFP_KERNEL);
387 if (t == NULL) {
388 ret = -ENOMEM;
389 goto out;
390 }
391 t->refcnt = 1;
392 t->nstamps_max_mask = nstamp_mask;
393
394 memcpy(&t->mask, &info->mask, sizeof(t->mask));
395 strcpy(t->name, info->name);
396 INIT_LIST_HEAD(&t->lru_list);
397 for (i = 0; i < ip_list_hash_size; i++)
398 INIT_LIST_HEAD(&t->iphash[i]);
399#ifdef CONFIG_PROC_FS
400 uid = make_kuid(&init_user_ns, ip_list_uid);
401 gid = make_kgid(&init_user_ns, ip_list_gid);
402 if (!uid_valid(uid) || !gid_valid(gid)) {
403 recent_table_free(t);
404 ret = -EINVAL;
405 goto out;
406 }
407 pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
408 &recent_mt_proc_ops, t);
409 if (pde == NULL) {
410 recent_table_free(t);
411 ret = -ENOMEM;
412 goto out;
413 }
414 proc_set_user(pde, uid, gid);
415#endif
416 spin_lock_bh(&recent_lock);
417 list_add_tail(&t->list, &recent_net->tables);
418 spin_unlock_bh(&recent_lock);
419 ret = 0;
420out:
421 mutex_unlock(&recent_mutex);
422 return ret;
423}
424
425static int recent_mt_check_v0(const struct xt_mtchk_param *par)
426{
427 const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo;
428 struct xt_recent_mtinfo_v1 info_v1;
429
430
431 memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo));
432
433 memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all));
434
435 return recent_mt_check(par, &info_v1);
436}
437
438static int recent_mt_check_v1(const struct xt_mtchk_param *par)
439{
440 return recent_mt_check(par, par->matchinfo);
441}
442
443static void recent_mt_destroy(const struct xt_mtdtor_param *par)
444{
445 struct recent_net *recent_net = recent_pernet(par->net);
446 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
447 struct recent_table *t;
448
449 mutex_lock(&recent_mutex);
450 t = recent_table_lookup(recent_net, info->name);
451 if (--t->refcnt == 0) {
452 spin_lock_bh(&recent_lock);
453 list_del(&t->list);
454 spin_unlock_bh(&recent_lock);
455#ifdef CONFIG_PROC_FS
456 if (recent_net->xt_recent != NULL)
457 remove_proc_entry(t->name, recent_net->xt_recent);
458#endif
459 recent_table_flush(t);
460 recent_table_free(t);
461 }
462 mutex_unlock(&recent_mutex);
463}
464
465#ifdef CONFIG_PROC_FS
466struct recent_iter_state {
467 const struct recent_table *table;
468 unsigned int bucket;
469};
470
471static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
472 __acquires(recent_lock)
473{
474 struct recent_iter_state *st = seq->private;
475 const struct recent_table *t = st->table;
476 struct recent_entry *e;
477 loff_t p = *pos;
478
479 spin_lock_bh(&recent_lock);
480
481 for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
482 list_for_each_entry(e, &t->iphash[st->bucket], list)
483 if (p-- == 0)
484 return e;
485 return NULL;
486}
487
488static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
489{
490 struct recent_iter_state *st = seq->private;
491 const struct recent_table *t = st->table;
492 const struct recent_entry *e = v;
493 const struct list_head *head = e->list.next;
494
495 (*pos)++;
496 while (head == &t->iphash[st->bucket]) {
497 if (++st->bucket >= ip_list_hash_size)
498 return NULL;
499 head = t->iphash[st->bucket].next;
500 }
501 return list_entry(head, struct recent_entry, list);
502}
503
504static void recent_seq_stop(struct seq_file *s, void *v)
505 __releases(recent_lock)
506{
507 spin_unlock_bh(&recent_lock);
508}
509
510static int recent_seq_show(struct seq_file *seq, void *v)
511{
512 const struct recent_entry *e = v;
513 struct recent_iter_state *st = seq->private;
514 const struct recent_table *t = st->table;
515 unsigned int i;
516
517 i = (e->index - 1) & t->nstamps_max_mask;
518
519 if (e->family == NFPROTO_IPV4)
520 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
521 &e->addr.ip, e->ttl, e->stamps[i], e->index);
522 else
523 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
524 &e->addr.in6, e->ttl, e->stamps[i], e->index);
525 for (i = 0; i < e->nstamps; i++)
526 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
527 seq_putc(seq, '\n');
528 return 0;
529}
530
531static const struct seq_operations recent_seq_ops = {
532 .start = recent_seq_start,
533 .next = recent_seq_next,
534 .stop = recent_seq_stop,
535 .show = recent_seq_show,
536};
537
538static int recent_seq_open(struct inode *inode, struct file *file)
539{
540 struct recent_iter_state *st;
541
542 st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
543 if (st == NULL)
544 return -ENOMEM;
545
546 st->table = PDE_DATA(inode);
547 return 0;
548}
549
550static ssize_t
551recent_mt_proc_write(struct file *file, const char __user *input,
552 size_t size, loff_t *loff)
553{
554 struct recent_table *t = PDE_DATA(file_inode(file));
555 struct recent_entry *e;
556 char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
557 const char *c = buf;
558 union nf_inet_addr addr = {};
559 u_int16_t family;
560 bool add, succ;
561
562 if (size == 0)
563 return 0;
564 if (size > sizeof(buf))
565 size = sizeof(buf);
566 if (copy_from_user(buf, input, size) != 0)
567 return -EFAULT;
568
569
570 if (*loff != 0)
571 return -ESPIPE;
572 switch (*c) {
573 case '/':
574 spin_lock_bh(&recent_lock);
575 recent_table_flush(t);
576 spin_unlock_bh(&recent_lock);
577 return size;
578 case '-':
579 add = false;
580 break;
581 case '+':
582 add = true;
583 break;
584 default:
585 pr_info_ratelimited("Need \"+ip\", \"-ip\" or \"/\"\n");
586 return -EINVAL;
587 }
588
589 ++c;
590 --size;
591 if (strnchr(c, size, ':') != NULL) {
592 family = NFPROTO_IPV6;
593 succ = in6_pton(c, size, (void *)&addr, '\n', NULL);
594 } else {
595 family = NFPROTO_IPV4;
596 succ = in4_pton(c, size, (void *)&addr, '\n', NULL);
597 }
598
599 if (!succ)
600 return -EINVAL;
601
602 spin_lock_bh(&recent_lock);
603 e = recent_entry_lookup(t, &addr, family, 0);
604 if (e == NULL) {
605 if (add)
606 recent_entry_init(t, &addr, family, 0);
607 } else {
608 if (add)
609 recent_entry_update(t, e);
610 else
611 recent_entry_remove(t, e);
612 }
613 spin_unlock_bh(&recent_lock);
614
615 *loff += size + 1;
616 return size + 1;
617}
618
619static const struct proc_ops recent_mt_proc_ops = {
620 .proc_open = recent_seq_open,
621 .proc_read = seq_read,
622 .proc_write = recent_mt_proc_write,
623 .proc_release = seq_release_private,
624 .proc_lseek = seq_lseek,
625};
626
627static int __net_init recent_proc_net_init(struct net *net)
628{
629 struct recent_net *recent_net = recent_pernet(net);
630
631 recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
632 if (!recent_net->xt_recent)
633 return -ENOMEM;
634 return 0;
635}
636
637static void __net_exit recent_proc_net_exit(struct net *net)
638{
639 struct recent_net *recent_net = recent_pernet(net);
640 struct recent_table *t;
641
642
643
644
645
646 spin_lock_bh(&recent_lock);
647 list_for_each_entry(t, &recent_net->tables, list)
648 remove_proc_entry(t->name, recent_net->xt_recent);
649
650 recent_net->xt_recent = NULL;
651 spin_unlock_bh(&recent_lock);
652
653 remove_proc_entry("xt_recent", net->proc_net);
654}
655#else
656static inline int recent_proc_net_init(struct net *net)
657{
658 return 0;
659}
660
661static inline void recent_proc_net_exit(struct net *net)
662{
663}
664#endif
665
666static int __net_init recent_net_init(struct net *net)
667{
668 struct recent_net *recent_net = recent_pernet(net);
669
670 INIT_LIST_HEAD(&recent_net->tables);
671 return recent_proc_net_init(net);
672}
673
674static void __net_exit recent_net_exit(struct net *net)
675{
676 recent_proc_net_exit(net);
677}
678
679static struct pernet_operations recent_net_ops = {
680 .init = recent_net_init,
681 .exit = recent_net_exit,
682 .id = &recent_net_id,
683 .size = sizeof(struct recent_net),
684};
685
686static struct xt_match recent_mt_reg[] __read_mostly = {
687 {
688 .name = "recent",
689 .revision = 0,
690 .family = NFPROTO_IPV4,
691 .match = recent_mt,
692 .matchsize = sizeof(struct xt_recent_mtinfo),
693 .checkentry = recent_mt_check_v0,
694 .destroy = recent_mt_destroy,
695 .me = THIS_MODULE,
696 },
697 {
698 .name = "recent",
699 .revision = 0,
700 .family = NFPROTO_IPV6,
701 .match = recent_mt,
702 .matchsize = sizeof(struct xt_recent_mtinfo),
703 .checkentry = recent_mt_check_v0,
704 .destroy = recent_mt_destroy,
705 .me = THIS_MODULE,
706 },
707 {
708 .name = "recent",
709 .revision = 1,
710 .family = NFPROTO_IPV4,
711 .match = recent_mt,
712 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
713 .checkentry = recent_mt_check_v1,
714 .destroy = recent_mt_destroy,
715 .me = THIS_MODULE,
716 },
717 {
718 .name = "recent",
719 .revision = 1,
720 .family = NFPROTO_IPV6,
721 .match = recent_mt,
722 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
723 .checkentry = recent_mt_check_v1,
724 .destroy = recent_mt_destroy,
725 .me = THIS_MODULE,
726 }
727};
728
729static int __init recent_mt_init(void)
730{
731 int err;
732
733 BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
734
735 if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
736 return -EINVAL;
737 ip_list_hash_size = 1 << fls(ip_list_tot);
738
739 err = register_pernet_subsys(&recent_net_ops);
740 if (err)
741 return err;
742 err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
743 if (err)
744 unregister_pernet_subsys(&recent_net_ops);
745 return err;
746}
747
748static void __exit recent_mt_exit(void)
749{
750 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
751 unregister_pernet_subsys(&recent_net_ops);
752}
753
754module_init(recent_mt_init);
755module_exit(recent_mt_exit);
756
