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15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16#include <linux/init.h>
17#include <linux/ip.h>
18#include <linux/ipv6.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/string.h>
24#include <linux/ctype.h>
25#include <linux/list.h>
26#include <linux/random.h>
27#include <linux/jhash.h>
28#include <linux/bitops.h>
29#include <linux/skbuff.h>
30#include <linux/inet.h>
31#include <linux/slab.h>
32#include <linux/vmalloc.h>
33#include <net/net_namespace.h>
34#include <net/netns/generic.h>
35
36#include <linux/netfilter/x_tables.h>
37#include <linux/netfilter/xt_recent.h>
38
39MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
40MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
41MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
42MODULE_LICENSE("GPL");
43MODULE_ALIAS("ipt_recent");
44MODULE_ALIAS("ip6t_recent");
45
46static unsigned int ip_list_tot __read_mostly = 100;
47static unsigned int ip_list_hash_size __read_mostly;
48static unsigned int ip_list_perms __read_mostly = 0644;
49static unsigned int ip_list_uid __read_mostly;
50static unsigned int ip_list_gid __read_mostly;
51module_param(ip_list_tot, uint, 0400);
52module_param(ip_list_hash_size, uint, 0400);
53module_param(ip_list_perms, uint, 0400);
54module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
55module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
56MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
57MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
58MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
59MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
60MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
61
62
63static unsigned int ip_pkt_list_tot __read_mostly;
64module_param(ip_pkt_list_tot, uint, 0400);
65MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
66
67#define XT_RECENT_MAX_NSTAMPS 256
68
69struct recent_entry {
70 struct list_head list;
71 struct list_head lru_list;
72 union nf_inet_addr addr;
73 u_int16_t family;
74 u_int8_t ttl;
75 u_int8_t index;
76 u_int16_t nstamps;
77 unsigned long stamps[0];
78};
79
80struct recent_table {
81 struct list_head list;
82 char name[XT_RECENT_NAME_LEN];
83 union nf_inet_addr mask;
84 unsigned int refcnt;
85 unsigned int entries;
86 u8 nstamps_max_mask;
87 struct list_head lru_list;
88 struct list_head iphash[0];
89};
90
91struct recent_net {
92 struct list_head tables;
93#ifdef CONFIG_PROC_FS
94 struct proc_dir_entry *xt_recent;
95#endif
96};
97
98static unsigned int recent_net_id __read_mostly;
99
100static inline struct recent_net *recent_pernet(struct net *net)
101{
102 return net_generic(net, recent_net_id);
103}
104
105static DEFINE_SPINLOCK(recent_lock);
106static DEFINE_MUTEX(recent_mutex);
107
108#ifdef CONFIG_PROC_FS
109static const struct file_operations recent_old_fops, recent_mt_fops;
110#endif
111
112static u_int32_t hash_rnd __read_mostly;
113
114static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
115{
116 return jhash_1word((__force u32)addr->ip, hash_rnd) &
117 (ip_list_hash_size - 1);
118}
119
120static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
121{
122 return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
123 (ip_list_hash_size - 1);
124}
125
126static struct recent_entry *
127recent_entry_lookup(const struct recent_table *table,
128 const union nf_inet_addr *addrp, u_int16_t family,
129 u_int8_t ttl)
130{
131 struct recent_entry *e;
132 unsigned int h;
133
134 if (family == NFPROTO_IPV4)
135 h = recent_entry_hash4(addrp);
136 else
137 h = recent_entry_hash6(addrp);
138
139 list_for_each_entry(e, &table->iphash[h], list)
140 if (e->family == family &&
141 memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
142 (ttl == e->ttl || ttl == 0 || e->ttl == 0))
143 return e;
144 return NULL;
145}
146
147static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
148{
149 list_del(&e->list);
150 list_del(&e->lru_list);
151 kfree(e);
152 t->entries--;
153}
154
155
156
157
158static void recent_entry_reap(struct recent_table *t, unsigned long time)
159{
160 struct recent_entry *e;
161
162
163
164
165 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
166
167
168
169
170 if (time_after(time, e->stamps[e->index-1]))
171 recent_entry_remove(t, e);
172}
173
174static struct recent_entry *
175recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
176 u_int16_t family, u_int8_t ttl)
177{
178 struct recent_entry *e;
179 unsigned int nstamps_max = t->nstamps_max_mask;
180
181 if (t->entries >= ip_list_tot) {
182 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
183 recent_entry_remove(t, e);
184 }
185
186 nstamps_max += 1;
187 e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * nstamps_max,
188 GFP_ATOMIC);
189 if (e == NULL)
190 return NULL;
191 memcpy(&e->addr, addr, sizeof(e->addr));
192 e->ttl = ttl;
193 e->stamps[0] = jiffies;
194 e->nstamps = 1;
195 e->index = 1;
196 e->family = family;
197 if (family == NFPROTO_IPV4)
198 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
199 else
200 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
201 list_add_tail(&e->lru_list, &t->lru_list);
202 t->entries++;
203 return e;
204}
205
206static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
207{
208 e->index &= t->nstamps_max_mask;
209 e->stamps[e->index++] = jiffies;
210 if (e->index > e->nstamps)
211 e->nstamps = e->index;
212 list_move_tail(&e->lru_list, &t->lru_list);
213}
214
215static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
216 const char *name)
217{
218 struct recent_table *t;
219
220 list_for_each_entry(t, &recent_net->tables, list)
221 if (!strcmp(t->name, name))
222 return t;
223 return NULL;
224}
225
226static void recent_table_flush(struct recent_table *t)
227{
228 struct recent_entry *e, *next;
229 unsigned int i;
230
231 for (i = 0; i < ip_list_hash_size; i++)
232 list_for_each_entry_safe(e, next, &t->iphash[i], list)
233 recent_entry_remove(t, e);
234}
235
236static bool
237recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
238{
239 struct net *net = xt_net(par);
240 struct recent_net *recent_net = recent_pernet(net);
241 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
242 struct recent_table *t;
243 struct recent_entry *e;
244 union nf_inet_addr addr = {}, addr_mask;
245 u_int8_t ttl;
246 bool ret = info->invert;
247
248 if (xt_family(par) == NFPROTO_IPV4) {
249 const struct iphdr *iph = ip_hdr(skb);
250
251 if (info->side == XT_RECENT_DEST)
252 addr.ip = iph->daddr;
253 else
254 addr.ip = iph->saddr;
255
256 ttl = iph->ttl;
257 } else {
258 const struct ipv6hdr *iph = ipv6_hdr(skb);
259
260 if (info->side == XT_RECENT_DEST)
261 memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
262 else
263 memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
264
265 ttl = iph->hop_limit;
266 }
267
268
269 if (xt_out(par) != NULL && skb->sk == NULL)
270 ttl++;
271
272 spin_lock_bh(&recent_lock);
273 t = recent_table_lookup(recent_net, info->name);
274
275 nf_inet_addr_mask(&addr, &addr_mask, &t->mask);
276
277 e = recent_entry_lookup(t, &addr_mask, xt_family(par),
278 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
279 if (e == NULL) {
280 if (!(info->check_set & XT_RECENT_SET))
281 goto out;
282 e = recent_entry_init(t, &addr_mask, xt_family(par), ttl);
283 if (e == NULL)
284 par->hotdrop = true;
285 ret = !ret;
286 goto out;
287 }
288
289 if (info->check_set & XT_RECENT_SET)
290 ret = !ret;
291 else if (info->check_set & XT_RECENT_REMOVE) {
292 recent_entry_remove(t, e);
293 ret = !ret;
294 } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
295 unsigned long time = jiffies - info->seconds * HZ;
296 unsigned int i, hits = 0;
297
298 for (i = 0; i < e->nstamps; i++) {
299 if (info->seconds && time_after(time, e->stamps[i]))
300 continue;
301 if (!info->hit_count || ++hits >= info->hit_count) {
302 ret = !ret;
303 break;
304 }
305 }
306
307
308 if (info->check_set & XT_RECENT_REAP)
309 recent_entry_reap(t, time);
310 }
311
312 if (info->check_set & XT_RECENT_SET ||
313 (info->check_set & XT_RECENT_UPDATE && ret)) {
314 recent_entry_update(t, e);
315 e->ttl = ttl;
316 }
317out:
318 spin_unlock_bh(&recent_lock);
319 return ret;
320}
321
322static void recent_table_free(void *addr)
323{
324 kvfree(addr);
325}
326
327static int recent_mt_check(const struct xt_mtchk_param *par,
328 const struct xt_recent_mtinfo_v1 *info)
329{
330 struct recent_net *recent_net = recent_pernet(par->net);
331 struct recent_table *t;
332#ifdef CONFIG_PROC_FS
333 struct proc_dir_entry *pde;
334 kuid_t uid;
335 kgid_t gid;
336#endif
337 unsigned int nstamp_mask;
338 unsigned int i;
339 int ret = -EINVAL;
340 size_t sz;
341
342 net_get_random_once(&hash_rnd, sizeof(hash_rnd));
343
344 if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
345 pr_info("Unsupported user space flags (%08x)\n",
346 info->check_set);
347 return -EINVAL;
348 }
349 if (hweight8(info->check_set &
350 (XT_RECENT_SET | XT_RECENT_REMOVE |
351 XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
352 return -EINVAL;
353 if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
354 (info->seconds || info->hit_count ||
355 (info->check_set & XT_RECENT_MODIFIERS)))
356 return -EINVAL;
357 if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
358 return -EINVAL;
359 if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) {
360 pr_info("hitcount (%u) is larger than allowed maximum (%u)\n",
361 info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
362 return -EINVAL;
363 }
364 if (info->name[0] == '\0' ||
365 strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
366 return -EINVAL;
367
368 if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
369 nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
370 else if (info->hit_count)
371 nstamp_mask = roundup_pow_of_two(info->hit_count) - 1;
372 else
373 nstamp_mask = 32 - 1;
374
375 mutex_lock(&recent_mutex);
376 t = recent_table_lookup(recent_net, info->name);
377 if (t != NULL) {
378 if (nstamp_mask > t->nstamps_max_mask) {
379 spin_lock_bh(&recent_lock);
380 recent_table_flush(t);
381 t->nstamps_max_mask = nstamp_mask;
382 spin_unlock_bh(&recent_lock);
383 }
384
385 t->refcnt++;
386 ret = 0;
387 goto out;
388 }
389
390 sz = sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size;
391 if (sz <= PAGE_SIZE)
392 t = kzalloc(sz, GFP_KERNEL);
393 else
394 t = vzalloc(sz);
395 if (t == NULL) {
396 ret = -ENOMEM;
397 goto out;
398 }
399 t->refcnt = 1;
400 t->nstamps_max_mask = nstamp_mask;
401
402 memcpy(&t->mask, &info->mask, sizeof(t->mask));
403 strcpy(t->name, info->name);
404 INIT_LIST_HEAD(&t->lru_list);
405 for (i = 0; i < ip_list_hash_size; i++)
406 INIT_LIST_HEAD(&t->iphash[i]);
407#ifdef CONFIG_PROC_FS
408 uid = make_kuid(&init_user_ns, ip_list_uid);
409 gid = make_kgid(&init_user_ns, ip_list_gid);
410 if (!uid_valid(uid) || !gid_valid(gid)) {
411 recent_table_free(t);
412 ret = -EINVAL;
413 goto out;
414 }
415 pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
416 &recent_mt_fops, t);
417 if (pde == NULL) {
418 recent_table_free(t);
419 ret = -ENOMEM;
420 goto out;
421 }
422 proc_set_user(pde, uid, gid);
423#endif
424 spin_lock_bh(&recent_lock);
425 list_add_tail(&t->list, &recent_net->tables);
426 spin_unlock_bh(&recent_lock);
427 ret = 0;
428out:
429 mutex_unlock(&recent_mutex);
430 return ret;
431}
432
433static int recent_mt_check_v0(const struct xt_mtchk_param *par)
434{
435 const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo;
436 struct xt_recent_mtinfo_v1 info_v1;
437
438
439 memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo));
440
441 memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all));
442
443 return recent_mt_check(par, &info_v1);
444}
445
446static int recent_mt_check_v1(const struct xt_mtchk_param *par)
447{
448 return recent_mt_check(par, par->matchinfo);
449}
450
451static void recent_mt_destroy(const struct xt_mtdtor_param *par)
452{
453 struct recent_net *recent_net = recent_pernet(par->net);
454 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
455 struct recent_table *t;
456
457 mutex_lock(&recent_mutex);
458 t = recent_table_lookup(recent_net, info->name);
459 if (--t->refcnt == 0) {
460 spin_lock_bh(&recent_lock);
461 list_del(&t->list);
462 spin_unlock_bh(&recent_lock);
463#ifdef CONFIG_PROC_FS
464 if (recent_net->xt_recent != NULL)
465 remove_proc_entry(t->name, recent_net->xt_recent);
466#endif
467 recent_table_flush(t);
468 recent_table_free(t);
469 }
470 mutex_unlock(&recent_mutex);
471}
472
473#ifdef CONFIG_PROC_FS
474struct recent_iter_state {
475 const struct recent_table *table;
476 unsigned int bucket;
477};
478
479static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
480 __acquires(recent_lock)
481{
482 struct recent_iter_state *st = seq->private;
483 const struct recent_table *t = st->table;
484 struct recent_entry *e;
485 loff_t p = *pos;
486
487 spin_lock_bh(&recent_lock);
488
489 for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
490 list_for_each_entry(e, &t->iphash[st->bucket], list)
491 if (p-- == 0)
492 return e;
493 return NULL;
494}
495
496static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
497{
498 struct recent_iter_state *st = seq->private;
499 const struct recent_table *t = st->table;
500 const struct recent_entry *e = v;
501 const struct list_head *head = e->list.next;
502
503 while (head == &t->iphash[st->bucket]) {
504 if (++st->bucket >= ip_list_hash_size)
505 return NULL;
506 head = t->iphash[st->bucket].next;
507 }
508 (*pos)++;
509 return list_entry(head, struct recent_entry, list);
510}
511
512static void recent_seq_stop(struct seq_file *s, void *v)
513 __releases(recent_lock)
514{
515 spin_unlock_bh(&recent_lock);
516}
517
518static int recent_seq_show(struct seq_file *seq, void *v)
519{
520 const struct recent_entry *e = v;
521 struct recent_iter_state *st = seq->private;
522 const struct recent_table *t = st->table;
523 unsigned int i;
524
525 i = (e->index - 1) & t->nstamps_max_mask;
526
527 if (e->family == NFPROTO_IPV4)
528 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
529 &e->addr.ip, e->ttl, e->stamps[i], e->index);
530 else
531 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
532 &e->addr.in6, e->ttl, e->stamps[i], e->index);
533 for (i = 0; i < e->nstamps; i++)
534 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
535 seq_printf(seq, "\n");
536 return 0;
537}
538
539static const struct seq_operations recent_seq_ops = {
540 .start = recent_seq_start,
541 .next = recent_seq_next,
542 .stop = recent_seq_stop,
543 .show = recent_seq_show,
544};
545
546static int recent_seq_open(struct inode *inode, struct file *file)
547{
548 struct recent_iter_state *st;
549
550 st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
551 if (st == NULL)
552 return -ENOMEM;
553
554 st->table = PDE_DATA(inode);
555 return 0;
556}
557
558static ssize_t
559recent_mt_proc_write(struct file *file, const char __user *input,
560 size_t size, loff_t *loff)
561{
562 struct recent_table *t = PDE_DATA(file_inode(file));
563 struct recent_entry *e;
564 char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
565 const char *c = buf;
566 union nf_inet_addr addr = {};
567 u_int16_t family;
568 bool add, succ;
569
570 if (size == 0)
571 return 0;
572 if (size > sizeof(buf))
573 size = sizeof(buf);
574 if (copy_from_user(buf, input, size) != 0)
575 return -EFAULT;
576
577
578 if (*loff != 0)
579 return -ESPIPE;
580 switch (*c) {
581 case '/':
582 spin_lock_bh(&recent_lock);
583 recent_table_flush(t);
584 spin_unlock_bh(&recent_lock);
585 return size;
586 case '-':
587 add = false;
588 break;
589 case '+':
590 add = true;
591 break;
592 default:
593 pr_info("Need \"+ip\", \"-ip\" or \"/\"\n");
594 return -EINVAL;
595 }
596
597 ++c;
598 --size;
599 if (strnchr(c, size, ':') != NULL) {
600 family = NFPROTO_IPV6;
601 succ = in6_pton(c, size, (void *)&addr, '\n', NULL);
602 } else {
603 family = NFPROTO_IPV4;
604 succ = in4_pton(c, size, (void *)&addr, '\n', NULL);
605 }
606
607 if (!succ) {
608 pr_info("illegal address written to procfs\n");
609 return -EINVAL;
610 }
611
612 spin_lock_bh(&recent_lock);
613 e = recent_entry_lookup(t, &addr, family, 0);
614 if (e == NULL) {
615 if (add)
616 recent_entry_init(t, &addr, family, 0);
617 } else {
618 if (add)
619 recent_entry_update(t, e);
620 else
621 recent_entry_remove(t, e);
622 }
623 spin_unlock_bh(&recent_lock);
624
625 *loff += size + 1;
626 return size + 1;
627}
628
629static const struct file_operations recent_mt_fops = {
630 .open = recent_seq_open,
631 .read = seq_read,
632 .write = recent_mt_proc_write,
633 .release = seq_release_private,
634 .owner = THIS_MODULE,
635 .llseek = seq_lseek,
636};
637
638static int __net_init recent_proc_net_init(struct net *net)
639{
640 struct recent_net *recent_net = recent_pernet(net);
641
642 recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
643 if (!recent_net->xt_recent)
644 return -ENOMEM;
645 return 0;
646}
647
648static void __net_exit recent_proc_net_exit(struct net *net)
649{
650 struct recent_net *recent_net = recent_pernet(net);
651 struct recent_table *t;
652
653
654
655
656
657 spin_lock_bh(&recent_lock);
658 list_for_each_entry(t, &recent_net->tables, list)
659 remove_proc_entry(t->name, recent_net->xt_recent);
660
661 recent_net->xt_recent = NULL;
662 spin_unlock_bh(&recent_lock);
663
664 remove_proc_entry("xt_recent", net->proc_net);
665}
666#else
667static inline int recent_proc_net_init(struct net *net)
668{
669 return 0;
670}
671
672static inline void recent_proc_net_exit(struct net *net)
673{
674}
675#endif
676
677static int __net_init recent_net_init(struct net *net)
678{
679 struct recent_net *recent_net = recent_pernet(net);
680
681 INIT_LIST_HEAD(&recent_net->tables);
682 return recent_proc_net_init(net);
683}
684
685static void __net_exit recent_net_exit(struct net *net)
686{
687 recent_proc_net_exit(net);
688}
689
690static struct pernet_operations recent_net_ops = {
691 .init = recent_net_init,
692 .exit = recent_net_exit,
693 .id = &recent_net_id,
694 .size = sizeof(struct recent_net),
695};
696
697static struct xt_match recent_mt_reg[] __read_mostly = {
698 {
699 .name = "recent",
700 .revision = 0,
701 .family = NFPROTO_IPV4,
702 .match = recent_mt,
703 .matchsize = sizeof(struct xt_recent_mtinfo),
704 .checkentry = recent_mt_check_v0,
705 .destroy = recent_mt_destroy,
706 .me = THIS_MODULE,
707 },
708 {
709 .name = "recent",
710 .revision = 0,
711 .family = NFPROTO_IPV6,
712 .match = recent_mt,
713 .matchsize = sizeof(struct xt_recent_mtinfo),
714 .checkentry = recent_mt_check_v0,
715 .destroy = recent_mt_destroy,
716 .me = THIS_MODULE,
717 },
718 {
719 .name = "recent",
720 .revision = 1,
721 .family = NFPROTO_IPV4,
722 .match = recent_mt,
723 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
724 .checkentry = recent_mt_check_v1,
725 .destroy = recent_mt_destroy,
726 .me = THIS_MODULE,
727 },
728 {
729 .name = "recent",
730 .revision = 1,
731 .family = NFPROTO_IPV6,
732 .match = recent_mt,
733 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
734 .checkentry = recent_mt_check_v1,
735 .destroy = recent_mt_destroy,
736 .me = THIS_MODULE,
737 }
738};
739
740static int __init recent_mt_init(void)
741{
742 int err;
743
744 BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
745
746 if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
747 return -EINVAL;
748 ip_list_hash_size = 1 << fls(ip_list_tot);
749
750 err = register_pernet_subsys(&recent_net_ops);
751 if (err)
752 return err;
753 err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
754 if (err)
755 unregister_pernet_subsys(&recent_net_ops);
756 return err;
757}
758
759static void __exit recent_mt_exit(void)
760{
761 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
762 unregister_pernet_subsys(&recent_net_ops);
763}
764
765module_init(recent_mt_init);
766module_exit(recent_mt_exit);
767
