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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
4 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
5 *
6 * This is a replacement of the old ipt_recent module, which carried the
7 * following copyright notice:
8 *
9 * Author: Stephen Frost <sfrost@snowman.net>
10 * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
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/* retained for backwards compatibility */
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 * Drop entries with timestamps older then 'time'.
154 */
155static void recent_entry_reap(struct recent_table *t, unsigned long time,
156 struct recent_entry *working, bool update)
157{
158 struct recent_entry *e;
159
160 /*
161 * The head of the LRU list is always the oldest entry.
162 */
163 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
164
165 /*
166 * Do not reap the entry which are going to be updated.
167 */
168 if (e == working && update)
169 return;
170
171 /*
172 * The last time stamp is the most recent.
173 */
174 if (time_after(time, e->stamps[e->index-1]))
175 recent_entry_remove(t, e);
176}
177
178static struct recent_entry *
179recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
180 u_int16_t family, u_int8_t ttl)
181{
182 struct recent_entry *e;
183 unsigned int nstamps_max = t->nstamps_max_mask;
184
185 if (t->entries >= ip_list_tot) {
186 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
187 recent_entry_remove(t, e);
188 }
189
190 nstamps_max += 1;
191 e = kmalloc(struct_size(e, stamps, nstamps_max), GFP_ATOMIC);
192 if (e == NULL)
193 return NULL;
194 memcpy(&e->addr, addr, sizeof(e->addr));
195 e->ttl = ttl;
196 e->stamps[0] = jiffies;
197 e->nstamps = 1;
198 e->index = 1;
199 e->family = family;
200 if (family == NFPROTO_IPV4)
201 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
202 else
203 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
204 list_add_tail(&e->lru_list, &t->lru_list);
205 t->entries++;
206 return e;
207}
208
209static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
210{
211 e->index &= t->nstamps_max_mask;
212 e->stamps[e->index++] = jiffies;
213 if (e->index > e->nstamps)
214 e->nstamps = e->index;
215 list_move_tail(&e->lru_list, &t->lru_list);
216}
217
218static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
219 const char *name)
220{
221 struct recent_table *t;
222
223 list_for_each_entry(t, &recent_net->tables, list)
224 if (!strcmp(t->name, name))
225 return t;
226 return NULL;
227}
228
229static void recent_table_flush(struct recent_table *t)
230{
231 struct recent_entry *e, *next;
232 unsigned int i;
233
234 for (i = 0; i < ip_list_hash_size; i++)
235 list_for_each_entry_safe(e, next, &t->iphash[i], list)
236 recent_entry_remove(t, e);
237}
238
239static bool
240recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
241{
242 struct net *net = xt_net(par);
243 struct recent_net *recent_net = recent_pernet(net);
244 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
245 struct recent_table *t;
246 struct recent_entry *e;
247 union nf_inet_addr addr = {}, addr_mask;
248 u_int8_t ttl;
249 bool ret = info->invert;
250
251 if (xt_family(par) == NFPROTO_IPV4) {
252 const struct iphdr *iph = ip_hdr(skb);
253
254 if (info->side == XT_RECENT_DEST)
255 addr.ip = iph->daddr;
256 else
257 addr.ip = iph->saddr;
258
259 ttl = iph->ttl;
260 } else {
261 const struct ipv6hdr *iph = ipv6_hdr(skb);
262
263 if (info->side == XT_RECENT_DEST)
264 memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
265 else
266 memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
267
268 ttl = iph->hop_limit;
269 }
270
271 /* use TTL as seen before forwarding */
272 if (xt_out(par) != NULL &&
273 (!skb->sk || !net_eq(net, sock_net(skb->sk))))
274 ttl++;
275
276 spin_lock_bh(&recent_lock);
277 t = recent_table_lookup(recent_net, info->name);
278
279 nf_inet_addr_mask(&addr, &addr_mask, &t->mask);
280
281 e = recent_entry_lookup(t, &addr_mask, xt_family(par),
282 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
283 if (e == NULL) {
284 if (!(info->check_set & XT_RECENT_SET))
285 goto out;
286 e = recent_entry_init(t, &addr_mask, xt_family(par), ttl);
287 if (e == NULL)
288 par->hotdrop = true;
289 ret = !ret;
290 goto out;
291 }
292
293 if (info->check_set & XT_RECENT_SET)
294 ret = !ret;
295 else if (info->check_set & XT_RECENT_REMOVE) {
296 recent_entry_remove(t, e);
297 ret = !ret;
298 } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
299 unsigned long time = jiffies - info->seconds * HZ;
300 unsigned int i, hits = 0;
301
302 for (i = 0; i < e->nstamps; i++) {
303 if (info->seconds && time_after(time, e->stamps[i]))
304 continue;
305 if (!info->hit_count || ++hits >= info->hit_count) {
306 ret = !ret;
307 break;
308 }
309 }
310
311 /* info->seconds must be non-zero */
312 if (info->check_set & XT_RECENT_REAP)
313 recent_entry_reap(t, time, e,
314 info->check_set & XT_RECENT_UPDATE && ret);
315 }
316
317 if (info->check_set & XT_RECENT_SET ||
318 (info->check_set & XT_RECENT_UPDATE && ret)) {
319 recent_entry_update(t, e);
320 e->ttl = ttl;
321 }
322out:
323 spin_unlock_bh(&recent_lock);
324 return ret;
325}
326
327static void recent_table_free(void *addr)
328{
329 kvfree(addr);
330}
331
332static int recent_mt_check(const struct xt_mtchk_param *par,
333 const struct xt_recent_mtinfo_v1 *info)
334{
335 struct recent_net *recent_net = recent_pernet(par->net);
336 struct recent_table *t;
337#ifdef CONFIG_PROC_FS
338 struct proc_dir_entry *pde;
339 kuid_t uid;
340 kgid_t gid;
341#endif
342 unsigned int nstamp_mask;
343 unsigned int i;
344 int ret = -EINVAL;
345
346 net_get_random_once(&hash_rnd, sizeof(hash_rnd));
347
348 if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
349 pr_info_ratelimited("Unsupported userspace flags (%08x)\n",
350 info->check_set);
351 return -EINVAL;
352 }
353 if (hweight8(info->check_set &
354 (XT_RECENT_SET | XT_RECENT_REMOVE |
355 XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
356 return -EINVAL;
357 if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
358 (info->seconds || info->hit_count ||
359 (info->check_set & XT_RECENT_MODIFIERS)))
360 return -EINVAL;
361 if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
362 return -EINVAL;
363 if (info->hit_count >= XT_RECENT_MAX_NSTAMPS) {
364 pr_info_ratelimited("hitcount (%u) is larger than allowed maximum (%u)\n",
365 info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
366 return -EINVAL;
367 }
368 ret = xt_check_proc_name(info->name, sizeof(info->name));
369 if (ret)
370 return ret;
371
372 if (ip_pkt_list_tot && info->hit_count < ip_pkt_list_tot)
373 nstamp_mask = roundup_pow_of_two(ip_pkt_list_tot) - 1;
374 else if (info->hit_count)
375 nstamp_mask = roundup_pow_of_two(info->hit_count) - 1;
376 else
377 nstamp_mask = 32 - 1;
378
379 mutex_lock(&recent_mutex);
380 t = recent_table_lookup(recent_net, info->name);
381 if (t != NULL) {
382 if (nstamp_mask > t->nstamps_max_mask) {
383 spin_lock_bh(&recent_lock);
384 recent_table_flush(t);
385 t->nstamps_max_mask = nstamp_mask;
386 spin_unlock_bh(&recent_lock);
387 }
388
389 t->refcnt++;
390 ret = 0;
391 goto out;
392 }
393
394 t = kvzalloc(struct_size(t, iphash, ip_list_hash_size), GFP_KERNEL);
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_proc_ops, 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 /* Copy revision 0 structure to revision 1 */
439 memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo));
440 /* Set default mask to ensure backward compatible behaviour */
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 (*pos)++;
504 while (head == &t->iphash[st->bucket]) {
505 if (++st->bucket >= ip_list_hash_size)
506 return NULL;
507 head = t->iphash[st->bucket].next;
508 }
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_putc(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 /* Strict protocol! */
578 if (*loff != 0)
579 return -ESPIPE;
580 switch (*c) {
581 case '/': /* flush table */
582 spin_lock_bh(&recent_lock);
583 recent_table_flush(t);
584 spin_unlock_bh(&recent_lock);
585 return size;
586 case '-': /* remove address */
587 add = false;
588 break;
589 case '+': /* add address */
590 add = true;
591 break;
592 default:
593 pr_info_ratelimited("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 return -EINVAL;
609
610 spin_lock_bh(&recent_lock);
611 e = recent_entry_lookup(t, &addr, family, 0);
612 if (e == NULL) {
613 if (add)
614 recent_entry_init(t, &addr, family, 0);
615 } else {
616 if (add)
617 recent_entry_update(t, e);
618 else
619 recent_entry_remove(t, e);
620 }
621 spin_unlock_bh(&recent_lock);
622 /* Note we removed one above */
623 *loff += size + 1;
624 return size + 1;
625}
626
627static const struct proc_ops recent_mt_proc_ops = {
628 .proc_open = recent_seq_open,
629 .proc_read = seq_read,
630 .proc_write = recent_mt_proc_write,
631 .proc_release = seq_release_private,
632 .proc_lseek = seq_lseek,
633};
634
635static int __net_init recent_proc_net_init(struct net *net)
636{
637 struct recent_net *recent_net = recent_pernet(net);
638
639 recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
640 if (!recent_net->xt_recent)
641 return -ENOMEM;
642 return 0;
643}
644
645static void __net_exit recent_proc_net_exit(struct net *net)
646{
647 struct recent_net *recent_net = recent_pernet(net);
648 struct recent_table *t;
649
650 /* recent_net_exit() is called before recent_mt_destroy(). Make sure
651 * that the parent xt_recent proc entry is empty before trying to
652 * remove it.
653 */
654 spin_lock_bh(&recent_lock);
655 list_for_each_entry(t, &recent_net->tables, list)
656 remove_proc_entry(t->name, recent_net->xt_recent);
657
658 recent_net->xt_recent = NULL;
659 spin_unlock_bh(&recent_lock);
660
661 remove_proc_entry("xt_recent", net->proc_net);
662}
663#else
664static inline int recent_proc_net_init(struct net *net)
665{
666 return 0;
667}
668
669static inline void recent_proc_net_exit(struct net *net)
670{
671}
672#endif /* CONFIG_PROC_FS */
673
674static int __net_init recent_net_init(struct net *net)
675{
676 struct recent_net *recent_net = recent_pernet(net);
677
678 INIT_LIST_HEAD(&recent_net->tables);
679 return recent_proc_net_init(net);
680}
681
682static void __net_exit recent_net_exit(struct net *net)
683{
684 recent_proc_net_exit(net);
685}
686
687static struct pernet_operations recent_net_ops = {
688 .init = recent_net_init,
689 .exit = recent_net_exit,
690 .id = &recent_net_id,
691 .size = sizeof(struct recent_net),
692};
693
694static struct xt_match recent_mt_reg[] __read_mostly = {
695 {
696 .name = "recent",
697 .revision = 0,
698 .family = NFPROTO_IPV4,
699 .match = recent_mt,
700 .matchsize = sizeof(struct xt_recent_mtinfo),
701 .checkentry = recent_mt_check_v0,
702 .destroy = recent_mt_destroy,
703 .me = THIS_MODULE,
704 },
705 {
706 .name = "recent",
707 .revision = 0,
708 .family = NFPROTO_IPV6,
709 .match = recent_mt,
710 .matchsize = sizeof(struct xt_recent_mtinfo),
711 .checkentry = recent_mt_check_v0,
712 .destroy = recent_mt_destroy,
713 .me = THIS_MODULE,
714 },
715 {
716 .name = "recent",
717 .revision = 1,
718 .family = NFPROTO_IPV4,
719 .match = recent_mt,
720 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
721 .checkentry = recent_mt_check_v1,
722 .destroy = recent_mt_destroy,
723 .me = THIS_MODULE,
724 },
725 {
726 .name = "recent",
727 .revision = 1,
728 .family = NFPROTO_IPV6,
729 .match = recent_mt,
730 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
731 .checkentry = recent_mt_check_v1,
732 .destroy = recent_mt_destroy,
733 .me = THIS_MODULE,
734 }
735};
736
737static int __init recent_mt_init(void)
738{
739 int err;
740
741 BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
742
743 if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
744 return -EINVAL;
745 ip_list_hash_size = 1 << fls(ip_list_tot);
746
747 err = register_pernet_subsys(&recent_net_ops);
748 if (err)
749 return err;
750 err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
751 if (err)
752 unregister_pernet_subsys(&recent_net_ops);
753 return err;
754}
755
756static void __exit recent_mt_exit(void)
757{
758 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
759 unregister_pernet_subsys(&recent_net_ops);
760}
761
762module_init(recent_mt_init);
763module_exit(recent_mt_exit);
1/*
2 * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
3 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
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.
8 *
9 * This is a replacement of the old ipt_recent module, which carried the
10 * following copyright notice:
11 *
12 * Author: Stephen Frost <sfrost@snowman.net>
13 * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
14 */
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, 0644);
55module_param(ip_list_gid, uint, 0644);
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/* retained for backwards compatibility */
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_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 * Drop entries with timestamps older then 'time'.
157 */
158static void recent_entry_reap(struct recent_table *t, unsigned long time)
159{
160 struct recent_entry *e;
161
162 /*
163 * The head of the LRU list is always the oldest entry.
164 */
165 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
166
167 /*
168 * The last time stamp is the most recent.
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 /* use TTL as seen before forwarding */
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 /* info->seconds must be non-zero */
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_ratelimited("Unsupported userspace 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_ratelimited("hitcount (%u) is larger than allowed maximum (%u)\n",
361 info->hit_count, XT_RECENT_MAX_NSTAMPS - 1);
362 return -EINVAL;
363 }
364 ret = xt_check_proc_name(info->name, sizeof(info->name));
365 if (ret)
366 return ret;
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 t = kvzalloc(sz, GFP_KERNEL);
392 if (t == NULL) {
393 ret = -ENOMEM;
394 goto out;
395 }
396 t->refcnt = 1;
397 t->nstamps_max_mask = nstamp_mask;
398
399 memcpy(&t->mask, &info->mask, sizeof(t->mask));
400 strcpy(t->name, info->name);
401 INIT_LIST_HEAD(&t->lru_list);
402 for (i = 0; i < ip_list_hash_size; i++)
403 INIT_LIST_HEAD(&t->iphash[i]);
404#ifdef CONFIG_PROC_FS
405 uid = make_kuid(&init_user_ns, ip_list_uid);
406 gid = make_kgid(&init_user_ns, ip_list_gid);
407 if (!uid_valid(uid) || !gid_valid(gid)) {
408 recent_table_free(t);
409 ret = -EINVAL;
410 goto out;
411 }
412 pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
413 &recent_mt_fops, t);
414 if (pde == NULL) {
415 recent_table_free(t);
416 ret = -ENOMEM;
417 goto out;
418 }
419 proc_set_user(pde, uid, gid);
420#endif
421 spin_lock_bh(&recent_lock);
422 list_add_tail(&t->list, &recent_net->tables);
423 spin_unlock_bh(&recent_lock);
424 ret = 0;
425out:
426 mutex_unlock(&recent_mutex);
427 return ret;
428}
429
430static int recent_mt_check_v0(const struct xt_mtchk_param *par)
431{
432 const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo;
433 struct xt_recent_mtinfo_v1 info_v1;
434
435 /* Copy revision 0 structure to revision 1 */
436 memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo));
437 /* Set default mask to ensure backward compatible behaviour */
438 memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all));
439
440 return recent_mt_check(par, &info_v1);
441}
442
443static int recent_mt_check_v1(const struct xt_mtchk_param *par)
444{
445 return recent_mt_check(par, par->matchinfo);
446}
447
448static void recent_mt_destroy(const struct xt_mtdtor_param *par)
449{
450 struct recent_net *recent_net = recent_pernet(par->net);
451 const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
452 struct recent_table *t;
453
454 mutex_lock(&recent_mutex);
455 t = recent_table_lookup(recent_net, info->name);
456 if (--t->refcnt == 0) {
457 spin_lock_bh(&recent_lock);
458 list_del(&t->list);
459 spin_unlock_bh(&recent_lock);
460#ifdef CONFIG_PROC_FS
461 if (recent_net->xt_recent != NULL)
462 remove_proc_entry(t->name, recent_net->xt_recent);
463#endif
464 recent_table_flush(t);
465 recent_table_free(t);
466 }
467 mutex_unlock(&recent_mutex);
468}
469
470#ifdef CONFIG_PROC_FS
471struct recent_iter_state {
472 const struct recent_table *table;
473 unsigned int bucket;
474};
475
476static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
477 __acquires(recent_lock)
478{
479 struct recent_iter_state *st = seq->private;
480 const struct recent_table *t = st->table;
481 struct recent_entry *e;
482 loff_t p = *pos;
483
484 spin_lock_bh(&recent_lock);
485
486 for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
487 list_for_each_entry(e, &t->iphash[st->bucket], list)
488 if (p-- == 0)
489 return e;
490 return NULL;
491}
492
493static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
494{
495 struct recent_iter_state *st = seq->private;
496 const struct recent_table *t = st->table;
497 const struct recent_entry *e = v;
498 const struct list_head *head = e->list.next;
499
500 while (head == &t->iphash[st->bucket]) {
501 if (++st->bucket >= ip_list_hash_size)
502 return NULL;
503 head = t->iphash[st->bucket].next;
504 }
505 (*pos)++;
506 return list_entry(head, struct recent_entry, list);
507}
508
509static void recent_seq_stop(struct seq_file *s, void *v)
510 __releases(recent_lock)
511{
512 spin_unlock_bh(&recent_lock);
513}
514
515static int recent_seq_show(struct seq_file *seq, void *v)
516{
517 const struct recent_entry *e = v;
518 struct recent_iter_state *st = seq->private;
519 const struct recent_table *t = st->table;
520 unsigned int i;
521
522 i = (e->index - 1) & t->nstamps_max_mask;
523
524 if (e->family == NFPROTO_IPV4)
525 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
526 &e->addr.ip, e->ttl, e->stamps[i], e->index);
527 else
528 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
529 &e->addr.in6, e->ttl, e->stamps[i], e->index);
530 for (i = 0; i < e->nstamps; i++)
531 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
532 seq_putc(seq, '\n');
533 return 0;
534}
535
536static const struct seq_operations recent_seq_ops = {
537 .start = recent_seq_start,
538 .next = recent_seq_next,
539 .stop = recent_seq_stop,
540 .show = recent_seq_show,
541};
542
543static int recent_seq_open(struct inode *inode, struct file *file)
544{
545 struct recent_iter_state *st;
546
547 st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
548 if (st == NULL)
549 return -ENOMEM;
550
551 st->table = PDE_DATA(inode);
552 return 0;
553}
554
555static ssize_t
556recent_mt_proc_write(struct file *file, const char __user *input,
557 size_t size, loff_t *loff)
558{
559 struct recent_table *t = PDE_DATA(file_inode(file));
560 struct recent_entry *e;
561 char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
562 const char *c = buf;
563 union nf_inet_addr addr = {};
564 u_int16_t family;
565 bool add, succ;
566
567 if (size == 0)
568 return 0;
569 if (size > sizeof(buf))
570 size = sizeof(buf);
571 if (copy_from_user(buf, input, size) != 0)
572 return -EFAULT;
573
574 /* Strict protocol! */
575 if (*loff != 0)
576 return -ESPIPE;
577 switch (*c) {
578 case '/': /* flush table */
579 spin_lock_bh(&recent_lock);
580 recent_table_flush(t);
581 spin_unlock_bh(&recent_lock);
582 return size;
583 case '-': /* remove address */
584 add = false;
585 break;
586 case '+': /* add address */
587 add = true;
588 break;
589 default:
590 pr_info_ratelimited("Need \"+ip\", \"-ip\" or \"/\"\n");
591 return -EINVAL;
592 }
593
594 ++c;
595 --size;
596 if (strnchr(c, size, ':') != NULL) {
597 family = NFPROTO_IPV6;
598 succ = in6_pton(c, size, (void *)&addr, '\n', NULL);
599 } else {
600 family = NFPROTO_IPV4;
601 succ = in4_pton(c, size, (void *)&addr, '\n', NULL);
602 }
603
604 if (!succ)
605 return -EINVAL;
606
607 spin_lock_bh(&recent_lock);
608 e = recent_entry_lookup(t, &addr, family, 0);
609 if (e == NULL) {
610 if (add)
611 recent_entry_init(t, &addr, family, 0);
612 } else {
613 if (add)
614 recent_entry_update(t, e);
615 else
616 recent_entry_remove(t, e);
617 }
618 spin_unlock_bh(&recent_lock);
619 /* Note we removed one above */
620 *loff += size + 1;
621 return size + 1;
622}
623
624static const struct file_operations recent_mt_fops = {
625 .open = recent_seq_open,
626 .read = seq_read,
627 .write = recent_mt_proc_write,
628 .release = seq_release_private,
629 .owner = THIS_MODULE,
630 .llseek = seq_lseek,
631};
632
633static int __net_init recent_proc_net_init(struct net *net)
634{
635 struct recent_net *recent_net = recent_pernet(net);
636
637 recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
638 if (!recent_net->xt_recent)
639 return -ENOMEM;
640 return 0;
641}
642
643static void __net_exit recent_proc_net_exit(struct net *net)
644{
645 struct recent_net *recent_net = recent_pernet(net);
646 struct recent_table *t;
647
648 /* recent_net_exit() is called before recent_mt_destroy(). Make sure
649 * that the parent xt_recent proc entry is is empty before trying to
650 * remove it.
651 */
652 spin_lock_bh(&recent_lock);
653 list_for_each_entry(t, &recent_net->tables, list)
654 remove_proc_entry(t->name, recent_net->xt_recent);
655
656 recent_net->xt_recent = NULL;
657 spin_unlock_bh(&recent_lock);
658
659 remove_proc_entry("xt_recent", net->proc_net);
660}
661#else
662static inline int recent_proc_net_init(struct net *net)
663{
664 return 0;
665}
666
667static inline void recent_proc_net_exit(struct net *net)
668{
669}
670#endif /* CONFIG_PROC_FS */
671
672static int __net_init recent_net_init(struct net *net)
673{
674 struct recent_net *recent_net = recent_pernet(net);
675
676 INIT_LIST_HEAD(&recent_net->tables);
677 return recent_proc_net_init(net);
678}
679
680static void __net_exit recent_net_exit(struct net *net)
681{
682 recent_proc_net_exit(net);
683}
684
685static struct pernet_operations recent_net_ops = {
686 .init = recent_net_init,
687 .exit = recent_net_exit,
688 .id = &recent_net_id,
689 .size = sizeof(struct recent_net),
690};
691
692static struct xt_match recent_mt_reg[] __read_mostly = {
693 {
694 .name = "recent",
695 .revision = 0,
696 .family = NFPROTO_IPV4,
697 .match = recent_mt,
698 .matchsize = sizeof(struct xt_recent_mtinfo),
699 .checkentry = recent_mt_check_v0,
700 .destroy = recent_mt_destroy,
701 .me = THIS_MODULE,
702 },
703 {
704 .name = "recent",
705 .revision = 0,
706 .family = NFPROTO_IPV6,
707 .match = recent_mt,
708 .matchsize = sizeof(struct xt_recent_mtinfo),
709 .checkentry = recent_mt_check_v0,
710 .destroy = recent_mt_destroy,
711 .me = THIS_MODULE,
712 },
713 {
714 .name = "recent",
715 .revision = 1,
716 .family = NFPROTO_IPV4,
717 .match = recent_mt,
718 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
719 .checkentry = recent_mt_check_v1,
720 .destroy = recent_mt_destroy,
721 .me = THIS_MODULE,
722 },
723 {
724 .name = "recent",
725 .revision = 1,
726 .family = NFPROTO_IPV6,
727 .match = recent_mt,
728 .matchsize = sizeof(struct xt_recent_mtinfo_v1),
729 .checkentry = recent_mt_check_v1,
730 .destroy = recent_mt_destroy,
731 .me = THIS_MODULE,
732 }
733};
734
735static int __init recent_mt_init(void)
736{
737 int err;
738
739 BUILD_BUG_ON_NOT_POWER_OF_2(XT_RECENT_MAX_NSTAMPS);
740
741 if (!ip_list_tot || ip_pkt_list_tot >= XT_RECENT_MAX_NSTAMPS)
742 return -EINVAL;
743 ip_list_hash_size = 1 << fls(ip_list_tot);
744
745 err = register_pernet_subsys(&recent_net_ops);
746 if (err)
747 return err;
748 err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
749 if (err)
750 unregister_pernet_subsys(&recent_net_ops);
751 return err;
752}
753
754static void __exit recent_mt_exit(void)
755{
756 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
757 unregister_pernet_subsys(&recent_net_ops);
758}
759
760module_init(recent_mt_init);
761module_exit(recent_mt_exit);