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
36 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
37 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
38 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
39 MODULE_LICENSE("GPL");
40 MODULE_ALIAS("ipt_recent");
41 MODULE_ALIAS("ip6t_recent");
42
43 static unsigned int ip_list_tot __read_mostly = 100;
44 static unsigned int ip_list_hash_size __read_mostly;
45 static unsigned int ip_list_perms __read_mostly = 0644;
46 static unsigned int ip_list_uid __read_mostly;
47 static unsigned int ip_list_gid __read_mostly;
48 module_param(ip_list_tot, uint, 0400);
49 module_param(ip_list_hash_size, uint, 0400);
50 module_param(ip_list_perms, uint, 0400);
51 module_param(ip_list_uid, uint, 0644);
52 module_param(ip_list_gid, uint, 0644);
53 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
54 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
55 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
56 MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
57 MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
58
59 /* retained for backwards compatibility */
60 static unsigned int ip_pkt_list_tot __read_mostly;
61 module_param(ip_pkt_list_tot, uint, 0400);
62 MODULE_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
66 struct 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
77 struct 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
88 struct recent_net {
89 struct list_head tables;
90 #ifdef CONFIG_PROC_FS
91 struct proc_dir_entry *xt_recent;
92 #endif
93 };
94
95 static unsigned int recent_net_id __read_mostly;
96
recent_pernet(struct net * net)97 static inline struct recent_net *recent_pernet(struct net *net)
98 {
99 return net_generic(net, recent_net_id);
100 }
101
102 static DEFINE_SPINLOCK(recent_lock);
103 static DEFINE_MUTEX(recent_mutex);
104
105 #ifdef CONFIG_PROC_FS
106 static const struct proc_ops recent_mt_proc_ops;
107 #endif
108
109 static u_int32_t hash_rnd __read_mostly;
110
recent_entry_hash4(const union nf_inet_addr * addr)111 static 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
recent_entry_hash6(const union nf_inet_addr * addr)117 static 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
123 static struct recent_entry *
recent_entry_lookup(const struct recent_table * table,const union nf_inet_addr * addrp,u_int16_t family,u_int8_t ttl)124 recent_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
recent_entry_remove(struct recent_table * t,struct recent_entry * e)144 static 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 */
recent_entry_reap(struct recent_table * t,unsigned long time,struct recent_entry * working,bool update)155 static 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
178 static struct recent_entry *
recent_entry_init(struct recent_table * t,const union nf_inet_addr * addr,u_int16_t family,u_int8_t ttl)179 recent_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
recent_entry_update(struct recent_table * t,struct recent_entry * e)209 static 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
recent_table_lookup(struct recent_net * recent_net,const char * name)218 static 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
recent_table_flush(struct recent_table * t)229 static 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
239 static bool
recent_mt(const struct sk_buff * skb,struct xt_action_param * par)240 recent_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 }
322 out:
323 spin_unlock_bh(&recent_lock);
324 return ret;
325 }
326
recent_table_free(void * addr)327 static void recent_table_free(void *addr)
328 {
329 kvfree(addr);
330 }
331
recent_mt_check(const struct xt_mtchk_param * par,const struct xt_recent_mtinfo_v1 * info)332 static 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;
428 out:
429 mutex_unlock(&recent_mutex);
430 return ret;
431 }
432
recent_mt_check_v0(const struct xt_mtchk_param * par)433 static 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
recent_mt_check_v1(const struct xt_mtchk_param * par)446 static int recent_mt_check_v1(const struct xt_mtchk_param *par)
447 {
448 return recent_mt_check(par, par->matchinfo);
449 }
450
recent_mt_destroy(const struct xt_mtdtor_param * par)451 static 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
474 struct recent_iter_state {
475 const struct recent_table *table;
476 unsigned int bucket;
477 };
478
recent_seq_start(struct seq_file * seq,loff_t * pos)479 static 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
recent_seq_next(struct seq_file * seq,void * v,loff_t * pos)496 static 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
recent_seq_stop(struct seq_file * s,void * v)512 static void recent_seq_stop(struct seq_file *s, void *v)
513 __releases(recent_lock)
514 {
515 spin_unlock_bh(&recent_lock);
516 }
517
recent_seq_show(struct seq_file * seq,void * v)518 static 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
539 static 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
recent_seq_open(struct inode * inode,struct file * file)546 static 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
558 static ssize_t
recent_mt_proc_write(struct file * file,const char __user * input,size_t size,loff_t * loff)559 recent_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:1715:255.255.255.255")];
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
627 static 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
recent_proc_net_init(struct net * net)635 static 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
recent_proc_net_exit(struct net * net)645 static 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
recent_proc_net_init(struct net * net)664 static inline int recent_proc_net_init(struct net *net)
665 {
666 return 0;
667 }
668
recent_proc_net_exit(struct net * net)669 static inline void recent_proc_net_exit(struct net *net)
670 {
671 }
672 #endif /* CONFIG_PROC_FS */
673
recent_net_init(struct net * net)674 static 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
recent_net_exit(struct net * net)682 static void __net_exit recent_net_exit(struct net *net)
683 {
684 recent_proc_net_exit(net);
685 }
686
687 static 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
694 static 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
recent_mt_init(void)737 static 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
recent_mt_exit(void)756 static 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
762 module_init(recent_mt_init);
763 module_exit(recent_mt_exit);
764