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
39 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
40 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
41 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
42 MODULE_LICENSE("GPL");
43 MODULE_ALIAS("ipt_recent");
44 MODULE_ALIAS("ip6t_recent");
45
46 static unsigned int ip_list_tot __read_mostly = 100;
47 static unsigned int ip_list_hash_size __read_mostly;
48 static unsigned int ip_list_perms __read_mostly = 0644;
49 static unsigned int ip_list_uid __read_mostly;
50 static unsigned int ip_list_gid __read_mostly;
51 module_param(ip_list_tot, uint, 0400);
52 module_param(ip_list_hash_size, uint, 0400);
53 module_param(ip_list_perms, uint, 0400);
54 module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
55 module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
56 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
57 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
58 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
59 MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
60 MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
61
62 /* retained for backwards compatibility */
63 static unsigned int ip_pkt_list_tot __read_mostly;
64 module_param(ip_pkt_list_tot, uint, 0400);
65 MODULE_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
69 struct 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
80 struct 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
91 struct recent_net {
92 struct list_head tables;
93 #ifdef CONFIG_PROC_FS
94 struct proc_dir_entry *xt_recent;
95 #endif
96 };
97
98 static int recent_net_id __read_mostly;
99
recent_pernet(struct net * net)100 static inline struct recent_net *recent_pernet(struct net *net)
101 {
102 return net_generic(net, recent_net_id);
103 }
104
105 static DEFINE_SPINLOCK(recent_lock);
106 static DEFINE_MUTEX(recent_mutex);
107
108 #ifdef CONFIG_PROC_FS
109 static const struct file_operations recent_old_fops, recent_mt_fops;
110 #endif
111
112 static u_int32_t hash_rnd __read_mostly;
113
recent_entry_hash4(const union nf_inet_addr * addr)114 static 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
recent_entry_hash6(const union nf_inet_addr * addr)120 static 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
126 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)127 recent_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
recent_entry_remove(struct recent_table * t,struct recent_entry * e)147 static 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 */
recent_entry_reap(struct recent_table * t,unsigned long time)158 static 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
174 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)175 recent_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
recent_entry_update(struct recent_table * t,struct recent_entry * e)206 static 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
recent_table_lookup(struct recent_net * recent_net,const char * name)215 static 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
recent_table_flush(struct recent_table * t)226 static 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
236 static bool
recent_mt(const struct sk_buff * skb,struct xt_action_param * par)237 recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
238 {
239 struct net *net = par->net;
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 (par->family == 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 (par->out != 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, par->family,
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, par->family, 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 }
317 out:
318 spin_unlock_bh(&recent_lock);
319 return ret;
320 }
321
recent_table_free(void * addr)322 static void recent_table_free(void *addr)
323 {
324 kvfree(addr);
325 }
326
recent_mt_check(const struct xt_mtchk_param * par,const struct xt_recent_mtinfo_v1 * info)327 static 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 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 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;
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 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
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_printf(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:1715:5afe: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("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 /* Note we removed one above */
625 *loff += size + 1;
626 return size + 1;
627 }
628
629 static 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
recent_proc_net_init(struct net * net)638 static 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
recent_proc_net_exit(struct net * net)648 static 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 /* recent_net_exit() is called before recent_mt_destroy(). Make sure
654 * that the parent xt_recent proc entry is is empty before trying to
655 * remove it.
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
recent_proc_net_init(struct net * net)667 static inline int recent_proc_net_init(struct net *net)
668 {
669 return 0;
670 }
671
recent_proc_net_exit(struct net * net)672 static inline void recent_proc_net_exit(struct net *net)
673 {
674 }
675 #endif /* CONFIG_PROC_FS */
676
recent_net_init(struct net * net)677 static 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
recent_net_exit(struct net * net)685 static void __net_exit recent_net_exit(struct net *net)
686 {
687 recent_proc_net_exit(net);
688 }
689
690 static 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
697 static 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
recent_mt_init(void)740 static 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
recent_mt_exit(void)759 static 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
765 module_init(recent_mt_init);
766 module_exit(recent_mt_exit);
767