net/netfilter/xt_recent.c

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