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 #include <linux/init.h>
  16 #include <linux/ip.h>
  17 #include <linux/ipv6.h>
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/list.h>
  25 #include <linux/random.h>
  26 #include <linux/jhash.h>
  27 #include <linux/bitops.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/inet.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@computergmbh.de>");
  38 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4");
  39 MODULE_LICENSE("GPL");
  40 MODULE_ALIAS("ipt_recent");
  41 MODULE_ALIAS("ip6t_recent");
  42
  43 static unsigned int ip_list_tot = 100;
  44 static unsigned int ip_pkt_list_tot = 20;
  45 static unsigned int ip_list_hash_size = 0;
  46 static unsigned int ip_list_perms = 0644;
  47 static unsigned int ip_list_uid = 0;
  48 static unsigned int ip_list_gid = 0;
  49 module_param(ip_list_tot, uint, 0400);
  50 module_param(ip_pkt_list_tot, uint, 0400);
  51 module_param(ip_list_hash_size, uint, 0400);
  52 module_param(ip_list_perms, uint, 0400);
  53 module_param(ip_list_uid, uint, 0400);
  54 module_param(ip_list_gid, uint, 0400);
  55 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  56 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP to remember (max. 255)");
  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,"owner of /proc/net/xt_recent/* files");
  60 MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files");
  61
  62 struct recent_entry {
  63         struct list_head        list;
  64         struct list_head        lru_list;
  65         union nf_inet_addr      addr;
  66         u_int16_t               family;
  67         u_int8_t                ttl;
  68         u_int8_t                index;
  69         u_int16_t               nstamps;
  70         unsigned long           stamps[0];
  71 };
  72
  73 struct recent_table {
  74         struct list_head        list;
  75         char                    name[XT_RECENT_NAME_LEN];
  76         unsigned int            refcnt;
  77         unsigned int            entries;
  78         struct list_head        lru_list;
  79         struct list_head        iphash[0];
  80 };
  81
  82 struct recent_net {
  83         struct list_head        tables;
  84 #ifdef CONFIG_PROC_FS
  85         struct proc_dir_entry   *xt_recent;
  86 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  87         struct proc_dir_entry   *ipt_recent;
  88 #endif
  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 static struct recent_entry *
 150 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 151                   u_int16_t family, u_int8_t ttl)
 152 {
 153         struct recent_entry *e;
 154
 155         if (t->entries >= ip_list_tot) {
 156                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 157                 recent_entry_remove(t, e);
 158         }
 159         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 160                     GFP_ATOMIC);
 161         if (e == NULL)
 162                 return NULL;
 163         memcpy(&e->addr, addr, sizeof(e->addr));
 164         e->ttl       = ttl;
 165         e->stamps[0] = jiffies;
 166         e->nstamps   = 1;
 167         e->index     = 1;
 168         e->family    = family;
 169         if (family == NFPROTO_IPV4)
 170                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 171         else
 172                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 173         list_add_tail(&e->lru_list, &t->lru_list);
 174         t->entries++;
 175         return e;
 176 }
 177
 178 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 179 {
 180         e->stamps[e->index++] = jiffies;
 181         if (e->index > e->nstamps)
 182                 e->nstamps = e->index;
 183         e->index %= ip_pkt_list_tot;
 184         list_move_tail(&e->lru_list, &t->lru_list);
 185 }
 186
 187 static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
 188                                                 const char *name)
 189 {
 190         struct recent_table *t;
 191
 192         list_for_each_entry(t, &recent_net->tables, list)
 193                 if (!strcmp(t->name, name))
 194                         return t;
 195         return NULL;
 196 }
 197
 198 static void recent_table_flush(struct recent_table *t)
 199 {
 200         struct recent_entry *e, *next;
 201         unsigned int i;
 202
 203         for (i = 0; i < ip_list_hash_size; i++)
 204                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 205                         recent_entry_remove(t, e);
 206 }
 207
 208 static bool
 209 recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 210 {
 211         struct net *net = dev_net(par->in ? par->in : par->out);
 212         struct recent_net *recent_net = recent_pernet(net);
 213         const struct xt_recent_mtinfo *info = par->matchinfo;
 214         struct recent_table *t;
 215         struct recent_entry *e;
 216         union nf_inet_addr addr = {};
 217         u_int8_t ttl;
 218         bool ret = info->invert;
 219
 220         if (par->match->family == NFPROTO_IPV4) {
 221                 const struct iphdr *iph = ip_hdr(skb);
 222
 223                 if (info->side == XT_RECENT_DEST)
 224                         addr.ip = iph->daddr;
 225                 else
 226                         addr.ip = iph->saddr;
 227
 228                 ttl = iph->ttl;
 229         } else {
 230                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 231
 232                 if (info->side == XT_RECENT_DEST)
 233                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 234                 else
 235                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 236
 237                 ttl = iph->hop_limit;
 238         }
 239
 240         /* use TTL as seen before forwarding */
 241         if (par->out != NULL && skb->sk == NULL)
 242                 ttl++;
 243
 244         spin_lock_bh(&recent_lock);
 245         t = recent_table_lookup(recent_net, info->name);
 246         e = recent_entry_lookup(t, &addr, par->match->family,
 247                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 248         if (e == NULL) {
 249                 if (!(info->check_set & XT_RECENT_SET))
 250                         goto out;
 251                 e = recent_entry_init(t, &addr, par->match->family, ttl);
 252                 if (e == NULL)
 253                         *par->hotdrop = true;
 254                 ret = !ret;
 255                 goto out;
 256         }
 257
 258         if (info->check_set & XT_RECENT_SET)
 259                 ret = !ret;
 260         else if (info->check_set & XT_RECENT_REMOVE) {
 261                 recent_entry_remove(t, e);
 262                 ret = !ret;
 263         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 264                 unsigned long time = jiffies - info->seconds * HZ;
 265                 unsigned int i, hits = 0;
 266
 267                 for (i = 0; i < e->nstamps; i++) {
 268                         if (info->seconds && time_after(time, e->stamps[i]))
 269                                 continue;
 270                         if (++hits >= info->hit_count) {
 271                                 ret = !ret;
 272                                 break;
 273                         }
 274                 }
 275         }
 276
 277         if (info->check_set & XT_RECENT_SET ||
 278             (info->check_set & XT_RECENT_UPDATE && ret)) {
 279                 recent_entry_update(t, e);
 280                 e->ttl = ttl;
 281         }
 282 out:
 283         spin_unlock_bh(&recent_lock);
 284         return ret;
 285 }
 286
 287 static bool recent_mt_check(const struct xt_mtchk_param *par)
 288 {
 289         struct recent_net *recent_net = recent_pernet(par->net);
 290         const struct xt_recent_mtinfo *info = par->matchinfo;
 291         struct recent_table *t;
 292 #ifdef CONFIG_PROC_FS
 293         struct proc_dir_entry *pde;
 294 #endif
 295         unsigned i;
 296         bool ret = false;
 297
 298         if (unlikely(!hash_rnd_inited)) {
 299                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 300                 hash_rnd_inited = true;
 301         }
 302         if (hweight8(info->check_set &
 303                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 304                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 305                 return false;
 306         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 307             (info->seconds || info->hit_count))
 308                 return false;
 309         if (info->hit_count > ip_pkt_list_tot)
 310                 return false;
 311         if (info->name[0] == '\0' ||
 312             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 313                 return false;
 314
 315         mutex_lock(&recent_mutex);
 316         t = recent_table_lookup(recent_net, info->name);
 317         if (t != NULL) {
 318                 t->refcnt++;
 319                 ret = true;
 320                 goto out;
 321         }
 322
 323         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
 324                     GFP_KERNEL);
 325         if (t == NULL)
 326                 goto out;
 327         t->refcnt = 1;
 328         strcpy(t->name, info->name);
 329         INIT_LIST_HEAD(&t->lru_list);
 330         for (i = 0; i < ip_list_hash_size; i++)
 331                 INIT_LIST_HEAD(&t->iphash[i]);
 332 #ifdef CONFIG_PROC_FS
 333         pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
 334                   &recent_mt_fops, t);
 335         if (pde == NULL) {
 336                 kfree(t);
 337                 goto out;
 338         }
 339         pde->uid = ip_list_uid;
 340         pde->gid = ip_list_gid;
 341 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 342         pde = proc_create_data(t->name, ip_list_perms, recent_net->ipt_recent,
 343                       &recent_old_fops, t);
 344         if (pde == NULL) {
 345                 remove_proc_entry(t->name, recent_net->xt_recent);
 346                 kfree(t);
 347                 goto out;
 348         }
 349         pde->uid = ip_list_uid;
 350         pde->gid = ip_list_gid;
 351 #endif
 352 #endif
 353         spin_lock_bh(&recent_lock);
 354         list_add_tail(&t->list, &recent_net->tables);
 355         spin_unlock_bh(&recent_lock);
 356         ret = true;
 357 out:
 358         mutex_unlock(&recent_mutex);
 359         return ret;
 360 }
 361
 362 static void recent_mt_destroy(const struct xt_mtdtor_param *par)
 363 {
 364         struct recent_net *recent_net = recent_pernet(par->net);
 365         const struct xt_recent_mtinfo *info = par->matchinfo;
 366         struct recent_table *t;
 367
 368         mutex_lock(&recent_mutex);
 369         t = recent_table_lookup(recent_net, info->name);
 370         if (--t->refcnt == 0) {
 371                 spin_lock_bh(&recent_lock);
 372                 list_del(&t->list);
 373                 spin_unlock_bh(&recent_lock);
 374 #ifdef CONFIG_PROC_FS
 375 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 376                 remove_proc_entry(t->name, recent_net->ipt_recent);
 377 #endif
 378                 remove_proc_entry(t->name, recent_net->xt_recent);
 379 #endif
 380                 recent_table_flush(t);
 381                 kfree(t);
 382         }
 383         mutex_unlock(&recent_mutex);
 384 }
 385
 386 #ifdef CONFIG_PROC_FS
 387 struct recent_iter_state {
 388         const struct recent_table *table;
 389         unsigned int            bucket;
 390 };
 391
 392 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 393         __acquires(recent_lock)
 394 {
 395         struct recent_iter_state *st = seq->private;
 396         const struct recent_table *t = st->table;
 397         struct recent_entry *e;
 398         loff_t p = *pos;
 399
 400         spin_lock_bh(&recent_lock);
 401
 402         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
 403                 list_for_each_entry(e, &t->iphash[st->bucket], list)
 404                         if (p-- == 0)
 405                                 return e;
 406         return NULL;
 407 }
 408
 409 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 410 {
 411         struct recent_iter_state *st = seq->private;
 412         const struct recent_table *t = st->table;
 413         const struct recent_entry *e = v;
 414         const struct list_head *head = e->list.next;
 415
 416         while (head == &t->iphash[st->bucket]) {
 417                 if (++st->bucket >= ip_list_hash_size)
 418                         return NULL;
 419                 head = t->iphash[st->bucket].next;
 420         }
 421         (*pos)++;
 422         return list_entry(head, struct recent_entry, list);
 423 }
 424
 425 static void recent_seq_stop(struct seq_file *s, void *v)
 426         __releases(recent_lock)
 427 {
 428         spin_unlock_bh(&recent_lock);
 429 }
 430
 431 static int recent_seq_show(struct seq_file *seq, void *v)
 432 {
 433         const struct recent_entry *e = v;
 434         unsigned int i;
 435
 436         i = (e->index - 1) % ip_pkt_list_tot;
 437         if (e->family == NFPROTO_IPV4)
 438                 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
 439                            &e->addr.ip, e->ttl, e->stamps[i], e->index);
 440         else
 441                 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
 442                            &e->addr.in6, e->ttl, e->stamps[i], e->index);
 443         for (i = 0; i < e->nstamps; i++)
 444                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 445         seq_printf(seq, "\n");
 446         return 0;
 447 }
 448
 449 static const struct seq_operations recent_seq_ops = {
 450         .start          = recent_seq_start,
 451         .next           = recent_seq_next,
 452         .stop           = recent_seq_stop,
 453         .show           = recent_seq_show,
 454 };
 455
 456 static int recent_seq_open(struct inode *inode, struct file *file)
 457 {
 458         struct proc_dir_entry *pde = PDE(inode);
 459         struct recent_iter_state *st;
 460
 461         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 462         if (st == NULL)
 463                 return -ENOMEM;
 464
 465         st->table    = pde->data;
 466         return 0;
 467 }
 468
 469 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 470 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 471 {
 472         static bool warned_of_old;
 473
 474         if (unlikely(!warned_of_old)) {
 475                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 476                        " is deprecated; use /proc/net/xt_recent.\n");
 477                 warned_of_old = true;
 478         }
 479         return recent_seq_open(inode, filp);
 480 }
 481
 482 static ssize_t recent_old_proc_write(struct file *file,
 483                                      const char __user *input,
 484                                      size_t size, loff_t *loff)
 485 {
 486         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 487         struct recent_table *t = pde->data;
 488         struct recent_entry *e;
 489         char buf[sizeof("+255.255.255.255")], *c = buf;
 490         union nf_inet_addr addr = {};
 491         int add;
 492
 493         if (size > sizeof(buf))
 494                 size = sizeof(buf);
 495         if (copy_from_user(buf, input, size))
 496                 return -EFAULT;
 497
 498         c = skip_spaces(c);
 499
 500         if (size - (c - buf) < 5)
 501                 return c - buf;
 502         if (!strncmp(c, "clear", 5)) {
 503                 c += 5;
 504                 spin_lock_bh(&recent_lock);
 505                 recent_table_flush(t);
 506                 spin_unlock_bh(&recent_lock);
 507                 return c - buf;
 508         }
 509
 510         switch (*c) {
 511         case '-':
 512                 add = 0;
 513                 c++;
 514                 break;
 515         case '+':
 516                 c++;
 517         default:
 518                 add = 1;
 519                 break;
 520         }
 521         addr.ip = in_aton(c);
 522
 523         spin_lock_bh(&recent_lock);
 524         e = recent_entry_lookup(t, &addr, NFPROTO_IPV4, 0);
 525         if (e == NULL) {
 526                 if (add)
 527                         recent_entry_init(t, &addr, NFPROTO_IPV4, 0);
 528         } else {
 529                 if (add)
 530                         recent_entry_update(t, e);
 531                 else
 532                         recent_entry_remove(t, e);
 533         }
 534         spin_unlock_bh(&recent_lock);
 535         return size;
 536 }
 537
 538 static const struct file_operations recent_old_fops = {
 539         .open           = recent_old_seq_open,
 540         .read           = seq_read,
 541         .write          = recent_old_proc_write,
 542         .release        = seq_release_private,
 543         .owner          = THIS_MODULE,
 544 };
 545 #endif
 546
 547 static ssize_t
 548 recent_mt_proc_write(struct file *file, const char __user *input,
 549                      size_t size, loff_t *loff)
 550 {
 551         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 552         struct recent_table *t = pde->data;
 553         struct recent_entry *e;
 554         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 555         const char *c = buf;
 556         union nf_inet_addr addr = {};
 557         u_int16_t family;
 558         bool add, succ;
 559
 560         if (size == 0)
 561                 return 0;
 562         if (size > sizeof(buf))
 563                 size = sizeof(buf);
 564         if (copy_from_user(buf, input, size) != 0)
 565                 return -EFAULT;
 566
 567         /* Strict protocol! */
 568         if (*loff != 0)
 569                 return -ESPIPE;
 570         switch (*c) {
 571         case '/': /* flush table */
 572                 spin_lock_bh(&recent_lock);
 573                 recent_table_flush(t);
 574                 spin_unlock_bh(&recent_lock);
 575                 return size;
 576         case '-': /* remove address */
 577                 add = false;
 578                 break;
 579         case '+': /* add address */
 580                 add = true;
 581                 break;
 582         default:
 583                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 584                 return -EINVAL;
 585         }
 586
 587         ++c;
 588         --size;
 589         if (strnchr(c, size, ':') != NULL) {
 590                 family = NFPROTO_IPV6;
 591                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 592         } else {
 593                 family = NFPROTO_IPV4;
 594                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 595         }
 596
 597         if (!succ) {
 598                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 599                        "to procfs\n");
 600                 return -EINVAL;
 601         }
 602
 603         spin_lock_bh(&recent_lock);
 604         e = recent_entry_lookup(t, &addr, family, 0);
 605         if (e == NULL) {
 606                 if (add)
 607                         recent_entry_init(t, &addr, family, 0);
 608         } else {
 609                 if (add)
 610                         recent_entry_update(t, e);
 611                 else
 612                         recent_entry_remove(t, e);
 613         }
 614         spin_unlock_bh(&recent_lock);
 615         /* Note we removed one above */
 616         *loff += size + 1;
 617         return size + 1;
 618 }
 619
 620 static const struct file_operations recent_mt_fops = {
 621         .open    = recent_seq_open,
 622         .read    = seq_read,
 623         .write   = recent_mt_proc_write,
 624         .release = seq_release_private,
 625         .owner   = THIS_MODULE,
 626 };
 627
 628 static int __net_init recent_proc_net_init(struct net *net)
 629 {
 630         struct recent_net *recent_net = recent_pernet(net);
 631
 632         recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
 633         if (!recent_net->xt_recent)
 634                 return -ENOMEM;
 635 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 636         recent_net->ipt_recent = proc_mkdir("ipt_recent", net->proc_net);
 637         if (!recent_net->ipt_recent) {
 638                 proc_net_remove(net, "xt_recent");
 639                 return -ENOMEM;
 640         }
 641 #endif
 642         return 0;
 643 }
 644
 645 static void __net_exit recent_proc_net_exit(struct net *net)
 646 {
 647 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 648         proc_net_remove(net, "ipt_recent");
 649 #endif
 650         proc_net_remove(net, "xt_recent");
 651 }
 652 #else
 653 static inline int recent_proc_net_init(struct net *net)
 654 {
 655         return 0;
 656 }
 657
 658 static inline void recent_proc_net_exit(struct net *net)
 659 {
 660 }
 661 #endif /* CONFIG_PROC_FS */
 662
 663 static int __net_init recent_net_init(struct net *net)
 664 {
 665         struct recent_net *recent_net = recent_pernet(net);
 666
 667         INIT_LIST_HEAD(&recent_net->tables);
 668         return recent_proc_net_init(net);
 669 }
 670
 671 static void __net_exit recent_net_exit(struct net *net)
 672 {
 673         struct recent_net *recent_net = recent_pernet(net);
 674
 675         BUG_ON(!list_empty(&recent_net->tables));
 676         recent_proc_net_exit(net);
 677 }
 678
 679 static struct pernet_operations recent_net_ops = {
 680         .init   = recent_net_init,
 681         .exit   = recent_net_exit,
 682         .id     = &recent_net_id,
 683         .size   = sizeof(struct recent_net),
 684 };
 685
 686 static struct xt_match recent_mt_reg[] __read_mostly = {
 687         {
 688                 .name       = "recent",
 689                 .revision   = 0,
 690                 .family     = NFPROTO_IPV4,
 691                 .match      = recent_mt,
 692                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 693                 .checkentry = recent_mt_check,
 694                 .destroy    = recent_mt_destroy,
 695                 .me         = THIS_MODULE,
 696         },
 697         {
 698                 .name       = "recent",
 699                 .revision   = 0,
 700                 .family     = NFPROTO_IPV6,
 701                 .match      = recent_mt,
 702                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 703                 .checkentry = recent_mt_check,
 704                 .destroy    = recent_mt_destroy,
 705                 .me         = THIS_MODULE,
 706         },
 707 };
 708
 709 static int __init recent_mt_init(void)
 710 {
 711         int err;
 712
 713         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 714                 return -EINVAL;
 715         ip_list_hash_size = 1 << fls(ip_list_tot);
 716
 717         err = register_pernet_subsys(&recent_net_ops);
 718         if (err)
 719                 return err;
 720         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 721         if (err)
 722                 unregister_pernet_subsys(&recent_net_ops);
 723         return err;
 724 }
 725
 726 static void __exit recent_mt_exit(void)
 727 {
 728         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 729         unregister_pernet_subsys(&recent_net_ops);
 730 }
 731
 732 module_init(recent_mt_init);
 733 module_exit(recent_mt_exit);