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
  32 #include <linux/netfilter/x_tables.h>
  33 #include <linux/netfilter/xt_recent.h>
  34
  35 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  36 MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
  37 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4");
  38 MODULE_LICENSE("GPL");
  39 MODULE_ALIAS("ipt_recent");
  40 MODULE_ALIAS("ip6t_recent");
  41
  42 static unsigned int ip_list_tot = 100;
  43 static unsigned int ip_pkt_list_tot = 20;
  44 static unsigned int ip_list_hash_size = 0;
  45 static unsigned int ip_list_perms = 0644;
  46 static unsigned int ip_list_uid = 0;
  47 static unsigned int ip_list_gid = 0;
  48 module_param(ip_list_tot, uint, 0400);
  49 module_param(ip_pkt_list_tot, uint, 0400);
  50 module_param(ip_list_hash_size, uint, 0400);
  51 module_param(ip_list_perms, uint, 0400);
  52 module_param(ip_list_uid, uint, 0400);
  53 module_param(ip_list_gid, uint, 0400);
  54 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  55 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP to remember (max. 255)");
  56 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
  57 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
  58 MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/xt_recent/* files");
  59 MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files");
  60
  61 struct recent_entry {
  62         struct list_head        list;
  63         struct list_head        lru_list;
  64         union nf_inet_addr      addr;
  65         u_int16_t               family;
  66         u_int8_t                ttl;
  67         u_int8_t                index;
  68         u_int16_t               nstamps;
  69         unsigned long           stamps[0];
  70 };
  71
  72 struct recent_table {
  73         struct list_head        list;
  74         char                    name[XT_RECENT_NAME_LEN];
  75         unsigned int            refcnt;
  76         unsigned int            entries;
  77         struct list_head        lru_list;
  78         struct list_head        iphash[0];
  79 };
  80
  81 static LIST_HEAD(tables);
  82 static DEFINE_SPINLOCK(recent_lock);
  83 static DEFINE_MUTEX(recent_mutex);
  84
  85 #ifdef CONFIG_PROC_FS
  86 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  87 static struct proc_dir_entry *proc_old_dir;
  88 #endif
  89 static struct proc_dir_entry *recent_proc_dir;
  90 static const struct file_operations recent_old_fops, recent_mt_fops;
  91 #endif
  92
  93 static u_int32_t hash_rnd;
  94 static bool hash_rnd_initted;
  95
  96 static unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
  97 {
  98         if (!hash_rnd_initted) {
  99                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 100                 hash_rnd_initted = true;
 101         }
 102         return jhash_1word((__force u32)addr->ip, hash_rnd) &
 103                (ip_list_hash_size - 1);
 104 }
 105
 106 static unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
 107 {
 108         if (!hash_rnd_initted) {
 109                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 110                 hash_rnd_initted = true;
 111         }
 112         return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
 113                (ip_list_hash_size - 1);
 114 }
 115
 116 static struct recent_entry *
 117 recent_entry_lookup(const struct recent_table *table,
 118                     const union nf_inet_addr *addrp, u_int16_t family,
 119                     u_int8_t ttl)
 120 {
 121         struct recent_entry *e;
 122         unsigned int h;
 123
 124         if (family == NFPROTO_IPV4)
 125                 h = recent_entry_hash4(addrp);
 126         else
 127                 h = recent_entry_hash6(addrp);
 128
 129         list_for_each_entry(e, &table->iphash[h], list)
 130                 if (e->family == family &&
 131                     memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
 132                     (ttl == e->ttl || ttl == 0 || e->ttl == 0))
 133                         return e;
 134         return NULL;
 135 }
 136
 137 static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
 138 {
 139         list_del(&e->list);
 140         list_del(&e->lru_list);
 141         kfree(e);
 142         t->entries--;
 143 }
 144
 145 static struct recent_entry *
 146 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 147                   u_int16_t family, u_int8_t ttl)
 148 {
 149         struct recent_entry *e;
 150
 151         if (t->entries >= ip_list_tot) {
 152                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 153                 recent_entry_remove(t, e);
 154         }
 155         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 156                     GFP_ATOMIC);
 157         if (e == NULL)
 158                 return NULL;
 159         memcpy(&e->addr, addr, sizeof(e->addr));
 160         e->ttl       = ttl;
 161         e->stamps[0] = jiffies;
 162         e->nstamps   = 1;
 163         e->index     = 1;
 164         e->family    = family;
 165         if (family == NFPROTO_IPV4)
 166                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 167         else
 168                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 169         list_add_tail(&e->lru_list, &t->lru_list);
 170         t->entries++;
 171         return e;
 172 }
 173
 174 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 175 {
 176         e->index %= ip_pkt_list_tot;
 177         e->stamps[e->index++] = jiffies;
 178         if (e->index > e->nstamps)
 179                 e->nstamps = e->index;
 180         list_move_tail(&e->lru_list, &t->lru_list);
 181 }
 182
 183 static struct recent_table *recent_table_lookup(const char *name)
 184 {
 185         struct recent_table *t;
 186
 187         list_for_each_entry(t, &tables, list)
 188                 if (!strcmp(t->name, name))
 189                         return t;
 190         return NULL;
 191 }
 192
 193 static void recent_table_flush(struct recent_table *t)
 194 {
 195         struct recent_entry *e, *next;
 196         unsigned int i;
 197
 198         for (i = 0; i < ip_list_hash_size; i++)
 199                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 200                         recent_entry_remove(t, e);
 201 }
 202
 203 static bool
 204 recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 205 {
 206         const struct xt_recent_mtinfo *info = par->matchinfo;
 207         struct recent_table *t;
 208         struct recent_entry *e;
 209         union nf_inet_addr addr = {};
 210         u_int8_t ttl;
 211         bool ret = info->invert;
 212
 213         if (par->match->family == NFPROTO_IPV4) {
 214                 const struct iphdr *iph = ip_hdr(skb);
 215
 216                 if (info->side == XT_RECENT_DEST)
 217                         addr.ip = iph->daddr;
 218                 else
 219                         addr.ip = iph->saddr;
 220
 221                 ttl = iph->ttl;
 222         } else {
 223                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 224
 225                 if (info->side == XT_RECENT_DEST)
 226                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 227                 else
 228                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 229
 230                 ttl = iph->hop_limit;
 231         }
 232
 233         /* use TTL as seen before forwarding */
 234         if (par->out != NULL && skb->sk == NULL)
 235                 ttl++;
 236
 237         spin_lock_bh(&recent_lock);
 238         t = recent_table_lookup(info->name);
 239         e = recent_entry_lookup(t, &addr, par->match->family,
 240                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 241         if (e == NULL) {
 242                 if (!(info->check_set & XT_RECENT_SET))
 243                         goto out;
 244                 e = recent_entry_init(t, &addr, par->match->family, ttl);
 245                 if (e == NULL)
 246                         *par->hotdrop = true;
 247                 ret = !ret;
 248                 goto out;
 249         }
 250
 251         if (info->check_set & XT_RECENT_SET)
 252                 ret = !ret;
 253         else if (info->check_set & XT_RECENT_REMOVE) {
 254                 recent_entry_remove(t, e);
 255                 ret = !ret;
 256         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 257                 unsigned long time = jiffies - info->seconds * HZ;
 258                 unsigned int i, hits = 0;
 259
 260                 for (i = 0; i < e->nstamps; i++) {
 261                         if (info->seconds && time_after(time, e->stamps[i]))
 262                                 continue;
 263                         if (!info->hit_count || ++hits >= info->hit_count) {
 264                                 ret = !ret;
 265                                 break;
 266                         }
 267                 }
 268         }
 269
 270         if (info->check_set & XT_RECENT_SET ||
 271             (info->check_set & XT_RECENT_UPDATE && ret)) {
 272                 recent_entry_update(t, e);
 273                 e->ttl = ttl;
 274         }
 275 out:
 276         spin_unlock_bh(&recent_lock);
 277         return ret;
 278 }
 279
 280 static bool recent_mt_check(const struct xt_mtchk_param *par)
 281 {
 282         const struct xt_recent_mtinfo *info = par->matchinfo;
 283         struct recent_table *t;
 284 #ifdef CONFIG_PROC_FS
 285         struct proc_dir_entry *pde;
 286 #endif
 287         unsigned i;
 288         bool ret = false;
 289
 290         if (hweight8(info->check_set &
 291                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 292                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 293                 return false;
 294         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 295             (info->seconds || info->hit_count))
 296                 return false;
 297         if (info->hit_count > ip_pkt_list_tot)
 298                 return false;
 299         if (info->name[0] == '\0' ||
 300             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 301                 return false;
 302
 303         mutex_lock(&recent_mutex);
 304         t = recent_table_lookup(info->name);
 305         if (t != NULL) {
 306                 t->refcnt++;
 307                 ret = true;
 308                 goto out;
 309         }
 310
 311         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
 312                     GFP_KERNEL);
 313         if (t == NULL)
 314                 goto out;
 315         t->refcnt = 1;
 316         strcpy(t->name, info->name);
 317         INIT_LIST_HEAD(&t->lru_list);
 318         for (i = 0; i < ip_list_hash_size; i++)
 319                 INIT_LIST_HEAD(&t->iphash[i]);
 320 #ifdef CONFIG_PROC_FS
 321         pde = proc_create_data(t->name, ip_list_perms, recent_proc_dir,
 322                   &recent_mt_fops, t);
 323         if (pde == NULL) {
 324                 kfree(t);
 325                 goto out;
 326         }
 327         pde->uid = ip_list_uid;
 328         pde->gid = ip_list_gid;
 329 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 330         pde = proc_create_data(t->name, ip_list_perms, proc_old_dir,
 331                       &recent_old_fops, t);
 332         if (pde == NULL) {
 333                 remove_proc_entry(t->name, proc_old_dir);
 334                 kfree(t);
 335                 goto out;
 336         }
 337         pde->uid = ip_list_uid;
 338         pde->gid = ip_list_gid;
 339 #endif
 340 #endif
 341         spin_lock_bh(&recent_lock);
 342         list_add_tail(&t->list, &tables);
 343         spin_unlock_bh(&recent_lock);
 344         ret = true;
 345 out:
 346         mutex_unlock(&recent_mutex);
 347         return ret;
 348 }
 349
 350 static void recent_mt_destroy(const struct xt_mtdtor_param *par)
 351 {
 352         const struct xt_recent_mtinfo *info = par->matchinfo;
 353         struct recent_table *t;
 354
 355         mutex_lock(&recent_mutex);
 356         t = recent_table_lookup(info->name);
 357         if (--t->refcnt == 0) {
 358                 spin_lock_bh(&recent_lock);
 359                 list_del(&t->list);
 360                 spin_unlock_bh(&recent_lock);
 361 #ifdef CONFIG_PROC_FS
 362 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 363                 remove_proc_entry(t->name, proc_old_dir);
 364 #endif
 365                 remove_proc_entry(t->name, recent_proc_dir);
 366 #endif
 367                 recent_table_flush(t);
 368                 kfree(t);
 369         }
 370         mutex_unlock(&recent_mutex);
 371 }
 372
 373 #ifdef CONFIG_PROC_FS
 374 struct recent_iter_state {
 375         const struct recent_table *table;
 376         unsigned int            bucket;
 377 };
 378
 379 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 380         __acquires(recent_lock)
 381 {
 382         struct recent_iter_state *st = seq->private;
 383         const struct recent_table *t = st->table;
 384         struct recent_entry *e;
 385         loff_t p = *pos;
 386
 387         spin_lock_bh(&recent_lock);
 388
 389         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
 390                 list_for_each_entry(e, &t->iphash[st->bucket], list)
 391                         if (p-- == 0)
 392                                 return e;
 393         return NULL;
 394 }
 395
 396 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 397 {
 398         struct recent_iter_state *st = seq->private;
 399         const struct recent_table *t = st->table;
 400         const struct recent_entry *e = v;
 401         const struct list_head *head = e->list.next;
 402
 403         while (head == &t->iphash[st->bucket]) {
 404                 if (++st->bucket >= ip_list_hash_size)
 405                         return NULL;
 406                 head = t->iphash[st->bucket].next;
 407         }
 408         (*pos)++;
 409         return list_entry(head, struct recent_entry, list);
 410 }
 411
 412 static void recent_seq_stop(struct seq_file *s, void *v)
 413         __releases(recent_lock)
 414 {
 415         spin_unlock_bh(&recent_lock);
 416 }
 417
 418 static int recent_seq_show(struct seq_file *seq, void *v)
 419 {
 420         const struct recent_entry *e = v;
 421         unsigned int i;
 422
 423         i = (e->index - 1) % ip_pkt_list_tot;
 424         if (e->family == NFPROTO_IPV4)
 425                 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
 426                            &e->addr.ip, e->ttl, e->stamps[i], e->index);
 427         else
 428                 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
 429                            &e->addr.in6, e->ttl, e->stamps[i], e->index);
 430         for (i = 0; i < e->nstamps; i++)
 431                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 432         seq_printf(seq, "\n");
 433         return 0;
 434 }
 435
 436 static const struct seq_operations recent_seq_ops = {
 437         .start          = recent_seq_start,
 438         .next           = recent_seq_next,
 439         .stop           = recent_seq_stop,
 440         .show           = recent_seq_show,
 441 };
 442
 443 static int recent_seq_open(struct inode *inode, struct file *file)
 444 {
 445         struct proc_dir_entry *pde = PDE(inode);
 446         struct recent_iter_state *st;
 447
 448         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 449         if (st == NULL)
 450                 return -ENOMEM;
 451
 452         st->table    = pde->data;
 453         return 0;
 454 }
 455
 456 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 457 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 458 {
 459         static bool warned_of_old;
 460
 461         if (unlikely(!warned_of_old)) {
 462                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 463                        " is deprecated; use /proc/net/xt_recent.\n");
 464                 warned_of_old = true;
 465         }
 466         return recent_seq_open(inode, filp);
 467 }
 468
 469 static ssize_t recent_old_proc_write(struct file *file,
 470                                      const char __user *input,
 471                                      size_t size, loff_t *loff)
 472 {
 473         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 474         struct recent_table *t = pde->data;
 475         struct recent_entry *e;
 476         char buf[sizeof("+255.255.255.255")], *c = buf;
 477         union nf_inet_addr addr = {};
 478         int add;
 479
 480         if (size > sizeof(buf))
 481                 size = sizeof(buf);
 482         if (copy_from_user(buf, input, size))
 483                 return -EFAULT;
 484
 485         while (isspace(*c))
 486                 c++;
 487
 488         if (size - (c - buf) < 5)
 489                 return c - buf;
 490         if (!strncmp(c, "clear", 5)) {
 491                 c += 5;
 492                 spin_lock_bh(&recent_lock);
 493                 recent_table_flush(t);
 494                 spin_unlock_bh(&recent_lock);
 495                 return c - buf;
 496         }
 497
 498         switch (*c) {
 499         case '-':
 500                 add = 0;
 501                 c++;
 502                 break;
 503         case '+':
 504                 c++;
 505         default:
 506                 add = 1;
 507                 break;
 508         }
 509         addr.ip = in_aton(c);
 510
 511         spin_lock_bh(&recent_lock);
 512         e = recent_entry_lookup(t, &addr, NFPROTO_IPV4, 0);
 513         if (e == NULL) {
 514                 if (add)
 515                         recent_entry_init(t, &addr, NFPROTO_IPV4, 0);
 516         } else {
 517                 if (add)
 518                         recent_entry_update(t, e);
 519                 else
 520                         recent_entry_remove(t, e);
 521         }
 522         spin_unlock_bh(&recent_lock);
 523         return size;
 524 }
 525
 526 static const struct file_operations recent_old_fops = {
 527         .open           = recent_old_seq_open,
 528         .read           = seq_read,
 529         .write          = recent_old_proc_write,
 530         .release        = seq_release_private,
 531         .owner          = THIS_MODULE,
 532 };
 533 #endif
 534
 535 static ssize_t
 536 recent_mt_proc_write(struct file *file, const char __user *input,
 537                      size_t size, loff_t *loff)
 538 {
 539         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 540         struct recent_table *t = pde->data;
 541         struct recent_entry *e;
 542         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 543         const char *c = buf;
 544         union nf_inet_addr addr = {};
 545         u_int16_t family;
 546         bool add, succ;
 547
 548         if (size == 0)
 549                 return 0;
 550         if (size > sizeof(buf))
 551                 size = sizeof(buf);
 552         if (copy_from_user(buf, input, size) != 0)
 553                 return -EFAULT;
 554
 555         /* Strict protocol! */
 556         if (*loff != 0)
 557                 return -ESPIPE;
 558         switch (*c) {
 559         case '/': /* flush table */
 560                 spin_lock_bh(&recent_lock);
 561                 recent_table_flush(t);
 562                 spin_unlock_bh(&recent_lock);
 563                 return size;
 564         case '-': /* remove address */
 565                 add = false;
 566                 break;
 567         case '+': /* add address */
 568                 add = true;
 569                 break;
 570         default:
 571                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 572                 return -EINVAL;
 573         }
 574
 575         ++c;
 576         --size;
 577         if (strnchr(c, size, ':') != NULL) {
 578                 family = NFPROTO_IPV6;
 579                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 580         } else {
 581                 family = NFPROTO_IPV4;
 582                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 583         }
 584
 585         if (!succ) {
 586                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 587                        "to procfs\n");
 588                 return -EINVAL;
 589         }
 590
 591         spin_lock_bh(&recent_lock);
 592         e = recent_entry_lookup(t, &addr, family, 0);
 593         if (e == NULL) {
 594                 if (add)
 595                         recent_entry_init(t, &addr, family, 0);
 596         } else {
 597                 if (add)
 598                         recent_entry_update(t, e);
 599                 else
 600                         recent_entry_remove(t, e);
 601         }
 602         spin_unlock_bh(&recent_lock);
 603         /* Note we removed one above */
 604         *loff += size + 1;
 605         return size + 1;
 606 }
 607
 608 static const struct file_operations recent_mt_fops = {
 609         .open    = recent_seq_open,
 610         .read    = seq_read,
 611         .write   = recent_mt_proc_write,
 612         .release = seq_release_private,
 613         .owner   = THIS_MODULE,
 614 };
 615 #endif /* CONFIG_PROC_FS */
 616
 617 static struct xt_match recent_mt_reg[] __read_mostly = {
 618         {
 619                 .name       = "recent",
 620                 .revision   = 0,
 621                 .family     = NFPROTO_IPV4,
 622                 .match      = recent_mt,
 623                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 624                 .checkentry = recent_mt_check,
 625                 .destroy    = recent_mt_destroy,
 626                 .me         = THIS_MODULE,
 627         },
 628         {
 629                 .name       = "recent",
 630                 .revision   = 0,
 631                 .family     = NFPROTO_IPV6,
 632                 .match      = recent_mt,
 633                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 634                 .checkentry = recent_mt_check,
 635                 .destroy    = recent_mt_destroy,
 636                 .me         = THIS_MODULE,
 637         },
 638 };
 639
 640 static int __init recent_mt_init(void)
 641 {
 642         int err;
 643
 644         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 645                 return -EINVAL;
 646         ip_list_hash_size = 1 << fls(ip_list_tot);
 647
 648         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 649 #ifdef CONFIG_PROC_FS
 650         if (err)
 651                 return err;
 652         recent_proc_dir = proc_mkdir("xt_recent", init_net.proc_net);
 653         if (recent_proc_dir == NULL) {
 654                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 655                 err = -ENOMEM;
 656         }
 657 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 658         if (err < 0)
 659                 return err;
 660         proc_old_dir = proc_mkdir("ipt_recent", init_net.proc_net);
 661         if (proc_old_dir == NULL) {
 662                 remove_proc_entry("xt_recent", init_net.proc_net);
 663                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 664                 err = -ENOMEM;
 665         }
 666 #endif
 667 #endif
 668         return err;
 669 }
 670
 671 static void __exit recent_mt_exit(void)
 672 {
 673         BUG_ON(!list_empty(&tables));
 674         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 675 #ifdef CONFIG_PROC_FS
 676 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 677         remove_proc_entry("ipt_recent", init_net.proc_net);
 678 #endif
 679         remove_proc_entry("xt_recent", init_net.proc_net);
 680 #endif
 681 }
 682
 683 module_init(recent_mt_init);
 684 module_exit(recent_mt_exit);