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 #ifdef CONFIG_PROC_FS
  76         struct proc_dir_entry   *proc_old, *proc;
  77 #endif
  78         unsigned int            refcnt;
  79         unsigned int            entries;
  80         struct list_head        lru_list;
  81         struct list_head        iphash[0];
  82 };
  83
  84 static LIST_HEAD(tables);
  85 static DEFINE_SPINLOCK(recent_lock);
  86 static DEFINE_MUTEX(recent_mutex);
  87
  88 #ifdef CONFIG_PROC_FS
  89 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  90 static struct proc_dir_entry *proc_old_dir;
  91 #endif
  92 static struct proc_dir_entry *recent_proc_dir;
  93 static const struct file_operations recent_old_fops, recent_mt_fops;
  94 #endif
  95
  96 static u_int32_t hash_rnd;
  97 static bool hash_rnd_initted;
  98
  99 static unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
 100 {
 101         if (!hash_rnd_initted) {
 102                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 103                 hash_rnd_initted = true;
 104         }
 105         return jhash_1word((__force u32)addr->ip, hash_rnd) &
 106                (ip_list_hash_size - 1);
 107 }
 108
 109 static unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
 110 {
 111         if (!hash_rnd_initted) {
 112                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 113                 hash_rnd_initted = true;
 114         }
 115         return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
 116                (ip_list_hash_size - 1);
 117 }
 118
 119 static struct recent_entry *
 120 recent_entry_lookup(const struct recent_table *table,
 121                     const union nf_inet_addr *addrp, u_int16_t family,
 122                     u_int8_t ttl)
 123 {
 124         struct recent_entry *e;
 125         unsigned int h;
 126
 127         if (family == NFPROTO_IPV4)
 128                 h = recent_entry_hash4(addrp);
 129         else
 130                 h = recent_entry_hash6(addrp);
 131
 132         list_for_each_entry(e, &table->iphash[h], list)
 133                 if (e->family == family &&
 134                     memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
 135                     (ttl == e->ttl || ttl == 0 || e->ttl == 0))
 136                         return e;
 137         return NULL;
 138 }
 139
 140 static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
 141 {
 142         list_del(&e->list);
 143         list_del(&e->lru_list);
 144         kfree(e);
 145         t->entries--;
 146 }
 147
 148 static struct recent_entry *
 149 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 150                   u_int16_t family, u_int8_t ttl)
 151 {
 152         struct recent_entry *e;
 153
 154         if (t->entries >= ip_list_tot) {
 155                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 156                 recent_entry_remove(t, e);
 157         }
 158         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 159                     GFP_ATOMIC);
 160         if (e == NULL)
 161                 return NULL;
 162         memcpy(&e->addr, addr, sizeof(e->addr));
 163         e->ttl       = ttl;
 164         e->stamps[0] = jiffies;
 165         e->nstamps   = 1;
 166         e->index     = 1;
 167         e->family    = family;
 168         if (family == NFPROTO_IPV4)
 169                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 170         else
 171                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 172         list_add_tail(&e->lru_list, &t->lru_list);
 173         t->entries++;
 174         return e;
 175 }
 176
 177 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 178 {
 179         e->stamps[e->index++] = jiffies;
 180         if (e->index > e->nstamps)
 181                 e->nstamps = e->index;
 182         e->index %= ip_pkt_list_tot;
 183         list_move_tail(&e->lru_list, &t->lru_list);
 184 }
 185
 186 static struct recent_table *recent_table_lookup(const char *name)
 187 {
 188         struct recent_table *t;
 189
 190         list_for_each_entry(t, &tables, list)
 191                 if (!strcmp(t->name, name))
 192                         return t;
 193         return NULL;
 194 }
 195
 196 static void recent_table_flush(struct recent_table *t)
 197 {
 198         struct recent_entry *e, *next;
 199         unsigned int i;
 200
 201         for (i = 0; i < ip_list_hash_size; i++)
 202                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 203                         recent_entry_remove(t, e);
 204 }
 205
 206 static bool
 207 recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 208 {
 209         const struct xt_recent_mtinfo *info = par->matchinfo;
 210         struct recent_table *t;
 211         struct recent_entry *e;
 212         union nf_inet_addr addr = {};
 213         u_int8_t ttl;
 214         bool ret = info->invert;
 215
 216         if (par->match->family == NFPROTO_IPV4) {
 217                 const struct iphdr *iph = ip_hdr(skb);
 218
 219                 if (info->side == XT_RECENT_DEST)
 220                         addr.ip = iph->daddr;
 221                 else
 222                         addr.ip = iph->saddr;
 223
 224                 ttl = iph->ttl;
 225         } else {
 226                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 227
 228                 if (info->side == XT_RECENT_DEST)
 229                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 230                 else
 231                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 232
 233                 ttl = iph->hop_limit;
 234         }
 235
 236         /* use TTL as seen before forwarding */
 237         if (par->out != NULL && skb->sk == NULL)
 238                 ttl++;
 239
 240         spin_lock_bh(&recent_lock);
 241         t = recent_table_lookup(info->name);
 242         e = recent_entry_lookup(t, &addr, par->match->family,
 243                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 244         if (e == NULL) {
 245                 if (!(info->check_set & XT_RECENT_SET))
 246                         goto out;
 247                 e = recent_entry_init(t, &addr, par->match->family, ttl);
 248                 if (e == NULL)
 249                         *par->hotdrop = true;
 250                 ret = !ret;
 251                 goto out;
 252         }
 253
 254         if (info->check_set & XT_RECENT_SET)
 255                 ret = !ret;
 256         else if (info->check_set & XT_RECENT_REMOVE) {
 257                 recent_entry_remove(t, e);
 258                 ret = !ret;
 259         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 260                 unsigned long time = jiffies - info->seconds * HZ;
 261                 unsigned int i, hits = 0;
 262
 263                 for (i = 0; i < e->nstamps; i++) {
 264                         if (info->seconds && time_after(time, e->stamps[i]))
 265                                 continue;
 266                         if (++hits >= info->hit_count) {
 267                                 ret = !ret;
 268                                 break;
 269                         }
 270                 }
 271         }
 272
 273         if (info->check_set & XT_RECENT_SET ||
 274             (info->check_set & XT_RECENT_UPDATE && ret)) {
 275                 recent_entry_update(t, e);
 276                 e->ttl = ttl;
 277         }
 278 out:
 279         spin_unlock_bh(&recent_lock);
 280         return ret;
 281 }
 282
 283 static bool recent_mt_check(const struct xt_mtchk_param *par)
 284 {
 285         const struct xt_recent_mtinfo *info = par->matchinfo;
 286         struct recent_table *t;
 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         t->proc = proc_create_data(t->name, ip_list_perms, recent_proc_dir,
 322                   &recent_mt_fops, t);
 323         if (t->proc == NULL) {
 324                 kfree(t);
 325                 goto out;
 326         }
 327 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 328         t->proc_old = proc_create_data(t->name, ip_list_perms, proc_old_dir,
 329                       &recent_old_fops, t);
 330         if (t->proc_old == NULL) {
 331                 remove_proc_entry(t->name, proc_old_dir);
 332                 kfree(t);
 333                 goto out;
 334         }
 335         t->proc_old->uid   = ip_list_uid;
 336         t->proc_old->gid   = ip_list_gid;
 337 #endif
 338         t->proc->uid       = ip_list_uid;
 339         t->proc->gid       = ip_list_gid;
 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=" NIPQUAD_FMT " ttl: %u last_seen: %lu "
 426                            "oldest_pkt: %u", NIPQUAD(e->addr.ip), e->ttl,
 427                            e->stamps[i], e->index);
 428         else
 429                 seq_printf(seq, "src=" NIP6_FMT " ttl: %u last_seen: %lu "
 430                            "oldest_pkt: %u", NIP6(e->addr.in6), e->ttl,
 431                            e->stamps[i], e->index);
 432         for (i = 0; i < e->nstamps; i++)
 433                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 434         seq_printf(seq, "\n");
 435         return 0;
 436 }
 437
 438 static const struct seq_operations recent_seq_ops = {
 439         .start          = recent_seq_start,
 440         .next           = recent_seq_next,
 441         .stop           = recent_seq_stop,
 442         .show           = recent_seq_show,
 443 };
 444
 445 static int recent_seq_open(struct inode *inode, struct file *file)
 446 {
 447         struct proc_dir_entry *pde = PDE(inode);
 448         struct recent_iter_state *st;
 449
 450         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 451         if (st == NULL)
 452                 return -ENOMEM;
 453
 454         st->table    = pde->data;
 455         return 0;
 456 }
 457
 458 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 459 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 460 {
 461         static bool warned_of_old;
 462
 463         if (unlikely(!warned_of_old)) {
 464                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 465                        " is deprecated; use /proc/net/xt_recent.\n");
 466                 warned_of_old = true;
 467         }
 468         return recent_seq_open(inode, filp);
 469 }
 470
 471 static ssize_t recent_old_proc_write(struct file *file,
 472                                      const char __user *input,
 473                                      size_t size, loff_t *loff)
 474 {
 475         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 476         struct recent_table *t = pde->data;
 477         struct recent_entry *e;
 478         char buf[sizeof("+255.255.255.255")], *c = buf;
 479         __be32 addr;
 480         int add;
 481
 482         if (size > sizeof(buf))
 483                 size = sizeof(buf);
 484         if (copy_from_user(buf, input, size))
 485                 return -EFAULT;
 486
 487         while (isspace(*c))
 488                 c++;
 489
 490         if (size - (c - buf) < 5)
 491                 return c - buf;
 492         if (!strncmp(c, "clear", 5)) {
 493                 c += 5;
 494                 spin_lock_bh(&recent_lock);
 495                 recent_table_flush(t);
 496                 spin_unlock_bh(&recent_lock);
 497                 return c - buf;
 498         }
 499
 500         switch (*c) {
 501         case '-':
 502                 add = 0;
 503                 c++;
 504                 break;
 505         case '+':
 506                 c++;
 507         default:
 508                 add = 1;
 509                 break;
 510         }
 511         addr = in_aton(c);
 512
 513         spin_lock_bh(&recent_lock);
 514         e = recent_entry_lookup(t, (const void *)&addr, NFPROTO_IPV4, 0);
 515         if (e == NULL) {
 516                 if (add)
 517                         recent_entry_init(t, (const void *)&addr,
 518                                           NFPROTO_IPV4, 0);
 519         } else {
 520                 if (add)
 521                         recent_entry_update(t, e);
 522                 else
 523                         recent_entry_remove(t, e);
 524         }
 525         spin_unlock_bh(&recent_lock);
 526         return size;
 527 }
 528
 529 static const struct file_operations recent_old_fops = {
 530         .open           = recent_old_seq_open,
 531         .read           = seq_read,
 532         .write          = recent_old_proc_write,
 533         .release        = seq_release_private,
 534         .owner          = THIS_MODULE,
 535 };
 536 #endif
 537
 538 static ssize_t
 539 recent_mt_proc_write(struct file *file, const char __user *input,
 540                      size_t size, loff_t *loff)
 541 {
 542         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 543         struct recent_table *t = pde->data;
 544         struct recent_entry *e;
 545         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 546         const char *c = buf;
 547         union nf_inet_addr addr;
 548         u_int16_t family;
 549         bool add, succ;
 550
 551         if (size == 0)
 552                 return 0;
 553         if (size > sizeof(buf))
 554                 size = sizeof(buf);
 555         if (copy_from_user(buf, input, size) != 0)
 556                 return -EFAULT;
 557
 558         /* Strict protocol! */
 559         if (*loff != 0)
 560                 return -ESPIPE;
 561         switch (*c) {
 562         case '/': /* flush table */
 563                 spin_lock_bh(&recent_lock);
 564                 recent_table_flush(t);
 565                 spin_unlock_bh(&recent_lock);
 566                 return size;
 567         case '-': /* remove address */
 568                 add = false;
 569                 break;
 570         case '+': /* add address */
 571                 add = true;
 572                 break;
 573         default:
 574                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 575                 return -EINVAL;
 576         }
 577
 578         ++c;
 579         --size;
 580         if (strnchr(c, size, ':') != NULL) {
 581                 family = NFPROTO_IPV6;
 582                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 583         } else {
 584                 family = NFPROTO_IPV4;
 585                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 586         }
 587
 588         if (!succ) {
 589                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 590                        "to procfs\n");
 591                 return -EINVAL;
 592         }
 593
 594         spin_lock_bh(&recent_lock);
 595         e = recent_entry_lookup(t, &addr, family, 0);
 596         if (e == NULL) {
 597                 if (add)
 598                         recent_entry_init(t, &addr, family, 0);
 599         } else {
 600                 if (add)
 601                         recent_entry_update(t, e);
 602                 else
 603                         recent_entry_remove(t, e);
 604         }
 605         spin_unlock_bh(&recent_lock);
 606         /* Note we removed one above */
 607         *loff += size + 1;
 608         return size + 1;
 609 }
 610
 611 static const struct file_operations recent_mt_fops = {
 612         .open    = recent_seq_open,
 613         .read    = seq_read,
 614         .write   = recent_mt_proc_write,
 615         .release = seq_release_private,
 616         .owner   = THIS_MODULE,
 617 };
 618 #endif /* CONFIG_PROC_FS */
 619
 620 static struct xt_match recent_mt_reg[] __read_mostly = {
 621         {
 622                 .name       = "recent",
 623                 .revision   = 0,
 624                 .family     = NFPROTO_IPV4,
 625                 .match      = recent_mt,
 626                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 627                 .checkentry = recent_mt_check,
 628                 .destroy    = recent_mt_destroy,
 629                 .me         = THIS_MODULE,
 630         },
 631         {
 632                 .name       = "recent",
 633                 .revision   = 0,
 634                 .family     = NFPROTO_IPV6,
 635                 .match      = recent_mt,
 636                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 637                 .checkentry = recent_mt_check,
 638                 .destroy    = recent_mt_destroy,
 639                 .me         = THIS_MODULE,
 640         },
 641 };
 642
 643 static int __init recent_mt_init(void)
 644 {
 645         int err;
 646
 647         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 648                 return -EINVAL;
 649         ip_list_hash_size = 1 << fls(ip_list_tot);
 650
 651         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 652 #ifdef CONFIG_PROC_FS
 653         if (err)
 654                 return err;
 655         recent_proc_dir = proc_mkdir("xt_recent", init_net.proc_net);
 656         if (recent_proc_dir == NULL) {
 657                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 658                 err = -ENOMEM;
 659         }
 660 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 661         if (err < 0)
 662                 return err;
 663         proc_old_dir = proc_mkdir("ipt_recent", init_net.proc_net);
 664         if (proc_old_dir == NULL) {
 665                 remove_proc_entry("xt_recent", init_net.proc_net);
 666                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 667                 err = -ENOMEM;
 668         }
 669 #endif
 670 #endif
 671         return err;
 672 }
 673
 674 static void __exit recent_mt_exit(void)
 675 {
 676         BUG_ON(!list_empty(&tables));
 677         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 678 #ifdef CONFIG_PROC_FS
 679 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 680         remove_proc_entry("ipt_recent", init_net.proc_net);
 681 #endif
 682         remove_proc_entry("xt_recent", init_net.proc_net);
 683 #endif
 684 }
 685
 686 module_init(recent_mt_init);
 687 module_exit(recent_mt_exit);