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 <linux/slab.h>
  31 #include <net/net_namespace.h>
  32 #include <net/netns/generic.h>
  33
  34 #include <linux/netfilter/x_tables.h>
  35 #include <linux/netfilter/xt_recent.h>
  36
  37 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  38 MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
  39 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4");
  40 MODULE_LICENSE("GPL");
  41 MODULE_ALIAS("ipt_recent");
  42 MODULE_ALIAS("ip6t_recent");
  43
  44 static unsigned int ip_list_tot = 100;
  45 static unsigned int ip_pkt_list_tot = 20;
  46 static unsigned int ip_list_hash_size = 0;
  47 static unsigned int ip_list_perms = 0644;
  48 static unsigned int ip_list_uid = 0;
  49 static unsigned int ip_list_gid = 0;
  50 module_param(ip_list_tot, uint, 0400);
  51 module_param(ip_pkt_list_tot, uint, 0400);
  52 module_param(ip_list_hash_size, uint, 0400);
  53 module_param(ip_list_perms, uint, 0400);
  54 module_param(ip_list_uid, uint, 0400);
  55 module_param(ip_list_gid, uint, 0400);
  56 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  57 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
  58 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
  59 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
  60 MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/xt_recent/* files");
  61 MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files");
  62
  63 struct recent_entry {
  64         struct list_head        list;
  65         struct list_head        lru_list;
  66         union nf_inet_addr      addr;
  67         u_int16_t               family;
  68         u_int8_t                ttl;
  69         u_int8_t                index;
  70         u_int16_t               nstamps;
  71         unsigned long           stamps[0];
  72 };
  73
  74 struct recent_table {
  75         struct list_head        list;
  76         char                    name[XT_RECENT_NAME_LEN];
  77         unsigned int            refcnt;
  78         unsigned int            entries;
  79         struct list_head        lru_list;
  80         struct list_head        iphash[0];
  81 };
  82
  83 struct recent_net {
  84         struct list_head        tables;
  85 #ifdef CONFIG_PROC_FS
  86         struct proc_dir_entry   *xt_recent;
  87 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  88         struct proc_dir_entry   *ipt_recent;
  89 #endif
  90 #endif
  91 };
  92
  93 static int recent_net_id;
  94 static inline struct recent_net *recent_pernet(struct net *net)
  95 {
  96         return net_generic(net, recent_net_id);
  97 }
  98
  99 static DEFINE_SPINLOCK(recent_lock);
 100 static DEFINE_MUTEX(recent_mutex);
 101
 102 #ifdef CONFIG_PROC_FS
 103 static const struct file_operations recent_old_fops, recent_mt_fops;
 104 #endif
 105
 106 static u_int32_t hash_rnd __read_mostly;
 107 static bool hash_rnd_inited __read_mostly;
 108
 109 static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
 110 {
 111         return jhash_1word((__force u32)addr->ip, hash_rnd) &
 112                (ip_list_hash_size - 1);
 113 }
 114
 115 static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
 116 {
 117         return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
 118                (ip_list_hash_size - 1);
 119 }
 120
 121 static struct recent_entry *
 122 recent_entry_lookup(const struct recent_table *table,
 123                     const union nf_inet_addr *addrp, u_int16_t family,
 124                     u_int8_t ttl)
 125 {
 126         struct recent_entry *e;
 127         unsigned int h;
 128
 129         if (family == NFPROTO_IPV4)
 130                 h = recent_entry_hash4(addrp);
 131         else
 132                 h = recent_entry_hash6(addrp);
 133
 134         list_for_each_entry(e, &table->iphash[h], list)
 135                 if (e->family == family &&
 136                     memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
 137                     (ttl == e->ttl || ttl == 0 || e->ttl == 0))
 138                         return e;
 139         return NULL;
 140 }
 141
 142 static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
 143 {
 144         list_del(&e->list);
 145         list_del(&e->lru_list);
 146         kfree(e);
 147         t->entries--;
 148 }
 149
 150 static struct recent_entry *
 151 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 152                   u_int16_t family, u_int8_t ttl)
 153 {
 154         struct recent_entry *e;
 155
 156         if (t->entries >= ip_list_tot) {
 157                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 158                 recent_entry_remove(t, e);
 159         }
 160         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 161                     GFP_ATOMIC);
 162         if (e == NULL)
 163                 return NULL;
 164         memcpy(&e->addr, addr, sizeof(e->addr));
 165         e->ttl       = ttl;
 166         e->stamps[0] = jiffies;
 167         e->nstamps   = 1;
 168         e->index     = 1;
 169         e->family    = family;
 170         if (family == NFPROTO_IPV4)
 171                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 172         else
 173                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 174         list_add_tail(&e->lru_list, &t->lru_list);
 175         t->entries++;
 176         return e;
 177 }
 178
 179 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 180 {
 181         e->index %= ip_pkt_list_tot;
 182         e->stamps[e->index++] = jiffies;
 183         if (e->index > e->nstamps)
 184                 e->nstamps = e->index;
 185         list_move_tail(&e->lru_list, &t->lru_list);
 186 }
 187
 188 static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
 189                                                 const char *name)
 190 {
 191         struct recent_table *t;
 192
 193         list_for_each_entry(t, &recent_net->tables, list)
 194                 if (!strcmp(t->name, name))
 195                         return t;
 196         return NULL;
 197 }
 198
 199 static void recent_table_flush(struct recent_table *t)
 200 {
 201         struct recent_entry *e, *next;
 202         unsigned int i;
 203
 204         for (i = 0; i < ip_list_hash_size; i++)
 205                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 206                         recent_entry_remove(t, e);
 207 }
 208
 209 static bool
 210 recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 211 {
 212         struct net *net = dev_net(par->in ? par->in : par->out);
 213         struct recent_net *recent_net = recent_pernet(net);
 214         const struct xt_recent_mtinfo *info = par->matchinfo;
 215         struct recent_table *t;
 216         struct recent_entry *e;
 217         union nf_inet_addr addr = {};
 218         u_int8_t ttl;
 219         bool ret = info->invert;
 220
 221         if (par->match->family == NFPROTO_IPV4) {
 222                 const struct iphdr *iph = ip_hdr(skb);
 223
 224                 if (info->side == XT_RECENT_DEST)
 225                         addr.ip = iph->daddr;
 226                 else
 227                         addr.ip = iph->saddr;
 228
 229                 ttl = iph->ttl;
 230         } else {
 231                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 232
 233                 if (info->side == XT_RECENT_DEST)
 234                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 235                 else
 236                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 237
 238                 ttl = iph->hop_limit;
 239         }
 240
 241         /* use TTL as seen before forwarding */
 242         if (par->out != NULL && skb->sk == NULL)
 243                 ttl++;
 244
 245         spin_lock_bh(&recent_lock);
 246         t = recent_table_lookup(recent_net, info->name);
 247         e = recent_entry_lookup(t, &addr, par->match->family,
 248                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 249         if (e == NULL) {
 250                 if (!(info->check_set & XT_RECENT_SET))
 251                         goto out;
 252                 e = recent_entry_init(t, &addr, par->match->family, ttl);
 253                 if (e == NULL)
 254                         *par->hotdrop = true;
 255                 ret = !ret;
 256                 goto out;
 257         }
 258
 259         if (info->check_set & XT_RECENT_SET)
 260                 ret = !ret;
 261         else if (info->check_set & XT_RECENT_REMOVE) {
 262                 recent_entry_remove(t, e);
 263                 ret = !ret;
 264         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 265                 unsigned long time = jiffies - info->seconds * HZ;
 266                 unsigned int i, hits = 0;
 267
 268                 for (i = 0; i < e->nstamps; i++) {
 269                         if (info->seconds && time_after(time, e->stamps[i]))
 270                                 continue;
 271                         if (!info->hit_count || ++hits >= info->hit_count) {
 272                                 ret = !ret;
 273                                 break;
 274                         }
 275                 }
 276         }
 277
 278         if (info->check_set & XT_RECENT_SET ||
 279             (info->check_set & XT_RECENT_UPDATE && ret)) {
 280                 recent_entry_update(t, e);
 281                 e->ttl = ttl;
 282         }
 283 out:
 284         spin_unlock_bh(&recent_lock);
 285         return ret;
 286 }
 287
 288 static bool recent_mt_check(const struct xt_mtchk_param *par)
 289 {
 290         struct recent_net *recent_net = recent_pernet(par->net);
 291         const struct xt_recent_mtinfo *info = par->matchinfo;
 292         struct recent_table *t;
 293 #ifdef CONFIG_PROC_FS
 294         struct proc_dir_entry *pde;
 295 #endif
 296         unsigned i;
 297         bool ret = false;
 298
 299         if (unlikely(!hash_rnd_inited)) {
 300                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 301                 hash_rnd_inited = true;
 302         }
 303         if (hweight8(info->check_set &
 304                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 305                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 306                 return false;
 307         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 308             (info->seconds || info->hit_count))
 309                 return false;
 310         if (info->hit_count > ip_pkt_list_tot) {
 311                 pr_info(KBUILD_MODNAME ": hitcount (%u) is larger than "
 312                         "packets to be remembered (%u)\n",
 313                         info->hit_count, ip_pkt_list_tot);
 314                 return false;
 315         }
 316         if (info->name[0] == '\0' ||
 317             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 318                 return false;
 319
 320         mutex_lock(&recent_mutex);
 321         t = recent_table_lookup(recent_net, info->name);
 322         if (t != NULL) {
 323                 t->refcnt++;
 324                 ret = true;
 325                 goto out;
 326         }
 327
 328         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
 329                     GFP_KERNEL);
 330         if (t == NULL)
 331                 goto out;
 332         t->refcnt = 1;
 333         strcpy(t->name, info->name);
 334         INIT_LIST_HEAD(&t->lru_list);
 335         for (i = 0; i < ip_list_hash_size; i++)
 336                 INIT_LIST_HEAD(&t->iphash[i]);
 337 #ifdef CONFIG_PROC_FS
 338         pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
 339                   &recent_mt_fops, t);
 340         if (pde == NULL) {
 341                 kfree(t);
 342                 goto out;
 343         }
 344         pde->uid = ip_list_uid;
 345         pde->gid = ip_list_gid;
 346 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 347         pde = proc_create_data(t->name, ip_list_perms, recent_net->ipt_recent,
 348                       &recent_old_fops, t);
 349         if (pde == NULL) {
 350                 remove_proc_entry(t->name, recent_net->xt_recent);
 351                 kfree(t);
 352                 goto out;
 353         }
 354         pde->uid = ip_list_uid;
 355         pde->gid = ip_list_gid;
 356 #endif
 357 #endif
 358         spin_lock_bh(&recent_lock);
 359         list_add_tail(&t->list, &recent_net->tables);
 360         spin_unlock_bh(&recent_lock);
 361         ret = true;
 362 out:
 363         mutex_unlock(&recent_mutex);
 364         return ret;
 365 }
 366
 367 static void recent_mt_destroy(const struct xt_mtdtor_param *par)
 368 {
 369         struct recent_net *recent_net = recent_pernet(par->net);
 370         const struct xt_recent_mtinfo *info = par->matchinfo;
 371         struct recent_table *t;
 372
 373         mutex_lock(&recent_mutex);
 374         t = recent_table_lookup(recent_net, info->name);
 375         if (--t->refcnt == 0) {
 376                 spin_lock_bh(&recent_lock);
 377                 list_del(&t->list);
 378                 spin_unlock_bh(&recent_lock);
 379 #ifdef CONFIG_PROC_FS
 380 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 381                 remove_proc_entry(t->name, recent_net->ipt_recent);
 382 #endif
 383                 remove_proc_entry(t->name, recent_net->xt_recent);
 384 #endif
 385                 recent_table_flush(t);
 386                 kfree(t);
 387         }
 388         mutex_unlock(&recent_mutex);
 389 }
 390
 391 #ifdef CONFIG_PROC_FS
 392 struct recent_iter_state {
 393         const struct recent_table *table;
 394         unsigned int            bucket;
 395 };
 396
 397 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 398         __acquires(recent_lock)
 399 {
 400         struct recent_iter_state *st = seq->private;
 401         const struct recent_table *t = st->table;
 402         struct recent_entry *e;
 403         loff_t p = *pos;
 404
 405         spin_lock_bh(&recent_lock);
 406
 407         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
 408                 list_for_each_entry(e, &t->iphash[st->bucket], list)
 409                         if (p-- == 0)
 410                                 return e;
 411         return NULL;
 412 }
 413
 414 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 415 {
 416         struct recent_iter_state *st = seq->private;
 417         const struct recent_table *t = st->table;
 418         const struct recent_entry *e = v;
 419         const struct list_head *head = e->list.next;
 420
 421         while (head == &t->iphash[st->bucket]) {
 422                 if (++st->bucket >= ip_list_hash_size)
 423                         return NULL;
 424                 head = t->iphash[st->bucket].next;
 425         }
 426         (*pos)++;
 427         return list_entry(head, struct recent_entry, list);
 428 }
 429
 430 static void recent_seq_stop(struct seq_file *s, void *v)
 431         __releases(recent_lock)
 432 {
 433         spin_unlock_bh(&recent_lock);
 434 }
 435
 436 static int recent_seq_show(struct seq_file *seq, void *v)
 437 {
 438         const struct recent_entry *e = v;
 439         unsigned int i;
 440
 441         i = (e->index - 1) % ip_pkt_list_tot;
 442         if (e->family == NFPROTO_IPV4)
 443                 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
 444                            &e->addr.ip, e->ttl, e->stamps[i], e->index);
 445         else
 446                 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
 447                            &e->addr.in6, e->ttl, e->stamps[i], e->index);
 448         for (i = 0; i < e->nstamps; i++)
 449                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 450         seq_printf(seq, "\n");
 451         return 0;
 452 }
 453
 454 static const struct seq_operations recent_seq_ops = {
 455         .start          = recent_seq_start,
 456         .next           = recent_seq_next,
 457         .stop           = recent_seq_stop,
 458         .show           = recent_seq_show,
 459 };
 460
 461 static int recent_seq_open(struct inode *inode, struct file *file)
 462 {
 463         struct proc_dir_entry *pde = PDE(inode);
 464         struct recent_iter_state *st;
 465
 466         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 467         if (st == NULL)
 468                 return -ENOMEM;
 469
 470         st->table    = pde->data;
 471         return 0;
 472 }
 473
 474 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 475 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 476 {
 477         static bool warned_of_old;
 478
 479         if (unlikely(!warned_of_old)) {
 480                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 481                        " is deprecated; use /proc/net/xt_recent.\n");
 482                 warned_of_old = true;
 483         }
 484         return recent_seq_open(inode, filp);
 485 }
 486
 487 static ssize_t recent_old_proc_write(struct file *file,
 488                                      const char __user *input,
 489                                      size_t size, loff_t *loff)
 490 {
 491         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 492         struct recent_table *t = pde->data;
 493         struct recent_entry *e;
 494         char buf[sizeof("+255.255.255.255")], *c = buf;
 495         union nf_inet_addr addr = {};
 496         int add;
 497
 498         if (size > sizeof(buf))
 499                 size = sizeof(buf);
 500         if (copy_from_user(buf, input, size))
 501                 return -EFAULT;
 502
 503         c = skip_spaces(c);
 504
 505         if (size - (c - buf) < 5)
 506                 return c - buf;
 507         if (!strncmp(c, "clear", 5)) {
 508                 c += 5;
 509                 spin_lock_bh(&recent_lock);
 510                 recent_table_flush(t);
 511                 spin_unlock_bh(&recent_lock);
 512                 return c - buf;
 513         }
 514
 515         switch (*c) {
 516         case '-':
 517                 add = 0;
 518                 c++;
 519                 break;
 520         case '+':
 521                 c++;
 522         default:
 523                 add = 1;
 524                 break;
 525         }
 526         addr.ip = in_aton(c);
 527
 528         spin_lock_bh(&recent_lock);
 529         e = recent_entry_lookup(t, &addr, NFPROTO_IPV4, 0);
 530         if (e == NULL) {
 531                 if (add)
 532                         recent_entry_init(t, &addr, NFPROTO_IPV4, 0);
 533         } else {
 534                 if (add)
 535                         recent_entry_update(t, e);
 536                 else
 537                         recent_entry_remove(t, e);
 538         }
 539         spin_unlock_bh(&recent_lock);
 540         return size;
 541 }
 542
 543 static const struct file_operations recent_old_fops = {
 544         .open           = recent_old_seq_open,
 545         .read           = seq_read,
 546         .write          = recent_old_proc_write,
 547         .release        = seq_release_private,
 548         .owner          = THIS_MODULE,
 549 };
 550 #endif
 551
 552 static ssize_t
 553 recent_mt_proc_write(struct file *file, const char __user *input,
 554                      size_t size, loff_t *loff)
 555 {
 556         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 557         struct recent_table *t = pde->data;
 558         struct recent_entry *e;
 559         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 560         const char *c = buf;
 561         union nf_inet_addr addr = {};
 562         u_int16_t family;
 563         bool add, succ;
 564
 565         if (size == 0)
 566                 return 0;
 567         if (size > sizeof(buf))
 568                 size = sizeof(buf);
 569         if (copy_from_user(buf, input, size) != 0)
 570                 return -EFAULT;
 571
 572         /* Strict protocol! */
 573         if (*loff != 0)
 574                 return -ESPIPE;
 575         switch (*c) {
 576         case '/': /* flush table */
 577                 spin_lock_bh(&recent_lock);
 578                 recent_table_flush(t);
 579                 spin_unlock_bh(&recent_lock);
 580                 return size;
 581         case '-': /* remove address */
 582                 add = false;
 583                 break;
 584         case '+': /* add address */
 585                 add = true;
 586                 break;
 587         default:
 588                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 589                 return -EINVAL;
 590         }
 591
 592         ++c;
 593         --size;
 594         if (strnchr(c, size, ':') != NULL) {
 595                 family = NFPROTO_IPV6;
 596                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 597         } else {
 598                 family = NFPROTO_IPV4;
 599                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 600         }
 601
 602         if (!succ) {
 603                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 604                        "to procfs\n");
 605                 return -EINVAL;
 606         }
 607
 608         spin_lock_bh(&recent_lock);
 609         e = recent_entry_lookup(t, &addr, family, 0);
 610         if (e == NULL) {
 611                 if (add)
 612                         recent_entry_init(t, &addr, family, 0);
 613         } else {
 614                 if (add)
 615                         recent_entry_update(t, e);
 616                 else
 617                         recent_entry_remove(t, e);
 618         }
 619         spin_unlock_bh(&recent_lock);
 620         /* Note we removed one above */
 621         *loff += size + 1;
 622         return size + 1;
 623 }
 624
 625 static const struct file_operations recent_mt_fops = {
 626         .open    = recent_seq_open,
 627         .read    = seq_read,
 628         .write   = recent_mt_proc_write,
 629         .release = seq_release_private,
 630         .owner   = THIS_MODULE,
 631 };
 632
 633 static int __net_init recent_proc_net_init(struct net *net)
 634 {
 635         struct recent_net *recent_net = recent_pernet(net);
 636
 637         recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
 638         if (!recent_net->xt_recent)
 639                 return -ENOMEM;
 640 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 641         recent_net->ipt_recent = proc_mkdir("ipt_recent", net->proc_net);
 642         if (!recent_net->ipt_recent) {
 643                 proc_net_remove(net, "xt_recent");
 644                 return -ENOMEM;
 645         }
 646 #endif
 647         return 0;
 648 }
 649
 650 static void __net_exit recent_proc_net_exit(struct net *net)
 651 {
 652 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 653         proc_net_remove(net, "ipt_recent");
 654 #endif
 655         proc_net_remove(net, "xt_recent");
 656 }
 657 #else
 658 static inline int recent_proc_net_init(struct net *net)
 659 {
 660         return 0;
 661 }
 662
 663 static inline void recent_proc_net_exit(struct net *net)
 664 {
 665 }
 666 #endif /* CONFIG_PROC_FS */
 667
 668 static int __net_init recent_net_init(struct net *net)
 669 {
 670         struct recent_net *recent_net = recent_pernet(net);
 671
 672         INIT_LIST_HEAD(&recent_net->tables);
 673         return recent_proc_net_init(net);
 674 }
 675
 676 static void __net_exit recent_net_exit(struct net *net)
 677 {
 678         struct recent_net *recent_net = recent_pernet(net);
 679
 680         BUG_ON(!list_empty(&recent_net->tables));
 681         recent_proc_net_exit(net);
 682 }
 683
 684 static struct pernet_operations recent_net_ops = {
 685         .init   = recent_net_init,
 686         .exit   = recent_net_exit,
 687         .id     = &recent_net_id,
 688         .size   = sizeof(struct recent_net),
 689 };
 690
 691 static struct xt_match recent_mt_reg[] __read_mostly = {
 692         {
 693                 .name       = "recent",
 694                 .revision   = 0,
 695                 .family     = NFPROTO_IPV4,
 696                 .match      = recent_mt,
 697                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 698                 .checkentry = recent_mt_check,
 699                 .destroy    = recent_mt_destroy,
 700                 .me         = THIS_MODULE,
 701         },
 702         {
 703                 .name       = "recent",
 704                 .revision   = 0,
 705                 .family     = NFPROTO_IPV6,
 706                 .match      = recent_mt,
 707                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 708                 .checkentry = recent_mt_check,
 709                 .destroy    = recent_mt_destroy,
 710                 .me         = THIS_MODULE,
 711         },
 712 };
 713
 714 static int __init recent_mt_init(void)
 715 {
 716         int err;
 717
 718         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 719                 return -EINVAL;
 720         ip_list_hash_size = 1 << fls(ip_list_tot);
 721
 722         err = register_pernet_subsys(&recent_net_ops);
 723         if (err)
 724                 return err;
 725         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 726         if (err)
 727                 unregister_pernet_subsys(&recent_net_ops);
 728         return err;
 729 }
 730
 731 static void __exit recent_mt_exit(void)
 732 {
 733         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 734         unregister_pernet_subsys(&recent_net_ops);
 735 }
 736
 737 module_init(recent_mt_init);
 738 module_exit(recent_mt_exit);