net/netfilter/xt_recent.c

   1 /*
   2  * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
   3  * Copyright © CC Computer Consultants GmbH, 2007 - 2008
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This is a replacement of the old ipt_recent module, which carried the
  10  * following copyright notice:
  11  *
  12  * Author: Stephen Frost <sfrost@snowman.net>
  13  * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
  14  */
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16 #include <linux/init.h>
  17 #include <linux/ip.h>
  18 #include <linux/ipv6.h>
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/string.h>
  24 #include <linux/ctype.h>
  25 #include <linux/list.h>
  26 #include <linux/random.h>
  27 #include <linux/jhash.h>
  28 #include <linux/bitops.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/inet.h>
  31 #include <linux/slab.h>
  32 #include <linux/vmalloc.h>
  33 #include <net/net_namespace.h>
  34 #include <net/netns/generic.h>
  35
  36 #include <linux/netfilter/x_tables.h>
  37 #include <linux/netfilter/xt_recent.h>
  38
  39 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  40 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
  41 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
  42 MODULE_LICENSE("GPL");
  43 MODULE_ALIAS("ipt_recent");
  44 MODULE_ALIAS("ip6t_recent");
  45
  46 static unsigned int ip_list_tot = 100;
  47 static unsigned int ip_pkt_list_tot = 20;
  48 static unsigned int ip_list_hash_size = 0;
  49 static unsigned int ip_list_perms = 0644;
  50 static unsigned int ip_list_uid = 0;
  51 static unsigned int ip_list_gid = 0;
  52 module_param(ip_list_tot, uint, 0400);
  53 module_param(ip_pkt_list_tot, uint, 0400);
  54 module_param(ip_list_hash_size, uint, 0400);
  55 module_param(ip_list_perms, uint, 0400);
  56 module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
  57 module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
  58 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  59 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
  60 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
  61 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
  62 MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
  63 MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
  64
  65 struct recent_entry {
  66         struct list_head        list;
  67         struct list_head        lru_list;
  68         union nf_inet_addr      addr;
  69         u_int16_t               family;
  70         u_int8_t                ttl;
  71         u_int8_t                index;
  72         u_int16_t               nstamps;
  73         unsigned long           stamps[0];
  74 };
  75
  76 struct recent_table {
  77         struct list_head        list;
  78         char                    name[XT_RECENT_NAME_LEN];
  79         union nf_inet_addr      mask;
  80         unsigned int            refcnt;
  81         unsigned int            entries;
  82         struct list_head        lru_list;
  83         struct list_head        iphash[0];
  84 };
  85
  86 struct recent_net {
  87         struct list_head        tables;
  88 #ifdef CONFIG_PROC_FS
  89         struct proc_dir_entry   *xt_recent;
  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 /*
 151  * Drop entries with timestamps older then 'time'.
 152  */
 153 static void recent_entry_reap(struct recent_table *t, unsigned long time)
 154 {
 155         struct recent_entry *e;
 156
 157         /*
 158          * The head of the LRU list is always the oldest entry.
 159          */
 160         e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 161
 162         /*
 163          * The last time stamp is the most recent.
 164          */
 165         if (time_after(time, e->stamps[e->index-1]))
 166                 recent_entry_remove(t, e);
 167 }
 168
 169 static struct recent_entry *
 170 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 171                   u_int16_t family, u_int8_t ttl)
 172 {
 173         struct recent_entry *e;
 174
 175         if (t->entries >= ip_list_tot) {
 176                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 177                 recent_entry_remove(t, e);
 178         }
 179         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 180                     GFP_ATOMIC);
 181         if (e == NULL)
 182                 return NULL;
 183         memcpy(&e->addr, addr, sizeof(e->addr));
 184         e->ttl       = ttl;
 185         e->stamps[0] = jiffies;
 186         e->nstamps   = 1;
 187         e->index     = 1;
 188         e->family    = family;
 189         if (family == NFPROTO_IPV4)
 190                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 191         else
 192                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 193         list_add_tail(&e->lru_list, &t->lru_list);
 194         t->entries++;
 195         return e;
 196 }
 197
 198 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 199 {
 200         e->index %= ip_pkt_list_tot;
 201         e->stamps[e->index++] = jiffies;
 202         if (e->index > e->nstamps)
 203                 e->nstamps = e->index;
 204         list_move_tail(&e->lru_list, &t->lru_list);
 205 }
 206
 207 static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
 208                                                 const char *name)
 209 {
 210         struct recent_table *t;
 211
 212         list_for_each_entry(t, &recent_net->tables, list)
 213                 if (!strcmp(t->name, name))
 214                         return t;
 215         return NULL;
 216 }
 217
 218 static void recent_table_flush(struct recent_table *t)
 219 {
 220         struct recent_entry *e, *next;
 221         unsigned int i;
 222
 223         for (i = 0; i < ip_list_hash_size; i++)
 224                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 225                         recent_entry_remove(t, e);
 226 }
 227
 228 static bool
 229 recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
 230 {
 231         struct net *net = dev_net(par->in ? par->in : par->out);
 232         struct recent_net *recent_net = recent_pernet(net);
 233         const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
 234         struct recent_table *t;
 235         struct recent_entry *e;
 236         union nf_inet_addr addr = {}, addr_mask;
 237         u_int8_t ttl;
 238         bool ret = info->invert;
 239
 240         if (par->family == NFPROTO_IPV4) {
 241                 const struct iphdr *iph = ip_hdr(skb);
 242
 243                 if (info->side == XT_RECENT_DEST)
 244                         addr.ip = iph->daddr;
 245                 else
 246                         addr.ip = iph->saddr;
 247
 248                 ttl = iph->ttl;
 249         } else {
 250                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 251
 252                 if (info->side == XT_RECENT_DEST)
 253                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 254                 else
 255                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 256
 257                 ttl = iph->hop_limit;
 258         }
 259
 260         /* use TTL as seen before forwarding */
 261         if (par->out != NULL && skb->sk == NULL)
 262                 ttl++;
 263
 264         spin_lock_bh(&recent_lock);
 265         t = recent_table_lookup(recent_net, info->name);
 266
 267         nf_inet_addr_mask(&addr, &addr_mask, &t->mask);
 268
 269         e = recent_entry_lookup(t, &addr_mask, par->family,
 270                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 271         if (e == NULL) {
 272                 if (!(info->check_set & XT_RECENT_SET))
 273                         goto out;
 274                 e = recent_entry_init(t, &addr_mask, par->family, ttl);
 275                 if (e == NULL)
 276                         par->hotdrop = true;
 277                 ret = !ret;
 278                 goto out;
 279         }
 280
 281         if (info->check_set & XT_RECENT_SET)
 282                 ret = !ret;
 283         else if (info->check_set & XT_RECENT_REMOVE) {
 284                 recent_entry_remove(t, e);
 285                 ret = !ret;
 286         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 287                 unsigned long time = jiffies - info->seconds * HZ;
 288                 unsigned int i, hits = 0;
 289
 290                 for (i = 0; i < e->nstamps; i++) {
 291                         if (info->seconds && time_after(time, e->stamps[i]))
 292                                 continue;
 293                         if (!info->hit_count || ++hits >= info->hit_count) {
 294                                 ret = !ret;
 295                                 break;
 296                         }
 297                 }
 298
 299                 /* info->seconds must be non-zero */
 300                 if (info->check_set & XT_RECENT_REAP)
 301                         recent_entry_reap(t, time);
 302         }
 303
 304         if (info->check_set & XT_RECENT_SET ||
 305             (info->check_set & XT_RECENT_UPDATE && ret)) {
 306                 recent_entry_update(t, e);
 307                 e->ttl = ttl;
 308         }
 309 out:
 310         spin_unlock_bh(&recent_lock);
 311         return ret;
 312 }
 313
 314 static void recent_table_free(void *addr)
 315 {
 316         if (is_vmalloc_addr(addr))
 317                 vfree(addr);
 318         else
 319                 kfree(addr);
 320 }
 321
 322 static int recent_mt_check(const struct xt_mtchk_param *par,
 323                            const struct xt_recent_mtinfo_v1 *info)
 324 {
 325         struct recent_net *recent_net = recent_pernet(par->net);
 326         struct recent_table *t;
 327 #ifdef CONFIG_PROC_FS
 328         struct proc_dir_entry *pde;
 329         kuid_t uid;
 330         kgid_t gid;
 331 #endif
 332         unsigned int i;
 333         int ret = -EINVAL;
 334         size_t sz;
 335
 336         if (unlikely(!hash_rnd_inited)) {
 337                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 338                 hash_rnd_inited = true;
 339         }
 340         if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
 341                 pr_info("Unsupported user space flags (%08x)\n",
 342                         info->check_set);
 343                 return -EINVAL;
 344         }
 345         if (hweight8(info->check_set &
 346                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 347                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 348                 return -EINVAL;
 349         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 350             (info->seconds || info->hit_count ||
 351             (info->check_set & XT_RECENT_MODIFIERS)))
 352                 return -EINVAL;
 353         if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
 354                 return -EINVAL;
 355         if (info->hit_count > ip_pkt_list_tot) {
 356                 pr_info("hitcount (%u) is larger than "
 357                         "packets to be remembered (%u)\n",
 358                         info->hit_count, ip_pkt_list_tot);
 359                 return -EINVAL;
 360         }
 361         if (info->name[0] == '\0' ||
 362             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 363                 return -EINVAL;
 364
 365         mutex_lock(&recent_mutex);
 366         t = recent_table_lookup(recent_net, info->name);
 367         if (t != NULL) {
 368                 t->refcnt++;
 369                 ret = 0;
 370                 goto out;
 371         }
 372
 373         sz = sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size;
 374         if (sz <= PAGE_SIZE)
 375                 t = kzalloc(sz, GFP_KERNEL);
 376         else
 377                 t = vzalloc(sz);
 378         if (t == NULL) {
 379                 ret = -ENOMEM;
 380                 goto out;
 381         }
 382         t->refcnt = 1;
 383
 384         memcpy(&t->mask, &info->mask, sizeof(t->mask));
 385         strcpy(t->name, info->name);
 386         INIT_LIST_HEAD(&t->lru_list);
 387         for (i = 0; i < ip_list_hash_size; i++)
 388                 INIT_LIST_HEAD(&t->iphash[i]);
 389 #ifdef CONFIG_PROC_FS
 390         uid = make_kuid(&init_user_ns, ip_list_uid);
 391         gid = make_kgid(&init_user_ns, ip_list_gid);
 392         if (!uid_valid(uid) || !gid_valid(gid)) {
 393                 recent_table_free(t);
 394                 ret = -EINVAL;
 395                 goto out;
 396         }
 397         pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
 398                   &recent_mt_fops, t);
 399         if (pde == NULL) {
 400                 recent_table_free(t);
 401                 ret = -ENOMEM;
 402                 goto out;
 403         }
 404         proc_set_user(pde, uid, gid);
 405 #endif
 406         spin_lock_bh(&recent_lock);
 407         list_add_tail(&t->list, &recent_net->tables);
 408         spin_unlock_bh(&recent_lock);
 409         ret = 0;
 410 out:
 411         mutex_unlock(&recent_mutex);
 412         return ret;
 413 }
 414
 415 static int recent_mt_check_v0(const struct xt_mtchk_param *par)
 416 {
 417         const struct xt_recent_mtinfo_v0 *info_v0 = par->matchinfo;
 418         struct xt_recent_mtinfo_v1 info_v1;
 419
 420         /* Copy revision 0 structure to revision 1 */
 421         memcpy(&info_v1, info_v0, sizeof(struct xt_recent_mtinfo));
 422         /* Set default mask to ensure backward compatible behaviour */
 423         memset(info_v1.mask.all, 0xFF, sizeof(info_v1.mask.all));
 424
 425         return recent_mt_check(par, &info_v1);
 426 }
 427
 428 static int recent_mt_check_v1(const struct xt_mtchk_param *par)
 429 {
 430         return recent_mt_check(par, par->matchinfo);
 431 }
 432
 433 static void recent_mt_destroy(const struct xt_mtdtor_param *par)
 434 {
 435         struct recent_net *recent_net = recent_pernet(par->net);
 436         const struct xt_recent_mtinfo_v1 *info = par->matchinfo;
 437         struct recent_table *t;
 438
 439         mutex_lock(&recent_mutex);
 440         t = recent_table_lookup(recent_net, info->name);
 441         if (--t->refcnt == 0) {
 442                 spin_lock_bh(&recent_lock);
 443                 list_del(&t->list);
 444                 spin_unlock_bh(&recent_lock);
 445 #ifdef CONFIG_PROC_FS
 446                 if (recent_net->xt_recent != NULL)
 447                         remove_proc_entry(t->name, recent_net->xt_recent);
 448 #endif
 449                 recent_table_flush(t);
 450                 recent_table_free(t);
 451         }
 452         mutex_unlock(&recent_mutex);
 453 }
 454
 455 #ifdef CONFIG_PROC_FS
 456 struct recent_iter_state {
 457         const struct recent_table *table;
 458         unsigned int            bucket;
 459 };
 460
 461 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 462         __acquires(recent_lock)
 463 {
 464         struct recent_iter_state *st = seq->private;
 465         const struct recent_table *t = st->table;
 466         struct recent_entry *e;
 467         loff_t p = *pos;
 468
 469         spin_lock_bh(&recent_lock);
 470
 471         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
 472                 list_for_each_entry(e, &t->iphash[st->bucket], list)
 473                         if (p-- == 0)
 474                                 return e;
 475         return NULL;
 476 }
 477
 478 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 479 {
 480         struct recent_iter_state *st = seq->private;
 481         const struct recent_table *t = st->table;
 482         const struct recent_entry *e = v;
 483         const struct list_head *head = e->list.next;
 484
 485         while (head == &t->iphash[st->bucket]) {
 486                 if (++st->bucket >= ip_list_hash_size)
 487                         return NULL;
 488                 head = t->iphash[st->bucket].next;
 489         }
 490         (*pos)++;
 491         return list_entry(head, struct recent_entry, list);
 492 }
 493
 494 static void recent_seq_stop(struct seq_file *s, void *v)
 495         __releases(recent_lock)
 496 {
 497         spin_unlock_bh(&recent_lock);
 498 }
 499
 500 static int recent_seq_show(struct seq_file *seq, void *v)
 501 {
 502         const struct recent_entry *e = v;
 503         unsigned int i;
 504
 505         i = (e->index - 1) % ip_pkt_list_tot;
 506         if (e->family == NFPROTO_IPV4)
 507                 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
 508                            &e->addr.ip, e->ttl, e->stamps[i], e->index);
 509         else
 510                 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
 511                            &e->addr.in6, e->ttl, e->stamps[i], e->index);
 512         for (i = 0; i < e->nstamps; i++)
 513                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 514         seq_printf(seq, "\n");
 515         return 0;
 516 }
 517
 518 static const struct seq_operations recent_seq_ops = {
 519         .start          = recent_seq_start,
 520         .next           = recent_seq_next,
 521         .stop           = recent_seq_stop,
 522         .show           = recent_seq_show,
 523 };
 524
 525 static int recent_seq_open(struct inode *inode, struct file *file)
 526 {
 527         struct recent_iter_state *st;
 528
 529         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 530         if (st == NULL)
 531                 return -ENOMEM;
 532
 533         st->table    = PDE_DATA(inode);
 534         return 0;
 535 }
 536
 537 static ssize_t
 538 recent_mt_proc_write(struct file *file, const char __user *input,
 539                      size_t size, loff_t *loff)
 540 {
 541         struct recent_table *t = PDE_DATA(file_inode(file));
 542         struct recent_entry *e;
 543         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 544         const char *c = buf;
 545         union nf_inet_addr addr = {};
 546         u_int16_t family;
 547         bool add, succ;
 548
 549         if (size == 0)
 550                 return 0;
 551         if (size > sizeof(buf))
 552                 size = sizeof(buf);
 553         if (copy_from_user(buf, input, size) != 0)
 554                 return -EFAULT;
 555
 556         /* Strict protocol! */
 557         if (*loff != 0)
 558                 return -ESPIPE;
 559         switch (*c) {
 560         case '/': /* flush table */
 561                 spin_lock_bh(&recent_lock);
 562                 recent_table_flush(t);
 563                 spin_unlock_bh(&recent_lock);
 564                 return size;
 565         case '-': /* remove address */
 566                 add = false;
 567                 break;
 568         case '+': /* add address */
 569                 add = true;
 570                 break;
 571         default:
 572                 pr_info("Need \"+ip\", \"-ip\" or \"/\"\n");
 573                 return -EINVAL;
 574         }
 575
 576         ++c;
 577         --size;
 578         if (strnchr(c, size, ':') != NULL) {
 579                 family = NFPROTO_IPV6;
 580                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 581         } else {
 582                 family = NFPROTO_IPV4;
 583                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 584         }
 585
 586         if (!succ) {
 587                 pr_info("illegal address written 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         .llseek = seq_lseek,
 615 };
 616
 617 static int __net_init recent_proc_net_init(struct net *net)
 618 {
 619         struct recent_net *recent_net = recent_pernet(net);
 620
 621         recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
 622         if (!recent_net->xt_recent)
 623                 return -ENOMEM;
 624         return 0;
 625 }
 626
 627 static void __net_exit recent_proc_net_exit(struct net *net)
 628 {
 629         struct recent_net *recent_net = recent_pernet(net);
 630         struct recent_table *t;
 631
 632         /* recent_net_exit() is called before recent_mt_destroy(). Make sure
 633          * that the parent xt_recent proc entry is is empty before trying to
 634          * remove it.
 635          */
 636         spin_lock_bh(&recent_lock);
 637         list_for_each_entry(t, &recent_net->tables, list)
 638                 remove_proc_entry(t->name, recent_net->xt_recent);
 639
 640         recent_net->xt_recent = NULL;
 641         spin_unlock_bh(&recent_lock);
 642
 643         remove_proc_entry("xt_recent", net->proc_net);
 644 }
 645 #else
 646 static inline int recent_proc_net_init(struct net *net)
 647 {
 648         return 0;
 649 }
 650
 651 static inline void recent_proc_net_exit(struct net *net)
 652 {
 653 }
 654 #endif /* CONFIG_PROC_FS */
 655
 656 static int __net_init recent_net_init(struct net *net)
 657 {
 658         struct recent_net *recent_net = recent_pernet(net);
 659
 660         INIT_LIST_HEAD(&recent_net->tables);
 661         return recent_proc_net_init(net);
 662 }
 663
 664 static void __net_exit recent_net_exit(struct net *net)
 665 {
 666         recent_proc_net_exit(net);
 667 }
 668
 669 static struct pernet_operations recent_net_ops = {
 670         .init   = recent_net_init,
 671         .exit   = recent_net_exit,
 672         .id     = &recent_net_id,
 673         .size   = sizeof(struct recent_net),
 674 };
 675
 676 static struct xt_match recent_mt_reg[] __read_mostly = {
 677         {
 678                 .name       = "recent",
 679                 .revision   = 0,
 680                 .family     = NFPROTO_IPV4,
 681                 .match      = recent_mt,
 682                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 683                 .checkentry = recent_mt_check_v0,
 684                 .destroy    = recent_mt_destroy,
 685                 .me         = THIS_MODULE,
 686         },
 687         {
 688                 .name       = "recent",
 689                 .revision   = 0,
 690                 .family     = NFPROTO_IPV6,
 691                 .match      = recent_mt,
 692                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 693                 .checkentry = recent_mt_check_v0,
 694                 .destroy    = recent_mt_destroy,
 695                 .me         = THIS_MODULE,
 696         },
 697         {
 698                 .name       = "recent",
 699                 .revision   = 1,
 700                 .family     = NFPROTO_IPV4,
 701                 .match      = recent_mt,
 702                 .matchsize  = sizeof(struct xt_recent_mtinfo_v1),
 703                 .checkentry = recent_mt_check_v1,
 704                 .destroy    = recent_mt_destroy,
 705                 .me         = THIS_MODULE,
 706         },
 707         {
 708                 .name       = "recent",
 709                 .revision   = 1,
 710                 .family     = NFPROTO_IPV6,
 711                 .match      = recent_mt,
 712                 .matchsize  = sizeof(struct xt_recent_mtinfo_v1),
 713                 .checkentry = recent_mt_check_v1,
 714                 .destroy    = recent_mt_destroy,
 715                 .me         = THIS_MODULE,
 716         }
 717 };
 718
 719 static int __init recent_mt_init(void)
 720 {
 721         int err;
 722
 723         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 724                 return -EINVAL;
 725         ip_list_hash_size = 1 << fls(ip_list_tot);
 726
 727         err = register_pernet_subsys(&recent_net_ops);
 728         if (err)
 729                 return err;
 730         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 731         if (err)
 732                 unregister_pernet_subsys(&recent_net_ops);
 733         return err;
 734 }
 735
 736 static void __exit recent_mt_exit(void)
 737 {
 738         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 739         unregister_pernet_subsys(&recent_net_ops);
 740 }
 741
 742 module_init(recent_mt_init);
 743 module_exit(recent_mt_exit);