net/netfilter/xt_recent.c

   1 /*
   2  * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
   3  * Copyright © CC Computer Consultants GmbH, 2007 - 2008
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This is a replacement of the old ipt_recent module, which carried the
  10  * following copyright notice:
  11  *
  12  * Author: Stephen Frost <sfrost@snowman.net>
  13  * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
  14  */
  15 #include <linux/init.h>
  16 #include <linux/ip.h>
  17 #include <linux/ipv6.h>
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/list.h>
  25 #include <linux/random.h>
  26 #include <linux/jhash.h>
  27 #include <linux/bitops.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/inet.h>
  30 #include <net/net_namespace.h>
  31 #include <net/netns/generic.h>
  32
  33 #include <linux/netfilter/x_tables.h>
  34 #include <linux/netfilter/xt_recent.h>
  35
  36 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  37 MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
  38 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4");
  39 MODULE_LICENSE("GPL");
  40 MODULE_ALIAS("ipt_recent");
  41 MODULE_ALIAS("ip6t_recent");
  42
  43 static unsigned int ip_list_tot = 100;
  44 static unsigned int ip_pkt_list_tot = 20;
  45 static unsigned int ip_list_hash_size = 0;
  46 static unsigned int ip_list_perms = 0644;
  47 static unsigned int ip_list_uid = 0;
  48 static unsigned int ip_list_gid = 0;
  49 module_param(ip_list_tot, uint, 0400);
  50 module_param(ip_pkt_list_tot, uint, 0400);
  51 module_param(ip_list_hash_size, uint, 0400);
  52 module_param(ip_list_perms, uint, 0400);
  53 module_param(ip_list_uid, uint, 0400);
  54 module_param(ip_list_gid, uint, 0400);
  55 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  56 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
  57 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
  58 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
  59 MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/xt_recent/* files");
  60 MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files");
  61
  62 struct recent_entry {
  63         struct list_head        list;
  64         struct list_head        lru_list;
  65         union nf_inet_addr      addr;
  66         u_int16_t               family;
  67         u_int8_t                ttl;
  68         u_int8_t                index;
  69         u_int16_t               nstamps;
  70         unsigned long           stamps[0];
  71 };
  72
  73 struct recent_table {
  74         struct list_head        list;
  75         char                    name[XT_RECENT_NAME_LEN];
  76         unsigned int            refcnt;
  77         unsigned int            entries;
  78         struct list_head        lru_list;
  79         struct list_head        iphash[0];
  80 };
  81
  82 struct recent_net {
  83         struct list_head        tables;
  84 #ifdef CONFIG_PROC_FS
  85         struct proc_dir_entry   *xt_recent;
  86 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  87         struct proc_dir_entry   *ipt_recent;
  88 #endif
  89 #endif
  90 };
  91
  92 static int recent_net_id;
  93 static inline struct recent_net *recent_pernet(struct net *net)
  94 {
  95         return net_generic(net, recent_net_id);
  96 }
  97
  98 static DEFINE_SPINLOCK(recent_lock);
  99 static DEFINE_MUTEX(recent_mutex);
 100
 101 #ifdef CONFIG_PROC_FS
 102 static const struct file_operations recent_old_fops, recent_mt_fops;
 103 #endif
 104
 105 static u_int32_t hash_rnd __read_mostly;
 106 static bool hash_rnd_inited __read_mostly;
 107
 108 static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
 109 {
 110         return jhash_1word((__force u32)addr->ip, hash_rnd) &
 111                (ip_list_hash_size - 1);
 112 }
 113
 114 static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
 115 {
 116         return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
 117                (ip_list_hash_size - 1);
 118 }
 119
 120 static struct recent_entry *
 121 recent_entry_lookup(const struct recent_table *table,
 122                     const union nf_inet_addr *addrp, u_int16_t family,
 123                     u_int8_t ttl)
 124 {
 125         struct recent_entry *e;
 126         unsigned int h;
 127
 128         if (family == NFPROTO_IPV4)
 129                 h = recent_entry_hash4(addrp);
 130         else
 131                 h = recent_entry_hash6(addrp);
 132
 133         list_for_each_entry(e, &table->iphash[h], list)
 134                 if (e->family == family &&
 135                     memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
 136                     (ttl == e->ttl || ttl == 0 || e->ttl == 0))
 137                         return e;
 138         return NULL;
 139 }
 140
 141 static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
 142 {
 143         list_del(&e->list);
 144         list_del(&e->lru_list);
 145         kfree(e);
 146         t->entries--;
 147 }
 148
 149 static struct recent_entry *
 150 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 151                   u_int16_t family, u_int8_t ttl)
 152 {
 153         struct recent_entry *e;
 154
 155         if (t->entries >= ip_list_tot) {
 156                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 157                 recent_entry_remove(t, e);
 158         }
 159         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 160                     GFP_ATOMIC);
 161         if (e == NULL)
 162                 return NULL;
 163         memcpy(&e->addr, addr, sizeof(e->addr));
 164         e->ttl       = ttl;
 165         e->stamps[0] = jiffies;
 166         e->nstamps   = 1;
 167         e->index     = 1;
 168         e->family    = family;
 169         if (family == NFPROTO_IPV4)
 170                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 171         else
 172                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 173         list_add_tail(&e->lru_list, &t->lru_list);
 174         t->entries++;
 175         return e;
 176 }
 177
 178 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 179 {
 180         e->stamps[e->index++] = jiffies;
 181         if (e->index > e->nstamps)
 182                 e->nstamps = e->index;
 183         e->index %= ip_pkt_list_tot;
 184         list_move_tail(&e->lru_list, &t->lru_list);
 185 }
 186
 187 static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
 188                                                 const char *name)
 189 {
 190         struct recent_table *t;
 191
 192         list_for_each_entry(t, &recent_net->tables, list)
 193                 if (!strcmp(t->name, name))
 194                         return t;
 195         return NULL;
 196 }
 197
 198 static void recent_table_flush(struct recent_table *t)
 199 {
 200         struct recent_entry *e, *next;
 201         unsigned int i;
 202
 203         for (i = 0; i < ip_list_hash_size; i++)
 204                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 205                         recent_entry_remove(t, e);
 206 }
 207
 208 static bool
 209 recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 210 {
 211         struct net *net = dev_net(par->in ? par->in : par->out);
 212         struct recent_net *recent_net = recent_pernet(net);
 213         const struct xt_recent_mtinfo *info = par->matchinfo;
 214         struct recent_table *t;
 215         struct recent_entry *e;
 216         union nf_inet_addr addr = {};
 217         u_int8_t ttl;
 218         bool ret = info->invert;
 219
 220         if (par->match->family == NFPROTO_IPV4) {
 221                 const struct iphdr *iph = ip_hdr(skb);
 222
 223                 if (info->side == XT_RECENT_DEST)
 224                         addr.ip = iph->daddr;
 225                 else
 226                         addr.ip = iph->saddr;
 227
 228                 ttl = iph->ttl;
 229         } else {
 230                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 231
 232                 if (info->side == XT_RECENT_DEST)
 233                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 234                 else
 235                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 236
 237                 ttl = iph->hop_limit;
 238         }
 239
 240         /* use TTL as seen before forwarding */
 241         if (par->out != NULL && skb->sk == NULL)
 242                 ttl++;
 243
 244         spin_lock_bh(&recent_lock);
 245         t = recent_table_lookup(recent_net, info->name);
 246         e = recent_entry_lookup(t, &addr, par->match->family,
 247                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 248         if (e == NULL) {
 249                 if (!(info->check_set & XT_RECENT_SET))
 250                         goto out;
 251                 e = recent_entry_init(t, &addr, par->match->family, ttl);
 252                 if (e == NULL)
 253                         *par->hotdrop = true;
 254                 ret = !ret;
 255                 goto out;
 256         }
 257
 258         if (info->check_set & XT_RECENT_SET)
 259                 ret = !ret;
 260         else if (info->check_set & XT_RECENT_REMOVE) {
 261                 recent_entry_remove(t, e);
 262                 ret = !ret;
 263         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 264                 unsigned long time = jiffies - info->seconds * HZ;
 265                 unsigned int i, hits = 0;
 266
 267                 for (i = 0; i < e->nstamps; i++) {
 268                         if (info->seconds && time_after(time, e->stamps[i]))
 269                                 continue;
 270                         if (++hits >= info->hit_count) {
 271                                 ret = !ret;
 272                                 break;
 273                         }
 274                 }
 275         }
 276
 277         if (info->check_set & XT_RECENT_SET ||
 278             (info->check_set & XT_RECENT_UPDATE && ret)) {
 279                 recent_entry_update(t, e);
 280                 e->ttl = ttl;
 281         }
 282 out:
 283         spin_unlock_bh(&recent_lock);
 284         return ret;
 285 }
 286
 287 static bool recent_mt_check(const struct xt_mtchk_param *par)
 288 {
 289         struct recent_net *recent_net = recent_pernet(par->net);
 290         const struct xt_recent_mtinfo *info = par->matchinfo;
 291         struct recent_table *t;
 292 #ifdef CONFIG_PROC_FS
 293         struct proc_dir_entry *pde;
 294 #endif
 295         unsigned i;
 296         bool ret = false;
 297
 298         if (unlikely(!hash_rnd_inited)) {
 299                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 300                 hash_rnd_inited = true;
 301         }
 302         if (hweight8(info->check_set &
 303                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 304                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 305                 return false;
 306         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 307             (info->seconds || info->hit_count))
 308                 return false;
 309         if (info->hit_count > ip_pkt_list_tot) {
 310                 pr_info(KBUILD_MODNAME ": hitcount (%u) is larger than "
 311                         "packets to be remembered (%u)\n",
 312                         info->hit_count, ip_pkt_list_tot);
 313                 return false;
 314         }
 315         if (info->name[0] == '\0' ||
 316             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 317                 return false;
 318
 319         mutex_lock(&recent_mutex);
 320         t = recent_table_lookup(recent_net, info->name);
 321         if (t != NULL) {
 322                 t->refcnt++;
 323                 ret = true;
 324                 goto out;
 325         }
 326
 327         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
 328                     GFP_KERNEL);
 329         if (t == NULL)
 330                 goto out;
 331         t->refcnt = 1;
 332         strcpy(t->name, info->name);
 333         INIT_LIST_HEAD(&t->lru_list);
 334         for (i = 0; i < ip_list_hash_size; i++)
 335                 INIT_LIST_HEAD(&t->iphash[i]);
 336 #ifdef CONFIG_PROC_FS
 337         pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
 338                   &recent_mt_fops, t);
 339         if (pde == NULL) {
 340                 kfree(t);
 341                 goto out;
 342         }
 343         pde->uid = ip_list_uid;
 344         pde->gid = ip_list_gid;
 345 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 346         pde = proc_create_data(t->name, ip_list_perms, recent_net->ipt_recent,
 347                       &recent_old_fops, t);
 348         if (pde == NULL) {
 349                 remove_proc_entry(t->name, recent_net->xt_recent);
 350                 kfree(t);
 351                 goto out;
 352         }
 353         pde->uid = ip_list_uid;
 354         pde->gid = ip_list_gid;
 355 #endif
 356 #endif
 357         spin_lock_bh(&recent_lock);
 358         list_add_tail(&t->list, &recent_net->tables);
 359         spin_unlock_bh(&recent_lock);
 360         ret = true;
 361 out:
 362         mutex_unlock(&recent_mutex);
 363         return ret;
 364 }
 365
 366 static void recent_mt_destroy(const struct xt_mtdtor_param *par)
 367 {
 368         struct recent_net *recent_net = recent_pernet(par->net);
 369         const struct xt_recent_mtinfo *info = par->matchinfo;
 370         struct recent_table *t;
 371
 372         mutex_lock(&recent_mutex);
 373         t = recent_table_lookup(recent_net, info->name);
 374         if (--t->refcnt == 0) {
 375                 spin_lock_bh(&recent_lock);
 376                 list_del(&t->list);
 377                 spin_unlock_bh(&recent_lock);
 378 #ifdef CONFIG_PROC_FS
 379 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 380                 remove_proc_entry(t->name, recent_net->ipt_recent);
 381 #endif
 382                 remove_proc_entry(t->name, recent_net->xt_recent);
 383 #endif
 384                 recent_table_flush(t);
 385                 kfree(t);
 386         }
 387         mutex_unlock(&recent_mutex);
 388 }
 389
 390 #ifdef CONFIG_PROC_FS
 391 struct recent_iter_state {
 392         const struct recent_table *table;
 393         unsigned int            bucket;
 394 };
 395
 396 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 397         __acquires(recent_lock)
 398 {
 399         struct recent_iter_state *st = seq->private;
 400         const struct recent_table *t = st->table;
 401         struct recent_entry *e;
 402         loff_t p = *pos;
 403
 404         spin_lock_bh(&recent_lock);
 405
 406         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
 407                 list_for_each_entry(e, &t->iphash[st->bucket], list)
 408                         if (p-- == 0)
 409                                 return e;
 410         return NULL;
 411 }
 412
 413 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 414 {
 415         struct recent_iter_state *st = seq->private;
 416         const struct recent_table *t = st->table;
 417         const struct recent_entry *e = v;
 418         const struct list_head *head = e->list.next;
 419
 420         while (head == &t->iphash[st->bucket]) {
 421                 if (++st->bucket >= ip_list_hash_size)
 422                         return NULL;
 423                 head = t->iphash[st->bucket].next;
 424         }
 425         (*pos)++;
 426         return list_entry(head, struct recent_entry, list);
 427 }
 428
 429 static void recent_seq_stop(struct seq_file *s, void *v)
 430         __releases(recent_lock)
 431 {
 432         spin_unlock_bh(&recent_lock);
 433 }
 434
 435 static int recent_seq_show(struct seq_file *seq, void *v)
 436 {
 437         const struct recent_entry *e = v;
 438         unsigned int i;
 439
 440         i = (e->index - 1) % ip_pkt_list_tot;
 441         if (e->family == NFPROTO_IPV4)
 442                 seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
 443                            &e->addr.ip, e->ttl, e->stamps[i], e->index);
 444         else
 445                 seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
 446                            &e->addr.in6, e->ttl, e->stamps[i], e->index);
 447         for (i = 0; i < e->nstamps; i++)
 448                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 449         seq_printf(seq, "\n");
 450         return 0;
 451 }
 452
 453 static const struct seq_operations recent_seq_ops = {
 454         .start          = recent_seq_start,
 455         .next           = recent_seq_next,
 456         .stop           = recent_seq_stop,
 457         .show           = recent_seq_show,
 458 };
 459
 460 static int recent_seq_open(struct inode *inode, struct file *file)
 461 {
 462         struct proc_dir_entry *pde = PDE(inode);
 463         struct recent_iter_state *st;
 464
 465         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 466         if (st == NULL)
 467                 return -ENOMEM;
 468
 469         st->table    = pde->data;
 470         return 0;
 471 }
 472
 473 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 474 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 475 {
 476         static bool warned_of_old;
 477
 478         if (unlikely(!warned_of_old)) {
 479                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 480                        " is deprecated; use /proc/net/xt_recent.\n");
 481                 warned_of_old = true;
 482         }
 483         return recent_seq_open(inode, filp);
 484 }
 485
 486 static ssize_t recent_old_proc_write(struct file *file,
 487                                      const char __user *input,
 488                                      size_t size, loff_t *loff)
 489 {
 490         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 491         struct recent_table *t = pde->data;
 492         struct recent_entry *e;
 493         char buf[sizeof("+255.255.255.255")], *c = buf;
 494         union nf_inet_addr addr = {};
 495         int add;
 496
 497         if (size > sizeof(buf))
 498                 size = sizeof(buf);
 499         if (copy_from_user(buf, input, size))
 500                 return -EFAULT;
 501
 502         c = skip_spaces(c);
 503
 504         if (size - (c - buf) < 5)
 505                 return c - buf;
 506         if (!strncmp(c, "clear", 5)) {
 507                 c += 5;
 508                 spin_lock_bh(&recent_lock);
 509                 recent_table_flush(t);
 510                 spin_unlock_bh(&recent_lock);
 511                 return c - buf;
 512         }
 513
 514         switch (*c) {
 515         case '-':
 516                 add = 0;
 517                 c++;
 518                 break;
 519         case '+':
 520                 c++;
 521         default:
 522                 add = 1;
 523                 break;
 524         }
 525         addr.ip = in_aton(c);
 526
 527         spin_lock_bh(&recent_lock);
 528         e = recent_entry_lookup(t, &addr, NFPROTO_IPV4, 0);
 529         if (e == NULL) {
 530                 if (add)
 531                         recent_entry_init(t, &addr, NFPROTO_IPV4, 0);
 532         } else {
 533                 if (add)
 534                         recent_entry_update(t, e);
 535                 else
 536                         recent_entry_remove(t, e);
 537         }
 538         spin_unlock_bh(&recent_lock);
 539         return size;
 540 }
 541
 542 static const struct file_operations recent_old_fops = {
 543         .open           = recent_old_seq_open,
 544         .read           = seq_read,
 545         .write          = recent_old_proc_write,
 546         .release        = seq_release_private,
 547         .owner          = THIS_MODULE,
 548 };
 549 #endif
 550
 551 static ssize_t
 552 recent_mt_proc_write(struct file *file, const char __user *input,
 553                      size_t size, loff_t *loff)
 554 {
 555         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 556         struct recent_table *t = pde->data;
 557         struct recent_entry *e;
 558         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 559         const char *c = buf;
 560         union nf_inet_addr addr = {};
 561         u_int16_t family;
 562         bool add, succ;
 563
 564         if (size == 0)
 565                 return 0;
 566         if (size > sizeof(buf))
 567                 size = sizeof(buf);
 568         if (copy_from_user(buf, input, size) != 0)
 569                 return -EFAULT;
 570
 571         /* Strict protocol! */
 572         if (*loff != 0)
 573                 return -ESPIPE;
 574         switch (*c) {
 575         case '/': /* flush table */
 576                 spin_lock_bh(&recent_lock);
 577                 recent_table_flush(t);
 578                 spin_unlock_bh(&recent_lock);
 579                 return size;
 580         case '-': /* remove address */
 581                 add = false;
 582                 break;
 583         case '+': /* add address */
 584                 add = true;
 585                 break;
 586         default:
 587                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 588                 return -EINVAL;
 589         }
 590
 591         ++c;
 592         --size;
 593         if (strnchr(c, size, ':') != NULL) {
 594                 family = NFPROTO_IPV6;
 595                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 596         } else {
 597                 family = NFPROTO_IPV4;
 598                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 599         }
 600
 601         if (!succ) {
 602                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 603                        "to procfs\n");
 604                 return -EINVAL;
 605         }
 606
 607         spin_lock_bh(&recent_lock);
 608         e = recent_entry_lookup(t, &addr, family, 0);
 609         if (e == NULL) {
 610                 if (add)
 611                         recent_entry_init(t, &addr, family, 0);
 612         } else {
 613                 if (add)
 614                         recent_entry_update(t, e);
 615                 else
 616                         recent_entry_remove(t, e);
 617         }
 618         spin_unlock_bh(&recent_lock);
 619         /* Note we removed one above */
 620         *loff += size + 1;
 621         return size + 1;
 622 }
 623
 624 static const struct file_operations recent_mt_fops = {
 625         .open    = recent_seq_open,
 626         .read    = seq_read,
 627         .write   = recent_mt_proc_write,
 628         .release = seq_release_private,
 629         .owner   = THIS_MODULE,
 630 };
 631
 632 static int __net_init recent_proc_net_init(struct net *net)
 633 {
 634         struct recent_net *recent_net = recent_pernet(net);
 635
 636         recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
 637         if (!recent_net->xt_recent)
 638                 return -ENOMEM;
 639 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 640         recent_net->ipt_recent = proc_mkdir("ipt_recent", net->proc_net);
 641         if (!recent_net->ipt_recent) {
 642                 proc_net_remove(net, "xt_recent");
 643                 return -ENOMEM;
 644         }
 645 #endif
 646         return 0;
 647 }
 648
 649 static void __net_exit recent_proc_net_exit(struct net *net)
 650 {
 651 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 652         proc_net_remove(net, "ipt_recent");
 653 #endif
 654         proc_net_remove(net, "xt_recent");
 655 }
 656 #else
 657 static inline int recent_proc_net_init(struct net *net)
 658 {
 659         return 0;
 660 }
 661
 662 static inline void recent_proc_net_exit(struct net *net)
 663 {
 664 }
 665 #endif /* CONFIG_PROC_FS */
 666
 667 static int __net_init recent_net_init(struct net *net)
 668 {
 669         struct recent_net *recent_net = recent_pernet(net);
 670
 671         INIT_LIST_HEAD(&recent_net->tables);
 672         return recent_proc_net_init(net);
 673 }
 674
 675 static void __net_exit recent_net_exit(struct net *net)
 676 {
 677         struct recent_net *recent_net = recent_pernet(net);
 678
 679         BUG_ON(!list_empty(&recent_net->tables));
 680         recent_proc_net_exit(net);
 681 }
 682
 683 static struct pernet_operations recent_net_ops = {
 684         .init   = recent_net_init,
 685         .exit   = recent_net_exit,
 686         .id     = &recent_net_id,
 687         .size   = sizeof(struct recent_net),
 688 };
 689
 690 static struct xt_match recent_mt_reg[] __read_mostly = {
 691         {
 692                 .name       = "recent",
 693                 .revision   = 0,
 694                 .family     = NFPROTO_IPV4,
 695                 .match      = recent_mt,
 696                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 697                 .checkentry = recent_mt_check,
 698                 .destroy    = recent_mt_destroy,
 699                 .me         = THIS_MODULE,
 700         },
 701         {
 702                 .name       = "recent",
 703                 .revision   = 0,
 704                 .family     = NFPROTO_IPV6,
 705                 .match      = recent_mt,
 706                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 707                 .checkentry = recent_mt_check,
 708                 .destroy    = recent_mt_destroy,
 709                 .me         = THIS_MODULE,
 710         },
 711 };
 712
 713 static int __init recent_mt_init(void)
 714 {
 715         int err;
 716
 717         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 718                 return -EINVAL;
 719         ip_list_hash_size = 1 << fls(ip_list_tot);
 720
 721         err = register_pernet_subsys(&recent_net_ops);
 722         if (err)
 723                 return err;
 724         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 725         if (err)
 726                 unregister_pernet_subsys(&recent_net_ops);
 727         return err;
 728 }
 729
 730 static void __exit recent_mt_exit(void)
 731 {
 732         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 733         unregister_pernet_subsys(&recent_net_ops);
 734 }
 735
 736 module_init(recent_mt_init);
 737 module_exit(recent_mt_exit);