release/src-rt-6.x/linux/linux-2.6/net/netfilter/xt_recent.c

   1 /*
   2  * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
   3  * Copyright Â© 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
  31 #include <linux/netfilter/x_tables.h>
  32 #include <linux/netfilter/xt_recent.h>
  33
  34 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  35 MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
  36 MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
  37 MODULE_LICENSE("GPL");
  38 MODULE_ALIAS("ipt_recent");
  39 MODULE_ALIAS("ip6t_recent");
  40
  41 static unsigned int ip_list_tot = 100;
  42 static unsigned int ip_pkt_list_tot = 20;
  43 static unsigned int ip_list_hash_size = 0;
  44 static unsigned int ip_list_perms = 0644;
  45 static unsigned int ip_list_uid = 0;
  46 static unsigned int ip_list_gid = 0;
  47 module_param(ip_list_tot, uint, 0400);
  48 module_param(ip_pkt_list_tot, uint, 0400);
  49 module_param(ip_list_hash_size, uint, 0400);
  50 module_param(ip_list_perms, uint, 0400);
  51 module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
  52 module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
  53 MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
  54 MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
  55 MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
  56 MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
  57 MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
  58 MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
  59
  60 struct recent_entry {
  61         struct list_head        list;
  62         struct list_head        lru_list;
  63         union nf_inet_addr      addr;
  64         u_int16_t               family;
  65         u_int8_t                ttl;
  66         u_int8_t                index;
  67         u_int16_t               nstamps;
  68         unsigned long           stamps[0];
  69 };
  70
  71 struct recent_table {
  72         struct list_head        list;
  73         char                    name[XT_RECENT_NAME_LEN];
  74         unsigned int            refcnt;
  75         unsigned int            entries;
  76         struct list_head        lru_list;
  77         struct list_head        iphash[0];
  78 };
  79
  80 static LIST_HEAD(tables);
  81 static DEFINE_SPINLOCK(recent_lock);
  82 static DEFINE_MUTEX(recent_mutex);
  83
  84 #ifdef CONFIG_PROC_FS
  85 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
  86 static struct proc_dir_entry *proc_old_dir;
  87 static const struct file_operations recent_old_fops;
  88 #endif
  89 static struct proc_dir_entry *recent_proc_dir;
  90 static const struct file_operations recent_mt_fops;
  91 #endif
  92
  93 static u_int32_t hash_rnd __read_mostly;
  94 static bool hash_rnd_inited __read_mostly;
  95
  96 static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
  97 {
  98         return jhash_1word((__force u32)addr->ip, hash_rnd) &
  99                (ip_list_hash_size - 1);
 100 }
 101
 102 static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
 103 {
 104         return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
 105                (ip_list_hash_size - 1);
 106 }
 107
 108 static struct recent_entry *
 109 recent_entry_lookup(const struct recent_table *table,
 110                     const union nf_inet_addr *addrp, u_int16_t family,
 111                     u_int8_t ttl)
 112 {
 113         struct recent_entry *e;
 114         unsigned int h;
 115
 116         if (family == AF_INET)
 117                 h = recent_entry_hash4(addrp);
 118         else
 119                 h = recent_entry_hash6(addrp);
 120
 121         list_for_each_entry(e, &table->iphash[h], list)
 122                 if (e->family == family &&
 123                     memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
 124                     (ttl == e->ttl || ttl == 0 || e->ttl == 0))
 125                         return e;
 126         return NULL;
 127 }
 128
 129 static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
 130 {
 131         list_del(&e->list);
 132         list_del(&e->lru_list);
 133         kfree(e);
 134         t->entries--;
 135 }
 136
 137 /*
 138  * Drop entries with timestamps older then 'time'.
 139  */
 140 static void recent_entry_reap(struct recent_table *t, unsigned long time)
 141 {
 142         struct recent_entry *e;
 143
 144         /*
 145          * The head of the LRU list is always the oldest entry.
 146          */
 147         e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 148
 149         /*
 150          * The last time stamp is the most recent.
 151          */
 152         if (time_after(time, e->stamps[e->index-1]))
 153                 recent_entry_remove(t, e);
 154 }
 155
 156 static struct recent_entry *
 157 recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
 158                   u_int16_t family, u_int8_t ttl)
 159 {
 160         struct recent_entry *e;
 161
 162         if (t->entries >= ip_list_tot) {
 163                 e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
 164                 recent_entry_remove(t, e);
 165         }
 166         e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
 167                     GFP_ATOMIC);
 168         if (e == NULL)
 169                 return NULL;
 170         memcpy(&e->addr, addr, sizeof(e->addr));
 171         e->ttl       = ttl;
 172         e->stamps[0] = jiffies;
 173         e->nstamps   = 1;
 174         e->index     = 1;
 175         e->family    = family;
 176         if (family == AF_INET)
 177                 list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
 178         else
 179                 list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
 180         list_add_tail(&e->lru_list, &t->lru_list);
 181         t->entries++;
 182         return e;
 183 }
 184
 185 static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
 186 {
 187         e->index %= ip_pkt_list_tot;
 188         e->stamps[e->index++] = jiffies;
 189         if (e->index > e->nstamps)
 190                 e->nstamps = e->index;
 191         list_move_tail(&e->lru_list, &t->lru_list);
 192 }
 193
 194 static struct recent_table *recent_table_lookup(const char *name)
 195 {
 196         struct recent_table *t;
 197
 198         list_for_each_entry(t, &tables, list)
 199                 if (!strcmp(t->name, name))
 200                         return t;
 201         return NULL;
 202 }
 203
 204 static void recent_table_flush(struct recent_table *t)
 205 {
 206         struct recent_entry *e, *next;
 207         unsigned int i;
 208
 209         for (i = 0; i < ip_list_hash_size; i++) {
 210                 list_for_each_entry_safe(e, next, &t->iphash[i], list)
 211                         recent_entry_remove(t, e);
 212         }
 213 }
 214
 215 static int
 216 recent_mt(const struct sk_buff *skb,
 217           const struct net_device *in, const struct net_device *out,
 218           const struct xt_match *match, const void *matchinfo,
 219           int offset, unsigned int protoff, int *hotdrop)
 220 {
 221         const struct xt_recent_mtinfo *info = matchinfo;
 222         struct recent_table *t;
 223         struct recent_entry *e;
 224         union nf_inet_addr addr = {};
 225         u_int8_t ttl;
 226         int ret = info->invert;
 227
 228         if (match->family == AF_INET) {
 229                 const struct iphdr *iph = ip_hdr(skb);
 230
 231                 if (info->side == XT_RECENT_DEST)
 232                         addr.ip = iph->daddr;
 233                 else
 234                         addr.ip = iph->saddr;
 235
 236                 ttl = iph->ttl;
 237         } else {
 238                 const struct ipv6hdr *iph = ipv6_hdr(skb);
 239
 240                 if (info->side == XT_RECENT_DEST)
 241                         memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
 242                 else
 243                         memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
 244
 245                 ttl = iph->hop_limit;
 246         }
 247
 248         /* use TTL as seen before forwarding */
 249         if (out && !skb->sk)
 250                 ttl++;
 251
 252         spin_lock_bh(&recent_lock);
 253         t = recent_table_lookup(info->name);
 254         e = recent_entry_lookup(t, &addr, match->family,
 255                                 (info->check_set & XT_RECENT_TTL) ? ttl : 0);
 256         if (e == NULL) {
 257                 if (!(info->check_set & XT_RECENT_SET))
 258                         goto out;
 259                 e = recent_entry_init(t, &addr, match->family, ttl);
 260                 if (e == NULL)
 261                         *hotdrop = 1;
 262                 ret ^= 1;
 263                 goto out;
 264         }
 265
 266         if (info->check_set & XT_RECENT_SET)
 267                 ret ^= 1;
 268         else if (info->check_set & XT_RECENT_REMOVE) {
 269                 recent_entry_remove(t, e);
 270                 ret ^= 1;
 271         } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
 272                 unsigned long time = jiffies - info->seconds * HZ;
 273                 unsigned int i, hits = 0;
 274
 275                 for (i = 0; i < e->nstamps; i++) {
 276                         if (info->seconds && time_after(time, e->stamps[i]))
 277                                 continue;
 278                         if (!info->hit_count || ++hits >= info->hit_count) {
 279                                 ret ^= 1;
 280                                 break;
 281                         }
 282                 }
 283
 284                 /* info->seconds must be non-zero */
 285                 if (info->check_set & XT_RECENT_REAP)
 286                         recent_entry_reap(t, time);
 287         }
 288
 289         if (info->check_set & XT_RECENT_SET ||
 290             (info->check_set & XT_RECENT_UPDATE && ret)) {
 291                 recent_entry_update(t, e);
 292                 e->ttl = ttl;
 293         }
 294 out:
 295         spin_unlock_bh(&recent_lock);
 296         return ret;
 297 }
 298
 299 static int
 300 recent_mt_check(const char *tablename, const void *ip,
 301                 const struct xt_match *match, void *matchinfo,
 302                 unsigned int hook_mask)
 303 {
 304         const struct xt_recent_mtinfo *info = matchinfo;
 305         struct recent_table *t;
 306 #ifdef CONFIG_PROC_FS
 307         struct proc_dir_entry *pde;
 308 #endif
 309         unsigned i;
 310         int ret = 0;
 311
 312         if (unlikely(!hash_rnd_inited)) {
 313                 get_random_bytes(&hash_rnd, sizeof(hash_rnd));
 314                 hash_rnd_inited = true;
 315         }
 316         if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
 317                 pr_info(KBUILD_MODNAME ": Unsupported user space flags "
 318                         "(%08x)\n", info->check_set);
 319                 return 0;
 320         }
 321         if (hweight8(info->check_set &
 322                      (XT_RECENT_SET | XT_RECENT_REMOVE |
 323                       XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
 324                 return 0;
 325         if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
 326             (info->seconds || info->hit_count ||
 327             (info->check_set & XT_RECENT_MODIFIERS)))
 328                 return 0;
 329         if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
 330                 return 0;
 331         if (info->hit_count > ip_pkt_list_tot) {
 332                 pr_info(KBUILD_MODNAME ": hitcount (%u) is larger than "
 333                         "packets to be remembered (%u)\n",
 334                         info->hit_count, ip_pkt_list_tot);
 335                 return 0;
 336         }
 337         if (info->name[0] == '\0' ||
 338             strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
 339                 return 0;
 340
 341         mutex_lock(&recent_mutex);
 342         t = recent_table_lookup(info->name);
 343         if (t != NULL) {
 344                 t->refcnt++;
 345                 ret = 1;
 346                 goto out;
 347         }
 348
 349         t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
 350                     GFP_KERNEL);
 351         if (t == NULL)
 352                 goto out;
 353         t->refcnt = 1;
 354         strcpy(t->name, info->name);
 355         INIT_LIST_HEAD(&t->lru_list);
 356         for (i = 0; i < ip_list_hash_size; i++)
 357                 INIT_LIST_HEAD(&t->iphash[i]);
 358 #ifdef CONFIG_PROC_FS
 359         pde = create_proc_entry(t->name, ip_list_perms, recent_proc_dir);
 360         if (pde == NULL) {
 361                 kfree(t);
 362                 goto out;
 363         }
 364         pde->proc_fops = &recent_mt_fops;
 365         pde->uid = ip_list_uid;
 366         pde->gid = ip_list_gid;
 367         pde->data = t;
 368 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 369         pde = create_proc_entry(t->name, ip_list_perms, proc_old_dir);
 370         if (pde == NULL) {
 371                 remove_proc_entry(t->name, recent_proc_dir);
 372                 kfree(t);
 373                 goto out;
 374         }
 375         pde->proc_fops = &recent_old_fops;
 376         pde->uid = ip_list_uid;
 377         pde->gid = ip_list_gid;
 378         pde->data = t;
 379 #endif
 380 #endif
 381         spin_lock_bh(&recent_lock);
 382         list_add_tail(&t->list, &tables);
 383         spin_unlock_bh(&recent_lock);
 384         ret = 1;
 385 out:
 386         mutex_unlock(&recent_mutex);
 387         return ret;
 388 }
 389
 390 static void
 391 recent_mt_destroy(const struct xt_match *match, void *matchinfo)
 392 {
 393         const struct xt_recent_mtinfo *info = matchinfo;
 394         struct recent_table *t;
 395
 396         mutex_lock(&recent_mutex);
 397         t = recent_table_lookup(info->name);
 398         if (--t->refcnt == 0) {
 399                 spin_lock_bh(&recent_lock);
 400                 list_del(&t->list);
 401                 spin_unlock_bh(&recent_lock);
 402 #ifdef CONFIG_PROC_FS
 403 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 404                 remove_proc_entry(t->name, proc_old_dir);
 405 #endif
 406                 remove_proc_entry(t->name, recent_proc_dir);
 407 #endif
 408                 recent_table_flush(t);
 409                 kfree(t);
 410         }
 411         mutex_unlock(&recent_mutex);
 412 }
 413
 414 #ifdef CONFIG_PROC_FS
 415 struct recent_iter_state {
 416         const struct recent_table *table;
 417         unsigned int            bucket;
 418 };
 419
 420 static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
 421         __acquires(recent_lock)
 422 {
 423         struct recent_iter_state *st = seq->private;
 424         const struct recent_table *t = st->table;
 425         struct recent_entry *e;
 426         loff_t p = *pos;
 427
 428         spin_lock_bh(&recent_lock);
 429
 430         for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++) {
 431                 list_for_each_entry(e, &t->iphash[st->bucket], list) {
 432                         if (p-- == 0)
 433                                 return e;
 434                 }
 435         }
 436         return NULL;
 437 }
 438
 439 static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 440 {
 441         struct recent_iter_state *st = seq->private;
 442         const struct recent_table *t = st->table;
 443         const struct recent_entry *e = v;
 444         const struct list_head *head = e->list.next;
 445
 446         while (head == &t->iphash[st->bucket]) {
 447                 if (++st->bucket >= ip_list_hash_size)
 448                         return NULL;
 449                 head = t->iphash[st->bucket].next;
 450         }
 451         (*pos)++;
 452         return list_entry(head, struct recent_entry, list);
 453 }
 454
 455 static void recent_seq_stop(struct seq_file *s, void *v)
 456         __releases(recent_lock)
 457 {
 458         spin_unlock_bh(&recent_lock);
 459 }
 460
 461 static int recent_seq_show(struct seq_file *seq, void *v)
 462 {
 463         struct recent_entry *e = v;
 464         unsigned int i;
 465
 466         i = (e->index - 1) % ip_pkt_list_tot;
 467         if (e->family == AF_INET)
 468                 seq_printf(seq, "src=" NIPQUAD_FMT " ttl: %u last_seen: %lu "
 469                            "oldest_pkt: %u", NIPQUAD(e->addr.ip), e->ttl,
 470                            e->stamps[i], e->index);
 471         else
 472                 seq_printf(seq, "src=" NIP6_FMT " ttl: %u last_seen: %lu "
 473                            "oldest_pkt: %u", NIP6(e->addr.in6), e->ttl,
 474                            e->stamps[i], e->index);
 475         for (i = 0; i < e->nstamps; i++)
 476                 seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
 477         seq_printf(seq, "\n");
 478         return 0;
 479 }
 480
 481 static struct seq_operations recent_seq_ops = {
 482         .start          = recent_seq_start,
 483         .next           = recent_seq_next,
 484         .stop           = recent_seq_stop,
 485         .show           = recent_seq_show,
 486 };
 487
 488 static int recent_seq_open(struct inode *inode, struct file *file)
 489 {
 490         struct proc_dir_entry *pde = PDE(inode);
 491         struct recent_iter_state *st;
 492
 493         st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
 494         if (st == NULL)
 495                 return -ENOMEM;
 496
 497         st->table    = pde->data;
 498         return 0;
 499 }
 500
 501 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 502 static int recent_old_seq_open(struct inode *inode, struct file *filp)
 503 {
 504         static bool warned_of_old;
 505
 506         if (unlikely(!warned_of_old)) {
 507                 printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"
 508                        " is deprecated; use /proc/net/xt_recent.\n");
 509                 warned_of_old = true;
 510         }
 511         return recent_seq_open(inode, filp);
 512 }
 513
 514 static ssize_t recent_old_proc_write(struct file *file,
 515                                      const char __user *input,
 516                                      size_t size, loff_t *loff)
 517 {
 518         struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 519         struct recent_table *t = pde->data;
 520         struct recent_entry *e;
 521         char buf[sizeof("+255.255.255.255")], *c = buf;
 522         union nf_inet_addr addr = {};
 523         int add;
 524
 525         if (size > sizeof(buf))
 526                 size = sizeof(buf);
 527         if (copy_from_user(buf, input, size))
 528                 return -EFAULT;
 529
 530         while (isspace(*c))
 531                 c++;
 532
 533         if (size - (c - buf) < 5)
 534                 return c - buf;
 535         if (!strncmp(c, "clear", 5)) {
 536                 c += 5;
 537                 spin_lock_bh(&recent_lock);
 538                 recent_table_flush(t);
 539                 spin_unlock_bh(&recent_lock);
 540                 return c - buf;
 541         }
 542
 543         switch (*c) {
 544         case '-':
 545                 add = 0;
 546                 c++;
 547                 break;
 548         case '+':
 549                 c++;
 550         default:
 551                 add = 1;
 552                 break;
 553         }
 554         addr.ip = in_aton(c);
 555
 556         spin_lock_bh(&recent_lock);
 557         e = recent_entry_lookup(t, &addr, PF_INET, 0);
 558         if (e == NULL) {
 559                 if (add)
 560                         recent_entry_init(t, &addr, PF_INET, 0);
 561         } else {
 562                 if (add)
 563                         recent_entry_update(t, e);
 564                 else
 565                         recent_entry_remove(t, e);
 566         }
 567         spin_unlock_bh(&recent_lock);
 568         return size;
 569 }
 570
 571 static const struct file_operations recent_old_fops = {
 572         .open           = recent_old_seq_open,
 573         .read           = seq_read,
 574         .write          = recent_old_proc_write,
 575         .release        = seq_release_private,
 576         .owner          = THIS_MODULE,
 577 };
 578 #endif
 579
 580 static ssize_t
 581 recent_mt_proc_write(struct file *file, const char __user *input,
 582                      size_t size, loff_t *loff)
 583 {
 584         const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 585         struct recent_table *t = pde->data;
 586         struct recent_entry *e;
 587         char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
 588         const char *c = buf;
 589         union nf_inet_addr addr = {};
 590         u_int16_t family;
 591         bool add, succ;
 592
 593         if (size == 0)
 594                 return 0;
 595         if (size > sizeof(buf))
 596                 size = sizeof(buf);
 597         if (copy_from_user(buf, input, size) != 0)
 598                 return -EFAULT;
 599
 600         /* Strict protocol! */
 601         if (*loff != 0)
 602                 return -ESPIPE;
 603         switch (*c) {
 604         case '/': /* flush table */
 605                 spin_lock_bh(&recent_lock);
 606                 recent_table_flush(t);
 607                 spin_unlock_bh(&recent_lock);
 608                 return size;
 609         case '-': /* remove address */
 610                 add = false;
 611                 break;
 612         case '+': /* add address */
 613                 add = true;
 614                 break;
 615         default:
 616                 printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");
 617                 return -EINVAL;
 618         }
 619
 620         ++c;
 621         --size;
 622         if (strnchr(c, size, ':') != NULL) {
 623                 family = AF_INET6;
 624                 succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);
 625         } else {
 626                 family = AF_INET;
 627                 succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);
 628         }
 629
 630         if (!succ) {
 631                 printk(KERN_INFO KBUILD_MODNAME ": illegal address written "
 632                        "to procfs\n");
 633                 return -EINVAL;
 634         }
 635
 636         spin_lock_bh(&recent_lock);
 637         e = recent_entry_lookup(t, &addr, family, 0);
 638         if (e == NULL) {
 639                 if (add)
 640                         recent_entry_init(t, &addr, family, 0);
 641         } else {
 642                 if (add)
 643                         recent_entry_update(t, e);
 644                 else
 645                         recent_entry_remove(t, e);
 646         }
 647         spin_unlock_bh(&recent_lock);
 648         /* Note we removed one above */
 649         *loff += size + 1;
 650         return size + 1;
 651 }
 652
 653 static const struct file_operations recent_mt_fops = {
 654         .open    = recent_seq_open,
 655         .read    = seq_read,
 656         .write   = recent_mt_proc_write,
 657         .release = seq_release_private,
 658         .owner   = THIS_MODULE,
 659 };
 660 #endif /* CONFIG_PROC_FS */
 661
 662 static struct xt_match recent_mt_reg[] __read_mostly = {
 663         {
 664                 .name       = "recent",
 665                 .family     = AF_INET,
 666                 .match      = recent_mt,
 667                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 668                 .checkentry = recent_mt_check,
 669                 .destroy    = recent_mt_destroy,
 670                 .me         = THIS_MODULE,
 671         },
 672         {
 673                 .name       = "recent",
 674                 .family     = AF_INET6,
 675                 .match      = recent_mt,
 676                 .matchsize  = sizeof(struct xt_recent_mtinfo),
 677                 .checkentry = recent_mt_check,
 678                 .destroy    = recent_mt_destroy,
 679                 .me         = THIS_MODULE,
 680         },
 681 };
 682
 683 static int __init recent_mt_init(void)
 684 {
 685         int err;
 686
 687         if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
 688                 return -EINVAL;
 689         ip_list_hash_size = 1 << fls(ip_list_tot);
 690
 691         err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 692 #ifdef CONFIG_PROC_FS
 693         if (err)
 694                 return err;
 695         recent_proc_dir = proc_mkdir("xt_recent", proc_net);
 696         if (recent_proc_dir == NULL) {
 697                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 698                 err = -ENOMEM;
 699         }
 700 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 701         if (err < 0)
 702                 return err;
 703         proc_old_dir = proc_mkdir("ipt_recent", proc_net);
 704         if (proc_old_dir == NULL) {
 705                 remove_proc_entry("xt_recent", proc_net);
 706                 xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 707                 err = -ENOMEM;
 708         }
 709 #endif
 710 #endif
 711         return err;
 712 }
 713
 714 static void __exit recent_mt_exit(void)
 715 {
 716         BUG_ON(!list_empty(&tables));
 717         xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
 718 #ifdef CONFIG_PROC_FS
 719 #ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT
 720         remove_proc_entry("ipt_recent", proc_net);
 721 #endif
 722         remove_proc_entry("xt_recent", proc_net);
 723 #endif
 724 }
 725
 726 module_init(recent_mt_init);
 727 module_exit(recent_mt_exit);