net/netfilter/xt_TPROXY.c

   1 /*
   2  * Transparent proxy support for Linux/iptables
   3  *
   4  * Copyright (c) 2006-2010 BalaBit IT Ltd.
   5  * Author: Balazs Scheidler, Krisztian Kovacs
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13 #include <linux/module.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/ip.h>
  16 #include <net/checksum.h>
  17 #include <net/udp.h>
  18 #include <net/tcp.h>
  19 #include <net/inet_sock.h>
  20 #include <net/inet_hashtables.h>
  21 #include <linux/inetdevice.h>
  22 #include <linux/netfilter/x_tables.h>
  23 #include <linux/netfilter_ipv4/ip_tables.h>
  24
  25 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
  26
  27 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
  28 #define XT_TPROXY_HAVE_IPV6 1
  29 #include <net/if_inet6.h>
  30 #include <net/addrconf.h>
  31 #include <net/inet6_hashtables.h>
  32 #include <linux/netfilter_ipv6/ip6_tables.h>
  33 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  34 #endif
  35
  36 #include <linux/netfilter/xt_TPROXY.h>
  37
  38 enum nf_tproxy_lookup_t {
  39          NFT_LOOKUP_LISTENER,
  40          NFT_LOOKUP_ESTABLISHED,
  41 };
  42
  43 static bool tproxy_sk_is_transparent(struct sock *sk)
  44 {
  45         switch (sk->sk_state) {
  46         case TCP_TIME_WAIT:
  47                 if (inet_twsk(sk)->tw_transparent)
  48                         return true;
  49                 break;
  50         case TCP_NEW_SYN_RECV:
  51                 if (inet_rsk(inet_reqsk(sk))->no_srccheck)
  52                         return true;
  53                 break;
  54         default:
  55                 if (inet_sk(sk)->transparent)
  56                         return true;
  57         }
  58
  59         sock_gen_put(sk);
  60         return false;
  61 }
  62
  63 static inline __be32
  64 tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
  65 {
  66         struct in_device *indev;
  67         __be32 laddr;
  68
  69         if (user_laddr)
  70                 return user_laddr;
  71
  72         laddr = 0;
  73         rcu_read_lock();
  74         indev = __in_dev_get_rcu(skb->dev);
  75         for_primary_ifa(indev) {
  76                 laddr = ifa->ifa_local;
  77                 break;
  78         } endfor_ifa(indev);
  79         rcu_read_unlock();
  80
  81         return laddr ? laddr : daddr;
  82 }
  83
  84 /*
  85  * This is used when the user wants to intercept a connection matching
  86  * an explicit iptables rule. In this case the sockets are assumed
  87  * matching in preference order:
  88  *
  89  *   - match: if there's a fully established connection matching the
  90  *     _packet_ tuple, it is returned, assuming the redirection
  91  *     already took place and we process a packet belonging to an
  92  *     established connection
  93  *
  94  *   - match: if there's a listening socket matching the redirection
  95  *     (e.g. on-port & on-ip of the connection), it is returned,
  96  *     regardless if it was bound to 0.0.0.0 or an explicit
  97  *     address. The reasoning is that if there's an explicit rule, it
  98  *     does not really matter if the listener is bound to an interface
  99  *     or to 0. The user already stated that he wants redirection
 100  *     (since he added the rule).
 101  *
 102  * Please note that there's an overlap between what a TPROXY target
 103  * and a socket match will match. Normally if you have both rules the
 104  * "socket" match will be the first one, effectively all packets
 105  * belonging to established connections going through that one.
 106  */
 107 static inline struct sock *
 108 nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
 109                       const u8 protocol,
 110                       const __be32 saddr, const __be32 daddr,
 111                       const __be16 sport, const __be16 dport,
 112                       const struct net_device *in,
 113                       const enum nf_tproxy_lookup_t lookup_type)
 114 {
 115         struct sock *sk;
 116         struct tcphdr *tcph;
 117
 118         switch (protocol) {
 119         case IPPROTO_TCP:
 120                 switch (lookup_type) {
 121                 case NFT_LOOKUP_LISTENER:
 122                         tcph = hp;
 123                         sk = inet_lookup_listener(net, &tcp_hashinfo, skb,
 124                                                     ip_hdrlen(skb) +
 125                                                       __tcp_hdrlen(tcph),
 126                                                     saddr, sport,
 127                                                     daddr, dport,
 128                                                     in->ifindex);
 129
 130                         /* NOTE: we return listeners even if bound to
 131                          * 0.0.0.0, those are filtered out in
 132                          * xt_socket, since xt_TPROXY needs 0 bound
 133                          * listeners too
 134                          */
 135                         break;
 136                 case NFT_LOOKUP_ESTABLISHED:
 137                         sk = inet_lookup_established(net, &tcp_hashinfo,
 138                                                     saddr, sport, daddr, dport,
 139                                                     in->ifindex);
 140                         break;
 141                 default:
 142                         BUG();
 143                 }
 144                 break;
 145         case IPPROTO_UDP:
 146                 sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
 147                                      in->ifindex);
 148                 if (sk) {
 149                         int connected = (sk->sk_state == TCP_ESTABLISHED);
 150                         int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
 151
 152                         /* NOTE: we return listeners even if bound to
 153                          * 0.0.0.0, those are filtered out in
 154                          * xt_socket, since xt_TPROXY needs 0 bound
 155                          * listeners too
 156                          */
 157                         if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
 158                             (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
 159                                 sock_put(sk);
 160                                 sk = NULL;
 161                         }
 162                 }
 163                 break;
 164         default:
 165                 WARN_ON(1);
 166                 sk = NULL;
 167         }
 168
 169         pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
 170                  protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
 171
 172         return sk;
 173 }
 174
 175 #ifdef XT_TPROXY_HAVE_IPV6
 176 static inline struct sock *
 177 nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
 178                       const u8 protocol,
 179                       const struct in6_addr *saddr, const struct in6_addr *daddr,
 180                       const __be16 sport, const __be16 dport,
 181                       const struct net_device *in,
 182                       const enum nf_tproxy_lookup_t lookup_type)
 183 {
 184         struct sock *sk;
 185         struct tcphdr *tcph;
 186
 187         switch (protocol) {
 188         case IPPROTO_TCP:
 189                 switch (lookup_type) {
 190                 case NFT_LOOKUP_LISTENER:
 191                         tcph = hp;
 192                         sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
 193                                                    thoff + __tcp_hdrlen(tcph),
 194                                                    saddr, sport,
 195                                                    daddr, ntohs(dport),
 196                                                    in->ifindex);
 197
 198                         /* NOTE: we return listeners even if bound to
 199                          * 0.0.0.0, those are filtered out in
 200                          * xt_socket, since xt_TPROXY needs 0 bound
 201                          * listeners too
 202                          */
 203                         break;
 204                 case NFT_LOOKUP_ESTABLISHED:
 205                         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 206                                                         saddr, sport, daddr, ntohs(dport),
 207                                                         in->ifindex);
 208                         break;
 209                 default:
 210                         BUG();
 211                 }
 212                 break;
 213         case IPPROTO_UDP:
 214                 sk = udp6_lib_lookup(net, saddr, sport, daddr, dport,
 215                                      in->ifindex);
 216                 if (sk) {
 217                         int connected = (sk->sk_state == TCP_ESTABLISHED);
 218                         int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr);
 219
 220                         /* NOTE: we return listeners even if bound to
 221                          * 0.0.0.0, those are filtered out in
 222                          * xt_socket, since xt_TPROXY needs 0 bound
 223                          * listeners too
 224                          */
 225                         if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
 226                             (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
 227                                 sock_put(sk);
 228                                 sk = NULL;
 229                         }
 230                 }
 231                 break;
 232         default:
 233                 WARN_ON(1);
 234                 sk = NULL;
 235         }
 236
 237         pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n",
 238                  protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk);
 239
 240         return sk;
 241 }
 242 #endif
 243
 244 /**
 245  * tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
 246  * @skb:        The skb being processed.
 247  * @laddr:      IPv4 address to redirect to or zero.
 248  * @lport:      TCP port to redirect to or zero.
 249  * @sk:         The TIME_WAIT TCP socket found by the lookup.
 250  *
 251  * We have to handle SYN packets arriving to TIME_WAIT sockets
 252  * differently: instead of reopening the connection we should rather
 253  * redirect the new connection to the proxy if there's a listener
 254  * socket present.
 255  *
 256  * tproxy_handle_time_wait4() consumes the socket reference passed in.
 257  *
 258  * Returns the listener socket if there's one, the TIME_WAIT socket if
 259  * no such listener is found, or NULL if the TCP header is incomplete.
 260  */
 261 static struct sock *
 262 tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
 263                          __be32 laddr, __be16 lport, struct sock *sk)
 264 {
 265         const struct iphdr *iph = ip_hdr(skb);
 266         struct tcphdr _hdr, *hp;
 267
 268         hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
 269         if (hp == NULL) {
 270                 inet_twsk_put(inet_twsk(sk));
 271                 return NULL;
 272         }
 273
 274         if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
 275                 /* SYN to a TIME_WAIT socket, we'd rather redirect it
 276                  * to a listener socket if there's one */
 277                 struct sock *sk2;
 278
 279                 sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 280                                             iph->saddr, laddr ? laddr : iph->daddr,
 281                                             hp->source, lport ? lport : hp->dest,
 282                                             skb->dev, NFT_LOOKUP_LISTENER);
 283                 if (sk2) {
 284                         inet_twsk_deschedule_put(inet_twsk(sk));
 285                         sk = sk2;
 286                 }
 287         }
 288
 289         return sk;
 290 }
 291
 292 /* assign a socket to the skb -- consumes sk */
 293 static void
 294 nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
 295 {
 296         skb_orphan(skb);
 297         skb->sk = sk;
 298         skb->destructor = sock_edemux;
 299 }
 300
 301 static unsigned int
 302 tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
 303            u_int32_t mark_mask, u_int32_t mark_value)
 304 {
 305         const struct iphdr *iph = ip_hdr(skb);
 306         struct udphdr _hdr, *hp;
 307         struct sock *sk;
 308
 309         hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
 310         if (hp == NULL)
 311                 return NF_DROP;
 312
 313         /* check if there's an ongoing connection on the packet
 314          * addresses, this happens if the redirect already happened
 315          * and the current packet belongs to an already established
 316          * connection */
 317         sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 318                                    iph->saddr, iph->daddr,
 319                                    hp->source, hp->dest,
 320                                    skb->dev, NFT_LOOKUP_ESTABLISHED);
 321
 322         laddr = tproxy_laddr4(skb, laddr, iph->daddr);
 323         if (!lport)
 324                 lport = hp->dest;
 325
 326         /* UDP has no TCP_TIME_WAIT state, so we never enter here */
 327         if (sk && sk->sk_state == TCP_TIME_WAIT)
 328                 /* reopening a TIME_WAIT connection needs special handling */
 329                 sk = tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
 330         else if (!sk)
 331                 /* no, there's no established connection, check if
 332                  * there's a listener on the redirected addr/port */
 333                 sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 334                                            iph->saddr, laddr,
 335                                            hp->source, lport,
 336                                            skb->dev, NFT_LOOKUP_LISTENER);
 337
 338         /* NOTE: assign_sock consumes our sk reference */
 339         if (sk && tproxy_sk_is_transparent(sk)) {
 340                 /* This should be in a separate target, but we don't do multiple
 341                    targets on the same rule yet */
 342                 skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
 343
 344                 pr_debug("redirecting: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
 345                          iph->protocol, &iph->daddr, ntohs(hp->dest),
 346                          &laddr, ntohs(lport), skb->mark);
 347
 348                 nf_tproxy_assign_sock(skb, sk);
 349                 return NF_ACCEPT;
 350         }
 351
 352         pr_debug("no socket, dropping: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
 353                  iph->protocol, &iph->saddr, ntohs(hp->source),
 354                  &iph->daddr, ntohs(hp->dest), skb->mark);
 355         return NF_DROP;
 356 }
 357
 358 static unsigned int
 359 tproxy_tg4_v0(struct sk_buff *skb, const struct xt_action_param *par)
 360 {
 361         const struct xt_tproxy_target_info *tgi = par->targinfo;
 362
 363         return tproxy_tg4(par->net, skb, tgi->laddr, tgi->lport, tgi->mark_mask, tgi->mark_value);
 364 }
 365
 366 static unsigned int
 367 tproxy_tg4_v1(struct sk_buff *skb, const struct xt_action_param *par)
 368 {
 369         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 370
 371         return tproxy_tg4(par->net, skb, tgi->laddr.ip, tgi->lport, tgi->mark_mask, tgi->mark_value);
 372 }
 373
 374 #ifdef XT_TPROXY_HAVE_IPV6
 375
 376 static inline const struct in6_addr *
 377 tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
 378               const struct in6_addr *daddr)
 379 {
 380         struct inet6_dev *indev;
 381         struct inet6_ifaddr *ifa;
 382         struct in6_addr *laddr;
 383
 384         if (!ipv6_addr_any(user_laddr))
 385                 return user_laddr;
 386         laddr = NULL;
 387
 388         rcu_read_lock();
 389         indev = __in6_dev_get(skb->dev);
 390         if (indev)
 391                 list_for_each_entry(ifa, &indev->addr_list, if_list) {
 392                         if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
 393                                 continue;
 394
 395                         laddr = &ifa->addr;
 396                         break;
 397                 }
 398         rcu_read_unlock();
 399
 400         return laddr ? laddr : daddr;
 401 }
 402
 403 /**
 404  * tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
 405  * @skb:        The skb being processed.
 406  * @tproto:     Transport protocol.
 407  * @thoff:      Transport protocol header offset.
 408  * @par:        Iptables target parameters.
 409  * @sk:         The TIME_WAIT TCP socket found by the lookup.
 410  *
 411  * We have to handle SYN packets arriving to TIME_WAIT sockets
 412  * differently: instead of reopening the connection we should rather
 413  * redirect the new connection to the proxy if there's a listener
 414  * socket present.
 415  *
 416  * tproxy_handle_time_wait6() consumes the socket reference passed in.
 417  *
 418  * Returns the listener socket if there's one, the TIME_WAIT socket if
 419  * no such listener is found, or NULL if the TCP header is incomplete.
 420  */
 421 static struct sock *
 422 tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
 423                          const struct xt_action_param *par,
 424                          struct sock *sk)
 425 {
 426         const struct ipv6hdr *iph = ipv6_hdr(skb);
 427         struct tcphdr _hdr, *hp;
 428         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 429
 430         hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
 431         if (hp == NULL) {
 432                 inet_twsk_put(inet_twsk(sk));
 433                 return NULL;
 434         }
 435
 436         if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
 437                 /* SYN to a TIME_WAIT socket, we'd rather redirect it
 438                  * to a listener socket if there's one */
 439                 struct sock *sk2;
 440
 441                 sk2 = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 442                                             &iph->saddr,
 443                                             tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr),
 444                                             hp->source,
 445                                             tgi->lport ? tgi->lport : hp->dest,
 446                                             skb->dev, NFT_LOOKUP_LISTENER);
 447                 if (sk2) {
 448                         inet_twsk_deschedule_put(inet_twsk(sk));
 449                         sk = sk2;
 450                 }
 451         }
 452
 453         return sk;
 454 }
 455
 456 static unsigned int
 457 tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
 458 {
 459         const struct ipv6hdr *iph = ipv6_hdr(skb);
 460         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 461         struct udphdr _hdr, *hp;
 462         struct sock *sk;
 463         const struct in6_addr *laddr;
 464         __be16 lport;
 465         int thoff = 0;
 466         int tproto;
 467
 468         tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
 469         if (tproto < 0) {
 470                 pr_debug("unable to find transport header in IPv6 packet, dropping\n");
 471                 return NF_DROP;
 472         }
 473
 474         hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
 475         if (hp == NULL) {
 476                 pr_debug("unable to grab transport header contents in IPv6 packet, dropping\n");
 477                 return NF_DROP;
 478         }
 479
 480         /* check if there's an ongoing connection on the packet
 481          * addresses, this happens if the redirect already happened
 482          * and the current packet belongs to an already established
 483          * connection */
 484         sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 485                                    &iph->saddr, &iph->daddr,
 486                                    hp->source, hp->dest,
 487                                    par->in, NFT_LOOKUP_ESTABLISHED);
 488
 489         laddr = tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
 490         lport = tgi->lport ? tgi->lport : hp->dest;
 491
 492         /* UDP has no TCP_TIME_WAIT state, so we never enter here */
 493         if (sk && sk->sk_state == TCP_TIME_WAIT)
 494                 /* reopening a TIME_WAIT connection needs special handling */
 495                 sk = tproxy_handle_time_wait6(skb, tproto, thoff, par, sk);
 496         else if (!sk)
 497                 /* no there's no established connection, check if
 498                  * there's a listener on the redirected addr/port */
 499                 sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp,
 500                                            tproto, &iph->saddr, laddr,
 501                                            hp->source, lport,
 502                                            par->in, NFT_LOOKUP_LISTENER);
 503
 504         /* NOTE: assign_sock consumes our sk reference */
 505         if (sk && tproxy_sk_is_transparent(sk)) {
 506                 /* This should be in a separate target, but we don't do multiple
 507                    targets on the same rule yet */
 508                 skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
 509
 510                 pr_debug("redirecting: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
 511                          tproto, &iph->saddr, ntohs(hp->source),
 512                          laddr, ntohs(lport), skb->mark);
 513
 514                 nf_tproxy_assign_sock(skb, sk);
 515                 return NF_ACCEPT;
 516         }
 517
 518         pr_debug("no socket, dropping: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
 519                  tproto, &iph->saddr, ntohs(hp->source),
 520                  &iph->daddr, ntohs(hp->dest), skb->mark);
 521
 522         return NF_DROP;
 523 }
 524
 525 static int tproxy_tg6_check(const struct xt_tgchk_param *par)
 526 {
 527         const struct ip6t_ip6 *i = par->entryinfo;
 528
 529         if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP) &&
 530             !(i->invflags & IP6T_INV_PROTO))
 531                 return 0;
 532
 533         pr_info("Can be used only in combination with "
 534                 "either -p tcp or -p udp\n");
 535         return -EINVAL;
 536 }
 537 #endif
 538
 539 static int tproxy_tg4_check(const struct xt_tgchk_param *par)
 540 {
 541         const struct ipt_ip *i = par->entryinfo;
 542
 543         if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP)
 544             && !(i->invflags & IPT_INV_PROTO))
 545                 return 0;
 546
 547         pr_info("Can be used only in combination with "
 548                 "either -p tcp or -p udp\n");
 549         return -EINVAL;
 550 }
 551
 552 static struct xt_target tproxy_tg_reg[] __read_mostly = {
 553         {
 554                 .name           = "TPROXY",
 555                 .family         = NFPROTO_IPV4,
 556                 .table          = "mangle",
 557                 .target         = tproxy_tg4_v0,
 558                 .revision       = 0,
 559                 .targetsize     = sizeof(struct xt_tproxy_target_info),
 560                 .checkentry     = tproxy_tg4_check,
 561                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 562                 .me             = THIS_MODULE,
 563         },
 564         {
 565                 .name           = "TPROXY",
 566                 .family         = NFPROTO_IPV4,
 567                 .table          = "mangle",
 568                 .target         = tproxy_tg4_v1,
 569                 .revision       = 1,
 570                 .targetsize     = sizeof(struct xt_tproxy_target_info_v1),
 571                 .checkentry     = tproxy_tg4_check,
 572                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 573                 .me             = THIS_MODULE,
 574         },
 575 #ifdef XT_TPROXY_HAVE_IPV6
 576         {
 577                 .name           = "TPROXY",
 578                 .family         = NFPROTO_IPV6,
 579                 .table          = "mangle",
 580                 .target         = tproxy_tg6_v1,
 581                 .revision       = 1,
 582                 .targetsize     = sizeof(struct xt_tproxy_target_info_v1),
 583                 .checkentry     = tproxy_tg6_check,
 584                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 585                 .me             = THIS_MODULE,
 586         },
 587 #endif
 588
 589 };
 590
 591 static int __init tproxy_tg_init(void)
 592 {
 593         nf_defrag_ipv4_enable();
 594 #ifdef XT_TPROXY_HAVE_IPV6
 595         nf_defrag_ipv6_enable();
 596 #endif
 597
 598         return xt_register_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
 599 }
 600
 601 static void __exit tproxy_tg_exit(void)
 602 {
 603         xt_unregister_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
 604 }
 605
 606 module_init(tproxy_tg_init);
 607 module_exit(tproxy_tg_exit);
 608 MODULE_LICENSE("GPL");
 609 MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs");
 610 MODULE_DESCRIPTION("Netfilter transparent proxy (TPROXY) target module.");
 611 MODULE_ALIAS("ipt_TPROXY");
 612 MODULE_ALIAS("ip6t_TPROXY");