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                         if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
 131                                 sk = NULL;
 132                         /* NOTE: we return listeners even if bound to
 133                          * 0.0.0.0, those are filtered out in
 134                          * xt_socket, since xt_TPROXY needs 0 bound
 135                          * listeners too
 136                          */
 137                         break;
 138                 case NFT_LOOKUP_ESTABLISHED:
 139                         sk = inet_lookup_established(net, &tcp_hashinfo,
 140                                                     saddr, sport, daddr, dport,
 141                                                     in->ifindex);
 142                         break;
 143                 default:
 144                         BUG();
 145                 }
 146                 break;
 147         case IPPROTO_UDP:
 148                 sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
 149                                      in->ifindex);
 150                 if (sk) {
 151                         int connected = (sk->sk_state == TCP_ESTABLISHED);
 152                         int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
 153
 154                         /* NOTE: we return listeners even if bound to
 155                          * 0.0.0.0, those are filtered out in
 156                          * xt_socket, since xt_TPROXY needs 0 bound
 157                          * listeners too
 158                          */
 159                         if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
 160                             (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
 161                                 sock_put(sk);
 162                                 sk = NULL;
 163                         }
 164                 }
 165                 break;
 166         default:
 167                 WARN_ON(1);
 168                 sk = NULL;
 169         }
 170
 171         pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
 172                  protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
 173
 174         return sk;
 175 }
 176
 177 #ifdef XT_TPROXY_HAVE_IPV6
 178 static inline struct sock *
 179 nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
 180                       const u8 protocol,
 181                       const struct in6_addr *saddr, const struct in6_addr *daddr,
 182                       const __be16 sport, const __be16 dport,
 183                       const struct net_device *in,
 184                       const enum nf_tproxy_lookup_t lookup_type)
 185 {
 186         struct sock *sk;
 187         struct tcphdr *tcph;
 188
 189         switch (protocol) {
 190         case IPPROTO_TCP:
 191                 switch (lookup_type) {
 192                 case NFT_LOOKUP_LISTENER:
 193                         tcph = hp;
 194                         sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
 195                                                    thoff + __tcp_hdrlen(tcph),
 196                                                    saddr, sport,
 197                                                    daddr, ntohs(dport),
 198                                                    in->ifindex);
 199
 200                         if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
 201                                 sk = NULL;
 202                         /* NOTE: we return listeners even if bound to
 203                          * 0.0.0.0, those are filtered out in
 204                          * xt_socket, since xt_TPROXY needs 0 bound
 205                          * listeners too
 206                          */
 207                         break;
 208                 case NFT_LOOKUP_ESTABLISHED:
 209                         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 210                                                         saddr, sport, daddr, ntohs(dport),
 211                                                         in->ifindex);
 212                         break;
 213                 default:
 214                         BUG();
 215                 }
 216                 break;
 217         case IPPROTO_UDP:
 218                 sk = udp6_lib_lookup(net, saddr, sport, daddr, dport,
 219                                      in->ifindex);
 220                 if (sk) {
 221                         int connected = (sk->sk_state == TCP_ESTABLISHED);
 222                         int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr);
 223
 224                         /* NOTE: we return listeners even if bound to
 225                          * 0.0.0.0, those are filtered out in
 226                          * xt_socket, since xt_TPROXY needs 0 bound
 227                          * listeners too
 228                          */
 229                         if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
 230                             (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
 231                                 sock_put(sk);
 232                                 sk = NULL;
 233                         }
 234                 }
 235                 break;
 236         default:
 237                 WARN_ON(1);
 238                 sk = NULL;
 239         }
 240
 241         pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n",
 242                  protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk);
 243
 244         return sk;
 245 }
 246 #endif
 247
 248 /**
 249  * tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
 250  * @skb:        The skb being processed.
 251  * @laddr:      IPv4 address to redirect to or zero.
 252  * @lport:      TCP port to redirect to or zero.
 253  * @sk:         The TIME_WAIT TCP socket found by the lookup.
 254  *
 255  * We have to handle SYN packets arriving to TIME_WAIT sockets
 256  * differently: instead of reopening the connection we should rather
 257  * redirect the new connection to the proxy if there's a listener
 258  * socket present.
 259  *
 260  * tproxy_handle_time_wait4() consumes the socket reference passed in.
 261  *
 262  * Returns the listener socket if there's one, the TIME_WAIT socket if
 263  * no such listener is found, or NULL if the TCP header is incomplete.
 264  */
 265 static struct sock *
 266 tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
 267                          __be32 laddr, __be16 lport, struct sock *sk)
 268 {
 269         const struct iphdr *iph = ip_hdr(skb);
 270         struct tcphdr _hdr, *hp;
 271
 272         hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
 273         if (hp == NULL) {
 274                 inet_twsk_put(inet_twsk(sk));
 275                 return NULL;
 276         }
 277
 278         if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
 279                 /* SYN to a TIME_WAIT socket, we'd rather redirect it
 280                  * to a listener socket if there's one */
 281                 struct sock *sk2;
 282
 283                 sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 284                                             iph->saddr, laddr ? laddr : iph->daddr,
 285                                             hp->source, lport ? lport : hp->dest,
 286                                             skb->dev, NFT_LOOKUP_LISTENER);
 287                 if (sk2) {
 288                         inet_twsk_deschedule_put(inet_twsk(sk));
 289                         sk = sk2;
 290                 }
 291         }
 292
 293         return sk;
 294 }
 295
 296 /* assign a socket to the skb -- consumes sk */
 297 static void
 298 nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
 299 {
 300         skb_orphan(skb);
 301         skb->sk = sk;
 302         skb->destructor = sock_edemux;
 303 }
 304
 305 static unsigned int
 306 tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
 307            u_int32_t mark_mask, u_int32_t mark_value)
 308 {
 309         const struct iphdr *iph = ip_hdr(skb);
 310         struct udphdr _hdr, *hp;
 311         struct sock *sk;
 312
 313         hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
 314         if (hp == NULL)
 315                 return NF_DROP;
 316
 317         /* check if there's an ongoing connection on the packet
 318          * addresses, this happens if the redirect already happened
 319          * and the current packet belongs to an already established
 320          * connection */
 321         sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 322                                    iph->saddr, iph->daddr,
 323                                    hp->source, hp->dest,
 324                                    skb->dev, NFT_LOOKUP_ESTABLISHED);
 325
 326         laddr = tproxy_laddr4(skb, laddr, iph->daddr);
 327         if (!lport)
 328                 lport = hp->dest;
 329
 330         /* UDP has no TCP_TIME_WAIT state, so we never enter here */
 331         if (sk && sk->sk_state == TCP_TIME_WAIT)
 332                 /* reopening a TIME_WAIT connection needs special handling */
 333                 sk = tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
 334         else if (!sk)
 335                 /* no, there's no established connection, check if
 336                  * there's a listener on the redirected addr/port */
 337                 sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
 338                                            iph->saddr, laddr,
 339                                            hp->source, lport,
 340                                            skb->dev, NFT_LOOKUP_LISTENER);
 341
 342         /* NOTE: assign_sock consumes our sk reference */
 343         if (sk && tproxy_sk_is_transparent(sk)) {
 344                 /* This should be in a separate target, but we don't do multiple
 345                    targets on the same rule yet */
 346                 skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
 347
 348                 pr_debug("redirecting: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
 349                          iph->protocol, &iph->daddr, ntohs(hp->dest),
 350                          &laddr, ntohs(lport), skb->mark);
 351
 352                 nf_tproxy_assign_sock(skb, sk);
 353                 return NF_ACCEPT;
 354         }
 355
 356         pr_debug("no socket, dropping: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
 357                  iph->protocol, &iph->saddr, ntohs(hp->source),
 358                  &iph->daddr, ntohs(hp->dest), skb->mark);
 359         return NF_DROP;
 360 }
 361
 362 static unsigned int
 363 tproxy_tg4_v0(struct sk_buff *skb, const struct xt_action_param *par)
 364 {
 365         const struct xt_tproxy_target_info *tgi = par->targinfo;
 366
 367         return tproxy_tg4(par->net, skb, tgi->laddr, tgi->lport, tgi->mark_mask, tgi->mark_value);
 368 }
 369
 370 static unsigned int
 371 tproxy_tg4_v1(struct sk_buff *skb, const struct xt_action_param *par)
 372 {
 373         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 374
 375         return tproxy_tg4(par->net, skb, tgi->laddr.ip, tgi->lport, tgi->mark_mask, tgi->mark_value);
 376 }
 377
 378 #ifdef XT_TPROXY_HAVE_IPV6
 379
 380 static inline const struct in6_addr *
 381 tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
 382               const struct in6_addr *daddr)
 383 {
 384         struct inet6_dev *indev;
 385         struct inet6_ifaddr *ifa;
 386         struct in6_addr *laddr;
 387
 388         if (!ipv6_addr_any(user_laddr))
 389                 return user_laddr;
 390         laddr = NULL;
 391
 392         rcu_read_lock();
 393         indev = __in6_dev_get(skb->dev);
 394         if (indev)
 395                 list_for_each_entry(ifa, &indev->addr_list, if_list) {
 396                         if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
 397                                 continue;
 398
 399                         laddr = &ifa->addr;
 400                         break;
 401                 }
 402         rcu_read_unlock();
 403
 404         return laddr ? laddr : daddr;
 405 }
 406
 407 /**
 408  * tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
 409  * @skb:        The skb being processed.
 410  * @tproto:     Transport protocol.
 411  * @thoff:      Transport protocol header offset.
 412  * @par:        Iptables target parameters.
 413  * @sk:         The TIME_WAIT TCP socket found by the lookup.
 414  *
 415  * We have to handle SYN packets arriving to TIME_WAIT sockets
 416  * differently: instead of reopening the connection we should rather
 417  * redirect the new connection to the proxy if there's a listener
 418  * socket present.
 419  *
 420  * tproxy_handle_time_wait6() consumes the socket reference passed in.
 421  *
 422  * Returns the listener socket if there's one, the TIME_WAIT socket if
 423  * no such listener is found, or NULL if the TCP header is incomplete.
 424  */
 425 static struct sock *
 426 tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
 427                          const struct xt_action_param *par,
 428                          struct sock *sk)
 429 {
 430         const struct ipv6hdr *iph = ipv6_hdr(skb);
 431         struct tcphdr _hdr, *hp;
 432         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 433
 434         hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
 435         if (hp == NULL) {
 436                 inet_twsk_put(inet_twsk(sk));
 437                 return NULL;
 438         }
 439
 440         if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
 441                 /* SYN to a TIME_WAIT socket, we'd rather redirect it
 442                  * to a listener socket if there's one */
 443                 struct sock *sk2;
 444
 445                 sk2 = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 446                                             &iph->saddr,
 447                                             tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr),
 448                                             hp->source,
 449                                             tgi->lport ? tgi->lport : hp->dest,
 450                                             skb->dev, NFT_LOOKUP_LISTENER);
 451                 if (sk2) {
 452                         inet_twsk_deschedule_put(inet_twsk(sk));
 453                         sk = sk2;
 454                 }
 455         }
 456
 457         return sk;
 458 }
 459
 460 static unsigned int
 461 tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
 462 {
 463         const struct ipv6hdr *iph = ipv6_hdr(skb);
 464         const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
 465         struct udphdr _hdr, *hp;
 466         struct sock *sk;
 467         const struct in6_addr *laddr;
 468         __be16 lport;
 469         int thoff = 0;
 470         int tproto;
 471
 472         tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
 473         if (tproto < 0) {
 474                 pr_debug("unable to find transport header in IPv6 packet, dropping\n");
 475                 return NF_DROP;
 476         }
 477
 478         hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
 479         if (hp == NULL) {
 480                 pr_debug("unable to grab transport header contents in IPv6 packet, dropping\n");
 481                 return NF_DROP;
 482         }
 483
 484         /* check if there's an ongoing connection on the packet
 485          * addresses, this happens if the redirect already happened
 486          * and the current packet belongs to an already established
 487          * connection */
 488         sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp, tproto,
 489                                    &iph->saddr, &iph->daddr,
 490                                    hp->source, hp->dest,
 491                                    par->in, NFT_LOOKUP_ESTABLISHED);
 492
 493         laddr = tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
 494         lport = tgi->lport ? tgi->lport : hp->dest;
 495
 496         /* UDP has no TCP_TIME_WAIT state, so we never enter here */
 497         if (sk && sk->sk_state == TCP_TIME_WAIT)
 498                 /* reopening a TIME_WAIT connection needs special handling */
 499                 sk = tproxy_handle_time_wait6(skb, tproto, thoff, par, sk);
 500         else if (!sk)
 501                 /* no there's no established connection, check if
 502                  * there's a listener on the redirected addr/port */
 503                 sk = nf_tproxy_get_sock_v6(par->net, skb, thoff, hp,
 504                                            tproto, &iph->saddr, laddr,
 505                                            hp->source, lport,
 506                                            par->in, NFT_LOOKUP_LISTENER);
 507
 508         /* NOTE: assign_sock consumes our sk reference */
 509         if (sk && tproxy_sk_is_transparent(sk)) {
 510                 /* This should be in a separate target, but we don't do multiple
 511                    targets on the same rule yet */
 512                 skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
 513
 514                 pr_debug("redirecting: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
 515                          tproto, &iph->saddr, ntohs(hp->source),
 516                          laddr, ntohs(lport), skb->mark);
 517
 518                 nf_tproxy_assign_sock(skb, sk);
 519                 return NF_ACCEPT;
 520         }
 521
 522         pr_debug("no socket, dropping: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
 523                  tproto, &iph->saddr, ntohs(hp->source),
 524                  &iph->daddr, ntohs(hp->dest), skb->mark);
 525
 526         return NF_DROP;
 527 }
 528
 529 static int tproxy_tg6_check(const struct xt_tgchk_param *par)
 530 {
 531         const struct ip6t_ip6 *i = par->entryinfo;
 532
 533         if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP) &&
 534             !(i->invflags & IP6T_INV_PROTO))
 535                 return 0;
 536
 537         pr_info("Can be used only in combination with "
 538                 "either -p tcp or -p udp\n");
 539         return -EINVAL;
 540 }
 541 #endif
 542
 543 static int tproxy_tg4_check(const struct xt_tgchk_param *par)
 544 {
 545         const struct ipt_ip *i = par->entryinfo;
 546
 547         if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP)
 548             && !(i->invflags & IPT_INV_PROTO))
 549                 return 0;
 550
 551         pr_info("Can be used only in combination with "
 552                 "either -p tcp or -p udp\n");
 553         return -EINVAL;
 554 }
 555
 556 static struct xt_target tproxy_tg_reg[] __read_mostly = {
 557         {
 558                 .name           = "TPROXY",
 559                 .family         = NFPROTO_IPV4,
 560                 .table          = "mangle",
 561                 .target         = tproxy_tg4_v0,
 562                 .revision       = 0,
 563                 .targetsize     = sizeof(struct xt_tproxy_target_info),
 564                 .checkentry     = tproxy_tg4_check,
 565                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 566                 .me             = THIS_MODULE,
 567         },
 568         {
 569                 .name           = "TPROXY",
 570                 .family         = NFPROTO_IPV4,
 571                 .table          = "mangle",
 572                 .target         = tproxy_tg4_v1,
 573                 .revision       = 1,
 574                 .targetsize     = sizeof(struct xt_tproxy_target_info_v1),
 575                 .checkentry     = tproxy_tg4_check,
 576                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 577                 .me             = THIS_MODULE,
 578         },
 579 #ifdef XT_TPROXY_HAVE_IPV6
 580         {
 581                 .name           = "TPROXY",
 582                 .family         = NFPROTO_IPV6,
 583                 .table          = "mangle",
 584                 .target         = tproxy_tg6_v1,
 585                 .revision       = 1,
 586                 .targetsize     = sizeof(struct xt_tproxy_target_info_v1),
 587                 .checkentry     = tproxy_tg6_check,
 588                 .hooks          = 1 << NF_INET_PRE_ROUTING,
 589                 .me             = THIS_MODULE,
 590         },
 591 #endif
 592
 593 };
 594
 595 static int __init tproxy_tg_init(void)
 596 {
 597         nf_defrag_ipv4_enable();
 598 #ifdef XT_TPROXY_HAVE_IPV6
 599         nf_defrag_ipv6_enable();
 600 #endif
 601
 602         return xt_register_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
 603 }
 604
 605 static void __exit tproxy_tg_exit(void)
 606 {
 607         xt_unregister_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
 608 }
 609
 610 module_init(tproxy_tg_init);
 611 module_exit(tproxy_tg_exit);
 612 MODULE_LICENSE("GPL");
 613 MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs");
 614 MODULE_DESCRIPTION("Netfilter transparent proxy (TPROXY) target module.");
 615 MODULE_ALIAS("ipt_TPROXY");
 616 MODULE_ALIAS("ip6t_TPROXY");