net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

   1 /* (C) 1999-2001 Paul `Rusty' Russell
   2  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   9  *      - move L3 protocol dependent part to this file.
  10  * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
  11  *      - add get_features() to support various size of conntrack
  12  *        structures.
  13  *
  14  * Derived from net/ipv4/netfilter/ip_conntrack_standalone.c
  15  */
  16
  17 #include <linux/config.h>
  18 #include <linux/types.h>
  19 #include <linux/ip.h>
  20 #include <linux/netfilter.h>
  21 #include <linux/module.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/icmp.h>
  24 #include <linux/sysctl.h>
  25 #include <net/route.h>
  26 #include <net/ip.h>
  27
  28 #include <linux/netfilter_ipv4.h>
  29 #include <net/netfilter/nf_conntrack.h>
  30 #include <net/netfilter/nf_conntrack_helper.h>
  31 #include <net/netfilter/nf_conntrack_protocol.h>
  32 #include <net/netfilter/nf_conntrack_l3proto.h>
  33 #include <net/netfilter/nf_conntrack_core.h>
  34 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  35
  36 #if 0
  37 #define DEBUGP printk
  38 #else
  39 #define DEBUGP(format, args...)
  40 #endif
  41
  42 DECLARE_PER_CPU(struct nf_conntrack_stat, nf_conntrack_stat);
  43
  44 static int ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
  45                              struct nf_conntrack_tuple *tuple)
  46 {
  47         u_int32_t _addrs[2], *ap;
  48         ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
  49                                 sizeof(u_int32_t) * 2, _addrs);
  50         if (ap == NULL)
  51                 return 0;
  52
  53         tuple->src.u3.ip = ap[0];
  54         tuple->dst.u3.ip = ap[1];
  55
  56         return 1;
  57 }
  58
  59 static int ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
  60                            const struct nf_conntrack_tuple *orig)
  61 {
  62         tuple->src.u3.ip = orig->dst.u3.ip;
  63         tuple->dst.u3.ip = orig->src.u3.ip;
  64
  65         return 1;
  66 }
  67
  68 static int ipv4_print_tuple(struct seq_file *s,
  69                             const struct nf_conntrack_tuple *tuple)
  70 {
  71         return seq_printf(s, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
  72                           NIPQUAD(tuple->src.u3.ip),
  73                           NIPQUAD(tuple->dst.u3.ip));
  74 }
  75
  76 static int ipv4_print_conntrack(struct seq_file *s,
  77                                 const struct nf_conn *conntrack)
  78 {
  79         return 0;
  80 }
  81
  82 /* Returns new sk_buff, or NULL */
  83 static struct sk_buff *
  84 nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
  85 {
  86         skb_orphan(skb);
  87
  88         local_bh_disable();
  89         skb = ip_defrag(skb, user);
  90         local_bh_enable();
  91
  92         if (skb)
  93                 ip_send_check(skb->nh.iph);
  94
  95         return skb;
  96 }
  97
  98 static int
  99 ipv4_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
 100              u_int8_t *protonum)
 101 {
 102         /* Never happen */
 103         if ((*pskb)->nh.iph->frag_off & htons(IP_OFFSET)) {
 104                 if (net_ratelimit()) {
 105                         printk(KERN_ERR "ipv4_prepare: Frag of proto %u (hook=%u)\n",
 106                         (*pskb)->nh.iph->protocol, hooknum);
 107                 }
 108                 return -NF_DROP;
 109         }
 110
 111         *dataoff = (*pskb)->nh.raw - (*pskb)->data + (*pskb)->nh.iph->ihl*4;
 112         *protonum = (*pskb)->nh.iph->protocol;
 113
 114         return NF_ACCEPT;
 115 }
 116
 117 int nat_module_is_loaded = 0;
 118 static u_int32_t ipv4_get_features(const struct nf_conntrack_tuple *tuple)
 119 {
 120         if (nat_module_is_loaded)
 121                 return NF_CT_F_NAT;
 122
 123         return NF_CT_F_BASIC;
 124 }
 125
 126 static unsigned int ipv4_confirm(unsigned int hooknum,
 127                                  struct sk_buff **pskb,
 128                                  const struct net_device *in,
 129                                  const struct net_device *out,
 130                                  int (*okfn)(struct sk_buff *))
 131 {
 132         /* We've seen it coming out the other side: confirm it */
 133         return nf_conntrack_confirm(pskb);
 134 }
 135
 136 static unsigned int ipv4_conntrack_help(unsigned int hooknum,
 137                                       struct sk_buff **pskb,
 138                                       const struct net_device *in,
 139                                       const struct net_device *out,
 140                                       int (*okfn)(struct sk_buff *))
 141 {
 142         struct nf_conn *ct;
 143         enum ip_conntrack_info ctinfo;
 144         struct nf_conn_help *help;
 145
 146         /* This is where we call the helper: as the packet goes out. */
 147         ct = nf_ct_get(*pskb, &ctinfo);
 148         if (!ct)
 149                 return NF_ACCEPT;
 150
 151         help = nfct_help(ct);
 152         if (!help || !help->helper)
 153                 return NF_ACCEPT;
 154
 155         return help->helper->help(pskb,
 156                                (*pskb)->nh.raw - (*pskb)->data
 157                                                + (*pskb)->nh.iph->ihl*4,
 158                                ct, ctinfo);
 159 }
 160
 161 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
 162                                           struct sk_buff **pskb,
 163                                           const struct net_device *in,
 164                                           const struct net_device *out,
 165                                           int (*okfn)(struct sk_buff *))
 166 {
 167 #if !defined(CONFIG_IP_NF_NAT) && !defined(CONFIG_IP_NF_NAT_MODULE)
 168         /* Previously seen (loopback)?  Ignore.  Do this before
 169            fragment check. */
 170         if ((*pskb)->nfct)
 171                 return NF_ACCEPT;
 172 #endif
 173
 174         /* Gather fragments. */
 175         if ((*pskb)->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
 176                 *pskb = nf_ct_ipv4_gather_frags(*pskb,
 177                                                 hooknum == NF_IP_PRE_ROUTING ?
 178                                                 IP_DEFRAG_CONNTRACK_IN :
 179                                                 IP_DEFRAG_CONNTRACK_OUT);
 180                 if (!*pskb)
 181                         return NF_STOLEN;
 182         }
 183         return NF_ACCEPT;
 184 }
 185
 186 static unsigned int ipv4_conntrack_in(unsigned int hooknum,
 187                                       struct sk_buff **pskb,
 188                                       const struct net_device *in,
 189                                       const struct net_device *out,
 190                                       int (*okfn)(struct sk_buff *))
 191 {
 192         return nf_conntrack_in(PF_INET, hooknum, pskb);
 193 }
 194
 195 static unsigned int ipv4_conntrack_local(unsigned int hooknum,
 196                                          struct sk_buff **pskb,
 197                                          const struct net_device *in,
 198                                          const struct net_device *out,
 199                                          int (*okfn)(struct sk_buff *))
 200 {
 201         /* root is playing with raw sockets. */
 202         if ((*pskb)->len < sizeof(struct iphdr)
 203             || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
 204                 if (net_ratelimit())
 205                         printk("ipt_hook: happy cracking.\n");
 206                 return NF_ACCEPT;
 207         }
 208         return nf_conntrack_in(PF_INET, hooknum, pskb);
 209 }
 210
 211 /* Connection tracking may drop packets, but never alters them, so
 212    make it the first hook. */
 213 static struct nf_hook_ops ipv4_conntrack_defrag_ops = {
 214         .hook           = ipv4_conntrack_defrag,
 215         .owner          = THIS_MODULE,
 216         .pf             = PF_INET,
 217         .hooknum        = NF_IP_PRE_ROUTING,
 218         .priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
 219 };
 220
 221 static struct nf_hook_ops ipv4_conntrack_in_ops = {
 222         .hook           = ipv4_conntrack_in,
 223         .owner          = THIS_MODULE,
 224         .pf             = PF_INET,
 225         .hooknum        = NF_IP_PRE_ROUTING,
 226         .priority       = NF_IP_PRI_CONNTRACK,
 227 };
 228
 229 static struct nf_hook_ops ipv4_conntrack_defrag_local_out_ops = {
 230         .hook           = ipv4_conntrack_defrag,
 231         .owner          = THIS_MODULE,
 232         .pf             = PF_INET,
 233         .hooknum        = NF_IP_LOCAL_OUT,
 234         .priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
 235 };
 236
 237 static struct nf_hook_ops ipv4_conntrack_local_out_ops = {
 238         .hook           = ipv4_conntrack_local,
 239         .owner          = THIS_MODULE,
 240         .pf             = PF_INET,
 241         .hooknum        = NF_IP_LOCAL_OUT,
 242         .priority       = NF_IP_PRI_CONNTRACK,
 243 };
 244
 245 /* helpers */
 246 static struct nf_hook_ops ipv4_conntrack_helper_out_ops = {
 247         .hook           = ipv4_conntrack_help,
 248         .owner          = THIS_MODULE,
 249         .pf             = PF_INET,
 250         .hooknum        = NF_IP_POST_ROUTING,
 251         .priority       = NF_IP_PRI_CONNTRACK_HELPER,
 252 };
 253
 254 static struct nf_hook_ops ipv4_conntrack_helper_in_ops = {
 255         .hook           = ipv4_conntrack_help,
 256         .owner          = THIS_MODULE,
 257         .pf             = PF_INET,
 258         .hooknum        = NF_IP_LOCAL_IN,
 259         .priority       = NF_IP_PRI_CONNTRACK_HELPER,
 260 };
 261
 262
 263 /* Refragmenter; last chance. */
 264 static struct nf_hook_ops ipv4_conntrack_out_ops = {
 265         .hook           = ipv4_confirm,
 266         .owner          = THIS_MODULE,
 267         .pf             = PF_INET,
 268         .hooknum        = NF_IP_POST_ROUTING,
 269         .priority       = NF_IP_PRI_CONNTRACK_CONFIRM,
 270 };
 271
 272 static struct nf_hook_ops ipv4_conntrack_local_in_ops = {
 273         .hook           = ipv4_confirm,
 274         .owner          = THIS_MODULE,
 275         .pf             = PF_INET,
 276         .hooknum        = NF_IP_LOCAL_IN,
 277         .priority       = NF_IP_PRI_CONNTRACK_CONFIRM,
 278 };
 279
 280 #ifdef CONFIG_SYSCTL
 281 /* From nf_conntrack_proto_icmp.c */
 282 extern unsigned int nf_ct_icmp_timeout;
 283 static struct ctl_table_header *nf_ct_ipv4_sysctl_header;
 284
 285 static ctl_table nf_ct_sysctl_table[] = {
 286         {
 287                 .ctl_name       = NET_NF_CONNTRACK_ICMP_TIMEOUT,
 288                 .procname       = "nf_conntrack_icmp_timeout",
 289                 .data           = &nf_ct_icmp_timeout,
 290                 .maxlen         = sizeof(unsigned int),
 291                 .mode           = 0644,
 292                 .proc_handler   = &proc_dointvec_jiffies,
 293         },
 294         { .ctl_name = 0 }
 295 };
 296
 297 static ctl_table nf_ct_netfilter_table[] = {
 298         {
 299                 .ctl_name       = NET_NETFILTER,
 300                 .procname       = "netfilter",
 301                 .mode           = 0555,
 302                 .child          = nf_ct_sysctl_table,
 303         },
 304         { .ctl_name = 0 }
 305 };
 306
 307 static ctl_table nf_ct_net_table[] = {
 308         {
 309                 .ctl_name       = CTL_NET,
 310                 .procname       = "net",
 311                 .mode           = 0555,
 312                 .child          = nf_ct_netfilter_table,
 313         },
 314         { .ctl_name = 0 }
 315 };
 316 #endif
 317
 318 /* Fast function for those who don't want to parse /proc (and I don't
 319    blame them). */
 320 /* Reversing the socket's dst/src point of view gives us the reply
 321    mapping. */
 322 static int
 323 getorigdst(struct sock *sk, int optval, void __user *user, int *len)
 324 {
 325         struct inet_sock *inet = inet_sk(sk);
 326         struct nf_conntrack_tuple_hash *h;
 327         struct nf_conntrack_tuple tuple;
 328
 329         NF_CT_TUPLE_U_BLANK(&tuple);
 330         tuple.src.u3.ip = inet->rcv_saddr;
 331         tuple.src.u.tcp.port = inet->sport;
 332         tuple.dst.u3.ip = inet->daddr;
 333         tuple.dst.u.tcp.port = inet->dport;
 334         tuple.src.l3num = PF_INET;
 335         tuple.dst.protonum = IPPROTO_TCP;
 336
 337         /* We only do TCP at the moment: is there a better way? */
 338         if (strcmp(sk->sk_prot->name, "TCP")) {
 339                 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
 340                 return -ENOPROTOOPT;
 341         }
 342
 343         if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
 344                 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
 345                        *len, sizeof(struct sockaddr_in));
 346                 return -EINVAL;
 347         }
 348
 349         h = nf_conntrack_find_get(&tuple, NULL);
 350         if (h) {
 351                 struct sockaddr_in sin;
 352                 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 353
 354                 sin.sin_family = AF_INET;
 355                 sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
 356                         .tuple.dst.u.tcp.port;
 357                 sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
 358                         .tuple.dst.u3.ip;
 359
 360                 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
 361                        NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
 362                 nf_ct_put(ct);
 363                 if (copy_to_user(user, &sin, sizeof(sin)) != 0)
 364                         return -EFAULT;
 365                 else
 366                         return 0;
 367         }
 368         DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
 369                NIPQUAD(tuple.src.u3.ip), ntohs(tuple.src.u.tcp.port),
 370                NIPQUAD(tuple.dst.u3.ip), ntohs(tuple.dst.u.tcp.port));
 371         return -ENOENT;
 372 }
 373
 374 #if defined(CONFIG_NF_CT_NETLINK) || \
 375     defined(CONFIG_NF_CT_NETLINK_MODULE)
 376
 377 #include <linux/netfilter/nfnetlink.h>
 378 #include <linux/netfilter/nfnetlink_conntrack.h>
 379
 380 static int ipv4_tuple_to_nfattr(struct sk_buff *skb,
 381                                 const struct nf_conntrack_tuple *tuple)
 382 {
 383         NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t),
 384                 &tuple->src.u3.ip);
 385         NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t),
 386                 &tuple->dst.u3.ip);
 387         return 0;
 388
 389 nfattr_failure:
 390         return -1;
 391 }
 392
 393 static const size_t cta_min_ip[CTA_IP_MAX] = {
 394         [CTA_IP_V4_SRC-1]       = sizeof(u_int32_t),
 395         [CTA_IP_V4_DST-1]       = sizeof(u_int32_t),
 396 };
 397
 398 static int ipv4_nfattr_to_tuple(struct nfattr *tb[],
 399                                 struct nf_conntrack_tuple *t)
 400 {
 401         if (!tb[CTA_IP_V4_SRC-1] || !tb[CTA_IP_V4_DST-1])
 402                 return -EINVAL;
 403
 404         if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
 405                 return -EINVAL;
 406
 407         t->src.u3.ip =
 408                 *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_SRC-1]);
 409         t->dst.u3.ip =
 410                 *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_DST-1]);
 411
 412         return 0;
 413 }
 414 #endif
 415
 416 static struct nf_sockopt_ops so_getorigdst = {
 417         .pf             = PF_INET,
 418         .get_optmin     = SO_ORIGINAL_DST,
 419         .get_optmax     = SO_ORIGINAL_DST+1,
 420         .get            = &getorigdst,
 421 };
 422
 423 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 = {
 424         .l3proto         = PF_INET,
 425         .name            = "ipv4",
 426         .pkt_to_tuple    = ipv4_pkt_to_tuple,
 427         .invert_tuple    = ipv4_invert_tuple,
 428         .print_tuple     = ipv4_print_tuple,
 429         .print_conntrack = ipv4_print_conntrack,
 430         .prepare         = ipv4_prepare,
 431         .get_features    = ipv4_get_features,
 432 #if defined(CONFIG_NF_CT_NETLINK) || \
 433     defined(CONFIG_NF_CT_NETLINK_MODULE)
 434         .tuple_to_nfattr = ipv4_tuple_to_nfattr,
 435         .nfattr_to_tuple = ipv4_nfattr_to_tuple,
 436 #endif
 437         .me              = THIS_MODULE,
 438 };
 439
 440 extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp4;
 441 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4;
 442 extern struct nf_conntrack_protocol nf_conntrack_protocol_icmp;
 443 static int init_or_cleanup(int init)
 444 {
 445         int ret = 0;
 446
 447         if (!init) goto cleanup;
 448
 449         ret = nf_register_sockopt(&so_getorigdst);
 450         if (ret < 0) {
 451                 printk(KERN_ERR "Unable to register netfilter socket option\n");
 452                 goto cleanup_nothing;
 453         }
 454
 455         ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp4);
 456         if (ret < 0) {
 457                 printk("nf_conntrack_ipv4: can't register tcp.\n");
 458                 goto cleanup_sockopt;
 459         }
 460
 461         ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_udp4);
 462         if (ret < 0) {
 463                 printk("nf_conntrack_ipv4: can't register udp.\n");
 464                 goto cleanup_tcp;
 465         }
 466
 467         ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_icmp);
 468         if (ret < 0) {
 469                 printk("nf_conntrack_ipv4: can't register icmp.\n");
 470                 goto cleanup_udp;
 471         }
 472
 473         ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
 474         if (ret < 0) {
 475                 printk("nf_conntrack_ipv4: can't register ipv4\n");
 476                 goto cleanup_icmp;
 477         }
 478
 479         ret = nf_register_hook(&ipv4_conntrack_defrag_ops);
 480         if (ret < 0) {
 481                 printk("nf_conntrack_ipv4: can't register pre-routing defrag hook.\n");
 482                 goto cleanup_ipv4;
 483         }
 484         ret = nf_register_hook(&ipv4_conntrack_defrag_local_out_ops);
 485         if (ret < 0) {
 486                 printk("nf_conntrack_ipv4: can't register local_out defrag hook.\n");
 487                 goto cleanup_defragops;
 488         }
 489
 490         ret = nf_register_hook(&ipv4_conntrack_in_ops);
 491         if (ret < 0) {
 492                 printk("nf_conntrack_ipv4: can't register pre-routing hook.\n");
 493                 goto cleanup_defraglocalops;
 494         }
 495
 496         ret = nf_register_hook(&ipv4_conntrack_local_out_ops);
 497         if (ret < 0) {
 498                 printk("nf_conntrack_ipv4: can't register local out hook.\n");
 499                 goto cleanup_inops;
 500         }
 501
 502         ret = nf_register_hook(&ipv4_conntrack_helper_in_ops);
 503         if (ret < 0) {
 504                 printk("nf_conntrack_ipv4: can't register local helper hook.\n");
 505                 goto cleanup_inandlocalops;
 506         }
 507
 508         ret = nf_register_hook(&ipv4_conntrack_helper_out_ops);
 509         if (ret < 0) {
 510                 printk("nf_conntrack_ipv4: can't register postrouting helper hook.\n");
 511                 goto cleanup_helperinops;
 512         }
 513
 514         ret = nf_register_hook(&ipv4_conntrack_out_ops);
 515         if (ret < 0) {
 516                 printk("nf_conntrack_ipv4: can't register post-routing hook.\n");
 517                 goto cleanup_helperoutops;
 518         }
 519
 520         ret = nf_register_hook(&ipv4_conntrack_local_in_ops);
 521         if (ret < 0) {
 522                 printk("nf_conntrack_ipv4: can't register local in hook.\n");
 523                 goto cleanup_inoutandlocalops;
 524         }
 525
 526 #ifdef CONFIG_SYSCTL
 527         nf_ct_ipv4_sysctl_header = register_sysctl_table(nf_ct_net_table, 0);
 528         if (nf_ct_ipv4_sysctl_header == NULL) {
 529                 printk("nf_conntrack: can't register to sysctl.\n");
 530                 ret = -ENOMEM;
 531                 goto cleanup_localinops;
 532         }
 533 #endif
 534         return ret;
 535
 536  cleanup:
 537         synchronize_net();
 538 #ifdef CONFIG_SYSCTL
 539         unregister_sysctl_table(nf_ct_ipv4_sysctl_header);
 540  cleanup_localinops:
 541 #endif
 542         nf_unregister_hook(&ipv4_conntrack_local_in_ops);
 543  cleanup_inoutandlocalops:
 544         nf_unregister_hook(&ipv4_conntrack_out_ops);
 545  cleanup_helperoutops:
 546         nf_unregister_hook(&ipv4_conntrack_helper_out_ops);
 547  cleanup_helperinops:
 548         nf_unregister_hook(&ipv4_conntrack_helper_in_ops);
 549  cleanup_inandlocalops:
 550         nf_unregister_hook(&ipv4_conntrack_local_out_ops);
 551  cleanup_inops:
 552         nf_unregister_hook(&ipv4_conntrack_in_ops);
 553  cleanup_defraglocalops:
 554         nf_unregister_hook(&ipv4_conntrack_defrag_local_out_ops);
 555  cleanup_defragops:
 556         nf_unregister_hook(&ipv4_conntrack_defrag_ops);
 557  cleanup_ipv4:
 558         nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
 559  cleanup_icmp:
 560         nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmp);
 561  cleanup_udp:
 562         nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp4);
 563  cleanup_tcp:
 564         nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp4);
 565  cleanup_sockopt:
 566         nf_unregister_sockopt(&so_getorigdst);
 567  cleanup_nothing:
 568         return ret;
 569 }
 570
 571 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
 572 MODULE_LICENSE("GPL");
 573
 574 static int __init nf_conntrack_l3proto_ipv4_init(void)
 575 {
 576         need_conntrack();
 577         return init_or_cleanup(1);
 578 }
 579
 580 static void __exit nf_conntrack_l3proto_ipv4_fini(void)
 581 {
 582         init_or_cleanup(0);
 583 }
 584
 585 module_init(nf_conntrack_l3proto_ipv4_init);
 586 module_exit(nf_conntrack_l3proto_ipv4_fini);
 587
 588 EXPORT_SYMBOL(nf_ct_ipv4_gather_frags);