net/netfilter/nf_conntrack_standalone.c

   1 /* (C) 1999-2001 Paul `Rusty' Russell
   2  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   3  * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
   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
  10 #include <linux/types.h>
  11 #include <linux/netfilter.h>
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/percpu.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/security.h>
  20 #include <net/net_namespace.h>
  21 #ifdef CONFIG_SYSCTL
  22 #include <linux/sysctl.h>
  23 #endif
  24
  25 #include <net/netfilter/nf_conntrack.h>
  26 #include <net/netfilter/nf_conntrack_core.h>
  27 #include <net/netfilter/nf_conntrack_l3proto.h>
  28 #include <net/netfilter/nf_conntrack_l4proto.h>
  29 #include <net/netfilter/nf_conntrack_expect.h>
  30 #include <net/netfilter/nf_conntrack_helper.h>
  31 #include <net/netfilter/nf_conntrack_acct.h>
  32 #include <net/netfilter/nf_conntrack_zones.h>
  33 #include <net/netfilter/nf_conntrack_timestamp.h>
  34 #include <linux/rculist_nulls.h>
  35
  36 MODULE_LICENSE("GPL");
  37
  38 #ifdef CONFIG_NF_CONNTRACK_PROCFS
  39 void
  40 print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
  41             const struct nf_conntrack_l3proto *l3proto,
  42             const struct nf_conntrack_l4proto *l4proto)
  43 {
  44         l3proto->print_tuple(s, tuple);
  45         l4proto->print_tuple(s, tuple);
  46 }
  47 EXPORT_SYMBOL_GPL(print_tuple);
  48
  49 struct ct_iter_state {
  50         struct seq_net_private p;
  51         struct hlist_nulls_head *hash;
  52         unsigned int htable_size;
  53         unsigned int bucket;
  54         u_int64_t time_now;
  55 };
  56
  57 static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
  58 {
  59         struct ct_iter_state *st = seq->private;
  60         struct hlist_nulls_node *n;
  61
  62         for (st->bucket = 0;
  63              st->bucket < st->htable_size;
  64              st->bucket++) {
  65                 n = rcu_dereference(
  66                         hlist_nulls_first_rcu(&st->hash[st->bucket]));
  67                 if (!is_a_nulls(n))
  68                         return n;
  69         }
  70         return NULL;
  71 }
  72
  73 static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
  74                                       struct hlist_nulls_node *head)
  75 {
  76         struct ct_iter_state *st = seq->private;
  77
  78         head = rcu_dereference(hlist_nulls_next_rcu(head));
  79         while (is_a_nulls(head)) {
  80                 if (likely(get_nulls_value(head) == st->bucket)) {
  81                         if (++st->bucket >= st->htable_size)
  82                                 return NULL;
  83                 }
  84                 head = rcu_dereference(
  85                         hlist_nulls_first_rcu(&st->hash[st->bucket]));
  86         }
  87         return head;
  88 }
  89
  90 static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)
  91 {
  92         struct hlist_nulls_node *head = ct_get_first(seq);
  93
  94         if (head)
  95                 while (pos && (head = ct_get_next(seq, head)))
  96                         pos--;
  97         return pos ? NULL : head;
  98 }
  99
 100 static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
 101         __acquires(RCU)
 102 {
 103         struct ct_iter_state *st = seq->private;
 104
 105         st->time_now = ktime_get_real_ns();
 106         rcu_read_lock();
 107
 108         nf_conntrack_get_ht(&st->hash, &st->htable_size);
 109         return ct_get_idx(seq, *pos);
 110 }
 111
 112 static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
 113 {
 114         (*pos)++;
 115         return ct_get_next(s, v);
 116 }
 117
 118 static void ct_seq_stop(struct seq_file *s, void *v)
 119         __releases(RCU)
 120 {
 121         rcu_read_unlock();
 122 }
 123
 124 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 125 static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 126 {
 127         int ret;
 128         u32 len;
 129         char *secctx;
 130
 131         ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
 132         if (ret)
 133                 return;
 134
 135         seq_printf(s, "secctx=%s ", secctx);
 136
 137         security_release_secctx(secctx, len);
 138 }
 139 #else
 140 static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 141 {
 142 }
 143 #endif
 144
 145 #ifdef CONFIG_NF_CONNTRACK_ZONES
 146 static void ct_show_zone(struct seq_file *s, const struct nf_conn *ct,
 147                          int dir)
 148 {
 149         const struct nf_conntrack_zone *zone = nf_ct_zone(ct);
 150
 151         if (zone->dir != dir)
 152                 return;
 153         switch (zone->dir) {
 154         case NF_CT_DEFAULT_ZONE_DIR:
 155                 seq_printf(s, "zone=%u ", zone->id);
 156                 break;
 157         case NF_CT_ZONE_DIR_ORIG:
 158                 seq_printf(s, "zone-orig=%u ", zone->id);
 159                 break;
 160         case NF_CT_ZONE_DIR_REPL:
 161                 seq_printf(s, "zone-reply=%u ", zone->id);
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167 #else
 168 static inline void ct_show_zone(struct seq_file *s, const struct nf_conn *ct,
 169                                 int dir)
 170 {
 171 }
 172 #endif
 173
 174 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 175 static void ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 176 {
 177         struct ct_iter_state *st = s->private;
 178         struct nf_conn_tstamp *tstamp;
 179         s64 delta_time;
 180
 181         tstamp = nf_conn_tstamp_find(ct);
 182         if (tstamp) {
 183                 delta_time = st->time_now - tstamp->start;
 184                 if (delta_time > 0)
 185                         delta_time = div_s64(delta_time, NSEC_PER_SEC);
 186                 else
 187                         delta_time = 0;
 188
 189                 seq_printf(s, "delta-time=%llu ",
 190                            (unsigned long long)delta_time);
 191         }
 192         return;
 193 }
 194 #else
 195 static inline void
 196 ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 197 {
 198 }
 199 #endif
 200
 201 /* return 0 on success, 1 in case of error */
 202 static int ct_seq_show(struct seq_file *s, void *v)
 203 {
 204         struct nf_conntrack_tuple_hash *hash = v;
 205         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
 206         const struct nf_conntrack_l3proto *l3proto;
 207         const struct nf_conntrack_l4proto *l4proto;
 208         struct net *net = seq_file_net(s);
 209         int ret = 0;
 210
 211         NF_CT_ASSERT(ct);
 212         if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 213                 return 0;
 214
 215         if (nf_ct_should_gc(ct)) {
 216                 nf_ct_kill(ct);
 217                 goto release;
 218         }
 219
 220         /* we only want to print DIR_ORIGINAL */
 221         if (NF_CT_DIRECTION(hash))
 222                 goto release;
 223
 224         if (!net_eq(nf_ct_net(ct), net))
 225                 goto release;
 226
 227         l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
 228         NF_CT_ASSERT(l3proto);
 229         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 230         NF_CT_ASSERT(l4proto);
 231
 232         ret = -ENOSPC;
 233         seq_printf(s, "%-8s %u %-8s %u %ld ",
 234                    l3proto->name, nf_ct_l3num(ct),
 235                    l4proto->name, nf_ct_protonum(ct),
 236                    nf_ct_expires(ct)  / HZ);
 237
 238         if (l4proto->print_conntrack)
 239                 l4proto->print_conntrack(s, ct);
 240
 241         print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 242                     l3proto, l4proto);
 243
 244         ct_show_zone(s, ct, NF_CT_ZONE_DIR_ORIG);
 245
 246         if (seq_has_overflowed(s))
 247                 goto release;
 248
 249         if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
 250                 goto release;
 251
 252         if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
 253                 seq_puts(s, "[UNREPLIED] ");
 254
 255         print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 256                     l3proto, l4proto);
 257
 258         ct_show_zone(s, ct, NF_CT_ZONE_DIR_REPL);
 259
 260         if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
 261                 goto release;
 262
 263         if (test_bit(IPS_ASSURED_BIT, &ct->status))
 264                 seq_puts(s, "[ASSURED] ");
 265
 266         if (seq_has_overflowed(s))
 267                 goto release;
 268
 269 #if defined(CONFIG_NF_CONNTRACK_MARK)
 270         seq_printf(s, "mark=%u ", ct->mark);
 271 #endif
 272
 273         ct_show_secctx(s, ct);
 274         ct_show_zone(s, ct, NF_CT_DEFAULT_ZONE_DIR);
 275         ct_show_delta_time(s, ct);
 276
 277         seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use));
 278
 279         if (seq_has_overflowed(s))
 280                 goto release;
 281
 282         ret = 0;
 283 release:
 284         nf_ct_put(ct);
 285         return ret;
 286 }
 287
 288 static const struct seq_operations ct_seq_ops = {
 289         .start = ct_seq_start,
 290         .next  = ct_seq_next,
 291         .stop  = ct_seq_stop,
 292         .show  = ct_seq_show
 293 };
 294
 295 static int ct_open(struct inode *inode, struct file *file)
 296 {
 297         return seq_open_net(inode, file, &ct_seq_ops,
 298                         sizeof(struct ct_iter_state));
 299 }
 300
 301 static const struct file_operations ct_file_ops = {
 302         .owner   = THIS_MODULE,
 303         .open    = ct_open,
 304         .read    = seq_read,
 305         .llseek  = seq_lseek,
 306         .release = seq_release_net,
 307 };
 308
 309 static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
 310 {
 311         struct net *net = seq_file_net(seq);
 312         int cpu;
 313
 314         if (*pos == 0)
 315                 return SEQ_START_TOKEN;
 316
 317         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
 318                 if (!cpu_possible(cpu))
 319                         continue;
 320                 *pos = cpu + 1;
 321                 return per_cpu_ptr(net->ct.stat, cpu);
 322         }
 323
 324         return NULL;
 325 }
 326
 327 static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 328 {
 329         struct net *net = seq_file_net(seq);
 330         int cpu;
 331
 332         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
 333                 if (!cpu_possible(cpu))
 334                         continue;
 335                 *pos = cpu + 1;
 336                 return per_cpu_ptr(net->ct.stat, cpu);
 337         }
 338
 339         return NULL;
 340 }
 341
 342 static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
 343 {
 344 }
 345
 346 static int ct_cpu_seq_show(struct seq_file *seq, void *v)
 347 {
 348         struct net *net = seq_file_net(seq);
 349         unsigned int nr_conntracks = atomic_read(&net->ct.count);
 350         const struct ip_conntrack_stat *st = v;
 351
 352         if (v == SEQ_START_TOKEN) {
 353                 seq_puts(seq, "entries  searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error  expect_new expect_create expect_delete search_restart\n");
 354                 return 0;
 355         }
 356
 357         seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
 358                         "%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
 359                    nr_conntracks,
 360                    0,
 361                    st->found,
 362                    0,
 363                    st->invalid,
 364                    st->ignore,
 365                    0,
 366                    0,
 367                    st->insert,
 368                    st->insert_failed,
 369                    st->drop,
 370                    st->early_drop,
 371                    st->error,
 372
 373                    st->expect_new,
 374                    st->expect_create,
 375                    st->expect_delete,
 376                    st->search_restart
 377                 );
 378         return 0;
 379 }
 380
 381 static const struct seq_operations ct_cpu_seq_ops = {
 382         .start  = ct_cpu_seq_start,
 383         .next   = ct_cpu_seq_next,
 384         .stop   = ct_cpu_seq_stop,
 385         .show   = ct_cpu_seq_show,
 386 };
 387
 388 static int ct_cpu_seq_open(struct inode *inode, struct file *file)
 389 {
 390         return seq_open_net(inode, file, &ct_cpu_seq_ops,
 391                             sizeof(struct seq_net_private));
 392 }
 393
 394 static const struct file_operations ct_cpu_seq_fops = {
 395         .owner   = THIS_MODULE,
 396         .open    = ct_cpu_seq_open,
 397         .read    = seq_read,
 398         .llseek  = seq_lseek,
 399         .release = seq_release_net,
 400 };
 401
 402 static int nf_conntrack_standalone_init_proc(struct net *net)
 403 {
 404         struct proc_dir_entry *pde;
 405         kuid_t root_uid;
 406         kgid_t root_gid;
 407
 408         pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
 409         if (!pde)
 410                 goto out_nf_conntrack;
 411
 412         root_uid = make_kuid(net->user_ns, 0);
 413         root_gid = make_kgid(net->user_ns, 0);
 414         if (uid_valid(root_uid) && gid_valid(root_gid))
 415                 proc_set_user(pde, root_uid, root_gid);
 416
 417         pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
 418                           &ct_cpu_seq_fops);
 419         if (!pde)
 420                 goto out_stat_nf_conntrack;
 421         return 0;
 422
 423 out_stat_nf_conntrack:
 424         remove_proc_entry("nf_conntrack", net->proc_net);
 425 out_nf_conntrack:
 426         return -ENOMEM;
 427 }
 428
 429 static void nf_conntrack_standalone_fini_proc(struct net *net)
 430 {
 431         remove_proc_entry("nf_conntrack", net->proc_net_stat);
 432         remove_proc_entry("nf_conntrack", net->proc_net);
 433 }
 434 #else
 435 static int nf_conntrack_standalone_init_proc(struct net *net)
 436 {
 437         return 0;
 438 }
 439
 440 static void nf_conntrack_standalone_fini_proc(struct net *net)
 441 {
 442 }
 443 #endif /* CONFIG_NF_CONNTRACK_PROCFS */
 444
 445 /* Sysctl support */
 446
 447 #ifdef CONFIG_SYSCTL
 448 /* Log invalid packets of a given protocol */
 449 static int log_invalid_proto_min __read_mostly;
 450 static int log_invalid_proto_max __read_mostly = 255;
 451
 452 /* size the user *wants to set */
 453 static unsigned int nf_conntrack_htable_size_user __read_mostly;
 454
 455 extern unsigned int nf_conntrack_default_on;
 456 unsigned int nf_conntrack_default_on __read_mostly = 1;
 457
 458 static int
 459 nf_conntrack_hash_sysctl(struct ctl_table *table, int write,
 460                          void __user *buffer, size_t *lenp, loff_t *ppos)
 461 {
 462         int ret;
 463
 464         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 465         if (ret < 0 || !write)
 466                 return ret;
 467
 468         /* update ret, we might not be able to satisfy request */
 469         ret = nf_conntrack_hash_resize(nf_conntrack_htable_size_user);
 470
 471         /* update it to the actual value used by conntrack */
 472         nf_conntrack_htable_size_user = nf_conntrack_htable_size;
 473         return ret;
 474 }
 475
 476 static struct ctl_table_header *nf_ct_netfilter_header;
 477
 478 static struct ctl_table nf_ct_sysctl_table[] = {
 479         {
 480                 .procname       = "nf_conntrack_max",
 481                 .data           = &nf_conntrack_max,
 482                 .maxlen         = sizeof(int),
 483                 .mode           = 0644,
 484                 .proc_handler   = proc_dointvec,
 485         },
 486         {
 487                 .procname       = "nf_conntrack_count",
 488                 .data           = &init_net.ct.count,
 489                 .maxlen         = sizeof(int),
 490                 .mode           = 0444,
 491                 .proc_handler   = proc_dointvec,
 492         },
 493         {
 494                 .procname       = "nf_conntrack_buckets",
 495                 .data           = &nf_conntrack_htable_size_user,
 496                 .maxlen         = sizeof(unsigned int),
 497                 .mode           = 0644,
 498                 .proc_handler   = nf_conntrack_hash_sysctl,
 499         },
 500         {
 501                 .procname       = "nf_conntrack_checksum",
 502                 .data           = &init_net.ct.sysctl_checksum,
 503                 .maxlen         = sizeof(unsigned int),
 504                 .mode           = 0644,
 505                 .proc_handler   = proc_dointvec,
 506         },
 507         {
 508                 .procname       = "nf_conntrack_log_invalid",
 509                 .data           = &init_net.ct.sysctl_log_invalid,
 510                 .maxlen         = sizeof(unsigned int),
 511                 .mode           = 0644,
 512                 .proc_handler   = proc_dointvec_minmax,
 513                 .extra1         = &log_invalid_proto_min,
 514                 .extra2         = &log_invalid_proto_max,
 515         },
 516         {
 517                 .procname       = "nf_conntrack_expect_max",
 518                 .data           = &nf_ct_expect_max,
 519                 .maxlen         = sizeof(int),
 520                 .mode           = 0644,
 521                 .proc_handler   = proc_dointvec,
 522         },
 523         {
 524                 .procname       = "nf_conntrack_default_on",
 525                 .data           = &nf_conntrack_default_on,
 526                 .maxlen         = sizeof(unsigned int),
 527                 .mode           = 0644,
 528                 .proc_handler   = proc_dointvec,
 529         },
 530         { }
 531 };
 532
 533 static struct ctl_table nf_ct_netfilter_table[] = {
 534         {
 535                 .procname       = "nf_conntrack_max",
 536                 .data           = &nf_conntrack_max,
 537                 .maxlen         = sizeof(int),
 538                 .mode           = 0644,
 539                 .proc_handler   = proc_dointvec,
 540         },
 541         { }
 542 };
 543
 544 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 545 {
 546         struct ctl_table *table;
 547
 548         table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
 549                         GFP_KERNEL);
 550         if (!table)
 551                 goto out_kmemdup;
 552
 553         table[1].data = &net->ct.count;
 554         table[3].data = &net->ct.sysctl_checksum;
 555         table[4].data = &net->ct.sysctl_log_invalid;
 556
 557         /* Don't export sysctls to unprivileged users */
 558         if (net->user_ns != &init_user_ns)
 559                 table[0].procname = NULL;
 560
 561         if (!net_eq(&init_net, net))
 562                 table[2].mode = 0444;
 563
 564         net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
 565         if (!net->ct.sysctl_header)
 566                 goto out_unregister_netfilter;
 567
 568         return 0;
 569
 570 out_unregister_netfilter:
 571         kfree(table);
 572 out_kmemdup:
 573         return -ENOMEM;
 574 }
 575
 576 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 577 {
 578         struct ctl_table *table;
 579
 580         table = net->ct.sysctl_header->ctl_table_arg;
 581         unregister_net_sysctl_table(net->ct.sysctl_header);
 582         kfree(table);
 583 }
 584 #else
 585 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 586 {
 587         return 0;
 588 }
 589
 590 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 591 {
 592 }
 593 #endif /* CONFIG_SYSCTL */
 594
 595 static int nf_conntrack_pernet_init(struct net *net)
 596 {
 597         int ret;
 598
 599         ret = nf_conntrack_init_net(net);
 600         if (ret < 0)
 601                 goto out_init;
 602
 603         ret = nf_conntrack_standalone_init_proc(net);
 604         if (ret < 0)
 605                 goto out_proc;
 606
 607         net->ct.sysctl_checksum = 1;
 608         net->ct.sysctl_log_invalid = 0;
 609         ret = nf_conntrack_standalone_init_sysctl(net);
 610         if (ret < 0)
 611                 goto out_sysctl;
 612
 613         return 0;
 614
 615 out_sysctl:
 616         nf_conntrack_standalone_fini_proc(net);
 617 out_proc:
 618         nf_conntrack_cleanup_net(net);
 619 out_init:
 620         return ret;
 621 }
 622
 623 static void nf_conntrack_pernet_exit(struct list_head *net_exit_list)
 624 {
 625         struct net *net;
 626
 627         list_for_each_entry(net, net_exit_list, exit_list) {
 628                 nf_conntrack_standalone_fini_sysctl(net);
 629                 nf_conntrack_standalone_fini_proc(net);
 630         }
 631         nf_conntrack_cleanup_net_list(net_exit_list);
 632 }
 633
 634 static struct pernet_operations nf_conntrack_net_ops = {
 635         .init           = nf_conntrack_pernet_init,
 636         .exit_batch     = nf_conntrack_pernet_exit,
 637 };
 638
 639 static int __init nf_conntrack_standalone_init(void)
 640 {
 641         int ret = nf_conntrack_init_start();
 642         if (ret < 0)
 643                 goto out_start;
 644
 645         BUILD_BUG_ON(SKB_NFCT_PTRMASK != NFCT_PTRMASK);
 646         BUILD_BUG_ON(NFCT_INFOMASK <= IP_CT_NUMBER);
 647
 648 #ifdef CONFIG_SYSCTL
 649         nf_ct_netfilter_header =
 650                 register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
 651         if (!nf_ct_netfilter_header) {
 652                 pr_err("nf_conntrack: can't register to sysctl.\n");
 653                 ret = -ENOMEM;
 654                 goto out_sysctl;
 655         }
 656
 657         nf_conntrack_htable_size_user = nf_conntrack_htable_size;
 658 #endif
 659
 660         ret = register_pernet_subsys(&nf_conntrack_net_ops);
 661         if (ret < 0)
 662                 goto out_pernet;
 663
 664         nf_conntrack_init_end();
 665         return 0;
 666
 667 out_pernet:
 668 #ifdef CONFIG_SYSCTL
 669         unregister_net_sysctl_table(nf_ct_netfilter_header);
 670 out_sysctl:
 671 #endif
 672         nf_conntrack_cleanup_end();
 673 out_start:
 674         return ret;
 675 }
 676
 677 static void __exit nf_conntrack_standalone_fini(void)
 678 {
 679         nf_conntrack_cleanup_start();
 680         unregister_pernet_subsys(&nf_conntrack_net_ops);
 681 #ifdef CONFIG_SYSCTL
 682         unregister_net_sysctl_table(nf_ct_netfilter_header);
 683 #endif
 684         nf_conntrack_cleanup_end();
 685 }
 686
 687 module_init(nf_conntrack_standalone_init);
 688 module_exit(nf_conntrack_standalone_fini);
 689
 690 /* Some modules need us, but don't depend directly on any symbol.
 691    They should call this. */
 692 void need_conntrack(void)
 693 {
 694 }
 695 EXPORT_SYMBOL_GPL(need_conntrack);