kernel/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         unsigned int bucket;
  52         u_int64_t time_now;
  53 };
  54
  55 static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
  56 {
  57         struct net *net = seq_file_net(seq);
  58         struct ct_iter_state *st = seq->private;
  59         struct hlist_nulls_node *n;
  60
  61         for (st->bucket = 0;
  62              st->bucket < net->ct.htable_size;
  63              st->bucket++) {
  64                 n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));
  65                 if (!is_a_nulls(n))
  66                         return n;
  67         }
  68         return NULL;
  69 }
  70
  71 static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
  72                                       struct hlist_nulls_node *head)
  73 {
  74         struct net *net = seq_file_net(seq);
  75         struct ct_iter_state *st = seq->private;
  76
  77         head = rcu_dereference(hlist_nulls_next_rcu(head));
  78         while (is_a_nulls(head)) {
  79                 if (likely(get_nulls_value(head) == st->bucket)) {
  80                         if (++st->bucket >= net->ct.htable_size)
  81                                 return NULL;
  82                 }
  83                 head = rcu_dereference(
  84                                 hlist_nulls_first_rcu(
  85                                         &net->ct.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         return ct_get_idx(seq, *pos);
 108 }
 109
 110 static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
 111 {
 112         (*pos)++;
 113         return ct_get_next(s, v);
 114 }
 115
 116 static void ct_seq_stop(struct seq_file *s, void *v)
 117         __releases(RCU)
 118 {
 119         rcu_read_unlock();
 120 }
 121
 122 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 123 static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 124 {
 125         int ret;
 126         u32 len;
 127         char *secctx;
 128
 129         ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
 130         if (ret)
 131                 return;
 132
 133         seq_printf(s, "secctx=%s ", secctx);
 134
 135         security_release_secctx(secctx, len);
 136 }
 137 #else
 138 static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 139 {
 140 }
 141 #endif
 142
 143 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 144 static void ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 145 {
 146         struct ct_iter_state *st = s->private;
 147         struct nf_conn_tstamp *tstamp;
 148         s64 delta_time;
 149
 150         tstamp = nf_conn_tstamp_find(ct);
 151         if (tstamp) {
 152                 delta_time = st->time_now - tstamp->start;
 153                 if (delta_time > 0)
 154                         delta_time = div_s64(delta_time, NSEC_PER_SEC);
 155                 else
 156                         delta_time = 0;
 157
 158                 seq_printf(s, "delta-time=%llu ",
 159                            (unsigned long long)delta_time);
 160         }
 161         return;
 162 }
 163 #else
 164 static inline void
 165 ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 166 {
 167 }
 168 #endif
 169
 170 /* return 0 on success, 1 in case of error */
 171 static int ct_seq_show(struct seq_file *s, void *v)
 172 {
 173         struct nf_conntrack_tuple_hash *hash = v;
 174         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
 175         const struct nf_conntrack_l3proto *l3proto;
 176         const struct nf_conntrack_l4proto *l4proto;
 177         int ret = 0;
 178
 179         NF_CT_ASSERT(ct);
 180         if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 181                 return 0;
 182
 183         /* we only want to print DIR_ORIGINAL */
 184         if (NF_CT_DIRECTION(hash))
 185                 goto release;
 186
 187         l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
 188         NF_CT_ASSERT(l3proto);
 189         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 190         NF_CT_ASSERT(l4proto);
 191
 192         ret = -ENOSPC;
 193         seq_printf(s, "%-8s %u %-8s %u %ld ",
 194                    l3proto->name, nf_ct_l3num(ct),
 195                    l4proto->name, nf_ct_protonum(ct),
 196                    timer_pending(&ct->timeout)
 197                    ? (long)(ct->timeout.expires - jiffies)/HZ : 0);
 198
 199         if (l4proto->print_conntrack)
 200                 l4proto->print_conntrack(s, ct);
 201
 202         print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 203                     l3proto, l4proto);
 204
 205         if (seq_has_overflowed(s))
 206                 goto release;
 207
 208         if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
 209                 goto release;
 210
 211         if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
 212                 seq_printf(s, "[UNREPLIED] ");
 213
 214         print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 215                     l3proto, l4proto);
 216
 217         if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
 218                 goto release;
 219
 220         if (test_bit(IPS_ASSURED_BIT, &ct->status))
 221                 seq_printf(s, "[ASSURED] ");
 222
 223         if (seq_has_overflowed(s))
 224                 goto release;
 225
 226 #if defined(CONFIG_NF_CONNTRACK_MARK)
 227         seq_printf(s, "mark=%u ", ct->mark);
 228 #endif
 229
 230         ct_show_secctx(s, ct);
 231
 232 #ifdef CONFIG_NF_CONNTRACK_ZONES
 233         seq_printf(s, "zone=%u ", nf_ct_zone(ct));
 234 #endif
 235
 236         ct_show_delta_time(s, ct);
 237
 238         seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use));
 239
 240         if (seq_has_overflowed(s))
 241                 goto release;
 242
 243         ret = 0;
 244 release:
 245         nf_ct_put(ct);
 246         return ret;
 247 }
 248
 249 static const struct seq_operations ct_seq_ops = {
 250         .start = ct_seq_start,
 251         .next  = ct_seq_next,
 252         .stop  = ct_seq_stop,
 253         .show  = ct_seq_show
 254 };
 255
 256 static int ct_open(struct inode *inode, struct file *file)
 257 {
 258         return seq_open_net(inode, file, &ct_seq_ops,
 259                         sizeof(struct ct_iter_state));
 260 }
 261
 262 static const struct file_operations ct_file_ops = {
 263         .owner   = THIS_MODULE,
 264         .open    = ct_open,
 265         .read    = seq_read,
 266         .llseek  = seq_lseek,
 267         .release = seq_release_net,
 268 };
 269
 270 static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
 271 {
 272         struct net *net = seq_file_net(seq);
 273         int cpu;
 274
 275         if (*pos == 0)
 276                 return SEQ_START_TOKEN;
 277
 278         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
 279                 if (!cpu_possible(cpu))
 280                         continue;
 281                 *pos = cpu + 1;
 282                 return per_cpu_ptr(net->ct.stat, cpu);
 283         }
 284
 285         return NULL;
 286 }
 287
 288 static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 289 {
 290         struct net *net = seq_file_net(seq);
 291         int cpu;
 292
 293         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
 294                 if (!cpu_possible(cpu))
 295                         continue;
 296                 *pos = cpu + 1;
 297                 return per_cpu_ptr(net->ct.stat, cpu);
 298         }
 299
 300         return NULL;
 301 }
 302
 303 static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
 304 {
 305 }
 306
 307 static int ct_cpu_seq_show(struct seq_file *seq, void *v)
 308 {
 309         struct net *net = seq_file_net(seq);
 310         unsigned int nr_conntracks = atomic_read(&net->ct.count);
 311         const struct ip_conntrack_stat *st = v;
 312
 313         if (v == SEQ_START_TOKEN) {
 314                 seq_printf(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");
 315                 return 0;
 316         }
 317
 318         seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
 319                         "%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
 320                    nr_conntracks,
 321                    st->searched,
 322                    st->found,
 323                    st->new,
 324                    st->invalid,
 325                    st->ignore,
 326                    st->delete,
 327                    st->delete_list,
 328                    st->insert,
 329                    st->insert_failed,
 330                    st->drop,
 331                    st->early_drop,
 332                    st->error,
 333
 334                    st->expect_new,
 335                    st->expect_create,
 336                    st->expect_delete,
 337                    st->search_restart
 338                 );
 339         return 0;
 340 }
 341
 342 static const struct seq_operations ct_cpu_seq_ops = {
 343         .start  = ct_cpu_seq_start,
 344         .next   = ct_cpu_seq_next,
 345         .stop   = ct_cpu_seq_stop,
 346         .show   = ct_cpu_seq_show,
 347 };
 348
 349 static int ct_cpu_seq_open(struct inode *inode, struct file *file)
 350 {
 351         return seq_open_net(inode, file, &ct_cpu_seq_ops,
 352                             sizeof(struct seq_net_private));
 353 }
 354
 355 static const struct file_operations ct_cpu_seq_fops = {
 356         .owner   = THIS_MODULE,
 357         .open    = ct_cpu_seq_open,
 358         .read    = seq_read,
 359         .llseek  = seq_lseek,
 360         .release = seq_release_net,
 361 };
 362
 363 static int nf_conntrack_standalone_init_proc(struct net *net)
 364 {
 365         struct proc_dir_entry *pde;
 366
 367         pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
 368         if (!pde)
 369                 goto out_nf_conntrack;
 370
 371         pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
 372                           &ct_cpu_seq_fops);
 373         if (!pde)
 374                 goto out_stat_nf_conntrack;
 375         return 0;
 376
 377 out_stat_nf_conntrack:
 378         remove_proc_entry("nf_conntrack", net->proc_net);
 379 out_nf_conntrack:
 380         return -ENOMEM;
 381 }
 382
 383 static void nf_conntrack_standalone_fini_proc(struct net *net)
 384 {
 385         remove_proc_entry("nf_conntrack", net->proc_net_stat);
 386         remove_proc_entry("nf_conntrack", net->proc_net);
 387 }
 388 #else
 389 static int nf_conntrack_standalone_init_proc(struct net *net)
 390 {
 391         return 0;
 392 }
 393
 394 static void nf_conntrack_standalone_fini_proc(struct net *net)
 395 {
 396 }
 397 #endif /* CONFIG_NF_CONNTRACK_PROCFS */
 398
 399 /* Sysctl support */
 400
 401 #ifdef CONFIG_SYSCTL
 402 /* Log invalid packets of a given protocol */
 403 static int log_invalid_proto_min = 0;
 404 static int log_invalid_proto_max = 255;
 405
 406 static struct ctl_table_header *nf_ct_netfilter_header;
 407
 408 static struct ctl_table nf_ct_sysctl_table[] = {
 409         {
 410                 .procname       = "nf_conntrack_max",
 411                 .data           = &nf_conntrack_max,
 412                 .maxlen         = sizeof(int),
 413                 .mode           = 0644,
 414                 .proc_handler   = proc_dointvec,
 415         },
 416         {
 417                 .procname       = "nf_conntrack_count",
 418                 .data           = &init_net.ct.count,
 419                 .maxlen         = sizeof(int),
 420                 .mode           = 0444,
 421                 .proc_handler   = proc_dointvec,
 422         },
 423         {
 424                 .procname       = "nf_conntrack_buckets",
 425                 .data           = &init_net.ct.htable_size,
 426                 .maxlen         = sizeof(unsigned int),
 427                 .mode           = 0444,
 428                 .proc_handler   = proc_dointvec,
 429         },
 430         {
 431                 .procname       = "nf_conntrack_checksum",
 432                 .data           = &init_net.ct.sysctl_checksum,
 433                 .maxlen         = sizeof(unsigned int),
 434                 .mode           = 0644,
 435                 .proc_handler   = proc_dointvec,
 436         },
 437         {
 438                 .procname       = "nf_conntrack_log_invalid",
 439                 .data           = &init_net.ct.sysctl_log_invalid,
 440                 .maxlen         = sizeof(unsigned int),
 441                 .mode           = 0644,
 442                 .proc_handler   = proc_dointvec_minmax,
 443                 .extra1         = &log_invalid_proto_min,
 444                 .extra2         = &log_invalid_proto_max,
 445         },
 446         {
 447                 .procname       = "nf_conntrack_expect_max",
 448                 .data           = &nf_ct_expect_max,
 449                 .maxlen         = sizeof(int),
 450                 .mode           = 0644,
 451                 .proc_handler   = proc_dointvec,
 452         },
 453         { }
 454 };
 455
 456 #define NET_NF_CONNTRACK_MAX 2089
 457
 458 static struct ctl_table nf_ct_netfilter_table[] = {
 459         {
 460                 .procname       = "nf_conntrack_max",
 461                 .data           = &nf_conntrack_max,
 462                 .maxlen         = sizeof(int),
 463                 .mode           = 0644,
 464                 .proc_handler   = proc_dointvec,
 465         },
 466         { }
 467 };
 468
 469 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 470 {
 471         struct ctl_table *table;
 472
 473         table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
 474                         GFP_KERNEL);
 475         if (!table)
 476                 goto out_kmemdup;
 477
 478         table[1].data = &net->ct.count;
 479         table[2].data = &net->ct.htable_size;
 480         table[3].data = &net->ct.sysctl_checksum;
 481         table[4].data = &net->ct.sysctl_log_invalid;
 482
 483         /* Don't export sysctls to unprivileged users */
 484         if (net->user_ns != &init_user_ns)
 485                 table[0].procname = NULL;
 486
 487         net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
 488         if (!net->ct.sysctl_header)
 489                 goto out_unregister_netfilter;
 490
 491         return 0;
 492
 493 out_unregister_netfilter:
 494         kfree(table);
 495 out_kmemdup:
 496         return -ENOMEM;
 497 }
 498
 499 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 500 {
 501         struct ctl_table *table;
 502
 503         table = net->ct.sysctl_header->ctl_table_arg;
 504         unregister_net_sysctl_table(net->ct.sysctl_header);
 505         kfree(table);
 506 }
 507 #else
 508 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 509 {
 510         return 0;
 511 }
 512
 513 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 514 {
 515 }
 516 #endif /* CONFIG_SYSCTL */
 517
 518 static int nf_conntrack_pernet_init(struct net *net)
 519 {
 520         int ret;
 521
 522         ret = nf_conntrack_init_net(net);
 523         if (ret < 0)
 524                 goto out_init;
 525
 526         ret = nf_conntrack_standalone_init_proc(net);
 527         if (ret < 0)
 528                 goto out_proc;
 529
 530         net->ct.sysctl_checksum = 1;
 531         net->ct.sysctl_log_invalid = 0;
 532         ret = nf_conntrack_standalone_init_sysctl(net);
 533         if (ret < 0)
 534                 goto out_sysctl;
 535
 536         return 0;
 537
 538 out_sysctl:
 539         nf_conntrack_standalone_fini_proc(net);
 540 out_proc:
 541         nf_conntrack_cleanup_net(net);
 542 out_init:
 543         return ret;
 544 }
 545
 546 static void nf_conntrack_pernet_exit(struct list_head *net_exit_list)
 547 {
 548         struct net *net;
 549
 550         list_for_each_entry(net, net_exit_list, exit_list) {
 551                 nf_conntrack_standalone_fini_sysctl(net);
 552                 nf_conntrack_standalone_fini_proc(net);
 553         }
 554         nf_conntrack_cleanup_net_list(net_exit_list);
 555 }
 556
 557 static struct pernet_operations nf_conntrack_net_ops = {
 558         .init           = nf_conntrack_pernet_init,
 559         .exit_batch     = nf_conntrack_pernet_exit,
 560 };
 561
 562 static int __init nf_conntrack_standalone_init(void)
 563 {
 564         int ret = nf_conntrack_init_start();
 565         if (ret < 0)
 566                 goto out_start;
 567
 568 #ifdef CONFIG_SYSCTL
 569         nf_ct_netfilter_header =
 570                 register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
 571         if (!nf_ct_netfilter_header) {
 572                 pr_err("nf_conntrack: can't register to sysctl.\n");
 573                 ret = -ENOMEM;
 574                 goto out_sysctl;
 575         }
 576 #endif
 577
 578         ret = register_pernet_subsys(&nf_conntrack_net_ops);
 579         if (ret < 0)
 580                 goto out_pernet;
 581
 582         nf_conntrack_init_end();
 583         return 0;
 584
 585 out_pernet:
 586 #ifdef CONFIG_SYSCTL
 587         unregister_net_sysctl_table(nf_ct_netfilter_header);
 588 out_sysctl:
 589 #endif
 590         nf_conntrack_cleanup_end();
 591 out_start:
 592         return ret;
 593 }
 594
 595 static void __exit nf_conntrack_standalone_fini(void)
 596 {
 597         nf_conntrack_cleanup_start();
 598         unregister_pernet_subsys(&nf_conntrack_net_ops);
 599 #ifdef CONFIG_SYSCTL
 600         unregister_net_sysctl_table(nf_ct_netfilter_header);
 601 #endif
 602         nf_conntrack_cleanup_end();
 603 }
 604
 605 module_init(nf_conntrack_standalone_init);
 606 module_exit(nf_conntrack_standalone_fini);
 607
 608 /* Some modules need us, but don't depend directly on any symbol.
 609    They should call this. */
 610 void need_conntrack(void)
 611 {
 612 }
 613 EXPORT_SYMBOL_GPL(need_conntrack);