net/netfilter/nf_conntrack_standalone.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
   9 #include <linux/types.h>
  10 #include <linux/netfilter.h>
  11 #include <linux/slab.h>
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/percpu.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/security.h>
  19 #include <net/net_namespace.h>
  20 #ifdef CONFIG_SYSCTL
  21 #include <linux/sysctl.h>
  22 #endif
  23
  24 #include <net/netfilter/nf_conntrack.h>
  25 #include <net/netfilter/nf_conntrack_core.h>
  26 #include <net/netfilter/nf_conntrack_l3proto.h>
  27 #include <net/netfilter/nf_conntrack_l4proto.h>
  28 #include <net/netfilter/nf_conntrack_expect.h>
  29 #include <net/netfilter/nf_conntrack_helper.h>
  30 #include <net/netfilter/nf_conntrack_acct.h>
  31 #include <net/netfilter/nf_conntrack_zones.h>
  32 #include <net/netfilter/nf_conntrack_timestamp.h>
  33 #include <linux/rculist_nulls.h>
  34
  35 MODULE_LICENSE("GPL");
  36
  37 #ifdef CONFIG_NF_CONNTRACK_PROCFS
  38 int
  39 print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
  40             const struct nf_conntrack_l3proto *l3proto,
  41             const struct nf_conntrack_l4proto *l4proto)
  42 {
  43         return l3proto->print_tuple(s, tuple) || l4proto->print_tuple(s, tuple);
  44 }
  45 EXPORT_SYMBOL_GPL(print_tuple);
  46
  47 struct ct_iter_state {
  48         struct seq_net_private p;
  49         unsigned int bucket;
  50         u_int64_t time_now;
  51 };
  52
  53 static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
  54 {
  55         struct net *net = seq_file_net(seq);
  56         struct ct_iter_state *st = seq->private;
  57         struct hlist_nulls_node *n;
  58
  59         for (st->bucket = 0;
  60              st->bucket < net->ct.htable_size;
  61              st->bucket++) {
  62                 n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));
  63                 if (!is_a_nulls(n))
  64                         return n;
  65         }
  66         return NULL;
  67 }
  68
  69 static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
  70                                       struct hlist_nulls_node *head)
  71 {
  72         struct net *net = seq_file_net(seq);
  73         struct ct_iter_state *st = seq->private;
  74
  75         head = rcu_dereference(hlist_nulls_next_rcu(head));
  76         while (is_a_nulls(head)) {
  77                 if (likely(get_nulls_value(head) == st->bucket)) {
  78                         if (++st->bucket >= net->ct.htable_size)
  79                                 return NULL;
  80                 }
  81                 head = rcu_dereference(
  82                                 hlist_nulls_first_rcu(
  83                                         &net->ct.hash[st->bucket]));
  84         }
  85         return head;
  86 }
  87
  88 static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)
  89 {
  90         struct hlist_nulls_node *head = ct_get_first(seq);
  91
  92         if (head)
  93                 while (pos && (head = ct_get_next(seq, head)))
  94                         pos--;
  95         return pos ? NULL : head;
  96 }
  97
  98 static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
  99         __acquires(RCU)
 100 {
 101         struct ct_iter_state *st = seq->private;
 102
 103         st->time_now = ktime_to_ns(ktime_get_real());
 104         rcu_read_lock();
 105         return ct_get_idx(seq, *pos);
 106 }
 107
 108 static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
 109 {
 110         (*pos)++;
 111         return ct_get_next(s, v);
 112 }
 113
 114 static void ct_seq_stop(struct seq_file *s, void *v)
 115         __releases(RCU)
 116 {
 117         rcu_read_unlock();
 118 }
 119
 120 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 121 static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 122 {
 123         int ret;
 124         u32 len;
 125         char *secctx;
 126
 127         ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
 128         if (ret)
 129                 return 0;
 130
 131         ret = seq_printf(s, "secctx=%s ", secctx);
 132
 133         security_release_secctx(secctx, len);
 134         return ret;
 135 }
 136 #else
 137 static inline int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 138 {
 139         return 0;
 140 }
 141 #endif
 142
 143 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 144 static int 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                 return seq_printf(s, "delta-time=%llu ",
 159                                   (unsigned long long)delta_time);
 160         }
 161         return 0;
 162 }
 163 #else
 164 static inline int
 165 ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 166 {
 167         return 0;
 168 }
 169 #endif
 170
 171 /* return 0 on success, 1 in case of error */
 172 static int ct_seq_show(struct seq_file *s, void *v)
 173 {
 174         struct nf_conntrack_tuple_hash *hash = v;
 175         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
 176         const struct nf_conntrack_l3proto *l3proto;
 177         const struct nf_conntrack_l4proto *l4proto;
 178         int ret = 0;
 179
 180         NF_CT_ASSERT(ct);
 181         if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 182                 return 0;
 183
 184         /* we only want to print DIR_ORIGINAL */
 185         if (NF_CT_DIRECTION(hash))
 186                 goto release;
 187
 188         l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
 189         NF_CT_ASSERT(l3proto);
 190         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 191         NF_CT_ASSERT(l4proto);
 192
 193         ret = -ENOSPC;
 194         if (seq_printf(s, "%-8s %u %-8s %u %ld ",
 195                        l3proto->name, nf_ct_l3num(ct),
 196                        l4proto->name, nf_ct_protonum(ct),
 197                        timer_pending(&ct->timeout)
 198                        ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)
 199                 goto release;
 200
 201         if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))
 202                 goto release;
 203
 204         if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 205                         l3proto, l4proto))
 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                 if (seq_printf(s, "[UNREPLIED] "))
 213                         goto release;
 214
 215         if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 216                         l3proto, l4proto))
 217                 goto release;
 218
 219         if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
 220                 goto release;
 221
 222         if (test_bit(IPS_ASSURED_BIT, &ct->status))
 223                 if (seq_printf(s, "[ASSURED] "))
 224                         goto release;
 225
 226 #if defined(CONFIG_NF_CONNTRACK_MARK)
 227         if (seq_printf(s, "mark=%u ", ct->mark))
 228                 goto release;
 229 #endif
 230
 231         if (ct_show_secctx(s, ct))
 232                 goto release;
 233
 234 #ifdef CONFIG_NF_CONNTRACK_ZONES
 235         if (seq_printf(s, "zone=%u ", nf_ct_zone(ct)))
 236                 goto release;
 237 #endif
 238
 239         if (ct_show_delta_time(s, ct))
 240                 goto release;
 241
 242         if (seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use)))
 243                 goto release;
 244
 245         ret = 0;
 246 release:
 247         nf_ct_put(ct);
 248         return ret;
 249 }
 250
 251 static const struct seq_operations ct_seq_ops = {
 252         .start = ct_seq_start,
 253         .next  = ct_seq_next,
 254         .stop  = ct_seq_stop,
 255         .show  = ct_seq_show
 256 };
 257
 258 static int ct_open(struct inode *inode, struct file *file)
 259 {
 260         return seq_open_net(inode, file, &ct_seq_ops,
 261                         sizeof(struct ct_iter_state));
 262 }
 263
 264 static const struct file_operations ct_file_ops = {
 265         .owner   = THIS_MODULE,
 266         .open    = ct_open,
 267         .read    = seq_read,
 268         .llseek  = seq_lseek,
 269         .release = seq_release_net,
 270 };
 271
 272 static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
 273 {
 274         struct net *net = seq_file_net(seq);
 275         int cpu;
 276
 277         if (*pos == 0)
 278                 return SEQ_START_TOKEN;
 279
 280         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
 281                 if (!cpu_possible(cpu))
 282                         continue;
 283                 *pos = cpu + 1;
 284                 return per_cpu_ptr(net->ct.stat, cpu);
 285         }
 286
 287         return NULL;
 288 }
 289
 290 static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 291 {
 292         struct net *net = seq_file_net(seq);
 293         int cpu;
 294
 295         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
 296                 if (!cpu_possible(cpu))
 297                         continue;
 298                 *pos = cpu + 1;
 299                 return per_cpu_ptr(net->ct.stat, cpu);
 300         }
 301
 302         return NULL;
 303 }
 304
 305 static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
 306 {
 307 }
 308
 309 static int ct_cpu_seq_show(struct seq_file *seq, void *v)
 310 {
 311         struct net *net = seq_file_net(seq);
 312         unsigned int nr_conntracks = atomic_read(&net->ct.count);
 313         const struct ip_conntrack_stat *st = v;
 314
 315         if (v == SEQ_START_TOKEN) {
 316                 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");
 317                 return 0;
 318         }
 319
 320         seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
 321                         "%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
 322                    nr_conntracks,
 323                    st->searched,
 324                    st->found,
 325                    st->new,
 326                    st->invalid,
 327                    st->ignore,
 328                    st->delete,
 329                    st->delete_list,
 330                    st->insert,
 331                    st->insert_failed,
 332                    st->drop,
 333                    st->early_drop,
 334                    st->error,
 335
 336                    st->expect_new,
 337                    st->expect_create,
 338                    st->expect_delete,
 339                    st->search_restart
 340                 );
 341         return 0;
 342 }
 343
 344 static const struct seq_operations ct_cpu_seq_ops = {
 345         .start  = ct_cpu_seq_start,
 346         .next   = ct_cpu_seq_next,
 347         .stop   = ct_cpu_seq_stop,
 348         .show   = ct_cpu_seq_show,
 349 };
 350
 351 static int ct_cpu_seq_open(struct inode *inode, struct file *file)
 352 {
 353         return seq_open_net(inode, file, &ct_cpu_seq_ops,
 354                             sizeof(struct seq_net_private));
 355 }
 356
 357 static const struct file_operations ct_cpu_seq_fops = {
 358         .owner   = THIS_MODULE,
 359         .open    = ct_cpu_seq_open,
 360         .read    = seq_read,
 361         .llseek  = seq_lseek,
 362         .release = seq_release_net,
 363 };
 364
 365 static int nf_conntrack_standalone_init_proc(struct net *net)
 366 {
 367         struct proc_dir_entry *pde;
 368
 369         pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
 370         if (!pde)
 371                 goto out_nf_conntrack;
 372
 373         pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
 374                           &ct_cpu_seq_fops);
 375         if (!pde)
 376                 goto out_stat_nf_conntrack;
 377         return 0;
 378
 379 out_stat_nf_conntrack:
 380         remove_proc_entry("nf_conntrack", net->proc_net);
 381 out_nf_conntrack:
 382         return -ENOMEM;
 383 }
 384
 385 static void nf_conntrack_standalone_fini_proc(struct net *net)
 386 {
 387         remove_proc_entry("nf_conntrack", net->proc_net_stat);
 388         remove_proc_entry("nf_conntrack", net->proc_net);
 389 }
 390 #else
 391 static int nf_conntrack_standalone_init_proc(struct net *net)
 392 {
 393         return 0;
 394 }
 395
 396 static void nf_conntrack_standalone_fini_proc(struct net *net)
 397 {
 398 }
 399 #endif /* CONFIG_NF_CONNTRACK_PROCFS */
 400
 401 /* Sysctl support */
 402
 403 #ifdef CONFIG_SYSCTL
 404 /* Log invalid packets of a given protocol */
 405 static int log_invalid_proto_min = 0;
 406 static int log_invalid_proto_max = 255;
 407
 408 static struct ctl_table_header *nf_ct_netfilter_header;
 409
 410 static ctl_table nf_ct_sysctl_table[] = {
 411         {
 412                 .procname       = "nf_conntrack_max",
 413                 .data           = &nf_conntrack_max,
 414                 .maxlen         = sizeof(int),
 415                 .mode           = 0644,
 416                 .proc_handler   = proc_dointvec,
 417         },
 418         {
 419                 .procname       = "nf_conntrack_count",
 420                 .data           = &init_net.ct.count,
 421                 .maxlen         = sizeof(int),
 422                 .mode           = 0444,
 423                 .proc_handler   = proc_dointvec,
 424         },
 425         {
 426                 .procname       = "nf_conntrack_buckets",
 427                 .data           = &init_net.ct.htable_size,
 428                 .maxlen         = sizeof(unsigned int),
 429                 .mode           = 0444,
 430                 .proc_handler   = proc_dointvec,
 431         },
 432         {
 433                 .procname       = "nf_conntrack_checksum",
 434                 .data           = &init_net.ct.sysctl_checksum,
 435                 .maxlen         = sizeof(unsigned int),
 436                 .mode           = 0644,
 437                 .proc_handler   = proc_dointvec,
 438         },
 439         {
 440                 .procname       = "nf_conntrack_log_invalid",
 441                 .data           = &init_net.ct.sysctl_log_invalid,
 442                 .maxlen         = sizeof(unsigned int),
 443                 .mode           = 0644,
 444                 .proc_handler   = proc_dointvec_minmax,
 445                 .extra1         = &log_invalid_proto_min,
 446                 .extra2         = &log_invalid_proto_max,
 447         },
 448         {
 449                 .procname       = "nf_conntrack_expect_max",
 450                 .data           = &nf_ct_expect_max,
 451                 .maxlen         = sizeof(int),
 452                 .mode           = 0644,
 453                 .proc_handler   = proc_dointvec,
 454         },
 455         { }
 456 };
 457
 458 #define NET_NF_CONNTRACK_MAX 2089
 459
 460 static ctl_table nf_ct_netfilter_table[] = {
 461         {
 462                 .procname       = "nf_conntrack_max",
 463                 .data           = &nf_conntrack_max,
 464                 .maxlen         = sizeof(int),
 465                 .mode           = 0644,
 466                 .proc_handler   = proc_dointvec,
 467         },
 468         { }
 469 };
 470
 471 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 472 {
 473         struct ctl_table *table;
 474
 475         table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
 476                         GFP_KERNEL);
 477         if (!table)
 478                 goto out_kmemdup;
 479
 480         table[1].data = &net->ct.count;
 481         table[2].data = &net->ct.htable_size;
 482         table[3].data = &net->ct.sysctl_checksum;
 483         table[4].data = &net->ct.sysctl_log_invalid;
 484
 485         /* Don't export sysctls to unprivileged users */
 486         if (net->user_ns != &init_user_ns)
 487                 table[0].procname = NULL;
 488
 489         net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
 490         if (!net->ct.sysctl_header)
 491                 goto out_unregister_netfilter;
 492
 493         return 0;
 494
 495 out_unregister_netfilter:
 496         kfree(table);
 497 out_kmemdup:
 498         return -ENOMEM;
 499 }
 500
 501 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 502 {
 503         struct ctl_table *table;
 504
 505         table = net->ct.sysctl_header->ctl_table_arg;
 506         unregister_net_sysctl_table(net->ct.sysctl_header);
 507         kfree(table);
 508 }
 509 #else
 510 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 511 {
 512         return 0;
 513 }
 514
 515 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 516 {
 517 }
 518 #endif /* CONFIG_SYSCTL */
 519
 520 static int nf_conntrack_pernet_init(struct net *net)
 521 {
 522         int ret;
 523
 524         ret = nf_conntrack_init_net(net);
 525         if (ret < 0)
 526                 goto out_init;
 527
 528         ret = nf_conntrack_standalone_init_proc(net);
 529         if (ret < 0)
 530                 goto out_proc;
 531
 532         net->ct.sysctl_checksum = 1;
 533         net->ct.sysctl_log_invalid = 0;
 534         ret = nf_conntrack_standalone_init_sysctl(net);
 535         if (ret < 0)
 536                 goto out_sysctl;
 537
 538         return 0;
 539
 540 out_sysctl:
 541         nf_conntrack_standalone_fini_proc(net);
 542 out_proc:
 543         nf_conntrack_cleanup_net(net);
 544 out_init:
 545         return ret;
 546 }
 547
 548 static void nf_conntrack_pernet_exit(struct net *net)
 549 {
 550         nf_conntrack_standalone_fini_sysctl(net);
 551         nf_conntrack_standalone_fini_proc(net);
 552         nf_conntrack_cleanup_net(net);
 553 }
 554
 555 static struct pernet_operations nf_conntrack_net_ops = {
 556         .init = nf_conntrack_pernet_init,
 557         .exit = nf_conntrack_pernet_exit,
 558 };
 559
 560 static int __init nf_conntrack_standalone_init(void)
 561 {
 562         int ret = nf_conntrack_init_start();
 563         if (ret < 0)
 564                 goto out_start;
 565
 566 #ifdef CONFIG_SYSCTL
 567         nf_ct_netfilter_header =
 568                 register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
 569         if (!nf_ct_netfilter_header) {
 570                 pr_err("nf_conntrack: can't register to sysctl.\n");
 571                 ret = -ENOMEM;
 572                 goto out_sysctl;
 573         }
 574 #endif
 575
 576         ret = register_pernet_subsys(&nf_conntrack_net_ops);
 577         if (ret < 0)
 578                 goto out_pernet;
 579
 580         nf_conntrack_init_end();
 581         return 0;
 582
 583 out_pernet:
 584 #ifdef CONFIG_SYSCTL
 585         unregister_net_sysctl_table(nf_ct_netfilter_header);
 586 out_sysctl:
 587 #endif
 588         nf_conntrack_cleanup_end();
 589 out_start:
 590         return ret;
 591 }
 592
 593 static void __exit nf_conntrack_standalone_fini(void)
 594 {
 595         nf_conntrack_cleanup_start();
 596         unregister_pernet_subsys(&nf_conntrack_net_ops);
 597 #ifdef CONFIG_SYSCTL
 598         unregister_net_sysctl_table(nf_ct_netfilter_header);
 599 #endif
 600         nf_conntrack_cleanup_end();
 601 }
 602
 603 module_init(nf_conntrack_standalone_init);
 604 module_exit(nf_conntrack_standalone_fini);
 605
 606 /* Some modules need us, but don't depend directly on any symbol.
 607    They should call this. */
 608 void need_conntrack(void)
 609 {
 610 }
 611 EXPORT_SYMBOL_GPL(need_conntrack);