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 int
  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         return l3proto->print_tuple(s, tuple) || l4proto->print_tuple(s, tuple);
  45 }
  46 EXPORT_SYMBOL_GPL(print_tuple);
  47
  48 struct ct_iter_state {
  49         struct seq_net_private p;
  50         unsigned int bucket;
  51         u_int64_t time_now;
  52 };
  53
  54 static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
  55 {
  56         struct net *net = seq_file_net(seq);
  57         struct ct_iter_state *st = seq->private;
  58         struct hlist_nulls_node *n;
  59
  60         for (st->bucket = 0;
  61              st->bucket < net->ct.htable_size;
  62              st->bucket++) {
  63                 n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));
  64                 if (!is_a_nulls(n))
  65                         return n;
  66         }
  67         return NULL;
  68 }
  69
  70 static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
  71                                       struct hlist_nulls_node *head)
  72 {
  73         struct net *net = seq_file_net(seq);
  74         struct ct_iter_state *st = seq->private;
  75
  76         head = rcu_dereference(hlist_nulls_next_rcu(head));
  77         while (is_a_nulls(head)) {
  78                 if (likely(get_nulls_value(head) == st->bucket)) {
  79                         if (++st->bucket >= net->ct.htable_size)
  80                                 return NULL;
  81                 }
  82                 head = rcu_dereference(
  83                                 hlist_nulls_first_rcu(
  84                                         &net->ct.hash[st->bucket]));
  85         }
  86         return head;
  87 }
  88
  89 static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)
  90 {
  91         struct hlist_nulls_node *head = ct_get_first(seq);
  92
  93         if (head)
  94                 while (pos && (head = ct_get_next(seq, head)))
  95                         pos--;
  96         return pos ? NULL : head;
  97 }
  98
  99 static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
 100         __acquires(RCU)
 101 {
 102         struct ct_iter_state *st = seq->private;
 103
 104         st->time_now = ktime_get_real_ns();
 105         rcu_read_lock();
 106         return ct_get_idx(seq, *pos);
 107 }
 108
 109 static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
 110 {
 111         (*pos)++;
 112         return ct_get_next(s, v);
 113 }
 114
 115 static void ct_seq_stop(struct seq_file *s, void *v)
 116         __releases(RCU)
 117 {
 118         rcu_read_unlock();
 119 }
 120
 121 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 122 static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 123 {
 124         int ret;
 125         u32 len;
 126         char *secctx;
 127
 128         ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
 129         if (ret)
 130                 return 0;
 131
 132         ret = seq_printf(s, "secctx=%s ", secctx);
 133
 134         security_release_secctx(secctx, len);
 135         return ret;
 136 }
 137 #else
 138 static inline int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 139 {
 140         return 0;
 141 }
 142 #endif
 143
 144 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 145 static int ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 146 {
 147         struct ct_iter_state *st = s->private;
 148         struct nf_conn_tstamp *tstamp;
 149         s64 delta_time;
 150
 151         tstamp = nf_conn_tstamp_find(ct);
 152         if (tstamp) {
 153                 delta_time = st->time_now - tstamp->start;
 154                 if (delta_time > 0)
 155                         delta_time = div_s64(delta_time, NSEC_PER_SEC);
 156                 else
 157                         delta_time = 0;
 158
 159                 return seq_printf(s, "delta-time=%llu ",
 160                                   (unsigned long long)delta_time);
 161         }
 162         return 0;
 163 }
 164 #else
 165 static inline int
 166 ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 167 {
 168         return 0;
 169 }
 170 #endif
 171
 172 /* return 0 on success, 1 in case of error */
 173 static int ct_seq_show(struct seq_file *s, void *v)
 174 {
 175         struct nf_conntrack_tuple_hash *hash = v;
 176         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
 177         const struct nf_conntrack_l3proto *l3proto;
 178         const struct nf_conntrack_l4proto *l4proto;
 179         int ret = 0;
 180
 181         NF_CT_ASSERT(ct);
 182         if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 183                 return 0;
 184
 185         /* we only want to print DIR_ORIGINAL */
 186         if (NF_CT_DIRECTION(hash))
 187                 goto release;
 188
 189         l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
 190         NF_CT_ASSERT(l3proto);
 191         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 192         NF_CT_ASSERT(l4proto);
 193
 194         ret = -ENOSPC;
 195         if (seq_printf(s, "%-8s %u %-8s %u %ld ",
 196                        l3proto->name, nf_ct_l3num(ct),
 197                        l4proto->name, nf_ct_protonum(ct),
 198                        timer_pending(&ct->timeout)
 199                        ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)
 200                 goto release;
 201
 202         if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))
 203                 goto release;
 204
 205         if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 206                         l3proto, l4proto))
 207                 goto release;
 208
 209         if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
 210                 goto release;
 211
 212         if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
 213                 if (seq_printf(s, "[UNREPLIED] "))
 214                         goto release;
 215
 216         if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 217                         l3proto, l4proto))
 218                 goto release;
 219
 220         if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
 221                 goto release;
 222
 223         if (test_bit(IPS_ASSURED_BIT, &ct->status))
 224                 if (seq_printf(s, "[ASSURED] "))
 225                         goto release;
 226
 227 #if defined(CONFIG_NF_CONNTRACK_MARK)
 228         if (seq_printf(s, "mark=%u ", ct->mark))
 229                 goto release;
 230 #endif
 231
 232         if (ct_show_secctx(s, ct))
 233                 goto release;
 234
 235 #ifdef CONFIG_NF_CONNTRACK_ZONES
 236         if (seq_printf(s, "zone=%u ", nf_ct_zone(ct)))
 237                 goto release;
 238 #endif
 239
 240         if (ct_show_delta_time(s, ct))
 241                 goto release;
 242
 243         if (seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use)))
 244                 goto release;
 245
 246         ret = 0;
 247 release:
 248         nf_ct_put(ct);
 249         return ret;
 250 }
 251
 252 static const struct seq_operations ct_seq_ops = {
 253         .start = ct_seq_start,
 254         .next  = ct_seq_next,
 255         .stop  = ct_seq_stop,
 256         .show  = ct_seq_show
 257 };
 258
 259 static int ct_open(struct inode *inode, struct file *file)
 260 {
 261         return seq_open_net(inode, file, &ct_seq_ops,
 262                         sizeof(struct ct_iter_state));
 263 }
 264
 265 static const struct file_operations ct_file_ops = {
 266         .owner   = THIS_MODULE,
 267         .open    = ct_open,
 268         .read    = seq_read,
 269         .llseek  = seq_lseek,
 270         .release = seq_release_net,
 271 };
 272
 273 static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
 274 {
 275         struct net *net = seq_file_net(seq);
 276         int cpu;
 277
 278         if (*pos == 0)
 279                 return SEQ_START_TOKEN;
 280
 281         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
 282                 if (!cpu_possible(cpu))
 283                         continue;
 284                 *pos = cpu + 1;
 285                 return per_cpu_ptr(net->ct.stat, cpu);
 286         }
 287
 288         return NULL;
 289 }
 290
 291 static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 292 {
 293         struct net *net = seq_file_net(seq);
 294         int cpu;
 295
 296         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
 297                 if (!cpu_possible(cpu))
 298                         continue;
 299                 *pos = cpu + 1;
 300                 return per_cpu_ptr(net->ct.stat, cpu);
 301         }
 302
 303         return NULL;
 304 }
 305
 306 static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
 307 {
 308 }
 309
 310 static int ct_cpu_seq_show(struct seq_file *seq, void *v)
 311 {
 312         struct net *net = seq_file_net(seq);
 313         unsigned int nr_conntracks = atomic_read(&net->ct.count);
 314         const struct ip_conntrack_stat *st = v;
 315
 316         if (v == SEQ_START_TOKEN) {
 317                 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");
 318                 return 0;
 319         }
 320
 321         seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
 322                         "%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
 323                    nr_conntracks,
 324                    st->searched,
 325                    st->found,
 326                    st->new,
 327                    st->invalid,
 328                    st->ignore,
 329                    st->delete,
 330                    st->delete_list,
 331                    st->insert,
 332                    st->insert_failed,
 333                    st->drop,
 334                    st->early_drop,
 335                    st->error,
 336
 337                    st->expect_new,
 338                    st->expect_create,
 339                    st->expect_delete,
 340                    st->search_restart
 341                 );
 342         return 0;
 343 }
 344
 345 static const struct seq_operations ct_cpu_seq_ops = {
 346         .start  = ct_cpu_seq_start,
 347         .next   = ct_cpu_seq_next,
 348         .stop   = ct_cpu_seq_stop,
 349         .show   = ct_cpu_seq_show,
 350 };
 351
 352 static int ct_cpu_seq_open(struct inode *inode, struct file *file)
 353 {
 354         return seq_open_net(inode, file, &ct_cpu_seq_ops,
 355                             sizeof(struct seq_net_private));
 356 }
 357
 358 static const struct file_operations ct_cpu_seq_fops = {
 359         .owner   = THIS_MODULE,
 360         .open    = ct_cpu_seq_open,
 361         .read    = seq_read,
 362         .llseek  = seq_lseek,
 363         .release = seq_release_net,
 364 };
 365
 366 static int nf_conntrack_standalone_init_proc(struct net *net)
 367 {
 368         struct proc_dir_entry *pde;
 369
 370         pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
 371         if (!pde)
 372                 goto out_nf_conntrack;
 373
 374         pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
 375                           &ct_cpu_seq_fops);
 376         if (!pde)
 377                 goto out_stat_nf_conntrack;
 378         return 0;
 379
 380 out_stat_nf_conntrack:
 381         remove_proc_entry("nf_conntrack", net->proc_net);
 382 out_nf_conntrack:
 383         return -ENOMEM;
 384 }
 385
 386 static void nf_conntrack_standalone_fini_proc(struct net *net)
 387 {
 388         remove_proc_entry("nf_conntrack", net->proc_net_stat);
 389         remove_proc_entry("nf_conntrack", net->proc_net);
 390 }
 391 #else
 392 static int nf_conntrack_standalone_init_proc(struct net *net)
 393 {
 394         return 0;
 395 }
 396
 397 static void nf_conntrack_standalone_fini_proc(struct net *net)
 398 {
 399 }
 400 #endif /* CONFIG_NF_CONNTRACK_PROCFS */
 401
 402 /* Sysctl support */
 403
 404 #ifdef CONFIG_SYSCTL
 405 /* Log invalid packets of a given protocol */
 406 static int log_invalid_proto_min = 0;
 407 static int log_invalid_proto_max = 255;
 408
 409 static struct ctl_table_header *nf_ct_netfilter_header;
 410
 411 static struct ctl_table nf_ct_sysctl_table[] = {
 412         {
 413                 .procname       = "nf_conntrack_max",
 414                 .data           = &nf_conntrack_max,
 415                 .maxlen         = sizeof(int),
 416                 .mode           = 0644,
 417                 .proc_handler   = proc_dointvec,
 418         },
 419         {
 420                 .procname       = "nf_conntrack_count",
 421                 .data           = &init_net.ct.count,
 422                 .maxlen         = sizeof(int),
 423                 .mode           = 0444,
 424                 .proc_handler   = proc_dointvec,
 425         },
 426         {
 427                 .procname       = "nf_conntrack_buckets",
 428                 .data           = &init_net.ct.htable_size,
 429                 .maxlen         = sizeof(unsigned int),
 430                 .mode           = 0444,
 431                 .proc_handler   = proc_dointvec,
 432         },
 433         {
 434                 .procname       = "nf_conntrack_checksum",
 435                 .data           = &init_net.ct.sysctl_checksum,
 436                 .maxlen         = sizeof(unsigned int),
 437                 .mode           = 0644,
 438                 .proc_handler   = proc_dointvec,
 439         },
 440         {
 441                 .procname       = "nf_conntrack_log_invalid",
 442                 .data           = &init_net.ct.sysctl_log_invalid,
 443                 .maxlen         = sizeof(unsigned int),
 444                 .mode           = 0644,
 445                 .proc_handler   = proc_dointvec_minmax,
 446                 .extra1         = &log_invalid_proto_min,
 447                 .extra2         = &log_invalid_proto_max,
 448         },
 449         {
 450                 .procname       = "nf_conntrack_expect_max",
 451                 .data           = &nf_ct_expect_max,
 452                 .maxlen         = sizeof(int),
 453                 .mode           = 0644,
 454                 .proc_handler   = proc_dointvec,
 455         },
 456         { }
 457 };
 458
 459 #define NET_NF_CONNTRACK_MAX 2089
 460
 461 static struct ctl_table nf_ct_netfilter_table[] = {
 462         {
 463                 .procname       = "nf_conntrack_max",
 464                 .data           = &nf_conntrack_max,
 465                 .maxlen         = sizeof(int),
 466                 .mode           = 0644,
 467                 .proc_handler   = proc_dointvec,
 468         },
 469         { }
 470 };
 471
 472 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 473 {
 474         struct ctl_table *table;
 475
 476         table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
 477                         GFP_KERNEL);
 478         if (!table)
 479                 goto out_kmemdup;
 480
 481         table[1].data = &net->ct.count;
 482         table[2].data = &net->ct.htable_size;
 483         table[3].data = &net->ct.sysctl_checksum;
 484         table[4].data = &net->ct.sysctl_log_invalid;
 485
 486         /* Don't export sysctls to unprivileged users */
 487         if (net->user_ns != &init_user_ns)
 488                 table[0].procname = NULL;
 489
 490         net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
 491         if (!net->ct.sysctl_header)
 492                 goto out_unregister_netfilter;
 493
 494         return 0;
 495
 496 out_unregister_netfilter:
 497         kfree(table);
 498 out_kmemdup:
 499         return -ENOMEM;
 500 }
 501
 502 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 503 {
 504         struct ctl_table *table;
 505
 506         table = net->ct.sysctl_header->ctl_table_arg;
 507         unregister_net_sysctl_table(net->ct.sysctl_header);
 508         kfree(table);
 509 }
 510 #else
 511 static int nf_conntrack_standalone_init_sysctl(struct net *net)
 512 {
 513         return 0;
 514 }
 515
 516 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 517 {
 518 }
 519 #endif /* CONFIG_SYSCTL */
 520
 521 static int nf_conntrack_pernet_init(struct net *net)
 522 {
 523         int ret;
 524
 525         ret = nf_conntrack_init_net(net);
 526         if (ret < 0)
 527                 goto out_init;
 528
 529         ret = nf_conntrack_standalone_init_proc(net);
 530         if (ret < 0)
 531                 goto out_proc;
 532
 533         net->ct.sysctl_checksum = 1;
 534         net->ct.sysctl_log_invalid = 0;
 535         ret = nf_conntrack_standalone_init_sysctl(net);
 536         if (ret < 0)
 537                 goto out_sysctl;
 538
 539         return 0;
 540
 541 out_sysctl:
 542         nf_conntrack_standalone_fini_proc(net);
 543 out_proc:
 544         nf_conntrack_cleanup_net(net);
 545 out_init:
 546         return ret;
 547 }
 548
 549 static void nf_conntrack_pernet_exit(struct list_head *net_exit_list)
 550 {
 551         struct net *net;
 552
 553         list_for_each_entry(net, net_exit_list, exit_list) {
 554                 nf_conntrack_standalone_fini_sysctl(net);
 555                 nf_conntrack_standalone_fini_proc(net);
 556         }
 557         nf_conntrack_cleanup_net_list(net_exit_list);
 558 }
 559
 560 static struct pernet_operations nf_conntrack_net_ops = {
 561         .init           = nf_conntrack_pernet_init,
 562         .exit_batch     = nf_conntrack_pernet_exit,
 563 };
 564
 565 static int __init nf_conntrack_standalone_init(void)
 566 {
 567         int ret = nf_conntrack_init_start();
 568         if (ret < 0)
 569                 goto out_start;
 570
 571 #ifdef CONFIG_SYSCTL
 572         nf_ct_netfilter_header =
 573                 register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
 574         if (!nf_ct_netfilter_header) {
 575                 pr_err("nf_conntrack: can't register to sysctl.\n");
 576                 ret = -ENOMEM;
 577                 goto out_sysctl;
 578         }
 579 #endif
 580
 581         ret = register_pernet_subsys(&nf_conntrack_net_ops);
 582         if (ret < 0)
 583                 goto out_pernet;
 584
 585         nf_conntrack_init_end();
 586         return 0;
 587
 588 out_pernet:
 589 #ifdef CONFIG_SYSCTL
 590         unregister_net_sysctl_table(nf_ct_netfilter_header);
 591 out_sysctl:
 592 #endif
 593         nf_conntrack_cleanup_end();
 594 out_start:
 595         return ret;
 596 }
 597
 598 static void __exit nf_conntrack_standalone_fini(void)
 599 {
 600         nf_conntrack_cleanup_start();
 601         unregister_pernet_subsys(&nf_conntrack_net_ops);
 602 #ifdef CONFIG_SYSCTL
 603         unregister_net_sysctl_table(nf_ct_netfilter_header);
 604 #endif
 605         nf_conntrack_cleanup_end();
 606 }
 607
 608 module_init(nf_conntrack_standalone_init);
 609 module_exit(nf_conntrack_standalone_fini);
 610
 611 /* Some modules need us, but don't depend directly on any symbol.
 612    They should call this. */
 613 void need_conntrack(void)
 614 {
 615 }
 616 EXPORT_SYMBOL_GPL(need_conntrack);