linux/net/netfilter/nf_conntrack_standalone.c
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   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
  36MODULE_LICENSE("GPL");
  37
  38#ifdef CONFIG_NF_CONNTRACK_PROCFS
  39void
  40print_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}
  47EXPORT_SYMBOL_GPL(print_tuple);
  48
  49struct ct_iter_state {
  50        struct seq_net_private p;
  51        unsigned int bucket;
  52        u_int64_t time_now;
  53};
  54
  55static 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
  71static 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
  90static 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
 100static 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
 110static 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
 116static 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
 123static 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
 138static 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
 144static 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
 164static inline void
 165ct_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 */
 171static 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;
 244release:
 245        nf_ct_put(ct);
 246        return ret;
 247}
 248
 249static 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
 256static 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
 262static 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
 270static 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
 288static 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
 303static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
 304{
 305}
 306
 307static 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
 342static 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
 349static 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
 355static 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
 363static 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
 377out_stat_nf_conntrack:
 378        remove_proc_entry("nf_conntrack", net->proc_net);
 379out_nf_conntrack:
 380        return -ENOMEM;
 381}
 382
 383static 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
 389static int nf_conntrack_standalone_init_proc(struct net *net)
 390{
 391        return 0;
 392}
 393
 394static 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 */
 403static int log_invalid_proto_min = 0;
 404static int log_invalid_proto_max = 255;
 405
 406static struct ctl_table_header *nf_ct_netfilter_header;
 407
 408static 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
 458static 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
 469static 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
 493out_unregister_netfilter:
 494        kfree(table);
 495out_kmemdup:
 496        return -ENOMEM;
 497}
 498
 499static 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
 508static int nf_conntrack_standalone_init_sysctl(struct net *net)
 509{
 510        return 0;
 511}
 512
 513static void nf_conntrack_standalone_fini_sysctl(struct net *net)
 514{
 515}
 516#endif /* CONFIG_SYSCTL */
 517
 518static 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
 538out_sysctl:
 539        nf_conntrack_standalone_fini_proc(net);
 540out_proc:
 541        nf_conntrack_cleanup_net(net);
 542out_init:
 543        return ret;
 544}
 545
 546static 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
 557static struct pernet_operations nf_conntrack_net_ops = {
 558        .init           = nf_conntrack_pernet_init,
 559        .exit_batch     = nf_conntrack_pernet_exit,
 560};
 561
 562static 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
 585out_pernet:
 586#ifdef CONFIG_SYSCTL
 587        unregister_net_sysctl_table(nf_ct_netfilter_header);
 588out_sysctl:
 589#endif
 590        nf_conntrack_cleanup_end();
 591out_start:
 592        return ret;
 593}
 594
 595static 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
 605module_init(nf_conntrack_standalone_init);
 606module_exit(nf_conntrack_standalone_fini);
 607
 608/* Some modules need us, but don't depend directly on any symbol.
 609   They should call this. */
 610void need_conntrack(void)
 611{
 612}
 613EXPORT_SYMBOL_GPL(need_conntrack);
 614