net/netfilter/nf_conntrack_core.c

   1 /* Connection state tracking for netfilter.  This is separated from,
   2    but required by, the NAT layer; it can also be used by an iptables
   3    extension. */
   4
   5 /* (C) 1999-2001 Paul `Rusty' Russell
   6  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
   7  * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/netfilter.h>
  16 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/proc_fs.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/stddef.h>
  21 #include <linux/slab.h>
  22 #include <linux/random.h>
  23 #include <linux/jhash.h>
  24 #include <linux/err.h>
  25 #include <linux/percpu.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/notifier.h>
  28 #include <linux/kernel.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/socket.h>
  31 #include <linux/mm.h>
  32
  33 #include <net/netfilter/nf_conntrack.h>
  34 #include <net/netfilter/nf_conntrack_l3proto.h>
  35 #include <net/netfilter/nf_conntrack_l4proto.h>
  36 #include <net/netfilter/nf_conntrack_expect.h>
  37 #include <net/netfilter/nf_conntrack_helper.h>
  38 #include <net/netfilter/nf_conntrack_core.h>
  39 #include <net/netfilter/nf_conntrack_extend.h>
  40
  41 #define NF_CONNTRACK_VERSION    "0.5.0"
  42
  43 DEFINE_SPINLOCK(nf_conntrack_lock);
  44 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  45
  46 /* nf_conntrack_standalone needs this */
  47 atomic_t nf_conntrack_count = ATOMIC_INIT(0);
  48 EXPORT_SYMBOL_GPL(nf_conntrack_count);
  49
  50 unsigned int nf_conntrack_htable_size __read_mostly;
  51 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
  52
  53 int nf_conntrack_max __read_mostly;
  54 EXPORT_SYMBOL_GPL(nf_conntrack_max);
  55
  56 struct hlist_head *nf_conntrack_hash __read_mostly;
  57 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
  58
  59 struct nf_conn nf_conntrack_untracked __read_mostly;
  60 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
  61
  62 unsigned int nf_ct_log_invalid __read_mostly;
  63 HLIST_HEAD(unconfirmed);
  64 static int nf_conntrack_vmalloc __read_mostly;
  65 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  66
  67 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
  68 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
  69
  70 static int nf_conntrack_hash_rnd_initted;
  71 static unsigned int nf_conntrack_hash_rnd;
  72
  73 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  74                                   unsigned int size, unsigned int rnd)
  75 {
  76         unsigned int n;
  77         u_int32_t h;
  78
  79         /* The direction must be ignored, so we hash everything up to the
  80          * destination ports (which is a multiple of 4) and treat the last
  81          * three bytes manually.
  82          */
  83         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  84         h = jhash2((u32 *)tuple, n,
  85                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  86                           tuple->dst.protonum));
  87
  88         return ((u64)h * size) >> 32;
  89 }
  90
  91 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  92 {
  93         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  94                                 nf_conntrack_hash_rnd);
  95 }
  96
  97 int
  98 nf_ct_get_tuple(const struct sk_buff *skb,
  99                 unsigned int nhoff,
 100                 unsigned int dataoff,
 101                 u_int16_t l3num,
 102                 u_int8_t protonum,
 103                 struct nf_conntrack_tuple *tuple,
 104                 const struct nf_conntrack_l3proto *l3proto,
 105                 const struct nf_conntrack_l4proto *l4proto)
 106 {
 107         NF_CT_TUPLE_U_BLANK(tuple);
 108
 109         tuple->src.l3num = l3num;
 110         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 111                 return 0;
 112
 113         tuple->dst.protonum = protonum;
 114         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 115
 116         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 117 }
 118 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 119
 120 int nf_ct_get_tuplepr(const struct sk_buff *skb,
 121                       unsigned int nhoff,
 122                       u_int16_t l3num,
 123                       struct nf_conntrack_tuple *tuple)
 124 {
 125         struct nf_conntrack_l3proto *l3proto;
 126         struct nf_conntrack_l4proto *l4proto;
 127         unsigned int protoff;
 128         u_int8_t protonum;
 129         int ret;
 130
 131         rcu_read_lock();
 132
 133         l3proto = __nf_ct_l3proto_find(l3num);
 134         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 135         if (ret != NF_ACCEPT) {
 136                 rcu_read_unlock();
 137                 return 0;
 138         }
 139
 140         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 141
 142         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 143                               l3proto, l4proto);
 144
 145         rcu_read_unlock();
 146         return ret;
 147 }
 148 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 149
 150 int
 151 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 152                    const struct nf_conntrack_tuple *orig,
 153                    const struct nf_conntrack_l3proto *l3proto,
 154                    const struct nf_conntrack_l4proto *l4proto)
 155 {
 156         NF_CT_TUPLE_U_BLANK(inverse);
 157
 158         inverse->src.l3num = orig->src.l3num;
 159         if (l3proto->invert_tuple(inverse, orig) == 0)
 160                 return 0;
 161
 162         inverse->dst.dir = !orig->dst.dir;
 163
 164         inverse->dst.protonum = orig->dst.protonum;
 165         return l4proto->invert_tuple(inverse, orig);
 166 }
 167 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 168
 169 static void
 170 clean_from_lists(struct nf_conn *ct)
 171 {
 172         pr_debug("clean_from_lists(%p)\n", ct);
 173         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 174         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 175
 176         /* Destroy all pending expectations */
 177         nf_ct_remove_expectations(ct);
 178 }
 179
 180 static void
 181 destroy_conntrack(struct nf_conntrack *nfct)
 182 {
 183         struct nf_conn *ct = (struct nf_conn *)nfct;
 184         struct nf_conntrack_l4proto *l4proto;
 185
 186         pr_debug("destroy_conntrack(%p)\n", ct);
 187         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 188         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 189
 190         nf_conntrack_event(IPCT_DESTROY, ct);
 191         set_bit(IPS_DYING_BIT, &ct->status);
 192
 193         /* To make sure we don't get any weird locking issues here:
 194          * destroy_conntrack() MUST NOT be called with a write lock
 195          * to nf_conntrack_lock!!! -HW */
 196         rcu_read_lock();
 197         l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num,
 198                                        ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
 199         if (l4proto && l4proto->destroy)
 200                 l4proto->destroy(ct);
 201
 202         nf_ct_ext_destroy(ct);
 203
 204         rcu_read_unlock();
 205
 206         spin_lock_bh(&nf_conntrack_lock);
 207         /* Expectations will have been removed in clean_from_lists,
 208          * except TFTP can create an expectation on the first packet,
 209          * before connection is in the list, so we need to clean here,
 210          * too. */
 211         nf_ct_remove_expectations(ct);
 212
 213         /* We overload first tuple to link into unconfirmed list. */
 214         if (!nf_ct_is_confirmed(ct)) {
 215                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 216                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 217         }
 218
 219         NF_CT_STAT_INC(delete);
 220         spin_unlock_bh(&nf_conntrack_lock);
 221
 222         if (ct->master)
 223                 nf_ct_put(ct->master);
 224
 225         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 226         nf_conntrack_free(ct);
 227 }
 228
 229 static void death_by_timeout(unsigned long ul_conntrack)
 230 {
 231         struct nf_conn *ct = (void *)ul_conntrack;
 232         struct nf_conn_help *help = nfct_help(ct);
 233         struct nf_conntrack_helper *helper;
 234
 235         if (help) {
 236                 rcu_read_lock();
 237                 helper = rcu_dereference(help->helper);
 238                 if (helper && helper->destroy)
 239                         helper->destroy(ct);
 240                 rcu_read_unlock();
 241         }
 242
 243         spin_lock_bh(&nf_conntrack_lock);
 244         /* Inside lock so preempt is disabled on module removal path.
 245          * Otherwise we can get spurious warnings. */
 246         NF_CT_STAT_INC(delete_list);
 247         clean_from_lists(ct);
 248         spin_unlock_bh(&nf_conntrack_lock);
 249         nf_ct_put(ct);
 250 }
 251
 252 struct nf_conntrack_tuple_hash *
 253 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple)
 254 {
 255         struct nf_conntrack_tuple_hash *h;
 256         struct hlist_node *n;
 257         unsigned int hash = hash_conntrack(tuple);
 258
 259         /* Disable BHs the entire time since we normally need to disable them
 260          * at least once for the stats anyway.
 261          */
 262         local_bh_disable();
 263         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 264                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 265                         NF_CT_STAT_INC(found);
 266                         local_bh_enable();
 267                         return h;
 268                 }
 269                 NF_CT_STAT_INC(searched);
 270         }
 271         local_bh_enable();
 272
 273         return NULL;
 274 }
 275 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 276
 277 /* Find a connection corresponding to a tuple. */
 278 struct nf_conntrack_tuple_hash *
 279 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
 280 {
 281         struct nf_conntrack_tuple_hash *h;
 282         struct nf_conn *ct;
 283
 284         rcu_read_lock();
 285         h = __nf_conntrack_find(tuple);
 286         if (h) {
 287                 ct = nf_ct_tuplehash_to_ctrack(h);
 288                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 289                         h = NULL;
 290         }
 291         rcu_read_unlock();
 292
 293         return h;
 294 }
 295 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 296
 297 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 298                                        unsigned int hash,
 299                                        unsigned int repl_hash)
 300 {
 301         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 302                            &nf_conntrack_hash[hash]);
 303         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 304                            &nf_conntrack_hash[repl_hash]);
 305 }
 306
 307 void nf_conntrack_hash_insert(struct nf_conn *ct)
 308 {
 309         unsigned int hash, repl_hash;
 310
 311         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 312         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 313
 314         spin_lock_bh(&nf_conntrack_lock);
 315         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 316         spin_unlock_bh(&nf_conntrack_lock);
 317 }
 318 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 319
 320 /* Confirm a connection given skb; places it in hash table */
 321 int
 322 __nf_conntrack_confirm(struct sk_buff *skb)
 323 {
 324         unsigned int hash, repl_hash;
 325         struct nf_conntrack_tuple_hash *h;
 326         struct nf_conn *ct;
 327         struct nf_conn_help *help;
 328         struct hlist_node *n;
 329         enum ip_conntrack_info ctinfo;
 330
 331         ct = nf_ct_get(skb, &ctinfo);
 332
 333         /* ipt_REJECT uses nf_conntrack_attach to attach related
 334            ICMP/TCP RST packets in other direction.  Actual packet
 335            which created connection will be IP_CT_NEW or for an
 336            expected connection, IP_CT_RELATED. */
 337         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 338                 return NF_ACCEPT;
 339
 340         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 341         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 342
 343         /* We're not in hash table, and we refuse to set up related
 344            connections for unconfirmed conns.  But packet copies and
 345            REJECT will give spurious warnings here. */
 346         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 347
 348         /* No external references means noone else could have
 349            confirmed us. */
 350         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 351         pr_debug("Confirming conntrack %p\n", ct);
 352
 353         spin_lock_bh(&nf_conntrack_lock);
 354
 355         /* See if there's one in the list already, including reverse:
 356            NAT could have grabbed it without realizing, since we're
 357            not in the hash.  If there is, we lost race. */
 358         hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode)
 359                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 360                                       &h->tuple))
 361                         goto out;
 362         hlist_for_each_entry(h, n, &nf_conntrack_hash[repl_hash], hnode)
 363                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 364                                       &h->tuple))
 365                         goto out;
 366
 367         /* Remove from unconfirmed list */
 368         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 369
 370         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 371         /* Timer relative to confirmation time, not original
 372            setting time, otherwise we'd get timer wrap in
 373            weird delay cases. */
 374         ct->timeout.expires += jiffies;
 375         add_timer(&ct->timeout);
 376         atomic_inc(&ct->ct_general.use);
 377         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 378         NF_CT_STAT_INC(insert);
 379         spin_unlock_bh(&nf_conntrack_lock);
 380         help = nfct_help(ct);
 381         if (help && help->helper)
 382                 nf_conntrack_event_cache(IPCT_HELPER, skb);
 383 #ifdef CONFIG_NF_NAT_NEEDED
 384         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 385             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 386                 nf_conntrack_event_cache(IPCT_NATINFO, skb);
 387 #endif
 388         nf_conntrack_event_cache(master_ct(ct) ?
 389                                  IPCT_RELATED : IPCT_NEW, skb);
 390         return NF_ACCEPT;
 391
 392 out:
 393         NF_CT_STAT_INC(insert_failed);
 394         spin_unlock_bh(&nf_conntrack_lock);
 395         return NF_DROP;
 396 }
 397 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 398
 399 /* Returns true if a connection correspondings to the tuple (required
 400    for NAT). */
 401 int
 402 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 403                          const struct nf_conn *ignored_conntrack)
 404 {
 405         struct nf_conntrack_tuple_hash *h;
 406         struct hlist_node *n;
 407         unsigned int hash = hash_conntrack(tuple);
 408
 409         /* Disable BHs the entire time since we need to disable them at
 410          * least once for the stats anyway.
 411          */
 412         rcu_read_lock_bh();
 413         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 414                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 415                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 416                         NF_CT_STAT_INC(found);
 417                         rcu_read_unlock_bh();
 418                         return 1;
 419                 }
 420                 NF_CT_STAT_INC(searched);
 421         }
 422         rcu_read_unlock_bh();
 423
 424         return 0;
 425 }
 426 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 427
 428 #define NF_CT_EVICTION_RANGE    8
 429
 430 /* There's a small race here where we may free a just-assured
 431    connection.  Too bad: we're in trouble anyway. */
 432 static noinline int early_drop(unsigned int hash)
 433 {
 434         /* Use oldest entry, which is roughly LRU */
 435         struct nf_conntrack_tuple_hash *h;
 436         struct nf_conn *ct = NULL, *tmp;
 437         struct hlist_node *n;
 438         unsigned int i, cnt = 0;
 439         int dropped = 0;
 440
 441         rcu_read_lock();
 442         for (i = 0; i < nf_conntrack_htable_size; i++) {
 443                 hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
 444                                          hnode) {
 445                         tmp = nf_ct_tuplehash_to_ctrack(h);
 446                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 447                                 ct = tmp;
 448                         cnt++;
 449                 }
 450
 451                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 452                         ct = NULL;
 453                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 454                         break;
 455                 hash = (hash + 1) % nf_conntrack_htable_size;
 456         }
 457         rcu_read_unlock();
 458
 459         if (!ct)
 460                 return dropped;
 461
 462         if (del_timer(&ct->timeout)) {
 463                 death_by_timeout((unsigned long)ct);
 464                 dropped = 1;
 465                 NF_CT_STAT_INC_ATOMIC(early_drop);
 466         }
 467         nf_ct_put(ct);
 468         return dropped;
 469 }
 470
 471 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 472                                    const struct nf_conntrack_tuple *repl)
 473 {
 474         struct nf_conn *ct = NULL;
 475
 476         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 477                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 478                 nf_conntrack_hash_rnd_initted = 1;
 479         }
 480
 481         /* We don't want any race condition at early drop stage */
 482         atomic_inc(&nf_conntrack_count);
 483
 484         if (nf_conntrack_max &&
 485             unlikely(atomic_read(&nf_conntrack_count) > nf_conntrack_max)) {
 486                 unsigned int hash = hash_conntrack(orig);
 487                 if (!early_drop(hash)) {
 488                         atomic_dec(&nf_conntrack_count);
 489                         if (net_ratelimit())
 490                                 printk(KERN_WARNING
 491                                        "nf_conntrack: table full, dropping"
 492                                        " packet.\n");
 493                         return ERR_PTR(-ENOMEM);
 494                 }
 495         }
 496
 497         ct = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC);
 498         if (ct == NULL) {
 499                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 500                 atomic_dec(&nf_conntrack_count);
 501                 return ERR_PTR(-ENOMEM);
 502         }
 503
 504         atomic_set(&ct->ct_general.use, 1);
 505         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 506         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 507         /* Don't set timer yet: wait for confirmation */
 508         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 509         INIT_RCU_HEAD(&ct->rcu);
 510
 511         return ct;
 512 }
 513 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 514
 515 static void nf_conntrack_free_rcu(struct rcu_head *head)
 516 {
 517         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 518
 519         nf_ct_ext_free(ct);
 520         kmem_cache_free(nf_conntrack_cachep, ct);
 521         atomic_dec(&nf_conntrack_count);
 522 }
 523
 524 void nf_conntrack_free(struct nf_conn *ct)
 525 {
 526         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 527 }
 528 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 529
 530 /* Allocate a new conntrack: we return -ENOMEM if classification
 531    failed due to stress.  Otherwise it really is unclassifiable. */
 532 static struct nf_conntrack_tuple_hash *
 533 init_conntrack(const struct nf_conntrack_tuple *tuple,
 534                struct nf_conntrack_l3proto *l3proto,
 535                struct nf_conntrack_l4proto *l4proto,
 536                struct sk_buff *skb,
 537                unsigned int dataoff)
 538 {
 539         struct nf_conn *ct;
 540         struct nf_conn_help *help;
 541         struct nf_conntrack_tuple repl_tuple;
 542         struct nf_conntrack_expect *exp;
 543
 544         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 545                 pr_debug("Can't invert tuple.\n");
 546                 return NULL;
 547         }
 548
 549         ct = nf_conntrack_alloc(tuple, &repl_tuple);
 550         if (ct == NULL || IS_ERR(ct)) {
 551                 pr_debug("Can't allocate conntrack.\n");
 552                 return (struct nf_conntrack_tuple_hash *)ct;
 553         }
 554
 555         if (!l4proto->new(ct, skb, dataoff)) {
 556                 nf_conntrack_free(ct);
 557                 pr_debug("init conntrack: can't track with proto module\n");
 558                 return NULL;
 559         }
 560
 561         spin_lock_bh(&nf_conntrack_lock);
 562         exp = nf_ct_find_expectation(tuple);
 563         if (exp) {
 564                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 565                          ct, exp);
 566                 /* Welcome, Mr. Bond.  We've been expecting you... */
 567                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 568                 ct->master = exp->master;
 569                 if (exp->helper) {
 570                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 571                         if (help)
 572                                 rcu_assign_pointer(help->helper, exp->helper);
 573                 }
 574
 575 #ifdef CONFIG_NF_CONNTRACK_MARK
 576                 ct->mark = exp->master->mark;
 577 #endif
 578 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 579                 ct->secmark = exp->master->secmark;
 580 #endif
 581                 nf_conntrack_get(&ct->master->ct_general);
 582                 NF_CT_STAT_INC(expect_new);
 583         } else {
 584                 struct nf_conntrack_helper *helper;
 585
 586                 helper = __nf_ct_helper_find(&repl_tuple);
 587                 if (helper) {
 588                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 589                         if (help)
 590                                 rcu_assign_pointer(help->helper, helper);
 591                 }
 592                 NF_CT_STAT_INC(new);
 593         }
 594
 595         /* Overload tuple linked list to put us in unconfirmed list. */
 596         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, &unconfirmed);
 597
 598         spin_unlock_bh(&nf_conntrack_lock);
 599
 600         if (exp) {
 601                 if (exp->expectfn)
 602                         exp->expectfn(ct, exp);
 603                 nf_ct_expect_put(exp);
 604         }
 605
 606         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 607 }
 608
 609 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 610 static inline struct nf_conn *
 611 resolve_normal_ct(struct sk_buff *skb,
 612                   unsigned int dataoff,
 613                   u_int16_t l3num,
 614                   u_int8_t protonum,
 615                   struct nf_conntrack_l3proto *l3proto,
 616                   struct nf_conntrack_l4proto *l4proto,
 617                   int *set_reply,
 618                   enum ip_conntrack_info *ctinfo)
 619 {
 620         struct nf_conntrack_tuple tuple;
 621         struct nf_conntrack_tuple_hash *h;
 622         struct nf_conn *ct;
 623
 624         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 625                              dataoff, l3num, protonum, &tuple, l3proto,
 626                              l4proto)) {
 627                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 628                 return NULL;
 629         }
 630
 631         /* look for tuple match */
 632         h = nf_conntrack_find_get(&tuple);
 633         if (!h) {
 634                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
 635                 if (!h)
 636                         return NULL;
 637                 if (IS_ERR(h))
 638                         return (void *)h;
 639         }
 640         ct = nf_ct_tuplehash_to_ctrack(h);
 641
 642         /* It exists; we have (non-exclusive) reference. */
 643         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 644                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 645                 /* Please set reply bit if this packet OK */
 646                 *set_reply = 1;
 647         } else {
 648                 /* Once we've had two way comms, always ESTABLISHED. */
 649                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 650                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 651                         *ctinfo = IP_CT_ESTABLISHED;
 652                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 653                         pr_debug("nf_conntrack_in: related packet for %p\n",
 654                                  ct);
 655                         *ctinfo = IP_CT_RELATED;
 656                 } else {
 657                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 658                         *ctinfo = IP_CT_NEW;
 659                 }
 660                 *set_reply = 0;
 661         }
 662         skb->nfct = &ct->ct_general;
 663         skb->nfctinfo = *ctinfo;
 664         return ct;
 665 }
 666
 667 unsigned int
 668 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff *skb)
 669 {
 670         struct nf_conn *ct;
 671         enum ip_conntrack_info ctinfo;
 672         struct nf_conntrack_l3proto *l3proto;
 673         struct nf_conntrack_l4proto *l4proto;
 674         unsigned int dataoff;
 675         u_int8_t protonum;
 676         int set_reply = 0;
 677         int ret;
 678
 679         /* Previously seen (loopback or untracked)?  Ignore. */
 680         if (skb->nfct) {
 681                 NF_CT_STAT_INC_ATOMIC(ignore);
 682                 return NF_ACCEPT;
 683         }
 684
 685         /* rcu_read_lock()ed by nf_hook_slow */
 686         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
 687         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 688                                    &dataoff, &protonum);
 689         if (ret <= 0) {
 690                 pr_debug("not prepared to track yet or error occured\n");
 691                 NF_CT_STAT_INC_ATOMIC(error);
 692                 NF_CT_STAT_INC_ATOMIC(invalid);
 693                 return -ret;
 694         }
 695
 696         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
 697
 698         /* It may be an special packet, error, unclean...
 699          * inverse of the return code tells to the netfilter
 700          * core what to do with the packet. */
 701         if (l4proto->error != NULL &&
 702             (ret = l4proto->error(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
 703                 NF_CT_STAT_INC_ATOMIC(error);
 704                 NF_CT_STAT_INC_ATOMIC(invalid);
 705                 return -ret;
 706         }
 707
 708         ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
 709                                &set_reply, &ctinfo);
 710         if (!ct) {
 711                 /* Not valid part of a connection */
 712                 NF_CT_STAT_INC_ATOMIC(invalid);
 713                 return NF_ACCEPT;
 714         }
 715
 716         if (IS_ERR(ct)) {
 717                 /* Too stressed to deal. */
 718                 NF_CT_STAT_INC_ATOMIC(drop);
 719                 return NF_DROP;
 720         }
 721
 722         NF_CT_ASSERT(skb->nfct);
 723
 724         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 725         if (ret < 0) {
 726                 /* Invalid: inverse of the return code tells
 727                  * the netfilter core what to do */
 728                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 729                 nf_conntrack_put(skb->nfct);
 730                 skb->nfct = NULL;
 731                 NF_CT_STAT_INC_ATOMIC(invalid);
 732                 return -ret;
 733         }
 734
 735         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 736                 nf_conntrack_event_cache(IPCT_STATUS, skb);
 737
 738         return ret;
 739 }
 740 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 741
 742 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 743                          const struct nf_conntrack_tuple *orig)
 744 {
 745         int ret;
 746
 747         rcu_read_lock();
 748         ret = nf_ct_invert_tuple(inverse, orig,
 749                                  __nf_ct_l3proto_find(orig->src.l3num),
 750                                  __nf_ct_l4proto_find(orig->src.l3num,
 751                                                       orig->dst.protonum));
 752         rcu_read_unlock();
 753         return ret;
 754 }
 755 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 756
 757 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 758    implicitly racy: see __nf_conntrack_confirm */
 759 void nf_conntrack_alter_reply(struct nf_conn *ct,
 760                               const struct nf_conntrack_tuple *newreply)
 761 {
 762         struct nf_conn_help *help = nfct_help(ct);
 763         struct nf_conntrack_helper *helper;
 764
 765         /* Should be unconfirmed, so not in hash table yet */
 766         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 767
 768         pr_debug("Altering reply tuple of %p to ", ct);
 769         NF_CT_DUMP_TUPLE(newreply);
 770
 771         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 772         if (ct->master || (help && help->expecting != 0))
 773                 return;
 774
 775         rcu_read_lock();
 776         helper = __nf_ct_helper_find(newreply);
 777         if (helper == NULL) {
 778                 if (help)
 779                         rcu_assign_pointer(help->helper, NULL);
 780                 goto out;
 781         }
 782
 783         if (help == NULL) {
 784                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 785                 if (help == NULL)
 786                         goto out;
 787         } else {
 788                 memset(&help->help, 0, sizeof(help->help));
 789         }
 790
 791         rcu_assign_pointer(help->helper, helper);
 792 out:
 793         rcu_read_unlock();
 794 }
 795 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 796
 797 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 798 void __nf_ct_refresh_acct(struct nf_conn *ct,
 799                           enum ip_conntrack_info ctinfo,
 800                           const struct sk_buff *skb,
 801                           unsigned long extra_jiffies,
 802                           int do_acct)
 803 {
 804         int event = 0;
 805
 806         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 807         NF_CT_ASSERT(skb);
 808
 809         spin_lock_bh(&nf_conntrack_lock);
 810
 811         /* Only update if this is not a fixed timeout */
 812         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 813                 goto acct;
 814
 815         /* If not in hash table, timer will not be active yet */
 816         if (!nf_ct_is_confirmed(ct)) {
 817                 ct->timeout.expires = extra_jiffies;
 818                 event = IPCT_REFRESH;
 819         } else {
 820                 unsigned long newtime = jiffies + extra_jiffies;
 821
 822                 /* Only update the timeout if the new timeout is at least
 823                    HZ jiffies from the old timeout. Need del_timer for race
 824                    avoidance (may already be dying). */
 825                 if (newtime - ct->timeout.expires >= HZ
 826                     && del_timer(&ct->timeout)) {
 827                         ct->timeout.expires = newtime;
 828                         add_timer(&ct->timeout);
 829                         event = IPCT_REFRESH;
 830                 }
 831         }
 832
 833 acct:
 834 #ifdef CONFIG_NF_CT_ACCT
 835         if (do_acct) {
 836                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
 837                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
 838                         skb->len - skb_network_offset(skb);
 839
 840                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
 841                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
 842                         event |= IPCT_COUNTER_FILLING;
 843         }
 844 #endif
 845
 846         spin_unlock_bh(&nf_conntrack_lock);
 847
 848         /* must be unlocked when calling event cache */
 849         if (event)
 850                 nf_conntrack_event_cache(event, skb);
 851 }
 852 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 853
 854 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 855
 856 #include <linux/netfilter/nfnetlink.h>
 857 #include <linux/netfilter/nfnetlink_conntrack.h>
 858 #include <linux/mutex.h>
 859
 860 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 861  * in ip_conntrack_core, since we don't want the protocols to autoload
 862  * or depend on ctnetlink */
 863 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 864                                const struct nf_conntrack_tuple *tuple)
 865 {
 866         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 867         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 868         return 0;
 869
 870 nla_put_failure:
 871         return -1;
 872 }
 873 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 874
 875 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 876         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 877         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 878 };
 879 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 880
 881 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 882                                struct nf_conntrack_tuple *t)
 883 {
 884         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 885                 return -EINVAL;
 886
 887         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 888         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 889
 890         return 0;
 891 }
 892 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 893 #endif
 894
 895 /* Used by ipt_REJECT and ip6t_REJECT. */
 896 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 897 {
 898         struct nf_conn *ct;
 899         enum ip_conntrack_info ctinfo;
 900
 901         /* This ICMP is in reverse direction to the packet which caused it */
 902         ct = nf_ct_get(skb, &ctinfo);
 903         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 904                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 905         else
 906                 ctinfo = IP_CT_RELATED;
 907
 908         /* Attach to new skbuff, and increment count */
 909         nskb->nfct = &ct->ct_general;
 910         nskb->nfctinfo = ctinfo;
 911         nf_conntrack_get(nskb->nfct);
 912 }
 913
 914 /* Bring out ya dead! */
 915 static struct nf_conn *
 916 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
 917                 void *data, unsigned int *bucket)
 918 {
 919         struct nf_conntrack_tuple_hash *h;
 920         struct nf_conn *ct;
 921         struct hlist_node *n;
 922
 923         spin_lock_bh(&nf_conntrack_lock);
 924         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 925                 hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) {
 926                         ct = nf_ct_tuplehash_to_ctrack(h);
 927                         if (iter(ct, data))
 928                                 goto found;
 929                 }
 930         }
 931         hlist_for_each_entry(h, n, &unconfirmed, hnode) {
 932                 ct = nf_ct_tuplehash_to_ctrack(h);
 933                 if (iter(ct, data))
 934                         set_bit(IPS_DYING_BIT, &ct->status);
 935         }
 936         spin_unlock_bh(&nf_conntrack_lock);
 937         return NULL;
 938 found:
 939         atomic_inc(&ct->ct_general.use);
 940         spin_unlock_bh(&nf_conntrack_lock);
 941         return ct;
 942 }
 943
 944 void
 945 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
 946 {
 947         struct nf_conn *ct;
 948         unsigned int bucket = 0;
 949
 950         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
 951                 /* Time to push up daises... */
 952                 if (del_timer(&ct->timeout))
 953                         death_by_timeout((unsigned long)ct);
 954                 /* ... else the timer will get him soon. */
 955
 956                 nf_ct_put(ct);
 957         }
 958 }
 959 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 960
 961 static int kill_all(struct nf_conn *i, void *data)
 962 {
 963         return 1;
 964 }
 965
 966 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 967 {
 968         if (vmalloced)
 969                 vfree(hash);
 970         else
 971                 free_pages((unsigned long)hash,
 972                            get_order(sizeof(struct hlist_head) * size));
 973 }
 974 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
 975
 976 void nf_conntrack_flush(void)
 977 {
 978         nf_ct_iterate_cleanup(kill_all, NULL);
 979 }
 980 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
 981
 982 /* Mishearing the voices in his head, our hero wonders how he's
 983    supposed to kill the mall. */
 984 void nf_conntrack_cleanup(void)
 985 {
 986         rcu_assign_pointer(ip_ct_attach, NULL);
 987
 988         /* This makes sure all current packets have passed through
 989            netfilter framework.  Roll on, two-stage module
 990            delete... */
 991         synchronize_net();
 992
 993         nf_ct_event_cache_flush();
 994  i_see_dead_people:
 995         nf_conntrack_flush();
 996         if (atomic_read(&nf_conntrack_count) != 0) {
 997                 schedule();
 998                 goto i_see_dead_people;
 999         }
1000         /* wait until all references to nf_conntrack_untracked are dropped */
1001         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1002                 schedule();
1003
1004         rcu_assign_pointer(nf_ct_destroy, NULL);
1005
1006         kmem_cache_destroy(nf_conntrack_cachep);
1007         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1008                              nf_conntrack_htable_size);
1009
1010         nf_conntrack_proto_fini();
1011         nf_conntrack_helper_fini();
1012         nf_conntrack_expect_fini();
1013 }
1014
1015 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1016 {
1017         struct hlist_head *hash;
1018         unsigned int size, i;
1019
1020         *vmalloced = 0;
1021
1022         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1023         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1024                                        get_order(sizeof(struct hlist_head)
1025                                                  * size));
1026         if (!hash) {
1027                 *vmalloced = 1;
1028                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1029                 hash = vmalloc(sizeof(struct hlist_head) * size);
1030         }
1031
1032         if (hash)
1033                 for (i = 0; i < size; i++)
1034                         INIT_HLIST_HEAD(&hash[i]);
1035
1036         return hash;
1037 }
1038 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1039
1040 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1041 {
1042         int i, bucket, vmalloced, old_vmalloced;
1043         unsigned int hashsize, old_size;
1044         int rnd;
1045         struct hlist_head *hash, *old_hash;
1046         struct nf_conntrack_tuple_hash *h;
1047
1048         /* On boot, we can set this without any fancy locking. */
1049         if (!nf_conntrack_htable_size)
1050                 return param_set_uint(val, kp);
1051
1052         hashsize = simple_strtoul(val, NULL, 0);
1053         if (!hashsize)
1054                 return -EINVAL;
1055
1056         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1057         if (!hash)
1058                 return -ENOMEM;
1059
1060         /* We have to rehahs for the new table anyway, so we also can
1061          * use a newrandom seed */
1062         get_random_bytes(&rnd, 4);
1063
1064         /* Lookups in the old hash might happen in parallel, which means we
1065          * might get false negatives during connection lookup. New connections
1066          * created because of a false negative won't make it into the hash
1067          * though since that required taking the lock.
1068          */
1069         spin_lock_bh(&nf_conntrack_lock);
1070         for (i = 0; i < nf_conntrack_htable_size; i++) {
1071                 while (!hlist_empty(&nf_conntrack_hash[i])) {
1072                         h = hlist_entry(nf_conntrack_hash[i].first,
1073                                         struct nf_conntrack_tuple_hash, hnode);
1074                         hlist_del_rcu(&h->hnode);
1075                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1076                         hlist_add_head(&h->hnode, &hash[bucket]);
1077                 }
1078         }
1079         old_size = nf_conntrack_htable_size;
1080         old_vmalloced = nf_conntrack_vmalloc;
1081         old_hash = nf_conntrack_hash;
1082
1083         nf_conntrack_htable_size = hashsize;
1084         nf_conntrack_vmalloc = vmalloced;
1085         nf_conntrack_hash = hash;
1086         nf_conntrack_hash_rnd = rnd;
1087         spin_unlock_bh(&nf_conntrack_lock);
1088
1089         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1090         return 0;
1091 }
1092 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1093
1094 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1095                   &nf_conntrack_htable_size, 0600);
1096
1097 int __init nf_conntrack_init(void)
1098 {
1099         int max_factor = 8;
1100         int ret;
1101
1102         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1103          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1104         if (!nf_conntrack_htable_size) {
1105                 nf_conntrack_htable_size
1106                         = (((num_physpages << PAGE_SHIFT) / 16384)
1107                            / sizeof(struct hlist_head));
1108                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1109                         nf_conntrack_htable_size = 16384;
1110                 if (nf_conntrack_htable_size < 32)
1111                         nf_conntrack_htable_size = 32;
1112
1113                 /* Use a max. factor of four by default to get the same max as
1114                  * with the old struct list_heads. When a table size is given
1115                  * we use the old value of 8 to avoid reducing the max.
1116                  * entries. */
1117                 max_factor = 4;
1118         }
1119         nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1120                                                   &nf_conntrack_vmalloc);
1121         if (!nf_conntrack_hash) {
1122                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1123                 goto err_out;
1124         }
1125
1126         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1127
1128         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1129                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1130                nf_conntrack_max);
1131
1132         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1133                                                 sizeof(struct nf_conn),
1134                                                 0, 0, NULL);
1135         if (!nf_conntrack_cachep) {
1136                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1137                 goto err_free_hash;
1138         }
1139
1140         ret = nf_conntrack_proto_init();
1141         if (ret < 0)
1142                 goto err_free_conntrack_slab;
1143
1144         ret = nf_conntrack_expect_init();
1145         if (ret < 0)
1146                 goto out_fini_proto;
1147
1148         ret = nf_conntrack_helper_init();
1149         if (ret < 0)
1150                 goto out_fini_expect;
1151
1152         /* For use by REJECT target */
1153         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1154         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1155
1156         /* Set up fake conntrack:
1157             - to never be deleted, not in any hashes */
1158         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1159         /*  - and look it like as a confirmed connection */
1160         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1161
1162         return ret;
1163
1164 out_fini_expect:
1165         nf_conntrack_expect_fini();
1166 out_fini_proto:
1167         nf_conntrack_proto_fini();
1168 err_free_conntrack_slab:
1169         kmem_cache_destroy(nf_conntrack_cachep);
1170 err_free_hash:
1171         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1172                              nf_conntrack_htable_size);
1173 err_out:
1174         return -ENOMEM;
1175 }