SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 260                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 261                         NF_CT_STAT_INC(found);
 262                         return h;
 263                 }
 264                 NF_CT_STAT_INC(searched);
 265         }
 266
 267         return NULL;
 268 }
 269 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 270
 271 /* Find a connection corresponding to a tuple. */
 272 struct nf_conntrack_tuple_hash *
 273 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
 274 {
 275         struct nf_conntrack_tuple_hash *h;
 276         struct nf_conn *ct;
 277
 278         rcu_read_lock();
 279         h = __nf_conntrack_find(tuple);
 280         if (h) {
 281                 ct = nf_ct_tuplehash_to_ctrack(h);
 282                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 283                         h = NULL;
 284         }
 285         rcu_read_unlock();
 286
 287         return h;
 288 }
 289 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 290
 291 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 292                                        unsigned int hash,
 293                                        unsigned int repl_hash)
 294 {
 295         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 296                            &nf_conntrack_hash[hash]);
 297         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 298                            &nf_conntrack_hash[repl_hash]);
 299 }
 300
 301 void nf_conntrack_hash_insert(struct nf_conn *ct)
 302 {
 303         unsigned int hash, repl_hash;
 304
 305         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 306         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 307
 308         spin_lock_bh(&nf_conntrack_lock);
 309         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 310         spin_unlock_bh(&nf_conntrack_lock);
 311 }
 312 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 313
 314 /* Confirm a connection given skb; places it in hash table */
 315 int
 316 __nf_conntrack_confirm(struct sk_buff *skb)
 317 {
 318         unsigned int hash, repl_hash;
 319         struct nf_conntrack_tuple_hash *h;
 320         struct nf_conn *ct;
 321         struct nf_conn_help *help;
 322         struct hlist_node *n;
 323         enum ip_conntrack_info ctinfo;
 324
 325         ct = nf_ct_get(skb, &ctinfo);
 326
 327         /* ipt_REJECT uses nf_conntrack_attach to attach related
 328            ICMP/TCP RST packets in other direction.  Actual packet
 329            which created connection will be IP_CT_NEW or for an
 330            expected connection, IP_CT_RELATED. */
 331         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 332                 return NF_ACCEPT;
 333
 334         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 335         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 336
 337         /* We're not in hash table, and we refuse to set up related
 338            connections for unconfirmed conns.  But packet copies and
 339            REJECT will give spurious warnings here. */
 340         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 341
 342         /* No external references means noone else could have
 343            confirmed us. */
 344         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 345         pr_debug("Confirming conntrack %p\n", ct);
 346
 347         spin_lock_bh(&nf_conntrack_lock);
 348
 349         /* See if there's one in the list already, including reverse:
 350            NAT could have grabbed it without realizing, since we're
 351            not in the hash.  If there is, we lost race. */
 352         hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode)
 353                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 354                                       &h->tuple))
 355                         goto out;
 356         hlist_for_each_entry(h, n, &nf_conntrack_hash[repl_hash], hnode)
 357                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 358                                       &h->tuple))
 359                         goto out;
 360
 361         /* Remove from unconfirmed list */
 362         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 363
 364         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 365         /* Timer relative to confirmation time, not original
 366            setting time, otherwise we'd get timer wrap in
 367            weird delay cases. */
 368         ct->timeout.expires += jiffies;
 369         add_timer(&ct->timeout);
 370         atomic_inc(&ct->ct_general.use);
 371         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 372         NF_CT_STAT_INC(insert);
 373         spin_unlock_bh(&nf_conntrack_lock);
 374         help = nfct_help(ct);
 375         if (help && help->helper)
 376                 nf_conntrack_event_cache(IPCT_HELPER, skb);
 377 #ifdef CONFIG_NF_NAT_NEEDED
 378         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 379             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 380                 nf_conntrack_event_cache(IPCT_NATINFO, skb);
 381 #endif
 382         nf_conntrack_event_cache(master_ct(ct) ?
 383                                  IPCT_RELATED : IPCT_NEW, skb);
 384         return NF_ACCEPT;
 385
 386 out:
 387         NF_CT_STAT_INC(insert_failed);
 388         spin_unlock_bh(&nf_conntrack_lock);
 389         return NF_DROP;
 390 }
 391 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 392
 393 /* Returns true if a connection correspondings to the tuple (required
 394    for NAT). */
 395 int
 396 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 397                          const struct nf_conn *ignored_conntrack)
 398 {
 399         struct nf_conntrack_tuple_hash *h;
 400         struct hlist_node *n;
 401         unsigned int hash = hash_conntrack(tuple);
 402
 403         rcu_read_lock();
 404         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 405                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 406                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 407                         NF_CT_STAT_INC(found);
 408                         rcu_read_unlock();
 409                         return 1;
 410                 }
 411                 NF_CT_STAT_INC(searched);
 412         }
 413         rcu_read_unlock();
 414
 415         return 0;
 416 }
 417 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 418
 419 #define NF_CT_EVICTION_RANGE    8
 420
 421 /* There's a small race here where we may free a just-assured
 422    connection.  Too bad: we're in trouble anyway. */
 423 static int early_drop(unsigned int hash)
 424 {
 425         /* Use oldest entry, which is roughly LRU */
 426         struct nf_conntrack_tuple_hash *h;
 427         struct nf_conn *ct = NULL, *tmp;
 428         struct hlist_node *n;
 429         unsigned int i, cnt = 0;
 430         int dropped = 0;
 431
 432         rcu_read_lock();
 433         for (i = 0; i < nf_conntrack_htable_size; i++) {
 434                 hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
 435                                          hnode) {
 436                         tmp = nf_ct_tuplehash_to_ctrack(h);
 437                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 438                                 ct = tmp;
 439                         cnt++;
 440                 }
 441
 442                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 443                         ct = NULL;
 444                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 445                         break;
 446                 hash = (hash + 1) % nf_conntrack_htable_size;
 447         }
 448         rcu_read_unlock();
 449
 450         if (!ct)
 451                 return dropped;
 452
 453         if (del_timer(&ct->timeout)) {
 454                 death_by_timeout((unsigned long)ct);
 455                 dropped = 1;
 456                 NF_CT_STAT_INC_ATOMIC(early_drop);
 457         }
 458         nf_ct_put(ct);
 459         return dropped;
 460 }
 461
 462 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 463                                    const struct nf_conntrack_tuple *repl)
 464 {
 465         struct nf_conn *conntrack = NULL;
 466
 467         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 468                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 469                 nf_conntrack_hash_rnd_initted = 1;
 470         }
 471
 472         /* We don't want any race condition at early drop stage */
 473         atomic_inc(&nf_conntrack_count);
 474
 475         if (nf_conntrack_max
 476             && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
 477                 unsigned int hash = hash_conntrack(orig);
 478                 if (!early_drop(hash)) {
 479                         atomic_dec(&nf_conntrack_count);
 480                         if (net_ratelimit())
 481                                 printk(KERN_WARNING
 482                                        "nf_conntrack: table full, dropping"
 483                                        " packet.\n");
 484                         return ERR_PTR(-ENOMEM);
 485                 }
 486         }
 487
 488         conntrack = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC);
 489         if (conntrack == NULL) {
 490                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 491                 atomic_dec(&nf_conntrack_count);
 492                 return ERR_PTR(-ENOMEM);
 493         }
 494
 495         atomic_set(&conntrack->ct_general.use, 1);
 496         conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 497         conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 498         /* Don't set timer yet: wait for confirmation */
 499         setup_timer(&conntrack->timeout, death_by_timeout,
 500                     (unsigned long)conntrack);
 501         INIT_RCU_HEAD(&conntrack->rcu);
 502
 503         return conntrack;
 504 }
 505 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 506
 507 static void nf_conntrack_free_rcu(struct rcu_head *head)
 508 {
 509         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 510
 511         nf_ct_ext_free(ct);
 512         kmem_cache_free(nf_conntrack_cachep, ct);
 513         atomic_dec(&nf_conntrack_count);
 514 }
 515
 516 void nf_conntrack_free(struct nf_conn *conntrack)
 517 {
 518         call_rcu(&conntrack->rcu, nf_conntrack_free_rcu);
 519 }
 520 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 521
 522 /* Allocate a new conntrack: we return -ENOMEM if classification
 523    failed due to stress.  Otherwise it really is unclassifiable. */
 524 static struct nf_conntrack_tuple_hash *
 525 init_conntrack(const struct nf_conntrack_tuple *tuple,
 526                struct nf_conntrack_l3proto *l3proto,
 527                struct nf_conntrack_l4proto *l4proto,
 528                struct sk_buff *skb,
 529                unsigned int dataoff)
 530 {
 531         struct nf_conn *conntrack;
 532         struct nf_conn_help *help;
 533         struct nf_conntrack_tuple repl_tuple;
 534         struct nf_conntrack_expect *exp;
 535
 536         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 537                 pr_debug("Can't invert tuple.\n");
 538                 return NULL;
 539         }
 540
 541         conntrack = nf_conntrack_alloc(tuple, &repl_tuple);
 542         if (conntrack == NULL || IS_ERR(conntrack)) {
 543                 pr_debug("Can't allocate conntrack.\n");
 544                 return (struct nf_conntrack_tuple_hash *)conntrack;
 545         }
 546
 547         if (!l4proto->new(conntrack, skb, dataoff)) {
 548                 nf_conntrack_free(conntrack);
 549                 pr_debug("init conntrack: can't track with proto module\n");
 550                 return NULL;
 551         }
 552
 553         spin_lock_bh(&nf_conntrack_lock);
 554         exp = nf_ct_find_expectation(tuple);
 555         if (exp) {
 556                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 557                          conntrack, exp);
 558                 /* Welcome, Mr. Bond.  We've been expecting you... */
 559                 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
 560                 conntrack->master = exp->master;
 561                 if (exp->helper) {
 562                         help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
 563                         if (help)
 564                                 rcu_assign_pointer(help->helper, exp->helper);
 565                 }
 566
 567 #ifdef CONFIG_NF_CONNTRACK_MARK
 568                 conntrack->mark = exp->master->mark;
 569 #endif
 570 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 571                 conntrack->secmark = exp->master->secmark;
 572 #endif
 573                 nf_conntrack_get(&conntrack->master->ct_general);
 574                 NF_CT_STAT_INC(expect_new);
 575         } else {
 576                 struct nf_conntrack_helper *helper;
 577
 578                 helper = __nf_ct_helper_find(&repl_tuple);
 579                 if (helper) {
 580                         help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
 581                         if (help)
 582                                 rcu_assign_pointer(help->helper, helper);
 583                 }
 584                 NF_CT_STAT_INC(new);
 585         }
 586
 587         /* Overload tuple linked list to put us in unconfirmed list. */
 588         hlist_add_head(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 589                        &unconfirmed);
 590
 591         spin_unlock_bh(&nf_conntrack_lock);
 592
 593         if (exp) {
 594                 if (exp->expectfn)
 595                         exp->expectfn(conntrack, exp);
 596                 nf_ct_expect_put(exp);
 597         }
 598
 599         return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
 600 }
 601
 602 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 603 static inline struct nf_conn *
 604 resolve_normal_ct(struct sk_buff *skb,
 605                   unsigned int dataoff,
 606                   u_int16_t l3num,
 607                   u_int8_t protonum,
 608                   struct nf_conntrack_l3proto *l3proto,
 609                   struct nf_conntrack_l4proto *l4proto,
 610                   int *set_reply,
 611                   enum ip_conntrack_info *ctinfo)
 612 {
 613         struct nf_conntrack_tuple tuple;
 614         struct nf_conntrack_tuple_hash *h;
 615         struct nf_conn *ct;
 616
 617         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 618                              dataoff, l3num, protonum, &tuple, l3proto,
 619                              l4proto)) {
 620                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 621                 return NULL;
 622         }
 623
 624         /* look for tuple match */
 625         h = nf_conntrack_find_get(&tuple);
 626         if (!h) {
 627                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
 628                 if (!h)
 629                         return NULL;
 630                 if (IS_ERR(h))
 631                         return (void *)h;
 632         }
 633         ct = nf_ct_tuplehash_to_ctrack(h);
 634
 635         /* It exists; we have (non-exclusive) reference. */
 636         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 637                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 638                 /* Please set reply bit if this packet OK */
 639                 *set_reply = 1;
 640         } else {
 641                 /* Once we've had two way comms, always ESTABLISHED. */
 642                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 643                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 644                         *ctinfo = IP_CT_ESTABLISHED;
 645                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 646                         pr_debug("nf_conntrack_in: related packet for %p\n",
 647                                  ct);
 648                         *ctinfo = IP_CT_RELATED;
 649                 } else {
 650                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 651                         *ctinfo = IP_CT_NEW;
 652                 }
 653                 *set_reply = 0;
 654         }
 655         skb->nfct = &ct->ct_general;
 656         skb->nfctinfo = *ctinfo;
 657         return ct;
 658 }
 659
 660 unsigned int
 661 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff *skb)
 662 {
 663         struct nf_conn *ct;
 664         enum ip_conntrack_info ctinfo;
 665         struct nf_conntrack_l3proto *l3proto;
 666         struct nf_conntrack_l4proto *l4proto;
 667         unsigned int dataoff;
 668         u_int8_t protonum;
 669         int set_reply = 0;
 670         int ret;
 671
 672         /* Previously seen (loopback or untracked)?  Ignore. */
 673         if (skb->nfct) {
 674                 NF_CT_STAT_INC_ATOMIC(ignore);
 675                 return NF_ACCEPT;
 676         }
 677
 678         /* rcu_read_lock()ed by nf_hook_slow */
 679         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
 680         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 681                                    &dataoff, &protonum);
 682         if (ret <= 0) {
 683                 pr_debug("not prepared to track yet or error occured\n");
 684                 NF_CT_STAT_INC_ATOMIC(error);
 685                 NF_CT_STAT_INC_ATOMIC(invalid);
 686                 return -ret;
 687         }
 688
 689         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
 690
 691         /* It may be an special packet, error, unclean...
 692          * inverse of the return code tells to the netfilter
 693          * core what to do with the packet. */
 694         if (l4proto->error != NULL &&
 695             (ret = l4proto->error(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
 696                 NF_CT_STAT_INC_ATOMIC(error);
 697                 NF_CT_STAT_INC_ATOMIC(invalid);
 698                 return -ret;
 699         }
 700
 701         ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
 702                                &set_reply, &ctinfo);
 703         if (!ct) {
 704                 /* Not valid part of a connection */
 705                 NF_CT_STAT_INC_ATOMIC(invalid);
 706                 return NF_ACCEPT;
 707         }
 708
 709         if (IS_ERR(ct)) {
 710                 /* Too stressed to deal. */
 711                 NF_CT_STAT_INC_ATOMIC(drop);
 712                 return NF_DROP;
 713         }
 714
 715         NF_CT_ASSERT(skb->nfct);
 716
 717         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 718         if (ret < 0) {
 719                 /* Invalid: inverse of the return code tells
 720                  * the netfilter core what to do */
 721                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 722                 nf_conntrack_put(skb->nfct);
 723                 skb->nfct = NULL;
 724                 NF_CT_STAT_INC_ATOMIC(invalid);
 725                 return -ret;
 726         }
 727
 728         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 729                 nf_conntrack_event_cache(IPCT_STATUS, skb);
 730
 731         return ret;
 732 }
 733 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 734
 735 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 736                          const struct nf_conntrack_tuple *orig)
 737 {
 738         int ret;
 739
 740         rcu_read_lock();
 741         ret = nf_ct_invert_tuple(inverse, orig,
 742                                  __nf_ct_l3proto_find(orig->src.l3num),
 743                                  __nf_ct_l4proto_find(orig->src.l3num,
 744                                                       orig->dst.protonum));
 745         rcu_read_unlock();
 746         return ret;
 747 }
 748 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 749
 750 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 751    implicitly racy: see __nf_conntrack_confirm */
 752 void nf_conntrack_alter_reply(struct nf_conn *ct,
 753                               const struct nf_conntrack_tuple *newreply)
 754 {
 755         struct nf_conn_help *help = nfct_help(ct);
 756         struct nf_conntrack_helper *helper;
 757
 758         /* Should be unconfirmed, so not in hash table yet */
 759         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 760
 761         pr_debug("Altering reply tuple of %p to ", ct);
 762         NF_CT_DUMP_TUPLE(newreply);
 763
 764         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 765         if (ct->master || (help && help->expecting != 0))
 766                 return;
 767
 768         rcu_read_lock();
 769         helper = __nf_ct_helper_find(newreply);
 770         if (helper == NULL) {
 771                 if (help)
 772                         rcu_assign_pointer(help->helper, NULL);
 773                 goto out;
 774         }
 775
 776         if (help == NULL) {
 777                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 778                 if (help == NULL)
 779                         goto out;
 780         } else {
 781                 memset(&help->help, 0, sizeof(help->help));
 782         }
 783
 784         rcu_assign_pointer(help->helper, helper);
 785 out:
 786         rcu_read_unlock();
 787 }
 788 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 789
 790 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 791 void __nf_ct_refresh_acct(struct nf_conn *ct,
 792                           enum ip_conntrack_info ctinfo,
 793                           const struct sk_buff *skb,
 794                           unsigned long extra_jiffies,
 795                           int do_acct)
 796 {
 797         int event = 0;
 798
 799         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 800         NF_CT_ASSERT(skb);
 801
 802         spin_lock_bh(&nf_conntrack_lock);
 803
 804         /* Only update if this is not a fixed timeout */
 805         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 806                 goto acct;
 807
 808         /* If not in hash table, timer will not be active yet */
 809         if (!nf_ct_is_confirmed(ct)) {
 810                 ct->timeout.expires = extra_jiffies;
 811                 event = IPCT_REFRESH;
 812         } else {
 813                 unsigned long newtime = jiffies + extra_jiffies;
 814
 815                 /* Only update the timeout if the new timeout is at least
 816                    HZ jiffies from the old timeout. Need del_timer for race
 817                    avoidance (may already be dying). */
 818                 if (newtime - ct->timeout.expires >= HZ
 819                     && del_timer(&ct->timeout)) {
 820                         ct->timeout.expires = newtime;
 821                         add_timer(&ct->timeout);
 822                         event = IPCT_REFRESH;
 823                 }
 824         }
 825
 826 acct:
 827 #ifdef CONFIG_NF_CT_ACCT
 828         if (do_acct) {
 829                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
 830                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
 831                         skb->len - skb_network_offset(skb);
 832
 833                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
 834                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
 835                         event |= IPCT_COUNTER_FILLING;
 836         }
 837 #endif
 838
 839         spin_unlock_bh(&nf_conntrack_lock);
 840
 841         /* must be unlocked when calling event cache */
 842         if (event)
 843                 nf_conntrack_event_cache(event, skb);
 844 }
 845 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 846
 847 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 848
 849 #include <linux/netfilter/nfnetlink.h>
 850 #include <linux/netfilter/nfnetlink_conntrack.h>
 851 #include <linux/mutex.h>
 852
 853 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 854  * in ip_conntrack_core, since we don't want the protocols to autoload
 855  * or depend on ctnetlink */
 856 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 857                                const struct nf_conntrack_tuple *tuple)
 858 {
 859         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 860         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 861         return 0;
 862
 863 nla_put_failure:
 864         return -1;
 865 }
 866 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 867
 868 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 869         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 870         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 871 };
 872 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 873
 874 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 875                                struct nf_conntrack_tuple *t)
 876 {
 877         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 878                 return -EINVAL;
 879
 880         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 881         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 882
 883         return 0;
 884 }
 885 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 886 #endif
 887
 888 /* Used by ipt_REJECT and ip6t_REJECT. */
 889 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 890 {
 891         struct nf_conn *ct;
 892         enum ip_conntrack_info ctinfo;
 893
 894         /* This ICMP is in reverse direction to the packet which caused it */
 895         ct = nf_ct_get(skb, &ctinfo);
 896         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 897                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 898         else
 899                 ctinfo = IP_CT_RELATED;
 900
 901         /* Attach to new skbuff, and increment count */
 902         nskb->nfct = &ct->ct_general;
 903         nskb->nfctinfo = ctinfo;
 904         nf_conntrack_get(nskb->nfct);
 905 }
 906
 907 static inline int
 908 do_iter(const struct nf_conntrack_tuple_hash *i,
 909         int (*iter)(struct nf_conn *i, void *data),
 910         void *data)
 911 {
 912         return iter(nf_ct_tuplehash_to_ctrack(i), data);
 913 }
 914
 915 /* Bring out ya dead! */
 916 static struct nf_conn *
 917 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
 918                 void *data, unsigned int *bucket)
 919 {
 920         struct nf_conntrack_tuple_hash *h;
 921         struct nf_conn *ct;
 922         struct hlist_node *n;
 923
 924         spin_lock_bh(&nf_conntrack_lock);
 925         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 926                 hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) {
 927                         ct = nf_ct_tuplehash_to_ctrack(h);
 928                         if (iter(ct, data))
 929                                 goto found;
 930                 }
 931         }
 932         hlist_for_each_entry(h, n, &unconfirmed, hnode) {
 933                 ct = nf_ct_tuplehash_to_ctrack(h);
 934                 if (iter(ct, data))
 935                         set_bit(IPS_DYING_BIT, &ct->status);
 936         }
 937         spin_unlock_bh(&nf_conntrack_lock);
 938         return NULL;
 939 found:
 940         atomic_inc(&ct->ct_general.use);
 941         spin_unlock_bh(&nf_conntrack_lock);
 942         return ct;
 943 }
 944
 945 void
 946 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
 947 {
 948         struct nf_conn *ct;
 949         unsigned int bucket = 0;
 950
 951         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
 952                 /* Time to push up daises... */
 953                 if (del_timer(&ct->timeout))
 954                         death_by_timeout((unsigned long)ct);
 955                 /* ... else the timer will get him soon. */
 956
 957                 nf_ct_put(ct);
 958         }
 959 }
 960 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 961
 962 static int kill_all(struct nf_conn *i, void *data)
 963 {
 964         return 1;
 965 }
 966
 967 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 968 {
 969         if (vmalloced)
 970                 vfree(hash);
 971         else
 972                 free_pages((unsigned long)hash,
 973                            get_order(sizeof(struct hlist_head) * size));
 974 }
 975 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
 976
 977 void nf_conntrack_flush(void)
 978 {
 979         nf_ct_iterate_cleanup(kill_all, NULL);
 980 }
 981 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
 982
 983 /* Mishearing the voices in his head, our hero wonders how he's
 984    supposed to kill the mall. */
 985 void nf_conntrack_cleanup(void)
 986 {
 987         rcu_assign_pointer(ip_ct_attach, NULL);
 988
 989         /* This makes sure all current packets have passed through
 990            netfilter framework.  Roll on, two-stage module
 991            delete... */
 992         synchronize_net();
 993
 994         nf_ct_event_cache_flush();
 995  i_see_dead_people:
 996         nf_conntrack_flush();
 997         if (atomic_read(&nf_conntrack_count) != 0) {
 998                 schedule();
 999                 goto i_see_dead_people;
1000         }
1001         /* wait until all references to nf_conntrack_untracked are dropped */
1002         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1003                 schedule();
1004
1005         rcu_assign_pointer(nf_ct_destroy, NULL);
1006
1007         kmem_cache_destroy(nf_conntrack_cachep);
1008         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1009                              nf_conntrack_htable_size);
1010
1011         nf_conntrack_proto_fini();
1012         nf_conntrack_helper_fini();
1013         nf_conntrack_expect_fini();
1014 }
1015
1016 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1017 {
1018         struct hlist_head *hash;
1019         unsigned int size, i;
1020
1021         *vmalloced = 0;
1022
1023         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1024         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1025                                        get_order(sizeof(struct hlist_head)
1026                                                  * size));
1027         if (!hash) {
1028                 *vmalloced = 1;
1029                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1030                 hash = vmalloc(sizeof(struct hlist_head) * size);
1031         }
1032
1033         if (hash)
1034                 for (i = 0; i < size; i++)
1035                         INIT_HLIST_HEAD(&hash[i]);
1036
1037         return hash;
1038 }
1039 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1040
1041 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1042 {
1043         int i, bucket, vmalloced, old_vmalloced;
1044         unsigned int hashsize, old_size;
1045         int rnd;
1046         struct hlist_head *hash, *old_hash;
1047         struct nf_conntrack_tuple_hash *h;
1048
1049         /* On boot, we can set this without any fancy locking. */
1050         if (!nf_conntrack_htable_size)
1051                 return param_set_uint(val, kp);
1052
1053         hashsize = simple_strtoul(val, NULL, 0);
1054         if (!hashsize)
1055                 return -EINVAL;
1056
1057         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1058         if (!hash)
1059                 return -ENOMEM;
1060
1061         /* We have to rehahs for the new table anyway, so we also can
1062          * use a newrandom seed */
1063         get_random_bytes(&rnd, 4);
1064
1065         /* Lookups in the old hash might happen in parallel, which means we
1066          * might get false negatives during connection lookup. New connections
1067          * created because of a false negative won't make it into the hash
1068          * though since that required taking the lock.
1069          */
1070         spin_lock_bh(&nf_conntrack_lock);
1071         for (i = 0; i < nf_conntrack_htable_size; i++) {
1072                 while (!hlist_empty(&nf_conntrack_hash[i])) {
1073                         h = hlist_entry(nf_conntrack_hash[i].first,
1074                                         struct nf_conntrack_tuple_hash, hnode);
1075                         hlist_del_rcu(&h->hnode);
1076                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1077                         hlist_add_head(&h->hnode, &hash[bucket]);
1078                 }
1079         }
1080         old_size = nf_conntrack_htable_size;
1081         old_vmalloced = nf_conntrack_vmalloc;
1082         old_hash = nf_conntrack_hash;
1083
1084         nf_conntrack_htable_size = hashsize;
1085         nf_conntrack_vmalloc = vmalloced;
1086         nf_conntrack_hash = hash;
1087         nf_conntrack_hash_rnd = rnd;
1088         spin_unlock_bh(&nf_conntrack_lock);
1089
1090         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1091         return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1094
1095 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1096                   &nf_conntrack_htable_size, 0600);
1097
1098 int __init nf_conntrack_init(void)
1099 {
1100         int max_factor = 8;
1101         int ret;
1102
1103         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1104          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1105         if (!nf_conntrack_htable_size) {
1106                 nf_conntrack_htable_size
1107                         = (((num_physpages << PAGE_SHIFT) / 16384)
1108                            / sizeof(struct hlist_head));
1109                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1110                         nf_conntrack_htable_size = 16384;
1111                 if (nf_conntrack_htable_size < 32)
1112                         nf_conntrack_htable_size = 32;
1113
1114                 /* Use a max. factor of four by default to get the same max as
1115                  * with the old struct list_heads. When a table size is given
1116                  * we use the old value of 8 to avoid reducing the max.
1117                  * entries. */
1118                 max_factor = 4;
1119         }
1120         nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1121                                                   &nf_conntrack_vmalloc);
1122         if (!nf_conntrack_hash) {
1123                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1124                 goto err_out;
1125         }
1126
1127         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1128
1129         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1130                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1131                nf_conntrack_max);
1132
1133         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1134                                                 sizeof(struct nf_conn),
1135                                                 0, 0, NULL);
1136         if (!nf_conntrack_cachep) {
1137                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1138                 goto err_free_hash;
1139         }
1140
1141         ret = nf_conntrack_proto_init();
1142         if (ret < 0)
1143                 goto err_free_conntrack_slab;
1144
1145         ret = nf_conntrack_expect_init();
1146         if (ret < 0)
1147                 goto out_fini_proto;
1148
1149         ret = nf_conntrack_helper_init();
1150         if (ret < 0)
1151                 goto out_fini_expect;
1152
1153         /* For use by REJECT target */
1154         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1155         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1156
1157         /* Set up fake conntrack:
1158             - to never be deleted, not in any hashes */
1159         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1160         /*  - and look it like as a confirmed connection */
1161         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1162
1163         return ret;
1164
1165 out_fini_expect:
1166         nf_conntrack_expect_fini();
1167 out_fini_proto:
1168         nf_conntrack_proto_fini();
1169 err_free_conntrack_slab:
1170         kmem_cache_destroy(nf_conntrack_cachep);
1171 err_free_hash:
1172         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1173                              nf_conntrack_htable_size);
1174 err_out:
1175         return -ENOMEM;
1176 }