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 bool
  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         memset(tuple, 0, sizeof(*tuple));
 108
 109         tuple->src.l3num = l3num;
 110         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 111                 return false;
 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 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 121                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 122 {
 123         struct nf_conntrack_l3proto *l3proto;
 124         struct nf_conntrack_l4proto *l4proto;
 125         unsigned int protoff;
 126         u_int8_t protonum;
 127         int ret;
 128
 129         rcu_read_lock();
 130
 131         l3proto = __nf_ct_l3proto_find(l3num);
 132         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 133         if (ret != NF_ACCEPT) {
 134                 rcu_read_unlock();
 135                 return false;
 136         }
 137
 138         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 139
 140         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 141                               l3proto, l4proto);
 142
 143         rcu_read_unlock();
 144         return ret;
 145 }
 146 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 147
 148 bool
 149 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 150                    const struct nf_conntrack_tuple *orig,
 151                    const struct nf_conntrack_l3proto *l3proto,
 152                    const struct nf_conntrack_l4proto *l4proto)
 153 {
 154         memset(inverse, 0, sizeof(*inverse));
 155
 156         inverse->src.l3num = orig->src.l3num;
 157         if (l3proto->invert_tuple(inverse, orig) == 0)
 158                 return false;
 159
 160         inverse->dst.dir = !orig->dst.dir;
 161
 162         inverse->dst.protonum = orig->dst.protonum;
 163         return l4proto->invert_tuple(inverse, orig);
 164 }
 165 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 166
 167 static void
 168 clean_from_lists(struct nf_conn *ct)
 169 {
 170         pr_debug("clean_from_lists(%p)\n", ct);
 171         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 172         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 173
 174         /* Destroy all pending expectations */
 175         nf_ct_remove_expectations(ct);
 176 }
 177
 178 static void
 179 destroy_conntrack(struct nf_conntrack *nfct)
 180 {
 181         struct nf_conn *ct = (struct nf_conn *)nfct;
 182         struct nf_conntrack_l4proto *l4proto;
 183
 184         pr_debug("destroy_conntrack(%p)\n", ct);
 185         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 186         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 187
 188         nf_conntrack_event(IPCT_DESTROY, ct);
 189         set_bit(IPS_DYING_BIT, &ct->status);
 190
 191         /* To make sure we don't get any weird locking issues here:
 192          * destroy_conntrack() MUST NOT be called with a write lock
 193          * to nf_conntrack_lock!!! -HW */
 194         rcu_read_lock();
 195         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 196         if (l4proto && l4proto->destroy)
 197                 l4proto->destroy(ct);
 198
 199         rcu_read_unlock();
 200
 201         spin_lock_bh(&nf_conntrack_lock);
 202         /* Expectations will have been removed in clean_from_lists,
 203          * except TFTP can create an expectation on the first packet,
 204          * before connection is in the list, so we need to clean here,
 205          * too. */
 206         nf_ct_remove_expectations(ct);
 207
 208         /* We overload first tuple to link into unconfirmed list. */
 209         if (!nf_ct_is_confirmed(ct)) {
 210                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 211                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 212         }
 213
 214         NF_CT_STAT_INC(delete);
 215         spin_unlock_bh(&nf_conntrack_lock);
 216
 217         if (ct->master)
 218                 nf_ct_put(ct->master);
 219
 220         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 221         nf_conntrack_free(ct);
 222 }
 223
 224 static void death_by_timeout(unsigned long ul_conntrack)
 225 {
 226         struct nf_conn *ct = (void *)ul_conntrack;
 227         struct nf_conn_help *help = nfct_help(ct);
 228         struct nf_conntrack_helper *helper;
 229
 230         if (help) {
 231                 rcu_read_lock();
 232                 helper = rcu_dereference(help->helper);
 233                 if (helper && helper->destroy)
 234                         helper->destroy(ct);
 235                 rcu_read_unlock();
 236         }
 237
 238         spin_lock_bh(&nf_conntrack_lock);
 239         /* Inside lock so preempt is disabled on module removal path.
 240          * Otherwise we can get spurious warnings. */
 241         NF_CT_STAT_INC(delete_list);
 242         clean_from_lists(ct);
 243         spin_unlock_bh(&nf_conntrack_lock);
 244         nf_ct_put(ct);
 245 }
 246
 247 struct nf_conntrack_tuple_hash *
 248 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple)
 249 {
 250         struct nf_conntrack_tuple_hash *h;
 251         struct hlist_node *n;
 252         unsigned int hash = hash_conntrack(tuple);
 253
 254         /* Disable BHs the entire time since we normally need to disable them
 255          * at least once for the stats anyway.
 256          */
 257         local_bh_disable();
 258         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 259                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 260                         NF_CT_STAT_INC(found);
 261                         local_bh_enable();
 262                         return h;
 263                 }
 264                 NF_CT_STAT_INC(searched);
 265         }
 266         local_bh_enable();
 267
 268         return NULL;
 269 }
 270 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 271
 272 /* Find a connection corresponding to a tuple. */
 273 struct nf_conntrack_tuple_hash *
 274 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
 275 {
 276         struct nf_conntrack_tuple_hash *h;
 277         struct nf_conn *ct;
 278
 279         rcu_read_lock();
 280         h = __nf_conntrack_find(tuple);
 281         if (h) {
 282                 ct = nf_ct_tuplehash_to_ctrack(h);
 283                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 284                         h = NULL;
 285         }
 286         rcu_read_unlock();
 287
 288         return h;
 289 }
 290 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 291
 292 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 293                                        unsigned int hash,
 294                                        unsigned int repl_hash)
 295 {
 296         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 297                            &nf_conntrack_hash[hash]);
 298         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 299                            &nf_conntrack_hash[repl_hash]);
 300 }
 301
 302 void nf_conntrack_hash_insert(struct nf_conn *ct)
 303 {
 304         unsigned int hash, repl_hash;
 305
 306         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 307         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 308
 309         spin_lock_bh(&nf_conntrack_lock);
 310         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 311         spin_unlock_bh(&nf_conntrack_lock);
 312 }
 313 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 314
 315 /* Confirm a connection given skb; places it in hash table */
 316 int
 317 __nf_conntrack_confirm(struct sk_buff *skb)
 318 {
 319         unsigned int hash, repl_hash;
 320         struct nf_conntrack_tuple_hash *h;
 321         struct nf_conn *ct;
 322         struct nf_conn_help *help;
 323         struct hlist_node *n;
 324         enum ip_conntrack_info ctinfo;
 325
 326         ct = nf_ct_get(skb, &ctinfo);
 327
 328         /* ipt_REJECT uses nf_conntrack_attach to attach related
 329            ICMP/TCP RST packets in other direction.  Actual packet
 330            which created connection will be IP_CT_NEW or for an
 331            expected connection, IP_CT_RELATED. */
 332         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 333                 return NF_ACCEPT;
 334
 335         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 336         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 337
 338         /* We're not in hash table, and we refuse to set up related
 339            connections for unconfirmed conns.  But packet copies and
 340            REJECT will give spurious warnings here. */
 341         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 342
 343         /* No external references means noone else could have
 344            confirmed us. */
 345         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 346         pr_debug("Confirming conntrack %p\n", ct);
 347
 348         spin_lock_bh(&nf_conntrack_lock);
 349
 350         /* See if there's one in the list already, including reverse:
 351            NAT could have grabbed it without realizing, since we're
 352            not in the hash.  If there is, we lost race. */
 353         hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode)
 354                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 355                                       &h->tuple))
 356                         goto out;
 357         hlist_for_each_entry(h, n, &nf_conntrack_hash[repl_hash], hnode)
 358                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 359                                       &h->tuple))
 360                         goto out;
 361
 362         /* Remove from unconfirmed list */
 363         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 364
 365         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 366         /* Timer relative to confirmation time, not original
 367            setting time, otherwise we'd get timer wrap in
 368            weird delay cases. */
 369         ct->timeout.expires += jiffies;
 370         add_timer(&ct->timeout);
 371         atomic_inc(&ct->ct_general.use);
 372         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 373         NF_CT_STAT_INC(insert);
 374         spin_unlock_bh(&nf_conntrack_lock);
 375         help = nfct_help(ct);
 376         if (help && help->helper)
 377                 nf_conntrack_event_cache(IPCT_HELPER, skb);
 378 #ifdef CONFIG_NF_NAT_NEEDED
 379         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 380             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 381                 nf_conntrack_event_cache(IPCT_NATINFO, skb);
 382 #endif
 383         nf_conntrack_event_cache(master_ct(ct) ?
 384                                  IPCT_RELATED : IPCT_NEW, skb);
 385         return NF_ACCEPT;
 386
 387 out:
 388         NF_CT_STAT_INC(insert_failed);
 389         spin_unlock_bh(&nf_conntrack_lock);
 390         return NF_DROP;
 391 }
 392 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 393
 394 /* Returns true if a connection correspondings to the tuple (required
 395    for NAT). */
 396 int
 397 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 398                          const struct nf_conn *ignored_conntrack)
 399 {
 400         struct nf_conntrack_tuple_hash *h;
 401         struct hlist_node *n;
 402         unsigned int hash = hash_conntrack(tuple);
 403
 404         /* Disable BHs the entire time since we need to disable them at
 405          * least once for the stats anyway.
 406          */
 407         rcu_read_lock_bh();
 408         hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
 409                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 410                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 411                         NF_CT_STAT_INC(found);
 412                         rcu_read_unlock_bh();
 413                         return 1;
 414                 }
 415                 NF_CT_STAT_INC(searched);
 416         }
 417         rcu_read_unlock_bh();
 418
 419         return 0;
 420 }
 421 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 422
 423 #define NF_CT_EVICTION_RANGE    8
 424
 425 /* There's a small race here where we may free a just-assured
 426    connection.  Too bad: we're in trouble anyway. */
 427 static noinline int early_drop(unsigned int hash)
 428 {
 429         /* Use oldest entry, which is roughly LRU */
 430         struct nf_conntrack_tuple_hash *h;
 431         struct nf_conn *ct = NULL, *tmp;
 432         struct hlist_node *n;
 433         unsigned int i, cnt = 0;
 434         int dropped = 0;
 435
 436         rcu_read_lock();
 437         for (i = 0; i < nf_conntrack_htable_size; i++) {
 438                 hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
 439                                          hnode) {
 440                         tmp = nf_ct_tuplehash_to_ctrack(h);
 441                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 442                                 ct = tmp;
 443                         cnt++;
 444                 }
 445
 446                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 447                         ct = NULL;
 448                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 449                         break;
 450                 hash = (hash + 1) % nf_conntrack_htable_size;
 451         }
 452         rcu_read_unlock();
 453
 454         if (!ct)
 455                 return dropped;
 456
 457         if (del_timer(&ct->timeout)) {
 458                 death_by_timeout((unsigned long)ct);
 459                 dropped = 1;
 460                 NF_CT_STAT_INC_ATOMIC(early_drop);
 461         }
 462         nf_ct_put(ct);
 463         return dropped;
 464 }
 465
 466 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 467                                    const struct nf_conntrack_tuple *repl,
 468                                    gfp_t gfp)
 469 {
 470         struct nf_conn *ct = NULL;
 471
 472         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 473                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 474                 nf_conntrack_hash_rnd_initted = 1;
 475         }
 476
 477         /* We don't want any race condition at early drop stage */
 478         atomic_inc(&nf_conntrack_count);
 479
 480         if (nf_conntrack_max &&
 481             unlikely(atomic_read(&nf_conntrack_count) > nf_conntrack_max)) {
 482                 unsigned int hash = hash_conntrack(orig);
 483                 if (!early_drop(hash)) {
 484                         atomic_dec(&nf_conntrack_count);
 485                         if (net_ratelimit())
 486                                 printk(KERN_WARNING
 487                                        "nf_conntrack: table full, dropping"
 488                                        " packet.\n");
 489                         return ERR_PTR(-ENOMEM);
 490                 }
 491         }
 492
 493         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 494         if (ct == NULL) {
 495                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 496                 atomic_dec(&nf_conntrack_count);
 497                 return ERR_PTR(-ENOMEM);
 498         }
 499
 500         atomic_set(&ct->ct_general.use, 1);
 501         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 502         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 503         /* Don't set timer yet: wait for confirmation */
 504         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 505         INIT_RCU_HEAD(&ct->rcu);
 506
 507         return ct;
 508 }
 509 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 510
 511 static void nf_conntrack_free_rcu(struct rcu_head *head)
 512 {
 513         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 514
 515         nf_ct_ext_free(ct);
 516         kmem_cache_free(nf_conntrack_cachep, ct);
 517         atomic_dec(&nf_conntrack_count);
 518 }
 519
 520 void nf_conntrack_free(struct nf_conn *ct)
 521 {
 522         nf_ct_ext_destroy(ct);
 523         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 524 }
 525 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 526
 527 /* Allocate a new conntrack: we return -ENOMEM if classification
 528    failed due to stress.  Otherwise it really is unclassifiable. */
 529 static struct nf_conntrack_tuple_hash *
 530 init_conntrack(const struct nf_conntrack_tuple *tuple,
 531                struct nf_conntrack_l3proto *l3proto,
 532                struct nf_conntrack_l4proto *l4proto,
 533                struct sk_buff *skb,
 534                unsigned int dataoff)
 535 {
 536         struct nf_conn *ct;
 537         struct nf_conn_help *help;
 538         struct nf_conntrack_tuple repl_tuple;
 539         struct nf_conntrack_expect *exp;
 540
 541         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 542                 pr_debug("Can't invert tuple.\n");
 543                 return NULL;
 544         }
 545
 546         ct = nf_conntrack_alloc(tuple, &repl_tuple, GFP_ATOMIC);
 547         if (ct == NULL || IS_ERR(ct)) {
 548                 pr_debug("Can't allocate conntrack.\n");
 549                 return (struct nf_conntrack_tuple_hash *)ct;
 550         }
 551
 552         if (!l4proto->new(ct, skb, dataoff)) {
 553                 nf_conntrack_free(ct);
 554                 pr_debug("init conntrack: can't track with proto module\n");
 555                 return NULL;
 556         }
 557
 558         spin_lock_bh(&nf_conntrack_lock);
 559         exp = nf_ct_find_expectation(tuple);
 560         if (exp) {
 561                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 562                          ct, exp);
 563                 /* Welcome, Mr. Bond.  We've been expecting you... */
 564                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 565                 ct->master = exp->master;
 566                 if (exp->helper) {
 567                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 568                         if (help)
 569                                 rcu_assign_pointer(help->helper, exp->helper);
 570                 }
 571
 572 #ifdef CONFIG_NF_CONNTRACK_MARK
 573                 ct->mark = exp->master->mark;
 574 #endif
 575 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 576                 ct->secmark = exp->master->secmark;
 577 #endif
 578                 nf_conntrack_get(&ct->master->ct_general);
 579                 NF_CT_STAT_INC(expect_new);
 580         } else {
 581                 struct nf_conntrack_helper *helper;
 582
 583                 helper = __nf_ct_helper_find(&repl_tuple);
 584                 if (helper) {
 585                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 586                         if (help)
 587                                 rcu_assign_pointer(help->helper, helper);
 588                 }
 589                 NF_CT_STAT_INC(new);
 590         }
 591
 592         /* Overload tuple linked list to put us in unconfirmed list. */
 593         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, &unconfirmed);
 594
 595         spin_unlock_bh(&nf_conntrack_lock);
 596
 597         if (exp) {
 598                 if (exp->expectfn)
 599                         exp->expectfn(ct, exp);
 600                 nf_ct_expect_put(exp);
 601         }
 602
 603         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 604 }
 605
 606 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 607 static inline struct nf_conn *
 608 resolve_normal_ct(struct sk_buff *skb,
 609                   unsigned int dataoff,
 610                   u_int16_t l3num,
 611                   u_int8_t protonum,
 612                   struct nf_conntrack_l3proto *l3proto,
 613                   struct nf_conntrack_l4proto *l4proto,
 614                   int *set_reply,
 615                   enum ip_conntrack_info *ctinfo)
 616 {
 617         struct nf_conntrack_tuple tuple;
 618         struct nf_conntrack_tuple_hash *h;
 619         struct nf_conn *ct;
 620
 621         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 622                              dataoff, l3num, protonum, &tuple, l3proto,
 623                              l4proto)) {
 624                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 625                 return NULL;
 626         }
 627
 628         /* look for tuple match */
 629         h = nf_conntrack_find_get(&tuple);
 630         if (!h) {
 631                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
 632                 if (!h)
 633                         return NULL;
 634                 if (IS_ERR(h))
 635                         return (void *)h;
 636         }
 637         ct = nf_ct_tuplehash_to_ctrack(h);
 638
 639         /* It exists; we have (non-exclusive) reference. */
 640         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 641                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 642                 /* Please set reply bit if this packet OK */
 643                 *set_reply = 1;
 644         } else {
 645                 /* Once we've had two way comms, always ESTABLISHED. */
 646                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 647                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 648                         *ctinfo = IP_CT_ESTABLISHED;
 649                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 650                         pr_debug("nf_conntrack_in: related packet for %p\n",
 651                                  ct);
 652                         *ctinfo = IP_CT_RELATED;
 653                 } else {
 654                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 655                         *ctinfo = IP_CT_NEW;
 656                 }
 657                 *set_reply = 0;
 658         }
 659         skb->nfct = &ct->ct_general;
 660         skb->nfctinfo = *ctinfo;
 661         return ct;
 662 }
 663
 664 unsigned int
 665 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff *skb)
 666 {
 667         struct nf_conn *ct;
 668         enum ip_conntrack_info ctinfo;
 669         struct nf_conntrack_l3proto *l3proto;
 670         struct nf_conntrack_l4proto *l4proto;
 671         unsigned int dataoff;
 672         u_int8_t protonum;
 673         int set_reply = 0;
 674         int ret;
 675
 676         /* Previously seen (loopback or untracked)?  Ignore. */
 677         if (skb->nfct) {
 678                 NF_CT_STAT_INC_ATOMIC(ignore);
 679                 return NF_ACCEPT;
 680         }
 681
 682         /* rcu_read_lock()ed by nf_hook_slow */
 683         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
 684         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 685                                    &dataoff, &protonum);
 686         if (ret <= 0) {
 687                 pr_debug("not prepared to track yet or error occured\n");
 688                 NF_CT_STAT_INC_ATOMIC(error);
 689                 NF_CT_STAT_INC_ATOMIC(invalid);
 690                 return -ret;
 691         }
 692
 693         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
 694
 695         /* It may be an special packet, error, unclean...
 696          * inverse of the return code tells to the netfilter
 697          * core what to do with the packet. */
 698         if (l4proto->error != NULL &&
 699             (ret = l4proto->error(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
 700                 NF_CT_STAT_INC_ATOMIC(error);
 701                 NF_CT_STAT_INC_ATOMIC(invalid);
 702                 return -ret;
 703         }
 704
 705         ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
 706                                &set_reply, &ctinfo);
 707         if (!ct) {
 708                 /* Not valid part of a connection */
 709                 NF_CT_STAT_INC_ATOMIC(invalid);
 710                 return NF_ACCEPT;
 711         }
 712
 713         if (IS_ERR(ct)) {
 714                 /* Too stressed to deal. */
 715                 NF_CT_STAT_INC_ATOMIC(drop);
 716                 return NF_DROP;
 717         }
 718
 719         NF_CT_ASSERT(skb->nfct);
 720
 721         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 722         if (ret < 0) {
 723                 /* Invalid: inverse of the return code tells
 724                  * the netfilter core what to do */
 725                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 726                 nf_conntrack_put(skb->nfct);
 727                 skb->nfct = NULL;
 728                 NF_CT_STAT_INC_ATOMIC(invalid);
 729                 return -ret;
 730         }
 731
 732         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 733                 nf_conntrack_event_cache(IPCT_STATUS, skb);
 734
 735         return ret;
 736 }
 737 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 738
 739 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 740                           const struct nf_conntrack_tuple *orig)
 741 {
 742         bool ret;
 743
 744         rcu_read_lock();
 745         ret = nf_ct_invert_tuple(inverse, orig,
 746                                  __nf_ct_l3proto_find(orig->src.l3num),
 747                                  __nf_ct_l4proto_find(orig->src.l3num,
 748                                                       orig->dst.protonum));
 749         rcu_read_unlock();
 750         return ret;
 751 }
 752 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 753
 754 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 755    implicitly racy: see __nf_conntrack_confirm */
 756 void nf_conntrack_alter_reply(struct nf_conn *ct,
 757                               const struct nf_conntrack_tuple *newreply)
 758 {
 759         struct nf_conn_help *help = nfct_help(ct);
 760         struct nf_conntrack_helper *helper;
 761
 762         /* Should be unconfirmed, so not in hash table yet */
 763         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 764
 765         pr_debug("Altering reply tuple of %p to ", ct);
 766         nf_ct_dump_tuple(newreply);
 767
 768         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 769         if (ct->master || (help && !hlist_empty(&help->expectations)))
 770                 return;
 771
 772         rcu_read_lock();
 773         helper = __nf_ct_helper_find(newreply);
 774         if (helper == NULL) {
 775                 if (help)
 776                         rcu_assign_pointer(help->helper, NULL);
 777                 goto out;
 778         }
 779
 780         if (help == NULL) {
 781                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 782                 if (help == NULL)
 783                         goto out;
 784         } else {
 785                 memset(&help->help, 0, sizeof(help->help));
 786         }
 787
 788         rcu_assign_pointer(help->helper, helper);
 789 out:
 790         rcu_read_unlock();
 791 }
 792 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 793
 794 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 795 void __nf_ct_refresh_acct(struct nf_conn *ct,
 796                           enum ip_conntrack_info ctinfo,
 797                           const struct sk_buff *skb,
 798                           unsigned long extra_jiffies,
 799                           int do_acct)
 800 {
 801         int event = 0;
 802
 803         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 804         NF_CT_ASSERT(skb);
 805
 806         spin_lock_bh(&nf_conntrack_lock);
 807
 808         /* Only update if this is not a fixed timeout */
 809         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 810                 goto acct;
 811
 812         /* If not in hash table, timer will not be active yet */
 813         if (!nf_ct_is_confirmed(ct)) {
 814                 ct->timeout.expires = extra_jiffies;
 815                 event = IPCT_REFRESH;
 816         } else {
 817                 unsigned long newtime = jiffies + extra_jiffies;
 818
 819                 /* Only update the timeout if the new timeout is at least
 820                    HZ jiffies from the old timeout. Need del_timer for race
 821                    avoidance (may already be dying). */
 822                 if (newtime - ct->timeout.expires >= HZ
 823                     && del_timer(&ct->timeout)) {
 824                         ct->timeout.expires = newtime;
 825                         add_timer(&ct->timeout);
 826                         event = IPCT_REFRESH;
 827                 }
 828         }
 829
 830 acct:
 831 #ifdef CONFIG_NF_CT_ACCT
 832         if (do_acct) {
 833                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
 834                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
 835                         skb->len - skb_network_offset(skb);
 836
 837                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
 838                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
 839                         event |= IPCT_COUNTER_FILLING;
 840         }
 841 #endif
 842
 843         spin_unlock_bh(&nf_conntrack_lock);
 844
 845         /* must be unlocked when calling event cache */
 846         if (event)
 847                 nf_conntrack_event_cache(event, skb);
 848 }
 849 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 850
 851 bool __nf_ct_kill_acct(struct nf_conn *ct,
 852                        enum ip_conntrack_info ctinfo,
 853                        const struct sk_buff *skb,
 854                        int do_acct)
 855 {
 856 #ifdef CONFIG_NF_CT_ACCT
 857         if (do_acct) {
 858                 spin_lock_bh(&nf_conntrack_lock);
 859                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
 860                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
 861                         skb->len - skb_network_offset(skb);
 862                 spin_unlock_bh(&nf_conntrack_lock);
 863         }
 864 #endif
 865         if (del_timer(&ct->timeout)) {
 866                 ct->timeout.function((unsigned long)ct);
 867                 return true;
 868         }
 869         return false;
 870 }
 871 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 872
 873 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 874
 875 #include <linux/netfilter/nfnetlink.h>
 876 #include <linux/netfilter/nfnetlink_conntrack.h>
 877 #include <linux/mutex.h>
 878
 879 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 880  * in ip_conntrack_core, since we don't want the protocols to autoload
 881  * or depend on ctnetlink */
 882 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 883                                const struct nf_conntrack_tuple *tuple)
 884 {
 885         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 886         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 887         return 0;
 888
 889 nla_put_failure:
 890         return -1;
 891 }
 892 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 893
 894 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 895         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 896         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 897 };
 898 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 899
 900 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 901                                struct nf_conntrack_tuple *t)
 902 {
 903         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 904                 return -EINVAL;
 905
 906         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 907         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 908
 909         return 0;
 910 }
 911 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 912 #endif
 913
 914 /* Used by ipt_REJECT and ip6t_REJECT. */
 915 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 916 {
 917         struct nf_conn *ct;
 918         enum ip_conntrack_info ctinfo;
 919
 920         /* This ICMP is in reverse direction to the packet which caused it */
 921         ct = nf_ct_get(skb, &ctinfo);
 922         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 923                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 924         else
 925                 ctinfo = IP_CT_RELATED;
 926
 927         /* Attach to new skbuff, and increment count */
 928         nskb->nfct = &ct->ct_general;
 929         nskb->nfctinfo = ctinfo;
 930         nf_conntrack_get(nskb->nfct);
 931 }
 932
 933 /* Bring out ya dead! */
 934 static struct nf_conn *
 935 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
 936                 void *data, unsigned int *bucket)
 937 {
 938         struct nf_conntrack_tuple_hash *h;
 939         struct nf_conn *ct;
 940         struct hlist_node *n;
 941
 942         spin_lock_bh(&nf_conntrack_lock);
 943         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 944                 hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) {
 945                         ct = nf_ct_tuplehash_to_ctrack(h);
 946                         if (iter(ct, data))
 947                                 goto found;
 948                 }
 949         }
 950         hlist_for_each_entry(h, n, &unconfirmed, hnode) {
 951                 ct = nf_ct_tuplehash_to_ctrack(h);
 952                 if (iter(ct, data))
 953                         set_bit(IPS_DYING_BIT, &ct->status);
 954         }
 955         spin_unlock_bh(&nf_conntrack_lock);
 956         return NULL;
 957 found:
 958         atomic_inc(&ct->ct_general.use);
 959         spin_unlock_bh(&nf_conntrack_lock);
 960         return ct;
 961 }
 962
 963 void
 964 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
 965 {
 966         struct nf_conn *ct;
 967         unsigned int bucket = 0;
 968
 969         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
 970                 /* Time to push up daises... */
 971                 if (del_timer(&ct->timeout))
 972                         death_by_timeout((unsigned long)ct);
 973                 /* ... else the timer will get him soon. */
 974
 975                 nf_ct_put(ct);
 976         }
 977 }
 978 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 979
 980 static int kill_all(struct nf_conn *i, void *data)
 981 {
 982         return 1;
 983 }
 984
 985 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 986 {
 987         if (vmalloced)
 988                 vfree(hash);
 989         else
 990                 free_pages((unsigned long)hash,
 991                            get_order(sizeof(struct hlist_head) * size));
 992 }
 993 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
 994
 995 void nf_conntrack_flush(void)
 996 {
 997         nf_ct_iterate_cleanup(kill_all, NULL);
 998 }
 999 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1000
1001 /* Mishearing the voices in his head, our hero wonders how he's
1002    supposed to kill the mall. */
1003 void nf_conntrack_cleanup(void)
1004 {
1005         rcu_assign_pointer(ip_ct_attach, NULL);
1006
1007         /* This makes sure all current packets have passed through
1008            netfilter framework.  Roll on, two-stage module
1009            delete... */
1010         synchronize_net();
1011
1012         nf_ct_event_cache_flush();
1013  i_see_dead_people:
1014         nf_conntrack_flush();
1015         if (atomic_read(&nf_conntrack_count) != 0) {
1016                 schedule();
1017                 goto i_see_dead_people;
1018         }
1019         /* wait until all references to nf_conntrack_untracked are dropped */
1020         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1021                 schedule();
1022
1023         rcu_assign_pointer(nf_ct_destroy, NULL);
1024
1025         kmem_cache_destroy(nf_conntrack_cachep);
1026         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1027                              nf_conntrack_htable_size);
1028
1029         nf_conntrack_proto_fini();
1030         nf_conntrack_helper_fini();
1031         nf_conntrack_expect_fini();
1032 }
1033
1034 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1035 {
1036         struct hlist_head *hash;
1037         unsigned int size, i;
1038
1039         *vmalloced = 0;
1040
1041         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1042         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1043                                        get_order(sizeof(struct hlist_head)
1044                                                  * size));
1045         if (!hash) {
1046                 *vmalloced = 1;
1047                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1048                 hash = vmalloc(sizeof(struct hlist_head) * size);
1049         }
1050
1051         if (hash)
1052                 for (i = 0; i < size; i++)
1053                         INIT_HLIST_HEAD(&hash[i]);
1054
1055         return hash;
1056 }
1057 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1058
1059 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1060 {
1061         int i, bucket, vmalloced, old_vmalloced;
1062         unsigned int hashsize, old_size;
1063         int rnd;
1064         struct hlist_head *hash, *old_hash;
1065         struct nf_conntrack_tuple_hash *h;
1066
1067         /* On boot, we can set this without any fancy locking. */
1068         if (!nf_conntrack_htable_size)
1069                 return param_set_uint(val, kp);
1070
1071         hashsize = simple_strtoul(val, NULL, 0);
1072         if (!hashsize)
1073                 return -EINVAL;
1074
1075         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1076         if (!hash)
1077                 return -ENOMEM;
1078
1079         /* We have to rehahs for the new table anyway, so we also can
1080          * use a newrandom seed */
1081         get_random_bytes(&rnd, 4);
1082
1083         /* Lookups in the old hash might happen in parallel, which means we
1084          * might get false negatives during connection lookup. New connections
1085          * created because of a false negative won't make it into the hash
1086          * though since that required taking the lock.
1087          */
1088         spin_lock_bh(&nf_conntrack_lock);
1089         for (i = 0; i < nf_conntrack_htable_size; i++) {
1090                 while (!hlist_empty(&nf_conntrack_hash[i])) {
1091                         h = hlist_entry(nf_conntrack_hash[i].first,
1092                                         struct nf_conntrack_tuple_hash, hnode);
1093                         hlist_del_rcu(&h->hnode);
1094                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1095                         hlist_add_head(&h->hnode, &hash[bucket]);
1096                 }
1097         }
1098         old_size = nf_conntrack_htable_size;
1099         old_vmalloced = nf_conntrack_vmalloc;
1100         old_hash = nf_conntrack_hash;
1101
1102         nf_conntrack_htable_size = hashsize;
1103         nf_conntrack_vmalloc = vmalloced;
1104         nf_conntrack_hash = hash;
1105         nf_conntrack_hash_rnd = rnd;
1106         spin_unlock_bh(&nf_conntrack_lock);
1107
1108         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1109         return 0;
1110 }
1111 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1112
1113 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1114                   &nf_conntrack_htable_size, 0600);
1115
1116 int __init nf_conntrack_init(void)
1117 {
1118         int max_factor = 8;
1119         int ret;
1120
1121         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1122          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1123         if (!nf_conntrack_htable_size) {
1124                 nf_conntrack_htable_size
1125                         = (((num_physpages << PAGE_SHIFT) / 16384)
1126                            / sizeof(struct hlist_head));
1127                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1128                         nf_conntrack_htable_size = 16384;
1129                 if (nf_conntrack_htable_size < 32)
1130                         nf_conntrack_htable_size = 32;
1131
1132                 /* Use a max. factor of four by default to get the same max as
1133                  * with the old struct list_heads. When a table size is given
1134                  * we use the old value of 8 to avoid reducing the max.
1135                  * entries. */
1136                 max_factor = 4;
1137         }
1138         nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1139                                                   &nf_conntrack_vmalloc);
1140         if (!nf_conntrack_hash) {
1141                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1142                 goto err_out;
1143         }
1144
1145         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1146
1147         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1148                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1149                nf_conntrack_max);
1150
1151         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1152                                                 sizeof(struct nf_conn),
1153                                                 0, 0, NULL);
1154         if (!nf_conntrack_cachep) {
1155                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1156                 goto err_free_hash;
1157         }
1158
1159         ret = nf_conntrack_proto_init();
1160         if (ret < 0)
1161                 goto err_free_conntrack_slab;
1162
1163         ret = nf_conntrack_expect_init();
1164         if (ret < 0)
1165                 goto out_fini_proto;
1166
1167         ret = nf_conntrack_helper_init();
1168         if (ret < 0)
1169                 goto out_fini_expect;
1170
1171         /* For use by REJECT target */
1172         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1173         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1174
1175         /* Set up fake conntrack:
1176             - to never be deleted, not in any hashes */
1177         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1178         /*  - and look it like as a confirmed connection */
1179         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1180
1181         return ret;
1182
1183 out_fini_expect:
1184         nf_conntrack_expect_fini();
1185 out_fini_proto:
1186         nf_conntrack_proto_fini();
1187 err_free_conntrack_slab:
1188         kmem_cache_destroy(nf_conntrack_cachep);
1189 err_free_hash:
1190         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1191                              nf_conntrack_htable_size);
1192 err_out:
1193         return -ENOMEM;
1194 }