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 #include <net/netfilter/nf_conntrack_acct.h>
  41
  42 #define NF_CONNTRACK_VERSION    "0.5.0"
  43
  44 DEFINE_SPINLOCK(nf_conntrack_lock);
  45 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  46
  47 unsigned int nf_conntrack_htable_size __read_mostly;
  48 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
  49
  50 int nf_conntrack_max __read_mostly;
  51 EXPORT_SYMBOL_GPL(nf_conntrack_max);
  52
  53 struct nf_conn nf_conntrack_untracked __read_mostly;
  54 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
  55
  56 unsigned int nf_ct_log_invalid __read_mostly;
  57 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  58
  59 static int nf_conntrack_hash_rnd_initted;
  60 static unsigned int nf_conntrack_hash_rnd;
  61
  62 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  63                                   unsigned int size, unsigned int rnd)
  64 {
  65         unsigned int n;
  66         u_int32_t h;
  67
  68         /* The direction must be ignored, so we hash everything up to the
  69          * destination ports (which is a multiple of 4) and treat the last
  70          * three bytes manually.
  71          */
  72         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  73         h = jhash2((u32 *)tuple, n,
  74                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  75                           tuple->dst.protonum));
  76
  77         return ((u64)h * size) >> 32;
  78 }
  79
  80 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  81 {
  82         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  83                                 nf_conntrack_hash_rnd);
  84 }
  85
  86 bool
  87 nf_ct_get_tuple(const struct sk_buff *skb,
  88                 unsigned int nhoff,
  89                 unsigned int dataoff,
  90                 u_int16_t l3num,
  91                 u_int8_t protonum,
  92                 struct nf_conntrack_tuple *tuple,
  93                 const struct nf_conntrack_l3proto *l3proto,
  94                 const struct nf_conntrack_l4proto *l4proto)
  95 {
  96         memset(tuple, 0, sizeof(*tuple));
  97
  98         tuple->src.l3num = l3num;
  99         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 100                 return false;
 101
 102         tuple->dst.protonum = protonum;
 103         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 104
 105         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 106 }
 107 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 108
 109 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 110                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 111 {
 112         struct nf_conntrack_l3proto *l3proto;
 113         struct nf_conntrack_l4proto *l4proto;
 114         unsigned int protoff;
 115         u_int8_t protonum;
 116         int ret;
 117
 118         rcu_read_lock();
 119
 120         l3proto = __nf_ct_l3proto_find(l3num);
 121         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 122         if (ret != NF_ACCEPT) {
 123                 rcu_read_unlock();
 124                 return false;
 125         }
 126
 127         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 128
 129         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 130                               l3proto, l4proto);
 131
 132         rcu_read_unlock();
 133         return ret;
 134 }
 135 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 136
 137 bool
 138 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 139                    const struct nf_conntrack_tuple *orig,
 140                    const struct nf_conntrack_l3proto *l3proto,
 141                    const struct nf_conntrack_l4proto *l4proto)
 142 {
 143         memset(inverse, 0, sizeof(*inverse));
 144
 145         inverse->src.l3num = orig->src.l3num;
 146         if (l3proto->invert_tuple(inverse, orig) == 0)
 147                 return false;
 148
 149         inverse->dst.dir = !orig->dst.dir;
 150
 151         inverse->dst.protonum = orig->dst.protonum;
 152         return l4proto->invert_tuple(inverse, orig);
 153 }
 154 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 155
 156 static void
 157 clean_from_lists(struct nf_conn *ct)
 158 {
 159         pr_debug("clean_from_lists(%p)\n", ct);
 160         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 161         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 162
 163         /* Destroy all pending expectations */
 164         nf_ct_remove_expectations(ct);
 165 }
 166
 167 static void
 168 destroy_conntrack(struct nf_conntrack *nfct)
 169 {
 170         struct nf_conn *ct = (struct nf_conn *)nfct;
 171         struct net *net = nf_ct_net(ct);
 172         struct nf_conntrack_l4proto *l4proto;
 173
 174         pr_debug("destroy_conntrack(%p)\n", ct);
 175         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 176         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 177
 178         nf_conntrack_event(IPCT_DESTROY, ct);
 179         set_bit(IPS_DYING_BIT, &ct->status);
 180
 181         /* To make sure we don't get any weird locking issues here:
 182          * destroy_conntrack() MUST NOT be called with a write lock
 183          * to nf_conntrack_lock!!! -HW */
 184         rcu_read_lock();
 185         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 186         if (l4proto && l4proto->destroy)
 187                 l4proto->destroy(ct);
 188
 189         rcu_read_unlock();
 190
 191         spin_lock_bh(&nf_conntrack_lock);
 192         /* Expectations will have been removed in clean_from_lists,
 193          * except TFTP can create an expectation on the first packet,
 194          * before connection is in the list, so we need to clean here,
 195          * too. */
 196         nf_ct_remove_expectations(ct);
 197
 198         /* We overload first tuple to link into unconfirmed list. */
 199         if (!nf_ct_is_confirmed(ct)) {
 200                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 201                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 202         }
 203
 204         NF_CT_STAT_INC(net, delete);
 205         spin_unlock_bh(&nf_conntrack_lock);
 206
 207         if (ct->master)
 208                 nf_ct_put(ct->master);
 209
 210         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 211         nf_conntrack_free(ct);
 212 }
 213
 214 static void death_by_timeout(unsigned long ul_conntrack)
 215 {
 216         struct nf_conn *ct = (void *)ul_conntrack;
 217         struct net *net = nf_ct_net(ct);
 218         struct nf_conn_help *help = nfct_help(ct);
 219         struct nf_conntrack_helper *helper;
 220
 221         if (help) {
 222                 rcu_read_lock();
 223                 helper = rcu_dereference(help->helper);
 224                 if (helper && helper->destroy)
 225                         helper->destroy(ct);
 226                 rcu_read_unlock();
 227         }
 228
 229         spin_lock_bh(&nf_conntrack_lock);
 230         /* Inside lock so preempt is disabled on module removal path.
 231          * Otherwise we can get spurious warnings. */
 232         NF_CT_STAT_INC(net, delete_list);
 233         clean_from_lists(ct);
 234         spin_unlock_bh(&nf_conntrack_lock);
 235         nf_ct_put(ct);
 236 }
 237
 238 struct nf_conntrack_tuple_hash *
 239 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 240 {
 241         struct nf_conntrack_tuple_hash *h;
 242         struct hlist_node *n;
 243         unsigned int hash = hash_conntrack(tuple);
 244
 245         /* Disable BHs the entire time since we normally need to disable them
 246          * at least once for the stats anyway.
 247          */
 248         local_bh_disable();
 249         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 250                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 251                         NF_CT_STAT_INC(net, found);
 252                         local_bh_enable();
 253                         return h;
 254                 }
 255                 NF_CT_STAT_INC(net, searched);
 256         }
 257         local_bh_enable();
 258
 259         return NULL;
 260 }
 261 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 262
 263 /* Find a connection corresponding to a tuple. */
 264 struct nf_conntrack_tuple_hash *
 265 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 266 {
 267         struct nf_conntrack_tuple_hash *h;
 268         struct nf_conn *ct;
 269
 270         rcu_read_lock();
 271         h = __nf_conntrack_find(net, tuple);
 272         if (h) {
 273                 ct = nf_ct_tuplehash_to_ctrack(h);
 274                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 275                         h = NULL;
 276         }
 277         rcu_read_unlock();
 278
 279         return h;
 280 }
 281 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 282
 283 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 284                                        unsigned int hash,
 285                                        unsigned int repl_hash)
 286 {
 287         struct net *net = nf_ct_net(ct);
 288
 289         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 290                            &net->ct.hash[hash]);
 291         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 292                            &net->ct.hash[repl_hash]);
 293 }
 294
 295 void nf_conntrack_hash_insert(struct nf_conn *ct)
 296 {
 297         unsigned int hash, repl_hash;
 298
 299         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 300         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 301
 302         spin_lock_bh(&nf_conntrack_lock);
 303         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 304         spin_unlock_bh(&nf_conntrack_lock);
 305 }
 306 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 307
 308 /* Confirm a connection given skb; places it in hash table */
 309 int
 310 __nf_conntrack_confirm(struct sk_buff *skb)
 311 {
 312         unsigned int hash, repl_hash;
 313         struct nf_conntrack_tuple_hash *h;
 314         struct nf_conn *ct;
 315         struct nf_conn_help *help;
 316         struct hlist_node *n;
 317         enum ip_conntrack_info ctinfo;
 318         struct net *net;
 319
 320         ct = nf_ct_get(skb, &ctinfo);
 321         net = nf_ct_net(ct);
 322
 323         /* ipt_REJECT uses nf_conntrack_attach to attach related
 324            ICMP/TCP RST packets in other direction.  Actual packet
 325            which created connection will be IP_CT_NEW or for an
 326            expected connection, IP_CT_RELATED. */
 327         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 328                 return NF_ACCEPT;
 329
 330         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 331         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 332
 333         /* We're not in hash table, and we refuse to set up related
 334            connections for unconfirmed conns.  But packet copies and
 335            REJECT will give spurious warnings here. */
 336         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 337
 338         /* No external references means noone else could have
 339            confirmed us. */
 340         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 341         pr_debug("Confirming conntrack %p\n", ct);
 342
 343         spin_lock_bh(&nf_conntrack_lock);
 344
 345         /* See if there's one in the list already, including reverse:
 346            NAT could have grabbed it without realizing, since we're
 347            not in the hash.  If there is, we lost race. */
 348         hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode)
 349                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 350                                       &h->tuple))
 351                         goto out;
 352         hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode)
 353                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 354                                       &h->tuple))
 355                         goto out;
 356
 357         /* Remove from unconfirmed list */
 358         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 359
 360         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 361         /* Timer relative to confirmation time, not original
 362            setting time, otherwise we'd get timer wrap in
 363            weird delay cases. */
 364         ct->timeout.expires += jiffies;
 365         add_timer(&ct->timeout);
 366         atomic_inc(&ct->ct_general.use);
 367         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 368         NF_CT_STAT_INC(net, insert);
 369         spin_unlock_bh(&nf_conntrack_lock);
 370         help = nfct_help(ct);
 371         if (help && help->helper)
 372                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 373 #ifdef CONFIG_NF_NAT_NEEDED
 374         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 375             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 376                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
 377 #endif
 378         nf_conntrack_event_cache(master_ct(ct) ?
 379                                  IPCT_RELATED : IPCT_NEW, ct);
 380         return NF_ACCEPT;
 381
 382 out:
 383         NF_CT_STAT_INC(net, insert_failed);
 384         spin_unlock_bh(&nf_conntrack_lock);
 385         return NF_DROP;
 386 }
 387 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 388
 389 /* Returns true if a connection correspondings to the tuple (required
 390    for NAT). */
 391 int
 392 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 393                          const struct nf_conn *ignored_conntrack)
 394 {
 395         struct net *net = nf_ct_net(ignored_conntrack);
 396         struct nf_conntrack_tuple_hash *h;
 397         struct hlist_node *n;
 398         unsigned int hash = hash_conntrack(tuple);
 399
 400         /* Disable BHs the entire time since we need to disable them at
 401          * least once for the stats anyway.
 402          */
 403         rcu_read_lock_bh();
 404         hlist_for_each_entry_rcu(h, n, &net->ct.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(net, found);
 408                         rcu_read_unlock_bh();
 409                         return 1;
 410                 }
 411                 NF_CT_STAT_INC(net, searched);
 412         }
 413         rcu_read_unlock_bh();
 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 noinline int early_drop(struct net *net, 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, &net->ct.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(net, early_drop);
 457         }
 458         nf_ct_put(ct);
 459         return dropped;
 460 }
 461
 462 struct nf_conn *nf_conntrack_alloc(struct net *net,
 463                                    const struct nf_conntrack_tuple *orig,
 464                                    const struct nf_conntrack_tuple *repl,
 465                                    gfp_t gfp)
 466 {
 467         struct nf_conn *ct = NULL;
 468
 469         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 470                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 471                 nf_conntrack_hash_rnd_initted = 1;
 472         }
 473
 474         /* We don't want any race condition at early drop stage */
 475         atomic_inc(&net->ct.count);
 476
 477         if (nf_conntrack_max &&
 478             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 479                 unsigned int hash = hash_conntrack(orig);
 480                 if (!early_drop(net, hash)) {
 481                         atomic_dec(&net->ct.count);
 482                         if (net_ratelimit())
 483                                 printk(KERN_WARNING
 484                                        "nf_conntrack: table full, dropping"
 485                                        " packet.\n");
 486                         return ERR_PTR(-ENOMEM);
 487                 }
 488         }
 489
 490         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 491         if (ct == NULL) {
 492                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 493                 atomic_dec(&net->ct.count);
 494                 return ERR_PTR(-ENOMEM);
 495         }
 496
 497         atomic_set(&ct->ct_general.use, 1);
 498         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 499         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 500         /* Don't set timer yet: wait for confirmation */
 501         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 502 #ifdef CONFIG_NET_NS
 503         ct->ct_net = net;
 504 #endif
 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         struct net *net = nf_ct_net(ct);
 515
 516         nf_ct_ext_free(ct);
 517         kmem_cache_free(nf_conntrack_cachep, ct);
 518         atomic_dec(&net->ct.count);
 519 }
 520
 521 void nf_conntrack_free(struct nf_conn *ct)
 522 {
 523         nf_ct_ext_destroy(ct);
 524         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 525 }
 526 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 527
 528 /* Allocate a new conntrack: we return -ENOMEM if classification
 529    failed due to stress.  Otherwise it really is unclassifiable. */
 530 static struct nf_conntrack_tuple_hash *
 531 init_conntrack(struct net *net,
 532                const struct nf_conntrack_tuple *tuple,
 533                struct nf_conntrack_l3proto *l3proto,
 534                struct nf_conntrack_l4proto *l4proto,
 535                struct sk_buff *skb,
 536                unsigned int dataoff)
 537 {
 538         struct nf_conn *ct;
 539         struct nf_conn_help *help;
 540         struct nf_conntrack_tuple repl_tuple;
 541         struct nf_conntrack_expect *exp;
 542
 543         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 544                 pr_debug("Can't invert tuple.\n");
 545                 return NULL;
 546         }
 547
 548         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 549         if (ct == NULL || IS_ERR(ct)) {
 550                 pr_debug("Can't allocate conntrack.\n");
 551                 return (struct nf_conntrack_tuple_hash *)ct;
 552         }
 553
 554         if (!l4proto->new(ct, skb, dataoff)) {
 555                 nf_conntrack_free(ct);
 556                 pr_debug("init conntrack: can't track with proto module\n");
 557                 return NULL;
 558         }
 559
 560         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 561
 562         spin_lock_bh(&nf_conntrack_lock);
 563         exp = nf_ct_find_expectation(net, tuple);
 564         if (exp) {
 565                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 566                          ct, exp);
 567                 /* Welcome, Mr. Bond.  We've been expecting you... */
 568                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 569                 ct->master = exp->master;
 570                 if (exp->helper) {
 571                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 572                         if (help)
 573                                 rcu_assign_pointer(help->helper, exp->helper);
 574                 }
 575
 576 #ifdef CONFIG_NF_CONNTRACK_MARK
 577                 ct->mark = exp->master->mark;
 578 #endif
 579 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 580                 ct->secmark = exp->master->secmark;
 581 #endif
 582                 nf_conntrack_get(&ct->master->ct_general);
 583                 NF_CT_STAT_INC(net, expect_new);
 584         } else {
 585                 struct nf_conntrack_helper *helper;
 586
 587                 helper = __nf_ct_helper_find(&repl_tuple);
 588                 if (helper) {
 589                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 590                         if (help)
 591                                 rcu_assign_pointer(help->helper, helper);
 592                 }
 593                 NF_CT_STAT_INC(net, new);
 594         }
 595
 596         /* Overload tuple linked list to put us in unconfirmed list. */
 597         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 598                        &net->ct.unconfirmed);
 599
 600         spin_unlock_bh(&nf_conntrack_lock);
 601
 602         if (exp) {
 603                 if (exp->expectfn)
 604                         exp->expectfn(ct, exp);
 605                 nf_ct_expect_put(exp);
 606         }
 607
 608         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 609 }
 610
 611 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 612 static inline struct nf_conn *
 613 resolve_normal_ct(struct net *net,
 614                   struct sk_buff *skb,
 615                   unsigned int dataoff,
 616                   u_int16_t l3num,
 617                   u_int8_t protonum,
 618                   struct nf_conntrack_l3proto *l3proto,
 619                   struct nf_conntrack_l4proto *l4proto,
 620                   int *set_reply,
 621                   enum ip_conntrack_info *ctinfo)
 622 {
 623         struct nf_conntrack_tuple tuple;
 624         struct nf_conntrack_tuple_hash *h;
 625         struct nf_conn *ct;
 626
 627         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 628                              dataoff, l3num, protonum, &tuple, l3proto,
 629                              l4proto)) {
 630                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 631                 return NULL;
 632         }
 633
 634         /* look for tuple match */
 635         h = nf_conntrack_find_get(net, &tuple);
 636         if (!h) {
 637                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
 638                 if (!h)
 639                         return NULL;
 640                 if (IS_ERR(h))
 641                         return (void *)h;
 642         }
 643         ct = nf_ct_tuplehash_to_ctrack(h);
 644
 645         /* It exists; we have (non-exclusive) reference. */
 646         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 647                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 648                 /* Please set reply bit if this packet OK */
 649                 *set_reply = 1;
 650         } else {
 651                 /* Once we've had two way comms, always ESTABLISHED. */
 652                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 653                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 654                         *ctinfo = IP_CT_ESTABLISHED;
 655                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 656                         pr_debug("nf_conntrack_in: related packet for %p\n",
 657                                  ct);
 658                         *ctinfo = IP_CT_RELATED;
 659                 } else {
 660                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 661                         *ctinfo = IP_CT_NEW;
 662                 }
 663                 *set_reply = 0;
 664         }
 665         skb->nfct = &ct->ct_general;
 666         skb->nfctinfo = *ctinfo;
 667         return ct;
 668 }
 669
 670 unsigned int
 671 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
 672                 struct sk_buff *skb)
 673 {
 674         struct nf_conn *ct;
 675         enum ip_conntrack_info ctinfo;
 676         struct nf_conntrack_l3proto *l3proto;
 677         struct nf_conntrack_l4proto *l4proto;
 678         unsigned int dataoff;
 679         u_int8_t protonum;
 680         int set_reply = 0;
 681         int ret;
 682
 683         /* Previously seen (loopback or untracked)?  Ignore. */
 684         if (skb->nfct) {
 685                 NF_CT_STAT_INC_ATOMIC(net, ignore);
 686                 return NF_ACCEPT;
 687         }
 688
 689         /* rcu_read_lock()ed by nf_hook_slow */
 690         l3proto = __nf_ct_l3proto_find(pf);
 691         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 692                                    &dataoff, &protonum);
 693         if (ret <= 0) {
 694                 pr_debug("not prepared to track yet or error occured\n");
 695                 NF_CT_STAT_INC_ATOMIC(net, error);
 696                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 697                 return -ret;
 698         }
 699
 700         l4proto = __nf_ct_l4proto_find(pf, protonum);
 701
 702         /* It may be an special packet, error, unclean...
 703          * inverse of the return code tells to the netfilter
 704          * core what to do with the packet. */
 705         if (l4proto->error != NULL) {
 706                 ret = l4proto->error(net, skb, dataoff, &ctinfo, pf, hooknum);
 707                 if (ret <= 0) {
 708                         NF_CT_STAT_INC_ATOMIC(net, error);
 709                         NF_CT_STAT_INC_ATOMIC(net, invalid);
 710                         return -ret;
 711                 }
 712         }
 713
 714         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
 715                                l3proto, l4proto, &set_reply, &ctinfo);
 716         if (!ct) {
 717                 /* Not valid part of a connection */
 718                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 719                 return NF_ACCEPT;
 720         }
 721
 722         if (IS_ERR(ct)) {
 723                 /* Too stressed to deal. */
 724                 NF_CT_STAT_INC_ATOMIC(net, drop);
 725                 return NF_DROP;
 726         }
 727
 728         NF_CT_ASSERT(skb->nfct);
 729
 730         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 731         if (ret < 0) {
 732                 /* Invalid: inverse of the return code tells
 733                  * the netfilter core what to do */
 734                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 735                 nf_conntrack_put(skb->nfct);
 736                 skb->nfct = NULL;
 737                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 738                 return -ret;
 739         }
 740
 741         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 742                 nf_conntrack_event_cache(IPCT_STATUS, ct);
 743
 744         return ret;
 745 }
 746 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 747
 748 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 749                           const struct nf_conntrack_tuple *orig)
 750 {
 751         bool ret;
 752
 753         rcu_read_lock();
 754         ret = nf_ct_invert_tuple(inverse, orig,
 755                                  __nf_ct_l3proto_find(orig->src.l3num),
 756                                  __nf_ct_l4proto_find(orig->src.l3num,
 757                                                       orig->dst.protonum));
 758         rcu_read_unlock();
 759         return ret;
 760 }
 761 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 762
 763 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 764    implicitly racy: see __nf_conntrack_confirm */
 765 void nf_conntrack_alter_reply(struct nf_conn *ct,
 766                               const struct nf_conntrack_tuple *newreply)
 767 {
 768         struct nf_conn_help *help = nfct_help(ct);
 769         struct nf_conntrack_helper *helper;
 770
 771         /* Should be unconfirmed, so not in hash table yet */
 772         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 773
 774         pr_debug("Altering reply tuple of %p to ", ct);
 775         nf_ct_dump_tuple(newreply);
 776
 777         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 778         if (ct->master || (help && !hlist_empty(&help->expectations)))
 779                 return;
 780
 781         rcu_read_lock();
 782         helper = __nf_ct_helper_find(newreply);
 783         if (helper == NULL) {
 784                 if (help)
 785                         rcu_assign_pointer(help->helper, NULL);
 786                 goto out;
 787         }
 788
 789         if (help == NULL) {
 790                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 791                 if (help == NULL)
 792                         goto out;
 793         } else {
 794                 memset(&help->help, 0, sizeof(help->help));
 795         }
 796
 797         rcu_assign_pointer(help->helper, helper);
 798 out:
 799         rcu_read_unlock();
 800 }
 801 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 802
 803 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 804 void __nf_ct_refresh_acct(struct nf_conn *ct,
 805                           enum ip_conntrack_info ctinfo,
 806                           const struct sk_buff *skb,
 807                           unsigned long extra_jiffies,
 808                           int do_acct)
 809 {
 810         int event = 0;
 811
 812         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 813         NF_CT_ASSERT(skb);
 814
 815         spin_lock_bh(&nf_conntrack_lock);
 816
 817         /* Only update if this is not a fixed timeout */
 818         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 819                 goto acct;
 820
 821         /* If not in hash table, timer will not be active yet */
 822         if (!nf_ct_is_confirmed(ct)) {
 823                 ct->timeout.expires = extra_jiffies;
 824                 event = IPCT_REFRESH;
 825         } else {
 826                 unsigned long newtime = jiffies + extra_jiffies;
 827
 828                 /* Only update the timeout if the new timeout is at least
 829                    HZ jiffies from the old timeout. Need del_timer for race
 830                    avoidance (may already be dying). */
 831                 if (newtime - ct->timeout.expires >= HZ
 832                     && del_timer(&ct->timeout)) {
 833                         ct->timeout.expires = newtime;
 834                         add_timer(&ct->timeout);
 835                         event = IPCT_REFRESH;
 836                 }
 837         }
 838
 839 acct:
 840         if (do_acct) {
 841                 struct nf_conn_counter *acct;
 842
 843                 acct = nf_conn_acct_find(ct);
 844                 if (acct) {
 845                         acct[CTINFO2DIR(ctinfo)].packets++;
 846                         acct[CTINFO2DIR(ctinfo)].bytes +=
 847                                 skb->len - skb_network_offset(skb);
 848                 }
 849         }
 850
 851         spin_unlock_bh(&nf_conntrack_lock);
 852
 853         /* must be unlocked when calling event cache */
 854         if (event)
 855                 nf_conntrack_event_cache(event, ct);
 856 }
 857 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 858
 859 bool __nf_ct_kill_acct(struct nf_conn *ct,
 860                        enum ip_conntrack_info ctinfo,
 861                        const struct sk_buff *skb,
 862                        int do_acct)
 863 {
 864         if (do_acct) {
 865                 struct nf_conn_counter *acct;
 866
 867                 spin_lock_bh(&nf_conntrack_lock);
 868                 acct = nf_conn_acct_find(ct);
 869                 if (acct) {
 870                         acct[CTINFO2DIR(ctinfo)].packets++;
 871                         acct[CTINFO2DIR(ctinfo)].bytes +=
 872                                 skb->len - skb_network_offset(skb);
 873                 }
 874                 spin_unlock_bh(&nf_conntrack_lock);
 875         }
 876
 877         if (del_timer(&ct->timeout)) {
 878                 ct->timeout.function((unsigned long)ct);
 879                 return true;
 880         }
 881         return false;
 882 }
 883 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 884
 885 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 886
 887 #include <linux/netfilter/nfnetlink.h>
 888 #include <linux/netfilter/nfnetlink_conntrack.h>
 889 #include <linux/mutex.h>
 890
 891 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 892  * in ip_conntrack_core, since we don't want the protocols to autoload
 893  * or depend on ctnetlink */
 894 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 895                                const struct nf_conntrack_tuple *tuple)
 896 {
 897         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 898         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 899         return 0;
 900
 901 nla_put_failure:
 902         return -1;
 903 }
 904 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 905
 906 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 907         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 908         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 909 };
 910 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 911
 912 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 913                                struct nf_conntrack_tuple *t)
 914 {
 915         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 916                 return -EINVAL;
 917
 918         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 919         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 920
 921         return 0;
 922 }
 923 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 924 #endif
 925
 926 /* Used by ipt_REJECT and ip6t_REJECT. */
 927 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 928 {
 929         struct nf_conn *ct;
 930         enum ip_conntrack_info ctinfo;
 931
 932         /* This ICMP is in reverse direction to the packet which caused it */
 933         ct = nf_ct_get(skb, &ctinfo);
 934         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 935                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 936         else
 937                 ctinfo = IP_CT_RELATED;
 938
 939         /* Attach to new skbuff, and increment count */
 940         nskb->nfct = &ct->ct_general;
 941         nskb->nfctinfo = ctinfo;
 942         nf_conntrack_get(nskb->nfct);
 943 }
 944
 945 /* Bring out ya dead! */
 946 static struct nf_conn *
 947 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 948                 void *data, unsigned int *bucket)
 949 {
 950         struct nf_conntrack_tuple_hash *h;
 951         struct nf_conn *ct;
 952         struct hlist_node *n;
 953
 954         spin_lock_bh(&nf_conntrack_lock);
 955         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 956                 hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) {
 957                         ct = nf_ct_tuplehash_to_ctrack(h);
 958                         if (iter(ct, data))
 959                                 goto found;
 960                 }
 961         }
 962         hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) {
 963                 ct = nf_ct_tuplehash_to_ctrack(h);
 964                 if (iter(ct, data))
 965                         set_bit(IPS_DYING_BIT, &ct->status);
 966         }
 967         spin_unlock_bh(&nf_conntrack_lock);
 968         return NULL;
 969 found:
 970         atomic_inc(&ct->ct_general.use);
 971         spin_unlock_bh(&nf_conntrack_lock);
 972         return ct;
 973 }
 974
 975 void nf_ct_iterate_cleanup(struct net *net,
 976                            int (*iter)(struct nf_conn *i, void *data),
 977                            void *data)
 978 {
 979         struct nf_conn *ct;
 980         unsigned int bucket = 0;
 981
 982         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 983                 /* Time to push up daises... */
 984                 if (del_timer(&ct->timeout))
 985                         death_by_timeout((unsigned long)ct);
 986                 /* ... else the timer will get him soon. */
 987
 988                 nf_ct_put(ct);
 989         }
 990 }
 991 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 992
 993 static int kill_all(struct nf_conn *i, void *data)
 994 {
 995         return 1;
 996 }
 997
 998 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 999 {
1000         if (vmalloced)
1001                 vfree(hash);
1002         else
1003                 free_pages((unsigned long)hash,
1004                            get_order(sizeof(struct hlist_head) * size));
1005 }
1006 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1007
1008 void nf_conntrack_flush(struct net *net)
1009 {
1010         nf_ct_iterate_cleanup(net, kill_all, NULL);
1011 }
1012 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1013
1014 /* Mishearing the voices in his head, our hero wonders how he's
1015    supposed to kill the mall. */
1016 void nf_conntrack_cleanup(struct net *net)
1017 {
1018         rcu_assign_pointer(ip_ct_attach, NULL);
1019
1020         /* This makes sure all current packets have passed through
1021            netfilter framework.  Roll on, two-stage module
1022            delete... */
1023         synchronize_net();
1024
1025         nf_ct_event_cache_flush(net);
1026         nf_conntrack_ecache_fini(net);
1027  i_see_dead_people:
1028         nf_conntrack_flush(net);
1029         if (atomic_read(&net->ct.count) != 0) {
1030                 schedule();
1031                 goto i_see_dead_people;
1032         }
1033         /* wait until all references to nf_conntrack_untracked are dropped */
1034         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1035                 schedule();
1036
1037         rcu_assign_pointer(nf_ct_destroy, NULL);
1038
1039         kmem_cache_destroy(nf_conntrack_cachep);
1040         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1041                              nf_conntrack_htable_size);
1042
1043         nf_conntrack_acct_fini();
1044         nf_conntrack_expect_fini(net);
1045         free_percpu(net->ct.stat);
1046         nf_conntrack_helper_fini();
1047         nf_conntrack_proto_fini();
1048 }
1049
1050 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1051 {
1052         struct hlist_head *hash;
1053         unsigned int size, i;
1054
1055         *vmalloced = 0;
1056
1057         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1058         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1059                                        get_order(sizeof(struct hlist_head)
1060                                                  * size));
1061         if (!hash) {
1062                 *vmalloced = 1;
1063                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1064                 hash = vmalloc(sizeof(struct hlist_head) * size);
1065         }
1066
1067         if (hash)
1068                 for (i = 0; i < size; i++)
1069                         INIT_HLIST_HEAD(&hash[i]);
1070
1071         return hash;
1072 }
1073 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1074
1075 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1076 {
1077         int i, bucket, vmalloced, old_vmalloced;
1078         unsigned int hashsize, old_size;
1079         int rnd;
1080         struct hlist_head *hash, *old_hash;
1081         struct nf_conntrack_tuple_hash *h;
1082
1083         /* On boot, we can set this without any fancy locking. */
1084         if (!nf_conntrack_htable_size)
1085                 return param_set_uint(val, kp);
1086
1087         hashsize = simple_strtoul(val, NULL, 0);
1088         if (!hashsize)
1089                 return -EINVAL;
1090
1091         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1092         if (!hash)
1093                 return -ENOMEM;
1094
1095         /* We have to rehahs for the new table anyway, so we also can
1096          * use a newrandom seed */
1097         get_random_bytes(&rnd, 4);
1098
1099         /* Lookups in the old hash might happen in parallel, which means we
1100          * might get false negatives during connection lookup. New connections
1101          * created because of a false negative won't make it into the hash
1102          * though since that required taking the lock.
1103          */
1104         spin_lock_bh(&nf_conntrack_lock);
1105         for (i = 0; i < nf_conntrack_htable_size; i++) {
1106                 while (!hlist_empty(&init_net.ct.hash[i])) {
1107                         h = hlist_entry(init_net.ct.hash[i].first,
1108                                         struct nf_conntrack_tuple_hash, hnode);
1109                         hlist_del_rcu(&h->hnode);
1110                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1111                         hlist_add_head(&h->hnode, &hash[bucket]);
1112                 }
1113         }
1114         old_size = nf_conntrack_htable_size;
1115         old_vmalloced = init_net.ct.hash_vmalloc;
1116         old_hash = init_net.ct.hash;
1117
1118         nf_conntrack_htable_size = hashsize;
1119         init_net.ct.hash_vmalloc = vmalloced;
1120         init_net.ct.hash = hash;
1121         nf_conntrack_hash_rnd = rnd;
1122         spin_unlock_bh(&nf_conntrack_lock);
1123
1124         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1125         return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1128
1129 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1130                   &nf_conntrack_htable_size, 0600);
1131
1132 int nf_conntrack_init(struct net *net)
1133 {
1134         int max_factor = 8;
1135         int ret;
1136
1137         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1138          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1139         if (!nf_conntrack_htable_size) {
1140                 nf_conntrack_htable_size
1141                         = (((num_physpages << PAGE_SHIFT) / 16384)
1142                            / sizeof(struct hlist_head));
1143                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1144                         nf_conntrack_htable_size = 16384;
1145                 if (nf_conntrack_htable_size < 32)
1146                         nf_conntrack_htable_size = 32;
1147
1148                 /* Use a max. factor of four by default to get the same max as
1149                  * with the old struct list_heads. When a table size is given
1150                  * we use the old value of 8 to avoid reducing the max.
1151                  * entries. */
1152                 max_factor = 4;
1153         }
1154         atomic_set(&net->ct.count, 0);
1155         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1156         if (!net->ct.stat)
1157                 goto err_stat;
1158         ret = nf_conntrack_ecache_init(net);
1159         if (ret < 0)
1160                 goto err_ecache;
1161         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1162                                                   &net->ct.hash_vmalloc);
1163         if (!net->ct.hash) {
1164                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1165                 goto err_hash;
1166         }
1167         INIT_HLIST_HEAD(&net->ct.unconfirmed);
1168
1169         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1170
1171         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1172                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1173                nf_conntrack_max);
1174
1175         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1176                                                 sizeof(struct nf_conn),
1177                                                 0, 0, NULL);
1178         if (!nf_conntrack_cachep) {
1179                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1180                 goto err_free_hash;
1181         }
1182
1183         ret = nf_conntrack_proto_init();
1184         if (ret < 0)
1185                 goto err_free_conntrack_slab;
1186
1187         ret = nf_conntrack_expect_init(net);
1188         if (ret < 0)
1189                 goto out_fini_proto;
1190
1191         ret = nf_conntrack_helper_init();
1192         if (ret < 0)
1193                 goto out_fini_expect;
1194
1195         ret = nf_conntrack_acct_init();
1196         if (ret < 0)
1197                 goto out_fini_helper;
1198
1199         /* For use by REJECT target */
1200         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1201         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1202
1203         /* Set up fake conntrack:
1204             - to never be deleted, not in any hashes */
1205 #ifdef CONFIG_NET_NS
1206         nf_conntrack_untracked.ct_net = &init_net;
1207 #endif
1208         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1209         /*  - and look it like as a confirmed connection */
1210         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1211
1212         return ret;
1213
1214 out_fini_helper:
1215         nf_conntrack_helper_fini();
1216 out_fini_expect:
1217         nf_conntrack_expect_fini(net);
1218 out_fini_proto:
1219         nf_conntrack_proto_fini();
1220 err_free_conntrack_slab:
1221         kmem_cache_destroy(nf_conntrack_cachep);
1222 err_free_hash:
1223         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1224                              nf_conntrack_htable_size);
1225 err_hash:
1226         nf_conntrack_ecache_fini(net);
1227 err_ecache:
1228         free_percpu(net->ct.stat);
1229 err_stat:
1230         return -ENOMEM;
1231 }