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 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
  60 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
  61
  62 static int nf_conntrack_hash_rnd_initted;
  63 static unsigned int nf_conntrack_hash_rnd;
  64
  65 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  66                                   unsigned int size, unsigned int rnd)
  67 {
  68         unsigned int n;
  69         u_int32_t h;
  70
  71         /* The direction must be ignored, so we hash everything up to the
  72          * destination ports (which is a multiple of 4) and treat the last
  73          * three bytes manually.
  74          */
  75         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  76         h = jhash2((u32 *)tuple, n,
  77                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  78                           tuple->dst.protonum));
  79
  80         return ((u64)h * size) >> 32;
  81 }
  82
  83 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  84 {
  85         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  86                                 nf_conntrack_hash_rnd);
  87 }
  88
  89 bool
  90 nf_ct_get_tuple(const struct sk_buff *skb,
  91                 unsigned int nhoff,
  92                 unsigned int dataoff,
  93                 u_int16_t l3num,
  94                 u_int8_t protonum,
  95                 struct nf_conntrack_tuple *tuple,
  96                 const struct nf_conntrack_l3proto *l3proto,
  97                 const struct nf_conntrack_l4proto *l4proto)
  98 {
  99         memset(tuple, 0, sizeof(*tuple));
 100
 101         tuple->src.l3num = l3num;
 102         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 103                 return false;
 104
 105         tuple->dst.protonum = protonum;
 106         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 107
 108         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 109 }
 110 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 111
 112 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 113                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 114 {
 115         struct nf_conntrack_l3proto *l3proto;
 116         struct nf_conntrack_l4proto *l4proto;
 117         unsigned int protoff;
 118         u_int8_t protonum;
 119         int ret;
 120
 121         rcu_read_lock();
 122
 123         l3proto = __nf_ct_l3proto_find(l3num);
 124         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 125         if (ret != NF_ACCEPT) {
 126                 rcu_read_unlock();
 127                 return false;
 128         }
 129
 130         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 131
 132         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 133                               l3proto, l4proto);
 134
 135         rcu_read_unlock();
 136         return ret;
 137 }
 138 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 139
 140 bool
 141 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 142                    const struct nf_conntrack_tuple *orig,
 143                    const struct nf_conntrack_l3proto *l3proto,
 144                    const struct nf_conntrack_l4proto *l4proto)
 145 {
 146         memset(inverse, 0, sizeof(*inverse));
 147
 148         inverse->src.l3num = orig->src.l3num;
 149         if (l3proto->invert_tuple(inverse, orig) == 0)
 150                 return false;
 151
 152         inverse->dst.dir = !orig->dst.dir;
 153
 154         inverse->dst.protonum = orig->dst.protonum;
 155         return l4proto->invert_tuple(inverse, orig);
 156 }
 157 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 158
 159 static void
 160 clean_from_lists(struct nf_conn *ct)
 161 {
 162         pr_debug("clean_from_lists(%p)\n", ct);
 163         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 164         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 165
 166         /* Destroy all pending expectations */
 167         nf_ct_remove_expectations(ct);
 168 }
 169
 170 static void
 171 destroy_conntrack(struct nf_conntrack *nfct)
 172 {
 173         struct nf_conn *ct = (struct nf_conn *)nfct;
 174         struct nf_conntrack_l4proto *l4proto;
 175
 176         pr_debug("destroy_conntrack(%p)\n", ct);
 177         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 178         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 179
 180         nf_conntrack_event(IPCT_DESTROY, ct);
 181         set_bit(IPS_DYING_BIT, &ct->status);
 182
 183         /* To make sure we don't get any weird locking issues here:
 184          * destroy_conntrack() MUST NOT be called with a write lock
 185          * to nf_conntrack_lock!!! -HW */
 186         rcu_read_lock();
 187         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 188         if (l4proto && l4proto->destroy)
 189                 l4proto->destroy(ct);
 190
 191         rcu_read_unlock();
 192
 193         spin_lock_bh(&nf_conntrack_lock);
 194         /* Expectations will have been removed in clean_from_lists,
 195          * except TFTP can create an expectation on the first packet,
 196          * before connection is in the list, so we need to clean here,
 197          * too. */
 198         nf_ct_remove_expectations(ct);
 199
 200         /* We overload first tuple to link into unconfirmed list. */
 201         if (!nf_ct_is_confirmed(ct)) {
 202                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 203                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 204         }
 205
 206         NF_CT_STAT_INC(delete);
 207         spin_unlock_bh(&nf_conntrack_lock);
 208
 209         if (ct->master)
 210                 nf_ct_put(ct->master);
 211
 212         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 213         nf_conntrack_free(ct);
 214 }
 215
 216 static void death_by_timeout(unsigned long ul_conntrack)
 217 {
 218         struct nf_conn *ct = (void *)ul_conntrack;
 219         struct nf_conn_help *help = nfct_help(ct);
 220         struct nf_conntrack_helper *helper;
 221
 222         if (help) {
 223                 rcu_read_lock();
 224                 helper = rcu_dereference(help->helper);
 225                 if (helper && helper->destroy)
 226                         helper->destroy(ct);
 227                 rcu_read_unlock();
 228         }
 229
 230         spin_lock_bh(&nf_conntrack_lock);
 231         /* Inside lock so preempt is disabled on module removal path.
 232          * Otherwise we can get spurious warnings. */
 233         NF_CT_STAT_INC(delete_list);
 234         clean_from_lists(ct);
 235         spin_unlock_bh(&nf_conntrack_lock);
 236         nf_ct_put(ct);
 237 }
 238
 239 struct nf_conntrack_tuple_hash *
 240 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 241 {
 242         struct nf_conntrack_tuple_hash *h;
 243         struct hlist_node *n;
 244         unsigned int hash = hash_conntrack(tuple);
 245
 246         /* Disable BHs the entire time since we normally need to disable them
 247          * at least once for the stats anyway.
 248          */
 249         local_bh_disable();
 250         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 251                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 252                         NF_CT_STAT_INC(found);
 253                         local_bh_enable();
 254                         return h;
 255                 }
 256                 NF_CT_STAT_INC(searched);
 257         }
 258         local_bh_enable();
 259
 260         return NULL;
 261 }
 262 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 263
 264 /* Find a connection corresponding to a tuple. */
 265 struct nf_conntrack_tuple_hash *
 266 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 267 {
 268         struct nf_conntrack_tuple_hash *h;
 269         struct nf_conn *ct;
 270
 271         rcu_read_lock();
 272         h = __nf_conntrack_find(net, tuple);
 273         if (h) {
 274                 ct = nf_ct_tuplehash_to_ctrack(h);
 275                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 276                         h = NULL;
 277         }
 278         rcu_read_unlock();
 279
 280         return h;
 281 }
 282 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 283
 284 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 285                                        unsigned int hash,
 286                                        unsigned int repl_hash)
 287 {
 288         struct net *net = nf_ct_net(ct);
 289
 290         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 291                            &net->ct.hash[hash]);
 292         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 293                            &net->ct.hash[repl_hash]);
 294 }
 295
 296 void nf_conntrack_hash_insert(struct nf_conn *ct)
 297 {
 298         unsigned int hash, repl_hash;
 299
 300         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 301         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 302
 303         spin_lock_bh(&nf_conntrack_lock);
 304         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 305         spin_unlock_bh(&nf_conntrack_lock);
 306 }
 307 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 308
 309 /* Confirm a connection given skb; places it in hash table */
 310 int
 311 __nf_conntrack_confirm(struct sk_buff *skb)
 312 {
 313         unsigned int hash, repl_hash;
 314         struct nf_conntrack_tuple_hash *h;
 315         struct nf_conn *ct;
 316         struct nf_conn_help *help;
 317         struct hlist_node *n;
 318         enum ip_conntrack_info ctinfo;
 319         struct net *net;
 320
 321         ct = nf_ct_get(skb, &ctinfo);
 322         net = nf_ct_net(ct);
 323
 324         /* ipt_REJECT uses nf_conntrack_attach to attach related
 325            ICMP/TCP RST packets in other direction.  Actual packet
 326            which created connection will be IP_CT_NEW or for an
 327            expected connection, IP_CT_RELATED. */
 328         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 329                 return NF_ACCEPT;
 330
 331         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 332         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 333
 334         /* We're not in hash table, and we refuse to set up related
 335            connections for unconfirmed conns.  But packet copies and
 336            REJECT will give spurious warnings here. */
 337         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 338
 339         /* No external references means noone else could have
 340            confirmed us. */
 341         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 342         pr_debug("Confirming conntrack %p\n", ct);
 343
 344         spin_lock_bh(&nf_conntrack_lock);
 345
 346         /* See if there's one in the list already, including reverse:
 347            NAT could have grabbed it without realizing, since we're
 348            not in the hash.  If there is, we lost race. */
 349         hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode)
 350                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 351                                       &h->tuple))
 352                         goto out;
 353         hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode)
 354                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 355                                       &h->tuple))
 356                         goto out;
 357
 358         /* Remove from unconfirmed list */
 359         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 360
 361         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 362         /* Timer relative to confirmation time, not original
 363            setting time, otherwise we'd get timer wrap in
 364            weird delay cases. */
 365         ct->timeout.expires += jiffies;
 366         add_timer(&ct->timeout);
 367         atomic_inc(&ct->ct_general.use);
 368         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 369         NF_CT_STAT_INC(insert);
 370         spin_unlock_bh(&nf_conntrack_lock);
 371         help = nfct_help(ct);
 372         if (help && help->helper)
 373                 nf_conntrack_event_cache(IPCT_HELPER, skb);
 374 #ifdef CONFIG_NF_NAT_NEEDED
 375         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 376             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 377                 nf_conntrack_event_cache(IPCT_NATINFO, skb);
 378 #endif
 379         nf_conntrack_event_cache(master_ct(ct) ?
 380                                  IPCT_RELATED : IPCT_NEW, skb);
 381         return NF_ACCEPT;
 382
 383 out:
 384         NF_CT_STAT_INC(insert_failed);
 385         spin_unlock_bh(&nf_conntrack_lock);
 386         return NF_DROP;
 387 }
 388 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 389
 390 /* Returns true if a connection correspondings to the tuple (required
 391    for NAT). */
 392 int
 393 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 394                          const struct nf_conn *ignored_conntrack)
 395 {
 396         struct net *net = nf_ct_net(ignored_conntrack);
 397         struct nf_conntrack_tuple_hash *h;
 398         struct hlist_node *n;
 399         unsigned int hash = hash_conntrack(tuple);
 400
 401         /* Disable BHs the entire time since we need to disable them at
 402          * least once for the stats anyway.
 403          */
 404         rcu_read_lock_bh();
 405         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 406                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 407                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 408                         NF_CT_STAT_INC(found);
 409                         rcu_read_unlock_bh();
 410                         return 1;
 411                 }
 412                 NF_CT_STAT_INC(searched);
 413         }
 414         rcu_read_unlock_bh();
 415
 416         return 0;
 417 }
 418 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 419
 420 #define NF_CT_EVICTION_RANGE    8
 421
 422 /* There's a small race here where we may free a just-assured
 423    connection.  Too bad: we're in trouble anyway. */
 424 static noinline int early_drop(struct net *net, unsigned int hash)
 425 {
 426         /* Use oldest entry, which is roughly LRU */
 427         struct nf_conntrack_tuple_hash *h;
 428         struct nf_conn *ct = NULL, *tmp;
 429         struct hlist_node *n;
 430         unsigned int i, cnt = 0;
 431         int dropped = 0;
 432
 433         rcu_read_lock();
 434         for (i = 0; i < nf_conntrack_htable_size; i++) {
 435                 hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 436                                          hnode) {
 437                         tmp = nf_ct_tuplehash_to_ctrack(h);
 438                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 439                                 ct = tmp;
 440                         cnt++;
 441                 }
 442
 443                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 444                         ct = NULL;
 445                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 446                         break;
 447                 hash = (hash + 1) % nf_conntrack_htable_size;
 448         }
 449         rcu_read_unlock();
 450
 451         if (!ct)
 452                 return dropped;
 453
 454         if (del_timer(&ct->timeout)) {
 455                 death_by_timeout((unsigned long)ct);
 456                 dropped = 1;
 457                 NF_CT_STAT_INC_ATOMIC(early_drop);
 458         }
 459         nf_ct_put(ct);
 460         return dropped;
 461 }
 462
 463 struct nf_conn *nf_conntrack_alloc(struct net *net,
 464                                    const struct nf_conntrack_tuple *orig,
 465                                    const struct nf_conntrack_tuple *repl,
 466                                    gfp_t gfp)
 467 {
 468         struct nf_conn *ct = NULL;
 469
 470         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 471                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 472                 nf_conntrack_hash_rnd_initted = 1;
 473         }
 474
 475         /* We don't want any race condition at early drop stage */
 476         atomic_inc(&net->ct.count);
 477
 478         if (nf_conntrack_max &&
 479             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 480                 unsigned int hash = hash_conntrack(orig);
 481                 if (!early_drop(net, hash)) {
 482                         atomic_dec(&net->ct.count);
 483                         if (net_ratelimit())
 484                                 printk(KERN_WARNING
 485                                        "nf_conntrack: table full, dropping"
 486                                        " packet.\n");
 487                         return ERR_PTR(-ENOMEM);
 488                 }
 489         }
 490
 491         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 492         if (ct == NULL) {
 493                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 494                 atomic_dec(&net->ct.count);
 495                 return ERR_PTR(-ENOMEM);
 496         }
 497
 498         atomic_set(&ct->ct_general.use, 1);
 499         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 500         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 501         /* Don't set timer yet: wait for confirmation */
 502         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 503 #ifdef CONFIG_NET_NS
 504         ct->ct_net = net;
 505 #endif
 506         INIT_RCU_HEAD(&ct->rcu);
 507
 508         return ct;
 509 }
 510 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 511
 512 static void nf_conntrack_free_rcu(struct rcu_head *head)
 513 {
 514         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 515         struct net *net = nf_ct_net(ct);
 516
 517         nf_ct_ext_free(ct);
 518         kmem_cache_free(nf_conntrack_cachep, ct);
 519         atomic_dec(&net->ct.count);
 520 }
 521
 522 void nf_conntrack_free(struct nf_conn *ct)
 523 {
 524         nf_ct_ext_destroy(ct);
 525         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 526 }
 527 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 528
 529 /* Allocate a new conntrack: we return -ENOMEM if classification
 530    failed due to stress.  Otherwise it really is unclassifiable. */
 531 static struct nf_conntrack_tuple_hash *
 532 init_conntrack(struct net *net,
 533                const struct nf_conntrack_tuple *tuple,
 534                struct nf_conntrack_l3proto *l3proto,
 535                struct nf_conntrack_l4proto *l4proto,
 536                struct sk_buff *skb,
 537                unsigned int dataoff)
 538 {
 539         struct nf_conn *ct;
 540         struct nf_conn_help *help;
 541         struct nf_conntrack_tuple repl_tuple;
 542         struct nf_conntrack_expect *exp;
 543
 544         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 545                 pr_debug("Can't invert tuple.\n");
 546                 return NULL;
 547         }
 548
 549         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 550         if (ct == NULL || IS_ERR(ct)) {
 551                 pr_debug("Can't allocate conntrack.\n");
 552                 return (struct nf_conntrack_tuple_hash *)ct;
 553         }
 554
 555         if (!l4proto->new(ct, skb, dataoff)) {
 556                 nf_conntrack_free(ct);
 557                 pr_debug("init conntrack: can't track with proto module\n");
 558                 return NULL;
 559         }
 560
 561         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 562
 563         spin_lock_bh(&nf_conntrack_lock);
 564         exp = nf_ct_find_expectation(net, tuple);
 565         if (exp) {
 566                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 567                          ct, exp);
 568                 /* Welcome, Mr. Bond.  We've been expecting you... */
 569                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 570                 ct->master = exp->master;
 571                 if (exp->helper) {
 572                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 573                         if (help)
 574                                 rcu_assign_pointer(help->helper, exp->helper);
 575                 }
 576
 577 #ifdef CONFIG_NF_CONNTRACK_MARK
 578                 ct->mark = exp->master->mark;
 579 #endif
 580 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 581                 ct->secmark = exp->master->secmark;
 582 #endif
 583                 nf_conntrack_get(&ct->master->ct_general);
 584                 NF_CT_STAT_INC(expect_new);
 585         } else {
 586                 struct nf_conntrack_helper *helper;
 587
 588                 helper = __nf_ct_helper_find(&repl_tuple);
 589                 if (helper) {
 590                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 591                         if (help)
 592                                 rcu_assign_pointer(help->helper, helper);
 593                 }
 594                 NF_CT_STAT_INC(new);
 595         }
 596
 597         /* Overload tuple linked list to put us in unconfirmed list. */
 598         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 599                        &net->ct.unconfirmed);
 600
 601         spin_unlock_bh(&nf_conntrack_lock);
 602
 603         if (exp) {
 604                 if (exp->expectfn)
 605                         exp->expectfn(ct, exp);
 606                 nf_ct_expect_put(exp);
 607         }
 608
 609         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 610 }
 611
 612 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 613 static inline struct nf_conn *
 614 resolve_normal_ct(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(&init_net, &tuple);
 636         if (!h) {
 637                 h = init_conntrack(&init_net, &tuple, l3proto, l4proto, skb,
 638                                    dataoff);
 639                 if (!h)
 640                         return NULL;
 641                 if (IS_ERR(h))
 642                         return (void *)h;
 643         }
 644         ct = nf_ct_tuplehash_to_ctrack(h);
 645
 646         /* It exists; we have (non-exclusive) reference. */
 647         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 648                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 649                 /* Please set reply bit if this packet OK */
 650                 *set_reply = 1;
 651         } else {
 652                 /* Once we've had two way comms, always ESTABLISHED. */
 653                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 654                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 655                         *ctinfo = IP_CT_ESTABLISHED;
 656                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 657                         pr_debug("nf_conntrack_in: related packet for %p\n",
 658                                  ct);
 659                         *ctinfo = IP_CT_RELATED;
 660                 } else {
 661                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 662                         *ctinfo = IP_CT_NEW;
 663                 }
 664                 *set_reply = 0;
 665         }
 666         skb->nfct = &ct->ct_general;
 667         skb->nfctinfo = *ctinfo;
 668         return ct;
 669 }
 670
 671 unsigned int
 672 nf_conntrack_in(u_int8_t pf, unsigned int hooknum, 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(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(error);
 696                 NF_CT_STAT_INC_ATOMIC(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(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
 707                 NF_CT_STAT_INC_ATOMIC(error);
 708                 NF_CT_STAT_INC_ATOMIC(invalid);
 709                 return -ret;
 710         }
 711
 712         ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
 713                                &set_reply, &ctinfo);
 714         if (!ct) {
 715                 /* Not valid part of a connection */
 716                 NF_CT_STAT_INC_ATOMIC(invalid);
 717                 return NF_ACCEPT;
 718         }
 719
 720         if (IS_ERR(ct)) {
 721                 /* Too stressed to deal. */
 722                 NF_CT_STAT_INC_ATOMIC(drop);
 723                 return NF_DROP;
 724         }
 725
 726         NF_CT_ASSERT(skb->nfct);
 727
 728         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 729         if (ret < 0) {
 730                 /* Invalid: inverse of the return code tells
 731                  * the netfilter core what to do */
 732                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 733                 nf_conntrack_put(skb->nfct);
 734                 skb->nfct = NULL;
 735                 NF_CT_STAT_INC_ATOMIC(invalid);
 736                 return -ret;
 737         }
 738
 739         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 740                 nf_conntrack_event_cache(IPCT_STATUS, skb);
 741
 742         return ret;
 743 }
 744 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 745
 746 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 747                           const struct nf_conntrack_tuple *orig)
 748 {
 749         bool ret;
 750
 751         rcu_read_lock();
 752         ret = nf_ct_invert_tuple(inverse, orig,
 753                                  __nf_ct_l3proto_find(orig->src.l3num),
 754                                  __nf_ct_l4proto_find(orig->src.l3num,
 755                                                       orig->dst.protonum));
 756         rcu_read_unlock();
 757         return ret;
 758 }
 759 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 760
 761 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 762    implicitly racy: see __nf_conntrack_confirm */
 763 void nf_conntrack_alter_reply(struct nf_conn *ct,
 764                               const struct nf_conntrack_tuple *newreply)
 765 {
 766         struct nf_conn_help *help = nfct_help(ct);
 767         struct nf_conntrack_helper *helper;
 768
 769         /* Should be unconfirmed, so not in hash table yet */
 770         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 771
 772         pr_debug("Altering reply tuple of %p to ", ct);
 773         nf_ct_dump_tuple(newreply);
 774
 775         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 776         if (ct->master || (help && !hlist_empty(&help->expectations)))
 777                 return;
 778
 779         rcu_read_lock();
 780         helper = __nf_ct_helper_find(newreply);
 781         if (helper == NULL) {
 782                 if (help)
 783                         rcu_assign_pointer(help->helper, NULL);
 784                 goto out;
 785         }
 786
 787         if (help == NULL) {
 788                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 789                 if (help == NULL)
 790                         goto out;
 791         } else {
 792                 memset(&help->help, 0, sizeof(help->help));
 793         }
 794
 795         rcu_assign_pointer(help->helper, helper);
 796 out:
 797         rcu_read_unlock();
 798 }
 799 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 800
 801 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 802 void __nf_ct_refresh_acct(struct nf_conn *ct,
 803                           enum ip_conntrack_info ctinfo,
 804                           const struct sk_buff *skb,
 805                           unsigned long extra_jiffies,
 806                           int do_acct)
 807 {
 808         int event = 0;
 809
 810         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 811         NF_CT_ASSERT(skb);
 812
 813         spin_lock_bh(&nf_conntrack_lock);
 814
 815         /* Only update if this is not a fixed timeout */
 816         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 817                 goto acct;
 818
 819         /* If not in hash table, timer will not be active yet */
 820         if (!nf_ct_is_confirmed(ct)) {
 821                 ct->timeout.expires = extra_jiffies;
 822                 event = IPCT_REFRESH;
 823         } else {
 824                 unsigned long newtime = jiffies + extra_jiffies;
 825
 826                 /* Only update the timeout if the new timeout is at least
 827                    HZ jiffies from the old timeout. Need del_timer for race
 828                    avoidance (may already be dying). */
 829                 if (newtime - ct->timeout.expires >= HZ
 830                     && del_timer(&ct->timeout)) {
 831                         ct->timeout.expires = newtime;
 832                         add_timer(&ct->timeout);
 833                         event = IPCT_REFRESH;
 834                 }
 835         }
 836
 837 acct:
 838         if (do_acct) {
 839                 struct nf_conn_counter *acct;
 840
 841                 acct = nf_conn_acct_find(ct);
 842                 if (acct) {
 843                         acct[CTINFO2DIR(ctinfo)].packets++;
 844                         acct[CTINFO2DIR(ctinfo)].bytes +=
 845                                 skb->len - skb_network_offset(skb);
 846                 }
 847         }
 848
 849         spin_unlock_bh(&nf_conntrack_lock);
 850
 851         /* must be unlocked when calling event cache */
 852         if (event)
 853                 nf_conntrack_event_cache(event, skb);
 854 }
 855 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 856
 857 bool __nf_ct_kill_acct(struct nf_conn *ct,
 858                        enum ip_conntrack_info ctinfo,
 859                        const struct sk_buff *skb,
 860                        int do_acct)
 861 {
 862         if (do_acct) {
 863                 struct nf_conn_counter *acct;
 864
 865                 spin_lock_bh(&nf_conntrack_lock);
 866                 acct = nf_conn_acct_find(ct);
 867                 if (acct) {
 868                         acct[CTINFO2DIR(ctinfo)].packets++;
 869                         acct[CTINFO2DIR(ctinfo)].bytes +=
 870                                 skb->len - skb_network_offset(skb);
 871                 }
 872                 spin_unlock_bh(&nf_conntrack_lock);
 873         }
 874
 875         if (del_timer(&ct->timeout)) {
 876                 ct->timeout.function((unsigned long)ct);
 877                 return true;
 878         }
 879         return false;
 880 }
 881 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 882
 883 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 884
 885 #include <linux/netfilter/nfnetlink.h>
 886 #include <linux/netfilter/nfnetlink_conntrack.h>
 887 #include <linux/mutex.h>
 888
 889 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 890  * in ip_conntrack_core, since we don't want the protocols to autoload
 891  * or depend on ctnetlink */
 892 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 893                                const struct nf_conntrack_tuple *tuple)
 894 {
 895         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 896         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 897         return 0;
 898
 899 nla_put_failure:
 900         return -1;
 901 }
 902 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 903
 904 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 905         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 906         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 907 };
 908 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 909
 910 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 911                                struct nf_conntrack_tuple *t)
 912 {
 913         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 914                 return -EINVAL;
 915
 916         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 917         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 918
 919         return 0;
 920 }
 921 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 922 #endif
 923
 924 /* Used by ipt_REJECT and ip6t_REJECT. */
 925 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 926 {
 927         struct nf_conn *ct;
 928         enum ip_conntrack_info ctinfo;
 929
 930         /* This ICMP is in reverse direction to the packet which caused it */
 931         ct = nf_ct_get(skb, &ctinfo);
 932         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 933                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 934         else
 935                 ctinfo = IP_CT_RELATED;
 936
 937         /* Attach to new skbuff, and increment count */
 938         nskb->nfct = &ct->ct_general;
 939         nskb->nfctinfo = ctinfo;
 940         nf_conntrack_get(nskb->nfct);
 941 }
 942
 943 /* Bring out ya dead! */
 944 static struct nf_conn *
 945 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 946                 void *data, unsigned int *bucket)
 947 {
 948         struct nf_conntrack_tuple_hash *h;
 949         struct nf_conn *ct;
 950         struct hlist_node *n;
 951
 952         spin_lock_bh(&nf_conntrack_lock);
 953         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 954                 hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) {
 955                         ct = nf_ct_tuplehash_to_ctrack(h);
 956                         if (iter(ct, data))
 957                                 goto found;
 958                 }
 959         }
 960         hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) {
 961                 ct = nf_ct_tuplehash_to_ctrack(h);
 962                 if (iter(ct, data))
 963                         set_bit(IPS_DYING_BIT, &ct->status);
 964         }
 965         spin_unlock_bh(&nf_conntrack_lock);
 966         return NULL;
 967 found:
 968         atomic_inc(&ct->ct_general.use);
 969         spin_unlock_bh(&nf_conntrack_lock);
 970         return ct;
 971 }
 972
 973 void nf_ct_iterate_cleanup(struct net *net,
 974                            int (*iter)(struct nf_conn *i, void *data),
 975                            void *data)
 976 {
 977         struct nf_conn *ct;
 978         unsigned int bucket = 0;
 979
 980         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 981                 /* Time to push up daises... */
 982                 if (del_timer(&ct->timeout))
 983                         death_by_timeout((unsigned long)ct);
 984                 /* ... else the timer will get him soon. */
 985
 986                 nf_ct_put(ct);
 987         }
 988 }
 989 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 990
 991 static int kill_all(struct nf_conn *i, void *data)
 992 {
 993         return 1;
 994 }
 995
 996 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 997 {
 998         if (vmalloced)
 999                 vfree(hash);
1000         else
1001                 free_pages((unsigned long)hash,
1002                            get_order(sizeof(struct hlist_head) * size));
1003 }
1004 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1005
1006 void nf_conntrack_flush(struct net *net)
1007 {
1008         nf_ct_iterate_cleanup(net, kill_all, NULL);
1009 }
1010 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1011
1012 /* Mishearing the voices in his head, our hero wonders how he's
1013    supposed to kill the mall. */
1014 void nf_conntrack_cleanup(struct net *net)
1015 {
1016         rcu_assign_pointer(ip_ct_attach, NULL);
1017
1018         /* This makes sure all current packets have passed through
1019            netfilter framework.  Roll on, two-stage module
1020            delete... */
1021         synchronize_net();
1022
1023         nf_ct_event_cache_flush();
1024  i_see_dead_people:
1025         nf_conntrack_flush(net);
1026         if (atomic_read(&net->ct.count) != 0) {
1027                 schedule();
1028                 goto i_see_dead_people;
1029         }
1030         /* wait until all references to nf_conntrack_untracked are dropped */
1031         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1032                 schedule();
1033
1034         rcu_assign_pointer(nf_ct_destroy, NULL);
1035
1036         kmem_cache_destroy(nf_conntrack_cachep);
1037         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1038                              nf_conntrack_htable_size);
1039
1040         nf_conntrack_acct_fini();
1041         nf_conntrack_expect_fini(net);
1042         nf_conntrack_helper_fini();
1043         nf_conntrack_proto_fini();
1044 }
1045
1046 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1047 {
1048         struct hlist_head *hash;
1049         unsigned int size, i;
1050
1051         *vmalloced = 0;
1052
1053         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1054         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1055                                        get_order(sizeof(struct hlist_head)
1056                                                  * size));
1057         if (!hash) {
1058                 *vmalloced = 1;
1059                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1060                 hash = vmalloc(sizeof(struct hlist_head) * size);
1061         }
1062
1063         if (hash)
1064                 for (i = 0; i < size; i++)
1065                         INIT_HLIST_HEAD(&hash[i]);
1066
1067         return hash;
1068 }
1069 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1070
1071 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1072 {
1073         int i, bucket, vmalloced, old_vmalloced;
1074         unsigned int hashsize, old_size;
1075         int rnd;
1076         struct hlist_head *hash, *old_hash;
1077         struct nf_conntrack_tuple_hash *h;
1078
1079         /* On boot, we can set this without any fancy locking. */
1080         if (!nf_conntrack_htable_size)
1081                 return param_set_uint(val, kp);
1082
1083         hashsize = simple_strtoul(val, NULL, 0);
1084         if (!hashsize)
1085                 return -EINVAL;
1086
1087         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1088         if (!hash)
1089                 return -ENOMEM;
1090
1091         /* We have to rehahs for the new table anyway, so we also can
1092          * use a newrandom seed */
1093         get_random_bytes(&rnd, 4);
1094
1095         /* Lookups in the old hash might happen in parallel, which means we
1096          * might get false negatives during connection lookup. New connections
1097          * created because of a false negative won't make it into the hash
1098          * though since that required taking the lock.
1099          */
1100         spin_lock_bh(&nf_conntrack_lock);
1101         for (i = 0; i < nf_conntrack_htable_size; i++) {
1102                 while (!hlist_empty(&init_net.ct.hash[i])) {
1103                         h = hlist_entry(init_net.ct.hash[i].first,
1104                                         struct nf_conntrack_tuple_hash, hnode);
1105                         hlist_del_rcu(&h->hnode);
1106                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1107                         hlist_add_head(&h->hnode, &hash[bucket]);
1108                 }
1109         }
1110         old_size = nf_conntrack_htable_size;
1111         old_vmalloced = init_net.ct.hash_vmalloc;
1112         old_hash = init_net.ct.hash;
1113
1114         nf_conntrack_htable_size = hashsize;
1115         init_net.ct.hash_vmalloc = vmalloced;
1116         init_net.ct.hash = hash;
1117         nf_conntrack_hash_rnd = rnd;
1118         spin_unlock_bh(&nf_conntrack_lock);
1119
1120         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1121         return 0;
1122 }
1123 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1124
1125 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1126                   &nf_conntrack_htable_size, 0600);
1127
1128 int nf_conntrack_init(struct net *net)
1129 {
1130         int max_factor = 8;
1131         int ret;
1132
1133         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1134          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1135         if (!nf_conntrack_htable_size) {
1136                 nf_conntrack_htable_size
1137                         = (((num_physpages << PAGE_SHIFT) / 16384)
1138                            / sizeof(struct hlist_head));
1139                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1140                         nf_conntrack_htable_size = 16384;
1141                 if (nf_conntrack_htable_size < 32)
1142                         nf_conntrack_htable_size = 32;
1143
1144                 /* Use a max. factor of four by default to get the same max as
1145                  * with the old struct list_heads. When a table size is given
1146                  * we use the old value of 8 to avoid reducing the max.
1147                  * entries. */
1148                 max_factor = 4;
1149         }
1150         atomic_set(&net->ct.count, 0);
1151         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1152                                                   &net->ct.hash_vmalloc);
1153         if (!net->ct.hash) {
1154                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1155                 goto err_out;
1156         }
1157         INIT_HLIST_HEAD(&net->ct.unconfirmed);
1158
1159         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1160
1161         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1162                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1163                nf_conntrack_max);
1164
1165         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1166                                                 sizeof(struct nf_conn),
1167                                                 0, 0, NULL);
1168         if (!nf_conntrack_cachep) {
1169                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1170                 goto err_free_hash;
1171         }
1172
1173         ret = nf_conntrack_proto_init();
1174         if (ret < 0)
1175                 goto err_free_conntrack_slab;
1176
1177         ret = nf_conntrack_expect_init(net);
1178         if (ret < 0)
1179                 goto out_fini_proto;
1180
1181         ret = nf_conntrack_helper_init();
1182         if (ret < 0)
1183                 goto out_fini_expect;
1184
1185         ret = nf_conntrack_acct_init();
1186         if (ret < 0)
1187                 goto out_fini_helper;
1188
1189         /* For use by REJECT target */
1190         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1191         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1192
1193         /* Set up fake conntrack:
1194             - to never be deleted, not in any hashes */
1195 #ifdef CONFIG_NET_NS
1196         nf_conntrack_untracked.ct_net = &init_net;
1197 #endif
1198         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1199         /*  - and look it like as a confirmed connection */
1200         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1201
1202         return ret;
1203
1204 out_fini_helper:
1205         nf_conntrack_helper_fini();
1206 out_fini_expect:
1207         nf_conntrack_expect_fini(net);
1208 out_fini_proto:
1209         nf_conntrack_proto_fini();
1210 err_free_conntrack_slab:
1211         kmem_cache_destroy(nf_conntrack_cachep);
1212 err_free_hash:
1213         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1214                              nf_conntrack_htable_size);
1215 err_out:
1216         return -ENOMEM;
1217 }