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