SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/netfilter/nf_conntrack_core.c

   1 /* Connection state tracking for netfilter.  This is separated from,
   2    but required by, the NAT layer; it can also be used by an iptables
   3    extension. */
   4
   5 /* (C) 1999-2001 Paul `Rusty' Russell
   6  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
   7  * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/netfilter.h>
  16 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/proc_fs.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/stddef.h>
  21 #include <linux/slab.h>
  22 #include <linux/random.h>
  23 #include <linux/jhash.h>
  24 #include <linux/err.h>
  25 #include <linux/percpu.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/notifier.h>
  28 #include <linux/kernel.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/socket.h>
  31 #include <linux/mm.h>
  32
  33 #include <net/netfilter/nf_conntrack.h>
  34 #include <net/netfilter/nf_conntrack_l3proto.h>
  35 #include <net/netfilter/nf_conntrack_l4proto.h>
  36 #include <net/netfilter/nf_conntrack_expect.h>
  37 #include <net/netfilter/nf_conntrack_helper.h>
  38 #include <net/netfilter/nf_conntrack_core.h>
  39 #include <net/netfilter/nf_conntrack_extend.h>
  40 #include <net/netfilter/nf_conntrack_acct.h>
  41
  42 #define NF_CONNTRACK_VERSION    "0.5.0"
  43
  44 DEFINE_SPINLOCK(nf_conntrack_lock);
  45 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  46
  47 unsigned int nf_conntrack_htable_size __read_mostly;
  48 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
  49
  50 int nf_conntrack_max __read_mostly;
  51 EXPORT_SYMBOL_GPL(nf_conntrack_max);
  52
  53 struct nf_conn nf_conntrack_untracked __read_mostly;
  54 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
  55
  56 unsigned int nf_ct_log_invalid __read_mostly;
  57 HLIST_HEAD(unconfirmed);
  58 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  59
  60 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
  61 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
  62
  63 static int nf_conntrack_hash_rnd_initted;
  64 static unsigned int nf_conntrack_hash_rnd;
  65
  66 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  67                                   unsigned int size, unsigned int rnd)
  68 {
  69         unsigned int n;
  70         u_int32_t h;
  71
  72         /* The direction must be ignored, so we hash everything up to the
  73          * destination ports (which is a multiple of 4) and treat the last
  74          * three bytes manually.
  75          */
  76         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  77         h = jhash2((u32 *)tuple, n,
  78                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  79                           tuple->dst.protonum));
  80
  81         return ((u64)h * size) >> 32;
  82 }
  83
  84 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  85 {
  86         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  87                                 nf_conntrack_hash_rnd);
  88 }
  89
  90 bool
  91 nf_ct_get_tuple(const struct sk_buff *skb,
  92                 unsigned int nhoff,
  93                 unsigned int dataoff,
  94                 u_int16_t l3num,
  95                 u_int8_t protonum,
  96                 struct nf_conntrack_tuple *tuple,
  97                 const struct nf_conntrack_l3proto *l3proto,
  98                 const struct nf_conntrack_l4proto *l4proto)
  99 {
 100         memset(tuple, 0, sizeof(*tuple));
 101
 102         tuple->src.l3num = l3num;
 103         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 104                 return false;
 105
 106         tuple->dst.protonum = protonum;
 107         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 108
 109         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 110 }
 111 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 112
 113 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 114                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 115 {
 116         struct nf_conntrack_l3proto *l3proto;
 117         struct nf_conntrack_l4proto *l4proto;
 118         unsigned int protoff;
 119         u_int8_t protonum;
 120         int ret;
 121
 122         rcu_read_lock();
 123
 124         l3proto = __nf_ct_l3proto_find(l3num);
 125         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 126         if (ret != NF_ACCEPT) {
 127                 rcu_read_unlock();
 128                 return false;
 129         }
 130
 131         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 132
 133         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 134                               l3proto, l4proto);
 135
 136         rcu_read_unlock();
 137         return ret;
 138 }
 139 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 140
 141 bool
 142 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 143                    const struct nf_conntrack_tuple *orig,
 144                    const struct nf_conntrack_l3proto *l3proto,
 145                    const struct nf_conntrack_l4proto *l4proto)
 146 {
 147         memset(inverse, 0, sizeof(*inverse));
 148
 149         inverse->src.l3num = orig->src.l3num;
 150         if (l3proto->invert_tuple(inverse, orig) == 0)
 151                 return false;
 152
 153         inverse->dst.dir = !orig->dst.dir;
 154
 155         inverse->dst.protonum = orig->dst.protonum;
 156         return l4proto->invert_tuple(inverse, orig);
 157 }
 158 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 159
 160 static void
 161 clean_from_lists(struct nf_conn *ct)
 162 {
 163         pr_debug("clean_from_lists(%p)\n", ct);
 164         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 165         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 166
 167         /* Destroy all pending expectations */
 168         nf_ct_remove_expectations(ct);
 169 }
 170
 171 static void
 172 destroy_conntrack(struct nf_conntrack *nfct)
 173 {
 174         struct nf_conn *ct = (struct nf_conn *)nfct;
 175         struct nf_conntrack_l4proto *l4proto;
 176
 177         pr_debug("destroy_conntrack(%p)\n", ct);
 178         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 179         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 180
 181         nf_conntrack_event(IPCT_DESTROY, ct);
 182         set_bit(IPS_DYING_BIT, &ct->status);
 183
 184         /* To make sure we don't get any weird locking issues here:
 185          * destroy_conntrack() MUST NOT be called with a write lock
 186          * to nf_conntrack_lock!!! -HW */
 187         rcu_read_lock();
 188         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 189         if (l4proto && l4proto->destroy)
 190                 l4proto->destroy(ct);
 191
 192         rcu_read_unlock();
 193
 194         spin_lock_bh(&nf_conntrack_lock);
 195         /* Expectations will have been removed in clean_from_lists,
 196          * except TFTP can create an expectation on the first packet,
 197          * before connection is in the list, so we need to clean here,
 198          * too. */
 199         nf_ct_remove_expectations(ct);
 200
 201         /* We overload first tuple to link into unconfirmed list. */
 202         if (!nf_ct_is_confirmed(ct)) {
 203                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 204                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 205         }
 206
 207         NF_CT_STAT_INC(delete);
 208         spin_unlock_bh(&nf_conntrack_lock);
 209
 210         if (ct->master)
 211                 nf_ct_put(ct->master);
 212
 213         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 214         nf_conntrack_free(ct);
 215 }
 216
 217 static void death_by_timeout(unsigned long ul_conntrack)
 218 {
 219         struct nf_conn *ct = (void *)ul_conntrack;
 220         struct nf_conn_help *help = nfct_help(ct);
 221         struct nf_conntrack_helper *helper;
 222
 223         if (help) {
 224                 rcu_read_lock();
 225                 helper = rcu_dereference(help->helper);
 226                 if (helper && helper->destroy)
 227                         helper->destroy(ct);
 228                 rcu_read_unlock();
 229         }
 230
 231         spin_lock_bh(&nf_conntrack_lock);
 232         /* Inside lock so preempt is disabled on module removal path.
 233          * Otherwise we can get spurious warnings. */
 234         NF_CT_STAT_INC(delete_list);
 235         clean_from_lists(ct);
 236         spin_unlock_bh(&nf_conntrack_lock);
 237         nf_ct_put(ct);
 238 }
 239
 240 struct nf_conntrack_tuple_hash *
 241 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 242 {
 243         struct nf_conntrack_tuple_hash *h;
 244         struct hlist_node *n;
 245         unsigned int hash = hash_conntrack(tuple);
 246
 247         /* Disable BHs the entire time since we normally need to disable them
 248          * at least once for the stats anyway.
 249          */
 250         local_bh_disable();
 251         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 252                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 253                         NF_CT_STAT_INC(found);
 254                         local_bh_enable();
 255                         return h;
 256                 }
 257                 NF_CT_STAT_INC(searched);
 258         }
 259         local_bh_enable();
 260
 261         return NULL;
 262 }
 263 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 264
 265 /* Find a connection corresponding to a tuple. */
 266 struct nf_conntrack_tuple_hash *
 267 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 268 {
 269         struct nf_conntrack_tuple_hash *h;
 270         struct nf_conn *ct;
 271
 272         rcu_read_lock();
 273         h = __nf_conntrack_find(net, tuple);
 274         if (h) {
 275                 ct = nf_ct_tuplehash_to_ctrack(h);
 276                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 277                         h = NULL;
 278         }
 279         rcu_read_unlock();
 280
 281         return h;
 282 }
 283 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 284
 285 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 286                                        unsigned int hash,
 287                                        unsigned int repl_hash)
 288 {
 289         struct net *net = nf_ct_net(ct);
 290
 291         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 292                            &net->ct.hash[hash]);
 293         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 294                            &net->ct.hash[repl_hash]);
 295 }
 296
 297 void nf_conntrack_hash_insert(struct nf_conn *ct)
 298 {
 299         unsigned int hash, repl_hash;
 300
 301         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 302         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 303
 304         spin_lock_bh(&nf_conntrack_lock);
 305         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 306         spin_unlock_bh(&nf_conntrack_lock);
 307 }
 308 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 309
 310 /* Confirm a connection given skb; places it in hash table */
 311 int
 312 __nf_conntrack_confirm(struct sk_buff *skb)
 313 {
 314         unsigned int hash, repl_hash;
 315         struct nf_conntrack_tuple_hash *h;
 316         struct nf_conn *ct;
 317         struct nf_conn_help *help;
 318         struct hlist_node *n;
 319         enum ip_conntrack_info ctinfo;
 320         struct net *net;
 321
 322         ct = nf_ct_get(skb, &ctinfo);
 323         net = nf_ct_net(ct);
 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, &net->ct.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, &net->ct.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 net *net = nf_ct_net(ignored_conntrack);
 398         struct nf_conntrack_tuple_hash *h;
 399         struct hlist_node *n;
 400         unsigned int hash = hash_conntrack(tuple);
 401
 402         /* Disable BHs the entire time since we need to disable them at
 403          * least once for the stats anyway.
 404          */
 405         rcu_read_lock_bh();
 406         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 407                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 408                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 409                         NF_CT_STAT_INC(found);
 410                         rcu_read_unlock_bh();
 411                         return 1;
 412                 }
 413                 NF_CT_STAT_INC(searched);
 414         }
 415         rcu_read_unlock_bh();
 416
 417         return 0;
 418 }
 419 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 420
 421 #define NF_CT_EVICTION_RANGE    8
 422
 423 /* There's a small race here where we may free a just-assured
 424    connection.  Too bad: we're in trouble anyway. */
 425 static noinline int early_drop(struct net *net, unsigned int hash)
 426 {
 427         /* Use oldest entry, which is roughly LRU */
 428         struct nf_conntrack_tuple_hash *h;
 429         struct nf_conn *ct = NULL, *tmp;
 430         struct hlist_node *n;
 431         unsigned int i, cnt = 0;
 432         int dropped = 0;
 433
 434         rcu_read_lock();
 435         for (i = 0; i < nf_conntrack_htable_size; i++) {
 436                 hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 437                                          hnode) {
 438                         tmp = nf_ct_tuplehash_to_ctrack(h);
 439                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 440                                 ct = tmp;
 441                         cnt++;
 442                 }
 443
 444                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 445                         ct = NULL;
 446                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 447                         break;
 448                 hash = (hash + 1) % nf_conntrack_htable_size;
 449         }
 450         rcu_read_unlock();
 451
 452         if (!ct)
 453                 return dropped;
 454
 455         if (del_timer(&ct->timeout)) {
 456                 death_by_timeout((unsigned long)ct);
 457                 dropped = 1;
 458                 NF_CT_STAT_INC_ATOMIC(early_drop);
 459         }
 460         nf_ct_put(ct);
 461         return dropped;
 462 }
 463
 464 struct nf_conn *nf_conntrack_alloc(struct net *net,
 465                                    const struct nf_conntrack_tuple *orig,
 466                                    const struct nf_conntrack_tuple *repl,
 467                                    gfp_t gfp)
 468 {
 469         struct nf_conn *ct = NULL;
 470
 471         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 472                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 473                 nf_conntrack_hash_rnd_initted = 1;
 474         }
 475
 476         /* We don't want any race condition at early drop stage */
 477         atomic_inc(&net->ct.count);
 478
 479         if (nf_conntrack_max &&
 480             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 481                 unsigned int hash = hash_conntrack(orig);
 482                 if (!early_drop(net, hash)) {
 483                         atomic_dec(&net->ct.count);
 484                         if (net_ratelimit())
 485                                 printk(KERN_WARNING
 486                                        "nf_conntrack: table full, dropping"
 487                                        " packet.\n");
 488                         return ERR_PTR(-ENOMEM);
 489                 }
 490         }
 491
 492         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 493         if (ct == NULL) {
 494                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 495                 atomic_dec(&net->ct.count);
 496                 return ERR_PTR(-ENOMEM);
 497         }
 498
 499         atomic_set(&ct->ct_general.use, 1);
 500         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 501         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 502         /* Don't set timer yet: wait for confirmation */
 503         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 504 #ifdef CONFIG_NET_NS
 505         ct->ct_net = net;
 506 #endif
 507         INIT_RCU_HEAD(&ct->rcu);
 508
 509         return ct;
 510 }
 511 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 512
 513 static void nf_conntrack_free_rcu(struct rcu_head *head)
 514 {
 515         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 516         struct net *net = nf_ct_net(ct);
 517
 518         nf_ct_ext_free(ct);
 519         kmem_cache_free(nf_conntrack_cachep, ct);
 520         atomic_dec(&net->ct.count);
 521 }
 522
 523 void nf_conntrack_free(struct nf_conn *ct)
 524 {
 525         nf_ct_ext_destroy(ct);
 526         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 527 }
 528 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 529
 530 /* Allocate a new conntrack: we return -ENOMEM if classification
 531    failed due to stress.  Otherwise it really is unclassifiable. */
 532 static struct nf_conntrack_tuple_hash *
 533 init_conntrack(struct net *net,
 534                const struct nf_conntrack_tuple *tuple,
 535                struct nf_conntrack_l3proto *l3proto,
 536                struct nf_conntrack_l4proto *l4proto,
 537                struct sk_buff *skb,
 538                unsigned int dataoff)
 539 {
 540         struct nf_conn *ct;
 541         struct nf_conn_help *help;
 542         struct nf_conntrack_tuple repl_tuple;
 543         struct nf_conntrack_expect *exp;
 544
 545         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 546                 pr_debug("Can't invert tuple.\n");
 547                 return NULL;
 548         }
 549
 550         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 551         if (ct == NULL || IS_ERR(ct)) {
 552                 pr_debug("Can't allocate conntrack.\n");
 553                 return (struct nf_conntrack_tuple_hash *)ct;
 554         }
 555
 556         if (!l4proto->new(ct, skb, dataoff)) {
 557                 nf_conntrack_free(ct);
 558                 pr_debug("init conntrack: can't track with proto module\n");
 559                 return NULL;
 560         }
 561
 562         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 563
 564         spin_lock_bh(&nf_conntrack_lock);
 565         exp = nf_ct_find_expectation(tuple);
 566         if (exp) {
 567                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 568                          ct, exp);
 569                 /* Welcome, Mr. Bond.  We've been expecting you... */
 570                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 571                 ct->master = exp->master;
 572                 if (exp->helper) {
 573                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 574                         if (help)
 575                                 rcu_assign_pointer(help->helper, exp->helper);
 576                 }
 577
 578 #ifdef CONFIG_NF_CONNTRACK_MARK
 579                 ct->mark = exp->master->mark;
 580 #endif
 581 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 582                 ct->secmark = exp->master->secmark;
 583 #endif
 584                 nf_conntrack_get(&ct->master->ct_general);
 585                 NF_CT_STAT_INC(expect_new);
 586         } else {
 587                 struct nf_conntrack_helper *helper;
 588
 589                 helper = __nf_ct_helper_find(&repl_tuple);
 590                 if (helper) {
 591                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 592                         if (help)
 593                                 rcu_assign_pointer(help->helper, helper);
 594                 }
 595                 NF_CT_STAT_INC(new);
 596         }
 597
 598         /* Overload tuple linked list to put us in unconfirmed list. */
 599         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, &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, &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();
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
1158         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1159
1160         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1161                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1162                nf_conntrack_max);
1163
1164         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1165                                                 sizeof(struct nf_conn),
1166                                                 0, 0, NULL);
1167         if (!nf_conntrack_cachep) {
1168                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1169                 goto err_free_hash;
1170         }
1171
1172         ret = nf_conntrack_proto_init();
1173         if (ret < 0)
1174                 goto err_free_conntrack_slab;
1175
1176         ret = nf_conntrack_expect_init();
1177         if (ret < 0)
1178                 goto out_fini_proto;
1179
1180         ret = nf_conntrack_helper_init();
1181         if (ret < 0)
1182                 goto out_fini_expect;
1183
1184         ret = nf_conntrack_acct_init();
1185         if (ret < 0)
1186                 goto out_fini_helper;
1187
1188         /* For use by REJECT target */
1189         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1190         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1191
1192         /* Set up fake conntrack:
1193             - to never be deleted, not in any hashes */
1194 #ifdef CONFIG_NET_NS
1195         nf_conntrack_untracked.ct_net = &init_net;
1196 #endif
1197         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1198         /*  - and look it like as a confirmed connection */
1199         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1200
1201         return ret;
1202
1203 out_fini_helper:
1204         nf_conntrack_helper_fini();
1205 out_fini_expect:
1206         nf_conntrack_expect_fini();
1207 out_fini_proto:
1208         nf_conntrack_proto_fini();
1209 err_free_conntrack_slab:
1210         kmem_cache_destroy(nf_conntrack_cachep);
1211 err_free_hash:
1212         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1213                              nf_conntrack_htable_size);
1214 err_out:
1215         return -ENOMEM;
1216 }