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 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  57
  58 static int nf_conntrack_hash_rnd_initted;
  59 static unsigned int nf_conntrack_hash_rnd;
  60
  61 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  62                                   unsigned int size, unsigned int rnd)
  63 {
  64         unsigned int n;
  65         u_int32_t h;
  66
  67         /* The direction must be ignored, so we hash everything up to the
  68          * destination ports (which is a multiple of 4) and treat the last
  69          * three bytes manually.
  70          */
  71         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  72         h = jhash2((u32 *)tuple, n,
  73                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  74                           tuple->dst.protonum));
  75
  76         return ((u64)h * size) >> 32;
  77 }
  78
  79 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  80 {
  81         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  82                                 nf_conntrack_hash_rnd);
  83 }
  84
  85 bool
  86 nf_ct_get_tuple(const struct sk_buff *skb,
  87                 unsigned int nhoff,
  88                 unsigned int dataoff,
  89                 u_int16_t l3num,
  90                 u_int8_t protonum,
  91                 struct nf_conntrack_tuple *tuple,
  92                 const struct nf_conntrack_l3proto *l3proto,
  93                 const struct nf_conntrack_l4proto *l4proto)
  94 {
  95         memset(tuple, 0, sizeof(*tuple));
  96
  97         tuple->src.l3num = l3num;
  98         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
  99                 return false;
 100
 101         tuple->dst.protonum = protonum;
 102         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 103
 104         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 105 }
 106 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 107
 108 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 109                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 110 {
 111         struct nf_conntrack_l3proto *l3proto;
 112         struct nf_conntrack_l4proto *l4proto;
 113         unsigned int protoff;
 114         u_int8_t protonum;
 115         int ret;
 116
 117         rcu_read_lock();
 118
 119         l3proto = __nf_ct_l3proto_find(l3num);
 120         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 121         if (ret != NF_ACCEPT) {
 122                 rcu_read_unlock();
 123                 return false;
 124         }
 125
 126         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 127
 128         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 129                               l3proto, l4proto);
 130
 131         rcu_read_unlock();
 132         return ret;
 133 }
 134 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 135
 136 bool
 137 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 138                    const struct nf_conntrack_tuple *orig,
 139                    const struct nf_conntrack_l3proto *l3proto,
 140                    const struct nf_conntrack_l4proto *l4proto)
 141 {
 142         memset(inverse, 0, sizeof(*inverse));
 143
 144         inverse->src.l3num = orig->src.l3num;
 145         if (l3proto->invert_tuple(inverse, orig) == 0)
 146                 return false;
 147
 148         inverse->dst.dir = !orig->dst.dir;
 149
 150         inverse->dst.protonum = orig->dst.protonum;
 151         return l4proto->invert_tuple(inverse, orig);
 152 }
 153 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 154
 155 static void
 156 clean_from_lists(struct nf_conn *ct)
 157 {
 158         pr_debug("clean_from_lists(%p)\n", ct);
 159         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 160         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 161
 162         /* Destroy all pending expectations */
 163         nf_ct_remove_expectations(ct);
 164 }
 165
 166 static void
 167 destroy_conntrack(struct nf_conntrack *nfct)
 168 {
 169         struct nf_conn *ct = (struct nf_conn *)nfct;
 170         struct net *net = nf_ct_net(ct);
 171         struct nf_conntrack_l4proto *l4proto;
 172
 173         pr_debug("destroy_conntrack(%p)\n", ct);
 174         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 175         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 176
 177         nf_conntrack_event(IPCT_DESTROY, ct);
 178         set_bit(IPS_DYING_BIT, &ct->status);
 179
 180         /* To make sure we don't get any weird locking issues here:
 181          * destroy_conntrack() MUST NOT be called with a write lock
 182          * to nf_conntrack_lock!!! -HW */
 183         rcu_read_lock();
 184         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 185         if (l4proto && l4proto->destroy)
 186                 l4proto->destroy(ct);
 187
 188         rcu_read_unlock();
 189
 190         spin_lock_bh(&nf_conntrack_lock);
 191         /* Expectations will have been removed in clean_from_lists,
 192          * except TFTP can create an expectation on the first packet,
 193          * before connection is in the list, so we need to clean here,
 194          * too. */
 195         nf_ct_remove_expectations(ct);
 196
 197         /* We overload first tuple to link into unconfirmed list. */
 198         if (!nf_ct_is_confirmed(ct)) {
 199                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 200                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 201         }
 202
 203         NF_CT_STAT_INC(net, delete);
 204         spin_unlock_bh(&nf_conntrack_lock);
 205
 206         if (ct->master)
 207                 nf_ct_put(ct->master);
 208
 209         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 210         nf_conntrack_free(ct);
 211 }
 212
 213 static void death_by_timeout(unsigned long ul_conntrack)
 214 {
 215         struct nf_conn *ct = (void *)ul_conntrack;
 216         struct net *net = nf_ct_net(ct);
 217         struct nf_conn_help *help = nfct_help(ct);
 218         struct nf_conntrack_helper *helper;
 219
 220         if (help) {
 221                 rcu_read_lock();
 222                 helper = rcu_dereference(help->helper);
 223                 if (helper && helper->destroy)
 224                         helper->destroy(ct);
 225                 rcu_read_unlock();
 226         }
 227
 228         spin_lock_bh(&nf_conntrack_lock);
 229         /* Inside lock so preempt is disabled on module removal path.
 230          * Otherwise we can get spurious warnings. */
 231         NF_CT_STAT_INC(net, delete_list);
 232         clean_from_lists(ct);
 233         spin_unlock_bh(&nf_conntrack_lock);
 234         nf_ct_put(ct);
 235 }
 236
 237 struct nf_conntrack_tuple_hash *
 238 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 239 {
 240         struct nf_conntrack_tuple_hash *h;
 241         struct hlist_node *n;
 242         unsigned int hash = hash_conntrack(tuple);
 243
 244         /* Disable BHs the entire time since we normally need to disable them
 245          * at least once for the stats anyway.
 246          */
 247         local_bh_disable();
 248         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 249                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 250                         NF_CT_STAT_INC(net, found);
 251                         local_bh_enable();
 252                         return h;
 253                 }
 254                 NF_CT_STAT_INC(net, searched);
 255         }
 256         local_bh_enable();
 257
 258         return NULL;
 259 }
 260 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 261
 262 /* Find a connection corresponding to a tuple. */
 263 struct nf_conntrack_tuple_hash *
 264 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 265 {
 266         struct nf_conntrack_tuple_hash *h;
 267         struct nf_conn *ct;
 268
 269         rcu_read_lock();
 270         h = __nf_conntrack_find(net, tuple);
 271         if (h) {
 272                 ct = nf_ct_tuplehash_to_ctrack(h);
 273                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 274                         h = NULL;
 275         }
 276         rcu_read_unlock();
 277
 278         return h;
 279 }
 280 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 281
 282 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 283                                        unsigned int hash,
 284                                        unsigned int repl_hash)
 285 {
 286         struct net *net = nf_ct_net(ct);
 287
 288         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 289                            &net->ct.hash[hash]);
 290         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 291                            &net->ct.hash[repl_hash]);
 292 }
 293
 294 void nf_conntrack_hash_insert(struct nf_conn *ct)
 295 {
 296         unsigned int hash, repl_hash;
 297
 298         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 299         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 300
 301         spin_lock_bh(&nf_conntrack_lock);
 302         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 303         spin_unlock_bh(&nf_conntrack_lock);
 304 }
 305 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 306
 307 /* Confirm a connection given skb; places it in hash table */
 308 int
 309 __nf_conntrack_confirm(struct sk_buff *skb)
 310 {
 311         unsigned int hash, repl_hash;
 312         struct nf_conntrack_tuple_hash *h;
 313         struct nf_conn *ct;
 314         struct nf_conn_help *help;
 315         struct hlist_node *n;
 316         enum ip_conntrack_info ctinfo;
 317         struct net *net;
 318
 319         ct = nf_ct_get(skb, &ctinfo);
 320         net = nf_ct_net(ct);
 321
 322         /* ipt_REJECT uses nf_conntrack_attach to attach related
 323            ICMP/TCP RST packets in other direction.  Actual packet
 324            which created connection will be IP_CT_NEW or for an
 325            expected connection, IP_CT_RELATED. */
 326         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 327                 return NF_ACCEPT;
 328
 329         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 330         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 331
 332         /* We're not in hash table, and we refuse to set up related
 333            connections for unconfirmed conns.  But packet copies and
 334            REJECT will give spurious warnings here. */
 335         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 336
 337         /* No external references means noone else could have
 338            confirmed us. */
 339         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 340         pr_debug("Confirming conntrack %p\n", ct);
 341
 342         spin_lock_bh(&nf_conntrack_lock);
 343
 344         /* See if there's one in the list already, including reverse:
 345            NAT could have grabbed it without realizing, since we're
 346            not in the hash.  If there is, we lost race. */
 347         hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode)
 348                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 349                                       &h->tuple))
 350                         goto out;
 351         hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode)
 352                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 353                                       &h->tuple))
 354                         goto out;
 355
 356         /* Remove from unconfirmed list */
 357         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 358
 359         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 360         /* Timer relative to confirmation time, not original
 361            setting time, otherwise we'd get timer wrap in
 362            weird delay cases. */
 363         ct->timeout.expires += jiffies;
 364         add_timer(&ct->timeout);
 365         atomic_inc(&ct->ct_general.use);
 366         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 367         NF_CT_STAT_INC(net, insert);
 368         spin_unlock_bh(&nf_conntrack_lock);
 369         help = nfct_help(ct);
 370         if (help && help->helper)
 371                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 372 #ifdef CONFIG_NF_NAT_NEEDED
 373         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 374             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 375                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
 376 #endif
 377         nf_conntrack_event_cache(master_ct(ct) ?
 378                                  IPCT_RELATED : IPCT_NEW, ct);
 379         return NF_ACCEPT;
 380
 381 out:
 382         NF_CT_STAT_INC(net, insert_failed);
 383         spin_unlock_bh(&nf_conntrack_lock);
 384         return NF_DROP;
 385 }
 386 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 387
 388 /* Returns true if a connection correspondings to the tuple (required
 389    for NAT). */
 390 int
 391 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 392                          const struct nf_conn *ignored_conntrack)
 393 {
 394         struct net *net = nf_ct_net(ignored_conntrack);
 395         struct nf_conntrack_tuple_hash *h;
 396         struct hlist_node *n;
 397         unsigned int hash = hash_conntrack(tuple);
 398
 399         /* Disable BHs the entire time since we need to disable them at
 400          * least once for the stats anyway.
 401          */
 402         rcu_read_lock_bh();
 403         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 404                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 405                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 406                         NF_CT_STAT_INC(net, found);
 407                         rcu_read_unlock_bh();
 408                         return 1;
 409                 }
 410                 NF_CT_STAT_INC(net, searched);
 411         }
 412         rcu_read_unlock_bh();
 413
 414         return 0;
 415 }
 416 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 417
 418 #define NF_CT_EVICTION_RANGE    8
 419
 420 /* There's a small race here where we may free a just-assured
 421    connection.  Too bad: we're in trouble anyway. */
 422 static noinline int early_drop(struct net *net, unsigned int hash)
 423 {
 424         /* Use oldest entry, which is roughly LRU */
 425         struct nf_conntrack_tuple_hash *h;
 426         struct nf_conn *ct = NULL, *tmp;
 427         struct hlist_node *n;
 428         unsigned int i, cnt = 0;
 429         int dropped = 0;
 430
 431         rcu_read_lock();
 432         for (i = 0; i < nf_conntrack_htable_size; i++) {
 433                 hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 434                                          hnode) {
 435                         tmp = nf_ct_tuplehash_to_ctrack(h);
 436                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 437                                 ct = tmp;
 438                         cnt++;
 439                 }
 440
 441                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 442                         ct = NULL;
 443                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 444                         break;
 445                 hash = (hash + 1) % nf_conntrack_htable_size;
 446         }
 447         rcu_read_unlock();
 448
 449         if (!ct)
 450                 return dropped;
 451
 452         if (del_timer(&ct->timeout)) {
 453                 death_by_timeout((unsigned long)ct);
 454                 dropped = 1;
 455                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
 456         }
 457         nf_ct_put(ct);
 458         return dropped;
 459 }
 460
 461 struct nf_conn *nf_conntrack_alloc(struct net *net,
 462                                    const struct nf_conntrack_tuple *orig,
 463                                    const struct nf_conntrack_tuple *repl,
 464                                    gfp_t gfp)
 465 {
 466         struct nf_conn *ct = NULL;
 467
 468         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 469                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 470                 nf_conntrack_hash_rnd_initted = 1;
 471         }
 472
 473         /* We don't want any race condition at early drop stage */
 474         atomic_inc(&net->ct.count);
 475
 476         if (nf_conntrack_max &&
 477             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 478                 unsigned int hash = hash_conntrack(orig);
 479                 if (!early_drop(net, hash)) {
 480                         atomic_dec(&net->ct.count);
 481                         if (net_ratelimit())
 482                                 printk(KERN_WARNING
 483                                        "nf_conntrack: table full, dropping"
 484                                        " packet.\n");
 485                         return ERR_PTR(-ENOMEM);
 486                 }
 487         }
 488
 489         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 490         if (ct == NULL) {
 491                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 492                 atomic_dec(&net->ct.count);
 493                 return ERR_PTR(-ENOMEM);
 494         }
 495
 496         atomic_set(&ct->ct_general.use, 1);
 497         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 498         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 499         /* Don't set timer yet: wait for confirmation */
 500         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 501 #ifdef CONFIG_NET_NS
 502         ct->ct_net = net;
 503 #endif
 504         INIT_RCU_HEAD(&ct->rcu);
 505
 506         return ct;
 507 }
 508 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 509
 510 static void nf_conntrack_free_rcu(struct rcu_head *head)
 511 {
 512         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 513         struct net *net = nf_ct_net(ct);
 514
 515         nf_ct_ext_free(ct);
 516         kmem_cache_free(nf_conntrack_cachep, ct);
 517         atomic_dec(&net->ct.count);
 518 }
 519
 520 void nf_conntrack_free(struct nf_conn *ct)
 521 {
 522         nf_ct_ext_destroy(ct);
 523         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 524 }
 525 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 526
 527 /* Allocate a new conntrack: we return -ENOMEM if classification
 528    failed due to stress.  Otherwise it really is unclassifiable. */
 529 static struct nf_conntrack_tuple_hash *
 530 init_conntrack(struct net *net,
 531                const struct nf_conntrack_tuple *tuple,
 532                struct nf_conntrack_l3proto *l3proto,
 533                struct nf_conntrack_l4proto *l4proto,
 534                struct sk_buff *skb,
 535                unsigned int dataoff)
 536 {
 537         struct nf_conn *ct;
 538         struct nf_conn_help *help;
 539         struct nf_conntrack_tuple repl_tuple;
 540         struct nf_conntrack_expect *exp;
 541
 542         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 543                 pr_debug("Can't invert tuple.\n");
 544                 return NULL;
 545         }
 546
 547         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 548         if (ct == NULL || IS_ERR(ct)) {
 549                 pr_debug("Can't allocate conntrack.\n");
 550                 return (struct nf_conntrack_tuple_hash *)ct;
 551         }
 552
 553         if (!l4proto->new(ct, skb, dataoff)) {
 554                 nf_conntrack_free(ct);
 555                 pr_debug("init conntrack: can't track with proto module\n");
 556                 return NULL;
 557         }
 558
 559         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 560
 561         spin_lock_bh(&nf_conntrack_lock);
 562         exp = nf_ct_find_expectation(net, tuple);
 563         if (exp) {
 564                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 565                          ct, exp);
 566                 /* Welcome, Mr. Bond.  We've been expecting you... */
 567                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 568                 ct->master = exp->master;
 569                 if (exp->helper) {
 570                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 571                         if (help)
 572                                 rcu_assign_pointer(help->helper, exp->helper);
 573                 }
 574
 575 #ifdef CONFIG_NF_CONNTRACK_MARK
 576                 ct->mark = exp->master->mark;
 577 #endif
 578 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 579                 ct->secmark = exp->master->secmark;
 580 #endif
 581                 nf_conntrack_get(&ct->master->ct_general);
 582                 NF_CT_STAT_INC(net, expect_new);
 583         } else {
 584                 struct nf_conntrack_helper *helper;
 585
 586                 helper = __nf_ct_helper_find(&repl_tuple);
 587                 if (helper) {
 588                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 589                         if (help)
 590                                 rcu_assign_pointer(help->helper, helper);
 591                 }
 592                 NF_CT_STAT_INC(net, new);
 593         }
 594
 595         /* Overload tuple linked list to put us in unconfirmed list. */
 596         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 597                        &net->ct.unconfirmed);
 598
 599         spin_unlock_bh(&nf_conntrack_lock);
 600
 601         if (exp) {
 602                 if (exp->expectfn)
 603                         exp->expectfn(ct, exp);
 604                 nf_ct_expect_put(exp);
 605         }
 606
 607         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 608 }
 609
 610 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 611 static inline struct nf_conn *
 612 resolve_normal_ct(struct net *net,
 613                   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(net, &tuple);
 635         if (!h) {
 636                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
 637                 if (!h)
 638                         return NULL;
 639                 if (IS_ERR(h))
 640                         return (void *)h;
 641         }
 642         ct = nf_ct_tuplehash_to_ctrack(h);
 643
 644         /* It exists; we have (non-exclusive) reference. */
 645         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 646                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 647                 /* Please set reply bit if this packet OK */
 648                 *set_reply = 1;
 649         } else {
 650                 /* Once we've had two way comms, always ESTABLISHED. */
 651                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 652                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 653                         *ctinfo = IP_CT_ESTABLISHED;
 654                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 655                         pr_debug("nf_conntrack_in: related packet for %p\n",
 656                                  ct);
 657                         *ctinfo = IP_CT_RELATED;
 658                 } else {
 659                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 660                         *ctinfo = IP_CT_NEW;
 661                 }
 662                 *set_reply = 0;
 663         }
 664         skb->nfct = &ct->ct_general;
 665         skb->nfctinfo = *ctinfo;
 666         return ct;
 667 }
 668
 669 unsigned int
 670 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
 671                 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(net, 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(net, error);
 695                 NF_CT_STAT_INC_ATOMIC(net, 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(net, skb, dataoff, &ctinfo, pf, hooknum);
 706                 if (ret <= 0) {
 707                         NF_CT_STAT_INC_ATOMIC(net, error);
 708                         NF_CT_STAT_INC_ATOMIC(net, invalid);
 709                         return -ret;
 710                 }
 711         }
 712
 713         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
 714                                l3proto, l4proto, &set_reply, &ctinfo);
 715         if (!ct) {
 716                 /* Not valid part of a connection */
 717                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 718                 return NF_ACCEPT;
 719         }
 720
 721         if (IS_ERR(ct)) {
 722                 /* Too stressed to deal. */
 723                 NF_CT_STAT_INC_ATOMIC(net, drop);
 724                 return NF_DROP;
 725         }
 726
 727         NF_CT_ASSERT(skb->nfct);
 728
 729         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 730         if (ret < 0) {
 731                 /* Invalid: inverse of the return code tells
 732                  * the netfilter core what to do */
 733                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 734                 nf_conntrack_put(skb->nfct);
 735                 skb->nfct = NULL;
 736                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 737                 return -ret;
 738         }
 739
 740         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 741                 nf_conntrack_event_cache(IPCT_STATUS, ct);
 742
 743         return ret;
 744 }
 745 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 746
 747 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 748                           const struct nf_conntrack_tuple *orig)
 749 {
 750         bool ret;
 751
 752         rcu_read_lock();
 753         ret = nf_ct_invert_tuple(inverse, orig,
 754                                  __nf_ct_l3proto_find(orig->src.l3num),
 755                                  __nf_ct_l4proto_find(orig->src.l3num,
 756                                                       orig->dst.protonum));
 757         rcu_read_unlock();
 758         return ret;
 759 }
 760 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 761
 762 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 763    implicitly racy: see __nf_conntrack_confirm */
 764 void nf_conntrack_alter_reply(struct nf_conn *ct,
 765                               const struct nf_conntrack_tuple *newreply)
 766 {
 767         struct nf_conn_help *help = nfct_help(ct);
 768         struct nf_conntrack_helper *helper;
 769
 770         /* Should be unconfirmed, so not in hash table yet */
 771         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 772
 773         pr_debug("Altering reply tuple of %p to ", ct);
 774         nf_ct_dump_tuple(newreply);
 775
 776         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 777         if (ct->master || (help && !hlist_empty(&help->expectations)))
 778                 return;
 779
 780         rcu_read_lock();
 781         helper = __nf_ct_helper_find(newreply);
 782         if (helper == NULL) {
 783                 if (help)
 784                         rcu_assign_pointer(help->helper, NULL);
 785                 goto out;
 786         }
 787
 788         if (help == NULL) {
 789                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 790                 if (help == NULL)
 791                         goto out;
 792         } else {
 793                 memset(&help->help, 0, sizeof(help->help));
 794         }
 795
 796         rcu_assign_pointer(help->helper, helper);
 797 out:
 798         rcu_read_unlock();
 799 }
 800 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 801
 802 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 803 void __nf_ct_refresh_acct(struct nf_conn *ct,
 804                           enum ip_conntrack_info ctinfo,
 805                           const struct sk_buff *skb,
 806                           unsigned long extra_jiffies,
 807                           int do_acct)
 808 {
 809         int event = 0;
 810
 811         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 812         NF_CT_ASSERT(skb);
 813
 814         spin_lock_bh(&nf_conntrack_lock);
 815
 816         /* Only update if this is not a fixed timeout */
 817         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 818                 goto acct;
 819
 820         /* If not in hash table, timer will not be active yet */
 821         if (!nf_ct_is_confirmed(ct)) {
 822                 ct->timeout.expires = extra_jiffies;
 823                 event = IPCT_REFRESH;
 824         } else {
 825                 unsigned long newtime = jiffies + extra_jiffies;
 826
 827                 /* Only update the timeout if the new timeout is at least
 828                    HZ jiffies from the old timeout. Need del_timer for race
 829                    avoidance (may already be dying). */
 830                 if (newtime - ct->timeout.expires >= HZ
 831                     && del_timer(&ct->timeout)) {
 832                         ct->timeout.expires = newtime;
 833                         add_timer(&ct->timeout);
 834                         event = IPCT_REFRESH;
 835                 }
 836         }
 837
 838 acct:
 839         if (do_acct) {
 840                 struct nf_conn_counter *acct;
 841
 842                 acct = nf_conn_acct_find(ct);
 843                 if (acct) {
 844                         acct[CTINFO2DIR(ctinfo)].packets++;
 845                         acct[CTINFO2DIR(ctinfo)].bytes +=
 846                                 skb->len - skb_network_offset(skb);
 847                 }
 848         }
 849
 850         spin_unlock_bh(&nf_conntrack_lock);
 851
 852         /* must be unlocked when calling event cache */
 853         if (event)
 854                 nf_conntrack_event_cache(event, ct);
 855 }
 856 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 857
 858 bool __nf_ct_kill_acct(struct nf_conn *ct,
 859                        enum ip_conntrack_info ctinfo,
 860                        const struct sk_buff *skb,
 861                        int do_acct)
 862 {
 863         if (do_acct) {
 864                 struct nf_conn_counter *acct;
 865
 866                 spin_lock_bh(&nf_conntrack_lock);
 867                 acct = nf_conn_acct_find(ct);
 868                 if (acct) {
 869                         acct[CTINFO2DIR(ctinfo)].packets++;
 870                         acct[CTINFO2DIR(ctinfo)].bytes +=
 871                                 skb->len - skb_network_offset(skb);
 872                 }
 873                 spin_unlock_bh(&nf_conntrack_lock);
 874         }
 875
 876         if (del_timer(&ct->timeout)) {
 877                 ct->timeout.function((unsigned long)ct);
 878                 return true;
 879         }
 880         return false;
 881 }
 882 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 883
 884 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 885
 886 #include <linux/netfilter/nfnetlink.h>
 887 #include <linux/netfilter/nfnetlink_conntrack.h>
 888 #include <linux/mutex.h>
 889
 890 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 891  * in ip_conntrack_core, since we don't want the protocols to autoload
 892  * or depend on ctnetlink */
 893 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 894                                const struct nf_conntrack_tuple *tuple)
 895 {
 896         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 897         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 898         return 0;
 899
 900 nla_put_failure:
 901         return -1;
 902 }
 903 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 904
 905 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 906         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 907         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 908 };
 909 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 910
 911 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 912                                struct nf_conntrack_tuple *t)
 913 {
 914         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 915                 return -EINVAL;
 916
 917         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 918         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 919
 920         return 0;
 921 }
 922 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 923 #endif
 924
 925 /* Used by ipt_REJECT and ip6t_REJECT. */
 926 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 927 {
 928         struct nf_conn *ct;
 929         enum ip_conntrack_info ctinfo;
 930
 931         /* This ICMP is in reverse direction to the packet which caused it */
 932         ct = nf_ct_get(skb, &ctinfo);
 933         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 934                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 935         else
 936                 ctinfo = IP_CT_RELATED;
 937
 938         /* Attach to new skbuff, and increment count */
 939         nskb->nfct = &ct->ct_general;
 940         nskb->nfctinfo = ctinfo;
 941         nf_conntrack_get(nskb->nfct);
 942 }
 943
 944 /* Bring out ya dead! */
 945 static struct nf_conn *
 946 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 947                 void *data, unsigned int *bucket)
 948 {
 949         struct nf_conntrack_tuple_hash *h;
 950         struct nf_conn *ct;
 951         struct hlist_node *n;
 952
 953         spin_lock_bh(&nf_conntrack_lock);
 954         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 955                 hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) {
 956                         ct = nf_ct_tuplehash_to_ctrack(h);
 957                         if (iter(ct, data))
 958                                 goto found;
 959                 }
 960         }
 961         hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) {
 962                 ct = nf_ct_tuplehash_to_ctrack(h);
 963                 if (iter(ct, data))
 964                         set_bit(IPS_DYING_BIT, &ct->status);
 965         }
 966         spin_unlock_bh(&nf_conntrack_lock);
 967         return NULL;
 968 found:
 969         atomic_inc(&ct->ct_general.use);
 970         spin_unlock_bh(&nf_conntrack_lock);
 971         return ct;
 972 }
 973
 974 void nf_ct_iterate_cleanup(struct net *net,
 975                            int (*iter)(struct nf_conn *i, void *data),
 976                            void *data)
 977 {
 978         struct nf_conn *ct;
 979         unsigned int bucket = 0;
 980
 981         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 982                 /* Time to push up daises... */
 983                 if (del_timer(&ct->timeout))
 984                         death_by_timeout((unsigned long)ct);
 985                 /* ... else the timer will get him soon. */
 986
 987                 nf_ct_put(ct);
 988         }
 989 }
 990 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 991
 992 static int kill_all(struct nf_conn *i, void *data)
 993 {
 994         return 1;
 995 }
 996
 997 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 998 {
 999         if (vmalloced)
1000                 vfree(hash);
1001         else
1002                 free_pages((unsigned long)hash,
1003                            get_order(sizeof(struct hlist_head) * size));
1004 }
1005 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1006
1007 void nf_conntrack_flush(struct net *net)
1008 {
1009         nf_ct_iterate_cleanup(net, kill_all, NULL);
1010 }
1011 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1012
1013 /* Mishearing the voices in his head, our hero wonders how he's
1014    supposed to kill the mall. */
1015 void nf_conntrack_cleanup(struct net *net)
1016 {
1017         rcu_assign_pointer(ip_ct_attach, NULL);
1018
1019         /* This makes sure all current packets have passed through
1020            netfilter framework.  Roll on, two-stage module
1021            delete... */
1022         synchronize_net();
1023
1024         nf_ct_event_cache_flush(net);
1025         nf_conntrack_ecache_fini(net);
1026  i_see_dead_people:
1027         nf_conntrack_flush(net);
1028         if (atomic_read(&net->ct.count) != 0) {
1029                 schedule();
1030                 goto i_see_dead_people;
1031         }
1032         /* wait until all references to nf_conntrack_untracked are dropped */
1033         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1034                 schedule();
1035
1036         rcu_assign_pointer(nf_ct_destroy, NULL);
1037
1038         kmem_cache_destroy(nf_conntrack_cachep);
1039         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1040                              nf_conntrack_htable_size);
1041
1042         nf_conntrack_acct_fini();
1043         nf_conntrack_expect_fini(net);
1044         free_percpu(net->ct.stat);
1045         nf_conntrack_helper_fini();
1046         nf_conntrack_proto_fini();
1047 }
1048
1049 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1050 {
1051         struct hlist_head *hash;
1052         unsigned int size, i;
1053
1054         *vmalloced = 0;
1055
1056         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1057         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1058                                        get_order(sizeof(struct hlist_head)
1059                                                  * size));
1060         if (!hash) {
1061                 *vmalloced = 1;
1062                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1063                 hash = vmalloc(sizeof(struct hlist_head) * size);
1064         }
1065
1066         if (hash)
1067                 for (i = 0; i < size; i++)
1068                         INIT_HLIST_HEAD(&hash[i]);
1069
1070         return hash;
1071 }
1072 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1073
1074 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1075 {
1076         int i, bucket, vmalloced, old_vmalloced;
1077         unsigned int hashsize, old_size;
1078         int rnd;
1079         struct hlist_head *hash, *old_hash;
1080         struct nf_conntrack_tuple_hash *h;
1081
1082         /* On boot, we can set this without any fancy locking. */
1083         if (!nf_conntrack_htable_size)
1084                 return param_set_uint(val, kp);
1085
1086         hashsize = simple_strtoul(val, NULL, 0);
1087         if (!hashsize)
1088                 return -EINVAL;
1089
1090         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1091         if (!hash)
1092                 return -ENOMEM;
1093
1094         /* We have to rehahs for the new table anyway, so we also can
1095          * use a newrandom seed */
1096         get_random_bytes(&rnd, 4);
1097
1098         /* Lookups in the old hash might happen in parallel, which means we
1099          * might get false negatives during connection lookup. New connections
1100          * created because of a false negative won't make it into the hash
1101          * though since that required taking the lock.
1102          */
1103         spin_lock_bh(&nf_conntrack_lock);
1104         for (i = 0; i < nf_conntrack_htable_size; i++) {
1105                 while (!hlist_empty(&init_net.ct.hash[i])) {
1106                         h = hlist_entry(init_net.ct.hash[i].first,
1107                                         struct nf_conntrack_tuple_hash, hnode);
1108                         hlist_del_rcu(&h->hnode);
1109                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1110                         hlist_add_head(&h->hnode, &hash[bucket]);
1111                 }
1112         }
1113         old_size = nf_conntrack_htable_size;
1114         old_vmalloced = init_net.ct.hash_vmalloc;
1115         old_hash = init_net.ct.hash;
1116
1117         nf_conntrack_htable_size = hashsize;
1118         init_net.ct.hash_vmalloc = vmalloced;
1119         init_net.ct.hash = hash;
1120         nf_conntrack_hash_rnd = rnd;
1121         spin_unlock_bh(&nf_conntrack_lock);
1122
1123         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1124         return 0;
1125 }
1126 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1127
1128 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1129                   &nf_conntrack_htable_size, 0600);
1130
1131 int nf_conntrack_init(struct net *net)
1132 {
1133         int max_factor = 8;
1134         int ret;
1135
1136         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1137          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1138         if (!nf_conntrack_htable_size) {
1139                 nf_conntrack_htable_size
1140                         = (((num_physpages << PAGE_SHIFT) / 16384)
1141                            / sizeof(struct hlist_head));
1142                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1143                         nf_conntrack_htable_size = 16384;
1144                 if (nf_conntrack_htable_size < 32)
1145                         nf_conntrack_htable_size = 32;
1146
1147                 /* Use a max. factor of four by default to get the same max as
1148                  * with the old struct list_heads. When a table size is given
1149                  * we use the old value of 8 to avoid reducing the max.
1150                  * entries. */
1151                 max_factor = 4;
1152         }
1153         atomic_set(&net->ct.count, 0);
1154         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1155         if (!net->ct.stat)
1156                 goto err_stat;
1157         ret = nf_conntrack_ecache_init(net);
1158         if (ret < 0)
1159                 goto err_ecache;
1160         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1161                                                   &net->ct.hash_vmalloc);
1162         if (!net->ct.hash) {
1163                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1164                 goto err_hash;
1165         }
1166         INIT_HLIST_HEAD(&net->ct.unconfirmed);
1167
1168         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1169
1170         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1171                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1172                nf_conntrack_max);
1173
1174         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1175                                                 sizeof(struct nf_conn),
1176                                                 0, 0, NULL);
1177         if (!nf_conntrack_cachep) {
1178                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1179                 goto err_free_hash;
1180         }
1181
1182         ret = nf_conntrack_proto_init();
1183         if (ret < 0)
1184                 goto err_free_conntrack_slab;
1185
1186         ret = nf_conntrack_expect_init(net);
1187         if (ret < 0)
1188                 goto out_fini_proto;
1189
1190         ret = nf_conntrack_helper_init();
1191         if (ret < 0)
1192                 goto out_fini_expect;
1193
1194         ret = nf_conntrack_acct_init();
1195         if (ret < 0)
1196                 goto out_fini_helper;
1197
1198         /* For use by REJECT target */
1199         rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1200         rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1201
1202         /* Set up fake conntrack:
1203             - to never be deleted, not in any hashes */
1204 #ifdef CONFIG_NET_NS
1205         nf_conntrack_untracked.ct_net = &init_net;
1206 #endif
1207         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1208         /*  - and look it like as a confirmed connection */
1209         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1210
1211         return ret;
1212
1213 out_fini_helper:
1214         nf_conntrack_helper_fini();
1215 out_fini_expect:
1216         nf_conntrack_expect_fini(net);
1217 out_fini_proto:
1218         nf_conntrack_proto_fini();
1219 err_free_conntrack_slab:
1220         kmem_cache_destroy(nf_conntrack_cachep);
1221 err_free_hash:
1222         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1223                              nf_conntrack_htable_size);
1224 err_hash:
1225         nf_conntrack_ecache_fini(net);
1226 err_ecache:
1227         free_percpu(net->ct.stat);
1228 err_stat:
1229         return -ENOMEM;
1230 }