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 #include <net/netfilter/nf_nat.h>
  42 #include <net/netfilter/nf_nat_core.h>
  43
  44 #define NF_CONNTRACK_VERSION    "0.5.0"
  45
  46 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
  47                                       enum nf_nat_manip_type manip,
  48                                       struct nlattr *attr) __read_mostly;
  49 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
  50
  51 DEFINE_SPINLOCK(nf_conntrack_lock);
  52 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  53
  54 unsigned int nf_conntrack_htable_size __read_mostly;
  55 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
  56
  57 int nf_conntrack_max __read_mostly;
  58 EXPORT_SYMBOL_GPL(nf_conntrack_max);
  59
  60 struct nf_conn nf_conntrack_untracked __read_mostly;
  61 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
  62
  63 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  64
  65 static int nf_conntrack_hash_rnd_initted;
  66 static unsigned int nf_conntrack_hash_rnd;
  67
  68 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  69                                   unsigned int size, unsigned int rnd)
  70 {
  71         unsigned int n;
  72         u_int32_t h;
  73
  74         /* The direction must be ignored, so we hash everything up to the
  75          * destination ports (which is a multiple of 4) and treat the last
  76          * three bytes manually.
  77          */
  78         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  79         h = jhash2((u32 *)tuple, n,
  80                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  81                           tuple->dst.protonum));
  82
  83         return ((u64)h * size) >> 32;
  84 }
  85
  86 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  87 {
  88         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  89                                 nf_conntrack_hash_rnd);
  90 }
  91
  92 bool
  93 nf_ct_get_tuple(const struct sk_buff *skb,
  94                 unsigned int nhoff,
  95                 unsigned int dataoff,
  96                 u_int16_t l3num,
  97                 u_int8_t protonum,
  98                 struct nf_conntrack_tuple *tuple,
  99                 const struct nf_conntrack_l3proto *l3proto,
 100                 const struct nf_conntrack_l4proto *l4proto)
 101 {
 102         memset(tuple, 0, sizeof(*tuple));
 103
 104         tuple->src.l3num = l3num;
 105         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 106                 return false;
 107
 108         tuple->dst.protonum = protonum;
 109         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 110
 111         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 112 }
 113 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 114
 115 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 116                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 117 {
 118         struct nf_conntrack_l3proto *l3proto;
 119         struct nf_conntrack_l4proto *l4proto;
 120         unsigned int protoff;
 121         u_int8_t protonum;
 122         int ret;
 123
 124         rcu_read_lock();
 125
 126         l3proto = __nf_ct_l3proto_find(l3num);
 127         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 128         if (ret != NF_ACCEPT) {
 129                 rcu_read_unlock();
 130                 return false;
 131         }
 132
 133         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 134
 135         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 136                               l3proto, l4proto);
 137
 138         rcu_read_unlock();
 139         return ret;
 140 }
 141 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 142
 143 bool
 144 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 145                    const struct nf_conntrack_tuple *orig,
 146                    const struct nf_conntrack_l3proto *l3proto,
 147                    const struct nf_conntrack_l4proto *l4proto)
 148 {
 149         memset(inverse, 0, sizeof(*inverse));
 150
 151         inverse->src.l3num = orig->src.l3num;
 152         if (l3proto->invert_tuple(inverse, orig) == 0)
 153                 return false;
 154
 155         inverse->dst.dir = !orig->dst.dir;
 156
 157         inverse->dst.protonum = orig->dst.protonum;
 158         return l4proto->invert_tuple(inverse, orig);
 159 }
 160 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 161
 162 static void
 163 clean_from_lists(struct nf_conn *ct)
 164 {
 165         pr_debug("clean_from_lists(%p)\n", ct);
 166         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 167         hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
 168
 169         /* Destroy all pending expectations */
 170         nf_ct_remove_expectations(ct);
 171 }
 172
 173 static void
 174 destroy_conntrack(struct nf_conntrack *nfct)
 175 {
 176         struct nf_conn *ct = (struct nf_conn *)nfct;
 177         struct net *net = nf_ct_net(ct);
 178         struct nf_conntrack_l4proto *l4proto;
 179
 180         pr_debug("destroy_conntrack(%p)\n", ct);
 181         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 182         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 183
 184         if (!test_bit(IPS_DYING_BIT, &ct->status))
 185                 nf_conntrack_event(IPCT_DESTROY, ct);
 186         set_bit(IPS_DYING_BIT, &ct->status);
 187
 188         /* To make sure we don't get any weird locking issues here:
 189          * destroy_conntrack() MUST NOT be called with a write lock
 190          * to nf_conntrack_lock!!! -HW */
 191         rcu_read_lock();
 192         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 193         if (l4proto && l4proto->destroy)
 194                 l4proto->destroy(ct);
 195
 196         rcu_read_unlock();
 197
 198         spin_lock_bh(&nf_conntrack_lock);
 199         /* Expectations will have been removed in clean_from_lists,
 200          * except TFTP can create an expectation on the first packet,
 201          * before connection is in the list, so we need to clean here,
 202          * too. */
 203         nf_ct_remove_expectations(ct);
 204
 205         /* We overload first tuple to link into unconfirmed list. */
 206         if (!nf_ct_is_confirmed(ct)) {
 207                 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
 208                 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 209         }
 210
 211         NF_CT_STAT_INC(net, delete);
 212         spin_unlock_bh(&nf_conntrack_lock);
 213
 214         if (ct->master)
 215                 nf_ct_put(ct->master);
 216
 217         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 218         nf_conntrack_free(ct);
 219 }
 220
 221 static void death_by_timeout(unsigned long ul_conntrack)
 222 {
 223         struct nf_conn *ct = (void *)ul_conntrack;
 224         struct net *net = nf_ct_net(ct);
 225         struct nf_conn_help *help = nfct_help(ct);
 226         struct nf_conntrack_helper *helper;
 227
 228         if (help) {
 229                 rcu_read_lock();
 230                 helper = rcu_dereference(help->helper);
 231                 if (helper && helper->destroy)
 232                         helper->destroy(ct);
 233                 rcu_read_unlock();
 234         }
 235
 236         spin_lock_bh(&nf_conntrack_lock);
 237         /* Inside lock so preempt is disabled on module removal path.
 238          * Otherwise we can get spurious warnings. */
 239         NF_CT_STAT_INC(net, delete_list);
 240         clean_from_lists(ct);
 241         spin_unlock_bh(&nf_conntrack_lock);
 242         nf_ct_put(ct);
 243 }
 244
 245 struct nf_conntrack_tuple_hash *
 246 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 247 {
 248         struct nf_conntrack_tuple_hash *h;
 249         struct hlist_node *n;
 250         unsigned int hash = hash_conntrack(tuple);
 251
 252         /* Disable BHs the entire time since we normally need to disable them
 253          * at least once for the stats anyway.
 254          */
 255         local_bh_disable();
 256         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 257                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 258                         NF_CT_STAT_INC(net, found);
 259                         local_bh_enable();
 260                         return h;
 261                 }
 262                 NF_CT_STAT_INC(net, searched);
 263         }
 264         local_bh_enable();
 265
 266         return NULL;
 267 }
 268 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 269
 270 /* Find a connection corresponding to a tuple. */
 271 struct nf_conntrack_tuple_hash *
 272 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 273 {
 274         struct nf_conntrack_tuple_hash *h;
 275         struct nf_conn *ct;
 276
 277         rcu_read_lock();
 278         h = __nf_conntrack_find(net, tuple);
 279         if (h) {
 280                 ct = nf_ct_tuplehash_to_ctrack(h);
 281                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 282                         h = NULL;
 283         }
 284         rcu_read_unlock();
 285
 286         return h;
 287 }
 288 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 289
 290 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 291                                        unsigned int hash,
 292                                        unsigned int repl_hash)
 293 {
 294         struct net *net = nf_ct_net(ct);
 295
 296         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 297                            &net->ct.hash[hash]);
 298         hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
 299                            &net->ct.hash[repl_hash]);
 300 }
 301
 302 void nf_conntrack_hash_insert(struct nf_conn *ct)
 303 {
 304         unsigned int hash, repl_hash;
 305
 306         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 307         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 308
 309         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 310 }
 311 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 312
 313 /* Confirm a connection given skb; places it in hash table */
 314 int
 315 __nf_conntrack_confirm(struct sk_buff *skb)
 316 {
 317         unsigned int hash, repl_hash;
 318         struct nf_conntrack_tuple_hash *h;
 319         struct nf_conn *ct;
 320         struct nf_conn_help *help;
 321         struct hlist_node *n;
 322         enum ip_conntrack_info ctinfo;
 323         struct net *net;
 324
 325         ct = nf_ct_get(skb, &ctinfo);
 326         net = nf_ct_net(ct);
 327
 328         /* ipt_REJECT uses nf_conntrack_attach to attach related
 329            ICMP/TCP RST packets in other direction.  Actual packet
 330            which created connection will be IP_CT_NEW or for an
 331            expected connection, IP_CT_RELATED. */
 332         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 333                 return NF_ACCEPT;
 334
 335         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 336         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 337
 338         /* We're not in hash table, and we refuse to set up related
 339            connections for unconfirmed conns.  But packet copies and
 340            REJECT will give spurious warnings here. */
 341         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 342
 343         /* No external references means noone else could have
 344            confirmed us. */
 345         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 346         pr_debug("Confirming conntrack %p\n", ct);
 347
 348         spin_lock_bh(&nf_conntrack_lock);
 349
 350         /* See if there's one in the list already, including reverse:
 351            NAT could have grabbed it without realizing, since we're
 352            not in the hash.  If there is, we lost race. */
 353         hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode)
 354                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 355                                       &h->tuple))
 356                         goto out;
 357         hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode)
 358                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 359                                       &h->tuple))
 360                         goto out;
 361
 362         /* Remove from unconfirmed list */
 363         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 364
 365         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 366         /* Timer relative to confirmation time, not original
 367            setting time, otherwise we'd get timer wrap in
 368            weird delay cases. */
 369         ct->timeout.expires += jiffies;
 370         add_timer(&ct->timeout);
 371         atomic_inc(&ct->ct_general.use);
 372         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 373         NF_CT_STAT_INC(net, insert);
 374         spin_unlock_bh(&nf_conntrack_lock);
 375         help = nfct_help(ct);
 376         if (help && help->helper)
 377                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 378 #ifdef CONFIG_NF_NAT_NEEDED
 379         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 380             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 381                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
 382 #endif
 383         nf_conntrack_event_cache(master_ct(ct) ?
 384                                  IPCT_RELATED : IPCT_NEW, ct);
 385         return NF_ACCEPT;
 386
 387 out:
 388         NF_CT_STAT_INC(net, insert_failed);
 389         spin_unlock_bh(&nf_conntrack_lock);
 390         return NF_DROP;
 391 }
 392 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 393
 394 /* Returns true if a connection correspondings to the tuple (required
 395    for NAT). */
 396 int
 397 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 398                          const struct nf_conn *ignored_conntrack)
 399 {
 400         struct net *net = nf_ct_net(ignored_conntrack);
 401         struct nf_conntrack_tuple_hash *h;
 402         struct hlist_node *n;
 403         unsigned int hash = hash_conntrack(tuple);
 404
 405         /* Disable BHs the entire time since we need to disable them at
 406          * least once for the stats anyway.
 407          */
 408         rcu_read_lock_bh();
 409         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 410                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 411                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 412                         NF_CT_STAT_INC(net, found);
 413                         rcu_read_unlock_bh();
 414                         return 1;
 415                 }
 416                 NF_CT_STAT_INC(net, searched);
 417         }
 418         rcu_read_unlock_bh();
 419
 420         return 0;
 421 }
 422 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 423
 424 #define NF_CT_EVICTION_RANGE    8
 425
 426 /* There's a small race here where we may free a just-assured
 427    connection.  Too bad: we're in trouble anyway. */
 428 static noinline int early_drop(struct net *net, unsigned int hash)
 429 {
 430         /* Use oldest entry, which is roughly LRU */
 431         struct nf_conntrack_tuple_hash *h;
 432         struct nf_conn *ct = NULL, *tmp;
 433         struct hlist_node *n;
 434         unsigned int i, cnt = 0;
 435         int dropped = 0;
 436
 437         rcu_read_lock();
 438         for (i = 0; i < nf_conntrack_htable_size; i++) {
 439                 hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 440                                          hnode) {
 441                         tmp = nf_ct_tuplehash_to_ctrack(h);
 442                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 443                                 ct = tmp;
 444                         cnt++;
 445                 }
 446
 447                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 448                         ct = NULL;
 449                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 450                         break;
 451                 hash = (hash + 1) % nf_conntrack_htable_size;
 452         }
 453         rcu_read_unlock();
 454
 455         if (!ct)
 456                 return dropped;
 457
 458         if (del_timer(&ct->timeout)) {
 459                 death_by_timeout((unsigned long)ct);
 460                 dropped = 1;
 461                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
 462         }
 463         nf_ct_put(ct);
 464         return dropped;
 465 }
 466
 467 struct nf_conn *nf_conntrack_alloc(struct net *net,
 468                                    const struct nf_conntrack_tuple *orig,
 469                                    const struct nf_conntrack_tuple *repl,
 470                                    gfp_t gfp)
 471 {
 472         struct nf_conn *ct;
 473
 474         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 475                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 476                 nf_conntrack_hash_rnd_initted = 1;
 477         }
 478
 479         /* We don't want any race condition at early drop stage */
 480         atomic_inc(&net->ct.count);
 481
 482         if (nf_conntrack_max &&
 483             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 484                 unsigned int hash = hash_conntrack(orig);
 485                 if (!early_drop(net, hash)) {
 486                         atomic_dec(&net->ct.count);
 487                         if (net_ratelimit())
 488                                 printk(KERN_WARNING
 489                                        "nf_conntrack: table full, dropping"
 490                                        " packet.\n");
 491                         return ERR_PTR(-ENOMEM);
 492                 }
 493         }
 494
 495         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 496         if (ct == NULL) {
 497                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 498                 atomic_dec(&net->ct.count);
 499                 return ERR_PTR(-ENOMEM);
 500         }
 501
 502         atomic_set(&ct->ct_general.use, 1);
 503         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 504         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 505         /* Don't set timer yet: wait for confirmation */
 506         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 507 #ifdef CONFIG_NET_NS
 508         ct->ct_net = net;
 509 #endif
 510         INIT_RCU_HEAD(&ct->rcu);
 511
 512         return ct;
 513 }
 514 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 515
 516 static void nf_conntrack_free_rcu(struct rcu_head *head)
 517 {
 518         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 519         struct net *net = nf_ct_net(ct);
 520
 521         nf_ct_ext_free(ct);
 522         kmem_cache_free(nf_conntrack_cachep, ct);
 523         atomic_dec(&net->ct.count);
 524 }
 525
 526 void nf_conntrack_free(struct nf_conn *ct)
 527 {
 528         nf_ct_ext_destroy(ct);
 529         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 530 }
 531 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 532
 533 /* Allocate a new conntrack: we return -ENOMEM if classification
 534    failed due to stress.  Otherwise it really is unclassifiable. */
 535 static struct nf_conntrack_tuple_hash *
 536 init_conntrack(struct net *net,
 537                const struct nf_conntrack_tuple *tuple,
 538                struct nf_conntrack_l3proto *l3proto,
 539                struct nf_conntrack_l4proto *l4proto,
 540                struct sk_buff *skb,
 541                unsigned int dataoff)
 542 {
 543         struct nf_conn *ct;
 544         struct nf_conn_help *help;
 545         struct nf_conntrack_tuple repl_tuple;
 546         struct nf_conntrack_expect *exp;
 547
 548         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 549                 pr_debug("Can't invert tuple.\n");
 550                 return NULL;
 551         }
 552
 553         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 554         if (IS_ERR(ct)) {
 555                 pr_debug("Can't allocate conntrack.\n");
 556                 return (struct nf_conntrack_tuple_hash *)ct;
 557         }
 558
 559         if (!l4proto->new(ct, skb, dataoff)) {
 560                 nf_conntrack_free(ct);
 561                 pr_debug("init conntrack: can't track with proto module\n");
 562                 return NULL;
 563         }
 564
 565         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 566
 567         spin_lock_bh(&nf_conntrack_lock);
 568         exp = nf_ct_find_expectation(net, tuple);
 569         if (exp) {
 570                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 571                          ct, exp);
 572                 /* Welcome, Mr. Bond.  We've been expecting you... */
 573                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 574                 ct->master = exp->master;
 575                 if (exp->helper) {
 576                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 577                         if (help)
 578                                 rcu_assign_pointer(help->helper, exp->helper);
 579                 }
 580
 581 #ifdef CONFIG_NF_CONNTRACK_MARK
 582                 ct->mark = exp->master->mark;
 583 #endif
 584 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 585                 ct->secmark = exp->master->secmark;
 586 #endif
 587                 nf_conntrack_get(&ct->master->ct_general);
 588                 NF_CT_STAT_INC(net, expect_new);
 589         } else {
 590                 __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 591                 NF_CT_STAT_INC(net, new);
 592         }
 593
 594         /* Overload tuple linked list to put us in unconfirmed list. */
 595         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 596                        &net->ct.unconfirmed);
 597
 598         spin_unlock_bh(&nf_conntrack_lock);
 599
 600         if (exp) {
 601                 if (exp->expectfn)
 602                         exp->expectfn(ct, exp);
 603                 nf_ct_expect_put(exp);
 604         }
 605
 606         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 607 }
 608
 609 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 610 static inline struct nf_conn *
 611 resolve_normal_ct(struct net *net,
 612                   struct sk_buff *skb,
 613                   unsigned int dataoff,
 614                   u_int16_t l3num,
 615                   u_int8_t protonum,
 616                   struct nf_conntrack_l3proto *l3proto,
 617                   struct nf_conntrack_l4proto *l4proto,
 618                   int *set_reply,
 619                   enum ip_conntrack_info *ctinfo)
 620 {
 621         struct nf_conntrack_tuple tuple;
 622         struct nf_conntrack_tuple_hash *h;
 623         struct nf_conn *ct;
 624
 625         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 626                              dataoff, l3num, protonum, &tuple, l3proto,
 627                              l4proto)) {
 628                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 629                 return NULL;
 630         }
 631
 632         /* look for tuple match */
 633         h = nf_conntrack_find_get(net, &tuple);
 634         if (!h) {
 635                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
 636                 if (!h)
 637                         return NULL;
 638                 if (IS_ERR(h))
 639                         return (void *)h;
 640         }
 641         ct = nf_ct_tuplehash_to_ctrack(h);
 642
 643         /* It exists; we have (non-exclusive) reference. */
 644         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 645                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 646                 /* Please set reply bit if this packet OK */
 647                 *set_reply = 1;
 648         } else {
 649                 /* Once we've had two way comms, always ESTABLISHED. */
 650                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 651                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 652                         *ctinfo = IP_CT_ESTABLISHED;
 653                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 654                         pr_debug("nf_conntrack_in: related packet for %p\n",
 655                                  ct);
 656                         *ctinfo = IP_CT_RELATED;
 657                 } else {
 658                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 659                         *ctinfo = IP_CT_NEW;
 660                 }
 661                 *set_reply = 0;
 662         }
 663         skb->nfct = &ct->ct_general;
 664         skb->nfctinfo = *ctinfo;
 665         return ct;
 666 }
 667
 668 unsigned int
 669 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
 670                 struct sk_buff *skb)
 671 {
 672         struct nf_conn *ct;
 673         enum ip_conntrack_info ctinfo;
 674         struct nf_conntrack_l3proto *l3proto;
 675         struct nf_conntrack_l4proto *l4proto;
 676         unsigned int dataoff;
 677         u_int8_t protonum;
 678         int set_reply = 0;
 679         int ret;
 680
 681         /* Previously seen (loopback or untracked)?  Ignore. */
 682         if (skb->nfct) {
 683                 NF_CT_STAT_INC_ATOMIC(net, ignore);
 684                 return NF_ACCEPT;
 685         }
 686
 687         /* rcu_read_lock()ed by nf_hook_slow */
 688         l3proto = __nf_ct_l3proto_find(pf);
 689         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 690                                    &dataoff, &protonum);
 691         if (ret <= 0) {
 692                 pr_debug("not prepared to track yet or error occured\n");
 693                 NF_CT_STAT_INC_ATOMIC(net, error);
 694                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 695                 return -ret;
 696         }
 697
 698         l4proto = __nf_ct_l4proto_find(pf, protonum);
 699
 700         /* It may be an special packet, error, unclean...
 701          * inverse of the return code tells to the netfilter
 702          * core what to do with the packet. */
 703         if (l4proto->error != NULL) {
 704                 ret = l4proto->error(net, skb, dataoff, &ctinfo, pf, hooknum);
 705                 if (ret <= 0) {
 706                         NF_CT_STAT_INC_ATOMIC(net, error);
 707                         NF_CT_STAT_INC_ATOMIC(net, invalid);
 708                         return -ret;
 709                 }
 710         }
 711
 712         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
 713                                l3proto, l4proto, &set_reply, &ctinfo);
 714         if (!ct) {
 715                 /* Not valid part of a connection */
 716                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 717                 return NF_ACCEPT;
 718         }
 719
 720         if (IS_ERR(ct)) {
 721                 /* Too stressed to deal. */
 722                 NF_CT_STAT_INC_ATOMIC(net, 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(net, 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, ct);
 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
 768         /* Should be unconfirmed, so not in hash table yet */
 769         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 770
 771         pr_debug("Altering reply tuple of %p to ", ct);
 772         nf_ct_dump_tuple(newreply);
 773
 774         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 775         if (ct->master || (help && !hlist_empty(&help->expectations)))
 776                 return;
 777
 778         rcu_read_lock();
 779         __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 780         rcu_read_unlock();
 781 }
 782 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 783
 784 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 785 void __nf_ct_refresh_acct(struct nf_conn *ct,
 786                           enum ip_conntrack_info ctinfo,
 787                           const struct sk_buff *skb,
 788                           unsigned long extra_jiffies,
 789                           int do_acct)
 790 {
 791         int event = 0;
 792
 793         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 794         NF_CT_ASSERT(skb);
 795
 796         spin_lock_bh(&nf_conntrack_lock);
 797
 798         /* Only update if this is not a fixed timeout */
 799         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 800                 goto acct;
 801
 802         /* If not in hash table, timer will not be active yet */
 803         if (!nf_ct_is_confirmed(ct)) {
 804                 ct->timeout.expires = extra_jiffies;
 805                 event = IPCT_REFRESH;
 806         } else {
 807                 unsigned long newtime = jiffies + extra_jiffies;
 808
 809                 /* Only update the timeout if the new timeout is at least
 810                    HZ jiffies from the old timeout. Need del_timer for race
 811                    avoidance (may already be dying). */
 812                 if (newtime - ct->timeout.expires >= HZ
 813                     && del_timer(&ct->timeout)) {
 814                         ct->timeout.expires = newtime;
 815                         add_timer(&ct->timeout);
 816                         event = IPCT_REFRESH;
 817                 }
 818         }
 819
 820 acct:
 821         if (do_acct) {
 822                 struct nf_conn_counter *acct;
 823
 824                 acct = nf_conn_acct_find(ct);
 825                 if (acct) {
 826                         acct[CTINFO2DIR(ctinfo)].packets++;
 827                         acct[CTINFO2DIR(ctinfo)].bytes +=
 828                                 skb->len - skb_network_offset(skb);
 829                 }
 830         }
 831
 832         spin_unlock_bh(&nf_conntrack_lock);
 833
 834         /* must be unlocked when calling event cache */
 835         if (event)
 836                 nf_conntrack_event_cache(event, ct);
 837 }
 838 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 839
 840 bool __nf_ct_kill_acct(struct nf_conn *ct,
 841                        enum ip_conntrack_info ctinfo,
 842                        const struct sk_buff *skb,
 843                        int do_acct)
 844 {
 845         if (do_acct) {
 846                 struct nf_conn_counter *acct;
 847
 848                 spin_lock_bh(&nf_conntrack_lock);
 849                 acct = nf_conn_acct_find(ct);
 850                 if (acct) {
 851                         acct[CTINFO2DIR(ctinfo)].packets++;
 852                         acct[CTINFO2DIR(ctinfo)].bytes +=
 853                                 skb->len - skb_network_offset(skb);
 854                 }
 855                 spin_unlock_bh(&nf_conntrack_lock);
 856         }
 857
 858         if (del_timer(&ct->timeout)) {
 859                 ct->timeout.function((unsigned long)ct);
 860                 return true;
 861         }
 862         return false;
 863 }
 864 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 865
 866 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 867
 868 #include <linux/netfilter/nfnetlink.h>
 869 #include <linux/netfilter/nfnetlink_conntrack.h>
 870 #include <linux/mutex.h>
 871
 872 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 873  * in ip_conntrack_core, since we don't want the protocols to autoload
 874  * or depend on ctnetlink */
 875 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 876                                const struct nf_conntrack_tuple *tuple)
 877 {
 878         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 879         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 880         return 0;
 881
 882 nla_put_failure:
 883         return -1;
 884 }
 885 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 886
 887 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 888         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 889         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 890 };
 891 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 892
 893 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 894                                struct nf_conntrack_tuple *t)
 895 {
 896         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 897                 return -EINVAL;
 898
 899         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 900         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 901
 902         return 0;
 903 }
 904 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 905 #endif
 906
 907 /* Used by ipt_REJECT and ip6t_REJECT. */
 908 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 909 {
 910         struct nf_conn *ct;
 911         enum ip_conntrack_info ctinfo;
 912
 913         /* This ICMP is in reverse direction to the packet which caused it */
 914         ct = nf_ct_get(skb, &ctinfo);
 915         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 916                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 917         else
 918                 ctinfo = IP_CT_RELATED;
 919
 920         /* Attach to new skbuff, and increment count */
 921         nskb->nfct = &ct->ct_general;
 922         nskb->nfctinfo = ctinfo;
 923         nf_conntrack_get(nskb->nfct);
 924 }
 925
 926 /* Bring out ya dead! */
 927 static struct nf_conn *
 928 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 929                 void *data, unsigned int *bucket)
 930 {
 931         struct nf_conntrack_tuple_hash *h;
 932         struct nf_conn *ct;
 933         struct hlist_node *n;
 934
 935         spin_lock_bh(&nf_conntrack_lock);
 936         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 937                 hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) {
 938                         ct = nf_ct_tuplehash_to_ctrack(h);
 939                         if (iter(ct, data))
 940                                 goto found;
 941                 }
 942         }
 943         hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) {
 944                 ct = nf_ct_tuplehash_to_ctrack(h);
 945                 if (iter(ct, data))
 946                         set_bit(IPS_DYING_BIT, &ct->status);
 947         }
 948         spin_unlock_bh(&nf_conntrack_lock);
 949         return NULL;
 950 found:
 951         atomic_inc(&ct->ct_general.use);
 952         spin_unlock_bh(&nf_conntrack_lock);
 953         return ct;
 954 }
 955
 956 void nf_ct_iterate_cleanup(struct net *net,
 957                            int (*iter)(struct nf_conn *i, void *data),
 958                            void *data)
 959 {
 960         struct nf_conn *ct;
 961         unsigned int bucket = 0;
 962
 963         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 964                 /* Time to push up daises... */
 965                 if (del_timer(&ct->timeout))
 966                         death_by_timeout((unsigned long)ct);
 967                 /* ... else the timer will get him soon. */
 968
 969                 nf_ct_put(ct);
 970         }
 971 }
 972 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 973
 974 struct __nf_ct_flush_report {
 975         u32 pid;
 976         int report;
 977 };
 978
 979 static int kill_all(struct nf_conn *i, void *data)
 980 {
 981         struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
 982
 983         /* get_next_corpse sets the dying bit for us */
 984         nf_conntrack_event_report(IPCT_DESTROY,
 985                                   i,
 986                                   fr->pid,
 987                                   fr->report);
 988         return 1;
 989 }
 990
 991 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 992 {
 993         if (vmalloced)
 994                 vfree(hash);
 995         else
 996                 free_pages((unsigned long)hash,
 997                            get_order(sizeof(struct hlist_head) * size));
 998 }
 999 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1000
1001 void nf_conntrack_flush(struct net *net, u32 pid, int report)
1002 {
1003         struct __nf_ct_flush_report fr = {
1004                 .pid    = pid,
1005                 .report = report,
1006         };
1007         nf_ct_iterate_cleanup(net, kill_all, &fr);
1008 }
1009 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1010
1011 static void nf_conntrack_cleanup_init_net(void)
1012 {
1013         nf_conntrack_helper_fini();
1014         nf_conntrack_proto_fini();
1015         kmem_cache_destroy(nf_conntrack_cachep);
1016 }
1017
1018 static void nf_conntrack_cleanup_net(struct net *net)
1019 {
1020         nf_ct_event_cache_flush(net);
1021         nf_conntrack_ecache_fini(net);
1022  i_see_dead_people:
1023         nf_conntrack_flush(net, 0, 0);
1024         if (atomic_read(&net->ct.count) != 0) {
1025                 schedule();
1026                 goto i_see_dead_people;
1027         }
1028         /* wait until all references to nf_conntrack_untracked are dropped */
1029         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1030                 schedule();
1031
1032         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1033                              nf_conntrack_htable_size);
1034         nf_conntrack_acct_fini(net);
1035         nf_conntrack_expect_fini(net);
1036         free_percpu(net->ct.stat);
1037 }
1038
1039 /* Mishearing the voices in his head, our hero wonders how he's
1040    supposed to kill the mall. */
1041 void nf_conntrack_cleanup(struct net *net)
1042 {
1043         if (net_eq(net, &init_net))
1044                 rcu_assign_pointer(ip_ct_attach, NULL);
1045
1046         /* This makes sure all current packets have passed through
1047            netfilter framework.  Roll on, two-stage module
1048            delete... */
1049         synchronize_net();
1050
1051         nf_conntrack_cleanup_net(net);
1052
1053         if (net_eq(net, &init_net)) {
1054                 rcu_assign_pointer(nf_ct_destroy, NULL);
1055                 nf_conntrack_cleanup_init_net();
1056         }
1057 }
1058
1059 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1060 {
1061         struct hlist_head *hash;
1062         unsigned int size, i;
1063
1064         *vmalloced = 0;
1065
1066         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1067         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1068                                        get_order(sizeof(struct hlist_head)
1069                                                  * size));
1070         if (!hash) {
1071                 *vmalloced = 1;
1072                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1073                 hash = vmalloc(sizeof(struct hlist_head) * size);
1074         }
1075
1076         if (hash)
1077                 for (i = 0; i < size; i++)
1078                         INIT_HLIST_HEAD(&hash[i]);
1079
1080         return hash;
1081 }
1082 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1083
1084 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1085 {
1086         int i, bucket, vmalloced, old_vmalloced;
1087         unsigned int hashsize, old_size;
1088         int rnd;
1089         struct hlist_head *hash, *old_hash;
1090         struct nf_conntrack_tuple_hash *h;
1091
1092         /* On boot, we can set this without any fancy locking. */
1093         if (!nf_conntrack_htable_size)
1094                 return param_set_uint(val, kp);
1095
1096         hashsize = simple_strtoul(val, NULL, 0);
1097         if (!hashsize)
1098                 return -EINVAL;
1099
1100         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1101         if (!hash)
1102                 return -ENOMEM;
1103
1104         /* We have to rehahs for the new table anyway, so we also can
1105          * use a newrandom seed */
1106         get_random_bytes(&rnd, 4);
1107
1108         /* Lookups in the old hash might happen in parallel, which means we
1109          * might get false negatives during connection lookup. New connections
1110          * created because of a false negative won't make it into the hash
1111          * though since that required taking the lock.
1112          */
1113         spin_lock_bh(&nf_conntrack_lock);
1114         for (i = 0; i < nf_conntrack_htable_size; i++) {
1115                 while (!hlist_empty(&init_net.ct.hash[i])) {
1116                         h = hlist_entry(init_net.ct.hash[i].first,
1117                                         struct nf_conntrack_tuple_hash, hnode);
1118                         hlist_del_rcu(&h->hnode);
1119                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1120                         hlist_add_head(&h->hnode, &hash[bucket]);
1121                 }
1122         }
1123         old_size = nf_conntrack_htable_size;
1124         old_vmalloced = init_net.ct.hash_vmalloc;
1125         old_hash = init_net.ct.hash;
1126
1127         nf_conntrack_htable_size = hashsize;
1128         init_net.ct.hash_vmalloc = vmalloced;
1129         init_net.ct.hash = hash;
1130         nf_conntrack_hash_rnd = rnd;
1131         spin_unlock_bh(&nf_conntrack_lock);
1132
1133         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1134         return 0;
1135 }
1136 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1137
1138 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1139                   &nf_conntrack_htable_size, 0600);
1140
1141 static int nf_conntrack_init_init_net(void)
1142 {
1143         int max_factor = 8;
1144         int ret;
1145
1146         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1147          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1148         if (!nf_conntrack_htable_size) {
1149                 nf_conntrack_htable_size
1150                         = (((num_physpages << PAGE_SHIFT) / 16384)
1151                            / sizeof(struct hlist_head));
1152                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1153                         nf_conntrack_htable_size = 16384;
1154                 if (nf_conntrack_htable_size < 32)
1155                         nf_conntrack_htable_size = 32;
1156
1157                 /* Use a max. factor of four by default to get the same max as
1158                  * with the old struct list_heads. When a table size is given
1159                  * we use the old value of 8 to avoid reducing the max.
1160                  * entries. */
1161                 max_factor = 4;
1162         }
1163         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1164
1165         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1166                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1167                nf_conntrack_max);
1168
1169         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1170                                                 sizeof(struct nf_conn),
1171                                                 0, 0, NULL);
1172         if (!nf_conntrack_cachep) {
1173                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1174                 ret = -ENOMEM;
1175                 goto err_cache;
1176         }
1177
1178         ret = nf_conntrack_proto_init();
1179         if (ret < 0)
1180                 goto err_proto;
1181
1182         ret = nf_conntrack_helper_init();
1183         if (ret < 0)
1184                 goto err_helper;
1185
1186         return 0;
1187
1188 err_helper:
1189         nf_conntrack_proto_fini();
1190 err_proto:
1191         kmem_cache_destroy(nf_conntrack_cachep);
1192 err_cache:
1193         return ret;
1194 }
1195
1196 static int nf_conntrack_init_net(struct net *net)
1197 {
1198         int ret;
1199
1200         atomic_set(&net->ct.count, 0);
1201         INIT_HLIST_HEAD(&net->ct.unconfirmed);
1202         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1203         if (!net->ct.stat) {
1204                 ret = -ENOMEM;
1205                 goto err_stat;
1206         }
1207         ret = nf_conntrack_ecache_init(net);
1208         if (ret < 0)
1209                 goto err_ecache;
1210         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1211                                                   &net->ct.hash_vmalloc);
1212         if (!net->ct.hash) {
1213                 ret = -ENOMEM;
1214                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1215                 goto err_hash;
1216         }
1217         ret = nf_conntrack_expect_init(net);
1218         if (ret < 0)
1219                 goto err_expect;
1220         ret = nf_conntrack_acct_init(net);
1221         if (ret < 0)
1222                 goto err_acct;
1223
1224         /* Set up fake conntrack:
1225             - to never be deleted, not in any hashes */
1226 #ifdef CONFIG_NET_NS
1227         nf_conntrack_untracked.ct_net = &init_net;
1228 #endif
1229         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1230         /*  - and look it like as a confirmed connection */
1231         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1232
1233         return 0;
1234
1235 err_acct:
1236         nf_conntrack_expect_fini(net);
1237 err_expect:
1238         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1239                              nf_conntrack_htable_size);
1240 err_hash:
1241         nf_conntrack_ecache_fini(net);
1242 err_ecache:
1243         free_percpu(net->ct.stat);
1244 err_stat:
1245         return ret;
1246 }
1247
1248 int nf_conntrack_init(struct net *net)
1249 {
1250         int ret;
1251
1252         if (net_eq(net, &init_net)) {
1253                 ret = nf_conntrack_init_init_net();
1254                 if (ret < 0)
1255                         goto out_init_net;
1256         }
1257         ret = nf_conntrack_init_net(net);
1258         if (ret < 0)
1259                 goto out_net;
1260
1261         if (net_eq(net, &init_net)) {
1262                 /* For use by REJECT target */
1263                 rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1264                 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1265         }
1266         return 0;
1267
1268 out_net:
1269         if (net_eq(net, &init_net))
1270                 nf_conntrack_cleanup_init_net();
1271 out_init_net:
1272         return ret;
1273 }