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 #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         spin_lock_bh(&nf_conntrack_lock);
 310         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 311         spin_unlock_bh(&nf_conntrack_lock);
 312 }
 313 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 314
 315 /* Confirm a connection given skb; places it in hash table */
 316 int
 317 __nf_conntrack_confirm(struct sk_buff *skb)
 318 {
 319         unsigned int hash, repl_hash;
 320         struct nf_conntrack_tuple_hash *h;
 321         struct nf_conn *ct;
 322         struct nf_conn_help *help;
 323         struct hlist_node *n;
 324         enum ip_conntrack_info ctinfo;
 325         struct net *net;
 326
 327         ct = nf_ct_get(skb, &ctinfo);
 328         net = nf_ct_net(ct);
 329
 330         /* ipt_REJECT uses nf_conntrack_attach to attach related
 331            ICMP/TCP RST packets in other direction.  Actual packet
 332            which created connection will be IP_CT_NEW or for an
 333            expected connection, IP_CT_RELATED. */
 334         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 335                 return NF_ACCEPT;
 336
 337         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 338         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 339
 340         /* We're not in hash table, and we refuse to set up related
 341            connections for unconfirmed conns.  But packet copies and
 342            REJECT will give spurious warnings here. */
 343         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 344
 345         /* No external references means noone else could have
 346            confirmed us. */
 347         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 348         pr_debug("Confirming conntrack %p\n", ct);
 349
 350         spin_lock_bh(&nf_conntrack_lock);
 351
 352         /* See if there's one in the list already, including reverse:
 353            NAT could have grabbed it without realizing, since we're
 354            not in the hash.  If there is, we lost race. */
 355         hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode)
 356                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 357                                       &h->tuple))
 358                         goto out;
 359         hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode)
 360                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 361                                       &h->tuple))
 362                         goto out;
 363
 364         /* Remove from unconfirmed list */
 365         hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
 366
 367         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 368         /* Timer relative to confirmation time, not original
 369            setting time, otherwise we'd get timer wrap in
 370            weird delay cases. */
 371         ct->timeout.expires += jiffies;
 372         add_timer(&ct->timeout);
 373         atomic_inc(&ct->ct_general.use);
 374         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 375         NF_CT_STAT_INC(net, insert);
 376         spin_unlock_bh(&nf_conntrack_lock);
 377         help = nfct_help(ct);
 378         if (help && help->helper)
 379                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 380 #ifdef CONFIG_NF_NAT_NEEDED
 381         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 382             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 383                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
 384 #endif
 385         nf_conntrack_event_cache(master_ct(ct) ?
 386                                  IPCT_RELATED : IPCT_NEW, ct);
 387         return NF_ACCEPT;
 388
 389 out:
 390         NF_CT_STAT_INC(net, insert_failed);
 391         spin_unlock_bh(&nf_conntrack_lock);
 392         return NF_DROP;
 393 }
 394 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 395
 396 /* Returns true if a connection correspondings to the tuple (required
 397    for NAT). */
 398 int
 399 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 400                          const struct nf_conn *ignored_conntrack)
 401 {
 402         struct net *net = nf_ct_net(ignored_conntrack);
 403         struct nf_conntrack_tuple_hash *h;
 404         struct hlist_node *n;
 405         unsigned int hash = hash_conntrack(tuple);
 406
 407         /* Disable BHs the entire time since we need to disable them at
 408          * least once for the stats anyway.
 409          */
 410         rcu_read_lock_bh();
 411         hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) {
 412                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 413                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 414                         NF_CT_STAT_INC(net, found);
 415                         rcu_read_unlock_bh();
 416                         return 1;
 417                 }
 418                 NF_CT_STAT_INC(net, searched);
 419         }
 420         rcu_read_unlock_bh();
 421
 422         return 0;
 423 }
 424 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 425
 426 #define NF_CT_EVICTION_RANGE    8
 427
 428 /* There's a small race here where we may free a just-assured
 429    connection.  Too bad: we're in trouble anyway. */
 430 static noinline int early_drop(struct net *net, unsigned int hash)
 431 {
 432         /* Use oldest entry, which is roughly LRU */
 433         struct nf_conntrack_tuple_hash *h;
 434         struct nf_conn *ct = NULL, *tmp;
 435         struct hlist_node *n;
 436         unsigned int i, cnt = 0;
 437         int dropped = 0;
 438
 439         rcu_read_lock();
 440         for (i = 0; i < nf_conntrack_htable_size; i++) {
 441                 hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 442                                          hnode) {
 443                         tmp = nf_ct_tuplehash_to_ctrack(h);
 444                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 445                                 ct = tmp;
 446                         cnt++;
 447                 }
 448
 449                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 450                         ct = NULL;
 451                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 452                         break;
 453                 hash = (hash + 1) % nf_conntrack_htable_size;
 454         }
 455         rcu_read_unlock();
 456
 457         if (!ct)
 458                 return dropped;
 459
 460         if (del_timer(&ct->timeout)) {
 461                 death_by_timeout((unsigned long)ct);
 462                 dropped = 1;
 463                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
 464         }
 465         nf_ct_put(ct);
 466         return dropped;
 467 }
 468
 469 struct nf_conn *nf_conntrack_alloc(struct net *net,
 470                                    const struct nf_conntrack_tuple *orig,
 471                                    const struct nf_conntrack_tuple *repl,
 472                                    gfp_t gfp)
 473 {
 474         struct nf_conn *ct = NULL;
 475
 476         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 477                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 478                 nf_conntrack_hash_rnd_initted = 1;
 479         }
 480
 481         /* We don't want any race condition at early drop stage */
 482         atomic_inc(&net->ct.count);
 483
 484         if (nf_conntrack_max &&
 485             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 486                 unsigned int hash = hash_conntrack(orig);
 487                 if (!early_drop(net, hash)) {
 488                         atomic_dec(&net->ct.count);
 489                         if (net_ratelimit())
 490                                 printk(KERN_WARNING
 491                                        "nf_conntrack: table full, dropping"
 492                                        " packet.\n");
 493                         return ERR_PTR(-ENOMEM);
 494                 }
 495         }
 496
 497         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 498         if (ct == NULL) {
 499                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 500                 atomic_dec(&net->ct.count);
 501                 return ERR_PTR(-ENOMEM);
 502         }
 503
 504         atomic_set(&ct->ct_general.use, 1);
 505         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 506         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 507         /* Don't set timer yet: wait for confirmation */
 508         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 509 #ifdef CONFIG_NET_NS
 510         ct->ct_net = net;
 511 #endif
 512         INIT_RCU_HEAD(&ct->rcu);
 513
 514         return ct;
 515 }
 516 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 517
 518 static void nf_conntrack_free_rcu(struct rcu_head *head)
 519 {
 520         struct nf_conn *ct = container_of(head, struct nf_conn, rcu);
 521         struct net *net = nf_ct_net(ct);
 522
 523         nf_ct_ext_free(ct);
 524         kmem_cache_free(nf_conntrack_cachep, ct);
 525         atomic_dec(&net->ct.count);
 526 }
 527
 528 void nf_conntrack_free(struct nf_conn *ct)
 529 {
 530         nf_ct_ext_destroy(ct);
 531         call_rcu(&ct->rcu, nf_conntrack_free_rcu);
 532 }
 533 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 534
 535 /* Allocate a new conntrack: we return -ENOMEM if classification
 536    failed due to stress.  Otherwise it really is unclassifiable. */
 537 static struct nf_conntrack_tuple_hash *
 538 init_conntrack(struct net *net,
 539                const struct nf_conntrack_tuple *tuple,
 540                struct nf_conntrack_l3proto *l3proto,
 541                struct nf_conntrack_l4proto *l4proto,
 542                struct sk_buff *skb,
 543                unsigned int dataoff)
 544 {
 545         struct nf_conn *ct;
 546         struct nf_conn_help *help;
 547         struct nf_conntrack_tuple repl_tuple;
 548         struct nf_conntrack_expect *exp;
 549
 550         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 551                 pr_debug("Can't invert tuple.\n");
 552                 return NULL;
 553         }
 554
 555         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 556         if (ct == NULL || IS_ERR(ct)) {
 557                 pr_debug("Can't allocate conntrack.\n");
 558                 return (struct nf_conntrack_tuple_hash *)ct;
 559         }
 560
 561         if (!l4proto->new(ct, skb, dataoff)) {
 562                 nf_conntrack_free(ct);
 563                 pr_debug("init conntrack: can't track with proto module\n");
 564                 return NULL;
 565         }
 566
 567         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 568
 569         spin_lock_bh(&nf_conntrack_lock);
 570         exp = nf_ct_find_expectation(net, tuple);
 571         if (exp) {
 572                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 573                          ct, exp);
 574                 /* Welcome, Mr. Bond.  We've been expecting you... */
 575                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 576                 ct->master = exp->master;
 577                 if (exp->helper) {
 578                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 579                         if (help)
 580                                 rcu_assign_pointer(help->helper, exp->helper);
 581                 }
 582
 583 #ifdef CONFIG_NF_CONNTRACK_MARK
 584                 ct->mark = exp->master->mark;
 585 #endif
 586 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 587                 ct->secmark = exp->master->secmark;
 588 #endif
 589                 nf_conntrack_get(&ct->master->ct_general);
 590                 NF_CT_STAT_INC(net, expect_new);
 591         } else {
 592                 __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 593                 NF_CT_STAT_INC(net, new);
 594         }
 595
 596         /* Overload tuple linked list to put us in unconfirmed list. */
 597         hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
 598                        &net->ct.unconfirmed);
 599
 600         spin_unlock_bh(&nf_conntrack_lock);
 601
 602         if (exp) {
 603                 if (exp->expectfn)
 604                         exp->expectfn(ct, exp);
 605                 nf_ct_expect_put(exp);
 606         }
 607
 608         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 609 }
 610
 611 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 612 static inline struct nf_conn *
 613 resolve_normal_ct(struct net *net,
 614                   struct sk_buff *skb,
 615                   unsigned int dataoff,
 616                   u_int16_t l3num,
 617                   u_int8_t protonum,
 618                   struct nf_conntrack_l3proto *l3proto,
 619                   struct nf_conntrack_l4proto *l4proto,
 620                   int *set_reply,
 621                   enum ip_conntrack_info *ctinfo)
 622 {
 623         struct nf_conntrack_tuple tuple;
 624         struct nf_conntrack_tuple_hash *h;
 625         struct nf_conn *ct;
 626
 627         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 628                              dataoff, l3num, protonum, &tuple, l3proto,
 629                              l4proto)) {
 630                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 631                 return NULL;
 632         }
 633
 634         /* look for tuple match */
 635         h = nf_conntrack_find_get(net, &tuple);
 636         if (!h) {
 637                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
 638                 if (!h)
 639                         return NULL;
 640                 if (IS_ERR(h))
 641                         return (void *)h;
 642         }
 643         ct = nf_ct_tuplehash_to_ctrack(h);
 644
 645         /* It exists; we have (non-exclusive) reference. */
 646         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 647                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 648                 /* Please set reply bit if this packet OK */
 649                 *set_reply = 1;
 650         } else {
 651                 /* Once we've had two way comms, always ESTABLISHED. */
 652                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 653                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 654                         *ctinfo = IP_CT_ESTABLISHED;
 655                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 656                         pr_debug("nf_conntrack_in: related packet for %p\n",
 657                                  ct);
 658                         *ctinfo = IP_CT_RELATED;
 659                 } else {
 660                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 661                         *ctinfo = IP_CT_NEW;
 662                 }
 663                 *set_reply = 0;
 664         }
 665         skb->nfct = &ct->ct_general;
 666         skb->nfctinfo = *ctinfo;
 667         return ct;
 668 }
 669
 670 unsigned int
 671 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
 672                 struct sk_buff *skb)
 673 {
 674         struct nf_conn *ct;
 675         enum ip_conntrack_info ctinfo;
 676         struct nf_conntrack_l3proto *l3proto;
 677         struct nf_conntrack_l4proto *l4proto;
 678         unsigned int dataoff;
 679         u_int8_t protonum;
 680         int set_reply = 0;
 681         int ret;
 682
 683         /* Previously seen (loopback or untracked)?  Ignore. */
 684         if (skb->nfct) {
 685                 NF_CT_STAT_INC_ATOMIC(net, ignore);
 686                 return NF_ACCEPT;
 687         }
 688
 689         /* rcu_read_lock()ed by nf_hook_slow */
 690         l3proto = __nf_ct_l3proto_find(pf);
 691         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 692                                    &dataoff, &protonum);
 693         if (ret <= 0) {
 694                 pr_debug("not prepared to track yet or error occured\n");
 695                 NF_CT_STAT_INC_ATOMIC(net, error);
 696                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 697                 return -ret;
 698         }
 699
 700         l4proto = __nf_ct_l4proto_find(pf, protonum);
 701
 702         /* It may be an special packet, error, unclean...
 703          * inverse of the return code tells to the netfilter
 704          * core what to do with the packet. */
 705         if (l4proto->error != NULL) {
 706                 ret = l4proto->error(net, skb, dataoff, &ctinfo, pf, hooknum);
 707                 if (ret <= 0) {
 708                         NF_CT_STAT_INC_ATOMIC(net, error);
 709                         NF_CT_STAT_INC_ATOMIC(net, invalid);
 710                         return -ret;
 711                 }
 712         }
 713
 714         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
 715                                l3proto, l4proto, &set_reply, &ctinfo);
 716         if (!ct) {
 717                 /* Not valid part of a connection */
 718                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 719                 return NF_ACCEPT;
 720         }
 721
 722         if (IS_ERR(ct)) {
 723                 /* Too stressed to deal. */
 724                 NF_CT_STAT_INC_ATOMIC(net, drop);
 725                 return NF_DROP;
 726         }
 727
 728         NF_CT_ASSERT(skb->nfct);
 729
 730         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 731         if (ret < 0) {
 732                 /* Invalid: inverse of the return code tells
 733                  * the netfilter core what to do */
 734                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 735                 nf_conntrack_put(skb->nfct);
 736                 skb->nfct = NULL;
 737                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 738                 return -ret;
 739         }
 740
 741         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 742                 nf_conntrack_event_cache(IPCT_STATUS, ct);
 743
 744         return ret;
 745 }
 746 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 747
 748 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 749                           const struct nf_conntrack_tuple *orig)
 750 {
 751         bool ret;
 752
 753         rcu_read_lock();
 754         ret = nf_ct_invert_tuple(inverse, orig,
 755                                  __nf_ct_l3proto_find(orig->src.l3num),
 756                                  __nf_ct_l4proto_find(orig->src.l3num,
 757                                                       orig->dst.protonum));
 758         rcu_read_unlock();
 759         return ret;
 760 }
 761 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 762
 763 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 764    implicitly racy: see __nf_conntrack_confirm */
 765 void nf_conntrack_alter_reply(struct nf_conn *ct,
 766                               const struct nf_conntrack_tuple *newreply)
 767 {
 768         struct nf_conn_help *help = nfct_help(ct);
 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         __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 782         rcu_read_unlock();
 783 }
 784 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 785
 786 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 787 void __nf_ct_refresh_acct(struct nf_conn *ct,
 788                           enum ip_conntrack_info ctinfo,
 789                           const struct sk_buff *skb,
 790                           unsigned long extra_jiffies,
 791                           int do_acct)
 792 {
 793         int event = 0;
 794
 795         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 796         NF_CT_ASSERT(skb);
 797
 798         spin_lock_bh(&nf_conntrack_lock);
 799
 800         /* Only update if this is not a fixed timeout */
 801         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 802                 goto acct;
 803
 804         /* If not in hash table, timer will not be active yet */
 805         if (!nf_ct_is_confirmed(ct)) {
 806                 ct->timeout.expires = extra_jiffies;
 807                 event = IPCT_REFRESH;
 808         } else {
 809                 unsigned long newtime = jiffies + extra_jiffies;
 810
 811                 /* Only update the timeout if the new timeout is at least
 812                    HZ jiffies from the old timeout. Need del_timer for race
 813                    avoidance (may already be dying). */
 814                 if (newtime - ct->timeout.expires >= HZ
 815                     && del_timer(&ct->timeout)) {
 816                         ct->timeout.expires = newtime;
 817                         add_timer(&ct->timeout);
 818                         event = IPCT_REFRESH;
 819                 }
 820         }
 821
 822 acct:
 823         if (do_acct) {
 824                 struct nf_conn_counter *acct;
 825
 826                 acct = nf_conn_acct_find(ct);
 827                 if (acct) {
 828                         acct[CTINFO2DIR(ctinfo)].packets++;
 829                         acct[CTINFO2DIR(ctinfo)].bytes +=
 830                                 skb->len - skb_network_offset(skb);
 831                 }
 832         }
 833
 834         spin_unlock_bh(&nf_conntrack_lock);
 835
 836         /* must be unlocked when calling event cache */
 837         if (event)
 838                 nf_conntrack_event_cache(event, ct);
 839 }
 840 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 841
 842 bool __nf_ct_kill_acct(struct nf_conn *ct,
 843                        enum ip_conntrack_info ctinfo,
 844                        const struct sk_buff *skb,
 845                        int do_acct)
 846 {
 847         if (do_acct) {
 848                 struct nf_conn_counter *acct;
 849
 850                 spin_lock_bh(&nf_conntrack_lock);
 851                 acct = nf_conn_acct_find(ct);
 852                 if (acct) {
 853                         acct[CTINFO2DIR(ctinfo)].packets++;
 854                         acct[CTINFO2DIR(ctinfo)].bytes +=
 855                                 skb->len - skb_network_offset(skb);
 856                 }
 857                 spin_unlock_bh(&nf_conntrack_lock);
 858         }
 859
 860         if (del_timer(&ct->timeout)) {
 861                 ct->timeout.function((unsigned long)ct);
 862                 return true;
 863         }
 864         return false;
 865 }
 866 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 867
 868 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 869
 870 #include <linux/netfilter/nfnetlink.h>
 871 #include <linux/netfilter/nfnetlink_conntrack.h>
 872 #include <linux/mutex.h>
 873
 874 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 875  * in ip_conntrack_core, since we don't want the protocols to autoload
 876  * or depend on ctnetlink */
 877 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 878                                const struct nf_conntrack_tuple *tuple)
 879 {
 880         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 881         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 882         return 0;
 883
 884 nla_put_failure:
 885         return -1;
 886 }
 887 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 888
 889 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 890         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 891         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 892 };
 893 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 894
 895 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 896                                struct nf_conntrack_tuple *t)
 897 {
 898         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 899                 return -EINVAL;
 900
 901         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 902         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 903
 904         return 0;
 905 }
 906 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 907 #endif
 908
 909 /* Used by ipt_REJECT and ip6t_REJECT. */
 910 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 911 {
 912         struct nf_conn *ct;
 913         enum ip_conntrack_info ctinfo;
 914
 915         /* This ICMP is in reverse direction to the packet which caused it */
 916         ct = nf_ct_get(skb, &ctinfo);
 917         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 918                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 919         else
 920                 ctinfo = IP_CT_RELATED;
 921
 922         /* Attach to new skbuff, and increment count */
 923         nskb->nfct = &ct->ct_general;
 924         nskb->nfctinfo = ctinfo;
 925         nf_conntrack_get(nskb->nfct);
 926 }
 927
 928 /* Bring out ya dead! */
 929 static struct nf_conn *
 930 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 931                 void *data, unsigned int *bucket)
 932 {
 933         struct nf_conntrack_tuple_hash *h;
 934         struct nf_conn *ct;
 935         struct hlist_node *n;
 936
 937         spin_lock_bh(&nf_conntrack_lock);
 938         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 939                 hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) {
 940                         ct = nf_ct_tuplehash_to_ctrack(h);
 941                         if (iter(ct, data))
 942                                 goto found;
 943                 }
 944         }
 945         hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) {
 946                 ct = nf_ct_tuplehash_to_ctrack(h);
 947                 if (iter(ct, data))
 948                         set_bit(IPS_DYING_BIT, &ct->status);
 949         }
 950         spin_unlock_bh(&nf_conntrack_lock);
 951         return NULL;
 952 found:
 953         atomic_inc(&ct->ct_general.use);
 954         spin_unlock_bh(&nf_conntrack_lock);
 955         return ct;
 956 }
 957
 958 void nf_ct_iterate_cleanup(struct net *net,
 959                            int (*iter)(struct nf_conn *i, void *data),
 960                            void *data)
 961 {
 962         struct nf_conn *ct;
 963         unsigned int bucket = 0;
 964
 965         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 966                 /* Time to push up daises... */
 967                 if (del_timer(&ct->timeout))
 968                         death_by_timeout((unsigned long)ct);
 969                 /* ... else the timer will get him soon. */
 970
 971                 nf_ct_put(ct);
 972         }
 973 }
 974 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 975
 976 struct __nf_ct_flush_report {
 977         u32 pid;
 978         int report;
 979 };
 980
 981 static int kill_all(struct nf_conn *i, void *data)
 982 {
 983         struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
 984
 985         /* get_next_corpse sets the dying bit for us */
 986         nf_conntrack_event_report(IPCT_DESTROY,
 987                                   i,
 988                                   fr->pid,
 989                                   fr->report);
 990         return 1;
 991 }
 992
 993 void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size)
 994 {
 995         if (vmalloced)
 996                 vfree(hash);
 997         else
 998                 free_pages((unsigned long)hash,
 999                            get_order(sizeof(struct hlist_head) * size));
1000 }
1001 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1002
1003 void nf_conntrack_flush(struct net *net, u32 pid, int report)
1004 {
1005         struct __nf_ct_flush_report fr = {
1006                 .pid    = pid,
1007                 .report = report,
1008         };
1009         nf_ct_iterate_cleanup(net, kill_all, &fr);
1010 }
1011 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1012
1013 static void nf_conntrack_cleanup_init_net(void)
1014 {
1015         nf_conntrack_helper_fini();
1016         nf_conntrack_proto_fini();
1017         kmem_cache_destroy(nf_conntrack_cachep);
1018 }
1019
1020 static void nf_conntrack_cleanup_net(struct net *net)
1021 {
1022         nf_ct_event_cache_flush(net);
1023         nf_conntrack_ecache_fini(net);
1024  i_see_dead_people:
1025         nf_conntrack_flush(net, 0, 0);
1026         if (atomic_read(&net->ct.count) != 0) {
1027                 schedule();
1028                 goto i_see_dead_people;
1029         }
1030         /* wait until all references to nf_conntrack_untracked are dropped */
1031         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1032                 schedule();
1033
1034         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1035                              nf_conntrack_htable_size);
1036         nf_conntrack_acct_fini(net);
1037         nf_conntrack_expect_fini(net);
1038         free_percpu(net->ct.stat);
1039 }
1040
1041 /* Mishearing the voices in his head, our hero wonders how he's
1042    supposed to kill the mall. */
1043 void nf_conntrack_cleanup(struct net *net)
1044 {
1045         if (net_eq(net, &init_net))
1046                 rcu_assign_pointer(ip_ct_attach, NULL);
1047
1048         /* This makes sure all current packets have passed through
1049            netfilter framework.  Roll on, two-stage module
1050            delete... */
1051         synchronize_net();
1052
1053         nf_conntrack_cleanup_net(net);
1054
1055         if (net_eq(net, &init_net)) {
1056                 rcu_assign_pointer(nf_ct_destroy, NULL);
1057                 nf_conntrack_cleanup_init_net();
1058         }
1059 }
1060
1061 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
1062 {
1063         struct hlist_head *hash;
1064         unsigned int size, i;
1065
1066         *vmalloced = 0;
1067
1068         size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1069         hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1070                                        get_order(sizeof(struct hlist_head)
1071                                                  * size));
1072         if (!hash) {
1073                 *vmalloced = 1;
1074                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1075                 hash = vmalloc(sizeof(struct hlist_head) * size);
1076         }
1077
1078         if (hash)
1079                 for (i = 0; i < size; i++)
1080                         INIT_HLIST_HEAD(&hash[i]);
1081
1082         return hash;
1083 }
1084 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1085
1086 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1087 {
1088         int i, bucket, vmalloced, old_vmalloced;
1089         unsigned int hashsize, old_size;
1090         int rnd;
1091         struct hlist_head *hash, *old_hash;
1092         struct nf_conntrack_tuple_hash *h;
1093
1094         /* On boot, we can set this without any fancy locking. */
1095         if (!nf_conntrack_htable_size)
1096                 return param_set_uint(val, kp);
1097
1098         hashsize = simple_strtoul(val, NULL, 0);
1099         if (!hashsize)
1100                 return -EINVAL;
1101
1102         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1103         if (!hash)
1104                 return -ENOMEM;
1105
1106         /* We have to rehahs for the new table anyway, so we also can
1107          * use a newrandom seed */
1108         get_random_bytes(&rnd, 4);
1109
1110         /* Lookups in the old hash might happen in parallel, which means we
1111          * might get false negatives during connection lookup. New connections
1112          * created because of a false negative won't make it into the hash
1113          * though since that required taking the lock.
1114          */
1115         spin_lock_bh(&nf_conntrack_lock);
1116         for (i = 0; i < nf_conntrack_htable_size; i++) {
1117                 while (!hlist_empty(&init_net.ct.hash[i])) {
1118                         h = hlist_entry(init_net.ct.hash[i].first,
1119                                         struct nf_conntrack_tuple_hash, hnode);
1120                         hlist_del_rcu(&h->hnode);
1121                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1122                         hlist_add_head(&h->hnode, &hash[bucket]);
1123                 }
1124         }
1125         old_size = nf_conntrack_htable_size;
1126         old_vmalloced = init_net.ct.hash_vmalloc;
1127         old_hash = init_net.ct.hash;
1128
1129         nf_conntrack_htable_size = hashsize;
1130         init_net.ct.hash_vmalloc = vmalloced;
1131         init_net.ct.hash = hash;
1132         nf_conntrack_hash_rnd = rnd;
1133         spin_unlock_bh(&nf_conntrack_lock);
1134
1135         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1136         return 0;
1137 }
1138 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1139
1140 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1141                   &nf_conntrack_htable_size, 0600);
1142
1143 static int nf_conntrack_init_init_net(void)
1144 {
1145         int max_factor = 8;
1146         int ret;
1147
1148         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1149          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1150         if (!nf_conntrack_htable_size) {
1151                 nf_conntrack_htable_size
1152                         = (((num_physpages << PAGE_SHIFT) / 16384)
1153                            / sizeof(struct hlist_head));
1154                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1155                         nf_conntrack_htable_size = 16384;
1156                 if (nf_conntrack_htable_size < 32)
1157                         nf_conntrack_htable_size = 32;
1158
1159                 /* Use a max. factor of four by default to get the same max as
1160                  * with the old struct list_heads. When a table size is given
1161                  * we use the old value of 8 to avoid reducing the max.
1162                  * entries. */
1163                 max_factor = 4;
1164         }
1165         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1166
1167         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1168                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1169                nf_conntrack_max);
1170
1171         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1172                                                 sizeof(struct nf_conn),
1173                                                 0, 0, NULL);
1174         if (!nf_conntrack_cachep) {
1175                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1176                 ret = -ENOMEM;
1177                 goto err_cache;
1178         }
1179
1180         ret = nf_conntrack_proto_init();
1181         if (ret < 0)
1182                 goto err_proto;
1183
1184         ret = nf_conntrack_helper_init();
1185         if (ret < 0)
1186                 goto err_helper;
1187
1188         return 0;
1189
1190 err_helper:
1191         nf_conntrack_proto_fini();
1192 err_proto:
1193         kmem_cache_destroy(nf_conntrack_cachep);
1194 err_cache:
1195         return ret;
1196 }
1197
1198 static int nf_conntrack_init_net(struct net *net)
1199 {
1200         int ret;
1201
1202         atomic_set(&net->ct.count, 0);
1203         INIT_HLIST_HEAD(&net->ct.unconfirmed);
1204         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1205         if (!net->ct.stat) {
1206                 ret = -ENOMEM;
1207                 goto err_stat;
1208         }
1209         ret = nf_conntrack_ecache_init(net);
1210         if (ret < 0)
1211                 goto err_ecache;
1212         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1213                                                   &net->ct.hash_vmalloc);
1214         if (!net->ct.hash) {
1215                 ret = -ENOMEM;
1216                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1217                 goto err_hash;
1218         }
1219         ret = nf_conntrack_expect_init(net);
1220         if (ret < 0)
1221                 goto err_expect;
1222         ret = nf_conntrack_acct_init(net);
1223         if (ret < 0)
1224                 goto err_acct;
1225
1226         /* Set up fake conntrack:
1227             - to never be deleted, not in any hashes */
1228 #ifdef CONFIG_NET_NS
1229         nf_conntrack_untracked.ct_net = &init_net;
1230 #endif
1231         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1232         /*  - and look it like as a confirmed connection */
1233         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1234
1235         return 0;
1236
1237 err_acct:
1238         nf_conntrack_expect_fini(net);
1239 err_expect:
1240         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1241                              nf_conntrack_htable_size);
1242 err_hash:
1243         nf_conntrack_ecache_fini(net);
1244 err_ecache:
1245         free_percpu(net->ct.stat);
1246 err_stat:
1247         return ret;
1248 }
1249
1250 int nf_conntrack_init(struct net *net)
1251 {
1252         int ret;
1253
1254         if (net_eq(net, &init_net)) {
1255                 ret = nf_conntrack_init_init_net();
1256                 if (ret < 0)
1257                         goto out_init_net;
1258         }
1259         ret = nf_conntrack_init_net(net);
1260         if (ret < 0)
1261                 goto out_net;
1262
1263         if (net_eq(net, &init_net)) {
1264                 /* For use by REJECT target */
1265                 rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1266                 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1267         }
1268         return 0;
1269
1270 out_net:
1271         if (net_eq(net, &init_net))
1272                 nf_conntrack_cleanup_init_net();
1273 out_init_net:
1274         return ret;
1275 }