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 #include <linux/rculist_nulls.h>
  33
  34 #include <net/netfilter/nf_conntrack.h>
  35 #include <net/netfilter/nf_conntrack_l3proto.h>
  36 #include <net/netfilter/nf_conntrack_l4proto.h>
  37 #include <net/netfilter/nf_conntrack_expect.h>
  38 #include <net/netfilter/nf_conntrack_helper.h>
  39 #include <net/netfilter/nf_conntrack_core.h>
  40 #include <net/netfilter/nf_conntrack_extend.h>
  41 #include <net/netfilter/nf_conntrack_acct.h>
  42 #include <net/netfilter/nf_nat.h>
  43 #include <net/netfilter/nf_nat_core.h>
  44
  45 #define NF_CONNTRACK_VERSION    "0.5.0"
  46
  47 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
  48                                       enum nf_nat_manip_type manip,
  49                                       struct nlattr *attr) __read_mostly;
  50 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
  51
  52 DEFINE_SPINLOCK(nf_conntrack_lock);
  53 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  54
  55 unsigned int nf_conntrack_htable_size __read_mostly;
  56 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
  57
  58 unsigned int nf_conntrack_max __read_mostly;
  59 EXPORT_SYMBOL_GPL(nf_conntrack_max);
  60
  61 struct nf_conn nf_conntrack_untracked __read_mostly;
  62 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
  63
  64 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
  65
  66 static int nf_conntrack_hash_rnd_initted;
  67 static unsigned int nf_conntrack_hash_rnd;
  68
  69 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
  70                                   unsigned int size, unsigned int rnd)
  71 {
  72         unsigned int n;
  73         u_int32_t h;
  74
  75         /* The direction must be ignored, so we hash everything up to the
  76          * destination ports (which is a multiple of 4) and treat the last
  77          * three bytes manually.
  78          */
  79         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
  80         h = jhash2((u32 *)tuple, n,
  81                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
  82                           tuple->dst.protonum));
  83
  84         return ((u64)h * size) >> 32;
  85 }
  86
  87 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
  88 {
  89         return __hash_conntrack(tuple, nf_conntrack_htable_size,
  90                                 nf_conntrack_hash_rnd);
  91 }
  92
  93 bool
  94 nf_ct_get_tuple(const struct sk_buff *skb,
  95                 unsigned int nhoff,
  96                 unsigned int dataoff,
  97                 u_int16_t l3num,
  98                 u_int8_t protonum,
  99                 struct nf_conntrack_tuple *tuple,
 100                 const struct nf_conntrack_l3proto *l3proto,
 101                 const struct nf_conntrack_l4proto *l4proto)
 102 {
 103         memset(tuple, 0, sizeof(*tuple));
 104
 105         tuple->src.l3num = l3num;
 106         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 107                 return false;
 108
 109         tuple->dst.protonum = protonum;
 110         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 111
 112         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 113 }
 114 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 115
 116 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 117                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 118 {
 119         struct nf_conntrack_l3proto *l3proto;
 120         struct nf_conntrack_l4proto *l4proto;
 121         unsigned int protoff;
 122         u_int8_t protonum;
 123         int ret;
 124
 125         rcu_read_lock();
 126
 127         l3proto = __nf_ct_l3proto_find(l3num);
 128         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 129         if (ret != NF_ACCEPT) {
 130                 rcu_read_unlock();
 131                 return false;
 132         }
 133
 134         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 135
 136         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 137                               l3proto, l4proto);
 138
 139         rcu_read_unlock();
 140         return ret;
 141 }
 142 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 143
 144 bool
 145 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 146                    const struct nf_conntrack_tuple *orig,
 147                    const struct nf_conntrack_l3proto *l3proto,
 148                    const struct nf_conntrack_l4proto *l4proto)
 149 {
 150         memset(inverse, 0, sizeof(*inverse));
 151
 152         inverse->src.l3num = orig->src.l3num;
 153         if (l3proto->invert_tuple(inverse, orig) == 0)
 154                 return false;
 155
 156         inverse->dst.dir = !orig->dst.dir;
 157
 158         inverse->dst.protonum = orig->dst.protonum;
 159         return l4proto->invert_tuple(inverse, orig);
 160 }
 161 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 162
 163 static void
 164 clean_from_lists(struct nf_conn *ct)
 165 {
 166         pr_debug("clean_from_lists(%p)\n", ct);
 167         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 168         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 169
 170         /* Destroy all pending expectations */
 171         nf_ct_remove_expectations(ct);
 172 }
 173
 174 static void
 175 destroy_conntrack(struct nf_conntrack *nfct)
 176 {
 177         struct nf_conn *ct = (struct nf_conn *)nfct;
 178         struct net *net = nf_ct_net(ct);
 179         struct nf_conntrack_l4proto *l4proto;
 180
 181         pr_debug("destroy_conntrack(%p)\n", ct);
 182         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 183         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 184
 185         if (!test_bit(IPS_DYING_BIT, &ct->status))
 186                 nf_conntrack_event(IPCT_DESTROY, ct);
 187         set_bit(IPS_DYING_BIT, &ct->status);
 188
 189         /* To make sure we don't get any weird locking issues here:
 190          * destroy_conntrack() MUST NOT be called with a write lock
 191          * to nf_conntrack_lock!!! -HW */
 192         rcu_read_lock();
 193         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 194         if (l4proto && l4proto->destroy)
 195                 l4proto->destroy(ct);
 196
 197         rcu_read_unlock();
 198
 199         spin_lock_bh(&nf_conntrack_lock);
 200         /* Expectations will have been removed in clean_from_lists,
 201          * except TFTP can create an expectation on the first packet,
 202          * before connection is in the list, so we need to clean here,
 203          * too. */
 204         nf_ct_remove_expectations(ct);
 205
 206         /* We overload first tuple to link into unconfirmed list. */
 207         if (!nf_ct_is_confirmed(ct)) {
 208                 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 209                 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 210         }
 211
 212         NF_CT_STAT_INC(net, delete);
 213         spin_unlock_bh(&nf_conntrack_lock);
 214
 215         if (ct->master)
 216                 nf_ct_put(ct->master);
 217
 218         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 219         nf_conntrack_free(ct);
 220 }
 221
 222 static void death_by_timeout(unsigned long ul_conntrack)
 223 {
 224         struct nf_conn *ct = (void *)ul_conntrack;
 225         struct net *net = nf_ct_net(ct);
 226         struct nf_conn_help *help = nfct_help(ct);
 227         struct nf_conntrack_helper *helper;
 228
 229         if (help) {
 230                 rcu_read_lock();
 231                 helper = rcu_dereference(help->helper);
 232                 if (helper && helper->destroy)
 233                         helper->destroy(ct);
 234                 rcu_read_unlock();
 235         }
 236
 237         spin_lock_bh(&nf_conntrack_lock);
 238         /* Inside lock so preempt is disabled on module removal path.
 239          * Otherwise we can get spurious warnings. */
 240         NF_CT_STAT_INC(net, delete_list);
 241         clean_from_lists(ct);
 242         spin_unlock_bh(&nf_conntrack_lock);
 243         nf_ct_put(ct);
 244 }
 245
 246 /*
 247  * Warning :
 248  * - Caller must take a reference on returned object
 249  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 250  * OR
 251  * - Caller must lock nf_conntrack_lock before calling this function
 252  */
 253 struct nf_conntrack_tuple_hash *
 254 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 255 {
 256         struct nf_conntrack_tuple_hash *h;
 257         struct hlist_nulls_node *n;
 258         unsigned int hash = hash_conntrack(tuple);
 259
 260         /* Disable BHs the entire time since we normally need to disable them
 261          * at least once for the stats anyway.
 262          */
 263         local_bh_disable();
 264 begin:
 265         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 266                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
 267                         NF_CT_STAT_INC(net, found);
 268                         local_bh_enable();
 269                         return h;
 270                 }
 271                 NF_CT_STAT_INC(net, searched);
 272         }
 273         /*
 274          * if the nulls value we got at the end of this lookup is
 275          * not the expected one, we must restart lookup.
 276          * We probably met an item that was moved to another chain.
 277          */
 278         if (get_nulls_value(n) != hash)
 279                 goto begin;
 280         local_bh_enable();
 281
 282         return NULL;
 283 }
 284 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
 285
 286 /* Find a connection corresponding to a tuple. */
 287 struct nf_conntrack_tuple_hash *
 288 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 289 {
 290         struct nf_conntrack_tuple_hash *h;
 291         struct nf_conn *ct;
 292
 293         rcu_read_lock();
 294 begin:
 295         h = __nf_conntrack_find(net, tuple);
 296         if (h) {
 297                 ct = nf_ct_tuplehash_to_ctrack(h);
 298                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 299                         h = NULL;
 300                 else {
 301                         if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple))) {
 302                                 nf_ct_put(ct);
 303                                 goto begin;
 304                         }
 305                 }
 306         }
 307         rcu_read_unlock();
 308
 309         return h;
 310 }
 311 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 312
 313 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 314                                        unsigned int hash,
 315                                        unsigned int repl_hash)
 316 {
 317         struct net *net = nf_ct_net(ct);
 318
 319         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 320                            &net->ct.hash[hash]);
 321         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 322                            &net->ct.hash[repl_hash]);
 323 }
 324
 325 void nf_conntrack_hash_insert(struct nf_conn *ct)
 326 {
 327         unsigned int hash, repl_hash;
 328
 329         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 330         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 331
 332         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 333 }
 334 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
 335
 336 /* Confirm a connection given skb; places it in hash table */
 337 int
 338 __nf_conntrack_confirm(struct sk_buff *skb)
 339 {
 340         unsigned int hash, repl_hash;
 341         struct nf_conntrack_tuple_hash *h;
 342         struct nf_conn *ct;
 343         struct nf_conn_help *help;
 344         struct hlist_nulls_node *n;
 345         enum ip_conntrack_info ctinfo;
 346         struct net *net;
 347
 348         ct = nf_ct_get(skb, &ctinfo);
 349         net = nf_ct_net(ct);
 350
 351         /* ipt_REJECT uses nf_conntrack_attach to attach related
 352            ICMP/TCP RST packets in other direction.  Actual packet
 353            which created connection will be IP_CT_NEW or for an
 354            expected connection, IP_CT_RELATED. */
 355         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 356                 return NF_ACCEPT;
 357
 358         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 359         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 360
 361         /* We're not in hash table, and we refuse to set up related
 362            connections for unconfirmed conns.  But packet copies and
 363            REJECT will give spurious warnings here. */
 364         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 365
 366         /* No external references means noone else could have
 367            confirmed us. */
 368         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 369         pr_debug("Confirming conntrack %p\n", ct);
 370
 371         spin_lock_bh(&nf_conntrack_lock);
 372
 373         /* See if there's one in the list already, including reverse:
 374            NAT could have grabbed it without realizing, since we're
 375            not in the hash.  If there is, we lost race. */
 376         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 377                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 378                                       &h->tuple))
 379                         goto out;
 380         hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
 381                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 382                                       &h->tuple))
 383                         goto out;
 384
 385         /* Remove from unconfirmed list */
 386         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 387
 388         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 389         /* Timer relative to confirmation time, not original
 390            setting time, otherwise we'd get timer wrap in
 391            weird delay cases. */
 392         ct->timeout.expires += jiffies;
 393         add_timer(&ct->timeout);
 394         atomic_inc(&ct->ct_general.use);
 395         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 396         NF_CT_STAT_INC(net, insert);
 397         spin_unlock_bh(&nf_conntrack_lock);
 398         help = nfct_help(ct);
 399         if (help && help->helper)
 400                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 401 #ifdef CONFIG_NF_NAT_NEEDED
 402         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 403             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 404                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
 405 #endif
 406         nf_conntrack_event_cache(master_ct(ct) ?
 407                                  IPCT_RELATED : IPCT_NEW, ct);
 408         return NF_ACCEPT;
 409
 410 out:
 411         NF_CT_STAT_INC(net, insert_failed);
 412         spin_unlock_bh(&nf_conntrack_lock);
 413         return NF_DROP;
 414 }
 415 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 416
 417 /* Returns true if a connection correspondings to the tuple (required
 418    for NAT). */
 419 int
 420 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 421                          const struct nf_conn *ignored_conntrack)
 422 {
 423         struct net *net = nf_ct_net(ignored_conntrack);
 424         struct nf_conntrack_tuple_hash *h;
 425         struct hlist_nulls_node *n;
 426         unsigned int hash = hash_conntrack(tuple);
 427
 428         /* Disable BHs the entire time since we need to disable them at
 429          * least once for the stats anyway.
 430          */
 431         rcu_read_lock_bh();
 432         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 433                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 434                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 435                         NF_CT_STAT_INC(net, found);
 436                         rcu_read_unlock_bh();
 437                         return 1;
 438                 }
 439                 NF_CT_STAT_INC(net, searched);
 440         }
 441         rcu_read_unlock_bh();
 442
 443         return 0;
 444 }
 445 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 446
 447 #define NF_CT_EVICTION_RANGE    8
 448
 449 /* There's a small race here where we may free a just-assured
 450    connection.  Too bad: we're in trouble anyway. */
 451 static noinline int early_drop(struct net *net, unsigned int hash)
 452 {
 453         /* Use oldest entry, which is roughly LRU */
 454         struct nf_conntrack_tuple_hash *h;
 455         struct nf_conn *ct = NULL, *tmp;
 456         struct hlist_nulls_node *n;
 457         unsigned int i, cnt = 0;
 458         int dropped = 0;
 459
 460         rcu_read_lock();
 461         for (i = 0; i < nf_conntrack_htable_size; i++) {
 462                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 463                                          hnnode) {
 464                         tmp = nf_ct_tuplehash_to_ctrack(h);
 465                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
 466                                 ct = tmp;
 467                         cnt++;
 468                 }
 469
 470                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
 471                         ct = NULL;
 472                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 473                         break;
 474                 hash = (hash + 1) % nf_conntrack_htable_size;
 475         }
 476         rcu_read_unlock();
 477
 478         if (!ct)
 479                 return dropped;
 480
 481         if (del_timer(&ct->timeout)) {
 482                 death_by_timeout((unsigned long)ct);
 483                 dropped = 1;
 484                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
 485         }
 486         nf_ct_put(ct);
 487         return dropped;
 488 }
 489
 490 struct nf_conn *nf_conntrack_alloc(struct net *net,
 491                                    const struct nf_conntrack_tuple *orig,
 492                                    const struct nf_conntrack_tuple *repl,
 493                                    gfp_t gfp)
 494 {
 495         struct nf_conn *ct;
 496
 497         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 498                 get_random_bytes(&nf_conntrack_hash_rnd,
 499                                 sizeof(nf_conntrack_hash_rnd));
 500                 nf_conntrack_hash_rnd_initted = 1;
 501         }
 502
 503         /* We don't want any race condition at early drop stage */
 504         atomic_inc(&net->ct.count);
 505
 506         if (nf_conntrack_max &&
 507             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 508                 unsigned int hash = hash_conntrack(orig);
 509                 if (!early_drop(net, hash)) {
 510                         atomic_dec(&net->ct.count);
 511                         if (net_ratelimit())
 512                                 printk(KERN_WARNING
 513                                        "nf_conntrack: table full, dropping"
 514                                        " packet.\n");
 515                         return ERR_PTR(-ENOMEM);
 516                 }
 517         }
 518
 519         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
 520         if (ct == NULL) {
 521                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
 522                 atomic_dec(&net->ct.count);
 523                 return ERR_PTR(-ENOMEM);
 524         }
 525
 526         atomic_set(&ct->ct_general.use, 1);
 527         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 528         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 529         /* Don't set timer yet: wait for confirmation */
 530         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 531 #ifdef CONFIG_NET_NS
 532         ct->ct_net = net;
 533 #endif
 534
 535         return ct;
 536 }
 537 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 538
 539 void nf_conntrack_free(struct nf_conn *ct)
 540 {
 541         struct net *net = nf_ct_net(ct);
 542
 543         nf_ct_ext_destroy(ct);
 544         atomic_dec(&net->ct.count);
 545         nf_ct_ext_free(ct);
 546         kmem_cache_free(nf_conntrack_cachep, ct);
 547 }
 548 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 549
 550 /* Allocate a new conntrack: we return -ENOMEM if classification
 551    failed due to stress.  Otherwise it really is unclassifiable. */
 552 static struct nf_conntrack_tuple_hash *
 553 init_conntrack(struct net *net,
 554                const struct nf_conntrack_tuple *tuple,
 555                struct nf_conntrack_l3proto *l3proto,
 556                struct nf_conntrack_l4proto *l4proto,
 557                struct sk_buff *skb,
 558                unsigned int dataoff)
 559 {
 560         struct nf_conn *ct;
 561         struct nf_conn_help *help;
 562         struct nf_conntrack_tuple repl_tuple;
 563         struct nf_conntrack_expect *exp;
 564
 565         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 566                 pr_debug("Can't invert tuple.\n");
 567                 return NULL;
 568         }
 569
 570         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
 571         if (IS_ERR(ct)) {
 572                 pr_debug("Can't allocate conntrack.\n");
 573                 return (struct nf_conntrack_tuple_hash *)ct;
 574         }
 575
 576         if (!l4proto->new(ct, skb, dataoff)) {
 577                 nf_conntrack_free(ct);
 578                 pr_debug("init conntrack: can't track with proto module\n");
 579                 return NULL;
 580         }
 581
 582         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 583
 584         spin_lock_bh(&nf_conntrack_lock);
 585         exp = nf_ct_find_expectation(net, tuple);
 586         if (exp) {
 587                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 588                          ct, exp);
 589                 /* Welcome, Mr. Bond.  We've been expecting you... */
 590                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
 591                 ct->master = exp->master;
 592                 if (exp->helper) {
 593                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
 594                         if (help)
 595                                 rcu_assign_pointer(help->helper, exp->helper);
 596                 }
 597
 598 #ifdef CONFIG_NF_CONNTRACK_MARK
 599                 ct->mark = exp->master->mark;
 600 #endif
 601 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 602                 ct->secmark = exp->master->secmark;
 603 #endif
 604                 nf_conntrack_get(&ct->master->ct_general);
 605                 NF_CT_STAT_INC(net, expect_new);
 606         } else {
 607                 __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 608                 NF_CT_STAT_INC(net, new);
 609         }
 610
 611         /* Overload tuple linked list to put us in unconfirmed list. */
 612         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 613                        &net->ct.unconfirmed);
 614
 615         spin_unlock_bh(&nf_conntrack_lock);
 616
 617         if (exp) {
 618                 if (exp->expectfn)
 619                         exp->expectfn(ct, exp);
 620                 nf_ct_expect_put(exp);
 621         }
 622
 623         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
 624 }
 625
 626 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 627 static inline struct nf_conn *
 628 resolve_normal_ct(struct net *net,
 629                   struct sk_buff *skb,
 630                   unsigned int dataoff,
 631                   u_int16_t l3num,
 632                   u_int8_t protonum,
 633                   struct nf_conntrack_l3proto *l3proto,
 634                   struct nf_conntrack_l4proto *l4proto,
 635                   int *set_reply,
 636                   enum ip_conntrack_info *ctinfo)
 637 {
 638         struct nf_conntrack_tuple tuple;
 639         struct nf_conntrack_tuple_hash *h;
 640         struct nf_conn *ct;
 641
 642         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 643                              dataoff, l3num, protonum, &tuple, l3proto,
 644                              l4proto)) {
 645                 pr_debug("resolve_normal_ct: Can't get tuple\n");
 646                 return NULL;
 647         }
 648
 649         /* look for tuple match */
 650         h = nf_conntrack_find_get(net, &tuple);
 651         if (!h) {
 652                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
 653                 if (!h)
 654                         return NULL;
 655                 if (IS_ERR(h))
 656                         return (void *)h;
 657         }
 658         ct = nf_ct_tuplehash_to_ctrack(h);
 659
 660         /* It exists; we have (non-exclusive) reference. */
 661         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 662                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 663                 /* Please set reply bit if this packet OK */
 664                 *set_reply = 1;
 665         } else {
 666                 /* Once we've had two way comms, always ESTABLISHED. */
 667                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 668                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
 669                         *ctinfo = IP_CT_ESTABLISHED;
 670                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 671                         pr_debug("nf_conntrack_in: related packet for %p\n",
 672                                  ct);
 673                         *ctinfo = IP_CT_RELATED;
 674                 } else {
 675                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
 676                         *ctinfo = IP_CT_NEW;
 677                 }
 678                 *set_reply = 0;
 679         }
 680         skb->nfct = &ct->ct_general;
 681         skb->nfctinfo = *ctinfo;
 682         return ct;
 683 }
 684
 685 unsigned int
 686 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
 687                 struct sk_buff *skb)
 688 {
 689         struct nf_conn *ct;
 690         enum ip_conntrack_info ctinfo;
 691         struct nf_conntrack_l3proto *l3proto;
 692         struct nf_conntrack_l4proto *l4proto;
 693         unsigned int dataoff;
 694         u_int8_t protonum;
 695         int set_reply = 0;
 696         int ret;
 697
 698         /* Previously seen (loopback or untracked)?  Ignore. */
 699         if (skb->nfct) {
 700                 NF_CT_STAT_INC_ATOMIC(net, ignore);
 701                 return NF_ACCEPT;
 702         }
 703
 704         /* rcu_read_lock()ed by nf_hook_slow */
 705         l3proto = __nf_ct_l3proto_find(pf);
 706         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
 707                                    &dataoff, &protonum);
 708         if (ret <= 0) {
 709                 pr_debug("not prepared to track yet or error occured\n");
 710                 NF_CT_STAT_INC_ATOMIC(net, error);
 711                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 712                 return -ret;
 713         }
 714
 715         l4proto = __nf_ct_l4proto_find(pf, protonum);
 716
 717         /* It may be an special packet, error, unclean...
 718          * inverse of the return code tells to the netfilter
 719          * core what to do with the packet. */
 720         if (l4proto->error != NULL) {
 721                 ret = l4proto->error(net, skb, dataoff, &ctinfo, pf, hooknum);
 722                 if (ret <= 0) {
 723                         NF_CT_STAT_INC_ATOMIC(net, error);
 724                         NF_CT_STAT_INC_ATOMIC(net, invalid);
 725                         return -ret;
 726                 }
 727         }
 728
 729         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
 730                                l3proto, l4proto, &set_reply, &ctinfo);
 731         if (!ct) {
 732                 /* Not valid part of a connection */
 733                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 734                 return NF_ACCEPT;
 735         }
 736
 737         if (IS_ERR(ct)) {
 738                 /* Too stressed to deal. */
 739                 NF_CT_STAT_INC_ATOMIC(net, drop);
 740                 return NF_DROP;
 741         }
 742
 743         NF_CT_ASSERT(skb->nfct);
 744
 745         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
 746         if (ret <= 0) {
 747                 /* Invalid: inverse of the return code tells
 748                  * the netfilter core what to do */
 749                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
 750                 nf_conntrack_put(skb->nfct);
 751                 skb->nfct = NULL;
 752                 NF_CT_STAT_INC_ATOMIC(net, invalid);
 753                 if (ret == -NF_DROP)
 754                         NF_CT_STAT_INC_ATOMIC(net, drop);
 755                 return -ret;
 756         }
 757
 758         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 759                 nf_conntrack_event_cache(IPCT_STATUS, ct);
 760
 761         return ret;
 762 }
 763 EXPORT_SYMBOL_GPL(nf_conntrack_in);
 764
 765 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 766                           const struct nf_conntrack_tuple *orig)
 767 {
 768         bool ret;
 769
 770         rcu_read_lock();
 771         ret = nf_ct_invert_tuple(inverse, orig,
 772                                  __nf_ct_l3proto_find(orig->src.l3num),
 773                                  __nf_ct_l4proto_find(orig->src.l3num,
 774                                                       orig->dst.protonum));
 775         rcu_read_unlock();
 776         return ret;
 777 }
 778 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
 779
 780 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
 781    implicitly racy: see __nf_conntrack_confirm */
 782 void nf_conntrack_alter_reply(struct nf_conn *ct,
 783                               const struct nf_conntrack_tuple *newreply)
 784 {
 785         struct nf_conn_help *help = nfct_help(ct);
 786
 787         /* Should be unconfirmed, so not in hash table yet */
 788         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 789
 790         pr_debug("Altering reply tuple of %p to ", ct);
 791         nf_ct_dump_tuple(newreply);
 792
 793         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
 794         if (ct->master || (help && !hlist_empty(&help->expectations)))
 795                 return;
 796
 797         rcu_read_lock();
 798         __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
 799         rcu_read_unlock();
 800 }
 801 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
 802
 803 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 804 void __nf_ct_refresh_acct(struct nf_conn *ct,
 805                           enum ip_conntrack_info ctinfo,
 806                           const struct sk_buff *skb,
 807                           unsigned long extra_jiffies,
 808                           int do_acct)
 809 {
 810         int event = 0;
 811
 812         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 813         NF_CT_ASSERT(skb);
 814
 815         spin_lock_bh(&nf_conntrack_lock);
 816
 817         /* Only update if this is not a fixed timeout */
 818         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
 819                 goto acct;
 820
 821         /* If not in hash table, timer will not be active yet */
 822         if (!nf_ct_is_confirmed(ct)) {
 823                 ct->timeout.expires = extra_jiffies;
 824                 event = IPCT_REFRESH;
 825         } else {
 826                 unsigned long newtime = jiffies + extra_jiffies;
 827
 828                 /* Only update the timeout if the new timeout is at least
 829                    HZ jiffies from the old timeout. Need del_timer for race
 830                    avoidance (may already be dying). */
 831                 if (newtime - ct->timeout.expires >= HZ
 832                     && del_timer(&ct->timeout)) {
 833                         ct->timeout.expires = newtime;
 834                         add_timer(&ct->timeout);
 835                         event = IPCT_REFRESH;
 836                 }
 837         }
 838
 839 acct:
 840         if (do_acct) {
 841                 struct nf_conn_counter *acct;
 842
 843                 acct = nf_conn_acct_find(ct);
 844                 if (acct) {
 845                         acct[CTINFO2DIR(ctinfo)].packets++;
 846                         acct[CTINFO2DIR(ctinfo)].bytes +=
 847                                 skb->len - skb_network_offset(skb);
 848                 }
 849         }
 850
 851         spin_unlock_bh(&nf_conntrack_lock);
 852
 853         /* must be unlocked when calling event cache */
 854         if (event)
 855                 nf_conntrack_event_cache(event, ct);
 856 }
 857 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 858
 859 bool __nf_ct_kill_acct(struct nf_conn *ct,
 860                        enum ip_conntrack_info ctinfo,
 861                        const struct sk_buff *skb,
 862                        int do_acct)
 863 {
 864         if (do_acct) {
 865                 struct nf_conn_counter *acct;
 866
 867                 spin_lock_bh(&nf_conntrack_lock);
 868                 acct = nf_conn_acct_find(ct);
 869                 if (acct) {
 870                         acct[CTINFO2DIR(ctinfo)].packets++;
 871                         acct[CTINFO2DIR(ctinfo)].bytes +=
 872                                 skb->len - skb_network_offset(skb);
 873                 }
 874                 spin_unlock_bh(&nf_conntrack_lock);
 875         }
 876
 877         if (del_timer(&ct->timeout)) {
 878                 ct->timeout.function((unsigned long)ct);
 879                 return true;
 880         }
 881         return false;
 882 }
 883 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 884
 885 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 886
 887 #include <linux/netfilter/nfnetlink.h>
 888 #include <linux/netfilter/nfnetlink_conntrack.h>
 889 #include <linux/mutex.h>
 890
 891 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 892  * in ip_conntrack_core, since we don't want the protocols to autoload
 893  * or depend on ctnetlink */
 894 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 895                                const struct nf_conntrack_tuple *tuple)
 896 {
 897         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
 898         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
 899         return 0;
 900
 901 nla_put_failure:
 902         return -1;
 903 }
 904 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
 905
 906 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
 907         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
 908         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
 909 };
 910 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
 911
 912 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 913                                struct nf_conntrack_tuple *t)
 914 {
 915         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
 916                 return -EINVAL;
 917
 918         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
 919         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
 920
 921         return 0;
 922 }
 923 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
 924
 925 int nf_ct_port_nlattr_tuple_size(void)
 926 {
 927         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
 928 }
 929 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
 930 #endif
 931
 932 /* Used by ipt_REJECT and ip6t_REJECT. */
 933 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 934 {
 935         struct nf_conn *ct;
 936         enum ip_conntrack_info ctinfo;
 937
 938         /* This ICMP is in reverse direction to the packet which caused it */
 939         ct = nf_ct_get(skb, &ctinfo);
 940         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 941                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 942         else
 943                 ctinfo = IP_CT_RELATED;
 944
 945         /* Attach to new skbuff, and increment count */
 946         nskb->nfct = &ct->ct_general;
 947         nskb->nfctinfo = ctinfo;
 948         nf_conntrack_get(nskb->nfct);
 949 }
 950
 951 /* Bring out ya dead! */
 952 static struct nf_conn *
 953 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
 954                 void *data, unsigned int *bucket)
 955 {
 956         struct nf_conntrack_tuple_hash *h;
 957         struct nf_conn *ct;
 958         struct hlist_nulls_node *n;
 959
 960         spin_lock_bh(&nf_conntrack_lock);
 961         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 962                 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
 963                         ct = nf_ct_tuplehash_to_ctrack(h);
 964                         if (iter(ct, data))
 965                                 goto found;
 966                 }
 967         }
 968         hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
 969                 ct = nf_ct_tuplehash_to_ctrack(h);
 970                 if (iter(ct, data))
 971                         set_bit(IPS_DYING_BIT, &ct->status);
 972         }
 973         spin_unlock_bh(&nf_conntrack_lock);
 974         return NULL;
 975 found:
 976         atomic_inc(&ct->ct_general.use);
 977         spin_unlock_bh(&nf_conntrack_lock);
 978         return ct;
 979 }
 980
 981 void nf_ct_iterate_cleanup(struct net *net,
 982                            int (*iter)(struct nf_conn *i, void *data),
 983                            void *data)
 984 {
 985         struct nf_conn *ct;
 986         unsigned int bucket = 0;
 987
 988         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
 989                 /* Time to push up daises... */
 990                 if (del_timer(&ct->timeout))
 991                         death_by_timeout((unsigned long)ct);
 992                 /* ... else the timer will get him soon. */
 993
 994                 nf_ct_put(ct);
 995         }
 996 }
 997 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
 998
 999 struct __nf_ct_flush_report {
1000         u32 pid;
1001         int report;
1002 };
1003
1004 static int kill_all(struct nf_conn *i, void *data)
1005 {
1006         struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1007
1008         /* get_next_corpse sets the dying bit for us */
1009         nf_conntrack_event_report(IPCT_DESTROY,
1010                                   i,
1011                                   fr->pid,
1012                                   fr->report);
1013         return 1;
1014 }
1015
1016 void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size)
1017 {
1018         if (vmalloced)
1019                 vfree(hash);
1020         else
1021                 free_pages((unsigned long)hash,
1022                            get_order(sizeof(struct hlist_head) * size));
1023 }
1024 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1025
1026 void nf_conntrack_flush(struct net *net, u32 pid, int report)
1027 {
1028         struct __nf_ct_flush_report fr = {
1029                 .pid    = pid,
1030                 .report = report,
1031         };
1032         nf_ct_iterate_cleanup(net, kill_all, &fr);
1033 }
1034 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1035
1036 static void nf_conntrack_cleanup_init_net(void)
1037 {
1038         nf_conntrack_helper_fini();
1039         nf_conntrack_proto_fini();
1040         kmem_cache_destroy(nf_conntrack_cachep);
1041 }
1042
1043 static void nf_conntrack_cleanup_net(struct net *net)
1044 {
1045         nf_ct_event_cache_flush(net);
1046         nf_conntrack_ecache_fini(net);
1047  i_see_dead_people:
1048         nf_conntrack_flush(net, 0, 0);
1049         if (atomic_read(&net->ct.count) != 0) {
1050                 schedule();
1051                 goto i_see_dead_people;
1052         }
1053         /* wait until all references to nf_conntrack_untracked are dropped */
1054         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1055                 schedule();
1056
1057         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1058                              nf_conntrack_htable_size);
1059         nf_conntrack_acct_fini(net);
1060         nf_conntrack_expect_fini(net);
1061         free_percpu(net->ct.stat);
1062 }
1063
1064 /* Mishearing the voices in his head, our hero wonders how he's
1065    supposed to kill the mall. */
1066 void nf_conntrack_cleanup(struct net *net)
1067 {
1068         if (net_eq(net, &init_net))
1069                 rcu_assign_pointer(ip_ct_attach, NULL);
1070
1071         /* This makes sure all current packets have passed through
1072            netfilter framework.  Roll on, two-stage module
1073            delete... */
1074         synchronize_net();
1075
1076         nf_conntrack_cleanup_net(net);
1077
1078         if (net_eq(net, &init_net)) {
1079                 rcu_assign_pointer(nf_ct_destroy, NULL);
1080                 nf_conntrack_cleanup_init_net();
1081         }
1082 }
1083
1084 void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls)
1085 {
1086         struct hlist_nulls_head *hash;
1087         unsigned int nr_slots, i;
1088         size_t sz;
1089
1090         *vmalloced = 0;
1091
1092         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1093         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1094         sz = nr_slots * sizeof(struct hlist_nulls_head);
1095         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1096                                         get_order(sz));
1097         if (!hash) {
1098                 *vmalloced = 1;
1099                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1100                 hash = __vmalloc(sz, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
1101         }
1102
1103         if (hash && nulls)
1104                 for (i = 0; i < nr_slots; i++)
1105                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1106
1107         return hash;
1108 }
1109 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1110
1111 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1112 {
1113         int i, bucket, vmalloced, old_vmalloced;
1114         unsigned int hashsize, old_size;
1115         int rnd;
1116         struct hlist_nulls_head *hash, *old_hash;
1117         struct nf_conntrack_tuple_hash *h;
1118
1119         /* On boot, we can set this without any fancy locking. */
1120         if (!nf_conntrack_htable_size)
1121                 return param_set_uint(val, kp);
1122
1123         hashsize = simple_strtoul(val, NULL, 0);
1124         if (!hashsize)
1125                 return -EINVAL;
1126
1127         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced, 1);
1128         if (!hash)
1129                 return -ENOMEM;
1130
1131         /* We have to rehahs for the new table anyway, so we also can
1132          * use a newrandom seed */
1133         get_random_bytes(&rnd, sizeof(rnd));
1134
1135         /* Lookups in the old hash might happen in parallel, which means we
1136          * might get false negatives during connection lookup. New connections
1137          * created because of a false negative won't make it into the hash
1138          * though since that required taking the lock.
1139          */
1140         spin_lock_bh(&nf_conntrack_lock);
1141         for (i = 0; i < nf_conntrack_htable_size; i++) {
1142                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1143                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1144                                         struct nf_conntrack_tuple_hash, hnnode);
1145                         hlist_nulls_del_rcu(&h->hnnode);
1146                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1147                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1148                 }
1149         }
1150         old_size = nf_conntrack_htable_size;
1151         old_vmalloced = init_net.ct.hash_vmalloc;
1152         old_hash = init_net.ct.hash;
1153
1154         nf_conntrack_htable_size = hashsize;
1155         init_net.ct.hash_vmalloc = vmalloced;
1156         init_net.ct.hash = hash;
1157         nf_conntrack_hash_rnd = rnd;
1158         spin_unlock_bh(&nf_conntrack_lock);
1159
1160         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1161         return 0;
1162 }
1163 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1164
1165 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1166                   &nf_conntrack_htable_size, 0600);
1167
1168 static int nf_conntrack_init_init_net(void)
1169 {
1170         int max_factor = 8;
1171         int ret;
1172
1173         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1174          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1175         if (!nf_conntrack_htable_size) {
1176                 nf_conntrack_htable_size
1177                         = (((num_physpages << PAGE_SHIFT) / 16384)
1178                            / sizeof(struct hlist_head));
1179                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1180                         nf_conntrack_htable_size = 16384;
1181                 if (nf_conntrack_htable_size < 32)
1182                         nf_conntrack_htable_size = 32;
1183
1184                 /* Use a max. factor of four by default to get the same max as
1185                  * with the old struct list_heads. When a table size is given
1186                  * we use the old value of 8 to avoid reducing the max.
1187                  * entries. */
1188                 max_factor = 4;
1189         }
1190         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1191
1192         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1193                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1194                nf_conntrack_max);
1195
1196         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1197                                                 sizeof(struct nf_conn),
1198                                                 0, SLAB_DESTROY_BY_RCU, NULL);
1199         if (!nf_conntrack_cachep) {
1200                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1201                 ret = -ENOMEM;
1202                 goto err_cache;
1203         }
1204
1205         ret = nf_conntrack_proto_init();
1206         if (ret < 0)
1207                 goto err_proto;
1208
1209         ret = nf_conntrack_helper_init();
1210         if (ret < 0)
1211                 goto err_helper;
1212
1213         return 0;
1214
1215 err_helper:
1216         nf_conntrack_proto_fini();
1217 err_proto:
1218         kmem_cache_destroy(nf_conntrack_cachep);
1219 err_cache:
1220         return ret;
1221 }
1222
1223 static int nf_conntrack_init_net(struct net *net)
1224 {
1225         int ret;
1226
1227         atomic_set(&net->ct.count, 0);
1228         INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, 0);
1229         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1230         if (!net->ct.stat) {
1231                 ret = -ENOMEM;
1232                 goto err_stat;
1233         }
1234         ret = nf_conntrack_ecache_init(net);
1235         if (ret < 0)
1236                 goto err_ecache;
1237         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1238                                              &net->ct.hash_vmalloc, 1);
1239         if (!net->ct.hash) {
1240                 ret = -ENOMEM;
1241                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1242                 goto err_hash;
1243         }
1244         ret = nf_conntrack_expect_init(net);
1245         if (ret < 0)
1246                 goto err_expect;
1247         ret = nf_conntrack_acct_init(net);
1248         if (ret < 0)
1249                 goto err_acct;
1250
1251         /* Set up fake conntrack:
1252             - to never be deleted, not in any hashes */
1253 #ifdef CONFIG_NET_NS
1254         nf_conntrack_untracked.ct_net = &init_net;
1255 #endif
1256         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1257         /*  - and look it like as a confirmed connection */
1258         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1259
1260         return 0;
1261
1262 err_acct:
1263         nf_conntrack_expect_fini(net);
1264 err_expect:
1265         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1266                              nf_conntrack_htable_size);
1267 err_hash:
1268         nf_conntrack_ecache_fini(net);
1269 err_ecache:
1270         free_percpu(net->ct.stat);
1271 err_stat:
1272         return ret;
1273 }
1274
1275 int nf_conntrack_init(struct net *net)
1276 {
1277         int ret;
1278
1279         if (net_eq(net, &init_net)) {
1280                 ret = nf_conntrack_init_init_net();
1281                 if (ret < 0)
1282                         goto out_init_net;
1283         }
1284         ret = nf_conntrack_init_net(net);
1285         if (ret < 0)
1286                 goto out_net;
1287
1288         if (net_eq(net, &init_net)) {
1289                 /* For use by REJECT target */
1290                 rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1291                 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1292         }
1293         return 0;
1294
1295 out_net:
1296         if (net_eq(net, &init_net))
1297                 nf_conntrack_cleanup_init_net();
1298 out_init_net:
1299         return ret;
1300 }