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