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  * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17 #include <linux/types.h>
  18 #include <linux/netfilter.h>
  19 #include <linux/module.h>
  20 #include <linux/sched.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/stddef.h>
  25 #include <linux/slab.h>
  26 #include <linux/random.h>
  27 #include <linux/jhash.h>
  28 #include <linux/err.h>
  29 #include <linux/percpu.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/notifier.h>
  32 #include <linux/kernel.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/socket.h>
  35 #include <linux/mm.h>
  36 #include <linux/nsproxy.h>
  37 #include <linux/rculist_nulls.h>
  38
  39 #include <net/netfilter/nf_conntrack.h>
  40 #include <net/netfilter/nf_conntrack_l3proto.h>
  41 #include <net/netfilter/nf_conntrack_l4proto.h>
  42 #include <net/netfilter/nf_conntrack_expect.h>
  43 #include <net/netfilter/nf_conntrack_helper.h>
  44 #include <net/netfilter/nf_conntrack_seqadj.h>
  45 #include <net/netfilter/nf_conntrack_core.h>
  46 #include <net/netfilter/nf_conntrack_extend.h>
  47 #include <net/netfilter/nf_conntrack_acct.h>
  48 #include <net/netfilter/nf_conntrack_ecache.h>
  49 #include <net/netfilter/nf_conntrack_zones.h>
  50 #include <net/netfilter/nf_conntrack_timestamp.h>
  51 #include <net/netfilter/nf_conntrack_timeout.h>
  52 #include <net/netfilter/nf_conntrack_labels.h>
  53 #include <net/netfilter/nf_conntrack_synproxy.h>
  54 #include <net/netfilter/nf_nat.h>
  55 #include <net/netfilter/nf_nat_core.h>
  56 #include <net/netfilter/nf_nat_helper.h>
  57 #include <net/netns/hash.h>
  58
  59 #define NF_CONNTRACK_VERSION    "0.5.0"
  60
  61 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
  62                                       enum nf_nat_manip_type manip,
  63                                       const struct nlattr *attr) __read_mostly;
  64 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
  65
  66 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
  67 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
  68
  69 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
  70 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
  71
  72 struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
  73 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
  74
  75 static __read_mostly struct kmem_cache *nf_conntrack_cachep;
  76 static __read_mostly spinlock_t nf_conntrack_locks_all_lock;
  77 static __read_mostly DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
  78 static __read_mostly bool nf_conntrack_locks_all;
  79
  80 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
  81 {
  82         spin_lock(lock);
  83         while (unlikely(nf_conntrack_locks_all)) {
  84                 spin_unlock(lock);
  85
  86                 /*
  87                  * Order the 'nf_conntrack_locks_all' load vs. the
  88                  * spin_unlock_wait() loads below, to ensure
  89                  * that 'nf_conntrack_locks_all_lock' is indeed held:
  90                  */
  91                 smp_rmb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
  92                 spin_unlock_wait(&nf_conntrack_locks_all_lock);
  93                 spin_lock(lock);
  94         }
  95 }
  96 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  97
  98 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
  99 {
 100         h1 %= CONNTRACK_LOCKS;
 101         h2 %= CONNTRACK_LOCKS;
 102         spin_unlock(&nf_conntrack_locks[h1]);
 103         if (h1 != h2)
 104                 spin_unlock(&nf_conntrack_locks[h2]);
 105 }
 106
 107 /* return true if we need to recompute hashes (in case hash table was resized) */
 108 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
 109                                      unsigned int h2, unsigned int sequence)
 110 {
 111         h1 %= CONNTRACK_LOCKS;
 112         h2 %= CONNTRACK_LOCKS;
 113         if (h1 <= h2) {
 114                 nf_conntrack_lock(&nf_conntrack_locks[h1]);
 115                 if (h1 != h2)
 116                         spin_lock_nested(&nf_conntrack_locks[h2],
 117                                          SINGLE_DEPTH_NESTING);
 118         } else {
 119                 nf_conntrack_lock(&nf_conntrack_locks[h2]);
 120                 spin_lock_nested(&nf_conntrack_locks[h1],
 121                                  SINGLE_DEPTH_NESTING);
 122         }
 123         if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
 124                 nf_conntrack_double_unlock(h1, h2);
 125                 return true;
 126         }
 127         return false;
 128 }
 129
 130 static void nf_conntrack_all_lock(void)
 131 {
 132         int i;
 133
 134         spin_lock(&nf_conntrack_locks_all_lock);
 135         nf_conntrack_locks_all = true;
 136
 137         /*
 138          * Order the above store of 'nf_conntrack_locks_all' against
 139          * the spin_unlock_wait() loads below, such that if
 140          * nf_conntrack_lock() observes 'nf_conntrack_locks_all'
 141          * we must observe nf_conntrack_locks[] held:
 142          */
 143         smp_mb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
 144
 145         for (i = 0; i < CONNTRACK_LOCKS; i++) {
 146                 spin_unlock_wait(&nf_conntrack_locks[i]);
 147         }
 148 }
 149
 150 static void nf_conntrack_all_unlock(void)
 151 {
 152         /*
 153          * All prior stores must be complete before we clear
 154          * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
 155          * might observe the false value but not the entire
 156          * critical section:
 157          */
 158         smp_store_release(&nf_conntrack_locks_all, false);
 159         spin_unlock(&nf_conntrack_locks_all_lock);
 160 }
 161
 162 unsigned int nf_conntrack_htable_size __read_mostly;
 163 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
 164
 165 unsigned int nf_conntrack_max __read_mostly;
 166 seqcount_t nf_conntrack_generation __read_mostly;
 167
 168 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 169 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
 170
 171 static unsigned int nf_conntrack_hash_rnd __read_mostly;
 172
 173 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
 174                               const struct net *net)
 175 {
 176         unsigned int n;
 177         u32 seed;
 178
 179         get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
 180
 181         /* The direction must be ignored, so we hash everything up to the
 182          * destination ports (which is a multiple of 4) and treat the last
 183          * three bytes manually.
 184          */
 185         seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
 186         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
 187         return jhash2((u32 *)tuple, n, seed ^
 188                       (((__force __u16)tuple->dst.u.all << 16) |
 189                       tuple->dst.protonum));
 190 }
 191
 192 static u32 scale_hash(u32 hash)
 193 {
 194         return reciprocal_scale(hash, nf_conntrack_htable_size);
 195 }
 196
 197 static u32 __hash_conntrack(const struct net *net,
 198                             const struct nf_conntrack_tuple *tuple,
 199                             unsigned int size)
 200 {
 201         return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
 202 }
 203
 204 static u32 hash_conntrack(const struct net *net,
 205                           const struct nf_conntrack_tuple *tuple)
 206 {
 207         return scale_hash(hash_conntrack_raw(tuple, net));
 208 }
 209
 210 bool
 211 nf_ct_get_tuple(const struct sk_buff *skb,
 212                 unsigned int nhoff,
 213                 unsigned int dataoff,
 214                 u_int16_t l3num,
 215                 u_int8_t protonum,
 216                 struct net *net,
 217                 struct nf_conntrack_tuple *tuple,
 218                 const struct nf_conntrack_l3proto *l3proto,
 219                 const struct nf_conntrack_l4proto *l4proto)
 220 {
 221         memset(tuple, 0, sizeof(*tuple));
 222
 223         tuple->src.l3num = l3num;
 224         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 225                 return false;
 226
 227         tuple->dst.protonum = protonum;
 228         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 229
 230         return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
 231 }
 232 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 233
 234 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 235                        u_int16_t l3num,
 236                        struct net *net, struct nf_conntrack_tuple *tuple)
 237 {
 238         struct nf_conntrack_l3proto *l3proto;
 239         struct nf_conntrack_l4proto *l4proto;
 240         unsigned int protoff;
 241         u_int8_t protonum;
 242         int ret;
 243
 244         rcu_read_lock();
 245
 246         l3proto = __nf_ct_l3proto_find(l3num);
 247         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 248         if (ret != NF_ACCEPT) {
 249                 rcu_read_unlock();
 250                 return false;
 251         }
 252
 253         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 254
 255         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
 256                               l3proto, l4proto);
 257
 258         rcu_read_unlock();
 259         return ret;
 260 }
 261 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 262
 263 bool
 264 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 265                    const struct nf_conntrack_tuple *orig,
 266                    const struct nf_conntrack_l3proto *l3proto,
 267                    const struct nf_conntrack_l4proto *l4proto)
 268 {
 269         memset(inverse, 0, sizeof(*inverse));
 270
 271         inverse->src.l3num = orig->src.l3num;
 272         if (l3proto->invert_tuple(inverse, orig) == 0)
 273                 return false;
 274
 275         inverse->dst.dir = !orig->dst.dir;
 276
 277         inverse->dst.protonum = orig->dst.protonum;
 278         return l4proto->invert_tuple(inverse, orig);
 279 }
 280 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 281
 282 static void
 283 clean_from_lists(struct nf_conn *ct)
 284 {
 285         pr_debug("clean_from_lists(%p)\n", ct);
 286         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 287         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 288
 289         /* Destroy all pending expectations */
 290         nf_ct_remove_expectations(ct);
 291 }
 292
 293 /* must be called with local_bh_disable */
 294 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
 295 {
 296         struct ct_pcpu *pcpu;
 297
 298         /* add this conntrack to the (per cpu) dying list */
 299         ct->cpu = smp_processor_id();
 300         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 301
 302         spin_lock(&pcpu->lock);
 303         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 304                              &pcpu->dying);
 305         spin_unlock(&pcpu->lock);
 306 }
 307
 308 /* must be called with local_bh_disable */
 309 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
 310 {
 311         struct ct_pcpu *pcpu;
 312
 313         /* add this conntrack to the (per cpu) unconfirmed list */
 314         ct->cpu = smp_processor_id();
 315         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 316
 317         spin_lock(&pcpu->lock);
 318         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 319                              &pcpu->unconfirmed);
 320         spin_unlock(&pcpu->lock);
 321 }
 322
 323 /* must be called with local_bh_disable */
 324 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
 325 {
 326         struct ct_pcpu *pcpu;
 327
 328         /* We overload first tuple to link into unconfirmed or dying list.*/
 329         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 330
 331         spin_lock(&pcpu->lock);
 332         BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 333         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 334         spin_unlock(&pcpu->lock);
 335 }
 336
 337 /* Released via destroy_conntrack() */
 338 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
 339                                  const struct nf_conntrack_zone *zone,
 340                                  gfp_t flags)
 341 {
 342         struct nf_conn *tmpl;
 343
 344         tmpl = kzalloc(sizeof(*tmpl), flags);
 345         if (tmpl == NULL)
 346                 return NULL;
 347
 348         tmpl->status = IPS_TEMPLATE;
 349         write_pnet(&tmpl->ct_net, net);
 350         nf_ct_zone_add(tmpl, zone);
 351         atomic_set(&tmpl->ct_general.use, 0);
 352
 353         return tmpl;
 354 }
 355 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
 356
 357 void nf_ct_tmpl_free(struct nf_conn *tmpl)
 358 {
 359         nf_ct_ext_destroy(tmpl);
 360         nf_ct_ext_free(tmpl);
 361         kfree(tmpl);
 362 }
 363 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
 364
 365 static void
 366 destroy_conntrack(struct nf_conntrack *nfct)
 367 {
 368         struct nf_conn *ct = (struct nf_conn *)nfct;
 369         struct net *net = nf_ct_net(ct);
 370         struct nf_conntrack_l4proto *l4proto;
 371
 372         pr_debug("destroy_conntrack(%p)\n", ct);
 373         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 374
 375         if (unlikely(nf_ct_is_template(ct))) {
 376                 nf_ct_tmpl_free(ct);
 377                 return;
 378         }
 379         rcu_read_lock();
 380         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 381         if (l4proto->destroy)
 382                 l4proto->destroy(ct);
 383
 384         rcu_read_unlock();
 385
 386         local_bh_disable();
 387         /* Expectations will have been removed in clean_from_lists,
 388          * except TFTP can create an expectation on the first packet,
 389          * before connection is in the list, so we need to clean here,
 390          * too.
 391          */
 392         nf_ct_remove_expectations(ct);
 393
 394         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 395
 396         NF_CT_STAT_INC(net, delete);
 397         local_bh_enable();
 398
 399         if (ct->master)
 400                 nf_ct_put(ct->master);
 401
 402         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 403         nf_conntrack_free(ct);
 404 }
 405
 406 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 407 {
 408         struct net *net = nf_ct_net(ct);
 409         unsigned int hash, reply_hash;
 410         unsigned int sequence;
 411
 412         nf_ct_helper_destroy(ct);
 413
 414         local_bh_disable();
 415         do {
 416                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 417                 hash = hash_conntrack(net,
 418                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 419                 reply_hash = hash_conntrack(net,
 420                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 421         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 422
 423         clean_from_lists(ct);
 424         nf_conntrack_double_unlock(hash, reply_hash);
 425
 426         nf_ct_add_to_dying_list(ct);
 427
 428         NF_CT_STAT_INC(net, delete_list);
 429         local_bh_enable();
 430 }
 431
 432 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 433 {
 434         struct nf_conn_tstamp *tstamp;
 435
 436         if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
 437                 return false;
 438
 439         tstamp = nf_conn_tstamp_find(ct);
 440         if (tstamp && tstamp->stop == 0)
 441                 tstamp->stop = ktime_get_real_ns();
 442
 443         if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 444                                     portid, report) < 0) {
 445                 /* destroy event was not delivered. nf_ct_put will
 446                  * be done by event cache worker on redelivery.
 447                  */
 448                 nf_ct_delete_from_lists(ct);
 449                 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
 450                 return false;
 451         }
 452
 453         nf_conntrack_ecache_work(nf_ct_net(ct));
 454         nf_ct_delete_from_lists(ct);
 455         nf_ct_put(ct);
 456         return true;
 457 }
 458 EXPORT_SYMBOL_GPL(nf_ct_delete);
 459
 460 static inline bool
 461 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 462                 const struct nf_conntrack_tuple *tuple,
 463                 const struct nf_conntrack_zone *zone,
 464                 const struct net *net)
 465 {
 466         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 467
 468         /* A conntrack can be recreated with the equal tuple,
 469          * so we need to check that the conntrack is confirmed
 470          */
 471         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 472                nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
 473                nf_ct_is_confirmed(ct) &&
 474                net_eq(net, nf_ct_net(ct));
 475 }
 476
 477 /* caller must hold rcu readlock and none of the nf_conntrack_locks */
 478 static void nf_ct_gc_expired(struct nf_conn *ct)
 479 {
 480         if (!atomic_inc_not_zero(&ct->ct_general.use))
 481                 return;
 482
 483         if (nf_ct_should_gc(ct))
 484                 nf_ct_kill(ct);
 485
 486         nf_ct_put(ct);
 487 }
 488
 489 /*
 490  * Warning :
 491  * - Caller must take a reference on returned object
 492  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 493  */
 494 static struct nf_conntrack_tuple_hash *
 495 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
 496                       const struct nf_conntrack_tuple *tuple, u32 hash)
 497 {
 498         struct nf_conntrack_tuple_hash *h;
 499         struct hlist_nulls_head *ct_hash;
 500         struct hlist_nulls_node *n;
 501         unsigned int bucket, hsize;
 502
 503 begin:
 504         nf_conntrack_get_ht(&ct_hash, &hsize);
 505         bucket = reciprocal_scale(hash, hsize);
 506
 507         hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
 508                 struct nf_conn *ct;
 509
 510                 ct = nf_ct_tuplehash_to_ctrack(h);
 511                 if (nf_ct_is_expired(ct)) {
 512                         nf_ct_gc_expired(ct);
 513                         continue;
 514                 }
 515
 516                 if (nf_ct_is_dying(ct))
 517                         continue;
 518
 519                 if (nf_ct_key_equal(h, tuple, zone, net)) {
 520                         NF_CT_STAT_INC_ATOMIC(net, found);
 521                         return h;
 522                 }
 523                 NF_CT_STAT_INC_ATOMIC(net, searched);
 524         }
 525         /*
 526          * if the nulls value we got at the end of this lookup is
 527          * not the expected one, we must restart lookup.
 528          * We probably met an item that was moved to another chain.
 529          */
 530         if (get_nulls_value(n) != bucket) {
 531                 NF_CT_STAT_INC_ATOMIC(net, search_restart);
 532                 goto begin;
 533         }
 534
 535         return NULL;
 536 }
 537
 538 /* Find a connection corresponding to a tuple. */
 539 static struct nf_conntrack_tuple_hash *
 540 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 541                         const struct nf_conntrack_tuple *tuple, u32 hash)
 542 {
 543         struct nf_conntrack_tuple_hash *h;
 544         struct nf_conn *ct;
 545
 546         rcu_read_lock();
 547 begin:
 548         h = ____nf_conntrack_find(net, zone, tuple, hash);
 549         if (h) {
 550                 ct = nf_ct_tuplehash_to_ctrack(h);
 551                 if (unlikely(nf_ct_is_dying(ct) ||
 552                              !atomic_inc_not_zero(&ct->ct_general.use)))
 553                         h = NULL;
 554                 else {
 555                         if (unlikely(!nf_ct_key_equal(h, tuple, zone, net))) {
 556                                 nf_ct_put(ct);
 557                                 goto begin;
 558                         }
 559                 }
 560         }
 561         rcu_read_unlock();
 562
 563         return h;
 564 }
 565
 566 struct nf_conntrack_tuple_hash *
 567 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 568                       const struct nf_conntrack_tuple *tuple)
 569 {
 570         return __nf_conntrack_find_get(net, zone, tuple,
 571                                        hash_conntrack_raw(tuple, net));
 572 }
 573 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 574
 575 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 576                                        unsigned int hash,
 577                                        unsigned int reply_hash)
 578 {
 579         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 580                            &nf_conntrack_hash[hash]);
 581         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 582                            &nf_conntrack_hash[reply_hash]);
 583 }
 584
 585 int
 586 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 587 {
 588         const struct nf_conntrack_zone *zone;
 589         struct net *net = nf_ct_net(ct);
 590         unsigned int hash, reply_hash;
 591         struct nf_conntrack_tuple_hash *h;
 592         struct hlist_nulls_node *n;
 593         unsigned int sequence;
 594
 595         zone = nf_ct_zone(ct);
 596
 597         local_bh_disable();
 598         do {
 599                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 600                 hash = hash_conntrack(net,
 601                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 602                 reply_hash = hash_conntrack(net,
 603                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 604         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 605
 606         /* See if there's one in the list already, including reverse */
 607         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
 608                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 609                                     zone, net))
 610                         goto out;
 611
 612         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
 613                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 614                                     zone, net))
 615                         goto out;
 616
 617         smp_wmb();
 618         /* The caller holds a reference to this object */
 619         atomic_set(&ct->ct_general.use, 2);
 620         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 621         nf_conntrack_double_unlock(hash, reply_hash);
 622         NF_CT_STAT_INC(net, insert);
 623         local_bh_enable();
 624         return 0;
 625
 626 out:
 627         nf_conntrack_double_unlock(hash, reply_hash);
 628         NF_CT_STAT_INC(net, insert_failed);
 629         local_bh_enable();
 630         return -EEXIST;
 631 }
 632 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 633
 634 static inline void nf_ct_acct_update(struct nf_conn *ct,
 635                                      enum ip_conntrack_info ctinfo,
 636                                      unsigned int len)
 637 {
 638         struct nf_conn_acct *acct;
 639
 640         acct = nf_conn_acct_find(ct);
 641         if (acct) {
 642                 struct nf_conn_counter *counter = acct->counter;
 643
 644                 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
 645                 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
 646         }
 647 }
 648
 649 static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 650                              const struct nf_conn *loser_ct)
 651 {
 652         struct nf_conn_acct *acct;
 653
 654         acct = nf_conn_acct_find(loser_ct);
 655         if (acct) {
 656                 struct nf_conn_counter *counter = acct->counter;
 657                 unsigned int bytes;
 658
 659                 /* u32 should be fine since we must have seen one packet. */
 660                 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
 661                 nf_ct_acct_update(ct, ctinfo, bytes);
 662         }
 663 }
 664
 665 /* Resolve race on insertion if this protocol allows this. */
 666 static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
 667                                enum ip_conntrack_info ctinfo,
 668                                struct nf_conntrack_tuple_hash *h)
 669 {
 670         /* This is the conntrack entry already in hashes that won race. */
 671         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 672         struct nf_conntrack_l4proto *l4proto;
 673
 674         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 675         if (l4proto->allow_clash &&
 676             !nfct_nat(ct) &&
 677             !nf_ct_is_dying(ct) &&
 678             atomic_inc_not_zero(&ct->ct_general.use)) {
 679                 nf_ct_acct_merge(ct, ctinfo, (struct nf_conn *)skb->nfct);
 680                 nf_conntrack_put(skb->nfct);
 681                 /* Assign conntrack already in hashes to this skbuff. Don't
 682                  * modify skb->nfctinfo to ensure consistent stateful filtering.
 683                  */
 684                 skb->nfct = &ct->ct_general;
 685                 return NF_ACCEPT;
 686         }
 687         NF_CT_STAT_INC(net, drop);
 688         return NF_DROP;
 689 }
 690
 691 /* Confirm a connection given skb; places it in hash table */
 692 int
 693 __nf_conntrack_confirm(struct sk_buff *skb)
 694 {
 695         const struct nf_conntrack_zone *zone;
 696         unsigned int hash, reply_hash;
 697         struct nf_conntrack_tuple_hash *h;
 698         struct nf_conn *ct;
 699         struct nf_conn_help *help;
 700         struct nf_conn_tstamp *tstamp;
 701         struct hlist_nulls_node *n;
 702         enum ip_conntrack_info ctinfo;
 703         struct net *net;
 704         unsigned int sequence;
 705         int ret = NF_DROP;
 706
 707         ct = nf_ct_get(skb, &ctinfo);
 708         net = nf_ct_net(ct);
 709
 710         /* ipt_REJECT uses nf_conntrack_attach to attach related
 711            ICMP/TCP RST packets in other direction.  Actual packet
 712            which created connection will be IP_CT_NEW or for an
 713            expected connection, IP_CT_RELATED. */
 714         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 715                 return NF_ACCEPT;
 716
 717         zone = nf_ct_zone(ct);
 718         local_bh_disable();
 719
 720         do {
 721                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 722                 /* reuse the hash saved before */
 723                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 724                 hash = scale_hash(hash);
 725                 reply_hash = hash_conntrack(net,
 726                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 727
 728         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 729
 730         /* We're not in hash table, and we refuse to set up related
 731          * connections for unconfirmed conns.  But packet copies and
 732          * REJECT will give spurious warnings here.
 733          */
 734         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 735
 736         /* No external references means no one else could have
 737          * confirmed us.
 738          */
 739         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 740         pr_debug("Confirming conntrack %p\n", ct);
 741         /* We have to check the DYING flag after unlink to prevent
 742          * a race against nf_ct_get_next_corpse() possibly called from
 743          * user context, else we insert an already 'dead' hash, blocking
 744          * further use of that particular connection -JM.
 745          */
 746         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 747
 748         if (unlikely(nf_ct_is_dying(ct))) {
 749                 nf_ct_add_to_dying_list(ct);
 750                 goto dying;
 751         }
 752
 753         /* See if there's one in the list already, including reverse:
 754            NAT could have grabbed it without realizing, since we're
 755            not in the hash.  If there is, we lost race. */
 756         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
 757                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 758                                     zone, net))
 759                         goto out;
 760
 761         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
 762                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 763                                     zone, net))
 764                         goto out;
 765
 766         /* Timer relative to confirmation time, not original
 767            setting time, otherwise we'd get timer wrap in
 768            weird delay cases. */
 769         ct->timeout += nfct_time_stamp;
 770         atomic_inc(&ct->ct_general.use);
 771         ct->status |= IPS_CONFIRMED;
 772
 773         /* set conntrack timestamp, if enabled. */
 774         tstamp = nf_conn_tstamp_find(ct);
 775         if (tstamp) {
 776                 if (skb->tstamp.tv64 == 0)
 777                         __net_timestamp(skb);
 778
 779                 tstamp->start = ktime_to_ns(skb->tstamp);
 780         }
 781         /* Since the lookup is lockless, hash insertion must be done after
 782          * starting the timer and setting the CONFIRMED bit. The RCU barriers
 783          * guarantee that no other CPU can find the conntrack before the above
 784          * stores are visible.
 785          */
 786         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 787         nf_conntrack_double_unlock(hash, reply_hash);
 788         NF_CT_STAT_INC(net, insert);
 789         local_bh_enable();
 790
 791         help = nfct_help(ct);
 792         if (help && help->helper)
 793                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 794
 795         nf_conntrack_event_cache(master_ct(ct) ?
 796                                  IPCT_RELATED : IPCT_NEW, ct);
 797         return NF_ACCEPT;
 798
 799 out:
 800         nf_ct_add_to_dying_list(ct);
 801         ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
 802 dying:
 803         nf_conntrack_double_unlock(hash, reply_hash);
 804         NF_CT_STAT_INC(net, insert_failed);
 805         local_bh_enable();
 806         return ret;
 807 }
 808 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 809
 810 /* Returns true if a connection correspondings to the tuple (required
 811    for NAT). */
 812 int
 813 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 814                          const struct nf_conn *ignored_conntrack)
 815 {
 816         struct net *net = nf_ct_net(ignored_conntrack);
 817         const struct nf_conntrack_zone *zone;
 818         struct nf_conntrack_tuple_hash *h;
 819         struct hlist_nulls_head *ct_hash;
 820         unsigned int hash, hsize;
 821         struct hlist_nulls_node *n;
 822         struct nf_conn *ct;
 823
 824         zone = nf_ct_zone(ignored_conntrack);
 825
 826         rcu_read_lock();
 827  begin:
 828         nf_conntrack_get_ht(&ct_hash, &hsize);
 829         hash = __hash_conntrack(net, tuple, hsize);
 830
 831         hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
 832                 ct = nf_ct_tuplehash_to_ctrack(h);
 833
 834                 if (ct == ignored_conntrack)
 835                         continue;
 836
 837                 if (nf_ct_is_expired(ct)) {
 838                         nf_ct_gc_expired(ct);
 839                         continue;
 840                 }
 841
 842                 if (nf_ct_key_equal(h, tuple, zone, net)) {
 843                         NF_CT_STAT_INC_ATOMIC(net, found);
 844                         rcu_read_unlock();
 845                         return 1;
 846                 }
 847                 NF_CT_STAT_INC_ATOMIC(net, searched);
 848         }
 849
 850         if (get_nulls_value(n) != hash) {
 851                 NF_CT_STAT_INC_ATOMIC(net, search_restart);
 852                 goto begin;
 853         }
 854
 855         rcu_read_unlock();
 856
 857         return 0;
 858 }
 859 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 860
 861 #define NF_CT_EVICTION_RANGE    8
 862
 863 /* There's a small race here where we may free a just-assured
 864    connection.  Too bad: we're in trouble anyway. */
 865 static unsigned int early_drop_list(struct net *net,
 866                                     struct hlist_nulls_head *head)
 867 {
 868         struct nf_conntrack_tuple_hash *h;
 869         struct hlist_nulls_node *n;
 870         unsigned int drops = 0;
 871         struct nf_conn *tmp;
 872
 873         hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
 874                 tmp = nf_ct_tuplehash_to_ctrack(h);
 875
 876                 if (nf_ct_is_expired(tmp)) {
 877                         nf_ct_gc_expired(tmp);
 878                         continue;
 879                 }
 880
 881                 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
 882                     !net_eq(nf_ct_net(tmp), net) ||
 883                     nf_ct_is_dying(tmp))
 884                         continue;
 885
 886                 if (!atomic_inc_not_zero(&tmp->ct_general.use))
 887                         continue;
 888
 889                 /* kill only if still in same netns -- might have moved due to
 890                  * SLAB_DESTROY_BY_RCU rules.
 891                  *
 892                  * We steal the timer reference.  If that fails timer has
 893                  * already fired or someone else deleted it. Just drop ref
 894                  * and move to next entry.
 895                  */
 896                 if (net_eq(nf_ct_net(tmp), net) &&
 897                     nf_ct_is_confirmed(tmp) &&
 898                     nf_ct_delete(tmp, 0, 0))
 899                         drops++;
 900
 901                 nf_ct_put(tmp);
 902         }
 903
 904         return drops;
 905 }
 906
 907 static noinline int early_drop(struct net *net, unsigned int _hash)
 908 {
 909         unsigned int i;
 910
 911         for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
 912                 struct hlist_nulls_head *ct_hash;
 913                 unsigned int hash, hsize, drops;
 914
 915                 rcu_read_lock();
 916                 nf_conntrack_get_ht(&ct_hash, &hsize);
 917                 hash = reciprocal_scale(_hash++, hsize);
 918
 919                 drops = early_drop_list(net, &ct_hash[hash]);
 920                 rcu_read_unlock();
 921
 922                 if (drops) {
 923                         NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
 924                         return true;
 925                 }
 926         }
 927
 928         return false;
 929 }
 930
 931 static struct nf_conn *
 932 __nf_conntrack_alloc(struct net *net,
 933                      const struct nf_conntrack_zone *zone,
 934                      const struct nf_conntrack_tuple *orig,
 935                      const struct nf_conntrack_tuple *repl,
 936                      gfp_t gfp, u32 hash)
 937 {
 938         struct nf_conn *ct;
 939
 940         /* We don't want any race condition at early drop stage */
 941         atomic_inc(&net->ct.count);
 942
 943         if (nf_conntrack_max &&
 944             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 945                 if (!early_drop(net, hash)) {
 946                         atomic_dec(&net->ct.count);
 947                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
 948                         return ERR_PTR(-ENOMEM);
 949                 }
 950         }
 951
 952         /*
 953          * Do not use kmem_cache_zalloc(), as this cache uses
 954          * SLAB_DESTROY_BY_RCU.
 955          */
 956         ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
 957         if (ct == NULL)
 958                 goto out;
 959
 960         spin_lock_init(&ct->lock);
 961         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 962         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
 963         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 964         /* save hash for reusing when confirming */
 965         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 966         ct->status = 0;
 967         write_pnet(&ct->ct_net, net);
 968         memset(&ct->__nfct_init_offset[0], 0,
 969                offsetof(struct nf_conn, proto) -
 970                offsetof(struct nf_conn, __nfct_init_offset[0]));
 971
 972         nf_ct_zone_add(ct, zone);
 973
 974         /* Because we use RCU lookups, we set ct_general.use to zero before
 975          * this is inserted in any list.
 976          */
 977         atomic_set(&ct->ct_general.use, 0);
 978         return ct;
 979 out:
 980         atomic_dec(&net->ct.count);
 981         return ERR_PTR(-ENOMEM);
 982 }
 983
 984 struct nf_conn *nf_conntrack_alloc(struct net *net,
 985                                    const struct nf_conntrack_zone *zone,
 986                                    const struct nf_conntrack_tuple *orig,
 987                                    const struct nf_conntrack_tuple *repl,
 988                                    gfp_t gfp)
 989 {
 990         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
 991 }
 992 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 993
 994 void nf_conntrack_free(struct nf_conn *ct)
 995 {
 996         struct net *net = nf_ct_net(ct);
 997
 998         /* A freed object has refcnt == 0, that's
 999          * the golden rule for SLAB_DESTROY_BY_RCU
1000          */
1001         NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
1002
1003         nf_ct_ext_destroy(ct);
1004         nf_ct_ext_free(ct);
1005         kmem_cache_free(nf_conntrack_cachep, ct);
1006         smp_mb__before_atomic();
1007         atomic_dec(&net->ct.count);
1008 }
1009 EXPORT_SYMBOL_GPL(nf_conntrack_free);
1010
1011
1012 /* Allocate a new conntrack: we return -ENOMEM if classification
1013    failed due to stress.  Otherwise it really is unclassifiable. */
1014 static struct nf_conntrack_tuple_hash *
1015 init_conntrack(struct net *net, struct nf_conn *tmpl,
1016                const struct nf_conntrack_tuple *tuple,
1017                struct nf_conntrack_l3proto *l3proto,
1018                struct nf_conntrack_l4proto *l4proto,
1019                struct sk_buff *skb,
1020                unsigned int dataoff, u32 hash)
1021 {
1022         struct nf_conn *ct;
1023         struct nf_conn_help *help;
1024         struct nf_conntrack_tuple repl_tuple;
1025         struct nf_conntrack_ecache *ecache;
1026         struct nf_conntrack_expect *exp = NULL;
1027         const struct nf_conntrack_zone *zone;
1028         struct nf_conn_timeout *timeout_ext;
1029         struct nf_conntrack_zone tmp;
1030         unsigned int *timeouts;
1031
1032         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
1033                 pr_debug("Can't invert tuple.\n");
1034                 return NULL;
1035         }
1036
1037         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1038         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1039                                   hash);
1040         if (IS_ERR(ct))
1041                 return (struct nf_conntrack_tuple_hash *)ct;
1042
1043         if (tmpl && nfct_synproxy(tmpl)) {
1044                 nfct_seqadj_ext_add(ct);
1045                 nfct_synproxy_ext_add(ct);
1046         }
1047
1048         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1049         if (timeout_ext) {
1050                 timeouts = nf_ct_timeout_data(timeout_ext);
1051                 if (unlikely(!timeouts))
1052                         timeouts = l4proto->get_timeouts(net);
1053         } else {
1054                 timeouts = l4proto->get_timeouts(net);
1055         }
1056
1057         if (!l4proto->new(ct, skb, dataoff, timeouts)) {
1058                 nf_conntrack_free(ct);
1059                 pr_debug("can't track with proto module\n");
1060                 return NULL;
1061         }
1062
1063         if (timeout_ext)
1064                 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1065                                       GFP_ATOMIC);
1066
1067         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1068         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1069         nf_ct_labels_ext_add(ct);
1070
1071         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1072         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1073                                  ecache ? ecache->expmask : 0,
1074                              GFP_ATOMIC);
1075
1076         local_bh_disable();
1077         if (net->ct.expect_count) {
1078                 spin_lock(&nf_conntrack_expect_lock);
1079                 exp = nf_ct_find_expectation(net, zone, tuple);
1080                 if (exp) {
1081                         pr_debug("expectation arrives ct=%p exp=%p\n",
1082                                  ct, exp);
1083                         /* Welcome, Mr. Bond.  We've been expecting you... */
1084                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
1085                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1086                         ct->master = exp->master;
1087                         if (exp->helper) {
1088                                 help = nf_ct_helper_ext_add(ct, exp->helper,
1089                                                             GFP_ATOMIC);
1090                                 if (help)
1091                                         rcu_assign_pointer(help->helper, exp->helper);
1092                         }
1093
1094 #ifdef CONFIG_NF_CONNTRACK_MARK
1095                         ct->mark = exp->master->mark;
1096 #endif
1097 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1098                         ct->secmark = exp->master->secmark;
1099 #endif
1100                         NF_CT_STAT_INC(net, expect_new);
1101                 }
1102                 spin_unlock(&nf_conntrack_expect_lock);
1103         }
1104         if (!exp) {
1105                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1106                 NF_CT_STAT_INC(net, new);
1107         }
1108
1109         /* Now it is inserted into the unconfirmed list, bump refcount */
1110         nf_conntrack_get(&ct->ct_general);
1111         nf_ct_add_to_unconfirmed_list(ct);
1112
1113         local_bh_enable();
1114
1115         if (exp) {
1116                 if (exp->expectfn)
1117                         exp->expectfn(ct, exp);
1118                 nf_ct_expect_put(exp);
1119         }
1120
1121         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1122 }
1123
1124 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1125 static inline struct nf_conn *
1126 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1127                   struct sk_buff *skb,
1128                   unsigned int dataoff,
1129                   u_int16_t l3num,
1130                   u_int8_t protonum,
1131                   struct nf_conntrack_l3proto *l3proto,
1132                   struct nf_conntrack_l4proto *l4proto,
1133                   int *set_reply,
1134                   enum ip_conntrack_info *ctinfo)
1135 {
1136         const struct nf_conntrack_zone *zone;
1137         struct nf_conntrack_tuple tuple;
1138         struct nf_conntrack_tuple_hash *h;
1139         struct nf_conntrack_zone tmp;
1140         struct nf_conn *ct;
1141         u32 hash;
1142
1143         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1144                              dataoff, l3num, protonum, net, &tuple, l3proto,
1145                              l4proto)) {
1146                 pr_debug("Can't get tuple\n");
1147                 return NULL;
1148         }
1149
1150         /* look for tuple match */
1151         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1152         hash = hash_conntrack_raw(&tuple, net);
1153         h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1154         if (!h) {
1155                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1156                                    skb, dataoff, hash);
1157                 if (!h)
1158                         return NULL;
1159                 if (IS_ERR(h))
1160                         return (void *)h;
1161         }
1162         ct = nf_ct_tuplehash_to_ctrack(h);
1163
1164         /* It exists; we have (non-exclusive) reference. */
1165         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1166                 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1167                 /* Please set reply bit if this packet OK */
1168                 *set_reply = 1;
1169         } else {
1170                 /* Once we've had two way comms, always ESTABLISHED. */
1171                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1172                         pr_debug("normal packet for %p\n", ct);
1173                         *ctinfo = IP_CT_ESTABLISHED;
1174                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1175                         pr_debug("related packet for %p\n", ct);
1176                         *ctinfo = IP_CT_RELATED;
1177                 } else {
1178                         pr_debug("new packet for %p\n", ct);
1179                         *ctinfo = IP_CT_NEW;
1180                 }
1181                 *set_reply = 0;
1182         }
1183         skb->nfct = &ct->ct_general;
1184         skb->nfctinfo = *ctinfo;
1185         return ct;
1186 }
1187
1188 unsigned int
1189 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1190                 struct sk_buff *skb)
1191 {
1192         struct nf_conn *ct, *tmpl = NULL;
1193         enum ip_conntrack_info ctinfo;
1194         struct nf_conntrack_l3proto *l3proto;
1195         struct nf_conntrack_l4proto *l4proto;
1196         unsigned int *timeouts;
1197         unsigned int dataoff;
1198         u_int8_t protonum;
1199         int set_reply = 0;
1200         int ret;
1201
1202         if (skb->nfct) {
1203                 /* Previously seen (loopback or untracked)?  Ignore. */
1204                 tmpl = (struct nf_conn *)skb->nfct;
1205                 if (!nf_ct_is_template(tmpl)) {
1206                         NF_CT_STAT_INC_ATOMIC(net, ignore);
1207                         return NF_ACCEPT;
1208                 }
1209                 skb->nfct = NULL;
1210         }
1211
1212         /* rcu_read_lock()ed by nf_hook_slow */
1213         l3proto = __nf_ct_l3proto_find(pf);
1214         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1215                                    &dataoff, &protonum);
1216         if (ret <= 0) {
1217                 pr_debug("not prepared to track yet or error occurred\n");
1218                 NF_CT_STAT_INC_ATOMIC(net, error);
1219                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1220                 ret = -ret;
1221                 goto out;
1222         }
1223
1224         l4proto = __nf_ct_l4proto_find(pf, protonum);
1225
1226         /* It may be an special packet, error, unclean...
1227          * inverse of the return code tells to the netfilter
1228          * core what to do with the packet. */
1229         if (l4proto->error != NULL) {
1230                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1231                                      pf, hooknum);
1232                 if (ret <= 0) {
1233                         NF_CT_STAT_INC_ATOMIC(net, error);
1234                         NF_CT_STAT_INC_ATOMIC(net, invalid);
1235                         ret = -ret;
1236                         goto out;
1237                 }
1238                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1239                 if (skb->nfct)
1240                         goto out;
1241         }
1242
1243         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1244                                l3proto, l4proto, &set_reply, &ctinfo);
1245         if (!ct) {
1246                 /* Not valid part of a connection */
1247                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1248                 ret = NF_ACCEPT;
1249                 goto out;
1250         }
1251
1252         if (IS_ERR(ct)) {
1253                 /* Too stressed to deal. */
1254                 NF_CT_STAT_INC_ATOMIC(net, drop);
1255                 ret = NF_DROP;
1256                 goto out;
1257         }
1258
1259         NF_CT_ASSERT(skb->nfct);
1260
1261         /* Decide what timeout policy we want to apply to this flow. */
1262         timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1263
1264         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1265         if (ret <= 0) {
1266                 /* Invalid: inverse of the return code tells
1267                  * the netfilter core what to do */
1268                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1269                 nf_conntrack_put(skb->nfct);
1270                 skb->nfct = NULL;
1271                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1272                 if (ret == -NF_DROP)
1273                         NF_CT_STAT_INC_ATOMIC(net, drop);
1274                 ret = -ret;
1275                 goto out;
1276         }
1277
1278         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1279                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1280 out:
1281         if (tmpl) {
1282                 /* Special case: we have to repeat this hook, assign the
1283                  * template again to this packet. We assume that this packet
1284                  * has no conntrack assigned. This is used by nf_ct_tcp. */
1285                 if (ret == NF_REPEAT)
1286                         skb->nfct = (struct nf_conntrack *)tmpl;
1287                 else
1288                         nf_ct_put(tmpl);
1289         }
1290
1291         return ret;
1292 }
1293 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1294
1295 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1296                           const struct nf_conntrack_tuple *orig)
1297 {
1298         bool ret;
1299
1300         rcu_read_lock();
1301         ret = nf_ct_invert_tuple(inverse, orig,
1302                                  __nf_ct_l3proto_find(orig->src.l3num),
1303                                  __nf_ct_l4proto_find(orig->src.l3num,
1304                                                       orig->dst.protonum));
1305         rcu_read_unlock();
1306         return ret;
1307 }
1308 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1309
1310 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1311    implicitly racy: see __nf_conntrack_confirm */
1312 void nf_conntrack_alter_reply(struct nf_conn *ct,
1313                               const struct nf_conntrack_tuple *newreply)
1314 {
1315         struct nf_conn_help *help = nfct_help(ct);
1316
1317         /* Should be unconfirmed, so not in hash table yet */
1318         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1319
1320         pr_debug("Altering reply tuple of %p to ", ct);
1321         nf_ct_dump_tuple(newreply);
1322
1323         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1324         if (ct->master || (help && !hlist_empty(&help->expectations)))
1325                 return;
1326
1327         rcu_read_lock();
1328         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1329         rcu_read_unlock();
1330 }
1331 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1332
1333 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1334 void __nf_ct_refresh_acct(struct nf_conn *ct,
1335                           enum ip_conntrack_info ctinfo,
1336                           const struct sk_buff *skb,
1337                           unsigned long extra_jiffies,
1338                           int do_acct)
1339 {
1340         NF_CT_ASSERT(skb);
1341
1342         /* Only update if this is not a fixed timeout */
1343         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1344                 goto acct;
1345
1346         /* If not in hash table, timer will not be active yet */
1347         if (nf_ct_is_confirmed(ct))
1348                 extra_jiffies += nfct_time_stamp;
1349
1350         ct->timeout = extra_jiffies;
1351 acct:
1352         if (do_acct)
1353                 nf_ct_acct_update(ct, ctinfo, skb->len);
1354 }
1355 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1356
1357 bool __nf_ct_kill_acct(struct nf_conn *ct,
1358                        enum ip_conntrack_info ctinfo,
1359                        const struct sk_buff *skb,
1360                        int do_acct)
1361 {
1362         if (do_acct)
1363                 nf_ct_acct_update(ct, ctinfo, skb->len);
1364
1365         return nf_ct_delete(ct, 0, 0);
1366 }
1367 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1368
1369 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1370
1371 #include <linux/netfilter/nfnetlink.h>
1372 #include <linux/netfilter/nfnetlink_conntrack.h>
1373 #include <linux/mutex.h>
1374
1375 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1376  * in ip_conntrack_core, since we don't want the protocols to autoload
1377  * or depend on ctnetlink */
1378 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1379                                const struct nf_conntrack_tuple *tuple)
1380 {
1381         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1382             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1383                 goto nla_put_failure;
1384         return 0;
1385
1386 nla_put_failure:
1387         return -1;
1388 }
1389 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1390
1391 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1392         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1393         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1394 };
1395 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1396
1397 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1398                                struct nf_conntrack_tuple *t)
1399 {
1400         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1401                 return -EINVAL;
1402
1403         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1404         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1405
1406         return 0;
1407 }
1408 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1409
1410 int nf_ct_port_nlattr_tuple_size(void)
1411 {
1412         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1413 }
1414 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1415 #endif
1416
1417 /* Used by ipt_REJECT and ip6t_REJECT. */
1418 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1419 {
1420         struct nf_conn *ct;
1421         enum ip_conntrack_info ctinfo;
1422
1423         /* This ICMP is in reverse direction to the packet which caused it */
1424         ct = nf_ct_get(skb, &ctinfo);
1425         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1426                 ctinfo = IP_CT_RELATED_REPLY;
1427         else
1428                 ctinfo = IP_CT_RELATED;
1429
1430         /* Attach to new skbuff, and increment count */
1431         nskb->nfct = &ct->ct_general;
1432         nskb->nfctinfo = ctinfo;
1433         nf_conntrack_get(nskb->nfct);
1434 }
1435
1436 /* Bring out ya dead! */
1437 static struct nf_conn *
1438 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1439                 void *data, unsigned int *bucket)
1440 {
1441         struct nf_conntrack_tuple_hash *h;
1442         struct nf_conn *ct;
1443         struct hlist_nulls_node *n;
1444         int cpu;
1445         spinlock_t *lockp;
1446
1447         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1448                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1449                 local_bh_disable();
1450                 nf_conntrack_lock(lockp);
1451                 if (*bucket < nf_conntrack_htable_size) {
1452                         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
1453                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1454                                         continue;
1455                                 ct = nf_ct_tuplehash_to_ctrack(h);
1456                                 if (net_eq(nf_ct_net(ct), net) &&
1457                                     iter(ct, data))
1458                                         goto found;
1459                         }
1460                 }
1461                 spin_unlock(lockp);
1462                 local_bh_enable();
1463                 cond_resched();
1464         }
1465
1466         for_each_possible_cpu(cpu) {
1467                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1468
1469                 spin_lock_bh(&pcpu->lock);
1470                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1471                         ct = nf_ct_tuplehash_to_ctrack(h);
1472                         if (iter(ct, data))
1473                                 set_bit(IPS_DYING_BIT, &ct->status);
1474                 }
1475                 spin_unlock_bh(&pcpu->lock);
1476                 cond_resched();
1477         }
1478         return NULL;
1479 found:
1480         atomic_inc(&ct->ct_general.use);
1481         spin_unlock(lockp);
1482         local_bh_enable();
1483         return ct;
1484 }
1485
1486 void nf_ct_iterate_cleanup(struct net *net,
1487                            int (*iter)(struct nf_conn *i, void *data),
1488                            void *data, u32 portid, int report)
1489 {
1490         struct nf_conn *ct;
1491         unsigned int bucket = 0;
1492
1493         might_sleep();
1494
1495         if (atomic_read(&net->ct.count) == 0)
1496                 return;
1497
1498         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1499                 /* Time to push up daises... */
1500
1501                 nf_ct_delete(ct, portid, report);
1502                 nf_ct_put(ct);
1503                 cond_resched();
1504         }
1505 }
1506 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1507
1508 static int kill_all(struct nf_conn *i, void *data)
1509 {
1510         return 1;
1511 }
1512
1513 void nf_ct_free_hashtable(void *hash, unsigned int size)
1514 {
1515         if (is_vmalloc_addr(hash))
1516                 vfree(hash);
1517         else
1518                 free_pages((unsigned long)hash,
1519                            get_order(sizeof(struct hlist_head) * size));
1520 }
1521 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1522
1523 static int untrack_refs(void)
1524 {
1525         int cnt = 0, cpu;
1526
1527         for_each_possible_cpu(cpu) {
1528                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1529
1530                 cnt += atomic_read(&ct->ct_general.use) - 1;
1531         }
1532         return cnt;
1533 }
1534
1535 void nf_conntrack_cleanup_start(void)
1536 {
1537         RCU_INIT_POINTER(ip_ct_attach, NULL);
1538 }
1539
1540 void nf_conntrack_cleanup_end(void)
1541 {
1542         RCU_INIT_POINTER(nf_ct_destroy, NULL);
1543         while (untrack_refs() > 0)
1544                 schedule();
1545
1546         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1547
1548         nf_conntrack_proto_fini();
1549         nf_conntrack_seqadj_fini();
1550         nf_conntrack_labels_fini();
1551         nf_conntrack_helper_fini();
1552         nf_conntrack_timeout_fini();
1553         nf_conntrack_ecache_fini();
1554         nf_conntrack_tstamp_fini();
1555         nf_conntrack_acct_fini();
1556         nf_conntrack_expect_fini();
1557
1558         kmem_cache_destroy(nf_conntrack_cachep);
1559 }
1560
1561 /*
1562  * Mishearing the voices in his head, our hero wonders how he's
1563  * supposed to kill the mall.
1564  */
1565 void nf_conntrack_cleanup_net(struct net *net)
1566 {
1567         LIST_HEAD(single);
1568
1569         list_add(&net->exit_list, &single);
1570         nf_conntrack_cleanup_net_list(&single);
1571 }
1572
1573 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1574 {
1575         int busy;
1576         struct net *net;
1577
1578         /*
1579          * This makes sure all current packets have passed through
1580          *  netfilter framework.  Roll on, two-stage module
1581          *  delete...
1582          */
1583         synchronize_net();
1584 i_see_dead_people:
1585         busy = 0;
1586         list_for_each_entry(net, net_exit_list, exit_list) {
1587                 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1588                 if (atomic_read(&net->ct.count) != 0)
1589                         busy = 1;
1590         }
1591         if (busy) {
1592                 schedule();
1593                 goto i_see_dead_people;
1594         }
1595
1596         list_for_each_entry(net, net_exit_list, exit_list) {
1597                 nf_conntrack_proto_pernet_fini(net);
1598                 nf_conntrack_helper_pernet_fini(net);
1599                 nf_conntrack_ecache_pernet_fini(net);
1600                 nf_conntrack_tstamp_pernet_fini(net);
1601                 nf_conntrack_acct_pernet_fini(net);
1602                 nf_conntrack_expect_pernet_fini(net);
1603                 free_percpu(net->ct.stat);
1604                 free_percpu(net->ct.pcpu_lists);
1605         }
1606 }
1607
1608 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1609 {
1610         struct hlist_nulls_head *hash;
1611         unsigned int nr_slots, i;
1612         size_t sz;
1613
1614         if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1615                 return NULL;
1616
1617         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1618         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1619
1620         if (nr_slots > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1621                 return NULL;
1622
1623         sz = nr_slots * sizeof(struct hlist_nulls_head);
1624         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1625                                         get_order(sz));
1626         if (!hash)
1627                 hash = vzalloc(sz);
1628
1629         if (hash && nulls)
1630                 for (i = 0; i < nr_slots; i++)
1631                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1632
1633         return hash;
1634 }
1635 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1636
1637 int nf_conntrack_hash_resize(unsigned int hashsize)
1638 {
1639         int i, bucket;
1640         unsigned int old_size;
1641         struct hlist_nulls_head *hash, *old_hash;
1642         struct nf_conntrack_tuple_hash *h;
1643         struct nf_conn *ct;
1644
1645         if (!hashsize)
1646                 return -EINVAL;
1647
1648         hash = nf_ct_alloc_hashtable(&hashsize, 1);
1649         if (!hash)
1650                 return -ENOMEM;
1651
1652         old_size = nf_conntrack_htable_size;
1653         if (old_size == hashsize) {
1654                 nf_ct_free_hashtable(hash, hashsize);
1655                 return 0;
1656         }
1657
1658         local_bh_disable();
1659         nf_conntrack_all_lock();
1660         write_seqcount_begin(&nf_conntrack_generation);
1661
1662         /* Lookups in the old hash might happen in parallel, which means we
1663          * might get false negatives during connection lookup. New connections
1664          * created because of a false negative won't make it into the hash
1665          * though since that required taking the locks.
1666          */
1667
1668         for (i = 0; i < nf_conntrack_htable_size; i++) {
1669                 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
1670                         h = hlist_nulls_entry(nf_conntrack_hash[i].first,
1671                                               struct nf_conntrack_tuple_hash, hnnode);
1672                         ct = nf_ct_tuplehash_to_ctrack(h);
1673                         hlist_nulls_del_rcu(&h->hnnode);
1674                         bucket = __hash_conntrack(nf_ct_net(ct),
1675                                                   &h->tuple, hashsize);
1676                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1677                 }
1678         }
1679         old_size = nf_conntrack_htable_size;
1680         old_hash = nf_conntrack_hash;
1681
1682         nf_conntrack_hash = hash;
1683         nf_conntrack_htable_size = hashsize;
1684
1685         write_seqcount_end(&nf_conntrack_generation);
1686         nf_conntrack_all_unlock();
1687         local_bh_enable();
1688
1689         synchronize_net();
1690         nf_ct_free_hashtable(old_hash, old_size);
1691         return 0;
1692 }
1693
1694 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1695 {
1696         unsigned int hashsize;
1697         int rc;
1698
1699         if (current->nsproxy->net_ns != &init_net)
1700                 return -EOPNOTSUPP;
1701
1702         /* On boot, we can set this without any fancy locking. */
1703         if (!nf_conntrack_htable_size)
1704                 return param_set_uint(val, kp);
1705
1706         rc = kstrtouint(val, 0, &hashsize);
1707         if (rc)
1708                 return rc;
1709
1710         return nf_conntrack_hash_resize(hashsize);
1711 }
1712 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1713
1714 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1715                   &nf_conntrack_htable_size, 0600);
1716
1717 void nf_ct_untracked_status_or(unsigned long bits)
1718 {
1719         int cpu;
1720
1721         for_each_possible_cpu(cpu)
1722                 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1723 }
1724 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1725
1726 int nf_conntrack_init_start(void)
1727 {
1728         int max_factor = 8;
1729         int ret = -ENOMEM;
1730         int i, cpu;
1731
1732         seqcount_init(&nf_conntrack_generation);
1733
1734         for (i = 0; i < CONNTRACK_LOCKS; i++)
1735                 spin_lock_init(&nf_conntrack_locks[i]);
1736
1737         if (!nf_conntrack_htable_size) {
1738                 /* Idea from tcp.c: use 1/16384 of memory.
1739                  * On i386: 32MB machine has 512 buckets.
1740                  * >= 1GB machines have 16384 buckets.
1741                  * >= 4GB machines have 65536 buckets.
1742                  */
1743                 nf_conntrack_htable_size
1744                         = (((totalram_pages << PAGE_SHIFT) / 16384)
1745                            / sizeof(struct hlist_head));
1746                 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1747                         nf_conntrack_htable_size = 65536;
1748                 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1749                         nf_conntrack_htable_size = 16384;
1750                 if (nf_conntrack_htable_size < 32)
1751                         nf_conntrack_htable_size = 32;
1752
1753                 /* Use a max. factor of four by default to get the same max as
1754                  * with the old struct list_heads. When a table size is given
1755                  * we use the old value of 8 to avoid reducing the max.
1756                  * entries. */
1757                 max_factor = 4;
1758         }
1759
1760         nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
1761         if (!nf_conntrack_hash)
1762                 return -ENOMEM;
1763
1764         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1765
1766         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1767                                                 sizeof(struct nf_conn), 0,
1768                                                 SLAB_DESTROY_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
1769         if (!nf_conntrack_cachep)
1770                 goto err_cachep;
1771
1772         printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1773                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1774                nf_conntrack_max);
1775
1776         ret = nf_conntrack_expect_init();
1777         if (ret < 0)
1778                 goto err_expect;
1779
1780         ret = nf_conntrack_acct_init();
1781         if (ret < 0)
1782                 goto err_acct;
1783
1784         ret = nf_conntrack_tstamp_init();
1785         if (ret < 0)
1786                 goto err_tstamp;
1787
1788         ret = nf_conntrack_ecache_init();
1789         if (ret < 0)
1790                 goto err_ecache;
1791
1792         ret = nf_conntrack_timeout_init();
1793         if (ret < 0)
1794                 goto err_timeout;
1795
1796         ret = nf_conntrack_helper_init();
1797         if (ret < 0)
1798                 goto err_helper;
1799
1800         ret = nf_conntrack_labels_init();
1801         if (ret < 0)
1802                 goto err_labels;
1803
1804         ret = nf_conntrack_seqadj_init();
1805         if (ret < 0)
1806                 goto err_seqadj;
1807
1808         ret = nf_conntrack_proto_init();
1809         if (ret < 0)
1810                 goto err_proto;
1811
1812         /* Set up fake conntrack: to never be deleted, not in any hashes */
1813         for_each_possible_cpu(cpu) {
1814                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1815                 write_pnet(&ct->ct_net, &init_net);
1816                 atomic_set(&ct->ct_general.use, 1);
1817         }
1818         /*  - and look it like as a confirmed connection */
1819         nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1820         return 0;
1821
1822 err_proto:
1823         nf_conntrack_seqadj_fini();
1824 err_seqadj:
1825         nf_conntrack_labels_fini();
1826 err_labels:
1827         nf_conntrack_helper_fini();
1828 err_helper:
1829         nf_conntrack_timeout_fini();
1830 err_timeout:
1831         nf_conntrack_ecache_fini();
1832 err_ecache:
1833         nf_conntrack_tstamp_fini();
1834 err_tstamp:
1835         nf_conntrack_acct_fini();
1836 err_acct:
1837         nf_conntrack_expect_fini();
1838 err_expect:
1839         kmem_cache_destroy(nf_conntrack_cachep);
1840 err_cachep:
1841         nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1842         return ret;
1843 }
1844
1845 void nf_conntrack_init_end(void)
1846 {
1847         /* For use by REJECT target */
1848         RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1849         RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1850 }
1851
1852 /*
1853  * We need to use special "null" values, not used in hash table
1854  */
1855 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
1856 #define DYING_NULLS_VAL         ((1<<30)+1)
1857 #define TEMPLATE_NULLS_VAL      ((1<<30)+2)
1858
1859 int nf_conntrack_init_net(struct net *net)
1860 {
1861         int ret = -ENOMEM;
1862         int cpu;
1863
1864         atomic_set(&net->ct.count, 0);
1865
1866         net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1867         if (!net->ct.pcpu_lists)
1868                 goto err_stat;
1869
1870         for_each_possible_cpu(cpu) {
1871                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1872
1873                 spin_lock_init(&pcpu->lock);
1874                 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1875                 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1876         }
1877
1878         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1879         if (!net->ct.stat)
1880                 goto err_pcpu_lists;
1881
1882         ret = nf_conntrack_expect_pernet_init(net);
1883         if (ret < 0)
1884                 goto err_expect;
1885         ret = nf_conntrack_acct_pernet_init(net);
1886         if (ret < 0)
1887                 goto err_acct;
1888         ret = nf_conntrack_tstamp_pernet_init(net);
1889         if (ret < 0)
1890                 goto err_tstamp;
1891         ret = nf_conntrack_ecache_pernet_init(net);
1892         if (ret < 0)
1893                 goto err_ecache;
1894         ret = nf_conntrack_helper_pernet_init(net);
1895         if (ret < 0)
1896                 goto err_helper;
1897         ret = nf_conntrack_proto_pernet_init(net);
1898         if (ret < 0)
1899                 goto err_proto;
1900         return 0;
1901
1902 err_proto:
1903         nf_conntrack_helper_pernet_fini(net);
1904 err_helper:
1905         nf_conntrack_ecache_pernet_fini(net);
1906 err_ecache:
1907         nf_conntrack_tstamp_pernet_fini(net);
1908 err_tstamp:
1909         nf_conntrack_acct_pernet_fini(net);
1910 err_acct:
1911         nf_conntrack_expect_pernet_fini(net);
1912 err_expect:
1913         free_percpu(net->ct.stat);
1914 err_pcpu_lists:
1915         free_percpu(net->ct.pcpu_lists);
1916 err_stat:
1917         return ret;
1918 }