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