kernel/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 #include <linux/types.h>
  16 #include <linux/netfilter.h>
  17 #include <linux/module.h>
  18 #include <linux/sched.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/stddef.h>
  23 #include <linux/slab.h>
  24 #include <linux/random.h>
  25 #include <linux/jhash.h>
  26 #include <linux/err.h>
  27 #include <linux/percpu.h>
  28 #include <linux/moduleparam.h>
  29 #include <linux/notifier.h>
  30 #include <linux/kernel.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/socket.h>
  33 #include <linux/mm.h>
  34 #include <linux/nsproxy.h>
  35 #include <linux/rculist_nulls.h>
  36
  37 #include <net/netfilter/nf_conntrack.h>
  38 #include <net/netfilter/nf_conntrack_l3proto.h>
  39 #include <net/netfilter/nf_conntrack_l4proto.h>
  40 #include <net/netfilter/nf_conntrack_expect.h>
  41 #include <net/netfilter/nf_conntrack_helper.h>
  42 #include <net/netfilter/nf_conntrack_seqadj.h>
  43 #include <net/netfilter/nf_conntrack_core.h>
  44 #include <net/netfilter/nf_conntrack_extend.h>
  45 #include <net/netfilter/nf_conntrack_acct.h>
  46 #include <net/netfilter/nf_conntrack_ecache.h>
  47 #include <net/netfilter/nf_conntrack_zones.h>
  48 #include <net/netfilter/nf_conntrack_timestamp.h>
  49 #include <net/netfilter/nf_conntrack_timeout.h>
  50 #include <net/netfilter/nf_conntrack_labels.h>
  51 #include <net/netfilter/nf_conntrack_synproxy.h>
  52 #include <net/netfilter/nf_nat.h>
  53 #include <net/netfilter/nf_nat_core.h>
  54 #include <net/netfilter/nf_nat_helper.h>
  55
  56 #define NF_CONNTRACK_VERSION    "0.5.0"
  57
  58 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
  59                                       enum nf_nat_manip_type manip,
  60                                       const struct nlattr *attr) __read_mostly;
  61 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
  62
  63 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
  64 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
  65
  66 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
  67 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
  68
  69 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
  70 {
  71         h1 %= CONNTRACK_LOCKS;
  72         h2 %= CONNTRACK_LOCKS;
  73         spin_unlock(&nf_conntrack_locks[h1]);
  74         if (h1 != h2)
  75                 spin_unlock(&nf_conntrack_locks[h2]);
  76 }
  77
  78 /* return true if we need to recompute hashes (in case hash table was resized) */
  79 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
  80                                      unsigned int h2, unsigned int sequence)
  81 {
  82         h1 %= CONNTRACK_LOCKS;
  83         h2 %= CONNTRACK_LOCKS;
  84         if (h1 <= h2) {
  85                 spin_lock(&nf_conntrack_locks[h1]);
  86                 if (h1 != h2)
  87                         spin_lock_nested(&nf_conntrack_locks[h2],
  88                                          SINGLE_DEPTH_NESTING);
  89         } else {
  90                 spin_lock(&nf_conntrack_locks[h2]);
  91                 spin_lock_nested(&nf_conntrack_locks[h1],
  92                                  SINGLE_DEPTH_NESTING);
  93         }
  94         if (read_seqcount_retry(&net->ct.generation, sequence)) {
  95                 nf_conntrack_double_unlock(h1, h2);
  96                 return true;
  97         }
  98         return false;
  99 }
 100
 101 static void nf_conntrack_all_lock(void)
 102 {
 103         int i;
 104
 105         for (i = 0; i < CONNTRACK_LOCKS; i++)
 106                 spin_lock_nested(&nf_conntrack_locks[i], i);
 107 }
 108
 109 static void nf_conntrack_all_unlock(void)
 110 {
 111         int i;
 112
 113         for (i = 0; i < CONNTRACK_LOCKS; i++)
 114                 spin_unlock(&nf_conntrack_locks[i]);
 115 }
 116
 117 unsigned int nf_conntrack_htable_size __read_mostly;
 118 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
 119
 120 unsigned int nf_conntrack_max __read_mostly;
 121 EXPORT_SYMBOL_GPL(nf_conntrack_max);
 122
 123 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 124 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
 125
 126 unsigned int nf_conntrack_hash_rnd __read_mostly;
 127 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
 128
 129 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple)
 130 {
 131         unsigned int n;
 132
 133         /* The direction must be ignored, so we hash everything up to the
 134          * destination ports (which is a multiple of 4) and treat the last
 135          * three bytes manually.
 136          */
 137         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
 138         return jhash2((u32 *)tuple, n, nf_conntrack_hash_rnd ^
 139                       (((__force __u16)tuple->dst.u.all << 16) |
 140                       tuple->dst.protonum));
 141 }
 142
 143 static u32 __hash_bucket(u32 hash, unsigned int size)
 144 {
 145         return reciprocal_scale(hash, size);
 146 }
 147
 148 static u32 hash_bucket(u32 hash, const struct net *net)
 149 {
 150         return __hash_bucket(hash, net->ct.htable_size);
 151 }
 152
 153 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
 154                                   unsigned int size)
 155 {
 156         return __hash_bucket(hash_conntrack_raw(tuple), size);
 157 }
 158
 159 static inline u_int32_t hash_conntrack(const struct net *net,
 160                                        const struct nf_conntrack_tuple *tuple)
 161 {
 162         return __hash_conntrack(tuple, net->ct.htable_size);
 163 }
 164
 165 bool
 166 nf_ct_get_tuple(const struct sk_buff *skb,
 167                 unsigned int nhoff,
 168                 unsigned int dataoff,
 169                 u_int16_t l3num,
 170                 u_int8_t protonum,
 171                 struct net *net,
 172                 struct nf_conntrack_tuple *tuple,
 173                 const struct nf_conntrack_l3proto *l3proto,
 174                 const struct nf_conntrack_l4proto *l4proto)
 175 {
 176         memset(tuple, 0, sizeof(*tuple));
 177
 178         tuple->src.l3num = l3num;
 179         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 180                 return false;
 181
 182         tuple->dst.protonum = protonum;
 183         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 184
 185         return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
 186 }
 187 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 188
 189 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 190                        u_int16_t l3num,
 191                        struct net *net, struct nf_conntrack_tuple *tuple)
 192 {
 193         struct nf_conntrack_l3proto *l3proto;
 194         struct nf_conntrack_l4proto *l4proto;
 195         unsigned int protoff;
 196         u_int8_t protonum;
 197         int ret;
 198
 199         rcu_read_lock();
 200
 201         l3proto = __nf_ct_l3proto_find(l3num);
 202         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 203         if (ret != NF_ACCEPT) {
 204                 rcu_read_unlock();
 205                 return false;
 206         }
 207
 208         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 209
 210         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
 211                               l3proto, l4proto);
 212
 213         rcu_read_unlock();
 214         return ret;
 215 }
 216 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 217
 218 bool
 219 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 220                    const struct nf_conntrack_tuple *orig,
 221                    const struct nf_conntrack_l3proto *l3proto,
 222                    const struct nf_conntrack_l4proto *l4proto)
 223 {
 224         memset(inverse, 0, sizeof(*inverse));
 225
 226         inverse->src.l3num = orig->src.l3num;
 227         if (l3proto->invert_tuple(inverse, orig) == 0)
 228                 return false;
 229
 230         inverse->dst.dir = !orig->dst.dir;
 231
 232         inverse->dst.protonum = orig->dst.protonum;
 233         return l4proto->invert_tuple(inverse, orig);
 234 }
 235 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 236
 237 static void
 238 clean_from_lists(struct nf_conn *ct)
 239 {
 240         pr_debug("clean_from_lists(%p)\n", ct);
 241         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 242         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 243
 244         /* Destroy all pending expectations */
 245         nf_ct_remove_expectations(ct);
 246 }
 247
 248 /* must be called with local_bh_disable */
 249 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
 250 {
 251         struct ct_pcpu *pcpu;
 252
 253         /* add this conntrack to the (per cpu) dying list */
 254         ct->cpu = smp_processor_id();
 255         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 256
 257         spin_lock(&pcpu->lock);
 258         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 259                              &pcpu->dying);
 260         spin_unlock(&pcpu->lock);
 261 }
 262
 263 /* must be called with local_bh_disable */
 264 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
 265 {
 266         struct ct_pcpu *pcpu;
 267
 268         /* add this conntrack to the (per cpu) unconfirmed list */
 269         ct->cpu = smp_processor_id();
 270         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 271
 272         spin_lock(&pcpu->lock);
 273         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 274                              &pcpu->unconfirmed);
 275         spin_unlock(&pcpu->lock);
 276 }
 277
 278 /* must be called with local_bh_disable */
 279 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
 280 {
 281         struct ct_pcpu *pcpu;
 282
 283         /* We overload first tuple to link into unconfirmed or dying list.*/
 284         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 285
 286         spin_lock(&pcpu->lock);
 287         BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 288         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 289         spin_unlock(&pcpu->lock);
 290 }
 291
 292 /* Released via destroy_conntrack() */
 293 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
 294                                  const struct nf_conntrack_zone *zone,
 295                                  gfp_t flags)
 296 {
 297         struct nf_conn *tmpl;
 298
 299         tmpl = kzalloc(sizeof(*tmpl), flags);
 300         if (tmpl == NULL)
 301                 return NULL;
 302
 303         tmpl->status = IPS_TEMPLATE;
 304         write_pnet(&tmpl->ct_net, net);
 305
 306         if (nf_ct_zone_add(tmpl, flags, zone) < 0)
 307                 goto out_free;
 308
 309         atomic_set(&tmpl->ct_general.use, 0);
 310
 311         return tmpl;
 312 out_free:
 313         kfree(tmpl);
 314         return NULL;
 315 }
 316 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
 317
 318 void nf_ct_tmpl_free(struct nf_conn *tmpl)
 319 {
 320         nf_ct_ext_destroy(tmpl);
 321         nf_ct_ext_free(tmpl);
 322         kfree(tmpl);
 323 }
 324 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
 325
 326 static void
 327 destroy_conntrack(struct nf_conntrack *nfct)
 328 {
 329         struct nf_conn *ct = (struct nf_conn *)nfct;
 330         struct net *net = nf_ct_net(ct);
 331         struct nf_conntrack_l4proto *l4proto;
 332
 333         pr_debug("destroy_conntrack(%p)\n", ct);
 334         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 335         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 336
 337         if (unlikely(nf_ct_is_template(ct))) {
 338                 nf_ct_tmpl_free(ct);
 339                 return;
 340         }
 341         rcu_read_lock();
 342         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 343         if (l4proto && l4proto->destroy)
 344                 l4proto->destroy(ct);
 345
 346         rcu_read_unlock();
 347
 348         local_bh_disable();
 349         /* Expectations will have been removed in clean_from_lists,
 350          * except TFTP can create an expectation on the first packet,
 351          * before connection is in the list, so we need to clean here,
 352          * too.
 353          */
 354         nf_ct_remove_expectations(ct);
 355
 356         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 357
 358         NF_CT_STAT_INC(net, delete);
 359         local_bh_enable();
 360
 361         if (ct->master)
 362                 nf_ct_put(ct->master);
 363
 364         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 365         nf_conntrack_free(ct);
 366 }
 367
 368 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 369 {
 370         struct net *net = nf_ct_net(ct);
 371         unsigned int hash, reply_hash;
 372         unsigned int sequence;
 373
 374         nf_ct_helper_destroy(ct);
 375
 376         local_bh_disable();
 377         do {
 378                 sequence = read_seqcount_begin(&net->ct.generation);
 379                 hash = hash_conntrack(net,
 380                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 381                 reply_hash = hash_conntrack(net,
 382                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 383         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 384
 385         clean_from_lists(ct);
 386         nf_conntrack_double_unlock(hash, reply_hash);
 387
 388         nf_ct_add_to_dying_list(ct);
 389
 390         NF_CT_STAT_INC(net, delete_list);
 391         local_bh_enable();
 392 }
 393
 394 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 395 {
 396         struct nf_conn_tstamp *tstamp;
 397
 398         tstamp = nf_conn_tstamp_find(ct);
 399         if (tstamp && tstamp->stop == 0)
 400                 tstamp->stop = ktime_get_real_ns();
 401
 402         if (nf_ct_is_dying(ct))
 403                 goto delete;
 404
 405         if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 406                                     portid, report) < 0) {
 407                 /* destroy event was not delivered */
 408                 nf_ct_delete_from_lists(ct);
 409                 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
 410                 return false;
 411         }
 412
 413         nf_conntrack_ecache_work(nf_ct_net(ct));
 414         set_bit(IPS_DYING_BIT, &ct->status);
 415  delete:
 416         nf_ct_delete_from_lists(ct);
 417         nf_ct_put(ct);
 418         return true;
 419 }
 420 EXPORT_SYMBOL_GPL(nf_ct_delete);
 421
 422 static void death_by_timeout(unsigned long ul_conntrack)
 423 {
 424         nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
 425 }
 426
 427 static inline bool
 428 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 429                 const struct nf_conntrack_tuple *tuple,
 430                 const struct nf_conntrack_zone *zone)
 431 {
 432         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 433
 434         /* A conntrack can be recreated with the equal tuple,
 435          * so we need to check that the conntrack is confirmed
 436          */
 437         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 438                nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
 439                nf_ct_is_confirmed(ct);
 440 }
 441
 442 /*
 443  * Warning :
 444  * - Caller must take a reference on returned object
 445  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 446  */
 447 static struct nf_conntrack_tuple_hash *
 448 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
 449                       const struct nf_conntrack_tuple *tuple, u32 hash)
 450 {
 451         struct nf_conntrack_tuple_hash *h;
 452         struct hlist_nulls_node *n;
 453         unsigned int bucket = hash_bucket(hash, net);
 454
 455         /* Disable BHs the entire time since we normally need to disable them
 456          * at least once for the stats anyway.
 457          */
 458         local_bh_disable();
 459 begin:
 460         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
 461                 if (nf_ct_key_equal(h, tuple, zone)) {
 462                         NF_CT_STAT_INC(net, found);
 463                         local_bh_enable();
 464                         return h;
 465                 }
 466                 NF_CT_STAT_INC(net, searched);
 467         }
 468         /*
 469          * if the nulls value we got at the end of this lookup is
 470          * not the expected one, we must restart lookup.
 471          * We probably met an item that was moved to another chain.
 472          */
 473         if (get_nulls_value(n) != bucket) {
 474                 NF_CT_STAT_INC(net, search_restart);
 475                 goto begin;
 476         }
 477         local_bh_enable();
 478
 479         return NULL;
 480 }
 481
 482 /* Find a connection corresponding to a tuple. */
 483 static struct nf_conntrack_tuple_hash *
 484 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 485                         const struct nf_conntrack_tuple *tuple, u32 hash)
 486 {
 487         struct nf_conntrack_tuple_hash *h;
 488         struct nf_conn *ct;
 489
 490         rcu_read_lock();
 491 begin:
 492         h = ____nf_conntrack_find(net, zone, tuple, hash);
 493         if (h) {
 494                 ct = nf_ct_tuplehash_to_ctrack(h);
 495                 if (unlikely(nf_ct_is_dying(ct) ||
 496                              !atomic_inc_not_zero(&ct->ct_general.use)))
 497                         h = NULL;
 498                 else {
 499                         if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
 500                                 nf_ct_put(ct);
 501                                 goto begin;
 502                         }
 503                 }
 504         }
 505         rcu_read_unlock();
 506
 507         return h;
 508 }
 509
 510 struct nf_conntrack_tuple_hash *
 511 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 512                       const struct nf_conntrack_tuple *tuple)
 513 {
 514         return __nf_conntrack_find_get(net, zone, tuple,
 515                                        hash_conntrack_raw(tuple));
 516 }
 517 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 518
 519 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 520                                        unsigned int hash,
 521                                        unsigned int reply_hash)
 522 {
 523         struct net *net = nf_ct_net(ct);
 524
 525         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 526                            &net->ct.hash[hash]);
 527         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 528                            &net->ct.hash[reply_hash]);
 529 }
 530
 531 int
 532 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 533 {
 534         const struct nf_conntrack_zone *zone;
 535         struct net *net = nf_ct_net(ct);
 536         unsigned int hash, reply_hash;
 537         struct nf_conntrack_tuple_hash *h;
 538         struct hlist_nulls_node *n;
 539         unsigned int sequence;
 540
 541         zone = nf_ct_zone(ct);
 542
 543         local_bh_disable();
 544         do {
 545                 sequence = read_seqcount_begin(&net->ct.generation);
 546                 hash = hash_conntrack(net,
 547                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 548                 reply_hash = hash_conntrack(net,
 549                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 550         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 551
 552         /* See if there's one in the list already, including reverse */
 553         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 554                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 555                                       &h->tuple) &&
 556                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 557                                      NF_CT_DIRECTION(h)))
 558                         goto out;
 559         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 560                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 561                                       &h->tuple) &&
 562                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 563                                      NF_CT_DIRECTION(h)))
 564                         goto out;
 565
 566         add_timer(&ct->timeout);
 567         smp_wmb();
 568         /* The caller holds a reference to this object */
 569         atomic_set(&ct->ct_general.use, 2);
 570         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 571         nf_conntrack_double_unlock(hash, reply_hash);
 572         NF_CT_STAT_INC(net, insert);
 573         local_bh_enable();
 574         return 0;
 575
 576 out:
 577         nf_conntrack_double_unlock(hash, reply_hash);
 578         NF_CT_STAT_INC(net, insert_failed);
 579         local_bh_enable();
 580         return -EEXIST;
 581 }
 582 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 583
 584 /* Confirm a connection given skb; places it in hash table */
 585 int
 586 __nf_conntrack_confirm(struct sk_buff *skb)
 587 {
 588         const struct nf_conntrack_zone *zone;
 589         unsigned int hash, reply_hash;
 590         struct nf_conntrack_tuple_hash *h;
 591         struct nf_conn *ct;
 592         struct nf_conn_help *help;
 593         struct nf_conn_tstamp *tstamp;
 594         struct hlist_nulls_node *n;
 595         enum ip_conntrack_info ctinfo;
 596         struct net *net;
 597         unsigned int sequence;
 598
 599         ct = nf_ct_get(skb, &ctinfo);
 600         net = nf_ct_net(ct);
 601
 602         /* ipt_REJECT uses nf_conntrack_attach to attach related
 603            ICMP/TCP RST packets in other direction.  Actual packet
 604            which created connection will be IP_CT_NEW or for an
 605            expected connection, IP_CT_RELATED. */
 606         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 607                 return NF_ACCEPT;
 608
 609         zone = nf_ct_zone(ct);
 610         local_bh_disable();
 611
 612         do {
 613                 sequence = read_seqcount_begin(&net->ct.generation);
 614                 /* reuse the hash saved before */
 615                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 616                 hash = hash_bucket(hash, net);
 617                 reply_hash = hash_conntrack(net,
 618                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 619
 620         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 621
 622         /* We're not in hash table, and we refuse to set up related
 623          * connections for unconfirmed conns.  But packet copies and
 624          * REJECT will give spurious warnings here.
 625          */
 626         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 627
 628         /* No external references means no one else could have
 629          * confirmed us.
 630          */
 631         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 632         pr_debug("Confirming conntrack %p\n", ct);
 633         /* We have to check the DYING flag after unlink to prevent
 634          * a race against nf_ct_get_next_corpse() possibly called from
 635          * user context, else we insert an already 'dead' hash, blocking
 636          * further use of that particular connection -JM.
 637          */
 638         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 639
 640         if (unlikely(nf_ct_is_dying(ct)))
 641                 goto out;
 642
 643         /* See if there's one in the list already, including reverse:
 644            NAT could have grabbed it without realizing, since we're
 645            not in the hash.  If there is, we lost race. */
 646         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 647                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 648                                       &h->tuple) &&
 649                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 650                                      NF_CT_DIRECTION(h)))
 651                         goto out;
 652         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 653                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 654                                       &h->tuple) &&
 655                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 656                                      NF_CT_DIRECTION(h)))
 657                         goto out;
 658
 659         /* Timer relative to confirmation time, not original
 660            setting time, otherwise we'd get timer wrap in
 661            weird delay cases. */
 662         ct->timeout.expires += jiffies;
 663         add_timer(&ct->timeout);
 664         atomic_inc(&ct->ct_general.use);
 665         ct->status |= IPS_CONFIRMED;
 666
 667         /* set conntrack timestamp, if enabled. */
 668         tstamp = nf_conn_tstamp_find(ct);
 669         if (tstamp) {
 670                 if (skb->tstamp.tv64 == 0)
 671                         __net_timestamp(skb);
 672
 673                 tstamp->start = ktime_to_ns(skb->tstamp);
 674         }
 675         /* Since the lookup is lockless, hash insertion must be done after
 676          * starting the timer and setting the CONFIRMED bit. The RCU barriers
 677          * guarantee that no other CPU can find the conntrack before the above
 678          * stores are visible.
 679          */
 680         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 681         nf_conntrack_double_unlock(hash, reply_hash);
 682         NF_CT_STAT_INC(net, insert);
 683         local_bh_enable();
 684
 685         help = nfct_help(ct);
 686         if (help && help->helper)
 687                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 688
 689         nf_conntrack_event_cache(master_ct(ct) ?
 690                                  IPCT_RELATED : IPCT_NEW, ct);
 691         return NF_ACCEPT;
 692
 693 out:
 694         nf_ct_add_to_dying_list(ct);
 695         nf_conntrack_double_unlock(hash, reply_hash);
 696         NF_CT_STAT_INC(net, insert_failed);
 697         local_bh_enable();
 698         return NF_DROP;
 699 }
 700 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 701
 702 /* Returns true if a connection correspondings to the tuple (required
 703    for NAT). */
 704 int
 705 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 706                          const struct nf_conn *ignored_conntrack)
 707 {
 708         struct net *net = nf_ct_net(ignored_conntrack);
 709         const struct nf_conntrack_zone *zone;
 710         struct nf_conntrack_tuple_hash *h;
 711         struct hlist_nulls_node *n;
 712         struct nf_conn *ct;
 713         unsigned int hash;
 714
 715         zone = nf_ct_zone(ignored_conntrack);
 716         hash = hash_conntrack(net, tuple);
 717
 718         /* Disable BHs the entire time since we need to disable them at
 719          * least once for the stats anyway.
 720          */
 721         rcu_read_lock_bh();
 722         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 723                 ct = nf_ct_tuplehash_to_ctrack(h);
 724                 if (ct != ignored_conntrack &&
 725                     nf_ct_tuple_equal(tuple, &h->tuple) &&
 726                     nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
 727                         NF_CT_STAT_INC(net, found);
 728                         rcu_read_unlock_bh();
 729                         return 1;
 730                 }
 731                 NF_CT_STAT_INC(net, searched);
 732         }
 733         rcu_read_unlock_bh();
 734
 735         return 0;
 736 }
 737 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 738
 739 #define NF_CT_EVICTION_RANGE    8
 740
 741 /* There's a small race here where we may free a just-assured
 742    connection.  Too bad: we're in trouble anyway. */
 743 static noinline int early_drop(struct net *net, unsigned int _hash)
 744 {
 745         /* Use oldest entry, which is roughly LRU */
 746         struct nf_conntrack_tuple_hash *h;
 747         struct nf_conn *ct = NULL, *tmp;
 748         struct hlist_nulls_node *n;
 749         unsigned int i = 0, cnt = 0;
 750         int dropped = 0;
 751         unsigned int hash, sequence;
 752         spinlock_t *lockp;
 753
 754         local_bh_disable();
 755 restart:
 756         sequence = read_seqcount_begin(&net->ct.generation);
 757         hash = hash_bucket(_hash, net);
 758         for (; i < net->ct.htable_size; i++) {
 759                 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
 760                 spin_lock(lockp);
 761                 if (read_seqcount_retry(&net->ct.generation, sequence)) {
 762                         spin_unlock(lockp);
 763                         goto restart;
 764                 }
 765                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 766                                          hnnode) {
 767                         tmp = nf_ct_tuplehash_to_ctrack(h);
 768                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
 769                             !nf_ct_is_dying(tmp) &&
 770                             atomic_inc_not_zero(&tmp->ct_general.use)) {
 771                                 ct = tmp;
 772                                 break;
 773                         }
 774                         cnt++;
 775                 }
 776
 777                 hash = (hash + 1) % net->ct.htable_size;
 778                 spin_unlock(lockp);
 779
 780                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 781                         break;
 782
 783         }
 784         local_bh_enable();
 785
 786         if (!ct)
 787                 return dropped;
 788
 789         if (del_timer(&ct->timeout)) {
 790                 if (nf_ct_delete(ct, 0, 0)) {
 791                         dropped = 1;
 792                         NF_CT_STAT_INC_ATOMIC(net, early_drop);
 793                 }
 794         }
 795         nf_ct_put(ct);
 796         return dropped;
 797 }
 798
 799 void init_nf_conntrack_hash_rnd(void)
 800 {
 801         unsigned int rand;
 802
 803         /*
 804          * Why not initialize nf_conntrack_rnd in a "init()" function ?
 805          * Because there isn't enough entropy when system initializing,
 806          * and we initialize it as late as possible.
 807          */
 808         do {
 809                 get_random_bytes(&rand, sizeof(rand));
 810         } while (!rand);
 811         cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
 812 }
 813
 814 static struct nf_conn *
 815 __nf_conntrack_alloc(struct net *net,
 816                      const struct nf_conntrack_zone *zone,
 817                      const struct nf_conntrack_tuple *orig,
 818                      const struct nf_conntrack_tuple *repl,
 819                      gfp_t gfp, u32 hash)
 820 {
 821         struct nf_conn *ct;
 822
 823         if (unlikely(!nf_conntrack_hash_rnd)) {
 824                 init_nf_conntrack_hash_rnd();
 825                 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
 826                 hash = hash_conntrack_raw(orig);
 827         }
 828
 829         /* We don't want any race condition at early drop stage */
 830         atomic_inc(&net->ct.count);
 831
 832         if (nf_conntrack_max &&
 833             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 834                 if (!early_drop(net, hash)) {
 835                         atomic_dec(&net->ct.count);
 836                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
 837                         return ERR_PTR(-ENOMEM);
 838                 }
 839         }
 840
 841         /*
 842          * Do not use kmem_cache_zalloc(), as this cache uses
 843          * SLAB_DESTROY_BY_RCU.
 844          */
 845         ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
 846         if (ct == NULL)
 847                 goto out;
 848
 849         spin_lock_init(&ct->lock);
 850         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 851         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
 852         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 853         /* save hash for reusing when confirming */
 854         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 855         ct->status = 0;
 856         /* Don't set timer yet: wait for confirmation */
 857         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 858         write_pnet(&ct->ct_net, net);
 859         memset(&ct->__nfct_init_offset[0], 0,
 860                offsetof(struct nf_conn, proto) -
 861                offsetof(struct nf_conn, __nfct_init_offset[0]));
 862
 863         if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
 864                 goto out_free;
 865
 866         /* Because we use RCU lookups, we set ct_general.use to zero before
 867          * this is inserted in any list.
 868          */
 869         atomic_set(&ct->ct_general.use, 0);
 870         return ct;
 871 out_free:
 872         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 873 out:
 874         atomic_dec(&net->ct.count);
 875         return ERR_PTR(-ENOMEM);
 876 }
 877
 878 struct nf_conn *nf_conntrack_alloc(struct net *net,
 879                                    const struct nf_conntrack_zone *zone,
 880                                    const struct nf_conntrack_tuple *orig,
 881                                    const struct nf_conntrack_tuple *repl,
 882                                    gfp_t gfp)
 883 {
 884         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
 885 }
 886 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 887
 888 void nf_conntrack_free(struct nf_conn *ct)
 889 {
 890         struct net *net = nf_ct_net(ct);
 891
 892         /* A freed object has refcnt == 0, that's
 893          * the golden rule for SLAB_DESTROY_BY_RCU
 894          */
 895         NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
 896
 897         nf_ct_ext_destroy(ct);
 898         nf_ct_ext_free(ct);
 899         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 900         smp_mb__before_atomic();
 901         atomic_dec(&net->ct.count);
 902 }
 903 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 904
 905
 906 /* Allocate a new conntrack: we return -ENOMEM if classification
 907    failed due to stress.  Otherwise it really is unclassifiable. */
 908 static struct nf_conntrack_tuple_hash *
 909 init_conntrack(struct net *net, struct nf_conn *tmpl,
 910                const struct nf_conntrack_tuple *tuple,
 911                struct nf_conntrack_l3proto *l3proto,
 912                struct nf_conntrack_l4proto *l4proto,
 913                struct sk_buff *skb,
 914                unsigned int dataoff, u32 hash)
 915 {
 916         struct nf_conn *ct;
 917         struct nf_conn_help *help;
 918         struct nf_conntrack_tuple repl_tuple;
 919         struct nf_conntrack_ecache *ecache;
 920         struct nf_conntrack_expect *exp = NULL;
 921         const struct nf_conntrack_zone *zone;
 922         struct nf_conn_timeout *timeout_ext;
 923         struct nf_conntrack_zone tmp;
 924         unsigned int *timeouts;
 925
 926         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 927                 pr_debug("Can't invert tuple.\n");
 928                 return NULL;
 929         }
 930
 931         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
 932         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 933                                   hash);
 934         if (IS_ERR(ct))
 935                 return (struct nf_conntrack_tuple_hash *)ct;
 936
 937         if (tmpl && nfct_synproxy(tmpl)) {
 938                 nfct_seqadj_ext_add(ct);
 939                 nfct_synproxy_ext_add(ct);
 940         }
 941
 942         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
 943         if (timeout_ext) {
 944                 timeouts = nf_ct_timeout_data(timeout_ext);
 945                 if (unlikely(!timeouts))
 946                         timeouts = l4proto->get_timeouts(net);
 947         } else {
 948                 timeouts = l4proto->get_timeouts(net);
 949         }
 950
 951         if (!l4proto->new(ct, skb, dataoff, timeouts)) {
 952                 nf_conntrack_free(ct);
 953                 pr_debug("init conntrack: can't track with proto module\n");
 954                 return NULL;
 955         }
 956
 957         if (timeout_ext)
 958                 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
 959                                       GFP_ATOMIC);
 960
 961         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 962         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
 963         nf_ct_labels_ext_add(ct);
 964
 965         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
 966         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
 967                                  ecache ? ecache->expmask : 0,
 968                              GFP_ATOMIC);
 969
 970         local_bh_disable();
 971         if (net->ct.expect_count) {
 972                 spin_lock(&nf_conntrack_expect_lock);
 973                 exp = nf_ct_find_expectation(net, zone, tuple);
 974                 if (exp) {
 975                         pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 976                                  ct, exp);
 977                         /* Welcome, Mr. Bond.  We've been expecting you... */
 978                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
 979                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
 980                         ct->master = exp->master;
 981                         if (exp->helper) {
 982                                 help = nf_ct_helper_ext_add(ct, exp->helper,
 983                                                             GFP_ATOMIC);
 984                                 if (help)
 985                                         rcu_assign_pointer(help->helper, exp->helper);
 986                         }
 987
 988 #ifdef CONFIG_NF_CONNTRACK_MARK
 989                         ct->mark = exp->master->mark;
 990 #endif
 991 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 992                         ct->secmark = exp->master->secmark;
 993 #endif
 994                         NF_CT_STAT_INC(net, expect_new);
 995                 }
 996                 spin_unlock(&nf_conntrack_expect_lock);
 997         }
 998         if (!exp) {
 999                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1000                 NF_CT_STAT_INC(net, new);
1001         }
1002
1003         /* Now it is inserted into the unconfirmed list, bump refcount */
1004         nf_conntrack_get(&ct->ct_general);
1005         nf_ct_add_to_unconfirmed_list(ct);
1006
1007         local_bh_enable();
1008
1009         if (exp) {
1010                 if (exp->expectfn)
1011                         exp->expectfn(ct, exp);
1012                 nf_ct_expect_put(exp);
1013         }
1014
1015         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1016 }
1017
1018 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1019 static inline struct nf_conn *
1020 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1021                   struct sk_buff *skb,
1022                   unsigned int dataoff,
1023                   u_int16_t l3num,
1024                   u_int8_t protonum,
1025                   struct nf_conntrack_l3proto *l3proto,
1026                   struct nf_conntrack_l4proto *l4proto,
1027                   int *set_reply,
1028                   enum ip_conntrack_info *ctinfo)
1029 {
1030         const struct nf_conntrack_zone *zone;
1031         struct nf_conntrack_tuple tuple;
1032         struct nf_conntrack_tuple_hash *h;
1033         struct nf_conntrack_zone tmp;
1034         struct nf_conn *ct;
1035         u32 hash;
1036
1037         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1038                              dataoff, l3num, protonum, net, &tuple, l3proto,
1039                              l4proto)) {
1040                 pr_debug("resolve_normal_ct: Can't get tuple\n");
1041                 return NULL;
1042         }
1043
1044         /* look for tuple match */
1045         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1046         hash = hash_conntrack_raw(&tuple);
1047         h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1048         if (!h) {
1049                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1050                                    skb, dataoff, hash);
1051                 if (!h)
1052                         return NULL;
1053                 if (IS_ERR(h))
1054                         return (void *)h;
1055         }
1056         ct = nf_ct_tuplehash_to_ctrack(h);
1057
1058         /* It exists; we have (non-exclusive) reference. */
1059         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1060                 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1061                 /* Please set reply bit if this packet OK */
1062                 *set_reply = 1;
1063         } else {
1064                 /* Once we've had two way comms, always ESTABLISHED. */
1065                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1066                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1067                         *ctinfo = IP_CT_ESTABLISHED;
1068                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1069                         pr_debug("nf_conntrack_in: related packet for %p\n",
1070                                  ct);
1071                         *ctinfo = IP_CT_RELATED;
1072                 } else {
1073                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1074                         *ctinfo = IP_CT_NEW;
1075                 }
1076                 *set_reply = 0;
1077         }
1078         skb->nfct = &ct->ct_general;
1079         skb->nfctinfo = *ctinfo;
1080         return ct;
1081 }
1082
1083 unsigned int
1084 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1085                 struct sk_buff *skb)
1086 {
1087         struct nf_conn *ct, *tmpl = NULL;
1088         enum ip_conntrack_info ctinfo;
1089         struct nf_conntrack_l3proto *l3proto;
1090         struct nf_conntrack_l4proto *l4proto;
1091         unsigned int *timeouts;
1092         unsigned int dataoff;
1093         u_int8_t protonum;
1094         int set_reply = 0;
1095         int ret;
1096
1097         if (skb->nfct) {
1098                 /* Previously seen (loopback or untracked)?  Ignore. */
1099                 tmpl = (struct nf_conn *)skb->nfct;
1100                 if (!nf_ct_is_template(tmpl)) {
1101                         NF_CT_STAT_INC_ATOMIC(net, ignore);
1102                         return NF_ACCEPT;
1103                 }
1104                 skb->nfct = NULL;
1105         }
1106
1107         /* rcu_read_lock()ed by nf_hook_slow */
1108         l3proto = __nf_ct_l3proto_find(pf);
1109         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1110                                    &dataoff, &protonum);
1111         if (ret <= 0) {
1112                 pr_debug("not prepared to track yet or error occurred\n");
1113                 NF_CT_STAT_INC_ATOMIC(net, error);
1114                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1115                 ret = -ret;
1116                 goto out;
1117         }
1118
1119         l4proto = __nf_ct_l4proto_find(pf, protonum);
1120
1121         /* It may be an special packet, error, unclean...
1122          * inverse of the return code tells to the netfilter
1123          * core what to do with the packet. */
1124         if (l4proto->error != NULL) {
1125                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1126                                      pf, hooknum);
1127                 if (ret <= 0) {
1128                         NF_CT_STAT_INC_ATOMIC(net, error);
1129                         NF_CT_STAT_INC_ATOMIC(net, invalid);
1130                         ret = -ret;
1131                         goto out;
1132                 }
1133                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1134                 if (skb->nfct)
1135                         goto out;
1136         }
1137
1138         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1139                                l3proto, l4proto, &set_reply, &ctinfo);
1140         if (!ct) {
1141                 /* Not valid part of a connection */
1142                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1143                 ret = NF_ACCEPT;
1144                 goto out;
1145         }
1146
1147         if (IS_ERR(ct)) {
1148                 /* Too stressed to deal. */
1149                 NF_CT_STAT_INC_ATOMIC(net, drop);
1150                 ret = NF_DROP;
1151                 goto out;
1152         }
1153
1154         NF_CT_ASSERT(skb->nfct);
1155
1156         /* Decide what timeout policy we want to apply to this flow. */
1157         timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1158
1159         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1160         if (ret <= 0) {
1161                 /* Invalid: inverse of the return code tells
1162                  * the netfilter core what to do */
1163                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1164                 nf_conntrack_put(skb->nfct);
1165                 skb->nfct = NULL;
1166                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1167                 if (ret == -NF_DROP)
1168                         NF_CT_STAT_INC_ATOMIC(net, drop);
1169                 ret = -ret;
1170                 goto out;
1171         }
1172
1173         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1174                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1175 out:
1176         if (tmpl) {
1177                 /* Special case: we have to repeat this hook, assign the
1178                  * template again to this packet. We assume that this packet
1179                  * has no conntrack assigned. This is used by nf_ct_tcp. */
1180                 if (ret == NF_REPEAT)
1181                         skb->nfct = (struct nf_conntrack *)tmpl;
1182                 else
1183                         nf_ct_put(tmpl);
1184         }
1185
1186         return ret;
1187 }
1188 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1189
1190 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1191                           const struct nf_conntrack_tuple *orig)
1192 {
1193         bool ret;
1194
1195         rcu_read_lock();
1196         ret = nf_ct_invert_tuple(inverse, orig,
1197                                  __nf_ct_l3proto_find(orig->src.l3num),
1198                                  __nf_ct_l4proto_find(orig->src.l3num,
1199                                                       orig->dst.protonum));
1200         rcu_read_unlock();
1201         return ret;
1202 }
1203 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1204
1205 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1206    implicitly racy: see __nf_conntrack_confirm */
1207 void nf_conntrack_alter_reply(struct nf_conn *ct,
1208                               const struct nf_conntrack_tuple *newreply)
1209 {
1210         struct nf_conn_help *help = nfct_help(ct);
1211
1212         /* Should be unconfirmed, so not in hash table yet */
1213         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1214
1215         pr_debug("Altering reply tuple of %p to ", ct);
1216         nf_ct_dump_tuple(newreply);
1217
1218         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1219         if (ct->master || (help && !hlist_empty(&help->expectations)))
1220                 return;
1221
1222         rcu_read_lock();
1223         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1224         rcu_read_unlock();
1225 }
1226 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1227
1228 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1229 void __nf_ct_refresh_acct(struct nf_conn *ct,
1230                           enum ip_conntrack_info ctinfo,
1231                           const struct sk_buff *skb,
1232                           unsigned long extra_jiffies,
1233                           int do_acct)
1234 {
1235         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1236         NF_CT_ASSERT(skb);
1237
1238         /* Only update if this is not a fixed timeout */
1239         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1240                 goto acct;
1241
1242         /* If not in hash table, timer will not be active yet */
1243         if (!nf_ct_is_confirmed(ct)) {
1244                 ct->timeout.expires = extra_jiffies;
1245         } else {
1246                 unsigned long newtime = jiffies + extra_jiffies;
1247
1248                 /* Only update the timeout if the new timeout is at least
1249                    HZ jiffies from the old timeout. Need del_timer for race
1250                    avoidance (may already be dying). */
1251                 if (newtime - ct->timeout.expires >= HZ)
1252                         mod_timer_pending(&ct->timeout, newtime);
1253         }
1254
1255 acct:
1256         if (do_acct) {
1257                 struct nf_conn_acct *acct;
1258
1259                 acct = nf_conn_acct_find(ct);
1260                 if (acct) {
1261                         struct nf_conn_counter *counter = acct->counter;
1262
1263                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1264                         atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1265                 }
1266         }
1267 }
1268 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1269
1270 bool __nf_ct_kill_acct(struct nf_conn *ct,
1271                        enum ip_conntrack_info ctinfo,
1272                        const struct sk_buff *skb,
1273                        int do_acct)
1274 {
1275         if (do_acct) {
1276                 struct nf_conn_acct *acct;
1277
1278                 acct = nf_conn_acct_find(ct);
1279                 if (acct) {
1280                         struct nf_conn_counter *counter = acct->counter;
1281
1282                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1283                         atomic64_add(skb->len - skb_network_offset(skb),
1284                                      &counter[CTINFO2DIR(ctinfo)].bytes);
1285                 }
1286         }
1287
1288         if (del_timer(&ct->timeout)) {
1289                 ct->timeout.function((unsigned long)ct);
1290                 return true;
1291         }
1292         return false;
1293 }
1294 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1295
1296 #ifdef CONFIG_NF_CONNTRACK_ZONES
1297 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1298         .len    = sizeof(struct nf_conntrack_zone),
1299         .align  = __alignof__(struct nf_conntrack_zone),
1300         .id     = NF_CT_EXT_ZONE,
1301 };
1302 #endif
1303
1304 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1305
1306 #include <linux/netfilter/nfnetlink.h>
1307 #include <linux/netfilter/nfnetlink_conntrack.h>
1308 #include <linux/mutex.h>
1309
1310 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1311  * in ip_conntrack_core, since we don't want the protocols to autoload
1312  * or depend on ctnetlink */
1313 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1314                                const struct nf_conntrack_tuple *tuple)
1315 {
1316         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1317             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1318                 goto nla_put_failure;
1319         return 0;
1320
1321 nla_put_failure:
1322         return -1;
1323 }
1324 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1325
1326 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1327         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1328         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1329 };
1330 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1331
1332 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1333                                struct nf_conntrack_tuple *t)
1334 {
1335         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1336                 return -EINVAL;
1337
1338         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1339         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1340
1341         return 0;
1342 }
1343 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1344
1345 int nf_ct_port_nlattr_tuple_size(void)
1346 {
1347         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1348 }
1349 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1350 #endif
1351
1352 /* Used by ipt_REJECT and ip6t_REJECT. */
1353 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1354 {
1355         struct nf_conn *ct;
1356         enum ip_conntrack_info ctinfo;
1357
1358         /* This ICMP is in reverse direction to the packet which caused it */
1359         ct = nf_ct_get(skb, &ctinfo);
1360         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1361                 ctinfo = IP_CT_RELATED_REPLY;
1362         else
1363                 ctinfo = IP_CT_RELATED;
1364
1365         /* Attach to new skbuff, and increment count */
1366         nskb->nfct = &ct->ct_general;
1367         nskb->nfctinfo = ctinfo;
1368         nf_conntrack_get(nskb->nfct);
1369 }
1370
1371 /* Bring out ya dead! */
1372 static struct nf_conn *
1373 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1374                 void *data, unsigned int *bucket)
1375 {
1376         struct nf_conntrack_tuple_hash *h;
1377         struct nf_conn *ct;
1378         struct hlist_nulls_node *n;
1379         int cpu;
1380         spinlock_t *lockp;
1381
1382         for (; *bucket < net->ct.htable_size; (*bucket)++) {
1383                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1384                 local_bh_disable();
1385                 spin_lock(lockp);
1386                 if (*bucket < net->ct.htable_size) {
1387                         hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1388                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1389                                         continue;
1390                                 ct = nf_ct_tuplehash_to_ctrack(h);
1391                                 if (iter(ct, data))
1392                                         goto found;
1393                         }
1394                 }
1395                 spin_unlock(lockp);
1396                 local_bh_enable();
1397         }
1398
1399         for_each_possible_cpu(cpu) {
1400                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1401
1402                 spin_lock_bh(&pcpu->lock);
1403                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1404                         ct = nf_ct_tuplehash_to_ctrack(h);
1405                         if (iter(ct, data))
1406                                 set_bit(IPS_DYING_BIT, &ct->status);
1407                 }
1408                 spin_unlock_bh(&pcpu->lock);
1409         }
1410         return NULL;
1411 found:
1412         atomic_inc(&ct->ct_general.use);
1413         spin_unlock(lockp);
1414         local_bh_enable();
1415         return ct;
1416 }
1417
1418 void nf_ct_iterate_cleanup(struct net *net,
1419                            int (*iter)(struct nf_conn *i, void *data),
1420                            void *data, u32 portid, int report)
1421 {
1422         struct nf_conn *ct;
1423         unsigned int bucket = 0;
1424
1425         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1426                 /* Time to push up daises... */
1427                 if (del_timer(&ct->timeout))
1428                         nf_ct_delete(ct, portid, report);
1429
1430                 /* ... else the timer will get him soon. */
1431
1432                 nf_ct_put(ct);
1433         }
1434 }
1435 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1436
1437 static int kill_all(struct nf_conn *i, void *data)
1438 {
1439         return 1;
1440 }
1441
1442 void nf_ct_free_hashtable(void *hash, unsigned int size)
1443 {
1444         if (is_vmalloc_addr(hash))
1445                 vfree(hash);
1446         else
1447                 free_pages((unsigned long)hash,
1448                            get_order(sizeof(struct hlist_head) * size));
1449 }
1450 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1451
1452 static int untrack_refs(void)
1453 {
1454         int cnt = 0, cpu;
1455
1456         for_each_possible_cpu(cpu) {
1457                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1458
1459                 cnt += atomic_read(&ct->ct_general.use) - 1;
1460         }
1461         return cnt;
1462 }
1463
1464 void nf_conntrack_cleanup_start(void)
1465 {
1466         RCU_INIT_POINTER(ip_ct_attach, NULL);
1467 }
1468
1469 void nf_conntrack_cleanup_end(void)
1470 {
1471         RCU_INIT_POINTER(nf_ct_destroy, NULL);
1472         while (untrack_refs() > 0)
1473                 schedule();
1474
1475 #ifdef CONFIG_NF_CONNTRACK_ZONES
1476         nf_ct_extend_unregister(&nf_ct_zone_extend);
1477 #endif
1478         nf_conntrack_proto_fini();
1479         nf_conntrack_seqadj_fini();
1480         nf_conntrack_labels_fini();
1481         nf_conntrack_helper_fini();
1482         nf_conntrack_timeout_fini();
1483         nf_conntrack_ecache_fini();
1484         nf_conntrack_tstamp_fini();
1485         nf_conntrack_acct_fini();
1486         nf_conntrack_expect_fini();
1487 }
1488
1489 /*
1490  * Mishearing the voices in his head, our hero wonders how he's
1491  * supposed to kill the mall.
1492  */
1493 void nf_conntrack_cleanup_net(struct net *net)
1494 {
1495         LIST_HEAD(single);
1496
1497         list_add(&net->exit_list, &single);
1498         nf_conntrack_cleanup_net_list(&single);
1499 }
1500
1501 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1502 {
1503         int busy;
1504         struct net *net;
1505
1506         /*
1507          * This makes sure all current packets have passed through
1508          *  netfilter framework.  Roll on, two-stage module
1509          *  delete...
1510          */
1511         synchronize_net();
1512 i_see_dead_people:
1513         busy = 0;
1514         list_for_each_entry(net, net_exit_list, exit_list) {
1515                 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1516                 if (atomic_read(&net->ct.count) != 0)
1517                         busy = 1;
1518         }
1519         if (busy) {
1520                 schedule();
1521                 goto i_see_dead_people;
1522         }
1523
1524         list_for_each_entry(net, net_exit_list, exit_list) {
1525                 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1526                 nf_conntrack_proto_pernet_fini(net);
1527                 nf_conntrack_helper_pernet_fini(net);
1528                 nf_conntrack_ecache_pernet_fini(net);
1529                 nf_conntrack_tstamp_pernet_fini(net);
1530                 nf_conntrack_acct_pernet_fini(net);
1531                 nf_conntrack_expect_pernet_fini(net);
1532                 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1533                 kfree(net->ct.slabname);
1534                 free_percpu(net->ct.stat);
1535                 free_percpu(net->ct.pcpu_lists);
1536         }
1537 }
1538
1539 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1540 {
1541         struct hlist_nulls_head *hash;
1542         unsigned int nr_slots, i;
1543         size_t sz;
1544
1545         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1546         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1547         sz = nr_slots * sizeof(struct hlist_nulls_head);
1548         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1549                                         get_order(sz));
1550         if (!hash)
1551                 hash = vzalloc(sz);
1552
1553         if (hash && nulls)
1554                 for (i = 0; i < nr_slots; i++)
1555                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1556
1557         return hash;
1558 }
1559 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1560
1561 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1562 {
1563         int i, bucket, rc;
1564         unsigned int hashsize, old_size;
1565         struct hlist_nulls_head *hash, *old_hash;
1566         struct nf_conntrack_tuple_hash *h;
1567         struct nf_conn *ct;
1568
1569         if (current->nsproxy->net_ns != &init_net)
1570                 return -EOPNOTSUPP;
1571
1572         /* On boot, we can set this without any fancy locking. */
1573         if (!nf_conntrack_htable_size)
1574                 return param_set_uint(val, kp);
1575
1576         rc = kstrtouint(val, 0, &hashsize);
1577         if (rc)
1578                 return rc;
1579         if (!hashsize)
1580                 return -EINVAL;
1581
1582         hash = nf_ct_alloc_hashtable(&hashsize, 1);
1583         if (!hash)
1584                 return -ENOMEM;
1585
1586         local_bh_disable();
1587         nf_conntrack_all_lock();
1588         write_seqcount_begin(&init_net.ct.generation);
1589
1590         /* Lookups in the old hash might happen in parallel, which means we
1591          * might get false negatives during connection lookup. New connections
1592          * created because of a false negative won't make it into the hash
1593          * though since that required taking the locks.
1594          */
1595
1596         for (i = 0; i < init_net.ct.htable_size; i++) {
1597                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1598                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1599                                         struct nf_conntrack_tuple_hash, hnnode);
1600                         ct = nf_ct_tuplehash_to_ctrack(h);
1601                         hlist_nulls_del_rcu(&h->hnnode);
1602                         bucket = __hash_conntrack(&h->tuple, hashsize);
1603                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1604                 }
1605         }
1606         old_size = init_net.ct.htable_size;
1607         old_hash = init_net.ct.hash;
1608
1609         init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1610         init_net.ct.hash = hash;
1611
1612         write_seqcount_end(&init_net.ct.generation);
1613         nf_conntrack_all_unlock();
1614         local_bh_enable();
1615
1616         nf_ct_free_hashtable(old_hash, old_size);
1617         return 0;
1618 }
1619 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1620
1621 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1622                   &nf_conntrack_htable_size, 0600);
1623
1624 void nf_ct_untracked_status_or(unsigned long bits)
1625 {
1626         int cpu;
1627
1628         for_each_possible_cpu(cpu)
1629                 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1630 }
1631 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1632
1633 int nf_conntrack_init_start(void)
1634 {
1635         int max_factor = 8;
1636         int i, ret, cpu;
1637
1638         for (i = 0; i < CONNTRACK_LOCKS; i++)
1639                 spin_lock_init(&nf_conntrack_locks[i]);
1640
1641         if (!nf_conntrack_htable_size) {
1642                 /* Idea from tcp.c: use 1/16384 of memory.
1643                  * On i386: 32MB machine has 512 buckets.
1644                  * >= 1GB machines have 16384 buckets.
1645                  * >= 4GB machines have 65536 buckets.
1646                  */
1647                 nf_conntrack_htable_size
1648                         = (((totalram_pages << PAGE_SHIFT) / 16384)
1649                            / sizeof(struct hlist_head));
1650                 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1651                         nf_conntrack_htable_size = 65536;
1652                 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1653                         nf_conntrack_htable_size = 16384;
1654                 if (nf_conntrack_htable_size < 32)
1655                         nf_conntrack_htable_size = 32;
1656
1657                 /* Use a max. factor of four by default to get the same max as
1658                  * with the old struct list_heads. When a table size is given
1659                  * we use the old value of 8 to avoid reducing the max.
1660                  * entries. */
1661                 max_factor = 4;
1662         }
1663         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1664
1665         printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1666                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1667                nf_conntrack_max);
1668
1669         ret = nf_conntrack_expect_init();
1670         if (ret < 0)
1671                 goto err_expect;
1672
1673         ret = nf_conntrack_acct_init();
1674         if (ret < 0)
1675                 goto err_acct;
1676
1677         ret = nf_conntrack_tstamp_init();
1678         if (ret < 0)
1679                 goto err_tstamp;
1680
1681         ret = nf_conntrack_ecache_init();
1682         if (ret < 0)
1683                 goto err_ecache;
1684
1685         ret = nf_conntrack_timeout_init();
1686         if (ret < 0)
1687                 goto err_timeout;
1688
1689         ret = nf_conntrack_helper_init();
1690         if (ret < 0)
1691                 goto err_helper;
1692
1693         ret = nf_conntrack_labels_init();
1694         if (ret < 0)
1695                 goto err_labels;
1696
1697         ret = nf_conntrack_seqadj_init();
1698         if (ret < 0)
1699                 goto err_seqadj;
1700
1701 #ifdef CONFIG_NF_CONNTRACK_ZONES
1702         ret = nf_ct_extend_register(&nf_ct_zone_extend);
1703         if (ret < 0)
1704                 goto err_extend;
1705 #endif
1706         ret = nf_conntrack_proto_init();
1707         if (ret < 0)
1708                 goto err_proto;
1709
1710         /* Set up fake conntrack: to never be deleted, not in any hashes */
1711         for_each_possible_cpu(cpu) {
1712                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1713                 write_pnet(&ct->ct_net, &init_net);
1714                 atomic_set(&ct->ct_general.use, 1);
1715         }
1716         /*  - and look it like as a confirmed connection */
1717         nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1718         return 0;
1719
1720 err_proto:
1721 #ifdef CONFIG_NF_CONNTRACK_ZONES
1722         nf_ct_extend_unregister(&nf_ct_zone_extend);
1723 err_extend:
1724 #endif
1725         nf_conntrack_seqadj_fini();
1726 err_seqadj:
1727         nf_conntrack_labels_fini();
1728 err_labels:
1729         nf_conntrack_helper_fini();
1730 err_helper:
1731         nf_conntrack_timeout_fini();
1732 err_timeout:
1733         nf_conntrack_ecache_fini();
1734 err_ecache:
1735         nf_conntrack_tstamp_fini();
1736 err_tstamp:
1737         nf_conntrack_acct_fini();
1738 err_acct:
1739         nf_conntrack_expect_fini();
1740 err_expect:
1741         return ret;
1742 }
1743
1744 void nf_conntrack_init_end(void)
1745 {
1746         /* For use by REJECT target */
1747         RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1748         RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1749 }
1750
1751 /*
1752  * We need to use special "null" values, not used in hash table
1753  */
1754 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
1755 #define DYING_NULLS_VAL         ((1<<30)+1)
1756 #define TEMPLATE_NULLS_VAL      ((1<<30)+2)
1757
1758 int nf_conntrack_init_net(struct net *net)
1759 {
1760         int ret = -ENOMEM;
1761         int cpu;
1762
1763         atomic_set(&net->ct.count, 0);
1764         seqcount_init(&net->ct.generation);
1765
1766         net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1767         if (!net->ct.pcpu_lists)
1768                 goto err_stat;
1769
1770         for_each_possible_cpu(cpu) {
1771                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1772
1773                 spin_lock_init(&pcpu->lock);
1774                 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1775                 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1776         }
1777
1778         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1779         if (!net->ct.stat)
1780                 goto err_pcpu_lists;
1781
1782         net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1783         if (!net->ct.slabname)
1784                 goto err_slabname;
1785
1786         net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1787                                                         sizeof(struct nf_conn), 0,
1788                                                         SLAB_DESTROY_BY_RCU, NULL);
1789         if (!net->ct.nf_conntrack_cachep) {
1790                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1791                 goto err_cache;
1792         }
1793
1794         net->ct.htable_size = nf_conntrack_htable_size;
1795         net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1796         if (!net->ct.hash) {
1797                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1798                 goto err_hash;
1799         }
1800         ret = nf_conntrack_expect_pernet_init(net);
1801         if (ret < 0)
1802                 goto err_expect;
1803         ret = nf_conntrack_acct_pernet_init(net);
1804         if (ret < 0)
1805                 goto err_acct;
1806         ret = nf_conntrack_tstamp_pernet_init(net);
1807         if (ret < 0)
1808                 goto err_tstamp;
1809         ret = nf_conntrack_ecache_pernet_init(net);
1810         if (ret < 0)
1811                 goto err_ecache;
1812         ret = nf_conntrack_helper_pernet_init(net);
1813         if (ret < 0)
1814                 goto err_helper;
1815         ret = nf_conntrack_proto_pernet_init(net);
1816         if (ret < 0)
1817                 goto err_proto;
1818         return 0;
1819
1820 err_proto:
1821         nf_conntrack_helper_pernet_fini(net);
1822 err_helper:
1823         nf_conntrack_ecache_pernet_fini(net);
1824 err_ecache:
1825         nf_conntrack_tstamp_pernet_fini(net);
1826 err_tstamp:
1827         nf_conntrack_acct_pernet_fini(net);
1828 err_acct:
1829         nf_conntrack_expect_pernet_fini(net);
1830 err_expect:
1831         nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1832 err_hash:
1833         kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1834 err_cache:
1835         kfree(net->ct.slabname);
1836 err_slabname:
1837         free_percpu(net->ct.stat);
1838 err_pcpu_lists:
1839         free_percpu(net->ct.pcpu_lists);
1840 err_stat:
1841         return ret;
1842 }