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 __read_mostly spinlock_t nf_conntrack_locks_all_lock;
  70 static __read_mostly bool nf_conntrack_locks_all;
  71
  72 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
  73 {
  74         spin_lock(lock);
  75         while (unlikely(nf_conntrack_locks_all)) {
  76                 spin_unlock(lock);
  77                 spin_lock(&nf_conntrack_locks_all_lock);
  78                 spin_unlock(&nf_conntrack_locks_all_lock);
  79                 spin_lock(lock);
  80         }
  81 }
  82 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
  83
  84 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
  85 {
  86         h1 %= CONNTRACK_LOCKS;
  87         h2 %= CONNTRACK_LOCKS;
  88         spin_unlock(&nf_conntrack_locks[h1]);
  89         if (h1 != h2)
  90                 spin_unlock(&nf_conntrack_locks[h2]);
  91 }
  92
  93 /* return true if we need to recompute hashes (in case hash table was resized) */
  94 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
  95                                      unsigned int h2, unsigned int sequence)
  96 {
  97         h1 %= CONNTRACK_LOCKS;
  98         h2 %= CONNTRACK_LOCKS;
  99         if (h1 <= h2) {
 100                 nf_conntrack_lock(&nf_conntrack_locks[h1]);
 101                 if (h1 != h2)
 102                         spin_lock_nested(&nf_conntrack_locks[h2],
 103                                          SINGLE_DEPTH_NESTING);
 104         } else {
 105                 nf_conntrack_lock(&nf_conntrack_locks[h2]);
 106                 spin_lock_nested(&nf_conntrack_locks[h1],
 107                                  SINGLE_DEPTH_NESTING);
 108         }
 109         if (read_seqcount_retry(&net->ct.generation, sequence)) {
 110                 nf_conntrack_double_unlock(h1, h2);
 111                 return true;
 112         }
 113         return false;
 114 }
 115
 116 static void nf_conntrack_all_lock(void)
 117 {
 118         int i;
 119
 120         spin_lock(&nf_conntrack_locks_all_lock);
 121         nf_conntrack_locks_all = true;
 122
 123         for (i = 0; i < CONNTRACK_LOCKS; i++) {
 124                 spin_lock(&nf_conntrack_locks[i]);
 125                 spin_unlock(&nf_conntrack_locks[i]);
 126         }
 127 }
 128
 129 static void nf_conntrack_all_unlock(void)
 130 {
 131         nf_conntrack_locks_all = false;
 132         spin_unlock(&nf_conntrack_locks_all_lock);
 133 }
 134
 135 unsigned int nf_conntrack_htable_size __read_mostly;
 136 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
 137
 138 unsigned int nf_conntrack_max __read_mostly;
 139 EXPORT_SYMBOL_GPL(nf_conntrack_max);
 140
 141 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 142 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
 143
 144 unsigned int nf_conntrack_hash_rnd __read_mostly;
 145 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
 146
 147 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple)
 148 {
 149         unsigned int n;
 150
 151         /* The direction must be ignored, so we hash everything up to the
 152          * destination ports (which is a multiple of 4) and treat the last
 153          * three bytes manually.
 154          */
 155         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
 156         return jhash2((u32 *)tuple, n, nf_conntrack_hash_rnd ^
 157                       (((__force __u16)tuple->dst.u.all << 16) |
 158                       tuple->dst.protonum));
 159 }
 160
 161 static u32 __hash_bucket(u32 hash, unsigned int size)
 162 {
 163         return reciprocal_scale(hash, size);
 164 }
 165
 166 static u32 hash_bucket(u32 hash, const struct net *net)
 167 {
 168         return __hash_bucket(hash, net->ct.htable_size);
 169 }
 170
 171 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
 172                                   unsigned int size)
 173 {
 174         return __hash_bucket(hash_conntrack_raw(tuple), size);
 175 }
 176
 177 static inline u_int32_t hash_conntrack(const struct net *net,
 178                                        const struct nf_conntrack_tuple *tuple)
 179 {
 180         return __hash_conntrack(tuple, net->ct.htable_size);
 181 }
 182
 183 bool
 184 nf_ct_get_tuple(const struct sk_buff *skb,
 185                 unsigned int nhoff,
 186                 unsigned int dataoff,
 187                 u_int16_t l3num,
 188                 u_int8_t protonum,
 189                 struct net *net,
 190                 struct nf_conntrack_tuple *tuple,
 191                 const struct nf_conntrack_l3proto *l3proto,
 192                 const struct nf_conntrack_l4proto *l4proto)
 193 {
 194         memset(tuple, 0, sizeof(*tuple));
 195
 196         tuple->src.l3num = l3num;
 197         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 198                 return false;
 199
 200         tuple->dst.protonum = protonum;
 201         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 202
 203         return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
 204 }
 205 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 206
 207 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 208                        u_int16_t l3num,
 209                        struct net *net, struct nf_conntrack_tuple *tuple)
 210 {
 211         struct nf_conntrack_l3proto *l3proto;
 212         struct nf_conntrack_l4proto *l4proto;
 213         unsigned int protoff;
 214         u_int8_t protonum;
 215         int ret;
 216
 217         rcu_read_lock();
 218
 219         l3proto = __nf_ct_l3proto_find(l3num);
 220         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 221         if (ret != NF_ACCEPT) {
 222                 rcu_read_unlock();
 223                 return false;
 224         }
 225
 226         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 227
 228         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
 229                               l3proto, l4proto);
 230
 231         rcu_read_unlock();
 232         return ret;
 233 }
 234 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 235
 236 bool
 237 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 238                    const struct nf_conntrack_tuple *orig,
 239                    const struct nf_conntrack_l3proto *l3proto,
 240                    const struct nf_conntrack_l4proto *l4proto)
 241 {
 242         memset(inverse, 0, sizeof(*inverse));
 243
 244         inverse->src.l3num = orig->src.l3num;
 245         if (l3proto->invert_tuple(inverse, orig) == 0)
 246                 return false;
 247
 248         inverse->dst.dir = !orig->dst.dir;
 249
 250         inverse->dst.protonum = orig->dst.protonum;
 251         return l4proto->invert_tuple(inverse, orig);
 252 }
 253 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 254
 255 static void
 256 clean_from_lists(struct nf_conn *ct)
 257 {
 258         pr_debug("clean_from_lists(%p)\n", ct);
 259         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 260         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 261
 262         /* Destroy all pending expectations */
 263         nf_ct_remove_expectations(ct);
 264 }
 265
 266 /* must be called with local_bh_disable */
 267 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
 268 {
 269         struct ct_pcpu *pcpu;
 270
 271         /* add this conntrack to the (per cpu) dying list */
 272         ct->cpu = smp_processor_id();
 273         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 274
 275         spin_lock(&pcpu->lock);
 276         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 277                              &pcpu->dying);
 278         spin_unlock(&pcpu->lock);
 279 }
 280
 281 /* must be called with local_bh_disable */
 282 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
 283 {
 284         struct ct_pcpu *pcpu;
 285
 286         /* add this conntrack to the (per cpu) unconfirmed list */
 287         ct->cpu = smp_processor_id();
 288         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 289
 290         spin_lock(&pcpu->lock);
 291         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 292                              &pcpu->unconfirmed);
 293         spin_unlock(&pcpu->lock);
 294 }
 295
 296 /* must be called with local_bh_disable */
 297 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
 298 {
 299         struct ct_pcpu *pcpu;
 300
 301         /* We overload first tuple to link into unconfirmed or dying list.*/
 302         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 303
 304         spin_lock(&pcpu->lock);
 305         BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 306         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 307         spin_unlock(&pcpu->lock);
 308 }
 309
 310 /* Released via destroy_conntrack() */
 311 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
 312                                  const struct nf_conntrack_zone *zone,
 313                                  gfp_t flags)
 314 {
 315         struct nf_conn *tmpl;
 316
 317         tmpl = kzalloc(sizeof(*tmpl), flags);
 318         if (tmpl == NULL)
 319                 return NULL;
 320
 321         tmpl->status = IPS_TEMPLATE;
 322         write_pnet(&tmpl->ct_net, net);
 323
 324         if (nf_ct_zone_add(tmpl, flags, zone) < 0)
 325                 goto out_free;
 326
 327         atomic_set(&tmpl->ct_general.use, 0);
 328
 329         return tmpl;
 330 out_free:
 331         kfree(tmpl);
 332         return NULL;
 333 }
 334 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
 335
 336 void nf_ct_tmpl_free(struct nf_conn *tmpl)
 337 {
 338         nf_ct_ext_destroy(tmpl);
 339         nf_ct_ext_free(tmpl);
 340         kfree(tmpl);
 341 }
 342 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
 343
 344 static void
 345 destroy_conntrack(struct nf_conntrack *nfct)
 346 {
 347         struct nf_conn *ct = (struct nf_conn *)nfct;
 348         struct net *net = nf_ct_net(ct);
 349         struct nf_conntrack_l4proto *l4proto;
 350
 351         pr_debug("destroy_conntrack(%p)\n", ct);
 352         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 353         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 354
 355         if (unlikely(nf_ct_is_template(ct))) {
 356                 nf_ct_tmpl_free(ct);
 357                 return;
 358         }
 359         rcu_read_lock();
 360         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 361         if (l4proto && l4proto->destroy)
 362                 l4proto->destroy(ct);
 363
 364         rcu_read_unlock();
 365
 366         local_bh_disable();
 367         /* Expectations will have been removed in clean_from_lists,
 368          * except TFTP can create an expectation on the first packet,
 369          * before connection is in the list, so we need to clean here,
 370          * too.
 371          */
 372         nf_ct_remove_expectations(ct);
 373
 374         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 375
 376         NF_CT_STAT_INC(net, delete);
 377         local_bh_enable();
 378
 379         if (ct->master)
 380                 nf_ct_put(ct->master);
 381
 382         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 383         nf_conntrack_free(ct);
 384 }
 385
 386 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 387 {
 388         struct net *net = nf_ct_net(ct);
 389         unsigned int hash, reply_hash;
 390         unsigned int sequence;
 391
 392         nf_ct_helper_destroy(ct);
 393
 394         local_bh_disable();
 395         do {
 396                 sequence = read_seqcount_begin(&net->ct.generation);
 397                 hash = hash_conntrack(net,
 398                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 399                 reply_hash = hash_conntrack(net,
 400                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 401         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 402
 403         clean_from_lists(ct);
 404         nf_conntrack_double_unlock(hash, reply_hash);
 405
 406         nf_ct_add_to_dying_list(ct);
 407
 408         NF_CT_STAT_INC(net, delete_list);
 409         local_bh_enable();
 410 }
 411
 412 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 413 {
 414         struct nf_conn_tstamp *tstamp;
 415
 416         tstamp = nf_conn_tstamp_find(ct);
 417         if (tstamp && tstamp->stop == 0)
 418                 tstamp->stop = ktime_get_real_ns();
 419
 420         if (nf_ct_is_dying(ct))
 421                 goto delete;
 422
 423         if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 424                                     portid, report) < 0) {
 425                 /* destroy event was not delivered */
 426                 nf_ct_delete_from_lists(ct);
 427                 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
 428                 return false;
 429         }
 430
 431         nf_conntrack_ecache_work(nf_ct_net(ct));
 432         set_bit(IPS_DYING_BIT, &ct->status);
 433  delete:
 434         nf_ct_delete_from_lists(ct);
 435         nf_ct_put(ct);
 436         return true;
 437 }
 438 EXPORT_SYMBOL_GPL(nf_ct_delete);
 439
 440 static void death_by_timeout(unsigned long ul_conntrack)
 441 {
 442         nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
 443 }
 444
 445 static inline bool
 446 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 447                 const struct nf_conntrack_tuple *tuple,
 448                 const struct nf_conntrack_zone *zone)
 449 {
 450         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 451
 452         /* A conntrack can be recreated with the equal tuple,
 453          * so we need to check that the conntrack is confirmed
 454          */
 455         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 456                nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
 457                nf_ct_is_confirmed(ct);
 458 }
 459
 460 /*
 461  * Warning :
 462  * - Caller must take a reference on returned object
 463  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 464  */
 465 static struct nf_conntrack_tuple_hash *
 466 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
 467                       const struct nf_conntrack_tuple *tuple, u32 hash)
 468 {
 469         struct nf_conntrack_tuple_hash *h;
 470         struct hlist_nulls_node *n;
 471         unsigned int bucket = hash_bucket(hash, net);
 472
 473         /* Disable BHs the entire time since we normally need to disable them
 474          * at least once for the stats anyway.
 475          */
 476         local_bh_disable();
 477 begin:
 478         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
 479                 if (nf_ct_key_equal(h, tuple, zone)) {
 480                         NF_CT_STAT_INC(net, found);
 481                         local_bh_enable();
 482                         return h;
 483                 }
 484                 NF_CT_STAT_INC(net, searched);
 485         }
 486         /*
 487          * if the nulls value we got at the end of this lookup is
 488          * not the expected one, we must restart lookup.
 489          * We probably met an item that was moved to another chain.
 490          */
 491         if (get_nulls_value(n) != bucket) {
 492                 NF_CT_STAT_INC(net, search_restart);
 493                 goto begin;
 494         }
 495         local_bh_enable();
 496
 497         return NULL;
 498 }
 499
 500 /* Find a connection corresponding to a tuple. */
 501 static struct nf_conntrack_tuple_hash *
 502 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 503                         const struct nf_conntrack_tuple *tuple, u32 hash)
 504 {
 505         struct nf_conntrack_tuple_hash *h;
 506         struct nf_conn *ct;
 507
 508         rcu_read_lock();
 509 begin:
 510         h = ____nf_conntrack_find(net, zone, tuple, hash);
 511         if (h) {
 512                 ct = nf_ct_tuplehash_to_ctrack(h);
 513                 if (unlikely(nf_ct_is_dying(ct) ||
 514                              !atomic_inc_not_zero(&ct->ct_general.use)))
 515                         h = NULL;
 516                 else {
 517                         if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
 518                                 nf_ct_put(ct);
 519                                 goto begin;
 520                         }
 521                 }
 522         }
 523         rcu_read_unlock();
 524
 525         return h;
 526 }
 527
 528 struct nf_conntrack_tuple_hash *
 529 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 530                       const struct nf_conntrack_tuple *tuple)
 531 {
 532         return __nf_conntrack_find_get(net, zone, tuple,
 533                                        hash_conntrack_raw(tuple));
 534 }
 535 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 536
 537 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 538                                        unsigned int hash,
 539                                        unsigned int reply_hash)
 540 {
 541         struct net *net = nf_ct_net(ct);
 542
 543         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 544                            &net->ct.hash[hash]);
 545         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 546                            &net->ct.hash[reply_hash]);
 547 }
 548
 549 int
 550 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 551 {
 552         const struct nf_conntrack_zone *zone;
 553         struct net *net = nf_ct_net(ct);
 554         unsigned int hash, reply_hash;
 555         struct nf_conntrack_tuple_hash *h;
 556         struct hlist_nulls_node *n;
 557         unsigned int sequence;
 558
 559         zone = nf_ct_zone(ct);
 560
 561         local_bh_disable();
 562         do {
 563                 sequence = read_seqcount_begin(&net->ct.generation);
 564                 hash = hash_conntrack(net,
 565                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 566                 reply_hash = hash_conntrack(net,
 567                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 568         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 569
 570         /* See if there's one in the list already, including reverse */
 571         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 572                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 573                                       &h->tuple) &&
 574                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 575                                      NF_CT_DIRECTION(h)))
 576                         goto out;
 577         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 578                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 579                                       &h->tuple) &&
 580                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 581                                      NF_CT_DIRECTION(h)))
 582                         goto out;
 583
 584         add_timer(&ct->timeout);
 585         smp_wmb();
 586         /* The caller holds a reference to this object */
 587         atomic_set(&ct->ct_general.use, 2);
 588         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 589         nf_conntrack_double_unlock(hash, reply_hash);
 590         NF_CT_STAT_INC(net, insert);
 591         local_bh_enable();
 592         return 0;
 593
 594 out:
 595         nf_conntrack_double_unlock(hash, reply_hash);
 596         NF_CT_STAT_INC(net, insert_failed);
 597         local_bh_enable();
 598         return -EEXIST;
 599 }
 600 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 601
 602 /* Confirm a connection given skb; places it in hash table */
 603 int
 604 __nf_conntrack_confirm(struct sk_buff *skb)
 605 {
 606         const struct nf_conntrack_zone *zone;
 607         unsigned int hash, reply_hash;
 608         struct nf_conntrack_tuple_hash *h;
 609         struct nf_conn *ct;
 610         struct nf_conn_help *help;
 611         struct nf_conn_tstamp *tstamp;
 612         struct hlist_nulls_node *n;
 613         enum ip_conntrack_info ctinfo;
 614         struct net *net;
 615         unsigned int sequence;
 616
 617         ct = nf_ct_get(skb, &ctinfo);
 618         net = nf_ct_net(ct);
 619
 620         /* ipt_REJECT uses nf_conntrack_attach to attach related
 621            ICMP/TCP RST packets in other direction.  Actual packet
 622            which created connection will be IP_CT_NEW or for an
 623            expected connection, IP_CT_RELATED. */
 624         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 625                 return NF_ACCEPT;
 626
 627         zone = nf_ct_zone(ct);
 628         local_bh_disable();
 629
 630         do {
 631                 sequence = read_seqcount_begin(&net->ct.generation);
 632                 /* reuse the hash saved before */
 633                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 634                 hash = hash_bucket(hash, net);
 635                 reply_hash = hash_conntrack(net,
 636                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 637
 638         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 639
 640         /* We're not in hash table, and we refuse to set up related
 641          * connections for unconfirmed conns.  But packet copies and
 642          * REJECT will give spurious warnings here.
 643          */
 644         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 645
 646         /* No external references means no one else could have
 647          * confirmed us.
 648          */
 649         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 650         pr_debug("Confirming conntrack %p\n", ct);
 651         /* We have to check the DYING flag after unlink to prevent
 652          * a race against nf_ct_get_next_corpse() possibly called from
 653          * user context, else we insert an already 'dead' hash, blocking
 654          * further use of that particular connection -JM.
 655          */
 656         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 657
 658         if (unlikely(nf_ct_is_dying(ct)))
 659                 goto out;
 660
 661         /* See if there's one in the list already, including reverse:
 662            NAT could have grabbed it without realizing, since we're
 663            not in the hash.  If there is, we lost race. */
 664         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 665                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 666                                       &h->tuple) &&
 667                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 668                                      NF_CT_DIRECTION(h)))
 669                         goto out;
 670         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 671                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 672                                       &h->tuple) &&
 673                     nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
 674                                      NF_CT_DIRECTION(h)))
 675                         goto out;
 676
 677         /* Timer relative to confirmation time, not original
 678            setting time, otherwise we'd get timer wrap in
 679            weird delay cases. */
 680         ct->timeout.expires += jiffies;
 681         add_timer(&ct->timeout);
 682         atomic_inc(&ct->ct_general.use);
 683         ct->status |= IPS_CONFIRMED;
 684
 685         /* set conntrack timestamp, if enabled. */
 686         tstamp = nf_conn_tstamp_find(ct);
 687         if (tstamp) {
 688                 if (skb->tstamp.tv64 == 0)
 689                         __net_timestamp(skb);
 690
 691                 tstamp->start = ktime_to_ns(skb->tstamp);
 692         }
 693         /* Since the lookup is lockless, hash insertion must be done after
 694          * starting the timer and setting the CONFIRMED bit. The RCU barriers
 695          * guarantee that no other CPU can find the conntrack before the above
 696          * stores are visible.
 697          */
 698         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 699         nf_conntrack_double_unlock(hash, reply_hash);
 700         NF_CT_STAT_INC(net, insert);
 701         local_bh_enable();
 702
 703         help = nfct_help(ct);
 704         if (help && help->helper)
 705                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 706
 707         nf_conntrack_event_cache(master_ct(ct) ?
 708                                  IPCT_RELATED : IPCT_NEW, ct);
 709         return NF_ACCEPT;
 710
 711 out:
 712         nf_ct_add_to_dying_list(ct);
 713         nf_conntrack_double_unlock(hash, reply_hash);
 714         NF_CT_STAT_INC(net, insert_failed);
 715         local_bh_enable();
 716         return NF_DROP;
 717 }
 718 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 719
 720 /* Returns true if a connection correspondings to the tuple (required
 721    for NAT). */
 722 int
 723 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 724                          const struct nf_conn *ignored_conntrack)
 725 {
 726         struct net *net = nf_ct_net(ignored_conntrack);
 727         const struct nf_conntrack_zone *zone;
 728         struct nf_conntrack_tuple_hash *h;
 729         struct hlist_nulls_node *n;
 730         struct nf_conn *ct;
 731         unsigned int hash;
 732
 733         zone = nf_ct_zone(ignored_conntrack);
 734         hash = hash_conntrack(net, tuple);
 735
 736         /* Disable BHs the entire time since we need to disable them at
 737          * least once for the stats anyway.
 738          */
 739         rcu_read_lock_bh();
 740         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 741                 ct = nf_ct_tuplehash_to_ctrack(h);
 742                 if (ct != ignored_conntrack &&
 743                     nf_ct_tuple_equal(tuple, &h->tuple) &&
 744                     nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
 745                         NF_CT_STAT_INC(net, found);
 746                         rcu_read_unlock_bh();
 747                         return 1;
 748                 }
 749                 NF_CT_STAT_INC(net, searched);
 750         }
 751         rcu_read_unlock_bh();
 752
 753         return 0;
 754 }
 755 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 756
 757 #define NF_CT_EVICTION_RANGE    8
 758
 759 /* There's a small race here where we may free a just-assured
 760    connection.  Too bad: we're in trouble anyway. */
 761 static noinline int early_drop(struct net *net, unsigned int _hash)
 762 {
 763         /* Use oldest entry, which is roughly LRU */
 764         struct nf_conntrack_tuple_hash *h;
 765         struct nf_conn *ct = NULL, *tmp;
 766         struct hlist_nulls_node *n;
 767         unsigned int i = 0, cnt = 0;
 768         int dropped = 0;
 769         unsigned int hash, sequence;
 770         spinlock_t *lockp;
 771
 772         local_bh_disable();
 773 restart:
 774         sequence = read_seqcount_begin(&net->ct.generation);
 775         hash = hash_bucket(_hash, net);
 776         for (; i < net->ct.htable_size; i++) {
 777                 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
 778                 nf_conntrack_lock(lockp);
 779                 if (read_seqcount_retry(&net->ct.generation, sequence)) {
 780                         spin_unlock(lockp);
 781                         goto restart;
 782                 }
 783                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 784                                          hnnode) {
 785                         tmp = nf_ct_tuplehash_to_ctrack(h);
 786                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
 787                             !nf_ct_is_dying(tmp) &&
 788                             atomic_inc_not_zero(&tmp->ct_general.use)) {
 789                                 ct = tmp;
 790                                 break;
 791                         }
 792                         cnt++;
 793                 }
 794
 795                 hash = (hash + 1) % net->ct.htable_size;
 796                 spin_unlock(lockp);
 797
 798                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 799                         break;
 800
 801         }
 802         local_bh_enable();
 803
 804         if (!ct)
 805                 return dropped;
 806
 807         if (del_timer(&ct->timeout)) {
 808                 if (nf_ct_delete(ct, 0, 0)) {
 809                         dropped = 1;
 810                         NF_CT_STAT_INC_ATOMIC(net, early_drop);
 811                 }
 812         }
 813         nf_ct_put(ct);
 814         return dropped;
 815 }
 816
 817 void init_nf_conntrack_hash_rnd(void)
 818 {
 819         unsigned int rand;
 820
 821         /*
 822          * Why not initialize nf_conntrack_rnd in a "init()" function ?
 823          * Because there isn't enough entropy when system initializing,
 824          * and we initialize it as late as possible.
 825          */
 826         do {
 827                 get_random_bytes(&rand, sizeof(rand));
 828         } while (!rand);
 829         cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
 830 }
 831
 832 static struct nf_conn *
 833 __nf_conntrack_alloc(struct net *net,
 834                      const struct nf_conntrack_zone *zone,
 835                      const struct nf_conntrack_tuple *orig,
 836                      const struct nf_conntrack_tuple *repl,
 837                      gfp_t gfp, u32 hash)
 838 {
 839         struct nf_conn *ct;
 840
 841         if (unlikely(!nf_conntrack_hash_rnd)) {
 842                 init_nf_conntrack_hash_rnd();
 843                 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
 844                 hash = hash_conntrack_raw(orig);
 845         }
 846
 847         /* We don't want any race condition at early drop stage */
 848         atomic_inc(&net->ct.count);
 849
 850         if (nf_conntrack_max &&
 851             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 852                 if (!early_drop(net, hash)) {
 853                         atomic_dec(&net->ct.count);
 854                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
 855                         return ERR_PTR(-ENOMEM);
 856                 }
 857         }
 858
 859         /*
 860          * Do not use kmem_cache_zalloc(), as this cache uses
 861          * SLAB_DESTROY_BY_RCU.
 862          */
 863         ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
 864         if (ct == NULL)
 865                 goto out;
 866
 867         spin_lock_init(&ct->lock);
 868         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 869         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
 870         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 871         /* save hash for reusing when confirming */
 872         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 873         ct->status = 0;
 874         /* Don't set timer yet: wait for confirmation */
 875         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 876         write_pnet(&ct->ct_net, net);
 877         memset(&ct->__nfct_init_offset[0], 0,
 878                offsetof(struct nf_conn, proto) -
 879                offsetof(struct nf_conn, __nfct_init_offset[0]));
 880
 881         if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
 882                 goto out_free;
 883
 884         /* Because we use RCU lookups, we set ct_general.use to zero before
 885          * this is inserted in any list.
 886          */
 887         atomic_set(&ct->ct_general.use, 0);
 888         return ct;
 889 out_free:
 890         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 891 out:
 892         atomic_dec(&net->ct.count);
 893         return ERR_PTR(-ENOMEM);
 894 }
 895
 896 struct nf_conn *nf_conntrack_alloc(struct net *net,
 897                                    const struct nf_conntrack_zone *zone,
 898                                    const struct nf_conntrack_tuple *orig,
 899                                    const struct nf_conntrack_tuple *repl,
 900                                    gfp_t gfp)
 901 {
 902         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
 903 }
 904 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 905
 906 void nf_conntrack_free(struct nf_conn *ct)
 907 {
 908         struct net *net = nf_ct_net(ct);
 909
 910         /* A freed object has refcnt == 0, that's
 911          * the golden rule for SLAB_DESTROY_BY_RCU
 912          */
 913         NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
 914
 915         nf_ct_ext_destroy(ct);
 916         nf_ct_ext_free(ct);
 917         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 918         smp_mb__before_atomic();
 919         atomic_dec(&net->ct.count);
 920 }
 921 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 922
 923
 924 /* Allocate a new conntrack: we return -ENOMEM if classification
 925    failed due to stress.  Otherwise it really is unclassifiable. */
 926 static struct nf_conntrack_tuple_hash *
 927 init_conntrack(struct net *net, struct nf_conn *tmpl,
 928                const struct nf_conntrack_tuple *tuple,
 929                struct nf_conntrack_l3proto *l3proto,
 930                struct nf_conntrack_l4proto *l4proto,
 931                struct sk_buff *skb,
 932                unsigned int dataoff, u32 hash)
 933 {
 934         struct nf_conn *ct;
 935         struct nf_conn_help *help;
 936         struct nf_conntrack_tuple repl_tuple;
 937         struct nf_conntrack_ecache *ecache;
 938         struct nf_conntrack_expect *exp = NULL;
 939         const struct nf_conntrack_zone *zone;
 940         struct nf_conn_timeout *timeout_ext;
 941         struct nf_conntrack_zone tmp;
 942         unsigned int *timeouts;
 943
 944         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 945                 pr_debug("Can't invert tuple.\n");
 946                 return NULL;
 947         }
 948
 949         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
 950         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 951                                   hash);
 952         if (IS_ERR(ct))
 953                 return (struct nf_conntrack_tuple_hash *)ct;
 954
 955         if (tmpl && nfct_synproxy(tmpl)) {
 956                 nfct_seqadj_ext_add(ct);
 957                 nfct_synproxy_ext_add(ct);
 958         }
 959
 960         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
 961         if (timeout_ext) {
 962                 timeouts = nf_ct_timeout_data(timeout_ext);
 963                 if (unlikely(!timeouts))
 964                         timeouts = l4proto->get_timeouts(net);
 965         } else {
 966                 timeouts = l4proto->get_timeouts(net);
 967         }
 968
 969         if (!l4proto->new(ct, skb, dataoff, timeouts)) {
 970                 nf_conntrack_free(ct);
 971                 pr_debug("init conntrack: can't track with proto module\n");
 972                 return NULL;
 973         }
 974
 975         if (timeout_ext)
 976                 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
 977                                       GFP_ATOMIC);
 978
 979         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 980         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
 981         nf_ct_labels_ext_add(ct);
 982
 983         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
 984         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
 985                                  ecache ? ecache->expmask : 0,
 986                              GFP_ATOMIC);
 987
 988         local_bh_disable();
 989         if (net->ct.expect_count) {
 990                 spin_lock(&nf_conntrack_expect_lock);
 991                 exp = nf_ct_find_expectation(net, zone, tuple);
 992                 if (exp) {
 993                         pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 994                                  ct, exp);
 995                         /* Welcome, Mr. Bond.  We've been expecting you... */
 996                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
 997                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
 998                         ct->master = exp->master;
 999                         if (exp->helper) {
1000                                 help = nf_ct_helper_ext_add(ct, exp->helper,
1001                                                             GFP_ATOMIC);
1002                                 if (help)
1003                                         rcu_assign_pointer(help->helper, exp->helper);
1004                         }
1005
1006 #ifdef CONFIG_NF_CONNTRACK_MARK
1007                         ct->mark = exp->master->mark;
1008 #endif
1009 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1010                         ct->secmark = exp->master->secmark;
1011 #endif
1012                         NF_CT_STAT_INC(net, expect_new);
1013                 }
1014                 spin_unlock(&nf_conntrack_expect_lock);
1015         }
1016         if (!exp) {
1017                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1018                 NF_CT_STAT_INC(net, new);
1019         }
1020
1021         /* Now it is inserted into the unconfirmed list, bump refcount */
1022         nf_conntrack_get(&ct->ct_general);
1023         nf_ct_add_to_unconfirmed_list(ct);
1024
1025         local_bh_enable();
1026
1027         if (exp) {
1028                 if (exp->expectfn)
1029                         exp->expectfn(ct, exp);
1030                 nf_ct_expect_put(exp);
1031         }
1032
1033         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1034 }
1035
1036 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1037 static inline struct nf_conn *
1038 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1039                   struct sk_buff *skb,
1040                   unsigned int dataoff,
1041                   u_int16_t l3num,
1042                   u_int8_t protonum,
1043                   struct nf_conntrack_l3proto *l3proto,
1044                   struct nf_conntrack_l4proto *l4proto,
1045                   int *set_reply,
1046                   enum ip_conntrack_info *ctinfo)
1047 {
1048         const struct nf_conntrack_zone *zone;
1049         struct nf_conntrack_tuple tuple;
1050         struct nf_conntrack_tuple_hash *h;
1051         struct nf_conntrack_zone tmp;
1052         struct nf_conn *ct;
1053         u32 hash;
1054
1055         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1056                              dataoff, l3num, protonum, net, &tuple, l3proto,
1057                              l4proto)) {
1058                 pr_debug("resolve_normal_ct: Can't get tuple\n");
1059                 return NULL;
1060         }
1061
1062         /* look for tuple match */
1063         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1064         hash = hash_conntrack_raw(&tuple);
1065         h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1066         if (!h) {
1067                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1068                                    skb, dataoff, hash);
1069                 if (!h)
1070                         return NULL;
1071                 if (IS_ERR(h))
1072                         return (void *)h;
1073         }
1074         ct = nf_ct_tuplehash_to_ctrack(h);
1075
1076         /* It exists; we have (non-exclusive) reference. */
1077         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1078                 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1079                 /* Please set reply bit if this packet OK */
1080                 *set_reply = 1;
1081         } else {
1082                 /* Once we've had two way comms, always ESTABLISHED. */
1083                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1084                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1085                         *ctinfo = IP_CT_ESTABLISHED;
1086                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1087                         pr_debug("nf_conntrack_in: related packet for %p\n",
1088                                  ct);
1089                         *ctinfo = IP_CT_RELATED;
1090                 } else {
1091                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1092                         *ctinfo = IP_CT_NEW;
1093                 }
1094                 *set_reply = 0;
1095         }
1096         skb->nfct = &ct->ct_general;
1097         skb->nfctinfo = *ctinfo;
1098         return ct;
1099 }
1100
1101 unsigned int
1102 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1103                 struct sk_buff *skb)
1104 {
1105         struct nf_conn *ct, *tmpl = NULL;
1106         enum ip_conntrack_info ctinfo;
1107         struct nf_conntrack_l3proto *l3proto;
1108         struct nf_conntrack_l4proto *l4proto;
1109         unsigned int *timeouts;
1110         unsigned int dataoff;
1111         u_int8_t protonum;
1112         int set_reply = 0;
1113         int ret;
1114
1115         if (skb->nfct) {
1116                 /* Previously seen (loopback or untracked)?  Ignore. */
1117                 tmpl = (struct nf_conn *)skb->nfct;
1118                 if (!nf_ct_is_template(tmpl)) {
1119                         NF_CT_STAT_INC_ATOMIC(net, ignore);
1120                         return NF_ACCEPT;
1121                 }
1122                 skb->nfct = NULL;
1123         }
1124
1125         /* rcu_read_lock()ed by nf_hook_slow */
1126         l3proto = __nf_ct_l3proto_find(pf);
1127         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1128                                    &dataoff, &protonum);
1129         if (ret <= 0) {
1130                 pr_debug("not prepared to track yet or error occurred\n");
1131                 NF_CT_STAT_INC_ATOMIC(net, error);
1132                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1133                 ret = -ret;
1134                 goto out;
1135         }
1136
1137         l4proto = __nf_ct_l4proto_find(pf, protonum);
1138
1139         /* It may be an special packet, error, unclean...
1140          * inverse of the return code tells to the netfilter
1141          * core what to do with the packet. */
1142         if (l4proto->error != NULL) {
1143                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1144                                      pf, hooknum);
1145                 if (ret <= 0) {
1146                         NF_CT_STAT_INC_ATOMIC(net, error);
1147                         NF_CT_STAT_INC_ATOMIC(net, invalid);
1148                         ret = -ret;
1149                         goto out;
1150                 }
1151                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1152                 if (skb->nfct)
1153                         goto out;
1154         }
1155
1156         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1157                                l3proto, l4proto, &set_reply, &ctinfo);
1158         if (!ct) {
1159                 /* Not valid part of a connection */
1160                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1161                 ret = NF_ACCEPT;
1162                 goto out;
1163         }
1164
1165         if (IS_ERR(ct)) {
1166                 /* Too stressed to deal. */
1167                 NF_CT_STAT_INC_ATOMIC(net, drop);
1168                 ret = NF_DROP;
1169                 goto out;
1170         }
1171
1172         NF_CT_ASSERT(skb->nfct);
1173
1174         /* Decide what timeout policy we want to apply to this flow. */
1175         timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1176
1177         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1178         if (ret <= 0) {
1179                 /* Invalid: inverse of the return code tells
1180                  * the netfilter core what to do */
1181                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1182                 nf_conntrack_put(skb->nfct);
1183                 skb->nfct = NULL;
1184                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1185                 if (ret == -NF_DROP)
1186                         NF_CT_STAT_INC_ATOMIC(net, drop);
1187                 ret = -ret;
1188                 goto out;
1189         }
1190
1191         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1192                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1193 out:
1194         if (tmpl) {
1195                 /* Special case: we have to repeat this hook, assign the
1196                  * template again to this packet. We assume that this packet
1197                  * has no conntrack assigned. This is used by nf_ct_tcp. */
1198                 if (ret == NF_REPEAT)
1199                         skb->nfct = (struct nf_conntrack *)tmpl;
1200                 else
1201                         nf_ct_put(tmpl);
1202         }
1203
1204         return ret;
1205 }
1206 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1207
1208 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1209                           const struct nf_conntrack_tuple *orig)
1210 {
1211         bool ret;
1212
1213         rcu_read_lock();
1214         ret = nf_ct_invert_tuple(inverse, orig,
1215                                  __nf_ct_l3proto_find(orig->src.l3num),
1216                                  __nf_ct_l4proto_find(orig->src.l3num,
1217                                                       orig->dst.protonum));
1218         rcu_read_unlock();
1219         return ret;
1220 }
1221 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1222
1223 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1224    implicitly racy: see __nf_conntrack_confirm */
1225 void nf_conntrack_alter_reply(struct nf_conn *ct,
1226                               const struct nf_conntrack_tuple *newreply)
1227 {
1228         struct nf_conn_help *help = nfct_help(ct);
1229
1230         /* Should be unconfirmed, so not in hash table yet */
1231         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1232
1233         pr_debug("Altering reply tuple of %p to ", ct);
1234         nf_ct_dump_tuple(newreply);
1235
1236         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1237         if (ct->master || (help && !hlist_empty(&help->expectations)))
1238                 return;
1239
1240         rcu_read_lock();
1241         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1242         rcu_read_unlock();
1243 }
1244 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1245
1246 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1247 void __nf_ct_refresh_acct(struct nf_conn *ct,
1248                           enum ip_conntrack_info ctinfo,
1249                           const struct sk_buff *skb,
1250                           unsigned long extra_jiffies,
1251                           int do_acct)
1252 {
1253         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1254         NF_CT_ASSERT(skb);
1255
1256         /* Only update if this is not a fixed timeout */
1257         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1258                 goto acct;
1259
1260         /* If not in hash table, timer will not be active yet */
1261         if (!nf_ct_is_confirmed(ct)) {
1262                 ct->timeout.expires = extra_jiffies;
1263         } else {
1264                 unsigned long newtime = jiffies + extra_jiffies;
1265
1266                 /* Only update the timeout if the new timeout is at least
1267                    HZ jiffies from the old timeout. Need del_timer for race
1268                    avoidance (may already be dying). */
1269                 if (newtime - ct->timeout.expires >= HZ)
1270                         mod_timer_pending(&ct->timeout, newtime);
1271         }
1272
1273 acct:
1274         if (do_acct) {
1275                 struct nf_conn_acct *acct;
1276
1277                 acct = nf_conn_acct_find(ct);
1278                 if (acct) {
1279                         struct nf_conn_counter *counter = acct->counter;
1280
1281                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1282                         atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1283                 }
1284         }
1285 }
1286 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1287
1288 bool __nf_ct_kill_acct(struct nf_conn *ct,
1289                        enum ip_conntrack_info ctinfo,
1290                        const struct sk_buff *skb,
1291                        int do_acct)
1292 {
1293         if (do_acct) {
1294                 struct nf_conn_acct *acct;
1295
1296                 acct = nf_conn_acct_find(ct);
1297                 if (acct) {
1298                         struct nf_conn_counter *counter = acct->counter;
1299
1300                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1301                         atomic64_add(skb->len - skb_network_offset(skb),
1302                                      &counter[CTINFO2DIR(ctinfo)].bytes);
1303                 }
1304         }
1305
1306         if (del_timer(&ct->timeout)) {
1307                 ct->timeout.function((unsigned long)ct);
1308                 return true;
1309         }
1310         return false;
1311 }
1312 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1313
1314 #ifdef CONFIG_NF_CONNTRACK_ZONES
1315 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1316         .len    = sizeof(struct nf_conntrack_zone),
1317         .align  = __alignof__(struct nf_conntrack_zone),
1318         .id     = NF_CT_EXT_ZONE,
1319 };
1320 #endif
1321
1322 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1323
1324 #include <linux/netfilter/nfnetlink.h>
1325 #include <linux/netfilter/nfnetlink_conntrack.h>
1326 #include <linux/mutex.h>
1327
1328 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1329  * in ip_conntrack_core, since we don't want the protocols to autoload
1330  * or depend on ctnetlink */
1331 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1332                                const struct nf_conntrack_tuple *tuple)
1333 {
1334         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1335             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1336                 goto nla_put_failure;
1337         return 0;
1338
1339 nla_put_failure:
1340         return -1;
1341 }
1342 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1343
1344 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1345         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1346         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1347 };
1348 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1349
1350 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1351                                struct nf_conntrack_tuple *t)
1352 {
1353         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1354                 return -EINVAL;
1355
1356         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1357         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1358
1359         return 0;
1360 }
1361 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1362
1363 int nf_ct_port_nlattr_tuple_size(void)
1364 {
1365         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1366 }
1367 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1368 #endif
1369
1370 /* Used by ipt_REJECT and ip6t_REJECT. */
1371 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1372 {
1373         struct nf_conn *ct;
1374         enum ip_conntrack_info ctinfo;
1375
1376         /* This ICMP is in reverse direction to the packet which caused it */
1377         ct = nf_ct_get(skb, &ctinfo);
1378         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1379                 ctinfo = IP_CT_RELATED_REPLY;
1380         else
1381                 ctinfo = IP_CT_RELATED;
1382
1383         /* Attach to new skbuff, and increment count */
1384         nskb->nfct = &ct->ct_general;
1385         nskb->nfctinfo = ctinfo;
1386         nf_conntrack_get(nskb->nfct);
1387 }
1388
1389 /* Bring out ya dead! */
1390 static struct nf_conn *
1391 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1392                 void *data, unsigned int *bucket)
1393 {
1394         struct nf_conntrack_tuple_hash *h;
1395         struct nf_conn *ct;
1396         struct hlist_nulls_node *n;
1397         int cpu;
1398         spinlock_t *lockp;
1399
1400         for (; *bucket < net->ct.htable_size; (*bucket)++) {
1401                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1402                 local_bh_disable();
1403                 nf_conntrack_lock(lockp);
1404                 if (*bucket < net->ct.htable_size) {
1405                         hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1406                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1407                                         continue;
1408                                 ct = nf_ct_tuplehash_to_ctrack(h);
1409                                 if (iter(ct, data))
1410                                         goto found;
1411                         }
1412                 }
1413                 spin_unlock(lockp);
1414                 local_bh_enable();
1415                 cond_resched();
1416         }
1417
1418         for_each_possible_cpu(cpu) {
1419                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1420
1421                 spin_lock_bh(&pcpu->lock);
1422                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1423                         ct = nf_ct_tuplehash_to_ctrack(h);
1424                         if (iter(ct, data))
1425                                 set_bit(IPS_DYING_BIT, &ct->status);
1426                 }
1427                 spin_unlock_bh(&pcpu->lock);
1428                 cond_resched();
1429         }
1430         return NULL;
1431 found:
1432         atomic_inc(&ct->ct_general.use);
1433         spin_unlock(lockp);
1434         local_bh_enable();
1435         return ct;
1436 }
1437
1438 void nf_ct_iterate_cleanup(struct net *net,
1439                            int (*iter)(struct nf_conn *i, void *data),
1440                            void *data, u32 portid, int report)
1441 {
1442         struct nf_conn *ct;
1443         unsigned int bucket = 0;
1444
1445         might_sleep();
1446
1447         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1448                 /* Time to push up daises... */
1449                 if (del_timer(&ct->timeout))
1450                         nf_ct_delete(ct, portid, report);
1451
1452                 /* ... else the timer will get him soon. */
1453
1454                 nf_ct_put(ct);
1455                 cond_resched();
1456         }
1457 }
1458 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1459
1460 static int kill_all(struct nf_conn *i, void *data)
1461 {
1462         return 1;
1463 }
1464
1465 void nf_ct_free_hashtable(void *hash, unsigned int size)
1466 {
1467         if (is_vmalloc_addr(hash))
1468                 vfree(hash);
1469         else
1470                 free_pages((unsigned long)hash,
1471                            get_order(sizeof(struct hlist_head) * size));
1472 }
1473 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1474
1475 static int untrack_refs(void)
1476 {
1477         int cnt = 0, cpu;
1478
1479         for_each_possible_cpu(cpu) {
1480                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1481
1482                 cnt += atomic_read(&ct->ct_general.use) - 1;
1483         }
1484         return cnt;
1485 }
1486
1487 void nf_conntrack_cleanup_start(void)
1488 {
1489         RCU_INIT_POINTER(ip_ct_attach, NULL);
1490 }
1491
1492 void nf_conntrack_cleanup_end(void)
1493 {
1494         RCU_INIT_POINTER(nf_ct_destroy, NULL);
1495         while (untrack_refs() > 0)
1496                 schedule();
1497
1498 #ifdef CONFIG_NF_CONNTRACK_ZONES
1499         nf_ct_extend_unregister(&nf_ct_zone_extend);
1500 #endif
1501         nf_conntrack_proto_fini();
1502         nf_conntrack_seqadj_fini();
1503         nf_conntrack_labels_fini();
1504         nf_conntrack_helper_fini();
1505         nf_conntrack_timeout_fini();
1506         nf_conntrack_ecache_fini();
1507         nf_conntrack_tstamp_fini();
1508         nf_conntrack_acct_fini();
1509         nf_conntrack_expect_fini();
1510 }
1511
1512 /*
1513  * Mishearing the voices in his head, our hero wonders how he's
1514  * supposed to kill the mall.
1515  */
1516 void nf_conntrack_cleanup_net(struct net *net)
1517 {
1518         LIST_HEAD(single);
1519
1520         list_add(&net->exit_list, &single);
1521         nf_conntrack_cleanup_net_list(&single);
1522 }
1523
1524 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1525 {
1526         int busy;
1527         struct net *net;
1528
1529         /*
1530          * This makes sure all current packets have passed through
1531          *  netfilter framework.  Roll on, two-stage module
1532          *  delete...
1533          */
1534         synchronize_net();
1535 i_see_dead_people:
1536         busy = 0;
1537         list_for_each_entry(net, net_exit_list, exit_list) {
1538                 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1539                 if (atomic_read(&net->ct.count) != 0)
1540                         busy = 1;
1541         }
1542         if (busy) {
1543                 schedule();
1544                 goto i_see_dead_people;
1545         }
1546
1547         list_for_each_entry(net, net_exit_list, exit_list) {
1548                 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1549                 nf_conntrack_proto_pernet_fini(net);
1550                 nf_conntrack_helper_pernet_fini(net);
1551                 nf_conntrack_ecache_pernet_fini(net);
1552                 nf_conntrack_tstamp_pernet_fini(net);
1553                 nf_conntrack_acct_pernet_fini(net);
1554                 nf_conntrack_expect_pernet_fini(net);
1555                 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1556                 kfree(net->ct.slabname);
1557                 free_percpu(net->ct.stat);
1558                 free_percpu(net->ct.pcpu_lists);
1559         }
1560 }
1561
1562 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1563 {
1564         struct hlist_nulls_head *hash;
1565         unsigned int nr_slots, i;
1566         size_t sz;
1567
1568         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1569         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1570         sz = nr_slots * sizeof(struct hlist_nulls_head);
1571         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1572                                         get_order(sz));
1573         if (!hash)
1574                 hash = vzalloc(sz);
1575
1576         if (hash && nulls)
1577                 for (i = 0; i < nr_slots; i++)
1578                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1579
1580         return hash;
1581 }
1582 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1583
1584 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1585 {
1586         int i, bucket, rc;
1587         unsigned int hashsize, old_size;
1588         struct hlist_nulls_head *hash, *old_hash;
1589         struct nf_conntrack_tuple_hash *h;
1590         struct nf_conn *ct;
1591
1592         if (current->nsproxy->net_ns != &init_net)
1593                 return -EOPNOTSUPP;
1594
1595         /* On boot, we can set this without any fancy locking. */
1596         if (!nf_conntrack_htable_size)
1597                 return param_set_uint(val, kp);
1598
1599         rc = kstrtouint(val, 0, &hashsize);
1600         if (rc)
1601                 return rc;
1602         if (!hashsize)
1603                 return -EINVAL;
1604
1605         hash = nf_ct_alloc_hashtable(&hashsize, 1);
1606         if (!hash)
1607                 return -ENOMEM;
1608
1609         local_bh_disable();
1610         nf_conntrack_all_lock();
1611         write_seqcount_begin(&init_net.ct.generation);
1612
1613         /* Lookups in the old hash might happen in parallel, which means we
1614          * might get false negatives during connection lookup. New connections
1615          * created because of a false negative won't make it into the hash
1616          * though since that required taking the locks.
1617          */
1618
1619         for (i = 0; i < init_net.ct.htable_size; i++) {
1620                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1621                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1622                                         struct nf_conntrack_tuple_hash, hnnode);
1623                         ct = nf_ct_tuplehash_to_ctrack(h);
1624                         hlist_nulls_del_rcu(&h->hnnode);
1625                         bucket = __hash_conntrack(&h->tuple, hashsize);
1626                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1627                 }
1628         }
1629         old_size = init_net.ct.htable_size;
1630         old_hash = init_net.ct.hash;
1631
1632         init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1633         init_net.ct.hash = hash;
1634
1635         write_seqcount_end(&init_net.ct.generation);
1636         nf_conntrack_all_unlock();
1637         local_bh_enable();
1638
1639         nf_ct_free_hashtable(old_hash, old_size);
1640         return 0;
1641 }
1642 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1643
1644 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1645                   &nf_conntrack_htable_size, 0600);
1646
1647 void nf_ct_untracked_status_or(unsigned long bits)
1648 {
1649         int cpu;
1650
1651         for_each_possible_cpu(cpu)
1652                 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1653 }
1654 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1655
1656 int nf_conntrack_init_start(void)
1657 {
1658         int max_factor = 8;
1659         int i, ret, cpu;
1660
1661         for (i = 0; i < CONNTRACK_LOCKS; i++)
1662                 spin_lock_init(&nf_conntrack_locks[i]);
1663
1664         if (!nf_conntrack_htable_size) {
1665                 /* Idea from tcp.c: use 1/16384 of memory.
1666                  * On i386: 32MB machine has 512 buckets.
1667                  * >= 1GB machines have 16384 buckets.
1668                  * >= 4GB machines have 65536 buckets.
1669                  */
1670                 nf_conntrack_htable_size
1671                         = (((totalram_pages << PAGE_SHIFT) / 16384)
1672                            / sizeof(struct hlist_head));
1673                 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1674                         nf_conntrack_htable_size = 65536;
1675                 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1676                         nf_conntrack_htable_size = 16384;
1677                 if (nf_conntrack_htable_size < 32)
1678                         nf_conntrack_htable_size = 32;
1679
1680                 /* Use a max. factor of four by default to get the same max as
1681                  * with the old struct list_heads. When a table size is given
1682                  * we use the old value of 8 to avoid reducing the max.
1683                  * entries. */
1684                 max_factor = 4;
1685         }
1686         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1687
1688         printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1689                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1690                nf_conntrack_max);
1691
1692         ret = nf_conntrack_expect_init();
1693         if (ret < 0)
1694                 goto err_expect;
1695
1696         ret = nf_conntrack_acct_init();
1697         if (ret < 0)
1698                 goto err_acct;
1699
1700         ret = nf_conntrack_tstamp_init();
1701         if (ret < 0)
1702                 goto err_tstamp;
1703
1704         ret = nf_conntrack_ecache_init();
1705         if (ret < 0)
1706                 goto err_ecache;
1707
1708         ret = nf_conntrack_timeout_init();
1709         if (ret < 0)
1710                 goto err_timeout;
1711
1712         ret = nf_conntrack_helper_init();
1713         if (ret < 0)
1714                 goto err_helper;
1715
1716         ret = nf_conntrack_labels_init();
1717         if (ret < 0)
1718                 goto err_labels;
1719
1720         ret = nf_conntrack_seqadj_init();
1721         if (ret < 0)
1722                 goto err_seqadj;
1723
1724 #ifdef CONFIG_NF_CONNTRACK_ZONES
1725         ret = nf_ct_extend_register(&nf_ct_zone_extend);
1726         if (ret < 0)
1727                 goto err_extend;
1728 #endif
1729         ret = nf_conntrack_proto_init();
1730         if (ret < 0)
1731                 goto err_proto;
1732
1733         /* Set up fake conntrack: to never be deleted, not in any hashes */
1734         for_each_possible_cpu(cpu) {
1735                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1736                 write_pnet(&ct->ct_net, &init_net);
1737                 atomic_set(&ct->ct_general.use, 1);
1738         }
1739         /*  - and look it like as a confirmed connection */
1740         nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1741         return 0;
1742
1743 err_proto:
1744 #ifdef CONFIG_NF_CONNTRACK_ZONES
1745         nf_ct_extend_unregister(&nf_ct_zone_extend);
1746 err_extend:
1747 #endif
1748         nf_conntrack_seqadj_fini();
1749 err_seqadj:
1750         nf_conntrack_labels_fini();
1751 err_labels:
1752         nf_conntrack_helper_fini();
1753 err_helper:
1754         nf_conntrack_timeout_fini();
1755 err_timeout:
1756         nf_conntrack_ecache_fini();
1757 err_ecache:
1758         nf_conntrack_tstamp_fini();
1759 err_tstamp:
1760         nf_conntrack_acct_fini();
1761 err_acct:
1762         nf_conntrack_expect_fini();
1763 err_expect:
1764         return ret;
1765 }
1766
1767 void nf_conntrack_init_end(void)
1768 {
1769         /* For use by REJECT target */
1770         RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1771         RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1772 }
1773
1774 /*
1775  * We need to use special "null" values, not used in hash table
1776  */
1777 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
1778 #define DYING_NULLS_VAL         ((1<<30)+1)
1779 #define TEMPLATE_NULLS_VAL      ((1<<30)+2)
1780
1781 int nf_conntrack_init_net(struct net *net)
1782 {
1783         int ret = -ENOMEM;
1784         int cpu;
1785
1786         atomic_set(&net->ct.count, 0);
1787         seqcount_init(&net->ct.generation);
1788
1789         net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1790         if (!net->ct.pcpu_lists)
1791                 goto err_stat;
1792
1793         for_each_possible_cpu(cpu) {
1794                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1795
1796                 spin_lock_init(&pcpu->lock);
1797                 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1798                 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1799         }
1800
1801         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1802         if (!net->ct.stat)
1803                 goto err_pcpu_lists;
1804
1805         net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1806         if (!net->ct.slabname)
1807                 goto err_slabname;
1808
1809         net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1810                                                         sizeof(struct nf_conn), 0,
1811                                                         SLAB_DESTROY_BY_RCU, NULL);
1812         if (!net->ct.nf_conntrack_cachep) {
1813                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1814                 goto err_cache;
1815         }
1816
1817         net->ct.htable_size = nf_conntrack_htable_size;
1818         net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1819         if (!net->ct.hash) {
1820                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1821                 goto err_hash;
1822         }
1823         ret = nf_conntrack_expect_pernet_init(net);
1824         if (ret < 0)
1825                 goto err_expect;
1826         ret = nf_conntrack_acct_pernet_init(net);
1827         if (ret < 0)
1828                 goto err_acct;
1829         ret = nf_conntrack_tstamp_pernet_init(net);
1830         if (ret < 0)
1831                 goto err_tstamp;
1832         ret = nf_conntrack_ecache_pernet_init(net);
1833         if (ret < 0)
1834                 goto err_ecache;
1835         ret = nf_conntrack_helper_pernet_init(net);
1836         if (ret < 0)
1837                 goto err_helper;
1838         ret = nf_conntrack_proto_pernet_init(net);
1839         if (ret < 0)
1840                 goto err_proto;
1841         return 0;
1842
1843 err_proto:
1844         nf_conntrack_helper_pernet_fini(net);
1845 err_helper:
1846         nf_conntrack_ecache_pernet_fini(net);
1847 err_ecache:
1848         nf_conntrack_tstamp_pernet_fini(net);
1849 err_tstamp:
1850         nf_conntrack_acct_pernet_fini(net);
1851 err_acct:
1852         nf_conntrack_expect_pernet_fini(net);
1853 err_expect:
1854         nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1855 err_hash:
1856         kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1857 err_cache:
1858         kfree(net->ct.slabname);
1859 err_slabname:
1860         free_percpu(net->ct.stat);
1861 err_pcpu_lists:
1862         free_percpu(net->ct.pcpu_lists);
1863 err_stat:
1864         return ret;
1865 }