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, u16 zone)
 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, zone ^ 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                                   u16 zone, unsigned int size)
 155 {
 156         return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
 157 }
 158
 159 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
 160                                        const struct nf_conntrack_tuple *tuple)
 161 {
 162         return __hash_conntrack(tuple, zone, 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 nf_conntrack_tuple *tuple,
 172                 const struct nf_conntrack_l3proto *l3proto,
 173                 const struct nf_conntrack_l4proto *l4proto)
 174 {
 175         memset(tuple, 0, sizeof(*tuple));
 176
 177         tuple->src.l3num = l3num;
 178         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 179                 return false;
 180
 181         tuple->dst.protonum = protonum;
 182         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 183
 184         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 185 }
 186 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
 187
 188 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 189                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
 190 {
 191         struct nf_conntrack_l3proto *l3proto;
 192         struct nf_conntrack_l4proto *l4proto;
 193         unsigned int protoff;
 194         u_int8_t protonum;
 195         int ret;
 196
 197         rcu_read_lock();
 198
 199         l3proto = __nf_ct_l3proto_find(l3num);
 200         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
 201         if (ret != NF_ACCEPT) {
 202                 rcu_read_unlock();
 203                 return false;
 204         }
 205
 206         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 207
 208         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
 209                               l3proto, l4proto);
 210
 211         rcu_read_unlock();
 212         return ret;
 213 }
 214 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 215
 216 bool
 217 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 218                    const struct nf_conntrack_tuple *orig,
 219                    const struct nf_conntrack_l3proto *l3proto,
 220                    const struct nf_conntrack_l4proto *l4proto)
 221 {
 222         memset(inverse, 0, sizeof(*inverse));
 223
 224         inverse->src.l3num = orig->src.l3num;
 225         if (l3proto->invert_tuple(inverse, orig) == 0)
 226                 return false;
 227
 228         inverse->dst.dir = !orig->dst.dir;
 229
 230         inverse->dst.protonum = orig->dst.protonum;
 231         return l4proto->invert_tuple(inverse, orig);
 232 }
 233 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 234
 235 static void
 236 clean_from_lists(struct nf_conn *ct)
 237 {
 238         pr_debug("clean_from_lists(%p)\n", ct);
 239         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 240         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 241
 242         /* Destroy all pending expectations */
 243         nf_ct_remove_expectations(ct);
 244 }
 245
 246 /* must be called with local_bh_disable */
 247 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
 248 {
 249         struct ct_pcpu *pcpu;
 250
 251         /* add this conntrack to the (per cpu) dying list */
 252         ct->cpu = smp_processor_id();
 253         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 254
 255         spin_lock(&pcpu->lock);
 256         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 257                              &pcpu->dying);
 258         spin_unlock(&pcpu->lock);
 259 }
 260
 261 /* must be called with local_bh_disable */
 262 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
 263 {
 264         struct ct_pcpu *pcpu;
 265
 266         /* add this conntrack to the (per cpu) unconfirmed list */
 267         ct->cpu = smp_processor_id();
 268         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 269
 270         spin_lock(&pcpu->lock);
 271         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 272                              &pcpu->unconfirmed);
 273         spin_unlock(&pcpu->lock);
 274 }
 275
 276 /* must be called with local_bh_disable */
 277 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
 278 {
 279         struct ct_pcpu *pcpu;
 280
 281         /* We overload first tuple to link into unconfirmed or dying list.*/
 282         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 283
 284         spin_lock(&pcpu->lock);
 285         BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 286         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 287         spin_unlock(&pcpu->lock);
 288 }
 289
 290 /* Released via destroy_conntrack() */
 291 struct nf_conn *nf_ct_tmpl_alloc(struct net *net, u16 zone, gfp_t flags)
 292 {
 293         struct nf_conn *tmpl;
 294
 295         tmpl = kzalloc(sizeof(struct nf_conn), GFP_KERNEL);
 296         if (tmpl == NULL)
 297                 return NULL;
 298
 299         tmpl->status = IPS_TEMPLATE;
 300         write_pnet(&tmpl->ct_net, net);
 301
 302 #ifdef CONFIG_NF_CONNTRACK_ZONES
 303         if (zone) {
 304                 struct nf_conntrack_zone *nf_ct_zone;
 305
 306                 nf_ct_zone = nf_ct_ext_add(tmpl, NF_CT_EXT_ZONE, GFP_ATOMIC);
 307                 if (!nf_ct_zone)
 308                         goto out_free;
 309                 nf_ct_zone->id = zone;
 310         }
 311 #endif
 312         atomic_set(&tmpl->ct_general.use, 0);
 313
 314         return tmpl;
 315 #ifdef CONFIG_NF_CONNTRACK_ZONES
 316 out_free:
 317         kfree(tmpl);
 318         return NULL;
 319 #endif
 320 }
 321 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
 322
 323 static void nf_ct_tmpl_free(struct nf_conn *tmpl)
 324 {
 325         nf_ct_ext_destroy(tmpl);
 326         nf_ct_ext_free(tmpl);
 327         kfree(tmpl);
 328 }
 329
 330 static void
 331 destroy_conntrack(struct nf_conntrack *nfct)
 332 {
 333         struct nf_conn *ct = (struct nf_conn *)nfct;
 334         struct net *net = nf_ct_net(ct);
 335         struct nf_conntrack_l4proto *l4proto;
 336
 337         pr_debug("destroy_conntrack(%p)\n", ct);
 338         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 339         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 340
 341         if (unlikely(nf_ct_is_template(ct))) {
 342                 nf_ct_tmpl_free(ct);
 343                 return;
 344         }
 345         rcu_read_lock();
 346         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 347         if (l4proto && l4proto->destroy)
 348                 l4proto->destroy(ct);
 349
 350         rcu_read_unlock();
 351
 352         local_bh_disable();
 353         /* Expectations will have been removed in clean_from_lists,
 354          * except TFTP can create an expectation on the first packet,
 355          * before connection is in the list, so we need to clean here,
 356          * too.
 357          */
 358         nf_ct_remove_expectations(ct);
 359
 360         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 361
 362         NF_CT_STAT_INC(net, delete);
 363         local_bh_enable();
 364
 365         if (ct->master)
 366                 nf_ct_put(ct->master);
 367
 368         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 369         nf_conntrack_free(ct);
 370 }
 371
 372 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 373 {
 374         struct net *net = nf_ct_net(ct);
 375         unsigned int hash, reply_hash;
 376         u16 zone = nf_ct_zone(ct);
 377         unsigned int sequence;
 378
 379         nf_ct_helper_destroy(ct);
 380
 381         local_bh_disable();
 382         do {
 383                 sequence = read_seqcount_begin(&net->ct.generation);
 384                 hash = hash_conntrack(net, zone,
 385                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 386                 reply_hash = hash_conntrack(net, zone,
 387                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 388         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 389
 390         clean_from_lists(ct);
 391         nf_conntrack_double_unlock(hash, reply_hash);
 392
 393         nf_ct_add_to_dying_list(ct);
 394
 395         NF_CT_STAT_INC(net, delete_list);
 396         local_bh_enable();
 397 }
 398
 399 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 400 {
 401         struct nf_conn_tstamp *tstamp;
 402
 403         tstamp = nf_conn_tstamp_find(ct);
 404         if (tstamp && tstamp->stop == 0)
 405                 tstamp->stop = ktime_get_real_ns();
 406
 407         if (nf_ct_is_dying(ct))
 408                 goto delete;
 409
 410         if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 411                                     portid, report) < 0) {
 412                 /* destroy event was not delivered */
 413                 nf_ct_delete_from_lists(ct);
 414                 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
 415                 return false;
 416         }
 417
 418         nf_conntrack_ecache_work(nf_ct_net(ct));
 419         set_bit(IPS_DYING_BIT, &ct->status);
 420  delete:
 421         nf_ct_delete_from_lists(ct);
 422         nf_ct_put(ct);
 423         return true;
 424 }
 425 EXPORT_SYMBOL_GPL(nf_ct_delete);
 426
 427 static void death_by_timeout(unsigned long ul_conntrack)
 428 {
 429         nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
 430 }
 431
 432 static inline bool
 433 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 434                         const struct nf_conntrack_tuple *tuple,
 435                         u16 zone)
 436 {
 437         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 438
 439         /* A conntrack can be recreated with the equal tuple,
 440          * so we need to check that the conntrack is confirmed
 441          */
 442         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 443                 nf_ct_zone(ct) == zone &&
 444                 nf_ct_is_confirmed(ct);
 445 }
 446
 447 /*
 448  * Warning :
 449  * - Caller must take a reference on returned object
 450  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 451  */
 452 static struct nf_conntrack_tuple_hash *
 453 ____nf_conntrack_find(struct net *net, u16 zone,
 454                       const struct nf_conntrack_tuple *tuple, u32 hash)
 455 {
 456         struct nf_conntrack_tuple_hash *h;
 457         struct hlist_nulls_node *n;
 458         unsigned int bucket = hash_bucket(hash, net);
 459
 460         /* Disable BHs the entire time since we normally need to disable them
 461          * at least once for the stats anyway.
 462          */
 463         local_bh_disable();
 464 begin:
 465         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
 466                 if (nf_ct_key_equal(h, tuple, zone)) {
 467                         NF_CT_STAT_INC(net, found);
 468                         local_bh_enable();
 469                         return h;
 470                 }
 471                 NF_CT_STAT_INC(net, searched);
 472         }
 473         /*
 474          * if the nulls value we got at the end of this lookup is
 475          * not the expected one, we must restart lookup.
 476          * We probably met an item that was moved to another chain.
 477          */
 478         if (get_nulls_value(n) != bucket) {
 479                 NF_CT_STAT_INC(net, search_restart);
 480                 goto begin;
 481         }
 482         local_bh_enable();
 483
 484         return NULL;
 485 }
 486
 487 /* Find a connection corresponding to a tuple. */
 488 static struct nf_conntrack_tuple_hash *
 489 __nf_conntrack_find_get(struct net *net, u16 zone,
 490                         const struct nf_conntrack_tuple *tuple, u32 hash)
 491 {
 492         struct nf_conntrack_tuple_hash *h;
 493         struct nf_conn *ct;
 494
 495         rcu_read_lock();
 496 begin:
 497         h = ____nf_conntrack_find(net, zone, tuple, hash);
 498         if (h) {
 499                 ct = nf_ct_tuplehash_to_ctrack(h);
 500                 if (unlikely(nf_ct_is_dying(ct) ||
 501                              !atomic_inc_not_zero(&ct->ct_general.use)))
 502                         h = NULL;
 503                 else {
 504                         if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
 505                                 nf_ct_put(ct);
 506                                 goto begin;
 507                         }
 508                 }
 509         }
 510         rcu_read_unlock();
 511
 512         return h;
 513 }
 514
 515 struct nf_conntrack_tuple_hash *
 516 nf_conntrack_find_get(struct net *net, u16 zone,
 517                       const struct nf_conntrack_tuple *tuple)
 518 {
 519         return __nf_conntrack_find_get(net, zone, tuple,
 520                                        hash_conntrack_raw(tuple, zone));
 521 }
 522 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 523
 524 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 525                                        unsigned int hash,
 526                                        unsigned int reply_hash)
 527 {
 528         struct net *net = nf_ct_net(ct);
 529
 530         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 531                            &net->ct.hash[hash]);
 532         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 533                            &net->ct.hash[reply_hash]);
 534 }
 535
 536 int
 537 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 538 {
 539         struct net *net = nf_ct_net(ct);
 540         unsigned int hash, reply_hash;
 541         struct nf_conntrack_tuple_hash *h;
 542         struct hlist_nulls_node *n;
 543         u16 zone;
 544         unsigned int sequence;
 545
 546         zone = nf_ct_zone(ct);
 547
 548         local_bh_disable();
 549         do {
 550                 sequence = read_seqcount_begin(&net->ct.generation);
 551                 hash = hash_conntrack(net, zone,
 552                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 553                 reply_hash = hash_conntrack(net, zone,
 554                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 555         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 556
 557         /* See if there's one in the list already, including reverse */
 558         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 559                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 560                                       &h->tuple) &&
 561                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 562                         goto out;
 563         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 564                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 565                                       &h->tuple) &&
 566                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 567                         goto out;
 568
 569         add_timer(&ct->timeout);
 570         smp_wmb();
 571         /* The caller holds a reference to this object */
 572         atomic_set(&ct->ct_general.use, 2);
 573         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 574         nf_conntrack_double_unlock(hash, reply_hash);
 575         NF_CT_STAT_INC(net, insert);
 576         local_bh_enable();
 577         return 0;
 578
 579 out:
 580         nf_conntrack_double_unlock(hash, reply_hash);
 581         NF_CT_STAT_INC(net, insert_failed);
 582         local_bh_enable();
 583         return -EEXIST;
 584 }
 585 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 586
 587 /* Confirm a connection given skb; places it in hash table */
 588 int
 589 __nf_conntrack_confirm(struct sk_buff *skb)
 590 {
 591         unsigned int hash, reply_hash;
 592         struct nf_conntrack_tuple_hash *h;
 593         struct nf_conn *ct;
 594         struct nf_conn_help *help;
 595         struct nf_conn_tstamp *tstamp;
 596         struct hlist_nulls_node *n;
 597         enum ip_conntrack_info ctinfo;
 598         struct net *net;
 599         u16 zone;
 600         unsigned int sequence;
 601
 602         ct = nf_ct_get(skb, &ctinfo);
 603         net = nf_ct_net(ct);
 604
 605         /* ipt_REJECT uses nf_conntrack_attach to attach related
 606            ICMP/TCP RST packets in other direction.  Actual packet
 607            which created connection will be IP_CT_NEW or for an
 608            expected connection, IP_CT_RELATED. */
 609         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 610                 return NF_ACCEPT;
 611
 612         zone = nf_ct_zone(ct);
 613         local_bh_disable();
 614
 615         do {
 616                 sequence = read_seqcount_begin(&net->ct.generation);
 617                 /* reuse the hash saved before */
 618                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 619                 hash = hash_bucket(hash, net);
 620                 reply_hash = hash_conntrack(net, zone,
 621                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 622
 623         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 624
 625         /* We're not in hash table, and we refuse to set up related
 626          * connections for unconfirmed conns.  But packet copies and
 627          * REJECT will give spurious warnings here.
 628          */
 629         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 630
 631         /* No external references means no one else could have
 632          * confirmed us.
 633          */
 634         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 635         pr_debug("Confirming conntrack %p\n", ct);
 636         /* We have to check the DYING flag after unlink to prevent
 637          * a race against nf_ct_get_next_corpse() possibly called from
 638          * user context, else we insert an already 'dead' hash, blocking
 639          * further use of that particular connection -JM.
 640          */
 641         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 642
 643         if (unlikely(nf_ct_is_dying(ct)))
 644                 goto out;
 645
 646         /* See if there's one in the list already, including reverse:
 647            NAT could have grabbed it without realizing, since we're
 648            not in the hash.  If there is, we lost race. */
 649         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 650                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 651                                       &h->tuple) &&
 652                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 653                         goto out;
 654         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 655                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 656                                       &h->tuple) &&
 657                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 658                         goto out;
 659
 660         /* Timer relative to confirmation time, not original
 661            setting time, otherwise we'd get timer wrap in
 662            weird delay cases. */
 663         ct->timeout.expires += jiffies;
 664         add_timer(&ct->timeout);
 665         atomic_inc(&ct->ct_general.use);
 666         ct->status |= IPS_CONFIRMED;
 667
 668         /* set conntrack timestamp, if enabled. */
 669         tstamp = nf_conn_tstamp_find(ct);
 670         if (tstamp) {
 671                 if (skb->tstamp.tv64 == 0)
 672                         __net_timestamp(skb);
 673
 674                 tstamp->start = ktime_to_ns(skb->tstamp);
 675         }
 676         /* Since the lookup is lockless, hash insertion must be done after
 677          * starting the timer and setting the CONFIRMED bit. The RCU barriers
 678          * guarantee that no other CPU can find the conntrack before the above
 679          * stores are visible.
 680          */
 681         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 682         nf_conntrack_double_unlock(hash, reply_hash);
 683         NF_CT_STAT_INC(net, insert);
 684         local_bh_enable();
 685
 686         help = nfct_help(ct);
 687         if (help && help->helper)
 688                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 689
 690         nf_conntrack_event_cache(master_ct(ct) ?
 691                                  IPCT_RELATED : IPCT_NEW, ct);
 692         return NF_ACCEPT;
 693
 694 out:
 695         nf_ct_add_to_dying_list(ct);
 696         nf_conntrack_double_unlock(hash, reply_hash);
 697         NF_CT_STAT_INC(net, insert_failed);
 698         local_bh_enable();
 699         return NF_DROP;
 700 }
 701 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 702
 703 /* Returns true if a connection correspondings to the tuple (required
 704    for NAT). */
 705 int
 706 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 707                          const struct nf_conn *ignored_conntrack)
 708 {
 709         struct net *net = nf_ct_net(ignored_conntrack);
 710         struct nf_conntrack_tuple_hash *h;
 711         struct hlist_nulls_node *n;
 712         struct nf_conn *ct;
 713         u16 zone = nf_ct_zone(ignored_conntrack);
 714         unsigned int hash = hash_conntrack(net, zone, tuple);
 715
 716         /* Disable BHs the entire time since we need to disable them at
 717          * least once for the stats anyway.
 718          */
 719         rcu_read_lock_bh();
 720         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 721                 ct = nf_ct_tuplehash_to_ctrack(h);
 722                 if (ct != ignored_conntrack &&
 723                     nf_ct_tuple_equal(tuple, &h->tuple) &&
 724                     nf_ct_zone(ct) == zone) {
 725                         NF_CT_STAT_INC(net, found);
 726                         rcu_read_unlock_bh();
 727                         return 1;
 728                 }
 729                 NF_CT_STAT_INC(net, searched);
 730         }
 731         rcu_read_unlock_bh();
 732
 733         return 0;
 734 }
 735 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 736
 737 #define NF_CT_EVICTION_RANGE    8
 738
 739 /* There's a small race here where we may free a just-assured
 740    connection.  Too bad: we're in trouble anyway. */
 741 static noinline int early_drop(struct net *net, unsigned int _hash)
 742 {
 743         /* Use oldest entry, which is roughly LRU */
 744         struct nf_conntrack_tuple_hash *h;
 745         struct nf_conn *ct = NULL, *tmp;
 746         struct hlist_nulls_node *n;
 747         unsigned int i = 0, cnt = 0;
 748         int dropped = 0;
 749         unsigned int hash, sequence;
 750         spinlock_t *lockp;
 751
 752         local_bh_disable();
 753 restart:
 754         sequence = read_seqcount_begin(&net->ct.generation);
 755         hash = hash_bucket(_hash, net);
 756         for (; i < net->ct.htable_size; i++) {
 757                 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
 758                 spin_lock(lockp);
 759                 if (read_seqcount_retry(&net->ct.generation, sequence)) {
 760                         spin_unlock(lockp);
 761                         goto restart;
 762                 }
 763                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 764                                          hnnode) {
 765                         tmp = nf_ct_tuplehash_to_ctrack(h);
 766                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
 767                             !nf_ct_is_dying(tmp) &&
 768                             atomic_inc_not_zero(&tmp->ct_general.use)) {
 769                                 ct = tmp;
 770                                 break;
 771                         }
 772                         cnt++;
 773                 }
 774
 775                 hash = (hash + 1) % net->ct.htable_size;
 776                 spin_unlock(lockp);
 777
 778                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 779                         break;
 780
 781         }
 782         local_bh_enable();
 783
 784         if (!ct)
 785                 return dropped;
 786
 787         if (del_timer(&ct->timeout)) {
 788                 if (nf_ct_delete(ct, 0, 0)) {
 789                         dropped = 1;
 790                         NF_CT_STAT_INC_ATOMIC(net, early_drop);
 791                 }
 792         }
 793         nf_ct_put(ct);
 794         return dropped;
 795 }
 796
 797 void init_nf_conntrack_hash_rnd(void)
 798 {
 799         unsigned int rand;
 800
 801         /*
 802          * Why not initialize nf_conntrack_rnd in a "init()" function ?
 803          * Because there isn't enough entropy when system initializing,
 804          * and we initialize it as late as possible.
 805          */
 806         do {
 807                 get_random_bytes(&rand, sizeof(rand));
 808         } while (!rand);
 809         cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
 810 }
 811
 812 static struct nf_conn *
 813 __nf_conntrack_alloc(struct net *net, u16 zone,
 814                      const struct nf_conntrack_tuple *orig,
 815                      const struct nf_conntrack_tuple *repl,
 816                      gfp_t gfp, u32 hash)
 817 {
 818         struct nf_conn *ct;
 819
 820         if (unlikely(!nf_conntrack_hash_rnd)) {
 821                 init_nf_conntrack_hash_rnd();
 822                 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
 823                 hash = hash_conntrack_raw(orig, zone);
 824         }
 825
 826         /* We don't want any race condition at early drop stage */
 827         atomic_inc(&net->ct.count);
 828
 829         if (nf_conntrack_max &&
 830             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 831                 if (!early_drop(net, hash)) {
 832                         atomic_dec(&net->ct.count);
 833                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
 834                         return ERR_PTR(-ENOMEM);
 835                 }
 836         }
 837
 838         /*
 839          * Do not use kmem_cache_zalloc(), as this cache uses
 840          * SLAB_DESTROY_BY_RCU.
 841          */
 842         ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
 843         if (ct == NULL) {
 844                 atomic_dec(&net->ct.count);
 845                 return ERR_PTR(-ENOMEM);
 846         }
 847         spin_lock_init(&ct->lock);
 848         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 849         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
 850         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 851         /* save hash for reusing when confirming */
 852         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 853         ct->status = 0;
 854         /* Don't set timer yet: wait for confirmation */
 855         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 856         write_pnet(&ct->ct_net, net);
 857         memset(&ct->__nfct_init_offset[0], 0,
 858                offsetof(struct nf_conn, proto) -
 859                offsetof(struct nf_conn, __nfct_init_offset[0]));
 860 #ifdef CONFIG_NF_CONNTRACK_ZONES
 861         if (zone) {
 862                 struct nf_conntrack_zone *nf_ct_zone;
 863
 864                 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
 865                 if (!nf_ct_zone)
 866                         goto out_free;
 867                 nf_ct_zone->id = zone;
 868         }
 869 #endif
 870         /* Because we use RCU lookups, we set ct_general.use to zero before
 871          * this is inserted in any list.
 872          */
 873         atomic_set(&ct->ct_general.use, 0);
 874         return ct;
 875
 876 #ifdef CONFIG_NF_CONNTRACK_ZONES
 877 out_free:
 878         atomic_dec(&net->ct.count);
 879         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 880         return ERR_PTR(-ENOMEM);
 881 #endif
 882 }
 883
 884 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
 885                                    const struct nf_conntrack_tuple *orig,
 886                                    const struct nf_conntrack_tuple *repl,
 887                                    gfp_t gfp)
 888 {
 889         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
 890 }
 891 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 892
 893 void nf_conntrack_free(struct nf_conn *ct)
 894 {
 895         struct net *net = nf_ct_net(ct);
 896
 897         /* A freed object has refcnt == 0, that's
 898          * the golden rule for SLAB_DESTROY_BY_RCU
 899          */
 900         NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
 901
 902         nf_ct_ext_destroy(ct);
 903         nf_ct_ext_free(ct);
 904         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 905         smp_mb__before_atomic();
 906         atomic_dec(&net->ct.count);
 907 }
 908 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 909
 910
 911 /* Allocate a new conntrack: we return -ENOMEM if classification
 912    failed due to stress.  Otherwise it really is unclassifiable. */
 913 static struct nf_conntrack_tuple_hash *
 914 init_conntrack(struct net *net, struct nf_conn *tmpl,
 915                const struct nf_conntrack_tuple *tuple,
 916                struct nf_conntrack_l3proto *l3proto,
 917                struct nf_conntrack_l4proto *l4proto,
 918                struct sk_buff *skb,
 919                unsigned int dataoff, u32 hash)
 920 {
 921         struct nf_conn *ct;
 922         struct nf_conn_help *help;
 923         struct nf_conntrack_tuple repl_tuple;
 924         struct nf_conntrack_ecache *ecache;
 925         struct nf_conntrack_expect *exp = NULL;
 926         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
 927         struct nf_conn_timeout *timeout_ext;
 928         unsigned int *timeouts;
 929
 930         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 931                 pr_debug("Can't invert tuple.\n");
 932                 return NULL;
 933         }
 934
 935         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 936                                   hash);
 937         if (IS_ERR(ct))
 938                 return (struct nf_conntrack_tuple_hash *)ct;
 939
 940         if (tmpl && nfct_synproxy(tmpl)) {
 941                 nfct_seqadj_ext_add(ct);
 942                 nfct_synproxy_ext_add(ct);
 943         }
 944
 945         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
 946         if (timeout_ext)
 947                 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
 948         else
 949                 timeouts = l4proto->get_timeouts(net);
 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, timeout_ext->timeout, GFP_ATOMIC);
 959
 960         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 961         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
 962         nf_ct_labels_ext_add(ct);
 963
 964         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
 965         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
 966                                  ecache ? ecache->expmask : 0,
 967                              GFP_ATOMIC);
 968
 969         local_bh_disable();
 970         if (net->ct.expect_count) {
 971                 spin_lock(&nf_conntrack_expect_lock);
 972                 exp = nf_ct_find_expectation(net, zone, tuple);
 973                 if (exp) {
 974                         pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 975                                  ct, exp);
 976                         /* Welcome, Mr. Bond.  We've been expecting you... */
 977                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
 978                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
 979                         ct->master = exp->master;
 980                         if (exp->helper) {
 981                                 help = nf_ct_helper_ext_add(ct, exp->helper,
 982                                                             GFP_ATOMIC);
 983                                 if (help)
 984                                         rcu_assign_pointer(help->helper, exp->helper);
 985                         }
 986
 987 #ifdef CONFIG_NF_CONNTRACK_MARK
 988                         ct->mark = exp->master->mark;
 989 #endif
 990 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 991                         ct->secmark = exp->master->secmark;
 992 #endif
 993                         NF_CT_STAT_INC(net, expect_new);
 994                 }
 995                 spin_unlock(&nf_conntrack_expect_lock);
 996         }
 997         if (!exp) {
 998                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
 999                 NF_CT_STAT_INC(net, new);
1000         }
1001
1002         /* Now it is inserted into the unconfirmed list, bump refcount */
1003         nf_conntrack_get(&ct->ct_general);
1004         nf_ct_add_to_unconfirmed_list(ct);
1005
1006         local_bh_enable();
1007
1008         if (exp) {
1009                 if (exp->expectfn)
1010                         exp->expectfn(ct, exp);
1011                 nf_ct_expect_put(exp);
1012         }
1013
1014         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1015 }
1016
1017 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1018 static inline struct nf_conn *
1019 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1020                   struct sk_buff *skb,
1021                   unsigned int dataoff,
1022                   u_int16_t l3num,
1023                   u_int8_t protonum,
1024                   struct nf_conntrack_l3proto *l3proto,
1025                   struct nf_conntrack_l4proto *l4proto,
1026                   int *set_reply,
1027                   enum ip_conntrack_info *ctinfo)
1028 {
1029         struct nf_conntrack_tuple tuple;
1030         struct nf_conntrack_tuple_hash *h;
1031         struct nf_conn *ct;
1032         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
1033         u32 hash;
1034
1035         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1036                              dataoff, l3num, protonum, &tuple, l3proto,
1037                              l4proto)) {
1038                 pr_debug("resolve_normal_ct: Can't get tuple\n");
1039                 return NULL;
1040         }
1041
1042         /* look for tuple match */
1043         hash = hash_conntrack_raw(&tuple, zone);
1044         h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1045         if (!h) {
1046                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1047                                    skb, dataoff, hash);
1048                 if (!h)
1049                         return NULL;
1050                 if (IS_ERR(h))
1051                         return (void *)h;
1052         }
1053         ct = nf_ct_tuplehash_to_ctrack(h);
1054
1055         /* It exists; we have (non-exclusive) reference. */
1056         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1057                 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1058                 /* Please set reply bit if this packet OK */
1059                 *set_reply = 1;
1060         } else {
1061                 /* Once we've had two way comms, always ESTABLISHED. */
1062                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1063                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1064                         *ctinfo = IP_CT_ESTABLISHED;
1065                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1066                         pr_debug("nf_conntrack_in: related packet for %p\n",
1067                                  ct);
1068                         *ctinfo = IP_CT_RELATED;
1069                 } else {
1070                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1071                         *ctinfo = IP_CT_NEW;
1072                 }
1073                 *set_reply = 0;
1074         }
1075         skb->nfct = &ct->ct_general;
1076         skb->nfctinfo = *ctinfo;
1077         return ct;
1078 }
1079
1080 unsigned int
1081 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1082                 struct sk_buff *skb)
1083 {
1084         struct nf_conn *ct, *tmpl = NULL;
1085         enum ip_conntrack_info ctinfo;
1086         struct nf_conntrack_l3proto *l3proto;
1087         struct nf_conntrack_l4proto *l4proto;
1088         unsigned int *timeouts;
1089         unsigned int dataoff;
1090         u_int8_t protonum;
1091         int set_reply = 0;
1092         int ret;
1093
1094         if (skb->nfct) {
1095                 /* Previously seen (loopback or untracked)?  Ignore. */
1096                 tmpl = (struct nf_conn *)skb->nfct;
1097                 if (!nf_ct_is_template(tmpl)) {
1098                         NF_CT_STAT_INC_ATOMIC(net, ignore);
1099                         return NF_ACCEPT;
1100                 }
1101                 skb->nfct = NULL;
1102         }
1103
1104         /* rcu_read_lock()ed by nf_hook_slow */
1105         l3proto = __nf_ct_l3proto_find(pf);
1106         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1107                                    &dataoff, &protonum);
1108         if (ret <= 0) {
1109                 pr_debug("not prepared to track yet or error occurred\n");
1110                 NF_CT_STAT_INC_ATOMIC(net, error);
1111                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1112                 ret = -ret;
1113                 goto out;
1114         }
1115
1116         l4proto = __nf_ct_l4proto_find(pf, protonum);
1117
1118         /* It may be an special packet, error, unclean...
1119          * inverse of the return code tells to the netfilter
1120          * core what to do with the packet. */
1121         if (l4proto->error != NULL) {
1122                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1123                                      pf, hooknum);
1124                 if (ret <= 0) {
1125                         NF_CT_STAT_INC_ATOMIC(net, error);
1126                         NF_CT_STAT_INC_ATOMIC(net, invalid);
1127                         ret = -ret;
1128                         goto out;
1129                 }
1130                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1131                 if (skb->nfct)
1132                         goto out;
1133         }
1134
1135         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1136                                l3proto, l4proto, &set_reply, &ctinfo);
1137         if (!ct) {
1138                 /* Not valid part of a connection */
1139                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1140                 ret = NF_ACCEPT;
1141                 goto out;
1142         }
1143
1144         if (IS_ERR(ct)) {
1145                 /* Too stressed to deal. */
1146                 NF_CT_STAT_INC_ATOMIC(net, drop);
1147                 ret = NF_DROP;
1148                 goto out;
1149         }
1150
1151         NF_CT_ASSERT(skb->nfct);
1152
1153         /* Decide what timeout policy we want to apply to this flow. */
1154         timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1155
1156         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1157         if (ret <= 0) {
1158                 /* Invalid: inverse of the return code tells
1159                  * the netfilter core what to do */
1160                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1161                 nf_conntrack_put(skb->nfct);
1162                 skb->nfct = NULL;
1163                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1164                 if (ret == -NF_DROP)
1165                         NF_CT_STAT_INC_ATOMIC(net, drop);
1166                 ret = -ret;
1167                 goto out;
1168         }
1169
1170         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1171                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1172 out:
1173         if (tmpl) {
1174                 /* Special case: we have to repeat this hook, assign the
1175                  * template again to this packet. We assume that this packet
1176                  * has no conntrack assigned. This is used by nf_ct_tcp. */
1177                 if (ret == NF_REPEAT)
1178                         skb->nfct = (struct nf_conntrack *)tmpl;
1179                 else
1180                         nf_ct_put(tmpl);
1181         }
1182
1183         return ret;
1184 }
1185 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1186
1187 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1188                           const struct nf_conntrack_tuple *orig)
1189 {
1190         bool ret;
1191
1192         rcu_read_lock();
1193         ret = nf_ct_invert_tuple(inverse, orig,
1194                                  __nf_ct_l3proto_find(orig->src.l3num),
1195                                  __nf_ct_l4proto_find(orig->src.l3num,
1196                                                       orig->dst.protonum));
1197         rcu_read_unlock();
1198         return ret;
1199 }
1200 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1201
1202 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1203    implicitly racy: see __nf_conntrack_confirm */
1204 void nf_conntrack_alter_reply(struct nf_conn *ct,
1205                               const struct nf_conntrack_tuple *newreply)
1206 {
1207         struct nf_conn_help *help = nfct_help(ct);
1208
1209         /* Should be unconfirmed, so not in hash table yet */
1210         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1211
1212         pr_debug("Altering reply tuple of %p to ", ct);
1213         nf_ct_dump_tuple(newreply);
1214
1215         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1216         if (ct->master || (help && !hlist_empty(&help->expectations)))
1217                 return;
1218
1219         rcu_read_lock();
1220         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1221         rcu_read_unlock();
1222 }
1223 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1224
1225 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1226 void __nf_ct_refresh_acct(struct nf_conn *ct,
1227                           enum ip_conntrack_info ctinfo,
1228                           const struct sk_buff *skb,
1229                           unsigned long extra_jiffies,
1230                           int do_acct)
1231 {
1232         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1233         NF_CT_ASSERT(skb);
1234
1235         /* Only update if this is not a fixed timeout */
1236         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1237                 goto acct;
1238
1239         /* If not in hash table, timer will not be active yet */
1240         if (!nf_ct_is_confirmed(ct)) {
1241                 ct->timeout.expires = extra_jiffies;
1242         } else {
1243                 unsigned long newtime = jiffies + extra_jiffies;
1244
1245                 /* Only update the timeout if the new timeout is at least
1246                    HZ jiffies from the old timeout. Need del_timer for race
1247                    avoidance (may already be dying). */
1248                 if (newtime - ct->timeout.expires >= HZ)
1249                         mod_timer_pending(&ct->timeout, newtime);
1250         }
1251
1252 acct:
1253         if (do_acct) {
1254                 struct nf_conn_acct *acct;
1255
1256                 acct = nf_conn_acct_find(ct);
1257                 if (acct) {
1258                         struct nf_conn_counter *counter = acct->counter;
1259
1260                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1261                         atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1262                 }
1263         }
1264 }
1265 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1266
1267 bool __nf_ct_kill_acct(struct nf_conn *ct,
1268                        enum ip_conntrack_info ctinfo,
1269                        const struct sk_buff *skb,
1270                        int do_acct)
1271 {
1272         if (do_acct) {
1273                 struct nf_conn_acct *acct;
1274
1275                 acct = nf_conn_acct_find(ct);
1276                 if (acct) {
1277                         struct nf_conn_counter *counter = acct->counter;
1278
1279                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1280                         atomic64_add(skb->len - skb_network_offset(skb),
1281                                      &counter[CTINFO2DIR(ctinfo)].bytes);
1282                 }
1283         }
1284
1285         if (del_timer(&ct->timeout)) {
1286                 ct->timeout.function((unsigned long)ct);
1287                 return true;
1288         }
1289         return false;
1290 }
1291 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1292
1293 #ifdef CONFIG_NF_CONNTRACK_ZONES
1294 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1295         .len    = sizeof(struct nf_conntrack_zone),
1296         .align  = __alignof__(struct nf_conntrack_zone),
1297         .id     = NF_CT_EXT_ZONE,
1298 };
1299 #endif
1300
1301 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1302
1303 #include <linux/netfilter/nfnetlink.h>
1304 #include <linux/netfilter/nfnetlink_conntrack.h>
1305 #include <linux/mutex.h>
1306
1307 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1308  * in ip_conntrack_core, since we don't want the protocols to autoload
1309  * or depend on ctnetlink */
1310 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1311                                const struct nf_conntrack_tuple *tuple)
1312 {
1313         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1314             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1315                 goto nla_put_failure;
1316         return 0;
1317
1318 nla_put_failure:
1319         return -1;
1320 }
1321 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1322
1323 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1324         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1325         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1326 };
1327 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1328
1329 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1330                                struct nf_conntrack_tuple *t)
1331 {
1332         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1333                 return -EINVAL;
1334
1335         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1336         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1337
1338         return 0;
1339 }
1340 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1341
1342 int nf_ct_port_nlattr_tuple_size(void)
1343 {
1344         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1345 }
1346 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1347 #endif
1348
1349 /* Used by ipt_REJECT and ip6t_REJECT. */
1350 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1351 {
1352         struct nf_conn *ct;
1353         enum ip_conntrack_info ctinfo;
1354
1355         /* This ICMP is in reverse direction to the packet which caused it */
1356         ct = nf_ct_get(skb, &ctinfo);
1357         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1358                 ctinfo = IP_CT_RELATED_REPLY;
1359         else
1360                 ctinfo = IP_CT_RELATED;
1361
1362         /* Attach to new skbuff, and increment count */
1363         nskb->nfct = &ct->ct_general;
1364         nskb->nfctinfo = ctinfo;
1365         nf_conntrack_get(nskb->nfct);
1366 }
1367
1368 /* Bring out ya dead! */
1369 static struct nf_conn *
1370 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1371                 void *data, unsigned int *bucket)
1372 {
1373         struct nf_conntrack_tuple_hash *h;
1374         struct nf_conn *ct;
1375         struct hlist_nulls_node *n;
1376         int cpu;
1377         spinlock_t *lockp;
1378
1379         for (; *bucket < net->ct.htable_size; (*bucket)++) {
1380                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1381                 local_bh_disable();
1382                 spin_lock(lockp);
1383                 if (*bucket < net->ct.htable_size) {
1384                         hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1385                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1386                                         continue;
1387                                 ct = nf_ct_tuplehash_to_ctrack(h);
1388                                 if (iter(ct, data))
1389                                         goto found;
1390                         }
1391                 }
1392                 spin_unlock(lockp);
1393                 local_bh_enable();
1394         }
1395
1396         for_each_possible_cpu(cpu) {
1397                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1398
1399                 spin_lock_bh(&pcpu->lock);
1400                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1401                         ct = nf_ct_tuplehash_to_ctrack(h);
1402                         if (iter(ct, data))
1403                                 set_bit(IPS_DYING_BIT, &ct->status);
1404                 }
1405                 spin_unlock_bh(&pcpu->lock);
1406         }
1407         return NULL;
1408 found:
1409         atomic_inc(&ct->ct_general.use);
1410         spin_unlock(lockp);
1411         local_bh_enable();
1412         return ct;
1413 }
1414
1415 void nf_ct_iterate_cleanup(struct net *net,
1416                            int (*iter)(struct nf_conn *i, void *data),
1417                            void *data, u32 portid, int report)
1418 {
1419         struct nf_conn *ct;
1420         unsigned int bucket = 0;
1421
1422         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1423                 /* Time to push up daises... */
1424                 if (del_timer(&ct->timeout))
1425                         nf_ct_delete(ct, portid, report);
1426
1427                 /* ... else the timer will get him soon. */
1428
1429                 nf_ct_put(ct);
1430         }
1431 }
1432 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1433
1434 static int kill_all(struct nf_conn *i, void *data)
1435 {
1436         return 1;
1437 }
1438
1439 void nf_ct_free_hashtable(void *hash, unsigned int size)
1440 {
1441         if (is_vmalloc_addr(hash))
1442                 vfree(hash);
1443         else
1444                 free_pages((unsigned long)hash,
1445                            get_order(sizeof(struct hlist_head) * size));
1446 }
1447 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1448
1449 static int untrack_refs(void)
1450 {
1451         int cnt = 0, cpu;
1452
1453         for_each_possible_cpu(cpu) {
1454                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1455
1456                 cnt += atomic_read(&ct->ct_general.use) - 1;
1457         }
1458         return cnt;
1459 }
1460
1461 void nf_conntrack_cleanup_start(void)
1462 {
1463         RCU_INIT_POINTER(ip_ct_attach, NULL);
1464 }
1465
1466 void nf_conntrack_cleanup_end(void)
1467 {
1468         RCU_INIT_POINTER(nf_ct_destroy, NULL);
1469         while (untrack_refs() > 0)
1470                 schedule();
1471
1472 #ifdef CONFIG_NF_CONNTRACK_ZONES
1473         nf_ct_extend_unregister(&nf_ct_zone_extend);
1474 #endif
1475         nf_conntrack_proto_fini();
1476         nf_conntrack_seqadj_fini();
1477         nf_conntrack_labels_fini();
1478         nf_conntrack_helper_fini();
1479         nf_conntrack_timeout_fini();
1480         nf_conntrack_ecache_fini();
1481         nf_conntrack_tstamp_fini();
1482         nf_conntrack_acct_fini();
1483         nf_conntrack_expect_fini();
1484 }
1485
1486 /*
1487  * Mishearing the voices in his head, our hero wonders how he's
1488  * supposed to kill the mall.
1489  */
1490 void nf_conntrack_cleanup_net(struct net *net)
1491 {
1492         LIST_HEAD(single);
1493
1494         list_add(&net->exit_list, &single);
1495         nf_conntrack_cleanup_net_list(&single);
1496 }
1497
1498 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1499 {
1500         int busy;
1501         struct net *net;
1502
1503         /*
1504          * This makes sure all current packets have passed through
1505          *  netfilter framework.  Roll on, two-stage module
1506          *  delete...
1507          */
1508         synchronize_net();
1509 i_see_dead_people:
1510         busy = 0;
1511         list_for_each_entry(net, net_exit_list, exit_list) {
1512                 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1513                 if (atomic_read(&net->ct.count) != 0)
1514                         busy = 1;
1515         }
1516         if (busy) {
1517                 schedule();
1518                 goto i_see_dead_people;
1519         }
1520
1521         list_for_each_entry(net, net_exit_list, exit_list) {
1522                 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1523                 nf_conntrack_proto_pernet_fini(net);
1524                 nf_conntrack_helper_pernet_fini(net);
1525                 nf_conntrack_ecache_pernet_fini(net);
1526                 nf_conntrack_tstamp_pernet_fini(net);
1527                 nf_conntrack_acct_pernet_fini(net);
1528                 nf_conntrack_expect_pernet_fini(net);
1529                 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1530                 kfree(net->ct.slabname);
1531                 free_percpu(net->ct.stat);
1532                 free_percpu(net->ct.pcpu_lists);
1533         }
1534 }
1535
1536 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1537 {
1538         struct hlist_nulls_head *hash;
1539         unsigned int nr_slots, i;
1540         size_t sz;
1541
1542         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1543         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1544         sz = nr_slots * sizeof(struct hlist_nulls_head);
1545         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1546                                         get_order(sz));
1547         if (!hash) {
1548                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1549                 hash = vzalloc(sz);
1550         }
1551
1552         if (hash && nulls)
1553                 for (i = 0; i < nr_slots; i++)
1554                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1555
1556         return hash;
1557 }
1558 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1559
1560 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1561 {
1562         int i, bucket, rc;
1563         unsigned int hashsize, old_size;
1564         struct hlist_nulls_head *hash, *old_hash;
1565         struct nf_conntrack_tuple_hash *h;
1566         struct nf_conn *ct;
1567
1568         if (current->nsproxy->net_ns != &init_net)
1569                 return -EOPNOTSUPP;
1570
1571         /* On boot, we can set this without any fancy locking. */
1572         if (!nf_conntrack_htable_size)
1573                 return param_set_uint(val, kp);
1574
1575         rc = kstrtouint(val, 0, &hashsize);
1576         if (rc)
1577                 return rc;
1578         if (!hashsize)
1579                 return -EINVAL;
1580
1581         hash = nf_ct_alloc_hashtable(&hashsize, 1);
1582         if (!hash)
1583                 return -ENOMEM;
1584
1585         local_bh_disable();
1586         nf_conntrack_all_lock();
1587         write_seqcount_begin(&init_net.ct.generation);
1588
1589         /* Lookups in the old hash might happen in parallel, which means we
1590          * might get false negatives during connection lookup. New connections
1591          * created because of a false negative won't make it into the hash
1592          * though since that required taking the locks.
1593          */
1594
1595         for (i = 0; i < init_net.ct.htable_size; i++) {
1596                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1597                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1598                                         struct nf_conntrack_tuple_hash, hnnode);
1599                         ct = nf_ct_tuplehash_to_ctrack(h);
1600                         hlist_nulls_del_rcu(&h->hnnode);
1601                         bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1602                                                   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 }