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 ((u64)hash * size) >> 32;
 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 static void
 291 destroy_conntrack(struct nf_conntrack *nfct)
 292 {
 293         struct nf_conn *ct = (struct nf_conn *)nfct;
 294         struct net *net = nf_ct_net(ct);
 295         struct nf_conntrack_l4proto *l4proto;
 296
 297         pr_debug("destroy_conntrack(%p)\n", ct);
 298         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 299         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 300
 301         rcu_read_lock();
 302         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
 303         if (l4proto && l4proto->destroy)
 304                 l4proto->destroy(ct);
 305
 306         rcu_read_unlock();
 307
 308         local_bh_disable();
 309         /* Expectations will have been removed in clean_from_lists,
 310          * except TFTP can create an expectation on the first packet,
 311          * before connection is in the list, so we need to clean here,
 312          * too.
 313          */
 314         nf_ct_remove_expectations(ct);
 315
 316         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 317
 318         NF_CT_STAT_INC(net, delete);
 319         local_bh_enable();
 320
 321         if (ct->master)
 322                 nf_ct_put(ct->master);
 323
 324         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 325         nf_conntrack_free(ct);
 326 }
 327
 328 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 329 {
 330         struct net *net = nf_ct_net(ct);
 331         unsigned int hash, reply_hash;
 332         u16 zone = nf_ct_zone(ct);
 333         unsigned int sequence;
 334
 335         nf_ct_helper_destroy(ct);
 336
 337         local_bh_disable();
 338         do {
 339                 sequence = read_seqcount_begin(&net->ct.generation);
 340                 hash = hash_conntrack(net, zone,
 341                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 342                 reply_hash = hash_conntrack(net, zone,
 343                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 344         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 345
 346         clean_from_lists(ct);
 347         nf_conntrack_double_unlock(hash, reply_hash);
 348
 349         nf_ct_add_to_dying_list(ct);
 350
 351         NF_CT_STAT_INC(net, delete_list);
 352         local_bh_enable();
 353 }
 354
 355 static void death_by_event(unsigned long ul_conntrack)
 356 {
 357         struct nf_conn *ct = (void *)ul_conntrack;
 358         struct net *net = nf_ct_net(ct);
 359         struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
 360
 361         BUG_ON(ecache == NULL);
 362
 363         if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
 364                 /* bad luck, let's retry again */
 365                 ecache->timeout.expires = jiffies +
 366                         (prandom_u32() % net->ct.sysctl_events_retry_timeout);
 367                 add_timer(&ecache->timeout);
 368                 return;
 369         }
 370         /* we've got the event delivered, now it's dying */
 371         set_bit(IPS_DYING_BIT, &ct->status);
 372         nf_ct_put(ct);
 373 }
 374
 375 static void nf_ct_dying_timeout(struct nf_conn *ct)
 376 {
 377         struct net *net = nf_ct_net(ct);
 378         struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
 379
 380         BUG_ON(ecache == NULL);
 381
 382         /* set a new timer to retry event delivery */
 383         setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
 384         ecache->timeout.expires = jiffies +
 385                 (prandom_u32() % net->ct.sysctl_events_retry_timeout);
 386         add_timer(&ecache->timeout);
 387 }
 388
 389 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 390 {
 391         struct nf_conn_tstamp *tstamp;
 392
 393         tstamp = nf_conn_tstamp_find(ct);
 394         if (tstamp && tstamp->stop == 0)
 395                 tstamp->stop = ktime_to_ns(ktime_get_real());
 396
 397         if (!nf_ct_is_dying(ct) &&
 398             unlikely(nf_conntrack_event_report(IPCT_DESTROY, ct,
 399             portid, report) < 0)) {
 400                 /* destroy event was not delivered */
 401                 nf_ct_delete_from_lists(ct);
 402                 nf_ct_dying_timeout(ct);
 403                 return false;
 404         }
 405         set_bit(IPS_DYING_BIT, &ct->status);
 406         nf_ct_delete_from_lists(ct);
 407         nf_ct_put(ct);
 408         return true;
 409 }
 410 EXPORT_SYMBOL_GPL(nf_ct_delete);
 411
 412 static void death_by_timeout(unsigned long ul_conntrack)
 413 {
 414         nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
 415 }
 416
 417 static inline bool
 418 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 419                         const struct nf_conntrack_tuple *tuple,
 420                         u16 zone)
 421 {
 422         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 423
 424         /* A conntrack can be recreated with the equal tuple,
 425          * so we need to check that the conntrack is confirmed
 426          */
 427         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 428                 nf_ct_zone(ct) == zone &&
 429                 nf_ct_is_confirmed(ct);
 430 }
 431
 432 /*
 433  * Warning :
 434  * - Caller must take a reference on returned object
 435  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 436  */
 437 static struct nf_conntrack_tuple_hash *
 438 ____nf_conntrack_find(struct net *net, u16 zone,
 439                       const struct nf_conntrack_tuple *tuple, u32 hash)
 440 {
 441         struct nf_conntrack_tuple_hash *h;
 442         struct hlist_nulls_node *n;
 443         unsigned int bucket = hash_bucket(hash, net);
 444
 445         /* Disable BHs the entire time since we normally need to disable them
 446          * at least once for the stats anyway.
 447          */
 448         local_bh_disable();
 449 begin:
 450         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
 451                 if (nf_ct_key_equal(h, tuple, zone)) {
 452                         NF_CT_STAT_INC(net, found);
 453                         local_bh_enable();
 454                         return h;
 455                 }
 456                 NF_CT_STAT_INC(net, searched);
 457         }
 458         /*
 459          * if the nulls value we got at the end of this lookup is
 460          * not the expected one, we must restart lookup.
 461          * We probably met an item that was moved to another chain.
 462          */
 463         if (get_nulls_value(n) != bucket) {
 464                 NF_CT_STAT_INC(net, search_restart);
 465                 goto begin;
 466         }
 467         local_bh_enable();
 468
 469         return NULL;
 470 }
 471
 472 /* Find a connection corresponding to a tuple. */
 473 static struct nf_conntrack_tuple_hash *
 474 __nf_conntrack_find_get(struct net *net, u16 zone,
 475                         const struct nf_conntrack_tuple *tuple, u32 hash)
 476 {
 477         struct nf_conntrack_tuple_hash *h;
 478         struct nf_conn *ct;
 479
 480         rcu_read_lock();
 481 begin:
 482         h = ____nf_conntrack_find(net, zone, tuple, hash);
 483         if (h) {
 484                 ct = nf_ct_tuplehash_to_ctrack(h);
 485                 if (unlikely(nf_ct_is_dying(ct) ||
 486                              !atomic_inc_not_zero(&ct->ct_general.use)))
 487                         h = NULL;
 488                 else {
 489                         if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
 490                                 nf_ct_put(ct);
 491                                 goto begin;
 492                         }
 493                 }
 494         }
 495         rcu_read_unlock();
 496
 497         return h;
 498 }
 499
 500 struct nf_conntrack_tuple_hash *
 501 nf_conntrack_find_get(struct net *net, u16 zone,
 502                       const struct nf_conntrack_tuple *tuple)
 503 {
 504         return __nf_conntrack_find_get(net, zone, tuple,
 505                                        hash_conntrack_raw(tuple, zone));
 506 }
 507 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 508
 509 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 510                                        unsigned int hash,
 511                                        unsigned int reply_hash)
 512 {
 513         struct net *net = nf_ct_net(ct);
 514
 515         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 516                            &net->ct.hash[hash]);
 517         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 518                            &net->ct.hash[reply_hash]);
 519 }
 520
 521 int
 522 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 523 {
 524         struct net *net = nf_ct_net(ct);
 525         unsigned int hash, reply_hash;
 526         struct nf_conntrack_tuple_hash *h;
 527         struct hlist_nulls_node *n;
 528         u16 zone;
 529         unsigned int sequence;
 530
 531         zone = nf_ct_zone(ct);
 532
 533         local_bh_disable();
 534         do {
 535                 sequence = read_seqcount_begin(&net->ct.generation);
 536                 hash = hash_conntrack(net, zone,
 537                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 538                 reply_hash = hash_conntrack(net, zone,
 539                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 540         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 541
 542         /* See if there's one in the list already, including reverse */
 543         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 544                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 545                                       &h->tuple) &&
 546                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 547                         goto out;
 548         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 549                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 550                                       &h->tuple) &&
 551                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 552                         goto out;
 553
 554         add_timer(&ct->timeout);
 555         smp_wmb();
 556         /* The caller holds a reference to this object */
 557         atomic_set(&ct->ct_general.use, 2);
 558         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 559         nf_conntrack_double_unlock(hash, reply_hash);
 560         NF_CT_STAT_INC(net, insert);
 561         local_bh_enable();
 562         return 0;
 563
 564 out:
 565         nf_conntrack_double_unlock(hash, reply_hash);
 566         NF_CT_STAT_INC(net, insert_failed);
 567         local_bh_enable();
 568         return -EEXIST;
 569 }
 570 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 571
 572 /* deletion from this larval template list happens via nf_ct_put() */
 573 void nf_conntrack_tmpl_insert(struct net *net, struct nf_conn *tmpl)
 574 {
 575         struct ct_pcpu *pcpu;
 576
 577         __set_bit(IPS_TEMPLATE_BIT, &tmpl->status);
 578         __set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
 579         nf_conntrack_get(&tmpl->ct_general);
 580
 581         /* add this conntrack to the (per cpu) tmpl list */
 582         local_bh_disable();
 583         tmpl->cpu = smp_processor_id();
 584         pcpu = per_cpu_ptr(nf_ct_net(tmpl)->ct.pcpu_lists, tmpl->cpu);
 585
 586         spin_lock(&pcpu->lock);
 587         /* Overload tuple linked list to put us in template list. */
 588         hlist_nulls_add_head_rcu(&tmpl->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 589                                  &pcpu->tmpl);
 590         spin_unlock_bh(&pcpu->lock);
 591 }
 592 EXPORT_SYMBOL_GPL(nf_conntrack_tmpl_insert);
 593
 594 /* Confirm a connection given skb; places it in hash table */
 595 int
 596 __nf_conntrack_confirm(struct sk_buff *skb)
 597 {
 598         unsigned int hash, reply_hash;
 599         struct nf_conntrack_tuple_hash *h;
 600         struct nf_conn *ct;
 601         struct nf_conn_help *help;
 602         struct nf_conn_tstamp *tstamp;
 603         struct hlist_nulls_node *n;
 604         enum ip_conntrack_info ctinfo;
 605         struct net *net;
 606         u16 zone;
 607         unsigned int sequence;
 608
 609         ct = nf_ct_get(skb, &ctinfo);
 610         net = nf_ct_net(ct);
 611
 612         /* ipt_REJECT uses nf_conntrack_attach to attach related
 613            ICMP/TCP RST packets in other direction.  Actual packet
 614            which created connection will be IP_CT_NEW or for an
 615            expected connection, IP_CT_RELATED. */
 616         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 617                 return NF_ACCEPT;
 618
 619         zone = nf_ct_zone(ct);
 620         local_bh_disable();
 621
 622         do {
 623                 sequence = read_seqcount_begin(&net->ct.generation);
 624                 /* reuse the hash saved before */
 625                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 626                 hash = hash_bucket(hash, net);
 627                 reply_hash = hash_conntrack(net, zone,
 628                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 629
 630         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 631
 632         /* We're not in hash table, and we refuse to set up related
 633          * connections for unconfirmed conns.  But packet copies and
 634          * REJECT will give spurious warnings here.
 635          */
 636         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 637
 638         /* No external references means no one else could have
 639          * confirmed us.
 640          */
 641         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 642         pr_debug("Confirming conntrack %p\n", ct);
 643         /* We have to check the DYING flag inside the lock to prevent
 644            a race against nf_ct_get_next_corpse() possibly called from
 645            user context, else we insert an already 'dead' hash, blocking
 646            further use of that particular connection -JM */
 647
 648         if (unlikely(nf_ct_is_dying(ct))) {
 649                 nf_conntrack_double_unlock(hash, reply_hash);
 650                 local_bh_enable();
 651                 return NF_ACCEPT;
 652         }
 653
 654         /* See if there's one in the list already, including reverse:
 655            NAT could have grabbed it without realizing, since we're
 656            not in the hash.  If there is, we lost race. */
 657         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 658                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 659                                       &h->tuple) &&
 660                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 661                         goto out;
 662         hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 663                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 664                                       &h->tuple) &&
 665                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
 666                         goto out;
 667
 668         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 669
 670         /* Timer relative to confirmation time, not original
 671            setting time, otherwise we'd get timer wrap in
 672            weird delay cases. */
 673         ct->timeout.expires += jiffies;
 674         add_timer(&ct->timeout);
 675         atomic_inc(&ct->ct_general.use);
 676         ct->status |= IPS_CONFIRMED;
 677
 678         /* set conntrack timestamp, if enabled. */
 679         tstamp = nf_conn_tstamp_find(ct);
 680         if (tstamp) {
 681                 if (skb->tstamp.tv64 == 0)
 682                         __net_timestamp(skb);
 683
 684                 tstamp->start = ktime_to_ns(skb->tstamp);
 685         }
 686         /* Since the lookup is lockless, hash insertion must be done after
 687          * starting the timer and setting the CONFIRMED bit. The RCU barriers
 688          * guarantee that no other CPU can find the conntrack before the above
 689          * stores are visible.
 690          */
 691         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 692         nf_conntrack_double_unlock(hash, reply_hash);
 693         NF_CT_STAT_INC(net, insert);
 694         local_bh_enable();
 695
 696         help = nfct_help(ct);
 697         if (help && help->helper)
 698                 nf_conntrack_event_cache(IPCT_HELPER, ct);
 699
 700         nf_conntrack_event_cache(master_ct(ct) ?
 701                                  IPCT_RELATED : IPCT_NEW, ct);
 702         return NF_ACCEPT;
 703
 704 out:
 705         nf_conntrack_double_unlock(hash, reply_hash);
 706         NF_CT_STAT_INC(net, insert_failed);
 707         local_bh_enable();
 708         return NF_DROP;
 709 }
 710 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 711
 712 /* Returns true if a connection correspondings to the tuple (required
 713    for NAT). */
 714 int
 715 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 716                          const struct nf_conn *ignored_conntrack)
 717 {
 718         struct net *net = nf_ct_net(ignored_conntrack);
 719         struct nf_conntrack_tuple_hash *h;
 720         struct hlist_nulls_node *n;
 721         struct nf_conn *ct;
 722         u16 zone = nf_ct_zone(ignored_conntrack);
 723         unsigned int hash = hash_conntrack(net, zone, tuple);
 724
 725         /* Disable BHs the entire time since we need to disable them at
 726          * least once for the stats anyway.
 727          */
 728         rcu_read_lock_bh();
 729         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
 730                 ct = nf_ct_tuplehash_to_ctrack(h);
 731                 if (ct != ignored_conntrack &&
 732                     nf_ct_tuple_equal(tuple, &h->tuple) &&
 733                     nf_ct_zone(ct) == zone) {
 734                         NF_CT_STAT_INC(net, found);
 735                         rcu_read_unlock_bh();
 736                         return 1;
 737                 }
 738                 NF_CT_STAT_INC(net, searched);
 739         }
 740         rcu_read_unlock_bh();
 741
 742         return 0;
 743 }
 744 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
 745
 746 #define NF_CT_EVICTION_RANGE    8
 747
 748 /* There's a small race here where we may free a just-assured
 749    connection.  Too bad: we're in trouble anyway. */
 750 static noinline int early_drop(struct net *net, unsigned int _hash)
 751 {
 752         /* Use oldest entry, which is roughly LRU */
 753         struct nf_conntrack_tuple_hash *h;
 754         struct nf_conn *ct = NULL, *tmp;
 755         struct hlist_nulls_node *n;
 756         unsigned int i = 0, cnt = 0;
 757         int dropped = 0;
 758         unsigned int hash, sequence;
 759         spinlock_t *lockp;
 760
 761         local_bh_disable();
 762 restart:
 763         sequence = read_seqcount_begin(&net->ct.generation);
 764         hash = hash_bucket(_hash, net);
 765         for (; i < net->ct.htable_size; i++) {
 766                 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
 767                 spin_lock(lockp);
 768                 if (read_seqcount_retry(&net->ct.generation, sequence)) {
 769                         spin_unlock(lockp);
 770                         goto restart;
 771                 }
 772                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
 773                                          hnnode) {
 774                         tmp = nf_ct_tuplehash_to_ctrack(h);
 775                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
 776                             !nf_ct_is_dying(tmp) &&
 777                             atomic_inc_not_zero(&tmp->ct_general.use)) {
 778                                 ct = tmp;
 779                                 break;
 780                         }
 781                         cnt++;
 782                 }
 783
 784                 hash = (hash + 1) % net->ct.htable_size;
 785                 spin_unlock(lockp);
 786
 787                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
 788                         break;
 789
 790         }
 791         local_bh_enable();
 792
 793         if (!ct)
 794                 return dropped;
 795
 796         if (del_timer(&ct->timeout)) {
 797                 if (nf_ct_delete(ct, 0, 0)) {
 798                         dropped = 1;
 799                         NF_CT_STAT_INC_ATOMIC(net, early_drop);
 800                 }
 801         }
 802         nf_ct_put(ct);
 803         return dropped;
 804 }
 805
 806 void init_nf_conntrack_hash_rnd(void)
 807 {
 808         unsigned int rand;
 809
 810         /*
 811          * Why not initialize nf_conntrack_rnd in a "init()" function ?
 812          * Because there isn't enough entropy when system initializing,
 813          * and we initialize it as late as possible.
 814          */
 815         do {
 816                 get_random_bytes(&rand, sizeof(rand));
 817         } while (!rand);
 818         cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
 819 }
 820
 821 static struct nf_conn *
 822 __nf_conntrack_alloc(struct net *net, u16 zone,
 823                      const struct nf_conntrack_tuple *orig,
 824                      const struct nf_conntrack_tuple *repl,
 825                      gfp_t gfp, u32 hash)
 826 {
 827         struct nf_conn *ct;
 828
 829         if (unlikely(!nf_conntrack_hash_rnd)) {
 830                 init_nf_conntrack_hash_rnd();
 831                 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
 832                 hash = hash_conntrack_raw(orig, zone);
 833         }
 834
 835         /* We don't want any race condition at early drop stage */
 836         atomic_inc(&net->ct.count);
 837
 838         if (nf_conntrack_max &&
 839             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
 840                 if (!early_drop(net, hash)) {
 841                         atomic_dec(&net->ct.count);
 842                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
 843                         return ERR_PTR(-ENOMEM);
 844                 }
 845         }
 846
 847         /*
 848          * Do not use kmem_cache_zalloc(), as this cache uses
 849          * SLAB_DESTROY_BY_RCU.
 850          */
 851         ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
 852         if (ct == NULL) {
 853                 atomic_dec(&net->ct.count);
 854                 return ERR_PTR(-ENOMEM);
 855         }
 856         /*
 857          * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
 858          * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
 859          */
 860         memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
 861                offsetof(struct nf_conn, proto) -
 862                offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
 863         spin_lock_init(&ct->lock);
 864         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 865         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
 866         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 867         /* save hash for reusing when confirming */
 868         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
 869         /* Don't set timer yet: wait for confirmation */
 870         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
 871         write_pnet(&ct->ct_net, net);
 872 #ifdef CONFIG_NF_CONNTRACK_ZONES
 873         if (zone) {
 874                 struct nf_conntrack_zone *nf_ct_zone;
 875
 876                 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
 877                 if (!nf_ct_zone)
 878                         goto out_free;
 879                 nf_ct_zone->id = zone;
 880         }
 881 #endif
 882         /* Because we use RCU lookups, we set ct_general.use to zero before
 883          * this is inserted in any list.
 884          */
 885         atomic_set(&ct->ct_general.use, 0);
 886         return ct;
 887
 888 #ifdef CONFIG_NF_CONNTRACK_ZONES
 889 out_free:
 890         atomic_dec(&net->ct.count);
 891         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 892         return ERR_PTR(-ENOMEM);
 893 #endif
 894 }
 895
 896 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
 897                                    const struct nf_conntrack_tuple *orig,
 898                                    const struct nf_conntrack_tuple *repl,
 899                                    gfp_t gfp)
 900 {
 901         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
 902 }
 903 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
 904
 905 void nf_conntrack_free(struct nf_conn *ct)
 906 {
 907         struct net *net = nf_ct_net(ct);
 908
 909         /* A freed object has refcnt == 0, that's
 910          * the golden rule for SLAB_DESTROY_BY_RCU
 911          */
 912         NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
 913
 914         nf_ct_ext_destroy(ct);
 915         nf_ct_ext_free(ct);
 916         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
 917         smp_mb__before_atomic_dec();
 918         atomic_dec(&net->ct.count);
 919 }
 920 EXPORT_SYMBOL_GPL(nf_conntrack_free);
 921
 922
 923 /* Allocate a new conntrack: we return -ENOMEM if classification
 924    failed due to stress.  Otherwise it really is unclassifiable. */
 925 static struct nf_conntrack_tuple_hash *
 926 init_conntrack(struct net *net, struct nf_conn *tmpl,
 927                const struct nf_conntrack_tuple *tuple,
 928                struct nf_conntrack_l3proto *l3proto,
 929                struct nf_conntrack_l4proto *l4proto,
 930                struct sk_buff *skb,
 931                unsigned int dataoff, u32 hash)
 932 {
 933         struct nf_conn *ct;
 934         struct nf_conn_help *help;
 935         struct nf_conntrack_tuple repl_tuple;
 936         struct nf_conntrack_ecache *ecache;
 937         struct nf_conntrack_expect *exp = NULL;
 938         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
 939         struct nf_conn_timeout *timeout_ext;
 940         unsigned int *timeouts;
 941
 942         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 943                 pr_debug("Can't invert tuple.\n");
 944                 return NULL;
 945         }
 946
 947         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 948                                   hash);
 949         if (IS_ERR(ct))
 950                 return (struct nf_conntrack_tuple_hash *)ct;
 951
 952         if (tmpl && nfct_synproxy(tmpl)) {
 953                 nfct_seqadj_ext_add(ct);
 954                 nfct_synproxy_ext_add(ct);
 955         }
 956
 957         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
 958         if (timeout_ext)
 959                 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
 960         else
 961                 timeouts = l4proto->get_timeouts(net);
 962
 963         if (!l4proto->new(ct, skb, dataoff, timeouts)) {
 964                 nf_conntrack_free(ct);
 965                 pr_debug("init conntrack: can't track with proto module\n");
 966                 return NULL;
 967         }
 968
 969         if (timeout_ext)
 970                 nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);
 971
 972         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
 973         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
 974         nf_ct_labels_ext_add(ct);
 975
 976         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
 977         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
 978                                  ecache ? ecache->expmask : 0,
 979                              GFP_ATOMIC);
 980
 981         local_bh_disable();
 982         if (net->ct.expect_count) {
 983                 spin_lock(&nf_conntrack_expect_lock);
 984                 exp = nf_ct_find_expectation(net, zone, tuple);
 985                 if (exp) {
 986                         pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
 987                                  ct, exp);
 988                         /* Welcome, Mr. Bond.  We've been expecting you... */
 989                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
 990                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
 991                         ct->master = exp->master;
 992                         if (exp->helper) {
 993                                 help = nf_ct_helper_ext_add(ct, exp->helper,
 994                                                             GFP_ATOMIC);
 995                                 if (help)
 996                                         rcu_assign_pointer(help->helper, exp->helper);
 997                         }
 998
 999 #ifdef CONFIG_NF_CONNTRACK_MARK
1000                         ct->mark = exp->master->mark;
1001 #endif
1002 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1003                         ct->secmark = exp->master->secmark;
1004 #endif
1005                         NF_CT_STAT_INC(net, expect_new);
1006                 }
1007                 spin_unlock(&nf_conntrack_expect_lock);
1008         }
1009         if (!exp) {
1010                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1011                 NF_CT_STAT_INC(net, new);
1012         }
1013
1014         /* Now it is inserted into the unconfirmed list, bump refcount */
1015         nf_conntrack_get(&ct->ct_general);
1016         nf_ct_add_to_unconfirmed_list(ct);
1017
1018         local_bh_enable();
1019
1020         if (exp) {
1021                 if (exp->expectfn)
1022                         exp->expectfn(ct, exp);
1023                 nf_ct_expect_put(exp);
1024         }
1025
1026         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1027 }
1028
1029 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1030 static inline struct nf_conn *
1031 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1032                   struct sk_buff *skb,
1033                   unsigned int dataoff,
1034                   u_int16_t l3num,
1035                   u_int8_t protonum,
1036                   struct nf_conntrack_l3proto *l3proto,
1037                   struct nf_conntrack_l4proto *l4proto,
1038                   int *set_reply,
1039                   enum ip_conntrack_info *ctinfo)
1040 {
1041         struct nf_conntrack_tuple tuple;
1042         struct nf_conntrack_tuple_hash *h;
1043         struct nf_conn *ct;
1044         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
1045         u32 hash;
1046
1047         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1048                              dataoff, l3num, protonum, &tuple, l3proto,
1049                              l4proto)) {
1050                 pr_debug("resolve_normal_ct: Can't get tuple\n");
1051                 return NULL;
1052         }
1053
1054         /* look for tuple match */
1055         hash = hash_conntrack_raw(&tuple, zone);
1056         h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1057         if (!h) {
1058                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1059                                    skb, dataoff, hash);
1060                 if (!h)
1061                         return NULL;
1062                 if (IS_ERR(h))
1063                         return (void *)h;
1064         }
1065         ct = nf_ct_tuplehash_to_ctrack(h);
1066
1067         /* It exists; we have (non-exclusive) reference. */
1068         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1069                 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1070                 /* Please set reply bit if this packet OK */
1071                 *set_reply = 1;
1072         } else {
1073                 /* Once we've had two way comms, always ESTABLISHED. */
1074                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1075                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1076                         *ctinfo = IP_CT_ESTABLISHED;
1077                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1078                         pr_debug("nf_conntrack_in: related packet for %p\n",
1079                                  ct);
1080                         *ctinfo = IP_CT_RELATED;
1081                 } else {
1082                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1083                         *ctinfo = IP_CT_NEW;
1084                 }
1085                 *set_reply = 0;
1086         }
1087         skb->nfct = &ct->ct_general;
1088         skb->nfctinfo = *ctinfo;
1089         return ct;
1090 }
1091
1092 unsigned int
1093 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1094                 struct sk_buff *skb)
1095 {
1096         struct nf_conn *ct, *tmpl = NULL;
1097         enum ip_conntrack_info ctinfo;
1098         struct nf_conntrack_l3proto *l3proto;
1099         struct nf_conntrack_l4proto *l4proto;
1100         unsigned int *timeouts;
1101         unsigned int dataoff;
1102         u_int8_t protonum;
1103         int set_reply = 0;
1104         int ret;
1105
1106         if (skb->nfct) {
1107                 /* Previously seen (loopback or untracked)?  Ignore. */
1108                 tmpl = (struct nf_conn *)skb->nfct;
1109                 if (!nf_ct_is_template(tmpl)) {
1110                         NF_CT_STAT_INC_ATOMIC(net, ignore);
1111                         return NF_ACCEPT;
1112                 }
1113                 skb->nfct = NULL;
1114         }
1115
1116         /* rcu_read_lock()ed by nf_hook_slow */
1117         l3proto = __nf_ct_l3proto_find(pf);
1118         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1119                                    &dataoff, &protonum);
1120         if (ret <= 0) {
1121                 pr_debug("not prepared to track yet or error occurred\n");
1122                 NF_CT_STAT_INC_ATOMIC(net, error);
1123                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1124                 ret = -ret;
1125                 goto out;
1126         }
1127
1128         l4proto = __nf_ct_l4proto_find(pf, protonum);
1129
1130         /* It may be an special packet, error, unclean...
1131          * inverse of the return code tells to the netfilter
1132          * core what to do with the packet. */
1133         if (l4proto->error != NULL) {
1134                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1135                                      pf, hooknum);
1136                 if (ret <= 0) {
1137                         NF_CT_STAT_INC_ATOMIC(net, error);
1138                         NF_CT_STAT_INC_ATOMIC(net, invalid);
1139                         ret = -ret;
1140                         goto out;
1141                 }
1142                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1143                 if (skb->nfct)
1144                         goto out;
1145         }
1146
1147         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1148                                l3proto, l4proto, &set_reply, &ctinfo);
1149         if (!ct) {
1150                 /* Not valid part of a connection */
1151                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1152                 ret = NF_ACCEPT;
1153                 goto out;
1154         }
1155
1156         if (IS_ERR(ct)) {
1157                 /* Too stressed to deal. */
1158                 NF_CT_STAT_INC_ATOMIC(net, drop);
1159                 ret = NF_DROP;
1160                 goto out;
1161         }
1162
1163         NF_CT_ASSERT(skb->nfct);
1164
1165         /* Decide what timeout policy we want to apply to this flow. */
1166         timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1167
1168         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1169         if (ret <= 0) {
1170                 /* Invalid: inverse of the return code tells
1171                  * the netfilter core what to do */
1172                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1173                 nf_conntrack_put(skb->nfct);
1174                 skb->nfct = NULL;
1175                 NF_CT_STAT_INC_ATOMIC(net, invalid);
1176                 if (ret == -NF_DROP)
1177                         NF_CT_STAT_INC_ATOMIC(net, drop);
1178                 ret = -ret;
1179                 goto out;
1180         }
1181
1182         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1183                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1184 out:
1185         if (tmpl) {
1186                 /* Special case: we have to repeat this hook, assign the
1187                  * template again to this packet. We assume that this packet
1188                  * has no conntrack assigned. This is used by nf_ct_tcp. */
1189                 if (ret == NF_REPEAT)
1190                         skb->nfct = (struct nf_conntrack *)tmpl;
1191                 else
1192                         nf_ct_put(tmpl);
1193         }
1194
1195         return ret;
1196 }
1197 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1198
1199 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1200                           const struct nf_conntrack_tuple *orig)
1201 {
1202         bool ret;
1203
1204         rcu_read_lock();
1205         ret = nf_ct_invert_tuple(inverse, orig,
1206                                  __nf_ct_l3proto_find(orig->src.l3num),
1207                                  __nf_ct_l4proto_find(orig->src.l3num,
1208                                                       orig->dst.protonum));
1209         rcu_read_unlock();
1210         return ret;
1211 }
1212 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1213
1214 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1215    implicitly racy: see __nf_conntrack_confirm */
1216 void nf_conntrack_alter_reply(struct nf_conn *ct,
1217                               const struct nf_conntrack_tuple *newreply)
1218 {
1219         struct nf_conn_help *help = nfct_help(ct);
1220
1221         /* Should be unconfirmed, so not in hash table yet */
1222         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1223
1224         pr_debug("Altering reply tuple of %p to ", ct);
1225         nf_ct_dump_tuple(newreply);
1226
1227         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1228         if (ct->master || (help && !hlist_empty(&help->expectations)))
1229                 return;
1230
1231         rcu_read_lock();
1232         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1233         rcu_read_unlock();
1234 }
1235 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1236
1237 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1238 void __nf_ct_refresh_acct(struct nf_conn *ct,
1239                           enum ip_conntrack_info ctinfo,
1240                           const struct sk_buff *skb,
1241                           unsigned long extra_jiffies,
1242                           int do_acct)
1243 {
1244         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1245         NF_CT_ASSERT(skb);
1246
1247         /* Only update if this is not a fixed timeout */
1248         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1249                 goto acct;
1250
1251         /* If not in hash table, timer will not be active yet */
1252         if (!nf_ct_is_confirmed(ct)) {
1253                 ct->timeout.expires = extra_jiffies;
1254         } else {
1255                 unsigned long newtime = jiffies + extra_jiffies;
1256
1257                 /* Only update the timeout if the new timeout is at least
1258                    HZ jiffies from the old timeout. Need del_timer for race
1259                    avoidance (may already be dying). */
1260                 if (newtime - ct->timeout.expires >= HZ)
1261                         mod_timer_pending(&ct->timeout, newtime);
1262         }
1263
1264 acct:
1265         if (do_acct) {
1266                 struct nf_conn_acct *acct;
1267
1268                 acct = nf_conn_acct_find(ct);
1269                 if (acct) {
1270                         struct nf_conn_counter *counter = acct->counter;
1271
1272                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1273                         atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1274                 }
1275         }
1276 }
1277 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1278
1279 bool __nf_ct_kill_acct(struct nf_conn *ct,
1280                        enum ip_conntrack_info ctinfo,
1281                        const struct sk_buff *skb,
1282                        int do_acct)
1283 {
1284         if (do_acct) {
1285                 struct nf_conn_acct *acct;
1286
1287                 acct = nf_conn_acct_find(ct);
1288                 if (acct) {
1289                         struct nf_conn_counter *counter = acct->counter;
1290
1291                         atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1292                         atomic64_add(skb->len - skb_network_offset(skb),
1293                                      &counter[CTINFO2DIR(ctinfo)].bytes);
1294                 }
1295         }
1296
1297         if (del_timer(&ct->timeout)) {
1298                 ct->timeout.function((unsigned long)ct);
1299                 return true;
1300         }
1301         return false;
1302 }
1303 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1304
1305 #ifdef CONFIG_NF_CONNTRACK_ZONES
1306 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1307         .len    = sizeof(struct nf_conntrack_zone),
1308         .align  = __alignof__(struct nf_conntrack_zone),
1309         .id     = NF_CT_EXT_ZONE,
1310 };
1311 #endif
1312
1313 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1314
1315 #include <linux/netfilter/nfnetlink.h>
1316 #include <linux/netfilter/nfnetlink_conntrack.h>
1317 #include <linux/mutex.h>
1318
1319 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1320  * in ip_conntrack_core, since we don't want the protocols to autoload
1321  * or depend on ctnetlink */
1322 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1323                                const struct nf_conntrack_tuple *tuple)
1324 {
1325         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1326             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1327                 goto nla_put_failure;
1328         return 0;
1329
1330 nla_put_failure:
1331         return -1;
1332 }
1333 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1334
1335 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1336         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1337         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1338 };
1339 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1340
1341 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1342                                struct nf_conntrack_tuple *t)
1343 {
1344         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1345                 return -EINVAL;
1346
1347         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1348         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1349
1350         return 0;
1351 }
1352 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1353
1354 int nf_ct_port_nlattr_tuple_size(void)
1355 {
1356         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1357 }
1358 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1359 #endif
1360
1361 /* Used by ipt_REJECT and ip6t_REJECT. */
1362 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1363 {
1364         struct nf_conn *ct;
1365         enum ip_conntrack_info ctinfo;
1366
1367         /* This ICMP is in reverse direction to the packet which caused it */
1368         ct = nf_ct_get(skb, &ctinfo);
1369         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1370                 ctinfo = IP_CT_RELATED_REPLY;
1371         else
1372                 ctinfo = IP_CT_RELATED;
1373
1374         /* Attach to new skbuff, and increment count */
1375         nskb->nfct = &ct->ct_general;
1376         nskb->nfctinfo = ctinfo;
1377         nf_conntrack_get(nskb->nfct);
1378 }
1379
1380 /* Bring out ya dead! */
1381 static struct nf_conn *
1382 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1383                 void *data, unsigned int *bucket)
1384 {
1385         struct nf_conntrack_tuple_hash *h;
1386         struct nf_conn *ct;
1387         struct hlist_nulls_node *n;
1388         int cpu;
1389         spinlock_t *lockp;
1390
1391         for (; *bucket < net->ct.htable_size; (*bucket)++) {
1392                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1393                 local_bh_disable();
1394                 spin_lock(lockp);
1395                 if (*bucket < net->ct.htable_size) {
1396                         hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1397                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1398                                         continue;
1399                                 ct = nf_ct_tuplehash_to_ctrack(h);
1400                                 if (iter(ct, data))
1401                                         goto found;
1402                         }
1403                 }
1404                 spin_unlock(lockp);
1405                 local_bh_enable();
1406         }
1407
1408         for_each_possible_cpu(cpu) {
1409                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1410
1411                 spin_lock_bh(&pcpu->lock);
1412                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1413                         ct = nf_ct_tuplehash_to_ctrack(h);
1414                         if (iter(ct, data))
1415                                 set_bit(IPS_DYING_BIT, &ct->status);
1416                 }
1417                 spin_unlock_bh(&pcpu->lock);
1418         }
1419         return NULL;
1420 found:
1421         atomic_inc(&ct->ct_general.use);
1422         spin_unlock(lockp);
1423         local_bh_enable();
1424         return ct;
1425 }
1426
1427 void nf_ct_iterate_cleanup(struct net *net,
1428                            int (*iter)(struct nf_conn *i, void *data),
1429                            void *data, u32 portid, int report)
1430 {
1431         struct nf_conn *ct;
1432         unsigned int bucket = 0;
1433
1434         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1435                 /* Time to push up daises... */
1436                 if (del_timer(&ct->timeout))
1437                         nf_ct_delete(ct, portid, report);
1438
1439                 /* ... else the timer will get him soon. */
1440
1441                 nf_ct_put(ct);
1442         }
1443 }
1444 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1445
1446 static int kill_all(struct nf_conn *i, void *data)
1447 {
1448         return 1;
1449 }
1450
1451 void nf_ct_free_hashtable(void *hash, unsigned int size)
1452 {
1453         if (is_vmalloc_addr(hash))
1454                 vfree(hash);
1455         else
1456                 free_pages((unsigned long)hash,
1457                            get_order(sizeof(struct hlist_head) * size));
1458 }
1459 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1460
1461 void nf_conntrack_flush_report(struct net *net, u32 portid, int report)
1462 {
1463         nf_ct_iterate_cleanup(net, kill_all, NULL, portid, report);
1464 }
1465 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1466
1467 static void nf_ct_release_dying_list(struct net *net)
1468 {
1469         struct nf_conntrack_tuple_hash *h;
1470         struct nf_conn *ct;
1471         struct hlist_nulls_node *n;
1472         int cpu;
1473
1474         for_each_possible_cpu(cpu) {
1475                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1476
1477                 spin_lock_bh(&pcpu->lock);
1478                 hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) {
1479                         ct = nf_ct_tuplehash_to_ctrack(h);
1480                         /* never fails to remove them, no listeners at this point */
1481                         nf_ct_kill(ct);
1482                 }
1483                 spin_unlock_bh(&pcpu->lock);
1484         }
1485 }
1486
1487 static int untrack_refs(void)
1488 {
1489         int cnt = 0, cpu;
1490
1491         for_each_possible_cpu(cpu) {
1492                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1493
1494                 cnt += atomic_read(&ct->ct_general.use) - 1;
1495         }
1496         return cnt;
1497 }
1498
1499 void nf_conntrack_cleanup_start(void)
1500 {
1501         RCU_INIT_POINTER(ip_ct_attach, NULL);
1502 }
1503
1504 void nf_conntrack_cleanup_end(void)
1505 {
1506         RCU_INIT_POINTER(nf_ct_destroy, NULL);
1507         while (untrack_refs() > 0)
1508                 schedule();
1509
1510 #ifdef CONFIG_NF_CONNTRACK_ZONES
1511         nf_ct_extend_unregister(&nf_ct_zone_extend);
1512 #endif
1513         nf_conntrack_proto_fini();
1514         nf_conntrack_seqadj_fini();
1515         nf_conntrack_labels_fini();
1516         nf_conntrack_helper_fini();
1517         nf_conntrack_timeout_fini();
1518         nf_conntrack_ecache_fini();
1519         nf_conntrack_tstamp_fini();
1520         nf_conntrack_acct_fini();
1521         nf_conntrack_expect_fini();
1522 }
1523
1524 /*
1525  * Mishearing the voices in his head, our hero wonders how he's
1526  * supposed to kill the mall.
1527  */
1528 void nf_conntrack_cleanup_net(struct net *net)
1529 {
1530         LIST_HEAD(single);
1531
1532         list_add(&net->exit_list, &single);
1533         nf_conntrack_cleanup_net_list(&single);
1534 }
1535
1536 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1537 {
1538         int busy;
1539         struct net *net;
1540
1541         /*
1542          * This makes sure all current packets have passed through
1543          *  netfilter framework.  Roll on, two-stage module
1544          *  delete...
1545          */
1546         synchronize_net();
1547 i_see_dead_people:
1548         busy = 0;
1549         list_for_each_entry(net, net_exit_list, exit_list) {
1550                 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1551                 nf_ct_release_dying_list(net);
1552                 if (atomic_read(&net->ct.count) != 0)
1553                         busy = 1;
1554         }
1555         if (busy) {
1556                 schedule();
1557                 goto i_see_dead_people;
1558         }
1559
1560         list_for_each_entry(net, net_exit_list, exit_list) {
1561                 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1562                 nf_conntrack_proto_pernet_fini(net);
1563                 nf_conntrack_helper_pernet_fini(net);
1564                 nf_conntrack_ecache_pernet_fini(net);
1565                 nf_conntrack_tstamp_pernet_fini(net);
1566                 nf_conntrack_acct_pernet_fini(net);
1567                 nf_conntrack_expect_pernet_fini(net);
1568                 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1569                 kfree(net->ct.slabname);
1570                 free_percpu(net->ct.stat);
1571                 free_percpu(net->ct.pcpu_lists);
1572         }
1573 }
1574
1575 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1576 {
1577         struct hlist_nulls_head *hash;
1578         unsigned int nr_slots, i;
1579         size_t sz;
1580
1581         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1582         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1583         sz = nr_slots * sizeof(struct hlist_nulls_head);
1584         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1585                                         get_order(sz));
1586         if (!hash) {
1587                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1588                 hash = vzalloc(sz);
1589         }
1590
1591         if (hash && nulls)
1592                 for (i = 0; i < nr_slots; i++)
1593                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1594
1595         return hash;
1596 }
1597 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1598
1599 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1600 {
1601         int i, bucket, rc;
1602         unsigned int hashsize, old_size;
1603         struct hlist_nulls_head *hash, *old_hash;
1604         struct nf_conntrack_tuple_hash *h;
1605         struct nf_conn *ct;
1606
1607         if (current->nsproxy->net_ns != &init_net)
1608                 return -EOPNOTSUPP;
1609
1610         /* On boot, we can set this without any fancy locking. */
1611         if (!nf_conntrack_htable_size)
1612                 return param_set_uint(val, kp);
1613
1614         rc = kstrtouint(val, 0, &hashsize);
1615         if (rc)
1616                 return rc;
1617         if (!hashsize)
1618                 return -EINVAL;
1619
1620         hash = nf_ct_alloc_hashtable(&hashsize, 1);
1621         if (!hash)
1622                 return -ENOMEM;
1623
1624         local_bh_disable();
1625         nf_conntrack_all_lock();
1626         write_seqcount_begin(&init_net.ct.generation);
1627
1628         /* Lookups in the old hash might happen in parallel, which means we
1629          * might get false negatives during connection lookup. New connections
1630          * created because of a false negative won't make it into the hash
1631          * though since that required taking the locks.
1632          */
1633
1634         for (i = 0; i < init_net.ct.htable_size; i++) {
1635                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1636                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1637                                         struct nf_conntrack_tuple_hash, hnnode);
1638                         ct = nf_ct_tuplehash_to_ctrack(h);
1639                         hlist_nulls_del_rcu(&h->hnnode);
1640                         bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1641                                                   hashsize);
1642                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1643                 }
1644         }
1645         old_size = init_net.ct.htable_size;
1646         old_hash = init_net.ct.hash;
1647
1648         init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1649         init_net.ct.hash = hash;
1650
1651         write_seqcount_end(&init_net.ct.generation);
1652         nf_conntrack_all_unlock();
1653         local_bh_enable();
1654
1655         nf_ct_free_hashtable(old_hash, old_size);
1656         return 0;
1657 }
1658 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1659
1660 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1661                   &nf_conntrack_htable_size, 0600);
1662
1663 void nf_ct_untracked_status_or(unsigned long bits)
1664 {
1665         int cpu;
1666
1667         for_each_possible_cpu(cpu)
1668                 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1669 }
1670 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1671
1672 int nf_conntrack_init_start(void)
1673 {
1674         int max_factor = 8;
1675         int i, ret, cpu;
1676
1677         for (i = 0; i < CONNTRACK_LOCKS; i++)
1678                 spin_lock_init(&nf_conntrack_locks[i]);
1679
1680         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1681          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1682         if (!nf_conntrack_htable_size) {
1683                 nf_conntrack_htable_size
1684                         = (((totalram_pages << PAGE_SHIFT) / 16384)
1685                            / sizeof(struct hlist_head));
1686                 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1687                         nf_conntrack_htable_size = 16384;
1688                 if (nf_conntrack_htable_size < 32)
1689                         nf_conntrack_htable_size = 32;
1690
1691                 /* Use a max. factor of four by default to get the same max as
1692                  * with the old struct list_heads. When a table size is given
1693                  * we use the old value of 8 to avoid reducing the max.
1694                  * entries. */
1695                 max_factor = 4;
1696         }
1697         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1698
1699         printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1700                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1701                nf_conntrack_max);
1702
1703         ret = nf_conntrack_expect_init();
1704         if (ret < 0)
1705                 goto err_expect;
1706
1707         ret = nf_conntrack_acct_init();
1708         if (ret < 0)
1709                 goto err_acct;
1710
1711         ret = nf_conntrack_tstamp_init();
1712         if (ret < 0)
1713                 goto err_tstamp;
1714
1715         ret = nf_conntrack_ecache_init();
1716         if (ret < 0)
1717                 goto err_ecache;
1718
1719         ret = nf_conntrack_timeout_init();
1720         if (ret < 0)
1721                 goto err_timeout;
1722
1723         ret = nf_conntrack_helper_init();
1724         if (ret < 0)
1725                 goto err_helper;
1726
1727         ret = nf_conntrack_labels_init();
1728         if (ret < 0)
1729                 goto err_labels;
1730
1731         ret = nf_conntrack_seqadj_init();
1732         if (ret < 0)
1733                 goto err_seqadj;
1734
1735 #ifdef CONFIG_NF_CONNTRACK_ZONES
1736         ret = nf_ct_extend_register(&nf_ct_zone_extend);
1737         if (ret < 0)
1738                 goto err_extend;
1739 #endif
1740         ret = nf_conntrack_proto_init();
1741         if (ret < 0)
1742                 goto err_proto;
1743
1744         /* Set up fake conntrack: to never be deleted, not in any hashes */
1745         for_each_possible_cpu(cpu) {
1746                 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1747                 write_pnet(&ct->ct_net, &init_net);
1748                 atomic_set(&ct->ct_general.use, 1);
1749         }
1750         /*  - and look it like as a confirmed connection */
1751         nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1752         return 0;
1753
1754 err_proto:
1755 #ifdef CONFIG_NF_CONNTRACK_ZONES
1756         nf_ct_extend_unregister(&nf_ct_zone_extend);
1757 err_extend:
1758 #endif
1759         nf_conntrack_seqadj_fini();
1760 err_seqadj:
1761         nf_conntrack_labels_fini();
1762 err_labels:
1763         nf_conntrack_helper_fini();
1764 err_helper:
1765         nf_conntrack_timeout_fini();
1766 err_timeout:
1767         nf_conntrack_ecache_fini();
1768 err_ecache:
1769         nf_conntrack_tstamp_fini();
1770 err_tstamp:
1771         nf_conntrack_acct_fini();
1772 err_acct:
1773         nf_conntrack_expect_fini();
1774 err_expect:
1775         return ret;
1776 }
1777
1778 void nf_conntrack_init_end(void)
1779 {
1780         /* For use by REJECT target */
1781         RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1782         RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1783 }
1784
1785 /*
1786  * We need to use special "null" values, not used in hash table
1787  */
1788 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
1789 #define DYING_NULLS_VAL         ((1<<30)+1)
1790 #define TEMPLATE_NULLS_VAL      ((1<<30)+2)
1791
1792 int nf_conntrack_init_net(struct net *net)
1793 {
1794         int ret = -ENOMEM;
1795         int cpu;
1796
1797         atomic_set(&net->ct.count, 0);
1798
1799         net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1800         if (!net->ct.pcpu_lists)
1801                 goto err_stat;
1802
1803         for_each_possible_cpu(cpu) {
1804                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1805
1806                 spin_lock_init(&pcpu->lock);
1807                 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1808                 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1809                 INIT_HLIST_NULLS_HEAD(&pcpu->tmpl, TEMPLATE_NULLS_VAL);
1810         }
1811
1812         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1813         if (!net->ct.stat)
1814                 goto err_pcpu_lists;
1815
1816         net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1817         if (!net->ct.slabname)
1818                 goto err_slabname;
1819
1820         net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1821                                                         sizeof(struct nf_conn), 0,
1822                                                         SLAB_DESTROY_BY_RCU, NULL);
1823         if (!net->ct.nf_conntrack_cachep) {
1824                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1825                 goto err_cache;
1826         }
1827
1828         net->ct.htable_size = nf_conntrack_htable_size;
1829         net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1830         if (!net->ct.hash) {
1831                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1832                 goto err_hash;
1833         }
1834         ret = nf_conntrack_expect_pernet_init(net);
1835         if (ret < 0)
1836                 goto err_expect;
1837         ret = nf_conntrack_acct_pernet_init(net);
1838         if (ret < 0)
1839                 goto err_acct;
1840         ret = nf_conntrack_tstamp_pernet_init(net);
1841         if (ret < 0)
1842                 goto err_tstamp;
1843         ret = nf_conntrack_ecache_pernet_init(net);
1844         if (ret < 0)
1845                 goto err_ecache;
1846         ret = nf_conntrack_helper_pernet_init(net);
1847         if (ret < 0)
1848                 goto err_helper;
1849         ret = nf_conntrack_proto_pernet_init(net);
1850         if (ret < 0)
1851                 goto err_proto;
1852         return 0;
1853
1854 err_proto:
1855         nf_conntrack_helper_pernet_fini(net);
1856 err_helper:
1857         nf_conntrack_ecache_pernet_fini(net);
1858 err_ecache:
1859         nf_conntrack_tstamp_pernet_fini(net);
1860 err_tstamp:
1861         nf_conntrack_acct_pernet_fini(net);
1862 err_acct:
1863         nf_conntrack_expect_pernet_fini(net);
1864 err_expect:
1865         nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1866 err_hash:
1867         kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1868 err_cache:
1869         kfree(net->ct.slabname);
1870 err_slabname:
1871         free_percpu(net->ct.stat);
1872 err_pcpu_lists:
1873         free_percpu(net->ct.pcpu_lists);
1874 err_stat:
1875         return ret;
1876 }