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   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  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
  14  *      - new API and handling of conntrack/nat helpers
  15  *      - now capable of multiple expectations for one master
  16  * 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
  17  *      - add usage/reference counts to ip_conntrack_expect
  18  *      - export ip_conntrack[_expect]_{find_get,put} functions
  19  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
  20  *      - generalize L3 protocol denendent part.
  21  * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
  22  *      - add support various size of conntrack structures.
  23  * 26 Jan 2006: Harald Welte <laforge@netfilter.org>
  24  *      - restructure nf_conn (introduce nf_conn_help)
  25  *      - redesign 'features' how they were originally intended
  26  * 26 Feb 2006: Pablo Neira Ayuso <pablo@eurodev.net>
  27  *      - add support for L3 protocol module load on demand.
  28  *
  29  * Derived from net/ipv4/netfilter/ip_conntrack_core.c
  30  */
  31
  32 #include <linux/types.h>
  33 #include <linux/netfilter.h>
  34 #include <linux/module.h>
  35 #include <linux/skbuff.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/vmalloc.h>
  38 #include <linux/stddef.h>
  39 #include <linux/slab.h>
  40 #include <linux/random.h>
  41 #include <linux/jhash.h>
  42 #include <linux/err.h>
  43 #include <linux/percpu.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/notifier.h>
  46 #include <linux/kernel.h>
  47 #include <linux/netdevice.h>
  48 #include <linux/socket.h>
  49
  50 #include <net/netfilter/nf_conntrack.h>
  51 #include <net/netfilter/nf_conntrack_l3proto.h>
  52 #include <net/netfilter/nf_conntrack_l4proto.h>
  53 #include <net/netfilter/nf_conntrack_expect.h>
  54 #include <net/netfilter/nf_conntrack_helper.h>
  55 #include <net/netfilter/nf_conntrack_core.h>
  56
  57 #define NF_CONNTRACK_VERSION    "0.5.0"
  58
  59 #if 0
  60 #define DEBUGP printk
  61 #else
  62 #define DEBUGP(format, args...)
  63 #endif
  64
  65 DEFINE_RWLOCK(nf_conntrack_lock);
  66
  67 /* nf_conntrack_standalone needs this */
  68 atomic_t nf_conntrack_count = ATOMIC_INIT(0);
  69
  70 void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL;
  71 unsigned int nf_conntrack_htable_size __read_mostly;
  72 int nf_conntrack_max __read_mostly;
  73 struct list_head *nf_conntrack_hash __read_mostly;
  74 struct nf_conn nf_conntrack_untracked __read_mostly;
  75 unsigned int nf_ct_log_invalid __read_mostly;
  76 LIST_HEAD(unconfirmed);
  77 static int nf_conntrack_vmalloc __read_mostly;
  78
  79 static unsigned int nf_conntrack_next_id;
  80
  81 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
  82 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
  83
  84 /*
  85  * This scheme offers various size of "struct nf_conn" dependent on
  86  * features(helper, nat, ...)
  87  */
  88
  89 #define NF_CT_FEATURES_NAMELEN  256
  90 static struct {
  91         /* name of slab cache. printed in /proc/slabinfo */
  92         char *name;
  93
  94         /* size of slab cache */
  95         size_t size;
  96
  97         /* slab cache pointer */
  98         kmem_cache_t *cachep;
  99
 100         /* allocated slab cache + modules which uses this slab cache */
 101         int use;
 102
 103 } nf_ct_cache[NF_CT_F_NUM];
 104
 105 /* protect members of nf_ct_cache except of "use" */
 106 DEFINE_RWLOCK(nf_ct_cache_lock);
 107
 108 /* This avoids calling kmem_cache_create() with same name simultaneously */
 109 static DEFINE_MUTEX(nf_ct_cache_mutex);
 110
 111 static int nf_conntrack_hash_rnd_initted;
 112 static unsigned int nf_conntrack_hash_rnd;
 113
 114 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
 115                                   unsigned int size, unsigned int rnd)
 116 {
 117         unsigned int a, b;
 118         a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all),
 119                   ((tuple->src.l3num) << 16) | tuple->dst.protonum);
 120         b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all),
 121                         (tuple->src.u.all << 16) | tuple->dst.u.all);
 122
 123         return jhash_2words(a, b, rnd) % size;
 124 }
 125
 126 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
 127 {
 128         return __hash_conntrack(tuple, nf_conntrack_htable_size,
 129                                 nf_conntrack_hash_rnd);
 130 }
 131
 132 int nf_conntrack_register_cache(u_int32_t features, const char *name,
 133                                 size_t size)
 134 {
 135         int ret = 0;
 136         char *cache_name;
 137         kmem_cache_t *cachep;
 138
 139         DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n",
 140                features, name, size);
 141
 142         if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) {
 143                 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n",
 144                         features);
 145                 return -EINVAL;
 146         }
 147
 148         mutex_lock(&nf_ct_cache_mutex);
 149
 150         write_lock_bh(&nf_ct_cache_lock);
 151         /* e.g: multiple helpers are loaded */
 152         if (nf_ct_cache[features].use > 0) {
 153                 DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
 154                 if ((!strncmp(nf_ct_cache[features].name, name,
 155                               NF_CT_FEATURES_NAMELEN))
 156                     && nf_ct_cache[features].size == size) {
 157                         DEBUGP("nf_conntrack_register_cache: reusing.\n");
 158                         nf_ct_cache[features].use++;
 159                         ret = 0;
 160                 } else
 161                         ret = -EBUSY;
 162
 163                 write_unlock_bh(&nf_ct_cache_lock);
 164                 mutex_unlock(&nf_ct_cache_mutex);
 165                 return ret;
 166         }
 167         write_unlock_bh(&nf_ct_cache_lock);
 168
 169         /*
 170          * The memory space for name of slab cache must be alive until
 171          * cache is destroyed.
 172          */
 173         cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC);
 174         if (cache_name == NULL) {
 175                 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n");
 176                 ret = -ENOMEM;
 177                 goto out_up_mutex;
 178         }
 179
 180         if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN)
 181                                                 >= NF_CT_FEATURES_NAMELEN) {
 182                 printk("nf_conntrack_register_cache: name too long\n");
 183                 ret = -EINVAL;
 184                 goto out_free_name;
 185         }
 186
 187         cachep = kmem_cache_create(cache_name, size, 0, 0,
 188                                    NULL, NULL);
 189         if (!cachep) {
 190                 printk("nf_conntrack_register_cache: Can't create slab cache "
 191                        "for the features = 0x%x\n", features);
 192                 ret = -ENOMEM;
 193                 goto out_free_name;
 194         }
 195
 196         write_lock_bh(&nf_ct_cache_lock);
 197         nf_ct_cache[features].use = 1;
 198         nf_ct_cache[features].size = size;
 199         nf_ct_cache[features].cachep = cachep;
 200         nf_ct_cache[features].name = cache_name;
 201         write_unlock_bh(&nf_ct_cache_lock);
 202
 203         goto out_up_mutex;
 204
 205 out_free_name:
 206         kfree(cache_name);
 207 out_up_mutex:
 208         mutex_unlock(&nf_ct_cache_mutex);
 209         return ret;
 210 }
 211
 212 /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */
 213 void nf_conntrack_unregister_cache(u_int32_t features)
 214 {
 215         kmem_cache_t *cachep;
 216         char *name;
 217
 218         /*
 219          * This assures that kmem_cache_create() isn't called before destroying
 220          * slab cache.
 221          */
 222         DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features);
 223         mutex_lock(&nf_ct_cache_mutex);
 224
 225         write_lock_bh(&nf_ct_cache_lock);
 226         if (--nf_ct_cache[features].use > 0) {
 227                 write_unlock_bh(&nf_ct_cache_lock);
 228                 mutex_unlock(&nf_ct_cache_mutex);
 229                 return;
 230         }
 231         cachep = nf_ct_cache[features].cachep;
 232         name = nf_ct_cache[features].name;
 233         nf_ct_cache[features].cachep = NULL;
 234         nf_ct_cache[features].name = NULL;
 235         nf_ct_cache[features].size = 0;
 236         write_unlock_bh(&nf_ct_cache_lock);
 237
 238         synchronize_net();
 239
 240         kmem_cache_destroy(cachep);
 241         kfree(name);
 242
 243         mutex_unlock(&nf_ct_cache_mutex);
 244 }
 245
 246 int
 247 nf_ct_get_tuple(const struct sk_buff *skb,
 248                 unsigned int nhoff,
 249                 unsigned int dataoff,
 250                 u_int16_t l3num,
 251                 u_int8_t protonum,
 252                 struct nf_conntrack_tuple *tuple,
 253                 const struct nf_conntrack_l3proto *l3proto,
 254                 const struct nf_conntrack_l4proto *l4proto)
 255 {
 256         NF_CT_TUPLE_U_BLANK(tuple);
 257
 258         tuple->src.l3num = l3num;
 259         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
 260                 return 0;
 261
 262         tuple->dst.protonum = protonum;
 263         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 264
 265         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
 266 }
 267
 268 int
 269 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 270                    const struct nf_conntrack_tuple *orig,
 271                    const struct nf_conntrack_l3proto *l3proto,
 272                    const struct nf_conntrack_l4proto *l4proto)
 273 {
 274         NF_CT_TUPLE_U_BLANK(inverse);
 275
 276         inverse->src.l3num = orig->src.l3num;
 277         if (l3proto->invert_tuple(inverse, orig) == 0)
 278                 return 0;
 279
 280         inverse->dst.dir = !orig->dst.dir;
 281
 282         inverse->dst.protonum = orig->dst.protonum;
 283         return l4proto->invert_tuple(inverse, orig);
 284 }
 285
 286 static void
 287 clean_from_lists(struct nf_conn *ct)
 288 {
 289         DEBUGP("clean_from_lists(%p)\n", ct);
 290         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
 291         list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list);
 292
 293         /* Destroy all pending expectations */
 294         nf_ct_remove_expectations(ct);
 295 }
 296
 297 static void
 298 destroy_conntrack(struct nf_conntrack *nfct)
 299 {
 300         struct nf_conn *ct = (struct nf_conn *)nfct;
 301         struct nf_conntrack_l3proto *l3proto;
 302         struct nf_conntrack_l4proto *l4proto;
 303
 304         DEBUGP("destroy_conntrack(%p)\n", ct);
 305         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
 306         NF_CT_ASSERT(!timer_pending(&ct->timeout));
 307
 308         nf_conntrack_event(IPCT_DESTROY, ct);
 309         set_bit(IPS_DYING_BIT, &ct->status);
 310
 311         /* To make sure we don't get any weird locking issues here:
 312          * destroy_conntrack() MUST NOT be called with a write lock
 313          * to nf_conntrack_lock!!! -HW */
 314         l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num);
 315         if (l3proto && l3proto->destroy)
 316                 l3proto->destroy(ct);
 317
 318         l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
 319         if (l4proto && l4proto->destroy)
 320                 l4proto->destroy(ct);
 321
 322         if (nf_conntrack_destroyed)
 323                 nf_conntrack_destroyed(ct);
 324
 325         write_lock_bh(&nf_conntrack_lock);
 326         /* Expectations will have been removed in clean_from_lists,
 327          * except TFTP can create an expectation on the first packet,
 328          * before connection is in the list, so we need to clean here,
 329          * too. */
 330         nf_ct_remove_expectations(ct);
 331
 332         /* We overload first tuple to link into unconfirmed list. */
 333         if (!nf_ct_is_confirmed(ct)) {
 334                 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
 335                 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
 336         }
 337
 338         NF_CT_STAT_INC(delete);
 339         write_unlock_bh(&nf_conntrack_lock);
 340
 341         if (ct->master)
 342                 nf_ct_put(ct->master);
 343
 344         DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
 345         nf_conntrack_free(ct);
 346 }
 347
 348 static void death_by_timeout(unsigned long ul_conntrack)
 349 {
 350         struct nf_conn *ct = (void *)ul_conntrack;
 351
 352         write_lock_bh(&nf_conntrack_lock);
 353         /* Inside lock so preempt is disabled on module removal path.
 354          * Otherwise we can get spurious warnings. */
 355         NF_CT_STAT_INC(delete_list);
 356         clean_from_lists(ct);
 357         write_unlock_bh(&nf_conntrack_lock);
 358         nf_ct_put(ct);
 359 }
 360
 361 struct nf_conntrack_tuple_hash *
 362 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
 363                     const struct nf_conn *ignored_conntrack)
 364 {
 365         struct nf_conntrack_tuple_hash *h;
 366         unsigned int hash = hash_conntrack(tuple);
 367
 368         list_for_each_entry(h, &nf_conntrack_hash[hash], list) {
 369                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
 370                     nf_ct_tuple_equal(tuple, &h->tuple)) {
 371                         NF_CT_STAT_INC(found);
 372                         return h;
 373                 }
 374                 NF_CT_STAT_INC(searched);
 375         }
 376
 377         return NULL;
 378 }
 379
 380 /* Find a connection corresponding to a tuple. */
 381 struct nf_conntrack_tuple_hash *
 382 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple,
 383                       const struct nf_conn *ignored_conntrack)
 384 {
 385         struct nf_conntrack_tuple_hash *h;
 386
 387         read_lock_bh(&nf_conntrack_lock);
 388         h = __nf_conntrack_find(tuple, ignored_conntrack);
 389         if (h)
 390                 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
 391         read_unlock_bh(&nf_conntrack_lock);
 392
 393         return h;
 394 }
 395
 396 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 397                                        unsigned int hash,
 398                                        unsigned int repl_hash)
 399 {
 400         ct->id = ++nf_conntrack_next_id;
 401         list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list,
 402                  &nf_conntrack_hash[hash]);
 403         list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list,
 404                  &nf_conntrack_hash[repl_hash]);
 405 }
 406
 407 void nf_conntrack_hash_insert(struct nf_conn *ct)
 408 {
 409         unsigned int hash, repl_hash;
 410
 411         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 412         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 413
 414         write_lock_bh(&nf_conntrack_lock);
 415         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 416         write_unlock_bh(&nf_conntrack_lock);
 417 }
 418
 419 /* Confirm a connection given skb; places it in hash table */
 420 int
 421 __nf_conntrack_confirm(struct sk_buff **pskb)
 422 {
 423         unsigned int hash, repl_hash;
 424         struct nf_conntrack_tuple_hash *h;
 425         struct nf_conn *ct;
 426         struct nf_conn_help *help;
 427         enum ip_conntrack_info ctinfo;
 428
 429         ct = nf_ct_get(*pskb, &ctinfo);
 430
 431         /* ipt_REJECT uses nf_conntrack_attach to attach related
 432            ICMP/TCP RST packets in other direction.  Actual packet
 433            which created connection will be IP_CT_NEW or for an
 434            expected connection, IP_CT_RELATED. */
 435         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 436                 return NF_ACCEPT;
 437
 438         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 439         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 440
 441         /* We're not in hash table, and we refuse to set up related
 442            connections for unconfirmed conns.  But packet copies and
 443            REJECT will give spurious warnings here. */
 444         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
 445
 446         /* No external references means noone else could have
 447            confirmed us. */
 448         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 449         DEBUGP("Confirming conntrack %p\n", ct);
 450
 451         write_lock_bh(&nf_conntrack_lock);
 452
 453         /* See if there's one in the list already, including reverse:
 454            NAT could have grabbed it without realizing, since we're
 455            not in the hash.  If there is, we lost race. */
 456         list_for_each_entry(h, &nf_conntrack_hash[hash], list)
 457                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 458                                       &h->tuple))
 459                         goto out;
 460         list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list)
 461                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 462                                       &h->tuple))
 463                         goto out;
 464
 465         /* Remove from unconfirmed list */
 466         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
 467
 468         __nf_conntrack_hash_insert(ct, hash, repl_hash);
 469         /* Timer relative to confirmation time, not original
 470            setting time, otherwise we'd get timer wrap in
 471            weird delay cases. */
 472         ct->timeout.expires += jiffies;
 473         add_timer(&ct->timeout);
 474         atomic_inc(&ct->ct_general.use);
 475         set_bit(IPS_CONFIRMED_BIT, &ct->status);
 476         NF_CT_STAT_INC(insert);
 477         write_unlock_bh(&nf_conntrack_lock);
 478         help = nfct_help(ct);
 479         if (help && help->helper)
 480                 nf_conntrack_event_cache(IPCT_HELPER, *pskb);
 481 #ifdef CONFIG_NF_NAT_NEEDED
 482         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
 483             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
 484                 nf_conntrack_event_cache(IPCT_NATINFO, *pskb);
 485 #endif
 486         nf_conntrack_event_cache(master_ct(ct) ?
 487                                  IPCT_RELATED : IPCT_NEW, *pskb);
 488         return NF_ACCEPT;
 489
 490 out:
 491         NF_CT_STAT_INC(insert_failed);
 492         write_unlock_bh(&nf_conntrack_lock);
 493         return NF_DROP;
 494 }
 495
 496 /* Returns true if a connection correspondings to the tuple (required
 497    for NAT). */
 498 int
 499 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 500                          const struct nf_conn *ignored_conntrack)
 501 {
 502         struct nf_conntrack_tuple_hash *h;
 503
 504         read_lock_bh(&nf_conntrack_lock);
 505         h = __nf_conntrack_find(tuple, ignored_conntrack);
 506         read_unlock_bh(&nf_conntrack_lock);
 507
 508         return h != NULL;
 509 }
 510
 511 /* There's a small race here where we may free a just-assured
 512    connection.  Too bad: we're in trouble anyway. */
 513 static int early_drop(struct list_head *chain)
 514 {
 515         /* Traverse backwards: gives us oldest, which is roughly LRU */
 516         struct nf_conntrack_tuple_hash *h;
 517         struct nf_conn *ct = NULL, *tmp;
 518         int dropped = 0;
 519
 520         read_lock_bh(&nf_conntrack_lock);
 521         list_for_each_entry_reverse(h, chain, list) {
 522                 tmp = nf_ct_tuplehash_to_ctrack(h);
 523                 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) {
 524                         ct = tmp;
 525                         atomic_inc(&ct->ct_general.use);
 526                         break;
 527                 }
 528         }
 529         read_unlock_bh(&nf_conntrack_lock);
 530
 531         if (!ct)
 532                 return dropped;
 533
 534         if (del_timer(&ct->timeout)) {
 535                 death_by_timeout((unsigned long)ct);
 536                 dropped = 1;
 537                 NF_CT_STAT_INC(early_drop);
 538         }
 539         nf_ct_put(ct);
 540         return dropped;
 541 }
 542
 543 static struct nf_conn *
 544 __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 545                      const struct nf_conntrack_tuple *repl,
 546                      const struct nf_conntrack_l3proto *l3proto)
 547 {
 548         struct nf_conn *conntrack = NULL;
 549         u_int32_t features = 0;
 550         struct nf_conntrack_helper *helper;
 551
 552         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
 553                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
 554                 nf_conntrack_hash_rnd_initted = 1;
 555         }
 556
 557         /* We don't want any race condition at early drop stage */
 558         atomic_inc(&nf_conntrack_count);
 559
 560         if (nf_conntrack_max
 561             && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
 562                 unsigned int hash = hash_conntrack(orig);
 563                 /* Try dropping from this hash chain. */
 564                 if (!early_drop(&nf_conntrack_hash[hash])) {
 565                         atomic_dec(&nf_conntrack_count);
 566                         if (net_ratelimit())
 567                                 printk(KERN_WARNING
 568                                        "nf_conntrack: table full, dropping"
 569                                        " packet.\n");
 570                         return ERR_PTR(-ENOMEM);
 571                 }
 572         }
 573
 574         /*  find features needed by this conntrack. */
 575         features = l3proto->get_features(orig);
 576
 577         /* FIXME: protect helper list per RCU */
 578         read_lock_bh(&nf_conntrack_lock);
 579         helper = __nf_ct_helper_find(repl);
 580         if (helper)
 581                 features |= NF_CT_F_HELP;
 582         read_unlock_bh(&nf_conntrack_lock);
 583
 584         DEBUGP("nf_conntrack_alloc: features=0x%x\n", features);
 585
 586         read_lock_bh(&nf_ct_cache_lock);
 587
 588         if (unlikely(!nf_ct_cache[features].use)) {
 589                 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
 590                         features);
 591                 goto out;
 592         }
 593
 594         conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC);
 595         if (conntrack == NULL) {
 596                 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n");
 597                 goto out;
 598         }
 599
 600         memset(conntrack, 0, nf_ct_cache[features].size);
 601         conntrack->features = features;
 602         atomic_set(&conntrack->ct_general.use, 1);
 603         conntrack->ct_general.destroy = destroy_conntrack;
 604         conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 605         conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
 606         /* Don't set timer yet: wait for confirmation */
 607         init_timer(&conntrack->timeout);
 608         conntrack->timeout.data = (unsigned long)conntrack;
 609         conntrack->timeout.function = death_by_timeout;
 610         read_unlock_bh(&nf_ct_cache_lock);
 611
 612         return conntrack;
 613 out:
 614         read_unlock_bh(&nf_ct_cache_lock);
 615         atomic_dec(&nf_conntrack_count);
 616         return conntrack;
 617 }
 618
 619 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 620                                    const struct nf_conntrack_tuple *repl)
 621 {
 622         struct nf_conntrack_l3proto *l3proto;
 623
 624         l3proto = __nf_ct_l3proto_find(orig->src.l3num);
 625         return __nf_conntrack_alloc(orig, repl, l3proto);
 626 }
 627
 628 void nf_conntrack_free(struct nf_conn *conntrack)
 629 {
 630         u_int32_t features = conntrack->features;
 631         NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM);
 632         DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features,
 633                conntrack);
 634         kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
 635         atomic_dec(&nf_conntrack_count);
 636 }
 637
 638 /* Allocate a new conntrack: we return -ENOMEM if classification
 639    failed due to stress.  Otherwise it really is unclassifiable. */
 640 static struct nf_conntrack_tuple_hash *
 641 init_conntrack(const struct nf_conntrack_tuple *tuple,
 642                struct nf_conntrack_l3proto *l3proto,
 643                struct nf_conntrack_l4proto *l4proto,
 644                struct sk_buff *skb,
 645                unsigned int dataoff)
 646 {
 647         struct nf_conn *conntrack;
 648         struct nf_conntrack_tuple repl_tuple;
 649         struct nf_conntrack_expect *exp;
 650
 651         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
 652                 DEBUGP("Can't invert tuple.\n");
 653                 return NULL;
 654         }
 655
 656         conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto);
 657         if (conntrack == NULL || IS_ERR(conntrack)) {
 658                 DEBUGP("Can't allocate conntrack.\n");
 659                 return (struct nf_conntrack_tuple_hash *)conntrack;
 660         }
 661
 662         if (!l4proto->new(conntrack, skb, dataoff)) {
 663                 nf_conntrack_free(conntrack);
 664                 DEBUGP("init conntrack: can't track with proto module\n");
 665                 return NULL;
 666         }
 667
 668         write_lock_bh(&nf_conntrack_lock);
 669         exp = find_expectation(tuple);
 670
 671         if (exp) {
 672                 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
 673                         conntrack, exp);
 674                 /* Welcome, Mr. Bond.  We've been expecting you... */
 675                 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
 676                 conntrack->master = exp->master;
 677 #ifdef CONFIG_NF_CONNTRACK_MARK
 678                 conntrack->mark = exp->master->mark;
 679 #endif
 680 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 681                 conntrack->secmark = exp->master->secmark;
 682 #endif
 683                 nf_conntrack_get(&conntrack->master->ct_general);
 684                 NF_CT_STAT_INC(expect_new);
 685         } else {
 686                 struct nf_conn_help *help = nfct_help(conntrack);
 687
 688                 if (help)
 689                         help->helper = __nf_ct_helper_find(&repl_tuple);
 690                 NF_CT_STAT_INC(new);
 691         }
 692
 693         /* Overload tuple linked list to put us in unconfirmed list. */
 694         list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
 695
 696         write_unlock_bh(&nf_conntrack_lock);
 697
 698         if (exp) {
 699                 if (exp->expectfn)
 700                         exp->expectfn(conntrack, exp);
 701                 nf_conntrack_expect_put(exp);
 702         }
 703
 704         return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
 705 }
 706
 707 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
 708 static inline struct nf_conn *
 709 resolve_normal_ct(struct sk_buff *skb,
 710                   unsigned int dataoff,
 711                   u_int16_t l3num,
 712                   u_int8_t protonum,
 713                   struct nf_conntrack_l3proto *l3proto,
 714                   struct nf_conntrack_l4proto *l4proto,
 715                   int *set_reply,
 716                   enum ip_conntrack_info *ctinfo)
 717 {
 718         struct nf_conntrack_tuple tuple;
 719         struct nf_conntrack_tuple_hash *h;
 720         struct nf_conn *ct;
 721
 722         if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data),
 723                              dataoff, l3num, protonum, &tuple, l3proto,
 724                              l4proto)) {
 725                 DEBUGP("resolve_normal_ct: Can't get tuple\n");
 726                 return NULL;
 727         }
 728
 729         /* look for tuple match */
 730         h = nf_conntrack_find_get(&tuple, NULL);
 731         if (!h) {
 732                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
 733                 if (!h)
 734                         return NULL;
 735                 if (IS_ERR(h))
 736                         return (void *)h;
 737         }
 738         ct = nf_ct_tuplehash_to_ctrack(h);
 739
 740         /* It exists; we have (non-exclusive) reference. */
 741         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
 742                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
 743                 /* Please set reply bit if this packet OK */
 744                 *set_reply = 1;
 745         } else {
 746                 /* Once we've had two way comms, always ESTABLISHED. */
 747                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 748                         DEBUGP("nf_conntrack_in: normal packet for %p\n", ct);
 749                         *ctinfo = IP_CT_ESTABLISHED;
 750                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
 751                         DEBUGP("nf_conntrack_in: related packet for %p\n", ct);
 752                         *ctinfo = IP_CT_RELATED;
 753                 } else {
 754                         DEBUGP("nf_conntrack_in: new packet for %p\n", ct);
 755                         *ctinfo = IP_CT_NEW;
 756                 }
 757                 *set_reply = 0;
 758         }
 759         skb->nfct = &ct->ct_general;
 760         skb->nfctinfo = *ctinfo;
 761         return ct;
 762 }
 763
 764 unsigned int
 765 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
 766 {
 767         struct nf_conn *ct;
 768         enum ip_conntrack_info ctinfo;
 769         struct nf_conntrack_l3proto *l3proto;
 770         struct nf_conntrack_l4proto *l4proto;
 771         unsigned int dataoff;
 772         u_int8_t protonum;
 773         int set_reply = 0;
 774         int ret;
 775
 776         /* Previously seen (loopback or untracked)?  Ignore. */
 777         if ((*pskb)->nfct) {
 778                 NF_CT_STAT_INC(ignore);
 779                 return NF_ACCEPT;
 780         }
 781
 782         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
 783         if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) {
 784                 DEBUGP("not prepared to track yet or error occured\n");
 785                 return -ret;
 786         }
 787
 788         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
 789
 790         /* It may be an special packet, error, unclean...
 791          * inverse of the return code tells to the netfilter
 792          * core what to do with the packet. */
 793         if (l4proto->error != NULL &&
 794             (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
 795                 NF_CT_STAT_INC(error);
 796                 NF_CT_STAT_INC(invalid);
 797                 return -ret;
 798         }
 799
 800         ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto,
 801                                &set_reply, &ctinfo);
 802         if (!ct) {
 803                 /* Not valid part of a connection */
 804                 NF_CT_STAT_INC(invalid);
 805                 return NF_ACCEPT;
 806         }
 807
 808         if (IS_ERR(ct)) {
 809                 /* Too stressed to deal. */
 810                 NF_CT_STAT_INC(drop);
 811                 return NF_DROP;
 812         }
 813
 814         NF_CT_ASSERT((*pskb)->nfct);
 815
 816         ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum);
 817         if (ret < 0) {
 818                 /* Invalid: inverse of the return code tells
 819                  * the netfilter core what to do */
 820                 DEBUGP("nf_conntrack_in: Can't track with proto module\n");
 821                 nf_conntrack_put((*pskb)->nfct);
 822                 (*pskb)->nfct = NULL;
 823                 NF_CT_STAT_INC(invalid);
 824                 return -ret;
 825         }
 826
 827         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 828                 nf_conntrack_event_cache(IPCT_STATUS, *pskb);
 829
 830         return ret;
 831 }
 832
 833 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 834                          const struct nf_conntrack_tuple *orig)
 835 {
 836         return nf_ct_invert_tuple(inverse, orig,
 837                                   __nf_ct_l3proto_find(orig->src.l3num),
 838                                   __nf_ct_l4proto_find(orig->src.l3num,
 839                                                      orig->dst.protonum));
 840 }
 841
 842 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
 843 void __nf_ct_refresh_acct(struct nf_conn *ct,
 844                           enum ip_conntrack_info ctinfo,
 845                           const struct sk_buff *skb,
 846                           unsigned long extra_jiffies,
 847                           int do_acct)
 848 {
 849         int event = 0;
 850
 851         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
 852         NF_CT_ASSERT(skb);
 853
 854         write_lock_bh(&nf_conntrack_lock);
 855
 856         /* Only update if this is not a fixed timeout */
 857         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
 858                 write_unlock_bh(&nf_conntrack_lock);
 859                 return;
 860         }
 861
 862         /* If not in hash table, timer will not be active yet */
 863         if (!nf_ct_is_confirmed(ct)) {
 864                 ct->timeout.expires = extra_jiffies;
 865                 event = IPCT_REFRESH;
 866         } else {
 867                 unsigned long newtime = jiffies + extra_jiffies;
 868
 869                 /* Only update the timeout if the new timeout is at least
 870                    HZ jiffies from the old timeout. Need del_timer for race
 871                    avoidance (may already be dying). */
 872                 if (newtime - ct->timeout.expires >= HZ
 873                     && del_timer(&ct->timeout)) {
 874                         ct->timeout.expires = newtime;
 875                         add_timer(&ct->timeout);
 876                         event = IPCT_REFRESH;
 877                 }
 878         }
 879
 880 #ifdef CONFIG_NF_CT_ACCT
 881         if (do_acct) {
 882                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
 883                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
 884                         skb->len - (unsigned int)(skb->nh.raw - skb->data);
 885
 886                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
 887                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
 888                         event |= IPCT_COUNTER_FILLING;
 889         }
 890 #endif
 891
 892         write_unlock_bh(&nf_conntrack_lock);
 893
 894         /* must be unlocked when calling event cache */
 895         if (event)
 896                 nf_conntrack_event_cache(event, skb);
 897 }
 898
 899 #if defined(CONFIG_NF_CT_NETLINK) || \
 900     defined(CONFIG_NF_CT_NETLINK_MODULE)
 901
 902 #include <linux/netfilter/nfnetlink.h>
 903 #include <linux/netfilter/nfnetlink_conntrack.h>
 904 #include <linux/mutex.h>
 905
 906
 907 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
 908  * in ip_conntrack_core, since we don't want the protocols to autoload
 909  * or depend on ctnetlink */
 910 int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
 911                                const struct nf_conntrack_tuple *tuple)
 912 {
 913         NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
 914                 &tuple->src.u.tcp.port);
 915         NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
 916                 &tuple->dst.u.tcp.port);
 917         return 0;
 918
 919 nfattr_failure:
 920         return -1;
 921 }
 922
 923 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
 924         [CTA_PROTO_SRC_PORT-1]  = sizeof(u_int16_t),
 925         [CTA_PROTO_DST_PORT-1]  = sizeof(u_int16_t)
 926 };
 927
 928 int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
 929                                struct nf_conntrack_tuple *t)
 930 {
 931         if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
 932                 return -EINVAL;
 933
 934         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
 935                 return -EINVAL;
 936
 937         t->src.u.tcp.port =
 938                 *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
 939         t->dst.u.tcp.port =
 940                 *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
 941
 942         return 0;
 943 }
 944 #endif
 945
 946 /* Used by ipt_REJECT and ip6t_REJECT. */
 947 void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
 948 {
 949         struct nf_conn *ct;
 950         enum ip_conntrack_info ctinfo;
 951
 952         /* This ICMP is in reverse direction to the packet which caused it */
 953         ct = nf_ct_get(skb, &ctinfo);
 954         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
 955                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
 956         else
 957                 ctinfo = IP_CT_RELATED;
 958
 959         /* Attach to new skbuff, and increment count */
 960         nskb->nfct = &ct->ct_general;
 961         nskb->nfctinfo = ctinfo;
 962         nf_conntrack_get(nskb->nfct);
 963 }
 964
 965 static inline int
 966 do_iter(const struct nf_conntrack_tuple_hash *i,
 967         int (*iter)(struct nf_conn *i, void *data),
 968         void *data)
 969 {
 970         return iter(nf_ct_tuplehash_to_ctrack(i), data);
 971 }
 972
 973 /* Bring out ya dead! */
 974 static struct nf_conn *
 975 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
 976                 void *data, unsigned int *bucket)
 977 {
 978         struct nf_conntrack_tuple_hash *h;
 979         struct nf_conn *ct;
 980
 981         write_lock_bh(&nf_conntrack_lock);
 982         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
 983                 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) {
 984                         ct = nf_ct_tuplehash_to_ctrack(h);
 985                         if (iter(ct, data))
 986                                 goto found;
 987                 }
 988         }
 989         list_for_each_entry(h, &unconfirmed, list) {
 990                 ct = nf_ct_tuplehash_to_ctrack(h);
 991                 if (iter(ct, data))
 992                         goto found;
 993         }
 994         write_unlock_bh(&nf_conntrack_lock);
 995         return NULL;
 996 found:
 997         atomic_inc(&ct->ct_general.use);
 998         write_unlock_bh(&nf_conntrack_lock);
 999         return ct;
1000 }
1001
1002 void
1003 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
1004 {
1005         struct nf_conn *ct;
1006         unsigned int bucket = 0;
1007
1008         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
1009                 /* Time to push up daises... */
1010                 if (del_timer(&ct->timeout))
1011                         death_by_timeout((unsigned long)ct);
1012                 /* ... else the timer will get him soon. */
1013
1014                 nf_ct_put(ct);
1015         }
1016 }
1017
1018 static int kill_all(struct nf_conn *i, void *data)
1019 {
1020         return 1;
1021 }
1022
1023 static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size)
1024 {
1025         if (vmalloced)
1026                 vfree(hash);
1027         else
1028                 free_pages((unsigned long)hash,
1029                            get_order(sizeof(struct list_head) * size));
1030 }
1031
1032 void nf_conntrack_flush()
1033 {
1034         nf_ct_iterate_cleanup(kill_all, NULL);
1035 }
1036
1037 /* Mishearing the voices in his head, our hero wonders how he's
1038    supposed to kill the mall. */
1039 void nf_conntrack_cleanup(void)
1040 {
1041         int i;
1042
1043         ip_ct_attach = NULL;
1044
1045         /* This makes sure all current packets have passed through
1046            netfilter framework.  Roll on, two-stage module
1047            delete... */
1048         synchronize_net();
1049
1050         nf_ct_event_cache_flush();
1051  i_see_dead_people:
1052         nf_conntrack_flush();
1053         if (atomic_read(&nf_conntrack_count) != 0) {
1054                 schedule();
1055                 goto i_see_dead_people;
1056         }
1057         /* wait until all references to nf_conntrack_untracked are dropped */
1058         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1059                 schedule();
1060
1061         for (i = 0; i < NF_CT_F_NUM; i++) {
1062                 if (nf_ct_cache[i].use == 0)
1063                         continue;
1064
1065                 NF_CT_ASSERT(nf_ct_cache[i].use == 1);
1066                 nf_ct_cache[i].use = 1;
1067                 nf_conntrack_unregister_cache(i);
1068         }
1069         kmem_cache_destroy(nf_conntrack_expect_cachep);
1070         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1071                             nf_conntrack_htable_size);
1072
1073         /* free l3proto protocol tables */
1074         for (i = 0; i < PF_MAX; i++)
1075                 if (nf_ct_protos[i]) {
1076                         kfree(nf_ct_protos[i]);
1077                         nf_ct_protos[i] = NULL;
1078                 }
1079 }
1080
1081 static struct list_head *alloc_hashtable(int size, int *vmalloced)
1082 {
1083         struct list_head *hash;
1084         unsigned int i;
1085
1086         *vmalloced = 0;
1087         hash = (void*)__get_free_pages(GFP_KERNEL,
1088                                        get_order(sizeof(struct list_head)
1089                                                  * size));
1090         if (!hash) {
1091                 *vmalloced = 1;
1092                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1093                 hash = vmalloc(sizeof(struct list_head) * size);
1094         }
1095
1096         if (hash)
1097                 for (i = 0; i < size; i++)
1098                         INIT_LIST_HEAD(&hash[i]);
1099
1100         return hash;
1101 }
1102
1103 int set_hashsize(const char *val, struct kernel_param *kp)
1104 {
1105         int i, bucket, hashsize, vmalloced;
1106         int old_vmalloced, old_size;
1107         int rnd;
1108         struct list_head *hash, *old_hash;
1109         struct nf_conntrack_tuple_hash *h;
1110
1111         /* On boot, we can set this without any fancy locking. */
1112         if (!nf_conntrack_htable_size)
1113                 return param_set_uint(val, kp);
1114
1115         hashsize = simple_strtol(val, NULL, 0);
1116         if (!hashsize)
1117                 return -EINVAL;
1118
1119         hash = alloc_hashtable(hashsize, &vmalloced);
1120         if (!hash)
1121                 return -ENOMEM;
1122
1123         /* We have to rehahs for the new table anyway, so we also can
1124          * use a newrandom seed */
1125         get_random_bytes(&rnd, 4);
1126
1127         write_lock_bh(&nf_conntrack_lock);
1128         for (i = 0; i < nf_conntrack_htable_size; i++) {
1129                 while (!list_empty(&nf_conntrack_hash[i])) {
1130                         h = list_entry(nf_conntrack_hash[i].next,
1131                                        struct nf_conntrack_tuple_hash, list);
1132                         list_del(&h->list);
1133                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1134                         list_add_tail(&h->list, &hash[bucket]);
1135                 }
1136         }
1137         old_size = nf_conntrack_htable_size;
1138         old_vmalloced = nf_conntrack_vmalloc;
1139         old_hash = nf_conntrack_hash;
1140
1141         nf_conntrack_htable_size = hashsize;
1142         nf_conntrack_vmalloc = vmalloced;
1143         nf_conntrack_hash = hash;
1144         nf_conntrack_hash_rnd = rnd;
1145         write_unlock_bh(&nf_conntrack_lock);
1146
1147         free_conntrack_hash(old_hash, old_vmalloced, old_size);
1148         return 0;
1149 }
1150
1151 module_param_call(hashsize, set_hashsize, param_get_uint,
1152                   &nf_conntrack_htable_size, 0600);
1153
1154 int __init nf_conntrack_init(void)
1155 {
1156         unsigned int i;
1157         int ret;
1158
1159         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1160          * machine has 256 buckets.  >= 1GB machines have 8192 buckets. */
1161         if (!nf_conntrack_htable_size) {
1162                 nf_conntrack_htable_size
1163                         = (((num_physpages << PAGE_SHIFT) / 16384)
1164                            / sizeof(struct list_head));
1165                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1166                         nf_conntrack_htable_size = 8192;
1167                 if (nf_conntrack_htable_size < 16)
1168                         nf_conntrack_htable_size = 16;
1169         }
1170         nf_conntrack_max = 8 * nf_conntrack_htable_size;
1171
1172         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1173                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1174                nf_conntrack_max);
1175
1176         nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size,
1177                                             &nf_conntrack_vmalloc);
1178         if (!nf_conntrack_hash) {
1179                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1180                 goto err_out;
1181         }
1182
1183         ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic",
1184                                           sizeof(struct nf_conn));
1185         if (ret < 0) {
1186                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1187                 goto err_free_hash;
1188         }
1189
1190         nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect",
1191                                         sizeof(struct nf_conntrack_expect),
1192                                         0, 0, NULL, NULL);
1193         if (!nf_conntrack_expect_cachep) {
1194                 printk(KERN_ERR "Unable to create nf_expect slab cache\n");
1195                 goto err_free_conntrack_slab;
1196         }
1197
1198         /* Don't NEED lock here, but good form anyway. */
1199         write_lock_bh(&nf_conntrack_lock);
1200         for (i = 0; i < AF_MAX; i++)
1201                 nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic;
1202         write_unlock_bh(&nf_conntrack_lock);
1203
1204         /* For use by REJECT target */
1205         ip_ct_attach = __nf_conntrack_attach;
1206
1207         /* Set up fake conntrack:
1208             - to never be deleted, not in any hashes */
1209         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1210         /*  - and look it like as a confirmed connection */
1211         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1212
1213         return ret;
1214
1215 err_free_conntrack_slab:
1216         nf_conntrack_unregister_cache(NF_CT_F_BASIC);
1217 err_free_hash:
1218         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1219                             nf_conntrack_htable_size);
1220 err_out:
1221         return -ENOMEM;
1222 }