nf_conntrack_core.c revision 982d9a9ce389c396bc83ce29d799937f379ddcb7
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#include <linux/mm.h> 50 51#include <net/netfilter/nf_conntrack.h> 52#include <net/netfilter/nf_conntrack_l3proto.h> 53#include <net/netfilter/nf_conntrack_l4proto.h> 54#include <net/netfilter/nf_conntrack_expect.h> 55#include <net/netfilter/nf_conntrack_helper.h> 56#include <net/netfilter/nf_conntrack_core.h> 57 58#define NF_CONNTRACK_VERSION "0.5.0" 59 60#if 0 61#define DEBUGP printk 62#else 63#define DEBUGP(format, args...) 64#endif 65 66DEFINE_RWLOCK(nf_conntrack_lock); 67EXPORT_SYMBOL_GPL(nf_conntrack_lock); 68 69/* nf_conntrack_standalone needs this */ 70atomic_t nf_conntrack_count = ATOMIC_INIT(0); 71EXPORT_SYMBOL_GPL(nf_conntrack_count); 72 73void (*nf_conntrack_destroyed)(struct nf_conn *conntrack); 74EXPORT_SYMBOL_GPL(nf_conntrack_destroyed); 75 76unsigned int nf_conntrack_htable_size __read_mostly; 77EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); 78 79int nf_conntrack_max __read_mostly; 80EXPORT_SYMBOL_GPL(nf_conntrack_max); 81 82struct list_head *nf_conntrack_hash __read_mostly; 83EXPORT_SYMBOL_GPL(nf_conntrack_hash); 84 85struct nf_conn nf_conntrack_untracked __read_mostly; 86EXPORT_SYMBOL_GPL(nf_conntrack_untracked); 87 88unsigned int nf_ct_log_invalid __read_mostly; 89LIST_HEAD(unconfirmed); 90static int nf_conntrack_vmalloc __read_mostly; 91 92static unsigned int nf_conntrack_next_id; 93 94DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); 95EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); 96 97/* 98 * This scheme offers various size of "struct nf_conn" dependent on 99 * features(helper, nat, ...) 100 */ 101 102#define NF_CT_FEATURES_NAMELEN 256 103static struct { 104 /* name of slab cache. printed in /proc/slabinfo */ 105 char *name; 106 107 /* size of slab cache */ 108 size_t size; 109 110 /* slab cache pointer */ 111 struct kmem_cache *cachep; 112 113 /* allocated slab cache + modules which uses this slab cache */ 114 int use; 115 116} nf_ct_cache[NF_CT_F_NUM]; 117 118/* protect members of nf_ct_cache except of "use" */ 119DEFINE_RWLOCK(nf_ct_cache_lock); 120 121/* This avoids calling kmem_cache_create() with same name simultaneously */ 122static DEFINE_MUTEX(nf_ct_cache_mutex); 123 124static int nf_conntrack_hash_rnd_initted; 125static unsigned int nf_conntrack_hash_rnd; 126 127static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, 128 unsigned int size, unsigned int rnd) 129{ 130 unsigned int a, b; 131 a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), 132 ((tuple->src.l3num) << 16) | tuple->dst.protonum); 133 b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), 134 (tuple->src.u.all << 16) | tuple->dst.u.all); 135 136 return jhash_2words(a, b, rnd) % size; 137} 138 139static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) 140{ 141 return __hash_conntrack(tuple, nf_conntrack_htable_size, 142 nf_conntrack_hash_rnd); 143} 144 145int nf_conntrack_register_cache(u_int32_t features, const char *name, 146 size_t size) 147{ 148 int ret = 0; 149 char *cache_name; 150 struct kmem_cache *cachep; 151 152 DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", 153 features, name, size); 154 155 if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { 156 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", 157 features); 158 return -EINVAL; 159 } 160 161 mutex_lock(&nf_ct_cache_mutex); 162 163 write_lock_bh(&nf_ct_cache_lock); 164 /* e.g: multiple helpers are loaded */ 165 if (nf_ct_cache[features].use > 0) { 166 DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); 167 if ((!strncmp(nf_ct_cache[features].name, name, 168 NF_CT_FEATURES_NAMELEN)) 169 && nf_ct_cache[features].size == size) { 170 DEBUGP("nf_conntrack_register_cache: reusing.\n"); 171 nf_ct_cache[features].use++; 172 ret = 0; 173 } else 174 ret = -EBUSY; 175 176 write_unlock_bh(&nf_ct_cache_lock); 177 mutex_unlock(&nf_ct_cache_mutex); 178 return ret; 179 } 180 write_unlock_bh(&nf_ct_cache_lock); 181 182 /* 183 * The memory space for name of slab cache must be alive until 184 * cache is destroyed. 185 */ 186 cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); 187 if (cache_name == NULL) { 188 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); 189 ret = -ENOMEM; 190 goto out_up_mutex; 191 } 192 193 if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) 194 >= NF_CT_FEATURES_NAMELEN) { 195 printk("nf_conntrack_register_cache: name too long\n"); 196 ret = -EINVAL; 197 goto out_free_name; 198 } 199 200 cachep = kmem_cache_create(cache_name, size, 0, 0, 201 NULL, NULL); 202 if (!cachep) { 203 printk("nf_conntrack_register_cache: Can't create slab cache " 204 "for the features = 0x%x\n", features); 205 ret = -ENOMEM; 206 goto out_free_name; 207 } 208 209 write_lock_bh(&nf_ct_cache_lock); 210 nf_ct_cache[features].use = 1; 211 nf_ct_cache[features].size = size; 212 nf_ct_cache[features].cachep = cachep; 213 nf_ct_cache[features].name = cache_name; 214 write_unlock_bh(&nf_ct_cache_lock); 215 216 goto out_up_mutex; 217 218out_free_name: 219 kfree(cache_name); 220out_up_mutex: 221 mutex_unlock(&nf_ct_cache_mutex); 222 return ret; 223} 224EXPORT_SYMBOL_GPL(nf_conntrack_register_cache); 225 226/* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ 227void nf_conntrack_unregister_cache(u_int32_t features) 228{ 229 struct kmem_cache *cachep; 230 char *name; 231 232 /* 233 * This assures that kmem_cache_create() isn't called before destroying 234 * slab cache. 235 */ 236 DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); 237 mutex_lock(&nf_ct_cache_mutex); 238 239 write_lock_bh(&nf_ct_cache_lock); 240 if (--nf_ct_cache[features].use > 0) { 241 write_unlock_bh(&nf_ct_cache_lock); 242 mutex_unlock(&nf_ct_cache_mutex); 243 return; 244 } 245 cachep = nf_ct_cache[features].cachep; 246 name = nf_ct_cache[features].name; 247 nf_ct_cache[features].cachep = NULL; 248 nf_ct_cache[features].name = NULL; 249 nf_ct_cache[features].size = 0; 250 write_unlock_bh(&nf_ct_cache_lock); 251 252 synchronize_net(); 253 254 kmem_cache_destroy(cachep); 255 kfree(name); 256 257 mutex_unlock(&nf_ct_cache_mutex); 258} 259EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache); 260 261int 262nf_ct_get_tuple(const struct sk_buff *skb, 263 unsigned int nhoff, 264 unsigned int dataoff, 265 u_int16_t l3num, 266 u_int8_t protonum, 267 struct nf_conntrack_tuple *tuple, 268 const struct nf_conntrack_l3proto *l3proto, 269 const struct nf_conntrack_l4proto *l4proto) 270{ 271 NF_CT_TUPLE_U_BLANK(tuple); 272 273 tuple->src.l3num = l3num; 274 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) 275 return 0; 276 277 tuple->dst.protonum = protonum; 278 tuple->dst.dir = IP_CT_DIR_ORIGINAL; 279 280 return l4proto->pkt_to_tuple(skb, dataoff, tuple); 281} 282EXPORT_SYMBOL_GPL(nf_ct_get_tuple); 283 284int 285nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, 286 const struct nf_conntrack_tuple *orig, 287 const struct nf_conntrack_l3proto *l3proto, 288 const struct nf_conntrack_l4proto *l4proto) 289{ 290 NF_CT_TUPLE_U_BLANK(inverse); 291 292 inverse->src.l3num = orig->src.l3num; 293 if (l3proto->invert_tuple(inverse, orig) == 0) 294 return 0; 295 296 inverse->dst.dir = !orig->dst.dir; 297 298 inverse->dst.protonum = orig->dst.protonum; 299 return l4proto->invert_tuple(inverse, orig); 300} 301EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); 302 303static void 304clean_from_lists(struct nf_conn *ct) 305{ 306 DEBUGP("clean_from_lists(%p)\n", ct); 307 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 308 list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); 309 310 /* Destroy all pending expectations */ 311 nf_ct_remove_expectations(ct); 312} 313 314static void 315destroy_conntrack(struct nf_conntrack *nfct) 316{ 317 struct nf_conn *ct = (struct nf_conn *)nfct; 318 struct nf_conn_help *help = nfct_help(ct); 319 struct nf_conntrack_l3proto *l3proto; 320 struct nf_conntrack_l4proto *l4proto; 321 typeof(nf_conntrack_destroyed) destroyed; 322 323 DEBUGP("destroy_conntrack(%p)\n", ct); 324 NF_CT_ASSERT(atomic_read(&nfct->use) == 0); 325 NF_CT_ASSERT(!timer_pending(&ct->timeout)); 326 327 nf_conntrack_event(IPCT_DESTROY, ct); 328 set_bit(IPS_DYING_BIT, &ct->status); 329 330 if (help && help->helper && help->helper->destroy) 331 help->helper->destroy(ct); 332 333 /* To make sure we don't get any weird locking issues here: 334 * destroy_conntrack() MUST NOT be called with a write lock 335 * to nf_conntrack_lock!!! -HW */ 336 rcu_read_lock(); 337 l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); 338 if (l3proto && l3proto->destroy) 339 l3proto->destroy(ct); 340 341 l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, 342 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); 343 if (l4proto && l4proto->destroy) 344 l4proto->destroy(ct); 345 346 destroyed = rcu_dereference(nf_conntrack_destroyed); 347 if (destroyed) 348 destroyed(ct); 349 350 rcu_read_unlock(); 351 352 write_lock_bh(&nf_conntrack_lock); 353 /* Expectations will have been removed in clean_from_lists, 354 * except TFTP can create an expectation on the first packet, 355 * before connection is in the list, so we need to clean here, 356 * too. */ 357 nf_ct_remove_expectations(ct); 358 359 /* We overload first tuple to link into unconfirmed list. */ 360 if (!nf_ct_is_confirmed(ct)) { 361 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); 362 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 363 } 364 365 NF_CT_STAT_INC(delete); 366 write_unlock_bh(&nf_conntrack_lock); 367 368 if (ct->master) 369 nf_ct_put(ct->master); 370 371 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); 372 nf_conntrack_free(ct); 373} 374 375static void death_by_timeout(unsigned long ul_conntrack) 376{ 377 struct nf_conn *ct = (void *)ul_conntrack; 378 379 write_lock_bh(&nf_conntrack_lock); 380 /* Inside lock so preempt is disabled on module removal path. 381 * Otherwise we can get spurious warnings. */ 382 NF_CT_STAT_INC(delete_list); 383 clean_from_lists(ct); 384 write_unlock_bh(&nf_conntrack_lock); 385 nf_ct_put(ct); 386} 387 388struct nf_conntrack_tuple_hash * 389__nf_conntrack_find(const struct nf_conntrack_tuple *tuple, 390 const struct nf_conn *ignored_conntrack) 391{ 392 struct nf_conntrack_tuple_hash *h; 393 unsigned int hash = hash_conntrack(tuple); 394 395 list_for_each_entry(h, &nf_conntrack_hash[hash], list) { 396 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && 397 nf_ct_tuple_equal(tuple, &h->tuple)) { 398 NF_CT_STAT_INC(found); 399 return h; 400 } 401 NF_CT_STAT_INC(searched); 402 } 403 404 return NULL; 405} 406EXPORT_SYMBOL_GPL(__nf_conntrack_find); 407 408/* Find a connection corresponding to a tuple. */ 409struct nf_conntrack_tuple_hash * 410nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, 411 const struct nf_conn *ignored_conntrack) 412{ 413 struct nf_conntrack_tuple_hash *h; 414 415 read_lock_bh(&nf_conntrack_lock); 416 h = __nf_conntrack_find(tuple, ignored_conntrack); 417 if (h) 418 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); 419 read_unlock_bh(&nf_conntrack_lock); 420 421 return h; 422} 423EXPORT_SYMBOL_GPL(nf_conntrack_find_get); 424 425static void __nf_conntrack_hash_insert(struct nf_conn *ct, 426 unsigned int hash, 427 unsigned int repl_hash) 428{ 429 ct->id = ++nf_conntrack_next_id; 430 list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, 431 &nf_conntrack_hash[hash]); 432 list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, 433 &nf_conntrack_hash[repl_hash]); 434} 435 436void nf_conntrack_hash_insert(struct nf_conn *ct) 437{ 438 unsigned int hash, repl_hash; 439 440 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 441 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 442 443 write_lock_bh(&nf_conntrack_lock); 444 __nf_conntrack_hash_insert(ct, hash, repl_hash); 445 write_unlock_bh(&nf_conntrack_lock); 446} 447EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); 448 449/* Confirm a connection given skb; places it in hash table */ 450int 451__nf_conntrack_confirm(struct sk_buff **pskb) 452{ 453 unsigned int hash, repl_hash; 454 struct nf_conntrack_tuple_hash *h; 455 struct nf_conn *ct; 456 struct nf_conn_help *help; 457 enum ip_conntrack_info ctinfo; 458 459 ct = nf_ct_get(*pskb, &ctinfo); 460 461 /* ipt_REJECT uses nf_conntrack_attach to attach related 462 ICMP/TCP RST packets in other direction. Actual packet 463 which created connection will be IP_CT_NEW or for an 464 expected connection, IP_CT_RELATED. */ 465 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) 466 return NF_ACCEPT; 467 468 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 469 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 470 471 /* We're not in hash table, and we refuse to set up related 472 connections for unconfirmed conns. But packet copies and 473 REJECT will give spurious warnings here. */ 474 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ 475 476 /* No external references means noone else could have 477 confirmed us. */ 478 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 479 DEBUGP("Confirming conntrack %p\n", ct); 480 481 write_lock_bh(&nf_conntrack_lock); 482 483 /* See if there's one in the list already, including reverse: 484 NAT could have grabbed it without realizing, since we're 485 not in the hash. If there is, we lost race. */ 486 list_for_each_entry(h, &nf_conntrack_hash[hash], list) 487 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, 488 &h->tuple)) 489 goto out; 490 list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list) 491 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, 492 &h->tuple)) 493 goto out; 494 495 /* Remove from unconfirmed list */ 496 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 497 498 __nf_conntrack_hash_insert(ct, hash, repl_hash); 499 /* Timer relative to confirmation time, not original 500 setting time, otherwise we'd get timer wrap in 501 weird delay cases. */ 502 ct->timeout.expires += jiffies; 503 add_timer(&ct->timeout); 504 atomic_inc(&ct->ct_general.use); 505 set_bit(IPS_CONFIRMED_BIT, &ct->status); 506 NF_CT_STAT_INC(insert); 507 write_unlock_bh(&nf_conntrack_lock); 508 help = nfct_help(ct); 509 if (help && help->helper) 510 nf_conntrack_event_cache(IPCT_HELPER, *pskb); 511#ifdef CONFIG_NF_NAT_NEEDED 512 if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || 513 test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) 514 nf_conntrack_event_cache(IPCT_NATINFO, *pskb); 515#endif 516 nf_conntrack_event_cache(master_ct(ct) ? 517 IPCT_RELATED : IPCT_NEW, *pskb); 518 return NF_ACCEPT; 519 520out: 521 NF_CT_STAT_INC(insert_failed); 522 write_unlock_bh(&nf_conntrack_lock); 523 return NF_DROP; 524} 525EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); 526 527/* Returns true if a connection correspondings to the tuple (required 528 for NAT). */ 529int 530nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, 531 const struct nf_conn *ignored_conntrack) 532{ 533 struct nf_conntrack_tuple_hash *h; 534 535 read_lock_bh(&nf_conntrack_lock); 536 h = __nf_conntrack_find(tuple, ignored_conntrack); 537 read_unlock_bh(&nf_conntrack_lock); 538 539 return h != NULL; 540} 541EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); 542 543/* There's a small race here where we may free a just-assured 544 connection. Too bad: we're in trouble anyway. */ 545static int early_drop(struct list_head *chain) 546{ 547 /* Traverse backwards: gives us oldest, which is roughly LRU */ 548 struct nf_conntrack_tuple_hash *h; 549 struct nf_conn *ct = NULL, *tmp; 550 int dropped = 0; 551 552 read_lock_bh(&nf_conntrack_lock); 553 list_for_each_entry_reverse(h, chain, list) { 554 tmp = nf_ct_tuplehash_to_ctrack(h); 555 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { 556 ct = tmp; 557 atomic_inc(&ct->ct_general.use); 558 break; 559 } 560 } 561 read_unlock_bh(&nf_conntrack_lock); 562 563 if (!ct) 564 return dropped; 565 566 if (del_timer(&ct->timeout)) { 567 death_by_timeout((unsigned long)ct); 568 dropped = 1; 569 NF_CT_STAT_INC_ATOMIC(early_drop); 570 } 571 nf_ct_put(ct); 572 return dropped; 573} 574 575static struct nf_conn * 576__nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 577 const struct nf_conntrack_tuple *repl, 578 const struct nf_conntrack_l3proto *l3proto, 579 u_int32_t features) 580{ 581 struct nf_conn *conntrack = NULL; 582 struct nf_conntrack_helper *helper; 583 584 if (unlikely(!nf_conntrack_hash_rnd_initted)) { 585 get_random_bytes(&nf_conntrack_hash_rnd, 4); 586 nf_conntrack_hash_rnd_initted = 1; 587 } 588 589 /* We don't want any race condition at early drop stage */ 590 atomic_inc(&nf_conntrack_count); 591 592 if (nf_conntrack_max 593 && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { 594 unsigned int hash = hash_conntrack(orig); 595 /* Try dropping from this hash chain. */ 596 if (!early_drop(&nf_conntrack_hash[hash])) { 597 atomic_dec(&nf_conntrack_count); 598 if (net_ratelimit()) 599 printk(KERN_WARNING 600 "nf_conntrack: table full, dropping" 601 " packet.\n"); 602 return ERR_PTR(-ENOMEM); 603 } 604 } 605 606 /* find features needed by this conntrack. */ 607 features |= l3proto->get_features(orig); 608 609 /* FIXME: protect helper list per RCU */ 610 read_lock_bh(&nf_conntrack_lock); 611 helper = __nf_ct_helper_find(repl); 612 /* NAT might want to assign a helper later */ 613 if (helper || features & NF_CT_F_NAT) 614 features |= NF_CT_F_HELP; 615 read_unlock_bh(&nf_conntrack_lock); 616 617 DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); 618 619 read_lock_bh(&nf_ct_cache_lock); 620 621 if (unlikely(!nf_ct_cache[features].use)) { 622 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", 623 features); 624 goto out; 625 } 626 627 conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); 628 if (conntrack == NULL) { 629 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); 630 goto out; 631 } 632 633 memset(conntrack, 0, nf_ct_cache[features].size); 634 conntrack->features = features; 635 atomic_set(&conntrack->ct_general.use, 1); 636 conntrack->ct_general.destroy = destroy_conntrack; 637 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; 638 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; 639 /* Don't set timer yet: wait for confirmation */ 640 init_timer(&conntrack->timeout); 641 conntrack->timeout.data = (unsigned long)conntrack; 642 conntrack->timeout.function = death_by_timeout; 643 read_unlock_bh(&nf_ct_cache_lock); 644 645 return conntrack; 646out: 647 read_unlock_bh(&nf_ct_cache_lock); 648 atomic_dec(&nf_conntrack_count); 649 return conntrack; 650} 651 652struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 653 const struct nf_conntrack_tuple *repl) 654{ 655 struct nf_conntrack_l3proto *l3proto; 656 struct nf_conn *ct; 657 658 rcu_read_lock(); 659 l3proto = __nf_ct_l3proto_find(orig->src.l3num); 660 ct = __nf_conntrack_alloc(orig, repl, l3proto, 0); 661 rcu_read_unlock(); 662 663 return ct; 664} 665EXPORT_SYMBOL_GPL(nf_conntrack_alloc); 666 667void nf_conntrack_free(struct nf_conn *conntrack) 668{ 669 u_int32_t features = conntrack->features; 670 NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); 671 DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, 672 conntrack); 673 kmem_cache_free(nf_ct_cache[features].cachep, conntrack); 674 atomic_dec(&nf_conntrack_count); 675} 676EXPORT_SYMBOL_GPL(nf_conntrack_free); 677 678/* Allocate a new conntrack: we return -ENOMEM if classification 679 failed due to stress. Otherwise it really is unclassifiable. */ 680static struct nf_conntrack_tuple_hash * 681init_conntrack(const struct nf_conntrack_tuple *tuple, 682 struct nf_conntrack_l3proto *l3proto, 683 struct nf_conntrack_l4proto *l4proto, 684 struct sk_buff *skb, 685 unsigned int dataoff) 686{ 687 struct nf_conn *conntrack; 688 struct nf_conntrack_tuple repl_tuple; 689 struct nf_conntrack_expect *exp; 690 u_int32_t features = 0; 691 692 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { 693 DEBUGP("Can't invert tuple.\n"); 694 return NULL; 695 } 696 697 read_lock_bh(&nf_conntrack_lock); 698 exp = __nf_conntrack_expect_find(tuple); 699 if (exp && exp->helper) 700 features = NF_CT_F_HELP; 701 read_unlock_bh(&nf_conntrack_lock); 702 703 conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features); 704 if (conntrack == NULL || IS_ERR(conntrack)) { 705 DEBUGP("Can't allocate conntrack.\n"); 706 return (struct nf_conntrack_tuple_hash *)conntrack; 707 } 708 709 if (!l4proto->new(conntrack, skb, dataoff)) { 710 nf_conntrack_free(conntrack); 711 DEBUGP("init conntrack: can't track with proto module\n"); 712 return NULL; 713 } 714 715 write_lock_bh(&nf_conntrack_lock); 716 exp = find_expectation(tuple); 717 718 if (exp) { 719 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", 720 conntrack, exp); 721 /* Welcome, Mr. Bond. We've been expecting you... */ 722 __set_bit(IPS_EXPECTED_BIT, &conntrack->status); 723 conntrack->master = exp->master; 724 if (exp->helper) 725 nfct_help(conntrack)->helper = exp->helper; 726#ifdef CONFIG_NF_CONNTRACK_MARK 727 conntrack->mark = exp->master->mark; 728#endif 729#ifdef CONFIG_NF_CONNTRACK_SECMARK 730 conntrack->secmark = exp->master->secmark; 731#endif 732 nf_conntrack_get(&conntrack->master->ct_general); 733 NF_CT_STAT_INC(expect_new); 734 } else { 735 struct nf_conn_help *help = nfct_help(conntrack); 736 737 if (help) 738 help->helper = __nf_ct_helper_find(&repl_tuple); 739 NF_CT_STAT_INC(new); 740 } 741 742 /* Overload tuple linked list to put us in unconfirmed list. */ 743 list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); 744 745 write_unlock_bh(&nf_conntrack_lock); 746 747 if (exp) { 748 if (exp->expectfn) 749 exp->expectfn(conntrack, exp); 750 nf_conntrack_expect_put(exp); 751 } 752 753 return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; 754} 755 756/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ 757static inline struct nf_conn * 758resolve_normal_ct(struct sk_buff *skb, 759 unsigned int dataoff, 760 u_int16_t l3num, 761 u_int8_t protonum, 762 struct nf_conntrack_l3proto *l3proto, 763 struct nf_conntrack_l4proto *l4proto, 764 int *set_reply, 765 enum ip_conntrack_info *ctinfo) 766{ 767 struct nf_conntrack_tuple tuple; 768 struct nf_conntrack_tuple_hash *h; 769 struct nf_conn *ct; 770 771 if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), 772 dataoff, l3num, protonum, &tuple, l3proto, 773 l4proto)) { 774 DEBUGP("resolve_normal_ct: Can't get tuple\n"); 775 return NULL; 776 } 777 778 /* look for tuple match */ 779 h = nf_conntrack_find_get(&tuple, NULL); 780 if (!h) { 781 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff); 782 if (!h) 783 return NULL; 784 if (IS_ERR(h)) 785 return (void *)h; 786 } 787 ct = nf_ct_tuplehash_to_ctrack(h); 788 789 /* It exists; we have (non-exclusive) reference. */ 790 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { 791 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; 792 /* Please set reply bit if this packet OK */ 793 *set_reply = 1; 794 } else { 795 /* Once we've had two way comms, always ESTABLISHED. */ 796 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { 797 DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); 798 *ctinfo = IP_CT_ESTABLISHED; 799 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { 800 DEBUGP("nf_conntrack_in: related packet for %p\n", ct); 801 *ctinfo = IP_CT_RELATED; 802 } else { 803 DEBUGP("nf_conntrack_in: new packet for %p\n", ct); 804 *ctinfo = IP_CT_NEW; 805 } 806 *set_reply = 0; 807 } 808 skb->nfct = &ct->ct_general; 809 skb->nfctinfo = *ctinfo; 810 return ct; 811} 812 813unsigned int 814nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) 815{ 816 struct nf_conn *ct; 817 enum ip_conntrack_info ctinfo; 818 struct nf_conntrack_l3proto *l3proto; 819 struct nf_conntrack_l4proto *l4proto; 820 unsigned int dataoff; 821 u_int8_t protonum; 822 int set_reply = 0; 823 int ret; 824 825 /* Previously seen (loopback or untracked)? Ignore. */ 826 if ((*pskb)->nfct) { 827 NF_CT_STAT_INC_ATOMIC(ignore); 828 return NF_ACCEPT; 829 } 830 831 /* rcu_read_lock()ed by nf_hook_slow */ 832 l3proto = __nf_ct_l3proto_find((u_int16_t)pf); 833 834 if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { 835 DEBUGP("not prepared to track yet or error occured\n"); 836 return -ret; 837 } 838 839 l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum); 840 841 /* It may be an special packet, error, unclean... 842 * inverse of the return code tells to the netfilter 843 * core what to do with the packet. */ 844 if (l4proto->error != NULL && 845 (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { 846 NF_CT_STAT_INC_ATOMIC(error); 847 NF_CT_STAT_INC_ATOMIC(invalid); 848 return -ret; 849 } 850 851 ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto, 852 &set_reply, &ctinfo); 853 if (!ct) { 854 /* Not valid part of a connection */ 855 NF_CT_STAT_INC_ATOMIC(invalid); 856 return NF_ACCEPT; 857 } 858 859 if (IS_ERR(ct)) { 860 /* Too stressed to deal. */ 861 NF_CT_STAT_INC_ATOMIC(drop); 862 return NF_DROP; 863 } 864 865 NF_CT_ASSERT((*pskb)->nfct); 866 867 ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); 868 if (ret < 0) { 869 /* Invalid: inverse of the return code tells 870 * the netfilter core what to do */ 871 DEBUGP("nf_conntrack_in: Can't track with proto module\n"); 872 nf_conntrack_put((*pskb)->nfct); 873 (*pskb)->nfct = NULL; 874 NF_CT_STAT_INC_ATOMIC(invalid); 875 return -ret; 876 } 877 878 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) 879 nf_conntrack_event_cache(IPCT_STATUS, *pskb); 880 881 return ret; 882} 883EXPORT_SYMBOL_GPL(nf_conntrack_in); 884 885int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, 886 const struct nf_conntrack_tuple *orig) 887{ 888 int ret; 889 890 rcu_read_lock(); 891 ret = nf_ct_invert_tuple(inverse, orig, 892 __nf_ct_l3proto_find(orig->src.l3num), 893 __nf_ct_l4proto_find(orig->src.l3num, 894 orig->dst.protonum)); 895 rcu_read_unlock(); 896 return ret; 897} 898EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); 899 900/* Alter reply tuple (maybe alter helper). This is for NAT, and is 901 implicitly racy: see __nf_conntrack_confirm */ 902void nf_conntrack_alter_reply(struct nf_conn *ct, 903 const struct nf_conntrack_tuple *newreply) 904{ 905 struct nf_conn_help *help = nfct_help(ct); 906 907 write_lock_bh(&nf_conntrack_lock); 908 /* Should be unconfirmed, so not in hash table yet */ 909 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 910 911 DEBUGP("Altering reply tuple of %p to ", ct); 912 NF_CT_DUMP_TUPLE(newreply); 913 914 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; 915 if (!ct->master && help && help->expecting == 0) 916 help->helper = __nf_ct_helper_find(newreply); 917 write_unlock_bh(&nf_conntrack_lock); 918} 919EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); 920 921/* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ 922void __nf_ct_refresh_acct(struct nf_conn *ct, 923 enum ip_conntrack_info ctinfo, 924 const struct sk_buff *skb, 925 unsigned long extra_jiffies, 926 int do_acct) 927{ 928 int event = 0; 929 930 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); 931 NF_CT_ASSERT(skb); 932 933 write_lock_bh(&nf_conntrack_lock); 934 935 /* Only update if this is not a fixed timeout */ 936 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { 937 write_unlock_bh(&nf_conntrack_lock); 938 return; 939 } 940 941 /* If not in hash table, timer will not be active yet */ 942 if (!nf_ct_is_confirmed(ct)) { 943 ct->timeout.expires = extra_jiffies; 944 event = IPCT_REFRESH; 945 } else { 946 unsigned long newtime = jiffies + extra_jiffies; 947 948 /* Only update the timeout if the new timeout is at least 949 HZ jiffies from the old timeout. Need del_timer for race 950 avoidance (may already be dying). */ 951 if (newtime - ct->timeout.expires >= HZ 952 && del_timer(&ct->timeout)) { 953 ct->timeout.expires = newtime; 954 add_timer(&ct->timeout); 955 event = IPCT_REFRESH; 956 } 957 } 958 959#ifdef CONFIG_NF_CT_ACCT 960 if (do_acct) { 961 ct->counters[CTINFO2DIR(ctinfo)].packets++; 962 ct->counters[CTINFO2DIR(ctinfo)].bytes += 963 skb->len - (unsigned int)(skb->nh.raw - skb->data); 964 965 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) 966 || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) 967 event |= IPCT_COUNTER_FILLING; 968 } 969#endif 970 971 write_unlock_bh(&nf_conntrack_lock); 972 973 /* must be unlocked when calling event cache */ 974 if (event) 975 nf_conntrack_event_cache(event, skb); 976} 977EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); 978 979#if defined(CONFIG_NF_CT_NETLINK) || \ 980 defined(CONFIG_NF_CT_NETLINK_MODULE) 981 982#include <linux/netfilter/nfnetlink.h> 983#include <linux/netfilter/nfnetlink_conntrack.h> 984#include <linux/mutex.h> 985 986 987/* Generic function for tcp/udp/sctp/dccp and alike. This needs to be 988 * in ip_conntrack_core, since we don't want the protocols to autoload 989 * or depend on ctnetlink */ 990int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, 991 const struct nf_conntrack_tuple *tuple) 992{ 993 NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), 994 &tuple->src.u.tcp.port); 995 NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), 996 &tuple->dst.u.tcp.port); 997 return 0; 998 999nfattr_failure: 1000 return -1; 1001} 1002EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr); 1003 1004static const size_t cta_min_proto[CTA_PROTO_MAX] = { 1005 [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), 1006 [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) 1007}; 1008 1009int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], 1010 struct nf_conntrack_tuple *t) 1011{ 1012 if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) 1013 return -EINVAL; 1014 1015 if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) 1016 return -EINVAL; 1017 1018 t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); 1019 t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); 1020 1021 return 0; 1022} 1023EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple); 1024#endif 1025 1026/* Used by ipt_REJECT and ip6t_REJECT. */ 1027void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) 1028{ 1029 struct nf_conn *ct; 1030 enum ip_conntrack_info ctinfo; 1031 1032 /* This ICMP is in reverse direction to the packet which caused it */ 1033 ct = nf_ct_get(skb, &ctinfo); 1034 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) 1035 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; 1036 else 1037 ctinfo = IP_CT_RELATED; 1038 1039 /* Attach to new skbuff, and increment count */ 1040 nskb->nfct = &ct->ct_general; 1041 nskb->nfctinfo = ctinfo; 1042 nf_conntrack_get(nskb->nfct); 1043} 1044EXPORT_SYMBOL_GPL(__nf_conntrack_attach); 1045 1046static inline int 1047do_iter(const struct nf_conntrack_tuple_hash *i, 1048 int (*iter)(struct nf_conn *i, void *data), 1049 void *data) 1050{ 1051 return iter(nf_ct_tuplehash_to_ctrack(i), data); 1052} 1053 1054/* Bring out ya dead! */ 1055static struct nf_conn * 1056get_next_corpse(int (*iter)(struct nf_conn *i, void *data), 1057 void *data, unsigned int *bucket) 1058{ 1059 struct nf_conntrack_tuple_hash *h; 1060 struct nf_conn *ct; 1061 1062 write_lock_bh(&nf_conntrack_lock); 1063 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { 1064 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) { 1065 ct = nf_ct_tuplehash_to_ctrack(h); 1066 if (iter(ct, data)) 1067 goto found; 1068 } 1069 } 1070 list_for_each_entry(h, &unconfirmed, list) { 1071 ct = nf_ct_tuplehash_to_ctrack(h); 1072 if (iter(ct, data)) 1073 goto found; 1074 } 1075 write_unlock_bh(&nf_conntrack_lock); 1076 return NULL; 1077found: 1078 atomic_inc(&ct->ct_general.use); 1079 write_unlock_bh(&nf_conntrack_lock); 1080 return ct; 1081} 1082 1083void 1084nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) 1085{ 1086 struct nf_conn *ct; 1087 unsigned int bucket = 0; 1088 1089 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { 1090 /* Time to push up daises... */ 1091 if (del_timer(&ct->timeout)) 1092 death_by_timeout((unsigned long)ct); 1093 /* ... else the timer will get him soon. */ 1094 1095 nf_ct_put(ct); 1096 } 1097} 1098EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); 1099 1100static int kill_all(struct nf_conn *i, void *data) 1101{ 1102 return 1; 1103} 1104 1105static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) 1106{ 1107 if (vmalloced) 1108 vfree(hash); 1109 else 1110 free_pages((unsigned long)hash, 1111 get_order(sizeof(struct list_head) * size)); 1112} 1113 1114void nf_conntrack_flush(void) 1115{ 1116 nf_ct_iterate_cleanup(kill_all, NULL); 1117} 1118EXPORT_SYMBOL_GPL(nf_conntrack_flush); 1119 1120/* Mishearing the voices in his head, our hero wonders how he's 1121 supposed to kill the mall. */ 1122void nf_conntrack_cleanup(void) 1123{ 1124 int i; 1125 1126 rcu_assign_pointer(ip_ct_attach, NULL); 1127 1128 /* This makes sure all current packets have passed through 1129 netfilter framework. Roll on, two-stage module 1130 delete... */ 1131 synchronize_net(); 1132 1133 nf_ct_event_cache_flush(); 1134 i_see_dead_people: 1135 nf_conntrack_flush(); 1136 if (atomic_read(&nf_conntrack_count) != 0) { 1137 schedule(); 1138 goto i_see_dead_people; 1139 } 1140 /* wait until all references to nf_conntrack_untracked are dropped */ 1141 while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) 1142 schedule(); 1143 1144 for (i = 0; i < NF_CT_F_NUM; i++) { 1145 if (nf_ct_cache[i].use == 0) 1146 continue; 1147 1148 NF_CT_ASSERT(nf_ct_cache[i].use == 1); 1149 nf_ct_cache[i].use = 1; 1150 nf_conntrack_unregister_cache(i); 1151 } 1152 kmem_cache_destroy(nf_conntrack_expect_cachep); 1153 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1154 nf_conntrack_htable_size); 1155 1156 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic); 1157 1158 /* free l3proto protocol tables */ 1159 for (i = 0; i < PF_MAX; i++) 1160 if (nf_ct_protos[i]) { 1161 kfree(nf_ct_protos[i]); 1162 nf_ct_protos[i] = NULL; 1163 } 1164} 1165 1166static struct list_head *alloc_hashtable(int size, int *vmalloced) 1167{ 1168 struct list_head *hash; 1169 unsigned int i; 1170 1171 *vmalloced = 0; 1172 hash = (void*)__get_free_pages(GFP_KERNEL, 1173 get_order(sizeof(struct list_head) 1174 * size)); 1175 if (!hash) { 1176 *vmalloced = 1; 1177 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); 1178 hash = vmalloc(sizeof(struct list_head) * size); 1179 } 1180 1181 if (hash) 1182 for (i = 0; i < size; i++) 1183 INIT_LIST_HEAD(&hash[i]); 1184 1185 return hash; 1186} 1187 1188int set_hashsize(const char *val, struct kernel_param *kp) 1189{ 1190 int i, bucket, hashsize, vmalloced; 1191 int old_vmalloced, old_size; 1192 int rnd; 1193 struct list_head *hash, *old_hash; 1194 struct nf_conntrack_tuple_hash *h; 1195 1196 /* On boot, we can set this without any fancy locking. */ 1197 if (!nf_conntrack_htable_size) 1198 return param_set_uint(val, kp); 1199 1200 hashsize = simple_strtol(val, NULL, 0); 1201 if (!hashsize) 1202 return -EINVAL; 1203 1204 hash = alloc_hashtable(hashsize, &vmalloced); 1205 if (!hash) 1206 return -ENOMEM; 1207 1208 /* We have to rehahs for the new table anyway, so we also can 1209 * use a newrandom seed */ 1210 get_random_bytes(&rnd, 4); 1211 1212 write_lock_bh(&nf_conntrack_lock); 1213 for (i = 0; i < nf_conntrack_htable_size; i++) { 1214 while (!list_empty(&nf_conntrack_hash[i])) { 1215 h = list_entry(nf_conntrack_hash[i].next, 1216 struct nf_conntrack_tuple_hash, list); 1217 list_del(&h->list); 1218 bucket = __hash_conntrack(&h->tuple, hashsize, rnd); 1219 list_add_tail(&h->list, &hash[bucket]); 1220 } 1221 } 1222 old_size = nf_conntrack_htable_size; 1223 old_vmalloced = nf_conntrack_vmalloc; 1224 old_hash = nf_conntrack_hash; 1225 1226 nf_conntrack_htable_size = hashsize; 1227 nf_conntrack_vmalloc = vmalloced; 1228 nf_conntrack_hash = hash; 1229 nf_conntrack_hash_rnd = rnd; 1230 write_unlock_bh(&nf_conntrack_lock); 1231 1232 free_conntrack_hash(old_hash, old_vmalloced, old_size); 1233 return 0; 1234} 1235 1236module_param_call(hashsize, set_hashsize, param_get_uint, 1237 &nf_conntrack_htable_size, 0600); 1238 1239int __init nf_conntrack_init(void) 1240{ 1241 unsigned int i; 1242 int ret; 1243 1244 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB 1245 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ 1246 if (!nf_conntrack_htable_size) { 1247 nf_conntrack_htable_size 1248 = (((num_physpages << PAGE_SHIFT) / 16384) 1249 / sizeof(struct list_head)); 1250 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) 1251 nf_conntrack_htable_size = 8192; 1252 if (nf_conntrack_htable_size < 16) 1253 nf_conntrack_htable_size = 16; 1254 } 1255 nf_conntrack_max = 8 * nf_conntrack_htable_size; 1256 1257 printk("nf_conntrack version %s (%u buckets, %d max)\n", 1258 NF_CONNTRACK_VERSION, nf_conntrack_htable_size, 1259 nf_conntrack_max); 1260 1261 nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, 1262 &nf_conntrack_vmalloc); 1263 if (!nf_conntrack_hash) { 1264 printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); 1265 goto err_out; 1266 } 1267 1268 ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", 1269 sizeof(struct nf_conn)); 1270 if (ret < 0) { 1271 printk(KERN_ERR "Unable to create nf_conn slab cache\n"); 1272 goto err_free_hash; 1273 } 1274 1275 nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", 1276 sizeof(struct nf_conntrack_expect), 1277 0, 0, NULL, NULL); 1278 if (!nf_conntrack_expect_cachep) { 1279 printk(KERN_ERR "Unable to create nf_expect slab cache\n"); 1280 goto err_free_conntrack_slab; 1281 } 1282 1283 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic); 1284 if (ret < 0) 1285 goto out_free_expect_slab; 1286 1287 /* Don't NEED lock here, but good form anyway. */ 1288 write_lock_bh(&nf_conntrack_lock); 1289 for (i = 0; i < AF_MAX; i++) 1290 nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic; 1291 write_unlock_bh(&nf_conntrack_lock); 1292 1293 /* For use by REJECT target */ 1294 rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach); 1295 1296 /* Set up fake conntrack: 1297 - to never be deleted, not in any hashes */ 1298 atomic_set(&nf_conntrack_untracked.ct_general.use, 1); 1299 /* - and look it like as a confirmed connection */ 1300 set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); 1301 1302 return ret; 1303 1304out_free_expect_slab: 1305 kmem_cache_destroy(nf_conntrack_expect_cachep); 1306err_free_conntrack_slab: 1307 nf_conntrack_unregister_cache(NF_CT_F_BASIC); 1308err_free_hash: 1309 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1310 nf_conntrack_htable_size); 1311err_out: 1312 return -ENOMEM; 1313} 1314