nf_conntrack_core.c revision f09943fefe6b702e40893d35b4f10fd1064037fe
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 65DEFINE_RWLOCK(nf_conntrack_lock); 66 67/* nf_conntrack_standalone needs this */ 68atomic_t nf_conntrack_count = ATOMIC_INIT(0); 69EXPORT_SYMBOL_GPL(nf_conntrack_count); 70 71void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; 72unsigned int nf_conntrack_htable_size __read_mostly; 73int nf_conntrack_max __read_mostly; 74EXPORT_SYMBOL_GPL(nf_conntrack_max); 75struct list_head *nf_conntrack_hash __read_mostly; 76struct nf_conn nf_conntrack_untracked __read_mostly; 77unsigned int nf_ct_log_invalid __read_mostly; 78LIST_HEAD(unconfirmed); 79static int nf_conntrack_vmalloc __read_mostly; 80 81static unsigned int nf_conntrack_next_id; 82 83DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); 84EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); 85 86/* 87 * This scheme offers various size of "struct nf_conn" dependent on 88 * features(helper, nat, ...) 89 */ 90 91#define NF_CT_FEATURES_NAMELEN 256 92static struct { 93 /* name of slab cache. printed in /proc/slabinfo */ 94 char *name; 95 96 /* size of slab cache */ 97 size_t size; 98 99 /* slab cache pointer */ 100 kmem_cache_t *cachep; 101 102 /* allocated slab cache + modules which uses this slab cache */ 103 int use; 104 105} nf_ct_cache[NF_CT_F_NUM]; 106 107/* protect members of nf_ct_cache except of "use" */ 108DEFINE_RWLOCK(nf_ct_cache_lock); 109 110/* This avoids calling kmem_cache_create() with same name simultaneously */ 111static DEFINE_MUTEX(nf_ct_cache_mutex); 112 113static int nf_conntrack_hash_rnd_initted; 114static unsigned int nf_conntrack_hash_rnd; 115 116static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, 117 unsigned int size, unsigned int rnd) 118{ 119 unsigned int a, b; 120 a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), 121 ((tuple->src.l3num) << 16) | tuple->dst.protonum); 122 b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), 123 (tuple->src.u.all << 16) | tuple->dst.u.all); 124 125 return jhash_2words(a, b, rnd) % size; 126} 127 128static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) 129{ 130 return __hash_conntrack(tuple, nf_conntrack_htable_size, 131 nf_conntrack_hash_rnd); 132} 133 134int nf_conntrack_register_cache(u_int32_t features, const char *name, 135 size_t size) 136{ 137 int ret = 0; 138 char *cache_name; 139 kmem_cache_t *cachep; 140 141 DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", 142 features, name, size); 143 144 if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { 145 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", 146 features); 147 return -EINVAL; 148 } 149 150 mutex_lock(&nf_ct_cache_mutex); 151 152 write_lock_bh(&nf_ct_cache_lock); 153 /* e.g: multiple helpers are loaded */ 154 if (nf_ct_cache[features].use > 0) { 155 DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); 156 if ((!strncmp(nf_ct_cache[features].name, name, 157 NF_CT_FEATURES_NAMELEN)) 158 && nf_ct_cache[features].size == size) { 159 DEBUGP("nf_conntrack_register_cache: reusing.\n"); 160 nf_ct_cache[features].use++; 161 ret = 0; 162 } else 163 ret = -EBUSY; 164 165 write_unlock_bh(&nf_ct_cache_lock); 166 mutex_unlock(&nf_ct_cache_mutex); 167 return ret; 168 } 169 write_unlock_bh(&nf_ct_cache_lock); 170 171 /* 172 * The memory space for name of slab cache must be alive until 173 * cache is destroyed. 174 */ 175 cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); 176 if (cache_name == NULL) { 177 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); 178 ret = -ENOMEM; 179 goto out_up_mutex; 180 } 181 182 if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) 183 >= NF_CT_FEATURES_NAMELEN) { 184 printk("nf_conntrack_register_cache: name too long\n"); 185 ret = -EINVAL; 186 goto out_free_name; 187 } 188 189 cachep = kmem_cache_create(cache_name, size, 0, 0, 190 NULL, NULL); 191 if (!cachep) { 192 printk("nf_conntrack_register_cache: Can't create slab cache " 193 "for the features = 0x%x\n", features); 194 ret = -ENOMEM; 195 goto out_free_name; 196 } 197 198 write_lock_bh(&nf_ct_cache_lock); 199 nf_ct_cache[features].use = 1; 200 nf_ct_cache[features].size = size; 201 nf_ct_cache[features].cachep = cachep; 202 nf_ct_cache[features].name = cache_name; 203 write_unlock_bh(&nf_ct_cache_lock); 204 205 goto out_up_mutex; 206 207out_free_name: 208 kfree(cache_name); 209out_up_mutex: 210 mutex_unlock(&nf_ct_cache_mutex); 211 return ret; 212} 213 214/* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ 215void nf_conntrack_unregister_cache(u_int32_t features) 216{ 217 kmem_cache_t *cachep; 218 char *name; 219 220 /* 221 * This assures that kmem_cache_create() isn't called before destroying 222 * slab cache. 223 */ 224 DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); 225 mutex_lock(&nf_ct_cache_mutex); 226 227 write_lock_bh(&nf_ct_cache_lock); 228 if (--nf_ct_cache[features].use > 0) { 229 write_unlock_bh(&nf_ct_cache_lock); 230 mutex_unlock(&nf_ct_cache_mutex); 231 return; 232 } 233 cachep = nf_ct_cache[features].cachep; 234 name = nf_ct_cache[features].name; 235 nf_ct_cache[features].cachep = NULL; 236 nf_ct_cache[features].name = NULL; 237 nf_ct_cache[features].size = 0; 238 write_unlock_bh(&nf_ct_cache_lock); 239 240 synchronize_net(); 241 242 kmem_cache_destroy(cachep); 243 kfree(name); 244 245 mutex_unlock(&nf_ct_cache_mutex); 246} 247 248int 249nf_ct_get_tuple(const struct sk_buff *skb, 250 unsigned int nhoff, 251 unsigned int dataoff, 252 u_int16_t l3num, 253 u_int8_t protonum, 254 struct nf_conntrack_tuple *tuple, 255 const struct nf_conntrack_l3proto *l3proto, 256 const struct nf_conntrack_l4proto *l4proto) 257{ 258 NF_CT_TUPLE_U_BLANK(tuple); 259 260 tuple->src.l3num = l3num; 261 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) 262 return 0; 263 264 tuple->dst.protonum = protonum; 265 tuple->dst.dir = IP_CT_DIR_ORIGINAL; 266 267 return l4proto->pkt_to_tuple(skb, dataoff, tuple); 268} 269 270int 271nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, 272 const struct nf_conntrack_tuple *orig, 273 const struct nf_conntrack_l3proto *l3proto, 274 const struct nf_conntrack_l4proto *l4proto) 275{ 276 NF_CT_TUPLE_U_BLANK(inverse); 277 278 inverse->src.l3num = orig->src.l3num; 279 if (l3proto->invert_tuple(inverse, orig) == 0) 280 return 0; 281 282 inverse->dst.dir = !orig->dst.dir; 283 284 inverse->dst.protonum = orig->dst.protonum; 285 return l4proto->invert_tuple(inverse, orig); 286} 287 288static void 289clean_from_lists(struct nf_conn *ct) 290{ 291 DEBUGP("clean_from_lists(%p)\n", ct); 292 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 293 list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); 294 295 /* Destroy all pending expectations */ 296 nf_ct_remove_expectations(ct); 297} 298 299static void 300destroy_conntrack(struct nf_conntrack *nfct) 301{ 302 struct nf_conn *ct = (struct nf_conn *)nfct; 303 struct nf_conn_help *help = nfct_help(ct); 304 struct nf_conntrack_l3proto *l3proto; 305 struct nf_conntrack_l4proto *l4proto; 306 307 DEBUGP("destroy_conntrack(%p)\n", ct); 308 NF_CT_ASSERT(atomic_read(&nfct->use) == 0); 309 NF_CT_ASSERT(!timer_pending(&ct->timeout)); 310 311 nf_conntrack_event(IPCT_DESTROY, ct); 312 set_bit(IPS_DYING_BIT, &ct->status); 313 314 if (help && help->helper && help->helper->destroy) 315 help->helper->destroy(ct); 316 317 /* To make sure we don't get any weird locking issues here: 318 * destroy_conntrack() MUST NOT be called with a write lock 319 * to nf_conntrack_lock!!! -HW */ 320 l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); 321 if (l3proto && l3proto->destroy) 322 l3proto->destroy(ct); 323 324 l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); 325 if (l4proto && l4proto->destroy) 326 l4proto->destroy(ct); 327 328 if (nf_conntrack_destroyed) 329 nf_conntrack_destroyed(ct); 330 331 write_lock_bh(&nf_conntrack_lock); 332 /* Expectations will have been removed in clean_from_lists, 333 * except TFTP can create an expectation on the first packet, 334 * before connection is in the list, so we need to clean here, 335 * too. */ 336 nf_ct_remove_expectations(ct); 337 338 /* We overload first tuple to link into unconfirmed list. */ 339 if (!nf_ct_is_confirmed(ct)) { 340 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); 341 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 342 } 343 344 NF_CT_STAT_INC(delete); 345 write_unlock_bh(&nf_conntrack_lock); 346 347 if (ct->master) 348 nf_ct_put(ct->master); 349 350 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); 351 nf_conntrack_free(ct); 352} 353 354static void death_by_timeout(unsigned long ul_conntrack) 355{ 356 struct nf_conn *ct = (void *)ul_conntrack; 357 358 write_lock_bh(&nf_conntrack_lock); 359 /* Inside lock so preempt is disabled on module removal path. 360 * Otherwise we can get spurious warnings. */ 361 NF_CT_STAT_INC(delete_list); 362 clean_from_lists(ct); 363 write_unlock_bh(&nf_conntrack_lock); 364 nf_ct_put(ct); 365} 366 367struct nf_conntrack_tuple_hash * 368__nf_conntrack_find(const struct nf_conntrack_tuple *tuple, 369 const struct nf_conn *ignored_conntrack) 370{ 371 struct nf_conntrack_tuple_hash *h; 372 unsigned int hash = hash_conntrack(tuple); 373 374 list_for_each_entry(h, &nf_conntrack_hash[hash], list) { 375 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && 376 nf_ct_tuple_equal(tuple, &h->tuple)) { 377 NF_CT_STAT_INC(found); 378 return h; 379 } 380 NF_CT_STAT_INC(searched); 381 } 382 383 return NULL; 384} 385 386/* Find a connection corresponding to a tuple. */ 387struct nf_conntrack_tuple_hash * 388nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, 389 const struct nf_conn *ignored_conntrack) 390{ 391 struct nf_conntrack_tuple_hash *h; 392 393 read_lock_bh(&nf_conntrack_lock); 394 h = __nf_conntrack_find(tuple, ignored_conntrack); 395 if (h) 396 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); 397 read_unlock_bh(&nf_conntrack_lock); 398 399 return h; 400} 401 402static void __nf_conntrack_hash_insert(struct nf_conn *ct, 403 unsigned int hash, 404 unsigned int repl_hash) 405{ 406 ct->id = ++nf_conntrack_next_id; 407 list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, 408 &nf_conntrack_hash[hash]); 409 list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, 410 &nf_conntrack_hash[repl_hash]); 411} 412 413void nf_conntrack_hash_insert(struct nf_conn *ct) 414{ 415 unsigned int hash, repl_hash; 416 417 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 418 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 419 420 write_lock_bh(&nf_conntrack_lock); 421 __nf_conntrack_hash_insert(ct, hash, repl_hash); 422 write_unlock_bh(&nf_conntrack_lock); 423} 424 425/* Confirm a connection given skb; places it in hash table */ 426int 427__nf_conntrack_confirm(struct sk_buff **pskb) 428{ 429 unsigned int hash, repl_hash; 430 struct nf_conntrack_tuple_hash *h; 431 struct nf_conn *ct; 432 struct nf_conn_help *help; 433 enum ip_conntrack_info ctinfo; 434 435 ct = nf_ct_get(*pskb, &ctinfo); 436 437 /* ipt_REJECT uses nf_conntrack_attach to attach related 438 ICMP/TCP RST packets in other direction. Actual packet 439 which created connection will be IP_CT_NEW or for an 440 expected connection, IP_CT_RELATED. */ 441 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) 442 return NF_ACCEPT; 443 444 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 445 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 446 447 /* We're not in hash table, and we refuse to set up related 448 connections for unconfirmed conns. But packet copies and 449 REJECT will give spurious warnings here. */ 450 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ 451 452 /* No external references means noone else could have 453 confirmed us. */ 454 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 455 DEBUGP("Confirming conntrack %p\n", ct); 456 457 write_lock_bh(&nf_conntrack_lock); 458 459 /* See if there's one in the list already, including reverse: 460 NAT could have grabbed it without realizing, since we're 461 not in the hash. If there is, we lost race. */ 462 list_for_each_entry(h, &nf_conntrack_hash[hash], list) 463 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, 464 &h->tuple)) 465 goto out; 466 list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list) 467 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, 468 &h->tuple)) 469 goto out; 470 471 /* Remove from unconfirmed list */ 472 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 473 474 __nf_conntrack_hash_insert(ct, hash, repl_hash); 475 /* Timer relative to confirmation time, not original 476 setting time, otherwise we'd get timer wrap in 477 weird delay cases. */ 478 ct->timeout.expires += jiffies; 479 add_timer(&ct->timeout); 480 atomic_inc(&ct->ct_general.use); 481 set_bit(IPS_CONFIRMED_BIT, &ct->status); 482 NF_CT_STAT_INC(insert); 483 write_unlock_bh(&nf_conntrack_lock); 484 help = nfct_help(ct); 485 if (help && help->helper) 486 nf_conntrack_event_cache(IPCT_HELPER, *pskb); 487#ifdef CONFIG_NF_NAT_NEEDED 488 if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || 489 test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) 490 nf_conntrack_event_cache(IPCT_NATINFO, *pskb); 491#endif 492 nf_conntrack_event_cache(master_ct(ct) ? 493 IPCT_RELATED : IPCT_NEW, *pskb); 494 return NF_ACCEPT; 495 496out: 497 NF_CT_STAT_INC(insert_failed); 498 write_unlock_bh(&nf_conntrack_lock); 499 return NF_DROP; 500} 501 502/* Returns true if a connection correspondings to the tuple (required 503 for NAT). */ 504int 505nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, 506 const struct nf_conn *ignored_conntrack) 507{ 508 struct nf_conntrack_tuple_hash *h; 509 510 read_lock_bh(&nf_conntrack_lock); 511 h = __nf_conntrack_find(tuple, ignored_conntrack); 512 read_unlock_bh(&nf_conntrack_lock); 513 514 return h != NULL; 515} 516 517/* There's a small race here where we may free a just-assured 518 connection. Too bad: we're in trouble anyway. */ 519static int early_drop(struct list_head *chain) 520{ 521 /* Traverse backwards: gives us oldest, which is roughly LRU */ 522 struct nf_conntrack_tuple_hash *h; 523 struct nf_conn *ct = NULL, *tmp; 524 int dropped = 0; 525 526 read_lock_bh(&nf_conntrack_lock); 527 list_for_each_entry_reverse(h, chain, list) { 528 tmp = nf_ct_tuplehash_to_ctrack(h); 529 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { 530 ct = tmp; 531 atomic_inc(&ct->ct_general.use); 532 break; 533 } 534 } 535 read_unlock_bh(&nf_conntrack_lock); 536 537 if (!ct) 538 return dropped; 539 540 if (del_timer(&ct->timeout)) { 541 death_by_timeout((unsigned long)ct); 542 dropped = 1; 543 NF_CT_STAT_INC(early_drop); 544 } 545 nf_ct_put(ct); 546 return dropped; 547} 548 549static struct nf_conn * 550__nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 551 const struct nf_conntrack_tuple *repl, 552 const struct nf_conntrack_l3proto *l3proto, 553 u_int32_t features) 554{ 555 struct nf_conn *conntrack = NULL; 556 struct nf_conntrack_helper *helper; 557 558 if (unlikely(!nf_conntrack_hash_rnd_initted)) { 559 get_random_bytes(&nf_conntrack_hash_rnd, 4); 560 nf_conntrack_hash_rnd_initted = 1; 561 } 562 563 /* We don't want any race condition at early drop stage */ 564 atomic_inc(&nf_conntrack_count); 565 566 if (nf_conntrack_max 567 && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { 568 unsigned int hash = hash_conntrack(orig); 569 /* Try dropping from this hash chain. */ 570 if (!early_drop(&nf_conntrack_hash[hash])) { 571 atomic_dec(&nf_conntrack_count); 572 if (net_ratelimit()) 573 printk(KERN_WARNING 574 "nf_conntrack: table full, dropping" 575 " packet.\n"); 576 return ERR_PTR(-ENOMEM); 577 } 578 } 579 580 /* find features needed by this conntrack. */ 581 features |= l3proto->get_features(orig); 582 583 /* FIXME: protect helper list per RCU */ 584 read_lock_bh(&nf_conntrack_lock); 585 helper = __nf_ct_helper_find(repl); 586 /* NAT might want to assign a helper later */ 587 if (helper || features & NF_CT_F_NAT) 588 features |= NF_CT_F_HELP; 589 read_unlock_bh(&nf_conntrack_lock); 590 591 DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); 592 593 read_lock_bh(&nf_ct_cache_lock); 594 595 if (unlikely(!nf_ct_cache[features].use)) { 596 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", 597 features); 598 goto out; 599 } 600 601 conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); 602 if (conntrack == NULL) { 603 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); 604 goto out; 605 } 606 607 memset(conntrack, 0, nf_ct_cache[features].size); 608 conntrack->features = features; 609 atomic_set(&conntrack->ct_general.use, 1); 610 conntrack->ct_general.destroy = destroy_conntrack; 611 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; 612 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; 613 /* Don't set timer yet: wait for confirmation */ 614 init_timer(&conntrack->timeout); 615 conntrack->timeout.data = (unsigned long)conntrack; 616 conntrack->timeout.function = death_by_timeout; 617 read_unlock_bh(&nf_ct_cache_lock); 618 619 return conntrack; 620out: 621 read_unlock_bh(&nf_ct_cache_lock); 622 atomic_dec(&nf_conntrack_count); 623 return conntrack; 624} 625 626struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 627 const struct nf_conntrack_tuple *repl) 628{ 629 struct nf_conntrack_l3proto *l3proto; 630 631 l3proto = __nf_ct_l3proto_find(orig->src.l3num); 632 return __nf_conntrack_alloc(orig, repl, l3proto, 0); 633} 634 635void nf_conntrack_free(struct nf_conn *conntrack) 636{ 637 u_int32_t features = conntrack->features; 638 NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); 639 DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, 640 conntrack); 641 kmem_cache_free(nf_ct_cache[features].cachep, conntrack); 642 atomic_dec(&nf_conntrack_count); 643} 644 645/* Allocate a new conntrack: we return -ENOMEM if classification 646 failed due to stress. Otherwise it really is unclassifiable. */ 647static struct nf_conntrack_tuple_hash * 648init_conntrack(const struct nf_conntrack_tuple *tuple, 649 struct nf_conntrack_l3proto *l3proto, 650 struct nf_conntrack_l4proto *l4proto, 651 struct sk_buff *skb, 652 unsigned int dataoff) 653{ 654 struct nf_conn *conntrack; 655 struct nf_conntrack_tuple repl_tuple; 656 struct nf_conntrack_expect *exp; 657 u_int32_t features = 0; 658 659 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { 660 DEBUGP("Can't invert tuple.\n"); 661 return NULL; 662 } 663 664 read_lock_bh(&nf_conntrack_lock); 665 exp = __nf_conntrack_expect_find(tuple); 666 if (exp && exp->helper) 667 features = NF_CT_F_HELP; 668 read_unlock_bh(&nf_conntrack_lock); 669 670 conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features); 671 if (conntrack == NULL || IS_ERR(conntrack)) { 672 DEBUGP("Can't allocate conntrack.\n"); 673 return (struct nf_conntrack_tuple_hash *)conntrack; 674 } 675 676 if (!l4proto->new(conntrack, skb, dataoff)) { 677 nf_conntrack_free(conntrack); 678 DEBUGP("init conntrack: can't track with proto module\n"); 679 return NULL; 680 } 681 682 write_lock_bh(&nf_conntrack_lock); 683 exp = find_expectation(tuple); 684 685 if (exp) { 686 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", 687 conntrack, exp); 688 /* Welcome, Mr. Bond. We've been expecting you... */ 689 __set_bit(IPS_EXPECTED_BIT, &conntrack->status); 690 conntrack->master = exp->master; 691 if (exp->helper) 692 nfct_help(conntrack)->helper = exp->helper; 693#ifdef CONFIG_NF_CONNTRACK_MARK 694 conntrack->mark = exp->master->mark; 695#endif 696#ifdef CONFIG_NF_CONNTRACK_SECMARK 697 conntrack->secmark = exp->master->secmark; 698#endif 699 nf_conntrack_get(&conntrack->master->ct_general); 700 NF_CT_STAT_INC(expect_new); 701 } else { 702 struct nf_conn_help *help = nfct_help(conntrack); 703 704 if (help) 705 help->helper = __nf_ct_helper_find(&repl_tuple); 706 NF_CT_STAT_INC(new); 707 } 708 709 /* Overload tuple linked list to put us in unconfirmed list. */ 710 list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); 711 712 write_unlock_bh(&nf_conntrack_lock); 713 714 if (exp) { 715 if (exp->expectfn) 716 exp->expectfn(conntrack, exp); 717 nf_conntrack_expect_put(exp); 718 } 719 720 return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; 721} 722 723/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ 724static inline struct nf_conn * 725resolve_normal_ct(struct sk_buff *skb, 726 unsigned int dataoff, 727 u_int16_t l3num, 728 u_int8_t protonum, 729 struct nf_conntrack_l3proto *l3proto, 730 struct nf_conntrack_l4proto *l4proto, 731 int *set_reply, 732 enum ip_conntrack_info *ctinfo) 733{ 734 struct nf_conntrack_tuple tuple; 735 struct nf_conntrack_tuple_hash *h; 736 struct nf_conn *ct; 737 738 if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), 739 dataoff, l3num, protonum, &tuple, l3proto, 740 l4proto)) { 741 DEBUGP("resolve_normal_ct: Can't get tuple\n"); 742 return NULL; 743 } 744 745 /* look for tuple match */ 746 h = nf_conntrack_find_get(&tuple, NULL); 747 if (!h) { 748 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff); 749 if (!h) 750 return NULL; 751 if (IS_ERR(h)) 752 return (void *)h; 753 } 754 ct = nf_ct_tuplehash_to_ctrack(h); 755 756 /* It exists; we have (non-exclusive) reference. */ 757 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { 758 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; 759 /* Please set reply bit if this packet OK */ 760 *set_reply = 1; 761 } else { 762 /* Once we've had two way comms, always ESTABLISHED. */ 763 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { 764 DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); 765 *ctinfo = IP_CT_ESTABLISHED; 766 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { 767 DEBUGP("nf_conntrack_in: related packet for %p\n", ct); 768 *ctinfo = IP_CT_RELATED; 769 } else { 770 DEBUGP("nf_conntrack_in: new packet for %p\n", ct); 771 *ctinfo = IP_CT_NEW; 772 } 773 *set_reply = 0; 774 } 775 skb->nfct = &ct->ct_general; 776 skb->nfctinfo = *ctinfo; 777 return ct; 778} 779 780unsigned int 781nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) 782{ 783 struct nf_conn *ct; 784 enum ip_conntrack_info ctinfo; 785 struct nf_conntrack_l3proto *l3proto; 786 struct nf_conntrack_l4proto *l4proto; 787 unsigned int dataoff; 788 u_int8_t protonum; 789 int set_reply = 0; 790 int ret; 791 792 /* Previously seen (loopback or untracked)? Ignore. */ 793 if ((*pskb)->nfct) { 794 NF_CT_STAT_INC(ignore); 795 return NF_ACCEPT; 796 } 797 798 l3proto = __nf_ct_l3proto_find((u_int16_t)pf); 799 if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { 800 DEBUGP("not prepared to track yet or error occured\n"); 801 return -ret; 802 } 803 804 l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum); 805 806 /* It may be an special packet, error, unclean... 807 * inverse of the return code tells to the netfilter 808 * core what to do with the packet. */ 809 if (l4proto->error != NULL && 810 (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { 811 NF_CT_STAT_INC(error); 812 NF_CT_STAT_INC(invalid); 813 return -ret; 814 } 815 816 ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto, 817 &set_reply, &ctinfo); 818 if (!ct) { 819 /* Not valid part of a connection */ 820 NF_CT_STAT_INC(invalid); 821 return NF_ACCEPT; 822 } 823 824 if (IS_ERR(ct)) { 825 /* Too stressed to deal. */ 826 NF_CT_STAT_INC(drop); 827 return NF_DROP; 828 } 829 830 NF_CT_ASSERT((*pskb)->nfct); 831 832 ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); 833 if (ret < 0) { 834 /* Invalid: inverse of the return code tells 835 * the netfilter core what to do */ 836 DEBUGP("nf_conntrack_in: Can't track with proto module\n"); 837 nf_conntrack_put((*pskb)->nfct); 838 (*pskb)->nfct = NULL; 839 NF_CT_STAT_INC(invalid); 840 return -ret; 841 } 842 843 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) 844 nf_conntrack_event_cache(IPCT_STATUS, *pskb); 845 846 return ret; 847} 848 849int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, 850 const struct nf_conntrack_tuple *orig) 851{ 852 return nf_ct_invert_tuple(inverse, orig, 853 __nf_ct_l3proto_find(orig->src.l3num), 854 __nf_ct_l4proto_find(orig->src.l3num, 855 orig->dst.protonum)); 856} 857 858/* Alter reply tuple (maybe alter helper). This is for NAT, and is 859 implicitly racy: see __nf_conntrack_confirm */ 860void nf_conntrack_alter_reply(struct nf_conn *ct, 861 const struct nf_conntrack_tuple *newreply) 862{ 863 struct nf_conn_help *help = nfct_help(ct); 864 865 write_lock_bh(&nf_conntrack_lock); 866 /* Should be unconfirmed, so not in hash table yet */ 867 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 868 869 DEBUGP("Altering reply tuple of %p to ", ct); 870 NF_CT_DUMP_TUPLE(newreply); 871 872 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; 873 if (!ct->master && help && help->expecting == 0) 874 help->helper = __nf_ct_helper_find(newreply); 875 write_unlock_bh(&nf_conntrack_lock); 876} 877 878/* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ 879void __nf_ct_refresh_acct(struct nf_conn *ct, 880 enum ip_conntrack_info ctinfo, 881 const struct sk_buff *skb, 882 unsigned long extra_jiffies, 883 int do_acct) 884{ 885 int event = 0; 886 887 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); 888 NF_CT_ASSERT(skb); 889 890 write_lock_bh(&nf_conntrack_lock); 891 892 /* Only update if this is not a fixed timeout */ 893 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { 894 write_unlock_bh(&nf_conntrack_lock); 895 return; 896 } 897 898 /* If not in hash table, timer will not be active yet */ 899 if (!nf_ct_is_confirmed(ct)) { 900 ct->timeout.expires = extra_jiffies; 901 event = IPCT_REFRESH; 902 } else { 903 unsigned long newtime = jiffies + extra_jiffies; 904 905 /* Only update the timeout if the new timeout is at least 906 HZ jiffies from the old timeout. Need del_timer for race 907 avoidance (may already be dying). */ 908 if (newtime - ct->timeout.expires >= HZ 909 && del_timer(&ct->timeout)) { 910 ct->timeout.expires = newtime; 911 add_timer(&ct->timeout); 912 event = IPCT_REFRESH; 913 } 914 } 915 916#ifdef CONFIG_NF_CT_ACCT 917 if (do_acct) { 918 ct->counters[CTINFO2DIR(ctinfo)].packets++; 919 ct->counters[CTINFO2DIR(ctinfo)].bytes += 920 skb->len - (unsigned int)(skb->nh.raw - skb->data); 921 922 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) 923 || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) 924 event |= IPCT_COUNTER_FILLING; 925 } 926#endif 927 928 write_unlock_bh(&nf_conntrack_lock); 929 930 /* must be unlocked when calling event cache */ 931 if (event) 932 nf_conntrack_event_cache(event, skb); 933} 934 935#if defined(CONFIG_NF_CT_NETLINK) || \ 936 defined(CONFIG_NF_CT_NETLINK_MODULE) 937 938#include <linux/netfilter/nfnetlink.h> 939#include <linux/netfilter/nfnetlink_conntrack.h> 940#include <linux/mutex.h> 941 942 943/* Generic function for tcp/udp/sctp/dccp and alike. This needs to be 944 * in ip_conntrack_core, since we don't want the protocols to autoload 945 * or depend on ctnetlink */ 946int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, 947 const struct nf_conntrack_tuple *tuple) 948{ 949 NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), 950 &tuple->src.u.tcp.port); 951 NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), 952 &tuple->dst.u.tcp.port); 953 return 0; 954 955nfattr_failure: 956 return -1; 957} 958 959static const size_t cta_min_proto[CTA_PROTO_MAX] = { 960 [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), 961 [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) 962}; 963 964int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], 965 struct nf_conntrack_tuple *t) 966{ 967 if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) 968 return -EINVAL; 969 970 if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) 971 return -EINVAL; 972 973 t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); 974 t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); 975 976 return 0; 977} 978#endif 979 980/* Used by ipt_REJECT and ip6t_REJECT. */ 981void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) 982{ 983 struct nf_conn *ct; 984 enum ip_conntrack_info ctinfo; 985 986 /* This ICMP is in reverse direction to the packet which caused it */ 987 ct = nf_ct_get(skb, &ctinfo); 988 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) 989 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; 990 else 991 ctinfo = IP_CT_RELATED; 992 993 /* Attach to new skbuff, and increment count */ 994 nskb->nfct = &ct->ct_general; 995 nskb->nfctinfo = ctinfo; 996 nf_conntrack_get(nskb->nfct); 997} 998 999static inline int 1000do_iter(const struct nf_conntrack_tuple_hash *i, 1001 int (*iter)(struct nf_conn *i, void *data), 1002 void *data) 1003{ 1004 return iter(nf_ct_tuplehash_to_ctrack(i), data); 1005} 1006 1007/* Bring out ya dead! */ 1008static struct nf_conn * 1009get_next_corpse(int (*iter)(struct nf_conn *i, void *data), 1010 void *data, unsigned int *bucket) 1011{ 1012 struct nf_conntrack_tuple_hash *h; 1013 struct nf_conn *ct; 1014 1015 write_lock_bh(&nf_conntrack_lock); 1016 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { 1017 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) { 1018 ct = nf_ct_tuplehash_to_ctrack(h); 1019 if (iter(ct, data)) 1020 goto found; 1021 } 1022 } 1023 list_for_each_entry(h, &unconfirmed, list) { 1024 ct = nf_ct_tuplehash_to_ctrack(h); 1025 if (iter(ct, data)) 1026 goto found; 1027 } 1028 write_unlock_bh(&nf_conntrack_lock); 1029 return NULL; 1030found: 1031 atomic_inc(&ct->ct_general.use); 1032 write_unlock_bh(&nf_conntrack_lock); 1033 return ct; 1034} 1035 1036void 1037nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) 1038{ 1039 struct nf_conn *ct; 1040 unsigned int bucket = 0; 1041 1042 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { 1043 /* Time to push up daises... */ 1044 if (del_timer(&ct->timeout)) 1045 death_by_timeout((unsigned long)ct); 1046 /* ... else the timer will get him soon. */ 1047 1048 nf_ct_put(ct); 1049 } 1050} 1051 1052static int kill_all(struct nf_conn *i, void *data) 1053{ 1054 return 1; 1055} 1056 1057static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) 1058{ 1059 if (vmalloced) 1060 vfree(hash); 1061 else 1062 free_pages((unsigned long)hash, 1063 get_order(sizeof(struct list_head) * size)); 1064} 1065 1066void nf_conntrack_flush() 1067{ 1068 nf_ct_iterate_cleanup(kill_all, NULL); 1069} 1070 1071/* Mishearing the voices in his head, our hero wonders how he's 1072 supposed to kill the mall. */ 1073void nf_conntrack_cleanup(void) 1074{ 1075 int i; 1076 1077 ip_ct_attach = NULL; 1078 1079 /* This makes sure all current packets have passed through 1080 netfilter framework. Roll on, two-stage module 1081 delete... */ 1082 synchronize_net(); 1083 1084 nf_ct_event_cache_flush(); 1085 i_see_dead_people: 1086 nf_conntrack_flush(); 1087 if (atomic_read(&nf_conntrack_count) != 0) { 1088 schedule(); 1089 goto i_see_dead_people; 1090 } 1091 /* wait until all references to nf_conntrack_untracked are dropped */ 1092 while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) 1093 schedule(); 1094 1095 for (i = 0; i < NF_CT_F_NUM; i++) { 1096 if (nf_ct_cache[i].use == 0) 1097 continue; 1098 1099 NF_CT_ASSERT(nf_ct_cache[i].use == 1); 1100 nf_ct_cache[i].use = 1; 1101 nf_conntrack_unregister_cache(i); 1102 } 1103 kmem_cache_destroy(nf_conntrack_expect_cachep); 1104 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1105 nf_conntrack_htable_size); 1106 1107 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic); 1108 1109 /* free l3proto protocol tables */ 1110 for (i = 0; i < PF_MAX; i++) 1111 if (nf_ct_protos[i]) { 1112 kfree(nf_ct_protos[i]); 1113 nf_ct_protos[i] = NULL; 1114 } 1115} 1116 1117static struct list_head *alloc_hashtable(int size, int *vmalloced) 1118{ 1119 struct list_head *hash; 1120 unsigned int i; 1121 1122 *vmalloced = 0; 1123 hash = (void*)__get_free_pages(GFP_KERNEL, 1124 get_order(sizeof(struct list_head) 1125 * size)); 1126 if (!hash) { 1127 *vmalloced = 1; 1128 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); 1129 hash = vmalloc(sizeof(struct list_head) * size); 1130 } 1131 1132 if (hash) 1133 for (i = 0; i < size; i++) 1134 INIT_LIST_HEAD(&hash[i]); 1135 1136 return hash; 1137} 1138 1139int set_hashsize(const char *val, struct kernel_param *kp) 1140{ 1141 int i, bucket, hashsize, vmalloced; 1142 int old_vmalloced, old_size; 1143 int rnd; 1144 struct list_head *hash, *old_hash; 1145 struct nf_conntrack_tuple_hash *h; 1146 1147 /* On boot, we can set this without any fancy locking. */ 1148 if (!nf_conntrack_htable_size) 1149 return param_set_uint(val, kp); 1150 1151 hashsize = simple_strtol(val, NULL, 0); 1152 if (!hashsize) 1153 return -EINVAL; 1154 1155 hash = alloc_hashtable(hashsize, &vmalloced); 1156 if (!hash) 1157 return -ENOMEM; 1158 1159 /* We have to rehahs for the new table anyway, so we also can 1160 * use a newrandom seed */ 1161 get_random_bytes(&rnd, 4); 1162 1163 write_lock_bh(&nf_conntrack_lock); 1164 for (i = 0; i < nf_conntrack_htable_size; i++) { 1165 while (!list_empty(&nf_conntrack_hash[i])) { 1166 h = list_entry(nf_conntrack_hash[i].next, 1167 struct nf_conntrack_tuple_hash, list); 1168 list_del(&h->list); 1169 bucket = __hash_conntrack(&h->tuple, hashsize, rnd); 1170 list_add_tail(&h->list, &hash[bucket]); 1171 } 1172 } 1173 old_size = nf_conntrack_htable_size; 1174 old_vmalloced = nf_conntrack_vmalloc; 1175 old_hash = nf_conntrack_hash; 1176 1177 nf_conntrack_htable_size = hashsize; 1178 nf_conntrack_vmalloc = vmalloced; 1179 nf_conntrack_hash = hash; 1180 nf_conntrack_hash_rnd = rnd; 1181 write_unlock_bh(&nf_conntrack_lock); 1182 1183 free_conntrack_hash(old_hash, old_vmalloced, old_size); 1184 return 0; 1185} 1186 1187module_param_call(hashsize, set_hashsize, param_get_uint, 1188 &nf_conntrack_htable_size, 0600); 1189 1190int __init nf_conntrack_init(void) 1191{ 1192 unsigned int i; 1193 int ret; 1194 1195 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB 1196 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ 1197 if (!nf_conntrack_htable_size) { 1198 nf_conntrack_htable_size 1199 = (((num_physpages << PAGE_SHIFT) / 16384) 1200 / sizeof(struct list_head)); 1201 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) 1202 nf_conntrack_htable_size = 8192; 1203 if (nf_conntrack_htable_size < 16) 1204 nf_conntrack_htable_size = 16; 1205 } 1206 nf_conntrack_max = 8 * nf_conntrack_htable_size; 1207 1208 printk("nf_conntrack version %s (%u buckets, %d max)\n", 1209 NF_CONNTRACK_VERSION, nf_conntrack_htable_size, 1210 nf_conntrack_max); 1211 1212 nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, 1213 &nf_conntrack_vmalloc); 1214 if (!nf_conntrack_hash) { 1215 printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); 1216 goto err_out; 1217 } 1218 1219 ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", 1220 sizeof(struct nf_conn)); 1221 if (ret < 0) { 1222 printk(KERN_ERR "Unable to create nf_conn slab cache\n"); 1223 goto err_free_hash; 1224 } 1225 1226 nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", 1227 sizeof(struct nf_conntrack_expect), 1228 0, 0, NULL, NULL); 1229 if (!nf_conntrack_expect_cachep) { 1230 printk(KERN_ERR "Unable to create nf_expect slab cache\n"); 1231 goto err_free_conntrack_slab; 1232 } 1233 1234 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic); 1235 if (ret < 0) 1236 goto out_free_expect_slab; 1237 1238 /* Don't NEED lock here, but good form anyway. */ 1239 write_lock_bh(&nf_conntrack_lock); 1240 for (i = 0; i < AF_MAX; i++) 1241 nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic; 1242 write_unlock_bh(&nf_conntrack_lock); 1243 1244 /* For use by REJECT target */ 1245 ip_ct_attach = __nf_conntrack_attach; 1246 1247 /* Set up fake conntrack: 1248 - to never be deleted, not in any hashes */ 1249 atomic_set(&nf_conntrack_untracked.ct_general.use, 1); 1250 /* - and look it like as a confirmed connection */ 1251 set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); 1252 1253 return ret; 1254 1255out_free_expect_slab: 1256 kmem_cache_destroy(nf_conntrack_expect_cachep); 1257err_free_conntrack_slab: 1258 nf_conntrack_unregister_cache(NF_CT_F_BASIC); 1259err_free_hash: 1260 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1261 nf_conntrack_htable_size); 1262err_out: 1263 return -ENOMEM; 1264} 1265