nf_conntrack_core.c revision ceceae1b1555a9afcb8dacf90df5fa1f20fd5466
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 14#include <linux/types.h> 15#include <linux/netfilter.h> 16#include <linux/module.h> 17#include <linux/skbuff.h> 18#include <linux/proc_fs.h> 19#include <linux/vmalloc.h> 20#include <linux/stddef.h> 21#include <linux/slab.h> 22#include <linux/random.h> 23#include <linux/jhash.h> 24#include <linux/err.h> 25#include <linux/percpu.h> 26#include <linux/moduleparam.h> 27#include <linux/notifier.h> 28#include <linux/kernel.h> 29#include <linux/netdevice.h> 30#include <linux/socket.h> 31#include <linux/mm.h> 32 33#include <net/netfilter/nf_conntrack.h> 34#include <net/netfilter/nf_conntrack_l3proto.h> 35#include <net/netfilter/nf_conntrack_l4proto.h> 36#include <net/netfilter/nf_conntrack_expect.h> 37#include <net/netfilter/nf_conntrack_helper.h> 38#include <net/netfilter/nf_conntrack_core.h> 39#include <net/netfilter/nf_conntrack_extend.h> 40 41#define NF_CONNTRACK_VERSION "0.5.0" 42 43#if 0 44#define DEBUGP printk 45#else 46#define DEBUGP(format, args...) 47#endif 48 49DEFINE_RWLOCK(nf_conntrack_lock); 50EXPORT_SYMBOL_GPL(nf_conntrack_lock); 51 52/* nf_conntrack_standalone needs this */ 53atomic_t nf_conntrack_count = ATOMIC_INIT(0); 54EXPORT_SYMBOL_GPL(nf_conntrack_count); 55 56void (*nf_conntrack_destroyed)(struct nf_conn *conntrack); 57EXPORT_SYMBOL_GPL(nf_conntrack_destroyed); 58 59unsigned int nf_conntrack_htable_size __read_mostly; 60EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); 61 62int nf_conntrack_max __read_mostly; 63EXPORT_SYMBOL_GPL(nf_conntrack_max); 64 65struct list_head *nf_conntrack_hash __read_mostly; 66EXPORT_SYMBOL_GPL(nf_conntrack_hash); 67 68struct nf_conn nf_conntrack_untracked __read_mostly; 69EXPORT_SYMBOL_GPL(nf_conntrack_untracked); 70 71unsigned int nf_ct_log_invalid __read_mostly; 72LIST_HEAD(unconfirmed); 73static int nf_conntrack_vmalloc __read_mostly; 74 75static unsigned int nf_conntrack_next_id; 76 77DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); 78EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); 79 80/* 81 * This scheme offers various size of "struct nf_conn" dependent on 82 * features(helper, nat, ...) 83 */ 84 85#define NF_CT_FEATURES_NAMELEN 256 86static struct { 87 /* name of slab cache. printed in /proc/slabinfo */ 88 char *name; 89 90 /* size of slab cache */ 91 size_t size; 92 93 /* slab cache pointer */ 94 struct kmem_cache *cachep; 95 96 /* allocated slab cache + modules which uses this slab cache */ 97 int use; 98 99} nf_ct_cache[NF_CT_F_NUM]; 100 101/* protect members of nf_ct_cache except of "use" */ 102DEFINE_RWLOCK(nf_ct_cache_lock); 103 104/* This avoids calling kmem_cache_create() with same name simultaneously */ 105static DEFINE_MUTEX(nf_ct_cache_mutex); 106 107static int nf_conntrack_hash_rnd_initted; 108static unsigned int nf_conntrack_hash_rnd; 109 110static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, 111 unsigned int size, unsigned int rnd) 112{ 113 unsigned int a, b; 114 115 a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all), 116 (tuple->src.l3num << 16) | tuple->dst.protonum); 117 b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all), 118 (tuple->src.u.all << 16) | tuple->dst.u.all); 119 120 return jhash_2words(a, b, rnd) % size; 121} 122 123static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) 124{ 125 return __hash_conntrack(tuple, nf_conntrack_htable_size, 126 nf_conntrack_hash_rnd); 127} 128 129int nf_conntrack_register_cache(u_int32_t features, const char *name, 130 size_t size) 131{ 132 int ret = 0; 133 char *cache_name; 134 struct kmem_cache *cachep; 135 136 DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", 137 features, name, size); 138 139 if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { 140 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", 141 features); 142 return -EINVAL; 143 } 144 145 mutex_lock(&nf_ct_cache_mutex); 146 147 write_lock_bh(&nf_ct_cache_lock); 148 /* e.g: multiple helpers are loaded */ 149 if (nf_ct_cache[features].use > 0) { 150 DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); 151 if ((!strncmp(nf_ct_cache[features].name, name, 152 NF_CT_FEATURES_NAMELEN)) 153 && nf_ct_cache[features].size == size) { 154 DEBUGP("nf_conntrack_register_cache: reusing.\n"); 155 nf_ct_cache[features].use++; 156 ret = 0; 157 } else 158 ret = -EBUSY; 159 160 write_unlock_bh(&nf_ct_cache_lock); 161 mutex_unlock(&nf_ct_cache_mutex); 162 return ret; 163 } 164 write_unlock_bh(&nf_ct_cache_lock); 165 166 /* 167 * The memory space for name of slab cache must be alive until 168 * cache is destroyed. 169 */ 170 cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); 171 if (cache_name == NULL) { 172 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); 173 ret = -ENOMEM; 174 goto out_up_mutex; 175 } 176 177 if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) 178 >= NF_CT_FEATURES_NAMELEN) { 179 printk("nf_conntrack_register_cache: name too long\n"); 180 ret = -EINVAL; 181 goto out_free_name; 182 } 183 184 cachep = kmem_cache_create(cache_name, size, 0, 0, 185 NULL, NULL); 186 if (!cachep) { 187 printk("nf_conntrack_register_cache: Can't create slab cache " 188 "for the features = 0x%x\n", features); 189 ret = -ENOMEM; 190 goto out_free_name; 191 } 192 193 write_lock_bh(&nf_ct_cache_lock); 194 nf_ct_cache[features].use = 1; 195 nf_ct_cache[features].size = size; 196 nf_ct_cache[features].cachep = cachep; 197 nf_ct_cache[features].name = cache_name; 198 write_unlock_bh(&nf_ct_cache_lock); 199 200 goto out_up_mutex; 201 202out_free_name: 203 kfree(cache_name); 204out_up_mutex: 205 mutex_unlock(&nf_ct_cache_mutex); 206 return ret; 207} 208EXPORT_SYMBOL_GPL(nf_conntrack_register_cache); 209 210/* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ 211void nf_conntrack_unregister_cache(u_int32_t features) 212{ 213 struct kmem_cache *cachep; 214 char *name; 215 216 /* 217 * This assures that kmem_cache_create() isn't called before destroying 218 * slab cache. 219 */ 220 DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); 221 mutex_lock(&nf_ct_cache_mutex); 222 223 write_lock_bh(&nf_ct_cache_lock); 224 if (--nf_ct_cache[features].use > 0) { 225 write_unlock_bh(&nf_ct_cache_lock); 226 mutex_unlock(&nf_ct_cache_mutex); 227 return; 228 } 229 cachep = nf_ct_cache[features].cachep; 230 name = nf_ct_cache[features].name; 231 nf_ct_cache[features].cachep = NULL; 232 nf_ct_cache[features].name = NULL; 233 nf_ct_cache[features].size = 0; 234 write_unlock_bh(&nf_ct_cache_lock); 235 236 synchronize_net(); 237 238 kmem_cache_destroy(cachep); 239 kfree(name); 240 241 mutex_unlock(&nf_ct_cache_mutex); 242} 243EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache); 244 245int 246nf_ct_get_tuple(const struct sk_buff *skb, 247 unsigned int nhoff, 248 unsigned int dataoff, 249 u_int16_t l3num, 250 u_int8_t protonum, 251 struct nf_conntrack_tuple *tuple, 252 const struct nf_conntrack_l3proto *l3proto, 253 const struct nf_conntrack_l4proto *l4proto) 254{ 255 NF_CT_TUPLE_U_BLANK(tuple); 256 257 tuple->src.l3num = l3num; 258 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) 259 return 0; 260 261 tuple->dst.protonum = protonum; 262 tuple->dst.dir = IP_CT_DIR_ORIGINAL; 263 264 return l4proto->pkt_to_tuple(skb, dataoff, tuple); 265} 266EXPORT_SYMBOL_GPL(nf_ct_get_tuple); 267 268int 269nf_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} 285EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); 286 287static void 288clean_from_lists(struct nf_conn *ct) 289{ 290 DEBUGP("clean_from_lists(%p)\n", ct); 291 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 292 list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); 293 294 /* Destroy all pending expectations */ 295 nf_ct_remove_expectations(ct); 296} 297 298static void 299destroy_conntrack(struct nf_conntrack *nfct) 300{ 301 struct nf_conn *ct = (struct nf_conn *)nfct; 302 struct nf_conntrack_l4proto *l4proto; 303 typeof(nf_conntrack_destroyed) destroyed; 304 305 DEBUGP("destroy_conntrack(%p)\n", ct); 306 NF_CT_ASSERT(atomic_read(&nfct->use) == 0); 307 NF_CT_ASSERT(!timer_pending(&ct->timeout)); 308 309 nf_conntrack_event(IPCT_DESTROY, ct); 310 set_bit(IPS_DYING_BIT, &ct->status); 311 312 /* To make sure we don't get any weird locking issues here: 313 * destroy_conntrack() MUST NOT be called with a write lock 314 * to nf_conntrack_lock!!! -HW */ 315 rcu_read_lock(); 316 l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, 317 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); 318 if (l4proto && l4proto->destroy) 319 l4proto->destroy(ct); 320 321 nf_ct_ext_destroy(ct); 322 323 destroyed = rcu_dereference(nf_conntrack_destroyed); 324 if (destroyed) 325 destroyed(ct); 326 327 rcu_read_unlock(); 328 329 write_lock_bh(&nf_conntrack_lock); 330 /* Expectations will have been removed in clean_from_lists, 331 * except TFTP can create an expectation on the first packet, 332 * before connection is in the list, so we need to clean here, 333 * too. */ 334 nf_ct_remove_expectations(ct); 335 336 /* We overload first tuple to link into unconfirmed list. */ 337 if (!nf_ct_is_confirmed(ct)) { 338 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); 339 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 340 } 341 342 NF_CT_STAT_INC(delete); 343 write_unlock_bh(&nf_conntrack_lock); 344 345 if (ct->master) 346 nf_ct_put(ct->master); 347 348 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); 349 nf_conntrack_free(ct); 350} 351 352static void death_by_timeout(unsigned long ul_conntrack) 353{ 354 struct nf_conn *ct = (void *)ul_conntrack; 355 struct nf_conn_help *help = nfct_help(ct); 356 struct nf_conntrack_helper *helper; 357 358 if (help) { 359 rcu_read_lock(); 360 helper = rcu_dereference(help->helper); 361 if (helper && helper->destroy) 362 helper->destroy(ct); 363 rcu_read_unlock(); 364 } 365 366 write_lock_bh(&nf_conntrack_lock); 367 /* Inside lock so preempt is disabled on module removal path. 368 * Otherwise we can get spurious warnings. */ 369 NF_CT_STAT_INC(delete_list); 370 clean_from_lists(ct); 371 write_unlock_bh(&nf_conntrack_lock); 372 nf_ct_put(ct); 373} 374 375struct nf_conntrack_tuple_hash * 376__nf_conntrack_find(const struct nf_conntrack_tuple *tuple, 377 const struct nf_conn *ignored_conntrack) 378{ 379 struct nf_conntrack_tuple_hash *h; 380 unsigned int hash = hash_conntrack(tuple); 381 382 list_for_each_entry(h, &nf_conntrack_hash[hash], list) { 383 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && 384 nf_ct_tuple_equal(tuple, &h->tuple)) { 385 NF_CT_STAT_INC(found); 386 return h; 387 } 388 NF_CT_STAT_INC(searched); 389 } 390 391 return NULL; 392} 393EXPORT_SYMBOL_GPL(__nf_conntrack_find); 394 395/* Find a connection corresponding to a tuple. */ 396struct nf_conntrack_tuple_hash * 397nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, 398 const struct nf_conn *ignored_conntrack) 399{ 400 struct nf_conntrack_tuple_hash *h; 401 402 read_lock_bh(&nf_conntrack_lock); 403 h = __nf_conntrack_find(tuple, ignored_conntrack); 404 if (h) 405 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); 406 read_unlock_bh(&nf_conntrack_lock); 407 408 return h; 409} 410EXPORT_SYMBOL_GPL(nf_conntrack_find_get); 411 412static void __nf_conntrack_hash_insert(struct nf_conn *ct, 413 unsigned int hash, 414 unsigned int repl_hash) 415{ 416 ct->id = ++nf_conntrack_next_id; 417 list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, 418 &nf_conntrack_hash[hash]); 419 list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, 420 &nf_conntrack_hash[repl_hash]); 421} 422 423void nf_conntrack_hash_insert(struct nf_conn *ct) 424{ 425 unsigned int hash, repl_hash; 426 427 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 428 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 429 430 write_lock_bh(&nf_conntrack_lock); 431 __nf_conntrack_hash_insert(ct, hash, repl_hash); 432 write_unlock_bh(&nf_conntrack_lock); 433} 434EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); 435 436/* Confirm a connection given skb; places it in hash table */ 437int 438__nf_conntrack_confirm(struct sk_buff **pskb) 439{ 440 unsigned int hash, repl_hash; 441 struct nf_conntrack_tuple_hash *h; 442 struct nf_conn *ct; 443 struct nf_conn_help *help; 444 enum ip_conntrack_info ctinfo; 445 446 ct = nf_ct_get(*pskb, &ctinfo); 447 448 /* ipt_REJECT uses nf_conntrack_attach to attach related 449 ICMP/TCP RST packets in other direction. Actual packet 450 which created connection will be IP_CT_NEW or for an 451 expected connection, IP_CT_RELATED. */ 452 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) 453 return NF_ACCEPT; 454 455 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); 456 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); 457 458 /* We're not in hash table, and we refuse to set up related 459 connections for unconfirmed conns. But packet copies and 460 REJECT will give spurious warnings here. */ 461 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ 462 463 /* No external references means noone else could have 464 confirmed us. */ 465 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 466 DEBUGP("Confirming conntrack %p\n", ct); 467 468 write_lock_bh(&nf_conntrack_lock); 469 470 /* See if there's one in the list already, including reverse: 471 NAT could have grabbed it without realizing, since we're 472 not in the hash. If there is, we lost race. */ 473 list_for_each_entry(h, &nf_conntrack_hash[hash], list) 474 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, 475 &h->tuple)) 476 goto out; 477 list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list) 478 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, 479 &h->tuple)) 480 goto out; 481 482 /* Remove from unconfirmed list */ 483 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); 484 485 __nf_conntrack_hash_insert(ct, hash, repl_hash); 486 /* Timer relative to confirmation time, not original 487 setting time, otherwise we'd get timer wrap in 488 weird delay cases. */ 489 ct->timeout.expires += jiffies; 490 add_timer(&ct->timeout); 491 atomic_inc(&ct->ct_general.use); 492 set_bit(IPS_CONFIRMED_BIT, &ct->status); 493 NF_CT_STAT_INC(insert); 494 write_unlock_bh(&nf_conntrack_lock); 495 help = nfct_help(ct); 496 if (help && help->helper) 497 nf_conntrack_event_cache(IPCT_HELPER, *pskb); 498#ifdef CONFIG_NF_NAT_NEEDED 499 if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || 500 test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) 501 nf_conntrack_event_cache(IPCT_NATINFO, *pskb); 502#endif 503 nf_conntrack_event_cache(master_ct(ct) ? 504 IPCT_RELATED : IPCT_NEW, *pskb); 505 return NF_ACCEPT; 506 507out: 508 NF_CT_STAT_INC(insert_failed); 509 write_unlock_bh(&nf_conntrack_lock); 510 return NF_DROP; 511} 512EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); 513 514/* Returns true if a connection correspondings to the tuple (required 515 for NAT). */ 516int 517nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, 518 const struct nf_conn *ignored_conntrack) 519{ 520 struct nf_conntrack_tuple_hash *h; 521 522 read_lock_bh(&nf_conntrack_lock); 523 h = __nf_conntrack_find(tuple, ignored_conntrack); 524 read_unlock_bh(&nf_conntrack_lock); 525 526 return h != NULL; 527} 528EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); 529 530/* There's a small race here where we may free a just-assured 531 connection. Too bad: we're in trouble anyway. */ 532static int early_drop(struct list_head *chain) 533{ 534 /* Traverse backwards: gives us oldest, which is roughly LRU */ 535 struct nf_conntrack_tuple_hash *h; 536 struct nf_conn *ct = NULL, *tmp; 537 int dropped = 0; 538 539 read_lock_bh(&nf_conntrack_lock); 540 list_for_each_entry_reverse(h, chain, list) { 541 tmp = nf_ct_tuplehash_to_ctrack(h); 542 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { 543 ct = tmp; 544 atomic_inc(&ct->ct_general.use); 545 break; 546 } 547 } 548 read_unlock_bh(&nf_conntrack_lock); 549 550 if (!ct) 551 return dropped; 552 553 if (del_timer(&ct->timeout)) { 554 death_by_timeout((unsigned long)ct); 555 dropped = 1; 556 NF_CT_STAT_INC_ATOMIC(early_drop); 557 } 558 nf_ct_put(ct); 559 return dropped; 560} 561 562static struct nf_conn * 563__nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 564 const struct nf_conntrack_tuple *repl, 565 const struct nf_conntrack_l3proto *l3proto, 566 u_int32_t features) 567{ 568 struct nf_conn *conntrack = NULL; 569 570 if (unlikely(!nf_conntrack_hash_rnd_initted)) { 571 get_random_bytes(&nf_conntrack_hash_rnd, 4); 572 nf_conntrack_hash_rnd_initted = 1; 573 } 574 575 /* We don't want any race condition at early drop stage */ 576 atomic_inc(&nf_conntrack_count); 577 578 if (nf_conntrack_max 579 && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { 580 unsigned int hash = hash_conntrack(orig); 581 /* Try dropping from this hash chain. */ 582 if (!early_drop(&nf_conntrack_hash[hash])) { 583 atomic_dec(&nf_conntrack_count); 584 if (net_ratelimit()) 585 printk(KERN_WARNING 586 "nf_conntrack: table full, dropping" 587 " packet.\n"); 588 return ERR_PTR(-ENOMEM); 589 } 590 } 591 592 /* find features needed by this conntrack. */ 593 features |= l3proto->get_features(orig); 594 595 DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); 596 597 read_lock_bh(&nf_ct_cache_lock); 598 599 if (unlikely(!nf_ct_cache[features].use)) { 600 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", 601 features); 602 goto out; 603 } 604 605 conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); 606 if (conntrack == NULL) { 607 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); 608 goto out; 609 } 610 611 memset(conntrack, 0, nf_ct_cache[features].size); 612 conntrack->features = features; 613 atomic_set(&conntrack->ct_general.use, 1); 614 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; 615 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; 616 /* Don't set timer yet: wait for confirmation */ 617 setup_timer(&conntrack->timeout, death_by_timeout, 618 (unsigned long)conntrack); 619 read_unlock_bh(&nf_ct_cache_lock); 620 621 return conntrack; 622out: 623 read_unlock_bh(&nf_ct_cache_lock); 624 atomic_dec(&nf_conntrack_count); 625 return conntrack; 626} 627 628struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, 629 const struct nf_conntrack_tuple *repl) 630{ 631 struct nf_conntrack_l3proto *l3proto; 632 struct nf_conn *ct; 633 634 rcu_read_lock(); 635 l3proto = __nf_ct_l3proto_find(orig->src.l3num); 636 ct = __nf_conntrack_alloc(orig, repl, l3proto, 0); 637 rcu_read_unlock(); 638 639 return ct; 640} 641EXPORT_SYMBOL_GPL(nf_conntrack_alloc); 642 643void nf_conntrack_free(struct nf_conn *conntrack) 644{ 645 u_int32_t features = conntrack->features; 646 NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); 647 nf_ct_ext_free(conntrack); 648 DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, 649 conntrack); 650 kmem_cache_free(nf_ct_cache[features].cachep, conntrack); 651 atomic_dec(&nf_conntrack_count); 652} 653EXPORT_SYMBOL_GPL(nf_conntrack_free); 654 655/* Allocate a new conntrack: we return -ENOMEM if classification 656 failed due to stress. Otherwise it really is unclassifiable. */ 657static struct nf_conntrack_tuple_hash * 658init_conntrack(const struct nf_conntrack_tuple *tuple, 659 struct nf_conntrack_l3proto *l3proto, 660 struct nf_conntrack_l4proto *l4proto, 661 struct sk_buff *skb, 662 unsigned int dataoff) 663{ 664 struct nf_conn *conntrack; 665 struct nf_conn_help *help; 666 struct nf_conntrack_tuple repl_tuple; 667 struct nf_conntrack_expect *exp; 668 u_int32_t features = 0; 669 670 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { 671 DEBUGP("Can't invert tuple.\n"); 672 return NULL; 673 } 674 675 conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features); 676 if (conntrack == NULL || IS_ERR(conntrack)) { 677 DEBUGP("Can't allocate conntrack.\n"); 678 return (struct nf_conntrack_tuple_hash *)conntrack; 679 } 680 681 if (!l4proto->new(conntrack, skb, dataoff)) { 682 nf_conntrack_free(conntrack); 683 DEBUGP("init conntrack: can't track with proto module\n"); 684 return NULL; 685 } 686 687 write_lock_bh(&nf_conntrack_lock); 688 exp = find_expectation(tuple); 689 if (exp) { 690 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", 691 conntrack, exp); 692 /* Welcome, Mr. Bond. We've been expecting you... */ 693 __set_bit(IPS_EXPECTED_BIT, &conntrack->status); 694 conntrack->master = exp->master; 695 if (exp->helper) { 696 help = nf_ct_ext_add(conntrack, NF_CT_EXT_HELPER, 697 GFP_ATOMIC); 698 if (help) 699 rcu_assign_pointer(help->helper, exp->helper); 700 else 701 DEBUGP("failed to add helper extension area"); 702 } 703 704#ifdef CONFIG_NF_CONNTRACK_MARK 705 conntrack->mark = exp->master->mark; 706#endif 707#ifdef CONFIG_NF_CONNTRACK_SECMARK 708 conntrack->secmark = exp->master->secmark; 709#endif 710 nf_conntrack_get(&conntrack->master->ct_general); 711 NF_CT_STAT_INC(expect_new); 712 } else { 713 struct nf_conntrack_helper *helper; 714 715 helper = __nf_ct_helper_find(&repl_tuple); 716 if (helper) { 717 help = nf_ct_ext_add(conntrack, NF_CT_EXT_HELPER, 718 GFP_ATOMIC); 719 if (help) 720 /* not in hash table yet, so not strictly 721 necessary */ 722 rcu_assign_pointer(help->helper, helper); 723 else 724 DEBUGP("failed to add helper extension area"); 725 } 726 NF_CT_STAT_INC(new); 727 } 728 729 /* Overload tuple linked list to put us in unconfirmed list. */ 730 list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); 731 732 write_unlock_bh(&nf_conntrack_lock); 733 734 if (exp) { 735 if (exp->expectfn) 736 exp->expectfn(conntrack, exp); 737 nf_conntrack_expect_put(exp); 738 } 739 740 return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; 741} 742 743/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ 744static inline struct nf_conn * 745resolve_normal_ct(struct sk_buff *skb, 746 unsigned int dataoff, 747 u_int16_t l3num, 748 u_int8_t protonum, 749 struct nf_conntrack_l3proto *l3proto, 750 struct nf_conntrack_l4proto *l4proto, 751 int *set_reply, 752 enum ip_conntrack_info *ctinfo) 753{ 754 struct nf_conntrack_tuple tuple; 755 struct nf_conntrack_tuple_hash *h; 756 struct nf_conn *ct; 757 758 if (!nf_ct_get_tuple(skb, skb_network_offset(skb), 759 dataoff, l3num, protonum, &tuple, l3proto, 760 l4proto)) { 761 DEBUGP("resolve_normal_ct: Can't get tuple\n"); 762 return NULL; 763 } 764 765 /* look for tuple match */ 766 h = nf_conntrack_find_get(&tuple, NULL); 767 if (!h) { 768 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff); 769 if (!h) 770 return NULL; 771 if (IS_ERR(h)) 772 return (void *)h; 773 } 774 ct = nf_ct_tuplehash_to_ctrack(h); 775 776 /* It exists; we have (non-exclusive) reference. */ 777 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { 778 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; 779 /* Please set reply bit if this packet OK */ 780 *set_reply = 1; 781 } else { 782 /* Once we've had two way comms, always ESTABLISHED. */ 783 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { 784 DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); 785 *ctinfo = IP_CT_ESTABLISHED; 786 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { 787 DEBUGP("nf_conntrack_in: related packet for %p\n", ct); 788 *ctinfo = IP_CT_RELATED; 789 } else { 790 DEBUGP("nf_conntrack_in: new packet for %p\n", ct); 791 *ctinfo = IP_CT_NEW; 792 } 793 *set_reply = 0; 794 } 795 skb->nfct = &ct->ct_general; 796 skb->nfctinfo = *ctinfo; 797 return ct; 798} 799 800unsigned int 801nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) 802{ 803 struct nf_conn *ct; 804 enum ip_conntrack_info ctinfo; 805 struct nf_conntrack_l3proto *l3proto; 806 struct nf_conntrack_l4proto *l4proto; 807 unsigned int dataoff; 808 u_int8_t protonum; 809 int set_reply = 0; 810 int ret; 811 812 /* Previously seen (loopback or untracked)? Ignore. */ 813 if ((*pskb)->nfct) { 814 NF_CT_STAT_INC_ATOMIC(ignore); 815 return NF_ACCEPT; 816 } 817 818 /* rcu_read_lock()ed by nf_hook_slow */ 819 l3proto = __nf_ct_l3proto_find((u_int16_t)pf); 820 821 if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { 822 DEBUGP("not prepared to track yet or error occured\n"); 823 return -ret; 824 } 825 826 l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum); 827 828 /* It may be an special packet, error, unclean... 829 * inverse of the return code tells to the netfilter 830 * core what to do with the packet. */ 831 if (l4proto->error != NULL && 832 (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { 833 NF_CT_STAT_INC_ATOMIC(error); 834 NF_CT_STAT_INC_ATOMIC(invalid); 835 return -ret; 836 } 837 838 ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto, 839 &set_reply, &ctinfo); 840 if (!ct) { 841 /* Not valid part of a connection */ 842 NF_CT_STAT_INC_ATOMIC(invalid); 843 return NF_ACCEPT; 844 } 845 846 if (IS_ERR(ct)) { 847 /* Too stressed to deal. */ 848 NF_CT_STAT_INC_ATOMIC(drop); 849 return NF_DROP; 850 } 851 852 NF_CT_ASSERT((*pskb)->nfct); 853 854 ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); 855 if (ret < 0) { 856 /* Invalid: inverse of the return code tells 857 * the netfilter core what to do */ 858 DEBUGP("nf_conntrack_in: Can't track with proto module\n"); 859 nf_conntrack_put((*pskb)->nfct); 860 (*pskb)->nfct = NULL; 861 NF_CT_STAT_INC_ATOMIC(invalid); 862 return -ret; 863 } 864 865 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) 866 nf_conntrack_event_cache(IPCT_STATUS, *pskb); 867 868 return ret; 869} 870EXPORT_SYMBOL_GPL(nf_conntrack_in); 871 872int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, 873 const struct nf_conntrack_tuple *orig) 874{ 875 int ret; 876 877 rcu_read_lock(); 878 ret = nf_ct_invert_tuple(inverse, orig, 879 __nf_ct_l3proto_find(orig->src.l3num), 880 __nf_ct_l4proto_find(orig->src.l3num, 881 orig->dst.protonum)); 882 rcu_read_unlock(); 883 return ret; 884} 885EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); 886 887/* Alter reply tuple (maybe alter helper). This is for NAT, and is 888 implicitly racy: see __nf_conntrack_confirm */ 889void nf_conntrack_alter_reply(struct nf_conn *ct, 890 const struct nf_conntrack_tuple *newreply) 891{ 892 struct nf_conn_help *help = nfct_help(ct); 893 struct nf_conntrack_helper *helper; 894 895 write_lock_bh(&nf_conntrack_lock); 896 /* Should be unconfirmed, so not in hash table yet */ 897 NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); 898 899 DEBUGP("Altering reply tuple of %p to ", ct); 900 NF_CT_DUMP_TUPLE(newreply); 901 902 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; 903 if (ct->master || (help && help->expecting != 0)) 904 goto out; 905 906 helper = __nf_ct_helper_find(newreply); 907 if (helper == NULL) { 908 if (help) 909 rcu_assign_pointer(help->helper, NULL); 910 goto out; 911 } 912 913 if (help == NULL) { 914 help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, GFP_ATOMIC); 915 if (help == NULL) { 916 DEBUGP("failed to add helper extension area"); 917 goto out; 918 } 919 } else { 920 memset(&help->help, 0, sizeof(help->help)); 921 } 922 923 rcu_assign_pointer(help->helper, helper); 924out: 925 write_unlock_bh(&nf_conntrack_lock); 926} 927EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); 928 929/* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ 930void __nf_ct_refresh_acct(struct nf_conn *ct, 931 enum ip_conntrack_info ctinfo, 932 const struct sk_buff *skb, 933 unsigned long extra_jiffies, 934 int do_acct) 935{ 936 int event = 0; 937 938 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); 939 NF_CT_ASSERT(skb); 940 941 write_lock_bh(&nf_conntrack_lock); 942 943 /* Only update if this is not a fixed timeout */ 944 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { 945 write_unlock_bh(&nf_conntrack_lock); 946 return; 947 } 948 949 /* If not in hash table, timer will not be active yet */ 950 if (!nf_ct_is_confirmed(ct)) { 951 ct->timeout.expires = extra_jiffies; 952 event = IPCT_REFRESH; 953 } else { 954 unsigned long newtime = jiffies + extra_jiffies; 955 956 /* Only update the timeout if the new timeout is at least 957 HZ jiffies from the old timeout. Need del_timer for race 958 avoidance (may already be dying). */ 959 if (newtime - ct->timeout.expires >= HZ 960 && del_timer(&ct->timeout)) { 961 ct->timeout.expires = newtime; 962 add_timer(&ct->timeout); 963 event = IPCT_REFRESH; 964 } 965 } 966 967#ifdef CONFIG_NF_CT_ACCT 968 if (do_acct) { 969 ct->counters[CTINFO2DIR(ctinfo)].packets++; 970 ct->counters[CTINFO2DIR(ctinfo)].bytes += 971 skb->len - skb_network_offset(skb); 972 973 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) 974 || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) 975 event |= IPCT_COUNTER_FILLING; 976 } 977#endif 978 979 write_unlock_bh(&nf_conntrack_lock); 980 981 /* must be unlocked when calling event cache */ 982 if (event) 983 nf_conntrack_event_cache(event, skb); 984} 985EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); 986 987#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) 988 989#include <linux/netfilter/nfnetlink.h> 990#include <linux/netfilter/nfnetlink_conntrack.h> 991#include <linux/mutex.h> 992 993 994/* Generic function for tcp/udp/sctp/dccp and alike. This needs to be 995 * in ip_conntrack_core, since we don't want the protocols to autoload 996 * or depend on ctnetlink */ 997int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, 998 const struct nf_conntrack_tuple *tuple) 999{ 1000 NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), 1001 &tuple->src.u.tcp.port); 1002 NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), 1003 &tuple->dst.u.tcp.port); 1004 return 0; 1005 1006nfattr_failure: 1007 return -1; 1008} 1009EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr); 1010 1011static const size_t cta_min_proto[CTA_PROTO_MAX] = { 1012 [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), 1013 [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) 1014}; 1015 1016int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], 1017 struct nf_conntrack_tuple *t) 1018{ 1019 if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) 1020 return -EINVAL; 1021 1022 if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) 1023 return -EINVAL; 1024 1025 t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); 1026 t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); 1027 1028 return 0; 1029} 1030EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple); 1031#endif 1032 1033/* Used by ipt_REJECT and ip6t_REJECT. */ 1034void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) 1035{ 1036 struct nf_conn *ct; 1037 enum ip_conntrack_info ctinfo; 1038 1039 /* This ICMP is in reverse direction to the packet which caused it */ 1040 ct = nf_ct_get(skb, &ctinfo); 1041 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) 1042 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; 1043 else 1044 ctinfo = IP_CT_RELATED; 1045 1046 /* Attach to new skbuff, and increment count */ 1047 nskb->nfct = &ct->ct_general; 1048 nskb->nfctinfo = ctinfo; 1049 nf_conntrack_get(nskb->nfct); 1050} 1051EXPORT_SYMBOL_GPL(__nf_conntrack_attach); 1052 1053static inline int 1054do_iter(const struct nf_conntrack_tuple_hash *i, 1055 int (*iter)(struct nf_conn *i, void *data), 1056 void *data) 1057{ 1058 return iter(nf_ct_tuplehash_to_ctrack(i), data); 1059} 1060 1061/* Bring out ya dead! */ 1062static struct nf_conn * 1063get_next_corpse(int (*iter)(struct nf_conn *i, void *data), 1064 void *data, unsigned int *bucket) 1065{ 1066 struct nf_conntrack_tuple_hash *h; 1067 struct nf_conn *ct; 1068 1069 write_lock_bh(&nf_conntrack_lock); 1070 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { 1071 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) { 1072 ct = nf_ct_tuplehash_to_ctrack(h); 1073 if (iter(ct, data)) 1074 goto found; 1075 } 1076 } 1077 list_for_each_entry(h, &unconfirmed, list) { 1078 ct = nf_ct_tuplehash_to_ctrack(h); 1079 if (iter(ct, data)) 1080 set_bit(IPS_DYING_BIT, &ct->status); 1081 } 1082 write_unlock_bh(&nf_conntrack_lock); 1083 return NULL; 1084found: 1085 atomic_inc(&ct->ct_general.use); 1086 write_unlock_bh(&nf_conntrack_lock); 1087 return ct; 1088} 1089 1090void 1091nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) 1092{ 1093 struct nf_conn *ct; 1094 unsigned int bucket = 0; 1095 1096 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { 1097 /* Time to push up daises... */ 1098 if (del_timer(&ct->timeout)) 1099 death_by_timeout((unsigned long)ct); 1100 /* ... else the timer will get him soon. */ 1101 1102 nf_ct_put(ct); 1103 } 1104} 1105EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); 1106 1107static int kill_all(struct nf_conn *i, void *data) 1108{ 1109 return 1; 1110} 1111 1112static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) 1113{ 1114 if (vmalloced) 1115 vfree(hash); 1116 else 1117 free_pages((unsigned long)hash, 1118 get_order(sizeof(struct list_head) * size)); 1119} 1120 1121void nf_conntrack_flush(void) 1122{ 1123 nf_ct_iterate_cleanup(kill_all, NULL); 1124} 1125EXPORT_SYMBOL_GPL(nf_conntrack_flush); 1126 1127/* Mishearing the voices in his head, our hero wonders how he's 1128 supposed to kill the mall. */ 1129void nf_conntrack_cleanup(void) 1130{ 1131 int i; 1132 1133 rcu_assign_pointer(ip_ct_attach, NULL); 1134 1135 /* This makes sure all current packets have passed through 1136 netfilter framework. Roll on, two-stage module 1137 delete... */ 1138 synchronize_net(); 1139 1140 nf_ct_event_cache_flush(); 1141 i_see_dead_people: 1142 nf_conntrack_flush(); 1143 if (atomic_read(&nf_conntrack_count) != 0) { 1144 schedule(); 1145 goto i_see_dead_people; 1146 } 1147 /* wait until all references to nf_conntrack_untracked are dropped */ 1148 while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) 1149 schedule(); 1150 1151 rcu_assign_pointer(nf_ct_destroy, NULL); 1152 1153 for (i = 0; i < NF_CT_F_NUM; i++) { 1154 if (nf_ct_cache[i].use == 0) 1155 continue; 1156 1157 NF_CT_ASSERT(nf_ct_cache[i].use == 1); 1158 nf_ct_cache[i].use = 1; 1159 nf_conntrack_unregister_cache(i); 1160 } 1161 kmem_cache_destroy(nf_conntrack_expect_cachep); 1162 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1163 nf_conntrack_htable_size); 1164 1165 nf_conntrack_proto_fini(); 1166 nf_conntrack_helper_fini(); 1167} 1168 1169static struct list_head *alloc_hashtable(int size, int *vmalloced) 1170{ 1171 struct list_head *hash; 1172 unsigned int i; 1173 1174 *vmalloced = 0; 1175 hash = (void*)__get_free_pages(GFP_KERNEL, 1176 get_order(sizeof(struct list_head) 1177 * size)); 1178 if (!hash) { 1179 *vmalloced = 1; 1180 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); 1181 hash = vmalloc(sizeof(struct list_head) * size); 1182 } 1183 1184 if (hash) 1185 for (i = 0; i < size; i++) 1186 INIT_LIST_HEAD(&hash[i]); 1187 1188 return hash; 1189} 1190 1191int set_hashsize(const char *val, struct kernel_param *kp) 1192{ 1193 int i, bucket, hashsize, vmalloced; 1194 int old_vmalloced, old_size; 1195 int rnd; 1196 struct list_head *hash, *old_hash; 1197 struct nf_conntrack_tuple_hash *h; 1198 1199 /* On boot, we can set this without any fancy locking. */ 1200 if (!nf_conntrack_htable_size) 1201 return param_set_uint(val, kp); 1202 1203 hashsize = simple_strtol(val, NULL, 0); 1204 if (!hashsize) 1205 return -EINVAL; 1206 1207 hash = alloc_hashtable(hashsize, &vmalloced); 1208 if (!hash) 1209 return -ENOMEM; 1210 1211 /* We have to rehahs for the new table anyway, so we also can 1212 * use a newrandom seed */ 1213 get_random_bytes(&rnd, 4); 1214 1215 write_lock_bh(&nf_conntrack_lock); 1216 for (i = 0; i < nf_conntrack_htable_size; i++) { 1217 while (!list_empty(&nf_conntrack_hash[i])) { 1218 h = list_entry(nf_conntrack_hash[i].next, 1219 struct nf_conntrack_tuple_hash, list); 1220 list_del(&h->list); 1221 bucket = __hash_conntrack(&h->tuple, hashsize, rnd); 1222 list_add_tail(&h->list, &hash[bucket]); 1223 } 1224 } 1225 old_size = nf_conntrack_htable_size; 1226 old_vmalloced = nf_conntrack_vmalloc; 1227 old_hash = nf_conntrack_hash; 1228 1229 nf_conntrack_htable_size = hashsize; 1230 nf_conntrack_vmalloc = vmalloced; 1231 nf_conntrack_hash = hash; 1232 nf_conntrack_hash_rnd = rnd; 1233 write_unlock_bh(&nf_conntrack_lock); 1234 1235 free_conntrack_hash(old_hash, old_vmalloced, old_size); 1236 return 0; 1237} 1238 1239module_param_call(hashsize, set_hashsize, param_get_uint, 1240 &nf_conntrack_htable_size, 0600); 1241 1242int __init nf_conntrack_init(void) 1243{ 1244 int ret; 1245 1246 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB 1247 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ 1248 if (!nf_conntrack_htable_size) { 1249 nf_conntrack_htable_size 1250 = (((num_physpages << PAGE_SHIFT) / 16384) 1251 / sizeof(struct list_head)); 1252 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) 1253 nf_conntrack_htable_size = 8192; 1254 if (nf_conntrack_htable_size < 16) 1255 nf_conntrack_htable_size = 16; 1256 } 1257 nf_conntrack_max = 8 * nf_conntrack_htable_size; 1258 1259 printk("nf_conntrack version %s (%u buckets, %d max)\n", 1260 NF_CONNTRACK_VERSION, nf_conntrack_htable_size, 1261 nf_conntrack_max); 1262 1263 nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, 1264 &nf_conntrack_vmalloc); 1265 if (!nf_conntrack_hash) { 1266 printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); 1267 goto err_out; 1268 } 1269 1270 ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", 1271 sizeof(struct nf_conn)); 1272 if (ret < 0) { 1273 printk(KERN_ERR "Unable to create nf_conn slab cache\n"); 1274 goto err_free_hash; 1275 } 1276 1277 nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", 1278 sizeof(struct nf_conntrack_expect), 1279 0, 0, NULL, NULL); 1280 if (!nf_conntrack_expect_cachep) { 1281 printk(KERN_ERR "Unable to create nf_expect slab cache\n"); 1282 goto err_free_conntrack_slab; 1283 } 1284 1285 ret = nf_conntrack_proto_init(); 1286 if (ret < 0) 1287 goto out_free_expect_slab; 1288 1289 ret = nf_conntrack_helper_init(); 1290 if (ret < 0) 1291 goto out_fini_proto; 1292 1293 /* For use by REJECT target */ 1294 rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach); 1295 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack); 1296 1297 /* Set up fake conntrack: 1298 - to never be deleted, not in any hashes */ 1299 atomic_set(&nf_conntrack_untracked.ct_general.use, 1); 1300 /* - and look it like as a confirmed connection */ 1301 set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); 1302 1303 return ret; 1304 1305out_fini_proto: 1306 nf_conntrack_proto_fini(); 1307out_free_expect_slab: 1308 kmem_cache_destroy(nf_conntrack_expect_cachep); 1309err_free_conntrack_slab: 1310 nf_conntrack_unregister_cache(NF_CT_F_BASIC); 1311err_free_hash: 1312 free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, 1313 nf_conntrack_htable_size); 1314err_out: 1315 return -ENOMEM; 1316} 1317