Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 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) 2002-2005 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 | * |
| 24 | * Derived from net/ipv4/netfilter/ip_conntrack_core.c |
| 25 | */ |
| 26 | |
| 27 | #include <linux/config.h> |
| 28 | #include <linux/types.h> |
| 29 | #include <linux/netfilter.h> |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/skbuff.h> |
| 32 | #include <linux/proc_fs.h> |
| 33 | #include <linux/vmalloc.h> |
| 34 | #include <linux/stddef.h> |
| 35 | #include <linux/slab.h> |
| 36 | #include <linux/random.h> |
| 37 | #include <linux/jhash.h> |
| 38 | #include <linux/err.h> |
| 39 | #include <linux/percpu.h> |
| 40 | #include <linux/moduleparam.h> |
| 41 | #include <linux/notifier.h> |
| 42 | #include <linux/kernel.h> |
| 43 | #include <linux/netdevice.h> |
| 44 | #include <linux/socket.h> |
| 45 | |
| 46 | /* This rwlock protects the main hash table, protocol/helper/expected |
| 47 | registrations, conntrack timers*/ |
| 48 | #define ASSERT_READ_LOCK(x) |
| 49 | #define ASSERT_WRITE_LOCK(x) |
| 50 | |
| 51 | #include <net/netfilter/nf_conntrack.h> |
| 52 | #include <net/netfilter/nf_conntrack_l3proto.h> |
| 53 | #include <net/netfilter/nf_conntrack_protocol.h> |
| 54 | #include <net/netfilter/nf_conntrack_helper.h> |
| 55 | #include <net/netfilter/nf_conntrack_core.h> |
| 56 | #include <linux/netfilter_ipv4/listhelp.h> |
| 57 | |
| 58 | #define NF_CONNTRACK_VERSION "0.4.1" |
| 59 | |
| 60 | #if 0 |
| 61 | #define DEBUGP printk |
| 62 | #else |
| 63 | #define DEBUGP(format, args...) |
| 64 | #endif |
| 65 | |
| 66 | DEFINE_RWLOCK(nf_conntrack_lock); |
| 67 | |
| 68 | /* nf_conntrack_standalone needs this */ |
| 69 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); |
| 70 | |
| 71 | void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; |
| 72 | LIST_HEAD(nf_conntrack_expect_list); |
| 73 | struct nf_conntrack_protocol **nf_ct_protos[PF_MAX]; |
| 74 | struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX]; |
| 75 | static LIST_HEAD(helpers); |
| 76 | unsigned int nf_conntrack_htable_size = 0; |
| 77 | int nf_conntrack_max; |
| 78 | struct list_head *nf_conntrack_hash; |
| 79 | static kmem_cache_t *nf_conntrack_expect_cachep; |
| 80 | struct nf_conn nf_conntrack_untracked; |
| 81 | unsigned int nf_ct_log_invalid; |
| 82 | static LIST_HEAD(unconfirmed); |
| 83 | static int nf_conntrack_vmalloc; |
| 84 | |
| 85 | #ifdef CONFIG_NF_CONNTRACK_EVENTS |
| 86 | struct notifier_block *nf_conntrack_chain; |
| 87 | struct notifier_block *nf_conntrack_expect_chain; |
| 88 | |
| 89 | DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); |
| 90 | |
| 91 | /* deliver cached events and clear cache entry - must be called with locally |
| 92 | * disabled softirqs */ |
| 93 | static inline void |
| 94 | __nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) |
| 95 | { |
| 96 | DEBUGP("ecache: delivering events for %p\n", ecache->ct); |
| 97 | if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) |
| 98 | && ecache->events) |
| 99 | notifier_call_chain(&nf_conntrack_chain, ecache->events, |
| 100 | ecache->ct); |
| 101 | |
| 102 | ecache->events = 0; |
| 103 | nf_ct_put(ecache->ct); |
| 104 | ecache->ct = NULL; |
| 105 | } |
| 106 | |
| 107 | /* Deliver all cached events for a particular conntrack. This is called |
| 108 | * by code prior to async packet handling for freeing the skb */ |
| 109 | void nf_ct_deliver_cached_events(const struct nf_conn *ct) |
| 110 | { |
| 111 | struct nf_conntrack_ecache *ecache; |
| 112 | |
| 113 | local_bh_disable(); |
| 114 | ecache = &__get_cpu_var(nf_conntrack_ecache); |
| 115 | if (ecache->ct == ct) |
| 116 | __nf_ct_deliver_cached_events(ecache); |
| 117 | local_bh_enable(); |
| 118 | } |
| 119 | |
| 120 | /* Deliver cached events for old pending events, if current conntrack != old */ |
| 121 | void __nf_ct_event_cache_init(struct nf_conn *ct) |
| 122 | { |
| 123 | struct nf_conntrack_ecache *ecache; |
| 124 | |
| 125 | /* take care of delivering potentially old events */ |
| 126 | ecache = &__get_cpu_var(nf_conntrack_ecache); |
| 127 | BUG_ON(ecache->ct == ct); |
| 128 | if (ecache->ct) |
| 129 | __nf_ct_deliver_cached_events(ecache); |
| 130 | /* initialize for this conntrack/packet */ |
| 131 | ecache->ct = ct; |
| 132 | nf_conntrack_get(&ct->ct_general); |
| 133 | } |
| 134 | |
| 135 | /* flush the event cache - touches other CPU's data and must not be called |
| 136 | * while packets are still passing through the code */ |
| 137 | static void nf_ct_event_cache_flush(void) |
| 138 | { |
| 139 | struct nf_conntrack_ecache *ecache; |
| 140 | int cpu; |
| 141 | |
| 142 | for_each_cpu(cpu) { |
| 143 | ecache = &per_cpu(nf_conntrack_ecache, cpu); |
| 144 | if (ecache->ct) |
| 145 | nf_ct_put(ecache->ct); |
| 146 | } |
| 147 | } |
| 148 | #else |
| 149 | static inline void nf_ct_event_cache_flush(void) {} |
| 150 | #endif /* CONFIG_NF_CONNTRACK_EVENTS */ |
| 151 | |
| 152 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); |
| 153 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); |
| 154 | |
| 155 | /* |
| 156 | * This scheme offers various size of "struct nf_conn" dependent on |
| 157 | * features(helper, nat, ...) |
| 158 | */ |
| 159 | |
| 160 | #define NF_CT_FEATURES_NAMELEN 256 |
| 161 | static struct { |
| 162 | /* name of slab cache. printed in /proc/slabinfo */ |
| 163 | char *name; |
| 164 | |
| 165 | /* size of slab cache */ |
| 166 | size_t size; |
| 167 | |
| 168 | /* slab cache pointer */ |
| 169 | kmem_cache_t *cachep; |
| 170 | |
| 171 | /* allocated slab cache + modules which uses this slab cache */ |
| 172 | int use; |
| 173 | |
| 174 | /* Initialization */ |
| 175 | int (*init_conntrack)(struct nf_conn *, u_int32_t); |
| 176 | |
| 177 | } nf_ct_cache[NF_CT_F_NUM]; |
| 178 | |
| 179 | /* protect members of nf_ct_cache except of "use" */ |
| 180 | DEFINE_RWLOCK(nf_ct_cache_lock); |
| 181 | |
| 182 | /* This avoids calling kmem_cache_create() with same name simultaneously */ |
| 183 | DECLARE_MUTEX(nf_ct_cache_mutex); |
| 184 | |
| 185 | extern struct nf_conntrack_protocol nf_conntrack_generic_protocol; |
| 186 | struct nf_conntrack_protocol * |
| 187 | nf_ct_find_proto(u_int16_t l3proto, u_int8_t protocol) |
| 188 | { |
| 189 | if (unlikely(nf_ct_protos[l3proto] == NULL)) |
| 190 | return &nf_conntrack_generic_protocol; |
| 191 | |
| 192 | return nf_ct_protos[l3proto][protocol]; |
| 193 | } |
| 194 | |
| 195 | static int nf_conntrack_hash_rnd_initted; |
| 196 | static unsigned int nf_conntrack_hash_rnd; |
| 197 | |
| 198 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, |
| 199 | unsigned int size, unsigned int rnd) |
| 200 | { |
| 201 | unsigned int a, b; |
| 202 | a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), |
| 203 | ((tuple->src.l3num) << 16) | tuple->dst.protonum); |
| 204 | b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), |
| 205 | (tuple->src.u.all << 16) | tuple->dst.u.all); |
| 206 | |
| 207 | return jhash_2words(a, b, rnd) % size; |
| 208 | } |
| 209 | |
| 210 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) |
| 211 | { |
| 212 | return __hash_conntrack(tuple, nf_conntrack_htable_size, |
| 213 | nf_conntrack_hash_rnd); |
| 214 | } |
| 215 | |
| 216 | /* Initialize "struct nf_conn" which has spaces for helper */ |
| 217 | static int |
| 218 | init_conntrack_for_helper(struct nf_conn *conntrack, u_int32_t features) |
| 219 | { |
| 220 | |
| 221 | conntrack->help = (union nf_conntrack_help *) |
| 222 | (((unsigned long)conntrack->data |
| 223 | + (__alignof__(union nf_conntrack_help) - 1)) |
| 224 | & (~((unsigned long)(__alignof__(union nf_conntrack_help) -1)))); |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | int nf_conntrack_register_cache(u_int32_t features, const char *name, |
| 229 | size_t size, |
| 230 | int (*init)(struct nf_conn *, u_int32_t)) |
| 231 | { |
| 232 | int ret = 0; |
| 233 | char *cache_name; |
| 234 | kmem_cache_t *cachep; |
| 235 | |
| 236 | DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", |
| 237 | features, name, size); |
| 238 | |
| 239 | if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { |
| 240 | DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", |
| 241 | features); |
| 242 | return -EINVAL; |
| 243 | } |
| 244 | |
| 245 | down(&nf_ct_cache_mutex); |
| 246 | |
| 247 | write_lock_bh(&nf_ct_cache_lock); |
| 248 | /* e.g: multiple helpers are loaded */ |
| 249 | if (nf_ct_cache[features].use > 0) { |
| 250 | DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); |
| 251 | if ((!strncmp(nf_ct_cache[features].name, name, |
| 252 | NF_CT_FEATURES_NAMELEN)) |
| 253 | && nf_ct_cache[features].size == size |
| 254 | && nf_ct_cache[features].init_conntrack == init) { |
| 255 | DEBUGP("nf_conntrack_register_cache: reusing.\n"); |
| 256 | nf_ct_cache[features].use++; |
| 257 | ret = 0; |
| 258 | } else |
| 259 | ret = -EBUSY; |
| 260 | |
| 261 | write_unlock_bh(&nf_ct_cache_lock); |
| 262 | up(&nf_ct_cache_mutex); |
| 263 | return ret; |
| 264 | } |
| 265 | write_unlock_bh(&nf_ct_cache_lock); |
| 266 | |
| 267 | /* |
| 268 | * The memory space for name of slab cache must be alive until |
| 269 | * cache is destroyed. |
| 270 | */ |
| 271 | cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); |
| 272 | if (cache_name == NULL) { |
| 273 | DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); |
| 274 | ret = -ENOMEM; |
| 275 | goto out_up_mutex; |
| 276 | } |
| 277 | |
| 278 | if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) |
| 279 | >= NF_CT_FEATURES_NAMELEN) { |
| 280 | printk("nf_conntrack_register_cache: name too long\n"); |
| 281 | ret = -EINVAL; |
| 282 | goto out_free_name; |
| 283 | } |
| 284 | |
| 285 | cachep = kmem_cache_create(cache_name, size, 0, 0, |
| 286 | NULL, NULL); |
| 287 | if (!cachep) { |
| 288 | printk("nf_conntrack_register_cache: Can't create slab cache " |
| 289 | "for the features = 0x%x\n", features); |
| 290 | ret = -ENOMEM; |
| 291 | goto out_free_name; |
| 292 | } |
| 293 | |
| 294 | write_lock_bh(&nf_ct_cache_lock); |
| 295 | nf_ct_cache[features].use = 1; |
| 296 | nf_ct_cache[features].size = size; |
| 297 | nf_ct_cache[features].init_conntrack = init; |
| 298 | nf_ct_cache[features].cachep = cachep; |
| 299 | nf_ct_cache[features].name = cache_name; |
| 300 | write_unlock_bh(&nf_ct_cache_lock); |
| 301 | |
| 302 | goto out_up_mutex; |
| 303 | |
| 304 | out_free_name: |
| 305 | kfree(cache_name); |
| 306 | out_up_mutex: |
| 307 | up(&nf_ct_cache_mutex); |
| 308 | return ret; |
| 309 | } |
| 310 | |
| 311 | /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ |
| 312 | void nf_conntrack_unregister_cache(u_int32_t features) |
| 313 | { |
| 314 | kmem_cache_t *cachep; |
| 315 | char *name; |
| 316 | |
| 317 | /* |
| 318 | * This assures that kmem_cache_create() isn't called before destroying |
| 319 | * slab cache. |
| 320 | */ |
| 321 | DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); |
| 322 | down(&nf_ct_cache_mutex); |
| 323 | |
| 324 | write_lock_bh(&nf_ct_cache_lock); |
| 325 | if (--nf_ct_cache[features].use > 0) { |
| 326 | write_unlock_bh(&nf_ct_cache_lock); |
| 327 | up(&nf_ct_cache_mutex); |
| 328 | return; |
| 329 | } |
| 330 | cachep = nf_ct_cache[features].cachep; |
| 331 | name = nf_ct_cache[features].name; |
| 332 | nf_ct_cache[features].cachep = NULL; |
| 333 | nf_ct_cache[features].name = NULL; |
| 334 | nf_ct_cache[features].init_conntrack = NULL; |
| 335 | nf_ct_cache[features].size = 0; |
| 336 | write_unlock_bh(&nf_ct_cache_lock); |
| 337 | |
| 338 | synchronize_net(); |
| 339 | |
| 340 | kmem_cache_destroy(cachep); |
| 341 | kfree(name); |
| 342 | |
| 343 | up(&nf_ct_cache_mutex); |
| 344 | } |
| 345 | |
| 346 | int |
| 347 | nf_ct_get_tuple(const struct sk_buff *skb, |
| 348 | unsigned int nhoff, |
| 349 | unsigned int dataoff, |
| 350 | u_int16_t l3num, |
| 351 | u_int8_t protonum, |
| 352 | struct nf_conntrack_tuple *tuple, |
| 353 | const struct nf_conntrack_l3proto *l3proto, |
| 354 | const struct nf_conntrack_protocol *protocol) |
| 355 | { |
| 356 | NF_CT_TUPLE_U_BLANK(tuple); |
| 357 | |
| 358 | tuple->src.l3num = l3num; |
| 359 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) |
| 360 | return 0; |
| 361 | |
| 362 | tuple->dst.protonum = protonum; |
| 363 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; |
| 364 | |
| 365 | return protocol->pkt_to_tuple(skb, dataoff, tuple); |
| 366 | } |
| 367 | |
| 368 | int |
| 369 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, |
| 370 | const struct nf_conntrack_tuple *orig, |
| 371 | const struct nf_conntrack_l3proto *l3proto, |
| 372 | const struct nf_conntrack_protocol *protocol) |
| 373 | { |
| 374 | NF_CT_TUPLE_U_BLANK(inverse); |
| 375 | |
| 376 | inverse->src.l3num = orig->src.l3num; |
| 377 | if (l3proto->invert_tuple(inverse, orig) == 0) |
| 378 | return 0; |
| 379 | |
| 380 | inverse->dst.dir = !orig->dst.dir; |
| 381 | |
| 382 | inverse->dst.protonum = orig->dst.protonum; |
| 383 | return protocol->invert_tuple(inverse, orig); |
| 384 | } |
| 385 | |
| 386 | /* nf_conntrack_expect helper functions */ |
| 387 | static void nf_ct_unlink_expect(struct nf_conntrack_expect *exp) |
| 388 | { |
| 389 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); |
Patrick McHardy | 4a59a81 | 2005-11-16 23:14:19 -0800 | [diff] [blame] | 390 | NF_CT_ASSERT(!timer_pending(&exp->timeout)); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 391 | list_del(&exp->list); |
| 392 | NF_CT_STAT_INC(expect_delete); |
| 393 | exp->master->expecting--; |
| 394 | nf_conntrack_expect_put(exp); |
| 395 | } |
| 396 | |
| 397 | static void expectation_timed_out(unsigned long ul_expect) |
| 398 | { |
| 399 | struct nf_conntrack_expect *exp = (void *)ul_expect; |
| 400 | |
| 401 | write_lock_bh(&nf_conntrack_lock); |
| 402 | nf_ct_unlink_expect(exp); |
| 403 | write_unlock_bh(&nf_conntrack_lock); |
| 404 | nf_conntrack_expect_put(exp); |
| 405 | } |
| 406 | |
| 407 | /* If an expectation for this connection is found, it gets delete from |
| 408 | * global list then returned. */ |
| 409 | static struct nf_conntrack_expect * |
| 410 | find_expectation(const struct nf_conntrack_tuple *tuple) |
| 411 | { |
| 412 | struct nf_conntrack_expect *i; |
| 413 | |
| 414 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { |
| 415 | /* If master is not in hash table yet (ie. packet hasn't left |
| 416 | this machine yet), how can other end know about expected? |
| 417 | Hence these are not the droids you are looking for (if |
| 418 | master ct never got confirmed, we'd hold a reference to it |
| 419 | and weird things would happen to future packets). */ |
| 420 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) |
| 421 | && nf_ct_is_confirmed(i->master)) { |
| 422 | if (i->flags & NF_CT_EXPECT_PERMANENT) { |
| 423 | atomic_inc(&i->use); |
| 424 | return i; |
| 425 | } else if (del_timer(&i->timeout)) { |
| 426 | nf_ct_unlink_expect(i); |
| 427 | return i; |
| 428 | } |
| 429 | } |
| 430 | } |
| 431 | return NULL; |
| 432 | } |
| 433 | |
| 434 | /* delete all expectations for this conntrack */ |
| 435 | static void remove_expectations(struct nf_conn *ct) |
| 436 | { |
| 437 | struct nf_conntrack_expect *i, *tmp; |
| 438 | |
| 439 | /* Optimization: most connection never expect any others. */ |
| 440 | if (ct->expecting == 0) |
| 441 | return; |
| 442 | |
| 443 | list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) { |
| 444 | if (i->master == ct && del_timer(&i->timeout)) { |
| 445 | nf_ct_unlink_expect(i); |
| 446 | nf_conntrack_expect_put(i); |
| 447 | } |
| 448 | } |
| 449 | } |
| 450 | |
| 451 | static void |
| 452 | clean_from_lists(struct nf_conn *ct) |
| 453 | { |
| 454 | unsigned int ho, hr; |
| 455 | |
| 456 | DEBUGP("clean_from_lists(%p)\n", ct); |
| 457 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); |
| 458 | |
| 459 | ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
| 460 | hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| 461 | LIST_DELETE(&nf_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]); |
| 462 | LIST_DELETE(&nf_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]); |
| 463 | |
| 464 | /* Destroy all pending expectations */ |
| 465 | remove_expectations(ct); |
| 466 | } |
| 467 | |
| 468 | static void |
| 469 | destroy_conntrack(struct nf_conntrack *nfct) |
| 470 | { |
| 471 | struct nf_conn *ct = (struct nf_conn *)nfct; |
| 472 | struct nf_conntrack_l3proto *l3proto; |
| 473 | struct nf_conntrack_protocol *proto; |
| 474 | |
| 475 | DEBUGP("destroy_conntrack(%p)\n", ct); |
| 476 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); |
| 477 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); |
| 478 | |
| 479 | nf_conntrack_event(IPCT_DESTROY, ct); |
| 480 | set_bit(IPS_DYING_BIT, &ct->status); |
| 481 | |
| 482 | /* To make sure we don't get any weird locking issues here: |
| 483 | * destroy_conntrack() MUST NOT be called with a write lock |
| 484 | * to nf_conntrack_lock!!! -HW */ |
| 485 | l3proto = nf_ct_find_l3proto(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); |
| 486 | if (l3proto && l3proto->destroy) |
| 487 | l3proto->destroy(ct); |
| 488 | |
| 489 | proto = nf_ct_find_proto(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, |
| 490 | ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); |
| 491 | if (proto && proto->destroy) |
| 492 | proto->destroy(ct); |
| 493 | |
| 494 | if (nf_conntrack_destroyed) |
| 495 | nf_conntrack_destroyed(ct); |
| 496 | |
| 497 | write_lock_bh(&nf_conntrack_lock); |
| 498 | /* Expectations will have been removed in clean_from_lists, |
| 499 | * except TFTP can create an expectation on the first packet, |
| 500 | * before connection is in the list, so we need to clean here, |
| 501 | * too. */ |
| 502 | remove_expectations(ct); |
| 503 | |
| 504 | /* We overload first tuple to link into unconfirmed list. */ |
| 505 | if (!nf_ct_is_confirmed(ct)) { |
| 506 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); |
| 507 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); |
| 508 | } |
| 509 | |
| 510 | NF_CT_STAT_INC(delete); |
| 511 | write_unlock_bh(&nf_conntrack_lock); |
| 512 | |
| 513 | if (ct->master) |
| 514 | nf_ct_put(ct->master); |
| 515 | |
| 516 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); |
| 517 | nf_conntrack_free(ct); |
| 518 | } |
| 519 | |
| 520 | static void death_by_timeout(unsigned long ul_conntrack) |
| 521 | { |
| 522 | struct nf_conn *ct = (void *)ul_conntrack; |
| 523 | |
| 524 | write_lock_bh(&nf_conntrack_lock); |
| 525 | /* Inside lock so preempt is disabled on module removal path. |
| 526 | * Otherwise we can get spurious warnings. */ |
| 527 | NF_CT_STAT_INC(delete_list); |
| 528 | clean_from_lists(ct); |
| 529 | write_unlock_bh(&nf_conntrack_lock); |
| 530 | nf_ct_put(ct); |
| 531 | } |
| 532 | |
| 533 | static inline int |
| 534 | conntrack_tuple_cmp(const struct nf_conntrack_tuple_hash *i, |
| 535 | const struct nf_conntrack_tuple *tuple, |
| 536 | const struct nf_conn *ignored_conntrack) |
| 537 | { |
| 538 | ASSERT_READ_LOCK(&nf_conntrack_lock); |
| 539 | return nf_ct_tuplehash_to_ctrack(i) != ignored_conntrack |
| 540 | && nf_ct_tuple_equal(tuple, &i->tuple); |
| 541 | } |
| 542 | |
| 543 | static struct nf_conntrack_tuple_hash * |
| 544 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
| 545 | const struct nf_conn *ignored_conntrack) |
| 546 | { |
| 547 | struct nf_conntrack_tuple_hash *h; |
| 548 | unsigned int hash = hash_conntrack(tuple); |
| 549 | |
| 550 | ASSERT_READ_LOCK(&nf_conntrack_lock); |
| 551 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) { |
| 552 | if (conntrack_tuple_cmp(h, tuple, ignored_conntrack)) { |
| 553 | NF_CT_STAT_INC(found); |
| 554 | return h; |
| 555 | } |
| 556 | NF_CT_STAT_INC(searched); |
| 557 | } |
| 558 | |
| 559 | return NULL; |
| 560 | } |
| 561 | |
| 562 | /* Find a connection corresponding to a tuple. */ |
| 563 | struct nf_conntrack_tuple_hash * |
| 564 | nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, |
| 565 | const struct nf_conn *ignored_conntrack) |
| 566 | { |
| 567 | struct nf_conntrack_tuple_hash *h; |
| 568 | |
| 569 | read_lock_bh(&nf_conntrack_lock); |
| 570 | h = __nf_conntrack_find(tuple, ignored_conntrack); |
| 571 | if (h) |
| 572 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); |
| 573 | read_unlock_bh(&nf_conntrack_lock); |
| 574 | |
| 575 | return h; |
| 576 | } |
| 577 | |
| 578 | /* Confirm a connection given skb; places it in hash table */ |
| 579 | int |
| 580 | __nf_conntrack_confirm(struct sk_buff **pskb) |
| 581 | { |
| 582 | unsigned int hash, repl_hash; |
| 583 | struct nf_conn *ct; |
| 584 | enum ip_conntrack_info ctinfo; |
| 585 | |
| 586 | ct = nf_ct_get(*pskb, &ctinfo); |
| 587 | |
| 588 | /* ipt_REJECT uses nf_conntrack_attach to attach related |
| 589 | ICMP/TCP RST packets in other direction. Actual packet |
| 590 | which created connection will be IP_CT_NEW or for an |
| 591 | expected connection, IP_CT_RELATED. */ |
| 592 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) |
| 593 | return NF_ACCEPT; |
| 594 | |
| 595 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
| 596 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| 597 | |
| 598 | /* We're not in hash table, and we refuse to set up related |
| 599 | connections for unconfirmed conns. But packet copies and |
| 600 | REJECT will give spurious warnings here. */ |
| 601 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ |
| 602 | |
| 603 | /* No external references means noone else could have |
| 604 | confirmed us. */ |
| 605 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); |
| 606 | DEBUGP("Confirming conntrack %p\n", ct); |
| 607 | |
| 608 | write_lock_bh(&nf_conntrack_lock); |
| 609 | |
| 610 | /* See if there's one in the list already, including reverse: |
| 611 | NAT could have grabbed it without realizing, since we're |
| 612 | not in the hash. If there is, we lost race. */ |
| 613 | if (!LIST_FIND(&nf_conntrack_hash[hash], |
| 614 | conntrack_tuple_cmp, |
| 615 | struct nf_conntrack_tuple_hash *, |
| 616 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL) |
| 617 | && !LIST_FIND(&nf_conntrack_hash[repl_hash], |
| 618 | conntrack_tuple_cmp, |
| 619 | struct nf_conntrack_tuple_hash *, |
| 620 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) { |
| 621 | /* Remove from unconfirmed list */ |
| 622 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); |
| 623 | |
| 624 | list_prepend(&nf_conntrack_hash[hash], |
| 625 | &ct->tuplehash[IP_CT_DIR_ORIGINAL]); |
| 626 | list_prepend(&nf_conntrack_hash[repl_hash], |
| 627 | &ct->tuplehash[IP_CT_DIR_REPLY]); |
| 628 | /* Timer relative to confirmation time, not original |
| 629 | setting time, otherwise we'd get timer wrap in |
| 630 | weird delay cases. */ |
| 631 | ct->timeout.expires += jiffies; |
| 632 | add_timer(&ct->timeout); |
| 633 | atomic_inc(&ct->ct_general.use); |
| 634 | set_bit(IPS_CONFIRMED_BIT, &ct->status); |
| 635 | NF_CT_STAT_INC(insert); |
| 636 | write_unlock_bh(&nf_conntrack_lock); |
| 637 | if (ct->helper) |
| 638 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); |
| 639 | #ifdef CONFIG_NF_NAT_NEEDED |
| 640 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || |
| 641 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) |
| 642 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); |
| 643 | #endif |
| 644 | nf_conntrack_event_cache(master_ct(ct) ? |
| 645 | IPCT_RELATED : IPCT_NEW, *pskb); |
| 646 | return NF_ACCEPT; |
| 647 | } |
| 648 | |
| 649 | NF_CT_STAT_INC(insert_failed); |
| 650 | write_unlock_bh(&nf_conntrack_lock); |
| 651 | return NF_DROP; |
| 652 | } |
| 653 | |
| 654 | /* Returns true if a connection correspondings to the tuple (required |
| 655 | for NAT). */ |
| 656 | int |
| 657 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, |
| 658 | const struct nf_conn *ignored_conntrack) |
| 659 | { |
| 660 | struct nf_conntrack_tuple_hash *h; |
| 661 | |
| 662 | read_lock_bh(&nf_conntrack_lock); |
| 663 | h = __nf_conntrack_find(tuple, ignored_conntrack); |
| 664 | read_unlock_bh(&nf_conntrack_lock); |
| 665 | |
| 666 | return h != NULL; |
| 667 | } |
| 668 | |
| 669 | /* There's a small race here where we may free a just-assured |
| 670 | connection. Too bad: we're in trouble anyway. */ |
| 671 | static inline int unreplied(const struct nf_conntrack_tuple_hash *i) |
| 672 | { |
| 673 | return !(test_bit(IPS_ASSURED_BIT, |
| 674 | &nf_ct_tuplehash_to_ctrack(i)->status)); |
| 675 | } |
| 676 | |
| 677 | static int early_drop(struct list_head *chain) |
| 678 | { |
| 679 | /* Traverse backwards: gives us oldest, which is roughly LRU */ |
| 680 | struct nf_conntrack_tuple_hash *h; |
| 681 | struct nf_conn *ct = NULL; |
| 682 | int dropped = 0; |
| 683 | |
| 684 | read_lock_bh(&nf_conntrack_lock); |
| 685 | h = LIST_FIND_B(chain, unreplied, struct nf_conntrack_tuple_hash *); |
| 686 | if (h) { |
| 687 | ct = nf_ct_tuplehash_to_ctrack(h); |
| 688 | atomic_inc(&ct->ct_general.use); |
| 689 | } |
| 690 | read_unlock_bh(&nf_conntrack_lock); |
| 691 | |
| 692 | if (!ct) |
| 693 | return dropped; |
| 694 | |
| 695 | if (del_timer(&ct->timeout)) { |
| 696 | death_by_timeout((unsigned long)ct); |
| 697 | dropped = 1; |
| 698 | NF_CT_STAT_INC(early_drop); |
| 699 | } |
| 700 | nf_ct_put(ct); |
| 701 | return dropped; |
| 702 | } |
| 703 | |
| 704 | static inline int helper_cmp(const struct nf_conntrack_helper *i, |
| 705 | const struct nf_conntrack_tuple *rtuple) |
| 706 | { |
| 707 | return nf_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask); |
| 708 | } |
| 709 | |
| 710 | static struct nf_conntrack_helper * |
| 711 | nf_ct_find_helper(const struct nf_conntrack_tuple *tuple) |
| 712 | { |
| 713 | return LIST_FIND(&helpers, helper_cmp, |
| 714 | struct nf_conntrack_helper *, |
| 715 | tuple); |
| 716 | } |
| 717 | |
| 718 | static struct nf_conn * |
| 719 | __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, |
| 720 | const struct nf_conntrack_tuple *repl, |
| 721 | const struct nf_conntrack_l3proto *l3proto) |
| 722 | { |
| 723 | struct nf_conn *conntrack = NULL; |
| 724 | u_int32_t features = 0; |
| 725 | |
| 726 | if (!nf_conntrack_hash_rnd_initted) { |
| 727 | get_random_bytes(&nf_conntrack_hash_rnd, 4); |
| 728 | nf_conntrack_hash_rnd_initted = 1; |
| 729 | } |
| 730 | |
| 731 | if (nf_conntrack_max |
| 732 | && atomic_read(&nf_conntrack_count) >= nf_conntrack_max) { |
| 733 | unsigned int hash = hash_conntrack(orig); |
| 734 | /* Try dropping from this hash chain. */ |
| 735 | if (!early_drop(&nf_conntrack_hash[hash])) { |
| 736 | if (net_ratelimit()) |
| 737 | printk(KERN_WARNING |
| 738 | "nf_conntrack: table full, dropping" |
| 739 | " packet.\n"); |
| 740 | return ERR_PTR(-ENOMEM); |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | /* find features needed by this conntrack. */ |
| 745 | features = l3proto->get_features(orig); |
| 746 | read_lock_bh(&nf_conntrack_lock); |
| 747 | if (nf_ct_find_helper(repl) != NULL) |
| 748 | features |= NF_CT_F_HELP; |
| 749 | read_unlock_bh(&nf_conntrack_lock); |
| 750 | |
| 751 | DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); |
| 752 | |
| 753 | read_lock_bh(&nf_ct_cache_lock); |
| 754 | |
| 755 | if (!nf_ct_cache[features].use) { |
| 756 | DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", |
| 757 | features); |
| 758 | goto out; |
| 759 | } |
| 760 | |
| 761 | conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); |
| 762 | if (conntrack == NULL) { |
| 763 | DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); |
| 764 | goto out; |
| 765 | } |
| 766 | |
| 767 | memset(conntrack, 0, nf_ct_cache[features].size); |
| 768 | conntrack->features = features; |
| 769 | if (nf_ct_cache[features].init_conntrack && |
| 770 | nf_ct_cache[features].init_conntrack(conntrack, features) < 0) { |
| 771 | DEBUGP("nf_conntrack_alloc: failed to init\n"); |
| 772 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); |
| 773 | conntrack = NULL; |
| 774 | goto out; |
| 775 | } |
| 776 | |
| 777 | atomic_set(&conntrack->ct_general.use, 1); |
| 778 | conntrack->ct_general.destroy = destroy_conntrack; |
| 779 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; |
| 780 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; |
| 781 | /* Don't set timer yet: wait for confirmation */ |
| 782 | init_timer(&conntrack->timeout); |
| 783 | conntrack->timeout.data = (unsigned long)conntrack; |
| 784 | conntrack->timeout.function = death_by_timeout; |
| 785 | |
| 786 | atomic_inc(&nf_conntrack_count); |
| 787 | out: |
| 788 | read_unlock_bh(&nf_ct_cache_lock); |
| 789 | return conntrack; |
| 790 | } |
| 791 | |
| 792 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, |
| 793 | const struct nf_conntrack_tuple *repl) |
| 794 | { |
| 795 | struct nf_conntrack_l3proto *l3proto; |
| 796 | |
| 797 | l3proto = nf_ct_find_l3proto(orig->src.l3num); |
| 798 | return __nf_conntrack_alloc(orig, repl, l3proto); |
| 799 | } |
| 800 | |
| 801 | void nf_conntrack_free(struct nf_conn *conntrack) |
| 802 | { |
| 803 | u_int32_t features = conntrack->features; |
| 804 | NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); |
| 805 | DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, |
| 806 | conntrack); |
| 807 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); |
| 808 | atomic_dec(&nf_conntrack_count); |
| 809 | } |
| 810 | |
| 811 | /* Allocate a new conntrack: we return -ENOMEM if classification |
| 812 | failed due to stress. Otherwise it really is unclassifiable. */ |
| 813 | static struct nf_conntrack_tuple_hash * |
| 814 | init_conntrack(const struct nf_conntrack_tuple *tuple, |
| 815 | struct nf_conntrack_l3proto *l3proto, |
| 816 | struct nf_conntrack_protocol *protocol, |
| 817 | struct sk_buff *skb, |
| 818 | unsigned int dataoff) |
| 819 | { |
| 820 | struct nf_conn *conntrack; |
| 821 | struct nf_conntrack_tuple repl_tuple; |
| 822 | struct nf_conntrack_expect *exp; |
| 823 | |
| 824 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, protocol)) { |
| 825 | DEBUGP("Can't invert tuple.\n"); |
| 826 | return NULL; |
| 827 | } |
| 828 | |
| 829 | conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto); |
| 830 | if (conntrack == NULL || IS_ERR(conntrack)) { |
| 831 | DEBUGP("Can't allocate conntrack.\n"); |
| 832 | return (struct nf_conntrack_tuple_hash *)conntrack; |
| 833 | } |
| 834 | |
| 835 | if (!protocol->new(conntrack, skb, dataoff)) { |
| 836 | nf_conntrack_free(conntrack); |
| 837 | DEBUGP("init conntrack: can't track with proto module\n"); |
| 838 | return NULL; |
| 839 | } |
| 840 | |
| 841 | write_lock_bh(&nf_conntrack_lock); |
| 842 | exp = find_expectation(tuple); |
| 843 | |
| 844 | if (exp) { |
| 845 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", |
| 846 | conntrack, exp); |
| 847 | /* Welcome, Mr. Bond. We've been expecting you... */ |
| 848 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); |
| 849 | conntrack->master = exp->master; |
| 850 | #ifdef CONFIG_NF_CONNTRACK_MARK |
| 851 | conntrack->mark = exp->master->mark; |
| 852 | #endif |
| 853 | nf_conntrack_get(&conntrack->master->ct_general); |
| 854 | NF_CT_STAT_INC(expect_new); |
| 855 | } else { |
| 856 | conntrack->helper = nf_ct_find_helper(&repl_tuple); |
| 857 | |
| 858 | NF_CT_STAT_INC(new); |
| 859 | } |
| 860 | |
| 861 | /* Overload tuple linked list to put us in unconfirmed list. */ |
| 862 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); |
| 863 | |
| 864 | write_unlock_bh(&nf_conntrack_lock); |
| 865 | |
| 866 | if (exp) { |
| 867 | if (exp->expectfn) |
| 868 | exp->expectfn(conntrack, exp); |
| 869 | nf_conntrack_expect_put(exp); |
| 870 | } |
| 871 | |
| 872 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; |
| 873 | } |
| 874 | |
| 875 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ |
| 876 | static inline struct nf_conn * |
| 877 | resolve_normal_ct(struct sk_buff *skb, |
| 878 | unsigned int dataoff, |
| 879 | u_int16_t l3num, |
| 880 | u_int8_t protonum, |
| 881 | struct nf_conntrack_l3proto *l3proto, |
| 882 | struct nf_conntrack_protocol *proto, |
| 883 | int *set_reply, |
| 884 | enum ip_conntrack_info *ctinfo) |
| 885 | { |
| 886 | struct nf_conntrack_tuple tuple; |
| 887 | struct nf_conntrack_tuple_hash *h; |
| 888 | struct nf_conn *ct; |
| 889 | |
| 890 | if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), |
| 891 | dataoff, l3num, protonum, &tuple, l3proto, |
| 892 | proto)) { |
| 893 | DEBUGP("resolve_normal_ct: Can't get tuple\n"); |
| 894 | return NULL; |
| 895 | } |
| 896 | |
| 897 | /* look for tuple match */ |
| 898 | h = nf_conntrack_find_get(&tuple, NULL); |
| 899 | if (!h) { |
| 900 | h = init_conntrack(&tuple, l3proto, proto, skb, dataoff); |
| 901 | if (!h) |
| 902 | return NULL; |
| 903 | if (IS_ERR(h)) |
| 904 | return (void *)h; |
| 905 | } |
| 906 | ct = nf_ct_tuplehash_to_ctrack(h); |
| 907 | |
| 908 | /* It exists; we have (non-exclusive) reference. */ |
| 909 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { |
| 910 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; |
| 911 | /* Please set reply bit if this packet OK */ |
| 912 | *set_reply = 1; |
| 913 | } else { |
| 914 | /* Once we've had two way comms, always ESTABLISHED. */ |
| 915 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { |
| 916 | DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); |
| 917 | *ctinfo = IP_CT_ESTABLISHED; |
| 918 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { |
| 919 | DEBUGP("nf_conntrack_in: related packet for %p\n", ct); |
| 920 | *ctinfo = IP_CT_RELATED; |
| 921 | } else { |
| 922 | DEBUGP("nf_conntrack_in: new packet for %p\n", ct); |
| 923 | *ctinfo = IP_CT_NEW; |
| 924 | } |
| 925 | *set_reply = 0; |
| 926 | } |
| 927 | skb->nfct = &ct->ct_general; |
| 928 | skb->nfctinfo = *ctinfo; |
| 929 | return ct; |
| 930 | } |
| 931 | |
| 932 | unsigned int |
| 933 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) |
| 934 | { |
| 935 | struct nf_conn *ct; |
| 936 | enum ip_conntrack_info ctinfo; |
| 937 | struct nf_conntrack_l3proto *l3proto; |
| 938 | struct nf_conntrack_protocol *proto; |
| 939 | unsigned int dataoff; |
| 940 | u_int8_t protonum; |
| 941 | int set_reply = 0; |
| 942 | int ret; |
| 943 | |
| 944 | /* Previously seen (loopback or untracked)? Ignore. */ |
| 945 | if ((*pskb)->nfct) { |
| 946 | NF_CT_STAT_INC(ignore); |
| 947 | return NF_ACCEPT; |
| 948 | } |
| 949 | |
| 950 | l3proto = nf_ct_find_l3proto((u_int16_t)pf); |
| 951 | if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { |
| 952 | DEBUGP("not prepared to track yet or error occured\n"); |
| 953 | return -ret; |
| 954 | } |
| 955 | |
| 956 | proto = nf_ct_find_proto((u_int16_t)pf, protonum); |
| 957 | |
| 958 | /* It may be an special packet, error, unclean... |
| 959 | * inverse of the return code tells to the netfilter |
| 960 | * core what to do with the packet. */ |
| 961 | if (proto->error != NULL && |
| 962 | (ret = proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { |
| 963 | NF_CT_STAT_INC(error); |
| 964 | NF_CT_STAT_INC(invalid); |
| 965 | return -ret; |
| 966 | } |
| 967 | |
| 968 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, proto, |
| 969 | &set_reply, &ctinfo); |
| 970 | if (!ct) { |
| 971 | /* Not valid part of a connection */ |
| 972 | NF_CT_STAT_INC(invalid); |
| 973 | return NF_ACCEPT; |
| 974 | } |
| 975 | |
| 976 | if (IS_ERR(ct)) { |
| 977 | /* Too stressed to deal. */ |
| 978 | NF_CT_STAT_INC(drop); |
| 979 | return NF_DROP; |
| 980 | } |
| 981 | |
| 982 | NF_CT_ASSERT((*pskb)->nfct); |
| 983 | |
| 984 | ret = proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); |
| 985 | if (ret < 0) { |
| 986 | /* Invalid: inverse of the return code tells |
| 987 | * the netfilter core what to do */ |
| 988 | DEBUGP("nf_conntrack_in: Can't track with proto module\n"); |
| 989 | nf_conntrack_put((*pskb)->nfct); |
| 990 | (*pskb)->nfct = NULL; |
| 991 | NF_CT_STAT_INC(invalid); |
| 992 | return -ret; |
| 993 | } |
| 994 | |
| 995 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) |
| 996 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); |
| 997 | |
| 998 | return ret; |
| 999 | } |
| 1000 | |
| 1001 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, |
| 1002 | const struct nf_conntrack_tuple *orig) |
| 1003 | { |
| 1004 | return nf_ct_invert_tuple(inverse, orig, |
| 1005 | nf_ct_find_l3proto(orig->src.l3num), |
| 1006 | nf_ct_find_proto(orig->src.l3num, |
| 1007 | orig->dst.protonum)); |
| 1008 | } |
| 1009 | |
| 1010 | /* Would two expected things clash? */ |
| 1011 | static inline int expect_clash(const struct nf_conntrack_expect *a, |
| 1012 | const struct nf_conntrack_expect *b) |
| 1013 | { |
| 1014 | /* Part covered by intersection of masks must be unequal, |
| 1015 | otherwise they clash */ |
| 1016 | struct nf_conntrack_tuple intersect_mask; |
| 1017 | int count; |
| 1018 | |
| 1019 | intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num; |
| 1020 | intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all; |
| 1021 | intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all; |
| 1022 | intersect_mask.dst.protonum = a->mask.dst.protonum |
| 1023 | & b->mask.dst.protonum; |
| 1024 | |
| 1025 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ |
| 1026 | intersect_mask.src.u3.all[count] = |
| 1027 | a->mask.src.u3.all[count] & b->mask.src.u3.all[count]; |
| 1028 | } |
| 1029 | |
| 1030 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ |
| 1031 | intersect_mask.dst.u3.all[count] = |
| 1032 | a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count]; |
| 1033 | } |
| 1034 | |
| 1035 | return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask); |
| 1036 | } |
| 1037 | |
| 1038 | static inline int expect_matches(const struct nf_conntrack_expect *a, |
| 1039 | const struct nf_conntrack_expect *b) |
| 1040 | { |
| 1041 | return a->master == b->master |
| 1042 | && nf_ct_tuple_equal(&a->tuple, &b->tuple) |
| 1043 | && nf_ct_tuple_equal(&a->mask, &b->mask); |
| 1044 | } |
| 1045 | |
| 1046 | /* Generally a bad idea to call this: could have matched already. */ |
| 1047 | void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp) |
| 1048 | { |
| 1049 | struct nf_conntrack_expect *i; |
| 1050 | |
| 1051 | write_lock_bh(&nf_conntrack_lock); |
| 1052 | /* choose the the oldest expectation to evict */ |
| 1053 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { |
| 1054 | if (expect_matches(i, exp) && del_timer(&i->timeout)) { |
| 1055 | nf_ct_unlink_expect(i); |
| 1056 | write_unlock_bh(&nf_conntrack_lock); |
| 1057 | nf_conntrack_expect_put(i); |
| 1058 | return; |
| 1059 | } |
| 1060 | } |
| 1061 | write_unlock_bh(&nf_conntrack_lock); |
| 1062 | } |
| 1063 | |
| 1064 | /* We don't increase the master conntrack refcount for non-fulfilled |
| 1065 | * conntracks. During the conntrack destruction, the expectations are |
| 1066 | * always killed before the conntrack itself */ |
| 1067 | struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me) |
| 1068 | { |
| 1069 | struct nf_conntrack_expect *new; |
| 1070 | |
| 1071 | new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC); |
| 1072 | if (!new) { |
| 1073 | DEBUGP("expect_related: OOM allocating expect\n"); |
| 1074 | return NULL; |
| 1075 | } |
| 1076 | new->master = me; |
| 1077 | atomic_set(&new->use, 1); |
| 1078 | return new; |
| 1079 | } |
| 1080 | |
| 1081 | void nf_conntrack_expect_put(struct nf_conntrack_expect *exp) |
| 1082 | { |
| 1083 | if (atomic_dec_and_test(&exp->use)) |
| 1084 | kmem_cache_free(nf_conntrack_expect_cachep, exp); |
| 1085 | } |
| 1086 | |
| 1087 | static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp) |
| 1088 | { |
| 1089 | atomic_inc(&exp->use); |
| 1090 | exp->master->expecting++; |
| 1091 | list_add(&exp->list, &nf_conntrack_expect_list); |
| 1092 | |
| 1093 | init_timer(&exp->timeout); |
| 1094 | exp->timeout.data = (unsigned long)exp; |
| 1095 | exp->timeout.function = expectation_timed_out; |
| 1096 | exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ; |
| 1097 | add_timer(&exp->timeout); |
| 1098 | |
| 1099 | atomic_inc(&exp->use); |
| 1100 | NF_CT_STAT_INC(expect_create); |
| 1101 | } |
| 1102 | |
| 1103 | /* Race with expectations being used means we could have none to find; OK. */ |
| 1104 | static void evict_oldest_expect(struct nf_conn *master) |
| 1105 | { |
| 1106 | struct nf_conntrack_expect *i; |
| 1107 | |
| 1108 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { |
| 1109 | if (i->master == master) { |
| 1110 | if (del_timer(&i->timeout)) { |
| 1111 | nf_ct_unlink_expect(i); |
| 1112 | nf_conntrack_expect_put(i); |
| 1113 | } |
| 1114 | break; |
| 1115 | } |
| 1116 | } |
| 1117 | } |
| 1118 | |
| 1119 | static inline int refresh_timer(struct nf_conntrack_expect *i) |
| 1120 | { |
| 1121 | if (!del_timer(&i->timeout)) |
| 1122 | return 0; |
| 1123 | |
| 1124 | i->timeout.expires = jiffies + i->master->helper->timeout*HZ; |
| 1125 | add_timer(&i->timeout); |
| 1126 | return 1; |
| 1127 | } |
| 1128 | |
| 1129 | int nf_conntrack_expect_related(struct nf_conntrack_expect *expect) |
| 1130 | { |
| 1131 | struct nf_conntrack_expect *i; |
| 1132 | int ret; |
| 1133 | |
| 1134 | DEBUGP("nf_conntrack_expect_related %p\n", related_to); |
| 1135 | DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple); |
| 1136 | DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask); |
| 1137 | |
| 1138 | write_lock_bh(&nf_conntrack_lock); |
| 1139 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { |
| 1140 | if (expect_matches(i, expect)) { |
| 1141 | /* Refresh timer: if it's dying, ignore.. */ |
| 1142 | if (refresh_timer(i)) { |
| 1143 | ret = 0; |
| 1144 | goto out; |
| 1145 | } |
| 1146 | } else if (expect_clash(i, expect)) { |
| 1147 | ret = -EBUSY; |
| 1148 | goto out; |
| 1149 | } |
| 1150 | } |
| 1151 | /* Will be over limit? */ |
| 1152 | if (expect->master->helper->max_expected && |
| 1153 | expect->master->expecting >= expect->master->helper->max_expected) |
| 1154 | evict_oldest_expect(expect->master); |
| 1155 | |
| 1156 | nf_conntrack_expect_insert(expect); |
| 1157 | nf_conntrack_expect_event(IPEXP_NEW, expect); |
| 1158 | ret = 0; |
| 1159 | out: |
| 1160 | write_unlock_bh(&nf_conntrack_lock); |
| 1161 | return ret; |
| 1162 | } |
| 1163 | |
| 1164 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is |
| 1165 | implicitly racy: see __nf_conntrack_confirm */ |
| 1166 | void nf_conntrack_alter_reply(struct nf_conn *conntrack, |
| 1167 | const struct nf_conntrack_tuple *newreply) |
| 1168 | { |
| 1169 | write_lock_bh(&nf_conntrack_lock); |
| 1170 | /* Should be unconfirmed, so not in hash table yet */ |
| 1171 | NF_CT_ASSERT(!nf_ct_is_confirmed(conntrack)); |
| 1172 | |
| 1173 | DEBUGP("Altering reply tuple of %p to ", conntrack); |
| 1174 | NF_CT_DUMP_TUPLE(newreply); |
| 1175 | |
| 1176 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; |
| 1177 | if (!conntrack->master && conntrack->expecting == 0) |
| 1178 | conntrack->helper = nf_ct_find_helper(newreply); |
| 1179 | write_unlock_bh(&nf_conntrack_lock); |
| 1180 | } |
| 1181 | |
| 1182 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
| 1183 | { |
| 1184 | int ret; |
| 1185 | BUG_ON(me->timeout == 0); |
| 1186 | |
| 1187 | ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help", |
| 1188 | sizeof(struct nf_conn) |
| 1189 | + sizeof(union nf_conntrack_help) |
| 1190 | + __alignof__(union nf_conntrack_help), |
| 1191 | init_conntrack_for_helper); |
| 1192 | if (ret < 0) { |
| 1193 | printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n"); |
| 1194 | return ret; |
| 1195 | } |
| 1196 | write_lock_bh(&nf_conntrack_lock); |
| 1197 | list_prepend(&helpers, me); |
| 1198 | write_unlock_bh(&nf_conntrack_lock); |
| 1199 | |
| 1200 | return 0; |
| 1201 | } |
| 1202 | |
| 1203 | static inline int unhelp(struct nf_conntrack_tuple_hash *i, |
| 1204 | const struct nf_conntrack_helper *me) |
| 1205 | { |
| 1206 | if (nf_ct_tuplehash_to_ctrack(i)->helper == me) { |
| 1207 | nf_conntrack_event(IPCT_HELPER, nf_ct_tuplehash_to_ctrack(i)); |
| 1208 | nf_ct_tuplehash_to_ctrack(i)->helper = NULL; |
| 1209 | } |
| 1210 | return 0; |
| 1211 | } |
| 1212 | |
| 1213 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) |
| 1214 | { |
| 1215 | unsigned int i; |
| 1216 | struct nf_conntrack_expect *exp, *tmp; |
| 1217 | |
| 1218 | /* Need write lock here, to delete helper. */ |
| 1219 | write_lock_bh(&nf_conntrack_lock); |
| 1220 | LIST_DELETE(&helpers, me); |
| 1221 | |
| 1222 | /* Get rid of expectations */ |
| 1223 | list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) { |
| 1224 | if (exp->master->helper == me && del_timer(&exp->timeout)) { |
| 1225 | nf_ct_unlink_expect(exp); |
| 1226 | nf_conntrack_expect_put(exp); |
| 1227 | } |
| 1228 | } |
| 1229 | |
| 1230 | /* Get rid of expecteds, set helpers to NULL. */ |
| 1231 | LIST_FIND_W(&unconfirmed, unhelp, struct nf_conntrack_tuple_hash*, me); |
| 1232 | for (i = 0; i < nf_conntrack_htable_size; i++) |
| 1233 | LIST_FIND_W(&nf_conntrack_hash[i], unhelp, |
| 1234 | struct nf_conntrack_tuple_hash *, me); |
| 1235 | write_unlock_bh(&nf_conntrack_lock); |
| 1236 | |
| 1237 | /* Someone could be still looking at the helper in a bh. */ |
| 1238 | synchronize_net(); |
| 1239 | } |
| 1240 | |
| 1241 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ |
| 1242 | void __nf_ct_refresh_acct(struct nf_conn *ct, |
| 1243 | enum ip_conntrack_info ctinfo, |
| 1244 | const struct sk_buff *skb, |
| 1245 | unsigned long extra_jiffies, |
| 1246 | int do_acct) |
| 1247 | { |
| 1248 | int event = 0; |
| 1249 | |
| 1250 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); |
| 1251 | NF_CT_ASSERT(skb); |
| 1252 | |
| 1253 | write_lock_bh(&nf_conntrack_lock); |
| 1254 | |
| 1255 | /* If not in hash table, timer will not be active yet */ |
| 1256 | if (!nf_ct_is_confirmed(ct)) { |
| 1257 | ct->timeout.expires = extra_jiffies; |
| 1258 | event = IPCT_REFRESH; |
| 1259 | } else { |
| 1260 | /* Need del_timer for race avoidance (may already be dying). */ |
| 1261 | if (del_timer(&ct->timeout)) { |
| 1262 | ct->timeout.expires = jiffies + extra_jiffies; |
| 1263 | add_timer(&ct->timeout); |
| 1264 | event = IPCT_REFRESH; |
| 1265 | } |
| 1266 | } |
| 1267 | |
| 1268 | #ifdef CONFIG_NF_CT_ACCT |
| 1269 | if (do_acct) { |
| 1270 | ct->counters[CTINFO2DIR(ctinfo)].packets++; |
| 1271 | ct->counters[CTINFO2DIR(ctinfo)].bytes += |
| 1272 | skb->len - (unsigned int)(skb->nh.raw - skb->data); |
| 1273 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) |
| 1274 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) |
| 1275 | event |= IPCT_COUNTER_FILLING; |
| 1276 | } |
| 1277 | #endif |
| 1278 | |
| 1279 | write_unlock_bh(&nf_conntrack_lock); |
| 1280 | |
| 1281 | /* must be unlocked when calling event cache */ |
| 1282 | if (event) |
| 1283 | nf_conntrack_event_cache(event, skb); |
| 1284 | } |
| 1285 | |
| 1286 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
| 1287 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) |
| 1288 | { |
| 1289 | struct nf_conn *ct; |
| 1290 | enum ip_conntrack_info ctinfo; |
| 1291 | |
| 1292 | /* This ICMP is in reverse direction to the packet which caused it */ |
| 1293 | ct = nf_ct_get(skb, &ctinfo); |
| 1294 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) |
| 1295 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; |
| 1296 | else |
| 1297 | ctinfo = IP_CT_RELATED; |
| 1298 | |
| 1299 | /* Attach to new skbuff, and increment count */ |
| 1300 | nskb->nfct = &ct->ct_general; |
| 1301 | nskb->nfctinfo = ctinfo; |
| 1302 | nf_conntrack_get(nskb->nfct); |
| 1303 | } |
| 1304 | |
| 1305 | static inline int |
| 1306 | do_iter(const struct nf_conntrack_tuple_hash *i, |
| 1307 | int (*iter)(struct nf_conn *i, void *data), |
| 1308 | void *data) |
| 1309 | { |
| 1310 | return iter(nf_ct_tuplehash_to_ctrack(i), data); |
| 1311 | } |
| 1312 | |
| 1313 | /* Bring out ya dead! */ |
| 1314 | static struct nf_conntrack_tuple_hash * |
| 1315 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), |
| 1316 | void *data, unsigned int *bucket) |
| 1317 | { |
| 1318 | struct nf_conntrack_tuple_hash *h = NULL; |
| 1319 | |
| 1320 | write_lock_bh(&nf_conntrack_lock); |
| 1321 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { |
| 1322 | h = LIST_FIND_W(&nf_conntrack_hash[*bucket], do_iter, |
| 1323 | struct nf_conntrack_tuple_hash *, iter, data); |
| 1324 | if (h) |
| 1325 | break; |
| 1326 | } |
| 1327 | if (!h) |
| 1328 | h = LIST_FIND_W(&unconfirmed, do_iter, |
| 1329 | struct nf_conntrack_tuple_hash *, iter, data); |
| 1330 | if (h) |
| 1331 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); |
| 1332 | write_unlock_bh(&nf_conntrack_lock); |
| 1333 | |
| 1334 | return h; |
| 1335 | } |
| 1336 | |
| 1337 | void |
| 1338 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) |
| 1339 | { |
| 1340 | struct nf_conntrack_tuple_hash *h; |
| 1341 | unsigned int bucket = 0; |
| 1342 | |
| 1343 | while ((h = get_next_corpse(iter, data, &bucket)) != NULL) { |
| 1344 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); |
| 1345 | /* Time to push up daises... */ |
| 1346 | if (del_timer(&ct->timeout)) |
| 1347 | death_by_timeout((unsigned long)ct); |
| 1348 | /* ... else the timer will get him soon. */ |
| 1349 | |
| 1350 | nf_ct_put(ct); |
| 1351 | } |
| 1352 | } |
| 1353 | |
| 1354 | static int kill_all(struct nf_conn *i, void *data) |
| 1355 | { |
| 1356 | return 1; |
| 1357 | } |
| 1358 | |
| 1359 | static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) |
| 1360 | { |
| 1361 | if (vmalloced) |
| 1362 | vfree(hash); |
| 1363 | else |
| 1364 | free_pages((unsigned long)hash, |
| 1365 | get_order(sizeof(struct list_head) * size)); |
| 1366 | } |
| 1367 | |
| 1368 | /* Mishearing the voices in his head, our hero wonders how he's |
| 1369 | supposed to kill the mall. */ |
| 1370 | void nf_conntrack_cleanup(void) |
| 1371 | { |
| 1372 | int i; |
| 1373 | |
| 1374 | /* This makes sure all current packets have passed through |
| 1375 | netfilter framework. Roll on, two-stage module |
| 1376 | delete... */ |
| 1377 | synchronize_net(); |
| 1378 | |
| 1379 | nf_ct_event_cache_flush(); |
| 1380 | i_see_dead_people: |
| 1381 | nf_ct_iterate_cleanup(kill_all, NULL); |
| 1382 | if (atomic_read(&nf_conntrack_count) != 0) { |
| 1383 | schedule(); |
| 1384 | goto i_see_dead_people; |
| 1385 | } |
Patrick McHardy | 6636568 | 2005-12-05 13:36:50 -0800 | [diff] [blame^] | 1386 | /* wait until all references to nf_conntrack_untracked are dropped */ |
| 1387 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) |
| 1388 | schedule(); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 1389 | |
| 1390 | for (i = 0; i < NF_CT_F_NUM; i++) { |
| 1391 | if (nf_ct_cache[i].use == 0) |
| 1392 | continue; |
| 1393 | |
| 1394 | NF_CT_ASSERT(nf_ct_cache[i].use == 1); |
| 1395 | nf_ct_cache[i].use = 1; |
| 1396 | nf_conntrack_unregister_cache(i); |
| 1397 | } |
| 1398 | kmem_cache_destroy(nf_conntrack_expect_cachep); |
| 1399 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, |
| 1400 | nf_conntrack_htable_size); |
KOVACS Krisztian | 5a6f294 | 2005-11-15 16:47:34 -0800 | [diff] [blame] | 1401 | |
| 1402 | /* free l3proto protocol tables */ |
| 1403 | for (i = 0; i < PF_MAX; i++) |
| 1404 | if (nf_ct_protos[i]) { |
| 1405 | kfree(nf_ct_protos[i]); |
| 1406 | nf_ct_protos[i] = NULL; |
| 1407 | } |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 1408 | } |
| 1409 | |
| 1410 | static struct list_head *alloc_hashtable(int size, int *vmalloced) |
| 1411 | { |
| 1412 | struct list_head *hash; |
| 1413 | unsigned int i; |
| 1414 | |
| 1415 | *vmalloced = 0; |
| 1416 | hash = (void*)__get_free_pages(GFP_KERNEL, |
| 1417 | get_order(sizeof(struct list_head) |
| 1418 | * size)); |
| 1419 | if (!hash) { |
| 1420 | *vmalloced = 1; |
| 1421 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); |
| 1422 | hash = vmalloc(sizeof(struct list_head) * size); |
| 1423 | } |
| 1424 | |
| 1425 | if (hash) |
| 1426 | for (i = 0; i < size; i++) |
| 1427 | INIT_LIST_HEAD(&hash[i]); |
| 1428 | |
| 1429 | return hash; |
| 1430 | } |
| 1431 | |
| 1432 | int set_hashsize(const char *val, struct kernel_param *kp) |
| 1433 | { |
| 1434 | int i, bucket, hashsize, vmalloced; |
| 1435 | int old_vmalloced, old_size; |
| 1436 | int rnd; |
| 1437 | struct list_head *hash, *old_hash; |
| 1438 | struct nf_conntrack_tuple_hash *h; |
| 1439 | |
| 1440 | /* On boot, we can set this without any fancy locking. */ |
| 1441 | if (!nf_conntrack_htable_size) |
| 1442 | return param_set_uint(val, kp); |
| 1443 | |
| 1444 | hashsize = simple_strtol(val, NULL, 0); |
| 1445 | if (!hashsize) |
| 1446 | return -EINVAL; |
| 1447 | |
| 1448 | hash = alloc_hashtable(hashsize, &vmalloced); |
| 1449 | if (!hash) |
| 1450 | return -ENOMEM; |
| 1451 | |
| 1452 | /* We have to rehahs for the new table anyway, so we also can |
| 1453 | * use a newrandom seed */ |
| 1454 | get_random_bytes(&rnd, 4); |
| 1455 | |
| 1456 | write_lock_bh(&nf_conntrack_lock); |
| 1457 | for (i = 0; i < nf_conntrack_htable_size; i++) { |
| 1458 | while (!list_empty(&nf_conntrack_hash[i])) { |
| 1459 | h = list_entry(nf_conntrack_hash[i].next, |
| 1460 | struct nf_conntrack_tuple_hash, list); |
| 1461 | list_del(&h->list); |
| 1462 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); |
| 1463 | list_add_tail(&h->list, &hash[bucket]); |
| 1464 | } |
| 1465 | } |
| 1466 | old_size = nf_conntrack_htable_size; |
| 1467 | old_vmalloced = nf_conntrack_vmalloc; |
| 1468 | old_hash = nf_conntrack_hash; |
| 1469 | |
| 1470 | nf_conntrack_htable_size = hashsize; |
| 1471 | nf_conntrack_vmalloc = vmalloced; |
| 1472 | nf_conntrack_hash = hash; |
| 1473 | nf_conntrack_hash_rnd = rnd; |
| 1474 | write_unlock_bh(&nf_conntrack_lock); |
| 1475 | |
| 1476 | free_conntrack_hash(old_hash, old_vmalloced, old_size); |
| 1477 | return 0; |
| 1478 | } |
| 1479 | |
| 1480 | module_param_call(hashsize, set_hashsize, param_get_uint, |
| 1481 | &nf_conntrack_htable_size, 0600); |
| 1482 | |
| 1483 | int __init nf_conntrack_init(void) |
| 1484 | { |
| 1485 | unsigned int i; |
| 1486 | int ret; |
| 1487 | |
| 1488 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB |
| 1489 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ |
| 1490 | if (!nf_conntrack_htable_size) { |
| 1491 | nf_conntrack_htable_size |
| 1492 | = (((num_physpages << PAGE_SHIFT) / 16384) |
| 1493 | / sizeof(struct list_head)); |
| 1494 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) |
| 1495 | nf_conntrack_htable_size = 8192; |
| 1496 | if (nf_conntrack_htable_size < 16) |
| 1497 | nf_conntrack_htable_size = 16; |
| 1498 | } |
| 1499 | nf_conntrack_max = 8 * nf_conntrack_htable_size; |
| 1500 | |
| 1501 | printk("nf_conntrack version %s (%u buckets, %d max)\n", |
| 1502 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, |
| 1503 | nf_conntrack_max); |
| 1504 | |
| 1505 | nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, |
| 1506 | &nf_conntrack_vmalloc); |
| 1507 | if (!nf_conntrack_hash) { |
| 1508 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); |
| 1509 | goto err_out; |
| 1510 | } |
| 1511 | |
| 1512 | ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", |
| 1513 | sizeof(struct nf_conn), NULL); |
| 1514 | if (ret < 0) { |
| 1515 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); |
| 1516 | goto err_free_hash; |
| 1517 | } |
| 1518 | |
| 1519 | nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", |
| 1520 | sizeof(struct nf_conntrack_expect), |
| 1521 | 0, 0, NULL, NULL); |
| 1522 | if (!nf_conntrack_expect_cachep) { |
| 1523 | printk(KERN_ERR "Unable to create nf_expect slab cache\n"); |
| 1524 | goto err_free_conntrack_slab; |
| 1525 | } |
| 1526 | |
| 1527 | /* Don't NEED lock here, but good form anyway. */ |
| 1528 | write_lock_bh(&nf_conntrack_lock); |
| 1529 | for (i = 0; i < PF_MAX; i++) |
| 1530 | nf_ct_l3protos[i] = &nf_conntrack_generic_l3proto; |
| 1531 | write_unlock_bh(&nf_conntrack_lock); |
| 1532 | |
| 1533 | /* Set up fake conntrack: |
| 1534 | - to never be deleted, not in any hashes */ |
| 1535 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); |
| 1536 | /* - and look it like as a confirmed connection */ |
| 1537 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); |
| 1538 | |
| 1539 | return ret; |
| 1540 | |
| 1541 | err_free_conntrack_slab: |
| 1542 | nf_conntrack_unregister_cache(NF_CT_F_BASIC); |
| 1543 | err_free_hash: |
| 1544 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, |
| 1545 | nf_conntrack_htable_size); |
| 1546 | err_out: |
| 1547 | return -ENOMEM; |
| 1548 | } |