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
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>
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.
13 * 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
14 * - new API and handling of conntrack/nat helpers
15 * - now capable of multiple expectations for one master
16 * 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
17 * - add usage/reference counts to ip_conntrack_expect
18 * - export ip_conntrack[_expect]_{find_get,put} functions
19 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
20 * - generalize L3 protocol denendent part.
21 * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
22 * - add support various size of conntrack structures.
23 * 26 Jan 2006: Harald Welte <laforge@netfilter.org>
24 * - restructure nf_conn (introduce nf_conn_help)
25 * - redesign 'features' how they were originally intended
26 * 26 Feb 2006: Pablo Neira Ayuso <pablo@eurodev.net>
27 * - add support for L3 protocol module load on demand.
29 * Derived from net/ipv4/netfilter/ip_conntrack_core.c
32 #include <linux/types.h>
33 #include <linux/netfilter.h>
34 #include <linux/module.h>
35 #include <linux/skbuff.h>
36 #include <linux/proc_fs.h>
37 #include <linux/vmalloc.h>
38 #include <linux/stddef.h>
39 #include <linux/slab.h>
40 #include <linux/random.h>
41 #include <linux/jhash.h>
42 #include <linux/err.h>
43 #include <linux/percpu.h>
44 #include <linux/moduleparam.h>
45 #include <linux/notifier.h>
46 #include <linux/kernel.h>
47 #include <linux/netdevice.h>
48 #include <linux/socket.h>
51 #include <net/netfilter/nf_conntrack.h>
52 #include <net/netfilter/nf_conntrack_l3proto.h>
53 #include <net/netfilter/nf_conntrack_l4proto.h>
54 #include <net/netfilter/nf_conntrack_expect.h>
55 #include <net/netfilter/nf_conntrack_helper.h>
56 #include <net/netfilter/nf_conntrack_core.h>
58 #define NF_CONNTRACK_VERSION "0.5.0"
63 #define DEBUGP(format, args...)
66 DEFINE_RWLOCK(nf_conntrack_lock
);
67 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
69 /* nf_conntrack_standalone needs this */
70 atomic_t nf_conntrack_count
= ATOMIC_INIT(0);
71 EXPORT_SYMBOL_GPL(nf_conntrack_count
);
73 void (*nf_conntrack_destroyed
)(struct nf_conn
*conntrack
);
74 EXPORT_SYMBOL_GPL(nf_conntrack_destroyed
);
76 unsigned int nf_conntrack_htable_size __read_mostly
;
77 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
79 int nf_conntrack_max __read_mostly
;
80 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
82 struct list_head
*nf_conntrack_hash __read_mostly
;
83 EXPORT_SYMBOL_GPL(nf_conntrack_hash
);
85 struct nf_conn nf_conntrack_untracked __read_mostly
;
86 EXPORT_SYMBOL_GPL(nf_conntrack_untracked
);
88 unsigned int nf_ct_log_invalid __read_mostly
;
89 LIST_HEAD(unconfirmed
);
90 static int nf_conntrack_vmalloc __read_mostly
;
92 static unsigned int nf_conntrack_next_id
;
94 DEFINE_PER_CPU(struct ip_conntrack_stat
, nf_conntrack_stat
);
95 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat
);
98 * This scheme offers various size of "struct nf_conn" dependent on
99 * features(helper, nat, ...)
102 #define NF_CT_FEATURES_NAMELEN 256
104 /* name of slab cache. printed in /proc/slabinfo */
107 /* size of slab cache */
110 /* slab cache pointer */
111 struct kmem_cache
*cachep
;
113 /* allocated slab cache + modules which uses this slab cache */
116 } nf_ct_cache
[NF_CT_F_NUM
];
118 /* protect members of nf_ct_cache except of "use" */
119 DEFINE_RWLOCK(nf_ct_cache_lock
);
121 /* This avoids calling kmem_cache_create() with same name simultaneously */
122 static DEFINE_MUTEX(nf_ct_cache_mutex
);
124 static int nf_conntrack_hash_rnd_initted
;
125 static unsigned int nf_conntrack_hash_rnd
;
127 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
128 unsigned int size
, unsigned int rnd
)
131 a
= jhash((void *)tuple
->src
.u3
.all
, sizeof(tuple
->src
.u3
.all
),
132 ((tuple
->src
.l3num
) << 16) | tuple
->dst
.protonum
);
133 b
= jhash((void *)tuple
->dst
.u3
.all
, sizeof(tuple
->dst
.u3
.all
),
134 (tuple
->src
.u
.all
<< 16) | tuple
->dst
.u
.all
);
136 return jhash_2words(a
, b
, rnd
) % size
;
139 static inline u_int32_t
hash_conntrack(const struct nf_conntrack_tuple
*tuple
)
141 return __hash_conntrack(tuple
, nf_conntrack_htable_size
,
142 nf_conntrack_hash_rnd
);
145 int nf_conntrack_register_cache(u_int32_t features
, const char *name
,
150 struct kmem_cache
*cachep
;
152 DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n",
153 features
, name
, size
);
155 if (features
< NF_CT_F_BASIC
|| features
>= NF_CT_F_NUM
) {
156 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n",
161 mutex_lock(&nf_ct_cache_mutex
);
163 write_lock_bh(&nf_ct_cache_lock
);
164 /* e.g: multiple helpers are loaded */
165 if (nf_ct_cache
[features
].use
> 0) {
166 DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
167 if ((!strncmp(nf_ct_cache
[features
].name
, name
,
168 NF_CT_FEATURES_NAMELEN
))
169 && nf_ct_cache
[features
].size
== size
) {
170 DEBUGP("nf_conntrack_register_cache: reusing.\n");
171 nf_ct_cache
[features
].use
++;
176 write_unlock_bh(&nf_ct_cache_lock
);
177 mutex_unlock(&nf_ct_cache_mutex
);
180 write_unlock_bh(&nf_ct_cache_lock
);
183 * The memory space for name of slab cache must be alive until
184 * cache is destroyed.
186 cache_name
= kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN
, GFP_ATOMIC
);
187 if (cache_name
== NULL
) {
188 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n");
193 if (strlcpy(cache_name
, name
, NF_CT_FEATURES_NAMELEN
)
194 >= NF_CT_FEATURES_NAMELEN
) {
195 printk("nf_conntrack_register_cache: name too long\n");
200 cachep
= kmem_cache_create(cache_name
, size
, 0, 0,
203 printk("nf_conntrack_register_cache: Can't create slab cache "
204 "for the features = 0x%x\n", features
);
209 write_lock_bh(&nf_ct_cache_lock
);
210 nf_ct_cache
[features
].use
= 1;
211 nf_ct_cache
[features
].size
= size
;
212 nf_ct_cache
[features
].cachep
= cachep
;
213 nf_ct_cache
[features
].name
= cache_name
;
214 write_unlock_bh(&nf_ct_cache_lock
);
221 mutex_unlock(&nf_ct_cache_mutex
);
224 EXPORT_SYMBOL_GPL(nf_conntrack_register_cache
);
226 /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */
227 void nf_conntrack_unregister_cache(u_int32_t features
)
229 struct kmem_cache
*cachep
;
233 * This assures that kmem_cache_create() isn't called before destroying
236 DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features
);
237 mutex_lock(&nf_ct_cache_mutex
);
239 write_lock_bh(&nf_ct_cache_lock
);
240 if (--nf_ct_cache
[features
].use
> 0) {
241 write_unlock_bh(&nf_ct_cache_lock
);
242 mutex_unlock(&nf_ct_cache_mutex
);
245 cachep
= nf_ct_cache
[features
].cachep
;
246 name
= nf_ct_cache
[features
].name
;
247 nf_ct_cache
[features
].cachep
= NULL
;
248 nf_ct_cache
[features
].name
= NULL
;
249 nf_ct_cache
[features
].size
= 0;
250 write_unlock_bh(&nf_ct_cache_lock
);
254 kmem_cache_destroy(cachep
);
257 mutex_unlock(&nf_ct_cache_mutex
);
259 EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache
);
262 nf_ct_get_tuple(const struct sk_buff
*skb
,
264 unsigned int dataoff
,
267 struct nf_conntrack_tuple
*tuple
,
268 const struct nf_conntrack_l3proto
*l3proto
,
269 const struct nf_conntrack_l4proto
*l4proto
)
271 NF_CT_TUPLE_U_BLANK(tuple
);
273 tuple
->src
.l3num
= l3num
;
274 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
277 tuple
->dst
.protonum
= protonum
;
278 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
280 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
282 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
285 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
286 const struct nf_conntrack_tuple
*orig
,
287 const struct nf_conntrack_l3proto
*l3proto
,
288 const struct nf_conntrack_l4proto
*l4proto
)
290 NF_CT_TUPLE_U_BLANK(inverse
);
292 inverse
->src
.l3num
= orig
->src
.l3num
;
293 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
296 inverse
->dst
.dir
= !orig
->dst
.dir
;
298 inverse
->dst
.protonum
= orig
->dst
.protonum
;
299 return l4proto
->invert_tuple(inverse
, orig
);
301 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
304 clean_from_lists(struct nf_conn
*ct
)
306 DEBUGP("clean_from_lists(%p)\n", ct
);
307 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
308 list_del(&ct
->tuplehash
[IP_CT_DIR_REPLY
].list
);
310 /* Destroy all pending expectations */
311 nf_ct_remove_expectations(ct
);
315 destroy_conntrack(struct nf_conntrack
*nfct
)
317 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
318 struct nf_conn_help
*help
= nfct_help(ct
);
319 struct nf_conntrack_l3proto
*l3proto
;
320 struct nf_conntrack_l4proto
*l4proto
;
321 typeof(nf_conntrack_destroyed
) destroyed
;
323 DEBUGP("destroy_conntrack(%p)\n", ct
);
324 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
325 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
327 nf_conntrack_event(IPCT_DESTROY
, ct
);
328 set_bit(IPS_DYING_BIT
, &ct
->status
);
330 if (help
&& help
->helper
&& help
->helper
->destroy
)
331 help
->helper
->destroy(ct
);
333 /* To make sure we don't get any weird locking issues here:
334 * destroy_conntrack() MUST NOT be called with a write lock
335 * to nf_conntrack_lock!!! -HW */
337 l3proto
= __nf_ct_l3proto_find(ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.l3num
);
338 if (l3proto
&& l3proto
->destroy
)
339 l3proto
->destroy(ct
);
341 l4proto
= __nf_ct_l4proto_find(ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.l3num
,
342 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.dst
.protonum
);
343 if (l4proto
&& l4proto
->destroy
)
344 l4proto
->destroy(ct
);
346 destroyed
= rcu_dereference(nf_conntrack_destroyed
);
352 write_lock_bh(&nf_conntrack_lock
);
353 /* Expectations will have been removed in clean_from_lists,
354 * except TFTP can create an expectation on the first packet,
355 * before connection is in the list, so we need to clean here,
357 nf_ct_remove_expectations(ct
);
359 /* We overload first tuple to link into unconfirmed list. */
360 if (!nf_ct_is_confirmed(ct
)) {
361 BUG_ON(list_empty(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
));
362 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
365 NF_CT_STAT_INC(delete);
366 write_unlock_bh(&nf_conntrack_lock
);
369 nf_ct_put(ct
->master
);
371 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct
);
372 nf_conntrack_free(ct
);
375 static void death_by_timeout(unsigned long ul_conntrack
)
377 struct nf_conn
*ct
= (void *)ul_conntrack
;
379 write_lock_bh(&nf_conntrack_lock
);
380 /* Inside lock so preempt is disabled on module removal path.
381 * Otherwise we can get spurious warnings. */
382 NF_CT_STAT_INC(delete_list
);
383 clean_from_lists(ct
);
384 write_unlock_bh(&nf_conntrack_lock
);
388 struct nf_conntrack_tuple_hash
*
389 __nf_conntrack_find(const struct nf_conntrack_tuple
*tuple
,
390 const struct nf_conn
*ignored_conntrack
)
392 struct nf_conntrack_tuple_hash
*h
;
393 unsigned int hash
= hash_conntrack(tuple
);
395 list_for_each_entry(h
, &nf_conntrack_hash
[hash
], list
) {
396 if (nf_ct_tuplehash_to_ctrack(h
) != ignored_conntrack
&&
397 nf_ct_tuple_equal(tuple
, &h
->tuple
)) {
398 NF_CT_STAT_INC(found
);
401 NF_CT_STAT_INC(searched
);
406 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
408 /* Find a connection corresponding to a tuple. */
409 struct nf_conntrack_tuple_hash
*
410 nf_conntrack_find_get(const struct nf_conntrack_tuple
*tuple
,
411 const struct nf_conn
*ignored_conntrack
)
413 struct nf_conntrack_tuple_hash
*h
;
415 read_lock_bh(&nf_conntrack_lock
);
416 h
= __nf_conntrack_find(tuple
, ignored_conntrack
);
418 atomic_inc(&nf_ct_tuplehash_to_ctrack(h
)->ct_general
.use
);
419 read_unlock_bh(&nf_conntrack_lock
);
423 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
425 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
427 unsigned int repl_hash
)
429 ct
->id
= ++nf_conntrack_next_id
;
430 list_add(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
,
431 &nf_conntrack_hash
[hash
]);
432 list_add(&ct
->tuplehash
[IP_CT_DIR_REPLY
].list
,
433 &nf_conntrack_hash
[repl_hash
]);
436 void nf_conntrack_hash_insert(struct nf_conn
*ct
)
438 unsigned int hash
, repl_hash
;
440 hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
441 repl_hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
443 write_lock_bh(&nf_conntrack_lock
);
444 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
445 write_unlock_bh(&nf_conntrack_lock
);
447 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert
);
449 /* Confirm a connection given skb; places it in hash table */
451 __nf_conntrack_confirm(struct sk_buff
**pskb
)
453 unsigned int hash
, repl_hash
;
454 struct nf_conntrack_tuple_hash
*h
;
456 struct nf_conn_help
*help
;
457 enum ip_conntrack_info ctinfo
;
459 ct
= nf_ct_get(*pskb
, &ctinfo
);
461 /* ipt_REJECT uses nf_conntrack_attach to attach related
462 ICMP/TCP RST packets in other direction. Actual packet
463 which created connection will be IP_CT_NEW or for an
464 expected connection, IP_CT_RELATED. */
465 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
468 hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
469 repl_hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
471 /* We're not in hash table, and we refuse to set up related
472 connections for unconfirmed conns. But packet copies and
473 REJECT will give spurious warnings here. */
474 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
476 /* No external references means noone else could have
478 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
479 DEBUGP("Confirming conntrack %p\n", ct
);
481 write_lock_bh(&nf_conntrack_lock
);
483 /* See if there's one in the list already, including reverse:
484 NAT could have grabbed it without realizing, since we're
485 not in the hash. If there is, we lost race. */
486 list_for_each_entry(h
, &nf_conntrack_hash
[hash
], list
)
487 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
490 list_for_each_entry(h
, &nf_conntrack_hash
[repl_hash
], list
)
491 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
495 /* Remove from unconfirmed list */
496 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
498 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
499 /* Timer relative to confirmation time, not original
500 setting time, otherwise we'd get timer wrap in
501 weird delay cases. */
502 ct
->timeout
.expires
+= jiffies
;
503 add_timer(&ct
->timeout
);
504 atomic_inc(&ct
->ct_general
.use
);
505 set_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
506 NF_CT_STAT_INC(insert
);
507 write_unlock_bh(&nf_conntrack_lock
);
508 help
= nfct_help(ct
);
509 if (help
&& help
->helper
)
510 nf_conntrack_event_cache(IPCT_HELPER
, *pskb
);
511 #ifdef CONFIG_NF_NAT_NEEDED
512 if (test_bit(IPS_SRC_NAT_DONE_BIT
, &ct
->status
) ||
513 test_bit(IPS_DST_NAT_DONE_BIT
, &ct
->status
))
514 nf_conntrack_event_cache(IPCT_NATINFO
, *pskb
);
516 nf_conntrack_event_cache(master_ct(ct
) ?
517 IPCT_RELATED
: IPCT_NEW
, *pskb
);
521 NF_CT_STAT_INC(insert_failed
);
522 write_unlock_bh(&nf_conntrack_lock
);
525 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
527 /* Returns true if a connection correspondings to the tuple (required
530 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
531 const struct nf_conn
*ignored_conntrack
)
533 struct nf_conntrack_tuple_hash
*h
;
535 read_lock_bh(&nf_conntrack_lock
);
536 h
= __nf_conntrack_find(tuple
, ignored_conntrack
);
537 read_unlock_bh(&nf_conntrack_lock
);
541 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
543 /* There's a small race here where we may free a just-assured
544 connection. Too bad: we're in trouble anyway. */
545 static int early_drop(struct list_head
*chain
)
547 /* Traverse backwards: gives us oldest, which is roughly LRU */
548 struct nf_conntrack_tuple_hash
*h
;
549 struct nf_conn
*ct
= NULL
, *tmp
;
552 read_lock_bh(&nf_conntrack_lock
);
553 list_for_each_entry_reverse(h
, chain
, list
) {
554 tmp
= nf_ct_tuplehash_to_ctrack(h
);
555 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
)) {
557 atomic_inc(&ct
->ct_general
.use
);
561 read_unlock_bh(&nf_conntrack_lock
);
566 if (del_timer(&ct
->timeout
)) {
567 death_by_timeout((unsigned long)ct
);
569 NF_CT_STAT_INC_ATOMIC(early_drop
);
575 static struct nf_conn
*
576 __nf_conntrack_alloc(const struct nf_conntrack_tuple
*orig
,
577 const struct nf_conntrack_tuple
*repl
,
578 const struct nf_conntrack_l3proto
*l3proto
,
581 struct nf_conn
*conntrack
= NULL
;
582 struct nf_conntrack_helper
*helper
;
584 if (unlikely(!nf_conntrack_hash_rnd_initted
)) {
585 get_random_bytes(&nf_conntrack_hash_rnd
, 4);
586 nf_conntrack_hash_rnd_initted
= 1;
589 /* We don't want any race condition at early drop stage */
590 atomic_inc(&nf_conntrack_count
);
593 && atomic_read(&nf_conntrack_count
) > nf_conntrack_max
) {
594 unsigned int hash
= hash_conntrack(orig
);
595 /* Try dropping from this hash chain. */
596 if (!early_drop(&nf_conntrack_hash
[hash
])) {
597 atomic_dec(&nf_conntrack_count
);
600 "nf_conntrack: table full, dropping"
602 return ERR_PTR(-ENOMEM
);
606 /* find features needed by this conntrack. */
607 features
|= l3proto
->get_features(orig
);
609 /* FIXME: protect helper list per RCU */
610 read_lock_bh(&nf_conntrack_lock
);
611 helper
= __nf_ct_helper_find(repl
);
612 /* NAT might want to assign a helper later */
613 if (helper
|| features
& NF_CT_F_NAT
)
614 features
|= NF_CT_F_HELP
;
615 read_unlock_bh(&nf_conntrack_lock
);
617 DEBUGP("nf_conntrack_alloc: features=0x%x\n", features
);
619 read_lock_bh(&nf_ct_cache_lock
);
621 if (unlikely(!nf_ct_cache
[features
].use
)) {
622 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
627 conntrack
= kmem_cache_alloc(nf_ct_cache
[features
].cachep
, GFP_ATOMIC
);
628 if (conntrack
== NULL
) {
629 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n");
633 memset(conntrack
, 0, nf_ct_cache
[features
].size
);
634 conntrack
->features
= features
;
635 atomic_set(&conntrack
->ct_general
.use
, 1);
636 conntrack
->ct_general
.destroy
= destroy_conntrack
;
637 conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
638 conntrack
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
639 /* Don't set timer yet: wait for confirmation */
640 init_timer(&conntrack
->timeout
);
641 conntrack
->timeout
.data
= (unsigned long)conntrack
;
642 conntrack
->timeout
.function
= death_by_timeout
;
643 read_unlock_bh(&nf_ct_cache_lock
);
647 read_unlock_bh(&nf_ct_cache_lock
);
648 atomic_dec(&nf_conntrack_count
);
652 struct nf_conn
*nf_conntrack_alloc(const struct nf_conntrack_tuple
*orig
,
653 const struct nf_conntrack_tuple
*repl
)
655 struct nf_conntrack_l3proto
*l3proto
;
659 l3proto
= __nf_ct_l3proto_find(orig
->src
.l3num
);
660 ct
= __nf_conntrack_alloc(orig
, repl
, l3proto
, 0);
665 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
667 void nf_conntrack_free(struct nf_conn
*conntrack
)
669 u_int32_t features
= conntrack
->features
;
670 NF_CT_ASSERT(features
>= NF_CT_F_BASIC
&& features
< NF_CT_F_NUM
);
671 DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features
,
673 kmem_cache_free(nf_ct_cache
[features
].cachep
, conntrack
);
674 atomic_dec(&nf_conntrack_count
);
676 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
678 /* Allocate a new conntrack: we return -ENOMEM if classification
679 failed due to stress. Otherwise it really is unclassifiable. */
680 static struct nf_conntrack_tuple_hash
*
681 init_conntrack(const struct nf_conntrack_tuple
*tuple
,
682 struct nf_conntrack_l3proto
*l3proto
,
683 struct nf_conntrack_l4proto
*l4proto
,
685 unsigned int dataoff
)
687 struct nf_conn
*conntrack
;
688 struct nf_conntrack_tuple repl_tuple
;
689 struct nf_conntrack_expect
*exp
;
690 u_int32_t features
= 0;
692 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
693 DEBUGP("Can't invert tuple.\n");
697 read_lock_bh(&nf_conntrack_lock
);
698 exp
= __nf_conntrack_expect_find(tuple
);
699 if (exp
&& exp
->helper
)
700 features
= NF_CT_F_HELP
;
701 read_unlock_bh(&nf_conntrack_lock
);
703 conntrack
= __nf_conntrack_alloc(tuple
, &repl_tuple
, l3proto
, features
);
704 if (conntrack
== NULL
|| IS_ERR(conntrack
)) {
705 DEBUGP("Can't allocate conntrack.\n");
706 return (struct nf_conntrack_tuple_hash
*)conntrack
;
709 if (!l4proto
->new(conntrack
, skb
, dataoff
)) {
710 nf_conntrack_free(conntrack
);
711 DEBUGP("init conntrack: can't track with proto module\n");
715 write_lock_bh(&nf_conntrack_lock
);
716 exp
= find_expectation(tuple
);
719 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
721 /* Welcome, Mr. Bond. We've been expecting you... */
722 __set_bit(IPS_EXPECTED_BIT
, &conntrack
->status
);
723 conntrack
->master
= exp
->master
;
725 nfct_help(conntrack
)->helper
= exp
->helper
;
726 #ifdef CONFIG_NF_CONNTRACK_MARK
727 conntrack
->mark
= exp
->master
->mark
;
729 #ifdef CONFIG_NF_CONNTRACK_SECMARK
730 conntrack
->secmark
= exp
->master
->secmark
;
732 nf_conntrack_get(&conntrack
->master
->ct_general
);
733 NF_CT_STAT_INC(expect_new
);
735 struct nf_conn_help
*help
= nfct_help(conntrack
);
738 help
->helper
= __nf_ct_helper_find(&repl_tuple
);
742 /* Overload tuple linked list to put us in unconfirmed list. */
743 list_add(&conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
, &unconfirmed
);
745 write_unlock_bh(&nf_conntrack_lock
);
749 exp
->expectfn(conntrack
, exp
);
750 nf_conntrack_expect_put(exp
);
753 return &conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
];
756 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
757 static inline struct nf_conn
*
758 resolve_normal_ct(struct sk_buff
*skb
,
759 unsigned int dataoff
,
762 struct nf_conntrack_l3proto
*l3proto
,
763 struct nf_conntrack_l4proto
*l4proto
,
765 enum ip_conntrack_info
*ctinfo
)
767 struct nf_conntrack_tuple tuple
;
768 struct nf_conntrack_tuple_hash
*h
;
771 if (!nf_ct_get_tuple(skb
, (unsigned int)(skb
->nh
.raw
- skb
->data
),
772 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
774 DEBUGP("resolve_normal_ct: Can't get tuple\n");
778 /* look for tuple match */
779 h
= nf_conntrack_find_get(&tuple
, NULL
);
781 h
= init_conntrack(&tuple
, l3proto
, l4proto
, skb
, dataoff
);
787 ct
= nf_ct_tuplehash_to_ctrack(h
);
789 /* It exists; we have (non-exclusive) reference. */
790 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
791 *ctinfo
= IP_CT_ESTABLISHED
+ IP_CT_IS_REPLY
;
792 /* Please set reply bit if this packet OK */
795 /* Once we've had two way comms, always ESTABLISHED. */
796 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
797 DEBUGP("nf_conntrack_in: normal packet for %p\n", ct
);
798 *ctinfo
= IP_CT_ESTABLISHED
;
799 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
800 DEBUGP("nf_conntrack_in: related packet for %p\n", ct
);
801 *ctinfo
= IP_CT_RELATED
;
803 DEBUGP("nf_conntrack_in: new packet for %p\n", ct
);
808 skb
->nfct
= &ct
->ct_general
;
809 skb
->nfctinfo
= *ctinfo
;
814 nf_conntrack_in(int pf
, unsigned int hooknum
, struct sk_buff
**pskb
)
817 enum ip_conntrack_info ctinfo
;
818 struct nf_conntrack_l3proto
*l3proto
;
819 struct nf_conntrack_l4proto
*l4proto
;
820 unsigned int dataoff
;
825 /* Previously seen (loopback or untracked)? Ignore. */
827 NF_CT_STAT_INC_ATOMIC(ignore
);
831 /* rcu_read_lock()ed by nf_hook_slow */
832 l3proto
= __nf_ct_l3proto_find((u_int16_t
)pf
);
834 if ((ret
= l3proto
->prepare(pskb
, hooknum
, &dataoff
, &protonum
)) <= 0) {
835 DEBUGP("not prepared to track yet or error occured\n");
839 l4proto
= __nf_ct_l4proto_find((u_int16_t
)pf
, protonum
);
841 /* It may be an special packet, error, unclean...
842 * inverse of the return code tells to the netfilter
843 * core what to do with the packet. */
844 if (l4proto
->error
!= NULL
&&
845 (ret
= l4proto
->error(*pskb
, dataoff
, &ctinfo
, pf
, hooknum
)) <= 0) {
846 NF_CT_STAT_INC_ATOMIC(error
);
847 NF_CT_STAT_INC_ATOMIC(invalid
);
851 ct
= resolve_normal_ct(*pskb
, dataoff
, pf
, protonum
, l3proto
, l4proto
,
852 &set_reply
, &ctinfo
);
854 /* Not valid part of a connection */
855 NF_CT_STAT_INC_ATOMIC(invalid
);
860 /* Too stressed to deal. */
861 NF_CT_STAT_INC_ATOMIC(drop
);
865 NF_CT_ASSERT((*pskb
)->nfct
);
867 ret
= l4proto
->packet(ct
, *pskb
, dataoff
, ctinfo
, pf
, hooknum
);
869 /* Invalid: inverse of the return code tells
870 * the netfilter core what to do */
871 DEBUGP("nf_conntrack_in: Can't track with proto module\n");
872 nf_conntrack_put((*pskb
)->nfct
);
873 (*pskb
)->nfct
= NULL
;
874 NF_CT_STAT_INC_ATOMIC(invalid
);
878 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
879 nf_conntrack_event_cache(IPCT_STATUS
, *pskb
);
883 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
885 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
886 const struct nf_conntrack_tuple
*orig
)
891 ret
= nf_ct_invert_tuple(inverse
, orig
,
892 __nf_ct_l3proto_find(orig
->src
.l3num
),
893 __nf_ct_l4proto_find(orig
->src
.l3num
,
894 orig
->dst
.protonum
));
898 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
900 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
901 implicitly racy: see __nf_conntrack_confirm */
902 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
903 const struct nf_conntrack_tuple
*newreply
)
905 struct nf_conn_help
*help
= nfct_help(ct
);
907 write_lock_bh(&nf_conntrack_lock
);
908 /* Should be unconfirmed, so not in hash table yet */
909 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
911 DEBUGP("Altering reply tuple of %p to ", ct
);
912 NF_CT_DUMP_TUPLE(newreply
);
914 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
915 if (!ct
->master
&& help
&& help
->expecting
== 0)
916 help
->helper
= __nf_ct_helper_find(newreply
);
917 write_unlock_bh(&nf_conntrack_lock
);
919 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
921 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
922 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
923 enum ip_conntrack_info ctinfo
,
924 const struct sk_buff
*skb
,
925 unsigned long extra_jiffies
,
930 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
933 write_lock_bh(&nf_conntrack_lock
);
935 /* Only update if this is not a fixed timeout */
936 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
)) {
937 write_unlock_bh(&nf_conntrack_lock
);
941 /* If not in hash table, timer will not be active yet */
942 if (!nf_ct_is_confirmed(ct
)) {
943 ct
->timeout
.expires
= extra_jiffies
;
944 event
= IPCT_REFRESH
;
946 unsigned long newtime
= jiffies
+ extra_jiffies
;
948 /* Only update the timeout if the new timeout is at least
949 HZ jiffies from the old timeout. Need del_timer for race
950 avoidance (may already be dying). */
951 if (newtime
- ct
->timeout
.expires
>= HZ
952 && del_timer(&ct
->timeout
)) {
953 ct
->timeout
.expires
= newtime
;
954 add_timer(&ct
->timeout
);
955 event
= IPCT_REFRESH
;
959 #ifdef CONFIG_NF_CT_ACCT
961 ct
->counters
[CTINFO2DIR(ctinfo
)].packets
++;
962 ct
->counters
[CTINFO2DIR(ctinfo
)].bytes
+=
963 skb
->len
- (unsigned int)(skb
->nh
.raw
- skb
->data
);
965 if ((ct
->counters
[CTINFO2DIR(ctinfo
)].packets
& 0x80000000)
966 || (ct
->counters
[CTINFO2DIR(ctinfo
)].bytes
& 0x80000000))
967 event
|= IPCT_COUNTER_FILLING
;
971 write_unlock_bh(&nf_conntrack_lock
);
973 /* must be unlocked when calling event cache */
975 nf_conntrack_event_cache(event
, skb
);
977 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
979 #if defined(CONFIG_NF_CT_NETLINK) || \
980 defined(CONFIG_NF_CT_NETLINK_MODULE)
982 #include <linux/netfilter/nfnetlink.h>
983 #include <linux/netfilter/nfnetlink_conntrack.h>
984 #include <linux/mutex.h>
987 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
988 * in ip_conntrack_core, since we don't want the protocols to autoload
989 * or depend on ctnetlink */
990 int nf_ct_port_tuple_to_nfattr(struct sk_buff
*skb
,
991 const struct nf_conntrack_tuple
*tuple
)
993 NFA_PUT(skb
, CTA_PROTO_SRC_PORT
, sizeof(u_int16_t
),
994 &tuple
->src
.u
.tcp
.port
);
995 NFA_PUT(skb
, CTA_PROTO_DST_PORT
, sizeof(u_int16_t
),
996 &tuple
->dst
.u
.tcp
.port
);
1002 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr
);
1004 static const size_t cta_min_proto
[CTA_PROTO_MAX
] = {
1005 [CTA_PROTO_SRC_PORT
-1] = sizeof(u_int16_t
),
1006 [CTA_PROTO_DST_PORT
-1] = sizeof(u_int16_t
)
1009 int nf_ct_port_nfattr_to_tuple(struct nfattr
*tb
[],
1010 struct nf_conntrack_tuple
*t
)
1012 if (!tb
[CTA_PROTO_SRC_PORT
-1] || !tb
[CTA_PROTO_DST_PORT
-1])
1015 if (nfattr_bad_size(tb
, CTA_PROTO_MAX
, cta_min_proto
))
1018 t
->src
.u
.tcp
.port
= *(__be16
*)NFA_DATA(tb
[CTA_PROTO_SRC_PORT
-1]);
1019 t
->dst
.u
.tcp
.port
= *(__be16
*)NFA_DATA(tb
[CTA_PROTO_DST_PORT
-1]);
1023 EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple
);
1026 /* Used by ipt_REJECT and ip6t_REJECT. */
1027 void __nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1030 enum ip_conntrack_info ctinfo
;
1032 /* This ICMP is in reverse direction to the packet which caused it */
1033 ct
= nf_ct_get(skb
, &ctinfo
);
1034 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1035 ctinfo
= IP_CT_RELATED
+ IP_CT_IS_REPLY
;
1037 ctinfo
= IP_CT_RELATED
;
1039 /* Attach to new skbuff, and increment count */
1040 nskb
->nfct
= &ct
->ct_general
;
1041 nskb
->nfctinfo
= ctinfo
;
1042 nf_conntrack_get(nskb
->nfct
);
1044 EXPORT_SYMBOL_GPL(__nf_conntrack_attach
);
1047 do_iter(const struct nf_conntrack_tuple_hash
*i
,
1048 int (*iter
)(struct nf_conn
*i
, void *data
),
1051 return iter(nf_ct_tuplehash_to_ctrack(i
), data
);
1054 /* Bring out ya dead! */
1055 static struct nf_conn
*
1056 get_next_corpse(int (*iter
)(struct nf_conn
*i
, void *data
),
1057 void *data
, unsigned int *bucket
)
1059 struct nf_conntrack_tuple_hash
*h
;
1062 write_lock_bh(&nf_conntrack_lock
);
1063 for (; *bucket
< nf_conntrack_htable_size
; (*bucket
)++) {
1064 list_for_each_entry(h
, &nf_conntrack_hash
[*bucket
], list
) {
1065 ct
= nf_ct_tuplehash_to_ctrack(h
);
1070 list_for_each_entry(h
, &unconfirmed
, list
) {
1071 ct
= nf_ct_tuplehash_to_ctrack(h
);
1075 write_unlock_bh(&nf_conntrack_lock
);
1078 atomic_inc(&ct
->ct_general
.use
);
1079 write_unlock_bh(&nf_conntrack_lock
);
1084 nf_ct_iterate_cleanup(int (*iter
)(struct nf_conn
*i
, void *data
), void *data
)
1087 unsigned int bucket
= 0;
1089 while ((ct
= get_next_corpse(iter
, data
, &bucket
)) != NULL
) {
1090 /* Time to push up daises... */
1091 if (del_timer(&ct
->timeout
))
1092 death_by_timeout((unsigned long)ct
);
1093 /* ... else the timer will get him soon. */
1098 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1100 static int kill_all(struct nf_conn
*i
, void *data
)
1105 static void free_conntrack_hash(struct list_head
*hash
, int vmalloced
, int size
)
1110 free_pages((unsigned long)hash
,
1111 get_order(sizeof(struct list_head
) * size
));
1114 void nf_conntrack_flush(void)
1116 nf_ct_iterate_cleanup(kill_all
, NULL
);
1118 EXPORT_SYMBOL_GPL(nf_conntrack_flush
);
1120 /* Mishearing the voices in his head, our hero wonders how he's
1121 supposed to kill the mall. */
1122 void nf_conntrack_cleanup(void)
1126 rcu_assign_pointer(ip_ct_attach
, NULL
);
1128 /* This makes sure all current packets have passed through
1129 netfilter framework. Roll on, two-stage module
1133 nf_ct_event_cache_flush();
1135 nf_conntrack_flush();
1136 if (atomic_read(&nf_conntrack_count
) != 0) {
1138 goto i_see_dead_people
;
1140 /* wait until all references to nf_conntrack_untracked are dropped */
1141 while (atomic_read(&nf_conntrack_untracked
.ct_general
.use
) > 1)
1144 for (i
= 0; i
< NF_CT_F_NUM
; i
++) {
1145 if (nf_ct_cache
[i
].use
== 0)
1148 NF_CT_ASSERT(nf_ct_cache
[i
].use
== 1);
1149 nf_ct_cache
[i
].use
= 1;
1150 nf_conntrack_unregister_cache(i
);
1152 kmem_cache_destroy(nf_conntrack_expect_cachep
);
1153 free_conntrack_hash(nf_conntrack_hash
, nf_conntrack_vmalloc
,
1154 nf_conntrack_htable_size
);
1156 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic
);
1158 /* free l3proto protocol tables */
1159 for (i
= 0; i
< PF_MAX
; i
++)
1160 if (nf_ct_protos
[i
]) {
1161 kfree(nf_ct_protos
[i
]);
1162 nf_ct_protos
[i
] = NULL
;
1166 static struct list_head
*alloc_hashtable(int size
, int *vmalloced
)
1168 struct list_head
*hash
;
1172 hash
= (void*)__get_free_pages(GFP_KERNEL
,
1173 get_order(sizeof(struct list_head
)
1177 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1178 hash
= vmalloc(sizeof(struct list_head
) * size
);
1182 for (i
= 0; i
< size
; i
++)
1183 INIT_LIST_HEAD(&hash
[i
]);
1188 int set_hashsize(const char *val
, struct kernel_param
*kp
)
1190 int i
, bucket
, hashsize
, vmalloced
;
1191 int old_vmalloced
, old_size
;
1193 struct list_head
*hash
, *old_hash
;
1194 struct nf_conntrack_tuple_hash
*h
;
1196 /* On boot, we can set this without any fancy locking. */
1197 if (!nf_conntrack_htable_size
)
1198 return param_set_uint(val
, kp
);
1200 hashsize
= simple_strtol(val
, NULL
, 0);
1204 hash
= alloc_hashtable(hashsize
, &vmalloced
);
1208 /* We have to rehahs for the new table anyway, so we also can
1209 * use a newrandom seed */
1210 get_random_bytes(&rnd
, 4);
1212 write_lock_bh(&nf_conntrack_lock
);
1213 for (i
= 0; i
< nf_conntrack_htable_size
; i
++) {
1214 while (!list_empty(&nf_conntrack_hash
[i
])) {
1215 h
= list_entry(nf_conntrack_hash
[i
].next
,
1216 struct nf_conntrack_tuple_hash
, list
);
1218 bucket
= __hash_conntrack(&h
->tuple
, hashsize
, rnd
);
1219 list_add_tail(&h
->list
, &hash
[bucket
]);
1222 old_size
= nf_conntrack_htable_size
;
1223 old_vmalloced
= nf_conntrack_vmalloc
;
1224 old_hash
= nf_conntrack_hash
;
1226 nf_conntrack_htable_size
= hashsize
;
1227 nf_conntrack_vmalloc
= vmalloced
;
1228 nf_conntrack_hash
= hash
;
1229 nf_conntrack_hash_rnd
= rnd
;
1230 write_unlock_bh(&nf_conntrack_lock
);
1232 free_conntrack_hash(old_hash
, old_vmalloced
, old_size
);
1236 module_param_call(hashsize
, set_hashsize
, param_get_uint
,
1237 &nf_conntrack_htable_size
, 0600);
1239 int __init
nf_conntrack_init(void)
1244 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1245 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */
1246 if (!nf_conntrack_htable_size
) {
1247 nf_conntrack_htable_size
1248 = (((num_physpages
<< PAGE_SHIFT
) / 16384)
1249 / sizeof(struct list_head
));
1250 if (num_physpages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1251 nf_conntrack_htable_size
= 8192;
1252 if (nf_conntrack_htable_size
< 16)
1253 nf_conntrack_htable_size
= 16;
1255 nf_conntrack_max
= 8 * nf_conntrack_htable_size
;
1257 printk("nf_conntrack version %s (%u buckets, %d max)\n",
1258 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1261 nf_conntrack_hash
= alloc_hashtable(nf_conntrack_htable_size
,
1262 &nf_conntrack_vmalloc
);
1263 if (!nf_conntrack_hash
) {
1264 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1268 ret
= nf_conntrack_register_cache(NF_CT_F_BASIC
, "nf_conntrack:basic",
1269 sizeof(struct nf_conn
));
1271 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1275 nf_conntrack_expect_cachep
= kmem_cache_create("nf_conntrack_expect",
1276 sizeof(struct nf_conntrack_expect
),
1278 if (!nf_conntrack_expect_cachep
) {
1279 printk(KERN_ERR
"Unable to create nf_expect slab cache\n");
1280 goto err_free_conntrack_slab
;
1283 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic
);
1285 goto out_free_expect_slab
;
1287 /* Don't NEED lock here, but good form anyway. */
1288 write_lock_bh(&nf_conntrack_lock
);
1289 for (i
= 0; i
< AF_MAX
; i
++)
1290 nf_ct_l3protos
[i
] = &nf_conntrack_l3proto_generic
;
1291 write_unlock_bh(&nf_conntrack_lock
);
1293 /* For use by REJECT target */
1294 rcu_assign_pointer(ip_ct_attach
, __nf_conntrack_attach
);
1296 /* Set up fake conntrack:
1297 - to never be deleted, not in any hashes */
1298 atomic_set(&nf_conntrack_untracked
.ct_general
.use
, 1);
1299 /* - and look it like as a confirmed connection */
1300 set_bit(IPS_CONFIRMED_BIT
, &nf_conntrack_untracked
.status
);
1304 out_free_expect_slab
:
1305 kmem_cache_destroy(nf_conntrack_expect_cachep
);
1306 err_free_conntrack_slab
:
1307 nf_conntrack_unregister_cache(NF_CT_F_BASIC
);
1309 free_conntrack_hash(nf_conntrack_hash
, nf_conntrack_vmalloc
,
1310 nf_conntrack_htable_size
);