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.
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/skbuff.h>
19 #include <linux/proc_fs.h>
20 #include <linux/vmalloc.h>
21 #include <linux/stddef.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/jhash.h>
25 #include <linux/err.h>
26 #include <linux/percpu.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/kernel.h>
30 #include <linux/netdevice.h>
31 #include <linux/socket.h>
33 #include <linux/nsproxy.h>
34 #include <linux/rculist_nulls.h>
36 #include <net/netfilter/nf_conntrack.h>
37 #include <net/netfilter/nf_conntrack_l3proto.h>
38 #include <net/netfilter/nf_conntrack_l4proto.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_core.h>
42 #include <net/netfilter/nf_conntrack_extend.h>
43 #include <net/netfilter/nf_conntrack_acct.h>
44 #include <net/netfilter/nf_conntrack_ecache.h>
45 #include <net/netfilter/nf_conntrack_zones.h>
46 #include <net/netfilter/nf_nat.h>
47 #include <net/netfilter/nf_nat_core.h>
49 #define NF_CONNTRACK_VERSION "0.5.0"
51 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
52 enum nf_nat_manip_type manip
,
53 const struct nlattr
*attr
) __read_mostly
;
54 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
56 DEFINE_SPINLOCK(nf_conntrack_lock
);
57 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
59 unsigned int nf_conntrack_htable_size __read_mostly
;
60 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
62 unsigned int nf_conntrack_max __read_mostly
;
63 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
65 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
66 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
68 static unsigned int nf_conntrack_hash_rnd __read_mostly
;
70 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
74 /* The direction must be ignored, so we hash everything up to the
75 * destination ports (which is a multiple of 4) and treat the last
76 * three bytes manually.
78 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
79 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
80 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
81 tuple
->dst
.protonum
));
84 static u32
__hash_bucket(u32 hash
, unsigned int size
)
86 return ((u64
)hash
* size
) >> 32;
89 static u32
hash_bucket(u32 hash
, const struct net
*net
)
91 return __hash_bucket(hash
, net
->ct
.htable_size
);
94 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
95 u16 zone
, unsigned int size
)
97 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
100 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
101 const struct nf_conntrack_tuple
*tuple
)
103 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
107 nf_ct_get_tuple(const struct sk_buff
*skb
,
109 unsigned int dataoff
,
112 struct nf_conntrack_tuple
*tuple
,
113 const struct nf_conntrack_l3proto
*l3proto
,
114 const struct nf_conntrack_l4proto
*l4proto
)
116 memset(tuple
, 0, sizeof(*tuple
));
118 tuple
->src
.l3num
= l3num
;
119 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
122 tuple
->dst
.protonum
= protonum
;
123 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
125 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
127 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
129 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
130 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
132 struct nf_conntrack_l3proto
*l3proto
;
133 struct nf_conntrack_l4proto
*l4proto
;
134 unsigned int protoff
;
140 l3proto
= __nf_ct_l3proto_find(l3num
);
141 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
142 if (ret
!= NF_ACCEPT
) {
147 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
149 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
155 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
158 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
159 const struct nf_conntrack_tuple
*orig
,
160 const struct nf_conntrack_l3proto
*l3proto
,
161 const struct nf_conntrack_l4proto
*l4proto
)
163 memset(inverse
, 0, sizeof(*inverse
));
165 inverse
->src
.l3num
= orig
->src
.l3num
;
166 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
169 inverse
->dst
.dir
= !orig
->dst
.dir
;
171 inverse
->dst
.protonum
= orig
->dst
.protonum
;
172 return l4proto
->invert_tuple(inverse
, orig
);
174 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
177 clean_from_lists(struct nf_conn
*ct
)
179 pr_debug("clean_from_lists(%p)\n", ct
);
180 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
181 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
183 /* Destroy all pending expectations */
184 nf_ct_remove_expectations(ct
);
188 destroy_conntrack(struct nf_conntrack
*nfct
)
190 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
191 struct net
*net
= nf_ct_net(ct
);
192 struct nf_conntrack_l4proto
*l4proto
;
194 pr_debug("destroy_conntrack(%p)\n", ct
);
195 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
196 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
198 /* To make sure we don't get any weird locking issues here:
199 * destroy_conntrack() MUST NOT be called with a write lock
200 * to nf_conntrack_lock!!! -HW */
202 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
203 if (l4proto
&& l4proto
->destroy
)
204 l4proto
->destroy(ct
);
208 spin_lock_bh(&nf_conntrack_lock
);
209 /* Expectations will have been removed in clean_from_lists,
210 * except TFTP can create an expectation on the first packet,
211 * before connection is in the list, so we need to clean here,
213 nf_ct_remove_expectations(ct
);
215 /* We overload first tuple to link into unconfirmed list. */
216 if (!nf_ct_is_confirmed(ct
)) {
217 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
218 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
221 NF_CT_STAT_INC(net
, delete);
222 spin_unlock_bh(&nf_conntrack_lock
);
225 nf_ct_put(ct
->master
);
227 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
228 nf_conntrack_free(ct
);
231 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
233 struct net
*net
= nf_ct_net(ct
);
235 nf_ct_helper_destroy(ct
);
236 spin_lock_bh(&nf_conntrack_lock
);
237 /* Inside lock so preempt is disabled on module removal path.
238 * Otherwise we can get spurious warnings. */
239 NF_CT_STAT_INC(net
, delete_list
);
240 clean_from_lists(ct
);
241 spin_unlock_bh(&nf_conntrack_lock
);
243 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
245 static void death_by_event(unsigned long ul_conntrack
)
247 struct nf_conn
*ct
= (void *)ul_conntrack
;
248 struct net
*net
= nf_ct_net(ct
);
250 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
251 /* bad luck, let's retry again */
252 ct
->timeout
.expires
= jiffies
+
253 (random32() % net
->ct
.sysctl_events_retry_timeout
);
254 add_timer(&ct
->timeout
);
257 /* we've got the event delivered, now it's dying */
258 set_bit(IPS_DYING_BIT
, &ct
->status
);
259 spin_lock(&nf_conntrack_lock
);
260 hlist_nulls_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
261 spin_unlock(&nf_conntrack_lock
);
265 void nf_ct_insert_dying_list(struct nf_conn
*ct
)
267 struct net
*net
= nf_ct_net(ct
);
269 /* add this conntrack to the dying list */
270 spin_lock_bh(&nf_conntrack_lock
);
271 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
273 spin_unlock_bh(&nf_conntrack_lock
);
274 /* set a new timer to retry event delivery */
275 setup_timer(&ct
->timeout
, death_by_event
, (unsigned long)ct
);
276 ct
->timeout
.expires
= jiffies
+
277 (random32() % net
->ct
.sysctl_events_retry_timeout
);
278 add_timer(&ct
->timeout
);
280 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list
);
282 static void death_by_timeout(unsigned long ul_conntrack
)
284 struct nf_conn
*ct
= (void *)ul_conntrack
;
286 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
287 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
288 /* destroy event was not delivered */
289 nf_ct_delete_from_lists(ct
);
290 nf_ct_insert_dying_list(ct
);
293 set_bit(IPS_DYING_BIT
, &ct
->status
);
294 nf_ct_delete_from_lists(ct
);
300 * - Caller must take a reference on returned object
301 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
303 * - Caller must lock nf_conntrack_lock before calling this function
305 static struct nf_conntrack_tuple_hash
*
306 ____nf_conntrack_find(struct net
*net
, u16 zone
,
307 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
309 struct nf_conntrack_tuple_hash
*h
;
310 struct hlist_nulls_node
*n
;
311 unsigned int bucket
= hash_bucket(hash
, net
);
313 /* Disable BHs the entire time since we normally need to disable them
314 * at least once for the stats anyway.
318 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
319 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
320 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
321 NF_CT_STAT_INC(net
, found
);
325 NF_CT_STAT_INC(net
, searched
);
328 * if the nulls value we got at the end of this lookup is
329 * not the expected one, we must restart lookup.
330 * We probably met an item that was moved to another chain.
332 if (get_nulls_value(n
) != bucket
) {
333 NF_CT_STAT_INC(net
, search_restart
);
341 struct nf_conntrack_tuple_hash
*
342 __nf_conntrack_find(struct net
*net
, u16 zone
,
343 const struct nf_conntrack_tuple
*tuple
)
345 return ____nf_conntrack_find(net
, zone
, tuple
,
346 hash_conntrack_raw(tuple
, zone
));
348 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
350 /* Find a connection corresponding to a tuple. */
351 static struct nf_conntrack_tuple_hash
*
352 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
353 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
355 struct nf_conntrack_tuple_hash
*h
;
360 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
362 ct
= nf_ct_tuplehash_to_ctrack(h
);
363 if (unlikely(nf_ct_is_dying(ct
) ||
364 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
367 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
368 nf_ct_zone(ct
) != zone
)) {
379 struct nf_conntrack_tuple_hash
*
380 nf_conntrack_find_get(struct net
*net
, u16 zone
,
381 const struct nf_conntrack_tuple
*tuple
)
383 return __nf_conntrack_find_get(net
, zone
, tuple
,
384 hash_conntrack_raw(tuple
, zone
));
386 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
388 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
390 unsigned int repl_hash
)
392 struct net
*net
= nf_ct_net(ct
);
394 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
395 &net
->ct
.hash
[hash
]);
396 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
397 &net
->ct
.hash
[repl_hash
]);
400 void nf_conntrack_hash_insert(struct nf_conn
*ct
)
402 struct net
*net
= nf_ct_net(ct
);
403 unsigned int hash
, repl_hash
;
406 zone
= nf_ct_zone(ct
);
407 hash
= hash_conntrack(net
, zone
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
408 repl_hash
= hash_conntrack(net
, zone
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
410 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
412 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert
);
414 /* Confirm a connection given skb; places it in hash table */
416 __nf_conntrack_confirm(struct sk_buff
*skb
)
418 unsigned int hash
, repl_hash
;
419 struct nf_conntrack_tuple_hash
*h
;
421 struct nf_conn_help
*help
;
422 struct hlist_nulls_node
*n
;
423 enum ip_conntrack_info ctinfo
;
427 ct
= nf_ct_get(skb
, &ctinfo
);
430 /* ipt_REJECT uses nf_conntrack_attach to attach related
431 ICMP/TCP RST packets in other direction. Actual packet
432 which created connection will be IP_CT_NEW or for an
433 expected connection, IP_CT_RELATED. */
434 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
437 zone
= nf_ct_zone(ct
);
438 /* reuse the hash saved before */
439 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
440 hash
= hash_bucket(hash
, net
);
441 repl_hash
= hash_conntrack(net
, zone
,
442 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
444 /* We're not in hash table, and we refuse to set up related
445 connections for unconfirmed conns. But packet copies and
446 REJECT will give spurious warnings here. */
447 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
449 /* No external references means noone else could have
451 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
452 pr_debug("Confirming conntrack %p\n", ct
);
454 spin_lock_bh(&nf_conntrack_lock
);
456 /* We have to check the DYING flag inside the lock to prevent
457 a race against nf_ct_get_next_corpse() possibly called from
458 user context, else we insert an already 'dead' hash, blocking
459 further use of that particular connection -JM */
461 if (unlikely(nf_ct_is_dying(ct
))) {
462 spin_unlock_bh(&nf_conntrack_lock
);
466 /* See if there's one in the list already, including reverse:
467 NAT could have grabbed it without realizing, since we're
468 not in the hash. If there is, we lost race. */
469 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
470 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
472 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
474 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
475 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
477 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
480 /* Remove from unconfirmed list */
481 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
483 /* Timer relative to confirmation time, not original
484 setting time, otherwise we'd get timer wrap in
485 weird delay cases. */
486 ct
->timeout
.expires
+= jiffies
;
487 add_timer(&ct
->timeout
);
488 atomic_inc(&ct
->ct_general
.use
);
489 set_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
491 /* Since the lookup is lockless, hash insertion must be done after
492 * starting the timer and setting the CONFIRMED bit. The RCU barriers
493 * guarantee that no other CPU can find the conntrack before the above
494 * stores are visible.
496 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
497 NF_CT_STAT_INC(net
, insert
);
498 spin_unlock_bh(&nf_conntrack_lock
);
500 help
= nfct_help(ct
);
501 if (help
&& help
->helper
)
502 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
504 nf_conntrack_event_cache(master_ct(ct
) ?
505 IPCT_RELATED
: IPCT_NEW
, ct
);
509 NF_CT_STAT_INC(net
, insert_failed
);
510 spin_unlock_bh(&nf_conntrack_lock
);
513 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
515 /* Returns true if a connection correspondings to the tuple (required
518 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
519 const struct nf_conn
*ignored_conntrack
)
521 struct net
*net
= nf_ct_net(ignored_conntrack
);
522 struct nf_conntrack_tuple_hash
*h
;
523 struct hlist_nulls_node
*n
;
525 u16 zone
= nf_ct_zone(ignored_conntrack
);
526 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
528 /* Disable BHs the entire time since we need to disable them at
529 * least once for the stats anyway.
532 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
533 ct
= nf_ct_tuplehash_to_ctrack(h
);
534 if (ct
!= ignored_conntrack
&&
535 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
536 nf_ct_zone(ct
) == zone
) {
537 NF_CT_STAT_INC(net
, found
);
538 rcu_read_unlock_bh();
541 NF_CT_STAT_INC(net
, searched
);
543 rcu_read_unlock_bh();
547 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
549 #define NF_CT_EVICTION_RANGE 8
551 /* There's a small race here where we may free a just-assured
552 connection. Too bad: we're in trouble anyway. */
553 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
555 /* Use oldest entry, which is roughly LRU */
556 struct nf_conntrack_tuple_hash
*h
;
557 struct nf_conn
*ct
= NULL
, *tmp
;
558 struct hlist_nulls_node
*n
;
559 unsigned int i
, cnt
= 0;
563 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
564 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
566 tmp
= nf_ct_tuplehash_to_ctrack(h
);
567 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
573 if (likely(!nf_ct_is_dying(ct
) &&
574 atomic_inc_not_zero(&ct
->ct_general
.use
)))
580 if (cnt
>= NF_CT_EVICTION_RANGE
)
583 hash
= (hash
+ 1) % net
->ct
.htable_size
;
590 if (del_timer(&ct
->timeout
)) {
591 death_by_timeout((unsigned long)ct
);
593 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
599 static struct nf_conn
*
600 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
601 const struct nf_conntrack_tuple
*orig
,
602 const struct nf_conntrack_tuple
*repl
,
607 if (unlikely(!nf_conntrack_hash_rnd
)) {
611 * Why not initialize nf_conntrack_rnd in a "init()" function ?
612 * Because there isn't enough entropy when system initializing,
613 * and we initialize it as late as possible.
616 get_random_bytes(&rand
, sizeof(rand
));
618 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
620 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
621 hash
= hash_conntrack_raw(orig
, zone
);
624 /* We don't want any race condition at early drop stage */
625 atomic_inc(&net
->ct
.count
);
627 if (nf_conntrack_max
&&
628 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
629 if (!early_drop(net
, hash_bucket(hash
, net
))) {
630 atomic_dec(&net
->ct
.count
);
633 "nf_conntrack: table full, dropping"
635 return ERR_PTR(-ENOMEM
);
640 * Do not use kmem_cache_zalloc(), as this cache uses
641 * SLAB_DESTROY_BY_RCU.
643 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
645 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
646 atomic_dec(&net
->ct
.count
);
647 return ERR_PTR(-ENOMEM
);
650 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
651 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
653 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
654 sizeof(*ct
) - offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
655 spin_lock_init(&ct
->lock
);
656 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
657 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
658 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
659 /* save hash for reusing when confirming */
660 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
661 /* Don't set timer yet: wait for confirmation */
662 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
663 write_pnet(&ct
->ct_net
, net
);
664 #ifdef CONFIG_NF_CONNTRACK_ZONES
666 struct nf_conntrack_zone
*nf_ct_zone
;
668 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
671 nf_ct_zone
->id
= zone
;
675 * changes to lookup keys must be done before setting refcnt to 1
678 atomic_set(&ct
->ct_general
.use
, 1);
681 #ifdef CONFIG_NF_CONNTRACK_ZONES
683 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
684 return ERR_PTR(-ENOMEM
);
688 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
689 const struct nf_conntrack_tuple
*orig
,
690 const struct nf_conntrack_tuple
*repl
,
693 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
695 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
697 void nf_conntrack_free(struct nf_conn
*ct
)
699 struct net
*net
= nf_ct_net(ct
);
701 nf_ct_ext_destroy(ct
);
702 atomic_dec(&net
->ct
.count
);
704 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
706 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
708 /* Allocate a new conntrack: we return -ENOMEM if classification
709 failed due to stress. Otherwise it really is unclassifiable. */
710 static struct nf_conntrack_tuple_hash
*
711 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
712 const struct nf_conntrack_tuple
*tuple
,
713 struct nf_conntrack_l3proto
*l3proto
,
714 struct nf_conntrack_l4proto
*l4proto
,
716 unsigned int dataoff
, u32 hash
)
719 struct nf_conn_help
*help
;
720 struct nf_conntrack_tuple repl_tuple
;
721 struct nf_conntrack_ecache
*ecache
;
722 struct nf_conntrack_expect
*exp
;
723 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
725 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
726 pr_debug("Can't invert tuple.\n");
730 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
733 pr_debug("Can't allocate conntrack.\n");
734 return (struct nf_conntrack_tuple_hash
*)ct
;
737 if (!l4proto
->new(ct
, skb
, dataoff
)) {
738 nf_conntrack_free(ct
);
739 pr_debug("init conntrack: can't track with proto module\n");
743 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
745 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
746 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
747 ecache
? ecache
->expmask
: 0,
750 spin_lock_bh(&nf_conntrack_lock
);
751 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
753 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
755 /* Welcome, Mr. Bond. We've been expecting you... */
756 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
757 ct
->master
= exp
->master
;
759 help
= nf_ct_helper_ext_add(ct
, GFP_ATOMIC
);
761 rcu_assign_pointer(help
->helper
, exp
->helper
);
764 #ifdef CONFIG_NF_CONNTRACK_MARK
765 ct
->mark
= exp
->master
->mark
;
767 #ifdef CONFIG_NF_CONNTRACK_SECMARK
768 ct
->secmark
= exp
->master
->secmark
;
770 nf_conntrack_get(&ct
->master
->ct_general
);
771 NF_CT_STAT_INC(net
, expect_new
);
773 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
774 NF_CT_STAT_INC(net
, new);
777 /* Overload tuple linked list to put us in unconfirmed list. */
778 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
779 &net
->ct
.unconfirmed
);
781 spin_unlock_bh(&nf_conntrack_lock
);
785 exp
->expectfn(ct
, exp
);
786 nf_ct_expect_put(exp
);
789 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
792 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
793 static inline struct nf_conn
*
794 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
796 unsigned int dataoff
,
799 struct nf_conntrack_l3proto
*l3proto
,
800 struct nf_conntrack_l4proto
*l4proto
,
802 enum ip_conntrack_info
*ctinfo
)
804 struct nf_conntrack_tuple tuple
;
805 struct nf_conntrack_tuple_hash
*h
;
807 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
810 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
811 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
813 pr_debug("resolve_normal_ct: Can't get tuple\n");
817 /* look for tuple match */
818 hash
= hash_conntrack_raw(&tuple
, zone
);
819 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
821 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
828 ct
= nf_ct_tuplehash_to_ctrack(h
);
830 /* It exists; we have (non-exclusive) reference. */
831 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
832 *ctinfo
= IP_CT_ESTABLISHED
+ IP_CT_IS_REPLY
;
833 /* Please set reply bit if this packet OK */
836 /* Once we've had two way comms, always ESTABLISHED. */
837 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
838 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
839 *ctinfo
= IP_CT_ESTABLISHED
;
840 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
841 pr_debug("nf_conntrack_in: related packet for %p\n",
843 *ctinfo
= IP_CT_RELATED
;
845 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
850 skb
->nfct
= &ct
->ct_general
;
851 skb
->nfctinfo
= *ctinfo
;
856 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
859 struct nf_conn
*ct
, *tmpl
= NULL
;
860 enum ip_conntrack_info ctinfo
;
861 struct nf_conntrack_l3proto
*l3proto
;
862 struct nf_conntrack_l4proto
*l4proto
;
863 unsigned int dataoff
;
869 /* Previously seen (loopback or untracked)? Ignore. */
870 tmpl
= (struct nf_conn
*)skb
->nfct
;
871 if (!nf_ct_is_template(tmpl
)) {
872 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
878 /* rcu_read_lock()ed by nf_hook_slow */
879 l3proto
= __nf_ct_l3proto_find(pf
);
880 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
881 &dataoff
, &protonum
);
883 pr_debug("not prepared to track yet or error occured\n");
884 NF_CT_STAT_INC_ATOMIC(net
, error
);
885 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
890 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
892 /* It may be an special packet, error, unclean...
893 * inverse of the return code tells to the netfilter
894 * core what to do with the packet. */
895 if (l4proto
->error
!= NULL
) {
896 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
899 NF_CT_STAT_INC_ATOMIC(net
, error
);
900 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
906 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
907 l3proto
, l4proto
, &set_reply
, &ctinfo
);
909 /* Not valid part of a connection */
910 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
916 /* Too stressed to deal. */
917 NF_CT_STAT_INC_ATOMIC(net
, drop
);
922 NF_CT_ASSERT(skb
->nfct
);
924 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
);
926 /* Invalid: inverse of the return code tells
927 * the netfilter core what to do */
928 pr_debug("nf_conntrack_in: Can't track with proto module\n");
929 nf_conntrack_put(skb
->nfct
);
931 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
933 NF_CT_STAT_INC_ATOMIC(net
, drop
);
938 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
939 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
946 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
948 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
949 const struct nf_conntrack_tuple
*orig
)
954 ret
= nf_ct_invert_tuple(inverse
, orig
,
955 __nf_ct_l3proto_find(orig
->src
.l3num
),
956 __nf_ct_l4proto_find(orig
->src
.l3num
,
957 orig
->dst
.protonum
));
961 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
963 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
964 implicitly racy: see __nf_conntrack_confirm */
965 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
966 const struct nf_conntrack_tuple
*newreply
)
968 struct nf_conn_help
*help
= nfct_help(ct
);
970 /* Should be unconfirmed, so not in hash table yet */
971 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
973 pr_debug("Altering reply tuple of %p to ", ct
);
974 nf_ct_dump_tuple(newreply
);
976 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
977 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
981 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
984 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
986 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
987 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
988 enum ip_conntrack_info ctinfo
,
989 const struct sk_buff
*skb
,
990 unsigned long extra_jiffies
,
993 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
996 /* Only update if this is not a fixed timeout */
997 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1000 /* If not in hash table, timer will not be active yet */
1001 if (!nf_ct_is_confirmed(ct
)) {
1002 ct
->timeout
.expires
= extra_jiffies
;
1004 unsigned long newtime
= jiffies
+ extra_jiffies
;
1006 /* Only update the timeout if the new timeout is at least
1007 HZ jiffies from the old timeout. Need del_timer for race
1008 avoidance (may already be dying). */
1009 if (newtime
- ct
->timeout
.expires
>= HZ
)
1010 mod_timer_pending(&ct
->timeout
, newtime
);
1015 struct nf_conn_counter
*acct
;
1017 acct
= nf_conn_acct_find(ct
);
1019 spin_lock_bh(&ct
->lock
);
1020 acct
[CTINFO2DIR(ctinfo
)].packets
++;
1021 acct
[CTINFO2DIR(ctinfo
)].bytes
+= skb
->len
;
1022 spin_unlock_bh(&ct
->lock
);
1026 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1028 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1029 enum ip_conntrack_info ctinfo
,
1030 const struct sk_buff
*skb
,
1034 struct nf_conn_counter
*acct
;
1036 acct
= nf_conn_acct_find(ct
);
1038 spin_lock_bh(&ct
->lock
);
1039 acct
[CTINFO2DIR(ctinfo
)].packets
++;
1040 acct
[CTINFO2DIR(ctinfo
)].bytes
+=
1041 skb
->len
- skb_network_offset(skb
);
1042 spin_unlock_bh(&ct
->lock
);
1046 if (del_timer(&ct
->timeout
)) {
1047 ct
->timeout
.function((unsigned long)ct
);
1052 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1054 #ifdef CONFIG_NF_CONNTRACK_ZONES
1055 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1056 .len
= sizeof(struct nf_conntrack_zone
),
1057 .align
= __alignof__(struct nf_conntrack_zone
),
1058 .id
= NF_CT_EXT_ZONE
,
1062 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1064 #include <linux/netfilter/nfnetlink.h>
1065 #include <linux/netfilter/nfnetlink_conntrack.h>
1066 #include <linux/mutex.h>
1068 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1069 * in ip_conntrack_core, since we don't want the protocols to autoload
1070 * or depend on ctnetlink */
1071 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1072 const struct nf_conntrack_tuple
*tuple
)
1074 NLA_PUT_BE16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
);
1075 NLA_PUT_BE16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
);
1081 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1083 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1084 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1085 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1087 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1089 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1090 struct nf_conntrack_tuple
*t
)
1092 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1095 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1096 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1100 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1102 int nf_ct_port_nlattr_tuple_size(void)
1104 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1106 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1109 /* Used by ipt_REJECT and ip6t_REJECT. */
1110 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1113 enum ip_conntrack_info ctinfo
;
1115 /* This ICMP is in reverse direction to the packet which caused it */
1116 ct
= nf_ct_get(skb
, &ctinfo
);
1117 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1118 ctinfo
= IP_CT_RELATED
+ IP_CT_IS_REPLY
;
1120 ctinfo
= IP_CT_RELATED
;
1122 /* Attach to new skbuff, and increment count */
1123 nskb
->nfct
= &ct
->ct_general
;
1124 nskb
->nfctinfo
= ctinfo
;
1125 nf_conntrack_get(nskb
->nfct
);
1128 /* Bring out ya dead! */
1129 static struct nf_conn
*
1130 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1131 void *data
, unsigned int *bucket
)
1133 struct nf_conntrack_tuple_hash
*h
;
1135 struct hlist_nulls_node
*n
;
1137 spin_lock_bh(&nf_conntrack_lock
);
1138 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1139 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1140 ct
= nf_ct_tuplehash_to_ctrack(h
);
1145 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1146 ct
= nf_ct_tuplehash_to_ctrack(h
);
1148 set_bit(IPS_DYING_BIT
, &ct
->status
);
1150 spin_unlock_bh(&nf_conntrack_lock
);
1153 atomic_inc(&ct
->ct_general
.use
);
1154 spin_unlock_bh(&nf_conntrack_lock
);
1158 void nf_ct_iterate_cleanup(struct net
*net
,
1159 int (*iter
)(struct nf_conn
*i
, void *data
),
1163 unsigned int bucket
= 0;
1165 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1166 /* Time to push up daises... */
1167 if (del_timer(&ct
->timeout
))
1168 death_by_timeout((unsigned long)ct
);
1169 /* ... else the timer will get him soon. */
1174 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1176 struct __nf_ct_flush_report
{
1181 static int kill_report(struct nf_conn
*i
, void *data
)
1183 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1185 /* If we fail to deliver the event, death_by_timeout() will retry */
1186 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1187 fr
->pid
, fr
->report
) < 0)
1190 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1191 set_bit(IPS_DYING_BIT
, &i
->status
);
1195 static int kill_all(struct nf_conn
*i
, void *data
)
1200 void nf_ct_free_hashtable(void *hash
, int vmalloced
, unsigned int size
)
1205 free_pages((unsigned long)hash
,
1206 get_order(sizeof(struct hlist_head
) * size
));
1208 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1210 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1212 struct __nf_ct_flush_report fr
= {
1216 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1218 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1220 static void nf_ct_release_dying_list(struct net
*net
)
1222 struct nf_conntrack_tuple_hash
*h
;
1224 struct hlist_nulls_node
*n
;
1226 spin_lock_bh(&nf_conntrack_lock
);
1227 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1228 ct
= nf_ct_tuplehash_to_ctrack(h
);
1229 /* never fails to remove them, no listeners at this point */
1232 spin_unlock_bh(&nf_conntrack_lock
);
1235 static int untrack_refs(void)
1239 for_each_possible_cpu(cpu
) {
1240 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1242 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1247 static void nf_conntrack_cleanup_init_net(void)
1249 while (untrack_refs() > 0)
1252 nf_conntrack_helper_fini();
1253 nf_conntrack_proto_fini();
1254 #ifdef CONFIG_NF_CONNTRACK_ZONES
1255 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1259 static void nf_conntrack_cleanup_net(struct net
*net
)
1262 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1263 nf_ct_release_dying_list(net
);
1264 if (atomic_read(&net
->ct
.count
) != 0) {
1266 goto i_see_dead_people
;
1269 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.hash_vmalloc
,
1270 net
->ct
.htable_size
);
1271 nf_conntrack_ecache_fini(net
);
1272 nf_conntrack_acct_fini(net
);
1273 nf_conntrack_expect_fini(net
);
1274 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1275 kfree(net
->ct
.slabname
);
1276 free_percpu(net
->ct
.stat
);
1279 /* Mishearing the voices in his head, our hero wonders how he's
1280 supposed to kill the mall. */
1281 void nf_conntrack_cleanup(struct net
*net
)
1283 if (net_eq(net
, &init_net
))
1284 rcu_assign_pointer(ip_ct_attach
, NULL
);
1286 /* This makes sure all current packets have passed through
1287 netfilter framework. Roll on, two-stage module
1291 nf_conntrack_cleanup_net(net
);
1293 if (net_eq(net
, &init_net
)) {
1294 rcu_assign_pointer(nf_ct_destroy
, NULL
);
1295 nf_conntrack_cleanup_init_net();
1299 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int *vmalloced
, int nulls
)
1301 struct hlist_nulls_head
*hash
;
1302 unsigned int nr_slots
, i
;
1307 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1308 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1309 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1310 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1314 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1315 hash
= __vmalloc(sz
, GFP_KERNEL
| __GFP_ZERO
, PAGE_KERNEL
);
1319 for (i
= 0; i
< nr_slots
; i
++)
1320 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1324 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1326 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1328 int i
, bucket
, vmalloced
, old_vmalloced
;
1329 unsigned int hashsize
, old_size
;
1330 struct hlist_nulls_head
*hash
, *old_hash
;
1331 struct nf_conntrack_tuple_hash
*h
;
1334 if (current
->nsproxy
->net_ns
!= &init_net
)
1337 /* On boot, we can set this without any fancy locking. */
1338 if (!nf_conntrack_htable_size
)
1339 return param_set_uint(val
, kp
);
1341 hashsize
= simple_strtoul(val
, NULL
, 0);
1345 hash
= nf_ct_alloc_hashtable(&hashsize
, &vmalloced
, 1);
1349 /* Lookups in the old hash might happen in parallel, which means we
1350 * might get false negatives during connection lookup. New connections
1351 * created because of a false negative won't make it into the hash
1352 * though since that required taking the lock.
1354 spin_lock_bh(&nf_conntrack_lock
);
1355 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1356 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1357 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1358 struct nf_conntrack_tuple_hash
, hnnode
);
1359 ct
= nf_ct_tuplehash_to_ctrack(h
);
1360 hlist_nulls_del_rcu(&h
->hnnode
);
1361 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1363 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1366 old_size
= init_net
.ct
.htable_size
;
1367 old_vmalloced
= init_net
.ct
.hash_vmalloc
;
1368 old_hash
= init_net
.ct
.hash
;
1370 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1371 init_net
.ct
.hash_vmalloc
= vmalloced
;
1372 init_net
.ct
.hash
= hash
;
1373 spin_unlock_bh(&nf_conntrack_lock
);
1375 nf_ct_free_hashtable(old_hash
, old_vmalloced
, old_size
);
1378 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1380 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1381 &nf_conntrack_htable_size
, 0600);
1383 void nf_ct_untracked_status_or(unsigned long bits
)
1387 for_each_possible_cpu(cpu
)
1388 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1390 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1392 static int nf_conntrack_init_init_net(void)
1397 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1398 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1399 if (!nf_conntrack_htable_size
) {
1400 nf_conntrack_htable_size
1401 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1402 / sizeof(struct hlist_head
));
1403 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1404 nf_conntrack_htable_size
= 16384;
1405 if (nf_conntrack_htable_size
< 32)
1406 nf_conntrack_htable_size
= 32;
1408 /* Use a max. factor of four by default to get the same max as
1409 * with the old struct list_heads. When a table size is given
1410 * we use the old value of 8 to avoid reducing the max.
1414 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1416 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1417 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1420 ret
= nf_conntrack_proto_init();
1424 ret
= nf_conntrack_helper_init();
1428 #ifdef CONFIG_NF_CONNTRACK_ZONES
1429 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1433 /* Set up fake conntrack: to never be deleted, not in any hashes */
1434 for_each_possible_cpu(cpu
) {
1435 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1436 write_pnet(&ct
->ct_net
, &init_net
);
1437 atomic_set(&ct
->ct_general
.use
, 1);
1439 /* - and look it like as a confirmed connection */
1440 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1443 #ifdef CONFIG_NF_CONNTRACK_ZONES
1445 nf_conntrack_helper_fini();
1448 nf_conntrack_proto_fini();
1454 * We need to use special "null" values, not used in hash table
1456 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1457 #define DYING_NULLS_VAL ((1<<30)+1)
1459 static int nf_conntrack_init_net(struct net
*net
)
1463 atomic_set(&net
->ct
.count
, 0);
1464 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1465 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1466 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1467 if (!net
->ct
.stat
) {
1472 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1473 if (!net
->ct
.slabname
) {
1478 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1479 sizeof(struct nf_conn
), 0,
1480 SLAB_DESTROY_BY_RCU
, NULL
);
1481 if (!net
->ct
.nf_conntrack_cachep
) {
1482 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1487 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1488 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
,
1489 &net
->ct
.hash_vmalloc
, 1);
1490 if (!net
->ct
.hash
) {
1492 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1495 ret
= nf_conntrack_expect_init(net
);
1498 ret
= nf_conntrack_acct_init(net
);
1501 ret
= nf_conntrack_ecache_init(net
);
1508 nf_conntrack_acct_fini(net
);
1510 nf_conntrack_expect_fini(net
);
1512 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.hash_vmalloc
,
1513 net
->ct
.htable_size
);
1515 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1517 kfree(net
->ct
.slabname
);
1519 free_percpu(net
->ct
.stat
);
1524 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1525 enum ip_conntrack_dir dir
,
1527 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1529 int nf_conntrack_init(struct net
*net
)
1533 if (net_eq(net
, &init_net
)) {
1534 ret
= nf_conntrack_init_init_net();
1538 ret
= nf_conntrack_init_net(net
);
1542 if (net_eq(net
, &init_net
)) {
1543 /* For use by REJECT target */
1544 rcu_assign_pointer(ip_ct_attach
, nf_conntrack_attach
);
1545 rcu_assign_pointer(nf_ct_destroy
, destroy_conntrack
);
1547 /* Howto get NAT offsets */
1548 rcu_assign_pointer(nf_ct_nat_offset
, NULL
);
1553 if (net_eq(net
, &init_net
))
1554 nf_conntrack_cleanup_init_net();