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_conntrack_timestamp.h>
47 #include <net/netfilter/nf_nat.h>
48 #include <net/netfilter/nf_nat_core.h>
50 #define NF_CONNTRACK_VERSION "0.5.0"
52 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
53 enum nf_nat_manip_type manip
,
54 const struct nlattr
*attr
) __read_mostly
;
55 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
57 DEFINE_SPINLOCK(nf_conntrack_lock
);
58 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
60 unsigned int nf_conntrack_htable_size __read_mostly
;
61 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
63 unsigned int nf_conntrack_max __read_mostly
;
64 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
66 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
67 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
69 unsigned int nf_conntrack_hash_rnd __read_mostly
;
70 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
72 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
76 /* The direction must be ignored, so we hash everything up to the
77 * destination ports (which is a multiple of 4) and treat the last
78 * three bytes manually.
80 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
81 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
82 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
83 tuple
->dst
.protonum
));
86 static u32
__hash_bucket(u32 hash
, unsigned int size
)
88 return ((u64
)hash
* size
) >> 32;
91 static u32
hash_bucket(u32 hash
, const struct net
*net
)
93 return __hash_bucket(hash
, net
->ct
.htable_size
);
96 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
97 u16 zone
, unsigned int size
)
99 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
102 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
103 const struct nf_conntrack_tuple
*tuple
)
105 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
109 nf_ct_get_tuple(const struct sk_buff
*skb
,
111 unsigned int dataoff
,
114 struct nf_conntrack_tuple
*tuple
,
115 const struct nf_conntrack_l3proto
*l3proto
,
116 const struct nf_conntrack_l4proto
*l4proto
)
118 memset(tuple
, 0, sizeof(*tuple
));
120 tuple
->src
.l3num
= l3num
;
121 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
124 tuple
->dst
.protonum
= protonum
;
125 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
127 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
129 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
131 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
132 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
134 struct nf_conntrack_l3proto
*l3proto
;
135 struct nf_conntrack_l4proto
*l4proto
;
136 unsigned int protoff
;
142 l3proto
= __nf_ct_l3proto_find(l3num
);
143 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
144 if (ret
!= NF_ACCEPT
) {
149 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
151 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
157 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
160 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
161 const struct nf_conntrack_tuple
*orig
,
162 const struct nf_conntrack_l3proto
*l3proto
,
163 const struct nf_conntrack_l4proto
*l4proto
)
165 memset(inverse
, 0, sizeof(*inverse
));
167 inverse
->src
.l3num
= orig
->src
.l3num
;
168 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
171 inverse
->dst
.dir
= !orig
->dst
.dir
;
173 inverse
->dst
.protonum
= orig
->dst
.protonum
;
174 return l4proto
->invert_tuple(inverse
, orig
);
176 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
179 clean_from_lists(struct nf_conn
*ct
)
181 pr_debug("clean_from_lists(%p)\n", ct
);
182 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
183 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
185 /* Destroy all pending expectations */
186 nf_ct_remove_expectations(ct
);
190 destroy_conntrack(struct nf_conntrack
*nfct
)
192 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
193 struct net
*net
= nf_ct_net(ct
);
194 struct nf_conntrack_l4proto
*l4proto
;
196 pr_debug("destroy_conntrack(%p)\n", ct
);
197 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
198 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
200 /* To make sure we don't get any weird locking issues here:
201 * destroy_conntrack() MUST NOT be called with a write lock
202 * to nf_conntrack_lock!!! -HW */
204 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
205 if (l4proto
&& l4proto
->destroy
)
206 l4proto
->destroy(ct
);
210 spin_lock_bh(&nf_conntrack_lock
);
211 /* Expectations will have been removed in clean_from_lists,
212 * except TFTP can create an expectation on the first packet,
213 * before connection is in the list, so we need to clean here,
215 nf_ct_remove_expectations(ct
);
217 /* We overload first tuple to link into unconfirmed list. */
218 if (!nf_ct_is_confirmed(ct
)) {
219 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
220 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
223 NF_CT_STAT_INC(net
, delete);
224 spin_unlock_bh(&nf_conntrack_lock
);
227 nf_ct_put(ct
->master
);
229 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
230 nf_conntrack_free(ct
);
233 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
235 struct net
*net
= nf_ct_net(ct
);
237 nf_ct_helper_destroy(ct
);
238 spin_lock_bh(&nf_conntrack_lock
);
239 /* Inside lock so preempt is disabled on module removal path.
240 * Otherwise we can get spurious warnings. */
241 NF_CT_STAT_INC(net
, delete_list
);
242 clean_from_lists(ct
);
243 spin_unlock_bh(&nf_conntrack_lock
);
245 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
247 static void death_by_event(unsigned long ul_conntrack
)
249 struct nf_conn
*ct
= (void *)ul_conntrack
;
250 struct net
*net
= nf_ct_net(ct
);
252 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
253 /* bad luck, let's retry again */
254 ct
->timeout
.expires
= jiffies
+
255 (random32() % net
->ct
.sysctl_events_retry_timeout
);
256 add_timer(&ct
->timeout
);
259 /* we've got the event delivered, now it's dying */
260 set_bit(IPS_DYING_BIT
, &ct
->status
);
261 spin_lock(&nf_conntrack_lock
);
262 hlist_nulls_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
263 spin_unlock(&nf_conntrack_lock
);
267 void nf_ct_insert_dying_list(struct nf_conn
*ct
)
269 struct net
*net
= nf_ct_net(ct
);
271 /* add this conntrack to the dying list */
272 spin_lock_bh(&nf_conntrack_lock
);
273 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
275 spin_unlock_bh(&nf_conntrack_lock
);
276 /* set a new timer to retry event delivery */
277 setup_timer(&ct
->timeout
, death_by_event
, (unsigned long)ct
);
278 ct
->timeout
.expires
= jiffies
+
279 (random32() % net
->ct
.sysctl_events_retry_timeout
);
280 add_timer(&ct
->timeout
);
282 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list
);
284 static void death_by_timeout(unsigned long ul_conntrack
)
286 struct nf_conn
*ct
= (void *)ul_conntrack
;
287 struct nf_conn_tstamp
*tstamp
;
289 tstamp
= nf_conn_tstamp_find(ct
);
290 if (tstamp
&& tstamp
->stop
== 0)
291 tstamp
->stop
= ktime_to_ns(ktime_get_real());
293 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
294 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
295 /* destroy event was not delivered */
296 nf_ct_delete_from_lists(ct
);
297 nf_ct_insert_dying_list(ct
);
300 set_bit(IPS_DYING_BIT
, &ct
->status
);
301 nf_ct_delete_from_lists(ct
);
307 * - Caller must take a reference on returned object
308 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
310 * - Caller must lock nf_conntrack_lock before calling this function
312 static struct nf_conntrack_tuple_hash
*
313 ____nf_conntrack_find(struct net
*net
, u16 zone
,
314 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
316 struct nf_conntrack_tuple_hash
*h
;
317 struct hlist_nulls_node
*n
;
318 unsigned int bucket
= hash_bucket(hash
, net
);
320 /* Disable BHs the entire time since we normally need to disable them
321 * at least once for the stats anyway.
325 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
326 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
327 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
328 NF_CT_STAT_INC(net
, found
);
332 NF_CT_STAT_INC(net
, searched
);
335 * if the nulls value we got at the end of this lookup is
336 * not the expected one, we must restart lookup.
337 * We probably met an item that was moved to another chain.
339 if (get_nulls_value(n
) != bucket
) {
340 NF_CT_STAT_INC(net
, search_restart
);
348 struct nf_conntrack_tuple_hash
*
349 __nf_conntrack_find(struct net
*net
, u16 zone
,
350 const struct nf_conntrack_tuple
*tuple
)
352 return ____nf_conntrack_find(net
, zone
, tuple
,
353 hash_conntrack_raw(tuple
, zone
));
355 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
357 /* Find a connection corresponding to a tuple. */
358 static struct nf_conntrack_tuple_hash
*
359 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
360 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
362 struct nf_conntrack_tuple_hash
*h
;
367 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
369 ct
= nf_ct_tuplehash_to_ctrack(h
);
370 if (unlikely(nf_ct_is_dying(ct
) ||
371 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
374 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
375 nf_ct_zone(ct
) != zone
)) {
386 struct nf_conntrack_tuple_hash
*
387 nf_conntrack_find_get(struct net
*net
, u16 zone
,
388 const struct nf_conntrack_tuple
*tuple
)
390 return __nf_conntrack_find_get(net
, zone
, tuple
,
391 hash_conntrack_raw(tuple
, zone
));
393 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
395 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
397 unsigned int repl_hash
)
399 struct net
*net
= nf_ct_net(ct
);
401 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
402 &net
->ct
.hash
[hash
]);
403 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
404 &net
->ct
.hash
[repl_hash
]);
408 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
410 struct net
*net
= nf_ct_net(ct
);
411 unsigned int hash
, repl_hash
;
412 struct nf_conntrack_tuple_hash
*h
;
413 struct hlist_nulls_node
*n
;
416 zone
= nf_ct_zone(ct
);
417 hash
= hash_conntrack(net
, zone
,
418 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
419 repl_hash
= hash_conntrack(net
, zone
,
420 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
422 spin_lock_bh(&nf_conntrack_lock
);
424 /* See if there's one in the list already, including reverse */
425 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
426 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
428 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
430 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
431 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
433 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
436 add_timer(&ct
->timeout
);
437 nf_conntrack_get(&ct
->ct_general
);
438 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
439 NF_CT_STAT_INC(net
, insert
);
440 spin_unlock_bh(&nf_conntrack_lock
);
445 NF_CT_STAT_INC(net
, insert_failed
);
446 spin_unlock_bh(&nf_conntrack_lock
);
449 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
451 /* Confirm a connection given skb; places it in hash table */
453 __nf_conntrack_confirm(struct sk_buff
*skb
)
455 unsigned int hash
, repl_hash
;
456 struct nf_conntrack_tuple_hash
*h
;
458 struct nf_conn_help
*help
;
459 struct nf_conn_tstamp
*tstamp
;
460 struct hlist_nulls_node
*n
;
461 enum ip_conntrack_info ctinfo
;
465 ct
= nf_ct_get(skb
, &ctinfo
);
468 /* ipt_REJECT uses nf_conntrack_attach to attach related
469 ICMP/TCP RST packets in other direction. Actual packet
470 which created connection will be IP_CT_NEW or for an
471 expected connection, IP_CT_RELATED. */
472 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
475 zone
= nf_ct_zone(ct
);
476 /* reuse the hash saved before */
477 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
478 hash
= hash_bucket(hash
, net
);
479 repl_hash
= hash_conntrack(net
, zone
,
480 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
482 /* We're not in hash table, and we refuse to set up related
483 connections for unconfirmed conns. But packet copies and
484 REJECT will give spurious warnings here. */
485 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
487 /* No external references means no one else could have
489 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
490 pr_debug("Confirming conntrack %p\n", ct
);
492 spin_lock_bh(&nf_conntrack_lock
);
494 /* We have to check the DYING flag inside the lock to prevent
495 a race against nf_ct_get_next_corpse() possibly called from
496 user context, else we insert an already 'dead' hash, blocking
497 further use of that particular connection -JM */
499 if (unlikely(nf_ct_is_dying(ct
))) {
500 spin_unlock_bh(&nf_conntrack_lock
);
504 /* See if there's one in the list already, including reverse:
505 NAT could have grabbed it without realizing, since we're
506 not in the hash. If there is, we lost race. */
507 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
508 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
510 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
512 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
513 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
515 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
518 /* Remove from unconfirmed list */
519 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
521 /* Timer relative to confirmation time, not original
522 setting time, otherwise we'd get timer wrap in
523 weird delay cases. */
524 ct
->timeout
.expires
+= jiffies
;
525 add_timer(&ct
->timeout
);
526 atomic_inc(&ct
->ct_general
.use
);
527 ct
->status
|= IPS_CONFIRMED
;
529 /* set conntrack timestamp, if enabled. */
530 tstamp
= nf_conn_tstamp_find(ct
);
532 if (skb
->tstamp
.tv64
== 0)
533 __net_timestamp((struct sk_buff
*)skb
);
535 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
537 /* Since the lookup is lockless, hash insertion must be done after
538 * starting the timer and setting the CONFIRMED bit. The RCU barriers
539 * guarantee that no other CPU can find the conntrack before the above
540 * stores are visible.
542 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
543 NF_CT_STAT_INC(net
, insert
);
544 spin_unlock_bh(&nf_conntrack_lock
);
546 help
= nfct_help(ct
);
547 if (help
&& help
->helper
)
548 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
550 nf_conntrack_event_cache(master_ct(ct
) ?
551 IPCT_RELATED
: IPCT_NEW
, ct
);
555 NF_CT_STAT_INC(net
, insert_failed
);
556 spin_unlock_bh(&nf_conntrack_lock
);
559 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
561 /* Returns true if a connection correspondings to the tuple (required
564 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
565 const struct nf_conn
*ignored_conntrack
)
567 struct net
*net
= nf_ct_net(ignored_conntrack
);
568 struct nf_conntrack_tuple_hash
*h
;
569 struct hlist_nulls_node
*n
;
571 u16 zone
= nf_ct_zone(ignored_conntrack
);
572 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
574 /* Disable BHs the entire time since we need to disable them at
575 * least once for the stats anyway.
578 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
579 ct
= nf_ct_tuplehash_to_ctrack(h
);
580 if (ct
!= ignored_conntrack
&&
581 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
582 nf_ct_zone(ct
) == zone
) {
583 NF_CT_STAT_INC(net
, found
);
584 rcu_read_unlock_bh();
587 NF_CT_STAT_INC(net
, searched
);
589 rcu_read_unlock_bh();
593 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
595 #define NF_CT_EVICTION_RANGE 8
597 /* There's a small race here where we may free a just-assured
598 connection. Too bad: we're in trouble anyway. */
599 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
601 /* Use oldest entry, which is roughly LRU */
602 struct nf_conntrack_tuple_hash
*h
;
603 struct nf_conn
*ct
= NULL
, *tmp
;
604 struct hlist_nulls_node
*n
;
605 unsigned int i
, cnt
= 0;
609 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
610 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
612 tmp
= nf_ct_tuplehash_to_ctrack(h
);
613 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
619 if (likely(!nf_ct_is_dying(ct
) &&
620 atomic_inc_not_zero(&ct
->ct_general
.use
)))
626 if (cnt
>= NF_CT_EVICTION_RANGE
)
629 hash
= (hash
+ 1) % net
->ct
.htable_size
;
636 if (del_timer(&ct
->timeout
)) {
637 death_by_timeout((unsigned long)ct
);
639 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
645 void init_nf_conntrack_hash_rnd(void)
650 * Why not initialize nf_conntrack_rnd in a "init()" function ?
651 * Because there isn't enough entropy when system initializing,
652 * and we initialize it as late as possible.
655 get_random_bytes(&rand
, sizeof(rand
));
657 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
660 static struct nf_conn
*
661 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
662 const struct nf_conntrack_tuple
*orig
,
663 const struct nf_conntrack_tuple
*repl
,
668 if (unlikely(!nf_conntrack_hash_rnd
)) {
669 init_nf_conntrack_hash_rnd();
670 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
671 hash
= hash_conntrack_raw(orig
, zone
);
674 /* We don't want any race condition at early drop stage */
675 atomic_inc(&net
->ct
.count
);
677 if (nf_conntrack_max
&&
678 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
679 if (!early_drop(net
, hash_bucket(hash
, net
))) {
680 atomic_dec(&net
->ct
.count
);
683 "nf_conntrack: table full, dropping"
685 return ERR_PTR(-ENOMEM
);
690 * Do not use kmem_cache_zalloc(), as this cache uses
691 * SLAB_DESTROY_BY_RCU.
693 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
695 atomic_dec(&net
->ct
.count
);
696 return ERR_PTR(-ENOMEM
);
699 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
700 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
702 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
703 offsetof(struct nf_conn
, proto
) -
704 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
705 spin_lock_init(&ct
->lock
);
706 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
707 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
708 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
709 /* save hash for reusing when confirming */
710 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
711 /* Don't set timer yet: wait for confirmation */
712 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
713 write_pnet(&ct
->ct_net
, net
);
714 #ifdef CONFIG_NF_CONNTRACK_ZONES
716 struct nf_conntrack_zone
*nf_ct_zone
;
718 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
721 nf_ct_zone
->id
= zone
;
725 * changes to lookup keys must be done before setting refcnt to 1
728 atomic_set(&ct
->ct_general
.use
, 1);
731 #ifdef CONFIG_NF_CONNTRACK_ZONES
733 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
734 return ERR_PTR(-ENOMEM
);
738 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
739 const struct nf_conntrack_tuple
*orig
,
740 const struct nf_conntrack_tuple
*repl
,
743 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
745 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
747 void nf_conntrack_free(struct nf_conn
*ct
)
749 struct net
*net
= nf_ct_net(ct
);
751 nf_ct_ext_destroy(ct
);
752 atomic_dec(&net
->ct
.count
);
754 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
756 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
758 /* Allocate a new conntrack: we return -ENOMEM if classification
759 failed due to stress. Otherwise it really is unclassifiable. */
760 static struct nf_conntrack_tuple_hash
*
761 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
762 const struct nf_conntrack_tuple
*tuple
,
763 struct nf_conntrack_l3proto
*l3proto
,
764 struct nf_conntrack_l4proto
*l4proto
,
766 unsigned int dataoff
, u32 hash
)
769 struct nf_conn_help
*help
;
770 struct nf_conntrack_tuple repl_tuple
;
771 struct nf_conntrack_ecache
*ecache
;
772 struct nf_conntrack_expect
*exp
;
773 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
775 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
776 pr_debug("Can't invert tuple.\n");
780 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
783 return (struct nf_conntrack_tuple_hash
*)ct
;
785 if (!l4proto
->new(ct
, skb
, dataoff
)) {
786 nf_conntrack_free(ct
);
787 pr_debug("init conntrack: can't track with proto module\n");
791 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
792 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
794 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
795 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
796 ecache
? ecache
->expmask
: 0,
799 spin_lock_bh(&nf_conntrack_lock
);
800 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
802 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
804 /* Welcome, Mr. Bond. We've been expecting you... */
805 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
806 ct
->master
= exp
->master
;
808 help
= nf_ct_helper_ext_add(ct
, GFP_ATOMIC
);
810 rcu_assign_pointer(help
->helper
, exp
->helper
);
813 #ifdef CONFIG_NF_CONNTRACK_MARK
814 ct
->mark
= exp
->master
->mark
;
816 #ifdef CONFIG_NF_CONNTRACK_SECMARK
817 ct
->secmark
= exp
->master
->secmark
;
819 nf_conntrack_get(&ct
->master
->ct_general
);
820 NF_CT_STAT_INC(net
, expect_new
);
822 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
823 NF_CT_STAT_INC(net
, new);
826 /* Overload tuple linked list to put us in unconfirmed list. */
827 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
828 &net
->ct
.unconfirmed
);
830 spin_unlock_bh(&nf_conntrack_lock
);
834 exp
->expectfn(ct
, exp
);
835 nf_ct_expect_put(exp
);
838 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
841 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
842 static inline struct nf_conn
*
843 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
845 unsigned int dataoff
,
848 struct nf_conntrack_l3proto
*l3proto
,
849 struct nf_conntrack_l4proto
*l4proto
,
851 enum ip_conntrack_info
*ctinfo
)
853 struct nf_conntrack_tuple tuple
;
854 struct nf_conntrack_tuple_hash
*h
;
856 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
859 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
860 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
862 pr_debug("resolve_normal_ct: Can't get tuple\n");
866 /* look for tuple match */
867 hash
= hash_conntrack_raw(&tuple
, zone
);
868 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
870 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
877 ct
= nf_ct_tuplehash_to_ctrack(h
);
879 /* It exists; we have (non-exclusive) reference. */
880 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
881 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
882 /* Please set reply bit if this packet OK */
885 /* Once we've had two way comms, always ESTABLISHED. */
886 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
887 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
888 *ctinfo
= IP_CT_ESTABLISHED
;
889 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
890 pr_debug("nf_conntrack_in: related packet for %p\n",
892 *ctinfo
= IP_CT_RELATED
;
894 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
899 skb
->nfct
= &ct
->ct_general
;
900 skb
->nfctinfo
= *ctinfo
;
905 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
908 struct nf_conn
*ct
, *tmpl
= NULL
;
909 enum ip_conntrack_info ctinfo
;
910 struct nf_conntrack_l3proto
*l3proto
;
911 struct nf_conntrack_l4proto
*l4proto
;
912 unsigned int dataoff
;
918 /* Previously seen (loopback or untracked)? Ignore. */
919 tmpl
= (struct nf_conn
*)skb
->nfct
;
920 if (!nf_ct_is_template(tmpl
)) {
921 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
927 /* rcu_read_lock()ed by nf_hook_slow */
928 l3proto
= __nf_ct_l3proto_find(pf
);
929 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
930 &dataoff
, &protonum
);
932 pr_debug("not prepared to track yet or error occurred\n");
933 NF_CT_STAT_INC_ATOMIC(net
, error
);
934 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
939 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
941 /* It may be an special packet, error, unclean...
942 * inverse of the return code tells to the netfilter
943 * core what to do with the packet. */
944 if (l4proto
->error
!= NULL
) {
945 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
948 NF_CT_STAT_INC_ATOMIC(net
, error
);
949 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
953 /* ICMP[v6] protocol trackers may assign one conntrack. */
958 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
959 l3proto
, l4proto
, &set_reply
, &ctinfo
);
961 /* Not valid part of a connection */
962 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
968 /* Too stressed to deal. */
969 NF_CT_STAT_INC_ATOMIC(net
, drop
);
974 NF_CT_ASSERT(skb
->nfct
);
976 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
);
978 /* Invalid: inverse of the return code tells
979 * the netfilter core what to do */
980 pr_debug("nf_conntrack_in: Can't track with proto module\n");
981 nf_conntrack_put(skb
->nfct
);
983 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
985 NF_CT_STAT_INC_ATOMIC(net
, drop
);
990 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
991 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
994 /* Special case: we have to repeat this hook, assign the
995 * template again to this packet. We assume that this packet
996 * has no conntrack assigned. This is used by nf_ct_tcp. */
997 if (ret
== NF_REPEAT
)
998 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1005 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1007 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1008 const struct nf_conntrack_tuple
*orig
)
1013 ret
= nf_ct_invert_tuple(inverse
, orig
,
1014 __nf_ct_l3proto_find(orig
->src
.l3num
),
1015 __nf_ct_l4proto_find(orig
->src
.l3num
,
1016 orig
->dst
.protonum
));
1020 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1022 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1023 implicitly racy: see __nf_conntrack_confirm */
1024 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1025 const struct nf_conntrack_tuple
*newreply
)
1027 struct nf_conn_help
*help
= nfct_help(ct
);
1029 /* Should be unconfirmed, so not in hash table yet */
1030 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1032 pr_debug("Altering reply tuple of %p to ", ct
);
1033 nf_ct_dump_tuple(newreply
);
1035 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1036 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1040 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1043 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1045 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1046 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1047 enum ip_conntrack_info ctinfo
,
1048 const struct sk_buff
*skb
,
1049 unsigned long extra_jiffies
,
1052 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1055 /* Only update if this is not a fixed timeout */
1056 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1059 /* If not in hash table, timer will not be active yet */
1060 if (!nf_ct_is_confirmed(ct
)) {
1061 ct
->timeout
.expires
= extra_jiffies
;
1063 unsigned long newtime
= jiffies
+ extra_jiffies
;
1065 /* Only update the timeout if the new timeout is at least
1066 HZ jiffies from the old timeout. Need del_timer for race
1067 avoidance (may already be dying). */
1068 if (newtime
- ct
->timeout
.expires
>= HZ
)
1069 mod_timer_pending(&ct
->timeout
, newtime
);
1074 struct nf_conn_counter
*acct
;
1076 acct
= nf_conn_acct_find(ct
);
1078 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1079 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1083 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1085 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1086 enum ip_conntrack_info ctinfo
,
1087 const struct sk_buff
*skb
,
1091 struct nf_conn_counter
*acct
;
1093 acct
= nf_conn_acct_find(ct
);
1095 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1096 atomic64_add(skb
->len
- skb_network_offset(skb
),
1097 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1101 if (del_timer(&ct
->timeout
)) {
1102 ct
->timeout
.function((unsigned long)ct
);
1107 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1109 #ifdef CONFIG_NF_CONNTRACK_ZONES
1110 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1111 .len
= sizeof(struct nf_conntrack_zone
),
1112 .align
= __alignof__(struct nf_conntrack_zone
),
1113 .id
= NF_CT_EXT_ZONE
,
1117 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1119 #include <linux/netfilter/nfnetlink.h>
1120 #include <linux/netfilter/nfnetlink_conntrack.h>
1121 #include <linux/mutex.h>
1123 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1124 * in ip_conntrack_core, since we don't want the protocols to autoload
1125 * or depend on ctnetlink */
1126 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1127 const struct nf_conntrack_tuple
*tuple
)
1129 NLA_PUT_BE16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
);
1130 NLA_PUT_BE16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
);
1136 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1138 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1139 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1140 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1142 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1144 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1145 struct nf_conntrack_tuple
*t
)
1147 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1150 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1151 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1155 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1157 int nf_ct_port_nlattr_tuple_size(void)
1159 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1161 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1164 /* Used by ipt_REJECT and ip6t_REJECT. */
1165 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1168 enum ip_conntrack_info ctinfo
;
1170 /* This ICMP is in reverse direction to the packet which caused it */
1171 ct
= nf_ct_get(skb
, &ctinfo
);
1172 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1173 ctinfo
= IP_CT_RELATED_REPLY
;
1175 ctinfo
= IP_CT_RELATED
;
1177 /* Attach to new skbuff, and increment count */
1178 nskb
->nfct
= &ct
->ct_general
;
1179 nskb
->nfctinfo
= ctinfo
;
1180 nf_conntrack_get(nskb
->nfct
);
1183 /* Bring out ya dead! */
1184 static struct nf_conn
*
1185 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1186 void *data
, unsigned int *bucket
)
1188 struct nf_conntrack_tuple_hash
*h
;
1190 struct hlist_nulls_node
*n
;
1192 spin_lock_bh(&nf_conntrack_lock
);
1193 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1194 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1195 ct
= nf_ct_tuplehash_to_ctrack(h
);
1200 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1201 ct
= nf_ct_tuplehash_to_ctrack(h
);
1203 set_bit(IPS_DYING_BIT
, &ct
->status
);
1205 spin_unlock_bh(&nf_conntrack_lock
);
1208 atomic_inc(&ct
->ct_general
.use
);
1209 spin_unlock_bh(&nf_conntrack_lock
);
1213 void nf_ct_iterate_cleanup(struct net
*net
,
1214 int (*iter
)(struct nf_conn
*i
, void *data
),
1218 unsigned int bucket
= 0;
1220 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1221 /* Time to push up daises... */
1222 if (del_timer(&ct
->timeout
))
1223 death_by_timeout((unsigned long)ct
);
1224 /* ... else the timer will get him soon. */
1229 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1231 struct __nf_ct_flush_report
{
1236 static int kill_report(struct nf_conn
*i
, void *data
)
1238 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1239 struct nf_conn_tstamp
*tstamp
;
1241 tstamp
= nf_conn_tstamp_find(i
);
1242 if (tstamp
&& tstamp
->stop
== 0)
1243 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1245 /* If we fail to deliver the event, death_by_timeout() will retry */
1246 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1247 fr
->pid
, fr
->report
) < 0)
1250 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1251 set_bit(IPS_DYING_BIT
, &i
->status
);
1255 static int kill_all(struct nf_conn
*i
, void *data
)
1260 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1262 if (is_vmalloc_addr(hash
))
1265 free_pages((unsigned long)hash
,
1266 get_order(sizeof(struct hlist_head
) * size
));
1268 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1270 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1272 struct __nf_ct_flush_report fr
= {
1276 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1278 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1280 static void nf_ct_release_dying_list(struct net
*net
)
1282 struct nf_conntrack_tuple_hash
*h
;
1284 struct hlist_nulls_node
*n
;
1286 spin_lock_bh(&nf_conntrack_lock
);
1287 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1288 ct
= nf_ct_tuplehash_to_ctrack(h
);
1289 /* never fails to remove them, no listeners at this point */
1292 spin_unlock_bh(&nf_conntrack_lock
);
1295 static int untrack_refs(void)
1299 for_each_possible_cpu(cpu
) {
1300 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1302 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1307 static void nf_conntrack_cleanup_init_net(void)
1309 while (untrack_refs() > 0)
1312 nf_conntrack_helper_fini();
1313 nf_conntrack_proto_fini();
1314 #ifdef CONFIG_NF_CONNTRACK_ZONES
1315 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1319 static void nf_conntrack_cleanup_net(struct net
*net
)
1322 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1323 nf_ct_release_dying_list(net
);
1324 if (atomic_read(&net
->ct
.count
) != 0) {
1326 goto i_see_dead_people
;
1329 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1330 nf_conntrack_ecache_fini(net
);
1331 nf_conntrack_tstamp_fini(net
);
1332 nf_conntrack_acct_fini(net
);
1333 nf_conntrack_expect_fini(net
);
1334 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1335 kfree(net
->ct
.slabname
);
1336 free_percpu(net
->ct
.stat
);
1339 /* Mishearing the voices in his head, our hero wonders how he's
1340 supposed to kill the mall. */
1341 void nf_conntrack_cleanup(struct net
*net
)
1343 if (net_eq(net
, &init_net
))
1344 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1346 /* This makes sure all current packets have passed through
1347 netfilter framework. Roll on, two-stage module
1351 nf_conntrack_cleanup_net(net
);
1353 if (net_eq(net
, &init_net
)) {
1354 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1355 nf_conntrack_cleanup_init_net();
1359 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1361 struct hlist_nulls_head
*hash
;
1362 unsigned int nr_slots
, i
;
1365 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1366 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1367 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1368 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1371 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1376 for (i
= 0; i
< nr_slots
; i
++)
1377 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1381 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1383 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1386 unsigned int hashsize
, old_size
;
1387 struct hlist_nulls_head
*hash
, *old_hash
;
1388 struct nf_conntrack_tuple_hash
*h
;
1391 if (current
->nsproxy
->net_ns
!= &init_net
)
1394 /* On boot, we can set this without any fancy locking. */
1395 if (!nf_conntrack_htable_size
)
1396 return param_set_uint(val
, kp
);
1398 hashsize
= simple_strtoul(val
, NULL
, 0);
1402 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1406 /* Lookups in the old hash might happen in parallel, which means we
1407 * might get false negatives during connection lookup. New connections
1408 * created because of a false negative won't make it into the hash
1409 * though since that required taking the lock.
1411 spin_lock_bh(&nf_conntrack_lock
);
1412 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1413 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1414 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1415 struct nf_conntrack_tuple_hash
, hnnode
);
1416 ct
= nf_ct_tuplehash_to_ctrack(h
);
1417 hlist_nulls_del_rcu(&h
->hnnode
);
1418 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1420 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1423 old_size
= init_net
.ct
.htable_size
;
1424 old_hash
= init_net
.ct
.hash
;
1426 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1427 init_net
.ct
.hash
= hash
;
1428 spin_unlock_bh(&nf_conntrack_lock
);
1430 nf_ct_free_hashtable(old_hash
, old_size
);
1433 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1435 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1436 &nf_conntrack_htable_size
, 0600);
1438 void nf_ct_untracked_status_or(unsigned long bits
)
1442 for_each_possible_cpu(cpu
)
1443 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1445 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1447 static int nf_conntrack_init_init_net(void)
1452 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1453 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1454 if (!nf_conntrack_htable_size
) {
1455 nf_conntrack_htable_size
1456 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1457 / sizeof(struct hlist_head
));
1458 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1459 nf_conntrack_htable_size
= 16384;
1460 if (nf_conntrack_htable_size
< 32)
1461 nf_conntrack_htable_size
= 32;
1463 /* Use a max. factor of four by default to get the same max as
1464 * with the old struct list_heads. When a table size is given
1465 * we use the old value of 8 to avoid reducing the max.
1469 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1471 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1472 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1475 ret
= nf_conntrack_proto_init();
1479 ret
= nf_conntrack_helper_init();
1483 #ifdef CONFIG_NF_CONNTRACK_ZONES
1484 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1488 /* Set up fake conntrack: to never be deleted, not in any hashes */
1489 for_each_possible_cpu(cpu
) {
1490 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1491 write_pnet(&ct
->ct_net
, &init_net
);
1492 atomic_set(&ct
->ct_general
.use
, 1);
1494 /* - and look it like as a confirmed connection */
1495 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1498 #ifdef CONFIG_NF_CONNTRACK_ZONES
1500 nf_conntrack_helper_fini();
1503 nf_conntrack_proto_fini();
1509 * We need to use special "null" values, not used in hash table
1511 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1512 #define DYING_NULLS_VAL ((1<<30)+1)
1514 static int nf_conntrack_init_net(struct net
*net
)
1518 atomic_set(&net
->ct
.count
, 0);
1519 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1520 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1521 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1522 if (!net
->ct
.stat
) {
1527 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1528 if (!net
->ct
.slabname
) {
1533 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1534 sizeof(struct nf_conn
), 0,
1535 SLAB_DESTROY_BY_RCU
, NULL
);
1536 if (!net
->ct
.nf_conntrack_cachep
) {
1537 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1542 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1543 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1544 if (!net
->ct
.hash
) {
1546 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1549 ret
= nf_conntrack_expect_init(net
);
1552 ret
= nf_conntrack_acct_init(net
);
1555 ret
= nf_conntrack_tstamp_init(net
);
1558 ret
= nf_conntrack_ecache_init(net
);
1565 nf_conntrack_tstamp_fini(net
);
1567 nf_conntrack_acct_fini(net
);
1569 nf_conntrack_expect_fini(net
);
1571 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1573 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1575 kfree(net
->ct
.slabname
);
1577 free_percpu(net
->ct
.stat
);
1582 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1583 enum ip_conntrack_dir dir
,
1585 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1587 int nf_conntrack_init(struct net
*net
)
1591 if (net_eq(net
, &init_net
)) {
1592 ret
= nf_conntrack_init_init_net();
1596 ret
= nf_conntrack_init_net(net
);
1600 if (net_eq(net
, &init_net
)) {
1601 /* For use by REJECT target */
1602 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1603 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1605 /* Howto get NAT offsets */
1606 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1611 if (net_eq(net
, &init_net
))
1612 nf_conntrack_cleanup_init_net();