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_conntrack_timeout.h>
48 #include <net/netfilter/nf_nat.h>
49 #include <net/netfilter/nf_nat_core.h>
51 #define NF_CONNTRACK_VERSION "0.5.0"
53 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
54 enum nf_nat_manip_type manip
,
55 const struct nlattr
*attr
) __read_mostly
;
56 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
58 DEFINE_SPINLOCK(nf_conntrack_lock
);
59 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
61 unsigned int nf_conntrack_htable_size __read_mostly
;
62 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
64 unsigned int nf_conntrack_max __read_mostly
;
65 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
67 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
68 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
70 unsigned int nf_conntrack_hash_rnd __read_mostly
;
71 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
73 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
77 /* The direction must be ignored, so we hash everything up to the
78 * destination ports (which is a multiple of 4) and treat the last
79 * three bytes manually.
81 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
82 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
83 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
84 tuple
->dst
.protonum
));
87 static u32
__hash_bucket(u32 hash
, unsigned int size
)
89 return ((u64
)hash
* size
) >> 32;
92 static u32
hash_bucket(u32 hash
, const struct net
*net
)
94 return __hash_bucket(hash
, net
->ct
.htable_size
);
97 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
98 u16 zone
, unsigned int size
)
100 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
103 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
104 const struct nf_conntrack_tuple
*tuple
)
106 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
110 nf_ct_get_tuple(const struct sk_buff
*skb
,
112 unsigned int dataoff
,
115 struct nf_conntrack_tuple
*tuple
,
116 const struct nf_conntrack_l3proto
*l3proto
,
117 const struct nf_conntrack_l4proto
*l4proto
)
119 memset(tuple
, 0, sizeof(*tuple
));
121 tuple
->src
.l3num
= l3num
;
122 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
125 tuple
->dst
.protonum
= protonum
;
126 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
128 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
130 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
132 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
133 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
135 struct nf_conntrack_l3proto
*l3proto
;
136 struct nf_conntrack_l4proto
*l4proto
;
137 unsigned int protoff
;
143 l3proto
= __nf_ct_l3proto_find(l3num
);
144 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
145 if (ret
!= NF_ACCEPT
) {
150 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
152 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
158 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
161 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
162 const struct nf_conntrack_tuple
*orig
,
163 const struct nf_conntrack_l3proto
*l3proto
,
164 const struct nf_conntrack_l4proto
*l4proto
)
166 memset(inverse
, 0, sizeof(*inverse
));
168 inverse
->src
.l3num
= orig
->src
.l3num
;
169 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
172 inverse
->dst
.dir
= !orig
->dst
.dir
;
174 inverse
->dst
.protonum
= orig
->dst
.protonum
;
175 return l4proto
->invert_tuple(inverse
, orig
);
177 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
180 clean_from_lists(struct nf_conn
*ct
)
182 pr_debug("clean_from_lists(%p)\n", ct
);
183 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
184 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
186 /* Destroy all pending expectations */
187 nf_ct_remove_expectations(ct
);
191 destroy_conntrack(struct nf_conntrack
*nfct
)
193 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
194 struct net
*net
= nf_ct_net(ct
);
195 struct nf_conntrack_l4proto
*l4proto
;
197 pr_debug("destroy_conntrack(%p)\n", ct
);
198 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
199 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
201 /* To make sure we don't get any weird locking issues here:
202 * destroy_conntrack() MUST NOT be called with a write lock
203 * to nf_conntrack_lock!!! -HW */
205 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
206 if (l4proto
&& l4proto
->destroy
)
207 l4proto
->destroy(ct
);
211 spin_lock_bh(&nf_conntrack_lock
);
212 /* Expectations will have been removed in clean_from_lists,
213 * except TFTP can create an expectation on the first packet,
214 * before connection is in the list, so we need to clean here,
216 nf_ct_remove_expectations(ct
);
218 /* We overload first tuple to link into unconfirmed list. */
219 if (!nf_ct_is_confirmed(ct
)) {
220 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
221 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
224 NF_CT_STAT_INC(net
, delete);
225 spin_unlock_bh(&nf_conntrack_lock
);
228 nf_ct_put(ct
->master
);
230 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
231 nf_conntrack_free(ct
);
234 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
236 struct net
*net
= nf_ct_net(ct
);
238 nf_ct_helper_destroy(ct
);
239 spin_lock_bh(&nf_conntrack_lock
);
240 /* Inside lock so preempt is disabled on module removal path.
241 * Otherwise we can get spurious warnings. */
242 NF_CT_STAT_INC(net
, delete_list
);
243 clean_from_lists(ct
);
244 spin_unlock_bh(&nf_conntrack_lock
);
246 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
248 static void death_by_event(unsigned long ul_conntrack
)
250 struct nf_conn
*ct
= (void *)ul_conntrack
;
251 struct net
*net
= nf_ct_net(ct
);
252 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
254 BUG_ON(ecache
== NULL
);
256 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
257 /* bad luck, let's retry again */
258 ecache
->timeout
.expires
= jiffies
+
259 (random32() % net
->ct
.sysctl_events_retry_timeout
);
260 add_timer(&ecache
->timeout
);
263 /* we've got the event delivered, now it's dying */
264 set_bit(IPS_DYING_BIT
, &ct
->status
);
265 spin_lock(&nf_conntrack_lock
);
266 hlist_nulls_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
267 spin_unlock(&nf_conntrack_lock
);
271 void nf_ct_insert_dying_list(struct nf_conn
*ct
)
273 struct net
*net
= nf_ct_net(ct
);
274 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
276 BUG_ON(ecache
== NULL
);
278 /* add this conntrack to the dying list */
279 spin_lock_bh(&nf_conntrack_lock
);
280 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
282 spin_unlock_bh(&nf_conntrack_lock
);
283 /* set a new timer to retry event delivery */
284 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
285 ecache
->timeout
.expires
= jiffies
+
286 (random32() % net
->ct
.sysctl_events_retry_timeout
);
287 add_timer(&ecache
->timeout
);
289 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list
);
291 static void death_by_timeout(unsigned long ul_conntrack
)
293 struct nf_conn
*ct
= (void *)ul_conntrack
;
294 struct nf_conn_tstamp
*tstamp
;
296 tstamp
= nf_conn_tstamp_find(ct
);
297 if (tstamp
&& tstamp
->stop
== 0)
298 tstamp
->stop
= ktime_to_ns(ktime_get_real());
300 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
301 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
302 /* destroy event was not delivered */
303 nf_ct_delete_from_lists(ct
);
304 nf_ct_insert_dying_list(ct
);
307 set_bit(IPS_DYING_BIT
, &ct
->status
);
308 nf_ct_delete_from_lists(ct
);
314 * - Caller must take a reference on returned object
315 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
317 * - Caller must lock nf_conntrack_lock before calling this function
319 static struct nf_conntrack_tuple_hash
*
320 ____nf_conntrack_find(struct net
*net
, u16 zone
,
321 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
323 struct nf_conntrack_tuple_hash
*h
;
324 struct hlist_nulls_node
*n
;
325 unsigned int bucket
= hash_bucket(hash
, net
);
327 /* Disable BHs the entire time since we normally need to disable them
328 * at least once for the stats anyway.
332 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
333 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
334 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
335 NF_CT_STAT_INC(net
, found
);
339 NF_CT_STAT_INC(net
, searched
);
342 * if the nulls value we got at the end of this lookup is
343 * not the expected one, we must restart lookup.
344 * We probably met an item that was moved to another chain.
346 if (get_nulls_value(n
) != bucket
) {
347 NF_CT_STAT_INC(net
, search_restart
);
355 struct nf_conntrack_tuple_hash
*
356 __nf_conntrack_find(struct net
*net
, u16 zone
,
357 const struct nf_conntrack_tuple
*tuple
)
359 return ____nf_conntrack_find(net
, zone
, tuple
,
360 hash_conntrack_raw(tuple
, zone
));
362 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
364 /* Find a connection corresponding to a tuple. */
365 static struct nf_conntrack_tuple_hash
*
366 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
367 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
369 struct nf_conntrack_tuple_hash
*h
;
374 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
376 ct
= nf_ct_tuplehash_to_ctrack(h
);
377 if (unlikely(nf_ct_is_dying(ct
) ||
378 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
381 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
382 nf_ct_zone(ct
) != zone
)) {
393 struct nf_conntrack_tuple_hash
*
394 nf_conntrack_find_get(struct net
*net
, u16 zone
,
395 const struct nf_conntrack_tuple
*tuple
)
397 return __nf_conntrack_find_get(net
, zone
, tuple
,
398 hash_conntrack_raw(tuple
, zone
));
400 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
402 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
404 unsigned int repl_hash
)
406 struct net
*net
= nf_ct_net(ct
);
408 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
409 &net
->ct
.hash
[hash
]);
410 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
411 &net
->ct
.hash
[repl_hash
]);
415 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
417 struct net
*net
= nf_ct_net(ct
);
418 unsigned int hash
, repl_hash
;
419 struct nf_conntrack_tuple_hash
*h
;
420 struct hlist_nulls_node
*n
;
423 zone
= nf_ct_zone(ct
);
424 hash
= hash_conntrack(net
, zone
,
425 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
426 repl_hash
= hash_conntrack(net
, zone
,
427 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
429 spin_lock_bh(&nf_conntrack_lock
);
431 /* See if there's one in the list already, including reverse */
432 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
433 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
435 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
437 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
438 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
440 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
443 add_timer(&ct
->timeout
);
444 nf_conntrack_get(&ct
->ct_general
);
445 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
446 NF_CT_STAT_INC(net
, insert
);
447 spin_unlock_bh(&nf_conntrack_lock
);
452 NF_CT_STAT_INC(net
, insert_failed
);
453 spin_unlock_bh(&nf_conntrack_lock
);
456 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
458 /* Confirm a connection given skb; places it in hash table */
460 __nf_conntrack_confirm(struct sk_buff
*skb
)
462 unsigned int hash
, repl_hash
;
463 struct nf_conntrack_tuple_hash
*h
;
465 struct nf_conn_help
*help
;
466 struct nf_conn_tstamp
*tstamp
;
467 struct hlist_nulls_node
*n
;
468 enum ip_conntrack_info ctinfo
;
472 ct
= nf_ct_get(skb
, &ctinfo
);
475 /* ipt_REJECT uses nf_conntrack_attach to attach related
476 ICMP/TCP RST packets in other direction. Actual packet
477 which created connection will be IP_CT_NEW or for an
478 expected connection, IP_CT_RELATED. */
479 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
482 zone
= nf_ct_zone(ct
);
483 /* reuse the hash saved before */
484 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
485 hash
= hash_bucket(hash
, net
);
486 repl_hash
= hash_conntrack(net
, zone
,
487 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
489 /* We're not in hash table, and we refuse to set up related
490 connections for unconfirmed conns. But packet copies and
491 REJECT will give spurious warnings here. */
492 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
494 /* No external references means no one else could have
496 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
497 pr_debug("Confirming conntrack %p\n", ct
);
499 spin_lock_bh(&nf_conntrack_lock
);
501 /* We have to check the DYING flag inside the lock to prevent
502 a race against nf_ct_get_next_corpse() possibly called from
503 user context, else we insert an already 'dead' hash, blocking
504 further use of that particular connection -JM */
506 if (unlikely(nf_ct_is_dying(ct
))) {
507 spin_unlock_bh(&nf_conntrack_lock
);
511 /* See if there's one in the list already, including reverse:
512 NAT could have grabbed it without realizing, since we're
513 not in the hash. If there is, we lost race. */
514 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
515 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
517 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
519 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
520 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
522 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
525 /* Remove from unconfirmed list */
526 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
528 /* Timer relative to confirmation time, not original
529 setting time, otherwise we'd get timer wrap in
530 weird delay cases. */
531 ct
->timeout
.expires
+= jiffies
;
532 add_timer(&ct
->timeout
);
533 atomic_inc(&ct
->ct_general
.use
);
534 ct
->status
|= IPS_CONFIRMED
;
536 /* set conntrack timestamp, if enabled. */
537 tstamp
= nf_conn_tstamp_find(ct
);
539 if (skb
->tstamp
.tv64
== 0)
540 __net_timestamp(skb
);
542 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
544 /* Since the lookup is lockless, hash insertion must be done after
545 * starting the timer and setting the CONFIRMED bit. The RCU barriers
546 * guarantee that no other CPU can find the conntrack before the above
547 * stores are visible.
549 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
550 NF_CT_STAT_INC(net
, insert
);
551 spin_unlock_bh(&nf_conntrack_lock
);
553 help
= nfct_help(ct
);
554 if (help
&& help
->helper
)
555 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
557 nf_conntrack_event_cache(master_ct(ct
) ?
558 IPCT_RELATED
: IPCT_NEW
, ct
);
562 NF_CT_STAT_INC(net
, insert_failed
);
563 spin_unlock_bh(&nf_conntrack_lock
);
566 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
568 /* Returns true if a connection correspondings to the tuple (required
571 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
572 const struct nf_conn
*ignored_conntrack
)
574 struct net
*net
= nf_ct_net(ignored_conntrack
);
575 struct nf_conntrack_tuple_hash
*h
;
576 struct hlist_nulls_node
*n
;
578 u16 zone
= nf_ct_zone(ignored_conntrack
);
579 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
581 /* Disable BHs the entire time since we need to disable them at
582 * least once for the stats anyway.
585 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
586 ct
= nf_ct_tuplehash_to_ctrack(h
);
587 if (ct
!= ignored_conntrack
&&
588 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
589 nf_ct_zone(ct
) == zone
) {
590 NF_CT_STAT_INC(net
, found
);
591 rcu_read_unlock_bh();
594 NF_CT_STAT_INC(net
, searched
);
596 rcu_read_unlock_bh();
600 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
602 #define NF_CT_EVICTION_RANGE 8
604 /* There's a small race here where we may free a just-assured
605 connection. Too bad: we're in trouble anyway. */
606 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
608 /* Use oldest entry, which is roughly LRU */
609 struct nf_conntrack_tuple_hash
*h
;
610 struct nf_conn
*ct
= NULL
, *tmp
;
611 struct hlist_nulls_node
*n
;
612 unsigned int i
, cnt
= 0;
616 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
617 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
619 tmp
= nf_ct_tuplehash_to_ctrack(h
);
620 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
626 if (likely(!nf_ct_is_dying(ct
) &&
627 atomic_inc_not_zero(&ct
->ct_general
.use
)))
633 if (cnt
>= NF_CT_EVICTION_RANGE
)
636 hash
= (hash
+ 1) % net
->ct
.htable_size
;
643 if (del_timer(&ct
->timeout
)) {
644 death_by_timeout((unsigned long)ct
);
645 /* Check if we indeed killed this entry. Reliable event
646 delivery may have inserted it into the dying list. */
647 if (test_bit(IPS_DYING_BIT
, &ct
->status
)) {
649 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
656 void init_nf_conntrack_hash_rnd(void)
661 * Why not initialize nf_conntrack_rnd in a "init()" function ?
662 * Because there isn't enough entropy when system initializing,
663 * and we initialize it as late as possible.
666 get_random_bytes(&rand
, sizeof(rand
));
668 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
671 static struct nf_conn
*
672 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
673 const struct nf_conntrack_tuple
*orig
,
674 const struct nf_conntrack_tuple
*repl
,
679 if (unlikely(!nf_conntrack_hash_rnd
)) {
680 init_nf_conntrack_hash_rnd();
681 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
682 hash
= hash_conntrack_raw(orig
, zone
);
685 /* We don't want any race condition at early drop stage */
686 atomic_inc(&net
->ct
.count
);
688 if (nf_conntrack_max
&&
689 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
690 if (!early_drop(net
, hash_bucket(hash
, net
))) {
691 atomic_dec(&net
->ct
.count
);
692 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
693 return ERR_PTR(-ENOMEM
);
698 * Do not use kmem_cache_zalloc(), as this cache uses
699 * SLAB_DESTROY_BY_RCU.
701 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
703 atomic_dec(&net
->ct
.count
);
704 return ERR_PTR(-ENOMEM
);
707 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
708 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
710 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
711 offsetof(struct nf_conn
, proto
) -
712 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
713 spin_lock_init(&ct
->lock
);
714 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
715 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
716 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
717 /* save hash for reusing when confirming */
718 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
719 /* Don't set timer yet: wait for confirmation */
720 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
721 write_pnet(&ct
->ct_net
, net
);
722 #ifdef CONFIG_NF_CONNTRACK_ZONES
724 struct nf_conntrack_zone
*nf_ct_zone
;
726 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
729 nf_ct_zone
->id
= zone
;
733 * changes to lookup keys must be done before setting refcnt to 1
736 atomic_set(&ct
->ct_general
.use
, 1);
739 #ifdef CONFIG_NF_CONNTRACK_ZONES
741 atomic_dec(&net
->ct
.count
);
742 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
743 return ERR_PTR(-ENOMEM
);
747 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
748 const struct nf_conntrack_tuple
*orig
,
749 const struct nf_conntrack_tuple
*repl
,
752 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
754 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
756 void nf_conntrack_free(struct nf_conn
*ct
)
758 struct net
*net
= nf_ct_net(ct
);
760 nf_ct_ext_destroy(ct
);
761 atomic_dec(&net
->ct
.count
);
763 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
765 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
767 /* Allocate a new conntrack: we return -ENOMEM if classification
768 failed due to stress. Otherwise it really is unclassifiable. */
769 static struct nf_conntrack_tuple_hash
*
770 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
771 const struct nf_conntrack_tuple
*tuple
,
772 struct nf_conntrack_l3proto
*l3proto
,
773 struct nf_conntrack_l4proto
*l4proto
,
775 unsigned int dataoff
, u32 hash
)
778 struct nf_conn_help
*help
;
779 struct nf_conntrack_tuple repl_tuple
;
780 struct nf_conntrack_ecache
*ecache
;
781 struct nf_conntrack_expect
*exp
;
782 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
783 struct nf_conn_timeout
*timeout_ext
;
784 unsigned int *timeouts
;
786 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
787 pr_debug("Can't invert tuple.\n");
791 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
794 return (struct nf_conntrack_tuple_hash
*)ct
;
796 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
798 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
800 timeouts
= l4proto
->get_timeouts(net
);
802 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
803 nf_conntrack_free(ct
);
804 pr_debug("init conntrack: can't track with proto module\n");
809 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
811 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
812 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
814 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
815 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
816 ecache
? ecache
->expmask
: 0,
819 spin_lock_bh(&nf_conntrack_lock
);
820 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
822 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
824 /* Welcome, Mr. Bond. We've been expecting you... */
825 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
826 ct
->master
= exp
->master
;
828 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
831 rcu_assign_pointer(help
->helper
, exp
->helper
);
834 #ifdef CONFIG_NF_CONNTRACK_MARK
835 ct
->mark
= exp
->master
->mark
;
837 #ifdef CONFIG_NF_CONNTRACK_SECMARK
838 ct
->secmark
= exp
->master
->secmark
;
840 nf_conntrack_get(&ct
->master
->ct_general
);
841 NF_CT_STAT_INC(net
, expect_new
);
843 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
844 NF_CT_STAT_INC(net
, new);
847 /* Overload tuple linked list to put us in unconfirmed list. */
848 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
849 &net
->ct
.unconfirmed
);
851 spin_unlock_bh(&nf_conntrack_lock
);
855 exp
->expectfn(ct
, exp
);
856 nf_ct_expect_put(exp
);
859 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
862 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
863 static inline struct nf_conn
*
864 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
866 unsigned int dataoff
,
869 struct nf_conntrack_l3proto
*l3proto
,
870 struct nf_conntrack_l4proto
*l4proto
,
872 enum ip_conntrack_info
*ctinfo
)
874 struct nf_conntrack_tuple tuple
;
875 struct nf_conntrack_tuple_hash
*h
;
877 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
880 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
881 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
883 pr_debug("resolve_normal_ct: Can't get tuple\n");
887 /* look for tuple match */
888 hash
= hash_conntrack_raw(&tuple
, zone
);
889 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
891 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
898 ct
= nf_ct_tuplehash_to_ctrack(h
);
900 /* It exists; we have (non-exclusive) reference. */
901 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
902 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
903 /* Please set reply bit if this packet OK */
906 /* Once we've had two way comms, always ESTABLISHED. */
907 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
908 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
909 *ctinfo
= IP_CT_ESTABLISHED
;
910 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
911 pr_debug("nf_conntrack_in: related packet for %p\n",
913 *ctinfo
= IP_CT_RELATED
;
915 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
920 skb
->nfct
= &ct
->ct_general
;
921 skb
->nfctinfo
= *ctinfo
;
926 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
929 struct nf_conn
*ct
, *tmpl
= NULL
;
930 enum ip_conntrack_info ctinfo
;
931 struct nf_conntrack_l3proto
*l3proto
;
932 struct nf_conntrack_l4proto
*l4proto
;
933 struct nf_conn_timeout
*timeout_ext
;
934 unsigned int *timeouts
;
935 unsigned int dataoff
;
941 /* Previously seen (loopback or untracked)? Ignore. */
942 tmpl
= (struct nf_conn
*)skb
->nfct
;
943 if (!nf_ct_is_template(tmpl
)) {
944 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
950 /* rcu_read_lock()ed by nf_hook_slow */
951 l3proto
= __nf_ct_l3proto_find(pf
);
952 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
953 &dataoff
, &protonum
);
955 pr_debug("not prepared to track yet or error occurred\n");
956 NF_CT_STAT_INC_ATOMIC(net
, error
);
957 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
962 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
964 /* It may be an special packet, error, unclean...
965 * inverse of the return code tells to the netfilter
966 * core what to do with the packet. */
967 if (l4proto
->error
!= NULL
) {
968 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
971 NF_CT_STAT_INC_ATOMIC(net
, error
);
972 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
976 /* ICMP[v6] protocol trackers may assign one conntrack. */
981 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
982 l3proto
, l4proto
, &set_reply
, &ctinfo
);
984 /* Not valid part of a connection */
985 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
991 /* Too stressed to deal. */
992 NF_CT_STAT_INC_ATOMIC(net
, drop
);
997 NF_CT_ASSERT(skb
->nfct
);
999 /* Decide what timeout policy we want to apply to this flow. */
1000 timeout_ext
= nf_ct_timeout_find(ct
);
1002 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
1004 timeouts
= l4proto
->get_timeouts(net
);
1006 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1008 /* Invalid: inverse of the return code tells
1009 * the netfilter core what to do */
1010 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1011 nf_conntrack_put(skb
->nfct
);
1013 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1014 if (ret
== -NF_DROP
)
1015 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1020 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1021 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1024 /* Special case: we have to repeat this hook, assign the
1025 * template again to this packet. We assume that this packet
1026 * has no conntrack assigned. This is used by nf_ct_tcp. */
1027 if (ret
== NF_REPEAT
)
1028 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1035 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1037 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1038 const struct nf_conntrack_tuple
*orig
)
1043 ret
= nf_ct_invert_tuple(inverse
, orig
,
1044 __nf_ct_l3proto_find(orig
->src
.l3num
),
1045 __nf_ct_l4proto_find(orig
->src
.l3num
,
1046 orig
->dst
.protonum
));
1050 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1052 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1053 implicitly racy: see __nf_conntrack_confirm */
1054 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1055 const struct nf_conntrack_tuple
*newreply
)
1057 struct nf_conn_help
*help
= nfct_help(ct
);
1059 /* Should be unconfirmed, so not in hash table yet */
1060 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1062 pr_debug("Altering reply tuple of %p to ", ct
);
1063 nf_ct_dump_tuple(newreply
);
1065 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1066 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1070 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1073 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1075 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1076 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1077 enum ip_conntrack_info ctinfo
,
1078 const struct sk_buff
*skb
,
1079 unsigned long extra_jiffies
,
1082 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1085 /* Only update if this is not a fixed timeout */
1086 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1089 /* If not in hash table, timer will not be active yet */
1090 if (!nf_ct_is_confirmed(ct
)) {
1091 ct
->timeout
.expires
= extra_jiffies
;
1093 unsigned long newtime
= jiffies
+ extra_jiffies
;
1095 /* Only update the timeout if the new timeout is at least
1096 HZ jiffies from the old timeout. Need del_timer for race
1097 avoidance (may already be dying). */
1098 if (newtime
- ct
->timeout
.expires
>= HZ
)
1099 mod_timer_pending(&ct
->timeout
, newtime
);
1104 struct nf_conn_counter
*acct
;
1106 acct
= nf_conn_acct_find(ct
);
1108 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1109 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1113 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1115 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1116 enum ip_conntrack_info ctinfo
,
1117 const struct sk_buff
*skb
,
1121 struct nf_conn_counter
*acct
;
1123 acct
= nf_conn_acct_find(ct
);
1125 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1126 atomic64_add(skb
->len
- skb_network_offset(skb
),
1127 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1131 if (del_timer(&ct
->timeout
)) {
1132 ct
->timeout
.function((unsigned long)ct
);
1137 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1139 #ifdef CONFIG_NF_CONNTRACK_ZONES
1140 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1141 .len
= sizeof(struct nf_conntrack_zone
),
1142 .align
= __alignof__(struct nf_conntrack_zone
),
1143 .id
= NF_CT_EXT_ZONE
,
1147 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1149 #include <linux/netfilter/nfnetlink.h>
1150 #include <linux/netfilter/nfnetlink_conntrack.h>
1151 #include <linux/mutex.h>
1153 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1154 * in ip_conntrack_core, since we don't want the protocols to autoload
1155 * or depend on ctnetlink */
1156 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1157 const struct nf_conntrack_tuple
*tuple
)
1159 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1160 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1161 goto nla_put_failure
;
1167 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1169 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1170 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1171 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1173 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1175 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1176 struct nf_conntrack_tuple
*t
)
1178 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1181 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1182 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1186 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1188 int nf_ct_port_nlattr_tuple_size(void)
1190 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1192 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1195 /* Used by ipt_REJECT and ip6t_REJECT. */
1196 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1199 enum ip_conntrack_info ctinfo
;
1201 /* This ICMP is in reverse direction to the packet which caused it */
1202 ct
= nf_ct_get(skb
, &ctinfo
);
1203 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1204 ctinfo
= IP_CT_RELATED_REPLY
;
1206 ctinfo
= IP_CT_RELATED
;
1208 /* Attach to new skbuff, and increment count */
1209 nskb
->nfct
= &ct
->ct_general
;
1210 nskb
->nfctinfo
= ctinfo
;
1211 nf_conntrack_get(nskb
->nfct
);
1214 /* Bring out ya dead! */
1215 static struct nf_conn
*
1216 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1217 void *data
, unsigned int *bucket
)
1219 struct nf_conntrack_tuple_hash
*h
;
1221 struct hlist_nulls_node
*n
;
1223 spin_lock_bh(&nf_conntrack_lock
);
1224 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1225 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1226 ct
= nf_ct_tuplehash_to_ctrack(h
);
1231 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1232 ct
= nf_ct_tuplehash_to_ctrack(h
);
1234 set_bit(IPS_DYING_BIT
, &ct
->status
);
1236 spin_unlock_bh(&nf_conntrack_lock
);
1239 atomic_inc(&ct
->ct_general
.use
);
1240 spin_unlock_bh(&nf_conntrack_lock
);
1244 void nf_ct_iterate_cleanup(struct net
*net
,
1245 int (*iter
)(struct nf_conn
*i
, void *data
),
1249 unsigned int bucket
= 0;
1251 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1252 /* Time to push up daises... */
1253 if (del_timer(&ct
->timeout
))
1254 death_by_timeout((unsigned long)ct
);
1255 /* ... else the timer will get him soon. */
1260 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1262 struct __nf_ct_flush_report
{
1267 static int kill_report(struct nf_conn
*i
, void *data
)
1269 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1270 struct nf_conn_tstamp
*tstamp
;
1272 tstamp
= nf_conn_tstamp_find(i
);
1273 if (tstamp
&& tstamp
->stop
== 0)
1274 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1276 /* If we fail to deliver the event, death_by_timeout() will retry */
1277 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1278 fr
->pid
, fr
->report
) < 0)
1281 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1282 set_bit(IPS_DYING_BIT
, &i
->status
);
1286 static int kill_all(struct nf_conn
*i
, void *data
)
1291 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1293 if (is_vmalloc_addr(hash
))
1296 free_pages((unsigned long)hash
,
1297 get_order(sizeof(struct hlist_head
) * size
));
1299 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1301 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1303 struct __nf_ct_flush_report fr
= {
1307 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1309 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1311 static void nf_ct_release_dying_list(struct net
*net
)
1313 struct nf_conntrack_tuple_hash
*h
;
1315 struct hlist_nulls_node
*n
;
1317 spin_lock_bh(&nf_conntrack_lock
);
1318 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1319 ct
= nf_ct_tuplehash_to_ctrack(h
);
1320 /* never fails to remove them, no listeners at this point */
1323 spin_unlock_bh(&nf_conntrack_lock
);
1326 static int untrack_refs(void)
1330 for_each_possible_cpu(cpu
) {
1331 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1333 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1338 static void nf_conntrack_cleanup_init_net(void)
1340 while (untrack_refs() > 0)
1343 #ifdef CONFIG_NF_CONNTRACK_ZONES
1344 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1348 static void nf_conntrack_cleanup_net(struct net
*net
)
1351 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1352 nf_ct_release_dying_list(net
);
1353 if (atomic_read(&net
->ct
.count
) != 0) {
1355 goto i_see_dead_people
;
1358 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1359 nf_conntrack_helper_fini(net
);
1360 nf_conntrack_timeout_fini(net
);
1361 nf_conntrack_ecache_fini(net
);
1362 nf_conntrack_tstamp_fini(net
);
1363 nf_conntrack_acct_fini(net
);
1364 nf_conntrack_expect_fini(net
);
1365 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1366 kfree(net
->ct
.slabname
);
1367 free_percpu(net
->ct
.stat
);
1370 /* Mishearing the voices in his head, our hero wonders how he's
1371 supposed to kill the mall. */
1372 void nf_conntrack_cleanup(struct net
*net
)
1374 if (net_eq(net
, &init_net
))
1375 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1377 /* This makes sure all current packets have passed through
1378 netfilter framework. Roll on, two-stage module
1381 nf_conntrack_proto_fini(net
);
1382 nf_conntrack_cleanup_net(net
);
1384 if (net_eq(net
, &init_net
)) {
1385 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1386 nf_conntrack_cleanup_init_net();
1390 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1392 struct hlist_nulls_head
*hash
;
1393 unsigned int nr_slots
, i
;
1396 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1397 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1398 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1399 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1402 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1407 for (i
= 0; i
< nr_slots
; i
++)
1408 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1412 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1414 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1417 unsigned int hashsize
, old_size
;
1418 struct hlist_nulls_head
*hash
, *old_hash
;
1419 struct nf_conntrack_tuple_hash
*h
;
1422 if (current
->nsproxy
->net_ns
!= &init_net
)
1425 /* On boot, we can set this without any fancy locking. */
1426 if (!nf_conntrack_htable_size
)
1427 return param_set_uint(val
, kp
);
1429 hashsize
= simple_strtoul(val
, NULL
, 0);
1433 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1437 /* Lookups in the old hash might happen in parallel, which means we
1438 * might get false negatives during connection lookup. New connections
1439 * created because of a false negative won't make it into the hash
1440 * though since that required taking the lock.
1442 spin_lock_bh(&nf_conntrack_lock
);
1443 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1444 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1445 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1446 struct nf_conntrack_tuple_hash
, hnnode
);
1447 ct
= nf_ct_tuplehash_to_ctrack(h
);
1448 hlist_nulls_del_rcu(&h
->hnnode
);
1449 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1451 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1454 old_size
= init_net
.ct
.htable_size
;
1455 old_hash
= init_net
.ct
.hash
;
1457 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1458 init_net
.ct
.hash
= hash
;
1459 spin_unlock_bh(&nf_conntrack_lock
);
1461 nf_ct_free_hashtable(old_hash
, old_size
);
1464 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1466 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1467 &nf_conntrack_htable_size
, 0600);
1469 void nf_ct_untracked_status_or(unsigned long bits
)
1473 for_each_possible_cpu(cpu
)
1474 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1476 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1478 static int nf_conntrack_init_init_net(void)
1483 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1484 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1485 if (!nf_conntrack_htable_size
) {
1486 nf_conntrack_htable_size
1487 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1488 / sizeof(struct hlist_head
));
1489 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1490 nf_conntrack_htable_size
= 16384;
1491 if (nf_conntrack_htable_size
< 32)
1492 nf_conntrack_htable_size
= 32;
1494 /* Use a max. factor of four by default to get the same max as
1495 * with the old struct list_heads. When a table size is given
1496 * we use the old value of 8 to avoid reducing the max.
1500 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1502 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1503 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1505 #ifdef CONFIG_NF_CONNTRACK_ZONES
1506 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1510 /* Set up fake conntrack: to never be deleted, not in any hashes */
1511 for_each_possible_cpu(cpu
) {
1512 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1513 write_pnet(&ct
->ct_net
, &init_net
);
1514 atomic_set(&ct
->ct_general
.use
, 1);
1516 /* - and look it like as a confirmed connection */
1517 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1520 #ifdef CONFIG_NF_CONNTRACK_ZONES
1527 * We need to use special "null" values, not used in hash table
1529 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1530 #define DYING_NULLS_VAL ((1<<30)+1)
1532 static int nf_conntrack_init_net(struct net
*net
)
1536 atomic_set(&net
->ct
.count
, 0);
1537 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1538 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1539 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1540 if (!net
->ct
.stat
) {
1545 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1546 if (!net
->ct
.slabname
) {
1551 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1552 sizeof(struct nf_conn
), 0,
1553 SLAB_DESTROY_BY_RCU
, NULL
);
1554 if (!net
->ct
.nf_conntrack_cachep
) {
1555 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1560 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1561 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1562 if (!net
->ct
.hash
) {
1564 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1567 ret
= nf_conntrack_expect_init(net
);
1570 ret
= nf_conntrack_acct_init(net
);
1573 ret
= nf_conntrack_tstamp_init(net
);
1576 ret
= nf_conntrack_ecache_init(net
);
1579 ret
= nf_conntrack_timeout_init(net
);
1582 ret
= nf_conntrack_helper_init(net
);
1587 nf_conntrack_timeout_fini(net
);
1589 nf_conntrack_ecache_fini(net
);
1591 nf_conntrack_tstamp_fini(net
);
1593 nf_conntrack_acct_fini(net
);
1595 nf_conntrack_expect_fini(net
);
1597 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1599 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1601 kfree(net
->ct
.slabname
);
1603 free_percpu(net
->ct
.stat
);
1608 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1609 enum ip_conntrack_dir dir
,
1611 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1613 int nf_conntrack_init(struct net
*net
)
1617 if (net_eq(net
, &init_net
)) {
1618 ret
= nf_conntrack_init_init_net();
1622 ret
= nf_conntrack_proto_init(net
);
1625 ret
= nf_conntrack_init_net(net
);
1629 if (net_eq(net
, &init_net
)) {
1630 /* For use by REJECT target */
1631 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1632 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1634 /* Howto get NAT offsets */
1635 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1640 nf_conntrack_proto_fini(net
);
1642 if (net_eq(net
, &init_net
))
1643 nf_conntrack_cleanup_init_net();