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_conntrack_labels.h>
49 #include <net/netfilter/nf_nat.h>
50 #include <net/netfilter/nf_nat_core.h>
52 #define NF_CONNTRACK_VERSION "0.5.0"
54 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
55 enum nf_nat_manip_type manip
,
56 const struct nlattr
*attr
) __read_mostly
;
57 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
59 int (*nf_nat_seq_adjust_hook
)(struct sk_buff
*skb
,
61 enum ip_conntrack_info ctinfo
,
62 unsigned int protoff
);
63 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook
);
65 DEFINE_SPINLOCK(nf_conntrack_lock
);
66 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
68 unsigned int nf_conntrack_htable_size __read_mostly
;
69 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
71 unsigned int nf_conntrack_max __read_mostly
;
72 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
74 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
75 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
77 unsigned int nf_conntrack_hash_rnd __read_mostly
;
78 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
80 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
84 /* The direction must be ignored, so we hash everything up to the
85 * destination ports (which is a multiple of 4) and treat the last
86 * three bytes manually.
88 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
89 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
90 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
91 tuple
->dst
.protonum
));
94 static u32
__hash_bucket(u32 hash
, unsigned int size
)
96 return ((u64
)hash
* size
) >> 32;
99 static u32
hash_bucket(u32 hash
, const struct net
*net
)
101 return __hash_bucket(hash
, net
->ct
.htable_size
);
104 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
105 u16 zone
, unsigned int size
)
107 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
110 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
111 const struct nf_conntrack_tuple
*tuple
)
113 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
117 nf_ct_get_tuple(const struct sk_buff
*skb
,
119 unsigned int dataoff
,
122 struct nf_conntrack_tuple
*tuple
,
123 const struct nf_conntrack_l3proto
*l3proto
,
124 const struct nf_conntrack_l4proto
*l4proto
)
126 memset(tuple
, 0, sizeof(*tuple
));
128 tuple
->src
.l3num
= l3num
;
129 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
132 tuple
->dst
.protonum
= protonum
;
133 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
135 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
137 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
139 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
140 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
142 struct nf_conntrack_l3proto
*l3proto
;
143 struct nf_conntrack_l4proto
*l4proto
;
144 unsigned int protoff
;
150 l3proto
= __nf_ct_l3proto_find(l3num
);
151 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
152 if (ret
!= NF_ACCEPT
) {
157 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
159 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
165 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
168 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
169 const struct nf_conntrack_tuple
*orig
,
170 const struct nf_conntrack_l3proto
*l3proto
,
171 const struct nf_conntrack_l4proto
*l4proto
)
173 memset(inverse
, 0, sizeof(*inverse
));
175 inverse
->src
.l3num
= orig
->src
.l3num
;
176 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
179 inverse
->dst
.dir
= !orig
->dst
.dir
;
181 inverse
->dst
.protonum
= orig
->dst
.protonum
;
182 return l4proto
->invert_tuple(inverse
, orig
);
184 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
187 clean_from_lists(struct nf_conn
*ct
)
189 pr_debug("clean_from_lists(%p)\n", ct
);
190 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
191 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
193 /* Destroy all pending expectations */
194 nf_ct_remove_expectations(ct
);
198 destroy_conntrack(struct nf_conntrack
*nfct
)
200 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
201 struct net
*net
= nf_ct_net(ct
);
202 struct nf_conntrack_l4proto
*l4proto
;
204 pr_debug("destroy_conntrack(%p)\n", ct
);
205 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
206 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
208 /* To make sure we don't get any weird locking issues here:
209 * destroy_conntrack() MUST NOT be called with a write lock
210 * to nf_conntrack_lock!!! -HW */
212 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
213 if (l4proto
&& l4proto
->destroy
)
214 l4proto
->destroy(ct
);
218 spin_lock_bh(&nf_conntrack_lock
);
219 /* Expectations will have been removed in clean_from_lists,
220 * except TFTP can create an expectation on the first packet,
221 * before connection is in the list, so we need to clean here,
223 nf_ct_remove_expectations(ct
);
225 /* We overload first tuple to link into unconfirmed or dying list.*/
226 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
227 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
229 NF_CT_STAT_INC(net
, delete);
230 spin_unlock_bh(&nf_conntrack_lock
);
233 nf_ct_put(ct
->master
);
235 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
236 nf_conntrack_free(ct
);
239 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
241 struct net
*net
= nf_ct_net(ct
);
243 nf_ct_helper_destroy(ct
);
244 spin_lock_bh(&nf_conntrack_lock
);
245 /* Inside lock so preempt is disabled on module removal path.
246 * Otherwise we can get spurious warnings. */
247 NF_CT_STAT_INC(net
, delete_list
);
248 clean_from_lists(ct
);
249 /* add this conntrack to the dying list */
250 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
252 spin_unlock_bh(&nf_conntrack_lock
);
254 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
256 static void death_by_event(unsigned long ul_conntrack
)
258 struct nf_conn
*ct
= (void *)ul_conntrack
;
259 struct net
*net
= nf_ct_net(ct
);
260 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
262 BUG_ON(ecache
== NULL
);
264 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
265 /* bad luck, let's retry again */
266 ecache
->timeout
.expires
= jiffies
+
267 (random32() % net
->ct
.sysctl_events_retry_timeout
);
268 add_timer(&ecache
->timeout
);
271 /* we've got the event delivered, now it's dying */
272 set_bit(IPS_DYING_BIT
, &ct
->status
);
276 void nf_ct_dying_timeout(struct nf_conn
*ct
)
278 struct net
*net
= nf_ct_net(ct
);
279 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
281 BUG_ON(ecache
== NULL
);
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_dying_timeout
);
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_dying_timeout(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
);
768 /* Allocate a new conntrack: we return -ENOMEM if classification
769 failed due to stress. Otherwise it really is unclassifiable. */
770 static struct nf_conntrack_tuple_hash
*
771 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
772 const struct nf_conntrack_tuple
*tuple
,
773 struct nf_conntrack_l3proto
*l3proto
,
774 struct nf_conntrack_l4proto
*l4proto
,
776 unsigned int dataoff
, u32 hash
)
779 struct nf_conn_help
*help
;
780 struct nf_conntrack_tuple repl_tuple
;
781 struct nf_conntrack_ecache
*ecache
;
782 struct nf_conntrack_expect
*exp
;
783 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
784 struct nf_conn_timeout
*timeout_ext
;
785 unsigned int *timeouts
;
787 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
788 pr_debug("Can't invert tuple.\n");
792 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
795 return (struct nf_conntrack_tuple_hash
*)ct
;
797 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
799 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
801 timeouts
= l4proto
->get_timeouts(net
);
803 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
804 nf_conntrack_free(ct
);
805 pr_debug("init conntrack: can't track with proto module\n");
810 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
812 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
813 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
814 nf_ct_labels_ext_add(ct
);
816 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
817 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
818 ecache
? ecache
->expmask
: 0,
821 spin_lock_bh(&nf_conntrack_lock
);
822 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
824 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
826 /* Welcome, Mr. Bond. We've been expecting you... */
827 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
828 ct
->master
= exp
->master
;
830 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
833 rcu_assign_pointer(help
->helper
, exp
->helper
);
836 #ifdef CONFIG_NF_CONNTRACK_MARK
837 ct
->mark
= exp
->master
->mark
;
839 #ifdef CONFIG_NF_CONNTRACK_SECMARK
840 ct
->secmark
= exp
->master
->secmark
;
842 nf_conntrack_get(&ct
->master
->ct_general
);
843 NF_CT_STAT_INC(net
, expect_new
);
845 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
846 NF_CT_STAT_INC(net
, new);
849 /* Overload tuple linked list to put us in unconfirmed list. */
850 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
851 &net
->ct
.unconfirmed
);
853 spin_unlock_bh(&nf_conntrack_lock
);
857 exp
->expectfn(ct
, exp
);
858 nf_ct_expect_put(exp
);
861 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
864 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
865 static inline struct nf_conn
*
866 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
868 unsigned int dataoff
,
871 struct nf_conntrack_l3proto
*l3proto
,
872 struct nf_conntrack_l4proto
*l4proto
,
874 enum ip_conntrack_info
*ctinfo
)
876 struct nf_conntrack_tuple tuple
;
877 struct nf_conntrack_tuple_hash
*h
;
879 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
882 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
883 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
885 pr_debug("resolve_normal_ct: Can't get tuple\n");
889 /* look for tuple match */
890 hash
= hash_conntrack_raw(&tuple
, zone
);
891 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
893 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
900 ct
= nf_ct_tuplehash_to_ctrack(h
);
902 /* It exists; we have (non-exclusive) reference. */
903 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
904 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
905 /* Please set reply bit if this packet OK */
908 /* Once we've had two way comms, always ESTABLISHED. */
909 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
910 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
911 *ctinfo
= IP_CT_ESTABLISHED
;
912 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
913 pr_debug("nf_conntrack_in: related packet for %p\n",
915 *ctinfo
= IP_CT_RELATED
;
917 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
922 skb
->nfct
= &ct
->ct_general
;
923 skb
->nfctinfo
= *ctinfo
;
928 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
931 struct nf_conn
*ct
, *tmpl
= NULL
;
932 enum ip_conntrack_info ctinfo
;
933 struct nf_conntrack_l3proto
*l3proto
;
934 struct nf_conntrack_l4proto
*l4proto
;
935 unsigned int *timeouts
;
936 unsigned int dataoff
;
942 /* Previously seen (loopback or untracked)? Ignore. */
943 tmpl
= (struct nf_conn
*)skb
->nfct
;
944 if (!nf_ct_is_template(tmpl
)) {
945 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
951 /* rcu_read_lock()ed by nf_hook_slow */
952 l3proto
= __nf_ct_l3proto_find(pf
);
953 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
954 &dataoff
, &protonum
);
956 pr_debug("not prepared to track yet or error occurred\n");
957 NF_CT_STAT_INC_ATOMIC(net
, error
);
958 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
963 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
965 /* It may be an special packet, error, unclean...
966 * inverse of the return code tells to the netfilter
967 * core what to do with the packet. */
968 if (l4proto
->error
!= NULL
) {
969 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
972 NF_CT_STAT_INC_ATOMIC(net
, error
);
973 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
977 /* ICMP[v6] protocol trackers may assign one conntrack. */
982 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
983 l3proto
, l4proto
, &set_reply
, &ctinfo
);
985 /* Not valid part of a connection */
986 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
992 /* Too stressed to deal. */
993 NF_CT_STAT_INC_ATOMIC(net
, drop
);
998 NF_CT_ASSERT(skb
->nfct
);
1000 /* Decide what timeout policy we want to apply to this flow. */
1001 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1003 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1005 /* Invalid: inverse of the return code tells
1006 * the netfilter core what to do */
1007 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1008 nf_conntrack_put(skb
->nfct
);
1010 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1011 if (ret
== -NF_DROP
)
1012 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1017 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1018 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1021 /* Special case: we have to repeat this hook, assign the
1022 * template again to this packet. We assume that this packet
1023 * has no conntrack assigned. This is used by nf_ct_tcp. */
1024 if (ret
== NF_REPEAT
)
1025 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1032 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1034 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1035 const struct nf_conntrack_tuple
*orig
)
1040 ret
= nf_ct_invert_tuple(inverse
, orig
,
1041 __nf_ct_l3proto_find(orig
->src
.l3num
),
1042 __nf_ct_l4proto_find(orig
->src
.l3num
,
1043 orig
->dst
.protonum
));
1047 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1049 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1050 implicitly racy: see __nf_conntrack_confirm */
1051 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1052 const struct nf_conntrack_tuple
*newreply
)
1054 struct nf_conn_help
*help
= nfct_help(ct
);
1056 /* Should be unconfirmed, so not in hash table yet */
1057 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1059 pr_debug("Altering reply tuple of %p to ", ct
);
1060 nf_ct_dump_tuple(newreply
);
1062 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1063 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1067 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1070 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1072 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1073 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1074 enum ip_conntrack_info ctinfo
,
1075 const struct sk_buff
*skb
,
1076 unsigned long extra_jiffies
,
1079 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1082 /* Only update if this is not a fixed timeout */
1083 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1086 /* If not in hash table, timer will not be active yet */
1087 if (!nf_ct_is_confirmed(ct
)) {
1088 ct
->timeout
.expires
= extra_jiffies
;
1090 unsigned long newtime
= jiffies
+ extra_jiffies
;
1092 /* Only update the timeout if the new timeout is at least
1093 HZ jiffies from the old timeout. Need del_timer for race
1094 avoidance (may already be dying). */
1095 if (newtime
- ct
->timeout
.expires
>= HZ
)
1096 mod_timer_pending(&ct
->timeout
, newtime
);
1101 struct nf_conn_counter
*acct
;
1103 acct
= nf_conn_acct_find(ct
);
1105 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1106 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1110 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1112 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1113 enum ip_conntrack_info ctinfo
,
1114 const struct sk_buff
*skb
,
1118 struct nf_conn_counter
*acct
;
1120 acct
= nf_conn_acct_find(ct
);
1122 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1123 atomic64_add(skb
->len
- skb_network_offset(skb
),
1124 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1128 if (del_timer(&ct
->timeout
)) {
1129 ct
->timeout
.function((unsigned long)ct
);
1134 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1136 #ifdef CONFIG_NF_CONNTRACK_ZONES
1137 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1138 .len
= sizeof(struct nf_conntrack_zone
),
1139 .align
= __alignof__(struct nf_conntrack_zone
),
1140 .id
= NF_CT_EXT_ZONE
,
1144 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1146 #include <linux/netfilter/nfnetlink.h>
1147 #include <linux/netfilter/nfnetlink_conntrack.h>
1148 #include <linux/mutex.h>
1150 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1151 * in ip_conntrack_core, since we don't want the protocols to autoload
1152 * or depend on ctnetlink */
1153 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1154 const struct nf_conntrack_tuple
*tuple
)
1156 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1157 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1158 goto nla_put_failure
;
1164 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1166 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1167 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1168 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1170 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1172 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1173 struct nf_conntrack_tuple
*t
)
1175 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1178 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1179 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1183 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1185 int nf_ct_port_nlattr_tuple_size(void)
1187 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1189 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1192 /* Used by ipt_REJECT and ip6t_REJECT. */
1193 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1196 enum ip_conntrack_info ctinfo
;
1198 /* This ICMP is in reverse direction to the packet which caused it */
1199 ct
= nf_ct_get(skb
, &ctinfo
);
1200 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1201 ctinfo
= IP_CT_RELATED_REPLY
;
1203 ctinfo
= IP_CT_RELATED
;
1205 /* Attach to new skbuff, and increment count */
1206 nskb
->nfct
= &ct
->ct_general
;
1207 nskb
->nfctinfo
= ctinfo
;
1208 nf_conntrack_get(nskb
->nfct
);
1211 /* Bring out ya dead! */
1212 static struct nf_conn
*
1213 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1214 void *data
, unsigned int *bucket
)
1216 struct nf_conntrack_tuple_hash
*h
;
1218 struct hlist_nulls_node
*n
;
1220 spin_lock_bh(&nf_conntrack_lock
);
1221 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1222 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1223 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1225 ct
= nf_ct_tuplehash_to_ctrack(h
);
1230 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1231 ct
= nf_ct_tuplehash_to_ctrack(h
);
1233 set_bit(IPS_DYING_BIT
, &ct
->status
);
1235 spin_unlock_bh(&nf_conntrack_lock
);
1238 atomic_inc(&ct
->ct_general
.use
);
1239 spin_unlock_bh(&nf_conntrack_lock
);
1243 void nf_ct_iterate_cleanup(struct net
*net
,
1244 int (*iter
)(struct nf_conn
*i
, void *data
),
1248 unsigned int bucket
= 0;
1250 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1251 /* Time to push up daises... */
1252 if (del_timer(&ct
->timeout
))
1253 death_by_timeout((unsigned long)ct
);
1254 /* ... else the timer will get him soon. */
1259 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1261 struct __nf_ct_flush_report
{
1266 static int kill_report(struct nf_conn
*i
, void *data
)
1268 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1269 struct nf_conn_tstamp
*tstamp
;
1271 tstamp
= nf_conn_tstamp_find(i
);
1272 if (tstamp
&& tstamp
->stop
== 0)
1273 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1275 /* If we fail to deliver the event, death_by_timeout() will retry */
1276 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1277 fr
->pid
, fr
->report
) < 0)
1280 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1281 set_bit(IPS_DYING_BIT
, &i
->status
);
1285 static int kill_all(struct nf_conn
*i
, void *data
)
1290 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1292 if (is_vmalloc_addr(hash
))
1295 free_pages((unsigned long)hash
,
1296 get_order(sizeof(struct hlist_head
) * size
));
1298 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1300 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1302 struct __nf_ct_flush_report fr
= {
1306 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1308 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1310 static void nf_ct_release_dying_list(struct net
*net
)
1312 struct nf_conntrack_tuple_hash
*h
;
1314 struct hlist_nulls_node
*n
;
1316 spin_lock_bh(&nf_conntrack_lock
);
1317 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1318 ct
= nf_ct_tuplehash_to_ctrack(h
);
1319 /* never fails to remove them, no listeners at this point */
1322 spin_unlock_bh(&nf_conntrack_lock
);
1325 static int untrack_refs(void)
1329 for_each_possible_cpu(cpu
) {
1330 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1332 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1337 void nf_conntrack_cleanup_start(void)
1339 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1342 void nf_conntrack_cleanup_end(void)
1344 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1345 while (untrack_refs() > 0)
1348 #ifdef CONFIG_NF_CONNTRACK_ZONES
1349 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1351 nf_conntrack_proto_fini();
1352 nf_conntrack_labels_fini();
1353 nf_conntrack_helper_fini();
1354 nf_conntrack_timeout_fini();
1355 nf_conntrack_ecache_fini();
1356 nf_conntrack_tstamp_fini();
1357 nf_conntrack_acct_fini();
1358 nf_conntrack_expect_fini();
1362 * Mishearing the voices in his head, our hero wonders how he's
1363 * supposed to kill the mall.
1365 void nf_conntrack_cleanup_net(struct net
*net
)
1368 * This makes sure all current packets have passed through
1369 * netfilter framework. Roll on, two-stage module
1374 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1375 nf_ct_release_dying_list(net
);
1376 if (atomic_read(&net
->ct
.count
) != 0) {
1378 goto i_see_dead_people
;
1381 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1382 nf_conntrack_proto_pernet_fini(net
);
1383 nf_conntrack_helper_pernet_fini(net
);
1384 nf_conntrack_ecache_pernet_fini(net
);
1385 nf_conntrack_tstamp_pernet_fini(net
);
1386 nf_conntrack_acct_pernet_fini(net
);
1387 nf_conntrack_expect_pernet_fini(net
);
1388 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1389 kfree(net
->ct
.slabname
);
1390 free_percpu(net
->ct
.stat
);
1393 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1395 struct hlist_nulls_head
*hash
;
1396 unsigned int nr_slots
, i
;
1399 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1400 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1401 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1402 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1405 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1410 for (i
= 0; i
< nr_slots
; i
++)
1411 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1415 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1417 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1420 unsigned int hashsize
, old_size
;
1421 struct hlist_nulls_head
*hash
, *old_hash
;
1422 struct nf_conntrack_tuple_hash
*h
;
1425 if (current
->nsproxy
->net_ns
!= &init_net
)
1428 /* On boot, we can set this without any fancy locking. */
1429 if (!nf_conntrack_htable_size
)
1430 return param_set_uint(val
, kp
);
1432 rc
= kstrtouint(val
, 0, &hashsize
);
1438 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1442 /* Lookups in the old hash might happen in parallel, which means we
1443 * might get false negatives during connection lookup. New connections
1444 * created because of a false negative won't make it into the hash
1445 * though since that required taking the lock.
1447 spin_lock_bh(&nf_conntrack_lock
);
1448 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1449 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1450 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1451 struct nf_conntrack_tuple_hash
, hnnode
);
1452 ct
= nf_ct_tuplehash_to_ctrack(h
);
1453 hlist_nulls_del_rcu(&h
->hnnode
);
1454 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1456 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1459 old_size
= init_net
.ct
.htable_size
;
1460 old_hash
= init_net
.ct
.hash
;
1462 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1463 init_net
.ct
.hash
= hash
;
1464 spin_unlock_bh(&nf_conntrack_lock
);
1466 nf_ct_free_hashtable(old_hash
, old_size
);
1469 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1471 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1472 &nf_conntrack_htable_size
, 0600);
1474 void nf_ct_untracked_status_or(unsigned long bits
)
1478 for_each_possible_cpu(cpu
)
1479 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1481 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1483 int nf_conntrack_init_start(void)
1488 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1489 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1490 if (!nf_conntrack_htable_size
) {
1491 nf_conntrack_htable_size
1492 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1493 / sizeof(struct hlist_head
));
1494 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1495 nf_conntrack_htable_size
= 16384;
1496 if (nf_conntrack_htable_size
< 32)
1497 nf_conntrack_htable_size
= 32;
1499 /* Use a max. factor of four by default to get the same max as
1500 * with the old struct list_heads. When a table size is given
1501 * we use the old value of 8 to avoid reducing the max.
1505 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1507 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1508 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1511 ret
= nf_conntrack_expect_init();
1515 ret
= nf_conntrack_acct_init();
1519 ret
= nf_conntrack_tstamp_init();
1523 ret
= nf_conntrack_ecache_init();
1527 ret
= nf_conntrack_timeout_init();
1531 ret
= nf_conntrack_helper_init();
1535 ret
= nf_conntrack_labels_init();
1539 #ifdef CONFIG_NF_CONNTRACK_ZONES
1540 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1544 ret
= nf_conntrack_proto_init();
1548 /* Set up fake conntrack: to never be deleted, not in any hashes */
1549 for_each_possible_cpu(cpu
) {
1550 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1551 write_pnet(&ct
->ct_net
, &init_net
);
1552 atomic_set(&ct
->ct_general
.use
, 1);
1554 /* - and look it like as a confirmed connection */
1555 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1559 #ifdef CONFIG_NF_CONNTRACK_ZONES
1560 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1563 nf_conntrack_labels_fini();
1565 nf_conntrack_helper_fini();
1567 nf_conntrack_timeout_fini();
1569 nf_conntrack_ecache_fini();
1571 nf_conntrack_tstamp_fini();
1573 nf_conntrack_acct_fini();
1575 nf_conntrack_expect_fini();
1580 void nf_conntrack_init_end(void)
1582 /* For use by REJECT target */
1583 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1584 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1586 /* Howto get NAT offsets */
1587 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1591 * We need to use special "null" values, not used in hash table
1593 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1594 #define DYING_NULLS_VAL ((1<<30)+1)
1595 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1597 int nf_conntrack_init_net(struct net
*net
)
1601 atomic_set(&net
->ct
.count
, 0);
1602 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1603 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1604 INIT_HLIST_NULLS_HEAD(&net
->ct
.tmpl
, TEMPLATE_NULLS_VAL
);
1605 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1606 if (!net
->ct
.stat
) {
1611 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1612 if (!net
->ct
.slabname
) {
1617 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1618 sizeof(struct nf_conn
), 0,
1619 SLAB_DESTROY_BY_RCU
, NULL
);
1620 if (!net
->ct
.nf_conntrack_cachep
) {
1621 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1626 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1627 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1628 if (!net
->ct
.hash
) {
1630 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1633 ret
= nf_conntrack_expect_pernet_init(net
);
1636 ret
= nf_conntrack_acct_pernet_init(net
);
1639 ret
= nf_conntrack_tstamp_pernet_init(net
);
1642 ret
= nf_conntrack_ecache_pernet_init(net
);
1645 ret
= nf_conntrack_helper_pernet_init(net
);
1648 ret
= nf_conntrack_proto_pernet_init(net
);
1654 nf_conntrack_helper_pernet_fini(net
);
1656 nf_conntrack_ecache_pernet_fini(net
);
1658 nf_conntrack_tstamp_pernet_fini(net
);
1660 nf_conntrack_acct_pernet_fini(net
);
1662 nf_conntrack_expect_pernet_fini(net
);
1664 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1666 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1668 kfree(net
->ct
.slabname
);
1670 free_percpu(net
->ct
.stat
);
1675 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1676 enum ip_conntrack_dir dir
,
1678 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);