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 int (*nf_nat_seq_adjust_hook
)(struct sk_buff
*skb
,
60 enum ip_conntrack_info ctinfo
,
61 unsigned int protoff
);
62 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook
);
64 DEFINE_SPINLOCK(nf_conntrack_lock
);
65 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
67 unsigned int nf_conntrack_htable_size __read_mostly
;
68 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
70 unsigned int nf_conntrack_max __read_mostly
;
71 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
73 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
74 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
76 unsigned int nf_conntrack_hash_rnd __read_mostly
;
77 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
79 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
83 /* The direction must be ignored, so we hash everything up to the
84 * destination ports (which is a multiple of 4) and treat the last
85 * three bytes manually.
87 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
88 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
89 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
90 tuple
->dst
.protonum
));
93 static u32
__hash_bucket(u32 hash
, unsigned int size
)
95 return ((u64
)hash
* size
) >> 32;
98 static u32
hash_bucket(u32 hash
, const struct net
*net
)
100 return __hash_bucket(hash
, net
->ct
.htable_size
);
103 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
104 u16 zone
, unsigned int size
)
106 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
109 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
110 const struct nf_conntrack_tuple
*tuple
)
112 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
116 nf_ct_get_tuple(const struct sk_buff
*skb
,
118 unsigned int dataoff
,
121 struct nf_conntrack_tuple
*tuple
,
122 const struct nf_conntrack_l3proto
*l3proto
,
123 const struct nf_conntrack_l4proto
*l4proto
)
125 memset(tuple
, 0, sizeof(*tuple
));
127 tuple
->src
.l3num
= l3num
;
128 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
131 tuple
->dst
.protonum
= protonum
;
132 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
134 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
136 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
138 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
139 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
141 struct nf_conntrack_l3proto
*l3proto
;
142 struct nf_conntrack_l4proto
*l4proto
;
143 unsigned int protoff
;
149 l3proto
= __nf_ct_l3proto_find(l3num
);
150 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
151 if (ret
!= NF_ACCEPT
) {
156 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
158 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
164 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
167 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
168 const struct nf_conntrack_tuple
*orig
,
169 const struct nf_conntrack_l3proto
*l3proto
,
170 const struct nf_conntrack_l4proto
*l4proto
)
172 memset(inverse
, 0, sizeof(*inverse
));
174 inverse
->src
.l3num
= orig
->src
.l3num
;
175 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
178 inverse
->dst
.dir
= !orig
->dst
.dir
;
180 inverse
->dst
.protonum
= orig
->dst
.protonum
;
181 return l4proto
->invert_tuple(inverse
, orig
);
183 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
186 clean_from_lists(struct nf_conn
*ct
)
188 pr_debug("clean_from_lists(%p)\n", ct
);
189 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
190 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
192 /* Destroy all pending expectations */
193 nf_ct_remove_expectations(ct
);
197 destroy_conntrack(struct nf_conntrack
*nfct
)
199 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
200 struct net
*net
= nf_ct_net(ct
);
201 struct nf_conntrack_l4proto
*l4proto
;
203 pr_debug("destroy_conntrack(%p)\n", ct
);
204 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
205 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
207 /* To make sure we don't get any weird locking issues here:
208 * destroy_conntrack() MUST NOT be called with a write lock
209 * to nf_conntrack_lock!!! -HW */
211 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
212 if (l4proto
&& l4proto
->destroy
)
213 l4proto
->destroy(ct
);
217 spin_lock_bh(&nf_conntrack_lock
);
218 /* Expectations will have been removed in clean_from_lists,
219 * except TFTP can create an expectation on the first packet,
220 * before connection is in the list, so we need to clean here,
222 nf_ct_remove_expectations(ct
);
224 /* We overload first tuple to link into unconfirmed list. */
225 if (!nf_ct_is_confirmed(ct
)) {
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
);
230 NF_CT_STAT_INC(net
, delete);
231 spin_unlock_bh(&nf_conntrack_lock
);
234 nf_ct_put(ct
->master
);
236 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
237 nf_conntrack_free(ct
);
240 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
242 struct net
*net
= nf_ct_net(ct
);
244 nf_ct_helper_destroy(ct
);
245 spin_lock_bh(&nf_conntrack_lock
);
246 /* Inside lock so preempt is disabled on module removal path.
247 * Otherwise we can get spurious warnings. */
248 NF_CT_STAT_INC(net
, delete_list
);
249 clean_from_lists(ct
);
250 spin_unlock_bh(&nf_conntrack_lock
);
252 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
254 static void death_by_event(unsigned long ul_conntrack
)
256 struct nf_conn
*ct
= (void *)ul_conntrack
;
257 struct net
*net
= nf_ct_net(ct
);
258 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
260 BUG_ON(ecache
== NULL
);
262 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
263 /* bad luck, let's retry again */
264 ecache
->timeout
.expires
= jiffies
+
265 (random32() % net
->ct
.sysctl_events_retry_timeout
);
266 add_timer(&ecache
->timeout
);
269 /* we've got the event delivered, now it's dying */
270 set_bit(IPS_DYING_BIT
, &ct
->status
);
271 spin_lock(&nf_conntrack_lock
);
272 hlist_nulls_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
273 spin_unlock(&nf_conntrack_lock
);
277 void nf_ct_insert_dying_list(struct nf_conn
*ct
)
279 struct net
*net
= nf_ct_net(ct
);
280 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
282 BUG_ON(ecache
== NULL
);
284 /* add this conntrack to the dying list */
285 spin_lock_bh(&nf_conntrack_lock
);
286 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
288 spin_unlock_bh(&nf_conntrack_lock
);
289 /* set a new timer to retry event delivery */
290 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
291 ecache
->timeout
.expires
= jiffies
+
292 (random32() % net
->ct
.sysctl_events_retry_timeout
);
293 add_timer(&ecache
->timeout
);
295 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list
);
297 static void death_by_timeout(unsigned long ul_conntrack
)
299 struct nf_conn
*ct
= (void *)ul_conntrack
;
300 struct nf_conn_tstamp
*tstamp
;
302 tstamp
= nf_conn_tstamp_find(ct
);
303 if (tstamp
&& tstamp
->stop
== 0)
304 tstamp
->stop
= ktime_to_ns(ktime_get_real());
306 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
307 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
308 /* destroy event was not delivered */
309 nf_ct_delete_from_lists(ct
);
310 nf_ct_insert_dying_list(ct
);
313 set_bit(IPS_DYING_BIT
, &ct
->status
);
314 nf_ct_delete_from_lists(ct
);
320 * - Caller must take a reference on returned object
321 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
323 * - Caller must lock nf_conntrack_lock before calling this function
325 static struct nf_conntrack_tuple_hash
*
326 ____nf_conntrack_find(struct net
*net
, u16 zone
,
327 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
329 struct nf_conntrack_tuple_hash
*h
;
330 struct hlist_nulls_node
*n
;
331 unsigned int bucket
= hash_bucket(hash
, net
);
333 /* Disable BHs the entire time since we normally need to disable them
334 * at least once for the stats anyway.
338 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
339 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
340 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
341 NF_CT_STAT_INC(net
, found
);
345 NF_CT_STAT_INC(net
, searched
);
348 * if the nulls value we got at the end of this lookup is
349 * not the expected one, we must restart lookup.
350 * We probably met an item that was moved to another chain.
352 if (get_nulls_value(n
) != bucket
) {
353 NF_CT_STAT_INC(net
, search_restart
);
361 struct nf_conntrack_tuple_hash
*
362 __nf_conntrack_find(struct net
*net
, u16 zone
,
363 const struct nf_conntrack_tuple
*tuple
)
365 return ____nf_conntrack_find(net
, zone
, tuple
,
366 hash_conntrack_raw(tuple
, zone
));
368 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
370 /* Find a connection corresponding to a tuple. */
371 static struct nf_conntrack_tuple_hash
*
372 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
373 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
375 struct nf_conntrack_tuple_hash
*h
;
380 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
382 ct
= nf_ct_tuplehash_to_ctrack(h
);
383 if (unlikely(nf_ct_is_dying(ct
) ||
384 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
387 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
388 nf_ct_zone(ct
) != zone
)) {
399 struct nf_conntrack_tuple_hash
*
400 nf_conntrack_find_get(struct net
*net
, u16 zone
,
401 const struct nf_conntrack_tuple
*tuple
)
403 return __nf_conntrack_find_get(net
, zone
, tuple
,
404 hash_conntrack_raw(tuple
, zone
));
406 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
408 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
410 unsigned int repl_hash
)
412 struct net
*net
= nf_ct_net(ct
);
414 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
415 &net
->ct
.hash
[hash
]);
416 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
417 &net
->ct
.hash
[repl_hash
]);
421 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
423 struct net
*net
= nf_ct_net(ct
);
424 unsigned int hash
, repl_hash
;
425 struct nf_conntrack_tuple_hash
*h
;
426 struct hlist_nulls_node
*n
;
429 zone
= nf_ct_zone(ct
);
430 hash
= hash_conntrack(net
, zone
,
431 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
432 repl_hash
= hash_conntrack(net
, zone
,
433 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
435 spin_lock_bh(&nf_conntrack_lock
);
437 /* See if there's one in the list already, including reverse */
438 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
439 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
441 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
443 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
444 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
446 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
449 add_timer(&ct
->timeout
);
450 nf_conntrack_get(&ct
->ct_general
);
451 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
452 NF_CT_STAT_INC(net
, insert
);
453 spin_unlock_bh(&nf_conntrack_lock
);
458 NF_CT_STAT_INC(net
, insert_failed
);
459 spin_unlock_bh(&nf_conntrack_lock
);
462 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
464 /* Confirm a connection given skb; places it in hash table */
466 __nf_conntrack_confirm(struct sk_buff
*skb
)
468 unsigned int hash
, repl_hash
;
469 struct nf_conntrack_tuple_hash
*h
;
471 struct nf_conn_help
*help
;
472 struct nf_conn_tstamp
*tstamp
;
473 struct hlist_nulls_node
*n
;
474 enum ip_conntrack_info ctinfo
;
478 ct
= nf_ct_get(skb
, &ctinfo
);
481 /* ipt_REJECT uses nf_conntrack_attach to attach related
482 ICMP/TCP RST packets in other direction. Actual packet
483 which created connection will be IP_CT_NEW or for an
484 expected connection, IP_CT_RELATED. */
485 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
488 zone
= nf_ct_zone(ct
);
489 /* reuse the hash saved before */
490 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
491 hash
= hash_bucket(hash
, net
);
492 repl_hash
= hash_conntrack(net
, zone
,
493 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
495 /* We're not in hash table, and we refuse to set up related
496 connections for unconfirmed conns. But packet copies and
497 REJECT will give spurious warnings here. */
498 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
500 /* No external references means no one else could have
502 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
503 pr_debug("Confirming conntrack %p\n", ct
);
505 spin_lock_bh(&nf_conntrack_lock
);
507 /* We have to check the DYING flag inside the lock to prevent
508 a race against nf_ct_get_next_corpse() possibly called from
509 user context, else we insert an already 'dead' hash, blocking
510 further use of that particular connection -JM */
512 if (unlikely(nf_ct_is_dying(ct
))) {
513 spin_unlock_bh(&nf_conntrack_lock
);
517 /* See if there's one in the list already, including reverse:
518 NAT could have grabbed it without realizing, since we're
519 not in the hash. If there is, we lost race. */
520 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
521 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
523 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
525 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
526 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
528 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
531 /* Remove from unconfirmed list */
532 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
534 /* Timer relative to confirmation time, not original
535 setting time, otherwise we'd get timer wrap in
536 weird delay cases. */
537 ct
->timeout
.expires
+= jiffies
;
538 add_timer(&ct
->timeout
);
539 atomic_inc(&ct
->ct_general
.use
);
540 ct
->status
|= IPS_CONFIRMED
;
542 /* set conntrack timestamp, if enabled. */
543 tstamp
= nf_conn_tstamp_find(ct
);
545 if (skb
->tstamp
.tv64
== 0)
546 __net_timestamp(skb
);
548 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
550 /* Since the lookup is lockless, hash insertion must be done after
551 * starting the timer and setting the CONFIRMED bit. The RCU barriers
552 * guarantee that no other CPU can find the conntrack before the above
553 * stores are visible.
555 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
556 NF_CT_STAT_INC(net
, insert
);
557 spin_unlock_bh(&nf_conntrack_lock
);
559 help
= nfct_help(ct
);
560 if (help
&& help
->helper
)
561 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
563 nf_conntrack_event_cache(master_ct(ct
) ?
564 IPCT_RELATED
: IPCT_NEW
, ct
);
568 NF_CT_STAT_INC(net
, insert_failed
);
569 spin_unlock_bh(&nf_conntrack_lock
);
572 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
574 /* Returns true if a connection correspondings to the tuple (required
577 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
578 const struct nf_conn
*ignored_conntrack
)
580 struct net
*net
= nf_ct_net(ignored_conntrack
);
581 struct nf_conntrack_tuple_hash
*h
;
582 struct hlist_nulls_node
*n
;
584 u16 zone
= nf_ct_zone(ignored_conntrack
);
585 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
587 /* Disable BHs the entire time since we need to disable them at
588 * least once for the stats anyway.
591 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
592 ct
= nf_ct_tuplehash_to_ctrack(h
);
593 if (ct
!= ignored_conntrack
&&
594 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
595 nf_ct_zone(ct
) == zone
) {
596 NF_CT_STAT_INC(net
, found
);
597 rcu_read_unlock_bh();
600 NF_CT_STAT_INC(net
, searched
);
602 rcu_read_unlock_bh();
606 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
608 #define NF_CT_EVICTION_RANGE 8
610 /* There's a small race here where we may free a just-assured
611 connection. Too bad: we're in trouble anyway. */
612 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
614 /* Use oldest entry, which is roughly LRU */
615 struct nf_conntrack_tuple_hash
*h
;
616 struct nf_conn
*ct
= NULL
, *tmp
;
617 struct hlist_nulls_node
*n
;
618 unsigned int i
, cnt
= 0;
622 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
623 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
625 tmp
= nf_ct_tuplehash_to_ctrack(h
);
626 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
632 if (likely(!nf_ct_is_dying(ct
) &&
633 atomic_inc_not_zero(&ct
->ct_general
.use
)))
639 if (cnt
>= NF_CT_EVICTION_RANGE
)
642 hash
= (hash
+ 1) % net
->ct
.htable_size
;
649 if (del_timer(&ct
->timeout
)) {
650 death_by_timeout((unsigned long)ct
);
651 /* Check if we indeed killed this entry. Reliable event
652 delivery may have inserted it into the dying list. */
653 if (test_bit(IPS_DYING_BIT
, &ct
->status
)) {
655 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
662 void init_nf_conntrack_hash_rnd(void)
667 * Why not initialize nf_conntrack_rnd in a "init()" function ?
668 * Because there isn't enough entropy when system initializing,
669 * and we initialize it as late as possible.
672 get_random_bytes(&rand
, sizeof(rand
));
674 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
677 static struct nf_conn
*
678 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
679 const struct nf_conntrack_tuple
*orig
,
680 const struct nf_conntrack_tuple
*repl
,
685 if (unlikely(!nf_conntrack_hash_rnd
)) {
686 init_nf_conntrack_hash_rnd();
687 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
688 hash
= hash_conntrack_raw(orig
, zone
);
691 /* We don't want any race condition at early drop stage */
692 atomic_inc(&net
->ct
.count
);
694 if (nf_conntrack_max
&&
695 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
696 if (!early_drop(net
, hash_bucket(hash
, net
))) {
697 atomic_dec(&net
->ct
.count
);
698 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
699 return ERR_PTR(-ENOMEM
);
704 * Do not use kmem_cache_zalloc(), as this cache uses
705 * SLAB_DESTROY_BY_RCU.
707 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
709 atomic_dec(&net
->ct
.count
);
710 return ERR_PTR(-ENOMEM
);
713 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
714 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
716 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
717 offsetof(struct nf_conn
, proto
) -
718 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
719 spin_lock_init(&ct
->lock
);
720 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
721 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
722 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
723 /* save hash for reusing when confirming */
724 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
725 /* Don't set timer yet: wait for confirmation */
726 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
727 write_pnet(&ct
->ct_net
, net
);
728 #ifdef CONFIG_NF_CONNTRACK_ZONES
730 struct nf_conntrack_zone
*nf_ct_zone
;
732 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
735 nf_ct_zone
->id
= zone
;
739 * changes to lookup keys must be done before setting refcnt to 1
742 atomic_set(&ct
->ct_general
.use
, 1);
745 #ifdef CONFIG_NF_CONNTRACK_ZONES
747 atomic_dec(&net
->ct
.count
);
748 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
749 return ERR_PTR(-ENOMEM
);
753 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
754 const struct nf_conntrack_tuple
*orig
,
755 const struct nf_conntrack_tuple
*repl
,
758 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
760 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
762 void nf_conntrack_free(struct nf_conn
*ct
)
764 struct net
*net
= nf_ct_net(ct
);
766 nf_ct_ext_destroy(ct
);
767 atomic_dec(&net
->ct
.count
);
769 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
771 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
773 /* Allocate a new conntrack: we return -ENOMEM if classification
774 failed due to stress. Otherwise it really is unclassifiable. */
775 static struct nf_conntrack_tuple_hash
*
776 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
777 const struct nf_conntrack_tuple
*tuple
,
778 struct nf_conntrack_l3proto
*l3proto
,
779 struct nf_conntrack_l4proto
*l4proto
,
781 unsigned int dataoff
, u32 hash
)
784 struct nf_conn_help
*help
;
785 struct nf_conntrack_tuple repl_tuple
;
786 struct nf_conntrack_ecache
*ecache
;
787 struct nf_conntrack_expect
*exp
;
788 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
789 struct nf_conn_timeout
*timeout_ext
;
790 unsigned int *timeouts
;
792 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
793 pr_debug("Can't invert tuple.\n");
797 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
800 return (struct nf_conntrack_tuple_hash
*)ct
;
802 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
804 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
806 timeouts
= l4proto
->get_timeouts(net
);
808 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
809 nf_conntrack_free(ct
);
810 pr_debug("init conntrack: can't track with proto module\n");
815 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
817 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
818 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
820 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
821 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
822 ecache
? ecache
->expmask
: 0,
825 spin_lock_bh(&nf_conntrack_lock
);
826 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
828 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
830 /* Welcome, Mr. Bond. We've been expecting you... */
831 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
832 ct
->master
= exp
->master
;
834 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
837 rcu_assign_pointer(help
->helper
, exp
->helper
);
840 #ifdef CONFIG_NF_CONNTRACK_MARK
841 ct
->mark
= exp
->master
->mark
;
843 #ifdef CONFIG_NF_CONNTRACK_SECMARK
844 ct
->secmark
= exp
->master
->secmark
;
846 nf_conntrack_get(&ct
->master
->ct_general
);
847 NF_CT_STAT_INC(net
, expect_new
);
849 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
850 NF_CT_STAT_INC(net
, new);
853 /* Overload tuple linked list to put us in unconfirmed list. */
854 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
855 &net
->ct
.unconfirmed
);
857 spin_unlock_bh(&nf_conntrack_lock
);
861 exp
->expectfn(ct
, exp
);
862 nf_ct_expect_put(exp
);
865 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
868 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
869 static inline struct nf_conn
*
870 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
872 unsigned int dataoff
,
875 struct nf_conntrack_l3proto
*l3proto
,
876 struct nf_conntrack_l4proto
*l4proto
,
878 enum ip_conntrack_info
*ctinfo
)
880 struct nf_conntrack_tuple tuple
;
881 struct nf_conntrack_tuple_hash
*h
;
883 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
886 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
887 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
889 pr_debug("resolve_normal_ct: Can't get tuple\n");
893 /* look for tuple match */
894 hash
= hash_conntrack_raw(&tuple
, zone
);
895 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
897 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
904 ct
= nf_ct_tuplehash_to_ctrack(h
);
906 /* It exists; we have (non-exclusive) reference. */
907 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
908 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
909 /* Please set reply bit if this packet OK */
912 /* Once we've had two way comms, always ESTABLISHED. */
913 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
914 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
915 *ctinfo
= IP_CT_ESTABLISHED
;
916 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
917 pr_debug("nf_conntrack_in: related packet for %p\n",
919 *ctinfo
= IP_CT_RELATED
;
921 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
926 skb
->nfct
= &ct
->ct_general
;
927 skb
->nfctinfo
= *ctinfo
;
932 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
935 struct nf_conn
*ct
, *tmpl
= NULL
;
936 enum ip_conntrack_info ctinfo
;
937 struct nf_conntrack_l3proto
*l3proto
;
938 struct nf_conntrack_l4proto
*l4proto
;
939 unsigned int *timeouts
;
940 unsigned int dataoff
;
946 /* Previously seen (loopback or untracked)? Ignore. */
947 tmpl
= (struct nf_conn
*)skb
->nfct
;
948 if (!nf_ct_is_template(tmpl
)) {
949 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
955 /* rcu_read_lock()ed by nf_hook_slow */
956 l3proto
= __nf_ct_l3proto_find(pf
);
957 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
958 &dataoff
, &protonum
);
960 pr_debug("not prepared to track yet or error occurred\n");
961 NF_CT_STAT_INC_ATOMIC(net
, error
);
962 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
967 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
969 /* It may be an special packet, error, unclean...
970 * inverse of the return code tells to the netfilter
971 * core what to do with the packet. */
972 if (l4proto
->error
!= NULL
) {
973 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
976 NF_CT_STAT_INC_ATOMIC(net
, error
);
977 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
981 /* ICMP[v6] protocol trackers may assign one conntrack. */
986 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
987 l3proto
, l4proto
, &set_reply
, &ctinfo
);
989 /* Not valid part of a connection */
990 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
996 /* Too stressed to deal. */
997 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1002 NF_CT_ASSERT(skb
->nfct
);
1004 /* Decide what timeout policy we want to apply to this flow. */
1005 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1007 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1009 /* Invalid: inverse of the return code tells
1010 * the netfilter core what to do */
1011 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1012 nf_conntrack_put(skb
->nfct
);
1014 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1015 if (ret
== -NF_DROP
)
1016 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1021 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1022 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1025 /* Special case: we have to repeat this hook, assign the
1026 * template again to this packet. We assume that this packet
1027 * has no conntrack assigned. This is used by nf_ct_tcp. */
1028 if (ret
== NF_REPEAT
)
1029 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1036 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1038 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1039 const struct nf_conntrack_tuple
*orig
)
1044 ret
= nf_ct_invert_tuple(inverse
, orig
,
1045 __nf_ct_l3proto_find(orig
->src
.l3num
),
1046 __nf_ct_l4proto_find(orig
->src
.l3num
,
1047 orig
->dst
.protonum
));
1051 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1053 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1054 implicitly racy: see __nf_conntrack_confirm */
1055 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1056 const struct nf_conntrack_tuple
*newreply
)
1058 struct nf_conn_help
*help
= nfct_help(ct
);
1060 /* Should be unconfirmed, so not in hash table yet */
1061 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1063 pr_debug("Altering reply tuple of %p to ", ct
);
1064 nf_ct_dump_tuple(newreply
);
1066 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1067 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1071 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1074 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1076 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1077 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1078 enum ip_conntrack_info ctinfo
,
1079 const struct sk_buff
*skb
,
1080 unsigned long extra_jiffies
,
1083 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1086 /* Only update if this is not a fixed timeout */
1087 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1090 /* If not in hash table, timer will not be active yet */
1091 if (!nf_ct_is_confirmed(ct
)) {
1092 ct
->timeout
.expires
= extra_jiffies
;
1094 unsigned long newtime
= jiffies
+ extra_jiffies
;
1096 /* Only update the timeout if the new timeout is at least
1097 HZ jiffies from the old timeout. Need del_timer for race
1098 avoidance (may already be dying). */
1099 if (newtime
- ct
->timeout
.expires
>= HZ
)
1100 mod_timer_pending(&ct
->timeout
, newtime
);
1105 struct nf_conn_counter
*acct
;
1107 acct
= nf_conn_acct_find(ct
);
1109 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1110 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1114 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1116 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1117 enum ip_conntrack_info ctinfo
,
1118 const struct sk_buff
*skb
,
1122 struct nf_conn_counter
*acct
;
1124 acct
= nf_conn_acct_find(ct
);
1126 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1127 atomic64_add(skb
->len
- skb_network_offset(skb
),
1128 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1132 if (del_timer(&ct
->timeout
)) {
1133 ct
->timeout
.function((unsigned long)ct
);
1138 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1140 #ifdef CONFIG_NF_CONNTRACK_ZONES
1141 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1142 .len
= sizeof(struct nf_conntrack_zone
),
1143 .align
= __alignof__(struct nf_conntrack_zone
),
1144 .id
= NF_CT_EXT_ZONE
,
1148 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1150 #include <linux/netfilter/nfnetlink.h>
1151 #include <linux/netfilter/nfnetlink_conntrack.h>
1152 #include <linux/mutex.h>
1154 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1155 * in ip_conntrack_core, since we don't want the protocols to autoload
1156 * or depend on ctnetlink */
1157 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1158 const struct nf_conntrack_tuple
*tuple
)
1160 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1161 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1162 goto nla_put_failure
;
1168 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1170 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1171 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1172 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1174 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1176 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1177 struct nf_conntrack_tuple
*t
)
1179 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1182 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1183 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1187 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1189 int nf_ct_port_nlattr_tuple_size(void)
1191 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1193 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1196 /* Used by ipt_REJECT and ip6t_REJECT. */
1197 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1200 enum ip_conntrack_info ctinfo
;
1202 /* This ICMP is in reverse direction to the packet which caused it */
1203 ct
= nf_ct_get(skb
, &ctinfo
);
1204 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1205 ctinfo
= IP_CT_RELATED_REPLY
;
1207 ctinfo
= IP_CT_RELATED
;
1209 /* Attach to new skbuff, and increment count */
1210 nskb
->nfct
= &ct
->ct_general
;
1211 nskb
->nfctinfo
= ctinfo
;
1212 nf_conntrack_get(nskb
->nfct
);
1215 /* Bring out ya dead! */
1216 static struct nf_conn
*
1217 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1218 void *data
, unsigned int *bucket
)
1220 struct nf_conntrack_tuple_hash
*h
;
1222 struct hlist_nulls_node
*n
;
1224 spin_lock_bh(&nf_conntrack_lock
);
1225 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1226 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1227 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1229 ct
= nf_ct_tuplehash_to_ctrack(h
);
1234 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1235 ct
= nf_ct_tuplehash_to_ctrack(h
);
1237 set_bit(IPS_DYING_BIT
, &ct
->status
);
1239 spin_unlock_bh(&nf_conntrack_lock
);
1242 atomic_inc(&ct
->ct_general
.use
);
1243 spin_unlock_bh(&nf_conntrack_lock
);
1247 void nf_ct_iterate_cleanup(struct net
*net
,
1248 int (*iter
)(struct nf_conn
*i
, void *data
),
1252 unsigned int bucket
= 0;
1254 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1255 /* Time to push up daises... */
1256 if (del_timer(&ct
->timeout
))
1257 death_by_timeout((unsigned long)ct
);
1258 /* ... else the timer will get him soon. */
1263 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1265 struct __nf_ct_flush_report
{
1270 static int kill_report(struct nf_conn
*i
, void *data
)
1272 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1273 struct nf_conn_tstamp
*tstamp
;
1275 tstamp
= nf_conn_tstamp_find(i
);
1276 if (tstamp
&& tstamp
->stop
== 0)
1277 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1279 /* If we fail to deliver the event, death_by_timeout() will retry */
1280 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1281 fr
->pid
, fr
->report
) < 0)
1284 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1285 set_bit(IPS_DYING_BIT
, &i
->status
);
1289 static int kill_all(struct nf_conn
*i
, void *data
)
1294 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1296 if (is_vmalloc_addr(hash
))
1299 free_pages((unsigned long)hash
,
1300 get_order(sizeof(struct hlist_head
) * size
));
1302 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1304 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1306 struct __nf_ct_flush_report fr
= {
1310 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1312 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1314 static void nf_ct_release_dying_list(struct net
*net
)
1316 struct nf_conntrack_tuple_hash
*h
;
1318 struct hlist_nulls_node
*n
;
1320 spin_lock_bh(&nf_conntrack_lock
);
1321 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1322 ct
= nf_ct_tuplehash_to_ctrack(h
);
1323 /* never fails to remove them, no listeners at this point */
1326 spin_unlock_bh(&nf_conntrack_lock
);
1329 static int untrack_refs(void)
1333 for_each_possible_cpu(cpu
) {
1334 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1336 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1341 static void nf_conntrack_cleanup_init_net(void)
1343 while (untrack_refs() > 0)
1346 #ifdef CONFIG_NF_CONNTRACK_ZONES
1347 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1351 static void nf_conntrack_cleanup_net(struct net
*net
)
1354 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1355 nf_ct_release_dying_list(net
);
1356 if (atomic_read(&net
->ct
.count
) != 0) {
1358 goto i_see_dead_people
;
1361 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1362 nf_conntrack_helper_fini(net
);
1363 nf_conntrack_timeout_fini(net
);
1364 nf_conntrack_ecache_fini(net
);
1365 nf_conntrack_tstamp_fini(net
);
1366 nf_conntrack_acct_fini(net
);
1367 nf_conntrack_expect_fini(net
);
1368 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1369 kfree(net
->ct
.slabname
);
1370 free_percpu(net
->ct
.stat
);
1373 /* Mishearing the voices in his head, our hero wonders how he's
1374 supposed to kill the mall. */
1375 void nf_conntrack_cleanup(struct net
*net
)
1377 if (net_eq(net
, &init_net
))
1378 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1380 /* This makes sure all current packets have passed through
1381 netfilter framework. Roll on, two-stage module
1384 nf_conntrack_proto_fini(net
);
1385 nf_conntrack_cleanup_net(net
);
1387 if (net_eq(net
, &init_net
)) {
1388 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1389 nf_conntrack_cleanup_init_net();
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 hashsize
= simple_strtoul(val
, NULL
, 0);
1436 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1440 /* Lookups in the old hash might happen in parallel, which means we
1441 * might get false negatives during connection lookup. New connections
1442 * created because of a false negative won't make it into the hash
1443 * though since that required taking the lock.
1445 spin_lock_bh(&nf_conntrack_lock
);
1446 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1447 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1448 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1449 struct nf_conntrack_tuple_hash
, hnnode
);
1450 ct
= nf_ct_tuplehash_to_ctrack(h
);
1451 hlist_nulls_del_rcu(&h
->hnnode
);
1452 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1454 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1457 old_size
= init_net
.ct
.htable_size
;
1458 old_hash
= init_net
.ct
.hash
;
1460 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1461 init_net
.ct
.hash
= hash
;
1462 spin_unlock_bh(&nf_conntrack_lock
);
1464 nf_ct_free_hashtable(old_hash
, old_size
);
1467 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1469 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1470 &nf_conntrack_htable_size
, 0600);
1472 void nf_ct_untracked_status_or(unsigned long bits
)
1476 for_each_possible_cpu(cpu
)
1477 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1479 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1481 static int nf_conntrack_init_init_net(void)
1486 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1487 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1488 if (!nf_conntrack_htable_size
) {
1489 nf_conntrack_htable_size
1490 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1491 / sizeof(struct hlist_head
));
1492 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1493 nf_conntrack_htable_size
= 16384;
1494 if (nf_conntrack_htable_size
< 32)
1495 nf_conntrack_htable_size
= 32;
1497 /* Use a max. factor of four by default to get the same max as
1498 * with the old struct list_heads. When a table size is given
1499 * we use the old value of 8 to avoid reducing the max.
1503 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1505 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1506 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1508 #ifdef CONFIG_NF_CONNTRACK_ZONES
1509 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1513 /* Set up fake conntrack: to never be deleted, not in any hashes */
1514 for_each_possible_cpu(cpu
) {
1515 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1516 write_pnet(&ct
->ct_net
, &init_net
);
1517 atomic_set(&ct
->ct_general
.use
, 1);
1519 /* - and look it like as a confirmed connection */
1520 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1523 #ifdef CONFIG_NF_CONNTRACK_ZONES
1530 * We need to use special "null" values, not used in hash table
1532 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1533 #define DYING_NULLS_VAL ((1<<30)+1)
1535 static int nf_conntrack_init_net(struct net
*net
)
1539 atomic_set(&net
->ct
.count
, 0);
1540 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1541 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1542 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1543 if (!net
->ct
.stat
) {
1548 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1549 if (!net
->ct
.slabname
) {
1554 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1555 sizeof(struct nf_conn
), 0,
1556 SLAB_DESTROY_BY_RCU
, NULL
);
1557 if (!net
->ct
.nf_conntrack_cachep
) {
1558 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1563 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1564 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1565 if (!net
->ct
.hash
) {
1567 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1570 ret
= nf_conntrack_expect_init(net
);
1573 ret
= nf_conntrack_acct_init(net
);
1576 ret
= nf_conntrack_tstamp_init(net
);
1579 ret
= nf_conntrack_ecache_init(net
);
1582 ret
= nf_conntrack_timeout_init(net
);
1585 ret
= nf_conntrack_helper_init(net
);
1590 nf_conntrack_timeout_fini(net
);
1592 nf_conntrack_ecache_fini(net
);
1594 nf_conntrack_tstamp_fini(net
);
1596 nf_conntrack_acct_fini(net
);
1598 nf_conntrack_expect_fini(net
);
1600 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1602 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1604 kfree(net
->ct
.slabname
);
1606 free_percpu(net
->ct
.stat
);
1611 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1612 enum ip_conntrack_dir dir
,
1614 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1616 int nf_conntrack_init(struct net
*net
)
1620 if (net_eq(net
, &init_net
)) {
1621 ret
= nf_conntrack_init_init_net();
1625 ret
= nf_conntrack_proto_init(net
);
1628 ret
= nf_conntrack_init_net(net
);
1632 if (net_eq(net
, &init_net
)) {
1633 /* For use by REJECT target */
1634 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1635 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1637 /* Howto get NAT offsets */
1638 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1643 nf_conntrack_proto_fini(net
);
1645 if (net_eq(net
, &init_net
))
1646 nf_conntrack_cleanup_init_net();