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 or dying list.*/
225 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
226 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
228 NF_CT_STAT_INC(net
, delete);
229 spin_unlock_bh(&nf_conntrack_lock
);
232 nf_ct_put(ct
->master
);
234 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
235 nf_conntrack_free(ct
);
238 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
240 struct net
*net
= nf_ct_net(ct
);
242 nf_ct_helper_destroy(ct
);
243 spin_lock_bh(&nf_conntrack_lock
);
244 /* Inside lock so preempt is disabled on module removal path.
245 * Otherwise we can get spurious warnings. */
246 NF_CT_STAT_INC(net
, delete_list
);
247 clean_from_lists(ct
);
248 /* add this conntrack to the dying list */
249 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
251 spin_unlock_bh(&nf_conntrack_lock
);
253 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
255 static void death_by_event(unsigned long ul_conntrack
)
257 struct nf_conn
*ct
= (void *)ul_conntrack
;
258 struct net
*net
= nf_ct_net(ct
);
259 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
261 BUG_ON(ecache
== NULL
);
263 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
264 /* bad luck, let's retry again */
265 ecache
->timeout
.expires
= jiffies
+
266 (random32() % net
->ct
.sysctl_events_retry_timeout
);
267 add_timer(&ecache
->timeout
);
270 /* we've got the event delivered, now it's dying */
271 set_bit(IPS_DYING_BIT
, &ct
->status
);
275 void nf_ct_dying_timeout(struct nf_conn
*ct
)
277 struct net
*net
= nf_ct_net(ct
);
278 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
280 BUG_ON(ecache
== NULL
);
282 /* set a new timer to retry event delivery */
283 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
284 ecache
->timeout
.expires
= jiffies
+
285 (random32() % net
->ct
.sysctl_events_retry_timeout
);
286 add_timer(&ecache
->timeout
);
288 EXPORT_SYMBOL_GPL(nf_ct_dying_timeout
);
290 static void death_by_timeout(unsigned long ul_conntrack
)
292 struct nf_conn
*ct
= (void *)ul_conntrack
;
293 struct nf_conn_tstamp
*tstamp
;
295 tstamp
= nf_conn_tstamp_find(ct
);
296 if (tstamp
&& tstamp
->stop
== 0)
297 tstamp
->stop
= ktime_to_ns(ktime_get_real());
299 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
300 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
301 /* destroy event was not delivered */
302 nf_ct_delete_from_lists(ct
);
303 nf_ct_dying_timeout(ct
);
306 set_bit(IPS_DYING_BIT
, &ct
->status
);
307 nf_ct_delete_from_lists(ct
);
313 * - Caller must take a reference on returned object
314 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
316 * - Caller must lock nf_conntrack_lock before calling this function
318 static struct nf_conntrack_tuple_hash
*
319 ____nf_conntrack_find(struct net
*net
, u16 zone
,
320 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
322 struct nf_conntrack_tuple_hash
*h
;
323 struct hlist_nulls_node
*n
;
324 unsigned int bucket
= hash_bucket(hash
, net
);
326 /* Disable BHs the entire time since we normally need to disable them
327 * at least once for the stats anyway.
331 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
332 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
333 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
334 NF_CT_STAT_INC(net
, found
);
338 NF_CT_STAT_INC(net
, searched
);
341 * if the nulls value we got at the end of this lookup is
342 * not the expected one, we must restart lookup.
343 * We probably met an item that was moved to another chain.
345 if (get_nulls_value(n
) != bucket
) {
346 NF_CT_STAT_INC(net
, search_restart
);
354 struct nf_conntrack_tuple_hash
*
355 __nf_conntrack_find(struct net
*net
, u16 zone
,
356 const struct nf_conntrack_tuple
*tuple
)
358 return ____nf_conntrack_find(net
, zone
, tuple
,
359 hash_conntrack_raw(tuple
, zone
));
361 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
363 /* Find a connection corresponding to a tuple. */
364 static struct nf_conntrack_tuple_hash
*
365 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
366 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
368 struct nf_conntrack_tuple_hash
*h
;
373 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
375 ct
= nf_ct_tuplehash_to_ctrack(h
);
376 if (unlikely(nf_ct_is_dying(ct
) ||
377 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
380 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
381 nf_ct_zone(ct
) != zone
)) {
392 struct nf_conntrack_tuple_hash
*
393 nf_conntrack_find_get(struct net
*net
, u16 zone
,
394 const struct nf_conntrack_tuple
*tuple
)
396 return __nf_conntrack_find_get(net
, zone
, tuple
,
397 hash_conntrack_raw(tuple
, zone
));
399 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
401 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
403 unsigned int repl_hash
)
405 struct net
*net
= nf_ct_net(ct
);
407 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
408 &net
->ct
.hash
[hash
]);
409 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
410 &net
->ct
.hash
[repl_hash
]);
414 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
416 struct net
*net
= nf_ct_net(ct
);
417 unsigned int hash
, repl_hash
;
418 struct nf_conntrack_tuple_hash
*h
;
419 struct hlist_nulls_node
*n
;
422 zone
= nf_ct_zone(ct
);
423 hash
= hash_conntrack(net
, zone
,
424 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
425 repl_hash
= hash_conntrack(net
, zone
,
426 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
428 spin_lock_bh(&nf_conntrack_lock
);
430 /* See if there's one in the list already, including reverse */
431 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
432 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
434 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
436 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
437 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
439 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
442 add_timer(&ct
->timeout
);
443 nf_conntrack_get(&ct
->ct_general
);
444 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
445 NF_CT_STAT_INC(net
, insert
);
446 spin_unlock_bh(&nf_conntrack_lock
);
451 NF_CT_STAT_INC(net
, insert_failed
);
452 spin_unlock_bh(&nf_conntrack_lock
);
455 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
457 /* Confirm a connection given skb; places it in hash table */
459 __nf_conntrack_confirm(struct sk_buff
*skb
)
461 unsigned int hash
, repl_hash
;
462 struct nf_conntrack_tuple_hash
*h
;
464 struct nf_conn_help
*help
;
465 struct nf_conn_tstamp
*tstamp
;
466 struct hlist_nulls_node
*n
;
467 enum ip_conntrack_info ctinfo
;
471 ct
= nf_ct_get(skb
, &ctinfo
);
474 /* ipt_REJECT uses nf_conntrack_attach to attach related
475 ICMP/TCP RST packets in other direction. Actual packet
476 which created connection will be IP_CT_NEW or for an
477 expected connection, IP_CT_RELATED. */
478 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
481 zone
= nf_ct_zone(ct
);
482 /* reuse the hash saved before */
483 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
484 hash
= hash_bucket(hash
, net
);
485 repl_hash
= hash_conntrack(net
, zone
,
486 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
488 /* We're not in hash table, and we refuse to set up related
489 connections for unconfirmed conns. But packet copies and
490 REJECT will give spurious warnings here. */
491 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
493 /* No external references means no one else could have
495 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
496 pr_debug("Confirming conntrack %p\n", ct
);
498 spin_lock_bh(&nf_conntrack_lock
);
500 /* We have to check the DYING flag inside the lock to prevent
501 a race against nf_ct_get_next_corpse() possibly called from
502 user context, else we insert an already 'dead' hash, blocking
503 further use of that particular connection -JM */
505 if (unlikely(nf_ct_is_dying(ct
))) {
506 spin_unlock_bh(&nf_conntrack_lock
);
510 /* See if there's one in the list already, including reverse:
511 NAT could have grabbed it without realizing, since we're
512 not in the hash. If there is, we lost race. */
513 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
514 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
516 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
518 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
519 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
521 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
524 /* Remove from unconfirmed list */
525 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
527 /* Timer relative to confirmation time, not original
528 setting time, otherwise we'd get timer wrap in
529 weird delay cases. */
530 ct
->timeout
.expires
+= jiffies
;
531 add_timer(&ct
->timeout
);
532 atomic_inc(&ct
->ct_general
.use
);
533 ct
->status
|= IPS_CONFIRMED
;
535 /* set conntrack timestamp, if enabled. */
536 tstamp
= nf_conn_tstamp_find(ct
);
538 if (skb
->tstamp
.tv64
== 0)
539 __net_timestamp(skb
);
541 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
543 /* Since the lookup is lockless, hash insertion must be done after
544 * starting the timer and setting the CONFIRMED bit. The RCU barriers
545 * guarantee that no other CPU can find the conntrack before the above
546 * stores are visible.
548 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
549 NF_CT_STAT_INC(net
, insert
);
550 spin_unlock_bh(&nf_conntrack_lock
);
552 help
= nfct_help(ct
);
553 if (help
&& help
->helper
)
554 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
556 nf_conntrack_event_cache(master_ct(ct
) ?
557 IPCT_RELATED
: IPCT_NEW
, ct
);
561 NF_CT_STAT_INC(net
, insert_failed
);
562 spin_unlock_bh(&nf_conntrack_lock
);
565 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
567 /* Returns true if a connection correspondings to the tuple (required
570 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
571 const struct nf_conn
*ignored_conntrack
)
573 struct net
*net
= nf_ct_net(ignored_conntrack
);
574 struct nf_conntrack_tuple_hash
*h
;
575 struct hlist_nulls_node
*n
;
577 u16 zone
= nf_ct_zone(ignored_conntrack
);
578 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
580 /* Disable BHs the entire time since we need to disable them at
581 * least once for the stats anyway.
584 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
585 ct
= nf_ct_tuplehash_to_ctrack(h
);
586 if (ct
!= ignored_conntrack
&&
587 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
588 nf_ct_zone(ct
) == zone
) {
589 NF_CT_STAT_INC(net
, found
);
590 rcu_read_unlock_bh();
593 NF_CT_STAT_INC(net
, searched
);
595 rcu_read_unlock_bh();
599 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
601 #define NF_CT_EVICTION_RANGE 8
603 /* There's a small race here where we may free a just-assured
604 connection. Too bad: we're in trouble anyway. */
605 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
607 /* Use oldest entry, which is roughly LRU */
608 struct nf_conntrack_tuple_hash
*h
;
609 struct nf_conn
*ct
= NULL
, *tmp
;
610 struct hlist_nulls_node
*n
;
611 unsigned int i
, cnt
= 0;
615 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
616 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
618 tmp
= nf_ct_tuplehash_to_ctrack(h
);
619 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
625 if (likely(!nf_ct_is_dying(ct
) &&
626 atomic_inc_not_zero(&ct
->ct_general
.use
)))
632 if (cnt
>= NF_CT_EVICTION_RANGE
)
635 hash
= (hash
+ 1) % net
->ct
.htable_size
;
642 if (del_timer(&ct
->timeout
)) {
643 death_by_timeout((unsigned long)ct
);
644 /* Check if we indeed killed this entry. Reliable event
645 delivery may have inserted it into the dying list. */
646 if (test_bit(IPS_DYING_BIT
, &ct
->status
)) {
648 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
655 void init_nf_conntrack_hash_rnd(void)
660 * Why not initialize nf_conntrack_rnd in a "init()" function ?
661 * Because there isn't enough entropy when system initializing,
662 * and we initialize it as late as possible.
665 get_random_bytes(&rand
, sizeof(rand
));
667 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
670 static struct nf_conn
*
671 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
672 const struct nf_conntrack_tuple
*orig
,
673 const struct nf_conntrack_tuple
*repl
,
678 if (unlikely(!nf_conntrack_hash_rnd
)) {
679 init_nf_conntrack_hash_rnd();
680 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
681 hash
= hash_conntrack_raw(orig
, zone
);
684 /* We don't want any race condition at early drop stage */
685 atomic_inc(&net
->ct
.count
);
687 if (nf_conntrack_max
&&
688 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
689 if (!early_drop(net
, hash_bucket(hash
, net
))) {
690 atomic_dec(&net
->ct
.count
);
691 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
692 return ERR_PTR(-ENOMEM
);
697 * Do not use kmem_cache_zalloc(), as this cache uses
698 * SLAB_DESTROY_BY_RCU.
700 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
702 atomic_dec(&net
->ct
.count
);
703 return ERR_PTR(-ENOMEM
);
706 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
707 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
709 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
710 offsetof(struct nf_conn
, proto
) -
711 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
712 spin_lock_init(&ct
->lock
);
713 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
714 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
715 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
716 /* save hash for reusing when confirming */
717 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
718 /* Don't set timer yet: wait for confirmation */
719 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
720 write_pnet(&ct
->ct_net
, net
);
721 #ifdef CONFIG_NF_CONNTRACK_ZONES
723 struct nf_conntrack_zone
*nf_ct_zone
;
725 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
728 nf_ct_zone
->id
= zone
;
732 * changes to lookup keys must be done before setting refcnt to 1
735 atomic_set(&ct
->ct_general
.use
, 1);
738 #ifdef CONFIG_NF_CONNTRACK_ZONES
740 atomic_dec(&net
->ct
.count
);
741 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
742 return ERR_PTR(-ENOMEM
);
746 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
747 const struct nf_conntrack_tuple
*orig
,
748 const struct nf_conntrack_tuple
*repl
,
751 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
753 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
755 void nf_conntrack_free(struct nf_conn
*ct
)
757 struct net
*net
= nf_ct_net(ct
);
759 nf_ct_ext_destroy(ct
);
760 atomic_dec(&net
->ct
.count
);
762 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
764 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
766 /* Allocate a new conntrack: we return -ENOMEM if classification
767 failed due to stress. Otherwise it really is unclassifiable. */
768 static struct nf_conntrack_tuple_hash
*
769 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
770 const struct nf_conntrack_tuple
*tuple
,
771 struct nf_conntrack_l3proto
*l3proto
,
772 struct nf_conntrack_l4proto
*l4proto
,
774 unsigned int dataoff
, u32 hash
)
777 struct nf_conn_help
*help
;
778 struct nf_conntrack_tuple repl_tuple
;
779 struct nf_conntrack_ecache
*ecache
;
780 struct nf_conntrack_expect
*exp
;
781 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
782 struct nf_conn_timeout
*timeout_ext
;
783 unsigned int *timeouts
;
785 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
786 pr_debug("Can't invert tuple.\n");
790 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
793 return (struct nf_conntrack_tuple_hash
*)ct
;
795 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
797 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
799 timeouts
= l4proto
->get_timeouts(net
);
801 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
802 nf_conntrack_free(ct
);
803 pr_debug("init conntrack: can't track with proto module\n");
808 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
810 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
811 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
813 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
814 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
815 ecache
? ecache
->expmask
: 0,
818 spin_lock_bh(&nf_conntrack_lock
);
819 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
821 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
823 /* Welcome, Mr. Bond. We've been expecting you... */
824 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
825 ct
->master
= exp
->master
;
827 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
830 rcu_assign_pointer(help
->helper
, exp
->helper
);
833 #ifdef CONFIG_NF_CONNTRACK_MARK
834 ct
->mark
= exp
->master
->mark
;
836 #ifdef CONFIG_NF_CONNTRACK_SECMARK
837 ct
->secmark
= exp
->master
->secmark
;
839 nf_conntrack_get(&ct
->master
->ct_general
);
840 NF_CT_STAT_INC(net
, expect_new
);
842 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
843 NF_CT_STAT_INC(net
, new);
846 /* Overload tuple linked list to put us in unconfirmed list. */
847 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
848 &net
->ct
.unconfirmed
);
850 spin_unlock_bh(&nf_conntrack_lock
);
854 exp
->expectfn(ct
, exp
);
855 nf_ct_expect_put(exp
);
858 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
861 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
862 static inline struct nf_conn
*
863 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
865 unsigned int dataoff
,
868 struct nf_conntrack_l3proto
*l3proto
,
869 struct nf_conntrack_l4proto
*l4proto
,
871 enum ip_conntrack_info
*ctinfo
)
873 struct nf_conntrack_tuple tuple
;
874 struct nf_conntrack_tuple_hash
*h
;
876 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
879 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
880 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
882 pr_debug("resolve_normal_ct: Can't get tuple\n");
886 /* look for tuple match */
887 hash
= hash_conntrack_raw(&tuple
, zone
);
888 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
890 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
897 ct
= nf_ct_tuplehash_to_ctrack(h
);
899 /* It exists; we have (non-exclusive) reference. */
900 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
901 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
902 /* Please set reply bit if this packet OK */
905 /* Once we've had two way comms, always ESTABLISHED. */
906 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
907 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
908 *ctinfo
= IP_CT_ESTABLISHED
;
909 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
910 pr_debug("nf_conntrack_in: related packet for %p\n",
912 *ctinfo
= IP_CT_RELATED
;
914 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
919 skb
->nfct
= &ct
->ct_general
;
920 skb
->nfctinfo
= *ctinfo
;
925 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
928 struct nf_conn
*ct
, *tmpl
= NULL
;
929 enum ip_conntrack_info ctinfo
;
930 struct nf_conntrack_l3proto
*l3proto
;
931 struct nf_conntrack_l4proto
*l4proto
;
932 unsigned int *timeouts
;
933 unsigned int dataoff
;
939 /* Previously seen (loopback or untracked)? Ignore. */
940 tmpl
= (struct nf_conn
*)skb
->nfct
;
941 if (!nf_ct_is_template(tmpl
)) {
942 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
948 /* rcu_read_lock()ed by nf_hook_slow */
949 l3proto
= __nf_ct_l3proto_find(pf
);
950 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
951 &dataoff
, &protonum
);
953 pr_debug("not prepared to track yet or error occurred\n");
954 NF_CT_STAT_INC_ATOMIC(net
, error
);
955 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
960 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
962 /* It may be an special packet, error, unclean...
963 * inverse of the return code tells to the netfilter
964 * core what to do with the packet. */
965 if (l4proto
->error
!= NULL
) {
966 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
969 NF_CT_STAT_INC_ATOMIC(net
, error
);
970 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
974 /* ICMP[v6] protocol trackers may assign one conntrack. */
979 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
980 l3proto
, l4proto
, &set_reply
, &ctinfo
);
982 /* Not valid part of a connection */
983 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
989 /* Too stressed to deal. */
990 NF_CT_STAT_INC_ATOMIC(net
, drop
);
995 NF_CT_ASSERT(skb
->nfct
);
997 /* Decide what timeout policy we want to apply to this flow. */
998 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1000 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1002 /* Invalid: inverse of the return code tells
1003 * the netfilter core what to do */
1004 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1005 nf_conntrack_put(skb
->nfct
);
1007 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1008 if (ret
== -NF_DROP
)
1009 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1014 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1015 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1018 /* Special case: we have to repeat this hook, assign the
1019 * template again to this packet. We assume that this packet
1020 * has no conntrack assigned. This is used by nf_ct_tcp. */
1021 if (ret
== NF_REPEAT
)
1022 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1029 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1031 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1032 const struct nf_conntrack_tuple
*orig
)
1037 ret
= nf_ct_invert_tuple(inverse
, orig
,
1038 __nf_ct_l3proto_find(orig
->src
.l3num
),
1039 __nf_ct_l4proto_find(orig
->src
.l3num
,
1040 orig
->dst
.protonum
));
1044 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1046 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1047 implicitly racy: see __nf_conntrack_confirm */
1048 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1049 const struct nf_conntrack_tuple
*newreply
)
1051 struct nf_conn_help
*help
= nfct_help(ct
);
1053 /* Should be unconfirmed, so not in hash table yet */
1054 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1056 pr_debug("Altering reply tuple of %p to ", ct
);
1057 nf_ct_dump_tuple(newreply
);
1059 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1060 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1064 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1067 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1069 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1070 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1071 enum ip_conntrack_info ctinfo
,
1072 const struct sk_buff
*skb
,
1073 unsigned long extra_jiffies
,
1076 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1079 /* Only update if this is not a fixed timeout */
1080 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1083 /* If not in hash table, timer will not be active yet */
1084 if (!nf_ct_is_confirmed(ct
)) {
1085 ct
->timeout
.expires
= extra_jiffies
;
1087 unsigned long newtime
= jiffies
+ extra_jiffies
;
1089 /* Only update the timeout if the new timeout is at least
1090 HZ jiffies from the old timeout. Need del_timer for race
1091 avoidance (may already be dying). */
1092 if (newtime
- ct
->timeout
.expires
>= HZ
)
1093 mod_timer_pending(&ct
->timeout
, newtime
);
1098 struct nf_conn_counter
*acct
;
1100 acct
= nf_conn_acct_find(ct
);
1102 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1103 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1107 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1109 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1110 enum ip_conntrack_info ctinfo
,
1111 const struct sk_buff
*skb
,
1115 struct nf_conn_counter
*acct
;
1117 acct
= nf_conn_acct_find(ct
);
1119 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1120 atomic64_add(skb
->len
- skb_network_offset(skb
),
1121 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1125 if (del_timer(&ct
->timeout
)) {
1126 ct
->timeout
.function((unsigned long)ct
);
1131 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1133 #ifdef CONFIG_NF_CONNTRACK_ZONES
1134 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1135 .len
= sizeof(struct nf_conntrack_zone
),
1136 .align
= __alignof__(struct nf_conntrack_zone
),
1137 .id
= NF_CT_EXT_ZONE
,
1141 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1143 #include <linux/netfilter/nfnetlink.h>
1144 #include <linux/netfilter/nfnetlink_conntrack.h>
1145 #include <linux/mutex.h>
1147 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1148 * in ip_conntrack_core, since we don't want the protocols to autoload
1149 * or depend on ctnetlink */
1150 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1151 const struct nf_conntrack_tuple
*tuple
)
1153 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1154 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1155 goto nla_put_failure
;
1161 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1163 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1164 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1165 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1167 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1169 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1170 struct nf_conntrack_tuple
*t
)
1172 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1175 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1176 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1180 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1182 int nf_ct_port_nlattr_tuple_size(void)
1184 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1186 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1189 /* Used by ipt_REJECT and ip6t_REJECT. */
1190 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1193 enum ip_conntrack_info ctinfo
;
1195 /* This ICMP is in reverse direction to the packet which caused it */
1196 ct
= nf_ct_get(skb
, &ctinfo
);
1197 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1198 ctinfo
= IP_CT_RELATED_REPLY
;
1200 ctinfo
= IP_CT_RELATED
;
1202 /* Attach to new skbuff, and increment count */
1203 nskb
->nfct
= &ct
->ct_general
;
1204 nskb
->nfctinfo
= ctinfo
;
1205 nf_conntrack_get(nskb
->nfct
);
1208 /* Bring out ya dead! */
1209 static struct nf_conn
*
1210 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1211 void *data
, unsigned int *bucket
)
1213 struct nf_conntrack_tuple_hash
*h
;
1215 struct hlist_nulls_node
*n
;
1217 spin_lock_bh(&nf_conntrack_lock
);
1218 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1219 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1220 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1222 ct
= nf_ct_tuplehash_to_ctrack(h
);
1227 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1228 ct
= nf_ct_tuplehash_to_ctrack(h
);
1230 set_bit(IPS_DYING_BIT
, &ct
->status
);
1232 spin_unlock_bh(&nf_conntrack_lock
);
1235 atomic_inc(&ct
->ct_general
.use
);
1236 spin_unlock_bh(&nf_conntrack_lock
);
1240 void nf_ct_iterate_cleanup(struct net
*net
,
1241 int (*iter
)(struct nf_conn
*i
, void *data
),
1245 unsigned int bucket
= 0;
1247 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1248 /* Time to push up daises... */
1249 if (del_timer(&ct
->timeout
))
1250 death_by_timeout((unsigned long)ct
);
1251 /* ... else the timer will get him soon. */
1256 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1258 struct __nf_ct_flush_report
{
1263 static int kill_report(struct nf_conn
*i
, void *data
)
1265 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1266 struct nf_conn_tstamp
*tstamp
;
1268 tstamp
= nf_conn_tstamp_find(i
);
1269 if (tstamp
&& tstamp
->stop
== 0)
1270 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1272 /* If we fail to deliver the event, death_by_timeout() will retry */
1273 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1274 fr
->pid
, fr
->report
) < 0)
1277 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1278 set_bit(IPS_DYING_BIT
, &i
->status
);
1282 static int kill_all(struct nf_conn
*i
, void *data
)
1287 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1289 if (is_vmalloc_addr(hash
))
1292 free_pages((unsigned long)hash
,
1293 get_order(sizeof(struct hlist_head
) * size
));
1295 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1297 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1299 struct __nf_ct_flush_report fr
= {
1303 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1305 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1307 static void nf_ct_release_dying_list(struct net
*net
)
1309 struct nf_conntrack_tuple_hash
*h
;
1311 struct hlist_nulls_node
*n
;
1313 spin_lock_bh(&nf_conntrack_lock
);
1314 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1315 ct
= nf_ct_tuplehash_to_ctrack(h
);
1316 /* never fails to remove them, no listeners at this point */
1319 spin_unlock_bh(&nf_conntrack_lock
);
1322 static int untrack_refs(void)
1326 for_each_possible_cpu(cpu
) {
1327 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1329 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1334 static void nf_conntrack_cleanup_init_net(void)
1336 while (untrack_refs() > 0)
1339 #ifdef CONFIG_NF_CONNTRACK_ZONES
1340 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1344 static void nf_conntrack_cleanup_net(struct net
*net
)
1347 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1348 nf_ct_release_dying_list(net
);
1349 if (atomic_read(&net
->ct
.count
) != 0) {
1351 goto i_see_dead_people
;
1354 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1355 nf_conntrack_helper_fini(net
);
1356 nf_conntrack_timeout_fini(net
);
1357 nf_conntrack_ecache_fini(net
);
1358 nf_conntrack_tstamp_fini(net
);
1359 nf_conntrack_acct_fini(net
);
1360 nf_conntrack_expect_fini(net
);
1361 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1362 kfree(net
->ct
.slabname
);
1363 free_percpu(net
->ct
.stat
);
1366 /* Mishearing the voices in his head, our hero wonders how he's
1367 supposed to kill the mall. */
1368 void nf_conntrack_cleanup(struct net
*net
)
1370 if (net_eq(net
, &init_net
))
1371 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1373 /* This makes sure all current packets have passed through
1374 netfilter framework. Roll on, two-stage module
1377 nf_conntrack_proto_fini(net
);
1378 nf_conntrack_cleanup_net(net
);
1380 if (net_eq(net
, &init_net
)) {
1381 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1382 nf_conntrack_cleanup_init_net();
1386 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1388 struct hlist_nulls_head
*hash
;
1389 unsigned int nr_slots
, i
;
1392 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1393 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1394 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1395 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1398 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1403 for (i
= 0; i
< nr_slots
; i
++)
1404 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1408 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1410 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1413 unsigned int hashsize
, old_size
;
1414 struct hlist_nulls_head
*hash
, *old_hash
;
1415 struct nf_conntrack_tuple_hash
*h
;
1418 if (current
->nsproxy
->net_ns
!= &init_net
)
1421 /* On boot, we can set this without any fancy locking. */
1422 if (!nf_conntrack_htable_size
)
1423 return param_set_uint(val
, kp
);
1425 rc
= kstrtouint(val
, 0, &hashsize
);
1431 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1435 /* Lookups in the old hash might happen in parallel, which means we
1436 * might get false negatives during connection lookup. New connections
1437 * created because of a false negative won't make it into the hash
1438 * though since that required taking the lock.
1440 spin_lock_bh(&nf_conntrack_lock
);
1441 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1442 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1443 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1444 struct nf_conntrack_tuple_hash
, hnnode
);
1445 ct
= nf_ct_tuplehash_to_ctrack(h
);
1446 hlist_nulls_del_rcu(&h
->hnnode
);
1447 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1449 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1452 old_size
= init_net
.ct
.htable_size
;
1453 old_hash
= init_net
.ct
.hash
;
1455 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1456 init_net
.ct
.hash
= hash
;
1457 spin_unlock_bh(&nf_conntrack_lock
);
1459 nf_ct_free_hashtable(old_hash
, old_size
);
1462 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1464 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1465 &nf_conntrack_htable_size
, 0600);
1467 void nf_ct_untracked_status_or(unsigned long bits
)
1471 for_each_possible_cpu(cpu
)
1472 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1474 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1476 static int nf_conntrack_init_init_net(void)
1481 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1482 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1483 if (!nf_conntrack_htable_size
) {
1484 nf_conntrack_htable_size
1485 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1486 / sizeof(struct hlist_head
));
1487 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1488 nf_conntrack_htable_size
= 16384;
1489 if (nf_conntrack_htable_size
< 32)
1490 nf_conntrack_htable_size
= 32;
1492 /* Use a max. factor of four by default to get the same max as
1493 * with the old struct list_heads. When a table size is given
1494 * we use the old value of 8 to avoid reducing the max.
1498 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1500 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1501 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1503 #ifdef CONFIG_NF_CONNTRACK_ZONES
1504 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1508 /* Set up fake conntrack: to never be deleted, not in any hashes */
1509 for_each_possible_cpu(cpu
) {
1510 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1511 write_pnet(&ct
->ct_net
, &init_net
);
1512 atomic_set(&ct
->ct_general
.use
, 1);
1514 /* - and look it like as a confirmed connection */
1515 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1518 #ifdef CONFIG_NF_CONNTRACK_ZONES
1525 * We need to use special "null" values, not used in hash table
1527 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1528 #define DYING_NULLS_VAL ((1<<30)+1)
1530 static int nf_conntrack_init_net(struct net
*net
)
1534 atomic_set(&net
->ct
.count
, 0);
1535 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1536 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1537 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1538 if (!net
->ct
.stat
) {
1543 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1544 if (!net
->ct
.slabname
) {
1549 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1550 sizeof(struct nf_conn
), 0,
1551 SLAB_DESTROY_BY_RCU
, NULL
);
1552 if (!net
->ct
.nf_conntrack_cachep
) {
1553 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1558 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1559 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1560 if (!net
->ct
.hash
) {
1562 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1565 ret
= nf_conntrack_expect_init(net
);
1568 ret
= nf_conntrack_acct_init(net
);
1571 ret
= nf_conntrack_tstamp_init(net
);
1574 ret
= nf_conntrack_ecache_init(net
);
1577 ret
= nf_conntrack_timeout_init(net
);
1580 ret
= nf_conntrack_helper_init(net
);
1585 nf_conntrack_timeout_fini(net
);
1587 nf_conntrack_ecache_fini(net
);
1589 nf_conntrack_tstamp_fini(net
);
1591 nf_conntrack_acct_fini(net
);
1593 nf_conntrack_expect_fini(net
);
1595 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1597 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1599 kfree(net
->ct
.slabname
);
1601 free_percpu(net
->ct
.stat
);
1606 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1607 enum ip_conntrack_dir dir
,
1609 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1611 int nf_conntrack_init(struct net
*net
)
1615 if (net_eq(net
, &init_net
)) {
1616 ret
= nf_conntrack_init_init_net();
1620 ret
= nf_conntrack_proto_init(net
);
1623 ret
= nf_conntrack_init_net(net
);
1627 if (net_eq(net
, &init_net
)) {
1628 /* For use by REJECT target */
1629 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1630 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1632 /* Howto get NAT offsets */
1633 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1638 nf_conntrack_proto_fini(net
);
1640 if (net_eq(net
, &init_net
))
1641 nf_conntrack_cleanup_init_net();