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>
8 * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/types.h>
16 #include <linux/netfilter.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/skbuff.h>
20 #include <linux/proc_fs.h>
21 #include <linux/vmalloc.h>
22 #include <linux/stddef.h>
23 #include <linux/slab.h>
24 #include <linux/random.h>
25 #include <linux/jhash.h>
26 #include <linux/err.h>
27 #include <linux/percpu.h>
28 #include <linux/moduleparam.h>
29 #include <linux/notifier.h>
30 #include <linux/kernel.h>
31 #include <linux/netdevice.h>
32 #include <linux/socket.h>
34 #include <linux/nsproxy.h>
35 #include <linux/rculist_nulls.h>
37 #include <net/netfilter/nf_conntrack.h>
38 #include <net/netfilter/nf_conntrack_l3proto.h>
39 #include <net/netfilter/nf_conntrack_l4proto.h>
40 #include <net/netfilter/nf_conntrack_expect.h>
41 #include <net/netfilter/nf_conntrack_helper.h>
42 #include <net/netfilter/nf_conntrack_seqadj.h>
43 #include <net/netfilter/nf_conntrack_core.h>
44 #include <net/netfilter/nf_conntrack_extend.h>
45 #include <net/netfilter/nf_conntrack_acct.h>
46 #include <net/netfilter/nf_conntrack_ecache.h>
47 #include <net/netfilter/nf_conntrack_zones.h>
48 #include <net/netfilter/nf_conntrack_timestamp.h>
49 #include <net/netfilter/nf_conntrack_timeout.h>
50 #include <net/netfilter/nf_conntrack_labels.h>
51 #include <net/netfilter/nf_conntrack_synproxy.h>
52 #include <net/netfilter/nf_nat.h>
53 #include <net/netfilter/nf_nat_core.h>
54 #include <net/netfilter/nf_nat_helper.h>
56 #define NF_CONNTRACK_VERSION "0.5.0"
58 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
59 enum nf_nat_manip_type manip
,
60 const struct nlattr
*attr
) __read_mostly
;
61 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
63 DEFINE_SPINLOCK(nf_conntrack_lock
);
64 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
66 unsigned int nf_conntrack_htable_size __read_mostly
;
67 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
69 unsigned int nf_conntrack_max __read_mostly
;
70 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
72 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
73 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
75 unsigned int nf_conntrack_hash_rnd __read_mostly
;
76 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
78 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
82 /* The direction must be ignored, so we hash everything up to the
83 * destination ports (which is a multiple of 4) and treat the last
84 * three bytes manually.
86 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
87 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
88 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
89 tuple
->dst
.protonum
));
92 static u32
__hash_bucket(u32 hash
, unsigned int size
)
94 return ((u64
)hash
* size
) >> 32;
97 static u32
hash_bucket(u32 hash
, const struct net
*net
)
99 return __hash_bucket(hash
, net
->ct
.htable_size
);
102 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
103 u16 zone
, unsigned int size
)
105 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
108 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
109 const struct nf_conntrack_tuple
*tuple
)
111 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
115 nf_ct_get_tuple(const struct sk_buff
*skb
,
117 unsigned int dataoff
,
120 struct nf_conntrack_tuple
*tuple
,
121 const struct nf_conntrack_l3proto
*l3proto
,
122 const struct nf_conntrack_l4proto
*l4proto
)
124 memset(tuple
, 0, sizeof(*tuple
));
126 tuple
->src
.l3num
= l3num
;
127 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
130 tuple
->dst
.protonum
= protonum
;
131 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
133 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
135 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
137 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
138 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
140 struct nf_conntrack_l3proto
*l3proto
;
141 struct nf_conntrack_l4proto
*l4proto
;
142 unsigned int protoff
;
148 l3proto
= __nf_ct_l3proto_find(l3num
);
149 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
150 if (ret
!= NF_ACCEPT
) {
155 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
157 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
163 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
166 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
167 const struct nf_conntrack_tuple
*orig
,
168 const struct nf_conntrack_l3proto
*l3proto
,
169 const struct nf_conntrack_l4proto
*l4proto
)
171 memset(inverse
, 0, sizeof(*inverse
));
173 inverse
->src
.l3num
= orig
->src
.l3num
;
174 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
177 inverse
->dst
.dir
= !orig
->dst
.dir
;
179 inverse
->dst
.protonum
= orig
->dst
.protonum
;
180 return l4proto
->invert_tuple(inverse
, orig
);
182 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
185 clean_from_lists(struct nf_conn
*ct
)
187 pr_debug("clean_from_lists(%p)\n", ct
);
188 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
189 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
191 /* Destroy all pending expectations */
192 nf_ct_remove_expectations(ct
);
196 destroy_conntrack(struct nf_conntrack
*nfct
)
198 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
199 struct net
*net
= nf_ct_net(ct
);
200 struct nf_conntrack_l4proto
*l4proto
;
202 pr_debug("destroy_conntrack(%p)\n", ct
);
203 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
204 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
206 /* To make sure we don't get any weird locking issues here:
207 * destroy_conntrack() MUST NOT be called with a write lock
208 * to nf_conntrack_lock!!! -HW */
210 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
211 if (l4proto
&& l4proto
->destroy
)
212 l4proto
->destroy(ct
);
216 spin_lock_bh(&nf_conntrack_lock
);
217 /* Expectations will have been removed in clean_from_lists,
218 * except TFTP can create an expectation on the first packet,
219 * before connection is in the list, so we need to clean here,
221 nf_ct_remove_expectations(ct
);
223 /* We overload first tuple to link into unconfirmed or dying list.*/
224 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
225 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
227 NF_CT_STAT_INC(net
, delete);
228 spin_unlock_bh(&nf_conntrack_lock
);
231 nf_ct_put(ct
->master
);
233 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
234 nf_conntrack_free(ct
);
237 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
239 struct net
*net
= nf_ct_net(ct
);
241 nf_ct_helper_destroy(ct
);
242 spin_lock_bh(&nf_conntrack_lock
);
243 /* Inside lock so preempt is disabled on module removal path.
244 * Otherwise we can get spurious warnings. */
245 NF_CT_STAT_INC(net
, delete_list
);
246 clean_from_lists(ct
);
247 /* add this conntrack to the dying list */
248 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
250 spin_unlock_bh(&nf_conntrack_lock
);
253 static void death_by_event(unsigned long ul_conntrack
)
255 struct nf_conn
*ct
= (void *)ul_conntrack
;
256 struct net
*net
= nf_ct_net(ct
);
257 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
259 BUG_ON(ecache
== NULL
);
261 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
262 /* bad luck, let's retry again */
263 ecache
->timeout
.expires
= jiffies
+
264 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
265 add_timer(&ecache
->timeout
);
268 /* we've got the event delivered, now it's dying */
269 set_bit(IPS_DYING_BIT
, &ct
->status
);
273 static void nf_ct_dying_timeout(struct nf_conn
*ct
)
275 struct net
*net
= nf_ct_net(ct
);
276 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
278 BUG_ON(ecache
== NULL
);
280 /* set a new timer to retry event delivery */
281 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
282 ecache
->timeout
.expires
= jiffies
+
283 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
284 add_timer(&ecache
->timeout
);
287 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
289 struct nf_conn_tstamp
*tstamp
;
291 tstamp
= nf_conn_tstamp_find(ct
);
292 if (tstamp
&& tstamp
->stop
== 0)
293 tstamp
->stop
= ktime_to_ns(ktime_get_real());
295 if (!nf_ct_is_dying(ct
) &&
296 unlikely(nf_conntrack_event_report(IPCT_DESTROY
, ct
,
297 portid
, report
) < 0)) {
298 /* destroy event was not delivered */
299 nf_ct_delete_from_lists(ct
);
300 nf_ct_dying_timeout(ct
);
303 set_bit(IPS_DYING_BIT
, &ct
->status
);
304 nf_ct_delete_from_lists(ct
);
308 EXPORT_SYMBOL_GPL(nf_ct_delete
);
310 static void death_by_timeout(unsigned long ul_conntrack
)
312 nf_ct_delete((struct nf_conn
*)ul_conntrack
, 0, 0);
317 * - Caller must take a reference on returned object
318 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
320 * - Caller must lock nf_conntrack_lock before calling this function
322 static struct nf_conntrack_tuple_hash
*
323 ____nf_conntrack_find(struct net
*net
, u16 zone
,
324 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
326 struct nf_conntrack_tuple_hash
*h
;
327 struct hlist_nulls_node
*n
;
328 unsigned int bucket
= hash_bucket(hash
, net
);
330 /* Disable BHs the entire time since we normally need to disable them
331 * at least once for the stats anyway.
335 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
336 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
337 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
338 NF_CT_STAT_INC(net
, found
);
342 NF_CT_STAT_INC(net
, searched
);
345 * if the nulls value we got at the end of this lookup is
346 * not the expected one, we must restart lookup.
347 * We probably met an item that was moved to another chain.
349 if (get_nulls_value(n
) != bucket
) {
350 NF_CT_STAT_INC(net
, search_restart
);
358 /* Find a connection corresponding to a tuple. */
359 static struct nf_conntrack_tuple_hash
*
360 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
361 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
363 struct nf_conntrack_tuple_hash
*h
;
368 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
370 ct
= nf_ct_tuplehash_to_ctrack(h
);
371 if (unlikely(nf_ct_is_dying(ct
) ||
372 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
375 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
376 nf_ct_zone(ct
) != zone
)) {
387 struct nf_conntrack_tuple_hash
*
388 nf_conntrack_find_get(struct net
*net
, u16 zone
,
389 const struct nf_conntrack_tuple
*tuple
)
391 return __nf_conntrack_find_get(net
, zone
, tuple
,
392 hash_conntrack_raw(tuple
, zone
));
394 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
396 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
398 unsigned int repl_hash
)
400 struct net
*net
= nf_ct_net(ct
);
402 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
403 &net
->ct
.hash
[hash
]);
404 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
405 &net
->ct
.hash
[repl_hash
]);
409 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
411 struct net
*net
= nf_ct_net(ct
);
412 unsigned int hash
, repl_hash
;
413 struct nf_conntrack_tuple_hash
*h
;
414 struct hlist_nulls_node
*n
;
417 zone
= nf_ct_zone(ct
);
418 hash
= hash_conntrack(net
, zone
,
419 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
420 repl_hash
= hash_conntrack(net
, zone
,
421 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
423 spin_lock_bh(&nf_conntrack_lock
);
425 /* See if there's one in the list already, including reverse */
426 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
427 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
429 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
431 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
432 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
434 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
437 add_timer(&ct
->timeout
);
438 nf_conntrack_get(&ct
->ct_general
);
439 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
440 NF_CT_STAT_INC(net
, insert
);
441 spin_unlock_bh(&nf_conntrack_lock
);
446 NF_CT_STAT_INC(net
, insert_failed
);
447 spin_unlock_bh(&nf_conntrack_lock
);
450 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
452 /* Confirm a connection given skb; places it in hash table */
454 __nf_conntrack_confirm(struct sk_buff
*skb
)
456 unsigned int hash
, repl_hash
;
457 struct nf_conntrack_tuple_hash
*h
;
459 struct nf_conn_help
*help
;
460 struct nf_conn_tstamp
*tstamp
;
461 struct hlist_nulls_node
*n
;
462 enum ip_conntrack_info ctinfo
;
466 ct
= nf_ct_get(skb
, &ctinfo
);
469 /* ipt_REJECT uses nf_conntrack_attach to attach related
470 ICMP/TCP RST packets in other direction. Actual packet
471 which created connection will be IP_CT_NEW or for an
472 expected connection, IP_CT_RELATED. */
473 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
476 zone
= nf_ct_zone(ct
);
477 /* reuse the hash saved before */
478 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
479 hash
= hash_bucket(hash
, net
);
480 repl_hash
= hash_conntrack(net
, zone
,
481 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
483 /* We're not in hash table, and we refuse to set up related
484 connections for unconfirmed conns. But packet copies and
485 REJECT will give spurious warnings here. */
486 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
488 /* No external references means no one else could have
490 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
491 pr_debug("Confirming conntrack %p\n", ct
);
493 spin_lock_bh(&nf_conntrack_lock
);
495 /* We have to check the DYING flag inside the lock to prevent
496 a race against nf_ct_get_next_corpse() possibly called from
497 user context, else we insert an already 'dead' hash, blocking
498 further use of that particular connection -JM */
500 if (unlikely(nf_ct_is_dying(ct
))) {
501 spin_unlock_bh(&nf_conntrack_lock
);
505 /* See if there's one in the list already, including reverse:
506 NAT could have grabbed it without realizing, since we're
507 not in the hash. If there is, we lost race. */
508 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
509 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
511 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
513 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
514 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
516 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
519 /* Remove from unconfirmed list */
520 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
522 /* Timer relative to confirmation time, not original
523 setting time, otherwise we'd get timer wrap in
524 weird delay cases. */
525 ct
->timeout
.expires
+= jiffies
;
526 add_timer(&ct
->timeout
);
527 atomic_inc(&ct
->ct_general
.use
);
528 ct
->status
|= IPS_CONFIRMED
;
530 /* set conntrack timestamp, if enabled. */
531 tstamp
= nf_conn_tstamp_find(ct
);
533 if (skb
->tstamp
.tv64
== 0)
534 __net_timestamp(skb
);
536 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
538 /* Since the lookup is lockless, hash insertion must be done after
539 * starting the timer and setting the CONFIRMED bit. The RCU barriers
540 * guarantee that no other CPU can find the conntrack before the above
541 * stores are visible.
543 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
544 NF_CT_STAT_INC(net
, insert
);
545 spin_unlock_bh(&nf_conntrack_lock
);
547 help
= nfct_help(ct
);
548 if (help
&& help
->helper
)
549 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
551 nf_conntrack_event_cache(master_ct(ct
) ?
552 IPCT_RELATED
: IPCT_NEW
, ct
);
556 NF_CT_STAT_INC(net
, insert_failed
);
557 spin_unlock_bh(&nf_conntrack_lock
);
560 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
562 /* Returns true if a connection correspondings to the tuple (required
565 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
566 const struct nf_conn
*ignored_conntrack
)
568 struct net
*net
= nf_ct_net(ignored_conntrack
);
569 struct nf_conntrack_tuple_hash
*h
;
570 struct hlist_nulls_node
*n
;
572 u16 zone
= nf_ct_zone(ignored_conntrack
);
573 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
575 /* Disable BHs the entire time since we need to disable them at
576 * least once for the stats anyway.
579 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
580 ct
= nf_ct_tuplehash_to_ctrack(h
);
581 if (ct
!= ignored_conntrack
&&
582 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
583 nf_ct_zone(ct
) == zone
) {
584 NF_CT_STAT_INC(net
, found
);
585 rcu_read_unlock_bh();
588 NF_CT_STAT_INC(net
, searched
);
590 rcu_read_unlock_bh();
594 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
596 #define NF_CT_EVICTION_RANGE 8
598 /* There's a small race here where we may free a just-assured
599 connection. Too bad: we're in trouble anyway. */
600 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
602 /* Use oldest entry, which is roughly LRU */
603 struct nf_conntrack_tuple_hash
*h
;
604 struct nf_conn
*ct
= NULL
, *tmp
;
605 struct hlist_nulls_node
*n
;
606 unsigned int i
, cnt
= 0;
610 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
611 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
613 tmp
= nf_ct_tuplehash_to_ctrack(h
);
614 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
620 if (likely(!nf_ct_is_dying(ct
) &&
621 atomic_inc_not_zero(&ct
->ct_general
.use
)))
627 if (cnt
>= NF_CT_EVICTION_RANGE
)
630 hash
= (hash
+ 1) % net
->ct
.htable_size
;
637 if (del_timer(&ct
->timeout
)) {
638 if (nf_ct_delete(ct
, 0, 0)) {
640 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
647 void init_nf_conntrack_hash_rnd(void)
652 * Why not initialize nf_conntrack_rnd in a "init()" function ?
653 * Because there isn't enough entropy when system initializing,
654 * and we initialize it as late as possible.
657 get_random_bytes(&rand
, sizeof(rand
));
659 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
662 static struct nf_conn
*
663 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
664 const struct nf_conntrack_tuple
*orig
,
665 const struct nf_conntrack_tuple
*repl
,
670 if (unlikely(!nf_conntrack_hash_rnd
)) {
671 init_nf_conntrack_hash_rnd();
672 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
673 hash
= hash_conntrack_raw(orig
, zone
);
676 /* We don't want any race condition at early drop stage */
677 atomic_inc(&net
->ct
.count
);
679 if (nf_conntrack_max
&&
680 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
681 if (!early_drop(net
, hash_bucket(hash
, net
))) {
682 atomic_dec(&net
->ct
.count
);
683 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
684 return ERR_PTR(-ENOMEM
);
689 * Do not use kmem_cache_zalloc(), as this cache uses
690 * SLAB_DESTROY_BY_RCU.
692 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
694 atomic_dec(&net
->ct
.count
);
695 return ERR_PTR(-ENOMEM
);
698 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
699 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
701 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
702 offsetof(struct nf_conn
, proto
) -
703 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
704 spin_lock_init(&ct
->lock
);
705 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
706 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
707 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
708 /* save hash for reusing when confirming */
709 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
710 /* Don't set timer yet: wait for confirmation */
711 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
712 write_pnet(&ct
->ct_net
, net
);
713 #ifdef CONFIG_NF_CONNTRACK_ZONES
715 struct nf_conntrack_zone
*nf_ct_zone
;
717 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
720 nf_ct_zone
->id
= zone
;
724 * changes to lookup keys must be done before setting refcnt to 1
727 atomic_set(&ct
->ct_general
.use
, 1);
730 #ifdef CONFIG_NF_CONNTRACK_ZONES
732 atomic_dec(&net
->ct
.count
);
733 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
734 return ERR_PTR(-ENOMEM
);
738 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
739 const struct nf_conntrack_tuple
*orig
,
740 const struct nf_conntrack_tuple
*repl
,
743 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
745 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
747 void nf_conntrack_free(struct nf_conn
*ct
)
749 struct net
*net
= nf_ct_net(ct
);
751 nf_ct_ext_destroy(ct
);
753 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
754 smp_mb__before_atomic_dec();
755 atomic_dec(&net
->ct
.count
);
757 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
760 /* Allocate a new conntrack: we return -ENOMEM if classification
761 failed due to stress. Otherwise it really is unclassifiable. */
762 static struct nf_conntrack_tuple_hash
*
763 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
764 const struct nf_conntrack_tuple
*tuple
,
765 struct nf_conntrack_l3proto
*l3proto
,
766 struct nf_conntrack_l4proto
*l4proto
,
768 unsigned int dataoff
, u32 hash
)
771 struct nf_conn_help
*help
;
772 struct nf_conntrack_tuple repl_tuple
;
773 struct nf_conntrack_ecache
*ecache
;
774 struct nf_conntrack_expect
*exp
;
775 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
776 struct nf_conn_timeout
*timeout_ext
;
777 unsigned int *timeouts
;
779 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
780 pr_debug("Can't invert tuple.\n");
784 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
787 return (struct nf_conntrack_tuple_hash
*)ct
;
789 if (tmpl
&& nfct_synproxy(tmpl
)) {
790 nfct_seqadj_ext_add(ct
);
791 nfct_synproxy_ext_add(ct
);
794 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
796 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
798 timeouts
= l4proto
->get_timeouts(net
);
800 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
801 nf_conntrack_free(ct
);
802 pr_debug("init conntrack: can't track with proto module\n");
807 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
809 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
810 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
811 nf_ct_labels_ext_add(ct
);
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_acct
*acct
;
1100 acct
= nf_conn_acct_find(ct
);
1102 struct nf_conn_counter
*counter
= acct
->counter
;
1104 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
1105 atomic64_add(skb
->len
, &counter
[CTINFO2DIR(ctinfo
)].bytes
);
1109 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1111 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1112 enum ip_conntrack_info ctinfo
,
1113 const struct sk_buff
*skb
,
1117 struct nf_conn_acct
*acct
;
1119 acct
= nf_conn_acct_find(ct
);
1121 struct nf_conn_counter
*counter
= acct
->counter
;
1123 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
1124 atomic64_add(skb
->len
- skb_network_offset(skb
),
1125 &counter
[CTINFO2DIR(ctinfo
)].bytes
);
1129 if (del_timer(&ct
->timeout
)) {
1130 ct
->timeout
.function((unsigned long)ct
);
1135 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1137 #ifdef CONFIG_NF_CONNTRACK_ZONES
1138 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1139 .len
= sizeof(struct nf_conntrack_zone
),
1140 .align
= __alignof__(struct nf_conntrack_zone
),
1141 .id
= NF_CT_EXT_ZONE
,
1145 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1147 #include <linux/netfilter/nfnetlink.h>
1148 #include <linux/netfilter/nfnetlink_conntrack.h>
1149 #include <linux/mutex.h>
1151 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1152 * in ip_conntrack_core, since we don't want the protocols to autoload
1153 * or depend on ctnetlink */
1154 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1155 const struct nf_conntrack_tuple
*tuple
)
1157 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1158 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1159 goto nla_put_failure
;
1165 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1167 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1168 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1169 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1171 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1173 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1174 struct nf_conntrack_tuple
*t
)
1176 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1179 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1180 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1184 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1186 int nf_ct_port_nlattr_tuple_size(void)
1188 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1190 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1193 /* Used by ipt_REJECT and ip6t_REJECT. */
1194 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1197 enum ip_conntrack_info ctinfo
;
1199 /* This ICMP is in reverse direction to the packet which caused it */
1200 ct
= nf_ct_get(skb
, &ctinfo
);
1201 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1202 ctinfo
= IP_CT_RELATED_REPLY
;
1204 ctinfo
= IP_CT_RELATED
;
1206 /* Attach to new skbuff, and increment count */
1207 nskb
->nfct
= &ct
->ct_general
;
1208 nskb
->nfctinfo
= ctinfo
;
1209 nf_conntrack_get(nskb
->nfct
);
1212 /* Bring out ya dead! */
1213 static struct nf_conn
*
1214 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1215 void *data
, unsigned int *bucket
)
1217 struct nf_conntrack_tuple_hash
*h
;
1219 struct hlist_nulls_node
*n
;
1221 spin_lock_bh(&nf_conntrack_lock
);
1222 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1223 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1224 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1226 ct
= nf_ct_tuplehash_to_ctrack(h
);
1231 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1232 ct
= nf_ct_tuplehash_to_ctrack(h
);
1234 set_bit(IPS_DYING_BIT
, &ct
->status
);
1236 spin_unlock_bh(&nf_conntrack_lock
);
1239 atomic_inc(&ct
->ct_general
.use
);
1240 spin_unlock_bh(&nf_conntrack_lock
);
1244 void nf_ct_iterate_cleanup(struct net
*net
,
1245 int (*iter
)(struct nf_conn
*i
, void *data
),
1246 void *data
, u32 portid
, int report
)
1249 unsigned int bucket
= 0;
1251 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1252 /* Time to push up daises... */
1253 if (del_timer(&ct
->timeout
))
1254 nf_ct_delete(ct
, portid
, report
);
1256 /* ... else the timer will get him soon. */
1261 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1263 static int kill_all(struct nf_conn
*i
, void *data
)
1268 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1270 if (is_vmalloc_addr(hash
))
1273 free_pages((unsigned long)hash
,
1274 get_order(sizeof(struct hlist_head
) * size
));
1276 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1278 void nf_conntrack_flush_report(struct net
*net
, u32 portid
, int report
)
1280 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, portid
, report
);
1282 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1284 static void nf_ct_release_dying_list(struct net
*net
)
1286 struct nf_conntrack_tuple_hash
*h
;
1288 struct hlist_nulls_node
*n
;
1290 spin_lock_bh(&nf_conntrack_lock
);
1291 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1292 ct
= nf_ct_tuplehash_to_ctrack(h
);
1293 /* never fails to remove them, no listeners at this point */
1296 spin_unlock_bh(&nf_conntrack_lock
);
1299 static int untrack_refs(void)
1303 for_each_possible_cpu(cpu
) {
1304 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1306 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1311 void nf_conntrack_cleanup_start(void)
1313 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1316 void nf_conntrack_cleanup_end(void)
1318 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1319 while (untrack_refs() > 0)
1322 #ifdef CONFIG_NF_CONNTRACK_ZONES
1323 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1325 nf_conntrack_proto_fini();
1326 nf_conntrack_seqadj_fini();
1327 nf_conntrack_labels_fini();
1328 nf_conntrack_helper_fini();
1329 nf_conntrack_timeout_fini();
1330 nf_conntrack_ecache_fini();
1331 nf_conntrack_tstamp_fini();
1332 nf_conntrack_acct_fini();
1333 nf_conntrack_expect_fini();
1337 * Mishearing the voices in his head, our hero wonders how he's
1338 * supposed to kill the mall.
1340 void nf_conntrack_cleanup_net(struct net
*net
)
1344 list_add(&net
->exit_list
, &single
);
1345 nf_conntrack_cleanup_net_list(&single
);
1348 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1354 * This makes sure all current packets have passed through
1355 * netfilter framework. Roll on, two-stage module
1361 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1362 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1363 nf_ct_release_dying_list(net
);
1364 if (atomic_read(&net
->ct
.count
) != 0)
1369 goto i_see_dead_people
;
1372 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1373 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1374 nf_conntrack_proto_pernet_fini(net
);
1375 nf_conntrack_helper_pernet_fini(net
);
1376 nf_conntrack_ecache_pernet_fini(net
);
1377 nf_conntrack_tstamp_pernet_fini(net
);
1378 nf_conntrack_acct_pernet_fini(net
);
1379 nf_conntrack_expect_pernet_fini(net
);
1380 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1381 kfree(net
->ct
.slabname
);
1382 free_percpu(net
->ct
.stat
);
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 int nf_conntrack_init_start(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
,
1504 ret
= nf_conntrack_expect_init();
1508 ret
= nf_conntrack_acct_init();
1512 ret
= nf_conntrack_tstamp_init();
1516 ret
= nf_conntrack_ecache_init();
1520 ret
= nf_conntrack_timeout_init();
1524 ret
= nf_conntrack_helper_init();
1528 ret
= nf_conntrack_labels_init();
1532 ret
= nf_conntrack_seqadj_init();
1536 #ifdef CONFIG_NF_CONNTRACK_ZONES
1537 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1541 ret
= nf_conntrack_proto_init();
1545 /* Set up fake conntrack: to never be deleted, not in any hashes */
1546 for_each_possible_cpu(cpu
) {
1547 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1548 write_pnet(&ct
->ct_net
, &init_net
);
1549 atomic_set(&ct
->ct_general
.use
, 1);
1551 /* - and look it like as a confirmed connection */
1552 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1556 #ifdef CONFIG_NF_CONNTRACK_ZONES
1557 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1560 nf_conntrack_seqadj_fini();
1562 nf_conntrack_labels_fini();
1564 nf_conntrack_helper_fini();
1566 nf_conntrack_timeout_fini();
1568 nf_conntrack_ecache_fini();
1570 nf_conntrack_tstamp_fini();
1572 nf_conntrack_acct_fini();
1574 nf_conntrack_expect_fini();
1579 void nf_conntrack_init_end(void)
1581 /* For use by REJECT target */
1582 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1583 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1587 * We need to use special "null" values, not used in hash table
1589 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1590 #define DYING_NULLS_VAL ((1<<30)+1)
1591 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1593 int nf_conntrack_init_net(struct net
*net
)
1597 atomic_set(&net
->ct
.count
, 0);
1598 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1599 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1600 INIT_HLIST_NULLS_HEAD(&net
->ct
.tmpl
, TEMPLATE_NULLS_VAL
);
1601 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1602 if (!net
->ct
.stat
) {
1607 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1608 if (!net
->ct
.slabname
) {
1613 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1614 sizeof(struct nf_conn
), 0,
1615 SLAB_DESTROY_BY_RCU
, NULL
);
1616 if (!net
->ct
.nf_conntrack_cachep
) {
1617 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1622 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1623 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1624 if (!net
->ct
.hash
) {
1626 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1629 ret
= nf_conntrack_expect_pernet_init(net
);
1632 ret
= nf_conntrack_acct_pernet_init(net
);
1635 ret
= nf_conntrack_tstamp_pernet_init(net
);
1638 ret
= nf_conntrack_ecache_pernet_init(net
);
1641 ret
= nf_conntrack_helper_pernet_init(net
);
1644 ret
= nf_conntrack_proto_pernet_init(net
);
1650 nf_conntrack_helper_pernet_fini(net
);
1652 nf_conntrack_ecache_pernet_fini(net
);
1654 nf_conntrack_tstamp_pernet_fini(net
);
1656 nf_conntrack_acct_pernet_fini(net
);
1658 nf_conntrack_expect_pernet_fini(net
);
1660 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1662 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1664 kfree(net
->ct
.slabname
);
1666 free_percpu(net
->ct
.stat
);