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_core.h>
43 #include <net/netfilter/nf_conntrack_extend.h>
44 #include <net/netfilter/nf_conntrack_acct.h>
45 #include <net/netfilter/nf_conntrack_ecache.h>
46 #include <net/netfilter/nf_conntrack_zones.h>
47 #include <net/netfilter/nf_conntrack_timestamp.h>
48 #include <net/netfilter/nf_conntrack_timeout.h>
49 #include <net/netfilter/nf_conntrack_labels.h>
50 #include <net/netfilter/nf_nat.h>
51 #include <net/netfilter/nf_nat_core.h>
52 #include <net/netfilter/nf_nat_helper.h>
54 #define NF_CONNTRACK_VERSION "0.5.0"
56 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
57 enum nf_nat_manip_type manip
,
58 const struct nlattr
*attr
) __read_mostly
;
59 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
61 int (*nf_nat_seq_adjust_hook
)(struct sk_buff
*skb
,
63 enum ip_conntrack_info ctinfo
,
64 unsigned int protoff
);
65 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook
);
67 DEFINE_SPINLOCK(nf_conntrack_lock
);
68 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
70 unsigned int nf_conntrack_htable_size __read_mostly
;
71 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
73 unsigned int nf_conntrack_max __read_mostly
;
74 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
76 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
77 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
79 unsigned int nf_conntrack_hash_rnd __read_mostly
;
80 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
82 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
86 /* The direction must be ignored, so we hash everything up to the
87 * destination ports (which is a multiple of 4) and treat the last
88 * three bytes manually.
90 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
91 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
92 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
93 tuple
->dst
.protonum
));
96 static u32
__hash_bucket(u32 hash
, unsigned int size
)
98 return ((u64
)hash
* size
) >> 32;
101 static u32
hash_bucket(u32 hash
, const struct net
*net
)
103 return __hash_bucket(hash
, net
->ct
.htable_size
);
106 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
107 u16 zone
, unsigned int size
)
109 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
112 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
113 const struct nf_conntrack_tuple
*tuple
)
115 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
119 nf_ct_get_tuple(const struct sk_buff
*skb
,
121 unsigned int dataoff
,
124 struct nf_conntrack_tuple
*tuple
,
125 const struct nf_conntrack_l3proto
*l3proto
,
126 const struct nf_conntrack_l4proto
*l4proto
)
128 memset(tuple
, 0, sizeof(*tuple
));
130 tuple
->src
.l3num
= l3num
;
131 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
134 tuple
->dst
.protonum
= protonum
;
135 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
137 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
139 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
141 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
142 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
144 struct nf_conntrack_l3proto
*l3proto
;
145 struct nf_conntrack_l4proto
*l4proto
;
146 unsigned int protoff
;
152 l3proto
= __nf_ct_l3proto_find(l3num
);
153 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
154 if (ret
!= NF_ACCEPT
) {
159 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
161 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
167 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
170 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
171 const struct nf_conntrack_tuple
*orig
,
172 const struct nf_conntrack_l3proto
*l3proto
,
173 const struct nf_conntrack_l4proto
*l4proto
)
175 memset(inverse
, 0, sizeof(*inverse
));
177 inverse
->src
.l3num
= orig
->src
.l3num
;
178 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
181 inverse
->dst
.dir
= !orig
->dst
.dir
;
183 inverse
->dst
.protonum
= orig
->dst
.protonum
;
184 return l4proto
->invert_tuple(inverse
, orig
);
186 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
189 clean_from_lists(struct nf_conn
*ct
)
191 pr_debug("clean_from_lists(%p)\n", ct
);
192 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
193 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
195 /* Destroy all pending expectations */
196 nf_ct_remove_expectations(ct
);
200 destroy_conntrack(struct nf_conntrack
*nfct
)
202 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
203 struct net
*net
= nf_ct_net(ct
);
204 struct nf_conntrack_l4proto
*l4proto
;
206 pr_debug("destroy_conntrack(%p)\n", ct
);
207 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
208 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
210 /* To make sure we don't get any weird locking issues here:
211 * destroy_conntrack() MUST NOT be called with a write lock
212 * to nf_conntrack_lock!!! -HW */
214 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
215 if (l4proto
&& l4proto
->destroy
)
216 l4proto
->destroy(ct
);
220 spin_lock_bh(&nf_conntrack_lock
);
221 /* Expectations will have been removed in clean_from_lists,
222 * except TFTP can create an expectation on the first packet,
223 * before connection is in the list, so we need to clean here,
225 nf_ct_remove_expectations(ct
);
227 /* We overload first tuple to link into unconfirmed or dying list.*/
228 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
229 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
231 NF_CT_STAT_INC(net
, delete);
232 spin_unlock_bh(&nf_conntrack_lock
);
235 nf_ct_put(ct
->master
);
237 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
238 nf_conntrack_free(ct
);
241 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
243 struct net
*net
= nf_ct_net(ct
);
245 nf_ct_helper_destroy(ct
);
246 spin_lock_bh(&nf_conntrack_lock
);
247 /* Inside lock so preempt is disabled on module removal path.
248 * Otherwise we can get spurious warnings. */
249 NF_CT_STAT_INC(net
, delete_list
);
250 clean_from_lists(ct
);
251 /* add this conntrack to the dying list */
252 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
254 spin_unlock_bh(&nf_conntrack_lock
);
256 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
258 static void death_by_event(unsigned long ul_conntrack
)
260 struct nf_conn
*ct
= (void *)ul_conntrack
;
261 struct net
*net
= nf_ct_net(ct
);
262 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
264 BUG_ON(ecache
== NULL
);
266 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
267 /* bad luck, let's retry again */
268 ecache
->timeout
.expires
= jiffies
+
269 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
270 add_timer(&ecache
->timeout
);
273 /* we've got the event delivered, now it's dying */
274 set_bit(IPS_DYING_BIT
, &ct
->status
);
278 void nf_ct_dying_timeout(struct nf_conn
*ct
)
280 struct net
*net
= nf_ct_net(ct
);
281 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
283 BUG_ON(ecache
== NULL
);
285 /* set a new timer to retry event delivery */
286 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
287 ecache
->timeout
.expires
= jiffies
+
288 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
289 add_timer(&ecache
->timeout
);
291 EXPORT_SYMBOL_GPL(nf_ct_dying_timeout
);
293 static void death_by_timeout(unsigned long ul_conntrack
)
295 struct nf_conn
*ct
= (void *)ul_conntrack
;
296 struct nf_conn_tstamp
*tstamp
;
298 tstamp
= nf_conn_tstamp_find(ct
);
299 if (tstamp
&& tstamp
->stop
== 0)
300 tstamp
->stop
= ktime_to_ns(ktime_get_real());
302 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
303 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
304 /* destroy event was not delivered */
305 nf_ct_delete_from_lists(ct
);
306 nf_ct_dying_timeout(ct
);
309 set_bit(IPS_DYING_BIT
, &ct
->status
);
310 nf_ct_delete_from_lists(ct
);
316 * - Caller must take a reference on returned object
317 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
319 * - Caller must lock nf_conntrack_lock before calling this function
321 static struct nf_conntrack_tuple_hash
*
322 ____nf_conntrack_find(struct net
*net
, u16 zone
,
323 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
325 struct nf_conntrack_tuple_hash
*h
;
326 struct hlist_nulls_node
*n
;
327 unsigned int bucket
= hash_bucket(hash
, net
);
329 /* Disable BHs the entire time since we normally need to disable them
330 * at least once for the stats anyway.
334 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
335 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
336 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
337 NF_CT_STAT_INC(net
, found
);
341 NF_CT_STAT_INC(net
, searched
);
344 * if the nulls value we got at the end of this lookup is
345 * not the expected one, we must restart lookup.
346 * We probably met an item that was moved to another chain.
348 if (get_nulls_value(n
) != bucket
) {
349 NF_CT_STAT_INC(net
, search_restart
);
357 struct nf_conntrack_tuple_hash
*
358 __nf_conntrack_find(struct net
*net
, u16 zone
,
359 const struct nf_conntrack_tuple
*tuple
)
361 return ____nf_conntrack_find(net
, zone
, tuple
,
362 hash_conntrack_raw(tuple
, zone
));
364 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
366 /* Find a connection corresponding to a tuple. */
367 static struct nf_conntrack_tuple_hash
*
368 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
369 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
371 struct nf_conntrack_tuple_hash
*h
;
376 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
378 ct
= nf_ct_tuplehash_to_ctrack(h
);
379 if (unlikely(nf_ct_is_dying(ct
) ||
380 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
383 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
384 nf_ct_zone(ct
) != zone
)) {
395 struct nf_conntrack_tuple_hash
*
396 nf_conntrack_find_get(struct net
*net
, u16 zone
,
397 const struct nf_conntrack_tuple
*tuple
)
399 return __nf_conntrack_find_get(net
, zone
, tuple
,
400 hash_conntrack_raw(tuple
, zone
));
402 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
404 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
406 unsigned int repl_hash
)
408 struct net
*net
= nf_ct_net(ct
);
410 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
411 &net
->ct
.hash
[hash
]);
412 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
413 &net
->ct
.hash
[repl_hash
]);
417 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
419 struct net
*net
= nf_ct_net(ct
);
420 unsigned int hash
, repl_hash
;
421 struct nf_conntrack_tuple_hash
*h
;
422 struct hlist_nulls_node
*n
;
425 zone
= nf_ct_zone(ct
);
426 hash
= hash_conntrack(net
, zone
,
427 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
428 repl_hash
= hash_conntrack(net
, zone
,
429 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
431 spin_lock_bh(&nf_conntrack_lock
);
433 /* See if there's one in the list already, including reverse */
434 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
435 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
437 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
439 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
440 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
442 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
445 add_timer(&ct
->timeout
);
446 nf_conntrack_get(&ct
->ct_general
);
447 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
448 NF_CT_STAT_INC(net
, insert
);
449 spin_unlock_bh(&nf_conntrack_lock
);
454 NF_CT_STAT_INC(net
, insert_failed
);
455 spin_unlock_bh(&nf_conntrack_lock
);
458 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
460 /* Confirm a connection given skb; places it in hash table */
462 __nf_conntrack_confirm(struct sk_buff
*skb
)
464 unsigned int hash
, repl_hash
;
465 struct nf_conntrack_tuple_hash
*h
;
467 struct nf_conn_help
*help
;
468 struct nf_conn_tstamp
*tstamp
;
469 struct hlist_nulls_node
*n
;
470 enum ip_conntrack_info ctinfo
;
474 ct
= nf_ct_get(skb
, &ctinfo
);
477 /* ipt_REJECT uses nf_conntrack_attach to attach related
478 ICMP/TCP RST packets in other direction. Actual packet
479 which created connection will be IP_CT_NEW or for an
480 expected connection, IP_CT_RELATED. */
481 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
484 zone
= nf_ct_zone(ct
);
485 /* reuse the hash saved before */
486 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
487 hash
= hash_bucket(hash
, net
);
488 repl_hash
= hash_conntrack(net
, zone
,
489 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
491 /* We're not in hash table, and we refuse to set up related
492 connections for unconfirmed conns. But packet copies and
493 REJECT will give spurious warnings here. */
494 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
496 /* No external references means no one else could have
498 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
499 pr_debug("Confirming conntrack %p\n", ct
);
501 spin_lock_bh(&nf_conntrack_lock
);
503 /* We have to check the DYING flag inside the lock to prevent
504 a race against nf_ct_get_next_corpse() possibly called from
505 user context, else we insert an already 'dead' hash, blocking
506 further use of that particular connection -JM */
508 if (unlikely(nf_ct_is_dying(ct
))) {
509 spin_unlock_bh(&nf_conntrack_lock
);
513 /* See if there's one in the list already, including reverse:
514 NAT could have grabbed it without realizing, since we're
515 not in the hash. If there is, we lost race. */
516 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
517 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
519 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
521 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
522 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
524 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
527 /* Remove from unconfirmed list */
528 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
530 /* Timer relative to confirmation time, not original
531 setting time, otherwise we'd get timer wrap in
532 weird delay cases. */
533 ct
->timeout
.expires
+= jiffies
;
534 add_timer(&ct
->timeout
);
535 atomic_inc(&ct
->ct_general
.use
);
536 ct
->status
|= IPS_CONFIRMED
;
538 /* set conntrack timestamp, if enabled. */
539 tstamp
= nf_conn_tstamp_find(ct
);
541 if (skb
->tstamp
.tv64
== 0)
542 __net_timestamp(skb
);
544 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
546 /* Since the lookup is lockless, hash insertion must be done after
547 * starting the timer and setting the CONFIRMED bit. The RCU barriers
548 * guarantee that no other CPU can find the conntrack before the above
549 * stores are visible.
551 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
552 NF_CT_STAT_INC(net
, insert
);
553 spin_unlock_bh(&nf_conntrack_lock
);
555 help
= nfct_help(ct
);
556 if (help
&& help
->helper
)
557 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
559 nf_conntrack_event_cache(master_ct(ct
) ?
560 IPCT_RELATED
: IPCT_NEW
, ct
);
564 NF_CT_STAT_INC(net
, insert_failed
);
565 spin_unlock_bh(&nf_conntrack_lock
);
568 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
570 /* Returns true if a connection correspondings to the tuple (required
573 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
574 const struct nf_conn
*ignored_conntrack
)
576 struct net
*net
= nf_ct_net(ignored_conntrack
);
577 struct nf_conntrack_tuple_hash
*h
;
578 struct hlist_nulls_node
*n
;
580 u16 zone
= nf_ct_zone(ignored_conntrack
);
581 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
583 /* Disable BHs the entire time since we need to disable them at
584 * least once for the stats anyway.
587 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
588 ct
= nf_ct_tuplehash_to_ctrack(h
);
589 if (ct
!= ignored_conntrack
&&
590 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
591 nf_ct_zone(ct
) == zone
) {
592 NF_CT_STAT_INC(net
, found
);
593 rcu_read_unlock_bh();
596 NF_CT_STAT_INC(net
, searched
);
598 rcu_read_unlock_bh();
602 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
604 #define NF_CT_EVICTION_RANGE 8
606 /* There's a small race here where we may free a just-assured
607 connection. Too bad: we're in trouble anyway. */
608 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
610 /* Use oldest entry, which is roughly LRU */
611 struct nf_conntrack_tuple_hash
*h
;
612 struct nf_conn
*ct
= NULL
, *tmp
;
613 struct hlist_nulls_node
*n
;
614 unsigned int i
, cnt
= 0;
618 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
619 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
621 tmp
= nf_ct_tuplehash_to_ctrack(h
);
622 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
628 if (likely(!nf_ct_is_dying(ct
) &&
629 atomic_inc_not_zero(&ct
->ct_general
.use
)))
635 if (cnt
>= NF_CT_EVICTION_RANGE
)
638 hash
= (hash
+ 1) % net
->ct
.htable_size
;
645 if (del_timer(&ct
->timeout
)) {
646 death_by_timeout((unsigned long)ct
);
647 /* Check if we indeed killed this entry. Reliable event
648 delivery may have inserted it into the dying list. */
649 if (test_bit(IPS_DYING_BIT
, &ct
->status
)) {
651 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
658 void init_nf_conntrack_hash_rnd(void)
663 * Why not initialize nf_conntrack_rnd in a "init()" function ?
664 * Because there isn't enough entropy when system initializing,
665 * and we initialize it as late as possible.
668 get_random_bytes(&rand
, sizeof(rand
));
670 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
673 static struct nf_conn
*
674 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
675 const struct nf_conntrack_tuple
*orig
,
676 const struct nf_conntrack_tuple
*repl
,
681 if (unlikely(!nf_conntrack_hash_rnd
)) {
682 init_nf_conntrack_hash_rnd();
683 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
684 hash
= hash_conntrack_raw(orig
, zone
);
687 /* We don't want any race condition at early drop stage */
688 atomic_inc(&net
->ct
.count
);
690 if (nf_conntrack_max
&&
691 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
692 if (!early_drop(net
, hash_bucket(hash
, net
))) {
693 atomic_dec(&net
->ct
.count
);
694 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
695 return ERR_PTR(-ENOMEM
);
700 * Do not use kmem_cache_zalloc(), as this cache uses
701 * SLAB_DESTROY_BY_RCU.
703 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
705 atomic_dec(&net
->ct
.count
);
706 return ERR_PTR(-ENOMEM
);
709 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
710 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
712 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
713 offsetof(struct nf_conn
, proto
) -
714 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
715 spin_lock_init(&ct
->lock
);
716 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
717 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
718 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
719 /* save hash for reusing when confirming */
720 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
721 /* Don't set timer yet: wait for confirmation */
722 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
723 write_pnet(&ct
->ct_net
, net
);
724 #ifdef CONFIG_NF_CONNTRACK_ZONES
726 struct nf_conntrack_zone
*nf_ct_zone
;
728 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
731 nf_ct_zone
->id
= zone
;
735 * changes to lookup keys must be done before setting refcnt to 1
738 atomic_set(&ct
->ct_general
.use
, 1);
741 #ifdef CONFIG_NF_CONNTRACK_ZONES
743 atomic_dec(&net
->ct
.count
);
744 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
745 return ERR_PTR(-ENOMEM
);
749 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
750 const struct nf_conntrack_tuple
*orig
,
751 const struct nf_conntrack_tuple
*repl
,
754 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
756 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
758 void nf_conntrack_free(struct nf_conn
*ct
)
760 struct net
*net
= nf_ct_net(ct
);
762 nf_ct_ext_destroy(ct
);
763 atomic_dec(&net
->ct
.count
);
765 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
767 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
770 /* Allocate a new conntrack: we return -ENOMEM if classification
771 failed due to stress. Otherwise it really is unclassifiable. */
772 static struct nf_conntrack_tuple_hash
*
773 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
774 const struct nf_conntrack_tuple
*tuple
,
775 struct nf_conntrack_l3proto
*l3proto
,
776 struct nf_conntrack_l4proto
*l4proto
,
778 unsigned int dataoff
, u32 hash
)
781 struct nf_conn_help
*help
;
782 struct nf_conntrack_tuple repl_tuple
;
783 struct nf_conntrack_ecache
*ecache
;
784 struct nf_conntrack_expect
*exp
;
785 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
786 struct nf_conn_timeout
*timeout_ext
;
787 unsigned int *timeouts
;
789 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
790 pr_debug("Can't invert tuple.\n");
794 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
797 return (struct nf_conntrack_tuple_hash
*)ct
;
799 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
801 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
803 timeouts
= l4proto
->get_timeouts(net
);
805 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
806 nf_conntrack_free(ct
);
807 pr_debug("init conntrack: can't track with proto module\n");
812 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
814 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
815 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
816 nf_ct_labels_ext_add(ct
);
818 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
819 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
820 ecache
? ecache
->expmask
: 0,
823 spin_lock_bh(&nf_conntrack_lock
);
824 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
826 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
828 /* Welcome, Mr. Bond. We've been expecting you... */
829 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
830 ct
->master
= exp
->master
;
832 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
835 rcu_assign_pointer(help
->helper
, exp
->helper
);
838 #ifdef CONFIG_NF_CONNTRACK_MARK
839 ct
->mark
= exp
->master
->mark
;
841 #ifdef CONFIG_NF_CONNTRACK_SECMARK
842 ct
->secmark
= exp
->master
->secmark
;
844 nf_conntrack_get(&ct
->master
->ct_general
);
845 NF_CT_STAT_INC(net
, expect_new
);
847 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
848 NF_CT_STAT_INC(net
, new);
851 /* Overload tuple linked list to put us in unconfirmed list. */
852 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
853 &net
->ct
.unconfirmed
);
855 spin_unlock_bh(&nf_conntrack_lock
);
859 exp
->expectfn(ct
, exp
);
860 nf_ct_expect_put(exp
);
863 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
866 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
867 static inline struct nf_conn
*
868 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
870 unsigned int dataoff
,
873 struct nf_conntrack_l3proto
*l3proto
,
874 struct nf_conntrack_l4proto
*l4proto
,
876 enum ip_conntrack_info
*ctinfo
)
878 struct nf_conntrack_tuple tuple
;
879 struct nf_conntrack_tuple_hash
*h
;
881 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
884 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
885 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
887 pr_debug("resolve_normal_ct: Can't get tuple\n");
891 /* look for tuple match */
892 hash
= hash_conntrack_raw(&tuple
, zone
);
893 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
895 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
902 ct
= nf_ct_tuplehash_to_ctrack(h
);
904 /* It exists; we have (non-exclusive) reference. */
905 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
906 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
907 /* Please set reply bit if this packet OK */
910 /* Once we've had two way comms, always ESTABLISHED. */
911 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
912 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
913 *ctinfo
= IP_CT_ESTABLISHED
;
914 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
915 pr_debug("nf_conntrack_in: related packet for %p\n",
917 *ctinfo
= IP_CT_RELATED
;
919 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
924 skb
->nfct
= &ct
->ct_general
;
925 skb
->nfctinfo
= *ctinfo
;
930 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
933 struct nf_conn
*ct
, *tmpl
= NULL
;
934 enum ip_conntrack_info ctinfo
;
935 struct nf_conntrack_l3proto
*l3proto
;
936 struct nf_conntrack_l4proto
*l4proto
;
937 unsigned int *timeouts
;
938 unsigned int dataoff
;
944 /* Previously seen (loopback or untracked)? Ignore. */
945 tmpl
= (struct nf_conn
*)skb
->nfct
;
946 if (!nf_ct_is_template(tmpl
)) {
947 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
953 /* rcu_read_lock()ed by nf_hook_slow */
954 l3proto
= __nf_ct_l3proto_find(pf
);
955 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
956 &dataoff
, &protonum
);
958 pr_debug("not prepared to track yet or error occurred\n");
959 NF_CT_STAT_INC_ATOMIC(net
, error
);
960 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
965 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
967 /* It may be an special packet, error, unclean...
968 * inverse of the return code tells to the netfilter
969 * core what to do with the packet. */
970 if (l4proto
->error
!= NULL
) {
971 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
974 NF_CT_STAT_INC_ATOMIC(net
, error
);
975 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
979 /* ICMP[v6] protocol trackers may assign one conntrack. */
984 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
985 l3proto
, l4proto
, &set_reply
, &ctinfo
);
987 /* Not valid part of a connection */
988 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
994 /* Too stressed to deal. */
995 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1000 NF_CT_ASSERT(skb
->nfct
);
1002 /* Decide what timeout policy we want to apply to this flow. */
1003 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1005 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1007 /* Invalid: inverse of the return code tells
1008 * the netfilter core what to do */
1009 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1010 nf_conntrack_put(skb
->nfct
);
1012 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1013 if (ret
== -NF_DROP
)
1014 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1019 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1020 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1023 /* Special case: we have to repeat this hook, assign the
1024 * template again to this packet. We assume that this packet
1025 * has no conntrack assigned. This is used by nf_ct_tcp. */
1026 if (ret
== NF_REPEAT
)
1027 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1034 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1036 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1037 const struct nf_conntrack_tuple
*orig
)
1042 ret
= nf_ct_invert_tuple(inverse
, orig
,
1043 __nf_ct_l3proto_find(orig
->src
.l3num
),
1044 __nf_ct_l4proto_find(orig
->src
.l3num
,
1045 orig
->dst
.protonum
));
1049 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1051 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1052 implicitly racy: see __nf_conntrack_confirm */
1053 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1054 const struct nf_conntrack_tuple
*newreply
)
1056 struct nf_conn_help
*help
= nfct_help(ct
);
1058 /* Should be unconfirmed, so not in hash table yet */
1059 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1061 pr_debug("Altering reply tuple of %p to ", ct
);
1062 nf_ct_dump_tuple(newreply
);
1064 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1065 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1069 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1072 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1074 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1075 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1076 enum ip_conntrack_info ctinfo
,
1077 const struct sk_buff
*skb
,
1078 unsigned long extra_jiffies
,
1081 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1084 /* Only update if this is not a fixed timeout */
1085 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1088 /* If not in hash table, timer will not be active yet */
1089 if (!nf_ct_is_confirmed(ct
)) {
1090 ct
->timeout
.expires
= extra_jiffies
;
1092 unsigned long newtime
= jiffies
+ extra_jiffies
;
1094 /* Only update the timeout if the new timeout is at least
1095 HZ jiffies from the old timeout. Need del_timer for race
1096 avoidance (may already be dying). */
1097 if (newtime
- ct
->timeout
.expires
>= HZ
)
1098 mod_timer_pending(&ct
->timeout
, newtime
);
1103 struct nf_conn_counter
*acct
;
1105 acct
= nf_conn_acct_find(ct
);
1107 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1108 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1112 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1114 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1115 enum ip_conntrack_info ctinfo
,
1116 const struct sk_buff
*skb
,
1120 struct nf_conn_counter
*acct
;
1122 acct
= nf_conn_acct_find(ct
);
1124 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1125 atomic64_add(skb
->len
- skb_network_offset(skb
),
1126 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1130 if (del_timer(&ct
->timeout
)) {
1131 ct
->timeout
.function((unsigned long)ct
);
1136 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1138 #ifdef CONFIG_NF_CONNTRACK_ZONES
1139 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1140 .len
= sizeof(struct nf_conntrack_zone
),
1141 .align
= __alignof__(struct nf_conntrack_zone
),
1142 .id
= NF_CT_EXT_ZONE
,
1146 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1148 #include <linux/netfilter/nfnetlink.h>
1149 #include <linux/netfilter/nfnetlink_conntrack.h>
1150 #include <linux/mutex.h>
1152 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1153 * in ip_conntrack_core, since we don't want the protocols to autoload
1154 * or depend on ctnetlink */
1155 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1156 const struct nf_conntrack_tuple
*tuple
)
1158 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1159 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1160 goto nla_put_failure
;
1166 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1168 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1169 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1170 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1172 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1174 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1175 struct nf_conntrack_tuple
*t
)
1177 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1180 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1181 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1185 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1187 int nf_ct_port_nlattr_tuple_size(void)
1189 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1191 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1194 /* Used by ipt_REJECT and ip6t_REJECT. */
1195 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1198 enum ip_conntrack_info ctinfo
;
1200 /* This ICMP is in reverse direction to the packet which caused it */
1201 ct
= nf_ct_get(skb
, &ctinfo
);
1202 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1203 ctinfo
= IP_CT_RELATED_REPLY
;
1205 ctinfo
= IP_CT_RELATED
;
1207 /* Attach to new skbuff, and increment count */
1208 nskb
->nfct
= &ct
->ct_general
;
1209 nskb
->nfctinfo
= ctinfo
;
1210 nf_conntrack_get(nskb
->nfct
);
1213 /* Bring out ya dead! */
1214 static struct nf_conn
*
1215 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1216 void *data
, unsigned int *bucket
)
1218 struct nf_conntrack_tuple_hash
*h
;
1220 struct hlist_nulls_node
*n
;
1222 spin_lock_bh(&nf_conntrack_lock
);
1223 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1224 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1225 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1227 ct
= nf_ct_tuplehash_to_ctrack(h
);
1232 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1233 ct
= nf_ct_tuplehash_to_ctrack(h
);
1235 set_bit(IPS_DYING_BIT
, &ct
->status
);
1237 spin_unlock_bh(&nf_conntrack_lock
);
1240 atomic_inc(&ct
->ct_general
.use
);
1241 spin_unlock_bh(&nf_conntrack_lock
);
1245 void nf_ct_iterate_cleanup(struct net
*net
,
1246 int (*iter
)(struct nf_conn
*i
, void *data
),
1250 unsigned int bucket
= 0;
1252 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1253 /* Time to push up daises... */
1254 if (del_timer(&ct
->timeout
))
1255 death_by_timeout((unsigned long)ct
);
1256 /* ... else the timer will get him soon. */
1261 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1263 struct __nf_ct_flush_report
{
1268 static int kill_report(struct nf_conn
*i
, void *data
)
1270 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1271 struct nf_conn_tstamp
*tstamp
;
1273 tstamp
= nf_conn_tstamp_find(i
);
1274 if (tstamp
&& tstamp
->stop
== 0)
1275 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1277 /* If we fail to deliver the event, death_by_timeout() will retry */
1278 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1279 fr
->portid
, fr
->report
) < 0)
1282 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1283 set_bit(IPS_DYING_BIT
, &i
->status
);
1287 static int kill_all(struct nf_conn
*i
, void *data
)
1292 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1294 if (is_vmalloc_addr(hash
))
1297 free_pages((unsigned long)hash
,
1298 get_order(sizeof(struct hlist_head
) * size
));
1300 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1302 void nf_conntrack_flush_report(struct net
*net
, u32 portid
, int report
)
1304 struct __nf_ct_flush_report fr
= {
1308 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1310 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1312 static void nf_ct_release_dying_list(struct net
*net
)
1314 struct nf_conntrack_tuple_hash
*h
;
1316 struct hlist_nulls_node
*n
;
1318 spin_lock_bh(&nf_conntrack_lock
);
1319 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1320 ct
= nf_ct_tuplehash_to_ctrack(h
);
1321 /* never fails to remove them, no listeners at this point */
1324 spin_unlock_bh(&nf_conntrack_lock
);
1327 static int untrack_refs(void)
1331 for_each_possible_cpu(cpu
) {
1332 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1334 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1339 void nf_conntrack_cleanup_start(void)
1341 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1344 void nf_conntrack_cleanup_end(void)
1346 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1347 while (untrack_refs() > 0)
1350 #ifdef CONFIG_NF_CONNTRACK_ZONES
1351 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1353 nf_conntrack_proto_fini();
1354 nf_conntrack_labels_fini();
1355 nf_conntrack_helper_fini();
1356 nf_conntrack_timeout_fini();
1357 nf_conntrack_ecache_fini();
1358 nf_conntrack_tstamp_fini();
1359 nf_conntrack_acct_fini();
1360 nf_conntrack_expect_fini();
1364 * Mishearing the voices in his head, our hero wonders how he's
1365 * supposed to kill the mall.
1367 void nf_conntrack_cleanup_net(struct net
*net
)
1371 list_add(&net
->exit_list
, &single
);
1372 nf_conntrack_cleanup_net_list(&single
);
1375 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1381 * This makes sure all current packets have passed through
1382 * netfilter framework. Roll on, two-stage module
1388 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1389 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1390 nf_ct_release_dying_list(net
);
1391 if (atomic_read(&net
->ct
.count
) != 0)
1396 goto i_see_dead_people
;
1399 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1400 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1401 nf_conntrack_proto_pernet_fini(net
);
1402 nf_conntrack_helper_pernet_fini(net
);
1403 nf_conntrack_ecache_pernet_fini(net
);
1404 nf_conntrack_tstamp_pernet_fini(net
);
1405 nf_conntrack_acct_pernet_fini(net
);
1406 nf_conntrack_expect_pernet_fini(net
);
1407 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1408 kfree(net
->ct
.slabname
);
1409 free_percpu(net
->ct
.stat
);
1413 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1415 struct hlist_nulls_head
*hash
;
1416 unsigned int nr_slots
, i
;
1419 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1420 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1421 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1422 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1425 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1430 for (i
= 0; i
< nr_slots
; i
++)
1431 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1435 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1437 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1440 unsigned int hashsize
, old_size
;
1441 struct hlist_nulls_head
*hash
, *old_hash
;
1442 struct nf_conntrack_tuple_hash
*h
;
1445 if (current
->nsproxy
->net_ns
!= &init_net
)
1448 /* On boot, we can set this without any fancy locking. */
1449 if (!nf_conntrack_htable_size
)
1450 return param_set_uint(val
, kp
);
1452 rc
= kstrtouint(val
, 0, &hashsize
);
1458 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1462 /* Lookups in the old hash might happen in parallel, which means we
1463 * might get false negatives during connection lookup. New connections
1464 * created because of a false negative won't make it into the hash
1465 * though since that required taking the lock.
1467 spin_lock_bh(&nf_conntrack_lock
);
1468 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1469 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1470 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1471 struct nf_conntrack_tuple_hash
, hnnode
);
1472 ct
= nf_ct_tuplehash_to_ctrack(h
);
1473 hlist_nulls_del_rcu(&h
->hnnode
);
1474 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1476 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1479 old_size
= init_net
.ct
.htable_size
;
1480 old_hash
= init_net
.ct
.hash
;
1482 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1483 init_net
.ct
.hash
= hash
;
1484 spin_unlock_bh(&nf_conntrack_lock
);
1486 nf_ct_free_hashtable(old_hash
, old_size
);
1489 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1491 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1492 &nf_conntrack_htable_size
, 0600);
1494 void nf_ct_untracked_status_or(unsigned long bits
)
1498 for_each_possible_cpu(cpu
)
1499 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1501 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1503 int nf_conntrack_init_start(void)
1508 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1509 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1510 if (!nf_conntrack_htable_size
) {
1511 nf_conntrack_htable_size
1512 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1513 / sizeof(struct hlist_head
));
1514 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1515 nf_conntrack_htable_size
= 16384;
1516 if (nf_conntrack_htable_size
< 32)
1517 nf_conntrack_htable_size
= 32;
1519 /* Use a max. factor of four by default to get the same max as
1520 * with the old struct list_heads. When a table size is given
1521 * we use the old value of 8 to avoid reducing the max.
1525 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1527 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1528 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1531 ret
= nf_conntrack_expect_init();
1535 ret
= nf_conntrack_acct_init();
1539 ret
= nf_conntrack_tstamp_init();
1543 ret
= nf_conntrack_ecache_init();
1547 ret
= nf_conntrack_timeout_init();
1551 ret
= nf_conntrack_helper_init();
1555 ret
= nf_conntrack_labels_init();
1559 #ifdef CONFIG_NF_CONNTRACK_ZONES
1560 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1564 ret
= nf_conntrack_proto_init();
1568 /* Set up fake conntrack: to never be deleted, not in any hashes */
1569 for_each_possible_cpu(cpu
) {
1570 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1571 write_pnet(&ct
->ct_net
, &init_net
);
1572 atomic_set(&ct
->ct_general
.use
, 1);
1574 /* - and look it like as a confirmed connection */
1575 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1579 #ifdef CONFIG_NF_CONNTRACK_ZONES
1580 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1583 nf_conntrack_labels_fini();
1585 nf_conntrack_helper_fini();
1587 nf_conntrack_timeout_fini();
1589 nf_conntrack_ecache_fini();
1591 nf_conntrack_tstamp_fini();
1593 nf_conntrack_acct_fini();
1595 nf_conntrack_expect_fini();
1600 void nf_conntrack_init_end(void)
1602 /* For use by REJECT target */
1603 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1604 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1606 /* Howto get NAT offsets */
1607 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
1611 * We need to use special "null" values, not used in hash table
1613 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1614 #define DYING_NULLS_VAL ((1<<30)+1)
1615 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1617 int nf_conntrack_init_net(struct net
*net
)
1621 atomic_set(&net
->ct
.count
, 0);
1622 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1623 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1624 INIT_HLIST_NULLS_HEAD(&net
->ct
.tmpl
, TEMPLATE_NULLS_VAL
);
1625 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1626 if (!net
->ct
.stat
) {
1631 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1632 if (!net
->ct
.slabname
) {
1637 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1638 sizeof(struct nf_conn
), 0,
1639 SLAB_DESTROY_BY_RCU
, NULL
);
1640 if (!net
->ct
.nf_conntrack_cachep
) {
1641 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1646 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1647 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1648 if (!net
->ct
.hash
) {
1650 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1653 ret
= nf_conntrack_expect_pernet_init(net
);
1656 ret
= nf_conntrack_acct_pernet_init(net
);
1659 ret
= nf_conntrack_tstamp_pernet_init(net
);
1662 ret
= nf_conntrack_ecache_pernet_init(net
);
1665 ret
= nf_conntrack_helper_pernet_init(net
);
1668 ret
= nf_conntrack_proto_pernet_init(net
);
1674 nf_conntrack_helper_pernet_fini(net
);
1676 nf_conntrack_ecache_pernet_fini(net
);
1678 nf_conntrack_tstamp_pernet_fini(net
);
1680 nf_conntrack_acct_pernet_fini(net
);
1682 nf_conntrack_expect_pernet_fini(net
);
1684 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1686 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1688 kfree(net
->ct
.slabname
);
1690 free_percpu(net
->ct
.stat
);
1695 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1696 enum ip_conntrack_dir dir
,
1698 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);