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 int (*nf_nat_seq_adjust_hook
)(struct sk_buff
*skb
,
65 enum ip_conntrack_info ctinfo
,
66 unsigned int protoff
);
67 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook
);
69 DEFINE_SPINLOCK(nf_conntrack_lock
);
70 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
72 unsigned int nf_conntrack_htable_size __read_mostly
;
73 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
75 unsigned int nf_conntrack_max __read_mostly
;
76 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
78 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
79 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
81 unsigned int nf_conntrack_hash_rnd __read_mostly
;
82 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
84 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
88 /* The direction must be ignored, so we hash everything up to the
89 * destination ports (which is a multiple of 4) and treat the last
90 * three bytes manually.
92 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
93 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
94 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
95 tuple
->dst
.protonum
));
98 static u32
__hash_bucket(u32 hash
, unsigned int size
)
100 return ((u64
)hash
* size
) >> 32;
103 static u32
hash_bucket(u32 hash
, const struct net
*net
)
105 return __hash_bucket(hash
, net
->ct
.htable_size
);
108 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
109 u16 zone
, unsigned int size
)
111 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
114 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
115 const struct nf_conntrack_tuple
*tuple
)
117 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
121 nf_ct_get_tuple(const struct sk_buff
*skb
,
123 unsigned int dataoff
,
126 struct nf_conntrack_tuple
*tuple
,
127 const struct nf_conntrack_l3proto
*l3proto
,
128 const struct nf_conntrack_l4proto
*l4proto
)
130 memset(tuple
, 0, sizeof(*tuple
));
132 tuple
->src
.l3num
= l3num
;
133 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
136 tuple
->dst
.protonum
= protonum
;
137 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
139 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
141 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
143 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
144 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
146 struct nf_conntrack_l3proto
*l3proto
;
147 struct nf_conntrack_l4proto
*l4proto
;
148 unsigned int protoff
;
154 l3proto
= __nf_ct_l3proto_find(l3num
);
155 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
156 if (ret
!= NF_ACCEPT
) {
161 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
163 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
169 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
172 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
173 const struct nf_conntrack_tuple
*orig
,
174 const struct nf_conntrack_l3proto
*l3proto
,
175 const struct nf_conntrack_l4proto
*l4proto
)
177 memset(inverse
, 0, sizeof(*inverse
));
179 inverse
->src
.l3num
= orig
->src
.l3num
;
180 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
183 inverse
->dst
.dir
= !orig
->dst
.dir
;
185 inverse
->dst
.protonum
= orig
->dst
.protonum
;
186 return l4proto
->invert_tuple(inverse
, orig
);
188 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
191 clean_from_lists(struct nf_conn
*ct
)
193 pr_debug("clean_from_lists(%p)\n", ct
);
194 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
195 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
197 /* Destroy all pending expectations */
198 nf_ct_remove_expectations(ct
);
202 destroy_conntrack(struct nf_conntrack
*nfct
)
204 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
205 struct net
*net
= nf_ct_net(ct
);
206 struct nf_conntrack_l4proto
*l4proto
;
208 pr_debug("destroy_conntrack(%p)\n", ct
);
209 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
210 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
212 /* To make sure we don't get any weird locking issues here:
213 * destroy_conntrack() MUST NOT be called with a write lock
214 * to nf_conntrack_lock!!! -HW */
216 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
217 if (l4proto
&& l4proto
->destroy
)
218 l4proto
->destroy(ct
);
222 spin_lock_bh(&nf_conntrack_lock
);
223 /* Expectations will have been removed in clean_from_lists,
224 * except TFTP can create an expectation on the first packet,
225 * before connection is in the list, so we need to clean here,
227 nf_ct_remove_expectations(ct
);
229 /* We overload first tuple to link into unconfirmed or dying list.*/
230 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
231 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
233 NF_CT_STAT_INC(net
, delete);
234 spin_unlock_bh(&nf_conntrack_lock
);
237 nf_ct_put(ct
->master
);
239 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
240 nf_conntrack_free(ct
);
243 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
245 struct net
*net
= nf_ct_net(ct
);
247 nf_ct_helper_destroy(ct
);
248 spin_lock_bh(&nf_conntrack_lock
);
249 /* Inside lock so preempt is disabled on module removal path.
250 * Otherwise we can get spurious warnings. */
251 NF_CT_STAT_INC(net
, delete_list
);
252 clean_from_lists(ct
);
253 /* add this conntrack to the dying list */
254 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
256 spin_unlock_bh(&nf_conntrack_lock
);
259 static void death_by_event(unsigned long ul_conntrack
)
261 struct nf_conn
*ct
= (void *)ul_conntrack
;
262 struct net
*net
= nf_ct_net(ct
);
263 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
265 BUG_ON(ecache
== NULL
);
267 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
268 /* bad luck, let's retry again */
269 ecache
->timeout
.expires
= jiffies
+
270 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
271 add_timer(&ecache
->timeout
);
274 /* we've got the event delivered, now it's dying */
275 set_bit(IPS_DYING_BIT
, &ct
->status
);
279 static void nf_ct_dying_timeout(struct nf_conn
*ct
)
281 struct net
*net
= nf_ct_net(ct
);
282 struct nf_conntrack_ecache
*ecache
= nf_ct_ecache_find(ct
);
284 BUG_ON(ecache
== NULL
);
286 /* set a new timer to retry event delivery */
287 setup_timer(&ecache
->timeout
, death_by_event
, (unsigned long)ct
);
288 ecache
->timeout
.expires
= jiffies
+
289 (prandom_u32() % net
->ct
.sysctl_events_retry_timeout
);
290 add_timer(&ecache
->timeout
);
293 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
295 struct nf_conn_tstamp
*tstamp
;
297 tstamp
= nf_conn_tstamp_find(ct
);
298 if (tstamp
&& tstamp
->stop
== 0)
299 tstamp
->stop
= ktime_to_ns(ktime_get_real());
301 if (!nf_ct_is_dying(ct
) &&
302 unlikely(nf_conntrack_event_report(IPCT_DESTROY
, ct
,
303 portid
, report
) < 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
);
314 EXPORT_SYMBOL_GPL(nf_ct_delete
);
316 static void death_by_timeout(unsigned long ul_conntrack
)
318 nf_ct_delete((struct nf_conn
*)ul_conntrack
, 0, 0);
323 * - Caller must take a reference on returned object
324 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
326 * - Caller must lock nf_conntrack_lock before calling this function
328 static struct nf_conntrack_tuple_hash
*
329 ____nf_conntrack_find(struct net
*net
, u16 zone
,
330 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
332 struct nf_conntrack_tuple_hash
*h
;
333 struct hlist_nulls_node
*n
;
334 unsigned int bucket
= hash_bucket(hash
, net
);
336 /* Disable BHs the entire time since we normally need to disable them
337 * at least once for the stats anyway.
341 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
342 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
343 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
344 NF_CT_STAT_INC(net
, found
);
348 NF_CT_STAT_INC(net
, searched
);
351 * if the nulls value we got at the end of this lookup is
352 * not the expected one, we must restart lookup.
353 * We probably met an item that was moved to another chain.
355 if (get_nulls_value(n
) != bucket
) {
356 NF_CT_STAT_INC(net
, search_restart
);
364 struct nf_conntrack_tuple_hash
*
365 __nf_conntrack_find(struct net
*net
, u16 zone
,
366 const struct nf_conntrack_tuple
*tuple
)
368 return ____nf_conntrack_find(net
, zone
, tuple
,
369 hash_conntrack_raw(tuple
, zone
));
371 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
373 /* Find a connection corresponding to a tuple. */
374 static struct nf_conntrack_tuple_hash
*
375 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
376 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
378 struct nf_conntrack_tuple_hash
*h
;
383 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
385 ct
= nf_ct_tuplehash_to_ctrack(h
);
386 if (unlikely(nf_ct_is_dying(ct
) ||
387 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
390 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
391 nf_ct_zone(ct
) != zone
)) {
402 struct nf_conntrack_tuple_hash
*
403 nf_conntrack_find_get(struct net
*net
, u16 zone
,
404 const struct nf_conntrack_tuple
*tuple
)
406 return __nf_conntrack_find_get(net
, zone
, tuple
,
407 hash_conntrack_raw(tuple
, zone
));
409 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
411 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
413 unsigned int repl_hash
)
415 struct net
*net
= nf_ct_net(ct
);
417 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
418 &net
->ct
.hash
[hash
]);
419 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
420 &net
->ct
.hash
[repl_hash
]);
424 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
426 struct net
*net
= nf_ct_net(ct
);
427 unsigned int hash
, repl_hash
;
428 struct nf_conntrack_tuple_hash
*h
;
429 struct hlist_nulls_node
*n
;
432 zone
= nf_ct_zone(ct
);
433 hash
= hash_conntrack(net
, zone
,
434 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
435 repl_hash
= hash_conntrack(net
, zone
,
436 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
438 spin_lock_bh(&nf_conntrack_lock
);
440 /* See if there's one in the list already, including reverse */
441 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
442 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
444 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
446 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
447 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
449 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
452 add_timer(&ct
->timeout
);
453 nf_conntrack_get(&ct
->ct_general
);
454 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
455 NF_CT_STAT_INC(net
, insert
);
456 spin_unlock_bh(&nf_conntrack_lock
);
461 NF_CT_STAT_INC(net
, insert_failed
);
462 spin_unlock_bh(&nf_conntrack_lock
);
465 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
467 /* Confirm a connection given skb; places it in hash table */
469 __nf_conntrack_confirm(struct sk_buff
*skb
)
471 unsigned int hash
, repl_hash
;
472 struct nf_conntrack_tuple_hash
*h
;
474 struct nf_conn_help
*help
;
475 struct nf_conn_tstamp
*tstamp
;
476 struct hlist_nulls_node
*n
;
477 enum ip_conntrack_info ctinfo
;
481 ct
= nf_ct_get(skb
, &ctinfo
);
484 /* ipt_REJECT uses nf_conntrack_attach to attach related
485 ICMP/TCP RST packets in other direction. Actual packet
486 which created connection will be IP_CT_NEW or for an
487 expected connection, IP_CT_RELATED. */
488 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
491 zone
= nf_ct_zone(ct
);
492 /* reuse the hash saved before */
493 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
494 hash
= hash_bucket(hash
, net
);
495 repl_hash
= hash_conntrack(net
, zone
,
496 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
498 /* We're not in hash table, and we refuse to set up related
499 connections for unconfirmed conns. But packet copies and
500 REJECT will give spurious warnings here. */
501 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
503 /* No external references means no one else could have
505 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
506 pr_debug("Confirming conntrack %p\n", ct
);
508 spin_lock_bh(&nf_conntrack_lock
);
510 /* We have to check the DYING flag inside the lock to prevent
511 a race against nf_ct_get_next_corpse() possibly called from
512 user context, else we insert an already 'dead' hash, blocking
513 further use of that particular connection -JM */
515 if (unlikely(nf_ct_is_dying(ct
))) {
516 spin_unlock_bh(&nf_conntrack_lock
);
520 /* See if there's one in the list already, including reverse:
521 NAT could have grabbed it without realizing, since we're
522 not in the hash. If there is, we lost race. */
523 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
524 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
526 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
528 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
529 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
531 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
534 /* Remove from unconfirmed list */
535 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
537 /* Timer relative to confirmation time, not original
538 setting time, otherwise we'd get timer wrap in
539 weird delay cases. */
540 ct
->timeout
.expires
+= jiffies
;
541 add_timer(&ct
->timeout
);
542 atomic_inc(&ct
->ct_general
.use
);
543 ct
->status
|= IPS_CONFIRMED
;
545 /* set conntrack timestamp, if enabled. */
546 tstamp
= nf_conn_tstamp_find(ct
);
548 if (skb
->tstamp
.tv64
== 0)
549 __net_timestamp(skb
);
551 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
553 /* Since the lookup is lockless, hash insertion must be done after
554 * starting the timer and setting the CONFIRMED bit. The RCU barriers
555 * guarantee that no other CPU can find the conntrack before the above
556 * stores are visible.
558 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
559 NF_CT_STAT_INC(net
, insert
);
560 spin_unlock_bh(&nf_conntrack_lock
);
562 help
= nfct_help(ct
);
563 if (help
&& help
->helper
)
564 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
566 nf_conntrack_event_cache(master_ct(ct
) ?
567 IPCT_RELATED
: IPCT_NEW
, ct
);
571 NF_CT_STAT_INC(net
, insert_failed
);
572 spin_unlock_bh(&nf_conntrack_lock
);
575 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
577 /* Returns true if a connection correspondings to the tuple (required
580 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
581 const struct nf_conn
*ignored_conntrack
)
583 struct net
*net
= nf_ct_net(ignored_conntrack
);
584 struct nf_conntrack_tuple_hash
*h
;
585 struct hlist_nulls_node
*n
;
587 u16 zone
= nf_ct_zone(ignored_conntrack
);
588 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
590 /* Disable BHs the entire time since we need to disable them at
591 * least once for the stats anyway.
594 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
595 ct
= nf_ct_tuplehash_to_ctrack(h
);
596 if (ct
!= ignored_conntrack
&&
597 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
598 nf_ct_zone(ct
) == zone
) {
599 NF_CT_STAT_INC(net
, found
);
600 rcu_read_unlock_bh();
603 NF_CT_STAT_INC(net
, searched
);
605 rcu_read_unlock_bh();
609 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
611 #define NF_CT_EVICTION_RANGE 8
613 /* There's a small race here where we may free a just-assured
614 connection. Too bad: we're in trouble anyway. */
615 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
617 /* Use oldest entry, which is roughly LRU */
618 struct nf_conntrack_tuple_hash
*h
;
619 struct nf_conn
*ct
= NULL
, *tmp
;
620 struct hlist_nulls_node
*n
;
621 unsigned int i
, cnt
= 0;
625 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
626 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
628 tmp
= nf_ct_tuplehash_to_ctrack(h
);
629 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
635 if (likely(!nf_ct_is_dying(ct
) &&
636 atomic_inc_not_zero(&ct
->ct_general
.use
)))
642 if (cnt
>= NF_CT_EVICTION_RANGE
)
645 hash
= (hash
+ 1) % net
->ct
.htable_size
;
652 if (del_timer(&ct
->timeout
)) {
653 if (nf_ct_delete(ct
, 0, 0)) {
655 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
662 void init_nf_conntrack_hash_rnd(void)
667 * Why not initialize nf_conntrack_rnd in a "init()" function ?
668 * Because there isn't enough entropy when system initializing,
669 * and we initialize it as late as possible.
672 get_random_bytes(&rand
, sizeof(rand
));
674 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
677 static struct nf_conn
*
678 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
679 const struct nf_conntrack_tuple
*orig
,
680 const struct nf_conntrack_tuple
*repl
,
685 if (unlikely(!nf_conntrack_hash_rnd
)) {
686 init_nf_conntrack_hash_rnd();
687 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
688 hash
= hash_conntrack_raw(orig
, zone
);
691 /* We don't want any race condition at early drop stage */
692 atomic_inc(&net
->ct
.count
);
694 if (nf_conntrack_max
&&
695 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
696 if (!early_drop(net
, hash_bucket(hash
, net
))) {
697 atomic_dec(&net
->ct
.count
);
698 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
699 return ERR_PTR(-ENOMEM
);
704 * Do not use kmem_cache_zalloc(), as this cache uses
705 * SLAB_DESTROY_BY_RCU.
707 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
709 atomic_dec(&net
->ct
.count
);
710 return ERR_PTR(-ENOMEM
);
713 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
714 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
716 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
717 offsetof(struct nf_conn
, proto
) -
718 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
719 spin_lock_init(&ct
->lock
);
720 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
721 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
722 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
723 /* save hash for reusing when confirming */
724 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
725 /* Don't set timer yet: wait for confirmation */
726 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
727 write_pnet(&ct
->ct_net
, net
);
728 #ifdef CONFIG_NF_CONNTRACK_ZONES
730 struct nf_conntrack_zone
*nf_ct_zone
;
732 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
735 nf_ct_zone
->id
= zone
;
739 * changes to lookup keys must be done before setting refcnt to 1
742 atomic_set(&ct
->ct_general
.use
, 1);
745 #ifdef CONFIG_NF_CONNTRACK_ZONES
747 atomic_dec(&net
->ct
.count
);
748 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
749 return ERR_PTR(-ENOMEM
);
753 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
754 const struct nf_conntrack_tuple
*orig
,
755 const struct nf_conntrack_tuple
*repl
,
758 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
760 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
762 void nf_conntrack_free(struct nf_conn
*ct
)
764 struct net
*net
= nf_ct_net(ct
);
766 nf_ct_ext_destroy(ct
);
767 atomic_dec(&net
->ct
.count
);
769 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
771 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
774 /* Allocate a new conntrack: we return -ENOMEM if classification
775 failed due to stress. Otherwise it really is unclassifiable. */
776 static struct nf_conntrack_tuple_hash
*
777 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
778 const struct nf_conntrack_tuple
*tuple
,
779 struct nf_conntrack_l3proto
*l3proto
,
780 struct nf_conntrack_l4proto
*l4proto
,
782 unsigned int dataoff
, u32 hash
)
785 struct nf_conn_help
*help
;
786 struct nf_conntrack_tuple repl_tuple
;
787 struct nf_conntrack_ecache
*ecache
;
788 struct nf_conntrack_expect
*exp
;
789 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
790 struct nf_conn_timeout
*timeout_ext
;
791 unsigned int *timeouts
;
793 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
794 pr_debug("Can't invert tuple.\n");
798 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
801 return (struct nf_conntrack_tuple_hash
*)ct
;
803 if (tmpl
&& nfct_synproxy(tmpl
)) {
804 nfct_seqadj_ext_add(ct
);
805 nfct_synproxy_ext_add(ct
);
808 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
810 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
812 timeouts
= l4proto
->get_timeouts(net
);
814 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
815 nf_conntrack_free(ct
);
816 pr_debug("init conntrack: can't track with proto module\n");
821 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
823 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
824 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
825 nf_ct_labels_ext_add(ct
);
827 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
828 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
829 ecache
? ecache
->expmask
: 0,
832 spin_lock_bh(&nf_conntrack_lock
);
833 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
835 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
837 /* Welcome, Mr. Bond. We've been expecting you... */
838 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
839 ct
->master
= exp
->master
;
841 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
844 rcu_assign_pointer(help
->helper
, exp
->helper
);
847 #ifdef CONFIG_NF_CONNTRACK_MARK
848 ct
->mark
= exp
->master
->mark
;
850 #ifdef CONFIG_NF_CONNTRACK_SECMARK
851 ct
->secmark
= exp
->master
->secmark
;
853 nf_conntrack_get(&ct
->master
->ct_general
);
854 NF_CT_STAT_INC(net
, expect_new
);
856 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
857 NF_CT_STAT_INC(net
, new);
860 /* Overload tuple linked list to put us in unconfirmed list. */
861 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
862 &net
->ct
.unconfirmed
);
864 spin_unlock_bh(&nf_conntrack_lock
);
868 exp
->expectfn(ct
, exp
);
869 nf_ct_expect_put(exp
);
872 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
875 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
876 static inline struct nf_conn
*
877 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
879 unsigned int dataoff
,
882 struct nf_conntrack_l3proto
*l3proto
,
883 struct nf_conntrack_l4proto
*l4proto
,
885 enum ip_conntrack_info
*ctinfo
)
887 struct nf_conntrack_tuple tuple
;
888 struct nf_conntrack_tuple_hash
*h
;
890 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
893 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
894 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
896 pr_debug("resolve_normal_ct: Can't get tuple\n");
900 /* look for tuple match */
901 hash
= hash_conntrack_raw(&tuple
, zone
);
902 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
904 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
911 ct
= nf_ct_tuplehash_to_ctrack(h
);
913 /* It exists; we have (non-exclusive) reference. */
914 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
915 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
916 /* Please set reply bit if this packet OK */
919 /* Once we've had two way comms, always ESTABLISHED. */
920 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
921 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
922 *ctinfo
= IP_CT_ESTABLISHED
;
923 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
924 pr_debug("nf_conntrack_in: related packet for %p\n",
926 *ctinfo
= IP_CT_RELATED
;
928 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
933 skb
->nfct
= &ct
->ct_general
;
934 skb
->nfctinfo
= *ctinfo
;
939 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
942 struct nf_conn
*ct
, *tmpl
= NULL
;
943 enum ip_conntrack_info ctinfo
;
944 struct nf_conntrack_l3proto
*l3proto
;
945 struct nf_conntrack_l4proto
*l4proto
;
946 unsigned int *timeouts
;
947 unsigned int dataoff
;
953 /* Previously seen (loopback or untracked)? Ignore. */
954 tmpl
= (struct nf_conn
*)skb
->nfct
;
955 if (!nf_ct_is_template(tmpl
)) {
956 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
962 /* rcu_read_lock()ed by nf_hook_slow */
963 l3proto
= __nf_ct_l3proto_find(pf
);
964 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
965 &dataoff
, &protonum
);
967 pr_debug("not prepared to track yet or error occurred\n");
968 NF_CT_STAT_INC_ATOMIC(net
, error
);
969 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
974 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
976 /* It may be an special packet, error, unclean...
977 * inverse of the return code tells to the netfilter
978 * core what to do with the packet. */
979 if (l4proto
->error
!= NULL
) {
980 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
983 NF_CT_STAT_INC_ATOMIC(net
, error
);
984 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
988 /* ICMP[v6] protocol trackers may assign one conntrack. */
993 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
994 l3proto
, l4proto
, &set_reply
, &ctinfo
);
996 /* Not valid part of a connection */
997 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1003 /* Too stressed to deal. */
1004 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1009 NF_CT_ASSERT(skb
->nfct
);
1011 /* Decide what timeout policy we want to apply to this flow. */
1012 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1014 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1016 /* Invalid: inverse of the return code tells
1017 * the netfilter core what to do */
1018 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1019 nf_conntrack_put(skb
->nfct
);
1021 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1022 if (ret
== -NF_DROP
)
1023 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1028 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1029 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1032 /* Special case: we have to repeat this hook, assign the
1033 * template again to this packet. We assume that this packet
1034 * has no conntrack assigned. This is used by nf_ct_tcp. */
1035 if (ret
== NF_REPEAT
)
1036 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1043 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1045 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1046 const struct nf_conntrack_tuple
*orig
)
1051 ret
= nf_ct_invert_tuple(inverse
, orig
,
1052 __nf_ct_l3proto_find(orig
->src
.l3num
),
1053 __nf_ct_l4proto_find(orig
->src
.l3num
,
1054 orig
->dst
.protonum
));
1058 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1060 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1061 implicitly racy: see __nf_conntrack_confirm */
1062 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1063 const struct nf_conntrack_tuple
*newreply
)
1065 struct nf_conn_help
*help
= nfct_help(ct
);
1067 /* Should be unconfirmed, so not in hash table yet */
1068 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1070 pr_debug("Altering reply tuple of %p to ", ct
);
1071 nf_ct_dump_tuple(newreply
);
1073 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1074 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1078 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1081 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1083 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1084 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1085 enum ip_conntrack_info ctinfo
,
1086 const struct sk_buff
*skb
,
1087 unsigned long extra_jiffies
,
1090 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1093 /* Only update if this is not a fixed timeout */
1094 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1097 /* If not in hash table, timer will not be active yet */
1098 if (!nf_ct_is_confirmed(ct
)) {
1099 ct
->timeout
.expires
= extra_jiffies
;
1101 unsigned long newtime
= jiffies
+ extra_jiffies
;
1103 /* Only update the timeout if the new timeout is at least
1104 HZ jiffies from the old timeout. Need del_timer for race
1105 avoidance (may already be dying). */
1106 if (newtime
- ct
->timeout
.expires
>= HZ
)
1107 mod_timer_pending(&ct
->timeout
, newtime
);
1112 struct nf_conn_counter
*acct
;
1114 acct
= nf_conn_acct_find(ct
);
1116 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1117 atomic64_add(skb
->len
, &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1121 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1123 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1124 enum ip_conntrack_info ctinfo
,
1125 const struct sk_buff
*skb
,
1129 struct nf_conn_counter
*acct
;
1131 acct
= nf_conn_acct_find(ct
);
1133 atomic64_inc(&acct
[CTINFO2DIR(ctinfo
)].packets
);
1134 atomic64_add(skb
->len
- skb_network_offset(skb
),
1135 &acct
[CTINFO2DIR(ctinfo
)].bytes
);
1139 if (del_timer(&ct
->timeout
)) {
1140 ct
->timeout
.function((unsigned long)ct
);
1145 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1147 #ifdef CONFIG_NF_CONNTRACK_ZONES
1148 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1149 .len
= sizeof(struct nf_conntrack_zone
),
1150 .align
= __alignof__(struct nf_conntrack_zone
),
1151 .id
= NF_CT_EXT_ZONE
,
1155 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1157 #include <linux/netfilter/nfnetlink.h>
1158 #include <linux/netfilter/nfnetlink_conntrack.h>
1159 #include <linux/mutex.h>
1161 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1162 * in ip_conntrack_core, since we don't want the protocols to autoload
1163 * or depend on ctnetlink */
1164 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1165 const struct nf_conntrack_tuple
*tuple
)
1167 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1168 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1169 goto nla_put_failure
;
1175 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1177 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1178 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1179 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1181 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1183 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1184 struct nf_conntrack_tuple
*t
)
1186 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1189 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1190 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1194 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1196 int nf_ct_port_nlattr_tuple_size(void)
1198 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1200 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1203 /* Used by ipt_REJECT and ip6t_REJECT. */
1204 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1207 enum ip_conntrack_info ctinfo
;
1209 /* This ICMP is in reverse direction to the packet which caused it */
1210 ct
= nf_ct_get(skb
, &ctinfo
);
1211 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1212 ctinfo
= IP_CT_RELATED_REPLY
;
1214 ctinfo
= IP_CT_RELATED
;
1216 /* Attach to new skbuff, and increment count */
1217 nskb
->nfct
= &ct
->ct_general
;
1218 nskb
->nfctinfo
= ctinfo
;
1219 nf_conntrack_get(nskb
->nfct
);
1222 /* Bring out ya dead! */
1223 static struct nf_conn
*
1224 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1225 void *data
, unsigned int *bucket
)
1227 struct nf_conntrack_tuple_hash
*h
;
1229 struct hlist_nulls_node
*n
;
1231 spin_lock_bh(&nf_conntrack_lock
);
1232 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1233 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1234 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1236 ct
= nf_ct_tuplehash_to_ctrack(h
);
1241 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1242 ct
= nf_ct_tuplehash_to_ctrack(h
);
1244 set_bit(IPS_DYING_BIT
, &ct
->status
);
1246 spin_unlock_bh(&nf_conntrack_lock
);
1249 atomic_inc(&ct
->ct_general
.use
);
1250 spin_unlock_bh(&nf_conntrack_lock
);
1254 void nf_ct_iterate_cleanup(struct net
*net
,
1255 int (*iter
)(struct nf_conn
*i
, void *data
),
1256 void *data
, u32 portid
, int report
)
1259 unsigned int bucket
= 0;
1261 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1262 /* Time to push up daises... */
1263 if (del_timer(&ct
->timeout
))
1264 nf_ct_delete(ct
, portid
, report
);
1266 /* ... else the timer will get him soon. */
1271 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1273 static int kill_all(struct nf_conn
*i
, void *data
)
1278 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1280 if (is_vmalloc_addr(hash
))
1283 free_pages((unsigned long)hash
,
1284 get_order(sizeof(struct hlist_head
) * size
));
1286 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1288 void nf_conntrack_flush_report(struct net
*net
, u32 portid
, int report
)
1290 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, portid
, report
);
1292 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1294 static void nf_ct_release_dying_list(struct net
*net
)
1296 struct nf_conntrack_tuple_hash
*h
;
1298 struct hlist_nulls_node
*n
;
1300 spin_lock_bh(&nf_conntrack_lock
);
1301 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1302 ct
= nf_ct_tuplehash_to_ctrack(h
);
1303 /* never fails to remove them, no listeners at this point */
1306 spin_unlock_bh(&nf_conntrack_lock
);
1309 static int untrack_refs(void)
1313 for_each_possible_cpu(cpu
) {
1314 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1316 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1321 void nf_conntrack_cleanup_start(void)
1323 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1326 void nf_conntrack_cleanup_end(void)
1328 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1329 while (untrack_refs() > 0)
1332 #ifdef CONFIG_NF_CONNTRACK_ZONES
1333 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1335 nf_conntrack_proto_fini();
1336 nf_conntrack_seqadj_fini();
1337 nf_conntrack_labels_fini();
1338 nf_conntrack_helper_fini();
1339 nf_conntrack_timeout_fini();
1340 nf_conntrack_ecache_fini();
1341 nf_conntrack_tstamp_fini();
1342 nf_conntrack_acct_fini();
1343 nf_conntrack_expect_fini();
1347 * Mishearing the voices in his head, our hero wonders how he's
1348 * supposed to kill the mall.
1350 void nf_conntrack_cleanup_net(struct net
*net
)
1354 list_add(&net
->exit_list
, &single
);
1355 nf_conntrack_cleanup_net_list(&single
);
1358 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1364 * This makes sure all current packets have passed through
1365 * netfilter framework. Roll on, two-stage module
1371 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1372 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1373 nf_ct_release_dying_list(net
);
1374 if (atomic_read(&net
->ct
.count
) != 0)
1379 goto i_see_dead_people
;
1382 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1383 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1384 nf_conntrack_proto_pernet_fini(net
);
1385 nf_conntrack_helper_pernet_fini(net
);
1386 nf_conntrack_ecache_pernet_fini(net
);
1387 nf_conntrack_tstamp_pernet_fini(net
);
1388 nf_conntrack_acct_pernet_fini(net
);
1389 nf_conntrack_expect_pernet_fini(net
);
1390 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1391 kfree(net
->ct
.slabname
);
1392 free_percpu(net
->ct
.stat
);
1396 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1398 struct hlist_nulls_head
*hash
;
1399 unsigned int nr_slots
, i
;
1402 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1403 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1404 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1405 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1408 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1413 for (i
= 0; i
< nr_slots
; i
++)
1414 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1418 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1420 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1423 unsigned int hashsize
, old_size
;
1424 struct hlist_nulls_head
*hash
, *old_hash
;
1425 struct nf_conntrack_tuple_hash
*h
;
1428 if (current
->nsproxy
->net_ns
!= &init_net
)
1431 /* On boot, we can set this without any fancy locking. */
1432 if (!nf_conntrack_htable_size
)
1433 return param_set_uint(val
, kp
);
1435 rc
= kstrtouint(val
, 0, &hashsize
);
1441 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1445 /* Lookups in the old hash might happen in parallel, which means we
1446 * might get false negatives during connection lookup. New connections
1447 * created because of a false negative won't make it into the hash
1448 * though since that required taking the lock.
1450 spin_lock_bh(&nf_conntrack_lock
);
1451 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1452 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1453 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1454 struct nf_conntrack_tuple_hash
, hnnode
);
1455 ct
= nf_ct_tuplehash_to_ctrack(h
);
1456 hlist_nulls_del_rcu(&h
->hnnode
);
1457 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1459 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1462 old_size
= init_net
.ct
.htable_size
;
1463 old_hash
= init_net
.ct
.hash
;
1465 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1466 init_net
.ct
.hash
= hash
;
1467 spin_unlock_bh(&nf_conntrack_lock
);
1469 nf_ct_free_hashtable(old_hash
, old_size
);
1472 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1474 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1475 &nf_conntrack_htable_size
, 0600);
1477 void nf_ct_untracked_status_or(unsigned long bits
)
1481 for_each_possible_cpu(cpu
)
1482 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1484 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1486 int nf_conntrack_init_start(void)
1491 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1492 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1493 if (!nf_conntrack_htable_size
) {
1494 nf_conntrack_htable_size
1495 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1496 / sizeof(struct hlist_head
));
1497 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1498 nf_conntrack_htable_size
= 16384;
1499 if (nf_conntrack_htable_size
< 32)
1500 nf_conntrack_htable_size
= 32;
1502 /* Use a max. factor of four by default to get the same max as
1503 * with the old struct list_heads. When a table size is given
1504 * we use the old value of 8 to avoid reducing the max.
1508 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1510 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1511 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1514 ret
= nf_conntrack_expect_init();
1518 ret
= nf_conntrack_acct_init();
1522 ret
= nf_conntrack_tstamp_init();
1526 ret
= nf_conntrack_ecache_init();
1530 ret
= nf_conntrack_timeout_init();
1534 ret
= nf_conntrack_helper_init();
1538 ret
= nf_conntrack_labels_init();
1542 ret
= nf_conntrack_seqadj_init();
1546 #ifdef CONFIG_NF_CONNTRACK_ZONES
1547 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1551 ret
= nf_conntrack_proto_init();
1555 /* Set up fake conntrack: to never be deleted, not in any hashes */
1556 for_each_possible_cpu(cpu
) {
1557 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1558 write_pnet(&ct
->ct_net
, &init_net
);
1559 atomic_set(&ct
->ct_general
.use
, 1);
1561 /* - and look it like as a confirmed connection */
1562 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1566 #ifdef CONFIG_NF_CONNTRACK_ZONES
1567 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1570 nf_conntrack_seqadj_fini();
1572 nf_conntrack_labels_fini();
1574 nf_conntrack_helper_fini();
1576 nf_conntrack_timeout_fini();
1578 nf_conntrack_ecache_fini();
1580 nf_conntrack_tstamp_fini();
1582 nf_conntrack_acct_fini();
1584 nf_conntrack_expect_fini();
1589 void nf_conntrack_init_end(void)
1591 /* For use by REJECT target */
1592 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1593 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1597 * We need to use special "null" values, not used in hash table
1599 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1600 #define DYING_NULLS_VAL ((1<<30)+1)
1601 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1603 int nf_conntrack_init_net(struct net
*net
)
1607 atomic_set(&net
->ct
.count
, 0);
1608 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1609 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1610 INIT_HLIST_NULLS_HEAD(&net
->ct
.tmpl
, TEMPLATE_NULLS_VAL
);
1611 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1612 if (!net
->ct
.stat
) {
1617 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1618 if (!net
->ct
.slabname
) {
1623 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1624 sizeof(struct nf_conn
), 0,
1625 SLAB_DESTROY_BY_RCU
, NULL
);
1626 if (!net
->ct
.nf_conntrack_cachep
) {
1627 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1632 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1633 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1634 if (!net
->ct
.hash
) {
1636 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1639 ret
= nf_conntrack_expect_pernet_init(net
);
1642 ret
= nf_conntrack_acct_pernet_init(net
);
1645 ret
= nf_conntrack_tstamp_pernet_init(net
);
1648 ret
= nf_conntrack_ecache_pernet_init(net
);
1651 ret
= nf_conntrack_helper_pernet_init(net
);
1654 ret
= nf_conntrack_proto_pernet_init(net
);
1660 nf_conntrack_helper_pernet_fini(net
);
1662 nf_conntrack_ecache_pernet_fini(net
);
1664 nf_conntrack_tstamp_pernet_fini(net
);
1666 nf_conntrack_acct_pernet_fini(net
);
1668 nf_conntrack_expect_pernet_fini(net
);
1670 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1672 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1674 kfree(net
->ct
.slabname
);
1676 free_percpu(net
->ct
.stat
);