1 /* Connection state tracking for netfilter. This is separated from,
2 but required by, the NAT layer; it can also be used by an iptables
5 /* (C) 1999-2001 Paul `Rusty' Russell
6 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
7 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/skbuff.h>
19 #include <linux/proc_fs.h>
20 #include <linux/vmalloc.h>
21 #include <linux/stddef.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/jhash.h>
25 #include <linux/err.h>
26 #include <linux/percpu.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/kernel.h>
30 #include <linux/netdevice.h>
31 #include <linux/socket.h>
33 #include <linux/nsproxy.h>
34 #include <linux/rculist_nulls.h>
36 #include <net/netfilter/nf_conntrack.h>
37 #include <net/netfilter/nf_conntrack_l3proto.h>
38 #include <net/netfilter/nf_conntrack_l4proto.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_core.h>
42 #include <net/netfilter/nf_conntrack_extend.h>
43 #include <net/netfilter/nf_conntrack_acct.h>
44 #include <net/netfilter/nf_conntrack_ecache.h>
45 #include <net/netfilter/nf_conntrack_zones.h>
46 #include <net/netfilter/nf_conntrack_timestamp.h>
47 #include <net/netfilter/nf_nat.h>
48 #include <net/netfilter/nf_nat_core.h>
50 #define NF_CONNTRACK_VERSION "0.5.0"
52 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
53 enum nf_nat_manip_type manip
,
54 const struct nlattr
*attr
) __read_mostly
;
55 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
57 DEFINE_SPINLOCK(nf_conntrack_lock
);
58 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
60 unsigned int nf_conntrack_htable_size __read_mostly
;
61 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
63 unsigned int nf_conntrack_max __read_mostly
;
64 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
66 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
67 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
69 unsigned int nf_conntrack_hash_rnd __read_mostly
;
71 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
, u16 zone
)
75 /* The direction must be ignored, so we hash everything up to the
76 * destination ports (which is a multiple of 4) and treat the last
77 * three bytes manually.
79 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
80 return jhash2((u32
*)tuple
, n
, zone
^ nf_conntrack_hash_rnd
^
81 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
82 tuple
->dst
.protonum
));
85 static u32
__hash_bucket(u32 hash
, unsigned int size
)
87 return ((u64
)hash
* size
) >> 32;
90 static u32
hash_bucket(u32 hash
, const struct net
*net
)
92 return __hash_bucket(hash
, net
->ct
.htable_size
);
95 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
96 u16 zone
, unsigned int size
)
98 return __hash_bucket(hash_conntrack_raw(tuple
, zone
), size
);
101 static inline u_int32_t
hash_conntrack(const struct net
*net
, u16 zone
,
102 const struct nf_conntrack_tuple
*tuple
)
104 return __hash_conntrack(tuple
, zone
, net
->ct
.htable_size
);
108 nf_ct_get_tuple(const struct sk_buff
*skb
,
110 unsigned int dataoff
,
113 struct nf_conntrack_tuple
*tuple
,
114 const struct nf_conntrack_l3proto
*l3proto
,
115 const struct nf_conntrack_l4proto
*l4proto
)
117 memset(tuple
, 0, sizeof(*tuple
));
119 tuple
->src
.l3num
= l3num
;
120 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
123 tuple
->dst
.protonum
= protonum
;
124 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
126 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
128 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
130 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
131 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
133 struct nf_conntrack_l3proto
*l3proto
;
134 struct nf_conntrack_l4proto
*l4proto
;
135 unsigned int protoff
;
141 l3proto
= __nf_ct_l3proto_find(l3num
);
142 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
143 if (ret
!= NF_ACCEPT
) {
148 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
150 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
156 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
159 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
160 const struct nf_conntrack_tuple
*orig
,
161 const struct nf_conntrack_l3proto
*l3proto
,
162 const struct nf_conntrack_l4proto
*l4proto
)
164 memset(inverse
, 0, sizeof(*inverse
));
166 inverse
->src
.l3num
= orig
->src
.l3num
;
167 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
170 inverse
->dst
.dir
= !orig
->dst
.dir
;
172 inverse
->dst
.protonum
= orig
->dst
.protonum
;
173 return l4proto
->invert_tuple(inverse
, orig
);
175 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
178 clean_from_lists(struct nf_conn
*ct
)
180 pr_debug("clean_from_lists(%p)\n", ct
);
181 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
182 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
184 /* Destroy all pending expectations */
185 nf_ct_remove_expectations(ct
);
189 destroy_conntrack(struct nf_conntrack
*nfct
)
191 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
192 struct net
*net
= nf_ct_net(ct
);
193 struct nf_conntrack_l4proto
*l4proto
;
195 pr_debug("destroy_conntrack(%p)\n", ct
);
196 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
197 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
199 /* To make sure we don't get any weird locking issues here:
200 * destroy_conntrack() MUST NOT be called with a write lock
201 * to nf_conntrack_lock!!! -HW */
203 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
204 if (l4proto
&& l4proto
->destroy
)
205 l4proto
->destroy(ct
);
209 spin_lock_bh(&nf_conntrack_lock
);
210 /* Expectations will have been removed in clean_from_lists,
211 * except TFTP can create an expectation on the first packet,
212 * before connection is in the list, so we need to clean here,
214 nf_ct_remove_expectations(ct
);
216 /* We overload first tuple to link into unconfirmed list. */
217 if (!nf_ct_is_confirmed(ct
)) {
218 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
219 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
222 NF_CT_STAT_INC(net
, delete);
223 spin_unlock_bh(&nf_conntrack_lock
);
226 nf_ct_put(ct
->master
);
228 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
229 nf_conntrack_free(ct
);
232 void nf_ct_delete_from_lists(struct nf_conn
*ct
)
234 struct net
*net
= nf_ct_net(ct
);
236 nf_ct_helper_destroy(ct
);
237 spin_lock_bh(&nf_conntrack_lock
);
238 /* Inside lock so preempt is disabled on module removal path.
239 * Otherwise we can get spurious warnings. */
240 NF_CT_STAT_INC(net
, delete_list
);
241 clean_from_lists(ct
);
242 spin_unlock_bh(&nf_conntrack_lock
);
244 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists
);
246 static void death_by_event(unsigned long ul_conntrack
)
248 struct nf_conn
*ct
= (void *)ul_conntrack
;
249 struct net
*net
= nf_ct_net(ct
);
251 if (nf_conntrack_event(IPCT_DESTROY
, ct
) < 0) {
252 /* bad luck, let's retry again */
253 ct
->timeout
.expires
= jiffies
+
254 (random32() % net
->ct
.sysctl_events_retry_timeout
);
255 add_timer(&ct
->timeout
);
258 /* we've got the event delivered, now it's dying */
259 set_bit(IPS_DYING_BIT
, &ct
->status
);
260 spin_lock(&nf_conntrack_lock
);
261 hlist_nulls_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
262 spin_unlock(&nf_conntrack_lock
);
266 void nf_ct_insert_dying_list(struct nf_conn
*ct
)
268 struct net
*net
= nf_ct_net(ct
);
270 /* add this conntrack to the dying list */
271 spin_lock_bh(&nf_conntrack_lock
);
272 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
274 spin_unlock_bh(&nf_conntrack_lock
);
275 /* set a new timer to retry event delivery */
276 setup_timer(&ct
->timeout
, death_by_event
, (unsigned long)ct
);
277 ct
->timeout
.expires
= jiffies
+
278 (random32() % net
->ct
.sysctl_events_retry_timeout
);
279 add_timer(&ct
->timeout
);
281 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list
);
283 static void death_by_timeout(unsigned long ul_conntrack
)
285 struct nf_conn
*ct
= (void *)ul_conntrack
;
286 struct nf_conn_tstamp
*tstamp
;
288 tstamp
= nf_conn_tstamp_find(ct
);
289 if (tstamp
&& tstamp
->stop
== 0)
290 tstamp
->stop
= ktime_to_ns(ktime_get_real());
292 if (!test_bit(IPS_DYING_BIT
, &ct
->status
) &&
293 unlikely(nf_conntrack_event(IPCT_DESTROY
, ct
) < 0)) {
294 /* destroy event was not delivered */
295 nf_ct_delete_from_lists(ct
);
296 nf_ct_insert_dying_list(ct
);
299 set_bit(IPS_DYING_BIT
, &ct
->status
);
300 nf_ct_delete_from_lists(ct
);
306 * - Caller must take a reference on returned object
307 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
309 * - Caller must lock nf_conntrack_lock before calling this function
311 static struct nf_conntrack_tuple_hash
*
312 ____nf_conntrack_find(struct net
*net
, u16 zone
,
313 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
315 struct nf_conntrack_tuple_hash
*h
;
316 struct hlist_nulls_node
*n
;
317 unsigned int bucket
= hash_bucket(hash
, net
);
319 /* Disable BHs the entire time since we normally need to disable them
320 * at least once for the stats anyway.
324 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
325 if (nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
326 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)) == zone
) {
327 NF_CT_STAT_INC(net
, found
);
331 NF_CT_STAT_INC(net
, searched
);
334 * if the nulls value we got at the end of this lookup is
335 * not the expected one, we must restart lookup.
336 * We probably met an item that was moved to another chain.
338 if (get_nulls_value(n
) != bucket
) {
339 NF_CT_STAT_INC(net
, search_restart
);
347 struct nf_conntrack_tuple_hash
*
348 __nf_conntrack_find(struct net
*net
, u16 zone
,
349 const struct nf_conntrack_tuple
*tuple
)
351 return ____nf_conntrack_find(net
, zone
, tuple
,
352 hash_conntrack_raw(tuple
, zone
));
354 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
356 /* Find a connection corresponding to a tuple. */
357 static struct nf_conntrack_tuple_hash
*
358 __nf_conntrack_find_get(struct net
*net
, u16 zone
,
359 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
361 struct nf_conntrack_tuple_hash
*h
;
366 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
368 ct
= nf_ct_tuplehash_to_ctrack(h
);
369 if (unlikely(nf_ct_is_dying(ct
) ||
370 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
373 if (unlikely(!nf_ct_tuple_equal(tuple
, &h
->tuple
) ||
374 nf_ct_zone(ct
) != zone
)) {
385 struct nf_conntrack_tuple_hash
*
386 nf_conntrack_find_get(struct net
*net
, u16 zone
,
387 const struct nf_conntrack_tuple
*tuple
)
389 return __nf_conntrack_find_get(net
, zone
, tuple
,
390 hash_conntrack_raw(tuple
, zone
));
392 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
394 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
396 unsigned int repl_hash
)
398 struct net
*net
= nf_ct_net(ct
);
400 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
401 &net
->ct
.hash
[hash
]);
402 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
403 &net
->ct
.hash
[repl_hash
]);
406 void nf_conntrack_hash_insert(struct nf_conn
*ct
)
408 struct net
*net
= nf_ct_net(ct
);
409 unsigned int hash
, repl_hash
;
412 zone
= nf_ct_zone(ct
);
413 hash
= hash_conntrack(net
, zone
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
414 repl_hash
= hash_conntrack(net
, zone
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
416 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
418 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert
);
420 /* Confirm a connection given skb; places it in hash table */
422 __nf_conntrack_confirm(struct sk_buff
*skb
)
424 unsigned int hash
, repl_hash
;
425 struct nf_conntrack_tuple_hash
*h
;
427 struct nf_conn_help
*help
;
428 struct nf_conn_tstamp
*tstamp
;
429 struct hlist_nulls_node
*n
;
430 enum ip_conntrack_info ctinfo
;
434 ct
= nf_ct_get(skb
, &ctinfo
);
437 /* ipt_REJECT uses nf_conntrack_attach to attach related
438 ICMP/TCP RST packets in other direction. Actual packet
439 which created connection will be IP_CT_NEW or for an
440 expected connection, IP_CT_RELATED. */
441 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
444 zone
= nf_ct_zone(ct
);
445 /* reuse the hash saved before */
446 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
447 hash
= hash_bucket(hash
, net
);
448 repl_hash
= hash_conntrack(net
, zone
,
449 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
451 /* We're not in hash table, and we refuse to set up related
452 connections for unconfirmed conns. But packet copies and
453 REJECT will give spurious warnings here. */
454 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
456 /* No external references means no one else could have
458 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
459 pr_debug("Confirming conntrack %p\n", ct
);
461 spin_lock_bh(&nf_conntrack_lock
);
463 /* We have to check the DYING flag inside the lock to prevent
464 a race against nf_ct_get_next_corpse() possibly called from
465 user context, else we insert an already 'dead' hash, blocking
466 further use of that particular connection -JM */
468 if (unlikely(nf_ct_is_dying(ct
))) {
469 spin_unlock_bh(&nf_conntrack_lock
);
473 /* See if there's one in the list already, including reverse:
474 NAT could have grabbed it without realizing, since we're
475 not in the hash. If there is, we lost race. */
476 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
477 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
479 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
481 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[repl_hash
], hnnode
)
482 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
484 zone
== nf_ct_zone(nf_ct_tuplehash_to_ctrack(h
)))
487 /* Remove from unconfirmed list */
488 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
490 /* Timer relative to confirmation time, not original
491 setting time, otherwise we'd get timer wrap in
492 weird delay cases. */
493 ct
->timeout
.expires
+= jiffies
;
494 add_timer(&ct
->timeout
);
495 atomic_inc(&ct
->ct_general
.use
);
496 ct
->status
|= IPS_CONFIRMED
;
498 /* set conntrack timestamp, if enabled. */
499 tstamp
= nf_conn_tstamp_find(ct
);
501 if (skb
->tstamp
.tv64
== 0)
502 __net_timestamp((struct sk_buff
*)skb
);
504 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
506 /* Since the lookup is lockless, hash insertion must be done after
507 * starting the timer and setting the CONFIRMED bit. The RCU barriers
508 * guarantee that no other CPU can find the conntrack before the above
509 * stores are visible.
511 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
512 NF_CT_STAT_INC(net
, insert
);
513 spin_unlock_bh(&nf_conntrack_lock
);
515 help
= nfct_help(ct
);
516 if (help
&& help
->helper
)
517 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
519 nf_conntrack_event_cache(master_ct(ct
) ?
520 IPCT_RELATED
: IPCT_NEW
, ct
);
524 NF_CT_STAT_INC(net
, insert_failed
);
525 spin_unlock_bh(&nf_conntrack_lock
);
528 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
530 /* Returns true if a connection correspondings to the tuple (required
533 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
534 const struct nf_conn
*ignored_conntrack
)
536 struct net
*net
= nf_ct_net(ignored_conntrack
);
537 struct nf_conntrack_tuple_hash
*h
;
538 struct hlist_nulls_node
*n
;
540 u16 zone
= nf_ct_zone(ignored_conntrack
);
541 unsigned int hash
= hash_conntrack(net
, zone
, tuple
);
543 /* Disable BHs the entire time since we need to disable them at
544 * least once for the stats anyway.
547 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
548 ct
= nf_ct_tuplehash_to_ctrack(h
);
549 if (ct
!= ignored_conntrack
&&
550 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
551 nf_ct_zone(ct
) == zone
) {
552 NF_CT_STAT_INC(net
, found
);
553 rcu_read_unlock_bh();
556 NF_CT_STAT_INC(net
, searched
);
558 rcu_read_unlock_bh();
562 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
564 #define NF_CT_EVICTION_RANGE 8
566 /* There's a small race here where we may free a just-assured
567 connection. Too bad: we're in trouble anyway. */
568 static noinline
int early_drop(struct net
*net
, unsigned int hash
)
570 /* Use oldest entry, which is roughly LRU */
571 struct nf_conntrack_tuple_hash
*h
;
572 struct nf_conn
*ct
= NULL
, *tmp
;
573 struct hlist_nulls_node
*n
;
574 unsigned int i
, cnt
= 0;
578 for (i
= 0; i
< net
->ct
.htable_size
; i
++) {
579 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
581 tmp
= nf_ct_tuplehash_to_ctrack(h
);
582 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
))
588 if (likely(!nf_ct_is_dying(ct
) &&
589 atomic_inc_not_zero(&ct
->ct_general
.use
)))
595 if (cnt
>= NF_CT_EVICTION_RANGE
)
598 hash
= (hash
+ 1) % net
->ct
.htable_size
;
605 if (del_timer(&ct
->timeout
)) {
606 death_by_timeout((unsigned long)ct
);
608 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
614 void init_nf_conntrack_hash_rnd(void)
619 * Why not initialize nf_conntrack_rnd in a "init()" function ?
620 * Because there isn't enough entropy when system initializing,
621 * and we initialize it as late as possible.
624 get_random_bytes(&rand
, sizeof(rand
));
626 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
629 static struct nf_conn
*
630 __nf_conntrack_alloc(struct net
*net
, u16 zone
,
631 const struct nf_conntrack_tuple
*orig
,
632 const struct nf_conntrack_tuple
*repl
,
637 if (unlikely(!nf_conntrack_hash_rnd
)) {
638 init_nf_conntrack_hash_rnd();
639 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
640 hash
= hash_conntrack_raw(orig
, zone
);
643 /* We don't want any race condition at early drop stage */
644 atomic_inc(&net
->ct
.count
);
646 if (nf_conntrack_max
&&
647 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
648 if (!early_drop(net
, hash_bucket(hash
, net
))) {
649 atomic_dec(&net
->ct
.count
);
652 "nf_conntrack: table full, dropping"
654 return ERR_PTR(-ENOMEM
);
659 * Do not use kmem_cache_zalloc(), as this cache uses
660 * SLAB_DESTROY_BY_RCU.
662 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
664 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
665 atomic_dec(&net
->ct
.count
);
666 return ERR_PTR(-ENOMEM
);
669 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
670 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
672 memset(&ct
->tuplehash
[IP_CT_DIR_MAX
], 0,
673 offsetof(struct nf_conn
, proto
) -
674 offsetof(struct nf_conn
, tuplehash
[IP_CT_DIR_MAX
]));
675 spin_lock_init(&ct
->lock
);
676 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
677 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
678 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
679 /* save hash for reusing when confirming */
680 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
681 /* Don't set timer yet: wait for confirmation */
682 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
683 write_pnet(&ct
->ct_net
, net
);
684 #ifdef CONFIG_NF_CONNTRACK_ZONES
686 struct nf_conntrack_zone
*nf_ct_zone
;
688 nf_ct_zone
= nf_ct_ext_add(ct
, NF_CT_EXT_ZONE
, GFP_ATOMIC
);
691 nf_ct_zone
->id
= zone
;
695 * changes to lookup keys must be done before setting refcnt to 1
698 atomic_set(&ct
->ct_general
.use
, 1);
701 #ifdef CONFIG_NF_CONNTRACK_ZONES
703 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
704 return ERR_PTR(-ENOMEM
);
708 struct nf_conn
*nf_conntrack_alloc(struct net
*net
, u16 zone
,
709 const struct nf_conntrack_tuple
*orig
,
710 const struct nf_conntrack_tuple
*repl
,
713 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
715 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
717 void nf_conntrack_free(struct nf_conn
*ct
)
719 struct net
*net
= nf_ct_net(ct
);
721 nf_ct_ext_destroy(ct
);
722 atomic_dec(&net
->ct
.count
);
724 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
726 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
728 /* Allocate a new conntrack: we return -ENOMEM if classification
729 failed due to stress. Otherwise it really is unclassifiable. */
730 static struct nf_conntrack_tuple_hash
*
731 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
732 const struct nf_conntrack_tuple
*tuple
,
733 struct nf_conntrack_l3proto
*l3proto
,
734 struct nf_conntrack_l4proto
*l4proto
,
736 unsigned int dataoff
, u32 hash
)
739 struct nf_conn_help
*help
;
740 struct nf_conntrack_tuple repl_tuple
;
741 struct nf_conntrack_ecache
*ecache
;
742 struct nf_conntrack_expect
*exp
;
743 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
745 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
746 pr_debug("Can't invert tuple.\n");
750 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
753 pr_debug("Can't allocate conntrack.\n");
754 return (struct nf_conntrack_tuple_hash
*)ct
;
757 if (!l4proto
->new(ct
, skb
, dataoff
)) {
758 nf_conntrack_free(ct
);
759 pr_debug("init conntrack: can't track with proto module\n");
763 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
764 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
766 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
767 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
768 ecache
? ecache
->expmask
: 0,
771 spin_lock_bh(&nf_conntrack_lock
);
772 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
774 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
776 /* Welcome, Mr. Bond. We've been expecting you... */
777 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
778 ct
->master
= exp
->master
;
780 help
= nf_ct_helper_ext_add(ct
, GFP_ATOMIC
);
782 rcu_assign_pointer(help
->helper
, exp
->helper
);
785 #ifdef CONFIG_NF_CONNTRACK_MARK
786 ct
->mark
= exp
->master
->mark
;
788 #ifdef CONFIG_NF_CONNTRACK_SECMARK
789 ct
->secmark
= exp
->master
->secmark
;
791 nf_conntrack_get(&ct
->master
->ct_general
);
792 NF_CT_STAT_INC(net
, expect_new
);
794 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
795 NF_CT_STAT_INC(net
, new);
798 /* Overload tuple linked list to put us in unconfirmed list. */
799 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
800 &net
->ct
.unconfirmed
);
802 spin_unlock_bh(&nf_conntrack_lock
);
806 exp
->expectfn(ct
, exp
);
807 nf_ct_expect_put(exp
);
810 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
813 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
814 static inline struct nf_conn
*
815 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
817 unsigned int dataoff
,
820 struct nf_conntrack_l3proto
*l3proto
,
821 struct nf_conntrack_l4proto
*l4proto
,
823 enum ip_conntrack_info
*ctinfo
)
825 struct nf_conntrack_tuple tuple
;
826 struct nf_conntrack_tuple_hash
*h
;
828 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
831 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
832 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
834 pr_debug("resolve_normal_ct: Can't get tuple\n");
838 /* look for tuple match */
839 hash
= hash_conntrack_raw(&tuple
, zone
);
840 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
842 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
849 ct
= nf_ct_tuplehash_to_ctrack(h
);
851 /* It exists; we have (non-exclusive) reference. */
852 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
853 *ctinfo
= IP_CT_ESTABLISHED
+ IP_CT_IS_REPLY
;
854 /* Please set reply bit if this packet OK */
857 /* Once we've had two way comms, always ESTABLISHED. */
858 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
859 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
860 *ctinfo
= IP_CT_ESTABLISHED
;
861 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
862 pr_debug("nf_conntrack_in: related packet for %p\n",
864 *ctinfo
= IP_CT_RELATED
;
866 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
871 skb
->nfct
= &ct
->ct_general
;
872 skb
->nfctinfo
= *ctinfo
;
877 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
880 struct nf_conn
*ct
, *tmpl
= NULL
;
881 enum ip_conntrack_info ctinfo
;
882 struct nf_conntrack_l3proto
*l3proto
;
883 struct nf_conntrack_l4proto
*l4proto
;
884 unsigned int dataoff
;
890 /* Previously seen (loopback or untracked)? Ignore. */
891 tmpl
= (struct nf_conn
*)skb
->nfct
;
892 if (!nf_ct_is_template(tmpl
)) {
893 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
899 /* rcu_read_lock()ed by nf_hook_slow */
900 l3proto
= __nf_ct_l3proto_find(pf
);
901 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
902 &dataoff
, &protonum
);
904 pr_debug("not prepared to track yet or error occurred\n");
905 NF_CT_STAT_INC_ATOMIC(net
, error
);
906 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
911 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
913 /* It may be an special packet, error, unclean...
914 * inverse of the return code tells to the netfilter
915 * core what to do with the packet. */
916 if (l4proto
->error
!= NULL
) {
917 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
920 NF_CT_STAT_INC_ATOMIC(net
, error
);
921 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
927 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
928 l3proto
, l4proto
, &set_reply
, &ctinfo
);
930 /* Not valid part of a connection */
931 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
937 /* Too stressed to deal. */
938 NF_CT_STAT_INC_ATOMIC(net
, drop
);
943 NF_CT_ASSERT(skb
->nfct
);
945 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
);
947 /* Invalid: inverse of the return code tells
948 * the netfilter core what to do */
949 pr_debug("nf_conntrack_in: Can't track with proto module\n");
950 nf_conntrack_put(skb
->nfct
);
952 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
954 NF_CT_STAT_INC_ATOMIC(net
, drop
);
959 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
960 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
963 /* Special case: we have to repeat this hook, assign the
964 * template again to this packet. We assume that this packet
965 * has no conntrack assigned. This is used by nf_ct_tcp. */
966 if (ret
== NF_REPEAT
)
967 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
974 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
976 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
977 const struct nf_conntrack_tuple
*orig
)
982 ret
= nf_ct_invert_tuple(inverse
, orig
,
983 __nf_ct_l3proto_find(orig
->src
.l3num
),
984 __nf_ct_l4proto_find(orig
->src
.l3num
,
985 orig
->dst
.protonum
));
989 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
991 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
992 implicitly racy: see __nf_conntrack_confirm */
993 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
994 const struct nf_conntrack_tuple
*newreply
)
996 struct nf_conn_help
*help
= nfct_help(ct
);
998 /* Should be unconfirmed, so not in hash table yet */
999 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1001 pr_debug("Altering reply tuple of %p to ", ct
);
1002 nf_ct_dump_tuple(newreply
);
1004 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1005 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1009 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1012 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1014 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1015 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1016 enum ip_conntrack_info ctinfo
,
1017 const struct sk_buff
*skb
,
1018 unsigned long extra_jiffies
,
1021 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1024 /* Only update if this is not a fixed timeout */
1025 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1028 /* If not in hash table, timer will not be active yet */
1029 if (!nf_ct_is_confirmed(ct
)) {
1030 ct
->timeout
.expires
= extra_jiffies
;
1032 unsigned long newtime
= jiffies
+ extra_jiffies
;
1034 /* Only update the timeout if the new timeout is at least
1035 HZ jiffies from the old timeout. Need del_timer for race
1036 avoidance (may already be dying). */
1037 if (newtime
- ct
->timeout
.expires
>= HZ
)
1038 mod_timer_pending(&ct
->timeout
, newtime
);
1043 struct nf_conn_counter
*acct
;
1045 acct
= nf_conn_acct_find(ct
);
1047 spin_lock_bh(&ct
->lock
);
1048 acct
[CTINFO2DIR(ctinfo
)].packets
++;
1049 acct
[CTINFO2DIR(ctinfo
)].bytes
+= skb
->len
;
1050 spin_unlock_bh(&ct
->lock
);
1054 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1056 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1057 enum ip_conntrack_info ctinfo
,
1058 const struct sk_buff
*skb
,
1062 struct nf_conn_counter
*acct
;
1064 acct
= nf_conn_acct_find(ct
);
1066 spin_lock_bh(&ct
->lock
);
1067 acct
[CTINFO2DIR(ctinfo
)].packets
++;
1068 acct
[CTINFO2DIR(ctinfo
)].bytes
+=
1069 skb
->len
- skb_network_offset(skb
);
1070 spin_unlock_bh(&ct
->lock
);
1074 if (del_timer(&ct
->timeout
)) {
1075 ct
->timeout
.function((unsigned long)ct
);
1080 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1082 #ifdef CONFIG_NF_CONNTRACK_ZONES
1083 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1084 .len
= sizeof(struct nf_conntrack_zone
),
1085 .align
= __alignof__(struct nf_conntrack_zone
),
1086 .id
= NF_CT_EXT_ZONE
,
1090 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1092 #include <linux/netfilter/nfnetlink.h>
1093 #include <linux/netfilter/nfnetlink_conntrack.h>
1094 #include <linux/mutex.h>
1096 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1097 * in ip_conntrack_core, since we don't want the protocols to autoload
1098 * or depend on ctnetlink */
1099 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1100 const struct nf_conntrack_tuple
*tuple
)
1102 NLA_PUT_BE16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
);
1103 NLA_PUT_BE16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
);
1109 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1111 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1112 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1113 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1115 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1117 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1118 struct nf_conntrack_tuple
*t
)
1120 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1123 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1124 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1128 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1130 int nf_ct_port_nlattr_tuple_size(void)
1132 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1134 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1137 /* Used by ipt_REJECT and ip6t_REJECT. */
1138 static void nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
1141 enum ip_conntrack_info ctinfo
;
1143 /* This ICMP is in reverse direction to the packet which caused it */
1144 ct
= nf_ct_get(skb
, &ctinfo
);
1145 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1146 ctinfo
= IP_CT_RELATED
+ IP_CT_IS_REPLY
;
1148 ctinfo
= IP_CT_RELATED
;
1150 /* Attach to new skbuff, and increment count */
1151 nskb
->nfct
= &ct
->ct_general
;
1152 nskb
->nfctinfo
= ctinfo
;
1153 nf_conntrack_get(nskb
->nfct
);
1156 /* Bring out ya dead! */
1157 static struct nf_conn
*
1158 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1159 void *data
, unsigned int *bucket
)
1161 struct nf_conntrack_tuple_hash
*h
;
1163 struct hlist_nulls_node
*n
;
1165 spin_lock_bh(&nf_conntrack_lock
);
1166 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1167 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1168 ct
= nf_ct_tuplehash_to_ctrack(h
);
1173 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.unconfirmed
, hnnode
) {
1174 ct
= nf_ct_tuplehash_to_ctrack(h
);
1176 set_bit(IPS_DYING_BIT
, &ct
->status
);
1178 spin_unlock_bh(&nf_conntrack_lock
);
1181 atomic_inc(&ct
->ct_general
.use
);
1182 spin_unlock_bh(&nf_conntrack_lock
);
1186 void nf_ct_iterate_cleanup(struct net
*net
,
1187 int (*iter
)(struct nf_conn
*i
, void *data
),
1191 unsigned int bucket
= 0;
1193 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1194 /* Time to push up daises... */
1195 if (del_timer(&ct
->timeout
))
1196 death_by_timeout((unsigned long)ct
);
1197 /* ... else the timer will get him soon. */
1202 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1204 struct __nf_ct_flush_report
{
1209 static int kill_report(struct nf_conn
*i
, void *data
)
1211 struct __nf_ct_flush_report
*fr
= (struct __nf_ct_flush_report
*)data
;
1212 struct nf_conn_tstamp
*tstamp
;
1214 tstamp
= nf_conn_tstamp_find(i
);
1215 if (tstamp
&& tstamp
->stop
== 0)
1216 tstamp
->stop
= ktime_to_ns(ktime_get_real());
1218 /* If we fail to deliver the event, death_by_timeout() will retry */
1219 if (nf_conntrack_event_report(IPCT_DESTROY
, i
,
1220 fr
->pid
, fr
->report
) < 0)
1223 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1224 set_bit(IPS_DYING_BIT
, &i
->status
);
1228 static int kill_all(struct nf_conn
*i
, void *data
)
1233 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1235 if (is_vmalloc_addr(hash
))
1238 free_pages((unsigned long)hash
,
1239 get_order(sizeof(struct hlist_head
) * size
));
1241 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1243 void nf_conntrack_flush_report(struct net
*net
, u32 pid
, int report
)
1245 struct __nf_ct_flush_report fr
= {
1249 nf_ct_iterate_cleanup(net
, kill_report
, &fr
);
1251 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report
);
1253 static void nf_ct_release_dying_list(struct net
*net
)
1255 struct nf_conntrack_tuple_hash
*h
;
1257 struct hlist_nulls_node
*n
;
1259 spin_lock_bh(&nf_conntrack_lock
);
1260 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.dying
, hnnode
) {
1261 ct
= nf_ct_tuplehash_to_ctrack(h
);
1262 /* never fails to remove them, no listeners at this point */
1265 spin_unlock_bh(&nf_conntrack_lock
);
1268 static int untrack_refs(void)
1272 for_each_possible_cpu(cpu
) {
1273 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1275 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1280 static void nf_conntrack_cleanup_init_net(void)
1282 while (untrack_refs() > 0)
1285 nf_conntrack_helper_fini();
1286 nf_conntrack_proto_fini();
1287 #ifdef CONFIG_NF_CONNTRACK_ZONES
1288 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1292 static void nf_conntrack_cleanup_net(struct net
*net
)
1295 nf_ct_iterate_cleanup(net
, kill_all
, NULL
);
1296 nf_ct_release_dying_list(net
);
1297 if (atomic_read(&net
->ct
.count
) != 0) {
1299 goto i_see_dead_people
;
1302 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1303 nf_conntrack_ecache_fini(net
);
1304 nf_conntrack_tstamp_fini(net
);
1305 nf_conntrack_acct_fini(net
);
1306 nf_conntrack_expect_fini(net
);
1307 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1308 kfree(net
->ct
.slabname
);
1309 free_percpu(net
->ct
.stat
);
1312 /* Mishearing the voices in his head, our hero wonders how he's
1313 supposed to kill the mall. */
1314 void nf_conntrack_cleanup(struct net
*net
)
1316 if (net_eq(net
, &init_net
))
1317 rcu_assign_pointer(ip_ct_attach
, NULL
);
1319 /* This makes sure all current packets have passed through
1320 netfilter framework. Roll on, two-stage module
1324 nf_conntrack_cleanup_net(net
);
1326 if (net_eq(net
, &init_net
)) {
1327 rcu_assign_pointer(nf_ct_destroy
, NULL
);
1328 nf_conntrack_cleanup_init_net();
1332 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1334 struct hlist_nulls_head
*hash
;
1335 unsigned int nr_slots
, i
;
1338 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1339 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1340 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1341 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1344 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1345 hash
= __vmalloc(sz
, GFP_KERNEL
| __GFP_HIGHMEM
| __GFP_ZERO
,
1350 for (i
= 0; i
< nr_slots
; i
++)
1351 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1355 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1357 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1360 unsigned int hashsize
, old_size
;
1361 struct hlist_nulls_head
*hash
, *old_hash
;
1362 struct nf_conntrack_tuple_hash
*h
;
1365 if (current
->nsproxy
->net_ns
!= &init_net
)
1368 /* On boot, we can set this without any fancy locking. */
1369 if (!nf_conntrack_htable_size
)
1370 return param_set_uint(val
, kp
);
1372 hashsize
= simple_strtoul(val
, NULL
, 0);
1376 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1380 /* Lookups in the old hash might happen in parallel, which means we
1381 * might get false negatives during connection lookup. New connections
1382 * created because of a false negative won't make it into the hash
1383 * though since that required taking the lock.
1385 spin_lock_bh(&nf_conntrack_lock
);
1386 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1387 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1388 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1389 struct nf_conntrack_tuple_hash
, hnnode
);
1390 ct
= nf_ct_tuplehash_to_ctrack(h
);
1391 hlist_nulls_del_rcu(&h
->hnnode
);
1392 bucket
= __hash_conntrack(&h
->tuple
, nf_ct_zone(ct
),
1394 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1397 old_size
= init_net
.ct
.htable_size
;
1398 old_hash
= init_net
.ct
.hash
;
1400 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1401 init_net
.ct
.hash
= hash
;
1402 spin_unlock_bh(&nf_conntrack_lock
);
1404 nf_ct_free_hashtable(old_hash
, old_size
);
1407 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1409 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1410 &nf_conntrack_htable_size
, 0600);
1412 void nf_ct_untracked_status_or(unsigned long bits
)
1416 for_each_possible_cpu(cpu
)
1417 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1419 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1421 static int nf_conntrack_init_init_net(void)
1426 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1427 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1428 if (!nf_conntrack_htable_size
) {
1429 nf_conntrack_htable_size
1430 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1431 / sizeof(struct hlist_head
));
1432 if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1433 nf_conntrack_htable_size
= 16384;
1434 if (nf_conntrack_htable_size
< 32)
1435 nf_conntrack_htable_size
= 32;
1437 /* Use a max. factor of four by default to get the same max as
1438 * with the old struct list_heads. When a table size is given
1439 * we use the old value of 8 to avoid reducing the max.
1443 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1445 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1446 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1449 ret
= nf_conntrack_proto_init();
1453 ret
= nf_conntrack_helper_init();
1457 #ifdef CONFIG_NF_CONNTRACK_ZONES
1458 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1462 /* Set up fake conntrack: to never be deleted, not in any hashes */
1463 for_each_possible_cpu(cpu
) {
1464 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1465 write_pnet(&ct
->ct_net
, &init_net
);
1466 atomic_set(&ct
->ct_general
.use
, 1);
1468 /* - and look it like as a confirmed connection */
1469 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1472 #ifdef CONFIG_NF_CONNTRACK_ZONES
1474 nf_conntrack_helper_fini();
1477 nf_conntrack_proto_fini();
1483 * We need to use special "null" values, not used in hash table
1485 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1486 #define DYING_NULLS_VAL ((1<<30)+1)
1488 static int nf_conntrack_init_net(struct net
*net
)
1492 atomic_set(&net
->ct
.count
, 0);
1493 INIT_HLIST_NULLS_HEAD(&net
->ct
.unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1494 INIT_HLIST_NULLS_HEAD(&net
->ct
.dying
, DYING_NULLS_VAL
);
1495 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1496 if (!net
->ct
.stat
) {
1501 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1502 if (!net
->ct
.slabname
) {
1507 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1508 sizeof(struct nf_conn
), 0,
1509 SLAB_DESTROY_BY_RCU
, NULL
);
1510 if (!net
->ct
.nf_conntrack_cachep
) {
1511 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1516 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1517 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1518 if (!net
->ct
.hash
) {
1520 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1523 ret
= nf_conntrack_expect_init(net
);
1526 ret
= nf_conntrack_acct_init(net
);
1529 ret
= nf_conntrack_tstamp_init(net
);
1532 ret
= nf_conntrack_ecache_init(net
);
1539 nf_conntrack_tstamp_fini(net
);
1541 nf_conntrack_acct_fini(net
);
1543 nf_conntrack_expect_fini(net
);
1545 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1547 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1549 kfree(net
->ct
.slabname
);
1551 free_percpu(net
->ct
.stat
);
1556 s16 (*nf_ct_nat_offset
)(const struct nf_conn
*ct
,
1557 enum ip_conntrack_dir dir
,
1559 EXPORT_SYMBOL_GPL(nf_ct_nat_offset
);
1561 int nf_conntrack_init(struct net
*net
)
1565 if (net_eq(net
, &init_net
)) {
1566 ret
= nf_conntrack_init_init_net();
1570 ret
= nf_conntrack_init_net(net
);
1574 if (net_eq(net
, &init_net
)) {
1575 /* For use by REJECT target */
1576 rcu_assign_pointer(ip_ct_attach
, nf_conntrack_attach
);
1577 rcu_assign_pointer(nf_ct_destroy
, destroy_conntrack
);
1579 /* Howto get NAT offsets */
1580 rcu_assign_pointer(nf_ct_nat_offset
, NULL
);
1585 if (net_eq(net
, &init_net
))
1586 nf_conntrack_cleanup_init_net();