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 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks
[CONNTRACK_LOCKS
];
64 EXPORT_SYMBOL_GPL(nf_conntrack_locks
);
66 __cacheline_aligned_in_smp
DEFINE_SPINLOCK(nf_conntrack_expect_lock
);
67 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock
);
69 static void nf_conntrack_double_unlock(unsigned int h1
, unsigned int h2
)
71 h1
%= CONNTRACK_LOCKS
;
72 h2
%= CONNTRACK_LOCKS
;
73 spin_unlock(&nf_conntrack_locks
[h1
]);
75 spin_unlock(&nf_conntrack_locks
[h2
]);
78 /* return true if we need to recompute hashes (in case hash table was resized) */
79 static bool nf_conntrack_double_lock(struct net
*net
, unsigned int h1
,
80 unsigned int h2
, unsigned int sequence
)
82 h1
%= CONNTRACK_LOCKS
;
83 h2
%= CONNTRACK_LOCKS
;
85 spin_lock(&nf_conntrack_locks
[h1
]);
87 spin_lock_nested(&nf_conntrack_locks
[h2
],
88 SINGLE_DEPTH_NESTING
);
90 spin_lock(&nf_conntrack_locks
[h2
]);
91 spin_lock_nested(&nf_conntrack_locks
[h1
],
92 SINGLE_DEPTH_NESTING
);
94 if (read_seqcount_retry(&net
->ct
.generation
, sequence
)) {
95 nf_conntrack_double_unlock(h1
, h2
);
101 static void nf_conntrack_all_lock(void)
105 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
106 spin_lock_nested(&nf_conntrack_locks
[i
], i
);
109 static void nf_conntrack_all_unlock(void)
113 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
114 spin_unlock(&nf_conntrack_locks
[i
]);
117 unsigned int nf_conntrack_htable_size __read_mostly
;
118 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
120 unsigned int nf_conntrack_max __read_mostly
;
121 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
123 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
124 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
126 unsigned int nf_conntrack_hash_rnd __read_mostly
;
127 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd
);
129 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
)
133 /* The direction must be ignored, so we hash everything up to the
134 * destination ports (which is a multiple of 4) and treat the last
135 * three bytes manually.
137 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
138 return jhash2((u32
*)tuple
, n
, nf_conntrack_hash_rnd
^
139 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
140 tuple
->dst
.protonum
));
143 static u32
__hash_bucket(u32 hash
, unsigned int size
)
145 return reciprocal_scale(hash
, size
);
148 static u32
hash_bucket(u32 hash
, const struct net
*net
)
150 return __hash_bucket(hash
, net
->ct
.htable_size
);
153 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
156 return __hash_bucket(hash_conntrack_raw(tuple
), size
);
159 static inline u_int32_t
hash_conntrack(const struct net
*net
,
160 const struct nf_conntrack_tuple
*tuple
)
162 return __hash_conntrack(tuple
, net
->ct
.htable_size
);
166 nf_ct_get_tuple(const struct sk_buff
*skb
,
168 unsigned int dataoff
,
171 struct nf_conntrack_tuple
*tuple
,
172 const struct nf_conntrack_l3proto
*l3proto
,
173 const struct nf_conntrack_l4proto
*l4proto
)
175 memset(tuple
, 0, sizeof(*tuple
));
177 tuple
->src
.l3num
= l3num
;
178 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
181 tuple
->dst
.protonum
= protonum
;
182 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
184 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
186 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
188 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
189 u_int16_t l3num
, struct nf_conntrack_tuple
*tuple
)
191 struct nf_conntrack_l3proto
*l3proto
;
192 struct nf_conntrack_l4proto
*l4proto
;
193 unsigned int protoff
;
199 l3proto
= __nf_ct_l3proto_find(l3num
);
200 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
201 if (ret
!= NF_ACCEPT
) {
206 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
208 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, tuple
,
214 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
217 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
218 const struct nf_conntrack_tuple
*orig
,
219 const struct nf_conntrack_l3proto
*l3proto
,
220 const struct nf_conntrack_l4proto
*l4proto
)
222 memset(inverse
, 0, sizeof(*inverse
));
224 inverse
->src
.l3num
= orig
->src
.l3num
;
225 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
228 inverse
->dst
.dir
= !orig
->dst
.dir
;
230 inverse
->dst
.protonum
= orig
->dst
.protonum
;
231 return l4proto
->invert_tuple(inverse
, orig
);
233 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
236 clean_from_lists(struct nf_conn
*ct
)
238 pr_debug("clean_from_lists(%p)\n", ct
);
239 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
240 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
242 /* Destroy all pending expectations */
243 nf_ct_remove_expectations(ct
);
246 /* must be called with local_bh_disable */
247 static void nf_ct_add_to_dying_list(struct nf_conn
*ct
)
249 struct ct_pcpu
*pcpu
;
251 /* add this conntrack to the (per cpu) dying list */
252 ct
->cpu
= smp_processor_id();
253 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
255 spin_lock(&pcpu
->lock
);
256 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
258 spin_unlock(&pcpu
->lock
);
261 /* must be called with local_bh_disable */
262 static void nf_ct_add_to_unconfirmed_list(struct nf_conn
*ct
)
264 struct ct_pcpu
*pcpu
;
266 /* add this conntrack to the (per cpu) unconfirmed list */
267 ct
->cpu
= smp_processor_id();
268 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
270 spin_lock(&pcpu
->lock
);
271 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
273 spin_unlock(&pcpu
->lock
);
276 /* must be called with local_bh_disable */
277 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn
*ct
)
279 struct ct_pcpu
*pcpu
;
281 /* We overload first tuple to link into unconfirmed or dying list.*/
282 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
284 spin_lock(&pcpu
->lock
);
285 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
286 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
287 spin_unlock(&pcpu
->lock
);
290 /* Released via destroy_conntrack() */
291 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
292 const struct nf_conntrack_zone
*zone
,
295 struct nf_conn
*tmpl
;
297 tmpl
= kzalloc(sizeof(struct nf_conn
), GFP_KERNEL
);
301 tmpl
->status
= IPS_TEMPLATE
;
302 write_pnet(&tmpl
->ct_net
, net
);
304 if (nf_ct_zone_add(tmpl
, flags
, zone
) < 0)
307 atomic_set(&tmpl
->ct_general
.use
, 0);
314 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc
);
316 static void nf_ct_tmpl_free(struct nf_conn
*tmpl
)
318 nf_ct_ext_destroy(tmpl
);
319 nf_ct_ext_free(tmpl
);
324 destroy_conntrack(struct nf_conntrack
*nfct
)
326 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
327 struct net
*net
= nf_ct_net(ct
);
328 struct nf_conntrack_l4proto
*l4proto
;
330 pr_debug("destroy_conntrack(%p)\n", ct
);
331 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
332 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
334 if (unlikely(nf_ct_is_template(ct
))) {
339 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
340 if (l4proto
&& l4proto
->destroy
)
341 l4proto
->destroy(ct
);
346 /* Expectations will have been removed in clean_from_lists,
347 * except TFTP can create an expectation on the first packet,
348 * before connection is in the list, so we need to clean here,
351 nf_ct_remove_expectations(ct
);
353 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
355 NF_CT_STAT_INC(net
, delete);
359 nf_ct_put(ct
->master
);
361 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
362 nf_conntrack_free(ct
);
365 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
367 struct net
*net
= nf_ct_net(ct
);
368 unsigned int hash
, reply_hash
;
369 unsigned int sequence
;
371 nf_ct_helper_destroy(ct
);
375 sequence
= read_seqcount_begin(&net
->ct
.generation
);
376 hash
= hash_conntrack(net
,
377 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
378 reply_hash
= hash_conntrack(net
,
379 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
380 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
382 clean_from_lists(ct
);
383 nf_conntrack_double_unlock(hash
, reply_hash
);
385 nf_ct_add_to_dying_list(ct
);
387 NF_CT_STAT_INC(net
, delete_list
);
391 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
393 struct nf_conn_tstamp
*tstamp
;
395 tstamp
= nf_conn_tstamp_find(ct
);
396 if (tstamp
&& tstamp
->stop
== 0)
397 tstamp
->stop
= ktime_get_real_ns();
399 if (nf_ct_is_dying(ct
))
402 if (nf_conntrack_event_report(IPCT_DESTROY
, ct
,
403 portid
, report
) < 0) {
404 /* destroy event was not delivered */
405 nf_ct_delete_from_lists(ct
);
406 nf_conntrack_ecache_delayed_work(nf_ct_net(ct
));
410 nf_conntrack_ecache_work(nf_ct_net(ct
));
411 set_bit(IPS_DYING_BIT
, &ct
->status
);
413 nf_ct_delete_from_lists(ct
);
417 EXPORT_SYMBOL_GPL(nf_ct_delete
);
419 static void death_by_timeout(unsigned long ul_conntrack
)
421 nf_ct_delete((struct nf_conn
*)ul_conntrack
, 0, 0);
425 nf_ct_key_equal(struct nf_conntrack_tuple_hash
*h
,
426 const struct nf_conntrack_tuple
*tuple
,
427 const struct nf_conntrack_zone
*zone
)
429 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
431 /* A conntrack can be recreated with the equal tuple,
432 * so we need to check that the conntrack is confirmed
434 return nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
435 nf_ct_zone_equal(ct
, zone
, NF_CT_DIRECTION(h
)) &&
436 nf_ct_is_confirmed(ct
);
441 * - Caller must take a reference on returned object
442 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
444 static struct nf_conntrack_tuple_hash
*
445 ____nf_conntrack_find(struct net
*net
, const struct nf_conntrack_zone
*zone
,
446 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
448 struct nf_conntrack_tuple_hash
*h
;
449 struct hlist_nulls_node
*n
;
450 unsigned int bucket
= hash_bucket(hash
, net
);
452 /* Disable BHs the entire time since we normally need to disable them
453 * at least once for the stats anyway.
457 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[bucket
], hnnode
) {
458 if (nf_ct_key_equal(h
, tuple
, zone
)) {
459 NF_CT_STAT_INC(net
, found
);
463 NF_CT_STAT_INC(net
, searched
);
466 * if the nulls value we got at the end of this lookup is
467 * not the expected one, we must restart lookup.
468 * We probably met an item that was moved to another chain.
470 if (get_nulls_value(n
) != bucket
) {
471 NF_CT_STAT_INC(net
, search_restart
);
479 /* Find a connection corresponding to a tuple. */
480 static struct nf_conntrack_tuple_hash
*
481 __nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
482 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
484 struct nf_conntrack_tuple_hash
*h
;
489 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
491 ct
= nf_ct_tuplehash_to_ctrack(h
);
492 if (unlikely(nf_ct_is_dying(ct
) ||
493 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
496 if (unlikely(!nf_ct_key_equal(h
, tuple
, zone
))) {
507 struct nf_conntrack_tuple_hash
*
508 nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
509 const struct nf_conntrack_tuple
*tuple
)
511 return __nf_conntrack_find_get(net
, zone
, tuple
,
512 hash_conntrack_raw(tuple
));
514 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
516 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
518 unsigned int reply_hash
)
520 struct net
*net
= nf_ct_net(ct
);
522 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
523 &net
->ct
.hash
[hash
]);
524 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
525 &net
->ct
.hash
[reply_hash
]);
529 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
531 const struct nf_conntrack_zone
*zone
;
532 struct net
*net
= nf_ct_net(ct
);
533 unsigned int hash
, reply_hash
;
534 struct nf_conntrack_tuple_hash
*h
;
535 struct hlist_nulls_node
*n
;
536 unsigned int sequence
;
538 zone
= nf_ct_zone(ct
);
542 sequence
= read_seqcount_begin(&net
->ct
.generation
);
543 hash
= hash_conntrack(net
,
544 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
545 reply_hash
= hash_conntrack(net
,
546 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
547 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
549 /* See if there's one in the list already, including reverse */
550 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
551 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
553 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h
), zone
,
556 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[reply_hash
], hnnode
)
557 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
559 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h
), zone
,
563 add_timer(&ct
->timeout
);
565 /* The caller holds a reference to this object */
566 atomic_set(&ct
->ct_general
.use
, 2);
567 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
568 nf_conntrack_double_unlock(hash
, reply_hash
);
569 NF_CT_STAT_INC(net
, insert
);
574 nf_conntrack_double_unlock(hash
, reply_hash
);
575 NF_CT_STAT_INC(net
, insert_failed
);
579 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
581 /* Confirm a connection given skb; places it in hash table */
583 __nf_conntrack_confirm(struct sk_buff
*skb
)
585 const struct nf_conntrack_zone
*zone
;
586 unsigned int hash
, reply_hash
;
587 struct nf_conntrack_tuple_hash
*h
;
589 struct nf_conn_help
*help
;
590 struct nf_conn_tstamp
*tstamp
;
591 struct hlist_nulls_node
*n
;
592 enum ip_conntrack_info ctinfo
;
594 unsigned int sequence
;
596 ct
= nf_ct_get(skb
, &ctinfo
);
599 /* ipt_REJECT uses nf_conntrack_attach to attach related
600 ICMP/TCP RST packets in other direction. Actual packet
601 which created connection will be IP_CT_NEW or for an
602 expected connection, IP_CT_RELATED. */
603 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
606 zone
= nf_ct_zone(ct
);
610 sequence
= read_seqcount_begin(&net
->ct
.generation
);
611 /* reuse the hash saved before */
612 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
613 hash
= hash_bucket(hash
, net
);
614 reply_hash
= hash_conntrack(net
,
615 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
617 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
619 /* We're not in hash table, and we refuse to set up related
620 * connections for unconfirmed conns. But packet copies and
621 * REJECT will give spurious warnings here.
623 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
625 /* No external references means no one else could have
628 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
629 pr_debug("Confirming conntrack %p\n", ct
);
630 /* We have to check the DYING flag after unlink to prevent
631 * a race against nf_ct_get_next_corpse() possibly called from
632 * user context, else we insert an already 'dead' hash, blocking
633 * further use of that particular connection -JM.
635 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
637 if (unlikely(nf_ct_is_dying(ct
)))
640 /* See if there's one in the list already, including reverse:
641 NAT could have grabbed it without realizing, since we're
642 not in the hash. If there is, we lost race. */
643 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[hash
], hnnode
)
644 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
646 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h
), zone
,
649 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[reply_hash
], hnnode
)
650 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
652 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h
), zone
,
656 /* Timer relative to confirmation time, not original
657 setting time, otherwise we'd get timer wrap in
658 weird delay cases. */
659 ct
->timeout
.expires
+= jiffies
;
660 add_timer(&ct
->timeout
);
661 atomic_inc(&ct
->ct_general
.use
);
662 ct
->status
|= IPS_CONFIRMED
;
664 /* set conntrack timestamp, if enabled. */
665 tstamp
= nf_conn_tstamp_find(ct
);
667 if (skb
->tstamp
.tv64
== 0)
668 __net_timestamp(skb
);
670 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
672 /* Since the lookup is lockless, hash insertion must be done after
673 * starting the timer and setting the CONFIRMED bit. The RCU barriers
674 * guarantee that no other CPU can find the conntrack before the above
675 * stores are visible.
677 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
678 nf_conntrack_double_unlock(hash
, reply_hash
);
679 NF_CT_STAT_INC(net
, insert
);
682 help
= nfct_help(ct
);
683 if (help
&& help
->helper
)
684 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
686 nf_conntrack_event_cache(master_ct(ct
) ?
687 IPCT_RELATED
: IPCT_NEW
, ct
);
691 nf_ct_add_to_dying_list(ct
);
692 nf_conntrack_double_unlock(hash
, reply_hash
);
693 NF_CT_STAT_INC(net
, insert_failed
);
697 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
699 /* Returns true if a connection correspondings to the tuple (required
702 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
703 const struct nf_conn
*ignored_conntrack
)
705 struct net
*net
= nf_ct_net(ignored_conntrack
);
706 const struct nf_conntrack_zone
*zone
;
707 struct nf_conntrack_tuple_hash
*h
;
708 struct hlist_nulls_node
*n
;
712 zone
= nf_ct_zone(ignored_conntrack
);
713 hash
= hash_conntrack(net
, tuple
);
715 /* Disable BHs the entire time since we need to disable them at
716 * least once for the stats anyway.
719 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
], hnnode
) {
720 ct
= nf_ct_tuplehash_to_ctrack(h
);
721 if (ct
!= ignored_conntrack
&&
722 nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
723 nf_ct_zone_equal(ct
, zone
, NF_CT_DIRECTION(h
))) {
724 NF_CT_STAT_INC(net
, found
);
725 rcu_read_unlock_bh();
728 NF_CT_STAT_INC(net
, searched
);
730 rcu_read_unlock_bh();
734 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
736 #define NF_CT_EVICTION_RANGE 8
738 /* There's a small race here where we may free a just-assured
739 connection. Too bad: we're in trouble anyway. */
740 static noinline
int early_drop(struct net
*net
, unsigned int _hash
)
742 /* Use oldest entry, which is roughly LRU */
743 struct nf_conntrack_tuple_hash
*h
;
744 struct nf_conn
*ct
= NULL
, *tmp
;
745 struct hlist_nulls_node
*n
;
746 unsigned int i
= 0, cnt
= 0;
748 unsigned int hash
, sequence
;
753 sequence
= read_seqcount_begin(&net
->ct
.generation
);
754 hash
= hash_bucket(_hash
, net
);
755 for (; i
< net
->ct
.htable_size
; i
++) {
756 lockp
= &nf_conntrack_locks
[hash
% CONNTRACK_LOCKS
];
758 if (read_seqcount_retry(&net
->ct
.generation
, sequence
)) {
762 hlist_nulls_for_each_entry_rcu(h
, n
, &net
->ct
.hash
[hash
],
764 tmp
= nf_ct_tuplehash_to_ctrack(h
);
765 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
) &&
766 !nf_ct_is_dying(tmp
) &&
767 atomic_inc_not_zero(&tmp
->ct_general
.use
)) {
774 hash
= (hash
+ 1) % net
->ct
.htable_size
;
777 if (ct
|| cnt
>= NF_CT_EVICTION_RANGE
)
786 if (del_timer(&ct
->timeout
)) {
787 if (nf_ct_delete(ct
, 0, 0)) {
789 NF_CT_STAT_INC_ATOMIC(net
, early_drop
);
796 void init_nf_conntrack_hash_rnd(void)
801 * Why not initialize nf_conntrack_rnd in a "init()" function ?
802 * Because there isn't enough entropy when system initializing,
803 * and we initialize it as late as possible.
806 get_random_bytes(&rand
, sizeof(rand
));
808 cmpxchg(&nf_conntrack_hash_rnd
, 0, rand
);
811 static struct nf_conn
*
812 __nf_conntrack_alloc(struct net
*net
,
813 const struct nf_conntrack_zone
*zone
,
814 const struct nf_conntrack_tuple
*orig
,
815 const struct nf_conntrack_tuple
*repl
,
820 if (unlikely(!nf_conntrack_hash_rnd
)) {
821 init_nf_conntrack_hash_rnd();
822 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
823 hash
= hash_conntrack_raw(orig
);
826 /* We don't want any race condition at early drop stage */
827 atomic_inc(&net
->ct
.count
);
829 if (nf_conntrack_max
&&
830 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
831 if (!early_drop(net
, hash
)) {
832 atomic_dec(&net
->ct
.count
);
833 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
834 return ERR_PTR(-ENOMEM
);
839 * Do not use kmem_cache_zalloc(), as this cache uses
840 * SLAB_DESTROY_BY_RCU.
842 ct
= kmem_cache_alloc(net
->ct
.nf_conntrack_cachep
, gfp
);
846 spin_lock_init(&ct
->lock
);
847 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
848 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
849 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
850 /* save hash for reusing when confirming */
851 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
853 /* Don't set timer yet: wait for confirmation */
854 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
855 write_pnet(&ct
->ct_net
, net
);
856 memset(&ct
->__nfct_init_offset
[0], 0,
857 offsetof(struct nf_conn
, proto
) -
858 offsetof(struct nf_conn
, __nfct_init_offset
[0]));
860 if (zone
&& nf_ct_zone_add(ct
, GFP_ATOMIC
, zone
) < 0)
863 /* Because we use RCU lookups, we set ct_general.use to zero before
864 * this is inserted in any list.
866 atomic_set(&ct
->ct_general
.use
, 0);
869 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
871 atomic_dec(&net
->ct
.count
);
872 return ERR_PTR(-ENOMEM
);
875 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
876 const struct nf_conntrack_zone
*zone
,
877 const struct nf_conntrack_tuple
*orig
,
878 const struct nf_conntrack_tuple
*repl
,
881 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
883 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
885 void nf_conntrack_free(struct nf_conn
*ct
)
887 struct net
*net
= nf_ct_net(ct
);
889 /* A freed object has refcnt == 0, that's
890 * the golden rule for SLAB_DESTROY_BY_RCU
892 NF_CT_ASSERT(atomic_read(&ct
->ct_general
.use
) == 0);
894 nf_ct_ext_destroy(ct
);
896 kmem_cache_free(net
->ct
.nf_conntrack_cachep
, ct
);
897 smp_mb__before_atomic();
898 atomic_dec(&net
->ct
.count
);
900 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
903 /* Allocate a new conntrack: we return -ENOMEM if classification
904 failed due to stress. Otherwise it really is unclassifiable. */
905 static struct nf_conntrack_tuple_hash
*
906 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
907 const struct nf_conntrack_tuple
*tuple
,
908 struct nf_conntrack_l3proto
*l3proto
,
909 struct nf_conntrack_l4proto
*l4proto
,
911 unsigned int dataoff
, u32 hash
)
914 struct nf_conn_help
*help
;
915 struct nf_conntrack_tuple repl_tuple
;
916 struct nf_conntrack_ecache
*ecache
;
917 struct nf_conntrack_expect
*exp
= NULL
;
918 const struct nf_conntrack_zone
*zone
;
919 struct nf_conn_timeout
*timeout_ext
;
920 struct nf_conntrack_zone tmp
;
921 unsigned int *timeouts
;
923 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
924 pr_debug("Can't invert tuple.\n");
928 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
929 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
932 return (struct nf_conntrack_tuple_hash
*)ct
;
934 if (tmpl
&& nfct_synproxy(tmpl
)) {
935 nfct_seqadj_ext_add(ct
);
936 nfct_synproxy_ext_add(ct
);
939 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
941 timeouts
= NF_CT_TIMEOUT_EXT_DATA(timeout_ext
);
943 timeouts
= l4proto
->get_timeouts(net
);
945 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
946 nf_conntrack_free(ct
);
947 pr_debug("init conntrack: can't track with proto module\n");
952 nf_ct_timeout_ext_add(ct
, timeout_ext
->timeout
, GFP_ATOMIC
);
954 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
955 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
956 nf_ct_labels_ext_add(ct
);
958 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
959 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
960 ecache
? ecache
->expmask
: 0,
964 if (net
->ct
.expect_count
) {
965 spin_lock(&nf_conntrack_expect_lock
);
966 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
968 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
970 /* Welcome, Mr. Bond. We've been expecting you... */
971 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
972 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
973 ct
->master
= exp
->master
;
975 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
978 rcu_assign_pointer(help
->helper
, exp
->helper
);
981 #ifdef CONFIG_NF_CONNTRACK_MARK
982 ct
->mark
= exp
->master
->mark
;
984 #ifdef CONFIG_NF_CONNTRACK_SECMARK
985 ct
->secmark
= exp
->master
->secmark
;
987 NF_CT_STAT_INC(net
, expect_new
);
989 spin_unlock(&nf_conntrack_expect_lock
);
992 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
993 NF_CT_STAT_INC(net
, new);
996 /* Now it is inserted into the unconfirmed list, bump refcount */
997 nf_conntrack_get(&ct
->ct_general
);
998 nf_ct_add_to_unconfirmed_list(ct
);
1004 exp
->expectfn(ct
, exp
);
1005 nf_ct_expect_put(exp
);
1008 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
1011 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1012 static inline struct nf_conn
*
1013 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
1014 struct sk_buff
*skb
,
1015 unsigned int dataoff
,
1018 struct nf_conntrack_l3proto
*l3proto
,
1019 struct nf_conntrack_l4proto
*l4proto
,
1021 enum ip_conntrack_info
*ctinfo
)
1023 const struct nf_conntrack_zone
*zone
;
1024 struct nf_conntrack_tuple tuple
;
1025 struct nf_conntrack_tuple_hash
*h
;
1026 struct nf_conntrack_zone tmp
;
1030 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
1031 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
1033 pr_debug("resolve_normal_ct: Can't get tuple\n");
1037 /* look for tuple match */
1038 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1039 hash
= hash_conntrack_raw(&tuple
);
1040 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
1042 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
1043 skb
, dataoff
, hash
);
1049 ct
= nf_ct_tuplehash_to_ctrack(h
);
1051 /* It exists; we have (non-exclusive) reference. */
1052 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
1053 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
1054 /* Please set reply bit if this packet OK */
1057 /* Once we've had two way comms, always ESTABLISHED. */
1058 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
1059 pr_debug("nf_conntrack_in: normal packet for %p\n", ct
);
1060 *ctinfo
= IP_CT_ESTABLISHED
;
1061 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
1062 pr_debug("nf_conntrack_in: related packet for %p\n",
1064 *ctinfo
= IP_CT_RELATED
;
1066 pr_debug("nf_conntrack_in: new packet for %p\n", ct
);
1067 *ctinfo
= IP_CT_NEW
;
1071 skb
->nfct
= &ct
->ct_general
;
1072 skb
->nfctinfo
= *ctinfo
;
1077 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
1078 struct sk_buff
*skb
)
1080 struct nf_conn
*ct
, *tmpl
= NULL
;
1081 enum ip_conntrack_info ctinfo
;
1082 struct nf_conntrack_l3proto
*l3proto
;
1083 struct nf_conntrack_l4proto
*l4proto
;
1084 unsigned int *timeouts
;
1085 unsigned int dataoff
;
1091 /* Previously seen (loopback or untracked)? Ignore. */
1092 tmpl
= (struct nf_conn
*)skb
->nfct
;
1093 if (!nf_ct_is_template(tmpl
)) {
1094 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
1100 /* rcu_read_lock()ed by nf_hook_slow */
1101 l3proto
= __nf_ct_l3proto_find(pf
);
1102 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
1103 &dataoff
, &protonum
);
1105 pr_debug("not prepared to track yet or error occurred\n");
1106 NF_CT_STAT_INC_ATOMIC(net
, error
);
1107 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1112 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
1114 /* It may be an special packet, error, unclean...
1115 * inverse of the return code tells to the netfilter
1116 * core what to do with the packet. */
1117 if (l4proto
->error
!= NULL
) {
1118 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
1121 NF_CT_STAT_INC_ATOMIC(net
, error
);
1122 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1126 /* ICMP[v6] protocol trackers may assign one conntrack. */
1131 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
1132 l3proto
, l4proto
, &set_reply
, &ctinfo
);
1134 /* Not valid part of a connection */
1135 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1141 /* Too stressed to deal. */
1142 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1147 NF_CT_ASSERT(skb
->nfct
);
1149 /* Decide what timeout policy we want to apply to this flow. */
1150 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1152 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1154 /* Invalid: inverse of the return code tells
1155 * the netfilter core what to do */
1156 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1157 nf_conntrack_put(skb
->nfct
);
1159 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1160 if (ret
== -NF_DROP
)
1161 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1166 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1167 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1170 /* Special case: we have to repeat this hook, assign the
1171 * template again to this packet. We assume that this packet
1172 * has no conntrack assigned. This is used by nf_ct_tcp. */
1173 if (ret
== NF_REPEAT
)
1174 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1181 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1183 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1184 const struct nf_conntrack_tuple
*orig
)
1189 ret
= nf_ct_invert_tuple(inverse
, orig
,
1190 __nf_ct_l3proto_find(orig
->src
.l3num
),
1191 __nf_ct_l4proto_find(orig
->src
.l3num
,
1192 orig
->dst
.protonum
));
1196 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1198 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1199 implicitly racy: see __nf_conntrack_confirm */
1200 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1201 const struct nf_conntrack_tuple
*newreply
)
1203 struct nf_conn_help
*help
= nfct_help(ct
);
1205 /* Should be unconfirmed, so not in hash table yet */
1206 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1208 pr_debug("Altering reply tuple of %p to ", ct
);
1209 nf_ct_dump_tuple(newreply
);
1211 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1212 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1216 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1219 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1221 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1222 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1223 enum ip_conntrack_info ctinfo
,
1224 const struct sk_buff
*skb
,
1225 unsigned long extra_jiffies
,
1228 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1231 /* Only update if this is not a fixed timeout */
1232 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1235 /* If not in hash table, timer will not be active yet */
1236 if (!nf_ct_is_confirmed(ct
)) {
1237 ct
->timeout
.expires
= extra_jiffies
;
1239 unsigned long newtime
= jiffies
+ extra_jiffies
;
1241 /* Only update the timeout if the new timeout is at least
1242 HZ jiffies from the old timeout. Need del_timer for race
1243 avoidance (may already be dying). */
1244 if (newtime
- ct
->timeout
.expires
>= HZ
)
1245 mod_timer_pending(&ct
->timeout
, newtime
);
1250 struct nf_conn_acct
*acct
;
1252 acct
= nf_conn_acct_find(ct
);
1254 struct nf_conn_counter
*counter
= acct
->counter
;
1256 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
1257 atomic64_add(skb
->len
, &counter
[CTINFO2DIR(ctinfo
)].bytes
);
1261 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1263 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1264 enum ip_conntrack_info ctinfo
,
1265 const struct sk_buff
*skb
,
1269 struct nf_conn_acct
*acct
;
1271 acct
= nf_conn_acct_find(ct
);
1273 struct nf_conn_counter
*counter
= acct
->counter
;
1275 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
1276 atomic64_add(skb
->len
- skb_network_offset(skb
),
1277 &counter
[CTINFO2DIR(ctinfo
)].bytes
);
1281 if (del_timer(&ct
->timeout
)) {
1282 ct
->timeout
.function((unsigned long)ct
);
1287 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1289 /* Built-in default zone used e.g. by modules. */
1290 const struct nf_conntrack_zone nf_ct_zone_dflt
= {
1291 .id
= NF_CT_DEFAULT_ZONE_ID
,
1292 .dir
= NF_CT_DEFAULT_ZONE_DIR
,
1294 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt
);
1296 #ifdef CONFIG_NF_CONNTRACK_ZONES
1297 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly
= {
1298 .len
= sizeof(struct nf_conntrack_zone
),
1299 .align
= __alignof__(struct nf_conntrack_zone
),
1300 .id
= NF_CT_EXT_ZONE
,
1304 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1306 #include <linux/netfilter/nfnetlink.h>
1307 #include <linux/netfilter/nfnetlink_conntrack.h>
1308 #include <linux/mutex.h>
1310 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1311 * in ip_conntrack_core, since we don't want the protocols to autoload
1312 * or depend on ctnetlink */
1313 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1314 const struct nf_conntrack_tuple
*tuple
)
1316 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1317 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1318 goto nla_put_failure
;
1324 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1326 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1327 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1328 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1330 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1332 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1333 struct nf_conntrack_tuple
*t
)
1335 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1338 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1339 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1343 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1345 int nf_ct_port_nlattr_tuple_size(void)
1347 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1349 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1352 /* Used by ipt_REJECT and ip6t_REJECT. */
1353 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1356 enum ip_conntrack_info ctinfo
;
1358 /* This ICMP is in reverse direction to the packet which caused it */
1359 ct
= nf_ct_get(skb
, &ctinfo
);
1360 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1361 ctinfo
= IP_CT_RELATED_REPLY
;
1363 ctinfo
= IP_CT_RELATED
;
1365 /* Attach to new skbuff, and increment count */
1366 nskb
->nfct
= &ct
->ct_general
;
1367 nskb
->nfctinfo
= ctinfo
;
1368 nf_conntrack_get(nskb
->nfct
);
1371 /* Bring out ya dead! */
1372 static struct nf_conn
*
1373 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1374 void *data
, unsigned int *bucket
)
1376 struct nf_conntrack_tuple_hash
*h
;
1378 struct hlist_nulls_node
*n
;
1382 for (; *bucket
< net
->ct
.htable_size
; (*bucket
)++) {
1383 lockp
= &nf_conntrack_locks
[*bucket
% CONNTRACK_LOCKS
];
1386 if (*bucket
< net
->ct
.htable_size
) {
1387 hlist_nulls_for_each_entry(h
, n
, &net
->ct
.hash
[*bucket
], hnnode
) {
1388 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1390 ct
= nf_ct_tuplehash_to_ctrack(h
);
1399 for_each_possible_cpu(cpu
) {
1400 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1402 spin_lock_bh(&pcpu
->lock
);
1403 hlist_nulls_for_each_entry(h
, n
, &pcpu
->unconfirmed
, hnnode
) {
1404 ct
= nf_ct_tuplehash_to_ctrack(h
);
1406 set_bit(IPS_DYING_BIT
, &ct
->status
);
1408 spin_unlock_bh(&pcpu
->lock
);
1412 atomic_inc(&ct
->ct_general
.use
);
1418 void nf_ct_iterate_cleanup(struct net
*net
,
1419 int (*iter
)(struct nf_conn
*i
, void *data
),
1420 void *data
, u32 portid
, int report
)
1423 unsigned int bucket
= 0;
1425 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1426 /* Time to push up daises... */
1427 if (del_timer(&ct
->timeout
))
1428 nf_ct_delete(ct
, portid
, report
);
1430 /* ... else the timer will get him soon. */
1435 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1437 static int kill_all(struct nf_conn
*i
, void *data
)
1442 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1444 if (is_vmalloc_addr(hash
))
1447 free_pages((unsigned long)hash
,
1448 get_order(sizeof(struct hlist_head
) * size
));
1450 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1452 static int untrack_refs(void)
1456 for_each_possible_cpu(cpu
) {
1457 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1459 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1464 void nf_conntrack_cleanup_start(void)
1466 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1469 void nf_conntrack_cleanup_end(void)
1471 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1472 while (untrack_refs() > 0)
1475 #ifdef CONFIG_NF_CONNTRACK_ZONES
1476 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1478 nf_conntrack_proto_fini();
1479 nf_conntrack_seqadj_fini();
1480 nf_conntrack_labels_fini();
1481 nf_conntrack_helper_fini();
1482 nf_conntrack_timeout_fini();
1483 nf_conntrack_ecache_fini();
1484 nf_conntrack_tstamp_fini();
1485 nf_conntrack_acct_fini();
1486 nf_conntrack_expect_fini();
1490 * Mishearing the voices in his head, our hero wonders how he's
1491 * supposed to kill the mall.
1493 void nf_conntrack_cleanup_net(struct net
*net
)
1497 list_add(&net
->exit_list
, &single
);
1498 nf_conntrack_cleanup_net_list(&single
);
1501 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1507 * This makes sure all current packets have passed through
1508 * netfilter framework. Roll on, two-stage module
1514 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1515 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1516 if (atomic_read(&net
->ct
.count
) != 0)
1521 goto i_see_dead_people
;
1524 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1525 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1526 nf_conntrack_proto_pernet_fini(net
);
1527 nf_conntrack_helper_pernet_fini(net
);
1528 nf_conntrack_ecache_pernet_fini(net
);
1529 nf_conntrack_tstamp_pernet_fini(net
);
1530 nf_conntrack_acct_pernet_fini(net
);
1531 nf_conntrack_expect_pernet_fini(net
);
1532 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1533 kfree(net
->ct
.slabname
);
1534 free_percpu(net
->ct
.stat
);
1535 free_percpu(net
->ct
.pcpu_lists
);
1539 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1541 struct hlist_nulls_head
*hash
;
1542 unsigned int nr_slots
, i
;
1545 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1546 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1547 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1548 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1551 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
1556 for (i
= 0; i
< nr_slots
; i
++)
1557 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1561 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1563 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1566 unsigned int hashsize
, old_size
;
1567 struct hlist_nulls_head
*hash
, *old_hash
;
1568 struct nf_conntrack_tuple_hash
*h
;
1571 if (current
->nsproxy
->net_ns
!= &init_net
)
1574 /* On boot, we can set this without any fancy locking. */
1575 if (!nf_conntrack_htable_size
)
1576 return param_set_uint(val
, kp
);
1578 rc
= kstrtouint(val
, 0, &hashsize
);
1584 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1589 nf_conntrack_all_lock();
1590 write_seqcount_begin(&init_net
.ct
.generation
);
1592 /* Lookups in the old hash might happen in parallel, which means we
1593 * might get false negatives during connection lookup. New connections
1594 * created because of a false negative won't make it into the hash
1595 * though since that required taking the locks.
1598 for (i
= 0; i
< init_net
.ct
.htable_size
; i
++) {
1599 while (!hlist_nulls_empty(&init_net
.ct
.hash
[i
])) {
1600 h
= hlist_nulls_entry(init_net
.ct
.hash
[i
].first
,
1601 struct nf_conntrack_tuple_hash
, hnnode
);
1602 ct
= nf_ct_tuplehash_to_ctrack(h
);
1603 hlist_nulls_del_rcu(&h
->hnnode
);
1604 bucket
= __hash_conntrack(&h
->tuple
, hashsize
);
1605 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1608 old_size
= init_net
.ct
.htable_size
;
1609 old_hash
= init_net
.ct
.hash
;
1611 init_net
.ct
.htable_size
= nf_conntrack_htable_size
= hashsize
;
1612 init_net
.ct
.hash
= hash
;
1614 write_seqcount_end(&init_net
.ct
.generation
);
1615 nf_conntrack_all_unlock();
1618 nf_ct_free_hashtable(old_hash
, old_size
);
1621 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1623 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1624 &nf_conntrack_htable_size
, 0600);
1626 void nf_ct_untracked_status_or(unsigned long bits
)
1630 for_each_possible_cpu(cpu
)
1631 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1633 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1635 int nf_conntrack_init_start(void)
1640 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
1641 spin_lock_init(&nf_conntrack_locks
[i
]);
1643 if (!nf_conntrack_htable_size
) {
1644 /* Idea from tcp.c: use 1/16384 of memory.
1645 * On i386: 32MB machine has 512 buckets.
1646 * >= 1GB machines have 16384 buckets.
1647 * >= 4GB machines have 65536 buckets.
1649 nf_conntrack_htable_size
1650 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1651 / sizeof(struct hlist_head
));
1652 if (totalram_pages
> (4 * (1024 * 1024 * 1024 / PAGE_SIZE
)))
1653 nf_conntrack_htable_size
= 65536;
1654 else if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1655 nf_conntrack_htable_size
= 16384;
1656 if (nf_conntrack_htable_size
< 32)
1657 nf_conntrack_htable_size
= 32;
1659 /* Use a max. factor of four by default to get the same max as
1660 * with the old struct list_heads. When a table size is given
1661 * we use the old value of 8 to avoid reducing the max.
1665 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1667 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1668 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1671 ret
= nf_conntrack_expect_init();
1675 ret
= nf_conntrack_acct_init();
1679 ret
= nf_conntrack_tstamp_init();
1683 ret
= nf_conntrack_ecache_init();
1687 ret
= nf_conntrack_timeout_init();
1691 ret
= nf_conntrack_helper_init();
1695 ret
= nf_conntrack_labels_init();
1699 ret
= nf_conntrack_seqadj_init();
1703 #ifdef CONFIG_NF_CONNTRACK_ZONES
1704 ret
= nf_ct_extend_register(&nf_ct_zone_extend
);
1708 ret
= nf_conntrack_proto_init();
1712 /* Set up fake conntrack: to never be deleted, not in any hashes */
1713 for_each_possible_cpu(cpu
) {
1714 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1715 write_pnet(&ct
->ct_net
, &init_net
);
1716 atomic_set(&ct
->ct_general
.use
, 1);
1718 /* - and look it like as a confirmed connection */
1719 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1723 #ifdef CONFIG_NF_CONNTRACK_ZONES
1724 nf_ct_extend_unregister(&nf_ct_zone_extend
);
1727 nf_conntrack_seqadj_fini();
1729 nf_conntrack_labels_fini();
1731 nf_conntrack_helper_fini();
1733 nf_conntrack_timeout_fini();
1735 nf_conntrack_ecache_fini();
1737 nf_conntrack_tstamp_fini();
1739 nf_conntrack_acct_fini();
1741 nf_conntrack_expect_fini();
1746 void nf_conntrack_init_end(void)
1748 /* For use by REJECT target */
1749 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1750 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1754 * We need to use special "null" values, not used in hash table
1756 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1757 #define DYING_NULLS_VAL ((1<<30)+1)
1758 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1760 int nf_conntrack_init_net(struct net
*net
)
1765 atomic_set(&net
->ct
.count
, 0);
1766 seqcount_init(&net
->ct
.generation
);
1768 net
->ct
.pcpu_lists
= alloc_percpu(struct ct_pcpu
);
1769 if (!net
->ct
.pcpu_lists
)
1772 for_each_possible_cpu(cpu
) {
1773 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1775 spin_lock_init(&pcpu
->lock
);
1776 INIT_HLIST_NULLS_HEAD(&pcpu
->unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1777 INIT_HLIST_NULLS_HEAD(&pcpu
->dying
, DYING_NULLS_VAL
);
1780 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1782 goto err_pcpu_lists
;
1784 net
->ct
.slabname
= kasprintf(GFP_KERNEL
, "nf_conntrack_%p", net
);
1785 if (!net
->ct
.slabname
)
1788 net
->ct
.nf_conntrack_cachep
= kmem_cache_create(net
->ct
.slabname
,
1789 sizeof(struct nf_conn
), 0,
1790 SLAB_DESTROY_BY_RCU
, NULL
);
1791 if (!net
->ct
.nf_conntrack_cachep
) {
1792 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1796 net
->ct
.htable_size
= nf_conntrack_htable_size
;
1797 net
->ct
.hash
= nf_ct_alloc_hashtable(&net
->ct
.htable_size
, 1);
1798 if (!net
->ct
.hash
) {
1799 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1802 ret
= nf_conntrack_expect_pernet_init(net
);
1805 ret
= nf_conntrack_acct_pernet_init(net
);
1808 ret
= nf_conntrack_tstamp_pernet_init(net
);
1811 ret
= nf_conntrack_ecache_pernet_init(net
);
1814 ret
= nf_conntrack_helper_pernet_init(net
);
1817 ret
= nf_conntrack_proto_pernet_init(net
);
1823 nf_conntrack_helper_pernet_fini(net
);
1825 nf_conntrack_ecache_pernet_fini(net
);
1827 nf_conntrack_tstamp_pernet_fini(net
);
1829 nf_conntrack_acct_pernet_fini(net
);
1831 nf_conntrack_expect_pernet_fini(net
);
1833 nf_ct_free_hashtable(net
->ct
.hash
, net
->ct
.htable_size
);
1835 kmem_cache_destroy(net
->ct
.nf_conntrack_cachep
);
1837 kfree(net
->ct
.slabname
);
1839 free_percpu(net
->ct
.stat
);
1841 free_percpu(net
->ct
.pcpu_lists
);