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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/types.h>
18 #include <linux/netfilter.h>
19 #include <linux/module.h>
20 #include <linux/sched.h>
21 #include <linux/skbuff.h>
22 #include <linux/proc_fs.h>
23 #include <linux/vmalloc.h>
24 #include <linux/stddef.h>
25 #include <linux/slab.h>
26 #include <linux/random.h>
27 #include <linux/jhash.h>
28 #include <linux/err.h>
29 #include <linux/percpu.h>
30 #include <linux/moduleparam.h>
31 #include <linux/notifier.h>
32 #include <linux/kernel.h>
33 #include <linux/netdevice.h>
34 #include <linux/socket.h>
36 #include <linux/nsproxy.h>
37 #include <linux/rculist_nulls.h>
39 #include <net/netfilter/nf_conntrack.h>
40 #include <net/netfilter/nf_conntrack_l3proto.h>
41 #include <net/netfilter/nf_conntrack_l4proto.h>
42 #include <net/netfilter/nf_conntrack_expect.h>
43 #include <net/netfilter/nf_conntrack_helper.h>
44 #include <net/netfilter/nf_conntrack_seqadj.h>
45 #include <net/netfilter/nf_conntrack_core.h>
46 #include <net/netfilter/nf_conntrack_extend.h>
47 #include <net/netfilter/nf_conntrack_acct.h>
48 #include <net/netfilter/nf_conntrack_ecache.h>
49 #include <net/netfilter/nf_conntrack_zones.h>
50 #include <net/netfilter/nf_conntrack_timestamp.h>
51 #include <net/netfilter/nf_conntrack_timeout.h>
52 #include <net/netfilter/nf_conntrack_labels.h>
53 #include <net/netfilter/nf_conntrack_synproxy.h>
54 #include <net/netfilter/nf_nat.h>
55 #include <net/netfilter/nf_nat_core.h>
56 #include <net/netfilter/nf_nat_helper.h>
57 #include <net/netns/hash.h>
59 #define NF_CONNTRACK_VERSION "0.5.0"
61 int (*nfnetlink_parse_nat_setup_hook
)(struct nf_conn
*ct
,
62 enum nf_nat_manip_type manip
,
63 const struct nlattr
*attr
) __read_mostly
;
64 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook
);
66 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks
[CONNTRACK_LOCKS
];
67 EXPORT_SYMBOL_GPL(nf_conntrack_locks
);
69 __cacheline_aligned_in_smp
DEFINE_SPINLOCK(nf_conntrack_expect_lock
);
70 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock
);
72 struct hlist_nulls_head
*nf_conntrack_hash __read_mostly
;
73 EXPORT_SYMBOL_GPL(nf_conntrack_hash
);
75 struct conntrack_gc_work
{
76 struct delayed_work dwork
;
82 static __read_mostly
struct kmem_cache
*nf_conntrack_cachep
;
83 static __read_mostly spinlock_t nf_conntrack_locks_all_lock
;
84 static __read_mostly
DEFINE_SPINLOCK(nf_conntrack_locks_all_lock
);
85 static __read_mostly
bool nf_conntrack_locks_all
;
87 /* every gc cycle scans at most 1/GC_MAX_BUCKETS_DIV part of table */
88 #define GC_MAX_BUCKETS_DIV 128u
89 /* upper bound of full table scan */
90 #define GC_MAX_SCAN_JIFFIES (16u * HZ)
91 /* desired ratio of entries found to be expired */
92 #define GC_EVICT_RATIO 50u
94 static struct conntrack_gc_work conntrack_gc_work
;
96 void nf_conntrack_lock(spinlock_t
*lock
) __acquires(lock
)
99 while (unlikely(nf_conntrack_locks_all
)) {
103 * Order the 'nf_conntrack_locks_all' load vs. the
104 * spin_unlock_wait() loads below, to ensure
105 * that 'nf_conntrack_locks_all_lock' is indeed held:
107 smp_rmb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
108 spin_unlock_wait(&nf_conntrack_locks_all_lock
);
112 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
114 static void nf_conntrack_double_unlock(unsigned int h1
, unsigned int h2
)
116 h1
%= CONNTRACK_LOCKS
;
117 h2
%= CONNTRACK_LOCKS
;
118 spin_unlock(&nf_conntrack_locks
[h1
]);
120 spin_unlock(&nf_conntrack_locks
[h2
]);
123 /* return true if we need to recompute hashes (in case hash table was resized) */
124 static bool nf_conntrack_double_lock(struct net
*net
, unsigned int h1
,
125 unsigned int h2
, unsigned int sequence
)
127 h1
%= CONNTRACK_LOCKS
;
128 h2
%= CONNTRACK_LOCKS
;
130 nf_conntrack_lock(&nf_conntrack_locks
[h1
]);
132 spin_lock_nested(&nf_conntrack_locks
[h2
],
133 SINGLE_DEPTH_NESTING
);
135 nf_conntrack_lock(&nf_conntrack_locks
[h2
]);
136 spin_lock_nested(&nf_conntrack_locks
[h1
],
137 SINGLE_DEPTH_NESTING
);
139 if (read_seqcount_retry(&nf_conntrack_generation
, sequence
)) {
140 nf_conntrack_double_unlock(h1
, h2
);
146 static void nf_conntrack_all_lock(void)
150 spin_lock(&nf_conntrack_locks_all_lock
);
151 nf_conntrack_locks_all
= true;
154 * Order the above store of 'nf_conntrack_locks_all' against
155 * the spin_unlock_wait() loads below, such that if
156 * nf_conntrack_lock() observes 'nf_conntrack_locks_all'
157 * we must observe nf_conntrack_locks[] held:
159 smp_mb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
161 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++) {
162 spin_unlock_wait(&nf_conntrack_locks
[i
]);
166 static void nf_conntrack_all_unlock(void)
169 * All prior stores must be complete before we clear
170 * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
171 * might observe the false value but not the entire
174 smp_store_release(&nf_conntrack_locks_all
, false);
175 spin_unlock(&nf_conntrack_locks_all_lock
);
178 unsigned int nf_conntrack_htable_size __read_mostly
;
179 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
181 unsigned int nf_conntrack_max __read_mostly
;
182 seqcount_t nf_conntrack_generation __read_mostly
;
184 /* nf_conn must be 8 bytes aligned, as the 3 LSB bits are used
185 * for the nfctinfo. We cheat by (ab)using the PER CPU cache line
186 * alignment to enforce this.
188 DEFINE_PER_CPU_ALIGNED(struct nf_conn
, nf_conntrack_untracked
);
189 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
191 static unsigned int nf_conntrack_hash_rnd __read_mostly
;
193 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
,
194 const struct net
*net
)
199 get_random_once(&nf_conntrack_hash_rnd
, sizeof(nf_conntrack_hash_rnd
));
201 /* The direction must be ignored, so we hash everything up to the
202 * destination ports (which is a multiple of 4) and treat the last
203 * three bytes manually.
205 seed
= nf_conntrack_hash_rnd
^ net_hash_mix(net
);
206 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
207 return jhash2((u32
*)tuple
, n
, seed
^
208 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
209 tuple
->dst
.protonum
));
212 static u32
scale_hash(u32 hash
)
214 return reciprocal_scale(hash
, nf_conntrack_htable_size
);
217 static u32
__hash_conntrack(const struct net
*net
,
218 const struct nf_conntrack_tuple
*tuple
,
221 return reciprocal_scale(hash_conntrack_raw(tuple
, net
), size
);
224 static u32
hash_conntrack(const struct net
*net
,
225 const struct nf_conntrack_tuple
*tuple
)
227 return scale_hash(hash_conntrack_raw(tuple
, net
));
231 nf_ct_get_tuple(const struct sk_buff
*skb
,
233 unsigned int dataoff
,
237 struct nf_conntrack_tuple
*tuple
,
238 const struct nf_conntrack_l3proto
*l3proto
,
239 const struct nf_conntrack_l4proto
*l4proto
)
241 memset(tuple
, 0, sizeof(*tuple
));
243 tuple
->src
.l3num
= l3num
;
244 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
247 tuple
->dst
.protonum
= protonum
;
248 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
250 return l4proto
->pkt_to_tuple(skb
, dataoff
, net
, tuple
);
252 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
254 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
256 struct net
*net
, struct nf_conntrack_tuple
*tuple
)
258 struct nf_conntrack_l3proto
*l3proto
;
259 struct nf_conntrack_l4proto
*l4proto
;
260 unsigned int protoff
;
266 l3proto
= __nf_ct_l3proto_find(l3num
);
267 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
268 if (ret
!= NF_ACCEPT
) {
273 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
275 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, net
, tuple
,
281 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
284 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
285 const struct nf_conntrack_tuple
*orig
,
286 const struct nf_conntrack_l3proto
*l3proto
,
287 const struct nf_conntrack_l4proto
*l4proto
)
289 memset(inverse
, 0, sizeof(*inverse
));
291 inverse
->src
.l3num
= orig
->src
.l3num
;
292 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
295 inverse
->dst
.dir
= !orig
->dst
.dir
;
297 inverse
->dst
.protonum
= orig
->dst
.protonum
;
298 return l4proto
->invert_tuple(inverse
, orig
);
300 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
303 clean_from_lists(struct nf_conn
*ct
)
305 pr_debug("clean_from_lists(%p)\n", ct
);
306 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
307 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
309 /* Destroy all pending expectations */
310 nf_ct_remove_expectations(ct
);
313 /* must be called with local_bh_disable */
314 static void nf_ct_add_to_dying_list(struct nf_conn
*ct
)
316 struct ct_pcpu
*pcpu
;
318 /* add this conntrack to the (per cpu) dying list */
319 ct
->cpu
= smp_processor_id();
320 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
322 spin_lock(&pcpu
->lock
);
323 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
325 spin_unlock(&pcpu
->lock
);
328 /* must be called with local_bh_disable */
329 static void nf_ct_add_to_unconfirmed_list(struct nf_conn
*ct
)
331 struct ct_pcpu
*pcpu
;
333 /* add this conntrack to the (per cpu) unconfirmed list */
334 ct
->cpu
= smp_processor_id();
335 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
337 spin_lock(&pcpu
->lock
);
338 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
340 spin_unlock(&pcpu
->lock
);
343 /* must be called with local_bh_disable */
344 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn
*ct
)
346 struct ct_pcpu
*pcpu
;
348 /* We overload first tuple to link into unconfirmed or dying list.*/
349 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
351 spin_lock(&pcpu
->lock
);
352 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
353 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
354 spin_unlock(&pcpu
->lock
);
357 #define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
359 /* Released via destroy_conntrack() */
360 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
361 const struct nf_conntrack_zone
*zone
,
364 struct nf_conn
*tmpl
, *p
;
366 if (ARCH_KMALLOC_MINALIGN
<= NFCT_INFOMASK
) {
367 tmpl
= kzalloc(sizeof(*tmpl
) + NFCT_INFOMASK
, flags
);
372 tmpl
= (struct nf_conn
*)NFCT_ALIGN((unsigned long)p
);
374 tmpl
= (struct nf_conn
*)NFCT_ALIGN((unsigned long)p
);
375 tmpl
->proto
.tmpl_padto
= (char *)tmpl
- (char *)p
;
378 tmpl
= kzalloc(sizeof(*tmpl
), flags
);
383 tmpl
->status
= IPS_TEMPLATE
;
384 write_pnet(&tmpl
->ct_net
, net
);
385 nf_ct_zone_add(tmpl
, zone
);
386 atomic_set(&tmpl
->ct_general
.use
, 0);
390 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc
);
392 void nf_ct_tmpl_free(struct nf_conn
*tmpl
)
394 nf_ct_ext_destroy(tmpl
);
395 nf_ct_ext_free(tmpl
);
397 if (ARCH_KMALLOC_MINALIGN
<= NFCT_INFOMASK
)
398 kfree((char *)tmpl
- tmpl
->proto
.tmpl_padto
);
402 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free
);
405 destroy_conntrack(struct nf_conntrack
*nfct
)
407 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
408 struct nf_conntrack_l4proto
*l4proto
;
410 pr_debug("destroy_conntrack(%p)\n", ct
);
411 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
413 if (unlikely(nf_ct_is_template(ct
))) {
418 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
419 if (l4proto
->destroy
)
420 l4proto
->destroy(ct
);
425 /* Expectations will have been removed in clean_from_lists,
426 * except TFTP can create an expectation on the first packet,
427 * before connection is in the list, so we need to clean here,
430 nf_ct_remove_expectations(ct
);
432 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
437 nf_ct_put(ct
->master
);
439 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
440 nf_conntrack_free(ct
);
443 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
445 struct net
*net
= nf_ct_net(ct
);
446 unsigned int hash
, reply_hash
;
447 unsigned int sequence
;
449 nf_ct_helper_destroy(ct
);
453 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
454 hash
= hash_conntrack(net
,
455 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
456 reply_hash
= hash_conntrack(net
,
457 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
458 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
460 clean_from_lists(ct
);
461 nf_conntrack_double_unlock(hash
, reply_hash
);
463 nf_ct_add_to_dying_list(ct
);
468 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
470 struct nf_conn_tstamp
*tstamp
;
472 if (test_and_set_bit(IPS_DYING_BIT
, &ct
->status
))
475 tstamp
= nf_conn_tstamp_find(ct
);
476 if (tstamp
&& tstamp
->stop
== 0)
477 tstamp
->stop
= ktime_get_real_ns();
479 if (nf_conntrack_event_report(IPCT_DESTROY
, ct
,
480 portid
, report
) < 0) {
481 /* destroy event was not delivered. nf_ct_put will
482 * be done by event cache worker on redelivery.
484 nf_ct_delete_from_lists(ct
);
485 nf_conntrack_ecache_delayed_work(nf_ct_net(ct
));
489 nf_conntrack_ecache_work(nf_ct_net(ct
));
490 nf_ct_delete_from_lists(ct
);
494 EXPORT_SYMBOL_GPL(nf_ct_delete
);
497 nf_ct_key_equal(struct nf_conntrack_tuple_hash
*h
,
498 const struct nf_conntrack_tuple
*tuple
,
499 const struct nf_conntrack_zone
*zone
,
500 const struct net
*net
)
502 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
504 /* A conntrack can be recreated with the equal tuple,
505 * so we need to check that the conntrack is confirmed
507 return nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
508 nf_ct_zone_equal(ct
, zone
, NF_CT_DIRECTION(h
)) &&
509 nf_ct_is_confirmed(ct
) &&
510 net_eq(net
, nf_ct_net(ct
));
513 /* caller must hold rcu readlock and none of the nf_conntrack_locks */
514 static void nf_ct_gc_expired(struct nf_conn
*ct
)
516 if (!atomic_inc_not_zero(&ct
->ct_general
.use
))
519 if (nf_ct_should_gc(ct
))
527 * - Caller must take a reference on returned object
528 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
530 static struct nf_conntrack_tuple_hash
*
531 ____nf_conntrack_find(struct net
*net
, const struct nf_conntrack_zone
*zone
,
532 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
534 struct nf_conntrack_tuple_hash
*h
;
535 struct hlist_nulls_head
*ct_hash
;
536 struct hlist_nulls_node
*n
;
537 unsigned int bucket
, hsize
;
540 nf_conntrack_get_ht(&ct_hash
, &hsize
);
541 bucket
= reciprocal_scale(hash
, hsize
);
543 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[bucket
], hnnode
) {
546 ct
= nf_ct_tuplehash_to_ctrack(h
);
547 if (nf_ct_is_expired(ct
)) {
548 nf_ct_gc_expired(ct
);
552 if (nf_ct_is_dying(ct
))
555 if (nf_ct_key_equal(h
, tuple
, zone
, net
))
559 * if the nulls value we got at the end of this lookup is
560 * not the expected one, we must restart lookup.
561 * We probably met an item that was moved to another chain.
563 if (get_nulls_value(n
) != bucket
) {
564 NF_CT_STAT_INC_ATOMIC(net
, search_restart
);
571 /* Find a connection corresponding to a tuple. */
572 static struct nf_conntrack_tuple_hash
*
573 __nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
574 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
576 struct nf_conntrack_tuple_hash
*h
;
581 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
583 ct
= nf_ct_tuplehash_to_ctrack(h
);
584 if (unlikely(nf_ct_is_dying(ct
) ||
585 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
588 if (unlikely(!nf_ct_key_equal(h
, tuple
, zone
, net
))) {
599 struct nf_conntrack_tuple_hash
*
600 nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
601 const struct nf_conntrack_tuple
*tuple
)
603 return __nf_conntrack_find_get(net
, zone
, tuple
,
604 hash_conntrack_raw(tuple
, net
));
606 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
608 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
610 unsigned int reply_hash
)
612 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
613 &nf_conntrack_hash
[hash
]);
614 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
615 &nf_conntrack_hash
[reply_hash
]);
619 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
621 const struct nf_conntrack_zone
*zone
;
622 struct net
*net
= nf_ct_net(ct
);
623 unsigned int hash
, reply_hash
;
624 struct nf_conntrack_tuple_hash
*h
;
625 struct hlist_nulls_node
*n
;
626 unsigned int sequence
;
628 zone
= nf_ct_zone(ct
);
632 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
633 hash
= hash_conntrack(net
,
634 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
635 reply_hash
= hash_conntrack(net
,
636 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
637 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
639 /* See if there's one in the list already, including reverse */
640 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
641 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
645 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
646 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
651 /* The caller holds a reference to this object */
652 atomic_set(&ct
->ct_general
.use
, 2);
653 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
654 nf_conntrack_double_unlock(hash
, reply_hash
);
655 NF_CT_STAT_INC(net
, insert
);
660 nf_conntrack_double_unlock(hash
, reply_hash
);
661 NF_CT_STAT_INC(net
, insert_failed
);
665 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
667 static inline void nf_ct_acct_update(struct nf_conn
*ct
,
668 enum ip_conntrack_info ctinfo
,
671 struct nf_conn_acct
*acct
;
673 acct
= nf_conn_acct_find(ct
);
675 struct nf_conn_counter
*counter
= acct
->counter
;
677 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
678 atomic64_add(len
, &counter
[CTINFO2DIR(ctinfo
)].bytes
);
682 static void nf_ct_acct_merge(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
683 const struct nf_conn
*loser_ct
)
685 struct nf_conn_acct
*acct
;
687 acct
= nf_conn_acct_find(loser_ct
);
689 struct nf_conn_counter
*counter
= acct
->counter
;
692 /* u32 should be fine since we must have seen one packet. */
693 bytes
= atomic64_read(&counter
[CTINFO2DIR(ctinfo
)].bytes
);
694 nf_ct_acct_update(ct
, ctinfo
, bytes
);
698 /* Resolve race on insertion if this protocol allows this. */
699 static int nf_ct_resolve_clash(struct net
*net
, struct sk_buff
*skb
,
700 enum ip_conntrack_info ctinfo
,
701 struct nf_conntrack_tuple_hash
*h
)
703 /* This is the conntrack entry already in hashes that won race. */
704 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
705 struct nf_conntrack_l4proto
*l4proto
;
707 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
708 if (l4proto
->allow_clash
&&
710 !nf_ct_is_dying(ct
) &&
711 atomic_inc_not_zero(&ct
->ct_general
.use
)) {
712 enum ip_conntrack_info oldinfo
;
713 struct nf_conn
*loser_ct
= nf_ct_get(skb
, &oldinfo
);
715 nf_ct_acct_merge(ct
, ctinfo
, loser_ct
);
716 nf_conntrack_put(&loser_ct
->ct_general
);
717 nf_ct_set(skb
, ct
, oldinfo
);
720 NF_CT_STAT_INC(net
, drop
);
724 /* Confirm a connection given skb; places it in hash table */
726 __nf_conntrack_confirm(struct sk_buff
*skb
)
728 const struct nf_conntrack_zone
*zone
;
729 unsigned int hash
, reply_hash
;
730 struct nf_conntrack_tuple_hash
*h
;
732 struct nf_conn_help
*help
;
733 struct nf_conn_tstamp
*tstamp
;
734 struct hlist_nulls_node
*n
;
735 enum ip_conntrack_info ctinfo
;
737 unsigned int sequence
;
740 ct
= nf_ct_get(skb
, &ctinfo
);
743 /* ipt_REJECT uses nf_conntrack_attach to attach related
744 ICMP/TCP RST packets in other direction. Actual packet
745 which created connection will be IP_CT_NEW or for an
746 expected connection, IP_CT_RELATED. */
747 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
750 zone
= nf_ct_zone(ct
);
754 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
755 /* reuse the hash saved before */
756 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
757 hash
= scale_hash(hash
);
758 reply_hash
= hash_conntrack(net
,
759 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
761 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
763 /* We're not in hash table, and we refuse to set up related
764 * connections for unconfirmed conns. But packet copies and
765 * REJECT will give spurious warnings here.
767 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
769 /* No external references means no one else could have
772 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
773 pr_debug("Confirming conntrack %p\n", ct
);
774 /* We have to check the DYING flag after unlink to prevent
775 * a race against nf_ct_get_next_corpse() possibly called from
776 * user context, else we insert an already 'dead' hash, blocking
777 * further use of that particular connection -JM.
779 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
781 if (unlikely(nf_ct_is_dying(ct
))) {
782 nf_ct_add_to_dying_list(ct
);
786 /* See if there's one in the list already, including reverse:
787 NAT could have grabbed it without realizing, since we're
788 not in the hash. If there is, we lost race. */
789 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
790 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
794 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
795 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
799 /* Timer relative to confirmation time, not original
800 setting time, otherwise we'd get timer wrap in
801 weird delay cases. */
802 ct
->timeout
+= nfct_time_stamp
;
803 atomic_inc(&ct
->ct_general
.use
);
804 ct
->status
|= IPS_CONFIRMED
;
806 /* set conntrack timestamp, if enabled. */
807 tstamp
= nf_conn_tstamp_find(ct
);
809 if (skb
->tstamp
== 0)
810 __net_timestamp(skb
);
812 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
814 /* Since the lookup is lockless, hash insertion must be done after
815 * starting the timer and setting the CONFIRMED bit. The RCU barriers
816 * guarantee that no other CPU can find the conntrack before the above
817 * stores are visible.
819 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
820 nf_conntrack_double_unlock(hash
, reply_hash
);
823 help
= nfct_help(ct
);
824 if (help
&& help
->helper
)
825 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
827 nf_conntrack_event_cache(master_ct(ct
) ?
828 IPCT_RELATED
: IPCT_NEW
, ct
);
832 nf_ct_add_to_dying_list(ct
);
833 ret
= nf_ct_resolve_clash(net
, skb
, ctinfo
, h
);
835 nf_conntrack_double_unlock(hash
, reply_hash
);
836 NF_CT_STAT_INC(net
, insert_failed
);
840 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
842 /* Returns true if a connection correspondings to the tuple (required
845 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
846 const struct nf_conn
*ignored_conntrack
)
848 struct net
*net
= nf_ct_net(ignored_conntrack
);
849 const struct nf_conntrack_zone
*zone
;
850 struct nf_conntrack_tuple_hash
*h
;
851 struct hlist_nulls_head
*ct_hash
;
852 unsigned int hash
, hsize
;
853 struct hlist_nulls_node
*n
;
856 zone
= nf_ct_zone(ignored_conntrack
);
860 nf_conntrack_get_ht(&ct_hash
, &hsize
);
861 hash
= __hash_conntrack(net
, tuple
, hsize
);
863 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[hash
], hnnode
) {
864 ct
= nf_ct_tuplehash_to_ctrack(h
);
866 if (ct
== ignored_conntrack
)
869 if (nf_ct_is_expired(ct
)) {
870 nf_ct_gc_expired(ct
);
874 if (nf_ct_key_equal(h
, tuple
, zone
, net
)) {
875 NF_CT_STAT_INC_ATOMIC(net
, found
);
881 if (get_nulls_value(n
) != hash
) {
882 NF_CT_STAT_INC_ATOMIC(net
, search_restart
);
890 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
892 #define NF_CT_EVICTION_RANGE 8
894 /* There's a small race here where we may free a just-assured
895 connection. Too bad: we're in trouble anyway. */
896 static unsigned int early_drop_list(struct net
*net
,
897 struct hlist_nulls_head
*head
)
899 struct nf_conntrack_tuple_hash
*h
;
900 struct hlist_nulls_node
*n
;
901 unsigned int drops
= 0;
904 hlist_nulls_for_each_entry_rcu(h
, n
, head
, hnnode
) {
905 tmp
= nf_ct_tuplehash_to_ctrack(h
);
907 if (nf_ct_is_expired(tmp
)) {
908 nf_ct_gc_expired(tmp
);
912 if (test_bit(IPS_ASSURED_BIT
, &tmp
->status
) ||
913 !net_eq(nf_ct_net(tmp
), net
) ||
917 if (!atomic_inc_not_zero(&tmp
->ct_general
.use
))
920 /* kill only if still in same netns -- might have moved due to
921 * SLAB_DESTROY_BY_RCU rules.
923 * We steal the timer reference. If that fails timer has
924 * already fired or someone else deleted it. Just drop ref
925 * and move to next entry.
927 if (net_eq(nf_ct_net(tmp
), net
) &&
928 nf_ct_is_confirmed(tmp
) &&
929 nf_ct_delete(tmp
, 0, 0))
938 static noinline
int early_drop(struct net
*net
, unsigned int _hash
)
942 for (i
= 0; i
< NF_CT_EVICTION_RANGE
; i
++) {
943 struct hlist_nulls_head
*ct_hash
;
944 unsigned int hash
, hsize
, drops
;
947 nf_conntrack_get_ht(&ct_hash
, &hsize
);
948 hash
= reciprocal_scale(_hash
++, hsize
);
950 drops
= early_drop_list(net
, &ct_hash
[hash
]);
954 NF_CT_STAT_ADD_ATOMIC(net
, early_drop
, drops
);
962 static void gc_worker(struct work_struct
*work
)
964 unsigned int min_interval
= max(HZ
/ GC_MAX_BUCKETS_DIV
, 1u);
965 unsigned int i
, goal
, buckets
= 0, expired_count
= 0;
966 struct conntrack_gc_work
*gc_work
;
967 unsigned int ratio
, scanned
= 0;
968 unsigned long next_run
;
970 gc_work
= container_of(work
, struct conntrack_gc_work
, dwork
.work
);
972 goal
= nf_conntrack_htable_size
/ GC_MAX_BUCKETS_DIV
;
973 i
= gc_work
->last_bucket
;
976 struct nf_conntrack_tuple_hash
*h
;
977 struct hlist_nulls_head
*ct_hash
;
978 struct hlist_nulls_node
*n
;
985 nf_conntrack_get_ht(&ct_hash
, &hashsz
);
989 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[i
], hnnode
) {
990 tmp
= nf_ct_tuplehash_to_ctrack(h
);
993 if (nf_ct_is_expired(tmp
)) {
994 nf_ct_gc_expired(tmp
);
1000 /* could check get_nulls_value() here and restart if ct
1001 * was moved to another chain. But given gc is best-effort
1002 * we will just continue with next hash slot.
1005 cond_resched_rcu_qs();
1006 } while (++buckets
< goal
);
1008 if (gc_work
->exiting
)
1012 * Eviction will normally happen from the packet path, and not
1013 * from this gc worker.
1015 * This worker is only here to reap expired entries when system went
1016 * idle after a busy period.
1018 * The heuristics below are supposed to balance conflicting goals:
1020 * 1. Minimize time until we notice a stale entry
1021 * 2. Maximize scan intervals to not waste cycles
1023 * Normally, expire ratio will be close to 0.
1025 * As soon as a sizeable fraction of the entries have expired
1026 * increase scan frequency.
1028 ratio
= scanned
? expired_count
* 100 / scanned
: 0;
1029 if (ratio
> GC_EVICT_RATIO
) {
1030 gc_work
->next_gc_run
= min_interval
;
1032 unsigned int max
= GC_MAX_SCAN_JIFFIES
/ GC_MAX_BUCKETS_DIV
;
1034 BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES
/ GC_MAX_BUCKETS_DIV
) == 0);
1036 gc_work
->next_gc_run
+= min_interval
;
1037 if (gc_work
->next_gc_run
> max
)
1038 gc_work
->next_gc_run
= max
;
1041 next_run
= gc_work
->next_gc_run
;
1042 gc_work
->last_bucket
= i
;
1043 queue_delayed_work(system_long_wq
, &gc_work
->dwork
, next_run
);
1046 static void conntrack_gc_work_init(struct conntrack_gc_work
*gc_work
)
1048 INIT_DELAYED_WORK(&gc_work
->dwork
, gc_worker
);
1049 gc_work
->next_gc_run
= HZ
;
1050 gc_work
->exiting
= false;
1053 static struct nf_conn
*
1054 __nf_conntrack_alloc(struct net
*net
,
1055 const struct nf_conntrack_zone
*zone
,
1056 const struct nf_conntrack_tuple
*orig
,
1057 const struct nf_conntrack_tuple
*repl
,
1058 gfp_t gfp
, u32 hash
)
1062 /* We don't want any race condition at early drop stage */
1063 atomic_inc(&net
->ct
.count
);
1065 if (nf_conntrack_max
&&
1066 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
1067 if (!early_drop(net
, hash
)) {
1068 atomic_dec(&net
->ct
.count
);
1069 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
1070 return ERR_PTR(-ENOMEM
);
1075 * Do not use kmem_cache_zalloc(), as this cache uses
1076 * SLAB_DESTROY_BY_RCU.
1078 ct
= kmem_cache_alloc(nf_conntrack_cachep
, gfp
);
1082 spin_lock_init(&ct
->lock
);
1083 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
1084 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
1085 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
1086 /* save hash for reusing when confirming */
1087 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
1089 write_pnet(&ct
->ct_net
, net
);
1090 memset(&ct
->__nfct_init_offset
[0], 0,
1091 offsetof(struct nf_conn
, proto
) -
1092 offsetof(struct nf_conn
, __nfct_init_offset
[0]));
1094 nf_ct_zone_add(ct
, zone
);
1096 /* Because we use RCU lookups, we set ct_general.use to zero before
1097 * this is inserted in any list.
1099 atomic_set(&ct
->ct_general
.use
, 0);
1102 atomic_dec(&net
->ct
.count
);
1103 return ERR_PTR(-ENOMEM
);
1106 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
1107 const struct nf_conntrack_zone
*zone
,
1108 const struct nf_conntrack_tuple
*orig
,
1109 const struct nf_conntrack_tuple
*repl
,
1112 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
1114 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
1116 void nf_conntrack_free(struct nf_conn
*ct
)
1118 struct net
*net
= nf_ct_net(ct
);
1120 /* A freed object has refcnt == 0, that's
1121 * the golden rule for SLAB_DESTROY_BY_RCU
1123 NF_CT_ASSERT(atomic_read(&ct
->ct_general
.use
) == 0);
1125 nf_ct_ext_destroy(ct
);
1127 kmem_cache_free(nf_conntrack_cachep
, ct
);
1128 smp_mb__before_atomic();
1129 atomic_dec(&net
->ct
.count
);
1131 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
1134 /* Allocate a new conntrack: we return -ENOMEM if classification
1135 failed due to stress. Otherwise it really is unclassifiable. */
1136 static struct nf_conntrack_tuple_hash
*
1137 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
1138 const struct nf_conntrack_tuple
*tuple
,
1139 struct nf_conntrack_l3proto
*l3proto
,
1140 struct nf_conntrack_l4proto
*l4proto
,
1141 struct sk_buff
*skb
,
1142 unsigned int dataoff
, u32 hash
)
1145 struct nf_conn_help
*help
;
1146 struct nf_conntrack_tuple repl_tuple
;
1147 struct nf_conntrack_ecache
*ecache
;
1148 struct nf_conntrack_expect
*exp
= NULL
;
1149 const struct nf_conntrack_zone
*zone
;
1150 struct nf_conn_timeout
*timeout_ext
;
1151 struct nf_conntrack_zone tmp
;
1152 unsigned int *timeouts
;
1154 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
1155 pr_debug("Can't invert tuple.\n");
1159 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1160 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
1163 return (struct nf_conntrack_tuple_hash
*)ct
;
1165 if (!nf_ct_add_synproxy(ct
, tmpl
)) {
1166 nf_conntrack_free(ct
);
1167 return ERR_PTR(-ENOMEM
);
1170 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
1172 timeouts
= nf_ct_timeout_data(timeout_ext
);
1173 if (unlikely(!timeouts
))
1174 timeouts
= l4proto
->get_timeouts(net
);
1176 timeouts
= l4proto
->get_timeouts(net
);
1179 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
1180 nf_conntrack_free(ct
);
1181 pr_debug("can't track with proto module\n");
1186 nf_ct_timeout_ext_add(ct
, rcu_dereference(timeout_ext
->timeout
),
1189 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
1190 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
1191 nf_ct_labels_ext_add(ct
);
1193 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
1194 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
1195 ecache
? ecache
->expmask
: 0,
1199 if (net
->ct
.expect_count
) {
1200 spin_lock(&nf_conntrack_expect_lock
);
1201 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
1203 pr_debug("expectation arrives ct=%p exp=%p\n",
1205 /* Welcome, Mr. Bond. We've been expecting you... */
1206 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
1207 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1208 ct
->master
= exp
->master
;
1210 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
1213 rcu_assign_pointer(help
->helper
, exp
->helper
);
1216 #ifdef CONFIG_NF_CONNTRACK_MARK
1217 ct
->mark
= exp
->master
->mark
;
1219 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1220 ct
->secmark
= exp
->master
->secmark
;
1222 NF_CT_STAT_INC(net
, expect_new
);
1224 spin_unlock(&nf_conntrack_expect_lock
);
1227 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
1229 /* Now it is inserted into the unconfirmed list, bump refcount */
1230 nf_conntrack_get(&ct
->ct_general
);
1231 nf_ct_add_to_unconfirmed_list(ct
);
1237 exp
->expectfn(ct
, exp
);
1238 nf_ct_expect_put(exp
);
1241 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
1244 /* On success, returns conntrack ptr, sets skb->_nfct | ctinfo */
1245 static inline struct nf_conn
*
1246 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
1247 struct sk_buff
*skb
,
1248 unsigned int dataoff
,
1251 struct nf_conntrack_l3proto
*l3proto
,
1252 struct nf_conntrack_l4proto
*l4proto
,
1254 enum ip_conntrack_info
*ctinfo
)
1256 const struct nf_conntrack_zone
*zone
;
1257 struct nf_conntrack_tuple tuple
;
1258 struct nf_conntrack_tuple_hash
*h
;
1259 struct nf_conntrack_zone tmp
;
1263 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
1264 dataoff
, l3num
, protonum
, net
, &tuple
, l3proto
,
1266 pr_debug("Can't get tuple\n");
1270 /* look for tuple match */
1271 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1272 hash
= hash_conntrack_raw(&tuple
, net
);
1273 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
1275 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
1276 skb
, dataoff
, hash
);
1282 ct
= nf_ct_tuplehash_to_ctrack(h
);
1284 /* It exists; we have (non-exclusive) reference. */
1285 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
1286 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
1287 /* Please set reply bit if this packet OK */
1290 /* Once we've had two way comms, always ESTABLISHED. */
1291 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
1292 pr_debug("normal packet for %p\n", ct
);
1293 *ctinfo
= IP_CT_ESTABLISHED
;
1294 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
1295 pr_debug("related packet for %p\n", ct
);
1296 *ctinfo
= IP_CT_RELATED
;
1298 pr_debug("new packet for %p\n", ct
);
1299 *ctinfo
= IP_CT_NEW
;
1303 nf_ct_set(skb
, ct
, *ctinfo
);
1308 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
1309 struct sk_buff
*skb
)
1311 struct nf_conn
*ct
, *tmpl
;
1312 enum ip_conntrack_info ctinfo
;
1313 struct nf_conntrack_l3proto
*l3proto
;
1314 struct nf_conntrack_l4proto
*l4proto
;
1315 unsigned int *timeouts
;
1316 unsigned int dataoff
;
1321 tmpl
= nf_ct_get(skb
, &ctinfo
);
1323 /* Previously seen (loopback or untracked)? Ignore. */
1324 if (!nf_ct_is_template(tmpl
)) {
1325 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
1331 /* rcu_read_lock()ed by nf_hook_thresh */
1332 l3proto
= __nf_ct_l3proto_find(pf
);
1333 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
1334 &dataoff
, &protonum
);
1336 pr_debug("not prepared to track yet or error occurred\n");
1337 NF_CT_STAT_INC_ATOMIC(net
, error
);
1338 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1343 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
1345 /* It may be an special packet, error, unclean...
1346 * inverse of the return code tells to the netfilter
1347 * core what to do with the packet. */
1348 if (l4proto
->error
!= NULL
) {
1349 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, pf
, hooknum
);
1351 NF_CT_STAT_INC_ATOMIC(net
, error
);
1352 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1356 /* ICMP[v6] protocol trackers may assign one conntrack. */
1361 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
1362 l3proto
, l4proto
, &set_reply
, &ctinfo
);
1364 /* Not valid part of a connection */
1365 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1371 /* Too stressed to deal. */
1372 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1377 NF_CT_ASSERT(skb_nfct(skb
));
1379 /* Decide what timeout policy we want to apply to this flow. */
1380 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1382 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1384 /* Invalid: inverse of the return code tells
1385 * the netfilter core what to do */
1386 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1387 nf_conntrack_put(&ct
->ct_general
);
1389 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1390 if (ret
== -NF_DROP
)
1391 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1392 /* Special case: TCP tracker reports an attempt to reopen a
1393 * closed/aborted connection. We have to go back and create a
1396 if (ret
== -NF_REPEAT
)
1402 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1403 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1410 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1412 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1413 const struct nf_conntrack_tuple
*orig
)
1418 ret
= nf_ct_invert_tuple(inverse
, orig
,
1419 __nf_ct_l3proto_find(orig
->src
.l3num
),
1420 __nf_ct_l4proto_find(orig
->src
.l3num
,
1421 orig
->dst
.protonum
));
1425 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1427 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1428 implicitly racy: see __nf_conntrack_confirm */
1429 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1430 const struct nf_conntrack_tuple
*newreply
)
1432 struct nf_conn_help
*help
= nfct_help(ct
);
1434 /* Should be unconfirmed, so not in hash table yet */
1435 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1437 pr_debug("Altering reply tuple of %p to ", ct
);
1438 nf_ct_dump_tuple(newreply
);
1440 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1441 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1445 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1448 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1450 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1451 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1452 enum ip_conntrack_info ctinfo
,
1453 const struct sk_buff
*skb
,
1454 unsigned long extra_jiffies
,
1459 /* Only update if this is not a fixed timeout */
1460 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1463 /* If not in hash table, timer will not be active yet */
1464 if (nf_ct_is_confirmed(ct
))
1465 extra_jiffies
+= nfct_time_stamp
;
1467 ct
->timeout
= extra_jiffies
;
1470 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1472 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1474 bool nf_ct_kill_acct(struct nf_conn
*ct
,
1475 enum ip_conntrack_info ctinfo
,
1476 const struct sk_buff
*skb
)
1478 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1480 return nf_ct_delete(ct
, 0, 0);
1482 EXPORT_SYMBOL_GPL(nf_ct_kill_acct
);
1484 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1486 #include <linux/netfilter/nfnetlink.h>
1487 #include <linux/netfilter/nfnetlink_conntrack.h>
1488 #include <linux/mutex.h>
1490 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1491 * in ip_conntrack_core, since we don't want the protocols to autoload
1492 * or depend on ctnetlink */
1493 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1494 const struct nf_conntrack_tuple
*tuple
)
1496 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1497 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1498 goto nla_put_failure
;
1504 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1506 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1507 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1508 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1510 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1512 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1513 struct nf_conntrack_tuple
*t
)
1515 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1518 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1519 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1523 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1525 int nf_ct_port_nlattr_tuple_size(void)
1527 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1529 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1532 /* Used by ipt_REJECT and ip6t_REJECT. */
1533 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1536 enum ip_conntrack_info ctinfo
;
1538 /* This ICMP is in reverse direction to the packet which caused it */
1539 ct
= nf_ct_get(skb
, &ctinfo
);
1540 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1541 ctinfo
= IP_CT_RELATED_REPLY
;
1543 ctinfo
= IP_CT_RELATED
;
1545 /* Attach to new skbuff, and increment count */
1546 nf_ct_set(nskb
, ct
, ctinfo
);
1547 nf_conntrack_get(skb_nfct(nskb
));
1550 /* Bring out ya dead! */
1551 static struct nf_conn
*
1552 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1553 void *data
, unsigned int *bucket
)
1555 struct nf_conntrack_tuple_hash
*h
;
1557 struct hlist_nulls_node
*n
;
1561 for (; *bucket
< nf_conntrack_htable_size
; (*bucket
)++) {
1562 lockp
= &nf_conntrack_locks
[*bucket
% CONNTRACK_LOCKS
];
1564 nf_conntrack_lock(lockp
);
1565 if (*bucket
< nf_conntrack_htable_size
) {
1566 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[*bucket
], hnnode
) {
1567 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1569 ct
= nf_ct_tuplehash_to_ctrack(h
);
1570 if (net_eq(nf_ct_net(ct
), net
) &&
1580 for_each_possible_cpu(cpu
) {
1581 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1583 spin_lock_bh(&pcpu
->lock
);
1584 hlist_nulls_for_each_entry(h
, n
, &pcpu
->unconfirmed
, hnnode
) {
1585 ct
= nf_ct_tuplehash_to_ctrack(h
);
1587 set_bit(IPS_DYING_BIT
, &ct
->status
);
1589 spin_unlock_bh(&pcpu
->lock
);
1594 atomic_inc(&ct
->ct_general
.use
);
1600 void nf_ct_iterate_cleanup(struct net
*net
,
1601 int (*iter
)(struct nf_conn
*i
, void *data
),
1602 void *data
, u32 portid
, int report
)
1605 unsigned int bucket
= 0;
1609 if (atomic_read(&net
->ct
.count
) == 0)
1612 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1613 /* Time to push up daises... */
1615 nf_ct_delete(ct
, portid
, report
);
1620 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1622 static int kill_all(struct nf_conn
*i
, void *data
)
1627 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1629 if (is_vmalloc_addr(hash
))
1632 free_pages((unsigned long)hash
,
1633 get_order(sizeof(struct hlist_head
) * size
));
1635 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1637 static int untrack_refs(void)
1641 for_each_possible_cpu(cpu
) {
1642 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1644 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1649 void nf_conntrack_cleanup_start(void)
1651 conntrack_gc_work
.exiting
= true;
1652 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1655 void nf_conntrack_cleanup_end(void)
1657 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1658 while (untrack_refs() > 0)
1661 cancel_delayed_work_sync(&conntrack_gc_work
.dwork
);
1662 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1664 nf_conntrack_proto_fini();
1665 nf_conntrack_seqadj_fini();
1666 nf_conntrack_labels_fini();
1667 nf_conntrack_helper_fini();
1668 nf_conntrack_timeout_fini();
1669 nf_conntrack_ecache_fini();
1670 nf_conntrack_tstamp_fini();
1671 nf_conntrack_acct_fini();
1672 nf_conntrack_expect_fini();
1674 kmem_cache_destroy(nf_conntrack_cachep
);
1678 * Mishearing the voices in his head, our hero wonders how he's
1679 * supposed to kill the mall.
1681 void nf_conntrack_cleanup_net(struct net
*net
)
1685 list_add(&net
->exit_list
, &single
);
1686 nf_conntrack_cleanup_net_list(&single
);
1689 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1695 * This makes sure all current packets have passed through
1696 * netfilter framework. Roll on, two-stage module
1702 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1703 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1704 if (atomic_read(&net
->ct
.count
) != 0)
1709 goto i_see_dead_people
;
1712 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1713 nf_conntrack_proto_pernet_fini(net
);
1714 nf_conntrack_helper_pernet_fini(net
);
1715 nf_conntrack_ecache_pernet_fini(net
);
1716 nf_conntrack_tstamp_pernet_fini(net
);
1717 nf_conntrack_acct_pernet_fini(net
);
1718 nf_conntrack_expect_pernet_fini(net
);
1719 free_percpu(net
->ct
.stat
);
1720 free_percpu(net
->ct
.pcpu_lists
);
1724 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1726 struct hlist_nulls_head
*hash
;
1727 unsigned int nr_slots
, i
;
1730 if (*sizep
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1733 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1734 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1736 if (nr_slots
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1739 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1740 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1746 for (i
= 0; i
< nr_slots
; i
++)
1747 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1751 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1753 int nf_conntrack_hash_resize(unsigned int hashsize
)
1756 unsigned int old_size
;
1757 struct hlist_nulls_head
*hash
, *old_hash
;
1758 struct nf_conntrack_tuple_hash
*h
;
1764 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1768 old_size
= nf_conntrack_htable_size
;
1769 if (old_size
== hashsize
) {
1770 nf_ct_free_hashtable(hash
, hashsize
);
1775 nf_conntrack_all_lock();
1776 write_seqcount_begin(&nf_conntrack_generation
);
1778 /* Lookups in the old hash might happen in parallel, which means we
1779 * might get false negatives during connection lookup. New connections
1780 * created because of a false negative won't make it into the hash
1781 * though since that required taking the locks.
1784 for (i
= 0; i
< nf_conntrack_htable_size
; i
++) {
1785 while (!hlist_nulls_empty(&nf_conntrack_hash
[i
])) {
1786 h
= hlist_nulls_entry(nf_conntrack_hash
[i
].first
,
1787 struct nf_conntrack_tuple_hash
, hnnode
);
1788 ct
= nf_ct_tuplehash_to_ctrack(h
);
1789 hlist_nulls_del_rcu(&h
->hnnode
);
1790 bucket
= __hash_conntrack(nf_ct_net(ct
),
1791 &h
->tuple
, hashsize
);
1792 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1795 old_size
= nf_conntrack_htable_size
;
1796 old_hash
= nf_conntrack_hash
;
1798 nf_conntrack_hash
= hash
;
1799 nf_conntrack_htable_size
= hashsize
;
1801 write_seqcount_end(&nf_conntrack_generation
);
1802 nf_conntrack_all_unlock();
1806 nf_ct_free_hashtable(old_hash
, old_size
);
1810 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1812 unsigned int hashsize
;
1815 if (current
->nsproxy
->net_ns
!= &init_net
)
1818 /* On boot, we can set this without any fancy locking. */
1819 if (!nf_conntrack_htable_size
)
1820 return param_set_uint(val
, kp
);
1822 rc
= kstrtouint(val
, 0, &hashsize
);
1826 return nf_conntrack_hash_resize(hashsize
);
1828 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1830 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1831 &nf_conntrack_htable_size
, 0600);
1833 void nf_ct_untracked_status_or(unsigned long bits
)
1837 for_each_possible_cpu(cpu
)
1838 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1840 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1842 int nf_conntrack_init_start(void)
1848 seqcount_init(&nf_conntrack_generation
);
1850 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
1851 spin_lock_init(&nf_conntrack_locks
[i
]);
1853 if (!nf_conntrack_htable_size
) {
1854 /* Idea from tcp.c: use 1/16384 of memory.
1855 * On i386: 32MB machine has 512 buckets.
1856 * >= 1GB machines have 16384 buckets.
1857 * >= 4GB machines have 65536 buckets.
1859 nf_conntrack_htable_size
1860 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1861 / sizeof(struct hlist_head
));
1862 if (totalram_pages
> (4 * (1024 * 1024 * 1024 / PAGE_SIZE
)))
1863 nf_conntrack_htable_size
= 65536;
1864 else if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1865 nf_conntrack_htable_size
= 16384;
1866 if (nf_conntrack_htable_size
< 32)
1867 nf_conntrack_htable_size
= 32;
1869 /* Use a max. factor of four by default to get the same max as
1870 * with the old struct list_heads. When a table size is given
1871 * we use the old value of 8 to avoid reducing the max.
1876 nf_conntrack_hash
= nf_ct_alloc_hashtable(&nf_conntrack_htable_size
, 1);
1877 if (!nf_conntrack_hash
)
1880 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1882 nf_conntrack_cachep
= kmem_cache_create("nf_conntrack",
1883 sizeof(struct nf_conn
),
1885 SLAB_DESTROY_BY_RCU
| SLAB_HWCACHE_ALIGN
, NULL
);
1886 if (!nf_conntrack_cachep
)
1889 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1890 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1893 ret
= nf_conntrack_expect_init();
1897 ret
= nf_conntrack_acct_init();
1901 ret
= nf_conntrack_tstamp_init();
1905 ret
= nf_conntrack_ecache_init();
1909 ret
= nf_conntrack_timeout_init();
1913 ret
= nf_conntrack_helper_init();
1917 ret
= nf_conntrack_labels_init();
1921 ret
= nf_conntrack_seqadj_init();
1925 ret
= nf_conntrack_proto_init();
1929 /* Set up fake conntrack: to never be deleted, not in any hashes */
1930 for_each_possible_cpu(cpu
) {
1931 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1932 write_pnet(&ct
->ct_net
, &init_net
);
1933 atomic_set(&ct
->ct_general
.use
, 1);
1935 /* - and look it like as a confirmed connection */
1936 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1938 conntrack_gc_work_init(&conntrack_gc_work
);
1939 queue_delayed_work(system_long_wq
, &conntrack_gc_work
.dwork
, HZ
);
1944 nf_conntrack_seqadj_fini();
1946 nf_conntrack_labels_fini();
1948 nf_conntrack_helper_fini();
1950 nf_conntrack_timeout_fini();
1952 nf_conntrack_ecache_fini();
1954 nf_conntrack_tstamp_fini();
1956 nf_conntrack_acct_fini();
1958 nf_conntrack_expect_fini();
1960 kmem_cache_destroy(nf_conntrack_cachep
);
1962 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1966 void nf_conntrack_init_end(void)
1968 /* For use by REJECT target */
1969 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1970 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1974 * We need to use special "null" values, not used in hash table
1976 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1977 #define DYING_NULLS_VAL ((1<<30)+1)
1978 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1980 int nf_conntrack_init_net(struct net
*net
)
1985 atomic_set(&net
->ct
.count
, 0);
1987 net
->ct
.pcpu_lists
= alloc_percpu(struct ct_pcpu
);
1988 if (!net
->ct
.pcpu_lists
)
1991 for_each_possible_cpu(cpu
) {
1992 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1994 spin_lock_init(&pcpu
->lock
);
1995 INIT_HLIST_NULLS_HEAD(&pcpu
->unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1996 INIT_HLIST_NULLS_HEAD(&pcpu
->dying
, DYING_NULLS_VAL
);
1999 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
2001 goto err_pcpu_lists
;
2003 ret
= nf_conntrack_expect_pernet_init(net
);
2006 ret
= nf_conntrack_acct_pernet_init(net
);
2009 ret
= nf_conntrack_tstamp_pernet_init(net
);
2012 ret
= nf_conntrack_ecache_pernet_init(net
);
2015 ret
= nf_conntrack_helper_pernet_init(net
);
2018 ret
= nf_conntrack_proto_pernet_init(net
);
2024 nf_conntrack_helper_pernet_fini(net
);
2026 nf_conntrack_ecache_pernet_fini(net
);
2028 nf_conntrack_tstamp_pernet_fini(net
);
2030 nf_conntrack_acct_pernet_fini(net
);
2032 nf_conntrack_expect_pernet_fini(net
);
2034 free_percpu(net
->ct
.stat
);
2036 free_percpu(net
->ct
.pcpu_lists
);