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
;
81 static __read_mostly
struct kmem_cache
*nf_conntrack_cachep
;
82 static __read_mostly spinlock_t nf_conntrack_locks_all_lock
;
83 static __read_mostly
DEFINE_SPINLOCK(nf_conntrack_locks_all_lock
);
84 static __read_mostly
bool nf_conntrack_locks_all
;
86 #define GC_MAX_BUCKETS_DIV 64u
87 #define GC_MAX_BUCKETS 8192u
88 #define GC_INTERVAL (5 * HZ)
89 #define GC_MAX_EVICTS 256u
91 static struct conntrack_gc_work conntrack_gc_work
;
93 void nf_conntrack_lock(spinlock_t
*lock
) __acquires(lock
)
96 while (unlikely(nf_conntrack_locks_all
)) {
100 * Order the 'nf_conntrack_locks_all' load vs. the
101 * spin_unlock_wait() loads below, to ensure
102 * that 'nf_conntrack_locks_all_lock' is indeed held:
104 smp_rmb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
105 spin_unlock_wait(&nf_conntrack_locks_all_lock
);
109 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
111 static void nf_conntrack_double_unlock(unsigned int h1
, unsigned int h2
)
113 h1
%= CONNTRACK_LOCKS
;
114 h2
%= CONNTRACK_LOCKS
;
115 spin_unlock(&nf_conntrack_locks
[h1
]);
117 spin_unlock(&nf_conntrack_locks
[h2
]);
120 /* return true if we need to recompute hashes (in case hash table was resized) */
121 static bool nf_conntrack_double_lock(struct net
*net
, unsigned int h1
,
122 unsigned int h2
, unsigned int sequence
)
124 h1
%= CONNTRACK_LOCKS
;
125 h2
%= CONNTRACK_LOCKS
;
127 nf_conntrack_lock(&nf_conntrack_locks
[h1
]);
129 spin_lock_nested(&nf_conntrack_locks
[h2
],
130 SINGLE_DEPTH_NESTING
);
132 nf_conntrack_lock(&nf_conntrack_locks
[h2
]);
133 spin_lock_nested(&nf_conntrack_locks
[h1
],
134 SINGLE_DEPTH_NESTING
);
136 if (read_seqcount_retry(&nf_conntrack_generation
, sequence
)) {
137 nf_conntrack_double_unlock(h1
, h2
);
143 static void nf_conntrack_all_lock(void)
147 spin_lock(&nf_conntrack_locks_all_lock
);
148 nf_conntrack_locks_all
= true;
151 * Order the above store of 'nf_conntrack_locks_all' against
152 * the spin_unlock_wait() loads below, such that if
153 * nf_conntrack_lock() observes 'nf_conntrack_locks_all'
154 * we must observe nf_conntrack_locks[] held:
156 smp_mb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
158 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++) {
159 spin_unlock_wait(&nf_conntrack_locks
[i
]);
163 static void nf_conntrack_all_unlock(void)
166 * All prior stores must be complete before we clear
167 * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
168 * might observe the false value but not the entire
171 smp_store_release(&nf_conntrack_locks_all
, false);
172 spin_unlock(&nf_conntrack_locks_all_lock
);
175 unsigned int nf_conntrack_htable_size __read_mostly
;
176 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
178 unsigned int nf_conntrack_max __read_mostly
;
179 seqcount_t nf_conntrack_generation __read_mostly
;
181 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
182 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
184 static unsigned int nf_conntrack_hash_rnd __read_mostly
;
186 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
,
187 const struct net
*net
)
192 get_random_once(&nf_conntrack_hash_rnd
, sizeof(nf_conntrack_hash_rnd
));
194 /* The direction must be ignored, so we hash everything up to the
195 * destination ports (which is a multiple of 4) and treat the last
196 * three bytes manually.
198 seed
= nf_conntrack_hash_rnd
^ net_hash_mix(net
);
199 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
200 return jhash2((u32
*)tuple
, n
, seed
^
201 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
202 tuple
->dst
.protonum
));
205 static u32
scale_hash(u32 hash
)
207 return reciprocal_scale(hash
, nf_conntrack_htable_size
);
210 static u32
__hash_conntrack(const struct net
*net
,
211 const struct nf_conntrack_tuple
*tuple
,
214 return reciprocal_scale(hash_conntrack_raw(tuple
, net
), size
);
217 static u32
hash_conntrack(const struct net
*net
,
218 const struct nf_conntrack_tuple
*tuple
)
220 return scale_hash(hash_conntrack_raw(tuple
, net
));
224 nf_ct_get_tuple(const struct sk_buff
*skb
,
226 unsigned int dataoff
,
230 struct nf_conntrack_tuple
*tuple
,
231 const struct nf_conntrack_l3proto
*l3proto
,
232 const struct nf_conntrack_l4proto
*l4proto
)
234 memset(tuple
, 0, sizeof(*tuple
));
236 tuple
->src
.l3num
= l3num
;
237 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
240 tuple
->dst
.protonum
= protonum
;
241 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
243 return l4proto
->pkt_to_tuple(skb
, dataoff
, net
, tuple
);
245 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
247 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
249 struct net
*net
, struct nf_conntrack_tuple
*tuple
)
251 struct nf_conntrack_l3proto
*l3proto
;
252 struct nf_conntrack_l4proto
*l4proto
;
253 unsigned int protoff
;
259 l3proto
= __nf_ct_l3proto_find(l3num
);
260 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
261 if (ret
!= NF_ACCEPT
) {
266 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
268 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, net
, tuple
,
274 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
277 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
278 const struct nf_conntrack_tuple
*orig
,
279 const struct nf_conntrack_l3proto
*l3proto
,
280 const struct nf_conntrack_l4proto
*l4proto
)
282 memset(inverse
, 0, sizeof(*inverse
));
284 inverse
->src
.l3num
= orig
->src
.l3num
;
285 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
288 inverse
->dst
.dir
= !orig
->dst
.dir
;
290 inverse
->dst
.protonum
= orig
->dst
.protonum
;
291 return l4proto
->invert_tuple(inverse
, orig
);
293 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
296 clean_from_lists(struct nf_conn
*ct
)
298 pr_debug("clean_from_lists(%p)\n", ct
);
299 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
300 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
302 /* Destroy all pending expectations */
303 nf_ct_remove_expectations(ct
);
306 /* must be called with local_bh_disable */
307 static void nf_ct_add_to_dying_list(struct nf_conn
*ct
)
309 struct ct_pcpu
*pcpu
;
311 /* add this conntrack to the (per cpu) dying list */
312 ct
->cpu
= smp_processor_id();
313 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
315 spin_lock(&pcpu
->lock
);
316 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
318 spin_unlock(&pcpu
->lock
);
321 /* must be called with local_bh_disable */
322 static void nf_ct_add_to_unconfirmed_list(struct nf_conn
*ct
)
324 struct ct_pcpu
*pcpu
;
326 /* add this conntrack to the (per cpu) unconfirmed list */
327 ct
->cpu
= smp_processor_id();
328 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
330 spin_lock(&pcpu
->lock
);
331 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
333 spin_unlock(&pcpu
->lock
);
336 /* must be called with local_bh_disable */
337 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn
*ct
)
339 struct ct_pcpu
*pcpu
;
341 /* We overload first tuple to link into unconfirmed or dying list.*/
342 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
344 spin_lock(&pcpu
->lock
);
345 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
346 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
347 spin_unlock(&pcpu
->lock
);
350 /* Released via destroy_conntrack() */
351 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
352 const struct nf_conntrack_zone
*zone
,
355 struct nf_conn
*tmpl
;
357 tmpl
= kzalloc(sizeof(*tmpl
), flags
);
361 tmpl
->status
= IPS_TEMPLATE
;
362 write_pnet(&tmpl
->ct_net
, net
);
363 nf_ct_zone_add(tmpl
, zone
);
364 atomic_set(&tmpl
->ct_general
.use
, 0);
368 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc
);
370 void nf_ct_tmpl_free(struct nf_conn
*tmpl
)
372 nf_ct_ext_destroy(tmpl
);
373 nf_ct_ext_free(tmpl
);
376 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free
);
379 destroy_conntrack(struct nf_conntrack
*nfct
)
381 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
382 struct net
*net
= nf_ct_net(ct
);
383 struct nf_conntrack_l4proto
*l4proto
;
385 pr_debug("destroy_conntrack(%p)\n", ct
);
386 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
388 if (unlikely(nf_ct_is_template(ct
))) {
393 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
394 if (l4proto
->destroy
)
395 l4proto
->destroy(ct
);
400 /* Expectations will have been removed in clean_from_lists,
401 * except TFTP can create an expectation on the first packet,
402 * before connection is in the list, so we need to clean here,
405 nf_ct_remove_expectations(ct
);
407 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
409 NF_CT_STAT_INC(net
, delete);
413 nf_ct_put(ct
->master
);
415 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
416 nf_conntrack_free(ct
);
419 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
421 struct net
*net
= nf_ct_net(ct
);
422 unsigned int hash
, reply_hash
;
423 unsigned int sequence
;
425 nf_ct_helper_destroy(ct
);
429 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
430 hash
= hash_conntrack(net
,
431 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
432 reply_hash
= hash_conntrack(net
,
433 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
434 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
436 clean_from_lists(ct
);
437 nf_conntrack_double_unlock(hash
, reply_hash
);
439 nf_ct_add_to_dying_list(ct
);
441 NF_CT_STAT_INC(net
, delete_list
);
445 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
447 struct nf_conn_tstamp
*tstamp
;
449 if (test_and_set_bit(IPS_DYING_BIT
, &ct
->status
))
452 tstamp
= nf_conn_tstamp_find(ct
);
453 if (tstamp
&& tstamp
->stop
== 0)
454 tstamp
->stop
= ktime_get_real_ns();
456 if (nf_conntrack_event_report(IPCT_DESTROY
, ct
,
457 portid
, report
) < 0) {
458 /* destroy event was not delivered. nf_ct_put will
459 * be done by event cache worker on redelivery.
461 nf_ct_delete_from_lists(ct
);
462 nf_conntrack_ecache_delayed_work(nf_ct_net(ct
));
466 nf_conntrack_ecache_work(nf_ct_net(ct
));
467 nf_ct_delete_from_lists(ct
);
471 EXPORT_SYMBOL_GPL(nf_ct_delete
);
474 nf_ct_key_equal(struct nf_conntrack_tuple_hash
*h
,
475 const struct nf_conntrack_tuple
*tuple
,
476 const struct nf_conntrack_zone
*zone
,
477 const struct net
*net
)
479 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
481 /* A conntrack can be recreated with the equal tuple,
482 * so we need to check that the conntrack is confirmed
484 return nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
485 nf_ct_zone_equal(ct
, zone
, NF_CT_DIRECTION(h
)) &&
486 nf_ct_is_confirmed(ct
) &&
487 net_eq(net
, nf_ct_net(ct
));
490 /* caller must hold rcu readlock and none of the nf_conntrack_locks */
491 static void nf_ct_gc_expired(struct nf_conn
*ct
)
493 if (!atomic_inc_not_zero(&ct
->ct_general
.use
))
496 if (nf_ct_should_gc(ct
))
504 * - Caller must take a reference on returned object
505 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
507 static struct nf_conntrack_tuple_hash
*
508 ____nf_conntrack_find(struct net
*net
, const struct nf_conntrack_zone
*zone
,
509 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
511 struct nf_conntrack_tuple_hash
*h
;
512 struct hlist_nulls_head
*ct_hash
;
513 struct hlist_nulls_node
*n
;
514 unsigned int bucket
, hsize
;
517 nf_conntrack_get_ht(&ct_hash
, &hsize
);
518 bucket
= reciprocal_scale(hash
, hsize
);
520 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[bucket
], hnnode
) {
523 ct
= nf_ct_tuplehash_to_ctrack(h
);
524 if (nf_ct_is_expired(ct
)) {
525 nf_ct_gc_expired(ct
);
529 if (nf_ct_is_dying(ct
))
532 if (nf_ct_key_equal(h
, tuple
, zone
, net
)) {
533 NF_CT_STAT_INC_ATOMIC(net
, found
);
536 NF_CT_STAT_INC_ATOMIC(net
, searched
);
539 * if the nulls value we got at the end of this lookup is
540 * not the expected one, we must restart lookup.
541 * We probably met an item that was moved to another chain.
543 if (get_nulls_value(n
) != bucket
) {
544 NF_CT_STAT_INC_ATOMIC(net
, search_restart
);
551 /* Find a connection corresponding to a tuple. */
552 static struct nf_conntrack_tuple_hash
*
553 __nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
554 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
556 struct nf_conntrack_tuple_hash
*h
;
561 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
563 ct
= nf_ct_tuplehash_to_ctrack(h
);
564 if (unlikely(nf_ct_is_dying(ct
) ||
565 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
568 if (unlikely(!nf_ct_key_equal(h
, tuple
, zone
, net
))) {
579 struct nf_conntrack_tuple_hash
*
580 nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
581 const struct nf_conntrack_tuple
*tuple
)
583 return __nf_conntrack_find_get(net
, zone
, tuple
,
584 hash_conntrack_raw(tuple
, net
));
586 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
588 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
590 unsigned int reply_hash
)
592 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
593 &nf_conntrack_hash
[hash
]);
594 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
595 &nf_conntrack_hash
[reply_hash
]);
599 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
601 const struct nf_conntrack_zone
*zone
;
602 struct net
*net
= nf_ct_net(ct
);
603 unsigned int hash
, reply_hash
;
604 struct nf_conntrack_tuple_hash
*h
;
605 struct hlist_nulls_node
*n
;
606 unsigned int sequence
;
608 zone
= nf_ct_zone(ct
);
612 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
613 hash
= hash_conntrack(net
,
614 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
615 reply_hash
= hash_conntrack(net
,
616 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
617 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
619 /* See if there's one in the list already, including reverse */
620 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
621 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
625 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
626 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
631 /* The caller holds a reference to this object */
632 atomic_set(&ct
->ct_general
.use
, 2);
633 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
634 nf_conntrack_double_unlock(hash
, reply_hash
);
635 NF_CT_STAT_INC(net
, insert
);
640 nf_conntrack_double_unlock(hash
, reply_hash
);
641 NF_CT_STAT_INC(net
, insert_failed
);
645 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
647 static inline void nf_ct_acct_update(struct nf_conn
*ct
,
648 enum ip_conntrack_info ctinfo
,
651 struct nf_conn_acct
*acct
;
653 acct
= nf_conn_acct_find(ct
);
655 struct nf_conn_counter
*counter
= acct
->counter
;
657 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
658 atomic64_add(len
, &counter
[CTINFO2DIR(ctinfo
)].bytes
);
662 static void nf_ct_acct_merge(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
663 const struct nf_conn
*loser_ct
)
665 struct nf_conn_acct
*acct
;
667 acct
= nf_conn_acct_find(loser_ct
);
669 struct nf_conn_counter
*counter
= acct
->counter
;
672 /* u32 should be fine since we must have seen one packet. */
673 bytes
= atomic64_read(&counter
[CTINFO2DIR(ctinfo
)].bytes
);
674 nf_ct_acct_update(ct
, ctinfo
, bytes
);
678 /* Resolve race on insertion if this protocol allows this. */
679 static int nf_ct_resolve_clash(struct net
*net
, struct sk_buff
*skb
,
680 enum ip_conntrack_info ctinfo
,
681 struct nf_conntrack_tuple_hash
*h
)
683 /* This is the conntrack entry already in hashes that won race. */
684 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
685 struct nf_conntrack_l4proto
*l4proto
;
687 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
688 if (l4proto
->allow_clash
&&
690 !nf_ct_is_dying(ct
) &&
691 atomic_inc_not_zero(&ct
->ct_general
.use
)) {
692 nf_ct_acct_merge(ct
, ctinfo
, (struct nf_conn
*)skb
->nfct
);
693 nf_conntrack_put(skb
->nfct
);
694 /* Assign conntrack already in hashes to this skbuff. Don't
695 * modify skb->nfctinfo to ensure consistent stateful filtering.
697 skb
->nfct
= &ct
->ct_general
;
700 NF_CT_STAT_INC(net
, drop
);
704 /* Confirm a connection given skb; places it in hash table */
706 __nf_conntrack_confirm(struct sk_buff
*skb
)
708 const struct nf_conntrack_zone
*zone
;
709 unsigned int hash
, reply_hash
;
710 struct nf_conntrack_tuple_hash
*h
;
712 struct nf_conn_help
*help
;
713 struct nf_conn_tstamp
*tstamp
;
714 struct hlist_nulls_node
*n
;
715 enum ip_conntrack_info ctinfo
;
717 unsigned int sequence
;
720 ct
= nf_ct_get(skb
, &ctinfo
);
723 /* ipt_REJECT uses nf_conntrack_attach to attach related
724 ICMP/TCP RST packets in other direction. Actual packet
725 which created connection will be IP_CT_NEW or for an
726 expected connection, IP_CT_RELATED. */
727 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
730 zone
= nf_ct_zone(ct
);
734 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
735 /* reuse the hash saved before */
736 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
737 hash
= scale_hash(hash
);
738 reply_hash
= hash_conntrack(net
,
739 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
741 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
743 /* We're not in hash table, and we refuse to set up related
744 * connections for unconfirmed conns. But packet copies and
745 * REJECT will give spurious warnings here.
747 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
749 /* No external references means no one else could have
752 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
753 pr_debug("Confirming conntrack %p\n", ct
);
754 /* We have to check the DYING flag after unlink to prevent
755 * a race against nf_ct_get_next_corpse() possibly called from
756 * user context, else we insert an already 'dead' hash, blocking
757 * further use of that particular connection -JM.
759 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
761 if (unlikely(nf_ct_is_dying(ct
))) {
762 nf_ct_add_to_dying_list(ct
);
766 /* See if there's one in the list already, including reverse:
767 NAT could have grabbed it without realizing, since we're
768 not in the hash. If there is, we lost race. */
769 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
770 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
774 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
775 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
779 /* Timer relative to confirmation time, not original
780 setting time, otherwise we'd get timer wrap in
781 weird delay cases. */
782 ct
->timeout
+= nfct_time_stamp
;
783 atomic_inc(&ct
->ct_general
.use
);
784 ct
->status
|= IPS_CONFIRMED
;
786 /* set conntrack timestamp, if enabled. */
787 tstamp
= nf_conn_tstamp_find(ct
);
789 if (skb
->tstamp
.tv64
== 0)
790 __net_timestamp(skb
);
792 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
794 /* Since the lookup is lockless, hash insertion must be done after
795 * starting the timer and setting the CONFIRMED bit. The RCU barriers
796 * guarantee that no other CPU can find the conntrack before the above
797 * stores are visible.
799 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
800 nf_conntrack_double_unlock(hash
, reply_hash
);
801 NF_CT_STAT_INC(net
, insert
);
804 help
= nfct_help(ct
);
805 if (help
&& help
->helper
)
806 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
808 nf_conntrack_event_cache(master_ct(ct
) ?
809 IPCT_RELATED
: IPCT_NEW
, ct
);
813 nf_ct_add_to_dying_list(ct
);
814 ret
= nf_ct_resolve_clash(net
, skb
, ctinfo
, h
);
816 nf_conntrack_double_unlock(hash
, reply_hash
);
817 NF_CT_STAT_INC(net
, insert_failed
);
821 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
823 /* Returns true if a connection correspondings to the tuple (required
826 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
827 const struct nf_conn
*ignored_conntrack
)
829 struct net
*net
= nf_ct_net(ignored_conntrack
);
830 const struct nf_conntrack_zone
*zone
;
831 struct nf_conntrack_tuple_hash
*h
;
832 struct hlist_nulls_head
*ct_hash
;
833 unsigned int hash
, hsize
;
834 struct hlist_nulls_node
*n
;
837 zone
= nf_ct_zone(ignored_conntrack
);
841 nf_conntrack_get_ht(&ct_hash
, &hsize
);
842 hash
= __hash_conntrack(net
, tuple
, hsize
);
844 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[hash
], hnnode
) {
845 ct
= nf_ct_tuplehash_to_ctrack(h
);
847 if (ct
== ignored_conntrack
)
850 if (nf_ct_is_expired(ct
)) {
851 nf_ct_gc_expired(ct
);
855 if (nf_ct_key_equal(h
, tuple
, zone
, net
)) {
856 NF_CT_STAT_INC_ATOMIC(net
, found
);
860 NF_CT_STAT_INC_ATOMIC(net
, searched
);
863 if (get_nulls_value(n
) != hash
) {
864 NF_CT_STAT_INC_ATOMIC(net
, search_restart
);
872 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
874 #define NF_CT_EVICTION_RANGE 8
876 /* There's a small race here where we may free a just-assured
877 connection. Too bad: we're in trouble anyway. */
878 static unsigned int early_drop_list(struct net
*net
,
879 struct hlist_nulls_head
*head
)
881 struct nf_conntrack_tuple_hash
*h
;
882 struct hlist_nulls_node
*n
;
883 unsigned int drops
= 0;
886 hlist_nulls_for_each_entry_rcu(h
, n
, head
, hnnode
) {
887 tmp
= nf_ct_tuplehash_to_ctrack(h
);
889 if (nf_ct_is_expired(tmp
)) {
890 nf_ct_gc_expired(tmp
);
894 if (test_bit(IPS_ASSURED_BIT
, &tmp
->status
) ||
895 !net_eq(nf_ct_net(tmp
), net
) ||
899 if (!atomic_inc_not_zero(&tmp
->ct_general
.use
))
902 /* kill only if still in same netns -- might have moved due to
903 * SLAB_DESTROY_BY_RCU rules.
905 * We steal the timer reference. If that fails timer has
906 * already fired or someone else deleted it. Just drop ref
907 * and move to next entry.
909 if (net_eq(nf_ct_net(tmp
), net
) &&
910 nf_ct_is_confirmed(tmp
) &&
911 nf_ct_delete(tmp
, 0, 0))
920 static noinline
int early_drop(struct net
*net
, unsigned int _hash
)
924 for (i
= 0; i
< NF_CT_EVICTION_RANGE
; i
++) {
925 struct hlist_nulls_head
*ct_hash
;
926 unsigned int hash
, hsize
, drops
;
929 nf_conntrack_get_ht(&ct_hash
, &hsize
);
930 hash
= reciprocal_scale(_hash
++, hsize
);
932 drops
= early_drop_list(net
, &ct_hash
[hash
]);
936 NF_CT_STAT_ADD_ATOMIC(net
, early_drop
, drops
);
944 static void gc_worker(struct work_struct
*work
)
946 unsigned int i
, goal
, buckets
= 0, expired_count
= 0;
947 unsigned long next_run
= GC_INTERVAL
;
948 unsigned int ratio
, scanned
= 0;
949 struct conntrack_gc_work
*gc_work
;
951 gc_work
= container_of(work
, struct conntrack_gc_work
, dwork
.work
);
953 goal
= min(nf_conntrack_htable_size
/ GC_MAX_BUCKETS_DIV
, GC_MAX_BUCKETS
);
954 i
= gc_work
->last_bucket
;
957 struct nf_conntrack_tuple_hash
*h
;
958 struct hlist_nulls_head
*ct_hash
;
959 struct hlist_nulls_node
*n
;
966 nf_conntrack_get_ht(&ct_hash
, &hashsz
);
970 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[i
], hnnode
) {
971 tmp
= nf_ct_tuplehash_to_ctrack(h
);
974 if (nf_ct_is_expired(tmp
)) {
975 nf_ct_gc_expired(tmp
);
981 /* could check get_nulls_value() here and restart if ct
982 * was moved to another chain. But given gc is best-effort
983 * we will just continue with next hash slot.
986 cond_resched_rcu_qs();
987 } while (++buckets
< goal
&&
988 expired_count
< GC_MAX_EVICTS
);
990 if (gc_work
->exiting
)
993 ratio
= scanned
? expired_count
* 100 / scanned
: 0;
997 gc_work
->last_bucket
= i
;
998 schedule_delayed_work(&gc_work
->dwork
, next_run
);
1001 static void conntrack_gc_work_init(struct conntrack_gc_work
*gc_work
)
1003 INIT_DELAYED_WORK(&gc_work
->dwork
, gc_worker
);
1004 gc_work
->exiting
= false;
1007 static struct nf_conn
*
1008 __nf_conntrack_alloc(struct net
*net
,
1009 const struct nf_conntrack_zone
*zone
,
1010 const struct nf_conntrack_tuple
*orig
,
1011 const struct nf_conntrack_tuple
*repl
,
1012 gfp_t gfp
, u32 hash
)
1016 /* We don't want any race condition at early drop stage */
1017 atomic_inc(&net
->ct
.count
);
1019 if (nf_conntrack_max
&&
1020 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
1021 if (!early_drop(net
, hash
)) {
1022 atomic_dec(&net
->ct
.count
);
1023 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
1024 return ERR_PTR(-ENOMEM
);
1029 * Do not use kmem_cache_zalloc(), as this cache uses
1030 * SLAB_DESTROY_BY_RCU.
1032 ct
= kmem_cache_alloc(nf_conntrack_cachep
, gfp
);
1036 spin_lock_init(&ct
->lock
);
1037 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
1038 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
1039 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
1040 /* save hash for reusing when confirming */
1041 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
1043 write_pnet(&ct
->ct_net
, net
);
1044 memset(&ct
->__nfct_init_offset
[0], 0,
1045 offsetof(struct nf_conn
, proto
) -
1046 offsetof(struct nf_conn
, __nfct_init_offset
[0]));
1048 nf_ct_zone_add(ct
, zone
);
1050 /* Because we use RCU lookups, we set ct_general.use to zero before
1051 * this is inserted in any list.
1053 atomic_set(&ct
->ct_general
.use
, 0);
1056 atomic_dec(&net
->ct
.count
);
1057 return ERR_PTR(-ENOMEM
);
1060 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
1061 const struct nf_conntrack_zone
*zone
,
1062 const struct nf_conntrack_tuple
*orig
,
1063 const struct nf_conntrack_tuple
*repl
,
1066 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
1068 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
1070 void nf_conntrack_free(struct nf_conn
*ct
)
1072 struct net
*net
= nf_ct_net(ct
);
1074 /* A freed object has refcnt == 0, that's
1075 * the golden rule for SLAB_DESTROY_BY_RCU
1077 NF_CT_ASSERT(atomic_read(&ct
->ct_general
.use
) == 0);
1079 nf_ct_ext_destroy(ct
);
1081 kmem_cache_free(nf_conntrack_cachep
, ct
);
1082 smp_mb__before_atomic();
1083 atomic_dec(&net
->ct
.count
);
1085 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
1088 /* Allocate a new conntrack: we return -ENOMEM if classification
1089 failed due to stress. Otherwise it really is unclassifiable. */
1090 static struct nf_conntrack_tuple_hash
*
1091 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
1092 const struct nf_conntrack_tuple
*tuple
,
1093 struct nf_conntrack_l3proto
*l3proto
,
1094 struct nf_conntrack_l4proto
*l4proto
,
1095 struct sk_buff
*skb
,
1096 unsigned int dataoff
, u32 hash
)
1099 struct nf_conn_help
*help
;
1100 struct nf_conntrack_tuple repl_tuple
;
1101 struct nf_conntrack_ecache
*ecache
;
1102 struct nf_conntrack_expect
*exp
= NULL
;
1103 const struct nf_conntrack_zone
*zone
;
1104 struct nf_conn_timeout
*timeout_ext
;
1105 struct nf_conntrack_zone tmp
;
1106 unsigned int *timeouts
;
1108 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
1109 pr_debug("Can't invert tuple.\n");
1113 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1114 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
1117 return (struct nf_conntrack_tuple_hash
*)ct
;
1119 if (tmpl
&& nfct_synproxy(tmpl
)) {
1120 nfct_seqadj_ext_add(ct
);
1121 nfct_synproxy_ext_add(ct
);
1124 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
1126 timeouts
= nf_ct_timeout_data(timeout_ext
);
1127 if (unlikely(!timeouts
))
1128 timeouts
= l4proto
->get_timeouts(net
);
1130 timeouts
= l4proto
->get_timeouts(net
);
1133 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
1134 nf_conntrack_free(ct
);
1135 pr_debug("can't track with proto module\n");
1140 nf_ct_timeout_ext_add(ct
, rcu_dereference(timeout_ext
->timeout
),
1143 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
1144 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
1145 nf_ct_labels_ext_add(ct
);
1147 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
1148 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
1149 ecache
? ecache
->expmask
: 0,
1153 if (net
->ct
.expect_count
) {
1154 spin_lock(&nf_conntrack_expect_lock
);
1155 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
1157 pr_debug("expectation arrives ct=%p exp=%p\n",
1159 /* Welcome, Mr. Bond. We've been expecting you... */
1160 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
1161 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1162 ct
->master
= exp
->master
;
1164 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
1167 rcu_assign_pointer(help
->helper
, exp
->helper
);
1170 #ifdef CONFIG_NF_CONNTRACK_MARK
1171 ct
->mark
= exp
->master
->mark
;
1173 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1174 ct
->secmark
= exp
->master
->secmark
;
1176 NF_CT_STAT_INC(net
, expect_new
);
1178 spin_unlock(&nf_conntrack_expect_lock
);
1181 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
1182 NF_CT_STAT_INC(net
, new);
1185 /* Now it is inserted into the unconfirmed list, bump refcount */
1186 nf_conntrack_get(&ct
->ct_general
);
1187 nf_ct_add_to_unconfirmed_list(ct
);
1193 exp
->expectfn(ct
, exp
);
1194 nf_ct_expect_put(exp
);
1197 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
1200 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1201 static inline struct nf_conn
*
1202 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
1203 struct sk_buff
*skb
,
1204 unsigned int dataoff
,
1207 struct nf_conntrack_l3proto
*l3proto
,
1208 struct nf_conntrack_l4proto
*l4proto
,
1210 enum ip_conntrack_info
*ctinfo
)
1212 const struct nf_conntrack_zone
*zone
;
1213 struct nf_conntrack_tuple tuple
;
1214 struct nf_conntrack_tuple_hash
*h
;
1215 struct nf_conntrack_zone tmp
;
1219 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
1220 dataoff
, l3num
, protonum
, net
, &tuple
, l3proto
,
1222 pr_debug("Can't get tuple\n");
1226 /* look for tuple match */
1227 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1228 hash
= hash_conntrack_raw(&tuple
, net
);
1229 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
1231 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
1232 skb
, dataoff
, hash
);
1238 ct
= nf_ct_tuplehash_to_ctrack(h
);
1240 /* It exists; we have (non-exclusive) reference. */
1241 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
1242 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
1243 /* Please set reply bit if this packet OK */
1246 /* Once we've had two way comms, always ESTABLISHED. */
1247 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
1248 pr_debug("normal packet for %p\n", ct
);
1249 *ctinfo
= IP_CT_ESTABLISHED
;
1250 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
1251 pr_debug("related packet for %p\n", ct
);
1252 *ctinfo
= IP_CT_RELATED
;
1254 pr_debug("new packet for %p\n", ct
);
1255 *ctinfo
= IP_CT_NEW
;
1259 skb
->nfct
= &ct
->ct_general
;
1260 skb
->nfctinfo
= *ctinfo
;
1265 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
1266 struct sk_buff
*skb
)
1268 struct nf_conn
*ct
, *tmpl
= NULL
;
1269 enum ip_conntrack_info ctinfo
;
1270 struct nf_conntrack_l3proto
*l3proto
;
1271 struct nf_conntrack_l4proto
*l4proto
;
1272 unsigned int *timeouts
;
1273 unsigned int dataoff
;
1279 /* Previously seen (loopback or untracked)? Ignore. */
1280 tmpl
= (struct nf_conn
*)skb
->nfct
;
1281 if (!nf_ct_is_template(tmpl
)) {
1282 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
1288 /* rcu_read_lock()ed by nf_hook_slow */
1289 l3proto
= __nf_ct_l3proto_find(pf
);
1290 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
1291 &dataoff
, &protonum
);
1293 pr_debug("not prepared to track yet or error occurred\n");
1294 NF_CT_STAT_INC_ATOMIC(net
, error
);
1295 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1300 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
1302 /* It may be an special packet, error, unclean...
1303 * inverse of the return code tells to the netfilter
1304 * core what to do with the packet. */
1305 if (l4proto
->error
!= NULL
) {
1306 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
1309 NF_CT_STAT_INC_ATOMIC(net
, error
);
1310 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1314 /* ICMP[v6] protocol trackers may assign one conntrack. */
1319 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
1320 l3proto
, l4proto
, &set_reply
, &ctinfo
);
1322 /* Not valid part of a connection */
1323 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1329 /* Too stressed to deal. */
1330 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1335 NF_CT_ASSERT(skb
->nfct
);
1337 /* Decide what timeout policy we want to apply to this flow. */
1338 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1340 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1342 /* Invalid: inverse of the return code tells
1343 * the netfilter core what to do */
1344 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1345 nf_conntrack_put(skb
->nfct
);
1347 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1348 if (ret
== -NF_DROP
)
1349 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1354 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1355 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1358 /* Special case: we have to repeat this hook, assign the
1359 * template again to this packet. We assume that this packet
1360 * has no conntrack assigned. This is used by nf_ct_tcp. */
1361 if (ret
== NF_REPEAT
)
1362 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1369 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1371 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1372 const struct nf_conntrack_tuple
*orig
)
1377 ret
= nf_ct_invert_tuple(inverse
, orig
,
1378 __nf_ct_l3proto_find(orig
->src
.l3num
),
1379 __nf_ct_l4proto_find(orig
->src
.l3num
,
1380 orig
->dst
.protonum
));
1384 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1386 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1387 implicitly racy: see __nf_conntrack_confirm */
1388 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1389 const struct nf_conntrack_tuple
*newreply
)
1391 struct nf_conn_help
*help
= nfct_help(ct
);
1393 /* Should be unconfirmed, so not in hash table yet */
1394 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1396 pr_debug("Altering reply tuple of %p to ", ct
);
1397 nf_ct_dump_tuple(newreply
);
1399 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1400 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1404 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1407 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1409 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1410 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1411 enum ip_conntrack_info ctinfo
,
1412 const struct sk_buff
*skb
,
1413 unsigned long extra_jiffies
,
1418 /* Only update if this is not a fixed timeout */
1419 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1422 /* If not in hash table, timer will not be active yet */
1423 if (nf_ct_is_confirmed(ct
))
1424 extra_jiffies
+= nfct_time_stamp
;
1426 ct
->timeout
= extra_jiffies
;
1429 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1431 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1433 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1434 enum ip_conntrack_info ctinfo
,
1435 const struct sk_buff
*skb
,
1439 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1441 return nf_ct_delete(ct
, 0, 0);
1443 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1445 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1447 #include <linux/netfilter/nfnetlink.h>
1448 #include <linux/netfilter/nfnetlink_conntrack.h>
1449 #include <linux/mutex.h>
1451 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1452 * in ip_conntrack_core, since we don't want the protocols to autoload
1453 * or depend on ctnetlink */
1454 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1455 const struct nf_conntrack_tuple
*tuple
)
1457 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1458 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1459 goto nla_put_failure
;
1465 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1467 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1468 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1469 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1471 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1473 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1474 struct nf_conntrack_tuple
*t
)
1476 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1479 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1480 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1484 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1486 int nf_ct_port_nlattr_tuple_size(void)
1488 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1490 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1493 /* Used by ipt_REJECT and ip6t_REJECT. */
1494 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1497 enum ip_conntrack_info ctinfo
;
1499 /* This ICMP is in reverse direction to the packet which caused it */
1500 ct
= nf_ct_get(skb
, &ctinfo
);
1501 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1502 ctinfo
= IP_CT_RELATED_REPLY
;
1504 ctinfo
= IP_CT_RELATED
;
1506 /* Attach to new skbuff, and increment count */
1507 nskb
->nfct
= &ct
->ct_general
;
1508 nskb
->nfctinfo
= ctinfo
;
1509 nf_conntrack_get(nskb
->nfct
);
1512 /* Bring out ya dead! */
1513 static struct nf_conn
*
1514 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1515 void *data
, unsigned int *bucket
)
1517 struct nf_conntrack_tuple_hash
*h
;
1519 struct hlist_nulls_node
*n
;
1523 for (; *bucket
< nf_conntrack_htable_size
; (*bucket
)++) {
1524 lockp
= &nf_conntrack_locks
[*bucket
% CONNTRACK_LOCKS
];
1526 nf_conntrack_lock(lockp
);
1527 if (*bucket
< nf_conntrack_htable_size
) {
1528 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[*bucket
], hnnode
) {
1529 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1531 ct
= nf_ct_tuplehash_to_ctrack(h
);
1532 if (net_eq(nf_ct_net(ct
), net
) &&
1542 for_each_possible_cpu(cpu
) {
1543 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1545 spin_lock_bh(&pcpu
->lock
);
1546 hlist_nulls_for_each_entry(h
, n
, &pcpu
->unconfirmed
, hnnode
) {
1547 ct
= nf_ct_tuplehash_to_ctrack(h
);
1549 set_bit(IPS_DYING_BIT
, &ct
->status
);
1551 spin_unlock_bh(&pcpu
->lock
);
1556 atomic_inc(&ct
->ct_general
.use
);
1562 void nf_ct_iterate_cleanup(struct net
*net
,
1563 int (*iter
)(struct nf_conn
*i
, void *data
),
1564 void *data
, u32 portid
, int report
)
1567 unsigned int bucket
= 0;
1571 if (atomic_read(&net
->ct
.count
) == 0)
1574 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1575 /* Time to push up daises... */
1577 nf_ct_delete(ct
, portid
, report
);
1582 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1584 static int kill_all(struct nf_conn
*i
, void *data
)
1589 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1591 if (is_vmalloc_addr(hash
))
1594 free_pages((unsigned long)hash
,
1595 get_order(sizeof(struct hlist_head
) * size
));
1597 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1599 static int untrack_refs(void)
1603 for_each_possible_cpu(cpu
) {
1604 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1606 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1611 void nf_conntrack_cleanup_start(void)
1613 conntrack_gc_work
.exiting
= true;
1614 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1617 void nf_conntrack_cleanup_end(void)
1619 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1620 while (untrack_refs() > 0)
1623 cancel_delayed_work_sync(&conntrack_gc_work
.dwork
);
1624 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1626 nf_conntrack_proto_fini();
1627 nf_conntrack_seqadj_fini();
1628 nf_conntrack_labels_fini();
1629 nf_conntrack_helper_fini();
1630 nf_conntrack_timeout_fini();
1631 nf_conntrack_ecache_fini();
1632 nf_conntrack_tstamp_fini();
1633 nf_conntrack_acct_fini();
1634 nf_conntrack_expect_fini();
1636 kmem_cache_destroy(nf_conntrack_cachep
);
1640 * Mishearing the voices in his head, our hero wonders how he's
1641 * supposed to kill the mall.
1643 void nf_conntrack_cleanup_net(struct net
*net
)
1647 list_add(&net
->exit_list
, &single
);
1648 nf_conntrack_cleanup_net_list(&single
);
1651 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1657 * This makes sure all current packets have passed through
1658 * netfilter framework. Roll on, two-stage module
1664 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1665 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1666 if (atomic_read(&net
->ct
.count
) != 0)
1671 goto i_see_dead_people
;
1674 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1675 nf_conntrack_proto_pernet_fini(net
);
1676 nf_conntrack_helper_pernet_fini(net
);
1677 nf_conntrack_ecache_pernet_fini(net
);
1678 nf_conntrack_tstamp_pernet_fini(net
);
1679 nf_conntrack_acct_pernet_fini(net
);
1680 nf_conntrack_expect_pernet_fini(net
);
1681 free_percpu(net
->ct
.stat
);
1682 free_percpu(net
->ct
.pcpu_lists
);
1686 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1688 struct hlist_nulls_head
*hash
;
1689 unsigned int nr_slots
, i
;
1692 if (*sizep
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1695 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1696 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1698 if (nr_slots
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1701 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1702 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1708 for (i
= 0; i
< nr_slots
; i
++)
1709 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1713 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1715 int nf_conntrack_hash_resize(unsigned int hashsize
)
1718 unsigned int old_size
;
1719 struct hlist_nulls_head
*hash
, *old_hash
;
1720 struct nf_conntrack_tuple_hash
*h
;
1726 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1730 old_size
= nf_conntrack_htable_size
;
1731 if (old_size
== hashsize
) {
1732 nf_ct_free_hashtable(hash
, hashsize
);
1737 nf_conntrack_all_lock();
1738 write_seqcount_begin(&nf_conntrack_generation
);
1740 /* Lookups in the old hash might happen in parallel, which means we
1741 * might get false negatives during connection lookup. New connections
1742 * created because of a false negative won't make it into the hash
1743 * though since that required taking the locks.
1746 for (i
= 0; i
< nf_conntrack_htable_size
; i
++) {
1747 while (!hlist_nulls_empty(&nf_conntrack_hash
[i
])) {
1748 h
= hlist_nulls_entry(nf_conntrack_hash
[i
].first
,
1749 struct nf_conntrack_tuple_hash
, hnnode
);
1750 ct
= nf_ct_tuplehash_to_ctrack(h
);
1751 hlist_nulls_del_rcu(&h
->hnnode
);
1752 bucket
= __hash_conntrack(nf_ct_net(ct
),
1753 &h
->tuple
, hashsize
);
1754 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1757 old_size
= nf_conntrack_htable_size
;
1758 old_hash
= nf_conntrack_hash
;
1760 nf_conntrack_hash
= hash
;
1761 nf_conntrack_htable_size
= hashsize
;
1763 write_seqcount_end(&nf_conntrack_generation
);
1764 nf_conntrack_all_unlock();
1768 nf_ct_free_hashtable(old_hash
, old_size
);
1772 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1774 unsigned int hashsize
;
1777 if (current
->nsproxy
->net_ns
!= &init_net
)
1780 /* On boot, we can set this without any fancy locking. */
1781 if (!nf_conntrack_htable_size
)
1782 return param_set_uint(val
, kp
);
1784 rc
= kstrtouint(val
, 0, &hashsize
);
1788 return nf_conntrack_hash_resize(hashsize
);
1790 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1792 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1793 &nf_conntrack_htable_size
, 0600);
1795 void nf_ct_untracked_status_or(unsigned long bits
)
1799 for_each_possible_cpu(cpu
)
1800 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1802 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1804 int nf_conntrack_init_start(void)
1810 seqcount_init(&nf_conntrack_generation
);
1812 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
1813 spin_lock_init(&nf_conntrack_locks
[i
]);
1815 if (!nf_conntrack_htable_size
) {
1816 /* Idea from tcp.c: use 1/16384 of memory.
1817 * On i386: 32MB machine has 512 buckets.
1818 * >= 1GB machines have 16384 buckets.
1819 * >= 4GB machines have 65536 buckets.
1821 nf_conntrack_htable_size
1822 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1823 / sizeof(struct hlist_head
));
1824 if (totalram_pages
> (4 * (1024 * 1024 * 1024 / PAGE_SIZE
)))
1825 nf_conntrack_htable_size
= 65536;
1826 else if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1827 nf_conntrack_htable_size
= 16384;
1828 if (nf_conntrack_htable_size
< 32)
1829 nf_conntrack_htable_size
= 32;
1831 /* Use a max. factor of four by default to get the same max as
1832 * with the old struct list_heads. When a table size is given
1833 * we use the old value of 8 to avoid reducing the max.
1838 nf_conntrack_hash
= nf_ct_alloc_hashtable(&nf_conntrack_htable_size
, 1);
1839 if (!nf_conntrack_hash
)
1842 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1844 nf_conntrack_cachep
= kmem_cache_create("nf_conntrack",
1845 sizeof(struct nf_conn
), 0,
1846 SLAB_DESTROY_BY_RCU
| SLAB_HWCACHE_ALIGN
, NULL
);
1847 if (!nf_conntrack_cachep
)
1850 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1851 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1854 ret
= nf_conntrack_expect_init();
1858 ret
= nf_conntrack_acct_init();
1862 ret
= nf_conntrack_tstamp_init();
1866 ret
= nf_conntrack_ecache_init();
1870 ret
= nf_conntrack_timeout_init();
1874 ret
= nf_conntrack_helper_init();
1878 ret
= nf_conntrack_labels_init();
1882 ret
= nf_conntrack_seqadj_init();
1886 ret
= nf_conntrack_proto_init();
1890 /* Set up fake conntrack: to never be deleted, not in any hashes */
1891 for_each_possible_cpu(cpu
) {
1892 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1893 write_pnet(&ct
->ct_net
, &init_net
);
1894 atomic_set(&ct
->ct_general
.use
, 1);
1896 /* - and look it like as a confirmed connection */
1897 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1899 conntrack_gc_work_init(&conntrack_gc_work
);
1900 schedule_delayed_work(&conntrack_gc_work
.dwork
, GC_INTERVAL
);
1905 nf_conntrack_seqadj_fini();
1907 nf_conntrack_labels_fini();
1909 nf_conntrack_helper_fini();
1911 nf_conntrack_timeout_fini();
1913 nf_conntrack_ecache_fini();
1915 nf_conntrack_tstamp_fini();
1917 nf_conntrack_acct_fini();
1919 nf_conntrack_expect_fini();
1921 kmem_cache_destroy(nf_conntrack_cachep
);
1923 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1927 void nf_conntrack_init_end(void)
1929 /* For use by REJECT target */
1930 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1931 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1935 * We need to use special "null" values, not used in hash table
1937 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1938 #define DYING_NULLS_VAL ((1<<30)+1)
1939 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1941 int nf_conntrack_init_net(struct net
*net
)
1946 atomic_set(&net
->ct
.count
, 0);
1948 net
->ct
.pcpu_lists
= alloc_percpu(struct ct_pcpu
);
1949 if (!net
->ct
.pcpu_lists
)
1952 for_each_possible_cpu(cpu
) {
1953 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1955 spin_lock_init(&pcpu
->lock
);
1956 INIT_HLIST_NULLS_HEAD(&pcpu
->unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1957 INIT_HLIST_NULLS_HEAD(&pcpu
->dying
, DYING_NULLS_VAL
);
1960 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1962 goto err_pcpu_lists
;
1964 ret
= nf_conntrack_expect_pernet_init(net
);
1967 ret
= nf_conntrack_acct_pernet_init(net
);
1970 ret
= nf_conntrack_tstamp_pernet_init(net
);
1973 ret
= nf_conntrack_ecache_pernet_init(net
);
1976 ret
= nf_conntrack_helper_pernet_init(net
);
1979 ret
= nf_conntrack_proto_pernet_init(net
);
1985 nf_conntrack_helper_pernet_fini(net
);
1987 nf_conntrack_ecache_pernet_fini(net
);
1989 nf_conntrack_tstamp_pernet_fini(net
);
1991 nf_conntrack_acct_pernet_fini(net
);
1993 nf_conntrack_expect_pernet_fini(net
);
1995 free_percpu(net
->ct
.stat
);
1997 free_percpu(net
->ct
.pcpu_lists
);