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 static __read_mostly
struct kmem_cache
*nf_conntrack_cachep
;
76 static __read_mostly spinlock_t nf_conntrack_locks_all_lock
;
77 static __read_mostly seqcount_t nf_conntrack_generation
;
78 static __read_mostly
DEFINE_SPINLOCK(nf_conntrack_locks_all_lock
);
79 static __read_mostly
bool nf_conntrack_locks_all
;
81 void nf_conntrack_lock(spinlock_t
*lock
) __acquires(lock
)
84 while (unlikely(nf_conntrack_locks_all
)) {
88 * Order the 'nf_conntrack_locks_all' load vs. the
89 * spin_unlock_wait() loads below, to ensure
90 * that 'nf_conntrack_locks_all_lock' is indeed held:
92 smp_rmb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
93 spin_unlock_wait(&nf_conntrack_locks_all_lock
);
97 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
99 static void nf_conntrack_double_unlock(unsigned int h1
, unsigned int h2
)
101 h1
%= CONNTRACK_LOCKS
;
102 h2
%= CONNTRACK_LOCKS
;
103 spin_unlock(&nf_conntrack_locks
[h1
]);
105 spin_unlock(&nf_conntrack_locks
[h2
]);
108 /* return true if we need to recompute hashes (in case hash table was resized) */
109 static bool nf_conntrack_double_lock(struct net
*net
, unsigned int h1
,
110 unsigned int h2
, unsigned int sequence
)
112 h1
%= CONNTRACK_LOCKS
;
113 h2
%= CONNTRACK_LOCKS
;
115 nf_conntrack_lock(&nf_conntrack_locks
[h1
]);
117 spin_lock_nested(&nf_conntrack_locks
[h2
],
118 SINGLE_DEPTH_NESTING
);
120 nf_conntrack_lock(&nf_conntrack_locks
[h2
]);
121 spin_lock_nested(&nf_conntrack_locks
[h1
],
122 SINGLE_DEPTH_NESTING
);
124 if (read_seqcount_retry(&nf_conntrack_generation
, sequence
)) {
125 nf_conntrack_double_unlock(h1
, h2
);
131 static void nf_conntrack_all_lock(void)
135 spin_lock(&nf_conntrack_locks_all_lock
);
136 nf_conntrack_locks_all
= true;
139 * Order the above store of 'nf_conntrack_locks_all' against
140 * the spin_unlock_wait() loads below, such that if
141 * nf_conntrack_lock() observes 'nf_conntrack_locks_all'
142 * we must observe nf_conntrack_locks[] held:
144 smp_mb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
146 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++) {
147 spin_unlock_wait(&nf_conntrack_locks
[i
]);
151 static void nf_conntrack_all_unlock(void)
154 * All prior stores must be complete before we clear
155 * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
156 * might observe the false value but not the entire
159 smp_store_release(&nf_conntrack_locks_all
, false);
160 spin_unlock(&nf_conntrack_locks_all_lock
);
163 unsigned int nf_conntrack_htable_size __read_mostly
;
164 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
166 unsigned int nf_conntrack_max __read_mostly
;
167 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
169 DEFINE_PER_CPU(struct nf_conn
, nf_conntrack_untracked
);
170 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked
);
172 static unsigned int nf_conntrack_hash_rnd __read_mostly
;
174 static u32
hash_conntrack_raw(const struct nf_conntrack_tuple
*tuple
,
175 const struct net
*net
)
180 get_random_once(&nf_conntrack_hash_rnd
, sizeof(nf_conntrack_hash_rnd
));
182 /* The direction must be ignored, so we hash everything up to the
183 * destination ports (which is a multiple of 4) and treat the last
184 * three bytes manually.
186 seed
= nf_conntrack_hash_rnd
^ net_hash_mix(net
);
187 n
= (sizeof(tuple
->src
) + sizeof(tuple
->dst
.u3
)) / sizeof(u32
);
188 return jhash2((u32
*)tuple
, n
, seed
^
189 (((__force __u16
)tuple
->dst
.u
.all
<< 16) |
190 tuple
->dst
.protonum
));
193 static u32
scale_hash(u32 hash
)
195 return reciprocal_scale(hash
, nf_conntrack_htable_size
);
198 static u32
__hash_conntrack(const struct net
*net
,
199 const struct nf_conntrack_tuple
*tuple
,
202 return reciprocal_scale(hash_conntrack_raw(tuple
, net
), size
);
205 static u32
hash_conntrack(const struct net
*net
,
206 const struct nf_conntrack_tuple
*tuple
)
208 return scale_hash(hash_conntrack_raw(tuple
, net
));
212 nf_ct_get_tuple(const struct sk_buff
*skb
,
214 unsigned int dataoff
,
218 struct nf_conntrack_tuple
*tuple
,
219 const struct nf_conntrack_l3proto
*l3proto
,
220 const struct nf_conntrack_l4proto
*l4proto
)
222 memset(tuple
, 0, sizeof(*tuple
));
224 tuple
->src
.l3num
= l3num
;
225 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
228 tuple
->dst
.protonum
= protonum
;
229 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
231 return l4proto
->pkt_to_tuple(skb
, dataoff
, net
, tuple
);
233 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
235 bool nf_ct_get_tuplepr(const struct sk_buff
*skb
, unsigned int nhoff
,
237 struct net
*net
, struct nf_conntrack_tuple
*tuple
)
239 struct nf_conntrack_l3proto
*l3proto
;
240 struct nf_conntrack_l4proto
*l4proto
;
241 unsigned int protoff
;
247 l3proto
= __nf_ct_l3proto_find(l3num
);
248 ret
= l3proto
->get_l4proto(skb
, nhoff
, &protoff
, &protonum
);
249 if (ret
!= NF_ACCEPT
) {
254 l4proto
= __nf_ct_l4proto_find(l3num
, protonum
);
256 ret
= nf_ct_get_tuple(skb
, nhoff
, protoff
, l3num
, protonum
, net
, tuple
,
262 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr
);
265 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
266 const struct nf_conntrack_tuple
*orig
,
267 const struct nf_conntrack_l3proto
*l3proto
,
268 const struct nf_conntrack_l4proto
*l4proto
)
270 memset(inverse
, 0, sizeof(*inverse
));
272 inverse
->src
.l3num
= orig
->src
.l3num
;
273 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
276 inverse
->dst
.dir
= !orig
->dst
.dir
;
278 inverse
->dst
.protonum
= orig
->dst
.protonum
;
279 return l4proto
->invert_tuple(inverse
, orig
);
281 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
284 clean_from_lists(struct nf_conn
*ct
)
286 pr_debug("clean_from_lists(%p)\n", ct
);
287 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
288 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
);
290 /* Destroy all pending expectations */
291 nf_ct_remove_expectations(ct
);
294 /* must be called with local_bh_disable */
295 static void nf_ct_add_to_dying_list(struct nf_conn
*ct
)
297 struct ct_pcpu
*pcpu
;
299 /* add this conntrack to the (per cpu) dying list */
300 ct
->cpu
= smp_processor_id();
301 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
303 spin_lock(&pcpu
->lock
);
304 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
306 spin_unlock(&pcpu
->lock
);
309 /* must be called with local_bh_disable */
310 static void nf_ct_add_to_unconfirmed_list(struct nf_conn
*ct
)
312 struct ct_pcpu
*pcpu
;
314 /* add this conntrack to the (per cpu) unconfirmed list */
315 ct
->cpu
= smp_processor_id();
316 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
318 spin_lock(&pcpu
->lock
);
319 hlist_nulls_add_head(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
321 spin_unlock(&pcpu
->lock
);
324 /* must be called with local_bh_disable */
325 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn
*ct
)
327 struct ct_pcpu
*pcpu
;
329 /* We overload first tuple to link into unconfirmed or dying list.*/
330 pcpu
= per_cpu_ptr(nf_ct_net(ct
)->ct
.pcpu_lists
, ct
->cpu
);
332 spin_lock(&pcpu
->lock
);
333 BUG_ON(hlist_nulls_unhashed(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
));
334 hlist_nulls_del_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
);
335 spin_unlock(&pcpu
->lock
);
338 /* Released via destroy_conntrack() */
339 struct nf_conn
*nf_ct_tmpl_alloc(struct net
*net
,
340 const struct nf_conntrack_zone
*zone
,
343 struct nf_conn
*tmpl
;
345 tmpl
= kzalloc(sizeof(*tmpl
), flags
);
349 tmpl
->status
= IPS_TEMPLATE
;
350 write_pnet(&tmpl
->ct_net
, net
);
351 nf_ct_zone_add(tmpl
, zone
);
352 atomic_set(&tmpl
->ct_general
.use
, 0);
356 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc
);
358 void nf_ct_tmpl_free(struct nf_conn
*tmpl
)
360 nf_ct_ext_destroy(tmpl
);
361 nf_ct_ext_free(tmpl
);
364 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free
);
367 destroy_conntrack(struct nf_conntrack
*nfct
)
369 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
370 struct net
*net
= nf_ct_net(ct
);
371 struct nf_conntrack_l4proto
*l4proto
;
373 pr_debug("destroy_conntrack(%p)\n", ct
);
374 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
375 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
377 if (unlikely(nf_ct_is_template(ct
))) {
382 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
383 if (l4proto
->destroy
)
384 l4proto
->destroy(ct
);
389 /* Expectations will have been removed in clean_from_lists,
390 * except TFTP can create an expectation on the first packet,
391 * before connection is in the list, so we need to clean here,
394 nf_ct_remove_expectations(ct
);
396 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
398 NF_CT_STAT_INC(net
, delete);
402 nf_ct_put(ct
->master
);
404 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct
);
405 nf_conntrack_free(ct
);
408 static void nf_ct_delete_from_lists(struct nf_conn
*ct
)
410 struct net
*net
= nf_ct_net(ct
);
411 unsigned int hash
, reply_hash
;
412 unsigned int sequence
;
414 nf_ct_helper_destroy(ct
);
418 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
419 hash
= hash_conntrack(net
,
420 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
421 reply_hash
= hash_conntrack(net
,
422 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
423 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
425 clean_from_lists(ct
);
426 nf_conntrack_double_unlock(hash
, reply_hash
);
428 nf_ct_add_to_dying_list(ct
);
430 NF_CT_STAT_INC(net
, delete_list
);
434 bool nf_ct_delete(struct nf_conn
*ct
, u32 portid
, int report
)
436 struct nf_conn_tstamp
*tstamp
;
438 tstamp
= nf_conn_tstamp_find(ct
);
439 if (tstamp
&& tstamp
->stop
== 0)
440 tstamp
->stop
= ktime_get_real_ns();
442 if (nf_ct_is_dying(ct
))
445 if (nf_conntrack_event_report(IPCT_DESTROY
, ct
,
446 portid
, report
) < 0) {
447 /* destroy event was not delivered */
448 nf_ct_delete_from_lists(ct
);
449 nf_conntrack_ecache_delayed_work(nf_ct_net(ct
));
453 nf_conntrack_ecache_work(nf_ct_net(ct
));
454 set_bit(IPS_DYING_BIT
, &ct
->status
);
456 nf_ct_delete_from_lists(ct
);
460 EXPORT_SYMBOL_GPL(nf_ct_delete
);
462 static void death_by_timeout(unsigned long ul_conntrack
)
464 nf_ct_delete((struct nf_conn
*)ul_conntrack
, 0, 0);
468 nf_ct_key_equal(struct nf_conntrack_tuple_hash
*h
,
469 const struct nf_conntrack_tuple
*tuple
,
470 const struct nf_conntrack_zone
*zone
,
471 const struct net
*net
)
473 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
475 /* A conntrack can be recreated with the equal tuple,
476 * so we need to check that the conntrack is confirmed
478 return nf_ct_tuple_equal(tuple
, &h
->tuple
) &&
479 nf_ct_zone_equal(ct
, zone
, NF_CT_DIRECTION(h
)) &&
480 nf_ct_is_confirmed(ct
) &&
481 net_eq(net
, nf_ct_net(ct
));
484 /* must be called with rcu read lock held */
485 void nf_conntrack_get_ht(struct hlist_nulls_head
**hash
, unsigned int *hsize
)
487 struct hlist_nulls_head
*hptr
;
488 unsigned int sequence
, hsz
;
491 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
492 hsz
= nf_conntrack_htable_size
;
493 hptr
= nf_conntrack_hash
;
494 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
499 EXPORT_SYMBOL_GPL(nf_conntrack_get_ht
);
503 * - Caller must take a reference on returned object
504 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
506 static struct nf_conntrack_tuple_hash
*
507 ____nf_conntrack_find(struct net
*net
, const struct nf_conntrack_zone
*zone
,
508 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
510 struct nf_conntrack_tuple_hash
*h
;
511 struct hlist_nulls_head
*ct_hash
;
512 struct hlist_nulls_node
*n
;
513 unsigned int bucket
, sequence
;
517 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
518 bucket
= scale_hash(hash
);
519 ct_hash
= nf_conntrack_hash
;
520 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
522 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[bucket
], hnnode
) {
523 if (nf_ct_key_equal(h
, tuple
, zone
, net
)) {
524 NF_CT_STAT_INC_ATOMIC(net
, found
);
527 NF_CT_STAT_INC_ATOMIC(net
, searched
);
530 * if the nulls value we got at the end of this lookup is
531 * not the expected one, we must restart lookup.
532 * We probably met an item that was moved to another chain.
534 if (get_nulls_value(n
) != bucket
) {
535 NF_CT_STAT_INC_ATOMIC(net
, search_restart
);
542 /* Find a connection corresponding to a tuple. */
543 static struct nf_conntrack_tuple_hash
*
544 __nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
545 const struct nf_conntrack_tuple
*tuple
, u32 hash
)
547 struct nf_conntrack_tuple_hash
*h
;
552 h
= ____nf_conntrack_find(net
, zone
, tuple
, hash
);
554 ct
= nf_ct_tuplehash_to_ctrack(h
);
555 if (unlikely(nf_ct_is_dying(ct
) ||
556 !atomic_inc_not_zero(&ct
->ct_general
.use
)))
559 if (unlikely(!nf_ct_key_equal(h
, tuple
, zone
, net
))) {
570 struct nf_conntrack_tuple_hash
*
571 nf_conntrack_find_get(struct net
*net
, const struct nf_conntrack_zone
*zone
,
572 const struct nf_conntrack_tuple
*tuple
)
574 return __nf_conntrack_find_get(net
, zone
, tuple
,
575 hash_conntrack_raw(tuple
, net
));
577 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
579 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
581 unsigned int reply_hash
)
583 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
,
584 &nf_conntrack_hash
[hash
]);
585 hlist_nulls_add_head_rcu(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
,
586 &nf_conntrack_hash
[reply_hash
]);
590 nf_conntrack_hash_check_insert(struct nf_conn
*ct
)
592 const struct nf_conntrack_zone
*zone
;
593 struct net
*net
= nf_ct_net(ct
);
594 unsigned int hash
, reply_hash
;
595 struct nf_conntrack_tuple_hash
*h
;
596 struct hlist_nulls_node
*n
;
597 unsigned int sequence
;
599 zone
= nf_ct_zone(ct
);
603 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
604 hash
= hash_conntrack(net
,
605 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
606 reply_hash
= hash_conntrack(net
,
607 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
608 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
610 /* See if there's one in the list already, including reverse */
611 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
612 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
616 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
617 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
621 add_timer(&ct
->timeout
);
623 /* The caller holds a reference to this object */
624 atomic_set(&ct
->ct_general
.use
, 2);
625 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
626 nf_conntrack_double_unlock(hash
, reply_hash
);
627 NF_CT_STAT_INC(net
, insert
);
632 nf_conntrack_double_unlock(hash
, reply_hash
);
633 NF_CT_STAT_INC(net
, insert_failed
);
637 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert
);
639 static inline void nf_ct_acct_update(struct nf_conn
*ct
,
640 enum ip_conntrack_info ctinfo
,
643 struct nf_conn_acct
*acct
;
645 acct
= nf_conn_acct_find(ct
);
647 struct nf_conn_counter
*counter
= acct
->counter
;
649 atomic64_inc(&counter
[CTINFO2DIR(ctinfo
)].packets
);
650 atomic64_add(len
, &counter
[CTINFO2DIR(ctinfo
)].bytes
);
654 static void nf_ct_acct_merge(struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
,
655 const struct nf_conn
*loser_ct
)
657 struct nf_conn_acct
*acct
;
659 acct
= nf_conn_acct_find(loser_ct
);
661 struct nf_conn_counter
*counter
= acct
->counter
;
664 /* u32 should be fine since we must have seen one packet. */
665 bytes
= atomic64_read(&counter
[CTINFO2DIR(ctinfo
)].bytes
);
666 nf_ct_acct_update(ct
, ctinfo
, bytes
);
670 /* Resolve race on insertion if this protocol allows this. */
671 static int nf_ct_resolve_clash(struct net
*net
, struct sk_buff
*skb
,
672 enum ip_conntrack_info ctinfo
,
673 struct nf_conntrack_tuple_hash
*h
)
675 /* This is the conntrack entry already in hashes that won race. */
676 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
677 struct nf_conntrack_l4proto
*l4proto
;
679 l4proto
= __nf_ct_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
680 if (l4proto
->allow_clash
&&
682 !nf_ct_is_dying(ct
) &&
683 atomic_inc_not_zero(&ct
->ct_general
.use
)) {
684 nf_ct_acct_merge(ct
, ctinfo
, (struct nf_conn
*)skb
->nfct
);
685 nf_conntrack_put(skb
->nfct
);
686 /* Assign conntrack already in hashes to this skbuff. Don't
687 * modify skb->nfctinfo to ensure consistent stateful filtering.
689 skb
->nfct
= &ct
->ct_general
;
692 NF_CT_STAT_INC(net
, drop
);
696 /* Confirm a connection given skb; places it in hash table */
698 __nf_conntrack_confirm(struct sk_buff
*skb
)
700 const struct nf_conntrack_zone
*zone
;
701 unsigned int hash
, reply_hash
;
702 struct nf_conntrack_tuple_hash
*h
;
704 struct nf_conn_help
*help
;
705 struct nf_conn_tstamp
*tstamp
;
706 struct hlist_nulls_node
*n
;
707 enum ip_conntrack_info ctinfo
;
709 unsigned int sequence
;
712 ct
= nf_ct_get(skb
, &ctinfo
);
715 /* ipt_REJECT uses nf_conntrack_attach to attach related
716 ICMP/TCP RST packets in other direction. Actual packet
717 which created connection will be IP_CT_NEW or for an
718 expected connection, IP_CT_RELATED. */
719 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
722 zone
= nf_ct_zone(ct
);
726 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
727 /* reuse the hash saved before */
728 hash
= *(unsigned long *)&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
;
729 hash
= scale_hash(hash
);
730 reply_hash
= hash_conntrack(net
,
731 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
733 } while (nf_conntrack_double_lock(net
, hash
, reply_hash
, sequence
));
735 /* We're not in hash table, and we refuse to set up related
736 * connections for unconfirmed conns. But packet copies and
737 * REJECT will give spurious warnings here.
739 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
741 /* No external references means no one else could have
744 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
745 pr_debug("Confirming conntrack %p\n", ct
);
746 /* We have to check the DYING flag after unlink to prevent
747 * a race against nf_ct_get_next_corpse() possibly called from
748 * user context, else we insert an already 'dead' hash, blocking
749 * further use of that particular connection -JM.
751 nf_ct_del_from_dying_or_unconfirmed_list(ct
);
753 if (unlikely(nf_ct_is_dying(ct
))) {
754 nf_ct_add_to_dying_list(ct
);
758 /* See if there's one in the list already, including reverse:
759 NAT could have grabbed it without realizing, since we're
760 not in the hash. If there is, we lost race. */
761 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[hash
], hnnode
)
762 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
766 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[reply_hash
], hnnode
)
767 if (nf_ct_key_equal(h
, &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
771 /* Timer relative to confirmation time, not original
772 setting time, otherwise we'd get timer wrap in
773 weird delay cases. */
774 ct
->timeout
.expires
+= jiffies
;
775 add_timer(&ct
->timeout
);
776 atomic_inc(&ct
->ct_general
.use
);
777 ct
->status
|= IPS_CONFIRMED
;
779 /* set conntrack timestamp, if enabled. */
780 tstamp
= nf_conn_tstamp_find(ct
);
782 if (skb
->tstamp
.tv64
== 0)
783 __net_timestamp(skb
);
785 tstamp
->start
= ktime_to_ns(skb
->tstamp
);
787 /* Since the lookup is lockless, hash insertion must be done after
788 * starting the timer and setting the CONFIRMED bit. The RCU barriers
789 * guarantee that no other CPU can find the conntrack before the above
790 * stores are visible.
792 __nf_conntrack_hash_insert(ct
, hash
, reply_hash
);
793 nf_conntrack_double_unlock(hash
, reply_hash
);
794 NF_CT_STAT_INC(net
, insert
);
797 help
= nfct_help(ct
);
798 if (help
&& help
->helper
)
799 nf_conntrack_event_cache(IPCT_HELPER
, ct
);
801 nf_conntrack_event_cache(master_ct(ct
) ?
802 IPCT_RELATED
: IPCT_NEW
, ct
);
806 nf_ct_add_to_dying_list(ct
);
807 ret
= nf_ct_resolve_clash(net
, skb
, ctinfo
, h
);
809 nf_conntrack_double_unlock(hash
, reply_hash
);
810 NF_CT_STAT_INC(net
, insert_failed
);
814 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
816 /* Returns true if a connection correspondings to the tuple (required
819 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
820 const struct nf_conn
*ignored_conntrack
)
822 struct net
*net
= nf_ct_net(ignored_conntrack
);
823 const struct nf_conntrack_zone
*zone
;
824 struct nf_conntrack_tuple_hash
*h
;
825 struct hlist_nulls_head
*ct_hash
;
826 unsigned int hash
, sequence
;
827 struct hlist_nulls_node
*n
;
830 zone
= nf_ct_zone(ignored_conntrack
);
834 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
835 hash
= hash_conntrack(net
, tuple
);
836 ct_hash
= nf_conntrack_hash
;
837 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
839 hlist_nulls_for_each_entry_rcu(h
, n
, &ct_hash
[hash
], hnnode
) {
840 ct
= nf_ct_tuplehash_to_ctrack(h
);
841 if (ct
!= ignored_conntrack
&&
842 nf_ct_key_equal(h
, tuple
, zone
, net
)) {
843 NF_CT_STAT_INC_ATOMIC(net
, found
);
847 NF_CT_STAT_INC_ATOMIC(net
, searched
);
853 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
855 #define NF_CT_EVICTION_RANGE 8
857 /* There's a small race here where we may free a just-assured
858 connection. Too bad: we're in trouble anyway. */
859 static unsigned int early_drop_list(struct net
*net
,
860 struct hlist_nulls_head
*head
)
862 struct nf_conntrack_tuple_hash
*h
;
863 struct hlist_nulls_node
*n
;
864 unsigned int drops
= 0;
867 hlist_nulls_for_each_entry_rcu(h
, n
, head
, hnnode
) {
868 tmp
= nf_ct_tuplehash_to_ctrack(h
);
870 if (test_bit(IPS_ASSURED_BIT
, &tmp
->status
) ||
871 !net_eq(nf_ct_net(tmp
), net
) ||
875 if (!atomic_inc_not_zero(&tmp
->ct_general
.use
))
878 /* kill only if still in same netns -- might have moved due to
879 * SLAB_DESTROY_BY_RCU rules.
881 * We steal the timer reference. If that fails timer has
882 * already fired or someone else deleted it. Just drop ref
883 * and move to next entry.
885 if (net_eq(nf_ct_net(tmp
), net
) &&
886 nf_ct_is_confirmed(tmp
) &&
887 del_timer(&tmp
->timeout
) &&
888 nf_ct_delete(tmp
, 0, 0))
897 static noinline
int early_drop(struct net
*net
, unsigned int _hash
)
901 for (i
= 0; i
< NF_CT_EVICTION_RANGE
; i
++) {
902 struct hlist_nulls_head
*ct_hash
;
903 unsigned hash
, sequence
, drops
;
907 sequence
= read_seqcount_begin(&nf_conntrack_generation
);
908 hash
= scale_hash(_hash
++);
909 ct_hash
= nf_conntrack_hash
;
910 } while (read_seqcount_retry(&nf_conntrack_generation
, sequence
));
912 drops
= early_drop_list(net
, &ct_hash
[hash
]);
916 NF_CT_STAT_ADD_ATOMIC(net
, early_drop
, drops
);
924 static struct nf_conn
*
925 __nf_conntrack_alloc(struct net
*net
,
926 const struct nf_conntrack_zone
*zone
,
927 const struct nf_conntrack_tuple
*orig
,
928 const struct nf_conntrack_tuple
*repl
,
933 /* We don't want any race condition at early drop stage */
934 atomic_inc(&net
->ct
.count
);
936 if (nf_conntrack_max
&&
937 unlikely(atomic_read(&net
->ct
.count
) > nf_conntrack_max
)) {
938 if (!early_drop(net
, hash
)) {
939 atomic_dec(&net
->ct
.count
);
940 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
941 return ERR_PTR(-ENOMEM
);
946 * Do not use kmem_cache_zalloc(), as this cache uses
947 * SLAB_DESTROY_BY_RCU.
949 ct
= kmem_cache_alloc(nf_conntrack_cachep
, gfp
);
953 spin_lock_init(&ct
->lock
);
954 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
955 ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].hnnode
.pprev
= NULL
;
956 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
957 /* save hash for reusing when confirming */
958 *(unsigned long *)(&ct
->tuplehash
[IP_CT_DIR_REPLY
].hnnode
.pprev
) = hash
;
960 /* Don't set timer yet: wait for confirmation */
961 setup_timer(&ct
->timeout
, death_by_timeout
, (unsigned long)ct
);
962 write_pnet(&ct
->ct_net
, net
);
963 memset(&ct
->__nfct_init_offset
[0], 0,
964 offsetof(struct nf_conn
, proto
) -
965 offsetof(struct nf_conn
, __nfct_init_offset
[0]));
967 nf_ct_zone_add(ct
, zone
);
969 /* Because we use RCU lookups, we set ct_general.use to zero before
970 * this is inserted in any list.
972 atomic_set(&ct
->ct_general
.use
, 0);
975 atomic_dec(&net
->ct
.count
);
976 return ERR_PTR(-ENOMEM
);
979 struct nf_conn
*nf_conntrack_alloc(struct net
*net
,
980 const struct nf_conntrack_zone
*zone
,
981 const struct nf_conntrack_tuple
*orig
,
982 const struct nf_conntrack_tuple
*repl
,
985 return __nf_conntrack_alloc(net
, zone
, orig
, repl
, gfp
, 0);
987 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
989 void nf_conntrack_free(struct nf_conn
*ct
)
991 struct net
*net
= nf_ct_net(ct
);
993 /* A freed object has refcnt == 0, that's
994 * the golden rule for SLAB_DESTROY_BY_RCU
996 NF_CT_ASSERT(atomic_read(&ct
->ct_general
.use
) == 0);
998 nf_ct_ext_destroy(ct
);
1000 kmem_cache_free(nf_conntrack_cachep
, ct
);
1001 smp_mb__before_atomic();
1002 atomic_dec(&net
->ct
.count
);
1004 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
1007 /* Allocate a new conntrack: we return -ENOMEM if classification
1008 failed due to stress. Otherwise it really is unclassifiable. */
1009 static struct nf_conntrack_tuple_hash
*
1010 init_conntrack(struct net
*net
, struct nf_conn
*tmpl
,
1011 const struct nf_conntrack_tuple
*tuple
,
1012 struct nf_conntrack_l3proto
*l3proto
,
1013 struct nf_conntrack_l4proto
*l4proto
,
1014 struct sk_buff
*skb
,
1015 unsigned int dataoff
, u32 hash
)
1018 struct nf_conn_help
*help
;
1019 struct nf_conntrack_tuple repl_tuple
;
1020 struct nf_conntrack_ecache
*ecache
;
1021 struct nf_conntrack_expect
*exp
= NULL
;
1022 const struct nf_conntrack_zone
*zone
;
1023 struct nf_conn_timeout
*timeout_ext
;
1024 struct nf_conntrack_zone tmp
;
1025 unsigned int *timeouts
;
1027 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
1028 pr_debug("Can't invert tuple.\n");
1032 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1033 ct
= __nf_conntrack_alloc(net
, zone
, tuple
, &repl_tuple
, GFP_ATOMIC
,
1036 return (struct nf_conntrack_tuple_hash
*)ct
;
1038 if (tmpl
&& nfct_synproxy(tmpl
)) {
1039 nfct_seqadj_ext_add(ct
);
1040 nfct_synproxy_ext_add(ct
);
1043 timeout_ext
= tmpl
? nf_ct_timeout_find(tmpl
) : NULL
;
1045 timeouts
= nf_ct_timeout_data(timeout_ext
);
1046 if (unlikely(!timeouts
))
1047 timeouts
= l4proto
->get_timeouts(net
);
1049 timeouts
= l4proto
->get_timeouts(net
);
1052 if (!l4proto
->new(ct
, skb
, dataoff
, timeouts
)) {
1053 nf_conntrack_free(ct
);
1054 pr_debug("can't track with proto module\n");
1059 nf_ct_timeout_ext_add(ct
, rcu_dereference(timeout_ext
->timeout
),
1062 nf_ct_acct_ext_add(ct
, GFP_ATOMIC
);
1063 nf_ct_tstamp_ext_add(ct
, GFP_ATOMIC
);
1064 nf_ct_labels_ext_add(ct
);
1066 ecache
= tmpl
? nf_ct_ecache_find(tmpl
) : NULL
;
1067 nf_ct_ecache_ext_add(ct
, ecache
? ecache
->ctmask
: 0,
1068 ecache
? ecache
->expmask
: 0,
1072 if (net
->ct
.expect_count
) {
1073 spin_lock(&nf_conntrack_expect_lock
);
1074 exp
= nf_ct_find_expectation(net
, zone
, tuple
);
1076 pr_debug("expectation arrives ct=%p exp=%p\n",
1078 /* Welcome, Mr. Bond. We've been expecting you... */
1079 __set_bit(IPS_EXPECTED_BIT
, &ct
->status
);
1080 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1081 ct
->master
= exp
->master
;
1083 help
= nf_ct_helper_ext_add(ct
, exp
->helper
,
1086 rcu_assign_pointer(help
->helper
, exp
->helper
);
1089 #ifdef CONFIG_NF_CONNTRACK_MARK
1090 ct
->mark
= exp
->master
->mark
;
1092 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1093 ct
->secmark
= exp
->master
->secmark
;
1095 NF_CT_STAT_INC(net
, expect_new
);
1097 spin_unlock(&nf_conntrack_expect_lock
);
1100 __nf_ct_try_assign_helper(ct
, tmpl
, GFP_ATOMIC
);
1101 NF_CT_STAT_INC(net
, new);
1104 /* Now it is inserted into the unconfirmed list, bump refcount */
1105 nf_conntrack_get(&ct
->ct_general
);
1106 nf_ct_add_to_unconfirmed_list(ct
);
1112 exp
->expectfn(ct
, exp
);
1113 nf_ct_expect_put(exp
);
1116 return &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
];
1119 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1120 static inline struct nf_conn
*
1121 resolve_normal_ct(struct net
*net
, struct nf_conn
*tmpl
,
1122 struct sk_buff
*skb
,
1123 unsigned int dataoff
,
1126 struct nf_conntrack_l3proto
*l3proto
,
1127 struct nf_conntrack_l4proto
*l4proto
,
1129 enum ip_conntrack_info
*ctinfo
)
1131 const struct nf_conntrack_zone
*zone
;
1132 struct nf_conntrack_tuple tuple
;
1133 struct nf_conntrack_tuple_hash
*h
;
1134 struct nf_conntrack_zone tmp
;
1138 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
1139 dataoff
, l3num
, protonum
, net
, &tuple
, l3proto
,
1141 pr_debug("Can't get tuple\n");
1145 /* look for tuple match */
1146 zone
= nf_ct_zone_tmpl(tmpl
, skb
, &tmp
);
1147 hash
= hash_conntrack_raw(&tuple
, net
);
1148 h
= __nf_conntrack_find_get(net
, zone
, &tuple
, hash
);
1150 h
= init_conntrack(net
, tmpl
, &tuple
, l3proto
, l4proto
,
1151 skb
, dataoff
, hash
);
1157 ct
= nf_ct_tuplehash_to_ctrack(h
);
1159 /* It exists; we have (non-exclusive) reference. */
1160 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
1161 *ctinfo
= IP_CT_ESTABLISHED_REPLY
;
1162 /* Please set reply bit if this packet OK */
1165 /* Once we've had two way comms, always ESTABLISHED. */
1166 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
1167 pr_debug("normal packet for %p\n", ct
);
1168 *ctinfo
= IP_CT_ESTABLISHED
;
1169 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
1170 pr_debug("related packet for %p\n", ct
);
1171 *ctinfo
= IP_CT_RELATED
;
1173 pr_debug("new packet for %p\n", ct
);
1174 *ctinfo
= IP_CT_NEW
;
1178 skb
->nfct
= &ct
->ct_general
;
1179 skb
->nfctinfo
= *ctinfo
;
1184 nf_conntrack_in(struct net
*net
, u_int8_t pf
, unsigned int hooknum
,
1185 struct sk_buff
*skb
)
1187 struct nf_conn
*ct
, *tmpl
= NULL
;
1188 enum ip_conntrack_info ctinfo
;
1189 struct nf_conntrack_l3proto
*l3proto
;
1190 struct nf_conntrack_l4proto
*l4proto
;
1191 unsigned int *timeouts
;
1192 unsigned int dataoff
;
1198 /* Previously seen (loopback or untracked)? Ignore. */
1199 tmpl
= (struct nf_conn
*)skb
->nfct
;
1200 if (!nf_ct_is_template(tmpl
)) {
1201 NF_CT_STAT_INC_ATOMIC(net
, ignore
);
1207 /* rcu_read_lock()ed by nf_hook_slow */
1208 l3proto
= __nf_ct_l3proto_find(pf
);
1209 ret
= l3proto
->get_l4proto(skb
, skb_network_offset(skb
),
1210 &dataoff
, &protonum
);
1212 pr_debug("not prepared to track yet or error occurred\n");
1213 NF_CT_STAT_INC_ATOMIC(net
, error
);
1214 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1219 l4proto
= __nf_ct_l4proto_find(pf
, protonum
);
1221 /* It may be an special packet, error, unclean...
1222 * inverse of the return code tells to the netfilter
1223 * core what to do with the packet. */
1224 if (l4proto
->error
!= NULL
) {
1225 ret
= l4proto
->error(net
, tmpl
, skb
, dataoff
, &ctinfo
,
1228 NF_CT_STAT_INC_ATOMIC(net
, error
);
1229 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1233 /* ICMP[v6] protocol trackers may assign one conntrack. */
1238 ct
= resolve_normal_ct(net
, tmpl
, skb
, dataoff
, pf
, protonum
,
1239 l3proto
, l4proto
, &set_reply
, &ctinfo
);
1241 /* Not valid part of a connection */
1242 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1248 /* Too stressed to deal. */
1249 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1254 NF_CT_ASSERT(skb
->nfct
);
1256 /* Decide what timeout policy we want to apply to this flow. */
1257 timeouts
= nf_ct_timeout_lookup(net
, ct
, l4proto
);
1259 ret
= l4proto
->packet(ct
, skb
, dataoff
, ctinfo
, pf
, hooknum
, timeouts
);
1261 /* Invalid: inverse of the return code tells
1262 * the netfilter core what to do */
1263 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1264 nf_conntrack_put(skb
->nfct
);
1266 NF_CT_STAT_INC_ATOMIC(net
, invalid
);
1267 if (ret
== -NF_DROP
)
1268 NF_CT_STAT_INC_ATOMIC(net
, drop
);
1273 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
1274 nf_conntrack_event_cache(IPCT_REPLY
, ct
);
1277 /* Special case: we have to repeat this hook, assign the
1278 * template again to this packet. We assume that this packet
1279 * has no conntrack assigned. This is used by nf_ct_tcp. */
1280 if (ret
== NF_REPEAT
)
1281 skb
->nfct
= (struct nf_conntrack
*)tmpl
;
1288 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
1290 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
1291 const struct nf_conntrack_tuple
*orig
)
1296 ret
= nf_ct_invert_tuple(inverse
, orig
,
1297 __nf_ct_l3proto_find(orig
->src
.l3num
),
1298 __nf_ct_l4proto_find(orig
->src
.l3num
,
1299 orig
->dst
.protonum
));
1303 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
1305 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1306 implicitly racy: see __nf_conntrack_confirm */
1307 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
1308 const struct nf_conntrack_tuple
*newreply
)
1310 struct nf_conn_help
*help
= nfct_help(ct
);
1312 /* Should be unconfirmed, so not in hash table yet */
1313 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
1315 pr_debug("Altering reply tuple of %p to ", ct
);
1316 nf_ct_dump_tuple(newreply
);
1318 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
1319 if (ct
->master
|| (help
&& !hlist_empty(&help
->expectations
)))
1323 __nf_ct_try_assign_helper(ct
, NULL
, GFP_ATOMIC
);
1326 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
1328 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1329 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
1330 enum ip_conntrack_info ctinfo
,
1331 const struct sk_buff
*skb
,
1332 unsigned long extra_jiffies
,
1335 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
1338 /* Only update if this is not a fixed timeout */
1339 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
))
1342 /* If not in hash table, timer will not be active yet */
1343 if (!nf_ct_is_confirmed(ct
)) {
1344 ct
->timeout
.expires
= extra_jiffies
;
1346 unsigned long newtime
= jiffies
+ extra_jiffies
;
1348 /* Only update the timeout if the new timeout is at least
1349 HZ jiffies from the old timeout. Need del_timer for race
1350 avoidance (may already be dying). */
1351 if (newtime
- ct
->timeout
.expires
>= HZ
)
1352 mod_timer_pending(&ct
->timeout
, newtime
);
1357 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1359 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
1361 bool __nf_ct_kill_acct(struct nf_conn
*ct
,
1362 enum ip_conntrack_info ctinfo
,
1363 const struct sk_buff
*skb
,
1367 nf_ct_acct_update(ct
, ctinfo
, skb
->len
);
1369 if (del_timer(&ct
->timeout
)) {
1370 ct
->timeout
.function((unsigned long)ct
);
1375 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct
);
1377 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1379 #include <linux/netfilter/nfnetlink.h>
1380 #include <linux/netfilter/nfnetlink_conntrack.h>
1381 #include <linux/mutex.h>
1383 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1384 * in ip_conntrack_core, since we don't want the protocols to autoload
1385 * or depend on ctnetlink */
1386 int nf_ct_port_tuple_to_nlattr(struct sk_buff
*skb
,
1387 const struct nf_conntrack_tuple
*tuple
)
1389 if (nla_put_be16(skb
, CTA_PROTO_SRC_PORT
, tuple
->src
.u
.tcp
.port
) ||
1390 nla_put_be16(skb
, CTA_PROTO_DST_PORT
, tuple
->dst
.u
.tcp
.port
))
1391 goto nla_put_failure
;
1397 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr
);
1399 const struct nla_policy nf_ct_port_nla_policy
[CTA_PROTO_MAX
+1] = {
1400 [CTA_PROTO_SRC_PORT
] = { .type
= NLA_U16
},
1401 [CTA_PROTO_DST_PORT
] = { .type
= NLA_U16
},
1403 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy
);
1405 int nf_ct_port_nlattr_to_tuple(struct nlattr
*tb
[],
1406 struct nf_conntrack_tuple
*t
)
1408 if (!tb
[CTA_PROTO_SRC_PORT
] || !tb
[CTA_PROTO_DST_PORT
])
1411 t
->src
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_SRC_PORT
]);
1412 t
->dst
.u
.tcp
.port
= nla_get_be16(tb
[CTA_PROTO_DST_PORT
]);
1416 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple
);
1418 int nf_ct_port_nlattr_tuple_size(void)
1420 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1422 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size
);
1425 /* Used by ipt_REJECT and ip6t_REJECT. */
1426 static void nf_conntrack_attach(struct sk_buff
*nskb
, const struct sk_buff
*skb
)
1429 enum ip_conntrack_info ctinfo
;
1431 /* This ICMP is in reverse direction to the packet which caused it */
1432 ct
= nf_ct_get(skb
, &ctinfo
);
1433 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
1434 ctinfo
= IP_CT_RELATED_REPLY
;
1436 ctinfo
= IP_CT_RELATED
;
1438 /* Attach to new skbuff, and increment count */
1439 nskb
->nfct
= &ct
->ct_general
;
1440 nskb
->nfctinfo
= ctinfo
;
1441 nf_conntrack_get(nskb
->nfct
);
1444 /* Bring out ya dead! */
1445 static struct nf_conn
*
1446 get_next_corpse(struct net
*net
, int (*iter
)(struct nf_conn
*i
, void *data
),
1447 void *data
, unsigned int *bucket
)
1449 struct nf_conntrack_tuple_hash
*h
;
1451 struct hlist_nulls_node
*n
;
1455 for (; *bucket
< nf_conntrack_htable_size
; (*bucket
)++) {
1456 lockp
= &nf_conntrack_locks
[*bucket
% CONNTRACK_LOCKS
];
1458 nf_conntrack_lock(lockp
);
1459 if (*bucket
< nf_conntrack_htable_size
) {
1460 hlist_nulls_for_each_entry(h
, n
, &nf_conntrack_hash
[*bucket
], hnnode
) {
1461 if (NF_CT_DIRECTION(h
) != IP_CT_DIR_ORIGINAL
)
1463 ct
= nf_ct_tuplehash_to_ctrack(h
);
1464 if (net_eq(nf_ct_net(ct
), net
) &&
1474 for_each_possible_cpu(cpu
) {
1475 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1477 spin_lock_bh(&pcpu
->lock
);
1478 hlist_nulls_for_each_entry(h
, n
, &pcpu
->unconfirmed
, hnnode
) {
1479 ct
= nf_ct_tuplehash_to_ctrack(h
);
1481 set_bit(IPS_DYING_BIT
, &ct
->status
);
1483 spin_unlock_bh(&pcpu
->lock
);
1488 atomic_inc(&ct
->ct_general
.use
);
1494 void nf_ct_iterate_cleanup(struct net
*net
,
1495 int (*iter
)(struct nf_conn
*i
, void *data
),
1496 void *data
, u32 portid
, int report
)
1499 unsigned int bucket
= 0;
1503 if (atomic_read(&net
->ct
.count
) == 0)
1506 while ((ct
= get_next_corpse(net
, iter
, data
, &bucket
)) != NULL
) {
1507 /* Time to push up daises... */
1508 if (del_timer(&ct
->timeout
))
1509 nf_ct_delete(ct
, portid
, report
);
1511 /* ... else the timer will get him soon. */
1517 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
1519 static int kill_all(struct nf_conn
*i
, void *data
)
1524 void nf_ct_free_hashtable(void *hash
, unsigned int size
)
1526 if (is_vmalloc_addr(hash
))
1529 free_pages((unsigned long)hash
,
1530 get_order(sizeof(struct hlist_head
) * size
));
1532 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable
);
1534 static int untrack_refs(void)
1538 for_each_possible_cpu(cpu
) {
1539 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1541 cnt
+= atomic_read(&ct
->ct_general
.use
) - 1;
1546 void nf_conntrack_cleanup_start(void)
1548 RCU_INIT_POINTER(ip_ct_attach
, NULL
);
1551 void nf_conntrack_cleanup_end(void)
1553 RCU_INIT_POINTER(nf_ct_destroy
, NULL
);
1554 while (untrack_refs() > 0)
1557 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1559 nf_conntrack_proto_fini();
1560 nf_conntrack_seqadj_fini();
1561 nf_conntrack_labels_fini();
1562 nf_conntrack_helper_fini();
1563 nf_conntrack_timeout_fini();
1564 nf_conntrack_ecache_fini();
1565 nf_conntrack_tstamp_fini();
1566 nf_conntrack_acct_fini();
1567 nf_conntrack_expect_fini();
1569 kmem_cache_destroy(nf_conntrack_cachep
);
1573 * Mishearing the voices in his head, our hero wonders how he's
1574 * supposed to kill the mall.
1576 void nf_conntrack_cleanup_net(struct net
*net
)
1580 list_add(&net
->exit_list
, &single
);
1581 nf_conntrack_cleanup_net_list(&single
);
1584 void nf_conntrack_cleanup_net_list(struct list_head
*net_exit_list
)
1590 * This makes sure all current packets have passed through
1591 * netfilter framework. Roll on, two-stage module
1597 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1598 nf_ct_iterate_cleanup(net
, kill_all
, NULL
, 0, 0);
1599 if (atomic_read(&net
->ct
.count
) != 0)
1604 goto i_see_dead_people
;
1607 list_for_each_entry(net
, net_exit_list
, exit_list
) {
1608 nf_conntrack_proto_pernet_fini(net
);
1609 nf_conntrack_helper_pernet_fini(net
);
1610 nf_conntrack_ecache_pernet_fini(net
);
1611 nf_conntrack_tstamp_pernet_fini(net
);
1612 nf_conntrack_acct_pernet_fini(net
);
1613 nf_conntrack_expect_pernet_fini(net
);
1614 free_percpu(net
->ct
.stat
);
1615 free_percpu(net
->ct
.pcpu_lists
);
1619 void *nf_ct_alloc_hashtable(unsigned int *sizep
, int nulls
)
1621 struct hlist_nulls_head
*hash
;
1622 unsigned int nr_slots
, i
;
1625 if (*sizep
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1628 BUILD_BUG_ON(sizeof(struct hlist_nulls_head
) != sizeof(struct hlist_head
));
1629 nr_slots
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct hlist_nulls_head
));
1631 if (nr_slots
> (UINT_MAX
/ sizeof(struct hlist_nulls_head
)))
1634 sz
= nr_slots
* sizeof(struct hlist_nulls_head
);
1635 hash
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
| __GFP_ZERO
,
1641 for (i
= 0; i
< nr_slots
; i
++)
1642 INIT_HLIST_NULLS_HEAD(&hash
[i
], i
);
1646 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable
);
1648 int nf_conntrack_hash_resize(unsigned int hashsize
)
1651 unsigned int old_size
;
1652 struct hlist_nulls_head
*hash
, *old_hash
;
1653 struct nf_conntrack_tuple_hash
*h
;
1659 hash
= nf_ct_alloc_hashtable(&hashsize
, 1);
1663 old_size
= nf_conntrack_htable_size
;
1664 if (old_size
== hashsize
) {
1665 nf_ct_free_hashtable(hash
, hashsize
);
1670 nf_conntrack_all_lock();
1671 write_seqcount_begin(&nf_conntrack_generation
);
1673 /* Lookups in the old hash might happen in parallel, which means we
1674 * might get false negatives during connection lookup. New connections
1675 * created because of a false negative won't make it into the hash
1676 * though since that required taking the locks.
1679 for (i
= 0; i
< nf_conntrack_htable_size
; i
++) {
1680 while (!hlist_nulls_empty(&nf_conntrack_hash
[i
])) {
1681 h
= hlist_nulls_entry(nf_conntrack_hash
[i
].first
,
1682 struct nf_conntrack_tuple_hash
, hnnode
);
1683 ct
= nf_ct_tuplehash_to_ctrack(h
);
1684 hlist_nulls_del_rcu(&h
->hnnode
);
1685 bucket
= __hash_conntrack(nf_ct_net(ct
),
1686 &h
->tuple
, hashsize
);
1687 hlist_nulls_add_head_rcu(&h
->hnnode
, &hash
[bucket
]);
1690 old_size
= nf_conntrack_htable_size
;
1691 old_hash
= nf_conntrack_hash
;
1693 nf_conntrack_hash
= hash
;
1694 nf_conntrack_htable_size
= hashsize
;
1696 write_seqcount_end(&nf_conntrack_generation
);
1697 nf_conntrack_all_unlock();
1701 nf_ct_free_hashtable(old_hash
, old_size
);
1705 int nf_conntrack_set_hashsize(const char *val
, struct kernel_param
*kp
)
1707 unsigned int hashsize
;
1710 if (current
->nsproxy
->net_ns
!= &init_net
)
1713 /* On boot, we can set this without any fancy locking. */
1714 if (!nf_conntrack_htable_size
)
1715 return param_set_uint(val
, kp
);
1717 rc
= kstrtouint(val
, 0, &hashsize
);
1721 return nf_conntrack_hash_resize(hashsize
);
1723 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize
);
1725 module_param_call(hashsize
, nf_conntrack_set_hashsize
, param_get_uint
,
1726 &nf_conntrack_htable_size
, 0600);
1728 void nf_ct_untracked_status_or(unsigned long bits
)
1732 for_each_possible_cpu(cpu
)
1733 per_cpu(nf_conntrack_untracked
, cpu
).status
|= bits
;
1735 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or
);
1737 int nf_conntrack_init_start(void)
1743 seqcount_init(&nf_conntrack_generation
);
1745 for (i
= 0; i
< CONNTRACK_LOCKS
; i
++)
1746 spin_lock_init(&nf_conntrack_locks
[i
]);
1748 if (!nf_conntrack_htable_size
) {
1749 /* Idea from tcp.c: use 1/16384 of memory.
1750 * On i386: 32MB machine has 512 buckets.
1751 * >= 1GB machines have 16384 buckets.
1752 * >= 4GB machines have 65536 buckets.
1754 nf_conntrack_htable_size
1755 = (((totalram_pages
<< PAGE_SHIFT
) / 16384)
1756 / sizeof(struct hlist_head
));
1757 if (totalram_pages
> (4 * (1024 * 1024 * 1024 / PAGE_SIZE
)))
1758 nf_conntrack_htable_size
= 65536;
1759 else if (totalram_pages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1760 nf_conntrack_htable_size
= 16384;
1761 if (nf_conntrack_htable_size
< 32)
1762 nf_conntrack_htable_size
= 32;
1764 /* Use a max. factor of four by default to get the same max as
1765 * with the old struct list_heads. When a table size is given
1766 * we use the old value of 8 to avoid reducing the max.
1771 nf_conntrack_hash
= nf_ct_alloc_hashtable(&nf_conntrack_htable_size
, 1);
1772 if (!nf_conntrack_hash
)
1775 nf_conntrack_max
= max_factor
* nf_conntrack_htable_size
;
1777 nf_conntrack_cachep
= kmem_cache_create("nf_conntrack",
1778 sizeof(struct nf_conn
), 0,
1779 SLAB_DESTROY_BY_RCU
| SLAB_HWCACHE_ALIGN
, NULL
);
1780 if (!nf_conntrack_cachep
)
1783 printk(KERN_INFO
"nf_conntrack version %s (%u buckets, %d max)\n",
1784 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1787 ret
= nf_conntrack_expect_init();
1791 ret
= nf_conntrack_acct_init();
1795 ret
= nf_conntrack_tstamp_init();
1799 ret
= nf_conntrack_ecache_init();
1803 ret
= nf_conntrack_timeout_init();
1807 ret
= nf_conntrack_helper_init();
1811 ret
= nf_conntrack_labels_init();
1815 ret
= nf_conntrack_seqadj_init();
1819 ret
= nf_conntrack_proto_init();
1823 /* Set up fake conntrack: to never be deleted, not in any hashes */
1824 for_each_possible_cpu(cpu
) {
1825 struct nf_conn
*ct
= &per_cpu(nf_conntrack_untracked
, cpu
);
1826 write_pnet(&ct
->ct_net
, &init_net
);
1827 atomic_set(&ct
->ct_general
.use
, 1);
1829 /* - and look it like as a confirmed connection */
1830 nf_ct_untracked_status_or(IPS_CONFIRMED
| IPS_UNTRACKED
);
1834 nf_conntrack_seqadj_fini();
1836 nf_conntrack_labels_fini();
1838 nf_conntrack_helper_fini();
1840 nf_conntrack_timeout_fini();
1842 nf_conntrack_ecache_fini();
1844 nf_conntrack_tstamp_fini();
1846 nf_conntrack_acct_fini();
1848 nf_conntrack_expect_fini();
1850 kmem_cache_destroy(nf_conntrack_cachep
);
1852 nf_ct_free_hashtable(nf_conntrack_hash
, nf_conntrack_htable_size
);
1856 void nf_conntrack_init_end(void)
1858 /* For use by REJECT target */
1859 RCU_INIT_POINTER(ip_ct_attach
, nf_conntrack_attach
);
1860 RCU_INIT_POINTER(nf_ct_destroy
, destroy_conntrack
);
1864 * We need to use special "null" values, not used in hash table
1866 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1867 #define DYING_NULLS_VAL ((1<<30)+1)
1868 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1870 int nf_conntrack_init_net(struct net
*net
)
1875 atomic_set(&net
->ct
.count
, 0);
1877 net
->ct
.pcpu_lists
= alloc_percpu(struct ct_pcpu
);
1878 if (!net
->ct
.pcpu_lists
)
1881 for_each_possible_cpu(cpu
) {
1882 struct ct_pcpu
*pcpu
= per_cpu_ptr(net
->ct
.pcpu_lists
, cpu
);
1884 spin_lock_init(&pcpu
->lock
);
1885 INIT_HLIST_NULLS_HEAD(&pcpu
->unconfirmed
, UNCONFIRMED_NULLS_VAL
);
1886 INIT_HLIST_NULLS_HEAD(&pcpu
->dying
, DYING_NULLS_VAL
);
1889 net
->ct
.stat
= alloc_percpu(struct ip_conntrack_stat
);
1891 goto err_pcpu_lists
;
1893 ret
= nf_conntrack_expect_pernet_init(net
);
1896 ret
= nf_conntrack_acct_pernet_init(net
);
1899 ret
= nf_conntrack_tstamp_pernet_init(net
);
1902 ret
= nf_conntrack_ecache_pernet_init(net
);
1905 ret
= nf_conntrack_helper_pernet_init(net
);
1908 ret
= nf_conntrack_proto_pernet_init(net
);
1914 nf_conntrack_helper_pernet_fini(net
);
1916 nf_conntrack_ecache_pernet_fini(net
);
1918 nf_conntrack_tstamp_pernet_fini(net
);
1920 nf_conntrack_acct_pernet_fini(net
);
1922 nf_conntrack_expect_pernet_fini(net
);
1924 free_percpu(net
->ct
.stat
);
1926 free_percpu(net
->ct
.pcpu_lists
);