1 /* Connection state tracking for netfilter. This is separated from,
2 but required by, the NAT layer; it can also be used by an iptables
5 /* (C) 1999-2001 Paul `Rusty' Russell
6 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
7 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/proc_fs.h>
19 #include <linux/vmalloc.h>
20 #include <linux/stddef.h>
21 #include <linux/slab.h>
22 #include <linux/random.h>
23 #include <linux/jhash.h>
24 #include <linux/err.h>
25 #include <linux/percpu.h>
26 #include <linux/moduleparam.h>
27 #include <linux/notifier.h>
28 #include <linux/kernel.h>
29 #include <linux/netdevice.h>
30 #include <linux/socket.h>
33 #include <net/netfilter/nf_conntrack.h>
34 #include <net/netfilter/nf_conntrack_l3proto.h>
35 #include <net/netfilter/nf_conntrack_l4proto.h>
36 #include <net/netfilter/nf_conntrack_expect.h>
37 #include <net/netfilter/nf_conntrack_helper.h>
38 #include <net/netfilter/nf_conntrack_core.h>
39 #include <net/netfilter/nf_conntrack_extend.h>
41 #define NF_CONNTRACK_VERSION "0.5.0"
46 #define DEBUGP(format, args...)
49 DEFINE_RWLOCK(nf_conntrack_lock
);
50 EXPORT_SYMBOL_GPL(nf_conntrack_lock
);
52 /* nf_conntrack_standalone needs this */
53 atomic_t nf_conntrack_count
= ATOMIC_INIT(0);
54 EXPORT_SYMBOL_GPL(nf_conntrack_count
);
56 unsigned int nf_conntrack_htable_size __read_mostly
;
57 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size
);
59 int nf_conntrack_max __read_mostly
;
60 EXPORT_SYMBOL_GPL(nf_conntrack_max
);
62 struct list_head
*nf_conntrack_hash __read_mostly
;
63 EXPORT_SYMBOL_GPL(nf_conntrack_hash
);
65 struct nf_conn nf_conntrack_untracked __read_mostly
;
66 EXPORT_SYMBOL_GPL(nf_conntrack_untracked
);
68 unsigned int nf_ct_log_invalid __read_mostly
;
69 LIST_HEAD(unconfirmed
);
70 static int nf_conntrack_vmalloc __read_mostly
;
71 static struct kmem_cache
*nf_conntrack_cachep __read_mostly
;
72 static unsigned int nf_conntrack_next_id
;
74 DEFINE_PER_CPU(struct ip_conntrack_stat
, nf_conntrack_stat
);
75 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat
);
77 static int nf_conntrack_hash_rnd_initted
;
78 static unsigned int nf_conntrack_hash_rnd
;
80 static u_int32_t
__hash_conntrack(const struct nf_conntrack_tuple
*tuple
,
81 unsigned int size
, unsigned int rnd
)
85 a
= jhash2(tuple
->src
.u3
.all
, ARRAY_SIZE(tuple
->src
.u3
.all
),
86 (tuple
->src
.l3num
<< 16) | tuple
->dst
.protonum
);
87 b
= jhash2(tuple
->dst
.u3
.all
, ARRAY_SIZE(tuple
->dst
.u3
.all
),
88 (tuple
->src
.u
.all
<< 16) | tuple
->dst
.u
.all
);
90 return jhash_2words(a
, b
, rnd
) % size
;
93 static inline u_int32_t
hash_conntrack(const struct nf_conntrack_tuple
*tuple
)
95 return __hash_conntrack(tuple
, nf_conntrack_htable_size
,
96 nf_conntrack_hash_rnd
);
100 nf_ct_get_tuple(const struct sk_buff
*skb
,
102 unsigned int dataoff
,
105 struct nf_conntrack_tuple
*tuple
,
106 const struct nf_conntrack_l3proto
*l3proto
,
107 const struct nf_conntrack_l4proto
*l4proto
)
109 NF_CT_TUPLE_U_BLANK(tuple
);
111 tuple
->src
.l3num
= l3num
;
112 if (l3proto
->pkt_to_tuple(skb
, nhoff
, tuple
) == 0)
115 tuple
->dst
.protonum
= protonum
;
116 tuple
->dst
.dir
= IP_CT_DIR_ORIGINAL
;
118 return l4proto
->pkt_to_tuple(skb
, dataoff
, tuple
);
120 EXPORT_SYMBOL_GPL(nf_ct_get_tuple
);
123 nf_ct_invert_tuple(struct nf_conntrack_tuple
*inverse
,
124 const struct nf_conntrack_tuple
*orig
,
125 const struct nf_conntrack_l3proto
*l3proto
,
126 const struct nf_conntrack_l4proto
*l4proto
)
128 NF_CT_TUPLE_U_BLANK(inverse
);
130 inverse
->src
.l3num
= orig
->src
.l3num
;
131 if (l3proto
->invert_tuple(inverse
, orig
) == 0)
134 inverse
->dst
.dir
= !orig
->dst
.dir
;
136 inverse
->dst
.protonum
= orig
->dst
.protonum
;
137 return l4proto
->invert_tuple(inverse
, orig
);
139 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple
);
142 clean_from_lists(struct nf_conn
*ct
)
144 DEBUGP("clean_from_lists(%p)\n", ct
);
145 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
146 list_del(&ct
->tuplehash
[IP_CT_DIR_REPLY
].list
);
148 /* Destroy all pending expectations */
149 nf_ct_remove_expectations(ct
);
153 destroy_conntrack(struct nf_conntrack
*nfct
)
155 struct nf_conn
*ct
= (struct nf_conn
*)nfct
;
156 struct nf_conntrack_l4proto
*l4proto
;
158 DEBUGP("destroy_conntrack(%p)\n", ct
);
159 NF_CT_ASSERT(atomic_read(&nfct
->use
) == 0);
160 NF_CT_ASSERT(!timer_pending(&ct
->timeout
));
162 nf_conntrack_event(IPCT_DESTROY
, ct
);
163 set_bit(IPS_DYING_BIT
, &ct
->status
);
165 /* To make sure we don't get any weird locking issues here:
166 * destroy_conntrack() MUST NOT be called with a write lock
167 * to nf_conntrack_lock!!! -HW */
169 l4proto
= __nf_ct_l4proto_find(ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.l3num
,
170 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.dst
.protonum
);
171 if (l4proto
&& l4proto
->destroy
)
172 l4proto
->destroy(ct
);
174 nf_ct_ext_destroy(ct
);
178 write_lock_bh(&nf_conntrack_lock
);
179 /* Expectations will have been removed in clean_from_lists,
180 * except TFTP can create an expectation on the first packet,
181 * before connection is in the list, so we need to clean here,
183 nf_ct_remove_expectations(ct
);
185 /* We overload first tuple to link into unconfirmed list. */
186 if (!nf_ct_is_confirmed(ct
)) {
187 BUG_ON(list_empty(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
));
188 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
191 NF_CT_STAT_INC(delete);
192 write_unlock_bh(&nf_conntrack_lock
);
195 nf_ct_put(ct
->master
);
197 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct
);
198 nf_conntrack_free(ct
);
201 static void death_by_timeout(unsigned long ul_conntrack
)
203 struct nf_conn
*ct
= (void *)ul_conntrack
;
204 struct nf_conn_help
*help
= nfct_help(ct
);
205 struct nf_conntrack_helper
*helper
;
209 helper
= rcu_dereference(help
->helper
);
210 if (helper
&& helper
->destroy
)
215 write_lock_bh(&nf_conntrack_lock
);
216 /* Inside lock so preempt is disabled on module removal path.
217 * Otherwise we can get spurious warnings. */
218 NF_CT_STAT_INC(delete_list
);
219 clean_from_lists(ct
);
220 write_unlock_bh(&nf_conntrack_lock
);
224 struct nf_conntrack_tuple_hash
*
225 __nf_conntrack_find(const struct nf_conntrack_tuple
*tuple
,
226 const struct nf_conn
*ignored_conntrack
)
228 struct nf_conntrack_tuple_hash
*h
;
229 unsigned int hash
= hash_conntrack(tuple
);
231 list_for_each_entry(h
, &nf_conntrack_hash
[hash
], list
) {
232 if (nf_ct_tuplehash_to_ctrack(h
) != ignored_conntrack
&&
233 nf_ct_tuple_equal(tuple
, &h
->tuple
)) {
234 NF_CT_STAT_INC(found
);
237 NF_CT_STAT_INC(searched
);
242 EXPORT_SYMBOL_GPL(__nf_conntrack_find
);
244 /* Find a connection corresponding to a tuple. */
245 struct nf_conntrack_tuple_hash
*
246 nf_conntrack_find_get(const struct nf_conntrack_tuple
*tuple
,
247 const struct nf_conn
*ignored_conntrack
)
249 struct nf_conntrack_tuple_hash
*h
;
251 read_lock_bh(&nf_conntrack_lock
);
252 h
= __nf_conntrack_find(tuple
, ignored_conntrack
);
254 atomic_inc(&nf_ct_tuplehash_to_ctrack(h
)->ct_general
.use
);
255 read_unlock_bh(&nf_conntrack_lock
);
259 EXPORT_SYMBOL_GPL(nf_conntrack_find_get
);
261 static void __nf_conntrack_hash_insert(struct nf_conn
*ct
,
263 unsigned int repl_hash
)
265 ct
->id
= ++nf_conntrack_next_id
;
266 list_add(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
,
267 &nf_conntrack_hash
[hash
]);
268 list_add(&ct
->tuplehash
[IP_CT_DIR_REPLY
].list
,
269 &nf_conntrack_hash
[repl_hash
]);
272 void nf_conntrack_hash_insert(struct nf_conn
*ct
)
274 unsigned int hash
, repl_hash
;
276 hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
277 repl_hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
279 write_lock_bh(&nf_conntrack_lock
);
280 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
281 write_unlock_bh(&nf_conntrack_lock
);
283 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert
);
285 /* Confirm a connection given skb; places it in hash table */
287 __nf_conntrack_confirm(struct sk_buff
**pskb
)
289 unsigned int hash
, repl_hash
;
290 struct nf_conntrack_tuple_hash
*h
;
292 struct nf_conn_help
*help
;
293 enum ip_conntrack_info ctinfo
;
295 ct
= nf_ct_get(*pskb
, &ctinfo
);
297 /* ipt_REJECT uses nf_conntrack_attach to attach related
298 ICMP/TCP RST packets in other direction. Actual packet
299 which created connection will be IP_CT_NEW or for an
300 expected connection, IP_CT_RELATED. */
301 if (CTINFO2DIR(ctinfo
) != IP_CT_DIR_ORIGINAL
)
304 hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
305 repl_hash
= hash_conntrack(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
307 /* We're not in hash table, and we refuse to set up related
308 connections for unconfirmed conns. But packet copies and
309 REJECT will give spurious warnings here. */
310 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
312 /* No external references means noone else could have
314 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
315 DEBUGP("Confirming conntrack %p\n", ct
);
317 write_lock_bh(&nf_conntrack_lock
);
319 /* See if there's one in the list already, including reverse:
320 NAT could have grabbed it without realizing, since we're
321 not in the hash. If there is, we lost race. */
322 list_for_each_entry(h
, &nf_conntrack_hash
[hash
], list
)
323 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
,
326 list_for_each_entry(h
, &nf_conntrack_hash
[repl_hash
], list
)
327 if (nf_ct_tuple_equal(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
,
331 /* Remove from unconfirmed list */
332 list_del(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
);
334 __nf_conntrack_hash_insert(ct
, hash
, repl_hash
);
335 /* Timer relative to confirmation time, not original
336 setting time, otherwise we'd get timer wrap in
337 weird delay cases. */
338 ct
->timeout
.expires
+= jiffies
;
339 add_timer(&ct
->timeout
);
340 atomic_inc(&ct
->ct_general
.use
);
341 set_bit(IPS_CONFIRMED_BIT
, &ct
->status
);
342 NF_CT_STAT_INC(insert
);
343 write_unlock_bh(&nf_conntrack_lock
);
344 help
= nfct_help(ct
);
345 if (help
&& help
->helper
)
346 nf_conntrack_event_cache(IPCT_HELPER
, *pskb
);
347 #ifdef CONFIG_NF_NAT_NEEDED
348 if (test_bit(IPS_SRC_NAT_DONE_BIT
, &ct
->status
) ||
349 test_bit(IPS_DST_NAT_DONE_BIT
, &ct
->status
))
350 nf_conntrack_event_cache(IPCT_NATINFO
, *pskb
);
352 nf_conntrack_event_cache(master_ct(ct
) ?
353 IPCT_RELATED
: IPCT_NEW
, *pskb
);
357 NF_CT_STAT_INC(insert_failed
);
358 write_unlock_bh(&nf_conntrack_lock
);
361 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm
);
363 /* Returns true if a connection correspondings to the tuple (required
366 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple
*tuple
,
367 const struct nf_conn
*ignored_conntrack
)
369 struct nf_conntrack_tuple_hash
*h
;
371 read_lock_bh(&nf_conntrack_lock
);
372 h
= __nf_conntrack_find(tuple
, ignored_conntrack
);
373 read_unlock_bh(&nf_conntrack_lock
);
377 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken
);
379 /* There's a small race here where we may free a just-assured
380 connection. Too bad: we're in trouble anyway. */
381 static int early_drop(struct list_head
*chain
)
383 /* Traverse backwards: gives us oldest, which is roughly LRU */
384 struct nf_conntrack_tuple_hash
*h
;
385 struct nf_conn
*ct
= NULL
, *tmp
;
388 read_lock_bh(&nf_conntrack_lock
);
389 list_for_each_entry_reverse(h
, chain
, list
) {
390 tmp
= nf_ct_tuplehash_to_ctrack(h
);
391 if (!test_bit(IPS_ASSURED_BIT
, &tmp
->status
)) {
393 atomic_inc(&ct
->ct_general
.use
);
397 read_unlock_bh(&nf_conntrack_lock
);
402 if (del_timer(&ct
->timeout
)) {
403 death_by_timeout((unsigned long)ct
);
405 NF_CT_STAT_INC_ATOMIC(early_drop
);
411 struct nf_conn
*nf_conntrack_alloc(const struct nf_conntrack_tuple
*orig
,
412 const struct nf_conntrack_tuple
*repl
)
414 struct nf_conn
*conntrack
= NULL
;
416 if (unlikely(!nf_conntrack_hash_rnd_initted
)) {
417 get_random_bytes(&nf_conntrack_hash_rnd
, 4);
418 nf_conntrack_hash_rnd_initted
= 1;
421 /* We don't want any race condition at early drop stage */
422 atomic_inc(&nf_conntrack_count
);
425 && atomic_read(&nf_conntrack_count
) > nf_conntrack_max
) {
426 unsigned int hash
= hash_conntrack(orig
);
427 /* Try dropping from this hash chain. */
428 if (!early_drop(&nf_conntrack_hash
[hash
])) {
429 atomic_dec(&nf_conntrack_count
);
432 "nf_conntrack: table full, dropping"
434 return ERR_PTR(-ENOMEM
);
438 conntrack
= kmem_cache_zalloc(nf_conntrack_cachep
, GFP_ATOMIC
);
439 if (conntrack
== NULL
) {
440 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack.\n");
441 atomic_dec(&nf_conntrack_count
);
442 return ERR_PTR(-ENOMEM
);
445 atomic_set(&conntrack
->ct_general
.use
, 1);
446 conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
= *orig
;
447 conntrack
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *repl
;
448 /* Don't set timer yet: wait for confirmation */
449 setup_timer(&conntrack
->timeout
, death_by_timeout
,
450 (unsigned long)conntrack
);
454 EXPORT_SYMBOL_GPL(nf_conntrack_alloc
);
456 void nf_conntrack_free(struct nf_conn
*conntrack
)
458 nf_ct_ext_free(conntrack
);
459 kmem_cache_free(nf_conntrack_cachep
, conntrack
);
460 atomic_dec(&nf_conntrack_count
);
462 EXPORT_SYMBOL_GPL(nf_conntrack_free
);
464 /* Allocate a new conntrack: we return -ENOMEM if classification
465 failed due to stress. Otherwise it really is unclassifiable. */
466 static struct nf_conntrack_tuple_hash
*
467 init_conntrack(const struct nf_conntrack_tuple
*tuple
,
468 struct nf_conntrack_l3proto
*l3proto
,
469 struct nf_conntrack_l4proto
*l4proto
,
471 unsigned int dataoff
)
473 struct nf_conn
*conntrack
;
474 struct nf_conn_help
*help
;
475 struct nf_conntrack_tuple repl_tuple
;
476 struct nf_conntrack_expect
*exp
;
478 if (!nf_ct_invert_tuple(&repl_tuple
, tuple
, l3proto
, l4proto
)) {
479 DEBUGP("Can't invert tuple.\n");
483 conntrack
= nf_conntrack_alloc(tuple
, &repl_tuple
);
484 if (conntrack
== NULL
|| IS_ERR(conntrack
)) {
485 DEBUGP("Can't allocate conntrack.\n");
486 return (struct nf_conntrack_tuple_hash
*)conntrack
;
489 if (!l4proto
->new(conntrack
, skb
, dataoff
)) {
490 nf_conntrack_free(conntrack
);
491 DEBUGP("init conntrack: can't track with proto module\n");
495 write_lock_bh(&nf_conntrack_lock
);
496 exp
= find_expectation(tuple
);
498 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
500 /* Welcome, Mr. Bond. We've been expecting you... */
501 __set_bit(IPS_EXPECTED_BIT
, &conntrack
->status
);
502 conntrack
->master
= exp
->master
;
504 help
= nf_ct_ext_add(conntrack
, NF_CT_EXT_HELPER
,
507 rcu_assign_pointer(help
->helper
, exp
->helper
);
509 DEBUGP("failed to add helper extension area");
512 #ifdef CONFIG_NF_CONNTRACK_MARK
513 conntrack
->mark
= exp
->master
->mark
;
515 #ifdef CONFIG_NF_CONNTRACK_SECMARK
516 conntrack
->secmark
= exp
->master
->secmark
;
518 nf_conntrack_get(&conntrack
->master
->ct_general
);
519 NF_CT_STAT_INC(expect_new
);
521 struct nf_conntrack_helper
*helper
;
523 helper
= __nf_ct_helper_find(&repl_tuple
);
525 help
= nf_ct_ext_add(conntrack
, NF_CT_EXT_HELPER
,
528 /* not in hash table yet, so not strictly
530 rcu_assign_pointer(help
->helper
, helper
);
532 DEBUGP("failed to add helper extension area");
537 /* Overload tuple linked list to put us in unconfirmed list. */
538 list_add(&conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
].list
, &unconfirmed
);
540 write_unlock_bh(&nf_conntrack_lock
);
544 exp
->expectfn(conntrack
, exp
);
545 nf_conntrack_expect_put(exp
);
548 return &conntrack
->tuplehash
[IP_CT_DIR_ORIGINAL
];
551 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
552 static inline struct nf_conn
*
553 resolve_normal_ct(struct sk_buff
*skb
,
554 unsigned int dataoff
,
557 struct nf_conntrack_l3proto
*l3proto
,
558 struct nf_conntrack_l4proto
*l4proto
,
560 enum ip_conntrack_info
*ctinfo
)
562 struct nf_conntrack_tuple tuple
;
563 struct nf_conntrack_tuple_hash
*h
;
566 if (!nf_ct_get_tuple(skb
, skb_network_offset(skb
),
567 dataoff
, l3num
, protonum
, &tuple
, l3proto
,
569 DEBUGP("resolve_normal_ct: Can't get tuple\n");
573 /* look for tuple match */
574 h
= nf_conntrack_find_get(&tuple
, NULL
);
576 h
= init_conntrack(&tuple
, l3proto
, l4proto
, skb
, dataoff
);
582 ct
= nf_ct_tuplehash_to_ctrack(h
);
584 /* It exists; we have (non-exclusive) reference. */
585 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
) {
586 *ctinfo
= IP_CT_ESTABLISHED
+ IP_CT_IS_REPLY
;
587 /* Please set reply bit if this packet OK */
590 /* Once we've had two way comms, always ESTABLISHED. */
591 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
592 DEBUGP("nf_conntrack_in: normal packet for %p\n", ct
);
593 *ctinfo
= IP_CT_ESTABLISHED
;
594 } else if (test_bit(IPS_EXPECTED_BIT
, &ct
->status
)) {
595 DEBUGP("nf_conntrack_in: related packet for %p\n", ct
);
596 *ctinfo
= IP_CT_RELATED
;
598 DEBUGP("nf_conntrack_in: new packet for %p\n", ct
);
603 skb
->nfct
= &ct
->ct_general
;
604 skb
->nfctinfo
= *ctinfo
;
609 nf_conntrack_in(int pf
, unsigned int hooknum
, struct sk_buff
**pskb
)
612 enum ip_conntrack_info ctinfo
;
613 struct nf_conntrack_l3proto
*l3proto
;
614 struct nf_conntrack_l4proto
*l4proto
;
615 unsigned int dataoff
;
620 /* Previously seen (loopback or untracked)? Ignore. */
622 NF_CT_STAT_INC_ATOMIC(ignore
);
626 /* rcu_read_lock()ed by nf_hook_slow */
627 l3proto
= __nf_ct_l3proto_find((u_int16_t
)pf
);
629 if ((ret
= l3proto
->prepare(pskb
, hooknum
, &dataoff
, &protonum
)) <= 0) {
630 DEBUGP("not prepared to track yet or error occured\n");
634 l4proto
= __nf_ct_l4proto_find((u_int16_t
)pf
, protonum
);
636 /* It may be an special packet, error, unclean...
637 * inverse of the return code tells to the netfilter
638 * core what to do with the packet. */
639 if (l4proto
->error
!= NULL
&&
640 (ret
= l4proto
->error(*pskb
, dataoff
, &ctinfo
, pf
, hooknum
)) <= 0) {
641 NF_CT_STAT_INC_ATOMIC(error
);
642 NF_CT_STAT_INC_ATOMIC(invalid
);
646 ct
= resolve_normal_ct(*pskb
, dataoff
, pf
, protonum
, l3proto
, l4proto
,
647 &set_reply
, &ctinfo
);
649 /* Not valid part of a connection */
650 NF_CT_STAT_INC_ATOMIC(invalid
);
655 /* Too stressed to deal. */
656 NF_CT_STAT_INC_ATOMIC(drop
);
660 NF_CT_ASSERT((*pskb
)->nfct
);
662 ret
= l4proto
->packet(ct
, *pskb
, dataoff
, ctinfo
, pf
, hooknum
);
664 /* Invalid: inverse of the return code tells
665 * the netfilter core what to do */
666 DEBUGP("nf_conntrack_in: Can't track with proto module\n");
667 nf_conntrack_put((*pskb
)->nfct
);
668 (*pskb
)->nfct
= NULL
;
669 NF_CT_STAT_INC_ATOMIC(invalid
);
673 if (set_reply
&& !test_and_set_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
))
674 nf_conntrack_event_cache(IPCT_STATUS
, *pskb
);
678 EXPORT_SYMBOL_GPL(nf_conntrack_in
);
680 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple
*inverse
,
681 const struct nf_conntrack_tuple
*orig
)
686 ret
= nf_ct_invert_tuple(inverse
, orig
,
687 __nf_ct_l3proto_find(orig
->src
.l3num
),
688 __nf_ct_l4proto_find(orig
->src
.l3num
,
689 orig
->dst
.protonum
));
693 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr
);
695 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
696 implicitly racy: see __nf_conntrack_confirm */
697 void nf_conntrack_alter_reply(struct nf_conn
*ct
,
698 const struct nf_conntrack_tuple
*newreply
)
700 struct nf_conn_help
*help
= nfct_help(ct
);
701 struct nf_conntrack_helper
*helper
;
703 write_lock_bh(&nf_conntrack_lock
);
704 /* Should be unconfirmed, so not in hash table yet */
705 NF_CT_ASSERT(!nf_ct_is_confirmed(ct
));
707 DEBUGP("Altering reply tuple of %p to ", ct
);
708 NF_CT_DUMP_TUPLE(newreply
);
710 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
= *newreply
;
711 if (ct
->master
|| (help
&& help
->expecting
!= 0))
714 helper
= __nf_ct_helper_find(newreply
);
715 if (helper
== NULL
) {
717 rcu_assign_pointer(help
->helper
, NULL
);
722 help
= nf_ct_ext_add(ct
, NF_CT_EXT_HELPER
, GFP_ATOMIC
);
724 DEBUGP("failed to add helper extension area");
728 memset(&help
->help
, 0, sizeof(help
->help
));
731 rcu_assign_pointer(help
->helper
, helper
);
733 write_unlock_bh(&nf_conntrack_lock
);
735 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply
);
737 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
738 void __nf_ct_refresh_acct(struct nf_conn
*ct
,
739 enum ip_conntrack_info ctinfo
,
740 const struct sk_buff
*skb
,
741 unsigned long extra_jiffies
,
746 NF_CT_ASSERT(ct
->timeout
.data
== (unsigned long)ct
);
749 write_lock_bh(&nf_conntrack_lock
);
751 /* Only update if this is not a fixed timeout */
752 if (test_bit(IPS_FIXED_TIMEOUT_BIT
, &ct
->status
)) {
753 write_unlock_bh(&nf_conntrack_lock
);
757 /* If not in hash table, timer will not be active yet */
758 if (!nf_ct_is_confirmed(ct
)) {
759 ct
->timeout
.expires
= extra_jiffies
;
760 event
= IPCT_REFRESH
;
762 unsigned long newtime
= jiffies
+ extra_jiffies
;
764 /* Only update the timeout if the new timeout is at least
765 HZ jiffies from the old timeout. Need del_timer for race
766 avoidance (may already be dying). */
767 if (newtime
- ct
->timeout
.expires
>= HZ
768 && del_timer(&ct
->timeout
)) {
769 ct
->timeout
.expires
= newtime
;
770 add_timer(&ct
->timeout
);
771 event
= IPCT_REFRESH
;
775 #ifdef CONFIG_NF_CT_ACCT
777 ct
->counters
[CTINFO2DIR(ctinfo
)].packets
++;
778 ct
->counters
[CTINFO2DIR(ctinfo
)].bytes
+=
779 skb
->len
- skb_network_offset(skb
);
781 if ((ct
->counters
[CTINFO2DIR(ctinfo
)].packets
& 0x80000000)
782 || (ct
->counters
[CTINFO2DIR(ctinfo
)].bytes
& 0x80000000))
783 event
|= IPCT_COUNTER_FILLING
;
787 write_unlock_bh(&nf_conntrack_lock
);
789 /* must be unlocked when calling event cache */
791 nf_conntrack_event_cache(event
, skb
);
793 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct
);
795 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
797 #include <linux/netfilter/nfnetlink.h>
798 #include <linux/netfilter/nfnetlink_conntrack.h>
799 #include <linux/mutex.h>
802 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
803 * in ip_conntrack_core, since we don't want the protocols to autoload
804 * or depend on ctnetlink */
805 int nf_ct_port_tuple_to_nfattr(struct sk_buff
*skb
,
806 const struct nf_conntrack_tuple
*tuple
)
808 NFA_PUT(skb
, CTA_PROTO_SRC_PORT
, sizeof(u_int16_t
),
809 &tuple
->src
.u
.tcp
.port
);
810 NFA_PUT(skb
, CTA_PROTO_DST_PORT
, sizeof(u_int16_t
),
811 &tuple
->dst
.u
.tcp
.port
);
817 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr
);
819 static const size_t cta_min_proto
[CTA_PROTO_MAX
] = {
820 [CTA_PROTO_SRC_PORT
-1] = sizeof(u_int16_t
),
821 [CTA_PROTO_DST_PORT
-1] = sizeof(u_int16_t
)
824 int nf_ct_port_nfattr_to_tuple(struct nfattr
*tb
[],
825 struct nf_conntrack_tuple
*t
)
827 if (!tb
[CTA_PROTO_SRC_PORT
-1] || !tb
[CTA_PROTO_DST_PORT
-1])
830 if (nfattr_bad_size(tb
, CTA_PROTO_MAX
, cta_min_proto
))
833 t
->src
.u
.tcp
.port
= *(__be16
*)NFA_DATA(tb
[CTA_PROTO_SRC_PORT
-1]);
834 t
->dst
.u
.tcp
.port
= *(__be16
*)NFA_DATA(tb
[CTA_PROTO_DST_PORT
-1]);
838 EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple
);
841 /* Used by ipt_REJECT and ip6t_REJECT. */
842 void __nf_conntrack_attach(struct sk_buff
*nskb
, struct sk_buff
*skb
)
845 enum ip_conntrack_info ctinfo
;
847 /* This ICMP is in reverse direction to the packet which caused it */
848 ct
= nf_ct_get(skb
, &ctinfo
);
849 if (CTINFO2DIR(ctinfo
) == IP_CT_DIR_ORIGINAL
)
850 ctinfo
= IP_CT_RELATED
+ IP_CT_IS_REPLY
;
852 ctinfo
= IP_CT_RELATED
;
854 /* Attach to new skbuff, and increment count */
855 nskb
->nfct
= &ct
->ct_general
;
856 nskb
->nfctinfo
= ctinfo
;
857 nf_conntrack_get(nskb
->nfct
);
859 EXPORT_SYMBOL_GPL(__nf_conntrack_attach
);
862 do_iter(const struct nf_conntrack_tuple_hash
*i
,
863 int (*iter
)(struct nf_conn
*i
, void *data
),
866 return iter(nf_ct_tuplehash_to_ctrack(i
), data
);
869 /* Bring out ya dead! */
870 static struct nf_conn
*
871 get_next_corpse(int (*iter
)(struct nf_conn
*i
, void *data
),
872 void *data
, unsigned int *bucket
)
874 struct nf_conntrack_tuple_hash
*h
;
877 write_lock_bh(&nf_conntrack_lock
);
878 for (; *bucket
< nf_conntrack_htable_size
; (*bucket
)++) {
879 list_for_each_entry(h
, &nf_conntrack_hash
[*bucket
], list
) {
880 ct
= nf_ct_tuplehash_to_ctrack(h
);
885 list_for_each_entry(h
, &unconfirmed
, list
) {
886 ct
= nf_ct_tuplehash_to_ctrack(h
);
888 set_bit(IPS_DYING_BIT
, &ct
->status
);
890 write_unlock_bh(&nf_conntrack_lock
);
893 atomic_inc(&ct
->ct_general
.use
);
894 write_unlock_bh(&nf_conntrack_lock
);
899 nf_ct_iterate_cleanup(int (*iter
)(struct nf_conn
*i
, void *data
), void *data
)
902 unsigned int bucket
= 0;
904 while ((ct
= get_next_corpse(iter
, data
, &bucket
)) != NULL
) {
905 /* Time to push up daises... */
906 if (del_timer(&ct
->timeout
))
907 death_by_timeout((unsigned long)ct
);
908 /* ... else the timer will get him soon. */
913 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup
);
915 static int kill_all(struct nf_conn
*i
, void *data
)
920 static void free_conntrack_hash(struct list_head
*hash
, int vmalloced
, int size
)
925 free_pages((unsigned long)hash
,
926 get_order(sizeof(struct list_head
) * size
));
929 void nf_conntrack_flush(void)
931 nf_ct_iterate_cleanup(kill_all
, NULL
);
933 EXPORT_SYMBOL_GPL(nf_conntrack_flush
);
935 /* Mishearing the voices in his head, our hero wonders how he's
936 supposed to kill the mall. */
937 void nf_conntrack_cleanup(void)
939 rcu_assign_pointer(ip_ct_attach
, NULL
);
941 /* This makes sure all current packets have passed through
942 netfilter framework. Roll on, two-stage module
946 nf_ct_event_cache_flush();
948 nf_conntrack_flush();
949 if (atomic_read(&nf_conntrack_count
) != 0) {
951 goto i_see_dead_people
;
953 /* wait until all references to nf_conntrack_untracked are dropped */
954 while (atomic_read(&nf_conntrack_untracked
.ct_general
.use
) > 1)
957 rcu_assign_pointer(nf_ct_destroy
, NULL
);
959 kmem_cache_destroy(nf_conntrack_cachep
);
960 kmem_cache_destroy(nf_conntrack_expect_cachep
);
961 free_conntrack_hash(nf_conntrack_hash
, nf_conntrack_vmalloc
,
962 nf_conntrack_htable_size
);
964 nf_conntrack_proto_fini();
965 nf_conntrack_helper_fini();
968 static struct list_head
*alloc_hashtable(int *sizep
, int *vmalloced
)
970 struct list_head
*hash
;
971 unsigned int size
, i
;
975 size
= *sizep
= roundup(*sizep
, PAGE_SIZE
/ sizeof(struct list_head
));
976 hash
= (void*)__get_free_pages(GFP_KERNEL
,
977 get_order(sizeof(struct list_head
)
981 printk(KERN_WARNING
"nf_conntrack: falling back to vmalloc.\n");
982 hash
= vmalloc(sizeof(struct list_head
) * size
);
986 for (i
= 0; i
< size
; i
++)
987 INIT_LIST_HEAD(&hash
[i
]);
992 int set_hashsize(const char *val
, struct kernel_param
*kp
)
994 int i
, bucket
, hashsize
, vmalloced
;
995 int old_vmalloced
, old_size
;
997 struct list_head
*hash
, *old_hash
;
998 struct nf_conntrack_tuple_hash
*h
;
1000 /* On boot, we can set this without any fancy locking. */
1001 if (!nf_conntrack_htable_size
)
1002 return param_set_uint(val
, kp
);
1004 hashsize
= simple_strtol(val
, NULL
, 0);
1008 hash
= alloc_hashtable(&hashsize
, &vmalloced
);
1012 /* We have to rehahs for the new table anyway, so we also can
1013 * use a newrandom seed */
1014 get_random_bytes(&rnd
, 4);
1016 write_lock_bh(&nf_conntrack_lock
);
1017 for (i
= 0; i
< nf_conntrack_htable_size
; i
++) {
1018 while (!list_empty(&nf_conntrack_hash
[i
])) {
1019 h
= list_entry(nf_conntrack_hash
[i
].next
,
1020 struct nf_conntrack_tuple_hash
, list
);
1022 bucket
= __hash_conntrack(&h
->tuple
, hashsize
, rnd
);
1023 list_add_tail(&h
->list
, &hash
[bucket
]);
1026 old_size
= nf_conntrack_htable_size
;
1027 old_vmalloced
= nf_conntrack_vmalloc
;
1028 old_hash
= nf_conntrack_hash
;
1030 nf_conntrack_htable_size
= hashsize
;
1031 nf_conntrack_vmalloc
= vmalloced
;
1032 nf_conntrack_hash
= hash
;
1033 nf_conntrack_hash_rnd
= rnd
;
1034 write_unlock_bh(&nf_conntrack_lock
);
1036 free_conntrack_hash(old_hash
, old_vmalloced
, old_size
);
1040 module_param_call(hashsize
, set_hashsize
, param_get_uint
,
1041 &nf_conntrack_htable_size
, 0600);
1043 int __init
nf_conntrack_init(void)
1047 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1048 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */
1049 if (!nf_conntrack_htable_size
) {
1050 nf_conntrack_htable_size
1051 = (((num_physpages
<< PAGE_SHIFT
) / 16384)
1052 / sizeof(struct list_head
));
1053 if (num_physpages
> (1024 * 1024 * 1024 / PAGE_SIZE
))
1054 nf_conntrack_htable_size
= 8192;
1055 if (nf_conntrack_htable_size
< 16)
1056 nf_conntrack_htable_size
= 16;
1058 nf_conntrack_hash
= alloc_hashtable(&nf_conntrack_htable_size
,
1059 &nf_conntrack_vmalloc
);
1060 if (!nf_conntrack_hash
) {
1061 printk(KERN_ERR
"Unable to create nf_conntrack_hash\n");
1065 nf_conntrack_max
= 8 * nf_conntrack_htable_size
;
1067 printk("nf_conntrack version %s (%u buckets, %d max)\n",
1068 NF_CONNTRACK_VERSION
, nf_conntrack_htable_size
,
1071 nf_conntrack_cachep
= kmem_cache_create("nf_conntrack",
1072 sizeof(struct nf_conn
),
1074 if (!nf_conntrack_cachep
) {
1075 printk(KERN_ERR
"Unable to create nf_conn slab cache\n");
1079 nf_conntrack_expect_cachep
= kmem_cache_create("nf_conntrack_expect",
1080 sizeof(struct nf_conntrack_expect
),
1082 if (!nf_conntrack_expect_cachep
) {
1083 printk(KERN_ERR
"Unable to create nf_expect slab cache\n");
1084 goto err_free_conntrack_slab
;
1087 ret
= nf_conntrack_proto_init();
1089 goto out_free_expect_slab
;
1091 ret
= nf_conntrack_helper_init();
1093 goto out_fini_proto
;
1095 /* For use by REJECT target */
1096 rcu_assign_pointer(ip_ct_attach
, __nf_conntrack_attach
);
1097 rcu_assign_pointer(nf_ct_destroy
, destroy_conntrack
);
1099 /* Set up fake conntrack:
1100 - to never be deleted, not in any hashes */
1101 atomic_set(&nf_conntrack_untracked
.ct_general
.use
, 1);
1102 /* - and look it like as a confirmed connection */
1103 set_bit(IPS_CONFIRMED_BIT
, &nf_conntrack_untracked
.status
);
1108 nf_conntrack_proto_fini();
1109 out_free_expect_slab
:
1110 kmem_cache_destroy(nf_conntrack_expect_cachep
);
1111 err_free_conntrack_slab
:
1112 kmem_cache_destroy(nf_conntrack_cachep
);
1114 free_conntrack_hash(nf_conntrack_hash
, nf_conntrack_vmalloc
,
1115 nf_conntrack_htable_size
);