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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>
31#include <linux/mm.h>
32
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>
40
41#define NF_CONNTRACK_VERSION "0.5.0"
42
43DEFINE_RWLOCK(nf_conntrack_lock);
44EXPORT_SYMBOL_GPL(nf_conntrack_lock);
45
46
47atomic_t nf_conntrack_count = ATOMIC_INIT(0);
48EXPORT_SYMBOL_GPL(nf_conntrack_count);
49
50unsigned int nf_conntrack_htable_size __read_mostly;
51EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
52
53int nf_conntrack_max __read_mostly;
54EXPORT_SYMBOL_GPL(nf_conntrack_max);
55
56struct hlist_head *nf_conntrack_hash __read_mostly;
57EXPORT_SYMBOL_GPL(nf_conntrack_hash);
58
59struct nf_conn nf_conntrack_untracked __read_mostly;
60EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
61
62unsigned int nf_ct_log_invalid __read_mostly;
63HLIST_HEAD(unconfirmed);
64static int nf_conntrack_vmalloc __read_mostly;
65static struct kmem_cache *nf_conntrack_cachep __read_mostly;
66
67DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
68EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
69
70static int nf_conntrack_hash_rnd_initted;
71static unsigned int nf_conntrack_hash_rnd;
72
73static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
74 unsigned int size, unsigned int rnd)
75{
76 unsigned int a, b;
77
78 a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all),
79 (tuple->src.l3num << 16) | tuple->dst.protonum);
80 b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
81 ((__force __u16)tuple->src.u.all << 16) |
82 (__force __u16)tuple->dst.u.all);
83
84 return jhash_2words(a, b, rnd) % size;
85}
86
87static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
88{
89 return __hash_conntrack(tuple, nf_conntrack_htable_size,
90 nf_conntrack_hash_rnd);
91}
92
93int
94nf_ct_get_tuple(const struct sk_buff *skb,
95 unsigned int nhoff,
96 unsigned int dataoff,
97 u_int16_t l3num,
98 u_int8_t protonum,
99 struct nf_conntrack_tuple *tuple,
100 const struct nf_conntrack_l3proto *l3proto,
101 const struct nf_conntrack_l4proto *l4proto)
102{
103 NF_CT_TUPLE_U_BLANK(tuple);
104
105 tuple->src.l3num = l3num;
106 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
107 return 0;
108
109 tuple->dst.protonum = protonum;
110 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
111
112 return l4proto->pkt_to_tuple(skb, dataoff, tuple);
113}
114EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
115
116int nf_ct_get_tuplepr(const struct sk_buff *skb,
117 unsigned int nhoff,
118 u_int16_t l3num,
119 struct nf_conntrack_tuple *tuple)
120{
121 struct nf_conntrack_l3proto *l3proto;
122 struct nf_conntrack_l4proto *l4proto;
123 unsigned int protoff;
124 u_int8_t protonum;
125 int ret;
126
127 rcu_read_lock();
128
129 l3proto = __nf_ct_l3proto_find(l3num);
130 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
131 if (ret != NF_ACCEPT) {
132 rcu_read_unlock();
133 return 0;
134 }
135
136 l4proto = __nf_ct_l4proto_find(l3num, protonum);
137
138 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
139 l3proto, l4proto);
140
141 rcu_read_unlock();
142 return ret;
143}
144EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
145
146int
147nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
148 const struct nf_conntrack_tuple *orig,
149 const struct nf_conntrack_l3proto *l3proto,
150 const struct nf_conntrack_l4proto *l4proto)
151{
152 NF_CT_TUPLE_U_BLANK(inverse);
153
154 inverse->src.l3num = orig->src.l3num;
155 if (l3proto->invert_tuple(inverse, orig) == 0)
156 return 0;
157
158 inverse->dst.dir = !orig->dst.dir;
159
160 inverse->dst.protonum = orig->dst.protonum;
161 return l4proto->invert_tuple(inverse, orig);
162}
163EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
164
165static void
166clean_from_lists(struct nf_conn *ct)
167{
168 pr_debug("clean_from_lists(%p)\n", ct);
169 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
170 hlist_del(&ct->tuplehash[IP_CT_DIR_REPLY].hnode);
171
172
173 nf_ct_remove_expectations(ct);
174}
175
176static void
177destroy_conntrack(struct nf_conntrack *nfct)
178{
179 struct nf_conn *ct = (struct nf_conn *)nfct;
180 struct nf_conntrack_l4proto *l4proto;
181
182 pr_debug("destroy_conntrack(%p)\n", ct);
183 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
184 NF_CT_ASSERT(!timer_pending(&ct->timeout));
185
186 nf_conntrack_event(IPCT_DESTROY, ct);
187 set_bit(IPS_DYING_BIT, &ct->status);
188
189
190
191
192 rcu_read_lock();
193 l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num,
194 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
195 if (l4proto && l4proto->destroy)
196 l4proto->destroy(ct);
197
198 nf_ct_ext_destroy(ct);
199
200 rcu_read_unlock();
201
202 write_lock_bh(&nf_conntrack_lock);
203
204
205
206
207 nf_ct_remove_expectations(ct);
208
209
210 if (!nf_ct_is_confirmed(ct)) {
211 BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode));
212 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
213 }
214
215 NF_CT_STAT_INC(delete);
216 write_unlock_bh(&nf_conntrack_lock);
217
218 if (ct->master)
219 nf_ct_put(ct->master);
220
221 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
222 nf_conntrack_free(ct);
223}
224
225static void death_by_timeout(unsigned long ul_conntrack)
226{
227 struct nf_conn *ct = (void *)ul_conntrack;
228 struct nf_conn_help *help = nfct_help(ct);
229 struct nf_conntrack_helper *helper;
230
231 if (help) {
232 rcu_read_lock();
233 helper = rcu_dereference(help->helper);
234 if (helper && helper->destroy)
235 helper->destroy(ct);
236 rcu_read_unlock();
237 }
238
239 write_lock_bh(&nf_conntrack_lock);
240
241
242 NF_CT_STAT_INC(delete_list);
243 clean_from_lists(ct);
244 write_unlock_bh(&nf_conntrack_lock);
245 nf_ct_put(ct);
246}
247
248struct nf_conntrack_tuple_hash *
249__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
250 const struct nf_conn *ignored_conntrack)
251{
252 struct nf_conntrack_tuple_hash *h;
253 struct hlist_node *n;
254 unsigned int hash = hash_conntrack(tuple);
255
256 hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) {
257 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
258 nf_ct_tuple_equal(tuple, &h->tuple)) {
259 NF_CT_STAT_INC(found);
260 return h;
261 }
262 NF_CT_STAT_INC(searched);
263 }
264
265 return NULL;
266}
267EXPORT_SYMBOL_GPL(__nf_conntrack_find);
268
269
270struct nf_conntrack_tuple_hash *
271nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
272{
273 struct nf_conntrack_tuple_hash *h;
274
275 read_lock_bh(&nf_conntrack_lock);
276 h = __nf_conntrack_find(tuple, NULL);
277 if (h)
278 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
279 read_unlock_bh(&nf_conntrack_lock);
280
281 return h;
282}
283EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
284
285static void __nf_conntrack_hash_insert(struct nf_conn *ct,
286 unsigned int hash,
287 unsigned int repl_hash)
288{
289 hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
290 &nf_conntrack_hash[hash]);
291 hlist_add_head(&ct->tuplehash[IP_CT_DIR_REPLY].hnode,
292 &nf_conntrack_hash[repl_hash]);
293}
294
295void nf_conntrack_hash_insert(struct nf_conn *ct)
296{
297 unsigned int hash, repl_hash;
298
299 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
300 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
301
302 write_lock_bh(&nf_conntrack_lock);
303 __nf_conntrack_hash_insert(ct, hash, repl_hash);
304 write_unlock_bh(&nf_conntrack_lock);
305}
306EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
307
308
309int
310__nf_conntrack_confirm(struct sk_buff *skb)
311{
312 unsigned int hash, repl_hash;
313 struct nf_conntrack_tuple_hash *h;
314 struct nf_conn *ct;
315 struct nf_conn_help *help;
316 struct hlist_node *n;
317 enum ip_conntrack_info ctinfo;
318
319 ct = nf_ct_get(skb, &ctinfo);
320
321
322
323
324
325 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
326 return NF_ACCEPT;
327
328 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
329 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
330
331
332
333
334
335
336
337
338 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
339 pr_debug("Confirming conntrack %p\n", ct);
340
341 write_lock_bh(&nf_conntrack_lock);
342
343
344
345
346 hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode)
347 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
348 &h->tuple))
349 goto out;
350 hlist_for_each_entry(h, n, &nf_conntrack_hash[repl_hash], hnode)
351 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
352 &h->tuple))
353 goto out;
354
355
356 hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode);
357
358 __nf_conntrack_hash_insert(ct, hash, repl_hash);
359
360
361
362 ct->timeout.expires += jiffies;
363 add_timer(&ct->timeout);
364 atomic_inc(&ct->ct_general.use);
365 set_bit(IPS_CONFIRMED_BIT, &ct->status);
366 NF_CT_STAT_INC(insert);
367 write_unlock_bh(&nf_conntrack_lock);
368 help = nfct_help(ct);
369 if (help && help->helper)
370 nf_conntrack_event_cache(IPCT_HELPER, skb);
371#ifdef CONFIG_NF_NAT_NEEDED
372 if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
373 test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
374 nf_conntrack_event_cache(IPCT_NATINFO, skb);
375#endif
376 nf_conntrack_event_cache(master_ct(ct) ?
377 IPCT_RELATED : IPCT_NEW, skb);
378 return NF_ACCEPT;
379
380out:
381 NF_CT_STAT_INC(insert_failed);
382 write_unlock_bh(&nf_conntrack_lock);
383 return NF_DROP;
384}
385EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
386
387
388
389int
390nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
391 const struct nf_conn *ignored_conntrack)
392{
393 struct nf_conntrack_tuple_hash *h;
394
395 read_lock_bh(&nf_conntrack_lock);
396 h = __nf_conntrack_find(tuple, ignored_conntrack);
397 read_unlock_bh(&nf_conntrack_lock);
398
399 return h != NULL;
400}
401EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
402
403#define NF_CT_EVICTION_RANGE 8
404
405
406
407static int early_drop(unsigned int hash)
408{
409
410 struct nf_conntrack_tuple_hash *h;
411 struct nf_conn *ct = NULL, *tmp;
412 struct hlist_node *n;
413 unsigned int i, cnt = 0;
414 int dropped = 0;
415
416 read_lock_bh(&nf_conntrack_lock);
417 for (i = 0; i < nf_conntrack_htable_size; i++) {
418 hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) {
419 tmp = nf_ct_tuplehash_to_ctrack(h);
420 if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
421 ct = tmp;
422 cnt++;
423 }
424 if (ct || cnt >= NF_CT_EVICTION_RANGE)
425 break;
426 hash = (hash + 1) % nf_conntrack_htable_size;
427 }
428 if (ct)
429 atomic_inc(&ct->ct_general.use);
430 read_unlock_bh(&nf_conntrack_lock);
431
432 if (!ct)
433 return dropped;
434
435 if (del_timer(&ct->timeout)) {
436 death_by_timeout((unsigned long)ct);
437 dropped = 1;
438 NF_CT_STAT_INC_ATOMIC(early_drop);
439 }
440 nf_ct_put(ct);
441 return dropped;
442}
443
444struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
445 const struct nf_conntrack_tuple *repl)
446{
447 struct nf_conn *conntrack = NULL;
448
449 if (unlikely(!nf_conntrack_hash_rnd_initted)) {
450 get_random_bytes(&nf_conntrack_hash_rnd, 4);
451 nf_conntrack_hash_rnd_initted = 1;
452 }
453
454
455 atomic_inc(&nf_conntrack_count);
456
457 if (nf_conntrack_max
458 && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
459 unsigned int hash = hash_conntrack(orig);
460 if (!early_drop(hash)) {
461 atomic_dec(&nf_conntrack_count);
462 if (net_ratelimit())
463 printk(KERN_WARNING
464 "nf_conntrack: table full, dropping"
465 " packet.\n");
466 return ERR_PTR(-ENOMEM);
467 }
468 }
469
470 conntrack = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC);
471 if (conntrack == NULL) {
472 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
473 atomic_dec(&nf_conntrack_count);
474 return ERR_PTR(-ENOMEM);
475 }
476
477 atomic_set(&conntrack->ct_general.use, 1);
478 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
479 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
480
481 setup_timer(&conntrack->timeout, death_by_timeout,
482 (unsigned long)conntrack);
483
484 return conntrack;
485}
486EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
487
488void nf_conntrack_free(struct nf_conn *conntrack)
489{
490 nf_ct_ext_free(conntrack);
491 kmem_cache_free(nf_conntrack_cachep, conntrack);
492 atomic_dec(&nf_conntrack_count);
493}
494EXPORT_SYMBOL_GPL(nf_conntrack_free);
495
496
497
498static struct nf_conntrack_tuple_hash *
499init_conntrack(const struct nf_conntrack_tuple *tuple,
500 struct nf_conntrack_l3proto *l3proto,
501 struct nf_conntrack_l4proto *l4proto,
502 struct sk_buff *skb,
503 unsigned int dataoff)
504{
505 struct nf_conn *conntrack;
506 struct nf_conn_help *help;
507 struct nf_conntrack_tuple repl_tuple;
508 struct nf_conntrack_expect *exp;
509
510 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
511 pr_debug("Can't invert tuple.\n");
512 return NULL;
513 }
514
515 conntrack = nf_conntrack_alloc(tuple, &repl_tuple);
516 if (conntrack == NULL || IS_ERR(conntrack)) {
517 pr_debug("Can't allocate conntrack.\n");
518 return (struct nf_conntrack_tuple_hash *)conntrack;
519 }
520
521 if (!l4proto->new(conntrack, skb, dataoff)) {
522 nf_conntrack_free(conntrack);
523 pr_debug("init conntrack: can't track with proto module\n");
524 return NULL;
525 }
526
527 write_lock_bh(&nf_conntrack_lock);
528 exp = nf_ct_find_expectation(tuple);
529 if (exp) {
530 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
531 conntrack, exp);
532
533 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
534 conntrack->master = exp->master;
535 if (exp->helper) {
536 help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
537 if (help)
538 rcu_assign_pointer(help->helper, exp->helper);
539 }
540
541#ifdef CONFIG_NF_CONNTRACK_MARK
542 conntrack->mark = exp->master->mark;
543#endif
544#ifdef CONFIG_NF_CONNTRACK_SECMARK
545 conntrack->secmark = exp->master->secmark;
546#endif
547 nf_conntrack_get(&conntrack->master->ct_general);
548 NF_CT_STAT_INC(expect_new);
549 } else {
550 struct nf_conntrack_helper *helper;
551
552 helper = __nf_ct_helper_find(&repl_tuple);
553 if (helper) {
554 help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC);
555 if (help)
556 rcu_assign_pointer(help->helper, helper);
557 }
558 NF_CT_STAT_INC(new);
559 }
560
561
562 hlist_add_head(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].hnode,
563 &unconfirmed);
564
565 write_unlock_bh(&nf_conntrack_lock);
566
567 if (exp) {
568 if (exp->expectfn)
569 exp->expectfn(conntrack, exp);
570 nf_ct_expect_put(exp);
571 }
572
573 return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
574}
575
576
577static inline struct nf_conn *
578resolve_normal_ct(struct sk_buff *skb,
579 unsigned int dataoff,
580 u_int16_t l3num,
581 u_int8_t protonum,
582 struct nf_conntrack_l3proto *l3proto,
583 struct nf_conntrack_l4proto *l4proto,
584 int *set_reply,
585 enum ip_conntrack_info *ctinfo)
586{
587 struct nf_conntrack_tuple tuple;
588 struct nf_conntrack_tuple_hash *h;
589 struct nf_conn *ct;
590
591 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
592 dataoff, l3num, protonum, &tuple, l3proto,
593 l4proto)) {
594 pr_debug("resolve_normal_ct: Can't get tuple\n");
595 return NULL;
596 }
597
598
599 h = nf_conntrack_find_get(&tuple);
600 if (!h) {
601 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
602 if (!h)
603 return NULL;
604 if (IS_ERR(h))
605 return (void *)h;
606 }
607 ct = nf_ct_tuplehash_to_ctrack(h);
608
609
610 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
611 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
612
613 *set_reply = 1;
614 } else {
615
616 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
617 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
618 *ctinfo = IP_CT_ESTABLISHED;
619 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
620 pr_debug("nf_conntrack_in: related packet for %p\n",
621 ct);
622 *ctinfo = IP_CT_RELATED;
623 } else {
624 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
625 *ctinfo = IP_CT_NEW;
626 }
627 *set_reply = 0;
628 }
629 skb->nfct = &ct->ct_general;
630 skb->nfctinfo = *ctinfo;
631 return ct;
632}
633
634unsigned int
635nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff *skb)
636{
637 struct nf_conn *ct;
638 enum ip_conntrack_info ctinfo;
639 struct nf_conntrack_l3proto *l3proto;
640 struct nf_conntrack_l4proto *l4proto;
641 unsigned int dataoff;
642 u_int8_t protonum;
643 int set_reply = 0;
644 int ret;
645
646
647 if (skb->nfct) {
648 NF_CT_STAT_INC_ATOMIC(ignore);
649 return NF_ACCEPT;
650 }
651
652
653 l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
654 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
655 &dataoff, &protonum);
656 if (ret <= 0) {
657 pr_debug("not prepared to track yet or error occured\n");
658 NF_CT_STAT_INC_ATOMIC(error);
659 NF_CT_STAT_INC_ATOMIC(invalid);
660 return -ret;
661 }
662
663 l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
664
665
666
667
668 if (l4proto->error != NULL &&
669 (ret = l4proto->error(skb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
670 NF_CT_STAT_INC_ATOMIC(error);
671 NF_CT_STAT_INC_ATOMIC(invalid);
672 return -ret;
673 }
674
675 ct = resolve_normal_ct(skb, dataoff, pf, protonum, l3proto, l4proto,
676 &set_reply, &ctinfo);
677 if (!ct) {
678
679 NF_CT_STAT_INC_ATOMIC(invalid);
680 return NF_ACCEPT;
681 }
682
683 if (IS_ERR(ct)) {
684
685 NF_CT_STAT_INC_ATOMIC(drop);
686 return NF_DROP;
687 }
688
689 NF_CT_ASSERT(skb->nfct);
690
691 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
692 if (ret < 0) {
693
694
695 pr_debug("nf_conntrack_in: Can't track with proto module\n");
696 nf_conntrack_put(skb->nfct);
697 skb->nfct = NULL;
698 NF_CT_STAT_INC_ATOMIC(invalid);
699 return -ret;
700 }
701
702 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
703 nf_conntrack_event_cache(IPCT_STATUS, skb);
704
705 return ret;
706}
707EXPORT_SYMBOL_GPL(nf_conntrack_in);
708
709int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
710 const struct nf_conntrack_tuple *orig)
711{
712 int ret;
713
714 rcu_read_lock();
715 ret = nf_ct_invert_tuple(inverse, orig,
716 __nf_ct_l3proto_find(orig->src.l3num),
717 __nf_ct_l4proto_find(orig->src.l3num,
718 orig->dst.protonum));
719 rcu_read_unlock();
720 return ret;
721}
722EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
723
724
725
726void nf_conntrack_alter_reply(struct nf_conn *ct,
727 const struct nf_conntrack_tuple *newreply)
728{
729 struct nf_conn_help *help = nfct_help(ct);
730 struct nf_conntrack_helper *helper;
731
732 write_lock_bh(&nf_conntrack_lock);
733
734 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
735
736 pr_debug("Altering reply tuple of %p to ", ct);
737 NF_CT_DUMP_TUPLE(newreply);
738
739 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
740 if (ct->master || (help && help->expecting != 0))
741 goto out;
742
743 helper = __nf_ct_helper_find(newreply);
744 if (helper == NULL) {
745 if (help)
746 rcu_assign_pointer(help->helper, NULL);
747 goto out;
748 }
749
750 if (help == NULL) {
751 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
752 if (help == NULL)
753 goto out;
754 } else {
755 memset(&help->help, 0, sizeof(help->help));
756 }
757
758 rcu_assign_pointer(help->helper, helper);
759out:
760 write_unlock_bh(&nf_conntrack_lock);
761}
762EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
763
764
765void __nf_ct_refresh_acct(struct nf_conn *ct,
766 enum ip_conntrack_info ctinfo,
767 const struct sk_buff *skb,
768 unsigned long extra_jiffies,
769 int do_acct)
770{
771 int event = 0;
772
773 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
774 NF_CT_ASSERT(skb);
775
776 write_lock_bh(&nf_conntrack_lock);
777
778
779 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
780 write_unlock_bh(&nf_conntrack_lock);
781 return;
782 }
783
784
785 if (!nf_ct_is_confirmed(ct)) {
786 ct->timeout.expires = extra_jiffies;
787 event = IPCT_REFRESH;
788 } else {
789 unsigned long newtime = jiffies + extra_jiffies;
790
791
792
793
794 if (newtime - ct->timeout.expires >= HZ
795 && del_timer(&ct->timeout)) {
796 ct->timeout.expires = newtime;
797 add_timer(&ct->timeout);
798 event = IPCT_REFRESH;
799 }
800 }
801
802#ifdef CONFIG_NF_CT_ACCT
803 if (do_acct) {
804 ct->counters[CTINFO2DIR(ctinfo)].packets++;
805 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
806 skb->len - skb_network_offset(skb);
807
808 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
809 || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
810 event |= IPCT_COUNTER_FILLING;
811 }
812#endif
813
814 write_unlock_bh(&nf_conntrack_lock);
815
816
817 if (event)
818 nf_conntrack_event_cache(event, skb);
819}
820EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
821
822#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
823
824#include <linux/netfilter/nfnetlink.h>
825#include <linux/netfilter/nfnetlink_conntrack.h>
826#include <linux/mutex.h>
827
828
829
830
831int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
832 const struct nf_conntrack_tuple *tuple)
833{
834 NLA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
835 &tuple->src.u.tcp.port);
836 NLA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
837 &tuple->dst.u.tcp.port);
838 return 0;
839
840nla_put_failure:
841 return -1;
842}
843EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
844
845const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
846 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
847 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
848};
849EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
850
851int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
852 struct nf_conntrack_tuple *t)
853{
854 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
855 return -EINVAL;
856
857 t->src.u.tcp.port = *(__be16 *)nla_data(tb[CTA_PROTO_SRC_PORT]);
858 t->dst.u.tcp.port = *(__be16 *)nla_data(tb[CTA_PROTO_DST_PORT]);
859
860 return 0;
861}
862EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
863#endif
864
865
866void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
867{
868 struct nf_conn *ct;
869 enum ip_conntrack_info ctinfo;
870
871
872 ct = nf_ct_get(skb, &ctinfo);
873 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
874 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
875 else
876 ctinfo = IP_CT_RELATED;
877
878
879 nskb->nfct = &ct->ct_general;
880 nskb->nfctinfo = ctinfo;
881 nf_conntrack_get(nskb->nfct);
882}
883EXPORT_SYMBOL_GPL(__nf_conntrack_attach);
884
885static inline int
886do_iter(const struct nf_conntrack_tuple_hash *i,
887 int (*iter)(struct nf_conn *i, void *data),
888 void *data)
889{
890 return iter(nf_ct_tuplehash_to_ctrack(i), data);
891}
892
893
894static struct nf_conn *
895get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
896 void *data, unsigned int *bucket)
897{
898 struct nf_conntrack_tuple_hash *h;
899 struct nf_conn *ct;
900 struct hlist_node *n;
901
902 write_lock_bh(&nf_conntrack_lock);
903 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
904 hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) {
905 ct = nf_ct_tuplehash_to_ctrack(h);
906 if (iter(ct, data))
907 goto found;
908 }
909 }
910 hlist_for_each_entry(h, n, &unconfirmed, hnode) {
911 ct = nf_ct_tuplehash_to_ctrack(h);
912 if (iter(ct, data))
913 set_bit(IPS_DYING_BIT, &ct->status);
914 }
915 write_unlock_bh(&nf_conntrack_lock);
916 return NULL;
917found:
918 atomic_inc(&ct->ct_general.use);
919 write_unlock_bh(&nf_conntrack_lock);
920 return ct;
921}
922
923void
924nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
925{
926 struct nf_conn *ct;
927 unsigned int bucket = 0;
928
929 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
930
931 if (del_timer(&ct->timeout))
932 death_by_timeout((unsigned long)ct);
933
934
935 nf_ct_put(ct);
936 }
937}
938EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
939
940static int kill_all(struct nf_conn *i, void *data)
941{
942 return 1;
943}
944
945void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, int size)
946{
947 if (vmalloced)
948 vfree(hash);
949 else
950 free_pages((unsigned long)hash,
951 get_order(sizeof(struct hlist_head) * size));
952}
953EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
954
955void nf_conntrack_flush(void)
956{
957 nf_ct_iterate_cleanup(kill_all, NULL);
958}
959EXPORT_SYMBOL_GPL(nf_conntrack_flush);
960
961
962
963void nf_conntrack_cleanup(void)
964{
965 rcu_assign_pointer(ip_ct_attach, NULL);
966
967
968
969
970 synchronize_net();
971
972 nf_ct_event_cache_flush();
973 i_see_dead_people:
974 nf_conntrack_flush();
975 if (atomic_read(&nf_conntrack_count) != 0) {
976 schedule();
977 goto i_see_dead_people;
978 }
979
980 while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
981 schedule();
982
983 rcu_assign_pointer(nf_ct_destroy, NULL);
984
985 kmem_cache_destroy(nf_conntrack_cachep);
986 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
987 nf_conntrack_htable_size);
988
989 nf_conntrack_proto_fini();
990 nf_conntrack_helper_fini();
991 nf_conntrack_expect_fini();
992}
993
994struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced)
995{
996 struct hlist_head *hash;
997 unsigned int size, i;
998
999 *vmalloced = 0;
1000
1001 size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head));
1002 hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN,
1003 get_order(sizeof(struct hlist_head)
1004 * size));
1005 if (!hash) {
1006 *vmalloced = 1;
1007 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1008 hash = vmalloc(sizeof(struct hlist_head) * size);
1009 }
1010
1011 if (hash)
1012 for (i = 0; i < size; i++)
1013 INIT_HLIST_HEAD(&hash[i]);
1014
1015 return hash;
1016}
1017EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1018
1019int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1020{
1021 int i, bucket, hashsize, vmalloced;
1022 int old_vmalloced, old_size;
1023 int rnd;
1024 struct hlist_head *hash, *old_hash;
1025 struct nf_conntrack_tuple_hash *h;
1026
1027
1028 if (!nf_conntrack_htable_size)
1029 return param_set_uint(val, kp);
1030
1031 hashsize = simple_strtol(val, NULL, 0);
1032 if (!hashsize)
1033 return -EINVAL;
1034
1035 hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced);
1036 if (!hash)
1037 return -ENOMEM;
1038
1039
1040
1041 get_random_bytes(&rnd, 4);
1042
1043 write_lock_bh(&nf_conntrack_lock);
1044 for (i = 0; i < nf_conntrack_htable_size; i++) {
1045 while (!hlist_empty(&nf_conntrack_hash[i])) {
1046 h = hlist_entry(nf_conntrack_hash[i].first,
1047 struct nf_conntrack_tuple_hash, hnode);
1048 hlist_del(&h->hnode);
1049 bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1050 hlist_add_head(&h->hnode, &hash[bucket]);
1051 }
1052 }
1053 old_size = nf_conntrack_htable_size;
1054 old_vmalloced = nf_conntrack_vmalloc;
1055 old_hash = nf_conntrack_hash;
1056
1057 nf_conntrack_htable_size = hashsize;
1058 nf_conntrack_vmalloc = vmalloced;
1059 nf_conntrack_hash = hash;
1060 nf_conntrack_hash_rnd = rnd;
1061 write_unlock_bh(&nf_conntrack_lock);
1062
1063 nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1064 return 0;
1065}
1066EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1067
1068module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1069 &nf_conntrack_htable_size, 0600);
1070
1071int __init nf_conntrack_init(void)
1072{
1073 int max_factor = 8;
1074 int ret;
1075
1076
1077
1078 if (!nf_conntrack_htable_size) {
1079 nf_conntrack_htable_size
1080 = (((num_physpages << PAGE_SHIFT) / 16384)
1081 / sizeof(struct hlist_head));
1082 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1083 nf_conntrack_htable_size = 16384;
1084 if (nf_conntrack_htable_size < 32)
1085 nf_conntrack_htable_size = 32;
1086
1087
1088
1089
1090
1091 max_factor = 4;
1092 }
1093 nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1094 &nf_conntrack_vmalloc);
1095 if (!nf_conntrack_hash) {
1096 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1097 goto err_out;
1098 }
1099
1100 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1101
1102 printk("nf_conntrack version %s (%u buckets, %d max)\n",
1103 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1104 nf_conntrack_max);
1105
1106 nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1107 sizeof(struct nf_conn),
1108 0, 0, NULL);
1109 if (!nf_conntrack_cachep) {
1110 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1111 goto err_free_hash;
1112 }
1113
1114 ret = nf_conntrack_proto_init();
1115 if (ret < 0)
1116 goto err_free_conntrack_slab;
1117
1118 ret = nf_conntrack_expect_init();
1119 if (ret < 0)
1120 goto out_fini_proto;
1121
1122 ret = nf_conntrack_helper_init();
1123 if (ret < 0)
1124 goto out_fini_expect;
1125
1126
1127 rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach);
1128 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1129
1130
1131
1132 atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1133
1134 set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1135
1136 return ret;
1137
1138out_fini_expect:
1139 nf_conntrack_expect_fini();
1140out_fini_proto:
1141 nf_conntrack_proto_fini();
1142err_free_conntrack_slab:
1143 kmem_cache_destroy(nf_conntrack_cachep);
1144err_free_hash:
1145 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
1146 nf_conntrack_htable_size);
1147err_out:
1148 return -ENOMEM;
1149}
1150