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15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
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>
35#include <linux/mm.h>
36#include <linux/nsproxy.h>
37#include <linux/rculist_nulls.h>
38
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>
58
59#define NF_CONNTRACK_VERSION "0.5.0"
60
61int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
62 enum nf_nat_manip_type manip,
63 const struct nlattr *attr) __read_mostly;
64EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
65
66__cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
67EXPORT_SYMBOL_GPL(nf_conntrack_locks);
68
69__cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
70EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
71
72struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
73EXPORT_SYMBOL_GPL(nf_conntrack_hash);
74
75struct conntrack_gc_work {
76 struct delayed_work dwork;
77 u32 last_bucket;
78 bool exiting;
79 long next_gc_run;
80};
81
82static __read_mostly struct kmem_cache *nf_conntrack_cachep;
83static __read_mostly spinlock_t nf_conntrack_locks_all_lock;
84static __read_mostly DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
85static __read_mostly bool nf_conntrack_locks_all;
86
87
88#define GC_MAX_BUCKETS_DIV 128u
89
90#define GC_MAX_SCAN_JIFFIES (16u * HZ)
91
92#define GC_EVICT_RATIO 50u
93
94static struct conntrack_gc_work conntrack_gc_work;
95
96void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
97{
98 spin_lock(lock);
99 while (unlikely(nf_conntrack_locks_all)) {
100 spin_unlock(lock);
101
102
103
104
105
106
107 smp_rmb();
108 spin_unlock_wait(&nf_conntrack_locks_all_lock);
109 spin_lock(lock);
110 }
111}
112EXPORT_SYMBOL_GPL(nf_conntrack_lock);
113
114static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
115{
116 h1 %= CONNTRACK_LOCKS;
117 h2 %= CONNTRACK_LOCKS;
118 spin_unlock(&nf_conntrack_locks[h1]);
119 if (h1 != h2)
120 spin_unlock(&nf_conntrack_locks[h2]);
121}
122
123
124static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
125 unsigned int h2, unsigned int sequence)
126{
127 h1 %= CONNTRACK_LOCKS;
128 h2 %= CONNTRACK_LOCKS;
129 if (h1 <= h2) {
130 nf_conntrack_lock(&nf_conntrack_locks[h1]);
131 if (h1 != h2)
132 spin_lock_nested(&nf_conntrack_locks[h2],
133 SINGLE_DEPTH_NESTING);
134 } else {
135 nf_conntrack_lock(&nf_conntrack_locks[h2]);
136 spin_lock_nested(&nf_conntrack_locks[h1],
137 SINGLE_DEPTH_NESTING);
138 }
139 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
140 nf_conntrack_double_unlock(h1, h2);
141 return true;
142 }
143 return false;
144}
145
146static void nf_conntrack_all_lock(void)
147{
148 int i;
149
150 spin_lock(&nf_conntrack_locks_all_lock);
151 nf_conntrack_locks_all = true;
152
153
154
155
156
157
158
159 smp_mb();
160
161 for (i = 0; i < CONNTRACK_LOCKS; i++) {
162 spin_unlock_wait(&nf_conntrack_locks[i]);
163 }
164}
165
166static void nf_conntrack_all_unlock(void)
167{
168
169
170
171
172
173
174 smp_store_release(&nf_conntrack_locks_all, false);
175 spin_unlock(&nf_conntrack_locks_all_lock);
176}
177
178unsigned int nf_conntrack_htable_size __read_mostly;
179EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
180
181unsigned int nf_conntrack_max __read_mostly;
182seqcount_t nf_conntrack_generation __read_mostly;
183
184
185
186
187
188DEFINE_PER_CPU_ALIGNED(struct nf_conn, nf_conntrack_untracked);
189EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
190
191static unsigned int nf_conntrack_hash_rnd __read_mostly;
192
193static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
194 const struct net *net)
195{
196 unsigned int n;
197 u32 seed;
198
199 get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
200
201
202
203
204
205 seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
206 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
207 return jhash2((u32 *)tuple, n, seed ^
208 (((__force __u16)tuple->dst.u.all << 16) |
209 tuple->dst.protonum));
210}
211
212static u32 scale_hash(u32 hash)
213{
214 return reciprocal_scale(hash, nf_conntrack_htable_size);
215}
216
217static u32 __hash_conntrack(const struct net *net,
218 const struct nf_conntrack_tuple *tuple,
219 unsigned int size)
220{
221 return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
222}
223
224static u32 hash_conntrack(const struct net *net,
225 const struct nf_conntrack_tuple *tuple)
226{
227 return scale_hash(hash_conntrack_raw(tuple, net));
228}
229
230bool
231nf_ct_get_tuple(const struct sk_buff *skb,
232 unsigned int nhoff,
233 unsigned int dataoff,
234 u_int16_t l3num,
235 u_int8_t protonum,
236 struct net *net,
237 struct nf_conntrack_tuple *tuple,
238 const struct nf_conntrack_l3proto *l3proto,
239 const struct nf_conntrack_l4proto *l4proto)
240{
241 memset(tuple, 0, sizeof(*tuple));
242
243 tuple->src.l3num = l3num;
244 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
245 return false;
246
247 tuple->dst.protonum = protonum;
248 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
249
250 return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
251}
252EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
253
254bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
255 u_int16_t l3num,
256 struct net *net, struct nf_conntrack_tuple *tuple)
257{
258 struct nf_conntrack_l3proto *l3proto;
259 struct nf_conntrack_l4proto *l4proto;
260 unsigned int protoff;
261 u_int8_t protonum;
262 int ret;
263
264 rcu_read_lock();
265
266 l3proto = __nf_ct_l3proto_find(l3num);
267 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
268 if (ret != NF_ACCEPT) {
269 rcu_read_unlock();
270 return false;
271 }
272
273 l4proto = __nf_ct_l4proto_find(l3num, protonum);
274
275 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
276 l3proto, l4proto);
277
278 rcu_read_unlock();
279 return ret;
280}
281EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
282
283bool
284nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
285 const struct nf_conntrack_tuple *orig,
286 const struct nf_conntrack_l3proto *l3proto,
287 const struct nf_conntrack_l4proto *l4proto)
288{
289 memset(inverse, 0, sizeof(*inverse));
290
291 inverse->src.l3num = orig->src.l3num;
292 if (l3proto->invert_tuple(inverse, orig) == 0)
293 return false;
294
295 inverse->dst.dir = !orig->dst.dir;
296
297 inverse->dst.protonum = orig->dst.protonum;
298 return l4proto->invert_tuple(inverse, orig);
299}
300EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
301
302static void
303clean_from_lists(struct nf_conn *ct)
304{
305 pr_debug("clean_from_lists(%p)\n", ct);
306 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
307 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
308
309
310 nf_ct_remove_expectations(ct);
311}
312
313
314static void nf_ct_add_to_dying_list(struct nf_conn *ct)
315{
316 struct ct_pcpu *pcpu;
317
318
319 ct->cpu = smp_processor_id();
320 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
321
322 spin_lock(&pcpu->lock);
323 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
324 &pcpu->dying);
325 spin_unlock(&pcpu->lock);
326}
327
328
329static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
330{
331 struct ct_pcpu *pcpu;
332
333
334 ct->cpu = smp_processor_id();
335 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
336
337 spin_lock(&pcpu->lock);
338 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
339 &pcpu->unconfirmed);
340 spin_unlock(&pcpu->lock);
341}
342
343
344static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
345{
346 struct ct_pcpu *pcpu;
347
348
349 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
350
351 spin_lock(&pcpu->lock);
352 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
353 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
354 spin_unlock(&pcpu->lock);
355}
356
357#define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
358
359
360struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
361 const struct nf_conntrack_zone *zone,
362 gfp_t flags)
363{
364 struct nf_conn *tmpl, *p;
365
366 if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) {
367 tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags);
368 if (!tmpl)
369 return NULL;
370
371 p = tmpl;
372 tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
373 if (tmpl != p) {
374 tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
375 tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p;
376 }
377 } else {
378 tmpl = kzalloc(sizeof(*tmpl), flags);
379 if (!tmpl)
380 return NULL;
381 }
382
383 tmpl->status = IPS_TEMPLATE;
384 write_pnet(&tmpl->ct_net, net);
385 nf_ct_zone_add(tmpl, zone);
386 atomic_set(&tmpl->ct_general.use, 0);
387
388 return tmpl;
389}
390EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
391
392void nf_ct_tmpl_free(struct nf_conn *tmpl)
393{
394 nf_ct_ext_destroy(tmpl);
395 nf_ct_ext_free(tmpl);
396
397 if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK)
398 kfree((char *)tmpl - tmpl->proto.tmpl_padto);
399 else
400 kfree(tmpl);
401}
402EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
403
404static void
405destroy_conntrack(struct nf_conntrack *nfct)
406{
407 struct nf_conn *ct = (struct nf_conn *)nfct;
408 struct nf_conntrack_l4proto *l4proto;
409
410 pr_debug("destroy_conntrack(%p)\n", ct);
411 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
412
413 if (unlikely(nf_ct_is_template(ct))) {
414 nf_ct_tmpl_free(ct);
415 return;
416 }
417 rcu_read_lock();
418 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
419 if (l4proto->destroy)
420 l4proto->destroy(ct);
421
422 rcu_read_unlock();
423
424 local_bh_disable();
425
426
427
428
429
430 nf_ct_remove_expectations(ct);
431
432 nf_ct_del_from_dying_or_unconfirmed_list(ct);
433
434 local_bh_enable();
435
436 if (ct->master)
437 nf_ct_put(ct->master);
438
439 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
440 nf_conntrack_free(ct);
441}
442
443static void nf_ct_delete_from_lists(struct nf_conn *ct)
444{
445 struct net *net = nf_ct_net(ct);
446 unsigned int hash, reply_hash;
447 unsigned int sequence;
448
449 nf_ct_helper_destroy(ct);
450
451 local_bh_disable();
452 do {
453 sequence = read_seqcount_begin(&nf_conntrack_generation);
454 hash = hash_conntrack(net,
455 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
456 reply_hash = hash_conntrack(net,
457 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
458 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
459
460 clean_from_lists(ct);
461 nf_conntrack_double_unlock(hash, reply_hash);
462
463 nf_ct_add_to_dying_list(ct);
464
465 local_bh_enable();
466}
467
468bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
469{
470 struct nf_conn_tstamp *tstamp;
471
472 if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
473 return false;
474
475 tstamp = nf_conn_tstamp_find(ct);
476 if (tstamp && tstamp->stop == 0)
477 tstamp->stop = ktime_get_real_ns();
478
479 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
480 portid, report) < 0) {
481
482
483
484 nf_ct_delete_from_lists(ct);
485 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
486 return false;
487 }
488
489 nf_conntrack_ecache_work(nf_ct_net(ct));
490 nf_ct_delete_from_lists(ct);
491 nf_ct_put(ct);
492 return true;
493}
494EXPORT_SYMBOL_GPL(nf_ct_delete);
495
496static inline bool
497nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
498 const struct nf_conntrack_tuple *tuple,
499 const struct nf_conntrack_zone *zone,
500 const struct net *net)
501{
502 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
503
504
505
506
507 return nf_ct_tuple_equal(tuple, &h->tuple) &&
508 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
509 nf_ct_is_confirmed(ct) &&
510 net_eq(net, nf_ct_net(ct));
511}
512
513
514static void nf_ct_gc_expired(struct nf_conn *ct)
515{
516 if (!atomic_inc_not_zero(&ct->ct_general.use))
517 return;
518
519 if (nf_ct_should_gc(ct))
520 nf_ct_kill(ct);
521
522 nf_ct_put(ct);
523}
524
525
526
527
528
529
530static struct nf_conntrack_tuple_hash *
531____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
532 const struct nf_conntrack_tuple *tuple, u32 hash)
533{
534 struct nf_conntrack_tuple_hash *h;
535 struct hlist_nulls_head *ct_hash;
536 struct hlist_nulls_node *n;
537 unsigned int bucket, hsize;
538
539begin:
540 nf_conntrack_get_ht(&ct_hash, &hsize);
541 bucket = reciprocal_scale(hash, hsize);
542
543 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
544 struct nf_conn *ct;
545
546 ct = nf_ct_tuplehash_to_ctrack(h);
547 if (nf_ct_is_expired(ct)) {
548 nf_ct_gc_expired(ct);
549 continue;
550 }
551
552 if (nf_ct_is_dying(ct))
553 continue;
554
555 if (nf_ct_key_equal(h, tuple, zone, net))
556 return h;
557 }
558
559
560
561
562
563 if (get_nulls_value(n) != bucket) {
564 NF_CT_STAT_INC_ATOMIC(net, search_restart);
565 goto begin;
566 }
567
568 return NULL;
569}
570
571
572static struct nf_conntrack_tuple_hash *
573__nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
574 const struct nf_conntrack_tuple *tuple, u32 hash)
575{
576 struct nf_conntrack_tuple_hash *h;
577 struct nf_conn *ct;
578
579 rcu_read_lock();
580begin:
581 h = ____nf_conntrack_find(net, zone, tuple, hash);
582 if (h) {
583 ct = nf_ct_tuplehash_to_ctrack(h);
584 if (unlikely(nf_ct_is_dying(ct) ||
585 !atomic_inc_not_zero(&ct->ct_general.use)))
586 h = NULL;
587 else {
588 if (unlikely(!nf_ct_key_equal(h, tuple, zone, net))) {
589 nf_ct_put(ct);
590 goto begin;
591 }
592 }
593 }
594 rcu_read_unlock();
595
596 return h;
597}
598
599struct nf_conntrack_tuple_hash *
600nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
601 const struct nf_conntrack_tuple *tuple)
602{
603 return __nf_conntrack_find_get(net, zone, tuple,
604 hash_conntrack_raw(tuple, net));
605}
606EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
607
608static void __nf_conntrack_hash_insert(struct nf_conn *ct,
609 unsigned int hash,
610 unsigned int reply_hash)
611{
612 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
613 &nf_conntrack_hash[hash]);
614 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
615 &nf_conntrack_hash[reply_hash]);
616}
617
618int
619nf_conntrack_hash_check_insert(struct nf_conn *ct)
620{
621 const struct nf_conntrack_zone *zone;
622 struct net *net = nf_ct_net(ct);
623 unsigned int hash, reply_hash;
624 struct nf_conntrack_tuple_hash *h;
625 struct hlist_nulls_node *n;
626 unsigned int sequence;
627
628 zone = nf_ct_zone(ct);
629
630 local_bh_disable();
631 do {
632 sequence = read_seqcount_begin(&nf_conntrack_generation);
633 hash = hash_conntrack(net,
634 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
635 reply_hash = hash_conntrack(net,
636 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
637 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
638
639
640 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
641 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
642 zone, net))
643 goto out;
644
645 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
646 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
647 zone, net))
648 goto out;
649
650 smp_wmb();
651
652 atomic_set(&ct->ct_general.use, 2);
653 __nf_conntrack_hash_insert(ct, hash, reply_hash);
654 nf_conntrack_double_unlock(hash, reply_hash);
655 NF_CT_STAT_INC(net, insert);
656 local_bh_enable();
657 return 0;
658
659out:
660 nf_conntrack_double_unlock(hash, reply_hash);
661 NF_CT_STAT_INC(net, insert_failed);
662 local_bh_enable();
663 return -EEXIST;
664}
665EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
666
667static inline void nf_ct_acct_update(struct nf_conn *ct,
668 enum ip_conntrack_info ctinfo,
669 unsigned int len)
670{
671 struct nf_conn_acct *acct;
672
673 acct = nf_conn_acct_find(ct);
674 if (acct) {
675 struct nf_conn_counter *counter = acct->counter;
676
677 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
678 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
679 }
680}
681
682static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
683 const struct nf_conn *loser_ct)
684{
685 struct nf_conn_acct *acct;
686
687 acct = nf_conn_acct_find(loser_ct);
688 if (acct) {
689 struct nf_conn_counter *counter = acct->counter;
690 unsigned int bytes;
691
692
693 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
694 nf_ct_acct_update(ct, ctinfo, bytes);
695 }
696}
697
698
699static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
700 enum ip_conntrack_info ctinfo,
701 struct nf_conntrack_tuple_hash *h)
702{
703
704 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
705 struct nf_conntrack_l4proto *l4proto;
706
707 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
708 if (l4proto->allow_clash &&
709 !nfct_nat(ct) &&
710 !nf_ct_is_dying(ct) &&
711 atomic_inc_not_zero(&ct->ct_general.use)) {
712 enum ip_conntrack_info oldinfo;
713 struct nf_conn *loser_ct = nf_ct_get(skb, &oldinfo);
714
715 nf_ct_acct_merge(ct, ctinfo, loser_ct);
716 nf_conntrack_put(&loser_ct->ct_general);
717 nf_ct_set(skb, ct, oldinfo);
718 return NF_ACCEPT;
719 }
720 NF_CT_STAT_INC(net, drop);
721 return NF_DROP;
722}
723
724
725int
726__nf_conntrack_confirm(struct sk_buff *skb)
727{
728 const struct nf_conntrack_zone *zone;
729 unsigned int hash, reply_hash;
730 struct nf_conntrack_tuple_hash *h;
731 struct nf_conn *ct;
732 struct nf_conn_help *help;
733 struct nf_conn_tstamp *tstamp;
734 struct hlist_nulls_node *n;
735 enum ip_conntrack_info ctinfo;
736 struct net *net;
737 unsigned int sequence;
738 int ret = NF_DROP;
739
740 ct = nf_ct_get(skb, &ctinfo);
741 net = nf_ct_net(ct);
742
743
744
745
746
747 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
748 return NF_ACCEPT;
749
750 zone = nf_ct_zone(ct);
751 local_bh_disable();
752
753 do {
754 sequence = read_seqcount_begin(&nf_conntrack_generation);
755
756 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
757 hash = scale_hash(hash);
758 reply_hash = hash_conntrack(net,
759 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
760
761 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
762
763
764
765
766
767
768
769
770
771
772 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
773 pr_debug("Confirming conntrack %p\n", ct);
774
775
776
777
778
779 nf_ct_del_from_dying_or_unconfirmed_list(ct);
780
781 if (unlikely(nf_ct_is_dying(ct))) {
782 nf_ct_add_to_dying_list(ct);
783 goto dying;
784 }
785
786
787
788
789 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
790 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
791 zone, net))
792 goto out;
793
794 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
795 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
796 zone, net))
797 goto out;
798
799
800
801
802 ct->timeout += nfct_time_stamp;
803 atomic_inc(&ct->ct_general.use);
804 ct->status |= IPS_CONFIRMED;
805
806
807 tstamp = nf_conn_tstamp_find(ct);
808 if (tstamp) {
809 if (skb->tstamp == 0)
810 __net_timestamp(skb);
811
812 tstamp->start = ktime_to_ns(skb->tstamp);
813 }
814
815
816
817
818
819 __nf_conntrack_hash_insert(ct, hash, reply_hash);
820 nf_conntrack_double_unlock(hash, reply_hash);
821 local_bh_enable();
822
823 help = nfct_help(ct);
824 if (help && help->helper)
825 nf_conntrack_event_cache(IPCT_HELPER, ct);
826
827 nf_conntrack_event_cache(master_ct(ct) ?
828 IPCT_RELATED : IPCT_NEW, ct);
829 return NF_ACCEPT;
830
831out:
832 nf_ct_add_to_dying_list(ct);
833 ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
834dying:
835 nf_conntrack_double_unlock(hash, reply_hash);
836 NF_CT_STAT_INC(net, insert_failed);
837 local_bh_enable();
838 return ret;
839}
840EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
841
842
843
844int
845nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
846 const struct nf_conn *ignored_conntrack)
847{
848 struct net *net = nf_ct_net(ignored_conntrack);
849 const struct nf_conntrack_zone *zone;
850 struct nf_conntrack_tuple_hash *h;
851 struct hlist_nulls_head *ct_hash;
852 unsigned int hash, hsize;
853 struct hlist_nulls_node *n;
854 struct nf_conn *ct;
855
856 zone = nf_ct_zone(ignored_conntrack);
857
858 rcu_read_lock();
859 begin:
860 nf_conntrack_get_ht(&ct_hash, &hsize);
861 hash = __hash_conntrack(net, tuple, hsize);
862
863 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
864 ct = nf_ct_tuplehash_to_ctrack(h);
865
866 if (ct == ignored_conntrack)
867 continue;
868
869 if (nf_ct_is_expired(ct)) {
870 nf_ct_gc_expired(ct);
871 continue;
872 }
873
874 if (nf_ct_key_equal(h, tuple, zone, net)) {
875 NF_CT_STAT_INC_ATOMIC(net, found);
876 rcu_read_unlock();
877 return 1;
878 }
879 }
880
881 if (get_nulls_value(n) != hash) {
882 NF_CT_STAT_INC_ATOMIC(net, search_restart);
883 goto begin;
884 }
885
886 rcu_read_unlock();
887
888 return 0;
889}
890EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
891
892#define NF_CT_EVICTION_RANGE 8
893
894
895
896static unsigned int early_drop_list(struct net *net,
897 struct hlist_nulls_head *head)
898{
899 struct nf_conntrack_tuple_hash *h;
900 struct hlist_nulls_node *n;
901 unsigned int drops = 0;
902 struct nf_conn *tmp;
903
904 hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
905 tmp = nf_ct_tuplehash_to_ctrack(h);
906
907 if (nf_ct_is_expired(tmp)) {
908 nf_ct_gc_expired(tmp);
909 continue;
910 }
911
912 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
913 !net_eq(nf_ct_net(tmp), net) ||
914 nf_ct_is_dying(tmp))
915 continue;
916
917 if (!atomic_inc_not_zero(&tmp->ct_general.use))
918 continue;
919
920
921
922
923
924
925
926
927 if (net_eq(nf_ct_net(tmp), net) &&
928 nf_ct_is_confirmed(tmp) &&
929 nf_ct_delete(tmp, 0, 0))
930 drops++;
931
932 nf_ct_put(tmp);
933 }
934
935 return drops;
936}
937
938static noinline int early_drop(struct net *net, unsigned int _hash)
939{
940 unsigned int i;
941
942 for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
943 struct hlist_nulls_head *ct_hash;
944 unsigned int hash, hsize, drops;
945
946 rcu_read_lock();
947 nf_conntrack_get_ht(&ct_hash, &hsize);
948 hash = reciprocal_scale(_hash++, hsize);
949
950 drops = early_drop_list(net, &ct_hash[hash]);
951 rcu_read_unlock();
952
953 if (drops) {
954 NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
955 return true;
956 }
957 }
958
959 return false;
960}
961
962static void gc_worker(struct work_struct *work)
963{
964 unsigned int min_interval = max(HZ / GC_MAX_BUCKETS_DIV, 1u);
965 unsigned int i, goal, buckets = 0, expired_count = 0;
966 struct conntrack_gc_work *gc_work;
967 unsigned int ratio, scanned = 0;
968 unsigned long next_run;
969
970 gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
971
972 goal = nf_conntrack_htable_size / GC_MAX_BUCKETS_DIV;
973 i = gc_work->last_bucket;
974
975 do {
976 struct nf_conntrack_tuple_hash *h;
977 struct hlist_nulls_head *ct_hash;
978 struct hlist_nulls_node *n;
979 unsigned int hashsz;
980 struct nf_conn *tmp;
981
982 i++;
983 rcu_read_lock();
984
985 nf_conntrack_get_ht(&ct_hash, &hashsz);
986 if (i >= hashsz)
987 i = 0;
988
989 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
990 tmp = nf_ct_tuplehash_to_ctrack(h);
991
992 scanned++;
993 if (nf_ct_is_expired(tmp)) {
994 nf_ct_gc_expired(tmp);
995 expired_count++;
996 continue;
997 }
998 }
999
1000
1001
1002
1003
1004 rcu_read_unlock();
1005 cond_resched_rcu_qs();
1006 } while (++buckets < goal);
1007
1008 if (gc_work->exiting)
1009 return;
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028 ratio = scanned ? expired_count * 100 / scanned : 0;
1029 if (ratio > GC_EVICT_RATIO) {
1030 gc_work->next_gc_run = min_interval;
1031 } else {
1032 unsigned int max = GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV;
1033
1034 BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV) == 0);
1035
1036 gc_work->next_gc_run += min_interval;
1037 if (gc_work->next_gc_run > max)
1038 gc_work->next_gc_run = max;
1039 }
1040
1041 next_run = gc_work->next_gc_run;
1042 gc_work->last_bucket = i;
1043 queue_delayed_work(system_long_wq, &gc_work->dwork, next_run);
1044}
1045
1046static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
1047{
1048 INIT_DELAYED_WORK(&gc_work->dwork, gc_worker);
1049 gc_work->next_gc_run = HZ;
1050 gc_work->exiting = false;
1051}
1052
1053static struct nf_conn *
1054__nf_conntrack_alloc(struct net *net,
1055 const struct nf_conntrack_zone *zone,
1056 const struct nf_conntrack_tuple *orig,
1057 const struct nf_conntrack_tuple *repl,
1058 gfp_t gfp, u32 hash)
1059{
1060 struct nf_conn *ct;
1061
1062
1063 atomic_inc(&net->ct.count);
1064
1065 if (nf_conntrack_max &&
1066 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
1067 if (!early_drop(net, hash)) {
1068 atomic_dec(&net->ct.count);
1069 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
1070 return ERR_PTR(-ENOMEM);
1071 }
1072 }
1073
1074
1075
1076
1077
1078 ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
1079 if (ct == NULL)
1080 goto out;
1081
1082 spin_lock_init(&ct->lock);
1083 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
1084 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
1085 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
1086
1087 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
1088 ct->status = 0;
1089 write_pnet(&ct->ct_net, net);
1090 memset(&ct->__nfct_init_offset[0], 0,
1091 offsetof(struct nf_conn, proto) -
1092 offsetof(struct nf_conn, __nfct_init_offset[0]));
1093
1094 nf_ct_zone_add(ct, zone);
1095
1096
1097
1098
1099 atomic_set(&ct->ct_general.use, 0);
1100 return ct;
1101out:
1102 atomic_dec(&net->ct.count);
1103 return ERR_PTR(-ENOMEM);
1104}
1105
1106struct nf_conn *nf_conntrack_alloc(struct net *net,
1107 const struct nf_conntrack_zone *zone,
1108 const struct nf_conntrack_tuple *orig,
1109 const struct nf_conntrack_tuple *repl,
1110 gfp_t gfp)
1111{
1112 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
1113}
1114EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
1115
1116void nf_conntrack_free(struct nf_conn *ct)
1117{
1118 struct net *net = nf_ct_net(ct);
1119
1120
1121
1122
1123 NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
1124
1125 nf_ct_ext_destroy(ct);
1126 nf_ct_ext_free(ct);
1127 kmem_cache_free(nf_conntrack_cachep, ct);
1128 smp_mb__before_atomic();
1129 atomic_dec(&net->ct.count);
1130}
1131EXPORT_SYMBOL_GPL(nf_conntrack_free);
1132
1133
1134
1135
1136static struct nf_conntrack_tuple_hash *
1137init_conntrack(struct net *net, struct nf_conn *tmpl,
1138 const struct nf_conntrack_tuple *tuple,
1139 struct nf_conntrack_l3proto *l3proto,
1140 struct nf_conntrack_l4proto *l4proto,
1141 struct sk_buff *skb,
1142 unsigned int dataoff, u32 hash)
1143{
1144 struct nf_conn *ct;
1145 struct nf_conn_help *help;
1146 struct nf_conntrack_tuple repl_tuple;
1147 struct nf_conntrack_ecache *ecache;
1148 struct nf_conntrack_expect *exp = NULL;
1149 const struct nf_conntrack_zone *zone;
1150 struct nf_conn_timeout *timeout_ext;
1151 struct nf_conntrack_zone tmp;
1152 unsigned int *timeouts;
1153
1154 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
1155 pr_debug("Can't invert tuple.\n");
1156 return NULL;
1157 }
1158
1159 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1160 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1161 hash);
1162 if (IS_ERR(ct))
1163 return (struct nf_conntrack_tuple_hash *)ct;
1164
1165 if (!nf_ct_add_synproxy(ct, tmpl)) {
1166 nf_conntrack_free(ct);
1167 return ERR_PTR(-ENOMEM);
1168 }
1169
1170 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1171 if (timeout_ext) {
1172 timeouts = nf_ct_timeout_data(timeout_ext);
1173 if (unlikely(!timeouts))
1174 timeouts = l4proto->get_timeouts(net);
1175 } else {
1176 timeouts = l4proto->get_timeouts(net);
1177 }
1178
1179 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
1180 nf_conntrack_free(ct);
1181 pr_debug("can't track with proto module\n");
1182 return NULL;
1183 }
1184
1185 if (timeout_ext)
1186 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1187 GFP_ATOMIC);
1188
1189 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1190 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1191 nf_ct_labels_ext_add(ct);
1192
1193 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1194 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1195 ecache ? ecache->expmask : 0,
1196 GFP_ATOMIC);
1197
1198 local_bh_disable();
1199 if (net->ct.expect_count) {
1200 spin_lock(&nf_conntrack_expect_lock);
1201 exp = nf_ct_find_expectation(net, zone, tuple);
1202 if (exp) {
1203 pr_debug("expectation arrives ct=%p exp=%p\n",
1204 ct, exp);
1205
1206 __set_bit(IPS_EXPECTED_BIT, &ct->status);
1207
1208 ct->master = exp->master;
1209 if (exp->helper) {
1210 help = nf_ct_helper_ext_add(ct, exp->helper,
1211 GFP_ATOMIC);
1212 if (help)
1213 rcu_assign_pointer(help->helper, exp->helper);
1214 }
1215
1216#ifdef CONFIG_NF_CONNTRACK_MARK
1217 ct->mark = exp->master->mark;
1218#endif
1219#ifdef CONFIG_NF_CONNTRACK_SECMARK
1220 ct->secmark = exp->master->secmark;
1221#endif
1222 NF_CT_STAT_INC(net, expect_new);
1223 }
1224 spin_unlock(&nf_conntrack_expect_lock);
1225 }
1226 if (!exp)
1227 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1228
1229
1230 nf_conntrack_get(&ct->ct_general);
1231 nf_ct_add_to_unconfirmed_list(ct);
1232
1233 local_bh_enable();
1234
1235 if (exp) {
1236 if (exp->expectfn)
1237 exp->expectfn(ct, exp);
1238 nf_ct_expect_put(exp);
1239 }
1240
1241 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1242}
1243
1244
1245static inline struct nf_conn *
1246resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1247 struct sk_buff *skb,
1248 unsigned int dataoff,
1249 u_int16_t l3num,
1250 u_int8_t protonum,
1251 struct nf_conntrack_l3proto *l3proto,
1252 struct nf_conntrack_l4proto *l4proto,
1253 int *set_reply,
1254 enum ip_conntrack_info *ctinfo)
1255{
1256 const struct nf_conntrack_zone *zone;
1257 struct nf_conntrack_tuple tuple;
1258 struct nf_conntrack_tuple_hash *h;
1259 struct nf_conntrack_zone tmp;
1260 struct nf_conn *ct;
1261 u32 hash;
1262
1263 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1264 dataoff, l3num, protonum, net, &tuple, l3proto,
1265 l4proto)) {
1266 pr_debug("Can't get tuple\n");
1267 return NULL;
1268 }
1269
1270
1271 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1272 hash = hash_conntrack_raw(&tuple, net);
1273 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1274 if (!h) {
1275 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1276 skb, dataoff, hash);
1277 if (!h)
1278 return NULL;
1279 if (IS_ERR(h))
1280 return (void *)h;
1281 }
1282 ct = nf_ct_tuplehash_to_ctrack(h);
1283
1284
1285 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1286 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1287
1288 *set_reply = 1;
1289 } else {
1290
1291 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1292 pr_debug("normal packet for %p\n", ct);
1293 *ctinfo = IP_CT_ESTABLISHED;
1294 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1295 pr_debug("related packet for %p\n", ct);
1296 *ctinfo = IP_CT_RELATED;
1297 } else {
1298 pr_debug("new packet for %p\n", ct);
1299 *ctinfo = IP_CT_NEW;
1300 }
1301 *set_reply = 0;
1302 }
1303 nf_ct_set(skb, ct, *ctinfo);
1304 return ct;
1305}
1306
1307unsigned int
1308nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1309 struct sk_buff *skb)
1310{
1311 struct nf_conn *ct, *tmpl;
1312 enum ip_conntrack_info ctinfo;
1313 struct nf_conntrack_l3proto *l3proto;
1314 struct nf_conntrack_l4proto *l4proto;
1315 unsigned int *timeouts;
1316 unsigned int dataoff;
1317 u_int8_t protonum;
1318 int set_reply = 0;
1319 int ret;
1320
1321 tmpl = nf_ct_get(skb, &ctinfo);
1322 if (tmpl) {
1323
1324 if (!nf_ct_is_template(tmpl)) {
1325 NF_CT_STAT_INC_ATOMIC(net, ignore);
1326 return NF_ACCEPT;
1327 }
1328 skb->_nfct = 0;
1329 }
1330
1331
1332 l3proto = __nf_ct_l3proto_find(pf);
1333 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1334 &dataoff, &protonum);
1335 if (ret <= 0) {
1336 pr_debug("not prepared to track yet or error occurred\n");
1337 NF_CT_STAT_INC_ATOMIC(net, error);
1338 NF_CT_STAT_INC_ATOMIC(net, invalid);
1339 ret = -ret;
1340 goto out;
1341 }
1342
1343 l4proto = __nf_ct_l4proto_find(pf, protonum);
1344
1345
1346
1347
1348 if (l4proto->error != NULL) {
1349 ret = l4proto->error(net, tmpl, skb, dataoff, pf, hooknum);
1350 if (ret <= 0) {
1351 NF_CT_STAT_INC_ATOMIC(net, error);
1352 NF_CT_STAT_INC_ATOMIC(net, invalid);
1353 ret = -ret;
1354 goto out;
1355 }
1356
1357 if (skb->_nfct)
1358 goto out;
1359 }
1360repeat:
1361 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1362 l3proto, l4proto, &set_reply, &ctinfo);
1363 if (!ct) {
1364
1365 NF_CT_STAT_INC_ATOMIC(net, invalid);
1366 ret = NF_ACCEPT;
1367 goto out;
1368 }
1369
1370 if (IS_ERR(ct)) {
1371
1372 NF_CT_STAT_INC_ATOMIC(net, drop);
1373 ret = NF_DROP;
1374 goto out;
1375 }
1376
1377 NF_CT_ASSERT(skb_nfct(skb));
1378
1379
1380 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1381
1382 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1383 if (ret <= 0) {
1384
1385
1386 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1387 nf_conntrack_put(&ct->ct_general);
1388 skb->_nfct = 0;
1389 NF_CT_STAT_INC_ATOMIC(net, invalid);
1390 if (ret == -NF_DROP)
1391 NF_CT_STAT_INC_ATOMIC(net, drop);
1392
1393
1394
1395
1396 if (ret == -NF_REPEAT)
1397 goto repeat;
1398 ret = -ret;
1399 goto out;
1400 }
1401
1402 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1403 nf_conntrack_event_cache(IPCT_REPLY, ct);
1404out:
1405 if (tmpl)
1406 nf_ct_put(tmpl);
1407
1408 return ret;
1409}
1410EXPORT_SYMBOL_GPL(nf_conntrack_in);
1411
1412bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1413 const struct nf_conntrack_tuple *orig)
1414{
1415 bool ret;
1416
1417 rcu_read_lock();
1418 ret = nf_ct_invert_tuple(inverse, orig,
1419 __nf_ct_l3proto_find(orig->src.l3num),
1420 __nf_ct_l4proto_find(orig->src.l3num,
1421 orig->dst.protonum));
1422 rcu_read_unlock();
1423 return ret;
1424}
1425EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1426
1427
1428
1429void nf_conntrack_alter_reply(struct nf_conn *ct,
1430 const struct nf_conntrack_tuple *newreply)
1431{
1432 struct nf_conn_help *help = nfct_help(ct);
1433
1434
1435 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1436
1437 pr_debug("Altering reply tuple of %p to ", ct);
1438 nf_ct_dump_tuple(newreply);
1439
1440 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1441 if (ct->master || (help && !hlist_empty(&help->expectations)))
1442 return;
1443
1444 rcu_read_lock();
1445 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1446 rcu_read_unlock();
1447}
1448EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1449
1450
1451void __nf_ct_refresh_acct(struct nf_conn *ct,
1452 enum ip_conntrack_info ctinfo,
1453 const struct sk_buff *skb,
1454 unsigned long extra_jiffies,
1455 int do_acct)
1456{
1457 NF_CT_ASSERT(skb);
1458
1459
1460 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1461 goto acct;
1462
1463
1464 if (nf_ct_is_confirmed(ct))
1465 extra_jiffies += nfct_time_stamp;
1466
1467 ct->timeout = extra_jiffies;
1468acct:
1469 if (do_acct)
1470 nf_ct_acct_update(ct, ctinfo, skb->len);
1471}
1472EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1473
1474bool nf_ct_kill_acct(struct nf_conn *ct,
1475 enum ip_conntrack_info ctinfo,
1476 const struct sk_buff *skb)
1477{
1478 nf_ct_acct_update(ct, ctinfo, skb->len);
1479
1480 return nf_ct_delete(ct, 0, 0);
1481}
1482EXPORT_SYMBOL_GPL(nf_ct_kill_acct);
1483
1484#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1485
1486#include <linux/netfilter/nfnetlink.h>
1487#include <linux/netfilter/nfnetlink_conntrack.h>
1488#include <linux/mutex.h>
1489
1490
1491
1492
1493int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1494 const struct nf_conntrack_tuple *tuple)
1495{
1496 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1497 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1498 goto nla_put_failure;
1499 return 0;
1500
1501nla_put_failure:
1502 return -1;
1503}
1504EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1505
1506const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1507 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1508 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1509};
1510EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1511
1512int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1513 struct nf_conntrack_tuple *t)
1514{
1515 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1516 return -EINVAL;
1517
1518 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1519 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1520
1521 return 0;
1522}
1523EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1524
1525int nf_ct_port_nlattr_tuple_size(void)
1526{
1527 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1528}
1529EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1530#endif
1531
1532
1533static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1534{
1535 struct nf_conn *ct;
1536 enum ip_conntrack_info ctinfo;
1537
1538
1539 ct = nf_ct_get(skb, &ctinfo);
1540 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1541 ctinfo = IP_CT_RELATED_REPLY;
1542 else
1543 ctinfo = IP_CT_RELATED;
1544
1545
1546 nf_ct_set(nskb, ct, ctinfo);
1547 nf_conntrack_get(skb_nfct(nskb));
1548}
1549
1550
1551static struct nf_conn *
1552get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1553 void *data, unsigned int *bucket)
1554{
1555 struct nf_conntrack_tuple_hash *h;
1556 struct nf_conn *ct;
1557 struct hlist_nulls_node *n;
1558 int cpu;
1559 spinlock_t *lockp;
1560
1561 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1562 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1563 local_bh_disable();
1564 nf_conntrack_lock(lockp);
1565 if (*bucket < nf_conntrack_htable_size) {
1566 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
1567 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1568 continue;
1569 ct = nf_ct_tuplehash_to_ctrack(h);
1570 if (net_eq(nf_ct_net(ct), net) &&
1571 iter(ct, data))
1572 goto found;
1573 }
1574 }
1575 spin_unlock(lockp);
1576 local_bh_enable();
1577 cond_resched();
1578 }
1579
1580 for_each_possible_cpu(cpu) {
1581 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1582
1583 spin_lock_bh(&pcpu->lock);
1584 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1585 ct = nf_ct_tuplehash_to_ctrack(h);
1586 if (iter(ct, data))
1587 set_bit(IPS_DYING_BIT, &ct->status);
1588 }
1589 spin_unlock_bh(&pcpu->lock);
1590 cond_resched();
1591 }
1592 return NULL;
1593found:
1594 atomic_inc(&ct->ct_general.use);
1595 spin_unlock(lockp);
1596 local_bh_enable();
1597 return ct;
1598}
1599
1600void nf_ct_iterate_cleanup(struct net *net,
1601 int (*iter)(struct nf_conn *i, void *data),
1602 void *data, u32 portid, int report)
1603{
1604 struct nf_conn *ct;
1605 unsigned int bucket = 0;
1606
1607 might_sleep();
1608
1609 if (atomic_read(&net->ct.count) == 0)
1610 return;
1611
1612 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1613
1614
1615 nf_ct_delete(ct, portid, report);
1616 nf_ct_put(ct);
1617 cond_resched();
1618 }
1619}
1620EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1621
1622static int kill_all(struct nf_conn *i, void *data)
1623{
1624 return 1;
1625}
1626
1627void nf_ct_free_hashtable(void *hash, unsigned int size)
1628{
1629 if (is_vmalloc_addr(hash))
1630 vfree(hash);
1631 else
1632 free_pages((unsigned long)hash,
1633 get_order(sizeof(struct hlist_head) * size));
1634}
1635EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1636
1637static int untrack_refs(void)
1638{
1639 int cnt = 0, cpu;
1640
1641 for_each_possible_cpu(cpu) {
1642 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1643
1644 cnt += atomic_read(&ct->ct_general.use) - 1;
1645 }
1646 return cnt;
1647}
1648
1649void nf_conntrack_cleanup_start(void)
1650{
1651 conntrack_gc_work.exiting = true;
1652 RCU_INIT_POINTER(ip_ct_attach, NULL);
1653}
1654
1655void nf_conntrack_cleanup_end(void)
1656{
1657 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1658 while (untrack_refs() > 0)
1659 schedule();
1660
1661 cancel_delayed_work_sync(&conntrack_gc_work.dwork);
1662 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1663
1664 nf_conntrack_proto_fini();
1665 nf_conntrack_seqadj_fini();
1666 nf_conntrack_labels_fini();
1667 nf_conntrack_helper_fini();
1668 nf_conntrack_timeout_fini();
1669 nf_conntrack_ecache_fini();
1670 nf_conntrack_tstamp_fini();
1671 nf_conntrack_acct_fini();
1672 nf_conntrack_expect_fini();
1673
1674 kmem_cache_destroy(nf_conntrack_cachep);
1675}
1676
1677
1678
1679
1680
1681void nf_conntrack_cleanup_net(struct net *net)
1682{
1683 LIST_HEAD(single);
1684
1685 list_add(&net->exit_list, &single);
1686 nf_conntrack_cleanup_net_list(&single);
1687}
1688
1689void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1690{
1691 int busy;
1692 struct net *net;
1693
1694
1695
1696
1697
1698
1699 synchronize_net();
1700i_see_dead_people:
1701 busy = 0;
1702 list_for_each_entry(net, net_exit_list, exit_list) {
1703 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1704 if (atomic_read(&net->ct.count) != 0)
1705 busy = 1;
1706 }
1707 if (busy) {
1708 schedule();
1709 goto i_see_dead_people;
1710 }
1711
1712 list_for_each_entry(net, net_exit_list, exit_list) {
1713 nf_conntrack_proto_pernet_fini(net);
1714 nf_conntrack_helper_pernet_fini(net);
1715 nf_conntrack_ecache_pernet_fini(net);
1716 nf_conntrack_tstamp_pernet_fini(net);
1717 nf_conntrack_acct_pernet_fini(net);
1718 nf_conntrack_expect_pernet_fini(net);
1719 free_percpu(net->ct.stat);
1720 free_percpu(net->ct.pcpu_lists);
1721 }
1722}
1723
1724void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1725{
1726 struct hlist_nulls_head *hash;
1727 unsigned int nr_slots, i;
1728 size_t sz;
1729
1730 if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1731 return NULL;
1732
1733 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1734 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1735
1736 if (nr_slots > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1737 return NULL;
1738
1739 sz = nr_slots * sizeof(struct hlist_nulls_head);
1740 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1741 get_order(sz));
1742 if (!hash)
1743 hash = vzalloc(sz);
1744
1745 if (hash && nulls)
1746 for (i = 0; i < nr_slots; i++)
1747 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1748
1749 return hash;
1750}
1751EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1752
1753int nf_conntrack_hash_resize(unsigned int hashsize)
1754{
1755 int i, bucket;
1756 unsigned int old_size;
1757 struct hlist_nulls_head *hash, *old_hash;
1758 struct nf_conntrack_tuple_hash *h;
1759 struct nf_conn *ct;
1760
1761 if (!hashsize)
1762 return -EINVAL;
1763
1764 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1765 if (!hash)
1766 return -ENOMEM;
1767
1768 old_size = nf_conntrack_htable_size;
1769 if (old_size == hashsize) {
1770 nf_ct_free_hashtable(hash, hashsize);
1771 return 0;
1772 }
1773
1774 local_bh_disable();
1775 nf_conntrack_all_lock();
1776 write_seqcount_begin(&nf_conntrack_generation);
1777
1778
1779
1780
1781
1782
1783
1784 for (i = 0; i < nf_conntrack_htable_size; i++) {
1785 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
1786 h = hlist_nulls_entry(nf_conntrack_hash[i].first,
1787 struct nf_conntrack_tuple_hash, hnnode);
1788 ct = nf_ct_tuplehash_to_ctrack(h);
1789 hlist_nulls_del_rcu(&h->hnnode);
1790 bucket = __hash_conntrack(nf_ct_net(ct),
1791 &h->tuple, hashsize);
1792 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1793 }
1794 }
1795 old_size = nf_conntrack_htable_size;
1796 old_hash = nf_conntrack_hash;
1797
1798 nf_conntrack_hash = hash;
1799 nf_conntrack_htable_size = hashsize;
1800
1801 write_seqcount_end(&nf_conntrack_generation);
1802 nf_conntrack_all_unlock();
1803 local_bh_enable();
1804
1805 synchronize_net();
1806 nf_ct_free_hashtable(old_hash, old_size);
1807 return 0;
1808}
1809
1810int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1811{
1812 unsigned int hashsize;
1813 int rc;
1814
1815 if (current->nsproxy->net_ns != &init_net)
1816 return -EOPNOTSUPP;
1817
1818
1819 if (!nf_conntrack_htable_size)
1820 return param_set_uint(val, kp);
1821
1822 rc = kstrtouint(val, 0, &hashsize);
1823 if (rc)
1824 return rc;
1825
1826 return nf_conntrack_hash_resize(hashsize);
1827}
1828EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1829
1830module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1831 &nf_conntrack_htable_size, 0600);
1832
1833void nf_ct_untracked_status_or(unsigned long bits)
1834{
1835 int cpu;
1836
1837 for_each_possible_cpu(cpu)
1838 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1839}
1840EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1841
1842int nf_conntrack_init_start(void)
1843{
1844 int max_factor = 8;
1845 int ret = -ENOMEM;
1846 int i, cpu;
1847
1848 seqcount_init(&nf_conntrack_generation);
1849
1850 for (i = 0; i < CONNTRACK_LOCKS; i++)
1851 spin_lock_init(&nf_conntrack_locks[i]);
1852
1853 if (!nf_conntrack_htable_size) {
1854
1855
1856
1857
1858
1859 nf_conntrack_htable_size
1860 = (((totalram_pages << PAGE_SHIFT) / 16384)
1861 / sizeof(struct hlist_head));
1862 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1863 nf_conntrack_htable_size = 65536;
1864 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1865 nf_conntrack_htable_size = 16384;
1866 if (nf_conntrack_htable_size < 32)
1867 nf_conntrack_htable_size = 32;
1868
1869
1870
1871
1872
1873 max_factor = 4;
1874 }
1875
1876 nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
1877 if (!nf_conntrack_hash)
1878 return -ENOMEM;
1879
1880 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1881
1882 nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1883 sizeof(struct nf_conn),
1884 NFCT_INFOMASK + 1,
1885 SLAB_DESTROY_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
1886 if (!nf_conntrack_cachep)
1887 goto err_cachep;
1888
1889 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1890 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1891 nf_conntrack_max);
1892
1893 ret = nf_conntrack_expect_init();
1894 if (ret < 0)
1895 goto err_expect;
1896
1897 ret = nf_conntrack_acct_init();
1898 if (ret < 0)
1899 goto err_acct;
1900
1901 ret = nf_conntrack_tstamp_init();
1902 if (ret < 0)
1903 goto err_tstamp;
1904
1905 ret = nf_conntrack_ecache_init();
1906 if (ret < 0)
1907 goto err_ecache;
1908
1909 ret = nf_conntrack_timeout_init();
1910 if (ret < 0)
1911 goto err_timeout;
1912
1913 ret = nf_conntrack_helper_init();
1914 if (ret < 0)
1915 goto err_helper;
1916
1917 ret = nf_conntrack_labels_init();
1918 if (ret < 0)
1919 goto err_labels;
1920
1921 ret = nf_conntrack_seqadj_init();
1922 if (ret < 0)
1923 goto err_seqadj;
1924
1925 ret = nf_conntrack_proto_init();
1926 if (ret < 0)
1927 goto err_proto;
1928
1929
1930 for_each_possible_cpu(cpu) {
1931 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1932 write_pnet(&ct->ct_net, &init_net);
1933 atomic_set(&ct->ct_general.use, 1);
1934 }
1935
1936 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1937
1938 conntrack_gc_work_init(&conntrack_gc_work);
1939 queue_delayed_work(system_long_wq, &conntrack_gc_work.dwork, HZ);
1940
1941 return 0;
1942
1943err_proto:
1944 nf_conntrack_seqadj_fini();
1945err_seqadj:
1946 nf_conntrack_labels_fini();
1947err_labels:
1948 nf_conntrack_helper_fini();
1949err_helper:
1950 nf_conntrack_timeout_fini();
1951err_timeout:
1952 nf_conntrack_ecache_fini();
1953err_ecache:
1954 nf_conntrack_tstamp_fini();
1955err_tstamp:
1956 nf_conntrack_acct_fini();
1957err_acct:
1958 nf_conntrack_expect_fini();
1959err_expect:
1960 kmem_cache_destroy(nf_conntrack_cachep);
1961err_cachep:
1962 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1963 return ret;
1964}
1965
1966void nf_conntrack_init_end(void)
1967{
1968
1969 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1970 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1971}
1972
1973
1974
1975
1976#define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1977#define DYING_NULLS_VAL ((1<<30)+1)
1978#define TEMPLATE_NULLS_VAL ((1<<30)+2)
1979
1980int nf_conntrack_init_net(struct net *net)
1981{
1982 int ret = -ENOMEM;
1983 int cpu;
1984
1985 atomic_set(&net->ct.count, 0);
1986
1987 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1988 if (!net->ct.pcpu_lists)
1989 goto err_stat;
1990
1991 for_each_possible_cpu(cpu) {
1992 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1993
1994 spin_lock_init(&pcpu->lock);
1995 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1996 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1997 }
1998
1999 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
2000 if (!net->ct.stat)
2001 goto err_pcpu_lists;
2002
2003 ret = nf_conntrack_expect_pernet_init(net);
2004 if (ret < 0)
2005 goto err_expect;
2006 ret = nf_conntrack_acct_pernet_init(net);
2007 if (ret < 0)
2008 goto err_acct;
2009 ret = nf_conntrack_tstamp_pernet_init(net);
2010 if (ret < 0)
2011 goto err_tstamp;
2012 ret = nf_conntrack_ecache_pernet_init(net);
2013 if (ret < 0)
2014 goto err_ecache;
2015 ret = nf_conntrack_helper_pernet_init(net);
2016 if (ret < 0)
2017 goto err_helper;
2018 ret = nf_conntrack_proto_pernet_init(net);
2019 if (ret < 0)
2020 goto err_proto;
2021 return 0;
2022
2023err_proto:
2024 nf_conntrack_helper_pernet_fini(net);
2025err_helper:
2026 nf_conntrack_ecache_pernet_fini(net);
2027err_ecache:
2028 nf_conntrack_tstamp_pernet_fini(net);
2029err_tstamp:
2030 nf_conntrack_acct_pernet_fini(net);
2031err_acct:
2032 nf_conntrack_expect_pernet_fini(net);
2033err_expect:
2034 free_percpu(net->ct.stat);
2035err_pcpu_lists:
2036 free_percpu(net->ct.pcpu_lists);
2037err_stat:
2038 return ret;
2039}
2040