1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Connection state tracking for netfilter. This is separated from,
3 but required by, the NAT layer; it can also be used by an iptables
4 extension. */
5
6 /* (C) 1999-2001 Paul `Rusty' Russell
7 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
8 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
9 * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/skbuff.h>
19 #include <linux/proc_fs.h>
20 #include <linux/vmalloc.h>
21 #include <linux/stddef.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/jhash.h>
25 #include <linux/siphash.h>
26 #include <linux/err.h>
27 #include <linux/percpu.h>
28 #include <linux/moduleparam.h>
29 #include <linux/notifier.h>
30 #include <linux/kernel.h>
31 #include <linux/netdevice.h>
32 #include <linux/socket.h>
33 #include <linux/mm.h>
34 #include <linux/nsproxy.h>
35 #include <linux/rculist_nulls.h>
36
37 #include <net/netfilter/nf_conntrack.h>
38 #include <net/netfilter/nf_conntrack_l4proto.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_seqadj.h>
42 #include <net/netfilter/nf_conntrack_core.h>
43 #include <net/netfilter/nf_conntrack_extend.h>
44 #include <net/netfilter/nf_conntrack_acct.h>
45 #include <net/netfilter/nf_conntrack_ecache.h>
46 #include <net/netfilter/nf_conntrack_zones.h>
47 #include <net/netfilter/nf_conntrack_timestamp.h>
48 #include <net/netfilter/nf_conntrack_timeout.h>
49 #include <net/netfilter/nf_conntrack_labels.h>
50 #include <net/netfilter/nf_conntrack_synproxy.h>
51 #include <net/netfilter/nf_nat.h>
52 #include <net/netfilter/nf_nat_helper.h>
53 #include <net/netns/hash.h>
54 #include <net/ip.h>
55
56 #include "nf_internals.h"
57
58 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
59 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
60
61 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
62 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
63
64 struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
65 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
66
67 struct conntrack_gc_work {
68 struct delayed_work dwork;
69 u32 last_bucket;
70 bool exiting;
71 bool early_drop;
72 long next_gc_run;
73 };
74
75 static __read_mostly struct kmem_cache *nf_conntrack_cachep;
76 static DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
77 static __read_mostly bool nf_conntrack_locks_all;
78
79 /* every gc cycle scans at most 1/GC_MAX_BUCKETS_DIV part of table */
80 #define GC_MAX_BUCKETS_DIV 128u
81 /* upper bound of full table scan */
82 #define GC_MAX_SCAN_JIFFIES (16u * HZ)
83 /* desired ratio of entries found to be expired */
84 #define GC_EVICT_RATIO 50u
85
86 static struct conntrack_gc_work conntrack_gc_work;
87
88 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
89 {
90 /* 1) Acquire the lock */
91 spin_lock(lock);
92
93 /* 2) read nf_conntrack_locks_all, with ACQUIRE semantics
94 * It pairs with the smp_store_release() in nf_conntrack_all_unlock()
95 */
96 if (likely(smp_load_acquire(&nf_conntrack_locks_all) == false))
97 return;
98
99 /* fast path failed, unlock */
100 spin_unlock(lock);
101
102 /* Slow path 1) get global lock */
103 spin_lock(&nf_conntrack_locks_all_lock);
104
105 /* Slow path 2) get the lock we want */
106 spin_lock(lock);
107
108 /* Slow path 3) release the global lock */
109 spin_unlock(&nf_conntrack_locks_all_lock);
110 }
111 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
112
113 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
114 {
115 h1 %= CONNTRACK_LOCKS;
116 h2 %= CONNTRACK_LOCKS;
117 spin_unlock(&nf_conntrack_locks[h1]);
118 if (h1 != h2)
119 spin_unlock(&nf_conntrack_locks[h2]);
120 }
121
122 /* return true if we need to recompute hashes (in case hash table was resized) */
123 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
124 unsigned int h2, unsigned int sequence)
125 {
126 h1 %= CONNTRACK_LOCKS;
127 h2 %= CONNTRACK_LOCKS;
128 if (h1 <= h2) {
129 nf_conntrack_lock(&nf_conntrack_locks[h1]);
130 if (h1 != h2)
131 spin_lock_nested(&nf_conntrack_locks[h2],
132 SINGLE_DEPTH_NESTING);
133 } else {
134 nf_conntrack_lock(&nf_conntrack_locks[h2]);
135 spin_lock_nested(&nf_conntrack_locks[h1],
136 SINGLE_DEPTH_NESTING);
137 }
138 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
139 nf_conntrack_double_unlock(h1, h2);
140 return true;
141 }
142 return false;
143 }
144
145 static void nf_conntrack_all_lock(void)
146 {
147 int i;
148
149 spin_lock(&nf_conntrack_locks_all_lock);
150
151 nf_conntrack_locks_all = true;
152
153 for (i = 0; i < CONNTRACK_LOCKS; i++) {
154 spin_lock(&nf_conntrack_locks[i]);
155
156 /* This spin_unlock provides the "release" to ensure that
157 * nf_conntrack_locks_all==true is visible to everyone that
158 * acquired spin_lock(&nf_conntrack_locks[]).
159 */
160 spin_unlock(&nf_conntrack_locks[i]);
161 }
162 }
163
164 static void nf_conntrack_all_unlock(void)
165 {
166 /* All prior stores must be complete before we clear
167 * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
168 * might observe the false value but not the entire
169 * critical section.
170 * It pairs with the smp_load_acquire() in nf_conntrack_lock()
171 */
172 smp_store_release(&nf_conntrack_locks_all, false);
173 spin_unlock(&nf_conntrack_locks_all_lock);
174 }
175
176 unsigned int nf_conntrack_htable_size __read_mostly;
177 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
178
179 unsigned int nf_conntrack_max __read_mostly;
180 EXPORT_SYMBOL_GPL(nf_conntrack_max);
181 seqcount_t nf_conntrack_generation __read_mostly;
182 static unsigned int nf_conntrack_hash_rnd __read_mostly;
183
184 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
185 const struct net *net)
186 {
187 unsigned int n;
188 u32 seed;
189
190 get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
191
192 /* The direction must be ignored, so we hash everything up to the
193 * destination ports (which is a multiple of 4) and treat the last
194 * three bytes manually.
195 */
196 seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
197 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
198 return jhash2((u32 *)tuple, n, seed ^
199 (((__force __u16)tuple->dst.u.all << 16) |
200 tuple->dst.protonum));
201 }
202
203 static u32 scale_hash(u32 hash)
204 {
205 return reciprocal_scale(hash, nf_conntrack_htable_size);
206 }
207
208 static u32 __hash_conntrack(const struct net *net,
209 const struct nf_conntrack_tuple *tuple,
210 unsigned int size)
211 {
212 return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
213 }
214
215 static u32 hash_conntrack(const struct net *net,
216 const struct nf_conntrack_tuple *tuple)
217 {
218 return scale_hash(hash_conntrack_raw(tuple, net));
219 }
220
221 static bool nf_ct_get_tuple_ports(const struct sk_buff *skb,
222 unsigned int dataoff,
223 struct nf_conntrack_tuple *tuple)
224 { struct {
225 __be16 sport;
226 __be16 dport;
227 } _inet_hdr, *inet_hdr;
228
229 /* Actually only need first 4 bytes to get ports. */
230 inet_hdr = skb_header_pointer(skb, dataoff, sizeof(_inet_hdr), &_inet_hdr);
231 if (!inet_hdr)
232 return false;
233
234 tuple->src.u.udp.port = inet_hdr->sport;
235 tuple->dst.u.udp.port = inet_hdr->dport;
236 return true;
237 }
238
239 static bool
240 nf_ct_get_tuple(const struct sk_buff *skb,
241 unsigned int nhoff,
242 unsigned int dataoff,
243 u_int16_t l3num,
244 u_int8_t protonum,
245 struct net *net,
246 struct nf_conntrack_tuple *tuple)
247 {
248 unsigned int size;
249 const __be32 *ap;
250 __be32 _addrs[8];
251
252 memset(tuple, 0, sizeof(*tuple));
253
254 tuple->src.l3num = l3num;
255 switch (l3num) {
256 case NFPROTO_IPV4:
257 nhoff += offsetof(struct iphdr, saddr);
258 size = 2 * sizeof(__be32);
259 break;
260 case NFPROTO_IPV6:
261 nhoff += offsetof(struct ipv6hdr, saddr);
262 size = sizeof(_addrs);
263 break;
264 default:
265 return true;
266 }
267
268 ap = skb_header_pointer(skb, nhoff, size, _addrs);
269 if (!ap)
270 return false;
271
272 switch (l3num) {
273 case NFPROTO_IPV4:
274 tuple->src.u3.ip = ap[0];
275 tuple->dst.u3.ip = ap[1];
276 break;
277 case NFPROTO_IPV6:
278 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
279 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
280 break;
281 }
282
283 tuple->dst.protonum = protonum;
284 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
285
286 switch (protonum) {
287 #if IS_ENABLED(CONFIG_IPV6)
288 case IPPROTO_ICMPV6:
289 return icmpv6_pkt_to_tuple(skb, dataoff, net, tuple);
290 #endif
291 case IPPROTO_ICMP:
292 return icmp_pkt_to_tuple(skb, dataoff, net, tuple);
293 #ifdef CONFIG_NF_CT_PROTO_GRE
294 case IPPROTO_GRE:
295 return gre_pkt_to_tuple(skb, dataoff, net, tuple);
296 #endif
297 case IPPROTO_TCP:
298 case IPPROTO_UDP: /* fallthrough */
299 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
300 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
301 case IPPROTO_UDPLITE:
302 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
303 #endif
304 #ifdef CONFIG_NF_CT_PROTO_SCTP
305 case IPPROTO_SCTP:
306 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
307 #endif
308 #ifdef CONFIG_NF_CT_PROTO_DCCP
309 case IPPROTO_DCCP:
310 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
311 #endif
312 default:
313 break;
314 }
315
316 return true;
317 }
318
319 static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
320 u_int8_t *protonum)
321 {
322 int dataoff = -1;
323 const struct iphdr *iph;
324 struct iphdr _iph;
325
326 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
327 if (!iph)
328 return -1;
329
330 /* Conntrack defragments packets, we might still see fragments
331 * inside ICMP packets though.
332 */
333 if (iph->frag_off & htons(IP_OFFSET))
334 return -1;
335
336 dataoff = nhoff + (iph->ihl << 2);
337 *protonum = iph->protocol;
338
339 /* Check bogus IP headers */
340 if (dataoff > skb->len) {
341 pr_debug("bogus IPv4 packet: nhoff %u, ihl %u, skblen %u\n",
342 nhoff, iph->ihl << 2, skb->len);
343 return -1;
344 }
345 return dataoff;
346 }
347
348 #if IS_ENABLED(CONFIG_IPV6)
349 static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
350 u8 *protonum)
351 {
352 int protoff = -1;
353 unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
354 __be16 frag_off;
355 u8 nexthdr;
356
357 if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
358 &nexthdr, sizeof(nexthdr)) != 0) {
359 pr_debug("can't get nexthdr\n");
360 return -1;
361 }
362 protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
363 /*
364 * (protoff == skb->len) means the packet has not data, just
365 * IPv6 and possibly extensions headers, but it is tracked anyway
366 */
367 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
368 pr_debug("can't find proto in pkt\n");
369 return -1;
370 }
371
372 *protonum = nexthdr;
373 return protoff;
374 }
375 #endif
376
377 static int get_l4proto(const struct sk_buff *skb,
378 unsigned int nhoff, u8 pf, u8 *l4num)
379 {
380 switch (pf) {
381 case NFPROTO_IPV4:
382 return ipv4_get_l4proto(skb, nhoff, l4num);
383 #if IS_ENABLED(CONFIG_IPV6)
384 case NFPROTO_IPV6:
385 return ipv6_get_l4proto(skb, nhoff, l4num);
386 #endif
387 default:
388 *l4num = 0;
389 break;
390 }
391 return -1;
392 }
393
394 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
395 u_int16_t l3num,
396 struct net *net, struct nf_conntrack_tuple *tuple)
397 {
398 u8 protonum;
399 int protoff;
400
401 protoff = get_l4proto(skb, nhoff, l3num, &protonum);
402 if (protoff <= 0)
403 return false;
404
405 return nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple);
406 }
407 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
408
409 bool
410 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
411 const struct nf_conntrack_tuple *orig)
412 {
413 memset(inverse, 0, sizeof(*inverse));
414
415 inverse->src.l3num = orig->src.l3num;
416
417 switch (orig->src.l3num) {
418 case NFPROTO_IPV4:
419 inverse->src.u3.ip = orig->dst.u3.ip;
420 inverse->dst.u3.ip = orig->src.u3.ip;
421 break;
422 case NFPROTO_IPV6:
423 inverse->src.u3.in6 = orig->dst.u3.in6;
424 inverse->dst.u3.in6 = orig->src.u3.in6;
425 break;
426 default:
427 break;
428 }
429
430 inverse->dst.dir = !orig->dst.dir;
431
432 inverse->dst.protonum = orig->dst.protonum;
433
434 switch (orig->dst.protonum) {
435 case IPPROTO_ICMP:
436 return nf_conntrack_invert_icmp_tuple(inverse, orig);
437 #if IS_ENABLED(CONFIG_IPV6)
438 case IPPROTO_ICMPV6:
439 return nf_conntrack_invert_icmpv6_tuple(inverse, orig);
440 #endif
441 }
442
443 inverse->src.u.all = orig->dst.u.all;
444 inverse->dst.u.all = orig->src.u.all;
445 return true;
446 }
447 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
448
449 /* Generate a almost-unique pseudo-id for a given conntrack.
450 *
451 * intentionally doesn't re-use any of the seeds used for hash
452 * table location, we assume id gets exposed to userspace.
453 *
454 * Following nf_conn items do not change throughout lifetime
455 * of the nf_conn:
456 *
457 * 1. nf_conn address
458 * 2. nf_conn->master address (normally NULL)
459 * 3. the associated net namespace
460 * 4. the original direction tuple
461 */
462 u32 nf_ct_get_id(const struct nf_conn *ct)
463 {
464 static __read_mostly siphash_key_t ct_id_seed;
465 unsigned long a, b, c, d;
466
467 net_get_random_once(&ct_id_seed, sizeof(ct_id_seed));
468
469 a = (unsigned long)ct;
470 b = (unsigned long)ct->master;
471 c = (unsigned long)nf_ct_net(ct);
472 d = (unsigned long)siphash(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
473 sizeof(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple),
474 &ct_id_seed);
475 #ifdef CONFIG_64BIT
476 return siphash_4u64((u64)a, (u64)b, (u64)c, (u64)d, &ct_id_seed);
477 #else
478 return siphash_4u32((u32)a, (u32)b, (u32)c, (u32)d, &ct_id_seed);
479 #endif
480 }
481 EXPORT_SYMBOL_GPL(nf_ct_get_id);
482
483 static void
484 clean_from_lists(struct nf_conn *ct)
485 {
486 pr_debug("clean_from_lists(%p)\n", ct);
487 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
488 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
489
490 /* Destroy all pending expectations */
491 nf_ct_remove_expectations(ct);
492 }
493
494 /* must be called with local_bh_disable */
495 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
496 {
497 struct ct_pcpu *pcpu;
498
499 /* add this conntrack to the (per cpu) dying list */
500 ct->cpu = smp_processor_id();
501 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
502
503 spin_lock(&pcpu->lock);
504 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
505 &pcpu->dying);
506 spin_unlock(&pcpu->lock);
507 }
508
509 /* must be called with local_bh_disable */
510 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
511 {
512 struct ct_pcpu *pcpu;
513
514 /* add this conntrack to the (per cpu) unconfirmed list */
515 ct->cpu = smp_processor_id();
516 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
517
518 spin_lock(&pcpu->lock);
519 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
520 &pcpu->unconfirmed);
521 spin_unlock(&pcpu->lock);
522 }
523
524 /* must be called with local_bh_disable */
525 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
526 {
527 struct ct_pcpu *pcpu;
528
529 /* We overload first tuple to link into unconfirmed or dying list.*/
530 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
531
532 spin_lock(&pcpu->lock);
533 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
534 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
535 spin_unlock(&pcpu->lock);
536 }
537
538 #define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
539
540 /* Released via destroy_conntrack() */
541 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
542 const struct nf_conntrack_zone *zone,
543 gfp_t flags)
544 {
545 struct nf_conn *tmpl, *p;
546
547 if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) {
548 tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags);
549 if (!tmpl)
550 return NULL;
551
552 p = tmpl;
553 tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
554 if (tmpl != p) {
555 tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
556 tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p;
557 }
558 } else {
559 tmpl = kzalloc(sizeof(*tmpl), flags);
560 if (!tmpl)
561 return NULL;
562 }
563
564 tmpl->status = IPS_TEMPLATE;
565 write_pnet(&tmpl->ct_net, net);
566 nf_ct_zone_add(tmpl, zone);
567 atomic_set(&tmpl->ct_general.use, 0);
568
569 return tmpl;
570 }
571 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
572
573 void nf_ct_tmpl_free(struct nf_conn *tmpl)
574 {
575 nf_ct_ext_destroy(tmpl);
576
577 if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK)
578 kfree((char *)tmpl - tmpl->proto.tmpl_padto);
579 else
580 kfree(tmpl);
581 }
582 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
583
584 static void destroy_gre_conntrack(struct nf_conn *ct)
585 {
586 #ifdef CONFIG_NF_CT_PROTO_GRE
587 struct nf_conn *master = ct->master;
588
589 if (master)
590 nf_ct_gre_keymap_destroy(master);
591 #endif
592 }
593
594 static void
595 destroy_conntrack(struct nf_conntrack *nfct)
596 {
597 struct nf_conn *ct = (struct nf_conn *)nfct;
598
599 pr_debug("destroy_conntrack(%p)\n", ct);
600 WARN_ON(atomic_read(&nfct->use) != 0);
601
602 if (unlikely(nf_ct_is_template(ct))) {
603 nf_ct_tmpl_free(ct);
604 return;
605 }
606
607 if (unlikely(nf_ct_protonum(ct) == IPPROTO_GRE))
608 destroy_gre_conntrack(ct);
609
610 local_bh_disable();
611 /* Expectations will have been removed in clean_from_lists,
612 * except TFTP can create an expectation on the first packet,
613 * before connection is in the list, so we need to clean here,
614 * too.
615 */
616 nf_ct_remove_expectations(ct);
617
618 nf_ct_del_from_dying_or_unconfirmed_list(ct);
619
620 local_bh_enable();
621
622 if (ct->master)
623 nf_ct_put(ct->master);
624
625 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
626 nf_conntrack_free(ct);
627 }
628
629 static void nf_ct_delete_from_lists(struct nf_conn *ct)
630 {
631 struct net *net = nf_ct_net(ct);
632 unsigned int hash, reply_hash;
633 unsigned int sequence;
634
635 nf_ct_helper_destroy(ct);
636
637 local_bh_disable();
638 do {
639 sequence = read_seqcount_begin(&nf_conntrack_generation);
640 hash = hash_conntrack(net,
641 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
642 reply_hash = hash_conntrack(net,
643 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
644 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
645
646 clean_from_lists(ct);
647 nf_conntrack_double_unlock(hash, reply_hash);
648
649 nf_ct_add_to_dying_list(ct);
650
651 local_bh_enable();
652 }
653
654 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
655 {
656 struct nf_conn_tstamp *tstamp;
657
658 if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
659 return false;
660
661 tstamp = nf_conn_tstamp_find(ct);
662 if (tstamp && tstamp->stop == 0)
663 tstamp->stop = ktime_get_real_ns();
664
665 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
666 portid, report) < 0) {
667 /* destroy event was not delivered. nf_ct_put will
668 * be done by event cache worker on redelivery.
669 */
670 nf_ct_delete_from_lists(ct);
671 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
672 return false;
673 }
674
675 nf_conntrack_ecache_work(nf_ct_net(ct));
676 nf_ct_delete_from_lists(ct);
677 nf_ct_put(ct);
678 return true;
679 }
680 EXPORT_SYMBOL_GPL(nf_ct_delete);
681
682 static inline bool
683 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
684 const struct nf_conntrack_tuple *tuple,
685 const struct nf_conntrack_zone *zone,
686 const struct net *net)
687 {
688 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
689
690 /* A conntrack can be recreated with the equal tuple,
691 * so we need to check that the conntrack is confirmed
692 */
693 return nf_ct_tuple_equal(tuple, &h->tuple) &&
694 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
695 nf_ct_is_confirmed(ct) &&
696 net_eq(net, nf_ct_net(ct));
697 }
698
699 static inline bool
700 nf_ct_match(const struct nf_conn *ct1, const struct nf_conn *ct2)
701 {
702 return nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
703 &ct2->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
704 nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_REPLY].tuple,
705 &ct2->tuplehash[IP_CT_DIR_REPLY].tuple) &&
706 nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_ORIGINAL) &&
707 nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_REPLY) &&
708 net_eq(nf_ct_net(ct1), nf_ct_net(ct2));
709 }
710
711 /* caller must hold rcu readlock and none of the nf_conntrack_locks */
712 static void nf_ct_gc_expired(struct nf_conn *ct)
713 {
714 if (!atomic_inc_not_zero(&ct->ct_general.use))
715 return;
716
717 if (nf_ct_should_gc(ct))
718 nf_ct_kill(ct);
719
720 nf_ct_put(ct);
721 }
722
723 /*
724 * Warning :
725 * - Caller must take a reference on returned object
726 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
727 */
728 static struct nf_conntrack_tuple_hash *
729 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
730 const struct nf_conntrack_tuple *tuple, u32 hash)
731 {
732 struct nf_conntrack_tuple_hash *h;
733 struct hlist_nulls_head *ct_hash;
734 struct hlist_nulls_node *n;
735 unsigned int bucket, hsize;
736
737 begin:
738 nf_conntrack_get_ht(&ct_hash, &hsize);
739 bucket = reciprocal_scale(hash, hsize);
740
741 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
742 struct nf_conn *ct;
743
744 ct = nf_ct_tuplehash_to_ctrack(h);
745 if (nf_ct_is_expired(ct)) {
746 nf_ct_gc_expired(ct);
747 continue;
748 }
749
750 if (nf_ct_key_equal(h, tuple, zone, net))
751 return h;
752 }
753 /*
754 * if the nulls value we got at the end of this lookup is
755 * not the expected one, we must restart lookup.
756 * We probably met an item that was moved to another chain.
757 */
758 if (get_nulls_value(n) != bucket) {
759 NF_CT_STAT_INC_ATOMIC(net, search_restart);
760 goto begin;
761 }
762
763 return NULL;
764 }
765
766 /* Find a connection corresponding to a tuple. */
767 static struct nf_conntrack_tuple_hash *
768 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
769 const struct nf_conntrack_tuple *tuple, u32 hash)
770 {
771 struct nf_conntrack_tuple_hash *h;
772 struct nf_conn *ct;
773
774 rcu_read_lock();
775
776 h = ____nf_conntrack_find(net, zone, tuple, hash);
777 if (h) {
778 /* We have a candidate that matches the tuple we're interested
779 * in, try to obtain a reference and re-check tuple
780 */
781 ct = nf_ct_tuplehash_to_ctrack(h);
782 if (likely(atomic_inc_not_zero(&ct->ct_general.use))) {
783 if (likely(nf_ct_key_equal(h, tuple, zone, net)))
784 goto found;
785
786 /* TYPESAFE_BY_RCU recycled the candidate */
787 nf_ct_put(ct);
788 }
789
790 h = NULL;
791 }
792 found:
793 rcu_read_unlock();
794
795 return h;
796 }
797
798 struct nf_conntrack_tuple_hash *
799 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
800 const struct nf_conntrack_tuple *tuple)
801 {
802 return __nf_conntrack_find_get(net, zone, tuple,
803 hash_conntrack_raw(tuple, net));
804 }
805 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
806
807 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
808 unsigned int hash,
809 unsigned int reply_hash)
810 {
811 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
812 &nf_conntrack_hash[hash]);
813 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
814 &nf_conntrack_hash[reply_hash]);
815 }
816
817 int
818 nf_conntrack_hash_check_insert(struct nf_conn *ct)
819 {
820 const struct nf_conntrack_zone *zone;
821 struct net *net = nf_ct_net(ct);
822 unsigned int hash, reply_hash;
823 struct nf_conntrack_tuple_hash *h;
824 struct hlist_nulls_node *n;
825 unsigned int sequence;
826
827 zone = nf_ct_zone(ct);
828
829 local_bh_disable();
830 do {
831 sequence = read_seqcount_begin(&nf_conntrack_generation);
832 hash = hash_conntrack(net,
833 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
834 reply_hash = hash_conntrack(net,
835 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
836 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
837
838 /* See if there's one in the list already, including reverse */
839 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
840 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
841 zone, net))
842 goto out;
843
844 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
845 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
846 zone, net))
847 goto out;
848
849 smp_wmb();
850 /* The caller holds a reference to this object */
851 atomic_set(&ct->ct_general.use, 2);
852 __nf_conntrack_hash_insert(ct, hash, reply_hash);
853 nf_conntrack_double_unlock(hash, reply_hash);
854 NF_CT_STAT_INC(net, insert);
855 local_bh_enable();
856 return 0;
857
858 out:
859 nf_conntrack_double_unlock(hash, reply_hash);
860 NF_CT_STAT_INC(net, insert_failed);
861 local_bh_enable();
862 return -EEXIST;
863 }
864 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
865
866 static inline void nf_ct_acct_update(struct nf_conn *ct,
867 enum ip_conntrack_info ctinfo,
868 unsigned int len)
869 {
870 struct nf_conn_acct *acct;
871
872 acct = nf_conn_acct_find(ct);
873 if (acct) {
874 struct nf_conn_counter *counter = acct->counter;
875
876 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
877 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
878 }
879 }
880
881 static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
882 const struct nf_conn *loser_ct)
883 {
884 struct nf_conn_acct *acct;
885
886 acct = nf_conn_acct_find(loser_ct);
887 if (acct) {
888 struct nf_conn_counter *counter = acct->counter;
889 unsigned int bytes;
890
891 /* u32 should be fine since we must have seen one packet. */
892 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
893 nf_ct_acct_update(ct, ctinfo, bytes);
894 }
895 }
896
897 /* Resolve race on insertion if this protocol allows this. */
898 static __cold noinline int
899 nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
900 enum ip_conntrack_info ctinfo,
901 struct nf_conntrack_tuple_hash *h)
902 {
903 /* This is the conntrack entry already in hashes that won race. */
904 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
905 const struct nf_conntrack_l4proto *l4proto;
906 enum ip_conntrack_info oldinfo;
907 struct nf_conn *loser_ct = nf_ct_get(skb, &oldinfo);
908
909 l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
910 if (l4proto->allow_clash &&
911 !nf_ct_is_dying(ct) &&
912 atomic_inc_not_zero(&ct->ct_general.use)) {
913 if (((ct->status & IPS_NAT_DONE_MASK) == 0) ||
914 nf_ct_match(ct, loser_ct)) {
915 nf_ct_acct_merge(ct, ctinfo, loser_ct);
916 nf_conntrack_put(&loser_ct->ct_general);
917 nf_ct_set(skb, ct, oldinfo);
918 return NF_ACCEPT;
919 }
920 nf_ct_put(ct);
921 }
922 NF_CT_STAT_INC(net, drop);
923 return NF_DROP;
924 }
925
926 /* Confirm a connection given skb; places it in hash table */
927 int
928 __nf_conntrack_confirm(struct sk_buff *skb)
929 {
930 const struct nf_conntrack_zone *zone;
931 unsigned int hash, reply_hash;
932 struct nf_conntrack_tuple_hash *h;
933 struct nf_conn *ct;
934 struct nf_conn_help *help;
935 struct nf_conn_tstamp *tstamp;
936 struct hlist_nulls_node *n;
937 enum ip_conntrack_info ctinfo;
938 struct net *net;
939 unsigned int sequence;
940 int ret = NF_DROP;
941
942 ct = nf_ct_get(skb, &ctinfo);
943 net = nf_ct_net(ct);
944
945 /* ipt_REJECT uses nf_conntrack_attach to attach related
946 ICMP/TCP RST packets in other direction. Actual packet
947 which created connection will be IP_CT_NEW or for an
948 expected connection, IP_CT_RELATED. */
949 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
950 return NF_ACCEPT;
951
952 zone = nf_ct_zone(ct);
953 local_bh_disable();
954
955 do {
956 sequence = read_seqcount_begin(&nf_conntrack_generation);
957 /* reuse the hash saved before */
958 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
959 hash = scale_hash(hash);
960 reply_hash = hash_conntrack(net,
961 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
962
963 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
964
965 /* We're not in hash table, and we refuse to set up related
966 * connections for unconfirmed conns. But packet copies and
967 * REJECT will give spurious warnings here.
968 */
969
970 /* Another skb with the same unconfirmed conntrack may
971 * win the race. This may happen for bridge(br_flood)
972 * or broadcast/multicast packets do skb_clone with
973 * unconfirmed conntrack.
974 */
975 if (unlikely(nf_ct_is_confirmed(ct))) {
976 WARN_ON_ONCE(1);
977 nf_conntrack_double_unlock(hash, reply_hash);
978 local_bh_enable();
979 return NF_DROP;
980 }
981
982 pr_debug("Confirming conntrack %p\n", ct);
983 /* We have to check the DYING flag after unlink to prevent
984 * a race against nf_ct_get_next_corpse() possibly called from
985 * user context, else we insert an already 'dead' hash, blocking
986 * further use of that particular connection -JM.
987 */
988 nf_ct_del_from_dying_or_unconfirmed_list(ct);
989
990 if (unlikely(nf_ct_is_dying(ct))) {
991 nf_ct_add_to_dying_list(ct);
992 goto dying;
993 }
994
995 /* See if there's one in the list already, including reverse:
996 NAT could have grabbed it without realizing, since we're
997 not in the hash. If there is, we lost race. */
998 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
999 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
1000 zone, net))
1001 goto out;
1002
1003 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
1004 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
1005 zone, net))
1006 goto out;
1007
1008 /* Timer relative to confirmation time, not original
1009 setting time, otherwise we'd get timer wrap in
1010 weird delay cases. */
1011 ct->timeout += nfct_time_stamp;
1012 atomic_inc(&ct->ct_general.use);
1013 ct->status |= IPS_CONFIRMED;
1014
1015 /* set conntrack timestamp, if enabled. */
1016 tstamp = nf_conn_tstamp_find(ct);
1017 if (tstamp)
1018 tstamp->start = ktime_get_real_ns();
1019
1020 /* Since the lookup is lockless, hash insertion must be done after
1021 * starting the timer and setting the CONFIRMED bit. The RCU barriers
1022 * guarantee that no other CPU can find the conntrack before the above
1023 * stores are visible.
1024 */
1025 __nf_conntrack_hash_insert(ct, hash, reply_hash);
1026 nf_conntrack_double_unlock(hash, reply_hash);
1027 local_bh_enable();
1028
1029 help = nfct_help(ct);
1030 if (help && help->helper)
1031 nf_conntrack_event_cache(IPCT_HELPER, ct);
1032
1033 nf_conntrack_event_cache(master_ct(ct) ?
1034 IPCT_RELATED : IPCT_NEW, ct);
1035 return NF_ACCEPT;
1036
1037 out:
1038 nf_ct_add_to_dying_list(ct);
1039 ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
1040 dying:
1041 nf_conntrack_double_unlock(hash, reply_hash);
1042 NF_CT_STAT_INC(net, insert_failed);
1043 local_bh_enable();
1044 return ret;
1045 }
1046 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
1047
1048 /* Returns true if a connection correspondings to the tuple (required
1049 for NAT). */
1050 int
1051 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
1052 const struct nf_conn *ignored_conntrack)
1053 {
1054 struct net *net = nf_ct_net(ignored_conntrack);
1055 const struct nf_conntrack_zone *zone;
1056 struct nf_conntrack_tuple_hash *h;
1057 struct hlist_nulls_head *ct_hash;
1058 unsigned int hash, hsize;
1059 struct hlist_nulls_node *n;
1060 struct nf_conn *ct;
1061
1062 zone = nf_ct_zone(ignored_conntrack);
1063
1064 rcu_read_lock();
1065 begin:
1066 nf_conntrack_get_ht(&ct_hash, &hsize);
1067 hash = __hash_conntrack(net, tuple, hsize);
1068
1069 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
1070 ct = nf_ct_tuplehash_to_ctrack(h);
1071
1072 if (ct == ignored_conntrack)
1073 continue;
1074
1075 if (nf_ct_is_expired(ct)) {
1076 nf_ct_gc_expired(ct);
1077 continue;
1078 }
1079
1080 if (nf_ct_key_equal(h, tuple, zone, net)) {
1081 /* Tuple is taken already, so caller will need to find
1082 * a new source port to use.
1083 *
1084 * Only exception:
1085 * If the *original tuples* are identical, then both
1086 * conntracks refer to the same flow.
1087 * This is a rare situation, it can occur e.g. when
1088 * more than one UDP packet is sent from same socket
1089 * in different threads.
1090 *
1091 * Let nf_ct_resolve_clash() deal with this later.
1092 */
1093 if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
1094 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple))
1095 continue;
1096
1097 NF_CT_STAT_INC_ATOMIC(net, found);
1098 rcu_read_unlock();
1099 return 1;
1100 }
1101 }
1102
1103 if (get_nulls_value(n) != hash) {
1104 NF_CT_STAT_INC_ATOMIC(net, search_restart);
1105 goto begin;
1106 }
1107
1108 rcu_read_unlock();
1109
1110 return 0;
1111 }
1112 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
1113
1114 #define NF_CT_EVICTION_RANGE 8
1115
1116 /* There's a small race here where we may free a just-assured
1117 connection. Too bad: we're in trouble anyway. */
1118 static unsigned int early_drop_list(struct net *net,
1119 struct hlist_nulls_head *head)
1120 {
1121 struct nf_conntrack_tuple_hash *h;
1122 struct hlist_nulls_node *n;
1123 unsigned int drops = 0;
1124 struct nf_conn *tmp;
1125
1126 hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
1127 tmp = nf_ct_tuplehash_to_ctrack(h);
1128
1129 if (test_bit(IPS_OFFLOAD_BIT, &tmp->status))
1130 continue;
1131
1132 if (nf_ct_is_expired(tmp)) {
1133 nf_ct_gc_expired(tmp);
1134 continue;
1135 }
1136
1137 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
1138 !net_eq(nf_ct_net(tmp), net) ||
1139 nf_ct_is_dying(tmp))
1140 continue;
1141
1142 if (!atomic_inc_not_zero(&tmp->ct_general.use))
1143 continue;
1144
1145 /* kill only if still in same netns -- might have moved due to
1146 * SLAB_TYPESAFE_BY_RCU rules.
1147 *
1148 * We steal the timer reference. If that fails timer has
1149 * already fired or someone else deleted it. Just drop ref
1150 * and move to next entry.
1151 */
1152 if (net_eq(nf_ct_net(tmp), net) &&
1153 nf_ct_is_confirmed(tmp) &&
1154 nf_ct_delete(tmp, 0, 0))
1155 drops++;
1156
1157 nf_ct_put(tmp);
1158 }
1159
1160 return drops;
1161 }
1162
1163 static noinline int early_drop(struct net *net, unsigned int hash)
1164 {
1165 unsigned int i, bucket;
1166
1167 for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
1168 struct hlist_nulls_head *ct_hash;
1169 unsigned int hsize, drops;
1170
1171 rcu_read_lock();
1172 nf_conntrack_get_ht(&ct_hash, &hsize);
1173 if (!i)
1174 bucket = reciprocal_scale(hash, hsize);
1175 else
1176 bucket = (bucket + 1) % hsize;
1177
1178 drops = early_drop_list(net, &ct_hash[bucket]);
1179 rcu_read_unlock();
1180
1181 if (drops) {
1182 NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
1183 return true;
1184 }
1185 }
1186
1187 return false;
1188 }
1189
1190 static bool gc_worker_skip_ct(const struct nf_conn *ct)
1191 {
1192 return !nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct);
1193 }
1194
1195 static bool gc_worker_can_early_drop(const struct nf_conn *ct)
1196 {
1197 const struct nf_conntrack_l4proto *l4proto;
1198
1199 if (!test_bit(IPS_ASSURED_BIT, &ct->status))
1200 return true;
1201
1202 l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
1203 if (l4proto->can_early_drop && l4proto->can_early_drop(ct))
1204 return true;
1205
1206 return false;
1207 }
1208
1209 #define DAY (86400 * HZ)
1210
1211 /* Set an arbitrary timeout large enough not to ever expire, this save
1212 * us a check for the IPS_OFFLOAD_BIT from the packet path via
1213 * nf_ct_is_expired().
1214 */
1215 static void nf_ct_offload_timeout(struct nf_conn *ct)
1216 {
1217 if (nf_ct_expires(ct) < DAY / 2)
1218 ct->timeout = nfct_time_stamp + DAY;
1219 }
1220
1221 static void gc_worker(struct work_struct *work)
1222 {
1223 unsigned int min_interval = max(HZ / GC_MAX_BUCKETS_DIV, 1u);
1224 unsigned int i, goal, buckets = 0, expired_count = 0;
1225 unsigned int nf_conntrack_max95 = 0;
1226 struct conntrack_gc_work *gc_work;
1227 unsigned int ratio, scanned = 0;
1228 unsigned long next_run;
1229
1230 gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
1231
1232 goal = nf_conntrack_htable_size / GC_MAX_BUCKETS_DIV;
1233 i = gc_work->last_bucket;
1234 if (gc_work->early_drop)
1235 nf_conntrack_max95 = nf_conntrack_max / 100u * 95u;
1236
1237 do {
1238 struct nf_conntrack_tuple_hash *h;
1239 struct hlist_nulls_head *ct_hash;
1240 struct hlist_nulls_node *n;
1241 unsigned int hashsz;
1242 struct nf_conn *tmp;
1243
1244 i++;
1245 rcu_read_lock();
1246
1247 nf_conntrack_get_ht(&ct_hash, &hashsz);
1248 if (i >= hashsz)
1249 i = 0;
1250
1251 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
1252 struct net *net;
1253
1254 tmp = nf_ct_tuplehash_to_ctrack(h);
1255
1256 scanned++;
1257 if (test_bit(IPS_OFFLOAD_BIT, &tmp->status)) {
1258 nf_ct_offload_timeout(tmp);
1259 continue;
1260 }
1261
1262 if (nf_ct_is_expired(tmp)) {
1263 nf_ct_gc_expired(tmp);
1264 expired_count++;
1265 continue;
1266 }
1267
1268 if (nf_conntrack_max95 == 0 || gc_worker_skip_ct(tmp))
1269 continue;
1270
1271 net = nf_ct_net(tmp);
1272 if (atomic_read(&net->ct.count) < nf_conntrack_max95)
1273 continue;
1274
1275 /* need to take reference to avoid possible races */
1276 if (!atomic_inc_not_zero(&tmp->ct_general.use))
1277 continue;
1278
1279 if (gc_worker_skip_ct(tmp)) {
1280 nf_ct_put(tmp);
1281 continue;
1282 }
1283
1284 if (gc_worker_can_early_drop(tmp))
1285 nf_ct_kill(tmp);
1286
1287 nf_ct_put(tmp);
1288 }
1289
1290 /* could check get_nulls_value() here and restart if ct
1291 * was moved to another chain. But given gc is best-effort
1292 * we will just continue with next hash slot.
1293 */
1294 rcu_read_unlock();
1295 cond_resched();
1296 } while (++buckets < goal);
1297
1298 if (gc_work->exiting)
1299 return;
1300
1301 /*
1302 * Eviction will normally happen from the packet path, and not
1303 * from this gc worker.
1304 *
1305 * This worker is only here to reap expired entries when system went
1306 * idle after a busy period.
1307 *
1308 * The heuristics below are supposed to balance conflicting goals:
1309 *
1310 * 1. Minimize time until we notice a stale entry
1311 * 2. Maximize scan intervals to not waste cycles
1312 *
1313 * Normally, expire ratio will be close to 0.
1314 *
1315 * As soon as a sizeable fraction of the entries have expired
1316 * increase scan frequency.
1317 */
1318 ratio = scanned ? expired_count * 100 / scanned : 0;
1319 if (ratio > GC_EVICT_RATIO) {
1320 gc_work->next_gc_run = min_interval;
1321 } else {
1322 unsigned int max = GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV;
1323
1324 BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV) == 0);
1325
1326 gc_work->next_gc_run += min_interval;
1327 if (gc_work->next_gc_run > max)
1328 gc_work->next_gc_run = max;
1329 }
1330
1331 next_run = gc_work->next_gc_run;
1332 gc_work->last_bucket = i;
1333 gc_work->early_drop = false;
1334 queue_delayed_work(system_power_efficient_wq, &gc_work->dwork, next_run);
1335 }
1336
1337 static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
1338 {
1339 INIT_DEFERRABLE_WORK(&gc_work->dwork, gc_worker);
1340 gc_work->next_gc_run = HZ;
1341 gc_work->exiting = false;
1342 }
1343
1344 static struct nf_conn *
1345 __nf_conntrack_alloc(struct net *net,
1346 const struct nf_conntrack_zone *zone,
1347 const struct nf_conntrack_tuple *orig,
1348 const struct nf_conntrack_tuple *repl,
1349 gfp_t gfp, u32 hash)
1350 {
1351 struct nf_conn *ct;
1352
1353 /* We don't want any race condition at early drop stage */
1354 atomic_inc(&net->ct.count);
1355
1356 if (nf_conntrack_max &&
1357 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
1358 if (!early_drop(net, hash)) {
1359 if (!conntrack_gc_work.early_drop)
1360 conntrack_gc_work.early_drop = true;
1361 atomic_dec(&net->ct.count);
1362 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
1363 return ERR_PTR(-ENOMEM);
1364 }
1365 }
1366
1367 /*
1368 * Do not use kmem_cache_zalloc(), as this cache uses
1369 * SLAB_TYPESAFE_BY_RCU.
1370 */
1371 ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
1372 if (ct == NULL)
1373 goto out;
1374
1375 spin_lock_init(&ct->lock);
1376 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
1377 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
1378 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
1379 /* save hash for reusing when confirming */
1380 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
1381 ct->status = 0;
1382 ct->timeout = 0;
1383 write_pnet(&ct->ct_net, net);
1384 memset(&ct->__nfct_init_offset[0], 0,
1385 offsetof(struct nf_conn, proto) -
1386 offsetof(struct nf_conn, __nfct_init_offset[0]));
1387
1388 nf_ct_zone_add(ct, zone);
1389
1390 /* Because we use RCU lookups, we set ct_general.use to zero before
1391 * this is inserted in any list.
1392 */
1393 atomic_set(&ct->ct_general.use, 0);
1394 return ct;
1395 out:
1396 atomic_dec(&net->ct.count);
1397 return ERR_PTR(-ENOMEM);
1398 }
1399
1400 struct nf_conn *nf_conntrack_alloc(struct net *net,
1401 const struct nf_conntrack_zone *zone,
1402 const struct nf_conntrack_tuple *orig,
1403 const struct nf_conntrack_tuple *repl,
1404 gfp_t gfp)
1405 {
1406 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
1407 }
1408 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
1409
1410 void nf_conntrack_free(struct nf_conn *ct)
1411 {
1412 struct net *net = nf_ct_net(ct);
1413
1414 /* A freed object has refcnt == 0, that's
1415 * the golden rule for SLAB_TYPESAFE_BY_RCU
1416 */
1417 WARN_ON(atomic_read(&ct->ct_general.use) != 0);
1418
1419 nf_ct_ext_destroy(ct);
1420 kmem_cache_free(nf_conntrack_cachep, ct);
1421 smp_mb__before_atomic();
1422 atomic_dec(&net->ct.count);
1423 }
1424 EXPORT_SYMBOL_GPL(nf_conntrack_free);
1425
1426
1427 /* Allocate a new conntrack: we return -ENOMEM if classification
1428 failed due to stress. Otherwise it really is unclassifiable. */
1429 static noinline struct nf_conntrack_tuple_hash *
1430 init_conntrack(struct net *net, struct nf_conn *tmpl,
1431 const struct nf_conntrack_tuple *tuple,
1432 struct sk_buff *skb,
1433 unsigned int dataoff, u32 hash)
1434 {
1435 struct nf_conn *ct;
1436 struct nf_conn_help *help;
1437 struct nf_conntrack_tuple repl_tuple;
1438 struct nf_conntrack_ecache *ecache;
1439 struct nf_conntrack_expect *exp = NULL;
1440 const struct nf_conntrack_zone *zone;
1441 struct nf_conn_timeout *timeout_ext;
1442 struct nf_conntrack_zone tmp;
1443
1444 if (!nf_ct_invert_tuple(&repl_tuple, tuple)) {
1445 pr_debug("Can't invert tuple.\n");
1446 return NULL;
1447 }
1448
1449 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1450 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1451 hash);
1452 if (IS_ERR(ct))
1453 return (struct nf_conntrack_tuple_hash *)ct;
1454
1455 if (!nf_ct_add_synproxy(ct, tmpl)) {
1456 nf_conntrack_free(ct);
1457 return ERR_PTR(-ENOMEM);
1458 }
1459
1460 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1461
1462 if (timeout_ext)
1463 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1464 GFP_ATOMIC);
1465
1466 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1467 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1468 nf_ct_labels_ext_add(ct);
1469
1470 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1471 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1472 ecache ? ecache->expmask : 0,
1473 GFP_ATOMIC);
1474
1475 local_bh_disable();
1476 if (net->ct.expect_count) {
1477 spin_lock(&nf_conntrack_expect_lock);
1478 exp = nf_ct_find_expectation(net, zone, tuple);
1479 if (exp) {
1480 pr_debug("expectation arrives ct=%p exp=%p\n",
1481 ct, exp);
1482 /* Welcome, Mr. Bond. We've been expecting you... */
1483 __set_bit(IPS_EXPECTED_BIT, &ct->status);
1484 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1485 ct->master = exp->master;
1486 if (exp->helper) {
1487 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
1488 if (help)
1489 rcu_assign_pointer(help->helper, exp->helper);
1490 }
1491
1492 #ifdef CONFIG_NF_CONNTRACK_MARK
1493 ct->mark = exp->master->mark;
1494 #endif
1495 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1496 ct->secmark = exp->master->secmark;
1497 #endif
1498 NF_CT_STAT_INC(net, expect_new);
1499 }
1500 spin_unlock(&nf_conntrack_expect_lock);
1501 }
1502 if (!exp)
1503 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1504
1505 /* Now it is inserted into the unconfirmed list, bump refcount */
1506 nf_conntrack_get(&ct->ct_general);
1507 nf_ct_add_to_unconfirmed_list(ct);
1508
1509 local_bh_enable();
1510
1511 if (exp) {
1512 if (exp->expectfn)
1513 exp->expectfn(ct, exp);
1514 nf_ct_expect_put(exp);
1515 }
1516
1517 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1518 }
1519
1520 /* On success, returns 0, sets skb->_nfct | ctinfo */
1521 static int
1522 resolve_normal_ct(struct nf_conn *tmpl,
1523 struct sk_buff *skb,
1524 unsigned int dataoff,
1525 u_int8_t protonum,
1526 const struct nf_hook_state *state)
1527 {
1528 const struct nf_conntrack_zone *zone;
1529 struct nf_conntrack_tuple tuple;
1530 struct nf_conntrack_tuple_hash *h;
1531 enum ip_conntrack_info ctinfo;
1532 struct nf_conntrack_zone tmp;
1533 struct nf_conn *ct;
1534 u32 hash;
1535
1536 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1537 dataoff, state->pf, protonum, state->net,
1538 &tuple)) {
1539 pr_debug("Can't get tuple\n");
1540 return 0;
1541 }
1542
1543 /* look for tuple match */
1544 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1545 hash = hash_conntrack_raw(&tuple, state->net);
1546 h = __nf_conntrack_find_get(state->net, zone, &tuple, hash);
1547 if (!h) {
1548 h = init_conntrack(state->net, tmpl, &tuple,
1549 skb, dataoff, hash);
1550 if (!h)
1551 return 0;
1552 if (IS_ERR(h))
1553 return PTR_ERR(h);
1554 }
1555 ct = nf_ct_tuplehash_to_ctrack(h);
1556
1557 /* It exists; we have (non-exclusive) reference. */
1558 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1559 ctinfo = IP_CT_ESTABLISHED_REPLY;
1560 } else {
1561 /* Once we've had two way comms, always ESTABLISHED. */
1562 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1563 pr_debug("normal packet for %p\n", ct);
1564 ctinfo = IP_CT_ESTABLISHED;
1565 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1566 pr_debug("related packet for %p\n", ct);
1567 ctinfo = IP_CT_RELATED;
1568 } else {
1569 pr_debug("new packet for %p\n", ct);
1570 ctinfo = IP_CT_NEW;
1571 }
1572 }
1573 nf_ct_set(skb, ct, ctinfo);
1574 return 0;
1575 }
1576
1577 /*
1578 * icmp packets need special treatment to handle error messages that are
1579 * related to a connection.
1580 *
1581 * Callers need to check if skb has a conntrack assigned when this
1582 * helper returns; in such case skb belongs to an already known connection.
1583 */
1584 static unsigned int __cold
1585 nf_conntrack_handle_icmp(struct nf_conn *tmpl,
1586 struct sk_buff *skb,
1587 unsigned int dataoff,
1588 u8 protonum,
1589 const struct nf_hook_state *state)
1590 {
1591 int ret;
1592
1593 if (state->pf == NFPROTO_IPV4 && protonum == IPPROTO_ICMP)
1594 ret = nf_conntrack_icmpv4_error(tmpl, skb, dataoff, state);
1595 #if IS_ENABLED(CONFIG_IPV6)
1596 else if (state->pf == NFPROTO_IPV6 && protonum == IPPROTO_ICMPV6)
1597 ret = nf_conntrack_icmpv6_error(tmpl, skb, dataoff, state);
1598 #endif
1599 else
1600 return NF_ACCEPT;
1601
1602 if (ret <= 0) {
1603 NF_CT_STAT_INC_ATOMIC(state->net, error);
1604 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1605 }
1606
1607 return ret;
1608 }
1609
1610 static int generic_packet(struct nf_conn *ct, struct sk_buff *skb,
1611 enum ip_conntrack_info ctinfo)
1612 {
1613 const unsigned int *timeout = nf_ct_timeout_lookup(ct);
1614
1615 if (!timeout)
1616 timeout = &nf_generic_pernet(nf_ct_net(ct))->timeout;
1617
1618 nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
1619 return NF_ACCEPT;
1620 }
1621
1622 /* Returns verdict for packet, or -1 for invalid. */
1623 static int nf_conntrack_handle_packet(struct nf_conn *ct,
1624 struct sk_buff *skb,
1625 unsigned int dataoff,
1626 enum ip_conntrack_info ctinfo,
1627 const struct nf_hook_state *state)
1628 {
1629 switch (nf_ct_protonum(ct)) {
1630 case IPPROTO_TCP:
1631 return nf_conntrack_tcp_packet(ct, skb, dataoff,
1632 ctinfo, state);
1633 case IPPROTO_UDP:
1634 return nf_conntrack_udp_packet(ct, skb, dataoff,
1635 ctinfo, state);
1636 case IPPROTO_ICMP:
1637 return nf_conntrack_icmp_packet(ct, skb, ctinfo, state);
1638 #if IS_ENABLED(CONFIG_IPV6)
1639 case IPPROTO_ICMPV6:
1640 return nf_conntrack_icmpv6_packet(ct, skb, ctinfo, state);
1641 #endif
1642 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
1643 case IPPROTO_UDPLITE:
1644 return nf_conntrack_udplite_packet(ct, skb, dataoff,
1645 ctinfo, state);
1646 #endif
1647 #ifdef CONFIG_NF_CT_PROTO_SCTP
1648 case IPPROTO_SCTP:
1649 return nf_conntrack_sctp_packet(ct, skb, dataoff,
1650 ctinfo, state);
1651 #endif
1652 #ifdef CONFIG_NF_CT_PROTO_DCCP
1653 case IPPROTO_DCCP:
1654 return nf_conntrack_dccp_packet(ct, skb, dataoff,
1655 ctinfo, state);
1656 #endif
1657 #ifdef CONFIG_NF_CT_PROTO_GRE
1658 case IPPROTO_GRE:
1659 return nf_conntrack_gre_packet(ct, skb, dataoff,
1660 ctinfo, state);
1661 #endif
1662 }
1663
1664 return generic_packet(ct, skb, ctinfo);
1665 }
1666
1667 unsigned int
1668 nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
1669 {
1670 enum ip_conntrack_info ctinfo;
1671 struct nf_conn *ct, *tmpl;
1672 u_int8_t protonum;
1673 int dataoff, ret;
1674
1675 tmpl = nf_ct_get(skb, &ctinfo);
1676 if (tmpl || ctinfo == IP_CT_UNTRACKED) {
1677 /* Previously seen (loopback or untracked)? Ignore. */
1678 if ((tmpl && !nf_ct_is_template(tmpl)) ||
1679 ctinfo == IP_CT_UNTRACKED) {
1680 NF_CT_STAT_INC_ATOMIC(state->net, ignore);
1681 return NF_ACCEPT;
1682 }
1683 skb->_nfct = 0;
1684 }
1685
1686 /* rcu_read_lock()ed by nf_hook_thresh */
1687 dataoff = get_l4proto(skb, skb_network_offset(skb), state->pf, &protonum);
1688 if (dataoff <= 0) {
1689 pr_debug("not prepared to track yet or error occurred\n");
1690 NF_CT_STAT_INC_ATOMIC(state->net, error);
1691 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1692 ret = NF_ACCEPT;
1693 goto out;
1694 }
1695
1696 if (protonum == IPPROTO_ICMP || protonum == IPPROTO_ICMPV6) {
1697 ret = nf_conntrack_handle_icmp(tmpl, skb, dataoff,
1698 protonum, state);
1699 if (ret <= 0) {
1700 ret = -ret;
1701 goto out;
1702 }
1703 /* ICMP[v6] protocol trackers may assign one conntrack. */
1704 if (skb->_nfct)
1705 goto out;
1706 }
1707 repeat:
1708 ret = resolve_normal_ct(tmpl, skb, dataoff,
1709 protonum, state);
1710 if (ret < 0) {
1711 /* Too stressed to deal. */
1712 NF_CT_STAT_INC_ATOMIC(state->net, drop);
1713 ret = NF_DROP;
1714 goto out;
1715 }
1716
1717 ct = nf_ct_get(skb, &ctinfo);
1718 if (!ct) {
1719 /* Not valid part of a connection */
1720 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1721 ret = NF_ACCEPT;
1722 goto out;
1723 }
1724
1725 ret = nf_conntrack_handle_packet(ct, skb, dataoff, ctinfo, state);
1726 if (ret <= 0) {
1727 /* Invalid: inverse of the return code tells
1728 * the netfilter core what to do */
1729 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1730 nf_conntrack_put(&ct->ct_general);
1731 skb->_nfct = 0;
1732 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1733 if (ret == -NF_DROP)
1734 NF_CT_STAT_INC_ATOMIC(state->net, drop);
1735 /* Special case: TCP tracker reports an attempt to reopen a
1736 * closed/aborted connection. We have to go back and create a
1737 * fresh conntrack.
1738 */
1739 if (ret == -NF_REPEAT)
1740 goto repeat;
1741 ret = -ret;
1742 goto out;
1743 }
1744
1745 if (ctinfo == IP_CT_ESTABLISHED_REPLY &&
1746 !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1747 nf_conntrack_event_cache(IPCT_REPLY, ct);
1748 out:
1749 if (tmpl)
1750 nf_ct_put(tmpl);
1751
1752 return ret;
1753 }
1754 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1755
1756 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1757 implicitly racy: see __nf_conntrack_confirm */
1758 void nf_conntrack_alter_reply(struct nf_conn *ct,
1759 const struct nf_conntrack_tuple *newreply)
1760 {
1761 struct nf_conn_help *help = nfct_help(ct);
1762
1763 /* Should be unconfirmed, so not in hash table yet */
1764 WARN_ON(nf_ct_is_confirmed(ct));
1765
1766 pr_debug("Altering reply tuple of %p to ", ct);
1767 nf_ct_dump_tuple(newreply);
1768
1769 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1770 if (ct->master || (help && !hlist_empty(&help->expectations)))
1771 return;
1772
1773 rcu_read_lock();
1774 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1775 rcu_read_unlock();
1776 }
1777 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1778
1779 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1780 void __nf_ct_refresh_acct(struct nf_conn *ct,
1781 enum ip_conntrack_info ctinfo,
1782 const struct sk_buff *skb,
1783 u32 extra_jiffies,
1784 bool do_acct)
1785 {
1786 /* Only update if this is not a fixed timeout */
1787 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1788 goto acct;
1789
1790 /* If not in hash table, timer will not be active yet */
1791 if (nf_ct_is_confirmed(ct))
1792 extra_jiffies += nfct_time_stamp;
1793
1794 if (READ_ONCE(ct->timeout) != extra_jiffies)
1795 WRITE_ONCE(ct->timeout, extra_jiffies);
1796 acct:
1797 if (do_acct)
1798 nf_ct_acct_update(ct, ctinfo, skb->len);
1799 }
1800 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1801
1802 bool nf_ct_kill_acct(struct nf_conn *ct,
1803 enum ip_conntrack_info ctinfo,
1804 const struct sk_buff *skb)
1805 {
1806 nf_ct_acct_update(ct, ctinfo, skb->len);
1807
1808 return nf_ct_delete(ct, 0, 0);
1809 }
1810 EXPORT_SYMBOL_GPL(nf_ct_kill_acct);
1811
1812 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1813
1814 #include <linux/netfilter/nfnetlink.h>
1815 #include <linux/netfilter/nfnetlink_conntrack.h>
1816 #include <linux/mutex.h>
1817
1818 /* Generic function for tcp/udp/sctp/dccp and alike. */
1819 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1820 const struct nf_conntrack_tuple *tuple)
1821 {
1822 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1823 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1824 goto nla_put_failure;
1825 return 0;
1826
1827 nla_put_failure:
1828 return -1;
1829 }
1830 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1831
1832 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1833 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1834 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1835 };
1836 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1837
1838 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1839 struct nf_conntrack_tuple *t)
1840 {
1841 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1842 return -EINVAL;
1843
1844 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1845 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1846
1847 return 0;
1848 }
1849 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1850
1851 unsigned int nf_ct_port_nlattr_tuple_size(void)
1852 {
1853 static unsigned int size __read_mostly;
1854
1855 if (!size)
1856 size = nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1857
1858 return size;
1859 }
1860 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1861 #endif
1862
1863 /* Used by ipt_REJECT and ip6t_REJECT. */
1864 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1865 {
1866 struct nf_conn *ct;
1867 enum ip_conntrack_info ctinfo;
1868
1869 /* This ICMP is in reverse direction to the packet which caused it */
1870 ct = nf_ct_get(skb, &ctinfo);
1871 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1872 ctinfo = IP_CT_RELATED_REPLY;
1873 else
1874 ctinfo = IP_CT_RELATED;
1875
1876 /* Attach to new skbuff, and increment count */
1877 nf_ct_set(nskb, ct, ctinfo);
1878 nf_conntrack_get(skb_nfct(nskb));
1879 }
1880
1881 static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
1882 {
1883 struct nf_conntrack_tuple_hash *h;
1884 struct nf_conntrack_tuple tuple;
1885 enum ip_conntrack_info ctinfo;
1886 struct nf_nat_hook *nat_hook;
1887 unsigned int status;
1888 struct nf_conn *ct;
1889 int dataoff;
1890 u16 l3num;
1891 u8 l4num;
1892
1893 ct = nf_ct_get(skb, &ctinfo);
1894 if (!ct || nf_ct_is_confirmed(ct))
1895 return 0;
1896
1897 l3num = nf_ct_l3num(ct);
1898
1899 dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num);
1900 if (dataoff <= 0)
1901 return -1;
1902
1903 if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
1904 l4num, net, &tuple))
1905 return -1;
1906
1907 if (ct->status & IPS_SRC_NAT) {
1908 memcpy(tuple.src.u3.all,
1909 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.all,
1910 sizeof(tuple.src.u3.all));
1911 tuple.src.u.all =
1912 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all;
1913 }
1914
1915 if (ct->status & IPS_DST_NAT) {
1916 memcpy(tuple.dst.u3.all,
1917 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.all,
1918 sizeof(tuple.dst.u3.all));
1919 tuple.dst.u.all =
1920 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all;
1921 }
1922
1923 h = nf_conntrack_find_get(net, nf_ct_zone(ct), &tuple);
1924 if (!h)
1925 return 0;
1926
1927 /* Store status bits of the conntrack that is clashing to re-do NAT
1928 * mangling according to what it has been done already to this packet.
1929 */
1930 status = ct->status;
1931
1932 nf_ct_put(ct);
1933 ct = nf_ct_tuplehash_to_ctrack(h);
1934 nf_ct_set(skb, ct, ctinfo);
1935
1936 nat_hook = rcu_dereference(nf_nat_hook);
1937 if (!nat_hook)
1938 return 0;
1939
1940 if (status & IPS_SRC_NAT &&
1941 nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_SRC,
1942 IP_CT_DIR_ORIGINAL) == NF_DROP)
1943 return -1;
1944
1945 if (status & IPS_DST_NAT &&
1946 nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_DST,
1947 IP_CT_DIR_ORIGINAL) == NF_DROP)
1948 return -1;
1949
1950 return 0;
1951 }
1952
1953 static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
1954 const struct sk_buff *skb)
1955 {
1956 const struct nf_conntrack_tuple *src_tuple;
1957 const struct nf_conntrack_tuple_hash *hash;
1958 struct nf_conntrack_tuple srctuple;
1959 enum ip_conntrack_info ctinfo;
1960 struct nf_conn *ct;
1961
1962 ct = nf_ct_get(skb, &ctinfo);
1963 if (ct) {
1964 src_tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
1965 memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
1966 return true;
1967 }
1968
1969 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
1970 NFPROTO_IPV4, dev_net(skb->dev),
1971 &srctuple))
1972 return false;
1973
1974 hash = nf_conntrack_find_get(dev_net(skb->dev),
1975 &nf_ct_zone_dflt,
1976 &srctuple);
1977 if (!hash)
1978 return false;
1979
1980 ct = nf_ct_tuplehash_to_ctrack(hash);
1981 src_tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
1982 memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
1983 nf_ct_put(ct);
1984
1985 return true;
1986 }
1987
1988 /* Bring out ya dead! */
1989 static struct nf_conn *
1990 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
1991 void *data, unsigned int *bucket)
1992 {
1993 struct nf_conntrack_tuple_hash *h;
1994 struct nf_conn *ct;
1995 struct hlist_nulls_node *n;
1996 spinlock_t *lockp;
1997
1998 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1999 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
2000 local_bh_disable();
2001 nf_conntrack_lock(lockp);
2002 if (*bucket < nf_conntrack_htable_size) {
2003 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
2004 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
2005 continue;
2006 ct = nf_ct_tuplehash_to_ctrack(h);
2007 if (iter(ct, data))
2008 goto found;
2009 }
2010 }
2011 spin_unlock(lockp);
2012 local_bh_enable();
2013 cond_resched();
2014 }
2015
2016 return NULL;
2017 found:
2018 atomic_inc(&ct->ct_general.use);
2019 spin_unlock(lockp);
2020 local_bh_enable();
2021 return ct;
2022 }
2023
2024 static void nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data),
2025 void *data, u32 portid, int report)
2026 {
2027 unsigned int bucket = 0, sequence;
2028 struct nf_conn *ct;
2029
2030 might_sleep();
2031
2032 for (;;) {
2033 sequence = read_seqcount_begin(&nf_conntrack_generation);
2034
2035 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
2036 /* Time to push up daises... */
2037
2038 nf_ct_delete(ct, portid, report);
2039 nf_ct_put(ct);
2040 cond_resched();
2041 }
2042
2043 if (!read_seqcount_retry(&nf_conntrack_generation, sequence))
2044 break;
2045 bucket = 0;
2046 }
2047 }
2048
2049 struct iter_data {
2050 int (*iter)(struct nf_conn *i, void *data);
2051 void *data;
2052 struct net *net;
2053 };
2054
2055 static int iter_net_only(struct nf_conn *i, void *data)
2056 {
2057 struct iter_data *d = data;
2058
2059 if (!net_eq(d->net, nf_ct_net(i)))
2060 return 0;
2061
2062 return d->iter(i, d->data);
2063 }
2064
2065 static void
2066 __nf_ct_unconfirmed_destroy(struct net *net)
2067 {
2068 int cpu;
2069
2070 for_each_possible_cpu(cpu) {
2071 struct nf_conntrack_tuple_hash *h;
2072 struct hlist_nulls_node *n;
2073 struct ct_pcpu *pcpu;
2074
2075 pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
2076
2077 spin_lock_bh(&pcpu->lock);
2078 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
2079 struct nf_conn *ct;
2080
2081 ct = nf_ct_tuplehash_to_ctrack(h);
2082
2083 /* we cannot call iter() on unconfirmed list, the
2084 * owning cpu can reallocate ct->ext at any time.
2085 */
2086 set_bit(IPS_DYING_BIT, &ct->status);
2087 }
2088 spin_unlock_bh(&pcpu->lock);
2089 cond_resched();
2090 }
2091 }
2092
2093 void nf_ct_unconfirmed_destroy(struct net *net)
2094 {
2095 might_sleep();
2096
2097 if (atomic_read(&net->ct.count) > 0) {
2098 __nf_ct_unconfirmed_destroy(net);
2099 nf_queue_nf_hook_drop(net);
2100 synchronize_net();
2101 }
2102 }
2103 EXPORT_SYMBOL_GPL(nf_ct_unconfirmed_destroy);
2104
2105 void nf_ct_iterate_cleanup_net(struct net *net,
2106 int (*iter)(struct nf_conn *i, void *data),
2107 void *data, u32 portid, int report)
2108 {
2109 struct iter_data d;
2110
2111 might_sleep();
2112
2113 if (atomic_read(&net->ct.count) == 0)
2114 return;
2115
2116 d.iter = iter;
2117 d.data = data;
2118 d.net = net;
2119
2120 nf_ct_iterate_cleanup(iter_net_only, &d, portid, report);
2121 }
2122 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup_net);
2123
2124 /**
2125 * nf_ct_iterate_destroy - destroy unconfirmed conntracks and iterate table
2126 * @iter: callback to invoke for each conntrack
2127 * @data: data to pass to @iter
2128 *
2129 * Like nf_ct_iterate_cleanup, but first marks conntracks on the
2130 * unconfirmed list as dying (so they will not be inserted into
2131 * main table).
2132 *
2133 * Can only be called in module exit path.
2134 */
2135 void
2136 nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)
2137 {
2138 struct net *net;
2139
2140 down_read(&net_rwsem);
2141 for_each_net(net) {
2142 if (atomic_read(&net->ct.count) == 0)
2143 continue;
2144 __nf_ct_unconfirmed_destroy(net);
2145 nf_queue_nf_hook_drop(net);
2146 }
2147 up_read(&net_rwsem);
2148
2149 /* Need to wait for netns cleanup worker to finish, if its
2150 * running -- it might have deleted a net namespace from
2151 * the global list, so our __nf_ct_unconfirmed_destroy() might
2152 * not have affected all namespaces.
2153 */
2154 net_ns_barrier();
2155
2156 /* a conntrack could have been unlinked from unconfirmed list
2157 * before we grabbed pcpu lock in __nf_ct_unconfirmed_destroy().
2158 * This makes sure its inserted into conntrack table.
2159 */
2160 synchronize_net();
2161
2162 nf_ct_iterate_cleanup(iter, data, 0, 0);
2163 }
2164 EXPORT_SYMBOL_GPL(nf_ct_iterate_destroy);
2165
2166 static int kill_all(struct nf_conn *i, void *data)
2167 {
2168 return net_eq(nf_ct_net(i), data);
2169 }
2170
2171 void nf_conntrack_cleanup_start(void)
2172 {
2173 conntrack_gc_work.exiting = true;
2174 RCU_INIT_POINTER(ip_ct_attach, NULL);
2175 }
2176
2177 void nf_conntrack_cleanup_end(void)
2178 {
2179 RCU_INIT_POINTER(nf_ct_hook, NULL);
2180 cancel_delayed_work_sync(&conntrack_gc_work.dwork);
2181 kvfree(nf_conntrack_hash);
2182
2183 nf_conntrack_proto_fini();
2184 nf_conntrack_seqadj_fini();
2185 nf_conntrack_labels_fini();
2186 nf_conntrack_helper_fini();
2187 nf_conntrack_timeout_fini();
2188 nf_conntrack_ecache_fini();
2189 nf_conntrack_tstamp_fini();
2190 nf_conntrack_acct_fini();
2191 nf_conntrack_expect_fini();
2192
2193 kmem_cache_destroy(nf_conntrack_cachep);
2194 }
2195
2196 /*
2197 * Mishearing the voices in his head, our hero wonders how he's
2198 * supposed to kill the mall.
2199 */
2200 void nf_conntrack_cleanup_net(struct net *net)
2201 {
2202 LIST_HEAD(single);
2203
2204 list_add(&net->exit_list, &single);
2205 nf_conntrack_cleanup_net_list(&single);
2206 }
2207
2208 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
2209 {
2210 int busy;
2211 struct net *net;
2212
2213 /*
2214 * This makes sure all current packets have passed through
2215 * netfilter framework. Roll on, two-stage module
2216 * delete...
2217 */
2218 synchronize_net();
2219 i_see_dead_people:
2220 busy = 0;
2221 list_for_each_entry(net, net_exit_list, exit_list) {
2222 nf_ct_iterate_cleanup(kill_all, net, 0, 0);
2223 if (atomic_read(&net->ct.count) != 0)
2224 busy = 1;
2225 }
2226 if (busy) {
2227 schedule();
2228 goto i_see_dead_people;
2229 }
2230
2231 list_for_each_entry(net, net_exit_list, exit_list) {
2232 nf_conntrack_proto_pernet_fini(net);
2233 nf_conntrack_ecache_pernet_fini(net);
2234 nf_conntrack_expect_pernet_fini(net);
2235 free_percpu(net->ct.stat);
2236 free_percpu(net->ct.pcpu_lists);
2237 }
2238 }
2239
2240 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
2241 {
2242 struct hlist_nulls_head *hash;
2243 unsigned int nr_slots, i;
2244
2245 if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
2246 return NULL;
2247
2248 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
2249 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
2250
2251 hash = kvmalloc_array(nr_slots, sizeof(struct hlist_nulls_head),
2252 GFP_KERNEL | __GFP_ZERO);
2253
2254 if (hash && nulls)
2255 for (i = 0; i < nr_slots; i++)
2256 INIT_HLIST_NULLS_HEAD(&hash[i], i);
2257
2258 return hash;
2259 }
2260 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
2261
2262 int nf_conntrack_hash_resize(unsigned int hashsize)
2263 {
2264 int i, bucket;
2265 unsigned int old_size;
2266 struct hlist_nulls_head *hash, *old_hash;
2267 struct nf_conntrack_tuple_hash *h;
2268 struct nf_conn *ct;
2269
2270 if (!hashsize)
2271 return -EINVAL;
2272
2273 hash = nf_ct_alloc_hashtable(&hashsize, 1);
2274 if (!hash)
2275 return -ENOMEM;
2276
2277 old_size = nf_conntrack_htable_size;
2278 if (old_size == hashsize) {
2279 kvfree(hash);
2280 return 0;
2281 }
2282
2283 local_bh_disable();
2284 nf_conntrack_all_lock();
2285 write_seqcount_begin(&nf_conntrack_generation);
2286
2287 /* Lookups in the old hash might happen in parallel, which means we
2288 * might get false negatives during connection lookup. New connections
2289 * created because of a false negative won't make it into the hash
2290 * though since that required taking the locks.
2291 */
2292
2293 for (i = 0; i < nf_conntrack_htable_size; i++) {
2294 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
2295 h = hlist_nulls_entry(nf_conntrack_hash[i].first,
2296 struct nf_conntrack_tuple_hash, hnnode);
2297 ct = nf_ct_tuplehash_to_ctrack(h);
2298 hlist_nulls_del_rcu(&h->hnnode);
2299 bucket = __hash_conntrack(nf_ct_net(ct),
2300 &h->tuple, hashsize);
2301 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
2302 }
2303 }
2304 old_size = nf_conntrack_htable_size;
2305 old_hash = nf_conntrack_hash;
2306
2307 nf_conntrack_hash = hash;
2308 nf_conntrack_htable_size = hashsize;
2309
2310 write_seqcount_end(&nf_conntrack_generation);
2311 nf_conntrack_all_unlock();
2312 local_bh_enable();
2313
2314 synchronize_net();
2315 kvfree(old_hash);
2316 return 0;
2317 }
2318
2319 int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp)
2320 {
2321 unsigned int hashsize;
2322 int rc;
2323
2324 if (current->nsproxy->net_ns != &init_net)
2325 return -EOPNOTSUPP;
2326
2327 /* On boot, we can set this without any fancy locking. */
2328 if (!nf_conntrack_hash)
2329 return param_set_uint(val, kp);
2330
2331 rc = kstrtouint(val, 0, &hashsize);
2332 if (rc)
2333 return rc;
2334
2335 return nf_conntrack_hash_resize(hashsize);
2336 }
2337 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
2338
2339 static __always_inline unsigned int total_extension_size(void)
2340 {
2341 /* remember to add new extensions below */
2342 BUILD_BUG_ON(NF_CT_EXT_NUM > 9);
2343
2344 return sizeof(struct nf_ct_ext) +
2345 sizeof(struct nf_conn_help)
2346 #if IS_ENABLED(CONFIG_NF_NAT)
2347 + sizeof(struct nf_conn_nat)
2348 #endif
2349 + sizeof(struct nf_conn_seqadj)
2350 + sizeof(struct nf_conn_acct)
2351 #ifdef CONFIG_NF_CONNTRACK_EVENTS
2352 + sizeof(struct nf_conntrack_ecache)
2353 #endif
2354 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
2355 + sizeof(struct nf_conn_tstamp)
2356 #endif
2357 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
2358 + sizeof(struct nf_conn_timeout)
2359 #endif
2360 #ifdef CONFIG_NF_CONNTRACK_LABELS
2361 + sizeof(struct nf_conn_labels)
2362 #endif
2363 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
2364 + sizeof(struct nf_conn_synproxy)
2365 #endif
2366 ;
2367 };
2368
2369 int nf_conntrack_init_start(void)
2370 {
2371 unsigned long nr_pages = totalram_pages();
2372 int max_factor = 8;
2373 int ret = -ENOMEM;
2374 int i;
2375
2376 /* struct nf_ct_ext uses u8 to store offsets/size */
2377 BUILD_BUG_ON(total_extension_size() > 255u);
2378
2379 seqcount_init(&nf_conntrack_generation);
2380
2381 for (i = 0; i < CONNTRACK_LOCKS; i++)
2382 spin_lock_init(&nf_conntrack_locks[i]);
2383
2384 if (!nf_conntrack_htable_size) {
2385 /* Idea from tcp.c: use 1/16384 of memory.
2386 * On i386: 32MB machine has 512 buckets.
2387 * >= 1GB machines have 16384 buckets.
2388 * >= 4GB machines have 65536 buckets.
2389 */
2390 nf_conntrack_htable_size
2391 = (((nr_pages << PAGE_SHIFT) / 16384)
2392 / sizeof(struct hlist_head));
2393 if (nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
2394 nf_conntrack_htable_size = 65536;
2395 else if (nr_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
2396 nf_conntrack_htable_size = 16384;
2397 if (nf_conntrack_htable_size < 32)
2398 nf_conntrack_htable_size = 32;
2399
2400 /* Use a max. factor of four by default to get the same max as
2401 * with the old struct list_heads. When a table size is given
2402 * we use the old value of 8 to avoid reducing the max.
2403 * entries. */
2404 max_factor = 4;
2405 }
2406
2407 nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
2408 if (!nf_conntrack_hash)
2409 return -ENOMEM;
2410
2411 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
2412
2413 nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
2414 sizeof(struct nf_conn),
2415 NFCT_INFOMASK + 1,
2416 SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
2417 if (!nf_conntrack_cachep)
2418 goto err_cachep;
2419
2420 ret = nf_conntrack_expect_init();
2421 if (ret < 0)
2422 goto err_expect;
2423
2424 ret = nf_conntrack_acct_init();
2425 if (ret < 0)
2426 goto err_acct;
2427
2428 ret = nf_conntrack_tstamp_init();
2429 if (ret < 0)
2430 goto err_tstamp;
2431
2432 ret = nf_conntrack_ecache_init();
2433 if (ret < 0)
2434 goto err_ecache;
2435
2436 ret = nf_conntrack_timeout_init();
2437 if (ret < 0)
2438 goto err_timeout;
2439
2440 ret = nf_conntrack_helper_init();
2441 if (ret < 0)
2442 goto err_helper;
2443
2444 ret = nf_conntrack_labels_init();
2445 if (ret < 0)
2446 goto err_labels;
2447
2448 ret = nf_conntrack_seqadj_init();
2449 if (ret < 0)
2450 goto err_seqadj;
2451
2452 ret = nf_conntrack_proto_init();
2453 if (ret < 0)
2454 goto err_proto;
2455
2456 conntrack_gc_work_init(&conntrack_gc_work);
2457 queue_delayed_work(system_power_efficient_wq, &conntrack_gc_work.dwork, HZ);
2458
2459 return 0;
2460
2461 err_proto:
2462 nf_conntrack_seqadj_fini();
2463 err_seqadj:
2464 nf_conntrack_labels_fini();
2465 err_labels:
2466 nf_conntrack_helper_fini();
2467 err_helper:
2468 nf_conntrack_timeout_fini();
2469 err_timeout:
2470 nf_conntrack_ecache_fini();
2471 err_ecache:
2472 nf_conntrack_tstamp_fini();
2473 err_tstamp:
2474 nf_conntrack_acct_fini();
2475 err_acct:
2476 nf_conntrack_expect_fini();
2477 err_expect:
2478 kmem_cache_destroy(nf_conntrack_cachep);
2479 err_cachep:
2480 kvfree(nf_conntrack_hash);
2481 return ret;
2482 }
2483
2484 static struct nf_ct_hook nf_conntrack_hook = {
2485 .update = nf_conntrack_update,
2486 .destroy = destroy_conntrack,
2487 .get_tuple_skb = nf_conntrack_get_tuple_skb,
2488 };
2489
2490 void nf_conntrack_init_end(void)
2491 {
2492 /* For use by REJECT target */
2493 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
2494 RCU_INIT_POINTER(nf_ct_hook, &nf_conntrack_hook);
2495 }
2496
2497 /*
2498 * We need to use special "null" values, not used in hash table
2499 */
2500 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
2501 #define DYING_NULLS_VAL ((1<<30)+1)
2502 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
2503
2504 int nf_conntrack_init_net(struct net *net)
2505 {
2506 int ret = -ENOMEM;
2507 int cpu;
2508
2509 BUILD_BUG_ON(IP_CT_UNTRACKED == IP_CT_NUMBER);
2510 BUILD_BUG_ON_NOT_POWER_OF_2(CONNTRACK_LOCKS);
2511 atomic_set(&net->ct.count, 0);
2512
2513 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
2514 if (!net->ct.pcpu_lists)
2515 goto err_stat;
2516
2517 for_each_possible_cpu(cpu) {
2518 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
2519
2520 spin_lock_init(&pcpu->lock);
2521 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
2522 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
2523 }
2524
2525 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
2526 if (!net->ct.stat)
2527 goto err_pcpu_lists;
2528
2529 ret = nf_conntrack_expect_pernet_init(net);
2530 if (ret < 0)
2531 goto err_expect;
2532
2533 nf_conntrack_acct_pernet_init(net);
2534 nf_conntrack_tstamp_pernet_init(net);
2535 nf_conntrack_ecache_pernet_init(net);
2536 nf_conntrack_helper_pernet_init(net);
2537 nf_conntrack_proto_pernet_init(net);
2538
2539 return 0;
2540
2541 err_expect:
2542 free_percpu(net->ct.stat);
2543 err_pcpu_lists:
2544 free_percpu(net->ct.pcpu_lists);
2545 err_stat:
2546 return ret;
2547 }
2548
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