1 /* Connection state tracking for netfilter. This is separated from,
2 but required by, the NAT layer; it can also be used by an iptables
5 /* (C) 1999-2001 Paul `Rusty' Russell
6 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
7 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
8 * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/types.h>
16 #include <linux/netfilter.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/skbuff.h>
20 #include <linux/proc_fs.h>
21 #include <linux/vmalloc.h>
22 #include <linux/stddef.h>
23 #include <linux/slab.h>
24 #include <linux/random.h>
25 #include <linux/jhash.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>
34 #include <linux/nsproxy.h>
35 #include <linux/rculist_nulls.h>
37 #include <net/netfilter/nf_conntrack.h>
38 #include <net/netfilter/nf_conntrack_l3proto.h>
39 #include <net/netfilter/nf_conntrack_l4proto.h>
40 #include <net/netfilter/nf_conntrack_expect.h>
41 #include <net/netfilter/nf_conntrack_helper.h>
42 #include <net/netfilter/nf_conntrack_seqadj.h>
43 #include <net/netfilter/nf_conntrack_core.h>
44 #include <net/netfilter/nf_conntrack_extend.h>
45 #include <net/netfilter/nf_conntrack_acct.h>
46 #include <net/netfilter/nf_conntrack_ecache.h>
47 #include <net/netfilter/nf_conntrack_zones.h>
48 #include <net/netfilter/nf_conntrack_timestamp.h>
49 #include <net/netfilter/nf_conntrack_timeout.h>
50 #include <net/netfilter/nf_conntrack_labels.h>
51 #include <net/netfilter/nf_conntrack_synproxy.h>
52 #include <net/netfilter/nf_nat.h>
53 #include <net/netfilter/nf_nat_core.h>
54 #include <net/netfilter/nf_nat_helper.h>
56 #define NF_CONNTRACK_VERSION "0.5.0"
58 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
59 enum nf_nat_manip_type manip,
60 const struct nlattr *attr) __read_mostly;
61 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
63 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
64 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
66 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
67 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
69 static __read_mostly spinlock_t nf_conntrack_locks_all_lock;
70 static __read_mostly bool nf_conntrack_locks_all;
72 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
75 while (unlikely(nf_conntrack_locks_all)) {
77 spin_lock(&nf_conntrack_locks_all_lock);
78 spin_unlock(&nf_conntrack_locks_all_lock);
82 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
84 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
86 h1 %= CONNTRACK_LOCKS;
87 h2 %= CONNTRACK_LOCKS;
88 spin_unlock(&nf_conntrack_locks[h1]);
90 spin_unlock(&nf_conntrack_locks[h2]);
93 /* return true if we need to recompute hashes (in case hash table was resized) */
94 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
95 unsigned int h2, unsigned int sequence)
97 h1 %= CONNTRACK_LOCKS;
98 h2 %= CONNTRACK_LOCKS;
100 nf_conntrack_lock(&nf_conntrack_locks[h1]);
102 spin_lock_nested(&nf_conntrack_locks[h2],
103 SINGLE_DEPTH_NESTING);
105 nf_conntrack_lock(&nf_conntrack_locks[h2]);
106 spin_lock_nested(&nf_conntrack_locks[h1],
107 SINGLE_DEPTH_NESTING);
109 if (read_seqcount_retry(&net->ct.generation, sequence)) {
110 nf_conntrack_double_unlock(h1, h2);
116 static void nf_conntrack_all_lock(void)
120 spin_lock(&nf_conntrack_locks_all_lock);
121 nf_conntrack_locks_all = true;
123 for (i = 0; i < CONNTRACK_LOCKS; i++) {
124 spin_lock(&nf_conntrack_locks[i]);
125 spin_unlock(&nf_conntrack_locks[i]);
129 static void nf_conntrack_all_unlock(void)
131 nf_conntrack_locks_all = false;
132 spin_unlock(&nf_conntrack_locks_all_lock);
135 unsigned int nf_conntrack_htable_size __read_mostly;
136 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
138 unsigned int nf_conntrack_max __read_mostly;
139 EXPORT_SYMBOL_GPL(nf_conntrack_max);
141 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
142 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
144 unsigned int nf_conntrack_hash_rnd __read_mostly;
145 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
147 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple)
151 /* The direction must be ignored, so we hash everything up to the
152 * destination ports (which is a multiple of 4) and treat the last
153 * three bytes manually.
155 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
156 return jhash2((u32 *)tuple, n, nf_conntrack_hash_rnd ^
157 (((__force __u16)tuple->dst.u.all << 16) |
158 tuple->dst.protonum));
161 static u32 __hash_bucket(u32 hash, unsigned int size)
163 return reciprocal_scale(hash, size);
166 static u32 hash_bucket(u32 hash, const struct net *net)
168 return __hash_bucket(hash, net->ct.htable_size);
171 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
174 return __hash_bucket(hash_conntrack_raw(tuple), size);
177 static inline u_int32_t hash_conntrack(const struct net *net,
178 const struct nf_conntrack_tuple *tuple)
180 return __hash_conntrack(tuple, net->ct.htable_size);
184 nf_ct_get_tuple(const struct sk_buff *skb,
186 unsigned int dataoff,
190 struct nf_conntrack_tuple *tuple,
191 const struct nf_conntrack_l3proto *l3proto,
192 const struct nf_conntrack_l4proto *l4proto)
194 memset(tuple, 0, sizeof(*tuple));
196 tuple->src.l3num = l3num;
197 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
200 tuple->dst.protonum = protonum;
201 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
203 return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
205 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
207 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
209 struct net *net, struct nf_conntrack_tuple *tuple)
211 struct nf_conntrack_l3proto *l3proto;
212 struct nf_conntrack_l4proto *l4proto;
213 unsigned int protoff;
219 l3proto = __nf_ct_l3proto_find(l3num);
220 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
221 if (ret != NF_ACCEPT) {
226 l4proto = __nf_ct_l4proto_find(l3num, protonum);
228 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
234 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
237 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
238 const struct nf_conntrack_tuple *orig,
239 const struct nf_conntrack_l3proto *l3proto,
240 const struct nf_conntrack_l4proto *l4proto)
242 memset(inverse, 0, sizeof(*inverse));
244 inverse->src.l3num = orig->src.l3num;
245 if (l3proto->invert_tuple(inverse, orig) == 0)
248 inverse->dst.dir = !orig->dst.dir;
250 inverse->dst.protonum = orig->dst.protonum;
251 return l4proto->invert_tuple(inverse, orig);
253 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
256 clean_from_lists(struct nf_conn *ct)
258 pr_debug("clean_from_lists(%p)\n", ct);
259 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
260 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
262 /* Destroy all pending expectations */
263 nf_ct_remove_expectations(ct);
266 /* must be called with local_bh_disable */
267 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
269 struct ct_pcpu *pcpu;
271 /* add this conntrack to the (per cpu) dying list */
272 ct->cpu = smp_processor_id();
273 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
275 spin_lock(&pcpu->lock);
276 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
278 spin_unlock(&pcpu->lock);
281 /* must be called with local_bh_disable */
282 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
284 struct ct_pcpu *pcpu;
286 /* add this conntrack to the (per cpu) unconfirmed list */
287 ct->cpu = smp_processor_id();
288 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
290 spin_lock(&pcpu->lock);
291 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
293 spin_unlock(&pcpu->lock);
296 /* must be called with local_bh_disable */
297 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
299 struct ct_pcpu *pcpu;
301 /* We overload first tuple to link into unconfirmed or dying list.*/
302 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
304 spin_lock(&pcpu->lock);
305 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
306 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
307 spin_unlock(&pcpu->lock);
310 /* Released via destroy_conntrack() */
311 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
312 const struct nf_conntrack_zone *zone,
315 struct nf_conn *tmpl;
317 tmpl = kzalloc(sizeof(*tmpl), flags);
321 tmpl->status = IPS_TEMPLATE;
322 write_pnet(&tmpl->ct_net, net);
324 if (nf_ct_zone_add(tmpl, flags, zone) < 0)
327 atomic_set(&tmpl->ct_general.use, 0);
334 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
336 void nf_ct_tmpl_free(struct nf_conn *tmpl)
338 nf_ct_ext_destroy(tmpl);
339 nf_ct_ext_free(tmpl);
342 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
345 destroy_conntrack(struct nf_conntrack *nfct)
347 struct nf_conn *ct = (struct nf_conn *)nfct;
348 struct net *net = nf_ct_net(ct);
349 struct nf_conntrack_l4proto *l4proto;
351 pr_debug("destroy_conntrack(%p)\n", ct);
352 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
353 NF_CT_ASSERT(!timer_pending(&ct->timeout));
355 if (unlikely(nf_ct_is_template(ct))) {
360 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
361 if (l4proto && l4proto->destroy)
362 l4proto->destroy(ct);
367 /* Expectations will have been removed in clean_from_lists,
368 * except TFTP can create an expectation on the first packet,
369 * before connection is in the list, so we need to clean here,
372 nf_ct_remove_expectations(ct);
374 nf_ct_del_from_dying_or_unconfirmed_list(ct);
376 NF_CT_STAT_INC(net, delete);
380 nf_ct_put(ct->master);
382 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
383 nf_conntrack_free(ct);
386 static void nf_ct_delete_from_lists(struct nf_conn *ct)
388 struct net *net = nf_ct_net(ct);
389 unsigned int hash, reply_hash;
390 unsigned int sequence;
392 nf_ct_helper_destroy(ct);
396 sequence = read_seqcount_begin(&net->ct.generation);
397 hash = hash_conntrack(net,
398 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
399 reply_hash = hash_conntrack(net,
400 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
401 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
403 clean_from_lists(ct);
404 nf_conntrack_double_unlock(hash, reply_hash);
406 nf_ct_add_to_dying_list(ct);
408 NF_CT_STAT_INC(net, delete_list);
412 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
414 struct nf_conn_tstamp *tstamp;
416 tstamp = nf_conn_tstamp_find(ct);
417 if (tstamp && tstamp->stop == 0)
418 tstamp->stop = ktime_get_real_ns();
420 if (nf_ct_is_dying(ct))
423 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
424 portid, report) < 0) {
425 /* destroy event was not delivered */
426 nf_ct_delete_from_lists(ct);
427 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
431 nf_conntrack_ecache_work(nf_ct_net(ct));
432 set_bit(IPS_DYING_BIT, &ct->status);
434 nf_ct_delete_from_lists(ct);
438 EXPORT_SYMBOL_GPL(nf_ct_delete);
440 static void death_by_timeout(unsigned long ul_conntrack)
442 nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
446 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
447 const struct nf_conntrack_tuple *tuple,
448 const struct nf_conntrack_zone *zone)
450 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
452 /* A conntrack can be recreated with the equal tuple,
453 * so we need to check that the conntrack is confirmed
455 return nf_ct_tuple_equal(tuple, &h->tuple) &&
456 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
457 nf_ct_is_confirmed(ct);
462 * - Caller must take a reference on returned object
463 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
465 static struct nf_conntrack_tuple_hash *
466 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
467 const struct nf_conntrack_tuple *tuple, u32 hash)
469 struct nf_conntrack_tuple_hash *h;
470 struct hlist_nulls_node *n;
471 unsigned int bucket = hash_bucket(hash, net);
473 /* Disable BHs the entire time since we normally need to disable them
474 * at least once for the stats anyway.
478 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
479 if (nf_ct_key_equal(h, tuple, zone)) {
480 NF_CT_STAT_INC(net, found);
484 NF_CT_STAT_INC(net, searched);
487 * if the nulls value we got at the end of this lookup is
488 * not the expected one, we must restart lookup.
489 * We probably met an item that was moved to another chain.
491 if (get_nulls_value(n) != bucket) {
492 NF_CT_STAT_INC(net, search_restart);
500 /* Find a connection corresponding to a tuple. */
501 static struct nf_conntrack_tuple_hash *
502 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
503 const struct nf_conntrack_tuple *tuple, u32 hash)
505 struct nf_conntrack_tuple_hash *h;
510 h = ____nf_conntrack_find(net, zone, tuple, hash);
512 ct = nf_ct_tuplehash_to_ctrack(h);
513 if (unlikely(nf_ct_is_dying(ct) ||
514 !atomic_inc_not_zero(&ct->ct_general.use)))
517 if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
528 struct nf_conntrack_tuple_hash *
529 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
530 const struct nf_conntrack_tuple *tuple)
532 return __nf_conntrack_find_get(net, zone, tuple,
533 hash_conntrack_raw(tuple));
535 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
537 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
539 unsigned int reply_hash)
541 struct net *net = nf_ct_net(ct);
543 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
544 &net->ct.hash[hash]);
545 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
546 &net->ct.hash[reply_hash]);
550 nf_conntrack_hash_check_insert(struct nf_conn *ct)
552 const struct nf_conntrack_zone *zone;
553 struct net *net = nf_ct_net(ct);
554 unsigned int hash, reply_hash;
555 struct nf_conntrack_tuple_hash *h;
556 struct hlist_nulls_node *n;
557 unsigned int sequence;
559 zone = nf_ct_zone(ct);
563 sequence = read_seqcount_begin(&net->ct.generation);
564 hash = hash_conntrack(net,
565 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
566 reply_hash = hash_conntrack(net,
567 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
568 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
570 /* See if there's one in the list already, including reverse */
571 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
572 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
574 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
577 hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
578 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
580 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
584 add_timer(&ct->timeout);
586 /* The caller holds a reference to this object */
587 atomic_set(&ct->ct_general.use, 2);
588 __nf_conntrack_hash_insert(ct, hash, reply_hash);
589 nf_conntrack_double_unlock(hash, reply_hash);
590 NF_CT_STAT_INC(net, insert);
595 nf_conntrack_double_unlock(hash, reply_hash);
596 NF_CT_STAT_INC(net, insert_failed);
600 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
602 /* Confirm a connection given skb; places it in hash table */
604 __nf_conntrack_confirm(struct sk_buff *skb)
606 const struct nf_conntrack_zone *zone;
607 unsigned int hash, reply_hash;
608 struct nf_conntrack_tuple_hash *h;
610 struct nf_conn_help *help;
611 struct nf_conn_tstamp *tstamp;
612 struct hlist_nulls_node *n;
613 enum ip_conntrack_info ctinfo;
615 unsigned int sequence;
617 ct = nf_ct_get(skb, &ctinfo);
620 /* ipt_REJECT uses nf_conntrack_attach to attach related
621 ICMP/TCP RST packets in other direction. Actual packet
622 which created connection will be IP_CT_NEW or for an
623 expected connection, IP_CT_RELATED. */
624 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
627 zone = nf_ct_zone(ct);
631 sequence = read_seqcount_begin(&net->ct.generation);
632 /* reuse the hash saved before */
633 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
634 hash = hash_bucket(hash, net);
635 reply_hash = hash_conntrack(net,
636 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
638 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
640 /* We're not in hash table, and we refuse to set up related
641 * connections for unconfirmed conns. But packet copies and
642 * REJECT will give spurious warnings here.
644 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
646 /* No external references means no one else could have
649 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
650 pr_debug("Confirming conntrack %p\n", ct);
651 /* We have to check the DYING flag after unlink to prevent
652 * a race against nf_ct_get_next_corpse() possibly called from
653 * user context, else we insert an already 'dead' hash, blocking
654 * further use of that particular connection -JM.
656 nf_ct_del_from_dying_or_unconfirmed_list(ct);
658 if (unlikely(nf_ct_is_dying(ct)))
661 /* See if there's one in the list already, including reverse:
662 NAT could have grabbed it without realizing, since we're
663 not in the hash. If there is, we lost race. */
664 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
665 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
667 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
670 hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
671 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
673 nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
677 /* Timer relative to confirmation time, not original
678 setting time, otherwise we'd get timer wrap in
679 weird delay cases. */
680 ct->timeout.expires += jiffies;
681 add_timer(&ct->timeout);
682 atomic_inc(&ct->ct_general.use);
683 ct->status |= IPS_CONFIRMED;
685 /* set conntrack timestamp, if enabled. */
686 tstamp = nf_conn_tstamp_find(ct);
688 if (skb->tstamp.tv64 == 0)
689 __net_timestamp(skb);
691 tstamp->start = ktime_to_ns(skb->tstamp);
693 /* Since the lookup is lockless, hash insertion must be done after
694 * starting the timer and setting the CONFIRMED bit. The RCU barriers
695 * guarantee that no other CPU can find the conntrack before the above
696 * stores are visible.
698 __nf_conntrack_hash_insert(ct, hash, reply_hash);
699 nf_conntrack_double_unlock(hash, reply_hash);
700 NF_CT_STAT_INC(net, insert);
703 help = nfct_help(ct);
704 if (help && help->helper)
705 nf_conntrack_event_cache(IPCT_HELPER, ct);
707 nf_conntrack_event_cache(master_ct(ct) ?
708 IPCT_RELATED : IPCT_NEW, ct);
712 nf_ct_add_to_dying_list(ct);
713 nf_conntrack_double_unlock(hash, reply_hash);
714 NF_CT_STAT_INC(net, insert_failed);
718 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
720 /* Returns true if a connection correspondings to the tuple (required
723 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
724 const struct nf_conn *ignored_conntrack)
726 struct net *net = nf_ct_net(ignored_conntrack);
727 const struct nf_conntrack_zone *zone;
728 struct nf_conntrack_tuple_hash *h;
729 struct hlist_nulls_node *n;
733 zone = nf_ct_zone(ignored_conntrack);
734 hash = hash_conntrack(net, tuple);
736 /* Disable BHs the entire time since we need to disable them at
737 * least once for the stats anyway.
740 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
741 ct = nf_ct_tuplehash_to_ctrack(h);
742 if (ct != ignored_conntrack &&
743 nf_ct_tuple_equal(tuple, &h->tuple) &&
744 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
745 NF_CT_STAT_INC(net, found);
746 rcu_read_unlock_bh();
749 NF_CT_STAT_INC(net, searched);
751 rcu_read_unlock_bh();
755 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
757 #define NF_CT_EVICTION_RANGE 8
759 /* There's a small race here where we may free a just-assured
760 connection. Too bad: we're in trouble anyway. */
761 static noinline int early_drop(struct net *net, unsigned int _hash)
763 /* Use oldest entry, which is roughly LRU */
764 struct nf_conntrack_tuple_hash *h;
765 struct nf_conn *ct = NULL, *tmp;
766 struct hlist_nulls_node *n;
767 unsigned int i = 0, cnt = 0;
769 unsigned int hash, sequence;
774 sequence = read_seqcount_begin(&net->ct.generation);
775 hash = hash_bucket(_hash, net);
776 for (; i < net->ct.htable_size; i++) {
777 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
778 nf_conntrack_lock(lockp);
779 if (read_seqcount_retry(&net->ct.generation, sequence)) {
783 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
785 tmp = nf_ct_tuplehash_to_ctrack(h);
786 if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
787 !nf_ct_is_dying(tmp) &&
788 atomic_inc_not_zero(&tmp->ct_general.use)) {
795 hash = (hash + 1) % net->ct.htable_size;
798 if (ct || cnt >= NF_CT_EVICTION_RANGE)
807 if (del_timer(&ct->timeout)) {
808 if (nf_ct_delete(ct, 0, 0)) {
810 NF_CT_STAT_INC_ATOMIC(net, early_drop);
817 void init_nf_conntrack_hash_rnd(void)
822 * Why not initialize nf_conntrack_rnd in a "init()" function ?
823 * Because there isn't enough entropy when system initializing,
824 * and we initialize it as late as possible.
827 get_random_bytes(&rand, sizeof(rand));
829 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
832 static struct nf_conn *
833 __nf_conntrack_alloc(struct net *net,
834 const struct nf_conntrack_zone *zone,
835 const struct nf_conntrack_tuple *orig,
836 const struct nf_conntrack_tuple *repl,
841 if (unlikely(!nf_conntrack_hash_rnd)) {
842 init_nf_conntrack_hash_rnd();
843 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
844 hash = hash_conntrack_raw(orig);
847 /* We don't want any race condition at early drop stage */
848 atomic_inc(&net->ct.count);
850 if (nf_conntrack_max &&
851 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
852 if (!early_drop(net, hash)) {
853 atomic_dec(&net->ct.count);
854 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
855 return ERR_PTR(-ENOMEM);
860 * Do not use kmem_cache_zalloc(), as this cache uses
861 * SLAB_DESTROY_BY_RCU.
863 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
867 spin_lock_init(&ct->lock);
868 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
869 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
870 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
871 /* save hash for reusing when confirming */
872 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
874 /* Don't set timer yet: wait for confirmation */
875 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
876 write_pnet(&ct->ct_net, net);
877 memset(&ct->__nfct_init_offset[0], 0,
878 offsetof(struct nf_conn, proto) -
879 offsetof(struct nf_conn, __nfct_init_offset[0]));
881 if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
884 /* Because we use RCU lookups, we set ct_general.use to zero before
885 * this is inserted in any list.
887 atomic_set(&ct->ct_general.use, 0);
890 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
892 atomic_dec(&net->ct.count);
893 return ERR_PTR(-ENOMEM);
896 struct nf_conn *nf_conntrack_alloc(struct net *net,
897 const struct nf_conntrack_zone *zone,
898 const struct nf_conntrack_tuple *orig,
899 const struct nf_conntrack_tuple *repl,
902 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
904 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
906 void nf_conntrack_free(struct nf_conn *ct)
908 struct net *net = nf_ct_net(ct);
910 /* A freed object has refcnt == 0, that's
911 * the golden rule for SLAB_DESTROY_BY_RCU
913 NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
915 nf_ct_ext_destroy(ct);
917 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
918 smp_mb__before_atomic();
919 atomic_dec(&net->ct.count);
921 EXPORT_SYMBOL_GPL(nf_conntrack_free);
924 /* Allocate a new conntrack: we return -ENOMEM if classification
925 failed due to stress. Otherwise it really is unclassifiable. */
926 static struct nf_conntrack_tuple_hash *
927 init_conntrack(struct net *net, struct nf_conn *tmpl,
928 const struct nf_conntrack_tuple *tuple,
929 struct nf_conntrack_l3proto *l3proto,
930 struct nf_conntrack_l4proto *l4proto,
932 unsigned int dataoff, u32 hash)
935 struct nf_conn_help *help;
936 struct nf_conntrack_tuple repl_tuple;
937 struct nf_conntrack_ecache *ecache;
938 struct nf_conntrack_expect *exp = NULL;
939 const struct nf_conntrack_zone *zone;
940 struct nf_conn_timeout *timeout_ext;
941 struct nf_conntrack_zone tmp;
942 unsigned int *timeouts;
944 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
945 pr_debug("Can't invert tuple.\n");
949 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
950 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
953 return (struct nf_conntrack_tuple_hash *)ct;
955 if (tmpl && nfct_synproxy(tmpl)) {
956 nfct_seqadj_ext_add(ct);
957 nfct_synproxy_ext_add(ct);
960 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
962 timeouts = nf_ct_timeout_data(timeout_ext);
963 if (unlikely(!timeouts))
964 timeouts = l4proto->get_timeouts(net);
966 timeouts = l4proto->get_timeouts(net);
969 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
970 nf_conntrack_free(ct);
971 pr_debug("init conntrack: can't track with proto module\n");
976 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
979 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
980 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
981 nf_ct_labels_ext_add(ct);
983 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
984 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
985 ecache ? ecache->expmask : 0,
989 if (net->ct.expect_count) {
990 spin_lock(&nf_conntrack_expect_lock);
991 exp = nf_ct_find_expectation(net, zone, tuple);
993 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
995 /* Welcome, Mr. Bond. We've been expecting you... */
996 __set_bit(IPS_EXPECTED_BIT, &ct->status);
997 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
998 ct->master = exp->master;
1000 help = nf_ct_helper_ext_add(ct, exp->helper,
1003 rcu_assign_pointer(help->helper, exp->helper);
1006 #ifdef CONFIG_NF_CONNTRACK_MARK
1007 ct->mark = exp->master->mark;
1009 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1010 ct->secmark = exp->master->secmark;
1012 NF_CT_STAT_INC(net, expect_new);
1014 spin_unlock(&nf_conntrack_expect_lock);
1017 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1018 NF_CT_STAT_INC(net, new);
1021 /* Now it is inserted into the unconfirmed list, bump refcount */
1022 nf_conntrack_get(&ct->ct_general);
1023 nf_ct_add_to_unconfirmed_list(ct);
1029 exp->expectfn(ct, exp);
1030 nf_ct_expect_put(exp);
1033 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1036 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1037 static inline struct nf_conn *
1038 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1039 struct sk_buff *skb,
1040 unsigned int dataoff,
1043 struct nf_conntrack_l3proto *l3proto,
1044 struct nf_conntrack_l4proto *l4proto,
1046 enum ip_conntrack_info *ctinfo)
1048 const struct nf_conntrack_zone *zone;
1049 struct nf_conntrack_tuple tuple;
1050 struct nf_conntrack_tuple_hash *h;
1051 struct nf_conntrack_zone tmp;
1055 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1056 dataoff, l3num, protonum, net, &tuple, l3proto,
1058 pr_debug("resolve_normal_ct: Can't get tuple\n");
1062 /* look for tuple match */
1063 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1064 hash = hash_conntrack_raw(&tuple);
1065 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1067 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1068 skb, dataoff, hash);
1074 ct = nf_ct_tuplehash_to_ctrack(h);
1076 /* It exists; we have (non-exclusive) reference. */
1077 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1078 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1079 /* Please set reply bit if this packet OK */
1082 /* Once we've had two way comms, always ESTABLISHED. */
1083 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1084 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1085 *ctinfo = IP_CT_ESTABLISHED;
1086 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1087 pr_debug("nf_conntrack_in: related packet for %p\n",
1089 *ctinfo = IP_CT_RELATED;
1091 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1092 *ctinfo = IP_CT_NEW;
1096 skb->nfct = &ct->ct_general;
1097 skb->nfctinfo = *ctinfo;
1102 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1103 struct sk_buff *skb)
1105 struct nf_conn *ct, *tmpl = NULL;
1106 enum ip_conntrack_info ctinfo;
1107 struct nf_conntrack_l3proto *l3proto;
1108 struct nf_conntrack_l4proto *l4proto;
1109 unsigned int *timeouts;
1110 unsigned int dataoff;
1116 /* Previously seen (loopback or untracked)? Ignore. */
1117 tmpl = (struct nf_conn *)skb->nfct;
1118 if (!nf_ct_is_template(tmpl)) {
1119 NF_CT_STAT_INC_ATOMIC(net, ignore);
1125 /* rcu_read_lock()ed by nf_hook_slow */
1126 l3proto = __nf_ct_l3proto_find(pf);
1127 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1128 &dataoff, &protonum);
1130 pr_debug("not prepared to track yet or error occurred\n");
1131 NF_CT_STAT_INC_ATOMIC(net, error);
1132 NF_CT_STAT_INC_ATOMIC(net, invalid);
1137 l4proto = __nf_ct_l4proto_find(pf, protonum);
1139 /* It may be an special packet, error, unclean...
1140 * inverse of the return code tells to the netfilter
1141 * core what to do with the packet. */
1142 if (l4proto->error != NULL) {
1143 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1146 NF_CT_STAT_INC_ATOMIC(net, error);
1147 NF_CT_STAT_INC_ATOMIC(net, invalid);
1151 /* ICMP[v6] protocol trackers may assign one conntrack. */
1156 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1157 l3proto, l4proto, &set_reply, &ctinfo);
1159 /* Not valid part of a connection */
1160 NF_CT_STAT_INC_ATOMIC(net, invalid);
1166 /* Too stressed to deal. */
1167 NF_CT_STAT_INC_ATOMIC(net, drop);
1172 NF_CT_ASSERT(skb->nfct);
1174 /* Decide what timeout policy we want to apply to this flow. */
1175 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1177 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1179 /* Invalid: inverse of the return code tells
1180 * the netfilter core what to do */
1181 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1182 nf_conntrack_put(skb->nfct);
1184 NF_CT_STAT_INC_ATOMIC(net, invalid);
1185 if (ret == -NF_DROP)
1186 NF_CT_STAT_INC_ATOMIC(net, drop);
1191 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1192 nf_conntrack_event_cache(IPCT_REPLY, ct);
1195 /* Special case: we have to repeat this hook, assign the
1196 * template again to this packet. We assume that this packet
1197 * has no conntrack assigned. This is used by nf_ct_tcp. */
1198 if (ret == NF_REPEAT)
1199 skb->nfct = (struct nf_conntrack *)tmpl;
1206 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1208 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1209 const struct nf_conntrack_tuple *orig)
1214 ret = nf_ct_invert_tuple(inverse, orig,
1215 __nf_ct_l3proto_find(orig->src.l3num),
1216 __nf_ct_l4proto_find(orig->src.l3num,
1217 orig->dst.protonum));
1221 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1223 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1224 implicitly racy: see __nf_conntrack_confirm */
1225 void nf_conntrack_alter_reply(struct nf_conn *ct,
1226 const struct nf_conntrack_tuple *newreply)
1228 struct nf_conn_help *help = nfct_help(ct);
1230 /* Should be unconfirmed, so not in hash table yet */
1231 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1233 pr_debug("Altering reply tuple of %p to ", ct);
1234 nf_ct_dump_tuple(newreply);
1236 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1237 if (ct->master || (help && !hlist_empty(&help->expectations)))
1241 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1244 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1246 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1247 void __nf_ct_refresh_acct(struct nf_conn *ct,
1248 enum ip_conntrack_info ctinfo,
1249 const struct sk_buff *skb,
1250 unsigned long extra_jiffies,
1253 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1256 /* Only update if this is not a fixed timeout */
1257 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1260 /* If not in hash table, timer will not be active yet */
1261 if (!nf_ct_is_confirmed(ct)) {
1262 ct->timeout.expires = extra_jiffies;
1264 unsigned long newtime = jiffies + extra_jiffies;
1266 /* Only update the timeout if the new timeout is at least
1267 HZ jiffies from the old timeout. Need del_timer for race
1268 avoidance (may already be dying). */
1269 if (newtime - ct->timeout.expires >= HZ)
1270 mod_timer_pending(&ct->timeout, newtime);
1275 struct nf_conn_acct *acct;
1277 acct = nf_conn_acct_find(ct);
1279 struct nf_conn_counter *counter = acct->counter;
1281 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1282 atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1286 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1288 bool __nf_ct_kill_acct(struct nf_conn *ct,
1289 enum ip_conntrack_info ctinfo,
1290 const struct sk_buff *skb,
1294 struct nf_conn_acct *acct;
1296 acct = nf_conn_acct_find(ct);
1298 struct nf_conn_counter *counter = acct->counter;
1300 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1301 atomic64_add(skb->len - skb_network_offset(skb),
1302 &counter[CTINFO2DIR(ctinfo)].bytes);
1306 if (del_timer(&ct->timeout)) {
1307 ct->timeout.function((unsigned long)ct);
1312 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1314 #ifdef CONFIG_NF_CONNTRACK_ZONES
1315 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1316 .len = sizeof(struct nf_conntrack_zone),
1317 .align = __alignof__(struct nf_conntrack_zone),
1318 .id = NF_CT_EXT_ZONE,
1322 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1324 #include <linux/netfilter/nfnetlink.h>
1325 #include <linux/netfilter/nfnetlink_conntrack.h>
1326 #include <linux/mutex.h>
1328 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1329 * in ip_conntrack_core, since we don't want the protocols to autoload
1330 * or depend on ctnetlink */
1331 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1332 const struct nf_conntrack_tuple *tuple)
1334 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1335 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1336 goto nla_put_failure;
1342 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1344 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1345 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1346 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1348 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1350 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1351 struct nf_conntrack_tuple *t)
1353 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1356 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1357 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1361 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1363 int nf_ct_port_nlattr_tuple_size(void)
1365 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1367 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1370 /* Used by ipt_REJECT and ip6t_REJECT. */
1371 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1374 enum ip_conntrack_info ctinfo;
1376 /* This ICMP is in reverse direction to the packet which caused it */
1377 ct = nf_ct_get(skb, &ctinfo);
1378 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1379 ctinfo = IP_CT_RELATED_REPLY;
1381 ctinfo = IP_CT_RELATED;
1383 /* Attach to new skbuff, and increment count */
1384 nskb->nfct = &ct->ct_general;
1385 nskb->nfctinfo = ctinfo;
1386 nf_conntrack_get(nskb->nfct);
1389 /* Bring out ya dead! */
1390 static struct nf_conn *
1391 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1392 void *data, unsigned int *bucket)
1394 struct nf_conntrack_tuple_hash *h;
1396 struct hlist_nulls_node *n;
1400 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1401 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1403 nf_conntrack_lock(lockp);
1404 if (*bucket < net->ct.htable_size) {
1405 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1406 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1408 ct = nf_ct_tuplehash_to_ctrack(h);
1417 for_each_possible_cpu(cpu) {
1418 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1420 spin_lock_bh(&pcpu->lock);
1421 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1422 ct = nf_ct_tuplehash_to_ctrack(h);
1424 set_bit(IPS_DYING_BIT, &ct->status);
1426 spin_unlock_bh(&pcpu->lock);
1430 atomic_inc(&ct->ct_general.use);
1436 void nf_ct_iterate_cleanup(struct net *net,
1437 int (*iter)(struct nf_conn *i, void *data),
1438 void *data, u32 portid, int report)
1441 unsigned int bucket = 0;
1443 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1444 /* Time to push up daises... */
1445 if (del_timer(&ct->timeout))
1446 nf_ct_delete(ct, portid, report);
1448 /* ... else the timer will get him soon. */
1453 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1455 static int kill_all(struct nf_conn *i, void *data)
1460 void nf_ct_free_hashtable(void *hash, unsigned int size)
1462 if (is_vmalloc_addr(hash))
1465 free_pages((unsigned long)hash,
1466 get_order(sizeof(struct hlist_head) * size));
1468 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1470 static int untrack_refs(void)
1474 for_each_possible_cpu(cpu) {
1475 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1477 cnt += atomic_read(&ct->ct_general.use) - 1;
1482 void nf_conntrack_cleanup_start(void)
1484 RCU_INIT_POINTER(ip_ct_attach, NULL);
1487 void nf_conntrack_cleanup_end(void)
1489 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1490 while (untrack_refs() > 0)
1493 #ifdef CONFIG_NF_CONNTRACK_ZONES
1494 nf_ct_extend_unregister(&nf_ct_zone_extend);
1496 nf_conntrack_proto_fini();
1497 nf_conntrack_seqadj_fini();
1498 nf_conntrack_labels_fini();
1499 nf_conntrack_helper_fini();
1500 nf_conntrack_timeout_fini();
1501 nf_conntrack_ecache_fini();
1502 nf_conntrack_tstamp_fini();
1503 nf_conntrack_acct_fini();
1504 nf_conntrack_expect_fini();
1508 * Mishearing the voices in his head, our hero wonders how he's
1509 * supposed to kill the mall.
1511 void nf_conntrack_cleanup_net(struct net *net)
1515 list_add(&net->exit_list, &single);
1516 nf_conntrack_cleanup_net_list(&single);
1519 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1525 * This makes sure all current packets have passed through
1526 * netfilter framework. Roll on, two-stage module
1532 list_for_each_entry(net, net_exit_list, exit_list) {
1533 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1534 if (atomic_read(&net->ct.count) != 0)
1539 goto i_see_dead_people;
1542 list_for_each_entry(net, net_exit_list, exit_list) {
1543 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1544 nf_conntrack_proto_pernet_fini(net);
1545 nf_conntrack_helper_pernet_fini(net);
1546 nf_conntrack_ecache_pernet_fini(net);
1547 nf_conntrack_tstamp_pernet_fini(net);
1548 nf_conntrack_acct_pernet_fini(net);
1549 nf_conntrack_expect_pernet_fini(net);
1550 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1551 kfree(net->ct.slabname);
1552 free_percpu(net->ct.stat);
1553 free_percpu(net->ct.pcpu_lists);
1557 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1559 struct hlist_nulls_head *hash;
1560 unsigned int nr_slots, i;
1563 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1564 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1565 sz = nr_slots * sizeof(struct hlist_nulls_head);
1566 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1572 for (i = 0; i < nr_slots; i++)
1573 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1577 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1579 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1582 unsigned int hashsize, old_size;
1583 struct hlist_nulls_head *hash, *old_hash;
1584 struct nf_conntrack_tuple_hash *h;
1587 if (current->nsproxy->net_ns != &init_net)
1590 /* On boot, we can set this without any fancy locking. */
1591 if (!nf_conntrack_htable_size)
1592 return param_set_uint(val, kp);
1594 rc = kstrtouint(val, 0, &hashsize);
1600 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1605 nf_conntrack_all_lock();
1606 write_seqcount_begin(&init_net.ct.generation);
1608 /* Lookups in the old hash might happen in parallel, which means we
1609 * might get false negatives during connection lookup. New connections
1610 * created because of a false negative won't make it into the hash
1611 * though since that required taking the locks.
1614 for (i = 0; i < init_net.ct.htable_size; i++) {
1615 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1616 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1617 struct nf_conntrack_tuple_hash, hnnode);
1618 ct = nf_ct_tuplehash_to_ctrack(h);
1619 hlist_nulls_del_rcu(&h->hnnode);
1620 bucket = __hash_conntrack(&h->tuple, hashsize);
1621 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1624 old_size = init_net.ct.htable_size;
1625 old_hash = init_net.ct.hash;
1627 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1628 init_net.ct.hash = hash;
1630 write_seqcount_end(&init_net.ct.generation);
1631 nf_conntrack_all_unlock();
1634 nf_ct_free_hashtable(old_hash, old_size);
1637 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1639 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1640 &nf_conntrack_htable_size, 0600);
1642 void nf_ct_untracked_status_or(unsigned long bits)
1646 for_each_possible_cpu(cpu)
1647 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1649 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1651 int nf_conntrack_init_start(void)
1656 for (i = 0; i < CONNTRACK_LOCKS; i++)
1657 spin_lock_init(&nf_conntrack_locks[i]);
1659 if (!nf_conntrack_htable_size) {
1660 /* Idea from tcp.c: use 1/16384 of memory.
1661 * On i386: 32MB machine has 512 buckets.
1662 * >= 1GB machines have 16384 buckets.
1663 * >= 4GB machines have 65536 buckets.
1665 nf_conntrack_htable_size
1666 = (((totalram_pages << PAGE_SHIFT) / 16384)
1667 / sizeof(struct hlist_head));
1668 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1669 nf_conntrack_htable_size = 65536;
1670 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1671 nf_conntrack_htable_size = 16384;
1672 if (nf_conntrack_htable_size < 32)
1673 nf_conntrack_htable_size = 32;
1675 /* Use a max. factor of four by default to get the same max as
1676 * with the old struct list_heads. When a table size is given
1677 * we use the old value of 8 to avoid reducing the max.
1681 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1683 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1684 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1687 ret = nf_conntrack_expect_init();
1691 ret = nf_conntrack_acct_init();
1695 ret = nf_conntrack_tstamp_init();
1699 ret = nf_conntrack_ecache_init();
1703 ret = nf_conntrack_timeout_init();
1707 ret = nf_conntrack_helper_init();
1711 ret = nf_conntrack_labels_init();
1715 ret = nf_conntrack_seqadj_init();
1719 #ifdef CONFIG_NF_CONNTRACK_ZONES
1720 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1724 ret = nf_conntrack_proto_init();
1728 /* Set up fake conntrack: to never be deleted, not in any hashes */
1729 for_each_possible_cpu(cpu) {
1730 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1731 write_pnet(&ct->ct_net, &init_net);
1732 atomic_set(&ct->ct_general.use, 1);
1734 /* - and look it like as a confirmed connection */
1735 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1739 #ifdef CONFIG_NF_CONNTRACK_ZONES
1740 nf_ct_extend_unregister(&nf_ct_zone_extend);
1743 nf_conntrack_seqadj_fini();
1745 nf_conntrack_labels_fini();
1747 nf_conntrack_helper_fini();
1749 nf_conntrack_timeout_fini();
1751 nf_conntrack_ecache_fini();
1753 nf_conntrack_tstamp_fini();
1755 nf_conntrack_acct_fini();
1757 nf_conntrack_expect_fini();
1762 void nf_conntrack_init_end(void)
1764 /* For use by REJECT target */
1765 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1766 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1770 * We need to use special "null" values, not used in hash table
1772 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1773 #define DYING_NULLS_VAL ((1<<30)+1)
1774 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1776 int nf_conntrack_init_net(struct net *net)
1781 atomic_set(&net->ct.count, 0);
1782 seqcount_init(&net->ct.generation);
1784 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1785 if (!net->ct.pcpu_lists)
1788 for_each_possible_cpu(cpu) {
1789 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1791 spin_lock_init(&pcpu->lock);
1792 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1793 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1796 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1798 goto err_pcpu_lists;
1800 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1801 if (!net->ct.slabname)
1804 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1805 sizeof(struct nf_conn), 0,
1806 SLAB_DESTROY_BY_RCU, NULL);
1807 if (!net->ct.nf_conntrack_cachep) {
1808 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1812 net->ct.htable_size = nf_conntrack_htable_size;
1813 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1814 if (!net->ct.hash) {
1815 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1818 ret = nf_conntrack_expect_pernet_init(net);
1821 ret = nf_conntrack_acct_pernet_init(net);
1824 ret = nf_conntrack_tstamp_pernet_init(net);
1827 ret = nf_conntrack_ecache_pernet_init(net);
1830 ret = nf_conntrack_helper_pernet_init(net);
1833 ret = nf_conntrack_proto_pernet_init(net);
1839 nf_conntrack_helper_pernet_fini(net);
1841 nf_conntrack_ecache_pernet_fini(net);
1843 nf_conntrack_tstamp_pernet_fini(net);
1845 nf_conntrack_acct_pernet_fini(net);
1847 nf_conntrack_expect_pernet_fini(net);
1849 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1851 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1853 kfree(net->ct.slabname);
1855 free_percpu(net->ct.stat);
1857 free_percpu(net->ct.pcpu_lists);