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 void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
71 h1 %= CONNTRACK_LOCKS;
72 h2 %= CONNTRACK_LOCKS;
73 spin_unlock(&nf_conntrack_locks[h1]);
75 spin_unlock(&nf_conntrack_locks[h2]);
78 /* return true if we need to recompute hashes (in case hash table was resized) */
79 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
80 unsigned int h2, unsigned int sequence)
82 h1 %= CONNTRACK_LOCKS;
83 h2 %= CONNTRACK_LOCKS;
85 spin_lock(&nf_conntrack_locks[h1]);
87 spin_lock_nested(&nf_conntrack_locks[h2],
88 SINGLE_DEPTH_NESTING);
90 spin_lock(&nf_conntrack_locks[h2]);
91 spin_lock_nested(&nf_conntrack_locks[h1],
92 SINGLE_DEPTH_NESTING);
94 if (read_seqcount_retry(&net->ct.generation, sequence)) {
95 nf_conntrack_double_unlock(h1, h2);
101 static void nf_conntrack_all_lock(void)
105 for (i = 0; i < CONNTRACK_LOCKS; i++)
106 spin_lock_nested(&nf_conntrack_locks[i], i);
109 static void nf_conntrack_all_unlock(void)
113 for (i = 0; i < CONNTRACK_LOCKS; i++)
114 spin_unlock(&nf_conntrack_locks[i]);
117 unsigned int nf_conntrack_htable_size __read_mostly;
118 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
120 unsigned int nf_conntrack_max __read_mostly;
121 EXPORT_SYMBOL_GPL(nf_conntrack_max);
123 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
124 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
126 unsigned int nf_conntrack_hash_rnd __read_mostly;
127 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
129 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
133 /* The direction must be ignored, so we hash everything up to the
134 * destination ports (which is a multiple of 4) and treat the last
135 * three bytes manually.
137 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
138 return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
139 (((__force __u16)tuple->dst.u.all << 16) |
140 tuple->dst.protonum));
143 static u32 __hash_bucket(u32 hash, unsigned int size)
145 return reciprocal_scale(hash, size);
148 static u32 hash_bucket(u32 hash, const struct net *net)
150 return __hash_bucket(hash, net->ct.htable_size);
153 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
154 u16 zone, unsigned int size)
156 return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
159 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
160 const struct nf_conntrack_tuple *tuple)
162 return __hash_conntrack(tuple, zone, net->ct.htable_size);
166 nf_ct_get_tuple(const struct sk_buff *skb,
168 unsigned int dataoff,
171 struct nf_conntrack_tuple *tuple,
172 const struct nf_conntrack_l3proto *l3proto,
173 const struct nf_conntrack_l4proto *l4proto)
175 memset(tuple, 0, sizeof(*tuple));
177 tuple->src.l3num = l3num;
178 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
181 tuple->dst.protonum = protonum;
182 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
184 return l4proto->pkt_to_tuple(skb, dataoff, tuple);
186 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
188 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
189 u_int16_t l3num, struct nf_conntrack_tuple *tuple)
191 struct nf_conntrack_l3proto *l3proto;
192 struct nf_conntrack_l4proto *l4proto;
193 unsigned int protoff;
199 l3proto = __nf_ct_l3proto_find(l3num);
200 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
201 if (ret != NF_ACCEPT) {
206 l4proto = __nf_ct_l4proto_find(l3num, protonum);
208 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
214 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
217 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
218 const struct nf_conntrack_tuple *orig,
219 const struct nf_conntrack_l3proto *l3proto,
220 const struct nf_conntrack_l4proto *l4proto)
222 memset(inverse, 0, sizeof(*inverse));
224 inverse->src.l3num = orig->src.l3num;
225 if (l3proto->invert_tuple(inverse, orig) == 0)
228 inverse->dst.dir = !orig->dst.dir;
230 inverse->dst.protonum = orig->dst.protonum;
231 return l4proto->invert_tuple(inverse, orig);
233 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
236 clean_from_lists(struct nf_conn *ct)
238 pr_debug("clean_from_lists(%p)\n", ct);
239 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
240 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
242 /* Destroy all pending expectations */
243 nf_ct_remove_expectations(ct);
246 /* must be called with local_bh_disable */
247 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
249 struct ct_pcpu *pcpu;
251 /* add this conntrack to the (per cpu) dying list */
252 ct->cpu = smp_processor_id();
253 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
255 spin_lock(&pcpu->lock);
256 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
258 spin_unlock(&pcpu->lock);
261 /* must be called with local_bh_disable */
262 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
264 struct ct_pcpu *pcpu;
266 /* add this conntrack to the (per cpu) unconfirmed list */
267 ct->cpu = smp_processor_id();
268 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
270 spin_lock(&pcpu->lock);
271 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
273 spin_unlock(&pcpu->lock);
276 /* must be called with local_bh_disable */
277 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
279 struct ct_pcpu *pcpu;
281 /* We overload first tuple to link into unconfirmed or dying list.*/
282 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
284 spin_lock(&pcpu->lock);
285 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
286 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
287 spin_unlock(&pcpu->lock);
291 destroy_conntrack(struct nf_conntrack *nfct)
293 struct nf_conn *ct = (struct nf_conn *)nfct;
294 struct net *net = nf_ct_net(ct);
295 struct nf_conntrack_l4proto *l4proto;
297 pr_debug("destroy_conntrack(%p)\n", ct);
298 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
299 NF_CT_ASSERT(!timer_pending(&ct->timeout));
302 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
303 if (l4proto && l4proto->destroy)
304 l4proto->destroy(ct);
309 /* Expectations will have been removed in clean_from_lists,
310 * except TFTP can create an expectation on the first packet,
311 * before connection is in the list, so we need to clean here,
314 nf_ct_remove_expectations(ct);
316 nf_ct_del_from_dying_or_unconfirmed_list(ct);
318 NF_CT_STAT_INC(net, delete);
322 nf_ct_put(ct->master);
324 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
325 nf_conntrack_free(ct);
328 static void nf_ct_delete_from_lists(struct nf_conn *ct)
330 struct net *net = nf_ct_net(ct);
331 unsigned int hash, reply_hash;
332 u16 zone = nf_ct_zone(ct);
333 unsigned int sequence;
335 nf_ct_helper_destroy(ct);
339 sequence = read_seqcount_begin(&net->ct.generation);
340 hash = hash_conntrack(net, zone,
341 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
342 reply_hash = hash_conntrack(net, zone,
343 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
344 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
346 clean_from_lists(ct);
347 nf_conntrack_double_unlock(hash, reply_hash);
349 nf_ct_add_to_dying_list(ct);
351 NF_CT_STAT_INC(net, delete_list);
355 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
357 struct nf_conn_tstamp *tstamp;
359 tstamp = nf_conn_tstamp_find(ct);
360 if (tstamp && tstamp->stop == 0)
361 tstamp->stop = ktime_get_real_ns();
363 if (nf_ct_is_dying(ct))
366 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
367 portid, report) < 0) {
368 /* destroy event was not delivered */
369 nf_ct_delete_from_lists(ct);
370 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
374 nf_conntrack_ecache_work(nf_ct_net(ct));
375 set_bit(IPS_DYING_BIT, &ct->status);
377 nf_ct_delete_from_lists(ct);
381 EXPORT_SYMBOL_GPL(nf_ct_delete);
383 static void death_by_timeout(unsigned long ul_conntrack)
385 nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
389 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
390 const struct nf_conntrack_tuple *tuple,
393 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
395 /* A conntrack can be recreated with the equal tuple,
396 * so we need to check that the conntrack is confirmed
398 return nf_ct_tuple_equal(tuple, &h->tuple) &&
399 nf_ct_zone(ct) == zone &&
400 nf_ct_is_confirmed(ct);
405 * - Caller must take a reference on returned object
406 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
408 static struct nf_conntrack_tuple_hash *
409 ____nf_conntrack_find(struct net *net, u16 zone,
410 const struct nf_conntrack_tuple *tuple, u32 hash)
412 struct nf_conntrack_tuple_hash *h;
413 struct hlist_nulls_node *n;
414 unsigned int bucket = hash_bucket(hash, net);
416 /* Disable BHs the entire time since we normally need to disable them
417 * at least once for the stats anyway.
421 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
422 if (nf_ct_key_equal(h, tuple, zone)) {
423 NF_CT_STAT_INC(net, found);
427 NF_CT_STAT_INC(net, searched);
430 * if the nulls value we got at the end of this lookup is
431 * not the expected one, we must restart lookup.
432 * We probably met an item that was moved to another chain.
434 if (get_nulls_value(n) != bucket) {
435 NF_CT_STAT_INC(net, search_restart);
443 /* Find a connection corresponding to a tuple. */
444 static struct nf_conntrack_tuple_hash *
445 __nf_conntrack_find_get(struct net *net, u16 zone,
446 const struct nf_conntrack_tuple *tuple, u32 hash)
448 struct nf_conntrack_tuple_hash *h;
453 h = ____nf_conntrack_find(net, zone, tuple, hash);
455 ct = nf_ct_tuplehash_to_ctrack(h);
456 if (unlikely(nf_ct_is_dying(ct) ||
457 !atomic_inc_not_zero(&ct->ct_general.use)))
460 if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
471 struct nf_conntrack_tuple_hash *
472 nf_conntrack_find_get(struct net *net, u16 zone,
473 const struct nf_conntrack_tuple *tuple)
475 return __nf_conntrack_find_get(net, zone, tuple,
476 hash_conntrack_raw(tuple, zone));
478 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
480 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
482 unsigned int reply_hash)
484 struct net *net = nf_ct_net(ct);
486 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
487 &net->ct.hash[hash]);
488 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
489 &net->ct.hash[reply_hash]);
493 nf_conntrack_hash_check_insert(struct nf_conn *ct)
495 struct net *net = nf_ct_net(ct);
496 unsigned int hash, reply_hash;
497 struct nf_conntrack_tuple_hash *h;
498 struct hlist_nulls_node *n;
500 unsigned int sequence;
502 zone = nf_ct_zone(ct);
506 sequence = read_seqcount_begin(&net->ct.generation);
507 hash = hash_conntrack(net, zone,
508 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
509 reply_hash = hash_conntrack(net, zone,
510 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
511 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
513 /* See if there's one in the list already, including reverse */
514 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
515 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
517 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
519 hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
520 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
522 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
525 add_timer(&ct->timeout);
527 /* The caller holds a reference to this object */
528 atomic_set(&ct->ct_general.use, 2);
529 __nf_conntrack_hash_insert(ct, hash, reply_hash);
530 nf_conntrack_double_unlock(hash, reply_hash);
531 NF_CT_STAT_INC(net, insert);
536 nf_conntrack_double_unlock(hash, reply_hash);
537 NF_CT_STAT_INC(net, insert_failed);
541 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
543 /* deletion from this larval template list happens via nf_ct_put() */
544 void nf_conntrack_tmpl_insert(struct net *net, struct nf_conn *tmpl)
546 struct ct_pcpu *pcpu;
548 __set_bit(IPS_TEMPLATE_BIT, &tmpl->status);
549 __set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
550 nf_conntrack_get(&tmpl->ct_general);
552 /* add this conntrack to the (per cpu) tmpl list */
554 tmpl->cpu = smp_processor_id();
555 pcpu = per_cpu_ptr(nf_ct_net(tmpl)->ct.pcpu_lists, tmpl->cpu);
557 spin_lock(&pcpu->lock);
558 /* Overload tuple linked list to put us in template list. */
559 hlist_nulls_add_head_rcu(&tmpl->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
561 spin_unlock_bh(&pcpu->lock);
563 EXPORT_SYMBOL_GPL(nf_conntrack_tmpl_insert);
565 /* Confirm a connection given skb; places it in hash table */
567 __nf_conntrack_confirm(struct sk_buff *skb)
569 unsigned int hash, reply_hash;
570 struct nf_conntrack_tuple_hash *h;
572 struct nf_conn_help *help;
573 struct nf_conn_tstamp *tstamp;
574 struct hlist_nulls_node *n;
575 enum ip_conntrack_info ctinfo;
578 unsigned int sequence;
580 ct = nf_ct_get(skb, &ctinfo);
583 /* ipt_REJECT uses nf_conntrack_attach to attach related
584 ICMP/TCP RST packets in other direction. Actual packet
585 which created connection will be IP_CT_NEW or for an
586 expected connection, IP_CT_RELATED. */
587 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
590 zone = nf_ct_zone(ct);
594 sequence = read_seqcount_begin(&net->ct.generation);
595 /* reuse the hash saved before */
596 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
597 hash = hash_bucket(hash, net);
598 reply_hash = hash_conntrack(net, zone,
599 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
601 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
603 /* We're not in hash table, and we refuse to set up related
604 * connections for unconfirmed conns. But packet copies and
605 * REJECT will give spurious warnings here.
607 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
609 /* No external references means no one else could have
612 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
613 pr_debug("Confirming conntrack %p\n", ct);
614 /* We have to check the DYING flag inside the lock to prevent
615 a race against nf_ct_get_next_corpse() possibly called from
616 user context, else we insert an already 'dead' hash, blocking
617 further use of that particular connection -JM */
619 if (unlikely(nf_ct_is_dying(ct))) {
620 nf_conntrack_double_unlock(hash, reply_hash);
625 /* See if there's one in the list already, including reverse:
626 NAT could have grabbed it without realizing, since we're
627 not in the hash. If there is, we lost race. */
628 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
629 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
631 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
633 hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
634 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
636 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
639 nf_ct_del_from_dying_or_unconfirmed_list(ct);
641 /* Timer relative to confirmation time, not original
642 setting time, otherwise we'd get timer wrap in
643 weird delay cases. */
644 ct->timeout.expires += jiffies;
645 add_timer(&ct->timeout);
646 atomic_inc(&ct->ct_general.use);
647 ct->status |= IPS_CONFIRMED;
649 /* set conntrack timestamp, if enabled. */
650 tstamp = nf_conn_tstamp_find(ct);
652 if (skb->tstamp.tv64 == 0)
653 __net_timestamp(skb);
655 tstamp->start = ktime_to_ns(skb->tstamp);
657 /* Since the lookup is lockless, hash insertion must be done after
658 * starting the timer and setting the CONFIRMED bit. The RCU barriers
659 * guarantee that no other CPU can find the conntrack before the above
660 * stores are visible.
662 __nf_conntrack_hash_insert(ct, hash, reply_hash);
663 nf_conntrack_double_unlock(hash, reply_hash);
664 NF_CT_STAT_INC(net, insert);
667 help = nfct_help(ct);
668 if (help && help->helper)
669 nf_conntrack_event_cache(IPCT_HELPER, ct);
671 nf_conntrack_event_cache(master_ct(ct) ?
672 IPCT_RELATED : IPCT_NEW, ct);
676 nf_conntrack_double_unlock(hash, reply_hash);
677 NF_CT_STAT_INC(net, insert_failed);
681 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
683 /* Returns true if a connection correspondings to the tuple (required
686 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
687 const struct nf_conn *ignored_conntrack)
689 struct net *net = nf_ct_net(ignored_conntrack);
690 struct nf_conntrack_tuple_hash *h;
691 struct hlist_nulls_node *n;
693 u16 zone = nf_ct_zone(ignored_conntrack);
694 unsigned int hash = hash_conntrack(net, zone, tuple);
696 /* Disable BHs the entire time since we need to disable them at
697 * least once for the stats anyway.
700 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
701 ct = nf_ct_tuplehash_to_ctrack(h);
702 if (ct != ignored_conntrack &&
703 nf_ct_tuple_equal(tuple, &h->tuple) &&
704 nf_ct_zone(ct) == zone) {
705 NF_CT_STAT_INC(net, found);
706 rcu_read_unlock_bh();
709 NF_CT_STAT_INC(net, searched);
711 rcu_read_unlock_bh();
715 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
717 #define NF_CT_EVICTION_RANGE 8
719 /* There's a small race here where we may free a just-assured
720 connection. Too bad: we're in trouble anyway. */
721 static noinline int early_drop(struct net *net, unsigned int _hash)
723 /* Use oldest entry, which is roughly LRU */
724 struct nf_conntrack_tuple_hash *h;
725 struct nf_conn *ct = NULL, *tmp;
726 struct hlist_nulls_node *n;
727 unsigned int i = 0, cnt = 0;
729 unsigned int hash, sequence;
734 sequence = read_seqcount_begin(&net->ct.generation);
735 hash = hash_bucket(_hash, net);
736 for (; i < net->ct.htable_size; i++) {
737 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
739 if (read_seqcount_retry(&net->ct.generation, sequence)) {
743 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
745 tmp = nf_ct_tuplehash_to_ctrack(h);
746 if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
747 !nf_ct_is_dying(tmp) &&
748 atomic_inc_not_zero(&tmp->ct_general.use)) {
755 hash = (hash + 1) % net->ct.htable_size;
758 if (ct || cnt >= NF_CT_EVICTION_RANGE)
767 if (del_timer(&ct->timeout)) {
768 if (nf_ct_delete(ct, 0, 0)) {
770 NF_CT_STAT_INC_ATOMIC(net, early_drop);
777 void init_nf_conntrack_hash_rnd(void)
782 * Why not initialize nf_conntrack_rnd in a "init()" function ?
783 * Because there isn't enough entropy when system initializing,
784 * and we initialize it as late as possible.
787 get_random_bytes(&rand, sizeof(rand));
789 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
792 static struct nf_conn *
793 __nf_conntrack_alloc(struct net *net, u16 zone,
794 const struct nf_conntrack_tuple *orig,
795 const struct nf_conntrack_tuple *repl,
800 if (unlikely(!nf_conntrack_hash_rnd)) {
801 init_nf_conntrack_hash_rnd();
802 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
803 hash = hash_conntrack_raw(orig, zone);
806 /* We don't want any race condition at early drop stage */
807 atomic_inc(&net->ct.count);
809 if (nf_conntrack_max &&
810 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
811 if (!early_drop(net, hash)) {
812 atomic_dec(&net->ct.count);
813 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
814 return ERR_PTR(-ENOMEM);
819 * Do not use kmem_cache_zalloc(), as this cache uses
820 * SLAB_DESTROY_BY_RCU.
822 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
824 atomic_dec(&net->ct.count);
825 return ERR_PTR(-ENOMEM);
828 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
829 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
831 memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
832 offsetof(struct nf_conn, proto) -
833 offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
834 spin_lock_init(&ct->lock);
835 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
836 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
837 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
838 /* save hash for reusing when confirming */
839 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
840 /* Don't set timer yet: wait for confirmation */
841 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
842 write_pnet(&ct->ct_net, net);
843 #ifdef CONFIG_NF_CONNTRACK_ZONES
845 struct nf_conntrack_zone *nf_ct_zone;
847 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
850 nf_ct_zone->id = zone;
853 /* Because we use RCU lookups, we set ct_general.use to zero before
854 * this is inserted in any list.
856 atomic_set(&ct->ct_general.use, 0);
859 #ifdef CONFIG_NF_CONNTRACK_ZONES
861 atomic_dec(&net->ct.count);
862 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
863 return ERR_PTR(-ENOMEM);
867 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
868 const struct nf_conntrack_tuple *orig,
869 const struct nf_conntrack_tuple *repl,
872 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
874 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
876 void nf_conntrack_free(struct nf_conn *ct)
878 struct net *net = nf_ct_net(ct);
880 /* A freed object has refcnt == 0, that's
881 * the golden rule for SLAB_DESTROY_BY_RCU
883 NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
885 nf_ct_ext_destroy(ct);
887 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
888 smp_mb__before_atomic();
889 atomic_dec(&net->ct.count);
891 EXPORT_SYMBOL_GPL(nf_conntrack_free);
894 /* Allocate a new conntrack: we return -ENOMEM if classification
895 failed due to stress. Otherwise it really is unclassifiable. */
896 static struct nf_conntrack_tuple_hash *
897 init_conntrack(struct net *net, struct nf_conn *tmpl,
898 const struct nf_conntrack_tuple *tuple,
899 struct nf_conntrack_l3proto *l3proto,
900 struct nf_conntrack_l4proto *l4proto,
902 unsigned int dataoff, u32 hash)
905 struct nf_conn_help *help;
906 struct nf_conntrack_tuple repl_tuple;
907 struct nf_conntrack_ecache *ecache;
908 struct nf_conntrack_expect *exp = NULL;
909 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
910 struct nf_conn_timeout *timeout_ext;
911 unsigned int *timeouts;
913 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
914 pr_debug("Can't invert tuple.\n");
918 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
921 return (struct nf_conntrack_tuple_hash *)ct;
923 if (tmpl && nfct_synproxy(tmpl)) {
924 nfct_seqadj_ext_add(ct);
925 nfct_synproxy_ext_add(ct);
928 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
930 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
932 timeouts = l4proto->get_timeouts(net);
934 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
935 nf_conntrack_free(ct);
936 pr_debug("init conntrack: can't track with proto module\n");
941 nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);
943 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
944 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
945 nf_ct_labels_ext_add(ct);
947 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
948 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
949 ecache ? ecache->expmask : 0,
953 if (net->ct.expect_count) {
954 spin_lock(&nf_conntrack_expect_lock);
955 exp = nf_ct_find_expectation(net, zone, tuple);
957 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
959 /* Welcome, Mr. Bond. We've been expecting you... */
960 __set_bit(IPS_EXPECTED_BIT, &ct->status);
961 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
962 ct->master = exp->master;
964 help = nf_ct_helper_ext_add(ct, exp->helper,
967 rcu_assign_pointer(help->helper, exp->helper);
970 #ifdef CONFIG_NF_CONNTRACK_MARK
971 ct->mark = exp->master->mark;
973 #ifdef CONFIG_NF_CONNTRACK_SECMARK
974 ct->secmark = exp->master->secmark;
976 NF_CT_STAT_INC(net, expect_new);
978 spin_unlock(&nf_conntrack_expect_lock);
981 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
982 NF_CT_STAT_INC(net, new);
985 /* Now it is inserted into the unconfirmed list, bump refcount */
986 nf_conntrack_get(&ct->ct_general);
987 nf_ct_add_to_unconfirmed_list(ct);
993 exp->expectfn(ct, exp);
994 nf_ct_expect_put(exp);
997 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1000 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1001 static inline struct nf_conn *
1002 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1003 struct sk_buff *skb,
1004 unsigned int dataoff,
1007 struct nf_conntrack_l3proto *l3proto,
1008 struct nf_conntrack_l4proto *l4proto,
1010 enum ip_conntrack_info *ctinfo)
1012 struct nf_conntrack_tuple tuple;
1013 struct nf_conntrack_tuple_hash *h;
1015 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
1018 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1019 dataoff, l3num, protonum, &tuple, l3proto,
1021 pr_debug("resolve_normal_ct: Can't get tuple\n");
1025 /* look for tuple match */
1026 hash = hash_conntrack_raw(&tuple, zone);
1027 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1029 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1030 skb, dataoff, hash);
1036 ct = nf_ct_tuplehash_to_ctrack(h);
1038 /* It exists; we have (non-exclusive) reference. */
1039 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1040 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1041 /* Please set reply bit if this packet OK */
1044 /* Once we've had two way comms, always ESTABLISHED. */
1045 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1046 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
1047 *ctinfo = IP_CT_ESTABLISHED;
1048 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1049 pr_debug("nf_conntrack_in: related packet for %p\n",
1051 *ctinfo = IP_CT_RELATED;
1053 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
1054 *ctinfo = IP_CT_NEW;
1058 skb->nfct = &ct->ct_general;
1059 skb->nfctinfo = *ctinfo;
1064 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1065 struct sk_buff *skb)
1067 struct nf_conn *ct, *tmpl = NULL;
1068 enum ip_conntrack_info ctinfo;
1069 struct nf_conntrack_l3proto *l3proto;
1070 struct nf_conntrack_l4proto *l4proto;
1071 unsigned int *timeouts;
1072 unsigned int dataoff;
1078 /* Previously seen (loopback or untracked)? Ignore. */
1079 tmpl = (struct nf_conn *)skb->nfct;
1080 if (!nf_ct_is_template(tmpl)) {
1081 NF_CT_STAT_INC_ATOMIC(net, ignore);
1087 /* rcu_read_lock()ed by nf_hook_slow */
1088 l3proto = __nf_ct_l3proto_find(pf);
1089 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1090 &dataoff, &protonum);
1092 pr_debug("not prepared to track yet or error occurred\n");
1093 NF_CT_STAT_INC_ATOMIC(net, error);
1094 NF_CT_STAT_INC_ATOMIC(net, invalid);
1099 l4proto = __nf_ct_l4proto_find(pf, protonum);
1101 /* It may be an special packet, error, unclean...
1102 * inverse of the return code tells to the netfilter
1103 * core what to do with the packet. */
1104 if (l4proto->error != NULL) {
1105 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1108 NF_CT_STAT_INC_ATOMIC(net, error);
1109 NF_CT_STAT_INC_ATOMIC(net, invalid);
1113 /* ICMP[v6] protocol trackers may assign one conntrack. */
1118 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1119 l3proto, l4proto, &set_reply, &ctinfo);
1121 /* Not valid part of a connection */
1122 NF_CT_STAT_INC_ATOMIC(net, invalid);
1128 /* Too stressed to deal. */
1129 NF_CT_STAT_INC_ATOMIC(net, drop);
1134 NF_CT_ASSERT(skb->nfct);
1136 /* Decide what timeout policy we want to apply to this flow. */
1137 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1139 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1141 /* Invalid: inverse of the return code tells
1142 * the netfilter core what to do */
1143 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1144 nf_conntrack_put(skb->nfct);
1146 NF_CT_STAT_INC_ATOMIC(net, invalid);
1147 if (ret == -NF_DROP)
1148 NF_CT_STAT_INC_ATOMIC(net, drop);
1153 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1154 nf_conntrack_event_cache(IPCT_REPLY, ct);
1157 /* Special case: we have to repeat this hook, assign the
1158 * template again to this packet. We assume that this packet
1159 * has no conntrack assigned. This is used by nf_ct_tcp. */
1160 if (ret == NF_REPEAT)
1161 skb->nfct = (struct nf_conntrack *)tmpl;
1168 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1170 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1171 const struct nf_conntrack_tuple *orig)
1176 ret = nf_ct_invert_tuple(inverse, orig,
1177 __nf_ct_l3proto_find(orig->src.l3num),
1178 __nf_ct_l4proto_find(orig->src.l3num,
1179 orig->dst.protonum));
1183 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1185 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1186 implicitly racy: see __nf_conntrack_confirm */
1187 void nf_conntrack_alter_reply(struct nf_conn *ct,
1188 const struct nf_conntrack_tuple *newreply)
1190 struct nf_conn_help *help = nfct_help(ct);
1192 /* Should be unconfirmed, so not in hash table yet */
1193 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1195 pr_debug("Altering reply tuple of %p to ", ct);
1196 nf_ct_dump_tuple(newreply);
1198 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1199 if (ct->master || (help && !hlist_empty(&help->expectations)))
1203 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1206 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1208 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1209 void __nf_ct_refresh_acct(struct nf_conn *ct,
1210 enum ip_conntrack_info ctinfo,
1211 const struct sk_buff *skb,
1212 unsigned long extra_jiffies,
1215 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1218 /* Only update if this is not a fixed timeout */
1219 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1222 /* If not in hash table, timer will not be active yet */
1223 if (!nf_ct_is_confirmed(ct)) {
1224 ct->timeout.expires = extra_jiffies;
1226 unsigned long newtime = jiffies + extra_jiffies;
1228 /* Only update the timeout if the new timeout is at least
1229 HZ jiffies from the old timeout. Need del_timer for race
1230 avoidance (may already be dying). */
1231 if (newtime - ct->timeout.expires >= HZ)
1232 mod_timer_pending(&ct->timeout, newtime);
1237 struct nf_conn_acct *acct;
1239 acct = nf_conn_acct_find(ct);
1241 struct nf_conn_counter *counter = acct->counter;
1243 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1244 atomic64_add(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
1248 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1250 bool __nf_ct_kill_acct(struct nf_conn *ct,
1251 enum ip_conntrack_info ctinfo,
1252 const struct sk_buff *skb,
1256 struct nf_conn_acct *acct;
1258 acct = nf_conn_acct_find(ct);
1260 struct nf_conn_counter *counter = acct->counter;
1262 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
1263 atomic64_add(skb->len - skb_network_offset(skb),
1264 &counter[CTINFO2DIR(ctinfo)].bytes);
1268 if (del_timer(&ct->timeout)) {
1269 ct->timeout.function((unsigned long)ct);
1274 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1276 #ifdef CONFIG_NF_CONNTRACK_ZONES
1277 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1278 .len = sizeof(struct nf_conntrack_zone),
1279 .align = __alignof__(struct nf_conntrack_zone),
1280 .id = NF_CT_EXT_ZONE,
1284 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1286 #include <linux/netfilter/nfnetlink.h>
1287 #include <linux/netfilter/nfnetlink_conntrack.h>
1288 #include <linux/mutex.h>
1290 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1291 * in ip_conntrack_core, since we don't want the protocols to autoload
1292 * or depend on ctnetlink */
1293 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1294 const struct nf_conntrack_tuple *tuple)
1296 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1297 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1298 goto nla_put_failure;
1304 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1306 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1307 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1308 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1310 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1312 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1313 struct nf_conntrack_tuple *t)
1315 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1318 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1319 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1323 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1325 int nf_ct_port_nlattr_tuple_size(void)
1327 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1329 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1332 /* Used by ipt_REJECT and ip6t_REJECT. */
1333 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1336 enum ip_conntrack_info ctinfo;
1338 /* This ICMP is in reverse direction to the packet which caused it */
1339 ct = nf_ct_get(skb, &ctinfo);
1340 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1341 ctinfo = IP_CT_RELATED_REPLY;
1343 ctinfo = IP_CT_RELATED;
1345 /* Attach to new skbuff, and increment count */
1346 nskb->nfct = &ct->ct_general;
1347 nskb->nfctinfo = ctinfo;
1348 nf_conntrack_get(nskb->nfct);
1351 /* Bring out ya dead! */
1352 static struct nf_conn *
1353 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1354 void *data, unsigned int *bucket)
1356 struct nf_conntrack_tuple_hash *h;
1358 struct hlist_nulls_node *n;
1362 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1363 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1366 if (*bucket < net->ct.htable_size) {
1367 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1368 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1370 ct = nf_ct_tuplehash_to_ctrack(h);
1379 for_each_possible_cpu(cpu) {
1380 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1382 spin_lock_bh(&pcpu->lock);
1383 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1384 ct = nf_ct_tuplehash_to_ctrack(h);
1386 set_bit(IPS_DYING_BIT, &ct->status);
1388 spin_unlock_bh(&pcpu->lock);
1392 atomic_inc(&ct->ct_general.use);
1398 void nf_ct_iterate_cleanup(struct net *net,
1399 int (*iter)(struct nf_conn *i, void *data),
1400 void *data, u32 portid, int report)
1403 unsigned int bucket = 0;
1405 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1406 /* Time to push up daises... */
1407 if (del_timer(&ct->timeout))
1408 nf_ct_delete(ct, portid, report);
1410 /* ... else the timer will get him soon. */
1415 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1417 static int kill_all(struct nf_conn *i, void *data)
1422 void nf_ct_free_hashtable(void *hash, unsigned int size)
1424 if (is_vmalloc_addr(hash))
1427 free_pages((unsigned long)hash,
1428 get_order(sizeof(struct hlist_head) * size));
1430 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1432 void nf_conntrack_flush_report(struct net *net, u32 portid, int report)
1434 nf_ct_iterate_cleanup(net, kill_all, NULL, portid, report);
1436 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1438 static int untrack_refs(void)
1442 for_each_possible_cpu(cpu) {
1443 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1445 cnt += atomic_read(&ct->ct_general.use) - 1;
1450 void nf_conntrack_cleanup_start(void)
1452 RCU_INIT_POINTER(ip_ct_attach, NULL);
1455 void nf_conntrack_cleanup_end(void)
1457 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1458 while (untrack_refs() > 0)
1461 #ifdef CONFIG_NF_CONNTRACK_ZONES
1462 nf_ct_extend_unregister(&nf_ct_zone_extend);
1464 nf_conntrack_proto_fini();
1465 nf_conntrack_seqadj_fini();
1466 nf_conntrack_labels_fini();
1467 nf_conntrack_helper_fini();
1468 nf_conntrack_timeout_fini();
1469 nf_conntrack_ecache_fini();
1470 nf_conntrack_tstamp_fini();
1471 nf_conntrack_acct_fini();
1472 nf_conntrack_expect_fini();
1476 * Mishearing the voices in his head, our hero wonders how he's
1477 * supposed to kill the mall.
1479 void nf_conntrack_cleanup_net(struct net *net)
1483 list_add(&net->exit_list, &single);
1484 nf_conntrack_cleanup_net_list(&single);
1487 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1493 * This makes sure all current packets have passed through
1494 * netfilter framework. Roll on, two-stage module
1500 list_for_each_entry(net, net_exit_list, exit_list) {
1501 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1502 if (atomic_read(&net->ct.count) != 0)
1507 goto i_see_dead_people;
1510 list_for_each_entry(net, net_exit_list, exit_list) {
1511 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1512 nf_conntrack_proto_pernet_fini(net);
1513 nf_conntrack_helper_pernet_fini(net);
1514 nf_conntrack_ecache_pernet_fini(net);
1515 nf_conntrack_tstamp_pernet_fini(net);
1516 nf_conntrack_acct_pernet_fini(net);
1517 nf_conntrack_expect_pernet_fini(net);
1518 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1519 kfree(net->ct.slabname);
1520 free_percpu(net->ct.stat);
1521 free_percpu(net->ct.pcpu_lists);
1525 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1527 struct hlist_nulls_head *hash;
1528 unsigned int nr_slots, i;
1531 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1532 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1533 sz = nr_slots * sizeof(struct hlist_nulls_head);
1534 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1537 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1542 for (i = 0; i < nr_slots; i++)
1543 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1547 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1549 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1552 unsigned int hashsize, old_size;
1553 struct hlist_nulls_head *hash, *old_hash;
1554 struct nf_conntrack_tuple_hash *h;
1557 if (current->nsproxy->net_ns != &init_net)
1560 /* On boot, we can set this without any fancy locking. */
1561 if (!nf_conntrack_htable_size)
1562 return param_set_uint(val, kp);
1564 rc = kstrtouint(val, 0, &hashsize);
1570 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1575 nf_conntrack_all_lock();
1576 write_seqcount_begin(&init_net.ct.generation);
1578 /* Lookups in the old hash might happen in parallel, which means we
1579 * might get false negatives during connection lookup. New connections
1580 * created because of a false negative won't make it into the hash
1581 * though since that required taking the locks.
1584 for (i = 0; i < init_net.ct.htable_size; i++) {
1585 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1586 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1587 struct nf_conntrack_tuple_hash, hnnode);
1588 ct = nf_ct_tuplehash_to_ctrack(h);
1589 hlist_nulls_del_rcu(&h->hnnode);
1590 bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1592 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1595 old_size = init_net.ct.htable_size;
1596 old_hash = init_net.ct.hash;
1598 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1599 init_net.ct.hash = hash;
1601 write_seqcount_end(&init_net.ct.generation);
1602 nf_conntrack_all_unlock();
1605 nf_ct_free_hashtable(old_hash, old_size);
1608 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1610 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1611 &nf_conntrack_htable_size, 0600);
1613 void nf_ct_untracked_status_or(unsigned long bits)
1617 for_each_possible_cpu(cpu)
1618 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1620 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1622 int nf_conntrack_init_start(void)
1627 for (i = 0; i < CONNTRACK_LOCKS; i++)
1628 spin_lock_init(&nf_conntrack_locks[i]);
1630 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1631 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1632 if (!nf_conntrack_htable_size) {
1633 nf_conntrack_htable_size
1634 = (((totalram_pages << PAGE_SHIFT) / 16384)
1635 / sizeof(struct hlist_head));
1636 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1637 nf_conntrack_htable_size = 16384;
1638 if (nf_conntrack_htable_size < 32)
1639 nf_conntrack_htable_size = 32;
1641 /* Use a max. factor of four by default to get the same max as
1642 * with the old struct list_heads. When a table size is given
1643 * we use the old value of 8 to avoid reducing the max.
1647 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1649 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1650 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1653 ret = nf_conntrack_expect_init();
1657 ret = nf_conntrack_acct_init();
1661 ret = nf_conntrack_tstamp_init();
1665 ret = nf_conntrack_ecache_init();
1669 ret = nf_conntrack_timeout_init();
1673 ret = nf_conntrack_helper_init();
1677 ret = nf_conntrack_labels_init();
1681 ret = nf_conntrack_seqadj_init();
1685 #ifdef CONFIG_NF_CONNTRACK_ZONES
1686 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1690 ret = nf_conntrack_proto_init();
1694 /* Set up fake conntrack: to never be deleted, not in any hashes */
1695 for_each_possible_cpu(cpu) {
1696 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1697 write_pnet(&ct->ct_net, &init_net);
1698 atomic_set(&ct->ct_general.use, 1);
1700 /* - and look it like as a confirmed connection */
1701 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1705 #ifdef CONFIG_NF_CONNTRACK_ZONES
1706 nf_ct_extend_unregister(&nf_ct_zone_extend);
1709 nf_conntrack_seqadj_fini();
1711 nf_conntrack_labels_fini();
1713 nf_conntrack_helper_fini();
1715 nf_conntrack_timeout_fini();
1717 nf_conntrack_ecache_fini();
1719 nf_conntrack_tstamp_fini();
1721 nf_conntrack_acct_fini();
1723 nf_conntrack_expect_fini();
1728 void nf_conntrack_init_end(void)
1730 /* For use by REJECT target */
1731 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1732 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1736 * We need to use special "null" values, not used in hash table
1738 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1739 #define DYING_NULLS_VAL ((1<<30)+1)
1740 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1742 int nf_conntrack_init_net(struct net *net)
1747 atomic_set(&net->ct.count, 0);
1748 seqcount_init(&net->ct.generation);
1750 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1751 if (!net->ct.pcpu_lists)
1754 for_each_possible_cpu(cpu) {
1755 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1757 spin_lock_init(&pcpu->lock);
1758 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1759 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1760 INIT_HLIST_NULLS_HEAD(&pcpu->tmpl, TEMPLATE_NULLS_VAL);
1763 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1765 goto err_pcpu_lists;
1767 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1768 if (!net->ct.slabname)
1771 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1772 sizeof(struct nf_conn), 0,
1773 SLAB_DESTROY_BY_RCU, NULL);
1774 if (!net->ct.nf_conntrack_cachep) {
1775 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1779 net->ct.htable_size = nf_conntrack_htable_size;
1780 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1781 if (!net->ct.hash) {
1782 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1785 ret = nf_conntrack_expect_pernet_init(net);
1788 ret = nf_conntrack_acct_pernet_init(net);
1791 ret = nf_conntrack_tstamp_pernet_init(net);
1794 ret = nf_conntrack_ecache_pernet_init(net);
1797 ret = nf_conntrack_helper_pernet_init(net);
1800 ret = nf_conntrack_proto_pernet_init(net);
1806 nf_conntrack_helper_pernet_fini(net);
1808 nf_conntrack_ecache_pernet_fini(net);
1810 nf_conntrack_tstamp_pernet_fini(net);
1812 nf_conntrack_acct_pernet_fini(net);
1814 nf_conntrack_expect_pernet_fini(net);
1816 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1818 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1820 kfree(net->ct.slabname);
1822 free_percpu(net->ct.stat);
1824 free_percpu(net->ct.pcpu_lists);