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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/types.h>
18 #include <linux/netfilter.h>
19 #include <linux/module.h>
20 #include <linux/sched.h>
21 #include <linux/skbuff.h>
22 #include <linux/proc_fs.h>
23 #include <linux/vmalloc.h>
24 #include <linux/stddef.h>
25 #include <linux/slab.h>
26 #include <linux/random.h>
27 #include <linux/jhash.h>
28 #include <linux/err.h>
29 #include <linux/percpu.h>
30 #include <linux/moduleparam.h>
31 #include <linux/notifier.h>
32 #include <linux/kernel.h>
33 #include <linux/netdevice.h>
34 #include <linux/socket.h>
36 #include <linux/nsproxy.h>
37 #include <linux/rculist_nulls.h>
39 #include <net/netfilter/nf_conntrack.h>
40 #include <net/netfilter/nf_conntrack_l3proto.h>
41 #include <net/netfilter/nf_conntrack_l4proto.h>
42 #include <net/netfilter/nf_conntrack_expect.h>
43 #include <net/netfilter/nf_conntrack_helper.h>
44 #include <net/netfilter/nf_conntrack_seqadj.h>
45 #include <net/netfilter/nf_conntrack_core.h>
46 #include <net/netfilter/nf_conntrack_extend.h>
47 #include <net/netfilter/nf_conntrack_acct.h>
48 #include <net/netfilter/nf_conntrack_ecache.h>
49 #include <net/netfilter/nf_conntrack_zones.h>
50 #include <net/netfilter/nf_conntrack_timestamp.h>
51 #include <net/netfilter/nf_conntrack_timeout.h>
52 #include <net/netfilter/nf_conntrack_labels.h>
53 #include <net/netfilter/nf_conntrack_synproxy.h>
54 #include <net/netfilter/nf_nat.h>
55 #include <net/netfilter/nf_nat_core.h>
56 #include <net/netfilter/nf_nat_helper.h>
57 #include <net/netns/hash.h>
59 #define NF_CONNTRACK_VERSION "0.5.0"
61 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
62 enum nf_nat_manip_type manip,
63 const struct nlattr *attr) __read_mostly;
64 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
66 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
67 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
69 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
70 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
72 struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
73 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
75 static __read_mostly struct kmem_cache *nf_conntrack_cachep;
76 static __read_mostly spinlock_t nf_conntrack_locks_all_lock;
77 static __read_mostly seqcount_t nf_conntrack_generation;
78 static __read_mostly DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
79 static __read_mostly bool nf_conntrack_locks_all;
81 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
84 while (unlikely(nf_conntrack_locks_all)) {
86 spin_unlock_wait(&nf_conntrack_locks_all_lock);
90 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
92 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
94 h1 %= CONNTRACK_LOCKS;
95 h2 %= CONNTRACK_LOCKS;
96 spin_unlock(&nf_conntrack_locks[h1]);
98 spin_unlock(&nf_conntrack_locks[h2]);
101 /* return true if we need to recompute hashes (in case hash table was resized) */
102 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
103 unsigned int h2, unsigned int sequence)
105 h1 %= CONNTRACK_LOCKS;
106 h2 %= CONNTRACK_LOCKS;
108 nf_conntrack_lock(&nf_conntrack_locks[h1]);
110 spin_lock_nested(&nf_conntrack_locks[h2],
111 SINGLE_DEPTH_NESTING);
113 nf_conntrack_lock(&nf_conntrack_locks[h2]);
114 spin_lock_nested(&nf_conntrack_locks[h1],
115 SINGLE_DEPTH_NESTING);
117 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
118 nf_conntrack_double_unlock(h1, h2);
124 static void nf_conntrack_all_lock(void)
128 spin_lock(&nf_conntrack_locks_all_lock);
129 nf_conntrack_locks_all = true;
131 for (i = 0; i < CONNTRACK_LOCKS; i++) {
132 spin_unlock_wait(&nf_conntrack_locks[i]);
136 static void nf_conntrack_all_unlock(void)
138 nf_conntrack_locks_all = false;
139 spin_unlock(&nf_conntrack_locks_all_lock);
142 unsigned int nf_conntrack_htable_size __read_mostly;
143 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
145 unsigned int nf_conntrack_max __read_mostly;
146 EXPORT_SYMBOL_GPL(nf_conntrack_max);
148 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
149 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
151 static unsigned int nf_conntrack_hash_rnd __read_mostly;
153 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
154 const struct net *net)
159 get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
161 /* The direction must be ignored, so we hash everything up to the
162 * destination ports (which is a multiple of 4) and treat the last
163 * three bytes manually.
165 seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
166 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
167 return jhash2((u32 *)tuple, n, seed ^
168 (((__force __u16)tuple->dst.u.all << 16) |
169 tuple->dst.protonum));
172 static u32 scale_hash(u32 hash)
174 return reciprocal_scale(hash, nf_conntrack_htable_size);
177 static u32 __hash_conntrack(const struct net *net,
178 const struct nf_conntrack_tuple *tuple,
181 return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
184 static u32 hash_conntrack(const struct net *net,
185 const struct nf_conntrack_tuple *tuple)
187 return scale_hash(hash_conntrack_raw(tuple, net));
191 nf_ct_get_tuple(const struct sk_buff *skb,
193 unsigned int dataoff,
197 struct nf_conntrack_tuple *tuple,
198 const struct nf_conntrack_l3proto *l3proto,
199 const struct nf_conntrack_l4proto *l4proto)
201 memset(tuple, 0, sizeof(*tuple));
203 tuple->src.l3num = l3num;
204 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
207 tuple->dst.protonum = protonum;
208 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
210 return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
212 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
214 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
216 struct net *net, struct nf_conntrack_tuple *tuple)
218 struct nf_conntrack_l3proto *l3proto;
219 struct nf_conntrack_l4proto *l4proto;
220 unsigned int protoff;
226 l3proto = __nf_ct_l3proto_find(l3num);
227 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
228 if (ret != NF_ACCEPT) {
233 l4proto = __nf_ct_l4proto_find(l3num, protonum);
235 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
241 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
244 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
245 const struct nf_conntrack_tuple *orig,
246 const struct nf_conntrack_l3proto *l3proto,
247 const struct nf_conntrack_l4proto *l4proto)
249 memset(inverse, 0, sizeof(*inverse));
251 inverse->src.l3num = orig->src.l3num;
252 if (l3proto->invert_tuple(inverse, orig) == 0)
255 inverse->dst.dir = !orig->dst.dir;
257 inverse->dst.protonum = orig->dst.protonum;
258 return l4proto->invert_tuple(inverse, orig);
260 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
263 clean_from_lists(struct nf_conn *ct)
265 pr_debug("clean_from_lists(%p)\n", ct);
266 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
267 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
269 /* Destroy all pending expectations */
270 nf_ct_remove_expectations(ct);
273 /* must be called with local_bh_disable */
274 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
276 struct ct_pcpu *pcpu;
278 /* add this conntrack to the (per cpu) dying list */
279 ct->cpu = smp_processor_id();
280 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
282 spin_lock(&pcpu->lock);
283 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
285 spin_unlock(&pcpu->lock);
288 /* must be called with local_bh_disable */
289 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
291 struct ct_pcpu *pcpu;
293 /* add this conntrack to the (per cpu) unconfirmed list */
294 ct->cpu = smp_processor_id();
295 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
297 spin_lock(&pcpu->lock);
298 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
300 spin_unlock(&pcpu->lock);
303 /* must be called with local_bh_disable */
304 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
306 struct ct_pcpu *pcpu;
308 /* We overload first tuple to link into unconfirmed or dying list.*/
309 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
311 spin_lock(&pcpu->lock);
312 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
313 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
314 spin_unlock(&pcpu->lock);
317 /* Released via destroy_conntrack() */
318 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
319 const struct nf_conntrack_zone *zone,
322 struct nf_conn *tmpl;
324 tmpl = kzalloc(sizeof(*tmpl), flags);
328 tmpl->status = IPS_TEMPLATE;
329 write_pnet(&tmpl->ct_net, net);
331 if (nf_ct_zone_add(tmpl, flags, zone) < 0)
334 atomic_set(&tmpl->ct_general.use, 0);
341 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
343 void nf_ct_tmpl_free(struct nf_conn *tmpl)
345 nf_ct_ext_destroy(tmpl);
346 nf_ct_ext_free(tmpl);
349 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
352 destroy_conntrack(struct nf_conntrack *nfct)
354 struct nf_conn *ct = (struct nf_conn *)nfct;
355 struct net *net = nf_ct_net(ct);
356 struct nf_conntrack_l4proto *l4proto;
358 pr_debug("destroy_conntrack(%p)\n", ct);
359 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
360 NF_CT_ASSERT(!timer_pending(&ct->timeout));
362 if (unlikely(nf_ct_is_template(ct))) {
367 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
368 if (l4proto->destroy)
369 l4proto->destroy(ct);
374 /* Expectations will have been removed in clean_from_lists,
375 * except TFTP can create an expectation on the first packet,
376 * before connection is in the list, so we need to clean here,
379 nf_ct_remove_expectations(ct);
381 nf_ct_del_from_dying_or_unconfirmed_list(ct);
383 NF_CT_STAT_INC(net, delete);
387 nf_ct_put(ct->master);
389 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
390 nf_conntrack_free(ct);
393 static void nf_ct_delete_from_lists(struct nf_conn *ct)
395 struct net *net = nf_ct_net(ct);
396 unsigned int hash, reply_hash;
397 unsigned int sequence;
399 nf_ct_helper_destroy(ct);
403 sequence = read_seqcount_begin(&nf_conntrack_generation);
404 hash = hash_conntrack(net,
405 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
406 reply_hash = hash_conntrack(net,
407 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
408 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
410 clean_from_lists(ct);
411 nf_conntrack_double_unlock(hash, reply_hash);
413 nf_ct_add_to_dying_list(ct);
415 NF_CT_STAT_INC(net, delete_list);
419 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
421 struct nf_conn_tstamp *tstamp;
423 tstamp = nf_conn_tstamp_find(ct);
424 if (tstamp && tstamp->stop == 0)
425 tstamp->stop = ktime_get_real_ns();
427 if (nf_ct_is_dying(ct))
430 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
431 portid, report) < 0) {
432 /* destroy event was not delivered */
433 nf_ct_delete_from_lists(ct);
434 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
438 nf_conntrack_ecache_work(nf_ct_net(ct));
439 set_bit(IPS_DYING_BIT, &ct->status);
441 nf_ct_delete_from_lists(ct);
445 EXPORT_SYMBOL_GPL(nf_ct_delete);
447 static void death_by_timeout(unsigned long ul_conntrack)
449 nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
453 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
454 const struct nf_conntrack_tuple *tuple,
455 const struct nf_conntrack_zone *zone,
456 const struct net *net)
458 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
460 /* A conntrack can be recreated with the equal tuple,
461 * so we need to check that the conntrack is confirmed
463 return nf_ct_tuple_equal(tuple, &h->tuple) &&
464 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
465 nf_ct_is_confirmed(ct) &&
466 net_eq(net, nf_ct_net(ct));
471 * - Caller must take a reference on returned object
472 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
474 static struct nf_conntrack_tuple_hash *
475 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
476 const struct nf_conntrack_tuple *tuple, u32 hash)
478 struct nf_conntrack_tuple_hash *h;
479 struct hlist_nulls_head *ct_hash;
480 struct hlist_nulls_node *n;
481 unsigned int bucket, sequence;
485 sequence = read_seqcount_begin(&nf_conntrack_generation);
486 bucket = scale_hash(hash);
487 ct_hash = nf_conntrack_hash;
488 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
490 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
491 if (nf_ct_key_equal(h, tuple, zone, net)) {
492 NF_CT_STAT_INC_ATOMIC(net, found);
495 NF_CT_STAT_INC_ATOMIC(net, searched);
498 * if the nulls value we got at the end of this lookup is
499 * not the expected one, we must restart lookup.
500 * We probably met an item that was moved to another chain.
502 if (get_nulls_value(n) != bucket) {
503 NF_CT_STAT_INC_ATOMIC(net, search_restart);
510 /* Find a connection corresponding to a tuple. */
511 static struct nf_conntrack_tuple_hash *
512 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
513 const struct nf_conntrack_tuple *tuple, u32 hash)
515 struct nf_conntrack_tuple_hash *h;
520 h = ____nf_conntrack_find(net, zone, tuple, hash);
522 ct = nf_ct_tuplehash_to_ctrack(h);
523 if (unlikely(nf_ct_is_dying(ct) ||
524 !atomic_inc_not_zero(&ct->ct_general.use)))
527 if (unlikely(!nf_ct_key_equal(h, tuple, zone, net))) {
538 struct nf_conntrack_tuple_hash *
539 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
540 const struct nf_conntrack_tuple *tuple)
542 return __nf_conntrack_find_get(net, zone, tuple,
543 hash_conntrack_raw(tuple, net));
545 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
547 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
549 unsigned int reply_hash)
551 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
552 &nf_conntrack_hash[hash]);
553 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
554 &nf_conntrack_hash[reply_hash]);
558 nf_conntrack_hash_check_insert(struct nf_conn *ct)
560 const struct nf_conntrack_zone *zone;
561 struct net *net = nf_ct_net(ct);
562 unsigned int hash, reply_hash;
563 struct nf_conntrack_tuple_hash *h;
564 struct hlist_nulls_node *n;
565 unsigned int sequence;
567 zone = nf_ct_zone(ct);
571 sequence = read_seqcount_begin(&nf_conntrack_generation);
572 hash = hash_conntrack(net,
573 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
574 reply_hash = hash_conntrack(net,
575 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
576 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
578 /* See if there's one in the list already, including reverse */
579 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
580 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
584 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
585 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
589 add_timer(&ct->timeout);
591 /* The caller holds a reference to this object */
592 atomic_set(&ct->ct_general.use, 2);
593 __nf_conntrack_hash_insert(ct, hash, reply_hash);
594 nf_conntrack_double_unlock(hash, reply_hash);
595 NF_CT_STAT_INC(net, insert);
600 nf_conntrack_double_unlock(hash, reply_hash);
601 NF_CT_STAT_INC(net, insert_failed);
605 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
607 static inline void nf_ct_acct_update(struct nf_conn *ct,
608 enum ip_conntrack_info ctinfo,
611 struct nf_conn_acct *acct;
613 acct = nf_conn_acct_find(ct);
615 struct nf_conn_counter *counter = acct->counter;
617 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
618 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
622 static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
623 const struct nf_conn *loser_ct)
625 struct nf_conn_acct *acct;
627 acct = nf_conn_acct_find(loser_ct);
629 struct nf_conn_counter *counter = acct->counter;
632 /* u32 should be fine since we must have seen one packet. */
633 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
634 nf_ct_acct_update(ct, ctinfo, bytes);
638 /* Resolve race on insertion if this protocol allows this. */
639 static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
640 enum ip_conntrack_info ctinfo,
641 struct nf_conntrack_tuple_hash *h)
643 /* This is the conntrack entry already in hashes that won race. */
644 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
645 struct nf_conntrack_l4proto *l4proto;
647 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
648 if (l4proto->allow_clash &&
649 !nf_ct_is_dying(ct) &&
650 atomic_inc_not_zero(&ct->ct_general.use)) {
651 nf_ct_acct_merge(ct, ctinfo, (struct nf_conn *)skb->nfct);
652 nf_conntrack_put(skb->nfct);
653 /* Assign conntrack already in hashes to this skbuff. Don't
654 * modify skb->nfctinfo to ensure consistent stateful filtering.
656 skb->nfct = &ct->ct_general;
659 NF_CT_STAT_INC(net, drop);
663 /* Confirm a connection given skb; places it in hash table */
665 __nf_conntrack_confirm(struct sk_buff *skb)
667 const struct nf_conntrack_zone *zone;
668 unsigned int hash, reply_hash;
669 struct nf_conntrack_tuple_hash *h;
671 struct nf_conn_help *help;
672 struct nf_conn_tstamp *tstamp;
673 struct hlist_nulls_node *n;
674 enum ip_conntrack_info ctinfo;
676 unsigned int sequence;
679 ct = nf_ct_get(skb, &ctinfo);
682 /* ipt_REJECT uses nf_conntrack_attach to attach related
683 ICMP/TCP RST packets in other direction. Actual packet
684 which created connection will be IP_CT_NEW or for an
685 expected connection, IP_CT_RELATED. */
686 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
689 zone = nf_ct_zone(ct);
693 sequence = read_seqcount_begin(&nf_conntrack_generation);
694 /* reuse the hash saved before */
695 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
696 hash = scale_hash(hash);
697 reply_hash = hash_conntrack(net,
698 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
700 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
702 /* We're not in hash table, and we refuse to set up related
703 * connections for unconfirmed conns. But packet copies and
704 * REJECT will give spurious warnings here.
706 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
708 /* No external references means no one else could have
711 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
712 pr_debug("Confirming conntrack %p\n", ct);
713 /* We have to check the DYING flag after unlink to prevent
714 * a race against nf_ct_get_next_corpse() possibly called from
715 * user context, else we insert an already 'dead' hash, blocking
716 * further use of that particular connection -JM.
718 nf_ct_del_from_dying_or_unconfirmed_list(ct);
720 if (unlikely(nf_ct_is_dying(ct))) {
721 nf_ct_add_to_dying_list(ct);
725 /* See if there's one in the list already, including reverse:
726 NAT could have grabbed it without realizing, since we're
727 not in the hash. If there is, we lost race. */
728 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
729 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
733 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
734 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
738 /* Timer relative to confirmation time, not original
739 setting time, otherwise we'd get timer wrap in
740 weird delay cases. */
741 ct->timeout.expires += jiffies;
742 add_timer(&ct->timeout);
743 atomic_inc(&ct->ct_general.use);
744 ct->status |= IPS_CONFIRMED;
746 /* set conntrack timestamp, if enabled. */
747 tstamp = nf_conn_tstamp_find(ct);
749 if (skb->tstamp.tv64 == 0)
750 __net_timestamp(skb);
752 tstamp->start = ktime_to_ns(skb->tstamp);
754 /* Since the lookup is lockless, hash insertion must be done after
755 * starting the timer and setting the CONFIRMED bit. The RCU barriers
756 * guarantee that no other CPU can find the conntrack before the above
757 * stores are visible.
759 __nf_conntrack_hash_insert(ct, hash, reply_hash);
760 nf_conntrack_double_unlock(hash, reply_hash);
761 NF_CT_STAT_INC(net, insert);
764 help = nfct_help(ct);
765 if (help && help->helper)
766 nf_conntrack_event_cache(IPCT_HELPER, ct);
768 nf_conntrack_event_cache(master_ct(ct) ?
769 IPCT_RELATED : IPCT_NEW, ct);
773 nf_ct_add_to_dying_list(ct);
774 ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
776 nf_conntrack_double_unlock(hash, reply_hash);
777 NF_CT_STAT_INC(net, insert_failed);
781 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
783 /* Returns true if a connection correspondings to the tuple (required
786 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
787 const struct nf_conn *ignored_conntrack)
789 struct net *net = nf_ct_net(ignored_conntrack);
790 const struct nf_conntrack_zone *zone;
791 struct nf_conntrack_tuple_hash *h;
792 struct hlist_nulls_head *ct_hash;
793 unsigned int hash, sequence;
794 struct hlist_nulls_node *n;
797 zone = nf_ct_zone(ignored_conntrack);
801 sequence = read_seqcount_begin(&nf_conntrack_generation);
802 hash = hash_conntrack(net, tuple);
803 ct_hash = nf_conntrack_hash;
804 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
806 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
807 ct = nf_ct_tuplehash_to_ctrack(h);
808 if (ct != ignored_conntrack &&
809 nf_ct_key_equal(h, tuple, zone, net)) {
810 NF_CT_STAT_INC_ATOMIC(net, found);
814 NF_CT_STAT_INC_ATOMIC(net, searched);
820 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
822 #define NF_CT_EVICTION_RANGE 8
824 /* There's a small race here where we may free a just-assured
825 connection. Too bad: we're in trouble anyway. */
826 static noinline int early_drop(struct net *net, unsigned int _hash)
828 /* Use oldest entry, which is roughly LRU */
829 struct nf_conntrack_tuple_hash *h;
831 struct hlist_nulls_node *n;
832 unsigned int i, hash, sequence;
833 struct nf_conn *ct = NULL;
841 sequence = read_seqcount_begin(&nf_conntrack_generation);
842 for (; i < NF_CT_EVICTION_RANGE; i++) {
843 hash = scale_hash(_hash++);
844 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
845 nf_conntrack_lock(lockp);
846 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
850 hlist_nulls_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
852 tmp = nf_ct_tuplehash_to_ctrack(h);
854 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
855 !net_eq(nf_ct_net(tmp), net) ||
859 if (atomic_inc_not_zero(&tmp->ct_general.use)) {
875 /* kill only if in same netns -- might have moved due to
876 * SLAB_DESTROY_BY_RCU rules
878 if (net_eq(nf_ct_net(ct), net) && del_timer(&ct->timeout)) {
879 if (nf_ct_delete(ct, 0, 0)) {
880 NF_CT_STAT_INC_ATOMIC(net, early_drop);
889 static struct nf_conn *
890 __nf_conntrack_alloc(struct net *net,
891 const struct nf_conntrack_zone *zone,
892 const struct nf_conntrack_tuple *orig,
893 const struct nf_conntrack_tuple *repl,
898 /* We don't want any race condition at early drop stage */
899 atomic_inc(&net->ct.count);
901 if (nf_conntrack_max &&
902 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
903 if (!early_drop(net, hash)) {
904 atomic_dec(&net->ct.count);
905 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
906 return ERR_PTR(-ENOMEM);
911 * Do not use kmem_cache_zalloc(), as this cache uses
912 * SLAB_DESTROY_BY_RCU.
914 ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
918 spin_lock_init(&ct->lock);
919 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
920 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
921 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
922 /* save hash for reusing when confirming */
923 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
925 /* Don't set timer yet: wait for confirmation */
926 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
927 write_pnet(&ct->ct_net, net);
928 memset(&ct->__nfct_init_offset[0], 0,
929 offsetof(struct nf_conn, proto) -
930 offsetof(struct nf_conn, __nfct_init_offset[0]));
932 if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
935 /* Because we use RCU lookups, we set ct_general.use to zero before
936 * this is inserted in any list.
938 atomic_set(&ct->ct_general.use, 0);
941 kmem_cache_free(nf_conntrack_cachep, ct);
943 atomic_dec(&net->ct.count);
944 return ERR_PTR(-ENOMEM);
947 struct nf_conn *nf_conntrack_alloc(struct net *net,
948 const struct nf_conntrack_zone *zone,
949 const struct nf_conntrack_tuple *orig,
950 const struct nf_conntrack_tuple *repl,
953 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
955 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
957 void nf_conntrack_free(struct nf_conn *ct)
959 struct net *net = nf_ct_net(ct);
961 /* A freed object has refcnt == 0, that's
962 * the golden rule for SLAB_DESTROY_BY_RCU
964 NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
966 nf_ct_ext_destroy(ct);
968 kmem_cache_free(nf_conntrack_cachep, ct);
969 smp_mb__before_atomic();
970 atomic_dec(&net->ct.count);
972 EXPORT_SYMBOL_GPL(nf_conntrack_free);
975 /* Allocate a new conntrack: we return -ENOMEM if classification
976 failed due to stress. Otherwise it really is unclassifiable. */
977 static struct nf_conntrack_tuple_hash *
978 init_conntrack(struct net *net, struct nf_conn *tmpl,
979 const struct nf_conntrack_tuple *tuple,
980 struct nf_conntrack_l3proto *l3proto,
981 struct nf_conntrack_l4proto *l4proto,
983 unsigned int dataoff, u32 hash)
986 struct nf_conn_help *help;
987 struct nf_conntrack_tuple repl_tuple;
988 struct nf_conntrack_ecache *ecache;
989 struct nf_conntrack_expect *exp = NULL;
990 const struct nf_conntrack_zone *zone;
991 struct nf_conn_timeout *timeout_ext;
992 struct nf_conntrack_zone tmp;
993 unsigned int *timeouts;
995 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
996 pr_debug("Can't invert tuple.\n");
1000 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1001 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1004 return (struct nf_conntrack_tuple_hash *)ct;
1006 if (tmpl && nfct_synproxy(tmpl)) {
1007 nfct_seqadj_ext_add(ct);
1008 nfct_synproxy_ext_add(ct);
1011 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1013 timeouts = nf_ct_timeout_data(timeout_ext);
1014 if (unlikely(!timeouts))
1015 timeouts = l4proto->get_timeouts(net);
1017 timeouts = l4proto->get_timeouts(net);
1020 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
1021 nf_conntrack_free(ct);
1022 pr_debug("can't track with proto module\n");
1027 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1030 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1031 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1032 nf_ct_labels_ext_add(ct);
1034 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1035 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1036 ecache ? ecache->expmask : 0,
1040 if (net->ct.expect_count) {
1041 spin_lock(&nf_conntrack_expect_lock);
1042 exp = nf_ct_find_expectation(net, zone, tuple);
1044 pr_debug("expectation arrives ct=%p exp=%p\n",
1046 /* Welcome, Mr. Bond. We've been expecting you... */
1047 __set_bit(IPS_EXPECTED_BIT, &ct->status);
1048 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1049 ct->master = exp->master;
1051 help = nf_ct_helper_ext_add(ct, exp->helper,
1054 rcu_assign_pointer(help->helper, exp->helper);
1057 #ifdef CONFIG_NF_CONNTRACK_MARK
1058 ct->mark = exp->master->mark;
1060 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1061 ct->secmark = exp->master->secmark;
1063 NF_CT_STAT_INC(net, expect_new);
1065 spin_unlock(&nf_conntrack_expect_lock);
1068 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1069 NF_CT_STAT_INC(net, new);
1072 /* Now it is inserted into the unconfirmed list, bump refcount */
1073 nf_conntrack_get(&ct->ct_general);
1074 nf_ct_add_to_unconfirmed_list(ct);
1080 exp->expectfn(ct, exp);
1081 nf_ct_expect_put(exp);
1084 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1087 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1088 static inline struct nf_conn *
1089 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1090 struct sk_buff *skb,
1091 unsigned int dataoff,
1094 struct nf_conntrack_l3proto *l3proto,
1095 struct nf_conntrack_l4proto *l4proto,
1097 enum ip_conntrack_info *ctinfo)
1099 const struct nf_conntrack_zone *zone;
1100 struct nf_conntrack_tuple tuple;
1101 struct nf_conntrack_tuple_hash *h;
1102 struct nf_conntrack_zone tmp;
1106 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1107 dataoff, l3num, protonum, net, &tuple, l3proto,
1109 pr_debug("Can't get tuple\n");
1113 /* look for tuple match */
1114 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1115 hash = hash_conntrack_raw(&tuple, net);
1116 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1118 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1119 skb, dataoff, hash);
1125 ct = nf_ct_tuplehash_to_ctrack(h);
1127 /* It exists; we have (non-exclusive) reference. */
1128 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1129 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1130 /* Please set reply bit if this packet OK */
1133 /* Once we've had two way comms, always ESTABLISHED. */
1134 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1135 pr_debug("normal packet for %p\n", ct);
1136 *ctinfo = IP_CT_ESTABLISHED;
1137 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1138 pr_debug("related packet for %p\n", ct);
1139 *ctinfo = IP_CT_RELATED;
1141 pr_debug("new packet for %p\n", ct);
1142 *ctinfo = IP_CT_NEW;
1146 skb->nfct = &ct->ct_general;
1147 skb->nfctinfo = *ctinfo;
1152 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1153 struct sk_buff *skb)
1155 struct nf_conn *ct, *tmpl = NULL;
1156 enum ip_conntrack_info ctinfo;
1157 struct nf_conntrack_l3proto *l3proto;
1158 struct nf_conntrack_l4proto *l4proto;
1159 unsigned int *timeouts;
1160 unsigned int dataoff;
1166 /* Previously seen (loopback or untracked)? Ignore. */
1167 tmpl = (struct nf_conn *)skb->nfct;
1168 if (!nf_ct_is_template(tmpl)) {
1169 NF_CT_STAT_INC_ATOMIC(net, ignore);
1175 /* rcu_read_lock()ed by nf_hook_slow */
1176 l3proto = __nf_ct_l3proto_find(pf);
1177 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1178 &dataoff, &protonum);
1180 pr_debug("not prepared to track yet or error occurred\n");
1181 NF_CT_STAT_INC_ATOMIC(net, error);
1182 NF_CT_STAT_INC_ATOMIC(net, invalid);
1187 l4proto = __nf_ct_l4proto_find(pf, protonum);
1189 /* It may be an special packet, error, unclean...
1190 * inverse of the return code tells to the netfilter
1191 * core what to do with the packet. */
1192 if (l4proto->error != NULL) {
1193 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1196 NF_CT_STAT_INC_ATOMIC(net, error);
1197 NF_CT_STAT_INC_ATOMIC(net, invalid);
1201 /* ICMP[v6] protocol trackers may assign one conntrack. */
1206 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1207 l3proto, l4proto, &set_reply, &ctinfo);
1209 /* Not valid part of a connection */
1210 NF_CT_STAT_INC_ATOMIC(net, invalid);
1216 /* Too stressed to deal. */
1217 NF_CT_STAT_INC_ATOMIC(net, drop);
1222 NF_CT_ASSERT(skb->nfct);
1224 /* Decide what timeout policy we want to apply to this flow. */
1225 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1227 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1229 /* Invalid: inverse of the return code tells
1230 * the netfilter core what to do */
1231 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1232 nf_conntrack_put(skb->nfct);
1234 NF_CT_STAT_INC_ATOMIC(net, invalid);
1235 if (ret == -NF_DROP)
1236 NF_CT_STAT_INC_ATOMIC(net, drop);
1241 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1242 nf_conntrack_event_cache(IPCT_REPLY, ct);
1245 /* Special case: we have to repeat this hook, assign the
1246 * template again to this packet. We assume that this packet
1247 * has no conntrack assigned. This is used by nf_ct_tcp. */
1248 if (ret == NF_REPEAT)
1249 skb->nfct = (struct nf_conntrack *)tmpl;
1256 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1258 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1259 const struct nf_conntrack_tuple *orig)
1264 ret = nf_ct_invert_tuple(inverse, orig,
1265 __nf_ct_l3proto_find(orig->src.l3num),
1266 __nf_ct_l4proto_find(orig->src.l3num,
1267 orig->dst.protonum));
1271 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1273 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1274 implicitly racy: see __nf_conntrack_confirm */
1275 void nf_conntrack_alter_reply(struct nf_conn *ct,
1276 const struct nf_conntrack_tuple *newreply)
1278 struct nf_conn_help *help = nfct_help(ct);
1280 /* Should be unconfirmed, so not in hash table yet */
1281 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1283 pr_debug("Altering reply tuple of %p to ", ct);
1284 nf_ct_dump_tuple(newreply);
1286 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1287 if (ct->master || (help && !hlist_empty(&help->expectations)))
1291 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1294 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1296 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1297 void __nf_ct_refresh_acct(struct nf_conn *ct,
1298 enum ip_conntrack_info ctinfo,
1299 const struct sk_buff *skb,
1300 unsigned long extra_jiffies,
1303 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1306 /* Only update if this is not a fixed timeout */
1307 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1310 /* If not in hash table, timer will not be active yet */
1311 if (!nf_ct_is_confirmed(ct)) {
1312 ct->timeout.expires = extra_jiffies;
1314 unsigned long newtime = jiffies + extra_jiffies;
1316 /* Only update the timeout if the new timeout is at least
1317 HZ jiffies from the old timeout. Need del_timer for race
1318 avoidance (may already be dying). */
1319 if (newtime - ct->timeout.expires >= HZ)
1320 mod_timer_pending(&ct->timeout, newtime);
1325 nf_ct_acct_update(ct, ctinfo, skb->len);
1327 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1329 bool __nf_ct_kill_acct(struct nf_conn *ct,
1330 enum ip_conntrack_info ctinfo,
1331 const struct sk_buff *skb,
1335 nf_ct_acct_update(ct, ctinfo, skb->len);
1337 if (del_timer(&ct->timeout)) {
1338 ct->timeout.function((unsigned long)ct);
1343 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1345 #ifdef CONFIG_NF_CONNTRACK_ZONES
1346 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1347 .len = sizeof(struct nf_conntrack_zone),
1348 .align = __alignof__(struct nf_conntrack_zone),
1349 .id = NF_CT_EXT_ZONE,
1353 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1355 #include <linux/netfilter/nfnetlink.h>
1356 #include <linux/netfilter/nfnetlink_conntrack.h>
1357 #include <linux/mutex.h>
1359 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1360 * in ip_conntrack_core, since we don't want the protocols to autoload
1361 * or depend on ctnetlink */
1362 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1363 const struct nf_conntrack_tuple *tuple)
1365 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1366 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1367 goto nla_put_failure;
1373 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1375 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1376 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1377 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1379 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1381 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1382 struct nf_conntrack_tuple *t)
1384 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1387 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1388 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1392 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1394 int nf_ct_port_nlattr_tuple_size(void)
1396 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1398 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1401 /* Used by ipt_REJECT and ip6t_REJECT. */
1402 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1405 enum ip_conntrack_info ctinfo;
1407 /* This ICMP is in reverse direction to the packet which caused it */
1408 ct = nf_ct_get(skb, &ctinfo);
1409 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1410 ctinfo = IP_CT_RELATED_REPLY;
1412 ctinfo = IP_CT_RELATED;
1414 /* Attach to new skbuff, and increment count */
1415 nskb->nfct = &ct->ct_general;
1416 nskb->nfctinfo = ctinfo;
1417 nf_conntrack_get(nskb->nfct);
1420 /* Bring out ya dead! */
1421 static struct nf_conn *
1422 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1423 void *data, unsigned int *bucket)
1425 struct nf_conntrack_tuple_hash *h;
1427 struct hlist_nulls_node *n;
1431 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1432 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1434 nf_conntrack_lock(lockp);
1435 if (*bucket < nf_conntrack_htable_size) {
1436 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
1437 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1439 ct = nf_ct_tuplehash_to_ctrack(h);
1440 if (net_eq(nf_ct_net(ct), net) &&
1450 for_each_possible_cpu(cpu) {
1451 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1453 spin_lock_bh(&pcpu->lock);
1454 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1455 ct = nf_ct_tuplehash_to_ctrack(h);
1457 set_bit(IPS_DYING_BIT, &ct->status);
1459 spin_unlock_bh(&pcpu->lock);
1464 atomic_inc(&ct->ct_general.use);
1470 void nf_ct_iterate_cleanup(struct net *net,
1471 int (*iter)(struct nf_conn *i, void *data),
1472 void *data, u32 portid, int report)
1475 unsigned int bucket = 0;
1479 if (atomic_read(&net->ct.count) == 0)
1482 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1483 /* Time to push up daises... */
1484 if (del_timer(&ct->timeout))
1485 nf_ct_delete(ct, portid, report);
1487 /* ... else the timer will get him soon. */
1493 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1495 static int kill_all(struct nf_conn *i, void *data)
1500 void nf_ct_free_hashtable(void *hash, unsigned int size)
1502 if (is_vmalloc_addr(hash))
1505 free_pages((unsigned long)hash,
1506 get_order(sizeof(struct hlist_head) * size));
1508 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1510 static int untrack_refs(void)
1514 for_each_possible_cpu(cpu) {
1515 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1517 cnt += atomic_read(&ct->ct_general.use) - 1;
1522 void nf_conntrack_cleanup_start(void)
1524 RCU_INIT_POINTER(ip_ct_attach, NULL);
1527 void nf_conntrack_cleanup_end(void)
1529 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1530 while (untrack_refs() > 0)
1533 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1535 #ifdef CONFIG_NF_CONNTRACK_ZONES
1536 nf_ct_extend_unregister(&nf_ct_zone_extend);
1538 nf_conntrack_proto_fini();
1539 nf_conntrack_seqadj_fini();
1540 nf_conntrack_labels_fini();
1541 nf_conntrack_helper_fini();
1542 nf_conntrack_timeout_fini();
1543 nf_conntrack_ecache_fini();
1544 nf_conntrack_tstamp_fini();
1545 nf_conntrack_acct_fini();
1546 nf_conntrack_expect_fini();
1550 * Mishearing the voices in his head, our hero wonders how he's
1551 * supposed to kill the mall.
1553 void nf_conntrack_cleanup_net(struct net *net)
1557 list_add(&net->exit_list, &single);
1558 nf_conntrack_cleanup_net_list(&single);
1561 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1567 * This makes sure all current packets have passed through
1568 * netfilter framework. Roll on, two-stage module
1574 list_for_each_entry(net, net_exit_list, exit_list) {
1575 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1576 if (atomic_read(&net->ct.count) != 0)
1581 goto i_see_dead_people;
1584 list_for_each_entry(net, net_exit_list, exit_list) {
1585 nf_conntrack_proto_pernet_fini(net);
1586 nf_conntrack_helper_pernet_fini(net);
1587 nf_conntrack_ecache_pernet_fini(net);
1588 nf_conntrack_tstamp_pernet_fini(net);
1589 nf_conntrack_acct_pernet_fini(net);
1590 nf_conntrack_expect_pernet_fini(net);
1591 free_percpu(net->ct.stat);
1592 free_percpu(net->ct.pcpu_lists);
1596 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1598 struct hlist_nulls_head *hash;
1599 unsigned int nr_slots, i;
1602 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1603 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1604 sz = nr_slots * sizeof(struct hlist_nulls_head);
1605 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1611 for (i = 0; i < nr_slots; i++)
1612 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1616 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1618 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1621 unsigned int hashsize, old_size;
1622 struct hlist_nulls_head *hash, *old_hash;
1623 struct nf_conntrack_tuple_hash *h;
1626 if (current->nsproxy->net_ns != &init_net)
1629 /* On boot, we can set this without any fancy locking. */
1630 if (!nf_conntrack_htable_size)
1631 return param_set_uint(val, kp);
1633 rc = kstrtouint(val, 0, &hashsize);
1639 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1644 nf_conntrack_all_lock();
1645 write_seqcount_begin(&nf_conntrack_generation);
1647 /* Lookups in the old hash might happen in parallel, which means we
1648 * might get false negatives during connection lookup. New connections
1649 * created because of a false negative won't make it into the hash
1650 * though since that required taking the locks.
1653 for (i = 0; i < nf_conntrack_htable_size; i++) {
1654 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
1655 h = hlist_nulls_entry(nf_conntrack_hash[i].first,
1656 struct nf_conntrack_tuple_hash, hnnode);
1657 ct = nf_ct_tuplehash_to_ctrack(h);
1658 hlist_nulls_del_rcu(&h->hnnode);
1659 bucket = __hash_conntrack(nf_ct_net(ct),
1660 &h->tuple, hashsize);
1661 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1664 old_size = nf_conntrack_htable_size;
1665 old_hash = nf_conntrack_hash;
1667 nf_conntrack_hash = hash;
1668 nf_conntrack_htable_size = hashsize;
1670 write_seqcount_end(&nf_conntrack_generation);
1671 nf_conntrack_all_unlock();
1675 nf_ct_free_hashtable(old_hash, old_size);
1678 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1680 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1681 &nf_conntrack_htable_size, 0600);
1683 void nf_ct_untracked_status_or(unsigned long bits)
1687 for_each_possible_cpu(cpu)
1688 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1690 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1692 int nf_conntrack_init_start(void)
1698 seqcount_init(&nf_conntrack_generation);
1700 for (i = 0; i < CONNTRACK_LOCKS; i++)
1701 spin_lock_init(&nf_conntrack_locks[i]);
1703 if (!nf_conntrack_htable_size) {
1704 /* Idea from tcp.c: use 1/16384 of memory.
1705 * On i386: 32MB machine has 512 buckets.
1706 * >= 1GB machines have 16384 buckets.
1707 * >= 4GB machines have 65536 buckets.
1709 nf_conntrack_htable_size
1710 = (((totalram_pages << PAGE_SHIFT) / 16384)
1711 / sizeof(struct hlist_head));
1712 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1713 nf_conntrack_htable_size = 65536;
1714 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1715 nf_conntrack_htable_size = 16384;
1716 if (nf_conntrack_htable_size < 32)
1717 nf_conntrack_htable_size = 32;
1719 /* Use a max. factor of four by default to get the same max as
1720 * with the old struct list_heads. When a table size is given
1721 * we use the old value of 8 to avoid reducing the max.
1726 nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
1727 if (!nf_conntrack_hash)
1730 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1732 nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1733 sizeof(struct nf_conn), 0,
1734 SLAB_DESTROY_BY_RCU, NULL);
1735 if (!nf_conntrack_cachep)
1738 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1739 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1742 ret = nf_conntrack_expect_init();
1746 ret = nf_conntrack_acct_init();
1750 ret = nf_conntrack_tstamp_init();
1754 ret = nf_conntrack_ecache_init();
1758 ret = nf_conntrack_timeout_init();
1762 ret = nf_conntrack_helper_init();
1766 ret = nf_conntrack_labels_init();
1770 ret = nf_conntrack_seqadj_init();
1774 #ifdef CONFIG_NF_CONNTRACK_ZONES
1775 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1779 ret = nf_conntrack_proto_init();
1783 /* Set up fake conntrack: to never be deleted, not in any hashes */
1784 for_each_possible_cpu(cpu) {
1785 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1786 write_pnet(&ct->ct_net, &init_net);
1787 atomic_set(&ct->ct_general.use, 1);
1789 /* - and look it like as a confirmed connection */
1790 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1794 #ifdef CONFIG_NF_CONNTRACK_ZONES
1795 nf_ct_extend_unregister(&nf_ct_zone_extend);
1798 nf_conntrack_seqadj_fini();
1800 nf_conntrack_labels_fini();
1802 nf_conntrack_helper_fini();
1804 nf_conntrack_timeout_fini();
1806 nf_conntrack_ecache_fini();
1808 nf_conntrack_tstamp_fini();
1810 nf_conntrack_acct_fini();
1812 nf_conntrack_expect_fini();
1814 kmem_cache_destroy(nf_conntrack_cachep);
1816 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1820 void nf_conntrack_init_end(void)
1822 /* For use by REJECT target */
1823 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1824 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1828 * We need to use special "null" values, not used in hash table
1830 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1831 #define DYING_NULLS_VAL ((1<<30)+1)
1832 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1834 int nf_conntrack_init_net(struct net *net)
1839 atomic_set(&net->ct.count, 0);
1841 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1842 if (!net->ct.pcpu_lists)
1845 for_each_possible_cpu(cpu) {
1846 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1848 spin_lock_init(&pcpu->lock);
1849 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1850 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1853 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1855 goto err_pcpu_lists;
1857 ret = nf_conntrack_expect_pernet_init(net);
1860 ret = nf_conntrack_acct_pernet_init(net);
1863 ret = nf_conntrack_tstamp_pernet_init(net);
1866 ret = nf_conntrack_ecache_pernet_init(net);
1869 ret = nf_conntrack_helper_pernet_init(net);
1872 ret = nf_conntrack_proto_pernet_init(net);
1878 nf_conntrack_helper_pernet_fini(net);
1880 nf_conntrack_ecache_pernet_fini(net);
1882 nf_conntrack_tstamp_pernet_fini(net);
1884 nf_conntrack_acct_pernet_fini(net);
1886 nf_conntrack_expect_pernet_fini(net);
1888 free_percpu(net->ct.stat);
1890 free_percpu(net->ct.pcpu_lists);