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)) {
88 * Order the 'nf_conntrack_locks_all' load vs. the
89 * spin_unlock_wait() loads below, to ensure
90 * that 'nf_conntrack_locks_all_lock' is indeed held:
92 smp_rmb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
93 spin_unlock_wait(&nf_conntrack_locks_all_lock);
97 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
99 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
101 h1 %= CONNTRACK_LOCKS;
102 h2 %= CONNTRACK_LOCKS;
103 spin_unlock(&nf_conntrack_locks[h1]);
105 spin_unlock(&nf_conntrack_locks[h2]);
108 /* return true if we need to recompute hashes (in case hash table was resized) */
109 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
110 unsigned int h2, unsigned int sequence)
112 h1 %= CONNTRACK_LOCKS;
113 h2 %= CONNTRACK_LOCKS;
115 nf_conntrack_lock(&nf_conntrack_locks[h1]);
117 spin_lock_nested(&nf_conntrack_locks[h2],
118 SINGLE_DEPTH_NESTING);
120 nf_conntrack_lock(&nf_conntrack_locks[h2]);
121 spin_lock_nested(&nf_conntrack_locks[h1],
122 SINGLE_DEPTH_NESTING);
124 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
125 nf_conntrack_double_unlock(h1, h2);
131 static void nf_conntrack_all_lock(void)
135 spin_lock(&nf_conntrack_locks_all_lock);
136 nf_conntrack_locks_all = true;
139 * Order the above store of 'nf_conntrack_locks_all' against
140 * the spin_unlock_wait() loads below, such that if
141 * nf_conntrack_lock() observes 'nf_conntrack_locks_all'
142 * we must observe nf_conntrack_locks[] held:
144 smp_mb(); /* spin_lock(&nf_conntrack_locks_all_lock) */
146 for (i = 0; i < CONNTRACK_LOCKS; i++) {
147 spin_unlock_wait(&nf_conntrack_locks[i]);
151 static void nf_conntrack_all_unlock(void)
154 * All prior stores must be complete before we clear
155 * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
156 * might observe the false value but not the entire
159 smp_store_release(&nf_conntrack_locks_all, false);
160 spin_unlock(&nf_conntrack_locks_all_lock);
163 unsigned int nf_conntrack_htable_size __read_mostly;
164 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
166 unsigned int nf_conntrack_max __read_mostly;
167 EXPORT_SYMBOL_GPL(nf_conntrack_max);
169 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
170 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
172 static unsigned int nf_conntrack_hash_rnd __read_mostly;
174 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
175 const struct net *net)
180 get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
182 /* The direction must be ignored, so we hash everything up to the
183 * destination ports (which is a multiple of 4) and treat the last
184 * three bytes manually.
186 seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
187 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
188 return jhash2((u32 *)tuple, n, seed ^
189 (((__force __u16)tuple->dst.u.all << 16) |
190 tuple->dst.protonum));
193 static u32 scale_hash(u32 hash)
195 return reciprocal_scale(hash, nf_conntrack_htable_size);
198 static u32 __hash_conntrack(const struct net *net,
199 const struct nf_conntrack_tuple *tuple,
202 return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
205 static u32 hash_conntrack(const struct net *net,
206 const struct nf_conntrack_tuple *tuple)
208 return scale_hash(hash_conntrack_raw(tuple, net));
212 nf_ct_get_tuple(const struct sk_buff *skb,
214 unsigned int dataoff,
218 struct nf_conntrack_tuple *tuple,
219 const struct nf_conntrack_l3proto *l3proto,
220 const struct nf_conntrack_l4proto *l4proto)
222 memset(tuple, 0, sizeof(*tuple));
224 tuple->src.l3num = l3num;
225 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
228 tuple->dst.protonum = protonum;
229 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
231 return l4proto->pkt_to_tuple(skb, dataoff, net, tuple);
233 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
235 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
237 struct net *net, struct nf_conntrack_tuple *tuple)
239 struct nf_conntrack_l3proto *l3proto;
240 struct nf_conntrack_l4proto *l4proto;
241 unsigned int protoff;
247 l3proto = __nf_ct_l3proto_find(l3num);
248 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
249 if (ret != NF_ACCEPT) {
254 l4proto = __nf_ct_l4proto_find(l3num, protonum);
256 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
262 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
265 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
266 const struct nf_conntrack_tuple *orig,
267 const struct nf_conntrack_l3proto *l3proto,
268 const struct nf_conntrack_l4proto *l4proto)
270 memset(inverse, 0, sizeof(*inverse));
272 inverse->src.l3num = orig->src.l3num;
273 if (l3proto->invert_tuple(inverse, orig) == 0)
276 inverse->dst.dir = !orig->dst.dir;
278 inverse->dst.protonum = orig->dst.protonum;
279 return l4proto->invert_tuple(inverse, orig);
281 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
284 clean_from_lists(struct nf_conn *ct)
286 pr_debug("clean_from_lists(%p)\n", ct);
287 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
288 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
290 /* Destroy all pending expectations */
291 nf_ct_remove_expectations(ct);
294 /* must be called with local_bh_disable */
295 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
297 struct ct_pcpu *pcpu;
299 /* add this conntrack to the (per cpu) dying list */
300 ct->cpu = smp_processor_id();
301 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
303 spin_lock(&pcpu->lock);
304 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
306 spin_unlock(&pcpu->lock);
309 /* must be called with local_bh_disable */
310 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
312 struct ct_pcpu *pcpu;
314 /* add this conntrack to the (per cpu) unconfirmed list */
315 ct->cpu = smp_processor_id();
316 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
318 spin_lock(&pcpu->lock);
319 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
321 spin_unlock(&pcpu->lock);
324 /* must be called with local_bh_disable */
325 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
327 struct ct_pcpu *pcpu;
329 /* We overload first tuple to link into unconfirmed or dying list.*/
330 pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
332 spin_lock(&pcpu->lock);
333 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
334 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
335 spin_unlock(&pcpu->lock);
338 /* Released via destroy_conntrack() */
339 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
340 const struct nf_conntrack_zone *zone,
343 struct nf_conn *tmpl;
345 tmpl = kzalloc(sizeof(*tmpl), flags);
349 tmpl->status = IPS_TEMPLATE;
350 write_pnet(&tmpl->ct_net, net);
352 if (nf_ct_zone_add(tmpl, flags, zone) < 0)
355 atomic_set(&tmpl->ct_general.use, 0);
362 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
364 void nf_ct_tmpl_free(struct nf_conn *tmpl)
366 nf_ct_ext_destroy(tmpl);
367 nf_ct_ext_free(tmpl);
370 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
373 destroy_conntrack(struct nf_conntrack *nfct)
375 struct nf_conn *ct = (struct nf_conn *)nfct;
376 struct net *net = nf_ct_net(ct);
377 struct nf_conntrack_l4proto *l4proto;
379 pr_debug("destroy_conntrack(%p)\n", ct);
380 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
381 NF_CT_ASSERT(!timer_pending(&ct->timeout));
383 if (unlikely(nf_ct_is_template(ct))) {
388 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
389 if (l4proto->destroy)
390 l4proto->destroy(ct);
395 /* Expectations will have been removed in clean_from_lists,
396 * except TFTP can create an expectation on the first packet,
397 * before connection is in the list, so we need to clean here,
400 nf_ct_remove_expectations(ct);
402 nf_ct_del_from_dying_or_unconfirmed_list(ct);
404 NF_CT_STAT_INC(net, delete);
408 nf_ct_put(ct->master);
410 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
411 nf_conntrack_free(ct);
414 static void nf_ct_delete_from_lists(struct nf_conn *ct)
416 struct net *net = nf_ct_net(ct);
417 unsigned int hash, reply_hash;
418 unsigned int sequence;
420 nf_ct_helper_destroy(ct);
424 sequence = read_seqcount_begin(&nf_conntrack_generation);
425 hash = hash_conntrack(net,
426 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
427 reply_hash = hash_conntrack(net,
428 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
429 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
431 clean_from_lists(ct);
432 nf_conntrack_double_unlock(hash, reply_hash);
434 nf_ct_add_to_dying_list(ct);
436 NF_CT_STAT_INC(net, delete_list);
440 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
442 struct nf_conn_tstamp *tstamp;
444 tstamp = nf_conn_tstamp_find(ct);
445 if (tstamp && tstamp->stop == 0)
446 tstamp->stop = ktime_get_real_ns();
448 if (nf_ct_is_dying(ct))
451 if (nf_conntrack_event_report(IPCT_DESTROY, ct,
452 portid, report) < 0) {
453 /* destroy event was not delivered */
454 nf_ct_delete_from_lists(ct);
455 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
459 nf_conntrack_ecache_work(nf_ct_net(ct));
460 set_bit(IPS_DYING_BIT, &ct->status);
462 nf_ct_delete_from_lists(ct);
466 EXPORT_SYMBOL_GPL(nf_ct_delete);
468 static void death_by_timeout(unsigned long ul_conntrack)
470 nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
474 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
475 const struct nf_conntrack_tuple *tuple,
476 const struct nf_conntrack_zone *zone,
477 const struct net *net)
479 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
481 /* A conntrack can be recreated with the equal tuple,
482 * so we need to check that the conntrack is confirmed
484 return nf_ct_tuple_equal(tuple, &h->tuple) &&
485 nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
486 nf_ct_is_confirmed(ct) &&
487 net_eq(net, nf_ct_net(ct));
492 * - Caller must take a reference on returned object
493 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
495 static struct nf_conntrack_tuple_hash *
496 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
497 const struct nf_conntrack_tuple *tuple, u32 hash)
499 struct nf_conntrack_tuple_hash *h;
500 struct hlist_nulls_head *ct_hash;
501 struct hlist_nulls_node *n;
502 unsigned int bucket, sequence;
506 sequence = read_seqcount_begin(&nf_conntrack_generation);
507 bucket = scale_hash(hash);
508 ct_hash = nf_conntrack_hash;
509 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
511 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
512 if (nf_ct_key_equal(h, tuple, zone, net)) {
513 NF_CT_STAT_INC_ATOMIC(net, found);
516 NF_CT_STAT_INC_ATOMIC(net, searched);
519 * if the nulls value we got at the end of this lookup is
520 * not the expected one, we must restart lookup.
521 * We probably met an item that was moved to another chain.
523 if (get_nulls_value(n) != bucket) {
524 NF_CT_STAT_INC_ATOMIC(net, search_restart);
531 /* Find a connection corresponding to a tuple. */
532 static struct nf_conntrack_tuple_hash *
533 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
534 const struct nf_conntrack_tuple *tuple, u32 hash)
536 struct nf_conntrack_tuple_hash *h;
541 h = ____nf_conntrack_find(net, zone, tuple, hash);
543 ct = nf_ct_tuplehash_to_ctrack(h);
544 if (unlikely(nf_ct_is_dying(ct) ||
545 !atomic_inc_not_zero(&ct->ct_general.use)))
548 if (unlikely(!nf_ct_key_equal(h, tuple, zone, net))) {
559 struct nf_conntrack_tuple_hash *
560 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
561 const struct nf_conntrack_tuple *tuple)
563 return __nf_conntrack_find_get(net, zone, tuple,
564 hash_conntrack_raw(tuple, net));
566 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
568 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
570 unsigned int reply_hash)
572 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
573 &nf_conntrack_hash[hash]);
574 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
575 &nf_conntrack_hash[reply_hash]);
579 nf_conntrack_hash_check_insert(struct nf_conn *ct)
581 const struct nf_conntrack_zone *zone;
582 struct net *net = nf_ct_net(ct);
583 unsigned int hash, reply_hash;
584 struct nf_conntrack_tuple_hash *h;
585 struct hlist_nulls_node *n;
586 unsigned int sequence;
588 zone = nf_ct_zone(ct);
592 sequence = read_seqcount_begin(&nf_conntrack_generation);
593 hash = hash_conntrack(net,
594 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
595 reply_hash = hash_conntrack(net,
596 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
597 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
599 /* See if there's one in the list already, including reverse */
600 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
601 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
605 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
606 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
610 add_timer(&ct->timeout);
612 /* The caller holds a reference to this object */
613 atomic_set(&ct->ct_general.use, 2);
614 __nf_conntrack_hash_insert(ct, hash, reply_hash);
615 nf_conntrack_double_unlock(hash, reply_hash);
616 NF_CT_STAT_INC(net, insert);
621 nf_conntrack_double_unlock(hash, reply_hash);
622 NF_CT_STAT_INC(net, insert_failed);
626 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
628 static inline void nf_ct_acct_update(struct nf_conn *ct,
629 enum ip_conntrack_info ctinfo,
632 struct nf_conn_acct *acct;
634 acct = nf_conn_acct_find(ct);
636 struct nf_conn_counter *counter = acct->counter;
638 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
639 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
643 static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
644 const struct nf_conn *loser_ct)
646 struct nf_conn_acct *acct;
648 acct = nf_conn_acct_find(loser_ct);
650 struct nf_conn_counter *counter = acct->counter;
653 /* u32 should be fine since we must have seen one packet. */
654 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
655 nf_ct_acct_update(ct, ctinfo, bytes);
659 /* Resolve race on insertion if this protocol allows this. */
660 static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
661 enum ip_conntrack_info ctinfo,
662 struct nf_conntrack_tuple_hash *h)
664 /* This is the conntrack entry already in hashes that won race. */
665 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
666 struct nf_conntrack_l4proto *l4proto;
668 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
669 if (l4proto->allow_clash &&
671 !nf_ct_is_dying(ct) &&
672 atomic_inc_not_zero(&ct->ct_general.use)) {
673 nf_ct_acct_merge(ct, ctinfo, (struct nf_conn *)skb->nfct);
674 nf_conntrack_put(skb->nfct);
675 /* Assign conntrack already in hashes to this skbuff. Don't
676 * modify skb->nfctinfo to ensure consistent stateful filtering.
678 skb->nfct = &ct->ct_general;
681 NF_CT_STAT_INC(net, drop);
685 /* Confirm a connection given skb; places it in hash table */
687 __nf_conntrack_confirm(struct sk_buff *skb)
689 const struct nf_conntrack_zone *zone;
690 unsigned int hash, reply_hash;
691 struct nf_conntrack_tuple_hash *h;
693 struct nf_conn_help *help;
694 struct nf_conn_tstamp *tstamp;
695 struct hlist_nulls_node *n;
696 enum ip_conntrack_info ctinfo;
698 unsigned int sequence;
701 ct = nf_ct_get(skb, &ctinfo);
704 /* ipt_REJECT uses nf_conntrack_attach to attach related
705 ICMP/TCP RST packets in other direction. Actual packet
706 which created connection will be IP_CT_NEW or for an
707 expected connection, IP_CT_RELATED. */
708 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
711 zone = nf_ct_zone(ct);
715 sequence = read_seqcount_begin(&nf_conntrack_generation);
716 /* reuse the hash saved before */
717 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
718 hash = scale_hash(hash);
719 reply_hash = hash_conntrack(net,
720 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
722 } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
724 /* We're not in hash table, and we refuse to set up related
725 * connections for unconfirmed conns. But packet copies and
726 * REJECT will give spurious warnings here.
728 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
730 /* No external references means no one else could have
733 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
734 pr_debug("Confirming conntrack %p\n", ct);
735 /* We have to check the DYING flag after unlink to prevent
736 * a race against nf_ct_get_next_corpse() possibly called from
737 * user context, else we insert an already 'dead' hash, blocking
738 * further use of that particular connection -JM.
740 nf_ct_del_from_dying_or_unconfirmed_list(ct);
742 if (unlikely(nf_ct_is_dying(ct))) {
743 nf_ct_add_to_dying_list(ct);
747 /* See if there's one in the list already, including reverse:
748 NAT could have grabbed it without realizing, since we're
749 not in the hash. If there is, we lost race. */
750 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
751 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
755 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
756 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
760 /* Timer relative to confirmation time, not original
761 setting time, otherwise we'd get timer wrap in
762 weird delay cases. */
763 ct->timeout.expires += jiffies;
764 add_timer(&ct->timeout);
765 atomic_inc(&ct->ct_general.use);
766 ct->status |= IPS_CONFIRMED;
768 /* set conntrack timestamp, if enabled. */
769 tstamp = nf_conn_tstamp_find(ct);
771 if (skb->tstamp.tv64 == 0)
772 __net_timestamp(skb);
774 tstamp->start = ktime_to_ns(skb->tstamp);
776 /* Since the lookup is lockless, hash insertion must be done after
777 * starting the timer and setting the CONFIRMED bit. The RCU barriers
778 * guarantee that no other CPU can find the conntrack before the above
779 * stores are visible.
781 __nf_conntrack_hash_insert(ct, hash, reply_hash);
782 nf_conntrack_double_unlock(hash, reply_hash);
783 NF_CT_STAT_INC(net, insert);
786 help = nfct_help(ct);
787 if (help && help->helper)
788 nf_conntrack_event_cache(IPCT_HELPER, ct);
790 nf_conntrack_event_cache(master_ct(ct) ?
791 IPCT_RELATED : IPCT_NEW, ct);
795 nf_ct_add_to_dying_list(ct);
796 ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
798 nf_conntrack_double_unlock(hash, reply_hash);
799 NF_CT_STAT_INC(net, insert_failed);
803 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
805 /* Returns true if a connection correspondings to the tuple (required
808 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
809 const struct nf_conn *ignored_conntrack)
811 struct net *net = nf_ct_net(ignored_conntrack);
812 const struct nf_conntrack_zone *zone;
813 struct nf_conntrack_tuple_hash *h;
814 struct hlist_nulls_head *ct_hash;
815 unsigned int hash, sequence;
816 struct hlist_nulls_node *n;
819 zone = nf_ct_zone(ignored_conntrack);
823 sequence = read_seqcount_begin(&nf_conntrack_generation);
824 hash = hash_conntrack(net, tuple);
825 ct_hash = nf_conntrack_hash;
826 } while (read_seqcount_retry(&nf_conntrack_generation, sequence));
828 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
829 ct = nf_ct_tuplehash_to_ctrack(h);
830 if (ct != ignored_conntrack &&
831 nf_ct_key_equal(h, tuple, zone, net)) {
832 NF_CT_STAT_INC_ATOMIC(net, found);
836 NF_CT_STAT_INC_ATOMIC(net, searched);
842 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
844 #define NF_CT_EVICTION_RANGE 8
846 /* There's a small race here where we may free a just-assured
847 connection. Too bad: we're in trouble anyway. */
848 static noinline int early_drop(struct net *net, unsigned int _hash)
850 /* Use oldest entry, which is roughly LRU */
851 struct nf_conntrack_tuple_hash *h;
853 struct hlist_nulls_node *n;
854 unsigned int i, hash, sequence;
855 struct nf_conn *ct = NULL;
863 sequence = read_seqcount_begin(&nf_conntrack_generation);
864 for (; i < NF_CT_EVICTION_RANGE; i++) {
865 hash = scale_hash(_hash++);
866 lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
867 nf_conntrack_lock(lockp);
868 if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
872 hlist_nulls_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
874 tmp = nf_ct_tuplehash_to_ctrack(h);
876 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
877 !net_eq(nf_ct_net(tmp), net) ||
881 if (atomic_inc_not_zero(&tmp->ct_general.use)) {
897 /* kill only if in same netns -- might have moved due to
898 * SLAB_DESTROY_BY_RCU rules
900 if (net_eq(nf_ct_net(ct), net) && del_timer(&ct->timeout)) {
901 if (nf_ct_delete(ct, 0, 0)) {
902 NF_CT_STAT_INC_ATOMIC(net, early_drop);
911 static struct nf_conn *
912 __nf_conntrack_alloc(struct net *net,
913 const struct nf_conntrack_zone *zone,
914 const struct nf_conntrack_tuple *orig,
915 const struct nf_conntrack_tuple *repl,
920 /* We don't want any race condition at early drop stage */
921 atomic_inc(&net->ct.count);
923 if (nf_conntrack_max &&
924 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
925 if (!early_drop(net, hash)) {
926 atomic_dec(&net->ct.count);
927 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
928 return ERR_PTR(-ENOMEM);
933 * Do not use kmem_cache_zalloc(), as this cache uses
934 * SLAB_DESTROY_BY_RCU.
936 ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
940 spin_lock_init(&ct->lock);
941 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
942 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
943 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
944 /* save hash for reusing when confirming */
945 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
947 /* Don't set timer yet: wait for confirmation */
948 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
949 write_pnet(&ct->ct_net, net);
950 memset(&ct->__nfct_init_offset[0], 0,
951 offsetof(struct nf_conn, proto) -
952 offsetof(struct nf_conn, __nfct_init_offset[0]));
954 if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
957 /* Because we use RCU lookups, we set ct_general.use to zero before
958 * this is inserted in any list.
960 atomic_set(&ct->ct_general.use, 0);
963 kmem_cache_free(nf_conntrack_cachep, ct);
965 atomic_dec(&net->ct.count);
966 return ERR_PTR(-ENOMEM);
969 struct nf_conn *nf_conntrack_alloc(struct net *net,
970 const struct nf_conntrack_zone *zone,
971 const struct nf_conntrack_tuple *orig,
972 const struct nf_conntrack_tuple *repl,
975 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
977 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
979 void nf_conntrack_free(struct nf_conn *ct)
981 struct net *net = nf_ct_net(ct);
983 /* A freed object has refcnt == 0, that's
984 * the golden rule for SLAB_DESTROY_BY_RCU
986 NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
988 nf_ct_ext_destroy(ct);
990 kmem_cache_free(nf_conntrack_cachep, ct);
991 smp_mb__before_atomic();
992 atomic_dec(&net->ct.count);
994 EXPORT_SYMBOL_GPL(nf_conntrack_free);
997 /* Allocate a new conntrack: we return -ENOMEM if classification
998 failed due to stress. Otherwise it really is unclassifiable. */
999 static struct nf_conntrack_tuple_hash *
1000 init_conntrack(struct net *net, struct nf_conn *tmpl,
1001 const struct nf_conntrack_tuple *tuple,
1002 struct nf_conntrack_l3proto *l3proto,
1003 struct nf_conntrack_l4proto *l4proto,
1004 struct sk_buff *skb,
1005 unsigned int dataoff, u32 hash)
1008 struct nf_conn_help *help;
1009 struct nf_conntrack_tuple repl_tuple;
1010 struct nf_conntrack_ecache *ecache;
1011 struct nf_conntrack_expect *exp = NULL;
1012 const struct nf_conntrack_zone *zone;
1013 struct nf_conn_timeout *timeout_ext;
1014 struct nf_conntrack_zone tmp;
1015 unsigned int *timeouts;
1017 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
1018 pr_debug("Can't invert tuple.\n");
1022 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1023 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1026 return (struct nf_conntrack_tuple_hash *)ct;
1028 if (tmpl && nfct_synproxy(tmpl)) {
1029 nfct_seqadj_ext_add(ct);
1030 nfct_synproxy_ext_add(ct);
1033 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1035 timeouts = nf_ct_timeout_data(timeout_ext);
1036 if (unlikely(!timeouts))
1037 timeouts = l4proto->get_timeouts(net);
1039 timeouts = l4proto->get_timeouts(net);
1042 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
1043 nf_conntrack_free(ct);
1044 pr_debug("can't track with proto module\n");
1049 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1052 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1053 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1054 nf_ct_labels_ext_add(ct);
1056 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1057 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1058 ecache ? ecache->expmask : 0,
1062 if (net->ct.expect_count) {
1063 spin_lock(&nf_conntrack_expect_lock);
1064 exp = nf_ct_find_expectation(net, zone, tuple);
1066 pr_debug("expectation arrives ct=%p exp=%p\n",
1068 /* Welcome, Mr. Bond. We've been expecting you... */
1069 __set_bit(IPS_EXPECTED_BIT, &ct->status);
1070 /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1071 ct->master = exp->master;
1073 help = nf_ct_helper_ext_add(ct, exp->helper,
1076 rcu_assign_pointer(help->helper, exp->helper);
1079 #ifdef CONFIG_NF_CONNTRACK_MARK
1080 ct->mark = exp->master->mark;
1082 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1083 ct->secmark = exp->master->secmark;
1085 NF_CT_STAT_INC(net, expect_new);
1087 spin_unlock(&nf_conntrack_expect_lock);
1090 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1091 NF_CT_STAT_INC(net, new);
1094 /* Now it is inserted into the unconfirmed list, bump refcount */
1095 nf_conntrack_get(&ct->ct_general);
1096 nf_ct_add_to_unconfirmed_list(ct);
1102 exp->expectfn(ct, exp);
1103 nf_ct_expect_put(exp);
1106 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1109 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
1110 static inline struct nf_conn *
1111 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
1112 struct sk_buff *skb,
1113 unsigned int dataoff,
1116 struct nf_conntrack_l3proto *l3proto,
1117 struct nf_conntrack_l4proto *l4proto,
1119 enum ip_conntrack_info *ctinfo)
1121 const struct nf_conntrack_zone *zone;
1122 struct nf_conntrack_tuple tuple;
1123 struct nf_conntrack_tuple_hash *h;
1124 struct nf_conntrack_zone tmp;
1128 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1129 dataoff, l3num, protonum, net, &tuple, l3proto,
1131 pr_debug("Can't get tuple\n");
1135 /* look for tuple match */
1136 zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1137 hash = hash_conntrack_raw(&tuple, net);
1138 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
1140 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
1141 skb, dataoff, hash);
1147 ct = nf_ct_tuplehash_to_ctrack(h);
1149 /* It exists; we have (non-exclusive) reference. */
1150 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1151 *ctinfo = IP_CT_ESTABLISHED_REPLY;
1152 /* Please set reply bit if this packet OK */
1155 /* Once we've had two way comms, always ESTABLISHED. */
1156 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1157 pr_debug("normal packet for %p\n", ct);
1158 *ctinfo = IP_CT_ESTABLISHED;
1159 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1160 pr_debug("related packet for %p\n", ct);
1161 *ctinfo = IP_CT_RELATED;
1163 pr_debug("new packet for %p\n", ct);
1164 *ctinfo = IP_CT_NEW;
1168 skb->nfct = &ct->ct_general;
1169 skb->nfctinfo = *ctinfo;
1174 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
1175 struct sk_buff *skb)
1177 struct nf_conn *ct, *tmpl = NULL;
1178 enum ip_conntrack_info ctinfo;
1179 struct nf_conntrack_l3proto *l3proto;
1180 struct nf_conntrack_l4proto *l4proto;
1181 unsigned int *timeouts;
1182 unsigned int dataoff;
1188 /* Previously seen (loopback or untracked)? Ignore. */
1189 tmpl = (struct nf_conn *)skb->nfct;
1190 if (!nf_ct_is_template(tmpl)) {
1191 NF_CT_STAT_INC_ATOMIC(net, ignore);
1197 /* rcu_read_lock()ed by nf_hook_slow */
1198 l3proto = __nf_ct_l3proto_find(pf);
1199 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
1200 &dataoff, &protonum);
1202 pr_debug("not prepared to track yet or error occurred\n");
1203 NF_CT_STAT_INC_ATOMIC(net, error);
1204 NF_CT_STAT_INC_ATOMIC(net, invalid);
1209 l4proto = __nf_ct_l4proto_find(pf, protonum);
1211 /* It may be an special packet, error, unclean...
1212 * inverse of the return code tells to the netfilter
1213 * core what to do with the packet. */
1214 if (l4proto->error != NULL) {
1215 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
1218 NF_CT_STAT_INC_ATOMIC(net, error);
1219 NF_CT_STAT_INC_ATOMIC(net, invalid);
1223 /* ICMP[v6] protocol trackers may assign one conntrack. */
1228 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
1229 l3proto, l4proto, &set_reply, &ctinfo);
1231 /* Not valid part of a connection */
1232 NF_CT_STAT_INC_ATOMIC(net, invalid);
1238 /* Too stressed to deal. */
1239 NF_CT_STAT_INC_ATOMIC(net, drop);
1244 NF_CT_ASSERT(skb->nfct);
1246 /* Decide what timeout policy we want to apply to this flow. */
1247 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1249 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1251 /* Invalid: inverse of the return code tells
1252 * the netfilter core what to do */
1253 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1254 nf_conntrack_put(skb->nfct);
1256 NF_CT_STAT_INC_ATOMIC(net, invalid);
1257 if (ret == -NF_DROP)
1258 NF_CT_STAT_INC_ATOMIC(net, drop);
1263 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1264 nf_conntrack_event_cache(IPCT_REPLY, ct);
1267 /* Special case: we have to repeat this hook, assign the
1268 * template again to this packet. We assume that this packet
1269 * has no conntrack assigned. This is used by nf_ct_tcp. */
1270 if (ret == NF_REPEAT)
1271 skb->nfct = (struct nf_conntrack *)tmpl;
1278 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1280 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1281 const struct nf_conntrack_tuple *orig)
1286 ret = nf_ct_invert_tuple(inverse, orig,
1287 __nf_ct_l3proto_find(orig->src.l3num),
1288 __nf_ct_l4proto_find(orig->src.l3num,
1289 orig->dst.protonum));
1293 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1295 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1296 implicitly racy: see __nf_conntrack_confirm */
1297 void nf_conntrack_alter_reply(struct nf_conn *ct,
1298 const struct nf_conntrack_tuple *newreply)
1300 struct nf_conn_help *help = nfct_help(ct);
1302 /* Should be unconfirmed, so not in hash table yet */
1303 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1305 pr_debug("Altering reply tuple of %p to ", ct);
1306 nf_ct_dump_tuple(newreply);
1308 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1309 if (ct->master || (help && !hlist_empty(&help->expectations)))
1313 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1316 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1318 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1319 void __nf_ct_refresh_acct(struct nf_conn *ct,
1320 enum ip_conntrack_info ctinfo,
1321 const struct sk_buff *skb,
1322 unsigned long extra_jiffies,
1325 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1328 /* Only update if this is not a fixed timeout */
1329 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1332 /* If not in hash table, timer will not be active yet */
1333 if (!nf_ct_is_confirmed(ct)) {
1334 ct->timeout.expires = extra_jiffies;
1336 unsigned long newtime = jiffies + extra_jiffies;
1338 /* Only update the timeout if the new timeout is at least
1339 HZ jiffies from the old timeout. Need del_timer for race
1340 avoidance (may already be dying). */
1341 if (newtime - ct->timeout.expires >= HZ)
1342 mod_timer_pending(&ct->timeout, newtime);
1347 nf_ct_acct_update(ct, ctinfo, skb->len);
1349 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1351 bool __nf_ct_kill_acct(struct nf_conn *ct,
1352 enum ip_conntrack_info ctinfo,
1353 const struct sk_buff *skb,
1357 nf_ct_acct_update(ct, ctinfo, skb->len);
1359 if (del_timer(&ct->timeout)) {
1360 ct->timeout.function((unsigned long)ct);
1365 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1367 #ifdef CONFIG_NF_CONNTRACK_ZONES
1368 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1369 .len = sizeof(struct nf_conntrack_zone),
1370 .align = __alignof__(struct nf_conntrack_zone),
1371 .id = NF_CT_EXT_ZONE,
1375 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1377 #include <linux/netfilter/nfnetlink.h>
1378 #include <linux/netfilter/nfnetlink_conntrack.h>
1379 #include <linux/mutex.h>
1381 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1382 * in ip_conntrack_core, since we don't want the protocols to autoload
1383 * or depend on ctnetlink */
1384 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1385 const struct nf_conntrack_tuple *tuple)
1387 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1388 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1389 goto nla_put_failure;
1395 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1397 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1398 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1399 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1401 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1403 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1404 struct nf_conntrack_tuple *t)
1406 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1409 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1410 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1414 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1416 int nf_ct_port_nlattr_tuple_size(void)
1418 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1420 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1423 /* Used by ipt_REJECT and ip6t_REJECT. */
1424 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1427 enum ip_conntrack_info ctinfo;
1429 /* This ICMP is in reverse direction to the packet which caused it */
1430 ct = nf_ct_get(skb, &ctinfo);
1431 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1432 ctinfo = IP_CT_RELATED_REPLY;
1434 ctinfo = IP_CT_RELATED;
1436 /* Attach to new skbuff, and increment count */
1437 nskb->nfct = &ct->ct_general;
1438 nskb->nfctinfo = ctinfo;
1439 nf_conntrack_get(nskb->nfct);
1442 /* Bring out ya dead! */
1443 static struct nf_conn *
1444 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1445 void *data, unsigned int *bucket)
1447 struct nf_conntrack_tuple_hash *h;
1449 struct hlist_nulls_node *n;
1453 for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1454 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1456 nf_conntrack_lock(lockp);
1457 if (*bucket < nf_conntrack_htable_size) {
1458 hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
1459 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1461 ct = nf_ct_tuplehash_to_ctrack(h);
1462 if (net_eq(nf_ct_net(ct), net) &&
1472 for_each_possible_cpu(cpu) {
1473 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1475 spin_lock_bh(&pcpu->lock);
1476 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
1477 ct = nf_ct_tuplehash_to_ctrack(h);
1479 set_bit(IPS_DYING_BIT, &ct->status);
1481 spin_unlock_bh(&pcpu->lock);
1486 atomic_inc(&ct->ct_general.use);
1492 void nf_ct_iterate_cleanup(struct net *net,
1493 int (*iter)(struct nf_conn *i, void *data),
1494 void *data, u32 portid, int report)
1497 unsigned int bucket = 0;
1501 if (atomic_read(&net->ct.count) == 0)
1504 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1505 /* Time to push up daises... */
1506 if (del_timer(&ct->timeout))
1507 nf_ct_delete(ct, portid, report);
1509 /* ... else the timer will get him soon. */
1515 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1517 static int kill_all(struct nf_conn *i, void *data)
1522 void nf_ct_free_hashtable(void *hash, unsigned int size)
1524 if (is_vmalloc_addr(hash))
1527 free_pages((unsigned long)hash,
1528 get_order(sizeof(struct hlist_head) * size));
1530 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1532 static int untrack_refs(void)
1536 for_each_possible_cpu(cpu) {
1537 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1539 cnt += atomic_read(&ct->ct_general.use) - 1;
1544 void nf_conntrack_cleanup_start(void)
1546 RCU_INIT_POINTER(ip_ct_attach, NULL);
1549 void nf_conntrack_cleanup_end(void)
1551 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1552 while (untrack_refs() > 0)
1555 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1557 #ifdef CONFIG_NF_CONNTRACK_ZONES
1558 nf_ct_extend_unregister(&nf_ct_zone_extend);
1560 nf_conntrack_proto_fini();
1561 nf_conntrack_seqadj_fini();
1562 nf_conntrack_labels_fini();
1563 nf_conntrack_helper_fini();
1564 nf_conntrack_timeout_fini();
1565 nf_conntrack_ecache_fini();
1566 nf_conntrack_tstamp_fini();
1567 nf_conntrack_acct_fini();
1568 nf_conntrack_expect_fini();
1570 kmem_cache_destroy(nf_conntrack_cachep);
1574 * Mishearing the voices in his head, our hero wonders how he's
1575 * supposed to kill the mall.
1577 void nf_conntrack_cleanup_net(struct net *net)
1581 list_add(&net->exit_list, &single);
1582 nf_conntrack_cleanup_net_list(&single);
1585 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1591 * This makes sure all current packets have passed through
1592 * netfilter framework. Roll on, two-stage module
1598 list_for_each_entry(net, net_exit_list, exit_list) {
1599 nf_ct_iterate_cleanup(net, kill_all, NULL, 0, 0);
1600 if (atomic_read(&net->ct.count) != 0)
1605 goto i_see_dead_people;
1608 list_for_each_entry(net, net_exit_list, exit_list) {
1609 nf_conntrack_proto_pernet_fini(net);
1610 nf_conntrack_helper_pernet_fini(net);
1611 nf_conntrack_ecache_pernet_fini(net);
1612 nf_conntrack_tstamp_pernet_fini(net);
1613 nf_conntrack_acct_pernet_fini(net);
1614 nf_conntrack_expect_pernet_fini(net);
1615 free_percpu(net->ct.stat);
1616 free_percpu(net->ct.pcpu_lists);
1620 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1622 struct hlist_nulls_head *hash;
1623 unsigned int nr_slots, i;
1626 if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1629 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1630 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1632 if (nr_slots > (UINT_MAX / sizeof(struct hlist_nulls_head)))
1635 sz = nr_slots * sizeof(struct hlist_nulls_head);
1636 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1642 for (i = 0; i < nr_slots; i++)
1643 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1647 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1649 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1652 unsigned int hashsize, old_size;
1653 struct hlist_nulls_head *hash, *old_hash;
1654 struct nf_conntrack_tuple_hash *h;
1657 if (current->nsproxy->net_ns != &init_net)
1660 /* On boot, we can set this without any fancy locking. */
1661 if (!nf_conntrack_htable_size)
1662 return param_set_uint(val, kp);
1664 rc = kstrtouint(val, 0, &hashsize);
1670 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1675 nf_conntrack_all_lock();
1676 write_seqcount_begin(&nf_conntrack_generation);
1678 /* Lookups in the old hash might happen in parallel, which means we
1679 * might get false negatives during connection lookup. New connections
1680 * created because of a false negative won't make it into the hash
1681 * though since that required taking the locks.
1684 for (i = 0; i < nf_conntrack_htable_size; i++) {
1685 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
1686 h = hlist_nulls_entry(nf_conntrack_hash[i].first,
1687 struct nf_conntrack_tuple_hash, hnnode);
1688 ct = nf_ct_tuplehash_to_ctrack(h);
1689 hlist_nulls_del_rcu(&h->hnnode);
1690 bucket = __hash_conntrack(nf_ct_net(ct),
1691 &h->tuple, hashsize);
1692 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1695 old_size = nf_conntrack_htable_size;
1696 old_hash = nf_conntrack_hash;
1698 nf_conntrack_hash = hash;
1699 nf_conntrack_htable_size = hashsize;
1701 write_seqcount_end(&nf_conntrack_generation);
1702 nf_conntrack_all_unlock();
1706 nf_ct_free_hashtable(old_hash, old_size);
1709 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1711 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1712 &nf_conntrack_htable_size, 0600);
1714 void nf_ct_untracked_status_or(unsigned long bits)
1718 for_each_possible_cpu(cpu)
1719 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1721 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1723 int nf_conntrack_init_start(void)
1729 seqcount_init(&nf_conntrack_generation);
1731 for (i = 0; i < CONNTRACK_LOCKS; i++)
1732 spin_lock_init(&nf_conntrack_locks[i]);
1734 if (!nf_conntrack_htable_size) {
1735 /* Idea from tcp.c: use 1/16384 of memory.
1736 * On i386: 32MB machine has 512 buckets.
1737 * >= 1GB machines have 16384 buckets.
1738 * >= 4GB machines have 65536 buckets.
1740 nf_conntrack_htable_size
1741 = (((totalram_pages << PAGE_SHIFT) / 16384)
1742 / sizeof(struct hlist_head));
1743 if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
1744 nf_conntrack_htable_size = 65536;
1745 else if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1746 nf_conntrack_htable_size = 16384;
1747 if (nf_conntrack_htable_size < 32)
1748 nf_conntrack_htable_size = 32;
1750 /* Use a max. factor of four by default to get the same max as
1751 * with the old struct list_heads. When a table size is given
1752 * we use the old value of 8 to avoid reducing the max.
1757 nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
1758 if (!nf_conntrack_hash)
1761 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1763 nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1764 sizeof(struct nf_conn), 0,
1765 SLAB_DESTROY_BY_RCU, NULL);
1766 if (!nf_conntrack_cachep)
1769 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1770 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1773 ret = nf_conntrack_expect_init();
1777 ret = nf_conntrack_acct_init();
1781 ret = nf_conntrack_tstamp_init();
1785 ret = nf_conntrack_ecache_init();
1789 ret = nf_conntrack_timeout_init();
1793 ret = nf_conntrack_helper_init();
1797 ret = nf_conntrack_labels_init();
1801 ret = nf_conntrack_seqadj_init();
1805 #ifdef CONFIG_NF_CONNTRACK_ZONES
1806 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1810 ret = nf_conntrack_proto_init();
1814 /* Set up fake conntrack: to never be deleted, not in any hashes */
1815 for_each_possible_cpu(cpu) {
1816 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1817 write_pnet(&ct->ct_net, &init_net);
1818 atomic_set(&ct->ct_general.use, 1);
1820 /* - and look it like as a confirmed connection */
1821 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1825 #ifdef CONFIG_NF_CONNTRACK_ZONES
1826 nf_ct_extend_unregister(&nf_ct_zone_extend);
1829 nf_conntrack_seqadj_fini();
1831 nf_conntrack_labels_fini();
1833 nf_conntrack_helper_fini();
1835 nf_conntrack_timeout_fini();
1837 nf_conntrack_ecache_fini();
1839 nf_conntrack_tstamp_fini();
1841 nf_conntrack_acct_fini();
1843 nf_conntrack_expect_fini();
1845 kmem_cache_destroy(nf_conntrack_cachep);
1847 nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
1851 void nf_conntrack_init_end(void)
1853 /* For use by REJECT target */
1854 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1855 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1859 * We need to use special "null" values, not used in hash table
1861 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1862 #define DYING_NULLS_VAL ((1<<30)+1)
1863 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1865 int nf_conntrack_init_net(struct net *net)
1870 atomic_set(&net->ct.count, 0);
1872 net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
1873 if (!net->ct.pcpu_lists)
1876 for_each_possible_cpu(cpu) {
1877 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1879 spin_lock_init(&pcpu->lock);
1880 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
1881 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
1884 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1886 goto err_pcpu_lists;
1888 ret = nf_conntrack_expect_pernet_init(net);
1891 ret = nf_conntrack_acct_pernet_init(net);
1894 ret = nf_conntrack_tstamp_pernet_init(net);
1897 ret = nf_conntrack_ecache_pernet_init(net);
1900 ret = nf_conntrack_helper_pernet_init(net);
1903 ret = nf_conntrack_proto_pernet_init(net);
1909 nf_conntrack_helper_pernet_fini(net);
1911 nf_conntrack_ecache_pernet_fini(net);
1913 nf_conntrack_tstamp_pernet_fini(net);
1915 nf_conntrack_acct_pernet_fini(net);
1917 nf_conntrack_expect_pernet_fini(net);
1919 free_percpu(net->ct.stat);
1921 free_percpu(net->ct.pcpu_lists);