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>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/skbuff.h>
19 #include <linux/proc_fs.h>
20 #include <linux/vmalloc.h>
21 #include <linux/stddef.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/jhash.h>
25 #include <linux/err.h>
26 #include <linux/percpu.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/kernel.h>
30 #include <linux/netdevice.h>
31 #include <linux/socket.h>
33 #include <linux/nsproxy.h>
34 #include <linux/rculist_nulls.h>
36 #include <net/netfilter/nf_conntrack.h>
37 #include <net/netfilter/nf_conntrack_l3proto.h>
38 #include <net/netfilter/nf_conntrack_l4proto.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_core.h>
42 #include <net/netfilter/nf_conntrack_extend.h>
43 #include <net/netfilter/nf_conntrack_acct.h>
44 #include <net/netfilter/nf_conntrack_ecache.h>
45 #include <net/netfilter/nf_conntrack_zones.h>
46 #include <net/netfilter/nf_conntrack_timestamp.h>
47 #include <net/netfilter/nf_nat.h>
48 #include <net/netfilter/nf_nat_core.h>
50 #define NF_CONNTRACK_VERSION "0.5.0"
52 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
53 enum nf_nat_manip_type manip,
54 const struct nlattr *attr) __read_mostly;
55 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
57 DEFINE_SPINLOCK(nf_conntrack_lock);
58 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
60 unsigned int nf_conntrack_htable_size __read_mostly;
61 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
63 unsigned int nf_conntrack_max __read_mostly;
64 EXPORT_SYMBOL_GPL(nf_conntrack_max);
66 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
67 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
69 unsigned int nf_conntrack_hash_rnd __read_mostly;
71 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
75 /* The direction must be ignored, so we hash everything up to the
76 * destination ports (which is a multiple of 4) and treat the last
77 * three bytes manually.
79 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
80 return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
81 (((__force __u16)tuple->dst.u.all << 16) |
82 tuple->dst.protonum));
85 static u32 __hash_bucket(u32 hash, unsigned int size)
87 return ((u64)hash * size) >> 32;
90 static u32 hash_bucket(u32 hash, const struct net *net)
92 return __hash_bucket(hash, net->ct.htable_size);
95 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
96 u16 zone, unsigned int size)
98 return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
101 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
102 const struct nf_conntrack_tuple *tuple)
104 return __hash_conntrack(tuple, zone, net->ct.htable_size);
108 nf_ct_get_tuple(const struct sk_buff *skb,
110 unsigned int dataoff,
113 struct nf_conntrack_tuple *tuple,
114 const struct nf_conntrack_l3proto *l3proto,
115 const struct nf_conntrack_l4proto *l4proto)
117 memset(tuple, 0, sizeof(*tuple));
119 tuple->src.l3num = l3num;
120 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
123 tuple->dst.protonum = protonum;
124 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
126 return l4proto->pkt_to_tuple(skb, dataoff, tuple);
128 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
130 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
131 u_int16_t l3num, struct nf_conntrack_tuple *tuple)
133 struct nf_conntrack_l3proto *l3proto;
134 struct nf_conntrack_l4proto *l4proto;
135 unsigned int protoff;
141 l3proto = __nf_ct_l3proto_find(l3num);
142 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
143 if (ret != NF_ACCEPT) {
148 l4proto = __nf_ct_l4proto_find(l3num, protonum);
150 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
156 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
159 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
160 const struct nf_conntrack_tuple *orig,
161 const struct nf_conntrack_l3proto *l3proto,
162 const struct nf_conntrack_l4proto *l4proto)
164 memset(inverse, 0, sizeof(*inverse));
166 inverse->src.l3num = orig->src.l3num;
167 if (l3proto->invert_tuple(inverse, orig) == 0)
170 inverse->dst.dir = !orig->dst.dir;
172 inverse->dst.protonum = orig->dst.protonum;
173 return l4proto->invert_tuple(inverse, orig);
175 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
178 clean_from_lists(struct nf_conn *ct)
180 pr_debug("clean_from_lists(%p)\n", ct);
181 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
182 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
184 /* Destroy all pending expectations */
185 nf_ct_remove_expectations(ct);
189 destroy_conntrack(struct nf_conntrack *nfct)
191 struct nf_conn *ct = (struct nf_conn *)nfct;
192 struct net *net = nf_ct_net(ct);
193 struct nf_conntrack_l4proto *l4proto;
195 pr_debug("destroy_conntrack(%p)\n", ct);
196 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
197 NF_CT_ASSERT(!timer_pending(&ct->timeout));
199 /* To make sure we don't get any weird locking issues here:
200 * destroy_conntrack() MUST NOT be called with a write lock
201 * to nf_conntrack_lock!!! -HW */
203 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
204 if (l4proto && l4proto->destroy)
205 l4proto->destroy(ct);
209 spin_lock_bh(&nf_conntrack_lock);
210 /* Expectations will have been removed in clean_from_lists,
211 * except TFTP can create an expectation on the first packet,
212 * before connection is in the list, so we need to clean here,
214 nf_ct_remove_expectations(ct);
216 /* We overload first tuple to link into unconfirmed list. */
217 if (!nf_ct_is_confirmed(ct)) {
218 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
219 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
222 NF_CT_STAT_INC(net, delete);
223 spin_unlock_bh(&nf_conntrack_lock);
226 nf_ct_put(ct->master);
228 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
229 nf_conntrack_free(ct);
232 void nf_ct_delete_from_lists(struct nf_conn *ct)
234 struct net *net = nf_ct_net(ct);
236 nf_ct_helper_destroy(ct);
237 spin_lock_bh(&nf_conntrack_lock);
238 /* Inside lock so preempt is disabled on module removal path.
239 * Otherwise we can get spurious warnings. */
240 NF_CT_STAT_INC(net, delete_list);
241 clean_from_lists(ct);
242 spin_unlock_bh(&nf_conntrack_lock);
244 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
246 static void death_by_event(unsigned long ul_conntrack)
248 struct nf_conn *ct = (void *)ul_conntrack;
249 struct net *net = nf_ct_net(ct);
250 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
252 BUG_ON(ecache == NULL);
254 if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
255 /* bad luck, let's retry again */
256 ecache->timeout.expires = jiffies +
257 (random32() % net->ct.sysctl_events_retry_timeout);
258 add_timer(&ecache->timeout);
261 /* we've got the event delivered, now it's dying */
262 set_bit(IPS_DYING_BIT, &ct->status);
263 spin_lock(&nf_conntrack_lock);
264 hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
265 spin_unlock(&nf_conntrack_lock);
269 void nf_ct_insert_dying_list(struct nf_conn *ct)
271 struct net *net = nf_ct_net(ct);
272 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
274 BUG_ON(ecache == NULL);
276 /* add this conntrack to the dying list */
277 spin_lock_bh(&nf_conntrack_lock);
278 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
280 spin_unlock_bh(&nf_conntrack_lock);
281 /* set a new timer to retry event delivery */
282 setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
283 ecache->timeout.expires = jiffies +
284 (random32() % net->ct.sysctl_events_retry_timeout);
285 add_timer(&ecache->timeout);
287 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
289 static void death_by_timeout(unsigned long ul_conntrack)
291 struct nf_conn *ct = (void *)ul_conntrack;
292 struct nf_conn_tstamp *tstamp;
294 tstamp = nf_conn_tstamp_find(ct);
295 if (tstamp && tstamp->stop == 0)
296 tstamp->stop = ktime_to_ns(ktime_get_real());
298 if (!test_bit(IPS_DYING_BIT, &ct->status) &&
299 unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
300 /* destroy event was not delivered */
301 nf_ct_delete_from_lists(ct);
302 nf_ct_insert_dying_list(ct);
305 set_bit(IPS_DYING_BIT, &ct->status);
306 nf_ct_delete_from_lists(ct);
312 * - Caller must take a reference on returned object
313 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
315 * - Caller must lock nf_conntrack_lock before calling this function
317 static struct nf_conntrack_tuple_hash *
318 ____nf_conntrack_find(struct net *net, u16 zone,
319 const struct nf_conntrack_tuple *tuple, u32 hash)
321 struct nf_conntrack_tuple_hash *h;
322 struct hlist_nulls_node *n;
323 unsigned int bucket = hash_bucket(hash, net);
325 /* Disable BHs the entire time since we normally need to disable them
326 * at least once for the stats anyway.
330 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
331 if (nf_ct_tuple_equal(tuple, &h->tuple) &&
332 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
333 NF_CT_STAT_INC(net, found);
337 NF_CT_STAT_INC(net, searched);
340 * if the nulls value we got at the end of this lookup is
341 * not the expected one, we must restart lookup.
342 * We probably met an item that was moved to another chain.
344 if (get_nulls_value(n) != bucket) {
345 NF_CT_STAT_INC(net, search_restart);
353 struct nf_conntrack_tuple_hash *
354 __nf_conntrack_find(struct net *net, u16 zone,
355 const struct nf_conntrack_tuple *tuple)
357 return ____nf_conntrack_find(net, zone, tuple,
358 hash_conntrack_raw(tuple, zone));
360 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
362 /* Find a connection corresponding to a tuple. */
363 static struct nf_conntrack_tuple_hash *
364 __nf_conntrack_find_get(struct net *net, u16 zone,
365 const struct nf_conntrack_tuple *tuple, u32 hash)
367 struct nf_conntrack_tuple_hash *h;
372 h = ____nf_conntrack_find(net, zone, tuple, hash);
374 ct = nf_ct_tuplehash_to_ctrack(h);
375 if (unlikely(nf_ct_is_dying(ct) ||
376 !atomic_inc_not_zero(&ct->ct_general.use)))
379 if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
380 nf_ct_zone(ct) != zone)) {
391 struct nf_conntrack_tuple_hash *
392 nf_conntrack_find_get(struct net *net, u16 zone,
393 const struct nf_conntrack_tuple *tuple)
395 return __nf_conntrack_find_get(net, zone, tuple,
396 hash_conntrack_raw(tuple, zone));
398 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
400 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
402 unsigned int repl_hash)
404 struct net *net = nf_ct_net(ct);
406 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
407 &net->ct.hash[hash]);
408 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
409 &net->ct.hash[repl_hash]);
412 void nf_conntrack_hash_insert(struct nf_conn *ct)
414 struct net *net = nf_ct_net(ct);
415 unsigned int hash, repl_hash;
418 zone = nf_ct_zone(ct);
419 hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
420 repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
422 __nf_conntrack_hash_insert(ct, hash, repl_hash);
424 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
426 /* Confirm a connection given skb; places it in hash table */
428 __nf_conntrack_confirm(struct sk_buff *skb)
430 unsigned int hash, repl_hash;
431 struct nf_conntrack_tuple_hash *h;
433 struct nf_conn_help *help;
434 struct nf_conn_tstamp *tstamp;
435 struct hlist_nulls_node *n;
436 enum ip_conntrack_info ctinfo;
440 ct = nf_ct_get(skb, &ctinfo);
443 /* ipt_REJECT uses nf_conntrack_attach to attach related
444 ICMP/TCP RST packets in other direction. Actual packet
445 which created connection will be IP_CT_NEW or for an
446 expected connection, IP_CT_RELATED. */
447 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
450 zone = nf_ct_zone(ct);
451 /* reuse the hash saved before */
452 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
453 hash = hash_bucket(hash, net);
454 repl_hash = hash_conntrack(net, zone,
455 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
457 /* We're not in hash table, and we refuse to set up related
458 connections for unconfirmed conns. But packet copies and
459 REJECT will give spurious warnings here. */
460 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
462 /* No external references means no one else could have
464 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
465 pr_debug("Confirming conntrack %p\n", ct);
467 spin_lock_bh(&nf_conntrack_lock);
469 /* We have to check the DYING flag inside the lock to prevent
470 a race against nf_ct_get_next_corpse() possibly called from
471 user context, else we insert an already 'dead' hash, blocking
472 further use of that particular connection -JM */
474 if (unlikely(nf_ct_is_dying(ct))) {
475 spin_unlock_bh(&nf_conntrack_lock);
479 /* See if there's one in the list already, including reverse:
480 NAT could have grabbed it without realizing, since we're
481 not in the hash. If there is, we lost race. */
482 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
483 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
485 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
487 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
488 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
490 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
493 /* Remove from unconfirmed list */
494 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
496 /* Timer relative to confirmation time, not original
497 setting time, otherwise we'd get timer wrap in
498 weird delay cases. */
499 ct->timeout.expires += jiffies;
500 add_timer(&ct->timeout);
501 atomic_inc(&ct->ct_general.use);
502 ct->status |= IPS_CONFIRMED;
504 /* set conntrack timestamp, if enabled. */
505 tstamp = nf_conn_tstamp_find(ct);
507 if (skb->tstamp.tv64 == 0)
508 __net_timestamp((struct sk_buff *)skb);
510 tstamp->start = ktime_to_ns(skb->tstamp);
512 /* Since the lookup is lockless, hash insertion must be done after
513 * starting the timer and setting the CONFIRMED bit. The RCU barriers
514 * guarantee that no other CPU can find the conntrack before the above
515 * stores are visible.
517 __nf_conntrack_hash_insert(ct, hash, repl_hash);
518 NF_CT_STAT_INC(net, insert);
519 spin_unlock_bh(&nf_conntrack_lock);
521 help = nfct_help(ct);
522 if (help && help->helper)
523 nf_conntrack_event_cache(IPCT_HELPER, ct);
525 nf_conntrack_event_cache(master_ct(ct) ?
526 IPCT_RELATED : IPCT_NEW, ct);
530 NF_CT_STAT_INC(net, insert_failed);
531 spin_unlock_bh(&nf_conntrack_lock);
534 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
536 /* Returns true if a connection correspondings to the tuple (required
539 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
540 const struct nf_conn *ignored_conntrack)
542 struct net *net = nf_ct_net(ignored_conntrack);
543 struct nf_conntrack_tuple_hash *h;
544 struct hlist_nulls_node *n;
546 u16 zone = nf_ct_zone(ignored_conntrack);
547 unsigned int hash = hash_conntrack(net, zone, tuple);
549 /* Disable BHs the entire time since we need to disable them at
550 * least once for the stats anyway.
553 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
554 ct = nf_ct_tuplehash_to_ctrack(h);
555 if (ct != ignored_conntrack &&
556 nf_ct_tuple_equal(tuple, &h->tuple) &&
557 nf_ct_zone(ct) == zone) {
558 NF_CT_STAT_INC(net, found);
559 rcu_read_unlock_bh();
562 NF_CT_STAT_INC(net, searched);
564 rcu_read_unlock_bh();
568 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
570 #define NF_CT_EVICTION_RANGE 8
572 /* There's a small race here where we may free a just-assured
573 connection. Too bad: we're in trouble anyway. */
574 static noinline int early_drop(struct net *net, unsigned int hash)
576 /* Use oldest entry, which is roughly LRU */
577 struct nf_conntrack_tuple_hash *h;
578 struct nf_conn *ct = NULL, *tmp;
579 struct hlist_nulls_node *n;
580 unsigned int i, cnt = 0;
584 for (i = 0; i < net->ct.htable_size; i++) {
585 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
587 tmp = nf_ct_tuplehash_to_ctrack(h);
588 if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
594 if (likely(!nf_ct_is_dying(ct) &&
595 atomic_inc_not_zero(&ct->ct_general.use)))
601 if (cnt >= NF_CT_EVICTION_RANGE)
604 hash = (hash + 1) % net->ct.htable_size;
611 if (del_timer(&ct->timeout)) {
612 death_by_timeout((unsigned long)ct);
614 NF_CT_STAT_INC_ATOMIC(net, early_drop);
620 void init_nf_conntrack_hash_rnd(void)
625 * Why not initialize nf_conntrack_rnd in a "init()" function ?
626 * Because there isn't enough entropy when system initializing,
627 * and we initialize it as late as possible.
630 get_random_bytes(&rand, sizeof(rand));
632 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
635 static struct nf_conn *
636 __nf_conntrack_alloc(struct net *net, u16 zone,
637 const struct nf_conntrack_tuple *orig,
638 const struct nf_conntrack_tuple *repl,
643 if (unlikely(!nf_conntrack_hash_rnd)) {
644 init_nf_conntrack_hash_rnd();
645 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
646 hash = hash_conntrack_raw(orig, zone);
649 /* We don't want any race condition at early drop stage */
650 atomic_inc(&net->ct.count);
652 if (nf_conntrack_max &&
653 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
654 if (!early_drop(net, hash_bucket(hash, net))) {
655 atomic_dec(&net->ct.count);
658 "nf_conntrack: table full, dropping"
660 return ERR_PTR(-ENOMEM);
665 * Do not use kmem_cache_zalloc(), as this cache uses
666 * SLAB_DESTROY_BY_RCU.
668 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
670 atomic_dec(&net->ct.count);
671 return ERR_PTR(-ENOMEM);
674 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
675 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
677 memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
678 offsetof(struct nf_conn, proto) -
679 offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
680 spin_lock_init(&ct->lock);
681 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
682 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
683 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
684 /* save hash for reusing when confirming */
685 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
686 /* Don't set timer yet: wait for confirmation */
687 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
688 write_pnet(&ct->ct_net, net);
689 #ifdef CONFIG_NF_CONNTRACK_ZONES
691 struct nf_conntrack_zone *nf_ct_zone;
693 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
696 nf_ct_zone->id = zone;
700 * changes to lookup keys must be done before setting refcnt to 1
703 atomic_set(&ct->ct_general.use, 1);
706 #ifdef CONFIG_NF_CONNTRACK_ZONES
708 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
709 return ERR_PTR(-ENOMEM);
713 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
714 const struct nf_conntrack_tuple *orig,
715 const struct nf_conntrack_tuple *repl,
718 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
720 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
722 void nf_conntrack_free(struct nf_conn *ct)
724 struct net *net = nf_ct_net(ct);
726 nf_ct_ext_destroy(ct);
727 atomic_dec(&net->ct.count);
729 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
731 EXPORT_SYMBOL_GPL(nf_conntrack_free);
733 /* Allocate a new conntrack: we return -ENOMEM if classification
734 failed due to stress. Otherwise it really is unclassifiable. */
735 static struct nf_conntrack_tuple_hash *
736 init_conntrack(struct net *net, struct nf_conn *tmpl,
737 const struct nf_conntrack_tuple *tuple,
738 struct nf_conntrack_l3proto *l3proto,
739 struct nf_conntrack_l4proto *l4proto,
741 unsigned int dataoff, u32 hash)
744 struct nf_conn_help *help;
745 struct nf_conntrack_tuple repl_tuple;
746 struct nf_conntrack_ecache *ecache;
747 struct nf_conntrack_expect *exp;
748 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
750 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
751 pr_debug("Can't invert tuple.\n");
755 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
758 return (struct nf_conntrack_tuple_hash *)ct;
760 if (!l4proto->new(ct, skb, dataoff)) {
761 nf_conntrack_free(ct);
762 pr_debug("init conntrack: can't track with proto module\n");
766 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
767 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
769 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
770 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
771 ecache ? ecache->expmask : 0,
774 spin_lock_bh(&nf_conntrack_lock);
775 exp = nf_ct_find_expectation(net, zone, tuple);
777 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
779 /* Welcome, Mr. Bond. We've been expecting you... */
780 __set_bit(IPS_EXPECTED_BIT, &ct->status);
781 ct->master = exp->master;
783 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
785 rcu_assign_pointer(help->helper, exp->helper);
788 #ifdef CONFIG_NF_CONNTRACK_MARK
789 ct->mark = exp->master->mark;
791 #ifdef CONFIG_NF_CONNTRACK_SECMARK
792 ct->secmark = exp->master->secmark;
794 nf_conntrack_get(&ct->master->ct_general);
795 NF_CT_STAT_INC(net, expect_new);
797 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
798 NF_CT_STAT_INC(net, new);
801 /* Overload tuple linked list to put us in unconfirmed list. */
802 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
803 &net->ct.unconfirmed);
805 spin_unlock_bh(&nf_conntrack_lock);
809 exp->expectfn(ct, exp);
810 nf_ct_expect_put(exp);
813 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
816 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
817 static inline struct nf_conn *
818 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
820 unsigned int dataoff,
823 struct nf_conntrack_l3proto *l3proto,
824 struct nf_conntrack_l4proto *l4proto,
826 enum ip_conntrack_info *ctinfo)
828 struct nf_conntrack_tuple tuple;
829 struct nf_conntrack_tuple_hash *h;
831 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
834 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
835 dataoff, l3num, protonum, &tuple, l3proto,
837 pr_debug("resolve_normal_ct: Can't get tuple\n");
841 /* look for tuple match */
842 hash = hash_conntrack_raw(&tuple, zone);
843 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
845 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
852 ct = nf_ct_tuplehash_to_ctrack(h);
854 /* It exists; we have (non-exclusive) reference. */
855 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
856 *ctinfo = IP_CT_ESTABLISHED_REPLY;
857 /* Please set reply bit if this packet OK */
860 /* Once we've had two way comms, always ESTABLISHED. */
861 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
862 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
863 *ctinfo = IP_CT_ESTABLISHED;
864 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
865 pr_debug("nf_conntrack_in: related packet for %p\n",
867 *ctinfo = IP_CT_RELATED;
869 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
874 skb->nfct = &ct->ct_general;
875 skb->nfctinfo = *ctinfo;
880 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
883 struct nf_conn *ct, *tmpl = NULL;
884 enum ip_conntrack_info ctinfo;
885 struct nf_conntrack_l3proto *l3proto;
886 struct nf_conntrack_l4proto *l4proto;
887 unsigned int dataoff;
893 /* Previously seen (loopback or untracked)? Ignore. */
894 tmpl = (struct nf_conn *)skb->nfct;
895 if (!nf_ct_is_template(tmpl)) {
896 NF_CT_STAT_INC_ATOMIC(net, ignore);
902 /* rcu_read_lock()ed by nf_hook_slow */
903 l3proto = __nf_ct_l3proto_find(pf);
904 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
905 &dataoff, &protonum);
907 pr_debug("not prepared to track yet or error occurred\n");
908 NF_CT_STAT_INC_ATOMIC(net, error);
909 NF_CT_STAT_INC_ATOMIC(net, invalid);
914 l4proto = __nf_ct_l4proto_find(pf, protonum);
916 /* It may be an special packet, error, unclean...
917 * inverse of the return code tells to the netfilter
918 * core what to do with the packet. */
919 if (l4proto->error != NULL) {
920 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
923 NF_CT_STAT_INC_ATOMIC(net, error);
924 NF_CT_STAT_INC_ATOMIC(net, invalid);
928 /* ICMP[v6] protocol trackers may assign one conntrack. */
933 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
934 l3proto, l4proto, &set_reply, &ctinfo);
936 /* Not valid part of a connection */
937 NF_CT_STAT_INC_ATOMIC(net, invalid);
943 /* Too stressed to deal. */
944 NF_CT_STAT_INC_ATOMIC(net, drop);
949 NF_CT_ASSERT(skb->nfct);
951 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
953 /* Invalid: inverse of the return code tells
954 * the netfilter core what to do */
955 pr_debug("nf_conntrack_in: Can't track with proto module\n");
956 nf_conntrack_put(skb->nfct);
958 NF_CT_STAT_INC_ATOMIC(net, invalid);
960 NF_CT_STAT_INC_ATOMIC(net, drop);
965 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
966 nf_conntrack_event_cache(IPCT_REPLY, ct);
969 /* Special case: we have to repeat this hook, assign the
970 * template again to this packet. We assume that this packet
971 * has no conntrack assigned. This is used by nf_ct_tcp. */
972 if (ret == NF_REPEAT)
973 skb->nfct = (struct nf_conntrack *)tmpl;
980 EXPORT_SYMBOL_GPL(nf_conntrack_in);
982 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
983 const struct nf_conntrack_tuple *orig)
988 ret = nf_ct_invert_tuple(inverse, orig,
989 __nf_ct_l3proto_find(orig->src.l3num),
990 __nf_ct_l4proto_find(orig->src.l3num,
991 orig->dst.protonum));
995 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
997 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
998 implicitly racy: see __nf_conntrack_confirm */
999 void nf_conntrack_alter_reply(struct nf_conn *ct,
1000 const struct nf_conntrack_tuple *newreply)
1002 struct nf_conn_help *help = nfct_help(ct);
1004 /* Should be unconfirmed, so not in hash table yet */
1005 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1007 pr_debug("Altering reply tuple of %p to ", ct);
1008 nf_ct_dump_tuple(newreply);
1010 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1011 if (ct->master || (help && !hlist_empty(&help->expectations)))
1015 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1018 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1020 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1021 void __nf_ct_refresh_acct(struct nf_conn *ct,
1022 enum ip_conntrack_info ctinfo,
1023 const struct sk_buff *skb,
1024 unsigned long extra_jiffies,
1027 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1030 /* Only update if this is not a fixed timeout */
1031 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1034 /* If not in hash table, timer will not be active yet */
1035 if (!nf_ct_is_confirmed(ct)) {
1036 ct->timeout.expires = extra_jiffies;
1038 unsigned long newtime = jiffies + extra_jiffies;
1040 /* Only update the timeout if the new timeout is at least
1041 HZ jiffies from the old timeout. Need del_timer for race
1042 avoidance (may already be dying). */
1043 if (newtime - ct->timeout.expires >= HZ)
1044 mod_timer_pending(&ct->timeout, newtime);
1049 struct nf_conn_counter *acct;
1051 acct = nf_conn_acct_find(ct);
1053 spin_lock_bh(&ct->lock);
1054 acct[CTINFO2DIR(ctinfo)].packets++;
1055 acct[CTINFO2DIR(ctinfo)].bytes += skb->len;
1056 spin_unlock_bh(&ct->lock);
1060 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1062 bool __nf_ct_kill_acct(struct nf_conn *ct,
1063 enum ip_conntrack_info ctinfo,
1064 const struct sk_buff *skb,
1068 struct nf_conn_counter *acct;
1070 acct = nf_conn_acct_find(ct);
1072 spin_lock_bh(&ct->lock);
1073 acct[CTINFO2DIR(ctinfo)].packets++;
1074 acct[CTINFO2DIR(ctinfo)].bytes +=
1075 skb->len - skb_network_offset(skb);
1076 spin_unlock_bh(&ct->lock);
1080 if (del_timer(&ct->timeout)) {
1081 ct->timeout.function((unsigned long)ct);
1086 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1088 #ifdef CONFIG_NF_CONNTRACK_ZONES
1089 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1090 .len = sizeof(struct nf_conntrack_zone),
1091 .align = __alignof__(struct nf_conntrack_zone),
1092 .id = NF_CT_EXT_ZONE,
1096 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1098 #include <linux/netfilter/nfnetlink.h>
1099 #include <linux/netfilter/nfnetlink_conntrack.h>
1100 #include <linux/mutex.h>
1102 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1103 * in ip_conntrack_core, since we don't want the protocols to autoload
1104 * or depend on ctnetlink */
1105 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1106 const struct nf_conntrack_tuple *tuple)
1108 NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
1109 NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
1115 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1117 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1118 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1119 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1121 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1123 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1124 struct nf_conntrack_tuple *t)
1126 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1129 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1130 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1134 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1136 int nf_ct_port_nlattr_tuple_size(void)
1138 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1140 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1143 /* Used by ipt_REJECT and ip6t_REJECT. */
1144 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1147 enum ip_conntrack_info ctinfo;
1149 /* This ICMP is in reverse direction to the packet which caused it */
1150 ct = nf_ct_get(skb, &ctinfo);
1151 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1152 ctinfo = IP_CT_RELATED_REPLY;
1154 ctinfo = IP_CT_RELATED;
1156 /* Attach to new skbuff, and increment count */
1157 nskb->nfct = &ct->ct_general;
1158 nskb->nfctinfo = ctinfo;
1159 nf_conntrack_get(nskb->nfct);
1162 /* Bring out ya dead! */
1163 static struct nf_conn *
1164 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1165 void *data, unsigned int *bucket)
1167 struct nf_conntrack_tuple_hash *h;
1169 struct hlist_nulls_node *n;
1171 spin_lock_bh(&nf_conntrack_lock);
1172 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1173 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1174 ct = nf_ct_tuplehash_to_ctrack(h);
1179 hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
1180 ct = nf_ct_tuplehash_to_ctrack(h);
1182 set_bit(IPS_DYING_BIT, &ct->status);
1184 spin_unlock_bh(&nf_conntrack_lock);
1187 atomic_inc(&ct->ct_general.use);
1188 spin_unlock_bh(&nf_conntrack_lock);
1192 void nf_ct_iterate_cleanup(struct net *net,
1193 int (*iter)(struct nf_conn *i, void *data),
1197 unsigned int bucket = 0;
1199 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1200 /* Time to push up daises... */
1201 if (del_timer(&ct->timeout))
1202 death_by_timeout((unsigned long)ct);
1203 /* ... else the timer will get him soon. */
1208 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1210 struct __nf_ct_flush_report {
1215 static int kill_report(struct nf_conn *i, void *data)
1217 struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1218 struct nf_conn_tstamp *tstamp;
1220 tstamp = nf_conn_tstamp_find(i);
1221 if (tstamp && tstamp->stop == 0)
1222 tstamp->stop = ktime_to_ns(ktime_get_real());
1224 /* If we fail to deliver the event, death_by_timeout() will retry */
1225 if (nf_conntrack_event_report(IPCT_DESTROY, i,
1226 fr->pid, fr->report) < 0)
1229 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1230 set_bit(IPS_DYING_BIT, &i->status);
1234 static int kill_all(struct nf_conn *i, void *data)
1239 void nf_ct_free_hashtable(void *hash, unsigned int size)
1241 if (is_vmalloc_addr(hash))
1244 free_pages((unsigned long)hash,
1245 get_order(sizeof(struct hlist_head) * size));
1247 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1249 void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
1251 struct __nf_ct_flush_report fr = {
1255 nf_ct_iterate_cleanup(net, kill_report, &fr);
1257 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1259 static void nf_ct_release_dying_list(struct net *net)
1261 struct nf_conntrack_tuple_hash *h;
1263 struct hlist_nulls_node *n;
1265 spin_lock_bh(&nf_conntrack_lock);
1266 hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
1267 ct = nf_ct_tuplehash_to_ctrack(h);
1268 /* never fails to remove them, no listeners at this point */
1271 spin_unlock_bh(&nf_conntrack_lock);
1274 static int untrack_refs(void)
1278 for_each_possible_cpu(cpu) {
1279 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1281 cnt += atomic_read(&ct->ct_general.use) - 1;
1286 static void nf_conntrack_cleanup_init_net(void)
1288 while (untrack_refs() > 0)
1291 nf_conntrack_helper_fini();
1292 nf_conntrack_proto_fini();
1293 #ifdef CONFIG_NF_CONNTRACK_ZONES
1294 nf_ct_extend_unregister(&nf_ct_zone_extend);
1298 static void nf_conntrack_cleanup_net(struct net *net)
1301 nf_ct_iterate_cleanup(net, kill_all, NULL);
1302 nf_ct_release_dying_list(net);
1303 if (atomic_read(&net->ct.count) != 0) {
1305 goto i_see_dead_people;
1308 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1309 nf_conntrack_ecache_fini(net);
1310 nf_conntrack_tstamp_fini(net);
1311 nf_conntrack_acct_fini(net);
1312 nf_conntrack_expect_fini(net);
1313 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1314 kfree(net->ct.slabname);
1315 free_percpu(net->ct.stat);
1318 /* Mishearing the voices in his head, our hero wonders how he's
1319 supposed to kill the mall. */
1320 void nf_conntrack_cleanup(struct net *net)
1322 if (net_eq(net, &init_net))
1323 RCU_INIT_POINTER(ip_ct_attach, NULL);
1325 /* This makes sure all current packets have passed through
1326 netfilter framework. Roll on, two-stage module
1330 nf_conntrack_cleanup_net(net);
1332 if (net_eq(net, &init_net)) {
1333 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1334 nf_conntrack_cleanup_init_net();
1338 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1340 struct hlist_nulls_head *hash;
1341 unsigned int nr_slots, i;
1344 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1345 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1346 sz = nr_slots * sizeof(struct hlist_nulls_head);
1347 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1350 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1351 hash = __vmalloc(sz, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1356 for (i = 0; i < nr_slots; i++)
1357 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1361 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1363 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1366 unsigned int hashsize, old_size;
1367 struct hlist_nulls_head *hash, *old_hash;
1368 struct nf_conntrack_tuple_hash *h;
1371 if (current->nsproxy->net_ns != &init_net)
1374 /* On boot, we can set this without any fancy locking. */
1375 if (!nf_conntrack_htable_size)
1376 return param_set_uint(val, kp);
1378 hashsize = simple_strtoul(val, NULL, 0);
1382 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1386 /* Lookups in the old hash might happen in parallel, which means we
1387 * might get false negatives during connection lookup. New connections
1388 * created because of a false negative won't make it into the hash
1389 * though since that required taking the lock.
1391 spin_lock_bh(&nf_conntrack_lock);
1392 for (i = 0; i < init_net.ct.htable_size; i++) {
1393 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1394 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1395 struct nf_conntrack_tuple_hash, hnnode);
1396 ct = nf_ct_tuplehash_to_ctrack(h);
1397 hlist_nulls_del_rcu(&h->hnnode);
1398 bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1400 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1403 old_size = init_net.ct.htable_size;
1404 old_hash = init_net.ct.hash;
1406 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1407 init_net.ct.hash = hash;
1408 spin_unlock_bh(&nf_conntrack_lock);
1410 nf_ct_free_hashtable(old_hash, old_size);
1413 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1415 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1416 &nf_conntrack_htable_size, 0600);
1418 void nf_ct_untracked_status_or(unsigned long bits)
1422 for_each_possible_cpu(cpu)
1423 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1425 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1427 static int nf_conntrack_init_init_net(void)
1432 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1433 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1434 if (!nf_conntrack_htable_size) {
1435 nf_conntrack_htable_size
1436 = (((totalram_pages << PAGE_SHIFT) / 16384)
1437 / sizeof(struct hlist_head));
1438 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1439 nf_conntrack_htable_size = 16384;
1440 if (nf_conntrack_htable_size < 32)
1441 nf_conntrack_htable_size = 32;
1443 /* Use a max. factor of four by default to get the same max as
1444 * with the old struct list_heads. When a table size is given
1445 * we use the old value of 8 to avoid reducing the max.
1449 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1451 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1452 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1455 ret = nf_conntrack_proto_init();
1459 ret = nf_conntrack_helper_init();
1463 #ifdef CONFIG_NF_CONNTRACK_ZONES
1464 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1468 /* Set up fake conntrack: to never be deleted, not in any hashes */
1469 for_each_possible_cpu(cpu) {
1470 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1471 write_pnet(&ct->ct_net, &init_net);
1472 atomic_set(&ct->ct_general.use, 1);
1474 /* - and look it like as a confirmed connection */
1475 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1478 #ifdef CONFIG_NF_CONNTRACK_ZONES
1480 nf_conntrack_helper_fini();
1483 nf_conntrack_proto_fini();
1489 * We need to use special "null" values, not used in hash table
1491 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1492 #define DYING_NULLS_VAL ((1<<30)+1)
1494 static int nf_conntrack_init_net(struct net *net)
1498 atomic_set(&net->ct.count, 0);
1499 INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
1500 INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
1501 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1502 if (!net->ct.stat) {
1507 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1508 if (!net->ct.slabname) {
1513 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1514 sizeof(struct nf_conn), 0,
1515 SLAB_DESTROY_BY_RCU, NULL);
1516 if (!net->ct.nf_conntrack_cachep) {
1517 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1522 net->ct.htable_size = nf_conntrack_htable_size;
1523 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1524 if (!net->ct.hash) {
1526 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1529 ret = nf_conntrack_expect_init(net);
1532 ret = nf_conntrack_acct_init(net);
1535 ret = nf_conntrack_tstamp_init(net);
1538 ret = nf_conntrack_ecache_init(net);
1545 nf_conntrack_tstamp_fini(net);
1547 nf_conntrack_acct_fini(net);
1549 nf_conntrack_expect_fini(net);
1551 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1553 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1555 kfree(net->ct.slabname);
1557 free_percpu(net->ct.stat);
1562 s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
1563 enum ip_conntrack_dir dir,
1565 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
1567 int nf_conntrack_init(struct net *net)
1571 if (net_eq(net, &init_net)) {
1572 ret = nf_conntrack_init_init_net();
1576 ret = nf_conntrack_init_net(net);
1580 if (net_eq(net, &init_net)) {
1581 /* For use by REJECT target */
1582 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1583 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1585 /* Howto get NAT offsets */
1586 RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
1591 if (net_eq(net, &init_net))
1592 nf_conntrack_cleanup_init_net();