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_conntrack_timeout.h>
48 #include <net/netfilter/nf_nat.h>
49 #include <net/netfilter/nf_nat_core.h>
51 #define NF_CONNTRACK_VERSION "0.5.0"
53 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
54 enum nf_nat_manip_type manip,
55 const struct nlattr *attr) __read_mostly;
56 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
58 int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
60 enum ip_conntrack_info ctinfo,
61 unsigned int protoff);
62 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
64 DEFINE_SPINLOCK(nf_conntrack_lock);
65 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
67 unsigned int nf_conntrack_htable_size __read_mostly;
68 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
70 unsigned int nf_conntrack_max __read_mostly;
71 EXPORT_SYMBOL_GPL(nf_conntrack_max);
73 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
74 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
76 unsigned int nf_conntrack_hash_rnd __read_mostly;
77 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
79 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
83 /* The direction must be ignored, so we hash everything up to the
84 * destination ports (which is a multiple of 4) and treat the last
85 * three bytes manually.
87 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
88 return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
89 (((__force __u16)tuple->dst.u.all << 16) |
90 tuple->dst.protonum));
93 static u32 __hash_bucket(u32 hash, unsigned int size)
95 return ((u64)hash * size) >> 32;
98 static u32 hash_bucket(u32 hash, const struct net *net)
100 return __hash_bucket(hash, net->ct.htable_size);
103 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
104 u16 zone, unsigned int size)
106 return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
109 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
110 const struct nf_conntrack_tuple *tuple)
112 return __hash_conntrack(tuple, zone, net->ct.htable_size);
116 nf_ct_get_tuple(const struct sk_buff *skb,
118 unsigned int dataoff,
121 struct nf_conntrack_tuple *tuple,
122 const struct nf_conntrack_l3proto *l3proto,
123 const struct nf_conntrack_l4proto *l4proto)
125 memset(tuple, 0, sizeof(*tuple));
127 tuple->src.l3num = l3num;
128 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
131 tuple->dst.protonum = protonum;
132 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
134 return l4proto->pkt_to_tuple(skb, dataoff, tuple);
136 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
138 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
139 u_int16_t l3num, struct nf_conntrack_tuple *tuple)
141 struct nf_conntrack_l3proto *l3proto;
142 struct nf_conntrack_l4proto *l4proto;
143 unsigned int protoff;
149 l3proto = __nf_ct_l3proto_find(l3num);
150 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
151 if (ret != NF_ACCEPT) {
156 l4proto = __nf_ct_l4proto_find(l3num, protonum);
158 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
164 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
167 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
168 const struct nf_conntrack_tuple *orig,
169 const struct nf_conntrack_l3proto *l3proto,
170 const struct nf_conntrack_l4proto *l4proto)
172 memset(inverse, 0, sizeof(*inverse));
174 inverse->src.l3num = orig->src.l3num;
175 if (l3proto->invert_tuple(inverse, orig) == 0)
178 inverse->dst.dir = !orig->dst.dir;
180 inverse->dst.protonum = orig->dst.protonum;
181 return l4proto->invert_tuple(inverse, orig);
183 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
186 clean_from_lists(struct nf_conn *ct)
188 pr_debug("clean_from_lists(%p)\n", ct);
189 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
190 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
192 /* Destroy all pending expectations */
193 nf_ct_remove_expectations(ct);
197 destroy_conntrack(struct nf_conntrack *nfct)
199 struct nf_conn *ct = (struct nf_conn *)nfct;
200 struct net *net = nf_ct_net(ct);
201 struct nf_conntrack_l4proto *l4proto;
203 pr_debug("destroy_conntrack(%p)\n", ct);
204 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
205 NF_CT_ASSERT(!timer_pending(&ct->timeout));
207 /* To make sure we don't get any weird locking issues here:
208 * destroy_conntrack() MUST NOT be called with a write lock
209 * to nf_conntrack_lock!!! -HW */
211 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
212 if (l4proto && l4proto->destroy)
213 l4proto->destroy(ct);
217 spin_lock_bh(&nf_conntrack_lock);
218 /* Expectations will have been removed in clean_from_lists,
219 * except TFTP can create an expectation on the first packet,
220 * before connection is in the list, so we need to clean here,
222 nf_ct_remove_expectations(ct);
224 /* We overload first tuple to link into unconfirmed list. */
225 if (!nf_ct_is_confirmed(ct)) {
226 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
227 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
230 NF_CT_STAT_INC(net, delete);
231 spin_unlock_bh(&nf_conntrack_lock);
234 nf_ct_put(ct->master);
236 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
237 nf_conntrack_free(ct);
240 void nf_ct_delete_from_lists(struct nf_conn *ct)
242 struct net *net = nf_ct_net(ct);
244 nf_ct_helper_destroy(ct);
245 spin_lock_bh(&nf_conntrack_lock);
246 /* Inside lock so preempt is disabled on module removal path.
247 * Otherwise we can get spurious warnings. */
248 NF_CT_STAT_INC(net, delete_list);
249 clean_from_lists(ct);
250 spin_unlock_bh(&nf_conntrack_lock);
252 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
254 static void death_by_event(unsigned long ul_conntrack)
256 struct nf_conn *ct = (void *)ul_conntrack;
257 struct net *net = nf_ct_net(ct);
258 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
260 BUG_ON(ecache == NULL);
262 if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
263 /* bad luck, let's retry again */
264 ecache->timeout.expires = jiffies +
265 (random32() % net->ct.sysctl_events_retry_timeout);
266 add_timer(&ecache->timeout);
269 /* we've got the event delivered, now it's dying */
270 set_bit(IPS_DYING_BIT, &ct->status);
271 spin_lock(&nf_conntrack_lock);
272 hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
273 spin_unlock(&nf_conntrack_lock);
277 void nf_ct_insert_dying_list(struct nf_conn *ct)
279 struct net *net = nf_ct_net(ct);
280 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
282 BUG_ON(ecache == NULL);
284 /* add this conntrack to the dying list */
285 spin_lock_bh(&nf_conntrack_lock);
286 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
288 spin_unlock_bh(&nf_conntrack_lock);
289 /* set a new timer to retry event delivery */
290 setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
291 ecache->timeout.expires = jiffies +
292 (random32() % net->ct.sysctl_events_retry_timeout);
293 add_timer(&ecache->timeout);
295 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
297 static void death_by_timeout(unsigned long ul_conntrack)
299 struct nf_conn *ct = (void *)ul_conntrack;
300 struct nf_conn_tstamp *tstamp;
302 tstamp = nf_conn_tstamp_find(ct);
303 if (tstamp && tstamp->stop == 0)
304 tstamp->stop = ktime_to_ns(ktime_get_real());
306 if (!test_bit(IPS_DYING_BIT, &ct->status) &&
307 unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
308 /* destroy event was not delivered */
309 nf_ct_delete_from_lists(ct);
310 nf_ct_insert_dying_list(ct);
313 set_bit(IPS_DYING_BIT, &ct->status);
314 nf_ct_delete_from_lists(ct);
320 * - Caller must take a reference on returned object
321 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
323 * - Caller must lock nf_conntrack_lock before calling this function
325 static struct nf_conntrack_tuple_hash *
326 ____nf_conntrack_find(struct net *net, u16 zone,
327 const struct nf_conntrack_tuple *tuple, u32 hash)
329 struct nf_conntrack_tuple_hash *h;
330 struct hlist_nulls_node *n;
331 unsigned int bucket = hash_bucket(hash, net);
333 /* Disable BHs the entire time since we normally need to disable them
334 * at least once for the stats anyway.
338 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
339 if (nf_ct_tuple_equal(tuple, &h->tuple) &&
340 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
341 NF_CT_STAT_INC(net, found);
345 NF_CT_STAT_INC(net, searched);
348 * if the nulls value we got at the end of this lookup is
349 * not the expected one, we must restart lookup.
350 * We probably met an item that was moved to another chain.
352 if (get_nulls_value(n) != bucket) {
353 NF_CT_STAT_INC(net, search_restart);
361 struct nf_conntrack_tuple_hash *
362 __nf_conntrack_find(struct net *net, u16 zone,
363 const struct nf_conntrack_tuple *tuple)
365 return ____nf_conntrack_find(net, zone, tuple,
366 hash_conntrack_raw(tuple, zone));
368 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
370 /* Find a connection corresponding to a tuple. */
371 static struct nf_conntrack_tuple_hash *
372 __nf_conntrack_find_get(struct net *net, u16 zone,
373 const struct nf_conntrack_tuple *tuple, u32 hash)
375 struct nf_conntrack_tuple_hash *h;
380 h = ____nf_conntrack_find(net, zone, tuple, hash);
382 ct = nf_ct_tuplehash_to_ctrack(h);
383 if (unlikely(nf_ct_is_dying(ct) ||
384 !atomic_inc_not_zero(&ct->ct_general.use)))
387 if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
388 nf_ct_zone(ct) != zone)) {
399 struct nf_conntrack_tuple_hash *
400 nf_conntrack_find_get(struct net *net, u16 zone,
401 const struct nf_conntrack_tuple *tuple)
403 return __nf_conntrack_find_get(net, zone, tuple,
404 hash_conntrack_raw(tuple, zone));
406 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
408 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
410 unsigned int repl_hash)
412 struct net *net = nf_ct_net(ct);
414 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
415 &net->ct.hash[hash]);
416 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
417 &net->ct.hash[repl_hash]);
421 nf_conntrack_hash_check_insert(struct nf_conn *ct)
423 struct net *net = nf_ct_net(ct);
424 unsigned int hash, repl_hash;
425 struct nf_conntrack_tuple_hash *h;
426 struct hlist_nulls_node *n;
429 zone = nf_ct_zone(ct);
430 hash = hash_conntrack(net, zone,
431 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
432 repl_hash = hash_conntrack(net, zone,
433 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
435 spin_lock_bh(&nf_conntrack_lock);
437 /* See if there's one in the list already, including reverse */
438 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
439 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
441 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
443 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
444 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
446 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
449 add_timer(&ct->timeout);
450 nf_conntrack_get(&ct->ct_general);
451 __nf_conntrack_hash_insert(ct, hash, repl_hash);
452 NF_CT_STAT_INC(net, insert);
453 spin_unlock_bh(&nf_conntrack_lock);
458 NF_CT_STAT_INC(net, insert_failed);
459 spin_unlock_bh(&nf_conntrack_lock);
462 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
464 /* Confirm a connection given skb; places it in hash table */
466 __nf_conntrack_confirm(struct sk_buff *skb)
468 unsigned int hash, repl_hash;
469 struct nf_conntrack_tuple_hash *h;
471 struct nf_conn_help *help;
472 struct nf_conn_tstamp *tstamp;
473 struct hlist_nulls_node *n;
474 enum ip_conntrack_info ctinfo;
478 ct = nf_ct_get(skb, &ctinfo);
481 /* ipt_REJECT uses nf_conntrack_attach to attach related
482 ICMP/TCP RST packets in other direction. Actual packet
483 which created connection will be IP_CT_NEW or for an
484 expected connection, IP_CT_RELATED. */
485 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
488 zone = nf_ct_zone(ct);
489 /* reuse the hash saved before */
490 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
491 hash = hash_bucket(hash, net);
492 repl_hash = hash_conntrack(net, zone,
493 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
495 /* We're not in hash table, and we refuse to set up related
496 connections for unconfirmed conns. But packet copies and
497 REJECT will give spurious warnings here. */
498 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
500 /* No external references means no one else could have
502 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
503 pr_debug("Confirming conntrack %p\n", ct);
505 spin_lock_bh(&nf_conntrack_lock);
507 /* We have to check the DYING flag inside the lock to prevent
508 a race against nf_ct_get_next_corpse() possibly called from
509 user context, else we insert an already 'dead' hash, blocking
510 further use of that particular connection -JM */
512 if (unlikely(nf_ct_is_dying(ct))) {
513 spin_unlock_bh(&nf_conntrack_lock);
517 /* See if there's one in the list already, including reverse:
518 NAT could have grabbed it without realizing, since we're
519 not in the hash. If there is, we lost race. */
520 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
521 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
523 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
525 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
526 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
528 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
531 /* Remove from unconfirmed list */
532 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
534 /* Timer relative to confirmation time, not original
535 setting time, otherwise we'd get timer wrap in
536 weird delay cases. */
537 ct->timeout.expires += jiffies;
538 add_timer(&ct->timeout);
539 atomic_inc(&ct->ct_general.use);
540 ct->status |= IPS_CONFIRMED;
542 /* set conntrack timestamp, if enabled. */
543 tstamp = nf_conn_tstamp_find(ct);
545 if (skb->tstamp.tv64 == 0)
546 __net_timestamp(skb);
548 tstamp->start = ktime_to_ns(skb->tstamp);
550 /* Since the lookup is lockless, hash insertion must be done after
551 * starting the timer and setting the CONFIRMED bit. The RCU barriers
552 * guarantee that no other CPU can find the conntrack before the above
553 * stores are visible.
555 __nf_conntrack_hash_insert(ct, hash, repl_hash);
556 NF_CT_STAT_INC(net, insert);
557 spin_unlock_bh(&nf_conntrack_lock);
559 help = nfct_help(ct);
560 if (help && help->helper)
561 nf_conntrack_event_cache(IPCT_HELPER, ct);
563 nf_conntrack_event_cache(master_ct(ct) ?
564 IPCT_RELATED : IPCT_NEW, ct);
568 NF_CT_STAT_INC(net, insert_failed);
569 spin_unlock_bh(&nf_conntrack_lock);
572 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
574 /* Returns true if a connection correspondings to the tuple (required
577 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
578 const struct nf_conn *ignored_conntrack)
580 struct net *net = nf_ct_net(ignored_conntrack);
581 struct nf_conntrack_tuple_hash *h;
582 struct hlist_nulls_node *n;
584 u16 zone = nf_ct_zone(ignored_conntrack);
585 unsigned int hash = hash_conntrack(net, zone, tuple);
587 /* Disable BHs the entire time since we need to disable them at
588 * least once for the stats anyway.
591 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
592 ct = nf_ct_tuplehash_to_ctrack(h);
593 if (ct != ignored_conntrack &&
594 nf_ct_tuple_equal(tuple, &h->tuple) &&
595 nf_ct_zone(ct) == zone) {
596 NF_CT_STAT_INC(net, found);
597 rcu_read_unlock_bh();
600 NF_CT_STAT_INC(net, searched);
602 rcu_read_unlock_bh();
606 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
608 #define NF_CT_EVICTION_RANGE 8
610 /* There's a small race here where we may free a just-assured
611 connection. Too bad: we're in trouble anyway. */
612 static noinline int early_drop(struct net *net, unsigned int hash)
614 /* Use oldest entry, which is roughly LRU */
615 struct nf_conntrack_tuple_hash *h;
616 struct nf_conn *ct = NULL, *tmp;
617 struct hlist_nulls_node *n;
618 unsigned int i, cnt = 0;
622 for (i = 0; i < net->ct.htable_size; i++) {
623 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
625 tmp = nf_ct_tuplehash_to_ctrack(h);
626 if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
632 if (likely(!nf_ct_is_dying(ct) &&
633 atomic_inc_not_zero(&ct->ct_general.use)))
639 if (cnt >= NF_CT_EVICTION_RANGE)
642 hash = (hash + 1) % net->ct.htable_size;
649 if (del_timer(&ct->timeout)) {
650 death_by_timeout((unsigned long)ct);
651 /* Check if we indeed killed this entry. Reliable event
652 delivery may have inserted it into the dying list. */
653 if (test_bit(IPS_DYING_BIT, &ct->status)) {
655 NF_CT_STAT_INC_ATOMIC(net, early_drop);
662 void init_nf_conntrack_hash_rnd(void)
667 * Why not initialize nf_conntrack_rnd in a "init()" function ?
668 * Because there isn't enough entropy when system initializing,
669 * and we initialize it as late as possible.
672 get_random_bytes(&rand, sizeof(rand));
674 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
677 static struct nf_conn *
678 __nf_conntrack_alloc(struct net *net, u16 zone,
679 const struct nf_conntrack_tuple *orig,
680 const struct nf_conntrack_tuple *repl,
685 if (unlikely(!nf_conntrack_hash_rnd)) {
686 init_nf_conntrack_hash_rnd();
687 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
688 hash = hash_conntrack_raw(orig, zone);
691 /* We don't want any race condition at early drop stage */
692 atomic_inc(&net->ct.count);
694 if (nf_conntrack_max &&
695 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
696 if (!early_drop(net, hash_bucket(hash, net))) {
697 atomic_dec(&net->ct.count);
698 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
699 return ERR_PTR(-ENOMEM);
704 * Do not use kmem_cache_zalloc(), as this cache uses
705 * SLAB_DESTROY_BY_RCU.
707 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
709 atomic_dec(&net->ct.count);
710 return ERR_PTR(-ENOMEM);
713 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
714 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
716 memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
717 offsetof(struct nf_conn, proto) -
718 offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
719 spin_lock_init(&ct->lock);
720 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
721 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
722 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
723 /* save hash for reusing when confirming */
724 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
725 /* Don't set timer yet: wait for confirmation */
726 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
727 write_pnet(&ct->ct_net, net);
728 #ifdef CONFIG_NF_CONNTRACK_ZONES
730 struct nf_conntrack_zone *nf_ct_zone;
732 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
735 nf_ct_zone->id = zone;
739 * changes to lookup keys must be done before setting refcnt to 1
742 atomic_set(&ct->ct_general.use, 1);
745 #ifdef CONFIG_NF_CONNTRACK_ZONES
747 atomic_dec(&net->ct.count);
748 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
749 return ERR_PTR(-ENOMEM);
753 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
754 const struct nf_conntrack_tuple *orig,
755 const struct nf_conntrack_tuple *repl,
758 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
760 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
762 void nf_conntrack_free(struct nf_conn *ct)
764 struct net *net = nf_ct_net(ct);
766 nf_ct_ext_destroy(ct);
767 atomic_dec(&net->ct.count);
769 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
771 EXPORT_SYMBOL_GPL(nf_conntrack_free);
773 /* Allocate a new conntrack: we return -ENOMEM if classification
774 failed due to stress. Otherwise it really is unclassifiable. */
775 static struct nf_conntrack_tuple_hash *
776 init_conntrack(struct net *net, struct nf_conn *tmpl,
777 const struct nf_conntrack_tuple *tuple,
778 struct nf_conntrack_l3proto *l3proto,
779 struct nf_conntrack_l4proto *l4proto,
781 unsigned int dataoff, u32 hash)
784 struct nf_conn_help *help;
785 struct nf_conntrack_tuple repl_tuple;
786 struct nf_conntrack_ecache *ecache;
787 struct nf_conntrack_expect *exp;
788 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
789 struct nf_conn_timeout *timeout_ext;
790 unsigned int *timeouts;
792 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
793 pr_debug("Can't invert tuple.\n");
797 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
800 return (struct nf_conntrack_tuple_hash *)ct;
802 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
804 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
806 timeouts = l4proto->get_timeouts(net);
808 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
809 nf_conntrack_free(ct);
810 pr_debug("init conntrack: can't track with proto module\n");
815 nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);
817 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
818 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
820 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
821 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
822 ecache ? ecache->expmask : 0,
825 spin_lock_bh(&nf_conntrack_lock);
826 exp = nf_ct_find_expectation(net, zone, tuple);
828 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
830 /* Welcome, Mr. Bond. We've been expecting you... */
831 __set_bit(IPS_EXPECTED_BIT, &ct->status);
832 ct->master = exp->master;
834 help = nf_ct_helper_ext_add(ct, exp->helper,
837 rcu_assign_pointer(help->helper, exp->helper);
840 #ifdef CONFIG_NF_CONNTRACK_MARK
841 ct->mark = exp->master->mark;
843 #ifdef CONFIG_NF_CONNTRACK_SECMARK
844 ct->secmark = exp->master->secmark;
846 nf_conntrack_get(&ct->master->ct_general);
847 NF_CT_STAT_INC(net, expect_new);
849 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
850 NF_CT_STAT_INC(net, new);
853 /* Overload tuple linked list to put us in unconfirmed list. */
854 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
855 &net->ct.unconfirmed);
857 spin_unlock_bh(&nf_conntrack_lock);
861 exp->expectfn(ct, exp);
862 nf_ct_expect_put(exp);
865 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
868 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
869 static inline struct nf_conn *
870 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
872 unsigned int dataoff,
875 struct nf_conntrack_l3proto *l3proto,
876 struct nf_conntrack_l4proto *l4proto,
878 enum ip_conntrack_info *ctinfo)
880 struct nf_conntrack_tuple tuple;
881 struct nf_conntrack_tuple_hash *h;
883 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
886 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
887 dataoff, l3num, protonum, &tuple, l3proto,
889 pr_debug("resolve_normal_ct: Can't get tuple\n");
893 /* look for tuple match */
894 hash = hash_conntrack_raw(&tuple, zone);
895 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
897 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
904 ct = nf_ct_tuplehash_to_ctrack(h);
906 /* It exists; we have (non-exclusive) reference. */
907 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
908 *ctinfo = IP_CT_ESTABLISHED_REPLY;
909 /* Please set reply bit if this packet OK */
912 /* Once we've had two way comms, always ESTABLISHED. */
913 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
914 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
915 *ctinfo = IP_CT_ESTABLISHED;
916 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
917 pr_debug("nf_conntrack_in: related packet for %p\n",
919 *ctinfo = IP_CT_RELATED;
921 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
926 skb->nfct = &ct->ct_general;
927 skb->nfctinfo = *ctinfo;
932 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
935 struct nf_conn *ct, *tmpl = NULL;
936 enum ip_conntrack_info ctinfo;
937 struct nf_conntrack_l3proto *l3proto;
938 struct nf_conntrack_l4proto *l4proto;
939 unsigned int *timeouts;
940 unsigned int dataoff;
946 /* Previously seen (loopback or untracked)? Ignore. */
947 tmpl = (struct nf_conn *)skb->nfct;
948 if (!nf_ct_is_template(tmpl)) {
949 NF_CT_STAT_INC_ATOMIC(net, ignore);
955 /* rcu_read_lock()ed by nf_hook_slow */
956 l3proto = __nf_ct_l3proto_find(pf);
957 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
958 &dataoff, &protonum);
960 pr_debug("not prepared to track yet or error occurred\n");
961 NF_CT_STAT_INC_ATOMIC(net, error);
962 NF_CT_STAT_INC_ATOMIC(net, invalid);
967 l4proto = __nf_ct_l4proto_find(pf, protonum);
969 /* It may be an special packet, error, unclean...
970 * inverse of the return code tells to the netfilter
971 * core what to do with the packet. */
972 if (l4proto->error != NULL) {
973 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
976 NF_CT_STAT_INC_ATOMIC(net, error);
977 NF_CT_STAT_INC_ATOMIC(net, invalid);
981 /* ICMP[v6] protocol trackers may assign one conntrack. */
986 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
987 l3proto, l4proto, &set_reply, &ctinfo);
989 /* Not valid part of a connection */
990 NF_CT_STAT_INC_ATOMIC(net, invalid);
996 /* Too stressed to deal. */
997 NF_CT_STAT_INC_ATOMIC(net, drop);
1002 NF_CT_ASSERT(skb->nfct);
1004 /* Decide what timeout policy we want to apply to this flow. */
1005 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1007 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1009 /* Invalid: inverse of the return code tells
1010 * the netfilter core what to do */
1011 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1012 nf_conntrack_put(skb->nfct);
1014 NF_CT_STAT_INC_ATOMIC(net, invalid);
1015 if (ret == -NF_DROP)
1016 NF_CT_STAT_INC_ATOMIC(net, drop);
1021 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1022 nf_conntrack_event_cache(IPCT_REPLY, ct);
1025 /* Special case: we have to repeat this hook, assign the
1026 * template again to this packet. We assume that this packet
1027 * has no conntrack assigned. This is used by nf_ct_tcp. */
1028 if (ret == NF_REPEAT)
1029 skb->nfct = (struct nf_conntrack *)tmpl;
1036 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1038 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1039 const struct nf_conntrack_tuple *orig)
1044 ret = nf_ct_invert_tuple(inverse, orig,
1045 __nf_ct_l3proto_find(orig->src.l3num),
1046 __nf_ct_l4proto_find(orig->src.l3num,
1047 orig->dst.protonum));
1051 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1053 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1054 implicitly racy: see __nf_conntrack_confirm */
1055 void nf_conntrack_alter_reply(struct nf_conn *ct,
1056 const struct nf_conntrack_tuple *newreply)
1058 struct nf_conn_help *help = nfct_help(ct);
1060 /* Should be unconfirmed, so not in hash table yet */
1061 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1063 pr_debug("Altering reply tuple of %p to ", ct);
1064 nf_ct_dump_tuple(newreply);
1066 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1067 if (ct->master || (help && !hlist_empty(&help->expectations)))
1071 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1074 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1076 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1077 void __nf_ct_refresh_acct(struct nf_conn *ct,
1078 enum ip_conntrack_info ctinfo,
1079 const struct sk_buff *skb,
1080 unsigned long extra_jiffies,
1083 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1086 /* Only update if this is not a fixed timeout */
1087 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1090 /* If not in hash table, timer will not be active yet */
1091 if (!nf_ct_is_confirmed(ct)) {
1092 ct->timeout.expires = extra_jiffies;
1094 unsigned long newtime = jiffies + extra_jiffies;
1096 /* Only update the timeout if the new timeout is at least
1097 HZ jiffies from the old timeout. Need del_timer for race
1098 avoidance (may already be dying). */
1099 if (newtime - ct->timeout.expires >= HZ)
1100 mod_timer_pending(&ct->timeout, newtime);
1105 struct nf_conn_counter *acct;
1107 acct = nf_conn_acct_find(ct);
1109 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1110 atomic64_add(skb->len, &acct[CTINFO2DIR(ctinfo)].bytes);
1114 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1116 bool __nf_ct_kill_acct(struct nf_conn *ct,
1117 enum ip_conntrack_info ctinfo,
1118 const struct sk_buff *skb,
1122 struct nf_conn_counter *acct;
1124 acct = nf_conn_acct_find(ct);
1126 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1127 atomic64_add(skb->len - skb_network_offset(skb),
1128 &acct[CTINFO2DIR(ctinfo)].bytes);
1132 if (del_timer(&ct->timeout)) {
1133 ct->timeout.function((unsigned long)ct);
1138 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1140 #ifdef CONFIG_NF_CONNTRACK_ZONES
1141 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1142 .len = sizeof(struct nf_conntrack_zone),
1143 .align = __alignof__(struct nf_conntrack_zone),
1144 .id = NF_CT_EXT_ZONE,
1148 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1150 #include <linux/netfilter/nfnetlink.h>
1151 #include <linux/netfilter/nfnetlink_conntrack.h>
1152 #include <linux/mutex.h>
1154 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1155 * in ip_conntrack_core, since we don't want the protocols to autoload
1156 * or depend on ctnetlink */
1157 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1158 const struct nf_conntrack_tuple *tuple)
1160 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1161 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1162 goto nla_put_failure;
1168 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1170 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1171 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1172 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1174 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1176 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1177 struct nf_conntrack_tuple *t)
1179 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1182 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1183 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1187 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1189 int nf_ct_port_nlattr_tuple_size(void)
1191 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1193 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1196 /* Used by ipt_REJECT and ip6t_REJECT. */
1197 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1200 enum ip_conntrack_info ctinfo;
1202 /* This ICMP is in reverse direction to the packet which caused it */
1203 ct = nf_ct_get(skb, &ctinfo);
1204 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1205 ctinfo = IP_CT_RELATED_REPLY;
1207 ctinfo = IP_CT_RELATED;
1209 /* Attach to new skbuff, and increment count */
1210 nskb->nfct = &ct->ct_general;
1211 nskb->nfctinfo = ctinfo;
1212 nf_conntrack_get(nskb->nfct);
1215 /* Bring out ya dead! */
1216 static struct nf_conn *
1217 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1218 void *data, unsigned int *bucket)
1220 struct nf_conntrack_tuple_hash *h;
1222 struct hlist_nulls_node *n;
1224 spin_lock_bh(&nf_conntrack_lock);
1225 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1226 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1227 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1229 ct = nf_ct_tuplehash_to_ctrack(h);
1234 hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
1235 ct = nf_ct_tuplehash_to_ctrack(h);
1237 set_bit(IPS_DYING_BIT, &ct->status);
1239 spin_unlock_bh(&nf_conntrack_lock);
1242 atomic_inc(&ct->ct_general.use);
1243 spin_unlock_bh(&nf_conntrack_lock);
1247 void nf_ct_iterate_cleanup(struct net *net,
1248 int (*iter)(struct nf_conn *i, void *data),
1252 unsigned int bucket = 0;
1254 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1255 /* Time to push up daises... */
1256 if (del_timer(&ct->timeout))
1257 death_by_timeout((unsigned long)ct);
1258 /* ... else the timer will get him soon. */
1263 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1265 struct __nf_ct_flush_report {
1270 static int kill_report(struct nf_conn *i, void *data)
1272 struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1273 struct nf_conn_tstamp *tstamp;
1275 tstamp = nf_conn_tstamp_find(i);
1276 if (tstamp && tstamp->stop == 0)
1277 tstamp->stop = ktime_to_ns(ktime_get_real());
1279 /* If we fail to deliver the event, death_by_timeout() will retry */
1280 if (nf_conntrack_event_report(IPCT_DESTROY, i,
1281 fr->pid, fr->report) < 0)
1284 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1285 set_bit(IPS_DYING_BIT, &i->status);
1289 static int kill_all(struct nf_conn *i, void *data)
1294 void nf_ct_free_hashtable(void *hash, unsigned int size)
1296 if (is_vmalloc_addr(hash))
1299 free_pages((unsigned long)hash,
1300 get_order(sizeof(struct hlist_head) * size));
1302 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1304 void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
1306 struct __nf_ct_flush_report fr = {
1310 nf_ct_iterate_cleanup(net, kill_report, &fr);
1312 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1314 static void nf_ct_release_dying_list(struct net *net)
1316 struct nf_conntrack_tuple_hash *h;
1318 struct hlist_nulls_node *n;
1320 spin_lock_bh(&nf_conntrack_lock);
1321 hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
1322 ct = nf_ct_tuplehash_to_ctrack(h);
1323 /* never fails to remove them, no listeners at this point */
1326 spin_unlock_bh(&nf_conntrack_lock);
1329 static int untrack_refs(void)
1333 for_each_possible_cpu(cpu) {
1334 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1336 cnt += atomic_read(&ct->ct_general.use) - 1;
1341 static void nf_conntrack_cleanup_init_net(void)
1343 while (untrack_refs() > 0)
1346 #ifdef CONFIG_NF_CONNTRACK_ZONES
1347 nf_ct_extend_unregister(&nf_ct_zone_extend);
1351 static void nf_conntrack_cleanup_net(struct net *net)
1354 nf_ct_iterate_cleanup(net, kill_all, NULL);
1355 nf_ct_release_dying_list(net);
1356 if (atomic_read(&net->ct.count) != 0) {
1358 goto i_see_dead_people;
1361 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1362 nf_conntrack_helper_fini(net);
1363 nf_conntrack_timeout_fini(net);
1364 nf_conntrack_ecache_fini(net);
1365 nf_conntrack_tstamp_fini(net);
1366 nf_conntrack_acct_fini(net);
1367 nf_conntrack_expect_fini(net);
1368 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1369 kfree(net->ct.slabname);
1370 free_percpu(net->ct.stat);
1373 /* Mishearing the voices in his head, our hero wonders how he's
1374 supposed to kill the mall. */
1375 void nf_conntrack_cleanup(struct net *net)
1377 if (net_eq(net, &init_net))
1378 RCU_INIT_POINTER(ip_ct_attach, NULL);
1380 /* This makes sure all current packets have passed through
1381 netfilter framework. Roll on, two-stage module
1384 nf_conntrack_proto_fini(net);
1385 nf_conntrack_cleanup_net(net);
1387 if (net_eq(net, &init_net)) {
1388 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1389 nf_conntrack_cleanup_init_net();
1393 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1395 struct hlist_nulls_head *hash;
1396 unsigned int nr_slots, i;
1399 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1400 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1401 sz = nr_slots * sizeof(struct hlist_nulls_head);
1402 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1405 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1410 for (i = 0; i < nr_slots; i++)
1411 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1415 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1417 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1420 unsigned int hashsize, old_size;
1421 struct hlist_nulls_head *hash, *old_hash;
1422 struct nf_conntrack_tuple_hash *h;
1425 if (current->nsproxy->net_ns != &init_net)
1428 /* On boot, we can set this without any fancy locking. */
1429 if (!nf_conntrack_htable_size)
1430 return param_set_uint(val, kp);
1432 hashsize = simple_strtoul(val, NULL, 0);
1436 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1440 /* Lookups in the old hash might happen in parallel, which means we
1441 * might get false negatives during connection lookup. New connections
1442 * created because of a false negative won't make it into the hash
1443 * though since that required taking the lock.
1445 spin_lock_bh(&nf_conntrack_lock);
1446 for (i = 0; i < init_net.ct.htable_size; i++) {
1447 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1448 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1449 struct nf_conntrack_tuple_hash, hnnode);
1450 ct = nf_ct_tuplehash_to_ctrack(h);
1451 hlist_nulls_del_rcu(&h->hnnode);
1452 bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1454 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1457 old_size = init_net.ct.htable_size;
1458 old_hash = init_net.ct.hash;
1460 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1461 init_net.ct.hash = hash;
1462 spin_unlock_bh(&nf_conntrack_lock);
1464 nf_ct_free_hashtable(old_hash, old_size);
1467 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1469 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1470 &nf_conntrack_htable_size, 0600);
1472 void nf_ct_untracked_status_or(unsigned long bits)
1476 for_each_possible_cpu(cpu)
1477 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1479 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1481 static int nf_conntrack_init_init_net(void)
1486 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1487 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1488 if (!nf_conntrack_htable_size) {
1489 nf_conntrack_htable_size
1490 = (((totalram_pages << PAGE_SHIFT) / 16384)
1491 / sizeof(struct hlist_head));
1492 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1493 nf_conntrack_htable_size = 16384;
1494 if (nf_conntrack_htable_size < 32)
1495 nf_conntrack_htable_size = 32;
1497 /* Use a max. factor of four by default to get the same max as
1498 * with the old struct list_heads. When a table size is given
1499 * we use the old value of 8 to avoid reducing the max.
1503 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1505 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1506 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1508 #ifdef CONFIG_NF_CONNTRACK_ZONES
1509 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1513 /* Set up fake conntrack: to never be deleted, not in any hashes */
1514 for_each_possible_cpu(cpu) {
1515 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1516 write_pnet(&ct->ct_net, &init_net);
1517 atomic_set(&ct->ct_general.use, 1);
1519 /* - and look it like as a confirmed connection */
1520 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1523 #ifdef CONFIG_NF_CONNTRACK_ZONES
1530 * We need to use special "null" values, not used in hash table
1532 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1533 #define DYING_NULLS_VAL ((1<<30)+1)
1535 static int nf_conntrack_init_net(struct net *net)
1539 atomic_set(&net->ct.count, 0);
1540 INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
1541 INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
1542 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1543 if (!net->ct.stat) {
1548 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1549 if (!net->ct.slabname) {
1554 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1555 sizeof(struct nf_conn), 0,
1556 SLAB_DESTROY_BY_RCU, NULL);
1557 if (!net->ct.nf_conntrack_cachep) {
1558 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1563 net->ct.htable_size = nf_conntrack_htable_size;
1564 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1565 if (!net->ct.hash) {
1567 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1570 ret = nf_conntrack_expect_init(net);
1573 ret = nf_conntrack_acct_init(net);
1576 ret = nf_conntrack_tstamp_init(net);
1579 ret = nf_conntrack_ecache_init(net);
1582 ret = nf_conntrack_timeout_init(net);
1585 ret = nf_conntrack_helper_init(net);
1590 nf_conntrack_timeout_fini(net);
1592 nf_conntrack_ecache_fini(net);
1594 nf_conntrack_tstamp_fini(net);
1596 nf_conntrack_acct_fini(net);
1598 nf_conntrack_expect_fini(net);
1600 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1602 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1604 kfree(net->ct.slabname);
1606 free_percpu(net->ct.stat);
1611 s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
1612 enum ip_conntrack_dir dir,
1614 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
1616 int nf_conntrack_init(struct net *net)
1620 if (net_eq(net, &init_net)) {
1621 ret = nf_conntrack_init_init_net();
1625 ret = nf_conntrack_proto_init(net);
1628 ret = nf_conntrack_init_net(net);
1632 if (net_eq(net, &init_net)) {
1633 /* For use by REJECT target */
1634 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1635 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1637 /* Howto get NAT offsets */
1638 RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
1643 nf_conntrack_proto_fini(net);
1645 if (net_eq(net, &init_net))
1646 nf_conntrack_cleanup_init_net();