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 or dying list.*/
225 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
226 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
228 NF_CT_STAT_INC(net, delete);
229 spin_unlock_bh(&nf_conntrack_lock);
232 nf_ct_put(ct->master);
234 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
235 nf_conntrack_free(ct);
238 void nf_ct_delete_from_lists(struct nf_conn *ct)
240 struct net *net = nf_ct_net(ct);
242 nf_ct_helper_destroy(ct);
243 spin_lock_bh(&nf_conntrack_lock);
244 /* Inside lock so preempt is disabled on module removal path.
245 * Otherwise we can get spurious warnings. */
246 NF_CT_STAT_INC(net, delete_list);
247 clean_from_lists(ct);
248 /* add this conntrack to the dying list */
249 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
251 spin_unlock_bh(&nf_conntrack_lock);
253 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
255 static void death_by_event(unsigned long ul_conntrack)
257 struct nf_conn *ct = (void *)ul_conntrack;
258 struct net *net = nf_ct_net(ct);
259 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
261 BUG_ON(ecache == NULL);
263 if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
264 /* bad luck, let's retry again */
265 ecache->timeout.expires = jiffies +
266 (random32() % net->ct.sysctl_events_retry_timeout);
267 add_timer(&ecache->timeout);
270 /* we've got the event delivered, now it's dying */
271 set_bit(IPS_DYING_BIT, &ct->status);
275 void nf_ct_dying_timeout(struct nf_conn *ct)
277 struct net *net = nf_ct_net(ct);
278 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
280 BUG_ON(ecache == NULL);
282 /* set a new timer to retry event delivery */
283 setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
284 ecache->timeout.expires = jiffies +
285 (random32() % net->ct.sysctl_events_retry_timeout);
286 add_timer(&ecache->timeout);
288 EXPORT_SYMBOL_GPL(nf_ct_dying_timeout);
290 static void death_by_timeout(unsigned long ul_conntrack)
292 struct nf_conn *ct = (void *)ul_conntrack;
293 struct nf_conn_tstamp *tstamp;
295 tstamp = nf_conn_tstamp_find(ct);
296 if (tstamp && tstamp->stop == 0)
297 tstamp->stop = ktime_to_ns(ktime_get_real());
299 if (!test_bit(IPS_DYING_BIT, &ct->status) &&
300 unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
301 /* destroy event was not delivered */
302 nf_ct_delete_from_lists(ct);
303 nf_ct_dying_timeout(ct);
306 set_bit(IPS_DYING_BIT, &ct->status);
307 nf_ct_delete_from_lists(ct);
313 * - Caller must take a reference on returned object
314 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
316 * - Caller must lock nf_conntrack_lock before calling this function
318 static struct nf_conntrack_tuple_hash *
319 ____nf_conntrack_find(struct net *net, u16 zone,
320 const struct nf_conntrack_tuple *tuple, u32 hash)
322 struct nf_conntrack_tuple_hash *h;
323 struct hlist_nulls_node *n;
324 unsigned int bucket = hash_bucket(hash, net);
326 /* Disable BHs the entire time since we normally need to disable them
327 * at least once for the stats anyway.
331 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
332 if (nf_ct_tuple_equal(tuple, &h->tuple) &&
333 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
334 NF_CT_STAT_INC(net, found);
338 NF_CT_STAT_INC(net, searched);
341 * if the nulls value we got at the end of this lookup is
342 * not the expected one, we must restart lookup.
343 * We probably met an item that was moved to another chain.
345 if (get_nulls_value(n) != bucket) {
346 NF_CT_STAT_INC(net, search_restart);
354 struct nf_conntrack_tuple_hash *
355 __nf_conntrack_find(struct net *net, u16 zone,
356 const struct nf_conntrack_tuple *tuple)
358 return ____nf_conntrack_find(net, zone, tuple,
359 hash_conntrack_raw(tuple, zone));
361 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
363 /* Find a connection corresponding to a tuple. */
364 static struct nf_conntrack_tuple_hash *
365 __nf_conntrack_find_get(struct net *net, u16 zone,
366 const struct nf_conntrack_tuple *tuple, u32 hash)
368 struct nf_conntrack_tuple_hash *h;
373 h = ____nf_conntrack_find(net, zone, tuple, hash);
375 ct = nf_ct_tuplehash_to_ctrack(h);
376 if (unlikely(nf_ct_is_dying(ct) ||
377 !atomic_inc_not_zero(&ct->ct_general.use)))
380 if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
381 nf_ct_zone(ct) != zone)) {
392 struct nf_conntrack_tuple_hash *
393 nf_conntrack_find_get(struct net *net, u16 zone,
394 const struct nf_conntrack_tuple *tuple)
396 return __nf_conntrack_find_get(net, zone, tuple,
397 hash_conntrack_raw(tuple, zone));
399 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
401 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
403 unsigned int repl_hash)
405 struct net *net = nf_ct_net(ct);
407 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
408 &net->ct.hash[hash]);
409 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
410 &net->ct.hash[repl_hash]);
414 nf_conntrack_hash_check_insert(struct nf_conn *ct)
416 struct net *net = nf_ct_net(ct);
417 unsigned int hash, repl_hash;
418 struct nf_conntrack_tuple_hash *h;
419 struct hlist_nulls_node *n;
422 zone = nf_ct_zone(ct);
423 hash = hash_conntrack(net, zone,
424 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
425 repl_hash = hash_conntrack(net, zone,
426 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
428 spin_lock_bh(&nf_conntrack_lock);
430 /* See if there's one in the list already, including reverse */
431 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
432 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
434 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
436 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
437 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
439 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
442 add_timer(&ct->timeout);
443 nf_conntrack_get(&ct->ct_general);
444 __nf_conntrack_hash_insert(ct, hash, repl_hash);
445 NF_CT_STAT_INC(net, insert);
446 spin_unlock_bh(&nf_conntrack_lock);
451 NF_CT_STAT_INC(net, insert_failed);
452 spin_unlock_bh(&nf_conntrack_lock);
455 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
457 /* Confirm a connection given skb; places it in hash table */
459 __nf_conntrack_confirm(struct sk_buff *skb)
461 unsigned int hash, repl_hash;
462 struct nf_conntrack_tuple_hash *h;
464 struct nf_conn_help *help;
465 struct nf_conn_tstamp *tstamp;
466 struct hlist_nulls_node *n;
467 enum ip_conntrack_info ctinfo;
471 ct = nf_ct_get(skb, &ctinfo);
474 /* ipt_REJECT uses nf_conntrack_attach to attach related
475 ICMP/TCP RST packets in other direction. Actual packet
476 which created connection will be IP_CT_NEW or for an
477 expected connection, IP_CT_RELATED. */
478 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
481 zone = nf_ct_zone(ct);
482 /* reuse the hash saved before */
483 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
484 hash = hash_bucket(hash, net);
485 repl_hash = hash_conntrack(net, zone,
486 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
488 /* We're not in hash table, and we refuse to set up related
489 connections for unconfirmed conns. But packet copies and
490 REJECT will give spurious warnings here. */
491 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
493 /* No external references means no one else could have
495 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
496 pr_debug("Confirming conntrack %p\n", ct);
498 spin_lock_bh(&nf_conntrack_lock);
500 /* We have to check the DYING flag inside the lock to prevent
501 a race against nf_ct_get_next_corpse() possibly called from
502 user context, else we insert an already 'dead' hash, blocking
503 further use of that particular connection -JM */
505 if (unlikely(nf_ct_is_dying(ct))) {
506 spin_unlock_bh(&nf_conntrack_lock);
510 /* See if there's one in the list already, including reverse:
511 NAT could have grabbed it without realizing, since we're
512 not in the hash. If there is, we lost race. */
513 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
514 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
516 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
518 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
519 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
521 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
524 /* Remove from unconfirmed list */
525 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
527 /* Timer relative to confirmation time, not original
528 setting time, otherwise we'd get timer wrap in
529 weird delay cases. */
530 ct->timeout.expires += jiffies;
531 add_timer(&ct->timeout);
532 atomic_inc(&ct->ct_general.use);
533 ct->status |= IPS_CONFIRMED;
535 /* set conntrack timestamp, if enabled. */
536 tstamp = nf_conn_tstamp_find(ct);
538 if (skb->tstamp.tv64 == 0)
539 __net_timestamp(skb);
541 tstamp->start = ktime_to_ns(skb->tstamp);
543 /* Since the lookup is lockless, hash insertion must be done after
544 * starting the timer and setting the CONFIRMED bit. The RCU barriers
545 * guarantee that no other CPU can find the conntrack before the above
546 * stores are visible.
548 __nf_conntrack_hash_insert(ct, hash, repl_hash);
549 NF_CT_STAT_INC(net, insert);
550 spin_unlock_bh(&nf_conntrack_lock);
552 help = nfct_help(ct);
553 if (help && help->helper)
554 nf_conntrack_event_cache(IPCT_HELPER, ct);
556 nf_conntrack_event_cache(master_ct(ct) ?
557 IPCT_RELATED : IPCT_NEW, ct);
561 NF_CT_STAT_INC(net, insert_failed);
562 spin_unlock_bh(&nf_conntrack_lock);
565 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
567 /* Returns true if a connection correspondings to the tuple (required
570 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
571 const struct nf_conn *ignored_conntrack)
573 struct net *net = nf_ct_net(ignored_conntrack);
574 struct nf_conntrack_tuple_hash *h;
575 struct hlist_nulls_node *n;
577 u16 zone = nf_ct_zone(ignored_conntrack);
578 unsigned int hash = hash_conntrack(net, zone, tuple);
580 /* Disable BHs the entire time since we need to disable them at
581 * least once for the stats anyway.
584 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
585 ct = nf_ct_tuplehash_to_ctrack(h);
586 if (ct != ignored_conntrack &&
587 nf_ct_tuple_equal(tuple, &h->tuple) &&
588 nf_ct_zone(ct) == zone) {
589 NF_CT_STAT_INC(net, found);
590 rcu_read_unlock_bh();
593 NF_CT_STAT_INC(net, searched);
595 rcu_read_unlock_bh();
599 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
601 #define NF_CT_EVICTION_RANGE 8
603 /* There's a small race here where we may free a just-assured
604 connection. Too bad: we're in trouble anyway. */
605 static noinline int early_drop(struct net *net, unsigned int hash)
607 /* Use oldest entry, which is roughly LRU */
608 struct nf_conntrack_tuple_hash *h;
609 struct nf_conn *ct = NULL, *tmp;
610 struct hlist_nulls_node *n;
611 unsigned int i, cnt = 0;
615 for (i = 0; i < net->ct.htable_size; i++) {
616 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
618 tmp = nf_ct_tuplehash_to_ctrack(h);
619 if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
625 if (likely(!nf_ct_is_dying(ct) &&
626 atomic_inc_not_zero(&ct->ct_general.use)))
632 if (cnt >= NF_CT_EVICTION_RANGE)
635 hash = (hash + 1) % net->ct.htable_size;
642 if (del_timer(&ct->timeout)) {
643 death_by_timeout((unsigned long)ct);
644 /* Check if we indeed killed this entry. Reliable event
645 delivery may have inserted it into the dying list. */
646 if (test_bit(IPS_DYING_BIT, &ct->status)) {
648 NF_CT_STAT_INC_ATOMIC(net, early_drop);
655 void init_nf_conntrack_hash_rnd(void)
660 * Why not initialize nf_conntrack_rnd in a "init()" function ?
661 * Because there isn't enough entropy when system initializing,
662 * and we initialize it as late as possible.
665 get_random_bytes(&rand, sizeof(rand));
667 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
670 static struct nf_conn *
671 __nf_conntrack_alloc(struct net *net, u16 zone,
672 const struct nf_conntrack_tuple *orig,
673 const struct nf_conntrack_tuple *repl,
678 if (unlikely(!nf_conntrack_hash_rnd)) {
679 init_nf_conntrack_hash_rnd();
680 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
681 hash = hash_conntrack_raw(orig, zone);
684 /* We don't want any race condition at early drop stage */
685 atomic_inc(&net->ct.count);
687 if (nf_conntrack_max &&
688 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
689 if (!early_drop(net, hash_bucket(hash, net))) {
690 atomic_dec(&net->ct.count);
691 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
692 return ERR_PTR(-ENOMEM);
697 * Do not use kmem_cache_zalloc(), as this cache uses
698 * SLAB_DESTROY_BY_RCU.
700 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
702 atomic_dec(&net->ct.count);
703 return ERR_PTR(-ENOMEM);
706 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
707 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
709 memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
710 offsetof(struct nf_conn, proto) -
711 offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
712 spin_lock_init(&ct->lock);
713 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
714 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
715 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
716 /* save hash for reusing when confirming */
717 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
718 /* Don't set timer yet: wait for confirmation */
719 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
720 write_pnet(&ct->ct_net, net);
721 #ifdef CONFIG_NF_CONNTRACK_ZONES
723 struct nf_conntrack_zone *nf_ct_zone;
725 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
728 nf_ct_zone->id = zone;
732 * changes to lookup keys must be done before setting refcnt to 1
735 atomic_set(&ct->ct_general.use, 1);
738 #ifdef CONFIG_NF_CONNTRACK_ZONES
740 atomic_dec(&net->ct.count);
741 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
742 return ERR_PTR(-ENOMEM);
746 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
747 const struct nf_conntrack_tuple *orig,
748 const struct nf_conntrack_tuple *repl,
751 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
753 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
755 void nf_conntrack_free(struct nf_conn *ct)
757 struct net *net = nf_ct_net(ct);
759 nf_ct_ext_destroy(ct);
760 atomic_dec(&net->ct.count);
762 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
764 EXPORT_SYMBOL_GPL(nf_conntrack_free);
766 /* Allocate a new conntrack: we return -ENOMEM if classification
767 failed due to stress. Otherwise it really is unclassifiable. */
768 static struct nf_conntrack_tuple_hash *
769 init_conntrack(struct net *net, struct nf_conn *tmpl,
770 const struct nf_conntrack_tuple *tuple,
771 struct nf_conntrack_l3proto *l3proto,
772 struct nf_conntrack_l4proto *l4proto,
774 unsigned int dataoff, u32 hash)
777 struct nf_conn_help *help;
778 struct nf_conntrack_tuple repl_tuple;
779 struct nf_conntrack_ecache *ecache;
780 struct nf_conntrack_expect *exp;
781 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
782 struct nf_conn_timeout *timeout_ext;
783 unsigned int *timeouts;
785 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
786 pr_debug("Can't invert tuple.\n");
790 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
793 return (struct nf_conntrack_tuple_hash *)ct;
795 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
797 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
799 timeouts = l4proto->get_timeouts(net);
801 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
802 nf_conntrack_free(ct);
803 pr_debug("init conntrack: can't track with proto module\n");
808 nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);
810 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
811 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
813 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
814 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
815 ecache ? ecache->expmask : 0,
818 spin_lock_bh(&nf_conntrack_lock);
819 exp = nf_ct_find_expectation(net, zone, tuple);
821 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
823 /* Welcome, Mr. Bond. We've been expecting you... */
824 __set_bit(IPS_EXPECTED_BIT, &ct->status);
825 ct->master = exp->master;
827 help = nf_ct_helper_ext_add(ct, exp->helper,
830 rcu_assign_pointer(help->helper, exp->helper);
833 #ifdef CONFIG_NF_CONNTRACK_MARK
834 ct->mark = exp->master->mark;
836 #ifdef CONFIG_NF_CONNTRACK_SECMARK
837 ct->secmark = exp->master->secmark;
839 nf_conntrack_get(&ct->master->ct_general);
840 NF_CT_STAT_INC(net, expect_new);
842 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
843 NF_CT_STAT_INC(net, new);
846 /* Overload tuple linked list to put us in unconfirmed list. */
847 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
848 &net->ct.unconfirmed);
850 spin_unlock_bh(&nf_conntrack_lock);
854 exp->expectfn(ct, exp);
855 nf_ct_expect_put(exp);
858 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
861 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
862 static inline struct nf_conn *
863 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
865 unsigned int dataoff,
868 struct nf_conntrack_l3proto *l3proto,
869 struct nf_conntrack_l4proto *l4proto,
871 enum ip_conntrack_info *ctinfo)
873 struct nf_conntrack_tuple tuple;
874 struct nf_conntrack_tuple_hash *h;
876 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
879 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
880 dataoff, l3num, protonum, &tuple, l3proto,
882 pr_debug("resolve_normal_ct: Can't get tuple\n");
886 /* look for tuple match */
887 hash = hash_conntrack_raw(&tuple, zone);
888 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
890 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
897 ct = nf_ct_tuplehash_to_ctrack(h);
899 /* It exists; we have (non-exclusive) reference. */
900 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
901 *ctinfo = IP_CT_ESTABLISHED_REPLY;
902 /* Please set reply bit if this packet OK */
905 /* Once we've had two way comms, always ESTABLISHED. */
906 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
907 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
908 *ctinfo = IP_CT_ESTABLISHED;
909 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
910 pr_debug("nf_conntrack_in: related packet for %p\n",
912 *ctinfo = IP_CT_RELATED;
914 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
919 skb->nfct = &ct->ct_general;
920 skb->nfctinfo = *ctinfo;
925 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
928 struct nf_conn *ct, *tmpl = NULL;
929 enum ip_conntrack_info ctinfo;
930 struct nf_conntrack_l3proto *l3proto;
931 struct nf_conntrack_l4proto *l4proto;
932 unsigned int *timeouts;
933 unsigned int dataoff;
939 /* Previously seen (loopback or untracked)? Ignore. */
940 tmpl = (struct nf_conn *)skb->nfct;
941 if (!nf_ct_is_template(tmpl)) {
942 NF_CT_STAT_INC_ATOMIC(net, ignore);
948 /* rcu_read_lock()ed by nf_hook_slow */
949 l3proto = __nf_ct_l3proto_find(pf);
950 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
951 &dataoff, &protonum);
953 pr_debug("not prepared to track yet or error occurred\n");
954 NF_CT_STAT_INC_ATOMIC(net, error);
955 NF_CT_STAT_INC_ATOMIC(net, invalid);
960 l4proto = __nf_ct_l4proto_find(pf, protonum);
962 /* It may be an special packet, error, unclean...
963 * inverse of the return code tells to the netfilter
964 * core what to do with the packet. */
965 if (l4proto->error != NULL) {
966 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
969 NF_CT_STAT_INC_ATOMIC(net, error);
970 NF_CT_STAT_INC_ATOMIC(net, invalid);
974 /* ICMP[v6] protocol trackers may assign one conntrack. */
979 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
980 l3proto, l4proto, &set_reply, &ctinfo);
982 /* Not valid part of a connection */
983 NF_CT_STAT_INC_ATOMIC(net, invalid);
989 /* Too stressed to deal. */
990 NF_CT_STAT_INC_ATOMIC(net, drop);
995 NF_CT_ASSERT(skb->nfct);
997 /* Decide what timeout policy we want to apply to this flow. */
998 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1000 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1002 /* Invalid: inverse of the return code tells
1003 * the netfilter core what to do */
1004 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1005 nf_conntrack_put(skb->nfct);
1007 NF_CT_STAT_INC_ATOMIC(net, invalid);
1008 if (ret == -NF_DROP)
1009 NF_CT_STAT_INC_ATOMIC(net, drop);
1014 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1015 nf_conntrack_event_cache(IPCT_REPLY, ct);
1018 /* Special case: we have to repeat this hook, assign the
1019 * template again to this packet. We assume that this packet
1020 * has no conntrack assigned. This is used by nf_ct_tcp. */
1021 if (ret == NF_REPEAT)
1022 skb->nfct = (struct nf_conntrack *)tmpl;
1029 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1031 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1032 const struct nf_conntrack_tuple *orig)
1037 ret = nf_ct_invert_tuple(inverse, orig,
1038 __nf_ct_l3proto_find(orig->src.l3num),
1039 __nf_ct_l4proto_find(orig->src.l3num,
1040 orig->dst.protonum));
1044 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1046 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1047 implicitly racy: see __nf_conntrack_confirm */
1048 void nf_conntrack_alter_reply(struct nf_conn *ct,
1049 const struct nf_conntrack_tuple *newreply)
1051 struct nf_conn_help *help = nfct_help(ct);
1053 /* Should be unconfirmed, so not in hash table yet */
1054 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1056 pr_debug("Altering reply tuple of %p to ", ct);
1057 nf_ct_dump_tuple(newreply);
1059 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1060 if (ct->master || (help && !hlist_empty(&help->expectations)))
1064 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1067 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1069 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1070 void __nf_ct_refresh_acct(struct nf_conn *ct,
1071 enum ip_conntrack_info ctinfo,
1072 const struct sk_buff *skb,
1073 unsigned long extra_jiffies,
1076 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1079 /* Only update if this is not a fixed timeout */
1080 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1083 /* If not in hash table, timer will not be active yet */
1084 if (!nf_ct_is_confirmed(ct)) {
1085 ct->timeout.expires = extra_jiffies;
1087 unsigned long newtime = jiffies + extra_jiffies;
1089 /* Only update the timeout if the new timeout is at least
1090 HZ jiffies from the old timeout. Need del_timer for race
1091 avoidance (may already be dying). */
1092 if (newtime - ct->timeout.expires >= HZ)
1093 mod_timer_pending(&ct->timeout, newtime);
1098 struct nf_conn_counter *acct;
1100 acct = nf_conn_acct_find(ct);
1102 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1103 atomic64_add(skb->len, &acct[CTINFO2DIR(ctinfo)].bytes);
1107 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1109 bool __nf_ct_kill_acct(struct nf_conn *ct,
1110 enum ip_conntrack_info ctinfo,
1111 const struct sk_buff *skb,
1115 struct nf_conn_counter *acct;
1117 acct = nf_conn_acct_find(ct);
1119 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1120 atomic64_add(skb->len - skb_network_offset(skb),
1121 &acct[CTINFO2DIR(ctinfo)].bytes);
1125 if (del_timer(&ct->timeout)) {
1126 ct->timeout.function((unsigned long)ct);
1131 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1133 #ifdef CONFIG_NF_CONNTRACK_ZONES
1134 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1135 .len = sizeof(struct nf_conntrack_zone),
1136 .align = __alignof__(struct nf_conntrack_zone),
1137 .id = NF_CT_EXT_ZONE,
1141 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1143 #include <linux/netfilter/nfnetlink.h>
1144 #include <linux/netfilter/nfnetlink_conntrack.h>
1145 #include <linux/mutex.h>
1147 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1148 * in ip_conntrack_core, since we don't want the protocols to autoload
1149 * or depend on ctnetlink */
1150 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1151 const struct nf_conntrack_tuple *tuple)
1153 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1154 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1155 goto nla_put_failure;
1161 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1163 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1164 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1165 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1167 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1169 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1170 struct nf_conntrack_tuple *t)
1172 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1175 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1176 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1180 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1182 int nf_ct_port_nlattr_tuple_size(void)
1184 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1186 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1189 /* Used by ipt_REJECT and ip6t_REJECT. */
1190 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1193 enum ip_conntrack_info ctinfo;
1195 /* This ICMP is in reverse direction to the packet which caused it */
1196 ct = nf_ct_get(skb, &ctinfo);
1197 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1198 ctinfo = IP_CT_RELATED_REPLY;
1200 ctinfo = IP_CT_RELATED;
1202 /* Attach to new skbuff, and increment count */
1203 nskb->nfct = &ct->ct_general;
1204 nskb->nfctinfo = ctinfo;
1205 nf_conntrack_get(nskb->nfct);
1208 /* Bring out ya dead! */
1209 static struct nf_conn *
1210 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1211 void *data, unsigned int *bucket)
1213 struct nf_conntrack_tuple_hash *h;
1215 struct hlist_nulls_node *n;
1217 spin_lock_bh(&nf_conntrack_lock);
1218 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1219 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1220 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1222 ct = nf_ct_tuplehash_to_ctrack(h);
1227 hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
1228 ct = nf_ct_tuplehash_to_ctrack(h);
1230 set_bit(IPS_DYING_BIT, &ct->status);
1232 spin_unlock_bh(&nf_conntrack_lock);
1235 atomic_inc(&ct->ct_general.use);
1236 spin_unlock_bh(&nf_conntrack_lock);
1240 void nf_ct_iterate_cleanup(struct net *net,
1241 int (*iter)(struct nf_conn *i, void *data),
1245 unsigned int bucket = 0;
1247 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1248 /* Time to push up daises... */
1249 if (del_timer(&ct->timeout))
1250 death_by_timeout((unsigned long)ct);
1251 /* ... else the timer will get him soon. */
1256 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1258 struct __nf_ct_flush_report {
1263 static int kill_report(struct nf_conn *i, void *data)
1265 struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1266 struct nf_conn_tstamp *tstamp;
1268 tstamp = nf_conn_tstamp_find(i);
1269 if (tstamp && tstamp->stop == 0)
1270 tstamp->stop = ktime_to_ns(ktime_get_real());
1272 /* If we fail to deliver the event, death_by_timeout() will retry */
1273 if (nf_conntrack_event_report(IPCT_DESTROY, i,
1274 fr->pid, fr->report) < 0)
1277 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1278 set_bit(IPS_DYING_BIT, &i->status);
1282 static int kill_all(struct nf_conn *i, void *data)
1287 void nf_ct_free_hashtable(void *hash, unsigned int size)
1289 if (is_vmalloc_addr(hash))
1292 free_pages((unsigned long)hash,
1293 get_order(sizeof(struct hlist_head) * size));
1295 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1297 void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
1299 struct __nf_ct_flush_report fr = {
1303 nf_ct_iterate_cleanup(net, kill_report, &fr);
1305 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1307 static void nf_ct_release_dying_list(struct net *net)
1309 struct nf_conntrack_tuple_hash *h;
1311 struct hlist_nulls_node *n;
1313 spin_lock_bh(&nf_conntrack_lock);
1314 hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
1315 ct = nf_ct_tuplehash_to_ctrack(h);
1316 /* never fails to remove them, no listeners at this point */
1319 spin_unlock_bh(&nf_conntrack_lock);
1322 static int untrack_refs(void)
1326 for_each_possible_cpu(cpu) {
1327 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1329 cnt += atomic_read(&ct->ct_general.use) - 1;
1334 static void nf_conntrack_cleanup_init_net(void)
1336 while (untrack_refs() > 0)
1339 #ifdef CONFIG_NF_CONNTRACK_ZONES
1340 nf_ct_extend_unregister(&nf_ct_zone_extend);
1344 static void nf_conntrack_cleanup_net(struct net *net)
1347 nf_ct_iterate_cleanup(net, kill_all, NULL);
1348 nf_ct_release_dying_list(net);
1349 if (atomic_read(&net->ct.count) != 0) {
1351 goto i_see_dead_people;
1354 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1355 nf_conntrack_helper_fini(net);
1356 nf_conntrack_timeout_fini(net);
1357 nf_conntrack_ecache_fini(net);
1358 nf_conntrack_tstamp_fini(net);
1359 nf_conntrack_acct_fini(net);
1360 nf_conntrack_expect_fini(net);
1361 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1362 kfree(net->ct.slabname);
1363 free_percpu(net->ct.stat);
1366 /* Mishearing the voices in his head, our hero wonders how he's
1367 supposed to kill the mall. */
1368 void nf_conntrack_cleanup(struct net *net)
1370 if (net_eq(net, &init_net))
1371 RCU_INIT_POINTER(ip_ct_attach, NULL);
1373 /* This makes sure all current packets have passed through
1374 netfilter framework. Roll on, two-stage module
1377 nf_conntrack_proto_fini(net);
1378 nf_conntrack_cleanup_net(net);
1380 if (net_eq(net, &init_net)) {
1381 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1382 nf_conntrack_cleanup_init_net();
1386 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1388 struct hlist_nulls_head *hash;
1389 unsigned int nr_slots, i;
1392 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1393 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1394 sz = nr_slots * sizeof(struct hlist_nulls_head);
1395 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1398 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1403 for (i = 0; i < nr_slots; i++)
1404 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1408 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1410 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1413 unsigned int hashsize, old_size;
1414 struct hlist_nulls_head *hash, *old_hash;
1415 struct nf_conntrack_tuple_hash *h;
1418 if (current->nsproxy->net_ns != &init_net)
1421 /* On boot, we can set this without any fancy locking. */
1422 if (!nf_conntrack_htable_size)
1423 return param_set_uint(val, kp);
1425 rc = kstrtouint(val, 0, &hashsize);
1431 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1435 /* Lookups in the old hash might happen in parallel, which means we
1436 * might get false negatives during connection lookup. New connections
1437 * created because of a false negative won't make it into the hash
1438 * though since that required taking the lock.
1440 spin_lock_bh(&nf_conntrack_lock);
1441 for (i = 0; i < init_net.ct.htable_size; i++) {
1442 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1443 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1444 struct nf_conntrack_tuple_hash, hnnode);
1445 ct = nf_ct_tuplehash_to_ctrack(h);
1446 hlist_nulls_del_rcu(&h->hnnode);
1447 bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1449 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1452 old_size = init_net.ct.htable_size;
1453 old_hash = init_net.ct.hash;
1455 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1456 init_net.ct.hash = hash;
1457 spin_unlock_bh(&nf_conntrack_lock);
1459 nf_ct_free_hashtable(old_hash, old_size);
1462 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1464 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1465 &nf_conntrack_htable_size, 0600);
1467 void nf_ct_untracked_status_or(unsigned long bits)
1471 for_each_possible_cpu(cpu)
1472 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1474 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1476 static int nf_conntrack_init_init_net(void)
1481 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1482 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1483 if (!nf_conntrack_htable_size) {
1484 nf_conntrack_htable_size
1485 = (((totalram_pages << PAGE_SHIFT) / 16384)
1486 / sizeof(struct hlist_head));
1487 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1488 nf_conntrack_htable_size = 16384;
1489 if (nf_conntrack_htable_size < 32)
1490 nf_conntrack_htable_size = 32;
1492 /* Use a max. factor of four by default to get the same max as
1493 * with the old struct list_heads. When a table size is given
1494 * we use the old value of 8 to avoid reducing the max.
1498 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1500 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1501 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1503 #ifdef CONFIG_NF_CONNTRACK_ZONES
1504 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1508 /* Set up fake conntrack: to never be deleted, not in any hashes */
1509 for_each_possible_cpu(cpu) {
1510 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1511 write_pnet(&ct->ct_net, &init_net);
1512 atomic_set(&ct->ct_general.use, 1);
1514 /* - and look it like as a confirmed connection */
1515 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1518 #ifdef CONFIG_NF_CONNTRACK_ZONES
1525 * We need to use special "null" values, not used in hash table
1527 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1528 #define DYING_NULLS_VAL ((1<<30)+1)
1530 static int nf_conntrack_init_net(struct net *net)
1534 atomic_set(&net->ct.count, 0);
1535 INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
1536 INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
1537 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1538 if (!net->ct.stat) {
1543 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1544 if (!net->ct.slabname) {
1549 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1550 sizeof(struct nf_conn), 0,
1551 SLAB_DESTROY_BY_RCU, NULL);
1552 if (!net->ct.nf_conntrack_cachep) {
1553 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1558 net->ct.htable_size = nf_conntrack_htable_size;
1559 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1560 if (!net->ct.hash) {
1562 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1565 ret = nf_conntrack_expect_init(net);
1568 ret = nf_conntrack_acct_init(net);
1571 ret = nf_conntrack_tstamp_init(net);
1574 ret = nf_conntrack_ecache_init(net);
1577 ret = nf_conntrack_timeout_init(net);
1580 ret = nf_conntrack_helper_init(net);
1585 nf_conntrack_timeout_fini(net);
1587 nf_conntrack_ecache_fini(net);
1589 nf_conntrack_tstamp_fini(net);
1591 nf_conntrack_acct_fini(net);
1593 nf_conntrack_expect_fini(net);
1595 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1597 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1599 kfree(net->ct.slabname);
1601 free_percpu(net->ct.stat);
1606 s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
1607 enum ip_conntrack_dir dir,
1609 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
1611 int nf_conntrack_init(struct net *net)
1615 if (net_eq(net, &init_net)) {
1616 ret = nf_conntrack_init_init_net();
1620 ret = nf_conntrack_proto_init(net);
1623 ret = nf_conntrack_init_net(net);
1627 if (net_eq(net, &init_net)) {
1628 /* For use by REJECT target */
1629 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1630 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1632 /* Howto get NAT offsets */
1633 RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
1638 nf_conntrack_proto_fini(net);
1640 if (net_eq(net, &init_net))
1641 nf_conntrack_cleanup_init_net();