1 /* Connection state tracking for netfilter. This is separated from,
2 but required by, the NAT layer; it can also be used by an iptables
5 /* (C) 1999-2001 Paul `Rusty' Russell
6 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
7 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
8 * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/types.h>
16 #include <linux/netfilter.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/skbuff.h>
20 #include <linux/proc_fs.h>
21 #include <linux/vmalloc.h>
22 #include <linux/stddef.h>
23 #include <linux/slab.h>
24 #include <linux/random.h>
25 #include <linux/jhash.h>
26 #include <linux/err.h>
27 #include <linux/percpu.h>
28 #include <linux/moduleparam.h>
29 #include <linux/notifier.h>
30 #include <linux/kernel.h>
31 #include <linux/netdevice.h>
32 #include <linux/socket.h>
34 #include <linux/nsproxy.h>
35 #include <linux/rculist_nulls.h>
37 #include <net/netfilter/nf_conntrack.h>
38 #include <net/netfilter/nf_conntrack_l3proto.h>
39 #include <net/netfilter/nf_conntrack_l4proto.h>
40 #include <net/netfilter/nf_conntrack_expect.h>
41 #include <net/netfilter/nf_conntrack_helper.h>
42 #include <net/netfilter/nf_conntrack_core.h>
43 #include <net/netfilter/nf_conntrack_extend.h>
44 #include <net/netfilter/nf_conntrack_acct.h>
45 #include <net/netfilter/nf_conntrack_ecache.h>
46 #include <net/netfilter/nf_conntrack_zones.h>
47 #include <net/netfilter/nf_conntrack_timestamp.h>
48 #include <net/netfilter/nf_conntrack_timeout.h>
49 #include <net/netfilter/nf_conntrack_labels.h>
50 #include <net/netfilter/nf_nat.h>
51 #include <net/netfilter/nf_nat_core.h>
52 #include <net/netfilter/nf_nat_helper.h>
54 #define NF_CONNTRACK_VERSION "0.5.0"
56 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
57 enum nf_nat_manip_type manip,
58 const struct nlattr *attr) __read_mostly;
59 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
61 int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
63 enum ip_conntrack_info ctinfo,
64 unsigned int protoff);
65 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
67 DEFINE_SPINLOCK(nf_conntrack_lock);
68 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
70 unsigned int nf_conntrack_htable_size __read_mostly;
71 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
73 unsigned int nf_conntrack_max __read_mostly;
74 EXPORT_SYMBOL_GPL(nf_conntrack_max);
76 DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
77 EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
79 unsigned int nf_conntrack_hash_rnd __read_mostly;
80 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
82 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
86 /* The direction must be ignored, so we hash everything up to the
87 * destination ports (which is a multiple of 4) and treat the last
88 * three bytes manually.
90 n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
91 return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
92 (((__force __u16)tuple->dst.u.all << 16) |
93 tuple->dst.protonum));
96 static u32 __hash_bucket(u32 hash, unsigned int size)
98 return ((u64)hash * size) >> 32;
101 static u32 hash_bucket(u32 hash, const struct net *net)
103 return __hash_bucket(hash, net->ct.htable_size);
106 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
107 u16 zone, unsigned int size)
109 return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
112 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
113 const struct nf_conntrack_tuple *tuple)
115 return __hash_conntrack(tuple, zone, net->ct.htable_size);
119 nf_ct_get_tuple(const struct sk_buff *skb,
121 unsigned int dataoff,
124 struct nf_conntrack_tuple *tuple,
125 const struct nf_conntrack_l3proto *l3proto,
126 const struct nf_conntrack_l4proto *l4proto)
128 memset(tuple, 0, sizeof(*tuple));
130 tuple->src.l3num = l3num;
131 if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
134 tuple->dst.protonum = protonum;
135 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
137 return l4proto->pkt_to_tuple(skb, dataoff, tuple);
139 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
141 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
142 u_int16_t l3num, struct nf_conntrack_tuple *tuple)
144 struct nf_conntrack_l3proto *l3proto;
145 struct nf_conntrack_l4proto *l4proto;
146 unsigned int protoff;
152 l3proto = __nf_ct_l3proto_find(l3num);
153 ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
154 if (ret != NF_ACCEPT) {
159 l4proto = __nf_ct_l4proto_find(l3num, protonum);
161 ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
167 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
170 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
171 const struct nf_conntrack_tuple *orig,
172 const struct nf_conntrack_l3proto *l3proto,
173 const struct nf_conntrack_l4proto *l4proto)
175 memset(inverse, 0, sizeof(*inverse));
177 inverse->src.l3num = orig->src.l3num;
178 if (l3proto->invert_tuple(inverse, orig) == 0)
181 inverse->dst.dir = !orig->dst.dir;
183 inverse->dst.protonum = orig->dst.protonum;
184 return l4proto->invert_tuple(inverse, orig);
186 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
189 clean_from_lists(struct nf_conn *ct)
191 pr_debug("clean_from_lists(%p)\n", ct);
192 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
193 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
195 /* Destroy all pending expectations */
196 nf_ct_remove_expectations(ct);
200 destroy_conntrack(struct nf_conntrack *nfct)
202 struct nf_conn *ct = (struct nf_conn *)nfct;
203 struct net *net = nf_ct_net(ct);
204 struct nf_conntrack_l4proto *l4proto;
206 pr_debug("destroy_conntrack(%p)\n", ct);
207 NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
208 NF_CT_ASSERT(!timer_pending(&ct->timeout));
210 /* To make sure we don't get any weird locking issues here:
211 * destroy_conntrack() MUST NOT be called with a write lock
212 * to nf_conntrack_lock!!! -HW */
214 l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
215 if (l4proto && l4proto->destroy)
216 l4proto->destroy(ct);
220 spin_lock_bh(&nf_conntrack_lock);
221 /* Expectations will have been removed in clean_from_lists,
222 * except TFTP can create an expectation on the first packet,
223 * before connection is in the list, so we need to clean here,
225 nf_ct_remove_expectations(ct);
227 /* We overload first tuple to link into unconfirmed or dying list.*/
228 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
229 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
231 NF_CT_STAT_INC(net, delete);
232 spin_unlock_bh(&nf_conntrack_lock);
235 nf_ct_put(ct->master);
237 pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
238 nf_conntrack_free(ct);
241 void nf_ct_delete_from_lists(struct nf_conn *ct)
243 struct net *net = nf_ct_net(ct);
245 nf_ct_helper_destroy(ct);
246 spin_lock_bh(&nf_conntrack_lock);
247 /* Inside lock so preempt is disabled on module removal path.
248 * Otherwise we can get spurious warnings. */
249 NF_CT_STAT_INC(net, delete_list);
250 clean_from_lists(ct);
251 /* add this conntrack to the dying list */
252 hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
254 spin_unlock_bh(&nf_conntrack_lock);
256 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
258 static void death_by_event(unsigned long ul_conntrack)
260 struct nf_conn *ct = (void *)ul_conntrack;
261 struct net *net = nf_ct_net(ct);
262 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
264 BUG_ON(ecache == NULL);
266 if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
267 /* bad luck, let's retry again */
268 ecache->timeout.expires = jiffies +
269 (prandom_u32() % net->ct.sysctl_events_retry_timeout);
270 add_timer(&ecache->timeout);
273 /* we've got the event delivered, now it's dying */
274 set_bit(IPS_DYING_BIT, &ct->status);
278 void nf_ct_dying_timeout(struct nf_conn *ct)
280 struct net *net = nf_ct_net(ct);
281 struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
283 BUG_ON(ecache == NULL);
285 /* set a new timer to retry event delivery */
286 setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
287 ecache->timeout.expires = jiffies +
288 (prandom_u32() % net->ct.sysctl_events_retry_timeout);
289 add_timer(&ecache->timeout);
291 EXPORT_SYMBOL_GPL(nf_ct_dying_timeout);
293 static void death_by_timeout(unsigned long ul_conntrack)
295 struct nf_conn *ct = (void *)ul_conntrack;
296 struct nf_conn_tstamp *tstamp;
298 tstamp = nf_conn_tstamp_find(ct);
299 if (tstamp && tstamp->stop == 0)
300 tstamp->stop = ktime_to_ns(ktime_get_real());
302 if (!test_bit(IPS_DYING_BIT, &ct->status) &&
303 unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
304 /* destroy event was not delivered */
305 nf_ct_delete_from_lists(ct);
306 nf_ct_dying_timeout(ct);
309 set_bit(IPS_DYING_BIT, &ct->status);
310 nf_ct_delete_from_lists(ct);
316 * - Caller must take a reference on returned object
317 * and recheck nf_ct_tuple_equal(tuple, &h->tuple)
319 * - Caller must lock nf_conntrack_lock before calling this function
321 static struct nf_conntrack_tuple_hash *
322 ____nf_conntrack_find(struct net *net, u16 zone,
323 const struct nf_conntrack_tuple *tuple, u32 hash)
325 struct nf_conntrack_tuple_hash *h;
326 struct hlist_nulls_node *n;
327 unsigned int bucket = hash_bucket(hash, net);
329 /* Disable BHs the entire time since we normally need to disable them
330 * at least once for the stats anyway.
334 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
335 if (nf_ct_tuple_equal(tuple, &h->tuple) &&
336 nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
337 NF_CT_STAT_INC(net, found);
341 NF_CT_STAT_INC(net, searched);
344 * if the nulls value we got at the end of this lookup is
345 * not the expected one, we must restart lookup.
346 * We probably met an item that was moved to another chain.
348 if (get_nulls_value(n) != bucket) {
349 NF_CT_STAT_INC(net, search_restart);
357 struct nf_conntrack_tuple_hash *
358 __nf_conntrack_find(struct net *net, u16 zone,
359 const struct nf_conntrack_tuple *tuple)
361 return ____nf_conntrack_find(net, zone, tuple,
362 hash_conntrack_raw(tuple, zone));
364 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
366 /* Find a connection corresponding to a tuple. */
367 static struct nf_conntrack_tuple_hash *
368 __nf_conntrack_find_get(struct net *net, u16 zone,
369 const struct nf_conntrack_tuple *tuple, u32 hash)
371 struct nf_conntrack_tuple_hash *h;
376 h = ____nf_conntrack_find(net, zone, tuple, hash);
378 ct = nf_ct_tuplehash_to_ctrack(h);
379 if (unlikely(nf_ct_is_dying(ct) ||
380 !atomic_inc_not_zero(&ct->ct_general.use)))
383 if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
384 nf_ct_zone(ct) != zone)) {
395 struct nf_conntrack_tuple_hash *
396 nf_conntrack_find_get(struct net *net, u16 zone,
397 const struct nf_conntrack_tuple *tuple)
399 return __nf_conntrack_find_get(net, zone, tuple,
400 hash_conntrack_raw(tuple, zone));
402 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
404 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
406 unsigned int repl_hash)
408 struct net *net = nf_ct_net(ct);
410 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
411 &net->ct.hash[hash]);
412 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
413 &net->ct.hash[repl_hash]);
417 nf_conntrack_hash_check_insert(struct nf_conn *ct)
419 struct net *net = nf_ct_net(ct);
420 unsigned int hash, repl_hash;
421 struct nf_conntrack_tuple_hash *h;
422 struct hlist_nulls_node *n;
425 zone = nf_ct_zone(ct);
426 hash = hash_conntrack(net, zone,
427 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
428 repl_hash = hash_conntrack(net, zone,
429 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
431 spin_lock_bh(&nf_conntrack_lock);
433 /* See if there's one in the list already, including reverse */
434 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
435 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
437 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
439 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
440 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
442 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
445 add_timer(&ct->timeout);
446 nf_conntrack_get(&ct->ct_general);
447 __nf_conntrack_hash_insert(ct, hash, repl_hash);
448 NF_CT_STAT_INC(net, insert);
449 spin_unlock_bh(&nf_conntrack_lock);
454 NF_CT_STAT_INC(net, insert_failed);
455 spin_unlock_bh(&nf_conntrack_lock);
458 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
460 /* Confirm a connection given skb; places it in hash table */
462 __nf_conntrack_confirm(struct sk_buff *skb)
464 unsigned int hash, repl_hash;
465 struct nf_conntrack_tuple_hash *h;
467 struct nf_conn_help *help;
468 struct nf_conn_tstamp *tstamp;
469 struct hlist_nulls_node *n;
470 enum ip_conntrack_info ctinfo;
474 ct = nf_ct_get(skb, &ctinfo);
477 /* ipt_REJECT uses nf_conntrack_attach to attach related
478 ICMP/TCP RST packets in other direction. Actual packet
479 which created connection will be IP_CT_NEW or for an
480 expected connection, IP_CT_RELATED. */
481 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
484 zone = nf_ct_zone(ct);
485 /* reuse the hash saved before */
486 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
487 hash = hash_bucket(hash, net);
488 repl_hash = hash_conntrack(net, zone,
489 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
491 /* We're not in hash table, and we refuse to set up related
492 connections for unconfirmed conns. But packet copies and
493 REJECT will give spurious warnings here. */
494 /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
496 /* No external references means no one else could have
498 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
499 pr_debug("Confirming conntrack %p\n", ct);
501 spin_lock_bh(&nf_conntrack_lock);
503 /* We have to check the DYING flag inside the lock to prevent
504 a race against nf_ct_get_next_corpse() possibly called from
505 user context, else we insert an already 'dead' hash, blocking
506 further use of that particular connection -JM */
508 if (unlikely(nf_ct_is_dying(ct))) {
509 spin_unlock_bh(&nf_conntrack_lock);
513 /* See if there's one in the list already, including reverse:
514 NAT could have grabbed it without realizing, since we're
515 not in the hash. If there is, we lost race. */
516 hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
517 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
519 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
521 hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
522 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
524 zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
527 /* Remove from unconfirmed list */
528 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
530 /* Timer relative to confirmation time, not original
531 setting time, otherwise we'd get timer wrap in
532 weird delay cases. */
533 ct->timeout.expires += jiffies;
534 add_timer(&ct->timeout);
535 atomic_inc(&ct->ct_general.use);
536 ct->status |= IPS_CONFIRMED;
538 /* set conntrack timestamp, if enabled. */
539 tstamp = nf_conn_tstamp_find(ct);
541 if (skb->tstamp.tv64 == 0)
542 __net_timestamp(skb);
544 tstamp->start = ktime_to_ns(skb->tstamp);
546 /* Since the lookup is lockless, hash insertion must be done after
547 * starting the timer and setting the CONFIRMED bit. The RCU barriers
548 * guarantee that no other CPU can find the conntrack before the above
549 * stores are visible.
551 __nf_conntrack_hash_insert(ct, hash, repl_hash);
552 NF_CT_STAT_INC(net, insert);
553 spin_unlock_bh(&nf_conntrack_lock);
555 help = nfct_help(ct);
556 if (help && help->helper)
557 nf_conntrack_event_cache(IPCT_HELPER, ct);
559 nf_conntrack_event_cache(master_ct(ct) ?
560 IPCT_RELATED : IPCT_NEW, ct);
564 NF_CT_STAT_INC(net, insert_failed);
565 spin_unlock_bh(&nf_conntrack_lock);
568 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
570 /* Returns true if a connection correspondings to the tuple (required
573 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
574 const struct nf_conn *ignored_conntrack)
576 struct net *net = nf_ct_net(ignored_conntrack);
577 struct nf_conntrack_tuple_hash *h;
578 struct hlist_nulls_node *n;
580 u16 zone = nf_ct_zone(ignored_conntrack);
581 unsigned int hash = hash_conntrack(net, zone, tuple);
583 /* Disable BHs the entire time since we need to disable them at
584 * least once for the stats anyway.
587 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
588 ct = nf_ct_tuplehash_to_ctrack(h);
589 if (ct != ignored_conntrack &&
590 nf_ct_tuple_equal(tuple, &h->tuple) &&
591 nf_ct_zone(ct) == zone) {
592 NF_CT_STAT_INC(net, found);
593 rcu_read_unlock_bh();
596 NF_CT_STAT_INC(net, searched);
598 rcu_read_unlock_bh();
602 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
604 #define NF_CT_EVICTION_RANGE 8
606 /* There's a small race here where we may free a just-assured
607 connection. Too bad: we're in trouble anyway. */
608 static noinline int early_drop(struct net *net, unsigned int hash)
610 /* Use oldest entry, which is roughly LRU */
611 struct nf_conntrack_tuple_hash *h;
612 struct nf_conn *ct = NULL, *tmp;
613 struct hlist_nulls_node *n;
614 unsigned int i, cnt = 0;
618 for (i = 0; i < net->ct.htable_size; i++) {
619 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
621 tmp = nf_ct_tuplehash_to_ctrack(h);
622 if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
628 if (likely(!nf_ct_is_dying(ct) &&
629 atomic_inc_not_zero(&ct->ct_general.use)))
635 if (cnt >= NF_CT_EVICTION_RANGE)
638 hash = (hash + 1) % net->ct.htable_size;
645 if (del_timer(&ct->timeout)) {
646 death_by_timeout((unsigned long)ct);
647 /* Check if we indeed killed this entry. Reliable event
648 delivery may have inserted it into the dying list. */
649 if (test_bit(IPS_DYING_BIT, &ct->status)) {
651 NF_CT_STAT_INC_ATOMIC(net, early_drop);
658 void init_nf_conntrack_hash_rnd(void)
663 * Why not initialize nf_conntrack_rnd in a "init()" function ?
664 * Because there isn't enough entropy when system initializing,
665 * and we initialize it as late as possible.
668 get_random_bytes(&rand, sizeof(rand));
670 cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
673 static struct nf_conn *
674 __nf_conntrack_alloc(struct net *net, u16 zone,
675 const struct nf_conntrack_tuple *orig,
676 const struct nf_conntrack_tuple *repl,
681 if (unlikely(!nf_conntrack_hash_rnd)) {
682 init_nf_conntrack_hash_rnd();
683 /* recompute the hash as nf_conntrack_hash_rnd is initialized */
684 hash = hash_conntrack_raw(orig, zone);
687 /* We don't want any race condition at early drop stage */
688 atomic_inc(&net->ct.count);
690 if (nf_conntrack_max &&
691 unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
692 if (!early_drop(net, hash_bucket(hash, net))) {
693 atomic_dec(&net->ct.count);
694 net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
695 return ERR_PTR(-ENOMEM);
700 * Do not use kmem_cache_zalloc(), as this cache uses
701 * SLAB_DESTROY_BY_RCU.
703 ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
705 atomic_dec(&net->ct.count);
706 return ERR_PTR(-ENOMEM);
709 * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
710 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
712 memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
713 offsetof(struct nf_conn, proto) -
714 offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
715 spin_lock_init(&ct->lock);
716 ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
717 ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
718 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
719 /* save hash for reusing when confirming */
720 *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
721 /* Don't set timer yet: wait for confirmation */
722 setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
723 write_pnet(&ct->ct_net, net);
724 #ifdef CONFIG_NF_CONNTRACK_ZONES
726 struct nf_conntrack_zone *nf_ct_zone;
728 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
731 nf_ct_zone->id = zone;
735 * changes to lookup keys must be done before setting refcnt to 1
738 atomic_set(&ct->ct_general.use, 1);
741 #ifdef CONFIG_NF_CONNTRACK_ZONES
743 atomic_dec(&net->ct.count);
744 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
745 return ERR_PTR(-ENOMEM);
749 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
750 const struct nf_conntrack_tuple *orig,
751 const struct nf_conntrack_tuple *repl,
754 return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
756 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
758 void nf_conntrack_free(struct nf_conn *ct)
760 struct net *net = nf_ct_net(ct);
762 nf_ct_ext_destroy(ct);
763 atomic_dec(&net->ct.count);
765 kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
767 EXPORT_SYMBOL_GPL(nf_conntrack_free);
770 /* Allocate a new conntrack: we return -ENOMEM if classification
771 failed due to stress. Otherwise it really is unclassifiable. */
772 static struct nf_conntrack_tuple_hash *
773 init_conntrack(struct net *net, struct nf_conn *tmpl,
774 const struct nf_conntrack_tuple *tuple,
775 struct nf_conntrack_l3proto *l3proto,
776 struct nf_conntrack_l4proto *l4proto,
778 unsigned int dataoff, u32 hash)
781 struct nf_conn_help *help;
782 struct nf_conntrack_tuple repl_tuple;
783 struct nf_conntrack_ecache *ecache;
784 struct nf_conntrack_expect *exp;
785 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
786 struct nf_conn_timeout *timeout_ext;
787 unsigned int *timeouts;
789 if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
790 pr_debug("Can't invert tuple.\n");
794 ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
797 return (struct nf_conntrack_tuple_hash *)ct;
799 timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
801 timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext);
803 timeouts = l4proto->get_timeouts(net);
805 if (!l4proto->new(ct, skb, dataoff, timeouts)) {
806 nf_conntrack_free(ct);
807 pr_debug("init conntrack: can't track with proto module\n");
812 nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);
814 nf_ct_acct_ext_add(ct, GFP_ATOMIC);
815 nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
816 nf_ct_labels_ext_add(ct);
818 ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
819 nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
820 ecache ? ecache->expmask : 0,
823 spin_lock_bh(&nf_conntrack_lock);
824 exp = nf_ct_find_expectation(net, zone, tuple);
826 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
828 /* Welcome, Mr. Bond. We've been expecting you... */
829 __set_bit(IPS_EXPECTED_BIT, &ct->status);
830 ct->master = exp->master;
832 help = nf_ct_helper_ext_add(ct, exp->helper,
835 rcu_assign_pointer(help->helper, exp->helper);
838 #ifdef CONFIG_NF_CONNTRACK_MARK
839 ct->mark = exp->master->mark;
841 #ifdef CONFIG_NF_CONNTRACK_SECMARK
842 ct->secmark = exp->master->secmark;
844 nf_conntrack_get(&ct->master->ct_general);
845 NF_CT_STAT_INC(net, expect_new);
847 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
848 NF_CT_STAT_INC(net, new);
851 /* Overload tuple linked list to put us in unconfirmed list. */
852 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
853 &net->ct.unconfirmed);
855 spin_unlock_bh(&nf_conntrack_lock);
859 exp->expectfn(ct, exp);
860 nf_ct_expect_put(exp);
863 return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
866 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
867 static inline struct nf_conn *
868 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
870 unsigned int dataoff,
873 struct nf_conntrack_l3proto *l3proto,
874 struct nf_conntrack_l4proto *l4proto,
876 enum ip_conntrack_info *ctinfo)
878 struct nf_conntrack_tuple tuple;
879 struct nf_conntrack_tuple_hash *h;
881 u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
884 if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
885 dataoff, l3num, protonum, &tuple, l3proto,
887 pr_debug("resolve_normal_ct: Can't get tuple\n");
891 /* look for tuple match */
892 hash = hash_conntrack_raw(&tuple, zone);
893 h = __nf_conntrack_find_get(net, zone, &tuple, hash);
895 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
902 ct = nf_ct_tuplehash_to_ctrack(h);
904 /* It exists; we have (non-exclusive) reference. */
905 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
906 *ctinfo = IP_CT_ESTABLISHED_REPLY;
907 /* Please set reply bit if this packet OK */
910 /* Once we've had two way comms, always ESTABLISHED. */
911 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
912 pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
913 *ctinfo = IP_CT_ESTABLISHED;
914 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
915 pr_debug("nf_conntrack_in: related packet for %p\n",
917 *ctinfo = IP_CT_RELATED;
919 pr_debug("nf_conntrack_in: new packet for %p\n", ct);
924 skb->nfct = &ct->ct_general;
925 skb->nfctinfo = *ctinfo;
930 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
933 struct nf_conn *ct, *tmpl = NULL;
934 enum ip_conntrack_info ctinfo;
935 struct nf_conntrack_l3proto *l3proto;
936 struct nf_conntrack_l4proto *l4proto;
937 unsigned int *timeouts;
938 unsigned int dataoff;
944 /* Previously seen (loopback or untracked)? Ignore. */
945 tmpl = (struct nf_conn *)skb->nfct;
946 if (!nf_ct_is_template(tmpl)) {
947 NF_CT_STAT_INC_ATOMIC(net, ignore);
953 /* rcu_read_lock()ed by nf_hook_slow */
954 l3proto = __nf_ct_l3proto_find(pf);
955 ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
956 &dataoff, &protonum);
958 pr_debug("not prepared to track yet or error occurred\n");
959 NF_CT_STAT_INC_ATOMIC(net, error);
960 NF_CT_STAT_INC_ATOMIC(net, invalid);
965 l4proto = __nf_ct_l4proto_find(pf, protonum);
967 /* It may be an special packet, error, unclean...
968 * inverse of the return code tells to the netfilter
969 * core what to do with the packet. */
970 if (l4proto->error != NULL) {
971 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
974 NF_CT_STAT_INC_ATOMIC(net, error);
975 NF_CT_STAT_INC_ATOMIC(net, invalid);
979 /* ICMP[v6] protocol trackers may assign one conntrack. */
984 ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
985 l3proto, l4proto, &set_reply, &ctinfo);
987 /* Not valid part of a connection */
988 NF_CT_STAT_INC_ATOMIC(net, invalid);
994 /* Too stressed to deal. */
995 NF_CT_STAT_INC_ATOMIC(net, drop);
1000 NF_CT_ASSERT(skb->nfct);
1002 /* Decide what timeout policy we want to apply to this flow. */
1003 timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
1005 ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
1007 /* Invalid: inverse of the return code tells
1008 * the netfilter core what to do */
1009 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1010 nf_conntrack_put(skb->nfct);
1012 NF_CT_STAT_INC_ATOMIC(net, invalid);
1013 if (ret == -NF_DROP)
1014 NF_CT_STAT_INC_ATOMIC(net, drop);
1019 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1020 nf_conntrack_event_cache(IPCT_REPLY, ct);
1023 /* Special case: we have to repeat this hook, assign the
1024 * template again to this packet. We assume that this packet
1025 * has no conntrack assigned. This is used by nf_ct_tcp. */
1026 if (ret == NF_REPEAT)
1027 skb->nfct = (struct nf_conntrack *)tmpl;
1034 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1036 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
1037 const struct nf_conntrack_tuple *orig)
1042 ret = nf_ct_invert_tuple(inverse, orig,
1043 __nf_ct_l3proto_find(orig->src.l3num),
1044 __nf_ct_l4proto_find(orig->src.l3num,
1045 orig->dst.protonum));
1049 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
1051 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1052 implicitly racy: see __nf_conntrack_confirm */
1053 void nf_conntrack_alter_reply(struct nf_conn *ct,
1054 const struct nf_conntrack_tuple *newreply)
1056 struct nf_conn_help *help = nfct_help(ct);
1058 /* Should be unconfirmed, so not in hash table yet */
1059 NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
1061 pr_debug("Altering reply tuple of %p to ", ct);
1062 nf_ct_dump_tuple(newreply);
1064 ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1065 if (ct->master || (help && !hlist_empty(&help->expectations)))
1069 __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1072 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1074 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1075 void __nf_ct_refresh_acct(struct nf_conn *ct,
1076 enum ip_conntrack_info ctinfo,
1077 const struct sk_buff *skb,
1078 unsigned long extra_jiffies,
1081 NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
1084 /* Only update if this is not a fixed timeout */
1085 if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1088 /* If not in hash table, timer will not be active yet */
1089 if (!nf_ct_is_confirmed(ct)) {
1090 ct->timeout.expires = extra_jiffies;
1092 unsigned long newtime = jiffies + extra_jiffies;
1094 /* Only update the timeout if the new timeout is at least
1095 HZ jiffies from the old timeout. Need del_timer for race
1096 avoidance (may already be dying). */
1097 if (newtime - ct->timeout.expires >= HZ)
1098 mod_timer_pending(&ct->timeout, newtime);
1103 struct nf_conn_counter *acct;
1105 acct = nf_conn_acct_find(ct);
1107 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1108 atomic64_add(skb->len, &acct[CTINFO2DIR(ctinfo)].bytes);
1112 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1114 bool __nf_ct_kill_acct(struct nf_conn *ct,
1115 enum ip_conntrack_info ctinfo,
1116 const struct sk_buff *skb,
1120 struct nf_conn_counter *acct;
1122 acct = nf_conn_acct_find(ct);
1124 atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets);
1125 atomic64_add(skb->len - skb_network_offset(skb),
1126 &acct[CTINFO2DIR(ctinfo)].bytes);
1130 if (del_timer(&ct->timeout)) {
1131 ct->timeout.function((unsigned long)ct);
1136 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
1138 #ifdef CONFIG_NF_CONNTRACK_ZONES
1139 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
1140 .len = sizeof(struct nf_conntrack_zone),
1141 .align = __alignof__(struct nf_conntrack_zone),
1142 .id = NF_CT_EXT_ZONE,
1146 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1148 #include <linux/netfilter/nfnetlink.h>
1149 #include <linux/netfilter/nfnetlink_conntrack.h>
1150 #include <linux/mutex.h>
1152 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1153 * in ip_conntrack_core, since we don't want the protocols to autoload
1154 * or depend on ctnetlink */
1155 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1156 const struct nf_conntrack_tuple *tuple)
1158 if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1159 nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1160 goto nla_put_failure;
1166 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1168 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1169 [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
1170 [CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
1172 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1174 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1175 struct nf_conntrack_tuple *t)
1177 if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1180 t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1181 t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1185 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1187 int nf_ct_port_nlattr_tuple_size(void)
1189 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1191 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1194 /* Used by ipt_REJECT and ip6t_REJECT. */
1195 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1198 enum ip_conntrack_info ctinfo;
1200 /* This ICMP is in reverse direction to the packet which caused it */
1201 ct = nf_ct_get(skb, &ctinfo);
1202 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1203 ctinfo = IP_CT_RELATED_REPLY;
1205 ctinfo = IP_CT_RELATED;
1207 /* Attach to new skbuff, and increment count */
1208 nskb->nfct = &ct->ct_general;
1209 nskb->nfctinfo = ctinfo;
1210 nf_conntrack_get(nskb->nfct);
1213 /* Bring out ya dead! */
1214 static struct nf_conn *
1215 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1216 void *data, unsigned int *bucket)
1218 struct nf_conntrack_tuple_hash *h;
1220 struct hlist_nulls_node *n;
1222 spin_lock_bh(&nf_conntrack_lock);
1223 for (; *bucket < net->ct.htable_size; (*bucket)++) {
1224 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1225 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1227 ct = nf_ct_tuplehash_to_ctrack(h);
1232 hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
1233 ct = nf_ct_tuplehash_to_ctrack(h);
1235 set_bit(IPS_DYING_BIT, &ct->status);
1237 spin_unlock_bh(&nf_conntrack_lock);
1240 atomic_inc(&ct->ct_general.use);
1241 spin_unlock_bh(&nf_conntrack_lock);
1245 void nf_ct_iterate_cleanup(struct net *net,
1246 int (*iter)(struct nf_conn *i, void *data),
1250 unsigned int bucket = 0;
1252 while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1253 /* Time to push up daises... */
1254 if (del_timer(&ct->timeout))
1255 death_by_timeout((unsigned long)ct);
1256 /* ... else the timer will get him soon. */
1261 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1263 struct __nf_ct_flush_report {
1268 static int kill_report(struct nf_conn *i, void *data)
1270 struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1271 struct nf_conn_tstamp *tstamp;
1273 tstamp = nf_conn_tstamp_find(i);
1274 if (tstamp && tstamp->stop == 0)
1275 tstamp->stop = ktime_to_ns(ktime_get_real());
1277 /* If we fail to deliver the event, death_by_timeout() will retry */
1278 if (nf_conntrack_event_report(IPCT_DESTROY, i,
1279 fr->portid, fr->report) < 0)
1282 /* Avoid the delivery of the destroy event in death_by_timeout(). */
1283 set_bit(IPS_DYING_BIT, &i->status);
1287 static int kill_all(struct nf_conn *i, void *data)
1292 void nf_ct_free_hashtable(void *hash, unsigned int size)
1294 if (is_vmalloc_addr(hash))
1297 free_pages((unsigned long)hash,
1298 get_order(sizeof(struct hlist_head) * size));
1300 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1302 void nf_conntrack_flush_report(struct net *net, u32 portid, int report)
1304 struct __nf_ct_flush_report fr = {
1308 nf_ct_iterate_cleanup(net, kill_report, &fr);
1310 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1312 static void nf_ct_release_dying_list(struct net *net)
1314 struct nf_conntrack_tuple_hash *h;
1316 struct hlist_nulls_node *n;
1318 spin_lock_bh(&nf_conntrack_lock);
1319 hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
1320 ct = nf_ct_tuplehash_to_ctrack(h);
1321 /* never fails to remove them, no listeners at this point */
1324 spin_unlock_bh(&nf_conntrack_lock);
1327 static int untrack_refs(void)
1331 for_each_possible_cpu(cpu) {
1332 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1334 cnt += atomic_read(&ct->ct_general.use) - 1;
1339 void nf_conntrack_cleanup_start(void)
1341 RCU_INIT_POINTER(ip_ct_attach, NULL);
1344 void nf_conntrack_cleanup_end(void)
1346 RCU_INIT_POINTER(nf_ct_destroy, NULL);
1347 while (untrack_refs() > 0)
1350 #ifdef CONFIG_NF_CONNTRACK_ZONES
1351 nf_ct_extend_unregister(&nf_ct_zone_extend);
1353 nf_conntrack_proto_fini();
1354 nf_conntrack_labels_fini();
1355 nf_conntrack_helper_fini();
1356 nf_conntrack_timeout_fini();
1357 nf_conntrack_ecache_fini();
1358 nf_conntrack_tstamp_fini();
1359 nf_conntrack_acct_fini();
1360 nf_conntrack_expect_fini();
1364 * Mishearing the voices in his head, our hero wonders how he's
1365 * supposed to kill the mall.
1367 void nf_conntrack_cleanup_net(struct net *net)
1371 list_add(&net->exit_list, &single);
1372 nf_conntrack_cleanup_net_list(&single);
1375 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
1381 * This makes sure all current packets have passed through
1382 * netfilter framework. Roll on, two-stage module
1388 list_for_each_entry(net, net_exit_list, exit_list) {
1389 nf_ct_iterate_cleanup(net, kill_all, NULL);
1390 nf_ct_release_dying_list(net);
1391 if (atomic_read(&net->ct.count) != 0)
1396 goto i_see_dead_people;
1399 list_for_each_entry(net, net_exit_list, exit_list) {
1400 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1401 nf_conntrack_proto_pernet_fini(net);
1402 nf_conntrack_helper_pernet_fini(net);
1403 nf_conntrack_ecache_pernet_fini(net);
1404 nf_conntrack_tstamp_pernet_fini(net);
1405 nf_conntrack_acct_pernet_fini(net);
1406 nf_conntrack_expect_pernet_fini(net);
1407 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1408 kfree(net->ct.slabname);
1409 free_percpu(net->ct.stat);
1413 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
1415 struct hlist_nulls_head *hash;
1416 unsigned int nr_slots, i;
1419 BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1420 nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1421 sz = nr_slots * sizeof(struct hlist_nulls_head);
1422 hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1425 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1430 for (i = 0; i < nr_slots; i++)
1431 INIT_HLIST_NULLS_HEAD(&hash[i], i);
1435 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1437 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1440 unsigned int hashsize, old_size;
1441 struct hlist_nulls_head *hash, *old_hash;
1442 struct nf_conntrack_tuple_hash *h;
1445 if (current->nsproxy->net_ns != &init_net)
1448 /* On boot, we can set this without any fancy locking. */
1449 if (!nf_conntrack_htable_size)
1450 return param_set_uint(val, kp);
1452 rc = kstrtouint(val, 0, &hashsize);
1458 hash = nf_ct_alloc_hashtable(&hashsize, 1);
1462 /* Lookups in the old hash might happen in parallel, which means we
1463 * might get false negatives during connection lookup. New connections
1464 * created because of a false negative won't make it into the hash
1465 * though since that required taking the lock.
1467 spin_lock_bh(&nf_conntrack_lock);
1468 for (i = 0; i < init_net.ct.htable_size; i++) {
1469 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1470 h = hlist_nulls_entry(init_net.ct.hash[i].first,
1471 struct nf_conntrack_tuple_hash, hnnode);
1472 ct = nf_ct_tuplehash_to_ctrack(h);
1473 hlist_nulls_del_rcu(&h->hnnode);
1474 bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1476 hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1479 old_size = init_net.ct.htable_size;
1480 old_hash = init_net.ct.hash;
1482 init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1483 init_net.ct.hash = hash;
1484 spin_unlock_bh(&nf_conntrack_lock);
1486 nf_ct_free_hashtable(old_hash, old_size);
1489 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1491 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1492 &nf_conntrack_htable_size, 0600);
1494 void nf_ct_untracked_status_or(unsigned long bits)
1498 for_each_possible_cpu(cpu)
1499 per_cpu(nf_conntrack_untracked, cpu).status |= bits;
1501 EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
1503 int nf_conntrack_init_start(void)
1508 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1509 * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1510 if (!nf_conntrack_htable_size) {
1511 nf_conntrack_htable_size
1512 = (((totalram_pages << PAGE_SHIFT) / 16384)
1513 / sizeof(struct hlist_head));
1514 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1515 nf_conntrack_htable_size = 16384;
1516 if (nf_conntrack_htable_size < 32)
1517 nf_conntrack_htable_size = 32;
1519 /* Use a max. factor of four by default to get the same max as
1520 * with the old struct list_heads. When a table size is given
1521 * we use the old value of 8 to avoid reducing the max.
1525 nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1527 printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
1528 NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1531 ret = nf_conntrack_expect_init();
1535 ret = nf_conntrack_acct_init();
1539 ret = nf_conntrack_tstamp_init();
1543 ret = nf_conntrack_ecache_init();
1547 ret = nf_conntrack_timeout_init();
1551 ret = nf_conntrack_helper_init();
1555 ret = nf_conntrack_labels_init();
1559 #ifdef CONFIG_NF_CONNTRACK_ZONES
1560 ret = nf_ct_extend_register(&nf_ct_zone_extend);
1564 ret = nf_conntrack_proto_init();
1568 /* Set up fake conntrack: to never be deleted, not in any hashes */
1569 for_each_possible_cpu(cpu) {
1570 struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
1571 write_pnet(&ct->ct_net, &init_net);
1572 atomic_set(&ct->ct_general.use, 1);
1574 /* - and look it like as a confirmed connection */
1575 nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
1579 #ifdef CONFIG_NF_CONNTRACK_ZONES
1580 nf_ct_extend_unregister(&nf_ct_zone_extend);
1583 nf_conntrack_labels_fini();
1585 nf_conntrack_helper_fini();
1587 nf_conntrack_timeout_fini();
1589 nf_conntrack_ecache_fini();
1591 nf_conntrack_tstamp_fini();
1593 nf_conntrack_acct_fini();
1595 nf_conntrack_expect_fini();
1600 void nf_conntrack_init_end(void)
1602 /* For use by REJECT target */
1603 RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
1604 RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
1606 /* Howto get NAT offsets */
1607 RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
1611 * We need to use special "null" values, not used in hash table
1613 #define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
1614 #define DYING_NULLS_VAL ((1<<30)+1)
1615 #define TEMPLATE_NULLS_VAL ((1<<30)+2)
1617 int nf_conntrack_init_net(struct net *net)
1621 atomic_set(&net->ct.count, 0);
1622 INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
1623 INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
1624 INIT_HLIST_NULLS_HEAD(&net->ct.tmpl, TEMPLATE_NULLS_VAL);
1625 net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1626 if (!net->ct.stat) {
1631 net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1632 if (!net->ct.slabname) {
1637 net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1638 sizeof(struct nf_conn), 0,
1639 SLAB_DESTROY_BY_RCU, NULL);
1640 if (!net->ct.nf_conntrack_cachep) {
1641 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1646 net->ct.htable_size = nf_conntrack_htable_size;
1647 net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
1648 if (!net->ct.hash) {
1650 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1653 ret = nf_conntrack_expect_pernet_init(net);
1656 ret = nf_conntrack_acct_pernet_init(net);
1659 ret = nf_conntrack_tstamp_pernet_init(net);
1662 ret = nf_conntrack_ecache_pernet_init(net);
1665 ret = nf_conntrack_helper_pernet_init(net);
1668 ret = nf_conntrack_proto_pernet_init(net);
1674 nf_conntrack_helper_pernet_fini(net);
1676 nf_conntrack_ecache_pernet_fini(net);
1678 nf_conntrack_tstamp_pernet_fini(net);
1680 nf_conntrack_acct_pernet_fini(net);
1682 nf_conntrack_expect_pernet_fini(net);
1684 nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
1686 kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1688 kfree(net->ct.slabname);
1690 free_percpu(net->ct.stat);
1695 s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
1696 enum ip_conntrack_dir dir,
1698 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);