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) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
13 * - new API and handling of conntrack/nat helpers
14 * - now capable of multiple expectations for one master
15 * 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
16 * - add usage/reference counts to ip_conntrack_expect
17 * - export ip_conntrack[_expect]_{find_get,put} functions
20 #include <linux/config.h>
21 #include <linux/types.h>
22 #include <linux/icmp.h>
24 #include <linux/netfilter.h>
25 #include <linux/netfilter_ipv4.h>
26 #include <linux/module.h>
27 #include <linux/skbuff.h>
28 #include <linux/proc_fs.h>
29 #include <linux/vmalloc.h>
30 #include <net/checksum.h>
32 #include <linux/stddef.h>
33 #include <linux/sysctl.h>
34 #include <linux/slab.h>
35 #include <linux/random.h>
36 #include <linux/jhash.h>
37 #include <linux/err.h>
38 #include <linux/percpu.h>
39 #include <linux/moduleparam.h>
40 #include <linux/notifier.h>
42 /* ip_conntrack_lock protects the main hash table, protocol/helper/expected
43 registrations, conntrack timers*/
44 #define ASSERT_READ_LOCK(x)
45 #define ASSERT_WRITE_LOCK(x)
47 #include <linux/netfilter_ipv4/ip_conntrack.h>
48 #include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
49 #include <linux/netfilter_ipv4/ip_conntrack_helper.h>
50 #include <linux/netfilter_ipv4/ip_conntrack_core.h>
51 #include <linux/netfilter_ipv4/listhelp.h>
53 #define IP_CONNTRACK_VERSION "2.4"
58 #define DEBUGP(format, args...)
61 DEFINE_RWLOCK(ip_conntrack_lock);
63 /* ip_conntrack_standalone needs this */
64 atomic_t ip_conntrack_count = ATOMIC_INIT(0);
66 void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack) = NULL;
67 LIST_HEAD(ip_conntrack_expect_list);
68 struct ip_conntrack_protocol *ip_ct_protos[MAX_IP_CT_PROTO];
69 static LIST_HEAD(helpers);
70 unsigned int ip_conntrack_htable_size = 0;
72 struct list_head *ip_conntrack_hash;
73 static kmem_cache_t *ip_conntrack_cachep __read_mostly;
74 static kmem_cache_t *ip_conntrack_expect_cachep __read_mostly;
75 struct ip_conntrack ip_conntrack_untracked;
76 unsigned int ip_ct_log_invalid;
77 static LIST_HEAD(unconfirmed);
78 static int ip_conntrack_vmalloc;
80 static unsigned int ip_conntrack_next_id = 1;
81 static unsigned int ip_conntrack_expect_next_id = 1;
82 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
83 struct notifier_block *ip_conntrack_chain;
84 struct notifier_block *ip_conntrack_expect_chain;
86 DEFINE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache);
88 /* deliver cached events and clear cache entry - must be called with locally
89 * disabled softirqs */
91 __ip_ct_deliver_cached_events(struct ip_conntrack_ecache *ecache)
93 DEBUGP("ecache: delivering events for %p\n", ecache->ct);
94 if (is_confirmed(ecache->ct) && !is_dying(ecache->ct) && ecache->events)
95 notifier_call_chain(&ip_conntrack_chain, ecache->events,
98 ip_conntrack_put(ecache->ct);
102 /* Deliver all cached events for a particular conntrack. This is called
103 * by code prior to async packet handling or freeing the skb */
104 void ip_ct_deliver_cached_events(const struct ip_conntrack *ct)
106 struct ip_conntrack_ecache *ecache;
109 ecache = &__get_cpu_var(ip_conntrack_ecache);
110 if (ecache->ct == ct)
111 __ip_ct_deliver_cached_events(ecache);
115 void __ip_ct_event_cache_init(struct ip_conntrack *ct)
117 struct ip_conntrack_ecache *ecache;
119 /* take care of delivering potentially old events */
120 ecache = &__get_cpu_var(ip_conntrack_ecache);
121 BUG_ON(ecache->ct == ct);
123 __ip_ct_deliver_cached_events(ecache);
124 /* initialize for this conntrack/packet */
126 nf_conntrack_get(&ct->ct_general);
129 /* flush the event cache - touches other CPU's data and must not be called while
130 * packets are still passing through the code */
131 static void ip_ct_event_cache_flush(void)
133 struct ip_conntrack_ecache *ecache;
137 ecache = &per_cpu(ip_conntrack_ecache, cpu);
139 ip_conntrack_put(ecache->ct);
143 static inline void ip_ct_event_cache_flush(void) {}
144 #endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
146 DEFINE_PER_CPU(struct ip_conntrack_stat, ip_conntrack_stat);
148 static int ip_conntrack_hash_rnd_initted;
149 static unsigned int ip_conntrack_hash_rnd;
151 static u_int32_t __hash_conntrack(const struct ip_conntrack_tuple *tuple,
152 unsigned int size, unsigned int rnd)
154 return (jhash_3words(tuple->src.ip,
155 (tuple->dst.ip ^ tuple->dst.protonum),
156 (tuple->src.u.all | (tuple->dst.u.all << 16)),
161 hash_conntrack(const struct ip_conntrack_tuple *tuple)
163 return __hash_conntrack(tuple, ip_conntrack_htable_size,
164 ip_conntrack_hash_rnd);
168 ip_ct_get_tuple(const struct iphdr *iph,
169 const struct sk_buff *skb,
170 unsigned int dataoff,
171 struct ip_conntrack_tuple *tuple,
172 const struct ip_conntrack_protocol *protocol)
175 if (iph->frag_off & htons(IP_OFFSET)) {
176 printk("ip_conntrack_core: Frag of proto %u.\n",
181 tuple->src.ip = iph->saddr;
182 tuple->dst.ip = iph->daddr;
183 tuple->dst.protonum = iph->protocol;
184 tuple->dst.dir = IP_CT_DIR_ORIGINAL;
186 return protocol->pkt_to_tuple(skb, dataoff, tuple);
190 ip_ct_invert_tuple(struct ip_conntrack_tuple *inverse,
191 const struct ip_conntrack_tuple *orig,
192 const struct ip_conntrack_protocol *protocol)
194 inverse->src.ip = orig->dst.ip;
195 inverse->dst.ip = orig->src.ip;
196 inverse->dst.protonum = orig->dst.protonum;
197 inverse->dst.dir = !orig->dst.dir;
199 return protocol->invert_tuple(inverse, orig);
203 /* ip_conntrack_expect helper functions */
204 void ip_ct_unlink_expect(struct ip_conntrack_expect *exp)
206 ASSERT_WRITE_LOCK(&ip_conntrack_lock);
207 IP_NF_ASSERT(!timer_pending(&exp->timeout));
208 list_del(&exp->list);
209 CONNTRACK_STAT_INC(expect_delete);
210 exp->master->expecting--;
211 ip_conntrack_expect_put(exp);
214 static void expectation_timed_out(unsigned long ul_expect)
216 struct ip_conntrack_expect *exp = (void *)ul_expect;
218 write_lock_bh(&ip_conntrack_lock);
219 ip_ct_unlink_expect(exp);
220 write_unlock_bh(&ip_conntrack_lock);
221 ip_conntrack_expect_put(exp);
224 struct ip_conntrack_expect *
225 __ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple)
227 struct ip_conntrack_expect *i;
229 list_for_each_entry(i, &ip_conntrack_expect_list, list) {
230 if (ip_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) {
238 /* Just find a expectation corresponding to a tuple. */
239 struct ip_conntrack_expect *
240 ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple)
242 struct ip_conntrack_expect *i;
244 read_lock_bh(&ip_conntrack_lock);
245 i = __ip_conntrack_expect_find(tuple);
246 read_unlock_bh(&ip_conntrack_lock);
251 /* If an expectation for this connection is found, it gets delete from
252 * global list then returned. */
253 static struct ip_conntrack_expect *
254 find_expectation(const struct ip_conntrack_tuple *tuple)
256 struct ip_conntrack_expect *i;
258 list_for_each_entry(i, &ip_conntrack_expect_list, list) {
259 /* If master is not in hash table yet (ie. packet hasn't left
260 this machine yet), how can other end know about expected?
261 Hence these are not the droids you are looking for (if
262 master ct never got confirmed, we'd hold a reference to it
263 and weird things would happen to future packets). */
264 if (ip_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)
265 && is_confirmed(i->master)) {
266 if (i->flags & IP_CT_EXPECT_PERMANENT) {
269 } else if (del_timer(&i->timeout)) {
270 ip_ct_unlink_expect(i);
278 /* delete all expectations for this conntrack */
279 void ip_ct_remove_expectations(struct ip_conntrack *ct)
281 struct ip_conntrack_expect *i, *tmp;
283 /* Optimization: most connection never expect any others. */
284 if (ct->expecting == 0)
287 list_for_each_entry_safe(i, tmp, &ip_conntrack_expect_list, list) {
288 if (i->master == ct && del_timer(&i->timeout)) {
289 ip_ct_unlink_expect(i);
290 ip_conntrack_expect_put(i);
296 clean_from_lists(struct ip_conntrack *ct)
300 DEBUGP("clean_from_lists(%p)\n", ct);
301 ASSERT_WRITE_LOCK(&ip_conntrack_lock);
303 ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
304 hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
305 LIST_DELETE(&ip_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]);
306 LIST_DELETE(&ip_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]);
308 /* Destroy all pending expectations */
309 ip_ct_remove_expectations(ct);
313 destroy_conntrack(struct nf_conntrack *nfct)
315 struct ip_conntrack *ct = (struct ip_conntrack *)nfct;
316 struct ip_conntrack_protocol *proto;
318 DEBUGP("destroy_conntrack(%p)\n", ct);
319 IP_NF_ASSERT(atomic_read(&nfct->use) == 0);
320 IP_NF_ASSERT(!timer_pending(&ct->timeout));
322 ip_conntrack_event(IPCT_DESTROY, ct);
323 set_bit(IPS_DYING_BIT, &ct->status);
325 /* To make sure we don't get any weird locking issues here:
326 * destroy_conntrack() MUST NOT be called with a write lock
327 * to ip_conntrack_lock!!! -HW */
328 proto = __ip_conntrack_proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
329 if (proto && proto->destroy)
332 if (ip_conntrack_destroyed)
333 ip_conntrack_destroyed(ct);
335 write_lock_bh(&ip_conntrack_lock);
336 /* Expectations will have been removed in clean_from_lists,
337 * except TFTP can create an expectation on the first packet,
338 * before connection is in the list, so we need to clean here,
340 ip_ct_remove_expectations(ct);
342 /* We overload first tuple to link into unconfirmed list. */
343 if (!is_confirmed(ct)) {
344 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
345 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
348 CONNTRACK_STAT_INC(delete);
349 write_unlock_bh(&ip_conntrack_lock);
352 ip_conntrack_put(ct->master);
354 DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
355 ip_conntrack_free(ct);
358 static void death_by_timeout(unsigned long ul_conntrack)
360 struct ip_conntrack *ct = (void *)ul_conntrack;
362 write_lock_bh(&ip_conntrack_lock);
363 /* Inside lock so preempt is disabled on module removal path.
364 * Otherwise we can get spurious warnings. */
365 CONNTRACK_STAT_INC(delete_list);
366 clean_from_lists(ct);
367 write_unlock_bh(&ip_conntrack_lock);
368 ip_conntrack_put(ct);
372 conntrack_tuple_cmp(const struct ip_conntrack_tuple_hash *i,
373 const struct ip_conntrack_tuple *tuple,
374 const struct ip_conntrack *ignored_conntrack)
376 ASSERT_READ_LOCK(&ip_conntrack_lock);
377 return tuplehash_to_ctrack(i) != ignored_conntrack
378 && ip_ct_tuple_equal(tuple, &i->tuple);
381 struct ip_conntrack_tuple_hash *
382 __ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
383 const struct ip_conntrack *ignored_conntrack)
385 struct ip_conntrack_tuple_hash *h;
386 unsigned int hash = hash_conntrack(tuple);
388 ASSERT_READ_LOCK(&ip_conntrack_lock);
389 list_for_each_entry(h, &ip_conntrack_hash[hash], list) {
390 if (conntrack_tuple_cmp(h, tuple, ignored_conntrack)) {
391 CONNTRACK_STAT_INC(found);
394 CONNTRACK_STAT_INC(searched);
400 /* Find a connection corresponding to a tuple. */
401 struct ip_conntrack_tuple_hash *
402 ip_conntrack_find_get(const struct ip_conntrack_tuple *tuple,
403 const struct ip_conntrack *ignored_conntrack)
405 struct ip_conntrack_tuple_hash *h;
407 read_lock_bh(&ip_conntrack_lock);
408 h = __ip_conntrack_find(tuple, ignored_conntrack);
410 atomic_inc(&tuplehash_to_ctrack(h)->ct_general.use);
411 read_unlock_bh(&ip_conntrack_lock);
416 static void __ip_conntrack_hash_insert(struct ip_conntrack *ct,
418 unsigned int repl_hash)
420 ct->id = ++ip_conntrack_next_id;
421 list_prepend(&ip_conntrack_hash[hash],
422 &ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
423 list_prepend(&ip_conntrack_hash[repl_hash],
424 &ct->tuplehash[IP_CT_DIR_REPLY].list);
427 void ip_conntrack_hash_insert(struct ip_conntrack *ct)
429 unsigned int hash, repl_hash;
431 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
432 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
434 write_lock_bh(&ip_conntrack_lock);
435 __ip_conntrack_hash_insert(ct, hash, repl_hash);
436 write_unlock_bh(&ip_conntrack_lock);
439 /* Confirm a connection given skb; places it in hash table */
441 __ip_conntrack_confirm(struct sk_buff **pskb)
443 unsigned int hash, repl_hash;
444 struct ip_conntrack *ct;
445 enum ip_conntrack_info ctinfo;
447 ct = ip_conntrack_get(*pskb, &ctinfo);
449 /* ipt_REJECT uses ip_conntrack_attach to attach related
450 ICMP/TCP RST packets in other direction. Actual packet
451 which created connection will be IP_CT_NEW or for an
452 expected connection, IP_CT_RELATED. */
453 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
456 hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
457 repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
459 /* We're not in hash table, and we refuse to set up related
460 connections for unconfirmed conns. But packet copies and
461 REJECT will give spurious warnings here. */
462 /* IP_NF_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
464 /* No external references means noone else could have
466 IP_NF_ASSERT(!is_confirmed(ct));
467 DEBUGP("Confirming conntrack %p\n", ct);
469 write_lock_bh(&ip_conntrack_lock);
471 /* See if there's one in the list already, including reverse:
472 NAT could have grabbed it without realizing, since we're
473 not in the hash. If there is, we lost race. */
474 if (!LIST_FIND(&ip_conntrack_hash[hash],
476 struct ip_conntrack_tuple_hash *,
477 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL)
478 && !LIST_FIND(&ip_conntrack_hash[repl_hash],
480 struct ip_conntrack_tuple_hash *,
481 &ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) {
482 /* Remove from unconfirmed list */
483 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
485 __ip_conntrack_hash_insert(ct, hash, repl_hash);
486 /* Timer relative to confirmation time, not original
487 setting time, otherwise we'd get timer wrap in
488 weird delay cases. */
489 ct->timeout.expires += jiffies;
490 add_timer(&ct->timeout);
491 atomic_inc(&ct->ct_general.use);
492 set_bit(IPS_CONFIRMED_BIT, &ct->status);
493 CONNTRACK_STAT_INC(insert);
494 write_unlock_bh(&ip_conntrack_lock);
496 ip_conntrack_event_cache(IPCT_HELPER, *pskb);
497 #ifdef CONFIG_IP_NF_NAT_NEEDED
498 if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
499 test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
500 ip_conntrack_event_cache(IPCT_NATINFO, *pskb);
502 ip_conntrack_event_cache(master_ct(ct) ?
503 IPCT_RELATED : IPCT_NEW, *pskb);
508 CONNTRACK_STAT_INC(insert_failed);
509 write_unlock_bh(&ip_conntrack_lock);
514 /* Returns true if a connection correspondings to the tuple (required
517 ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
518 const struct ip_conntrack *ignored_conntrack)
520 struct ip_conntrack_tuple_hash *h;
522 read_lock_bh(&ip_conntrack_lock);
523 h = __ip_conntrack_find(tuple, ignored_conntrack);
524 read_unlock_bh(&ip_conntrack_lock);
529 /* There's a small race here where we may free a just-assured
530 connection. Too bad: we're in trouble anyway. */
531 static inline int unreplied(const struct ip_conntrack_tuple_hash *i)
533 return !(test_bit(IPS_ASSURED_BIT, &tuplehash_to_ctrack(i)->status));
536 static int early_drop(struct list_head *chain)
538 /* Traverse backwards: gives us oldest, which is roughly LRU */
539 struct ip_conntrack_tuple_hash *h;
540 struct ip_conntrack *ct = NULL;
543 read_lock_bh(&ip_conntrack_lock);
544 h = LIST_FIND_B(chain, unreplied, struct ip_conntrack_tuple_hash *);
546 ct = tuplehash_to_ctrack(h);
547 atomic_inc(&ct->ct_general.use);
549 read_unlock_bh(&ip_conntrack_lock);
554 if (del_timer(&ct->timeout)) {
555 death_by_timeout((unsigned long)ct);
557 CONNTRACK_STAT_INC(early_drop);
559 ip_conntrack_put(ct);
563 static inline int helper_cmp(const struct ip_conntrack_helper *i,
564 const struct ip_conntrack_tuple *rtuple)
566 return ip_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask);
569 static struct ip_conntrack_helper *
570 __ip_conntrack_helper_find( const struct ip_conntrack_tuple *tuple)
572 return LIST_FIND(&helpers, helper_cmp,
573 struct ip_conntrack_helper *,
577 struct ip_conntrack_helper *
578 ip_conntrack_helper_find_get( const struct ip_conntrack_tuple *tuple)
580 struct ip_conntrack_helper *helper;
582 /* need ip_conntrack_lock to assure that helper exists until
583 * try_module_get() is called */
584 read_lock_bh(&ip_conntrack_lock);
586 helper = __ip_conntrack_helper_find(tuple);
588 /* need to increase module usage count to assure helper will
589 * not go away while the caller is e.g. busy putting a
590 * conntrack in the hash that uses the helper */
591 if (!try_module_get(helper->me))
595 read_unlock_bh(&ip_conntrack_lock);
600 void ip_conntrack_helper_put(struct ip_conntrack_helper *helper)
602 module_put(helper->me);
605 struct ip_conntrack_protocol *
606 __ip_conntrack_proto_find(u_int8_t protocol)
608 return ip_ct_protos[protocol];
611 /* this is guaranteed to always return a valid protocol helper, since
612 * it falls back to generic_protocol */
613 struct ip_conntrack_protocol *
614 ip_conntrack_proto_find_get(u_int8_t protocol)
616 struct ip_conntrack_protocol *p;
619 p = __ip_conntrack_proto_find(protocol);
621 if (!try_module_get(p->me))
622 p = &ip_conntrack_generic_protocol;
629 void ip_conntrack_proto_put(struct ip_conntrack_protocol *p)
634 struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *orig,
635 struct ip_conntrack_tuple *repl)
637 struct ip_conntrack *conntrack;
639 if (!ip_conntrack_hash_rnd_initted) {
640 get_random_bytes(&ip_conntrack_hash_rnd, 4);
641 ip_conntrack_hash_rnd_initted = 1;
645 && atomic_read(&ip_conntrack_count) >= ip_conntrack_max) {
646 unsigned int hash = hash_conntrack(orig);
647 /* Try dropping from this hash chain. */
648 if (!early_drop(&ip_conntrack_hash[hash])) {
651 "ip_conntrack: table full, dropping"
653 return ERR_PTR(-ENOMEM);
657 conntrack = kmem_cache_alloc(ip_conntrack_cachep, GFP_ATOMIC);
659 DEBUGP("Can't allocate conntrack.\n");
660 return ERR_PTR(-ENOMEM);
663 memset(conntrack, 0, sizeof(*conntrack));
664 atomic_set(&conntrack->ct_general.use, 1);
665 conntrack->ct_general.destroy = destroy_conntrack;
666 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
667 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
668 /* Don't set timer yet: wait for confirmation */
669 init_timer(&conntrack->timeout);
670 conntrack->timeout.data = (unsigned long)conntrack;
671 conntrack->timeout.function = death_by_timeout;
673 atomic_inc(&ip_conntrack_count);
679 ip_conntrack_free(struct ip_conntrack *conntrack)
681 atomic_dec(&ip_conntrack_count);
682 kmem_cache_free(ip_conntrack_cachep, conntrack);
685 /* Allocate a new conntrack: we return -ENOMEM if classification
686 * failed due to stress. Otherwise it really is unclassifiable */
687 static struct ip_conntrack_tuple_hash *
688 init_conntrack(struct ip_conntrack_tuple *tuple,
689 struct ip_conntrack_protocol *protocol,
692 struct ip_conntrack *conntrack;
693 struct ip_conntrack_tuple repl_tuple;
694 struct ip_conntrack_expect *exp;
696 if (!ip_ct_invert_tuple(&repl_tuple, tuple, protocol)) {
697 DEBUGP("Can't invert tuple.\n");
701 conntrack = ip_conntrack_alloc(tuple, &repl_tuple);
702 if (conntrack == NULL || IS_ERR(conntrack))
703 return (struct ip_conntrack_tuple_hash *)conntrack;
705 if (!protocol->new(conntrack, skb)) {
706 ip_conntrack_free(conntrack);
710 write_lock_bh(&ip_conntrack_lock);
711 exp = find_expectation(tuple);
714 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
716 /* Welcome, Mr. Bond. We've been expecting you... */
717 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
718 conntrack->master = exp->master;
719 #ifdef CONFIG_IP_NF_CONNTRACK_MARK
720 conntrack->mark = exp->master->mark;
722 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
723 defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
724 /* this is ugly, but there is no other place where to put it */
725 conntrack->nat.masq_index = exp->master->nat.masq_index;
727 nf_conntrack_get(&conntrack->master->ct_general);
728 CONNTRACK_STAT_INC(expect_new);
730 conntrack->helper = __ip_conntrack_helper_find(&repl_tuple);
732 CONNTRACK_STAT_INC(new);
735 /* Overload tuple linked list to put us in unconfirmed list. */
736 list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
738 write_unlock_bh(&ip_conntrack_lock);
742 exp->expectfn(conntrack, exp);
743 ip_conntrack_expect_put(exp);
746 return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
749 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
750 static inline struct ip_conntrack *
751 resolve_normal_ct(struct sk_buff *skb,
752 struct ip_conntrack_protocol *proto,
754 unsigned int hooknum,
755 enum ip_conntrack_info *ctinfo)
757 struct ip_conntrack_tuple tuple;
758 struct ip_conntrack_tuple_hash *h;
759 struct ip_conntrack *ct;
761 IP_NF_ASSERT((skb->nh.iph->frag_off & htons(IP_OFFSET)) == 0);
763 if (!ip_ct_get_tuple(skb->nh.iph, skb, skb->nh.iph->ihl*4,
767 /* look for tuple match */
768 h = ip_conntrack_find_get(&tuple, NULL);
770 h = init_conntrack(&tuple, proto, skb);
776 ct = tuplehash_to_ctrack(h);
778 /* It exists; we have (non-exclusive) reference. */
779 if (DIRECTION(h) == IP_CT_DIR_REPLY) {
780 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
781 /* Please set reply bit if this packet OK */
784 /* Once we've had two way comms, always ESTABLISHED. */
785 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
786 DEBUGP("ip_conntrack_in: normal packet for %p\n",
788 *ctinfo = IP_CT_ESTABLISHED;
789 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
790 DEBUGP("ip_conntrack_in: related packet for %p\n",
792 *ctinfo = IP_CT_RELATED;
794 DEBUGP("ip_conntrack_in: new packet for %p\n",
800 skb->nfct = &ct->ct_general;
801 skb->nfctinfo = *ctinfo;
805 /* Netfilter hook itself. */
806 unsigned int ip_conntrack_in(unsigned int hooknum,
807 struct sk_buff **pskb,
808 const struct net_device *in,
809 const struct net_device *out,
810 int (*okfn)(struct sk_buff *))
812 struct ip_conntrack *ct;
813 enum ip_conntrack_info ctinfo;
814 struct ip_conntrack_protocol *proto;
818 /* Previously seen (loopback or untracked)? Ignore. */
820 CONNTRACK_STAT_INC(ignore);
825 if ((*pskb)->nh.iph->frag_off & htons(IP_OFFSET)) {
826 if (net_ratelimit()) {
827 printk(KERN_ERR "ip_conntrack_in: Frag of proto %u (hook=%u)\n",
828 (*pskb)->nh.iph->protocol, hooknum);
833 /* Doesn't cover locally-generated broadcast, so not worth it. */
835 /* Ignore broadcast: no `connection'. */
836 if ((*pskb)->pkt_type == PACKET_BROADCAST) {
837 printk("Broadcast packet!\n");
839 } else if (((*pskb)->nh.iph->daddr & htonl(0x000000FF))
840 == htonl(0x000000FF)) {
841 printk("Should bcast: %u.%u.%u.%u->%u.%u.%u.%u (sk=%p, ptype=%u)\n",
842 NIPQUAD((*pskb)->nh.iph->saddr),
843 NIPQUAD((*pskb)->nh.iph->daddr),
844 (*pskb)->sk, (*pskb)->pkt_type);
848 proto = __ip_conntrack_proto_find((*pskb)->nh.iph->protocol);
850 /* It may be an special packet, error, unclean...
851 * inverse of the return code tells to the netfilter
852 * core what to do with the packet. */
853 if (proto->error != NULL
854 && (ret = proto->error(*pskb, &ctinfo, hooknum)) <= 0) {
855 CONNTRACK_STAT_INC(error);
856 CONNTRACK_STAT_INC(invalid);
860 if (!(ct = resolve_normal_ct(*pskb, proto,&set_reply,hooknum,&ctinfo))) {
861 /* Not valid part of a connection */
862 CONNTRACK_STAT_INC(invalid);
867 /* Too stressed to deal. */
868 CONNTRACK_STAT_INC(drop);
872 IP_NF_ASSERT((*pskb)->nfct);
874 ret = proto->packet(ct, *pskb, ctinfo);
876 /* Invalid: inverse of the return code tells
877 * the netfilter core what to do*/
878 nf_conntrack_put((*pskb)->nfct);
879 (*pskb)->nfct = NULL;
880 CONNTRACK_STAT_INC(invalid);
884 if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
885 ip_conntrack_event_cache(IPCT_STATUS, *pskb);
890 int invert_tuplepr(struct ip_conntrack_tuple *inverse,
891 const struct ip_conntrack_tuple *orig)
893 return ip_ct_invert_tuple(inverse, orig,
894 __ip_conntrack_proto_find(orig->dst.protonum));
897 /* Would two expected things clash? */
898 static inline int expect_clash(const struct ip_conntrack_expect *a,
899 const struct ip_conntrack_expect *b)
901 /* Part covered by intersection of masks must be unequal,
902 otherwise they clash */
903 struct ip_conntrack_tuple intersect_mask
904 = { { a->mask.src.ip & b->mask.src.ip,
905 { a->mask.src.u.all & b->mask.src.u.all } },
906 { a->mask.dst.ip & b->mask.dst.ip,
907 { a->mask.dst.u.all & b->mask.dst.u.all },
908 a->mask.dst.protonum & b->mask.dst.protonum } };
910 return ip_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
913 static inline int expect_matches(const struct ip_conntrack_expect *a,
914 const struct ip_conntrack_expect *b)
916 return a->master == b->master
917 && ip_ct_tuple_equal(&a->tuple, &b->tuple)
918 && ip_ct_tuple_equal(&a->mask, &b->mask);
921 /* Generally a bad idea to call this: could have matched already. */
922 void ip_conntrack_unexpect_related(struct ip_conntrack_expect *exp)
924 struct ip_conntrack_expect *i;
926 write_lock_bh(&ip_conntrack_lock);
927 /* choose the the oldest expectation to evict */
928 list_for_each_entry_reverse(i, &ip_conntrack_expect_list, list) {
929 if (expect_matches(i, exp) && del_timer(&i->timeout)) {
930 ip_ct_unlink_expect(i);
931 write_unlock_bh(&ip_conntrack_lock);
932 ip_conntrack_expect_put(i);
936 write_unlock_bh(&ip_conntrack_lock);
939 /* We don't increase the master conntrack refcount for non-fulfilled
940 * conntracks. During the conntrack destruction, the expectations are
941 * always killed before the conntrack itself */
942 struct ip_conntrack_expect *ip_conntrack_expect_alloc(struct ip_conntrack *me)
944 struct ip_conntrack_expect *new;
946 new = kmem_cache_alloc(ip_conntrack_expect_cachep, GFP_ATOMIC);
948 DEBUGP("expect_related: OOM allocating expect\n");
952 atomic_set(&new->use, 1);
956 void ip_conntrack_expect_put(struct ip_conntrack_expect *exp)
958 if (atomic_dec_and_test(&exp->use))
959 kmem_cache_free(ip_conntrack_expect_cachep, exp);
962 static void ip_conntrack_expect_insert(struct ip_conntrack_expect *exp)
964 atomic_inc(&exp->use);
965 exp->master->expecting++;
966 list_add(&exp->list, &ip_conntrack_expect_list);
968 init_timer(&exp->timeout);
969 exp->timeout.data = (unsigned long)exp;
970 exp->timeout.function = expectation_timed_out;
971 exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ;
972 add_timer(&exp->timeout);
974 exp->id = ++ip_conntrack_expect_next_id;
975 atomic_inc(&exp->use);
976 CONNTRACK_STAT_INC(expect_create);
979 /* Race with expectations being used means we could have none to find; OK. */
980 static void evict_oldest_expect(struct ip_conntrack *master)
982 struct ip_conntrack_expect *i;
984 list_for_each_entry_reverse(i, &ip_conntrack_expect_list, list) {
985 if (i->master == master) {
986 if (del_timer(&i->timeout)) {
987 ip_ct_unlink_expect(i);
988 ip_conntrack_expect_put(i);
995 static inline int refresh_timer(struct ip_conntrack_expect *i)
997 if (!del_timer(&i->timeout))
1000 i->timeout.expires = jiffies + i->master->helper->timeout*HZ;
1001 add_timer(&i->timeout);
1005 int ip_conntrack_expect_related(struct ip_conntrack_expect *expect)
1007 struct ip_conntrack_expect *i;
1010 DEBUGP("ip_conntrack_expect_related %p\n", related_to);
1011 DEBUGP("tuple: "); DUMP_TUPLE(&expect->tuple);
1012 DEBUGP("mask: "); DUMP_TUPLE(&expect->mask);
1014 write_lock_bh(&ip_conntrack_lock);
1015 list_for_each_entry(i, &ip_conntrack_expect_list, list) {
1016 if (expect_matches(i, expect)) {
1017 /* Refresh timer: if it's dying, ignore.. */
1018 if (refresh_timer(i)) {
1022 } else if (expect_clash(i, expect)) {
1028 /* Will be over limit? */
1029 if (expect->master->helper->max_expected &&
1030 expect->master->expecting >= expect->master->helper->max_expected)
1031 evict_oldest_expect(expect->master);
1033 ip_conntrack_expect_insert(expect);
1034 ip_conntrack_expect_event(IPEXP_NEW, expect);
1037 write_unlock_bh(&ip_conntrack_lock);
1041 /* Alter reply tuple (maybe alter helper). This is for NAT, and is
1042 implicitly racy: see __ip_conntrack_confirm */
1043 void ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
1044 const struct ip_conntrack_tuple *newreply)
1046 write_lock_bh(&ip_conntrack_lock);
1047 /* Should be unconfirmed, so not in hash table yet */
1048 IP_NF_ASSERT(!is_confirmed(conntrack));
1050 DEBUGP("Altering reply tuple of %p to ", conntrack);
1051 DUMP_TUPLE(newreply);
1053 conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1054 if (!conntrack->master && conntrack->expecting == 0)
1055 conntrack->helper = __ip_conntrack_helper_find(newreply);
1056 write_unlock_bh(&ip_conntrack_lock);
1059 int ip_conntrack_helper_register(struct ip_conntrack_helper *me)
1061 BUG_ON(me->timeout == 0);
1062 write_lock_bh(&ip_conntrack_lock);
1063 list_prepend(&helpers, me);
1064 write_unlock_bh(&ip_conntrack_lock);
1069 struct ip_conntrack_helper *
1070 __ip_conntrack_helper_find_byname(const char *name)
1072 struct ip_conntrack_helper *h;
1074 list_for_each_entry(h, &helpers, list) {
1075 if (!strcmp(h->name, name))
1082 static inline int unhelp(struct ip_conntrack_tuple_hash *i,
1083 const struct ip_conntrack_helper *me)
1085 if (tuplehash_to_ctrack(i)->helper == me) {
1086 ip_conntrack_event(IPCT_HELPER, tuplehash_to_ctrack(i));
1087 tuplehash_to_ctrack(i)->helper = NULL;
1092 void ip_conntrack_helper_unregister(struct ip_conntrack_helper *me)
1095 struct ip_conntrack_expect *exp, *tmp;
1097 /* Need write lock here, to delete helper. */
1098 write_lock_bh(&ip_conntrack_lock);
1099 LIST_DELETE(&helpers, me);
1101 /* Get rid of expectations */
1102 list_for_each_entry_safe(exp, tmp, &ip_conntrack_expect_list, list) {
1103 if (exp->master->helper == me && del_timer(&exp->timeout)) {
1104 ip_ct_unlink_expect(exp);
1105 ip_conntrack_expect_put(exp);
1108 /* Get rid of expecteds, set helpers to NULL. */
1109 LIST_FIND_W(&unconfirmed, unhelp, struct ip_conntrack_tuple_hash*, me);
1110 for (i = 0; i < ip_conntrack_htable_size; i++)
1111 LIST_FIND_W(&ip_conntrack_hash[i], unhelp,
1112 struct ip_conntrack_tuple_hash *, me);
1113 write_unlock_bh(&ip_conntrack_lock);
1115 /* Someone could be still looking at the helper in a bh. */
1119 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1120 void __ip_ct_refresh_acct(struct ip_conntrack *ct,
1121 enum ip_conntrack_info ctinfo,
1122 const struct sk_buff *skb,
1123 unsigned long extra_jiffies,
1128 IP_NF_ASSERT(ct->timeout.data == (unsigned long)ct);
1131 write_lock_bh(&ip_conntrack_lock);
1133 /* If not in hash table, timer will not be active yet */
1134 if (!is_confirmed(ct)) {
1135 ct->timeout.expires = extra_jiffies;
1136 event = IPCT_REFRESH;
1138 /* Need del_timer for race avoidance (may already be dying). */
1139 if (del_timer(&ct->timeout)) {
1140 ct->timeout.expires = jiffies + extra_jiffies;
1141 add_timer(&ct->timeout);
1142 event = IPCT_REFRESH;
1146 #ifdef CONFIG_IP_NF_CT_ACCT
1148 ct->counters[CTINFO2DIR(ctinfo)].packets++;
1149 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
1150 ntohs(skb->nh.iph->tot_len);
1151 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
1152 || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
1153 event |= IPCT_COUNTER_FILLING;
1157 write_unlock_bh(&ip_conntrack_lock);
1159 /* must be unlocked when calling event cache */
1161 ip_conntrack_event_cache(event, skb);
1164 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
1165 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
1166 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1167 * in ip_conntrack_core, since we don't want the protocols to autoload
1168 * or depend on ctnetlink */
1169 int ip_ct_port_tuple_to_nfattr(struct sk_buff *skb,
1170 const struct ip_conntrack_tuple *tuple)
1172 NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
1173 &tuple->src.u.tcp.port);
1174 NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
1175 &tuple->dst.u.tcp.port);
1182 int ip_ct_port_nfattr_to_tuple(struct nfattr *tb[],
1183 struct ip_conntrack_tuple *t)
1185 if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
1189 *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
1191 *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
1197 /* Returns new sk_buff, or NULL */
1199 ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user)
1204 skb = ip_defrag(skb, user);
1208 ip_send_check(skb->nh.iph);
1212 /* Used by ipt_REJECT. */
1213 static void ip_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1215 struct ip_conntrack *ct;
1216 enum ip_conntrack_info ctinfo;
1218 /* This ICMP is in reverse direction to the packet which caused it */
1219 ct = ip_conntrack_get(skb, &ctinfo);
1221 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1222 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
1224 ctinfo = IP_CT_RELATED;
1226 /* Attach to new skbuff, and increment count */
1227 nskb->nfct = &ct->ct_general;
1228 nskb->nfctinfo = ctinfo;
1229 nf_conntrack_get(nskb->nfct);
1233 do_iter(const struct ip_conntrack_tuple_hash *i,
1234 int (*iter)(struct ip_conntrack *i, void *data),
1237 return iter(tuplehash_to_ctrack(i), data);
1240 /* Bring out ya dead! */
1241 static struct ip_conntrack_tuple_hash *
1242 get_next_corpse(int (*iter)(struct ip_conntrack *i, void *data),
1243 void *data, unsigned int *bucket)
1245 struct ip_conntrack_tuple_hash *h = NULL;
1247 write_lock_bh(&ip_conntrack_lock);
1248 for (; *bucket < ip_conntrack_htable_size; (*bucket)++) {
1249 h = LIST_FIND_W(&ip_conntrack_hash[*bucket], do_iter,
1250 struct ip_conntrack_tuple_hash *, iter, data);
1255 h = LIST_FIND_W(&unconfirmed, do_iter,
1256 struct ip_conntrack_tuple_hash *, iter, data);
1258 atomic_inc(&tuplehash_to_ctrack(h)->ct_general.use);
1259 write_unlock_bh(&ip_conntrack_lock);
1265 ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *), void *data)
1267 struct ip_conntrack_tuple_hash *h;
1268 unsigned int bucket = 0;
1270 while ((h = get_next_corpse(iter, data, &bucket)) != NULL) {
1271 struct ip_conntrack *ct = tuplehash_to_ctrack(h);
1272 /* Time to push up daises... */
1273 if (del_timer(&ct->timeout))
1274 death_by_timeout((unsigned long)ct);
1275 /* ... else the timer will get him soon. */
1277 ip_conntrack_put(ct);
1281 /* Fast function for those who don't want to parse /proc (and I don't
1283 /* Reversing the socket's dst/src point of view gives us the reply
1286 getorigdst(struct sock *sk, int optval, void __user *user, int *len)
1288 struct inet_sock *inet = inet_sk(sk);
1289 struct ip_conntrack_tuple_hash *h;
1290 struct ip_conntrack_tuple tuple;
1292 IP_CT_TUPLE_U_BLANK(&tuple);
1293 tuple.src.ip = inet->rcv_saddr;
1294 tuple.src.u.tcp.port = inet->sport;
1295 tuple.dst.ip = inet->daddr;
1296 tuple.dst.u.tcp.port = inet->dport;
1297 tuple.dst.protonum = IPPROTO_TCP;
1299 /* We only do TCP at the moment: is there a better way? */
1300 if (strcmp(sk->sk_prot->name, "TCP")) {
1301 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
1302 return -ENOPROTOOPT;
1305 if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
1306 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
1307 *len, sizeof(struct sockaddr_in));
1311 h = ip_conntrack_find_get(&tuple, NULL);
1313 struct sockaddr_in sin;
1314 struct ip_conntrack *ct = tuplehash_to_ctrack(h);
1316 sin.sin_family = AF_INET;
1317 sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
1318 .tuple.dst.u.tcp.port;
1319 sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
1322 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
1323 NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
1324 ip_conntrack_put(ct);
1325 if (copy_to_user(user, &sin, sizeof(sin)) != 0)
1330 DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
1331 NIPQUAD(tuple.src.ip), ntohs(tuple.src.u.tcp.port),
1332 NIPQUAD(tuple.dst.ip), ntohs(tuple.dst.u.tcp.port));
1336 static struct nf_sockopt_ops so_getorigdst = {
1338 .get_optmin = SO_ORIGINAL_DST,
1339 .get_optmax = SO_ORIGINAL_DST+1,
1343 static int kill_all(struct ip_conntrack *i, void *data)
1348 void ip_conntrack_flush(void)
1350 ip_ct_iterate_cleanup(kill_all, NULL);
1353 static void free_conntrack_hash(struct list_head *hash, int vmalloced,int size)
1358 free_pages((unsigned long)hash,
1359 get_order(sizeof(struct list_head) * size));
1362 /* Mishearing the voices in his head, our hero wonders how he's
1363 supposed to kill the mall. */
1364 void ip_conntrack_cleanup(void)
1366 ip_ct_attach = NULL;
1368 /* This makes sure all current packets have passed through
1369 netfilter framework. Roll on, two-stage module
1373 ip_ct_event_cache_flush();
1375 ip_conntrack_flush();
1376 if (atomic_read(&ip_conntrack_count) != 0) {
1378 goto i_see_dead_people;
1380 /* wait until all references to ip_conntrack_untracked are dropped */
1381 while (atomic_read(&ip_conntrack_untracked.ct_general.use) > 1)
1384 kmem_cache_destroy(ip_conntrack_cachep);
1385 kmem_cache_destroy(ip_conntrack_expect_cachep);
1386 free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc,
1387 ip_conntrack_htable_size);
1388 nf_unregister_sockopt(&so_getorigdst);
1391 static struct list_head *alloc_hashtable(int size, int *vmalloced)
1393 struct list_head *hash;
1397 hash = (void*)__get_free_pages(GFP_KERNEL,
1398 get_order(sizeof(struct list_head)
1402 printk(KERN_WARNING"ip_conntrack: falling back to vmalloc.\n");
1403 hash = vmalloc(sizeof(struct list_head) * size);
1407 for (i = 0; i < size; i++)
1408 INIT_LIST_HEAD(&hash[i]);
1413 static int set_hashsize(const char *val, struct kernel_param *kp)
1415 int i, bucket, hashsize, vmalloced;
1416 int old_vmalloced, old_size;
1418 struct list_head *hash, *old_hash;
1419 struct ip_conntrack_tuple_hash *h;
1421 /* On boot, we can set this without any fancy locking. */
1422 if (!ip_conntrack_htable_size)
1423 return param_set_int(val, kp);
1425 hashsize = simple_strtol(val, NULL, 0);
1429 hash = alloc_hashtable(hashsize, &vmalloced);
1433 /* We have to rehash for the new table anyway, so we also can
1434 * use a new random seed */
1435 get_random_bytes(&rnd, 4);
1437 write_lock_bh(&ip_conntrack_lock);
1438 for (i = 0; i < ip_conntrack_htable_size; i++) {
1439 while (!list_empty(&ip_conntrack_hash[i])) {
1440 h = list_entry(ip_conntrack_hash[i].next,
1441 struct ip_conntrack_tuple_hash, list);
1443 bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1444 list_add_tail(&h->list, &hash[bucket]);
1447 old_size = ip_conntrack_htable_size;
1448 old_vmalloced = ip_conntrack_vmalloc;
1449 old_hash = ip_conntrack_hash;
1451 ip_conntrack_htable_size = hashsize;
1452 ip_conntrack_vmalloc = vmalloced;
1453 ip_conntrack_hash = hash;
1454 ip_conntrack_hash_rnd = rnd;
1455 write_unlock_bh(&ip_conntrack_lock);
1457 free_conntrack_hash(old_hash, old_vmalloced, old_size);
1461 module_param_call(hashsize, set_hashsize, param_get_uint,
1462 &ip_conntrack_htable_size, 0600);
1464 int __init ip_conntrack_init(void)
1469 /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
1470 * machine has 256 buckets. >= 1GB machines have 8192 buckets. */
1471 if (!ip_conntrack_htable_size) {
1472 ip_conntrack_htable_size
1473 = (((num_physpages << PAGE_SHIFT) / 16384)
1474 / sizeof(struct list_head));
1475 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1476 ip_conntrack_htable_size = 8192;
1477 if (ip_conntrack_htable_size < 16)
1478 ip_conntrack_htable_size = 16;
1480 ip_conntrack_max = 8 * ip_conntrack_htable_size;
1482 printk("ip_conntrack version %s (%u buckets, %d max)"
1483 " - %Zd bytes per conntrack\n", IP_CONNTRACK_VERSION,
1484 ip_conntrack_htable_size, ip_conntrack_max,
1485 sizeof(struct ip_conntrack));
1487 ret = nf_register_sockopt(&so_getorigdst);
1489 printk(KERN_ERR "Unable to register netfilter socket option\n");
1493 ip_conntrack_hash = alloc_hashtable(ip_conntrack_htable_size,
1494 &ip_conntrack_vmalloc);
1495 if (!ip_conntrack_hash) {
1496 printk(KERN_ERR "Unable to create ip_conntrack_hash\n");
1497 goto err_unreg_sockopt;
1500 ip_conntrack_cachep = kmem_cache_create("ip_conntrack",
1501 sizeof(struct ip_conntrack), 0,
1503 if (!ip_conntrack_cachep) {
1504 printk(KERN_ERR "Unable to create ip_conntrack slab cache\n");
1508 ip_conntrack_expect_cachep = kmem_cache_create("ip_conntrack_expect",
1509 sizeof(struct ip_conntrack_expect),
1511 if (!ip_conntrack_expect_cachep) {
1512 printk(KERN_ERR "Unable to create ip_expect slab cache\n");
1513 goto err_free_conntrack_slab;
1516 /* Don't NEED lock here, but good form anyway. */
1517 write_lock_bh(&ip_conntrack_lock);
1518 for (i = 0; i < MAX_IP_CT_PROTO; i++)
1519 ip_ct_protos[i] = &ip_conntrack_generic_protocol;
1520 /* Sew in builtin protocols. */
1521 ip_ct_protos[IPPROTO_TCP] = &ip_conntrack_protocol_tcp;
1522 ip_ct_protos[IPPROTO_UDP] = &ip_conntrack_protocol_udp;
1523 ip_ct_protos[IPPROTO_ICMP] = &ip_conntrack_protocol_icmp;
1524 write_unlock_bh(&ip_conntrack_lock);
1526 /* For use by ipt_REJECT */
1527 ip_ct_attach = ip_conntrack_attach;
1529 /* Set up fake conntrack:
1530 - to never be deleted, not in any hashes */
1531 atomic_set(&ip_conntrack_untracked.ct_general.use, 1);
1532 /* - and look it like as a confirmed connection */
1533 set_bit(IPS_CONFIRMED_BIT, &ip_conntrack_untracked.status);
1537 err_free_conntrack_slab:
1538 kmem_cache_destroy(ip_conntrack_cachep);
1540 free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc,
1541 ip_conntrack_htable_size);
1543 nf_unregister_sockopt(&so_getorigdst);