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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6
[linux-2.6.git] / net / netfilter / nf_conntrack_core.c
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
3    extension. */
4
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  *
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.
12  */
13
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/proc_fs.h>
19 #include <linux/vmalloc.h>
20 #include <linux/stddef.h>
21 #include <linux/slab.h>
22 #include <linux/random.h>
23 #include <linux/jhash.h>
24 #include <linux/err.h>
25 #include <linux/percpu.h>
26 #include <linux/moduleparam.h>
27 #include <linux/notifier.h>
28 #include <linux/kernel.h>
29 #include <linux/netdevice.h>
30 #include <linux/socket.h>
31 #include <linux/mm.h>
32 #include <linux/rculist_nulls.h>
33
34 #include <net/netfilter/nf_conntrack.h>
35 #include <net/netfilter/nf_conntrack_l3proto.h>
36 #include <net/netfilter/nf_conntrack_l4proto.h>
37 #include <net/netfilter/nf_conntrack_expect.h>
38 #include <net/netfilter/nf_conntrack_helper.h>
39 #include <net/netfilter/nf_conntrack_core.h>
40 #include <net/netfilter/nf_conntrack_extend.h>
41 #include <net/netfilter/nf_conntrack_acct.h>
42 #include <net/netfilter/nf_nat.h>
43 #include <net/netfilter/nf_nat_core.h>
44
45 #define NF_CONNTRACK_VERSION    "0.5.0"
46
47 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
48                                       enum nf_nat_manip_type manip,
49                                       struct nlattr *attr) __read_mostly;
50 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
51
52 DEFINE_SPINLOCK(nf_conntrack_lock);
53 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
54
55 unsigned int nf_conntrack_htable_size __read_mostly;
56 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
57
58 unsigned int nf_conntrack_max __read_mostly;
59 EXPORT_SYMBOL_GPL(nf_conntrack_max);
60
61 struct nf_conn nf_conntrack_untracked __read_mostly;
62 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
63
64 static struct kmem_cache *nf_conntrack_cachep __read_mostly;
65
66 static int nf_conntrack_hash_rnd_initted;
67 static unsigned int nf_conntrack_hash_rnd;
68
69 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
70                                   unsigned int size, unsigned int rnd)
71 {
72         unsigned int n;
73         u_int32_t h;
74
75         /* The direction must be ignored, so we hash everything up to the
76          * destination ports (which is a multiple of 4) and treat the last
77          * three bytes manually.
78          */
79         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
80         h = jhash2((u32 *)tuple, n,
81                    rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
82                           tuple->dst.protonum));
83
84         return ((u64)h * size) >> 32;
85 }
86
87 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
88 {
89         return __hash_conntrack(tuple, nf_conntrack_htable_size,
90                                 nf_conntrack_hash_rnd);
91 }
92
93 bool
94 nf_ct_get_tuple(const struct sk_buff *skb,
95                 unsigned int nhoff,
96                 unsigned int dataoff,
97                 u_int16_t l3num,
98                 u_int8_t protonum,
99                 struct nf_conntrack_tuple *tuple,
100                 const struct nf_conntrack_l3proto *l3proto,
101                 const struct nf_conntrack_l4proto *l4proto)
102 {
103         memset(tuple, 0, sizeof(*tuple));
104
105         tuple->src.l3num = l3num;
106         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
107                 return false;
108
109         tuple->dst.protonum = protonum;
110         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
111
112         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
113 }
114 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
115
116 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
117                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
118 {
119         struct nf_conntrack_l3proto *l3proto;
120         struct nf_conntrack_l4proto *l4proto;
121         unsigned int protoff;
122         u_int8_t protonum;
123         int ret;
124
125         rcu_read_lock();
126
127         l3proto = __nf_ct_l3proto_find(l3num);
128         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
129         if (ret != NF_ACCEPT) {
130                 rcu_read_unlock();
131                 return false;
132         }
133
134         l4proto = __nf_ct_l4proto_find(l3num, protonum);
135
136         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
137                               l3proto, l4proto);
138
139         rcu_read_unlock();
140         return ret;
141 }
142 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
143
144 bool
145 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
146                    const struct nf_conntrack_tuple *orig,
147                    const struct nf_conntrack_l3proto *l3proto,
148                    const struct nf_conntrack_l4proto *l4proto)
149 {
150         memset(inverse, 0, sizeof(*inverse));
151
152         inverse->src.l3num = orig->src.l3num;
153         if (l3proto->invert_tuple(inverse, orig) == 0)
154                 return false;
155
156         inverse->dst.dir = !orig->dst.dir;
157
158         inverse->dst.protonum = orig->dst.protonum;
159         return l4proto->invert_tuple(inverse, orig);
160 }
161 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
162
163 static void
164 clean_from_lists(struct nf_conn *ct)
165 {
166         pr_debug("clean_from_lists(%p)\n", ct);
167         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
168         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
169
170         /* Destroy all pending expectations */
171         nf_ct_remove_expectations(ct);
172 }
173
174 static void
175 destroy_conntrack(struct nf_conntrack *nfct)
176 {
177         struct nf_conn *ct = (struct nf_conn *)nfct;
178         struct net *net = nf_ct_net(ct);
179         struct nf_conntrack_l4proto *l4proto;
180
181         pr_debug("destroy_conntrack(%p)\n", ct);
182         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
183         NF_CT_ASSERT(!timer_pending(&ct->timeout));
184
185         if (!test_bit(IPS_DYING_BIT, &ct->status))
186                 nf_conntrack_event(IPCT_DESTROY, ct);
187         set_bit(IPS_DYING_BIT, &ct->status);
188
189         /* To make sure we don't get any weird locking issues here:
190          * destroy_conntrack() MUST NOT be called with a write lock
191          * to nf_conntrack_lock!!! -HW */
192         rcu_read_lock();
193         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
194         if (l4proto && l4proto->destroy)
195                 l4proto->destroy(ct);
196
197         rcu_read_unlock();
198
199         spin_lock_bh(&nf_conntrack_lock);
200         /* Expectations will have been removed in clean_from_lists,
201          * except TFTP can create an expectation on the first packet,
202          * before connection is in the list, so we need to clean here,
203          * too. */
204         nf_ct_remove_expectations(ct);
205
206         /* We overload first tuple to link into unconfirmed list. */
207         if (!nf_ct_is_confirmed(ct)) {
208                 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
209                 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
210         }
211
212         NF_CT_STAT_INC(net, delete);
213         spin_unlock_bh(&nf_conntrack_lock);
214
215         if (ct->master)
216                 nf_ct_put(ct->master);
217
218         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
219         nf_conntrack_free(ct);
220 }
221
222 static void death_by_timeout(unsigned long ul_conntrack)
223 {
224         struct nf_conn *ct = (void *)ul_conntrack;
225         struct net *net = nf_ct_net(ct);
226         struct nf_conn_help *help = nfct_help(ct);
227         struct nf_conntrack_helper *helper;
228
229         if (help) {
230                 rcu_read_lock();
231                 helper = rcu_dereference(help->helper);
232                 if (helper && helper->destroy)
233                         helper->destroy(ct);
234                 rcu_read_unlock();
235         }
236
237         spin_lock_bh(&nf_conntrack_lock);
238         /* Inside lock so preempt is disabled on module removal path.
239          * Otherwise we can get spurious warnings. */
240         NF_CT_STAT_INC(net, delete_list);
241         clean_from_lists(ct);
242         spin_unlock_bh(&nf_conntrack_lock);
243         nf_ct_put(ct);
244 }
245
246 /*
247  * Warning :
248  * - Caller must take a reference on returned object
249  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
250  * OR
251  * - Caller must lock nf_conntrack_lock before calling this function
252  */
253 struct nf_conntrack_tuple_hash *
254 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
255 {
256         struct nf_conntrack_tuple_hash *h;
257         struct hlist_nulls_node *n;
258         unsigned int hash = hash_conntrack(tuple);
259
260         /* Disable BHs the entire time since we normally need to disable them
261          * at least once for the stats anyway.
262          */
263         local_bh_disable();
264 begin:
265         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
266                 if (nf_ct_tuple_equal(tuple, &h->tuple)) {
267                         NF_CT_STAT_INC(net, found);
268                         local_bh_enable();
269                         return h;
270                 }
271                 NF_CT_STAT_INC(net, searched);
272         }
273         /*
274          * if the nulls value we got at the end of this lookup is
275          * not the expected one, we must restart lookup.
276          * We probably met an item that was moved to another chain.
277          */
278         if (get_nulls_value(n) != hash)
279                 goto begin;
280         local_bh_enable();
281
282         return NULL;
283 }
284 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
285
286 /* Find a connection corresponding to a tuple. */
287 struct nf_conntrack_tuple_hash *
288 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
289 {
290         struct nf_conntrack_tuple_hash *h;
291         struct nf_conn *ct;
292
293         rcu_read_lock();
294 begin:
295         h = __nf_conntrack_find(net, tuple);
296         if (h) {
297                 ct = nf_ct_tuplehash_to_ctrack(h);
298                 if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
299                         h = NULL;
300                 else {
301                         if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple))) {
302                                 nf_ct_put(ct);
303                                 goto begin;
304                         }
305                 }
306         }
307         rcu_read_unlock();
308
309         return h;
310 }
311 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
312
313 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
314                                        unsigned int hash,
315                                        unsigned int repl_hash)
316 {
317         struct net *net = nf_ct_net(ct);
318
319         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
320                            &net->ct.hash[hash]);
321         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
322                            &net->ct.hash[repl_hash]);
323 }
324
325 void nf_conntrack_hash_insert(struct nf_conn *ct)
326 {
327         unsigned int hash, repl_hash;
328
329         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
330         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
331
332         __nf_conntrack_hash_insert(ct, hash, repl_hash);
333 }
334 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
335
336 /* Confirm a connection given skb; places it in hash table */
337 int
338 __nf_conntrack_confirm(struct sk_buff *skb)
339 {
340         unsigned int hash, repl_hash;
341         struct nf_conntrack_tuple_hash *h;
342         struct nf_conn *ct;
343         struct nf_conn_help *help;
344         struct hlist_nulls_node *n;
345         enum ip_conntrack_info ctinfo;
346         struct net *net;
347
348         ct = nf_ct_get(skb, &ctinfo);
349         net = nf_ct_net(ct);
350
351         /* ipt_REJECT uses nf_conntrack_attach to attach related
352            ICMP/TCP RST packets in other direction.  Actual packet
353            which created connection will be IP_CT_NEW or for an
354            expected connection, IP_CT_RELATED. */
355         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
356                 return NF_ACCEPT;
357
358         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
359         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
360
361         /* We're not in hash table, and we refuse to set up related
362            connections for unconfirmed conns.  But packet copies and
363            REJECT will give spurious warnings here. */
364         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
365
366         /* No external references means noone else could have
367            confirmed us. */
368         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
369         pr_debug("Confirming conntrack %p\n", ct);
370
371         spin_lock_bh(&nf_conntrack_lock);
372
373         /* See if there's one in the list already, including reverse:
374            NAT could have grabbed it without realizing, since we're
375            not in the hash.  If there is, we lost race. */
376         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
377                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
378                                       &h->tuple))
379                         goto out;
380         hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
381                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
382                                       &h->tuple))
383                         goto out;
384
385         /* Remove from unconfirmed list */
386         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
387
388         __nf_conntrack_hash_insert(ct, hash, repl_hash);
389         /* Timer relative to confirmation time, not original
390            setting time, otherwise we'd get timer wrap in
391            weird delay cases. */
392         ct->timeout.expires += jiffies;
393         add_timer(&ct->timeout);
394         atomic_inc(&ct->ct_general.use);
395         set_bit(IPS_CONFIRMED_BIT, &ct->status);
396         NF_CT_STAT_INC(net, insert);
397         spin_unlock_bh(&nf_conntrack_lock);
398         help = nfct_help(ct);
399         if (help && help->helper)
400                 nf_conntrack_event_cache(IPCT_HELPER, ct);
401 #ifdef CONFIG_NF_NAT_NEEDED
402         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
403             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
404                 nf_conntrack_event_cache(IPCT_NATINFO, ct);
405 #endif
406         nf_conntrack_event_cache(master_ct(ct) ?
407                                  IPCT_RELATED : IPCT_NEW, ct);
408         return NF_ACCEPT;
409
410 out:
411         NF_CT_STAT_INC(net, insert_failed);
412         spin_unlock_bh(&nf_conntrack_lock);
413         return NF_DROP;
414 }
415 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
416
417 /* Returns true if a connection correspondings to the tuple (required
418    for NAT). */
419 int
420 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
421                          const struct nf_conn *ignored_conntrack)
422 {
423         struct net *net = nf_ct_net(ignored_conntrack);
424         struct nf_conntrack_tuple_hash *h;
425         struct hlist_nulls_node *n;
426         unsigned int hash = hash_conntrack(tuple);
427
428         /* Disable BHs the entire time since we need to disable them at
429          * least once for the stats anyway.
430          */
431         rcu_read_lock_bh();
432         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
433                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
434                     nf_ct_tuple_equal(tuple, &h->tuple)) {
435                         NF_CT_STAT_INC(net, found);
436                         rcu_read_unlock_bh();
437                         return 1;
438                 }
439                 NF_CT_STAT_INC(net, searched);
440         }
441         rcu_read_unlock_bh();
442
443         return 0;
444 }
445 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
446
447 #define NF_CT_EVICTION_RANGE    8
448
449 /* There's a small race here where we may free a just-assured
450    connection.  Too bad: we're in trouble anyway. */
451 static noinline int early_drop(struct net *net, unsigned int hash)
452 {
453         /* Use oldest entry, which is roughly LRU */
454         struct nf_conntrack_tuple_hash *h;
455         struct nf_conn *ct = NULL, *tmp;
456         struct hlist_nulls_node *n;
457         unsigned int i, cnt = 0;
458         int dropped = 0;
459
460         rcu_read_lock();
461         for (i = 0; i < nf_conntrack_htable_size; i++) {
462                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
463                                          hnnode) {
464                         tmp = nf_ct_tuplehash_to_ctrack(h);
465                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
466                                 ct = tmp;
467                         cnt++;
468                 }
469
470                 if (ct && unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
471                         ct = NULL;
472                 if (ct || cnt >= NF_CT_EVICTION_RANGE)
473                         break;
474                 hash = (hash + 1) % nf_conntrack_htable_size;
475         }
476         rcu_read_unlock();
477
478         if (!ct)
479                 return dropped;
480
481         if (del_timer(&ct->timeout)) {
482                 death_by_timeout((unsigned long)ct);
483                 dropped = 1;
484                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
485         }
486         nf_ct_put(ct);
487         return dropped;
488 }
489
490 struct nf_conn *nf_conntrack_alloc(struct net *net,
491                                    const struct nf_conntrack_tuple *orig,
492                                    const struct nf_conntrack_tuple *repl,
493                                    gfp_t gfp)
494 {
495         struct nf_conn *ct;
496
497         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
498                 get_random_bytes(&nf_conntrack_hash_rnd,
499                                 sizeof(nf_conntrack_hash_rnd));
500                 nf_conntrack_hash_rnd_initted = 1;
501         }
502
503         /* We don't want any race condition at early drop stage */
504         atomic_inc(&net->ct.count);
505
506         if (nf_conntrack_max &&
507             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
508                 unsigned int hash = hash_conntrack(orig);
509                 if (!early_drop(net, hash)) {
510                         atomic_dec(&net->ct.count);
511                         if (net_ratelimit())
512                                 printk(KERN_WARNING
513                                        "nf_conntrack: table full, dropping"
514                                        " packet.\n");
515                         return ERR_PTR(-ENOMEM);
516                 }
517         }
518
519         ct = kmem_cache_zalloc(nf_conntrack_cachep, gfp);
520         if (ct == NULL) {
521                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
522                 atomic_dec(&net->ct.count);
523                 return ERR_PTR(-ENOMEM);
524         }
525
526         atomic_set(&ct->ct_general.use, 1);
527         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
528         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
529         /* Don't set timer yet: wait for confirmation */
530         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
531 #ifdef CONFIG_NET_NS
532         ct->ct_net = net;
533 #endif
534
535         return ct;
536 }
537 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
538
539 void nf_conntrack_free(struct nf_conn *ct)
540 {
541         struct net *net = nf_ct_net(ct);
542
543         nf_ct_ext_destroy(ct);
544         atomic_dec(&net->ct.count);
545         nf_ct_ext_free(ct);
546         kmem_cache_free(nf_conntrack_cachep, ct);
547 }
548 EXPORT_SYMBOL_GPL(nf_conntrack_free);
549
550 /* Allocate a new conntrack: we return -ENOMEM if classification
551    failed due to stress.  Otherwise it really is unclassifiable. */
552 static struct nf_conntrack_tuple_hash *
553 init_conntrack(struct net *net,
554                const struct nf_conntrack_tuple *tuple,
555                struct nf_conntrack_l3proto *l3proto,
556                struct nf_conntrack_l4proto *l4proto,
557                struct sk_buff *skb,
558                unsigned int dataoff)
559 {
560         struct nf_conn *ct;
561         struct nf_conn_help *help;
562         struct nf_conntrack_tuple repl_tuple;
563         struct nf_conntrack_expect *exp;
564
565         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
566                 pr_debug("Can't invert tuple.\n");
567                 return NULL;
568         }
569
570         ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
571         if (IS_ERR(ct)) {
572                 pr_debug("Can't allocate conntrack.\n");
573                 return (struct nf_conntrack_tuple_hash *)ct;
574         }
575
576         if (!l4proto->new(ct, skb, dataoff)) {
577                 nf_conntrack_free(ct);
578                 pr_debug("init conntrack: can't track with proto module\n");
579                 return NULL;
580         }
581
582         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
583
584         spin_lock_bh(&nf_conntrack_lock);
585         exp = nf_ct_find_expectation(net, tuple);
586         if (exp) {
587                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
588                          ct, exp);
589                 /* Welcome, Mr. Bond.  We've been expecting you... */
590                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
591                 ct->master = exp->master;
592                 if (exp->helper) {
593                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
594                         if (help)
595                                 rcu_assign_pointer(help->helper, exp->helper);
596                 }
597
598 #ifdef CONFIG_NF_CONNTRACK_MARK
599                 ct->mark = exp->master->mark;
600 #endif
601 #ifdef CONFIG_NF_CONNTRACK_SECMARK
602                 ct->secmark = exp->master->secmark;
603 #endif
604                 nf_conntrack_get(&ct->master->ct_general);
605                 NF_CT_STAT_INC(net, expect_new);
606         } else {
607                 __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
608                 NF_CT_STAT_INC(net, new);
609         }
610
611         /* Overload tuple linked list to put us in unconfirmed list. */
612         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
613                        &net->ct.unconfirmed);
614
615         spin_unlock_bh(&nf_conntrack_lock);
616
617         if (exp) {
618                 if (exp->expectfn)
619                         exp->expectfn(ct, exp);
620                 nf_ct_expect_put(exp);
621         }
622
623         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
624 }
625
626 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
627 static inline struct nf_conn *
628 resolve_normal_ct(struct net *net,
629                   struct sk_buff *skb,
630                   unsigned int dataoff,
631                   u_int16_t l3num,
632                   u_int8_t protonum,
633                   struct nf_conntrack_l3proto *l3proto,
634                   struct nf_conntrack_l4proto *l4proto,
635                   int *set_reply,
636                   enum ip_conntrack_info *ctinfo)
637 {
638         struct nf_conntrack_tuple tuple;
639         struct nf_conntrack_tuple_hash *h;
640         struct nf_conn *ct;
641
642         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
643                              dataoff, l3num, protonum, &tuple, l3proto,
644                              l4proto)) {
645                 pr_debug("resolve_normal_ct: Can't get tuple\n");
646                 return NULL;
647         }
648
649         /* look for tuple match */
650         h = nf_conntrack_find_get(net, &tuple);
651         if (!h) {
652                 h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
653                 if (!h)
654                         return NULL;
655                 if (IS_ERR(h))
656                         return (void *)h;
657         }
658         ct = nf_ct_tuplehash_to_ctrack(h);
659
660         /* It exists; we have (non-exclusive) reference. */
661         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
662                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
663                 /* Please set reply bit if this packet OK */
664                 *set_reply = 1;
665         } else {
666                 /* Once we've had two way comms, always ESTABLISHED. */
667                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
668                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
669                         *ctinfo = IP_CT_ESTABLISHED;
670                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
671                         pr_debug("nf_conntrack_in: related packet for %p\n",
672                                  ct);
673                         *ctinfo = IP_CT_RELATED;
674                 } else {
675                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
676                         *ctinfo = IP_CT_NEW;
677                 }
678                 *set_reply = 0;
679         }
680         skb->nfct = &ct->ct_general;
681         skb->nfctinfo = *ctinfo;
682         return ct;
683 }
684
685 unsigned int
686 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
687                 struct sk_buff *skb)
688 {
689         struct nf_conn *ct;
690         enum ip_conntrack_info ctinfo;
691         struct nf_conntrack_l3proto *l3proto;
692         struct nf_conntrack_l4proto *l4proto;
693         unsigned int dataoff;
694         u_int8_t protonum;
695         int set_reply = 0;
696         int ret;
697
698         /* Previously seen (loopback or untracked)?  Ignore. */
699         if (skb->nfct) {
700                 NF_CT_STAT_INC_ATOMIC(net, ignore);
701                 return NF_ACCEPT;
702         }
703
704         /* rcu_read_lock()ed by nf_hook_slow */
705         l3proto = __nf_ct_l3proto_find(pf);
706         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
707                                    &dataoff, &protonum);
708         if (ret <= 0) {
709                 pr_debug("not prepared to track yet or error occured\n");
710                 NF_CT_STAT_INC_ATOMIC(net, error);
711                 NF_CT_STAT_INC_ATOMIC(net, invalid);
712                 return -ret;
713         }
714
715         l4proto = __nf_ct_l4proto_find(pf, protonum);
716
717         /* It may be an special packet, error, unclean...
718          * inverse of the return code tells to the netfilter
719          * core what to do with the packet. */
720         if (l4proto->error != NULL) {
721                 ret = l4proto->error(net, skb, dataoff, &ctinfo, pf, hooknum);
722                 if (ret <= 0) {
723                         NF_CT_STAT_INC_ATOMIC(net, error);
724                         NF_CT_STAT_INC_ATOMIC(net, invalid);
725                         return -ret;
726                 }
727         }
728
729         ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
730                                l3proto, l4proto, &set_reply, &ctinfo);
731         if (!ct) {
732                 /* Not valid part of a connection */
733                 NF_CT_STAT_INC_ATOMIC(net, invalid);
734                 return NF_ACCEPT;
735         }
736
737         if (IS_ERR(ct)) {
738                 /* Too stressed to deal. */
739                 NF_CT_STAT_INC_ATOMIC(net, drop);
740                 return NF_DROP;
741         }
742
743         NF_CT_ASSERT(skb->nfct);
744
745         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
746         if (ret <= 0) {
747                 /* Invalid: inverse of the return code tells
748                  * the netfilter core what to do */
749                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
750                 nf_conntrack_put(skb->nfct);
751                 skb->nfct = NULL;
752                 NF_CT_STAT_INC_ATOMIC(net, invalid);
753                 if (ret == -NF_DROP)
754                         NF_CT_STAT_INC_ATOMIC(net, drop);
755                 return -ret;
756         }
757
758         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
759                 nf_conntrack_event_cache(IPCT_STATUS, ct);
760
761         return ret;
762 }
763 EXPORT_SYMBOL_GPL(nf_conntrack_in);
764
765 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
766                           const struct nf_conntrack_tuple *orig)
767 {
768         bool ret;
769
770         rcu_read_lock();
771         ret = nf_ct_invert_tuple(inverse, orig,
772                                  __nf_ct_l3proto_find(orig->src.l3num),
773                                  __nf_ct_l4proto_find(orig->src.l3num,
774                                                       orig->dst.protonum));
775         rcu_read_unlock();
776         return ret;
777 }
778 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
779
780 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
781    implicitly racy: see __nf_conntrack_confirm */
782 void nf_conntrack_alter_reply(struct nf_conn *ct,
783                               const struct nf_conntrack_tuple *newreply)
784 {
785         struct nf_conn_help *help = nfct_help(ct);
786
787         /* Should be unconfirmed, so not in hash table yet */
788         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
789
790         pr_debug("Altering reply tuple of %p to ", ct);
791         nf_ct_dump_tuple(newreply);
792
793         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
794         if (ct->master || (help && !hlist_empty(&help->expectations)))
795                 return;
796
797         rcu_read_lock();
798         __nf_ct_try_assign_helper(ct, GFP_ATOMIC);
799         rcu_read_unlock();
800 }
801 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
802
803 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
804 void __nf_ct_refresh_acct(struct nf_conn *ct,
805                           enum ip_conntrack_info ctinfo,
806                           const struct sk_buff *skb,
807                           unsigned long extra_jiffies,
808                           int do_acct)
809 {
810         int event = 0;
811
812         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
813         NF_CT_ASSERT(skb);
814
815         spin_lock_bh(&nf_conntrack_lock);
816
817         /* Only update if this is not a fixed timeout */
818         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
819                 goto acct;
820
821         /* If not in hash table, timer will not be active yet */
822         if (!nf_ct_is_confirmed(ct)) {
823                 ct->timeout.expires = extra_jiffies;
824                 event = IPCT_REFRESH;
825         } else {
826                 unsigned long newtime = jiffies + extra_jiffies;
827
828                 /* Only update the timeout if the new timeout is at least
829                    HZ jiffies from the old timeout. Need del_timer for race
830                    avoidance (may already be dying). */
831                 if (newtime - ct->timeout.expires >= HZ
832                     && del_timer(&ct->timeout)) {
833                         ct->timeout.expires = newtime;
834                         add_timer(&ct->timeout);
835                         event = IPCT_REFRESH;
836                 }
837         }
838
839 acct:
840         if (do_acct) {
841                 struct nf_conn_counter *acct;
842
843                 acct = nf_conn_acct_find(ct);
844                 if (acct) {
845                         acct[CTINFO2DIR(ctinfo)].packets++;
846                         acct[CTINFO2DIR(ctinfo)].bytes +=
847                                 skb->len - skb_network_offset(skb);
848                 }
849         }
850
851         spin_unlock_bh(&nf_conntrack_lock);
852
853         /* must be unlocked when calling event cache */
854         if (event)
855                 nf_conntrack_event_cache(event, ct);
856 }
857 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
858
859 bool __nf_ct_kill_acct(struct nf_conn *ct,
860                        enum ip_conntrack_info ctinfo,
861                        const struct sk_buff *skb,
862                        int do_acct)
863 {
864         if (do_acct) {
865                 struct nf_conn_counter *acct;
866
867                 spin_lock_bh(&nf_conntrack_lock);
868                 acct = nf_conn_acct_find(ct);
869                 if (acct) {
870                         acct[CTINFO2DIR(ctinfo)].packets++;
871                         acct[CTINFO2DIR(ctinfo)].bytes +=
872                                 skb->len - skb_network_offset(skb);
873                 }
874                 spin_unlock_bh(&nf_conntrack_lock);
875         }
876
877         if (del_timer(&ct->timeout)) {
878                 ct->timeout.function((unsigned long)ct);
879                 return true;
880         }
881         return false;
882 }
883 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
884
885 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
886
887 #include <linux/netfilter/nfnetlink.h>
888 #include <linux/netfilter/nfnetlink_conntrack.h>
889 #include <linux/mutex.h>
890
891 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
892  * in ip_conntrack_core, since we don't want the protocols to autoload
893  * or depend on ctnetlink */
894 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
895                                const struct nf_conntrack_tuple *tuple)
896 {
897         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
898         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
899         return 0;
900
901 nla_put_failure:
902         return -1;
903 }
904 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
905
906 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
907         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
908         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
909 };
910 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
911
912 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
913                                struct nf_conntrack_tuple *t)
914 {
915         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
916                 return -EINVAL;
917
918         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
919         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
920
921         return 0;
922 }
923 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
924
925 int nf_ct_port_nlattr_tuple_size(void)
926 {
927         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
928 }
929 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
930 #endif
931
932 /* Used by ipt_REJECT and ip6t_REJECT. */
933 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
934 {
935         struct nf_conn *ct;
936         enum ip_conntrack_info ctinfo;
937
938         /* This ICMP is in reverse direction to the packet which caused it */
939         ct = nf_ct_get(skb, &ctinfo);
940         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
941                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
942         else
943                 ctinfo = IP_CT_RELATED;
944
945         /* Attach to new skbuff, and increment count */
946         nskb->nfct = &ct->ct_general;
947         nskb->nfctinfo = ctinfo;
948         nf_conntrack_get(nskb->nfct);
949 }
950
951 /* Bring out ya dead! */
952 static struct nf_conn *
953 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
954                 void *data, unsigned int *bucket)
955 {
956         struct nf_conntrack_tuple_hash *h;
957         struct nf_conn *ct;
958         struct hlist_nulls_node *n;
959
960         spin_lock_bh(&nf_conntrack_lock);
961         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
962                 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
963                         ct = nf_ct_tuplehash_to_ctrack(h);
964                         if (iter(ct, data))
965                                 goto found;
966                 }
967         }
968         hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
969                 ct = nf_ct_tuplehash_to_ctrack(h);
970                 if (iter(ct, data))
971                         set_bit(IPS_DYING_BIT, &ct->status);
972         }
973         spin_unlock_bh(&nf_conntrack_lock);
974         return NULL;
975 found:
976         atomic_inc(&ct->ct_general.use);
977         spin_unlock_bh(&nf_conntrack_lock);
978         return ct;
979 }
980
981 void nf_ct_iterate_cleanup(struct net *net,
982                            int (*iter)(struct nf_conn *i, void *data),
983                            void *data)
984 {
985         struct nf_conn *ct;
986         unsigned int bucket = 0;
987
988         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
989                 /* Time to push up daises... */
990                 if (del_timer(&ct->timeout))
991                         death_by_timeout((unsigned long)ct);
992                 /* ... else the timer will get him soon. */
993
994                 nf_ct_put(ct);
995         }
996 }
997 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
998
999 struct __nf_ct_flush_report {
1000         u32 pid;
1001         int report;
1002 };
1003
1004 static int kill_all(struct nf_conn *i, void *data)
1005 {
1006         struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1007
1008         /* get_next_corpse sets the dying bit for us */
1009         nf_conntrack_event_report(IPCT_DESTROY,
1010                                   i,
1011                                   fr->pid,
1012                                   fr->report);
1013         return 1;
1014 }
1015
1016 void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size)
1017 {
1018         if (vmalloced)
1019                 vfree(hash);
1020         else
1021                 free_pages((unsigned long)hash,
1022                            get_order(sizeof(struct hlist_head) * size));
1023 }
1024 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1025
1026 void nf_conntrack_flush(struct net *net, u32 pid, int report)
1027 {
1028         struct __nf_ct_flush_report fr = {
1029                 .pid    = pid,
1030                 .report = report,
1031         };
1032         nf_ct_iterate_cleanup(net, kill_all, &fr);
1033 }
1034 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1035
1036 static void nf_conntrack_cleanup_init_net(void)
1037 {
1038         nf_conntrack_helper_fini();
1039         nf_conntrack_proto_fini();
1040         kmem_cache_destroy(nf_conntrack_cachep);
1041 }
1042
1043 static void nf_conntrack_cleanup_net(struct net *net)
1044 {
1045         nf_ct_event_cache_flush(net);
1046         nf_conntrack_ecache_fini(net);
1047  i_see_dead_people:
1048         nf_conntrack_flush(net, 0, 0);
1049         if (atomic_read(&net->ct.count) != 0) {
1050                 schedule();
1051                 goto i_see_dead_people;
1052         }
1053         /* wait until all references to nf_conntrack_untracked are dropped */
1054         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1055                 schedule();
1056
1057         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1058                              nf_conntrack_htable_size);
1059         nf_conntrack_acct_fini(net);
1060         nf_conntrack_expect_fini(net);
1061         free_percpu(net->ct.stat);
1062 }
1063
1064 /* Mishearing the voices in his head, our hero wonders how he's
1065    supposed to kill the mall. */
1066 void nf_conntrack_cleanup(struct net *net)
1067 {
1068         if (net_eq(net, &init_net))
1069                 rcu_assign_pointer(ip_ct_attach, NULL);
1070
1071         /* This makes sure all current packets have passed through
1072            netfilter framework.  Roll on, two-stage module
1073            delete... */
1074         synchronize_net();
1075
1076         nf_conntrack_cleanup_net(net);
1077
1078         if (net_eq(net, &init_net)) {
1079                 rcu_assign_pointer(nf_ct_destroy, NULL);
1080                 nf_conntrack_cleanup_init_net();
1081         }
1082 }
1083
1084 void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls)
1085 {
1086         struct hlist_nulls_head *hash;
1087         unsigned int nr_slots, i;
1088         size_t sz;
1089
1090         *vmalloced = 0;
1091
1092         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1093         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1094         sz = nr_slots * sizeof(struct hlist_nulls_head);
1095         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1096                                         get_order(sz));
1097         if (!hash) {
1098                 *vmalloced = 1;
1099                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1100                 hash = __vmalloc(sz, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
1101         }
1102
1103         if (hash && nulls)
1104                 for (i = 0; i < nr_slots; i++)
1105                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1106
1107         return hash;
1108 }
1109 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1110
1111 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1112 {
1113         int i, bucket, vmalloced, old_vmalloced;
1114         unsigned int hashsize, old_size;
1115         int rnd;
1116         struct hlist_nulls_head *hash, *old_hash;
1117         struct nf_conntrack_tuple_hash *h;
1118
1119         /* On boot, we can set this without any fancy locking. */
1120         if (!nf_conntrack_htable_size)
1121                 return param_set_uint(val, kp);
1122
1123         hashsize = simple_strtoul(val, NULL, 0);
1124         if (!hashsize)
1125                 return -EINVAL;
1126
1127         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced, 1);
1128         if (!hash)
1129                 return -ENOMEM;
1130
1131         /* We have to rehahs for the new table anyway, so we also can
1132          * use a newrandom seed */
1133         get_random_bytes(&rnd, sizeof(rnd));
1134
1135         /* Lookups in the old hash might happen in parallel, which means we
1136          * might get false negatives during connection lookup. New connections
1137          * created because of a false negative won't make it into the hash
1138          * though since that required taking the lock.
1139          */
1140         spin_lock_bh(&nf_conntrack_lock);
1141         for (i = 0; i < nf_conntrack_htable_size; i++) {
1142                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1143                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1144                                         struct nf_conntrack_tuple_hash, hnnode);
1145                         hlist_nulls_del_rcu(&h->hnnode);
1146                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1147                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1148                 }
1149         }
1150         old_size = nf_conntrack_htable_size;
1151         old_vmalloced = init_net.ct.hash_vmalloc;
1152         old_hash = init_net.ct.hash;
1153
1154         nf_conntrack_htable_size = hashsize;
1155         init_net.ct.hash_vmalloc = vmalloced;
1156         init_net.ct.hash = hash;
1157         nf_conntrack_hash_rnd = rnd;
1158         spin_unlock_bh(&nf_conntrack_lock);
1159
1160         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1161         return 0;
1162 }
1163 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1164
1165 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1166                   &nf_conntrack_htable_size, 0600);
1167
1168 static int nf_conntrack_init_init_net(void)
1169 {
1170         int max_factor = 8;
1171         int ret;
1172
1173         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1174          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1175         if (!nf_conntrack_htable_size) {
1176                 nf_conntrack_htable_size
1177                         = (((num_physpages << PAGE_SHIFT) / 16384)
1178                            / sizeof(struct hlist_head));
1179                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1180                         nf_conntrack_htable_size = 16384;
1181                 if (nf_conntrack_htable_size < 32)
1182                         nf_conntrack_htable_size = 32;
1183
1184                 /* Use a max. factor of four by default to get the same max as
1185                  * with the old struct list_heads. When a table size is given
1186                  * we use the old value of 8 to avoid reducing the max.
1187                  * entries. */
1188                 max_factor = 4;
1189         }
1190         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1191
1192         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1193                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1194                nf_conntrack_max);
1195
1196         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
1197                                                 sizeof(struct nf_conn),
1198                                                 0, SLAB_DESTROY_BY_RCU, NULL);
1199         if (!nf_conntrack_cachep) {
1200                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1201                 ret = -ENOMEM;
1202                 goto err_cache;
1203         }
1204
1205         ret = nf_conntrack_proto_init();
1206         if (ret < 0)
1207                 goto err_proto;
1208
1209         ret = nf_conntrack_helper_init();
1210         if (ret < 0)
1211                 goto err_helper;
1212
1213         return 0;
1214
1215 err_helper:
1216         nf_conntrack_proto_fini();
1217 err_proto:
1218         kmem_cache_destroy(nf_conntrack_cachep);
1219 err_cache:
1220         return ret;
1221 }
1222
1223 static int nf_conntrack_init_net(struct net *net)
1224 {
1225         int ret;
1226
1227         atomic_set(&net->ct.count, 0);
1228         INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, 0);
1229         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1230         if (!net->ct.stat) {
1231                 ret = -ENOMEM;
1232                 goto err_stat;
1233         }
1234         ret = nf_conntrack_ecache_init(net);
1235         if (ret < 0)
1236                 goto err_ecache;
1237         net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
1238                                              &net->ct.hash_vmalloc, 1);
1239         if (!net->ct.hash) {
1240                 ret = -ENOMEM;
1241                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1242                 goto err_hash;
1243         }
1244         ret = nf_conntrack_expect_init(net);
1245         if (ret < 0)
1246                 goto err_expect;
1247         ret = nf_conntrack_acct_init(net);
1248         if (ret < 0)
1249                 goto err_acct;
1250
1251         /* Set up fake conntrack:
1252             - to never be deleted, not in any hashes */
1253 #ifdef CONFIG_NET_NS
1254         nf_conntrack_untracked.ct_net = &init_net;
1255 #endif
1256         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1257         /*  - and look it like as a confirmed connection */
1258         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1259
1260         return 0;
1261
1262 err_acct:
1263         nf_conntrack_expect_fini(net);
1264 err_expect:
1265         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1266                              nf_conntrack_htable_size);
1267 err_hash:
1268         nf_conntrack_ecache_fini(net);
1269 err_ecache:
1270         free_percpu(net->ct.stat);
1271 err_stat:
1272         return ret;
1273 }
1274
1275 int nf_conntrack_init(struct net *net)
1276 {
1277         int ret;
1278
1279         if (net_eq(net, &init_net)) {
1280                 ret = nf_conntrack_init_init_net();
1281                 if (ret < 0)
1282                         goto out_init_net;
1283         }
1284         ret = nf_conntrack_init_net(net);
1285         if (ret < 0)
1286                 goto out_net;
1287
1288         if (net_eq(net, &init_net)) {
1289                 /* For use by REJECT target */
1290                 rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1291                 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1292         }
1293         return 0;
1294
1295 out_net:
1296         if (net_eq(net, &init_net))
1297                 nf_conntrack_cleanup_init_net();
1298 out_init_net:
1299         return ret;
1300 }