[NETFILTER]: nf_conntrack: endian annotations
[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  * 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
14  *      - new API and handling of conntrack/nat helpers
15  *      - now capable of multiple expectations for one master
16  * 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
17  *      - add usage/reference counts to ip_conntrack_expect
18  *      - export ip_conntrack[_expect]_{find_get,put} functions
19  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
20  *      - generalize L3 protocol denendent part.
21  * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
22  *      - add support various size of conntrack structures.
23  * 26 Jan 2006: Harald Welte <laforge@netfilter.org>
24  *      - restructure nf_conn (introduce nf_conn_help)
25  *      - redesign 'features' how they were originally intended
26  * 26 Feb 2006: Pablo Neira Ayuso <pablo@eurodev.net>
27  *      - add support for L3 protocol module load on demand.
28  *
29  * Derived from net/ipv4/netfilter/ip_conntrack_core.c
30  */
31
32 #include <linux/types.h>
33 #include <linux/netfilter.h>
34 #include <linux/module.h>
35 #include <linux/skbuff.h>
36 #include <linux/proc_fs.h>
37 #include <linux/vmalloc.h>
38 #include <linux/stddef.h>
39 #include <linux/slab.h>
40 #include <linux/random.h>
41 #include <linux/jhash.h>
42 #include <linux/err.h>
43 #include <linux/percpu.h>
44 #include <linux/moduleparam.h>
45 #include <linux/notifier.h>
46 #include <linux/kernel.h>
47 #include <linux/netdevice.h>
48 #include <linux/socket.h>
49
50 #include <net/netfilter/nf_conntrack.h>
51 #include <net/netfilter/nf_conntrack_l3proto.h>
52 #include <net/netfilter/nf_conntrack_l4proto.h>
53 #include <net/netfilter/nf_conntrack_expect.h>
54 #include <net/netfilter/nf_conntrack_helper.h>
55 #include <net/netfilter/nf_conntrack_core.h>
56
57 #define NF_CONNTRACK_VERSION    "0.5.0"
58
59 #if 0
60 #define DEBUGP printk
61 #else
62 #define DEBUGP(format, args...)
63 #endif
64
65 DEFINE_RWLOCK(nf_conntrack_lock);
66
67 /* nf_conntrack_standalone needs this */
68 atomic_t nf_conntrack_count = ATOMIC_INIT(0);
69 EXPORT_SYMBOL_GPL(nf_conntrack_count);
70
71 void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL;
72 unsigned int nf_conntrack_htable_size __read_mostly;
73 int nf_conntrack_max __read_mostly;
74 EXPORT_SYMBOL_GPL(nf_conntrack_max);
75 struct list_head *nf_conntrack_hash __read_mostly;
76 struct nf_conn nf_conntrack_untracked __read_mostly;
77 unsigned int nf_ct_log_invalid __read_mostly;
78 LIST_HEAD(unconfirmed);
79 static int nf_conntrack_vmalloc __read_mostly;
80
81 static unsigned int nf_conntrack_next_id;
82
83 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
84 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
85
86 /*
87  * This scheme offers various size of "struct nf_conn" dependent on
88  * features(helper, nat, ...)
89  */
90
91 #define NF_CT_FEATURES_NAMELEN  256
92 static struct {
93         /* name of slab cache. printed in /proc/slabinfo */
94         char *name;
95
96         /* size of slab cache */
97         size_t size;
98
99         /* slab cache pointer */
100         kmem_cache_t *cachep;
101
102         /* allocated slab cache + modules which uses this slab cache */
103         int use;
104
105 } nf_ct_cache[NF_CT_F_NUM];
106
107 /* protect members of nf_ct_cache except of "use" */
108 DEFINE_RWLOCK(nf_ct_cache_lock);
109
110 /* This avoids calling kmem_cache_create() with same name simultaneously */
111 static DEFINE_MUTEX(nf_ct_cache_mutex);
112
113 static int nf_conntrack_hash_rnd_initted;
114 static unsigned int nf_conntrack_hash_rnd;
115
116 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
117                                   unsigned int size, unsigned int rnd)
118 {
119         unsigned int a, b;
120         a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all),
121                   ((tuple->src.l3num) << 16) | tuple->dst.protonum);
122         b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all),
123                         (tuple->src.u.all << 16) | tuple->dst.u.all);
124
125         return jhash_2words(a, b, rnd) % size;
126 }
127
128 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
129 {
130         return __hash_conntrack(tuple, nf_conntrack_htable_size,
131                                 nf_conntrack_hash_rnd);
132 }
133
134 int nf_conntrack_register_cache(u_int32_t features, const char *name,
135                                 size_t size)
136 {
137         int ret = 0;
138         char *cache_name;
139         kmem_cache_t *cachep;
140
141         DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n",
142                features, name, size);
143
144         if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) {
145                 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n",
146                         features);
147                 return -EINVAL;
148         }
149
150         mutex_lock(&nf_ct_cache_mutex);
151
152         write_lock_bh(&nf_ct_cache_lock);
153         /* e.g: multiple helpers are loaded */
154         if (nf_ct_cache[features].use > 0) {
155                 DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
156                 if ((!strncmp(nf_ct_cache[features].name, name,
157                               NF_CT_FEATURES_NAMELEN))
158                     && nf_ct_cache[features].size == size) {
159                         DEBUGP("nf_conntrack_register_cache: reusing.\n");
160                         nf_ct_cache[features].use++;
161                         ret = 0;
162                 } else
163                         ret = -EBUSY;
164
165                 write_unlock_bh(&nf_ct_cache_lock);
166                 mutex_unlock(&nf_ct_cache_mutex);
167                 return ret;
168         }
169         write_unlock_bh(&nf_ct_cache_lock);
170
171         /*
172          * The memory space for name of slab cache must be alive until
173          * cache is destroyed.
174          */
175         cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC);
176         if (cache_name == NULL) {
177                 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n");
178                 ret = -ENOMEM;
179                 goto out_up_mutex;
180         }
181
182         if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN)
183                                                 >= NF_CT_FEATURES_NAMELEN) {
184                 printk("nf_conntrack_register_cache: name too long\n");
185                 ret = -EINVAL;
186                 goto out_free_name;
187         }
188
189         cachep = kmem_cache_create(cache_name, size, 0, 0,
190                                    NULL, NULL);
191         if (!cachep) {
192                 printk("nf_conntrack_register_cache: Can't create slab cache "
193                        "for the features = 0x%x\n", features);
194                 ret = -ENOMEM;
195                 goto out_free_name;
196         }
197
198         write_lock_bh(&nf_ct_cache_lock);
199         nf_ct_cache[features].use = 1;
200         nf_ct_cache[features].size = size;
201         nf_ct_cache[features].cachep = cachep;
202         nf_ct_cache[features].name = cache_name;
203         write_unlock_bh(&nf_ct_cache_lock);
204
205         goto out_up_mutex;
206
207 out_free_name:
208         kfree(cache_name);
209 out_up_mutex:
210         mutex_unlock(&nf_ct_cache_mutex);
211         return ret;
212 }
213
214 /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */
215 void nf_conntrack_unregister_cache(u_int32_t features)
216 {
217         kmem_cache_t *cachep;
218         char *name;
219
220         /*
221          * This assures that kmem_cache_create() isn't called before destroying
222          * slab cache.
223          */
224         DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features);
225         mutex_lock(&nf_ct_cache_mutex);
226
227         write_lock_bh(&nf_ct_cache_lock);
228         if (--nf_ct_cache[features].use > 0) {
229                 write_unlock_bh(&nf_ct_cache_lock);
230                 mutex_unlock(&nf_ct_cache_mutex);
231                 return;
232         }
233         cachep = nf_ct_cache[features].cachep;
234         name = nf_ct_cache[features].name;
235         nf_ct_cache[features].cachep = NULL;
236         nf_ct_cache[features].name = NULL;
237         nf_ct_cache[features].size = 0;
238         write_unlock_bh(&nf_ct_cache_lock);
239
240         synchronize_net();
241
242         kmem_cache_destroy(cachep);
243         kfree(name);
244
245         mutex_unlock(&nf_ct_cache_mutex);
246 }
247
248 int
249 nf_ct_get_tuple(const struct sk_buff *skb,
250                 unsigned int nhoff,
251                 unsigned int dataoff,
252                 u_int16_t l3num,
253                 u_int8_t protonum,
254                 struct nf_conntrack_tuple *tuple,
255                 const struct nf_conntrack_l3proto *l3proto,
256                 const struct nf_conntrack_l4proto *l4proto)
257 {
258         NF_CT_TUPLE_U_BLANK(tuple);
259
260         tuple->src.l3num = l3num;
261         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
262                 return 0;
263
264         tuple->dst.protonum = protonum;
265         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
266
267         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
268 }
269
270 int
271 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
272                    const struct nf_conntrack_tuple *orig,
273                    const struct nf_conntrack_l3proto *l3proto,
274                    const struct nf_conntrack_l4proto *l4proto)
275 {
276         NF_CT_TUPLE_U_BLANK(inverse);
277
278         inverse->src.l3num = orig->src.l3num;
279         if (l3proto->invert_tuple(inverse, orig) == 0)
280                 return 0;
281
282         inverse->dst.dir = !orig->dst.dir;
283
284         inverse->dst.protonum = orig->dst.protonum;
285         return l4proto->invert_tuple(inverse, orig);
286 }
287
288 static void
289 clean_from_lists(struct nf_conn *ct)
290 {
291         DEBUGP("clean_from_lists(%p)\n", ct);
292         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
293         list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list);
294
295         /* Destroy all pending expectations */
296         nf_ct_remove_expectations(ct);
297 }
298
299 static void
300 destroy_conntrack(struct nf_conntrack *nfct)
301 {
302         struct nf_conn *ct = (struct nf_conn *)nfct;
303         struct nf_conntrack_l3proto *l3proto;
304         struct nf_conntrack_l4proto *l4proto;
305
306         DEBUGP("destroy_conntrack(%p)\n", ct);
307         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
308         NF_CT_ASSERT(!timer_pending(&ct->timeout));
309
310         nf_conntrack_event(IPCT_DESTROY, ct);
311         set_bit(IPS_DYING_BIT, &ct->status);
312
313         /* To make sure we don't get any weird locking issues here:
314          * destroy_conntrack() MUST NOT be called with a write lock
315          * to nf_conntrack_lock!!! -HW */
316         l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num);
317         if (l3proto && l3proto->destroy)
318                 l3proto->destroy(ct);
319
320         l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
321         if (l4proto && l4proto->destroy)
322                 l4proto->destroy(ct);
323
324         if (nf_conntrack_destroyed)
325                 nf_conntrack_destroyed(ct);
326
327         write_lock_bh(&nf_conntrack_lock);
328         /* Expectations will have been removed in clean_from_lists,
329          * except TFTP can create an expectation on the first packet,
330          * before connection is in the list, so we need to clean here,
331          * too. */
332         nf_ct_remove_expectations(ct);
333
334         /* We overload first tuple to link into unconfirmed list. */
335         if (!nf_ct_is_confirmed(ct)) {
336                 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
337                 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
338         }
339
340         NF_CT_STAT_INC(delete);
341         write_unlock_bh(&nf_conntrack_lock);
342
343         if (ct->master)
344                 nf_ct_put(ct->master);
345
346         DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
347         nf_conntrack_free(ct);
348 }
349
350 static void death_by_timeout(unsigned long ul_conntrack)
351 {
352         struct nf_conn *ct = (void *)ul_conntrack;
353
354         write_lock_bh(&nf_conntrack_lock);
355         /* Inside lock so preempt is disabled on module removal path.
356          * Otherwise we can get spurious warnings. */
357         NF_CT_STAT_INC(delete_list);
358         clean_from_lists(ct);
359         write_unlock_bh(&nf_conntrack_lock);
360         nf_ct_put(ct);
361 }
362
363 struct nf_conntrack_tuple_hash *
364 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
365                     const struct nf_conn *ignored_conntrack)
366 {
367         struct nf_conntrack_tuple_hash *h;
368         unsigned int hash = hash_conntrack(tuple);
369
370         list_for_each_entry(h, &nf_conntrack_hash[hash], list) {
371                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
372                     nf_ct_tuple_equal(tuple, &h->tuple)) {
373                         NF_CT_STAT_INC(found);
374                         return h;
375                 }
376                 NF_CT_STAT_INC(searched);
377         }
378
379         return NULL;
380 }
381
382 /* Find a connection corresponding to a tuple. */
383 struct nf_conntrack_tuple_hash *
384 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple,
385                       const struct nf_conn *ignored_conntrack)
386 {
387         struct nf_conntrack_tuple_hash *h;
388
389         read_lock_bh(&nf_conntrack_lock);
390         h = __nf_conntrack_find(tuple, ignored_conntrack);
391         if (h)
392                 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
393         read_unlock_bh(&nf_conntrack_lock);
394
395         return h;
396 }
397
398 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
399                                        unsigned int hash,
400                                        unsigned int repl_hash) 
401 {
402         ct->id = ++nf_conntrack_next_id;
403         list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list,
404                  &nf_conntrack_hash[hash]);
405         list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list,
406                  &nf_conntrack_hash[repl_hash]);
407 }
408
409 void nf_conntrack_hash_insert(struct nf_conn *ct)
410 {
411         unsigned int hash, repl_hash;
412
413         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
414         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
415
416         write_lock_bh(&nf_conntrack_lock);
417         __nf_conntrack_hash_insert(ct, hash, repl_hash);
418         write_unlock_bh(&nf_conntrack_lock);
419 }
420
421 /* Confirm a connection given skb; places it in hash table */
422 int
423 __nf_conntrack_confirm(struct sk_buff **pskb)
424 {
425         unsigned int hash, repl_hash;
426         struct nf_conntrack_tuple_hash *h;
427         struct nf_conn *ct;
428         struct nf_conn_help *help;
429         enum ip_conntrack_info ctinfo;
430
431         ct = nf_ct_get(*pskb, &ctinfo);
432
433         /* ipt_REJECT uses nf_conntrack_attach to attach related
434            ICMP/TCP RST packets in other direction.  Actual packet
435            which created connection will be IP_CT_NEW or for an
436            expected connection, IP_CT_RELATED. */
437         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
438                 return NF_ACCEPT;
439
440         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
441         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
442
443         /* We're not in hash table, and we refuse to set up related
444            connections for unconfirmed conns.  But packet copies and
445            REJECT will give spurious warnings here. */
446         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
447
448         /* No external references means noone else could have
449            confirmed us. */
450         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
451         DEBUGP("Confirming conntrack %p\n", ct);
452
453         write_lock_bh(&nf_conntrack_lock);
454
455         /* See if there's one in the list already, including reverse:
456            NAT could have grabbed it without realizing, since we're
457            not in the hash.  If there is, we lost race. */
458         list_for_each_entry(h, &nf_conntrack_hash[hash], list)
459                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
460                                       &h->tuple))
461                         goto out;
462         list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list)
463                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
464                                       &h->tuple))
465                         goto out;
466
467         /* Remove from unconfirmed list */
468         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
469
470         __nf_conntrack_hash_insert(ct, hash, repl_hash);
471         /* Timer relative to confirmation time, not original
472            setting time, otherwise we'd get timer wrap in
473            weird delay cases. */
474         ct->timeout.expires += jiffies;
475         add_timer(&ct->timeout);
476         atomic_inc(&ct->ct_general.use);
477         set_bit(IPS_CONFIRMED_BIT, &ct->status);
478         NF_CT_STAT_INC(insert);
479         write_unlock_bh(&nf_conntrack_lock);
480         help = nfct_help(ct);
481         if (help && help->helper)
482                 nf_conntrack_event_cache(IPCT_HELPER, *pskb);
483 #ifdef CONFIG_NF_NAT_NEEDED
484         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
485             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
486                 nf_conntrack_event_cache(IPCT_NATINFO, *pskb);
487 #endif
488         nf_conntrack_event_cache(master_ct(ct) ?
489                                  IPCT_RELATED : IPCT_NEW, *pskb);
490         return NF_ACCEPT;
491
492 out:
493         NF_CT_STAT_INC(insert_failed);
494         write_unlock_bh(&nf_conntrack_lock);
495         return NF_DROP;
496 }
497
498 /* Returns true if a connection correspondings to the tuple (required
499    for NAT). */
500 int
501 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
502                          const struct nf_conn *ignored_conntrack)
503 {
504         struct nf_conntrack_tuple_hash *h;
505
506         read_lock_bh(&nf_conntrack_lock);
507         h = __nf_conntrack_find(tuple, ignored_conntrack);
508         read_unlock_bh(&nf_conntrack_lock);
509
510         return h != NULL;
511 }
512
513 /* There's a small race here where we may free a just-assured
514    connection.  Too bad: we're in trouble anyway. */
515 static int early_drop(struct list_head *chain)
516 {
517         /* Traverse backwards: gives us oldest, which is roughly LRU */
518         struct nf_conntrack_tuple_hash *h;
519         struct nf_conn *ct = NULL, *tmp;
520         int dropped = 0;
521
522         read_lock_bh(&nf_conntrack_lock);
523         list_for_each_entry_reverse(h, chain, list) {
524                 tmp = nf_ct_tuplehash_to_ctrack(h);
525                 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) {
526                         ct = tmp;
527                         atomic_inc(&ct->ct_general.use);
528                         break;
529                 }
530         }
531         read_unlock_bh(&nf_conntrack_lock);
532
533         if (!ct)
534                 return dropped;
535
536         if (del_timer(&ct->timeout)) {
537                 death_by_timeout((unsigned long)ct);
538                 dropped = 1;
539                 NF_CT_STAT_INC(early_drop);
540         }
541         nf_ct_put(ct);
542         return dropped;
543 }
544
545 static struct nf_conn *
546 __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
547                      const struct nf_conntrack_tuple *repl,
548                      const struct nf_conntrack_l3proto *l3proto)
549 {
550         struct nf_conn *conntrack = NULL;
551         u_int32_t features = 0;
552         struct nf_conntrack_helper *helper;
553
554         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
555                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
556                 nf_conntrack_hash_rnd_initted = 1;
557         }
558
559         /* We don't want any race condition at early drop stage */
560         atomic_inc(&nf_conntrack_count);
561
562         if (nf_conntrack_max
563             && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
564                 unsigned int hash = hash_conntrack(orig);
565                 /* Try dropping from this hash chain. */
566                 if (!early_drop(&nf_conntrack_hash[hash])) {
567                         atomic_dec(&nf_conntrack_count);
568                         if (net_ratelimit())
569                                 printk(KERN_WARNING
570                                        "nf_conntrack: table full, dropping"
571                                        " packet.\n");
572                         return ERR_PTR(-ENOMEM);
573                 }
574         }
575
576         /*  find features needed by this conntrack. */
577         features = l3proto->get_features(orig);
578
579         /* FIXME: protect helper list per RCU */
580         read_lock_bh(&nf_conntrack_lock);
581         helper = __nf_ct_helper_find(repl);
582         if (helper)
583                 features |= NF_CT_F_HELP;
584         read_unlock_bh(&nf_conntrack_lock);
585
586         DEBUGP("nf_conntrack_alloc: features=0x%x\n", features);
587
588         read_lock_bh(&nf_ct_cache_lock);
589
590         if (unlikely(!nf_ct_cache[features].use)) {
591                 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
592                         features);
593                 goto out;
594         }
595
596         conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC);
597         if (conntrack == NULL) {
598                 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n");
599                 goto out;
600         }
601
602         memset(conntrack, 0, nf_ct_cache[features].size);
603         conntrack->features = features;
604         atomic_set(&conntrack->ct_general.use, 1);
605         conntrack->ct_general.destroy = destroy_conntrack;
606         conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
607         conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
608         /* Don't set timer yet: wait for confirmation */
609         init_timer(&conntrack->timeout);
610         conntrack->timeout.data = (unsigned long)conntrack;
611         conntrack->timeout.function = death_by_timeout;
612         read_unlock_bh(&nf_ct_cache_lock);
613
614         return conntrack;
615 out:
616         read_unlock_bh(&nf_ct_cache_lock);
617         atomic_dec(&nf_conntrack_count);
618         return conntrack;
619 }
620
621 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
622                                    const struct nf_conntrack_tuple *repl)
623 {
624         struct nf_conntrack_l3proto *l3proto;
625
626         l3proto = __nf_ct_l3proto_find(orig->src.l3num);
627         return __nf_conntrack_alloc(orig, repl, l3proto);
628 }
629
630 void nf_conntrack_free(struct nf_conn *conntrack)
631 {
632         u_int32_t features = conntrack->features;
633         NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM);
634         DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features,
635                conntrack);
636         kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
637         atomic_dec(&nf_conntrack_count);
638 }
639
640 /* Allocate a new conntrack: we return -ENOMEM if classification
641    failed due to stress.  Otherwise it really is unclassifiable. */
642 static struct nf_conntrack_tuple_hash *
643 init_conntrack(const struct nf_conntrack_tuple *tuple,
644                struct nf_conntrack_l3proto *l3proto,
645                struct nf_conntrack_l4proto *l4proto,
646                struct sk_buff *skb,
647                unsigned int dataoff)
648 {
649         struct nf_conn *conntrack;
650         struct nf_conntrack_tuple repl_tuple;
651         struct nf_conntrack_expect *exp;
652
653         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
654                 DEBUGP("Can't invert tuple.\n");
655                 return NULL;
656         }
657
658         conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto);
659         if (conntrack == NULL || IS_ERR(conntrack)) {
660                 DEBUGP("Can't allocate conntrack.\n");
661                 return (struct nf_conntrack_tuple_hash *)conntrack;
662         }
663
664         if (!l4proto->new(conntrack, skb, dataoff)) {
665                 nf_conntrack_free(conntrack);
666                 DEBUGP("init conntrack: can't track with proto module\n");
667                 return NULL;
668         }
669
670         write_lock_bh(&nf_conntrack_lock);
671         exp = find_expectation(tuple);
672
673         if (exp) {
674                 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
675                         conntrack, exp);
676                 /* Welcome, Mr. Bond.  We've been expecting you... */
677                 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
678                 conntrack->master = exp->master;
679 #ifdef CONFIG_NF_CONNTRACK_MARK
680                 conntrack->mark = exp->master->mark;
681 #endif
682 #ifdef CONFIG_NF_CONNTRACK_SECMARK
683                 conntrack->secmark = exp->master->secmark;
684 #endif
685                 nf_conntrack_get(&conntrack->master->ct_general);
686                 NF_CT_STAT_INC(expect_new);
687         } else {
688                 struct nf_conn_help *help = nfct_help(conntrack);
689
690                 if (help)
691                         help->helper = __nf_ct_helper_find(&repl_tuple);
692                 NF_CT_STAT_INC(new);
693         }
694
695         /* Overload tuple linked list to put us in unconfirmed list. */
696         list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
697
698         write_unlock_bh(&nf_conntrack_lock);
699
700         if (exp) {
701                 if (exp->expectfn)
702                         exp->expectfn(conntrack, exp);
703                 nf_conntrack_expect_put(exp);
704         }
705
706         return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
707 }
708
709 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
710 static inline struct nf_conn *
711 resolve_normal_ct(struct sk_buff *skb,
712                   unsigned int dataoff,
713                   u_int16_t l3num,
714                   u_int8_t protonum,
715                   struct nf_conntrack_l3proto *l3proto,
716                   struct nf_conntrack_l4proto *l4proto,
717                   int *set_reply,
718                   enum ip_conntrack_info *ctinfo)
719 {
720         struct nf_conntrack_tuple tuple;
721         struct nf_conntrack_tuple_hash *h;
722         struct nf_conn *ct;
723
724         if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data),
725                              dataoff, l3num, protonum, &tuple, l3proto,
726                              l4proto)) {
727                 DEBUGP("resolve_normal_ct: Can't get tuple\n");
728                 return NULL;
729         }
730
731         /* look for tuple match */
732         h = nf_conntrack_find_get(&tuple, NULL);
733         if (!h) {
734                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
735                 if (!h)
736                         return NULL;
737                 if (IS_ERR(h))
738                         return (void *)h;
739         }
740         ct = nf_ct_tuplehash_to_ctrack(h);
741
742         /* It exists; we have (non-exclusive) reference. */
743         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
744                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
745                 /* Please set reply bit if this packet OK */
746                 *set_reply = 1;
747         } else {
748                 /* Once we've had two way comms, always ESTABLISHED. */
749                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
750                         DEBUGP("nf_conntrack_in: normal packet for %p\n", ct);
751                         *ctinfo = IP_CT_ESTABLISHED;
752                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
753                         DEBUGP("nf_conntrack_in: related packet for %p\n", ct);
754                         *ctinfo = IP_CT_RELATED;
755                 } else {
756                         DEBUGP("nf_conntrack_in: new packet for %p\n", ct);
757                         *ctinfo = IP_CT_NEW;
758                 }
759                 *set_reply = 0;
760         }
761         skb->nfct = &ct->ct_general;
762         skb->nfctinfo = *ctinfo;
763         return ct;
764 }
765
766 unsigned int
767 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
768 {
769         struct nf_conn *ct;
770         enum ip_conntrack_info ctinfo;
771         struct nf_conntrack_l3proto *l3proto;
772         struct nf_conntrack_l4proto *l4proto;
773         unsigned int dataoff;
774         u_int8_t protonum;
775         int set_reply = 0;
776         int ret;
777
778         /* Previously seen (loopback or untracked)?  Ignore. */
779         if ((*pskb)->nfct) {
780                 NF_CT_STAT_INC(ignore);
781                 return NF_ACCEPT;
782         }
783
784         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
785         if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) {
786                 DEBUGP("not prepared to track yet or error occured\n");
787                 return -ret;
788         }
789
790         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
791
792         /* It may be an special packet, error, unclean...
793          * inverse of the return code tells to the netfilter
794          * core what to do with the packet. */
795         if (l4proto->error != NULL &&
796             (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
797                 NF_CT_STAT_INC(error);
798                 NF_CT_STAT_INC(invalid);
799                 return -ret;
800         }
801
802         ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto,
803                                &set_reply, &ctinfo);
804         if (!ct) {
805                 /* Not valid part of a connection */
806                 NF_CT_STAT_INC(invalid);
807                 return NF_ACCEPT;
808         }
809
810         if (IS_ERR(ct)) {
811                 /* Too stressed to deal. */
812                 NF_CT_STAT_INC(drop);
813                 return NF_DROP;
814         }
815
816         NF_CT_ASSERT((*pskb)->nfct);
817
818         ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum);
819         if (ret < 0) {
820                 /* Invalid: inverse of the return code tells
821                  * the netfilter core what to do */
822                 DEBUGP("nf_conntrack_in: Can't track with proto module\n");
823                 nf_conntrack_put((*pskb)->nfct);
824                 (*pskb)->nfct = NULL;
825                 NF_CT_STAT_INC(invalid);
826                 return -ret;
827         }
828
829         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
830                 nf_conntrack_event_cache(IPCT_STATUS, *pskb);
831
832         return ret;
833 }
834
835 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
836                          const struct nf_conntrack_tuple *orig)
837 {
838         return nf_ct_invert_tuple(inverse, orig,
839                                   __nf_ct_l3proto_find(orig->src.l3num),
840                                   __nf_ct_l4proto_find(orig->src.l3num,
841                                                      orig->dst.protonum));
842 }
843
844 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
845 void __nf_ct_refresh_acct(struct nf_conn *ct,
846                           enum ip_conntrack_info ctinfo,
847                           const struct sk_buff *skb,
848                           unsigned long extra_jiffies,
849                           int do_acct)
850 {
851         int event = 0;
852
853         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
854         NF_CT_ASSERT(skb);
855
856         write_lock_bh(&nf_conntrack_lock);
857
858         /* Only update if this is not a fixed timeout */
859         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
860                 write_unlock_bh(&nf_conntrack_lock);
861                 return;
862         }
863
864         /* If not in hash table, timer will not be active yet */
865         if (!nf_ct_is_confirmed(ct)) {
866                 ct->timeout.expires = extra_jiffies;
867                 event = IPCT_REFRESH;
868         } else {
869                 unsigned long newtime = jiffies + extra_jiffies;
870
871                 /* Only update the timeout if the new timeout is at least
872                    HZ jiffies from the old timeout. Need del_timer for race
873                    avoidance (may already be dying). */
874                 if (newtime - ct->timeout.expires >= HZ
875                     && del_timer(&ct->timeout)) {
876                         ct->timeout.expires = newtime;
877                         add_timer(&ct->timeout);
878                         event = IPCT_REFRESH;
879                 }
880         }
881
882 #ifdef CONFIG_NF_CT_ACCT
883         if (do_acct) {
884                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
885                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
886                         skb->len - (unsigned int)(skb->nh.raw - skb->data);
887
888                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
889                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
890                         event |= IPCT_COUNTER_FILLING;
891         }
892 #endif
893
894         write_unlock_bh(&nf_conntrack_lock);
895
896         /* must be unlocked when calling event cache */
897         if (event)
898                 nf_conntrack_event_cache(event, skb);
899 }
900
901 #if defined(CONFIG_NF_CT_NETLINK) || \
902     defined(CONFIG_NF_CT_NETLINK_MODULE)
903
904 #include <linux/netfilter/nfnetlink.h>
905 #include <linux/netfilter/nfnetlink_conntrack.h>
906 #include <linux/mutex.h>
907
908
909 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
910  * in ip_conntrack_core, since we don't want the protocols to autoload
911  * or depend on ctnetlink */
912 int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
913                                const struct nf_conntrack_tuple *tuple)
914 {
915         NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
916                 &tuple->src.u.tcp.port);
917         NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
918                 &tuple->dst.u.tcp.port);
919         return 0;
920
921 nfattr_failure:
922         return -1;
923 }
924
925 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
926         [CTA_PROTO_SRC_PORT-1]  = sizeof(u_int16_t),
927         [CTA_PROTO_DST_PORT-1]  = sizeof(u_int16_t)
928 };
929
930 int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
931                                struct nf_conntrack_tuple *t)
932 {
933         if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
934                 return -EINVAL;
935
936         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
937                 return -EINVAL;
938
939         t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
940         t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
941
942         return 0;
943 }
944 #endif
945
946 /* Used by ipt_REJECT and ip6t_REJECT. */
947 void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
948 {
949         struct nf_conn *ct;
950         enum ip_conntrack_info ctinfo;
951
952         /* This ICMP is in reverse direction to the packet which caused it */
953         ct = nf_ct_get(skb, &ctinfo);
954         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
955                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
956         else
957                 ctinfo = IP_CT_RELATED;
958
959         /* Attach to new skbuff, and increment count */
960         nskb->nfct = &ct->ct_general;
961         nskb->nfctinfo = ctinfo;
962         nf_conntrack_get(nskb->nfct);
963 }
964
965 static inline int
966 do_iter(const struct nf_conntrack_tuple_hash *i,
967         int (*iter)(struct nf_conn *i, void *data),
968         void *data)
969 {
970         return iter(nf_ct_tuplehash_to_ctrack(i), data);
971 }
972
973 /* Bring out ya dead! */
974 static struct nf_conn *
975 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
976                 void *data, unsigned int *bucket)
977 {
978         struct nf_conntrack_tuple_hash *h;
979         struct nf_conn *ct;
980
981         write_lock_bh(&nf_conntrack_lock);
982         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
983                 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) {
984                         ct = nf_ct_tuplehash_to_ctrack(h);
985                         if (iter(ct, data))
986                                 goto found;
987                 }
988         }
989         list_for_each_entry(h, &unconfirmed, list) {
990                 ct = nf_ct_tuplehash_to_ctrack(h);
991                 if (iter(ct, data))
992                         goto found;
993         }
994         write_unlock_bh(&nf_conntrack_lock);
995         return NULL;
996 found:
997         atomic_inc(&ct->ct_general.use);
998         write_unlock_bh(&nf_conntrack_lock);
999         return ct;
1000 }
1001
1002 void
1003 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
1004 {
1005         struct nf_conn *ct;
1006         unsigned int bucket = 0;
1007
1008         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
1009                 /* Time to push up daises... */
1010                 if (del_timer(&ct->timeout))
1011                         death_by_timeout((unsigned long)ct);
1012                 /* ... else the timer will get him soon. */
1013
1014                 nf_ct_put(ct);
1015         }
1016 }
1017
1018 static int kill_all(struct nf_conn *i, void *data)
1019 {
1020         return 1;
1021 }
1022
1023 static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size)
1024 {
1025         if (vmalloced)
1026                 vfree(hash);
1027         else
1028                 free_pages((unsigned long)hash, 
1029                            get_order(sizeof(struct list_head) * size));
1030 }
1031
1032 void nf_conntrack_flush()
1033 {
1034         nf_ct_iterate_cleanup(kill_all, NULL);
1035 }
1036
1037 /* Mishearing the voices in his head, our hero wonders how he's
1038    supposed to kill the mall. */
1039 void nf_conntrack_cleanup(void)
1040 {
1041         int i;
1042
1043         ip_ct_attach = NULL;
1044
1045         /* This makes sure all current packets have passed through
1046            netfilter framework.  Roll on, two-stage module
1047            delete... */
1048         synchronize_net();
1049
1050         nf_ct_event_cache_flush();
1051  i_see_dead_people:
1052         nf_conntrack_flush();
1053         if (atomic_read(&nf_conntrack_count) != 0) {
1054                 schedule();
1055                 goto i_see_dead_people;
1056         }
1057         /* wait until all references to nf_conntrack_untracked are dropped */
1058         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1059                 schedule();
1060
1061         for (i = 0; i < NF_CT_F_NUM; i++) {
1062                 if (nf_ct_cache[i].use == 0)
1063                         continue;
1064
1065                 NF_CT_ASSERT(nf_ct_cache[i].use == 1);
1066                 nf_ct_cache[i].use = 1;
1067                 nf_conntrack_unregister_cache(i);
1068         }
1069         kmem_cache_destroy(nf_conntrack_expect_cachep);
1070         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1071                             nf_conntrack_htable_size);
1072
1073         nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic);
1074
1075         /* free l3proto protocol tables */
1076         for (i = 0; i < PF_MAX; i++)
1077                 if (nf_ct_protos[i]) {
1078                         kfree(nf_ct_protos[i]);
1079                         nf_ct_protos[i] = NULL;
1080                 }
1081 }
1082
1083 static struct list_head *alloc_hashtable(int size, int *vmalloced)
1084 {
1085         struct list_head *hash;
1086         unsigned int i;
1087
1088         *vmalloced = 0; 
1089         hash = (void*)__get_free_pages(GFP_KERNEL, 
1090                                        get_order(sizeof(struct list_head)
1091                                                  * size));
1092         if (!hash) { 
1093                 *vmalloced = 1;
1094                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1095                 hash = vmalloc(sizeof(struct list_head) * size);
1096         }
1097
1098         if (hash)
1099                 for (i = 0; i < size; i++) 
1100                         INIT_LIST_HEAD(&hash[i]);
1101
1102         return hash;
1103 }
1104
1105 int set_hashsize(const char *val, struct kernel_param *kp)
1106 {
1107         int i, bucket, hashsize, vmalloced;
1108         int old_vmalloced, old_size;
1109         int rnd;
1110         struct list_head *hash, *old_hash;
1111         struct nf_conntrack_tuple_hash *h;
1112
1113         /* On boot, we can set this without any fancy locking. */
1114         if (!nf_conntrack_htable_size)
1115                 return param_set_uint(val, kp);
1116
1117         hashsize = simple_strtol(val, NULL, 0);
1118         if (!hashsize)
1119                 return -EINVAL;
1120
1121         hash = alloc_hashtable(hashsize, &vmalloced);
1122         if (!hash)
1123                 return -ENOMEM;
1124
1125         /* We have to rehahs for the new table anyway, so we also can
1126          * use a newrandom seed */
1127         get_random_bytes(&rnd, 4);
1128
1129         write_lock_bh(&nf_conntrack_lock);
1130         for (i = 0; i < nf_conntrack_htable_size; i++) {
1131                 while (!list_empty(&nf_conntrack_hash[i])) {
1132                         h = list_entry(nf_conntrack_hash[i].next,
1133                                        struct nf_conntrack_tuple_hash, list);
1134                         list_del(&h->list);
1135                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1136                         list_add_tail(&h->list, &hash[bucket]);
1137                 }
1138         }
1139         old_size = nf_conntrack_htable_size;
1140         old_vmalloced = nf_conntrack_vmalloc;
1141         old_hash = nf_conntrack_hash;
1142
1143         nf_conntrack_htable_size = hashsize;
1144         nf_conntrack_vmalloc = vmalloced;
1145         nf_conntrack_hash = hash;
1146         nf_conntrack_hash_rnd = rnd;
1147         write_unlock_bh(&nf_conntrack_lock);
1148
1149         free_conntrack_hash(old_hash, old_vmalloced, old_size);
1150         return 0;
1151 }
1152
1153 module_param_call(hashsize, set_hashsize, param_get_uint,
1154                   &nf_conntrack_htable_size, 0600);
1155
1156 int __init nf_conntrack_init(void)
1157 {
1158         unsigned int i;
1159         int ret;
1160
1161         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1162          * machine has 256 buckets.  >= 1GB machines have 8192 buckets. */
1163         if (!nf_conntrack_htable_size) {
1164                 nf_conntrack_htable_size
1165                         = (((num_physpages << PAGE_SHIFT) / 16384)
1166                            / sizeof(struct list_head));
1167                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1168                         nf_conntrack_htable_size = 8192;
1169                 if (nf_conntrack_htable_size < 16)
1170                         nf_conntrack_htable_size = 16;
1171         }
1172         nf_conntrack_max = 8 * nf_conntrack_htable_size;
1173
1174         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1175                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1176                nf_conntrack_max);
1177
1178         nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size,
1179                                             &nf_conntrack_vmalloc);
1180         if (!nf_conntrack_hash) {
1181                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1182                 goto err_out;
1183         }
1184
1185         ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic",
1186                                           sizeof(struct nf_conn));
1187         if (ret < 0) {
1188                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1189                 goto err_free_hash;
1190         }
1191
1192         nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect",
1193                                         sizeof(struct nf_conntrack_expect),
1194                                         0, 0, NULL, NULL);
1195         if (!nf_conntrack_expect_cachep) {
1196                 printk(KERN_ERR "Unable to create nf_expect slab cache\n");
1197                 goto err_free_conntrack_slab;
1198         }
1199
1200         ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic);
1201         if (ret < 0)
1202                 goto out_free_expect_slab;
1203
1204         /* Don't NEED lock here, but good form anyway. */
1205         write_lock_bh(&nf_conntrack_lock);
1206         for (i = 0; i < AF_MAX; i++)
1207                 nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic;
1208         write_unlock_bh(&nf_conntrack_lock);
1209
1210         /* For use by REJECT target */
1211         ip_ct_attach = __nf_conntrack_attach;
1212
1213         /* Set up fake conntrack:
1214             - to never be deleted, not in any hashes */
1215         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1216         /*  - and look it like as a confirmed connection */
1217         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1218
1219         return ret;
1220
1221 out_free_expect_slab:
1222         kmem_cache_destroy(nf_conntrack_expect_cachep);
1223 err_free_conntrack_slab:
1224         nf_conntrack_unregister_cache(NF_CT_F_BASIC);
1225 err_free_hash:
1226         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1227                             nf_conntrack_htable_size);
1228 err_out:
1229         return -ENOMEM;
1230 }