Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-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  * 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 #include <linux/mm.h>
50
51 #include <net/netfilter/nf_conntrack.h>
52 #include <net/netfilter/nf_conntrack_l3proto.h>
53 #include <net/netfilter/nf_conntrack_l4proto.h>
54 #include <net/netfilter/nf_conntrack_expect.h>
55 #include <net/netfilter/nf_conntrack_helper.h>
56 #include <net/netfilter/nf_conntrack_core.h>
57
58 #define NF_CONNTRACK_VERSION    "0.5.0"
59
60 #if 0
61 #define DEBUGP printk
62 #else
63 #define DEBUGP(format, args...)
64 #endif
65
66 DEFINE_RWLOCK(nf_conntrack_lock);
67 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
68
69 /* nf_conntrack_standalone needs this */
70 atomic_t nf_conntrack_count = ATOMIC_INIT(0);
71 EXPORT_SYMBOL_GPL(nf_conntrack_count);
72
73 void (*nf_conntrack_destroyed)(struct nf_conn *conntrack);
74 EXPORT_SYMBOL_GPL(nf_conntrack_destroyed);
75
76 unsigned int nf_conntrack_htable_size __read_mostly;
77 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
78
79 int nf_conntrack_max __read_mostly;
80 EXPORT_SYMBOL_GPL(nf_conntrack_max);
81
82 struct list_head *nf_conntrack_hash __read_mostly;
83 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
84
85 struct nf_conn nf_conntrack_untracked __read_mostly;
86 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
87
88 unsigned int nf_ct_log_invalid __read_mostly;
89 LIST_HEAD(unconfirmed);
90 static int nf_conntrack_vmalloc __read_mostly;
91
92 static unsigned int nf_conntrack_next_id;
93
94 DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
95 EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
96
97 /*
98  * This scheme offers various size of "struct nf_conn" dependent on
99  * features(helper, nat, ...)
100  */
101
102 #define NF_CT_FEATURES_NAMELEN  256
103 static struct {
104         /* name of slab cache. printed in /proc/slabinfo */
105         char *name;
106
107         /* size of slab cache */
108         size_t size;
109
110         /* slab cache pointer */
111         struct kmem_cache *cachep;
112
113         /* allocated slab cache + modules which uses this slab cache */
114         int use;
115
116 } nf_ct_cache[NF_CT_F_NUM];
117
118 /* protect members of nf_ct_cache except of "use" */
119 DEFINE_RWLOCK(nf_ct_cache_lock);
120
121 /* This avoids calling kmem_cache_create() with same name simultaneously */
122 static DEFINE_MUTEX(nf_ct_cache_mutex);
123
124 static int nf_conntrack_hash_rnd_initted;
125 static unsigned int nf_conntrack_hash_rnd;
126
127 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
128                                   unsigned int size, unsigned int rnd)
129 {
130         unsigned int a, b;
131         a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all),
132                   ((tuple->src.l3num) << 16) | tuple->dst.protonum);
133         b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all),
134                         (tuple->src.u.all << 16) | tuple->dst.u.all);
135
136         return jhash_2words(a, b, rnd) % size;
137 }
138
139 static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
140 {
141         return __hash_conntrack(tuple, nf_conntrack_htable_size,
142                                 nf_conntrack_hash_rnd);
143 }
144
145 int nf_conntrack_register_cache(u_int32_t features, const char *name,
146                                 size_t size)
147 {
148         int ret = 0;
149         char *cache_name;
150         struct kmem_cache *cachep;
151
152         DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n",
153                features, name, size);
154
155         if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) {
156                 DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n",
157                         features);
158                 return -EINVAL;
159         }
160
161         mutex_lock(&nf_ct_cache_mutex);
162
163         write_lock_bh(&nf_ct_cache_lock);
164         /* e.g: multiple helpers are loaded */
165         if (nf_ct_cache[features].use > 0) {
166                 DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
167                 if ((!strncmp(nf_ct_cache[features].name, name,
168                               NF_CT_FEATURES_NAMELEN))
169                     && nf_ct_cache[features].size == size) {
170                         DEBUGP("nf_conntrack_register_cache: reusing.\n");
171                         nf_ct_cache[features].use++;
172                         ret = 0;
173                 } else
174                         ret = -EBUSY;
175
176                 write_unlock_bh(&nf_ct_cache_lock);
177                 mutex_unlock(&nf_ct_cache_mutex);
178                 return ret;
179         }
180         write_unlock_bh(&nf_ct_cache_lock);
181
182         /*
183          * The memory space for name of slab cache must be alive until
184          * cache is destroyed.
185          */
186         cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC);
187         if (cache_name == NULL) {
188                 DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n");
189                 ret = -ENOMEM;
190                 goto out_up_mutex;
191         }
192
193         if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN)
194                                                 >= NF_CT_FEATURES_NAMELEN) {
195                 printk("nf_conntrack_register_cache: name too long\n");
196                 ret = -EINVAL;
197                 goto out_free_name;
198         }
199
200         cachep = kmem_cache_create(cache_name, size, 0, 0,
201                                    NULL, NULL);
202         if (!cachep) {
203                 printk("nf_conntrack_register_cache: Can't create slab cache "
204                        "for the features = 0x%x\n", features);
205                 ret = -ENOMEM;
206                 goto out_free_name;
207         }
208
209         write_lock_bh(&nf_ct_cache_lock);
210         nf_ct_cache[features].use = 1;
211         nf_ct_cache[features].size = size;
212         nf_ct_cache[features].cachep = cachep;
213         nf_ct_cache[features].name = cache_name;
214         write_unlock_bh(&nf_ct_cache_lock);
215
216         goto out_up_mutex;
217
218 out_free_name:
219         kfree(cache_name);
220 out_up_mutex:
221         mutex_unlock(&nf_ct_cache_mutex);
222         return ret;
223 }
224 EXPORT_SYMBOL_GPL(nf_conntrack_register_cache);
225
226 /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */
227 void nf_conntrack_unregister_cache(u_int32_t features)
228 {
229         struct kmem_cache *cachep;
230         char *name;
231
232         /*
233          * This assures that kmem_cache_create() isn't called before destroying
234          * slab cache.
235          */
236         DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features);
237         mutex_lock(&nf_ct_cache_mutex);
238
239         write_lock_bh(&nf_ct_cache_lock);
240         if (--nf_ct_cache[features].use > 0) {
241                 write_unlock_bh(&nf_ct_cache_lock);
242                 mutex_unlock(&nf_ct_cache_mutex);
243                 return;
244         }
245         cachep = nf_ct_cache[features].cachep;
246         name = nf_ct_cache[features].name;
247         nf_ct_cache[features].cachep = NULL;
248         nf_ct_cache[features].name = NULL;
249         nf_ct_cache[features].size = 0;
250         write_unlock_bh(&nf_ct_cache_lock);
251
252         synchronize_net();
253
254         kmem_cache_destroy(cachep);
255         kfree(name);
256
257         mutex_unlock(&nf_ct_cache_mutex);
258 }
259 EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache);
260
261 int
262 nf_ct_get_tuple(const struct sk_buff *skb,
263                 unsigned int nhoff,
264                 unsigned int dataoff,
265                 u_int16_t l3num,
266                 u_int8_t protonum,
267                 struct nf_conntrack_tuple *tuple,
268                 const struct nf_conntrack_l3proto *l3proto,
269                 const struct nf_conntrack_l4proto *l4proto)
270 {
271         NF_CT_TUPLE_U_BLANK(tuple);
272
273         tuple->src.l3num = l3num;
274         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
275                 return 0;
276
277         tuple->dst.protonum = protonum;
278         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
279
280         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
281 }
282 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
283
284 int
285 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
286                    const struct nf_conntrack_tuple *orig,
287                    const struct nf_conntrack_l3proto *l3proto,
288                    const struct nf_conntrack_l4proto *l4proto)
289 {
290         NF_CT_TUPLE_U_BLANK(inverse);
291
292         inverse->src.l3num = orig->src.l3num;
293         if (l3proto->invert_tuple(inverse, orig) == 0)
294                 return 0;
295
296         inverse->dst.dir = !orig->dst.dir;
297
298         inverse->dst.protonum = orig->dst.protonum;
299         return l4proto->invert_tuple(inverse, orig);
300 }
301 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
302
303 static void
304 clean_from_lists(struct nf_conn *ct)
305 {
306         DEBUGP("clean_from_lists(%p)\n", ct);
307         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
308         list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list);
309
310         /* Destroy all pending expectations */
311         nf_ct_remove_expectations(ct);
312 }
313
314 static void
315 destroy_conntrack(struct nf_conntrack *nfct)
316 {
317         struct nf_conn *ct = (struct nf_conn *)nfct;
318         struct nf_conn_help *help = nfct_help(ct);
319         struct nf_conntrack_l3proto *l3proto;
320         struct nf_conntrack_l4proto *l4proto;
321
322         DEBUGP("destroy_conntrack(%p)\n", ct);
323         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
324         NF_CT_ASSERT(!timer_pending(&ct->timeout));
325
326         nf_conntrack_event(IPCT_DESTROY, ct);
327         set_bit(IPS_DYING_BIT, &ct->status);
328
329         if (help && help->helper && help->helper->destroy)
330                 help->helper->destroy(ct);
331
332         /* To make sure we don't get any weird locking issues here:
333          * destroy_conntrack() MUST NOT be called with a write lock
334          * to nf_conntrack_lock!!! -HW */
335         l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num);
336         if (l3proto && l3proto->destroy)
337                 l3proto->destroy(ct);
338
339         l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
340         if (l4proto && l4proto->destroy)
341                 l4proto->destroy(ct);
342
343         if (nf_conntrack_destroyed)
344                 nf_conntrack_destroyed(ct);
345
346         write_lock_bh(&nf_conntrack_lock);
347         /* Expectations will have been removed in clean_from_lists,
348          * except TFTP can create an expectation on the first packet,
349          * before connection is in the list, so we need to clean here,
350          * too. */
351         nf_ct_remove_expectations(ct);
352
353         /* We overload first tuple to link into unconfirmed list. */
354         if (!nf_ct_is_confirmed(ct)) {
355                 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
356                 list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
357         }
358
359         NF_CT_STAT_INC(delete);
360         write_unlock_bh(&nf_conntrack_lock);
361
362         if (ct->master)
363                 nf_ct_put(ct->master);
364
365         DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
366         nf_conntrack_free(ct);
367 }
368
369 static void death_by_timeout(unsigned long ul_conntrack)
370 {
371         struct nf_conn *ct = (void *)ul_conntrack;
372
373         write_lock_bh(&nf_conntrack_lock);
374         /* Inside lock so preempt is disabled on module removal path.
375          * Otherwise we can get spurious warnings. */
376         NF_CT_STAT_INC(delete_list);
377         clean_from_lists(ct);
378         write_unlock_bh(&nf_conntrack_lock);
379         nf_ct_put(ct);
380 }
381
382 struct nf_conntrack_tuple_hash *
383 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
384                     const struct nf_conn *ignored_conntrack)
385 {
386         struct nf_conntrack_tuple_hash *h;
387         unsigned int hash = hash_conntrack(tuple);
388
389         list_for_each_entry(h, &nf_conntrack_hash[hash], list) {
390                 if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
391                     nf_ct_tuple_equal(tuple, &h->tuple)) {
392                         NF_CT_STAT_INC(found);
393                         return h;
394                 }
395                 NF_CT_STAT_INC(searched);
396         }
397
398         return NULL;
399 }
400 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
401
402 /* Find a connection corresponding to a tuple. */
403 struct nf_conntrack_tuple_hash *
404 nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple,
405                       const struct nf_conn *ignored_conntrack)
406 {
407         struct nf_conntrack_tuple_hash *h;
408
409         read_lock_bh(&nf_conntrack_lock);
410         h = __nf_conntrack_find(tuple, ignored_conntrack);
411         if (h)
412                 atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
413         read_unlock_bh(&nf_conntrack_lock);
414
415         return h;
416 }
417 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
418
419 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
420                                        unsigned int hash,
421                                        unsigned int repl_hash) 
422 {
423         ct->id = ++nf_conntrack_next_id;
424         list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list,
425                  &nf_conntrack_hash[hash]);
426         list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list,
427                  &nf_conntrack_hash[repl_hash]);
428 }
429
430 void nf_conntrack_hash_insert(struct nf_conn *ct)
431 {
432         unsigned int hash, repl_hash;
433
434         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
435         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
436
437         write_lock_bh(&nf_conntrack_lock);
438         __nf_conntrack_hash_insert(ct, hash, repl_hash);
439         write_unlock_bh(&nf_conntrack_lock);
440 }
441 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
442
443 /* Confirm a connection given skb; places it in hash table */
444 int
445 __nf_conntrack_confirm(struct sk_buff **pskb)
446 {
447         unsigned int hash, repl_hash;
448         struct nf_conntrack_tuple_hash *h;
449         struct nf_conn *ct;
450         struct nf_conn_help *help;
451         enum ip_conntrack_info ctinfo;
452
453         ct = nf_ct_get(*pskb, &ctinfo);
454
455         /* ipt_REJECT uses nf_conntrack_attach to attach related
456            ICMP/TCP RST packets in other direction.  Actual packet
457            which created connection will be IP_CT_NEW or for an
458            expected connection, IP_CT_RELATED. */
459         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
460                 return NF_ACCEPT;
461
462         hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
463         repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
464
465         /* We're not in hash table, and we refuse to set up related
466            connections for unconfirmed conns.  But packet copies and
467            REJECT will give spurious warnings here. */
468         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
469
470         /* No external references means noone else could have
471            confirmed us. */
472         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
473         DEBUGP("Confirming conntrack %p\n", ct);
474
475         write_lock_bh(&nf_conntrack_lock);
476
477         /* See if there's one in the list already, including reverse:
478            NAT could have grabbed it without realizing, since we're
479            not in the hash.  If there is, we lost race. */
480         list_for_each_entry(h, &nf_conntrack_hash[hash], list)
481                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
482                                       &h->tuple))
483                         goto out;
484         list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list)
485                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
486                                       &h->tuple))
487                         goto out;
488
489         /* Remove from unconfirmed list */
490         list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
491
492         __nf_conntrack_hash_insert(ct, hash, repl_hash);
493         /* Timer relative to confirmation time, not original
494            setting time, otherwise we'd get timer wrap in
495            weird delay cases. */
496         ct->timeout.expires += jiffies;
497         add_timer(&ct->timeout);
498         atomic_inc(&ct->ct_general.use);
499         set_bit(IPS_CONFIRMED_BIT, &ct->status);
500         NF_CT_STAT_INC(insert);
501         write_unlock_bh(&nf_conntrack_lock);
502         help = nfct_help(ct);
503         if (help && help->helper)
504                 nf_conntrack_event_cache(IPCT_HELPER, *pskb);
505 #ifdef CONFIG_NF_NAT_NEEDED
506         if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
507             test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
508                 nf_conntrack_event_cache(IPCT_NATINFO, *pskb);
509 #endif
510         nf_conntrack_event_cache(master_ct(ct) ?
511                                  IPCT_RELATED : IPCT_NEW, *pskb);
512         return NF_ACCEPT;
513
514 out:
515         NF_CT_STAT_INC(insert_failed);
516         write_unlock_bh(&nf_conntrack_lock);
517         return NF_DROP;
518 }
519 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
520
521 /* Returns true if a connection correspondings to the tuple (required
522    for NAT). */
523 int
524 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
525                          const struct nf_conn *ignored_conntrack)
526 {
527         struct nf_conntrack_tuple_hash *h;
528
529         read_lock_bh(&nf_conntrack_lock);
530         h = __nf_conntrack_find(tuple, ignored_conntrack);
531         read_unlock_bh(&nf_conntrack_lock);
532
533         return h != NULL;
534 }
535 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
536
537 /* There's a small race here where we may free a just-assured
538    connection.  Too bad: we're in trouble anyway. */
539 static int early_drop(struct list_head *chain)
540 {
541         /* Traverse backwards: gives us oldest, which is roughly LRU */
542         struct nf_conntrack_tuple_hash *h;
543         struct nf_conn *ct = NULL, *tmp;
544         int dropped = 0;
545
546         read_lock_bh(&nf_conntrack_lock);
547         list_for_each_entry_reverse(h, chain, list) {
548                 tmp = nf_ct_tuplehash_to_ctrack(h);
549                 if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) {
550                         ct = tmp;
551                         atomic_inc(&ct->ct_general.use);
552                         break;
553                 }
554         }
555         read_unlock_bh(&nf_conntrack_lock);
556
557         if (!ct)
558                 return dropped;
559
560         if (del_timer(&ct->timeout)) {
561                 death_by_timeout((unsigned long)ct);
562                 dropped = 1;
563                 NF_CT_STAT_INC(early_drop);
564         }
565         nf_ct_put(ct);
566         return dropped;
567 }
568
569 static struct nf_conn *
570 __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
571                      const struct nf_conntrack_tuple *repl,
572                      const struct nf_conntrack_l3proto *l3proto,
573                      u_int32_t features)
574 {
575         struct nf_conn *conntrack = NULL;
576         struct nf_conntrack_helper *helper;
577
578         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
579                 get_random_bytes(&nf_conntrack_hash_rnd, 4);
580                 nf_conntrack_hash_rnd_initted = 1;
581         }
582
583         /* We don't want any race condition at early drop stage */
584         atomic_inc(&nf_conntrack_count);
585
586         if (nf_conntrack_max
587             && atomic_read(&nf_conntrack_count) > nf_conntrack_max) {
588                 unsigned int hash = hash_conntrack(orig);
589                 /* Try dropping from this hash chain. */
590                 if (!early_drop(&nf_conntrack_hash[hash])) {
591                         atomic_dec(&nf_conntrack_count);
592                         if (net_ratelimit())
593                                 printk(KERN_WARNING
594                                        "nf_conntrack: table full, dropping"
595                                        " packet.\n");
596                         return ERR_PTR(-ENOMEM);
597                 }
598         }
599
600         /*  find features needed by this conntrack. */
601         features |= l3proto->get_features(orig);
602
603         /* FIXME: protect helper list per RCU */
604         read_lock_bh(&nf_conntrack_lock);
605         helper = __nf_ct_helper_find(repl);
606         /* NAT might want to assign a helper later */
607         if (helper || features & NF_CT_F_NAT)
608                 features |= NF_CT_F_HELP;
609         read_unlock_bh(&nf_conntrack_lock);
610
611         DEBUGP("nf_conntrack_alloc: features=0x%x\n", features);
612
613         read_lock_bh(&nf_ct_cache_lock);
614
615         if (unlikely(!nf_ct_cache[features].use)) {
616                 DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
617                         features);
618                 goto out;
619         }
620
621         conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC);
622         if (conntrack == NULL) {
623                 DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n");
624                 goto out;
625         }
626
627         memset(conntrack, 0, nf_ct_cache[features].size);
628         conntrack->features = features;
629         atomic_set(&conntrack->ct_general.use, 1);
630         conntrack->ct_general.destroy = destroy_conntrack;
631         conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
632         conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
633         /* Don't set timer yet: wait for confirmation */
634         init_timer(&conntrack->timeout);
635         conntrack->timeout.data = (unsigned long)conntrack;
636         conntrack->timeout.function = death_by_timeout;
637         read_unlock_bh(&nf_ct_cache_lock);
638
639         return conntrack;
640 out:
641         read_unlock_bh(&nf_ct_cache_lock);
642         atomic_dec(&nf_conntrack_count);
643         return conntrack;
644 }
645
646 struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
647                                    const struct nf_conntrack_tuple *repl)
648 {
649         struct nf_conntrack_l3proto *l3proto;
650
651         l3proto = __nf_ct_l3proto_find(orig->src.l3num);
652         return __nf_conntrack_alloc(orig, repl, l3proto, 0);
653 }
654 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
655
656 void nf_conntrack_free(struct nf_conn *conntrack)
657 {
658         u_int32_t features = conntrack->features;
659         NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM);
660         DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features,
661                conntrack);
662         kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
663         atomic_dec(&nf_conntrack_count);
664 }
665 EXPORT_SYMBOL_GPL(nf_conntrack_free);
666
667 /* Allocate a new conntrack: we return -ENOMEM if classification
668    failed due to stress.  Otherwise it really is unclassifiable. */
669 static struct nf_conntrack_tuple_hash *
670 init_conntrack(const struct nf_conntrack_tuple *tuple,
671                struct nf_conntrack_l3proto *l3proto,
672                struct nf_conntrack_l4proto *l4proto,
673                struct sk_buff *skb,
674                unsigned int dataoff)
675 {
676         struct nf_conn *conntrack;
677         struct nf_conntrack_tuple repl_tuple;
678         struct nf_conntrack_expect *exp;
679         u_int32_t features = 0;
680
681         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
682                 DEBUGP("Can't invert tuple.\n");
683                 return NULL;
684         }
685
686         read_lock_bh(&nf_conntrack_lock);
687         exp = __nf_conntrack_expect_find(tuple);
688         if (exp && exp->helper)
689                 features = NF_CT_F_HELP;
690         read_unlock_bh(&nf_conntrack_lock);
691
692         conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features);
693         if (conntrack == NULL || IS_ERR(conntrack)) {
694                 DEBUGP("Can't allocate conntrack.\n");
695                 return (struct nf_conntrack_tuple_hash *)conntrack;
696         }
697
698         if (!l4proto->new(conntrack, skb, dataoff)) {
699                 nf_conntrack_free(conntrack);
700                 DEBUGP("init conntrack: can't track with proto module\n");
701                 return NULL;
702         }
703
704         write_lock_bh(&nf_conntrack_lock);
705         exp = find_expectation(tuple);
706
707         if (exp) {
708                 DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
709                         conntrack, exp);
710                 /* Welcome, Mr. Bond.  We've been expecting you... */
711                 __set_bit(IPS_EXPECTED_BIT, &conntrack->status);
712                 conntrack->master = exp->master;
713                 if (exp->helper)
714                         nfct_help(conntrack)->helper = exp->helper;
715 #ifdef CONFIG_NF_CONNTRACK_MARK
716                 conntrack->mark = exp->master->mark;
717 #endif
718 #ifdef CONFIG_NF_CONNTRACK_SECMARK
719                 conntrack->secmark = exp->master->secmark;
720 #endif
721                 nf_conntrack_get(&conntrack->master->ct_general);
722                 NF_CT_STAT_INC(expect_new);
723         } else {
724                 struct nf_conn_help *help = nfct_help(conntrack);
725
726                 if (help)
727                         help->helper = __nf_ct_helper_find(&repl_tuple);
728                 NF_CT_STAT_INC(new);
729         }
730
731         /* Overload tuple linked list to put us in unconfirmed list. */
732         list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
733
734         write_unlock_bh(&nf_conntrack_lock);
735
736         if (exp) {
737                 if (exp->expectfn)
738                         exp->expectfn(conntrack, exp);
739                 nf_conntrack_expect_put(exp);
740         }
741
742         return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
743 }
744
745 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
746 static inline struct nf_conn *
747 resolve_normal_ct(struct sk_buff *skb,
748                   unsigned int dataoff,
749                   u_int16_t l3num,
750                   u_int8_t protonum,
751                   struct nf_conntrack_l3proto *l3proto,
752                   struct nf_conntrack_l4proto *l4proto,
753                   int *set_reply,
754                   enum ip_conntrack_info *ctinfo)
755 {
756         struct nf_conntrack_tuple tuple;
757         struct nf_conntrack_tuple_hash *h;
758         struct nf_conn *ct;
759
760         if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data),
761                              dataoff, l3num, protonum, &tuple, l3proto,
762                              l4proto)) {
763                 DEBUGP("resolve_normal_ct: Can't get tuple\n");
764                 return NULL;
765         }
766
767         /* look for tuple match */
768         h = nf_conntrack_find_get(&tuple, NULL);
769         if (!h) {
770                 h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff);
771                 if (!h)
772                         return NULL;
773                 if (IS_ERR(h))
774                         return (void *)h;
775         }
776         ct = nf_ct_tuplehash_to_ctrack(h);
777
778         /* It exists; we have (non-exclusive) reference. */
779         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
780                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
781                 /* Please set reply bit if this packet OK */
782                 *set_reply = 1;
783         } else {
784                 /* Once we've had two way comms, always ESTABLISHED. */
785                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
786                         DEBUGP("nf_conntrack_in: normal packet for %p\n", ct);
787                         *ctinfo = IP_CT_ESTABLISHED;
788                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
789                         DEBUGP("nf_conntrack_in: related packet for %p\n", ct);
790                         *ctinfo = IP_CT_RELATED;
791                 } else {
792                         DEBUGP("nf_conntrack_in: new packet for %p\n", ct);
793                         *ctinfo = IP_CT_NEW;
794                 }
795                 *set_reply = 0;
796         }
797         skb->nfct = &ct->ct_general;
798         skb->nfctinfo = *ctinfo;
799         return ct;
800 }
801
802 unsigned int
803 nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
804 {
805         struct nf_conn *ct;
806         enum ip_conntrack_info ctinfo;
807         struct nf_conntrack_l3proto *l3proto;
808         struct nf_conntrack_l4proto *l4proto;
809         unsigned int dataoff;
810         u_int8_t protonum;
811         int set_reply = 0;
812         int ret;
813
814         /* Previously seen (loopback or untracked)?  Ignore. */
815         if ((*pskb)->nfct) {
816                 NF_CT_STAT_INC(ignore);
817                 return NF_ACCEPT;
818         }
819
820         l3proto = __nf_ct_l3proto_find((u_int16_t)pf);
821         if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) {
822                 DEBUGP("not prepared to track yet or error occured\n");
823                 return -ret;
824         }
825
826         l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum);
827
828         /* It may be an special packet, error, unclean...
829          * inverse of the return code tells to the netfilter
830          * core what to do with the packet. */
831         if (l4proto->error != NULL &&
832             (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
833                 NF_CT_STAT_INC(error);
834                 NF_CT_STAT_INC(invalid);
835                 return -ret;
836         }
837
838         ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto,
839                                &set_reply, &ctinfo);
840         if (!ct) {
841                 /* Not valid part of a connection */
842                 NF_CT_STAT_INC(invalid);
843                 return NF_ACCEPT;
844         }
845
846         if (IS_ERR(ct)) {
847                 /* Too stressed to deal. */
848                 NF_CT_STAT_INC(drop);
849                 return NF_DROP;
850         }
851
852         NF_CT_ASSERT((*pskb)->nfct);
853
854         ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum);
855         if (ret < 0) {
856                 /* Invalid: inverse of the return code tells
857                  * the netfilter core what to do */
858                 DEBUGP("nf_conntrack_in: Can't track with proto module\n");
859                 nf_conntrack_put((*pskb)->nfct);
860                 (*pskb)->nfct = NULL;
861                 NF_CT_STAT_INC(invalid);
862                 return -ret;
863         }
864
865         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
866                 nf_conntrack_event_cache(IPCT_STATUS, *pskb);
867
868         return ret;
869 }
870 EXPORT_SYMBOL_GPL(nf_conntrack_in);
871
872 int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
873                          const struct nf_conntrack_tuple *orig)
874 {
875         return nf_ct_invert_tuple(inverse, orig,
876                                   __nf_ct_l3proto_find(orig->src.l3num),
877                                   __nf_ct_l4proto_find(orig->src.l3num,
878                                                      orig->dst.protonum));
879 }
880 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
881
882 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
883    implicitly racy: see __nf_conntrack_confirm */
884 void nf_conntrack_alter_reply(struct nf_conn *ct,
885                               const struct nf_conntrack_tuple *newreply)
886 {
887         struct nf_conn_help *help = nfct_help(ct);
888
889         write_lock_bh(&nf_conntrack_lock);
890         /* Should be unconfirmed, so not in hash table yet */
891         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
892
893         DEBUGP("Altering reply tuple of %p to ", ct);
894         NF_CT_DUMP_TUPLE(newreply);
895
896         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
897         if (!ct->master && help && help->expecting == 0)
898                 help->helper = __nf_ct_helper_find(newreply);
899         write_unlock_bh(&nf_conntrack_lock);
900 }
901 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
902
903 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
904 void __nf_ct_refresh_acct(struct nf_conn *ct,
905                           enum ip_conntrack_info ctinfo,
906                           const struct sk_buff *skb,
907                           unsigned long extra_jiffies,
908                           int do_acct)
909 {
910         int event = 0;
911
912         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
913         NF_CT_ASSERT(skb);
914
915         write_lock_bh(&nf_conntrack_lock);
916
917         /* Only update if this is not a fixed timeout */
918         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
919                 write_unlock_bh(&nf_conntrack_lock);
920                 return;
921         }
922
923         /* If not in hash table, timer will not be active yet */
924         if (!nf_ct_is_confirmed(ct)) {
925                 ct->timeout.expires = extra_jiffies;
926                 event = IPCT_REFRESH;
927         } else {
928                 unsigned long newtime = jiffies + extra_jiffies;
929
930                 /* Only update the timeout if the new timeout is at least
931                    HZ jiffies from the old timeout. Need del_timer for race
932                    avoidance (may already be dying). */
933                 if (newtime - ct->timeout.expires >= HZ
934                     && del_timer(&ct->timeout)) {
935                         ct->timeout.expires = newtime;
936                         add_timer(&ct->timeout);
937                         event = IPCT_REFRESH;
938                 }
939         }
940
941 #ifdef CONFIG_NF_CT_ACCT
942         if (do_acct) {
943                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
944                 ct->counters[CTINFO2DIR(ctinfo)].bytes +=
945                         skb->len - (unsigned int)(skb->nh.raw - skb->data);
946
947                 if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
948                     || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
949                         event |= IPCT_COUNTER_FILLING;
950         }
951 #endif
952
953         write_unlock_bh(&nf_conntrack_lock);
954
955         /* must be unlocked when calling event cache */
956         if (event)
957                 nf_conntrack_event_cache(event, skb);
958 }
959 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
960
961 #if defined(CONFIG_NF_CT_NETLINK) || \
962     defined(CONFIG_NF_CT_NETLINK_MODULE)
963
964 #include <linux/netfilter/nfnetlink.h>
965 #include <linux/netfilter/nfnetlink_conntrack.h>
966 #include <linux/mutex.h>
967
968
969 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
970  * in ip_conntrack_core, since we don't want the protocols to autoload
971  * or depend on ctnetlink */
972 int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
973                                const struct nf_conntrack_tuple *tuple)
974 {
975         NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
976                 &tuple->src.u.tcp.port);
977         NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
978                 &tuple->dst.u.tcp.port);
979         return 0;
980
981 nfattr_failure:
982         return -1;
983 }
984 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr);
985
986 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
987         [CTA_PROTO_SRC_PORT-1]  = sizeof(u_int16_t),
988         [CTA_PROTO_DST_PORT-1]  = sizeof(u_int16_t)
989 };
990
991 int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
992                                struct nf_conntrack_tuple *t)
993 {
994         if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
995                 return -EINVAL;
996
997         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
998                 return -EINVAL;
999
1000         t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
1001         t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
1002
1003         return 0;
1004 }
1005 EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple);
1006 #endif
1007
1008 /* Used by ipt_REJECT and ip6t_REJECT. */
1009 void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1010 {
1011         struct nf_conn *ct;
1012         enum ip_conntrack_info ctinfo;
1013
1014         /* This ICMP is in reverse direction to the packet which caused it */
1015         ct = nf_ct_get(skb, &ctinfo);
1016         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1017                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
1018         else
1019                 ctinfo = IP_CT_RELATED;
1020
1021         /* Attach to new skbuff, and increment count */
1022         nskb->nfct = &ct->ct_general;
1023         nskb->nfctinfo = ctinfo;
1024         nf_conntrack_get(nskb->nfct);
1025 }
1026 EXPORT_SYMBOL_GPL(__nf_conntrack_attach);
1027
1028 static inline int
1029 do_iter(const struct nf_conntrack_tuple_hash *i,
1030         int (*iter)(struct nf_conn *i, void *data),
1031         void *data)
1032 {
1033         return iter(nf_ct_tuplehash_to_ctrack(i), data);
1034 }
1035
1036 /* Bring out ya dead! */
1037 static struct nf_conn *
1038 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
1039                 void *data, unsigned int *bucket)
1040 {
1041         struct nf_conntrack_tuple_hash *h;
1042         struct nf_conn *ct;
1043
1044         write_lock_bh(&nf_conntrack_lock);
1045         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1046                 list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) {
1047                         ct = nf_ct_tuplehash_to_ctrack(h);
1048                         if (iter(ct, data))
1049                                 goto found;
1050                 }
1051         }
1052         list_for_each_entry(h, &unconfirmed, list) {
1053                 ct = nf_ct_tuplehash_to_ctrack(h);
1054                 if (iter(ct, data))
1055                         goto found;
1056         }
1057         write_unlock_bh(&nf_conntrack_lock);
1058         return NULL;
1059 found:
1060         atomic_inc(&ct->ct_general.use);
1061         write_unlock_bh(&nf_conntrack_lock);
1062         return ct;
1063 }
1064
1065 void
1066 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
1067 {
1068         struct nf_conn *ct;
1069         unsigned int bucket = 0;
1070
1071         while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
1072                 /* Time to push up daises... */
1073                 if (del_timer(&ct->timeout))
1074                         death_by_timeout((unsigned long)ct);
1075                 /* ... else the timer will get him soon. */
1076
1077                 nf_ct_put(ct);
1078         }
1079 }
1080 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1081
1082 static int kill_all(struct nf_conn *i, void *data)
1083 {
1084         return 1;
1085 }
1086
1087 static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size)
1088 {
1089         if (vmalloced)
1090                 vfree(hash);
1091         else
1092                 free_pages((unsigned long)hash, 
1093                            get_order(sizeof(struct list_head) * size));
1094 }
1095
1096 void nf_conntrack_flush(void)
1097 {
1098         nf_ct_iterate_cleanup(kill_all, NULL);
1099 }
1100 EXPORT_SYMBOL_GPL(nf_conntrack_flush);
1101
1102 /* Mishearing the voices in his head, our hero wonders how he's
1103    supposed to kill the mall. */
1104 void nf_conntrack_cleanup(void)
1105 {
1106         int i;
1107
1108         ip_ct_attach = NULL;
1109
1110         /* This makes sure all current packets have passed through
1111            netfilter framework.  Roll on, two-stage module
1112            delete... */
1113         synchronize_net();
1114
1115         nf_ct_event_cache_flush();
1116  i_see_dead_people:
1117         nf_conntrack_flush();
1118         if (atomic_read(&nf_conntrack_count) != 0) {
1119                 schedule();
1120                 goto i_see_dead_people;
1121         }
1122         /* wait until all references to nf_conntrack_untracked are dropped */
1123         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1124                 schedule();
1125
1126         for (i = 0; i < NF_CT_F_NUM; i++) {
1127                 if (nf_ct_cache[i].use == 0)
1128                         continue;
1129
1130                 NF_CT_ASSERT(nf_ct_cache[i].use == 1);
1131                 nf_ct_cache[i].use = 1;
1132                 nf_conntrack_unregister_cache(i);
1133         }
1134         kmem_cache_destroy(nf_conntrack_expect_cachep);
1135         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1136                             nf_conntrack_htable_size);
1137
1138         nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic);
1139
1140         /* free l3proto protocol tables */
1141         for (i = 0; i < PF_MAX; i++)
1142                 if (nf_ct_protos[i]) {
1143                         kfree(nf_ct_protos[i]);
1144                         nf_ct_protos[i] = NULL;
1145                 }
1146 }
1147
1148 static struct list_head *alloc_hashtable(int size, int *vmalloced)
1149 {
1150         struct list_head *hash;
1151         unsigned int i;
1152
1153         *vmalloced = 0; 
1154         hash = (void*)__get_free_pages(GFP_KERNEL, 
1155                                        get_order(sizeof(struct list_head)
1156                                                  * size));
1157         if (!hash) { 
1158                 *vmalloced = 1;
1159                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1160                 hash = vmalloc(sizeof(struct list_head) * size);
1161         }
1162
1163         if (hash)
1164                 for (i = 0; i < size; i++) 
1165                         INIT_LIST_HEAD(&hash[i]);
1166
1167         return hash;
1168 }
1169
1170 int set_hashsize(const char *val, struct kernel_param *kp)
1171 {
1172         int i, bucket, hashsize, vmalloced;
1173         int old_vmalloced, old_size;
1174         int rnd;
1175         struct list_head *hash, *old_hash;
1176         struct nf_conntrack_tuple_hash *h;
1177
1178         /* On boot, we can set this without any fancy locking. */
1179         if (!nf_conntrack_htable_size)
1180                 return param_set_uint(val, kp);
1181
1182         hashsize = simple_strtol(val, NULL, 0);
1183         if (!hashsize)
1184                 return -EINVAL;
1185
1186         hash = alloc_hashtable(hashsize, &vmalloced);
1187         if (!hash)
1188                 return -ENOMEM;
1189
1190         /* We have to rehahs for the new table anyway, so we also can
1191          * use a newrandom seed */
1192         get_random_bytes(&rnd, 4);
1193
1194         write_lock_bh(&nf_conntrack_lock);
1195         for (i = 0; i < nf_conntrack_htable_size; i++) {
1196                 while (!list_empty(&nf_conntrack_hash[i])) {
1197                         h = list_entry(nf_conntrack_hash[i].next,
1198                                        struct nf_conntrack_tuple_hash, list);
1199                         list_del(&h->list);
1200                         bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
1201                         list_add_tail(&h->list, &hash[bucket]);
1202                 }
1203         }
1204         old_size = nf_conntrack_htable_size;
1205         old_vmalloced = nf_conntrack_vmalloc;
1206         old_hash = nf_conntrack_hash;
1207
1208         nf_conntrack_htable_size = hashsize;
1209         nf_conntrack_vmalloc = vmalloced;
1210         nf_conntrack_hash = hash;
1211         nf_conntrack_hash_rnd = rnd;
1212         write_unlock_bh(&nf_conntrack_lock);
1213
1214         free_conntrack_hash(old_hash, old_vmalloced, old_size);
1215         return 0;
1216 }
1217
1218 module_param_call(hashsize, set_hashsize, param_get_uint,
1219                   &nf_conntrack_htable_size, 0600);
1220
1221 int __init nf_conntrack_init(void)
1222 {
1223         unsigned int i;
1224         int ret;
1225
1226         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1227          * machine has 256 buckets.  >= 1GB machines have 8192 buckets. */
1228         if (!nf_conntrack_htable_size) {
1229                 nf_conntrack_htable_size
1230                         = (((num_physpages << PAGE_SHIFT) / 16384)
1231                            / sizeof(struct list_head));
1232                 if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
1233                         nf_conntrack_htable_size = 8192;
1234                 if (nf_conntrack_htable_size < 16)
1235                         nf_conntrack_htable_size = 16;
1236         }
1237         nf_conntrack_max = 8 * nf_conntrack_htable_size;
1238
1239         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1240                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1241                nf_conntrack_max);
1242
1243         nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size,
1244                                             &nf_conntrack_vmalloc);
1245         if (!nf_conntrack_hash) {
1246                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1247                 goto err_out;
1248         }
1249
1250         ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic",
1251                                           sizeof(struct nf_conn));
1252         if (ret < 0) {
1253                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1254                 goto err_free_hash;
1255         }
1256
1257         nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect",
1258                                         sizeof(struct nf_conntrack_expect),
1259                                         0, 0, NULL, NULL);
1260         if (!nf_conntrack_expect_cachep) {
1261                 printk(KERN_ERR "Unable to create nf_expect slab cache\n");
1262                 goto err_free_conntrack_slab;
1263         }
1264
1265         ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic);
1266         if (ret < 0)
1267                 goto out_free_expect_slab;
1268
1269         /* Don't NEED lock here, but good form anyway. */
1270         write_lock_bh(&nf_conntrack_lock);
1271         for (i = 0; i < AF_MAX; i++)
1272                 nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic;
1273         write_unlock_bh(&nf_conntrack_lock);
1274
1275         /* For use by REJECT target */
1276         ip_ct_attach = __nf_conntrack_attach;
1277
1278         /* Set up fake conntrack:
1279             - to never be deleted, not in any hashes */
1280         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1281         /*  - and look it like as a confirmed connection */
1282         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1283
1284         return ret;
1285
1286 out_free_expect_slab:
1287         kmem_cache_destroy(nf_conntrack_expect_cachep);
1288 err_free_conntrack_slab:
1289         nf_conntrack_unregister_cache(NF_CT_F_BASIC);
1290 err_free_hash:
1291         free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
1292                             nf_conntrack_htable_size);
1293 err_out:
1294         return -ENOMEM;
1295 }