Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / net / netfilter / nf_conntrack_core.c
1 /* Connection state tracking for netfilter.  This is separated from,
2    but required by, the NAT layer; it can also be used by an iptables
3    extension. */
4
5 /* (C) 1999-2001 Paul `Rusty' Russell
6  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
7  * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 #include <linux/types.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/skbuff.h>
19 #include <linux/proc_fs.h>
20 #include <linux/vmalloc.h>
21 #include <linux/stddef.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/jhash.h>
25 #include <linux/err.h>
26 #include <linux/percpu.h>
27 #include <linux/moduleparam.h>
28 #include <linux/notifier.h>
29 #include <linux/kernel.h>
30 #include <linux/netdevice.h>
31 #include <linux/socket.h>
32 #include <linux/mm.h>
33 #include <linux/nsproxy.h>
34 #include <linux/rculist_nulls.h>
35
36 #include <net/netfilter/nf_conntrack.h>
37 #include <net/netfilter/nf_conntrack_l3proto.h>
38 #include <net/netfilter/nf_conntrack_l4proto.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_core.h>
42 #include <net/netfilter/nf_conntrack_extend.h>
43 #include <net/netfilter/nf_conntrack_acct.h>
44 #include <net/netfilter/nf_conntrack_ecache.h>
45 #include <net/netfilter/nf_conntrack_zones.h>
46 #include <net/netfilter/nf_nat.h>
47 #include <net/netfilter/nf_nat_core.h>
48
49 #define NF_CONNTRACK_VERSION    "0.5.0"
50
51 int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
52                                       enum nf_nat_manip_type manip,
53                                       const struct nlattr *attr) __read_mostly;
54 EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
55
56 DEFINE_SPINLOCK(nf_conntrack_lock);
57 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
58
59 unsigned int nf_conntrack_htable_size __read_mostly;
60 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
61
62 unsigned int nf_conntrack_max __read_mostly;
63 EXPORT_SYMBOL_GPL(nf_conntrack_max);
64
65 struct nf_conn nf_conntrack_untracked __read_mostly;
66 EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
67
68 static int nf_conntrack_hash_rnd_initted;
69 static unsigned int nf_conntrack_hash_rnd;
70
71 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
72                                   u16 zone, unsigned int size, unsigned int rnd)
73 {
74         unsigned int n;
75         u_int32_t h;
76
77         /* The direction must be ignored, so we hash everything up to the
78          * destination ports (which is a multiple of 4) and treat the last
79          * three bytes manually.
80          */
81         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
82         h = jhash2((u32 *)tuple, n,
83                    zone ^ rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
84                                  tuple->dst.protonum));
85
86         return ((u64)h * size) >> 32;
87 }
88
89 static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
90                                        const struct nf_conntrack_tuple *tuple)
91 {
92         return __hash_conntrack(tuple, zone, net->ct.htable_size,
93                                 nf_conntrack_hash_rnd);
94 }
95
96 bool
97 nf_ct_get_tuple(const struct sk_buff *skb,
98                 unsigned int nhoff,
99                 unsigned int dataoff,
100                 u_int16_t l3num,
101                 u_int8_t protonum,
102                 struct nf_conntrack_tuple *tuple,
103                 const struct nf_conntrack_l3proto *l3proto,
104                 const struct nf_conntrack_l4proto *l4proto)
105 {
106         memset(tuple, 0, sizeof(*tuple));
107
108         tuple->src.l3num = l3num;
109         if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
110                 return false;
111
112         tuple->dst.protonum = protonum;
113         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
114
115         return l4proto->pkt_to_tuple(skb, dataoff, tuple);
116 }
117 EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
118
119 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
120                        u_int16_t l3num, struct nf_conntrack_tuple *tuple)
121 {
122         struct nf_conntrack_l3proto *l3proto;
123         struct nf_conntrack_l4proto *l4proto;
124         unsigned int protoff;
125         u_int8_t protonum;
126         int ret;
127
128         rcu_read_lock();
129
130         l3proto = __nf_ct_l3proto_find(l3num);
131         ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
132         if (ret != NF_ACCEPT) {
133                 rcu_read_unlock();
134                 return false;
135         }
136
137         l4proto = __nf_ct_l4proto_find(l3num, protonum);
138
139         ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
140                               l3proto, l4proto);
141
142         rcu_read_unlock();
143         return ret;
144 }
145 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
146
147 bool
148 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
149                    const struct nf_conntrack_tuple *orig,
150                    const struct nf_conntrack_l3proto *l3proto,
151                    const struct nf_conntrack_l4proto *l4proto)
152 {
153         memset(inverse, 0, sizeof(*inverse));
154
155         inverse->src.l3num = orig->src.l3num;
156         if (l3proto->invert_tuple(inverse, orig) == 0)
157                 return false;
158
159         inverse->dst.dir = !orig->dst.dir;
160
161         inverse->dst.protonum = orig->dst.protonum;
162         return l4proto->invert_tuple(inverse, orig);
163 }
164 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
165
166 static void
167 clean_from_lists(struct nf_conn *ct)
168 {
169         pr_debug("clean_from_lists(%p)\n", ct);
170         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
171         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
172
173         /* Destroy all pending expectations */
174         nf_ct_remove_expectations(ct);
175 }
176
177 static void
178 destroy_conntrack(struct nf_conntrack *nfct)
179 {
180         struct nf_conn *ct = (struct nf_conn *)nfct;
181         struct net *net = nf_ct_net(ct);
182         struct nf_conntrack_l4proto *l4proto;
183
184         pr_debug("destroy_conntrack(%p)\n", ct);
185         NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
186         NF_CT_ASSERT(!timer_pending(&ct->timeout));
187
188         /* To make sure we don't get any weird locking issues here:
189          * destroy_conntrack() MUST NOT be called with a write lock
190          * to nf_conntrack_lock!!! -HW */
191         rcu_read_lock();
192         l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
193         if (l4proto && l4proto->destroy)
194                 l4proto->destroy(ct);
195
196         rcu_read_unlock();
197
198         spin_lock_bh(&nf_conntrack_lock);
199         /* Expectations will have been removed in clean_from_lists,
200          * except TFTP can create an expectation on the first packet,
201          * before connection is in the list, so we need to clean here,
202          * too. */
203         nf_ct_remove_expectations(ct);
204
205         /* We overload first tuple to link into unconfirmed list. */
206         if (!nf_ct_is_confirmed(ct)) {
207                 BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
208                 hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
209         }
210
211         NF_CT_STAT_INC(net, delete);
212         spin_unlock_bh(&nf_conntrack_lock);
213
214         if (ct->master)
215                 nf_ct_put(ct->master);
216
217         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
218         nf_conntrack_free(ct);
219 }
220
221 void nf_ct_delete_from_lists(struct nf_conn *ct)
222 {
223         struct net *net = nf_ct_net(ct);
224
225         nf_ct_helper_destroy(ct);
226         spin_lock_bh(&nf_conntrack_lock);
227         /* Inside lock so preempt is disabled on module removal path.
228          * Otherwise we can get spurious warnings. */
229         NF_CT_STAT_INC(net, delete_list);
230         clean_from_lists(ct);
231         spin_unlock_bh(&nf_conntrack_lock);
232 }
233 EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
234
235 static void death_by_event(unsigned long ul_conntrack)
236 {
237         struct nf_conn *ct = (void *)ul_conntrack;
238         struct net *net = nf_ct_net(ct);
239
240         if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
241                 /* bad luck, let's retry again */
242                 ct->timeout.expires = jiffies +
243                         (random32() % net->ct.sysctl_events_retry_timeout);
244                 add_timer(&ct->timeout);
245                 return;
246         }
247         /* we've got the event delivered, now it's dying */
248         set_bit(IPS_DYING_BIT, &ct->status);
249         spin_lock(&nf_conntrack_lock);
250         hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
251         spin_unlock(&nf_conntrack_lock);
252         nf_ct_put(ct);
253 }
254
255 void nf_ct_insert_dying_list(struct nf_conn *ct)
256 {
257         struct net *net = nf_ct_net(ct);
258
259         /* add this conntrack to the dying list */
260         spin_lock_bh(&nf_conntrack_lock);
261         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
262                              &net->ct.dying);
263         spin_unlock_bh(&nf_conntrack_lock);
264         /* set a new timer to retry event delivery */
265         setup_timer(&ct->timeout, death_by_event, (unsigned long)ct);
266         ct->timeout.expires = jiffies +
267                 (random32() % net->ct.sysctl_events_retry_timeout);
268         add_timer(&ct->timeout);
269 }
270 EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
271
272 static void death_by_timeout(unsigned long ul_conntrack)
273 {
274         struct nf_conn *ct = (void *)ul_conntrack;
275
276         if (!test_bit(IPS_DYING_BIT, &ct->status) &&
277             unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
278                 /* destroy event was not delivered */
279                 nf_ct_delete_from_lists(ct);
280                 nf_ct_insert_dying_list(ct);
281                 return;
282         }
283         set_bit(IPS_DYING_BIT, &ct->status);
284         nf_ct_delete_from_lists(ct);
285         nf_ct_put(ct);
286 }
287
288 /*
289  * Warning :
290  * - Caller must take a reference on returned object
291  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
292  * OR
293  * - Caller must lock nf_conntrack_lock before calling this function
294  */
295 struct nf_conntrack_tuple_hash *
296 __nf_conntrack_find(struct net *net, u16 zone,
297                     const struct nf_conntrack_tuple *tuple)
298 {
299         struct nf_conntrack_tuple_hash *h;
300         struct hlist_nulls_node *n;
301         unsigned int hash = hash_conntrack(net, zone, tuple);
302
303         /* Disable BHs the entire time since we normally need to disable them
304          * at least once for the stats anyway.
305          */
306         local_bh_disable();
307 begin:
308         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
309                 if (nf_ct_tuple_equal(tuple, &h->tuple) &&
310                     nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
311                         NF_CT_STAT_INC(net, found);
312                         local_bh_enable();
313                         return h;
314                 }
315                 NF_CT_STAT_INC(net, searched);
316         }
317         /*
318          * if the nulls value we got at the end of this lookup is
319          * not the expected one, we must restart lookup.
320          * We probably met an item that was moved to another chain.
321          */
322         if (get_nulls_value(n) != hash)
323                 goto begin;
324         local_bh_enable();
325
326         return NULL;
327 }
328 EXPORT_SYMBOL_GPL(__nf_conntrack_find);
329
330 /* Find a connection corresponding to a tuple. */
331 struct nf_conntrack_tuple_hash *
332 nf_conntrack_find_get(struct net *net, u16 zone,
333                       const struct nf_conntrack_tuple *tuple)
334 {
335         struct nf_conntrack_tuple_hash *h;
336         struct nf_conn *ct;
337
338         rcu_read_lock();
339 begin:
340         h = __nf_conntrack_find(net, zone, tuple);
341         if (h) {
342                 ct = nf_ct_tuplehash_to_ctrack(h);
343                 if (unlikely(nf_ct_is_dying(ct) ||
344                              !atomic_inc_not_zero(&ct->ct_general.use)))
345                         h = NULL;
346                 else {
347                         if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
348                                      nf_ct_zone(ct) != zone)) {
349                                 nf_ct_put(ct);
350                                 goto begin;
351                         }
352                 }
353         }
354         rcu_read_unlock();
355
356         return h;
357 }
358 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
359
360 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
361                                        unsigned int hash,
362                                        unsigned int repl_hash)
363 {
364         struct net *net = nf_ct_net(ct);
365
366         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
367                            &net->ct.hash[hash]);
368         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
369                            &net->ct.hash[repl_hash]);
370 }
371
372 void nf_conntrack_hash_insert(struct nf_conn *ct)
373 {
374         struct net *net = nf_ct_net(ct);
375         unsigned int hash, repl_hash;
376         u16 zone;
377
378         zone = nf_ct_zone(ct);
379         hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
380         repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
381
382         __nf_conntrack_hash_insert(ct, hash, repl_hash);
383 }
384 EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
385
386 /* Confirm a connection given skb; places it in hash table */
387 int
388 __nf_conntrack_confirm(struct sk_buff *skb)
389 {
390         unsigned int hash, repl_hash;
391         struct nf_conntrack_tuple_hash *h;
392         struct nf_conn *ct;
393         struct nf_conn_help *help;
394         struct hlist_nulls_node *n;
395         enum ip_conntrack_info ctinfo;
396         struct net *net;
397         u16 zone;
398
399         ct = nf_ct_get(skb, &ctinfo);
400         net = nf_ct_net(ct);
401
402         /* ipt_REJECT uses nf_conntrack_attach to attach related
403            ICMP/TCP RST packets in other direction.  Actual packet
404            which created connection will be IP_CT_NEW or for an
405            expected connection, IP_CT_RELATED. */
406         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
407                 return NF_ACCEPT;
408
409         zone = nf_ct_zone(ct);
410         hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
411         repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
412
413         /* We're not in hash table, and we refuse to set up related
414            connections for unconfirmed conns.  But packet copies and
415            REJECT will give spurious warnings here. */
416         /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
417
418         /* No external references means noone else could have
419            confirmed us. */
420         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
421         pr_debug("Confirming conntrack %p\n", ct);
422
423         spin_lock_bh(&nf_conntrack_lock);
424
425         /* See if there's one in the list already, including reverse:
426            NAT could have grabbed it without realizing, since we're
427            not in the hash.  If there is, we lost race. */
428         hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
429                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
430                                       &h->tuple) &&
431                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
432                         goto out;
433         hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
434                 if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
435                                       &h->tuple) &&
436                     zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
437                         goto out;
438
439         /* Remove from unconfirmed list */
440         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
441
442         /* Timer relative to confirmation time, not original
443            setting time, otherwise we'd get timer wrap in
444            weird delay cases. */
445         ct->timeout.expires += jiffies;
446         add_timer(&ct->timeout);
447         atomic_inc(&ct->ct_general.use);
448         set_bit(IPS_CONFIRMED_BIT, &ct->status);
449
450         /* Since the lookup is lockless, hash insertion must be done after
451          * starting the timer and setting the CONFIRMED bit. The RCU barriers
452          * guarantee that no other CPU can find the conntrack before the above
453          * stores are visible.
454          */
455         __nf_conntrack_hash_insert(ct, hash, repl_hash);
456         NF_CT_STAT_INC(net, insert);
457         spin_unlock_bh(&nf_conntrack_lock);
458
459         help = nfct_help(ct);
460         if (help && help->helper)
461                 nf_conntrack_event_cache(IPCT_HELPER, ct);
462
463         nf_conntrack_event_cache(master_ct(ct) ?
464                                  IPCT_RELATED : IPCT_NEW, ct);
465         return NF_ACCEPT;
466
467 out:
468         NF_CT_STAT_INC(net, insert_failed);
469         spin_unlock_bh(&nf_conntrack_lock);
470         return NF_DROP;
471 }
472 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
473
474 /* Returns true if a connection correspondings to the tuple (required
475    for NAT). */
476 int
477 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
478                          const struct nf_conn *ignored_conntrack)
479 {
480         struct net *net = nf_ct_net(ignored_conntrack);
481         struct nf_conntrack_tuple_hash *h;
482         struct hlist_nulls_node *n;
483         struct nf_conn *ct;
484         u16 zone = nf_ct_zone(ignored_conntrack);
485         unsigned int hash = hash_conntrack(net, zone, tuple);
486
487         /* Disable BHs the entire time since we need to disable them at
488          * least once for the stats anyway.
489          */
490         rcu_read_lock_bh();
491         hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
492                 ct = nf_ct_tuplehash_to_ctrack(h);
493                 if (ct != ignored_conntrack &&
494                     nf_ct_tuple_equal(tuple, &h->tuple) &&
495                     nf_ct_zone(ct) == zone) {
496                         NF_CT_STAT_INC(net, found);
497                         rcu_read_unlock_bh();
498                         return 1;
499                 }
500                 NF_CT_STAT_INC(net, searched);
501         }
502         rcu_read_unlock_bh();
503
504         return 0;
505 }
506 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
507
508 #define NF_CT_EVICTION_RANGE    8
509
510 /* There's a small race here where we may free a just-assured
511    connection.  Too bad: we're in trouble anyway. */
512 static noinline int early_drop(struct net *net, unsigned int hash)
513 {
514         /* Use oldest entry, which is roughly LRU */
515         struct nf_conntrack_tuple_hash *h;
516         struct nf_conn *ct = NULL, *tmp;
517         struct hlist_nulls_node *n;
518         unsigned int i, cnt = 0;
519         int dropped = 0;
520
521         rcu_read_lock();
522         for (i = 0; i < net->ct.htable_size; i++) {
523                 hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
524                                          hnnode) {
525                         tmp = nf_ct_tuplehash_to_ctrack(h);
526                         if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
527                                 ct = tmp;
528                         cnt++;
529                 }
530
531                 if (ct != NULL) {
532                         if (likely(!nf_ct_is_dying(ct) &&
533                                    atomic_inc_not_zero(&ct->ct_general.use)))
534                                 break;
535                         else
536                                 ct = NULL;
537                 }
538
539                 if (cnt >= NF_CT_EVICTION_RANGE)
540                         break;
541
542                 hash = (hash + 1) % net->ct.htable_size;
543         }
544         rcu_read_unlock();
545
546         if (!ct)
547                 return dropped;
548
549         if (del_timer(&ct->timeout)) {
550                 death_by_timeout((unsigned long)ct);
551                 dropped = 1;
552                 NF_CT_STAT_INC_ATOMIC(net, early_drop);
553         }
554         nf_ct_put(ct);
555         return dropped;
556 }
557
558 struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
559                                    const struct nf_conntrack_tuple *orig,
560                                    const struct nf_conntrack_tuple *repl,
561                                    gfp_t gfp)
562 {
563         struct nf_conn *ct;
564
565         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
566                 get_random_bytes(&nf_conntrack_hash_rnd,
567                                 sizeof(nf_conntrack_hash_rnd));
568                 nf_conntrack_hash_rnd_initted = 1;
569         }
570
571         /* We don't want any race condition at early drop stage */
572         atomic_inc(&net->ct.count);
573
574         if (nf_conntrack_max &&
575             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
576                 unsigned int hash = hash_conntrack(net, zone, orig);
577                 if (!early_drop(net, hash)) {
578                         atomic_dec(&net->ct.count);
579                         if (net_ratelimit())
580                                 printk(KERN_WARNING
581                                        "nf_conntrack: table full, dropping"
582                                        " packet.\n");
583                         return ERR_PTR(-ENOMEM);
584                 }
585         }
586
587         /*
588          * Do not use kmem_cache_zalloc(), as this cache uses
589          * SLAB_DESTROY_BY_RCU.
590          */
591         ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
592         if (ct == NULL) {
593                 pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n");
594                 atomic_dec(&net->ct.count);
595                 return ERR_PTR(-ENOMEM);
596         }
597         /*
598          * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
599          * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
600          */
601         memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
602                sizeof(*ct) - offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
603         spin_lock_init(&ct->lock);
604         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
605         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
606         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
607         ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev = NULL;
608         /* Don't set timer yet: wait for confirmation */
609         setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
610 #ifdef CONFIG_NET_NS
611         ct->ct_net = net;
612 #endif
613 #ifdef CONFIG_NF_CONNTRACK_ZONES
614         if (zone) {
615                 struct nf_conntrack_zone *nf_ct_zone;
616
617                 nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
618                 if (!nf_ct_zone)
619                         goto out_free;
620                 nf_ct_zone->id = zone;
621         }
622 #endif
623         /*
624          * changes to lookup keys must be done before setting refcnt to 1
625          */
626         smp_wmb();
627         atomic_set(&ct->ct_general.use, 1);
628         return ct;
629
630 #ifdef CONFIG_NF_CONNTRACK_ZONES
631 out_free:
632         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
633         return ERR_PTR(-ENOMEM);
634 #endif
635 }
636 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
637
638 void nf_conntrack_free(struct nf_conn *ct)
639 {
640         struct net *net = nf_ct_net(ct);
641
642         nf_ct_ext_destroy(ct);
643         atomic_dec(&net->ct.count);
644         nf_ct_ext_free(ct);
645         kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
646 }
647 EXPORT_SYMBOL_GPL(nf_conntrack_free);
648
649 /* Allocate a new conntrack: we return -ENOMEM if classification
650    failed due to stress.  Otherwise it really is unclassifiable. */
651 static struct nf_conntrack_tuple_hash *
652 init_conntrack(struct net *net, struct nf_conn *tmpl,
653                const struct nf_conntrack_tuple *tuple,
654                struct nf_conntrack_l3proto *l3proto,
655                struct nf_conntrack_l4proto *l4proto,
656                struct sk_buff *skb,
657                unsigned int dataoff)
658 {
659         struct nf_conn *ct;
660         struct nf_conn_help *help;
661         struct nf_conntrack_tuple repl_tuple;
662         struct nf_conntrack_ecache *ecache;
663         struct nf_conntrack_expect *exp;
664         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
665
666         if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
667                 pr_debug("Can't invert tuple.\n");
668                 return NULL;
669         }
670
671         ct = nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC);
672         if (IS_ERR(ct)) {
673                 pr_debug("Can't allocate conntrack.\n");
674                 return (struct nf_conntrack_tuple_hash *)ct;
675         }
676
677         if (!l4proto->new(ct, skb, dataoff)) {
678                 nf_conntrack_free(ct);
679                 pr_debug("init conntrack: can't track with proto module\n");
680                 return NULL;
681         }
682
683         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
684
685         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
686         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
687                                  ecache ? ecache->expmask : 0,
688                              GFP_ATOMIC);
689
690         spin_lock_bh(&nf_conntrack_lock);
691         exp = nf_ct_find_expectation(net, zone, tuple);
692         if (exp) {
693                 pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
694                          ct, exp);
695                 /* Welcome, Mr. Bond.  We've been expecting you... */
696                 __set_bit(IPS_EXPECTED_BIT, &ct->status);
697                 ct->master = exp->master;
698                 if (exp->helper) {
699                         help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
700                         if (help)
701                                 rcu_assign_pointer(help->helper, exp->helper);
702                 }
703
704 #ifdef CONFIG_NF_CONNTRACK_MARK
705                 ct->mark = exp->master->mark;
706 #endif
707 #ifdef CONFIG_NF_CONNTRACK_SECMARK
708                 ct->secmark = exp->master->secmark;
709 #endif
710                 nf_conntrack_get(&ct->master->ct_general);
711                 NF_CT_STAT_INC(net, expect_new);
712         } else {
713                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
714                 NF_CT_STAT_INC(net, new);
715         }
716
717         /* Overload tuple linked list to put us in unconfirmed list. */
718         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
719                        &net->ct.unconfirmed);
720
721         spin_unlock_bh(&nf_conntrack_lock);
722
723         if (exp) {
724                 if (exp->expectfn)
725                         exp->expectfn(ct, exp);
726                 nf_ct_expect_put(exp);
727         }
728
729         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
730 }
731
732 /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
733 static inline struct nf_conn *
734 resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
735                   struct sk_buff *skb,
736                   unsigned int dataoff,
737                   u_int16_t l3num,
738                   u_int8_t protonum,
739                   struct nf_conntrack_l3proto *l3proto,
740                   struct nf_conntrack_l4proto *l4proto,
741                   int *set_reply,
742                   enum ip_conntrack_info *ctinfo)
743 {
744         struct nf_conntrack_tuple tuple;
745         struct nf_conntrack_tuple_hash *h;
746         struct nf_conn *ct;
747         u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
748
749         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
750                              dataoff, l3num, protonum, &tuple, l3proto,
751                              l4proto)) {
752                 pr_debug("resolve_normal_ct: Can't get tuple\n");
753                 return NULL;
754         }
755
756         /* look for tuple match */
757         h = nf_conntrack_find_get(net, zone, &tuple);
758         if (!h) {
759                 h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
760                                    skb, dataoff);
761                 if (!h)
762                         return NULL;
763                 if (IS_ERR(h))
764                         return (void *)h;
765         }
766         ct = nf_ct_tuplehash_to_ctrack(h);
767
768         /* It exists; we have (non-exclusive) reference. */
769         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
770                 *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY;
771                 /* Please set reply bit if this packet OK */
772                 *set_reply = 1;
773         } else {
774                 /* Once we've had two way comms, always ESTABLISHED. */
775                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
776                         pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
777                         *ctinfo = IP_CT_ESTABLISHED;
778                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
779                         pr_debug("nf_conntrack_in: related packet for %p\n",
780                                  ct);
781                         *ctinfo = IP_CT_RELATED;
782                 } else {
783                         pr_debug("nf_conntrack_in: new packet for %p\n", ct);
784                         *ctinfo = IP_CT_NEW;
785                 }
786                 *set_reply = 0;
787         }
788         skb->nfct = &ct->ct_general;
789         skb->nfctinfo = *ctinfo;
790         return ct;
791 }
792
793 unsigned int
794 nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
795                 struct sk_buff *skb)
796 {
797         struct nf_conn *ct, *tmpl = NULL;
798         enum ip_conntrack_info ctinfo;
799         struct nf_conntrack_l3proto *l3proto;
800         struct nf_conntrack_l4proto *l4proto;
801         unsigned int dataoff;
802         u_int8_t protonum;
803         int set_reply = 0;
804         int ret;
805
806         if (skb->nfct) {
807                 /* Previously seen (loopback or untracked)?  Ignore. */
808                 tmpl = (struct nf_conn *)skb->nfct;
809                 if (!nf_ct_is_template(tmpl)) {
810                         NF_CT_STAT_INC_ATOMIC(net, ignore);
811                         return NF_ACCEPT;
812                 }
813                 skb->nfct = NULL;
814         }
815
816         /* rcu_read_lock()ed by nf_hook_slow */
817         l3proto = __nf_ct_l3proto_find(pf);
818         ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
819                                    &dataoff, &protonum);
820         if (ret <= 0) {
821                 pr_debug("not prepared to track yet or error occured\n");
822                 NF_CT_STAT_INC_ATOMIC(net, error);
823                 NF_CT_STAT_INC_ATOMIC(net, invalid);
824                 ret = -ret;
825                 goto out;
826         }
827
828         l4proto = __nf_ct_l4proto_find(pf, protonum);
829
830         /* It may be an special packet, error, unclean...
831          * inverse of the return code tells to the netfilter
832          * core what to do with the packet. */
833         if (l4proto->error != NULL) {
834                 ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo,
835                                      pf, hooknum);
836                 if (ret <= 0) {
837                         NF_CT_STAT_INC_ATOMIC(net, error);
838                         NF_CT_STAT_INC_ATOMIC(net, invalid);
839                         ret = -ret;
840                         goto out;
841                 }
842         }
843
844         ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
845                                l3proto, l4proto, &set_reply, &ctinfo);
846         if (!ct) {
847                 /* Not valid part of a connection */
848                 NF_CT_STAT_INC_ATOMIC(net, invalid);
849                 ret = NF_ACCEPT;
850                 goto out;
851         }
852
853         if (IS_ERR(ct)) {
854                 /* Too stressed to deal. */
855                 NF_CT_STAT_INC_ATOMIC(net, drop);
856                 ret = NF_DROP;
857                 goto out;
858         }
859
860         NF_CT_ASSERT(skb->nfct);
861
862         ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
863         if (ret <= 0) {
864                 /* Invalid: inverse of the return code tells
865                  * the netfilter core what to do */
866                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
867                 nf_conntrack_put(skb->nfct);
868                 skb->nfct = NULL;
869                 NF_CT_STAT_INC_ATOMIC(net, invalid);
870                 if (ret == -NF_DROP)
871                         NF_CT_STAT_INC_ATOMIC(net, drop);
872                 ret = -ret;
873                 goto out;
874         }
875
876         if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
877                 nf_conntrack_event_cache(IPCT_REPLY, ct);
878 out:
879         if (tmpl)
880                 nf_ct_put(tmpl);
881
882         return ret;
883 }
884 EXPORT_SYMBOL_GPL(nf_conntrack_in);
885
886 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
887                           const struct nf_conntrack_tuple *orig)
888 {
889         bool ret;
890
891         rcu_read_lock();
892         ret = nf_ct_invert_tuple(inverse, orig,
893                                  __nf_ct_l3proto_find(orig->src.l3num),
894                                  __nf_ct_l4proto_find(orig->src.l3num,
895                                                       orig->dst.protonum));
896         rcu_read_unlock();
897         return ret;
898 }
899 EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
900
901 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
902    implicitly racy: see __nf_conntrack_confirm */
903 void nf_conntrack_alter_reply(struct nf_conn *ct,
904                               const struct nf_conntrack_tuple *newreply)
905 {
906         struct nf_conn_help *help = nfct_help(ct);
907
908         /* Should be unconfirmed, so not in hash table yet */
909         NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
910
911         pr_debug("Altering reply tuple of %p to ", ct);
912         nf_ct_dump_tuple(newreply);
913
914         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
915         if (ct->master || (help && !hlist_empty(&help->expectations)))
916                 return;
917
918         rcu_read_lock();
919         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
920         rcu_read_unlock();
921 }
922 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
923
924 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
925 void __nf_ct_refresh_acct(struct nf_conn *ct,
926                           enum ip_conntrack_info ctinfo,
927                           const struct sk_buff *skb,
928                           unsigned long extra_jiffies,
929                           int do_acct)
930 {
931         NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
932         NF_CT_ASSERT(skb);
933
934         /* Only update if this is not a fixed timeout */
935         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
936                 goto acct;
937
938         /* If not in hash table, timer will not be active yet */
939         if (!nf_ct_is_confirmed(ct)) {
940                 ct->timeout.expires = extra_jiffies;
941         } else {
942                 unsigned long newtime = jiffies + extra_jiffies;
943
944                 /* Only update the timeout if the new timeout is at least
945                    HZ jiffies from the old timeout. Need del_timer for race
946                    avoidance (may already be dying). */
947                 if (newtime - ct->timeout.expires >= HZ)
948                         mod_timer_pending(&ct->timeout, newtime);
949         }
950
951 acct:
952         if (do_acct) {
953                 struct nf_conn_counter *acct;
954
955                 acct = nf_conn_acct_find(ct);
956                 if (acct) {
957                         spin_lock_bh(&ct->lock);
958                         acct[CTINFO2DIR(ctinfo)].packets++;
959                         acct[CTINFO2DIR(ctinfo)].bytes +=
960                                 skb->len - skb_network_offset(skb);
961                         spin_unlock_bh(&ct->lock);
962                 }
963         }
964 }
965 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
966
967 bool __nf_ct_kill_acct(struct nf_conn *ct,
968                        enum ip_conntrack_info ctinfo,
969                        const struct sk_buff *skb,
970                        int do_acct)
971 {
972         if (do_acct) {
973                 struct nf_conn_counter *acct;
974
975                 acct = nf_conn_acct_find(ct);
976                 if (acct) {
977                         spin_lock_bh(&ct->lock);
978                         acct[CTINFO2DIR(ctinfo)].packets++;
979                         acct[CTINFO2DIR(ctinfo)].bytes +=
980                                 skb->len - skb_network_offset(skb);
981                         spin_unlock_bh(&ct->lock);
982                 }
983         }
984
985         if (del_timer(&ct->timeout)) {
986                 ct->timeout.function((unsigned long)ct);
987                 return true;
988         }
989         return false;
990 }
991 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
992
993 #ifdef CONFIG_NF_CONNTRACK_ZONES
994 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
995         .len    = sizeof(struct nf_conntrack_zone),
996         .align  = __alignof__(struct nf_conntrack_zone),
997         .id     = NF_CT_EXT_ZONE,
998 };
999 #endif
1000
1001 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1002
1003 #include <linux/netfilter/nfnetlink.h>
1004 #include <linux/netfilter/nfnetlink_conntrack.h>
1005 #include <linux/mutex.h>
1006
1007 /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
1008  * in ip_conntrack_core, since we don't want the protocols to autoload
1009  * or depend on ctnetlink */
1010 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1011                                const struct nf_conntrack_tuple *tuple)
1012 {
1013         NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
1014         NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
1015         return 0;
1016
1017 nla_put_failure:
1018         return -1;
1019 }
1020 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1021
1022 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1023         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1024         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1025 };
1026 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1027
1028 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1029                                struct nf_conntrack_tuple *t)
1030 {
1031         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1032                 return -EINVAL;
1033
1034         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1035         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1036
1037         return 0;
1038 }
1039 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1040
1041 int nf_ct_port_nlattr_tuple_size(void)
1042 {
1043         return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1044 }
1045 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1046 #endif
1047
1048 /* Used by ipt_REJECT and ip6t_REJECT. */
1049 static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
1050 {
1051         struct nf_conn *ct;
1052         enum ip_conntrack_info ctinfo;
1053
1054         /* This ICMP is in reverse direction to the packet which caused it */
1055         ct = nf_ct_get(skb, &ctinfo);
1056         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1057                 ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
1058         else
1059                 ctinfo = IP_CT_RELATED;
1060
1061         /* Attach to new skbuff, and increment count */
1062         nskb->nfct = &ct->ct_general;
1063         nskb->nfctinfo = ctinfo;
1064         nf_conntrack_get(nskb->nfct);
1065 }
1066
1067 /* Bring out ya dead! */
1068 static struct nf_conn *
1069 get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
1070                 void *data, unsigned int *bucket)
1071 {
1072         struct nf_conntrack_tuple_hash *h;
1073         struct nf_conn *ct;
1074         struct hlist_nulls_node *n;
1075
1076         spin_lock_bh(&nf_conntrack_lock);
1077         for (; *bucket < net->ct.htable_size; (*bucket)++) {
1078                 hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
1079                         ct = nf_ct_tuplehash_to_ctrack(h);
1080                         if (iter(ct, data))
1081                                 goto found;
1082                 }
1083         }
1084         hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
1085                 ct = nf_ct_tuplehash_to_ctrack(h);
1086                 if (iter(ct, data))
1087                         set_bit(IPS_DYING_BIT, &ct->status);
1088         }
1089         spin_unlock_bh(&nf_conntrack_lock);
1090         return NULL;
1091 found:
1092         atomic_inc(&ct->ct_general.use);
1093         spin_unlock_bh(&nf_conntrack_lock);
1094         return ct;
1095 }
1096
1097 void nf_ct_iterate_cleanup(struct net *net,
1098                            int (*iter)(struct nf_conn *i, void *data),
1099                            void *data)
1100 {
1101         struct nf_conn *ct;
1102         unsigned int bucket = 0;
1103
1104         while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
1105                 /* Time to push up daises... */
1106                 if (del_timer(&ct->timeout))
1107                         death_by_timeout((unsigned long)ct);
1108                 /* ... else the timer will get him soon. */
1109
1110                 nf_ct_put(ct);
1111         }
1112 }
1113 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
1114
1115 struct __nf_ct_flush_report {
1116         u32 pid;
1117         int report;
1118 };
1119
1120 static int kill_report(struct nf_conn *i, void *data)
1121 {
1122         struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
1123
1124         /* If we fail to deliver the event, death_by_timeout() will retry */
1125         if (nf_conntrack_event_report(IPCT_DESTROY, i,
1126                                       fr->pid, fr->report) < 0)
1127                 return 1;
1128
1129         /* Avoid the delivery of the destroy event in death_by_timeout(). */
1130         set_bit(IPS_DYING_BIT, &i->status);
1131         return 1;
1132 }
1133
1134 static int kill_all(struct nf_conn *i, void *data)
1135 {
1136         return 1;
1137 }
1138
1139 void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size)
1140 {
1141         if (vmalloced)
1142                 vfree(hash);
1143         else
1144                 free_pages((unsigned long)hash,
1145                            get_order(sizeof(struct hlist_head) * size));
1146 }
1147 EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
1148
1149 void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
1150 {
1151         struct __nf_ct_flush_report fr = {
1152                 .pid    = pid,
1153                 .report = report,
1154         };
1155         nf_ct_iterate_cleanup(net, kill_report, &fr);
1156 }
1157 EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
1158
1159 static void nf_ct_release_dying_list(struct net *net)
1160 {
1161         struct nf_conntrack_tuple_hash *h;
1162         struct nf_conn *ct;
1163         struct hlist_nulls_node *n;
1164
1165         spin_lock_bh(&nf_conntrack_lock);
1166         hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
1167                 ct = nf_ct_tuplehash_to_ctrack(h);
1168                 /* never fails to remove them, no listeners at this point */
1169                 nf_ct_kill(ct);
1170         }
1171         spin_unlock_bh(&nf_conntrack_lock);
1172 }
1173
1174 static void nf_conntrack_cleanup_init_net(void)
1175 {
1176         /* wait until all references to nf_conntrack_untracked are dropped */
1177         while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
1178                 schedule();
1179
1180         nf_conntrack_helper_fini();
1181         nf_conntrack_proto_fini();
1182 #ifdef CONFIG_NF_CONNTRACK_ZONES
1183         nf_ct_extend_unregister(&nf_ct_zone_extend);
1184 #endif
1185 }
1186
1187 static void nf_conntrack_cleanup_net(struct net *net)
1188 {
1189  i_see_dead_people:
1190         nf_ct_iterate_cleanup(net, kill_all, NULL);
1191         nf_ct_release_dying_list(net);
1192         if (atomic_read(&net->ct.count) != 0) {
1193                 schedule();
1194                 goto i_see_dead_people;
1195         }
1196
1197         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1198                              net->ct.htable_size);
1199         nf_conntrack_ecache_fini(net);
1200         nf_conntrack_acct_fini(net);
1201         nf_conntrack_expect_fini(net);
1202         kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1203         kfree(net->ct.slabname);
1204         free_percpu(net->ct.stat);
1205 }
1206
1207 /* Mishearing the voices in his head, our hero wonders how he's
1208    supposed to kill the mall. */
1209 void nf_conntrack_cleanup(struct net *net)
1210 {
1211         if (net_eq(net, &init_net))
1212                 rcu_assign_pointer(ip_ct_attach, NULL);
1213
1214         /* This makes sure all current packets have passed through
1215            netfilter framework.  Roll on, two-stage module
1216            delete... */
1217         synchronize_net();
1218
1219         nf_conntrack_cleanup_net(net);
1220
1221         if (net_eq(net, &init_net)) {
1222                 rcu_assign_pointer(nf_ct_destroy, NULL);
1223                 nf_conntrack_cleanup_init_net();
1224         }
1225 }
1226
1227 void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls)
1228 {
1229         struct hlist_nulls_head *hash;
1230         unsigned int nr_slots, i;
1231         size_t sz;
1232
1233         *vmalloced = 0;
1234
1235         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
1236         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
1237         sz = nr_slots * sizeof(struct hlist_nulls_head);
1238         hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
1239                                         get_order(sz));
1240         if (!hash) {
1241                 *vmalloced = 1;
1242                 printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
1243                 hash = __vmalloc(sz, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
1244         }
1245
1246         if (hash && nulls)
1247                 for (i = 0; i < nr_slots; i++)
1248                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
1249
1250         return hash;
1251 }
1252 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
1253
1254 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
1255 {
1256         int i, bucket, vmalloced, old_vmalloced;
1257         unsigned int hashsize, old_size;
1258         struct hlist_nulls_head *hash, *old_hash;
1259         struct nf_conntrack_tuple_hash *h;
1260         struct nf_conn *ct;
1261
1262         if (current->nsproxy->net_ns != &init_net)
1263                 return -EOPNOTSUPP;
1264
1265         /* On boot, we can set this without any fancy locking. */
1266         if (!nf_conntrack_htable_size)
1267                 return param_set_uint(val, kp);
1268
1269         hashsize = simple_strtoul(val, NULL, 0);
1270         if (!hashsize)
1271                 return -EINVAL;
1272
1273         hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced, 1);
1274         if (!hash)
1275                 return -ENOMEM;
1276
1277         /* Lookups in the old hash might happen in parallel, which means we
1278          * might get false negatives during connection lookup. New connections
1279          * created because of a false negative won't make it into the hash
1280          * though since that required taking the lock.
1281          */
1282         spin_lock_bh(&nf_conntrack_lock);
1283         for (i = 0; i < init_net.ct.htable_size; i++) {
1284                 while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
1285                         h = hlist_nulls_entry(init_net.ct.hash[i].first,
1286                                         struct nf_conntrack_tuple_hash, hnnode);
1287                         ct = nf_ct_tuplehash_to_ctrack(h);
1288                         hlist_nulls_del_rcu(&h->hnnode);
1289                         bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
1290                                                   hashsize,
1291                                                   nf_conntrack_hash_rnd);
1292                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
1293                 }
1294         }
1295         old_size = init_net.ct.htable_size;
1296         old_vmalloced = init_net.ct.hash_vmalloc;
1297         old_hash = init_net.ct.hash;
1298
1299         init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
1300         init_net.ct.hash_vmalloc = vmalloced;
1301         init_net.ct.hash = hash;
1302         spin_unlock_bh(&nf_conntrack_lock);
1303
1304         nf_ct_free_hashtable(old_hash, old_vmalloced, old_size);
1305         return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
1308
1309 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
1310                   &nf_conntrack_htable_size, 0600);
1311
1312 static int nf_conntrack_init_init_net(void)
1313 {
1314         int max_factor = 8;
1315         int ret;
1316
1317         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
1318          * machine has 512 buckets. >= 1GB machines have 16384 buckets. */
1319         if (!nf_conntrack_htable_size) {
1320                 nf_conntrack_htable_size
1321                         = (((totalram_pages << PAGE_SHIFT) / 16384)
1322                            / sizeof(struct hlist_head));
1323                 if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
1324                         nf_conntrack_htable_size = 16384;
1325                 if (nf_conntrack_htable_size < 32)
1326                         nf_conntrack_htable_size = 32;
1327
1328                 /* Use a max. factor of four by default to get the same max as
1329                  * with the old struct list_heads. When a table size is given
1330                  * we use the old value of 8 to avoid reducing the max.
1331                  * entries. */
1332                 max_factor = 4;
1333         }
1334         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
1335
1336         printk("nf_conntrack version %s (%u buckets, %d max)\n",
1337                NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
1338                nf_conntrack_max);
1339
1340         ret = nf_conntrack_proto_init();
1341         if (ret < 0)
1342                 goto err_proto;
1343
1344         ret = nf_conntrack_helper_init();
1345         if (ret < 0)
1346                 goto err_helper;
1347
1348 #ifdef CONFIG_NF_CONNTRACK_ZONES
1349         ret = nf_ct_extend_register(&nf_ct_zone_extend);
1350         if (ret < 0)
1351                 goto err_extend;
1352 #endif
1353         /* Set up fake conntrack: to never be deleted, not in any hashes */
1354 #ifdef CONFIG_NET_NS
1355         nf_conntrack_untracked.ct_net = &init_net;
1356 #endif
1357         atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
1358         /*  - and look it like as a confirmed connection */
1359         set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
1360
1361         return 0;
1362
1363 #ifdef CONFIG_NF_CONNTRACK_ZONES
1364 err_extend:
1365         nf_conntrack_helper_fini();
1366 #endif
1367 err_helper:
1368         nf_conntrack_proto_fini();
1369 err_proto:
1370         return ret;
1371 }
1372
1373 /*
1374  * We need to use special "null" values, not used in hash table
1375  */
1376 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
1377 #define DYING_NULLS_VAL         ((1<<30)+1)
1378
1379 static int nf_conntrack_init_net(struct net *net)
1380 {
1381         int ret;
1382
1383         atomic_set(&net->ct.count, 0);
1384         INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
1385         INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
1386         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
1387         if (!net->ct.stat) {
1388                 ret = -ENOMEM;
1389                 goto err_stat;
1390         }
1391
1392         net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
1393         if (!net->ct.slabname) {
1394                 ret = -ENOMEM;
1395                 goto err_slabname;
1396         }
1397
1398         net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
1399                                                         sizeof(struct nf_conn), 0,
1400                                                         SLAB_DESTROY_BY_RCU, NULL);
1401         if (!net->ct.nf_conntrack_cachep) {
1402                 printk(KERN_ERR "Unable to create nf_conn slab cache\n");
1403                 ret = -ENOMEM;
1404                 goto err_cache;
1405         }
1406
1407         net->ct.htable_size = nf_conntrack_htable_size;
1408         net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size,
1409                                              &net->ct.hash_vmalloc, 1);
1410         if (!net->ct.hash) {
1411                 ret = -ENOMEM;
1412                 printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
1413                 goto err_hash;
1414         }
1415         ret = nf_conntrack_expect_init(net);
1416         if (ret < 0)
1417                 goto err_expect;
1418         ret = nf_conntrack_acct_init(net);
1419         if (ret < 0)
1420                 goto err_acct;
1421         ret = nf_conntrack_ecache_init(net);
1422         if (ret < 0)
1423                 goto err_ecache;
1424
1425         return 0;
1426
1427 err_ecache:
1428         nf_conntrack_acct_fini(net);
1429 err_acct:
1430         nf_conntrack_expect_fini(net);
1431 err_expect:
1432         nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
1433                              net->ct.htable_size);
1434 err_hash:
1435         kmem_cache_destroy(net->ct.nf_conntrack_cachep);
1436 err_cache:
1437         kfree(net->ct.slabname);
1438 err_slabname:
1439         free_percpu(net->ct.stat);
1440 err_stat:
1441         return ret;
1442 }
1443
1444 s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
1445                         enum ip_conntrack_dir dir,
1446                         u32 seq);
1447 EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
1448
1449 int nf_conntrack_init(struct net *net)
1450 {
1451         int ret;
1452
1453         if (net_eq(net, &init_net)) {
1454                 ret = nf_conntrack_init_init_net();
1455                 if (ret < 0)
1456                         goto out_init_net;
1457         }
1458         ret = nf_conntrack_init_net(net);
1459         if (ret < 0)
1460                 goto out_net;
1461
1462         if (net_eq(net, &init_net)) {
1463                 /* For use by REJECT target */
1464                 rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
1465                 rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
1466
1467                 /* Howto get NAT offsets */
1468                 rcu_assign_pointer(nf_ct_nat_offset, NULL);
1469         }
1470         return 0;
1471
1472 out_net:
1473         if (net_eq(net, &init_net))
1474                 nf_conntrack_cleanup_init_net();
1475 out_init_net:
1476         return ret;
1477 }