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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_conntrack_timestamp.h> | |
47 | #include <net/netfilter/nf_conntrack_timeout.h> | |
48 | #include <net/netfilter/nf_conntrack_labels.h> | |
49 | #include <net/netfilter/nf_nat.h> | |
50 | #include <net/netfilter/nf_nat_core.h> | |
51 | ||
52 | #define NF_CONNTRACK_VERSION "0.5.0" | |
53 | ||
54 | int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct, | |
55 | enum nf_nat_manip_type manip, | |
56 | const struct nlattr *attr) __read_mostly; | |
57 | EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook); | |
58 | ||
59 | int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb, | |
60 | struct nf_conn *ct, | |
61 | enum ip_conntrack_info ctinfo, | |
62 | unsigned int protoff); | |
63 | EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook); | |
64 | ||
65 | DEFINE_SPINLOCK(nf_conntrack_lock); | |
66 | EXPORT_SYMBOL_GPL(nf_conntrack_lock); | |
67 | ||
68 | unsigned int nf_conntrack_htable_size __read_mostly; | |
69 | EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); | |
70 | ||
71 | unsigned int nf_conntrack_max __read_mostly; | |
72 | EXPORT_SYMBOL_GPL(nf_conntrack_max); | |
73 | ||
74 | DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked); | |
75 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked); | |
76 | ||
77 | unsigned int nf_conntrack_hash_rnd __read_mostly; | |
78 | EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd); | |
79 | ||
80 | static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone) | |
81 | { | |
82 | unsigned int n; | |
83 | ||
84 | /* The direction must be ignored, so we hash everything up to the | |
85 | * destination ports (which is a multiple of 4) and treat the last | |
86 | * three bytes manually. | |
87 | */ | |
88 | n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32); | |
89 | return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^ | |
90 | (((__force __u16)tuple->dst.u.all << 16) | | |
91 | tuple->dst.protonum)); | |
92 | } | |
93 | ||
94 | static u32 __hash_bucket(u32 hash, unsigned int size) | |
95 | { | |
96 | return ((u64)hash * size) >> 32; | |
97 | } | |
98 | ||
99 | static u32 hash_bucket(u32 hash, const struct net *net) | |
100 | { | |
101 | return __hash_bucket(hash, net->ct.htable_size); | |
102 | } | |
103 | ||
104 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
105 | u16 zone, unsigned int size) | |
106 | { | |
107 | return __hash_bucket(hash_conntrack_raw(tuple, zone), size); | |
108 | } | |
109 | ||
110 | static inline u_int32_t hash_conntrack(const struct net *net, u16 zone, | |
111 | const struct nf_conntrack_tuple *tuple) | |
112 | { | |
113 | return __hash_conntrack(tuple, zone, net->ct.htable_size); | |
114 | } | |
115 | ||
116 | bool | |
117 | nf_ct_get_tuple(const struct sk_buff *skb, | |
118 | unsigned int nhoff, | |
119 | unsigned int dataoff, | |
120 | u_int16_t l3num, | |
121 | u_int8_t protonum, | |
122 | struct nf_conntrack_tuple *tuple, | |
123 | const struct nf_conntrack_l3proto *l3proto, | |
124 | const struct nf_conntrack_l4proto *l4proto) | |
125 | { | |
126 | memset(tuple, 0, sizeof(*tuple)); | |
127 | ||
128 | tuple->src.l3num = l3num; | |
129 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
130 | return false; | |
131 | ||
132 | tuple->dst.protonum = protonum; | |
133 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
134 | ||
135 | return l4proto->pkt_to_tuple(skb, dataoff, tuple); | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(nf_ct_get_tuple); | |
138 | ||
139 | bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff, | |
140 | u_int16_t l3num, struct nf_conntrack_tuple *tuple) | |
141 | { | |
142 | struct nf_conntrack_l3proto *l3proto; | |
143 | struct nf_conntrack_l4proto *l4proto; | |
144 | unsigned int protoff; | |
145 | u_int8_t protonum; | |
146 | int ret; | |
147 | ||
148 | rcu_read_lock(); | |
149 | ||
150 | l3proto = __nf_ct_l3proto_find(l3num); | |
151 | ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum); | |
152 | if (ret != NF_ACCEPT) { | |
153 | rcu_read_unlock(); | |
154 | return false; | |
155 | } | |
156 | ||
157 | l4proto = __nf_ct_l4proto_find(l3num, protonum); | |
158 | ||
159 | ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple, | |
160 | l3proto, l4proto); | |
161 | ||
162 | rcu_read_unlock(); | |
163 | return ret; | |
164 | } | |
165 | EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr); | |
166 | ||
167 | bool | |
168 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
169 | const struct nf_conntrack_tuple *orig, | |
170 | const struct nf_conntrack_l3proto *l3proto, | |
171 | const struct nf_conntrack_l4proto *l4proto) | |
172 | { | |
173 | memset(inverse, 0, sizeof(*inverse)); | |
174 | ||
175 | inverse->src.l3num = orig->src.l3num; | |
176 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
177 | return false; | |
178 | ||
179 | inverse->dst.dir = !orig->dst.dir; | |
180 | ||
181 | inverse->dst.protonum = orig->dst.protonum; | |
182 | return l4proto->invert_tuple(inverse, orig); | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); | |
185 | ||
186 | static void | |
187 | clean_from_lists(struct nf_conn *ct) | |
188 | { | |
189 | pr_debug("clean_from_lists(%p)\n", ct); | |
190 | hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); | |
191 | hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode); | |
192 | ||
193 | /* Destroy all pending expectations */ | |
194 | nf_ct_remove_expectations(ct); | |
195 | } | |
196 | ||
197 | static void | |
198 | destroy_conntrack(struct nf_conntrack *nfct) | |
199 | { | |
200 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
201 | struct net *net = nf_ct_net(ct); | |
202 | struct nf_conntrack_l4proto *l4proto; | |
203 | ||
204 | pr_debug("destroy_conntrack(%p)\n", ct); | |
205 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); | |
206 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
207 | ||
208 | /* To make sure we don't get any weird locking issues here: | |
209 | * destroy_conntrack() MUST NOT be called with a write lock | |
210 | * to nf_conntrack_lock!!! -HW */ | |
211 | rcu_read_lock(); | |
212 | l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct)); | |
213 | if (l4proto && l4proto->destroy) | |
214 | l4proto->destroy(ct); | |
215 | ||
216 | rcu_read_unlock(); | |
217 | ||
218 | spin_lock_bh(&nf_conntrack_lock); | |
219 | /* Expectations will have been removed in clean_from_lists, | |
220 | * except TFTP can create an expectation on the first packet, | |
221 | * before connection is in the list, so we need to clean here, | |
222 | * too. */ | |
223 | nf_ct_remove_expectations(ct); | |
224 | ||
225 | /* We overload first tuple to link into unconfirmed or dying list.*/ | |
226 | BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode)); | |
227 | hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); | |
228 | ||
229 | NF_CT_STAT_INC(net, delete); | |
230 | spin_unlock_bh(&nf_conntrack_lock); | |
231 | ||
232 | if (ct->master) | |
233 | nf_ct_put(ct->master); | |
234 | ||
235 | pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct); | |
236 | nf_conntrack_free(ct); | |
237 | } | |
238 | ||
239 | void nf_ct_delete_from_lists(struct nf_conn *ct) | |
240 | { | |
241 | struct net *net = nf_ct_net(ct); | |
242 | ||
243 | nf_ct_helper_destroy(ct); | |
244 | spin_lock_bh(&nf_conntrack_lock); | |
245 | /* Inside lock so preempt is disabled on module removal path. | |
246 | * Otherwise we can get spurious warnings. */ | |
247 | NF_CT_STAT_INC(net, delete_list); | |
248 | clean_from_lists(ct); | |
249 | /* add this conntrack to the dying list */ | |
250 | hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
251 | &net->ct.dying); | |
252 | spin_unlock_bh(&nf_conntrack_lock); | |
253 | } | |
254 | EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists); | |
255 | ||
256 | static void death_by_event(unsigned long ul_conntrack) | |
257 | { | |
258 | struct nf_conn *ct = (void *)ul_conntrack; | |
259 | struct net *net = nf_ct_net(ct); | |
260 | struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); | |
261 | ||
262 | BUG_ON(ecache == NULL); | |
263 | ||
264 | if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) { | |
265 | /* bad luck, let's retry again */ | |
266 | ecache->timeout.expires = jiffies + | |
267 | (random32() % net->ct.sysctl_events_retry_timeout); | |
268 | add_timer(&ecache->timeout); | |
269 | return; | |
270 | } | |
271 | /* we've got the event delivered, now it's dying */ | |
272 | set_bit(IPS_DYING_BIT, &ct->status); | |
273 | nf_ct_put(ct); | |
274 | } | |
275 | ||
276 | void nf_ct_dying_timeout(struct nf_conn *ct) | |
277 | { | |
278 | struct net *net = nf_ct_net(ct); | |
279 | struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); | |
280 | ||
281 | BUG_ON(ecache == NULL); | |
282 | ||
283 | /* set a new timer to retry event delivery */ | |
284 | setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct); | |
285 | ecache->timeout.expires = jiffies + | |
286 | (random32() % net->ct.sysctl_events_retry_timeout); | |
287 | add_timer(&ecache->timeout); | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(nf_ct_dying_timeout); | |
290 | ||
291 | static void death_by_timeout(unsigned long ul_conntrack) | |
292 | { | |
293 | struct nf_conn *ct = (void *)ul_conntrack; | |
294 | struct nf_conn_tstamp *tstamp; | |
295 | ||
296 | tstamp = nf_conn_tstamp_find(ct); | |
297 | if (tstamp && tstamp->stop == 0) | |
298 | tstamp->stop = ktime_to_ns(ktime_get_real()); | |
299 | ||
300 | if (!test_bit(IPS_DYING_BIT, &ct->status) && | |
301 | unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) { | |
302 | /* destroy event was not delivered */ | |
303 | nf_ct_delete_from_lists(ct); | |
304 | nf_ct_dying_timeout(ct); | |
305 | return; | |
306 | } | |
307 | set_bit(IPS_DYING_BIT, &ct->status); | |
308 | nf_ct_delete_from_lists(ct); | |
309 | nf_ct_put(ct); | |
310 | } | |
311 | ||
312 | /* | |
313 | * Warning : | |
314 | * - Caller must take a reference on returned object | |
315 | * and recheck nf_ct_tuple_equal(tuple, &h->tuple) | |
316 | * OR | |
317 | * - Caller must lock nf_conntrack_lock before calling this function | |
318 | */ | |
319 | static struct nf_conntrack_tuple_hash * | |
320 | ____nf_conntrack_find(struct net *net, u16 zone, | |
321 | const struct nf_conntrack_tuple *tuple, u32 hash) | |
322 | { | |
323 | struct nf_conntrack_tuple_hash *h; | |
324 | struct hlist_nulls_node *n; | |
325 | unsigned int bucket = hash_bucket(hash, net); | |
326 | ||
327 | /* Disable BHs the entire time since we normally need to disable them | |
328 | * at least once for the stats anyway. | |
329 | */ | |
330 | local_bh_disable(); | |
331 | begin: | |
332 | hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) { | |
333 | if (nf_ct_tuple_equal(tuple, &h->tuple) && | |
334 | nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) { | |
335 | NF_CT_STAT_INC(net, found); | |
336 | local_bh_enable(); | |
337 | return h; | |
338 | } | |
339 | NF_CT_STAT_INC(net, searched); | |
340 | } | |
341 | /* | |
342 | * if the nulls value we got at the end of this lookup is | |
343 | * not the expected one, we must restart lookup. | |
344 | * We probably met an item that was moved to another chain. | |
345 | */ | |
346 | if (get_nulls_value(n) != bucket) { | |
347 | NF_CT_STAT_INC(net, search_restart); | |
348 | goto begin; | |
349 | } | |
350 | local_bh_enable(); | |
351 | ||
352 | return NULL; | |
353 | } | |
354 | ||
355 | struct nf_conntrack_tuple_hash * | |
356 | __nf_conntrack_find(struct net *net, u16 zone, | |
357 | const struct nf_conntrack_tuple *tuple) | |
358 | { | |
359 | return ____nf_conntrack_find(net, zone, tuple, | |
360 | hash_conntrack_raw(tuple, zone)); | |
361 | } | |
362 | EXPORT_SYMBOL_GPL(__nf_conntrack_find); | |
363 | ||
364 | /* Find a connection corresponding to a tuple. */ | |
365 | static struct nf_conntrack_tuple_hash * | |
366 | __nf_conntrack_find_get(struct net *net, u16 zone, | |
367 | const struct nf_conntrack_tuple *tuple, u32 hash) | |
368 | { | |
369 | struct nf_conntrack_tuple_hash *h; | |
370 | struct nf_conn *ct; | |
371 | ||
372 | rcu_read_lock(); | |
373 | begin: | |
374 | h = ____nf_conntrack_find(net, zone, tuple, hash); | |
375 | if (h) { | |
376 | ct = nf_ct_tuplehash_to_ctrack(h); | |
377 | if (unlikely(nf_ct_is_dying(ct) || | |
378 | !atomic_inc_not_zero(&ct->ct_general.use))) | |
379 | h = NULL; | |
380 | else { | |
381 | if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) || | |
382 | nf_ct_zone(ct) != zone)) { | |
383 | nf_ct_put(ct); | |
384 | goto begin; | |
385 | } | |
386 | } | |
387 | } | |
388 | rcu_read_unlock(); | |
389 | ||
390 | return h; | |
391 | } | |
392 | ||
393 | struct nf_conntrack_tuple_hash * | |
394 | nf_conntrack_find_get(struct net *net, u16 zone, | |
395 | const struct nf_conntrack_tuple *tuple) | |
396 | { | |
397 | return __nf_conntrack_find_get(net, zone, tuple, | |
398 | hash_conntrack_raw(tuple, zone)); | |
399 | } | |
400 | EXPORT_SYMBOL_GPL(nf_conntrack_find_get); | |
401 | ||
402 | static void __nf_conntrack_hash_insert(struct nf_conn *ct, | |
403 | unsigned int hash, | |
404 | unsigned int repl_hash) | |
405 | { | |
406 | struct net *net = nf_ct_net(ct); | |
407 | ||
408 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
409 | &net->ct.hash[hash]); | |
410 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode, | |
411 | &net->ct.hash[repl_hash]); | |
412 | } | |
413 | ||
414 | int | |
415 | nf_conntrack_hash_check_insert(struct nf_conn *ct) | |
416 | { | |
417 | struct net *net = nf_ct_net(ct); | |
418 | unsigned int hash, repl_hash; | |
419 | struct nf_conntrack_tuple_hash *h; | |
420 | struct hlist_nulls_node *n; | |
421 | u16 zone; | |
422 | ||
423 | zone = nf_ct_zone(ct); | |
424 | hash = hash_conntrack(net, zone, | |
425 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
426 | repl_hash = hash_conntrack(net, zone, | |
427 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
428 | ||
429 | spin_lock_bh(&nf_conntrack_lock); | |
430 | ||
431 | /* See if there's one in the list already, including reverse */ | |
432 | hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode) | |
433 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, | |
434 | &h->tuple) && | |
435 | zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) | |
436 | goto out; | |
437 | hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode) | |
438 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, | |
439 | &h->tuple) && | |
440 | zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) | |
441 | goto out; | |
442 | ||
443 | add_timer(&ct->timeout); | |
444 | nf_conntrack_get(&ct->ct_general); | |
445 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
446 | NF_CT_STAT_INC(net, insert); | |
447 | spin_unlock_bh(&nf_conntrack_lock); | |
448 | ||
449 | return 0; | |
450 | ||
451 | out: | |
452 | NF_CT_STAT_INC(net, insert_failed); | |
453 | spin_unlock_bh(&nf_conntrack_lock); | |
454 | return -EEXIST; | |
455 | } | |
456 | EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert); | |
457 | ||
458 | /* Confirm a connection given skb; places it in hash table */ | |
459 | int | |
460 | __nf_conntrack_confirm(struct sk_buff *skb) | |
461 | { | |
462 | unsigned int hash, repl_hash; | |
463 | struct nf_conntrack_tuple_hash *h; | |
464 | struct nf_conn *ct; | |
465 | struct nf_conn_help *help; | |
466 | struct nf_conn_tstamp *tstamp; | |
467 | struct hlist_nulls_node *n; | |
468 | enum ip_conntrack_info ctinfo; | |
469 | struct net *net; | |
470 | u16 zone; | |
471 | ||
472 | ct = nf_ct_get(skb, &ctinfo); | |
473 | net = nf_ct_net(ct); | |
474 | ||
475 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
476 | ICMP/TCP RST packets in other direction. Actual packet | |
477 | which created connection will be IP_CT_NEW or for an | |
478 | expected connection, IP_CT_RELATED. */ | |
479 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
480 | return NF_ACCEPT; | |
481 | ||
482 | zone = nf_ct_zone(ct); | |
483 | /* reuse the hash saved before */ | |
484 | hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev; | |
485 | hash = hash_bucket(hash, net); | |
486 | repl_hash = hash_conntrack(net, zone, | |
487 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
488 | ||
489 | /* We're not in hash table, and we refuse to set up related | |
490 | connections for unconfirmed conns. But packet copies and | |
491 | REJECT will give spurious warnings here. */ | |
492 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
493 | ||
494 | /* No external references means no one else could have | |
495 | confirmed us. */ | |
496 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
497 | pr_debug("Confirming conntrack %p\n", ct); | |
498 | ||
499 | spin_lock_bh(&nf_conntrack_lock); | |
500 | ||
501 | /* We have to check the DYING flag inside the lock to prevent | |
502 | a race against nf_ct_get_next_corpse() possibly called from | |
503 | user context, else we insert an already 'dead' hash, blocking | |
504 | further use of that particular connection -JM */ | |
505 | ||
506 | if (unlikely(nf_ct_is_dying(ct))) { | |
507 | spin_unlock_bh(&nf_conntrack_lock); | |
508 | return NF_ACCEPT; | |
509 | } | |
510 | ||
511 | /* See if there's one in the list already, including reverse: | |
512 | NAT could have grabbed it without realizing, since we're | |
513 | not in the hash. If there is, we lost race. */ | |
514 | hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode) | |
515 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, | |
516 | &h->tuple) && | |
517 | zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) | |
518 | goto out; | |
519 | hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode) | |
520 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, | |
521 | &h->tuple) && | |
522 | zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) | |
523 | goto out; | |
524 | ||
525 | /* Remove from unconfirmed list */ | |
526 | hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); | |
527 | ||
528 | /* Timer relative to confirmation time, not original | |
529 | setting time, otherwise we'd get timer wrap in | |
530 | weird delay cases. */ | |
531 | ct->timeout.expires += jiffies; | |
532 | add_timer(&ct->timeout); | |
533 | atomic_inc(&ct->ct_general.use); | |
534 | ct->status |= IPS_CONFIRMED; | |
535 | ||
536 | /* set conntrack timestamp, if enabled. */ | |
537 | tstamp = nf_conn_tstamp_find(ct); | |
538 | if (tstamp) { | |
539 | if (skb->tstamp.tv64 == 0) | |
540 | __net_timestamp(skb); | |
541 | ||
542 | tstamp->start = ktime_to_ns(skb->tstamp); | |
543 | } | |
544 | /* Since the lookup is lockless, hash insertion must be done after | |
545 | * starting the timer and setting the CONFIRMED bit. The RCU barriers | |
546 | * guarantee that no other CPU can find the conntrack before the above | |
547 | * stores are visible. | |
548 | */ | |
549 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
550 | NF_CT_STAT_INC(net, insert); | |
551 | spin_unlock_bh(&nf_conntrack_lock); | |
552 | ||
553 | help = nfct_help(ct); | |
554 | if (help && help->helper) | |
555 | nf_conntrack_event_cache(IPCT_HELPER, ct); | |
556 | ||
557 | nf_conntrack_event_cache(master_ct(ct) ? | |
558 | IPCT_RELATED : IPCT_NEW, ct); | |
559 | return NF_ACCEPT; | |
560 | ||
561 | out: | |
562 | NF_CT_STAT_INC(net, insert_failed); | |
563 | spin_unlock_bh(&nf_conntrack_lock); | |
564 | return NF_DROP; | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); | |
567 | ||
568 | /* Returns true if a connection correspondings to the tuple (required | |
569 | for NAT). */ | |
570 | int | |
571 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
572 | const struct nf_conn *ignored_conntrack) | |
573 | { | |
574 | struct net *net = nf_ct_net(ignored_conntrack); | |
575 | struct nf_conntrack_tuple_hash *h; | |
576 | struct hlist_nulls_node *n; | |
577 | struct nf_conn *ct; | |
578 | u16 zone = nf_ct_zone(ignored_conntrack); | |
579 | unsigned int hash = hash_conntrack(net, zone, tuple); | |
580 | ||
581 | /* Disable BHs the entire time since we need to disable them at | |
582 | * least once for the stats anyway. | |
583 | */ | |
584 | rcu_read_lock_bh(); | |
585 | hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { | |
586 | ct = nf_ct_tuplehash_to_ctrack(h); | |
587 | if (ct != ignored_conntrack && | |
588 | nf_ct_tuple_equal(tuple, &h->tuple) && | |
589 | nf_ct_zone(ct) == zone) { | |
590 | NF_CT_STAT_INC(net, found); | |
591 | rcu_read_unlock_bh(); | |
592 | return 1; | |
593 | } | |
594 | NF_CT_STAT_INC(net, searched); | |
595 | } | |
596 | rcu_read_unlock_bh(); | |
597 | ||
598 | return 0; | |
599 | } | |
600 | EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); | |
601 | ||
602 | #define NF_CT_EVICTION_RANGE 8 | |
603 | ||
604 | /* There's a small race here where we may free a just-assured | |
605 | connection. Too bad: we're in trouble anyway. */ | |
606 | static noinline int early_drop(struct net *net, unsigned int hash) | |
607 | { | |
608 | /* Use oldest entry, which is roughly LRU */ | |
609 | struct nf_conntrack_tuple_hash *h; | |
610 | struct nf_conn *ct = NULL, *tmp; | |
611 | struct hlist_nulls_node *n; | |
612 | unsigned int i, cnt = 0; | |
613 | int dropped = 0; | |
614 | ||
615 | rcu_read_lock(); | |
616 | for (i = 0; i < net->ct.htable_size; i++) { | |
617 | hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], | |
618 | hnnode) { | |
619 | tmp = nf_ct_tuplehash_to_ctrack(h); | |
620 | if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) | |
621 | ct = tmp; | |
622 | cnt++; | |
623 | } | |
624 | ||
625 | if (ct != NULL) { | |
626 | if (likely(!nf_ct_is_dying(ct) && | |
627 | atomic_inc_not_zero(&ct->ct_general.use))) | |
628 | break; | |
629 | else | |
630 | ct = NULL; | |
631 | } | |
632 | ||
633 | if (cnt >= NF_CT_EVICTION_RANGE) | |
634 | break; | |
635 | ||
636 | hash = (hash + 1) % net->ct.htable_size; | |
637 | } | |
638 | rcu_read_unlock(); | |
639 | ||
640 | if (!ct) | |
641 | return dropped; | |
642 | ||
643 | if (del_timer(&ct->timeout)) { | |
644 | death_by_timeout((unsigned long)ct); | |
645 | /* Check if we indeed killed this entry. Reliable event | |
646 | delivery may have inserted it into the dying list. */ | |
647 | if (test_bit(IPS_DYING_BIT, &ct->status)) { | |
648 | dropped = 1; | |
649 | NF_CT_STAT_INC_ATOMIC(net, early_drop); | |
650 | } | |
651 | } | |
652 | nf_ct_put(ct); | |
653 | return dropped; | |
654 | } | |
655 | ||
656 | void init_nf_conntrack_hash_rnd(void) | |
657 | { | |
658 | unsigned int rand; | |
659 | ||
660 | /* | |
661 | * Why not initialize nf_conntrack_rnd in a "init()" function ? | |
662 | * Because there isn't enough entropy when system initializing, | |
663 | * and we initialize it as late as possible. | |
664 | */ | |
665 | do { | |
666 | get_random_bytes(&rand, sizeof(rand)); | |
667 | } while (!rand); | |
668 | cmpxchg(&nf_conntrack_hash_rnd, 0, rand); | |
669 | } | |
670 | ||
671 | static struct nf_conn * | |
672 | __nf_conntrack_alloc(struct net *net, u16 zone, | |
673 | const struct nf_conntrack_tuple *orig, | |
674 | const struct nf_conntrack_tuple *repl, | |
675 | gfp_t gfp, u32 hash) | |
676 | { | |
677 | struct nf_conn *ct; | |
678 | ||
679 | if (unlikely(!nf_conntrack_hash_rnd)) { | |
680 | init_nf_conntrack_hash_rnd(); | |
681 | /* recompute the hash as nf_conntrack_hash_rnd is initialized */ | |
682 | hash = hash_conntrack_raw(orig, zone); | |
683 | } | |
684 | ||
685 | /* We don't want any race condition at early drop stage */ | |
686 | atomic_inc(&net->ct.count); | |
687 | ||
688 | if (nf_conntrack_max && | |
689 | unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) { | |
690 | if (!early_drop(net, hash_bucket(hash, net))) { | |
691 | atomic_dec(&net->ct.count); | |
692 | net_warn_ratelimited("nf_conntrack: table full, dropping packet\n"); | |
693 | return ERR_PTR(-ENOMEM); | |
694 | } | |
695 | } | |
696 | ||
697 | /* | |
698 | * Do not use kmem_cache_zalloc(), as this cache uses | |
699 | * SLAB_DESTROY_BY_RCU. | |
700 | */ | |
701 | ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp); | |
702 | if (ct == NULL) { | |
703 | atomic_dec(&net->ct.count); | |
704 | return ERR_PTR(-ENOMEM); | |
705 | } | |
706 | /* | |
707 | * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next | |
708 | * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged. | |
709 | */ | |
710 | memset(&ct->tuplehash[IP_CT_DIR_MAX], 0, | |
711 | offsetof(struct nf_conn, proto) - | |
712 | offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX])); | |
713 | spin_lock_init(&ct->lock); | |
714 | ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; | |
715 | ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL; | |
716 | ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
717 | /* save hash for reusing when confirming */ | |
718 | *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash; | |
719 | /* Don't set timer yet: wait for confirmation */ | |
720 | setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct); | |
721 | write_pnet(&ct->ct_net, net); | |
722 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
723 | if (zone) { | |
724 | struct nf_conntrack_zone *nf_ct_zone; | |
725 | ||
726 | nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC); | |
727 | if (!nf_ct_zone) | |
728 | goto out_free; | |
729 | nf_ct_zone->id = zone; | |
730 | } | |
731 | #endif | |
732 | /* | |
733 | * changes to lookup keys must be done before setting refcnt to 1 | |
734 | */ | |
735 | smp_wmb(); | |
736 | atomic_set(&ct->ct_general.use, 1); | |
737 | return ct; | |
738 | ||
739 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
740 | out_free: | |
741 | atomic_dec(&net->ct.count); | |
742 | kmem_cache_free(net->ct.nf_conntrack_cachep, ct); | |
743 | return ERR_PTR(-ENOMEM); | |
744 | #endif | |
745 | } | |
746 | ||
747 | struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone, | |
748 | const struct nf_conntrack_tuple *orig, | |
749 | const struct nf_conntrack_tuple *repl, | |
750 | gfp_t gfp) | |
751 | { | |
752 | return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0); | |
753 | } | |
754 | EXPORT_SYMBOL_GPL(nf_conntrack_alloc); | |
755 | ||
756 | void nf_conntrack_free(struct nf_conn *ct) | |
757 | { | |
758 | struct net *net = nf_ct_net(ct); | |
759 | ||
760 | nf_ct_ext_destroy(ct); | |
761 | atomic_dec(&net->ct.count); | |
762 | nf_ct_ext_free(ct); | |
763 | kmem_cache_free(net->ct.nf_conntrack_cachep, ct); | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(nf_conntrack_free); | |
766 | ||
767 | ||
768 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
769 | failed due to stress. Otherwise it really is unclassifiable. */ | |
770 | static struct nf_conntrack_tuple_hash * | |
771 | init_conntrack(struct net *net, struct nf_conn *tmpl, | |
772 | const struct nf_conntrack_tuple *tuple, | |
773 | struct nf_conntrack_l3proto *l3proto, | |
774 | struct nf_conntrack_l4proto *l4proto, | |
775 | struct sk_buff *skb, | |
776 | unsigned int dataoff, u32 hash) | |
777 | { | |
778 | struct nf_conn *ct; | |
779 | struct nf_conn_help *help; | |
780 | struct nf_conntrack_tuple repl_tuple; | |
781 | struct nf_conntrack_ecache *ecache; | |
782 | struct nf_conntrack_expect *exp; | |
783 | u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; | |
784 | struct nf_conn_timeout *timeout_ext; | |
785 | unsigned int *timeouts; | |
786 | ||
787 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { | |
788 | pr_debug("Can't invert tuple.\n"); | |
789 | return NULL; | |
790 | } | |
791 | ||
792 | ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC, | |
793 | hash); | |
794 | if (IS_ERR(ct)) | |
795 | return (struct nf_conntrack_tuple_hash *)ct; | |
796 | ||
797 | timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL; | |
798 | if (timeout_ext) | |
799 | timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext); | |
800 | else | |
801 | timeouts = l4proto->get_timeouts(net); | |
802 | ||
803 | if (!l4proto->new(ct, skb, dataoff, timeouts)) { | |
804 | nf_conntrack_free(ct); | |
805 | pr_debug("init conntrack: can't track with proto module\n"); | |
806 | return NULL; | |
807 | } | |
808 | ||
809 | if (timeout_ext) | |
810 | nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC); | |
811 | ||
812 | nf_ct_acct_ext_add(ct, GFP_ATOMIC); | |
813 | nf_ct_tstamp_ext_add(ct, GFP_ATOMIC); | |
814 | nf_ct_labels_ext_add(ct); | |
815 | ||
816 | ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL; | |
817 | nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0, | |
818 | ecache ? ecache->expmask : 0, | |
819 | GFP_ATOMIC); | |
820 | ||
821 | spin_lock_bh(&nf_conntrack_lock); | |
822 | exp = nf_ct_find_expectation(net, zone, tuple); | |
823 | if (exp) { | |
824 | pr_debug("conntrack: expectation arrives ct=%p exp=%p\n", | |
825 | ct, exp); | |
826 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
827 | __set_bit(IPS_EXPECTED_BIT, &ct->status); | |
828 | ct->master = exp->master; | |
829 | if (exp->helper) { | |
830 | help = nf_ct_helper_ext_add(ct, exp->helper, | |
831 | GFP_ATOMIC); | |
832 | if (help) | |
833 | rcu_assign_pointer(help->helper, exp->helper); | |
834 | } | |
835 | ||
836 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
837 | ct->mark = exp->master->mark; | |
838 | #endif | |
839 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
840 | ct->secmark = exp->master->secmark; | |
841 | #endif | |
842 | nf_conntrack_get(&ct->master->ct_general); | |
843 | NF_CT_STAT_INC(net, expect_new); | |
844 | } else { | |
845 | __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC); | |
846 | NF_CT_STAT_INC(net, new); | |
847 | } | |
848 | ||
849 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
850 | hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, | |
851 | &net->ct.unconfirmed); | |
852 | ||
853 | spin_unlock_bh(&nf_conntrack_lock); | |
854 | ||
855 | if (exp) { | |
856 | if (exp->expectfn) | |
857 | exp->expectfn(ct, exp); | |
858 | nf_ct_expect_put(exp); | |
859 | } | |
860 | ||
861 | return &ct->tuplehash[IP_CT_DIR_ORIGINAL]; | |
862 | } | |
863 | ||
864 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
865 | static inline struct nf_conn * | |
866 | resolve_normal_ct(struct net *net, struct nf_conn *tmpl, | |
867 | struct sk_buff *skb, | |
868 | unsigned int dataoff, | |
869 | u_int16_t l3num, | |
870 | u_int8_t protonum, | |
871 | struct nf_conntrack_l3proto *l3proto, | |
872 | struct nf_conntrack_l4proto *l4proto, | |
873 | int *set_reply, | |
874 | enum ip_conntrack_info *ctinfo) | |
875 | { | |
876 | struct nf_conntrack_tuple tuple; | |
877 | struct nf_conntrack_tuple_hash *h; | |
878 | struct nf_conn *ct; | |
879 | u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; | |
880 | u32 hash; | |
881 | ||
882 | if (!nf_ct_get_tuple(skb, skb_network_offset(skb), | |
883 | dataoff, l3num, protonum, &tuple, l3proto, | |
884 | l4proto)) { | |
885 | pr_debug("resolve_normal_ct: Can't get tuple\n"); | |
886 | return NULL; | |
887 | } | |
888 | ||
889 | /* look for tuple match */ | |
890 | hash = hash_conntrack_raw(&tuple, zone); | |
891 | h = __nf_conntrack_find_get(net, zone, &tuple, hash); | |
892 | if (!h) { | |
893 | h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto, | |
894 | skb, dataoff, hash); | |
895 | if (!h) | |
896 | return NULL; | |
897 | if (IS_ERR(h)) | |
898 | return (void *)h; | |
899 | } | |
900 | ct = nf_ct_tuplehash_to_ctrack(h); | |
901 | ||
902 | /* It exists; we have (non-exclusive) reference. */ | |
903 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
904 | *ctinfo = IP_CT_ESTABLISHED_REPLY; | |
905 | /* Please set reply bit if this packet OK */ | |
906 | *set_reply = 1; | |
907 | } else { | |
908 | /* Once we've had two way comms, always ESTABLISHED. */ | |
909 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
910 | pr_debug("nf_conntrack_in: normal packet for %p\n", ct); | |
911 | *ctinfo = IP_CT_ESTABLISHED; | |
912 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
913 | pr_debug("nf_conntrack_in: related packet for %p\n", | |
914 | ct); | |
915 | *ctinfo = IP_CT_RELATED; | |
916 | } else { | |
917 | pr_debug("nf_conntrack_in: new packet for %p\n", ct); | |
918 | *ctinfo = IP_CT_NEW; | |
919 | } | |
920 | *set_reply = 0; | |
921 | } | |
922 | skb->nfct = &ct->ct_general; | |
923 | skb->nfctinfo = *ctinfo; | |
924 | return ct; | |
925 | } | |
926 | ||
927 | unsigned int | |
928 | nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum, | |
929 | struct sk_buff *skb) | |
930 | { | |
931 | struct nf_conn *ct, *tmpl = NULL; | |
932 | enum ip_conntrack_info ctinfo; | |
933 | struct nf_conntrack_l3proto *l3proto; | |
934 | struct nf_conntrack_l4proto *l4proto; | |
935 | unsigned int *timeouts; | |
936 | unsigned int dataoff; | |
937 | u_int8_t protonum; | |
938 | int set_reply = 0; | |
939 | int ret; | |
940 | ||
941 | if (skb->nfct) { | |
942 | /* Previously seen (loopback or untracked)? Ignore. */ | |
943 | tmpl = (struct nf_conn *)skb->nfct; | |
944 | if (!nf_ct_is_template(tmpl)) { | |
945 | NF_CT_STAT_INC_ATOMIC(net, ignore); | |
946 | return NF_ACCEPT; | |
947 | } | |
948 | skb->nfct = NULL; | |
949 | } | |
950 | ||
951 | /* rcu_read_lock()ed by nf_hook_slow */ | |
952 | l3proto = __nf_ct_l3proto_find(pf); | |
953 | ret = l3proto->get_l4proto(skb, skb_network_offset(skb), | |
954 | &dataoff, &protonum); | |
955 | if (ret <= 0) { | |
956 | pr_debug("not prepared to track yet or error occurred\n"); | |
957 | NF_CT_STAT_INC_ATOMIC(net, error); | |
958 | NF_CT_STAT_INC_ATOMIC(net, invalid); | |
959 | ret = -ret; | |
960 | goto out; | |
961 | } | |
962 | ||
963 | l4proto = __nf_ct_l4proto_find(pf, protonum); | |
964 | ||
965 | /* It may be an special packet, error, unclean... | |
966 | * inverse of the return code tells to the netfilter | |
967 | * core what to do with the packet. */ | |
968 | if (l4proto->error != NULL) { | |
969 | ret = l4proto->error(net, tmpl, skb, dataoff, &ctinfo, | |
970 | pf, hooknum); | |
971 | if (ret <= 0) { | |
972 | NF_CT_STAT_INC_ATOMIC(net, error); | |
973 | NF_CT_STAT_INC_ATOMIC(net, invalid); | |
974 | ret = -ret; | |
975 | goto out; | |
976 | } | |
977 | /* ICMP[v6] protocol trackers may assign one conntrack. */ | |
978 | if (skb->nfct) | |
979 | goto out; | |
980 | } | |
981 | ||
982 | ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum, | |
983 | l3proto, l4proto, &set_reply, &ctinfo); | |
984 | if (!ct) { | |
985 | /* Not valid part of a connection */ | |
986 | NF_CT_STAT_INC_ATOMIC(net, invalid); | |
987 | ret = NF_ACCEPT; | |
988 | goto out; | |
989 | } | |
990 | ||
991 | if (IS_ERR(ct)) { | |
992 | /* Too stressed to deal. */ | |
993 | NF_CT_STAT_INC_ATOMIC(net, drop); | |
994 | ret = NF_DROP; | |
995 | goto out; | |
996 | } | |
997 | ||
998 | NF_CT_ASSERT(skb->nfct); | |
999 | ||
1000 | /* Decide what timeout policy we want to apply to this flow. */ | |
1001 | timeouts = nf_ct_timeout_lookup(net, ct, l4proto); | |
1002 | ||
1003 | ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts); | |
1004 | if (ret <= 0) { | |
1005 | /* Invalid: inverse of the return code tells | |
1006 | * the netfilter core what to do */ | |
1007 | pr_debug("nf_conntrack_in: Can't track with proto module\n"); | |
1008 | nf_conntrack_put(skb->nfct); | |
1009 | skb->nfct = NULL; | |
1010 | NF_CT_STAT_INC_ATOMIC(net, invalid); | |
1011 | if (ret == -NF_DROP) | |
1012 | NF_CT_STAT_INC_ATOMIC(net, drop); | |
1013 | ret = -ret; | |
1014 | goto out; | |
1015 | } | |
1016 | ||
1017 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
1018 | nf_conntrack_event_cache(IPCT_REPLY, ct); | |
1019 | out: | |
1020 | if (tmpl) { | |
1021 | /* Special case: we have to repeat this hook, assign the | |
1022 | * template again to this packet. We assume that this packet | |
1023 | * has no conntrack assigned. This is used by nf_ct_tcp. */ | |
1024 | if (ret == NF_REPEAT) | |
1025 | skb->nfct = (struct nf_conntrack *)tmpl; | |
1026 | else | |
1027 | nf_ct_put(tmpl); | |
1028 | } | |
1029 | ||
1030 | return ret; | |
1031 | } | |
1032 | EXPORT_SYMBOL_GPL(nf_conntrack_in); | |
1033 | ||
1034 | bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
1035 | const struct nf_conntrack_tuple *orig) | |
1036 | { | |
1037 | bool ret; | |
1038 | ||
1039 | rcu_read_lock(); | |
1040 | ret = nf_ct_invert_tuple(inverse, orig, | |
1041 | __nf_ct_l3proto_find(orig->src.l3num), | |
1042 | __nf_ct_l4proto_find(orig->src.l3num, | |
1043 | orig->dst.protonum)); | |
1044 | rcu_read_unlock(); | |
1045 | return ret; | |
1046 | } | |
1047 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); | |
1048 | ||
1049 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is | |
1050 | implicitly racy: see __nf_conntrack_confirm */ | |
1051 | void nf_conntrack_alter_reply(struct nf_conn *ct, | |
1052 | const struct nf_conntrack_tuple *newreply) | |
1053 | { | |
1054 | struct nf_conn_help *help = nfct_help(ct); | |
1055 | ||
1056 | /* Should be unconfirmed, so not in hash table yet */ | |
1057 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
1058 | ||
1059 | pr_debug("Altering reply tuple of %p to ", ct); | |
1060 | nf_ct_dump_tuple(newreply); | |
1061 | ||
1062 | ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; | |
1063 | if (ct->master || (help && !hlist_empty(&help->expectations))) | |
1064 | return; | |
1065 | ||
1066 | rcu_read_lock(); | |
1067 | __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC); | |
1068 | rcu_read_unlock(); | |
1069 | } | |
1070 | EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); | |
1071 | ||
1072 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ | |
1073 | void __nf_ct_refresh_acct(struct nf_conn *ct, | |
1074 | enum ip_conntrack_info ctinfo, | |
1075 | const struct sk_buff *skb, | |
1076 | unsigned long extra_jiffies, | |
1077 | int do_acct) | |
1078 | { | |
1079 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); | |
1080 | NF_CT_ASSERT(skb); | |
1081 | ||
1082 | /* Only update if this is not a fixed timeout */ | |
1083 | if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) | |
1084 | goto acct; | |
1085 | ||
1086 | /* If not in hash table, timer will not be active yet */ | |
1087 | if (!nf_ct_is_confirmed(ct)) { | |
1088 | ct->timeout.expires = extra_jiffies; | |
1089 | } else { | |
1090 | unsigned long newtime = jiffies + extra_jiffies; | |
1091 | ||
1092 | /* Only update the timeout if the new timeout is at least | |
1093 | HZ jiffies from the old timeout. Need del_timer for race | |
1094 | avoidance (may already be dying). */ | |
1095 | if (newtime - ct->timeout.expires >= HZ) | |
1096 | mod_timer_pending(&ct->timeout, newtime); | |
1097 | } | |
1098 | ||
1099 | acct: | |
1100 | if (do_acct) { | |
1101 | struct nf_conn_counter *acct; | |
1102 | ||
1103 | acct = nf_conn_acct_find(ct); | |
1104 | if (acct) { | |
1105 | atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets); | |
1106 | atomic64_add(skb->len, &acct[CTINFO2DIR(ctinfo)].bytes); | |
1107 | } | |
1108 | } | |
1109 | } | |
1110 | EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); | |
1111 | ||
1112 | bool __nf_ct_kill_acct(struct nf_conn *ct, | |
1113 | enum ip_conntrack_info ctinfo, | |
1114 | const struct sk_buff *skb, | |
1115 | int do_acct) | |
1116 | { | |
1117 | if (do_acct) { | |
1118 | struct nf_conn_counter *acct; | |
1119 | ||
1120 | acct = nf_conn_acct_find(ct); | |
1121 | if (acct) { | |
1122 | atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets); | |
1123 | atomic64_add(skb->len - skb_network_offset(skb), | |
1124 | &acct[CTINFO2DIR(ctinfo)].bytes); | |
1125 | } | |
1126 | } | |
1127 | ||
1128 | if (del_timer(&ct->timeout)) { | |
1129 | ct->timeout.function((unsigned long)ct); | |
1130 | return true; | |
1131 | } | |
1132 | return false; | |
1133 | } | |
1134 | EXPORT_SYMBOL_GPL(__nf_ct_kill_acct); | |
1135 | ||
1136 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
1137 | static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = { | |
1138 | .len = sizeof(struct nf_conntrack_zone), | |
1139 | .align = __alignof__(struct nf_conntrack_zone), | |
1140 | .id = NF_CT_EXT_ZONE, | |
1141 | }; | |
1142 | #endif | |
1143 | ||
1144 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) | |
1145 | ||
1146 | #include <linux/netfilter/nfnetlink.h> | |
1147 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
1148 | #include <linux/mutex.h> | |
1149 | ||
1150 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
1151 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
1152 | * or depend on ctnetlink */ | |
1153 | int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb, | |
1154 | const struct nf_conntrack_tuple *tuple) | |
1155 | { | |
1156 | if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) || | |
1157 | nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port)) | |
1158 | goto nla_put_failure; | |
1159 | return 0; | |
1160 | ||
1161 | nla_put_failure: | |
1162 | return -1; | |
1163 | } | |
1164 | EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr); | |
1165 | ||
1166 | const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = { | |
1167 | [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 }, | |
1168 | [CTA_PROTO_DST_PORT] = { .type = NLA_U16 }, | |
1169 | }; | |
1170 | EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy); | |
1171 | ||
1172 | int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[], | |
1173 | struct nf_conntrack_tuple *t) | |
1174 | { | |
1175 | if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT]) | |
1176 | return -EINVAL; | |
1177 | ||
1178 | t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]); | |
1179 | t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]); | |
1180 | ||
1181 | return 0; | |
1182 | } | |
1183 | EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple); | |
1184 | ||
1185 | int nf_ct_port_nlattr_tuple_size(void) | |
1186 | { | |
1187 | return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1); | |
1188 | } | |
1189 | EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size); | |
1190 | #endif | |
1191 | ||
1192 | /* Used by ipt_REJECT and ip6t_REJECT. */ | |
1193 | static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1194 | { | |
1195 | struct nf_conn *ct; | |
1196 | enum ip_conntrack_info ctinfo; | |
1197 | ||
1198 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1199 | ct = nf_ct_get(skb, &ctinfo); | |
1200 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1201 | ctinfo = IP_CT_RELATED_REPLY; | |
1202 | else | |
1203 | ctinfo = IP_CT_RELATED; | |
1204 | ||
1205 | /* Attach to new skbuff, and increment count */ | |
1206 | nskb->nfct = &ct->ct_general; | |
1207 | nskb->nfctinfo = ctinfo; | |
1208 | nf_conntrack_get(nskb->nfct); | |
1209 | } | |
1210 | ||
1211 | /* Bring out ya dead! */ | |
1212 | static struct nf_conn * | |
1213 | get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), | |
1214 | void *data, unsigned int *bucket) | |
1215 | { | |
1216 | struct nf_conntrack_tuple_hash *h; | |
1217 | struct nf_conn *ct; | |
1218 | struct hlist_nulls_node *n; | |
1219 | ||
1220 | spin_lock_bh(&nf_conntrack_lock); | |
1221 | for (; *bucket < net->ct.htable_size; (*bucket)++) { | |
1222 | hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) { | |
1223 | if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL) | |
1224 | continue; | |
1225 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1226 | if (iter(ct, data)) | |
1227 | goto found; | |
1228 | } | |
1229 | } | |
1230 | hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) { | |
1231 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1232 | if (iter(ct, data)) | |
1233 | set_bit(IPS_DYING_BIT, &ct->status); | |
1234 | } | |
1235 | spin_unlock_bh(&nf_conntrack_lock); | |
1236 | return NULL; | |
1237 | found: | |
1238 | atomic_inc(&ct->ct_general.use); | |
1239 | spin_unlock_bh(&nf_conntrack_lock); | |
1240 | return ct; | |
1241 | } | |
1242 | ||
1243 | void nf_ct_iterate_cleanup(struct net *net, | |
1244 | int (*iter)(struct nf_conn *i, void *data), | |
1245 | void *data) | |
1246 | { | |
1247 | struct nf_conn *ct; | |
1248 | unsigned int bucket = 0; | |
1249 | ||
1250 | while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) { | |
1251 | /* Time to push up daises... */ | |
1252 | if (del_timer(&ct->timeout)) | |
1253 | death_by_timeout((unsigned long)ct); | |
1254 | /* ... else the timer will get him soon. */ | |
1255 | ||
1256 | nf_ct_put(ct); | |
1257 | } | |
1258 | } | |
1259 | EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); | |
1260 | ||
1261 | struct __nf_ct_flush_report { | |
1262 | u32 pid; | |
1263 | int report; | |
1264 | }; | |
1265 | ||
1266 | static int kill_report(struct nf_conn *i, void *data) | |
1267 | { | |
1268 | struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data; | |
1269 | struct nf_conn_tstamp *tstamp; | |
1270 | ||
1271 | tstamp = nf_conn_tstamp_find(i); | |
1272 | if (tstamp && tstamp->stop == 0) | |
1273 | tstamp->stop = ktime_to_ns(ktime_get_real()); | |
1274 | ||
1275 | /* If we fail to deliver the event, death_by_timeout() will retry */ | |
1276 | if (nf_conntrack_event_report(IPCT_DESTROY, i, | |
1277 | fr->pid, fr->report) < 0) | |
1278 | return 1; | |
1279 | ||
1280 | /* Avoid the delivery of the destroy event in death_by_timeout(). */ | |
1281 | set_bit(IPS_DYING_BIT, &i->status); | |
1282 | return 1; | |
1283 | } | |
1284 | ||
1285 | static int kill_all(struct nf_conn *i, void *data) | |
1286 | { | |
1287 | return 1; | |
1288 | } | |
1289 | ||
1290 | void nf_ct_free_hashtable(void *hash, unsigned int size) | |
1291 | { | |
1292 | if (is_vmalloc_addr(hash)) | |
1293 | vfree(hash); | |
1294 | else | |
1295 | free_pages((unsigned long)hash, | |
1296 | get_order(sizeof(struct hlist_head) * size)); | |
1297 | } | |
1298 | EXPORT_SYMBOL_GPL(nf_ct_free_hashtable); | |
1299 | ||
1300 | void nf_conntrack_flush_report(struct net *net, u32 pid, int report) | |
1301 | { | |
1302 | struct __nf_ct_flush_report fr = { | |
1303 | .pid = pid, | |
1304 | .report = report, | |
1305 | }; | |
1306 | nf_ct_iterate_cleanup(net, kill_report, &fr); | |
1307 | } | |
1308 | EXPORT_SYMBOL_GPL(nf_conntrack_flush_report); | |
1309 | ||
1310 | static void nf_ct_release_dying_list(struct net *net) | |
1311 | { | |
1312 | struct nf_conntrack_tuple_hash *h; | |
1313 | struct nf_conn *ct; | |
1314 | struct hlist_nulls_node *n; | |
1315 | ||
1316 | spin_lock_bh(&nf_conntrack_lock); | |
1317 | hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) { | |
1318 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1319 | /* never fails to remove them, no listeners at this point */ | |
1320 | nf_ct_kill(ct); | |
1321 | } | |
1322 | spin_unlock_bh(&nf_conntrack_lock); | |
1323 | } | |
1324 | ||
1325 | static int untrack_refs(void) | |
1326 | { | |
1327 | int cnt = 0, cpu; | |
1328 | ||
1329 | for_each_possible_cpu(cpu) { | |
1330 | struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu); | |
1331 | ||
1332 | cnt += atomic_read(&ct->ct_general.use) - 1; | |
1333 | } | |
1334 | return cnt; | |
1335 | } | |
1336 | ||
1337 | void nf_conntrack_cleanup_start(void) | |
1338 | { | |
1339 | RCU_INIT_POINTER(ip_ct_attach, NULL); | |
1340 | } | |
1341 | ||
1342 | void nf_conntrack_cleanup_end(void) | |
1343 | { | |
1344 | RCU_INIT_POINTER(nf_ct_destroy, NULL); | |
1345 | while (untrack_refs() > 0) | |
1346 | schedule(); | |
1347 | ||
1348 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
1349 | nf_ct_extend_unregister(&nf_ct_zone_extend); | |
1350 | #endif | |
1351 | nf_conntrack_labels_fini(); | |
1352 | nf_conntrack_helper_fini(); | |
1353 | nf_conntrack_timeout_fini(); | |
1354 | nf_conntrack_ecache_fini(); | |
1355 | nf_conntrack_tstamp_fini(); | |
1356 | nf_conntrack_acct_fini(); | |
1357 | nf_conntrack_expect_fini(); | |
1358 | } | |
1359 | ||
1360 | /* | |
1361 | * Mishearing the voices in his head, our hero wonders how he's | |
1362 | * supposed to kill the mall. | |
1363 | */ | |
1364 | void nf_conntrack_cleanup_net(struct net *net) | |
1365 | { | |
1366 | /* | |
1367 | * This makes sure all current packets have passed through | |
1368 | * netfilter framework. Roll on, two-stage module | |
1369 | * delete... | |
1370 | */ | |
1371 | synchronize_net(); | |
1372 | i_see_dead_people: | |
1373 | nf_ct_iterate_cleanup(net, kill_all, NULL); | |
1374 | nf_ct_release_dying_list(net); | |
1375 | if (atomic_read(&net->ct.count) != 0) { | |
1376 | schedule(); | |
1377 | goto i_see_dead_people; | |
1378 | } | |
1379 | ||
1380 | nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); | |
1381 | nf_conntrack_proto_fini(net); | |
1382 | nf_conntrack_helper_pernet_fini(net); | |
1383 | nf_conntrack_ecache_pernet_fini(net); | |
1384 | nf_conntrack_tstamp_pernet_fini(net); | |
1385 | nf_conntrack_acct_pernet_fini(net); | |
1386 | nf_conntrack_expect_pernet_fini(net); | |
1387 | kmem_cache_destroy(net->ct.nf_conntrack_cachep); | |
1388 | kfree(net->ct.slabname); | |
1389 | free_percpu(net->ct.stat); | |
1390 | } | |
1391 | ||
1392 | void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) | |
1393 | { | |
1394 | struct hlist_nulls_head *hash; | |
1395 | unsigned int nr_slots, i; | |
1396 | size_t sz; | |
1397 | ||
1398 | BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); | |
1399 | nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); | |
1400 | sz = nr_slots * sizeof(struct hlist_nulls_head); | |
1401 | hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, | |
1402 | get_order(sz)); | |
1403 | if (!hash) { | |
1404 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
1405 | hash = vzalloc(sz); | |
1406 | } | |
1407 | ||
1408 | if (hash && nulls) | |
1409 | for (i = 0; i < nr_slots; i++) | |
1410 | INIT_HLIST_NULLS_HEAD(&hash[i], i); | |
1411 | ||
1412 | return hash; | |
1413 | } | |
1414 | EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable); | |
1415 | ||
1416 | int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) | |
1417 | { | |
1418 | int i, bucket, rc; | |
1419 | unsigned int hashsize, old_size; | |
1420 | struct hlist_nulls_head *hash, *old_hash; | |
1421 | struct nf_conntrack_tuple_hash *h; | |
1422 | struct nf_conn *ct; | |
1423 | ||
1424 | if (current->nsproxy->net_ns != &init_net) | |
1425 | return -EOPNOTSUPP; | |
1426 | ||
1427 | /* On boot, we can set this without any fancy locking. */ | |
1428 | if (!nf_conntrack_htable_size) | |
1429 | return param_set_uint(val, kp); | |
1430 | ||
1431 | rc = kstrtouint(val, 0, &hashsize); | |
1432 | if (rc) | |
1433 | return rc; | |
1434 | if (!hashsize) | |
1435 | return -EINVAL; | |
1436 | ||
1437 | hash = nf_ct_alloc_hashtable(&hashsize, 1); | |
1438 | if (!hash) | |
1439 | return -ENOMEM; | |
1440 | ||
1441 | /* Lookups in the old hash might happen in parallel, which means we | |
1442 | * might get false negatives during connection lookup. New connections | |
1443 | * created because of a false negative won't make it into the hash | |
1444 | * though since that required taking the lock. | |
1445 | */ | |
1446 | spin_lock_bh(&nf_conntrack_lock); | |
1447 | for (i = 0; i < init_net.ct.htable_size; i++) { | |
1448 | while (!hlist_nulls_empty(&init_net.ct.hash[i])) { | |
1449 | h = hlist_nulls_entry(init_net.ct.hash[i].first, | |
1450 | struct nf_conntrack_tuple_hash, hnnode); | |
1451 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1452 | hlist_nulls_del_rcu(&h->hnnode); | |
1453 | bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct), | |
1454 | hashsize); | |
1455 | hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]); | |
1456 | } | |
1457 | } | |
1458 | old_size = init_net.ct.htable_size; | |
1459 | old_hash = init_net.ct.hash; | |
1460 | ||
1461 | init_net.ct.htable_size = nf_conntrack_htable_size = hashsize; | |
1462 | init_net.ct.hash = hash; | |
1463 | spin_unlock_bh(&nf_conntrack_lock); | |
1464 | ||
1465 | nf_ct_free_hashtable(old_hash, old_size); | |
1466 | return 0; | |
1467 | } | |
1468 | EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize); | |
1469 | ||
1470 | module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint, | |
1471 | &nf_conntrack_htable_size, 0600); | |
1472 | ||
1473 | void nf_ct_untracked_status_or(unsigned long bits) | |
1474 | { | |
1475 | int cpu; | |
1476 | ||
1477 | for_each_possible_cpu(cpu) | |
1478 | per_cpu(nf_conntrack_untracked, cpu).status |= bits; | |
1479 | } | |
1480 | EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or); | |
1481 | ||
1482 | int nf_conntrack_init_start(void) | |
1483 | { | |
1484 | int max_factor = 8; | |
1485 | int ret, cpu; | |
1486 | ||
1487 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1488 | * machine has 512 buckets. >= 1GB machines have 16384 buckets. */ | |
1489 | if (!nf_conntrack_htable_size) { | |
1490 | nf_conntrack_htable_size | |
1491 | = (((totalram_pages << PAGE_SHIFT) / 16384) | |
1492 | / sizeof(struct hlist_head)); | |
1493 | if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1494 | nf_conntrack_htable_size = 16384; | |
1495 | if (nf_conntrack_htable_size < 32) | |
1496 | nf_conntrack_htable_size = 32; | |
1497 | ||
1498 | /* Use a max. factor of four by default to get the same max as | |
1499 | * with the old struct list_heads. When a table size is given | |
1500 | * we use the old value of 8 to avoid reducing the max. | |
1501 | * entries. */ | |
1502 | max_factor = 4; | |
1503 | } | |
1504 | nf_conntrack_max = max_factor * nf_conntrack_htable_size; | |
1505 | ||
1506 | printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n", | |
1507 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1508 | nf_conntrack_max); | |
1509 | ||
1510 | ret = nf_conntrack_expect_init(); | |
1511 | if (ret < 0) | |
1512 | goto err_expect; | |
1513 | ||
1514 | ret = nf_conntrack_acct_init(); | |
1515 | if (ret < 0) | |
1516 | goto err_acct; | |
1517 | ||
1518 | ret = nf_conntrack_tstamp_init(); | |
1519 | if (ret < 0) | |
1520 | goto err_tstamp; | |
1521 | ||
1522 | ret = nf_conntrack_ecache_init(); | |
1523 | if (ret < 0) | |
1524 | goto err_ecache; | |
1525 | ||
1526 | ret = nf_conntrack_timeout_init(); | |
1527 | if (ret < 0) | |
1528 | goto err_timeout; | |
1529 | ||
1530 | ret = nf_conntrack_helper_init(); | |
1531 | if (ret < 0) | |
1532 | goto err_helper; | |
1533 | ||
1534 | ret = nf_conntrack_labels_init(); | |
1535 | if (ret < 0) | |
1536 | goto err_labels; | |
1537 | ||
1538 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
1539 | ret = nf_ct_extend_register(&nf_ct_zone_extend); | |
1540 | if (ret < 0) | |
1541 | goto err_extend; | |
1542 | #endif | |
1543 | /* Set up fake conntrack: to never be deleted, not in any hashes */ | |
1544 | for_each_possible_cpu(cpu) { | |
1545 | struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu); | |
1546 | write_pnet(&ct->ct_net, &init_net); | |
1547 | atomic_set(&ct->ct_general.use, 1); | |
1548 | } | |
1549 | /* - and look it like as a confirmed connection */ | |
1550 | nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED); | |
1551 | return 0; | |
1552 | ||
1553 | #ifdef CONFIG_NF_CONNTRACK_ZONES | |
1554 | err_extend: | |
1555 | nf_conntrack_labels_fini(); | |
1556 | #endif | |
1557 | err_labels: | |
1558 | nf_conntrack_helper_fini(); | |
1559 | err_helper: | |
1560 | nf_conntrack_timeout_fini(); | |
1561 | err_timeout: | |
1562 | nf_conntrack_ecache_fini(); | |
1563 | err_ecache: | |
1564 | nf_conntrack_tstamp_fini(); | |
1565 | err_tstamp: | |
1566 | nf_conntrack_acct_fini(); | |
1567 | err_acct: | |
1568 | nf_conntrack_expect_fini(); | |
1569 | err_expect: | |
1570 | return ret; | |
1571 | } | |
1572 | ||
1573 | void nf_conntrack_init_end(void) | |
1574 | { | |
1575 | /* For use by REJECT target */ | |
1576 | RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach); | |
1577 | RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack); | |
1578 | ||
1579 | /* Howto get NAT offsets */ | |
1580 | RCU_INIT_POINTER(nf_ct_nat_offset, NULL); | |
1581 | } | |
1582 | ||
1583 | /* | |
1584 | * We need to use special "null" values, not used in hash table | |
1585 | */ | |
1586 | #define UNCONFIRMED_NULLS_VAL ((1<<30)+0) | |
1587 | #define DYING_NULLS_VAL ((1<<30)+1) | |
1588 | #define TEMPLATE_NULLS_VAL ((1<<30)+2) | |
1589 | ||
1590 | int nf_conntrack_init_net(struct net *net) | |
1591 | { | |
1592 | int ret; | |
1593 | ||
1594 | atomic_set(&net->ct.count, 0); | |
1595 | INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL); | |
1596 | INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL); | |
1597 | INIT_HLIST_NULLS_HEAD(&net->ct.tmpl, TEMPLATE_NULLS_VAL); | |
1598 | net->ct.stat = alloc_percpu(struct ip_conntrack_stat); | |
1599 | if (!net->ct.stat) { | |
1600 | ret = -ENOMEM; | |
1601 | goto err_stat; | |
1602 | } | |
1603 | ||
1604 | net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net); | |
1605 | if (!net->ct.slabname) { | |
1606 | ret = -ENOMEM; | |
1607 | goto err_slabname; | |
1608 | } | |
1609 | ||
1610 | net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname, | |
1611 | sizeof(struct nf_conn), 0, | |
1612 | SLAB_DESTROY_BY_RCU, NULL); | |
1613 | if (!net->ct.nf_conntrack_cachep) { | |
1614 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); | |
1615 | ret = -ENOMEM; | |
1616 | goto err_cache; | |
1617 | } | |
1618 | ||
1619 | net->ct.htable_size = nf_conntrack_htable_size; | |
1620 | net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1); | |
1621 | if (!net->ct.hash) { | |
1622 | ret = -ENOMEM; | |
1623 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1624 | goto err_hash; | |
1625 | } | |
1626 | ret = nf_conntrack_expect_pernet_init(net); | |
1627 | if (ret < 0) | |
1628 | goto err_expect; | |
1629 | ret = nf_conntrack_acct_pernet_init(net); | |
1630 | if (ret < 0) | |
1631 | goto err_acct; | |
1632 | ret = nf_conntrack_tstamp_pernet_init(net); | |
1633 | if (ret < 0) | |
1634 | goto err_tstamp; | |
1635 | ret = nf_conntrack_ecache_pernet_init(net); | |
1636 | if (ret < 0) | |
1637 | goto err_ecache; | |
1638 | ret = nf_conntrack_helper_pernet_init(net); | |
1639 | if (ret < 0) | |
1640 | goto err_helper; | |
1641 | ret = nf_conntrack_proto_init(net); | |
1642 | if (ret < 0) | |
1643 | goto err_proto; | |
1644 | return 0; | |
1645 | ||
1646 | err_proto: | |
1647 | nf_conntrack_helper_pernet_fini(net); | |
1648 | err_helper: | |
1649 | nf_conntrack_ecache_pernet_fini(net); | |
1650 | err_ecache: | |
1651 | nf_conntrack_tstamp_pernet_fini(net); | |
1652 | err_tstamp: | |
1653 | nf_conntrack_acct_pernet_fini(net); | |
1654 | err_acct: | |
1655 | nf_conntrack_expect_pernet_fini(net); | |
1656 | err_expect: | |
1657 | nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); | |
1658 | err_hash: | |
1659 | kmem_cache_destroy(net->ct.nf_conntrack_cachep); | |
1660 | err_cache: | |
1661 | kfree(net->ct.slabname); | |
1662 | err_slabname: | |
1663 | free_percpu(net->ct.stat); | |
1664 | err_stat: | |
1665 | return ret; | |
1666 | } | |
1667 | ||
1668 | s16 (*nf_ct_nat_offset)(const struct nf_conn *ct, | |
1669 | enum ip_conntrack_dir dir, | |
1670 | u32 seq); | |
1671 | EXPORT_SYMBOL_GPL(nf_ct_nat_offset); |