Commit | Line | Data |
---|---|---|
9fb9cbb1 YK |
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) 2002-2005 Netfilter Core Team <coreteam@netfilter.org> | |
7 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * 23 Apr 2001: Harald Welte <laforge@gnumonks.org> | |
14 | * - new API and handling of conntrack/nat helpers | |
15 | * - now capable of multiple expectations for one master | |
16 | * 16 Jul 2002: Harald Welte <laforge@gnumonks.org> | |
17 | * - add usage/reference counts to ip_conntrack_expect | |
18 | * - export ip_conntrack[_expect]_{find_get,put} functions | |
19 | * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
20 | * - generalize L3 protocol denendent part. | |
21 | * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
22 | * - add support various size of conntrack structures. | |
23 | * | |
24 | * Derived from net/ipv4/netfilter/ip_conntrack_core.c | |
25 | */ | |
26 | ||
27 | #include <linux/config.h> | |
28 | #include <linux/types.h> | |
29 | #include <linux/netfilter.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/skbuff.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/vmalloc.h> | |
34 | #include <linux/stddef.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/random.h> | |
37 | #include <linux/jhash.h> | |
38 | #include <linux/err.h> | |
39 | #include <linux/percpu.h> | |
40 | #include <linux/moduleparam.h> | |
41 | #include <linux/notifier.h> | |
42 | #include <linux/kernel.h> | |
43 | #include <linux/netdevice.h> | |
44 | #include <linux/socket.h> | |
45 | ||
46 | /* This rwlock protects the main hash table, protocol/helper/expected | |
47 | registrations, conntrack timers*/ | |
48 | #define ASSERT_READ_LOCK(x) | |
49 | #define ASSERT_WRITE_LOCK(x) | |
50 | ||
51 | #include <net/netfilter/nf_conntrack.h> | |
52 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
53 | #include <net/netfilter/nf_conntrack_protocol.h> | |
54 | #include <net/netfilter/nf_conntrack_helper.h> | |
55 | #include <net/netfilter/nf_conntrack_core.h> | |
56 | #include <linux/netfilter_ipv4/listhelp.h> | |
57 | ||
58 | #define NF_CONNTRACK_VERSION "0.4.1" | |
59 | ||
60 | #if 0 | |
61 | #define DEBUGP printk | |
62 | #else | |
63 | #define DEBUGP(format, args...) | |
64 | #endif | |
65 | ||
66 | DEFINE_RWLOCK(nf_conntrack_lock); | |
67 | ||
68 | /* nf_conntrack_standalone needs this */ | |
69 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); | |
70 | ||
71 | void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; | |
72 | LIST_HEAD(nf_conntrack_expect_list); | |
73 | struct nf_conntrack_protocol **nf_ct_protos[PF_MAX]; | |
74 | struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX]; | |
75 | static LIST_HEAD(helpers); | |
76 | unsigned int nf_conntrack_htable_size = 0; | |
77 | int nf_conntrack_max; | |
78 | struct list_head *nf_conntrack_hash; | |
79 | static kmem_cache_t *nf_conntrack_expect_cachep; | |
80 | struct nf_conn nf_conntrack_untracked; | |
81 | unsigned int nf_ct_log_invalid; | |
82 | static LIST_HEAD(unconfirmed); | |
83 | static int nf_conntrack_vmalloc; | |
84 | ||
c1d10adb PNA |
85 | static unsigned int nf_conntrack_next_id = 1; |
86 | static unsigned int nf_conntrack_expect_next_id = 1; | |
9fb9cbb1 YK |
87 | #ifdef CONFIG_NF_CONNTRACK_EVENTS |
88 | struct notifier_block *nf_conntrack_chain; | |
89 | struct notifier_block *nf_conntrack_expect_chain; | |
90 | ||
91 | DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); | |
92 | ||
93 | /* deliver cached events and clear cache entry - must be called with locally | |
94 | * disabled softirqs */ | |
95 | static inline void | |
96 | __nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) | |
97 | { | |
98 | DEBUGP("ecache: delivering events for %p\n", ecache->ct); | |
99 | if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) | |
100 | && ecache->events) | |
101 | notifier_call_chain(&nf_conntrack_chain, ecache->events, | |
102 | ecache->ct); | |
103 | ||
104 | ecache->events = 0; | |
105 | nf_ct_put(ecache->ct); | |
106 | ecache->ct = NULL; | |
107 | } | |
108 | ||
109 | /* Deliver all cached events for a particular conntrack. This is called | |
110 | * by code prior to async packet handling for freeing the skb */ | |
111 | void nf_ct_deliver_cached_events(const struct nf_conn *ct) | |
112 | { | |
113 | struct nf_conntrack_ecache *ecache; | |
114 | ||
115 | local_bh_disable(); | |
116 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
117 | if (ecache->ct == ct) | |
118 | __nf_ct_deliver_cached_events(ecache); | |
119 | local_bh_enable(); | |
120 | } | |
121 | ||
122 | /* Deliver cached events for old pending events, if current conntrack != old */ | |
123 | void __nf_ct_event_cache_init(struct nf_conn *ct) | |
124 | { | |
125 | struct nf_conntrack_ecache *ecache; | |
126 | ||
127 | /* take care of delivering potentially old events */ | |
128 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
129 | BUG_ON(ecache->ct == ct); | |
130 | if (ecache->ct) | |
131 | __nf_ct_deliver_cached_events(ecache); | |
132 | /* initialize for this conntrack/packet */ | |
133 | ecache->ct = ct; | |
134 | nf_conntrack_get(&ct->ct_general); | |
135 | } | |
136 | ||
137 | /* flush the event cache - touches other CPU's data and must not be called | |
138 | * while packets are still passing through the code */ | |
139 | static void nf_ct_event_cache_flush(void) | |
140 | { | |
141 | struct nf_conntrack_ecache *ecache; | |
142 | int cpu; | |
143 | ||
144 | for_each_cpu(cpu) { | |
145 | ecache = &per_cpu(nf_conntrack_ecache, cpu); | |
146 | if (ecache->ct) | |
147 | nf_ct_put(ecache->ct); | |
148 | } | |
149 | } | |
150 | #else | |
151 | static inline void nf_ct_event_cache_flush(void) {} | |
152 | #endif /* CONFIG_NF_CONNTRACK_EVENTS */ | |
153 | ||
154 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); | |
155 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); | |
156 | ||
157 | /* | |
158 | * This scheme offers various size of "struct nf_conn" dependent on | |
159 | * features(helper, nat, ...) | |
160 | */ | |
161 | ||
162 | #define NF_CT_FEATURES_NAMELEN 256 | |
163 | static struct { | |
164 | /* name of slab cache. printed in /proc/slabinfo */ | |
165 | char *name; | |
166 | ||
167 | /* size of slab cache */ | |
168 | size_t size; | |
169 | ||
170 | /* slab cache pointer */ | |
171 | kmem_cache_t *cachep; | |
172 | ||
173 | /* allocated slab cache + modules which uses this slab cache */ | |
174 | int use; | |
175 | ||
176 | /* Initialization */ | |
177 | int (*init_conntrack)(struct nf_conn *, u_int32_t); | |
178 | ||
179 | } nf_ct_cache[NF_CT_F_NUM]; | |
180 | ||
181 | /* protect members of nf_ct_cache except of "use" */ | |
182 | DEFINE_RWLOCK(nf_ct_cache_lock); | |
183 | ||
184 | /* This avoids calling kmem_cache_create() with same name simultaneously */ | |
185 | DECLARE_MUTEX(nf_ct_cache_mutex); | |
186 | ||
187 | extern struct nf_conntrack_protocol nf_conntrack_generic_protocol; | |
188 | struct nf_conntrack_protocol * | |
c1d10adb | 189 | __nf_ct_proto_find(u_int16_t l3proto, u_int8_t protocol) |
9fb9cbb1 | 190 | { |
ddc8d029 | 191 | if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL)) |
9fb9cbb1 YK |
192 | return &nf_conntrack_generic_protocol; |
193 | ||
194 | return nf_ct_protos[l3proto][protocol]; | |
195 | } | |
196 | ||
c1d10adb PNA |
197 | /* this is guaranteed to always return a valid protocol helper, since |
198 | * it falls back to generic_protocol */ | |
199 | struct nf_conntrack_protocol * | |
200 | nf_ct_proto_find_get(u_int16_t l3proto, u_int8_t protocol) | |
201 | { | |
202 | struct nf_conntrack_protocol *p; | |
203 | ||
204 | preempt_disable(); | |
205 | p = __nf_ct_proto_find(l3proto, protocol); | |
206 | if (p) { | |
207 | if (!try_module_get(p->me)) | |
208 | p = &nf_conntrack_generic_protocol; | |
209 | } | |
210 | preempt_enable(); | |
211 | ||
212 | return p; | |
213 | } | |
214 | ||
215 | void nf_ct_proto_put(struct nf_conntrack_protocol *p) | |
216 | { | |
217 | module_put(p->me); | |
218 | } | |
219 | ||
220 | struct nf_conntrack_l3proto * | |
221 | nf_ct_l3proto_find_get(u_int16_t l3proto) | |
222 | { | |
223 | struct nf_conntrack_l3proto *p; | |
224 | ||
225 | preempt_disable(); | |
226 | p = __nf_ct_l3proto_find(l3proto); | |
227 | if (p) { | |
228 | if (!try_module_get(p->me)) | |
229 | p = &nf_conntrack_generic_l3proto; | |
230 | } | |
231 | preempt_enable(); | |
232 | ||
233 | return p; | |
234 | } | |
235 | ||
236 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
237 | { | |
238 | module_put(p->me); | |
239 | } | |
240 | ||
9fb9cbb1 YK |
241 | static int nf_conntrack_hash_rnd_initted; |
242 | static unsigned int nf_conntrack_hash_rnd; | |
243 | ||
244 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
245 | unsigned int size, unsigned int rnd) | |
246 | { | |
247 | unsigned int a, b; | |
248 | a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), | |
249 | ((tuple->src.l3num) << 16) | tuple->dst.protonum); | |
250 | b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), | |
251 | (tuple->src.u.all << 16) | tuple->dst.u.all); | |
252 | ||
253 | return jhash_2words(a, b, rnd) % size; | |
254 | } | |
255 | ||
256 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) | |
257 | { | |
258 | return __hash_conntrack(tuple, nf_conntrack_htable_size, | |
259 | nf_conntrack_hash_rnd); | |
260 | } | |
261 | ||
262 | /* Initialize "struct nf_conn" which has spaces for helper */ | |
263 | static int | |
264 | init_conntrack_for_helper(struct nf_conn *conntrack, u_int32_t features) | |
265 | { | |
266 | ||
267 | conntrack->help = (union nf_conntrack_help *) | |
268 | (((unsigned long)conntrack->data | |
269 | + (__alignof__(union nf_conntrack_help) - 1)) | |
270 | & (~((unsigned long)(__alignof__(union nf_conntrack_help) -1)))); | |
271 | return 0; | |
272 | } | |
273 | ||
274 | int nf_conntrack_register_cache(u_int32_t features, const char *name, | |
275 | size_t size, | |
276 | int (*init)(struct nf_conn *, u_int32_t)) | |
277 | { | |
278 | int ret = 0; | |
279 | char *cache_name; | |
280 | kmem_cache_t *cachep; | |
281 | ||
282 | DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", | |
283 | features, name, size); | |
284 | ||
285 | if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { | |
286 | DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", | |
287 | features); | |
288 | return -EINVAL; | |
289 | } | |
290 | ||
291 | down(&nf_ct_cache_mutex); | |
292 | ||
293 | write_lock_bh(&nf_ct_cache_lock); | |
294 | /* e.g: multiple helpers are loaded */ | |
295 | if (nf_ct_cache[features].use > 0) { | |
296 | DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); | |
297 | if ((!strncmp(nf_ct_cache[features].name, name, | |
298 | NF_CT_FEATURES_NAMELEN)) | |
299 | && nf_ct_cache[features].size == size | |
300 | && nf_ct_cache[features].init_conntrack == init) { | |
301 | DEBUGP("nf_conntrack_register_cache: reusing.\n"); | |
302 | nf_ct_cache[features].use++; | |
303 | ret = 0; | |
304 | } else | |
305 | ret = -EBUSY; | |
306 | ||
307 | write_unlock_bh(&nf_ct_cache_lock); | |
308 | up(&nf_ct_cache_mutex); | |
309 | return ret; | |
310 | } | |
311 | write_unlock_bh(&nf_ct_cache_lock); | |
312 | ||
313 | /* | |
314 | * The memory space for name of slab cache must be alive until | |
315 | * cache is destroyed. | |
316 | */ | |
317 | cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); | |
318 | if (cache_name == NULL) { | |
319 | DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); | |
320 | ret = -ENOMEM; | |
321 | goto out_up_mutex; | |
322 | } | |
323 | ||
324 | if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) | |
325 | >= NF_CT_FEATURES_NAMELEN) { | |
326 | printk("nf_conntrack_register_cache: name too long\n"); | |
327 | ret = -EINVAL; | |
328 | goto out_free_name; | |
329 | } | |
330 | ||
331 | cachep = kmem_cache_create(cache_name, size, 0, 0, | |
332 | NULL, NULL); | |
333 | if (!cachep) { | |
334 | printk("nf_conntrack_register_cache: Can't create slab cache " | |
335 | "for the features = 0x%x\n", features); | |
336 | ret = -ENOMEM; | |
337 | goto out_free_name; | |
338 | } | |
339 | ||
340 | write_lock_bh(&nf_ct_cache_lock); | |
341 | nf_ct_cache[features].use = 1; | |
342 | nf_ct_cache[features].size = size; | |
343 | nf_ct_cache[features].init_conntrack = init; | |
344 | nf_ct_cache[features].cachep = cachep; | |
345 | nf_ct_cache[features].name = cache_name; | |
346 | write_unlock_bh(&nf_ct_cache_lock); | |
347 | ||
348 | goto out_up_mutex; | |
349 | ||
350 | out_free_name: | |
351 | kfree(cache_name); | |
352 | out_up_mutex: | |
353 | up(&nf_ct_cache_mutex); | |
354 | return ret; | |
355 | } | |
356 | ||
357 | /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ | |
358 | void nf_conntrack_unregister_cache(u_int32_t features) | |
359 | { | |
360 | kmem_cache_t *cachep; | |
361 | char *name; | |
362 | ||
363 | /* | |
364 | * This assures that kmem_cache_create() isn't called before destroying | |
365 | * slab cache. | |
366 | */ | |
367 | DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); | |
368 | down(&nf_ct_cache_mutex); | |
369 | ||
370 | write_lock_bh(&nf_ct_cache_lock); | |
371 | if (--nf_ct_cache[features].use > 0) { | |
372 | write_unlock_bh(&nf_ct_cache_lock); | |
373 | up(&nf_ct_cache_mutex); | |
374 | return; | |
375 | } | |
376 | cachep = nf_ct_cache[features].cachep; | |
377 | name = nf_ct_cache[features].name; | |
378 | nf_ct_cache[features].cachep = NULL; | |
379 | nf_ct_cache[features].name = NULL; | |
380 | nf_ct_cache[features].init_conntrack = NULL; | |
381 | nf_ct_cache[features].size = 0; | |
382 | write_unlock_bh(&nf_ct_cache_lock); | |
383 | ||
384 | synchronize_net(); | |
385 | ||
386 | kmem_cache_destroy(cachep); | |
387 | kfree(name); | |
388 | ||
389 | up(&nf_ct_cache_mutex); | |
390 | } | |
391 | ||
392 | int | |
393 | nf_ct_get_tuple(const struct sk_buff *skb, | |
394 | unsigned int nhoff, | |
395 | unsigned int dataoff, | |
396 | u_int16_t l3num, | |
397 | u_int8_t protonum, | |
398 | struct nf_conntrack_tuple *tuple, | |
399 | const struct nf_conntrack_l3proto *l3proto, | |
400 | const struct nf_conntrack_protocol *protocol) | |
401 | { | |
402 | NF_CT_TUPLE_U_BLANK(tuple); | |
403 | ||
404 | tuple->src.l3num = l3num; | |
405 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
406 | return 0; | |
407 | ||
408 | tuple->dst.protonum = protonum; | |
409 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
410 | ||
411 | return protocol->pkt_to_tuple(skb, dataoff, tuple); | |
412 | } | |
413 | ||
414 | int | |
415 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
416 | const struct nf_conntrack_tuple *orig, | |
417 | const struct nf_conntrack_l3proto *l3proto, | |
418 | const struct nf_conntrack_protocol *protocol) | |
419 | { | |
420 | NF_CT_TUPLE_U_BLANK(inverse); | |
421 | ||
422 | inverse->src.l3num = orig->src.l3num; | |
423 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
424 | return 0; | |
425 | ||
426 | inverse->dst.dir = !orig->dst.dir; | |
427 | ||
428 | inverse->dst.protonum = orig->dst.protonum; | |
429 | return protocol->invert_tuple(inverse, orig); | |
430 | } | |
431 | ||
432 | /* nf_conntrack_expect helper functions */ | |
c1d10adb | 433 | void nf_ct_unlink_expect(struct nf_conntrack_expect *exp) |
9fb9cbb1 YK |
434 | { |
435 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); | |
4a59a810 | 436 | NF_CT_ASSERT(!timer_pending(&exp->timeout)); |
9fb9cbb1 YK |
437 | list_del(&exp->list); |
438 | NF_CT_STAT_INC(expect_delete); | |
439 | exp->master->expecting--; | |
440 | nf_conntrack_expect_put(exp); | |
441 | } | |
442 | ||
443 | static void expectation_timed_out(unsigned long ul_expect) | |
444 | { | |
445 | struct nf_conntrack_expect *exp = (void *)ul_expect; | |
446 | ||
447 | write_lock_bh(&nf_conntrack_lock); | |
448 | nf_ct_unlink_expect(exp); | |
449 | write_unlock_bh(&nf_conntrack_lock); | |
450 | nf_conntrack_expect_put(exp); | |
451 | } | |
452 | ||
c1d10adb PNA |
453 | struct nf_conntrack_expect * |
454 | __nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) | |
455 | { | |
456 | struct nf_conntrack_expect *i; | |
457 | ||
458 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
459 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) { | |
460 | atomic_inc(&i->use); | |
461 | return i; | |
462 | } | |
463 | } | |
464 | return NULL; | |
465 | } | |
466 | ||
467 | /* Just find a expectation corresponding to a tuple. */ | |
468 | struct nf_conntrack_expect * | |
469 | nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) | |
470 | { | |
471 | struct nf_conntrack_expect *i; | |
472 | ||
473 | read_lock_bh(&nf_conntrack_lock); | |
474 | i = __nf_conntrack_expect_find(tuple); | |
475 | read_unlock_bh(&nf_conntrack_lock); | |
476 | ||
477 | return i; | |
478 | } | |
479 | ||
9fb9cbb1 YK |
480 | /* If an expectation for this connection is found, it gets delete from |
481 | * global list then returned. */ | |
482 | static struct nf_conntrack_expect * | |
483 | find_expectation(const struct nf_conntrack_tuple *tuple) | |
484 | { | |
485 | struct nf_conntrack_expect *i; | |
486 | ||
487 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
488 | /* If master is not in hash table yet (ie. packet hasn't left | |
489 | this machine yet), how can other end know about expected? | |
490 | Hence these are not the droids you are looking for (if | |
491 | master ct never got confirmed, we'd hold a reference to it | |
492 | and weird things would happen to future packets). */ | |
493 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) | |
494 | && nf_ct_is_confirmed(i->master)) { | |
495 | if (i->flags & NF_CT_EXPECT_PERMANENT) { | |
496 | atomic_inc(&i->use); | |
497 | return i; | |
498 | } else if (del_timer(&i->timeout)) { | |
499 | nf_ct_unlink_expect(i); | |
500 | return i; | |
501 | } | |
502 | } | |
503 | } | |
504 | return NULL; | |
505 | } | |
506 | ||
507 | /* delete all expectations for this conntrack */ | |
c1d10adb | 508 | void nf_ct_remove_expectations(struct nf_conn *ct) |
9fb9cbb1 YK |
509 | { |
510 | struct nf_conntrack_expect *i, *tmp; | |
511 | ||
512 | /* Optimization: most connection never expect any others. */ | |
513 | if (ct->expecting == 0) | |
514 | return; | |
515 | ||
516 | list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) { | |
517 | if (i->master == ct && del_timer(&i->timeout)) { | |
518 | nf_ct_unlink_expect(i); | |
519 | nf_conntrack_expect_put(i); | |
520 | } | |
521 | } | |
522 | } | |
523 | ||
524 | static void | |
525 | clean_from_lists(struct nf_conn *ct) | |
526 | { | |
527 | unsigned int ho, hr; | |
528 | ||
529 | DEBUGP("clean_from_lists(%p)\n", ct); | |
530 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); | |
531 | ||
532 | ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
533 | hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
534 | LIST_DELETE(&nf_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]); | |
535 | LIST_DELETE(&nf_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]); | |
536 | ||
537 | /* Destroy all pending expectations */ | |
c1d10adb | 538 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
539 | } |
540 | ||
541 | static void | |
542 | destroy_conntrack(struct nf_conntrack *nfct) | |
543 | { | |
544 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
545 | struct nf_conntrack_l3proto *l3proto; | |
546 | struct nf_conntrack_protocol *proto; | |
547 | ||
548 | DEBUGP("destroy_conntrack(%p)\n", ct); | |
549 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); | |
550 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
551 | ||
552 | nf_conntrack_event(IPCT_DESTROY, ct); | |
553 | set_bit(IPS_DYING_BIT, &ct->status); | |
554 | ||
555 | /* To make sure we don't get any weird locking issues here: | |
556 | * destroy_conntrack() MUST NOT be called with a write lock | |
557 | * to nf_conntrack_lock!!! -HW */ | |
c1d10adb | 558 | l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); |
9fb9cbb1 YK |
559 | if (l3proto && l3proto->destroy) |
560 | l3proto->destroy(ct); | |
561 | ||
c1d10adb | 562 | proto = __nf_ct_proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); |
9fb9cbb1 YK |
563 | if (proto && proto->destroy) |
564 | proto->destroy(ct); | |
565 | ||
566 | if (nf_conntrack_destroyed) | |
567 | nf_conntrack_destroyed(ct); | |
568 | ||
569 | write_lock_bh(&nf_conntrack_lock); | |
570 | /* Expectations will have been removed in clean_from_lists, | |
571 | * except TFTP can create an expectation on the first packet, | |
572 | * before connection is in the list, so we need to clean here, | |
573 | * too. */ | |
c1d10adb | 574 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
575 | |
576 | /* We overload first tuple to link into unconfirmed list. */ | |
577 | if (!nf_ct_is_confirmed(ct)) { | |
578 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); | |
579 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
580 | } | |
581 | ||
582 | NF_CT_STAT_INC(delete); | |
583 | write_unlock_bh(&nf_conntrack_lock); | |
584 | ||
585 | if (ct->master) | |
586 | nf_ct_put(ct->master); | |
587 | ||
588 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); | |
589 | nf_conntrack_free(ct); | |
590 | } | |
591 | ||
592 | static void death_by_timeout(unsigned long ul_conntrack) | |
593 | { | |
594 | struct nf_conn *ct = (void *)ul_conntrack; | |
595 | ||
596 | write_lock_bh(&nf_conntrack_lock); | |
597 | /* Inside lock so preempt is disabled on module removal path. | |
598 | * Otherwise we can get spurious warnings. */ | |
599 | NF_CT_STAT_INC(delete_list); | |
600 | clean_from_lists(ct); | |
601 | write_unlock_bh(&nf_conntrack_lock); | |
602 | nf_ct_put(ct); | |
603 | } | |
604 | ||
605 | static inline int | |
606 | conntrack_tuple_cmp(const struct nf_conntrack_tuple_hash *i, | |
607 | const struct nf_conntrack_tuple *tuple, | |
608 | const struct nf_conn *ignored_conntrack) | |
609 | { | |
610 | ASSERT_READ_LOCK(&nf_conntrack_lock); | |
611 | return nf_ct_tuplehash_to_ctrack(i) != ignored_conntrack | |
612 | && nf_ct_tuple_equal(tuple, &i->tuple); | |
613 | } | |
614 | ||
c1d10adb | 615 | struct nf_conntrack_tuple_hash * |
9fb9cbb1 YK |
616 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
617 | const struct nf_conn *ignored_conntrack) | |
618 | { | |
619 | struct nf_conntrack_tuple_hash *h; | |
620 | unsigned int hash = hash_conntrack(tuple); | |
621 | ||
622 | ASSERT_READ_LOCK(&nf_conntrack_lock); | |
623 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) { | |
624 | if (conntrack_tuple_cmp(h, tuple, ignored_conntrack)) { | |
625 | NF_CT_STAT_INC(found); | |
626 | return h; | |
627 | } | |
628 | NF_CT_STAT_INC(searched); | |
629 | } | |
630 | ||
631 | return NULL; | |
632 | } | |
633 | ||
634 | /* Find a connection corresponding to a tuple. */ | |
635 | struct nf_conntrack_tuple_hash * | |
636 | nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, | |
637 | const struct nf_conn *ignored_conntrack) | |
638 | { | |
639 | struct nf_conntrack_tuple_hash *h; | |
640 | ||
641 | read_lock_bh(&nf_conntrack_lock); | |
642 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
643 | if (h) | |
644 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
645 | read_unlock_bh(&nf_conntrack_lock); | |
646 | ||
647 | return h; | |
648 | } | |
649 | ||
c1d10adb PNA |
650 | static void __nf_conntrack_hash_insert(struct nf_conn *ct, |
651 | unsigned int hash, | |
652 | unsigned int repl_hash) | |
653 | { | |
654 | ct->id = ++nf_conntrack_next_id; | |
655 | list_prepend(&nf_conntrack_hash[hash], | |
656 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
657 | list_prepend(&nf_conntrack_hash[repl_hash], | |
658 | &ct->tuplehash[IP_CT_DIR_REPLY].list); | |
659 | } | |
660 | ||
661 | void nf_conntrack_hash_insert(struct nf_conn *ct) | |
662 | { | |
663 | unsigned int hash, repl_hash; | |
664 | ||
665 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
666 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
667 | ||
668 | write_lock_bh(&nf_conntrack_lock); | |
669 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
670 | write_unlock_bh(&nf_conntrack_lock); | |
671 | } | |
672 | ||
9fb9cbb1 YK |
673 | /* Confirm a connection given skb; places it in hash table */ |
674 | int | |
675 | __nf_conntrack_confirm(struct sk_buff **pskb) | |
676 | { | |
677 | unsigned int hash, repl_hash; | |
678 | struct nf_conn *ct; | |
679 | enum ip_conntrack_info ctinfo; | |
680 | ||
681 | ct = nf_ct_get(*pskb, &ctinfo); | |
682 | ||
683 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
684 | ICMP/TCP RST packets in other direction. Actual packet | |
685 | which created connection will be IP_CT_NEW or for an | |
686 | expected connection, IP_CT_RELATED. */ | |
687 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
688 | return NF_ACCEPT; | |
689 | ||
690 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
691 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
692 | ||
693 | /* We're not in hash table, and we refuse to set up related | |
694 | connections for unconfirmed conns. But packet copies and | |
695 | REJECT will give spurious warnings here. */ | |
696 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
697 | ||
698 | /* No external references means noone else could have | |
699 | confirmed us. */ | |
700 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
701 | DEBUGP("Confirming conntrack %p\n", ct); | |
702 | ||
703 | write_lock_bh(&nf_conntrack_lock); | |
704 | ||
705 | /* See if there's one in the list already, including reverse: | |
706 | NAT could have grabbed it without realizing, since we're | |
707 | not in the hash. If there is, we lost race. */ | |
708 | if (!LIST_FIND(&nf_conntrack_hash[hash], | |
709 | conntrack_tuple_cmp, | |
710 | struct nf_conntrack_tuple_hash *, | |
711 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL) | |
712 | && !LIST_FIND(&nf_conntrack_hash[repl_hash], | |
713 | conntrack_tuple_cmp, | |
714 | struct nf_conntrack_tuple_hash *, | |
715 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) { | |
716 | /* Remove from unconfirmed list */ | |
717 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
718 | ||
c1d10adb | 719 | __nf_conntrack_hash_insert(ct, hash, repl_hash); |
9fb9cbb1 YK |
720 | /* Timer relative to confirmation time, not original |
721 | setting time, otherwise we'd get timer wrap in | |
722 | weird delay cases. */ | |
723 | ct->timeout.expires += jiffies; | |
724 | add_timer(&ct->timeout); | |
725 | atomic_inc(&ct->ct_general.use); | |
726 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
727 | NF_CT_STAT_INC(insert); | |
728 | write_unlock_bh(&nf_conntrack_lock); | |
729 | if (ct->helper) | |
730 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); | |
731 | #ifdef CONFIG_NF_NAT_NEEDED | |
732 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || | |
733 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
734 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
735 | #endif | |
736 | nf_conntrack_event_cache(master_ct(ct) ? | |
737 | IPCT_RELATED : IPCT_NEW, *pskb); | |
738 | return NF_ACCEPT; | |
739 | } | |
740 | ||
741 | NF_CT_STAT_INC(insert_failed); | |
742 | write_unlock_bh(&nf_conntrack_lock); | |
743 | return NF_DROP; | |
744 | } | |
745 | ||
746 | /* Returns true if a connection correspondings to the tuple (required | |
747 | for NAT). */ | |
748 | int | |
749 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
750 | const struct nf_conn *ignored_conntrack) | |
751 | { | |
752 | struct nf_conntrack_tuple_hash *h; | |
753 | ||
754 | read_lock_bh(&nf_conntrack_lock); | |
755 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
756 | read_unlock_bh(&nf_conntrack_lock); | |
757 | ||
758 | return h != NULL; | |
759 | } | |
760 | ||
761 | /* There's a small race here where we may free a just-assured | |
762 | connection. Too bad: we're in trouble anyway. */ | |
763 | static inline int unreplied(const struct nf_conntrack_tuple_hash *i) | |
764 | { | |
765 | return !(test_bit(IPS_ASSURED_BIT, | |
766 | &nf_ct_tuplehash_to_ctrack(i)->status)); | |
767 | } | |
768 | ||
769 | static int early_drop(struct list_head *chain) | |
770 | { | |
771 | /* Traverse backwards: gives us oldest, which is roughly LRU */ | |
772 | struct nf_conntrack_tuple_hash *h; | |
773 | struct nf_conn *ct = NULL; | |
774 | int dropped = 0; | |
775 | ||
776 | read_lock_bh(&nf_conntrack_lock); | |
777 | h = LIST_FIND_B(chain, unreplied, struct nf_conntrack_tuple_hash *); | |
778 | if (h) { | |
779 | ct = nf_ct_tuplehash_to_ctrack(h); | |
780 | atomic_inc(&ct->ct_general.use); | |
781 | } | |
782 | read_unlock_bh(&nf_conntrack_lock); | |
783 | ||
784 | if (!ct) | |
785 | return dropped; | |
786 | ||
787 | if (del_timer(&ct->timeout)) { | |
788 | death_by_timeout((unsigned long)ct); | |
789 | dropped = 1; | |
790 | NF_CT_STAT_INC(early_drop); | |
791 | } | |
792 | nf_ct_put(ct); | |
793 | return dropped; | |
794 | } | |
795 | ||
796 | static inline int helper_cmp(const struct nf_conntrack_helper *i, | |
797 | const struct nf_conntrack_tuple *rtuple) | |
798 | { | |
799 | return nf_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask); | |
800 | } | |
801 | ||
802 | static struct nf_conntrack_helper * | |
c1d10adb | 803 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
9fb9cbb1 YK |
804 | { |
805 | return LIST_FIND(&helpers, helper_cmp, | |
806 | struct nf_conntrack_helper *, | |
807 | tuple); | |
808 | } | |
809 | ||
c1d10adb PNA |
810 | struct nf_conntrack_helper * |
811 | nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple) | |
812 | { | |
813 | struct nf_conntrack_helper *helper; | |
814 | ||
815 | /* need nf_conntrack_lock to assure that helper exists until | |
816 | * try_module_get() is called */ | |
817 | read_lock_bh(&nf_conntrack_lock); | |
818 | ||
819 | helper = __nf_ct_helper_find(tuple); | |
820 | if (helper) { | |
821 | /* need to increase module usage count to assure helper will | |
822 | * not go away while the caller is e.g. busy putting a | |
823 | * conntrack in the hash that uses the helper */ | |
824 | if (!try_module_get(helper->me)) | |
825 | helper = NULL; | |
826 | } | |
827 | ||
828 | read_unlock_bh(&nf_conntrack_lock); | |
829 | ||
830 | return helper; | |
831 | } | |
832 | ||
833 | void nf_ct_helper_put(struct nf_conntrack_helper *helper) | |
834 | { | |
835 | module_put(helper->me); | |
836 | } | |
837 | ||
9fb9cbb1 YK |
838 | static struct nf_conn * |
839 | __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
840 | const struct nf_conntrack_tuple *repl, | |
841 | const struct nf_conntrack_l3proto *l3proto) | |
842 | { | |
843 | struct nf_conn *conntrack = NULL; | |
844 | u_int32_t features = 0; | |
845 | ||
846 | if (!nf_conntrack_hash_rnd_initted) { | |
847 | get_random_bytes(&nf_conntrack_hash_rnd, 4); | |
848 | nf_conntrack_hash_rnd_initted = 1; | |
849 | } | |
850 | ||
851 | if (nf_conntrack_max | |
852 | && atomic_read(&nf_conntrack_count) >= nf_conntrack_max) { | |
853 | unsigned int hash = hash_conntrack(orig); | |
854 | /* Try dropping from this hash chain. */ | |
855 | if (!early_drop(&nf_conntrack_hash[hash])) { | |
856 | if (net_ratelimit()) | |
857 | printk(KERN_WARNING | |
858 | "nf_conntrack: table full, dropping" | |
859 | " packet.\n"); | |
860 | return ERR_PTR(-ENOMEM); | |
861 | } | |
862 | } | |
863 | ||
864 | /* find features needed by this conntrack. */ | |
865 | features = l3proto->get_features(orig); | |
866 | read_lock_bh(&nf_conntrack_lock); | |
c1d10adb | 867 | if (__nf_ct_helper_find(repl) != NULL) |
9fb9cbb1 YK |
868 | features |= NF_CT_F_HELP; |
869 | read_unlock_bh(&nf_conntrack_lock); | |
870 | ||
871 | DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); | |
872 | ||
873 | read_lock_bh(&nf_ct_cache_lock); | |
874 | ||
875 | if (!nf_ct_cache[features].use) { | |
876 | DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", | |
877 | features); | |
878 | goto out; | |
879 | } | |
880 | ||
881 | conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); | |
882 | if (conntrack == NULL) { | |
883 | DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); | |
884 | goto out; | |
885 | } | |
886 | ||
887 | memset(conntrack, 0, nf_ct_cache[features].size); | |
888 | conntrack->features = features; | |
889 | if (nf_ct_cache[features].init_conntrack && | |
890 | nf_ct_cache[features].init_conntrack(conntrack, features) < 0) { | |
891 | DEBUGP("nf_conntrack_alloc: failed to init\n"); | |
892 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); | |
893 | conntrack = NULL; | |
894 | goto out; | |
895 | } | |
896 | ||
897 | atomic_set(&conntrack->ct_general.use, 1); | |
898 | conntrack->ct_general.destroy = destroy_conntrack; | |
899 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; | |
900 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
901 | /* Don't set timer yet: wait for confirmation */ | |
902 | init_timer(&conntrack->timeout); | |
903 | conntrack->timeout.data = (unsigned long)conntrack; | |
904 | conntrack->timeout.function = death_by_timeout; | |
905 | ||
906 | atomic_inc(&nf_conntrack_count); | |
907 | out: | |
908 | read_unlock_bh(&nf_ct_cache_lock); | |
909 | return conntrack; | |
910 | } | |
911 | ||
912 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
913 | const struct nf_conntrack_tuple *repl) | |
914 | { | |
915 | struct nf_conntrack_l3proto *l3proto; | |
916 | ||
c1d10adb | 917 | l3proto = __nf_ct_l3proto_find(orig->src.l3num); |
9fb9cbb1 YK |
918 | return __nf_conntrack_alloc(orig, repl, l3proto); |
919 | } | |
920 | ||
921 | void nf_conntrack_free(struct nf_conn *conntrack) | |
922 | { | |
923 | u_int32_t features = conntrack->features; | |
924 | NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); | |
925 | DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, | |
926 | conntrack); | |
927 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); | |
928 | atomic_dec(&nf_conntrack_count); | |
929 | } | |
930 | ||
931 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
932 | failed due to stress. Otherwise it really is unclassifiable. */ | |
933 | static struct nf_conntrack_tuple_hash * | |
934 | init_conntrack(const struct nf_conntrack_tuple *tuple, | |
935 | struct nf_conntrack_l3proto *l3proto, | |
936 | struct nf_conntrack_protocol *protocol, | |
937 | struct sk_buff *skb, | |
938 | unsigned int dataoff) | |
939 | { | |
940 | struct nf_conn *conntrack; | |
941 | struct nf_conntrack_tuple repl_tuple; | |
942 | struct nf_conntrack_expect *exp; | |
943 | ||
944 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, protocol)) { | |
945 | DEBUGP("Can't invert tuple.\n"); | |
946 | return NULL; | |
947 | } | |
948 | ||
949 | conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto); | |
950 | if (conntrack == NULL || IS_ERR(conntrack)) { | |
951 | DEBUGP("Can't allocate conntrack.\n"); | |
952 | return (struct nf_conntrack_tuple_hash *)conntrack; | |
953 | } | |
954 | ||
955 | if (!protocol->new(conntrack, skb, dataoff)) { | |
956 | nf_conntrack_free(conntrack); | |
957 | DEBUGP("init conntrack: can't track with proto module\n"); | |
958 | return NULL; | |
959 | } | |
960 | ||
961 | write_lock_bh(&nf_conntrack_lock); | |
962 | exp = find_expectation(tuple); | |
963 | ||
964 | if (exp) { | |
965 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", | |
966 | conntrack, exp); | |
967 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
968 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
969 | conntrack->master = exp->master; | |
970 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
971 | conntrack->mark = exp->master->mark; | |
972 | #endif | |
973 | nf_conntrack_get(&conntrack->master->ct_general); | |
974 | NF_CT_STAT_INC(expect_new); | |
975 | } else { | |
c1d10adb | 976 | conntrack->helper = __nf_ct_helper_find(&repl_tuple); |
9fb9cbb1 YK |
977 | |
978 | NF_CT_STAT_INC(new); | |
979 | } | |
980 | ||
981 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
982 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); | |
983 | ||
984 | write_unlock_bh(&nf_conntrack_lock); | |
985 | ||
986 | if (exp) { | |
987 | if (exp->expectfn) | |
988 | exp->expectfn(conntrack, exp); | |
989 | nf_conntrack_expect_put(exp); | |
990 | } | |
991 | ||
992 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
993 | } | |
994 | ||
995 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
996 | static inline struct nf_conn * | |
997 | resolve_normal_ct(struct sk_buff *skb, | |
998 | unsigned int dataoff, | |
999 | u_int16_t l3num, | |
1000 | u_int8_t protonum, | |
1001 | struct nf_conntrack_l3proto *l3proto, | |
1002 | struct nf_conntrack_protocol *proto, | |
1003 | int *set_reply, | |
1004 | enum ip_conntrack_info *ctinfo) | |
1005 | { | |
1006 | struct nf_conntrack_tuple tuple; | |
1007 | struct nf_conntrack_tuple_hash *h; | |
1008 | struct nf_conn *ct; | |
1009 | ||
1010 | if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), | |
1011 | dataoff, l3num, protonum, &tuple, l3proto, | |
1012 | proto)) { | |
1013 | DEBUGP("resolve_normal_ct: Can't get tuple\n"); | |
1014 | return NULL; | |
1015 | } | |
1016 | ||
1017 | /* look for tuple match */ | |
1018 | h = nf_conntrack_find_get(&tuple, NULL); | |
1019 | if (!h) { | |
1020 | h = init_conntrack(&tuple, l3proto, proto, skb, dataoff); | |
1021 | if (!h) | |
1022 | return NULL; | |
1023 | if (IS_ERR(h)) | |
1024 | return (void *)h; | |
1025 | } | |
1026 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1027 | ||
1028 | /* It exists; we have (non-exclusive) reference. */ | |
1029 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
1030 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
1031 | /* Please set reply bit if this packet OK */ | |
1032 | *set_reply = 1; | |
1033 | } else { | |
1034 | /* Once we've had two way comms, always ESTABLISHED. */ | |
1035 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
1036 | DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); | |
1037 | *ctinfo = IP_CT_ESTABLISHED; | |
1038 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
1039 | DEBUGP("nf_conntrack_in: related packet for %p\n", ct); | |
1040 | *ctinfo = IP_CT_RELATED; | |
1041 | } else { | |
1042 | DEBUGP("nf_conntrack_in: new packet for %p\n", ct); | |
1043 | *ctinfo = IP_CT_NEW; | |
1044 | } | |
1045 | *set_reply = 0; | |
1046 | } | |
1047 | skb->nfct = &ct->ct_general; | |
1048 | skb->nfctinfo = *ctinfo; | |
1049 | return ct; | |
1050 | } | |
1051 | ||
1052 | unsigned int | |
1053 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) | |
1054 | { | |
1055 | struct nf_conn *ct; | |
1056 | enum ip_conntrack_info ctinfo; | |
1057 | struct nf_conntrack_l3proto *l3proto; | |
1058 | struct nf_conntrack_protocol *proto; | |
1059 | unsigned int dataoff; | |
1060 | u_int8_t protonum; | |
1061 | int set_reply = 0; | |
1062 | int ret; | |
1063 | ||
1064 | /* Previously seen (loopback or untracked)? Ignore. */ | |
1065 | if ((*pskb)->nfct) { | |
1066 | NF_CT_STAT_INC(ignore); | |
1067 | return NF_ACCEPT; | |
1068 | } | |
1069 | ||
c1d10adb | 1070 | l3proto = __nf_ct_l3proto_find((u_int16_t)pf); |
9fb9cbb1 YK |
1071 | if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { |
1072 | DEBUGP("not prepared to track yet or error occured\n"); | |
1073 | return -ret; | |
1074 | } | |
1075 | ||
c1d10adb | 1076 | proto = __nf_ct_proto_find((u_int16_t)pf, protonum); |
9fb9cbb1 YK |
1077 | |
1078 | /* It may be an special packet, error, unclean... | |
1079 | * inverse of the return code tells to the netfilter | |
1080 | * core what to do with the packet. */ | |
1081 | if (proto->error != NULL && | |
1082 | (ret = proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { | |
1083 | NF_CT_STAT_INC(error); | |
1084 | NF_CT_STAT_INC(invalid); | |
1085 | return -ret; | |
1086 | } | |
1087 | ||
1088 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, proto, | |
1089 | &set_reply, &ctinfo); | |
1090 | if (!ct) { | |
1091 | /* Not valid part of a connection */ | |
1092 | NF_CT_STAT_INC(invalid); | |
1093 | return NF_ACCEPT; | |
1094 | } | |
1095 | ||
1096 | if (IS_ERR(ct)) { | |
1097 | /* Too stressed to deal. */ | |
1098 | NF_CT_STAT_INC(drop); | |
1099 | return NF_DROP; | |
1100 | } | |
1101 | ||
1102 | NF_CT_ASSERT((*pskb)->nfct); | |
1103 | ||
1104 | ret = proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); | |
1105 | if (ret < 0) { | |
1106 | /* Invalid: inverse of the return code tells | |
1107 | * the netfilter core what to do */ | |
1108 | DEBUGP("nf_conntrack_in: Can't track with proto module\n"); | |
1109 | nf_conntrack_put((*pskb)->nfct); | |
1110 | (*pskb)->nfct = NULL; | |
1111 | NF_CT_STAT_INC(invalid); | |
1112 | return -ret; | |
1113 | } | |
1114 | ||
1115 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
1116 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); | |
1117 | ||
1118 | return ret; | |
1119 | } | |
1120 | ||
1121 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
1122 | const struct nf_conntrack_tuple *orig) | |
1123 | { | |
1124 | return nf_ct_invert_tuple(inverse, orig, | |
c1d10adb PNA |
1125 | __nf_ct_l3proto_find(orig->src.l3num), |
1126 | __nf_ct_proto_find(orig->src.l3num, | |
1127 | orig->dst.protonum)); | |
9fb9cbb1 YK |
1128 | } |
1129 | ||
1130 | /* Would two expected things clash? */ | |
1131 | static inline int expect_clash(const struct nf_conntrack_expect *a, | |
1132 | const struct nf_conntrack_expect *b) | |
1133 | { | |
1134 | /* Part covered by intersection of masks must be unequal, | |
1135 | otherwise they clash */ | |
1136 | struct nf_conntrack_tuple intersect_mask; | |
1137 | int count; | |
1138 | ||
1139 | intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num; | |
1140 | intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all; | |
1141 | intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all; | |
1142 | intersect_mask.dst.protonum = a->mask.dst.protonum | |
1143 | & b->mask.dst.protonum; | |
1144 | ||
1145 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1146 | intersect_mask.src.u3.all[count] = | |
1147 | a->mask.src.u3.all[count] & b->mask.src.u3.all[count]; | |
1148 | } | |
1149 | ||
1150 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1151 | intersect_mask.dst.u3.all[count] = | |
1152 | a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count]; | |
1153 | } | |
1154 | ||
1155 | return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask); | |
1156 | } | |
1157 | ||
1158 | static inline int expect_matches(const struct nf_conntrack_expect *a, | |
1159 | const struct nf_conntrack_expect *b) | |
1160 | { | |
1161 | return a->master == b->master | |
1162 | && nf_ct_tuple_equal(&a->tuple, &b->tuple) | |
1163 | && nf_ct_tuple_equal(&a->mask, &b->mask); | |
1164 | } | |
1165 | ||
1166 | /* Generally a bad idea to call this: could have matched already. */ | |
1167 | void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp) | |
1168 | { | |
1169 | struct nf_conntrack_expect *i; | |
1170 | ||
1171 | write_lock_bh(&nf_conntrack_lock); | |
1172 | /* choose the the oldest expectation to evict */ | |
1173 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1174 | if (expect_matches(i, exp) && del_timer(&i->timeout)) { | |
1175 | nf_ct_unlink_expect(i); | |
1176 | write_unlock_bh(&nf_conntrack_lock); | |
1177 | nf_conntrack_expect_put(i); | |
1178 | return; | |
1179 | } | |
1180 | } | |
1181 | write_unlock_bh(&nf_conntrack_lock); | |
1182 | } | |
1183 | ||
1184 | /* We don't increase the master conntrack refcount for non-fulfilled | |
1185 | * conntracks. During the conntrack destruction, the expectations are | |
1186 | * always killed before the conntrack itself */ | |
1187 | struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me) | |
1188 | { | |
1189 | struct nf_conntrack_expect *new; | |
1190 | ||
1191 | new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC); | |
1192 | if (!new) { | |
1193 | DEBUGP("expect_related: OOM allocating expect\n"); | |
1194 | return NULL; | |
1195 | } | |
1196 | new->master = me; | |
1197 | atomic_set(&new->use, 1); | |
1198 | return new; | |
1199 | } | |
1200 | ||
1201 | void nf_conntrack_expect_put(struct nf_conntrack_expect *exp) | |
1202 | { | |
1203 | if (atomic_dec_and_test(&exp->use)) | |
1204 | kmem_cache_free(nf_conntrack_expect_cachep, exp); | |
1205 | } | |
1206 | ||
1207 | static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp) | |
1208 | { | |
1209 | atomic_inc(&exp->use); | |
1210 | exp->master->expecting++; | |
1211 | list_add(&exp->list, &nf_conntrack_expect_list); | |
1212 | ||
1213 | init_timer(&exp->timeout); | |
1214 | exp->timeout.data = (unsigned long)exp; | |
1215 | exp->timeout.function = expectation_timed_out; | |
1216 | exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ; | |
1217 | add_timer(&exp->timeout); | |
1218 | ||
c1d10adb | 1219 | exp->id = ++nf_conntrack_expect_next_id; |
9fb9cbb1 YK |
1220 | atomic_inc(&exp->use); |
1221 | NF_CT_STAT_INC(expect_create); | |
1222 | } | |
1223 | ||
1224 | /* Race with expectations being used means we could have none to find; OK. */ | |
1225 | static void evict_oldest_expect(struct nf_conn *master) | |
1226 | { | |
1227 | struct nf_conntrack_expect *i; | |
1228 | ||
1229 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1230 | if (i->master == master) { | |
1231 | if (del_timer(&i->timeout)) { | |
1232 | nf_ct_unlink_expect(i); | |
1233 | nf_conntrack_expect_put(i); | |
1234 | } | |
1235 | break; | |
1236 | } | |
1237 | } | |
1238 | } | |
1239 | ||
1240 | static inline int refresh_timer(struct nf_conntrack_expect *i) | |
1241 | { | |
1242 | if (!del_timer(&i->timeout)) | |
1243 | return 0; | |
1244 | ||
1245 | i->timeout.expires = jiffies + i->master->helper->timeout*HZ; | |
1246 | add_timer(&i->timeout); | |
1247 | return 1; | |
1248 | } | |
1249 | ||
1250 | int nf_conntrack_expect_related(struct nf_conntrack_expect *expect) | |
1251 | { | |
1252 | struct nf_conntrack_expect *i; | |
d695aa8a | 1253 | struct nf_conn *master = expect->master; |
9fb9cbb1 YK |
1254 | int ret; |
1255 | ||
1256 | DEBUGP("nf_conntrack_expect_related %p\n", related_to); | |
1257 | DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple); | |
1258 | DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask); | |
1259 | ||
1260 | write_lock_bh(&nf_conntrack_lock); | |
1261 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
1262 | if (expect_matches(i, expect)) { | |
1263 | /* Refresh timer: if it's dying, ignore.. */ | |
1264 | if (refresh_timer(i)) { | |
1265 | ret = 0; | |
1266 | goto out; | |
1267 | } | |
1268 | } else if (expect_clash(i, expect)) { | |
1269 | ret = -EBUSY; | |
1270 | goto out; | |
1271 | } | |
1272 | } | |
1273 | /* Will be over limit? */ | |
d695aa8a JJ |
1274 | if (master->helper->max_expected && |
1275 | master->expecting >= master->helper->max_expected) | |
1276 | evict_oldest_expect(master); | |
9fb9cbb1 YK |
1277 | |
1278 | nf_conntrack_expect_insert(expect); | |
1279 | nf_conntrack_expect_event(IPEXP_NEW, expect); | |
1280 | ret = 0; | |
1281 | out: | |
1282 | write_unlock_bh(&nf_conntrack_lock); | |
1283 | return ret; | |
1284 | } | |
1285 | ||
1286 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is | |
1287 | implicitly racy: see __nf_conntrack_confirm */ | |
1288 | void nf_conntrack_alter_reply(struct nf_conn *conntrack, | |
1289 | const struct nf_conntrack_tuple *newreply) | |
1290 | { | |
1291 | write_lock_bh(&nf_conntrack_lock); | |
1292 | /* Should be unconfirmed, so not in hash table yet */ | |
1293 | NF_CT_ASSERT(!nf_ct_is_confirmed(conntrack)); | |
1294 | ||
1295 | DEBUGP("Altering reply tuple of %p to ", conntrack); | |
1296 | NF_CT_DUMP_TUPLE(newreply); | |
1297 | ||
1298 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; | |
1299 | if (!conntrack->master && conntrack->expecting == 0) | |
c1d10adb | 1300 | conntrack->helper = __nf_ct_helper_find(newreply); |
9fb9cbb1 YK |
1301 | write_unlock_bh(&nf_conntrack_lock); |
1302 | } | |
1303 | ||
1304 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) | |
1305 | { | |
1306 | int ret; | |
1307 | BUG_ON(me->timeout == 0); | |
1308 | ||
1309 | ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help", | |
1310 | sizeof(struct nf_conn) | |
1311 | + sizeof(union nf_conntrack_help) | |
1312 | + __alignof__(union nf_conntrack_help), | |
1313 | init_conntrack_for_helper); | |
1314 | if (ret < 0) { | |
1315 | printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n"); | |
1316 | return ret; | |
1317 | } | |
1318 | write_lock_bh(&nf_conntrack_lock); | |
1319 | list_prepend(&helpers, me); | |
1320 | write_unlock_bh(&nf_conntrack_lock); | |
1321 | ||
1322 | return 0; | |
1323 | } | |
1324 | ||
c1d10adb PNA |
1325 | struct nf_conntrack_helper * |
1326 | __nf_conntrack_helper_find_byname(const char *name) | |
1327 | { | |
1328 | struct nf_conntrack_helper *h; | |
1329 | ||
1330 | list_for_each_entry(h, &helpers, list) { | |
1331 | if (!strcmp(h->name, name)) | |
1332 | return h; | |
1333 | } | |
1334 | ||
1335 | return NULL; | |
1336 | } | |
1337 | ||
9fb9cbb1 YK |
1338 | static inline int unhelp(struct nf_conntrack_tuple_hash *i, |
1339 | const struct nf_conntrack_helper *me) | |
1340 | { | |
1341 | if (nf_ct_tuplehash_to_ctrack(i)->helper == me) { | |
1342 | nf_conntrack_event(IPCT_HELPER, nf_ct_tuplehash_to_ctrack(i)); | |
1343 | nf_ct_tuplehash_to_ctrack(i)->helper = NULL; | |
1344 | } | |
1345 | return 0; | |
1346 | } | |
1347 | ||
1348 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) | |
1349 | { | |
1350 | unsigned int i; | |
1351 | struct nf_conntrack_expect *exp, *tmp; | |
1352 | ||
1353 | /* Need write lock here, to delete helper. */ | |
1354 | write_lock_bh(&nf_conntrack_lock); | |
1355 | LIST_DELETE(&helpers, me); | |
1356 | ||
1357 | /* Get rid of expectations */ | |
1358 | list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) { | |
1359 | if (exp->master->helper == me && del_timer(&exp->timeout)) { | |
1360 | nf_ct_unlink_expect(exp); | |
1361 | nf_conntrack_expect_put(exp); | |
1362 | } | |
1363 | } | |
1364 | ||
1365 | /* Get rid of expecteds, set helpers to NULL. */ | |
1366 | LIST_FIND_W(&unconfirmed, unhelp, struct nf_conntrack_tuple_hash*, me); | |
1367 | for (i = 0; i < nf_conntrack_htable_size; i++) | |
1368 | LIST_FIND_W(&nf_conntrack_hash[i], unhelp, | |
1369 | struct nf_conntrack_tuple_hash *, me); | |
1370 | write_unlock_bh(&nf_conntrack_lock); | |
1371 | ||
1372 | /* Someone could be still looking at the helper in a bh. */ | |
1373 | synchronize_net(); | |
1374 | } | |
1375 | ||
1376 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ | |
1377 | void __nf_ct_refresh_acct(struct nf_conn *ct, | |
1378 | enum ip_conntrack_info ctinfo, | |
1379 | const struct sk_buff *skb, | |
1380 | unsigned long extra_jiffies, | |
1381 | int do_acct) | |
1382 | { | |
1383 | int event = 0; | |
1384 | ||
1385 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); | |
1386 | NF_CT_ASSERT(skb); | |
1387 | ||
1388 | write_lock_bh(&nf_conntrack_lock); | |
1389 | ||
1390 | /* If not in hash table, timer will not be active yet */ | |
1391 | if (!nf_ct_is_confirmed(ct)) { | |
1392 | ct->timeout.expires = extra_jiffies; | |
1393 | event = IPCT_REFRESH; | |
1394 | } else { | |
1395 | /* Need del_timer for race avoidance (may already be dying). */ | |
1396 | if (del_timer(&ct->timeout)) { | |
1397 | ct->timeout.expires = jiffies + extra_jiffies; | |
1398 | add_timer(&ct->timeout); | |
1399 | event = IPCT_REFRESH; | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | #ifdef CONFIG_NF_CT_ACCT | |
1404 | if (do_acct) { | |
1405 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
1406 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
1407 | skb->len - (unsigned int)(skb->nh.raw - skb->data); | |
1408 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) | |
1409 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
1410 | event |= IPCT_COUNTER_FILLING; | |
1411 | } | |
1412 | #endif | |
1413 | ||
1414 | write_unlock_bh(&nf_conntrack_lock); | |
1415 | ||
1416 | /* must be unlocked when calling event cache */ | |
1417 | if (event) | |
1418 | nf_conntrack_event_cache(event, skb); | |
1419 | } | |
1420 | ||
c1d10adb PNA |
1421 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
1422 | defined(CONFIG_NF_CT_NETLINK_MODULE) | |
1423 | ||
1424 | #include <linux/netfilter/nfnetlink.h> | |
1425 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
1426 | ||
1427 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
1428 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
1429 | * or depend on ctnetlink */ | |
1430 | int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
1431 | const struct nf_conntrack_tuple *tuple) | |
1432 | { | |
1433 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), | |
1434 | &tuple->src.u.tcp.port); | |
1435 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), | |
1436 | &tuple->dst.u.tcp.port); | |
1437 | return 0; | |
1438 | ||
1439 | nfattr_failure: | |
1440 | return -1; | |
1441 | } | |
1442 | ||
1443 | static const size_t cta_min_proto[CTA_PROTO_MAX] = { | |
1444 | [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), | |
1445 | [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) | |
1446 | }; | |
1447 | ||
1448 | int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
1449 | struct nf_conntrack_tuple *t) | |
1450 | { | |
1451 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
1452 | return -EINVAL; | |
1453 | ||
1454 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
1455 | return -EINVAL; | |
1456 | ||
1457 | t->src.u.tcp.port = | |
1458 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); | |
1459 | t->dst.u.tcp.port = | |
1460 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); | |
1461 | ||
1462 | return 0; | |
1463 | } | |
1464 | #endif | |
1465 | ||
9fb9cbb1 YK |
1466 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
1467 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1468 | { | |
1469 | struct nf_conn *ct; | |
1470 | enum ip_conntrack_info ctinfo; | |
1471 | ||
1472 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1473 | ct = nf_ct_get(skb, &ctinfo); | |
1474 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1475 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
1476 | else | |
1477 | ctinfo = IP_CT_RELATED; | |
1478 | ||
1479 | /* Attach to new skbuff, and increment count */ | |
1480 | nskb->nfct = &ct->ct_general; | |
1481 | nskb->nfctinfo = ctinfo; | |
1482 | nf_conntrack_get(nskb->nfct); | |
1483 | } | |
1484 | ||
1485 | static inline int | |
1486 | do_iter(const struct nf_conntrack_tuple_hash *i, | |
1487 | int (*iter)(struct nf_conn *i, void *data), | |
1488 | void *data) | |
1489 | { | |
1490 | return iter(nf_ct_tuplehash_to_ctrack(i), data); | |
1491 | } | |
1492 | ||
1493 | /* Bring out ya dead! */ | |
1494 | static struct nf_conntrack_tuple_hash * | |
1495 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), | |
1496 | void *data, unsigned int *bucket) | |
1497 | { | |
1498 | struct nf_conntrack_tuple_hash *h = NULL; | |
1499 | ||
1500 | write_lock_bh(&nf_conntrack_lock); | |
1501 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { | |
1502 | h = LIST_FIND_W(&nf_conntrack_hash[*bucket], do_iter, | |
1503 | struct nf_conntrack_tuple_hash *, iter, data); | |
1504 | if (h) | |
1505 | break; | |
1506 | } | |
1507 | if (!h) | |
1508 | h = LIST_FIND_W(&unconfirmed, do_iter, | |
1509 | struct nf_conntrack_tuple_hash *, iter, data); | |
1510 | if (h) | |
1511 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
1512 | write_unlock_bh(&nf_conntrack_lock); | |
1513 | ||
1514 | return h; | |
1515 | } | |
1516 | ||
1517 | void | |
1518 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) | |
1519 | { | |
1520 | struct nf_conntrack_tuple_hash *h; | |
1521 | unsigned int bucket = 0; | |
1522 | ||
1523 | while ((h = get_next_corpse(iter, data, &bucket)) != NULL) { | |
1524 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); | |
1525 | /* Time to push up daises... */ | |
1526 | if (del_timer(&ct->timeout)) | |
1527 | death_by_timeout((unsigned long)ct); | |
1528 | /* ... else the timer will get him soon. */ | |
1529 | ||
1530 | nf_ct_put(ct); | |
1531 | } | |
1532 | } | |
1533 | ||
1534 | static int kill_all(struct nf_conn *i, void *data) | |
1535 | { | |
1536 | return 1; | |
1537 | } | |
1538 | ||
1539 | static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) | |
1540 | { | |
1541 | if (vmalloced) | |
1542 | vfree(hash); | |
1543 | else | |
1544 | free_pages((unsigned long)hash, | |
1545 | get_order(sizeof(struct list_head) * size)); | |
1546 | } | |
1547 | ||
c1d10adb PNA |
1548 | void nf_conntrack_flush() |
1549 | { | |
1550 | nf_ct_iterate_cleanup(kill_all, NULL); | |
1551 | } | |
1552 | ||
9fb9cbb1 YK |
1553 | /* Mishearing the voices in his head, our hero wonders how he's |
1554 | supposed to kill the mall. */ | |
1555 | void nf_conntrack_cleanup(void) | |
1556 | { | |
1557 | int i; | |
1558 | ||
1559 | /* This makes sure all current packets have passed through | |
1560 | netfilter framework. Roll on, two-stage module | |
1561 | delete... */ | |
1562 | synchronize_net(); | |
1563 | ||
1564 | nf_ct_event_cache_flush(); | |
1565 | i_see_dead_people: | |
c1d10adb | 1566 | nf_conntrack_flush(); |
9fb9cbb1 YK |
1567 | if (atomic_read(&nf_conntrack_count) != 0) { |
1568 | schedule(); | |
1569 | goto i_see_dead_people; | |
1570 | } | |
6636568c PM |
1571 | /* wait until all references to nf_conntrack_untracked are dropped */ |
1572 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) | |
1573 | schedule(); | |
9fb9cbb1 YK |
1574 | |
1575 | for (i = 0; i < NF_CT_F_NUM; i++) { | |
1576 | if (nf_ct_cache[i].use == 0) | |
1577 | continue; | |
1578 | ||
1579 | NF_CT_ASSERT(nf_ct_cache[i].use == 1); | |
1580 | nf_ct_cache[i].use = 1; | |
1581 | nf_conntrack_unregister_cache(i); | |
1582 | } | |
1583 | kmem_cache_destroy(nf_conntrack_expect_cachep); | |
1584 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1585 | nf_conntrack_htable_size); | |
5a6f294e KK |
1586 | |
1587 | /* free l3proto protocol tables */ | |
1588 | for (i = 0; i < PF_MAX; i++) | |
1589 | if (nf_ct_protos[i]) { | |
1590 | kfree(nf_ct_protos[i]); | |
1591 | nf_ct_protos[i] = NULL; | |
1592 | } | |
9fb9cbb1 YK |
1593 | } |
1594 | ||
1595 | static struct list_head *alloc_hashtable(int size, int *vmalloced) | |
1596 | { | |
1597 | struct list_head *hash; | |
1598 | unsigned int i; | |
1599 | ||
1600 | *vmalloced = 0; | |
1601 | hash = (void*)__get_free_pages(GFP_KERNEL, | |
1602 | get_order(sizeof(struct list_head) | |
1603 | * size)); | |
1604 | if (!hash) { | |
1605 | *vmalloced = 1; | |
1606 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
1607 | hash = vmalloc(sizeof(struct list_head) * size); | |
1608 | } | |
1609 | ||
1610 | if (hash) | |
1611 | for (i = 0; i < size; i++) | |
1612 | INIT_LIST_HEAD(&hash[i]); | |
1613 | ||
1614 | return hash; | |
1615 | } | |
1616 | ||
1617 | int set_hashsize(const char *val, struct kernel_param *kp) | |
1618 | { | |
1619 | int i, bucket, hashsize, vmalloced; | |
1620 | int old_vmalloced, old_size; | |
1621 | int rnd; | |
1622 | struct list_head *hash, *old_hash; | |
1623 | struct nf_conntrack_tuple_hash *h; | |
1624 | ||
1625 | /* On boot, we can set this without any fancy locking. */ | |
1626 | if (!nf_conntrack_htable_size) | |
1627 | return param_set_uint(val, kp); | |
1628 | ||
1629 | hashsize = simple_strtol(val, NULL, 0); | |
1630 | if (!hashsize) | |
1631 | return -EINVAL; | |
1632 | ||
1633 | hash = alloc_hashtable(hashsize, &vmalloced); | |
1634 | if (!hash) | |
1635 | return -ENOMEM; | |
1636 | ||
1637 | /* We have to rehahs for the new table anyway, so we also can | |
1638 | * use a newrandom seed */ | |
1639 | get_random_bytes(&rnd, 4); | |
1640 | ||
1641 | write_lock_bh(&nf_conntrack_lock); | |
1642 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
1643 | while (!list_empty(&nf_conntrack_hash[i])) { | |
1644 | h = list_entry(nf_conntrack_hash[i].next, | |
1645 | struct nf_conntrack_tuple_hash, list); | |
1646 | list_del(&h->list); | |
1647 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); | |
1648 | list_add_tail(&h->list, &hash[bucket]); | |
1649 | } | |
1650 | } | |
1651 | old_size = nf_conntrack_htable_size; | |
1652 | old_vmalloced = nf_conntrack_vmalloc; | |
1653 | old_hash = nf_conntrack_hash; | |
1654 | ||
1655 | nf_conntrack_htable_size = hashsize; | |
1656 | nf_conntrack_vmalloc = vmalloced; | |
1657 | nf_conntrack_hash = hash; | |
1658 | nf_conntrack_hash_rnd = rnd; | |
1659 | write_unlock_bh(&nf_conntrack_lock); | |
1660 | ||
1661 | free_conntrack_hash(old_hash, old_vmalloced, old_size); | |
1662 | return 0; | |
1663 | } | |
1664 | ||
1665 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1666 | &nf_conntrack_htable_size, 0600); | |
1667 | ||
1668 | int __init nf_conntrack_init(void) | |
1669 | { | |
1670 | unsigned int i; | |
1671 | int ret; | |
1672 | ||
1673 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1674 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ | |
1675 | if (!nf_conntrack_htable_size) { | |
1676 | nf_conntrack_htable_size | |
1677 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
1678 | / sizeof(struct list_head)); | |
1679 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1680 | nf_conntrack_htable_size = 8192; | |
1681 | if (nf_conntrack_htable_size < 16) | |
1682 | nf_conntrack_htable_size = 16; | |
1683 | } | |
1684 | nf_conntrack_max = 8 * nf_conntrack_htable_size; | |
1685 | ||
1686 | printk("nf_conntrack version %s (%u buckets, %d max)\n", | |
1687 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1688 | nf_conntrack_max); | |
1689 | ||
1690 | nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, | |
1691 | &nf_conntrack_vmalloc); | |
1692 | if (!nf_conntrack_hash) { | |
1693 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1694 | goto err_out; | |
1695 | } | |
1696 | ||
1697 | ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", | |
1698 | sizeof(struct nf_conn), NULL); | |
1699 | if (ret < 0) { | |
1700 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); | |
1701 | goto err_free_hash; | |
1702 | } | |
1703 | ||
1704 | nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", | |
1705 | sizeof(struct nf_conntrack_expect), | |
1706 | 0, 0, NULL, NULL); | |
1707 | if (!nf_conntrack_expect_cachep) { | |
1708 | printk(KERN_ERR "Unable to create nf_expect slab cache\n"); | |
1709 | goto err_free_conntrack_slab; | |
1710 | } | |
1711 | ||
1712 | /* Don't NEED lock here, but good form anyway. */ | |
1713 | write_lock_bh(&nf_conntrack_lock); | |
1714 | for (i = 0; i < PF_MAX; i++) | |
1715 | nf_ct_l3protos[i] = &nf_conntrack_generic_l3proto; | |
1716 | write_unlock_bh(&nf_conntrack_lock); | |
1717 | ||
1718 | /* Set up fake conntrack: | |
1719 | - to never be deleted, not in any hashes */ | |
1720 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); | |
1721 | /* - and look it like as a confirmed connection */ | |
1722 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); | |
1723 | ||
1724 | return ret; | |
1725 | ||
1726 | err_free_conntrack_slab: | |
1727 | nf_conntrack_unregister_cache(NF_CT_F_BASIC); | |
1728 | err_free_hash: | |
1729 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1730 | nf_conntrack_htable_size); | |
1731 | err_out: | |
1732 | return -ENOMEM; | |
1733 | } |