]>
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 | |
dc808fe2 | 6 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
9fb9cbb1 YK |
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. | |
dc808fe2 HW |
23 | * 26 Jan 2006: Harald Welte <laforge@netfilter.org> |
24 | * - restructure nf_conn (introduce nf_conn_help) | |
25 | * - redesign 'features' how they were originally intended | |
b9f78f9f PNA |
26 | * 26 Feb 2006: Pablo Neira Ayuso <pablo@eurodev.net> |
27 | * - add support for L3 protocol module load on demand. | |
9fb9cbb1 YK |
28 | * |
29 | * Derived from net/ipv4/netfilter/ip_conntrack_core.c | |
30 | */ | |
31 | ||
32 | #include <linux/config.h> | |
33 | #include <linux/types.h> | |
34 | #include <linux/netfilter.h> | |
35 | #include <linux/module.h> | |
36 | #include <linux/skbuff.h> | |
37 | #include <linux/proc_fs.h> | |
38 | #include <linux/vmalloc.h> | |
39 | #include <linux/stddef.h> | |
40 | #include <linux/slab.h> | |
41 | #include <linux/random.h> | |
42 | #include <linux/jhash.h> | |
43 | #include <linux/err.h> | |
44 | #include <linux/percpu.h> | |
45 | #include <linux/moduleparam.h> | |
46 | #include <linux/notifier.h> | |
47 | #include <linux/kernel.h> | |
48 | #include <linux/netdevice.h> | |
49 | #include <linux/socket.h> | |
50 | ||
51 | /* This rwlock protects the main hash table, protocol/helper/expected | |
52 | registrations, conntrack timers*/ | |
53 | #define ASSERT_READ_LOCK(x) | |
54 | #define ASSERT_WRITE_LOCK(x) | |
55 | ||
56 | #include <net/netfilter/nf_conntrack.h> | |
57 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
58 | #include <net/netfilter/nf_conntrack_protocol.h> | |
59 | #include <net/netfilter/nf_conntrack_helper.h> | |
60 | #include <net/netfilter/nf_conntrack_core.h> | |
61 | #include <linux/netfilter_ipv4/listhelp.h> | |
62 | ||
dc808fe2 | 63 | #define NF_CONNTRACK_VERSION "0.5.0" |
9fb9cbb1 YK |
64 | |
65 | #if 0 | |
66 | #define DEBUGP printk | |
67 | #else | |
68 | #define DEBUGP(format, args...) | |
69 | #endif | |
70 | ||
71 | DEFINE_RWLOCK(nf_conntrack_lock); | |
72 | ||
73 | /* nf_conntrack_standalone needs this */ | |
74 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); | |
75 | ||
76 | void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; | |
77 | LIST_HEAD(nf_conntrack_expect_list); | |
78 | struct nf_conntrack_protocol **nf_ct_protos[PF_MAX]; | |
79 | struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX]; | |
80 | static LIST_HEAD(helpers); | |
81 | unsigned int nf_conntrack_htable_size = 0; | |
82 | int nf_conntrack_max; | |
83 | struct list_head *nf_conntrack_hash; | |
84 | static kmem_cache_t *nf_conntrack_expect_cachep; | |
85 | struct nf_conn nf_conntrack_untracked; | |
86 | unsigned int nf_ct_log_invalid; | |
87 | static LIST_HEAD(unconfirmed); | |
88 | static int nf_conntrack_vmalloc; | |
89 | ||
4e3882f7 PNA |
90 | static unsigned int nf_conntrack_next_id; |
91 | static unsigned int nf_conntrack_expect_next_id; | |
9fb9cbb1 | 92 | #ifdef CONFIG_NF_CONNTRACK_EVENTS |
e041c683 AS |
93 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain); |
94 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_expect_chain); | |
9fb9cbb1 YK |
95 | |
96 | DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); | |
97 | ||
98 | /* deliver cached events and clear cache entry - must be called with locally | |
99 | * disabled softirqs */ | |
100 | static inline void | |
101 | __nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) | |
102 | { | |
103 | DEBUGP("ecache: delivering events for %p\n", ecache->ct); | |
104 | if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) | |
105 | && ecache->events) | |
e041c683 | 106 | atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events, |
9fb9cbb1 YK |
107 | ecache->ct); |
108 | ||
109 | ecache->events = 0; | |
110 | nf_ct_put(ecache->ct); | |
111 | ecache->ct = NULL; | |
112 | } | |
113 | ||
114 | /* Deliver all cached events for a particular conntrack. This is called | |
115 | * by code prior to async packet handling for freeing the skb */ | |
116 | void nf_ct_deliver_cached_events(const struct nf_conn *ct) | |
117 | { | |
118 | struct nf_conntrack_ecache *ecache; | |
119 | ||
120 | local_bh_disable(); | |
121 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
122 | if (ecache->ct == ct) | |
123 | __nf_ct_deliver_cached_events(ecache); | |
124 | local_bh_enable(); | |
125 | } | |
126 | ||
127 | /* Deliver cached events for old pending events, if current conntrack != old */ | |
128 | void __nf_ct_event_cache_init(struct nf_conn *ct) | |
129 | { | |
130 | struct nf_conntrack_ecache *ecache; | |
131 | ||
132 | /* take care of delivering potentially old events */ | |
133 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
134 | BUG_ON(ecache->ct == ct); | |
135 | if (ecache->ct) | |
136 | __nf_ct_deliver_cached_events(ecache); | |
137 | /* initialize for this conntrack/packet */ | |
138 | ecache->ct = ct; | |
139 | nf_conntrack_get(&ct->ct_general); | |
140 | } | |
141 | ||
142 | /* flush the event cache - touches other CPU's data and must not be called | |
143 | * while packets are still passing through the code */ | |
144 | static void nf_ct_event_cache_flush(void) | |
145 | { | |
146 | struct nf_conntrack_ecache *ecache; | |
147 | int cpu; | |
148 | ||
6f912042 | 149 | for_each_possible_cpu(cpu) { |
9fb9cbb1 YK |
150 | ecache = &per_cpu(nf_conntrack_ecache, cpu); |
151 | if (ecache->ct) | |
152 | nf_ct_put(ecache->ct); | |
153 | } | |
154 | } | |
155 | #else | |
156 | static inline void nf_ct_event_cache_flush(void) {} | |
157 | #endif /* CONFIG_NF_CONNTRACK_EVENTS */ | |
158 | ||
159 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); | |
160 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); | |
161 | ||
162 | /* | |
163 | * This scheme offers various size of "struct nf_conn" dependent on | |
164 | * features(helper, nat, ...) | |
165 | */ | |
166 | ||
167 | #define NF_CT_FEATURES_NAMELEN 256 | |
168 | static struct { | |
169 | /* name of slab cache. printed in /proc/slabinfo */ | |
170 | char *name; | |
171 | ||
172 | /* size of slab cache */ | |
173 | size_t size; | |
174 | ||
175 | /* slab cache pointer */ | |
176 | kmem_cache_t *cachep; | |
177 | ||
178 | /* allocated slab cache + modules which uses this slab cache */ | |
179 | int use; | |
180 | ||
9fb9cbb1 YK |
181 | } nf_ct_cache[NF_CT_F_NUM]; |
182 | ||
183 | /* protect members of nf_ct_cache except of "use" */ | |
184 | DEFINE_RWLOCK(nf_ct_cache_lock); | |
185 | ||
186 | /* This avoids calling kmem_cache_create() with same name simultaneously */ | |
57b47a53 | 187 | static DEFINE_MUTEX(nf_ct_cache_mutex); |
9fb9cbb1 YK |
188 | |
189 | extern struct nf_conntrack_protocol nf_conntrack_generic_protocol; | |
190 | struct nf_conntrack_protocol * | |
c1d10adb | 191 | __nf_ct_proto_find(u_int16_t l3proto, u_int8_t protocol) |
9fb9cbb1 | 192 | { |
ddc8d029 | 193 | if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL)) |
9fb9cbb1 YK |
194 | return &nf_conntrack_generic_protocol; |
195 | ||
196 | return nf_ct_protos[l3proto][protocol]; | |
197 | } | |
198 | ||
c1d10adb PNA |
199 | /* this is guaranteed to always return a valid protocol helper, since |
200 | * it falls back to generic_protocol */ | |
201 | struct nf_conntrack_protocol * | |
202 | nf_ct_proto_find_get(u_int16_t l3proto, u_int8_t protocol) | |
203 | { | |
204 | struct nf_conntrack_protocol *p; | |
205 | ||
206 | preempt_disable(); | |
207 | p = __nf_ct_proto_find(l3proto, protocol); | |
e1bbdebd YK |
208 | if (!try_module_get(p->me)) |
209 | p = &nf_conntrack_generic_protocol; | |
c1d10adb PNA |
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); | |
e1bbdebd YK |
227 | if (!try_module_get(p->me)) |
228 | p = &nf_conntrack_generic_l3proto; | |
c1d10adb PNA |
229 | preempt_enable(); |
230 | ||
231 | return p; | |
232 | } | |
233 | ||
234 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
235 | { | |
236 | module_put(p->me); | |
237 | } | |
238 | ||
b9f78f9f PNA |
239 | int |
240 | nf_ct_l3proto_try_module_get(unsigned short l3proto) | |
241 | { | |
242 | int ret; | |
243 | struct nf_conntrack_l3proto *p; | |
244 | ||
245 | retry: p = nf_ct_l3proto_find_get(l3proto); | |
246 | if (p == &nf_conntrack_generic_l3proto) { | |
247 | ret = request_module("nf_conntrack-%d", l3proto); | |
248 | if (!ret) | |
249 | goto retry; | |
250 | ||
251 | return -EPROTOTYPE; | |
252 | } | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | void nf_ct_l3proto_module_put(unsigned short l3proto) | |
258 | { | |
259 | struct nf_conntrack_l3proto *p; | |
260 | ||
261 | preempt_disable(); | |
262 | p = __nf_ct_l3proto_find(l3proto); | |
263 | preempt_enable(); | |
264 | ||
265 | module_put(p->me); | |
266 | } | |
267 | ||
9fb9cbb1 YK |
268 | static int nf_conntrack_hash_rnd_initted; |
269 | static unsigned int nf_conntrack_hash_rnd; | |
270 | ||
271 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
272 | unsigned int size, unsigned int rnd) | |
273 | { | |
274 | unsigned int a, b; | |
275 | a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), | |
276 | ((tuple->src.l3num) << 16) | tuple->dst.protonum); | |
277 | b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), | |
278 | (tuple->src.u.all << 16) | tuple->dst.u.all); | |
279 | ||
280 | return jhash_2words(a, b, rnd) % size; | |
281 | } | |
282 | ||
283 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) | |
284 | { | |
285 | return __hash_conntrack(tuple, nf_conntrack_htable_size, | |
286 | nf_conntrack_hash_rnd); | |
287 | } | |
288 | ||
9fb9cbb1 | 289 | int nf_conntrack_register_cache(u_int32_t features, const char *name, |
dc808fe2 | 290 | size_t size) |
9fb9cbb1 YK |
291 | { |
292 | int ret = 0; | |
293 | char *cache_name; | |
294 | kmem_cache_t *cachep; | |
295 | ||
296 | DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", | |
297 | features, name, size); | |
298 | ||
299 | if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { | |
300 | DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", | |
301 | features); | |
302 | return -EINVAL; | |
303 | } | |
304 | ||
57b47a53 | 305 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
306 | |
307 | write_lock_bh(&nf_ct_cache_lock); | |
308 | /* e.g: multiple helpers are loaded */ | |
309 | if (nf_ct_cache[features].use > 0) { | |
310 | DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); | |
311 | if ((!strncmp(nf_ct_cache[features].name, name, | |
312 | NF_CT_FEATURES_NAMELEN)) | |
dc808fe2 | 313 | && nf_ct_cache[features].size == size) { |
9fb9cbb1 YK |
314 | DEBUGP("nf_conntrack_register_cache: reusing.\n"); |
315 | nf_ct_cache[features].use++; | |
316 | ret = 0; | |
317 | } else | |
318 | ret = -EBUSY; | |
319 | ||
320 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 321 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
322 | return ret; |
323 | } | |
324 | write_unlock_bh(&nf_ct_cache_lock); | |
325 | ||
326 | /* | |
327 | * The memory space for name of slab cache must be alive until | |
328 | * cache is destroyed. | |
329 | */ | |
330 | cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); | |
331 | if (cache_name == NULL) { | |
332 | DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); | |
333 | ret = -ENOMEM; | |
334 | goto out_up_mutex; | |
335 | } | |
336 | ||
337 | if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) | |
338 | >= NF_CT_FEATURES_NAMELEN) { | |
339 | printk("nf_conntrack_register_cache: name too long\n"); | |
340 | ret = -EINVAL; | |
341 | goto out_free_name; | |
342 | } | |
343 | ||
344 | cachep = kmem_cache_create(cache_name, size, 0, 0, | |
345 | NULL, NULL); | |
346 | if (!cachep) { | |
347 | printk("nf_conntrack_register_cache: Can't create slab cache " | |
348 | "for the features = 0x%x\n", features); | |
349 | ret = -ENOMEM; | |
350 | goto out_free_name; | |
351 | } | |
352 | ||
353 | write_lock_bh(&nf_ct_cache_lock); | |
354 | nf_ct_cache[features].use = 1; | |
355 | nf_ct_cache[features].size = size; | |
9fb9cbb1 YK |
356 | nf_ct_cache[features].cachep = cachep; |
357 | nf_ct_cache[features].name = cache_name; | |
358 | write_unlock_bh(&nf_ct_cache_lock); | |
359 | ||
360 | goto out_up_mutex; | |
361 | ||
362 | out_free_name: | |
363 | kfree(cache_name); | |
364 | out_up_mutex: | |
57b47a53 | 365 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
366 | return ret; |
367 | } | |
368 | ||
369 | /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ | |
370 | void nf_conntrack_unregister_cache(u_int32_t features) | |
371 | { | |
372 | kmem_cache_t *cachep; | |
373 | char *name; | |
374 | ||
375 | /* | |
376 | * This assures that kmem_cache_create() isn't called before destroying | |
377 | * slab cache. | |
378 | */ | |
379 | DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); | |
57b47a53 | 380 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
381 | |
382 | write_lock_bh(&nf_ct_cache_lock); | |
383 | if (--nf_ct_cache[features].use > 0) { | |
384 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 385 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
386 | return; |
387 | } | |
388 | cachep = nf_ct_cache[features].cachep; | |
389 | name = nf_ct_cache[features].name; | |
390 | nf_ct_cache[features].cachep = NULL; | |
391 | nf_ct_cache[features].name = NULL; | |
9fb9cbb1 YK |
392 | nf_ct_cache[features].size = 0; |
393 | write_unlock_bh(&nf_ct_cache_lock); | |
394 | ||
395 | synchronize_net(); | |
396 | ||
397 | kmem_cache_destroy(cachep); | |
398 | kfree(name); | |
399 | ||
57b47a53 | 400 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
401 | } |
402 | ||
403 | int | |
404 | nf_ct_get_tuple(const struct sk_buff *skb, | |
405 | unsigned int nhoff, | |
406 | unsigned int dataoff, | |
407 | u_int16_t l3num, | |
408 | u_int8_t protonum, | |
409 | struct nf_conntrack_tuple *tuple, | |
410 | const struct nf_conntrack_l3proto *l3proto, | |
411 | const struct nf_conntrack_protocol *protocol) | |
412 | { | |
413 | NF_CT_TUPLE_U_BLANK(tuple); | |
414 | ||
415 | tuple->src.l3num = l3num; | |
416 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
417 | return 0; | |
418 | ||
419 | tuple->dst.protonum = protonum; | |
420 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
421 | ||
422 | return protocol->pkt_to_tuple(skb, dataoff, tuple); | |
423 | } | |
424 | ||
425 | int | |
426 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
427 | const struct nf_conntrack_tuple *orig, | |
428 | const struct nf_conntrack_l3proto *l3proto, | |
429 | const struct nf_conntrack_protocol *protocol) | |
430 | { | |
431 | NF_CT_TUPLE_U_BLANK(inverse); | |
432 | ||
433 | inverse->src.l3num = orig->src.l3num; | |
434 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
435 | return 0; | |
436 | ||
437 | inverse->dst.dir = !orig->dst.dir; | |
438 | ||
439 | inverse->dst.protonum = orig->dst.protonum; | |
440 | return protocol->invert_tuple(inverse, orig); | |
441 | } | |
442 | ||
443 | /* nf_conntrack_expect helper functions */ | |
c1d10adb | 444 | void nf_ct_unlink_expect(struct nf_conntrack_expect *exp) |
9fb9cbb1 | 445 | { |
dc808fe2 HW |
446 | struct nf_conn_help *master_help = nfct_help(exp->master); |
447 | ||
448 | NF_CT_ASSERT(master_help); | |
9fb9cbb1 | 449 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); |
4a59a810 | 450 | NF_CT_ASSERT(!timer_pending(&exp->timeout)); |
dc808fe2 | 451 | |
9fb9cbb1 YK |
452 | list_del(&exp->list); |
453 | NF_CT_STAT_INC(expect_delete); | |
dc808fe2 | 454 | master_help->expecting--; |
9fb9cbb1 YK |
455 | nf_conntrack_expect_put(exp); |
456 | } | |
457 | ||
458 | static void expectation_timed_out(unsigned long ul_expect) | |
459 | { | |
460 | struct nf_conntrack_expect *exp = (void *)ul_expect; | |
461 | ||
462 | write_lock_bh(&nf_conntrack_lock); | |
463 | nf_ct_unlink_expect(exp); | |
464 | write_unlock_bh(&nf_conntrack_lock); | |
465 | nf_conntrack_expect_put(exp); | |
466 | } | |
467 | ||
c1d10adb PNA |
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 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
474 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) { | |
475 | atomic_inc(&i->use); | |
476 | return i; | |
477 | } | |
478 | } | |
479 | return NULL; | |
480 | } | |
481 | ||
482 | /* Just find a expectation corresponding to a tuple. */ | |
483 | struct nf_conntrack_expect * | |
484 | nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) | |
485 | { | |
486 | struct nf_conntrack_expect *i; | |
487 | ||
488 | read_lock_bh(&nf_conntrack_lock); | |
489 | i = __nf_conntrack_expect_find(tuple); | |
490 | read_unlock_bh(&nf_conntrack_lock); | |
491 | ||
492 | return i; | |
493 | } | |
494 | ||
9fb9cbb1 YK |
495 | /* If an expectation for this connection is found, it gets delete from |
496 | * global list then returned. */ | |
497 | static struct nf_conntrack_expect * | |
498 | find_expectation(const struct nf_conntrack_tuple *tuple) | |
499 | { | |
500 | struct nf_conntrack_expect *i; | |
501 | ||
502 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
503 | /* If master is not in hash table yet (ie. packet hasn't left | |
504 | this machine yet), how can other end know about expected? | |
505 | Hence these are not the droids you are looking for (if | |
506 | master ct never got confirmed, we'd hold a reference to it | |
507 | and weird things would happen to future packets). */ | |
508 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) | |
509 | && nf_ct_is_confirmed(i->master)) { | |
510 | if (i->flags & NF_CT_EXPECT_PERMANENT) { | |
511 | atomic_inc(&i->use); | |
512 | return i; | |
513 | } else if (del_timer(&i->timeout)) { | |
514 | nf_ct_unlink_expect(i); | |
515 | return i; | |
516 | } | |
517 | } | |
518 | } | |
519 | return NULL; | |
520 | } | |
521 | ||
522 | /* delete all expectations for this conntrack */ | |
c1d10adb | 523 | void nf_ct_remove_expectations(struct nf_conn *ct) |
9fb9cbb1 YK |
524 | { |
525 | struct nf_conntrack_expect *i, *tmp; | |
dc808fe2 | 526 | struct nf_conn_help *help = nfct_help(ct); |
9fb9cbb1 YK |
527 | |
528 | /* Optimization: most connection never expect any others. */ | |
dc808fe2 | 529 | if (!help || help->expecting == 0) |
9fb9cbb1 YK |
530 | return; |
531 | ||
532 | list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) { | |
533 | if (i->master == ct && del_timer(&i->timeout)) { | |
534 | nf_ct_unlink_expect(i); | |
535 | nf_conntrack_expect_put(i); | |
536 | } | |
537 | } | |
538 | } | |
539 | ||
540 | static void | |
541 | clean_from_lists(struct nf_conn *ct) | |
542 | { | |
543 | unsigned int ho, hr; | |
544 | ||
545 | DEBUGP("clean_from_lists(%p)\n", ct); | |
546 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); | |
547 | ||
548 | ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
549 | hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
550 | LIST_DELETE(&nf_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]); | |
551 | LIST_DELETE(&nf_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]); | |
552 | ||
553 | /* Destroy all pending expectations */ | |
c1d10adb | 554 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
555 | } |
556 | ||
557 | static void | |
558 | destroy_conntrack(struct nf_conntrack *nfct) | |
559 | { | |
560 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
561 | struct nf_conntrack_l3proto *l3proto; | |
562 | struct nf_conntrack_protocol *proto; | |
563 | ||
564 | DEBUGP("destroy_conntrack(%p)\n", ct); | |
565 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); | |
566 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
567 | ||
568 | nf_conntrack_event(IPCT_DESTROY, ct); | |
569 | set_bit(IPS_DYING_BIT, &ct->status); | |
570 | ||
571 | /* To make sure we don't get any weird locking issues here: | |
572 | * destroy_conntrack() MUST NOT be called with a write lock | |
573 | * to nf_conntrack_lock!!! -HW */ | |
c1d10adb | 574 | l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); |
9fb9cbb1 YK |
575 | if (l3proto && l3proto->destroy) |
576 | l3proto->destroy(ct); | |
577 | ||
c1d10adb | 578 | 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 |
579 | if (proto && proto->destroy) |
580 | proto->destroy(ct); | |
581 | ||
582 | if (nf_conntrack_destroyed) | |
583 | nf_conntrack_destroyed(ct); | |
584 | ||
585 | write_lock_bh(&nf_conntrack_lock); | |
586 | /* Expectations will have been removed in clean_from_lists, | |
587 | * except TFTP can create an expectation on the first packet, | |
588 | * before connection is in the list, so we need to clean here, | |
589 | * too. */ | |
c1d10adb | 590 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
591 | |
592 | /* We overload first tuple to link into unconfirmed list. */ | |
593 | if (!nf_ct_is_confirmed(ct)) { | |
594 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); | |
595 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
596 | } | |
597 | ||
598 | NF_CT_STAT_INC(delete); | |
599 | write_unlock_bh(&nf_conntrack_lock); | |
600 | ||
601 | if (ct->master) | |
602 | nf_ct_put(ct->master); | |
603 | ||
604 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); | |
605 | nf_conntrack_free(ct); | |
606 | } | |
607 | ||
608 | static void death_by_timeout(unsigned long ul_conntrack) | |
609 | { | |
610 | struct nf_conn *ct = (void *)ul_conntrack; | |
611 | ||
612 | write_lock_bh(&nf_conntrack_lock); | |
613 | /* Inside lock so preempt is disabled on module removal path. | |
614 | * Otherwise we can get spurious warnings. */ | |
615 | NF_CT_STAT_INC(delete_list); | |
616 | clean_from_lists(ct); | |
617 | write_unlock_bh(&nf_conntrack_lock); | |
618 | nf_ct_put(ct); | |
619 | } | |
620 | ||
621 | static inline int | |
622 | conntrack_tuple_cmp(const struct nf_conntrack_tuple_hash *i, | |
623 | const struct nf_conntrack_tuple *tuple, | |
624 | const struct nf_conn *ignored_conntrack) | |
625 | { | |
626 | ASSERT_READ_LOCK(&nf_conntrack_lock); | |
627 | return nf_ct_tuplehash_to_ctrack(i) != ignored_conntrack | |
628 | && nf_ct_tuple_equal(tuple, &i->tuple); | |
629 | } | |
630 | ||
c1d10adb | 631 | struct nf_conntrack_tuple_hash * |
9fb9cbb1 YK |
632 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
633 | const struct nf_conn *ignored_conntrack) | |
634 | { | |
635 | struct nf_conntrack_tuple_hash *h; | |
636 | unsigned int hash = hash_conntrack(tuple); | |
637 | ||
638 | ASSERT_READ_LOCK(&nf_conntrack_lock); | |
639 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) { | |
640 | if (conntrack_tuple_cmp(h, tuple, ignored_conntrack)) { | |
641 | NF_CT_STAT_INC(found); | |
642 | return h; | |
643 | } | |
644 | NF_CT_STAT_INC(searched); | |
645 | } | |
646 | ||
647 | return NULL; | |
648 | } | |
649 | ||
650 | /* Find a connection corresponding to a tuple. */ | |
651 | struct nf_conntrack_tuple_hash * | |
652 | nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, | |
653 | const struct nf_conn *ignored_conntrack) | |
654 | { | |
655 | struct nf_conntrack_tuple_hash *h; | |
656 | ||
657 | read_lock_bh(&nf_conntrack_lock); | |
658 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
659 | if (h) | |
660 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
661 | read_unlock_bh(&nf_conntrack_lock); | |
662 | ||
663 | return h; | |
664 | } | |
665 | ||
c1d10adb PNA |
666 | static void __nf_conntrack_hash_insert(struct nf_conn *ct, |
667 | unsigned int hash, | |
668 | unsigned int repl_hash) | |
669 | { | |
670 | ct->id = ++nf_conntrack_next_id; | |
671 | list_prepend(&nf_conntrack_hash[hash], | |
672 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
673 | list_prepend(&nf_conntrack_hash[repl_hash], | |
674 | &ct->tuplehash[IP_CT_DIR_REPLY].list); | |
675 | } | |
676 | ||
677 | void nf_conntrack_hash_insert(struct nf_conn *ct) | |
678 | { | |
679 | unsigned int hash, repl_hash; | |
680 | ||
681 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
682 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
683 | ||
684 | write_lock_bh(&nf_conntrack_lock); | |
685 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
686 | write_unlock_bh(&nf_conntrack_lock); | |
687 | } | |
688 | ||
9fb9cbb1 YK |
689 | /* Confirm a connection given skb; places it in hash table */ |
690 | int | |
691 | __nf_conntrack_confirm(struct sk_buff **pskb) | |
692 | { | |
693 | unsigned int hash, repl_hash; | |
694 | struct nf_conn *ct; | |
695 | enum ip_conntrack_info ctinfo; | |
696 | ||
697 | ct = nf_ct_get(*pskb, &ctinfo); | |
698 | ||
699 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
700 | ICMP/TCP RST packets in other direction. Actual packet | |
701 | which created connection will be IP_CT_NEW or for an | |
702 | expected connection, IP_CT_RELATED. */ | |
703 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
704 | return NF_ACCEPT; | |
705 | ||
706 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
707 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
708 | ||
709 | /* We're not in hash table, and we refuse to set up related | |
710 | connections for unconfirmed conns. But packet copies and | |
711 | REJECT will give spurious warnings here. */ | |
712 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
713 | ||
714 | /* No external references means noone else could have | |
715 | confirmed us. */ | |
716 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
717 | DEBUGP("Confirming conntrack %p\n", ct); | |
718 | ||
719 | write_lock_bh(&nf_conntrack_lock); | |
720 | ||
721 | /* See if there's one in the list already, including reverse: | |
722 | NAT could have grabbed it without realizing, since we're | |
723 | not in the hash. If there is, we lost race. */ | |
724 | if (!LIST_FIND(&nf_conntrack_hash[hash], | |
725 | conntrack_tuple_cmp, | |
726 | struct nf_conntrack_tuple_hash *, | |
727 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL) | |
728 | && !LIST_FIND(&nf_conntrack_hash[repl_hash], | |
729 | conntrack_tuple_cmp, | |
730 | struct nf_conntrack_tuple_hash *, | |
731 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) { | |
dc808fe2 | 732 | struct nf_conn_help *help; |
9fb9cbb1 YK |
733 | /* Remove from unconfirmed list */ |
734 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
735 | ||
c1d10adb | 736 | __nf_conntrack_hash_insert(ct, hash, repl_hash); |
9fb9cbb1 YK |
737 | /* Timer relative to confirmation time, not original |
738 | setting time, otherwise we'd get timer wrap in | |
739 | weird delay cases. */ | |
740 | ct->timeout.expires += jiffies; | |
741 | add_timer(&ct->timeout); | |
742 | atomic_inc(&ct->ct_general.use); | |
743 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
744 | NF_CT_STAT_INC(insert); | |
745 | write_unlock_bh(&nf_conntrack_lock); | |
dc808fe2 HW |
746 | help = nfct_help(ct); |
747 | if (help && help->helper) | |
9fb9cbb1 YK |
748 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); |
749 | #ifdef CONFIG_NF_NAT_NEEDED | |
750 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || | |
751 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
752 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
753 | #endif | |
754 | nf_conntrack_event_cache(master_ct(ct) ? | |
755 | IPCT_RELATED : IPCT_NEW, *pskb); | |
756 | return NF_ACCEPT; | |
757 | } | |
758 | ||
759 | NF_CT_STAT_INC(insert_failed); | |
760 | write_unlock_bh(&nf_conntrack_lock); | |
761 | return NF_DROP; | |
762 | } | |
763 | ||
764 | /* Returns true if a connection correspondings to the tuple (required | |
765 | for NAT). */ | |
766 | int | |
767 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
768 | const struct nf_conn *ignored_conntrack) | |
769 | { | |
770 | struct nf_conntrack_tuple_hash *h; | |
771 | ||
772 | read_lock_bh(&nf_conntrack_lock); | |
773 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
774 | read_unlock_bh(&nf_conntrack_lock); | |
775 | ||
776 | return h != NULL; | |
777 | } | |
778 | ||
779 | /* There's a small race here where we may free a just-assured | |
780 | connection. Too bad: we're in trouble anyway. */ | |
781 | static inline int unreplied(const struct nf_conntrack_tuple_hash *i) | |
782 | { | |
783 | return !(test_bit(IPS_ASSURED_BIT, | |
784 | &nf_ct_tuplehash_to_ctrack(i)->status)); | |
785 | } | |
786 | ||
787 | static int early_drop(struct list_head *chain) | |
788 | { | |
789 | /* Traverse backwards: gives us oldest, which is roughly LRU */ | |
790 | struct nf_conntrack_tuple_hash *h; | |
791 | struct nf_conn *ct = NULL; | |
792 | int dropped = 0; | |
793 | ||
794 | read_lock_bh(&nf_conntrack_lock); | |
795 | h = LIST_FIND_B(chain, unreplied, struct nf_conntrack_tuple_hash *); | |
796 | if (h) { | |
797 | ct = nf_ct_tuplehash_to_ctrack(h); | |
798 | atomic_inc(&ct->ct_general.use); | |
799 | } | |
800 | read_unlock_bh(&nf_conntrack_lock); | |
801 | ||
802 | if (!ct) | |
803 | return dropped; | |
804 | ||
805 | if (del_timer(&ct->timeout)) { | |
806 | death_by_timeout((unsigned long)ct); | |
807 | dropped = 1; | |
808 | NF_CT_STAT_INC(early_drop); | |
809 | } | |
810 | nf_ct_put(ct); | |
811 | return dropped; | |
812 | } | |
813 | ||
814 | static inline int helper_cmp(const struct nf_conntrack_helper *i, | |
815 | const struct nf_conntrack_tuple *rtuple) | |
816 | { | |
817 | return nf_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask); | |
818 | } | |
819 | ||
820 | static struct nf_conntrack_helper * | |
c1d10adb | 821 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
9fb9cbb1 YK |
822 | { |
823 | return LIST_FIND(&helpers, helper_cmp, | |
824 | struct nf_conntrack_helper *, | |
825 | tuple); | |
826 | } | |
827 | ||
c1d10adb PNA |
828 | struct nf_conntrack_helper * |
829 | nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple) | |
830 | { | |
831 | struct nf_conntrack_helper *helper; | |
832 | ||
833 | /* need nf_conntrack_lock to assure that helper exists until | |
834 | * try_module_get() is called */ | |
835 | read_lock_bh(&nf_conntrack_lock); | |
836 | ||
837 | helper = __nf_ct_helper_find(tuple); | |
838 | if (helper) { | |
839 | /* need to increase module usage count to assure helper will | |
840 | * not go away while the caller is e.g. busy putting a | |
841 | * conntrack in the hash that uses the helper */ | |
842 | if (!try_module_get(helper->me)) | |
843 | helper = NULL; | |
844 | } | |
845 | ||
846 | read_unlock_bh(&nf_conntrack_lock); | |
847 | ||
848 | return helper; | |
849 | } | |
850 | ||
851 | void nf_ct_helper_put(struct nf_conntrack_helper *helper) | |
852 | { | |
853 | module_put(helper->me); | |
854 | } | |
855 | ||
9fb9cbb1 YK |
856 | static struct nf_conn * |
857 | __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
858 | const struct nf_conntrack_tuple *repl, | |
859 | const struct nf_conntrack_l3proto *l3proto) | |
860 | { | |
861 | struct nf_conn *conntrack = NULL; | |
862 | u_int32_t features = 0; | |
dc808fe2 | 863 | struct nf_conntrack_helper *helper; |
9fb9cbb1 | 864 | |
dc808fe2 | 865 | if (unlikely(!nf_conntrack_hash_rnd_initted)) { |
9fb9cbb1 YK |
866 | get_random_bytes(&nf_conntrack_hash_rnd, 4); |
867 | nf_conntrack_hash_rnd_initted = 1; | |
868 | } | |
869 | ||
870 | if (nf_conntrack_max | |
871 | && atomic_read(&nf_conntrack_count) >= nf_conntrack_max) { | |
872 | unsigned int hash = hash_conntrack(orig); | |
873 | /* Try dropping from this hash chain. */ | |
874 | if (!early_drop(&nf_conntrack_hash[hash])) { | |
875 | if (net_ratelimit()) | |
876 | printk(KERN_WARNING | |
877 | "nf_conntrack: table full, dropping" | |
878 | " packet.\n"); | |
879 | return ERR_PTR(-ENOMEM); | |
880 | } | |
881 | } | |
882 | ||
883 | /* find features needed by this conntrack. */ | |
884 | features = l3proto->get_features(orig); | |
dc808fe2 HW |
885 | |
886 | /* FIXME: protect helper list per RCU */ | |
9fb9cbb1 | 887 | read_lock_bh(&nf_conntrack_lock); |
dc808fe2 HW |
888 | helper = __nf_ct_helper_find(repl); |
889 | if (helper) | |
9fb9cbb1 YK |
890 | features |= NF_CT_F_HELP; |
891 | read_unlock_bh(&nf_conntrack_lock); | |
892 | ||
893 | DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); | |
894 | ||
895 | read_lock_bh(&nf_ct_cache_lock); | |
896 | ||
dc808fe2 | 897 | if (unlikely(!nf_ct_cache[features].use)) { |
9fb9cbb1 YK |
898 | DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", |
899 | features); | |
900 | goto out; | |
901 | } | |
902 | ||
903 | conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); | |
904 | if (conntrack == NULL) { | |
905 | DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); | |
906 | goto out; | |
907 | } | |
908 | ||
909 | memset(conntrack, 0, nf_ct_cache[features].size); | |
910 | conntrack->features = features; | |
dc808fe2 HW |
911 | if (helper) { |
912 | struct nf_conn_help *help = nfct_help(conntrack); | |
913 | NF_CT_ASSERT(help); | |
914 | help->helper = helper; | |
9fb9cbb1 YK |
915 | } |
916 | ||
917 | atomic_set(&conntrack->ct_general.use, 1); | |
918 | conntrack->ct_general.destroy = destroy_conntrack; | |
919 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; | |
920 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
921 | /* Don't set timer yet: wait for confirmation */ | |
922 | init_timer(&conntrack->timeout); | |
923 | conntrack->timeout.data = (unsigned long)conntrack; | |
924 | conntrack->timeout.function = death_by_timeout; | |
925 | ||
926 | atomic_inc(&nf_conntrack_count); | |
927 | out: | |
928 | read_unlock_bh(&nf_ct_cache_lock); | |
929 | return conntrack; | |
930 | } | |
931 | ||
932 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
933 | const struct nf_conntrack_tuple *repl) | |
934 | { | |
935 | struct nf_conntrack_l3proto *l3proto; | |
936 | ||
c1d10adb | 937 | l3proto = __nf_ct_l3proto_find(orig->src.l3num); |
9fb9cbb1 YK |
938 | return __nf_conntrack_alloc(orig, repl, l3proto); |
939 | } | |
940 | ||
941 | void nf_conntrack_free(struct nf_conn *conntrack) | |
942 | { | |
943 | u_int32_t features = conntrack->features; | |
944 | NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); | |
945 | DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, | |
946 | conntrack); | |
947 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); | |
948 | atomic_dec(&nf_conntrack_count); | |
949 | } | |
950 | ||
951 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
952 | failed due to stress. Otherwise it really is unclassifiable. */ | |
953 | static struct nf_conntrack_tuple_hash * | |
954 | init_conntrack(const struct nf_conntrack_tuple *tuple, | |
955 | struct nf_conntrack_l3proto *l3proto, | |
956 | struct nf_conntrack_protocol *protocol, | |
957 | struct sk_buff *skb, | |
958 | unsigned int dataoff) | |
959 | { | |
960 | struct nf_conn *conntrack; | |
961 | struct nf_conntrack_tuple repl_tuple; | |
962 | struct nf_conntrack_expect *exp; | |
963 | ||
964 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, protocol)) { | |
965 | DEBUGP("Can't invert tuple.\n"); | |
966 | return NULL; | |
967 | } | |
968 | ||
969 | conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto); | |
970 | if (conntrack == NULL || IS_ERR(conntrack)) { | |
971 | DEBUGP("Can't allocate conntrack.\n"); | |
972 | return (struct nf_conntrack_tuple_hash *)conntrack; | |
973 | } | |
974 | ||
975 | if (!protocol->new(conntrack, skb, dataoff)) { | |
976 | nf_conntrack_free(conntrack); | |
977 | DEBUGP("init conntrack: can't track with proto module\n"); | |
978 | return NULL; | |
979 | } | |
980 | ||
981 | write_lock_bh(&nf_conntrack_lock); | |
982 | exp = find_expectation(tuple); | |
983 | ||
984 | if (exp) { | |
985 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", | |
986 | conntrack, exp); | |
987 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
988 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
989 | conntrack->master = exp->master; | |
990 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
991 | conntrack->mark = exp->master->mark; | |
992 | #endif | |
993 | nf_conntrack_get(&conntrack->master->ct_general); | |
994 | NF_CT_STAT_INC(expect_new); | |
dc808fe2 | 995 | } else |
9fb9cbb1 | 996 | NF_CT_STAT_INC(new); |
9fb9cbb1 YK |
997 | |
998 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
999 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); | |
1000 | ||
1001 | write_unlock_bh(&nf_conntrack_lock); | |
1002 | ||
1003 | if (exp) { | |
1004 | if (exp->expectfn) | |
1005 | exp->expectfn(conntrack, exp); | |
1006 | nf_conntrack_expect_put(exp); | |
1007 | } | |
1008 | ||
1009 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
1010 | } | |
1011 | ||
1012 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
1013 | static inline struct nf_conn * | |
1014 | resolve_normal_ct(struct sk_buff *skb, | |
1015 | unsigned int dataoff, | |
1016 | u_int16_t l3num, | |
1017 | u_int8_t protonum, | |
1018 | struct nf_conntrack_l3proto *l3proto, | |
1019 | struct nf_conntrack_protocol *proto, | |
1020 | int *set_reply, | |
1021 | enum ip_conntrack_info *ctinfo) | |
1022 | { | |
1023 | struct nf_conntrack_tuple tuple; | |
1024 | struct nf_conntrack_tuple_hash *h; | |
1025 | struct nf_conn *ct; | |
1026 | ||
1027 | if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), | |
1028 | dataoff, l3num, protonum, &tuple, l3proto, | |
1029 | proto)) { | |
1030 | DEBUGP("resolve_normal_ct: Can't get tuple\n"); | |
1031 | return NULL; | |
1032 | } | |
1033 | ||
1034 | /* look for tuple match */ | |
1035 | h = nf_conntrack_find_get(&tuple, NULL); | |
1036 | if (!h) { | |
1037 | h = init_conntrack(&tuple, l3proto, proto, skb, dataoff); | |
1038 | if (!h) | |
1039 | return NULL; | |
1040 | if (IS_ERR(h)) | |
1041 | return (void *)h; | |
1042 | } | |
1043 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1044 | ||
1045 | /* It exists; we have (non-exclusive) reference. */ | |
1046 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
1047 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
1048 | /* Please set reply bit if this packet OK */ | |
1049 | *set_reply = 1; | |
1050 | } else { | |
1051 | /* Once we've had two way comms, always ESTABLISHED. */ | |
1052 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
1053 | DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); | |
1054 | *ctinfo = IP_CT_ESTABLISHED; | |
1055 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
1056 | DEBUGP("nf_conntrack_in: related packet for %p\n", ct); | |
1057 | *ctinfo = IP_CT_RELATED; | |
1058 | } else { | |
1059 | DEBUGP("nf_conntrack_in: new packet for %p\n", ct); | |
1060 | *ctinfo = IP_CT_NEW; | |
1061 | } | |
1062 | *set_reply = 0; | |
1063 | } | |
1064 | skb->nfct = &ct->ct_general; | |
1065 | skb->nfctinfo = *ctinfo; | |
1066 | return ct; | |
1067 | } | |
1068 | ||
1069 | unsigned int | |
1070 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) | |
1071 | { | |
1072 | struct nf_conn *ct; | |
1073 | enum ip_conntrack_info ctinfo; | |
1074 | struct nf_conntrack_l3proto *l3proto; | |
1075 | struct nf_conntrack_protocol *proto; | |
1076 | unsigned int dataoff; | |
1077 | u_int8_t protonum; | |
1078 | int set_reply = 0; | |
1079 | int ret; | |
1080 | ||
1081 | /* Previously seen (loopback or untracked)? Ignore. */ | |
1082 | if ((*pskb)->nfct) { | |
1083 | NF_CT_STAT_INC(ignore); | |
1084 | return NF_ACCEPT; | |
1085 | } | |
1086 | ||
c1d10adb | 1087 | l3proto = __nf_ct_l3proto_find((u_int16_t)pf); |
9fb9cbb1 YK |
1088 | if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { |
1089 | DEBUGP("not prepared to track yet or error occured\n"); | |
1090 | return -ret; | |
1091 | } | |
1092 | ||
c1d10adb | 1093 | proto = __nf_ct_proto_find((u_int16_t)pf, protonum); |
9fb9cbb1 YK |
1094 | |
1095 | /* It may be an special packet, error, unclean... | |
1096 | * inverse of the return code tells to the netfilter | |
1097 | * core what to do with the packet. */ | |
1098 | if (proto->error != NULL && | |
1099 | (ret = proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { | |
1100 | NF_CT_STAT_INC(error); | |
1101 | NF_CT_STAT_INC(invalid); | |
1102 | return -ret; | |
1103 | } | |
1104 | ||
1105 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, proto, | |
1106 | &set_reply, &ctinfo); | |
1107 | if (!ct) { | |
1108 | /* Not valid part of a connection */ | |
1109 | NF_CT_STAT_INC(invalid); | |
1110 | return NF_ACCEPT; | |
1111 | } | |
1112 | ||
1113 | if (IS_ERR(ct)) { | |
1114 | /* Too stressed to deal. */ | |
1115 | NF_CT_STAT_INC(drop); | |
1116 | return NF_DROP; | |
1117 | } | |
1118 | ||
1119 | NF_CT_ASSERT((*pskb)->nfct); | |
1120 | ||
1121 | ret = proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); | |
1122 | if (ret < 0) { | |
1123 | /* Invalid: inverse of the return code tells | |
1124 | * the netfilter core what to do */ | |
1125 | DEBUGP("nf_conntrack_in: Can't track with proto module\n"); | |
1126 | nf_conntrack_put((*pskb)->nfct); | |
1127 | (*pskb)->nfct = NULL; | |
1128 | NF_CT_STAT_INC(invalid); | |
1129 | return -ret; | |
1130 | } | |
1131 | ||
1132 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
1133 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); | |
1134 | ||
1135 | return ret; | |
1136 | } | |
1137 | ||
1138 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
1139 | const struct nf_conntrack_tuple *orig) | |
1140 | { | |
1141 | return nf_ct_invert_tuple(inverse, orig, | |
c1d10adb PNA |
1142 | __nf_ct_l3proto_find(orig->src.l3num), |
1143 | __nf_ct_proto_find(orig->src.l3num, | |
1144 | orig->dst.protonum)); | |
9fb9cbb1 YK |
1145 | } |
1146 | ||
1147 | /* Would two expected things clash? */ | |
1148 | static inline int expect_clash(const struct nf_conntrack_expect *a, | |
1149 | const struct nf_conntrack_expect *b) | |
1150 | { | |
1151 | /* Part covered by intersection of masks must be unequal, | |
1152 | otherwise they clash */ | |
1153 | struct nf_conntrack_tuple intersect_mask; | |
1154 | int count; | |
1155 | ||
1156 | intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num; | |
1157 | intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all; | |
1158 | intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all; | |
1159 | intersect_mask.dst.protonum = a->mask.dst.protonum | |
1160 | & b->mask.dst.protonum; | |
1161 | ||
1162 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1163 | intersect_mask.src.u3.all[count] = | |
1164 | a->mask.src.u3.all[count] & b->mask.src.u3.all[count]; | |
1165 | } | |
1166 | ||
1167 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1168 | intersect_mask.dst.u3.all[count] = | |
1169 | a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count]; | |
1170 | } | |
1171 | ||
1172 | return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask); | |
1173 | } | |
1174 | ||
1175 | static inline int expect_matches(const struct nf_conntrack_expect *a, | |
1176 | const struct nf_conntrack_expect *b) | |
1177 | { | |
1178 | return a->master == b->master | |
1179 | && nf_ct_tuple_equal(&a->tuple, &b->tuple) | |
1180 | && nf_ct_tuple_equal(&a->mask, &b->mask); | |
1181 | } | |
1182 | ||
1183 | /* Generally a bad idea to call this: could have matched already. */ | |
1184 | void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp) | |
1185 | { | |
1186 | struct nf_conntrack_expect *i; | |
1187 | ||
1188 | write_lock_bh(&nf_conntrack_lock); | |
1189 | /* choose the the oldest expectation to evict */ | |
1190 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1191 | if (expect_matches(i, exp) && del_timer(&i->timeout)) { | |
1192 | nf_ct_unlink_expect(i); | |
1193 | write_unlock_bh(&nf_conntrack_lock); | |
1194 | nf_conntrack_expect_put(i); | |
1195 | return; | |
1196 | } | |
1197 | } | |
1198 | write_unlock_bh(&nf_conntrack_lock); | |
1199 | } | |
1200 | ||
1201 | /* We don't increase the master conntrack refcount for non-fulfilled | |
1202 | * conntracks. During the conntrack destruction, the expectations are | |
1203 | * always killed before the conntrack itself */ | |
1204 | struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me) | |
1205 | { | |
1206 | struct nf_conntrack_expect *new; | |
1207 | ||
1208 | new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC); | |
1209 | if (!new) { | |
1210 | DEBUGP("expect_related: OOM allocating expect\n"); | |
1211 | return NULL; | |
1212 | } | |
1213 | new->master = me; | |
1214 | atomic_set(&new->use, 1); | |
1215 | return new; | |
1216 | } | |
1217 | ||
1218 | void nf_conntrack_expect_put(struct nf_conntrack_expect *exp) | |
1219 | { | |
1220 | if (atomic_dec_and_test(&exp->use)) | |
1221 | kmem_cache_free(nf_conntrack_expect_cachep, exp); | |
1222 | } | |
1223 | ||
1224 | static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp) | |
1225 | { | |
dc808fe2 HW |
1226 | struct nf_conn_help *master_help = nfct_help(exp->master); |
1227 | ||
9fb9cbb1 | 1228 | atomic_inc(&exp->use); |
dc808fe2 | 1229 | master_help->expecting++; |
9fb9cbb1 YK |
1230 | list_add(&exp->list, &nf_conntrack_expect_list); |
1231 | ||
1232 | init_timer(&exp->timeout); | |
1233 | exp->timeout.data = (unsigned long)exp; | |
1234 | exp->timeout.function = expectation_timed_out; | |
dc808fe2 | 1235 | exp->timeout.expires = jiffies + master_help->helper->timeout * HZ; |
9fb9cbb1 YK |
1236 | add_timer(&exp->timeout); |
1237 | ||
c1d10adb | 1238 | exp->id = ++nf_conntrack_expect_next_id; |
9fb9cbb1 YK |
1239 | atomic_inc(&exp->use); |
1240 | NF_CT_STAT_INC(expect_create); | |
1241 | } | |
1242 | ||
1243 | /* Race with expectations being used means we could have none to find; OK. */ | |
1244 | static void evict_oldest_expect(struct nf_conn *master) | |
1245 | { | |
1246 | struct nf_conntrack_expect *i; | |
1247 | ||
1248 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1249 | if (i->master == master) { | |
1250 | if (del_timer(&i->timeout)) { | |
1251 | nf_ct_unlink_expect(i); | |
1252 | nf_conntrack_expect_put(i); | |
1253 | } | |
1254 | break; | |
1255 | } | |
1256 | } | |
1257 | } | |
1258 | ||
1259 | static inline int refresh_timer(struct nf_conntrack_expect *i) | |
1260 | { | |
dc808fe2 HW |
1261 | struct nf_conn_help *master_help = nfct_help(i->master); |
1262 | ||
9fb9cbb1 YK |
1263 | if (!del_timer(&i->timeout)) |
1264 | return 0; | |
1265 | ||
dc808fe2 | 1266 | i->timeout.expires = jiffies + master_help->helper->timeout*HZ; |
9fb9cbb1 YK |
1267 | add_timer(&i->timeout); |
1268 | return 1; | |
1269 | } | |
1270 | ||
1271 | int nf_conntrack_expect_related(struct nf_conntrack_expect *expect) | |
1272 | { | |
1273 | struct nf_conntrack_expect *i; | |
d695aa8a | 1274 | struct nf_conn *master = expect->master; |
dc808fe2 | 1275 | struct nf_conn_help *master_help = nfct_help(master); |
9fb9cbb1 YK |
1276 | int ret; |
1277 | ||
dc808fe2 HW |
1278 | NF_CT_ASSERT(master_help); |
1279 | ||
9fb9cbb1 YK |
1280 | DEBUGP("nf_conntrack_expect_related %p\n", related_to); |
1281 | DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple); | |
1282 | DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask); | |
1283 | ||
1284 | write_lock_bh(&nf_conntrack_lock); | |
1285 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
1286 | if (expect_matches(i, expect)) { | |
1287 | /* Refresh timer: if it's dying, ignore.. */ | |
1288 | if (refresh_timer(i)) { | |
1289 | ret = 0; | |
1290 | goto out; | |
1291 | } | |
1292 | } else if (expect_clash(i, expect)) { | |
1293 | ret = -EBUSY; | |
1294 | goto out; | |
1295 | } | |
1296 | } | |
1297 | /* Will be over limit? */ | |
dc808fe2 HW |
1298 | if (master_help->helper->max_expected && |
1299 | master_help->expecting >= master_help->helper->max_expected) | |
d695aa8a | 1300 | evict_oldest_expect(master); |
9fb9cbb1 YK |
1301 | |
1302 | nf_conntrack_expect_insert(expect); | |
1303 | nf_conntrack_expect_event(IPEXP_NEW, expect); | |
1304 | ret = 0; | |
1305 | out: | |
1306 | write_unlock_bh(&nf_conntrack_lock); | |
1307 | return ret; | |
1308 | } | |
1309 | ||
9fb9cbb1 YK |
1310 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
1311 | { | |
1312 | int ret; | |
1313 | BUG_ON(me->timeout == 0); | |
1314 | ||
1315 | ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help", | |
1316 | sizeof(struct nf_conn) | |
dc808fe2 HW |
1317 | + sizeof(struct nf_conn_help) |
1318 | + __alignof__(struct nf_conn_help)); | |
9fb9cbb1 YK |
1319 | if (ret < 0) { |
1320 | printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n"); | |
1321 | return ret; | |
1322 | } | |
1323 | write_lock_bh(&nf_conntrack_lock); | |
1324 | list_prepend(&helpers, me); | |
1325 | write_unlock_bh(&nf_conntrack_lock); | |
1326 | ||
1327 | return 0; | |
1328 | } | |
1329 | ||
c1d10adb PNA |
1330 | struct nf_conntrack_helper * |
1331 | __nf_conntrack_helper_find_byname(const char *name) | |
1332 | { | |
1333 | struct nf_conntrack_helper *h; | |
1334 | ||
1335 | list_for_each_entry(h, &helpers, list) { | |
1336 | if (!strcmp(h->name, name)) | |
1337 | return h; | |
1338 | } | |
1339 | ||
1340 | return NULL; | |
1341 | } | |
1342 | ||
9fb9cbb1 YK |
1343 | static inline int unhelp(struct nf_conntrack_tuple_hash *i, |
1344 | const struct nf_conntrack_helper *me) | |
1345 | { | |
dc808fe2 HW |
1346 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i); |
1347 | struct nf_conn_help *help = nfct_help(ct); | |
1348 | ||
1349 | if (help && help->helper == me) { | |
1350 | nf_conntrack_event(IPCT_HELPER, ct); | |
1351 | help->helper = NULL; | |
9fb9cbb1 YK |
1352 | } |
1353 | return 0; | |
1354 | } | |
1355 | ||
1356 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) | |
1357 | { | |
1358 | unsigned int i; | |
1359 | struct nf_conntrack_expect *exp, *tmp; | |
1360 | ||
1361 | /* Need write lock here, to delete helper. */ | |
1362 | write_lock_bh(&nf_conntrack_lock); | |
1363 | LIST_DELETE(&helpers, me); | |
1364 | ||
1365 | /* Get rid of expectations */ | |
1366 | list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) { | |
dc808fe2 HW |
1367 | struct nf_conn_help *help = nfct_help(exp->master); |
1368 | if (help->helper == me && del_timer(&exp->timeout)) { | |
9fb9cbb1 YK |
1369 | nf_ct_unlink_expect(exp); |
1370 | nf_conntrack_expect_put(exp); | |
1371 | } | |
1372 | } | |
1373 | ||
1374 | /* Get rid of expecteds, set helpers to NULL. */ | |
1375 | LIST_FIND_W(&unconfirmed, unhelp, struct nf_conntrack_tuple_hash*, me); | |
1376 | for (i = 0; i < nf_conntrack_htable_size; i++) | |
1377 | LIST_FIND_W(&nf_conntrack_hash[i], unhelp, | |
1378 | struct nf_conntrack_tuple_hash *, me); | |
1379 | write_unlock_bh(&nf_conntrack_lock); | |
1380 | ||
1381 | /* Someone could be still looking at the helper in a bh. */ | |
1382 | synchronize_net(); | |
1383 | } | |
1384 | ||
1385 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ | |
1386 | void __nf_ct_refresh_acct(struct nf_conn *ct, | |
1387 | enum ip_conntrack_info ctinfo, | |
1388 | const struct sk_buff *skb, | |
1389 | unsigned long extra_jiffies, | |
1390 | int do_acct) | |
1391 | { | |
1392 | int event = 0; | |
1393 | ||
1394 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); | |
1395 | NF_CT_ASSERT(skb); | |
1396 | ||
1397 | write_lock_bh(&nf_conntrack_lock); | |
1398 | ||
1399 | /* If not in hash table, timer will not be active yet */ | |
1400 | if (!nf_ct_is_confirmed(ct)) { | |
1401 | ct->timeout.expires = extra_jiffies; | |
1402 | event = IPCT_REFRESH; | |
1403 | } else { | |
1404 | /* Need del_timer for race avoidance (may already be dying). */ | |
1405 | if (del_timer(&ct->timeout)) { | |
1406 | ct->timeout.expires = jiffies + extra_jiffies; | |
1407 | add_timer(&ct->timeout); | |
1408 | event = IPCT_REFRESH; | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | #ifdef CONFIG_NF_CT_ACCT | |
1413 | if (do_acct) { | |
1414 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
1415 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
1416 | skb->len - (unsigned int)(skb->nh.raw - skb->data); | |
1417 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) | |
1418 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
1419 | event |= IPCT_COUNTER_FILLING; | |
1420 | } | |
1421 | #endif | |
1422 | ||
1423 | write_unlock_bh(&nf_conntrack_lock); | |
1424 | ||
1425 | /* must be unlocked when calling event cache */ | |
1426 | if (event) | |
1427 | nf_conntrack_event_cache(event, skb); | |
1428 | } | |
1429 | ||
c1d10adb PNA |
1430 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
1431 | defined(CONFIG_NF_CT_NETLINK_MODULE) | |
1432 | ||
1433 | #include <linux/netfilter/nfnetlink.h> | |
1434 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
57b47a53 IM |
1435 | #include <linux/mutex.h> |
1436 | ||
c1d10adb PNA |
1437 | |
1438 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
1439 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
1440 | * or depend on ctnetlink */ | |
1441 | int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
1442 | const struct nf_conntrack_tuple *tuple) | |
1443 | { | |
1444 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), | |
1445 | &tuple->src.u.tcp.port); | |
1446 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), | |
1447 | &tuple->dst.u.tcp.port); | |
1448 | return 0; | |
1449 | ||
1450 | nfattr_failure: | |
1451 | return -1; | |
1452 | } | |
1453 | ||
1454 | static const size_t cta_min_proto[CTA_PROTO_MAX] = { | |
1455 | [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), | |
1456 | [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) | |
1457 | }; | |
1458 | ||
1459 | int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
1460 | struct nf_conntrack_tuple *t) | |
1461 | { | |
1462 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
1463 | return -EINVAL; | |
1464 | ||
1465 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
1466 | return -EINVAL; | |
1467 | ||
1468 | t->src.u.tcp.port = | |
1469 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); | |
1470 | t->dst.u.tcp.port = | |
1471 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); | |
1472 | ||
1473 | return 0; | |
1474 | } | |
1475 | #endif | |
1476 | ||
9fb9cbb1 YK |
1477 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
1478 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1479 | { | |
1480 | struct nf_conn *ct; | |
1481 | enum ip_conntrack_info ctinfo; | |
1482 | ||
1483 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1484 | ct = nf_ct_get(skb, &ctinfo); | |
1485 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1486 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
1487 | else | |
1488 | ctinfo = IP_CT_RELATED; | |
1489 | ||
1490 | /* Attach to new skbuff, and increment count */ | |
1491 | nskb->nfct = &ct->ct_general; | |
1492 | nskb->nfctinfo = ctinfo; | |
1493 | nf_conntrack_get(nskb->nfct); | |
1494 | } | |
1495 | ||
1496 | static inline int | |
1497 | do_iter(const struct nf_conntrack_tuple_hash *i, | |
1498 | int (*iter)(struct nf_conn *i, void *data), | |
1499 | void *data) | |
1500 | { | |
1501 | return iter(nf_ct_tuplehash_to_ctrack(i), data); | |
1502 | } | |
1503 | ||
1504 | /* Bring out ya dead! */ | |
1505 | static struct nf_conntrack_tuple_hash * | |
1506 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), | |
1507 | void *data, unsigned int *bucket) | |
1508 | { | |
1509 | struct nf_conntrack_tuple_hash *h = NULL; | |
1510 | ||
1511 | write_lock_bh(&nf_conntrack_lock); | |
1512 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { | |
1513 | h = LIST_FIND_W(&nf_conntrack_hash[*bucket], do_iter, | |
1514 | struct nf_conntrack_tuple_hash *, iter, data); | |
1515 | if (h) | |
1516 | break; | |
1517 | } | |
1518 | if (!h) | |
1519 | h = LIST_FIND_W(&unconfirmed, do_iter, | |
1520 | struct nf_conntrack_tuple_hash *, iter, data); | |
1521 | if (h) | |
1522 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
1523 | write_unlock_bh(&nf_conntrack_lock); | |
1524 | ||
1525 | return h; | |
1526 | } | |
1527 | ||
1528 | void | |
1529 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) | |
1530 | { | |
1531 | struct nf_conntrack_tuple_hash *h; | |
1532 | unsigned int bucket = 0; | |
1533 | ||
1534 | while ((h = get_next_corpse(iter, data, &bucket)) != NULL) { | |
1535 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); | |
1536 | /* Time to push up daises... */ | |
1537 | if (del_timer(&ct->timeout)) | |
1538 | death_by_timeout((unsigned long)ct); | |
1539 | /* ... else the timer will get him soon. */ | |
1540 | ||
1541 | nf_ct_put(ct); | |
1542 | } | |
1543 | } | |
1544 | ||
1545 | static int kill_all(struct nf_conn *i, void *data) | |
1546 | { | |
1547 | return 1; | |
1548 | } | |
1549 | ||
1550 | static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) | |
1551 | { | |
1552 | if (vmalloced) | |
1553 | vfree(hash); | |
1554 | else | |
1555 | free_pages((unsigned long)hash, | |
1556 | get_order(sizeof(struct list_head) * size)); | |
1557 | } | |
1558 | ||
c1d10adb PNA |
1559 | void nf_conntrack_flush() |
1560 | { | |
1561 | nf_ct_iterate_cleanup(kill_all, NULL); | |
1562 | } | |
1563 | ||
9fb9cbb1 YK |
1564 | /* Mishearing the voices in his head, our hero wonders how he's |
1565 | supposed to kill the mall. */ | |
1566 | void nf_conntrack_cleanup(void) | |
1567 | { | |
1568 | int i; | |
1569 | ||
7d3cdc6b YK |
1570 | ip_ct_attach = NULL; |
1571 | ||
9fb9cbb1 YK |
1572 | /* This makes sure all current packets have passed through |
1573 | netfilter framework. Roll on, two-stage module | |
1574 | delete... */ | |
1575 | synchronize_net(); | |
1576 | ||
1577 | nf_ct_event_cache_flush(); | |
1578 | i_see_dead_people: | |
c1d10adb | 1579 | nf_conntrack_flush(); |
9fb9cbb1 YK |
1580 | if (atomic_read(&nf_conntrack_count) != 0) { |
1581 | schedule(); | |
1582 | goto i_see_dead_people; | |
1583 | } | |
6636568c PM |
1584 | /* wait until all references to nf_conntrack_untracked are dropped */ |
1585 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) | |
1586 | schedule(); | |
9fb9cbb1 YK |
1587 | |
1588 | for (i = 0; i < NF_CT_F_NUM; i++) { | |
1589 | if (nf_ct_cache[i].use == 0) | |
1590 | continue; | |
1591 | ||
1592 | NF_CT_ASSERT(nf_ct_cache[i].use == 1); | |
1593 | nf_ct_cache[i].use = 1; | |
1594 | nf_conntrack_unregister_cache(i); | |
1595 | } | |
1596 | kmem_cache_destroy(nf_conntrack_expect_cachep); | |
1597 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1598 | nf_conntrack_htable_size); | |
5a6f294e KK |
1599 | |
1600 | /* free l3proto protocol tables */ | |
1601 | for (i = 0; i < PF_MAX; i++) | |
1602 | if (nf_ct_protos[i]) { | |
1603 | kfree(nf_ct_protos[i]); | |
1604 | nf_ct_protos[i] = NULL; | |
1605 | } | |
9fb9cbb1 YK |
1606 | } |
1607 | ||
1608 | static struct list_head *alloc_hashtable(int size, int *vmalloced) | |
1609 | { | |
1610 | struct list_head *hash; | |
1611 | unsigned int i; | |
1612 | ||
1613 | *vmalloced = 0; | |
1614 | hash = (void*)__get_free_pages(GFP_KERNEL, | |
1615 | get_order(sizeof(struct list_head) | |
1616 | * size)); | |
1617 | if (!hash) { | |
1618 | *vmalloced = 1; | |
1619 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
1620 | hash = vmalloc(sizeof(struct list_head) * size); | |
1621 | } | |
1622 | ||
1623 | if (hash) | |
1624 | for (i = 0; i < size; i++) | |
1625 | INIT_LIST_HEAD(&hash[i]); | |
1626 | ||
1627 | return hash; | |
1628 | } | |
1629 | ||
1630 | int set_hashsize(const char *val, struct kernel_param *kp) | |
1631 | { | |
1632 | int i, bucket, hashsize, vmalloced; | |
1633 | int old_vmalloced, old_size; | |
1634 | int rnd; | |
1635 | struct list_head *hash, *old_hash; | |
1636 | struct nf_conntrack_tuple_hash *h; | |
1637 | ||
1638 | /* On boot, we can set this without any fancy locking. */ | |
1639 | if (!nf_conntrack_htable_size) | |
1640 | return param_set_uint(val, kp); | |
1641 | ||
1642 | hashsize = simple_strtol(val, NULL, 0); | |
1643 | if (!hashsize) | |
1644 | return -EINVAL; | |
1645 | ||
1646 | hash = alloc_hashtable(hashsize, &vmalloced); | |
1647 | if (!hash) | |
1648 | return -ENOMEM; | |
1649 | ||
1650 | /* We have to rehahs for the new table anyway, so we also can | |
1651 | * use a newrandom seed */ | |
1652 | get_random_bytes(&rnd, 4); | |
1653 | ||
1654 | write_lock_bh(&nf_conntrack_lock); | |
1655 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
1656 | while (!list_empty(&nf_conntrack_hash[i])) { | |
1657 | h = list_entry(nf_conntrack_hash[i].next, | |
1658 | struct nf_conntrack_tuple_hash, list); | |
1659 | list_del(&h->list); | |
1660 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); | |
1661 | list_add_tail(&h->list, &hash[bucket]); | |
1662 | } | |
1663 | } | |
1664 | old_size = nf_conntrack_htable_size; | |
1665 | old_vmalloced = nf_conntrack_vmalloc; | |
1666 | old_hash = nf_conntrack_hash; | |
1667 | ||
1668 | nf_conntrack_htable_size = hashsize; | |
1669 | nf_conntrack_vmalloc = vmalloced; | |
1670 | nf_conntrack_hash = hash; | |
1671 | nf_conntrack_hash_rnd = rnd; | |
1672 | write_unlock_bh(&nf_conntrack_lock); | |
1673 | ||
1674 | free_conntrack_hash(old_hash, old_vmalloced, old_size); | |
1675 | return 0; | |
1676 | } | |
1677 | ||
1678 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1679 | &nf_conntrack_htable_size, 0600); | |
1680 | ||
1681 | int __init nf_conntrack_init(void) | |
1682 | { | |
1683 | unsigned int i; | |
1684 | int ret; | |
1685 | ||
1686 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1687 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ | |
1688 | if (!nf_conntrack_htable_size) { | |
1689 | nf_conntrack_htable_size | |
1690 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
1691 | / sizeof(struct list_head)); | |
1692 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1693 | nf_conntrack_htable_size = 8192; | |
1694 | if (nf_conntrack_htable_size < 16) | |
1695 | nf_conntrack_htable_size = 16; | |
1696 | } | |
1697 | nf_conntrack_max = 8 * nf_conntrack_htable_size; | |
1698 | ||
1699 | printk("nf_conntrack version %s (%u buckets, %d max)\n", | |
1700 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1701 | nf_conntrack_max); | |
1702 | ||
1703 | nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, | |
1704 | &nf_conntrack_vmalloc); | |
1705 | if (!nf_conntrack_hash) { | |
1706 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1707 | goto err_out; | |
1708 | } | |
1709 | ||
1710 | ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", | |
dc808fe2 | 1711 | sizeof(struct nf_conn)); |
9fb9cbb1 YK |
1712 | if (ret < 0) { |
1713 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); | |
1714 | goto err_free_hash; | |
1715 | } | |
1716 | ||
1717 | nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", | |
1718 | sizeof(struct nf_conntrack_expect), | |
1719 | 0, 0, NULL, NULL); | |
1720 | if (!nf_conntrack_expect_cachep) { | |
1721 | printk(KERN_ERR "Unable to create nf_expect slab cache\n"); | |
1722 | goto err_free_conntrack_slab; | |
1723 | } | |
1724 | ||
1725 | /* Don't NEED lock here, but good form anyway. */ | |
1726 | write_lock_bh(&nf_conntrack_lock); | |
1727 | for (i = 0; i < PF_MAX; i++) | |
1728 | nf_ct_l3protos[i] = &nf_conntrack_generic_l3proto; | |
1729 | write_unlock_bh(&nf_conntrack_lock); | |
1730 | ||
7d3cdc6b YK |
1731 | /* For use by REJECT target */ |
1732 | ip_ct_attach = __nf_conntrack_attach; | |
1733 | ||
9fb9cbb1 YK |
1734 | /* Set up fake conntrack: |
1735 | - to never be deleted, not in any hashes */ | |
1736 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); | |
1737 | /* - and look it like as a confirmed connection */ | |
1738 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); | |
1739 | ||
1740 | return ret; | |
1741 | ||
1742 | err_free_conntrack_slab: | |
1743 | nf_conntrack_unregister_cache(NF_CT_F_BASIC); | |
1744 | err_free_hash: | |
1745 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1746 | nf_conntrack_htable_size); | |
1747 | err_out: | |
1748 | return -ENOMEM; | |
1749 | } |