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Commit | Line | Data |
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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 | ||
9fb9cbb1 YK |
32 | #include <linux/types.h> |
33 | #include <linux/netfilter.h> | |
34 | #include <linux/module.h> | |
35 | #include <linux/skbuff.h> | |
36 | #include <linux/proc_fs.h> | |
37 | #include <linux/vmalloc.h> | |
38 | #include <linux/stddef.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/random.h> | |
41 | #include <linux/jhash.h> | |
42 | #include <linux/err.h> | |
43 | #include <linux/percpu.h> | |
44 | #include <linux/moduleparam.h> | |
45 | #include <linux/notifier.h> | |
46 | #include <linux/kernel.h> | |
47 | #include <linux/netdevice.h> | |
48 | #include <linux/socket.h> | |
49 | ||
50 | /* This rwlock protects the main hash table, protocol/helper/expected | |
51 | registrations, conntrack timers*/ | |
52 | #define ASSERT_READ_LOCK(x) | |
53 | #define ASSERT_WRITE_LOCK(x) | |
54 | ||
55 | #include <net/netfilter/nf_conntrack.h> | |
56 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
57 | #include <net/netfilter/nf_conntrack_protocol.h> | |
58 | #include <net/netfilter/nf_conntrack_helper.h> | |
59 | #include <net/netfilter/nf_conntrack_core.h> | |
9fb9cbb1 | 60 | |
dc808fe2 | 61 | #define NF_CONNTRACK_VERSION "0.5.0" |
9fb9cbb1 YK |
62 | |
63 | #if 0 | |
64 | #define DEBUGP printk | |
65 | #else | |
66 | #define DEBUGP(format, args...) | |
67 | #endif | |
68 | ||
69 | DEFINE_RWLOCK(nf_conntrack_lock); | |
70 | ||
71 | /* nf_conntrack_standalone needs this */ | |
72 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); | |
73 | ||
74 | void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; | |
75 | LIST_HEAD(nf_conntrack_expect_list); | |
1192e403 BH |
76 | struct nf_conntrack_protocol **nf_ct_protos[PF_MAX] __read_mostly; |
77 | struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX] __read_mostly; | |
9fb9cbb1 | 78 | static LIST_HEAD(helpers); |
94aec08e BH |
79 | unsigned int nf_conntrack_htable_size __read_mostly = 0; |
80 | int nf_conntrack_max __read_mostly; | |
1192e403 BH |
81 | struct list_head *nf_conntrack_hash __read_mostly; |
82 | static kmem_cache_t *nf_conntrack_expect_cachep __read_mostly; | |
9fb9cbb1 | 83 | struct nf_conn nf_conntrack_untracked; |
94aec08e | 84 | unsigned int nf_ct_log_invalid __read_mostly; |
9fb9cbb1 | 85 | static LIST_HEAD(unconfirmed); |
1192e403 | 86 | static int nf_conntrack_vmalloc __read_mostly; |
9fb9cbb1 | 87 | |
4e3882f7 PNA |
88 | static unsigned int nf_conntrack_next_id; |
89 | static unsigned int nf_conntrack_expect_next_id; | |
9fb9cbb1 | 90 | #ifdef CONFIG_NF_CONNTRACK_EVENTS |
e041c683 AS |
91 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain); |
92 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_expect_chain); | |
9fb9cbb1 YK |
93 | |
94 | DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); | |
95 | ||
96 | /* deliver cached events and clear cache entry - must be called with locally | |
97 | * disabled softirqs */ | |
98 | static inline void | |
99 | __nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) | |
100 | { | |
101 | DEBUGP("ecache: delivering events for %p\n", ecache->ct); | |
102 | if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) | |
103 | && ecache->events) | |
e041c683 | 104 | atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events, |
9fb9cbb1 YK |
105 | ecache->ct); |
106 | ||
107 | ecache->events = 0; | |
108 | nf_ct_put(ecache->ct); | |
109 | ecache->ct = NULL; | |
110 | } | |
111 | ||
112 | /* Deliver all cached events for a particular conntrack. This is called | |
113 | * by code prior to async packet handling for freeing the skb */ | |
114 | void nf_ct_deliver_cached_events(const struct nf_conn *ct) | |
115 | { | |
116 | struct nf_conntrack_ecache *ecache; | |
117 | ||
118 | local_bh_disable(); | |
119 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
120 | if (ecache->ct == ct) | |
121 | __nf_ct_deliver_cached_events(ecache); | |
122 | local_bh_enable(); | |
123 | } | |
124 | ||
125 | /* Deliver cached events for old pending events, if current conntrack != old */ | |
126 | void __nf_ct_event_cache_init(struct nf_conn *ct) | |
127 | { | |
128 | struct nf_conntrack_ecache *ecache; | |
129 | ||
130 | /* take care of delivering potentially old events */ | |
131 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
132 | BUG_ON(ecache->ct == ct); | |
133 | if (ecache->ct) | |
134 | __nf_ct_deliver_cached_events(ecache); | |
135 | /* initialize for this conntrack/packet */ | |
136 | ecache->ct = ct; | |
137 | nf_conntrack_get(&ct->ct_general); | |
138 | } | |
139 | ||
140 | /* flush the event cache - touches other CPU's data and must not be called | |
141 | * while packets are still passing through the code */ | |
142 | static void nf_ct_event_cache_flush(void) | |
143 | { | |
144 | struct nf_conntrack_ecache *ecache; | |
145 | int cpu; | |
146 | ||
6f912042 | 147 | for_each_possible_cpu(cpu) { |
9fb9cbb1 YK |
148 | ecache = &per_cpu(nf_conntrack_ecache, cpu); |
149 | if (ecache->ct) | |
150 | nf_ct_put(ecache->ct); | |
151 | } | |
152 | } | |
153 | #else | |
154 | static inline void nf_ct_event_cache_flush(void) {} | |
155 | #endif /* CONFIG_NF_CONNTRACK_EVENTS */ | |
156 | ||
157 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); | |
158 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); | |
159 | ||
160 | /* | |
161 | * This scheme offers various size of "struct nf_conn" dependent on | |
162 | * features(helper, nat, ...) | |
163 | */ | |
164 | ||
165 | #define NF_CT_FEATURES_NAMELEN 256 | |
166 | static struct { | |
167 | /* name of slab cache. printed in /proc/slabinfo */ | |
168 | char *name; | |
169 | ||
170 | /* size of slab cache */ | |
171 | size_t size; | |
172 | ||
173 | /* slab cache pointer */ | |
174 | kmem_cache_t *cachep; | |
175 | ||
176 | /* allocated slab cache + modules which uses this slab cache */ | |
177 | int use; | |
178 | ||
9fb9cbb1 YK |
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 */ | |
57b47a53 | 185 | static DEFINE_MUTEX(nf_ct_cache_mutex); |
9fb9cbb1 YK |
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); | |
e1bbdebd YK |
206 | if (!try_module_get(p->me)) |
207 | p = &nf_conntrack_generic_protocol; | |
c1d10adb PNA |
208 | preempt_enable(); |
209 | ||
210 | return p; | |
211 | } | |
212 | ||
213 | void nf_ct_proto_put(struct nf_conntrack_protocol *p) | |
214 | { | |
215 | module_put(p->me); | |
216 | } | |
217 | ||
218 | struct nf_conntrack_l3proto * | |
219 | nf_ct_l3proto_find_get(u_int16_t l3proto) | |
220 | { | |
221 | struct nf_conntrack_l3proto *p; | |
222 | ||
223 | preempt_disable(); | |
224 | p = __nf_ct_l3proto_find(l3proto); | |
e1bbdebd YK |
225 | if (!try_module_get(p->me)) |
226 | p = &nf_conntrack_generic_l3proto; | |
c1d10adb PNA |
227 | preempt_enable(); |
228 | ||
229 | return p; | |
230 | } | |
231 | ||
232 | void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) | |
233 | { | |
234 | module_put(p->me); | |
235 | } | |
236 | ||
b9f78f9f PNA |
237 | int |
238 | nf_ct_l3proto_try_module_get(unsigned short l3proto) | |
239 | { | |
240 | int ret; | |
241 | struct nf_conntrack_l3proto *p; | |
242 | ||
243 | retry: p = nf_ct_l3proto_find_get(l3proto); | |
244 | if (p == &nf_conntrack_generic_l3proto) { | |
245 | ret = request_module("nf_conntrack-%d", l3proto); | |
246 | if (!ret) | |
247 | goto retry; | |
248 | ||
249 | return -EPROTOTYPE; | |
250 | } | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | void nf_ct_l3proto_module_put(unsigned short l3proto) | |
256 | { | |
257 | struct nf_conntrack_l3proto *p; | |
258 | ||
259 | preempt_disable(); | |
260 | p = __nf_ct_l3proto_find(l3proto); | |
261 | preempt_enable(); | |
262 | ||
263 | module_put(p->me); | |
264 | } | |
265 | ||
9fb9cbb1 YK |
266 | static int nf_conntrack_hash_rnd_initted; |
267 | static unsigned int nf_conntrack_hash_rnd; | |
268 | ||
269 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
270 | unsigned int size, unsigned int rnd) | |
271 | { | |
272 | unsigned int a, b; | |
273 | a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), | |
274 | ((tuple->src.l3num) << 16) | tuple->dst.protonum); | |
275 | b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), | |
276 | (tuple->src.u.all << 16) | tuple->dst.u.all); | |
277 | ||
278 | return jhash_2words(a, b, rnd) % size; | |
279 | } | |
280 | ||
281 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) | |
282 | { | |
283 | return __hash_conntrack(tuple, nf_conntrack_htable_size, | |
284 | nf_conntrack_hash_rnd); | |
285 | } | |
286 | ||
9fb9cbb1 | 287 | int nf_conntrack_register_cache(u_int32_t features, const char *name, |
dc808fe2 | 288 | size_t size) |
9fb9cbb1 YK |
289 | { |
290 | int ret = 0; | |
291 | char *cache_name; | |
292 | kmem_cache_t *cachep; | |
293 | ||
294 | DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", | |
295 | features, name, size); | |
296 | ||
297 | if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { | |
298 | DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", | |
299 | features); | |
300 | return -EINVAL; | |
301 | } | |
302 | ||
57b47a53 | 303 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
304 | |
305 | write_lock_bh(&nf_ct_cache_lock); | |
306 | /* e.g: multiple helpers are loaded */ | |
307 | if (nf_ct_cache[features].use > 0) { | |
308 | DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); | |
309 | if ((!strncmp(nf_ct_cache[features].name, name, | |
310 | NF_CT_FEATURES_NAMELEN)) | |
dc808fe2 | 311 | && nf_ct_cache[features].size == size) { |
9fb9cbb1 YK |
312 | DEBUGP("nf_conntrack_register_cache: reusing.\n"); |
313 | nf_ct_cache[features].use++; | |
314 | ret = 0; | |
315 | } else | |
316 | ret = -EBUSY; | |
317 | ||
318 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 319 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
320 | return ret; |
321 | } | |
322 | write_unlock_bh(&nf_ct_cache_lock); | |
323 | ||
324 | /* | |
325 | * The memory space for name of slab cache must be alive until | |
326 | * cache is destroyed. | |
327 | */ | |
328 | cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); | |
329 | if (cache_name == NULL) { | |
330 | DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); | |
331 | ret = -ENOMEM; | |
332 | goto out_up_mutex; | |
333 | } | |
334 | ||
335 | if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) | |
336 | >= NF_CT_FEATURES_NAMELEN) { | |
337 | printk("nf_conntrack_register_cache: name too long\n"); | |
338 | ret = -EINVAL; | |
339 | goto out_free_name; | |
340 | } | |
341 | ||
342 | cachep = kmem_cache_create(cache_name, size, 0, 0, | |
343 | NULL, NULL); | |
344 | if (!cachep) { | |
345 | printk("nf_conntrack_register_cache: Can't create slab cache " | |
346 | "for the features = 0x%x\n", features); | |
347 | ret = -ENOMEM; | |
348 | goto out_free_name; | |
349 | } | |
350 | ||
351 | write_lock_bh(&nf_ct_cache_lock); | |
352 | nf_ct_cache[features].use = 1; | |
353 | nf_ct_cache[features].size = size; | |
9fb9cbb1 YK |
354 | nf_ct_cache[features].cachep = cachep; |
355 | nf_ct_cache[features].name = cache_name; | |
356 | write_unlock_bh(&nf_ct_cache_lock); | |
357 | ||
358 | goto out_up_mutex; | |
359 | ||
360 | out_free_name: | |
361 | kfree(cache_name); | |
362 | out_up_mutex: | |
57b47a53 | 363 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
364 | return ret; |
365 | } | |
366 | ||
367 | /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ | |
368 | void nf_conntrack_unregister_cache(u_int32_t features) | |
369 | { | |
370 | kmem_cache_t *cachep; | |
371 | char *name; | |
372 | ||
373 | /* | |
374 | * This assures that kmem_cache_create() isn't called before destroying | |
375 | * slab cache. | |
376 | */ | |
377 | DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); | |
57b47a53 | 378 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
379 | |
380 | write_lock_bh(&nf_ct_cache_lock); | |
381 | if (--nf_ct_cache[features].use > 0) { | |
382 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 383 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
384 | return; |
385 | } | |
386 | cachep = nf_ct_cache[features].cachep; | |
387 | name = nf_ct_cache[features].name; | |
388 | nf_ct_cache[features].cachep = NULL; | |
389 | nf_ct_cache[features].name = NULL; | |
9fb9cbb1 YK |
390 | nf_ct_cache[features].size = 0; |
391 | write_unlock_bh(&nf_ct_cache_lock); | |
392 | ||
393 | synchronize_net(); | |
394 | ||
395 | kmem_cache_destroy(cachep); | |
396 | kfree(name); | |
397 | ||
57b47a53 | 398 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
399 | } |
400 | ||
401 | int | |
402 | nf_ct_get_tuple(const struct sk_buff *skb, | |
403 | unsigned int nhoff, | |
404 | unsigned int dataoff, | |
405 | u_int16_t l3num, | |
406 | u_int8_t protonum, | |
407 | struct nf_conntrack_tuple *tuple, | |
408 | const struct nf_conntrack_l3proto *l3proto, | |
409 | const struct nf_conntrack_protocol *protocol) | |
410 | { | |
411 | NF_CT_TUPLE_U_BLANK(tuple); | |
412 | ||
413 | tuple->src.l3num = l3num; | |
414 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
415 | return 0; | |
416 | ||
417 | tuple->dst.protonum = protonum; | |
418 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
419 | ||
420 | return protocol->pkt_to_tuple(skb, dataoff, tuple); | |
421 | } | |
422 | ||
423 | int | |
424 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
425 | const struct nf_conntrack_tuple *orig, | |
426 | const struct nf_conntrack_l3proto *l3proto, | |
427 | const struct nf_conntrack_protocol *protocol) | |
428 | { | |
429 | NF_CT_TUPLE_U_BLANK(inverse); | |
430 | ||
431 | inverse->src.l3num = orig->src.l3num; | |
432 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
433 | return 0; | |
434 | ||
435 | inverse->dst.dir = !orig->dst.dir; | |
436 | ||
437 | inverse->dst.protonum = orig->dst.protonum; | |
438 | return protocol->invert_tuple(inverse, orig); | |
439 | } | |
440 | ||
441 | /* nf_conntrack_expect helper functions */ | |
c1d10adb | 442 | void nf_ct_unlink_expect(struct nf_conntrack_expect *exp) |
9fb9cbb1 | 443 | { |
dc808fe2 HW |
444 | struct nf_conn_help *master_help = nfct_help(exp->master); |
445 | ||
446 | NF_CT_ASSERT(master_help); | |
9fb9cbb1 | 447 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); |
4a59a810 | 448 | NF_CT_ASSERT(!timer_pending(&exp->timeout)); |
dc808fe2 | 449 | |
9fb9cbb1 YK |
450 | list_del(&exp->list); |
451 | NF_CT_STAT_INC(expect_delete); | |
dc808fe2 | 452 | master_help->expecting--; |
9fb9cbb1 YK |
453 | nf_conntrack_expect_put(exp); |
454 | } | |
455 | ||
456 | static void expectation_timed_out(unsigned long ul_expect) | |
457 | { | |
458 | struct nf_conntrack_expect *exp = (void *)ul_expect; | |
459 | ||
460 | write_lock_bh(&nf_conntrack_lock); | |
461 | nf_ct_unlink_expect(exp); | |
462 | write_unlock_bh(&nf_conntrack_lock); | |
463 | nf_conntrack_expect_put(exp); | |
464 | } | |
465 | ||
c1d10adb PNA |
466 | struct nf_conntrack_expect * |
467 | __nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) | |
468 | { | |
469 | struct nf_conntrack_expect *i; | |
470 | ||
471 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
2e47c264 | 472 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) |
c1d10adb | 473 | return i; |
c1d10adb PNA |
474 | } |
475 | return NULL; | |
476 | } | |
477 | ||
478 | /* Just find a expectation corresponding to a tuple. */ | |
479 | struct nf_conntrack_expect * | |
480 | nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) | |
481 | { | |
482 | struct nf_conntrack_expect *i; | |
483 | ||
484 | read_lock_bh(&nf_conntrack_lock); | |
485 | i = __nf_conntrack_expect_find(tuple); | |
2e47c264 YK |
486 | if (i) |
487 | atomic_inc(&i->use); | |
c1d10adb PNA |
488 | read_unlock_bh(&nf_conntrack_lock); |
489 | ||
490 | return i; | |
491 | } | |
492 | ||
9fb9cbb1 YK |
493 | /* If an expectation for this connection is found, it gets delete from |
494 | * global list then returned. */ | |
495 | static struct nf_conntrack_expect * | |
496 | find_expectation(const struct nf_conntrack_tuple *tuple) | |
497 | { | |
498 | struct nf_conntrack_expect *i; | |
499 | ||
500 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
501 | /* If master is not in hash table yet (ie. packet hasn't left | |
502 | this machine yet), how can other end know about expected? | |
503 | Hence these are not the droids you are looking for (if | |
504 | master ct never got confirmed, we'd hold a reference to it | |
505 | and weird things would happen to future packets). */ | |
506 | if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) | |
507 | && nf_ct_is_confirmed(i->master)) { | |
508 | if (i->flags & NF_CT_EXPECT_PERMANENT) { | |
509 | atomic_inc(&i->use); | |
510 | return i; | |
511 | } else if (del_timer(&i->timeout)) { | |
512 | nf_ct_unlink_expect(i); | |
513 | return i; | |
514 | } | |
515 | } | |
516 | } | |
517 | return NULL; | |
518 | } | |
519 | ||
520 | /* delete all expectations for this conntrack */ | |
c1d10adb | 521 | void nf_ct_remove_expectations(struct nf_conn *ct) |
9fb9cbb1 YK |
522 | { |
523 | struct nf_conntrack_expect *i, *tmp; | |
dc808fe2 | 524 | struct nf_conn_help *help = nfct_help(ct); |
9fb9cbb1 YK |
525 | |
526 | /* Optimization: most connection never expect any others. */ | |
dc808fe2 | 527 | if (!help || help->expecting == 0) |
9fb9cbb1 YK |
528 | return; |
529 | ||
530 | list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) { | |
531 | if (i->master == ct && del_timer(&i->timeout)) { | |
532 | nf_ct_unlink_expect(i); | |
533 | nf_conntrack_expect_put(i); | |
534 | } | |
535 | } | |
536 | } | |
537 | ||
538 | static void | |
539 | clean_from_lists(struct nf_conn *ct) | |
540 | { | |
9fb9cbb1 YK |
541 | DEBUGP("clean_from_lists(%p)\n", ct); |
542 | ASSERT_WRITE_LOCK(&nf_conntrack_lock); | |
df0933dc PM |
543 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); |
544 | list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); | |
9fb9cbb1 YK |
545 | |
546 | /* Destroy all pending expectations */ | |
c1d10adb | 547 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
548 | } |
549 | ||
550 | static void | |
551 | destroy_conntrack(struct nf_conntrack *nfct) | |
552 | { | |
553 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
554 | struct nf_conntrack_l3proto *l3proto; | |
555 | struct nf_conntrack_protocol *proto; | |
556 | ||
557 | DEBUGP("destroy_conntrack(%p)\n", ct); | |
558 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); | |
559 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
560 | ||
561 | nf_conntrack_event(IPCT_DESTROY, ct); | |
562 | set_bit(IPS_DYING_BIT, &ct->status); | |
563 | ||
564 | /* To make sure we don't get any weird locking issues here: | |
565 | * destroy_conntrack() MUST NOT be called with a write lock | |
566 | * to nf_conntrack_lock!!! -HW */ | |
c1d10adb | 567 | l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); |
9fb9cbb1 YK |
568 | if (l3proto && l3proto->destroy) |
569 | l3proto->destroy(ct); | |
570 | ||
c1d10adb | 571 | 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 |
572 | if (proto && proto->destroy) |
573 | proto->destroy(ct); | |
574 | ||
575 | if (nf_conntrack_destroyed) | |
576 | nf_conntrack_destroyed(ct); | |
577 | ||
578 | write_lock_bh(&nf_conntrack_lock); | |
579 | /* Expectations will have been removed in clean_from_lists, | |
580 | * except TFTP can create an expectation on the first packet, | |
581 | * before connection is in the list, so we need to clean here, | |
582 | * too. */ | |
c1d10adb | 583 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
584 | |
585 | /* We overload first tuple to link into unconfirmed list. */ | |
586 | if (!nf_ct_is_confirmed(ct)) { | |
587 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); | |
588 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
589 | } | |
590 | ||
591 | NF_CT_STAT_INC(delete); | |
592 | write_unlock_bh(&nf_conntrack_lock); | |
593 | ||
594 | if (ct->master) | |
595 | nf_ct_put(ct->master); | |
596 | ||
597 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); | |
598 | nf_conntrack_free(ct); | |
599 | } | |
600 | ||
601 | static void death_by_timeout(unsigned long ul_conntrack) | |
602 | { | |
603 | struct nf_conn *ct = (void *)ul_conntrack; | |
604 | ||
605 | write_lock_bh(&nf_conntrack_lock); | |
606 | /* Inside lock so preempt is disabled on module removal path. | |
607 | * Otherwise we can get spurious warnings. */ | |
608 | NF_CT_STAT_INC(delete_list); | |
609 | clean_from_lists(ct); | |
610 | write_unlock_bh(&nf_conntrack_lock); | |
611 | nf_ct_put(ct); | |
612 | } | |
613 | ||
c1d10adb | 614 | struct nf_conntrack_tuple_hash * |
9fb9cbb1 YK |
615 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
616 | const struct nf_conn *ignored_conntrack) | |
617 | { | |
618 | struct nf_conntrack_tuple_hash *h; | |
619 | unsigned int hash = hash_conntrack(tuple); | |
620 | ||
621 | ASSERT_READ_LOCK(&nf_conntrack_lock); | |
622 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) { | |
df0933dc PM |
623 | if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && |
624 | nf_ct_tuple_equal(tuple, &h->tuple)) { | |
9fb9cbb1 YK |
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; | |
df0933dc PM |
655 | list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, |
656 | &nf_conntrack_hash[hash]); | |
657 | list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, | |
658 | &nf_conntrack_hash[repl_hash]); | |
c1d10adb PNA |
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; | |
df0933dc | 678 | struct nf_conntrack_tuple_hash *h; |
9fb9cbb1 | 679 | struct nf_conn *ct; |
df0933dc | 680 | struct nf_conn_help *help; |
9fb9cbb1 YK |
681 | enum ip_conntrack_info ctinfo; |
682 | ||
683 | ct = nf_ct_get(*pskb, &ctinfo); | |
684 | ||
685 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
686 | ICMP/TCP RST packets in other direction. Actual packet | |
687 | which created connection will be IP_CT_NEW or for an | |
688 | expected connection, IP_CT_RELATED. */ | |
689 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
690 | return NF_ACCEPT; | |
691 | ||
692 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
693 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
694 | ||
695 | /* We're not in hash table, and we refuse to set up related | |
696 | connections for unconfirmed conns. But packet copies and | |
697 | REJECT will give spurious warnings here. */ | |
698 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
699 | ||
700 | /* No external references means noone else could have | |
701 | confirmed us. */ | |
702 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
703 | DEBUGP("Confirming conntrack %p\n", ct); | |
704 | ||
705 | write_lock_bh(&nf_conntrack_lock); | |
706 | ||
707 | /* See if there's one in the list already, including reverse: | |
708 | NAT could have grabbed it without realizing, since we're | |
709 | not in the hash. If there is, we lost race. */ | |
df0933dc PM |
710 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) |
711 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, | |
712 | &h->tuple)) | |
713 | goto out; | |
714 | list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list) | |
715 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, | |
716 | &h->tuple)) | |
717 | goto out; | |
9fb9cbb1 | 718 | |
df0933dc PM |
719 | /* Remove from unconfirmed list */ |
720 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
721 | ||
722 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
723 | /* Timer relative to confirmation time, not original | |
724 | setting time, otherwise we'd get timer wrap in | |
725 | weird delay cases. */ | |
726 | ct->timeout.expires += jiffies; | |
727 | add_timer(&ct->timeout); | |
728 | atomic_inc(&ct->ct_general.use); | |
729 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
730 | NF_CT_STAT_INC(insert); | |
731 | write_unlock_bh(&nf_conntrack_lock); | |
732 | help = nfct_help(ct); | |
733 | if (help && help->helper) | |
734 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); | |
9fb9cbb1 | 735 | #ifdef CONFIG_NF_NAT_NEEDED |
df0933dc PM |
736 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || |
737 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
738 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
9fb9cbb1 | 739 | #endif |
df0933dc PM |
740 | nf_conntrack_event_cache(master_ct(ct) ? |
741 | IPCT_RELATED : IPCT_NEW, *pskb); | |
742 | return NF_ACCEPT; | |
9fb9cbb1 | 743 | |
df0933dc | 744 | out: |
9fb9cbb1 YK |
745 | NF_CT_STAT_INC(insert_failed); |
746 | write_unlock_bh(&nf_conntrack_lock); | |
747 | return NF_DROP; | |
748 | } | |
749 | ||
750 | /* Returns true if a connection correspondings to the tuple (required | |
751 | for NAT). */ | |
752 | int | |
753 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
754 | const struct nf_conn *ignored_conntrack) | |
755 | { | |
756 | struct nf_conntrack_tuple_hash *h; | |
757 | ||
758 | read_lock_bh(&nf_conntrack_lock); | |
759 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
760 | read_unlock_bh(&nf_conntrack_lock); | |
761 | ||
762 | return h != NULL; | |
763 | } | |
764 | ||
765 | /* There's a small race here where we may free a just-assured | |
766 | connection. Too bad: we're in trouble anyway. */ | |
9fb9cbb1 YK |
767 | static int early_drop(struct list_head *chain) |
768 | { | |
769 | /* Traverse backwards: gives us oldest, which is roughly LRU */ | |
770 | struct nf_conntrack_tuple_hash *h; | |
df0933dc | 771 | struct nf_conn *ct = NULL, *tmp; |
9fb9cbb1 YK |
772 | int dropped = 0; |
773 | ||
774 | read_lock_bh(&nf_conntrack_lock); | |
df0933dc PM |
775 | list_for_each_entry_reverse(h, chain, list) { |
776 | tmp = nf_ct_tuplehash_to_ctrack(h); | |
777 | if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { | |
778 | ct = tmp; | |
779 | atomic_inc(&ct->ct_general.use); | |
780 | break; | |
781 | } | |
9fb9cbb1 YK |
782 | } |
783 | read_unlock_bh(&nf_conntrack_lock); | |
784 | ||
785 | if (!ct) | |
786 | return dropped; | |
787 | ||
788 | if (del_timer(&ct->timeout)) { | |
789 | death_by_timeout((unsigned long)ct); | |
790 | dropped = 1; | |
791 | NF_CT_STAT_INC(early_drop); | |
792 | } | |
793 | nf_ct_put(ct); | |
794 | return dropped; | |
795 | } | |
796 | ||
9fb9cbb1 | 797 | static struct nf_conntrack_helper * |
c1d10adb | 798 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
9fb9cbb1 | 799 | { |
df0933dc PM |
800 | struct nf_conntrack_helper *h; |
801 | ||
802 | list_for_each_entry(h, &helpers, list) { | |
803 | if (nf_ct_tuple_mask_cmp(tuple, &h->tuple, &h->mask)) | |
804 | return h; | |
805 | } | |
806 | return NULL; | |
9fb9cbb1 YK |
807 | } |
808 | ||
c1d10adb PNA |
809 | struct nf_conntrack_helper * |
810 | nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple) | |
811 | { | |
812 | struct nf_conntrack_helper *helper; | |
813 | ||
814 | /* need nf_conntrack_lock to assure that helper exists until | |
815 | * try_module_get() is called */ | |
816 | read_lock_bh(&nf_conntrack_lock); | |
817 | ||
818 | helper = __nf_ct_helper_find(tuple); | |
819 | if (helper) { | |
820 | /* need to increase module usage count to assure helper will | |
821 | * not go away while the caller is e.g. busy putting a | |
822 | * conntrack in the hash that uses the helper */ | |
823 | if (!try_module_get(helper->me)) | |
824 | helper = NULL; | |
825 | } | |
826 | ||
827 | read_unlock_bh(&nf_conntrack_lock); | |
828 | ||
829 | return helper; | |
830 | } | |
831 | ||
832 | void nf_ct_helper_put(struct nf_conntrack_helper *helper) | |
833 | { | |
834 | module_put(helper->me); | |
835 | } | |
836 | ||
9fb9cbb1 YK |
837 | static struct nf_conn * |
838 | __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
839 | const struct nf_conntrack_tuple *repl, | |
840 | const struct nf_conntrack_l3proto *l3proto) | |
841 | { | |
842 | struct nf_conn *conntrack = NULL; | |
843 | u_int32_t features = 0; | |
dc808fe2 | 844 | struct nf_conntrack_helper *helper; |
9fb9cbb1 | 845 | |
dc808fe2 | 846 | if (unlikely(!nf_conntrack_hash_rnd_initted)) { |
9fb9cbb1 YK |
847 | get_random_bytes(&nf_conntrack_hash_rnd, 4); |
848 | nf_conntrack_hash_rnd_initted = 1; | |
849 | } | |
850 | ||
5251e2d2 PNA |
851 | /* We don't want any race condition at early drop stage */ |
852 | atomic_inc(&nf_conntrack_count); | |
853 | ||
9fb9cbb1 | 854 | if (nf_conntrack_max |
5251e2d2 | 855 | && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { |
9fb9cbb1 YK |
856 | unsigned int hash = hash_conntrack(orig); |
857 | /* Try dropping from this hash chain. */ | |
858 | if (!early_drop(&nf_conntrack_hash[hash])) { | |
5251e2d2 | 859 | atomic_dec(&nf_conntrack_count); |
9fb9cbb1 YK |
860 | if (net_ratelimit()) |
861 | printk(KERN_WARNING | |
862 | "nf_conntrack: table full, dropping" | |
863 | " packet.\n"); | |
864 | return ERR_PTR(-ENOMEM); | |
865 | } | |
866 | } | |
867 | ||
868 | /* find features needed by this conntrack. */ | |
869 | features = l3proto->get_features(orig); | |
dc808fe2 HW |
870 | |
871 | /* FIXME: protect helper list per RCU */ | |
9fb9cbb1 | 872 | read_lock_bh(&nf_conntrack_lock); |
dc808fe2 HW |
873 | helper = __nf_ct_helper_find(repl); |
874 | if (helper) | |
9fb9cbb1 YK |
875 | features |= NF_CT_F_HELP; |
876 | read_unlock_bh(&nf_conntrack_lock); | |
877 | ||
878 | DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); | |
879 | ||
880 | read_lock_bh(&nf_ct_cache_lock); | |
881 | ||
dc808fe2 | 882 | if (unlikely(!nf_ct_cache[features].use)) { |
9fb9cbb1 YK |
883 | DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", |
884 | features); | |
885 | goto out; | |
886 | } | |
887 | ||
888 | conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); | |
889 | if (conntrack == NULL) { | |
890 | DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); | |
891 | goto out; | |
892 | } | |
893 | ||
894 | memset(conntrack, 0, nf_ct_cache[features].size); | |
895 | conntrack->features = features; | |
9fb9cbb1 YK |
896 | atomic_set(&conntrack->ct_general.use, 1); |
897 | conntrack->ct_general.destroy = destroy_conntrack; | |
898 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; | |
899 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
900 | /* Don't set timer yet: wait for confirmation */ | |
901 | init_timer(&conntrack->timeout); | |
902 | conntrack->timeout.data = (unsigned long)conntrack; | |
903 | conntrack->timeout.function = death_by_timeout; | |
5251e2d2 | 904 | read_unlock_bh(&nf_ct_cache_lock); |
9fb9cbb1 | 905 | |
5251e2d2 | 906 | return conntrack; |
9fb9cbb1 YK |
907 | out: |
908 | read_unlock_bh(&nf_ct_cache_lock); | |
5251e2d2 | 909 | atomic_dec(&nf_conntrack_count); |
9fb9cbb1 YK |
910 | return conntrack; |
911 | } | |
912 | ||
913 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
914 | const struct nf_conntrack_tuple *repl) | |
915 | { | |
916 | struct nf_conntrack_l3proto *l3proto; | |
917 | ||
c1d10adb | 918 | l3proto = __nf_ct_l3proto_find(orig->src.l3num); |
9fb9cbb1 YK |
919 | return __nf_conntrack_alloc(orig, repl, l3proto); |
920 | } | |
921 | ||
922 | void nf_conntrack_free(struct nf_conn *conntrack) | |
923 | { | |
924 | u_int32_t features = conntrack->features; | |
925 | NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); | |
926 | DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, | |
927 | conntrack); | |
928 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); | |
929 | atomic_dec(&nf_conntrack_count); | |
930 | } | |
931 | ||
932 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
933 | failed due to stress. Otherwise it really is unclassifiable. */ | |
934 | static struct nf_conntrack_tuple_hash * | |
935 | init_conntrack(const struct nf_conntrack_tuple *tuple, | |
936 | struct nf_conntrack_l3proto *l3proto, | |
937 | struct nf_conntrack_protocol *protocol, | |
938 | struct sk_buff *skb, | |
939 | unsigned int dataoff) | |
940 | { | |
941 | struct nf_conn *conntrack; | |
942 | struct nf_conntrack_tuple repl_tuple; | |
943 | struct nf_conntrack_expect *exp; | |
944 | ||
945 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, protocol)) { | |
946 | DEBUGP("Can't invert tuple.\n"); | |
947 | return NULL; | |
948 | } | |
949 | ||
950 | conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto); | |
951 | if (conntrack == NULL || IS_ERR(conntrack)) { | |
952 | DEBUGP("Can't allocate conntrack.\n"); | |
953 | return (struct nf_conntrack_tuple_hash *)conntrack; | |
954 | } | |
955 | ||
956 | if (!protocol->new(conntrack, skb, dataoff)) { | |
957 | nf_conntrack_free(conntrack); | |
958 | DEBUGP("init conntrack: can't track with proto module\n"); | |
959 | return NULL; | |
960 | } | |
961 | ||
962 | write_lock_bh(&nf_conntrack_lock); | |
963 | exp = find_expectation(tuple); | |
964 | ||
965 | if (exp) { | |
966 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", | |
967 | conntrack, exp); | |
968 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
969 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
970 | conntrack->master = exp->master; | |
971 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
972 | conntrack->mark = exp->master->mark; | |
7c9728c3 JM |
973 | #endif |
974 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
975 | conntrack->secmark = exp->master->secmark; | |
9fb9cbb1 YK |
976 | #endif |
977 | nf_conntrack_get(&conntrack->master->ct_general); | |
978 | NF_CT_STAT_INC(expect_new); | |
22e7410b YK |
979 | } else { |
980 | struct nf_conn_help *help = nfct_help(conntrack); | |
981 | ||
982 | if (help) | |
983 | help->helper = __nf_ct_helper_find(&repl_tuple); | |
9fb9cbb1 | 984 | NF_CT_STAT_INC(new); |
22e7410b | 985 | } |
9fb9cbb1 YK |
986 | |
987 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
988 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); | |
989 | ||
990 | write_unlock_bh(&nf_conntrack_lock); | |
991 | ||
992 | if (exp) { | |
993 | if (exp->expectfn) | |
994 | exp->expectfn(conntrack, exp); | |
995 | nf_conntrack_expect_put(exp); | |
996 | } | |
997 | ||
998 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
999 | } | |
1000 | ||
1001 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
1002 | static inline struct nf_conn * | |
1003 | resolve_normal_ct(struct sk_buff *skb, | |
1004 | unsigned int dataoff, | |
1005 | u_int16_t l3num, | |
1006 | u_int8_t protonum, | |
1007 | struct nf_conntrack_l3proto *l3proto, | |
1008 | struct nf_conntrack_protocol *proto, | |
1009 | int *set_reply, | |
1010 | enum ip_conntrack_info *ctinfo) | |
1011 | { | |
1012 | struct nf_conntrack_tuple tuple; | |
1013 | struct nf_conntrack_tuple_hash *h; | |
1014 | struct nf_conn *ct; | |
1015 | ||
1016 | if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), | |
1017 | dataoff, l3num, protonum, &tuple, l3proto, | |
1018 | proto)) { | |
1019 | DEBUGP("resolve_normal_ct: Can't get tuple\n"); | |
1020 | return NULL; | |
1021 | } | |
1022 | ||
1023 | /* look for tuple match */ | |
1024 | h = nf_conntrack_find_get(&tuple, NULL); | |
1025 | if (!h) { | |
1026 | h = init_conntrack(&tuple, l3proto, proto, skb, dataoff); | |
1027 | if (!h) | |
1028 | return NULL; | |
1029 | if (IS_ERR(h)) | |
1030 | return (void *)h; | |
1031 | } | |
1032 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1033 | ||
1034 | /* It exists; we have (non-exclusive) reference. */ | |
1035 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
1036 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
1037 | /* Please set reply bit if this packet OK */ | |
1038 | *set_reply = 1; | |
1039 | } else { | |
1040 | /* Once we've had two way comms, always ESTABLISHED. */ | |
1041 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
1042 | DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); | |
1043 | *ctinfo = IP_CT_ESTABLISHED; | |
1044 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
1045 | DEBUGP("nf_conntrack_in: related packet for %p\n", ct); | |
1046 | *ctinfo = IP_CT_RELATED; | |
1047 | } else { | |
1048 | DEBUGP("nf_conntrack_in: new packet for %p\n", ct); | |
1049 | *ctinfo = IP_CT_NEW; | |
1050 | } | |
1051 | *set_reply = 0; | |
1052 | } | |
1053 | skb->nfct = &ct->ct_general; | |
1054 | skb->nfctinfo = *ctinfo; | |
1055 | return ct; | |
1056 | } | |
1057 | ||
1058 | unsigned int | |
1059 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) | |
1060 | { | |
1061 | struct nf_conn *ct; | |
1062 | enum ip_conntrack_info ctinfo; | |
1063 | struct nf_conntrack_l3proto *l3proto; | |
1064 | struct nf_conntrack_protocol *proto; | |
1065 | unsigned int dataoff; | |
1066 | u_int8_t protonum; | |
1067 | int set_reply = 0; | |
1068 | int ret; | |
1069 | ||
1070 | /* Previously seen (loopback or untracked)? Ignore. */ | |
1071 | if ((*pskb)->nfct) { | |
1072 | NF_CT_STAT_INC(ignore); | |
1073 | return NF_ACCEPT; | |
1074 | } | |
1075 | ||
c1d10adb | 1076 | l3proto = __nf_ct_l3proto_find((u_int16_t)pf); |
9fb9cbb1 YK |
1077 | if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { |
1078 | DEBUGP("not prepared to track yet or error occured\n"); | |
1079 | return -ret; | |
1080 | } | |
1081 | ||
c1d10adb | 1082 | proto = __nf_ct_proto_find((u_int16_t)pf, protonum); |
9fb9cbb1 YK |
1083 | |
1084 | /* It may be an special packet, error, unclean... | |
1085 | * inverse of the return code tells to the netfilter | |
1086 | * core what to do with the packet. */ | |
1087 | if (proto->error != NULL && | |
1088 | (ret = proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { | |
1089 | NF_CT_STAT_INC(error); | |
1090 | NF_CT_STAT_INC(invalid); | |
1091 | return -ret; | |
1092 | } | |
1093 | ||
1094 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, proto, | |
1095 | &set_reply, &ctinfo); | |
1096 | if (!ct) { | |
1097 | /* Not valid part of a connection */ | |
1098 | NF_CT_STAT_INC(invalid); | |
1099 | return NF_ACCEPT; | |
1100 | } | |
1101 | ||
1102 | if (IS_ERR(ct)) { | |
1103 | /* Too stressed to deal. */ | |
1104 | NF_CT_STAT_INC(drop); | |
1105 | return NF_DROP; | |
1106 | } | |
1107 | ||
1108 | NF_CT_ASSERT((*pskb)->nfct); | |
1109 | ||
1110 | ret = proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); | |
1111 | if (ret < 0) { | |
1112 | /* Invalid: inverse of the return code tells | |
1113 | * the netfilter core what to do */ | |
1114 | DEBUGP("nf_conntrack_in: Can't track with proto module\n"); | |
1115 | nf_conntrack_put((*pskb)->nfct); | |
1116 | (*pskb)->nfct = NULL; | |
1117 | NF_CT_STAT_INC(invalid); | |
1118 | return -ret; | |
1119 | } | |
1120 | ||
1121 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
1122 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); | |
1123 | ||
1124 | return ret; | |
1125 | } | |
1126 | ||
1127 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
1128 | const struct nf_conntrack_tuple *orig) | |
1129 | { | |
1130 | return nf_ct_invert_tuple(inverse, orig, | |
c1d10adb PNA |
1131 | __nf_ct_l3proto_find(orig->src.l3num), |
1132 | __nf_ct_proto_find(orig->src.l3num, | |
1133 | orig->dst.protonum)); | |
9fb9cbb1 YK |
1134 | } |
1135 | ||
1136 | /* Would two expected things clash? */ | |
1137 | static inline int expect_clash(const struct nf_conntrack_expect *a, | |
1138 | const struct nf_conntrack_expect *b) | |
1139 | { | |
1140 | /* Part covered by intersection of masks must be unequal, | |
1141 | otherwise they clash */ | |
1142 | struct nf_conntrack_tuple intersect_mask; | |
1143 | int count; | |
1144 | ||
1145 | intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num; | |
1146 | intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all; | |
1147 | intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all; | |
1148 | intersect_mask.dst.protonum = a->mask.dst.protonum | |
1149 | & b->mask.dst.protonum; | |
1150 | ||
1151 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1152 | intersect_mask.src.u3.all[count] = | |
1153 | a->mask.src.u3.all[count] & b->mask.src.u3.all[count]; | |
1154 | } | |
1155 | ||
1156 | for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){ | |
1157 | intersect_mask.dst.u3.all[count] = | |
1158 | a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count]; | |
1159 | } | |
1160 | ||
1161 | return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask); | |
1162 | } | |
1163 | ||
1164 | static inline int expect_matches(const struct nf_conntrack_expect *a, | |
1165 | const struct nf_conntrack_expect *b) | |
1166 | { | |
1167 | return a->master == b->master | |
1168 | && nf_ct_tuple_equal(&a->tuple, &b->tuple) | |
1169 | && nf_ct_tuple_equal(&a->mask, &b->mask); | |
1170 | } | |
1171 | ||
1172 | /* Generally a bad idea to call this: could have matched already. */ | |
1173 | void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp) | |
1174 | { | |
1175 | struct nf_conntrack_expect *i; | |
1176 | ||
1177 | write_lock_bh(&nf_conntrack_lock); | |
1178 | /* choose the the oldest expectation to evict */ | |
1179 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1180 | if (expect_matches(i, exp) && del_timer(&i->timeout)) { | |
1181 | nf_ct_unlink_expect(i); | |
1182 | write_unlock_bh(&nf_conntrack_lock); | |
1183 | nf_conntrack_expect_put(i); | |
1184 | return; | |
1185 | } | |
1186 | } | |
1187 | write_unlock_bh(&nf_conntrack_lock); | |
1188 | } | |
1189 | ||
1190 | /* We don't increase the master conntrack refcount for non-fulfilled | |
1191 | * conntracks. During the conntrack destruction, the expectations are | |
1192 | * always killed before the conntrack itself */ | |
1193 | struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me) | |
1194 | { | |
1195 | struct nf_conntrack_expect *new; | |
1196 | ||
1197 | new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC); | |
1198 | if (!new) { | |
1199 | DEBUGP("expect_related: OOM allocating expect\n"); | |
1200 | return NULL; | |
1201 | } | |
1202 | new->master = me; | |
1203 | atomic_set(&new->use, 1); | |
1204 | return new; | |
1205 | } | |
1206 | ||
1207 | void nf_conntrack_expect_put(struct nf_conntrack_expect *exp) | |
1208 | { | |
1209 | if (atomic_dec_and_test(&exp->use)) | |
1210 | kmem_cache_free(nf_conntrack_expect_cachep, exp); | |
1211 | } | |
1212 | ||
1213 | static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp) | |
1214 | { | |
dc808fe2 HW |
1215 | struct nf_conn_help *master_help = nfct_help(exp->master); |
1216 | ||
9fb9cbb1 | 1217 | atomic_inc(&exp->use); |
dc808fe2 | 1218 | master_help->expecting++; |
9fb9cbb1 YK |
1219 | list_add(&exp->list, &nf_conntrack_expect_list); |
1220 | ||
1221 | init_timer(&exp->timeout); | |
1222 | exp->timeout.data = (unsigned long)exp; | |
1223 | exp->timeout.function = expectation_timed_out; | |
dc808fe2 | 1224 | exp->timeout.expires = jiffies + master_help->helper->timeout * HZ; |
9fb9cbb1 YK |
1225 | add_timer(&exp->timeout); |
1226 | ||
c1d10adb | 1227 | exp->id = ++nf_conntrack_expect_next_id; |
9fb9cbb1 YK |
1228 | atomic_inc(&exp->use); |
1229 | NF_CT_STAT_INC(expect_create); | |
1230 | } | |
1231 | ||
1232 | /* Race with expectations being used means we could have none to find; OK. */ | |
1233 | static void evict_oldest_expect(struct nf_conn *master) | |
1234 | { | |
1235 | struct nf_conntrack_expect *i; | |
1236 | ||
1237 | list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) { | |
1238 | if (i->master == master) { | |
1239 | if (del_timer(&i->timeout)) { | |
1240 | nf_ct_unlink_expect(i); | |
1241 | nf_conntrack_expect_put(i); | |
1242 | } | |
1243 | break; | |
1244 | } | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | static inline int refresh_timer(struct nf_conntrack_expect *i) | |
1249 | { | |
dc808fe2 HW |
1250 | struct nf_conn_help *master_help = nfct_help(i->master); |
1251 | ||
9fb9cbb1 YK |
1252 | if (!del_timer(&i->timeout)) |
1253 | return 0; | |
1254 | ||
dc808fe2 | 1255 | i->timeout.expires = jiffies + master_help->helper->timeout*HZ; |
9fb9cbb1 YK |
1256 | add_timer(&i->timeout); |
1257 | return 1; | |
1258 | } | |
1259 | ||
1260 | int nf_conntrack_expect_related(struct nf_conntrack_expect *expect) | |
1261 | { | |
1262 | struct nf_conntrack_expect *i; | |
d695aa8a | 1263 | struct nf_conn *master = expect->master; |
dc808fe2 | 1264 | struct nf_conn_help *master_help = nfct_help(master); |
9fb9cbb1 YK |
1265 | int ret; |
1266 | ||
dc808fe2 HW |
1267 | NF_CT_ASSERT(master_help); |
1268 | ||
9fb9cbb1 YK |
1269 | DEBUGP("nf_conntrack_expect_related %p\n", related_to); |
1270 | DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple); | |
1271 | DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask); | |
1272 | ||
1273 | write_lock_bh(&nf_conntrack_lock); | |
1274 | list_for_each_entry(i, &nf_conntrack_expect_list, list) { | |
1275 | if (expect_matches(i, expect)) { | |
1276 | /* Refresh timer: if it's dying, ignore.. */ | |
1277 | if (refresh_timer(i)) { | |
1278 | ret = 0; | |
1279 | goto out; | |
1280 | } | |
1281 | } else if (expect_clash(i, expect)) { | |
1282 | ret = -EBUSY; | |
1283 | goto out; | |
1284 | } | |
1285 | } | |
1286 | /* Will be over limit? */ | |
dc808fe2 HW |
1287 | if (master_help->helper->max_expected && |
1288 | master_help->expecting >= master_help->helper->max_expected) | |
d695aa8a | 1289 | evict_oldest_expect(master); |
9fb9cbb1 YK |
1290 | |
1291 | nf_conntrack_expect_insert(expect); | |
1292 | nf_conntrack_expect_event(IPEXP_NEW, expect); | |
1293 | ret = 0; | |
1294 | out: | |
1295 | write_unlock_bh(&nf_conntrack_lock); | |
1296 | return ret; | |
1297 | } | |
1298 | ||
9fb9cbb1 YK |
1299 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
1300 | { | |
1301 | int ret; | |
1302 | BUG_ON(me->timeout == 0); | |
1303 | ||
1304 | ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help", | |
1305 | sizeof(struct nf_conn) | |
dc808fe2 HW |
1306 | + sizeof(struct nf_conn_help) |
1307 | + __alignof__(struct nf_conn_help)); | |
9fb9cbb1 YK |
1308 | if (ret < 0) { |
1309 | printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n"); | |
1310 | return ret; | |
1311 | } | |
1312 | write_lock_bh(&nf_conntrack_lock); | |
df0933dc | 1313 | list_add(&me->list, &helpers); |
9fb9cbb1 YK |
1314 | write_unlock_bh(&nf_conntrack_lock); |
1315 | ||
1316 | return 0; | |
1317 | } | |
1318 | ||
c1d10adb PNA |
1319 | struct nf_conntrack_helper * |
1320 | __nf_conntrack_helper_find_byname(const char *name) | |
1321 | { | |
1322 | struct nf_conntrack_helper *h; | |
1323 | ||
1324 | list_for_each_entry(h, &helpers, list) { | |
1325 | if (!strcmp(h->name, name)) | |
1326 | return h; | |
1327 | } | |
1328 | ||
1329 | return NULL; | |
1330 | } | |
1331 | ||
df0933dc PM |
1332 | static inline void unhelp(struct nf_conntrack_tuple_hash *i, |
1333 | const struct nf_conntrack_helper *me) | |
9fb9cbb1 | 1334 | { |
dc808fe2 HW |
1335 | struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i); |
1336 | struct nf_conn_help *help = nfct_help(ct); | |
1337 | ||
1338 | if (help && help->helper == me) { | |
1339 | nf_conntrack_event(IPCT_HELPER, ct); | |
1340 | help->helper = NULL; | |
9fb9cbb1 | 1341 | } |
9fb9cbb1 YK |
1342 | } |
1343 | ||
1344 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) | |
1345 | { | |
1346 | unsigned int i; | |
df0933dc | 1347 | struct nf_conntrack_tuple_hash *h; |
9fb9cbb1 YK |
1348 | struct nf_conntrack_expect *exp, *tmp; |
1349 | ||
1350 | /* Need write lock here, to delete helper. */ | |
1351 | write_lock_bh(&nf_conntrack_lock); | |
df0933dc | 1352 | list_del(&me->list); |
9fb9cbb1 YK |
1353 | |
1354 | /* Get rid of expectations */ | |
1355 | list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) { | |
dc808fe2 HW |
1356 | struct nf_conn_help *help = nfct_help(exp->master); |
1357 | if (help->helper == me && del_timer(&exp->timeout)) { | |
9fb9cbb1 YK |
1358 | nf_ct_unlink_expect(exp); |
1359 | nf_conntrack_expect_put(exp); | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | /* Get rid of expecteds, set helpers to NULL. */ | |
df0933dc PM |
1364 | list_for_each_entry(h, &unconfirmed, list) |
1365 | unhelp(h, me); | |
1366 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
1367 | list_for_each_entry(h, &nf_conntrack_hash[i], list) | |
1368 | unhelp(h, me); | |
1369 | } | |
9fb9cbb1 YK |
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 | ||
997ae831 EL |
1390 | /* Only update if this is not a fixed timeout */ |
1391 | if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { | |
1392 | write_unlock_bh(&nf_conntrack_lock); | |
1393 | return; | |
1394 | } | |
1395 | ||
9fb9cbb1 YK |
1396 | /* If not in hash table, timer will not be active yet */ |
1397 | if (!nf_ct_is_confirmed(ct)) { | |
1398 | ct->timeout.expires = extra_jiffies; | |
1399 | event = IPCT_REFRESH; | |
1400 | } else { | |
1401 | /* Need del_timer for race avoidance (may already be dying). */ | |
1402 | if (del_timer(&ct->timeout)) { | |
1403 | ct->timeout.expires = jiffies + extra_jiffies; | |
1404 | add_timer(&ct->timeout); | |
1405 | event = IPCT_REFRESH; | |
1406 | } | |
1407 | } | |
1408 | ||
1409 | #ifdef CONFIG_NF_CT_ACCT | |
1410 | if (do_acct) { | |
1411 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
1412 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
1413 | skb->len - (unsigned int)(skb->nh.raw - skb->data); | |
1414 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) | |
1415 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
1416 | event |= IPCT_COUNTER_FILLING; | |
1417 | } | |
1418 | #endif | |
1419 | ||
1420 | write_unlock_bh(&nf_conntrack_lock); | |
1421 | ||
1422 | /* must be unlocked when calling event cache */ | |
1423 | if (event) | |
1424 | nf_conntrack_event_cache(event, skb); | |
1425 | } | |
1426 | ||
c1d10adb PNA |
1427 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
1428 | defined(CONFIG_NF_CT_NETLINK_MODULE) | |
1429 | ||
1430 | #include <linux/netfilter/nfnetlink.h> | |
1431 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
57b47a53 IM |
1432 | #include <linux/mutex.h> |
1433 | ||
c1d10adb PNA |
1434 | |
1435 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
1436 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
1437 | * or depend on ctnetlink */ | |
1438 | int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
1439 | const struct nf_conntrack_tuple *tuple) | |
1440 | { | |
1441 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), | |
1442 | &tuple->src.u.tcp.port); | |
1443 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), | |
1444 | &tuple->dst.u.tcp.port); | |
1445 | return 0; | |
1446 | ||
1447 | nfattr_failure: | |
1448 | return -1; | |
1449 | } | |
1450 | ||
1451 | static const size_t cta_min_proto[CTA_PROTO_MAX] = { | |
1452 | [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), | |
1453 | [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) | |
1454 | }; | |
1455 | ||
1456 | int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
1457 | struct nf_conntrack_tuple *t) | |
1458 | { | |
1459 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
1460 | return -EINVAL; | |
1461 | ||
1462 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
1463 | return -EINVAL; | |
1464 | ||
1465 | t->src.u.tcp.port = | |
1466 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); | |
1467 | t->dst.u.tcp.port = | |
1468 | *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); | |
1469 | ||
1470 | return 0; | |
1471 | } | |
1472 | #endif | |
1473 | ||
9fb9cbb1 YK |
1474 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
1475 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1476 | { | |
1477 | struct nf_conn *ct; | |
1478 | enum ip_conntrack_info ctinfo; | |
1479 | ||
1480 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1481 | ct = nf_ct_get(skb, &ctinfo); | |
1482 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1483 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
1484 | else | |
1485 | ctinfo = IP_CT_RELATED; | |
1486 | ||
1487 | /* Attach to new skbuff, and increment count */ | |
1488 | nskb->nfct = &ct->ct_general; | |
1489 | nskb->nfctinfo = ctinfo; | |
1490 | nf_conntrack_get(nskb->nfct); | |
1491 | } | |
1492 | ||
1493 | static inline int | |
1494 | do_iter(const struct nf_conntrack_tuple_hash *i, | |
1495 | int (*iter)(struct nf_conn *i, void *data), | |
1496 | void *data) | |
1497 | { | |
1498 | return iter(nf_ct_tuplehash_to_ctrack(i), data); | |
1499 | } | |
1500 | ||
1501 | /* Bring out ya dead! */ | |
df0933dc | 1502 | static struct nf_conn * |
9fb9cbb1 YK |
1503 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), |
1504 | void *data, unsigned int *bucket) | |
1505 | { | |
df0933dc PM |
1506 | struct nf_conntrack_tuple_hash *h; |
1507 | struct nf_conn *ct; | |
9fb9cbb1 YK |
1508 | |
1509 | write_lock_bh(&nf_conntrack_lock); | |
1510 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { | |
df0933dc PM |
1511 | list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) { |
1512 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1513 | if (iter(ct, data)) | |
1514 | goto found; | |
1515 | } | |
9fb9cbb1 | 1516 | } |
df0933dc PM |
1517 | list_for_each_entry(h, &unconfirmed, list) { |
1518 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1519 | if (iter(ct, data)) | |
1520 | goto found; | |
1521 | } | |
c073e3fa | 1522 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc PM |
1523 | return NULL; |
1524 | found: | |
c073e3fa | 1525 | atomic_inc(&ct->ct_general.use); |
9fb9cbb1 | 1526 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc | 1527 | return ct; |
9fb9cbb1 YK |
1528 | } |
1529 | ||
1530 | void | |
1531 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) | |
1532 | { | |
df0933dc | 1533 | struct nf_conn *ct; |
9fb9cbb1 YK |
1534 | unsigned int bucket = 0; |
1535 | ||
df0933dc | 1536 | while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { |
9fb9cbb1 YK |
1537 | /* Time to push up daises... */ |
1538 | if (del_timer(&ct->timeout)) | |
1539 | death_by_timeout((unsigned long)ct); | |
1540 | /* ... else the timer will get him soon. */ | |
1541 | ||
1542 | nf_ct_put(ct); | |
1543 | } | |
1544 | } | |
1545 | ||
1546 | static int kill_all(struct nf_conn *i, void *data) | |
1547 | { | |
1548 | return 1; | |
1549 | } | |
1550 | ||
1551 | static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) | |
1552 | { | |
1553 | if (vmalloced) | |
1554 | vfree(hash); | |
1555 | else | |
1556 | free_pages((unsigned long)hash, | |
1557 | get_order(sizeof(struct list_head) * size)); | |
1558 | } | |
1559 | ||
c1d10adb PNA |
1560 | void nf_conntrack_flush() |
1561 | { | |
1562 | nf_ct_iterate_cleanup(kill_all, NULL); | |
1563 | } | |
1564 | ||
9fb9cbb1 YK |
1565 | /* Mishearing the voices in his head, our hero wonders how he's |
1566 | supposed to kill the mall. */ | |
1567 | void nf_conntrack_cleanup(void) | |
1568 | { | |
1569 | int i; | |
1570 | ||
7d3cdc6b YK |
1571 | ip_ct_attach = NULL; |
1572 | ||
9fb9cbb1 YK |
1573 | /* This makes sure all current packets have passed through |
1574 | netfilter framework. Roll on, two-stage module | |
1575 | delete... */ | |
1576 | synchronize_net(); | |
1577 | ||
1578 | nf_ct_event_cache_flush(); | |
1579 | i_see_dead_people: | |
c1d10adb | 1580 | nf_conntrack_flush(); |
9fb9cbb1 YK |
1581 | if (atomic_read(&nf_conntrack_count) != 0) { |
1582 | schedule(); | |
1583 | goto i_see_dead_people; | |
1584 | } | |
6636568c PM |
1585 | /* wait until all references to nf_conntrack_untracked are dropped */ |
1586 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) | |
1587 | schedule(); | |
9fb9cbb1 YK |
1588 | |
1589 | for (i = 0; i < NF_CT_F_NUM; i++) { | |
1590 | if (nf_ct_cache[i].use == 0) | |
1591 | continue; | |
1592 | ||
1593 | NF_CT_ASSERT(nf_ct_cache[i].use == 1); | |
1594 | nf_ct_cache[i].use = 1; | |
1595 | nf_conntrack_unregister_cache(i); | |
1596 | } | |
1597 | kmem_cache_destroy(nf_conntrack_expect_cachep); | |
1598 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1599 | nf_conntrack_htable_size); | |
5a6f294e KK |
1600 | |
1601 | /* free l3proto protocol tables */ | |
1602 | for (i = 0; i < PF_MAX; i++) | |
1603 | if (nf_ct_protos[i]) { | |
1604 | kfree(nf_ct_protos[i]); | |
1605 | nf_ct_protos[i] = NULL; | |
1606 | } | |
9fb9cbb1 YK |
1607 | } |
1608 | ||
1609 | static struct list_head *alloc_hashtable(int size, int *vmalloced) | |
1610 | { | |
1611 | struct list_head *hash; | |
1612 | unsigned int i; | |
1613 | ||
1614 | *vmalloced = 0; | |
1615 | hash = (void*)__get_free_pages(GFP_KERNEL, | |
1616 | get_order(sizeof(struct list_head) | |
1617 | * size)); | |
1618 | if (!hash) { | |
1619 | *vmalloced = 1; | |
1620 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
1621 | hash = vmalloc(sizeof(struct list_head) * size); | |
1622 | } | |
1623 | ||
1624 | if (hash) | |
1625 | for (i = 0; i < size; i++) | |
1626 | INIT_LIST_HEAD(&hash[i]); | |
1627 | ||
1628 | return hash; | |
1629 | } | |
1630 | ||
1631 | int set_hashsize(const char *val, struct kernel_param *kp) | |
1632 | { | |
1633 | int i, bucket, hashsize, vmalloced; | |
1634 | int old_vmalloced, old_size; | |
1635 | int rnd; | |
1636 | struct list_head *hash, *old_hash; | |
1637 | struct nf_conntrack_tuple_hash *h; | |
1638 | ||
1639 | /* On boot, we can set this without any fancy locking. */ | |
1640 | if (!nf_conntrack_htable_size) | |
1641 | return param_set_uint(val, kp); | |
1642 | ||
1643 | hashsize = simple_strtol(val, NULL, 0); | |
1644 | if (!hashsize) | |
1645 | return -EINVAL; | |
1646 | ||
1647 | hash = alloc_hashtable(hashsize, &vmalloced); | |
1648 | if (!hash) | |
1649 | return -ENOMEM; | |
1650 | ||
1651 | /* We have to rehahs for the new table anyway, so we also can | |
1652 | * use a newrandom seed */ | |
1653 | get_random_bytes(&rnd, 4); | |
1654 | ||
1655 | write_lock_bh(&nf_conntrack_lock); | |
1656 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
1657 | while (!list_empty(&nf_conntrack_hash[i])) { | |
1658 | h = list_entry(nf_conntrack_hash[i].next, | |
1659 | struct nf_conntrack_tuple_hash, list); | |
1660 | list_del(&h->list); | |
1661 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); | |
1662 | list_add_tail(&h->list, &hash[bucket]); | |
1663 | } | |
1664 | } | |
1665 | old_size = nf_conntrack_htable_size; | |
1666 | old_vmalloced = nf_conntrack_vmalloc; | |
1667 | old_hash = nf_conntrack_hash; | |
1668 | ||
1669 | nf_conntrack_htable_size = hashsize; | |
1670 | nf_conntrack_vmalloc = vmalloced; | |
1671 | nf_conntrack_hash = hash; | |
1672 | nf_conntrack_hash_rnd = rnd; | |
1673 | write_unlock_bh(&nf_conntrack_lock); | |
1674 | ||
1675 | free_conntrack_hash(old_hash, old_vmalloced, old_size); | |
1676 | return 0; | |
1677 | } | |
1678 | ||
1679 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1680 | &nf_conntrack_htable_size, 0600); | |
1681 | ||
1682 | int __init nf_conntrack_init(void) | |
1683 | { | |
1684 | unsigned int i; | |
1685 | int ret; | |
1686 | ||
1687 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1688 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ | |
1689 | if (!nf_conntrack_htable_size) { | |
1690 | nf_conntrack_htable_size | |
1691 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
1692 | / sizeof(struct list_head)); | |
1693 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1694 | nf_conntrack_htable_size = 8192; | |
1695 | if (nf_conntrack_htable_size < 16) | |
1696 | nf_conntrack_htable_size = 16; | |
1697 | } | |
1698 | nf_conntrack_max = 8 * nf_conntrack_htable_size; | |
1699 | ||
1700 | printk("nf_conntrack version %s (%u buckets, %d max)\n", | |
1701 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1702 | nf_conntrack_max); | |
1703 | ||
1704 | nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, | |
1705 | &nf_conntrack_vmalloc); | |
1706 | if (!nf_conntrack_hash) { | |
1707 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1708 | goto err_out; | |
1709 | } | |
1710 | ||
1711 | ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", | |
dc808fe2 | 1712 | sizeof(struct nf_conn)); |
9fb9cbb1 YK |
1713 | if (ret < 0) { |
1714 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); | |
1715 | goto err_free_hash; | |
1716 | } | |
1717 | ||
1718 | nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", | |
1719 | sizeof(struct nf_conntrack_expect), | |
1720 | 0, 0, NULL, NULL); | |
1721 | if (!nf_conntrack_expect_cachep) { | |
1722 | printk(KERN_ERR "Unable to create nf_expect slab cache\n"); | |
1723 | goto err_free_conntrack_slab; | |
1724 | } | |
1725 | ||
1726 | /* Don't NEED lock here, but good form anyway. */ | |
1727 | write_lock_bh(&nf_conntrack_lock); | |
1728 | for (i = 0; i < PF_MAX; i++) | |
1729 | nf_ct_l3protos[i] = &nf_conntrack_generic_l3proto; | |
1730 | write_unlock_bh(&nf_conntrack_lock); | |
1731 | ||
7d3cdc6b YK |
1732 | /* For use by REJECT target */ |
1733 | ip_ct_attach = __nf_conntrack_attach; | |
1734 | ||
9fb9cbb1 YK |
1735 | /* Set up fake conntrack: |
1736 | - to never be deleted, not in any hashes */ | |
1737 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); | |
1738 | /* - and look it like as a confirmed connection */ | |
1739 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); | |
1740 | ||
1741 | return ret; | |
1742 | ||
1743 | err_free_conntrack_slab: | |
1744 | nf_conntrack_unregister_cache(NF_CT_F_BASIC); | |
1745 | err_free_hash: | |
1746 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1747 | nf_conntrack_htable_size); | |
1748 | err_out: | |
1749 | return -ENOMEM; | |
1750 | } |