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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> | |
d7fe0f24 | 49 | #include <linux/mm.h> |
9fb9cbb1 | 50 | |
9fb9cbb1 YK |
51 | #include <net/netfilter/nf_conntrack.h> |
52 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
605dcad6 | 53 | #include <net/netfilter/nf_conntrack_l4proto.h> |
77ab9cff | 54 | #include <net/netfilter/nf_conntrack_expect.h> |
9fb9cbb1 YK |
55 | #include <net/netfilter/nf_conntrack_helper.h> |
56 | #include <net/netfilter/nf_conntrack_core.h> | |
9fb9cbb1 | 57 | |
dc808fe2 | 58 | #define NF_CONNTRACK_VERSION "0.5.0" |
9fb9cbb1 YK |
59 | |
60 | #if 0 | |
61 | #define DEBUGP printk | |
62 | #else | |
63 | #define DEBUGP(format, args...) | |
64 | #endif | |
65 | ||
66 | DEFINE_RWLOCK(nf_conntrack_lock); | |
13b18339 | 67 | EXPORT_SYMBOL_GPL(nf_conntrack_lock); |
9fb9cbb1 YK |
68 | |
69 | /* nf_conntrack_standalone needs this */ | |
70 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); | |
a999e683 | 71 | EXPORT_SYMBOL_GPL(nf_conntrack_count); |
9fb9cbb1 | 72 | |
13b18339 PM |
73 | void (*nf_conntrack_destroyed)(struct nf_conn *conntrack); |
74 | EXPORT_SYMBOL_GPL(nf_conntrack_destroyed); | |
75 | ||
e2b7606c | 76 | unsigned int nf_conntrack_htable_size __read_mostly; |
13b18339 PM |
77 | EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); |
78 | ||
94aec08e | 79 | int nf_conntrack_max __read_mostly; |
a999e683 | 80 | EXPORT_SYMBOL_GPL(nf_conntrack_max); |
13b18339 | 81 | |
1192e403 | 82 | struct list_head *nf_conntrack_hash __read_mostly; |
13b18339 PM |
83 | EXPORT_SYMBOL_GPL(nf_conntrack_hash); |
84 | ||
e2b7606c | 85 | struct nf_conn nf_conntrack_untracked __read_mostly; |
13b18339 PM |
86 | EXPORT_SYMBOL_GPL(nf_conntrack_untracked); |
87 | ||
94aec08e | 88 | unsigned int nf_ct_log_invalid __read_mostly; |
7e5d03bb | 89 | LIST_HEAD(unconfirmed); |
1192e403 | 90 | static int nf_conntrack_vmalloc __read_mostly; |
9fb9cbb1 | 91 | |
4e3882f7 | 92 | static unsigned int nf_conntrack_next_id; |
77ab9cff | 93 | |
9fb9cbb1 YK |
94 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); |
95 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); | |
96 | ||
97 | /* | |
98 | * This scheme offers various size of "struct nf_conn" dependent on | |
99 | * features(helper, nat, ...) | |
100 | */ | |
101 | ||
102 | #define NF_CT_FEATURES_NAMELEN 256 | |
103 | static struct { | |
104 | /* name of slab cache. printed in /proc/slabinfo */ | |
105 | char *name; | |
106 | ||
107 | /* size of slab cache */ | |
108 | size_t size; | |
109 | ||
110 | /* slab cache pointer */ | |
111 | kmem_cache_t *cachep; | |
112 | ||
113 | /* allocated slab cache + modules which uses this slab cache */ | |
114 | int use; | |
115 | ||
9fb9cbb1 YK |
116 | } nf_ct_cache[NF_CT_F_NUM]; |
117 | ||
118 | /* protect members of nf_ct_cache except of "use" */ | |
119 | DEFINE_RWLOCK(nf_ct_cache_lock); | |
120 | ||
121 | /* This avoids calling kmem_cache_create() with same name simultaneously */ | |
57b47a53 | 122 | static DEFINE_MUTEX(nf_ct_cache_mutex); |
9fb9cbb1 | 123 | |
9fb9cbb1 YK |
124 | static int nf_conntrack_hash_rnd_initted; |
125 | static unsigned int nf_conntrack_hash_rnd; | |
126 | ||
127 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
128 | unsigned int size, unsigned int rnd) | |
129 | { | |
130 | unsigned int a, b; | |
131 | a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all), | |
132 | ((tuple->src.l3num) << 16) | tuple->dst.protonum); | |
133 | b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all), | |
134 | (tuple->src.u.all << 16) | tuple->dst.u.all); | |
135 | ||
136 | return jhash_2words(a, b, rnd) % size; | |
137 | } | |
138 | ||
139 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) | |
140 | { | |
141 | return __hash_conntrack(tuple, nf_conntrack_htable_size, | |
142 | nf_conntrack_hash_rnd); | |
143 | } | |
144 | ||
9fb9cbb1 | 145 | int nf_conntrack_register_cache(u_int32_t features, const char *name, |
dc808fe2 | 146 | size_t size) |
9fb9cbb1 YK |
147 | { |
148 | int ret = 0; | |
149 | char *cache_name; | |
150 | kmem_cache_t *cachep; | |
151 | ||
152 | DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n", | |
153 | features, name, size); | |
154 | ||
155 | if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) { | |
156 | DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n", | |
157 | features); | |
158 | return -EINVAL; | |
159 | } | |
160 | ||
57b47a53 | 161 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
162 | |
163 | write_lock_bh(&nf_ct_cache_lock); | |
164 | /* e.g: multiple helpers are loaded */ | |
165 | if (nf_ct_cache[features].use > 0) { | |
166 | DEBUGP("nf_conntrack_register_cache: already resisterd.\n"); | |
167 | if ((!strncmp(nf_ct_cache[features].name, name, | |
168 | NF_CT_FEATURES_NAMELEN)) | |
dc808fe2 | 169 | && nf_ct_cache[features].size == size) { |
9fb9cbb1 YK |
170 | DEBUGP("nf_conntrack_register_cache: reusing.\n"); |
171 | nf_ct_cache[features].use++; | |
172 | ret = 0; | |
173 | } else | |
174 | ret = -EBUSY; | |
175 | ||
176 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 177 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
178 | return ret; |
179 | } | |
180 | write_unlock_bh(&nf_ct_cache_lock); | |
181 | ||
182 | /* | |
183 | * The memory space for name of slab cache must be alive until | |
184 | * cache is destroyed. | |
185 | */ | |
186 | cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC); | |
187 | if (cache_name == NULL) { | |
188 | DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n"); | |
189 | ret = -ENOMEM; | |
190 | goto out_up_mutex; | |
191 | } | |
192 | ||
193 | if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN) | |
194 | >= NF_CT_FEATURES_NAMELEN) { | |
195 | printk("nf_conntrack_register_cache: name too long\n"); | |
196 | ret = -EINVAL; | |
197 | goto out_free_name; | |
198 | } | |
199 | ||
200 | cachep = kmem_cache_create(cache_name, size, 0, 0, | |
201 | NULL, NULL); | |
202 | if (!cachep) { | |
203 | printk("nf_conntrack_register_cache: Can't create slab cache " | |
204 | "for the features = 0x%x\n", features); | |
205 | ret = -ENOMEM; | |
206 | goto out_free_name; | |
207 | } | |
208 | ||
209 | write_lock_bh(&nf_ct_cache_lock); | |
210 | nf_ct_cache[features].use = 1; | |
211 | nf_ct_cache[features].size = size; | |
9fb9cbb1 YK |
212 | nf_ct_cache[features].cachep = cachep; |
213 | nf_ct_cache[features].name = cache_name; | |
214 | write_unlock_bh(&nf_ct_cache_lock); | |
215 | ||
216 | goto out_up_mutex; | |
217 | ||
218 | out_free_name: | |
219 | kfree(cache_name); | |
220 | out_up_mutex: | |
57b47a53 | 221 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
222 | return ret; |
223 | } | |
13b18339 | 224 | EXPORT_SYMBOL_GPL(nf_conntrack_register_cache); |
9fb9cbb1 YK |
225 | |
226 | /* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */ | |
227 | void nf_conntrack_unregister_cache(u_int32_t features) | |
228 | { | |
229 | kmem_cache_t *cachep; | |
230 | char *name; | |
231 | ||
232 | /* | |
233 | * This assures that kmem_cache_create() isn't called before destroying | |
234 | * slab cache. | |
235 | */ | |
236 | DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features); | |
57b47a53 | 237 | mutex_lock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
238 | |
239 | write_lock_bh(&nf_ct_cache_lock); | |
240 | if (--nf_ct_cache[features].use > 0) { | |
241 | write_unlock_bh(&nf_ct_cache_lock); | |
57b47a53 | 242 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 YK |
243 | return; |
244 | } | |
245 | cachep = nf_ct_cache[features].cachep; | |
246 | name = nf_ct_cache[features].name; | |
247 | nf_ct_cache[features].cachep = NULL; | |
248 | nf_ct_cache[features].name = NULL; | |
9fb9cbb1 YK |
249 | nf_ct_cache[features].size = 0; |
250 | write_unlock_bh(&nf_ct_cache_lock); | |
251 | ||
252 | synchronize_net(); | |
253 | ||
254 | kmem_cache_destroy(cachep); | |
255 | kfree(name); | |
256 | ||
57b47a53 | 257 | mutex_unlock(&nf_ct_cache_mutex); |
9fb9cbb1 | 258 | } |
13b18339 | 259 | EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache); |
9fb9cbb1 YK |
260 | |
261 | int | |
262 | nf_ct_get_tuple(const struct sk_buff *skb, | |
263 | unsigned int nhoff, | |
264 | unsigned int dataoff, | |
265 | u_int16_t l3num, | |
266 | u_int8_t protonum, | |
267 | struct nf_conntrack_tuple *tuple, | |
268 | const struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 269 | const struct nf_conntrack_l4proto *l4proto) |
9fb9cbb1 YK |
270 | { |
271 | NF_CT_TUPLE_U_BLANK(tuple); | |
272 | ||
273 | tuple->src.l3num = l3num; | |
274 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
275 | return 0; | |
276 | ||
277 | tuple->dst.protonum = protonum; | |
278 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
279 | ||
605dcad6 | 280 | return l4proto->pkt_to_tuple(skb, dataoff, tuple); |
9fb9cbb1 | 281 | } |
13b18339 | 282 | EXPORT_SYMBOL_GPL(nf_ct_get_tuple); |
9fb9cbb1 YK |
283 | |
284 | int | |
285 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
286 | const struct nf_conntrack_tuple *orig, | |
287 | const struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 288 | const struct nf_conntrack_l4proto *l4proto) |
9fb9cbb1 YK |
289 | { |
290 | NF_CT_TUPLE_U_BLANK(inverse); | |
291 | ||
292 | inverse->src.l3num = orig->src.l3num; | |
293 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
294 | return 0; | |
295 | ||
296 | inverse->dst.dir = !orig->dst.dir; | |
297 | ||
298 | inverse->dst.protonum = orig->dst.protonum; | |
605dcad6 | 299 | return l4proto->invert_tuple(inverse, orig); |
9fb9cbb1 | 300 | } |
13b18339 | 301 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); |
9fb9cbb1 | 302 | |
9fb9cbb1 YK |
303 | static void |
304 | clean_from_lists(struct nf_conn *ct) | |
305 | { | |
9fb9cbb1 | 306 | DEBUGP("clean_from_lists(%p)\n", ct); |
df0933dc PM |
307 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); |
308 | list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); | |
9fb9cbb1 YK |
309 | |
310 | /* Destroy all pending expectations */ | |
c1d10adb | 311 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
312 | } |
313 | ||
314 | static void | |
315 | destroy_conntrack(struct nf_conntrack *nfct) | |
316 | { | |
317 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
f09943fe | 318 | struct nf_conn_help *help = nfct_help(ct); |
9fb9cbb1 | 319 | struct nf_conntrack_l3proto *l3proto; |
605dcad6 | 320 | struct nf_conntrack_l4proto *l4proto; |
9fb9cbb1 YK |
321 | |
322 | DEBUGP("destroy_conntrack(%p)\n", ct); | |
323 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); | |
324 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
325 | ||
326 | nf_conntrack_event(IPCT_DESTROY, ct); | |
327 | set_bit(IPS_DYING_BIT, &ct->status); | |
328 | ||
f09943fe PM |
329 | if (help && help->helper && help->helper->destroy) |
330 | help->helper->destroy(ct); | |
331 | ||
9fb9cbb1 YK |
332 | /* To make sure we don't get any weird locking issues here: |
333 | * destroy_conntrack() MUST NOT be called with a write lock | |
334 | * to nf_conntrack_lock!!! -HW */ | |
c1d10adb | 335 | l3proto = __nf_ct_l3proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num); |
9fb9cbb1 YK |
336 | if (l3proto && l3proto->destroy) |
337 | l3proto->destroy(ct); | |
338 | ||
605dcad6 MJ |
339 | l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); |
340 | if (l4proto && l4proto->destroy) | |
341 | l4proto->destroy(ct); | |
9fb9cbb1 YK |
342 | |
343 | if (nf_conntrack_destroyed) | |
344 | nf_conntrack_destroyed(ct); | |
345 | ||
346 | write_lock_bh(&nf_conntrack_lock); | |
347 | /* Expectations will have been removed in clean_from_lists, | |
348 | * except TFTP can create an expectation on the first packet, | |
349 | * before connection is in the list, so we need to clean here, | |
350 | * too. */ | |
c1d10adb | 351 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
352 | |
353 | /* We overload first tuple to link into unconfirmed list. */ | |
354 | if (!nf_ct_is_confirmed(ct)) { | |
355 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); | |
356 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
357 | } | |
358 | ||
359 | NF_CT_STAT_INC(delete); | |
360 | write_unlock_bh(&nf_conntrack_lock); | |
361 | ||
362 | if (ct->master) | |
363 | nf_ct_put(ct->master); | |
364 | ||
365 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); | |
366 | nf_conntrack_free(ct); | |
367 | } | |
368 | ||
369 | static void death_by_timeout(unsigned long ul_conntrack) | |
370 | { | |
371 | struct nf_conn *ct = (void *)ul_conntrack; | |
372 | ||
373 | write_lock_bh(&nf_conntrack_lock); | |
374 | /* Inside lock so preempt is disabled on module removal path. | |
375 | * Otherwise we can get spurious warnings. */ | |
376 | NF_CT_STAT_INC(delete_list); | |
377 | clean_from_lists(ct); | |
378 | write_unlock_bh(&nf_conntrack_lock); | |
379 | nf_ct_put(ct); | |
380 | } | |
381 | ||
c1d10adb | 382 | struct nf_conntrack_tuple_hash * |
9fb9cbb1 YK |
383 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
384 | const struct nf_conn *ignored_conntrack) | |
385 | { | |
386 | struct nf_conntrack_tuple_hash *h; | |
387 | unsigned int hash = hash_conntrack(tuple); | |
388 | ||
9fb9cbb1 | 389 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) { |
df0933dc PM |
390 | if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && |
391 | nf_ct_tuple_equal(tuple, &h->tuple)) { | |
9fb9cbb1 YK |
392 | NF_CT_STAT_INC(found); |
393 | return h; | |
394 | } | |
395 | NF_CT_STAT_INC(searched); | |
396 | } | |
397 | ||
398 | return NULL; | |
399 | } | |
13b18339 | 400 | EXPORT_SYMBOL_GPL(__nf_conntrack_find); |
9fb9cbb1 YK |
401 | |
402 | /* Find a connection corresponding to a tuple. */ | |
403 | struct nf_conntrack_tuple_hash * | |
404 | nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple, | |
405 | const struct nf_conn *ignored_conntrack) | |
406 | { | |
407 | struct nf_conntrack_tuple_hash *h; | |
408 | ||
409 | read_lock_bh(&nf_conntrack_lock); | |
410 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
411 | if (h) | |
412 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
413 | read_unlock_bh(&nf_conntrack_lock); | |
414 | ||
415 | return h; | |
416 | } | |
13b18339 | 417 | EXPORT_SYMBOL_GPL(nf_conntrack_find_get); |
9fb9cbb1 | 418 | |
c1d10adb PNA |
419 | static void __nf_conntrack_hash_insert(struct nf_conn *ct, |
420 | unsigned int hash, | |
421 | unsigned int repl_hash) | |
422 | { | |
423 | ct->id = ++nf_conntrack_next_id; | |
df0933dc PM |
424 | list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, |
425 | &nf_conntrack_hash[hash]); | |
426 | list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, | |
427 | &nf_conntrack_hash[repl_hash]); | |
c1d10adb PNA |
428 | } |
429 | ||
430 | void nf_conntrack_hash_insert(struct nf_conn *ct) | |
431 | { | |
432 | unsigned int hash, repl_hash; | |
433 | ||
434 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
435 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
436 | ||
437 | write_lock_bh(&nf_conntrack_lock); | |
438 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
439 | write_unlock_bh(&nf_conntrack_lock); | |
440 | } | |
13b18339 | 441 | EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); |
c1d10adb | 442 | |
9fb9cbb1 YK |
443 | /* Confirm a connection given skb; places it in hash table */ |
444 | int | |
445 | __nf_conntrack_confirm(struct sk_buff **pskb) | |
446 | { | |
447 | unsigned int hash, repl_hash; | |
df0933dc | 448 | struct nf_conntrack_tuple_hash *h; |
9fb9cbb1 | 449 | struct nf_conn *ct; |
df0933dc | 450 | struct nf_conn_help *help; |
9fb9cbb1 YK |
451 | enum ip_conntrack_info ctinfo; |
452 | ||
453 | ct = nf_ct_get(*pskb, &ctinfo); | |
454 | ||
455 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
456 | ICMP/TCP RST packets in other direction. Actual packet | |
457 | which created connection will be IP_CT_NEW or for an | |
458 | expected connection, IP_CT_RELATED. */ | |
459 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
460 | return NF_ACCEPT; | |
461 | ||
462 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
463 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
464 | ||
465 | /* We're not in hash table, and we refuse to set up related | |
466 | connections for unconfirmed conns. But packet copies and | |
467 | REJECT will give spurious warnings here. */ | |
468 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
469 | ||
470 | /* No external references means noone else could have | |
471 | confirmed us. */ | |
472 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
473 | DEBUGP("Confirming conntrack %p\n", ct); | |
474 | ||
475 | write_lock_bh(&nf_conntrack_lock); | |
476 | ||
477 | /* See if there's one in the list already, including reverse: | |
478 | NAT could have grabbed it without realizing, since we're | |
479 | not in the hash. If there is, we lost race. */ | |
df0933dc PM |
480 | list_for_each_entry(h, &nf_conntrack_hash[hash], list) |
481 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, | |
482 | &h->tuple)) | |
483 | goto out; | |
484 | list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list) | |
485 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, | |
486 | &h->tuple)) | |
487 | goto out; | |
9fb9cbb1 | 488 | |
df0933dc PM |
489 | /* Remove from unconfirmed list */ |
490 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
491 | ||
492 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
493 | /* Timer relative to confirmation time, not original | |
494 | setting time, otherwise we'd get timer wrap in | |
495 | weird delay cases. */ | |
496 | ct->timeout.expires += jiffies; | |
497 | add_timer(&ct->timeout); | |
498 | atomic_inc(&ct->ct_general.use); | |
499 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
500 | NF_CT_STAT_INC(insert); | |
501 | write_unlock_bh(&nf_conntrack_lock); | |
502 | help = nfct_help(ct); | |
503 | if (help && help->helper) | |
504 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); | |
9fb9cbb1 | 505 | #ifdef CONFIG_NF_NAT_NEEDED |
df0933dc PM |
506 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || |
507 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
508 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
9fb9cbb1 | 509 | #endif |
df0933dc PM |
510 | nf_conntrack_event_cache(master_ct(ct) ? |
511 | IPCT_RELATED : IPCT_NEW, *pskb); | |
512 | return NF_ACCEPT; | |
9fb9cbb1 | 513 | |
df0933dc | 514 | out: |
9fb9cbb1 YK |
515 | NF_CT_STAT_INC(insert_failed); |
516 | write_unlock_bh(&nf_conntrack_lock); | |
517 | return NF_DROP; | |
518 | } | |
13b18339 | 519 | EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); |
9fb9cbb1 YK |
520 | |
521 | /* Returns true if a connection correspondings to the tuple (required | |
522 | for NAT). */ | |
523 | int | |
524 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
525 | const struct nf_conn *ignored_conntrack) | |
526 | { | |
527 | struct nf_conntrack_tuple_hash *h; | |
528 | ||
529 | read_lock_bh(&nf_conntrack_lock); | |
530 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
531 | read_unlock_bh(&nf_conntrack_lock); | |
532 | ||
533 | return h != NULL; | |
534 | } | |
13b18339 | 535 | EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); |
9fb9cbb1 YK |
536 | |
537 | /* There's a small race here where we may free a just-assured | |
538 | connection. Too bad: we're in trouble anyway. */ | |
9fb9cbb1 YK |
539 | static int early_drop(struct list_head *chain) |
540 | { | |
541 | /* Traverse backwards: gives us oldest, which is roughly LRU */ | |
542 | struct nf_conntrack_tuple_hash *h; | |
df0933dc | 543 | struct nf_conn *ct = NULL, *tmp; |
9fb9cbb1 YK |
544 | int dropped = 0; |
545 | ||
546 | read_lock_bh(&nf_conntrack_lock); | |
df0933dc PM |
547 | list_for_each_entry_reverse(h, chain, list) { |
548 | tmp = nf_ct_tuplehash_to_ctrack(h); | |
549 | if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { | |
550 | ct = tmp; | |
551 | atomic_inc(&ct->ct_general.use); | |
552 | break; | |
553 | } | |
9fb9cbb1 YK |
554 | } |
555 | read_unlock_bh(&nf_conntrack_lock); | |
556 | ||
557 | if (!ct) | |
558 | return dropped; | |
559 | ||
560 | if (del_timer(&ct->timeout)) { | |
561 | death_by_timeout((unsigned long)ct); | |
562 | dropped = 1; | |
563 | NF_CT_STAT_INC(early_drop); | |
564 | } | |
565 | nf_ct_put(ct); | |
566 | return dropped; | |
567 | } | |
568 | ||
9fb9cbb1 YK |
569 | static struct nf_conn * |
570 | __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
571 | const struct nf_conntrack_tuple *repl, | |
9457d851 PM |
572 | const struct nf_conntrack_l3proto *l3proto, |
573 | u_int32_t features) | |
9fb9cbb1 YK |
574 | { |
575 | struct nf_conn *conntrack = NULL; | |
dc808fe2 | 576 | struct nf_conntrack_helper *helper; |
9fb9cbb1 | 577 | |
dc808fe2 | 578 | if (unlikely(!nf_conntrack_hash_rnd_initted)) { |
9fb9cbb1 YK |
579 | get_random_bytes(&nf_conntrack_hash_rnd, 4); |
580 | nf_conntrack_hash_rnd_initted = 1; | |
581 | } | |
582 | ||
5251e2d2 PNA |
583 | /* We don't want any race condition at early drop stage */ |
584 | atomic_inc(&nf_conntrack_count); | |
585 | ||
9fb9cbb1 | 586 | if (nf_conntrack_max |
5251e2d2 | 587 | && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { |
9fb9cbb1 YK |
588 | unsigned int hash = hash_conntrack(orig); |
589 | /* Try dropping from this hash chain. */ | |
590 | if (!early_drop(&nf_conntrack_hash[hash])) { | |
5251e2d2 | 591 | atomic_dec(&nf_conntrack_count); |
9fb9cbb1 YK |
592 | if (net_ratelimit()) |
593 | printk(KERN_WARNING | |
594 | "nf_conntrack: table full, dropping" | |
595 | " packet.\n"); | |
596 | return ERR_PTR(-ENOMEM); | |
597 | } | |
598 | } | |
599 | ||
600 | /* find features needed by this conntrack. */ | |
9457d851 | 601 | features |= l3proto->get_features(orig); |
dc808fe2 HW |
602 | |
603 | /* FIXME: protect helper list per RCU */ | |
9fb9cbb1 | 604 | read_lock_bh(&nf_conntrack_lock); |
dc808fe2 | 605 | helper = __nf_ct_helper_find(repl); |
5b1158e9 JK |
606 | /* NAT might want to assign a helper later */ |
607 | if (helper || features & NF_CT_F_NAT) | |
9fb9cbb1 YK |
608 | features |= NF_CT_F_HELP; |
609 | read_unlock_bh(&nf_conntrack_lock); | |
610 | ||
611 | DEBUGP("nf_conntrack_alloc: features=0x%x\n", features); | |
612 | ||
613 | read_lock_bh(&nf_ct_cache_lock); | |
614 | ||
dc808fe2 | 615 | if (unlikely(!nf_ct_cache[features].use)) { |
9fb9cbb1 YK |
616 | DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n", |
617 | features); | |
618 | goto out; | |
619 | } | |
620 | ||
621 | conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC); | |
622 | if (conntrack == NULL) { | |
623 | DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n"); | |
624 | goto out; | |
625 | } | |
626 | ||
627 | memset(conntrack, 0, nf_ct_cache[features].size); | |
628 | conntrack->features = features; | |
9fb9cbb1 YK |
629 | atomic_set(&conntrack->ct_general.use, 1); |
630 | conntrack->ct_general.destroy = destroy_conntrack; | |
631 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; | |
632 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
633 | /* Don't set timer yet: wait for confirmation */ | |
634 | init_timer(&conntrack->timeout); | |
635 | conntrack->timeout.data = (unsigned long)conntrack; | |
636 | conntrack->timeout.function = death_by_timeout; | |
5251e2d2 | 637 | read_unlock_bh(&nf_ct_cache_lock); |
9fb9cbb1 | 638 | |
5251e2d2 | 639 | return conntrack; |
9fb9cbb1 YK |
640 | out: |
641 | read_unlock_bh(&nf_ct_cache_lock); | |
5251e2d2 | 642 | atomic_dec(&nf_conntrack_count); |
9fb9cbb1 YK |
643 | return conntrack; |
644 | } | |
645 | ||
646 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, | |
647 | const struct nf_conntrack_tuple *repl) | |
648 | { | |
649 | struct nf_conntrack_l3proto *l3proto; | |
650 | ||
c1d10adb | 651 | l3proto = __nf_ct_l3proto_find(orig->src.l3num); |
9457d851 | 652 | return __nf_conntrack_alloc(orig, repl, l3proto, 0); |
9fb9cbb1 | 653 | } |
13b18339 | 654 | EXPORT_SYMBOL_GPL(nf_conntrack_alloc); |
9fb9cbb1 YK |
655 | |
656 | void nf_conntrack_free(struct nf_conn *conntrack) | |
657 | { | |
658 | u_int32_t features = conntrack->features; | |
659 | NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM); | |
660 | DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features, | |
661 | conntrack); | |
662 | kmem_cache_free(nf_ct_cache[features].cachep, conntrack); | |
663 | atomic_dec(&nf_conntrack_count); | |
664 | } | |
13b18339 | 665 | EXPORT_SYMBOL_GPL(nf_conntrack_free); |
9fb9cbb1 YK |
666 | |
667 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
668 | failed due to stress. Otherwise it really is unclassifiable. */ | |
669 | static struct nf_conntrack_tuple_hash * | |
670 | init_conntrack(const struct nf_conntrack_tuple *tuple, | |
671 | struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 672 | struct nf_conntrack_l4proto *l4proto, |
9fb9cbb1 YK |
673 | struct sk_buff *skb, |
674 | unsigned int dataoff) | |
675 | { | |
676 | struct nf_conn *conntrack; | |
677 | struct nf_conntrack_tuple repl_tuple; | |
678 | struct nf_conntrack_expect *exp; | |
9457d851 | 679 | u_int32_t features = 0; |
9fb9cbb1 | 680 | |
605dcad6 | 681 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { |
9fb9cbb1 YK |
682 | DEBUGP("Can't invert tuple.\n"); |
683 | return NULL; | |
684 | } | |
685 | ||
9457d851 PM |
686 | read_lock_bh(&nf_conntrack_lock); |
687 | exp = __nf_conntrack_expect_find(tuple); | |
688 | if (exp && exp->helper) | |
689 | features = NF_CT_F_HELP; | |
690 | read_unlock_bh(&nf_conntrack_lock); | |
691 | ||
692 | conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features); | |
9fb9cbb1 YK |
693 | if (conntrack == NULL || IS_ERR(conntrack)) { |
694 | DEBUGP("Can't allocate conntrack.\n"); | |
695 | return (struct nf_conntrack_tuple_hash *)conntrack; | |
696 | } | |
697 | ||
605dcad6 | 698 | if (!l4proto->new(conntrack, skb, dataoff)) { |
9fb9cbb1 YK |
699 | nf_conntrack_free(conntrack); |
700 | DEBUGP("init conntrack: can't track with proto module\n"); | |
701 | return NULL; | |
702 | } | |
703 | ||
704 | write_lock_bh(&nf_conntrack_lock); | |
705 | exp = find_expectation(tuple); | |
706 | ||
707 | if (exp) { | |
708 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", | |
709 | conntrack, exp); | |
710 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
711 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
712 | conntrack->master = exp->master; | |
9457d851 PM |
713 | if (exp->helper) |
714 | nfct_help(conntrack)->helper = exp->helper; | |
9fb9cbb1 YK |
715 | #ifdef CONFIG_NF_CONNTRACK_MARK |
716 | conntrack->mark = exp->master->mark; | |
7c9728c3 JM |
717 | #endif |
718 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
719 | conntrack->secmark = exp->master->secmark; | |
9fb9cbb1 YK |
720 | #endif |
721 | nf_conntrack_get(&conntrack->master->ct_general); | |
722 | NF_CT_STAT_INC(expect_new); | |
22e7410b YK |
723 | } else { |
724 | struct nf_conn_help *help = nfct_help(conntrack); | |
725 | ||
726 | if (help) | |
727 | help->helper = __nf_ct_helper_find(&repl_tuple); | |
9fb9cbb1 | 728 | NF_CT_STAT_INC(new); |
22e7410b | 729 | } |
9fb9cbb1 YK |
730 | |
731 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
732 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); | |
733 | ||
734 | write_unlock_bh(&nf_conntrack_lock); | |
735 | ||
736 | if (exp) { | |
737 | if (exp->expectfn) | |
738 | exp->expectfn(conntrack, exp); | |
739 | nf_conntrack_expect_put(exp); | |
740 | } | |
741 | ||
742 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
743 | } | |
744 | ||
745 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
746 | static inline struct nf_conn * | |
747 | resolve_normal_ct(struct sk_buff *skb, | |
748 | unsigned int dataoff, | |
749 | u_int16_t l3num, | |
750 | u_int8_t protonum, | |
751 | struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 752 | struct nf_conntrack_l4proto *l4proto, |
9fb9cbb1 YK |
753 | int *set_reply, |
754 | enum ip_conntrack_info *ctinfo) | |
755 | { | |
756 | struct nf_conntrack_tuple tuple; | |
757 | struct nf_conntrack_tuple_hash *h; | |
758 | struct nf_conn *ct; | |
759 | ||
760 | if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data), | |
761 | dataoff, l3num, protonum, &tuple, l3proto, | |
605dcad6 | 762 | l4proto)) { |
9fb9cbb1 YK |
763 | DEBUGP("resolve_normal_ct: Can't get tuple\n"); |
764 | return NULL; | |
765 | } | |
766 | ||
767 | /* look for tuple match */ | |
768 | h = nf_conntrack_find_get(&tuple, NULL); | |
769 | if (!h) { | |
605dcad6 | 770 | h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff); |
9fb9cbb1 YK |
771 | if (!h) |
772 | return NULL; | |
773 | if (IS_ERR(h)) | |
774 | return (void *)h; | |
775 | } | |
776 | ct = nf_ct_tuplehash_to_ctrack(h); | |
777 | ||
778 | /* It exists; we have (non-exclusive) reference. */ | |
779 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
780 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
781 | /* Please set reply bit if this packet OK */ | |
782 | *set_reply = 1; | |
783 | } else { | |
784 | /* Once we've had two way comms, always ESTABLISHED. */ | |
785 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
786 | DEBUGP("nf_conntrack_in: normal packet for %p\n", ct); | |
787 | *ctinfo = IP_CT_ESTABLISHED; | |
788 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
789 | DEBUGP("nf_conntrack_in: related packet for %p\n", ct); | |
790 | *ctinfo = IP_CT_RELATED; | |
791 | } else { | |
792 | DEBUGP("nf_conntrack_in: new packet for %p\n", ct); | |
793 | *ctinfo = IP_CT_NEW; | |
794 | } | |
795 | *set_reply = 0; | |
796 | } | |
797 | skb->nfct = &ct->ct_general; | |
798 | skb->nfctinfo = *ctinfo; | |
799 | return ct; | |
800 | } | |
801 | ||
802 | unsigned int | |
803 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) | |
804 | { | |
805 | struct nf_conn *ct; | |
806 | enum ip_conntrack_info ctinfo; | |
807 | struct nf_conntrack_l3proto *l3proto; | |
605dcad6 | 808 | struct nf_conntrack_l4proto *l4proto; |
9fb9cbb1 YK |
809 | unsigned int dataoff; |
810 | u_int8_t protonum; | |
811 | int set_reply = 0; | |
812 | int ret; | |
813 | ||
814 | /* Previously seen (loopback or untracked)? Ignore. */ | |
815 | if ((*pskb)->nfct) { | |
816 | NF_CT_STAT_INC(ignore); | |
817 | return NF_ACCEPT; | |
818 | } | |
819 | ||
c1d10adb | 820 | l3proto = __nf_ct_l3proto_find((u_int16_t)pf); |
9fb9cbb1 YK |
821 | if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) { |
822 | DEBUGP("not prepared to track yet or error occured\n"); | |
823 | return -ret; | |
824 | } | |
825 | ||
605dcad6 | 826 | l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum); |
9fb9cbb1 YK |
827 | |
828 | /* It may be an special packet, error, unclean... | |
829 | * inverse of the return code tells to the netfilter | |
830 | * core what to do with the packet. */ | |
605dcad6 MJ |
831 | if (l4proto->error != NULL && |
832 | (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { | |
9fb9cbb1 YK |
833 | NF_CT_STAT_INC(error); |
834 | NF_CT_STAT_INC(invalid); | |
835 | return -ret; | |
836 | } | |
837 | ||
605dcad6 | 838 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto, |
9fb9cbb1 YK |
839 | &set_reply, &ctinfo); |
840 | if (!ct) { | |
841 | /* Not valid part of a connection */ | |
842 | NF_CT_STAT_INC(invalid); | |
843 | return NF_ACCEPT; | |
844 | } | |
845 | ||
846 | if (IS_ERR(ct)) { | |
847 | /* Too stressed to deal. */ | |
848 | NF_CT_STAT_INC(drop); | |
849 | return NF_DROP; | |
850 | } | |
851 | ||
852 | NF_CT_ASSERT((*pskb)->nfct); | |
853 | ||
605dcad6 | 854 | ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); |
9fb9cbb1 YK |
855 | if (ret < 0) { |
856 | /* Invalid: inverse of the return code tells | |
857 | * the netfilter core what to do */ | |
858 | DEBUGP("nf_conntrack_in: Can't track with proto module\n"); | |
859 | nf_conntrack_put((*pskb)->nfct); | |
860 | (*pskb)->nfct = NULL; | |
861 | NF_CT_STAT_INC(invalid); | |
862 | return -ret; | |
863 | } | |
864 | ||
865 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
866 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); | |
867 | ||
868 | return ret; | |
869 | } | |
13b18339 | 870 | EXPORT_SYMBOL_GPL(nf_conntrack_in); |
9fb9cbb1 YK |
871 | |
872 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
873 | const struct nf_conntrack_tuple *orig) | |
874 | { | |
875 | return nf_ct_invert_tuple(inverse, orig, | |
c1d10adb | 876 | __nf_ct_l3proto_find(orig->src.l3num), |
605dcad6 | 877 | __nf_ct_l4proto_find(orig->src.l3num, |
c1d10adb | 878 | orig->dst.protonum)); |
9fb9cbb1 | 879 | } |
13b18339 | 880 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); |
9fb9cbb1 | 881 | |
5b1158e9 JK |
882 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is |
883 | implicitly racy: see __nf_conntrack_confirm */ | |
884 | void nf_conntrack_alter_reply(struct nf_conn *ct, | |
885 | const struct nf_conntrack_tuple *newreply) | |
886 | { | |
887 | struct nf_conn_help *help = nfct_help(ct); | |
888 | ||
889 | write_lock_bh(&nf_conntrack_lock); | |
890 | /* Should be unconfirmed, so not in hash table yet */ | |
891 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
892 | ||
893 | DEBUGP("Altering reply tuple of %p to ", ct); | |
894 | NF_CT_DUMP_TUPLE(newreply); | |
895 | ||
896 | ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; | |
897 | if (!ct->master && help && help->expecting == 0) | |
898 | help->helper = __nf_ct_helper_find(newreply); | |
899 | write_unlock_bh(&nf_conntrack_lock); | |
900 | } | |
13b18339 | 901 | EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); |
5b1158e9 | 902 | |
9fb9cbb1 YK |
903 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ |
904 | void __nf_ct_refresh_acct(struct nf_conn *ct, | |
905 | enum ip_conntrack_info ctinfo, | |
906 | const struct sk_buff *skb, | |
907 | unsigned long extra_jiffies, | |
908 | int do_acct) | |
909 | { | |
910 | int event = 0; | |
911 | ||
912 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); | |
913 | NF_CT_ASSERT(skb); | |
914 | ||
915 | write_lock_bh(&nf_conntrack_lock); | |
916 | ||
997ae831 EL |
917 | /* Only update if this is not a fixed timeout */ |
918 | if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { | |
919 | write_unlock_bh(&nf_conntrack_lock); | |
920 | return; | |
921 | } | |
922 | ||
9fb9cbb1 YK |
923 | /* If not in hash table, timer will not be active yet */ |
924 | if (!nf_ct_is_confirmed(ct)) { | |
925 | ct->timeout.expires = extra_jiffies; | |
926 | event = IPCT_REFRESH; | |
927 | } else { | |
be00c8e4 MJ |
928 | unsigned long newtime = jiffies + extra_jiffies; |
929 | ||
930 | /* Only update the timeout if the new timeout is at least | |
931 | HZ jiffies from the old timeout. Need del_timer for race | |
932 | avoidance (may already be dying). */ | |
933 | if (newtime - ct->timeout.expires >= HZ | |
934 | && del_timer(&ct->timeout)) { | |
935 | ct->timeout.expires = newtime; | |
9fb9cbb1 YK |
936 | add_timer(&ct->timeout); |
937 | event = IPCT_REFRESH; | |
938 | } | |
939 | } | |
940 | ||
941 | #ifdef CONFIG_NF_CT_ACCT | |
942 | if (do_acct) { | |
943 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
944 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
945 | skb->len - (unsigned int)(skb->nh.raw - skb->data); | |
3ffd5eeb MJ |
946 | |
947 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) | |
948 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
949 | event |= IPCT_COUNTER_FILLING; | |
9fb9cbb1 YK |
950 | } |
951 | #endif | |
952 | ||
953 | write_unlock_bh(&nf_conntrack_lock); | |
954 | ||
955 | /* must be unlocked when calling event cache */ | |
956 | if (event) | |
957 | nf_conntrack_event_cache(event, skb); | |
958 | } | |
13b18339 | 959 | EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); |
9fb9cbb1 | 960 | |
c1d10adb PNA |
961 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
962 | defined(CONFIG_NF_CT_NETLINK_MODULE) | |
963 | ||
964 | #include <linux/netfilter/nfnetlink.h> | |
965 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
57b47a53 IM |
966 | #include <linux/mutex.h> |
967 | ||
c1d10adb PNA |
968 | |
969 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
970 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
971 | * or depend on ctnetlink */ | |
972 | int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
973 | const struct nf_conntrack_tuple *tuple) | |
974 | { | |
975 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), | |
976 | &tuple->src.u.tcp.port); | |
977 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), | |
978 | &tuple->dst.u.tcp.port); | |
979 | return 0; | |
980 | ||
981 | nfattr_failure: | |
982 | return -1; | |
983 | } | |
13b18339 | 984 | EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr); |
c1d10adb PNA |
985 | |
986 | static const size_t cta_min_proto[CTA_PROTO_MAX] = { | |
987 | [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), | |
988 | [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) | |
989 | }; | |
990 | ||
991 | int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
992 | struct nf_conntrack_tuple *t) | |
993 | { | |
994 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
995 | return -EINVAL; | |
996 | ||
997 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
998 | return -EINVAL; | |
999 | ||
bff9a89b PM |
1000 | t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); |
1001 | t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); | |
c1d10adb PNA |
1002 | |
1003 | return 0; | |
1004 | } | |
13b18339 | 1005 | EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple); |
c1d10adb PNA |
1006 | #endif |
1007 | ||
9fb9cbb1 YK |
1008 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
1009 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1010 | { | |
1011 | struct nf_conn *ct; | |
1012 | enum ip_conntrack_info ctinfo; | |
1013 | ||
1014 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1015 | ct = nf_ct_get(skb, &ctinfo); | |
1016 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1017 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
1018 | else | |
1019 | ctinfo = IP_CT_RELATED; | |
1020 | ||
1021 | /* Attach to new skbuff, and increment count */ | |
1022 | nskb->nfct = &ct->ct_general; | |
1023 | nskb->nfctinfo = ctinfo; | |
1024 | nf_conntrack_get(nskb->nfct); | |
1025 | } | |
13b18339 | 1026 | EXPORT_SYMBOL_GPL(__nf_conntrack_attach); |
9fb9cbb1 YK |
1027 | |
1028 | static inline int | |
1029 | do_iter(const struct nf_conntrack_tuple_hash *i, | |
1030 | int (*iter)(struct nf_conn *i, void *data), | |
1031 | void *data) | |
1032 | { | |
1033 | return iter(nf_ct_tuplehash_to_ctrack(i), data); | |
1034 | } | |
1035 | ||
1036 | /* Bring out ya dead! */ | |
df0933dc | 1037 | static struct nf_conn * |
9fb9cbb1 YK |
1038 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), |
1039 | void *data, unsigned int *bucket) | |
1040 | { | |
df0933dc PM |
1041 | struct nf_conntrack_tuple_hash *h; |
1042 | struct nf_conn *ct; | |
9fb9cbb1 YK |
1043 | |
1044 | write_lock_bh(&nf_conntrack_lock); | |
1045 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { | |
df0933dc PM |
1046 | list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) { |
1047 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1048 | if (iter(ct, data)) | |
1049 | goto found; | |
1050 | } | |
9fb9cbb1 | 1051 | } |
df0933dc PM |
1052 | list_for_each_entry(h, &unconfirmed, list) { |
1053 | ct = nf_ct_tuplehash_to_ctrack(h); | |
1054 | if (iter(ct, data)) | |
1055 | goto found; | |
1056 | } | |
c073e3fa | 1057 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc PM |
1058 | return NULL; |
1059 | found: | |
c073e3fa | 1060 | atomic_inc(&ct->ct_general.use); |
9fb9cbb1 | 1061 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc | 1062 | return ct; |
9fb9cbb1 YK |
1063 | } |
1064 | ||
1065 | void | |
1066 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) | |
1067 | { | |
df0933dc | 1068 | struct nf_conn *ct; |
9fb9cbb1 YK |
1069 | unsigned int bucket = 0; |
1070 | ||
df0933dc | 1071 | while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { |
9fb9cbb1 YK |
1072 | /* Time to push up daises... */ |
1073 | if (del_timer(&ct->timeout)) | |
1074 | death_by_timeout((unsigned long)ct); | |
1075 | /* ... else the timer will get him soon. */ | |
1076 | ||
1077 | nf_ct_put(ct); | |
1078 | } | |
1079 | } | |
13b18339 | 1080 | EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); |
9fb9cbb1 YK |
1081 | |
1082 | static int kill_all(struct nf_conn *i, void *data) | |
1083 | { | |
1084 | return 1; | |
1085 | } | |
1086 | ||
1087 | static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size) | |
1088 | { | |
1089 | if (vmalloced) | |
1090 | vfree(hash); | |
1091 | else | |
1092 | free_pages((unsigned long)hash, | |
1093 | get_order(sizeof(struct list_head) * size)); | |
1094 | } | |
1095 | ||
c1d10adb PNA |
1096 | void nf_conntrack_flush() |
1097 | { | |
1098 | nf_ct_iterate_cleanup(kill_all, NULL); | |
1099 | } | |
13b18339 | 1100 | EXPORT_SYMBOL_GPL(nf_conntrack_flush); |
c1d10adb | 1101 | |
9fb9cbb1 YK |
1102 | /* Mishearing the voices in his head, our hero wonders how he's |
1103 | supposed to kill the mall. */ | |
1104 | void nf_conntrack_cleanup(void) | |
1105 | { | |
1106 | int i; | |
1107 | ||
7d3cdc6b YK |
1108 | ip_ct_attach = NULL; |
1109 | ||
9fb9cbb1 YK |
1110 | /* This makes sure all current packets have passed through |
1111 | netfilter framework. Roll on, two-stage module | |
1112 | delete... */ | |
1113 | synchronize_net(); | |
1114 | ||
1115 | nf_ct_event_cache_flush(); | |
1116 | i_see_dead_people: | |
c1d10adb | 1117 | nf_conntrack_flush(); |
9fb9cbb1 YK |
1118 | if (atomic_read(&nf_conntrack_count) != 0) { |
1119 | schedule(); | |
1120 | goto i_see_dead_people; | |
1121 | } | |
6636568c PM |
1122 | /* wait until all references to nf_conntrack_untracked are dropped */ |
1123 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) | |
1124 | schedule(); | |
9fb9cbb1 YK |
1125 | |
1126 | for (i = 0; i < NF_CT_F_NUM; i++) { | |
1127 | if (nf_ct_cache[i].use == 0) | |
1128 | continue; | |
1129 | ||
1130 | NF_CT_ASSERT(nf_ct_cache[i].use == 1); | |
1131 | nf_ct_cache[i].use = 1; | |
1132 | nf_conntrack_unregister_cache(i); | |
1133 | } | |
1134 | kmem_cache_destroy(nf_conntrack_expect_cachep); | |
1135 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1136 | nf_conntrack_htable_size); | |
5a6f294e | 1137 | |
933a41e7 PM |
1138 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_generic); |
1139 | ||
5a6f294e KK |
1140 | /* free l3proto protocol tables */ |
1141 | for (i = 0; i < PF_MAX; i++) | |
1142 | if (nf_ct_protos[i]) { | |
1143 | kfree(nf_ct_protos[i]); | |
1144 | nf_ct_protos[i] = NULL; | |
1145 | } | |
9fb9cbb1 YK |
1146 | } |
1147 | ||
1148 | static struct list_head *alloc_hashtable(int size, int *vmalloced) | |
1149 | { | |
1150 | struct list_head *hash; | |
1151 | unsigned int i; | |
1152 | ||
1153 | *vmalloced = 0; | |
1154 | hash = (void*)__get_free_pages(GFP_KERNEL, | |
1155 | get_order(sizeof(struct list_head) | |
1156 | * size)); | |
1157 | if (!hash) { | |
1158 | *vmalloced = 1; | |
1159 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
1160 | hash = vmalloc(sizeof(struct list_head) * size); | |
1161 | } | |
1162 | ||
1163 | if (hash) | |
1164 | for (i = 0; i < size; i++) | |
1165 | INIT_LIST_HEAD(&hash[i]); | |
1166 | ||
1167 | return hash; | |
1168 | } | |
1169 | ||
1170 | int set_hashsize(const char *val, struct kernel_param *kp) | |
1171 | { | |
1172 | int i, bucket, hashsize, vmalloced; | |
1173 | int old_vmalloced, old_size; | |
1174 | int rnd; | |
1175 | struct list_head *hash, *old_hash; | |
1176 | struct nf_conntrack_tuple_hash *h; | |
1177 | ||
1178 | /* On boot, we can set this without any fancy locking. */ | |
1179 | if (!nf_conntrack_htable_size) | |
1180 | return param_set_uint(val, kp); | |
1181 | ||
1182 | hashsize = simple_strtol(val, NULL, 0); | |
1183 | if (!hashsize) | |
1184 | return -EINVAL; | |
1185 | ||
1186 | hash = alloc_hashtable(hashsize, &vmalloced); | |
1187 | if (!hash) | |
1188 | return -ENOMEM; | |
1189 | ||
1190 | /* We have to rehahs for the new table anyway, so we also can | |
1191 | * use a newrandom seed */ | |
1192 | get_random_bytes(&rnd, 4); | |
1193 | ||
1194 | write_lock_bh(&nf_conntrack_lock); | |
1195 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
1196 | while (!list_empty(&nf_conntrack_hash[i])) { | |
1197 | h = list_entry(nf_conntrack_hash[i].next, | |
1198 | struct nf_conntrack_tuple_hash, list); | |
1199 | list_del(&h->list); | |
1200 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); | |
1201 | list_add_tail(&h->list, &hash[bucket]); | |
1202 | } | |
1203 | } | |
1204 | old_size = nf_conntrack_htable_size; | |
1205 | old_vmalloced = nf_conntrack_vmalloc; | |
1206 | old_hash = nf_conntrack_hash; | |
1207 | ||
1208 | nf_conntrack_htable_size = hashsize; | |
1209 | nf_conntrack_vmalloc = vmalloced; | |
1210 | nf_conntrack_hash = hash; | |
1211 | nf_conntrack_hash_rnd = rnd; | |
1212 | write_unlock_bh(&nf_conntrack_lock); | |
1213 | ||
1214 | free_conntrack_hash(old_hash, old_vmalloced, old_size); | |
1215 | return 0; | |
1216 | } | |
1217 | ||
1218 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1219 | &nf_conntrack_htable_size, 0600); | |
1220 | ||
1221 | int __init nf_conntrack_init(void) | |
1222 | { | |
1223 | unsigned int i; | |
1224 | int ret; | |
1225 | ||
1226 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1227 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ | |
1228 | if (!nf_conntrack_htable_size) { | |
1229 | nf_conntrack_htable_size | |
1230 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
1231 | / sizeof(struct list_head)); | |
1232 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1233 | nf_conntrack_htable_size = 8192; | |
1234 | if (nf_conntrack_htable_size < 16) | |
1235 | nf_conntrack_htable_size = 16; | |
1236 | } | |
1237 | nf_conntrack_max = 8 * nf_conntrack_htable_size; | |
1238 | ||
1239 | printk("nf_conntrack version %s (%u buckets, %d max)\n", | |
1240 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1241 | nf_conntrack_max); | |
1242 | ||
1243 | nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size, | |
1244 | &nf_conntrack_vmalloc); | |
1245 | if (!nf_conntrack_hash) { | |
1246 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1247 | goto err_out; | |
1248 | } | |
1249 | ||
1250 | ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic", | |
dc808fe2 | 1251 | sizeof(struct nf_conn)); |
9fb9cbb1 YK |
1252 | if (ret < 0) { |
1253 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); | |
1254 | goto err_free_hash; | |
1255 | } | |
1256 | ||
1257 | nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect", | |
1258 | sizeof(struct nf_conntrack_expect), | |
1259 | 0, 0, NULL, NULL); | |
1260 | if (!nf_conntrack_expect_cachep) { | |
1261 | printk(KERN_ERR "Unable to create nf_expect slab cache\n"); | |
1262 | goto err_free_conntrack_slab; | |
1263 | } | |
1264 | ||
933a41e7 PM |
1265 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_generic); |
1266 | if (ret < 0) | |
1267 | goto out_free_expect_slab; | |
1268 | ||
9fb9cbb1 YK |
1269 | /* Don't NEED lock here, but good form anyway. */ |
1270 | write_lock_bh(&nf_conntrack_lock); | |
ae5718fb | 1271 | for (i = 0; i < AF_MAX; i++) |
605dcad6 | 1272 | nf_ct_l3protos[i] = &nf_conntrack_l3proto_generic; |
9fb9cbb1 YK |
1273 | write_unlock_bh(&nf_conntrack_lock); |
1274 | ||
7d3cdc6b YK |
1275 | /* For use by REJECT target */ |
1276 | ip_ct_attach = __nf_conntrack_attach; | |
1277 | ||
9fb9cbb1 YK |
1278 | /* Set up fake conntrack: |
1279 | - to never be deleted, not in any hashes */ | |
1280 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); | |
1281 | /* - and look it like as a confirmed connection */ | |
1282 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); | |
1283 | ||
1284 | return ret; | |
1285 | ||
933a41e7 PM |
1286 | out_free_expect_slab: |
1287 | kmem_cache_destroy(nf_conntrack_expect_cachep); | |
9fb9cbb1 YK |
1288 | err_free_conntrack_slab: |
1289 | nf_conntrack_unregister_cache(NF_CT_F_BASIC); | |
1290 | err_free_hash: | |
1291 | free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc, | |
1292 | nf_conntrack_htable_size); | |
1293 | err_out: | |
1294 | return -ENOMEM; | |
1295 | } |