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