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Commit | Line | Data |
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1da177e4 LT |
1 | /* Connection state tracking for netfilter. This is separated from, |
2 | but required by, the NAT layer; it can also be used by an iptables | |
3 | extension. */ | |
4 | ||
5 | /* (C) 1999-2001 Paul `Rusty' Russell | |
6 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * 23 Apr 2001: Harald Welte <laforge@gnumonks.org> | |
13 | * - new API and handling of conntrack/nat helpers | |
14 | * - now capable of multiple expectations for one master | |
15 | * 16 Jul 2002: Harald Welte <laforge@gnumonks.org> | |
16 | * - add usage/reference counts to ip_conntrack_expect | |
17 | * - export ip_conntrack[_expect]_{find_get,put} functions | |
18 | * */ | |
19 | ||
1da177e4 LT |
20 | #include <linux/types.h> |
21 | #include <linux/icmp.h> | |
22 | #include <linux/ip.h> | |
23 | #include <linux/netfilter.h> | |
24 | #include <linux/netfilter_ipv4.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/skbuff.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/vmalloc.h> | |
29 | #include <net/checksum.h> | |
30 | #include <net/ip.h> | |
31 | #include <linux/stddef.h> | |
32 | #include <linux/sysctl.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/random.h> | |
35 | #include <linux/jhash.h> | |
36 | #include <linux/err.h> | |
37 | #include <linux/percpu.h> | |
38 | #include <linux/moduleparam.h> | |
ac3247ba | 39 | #include <linux/notifier.h> |
1da177e4 | 40 | |
e45b1be8 | 41 | /* ip_conntrack_lock protects the main hash table, protocol/helper/expected |
1da177e4 | 42 | registrations, conntrack timers*/ |
1da177e4 LT |
43 | #include <linux/netfilter_ipv4/ip_conntrack.h> |
44 | #include <linux/netfilter_ipv4/ip_conntrack_protocol.h> | |
45 | #include <linux/netfilter_ipv4/ip_conntrack_helper.h> | |
46 | #include <linux/netfilter_ipv4/ip_conntrack_core.h> | |
1da177e4 | 47 | |
eed75f19 | 48 | #define IP_CONNTRACK_VERSION "2.4" |
1da177e4 LT |
49 | |
50 | #if 0 | |
51 | #define DEBUGP printk | |
52 | #else | |
53 | #define DEBUGP(format, args...) | |
54 | #endif | |
55 | ||
e45b1be8 | 56 | DEFINE_RWLOCK(ip_conntrack_lock); |
1da177e4 LT |
57 | |
58 | /* ip_conntrack_standalone needs this */ | |
59 | atomic_t ip_conntrack_count = ATOMIC_INIT(0); | |
60 | ||
61 | void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack) = NULL; | |
62 | LIST_HEAD(ip_conntrack_expect_list); | |
1192e403 | 63 | struct ip_conntrack_protocol *ip_ct_protos[MAX_IP_CT_PROTO] __read_mostly; |
1da177e4 | 64 | static LIST_HEAD(helpers); |
94aec08e BH |
65 | unsigned int ip_conntrack_htable_size __read_mostly = 0; |
66 | int ip_conntrack_max __read_mostly; | |
1192e403 | 67 | struct list_head *ip_conntrack_hash __read_mostly; |
e18b890b CL |
68 | static struct kmem_cache *ip_conntrack_cachep __read_mostly; |
69 | static struct kmem_cache *ip_conntrack_expect_cachep __read_mostly; | |
1da177e4 | 70 | struct ip_conntrack ip_conntrack_untracked; |
94aec08e | 71 | unsigned int ip_ct_log_invalid __read_mostly; |
1da177e4 | 72 | static LIST_HEAD(unconfirmed); |
1192e403 | 73 | static int ip_conntrack_vmalloc __read_mostly; |
1da177e4 | 74 | |
4e3882f7 PNA |
75 | static unsigned int ip_conntrack_next_id; |
76 | static unsigned int ip_conntrack_expect_next_id; | |
ac3247ba | 77 | #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS |
e041c683 AS |
78 | ATOMIC_NOTIFIER_HEAD(ip_conntrack_chain); |
79 | ATOMIC_NOTIFIER_HEAD(ip_conntrack_expect_chain); | |
ac3247ba HW |
80 | |
81 | DEFINE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache); | |
82 | ||
a86888b9 PM |
83 | /* deliver cached events and clear cache entry - must be called with locally |
84 | * disabled softirqs */ | |
85 | static inline void | |
86 | __ip_ct_deliver_cached_events(struct ip_conntrack_ecache *ecache) | |
ac3247ba | 87 | { |
a86888b9 | 88 | DEBUGP("ecache: delivering events for %p\n", ecache->ct); |
ac3247ba | 89 | if (is_confirmed(ecache->ct) && !is_dying(ecache->ct) && ecache->events) |
e041c683 | 90 | atomic_notifier_call_chain(&ip_conntrack_chain, ecache->events, |
ac3247ba HW |
91 | ecache->ct); |
92 | ecache->events = 0; | |
a86888b9 PM |
93 | ip_conntrack_put(ecache->ct); |
94 | ecache->ct = NULL; | |
ac3247ba HW |
95 | } |
96 | ||
97 | /* Deliver all cached events for a particular conntrack. This is called | |
98 | * by code prior to async packet handling or freeing the skb */ | |
a86888b9 | 99 | void ip_ct_deliver_cached_events(const struct ip_conntrack *ct) |
ac3247ba | 100 | { |
a86888b9 PM |
101 | struct ip_conntrack_ecache *ecache; |
102 | ||
103 | local_bh_disable(); | |
104 | ecache = &__get_cpu_var(ip_conntrack_ecache); | |
105 | if (ecache->ct == ct) | |
106 | __ip_ct_deliver_cached_events(ecache); | |
107 | local_bh_enable(); | |
108 | } | |
ac3247ba | 109 | |
a86888b9 PM |
110 | void __ip_ct_event_cache_init(struct ip_conntrack *ct) |
111 | { | |
112 | struct ip_conntrack_ecache *ecache; | |
ac3247ba | 113 | |
a86888b9 PM |
114 | /* take care of delivering potentially old events */ |
115 | ecache = &__get_cpu_var(ip_conntrack_ecache); | |
116 | BUG_ON(ecache->ct == ct); | |
117 | if (ecache->ct) | |
118 | __ip_ct_deliver_cached_events(ecache); | |
119 | /* initialize for this conntrack/packet */ | |
120 | ecache->ct = ct; | |
121 | nf_conntrack_get(&ct->ct_general); | |
ac3247ba HW |
122 | } |
123 | ||
a86888b9 PM |
124 | /* flush the event cache - touches other CPU's data and must not be called while |
125 | * packets are still passing through the code */ | |
126 | static void ip_ct_event_cache_flush(void) | |
ac3247ba | 127 | { |
a86888b9 PM |
128 | struct ip_conntrack_ecache *ecache; |
129 | int cpu; | |
ac3247ba | 130 | |
6f912042 | 131 | for_each_possible_cpu(cpu) { |
a86888b9 PM |
132 | ecache = &per_cpu(ip_conntrack_ecache, cpu); |
133 | if (ecache->ct) | |
ac3247ba | 134 | ip_conntrack_put(ecache->ct); |
ac3247ba HW |
135 | } |
136 | } | |
a86888b9 PM |
137 | #else |
138 | static inline void ip_ct_event_cache_flush(void) {} | |
ac3247ba HW |
139 | #endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */ |
140 | ||
1da177e4 LT |
141 | DEFINE_PER_CPU(struct ip_conntrack_stat, ip_conntrack_stat); |
142 | ||
1da177e4 LT |
143 | static int ip_conntrack_hash_rnd_initted; |
144 | static unsigned int ip_conntrack_hash_rnd; | |
145 | ||
eed75f19 HW |
146 | static u_int32_t __hash_conntrack(const struct ip_conntrack_tuple *tuple, |
147 | unsigned int size, unsigned int rnd) | |
1da177e4 | 148 | { |
cdcb71bf AV |
149 | return (jhash_3words((__force u32)tuple->src.ip, |
150 | ((__force u32)tuple->dst.ip ^ tuple->dst.protonum), | |
1da177e4 | 151 | (tuple->src.u.all | (tuple->dst.u.all << 16)), |
eed75f19 HW |
152 | rnd) % size); |
153 | } | |
154 | ||
155 | static u_int32_t | |
156 | hash_conntrack(const struct ip_conntrack_tuple *tuple) | |
157 | { | |
158 | return __hash_conntrack(tuple, ip_conntrack_htable_size, | |
159 | ip_conntrack_hash_rnd); | |
1da177e4 LT |
160 | } |
161 | ||
162 | int | |
163 | ip_ct_get_tuple(const struct iphdr *iph, | |
164 | const struct sk_buff *skb, | |
165 | unsigned int dataoff, | |
166 | struct ip_conntrack_tuple *tuple, | |
167 | const struct ip_conntrack_protocol *protocol) | |
168 | { | |
169 | /* Never happen */ | |
170 | if (iph->frag_off & htons(IP_OFFSET)) { | |
171 | printk("ip_conntrack_core: Frag of proto %u.\n", | |
172 | iph->protocol); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | tuple->src.ip = iph->saddr; | |
177 | tuple->dst.ip = iph->daddr; | |
178 | tuple->dst.protonum = iph->protocol; | |
179 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
180 | ||
181 | return protocol->pkt_to_tuple(skb, dataoff, tuple); | |
182 | } | |
183 | ||
184 | int | |
185 | ip_ct_invert_tuple(struct ip_conntrack_tuple *inverse, | |
186 | const struct ip_conntrack_tuple *orig, | |
187 | const struct ip_conntrack_protocol *protocol) | |
188 | { | |
189 | inverse->src.ip = orig->dst.ip; | |
190 | inverse->dst.ip = orig->src.ip; | |
191 | inverse->dst.protonum = orig->dst.protonum; | |
192 | inverse->dst.dir = !orig->dst.dir; | |
193 | ||
194 | return protocol->invert_tuple(inverse, orig); | |
195 | } | |
196 | ||
197 | ||
198 | /* ip_conntrack_expect helper functions */ | |
49719eb3 | 199 | void ip_ct_unlink_expect(struct ip_conntrack_expect *exp) |
1da177e4 | 200 | { |
4acdbdbe | 201 | IP_NF_ASSERT(!timer_pending(&exp->timeout)); |
1da177e4 | 202 | list_del(&exp->list); |
4acdbdbe | 203 | CONNTRACK_STAT_INC(expect_delete); |
1da177e4 | 204 | exp->master->expecting--; |
37012f7f | 205 | ip_conntrack_expect_put(exp); |
1da177e4 LT |
206 | } |
207 | ||
208 | static void expectation_timed_out(unsigned long ul_expect) | |
209 | { | |
210 | struct ip_conntrack_expect *exp = (void *)ul_expect; | |
211 | ||
e45b1be8 | 212 | write_lock_bh(&ip_conntrack_lock); |
49719eb3 | 213 | ip_ct_unlink_expect(exp); |
e45b1be8 | 214 | write_unlock_bh(&ip_conntrack_lock); |
4acdbdbe | 215 | ip_conntrack_expect_put(exp); |
1da177e4 LT |
216 | } |
217 | ||
080774a2 HW |
218 | struct ip_conntrack_expect * |
219 | __ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple) | |
220 | { | |
221 | struct ip_conntrack_expect *i; | |
222 | ||
223 | list_for_each_entry(i, &ip_conntrack_expect_list, list) { | |
2e47c264 | 224 | if (ip_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) |
080774a2 | 225 | return i; |
080774a2 HW |
226 | } |
227 | return NULL; | |
228 | } | |
229 | ||
230 | /* Just find a expectation corresponding to a tuple. */ | |
231 | struct ip_conntrack_expect * | |
468ec44b | 232 | ip_conntrack_expect_find_get(const struct ip_conntrack_tuple *tuple) |
080774a2 HW |
233 | { |
234 | struct ip_conntrack_expect *i; | |
235 | ||
236 | read_lock_bh(&ip_conntrack_lock); | |
237 | i = __ip_conntrack_expect_find(tuple); | |
2e47c264 YK |
238 | if (i) |
239 | atomic_inc(&i->use); | |
080774a2 HW |
240 | read_unlock_bh(&ip_conntrack_lock); |
241 | ||
242 | return i; | |
243 | } | |
244 | ||
1da177e4 LT |
245 | /* If an expectation for this connection is found, it gets delete from |
246 | * global list then returned. */ | |
247 | static struct ip_conntrack_expect * | |
248 | find_expectation(const struct ip_conntrack_tuple *tuple) | |
249 | { | |
250 | struct ip_conntrack_expect *i; | |
251 | ||
252 | list_for_each_entry(i, &ip_conntrack_expect_list, list) { | |
253 | /* If master is not in hash table yet (ie. packet hasn't left | |
254 | this machine yet), how can other end know about expected? | |
255 | Hence these are not the droids you are looking for (if | |
256 | master ct never got confirmed, we'd hold a reference to it | |
257 | and weird things would happen to future packets). */ | |
258 | if (ip_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) | |
2248bcfc PM |
259 | && is_confirmed(i->master)) { |
260 | if (i->flags & IP_CT_EXPECT_PERMANENT) { | |
261 | atomic_inc(&i->use); | |
262 | return i; | |
263 | } else if (del_timer(&i->timeout)) { | |
49719eb3 | 264 | ip_ct_unlink_expect(i); |
2248bcfc PM |
265 | return i; |
266 | } | |
1da177e4 LT |
267 | } |
268 | } | |
269 | return NULL; | |
270 | } | |
271 | ||
272 | /* delete all expectations for this conntrack */ | |
080774a2 | 273 | void ip_ct_remove_expectations(struct ip_conntrack *ct) |
1da177e4 LT |
274 | { |
275 | struct ip_conntrack_expect *i, *tmp; | |
276 | ||
277 | /* Optimization: most connection never expect any others. */ | |
278 | if (ct->expecting == 0) | |
279 | return; | |
280 | ||
281 | list_for_each_entry_safe(i, tmp, &ip_conntrack_expect_list, list) { | |
282 | if (i->master == ct && del_timer(&i->timeout)) { | |
49719eb3 | 283 | ip_ct_unlink_expect(i); |
4acdbdbe | 284 | ip_conntrack_expect_put(i); |
1da177e4 LT |
285 | } |
286 | } | |
287 | } | |
288 | ||
289 | static void | |
290 | clean_from_lists(struct ip_conntrack *ct) | |
291 | { | |
1da177e4 | 292 | DEBUGP("clean_from_lists(%p)\n", ct); |
df0933dc PM |
293 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); |
294 | list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list); | |
1da177e4 LT |
295 | |
296 | /* Destroy all pending expectations */ | |
080774a2 | 297 | ip_ct_remove_expectations(ct); |
1da177e4 LT |
298 | } |
299 | ||
300 | static void | |
301 | destroy_conntrack(struct nf_conntrack *nfct) | |
302 | { | |
303 | struct ip_conntrack *ct = (struct ip_conntrack *)nfct; | |
304 | struct ip_conntrack_protocol *proto; | |
4c5de695 | 305 | struct ip_conntrack_helper *helper; |
1da177e4 LT |
306 | |
307 | DEBUGP("destroy_conntrack(%p)\n", ct); | |
308 | IP_NF_ASSERT(atomic_read(&nfct->use) == 0); | |
309 | IP_NF_ASSERT(!timer_pending(&ct->timeout)); | |
310 | ||
14a50bba | 311 | ip_conntrack_event(IPCT_DESTROY, ct); |
ac3247ba HW |
312 | set_bit(IPS_DYING_BIT, &ct->status); |
313 | ||
4c5de695 PM |
314 | helper = ct->helper; |
315 | if (helper && helper->destroy) | |
316 | helper->destroy(ct); | |
317 | ||
1da177e4 LT |
318 | /* To make sure we don't get any weird locking issues here: |
319 | * destroy_conntrack() MUST NOT be called with a write lock | |
320 | * to ip_conntrack_lock!!! -HW */ | |
080774a2 | 321 | proto = __ip_conntrack_proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); |
1da177e4 LT |
322 | if (proto && proto->destroy) |
323 | proto->destroy(ct); | |
324 | ||
325 | if (ip_conntrack_destroyed) | |
326 | ip_conntrack_destroyed(ct); | |
327 | ||
e45b1be8 | 328 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
329 | /* Expectations will have been removed in clean_from_lists, |
330 | * except TFTP can create an expectation on the first packet, | |
331 | * before connection is in the list, so we need to clean here, | |
332 | * too. */ | |
080774a2 | 333 | ip_ct_remove_expectations(ct); |
1da177e4 LT |
334 | |
335 | /* We overload first tuple to link into unconfirmed list. */ | |
336 | if (!is_confirmed(ct)) { | |
337 | BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list)); | |
338 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
339 | } | |
340 | ||
341 | CONNTRACK_STAT_INC(delete); | |
e45b1be8 | 342 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
343 | |
344 | if (ct->master) | |
345 | ip_conntrack_put(ct->master); | |
346 | ||
347 | DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct); | |
080774a2 | 348 | ip_conntrack_free(ct); |
1da177e4 LT |
349 | } |
350 | ||
351 | static void death_by_timeout(unsigned long ul_conntrack) | |
352 | { | |
353 | struct ip_conntrack *ct = (void *)ul_conntrack; | |
354 | ||
e45b1be8 | 355 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
356 | /* Inside lock so preempt is disabled on module removal path. |
357 | * Otherwise we can get spurious warnings. */ | |
358 | CONNTRACK_STAT_INC(delete_list); | |
359 | clean_from_lists(ct); | |
e45b1be8 | 360 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
361 | ip_conntrack_put(ct); |
362 | } | |
363 | ||
080774a2 | 364 | struct ip_conntrack_tuple_hash * |
1da177e4 LT |
365 | __ip_conntrack_find(const struct ip_conntrack_tuple *tuple, |
366 | const struct ip_conntrack *ignored_conntrack) | |
367 | { | |
368 | struct ip_conntrack_tuple_hash *h; | |
369 | unsigned int hash = hash_conntrack(tuple); | |
370 | ||
1da177e4 | 371 | list_for_each_entry(h, &ip_conntrack_hash[hash], list) { |
df0933dc PM |
372 | if (tuplehash_to_ctrack(h) != ignored_conntrack && |
373 | ip_ct_tuple_equal(tuple, &h->tuple)) { | |
1da177e4 LT |
374 | CONNTRACK_STAT_INC(found); |
375 | return h; | |
376 | } | |
377 | CONNTRACK_STAT_INC(searched); | |
378 | } | |
379 | ||
380 | return NULL; | |
381 | } | |
382 | ||
383 | /* Find a connection corresponding to a tuple. */ | |
384 | struct ip_conntrack_tuple_hash * | |
385 | ip_conntrack_find_get(const struct ip_conntrack_tuple *tuple, | |
386 | const struct ip_conntrack *ignored_conntrack) | |
387 | { | |
388 | struct ip_conntrack_tuple_hash *h; | |
389 | ||
e45b1be8 | 390 | read_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
391 | h = __ip_conntrack_find(tuple, ignored_conntrack); |
392 | if (h) | |
393 | atomic_inc(&tuplehash_to_ctrack(h)->ct_general.use); | |
e45b1be8 | 394 | read_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
395 | |
396 | return h; | |
397 | } | |
398 | ||
080774a2 HW |
399 | static void __ip_conntrack_hash_insert(struct ip_conntrack *ct, |
400 | unsigned int hash, | |
401 | unsigned int repl_hash) | |
402 | { | |
403 | ct->id = ++ip_conntrack_next_id; | |
df0933dc PM |
404 | list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list, |
405 | &ip_conntrack_hash[hash]); | |
406 | list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list, | |
407 | &ip_conntrack_hash[repl_hash]); | |
080774a2 HW |
408 | } |
409 | ||
410 | void ip_conntrack_hash_insert(struct ip_conntrack *ct) | |
411 | { | |
412 | unsigned int hash, repl_hash; | |
413 | ||
414 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
415 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
416 | ||
417 | write_lock_bh(&ip_conntrack_lock); | |
418 | __ip_conntrack_hash_insert(ct, hash, repl_hash); | |
419 | write_unlock_bh(&ip_conntrack_lock); | |
420 | } | |
421 | ||
1da177e4 LT |
422 | /* Confirm a connection given skb; places it in hash table */ |
423 | int | |
424 | __ip_conntrack_confirm(struct sk_buff **pskb) | |
425 | { | |
426 | unsigned int hash, repl_hash; | |
df0933dc | 427 | struct ip_conntrack_tuple_hash *h; |
1da177e4 LT |
428 | struct ip_conntrack *ct; |
429 | enum ip_conntrack_info ctinfo; | |
430 | ||
431 | ct = ip_conntrack_get(*pskb, &ctinfo); | |
432 | ||
433 | /* ipt_REJECT uses ip_conntrack_attach to attach related | |
434 | ICMP/TCP RST packets in other direction. Actual packet | |
435 | which created connection will be IP_CT_NEW or for an | |
436 | expected connection, IP_CT_RELATED. */ | |
437 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
438 | return NF_ACCEPT; | |
439 | ||
440 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
441 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
442 | ||
443 | /* We're not in hash table, and we refuse to set up related | |
444 | connections for unconfirmed conns. But packet copies and | |
445 | REJECT will give spurious warnings here. */ | |
446 | /* IP_NF_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
447 | ||
448 | /* No external references means noone else could have | |
449 | confirmed us. */ | |
450 | IP_NF_ASSERT(!is_confirmed(ct)); | |
451 | DEBUGP("Confirming conntrack %p\n", ct); | |
452 | ||
e45b1be8 | 453 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
454 | |
455 | /* See if there's one in the list already, including reverse: | |
456 | NAT could have grabbed it without realizing, since we're | |
457 | not in the hash. If there is, we lost race. */ | |
df0933dc PM |
458 | list_for_each_entry(h, &ip_conntrack_hash[hash], list) |
459 | if (ip_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, | |
460 | &h->tuple)) | |
461 | goto out; | |
462 | list_for_each_entry(h, &ip_conntrack_hash[repl_hash], list) | |
463 | if (ip_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, | |
464 | &h->tuple)) | |
465 | goto out; | |
1da177e4 | 466 | |
df0933dc PM |
467 | /* Remove from unconfirmed list */ |
468 | list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list); | |
469 | ||
470 | __ip_conntrack_hash_insert(ct, hash, repl_hash); | |
471 | /* Timer relative to confirmation time, not original | |
472 | setting time, otherwise we'd get timer wrap in | |
473 | weird delay cases. */ | |
474 | ct->timeout.expires += jiffies; | |
475 | add_timer(&ct->timeout); | |
476 | atomic_inc(&ct->ct_general.use); | |
477 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
478 | CONNTRACK_STAT_INC(insert); | |
479 | write_unlock_bh(&ip_conntrack_lock); | |
480 | if (ct->helper) | |
481 | ip_conntrack_event_cache(IPCT_HELPER, *pskb); | |
ac3247ba | 482 | #ifdef CONFIG_IP_NF_NAT_NEEDED |
df0933dc PM |
483 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || |
484 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
485 | ip_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
ac3247ba | 486 | #endif |
df0933dc PM |
487 | ip_conntrack_event_cache(master_ct(ct) ? |
488 | IPCT_RELATED : IPCT_NEW, *pskb); | |
ac3247ba | 489 | |
df0933dc | 490 | return NF_ACCEPT; |
1da177e4 | 491 | |
df0933dc | 492 | out: |
1da177e4 | 493 | CONNTRACK_STAT_INC(insert_failed); |
e45b1be8 | 494 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
495 | return NF_DROP; |
496 | } | |
497 | ||
498 | /* Returns true if a connection correspondings to the tuple (required | |
499 | for NAT). */ | |
500 | int | |
501 | ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple, | |
502 | const struct ip_conntrack *ignored_conntrack) | |
503 | { | |
504 | struct ip_conntrack_tuple_hash *h; | |
505 | ||
e45b1be8 | 506 | read_lock_bh(&ip_conntrack_lock); |
1da177e4 | 507 | h = __ip_conntrack_find(tuple, ignored_conntrack); |
e45b1be8 | 508 | read_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
509 | |
510 | return h != NULL; | |
511 | } | |
512 | ||
513 | /* There's a small race here where we may free a just-assured | |
514 | connection. Too bad: we're in trouble anyway. */ | |
1da177e4 LT |
515 | static int early_drop(struct list_head *chain) |
516 | { | |
517 | /* Traverse backwards: gives us oldest, which is roughly LRU */ | |
518 | struct ip_conntrack_tuple_hash *h; | |
df0933dc | 519 | struct ip_conntrack *ct = NULL, *tmp; |
1da177e4 LT |
520 | int dropped = 0; |
521 | ||
e45b1be8 | 522 | read_lock_bh(&ip_conntrack_lock); |
df0933dc PM |
523 | list_for_each_entry_reverse(h, chain, list) { |
524 | tmp = tuplehash_to_ctrack(h); | |
525 | if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) { | |
526 | ct = tmp; | |
527 | atomic_inc(&ct->ct_general.use); | |
528 | break; | |
529 | } | |
1da177e4 | 530 | } |
e45b1be8 | 531 | read_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
532 | |
533 | if (!ct) | |
534 | return dropped; | |
535 | ||
536 | if (del_timer(&ct->timeout)) { | |
537 | death_by_timeout((unsigned long)ct); | |
538 | dropped = 1; | |
539 | CONNTRACK_STAT_INC(early_drop); | |
540 | } | |
541 | ip_conntrack_put(ct); | |
542 | return dropped; | |
543 | } | |
544 | ||
080774a2 HW |
545 | static struct ip_conntrack_helper * |
546 | __ip_conntrack_helper_find( const struct ip_conntrack_tuple *tuple) | |
1da177e4 | 547 | { |
df0933dc PM |
548 | struct ip_conntrack_helper *h; |
549 | ||
550 | list_for_each_entry(h, &helpers, list) { | |
551 | if (ip_ct_tuple_mask_cmp(tuple, &h->tuple, &h->mask)) | |
552 | return h; | |
553 | } | |
554 | return NULL; | |
1da177e4 LT |
555 | } |
556 | ||
080774a2 HW |
557 | struct ip_conntrack_helper * |
558 | ip_conntrack_helper_find_get( const struct ip_conntrack_tuple *tuple) | |
559 | { | |
560 | struct ip_conntrack_helper *helper; | |
561 | ||
562 | /* need ip_conntrack_lock to assure that helper exists until | |
563 | * try_module_get() is called */ | |
564 | read_lock_bh(&ip_conntrack_lock); | |
565 | ||
566 | helper = __ip_conntrack_helper_find(tuple); | |
567 | if (helper) { | |
568 | /* need to increase module usage count to assure helper will | |
569 | * not go away while the caller is e.g. busy putting a | |
570 | * conntrack in the hash that uses the helper */ | |
571 | if (!try_module_get(helper->me)) | |
572 | helper = NULL; | |
573 | } | |
574 | ||
575 | read_unlock_bh(&ip_conntrack_lock); | |
576 | ||
577 | return helper; | |
578 | } | |
579 | ||
580 | void ip_conntrack_helper_put(struct ip_conntrack_helper *helper) | |
581 | { | |
582 | module_put(helper->me); | |
583 | } | |
584 | ||
585 | struct ip_conntrack_protocol * | |
586 | __ip_conntrack_proto_find(u_int8_t protocol) | |
587 | { | |
588 | return ip_ct_protos[protocol]; | |
589 | } | |
590 | ||
591 | /* this is guaranteed to always return a valid protocol helper, since | |
592 | * it falls back to generic_protocol */ | |
593 | struct ip_conntrack_protocol * | |
594 | ip_conntrack_proto_find_get(u_int8_t protocol) | |
595 | { | |
596 | struct ip_conntrack_protocol *p; | |
597 | ||
598 | preempt_disable(); | |
599 | p = __ip_conntrack_proto_find(protocol); | |
600 | if (p) { | |
601 | if (!try_module_get(p->me)) | |
602 | p = &ip_conntrack_generic_protocol; | |
603 | } | |
604 | preempt_enable(); | |
605 | ||
606 | return p; | |
607 | } | |
608 | ||
609 | void ip_conntrack_proto_put(struct ip_conntrack_protocol *p) | |
610 | { | |
611 | module_put(p->me); | |
612 | } | |
613 | ||
614 | struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *orig, | |
615 | struct ip_conntrack_tuple *repl) | |
1da177e4 LT |
616 | { |
617 | struct ip_conntrack *conntrack; | |
1da177e4 LT |
618 | |
619 | if (!ip_conntrack_hash_rnd_initted) { | |
620 | get_random_bytes(&ip_conntrack_hash_rnd, 4); | |
621 | ip_conntrack_hash_rnd_initted = 1; | |
622 | } | |
623 | ||
5251e2d2 PNA |
624 | /* We don't want any race condition at early drop stage */ |
625 | atomic_inc(&ip_conntrack_count); | |
626 | ||
1da177e4 | 627 | if (ip_conntrack_max |
5251e2d2 | 628 | && atomic_read(&ip_conntrack_count) > ip_conntrack_max) { |
080774a2 | 629 | unsigned int hash = hash_conntrack(orig); |
1da177e4 LT |
630 | /* Try dropping from this hash chain. */ |
631 | if (!early_drop(&ip_conntrack_hash[hash])) { | |
5251e2d2 | 632 | atomic_dec(&ip_conntrack_count); |
1da177e4 LT |
633 | if (net_ratelimit()) |
634 | printk(KERN_WARNING | |
635 | "ip_conntrack: table full, dropping" | |
636 | " packet.\n"); | |
637 | return ERR_PTR(-ENOMEM); | |
638 | } | |
639 | } | |
640 | ||
1da177e4 LT |
641 | conntrack = kmem_cache_alloc(ip_conntrack_cachep, GFP_ATOMIC); |
642 | if (!conntrack) { | |
643 | DEBUGP("Can't allocate conntrack.\n"); | |
5251e2d2 | 644 | atomic_dec(&ip_conntrack_count); |
7663f188 | 645 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
646 | } |
647 | ||
648 | memset(conntrack, 0, sizeof(*conntrack)); | |
649 | atomic_set(&conntrack->ct_general.use, 1); | |
650 | conntrack->ct_general.destroy = destroy_conntrack; | |
080774a2 HW |
651 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; |
652 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
1da177e4 LT |
653 | /* Don't set timer yet: wait for confirmation */ |
654 | init_timer(&conntrack->timeout); | |
655 | conntrack->timeout.data = (unsigned long)conntrack; | |
656 | conntrack->timeout.function = death_by_timeout; | |
657 | ||
080774a2 HW |
658 | return conntrack; |
659 | } | |
660 | ||
661 | void | |
662 | ip_conntrack_free(struct ip_conntrack *conntrack) | |
663 | { | |
664 | atomic_dec(&ip_conntrack_count); | |
665 | kmem_cache_free(ip_conntrack_cachep, conntrack); | |
666 | } | |
667 | ||
668 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
669 | * failed due to stress. Otherwise it really is unclassifiable */ | |
670 | static struct ip_conntrack_tuple_hash * | |
671 | init_conntrack(struct ip_conntrack_tuple *tuple, | |
672 | struct ip_conntrack_protocol *protocol, | |
673 | struct sk_buff *skb) | |
674 | { | |
675 | struct ip_conntrack *conntrack; | |
676 | struct ip_conntrack_tuple repl_tuple; | |
677 | struct ip_conntrack_expect *exp; | |
678 | ||
679 | if (!ip_ct_invert_tuple(&repl_tuple, tuple, protocol)) { | |
680 | DEBUGP("Can't invert tuple.\n"); | |
681 | return NULL; | |
682 | } | |
683 | ||
7663f188 YK |
684 | conntrack = ip_conntrack_alloc(tuple, &repl_tuple); |
685 | if (conntrack == NULL || IS_ERR(conntrack)) | |
686 | return (struct ip_conntrack_tuple_hash *)conntrack; | |
080774a2 HW |
687 | |
688 | if (!protocol->new(conntrack, skb)) { | |
689 | ip_conntrack_free(conntrack); | |
690 | return NULL; | |
691 | } | |
692 | ||
e45b1be8 | 693 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
694 | exp = find_expectation(tuple); |
695 | ||
696 | if (exp) { | |
697 | DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", | |
698 | conntrack, exp); | |
699 | /* Welcome, Mr. Bond. We've been expecting you... */ | |
700 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
701 | conntrack->master = exp->master; | |
7cee432a | 702 | #ifdef CONFIG_IP_NF_CONNTRACK_MARK |
1da177e4 | 703 | conntrack->mark = exp->master->mark; |
1f494c0e HW |
704 | #endif |
705 | #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \ | |
706 | defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE) | |
707 | /* this is ugly, but there is no other place where to put it */ | |
708 | conntrack->nat.masq_index = exp->master->nat.masq_index; | |
7c9728c3 JM |
709 | #endif |
710 | #ifdef CONFIG_IP_NF_CONNTRACK_SECMARK | |
711 | conntrack->secmark = exp->master->secmark; | |
1da177e4 LT |
712 | #endif |
713 | nf_conntrack_get(&conntrack->master->ct_general); | |
714 | CONNTRACK_STAT_INC(expect_new); | |
715 | } else { | |
080774a2 | 716 | conntrack->helper = __ip_conntrack_helper_find(&repl_tuple); |
1da177e4 LT |
717 | |
718 | CONNTRACK_STAT_INC(new); | |
719 | } | |
720 | ||
721 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
722 | list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); | |
723 | ||
e45b1be8 | 724 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
725 | |
726 | if (exp) { | |
727 | if (exp->expectfn) | |
728 | exp->expectfn(conntrack, exp); | |
4acdbdbe | 729 | ip_conntrack_expect_put(exp); |
1da177e4 LT |
730 | } |
731 | ||
732 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
733 | } | |
734 | ||
735 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
736 | static inline struct ip_conntrack * | |
737 | resolve_normal_ct(struct sk_buff *skb, | |
738 | struct ip_conntrack_protocol *proto, | |
739 | int *set_reply, | |
740 | unsigned int hooknum, | |
741 | enum ip_conntrack_info *ctinfo) | |
742 | { | |
743 | struct ip_conntrack_tuple tuple; | |
744 | struct ip_conntrack_tuple_hash *h; | |
745 | struct ip_conntrack *ct; | |
746 | ||
747 | IP_NF_ASSERT((skb->nh.iph->frag_off & htons(IP_OFFSET)) == 0); | |
748 | ||
749 | if (!ip_ct_get_tuple(skb->nh.iph, skb, skb->nh.iph->ihl*4, | |
750 | &tuple,proto)) | |
751 | return NULL; | |
752 | ||
753 | /* look for tuple match */ | |
754 | h = ip_conntrack_find_get(&tuple, NULL); | |
755 | if (!h) { | |
756 | h = init_conntrack(&tuple, proto, skb); | |
757 | if (!h) | |
758 | return NULL; | |
759 | if (IS_ERR(h)) | |
760 | return (void *)h; | |
761 | } | |
762 | ct = tuplehash_to_ctrack(h); | |
763 | ||
764 | /* It exists; we have (non-exclusive) reference. */ | |
765 | if (DIRECTION(h) == IP_CT_DIR_REPLY) { | |
766 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
767 | /* Please set reply bit if this packet OK */ | |
768 | *set_reply = 1; | |
769 | } else { | |
770 | /* Once we've had two way comms, always ESTABLISHED. */ | |
771 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
772 | DEBUGP("ip_conntrack_in: normal packet for %p\n", | |
773 | ct); | |
774 | *ctinfo = IP_CT_ESTABLISHED; | |
775 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
776 | DEBUGP("ip_conntrack_in: related packet for %p\n", | |
777 | ct); | |
778 | *ctinfo = IP_CT_RELATED; | |
779 | } else { | |
780 | DEBUGP("ip_conntrack_in: new packet for %p\n", | |
781 | ct); | |
782 | *ctinfo = IP_CT_NEW; | |
783 | } | |
784 | *set_reply = 0; | |
785 | } | |
786 | skb->nfct = &ct->ct_general; | |
787 | skb->nfctinfo = *ctinfo; | |
788 | return ct; | |
789 | } | |
790 | ||
791 | /* Netfilter hook itself. */ | |
792 | unsigned int ip_conntrack_in(unsigned int hooknum, | |
793 | struct sk_buff **pskb, | |
794 | const struct net_device *in, | |
795 | const struct net_device *out, | |
796 | int (*okfn)(struct sk_buff *)) | |
797 | { | |
798 | struct ip_conntrack *ct; | |
799 | enum ip_conntrack_info ctinfo; | |
800 | struct ip_conntrack_protocol *proto; | |
ac3247ba | 801 | int set_reply = 0; |
1da177e4 LT |
802 | int ret; |
803 | ||
804 | /* Previously seen (loopback or untracked)? Ignore. */ | |
805 | if ((*pskb)->nfct) { | |
806 | CONNTRACK_STAT_INC(ignore); | |
807 | return NF_ACCEPT; | |
808 | } | |
809 | ||
810 | /* Never happen */ | |
811 | if ((*pskb)->nh.iph->frag_off & htons(IP_OFFSET)) { | |
812 | if (net_ratelimit()) { | |
813 | printk(KERN_ERR "ip_conntrack_in: Frag of proto %u (hook=%u)\n", | |
814 | (*pskb)->nh.iph->protocol, hooknum); | |
815 | } | |
816 | return NF_DROP; | |
817 | } | |
818 | ||
1da177e4 LT |
819 | /* Doesn't cover locally-generated broadcast, so not worth it. */ |
820 | #if 0 | |
821 | /* Ignore broadcast: no `connection'. */ | |
822 | if ((*pskb)->pkt_type == PACKET_BROADCAST) { | |
823 | printk("Broadcast packet!\n"); | |
824 | return NF_ACCEPT; | |
825 | } else if (((*pskb)->nh.iph->daddr & htonl(0x000000FF)) | |
826 | == htonl(0x000000FF)) { | |
827 | printk("Should bcast: %u.%u.%u.%u->%u.%u.%u.%u (sk=%p, ptype=%u)\n", | |
828 | NIPQUAD((*pskb)->nh.iph->saddr), | |
829 | NIPQUAD((*pskb)->nh.iph->daddr), | |
830 | (*pskb)->sk, (*pskb)->pkt_type); | |
831 | } | |
832 | #endif | |
833 | ||
080774a2 | 834 | proto = __ip_conntrack_proto_find((*pskb)->nh.iph->protocol); |
1da177e4 LT |
835 | |
836 | /* It may be an special packet, error, unclean... | |
837 | * inverse of the return code tells to the netfilter | |
838 | * core what to do with the packet. */ | |
839 | if (proto->error != NULL | |
840 | && (ret = proto->error(*pskb, &ctinfo, hooknum)) <= 0) { | |
841 | CONNTRACK_STAT_INC(error); | |
842 | CONNTRACK_STAT_INC(invalid); | |
843 | return -ret; | |
844 | } | |
845 | ||
846 | if (!(ct = resolve_normal_ct(*pskb, proto,&set_reply,hooknum,&ctinfo))) { | |
847 | /* Not valid part of a connection */ | |
848 | CONNTRACK_STAT_INC(invalid); | |
849 | return NF_ACCEPT; | |
850 | } | |
851 | ||
852 | if (IS_ERR(ct)) { | |
853 | /* Too stressed to deal. */ | |
854 | CONNTRACK_STAT_INC(drop); | |
855 | return NF_DROP; | |
856 | } | |
857 | ||
858 | IP_NF_ASSERT((*pskb)->nfct); | |
859 | ||
860 | ret = proto->packet(ct, *pskb, ctinfo); | |
861 | if (ret < 0) { | |
862 | /* Invalid: inverse of the return code tells | |
863 | * the netfilter core what to do*/ | |
864 | nf_conntrack_put((*pskb)->nfct); | |
865 | (*pskb)->nfct = NULL; | |
866 | CONNTRACK_STAT_INC(invalid); | |
867 | return -ret; | |
868 | } | |
869 | ||
ac3247ba HW |
870 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) |
871 | ip_conntrack_event_cache(IPCT_STATUS, *pskb); | |
1da177e4 LT |
872 | |
873 | return ret; | |
874 | } | |
875 | ||
876 | int invert_tuplepr(struct ip_conntrack_tuple *inverse, | |
877 | const struct ip_conntrack_tuple *orig) | |
878 | { | |
879 | return ip_ct_invert_tuple(inverse, orig, | |
080774a2 | 880 | __ip_conntrack_proto_find(orig->dst.protonum)); |
1da177e4 LT |
881 | } |
882 | ||
883 | /* Would two expected things clash? */ | |
884 | static inline int expect_clash(const struct ip_conntrack_expect *a, | |
885 | const struct ip_conntrack_expect *b) | |
886 | { | |
887 | /* Part covered by intersection of masks must be unequal, | |
888 | otherwise they clash */ | |
889 | struct ip_conntrack_tuple intersect_mask | |
890 | = { { a->mask.src.ip & b->mask.src.ip, | |
891 | { a->mask.src.u.all & b->mask.src.u.all } }, | |
892 | { a->mask.dst.ip & b->mask.dst.ip, | |
893 | { a->mask.dst.u.all & b->mask.dst.u.all }, | |
894 | a->mask.dst.protonum & b->mask.dst.protonum } }; | |
895 | ||
896 | return ip_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask); | |
897 | } | |
898 | ||
899 | static inline int expect_matches(const struct ip_conntrack_expect *a, | |
900 | const struct ip_conntrack_expect *b) | |
901 | { | |
902 | return a->master == b->master | |
903 | && ip_ct_tuple_equal(&a->tuple, &b->tuple) | |
904 | && ip_ct_tuple_equal(&a->mask, &b->mask); | |
905 | } | |
906 | ||
907 | /* Generally a bad idea to call this: could have matched already. */ | |
908 | void ip_conntrack_unexpect_related(struct ip_conntrack_expect *exp) | |
909 | { | |
910 | struct ip_conntrack_expect *i; | |
911 | ||
e45b1be8 | 912 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
913 | /* choose the the oldest expectation to evict */ |
914 | list_for_each_entry_reverse(i, &ip_conntrack_expect_list, list) { | |
915 | if (expect_matches(i, exp) && del_timer(&i->timeout)) { | |
49719eb3 | 916 | ip_ct_unlink_expect(i); |
e45b1be8 | 917 | write_unlock_bh(&ip_conntrack_lock); |
4acdbdbe | 918 | ip_conntrack_expect_put(i); |
1da177e4 LT |
919 | return; |
920 | } | |
921 | } | |
e45b1be8 | 922 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
923 | } |
924 | ||
91c46e2e PNA |
925 | /* We don't increase the master conntrack refcount for non-fulfilled |
926 | * conntracks. During the conntrack destruction, the expectations are | |
927 | * always killed before the conntrack itself */ | |
4acdbdbe | 928 | struct ip_conntrack_expect *ip_conntrack_expect_alloc(struct ip_conntrack *me) |
1da177e4 LT |
929 | { |
930 | struct ip_conntrack_expect *new; | |
931 | ||
932 | new = kmem_cache_alloc(ip_conntrack_expect_cachep, GFP_ATOMIC); | |
933 | if (!new) { | |
934 | DEBUGP("expect_related: OOM allocating expect\n"); | |
935 | return NULL; | |
936 | } | |
4acdbdbe | 937 | new->master = me; |
4acdbdbe | 938 | atomic_set(&new->use, 1); |
1da177e4 LT |
939 | return new; |
940 | } | |
941 | ||
4acdbdbe | 942 | void ip_conntrack_expect_put(struct ip_conntrack_expect *exp) |
1da177e4 | 943 | { |
91c46e2e | 944 | if (atomic_dec_and_test(&exp->use)) |
4acdbdbe | 945 | kmem_cache_free(ip_conntrack_expect_cachep, exp); |
1da177e4 LT |
946 | } |
947 | ||
948 | static void ip_conntrack_expect_insert(struct ip_conntrack_expect *exp) | |
949 | { | |
4acdbdbe | 950 | atomic_inc(&exp->use); |
1da177e4 LT |
951 | exp->master->expecting++; |
952 | list_add(&exp->list, &ip_conntrack_expect_list); | |
953 | ||
1d3cdb41 PO |
954 | init_timer(&exp->timeout); |
955 | exp->timeout.data = (unsigned long)exp; | |
956 | exp->timeout.function = expectation_timed_out; | |
957 | exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ; | |
958 | add_timer(&exp->timeout); | |
1da177e4 | 959 | |
080774a2 HW |
960 | exp->id = ++ip_conntrack_expect_next_id; |
961 | atomic_inc(&exp->use); | |
1da177e4 LT |
962 | CONNTRACK_STAT_INC(expect_create); |
963 | } | |
964 | ||
965 | /* Race with expectations being used means we could have none to find; OK. */ | |
966 | static void evict_oldest_expect(struct ip_conntrack *master) | |
967 | { | |
968 | struct ip_conntrack_expect *i; | |
969 | ||
970 | list_for_each_entry_reverse(i, &ip_conntrack_expect_list, list) { | |
971 | if (i->master == master) { | |
972 | if (del_timer(&i->timeout)) { | |
49719eb3 | 973 | ip_ct_unlink_expect(i); |
4acdbdbe | 974 | ip_conntrack_expect_put(i); |
1da177e4 LT |
975 | } |
976 | break; | |
977 | } | |
978 | } | |
979 | } | |
980 | ||
981 | static inline int refresh_timer(struct ip_conntrack_expect *i) | |
982 | { | |
983 | if (!del_timer(&i->timeout)) | |
984 | return 0; | |
985 | ||
986 | i->timeout.expires = jiffies + i->master->helper->timeout*HZ; | |
987 | add_timer(&i->timeout); | |
988 | return 1; | |
989 | } | |
990 | ||
991 | int ip_conntrack_expect_related(struct ip_conntrack_expect *expect) | |
992 | { | |
993 | struct ip_conntrack_expect *i; | |
994 | int ret; | |
995 | ||
996 | DEBUGP("ip_conntrack_expect_related %p\n", related_to); | |
997 | DEBUGP("tuple: "); DUMP_TUPLE(&expect->tuple); | |
998 | DEBUGP("mask: "); DUMP_TUPLE(&expect->mask); | |
999 | ||
e45b1be8 | 1000 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1001 | list_for_each_entry(i, &ip_conntrack_expect_list, list) { |
1002 | if (expect_matches(i, expect)) { | |
1003 | /* Refresh timer: if it's dying, ignore.. */ | |
1004 | if (refresh_timer(i)) { | |
1005 | ret = 0; | |
1da177e4 LT |
1006 | goto out; |
1007 | } | |
1008 | } else if (expect_clash(i, expect)) { | |
1009 | ret = -EBUSY; | |
1010 | goto out; | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | /* Will be over limit? */ | |
1015 | if (expect->master->helper->max_expected && | |
1016 | expect->master->expecting >= expect->master->helper->max_expected) | |
1017 | evict_oldest_expect(expect->master); | |
1018 | ||
1019 | ip_conntrack_expect_insert(expect); | |
ac3247ba | 1020 | ip_conntrack_expect_event(IPEXP_NEW, expect); |
1da177e4 LT |
1021 | ret = 0; |
1022 | out: | |
e45b1be8 | 1023 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1024 | return ret; |
1025 | } | |
1026 | ||
1027 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is | |
1028 | implicitly racy: see __ip_conntrack_confirm */ | |
1029 | void ip_conntrack_alter_reply(struct ip_conntrack *conntrack, | |
1030 | const struct ip_conntrack_tuple *newreply) | |
1031 | { | |
e45b1be8 | 1032 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1033 | /* Should be unconfirmed, so not in hash table yet */ |
1034 | IP_NF_ASSERT(!is_confirmed(conntrack)); | |
1035 | ||
1036 | DEBUGP("Altering reply tuple of %p to ", conntrack); | |
1037 | DUMP_TUPLE(newreply); | |
1038 | ||
1039 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; | |
1040 | if (!conntrack->master && conntrack->expecting == 0) | |
080774a2 | 1041 | conntrack->helper = __ip_conntrack_helper_find(newreply); |
e45b1be8 | 1042 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1043 | } |
1044 | ||
1045 | int ip_conntrack_helper_register(struct ip_conntrack_helper *me) | |
1046 | { | |
1047 | BUG_ON(me->timeout == 0); | |
e45b1be8 | 1048 | write_lock_bh(&ip_conntrack_lock); |
df0933dc | 1049 | list_add(&me->list, &helpers); |
e45b1be8 | 1050 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1051 | |
1052 | return 0; | |
1053 | } | |
1054 | ||
080774a2 HW |
1055 | struct ip_conntrack_helper * |
1056 | __ip_conntrack_helper_find_byname(const char *name) | |
1057 | { | |
1058 | struct ip_conntrack_helper *h; | |
1059 | ||
1060 | list_for_each_entry(h, &helpers, list) { | |
1061 | if (!strcmp(h->name, name)) | |
1062 | return h; | |
1063 | } | |
1064 | ||
1065 | return NULL; | |
1066 | } | |
1067 | ||
df0933dc PM |
1068 | static inline void unhelp(struct ip_conntrack_tuple_hash *i, |
1069 | const struct ip_conntrack_helper *me) | |
1da177e4 | 1070 | { |
ac3247ba HW |
1071 | if (tuplehash_to_ctrack(i)->helper == me) { |
1072 | ip_conntrack_event(IPCT_HELPER, tuplehash_to_ctrack(i)); | |
1da177e4 | 1073 | tuplehash_to_ctrack(i)->helper = NULL; |
ac3247ba | 1074 | } |
1da177e4 LT |
1075 | } |
1076 | ||
1077 | void ip_conntrack_helper_unregister(struct ip_conntrack_helper *me) | |
1078 | { | |
1079 | unsigned int i; | |
df0933dc | 1080 | struct ip_conntrack_tuple_hash *h; |
1da177e4 LT |
1081 | struct ip_conntrack_expect *exp, *tmp; |
1082 | ||
1083 | /* Need write lock here, to delete helper. */ | |
e45b1be8 | 1084 | write_lock_bh(&ip_conntrack_lock); |
df0933dc | 1085 | list_del(&me->list); |
1da177e4 LT |
1086 | |
1087 | /* Get rid of expectations */ | |
1088 | list_for_each_entry_safe(exp, tmp, &ip_conntrack_expect_list, list) { | |
1089 | if (exp->master->helper == me && del_timer(&exp->timeout)) { | |
49719eb3 | 1090 | ip_ct_unlink_expect(exp); |
4acdbdbe | 1091 | ip_conntrack_expect_put(exp); |
1da177e4 LT |
1092 | } |
1093 | } | |
1094 | /* Get rid of expecteds, set helpers to NULL. */ | |
df0933dc PM |
1095 | list_for_each_entry(h, &unconfirmed, list) |
1096 | unhelp(h, me); | |
1097 | for (i = 0; i < ip_conntrack_htable_size; i++) { | |
1098 | list_for_each_entry(h, &ip_conntrack_hash[i], list) | |
1099 | unhelp(h, me); | |
1100 | } | |
e45b1be8 | 1101 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1102 | |
1103 | /* Someone could be still looking at the helper in a bh. */ | |
1104 | synchronize_net(); | |
1105 | } | |
1106 | ||
1dfbab59 HW |
1107 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ |
1108 | void __ip_ct_refresh_acct(struct ip_conntrack *ct, | |
1da177e4 LT |
1109 | enum ip_conntrack_info ctinfo, |
1110 | const struct sk_buff *skb, | |
1dfbab59 HW |
1111 | unsigned long extra_jiffies, |
1112 | int do_acct) | |
1da177e4 | 1113 | { |
a051a8f7 | 1114 | int event = 0; |
1dfbab59 | 1115 | |
1da177e4 | 1116 | IP_NF_ASSERT(ct->timeout.data == (unsigned long)ct); |
1dfbab59 HW |
1117 | IP_NF_ASSERT(skb); |
1118 | ||
1119 | write_lock_bh(&ip_conntrack_lock); | |
1da177e4 | 1120 | |
997ae831 EL |
1121 | /* Only update if this is not a fixed timeout */ |
1122 | if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { | |
1123 | write_unlock_bh(&ip_conntrack_lock); | |
1124 | return; | |
1125 | } | |
1126 | ||
1da177e4 LT |
1127 | /* If not in hash table, timer will not be active yet */ |
1128 | if (!is_confirmed(ct)) { | |
1129 | ct->timeout.expires = extra_jiffies; | |
a051a8f7 | 1130 | event = IPCT_REFRESH; |
1da177e4 | 1131 | } else { |
1da177e4 LT |
1132 | /* Need del_timer for race avoidance (may already be dying). */ |
1133 | if (del_timer(&ct->timeout)) { | |
1134 | ct->timeout.expires = jiffies + extra_jiffies; | |
1135 | add_timer(&ct->timeout); | |
a051a8f7 | 1136 | event = IPCT_REFRESH; |
1da177e4 | 1137 | } |
1da177e4 | 1138 | } |
1dfbab59 HW |
1139 | |
1140 | #ifdef CONFIG_IP_NF_CT_ACCT | |
1141 | if (do_acct) { | |
1142 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
1143 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
1144 | ntohs(skb->nh.iph->tot_len); | |
a051a8f7 HW |
1145 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) |
1146 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
1147 | event |= IPCT_COUNTER_FILLING; | |
1dfbab59 HW |
1148 | } |
1149 | #endif | |
1150 | ||
1151 | write_unlock_bh(&ip_conntrack_lock); | |
1152 | ||
1153 | /* must be unlocked when calling event cache */ | |
a051a8f7 HW |
1154 | if (event) |
1155 | ip_conntrack_event_cache(event, skb); | |
1da177e4 LT |
1156 | } |
1157 | ||
080774a2 HW |
1158 | #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \ |
1159 | defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE) | |
1160 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
1161 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
1162 | * or depend on ctnetlink */ | |
1163 | int ip_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
1164 | const struct ip_conntrack_tuple *tuple) | |
1165 | { | |
cdcb71bf | 1166 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(__be16), |
080774a2 | 1167 | &tuple->src.u.tcp.port); |
cdcb71bf | 1168 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(__be16), |
080774a2 HW |
1169 | &tuple->dst.u.tcp.port); |
1170 | return 0; | |
1171 | ||
1172 | nfattr_failure: | |
1173 | return -1; | |
1174 | } | |
1175 | ||
1176 | int ip_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
1177 | struct ip_conntrack_tuple *t) | |
1178 | { | |
1179 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
1180 | return -EINVAL; | |
1181 | ||
1182 | t->src.u.tcp.port = | |
cdcb71bf | 1183 | *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); |
080774a2 | 1184 | t->dst.u.tcp.port = |
cdcb71bf | 1185 | *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); |
080774a2 HW |
1186 | |
1187 | return 0; | |
1188 | } | |
1189 | #endif | |
1190 | ||
1da177e4 LT |
1191 | /* Returns new sk_buff, or NULL */ |
1192 | struct sk_buff * | |
1193 | ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user) | |
1194 | { | |
8be58932 | 1195 | skb_orphan(skb); |
1da177e4 LT |
1196 | |
1197 | local_bh_disable(); | |
1198 | skb = ip_defrag(skb, user); | |
1199 | local_bh_enable(); | |
1200 | ||
6869c4d8 | 1201 | if (skb) |
8be58932 | 1202 | ip_send_check(skb->nh.iph); |
1da177e4 LT |
1203 | return skb; |
1204 | } | |
1205 | ||
1206 | /* Used by ipt_REJECT. */ | |
1207 | static void ip_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
1208 | { | |
1209 | struct ip_conntrack *ct; | |
1210 | enum ip_conntrack_info ctinfo; | |
1211 | ||
1212 | /* This ICMP is in reverse direction to the packet which caused it */ | |
1213 | ct = ip_conntrack_get(skb, &ctinfo); | |
1214 | ||
1215 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
1216 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
1217 | else | |
1218 | ctinfo = IP_CT_RELATED; | |
1219 | ||
1220 | /* Attach to new skbuff, and increment count */ | |
1221 | nskb->nfct = &ct->ct_general; | |
1222 | nskb->nfctinfo = ctinfo; | |
1223 | nf_conntrack_get(nskb->nfct); | |
1224 | } | |
1225 | ||
1da177e4 | 1226 | /* Bring out ya dead! */ |
df0933dc | 1227 | static struct ip_conntrack * |
1da177e4 LT |
1228 | get_next_corpse(int (*iter)(struct ip_conntrack *i, void *data), |
1229 | void *data, unsigned int *bucket) | |
1230 | { | |
df0933dc PM |
1231 | struct ip_conntrack_tuple_hash *h; |
1232 | struct ip_conntrack *ct; | |
1da177e4 | 1233 | |
e45b1be8 | 1234 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 | 1235 | for (; *bucket < ip_conntrack_htable_size; (*bucket)++) { |
df0933dc PM |
1236 | list_for_each_entry(h, &ip_conntrack_hash[*bucket], list) { |
1237 | ct = tuplehash_to_ctrack(h); | |
1238 | if (iter(ct, data)) | |
1239 | goto found; | |
1240 | } | |
1241 | } | |
1242 | list_for_each_entry(h, &unconfirmed, list) { | |
1243 | ct = tuplehash_to_ctrack(h); | |
1244 | if (iter(ct, data)) | |
1245 | goto found; | |
1da177e4 | 1246 | } |
e45b1be8 | 1247 | write_unlock_bh(&ip_conntrack_lock); |
df0933dc | 1248 | return NULL; |
1da177e4 | 1249 | |
df0933dc PM |
1250 | found: |
1251 | atomic_inc(&ct->ct_general.use); | |
1252 | write_unlock_bh(&ip_conntrack_lock); | |
1253 | return ct; | |
1da177e4 LT |
1254 | } |
1255 | ||
1256 | void | |
1257 | ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *), void *data) | |
1258 | { | |
df0933dc | 1259 | struct ip_conntrack *ct; |
1da177e4 LT |
1260 | unsigned int bucket = 0; |
1261 | ||
df0933dc | 1262 | while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { |
1da177e4 LT |
1263 | /* Time to push up daises... */ |
1264 | if (del_timer(&ct->timeout)) | |
1265 | death_by_timeout((unsigned long)ct); | |
1266 | /* ... else the timer will get him soon. */ | |
1267 | ||
1268 | ip_conntrack_put(ct); | |
1269 | } | |
1270 | } | |
1271 | ||
1272 | /* Fast function for those who don't want to parse /proc (and I don't | |
1273 | blame them). */ | |
1274 | /* Reversing the socket's dst/src point of view gives us the reply | |
1275 | mapping. */ | |
1276 | static int | |
1277 | getorigdst(struct sock *sk, int optval, void __user *user, int *len) | |
1278 | { | |
1279 | struct inet_sock *inet = inet_sk(sk); | |
1280 | struct ip_conntrack_tuple_hash *h; | |
1281 | struct ip_conntrack_tuple tuple; | |
1282 | ||
1283 | IP_CT_TUPLE_U_BLANK(&tuple); | |
1284 | tuple.src.ip = inet->rcv_saddr; | |
1285 | tuple.src.u.tcp.port = inet->sport; | |
1286 | tuple.dst.ip = inet->daddr; | |
1287 | tuple.dst.u.tcp.port = inet->dport; | |
1288 | tuple.dst.protonum = IPPROTO_TCP; | |
1289 | ||
1290 | /* We only do TCP at the moment: is there a better way? */ | |
1291 | if (strcmp(sk->sk_prot->name, "TCP")) { | |
1292 | DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n"); | |
1293 | return -ENOPROTOOPT; | |
1294 | } | |
1295 | ||
1296 | if ((unsigned int) *len < sizeof(struct sockaddr_in)) { | |
1297 | DEBUGP("SO_ORIGINAL_DST: len %u not %u\n", | |
1298 | *len, sizeof(struct sockaddr_in)); | |
1299 | return -EINVAL; | |
1300 | } | |
1301 | ||
1302 | h = ip_conntrack_find_get(&tuple, NULL); | |
1303 | if (h) { | |
1304 | struct sockaddr_in sin; | |
1305 | struct ip_conntrack *ct = tuplehash_to_ctrack(h); | |
1306 | ||
1307 | sin.sin_family = AF_INET; | |
1308 | sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL] | |
1309 | .tuple.dst.u.tcp.port; | |
1310 | sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL] | |
1311 | .tuple.dst.ip; | |
6c813c3f | 1312 | memset(sin.sin_zero, 0, sizeof(sin.sin_zero)); |
1da177e4 LT |
1313 | |
1314 | DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n", | |
1315 | NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port)); | |
1316 | ip_conntrack_put(ct); | |
1317 | if (copy_to_user(user, &sin, sizeof(sin)) != 0) | |
1318 | return -EFAULT; | |
1319 | else | |
1320 | return 0; | |
1321 | } | |
1322 | DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n", | |
1323 | NIPQUAD(tuple.src.ip), ntohs(tuple.src.u.tcp.port), | |
1324 | NIPQUAD(tuple.dst.ip), ntohs(tuple.dst.u.tcp.port)); | |
1325 | return -ENOENT; | |
1326 | } | |
1327 | ||
1328 | static struct nf_sockopt_ops so_getorigdst = { | |
1329 | .pf = PF_INET, | |
1330 | .get_optmin = SO_ORIGINAL_DST, | |
1331 | .get_optmax = SO_ORIGINAL_DST+1, | |
1332 | .get = &getorigdst, | |
1333 | }; | |
1334 | ||
1335 | static int kill_all(struct ip_conntrack *i, void *data) | |
1336 | { | |
1337 | return 1; | |
1338 | } | |
1339 | ||
afe5c6bb PM |
1340 | void ip_conntrack_flush(void) |
1341 | { | |
1342 | ip_ct_iterate_cleanup(kill_all, NULL); | |
1343 | } | |
1344 | ||
eed75f19 | 1345 | static void free_conntrack_hash(struct list_head *hash, int vmalloced,int size) |
1da177e4 | 1346 | { |
eed75f19 HW |
1347 | if (vmalloced) |
1348 | vfree(hash); | |
1da177e4 | 1349 | else |
eed75f19 HW |
1350 | free_pages((unsigned long)hash, |
1351 | get_order(sizeof(struct list_head) * size)); | |
1da177e4 LT |
1352 | } |
1353 | ||
afe5c6bb PM |
1354 | /* Mishearing the voices in his head, our hero wonders how he's |
1355 | supposed to kill the mall. */ | |
1356 | void ip_conntrack_cleanup(void) | |
1da177e4 | 1357 | { |
afe5c6bb PM |
1358 | ip_ct_attach = NULL; |
1359 | ||
1da177e4 LT |
1360 | /* This makes sure all current packets have passed through |
1361 | netfilter framework. Roll on, two-stage module | |
1362 | delete... */ | |
1363 | synchronize_net(); | |
080774a2 | 1364 | |
a86888b9 | 1365 | ip_ct_event_cache_flush(); |
1da177e4 | 1366 | i_see_dead_people: |
afe5c6bb | 1367 | ip_conntrack_flush(); |
1da177e4 LT |
1368 | if (atomic_read(&ip_conntrack_count) != 0) { |
1369 | schedule(); | |
1370 | goto i_see_dead_people; | |
1371 | } | |
21f930e4 PM |
1372 | /* wait until all references to ip_conntrack_untracked are dropped */ |
1373 | while (atomic_read(&ip_conntrack_untracked.ct_general.use) > 1) | |
1374 | schedule(); | |
1da177e4 LT |
1375 | |
1376 | kmem_cache_destroy(ip_conntrack_cachep); | |
1377 | kmem_cache_destroy(ip_conntrack_expect_cachep); | |
eed75f19 HW |
1378 | free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc, |
1379 | ip_conntrack_htable_size); | |
1da177e4 LT |
1380 | nf_unregister_sockopt(&so_getorigdst); |
1381 | } | |
1382 | ||
eed75f19 HW |
1383 | static struct list_head *alloc_hashtable(int size, int *vmalloced) |
1384 | { | |
1385 | struct list_head *hash; | |
1386 | unsigned int i; | |
1387 | ||
1388 | *vmalloced = 0; | |
1389 | hash = (void*)__get_free_pages(GFP_KERNEL, | |
1390 | get_order(sizeof(struct list_head) | |
1391 | * size)); | |
1392 | if (!hash) { | |
1393 | *vmalloced = 1; | |
1394 | printk(KERN_WARNING"ip_conntrack: falling back to vmalloc.\n"); | |
1395 | hash = vmalloc(sizeof(struct list_head) * size); | |
1396 | } | |
1397 | ||
1398 | if (hash) | |
1399 | for (i = 0; i < size; i++) | |
1400 | INIT_LIST_HEAD(&hash[i]); | |
1401 | ||
1402 | return hash; | |
1403 | } | |
1404 | ||
d127e94a | 1405 | static int set_hashsize(const char *val, struct kernel_param *kp) |
eed75f19 HW |
1406 | { |
1407 | int i, bucket, hashsize, vmalloced; | |
1408 | int old_vmalloced, old_size; | |
1409 | int rnd; | |
1410 | struct list_head *hash, *old_hash; | |
1411 | struct ip_conntrack_tuple_hash *h; | |
1412 | ||
1413 | /* On boot, we can set this without any fancy locking. */ | |
1414 | if (!ip_conntrack_htable_size) | |
1415 | return param_set_int(val, kp); | |
1416 | ||
1417 | hashsize = simple_strtol(val, NULL, 0); | |
1418 | if (!hashsize) | |
1419 | return -EINVAL; | |
1420 | ||
1421 | hash = alloc_hashtable(hashsize, &vmalloced); | |
1422 | if (!hash) | |
1423 | return -ENOMEM; | |
1424 | ||
1425 | /* We have to rehash for the new table anyway, so we also can | |
1426 | * use a new random seed */ | |
1427 | get_random_bytes(&rnd, 4); | |
1428 | ||
1429 | write_lock_bh(&ip_conntrack_lock); | |
1430 | for (i = 0; i < ip_conntrack_htable_size; i++) { | |
1431 | while (!list_empty(&ip_conntrack_hash[i])) { | |
1432 | h = list_entry(ip_conntrack_hash[i].next, | |
1433 | struct ip_conntrack_tuple_hash, list); | |
1434 | list_del(&h->list); | |
1435 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); | |
1436 | list_add_tail(&h->list, &hash[bucket]); | |
1437 | } | |
1438 | } | |
1439 | old_size = ip_conntrack_htable_size; | |
1440 | old_vmalloced = ip_conntrack_vmalloc; | |
1441 | old_hash = ip_conntrack_hash; | |
1442 | ||
1443 | ip_conntrack_htable_size = hashsize; | |
1444 | ip_conntrack_vmalloc = vmalloced; | |
1445 | ip_conntrack_hash = hash; | |
1446 | ip_conntrack_hash_rnd = rnd; | |
1447 | write_unlock_bh(&ip_conntrack_lock); | |
1448 | ||
1449 | free_conntrack_hash(old_hash, old_vmalloced, old_size); | |
1450 | return 0; | |
1451 | } | |
1452 | ||
1453 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1454 | &ip_conntrack_htable_size, 0600); | |
1da177e4 LT |
1455 | |
1456 | int __init ip_conntrack_init(void) | |
1457 | { | |
1458 | unsigned int i; | |
1459 | int ret; | |
1460 | ||
1461 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
1462 | * machine has 256 buckets. >= 1GB machines have 8192 buckets. */ | |
eed75f19 | 1463 | if (!ip_conntrack_htable_size) { |
1da177e4 LT |
1464 | ip_conntrack_htable_size |
1465 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
1466 | / sizeof(struct list_head)); | |
1467 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) | |
1468 | ip_conntrack_htable_size = 8192; | |
1469 | if (ip_conntrack_htable_size < 16) | |
1470 | ip_conntrack_htable_size = 16; | |
1471 | } | |
1472 | ip_conntrack_max = 8 * ip_conntrack_htable_size; | |
1473 | ||
1474 | printk("ip_conntrack version %s (%u buckets, %d max)" | |
1475 | " - %Zd bytes per conntrack\n", IP_CONNTRACK_VERSION, | |
1476 | ip_conntrack_htable_size, ip_conntrack_max, | |
1477 | sizeof(struct ip_conntrack)); | |
1478 | ||
1479 | ret = nf_register_sockopt(&so_getorigdst); | |
1480 | if (ret != 0) { | |
1481 | printk(KERN_ERR "Unable to register netfilter socket option\n"); | |
1482 | return ret; | |
1483 | } | |
1484 | ||
eed75f19 HW |
1485 | ip_conntrack_hash = alloc_hashtable(ip_conntrack_htable_size, |
1486 | &ip_conntrack_vmalloc); | |
1da177e4 LT |
1487 | if (!ip_conntrack_hash) { |
1488 | printk(KERN_ERR "Unable to create ip_conntrack_hash\n"); | |
1489 | goto err_unreg_sockopt; | |
1490 | } | |
1491 | ||
1492 | ip_conntrack_cachep = kmem_cache_create("ip_conntrack", | |
1493 | sizeof(struct ip_conntrack), 0, | |
1494 | 0, NULL, NULL); | |
1495 | if (!ip_conntrack_cachep) { | |
1496 | printk(KERN_ERR "Unable to create ip_conntrack slab cache\n"); | |
1497 | goto err_free_hash; | |
1498 | } | |
1499 | ||
1500 | ip_conntrack_expect_cachep = kmem_cache_create("ip_conntrack_expect", | |
1501 | sizeof(struct ip_conntrack_expect), | |
1502 | 0, 0, NULL, NULL); | |
1503 | if (!ip_conntrack_expect_cachep) { | |
1504 | printk(KERN_ERR "Unable to create ip_expect slab cache\n"); | |
1505 | goto err_free_conntrack_slab; | |
1506 | } | |
1507 | ||
1508 | /* Don't NEED lock here, but good form anyway. */ | |
e45b1be8 | 1509 | write_lock_bh(&ip_conntrack_lock); |
1da177e4 LT |
1510 | for (i = 0; i < MAX_IP_CT_PROTO; i++) |
1511 | ip_ct_protos[i] = &ip_conntrack_generic_protocol; | |
1512 | /* Sew in builtin protocols. */ | |
1513 | ip_ct_protos[IPPROTO_TCP] = &ip_conntrack_protocol_tcp; | |
1514 | ip_ct_protos[IPPROTO_UDP] = &ip_conntrack_protocol_udp; | |
1515 | ip_ct_protos[IPPROTO_ICMP] = &ip_conntrack_protocol_icmp; | |
e45b1be8 | 1516 | write_unlock_bh(&ip_conntrack_lock); |
1da177e4 | 1517 | |
1da177e4 LT |
1518 | /* For use by ipt_REJECT */ |
1519 | ip_ct_attach = ip_conntrack_attach; | |
1520 | ||
1521 | /* Set up fake conntrack: | |
1522 | - to never be deleted, not in any hashes */ | |
1523 | atomic_set(&ip_conntrack_untracked.ct_general.use, 1); | |
1524 | /* - and look it like as a confirmed connection */ | |
1525 | set_bit(IPS_CONFIRMED_BIT, &ip_conntrack_untracked.status); | |
1526 | ||
1527 | return ret; | |
1528 | ||
1529 | err_free_conntrack_slab: | |
1530 | kmem_cache_destroy(ip_conntrack_cachep); | |
1531 | err_free_hash: | |
eed75f19 HW |
1532 | free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc, |
1533 | ip_conntrack_htable_size); | |
1da177e4 LT |
1534 | err_unreg_sockopt: |
1535 | nf_unregister_sockopt(&so_getorigdst); | |
1536 | ||
1537 | return -ENOMEM; | |
1538 | } |