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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. | |
9fb9cbb1 YK |
12 | */ |
13 | ||
9fb9cbb1 YK |
14 | #include <linux/types.h> |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/proc_fs.h> | |
19 | #include <linux/vmalloc.h> | |
20 | #include <linux/stddef.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/random.h> | |
23 | #include <linux/jhash.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/percpu.h> | |
26 | #include <linux/moduleparam.h> | |
27 | #include <linux/notifier.h> | |
28 | #include <linux/kernel.h> | |
29 | #include <linux/netdevice.h> | |
30 | #include <linux/socket.h> | |
d7fe0f24 | 31 | #include <linux/mm.h> |
9fb9cbb1 | 32 | |
9fb9cbb1 YK |
33 | #include <net/netfilter/nf_conntrack.h> |
34 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
605dcad6 | 35 | #include <net/netfilter/nf_conntrack_l4proto.h> |
77ab9cff | 36 | #include <net/netfilter/nf_conntrack_expect.h> |
9fb9cbb1 YK |
37 | #include <net/netfilter/nf_conntrack_helper.h> |
38 | #include <net/netfilter/nf_conntrack_core.h> | |
ecfab2c9 | 39 | #include <net/netfilter/nf_conntrack_extend.h> |
9fb9cbb1 | 40 | |
dc808fe2 | 41 | #define NF_CONNTRACK_VERSION "0.5.0" |
9fb9cbb1 | 42 | |
9fb9cbb1 | 43 | DEFINE_RWLOCK(nf_conntrack_lock); |
13b18339 | 44 | EXPORT_SYMBOL_GPL(nf_conntrack_lock); |
9fb9cbb1 YK |
45 | |
46 | /* nf_conntrack_standalone needs this */ | |
47 | atomic_t nf_conntrack_count = ATOMIC_INIT(0); | |
a999e683 | 48 | EXPORT_SYMBOL_GPL(nf_conntrack_count); |
9fb9cbb1 | 49 | |
e2b7606c | 50 | unsigned int nf_conntrack_htable_size __read_mostly; |
13b18339 PM |
51 | EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); |
52 | ||
94aec08e | 53 | int nf_conntrack_max __read_mostly; |
a999e683 | 54 | EXPORT_SYMBOL_GPL(nf_conntrack_max); |
13b18339 | 55 | |
f205c5e0 | 56 | struct hlist_head *nf_conntrack_hash __read_mostly; |
13b18339 PM |
57 | EXPORT_SYMBOL_GPL(nf_conntrack_hash); |
58 | ||
e2b7606c | 59 | struct nf_conn nf_conntrack_untracked __read_mostly; |
13b18339 PM |
60 | EXPORT_SYMBOL_GPL(nf_conntrack_untracked); |
61 | ||
94aec08e | 62 | unsigned int nf_ct_log_invalid __read_mostly; |
f205c5e0 | 63 | HLIST_HEAD(unconfirmed); |
1192e403 | 64 | static int nf_conntrack_vmalloc __read_mostly; |
dacd2a1a | 65 | static struct kmem_cache *nf_conntrack_cachep __read_mostly; |
4e3882f7 | 66 | static unsigned int nf_conntrack_next_id; |
77ab9cff | 67 | |
9fb9cbb1 YK |
68 | DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); |
69 | EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); | |
70 | ||
9fb9cbb1 YK |
71 | static int nf_conntrack_hash_rnd_initted; |
72 | static unsigned int nf_conntrack_hash_rnd; | |
73 | ||
74 | static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, | |
75 | unsigned int size, unsigned int rnd) | |
76 | { | |
77 | unsigned int a, b; | |
9b887909 SF |
78 | |
79 | a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all), | |
80 | (tuple->src.l3num << 16) | tuple->dst.protonum); | |
81 | b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all), | |
82 | (tuple->src.u.all << 16) | tuple->dst.u.all); | |
9fb9cbb1 YK |
83 | |
84 | return jhash_2words(a, b, rnd) % size; | |
85 | } | |
86 | ||
87 | static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple) | |
88 | { | |
89 | return __hash_conntrack(tuple, nf_conntrack_htable_size, | |
90 | nf_conntrack_hash_rnd); | |
91 | } | |
92 | ||
9fb9cbb1 YK |
93 | int |
94 | nf_ct_get_tuple(const struct sk_buff *skb, | |
95 | unsigned int nhoff, | |
96 | unsigned int dataoff, | |
97 | u_int16_t l3num, | |
98 | u_int8_t protonum, | |
99 | struct nf_conntrack_tuple *tuple, | |
100 | const struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 101 | const struct nf_conntrack_l4proto *l4proto) |
9fb9cbb1 YK |
102 | { |
103 | NF_CT_TUPLE_U_BLANK(tuple); | |
104 | ||
105 | tuple->src.l3num = l3num; | |
106 | if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) | |
107 | return 0; | |
108 | ||
109 | tuple->dst.protonum = protonum; | |
110 | tuple->dst.dir = IP_CT_DIR_ORIGINAL; | |
111 | ||
605dcad6 | 112 | return l4proto->pkt_to_tuple(skb, dataoff, tuple); |
9fb9cbb1 | 113 | } |
13b18339 | 114 | EXPORT_SYMBOL_GPL(nf_ct_get_tuple); |
9fb9cbb1 YK |
115 | |
116 | int | |
117 | nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, | |
118 | const struct nf_conntrack_tuple *orig, | |
119 | const struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 120 | const struct nf_conntrack_l4proto *l4proto) |
9fb9cbb1 YK |
121 | { |
122 | NF_CT_TUPLE_U_BLANK(inverse); | |
123 | ||
124 | inverse->src.l3num = orig->src.l3num; | |
125 | if (l3proto->invert_tuple(inverse, orig) == 0) | |
126 | return 0; | |
127 | ||
128 | inverse->dst.dir = !orig->dst.dir; | |
129 | ||
130 | inverse->dst.protonum = orig->dst.protonum; | |
605dcad6 | 131 | return l4proto->invert_tuple(inverse, orig); |
9fb9cbb1 | 132 | } |
13b18339 | 133 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); |
9fb9cbb1 | 134 | |
9fb9cbb1 YK |
135 | static void |
136 | clean_from_lists(struct nf_conn *ct) | |
137 | { | |
0d53778e | 138 | pr_debug("clean_from_lists(%p)\n", ct); |
f205c5e0 PM |
139 | hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); |
140 | hlist_del(&ct->tuplehash[IP_CT_DIR_REPLY].hnode); | |
9fb9cbb1 YK |
141 | |
142 | /* Destroy all pending expectations */ | |
c1d10adb | 143 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
144 | } |
145 | ||
146 | static void | |
147 | destroy_conntrack(struct nf_conntrack *nfct) | |
148 | { | |
149 | struct nf_conn *ct = (struct nf_conn *)nfct; | |
605dcad6 | 150 | struct nf_conntrack_l4proto *l4proto; |
9fb9cbb1 | 151 | |
0d53778e | 152 | pr_debug("destroy_conntrack(%p)\n", ct); |
9fb9cbb1 YK |
153 | NF_CT_ASSERT(atomic_read(&nfct->use) == 0); |
154 | NF_CT_ASSERT(!timer_pending(&ct->timeout)); | |
155 | ||
156 | nf_conntrack_event(IPCT_DESTROY, ct); | |
157 | set_bit(IPS_DYING_BIT, &ct->status); | |
158 | ||
159 | /* To make sure we don't get any weird locking issues here: | |
160 | * destroy_conntrack() MUST NOT be called with a write lock | |
161 | * to nf_conntrack_lock!!! -HW */ | |
923f4902 | 162 | rcu_read_lock(); |
923f4902 PM |
163 | l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num, |
164 | ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum); | |
605dcad6 MJ |
165 | if (l4proto && l4proto->destroy) |
166 | l4proto->destroy(ct); | |
9fb9cbb1 | 167 | |
ecfab2c9 YK |
168 | nf_ct_ext_destroy(ct); |
169 | ||
982d9a9c | 170 | rcu_read_unlock(); |
9fb9cbb1 YK |
171 | |
172 | write_lock_bh(&nf_conntrack_lock); | |
173 | /* Expectations will have been removed in clean_from_lists, | |
174 | * except TFTP can create an expectation on the first packet, | |
175 | * before connection is in the list, so we need to clean here, | |
176 | * too. */ | |
c1d10adb | 177 | nf_ct_remove_expectations(ct); |
9fb9cbb1 YK |
178 | |
179 | /* We overload first tuple to link into unconfirmed list. */ | |
180 | if (!nf_ct_is_confirmed(ct)) { | |
f205c5e0 PM |
181 | BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode)); |
182 | hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); | |
9fb9cbb1 YK |
183 | } |
184 | ||
185 | NF_CT_STAT_INC(delete); | |
186 | write_unlock_bh(&nf_conntrack_lock); | |
187 | ||
188 | if (ct->master) | |
189 | nf_ct_put(ct->master); | |
190 | ||
0d53778e | 191 | pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct); |
9fb9cbb1 YK |
192 | nf_conntrack_free(ct); |
193 | } | |
194 | ||
195 | static void death_by_timeout(unsigned long ul_conntrack) | |
196 | { | |
197 | struct nf_conn *ct = (void *)ul_conntrack; | |
5397e97d | 198 | struct nf_conn_help *help = nfct_help(ct); |
3c158f7f | 199 | struct nf_conntrack_helper *helper; |
5397e97d | 200 | |
3c158f7f PM |
201 | if (help) { |
202 | rcu_read_lock(); | |
203 | helper = rcu_dereference(help->helper); | |
204 | if (helper && helper->destroy) | |
205 | helper->destroy(ct); | |
206 | rcu_read_unlock(); | |
207 | } | |
9fb9cbb1 YK |
208 | |
209 | write_lock_bh(&nf_conntrack_lock); | |
210 | /* Inside lock so preempt is disabled on module removal path. | |
211 | * Otherwise we can get spurious warnings. */ | |
212 | NF_CT_STAT_INC(delete_list); | |
213 | clean_from_lists(ct); | |
214 | write_unlock_bh(&nf_conntrack_lock); | |
215 | nf_ct_put(ct); | |
216 | } | |
217 | ||
c1d10adb | 218 | struct nf_conntrack_tuple_hash * |
9fb9cbb1 YK |
219 | __nf_conntrack_find(const struct nf_conntrack_tuple *tuple, |
220 | const struct nf_conn *ignored_conntrack) | |
221 | { | |
222 | struct nf_conntrack_tuple_hash *h; | |
f205c5e0 | 223 | struct hlist_node *n; |
9fb9cbb1 YK |
224 | unsigned int hash = hash_conntrack(tuple); |
225 | ||
f205c5e0 | 226 | hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) { |
df0933dc PM |
227 | if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && |
228 | nf_ct_tuple_equal(tuple, &h->tuple)) { | |
9fb9cbb1 YK |
229 | NF_CT_STAT_INC(found); |
230 | return h; | |
231 | } | |
232 | NF_CT_STAT_INC(searched); | |
233 | } | |
234 | ||
235 | return NULL; | |
236 | } | |
13b18339 | 237 | EXPORT_SYMBOL_GPL(__nf_conntrack_find); |
9fb9cbb1 YK |
238 | |
239 | /* Find a connection corresponding to a tuple. */ | |
240 | struct nf_conntrack_tuple_hash * | |
330f7db5 | 241 | nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple) |
9fb9cbb1 YK |
242 | { |
243 | struct nf_conntrack_tuple_hash *h; | |
244 | ||
245 | read_lock_bh(&nf_conntrack_lock); | |
330f7db5 | 246 | h = __nf_conntrack_find(tuple, NULL); |
9fb9cbb1 YK |
247 | if (h) |
248 | atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use); | |
249 | read_unlock_bh(&nf_conntrack_lock); | |
250 | ||
251 | return h; | |
252 | } | |
13b18339 | 253 | EXPORT_SYMBOL_GPL(nf_conntrack_find_get); |
9fb9cbb1 | 254 | |
c1d10adb PNA |
255 | static void __nf_conntrack_hash_insert(struct nf_conn *ct, |
256 | unsigned int hash, | |
601e68e1 | 257 | unsigned int repl_hash) |
c1d10adb PNA |
258 | { |
259 | ct->id = ++nf_conntrack_next_id; | |
f205c5e0 PM |
260 | hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, |
261 | &nf_conntrack_hash[hash]); | |
262 | hlist_add_head(&ct->tuplehash[IP_CT_DIR_REPLY].hnode, | |
263 | &nf_conntrack_hash[repl_hash]); | |
c1d10adb PNA |
264 | } |
265 | ||
266 | void nf_conntrack_hash_insert(struct nf_conn *ct) | |
267 | { | |
268 | unsigned int hash, repl_hash; | |
269 | ||
270 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
271 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
272 | ||
273 | write_lock_bh(&nf_conntrack_lock); | |
274 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
275 | write_unlock_bh(&nf_conntrack_lock); | |
276 | } | |
13b18339 | 277 | EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); |
c1d10adb | 278 | |
9fb9cbb1 YK |
279 | /* Confirm a connection given skb; places it in hash table */ |
280 | int | |
281 | __nf_conntrack_confirm(struct sk_buff **pskb) | |
282 | { | |
283 | unsigned int hash, repl_hash; | |
df0933dc | 284 | struct nf_conntrack_tuple_hash *h; |
9fb9cbb1 | 285 | struct nf_conn *ct; |
df0933dc | 286 | struct nf_conn_help *help; |
f205c5e0 | 287 | struct hlist_node *n; |
9fb9cbb1 YK |
288 | enum ip_conntrack_info ctinfo; |
289 | ||
290 | ct = nf_ct_get(*pskb, &ctinfo); | |
291 | ||
292 | /* ipt_REJECT uses nf_conntrack_attach to attach related | |
293 | ICMP/TCP RST packets in other direction. Actual packet | |
294 | which created connection will be IP_CT_NEW or for an | |
295 | expected connection, IP_CT_RELATED. */ | |
296 | if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) | |
297 | return NF_ACCEPT; | |
298 | ||
299 | hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
300 | repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
301 | ||
302 | /* We're not in hash table, and we refuse to set up related | |
303 | connections for unconfirmed conns. But packet copies and | |
304 | REJECT will give spurious warnings here. */ | |
305 | /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ | |
306 | ||
307 | /* No external references means noone else could have | |
308 | confirmed us. */ | |
309 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
0d53778e | 310 | pr_debug("Confirming conntrack %p\n", ct); |
9fb9cbb1 YK |
311 | |
312 | write_lock_bh(&nf_conntrack_lock); | |
313 | ||
314 | /* See if there's one in the list already, including reverse: | |
315 | NAT could have grabbed it without realizing, since we're | |
316 | not in the hash. If there is, we lost race. */ | |
f205c5e0 | 317 | hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) |
df0933dc PM |
318 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, |
319 | &h->tuple)) | |
320 | goto out; | |
f205c5e0 | 321 | hlist_for_each_entry(h, n, &nf_conntrack_hash[repl_hash], hnode) |
df0933dc PM |
322 | if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, |
323 | &h->tuple)) | |
324 | goto out; | |
9fb9cbb1 | 325 | |
df0933dc | 326 | /* Remove from unconfirmed list */ |
f205c5e0 | 327 | hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); |
df0933dc PM |
328 | |
329 | __nf_conntrack_hash_insert(ct, hash, repl_hash); | |
330 | /* Timer relative to confirmation time, not original | |
331 | setting time, otherwise we'd get timer wrap in | |
332 | weird delay cases. */ | |
333 | ct->timeout.expires += jiffies; | |
334 | add_timer(&ct->timeout); | |
335 | atomic_inc(&ct->ct_general.use); | |
336 | set_bit(IPS_CONFIRMED_BIT, &ct->status); | |
337 | NF_CT_STAT_INC(insert); | |
338 | write_unlock_bh(&nf_conntrack_lock); | |
339 | help = nfct_help(ct); | |
340 | if (help && help->helper) | |
341 | nf_conntrack_event_cache(IPCT_HELPER, *pskb); | |
9fb9cbb1 | 342 | #ifdef CONFIG_NF_NAT_NEEDED |
df0933dc PM |
343 | if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) || |
344 | test_bit(IPS_DST_NAT_DONE_BIT, &ct->status)) | |
345 | nf_conntrack_event_cache(IPCT_NATINFO, *pskb); | |
9fb9cbb1 | 346 | #endif |
df0933dc PM |
347 | nf_conntrack_event_cache(master_ct(ct) ? |
348 | IPCT_RELATED : IPCT_NEW, *pskb); | |
349 | return NF_ACCEPT; | |
9fb9cbb1 | 350 | |
df0933dc | 351 | out: |
9fb9cbb1 YK |
352 | NF_CT_STAT_INC(insert_failed); |
353 | write_unlock_bh(&nf_conntrack_lock); | |
354 | return NF_DROP; | |
355 | } | |
13b18339 | 356 | EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); |
9fb9cbb1 YK |
357 | |
358 | /* Returns true if a connection correspondings to the tuple (required | |
359 | for NAT). */ | |
360 | int | |
361 | nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, | |
362 | const struct nf_conn *ignored_conntrack) | |
363 | { | |
364 | struct nf_conntrack_tuple_hash *h; | |
365 | ||
366 | read_lock_bh(&nf_conntrack_lock); | |
367 | h = __nf_conntrack_find(tuple, ignored_conntrack); | |
368 | read_unlock_bh(&nf_conntrack_lock); | |
369 | ||
370 | return h != NULL; | |
371 | } | |
13b18339 | 372 | EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); |
9fb9cbb1 | 373 | |
7ae7730f PM |
374 | #define NF_CT_EVICTION_RANGE 8 |
375 | ||
9fb9cbb1 YK |
376 | /* There's a small race here where we may free a just-assured |
377 | connection. Too bad: we're in trouble anyway. */ | |
7ae7730f | 378 | static int early_drop(unsigned int hash) |
9fb9cbb1 | 379 | { |
f205c5e0 | 380 | /* Use oldest entry, which is roughly LRU */ |
9fb9cbb1 | 381 | struct nf_conntrack_tuple_hash *h; |
df0933dc | 382 | struct nf_conn *ct = NULL, *tmp; |
f205c5e0 | 383 | struct hlist_node *n; |
7ae7730f | 384 | unsigned int i, cnt = 0; |
9fb9cbb1 YK |
385 | int dropped = 0; |
386 | ||
387 | read_lock_bh(&nf_conntrack_lock); | |
7ae7730f PM |
388 | for (i = 0; i < nf_conntrack_htable_size; i++) { |
389 | hlist_for_each_entry(h, n, &nf_conntrack_hash[hash], hnode) { | |
390 | tmp = nf_ct_tuplehash_to_ctrack(h); | |
391 | if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) | |
392 | ct = tmp; | |
393 | cnt++; | |
394 | } | |
395 | if (ct || cnt >= NF_CT_EVICTION_RANGE) | |
396 | break; | |
397 | hash = (hash + 1) % nf_conntrack_htable_size; | |
9fb9cbb1 | 398 | } |
f205c5e0 PM |
399 | if (ct) |
400 | atomic_inc(&ct->ct_general.use); | |
9fb9cbb1 YK |
401 | read_unlock_bh(&nf_conntrack_lock); |
402 | ||
403 | if (!ct) | |
404 | return dropped; | |
405 | ||
406 | if (del_timer(&ct->timeout)) { | |
407 | death_by_timeout((unsigned long)ct); | |
408 | dropped = 1; | |
c0e912d7 | 409 | NF_CT_STAT_INC_ATOMIC(early_drop); |
9fb9cbb1 YK |
410 | } |
411 | nf_ct_put(ct); | |
412 | return dropped; | |
413 | } | |
414 | ||
dacd2a1a YK |
415 | struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, |
416 | const struct nf_conntrack_tuple *repl) | |
9fb9cbb1 YK |
417 | { |
418 | struct nf_conn *conntrack = NULL; | |
9fb9cbb1 | 419 | |
dc808fe2 | 420 | if (unlikely(!nf_conntrack_hash_rnd_initted)) { |
9fb9cbb1 YK |
421 | get_random_bytes(&nf_conntrack_hash_rnd, 4); |
422 | nf_conntrack_hash_rnd_initted = 1; | |
423 | } | |
424 | ||
5251e2d2 PNA |
425 | /* We don't want any race condition at early drop stage */ |
426 | atomic_inc(&nf_conntrack_count); | |
427 | ||
9fb9cbb1 | 428 | if (nf_conntrack_max |
5251e2d2 | 429 | && atomic_read(&nf_conntrack_count) > nf_conntrack_max) { |
9fb9cbb1 | 430 | unsigned int hash = hash_conntrack(orig); |
7ae7730f | 431 | if (!early_drop(hash)) { |
5251e2d2 | 432 | atomic_dec(&nf_conntrack_count); |
9fb9cbb1 YK |
433 | if (net_ratelimit()) |
434 | printk(KERN_WARNING | |
435 | "nf_conntrack: table full, dropping" | |
436 | " packet.\n"); | |
437 | return ERR_PTR(-ENOMEM); | |
438 | } | |
439 | } | |
440 | ||
dacd2a1a | 441 | conntrack = kmem_cache_zalloc(nf_conntrack_cachep, GFP_ATOMIC); |
9fb9cbb1 | 442 | if (conntrack == NULL) { |
0d53778e | 443 | pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n"); |
dacd2a1a YK |
444 | atomic_dec(&nf_conntrack_count); |
445 | return ERR_PTR(-ENOMEM); | |
9fb9cbb1 YK |
446 | } |
447 | ||
9fb9cbb1 | 448 | atomic_set(&conntrack->ct_general.use, 1); |
9fb9cbb1 YK |
449 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; |
450 | conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; | |
451 | /* Don't set timer yet: wait for confirmation */ | |
e6f689db PM |
452 | setup_timer(&conntrack->timeout, death_by_timeout, |
453 | (unsigned long)conntrack); | |
9fb9cbb1 | 454 | |
9fb9cbb1 YK |
455 | return conntrack; |
456 | } | |
13b18339 | 457 | EXPORT_SYMBOL_GPL(nf_conntrack_alloc); |
9fb9cbb1 YK |
458 | |
459 | void nf_conntrack_free(struct nf_conn *conntrack) | |
460 | { | |
ecfab2c9 | 461 | nf_ct_ext_free(conntrack); |
dacd2a1a | 462 | kmem_cache_free(nf_conntrack_cachep, conntrack); |
9fb9cbb1 YK |
463 | atomic_dec(&nf_conntrack_count); |
464 | } | |
13b18339 | 465 | EXPORT_SYMBOL_GPL(nf_conntrack_free); |
9fb9cbb1 YK |
466 | |
467 | /* Allocate a new conntrack: we return -ENOMEM if classification | |
468 | failed due to stress. Otherwise it really is unclassifiable. */ | |
469 | static struct nf_conntrack_tuple_hash * | |
470 | init_conntrack(const struct nf_conntrack_tuple *tuple, | |
471 | struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 472 | struct nf_conntrack_l4proto *l4proto, |
9fb9cbb1 YK |
473 | struct sk_buff *skb, |
474 | unsigned int dataoff) | |
475 | { | |
476 | struct nf_conn *conntrack; | |
3c158f7f | 477 | struct nf_conn_help *help; |
9fb9cbb1 YK |
478 | struct nf_conntrack_tuple repl_tuple; |
479 | struct nf_conntrack_expect *exp; | |
480 | ||
605dcad6 | 481 | if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { |
0d53778e | 482 | pr_debug("Can't invert tuple.\n"); |
9fb9cbb1 YK |
483 | return NULL; |
484 | } | |
485 | ||
dacd2a1a | 486 | conntrack = nf_conntrack_alloc(tuple, &repl_tuple); |
9fb9cbb1 | 487 | if (conntrack == NULL || IS_ERR(conntrack)) { |
0d53778e | 488 | pr_debug("Can't allocate conntrack.\n"); |
9fb9cbb1 YK |
489 | return (struct nf_conntrack_tuple_hash *)conntrack; |
490 | } | |
491 | ||
605dcad6 | 492 | if (!l4proto->new(conntrack, skb, dataoff)) { |
9fb9cbb1 | 493 | nf_conntrack_free(conntrack); |
0d53778e | 494 | pr_debug("init conntrack: can't track with proto module\n"); |
9fb9cbb1 YK |
495 | return NULL; |
496 | } | |
497 | ||
498 | write_lock_bh(&nf_conntrack_lock); | |
6823645d | 499 | exp = nf_ct_find_expectation(tuple); |
9fb9cbb1 | 500 | if (exp) { |
0d53778e PM |
501 | pr_debug("conntrack: expectation arrives ct=%p exp=%p\n", |
502 | conntrack, exp); | |
9fb9cbb1 YK |
503 | /* Welcome, Mr. Bond. We've been expecting you... */ |
504 | __set_bit(IPS_EXPECTED_BIT, &conntrack->status); | |
505 | conntrack->master = exp->master; | |
ceceae1b | 506 | if (exp->helper) { |
b560580a | 507 | help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC); |
ceceae1b YK |
508 | if (help) |
509 | rcu_assign_pointer(help->helper, exp->helper); | |
ceceae1b YK |
510 | } |
511 | ||
9fb9cbb1 YK |
512 | #ifdef CONFIG_NF_CONNTRACK_MARK |
513 | conntrack->mark = exp->master->mark; | |
7c9728c3 JM |
514 | #endif |
515 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
516 | conntrack->secmark = exp->master->secmark; | |
9fb9cbb1 YK |
517 | #endif |
518 | nf_conntrack_get(&conntrack->master->ct_general); | |
519 | NF_CT_STAT_INC(expect_new); | |
22e7410b | 520 | } else { |
ceceae1b YK |
521 | struct nf_conntrack_helper *helper; |
522 | ||
523 | helper = __nf_ct_helper_find(&repl_tuple); | |
524 | if (helper) { | |
b560580a | 525 | help = nf_ct_helper_ext_add(conntrack, GFP_ATOMIC); |
ceceae1b | 526 | if (help) |
ceceae1b | 527 | rcu_assign_pointer(help->helper, helper); |
3c158f7f | 528 | } |
9fb9cbb1 | 529 | NF_CT_STAT_INC(new); |
22e7410b | 530 | } |
9fb9cbb1 YK |
531 | |
532 | /* Overload tuple linked list to put us in unconfirmed list. */ | |
f205c5e0 PM |
533 | hlist_add_head(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].hnode, |
534 | &unconfirmed); | |
9fb9cbb1 YK |
535 | |
536 | write_unlock_bh(&nf_conntrack_lock); | |
537 | ||
538 | if (exp) { | |
539 | if (exp->expectfn) | |
540 | exp->expectfn(conntrack, exp); | |
6823645d | 541 | nf_ct_expect_put(exp); |
9fb9cbb1 YK |
542 | } |
543 | ||
544 | return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL]; | |
545 | } | |
546 | ||
547 | /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ | |
548 | static inline struct nf_conn * | |
549 | resolve_normal_ct(struct sk_buff *skb, | |
550 | unsigned int dataoff, | |
551 | u_int16_t l3num, | |
552 | u_int8_t protonum, | |
553 | struct nf_conntrack_l3proto *l3proto, | |
605dcad6 | 554 | struct nf_conntrack_l4proto *l4proto, |
9fb9cbb1 YK |
555 | int *set_reply, |
556 | enum ip_conntrack_info *ctinfo) | |
557 | { | |
558 | struct nf_conntrack_tuple tuple; | |
559 | struct nf_conntrack_tuple_hash *h; | |
560 | struct nf_conn *ct; | |
561 | ||
bbe735e4 | 562 | if (!nf_ct_get_tuple(skb, skb_network_offset(skb), |
9fb9cbb1 | 563 | dataoff, l3num, protonum, &tuple, l3proto, |
605dcad6 | 564 | l4proto)) { |
0d53778e | 565 | pr_debug("resolve_normal_ct: Can't get tuple\n"); |
9fb9cbb1 YK |
566 | return NULL; |
567 | } | |
568 | ||
569 | /* look for tuple match */ | |
330f7db5 | 570 | h = nf_conntrack_find_get(&tuple); |
9fb9cbb1 | 571 | if (!h) { |
605dcad6 | 572 | h = init_conntrack(&tuple, l3proto, l4proto, skb, dataoff); |
9fb9cbb1 YK |
573 | if (!h) |
574 | return NULL; | |
575 | if (IS_ERR(h)) | |
576 | return (void *)h; | |
577 | } | |
578 | ct = nf_ct_tuplehash_to_ctrack(h); | |
579 | ||
580 | /* It exists; we have (non-exclusive) reference. */ | |
581 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { | |
582 | *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; | |
583 | /* Please set reply bit if this packet OK */ | |
584 | *set_reply = 1; | |
585 | } else { | |
586 | /* Once we've had two way comms, always ESTABLISHED. */ | |
587 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { | |
0d53778e | 588 | pr_debug("nf_conntrack_in: normal packet for %p\n", ct); |
9fb9cbb1 YK |
589 | *ctinfo = IP_CT_ESTABLISHED; |
590 | } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { | |
0d53778e PM |
591 | pr_debug("nf_conntrack_in: related packet for %p\n", |
592 | ct); | |
9fb9cbb1 YK |
593 | *ctinfo = IP_CT_RELATED; |
594 | } else { | |
0d53778e | 595 | pr_debug("nf_conntrack_in: new packet for %p\n", ct); |
9fb9cbb1 YK |
596 | *ctinfo = IP_CT_NEW; |
597 | } | |
598 | *set_reply = 0; | |
599 | } | |
600 | skb->nfct = &ct->ct_general; | |
601 | skb->nfctinfo = *ctinfo; | |
602 | return ct; | |
603 | } | |
604 | ||
605 | unsigned int | |
606 | nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) | |
607 | { | |
608 | struct nf_conn *ct; | |
609 | enum ip_conntrack_info ctinfo; | |
610 | struct nf_conntrack_l3proto *l3proto; | |
605dcad6 | 611 | struct nf_conntrack_l4proto *l4proto; |
9fb9cbb1 YK |
612 | unsigned int dataoff; |
613 | u_int8_t protonum; | |
614 | int set_reply = 0; | |
615 | int ret; | |
616 | ||
617 | /* Previously seen (loopback or untracked)? Ignore. */ | |
618 | if ((*pskb)->nfct) { | |
c0e912d7 | 619 | NF_CT_STAT_INC_ATOMIC(ignore); |
9fb9cbb1 YK |
620 | return NF_ACCEPT; |
621 | } | |
622 | ||
923f4902 | 623 | /* rcu_read_lock()ed by nf_hook_slow */ |
c1d10adb | 624 | l3proto = __nf_ct_l3proto_find((u_int16_t)pf); |
ffc30690 YK |
625 | ret = l3proto->get_l4proto(*pskb, skb_network_offset(*pskb), |
626 | &dataoff, &protonum); | |
627 | if (ret <= 0) { | |
0d53778e | 628 | pr_debug("not prepared to track yet or error occured\n"); |
d87d8469 YK |
629 | NF_CT_STAT_INC_ATOMIC(error); |
630 | NF_CT_STAT_INC_ATOMIC(invalid); | |
9fb9cbb1 YK |
631 | return -ret; |
632 | } | |
633 | ||
605dcad6 | 634 | l4proto = __nf_ct_l4proto_find((u_int16_t)pf, protonum); |
9fb9cbb1 YK |
635 | |
636 | /* It may be an special packet, error, unclean... | |
637 | * inverse of the return code tells to the netfilter | |
638 | * core what to do with the packet. */ | |
605dcad6 MJ |
639 | if (l4proto->error != NULL && |
640 | (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { | |
c0e912d7 PM |
641 | NF_CT_STAT_INC_ATOMIC(error); |
642 | NF_CT_STAT_INC_ATOMIC(invalid); | |
9fb9cbb1 YK |
643 | return -ret; |
644 | } | |
645 | ||
605dcad6 | 646 | ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto, |
9fb9cbb1 YK |
647 | &set_reply, &ctinfo); |
648 | if (!ct) { | |
649 | /* Not valid part of a connection */ | |
c0e912d7 | 650 | NF_CT_STAT_INC_ATOMIC(invalid); |
9fb9cbb1 YK |
651 | return NF_ACCEPT; |
652 | } | |
653 | ||
654 | if (IS_ERR(ct)) { | |
655 | /* Too stressed to deal. */ | |
c0e912d7 | 656 | NF_CT_STAT_INC_ATOMIC(drop); |
9fb9cbb1 YK |
657 | return NF_DROP; |
658 | } | |
659 | ||
660 | NF_CT_ASSERT((*pskb)->nfct); | |
661 | ||
605dcad6 | 662 | ret = l4proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum); |
9fb9cbb1 YK |
663 | if (ret < 0) { |
664 | /* Invalid: inverse of the return code tells | |
665 | * the netfilter core what to do */ | |
0d53778e | 666 | pr_debug("nf_conntrack_in: Can't track with proto module\n"); |
9fb9cbb1 YK |
667 | nf_conntrack_put((*pskb)->nfct); |
668 | (*pskb)->nfct = NULL; | |
c0e912d7 | 669 | NF_CT_STAT_INC_ATOMIC(invalid); |
9fb9cbb1 YK |
670 | return -ret; |
671 | } | |
672 | ||
673 | if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) | |
674 | nf_conntrack_event_cache(IPCT_STATUS, *pskb); | |
675 | ||
676 | return ret; | |
677 | } | |
13b18339 | 678 | EXPORT_SYMBOL_GPL(nf_conntrack_in); |
9fb9cbb1 YK |
679 | |
680 | int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, | |
681 | const struct nf_conntrack_tuple *orig) | |
682 | { | |
923f4902 PM |
683 | int ret; |
684 | ||
685 | rcu_read_lock(); | |
686 | ret = nf_ct_invert_tuple(inverse, orig, | |
687 | __nf_ct_l3proto_find(orig->src.l3num), | |
688 | __nf_ct_l4proto_find(orig->src.l3num, | |
689 | orig->dst.protonum)); | |
690 | rcu_read_unlock(); | |
691 | return ret; | |
9fb9cbb1 | 692 | } |
13b18339 | 693 | EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); |
9fb9cbb1 | 694 | |
5b1158e9 JK |
695 | /* Alter reply tuple (maybe alter helper). This is for NAT, and is |
696 | implicitly racy: see __nf_conntrack_confirm */ | |
697 | void nf_conntrack_alter_reply(struct nf_conn *ct, | |
698 | const struct nf_conntrack_tuple *newreply) | |
699 | { | |
700 | struct nf_conn_help *help = nfct_help(ct); | |
ceceae1b | 701 | struct nf_conntrack_helper *helper; |
5b1158e9 JK |
702 | |
703 | write_lock_bh(&nf_conntrack_lock); | |
704 | /* Should be unconfirmed, so not in hash table yet */ | |
705 | NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); | |
706 | ||
0d53778e | 707 | pr_debug("Altering reply tuple of %p to ", ct); |
5b1158e9 JK |
708 | NF_CT_DUMP_TUPLE(newreply); |
709 | ||
710 | ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; | |
ceceae1b YK |
711 | if (ct->master || (help && help->expecting != 0)) |
712 | goto out; | |
713 | ||
714 | helper = __nf_ct_helper_find(newreply); | |
715 | if (helper == NULL) { | |
716 | if (help) | |
717 | rcu_assign_pointer(help->helper, NULL); | |
718 | goto out; | |
5d78a849 | 719 | } |
ceceae1b YK |
720 | |
721 | if (help == NULL) { | |
b560580a PM |
722 | help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); |
723 | if (help == NULL) | |
ceceae1b | 724 | goto out; |
ceceae1b YK |
725 | } else { |
726 | memset(&help->help, 0, sizeof(help->help)); | |
727 | } | |
728 | ||
729 | rcu_assign_pointer(help->helper, helper); | |
730 | out: | |
5b1158e9 JK |
731 | write_unlock_bh(&nf_conntrack_lock); |
732 | } | |
13b18339 | 733 | EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); |
5b1158e9 | 734 | |
9fb9cbb1 YK |
735 | /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ |
736 | void __nf_ct_refresh_acct(struct nf_conn *ct, | |
737 | enum ip_conntrack_info ctinfo, | |
738 | const struct sk_buff *skb, | |
739 | unsigned long extra_jiffies, | |
740 | int do_acct) | |
741 | { | |
742 | int event = 0; | |
743 | ||
744 | NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); | |
745 | NF_CT_ASSERT(skb); | |
746 | ||
747 | write_lock_bh(&nf_conntrack_lock); | |
748 | ||
997ae831 EL |
749 | /* Only update if this is not a fixed timeout */ |
750 | if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) { | |
751 | write_unlock_bh(&nf_conntrack_lock); | |
752 | return; | |
753 | } | |
754 | ||
9fb9cbb1 YK |
755 | /* If not in hash table, timer will not be active yet */ |
756 | if (!nf_ct_is_confirmed(ct)) { | |
757 | ct->timeout.expires = extra_jiffies; | |
758 | event = IPCT_REFRESH; | |
759 | } else { | |
be00c8e4 MJ |
760 | unsigned long newtime = jiffies + extra_jiffies; |
761 | ||
762 | /* Only update the timeout if the new timeout is at least | |
763 | HZ jiffies from the old timeout. Need del_timer for race | |
764 | avoidance (may already be dying). */ | |
765 | if (newtime - ct->timeout.expires >= HZ | |
766 | && del_timer(&ct->timeout)) { | |
767 | ct->timeout.expires = newtime; | |
9fb9cbb1 YK |
768 | add_timer(&ct->timeout); |
769 | event = IPCT_REFRESH; | |
770 | } | |
771 | } | |
772 | ||
773 | #ifdef CONFIG_NF_CT_ACCT | |
774 | if (do_acct) { | |
775 | ct->counters[CTINFO2DIR(ctinfo)].packets++; | |
776 | ct->counters[CTINFO2DIR(ctinfo)].bytes += | |
bbe735e4 | 777 | skb->len - skb_network_offset(skb); |
3ffd5eeb MJ |
778 | |
779 | if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000) | |
780 | || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000)) | |
781 | event |= IPCT_COUNTER_FILLING; | |
9fb9cbb1 YK |
782 | } |
783 | #endif | |
784 | ||
785 | write_unlock_bh(&nf_conntrack_lock); | |
786 | ||
787 | /* must be unlocked when calling event cache */ | |
788 | if (event) | |
789 | nf_conntrack_event_cache(event, skb); | |
790 | } | |
13b18339 | 791 | EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); |
9fb9cbb1 | 792 | |
e281db5c | 793 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
794 | |
795 | #include <linux/netfilter/nfnetlink.h> | |
796 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
57b47a53 IM |
797 | #include <linux/mutex.h> |
798 | ||
c1d10adb PNA |
799 | |
800 | /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be | |
801 | * in ip_conntrack_core, since we don't want the protocols to autoload | |
802 | * or depend on ctnetlink */ | |
803 | int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb, | |
804 | const struct nf_conntrack_tuple *tuple) | |
805 | { | |
806 | NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t), | |
807 | &tuple->src.u.tcp.port); | |
808 | NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t), | |
809 | &tuple->dst.u.tcp.port); | |
810 | return 0; | |
811 | ||
812 | nfattr_failure: | |
813 | return -1; | |
814 | } | |
13b18339 | 815 | EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr); |
c1d10adb PNA |
816 | |
817 | static const size_t cta_min_proto[CTA_PROTO_MAX] = { | |
818 | [CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t), | |
819 | [CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t) | |
820 | }; | |
821 | ||
822 | int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[], | |
823 | struct nf_conntrack_tuple *t) | |
824 | { | |
825 | if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1]) | |
826 | return -EINVAL; | |
827 | ||
828 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
829 | return -EINVAL; | |
830 | ||
bff9a89b PM |
831 | t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]); |
832 | t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]); | |
c1d10adb PNA |
833 | |
834 | return 0; | |
835 | } | |
13b18339 | 836 | EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple); |
c1d10adb PNA |
837 | #endif |
838 | ||
9fb9cbb1 YK |
839 | /* Used by ipt_REJECT and ip6t_REJECT. */ |
840 | void __nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) | |
841 | { | |
842 | struct nf_conn *ct; | |
843 | enum ip_conntrack_info ctinfo; | |
844 | ||
845 | /* This ICMP is in reverse direction to the packet which caused it */ | |
846 | ct = nf_ct_get(skb, &ctinfo); | |
847 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) | |
848 | ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; | |
849 | else | |
850 | ctinfo = IP_CT_RELATED; | |
851 | ||
852 | /* Attach to new skbuff, and increment count */ | |
853 | nskb->nfct = &ct->ct_general; | |
854 | nskb->nfctinfo = ctinfo; | |
855 | nf_conntrack_get(nskb->nfct); | |
856 | } | |
13b18339 | 857 | EXPORT_SYMBOL_GPL(__nf_conntrack_attach); |
9fb9cbb1 YK |
858 | |
859 | static inline int | |
860 | do_iter(const struct nf_conntrack_tuple_hash *i, | |
861 | int (*iter)(struct nf_conn *i, void *data), | |
862 | void *data) | |
863 | { | |
864 | return iter(nf_ct_tuplehash_to_ctrack(i), data); | |
865 | } | |
866 | ||
867 | /* Bring out ya dead! */ | |
df0933dc | 868 | static struct nf_conn * |
9fb9cbb1 YK |
869 | get_next_corpse(int (*iter)(struct nf_conn *i, void *data), |
870 | void *data, unsigned int *bucket) | |
871 | { | |
df0933dc PM |
872 | struct nf_conntrack_tuple_hash *h; |
873 | struct nf_conn *ct; | |
f205c5e0 | 874 | struct hlist_node *n; |
9fb9cbb1 YK |
875 | |
876 | write_lock_bh(&nf_conntrack_lock); | |
877 | for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { | |
f205c5e0 | 878 | hlist_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnode) { |
df0933dc PM |
879 | ct = nf_ct_tuplehash_to_ctrack(h); |
880 | if (iter(ct, data)) | |
881 | goto found; | |
882 | } | |
601e68e1 | 883 | } |
f205c5e0 | 884 | hlist_for_each_entry(h, n, &unconfirmed, hnode) { |
df0933dc PM |
885 | ct = nf_ct_tuplehash_to_ctrack(h); |
886 | if (iter(ct, data)) | |
ec68e97d | 887 | set_bit(IPS_DYING_BIT, &ct->status); |
df0933dc | 888 | } |
c073e3fa | 889 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc PM |
890 | return NULL; |
891 | found: | |
c073e3fa | 892 | atomic_inc(&ct->ct_general.use); |
9fb9cbb1 | 893 | write_unlock_bh(&nf_conntrack_lock); |
df0933dc | 894 | return ct; |
9fb9cbb1 YK |
895 | } |
896 | ||
897 | void | |
898 | nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data) | |
899 | { | |
df0933dc | 900 | struct nf_conn *ct; |
9fb9cbb1 YK |
901 | unsigned int bucket = 0; |
902 | ||
df0933dc | 903 | while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) { |
9fb9cbb1 YK |
904 | /* Time to push up daises... */ |
905 | if (del_timer(&ct->timeout)) | |
906 | death_by_timeout((unsigned long)ct); | |
907 | /* ... else the timer will get him soon. */ | |
908 | ||
909 | nf_ct_put(ct); | |
910 | } | |
911 | } | |
13b18339 | 912 | EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); |
9fb9cbb1 YK |
913 | |
914 | static int kill_all(struct nf_conn *i, void *data) | |
915 | { | |
916 | return 1; | |
917 | } | |
918 | ||
ac565e5f | 919 | void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, int size) |
9fb9cbb1 YK |
920 | { |
921 | if (vmalloced) | |
922 | vfree(hash); | |
923 | else | |
601e68e1 | 924 | free_pages((unsigned long)hash, |
f205c5e0 | 925 | get_order(sizeof(struct hlist_head) * size)); |
9fb9cbb1 | 926 | } |
ac565e5f | 927 | EXPORT_SYMBOL_GPL(nf_ct_free_hashtable); |
9fb9cbb1 | 928 | |
272491ef | 929 | void nf_conntrack_flush(void) |
c1d10adb PNA |
930 | { |
931 | nf_ct_iterate_cleanup(kill_all, NULL); | |
932 | } | |
13b18339 | 933 | EXPORT_SYMBOL_GPL(nf_conntrack_flush); |
c1d10adb | 934 | |
9fb9cbb1 YK |
935 | /* Mishearing the voices in his head, our hero wonders how he's |
936 | supposed to kill the mall. */ | |
937 | void nf_conntrack_cleanup(void) | |
938 | { | |
c3a47ab3 | 939 | rcu_assign_pointer(ip_ct_attach, NULL); |
7d3cdc6b | 940 | |
9fb9cbb1 YK |
941 | /* This makes sure all current packets have passed through |
942 | netfilter framework. Roll on, two-stage module | |
943 | delete... */ | |
944 | synchronize_net(); | |
945 | ||
946 | nf_ct_event_cache_flush(); | |
947 | i_see_dead_people: | |
c1d10adb | 948 | nf_conntrack_flush(); |
9fb9cbb1 YK |
949 | if (atomic_read(&nf_conntrack_count) != 0) { |
950 | schedule(); | |
951 | goto i_see_dead_people; | |
952 | } | |
6636568c PM |
953 | /* wait until all references to nf_conntrack_untracked are dropped */ |
954 | while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1) | |
955 | schedule(); | |
9fb9cbb1 | 956 | |
de6e05c4 YK |
957 | rcu_assign_pointer(nf_ct_destroy, NULL); |
958 | ||
dacd2a1a | 959 | kmem_cache_destroy(nf_conntrack_cachep); |
ac565e5f PM |
960 | nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc, |
961 | nf_conntrack_htable_size); | |
5a6f294e | 962 | |
ac5357eb | 963 | nf_conntrack_proto_fini(); |
ceceae1b | 964 | nf_conntrack_helper_fini(); |
e9c1b084 | 965 | nf_conntrack_expect_fini(); |
9fb9cbb1 YK |
966 | } |
967 | ||
ac565e5f | 968 | struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced) |
9fb9cbb1 | 969 | { |
f205c5e0 | 970 | struct hlist_head *hash; |
8e5105a0 | 971 | unsigned int size, i; |
9fb9cbb1 | 972 | |
601e68e1 | 973 | *vmalloced = 0; |
8e5105a0 | 974 | |
f205c5e0 | 975 | size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head)); |
601e68e1 | 976 | hash = (void*)__get_free_pages(GFP_KERNEL, |
f205c5e0 | 977 | get_order(sizeof(struct hlist_head) |
9fb9cbb1 | 978 | * size)); |
601e68e1 | 979 | if (!hash) { |
9fb9cbb1 YK |
980 | *vmalloced = 1; |
981 | printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); | |
f205c5e0 | 982 | hash = vmalloc(sizeof(struct hlist_head) * size); |
9fb9cbb1 YK |
983 | } |
984 | ||
985 | if (hash) | |
601e68e1 | 986 | for (i = 0; i < size; i++) |
f205c5e0 | 987 | INIT_HLIST_HEAD(&hash[i]); |
9fb9cbb1 YK |
988 | |
989 | return hash; | |
990 | } | |
ac565e5f | 991 | EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable); |
9fb9cbb1 YK |
992 | |
993 | int set_hashsize(const char *val, struct kernel_param *kp) | |
994 | { | |
995 | int i, bucket, hashsize, vmalloced; | |
996 | int old_vmalloced, old_size; | |
997 | int rnd; | |
f205c5e0 | 998 | struct hlist_head *hash, *old_hash; |
9fb9cbb1 YK |
999 | struct nf_conntrack_tuple_hash *h; |
1000 | ||
1001 | /* On boot, we can set this without any fancy locking. */ | |
1002 | if (!nf_conntrack_htable_size) | |
1003 | return param_set_uint(val, kp); | |
1004 | ||
1005 | hashsize = simple_strtol(val, NULL, 0); | |
1006 | if (!hashsize) | |
1007 | return -EINVAL; | |
1008 | ||
ac565e5f | 1009 | hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced); |
9fb9cbb1 YK |
1010 | if (!hash) |
1011 | return -ENOMEM; | |
1012 | ||
1013 | /* We have to rehahs for the new table anyway, so we also can | |
1014 | * use a newrandom seed */ | |
1015 | get_random_bytes(&rnd, 4); | |
1016 | ||
1017 | write_lock_bh(&nf_conntrack_lock); | |
1018 | for (i = 0; i < nf_conntrack_htable_size; i++) { | |
f205c5e0 PM |
1019 | while (!hlist_empty(&nf_conntrack_hash[i])) { |
1020 | h = hlist_entry(nf_conntrack_hash[i].first, | |
1021 | struct nf_conntrack_tuple_hash, hnode); | |
1022 | hlist_del(&h->hnode); | |
9fb9cbb1 | 1023 | bucket = __hash_conntrack(&h->tuple, hashsize, rnd); |
f205c5e0 | 1024 | hlist_add_head(&h->hnode, &hash[bucket]); |
9fb9cbb1 YK |
1025 | } |
1026 | } | |
1027 | old_size = nf_conntrack_htable_size; | |
1028 | old_vmalloced = nf_conntrack_vmalloc; | |
1029 | old_hash = nf_conntrack_hash; | |
1030 | ||
1031 | nf_conntrack_htable_size = hashsize; | |
1032 | nf_conntrack_vmalloc = vmalloced; | |
1033 | nf_conntrack_hash = hash; | |
1034 | nf_conntrack_hash_rnd = rnd; | |
1035 | write_unlock_bh(&nf_conntrack_lock); | |
1036 | ||
ac565e5f | 1037 | nf_ct_free_hashtable(old_hash, old_vmalloced, old_size); |
9fb9cbb1 YK |
1038 | return 0; |
1039 | } | |
1040 | ||
1041 | module_param_call(hashsize, set_hashsize, param_get_uint, | |
1042 | &nf_conntrack_htable_size, 0600); | |
1043 | ||
1044 | int __init nf_conntrack_init(void) | |
1045 | { | |
f205c5e0 | 1046 | int max_factor = 8; |
9fb9cbb1 YK |
1047 | int ret; |
1048 | ||
1049 | /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB | |
f205c5e0 | 1050 | * machine has 512 buckets. >= 1GB machines have 16384 buckets. */ |
9fb9cbb1 YK |
1051 | if (!nf_conntrack_htable_size) { |
1052 | nf_conntrack_htable_size | |
1053 | = (((num_physpages << PAGE_SHIFT) / 16384) | |
f205c5e0 | 1054 | / sizeof(struct hlist_head)); |
9fb9cbb1 | 1055 | if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE)) |
f205c5e0 PM |
1056 | nf_conntrack_htable_size = 16384; |
1057 | if (nf_conntrack_htable_size < 32) | |
1058 | nf_conntrack_htable_size = 32; | |
1059 | ||
1060 | /* Use a max. factor of four by default to get the same max as | |
1061 | * with the old struct list_heads. When a table size is given | |
1062 | * we use the old value of 8 to avoid reducing the max. | |
1063 | * entries. */ | |
1064 | max_factor = 4; | |
9fb9cbb1 | 1065 | } |
ac565e5f PM |
1066 | nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, |
1067 | &nf_conntrack_vmalloc); | |
9fb9cbb1 YK |
1068 | if (!nf_conntrack_hash) { |
1069 | printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); | |
1070 | goto err_out; | |
1071 | } | |
1072 | ||
f205c5e0 | 1073 | nf_conntrack_max = max_factor * nf_conntrack_htable_size; |
8e5105a0 PM |
1074 | |
1075 | printk("nf_conntrack version %s (%u buckets, %d max)\n", | |
1076 | NF_CONNTRACK_VERSION, nf_conntrack_htable_size, | |
1077 | nf_conntrack_max); | |
1078 | ||
dacd2a1a YK |
1079 | nf_conntrack_cachep = kmem_cache_create("nf_conntrack", |
1080 | sizeof(struct nf_conn), | |
1081 | 0, 0, NULL, NULL); | |
1082 | if (!nf_conntrack_cachep) { | |
9fb9cbb1 YK |
1083 | printk(KERN_ERR "Unable to create nf_conn slab cache\n"); |
1084 | goto err_free_hash; | |
1085 | } | |
1086 | ||
e9c1b084 PM |
1087 | ret = nf_conntrack_proto_init(); |
1088 | if (ret < 0) | |
9fb9cbb1 | 1089 | goto err_free_conntrack_slab; |
9fb9cbb1 | 1090 | |
e9c1b084 | 1091 | ret = nf_conntrack_expect_init(); |
933a41e7 | 1092 | if (ret < 0) |
e9c1b084 | 1093 | goto out_fini_proto; |
933a41e7 | 1094 | |
ceceae1b YK |
1095 | ret = nf_conntrack_helper_init(); |
1096 | if (ret < 0) | |
e9c1b084 | 1097 | goto out_fini_expect; |
ceceae1b | 1098 | |
7d3cdc6b | 1099 | /* For use by REJECT target */ |
c3a47ab3 | 1100 | rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach); |
de6e05c4 | 1101 | rcu_assign_pointer(nf_ct_destroy, destroy_conntrack); |
7d3cdc6b | 1102 | |
9fb9cbb1 YK |
1103 | /* Set up fake conntrack: |
1104 | - to never be deleted, not in any hashes */ | |
1105 | atomic_set(&nf_conntrack_untracked.ct_general.use, 1); | |
1106 | /* - and look it like as a confirmed connection */ | |
1107 | set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status); | |
1108 | ||
1109 | return ret; | |
1110 | ||
e9c1b084 PM |
1111 | out_fini_expect: |
1112 | nf_conntrack_expect_fini(); | |
ceceae1b YK |
1113 | out_fini_proto: |
1114 | nf_conntrack_proto_fini(); | |
9fb9cbb1 | 1115 | err_free_conntrack_slab: |
dacd2a1a | 1116 | kmem_cache_destroy(nf_conntrack_cachep); |
9fb9cbb1 | 1117 | err_free_hash: |
ac565e5f PM |
1118 | nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc, |
1119 | nf_conntrack_htable_size); | |
9fb9cbb1 YK |
1120 | err_out: |
1121 | return -ENOMEM; | |
1122 | } |