Commit | Line | Data |
---|---|---|
7e5d03bb MJ |
1 | /* Helper handling for netfilter. */ |
2 | ||
3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> | |
5 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> | |
f229f6ce | 6 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
7e5d03bb MJ |
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 | ||
13 | #include <linux/types.h> | |
14 | #include <linux/netfilter.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/stddef.h> | |
7e5d03bb MJ |
19 | #include <linux/random.h> |
20 | #include <linux/err.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/netdevice.h> | |
2ba4cc31 | 23 | #include <linux/rculist.h> |
efb9a8c2 | 24 | #include <linux/rtnetlink.h> |
7e5d03bb | 25 | |
7e5d03bb | 26 | #include <net/netfilter/nf_conntrack.h> |
605dcad6 | 27 | #include <net/netfilter/nf_conntrack_l4proto.h> |
7e5d03bb MJ |
28 | #include <net/netfilter/nf_conntrack_helper.h> |
29 | #include <net/netfilter/nf_conntrack_core.h> | |
ceceae1b | 30 | #include <net/netfilter/nf_conntrack_extend.h> |
b20ab9cc | 31 | #include <net/netfilter/nf_log.h> |
7e5d03bb | 32 | |
58a3c9bb | 33 | static DEFINE_MUTEX(nf_ct_helper_mutex); |
12f7a505 PNA |
34 | struct hlist_head *nf_ct_helper_hash __read_mostly; |
35 | EXPORT_SYMBOL_GPL(nf_ct_helper_hash); | |
36 | unsigned int nf_ct_helper_hsize __read_mostly; | |
37 | EXPORT_SYMBOL_GPL(nf_ct_helper_hsize); | |
b8a7fe6c | 38 | static unsigned int nf_ct_helper_count __read_mostly; |
b8a7fe6c | 39 | |
3bb398d9 | 40 | static bool nf_ct_auto_assign_helper __read_mostly = false; |
a9006892 EL |
41 | module_param_named(nf_conntrack_helper, nf_ct_auto_assign_helper, bool, 0644); |
42 | MODULE_PARM_DESC(nf_conntrack_helper, | |
3bb398d9 | 43 | "Enable automatic conntrack helper assignment (default 0)"); |
a9006892 | 44 | |
08010a21 FL |
45 | static DEFINE_MUTEX(nf_ct_nat_helpers_mutex); |
46 | static struct list_head nf_ct_nat_helpers __read_mostly; | |
47 | ||
b8a7fe6c PM |
48 | /* Stupid hash, but collision free for the default registrations of the |
49 | * helpers currently in the kernel. */ | |
50 | static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) | |
51 | { | |
52 | return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^ | |
a34c4589 | 53 | (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize; |
b8a7fe6c | 54 | } |
7e5d03bb | 55 | |
226c0c0e | 56 | static struct nf_conntrack_helper * |
7e5d03bb MJ |
57 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
58 | { | |
b8a7fe6c | 59 | struct nf_conntrack_helper *helper; |
d4156e8c | 60 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
b8a7fe6c | 61 | unsigned int h; |
7e5d03bb | 62 | |
b8a7fe6c PM |
63 | if (!nf_ct_helper_count) |
64 | return NULL; | |
65 | ||
66 | h = helper_hash(tuple); | |
b67bfe0d | 67 | hlist_for_each_entry_rcu(helper, &nf_ct_helper_hash[h], hnode) { |
b8a7fe6c PM |
68 | if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask)) |
69 | return helper; | |
7e5d03bb MJ |
70 | } |
71 | return NULL; | |
72 | } | |
7e5d03bb MJ |
73 | |
74 | struct nf_conntrack_helper * | |
794e6871 | 75 | __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum) |
7e5d03bb MJ |
76 | { |
77 | struct nf_conntrack_helper *h; | |
b8a7fe6c | 78 | unsigned int i; |
7e5d03bb | 79 | |
b8a7fe6c | 80 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
b67bfe0d | 81 | hlist_for_each_entry_rcu(h, &nf_ct_helper_hash[i], hnode) { |
6114cc51 FW |
82 | if (strcmp(h->name, name)) |
83 | continue; | |
84 | ||
85 | if (h->tuple.src.l3num != NFPROTO_UNSPEC && | |
86 | h->tuple.src.l3num != l3num) | |
87 | continue; | |
88 | ||
89 | if (h->tuple.dst.protonum == protonum) | |
b8a7fe6c PM |
90 | return h; |
91 | } | |
7e5d03bb | 92 | } |
7e5d03bb MJ |
93 | return NULL; |
94 | } | |
794e6871 | 95 | EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find); |
7e5d03bb | 96 | |
84f3bb9a PM |
97 | struct nf_conntrack_helper * |
98 | nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum) | |
99 | { | |
100 | struct nf_conntrack_helper *h; | |
101 | ||
8b5995d0 GF |
102 | rcu_read_lock(); |
103 | ||
84f3bb9a PM |
104 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
105 | #ifdef CONFIG_MODULES | |
106 | if (h == NULL) { | |
8b5995d0 GF |
107 | rcu_read_unlock(); |
108 | if (request_module("nfct-helper-%s", name) == 0) { | |
109 | rcu_read_lock(); | |
84f3bb9a | 110 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
8b5995d0 GF |
111 | } else { |
112 | return h; | |
113 | } | |
84f3bb9a PM |
114 | } |
115 | #endif | |
116 | if (h != NULL && !try_module_get(h->me)) | |
117 | h = NULL; | |
9338d7b4 LZ |
118 | if (h != NULL && !refcount_inc_not_zero(&h->refcnt)) { |
119 | module_put(h->me); | |
120 | h = NULL; | |
121 | } | |
84f3bb9a | 122 | |
8b5995d0 GF |
123 | rcu_read_unlock(); |
124 | ||
84f3bb9a PM |
125 | return h; |
126 | } | |
127 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get); | |
128 | ||
d91fc59c LZ |
129 | void nf_conntrack_helper_put(struct nf_conntrack_helper *helper) |
130 | { | |
9338d7b4 | 131 | refcount_dec(&helper->refcnt); |
d91fc59c LZ |
132 | module_put(helper->me); |
133 | } | |
134 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_put); | |
135 | ||
08010a21 FL |
136 | static struct nf_conntrack_nat_helper * |
137 | nf_conntrack_nat_helper_find(const char *mod_name) | |
138 | { | |
139 | struct nf_conntrack_nat_helper *cur; | |
140 | bool found = false; | |
141 | ||
142 | list_for_each_entry_rcu(cur, &nf_ct_nat_helpers, list) { | |
143 | if (!strcmp(cur->mod_name, mod_name)) { | |
144 | found = true; | |
145 | break; | |
146 | } | |
147 | } | |
148 | return found ? cur : NULL; | |
149 | } | |
150 | ||
151 | int | |
152 | nf_nat_helper_try_module_get(const char *name, u16 l3num, u8 protonum) | |
153 | { | |
154 | struct nf_conntrack_helper *h; | |
155 | struct nf_conntrack_nat_helper *nat; | |
156 | char mod_name[NF_CT_HELPER_NAME_LEN]; | |
157 | int ret = 0; | |
158 | ||
159 | rcu_read_lock(); | |
160 | h = __nf_conntrack_helper_find(name, l3num, protonum); | |
161 | if (!h) { | |
162 | rcu_read_unlock(); | |
163 | return -ENOENT; | |
164 | } | |
165 | ||
166 | nat = nf_conntrack_nat_helper_find(h->nat_mod_name); | |
167 | if (!nat) { | |
168 | snprintf(mod_name, sizeof(mod_name), "%s", h->nat_mod_name); | |
169 | rcu_read_unlock(); | |
170 | request_module(mod_name); | |
171 | ||
172 | rcu_read_lock(); | |
173 | nat = nf_conntrack_nat_helper_find(mod_name); | |
174 | if (!nat) { | |
175 | rcu_read_unlock(); | |
176 | return -ENOENT; | |
177 | } | |
178 | } | |
179 | ||
180 | if (!try_module_get(nat->module)) | |
181 | ret = -ENOENT; | |
182 | ||
183 | rcu_read_unlock(); | |
184 | return ret; | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(nf_nat_helper_try_module_get); | |
187 | ||
188 | void nf_nat_helper_put(struct nf_conntrack_helper *helper) | |
189 | { | |
190 | struct nf_conntrack_nat_helper *nat; | |
191 | ||
192 | nat = nf_conntrack_nat_helper_find(helper->nat_mod_name); | |
193 | if (WARN_ON_ONCE(!nat)) | |
194 | return; | |
195 | ||
196 | module_put(nat->module); | |
197 | } | |
198 | EXPORT_SYMBOL_GPL(nf_nat_helper_put); | |
199 | ||
1afc5679 | 200 | struct nf_conn_help * |
440534d3 | 201 | nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp) |
b560580a PM |
202 | { |
203 | struct nf_conn_help *help; | |
204 | ||
9f0f3ebe | 205 | help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp); |
b560580a PM |
206 | if (help) |
207 | INIT_HLIST_HEAD(&help->expectations); | |
208 | else | |
209 | pr_debug("failed to add helper extension area"); | |
210 | return help; | |
211 | } | |
212 | EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add); | |
213 | ||
dfe75ff8 JK |
214 | static struct nf_conntrack_helper * |
215 | nf_ct_lookup_helper(struct nf_conn *ct, struct net *net) | |
216 | { | |
217 | if (!net->ct.sysctl_auto_assign_helper) { | |
218 | if (net->ct.auto_assign_helper_warned) | |
219 | return NULL; | |
220 | if (!__nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple)) | |
221 | return NULL; | |
222 | pr_info("nf_conntrack: default automatic helper assignment " | |
223 | "has been turned off for security reasons and CT-based " | |
224 | " firewall rule not found. Use the iptables CT target " | |
225 | "to attach helpers instead.\n"); | |
226 | net->ct.auto_assign_helper_warned = 1; | |
227 | return NULL; | |
228 | } | |
229 | ||
230 | return __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
231 | } | |
232 | ||
233 | ||
b2a15a60 PM |
234 | int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, |
235 | gfp_t flags) | |
226c0c0e | 236 | { |
b2a15a60 PM |
237 | struct nf_conntrack_helper *helper = NULL; |
238 | struct nf_conn_help *help; | |
a9006892 | 239 | struct net *net = nf_ct_net(ct); |
226c0c0e | 240 | |
6714cf54 PNA |
241 | /* We already got a helper explicitly attached. The function |
242 | * nf_conntrack_alter_reply - in case NAT is in use - asks for looking | |
243 | * the helper up again. Since now the user is in full control of | |
244 | * making consistent helper configurations, skip this automatic | |
245 | * re-lookup, otherwise we'll lose the helper. | |
246 | */ | |
247 | if (test_bit(IPS_HELPER_BIT, &ct->status)) | |
248 | return 0; | |
249 | ||
b2a15a60 PM |
250 | if (tmpl != NULL) { |
251 | help = nfct_help(tmpl); | |
6714cf54 | 252 | if (help != NULL) { |
b2a15a60 | 253 | helper = help->helper; |
6714cf54 PNA |
254 | set_bit(IPS_HELPER_BIT, &ct->status); |
255 | } | |
b2a15a60 PM |
256 | } |
257 | ||
258 | help = nfct_help(ct); | |
a9006892 | 259 | |
226c0c0e | 260 | if (helper == NULL) { |
dfe75ff8 JK |
261 | helper = nf_ct_lookup_helper(ct, net); |
262 | if (helper == NULL) { | |
263 | if (help) | |
264 | RCU_INIT_POINTER(help->helper, NULL); | |
265 | return 0; | |
266 | } | |
226c0c0e PNA |
267 | } |
268 | ||
269 | if (help == NULL) { | |
440534d3 | 270 | help = nf_ct_helper_ext_add(ct, flags); |
cf71c03e PN |
271 | if (help == NULL) |
272 | return -ENOMEM; | |
226c0c0e | 273 | } else { |
32f53760 PNA |
274 | /* We only allow helper re-assignment of the same sort since |
275 | * we cannot reallocate the helper extension area. | |
276 | */ | |
6e2f0aa8 FW |
277 | struct nf_conntrack_helper *tmp = rcu_dereference(help->helper); |
278 | ||
279 | if (tmp && tmp->help != helper->help) { | |
32f53760 | 280 | RCU_INIT_POINTER(help->helper, NULL); |
cf71c03e | 281 | return 0; |
32f53760 | 282 | } |
226c0c0e PNA |
283 | } |
284 | ||
cf778b00 | 285 | rcu_assign_pointer(help->helper, helper); |
cf71c03e PN |
286 | |
287 | return 0; | |
226c0c0e PNA |
288 | } |
289 | EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper); | |
290 | ||
01cfa0a4 | 291 | /* appropriate ct lock protecting must be taken by caller */ |
ff1acc49 | 292 | static int unhelp(struct nf_conn *ct, void *me) |
7e5d03bb | 293 | { |
7e5d03bb MJ |
294 | struct nf_conn_help *help = nfct_help(ct); |
295 | ||
ca7433df | 296 | if (help && rcu_dereference_raw(help->helper) == me) { |
7e5d03bb | 297 | nf_conntrack_event(IPCT_HELPER, ct); |
a9b3cd7f | 298 | RCU_INIT_POINTER(help->helper, NULL); |
7e5d03bb | 299 | } |
ff1acc49 LZ |
300 | |
301 | /* We are not intended to delete this conntrack. */ | |
7e5d03bb MJ |
302 | return 0; |
303 | } | |
304 | ||
9858a3ae PNA |
305 | void nf_ct_helper_destroy(struct nf_conn *ct) |
306 | { | |
307 | struct nf_conn_help *help = nfct_help(ct); | |
308 | struct nf_conntrack_helper *helper; | |
309 | ||
310 | if (help) { | |
311 | rcu_read_lock(); | |
312 | helper = rcu_dereference(help->helper); | |
313 | if (helper && helper->destroy) | |
314 | helper->destroy(ct); | |
315 | rcu_read_unlock(); | |
316 | } | |
317 | } | |
318 | ||
544d5c7d PNA |
319 | static LIST_HEAD(nf_ct_helper_expectfn_list); |
320 | ||
321 | void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n) | |
322 | { | |
ca7433df | 323 | spin_lock_bh(&nf_conntrack_expect_lock); |
544d5c7d | 324 | list_add_rcu(&n->head, &nf_ct_helper_expectfn_list); |
ca7433df | 325 | spin_unlock_bh(&nf_conntrack_expect_lock); |
544d5c7d PNA |
326 | } |
327 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_register); | |
328 | ||
329 | void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n) | |
330 | { | |
ca7433df | 331 | spin_lock_bh(&nf_conntrack_expect_lock); |
544d5c7d | 332 | list_del_rcu(&n->head); |
ca7433df | 333 | spin_unlock_bh(&nf_conntrack_expect_lock); |
544d5c7d PNA |
334 | } |
335 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister); | |
336 | ||
8b5995d0 | 337 | /* Caller should hold the rcu lock */ |
544d5c7d PNA |
338 | struct nf_ct_helper_expectfn * |
339 | nf_ct_helper_expectfn_find_by_name(const char *name) | |
340 | { | |
341 | struct nf_ct_helper_expectfn *cur; | |
342 | bool found = false; | |
343 | ||
544d5c7d PNA |
344 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
345 | if (!strcmp(cur->name, name)) { | |
346 | found = true; | |
347 | break; | |
348 | } | |
349 | } | |
544d5c7d PNA |
350 | return found ? cur : NULL; |
351 | } | |
352 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name); | |
353 | ||
8b5995d0 | 354 | /* Caller should hold the rcu lock */ |
544d5c7d PNA |
355 | struct nf_ct_helper_expectfn * |
356 | nf_ct_helper_expectfn_find_by_symbol(const void *symbol) | |
357 | { | |
358 | struct nf_ct_helper_expectfn *cur; | |
359 | bool found = false; | |
360 | ||
544d5c7d PNA |
361 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
362 | if (cur->expectfn == symbol) { | |
363 | found = true; | |
364 | break; | |
365 | } | |
366 | } | |
544d5c7d PNA |
367 | return found ? cur : NULL; |
368 | } | |
369 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol); | |
370 | ||
b20ab9cc PNA |
371 | __printf(3, 4) |
372 | void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, | |
373 | const char *fmt, ...) | |
374 | { | |
375 | const struct nf_conn_help *help; | |
376 | const struct nf_conntrack_helper *helper; | |
f9caed59 JP |
377 | struct va_format vaf; |
378 | va_list args; | |
379 | ||
380 | va_start(args, fmt); | |
381 | ||
382 | vaf.fmt = fmt; | |
383 | vaf.va = &args; | |
b20ab9cc PNA |
384 | |
385 | /* Called from the helper function, this call never fails */ | |
386 | help = nfct_help(ct); | |
387 | ||
e2361cb9 | 388 | /* rcu_read_lock()ed by nf_hook_thresh */ |
b20ab9cc PNA |
389 | helper = rcu_dereference(help->helper); |
390 | ||
30e0c6a6 | 391 | nf_log_packet(nf_ct_net(ct), nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, |
f9caed59 JP |
392 | "nf_ct_%s: dropping packet: %pV ", helper->name, &vaf); |
393 | ||
394 | va_end(args); | |
b20ab9cc PNA |
395 | } |
396 | EXPORT_SYMBOL_GPL(nf_ct_helper_log); | |
397 | ||
7e5d03bb MJ |
398 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
399 | { | |
893e093c | 400 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
b8a7fe6c | 401 | unsigned int h = helper_hash(&me->tuple); |
893e093c | 402 | struct nf_conntrack_helper *cur; |
66e5a6b1 | 403 | int ret = 0, i; |
b8a7fe6c | 404 | |
6002f266 PM |
405 | BUG_ON(me->expect_policy == NULL); |
406 | BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); | |
af9d32ad | 407 | BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); |
7e5d03bb | 408 | |
92f73221 GF |
409 | if (me->expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
410 | return -EINVAL; | |
411 | ||
58a3c9bb | 412 | mutex_lock(&nf_ct_helper_mutex); |
66e5a6b1 LZ |
413 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
414 | hlist_for_each_entry(cur, &nf_ct_helper_hash[i], hnode) { | |
415 | if (!strcmp(cur->name, me->name) && | |
416 | (cur->tuple.src.l3num == NFPROTO_UNSPEC || | |
417 | cur->tuple.src.l3num == me->tuple.src.l3num) && | |
418 | cur->tuple.dst.protonum == me->tuple.dst.protonum) { | |
419 | ret = -EEXIST; | |
420 | goto out; | |
421 | } | |
422 | } | |
423 | } | |
424 | ||
425 | /* avoid unpredictable behaviour for auto_assign_helper */ | |
426 | if (!(me->flags & NF_CT_HELPER_F_USERSPACE)) { | |
427 | hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { | |
428 | if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, | |
429 | &mask)) { | |
430 | ret = -EEXIST; | |
431 | goto out; | |
432 | } | |
12f7a505 PNA |
433 | } |
434 | } | |
9338d7b4 | 435 | refcount_set(&me->refcnt, 1); |
58a3c9bb | 436 | hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]); |
b8a7fe6c | 437 | nf_ct_helper_count++; |
12f7a505 | 438 | out: |
58a3c9bb | 439 | mutex_unlock(&nf_ct_helper_mutex); |
12f7a505 | 440 | return ret; |
7e5d03bb | 441 | } |
13b18339 | 442 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_register); |
7e5d03bb | 443 | |
ac7b8483 | 444 | static bool expect_iter_me(struct nf_conntrack_expect *exp, void *data) |
7e5d03bb | 445 | { |
ac7b8483 FW |
446 | struct nf_conn_help *help = nfct_help(exp->master); |
447 | const struct nf_conntrack_helper *me = data; | |
448 | const struct nf_conntrack_helper *this; | |
449 | ||
450 | if (exp->helper == me) | |
451 | return true; | |
436a850d | 452 | |
ac7b8483 FW |
453 | this = rcu_dereference_protected(help->helper, |
454 | lockdep_is_held(&nf_conntrack_expect_lock)); | |
455 | return this == me; | |
456 | } | |
457 | ||
458 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) | |
459 | { | |
436a850d FW |
460 | mutex_lock(&nf_ct_helper_mutex); |
461 | hlist_del_rcu(&me->hnode); | |
462 | nf_ct_helper_count--; | |
463 | mutex_unlock(&nf_ct_helper_mutex); | |
464 | ||
465 | /* Make sure every nothing is still using the helper unless its a | |
466 | * connection in the hash. | |
467 | */ | |
468 | synchronize_rcu(); | |
7e5d03bb | 469 | |
ac7b8483 | 470 | nf_ct_expect_iterate_destroy(expect_iter_me, NULL); |
ff1acc49 | 471 | nf_ct_iterate_destroy(unhelp, me); |
ad9852af GF |
472 | |
473 | /* Maybe someone has gotten the helper already when unhelp above. | |
474 | * So need to wait it. | |
475 | */ | |
476 | synchronize_rcu(); | |
68047937 | 477 | } |
13b18339 | 478 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister); |
ceceae1b | 479 | |
82de0be6 GF |
480 | void nf_ct_helper_init(struct nf_conntrack_helper *helper, |
481 | u16 l3num, u16 protonum, const char *name, | |
482 | u16 default_port, u16 spec_port, u32 id, | |
483 | const struct nf_conntrack_expect_policy *exp_pol, | |
9f0f3ebe | 484 | u32 expect_class_max, |
82de0be6 GF |
485 | int (*help)(struct sk_buff *skb, unsigned int protoff, |
486 | struct nf_conn *ct, | |
487 | enum ip_conntrack_info ctinfo), | |
488 | int (*from_nlattr)(struct nlattr *attr, | |
489 | struct nf_conn *ct), | |
490 | struct module *module) | |
491 | { | |
492 | helper->tuple.src.l3num = l3num; | |
493 | helper->tuple.dst.protonum = protonum; | |
494 | helper->tuple.src.u.all = htons(spec_port); | |
495 | helper->expect_policy = exp_pol; | |
496 | helper->expect_class_max = expect_class_max; | |
82de0be6 GF |
497 | helper->help = help; |
498 | helper->from_nlattr = from_nlattr; | |
499 | helper->me = module; | |
08010a21 FL |
500 | snprintf(helper->nat_mod_name, sizeof(helper->nat_mod_name), |
501 | NF_NAT_HELPER_PREFIX "%s", name); | |
82de0be6 GF |
502 | |
503 | if (spec_port == default_port) | |
504 | snprintf(helper->name, sizeof(helper->name), "%s", name); | |
505 | else | |
506 | snprintf(helper->name, sizeof(helper->name), "%s-%u", name, id); | |
507 | } | |
508 | EXPORT_SYMBOL_GPL(nf_ct_helper_init); | |
509 | ||
510 | int nf_conntrack_helpers_register(struct nf_conntrack_helper *helper, | |
511 | unsigned int n) | |
512 | { | |
513 | unsigned int i; | |
514 | int err = 0; | |
515 | ||
516 | for (i = 0; i < n; i++) { | |
517 | err = nf_conntrack_helper_register(&helper[i]); | |
518 | if (err < 0) | |
519 | goto err; | |
520 | } | |
521 | ||
522 | return err; | |
523 | err: | |
524 | if (i > 0) | |
525 | nf_conntrack_helpers_unregister(helper, i); | |
526 | return err; | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_register); | |
529 | ||
530 | void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *helper, | |
531 | unsigned int n) | |
532 | { | |
533 | while (n-- > 0) | |
534 | nf_conntrack_helper_unregister(&helper[n]); | |
535 | } | |
536 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_unregister); | |
537 | ||
08010a21 FL |
538 | void nf_nat_helper_register(struct nf_conntrack_nat_helper *nat) |
539 | { | |
540 | mutex_lock(&nf_ct_nat_helpers_mutex); | |
541 | list_add_rcu(&nat->list, &nf_ct_nat_helpers); | |
542 | mutex_unlock(&nf_ct_nat_helpers_mutex); | |
543 | } | |
544 | EXPORT_SYMBOL_GPL(nf_nat_helper_register); | |
545 | ||
546 | void nf_nat_helper_unregister(struct nf_conntrack_nat_helper *nat) | |
547 | { | |
548 | mutex_lock(&nf_ct_nat_helpers_mutex); | |
549 | list_del_rcu(&nat->list); | |
550 | mutex_unlock(&nf_ct_nat_helpers_mutex); | |
551 | } | |
552 | EXPORT_SYMBOL_GPL(nf_nat_helper_unregister); | |
553 | ||
23f671a1 | 554 | static const struct nf_ct_ext_type helper_extend = { |
ceceae1b YK |
555 | .len = sizeof(struct nf_conn_help), |
556 | .align = __alignof__(struct nf_conn_help), | |
557 | .id = NF_CT_EXT_HELPER, | |
558 | }; | |
559 | ||
fc3893fd | 560 | void nf_conntrack_helper_pernet_init(struct net *net) |
ceceae1b | 561 | { |
a9006892 EL |
562 | net->ct.auto_assign_helper_warned = false; |
563 | net->ct.sysctl_auto_assign_helper = nf_ct_auto_assign_helper; | |
5e615b22 | 564 | } |
a9006892 | 565 | |
5e615b22 G |
566 | int nf_conntrack_helper_init(void) |
567 | { | |
568 | int ret; | |
569 | nf_ct_helper_hsize = 1; /* gets rounded up to use one page */ | |
570 | nf_ct_helper_hash = | |
571 | nf_ct_alloc_hashtable(&nf_ct_helper_hsize, 0); | |
572 | if (!nf_ct_helper_hash) | |
573 | return -ENOMEM; | |
574 | ||
575 | ret = nf_ct_extend_register(&helper_extend); | |
576 | if (ret < 0) { | |
577 | pr_err("nf_ct_helper: Unable to register helper extension.\n"); | |
578 | goto out_extend; | |
a9006892 EL |
579 | } |
580 | ||
08010a21 | 581 | INIT_LIST_HEAD(&nf_ct_nat_helpers); |
b8a7fe6c | 582 | return 0; |
5e615b22 | 583 | out_extend: |
285189c7 | 584 | kvfree(nf_ct_helper_hash); |
5e615b22 | 585 | return ret; |
ceceae1b YK |
586 | } |
587 | ||
5e615b22 | 588 | void nf_conntrack_helper_fini(void) |
ceceae1b | 589 | { |
5e615b22 | 590 | nf_ct_extend_unregister(&helper_extend); |
285189c7 | 591 | kvfree(nf_ct_helper_hash); |
ceceae1b | 592 | } |