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Commit | Line | Data |
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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 MJ |
26 | #include <net/netfilter/nf_conntrack.h> |
27 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
605dcad6 | 28 | #include <net/netfilter/nf_conntrack_l4proto.h> |
7e5d03bb MJ |
29 | #include <net/netfilter/nf_conntrack_helper.h> |
30 | #include <net/netfilter/nf_conntrack_core.h> | |
ceceae1b | 31 | #include <net/netfilter/nf_conntrack_extend.h> |
b20ab9cc | 32 | #include <net/netfilter/nf_log.h> |
7e5d03bb | 33 | |
58a3c9bb | 34 | static DEFINE_MUTEX(nf_ct_helper_mutex); |
12f7a505 PNA |
35 | struct hlist_head *nf_ct_helper_hash __read_mostly; |
36 | EXPORT_SYMBOL_GPL(nf_ct_helper_hash); | |
37 | unsigned int nf_ct_helper_hsize __read_mostly; | |
38 | EXPORT_SYMBOL_GPL(nf_ct_helper_hsize); | |
b8a7fe6c | 39 | static unsigned int nf_ct_helper_count __read_mostly; |
b8a7fe6c | 40 | |
3bb398d9 | 41 | static bool nf_ct_auto_assign_helper __read_mostly = false; |
a9006892 EL |
42 | module_param_named(nf_conntrack_helper, nf_ct_auto_assign_helper, bool, 0644); |
43 | MODULE_PARM_DESC(nf_conntrack_helper, | |
3bb398d9 | 44 | "Enable automatic conntrack helper assignment (default 0)"); |
a9006892 EL |
45 | |
46 | #ifdef CONFIG_SYSCTL | |
47 | static struct ctl_table helper_sysctl_table[] = { | |
48 | { | |
49 | .procname = "nf_conntrack_helper", | |
50 | .data = &init_net.ct.sysctl_auto_assign_helper, | |
51 | .maxlen = sizeof(unsigned int), | |
52 | .mode = 0644, | |
53 | .proc_handler = proc_dointvec, | |
54 | }, | |
55 | {} | |
56 | }; | |
57 | ||
58 | static int nf_conntrack_helper_init_sysctl(struct net *net) | |
59 | { | |
60 | struct ctl_table *table; | |
61 | ||
62 | table = kmemdup(helper_sysctl_table, sizeof(helper_sysctl_table), | |
63 | GFP_KERNEL); | |
64 | if (!table) | |
65 | goto out; | |
66 | ||
67 | table[0].data = &net->ct.sysctl_auto_assign_helper; | |
68 | ||
464dc801 EB |
69 | /* Don't export sysctls to unprivileged users */ |
70 | if (net->user_ns != &init_user_ns) | |
71 | table[0].procname = NULL; | |
72 | ||
a9006892 EL |
73 | net->ct.helper_sysctl_header = |
74 | register_net_sysctl(net, "net/netfilter", table); | |
75 | ||
76 | if (!net->ct.helper_sysctl_header) { | |
77 | pr_err("nf_conntrack_helper: can't register to sysctl.\n"); | |
78 | goto out_register; | |
79 | } | |
80 | return 0; | |
81 | ||
82 | out_register: | |
83 | kfree(table); | |
84 | out: | |
85 | return -ENOMEM; | |
86 | } | |
87 | ||
88 | static void nf_conntrack_helper_fini_sysctl(struct net *net) | |
89 | { | |
90 | struct ctl_table *table; | |
91 | ||
92 | table = net->ct.helper_sysctl_header->ctl_table_arg; | |
93 | unregister_net_sysctl_table(net->ct.helper_sysctl_header); | |
94 | kfree(table); | |
95 | } | |
96 | #else | |
97 | static int nf_conntrack_helper_init_sysctl(struct net *net) | |
98 | { | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static void nf_conntrack_helper_fini_sysctl(struct net *net) | |
103 | { | |
104 | } | |
105 | #endif /* CONFIG_SYSCTL */ | |
b8a7fe6c PM |
106 | |
107 | /* Stupid hash, but collision free for the default registrations of the | |
108 | * helpers currently in the kernel. */ | |
109 | static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) | |
110 | { | |
111 | return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^ | |
a34c4589 | 112 | (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize; |
b8a7fe6c | 113 | } |
7e5d03bb | 114 | |
226c0c0e | 115 | static struct nf_conntrack_helper * |
7e5d03bb MJ |
116 | __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) |
117 | { | |
b8a7fe6c | 118 | struct nf_conntrack_helper *helper; |
d4156e8c | 119 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
b8a7fe6c | 120 | unsigned int h; |
7e5d03bb | 121 | |
b8a7fe6c PM |
122 | if (!nf_ct_helper_count) |
123 | return NULL; | |
124 | ||
125 | h = helper_hash(tuple); | |
b67bfe0d | 126 | hlist_for_each_entry_rcu(helper, &nf_ct_helper_hash[h], hnode) { |
b8a7fe6c PM |
127 | if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask)) |
128 | return helper; | |
7e5d03bb MJ |
129 | } |
130 | return NULL; | |
131 | } | |
7e5d03bb MJ |
132 | |
133 | struct nf_conntrack_helper * | |
794e6871 | 134 | __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum) |
7e5d03bb MJ |
135 | { |
136 | struct nf_conntrack_helper *h; | |
b8a7fe6c | 137 | unsigned int i; |
7e5d03bb | 138 | |
b8a7fe6c | 139 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
b67bfe0d | 140 | hlist_for_each_entry_rcu(h, &nf_ct_helper_hash[i], hnode) { |
6114cc51 FW |
141 | if (strcmp(h->name, name)) |
142 | continue; | |
143 | ||
144 | if (h->tuple.src.l3num != NFPROTO_UNSPEC && | |
145 | h->tuple.src.l3num != l3num) | |
146 | continue; | |
147 | ||
148 | if (h->tuple.dst.protonum == protonum) | |
b8a7fe6c PM |
149 | return h; |
150 | } | |
7e5d03bb | 151 | } |
7e5d03bb MJ |
152 | return NULL; |
153 | } | |
794e6871 | 154 | EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find); |
7e5d03bb | 155 | |
84f3bb9a PM |
156 | struct nf_conntrack_helper * |
157 | nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum) | |
158 | { | |
159 | struct nf_conntrack_helper *h; | |
160 | ||
8b5995d0 GF |
161 | rcu_read_lock(); |
162 | ||
84f3bb9a PM |
163 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
164 | #ifdef CONFIG_MODULES | |
165 | if (h == NULL) { | |
8b5995d0 GF |
166 | rcu_read_unlock(); |
167 | if (request_module("nfct-helper-%s", name) == 0) { | |
168 | rcu_read_lock(); | |
84f3bb9a | 169 | h = __nf_conntrack_helper_find(name, l3num, protonum); |
8b5995d0 GF |
170 | } else { |
171 | return h; | |
172 | } | |
84f3bb9a PM |
173 | } |
174 | #endif | |
175 | if (h != NULL && !try_module_get(h->me)) | |
176 | h = NULL; | |
9338d7b4 LZ |
177 | if (h != NULL && !refcount_inc_not_zero(&h->refcnt)) { |
178 | module_put(h->me); | |
179 | h = NULL; | |
180 | } | |
84f3bb9a | 181 | |
8b5995d0 GF |
182 | rcu_read_unlock(); |
183 | ||
84f3bb9a PM |
184 | return h; |
185 | } | |
186 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get); | |
187 | ||
d91fc59c LZ |
188 | void nf_conntrack_helper_put(struct nf_conntrack_helper *helper) |
189 | { | |
9338d7b4 | 190 | refcount_dec(&helper->refcnt); |
d91fc59c LZ |
191 | module_put(helper->me); |
192 | } | |
193 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_put); | |
194 | ||
1afc5679 PNA |
195 | struct nf_conn_help * |
196 | nf_ct_helper_ext_add(struct nf_conn *ct, | |
197 | struct nf_conntrack_helper *helper, gfp_t gfp) | |
b560580a PM |
198 | { |
199 | struct nf_conn_help *help; | |
200 | ||
9f0f3ebe | 201 | help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp); |
b560580a PM |
202 | if (help) |
203 | INIT_HLIST_HEAD(&help->expectations); | |
204 | else | |
205 | pr_debug("failed to add helper extension area"); | |
206 | return help; | |
207 | } | |
208 | EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add); | |
209 | ||
dfe75ff8 JK |
210 | static struct nf_conntrack_helper * |
211 | nf_ct_lookup_helper(struct nf_conn *ct, struct net *net) | |
212 | { | |
213 | if (!net->ct.sysctl_auto_assign_helper) { | |
214 | if (net->ct.auto_assign_helper_warned) | |
215 | return NULL; | |
216 | if (!__nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple)) | |
217 | return NULL; | |
218 | pr_info("nf_conntrack: default automatic helper assignment " | |
219 | "has been turned off for security reasons and CT-based " | |
220 | " firewall rule not found. Use the iptables CT target " | |
221 | "to attach helpers instead.\n"); | |
222 | net->ct.auto_assign_helper_warned = 1; | |
223 | return NULL; | |
224 | } | |
225 | ||
226 | return __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
227 | } | |
228 | ||
229 | ||
b2a15a60 PM |
230 | int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, |
231 | gfp_t flags) | |
226c0c0e | 232 | { |
b2a15a60 PM |
233 | struct nf_conntrack_helper *helper = NULL; |
234 | struct nf_conn_help *help; | |
a9006892 | 235 | struct net *net = nf_ct_net(ct); |
226c0c0e | 236 | |
6714cf54 PNA |
237 | /* We already got a helper explicitly attached. The function |
238 | * nf_conntrack_alter_reply - in case NAT is in use - asks for looking | |
239 | * the helper up again. Since now the user is in full control of | |
240 | * making consistent helper configurations, skip this automatic | |
241 | * re-lookup, otherwise we'll lose the helper. | |
242 | */ | |
243 | if (test_bit(IPS_HELPER_BIT, &ct->status)) | |
244 | return 0; | |
245 | ||
b2a15a60 PM |
246 | if (tmpl != NULL) { |
247 | help = nfct_help(tmpl); | |
6714cf54 | 248 | if (help != NULL) { |
b2a15a60 | 249 | helper = help->helper; |
6714cf54 PNA |
250 | set_bit(IPS_HELPER_BIT, &ct->status); |
251 | } | |
b2a15a60 PM |
252 | } |
253 | ||
254 | help = nfct_help(ct); | |
a9006892 | 255 | |
226c0c0e | 256 | if (helper == NULL) { |
dfe75ff8 JK |
257 | helper = nf_ct_lookup_helper(ct, net); |
258 | if (helper == NULL) { | |
259 | if (help) | |
260 | RCU_INIT_POINTER(help->helper, NULL); | |
261 | return 0; | |
262 | } | |
226c0c0e PNA |
263 | } |
264 | ||
265 | if (help == NULL) { | |
1afc5679 | 266 | help = nf_ct_helper_ext_add(ct, helper, flags); |
cf71c03e PN |
267 | if (help == NULL) |
268 | return -ENOMEM; | |
226c0c0e | 269 | } else { |
32f53760 PNA |
270 | /* We only allow helper re-assignment of the same sort since |
271 | * we cannot reallocate the helper extension area. | |
272 | */ | |
6e2f0aa8 FW |
273 | struct nf_conntrack_helper *tmp = rcu_dereference(help->helper); |
274 | ||
275 | if (tmp && tmp->help != helper->help) { | |
32f53760 | 276 | RCU_INIT_POINTER(help->helper, NULL); |
cf71c03e | 277 | return 0; |
32f53760 | 278 | } |
226c0c0e PNA |
279 | } |
280 | ||
cf778b00 | 281 | rcu_assign_pointer(help->helper, helper); |
cf71c03e PN |
282 | |
283 | return 0; | |
226c0c0e PNA |
284 | } |
285 | EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper); | |
286 | ||
01cfa0a4 | 287 | /* appropriate ct lock protecting must be taken by caller */ |
ff1acc49 | 288 | static int unhelp(struct nf_conn *ct, void *me) |
7e5d03bb | 289 | { |
7e5d03bb MJ |
290 | struct nf_conn_help *help = nfct_help(ct); |
291 | ||
ca7433df | 292 | if (help && rcu_dereference_raw(help->helper) == me) { |
7e5d03bb | 293 | nf_conntrack_event(IPCT_HELPER, ct); |
a9b3cd7f | 294 | RCU_INIT_POINTER(help->helper, NULL); |
7e5d03bb | 295 | } |
ff1acc49 LZ |
296 | |
297 | /* We are not intended to delete this conntrack. */ | |
7e5d03bb MJ |
298 | return 0; |
299 | } | |
300 | ||
9858a3ae PNA |
301 | void nf_ct_helper_destroy(struct nf_conn *ct) |
302 | { | |
303 | struct nf_conn_help *help = nfct_help(ct); | |
304 | struct nf_conntrack_helper *helper; | |
305 | ||
306 | if (help) { | |
307 | rcu_read_lock(); | |
308 | helper = rcu_dereference(help->helper); | |
309 | if (helper && helper->destroy) | |
310 | helper->destroy(ct); | |
311 | rcu_read_unlock(); | |
312 | } | |
313 | } | |
314 | ||
544d5c7d PNA |
315 | static LIST_HEAD(nf_ct_helper_expectfn_list); |
316 | ||
317 | void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n) | |
318 | { | |
ca7433df | 319 | spin_lock_bh(&nf_conntrack_expect_lock); |
544d5c7d | 320 | list_add_rcu(&n->head, &nf_ct_helper_expectfn_list); |
ca7433df | 321 | spin_unlock_bh(&nf_conntrack_expect_lock); |
544d5c7d PNA |
322 | } |
323 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_register); | |
324 | ||
325 | void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n) | |
326 | { | |
ca7433df | 327 | spin_lock_bh(&nf_conntrack_expect_lock); |
544d5c7d | 328 | list_del_rcu(&n->head); |
ca7433df | 329 | spin_unlock_bh(&nf_conntrack_expect_lock); |
544d5c7d PNA |
330 | } |
331 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister); | |
332 | ||
8b5995d0 | 333 | /* Caller should hold the rcu lock */ |
544d5c7d PNA |
334 | struct nf_ct_helper_expectfn * |
335 | nf_ct_helper_expectfn_find_by_name(const char *name) | |
336 | { | |
337 | struct nf_ct_helper_expectfn *cur; | |
338 | bool found = false; | |
339 | ||
544d5c7d PNA |
340 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
341 | if (!strcmp(cur->name, name)) { | |
342 | found = true; | |
343 | break; | |
344 | } | |
345 | } | |
544d5c7d PNA |
346 | return found ? cur : NULL; |
347 | } | |
348 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name); | |
349 | ||
8b5995d0 | 350 | /* Caller should hold the rcu lock */ |
544d5c7d PNA |
351 | struct nf_ct_helper_expectfn * |
352 | nf_ct_helper_expectfn_find_by_symbol(const void *symbol) | |
353 | { | |
354 | struct nf_ct_helper_expectfn *cur; | |
355 | bool found = false; | |
356 | ||
544d5c7d PNA |
357 | list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) { |
358 | if (cur->expectfn == symbol) { | |
359 | found = true; | |
360 | break; | |
361 | } | |
362 | } | |
544d5c7d PNA |
363 | return found ? cur : NULL; |
364 | } | |
365 | EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol); | |
366 | ||
b20ab9cc PNA |
367 | __printf(3, 4) |
368 | void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, | |
369 | const char *fmt, ...) | |
370 | { | |
371 | const struct nf_conn_help *help; | |
372 | const struct nf_conntrack_helper *helper; | |
f9caed59 JP |
373 | struct va_format vaf; |
374 | va_list args; | |
375 | ||
376 | va_start(args, fmt); | |
377 | ||
378 | vaf.fmt = fmt; | |
379 | vaf.va = &args; | |
b20ab9cc PNA |
380 | |
381 | /* Called from the helper function, this call never fails */ | |
382 | help = nfct_help(ct); | |
383 | ||
e2361cb9 | 384 | /* rcu_read_lock()ed by nf_hook_thresh */ |
b20ab9cc PNA |
385 | helper = rcu_dereference(help->helper); |
386 | ||
30e0c6a6 | 387 | nf_log_packet(nf_ct_net(ct), nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL, |
f9caed59 JP |
388 | "nf_ct_%s: dropping packet: %pV ", helper->name, &vaf); |
389 | ||
390 | va_end(args); | |
b20ab9cc PNA |
391 | } |
392 | EXPORT_SYMBOL_GPL(nf_ct_helper_log); | |
393 | ||
7e5d03bb MJ |
394 | int nf_conntrack_helper_register(struct nf_conntrack_helper *me) |
395 | { | |
893e093c | 396 | struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) }; |
b8a7fe6c | 397 | unsigned int h = helper_hash(&me->tuple); |
893e093c | 398 | struct nf_conntrack_helper *cur; |
66e5a6b1 | 399 | int ret = 0, i; |
b8a7fe6c | 400 | |
6002f266 PM |
401 | BUG_ON(me->expect_policy == NULL); |
402 | BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); | |
af9d32ad | 403 | BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); |
7e5d03bb | 404 | |
92f73221 GF |
405 | if (me->expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
406 | return -EINVAL; | |
407 | ||
58a3c9bb | 408 | mutex_lock(&nf_ct_helper_mutex); |
66e5a6b1 LZ |
409 | for (i = 0; i < nf_ct_helper_hsize; i++) { |
410 | hlist_for_each_entry(cur, &nf_ct_helper_hash[i], hnode) { | |
411 | if (!strcmp(cur->name, me->name) && | |
412 | (cur->tuple.src.l3num == NFPROTO_UNSPEC || | |
413 | cur->tuple.src.l3num == me->tuple.src.l3num) && | |
414 | cur->tuple.dst.protonum == me->tuple.dst.protonum) { | |
415 | ret = -EEXIST; | |
416 | goto out; | |
417 | } | |
418 | } | |
419 | } | |
420 | ||
421 | /* avoid unpredictable behaviour for auto_assign_helper */ | |
422 | if (!(me->flags & NF_CT_HELPER_F_USERSPACE)) { | |
423 | hlist_for_each_entry(cur, &nf_ct_helper_hash[h], hnode) { | |
424 | if (nf_ct_tuple_src_mask_cmp(&cur->tuple, &me->tuple, | |
425 | &mask)) { | |
426 | ret = -EEXIST; | |
427 | goto out; | |
428 | } | |
12f7a505 PNA |
429 | } |
430 | } | |
9338d7b4 | 431 | refcount_set(&me->refcnt, 1); |
58a3c9bb | 432 | hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]); |
b8a7fe6c | 433 | nf_ct_helper_count++; |
12f7a505 | 434 | out: |
58a3c9bb | 435 | mutex_unlock(&nf_ct_helper_mutex); |
12f7a505 | 436 | return ret; |
7e5d03bb | 437 | } |
13b18339 | 438 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_register); |
7e5d03bb | 439 | |
436a850d | 440 | void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) |
7e5d03bb | 441 | { |
31f15875 | 442 | struct nf_conntrack_expect *exp; |
b67bfe0d | 443 | const struct hlist_node *next; |
31f15875 | 444 | unsigned int i; |
436a850d FW |
445 | |
446 | mutex_lock(&nf_ct_helper_mutex); | |
447 | hlist_del_rcu(&me->hnode); | |
448 | nf_ct_helper_count--; | |
449 | mutex_unlock(&nf_ct_helper_mutex); | |
450 | ||
451 | /* Make sure every nothing is still using the helper unless its a | |
452 | * connection in the hash. | |
453 | */ | |
454 | synchronize_rcu(); | |
7e5d03bb | 455 | |
7e5d03bb | 456 | /* Get rid of expectations */ |
ca7433df | 457 | spin_lock_bh(&nf_conntrack_expect_lock); |
31f15875 | 458 | for (i = 0; i < nf_ct_expect_hsize; i++) { |
b67bfe0d | 459 | hlist_for_each_entry_safe(exp, next, |
0a93aaed | 460 | &nf_ct_expect_hash[i], hnode) { |
31f15875 | 461 | struct nf_conn_help *help = nfct_help(exp->master); |
c5d277d2 ED |
462 | if ((rcu_dereference_protected( |
463 | help->helper, | |
ca7433df | 464 | lockdep_is_held(&nf_conntrack_expect_lock) |
ec0e3f01 GF |
465 | ) == me || exp->helper == me)) |
466 | nf_ct_remove_expect(exp); | |
7e5d03bb MJ |
467 | } |
468 | } | |
ca7433df | 469 | spin_unlock_bh(&nf_conntrack_expect_lock); |
7e5d03bb | 470 | |
ff1acc49 | 471 | nf_ct_iterate_destroy(unhelp, me); |
68047937 | 472 | } |
13b18339 | 473 | EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister); |
ceceae1b | 474 | |
82de0be6 GF |
475 | void nf_ct_helper_init(struct nf_conntrack_helper *helper, |
476 | u16 l3num, u16 protonum, const char *name, | |
477 | u16 default_port, u16 spec_port, u32 id, | |
478 | const struct nf_conntrack_expect_policy *exp_pol, | |
9f0f3ebe | 479 | u32 expect_class_max, |
82de0be6 GF |
480 | int (*help)(struct sk_buff *skb, unsigned int protoff, |
481 | struct nf_conn *ct, | |
482 | enum ip_conntrack_info ctinfo), | |
483 | int (*from_nlattr)(struct nlattr *attr, | |
484 | struct nf_conn *ct), | |
485 | struct module *module) | |
486 | { | |
487 | helper->tuple.src.l3num = l3num; | |
488 | helper->tuple.dst.protonum = protonum; | |
489 | helper->tuple.src.u.all = htons(spec_port); | |
490 | helper->expect_policy = exp_pol; | |
491 | helper->expect_class_max = expect_class_max; | |
82de0be6 GF |
492 | helper->help = help; |
493 | helper->from_nlattr = from_nlattr; | |
494 | helper->me = module; | |
495 | ||
496 | if (spec_port == default_port) | |
497 | snprintf(helper->name, sizeof(helper->name), "%s", name); | |
498 | else | |
499 | snprintf(helper->name, sizeof(helper->name), "%s-%u", name, id); | |
500 | } | |
501 | EXPORT_SYMBOL_GPL(nf_ct_helper_init); | |
502 | ||
503 | int nf_conntrack_helpers_register(struct nf_conntrack_helper *helper, | |
504 | unsigned int n) | |
505 | { | |
506 | unsigned int i; | |
507 | int err = 0; | |
508 | ||
509 | for (i = 0; i < n; i++) { | |
510 | err = nf_conntrack_helper_register(&helper[i]); | |
511 | if (err < 0) | |
512 | goto err; | |
513 | } | |
514 | ||
515 | return err; | |
516 | err: | |
517 | if (i > 0) | |
518 | nf_conntrack_helpers_unregister(helper, i); | |
519 | return err; | |
520 | } | |
521 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_register); | |
522 | ||
523 | void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *helper, | |
524 | unsigned int n) | |
525 | { | |
526 | while (n-- > 0) | |
527 | nf_conntrack_helper_unregister(&helper[n]); | |
528 | } | |
529 | EXPORT_SYMBOL_GPL(nf_conntrack_helpers_unregister); | |
530 | ||
23f671a1 | 531 | static const struct nf_ct_ext_type helper_extend = { |
ceceae1b YK |
532 | .len = sizeof(struct nf_conn_help), |
533 | .align = __alignof__(struct nf_conn_help), | |
534 | .id = NF_CT_EXT_HELPER, | |
535 | }; | |
536 | ||
5e615b22 | 537 | int nf_conntrack_helper_pernet_init(struct net *net) |
ceceae1b | 538 | { |
a9006892 EL |
539 | net->ct.auto_assign_helper_warned = false; |
540 | net->ct.sysctl_auto_assign_helper = nf_ct_auto_assign_helper; | |
5e615b22 G |
541 | return nf_conntrack_helper_init_sysctl(net); |
542 | } | |
b8a7fe6c | 543 | |
5e615b22 G |
544 | void nf_conntrack_helper_pernet_fini(struct net *net) |
545 | { | |
546 | nf_conntrack_helper_fini_sysctl(net); | |
547 | } | |
a9006892 | 548 | |
5e615b22 G |
549 | int nf_conntrack_helper_init(void) |
550 | { | |
551 | int ret; | |
552 | nf_ct_helper_hsize = 1; /* gets rounded up to use one page */ | |
553 | nf_ct_helper_hash = | |
554 | nf_ct_alloc_hashtable(&nf_ct_helper_hsize, 0); | |
555 | if (!nf_ct_helper_hash) | |
556 | return -ENOMEM; | |
557 | ||
558 | ret = nf_ct_extend_register(&helper_extend); | |
559 | if (ret < 0) { | |
560 | pr_err("nf_ct_helper: Unable to register helper extension.\n"); | |
561 | goto out_extend; | |
a9006892 EL |
562 | } |
563 | ||
b8a7fe6c | 564 | return 0; |
5e615b22 | 565 | out_extend: |
d862a662 | 566 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize); |
5e615b22 | 567 | return ret; |
ceceae1b YK |
568 | } |
569 | ||
5e615b22 | 570 | void nf_conntrack_helper_fini(void) |
ceceae1b | 571 | { |
5e615b22 G |
572 | nf_ct_extend_unregister(&helper_extend); |
573 | nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize); | |
ceceae1b | 574 | } |