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Commit | Line | Data |
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12f7a505 PNA |
1 | /* |
2 | * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation (or any later at your option). | |
7 | * | |
8 | * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com> | |
9 | */ | |
10 | #include <linux/init.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/rculist.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/list.h> | |
19 | #include <linux/errno.h> | |
20 | #include <net/netlink.h> | |
21 | #include <net/sock.h> | |
22 | ||
23 | #include <net/netfilter/nf_conntrack_helper.h> | |
24 | #include <net/netfilter/nf_conntrack_expect.h> | |
25 | #include <net/netfilter/nf_conntrack_ecache.h> | |
26 | ||
27 | #include <linux/netfilter/nfnetlink.h> | |
28 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
29 | #include <linux/netfilter/nfnetlink_cthelper.h> | |
30 | ||
31 | MODULE_LICENSE("GPL"); | |
32 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
33 | MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers"); | |
34 | ||
83d90219 LZ |
35 | struct nfnl_cthelper { |
36 | struct list_head list; | |
37 | struct nf_conntrack_helper helper; | |
38 | }; | |
39 | ||
40 | static LIST_HEAD(nfnl_cthelper_list); | |
41 | ||
12f7a505 PNA |
42 | static int |
43 | nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff, | |
44 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
45 | { | |
46 | const struct nf_conn_help *help; | |
47 | struct nf_conntrack_helper *helper; | |
48 | ||
49 | help = nfct_help(ct); | |
50 | if (help == NULL) | |
51 | return NF_DROP; | |
52 | ||
e2361cb9 | 53 | /* rcu_read_lock()ed by nf_hook_thresh */ |
12f7a505 PNA |
54 | helper = rcu_dereference(help->helper); |
55 | if (helper == NULL) | |
56 | return NF_DROP; | |
57 | ||
9332ef9d | 58 | /* This is a user-space helper not yet configured, skip. */ |
12f7a505 PNA |
59 | if ((helper->flags & |
60 | (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) == | |
61 | NF_CT_HELPER_F_USERSPACE) | |
62 | return NF_ACCEPT; | |
63 | ||
64 | /* If the user-space helper is not available, don't block traffic. */ | |
65 | return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS; | |
66 | } | |
67 | ||
68 | static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = { | |
69 | [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, }, | |
70 | [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, }, | |
71 | }; | |
72 | ||
73 | static int | |
74 | nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, | |
75 | const struct nlattr *attr) | |
76 | { | |
130ffbc2 | 77 | int err; |
12f7a505 PNA |
78 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; |
79 | ||
fceb6435 JB |
80 | err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, |
81 | nfnl_cthelper_tuple_pol, NULL); | |
130ffbc2 DB |
82 | if (err < 0) |
83 | return err; | |
12f7a505 PNA |
84 | |
85 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) | |
86 | return -EINVAL; | |
87 | ||
78146572 IW |
88 | /* Not all fields are initialized so first zero the tuple */ |
89 | memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); | |
90 | ||
fe31d1a8 | 91 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
12f7a505 PNA |
92 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | static int | |
98 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) | |
99 | { | |
b18c5d15 | 100 | struct nf_conn_help *help = nfct_help(ct); |
12f7a505 | 101 | |
7be54ca4 PNA |
102 | if (attr == NULL) |
103 | return -EINVAL; | |
104 | ||
12f7a505 PNA |
105 | if (help->helper->data_len == 0) |
106 | return -EINVAL; | |
107 | ||
b18c5d15 | 108 | memcpy(help->data, nla_data(attr), help->helper->data_len); |
12f7a505 PNA |
109 | return 0; |
110 | } | |
111 | ||
112 | static int | |
113 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) | |
114 | { | |
115 | const struct nf_conn_help *help = nfct_help(ct); | |
116 | ||
117 | if (help->helper->data_len && | |
118 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) | |
119 | goto nla_put_failure; | |
120 | ||
121 | return 0; | |
122 | ||
123 | nla_put_failure: | |
124 | return -ENOSPC; | |
125 | } | |
126 | ||
127 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { | |
128 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, | |
129 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
130 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, | |
131 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, | |
132 | }; | |
133 | ||
134 | static int | |
135 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, | |
136 | const struct nlattr *attr) | |
137 | { | |
130ffbc2 | 138 | int err; |
12f7a505 PNA |
139 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; |
140 | ||
fceb6435 JB |
141 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, |
142 | nfnl_cthelper_expect_pol, NULL); | |
130ffbc2 DB |
143 | if (err < 0) |
144 | return err; | |
12f7a505 PNA |
145 | |
146 | if (!tb[NFCTH_POLICY_NAME] || | |
147 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
148 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
149 | return -EINVAL; | |
150 | ||
151 | strncpy(expect_policy->name, | |
152 | nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); | |
153 | expect_policy->max_expected = | |
154 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
155 | expect_policy->timeout = | |
156 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | static const struct nla_policy | |
162 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
163 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
164 | }; | |
165 | ||
166 | static int | |
167 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
168 | const struct nlattr *attr) | |
169 | { | |
170 | int i, ret; | |
171 | struct nf_conntrack_expect_policy *expect_policy; | |
172 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
ae5c6821 | 173 | unsigned int class_max; |
12f7a505 | 174 | |
130ffbc2 | 175 | ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, |
fceb6435 | 176 | nfnl_cthelper_expect_policy_set, NULL); |
130ffbc2 DB |
177 | if (ret < 0) |
178 | return ret; | |
12f7a505 PNA |
179 | |
180 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
181 | return -EINVAL; | |
182 | ||
ae5c6821 LZ |
183 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); |
184 | if (class_max == 0) | |
185 | return -EINVAL; | |
186 | if (class_max > NF_CT_MAX_EXPECT_CLASSES) | |
12f7a505 PNA |
187 | return -EOVERFLOW; |
188 | ||
189 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * | |
ae5c6821 | 190 | class_max, GFP_KERNEL); |
12f7a505 PNA |
191 | if (expect_policy == NULL) |
192 | return -ENOMEM; | |
193 | ||
ae5c6821 | 194 | for (i = 0; i < class_max; i++) { |
12f7a505 PNA |
195 | if (!tb[NFCTH_POLICY_SET+i]) |
196 | goto err; | |
197 | ||
198 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
199 | tb[NFCTH_POLICY_SET+i]); | |
200 | if (ret < 0) | |
201 | goto err; | |
202 | } | |
ae5c6821 LZ |
203 | |
204 | helper->expect_class_max = class_max - 1; | |
12f7a505 PNA |
205 | helper->expect_policy = expect_policy; |
206 | return 0; | |
207 | err: | |
208 | kfree(expect_policy); | |
209 | return -EINVAL; | |
210 | } | |
211 | ||
212 | static int | |
213 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
214 | struct nf_conntrack_tuple *tuple) | |
215 | { | |
216 | struct nf_conntrack_helper *helper; | |
83d90219 | 217 | struct nfnl_cthelper *nfcth; |
12f7a505 PNA |
218 | int ret; |
219 | ||
220 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
221 | return -EINVAL; | |
222 | ||
83d90219 LZ |
223 | nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL); |
224 | if (nfcth == NULL) | |
12f7a505 | 225 | return -ENOMEM; |
83d90219 | 226 | helper = &nfcth->helper; |
12f7a505 PNA |
227 | |
228 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
229 | if (ret < 0) | |
f83bf8da | 230 | goto err1; |
12f7a505 PNA |
231 | |
232 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); | |
233 | helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); | |
234 | helper->flags |= NF_CT_HELPER_F_USERSPACE; | |
235 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
236 | ||
237 | helper->me = THIS_MODULE; | |
238 | helper->help = nfnl_userspace_cthelper; | |
239 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
240 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
241 | ||
242 | /* Default to queue number zero, this can be updated at any time. */ | |
243 | if (tb[NFCTH_QUEUE_NUM]) | |
244 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
245 | ||
246 | if (tb[NFCTH_STATUS]) { | |
247 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
248 | ||
249 | switch(status) { | |
250 | case NFCT_HELPER_STATUS_ENABLED: | |
251 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
252 | break; | |
253 | case NFCT_HELPER_STATUS_DISABLED: | |
254 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
255 | break; | |
256 | } | |
257 | } | |
258 | ||
259 | ret = nf_conntrack_helper_register(helper); | |
260 | if (ret < 0) | |
f83bf8da | 261 | goto err2; |
12f7a505 | 262 | |
83d90219 | 263 | list_add_tail(&nfcth->list, &nfnl_cthelper_list); |
12f7a505 | 264 | return 0; |
f83bf8da JC |
265 | err2: |
266 | kfree(helper->expect_policy); | |
267 | err1: | |
83d90219 | 268 | kfree(nfcth); |
12f7a505 PNA |
269 | return ret; |
270 | } | |
271 | ||
2c422257 PNA |
272 | static int |
273 | nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, | |
274 | struct nf_conntrack_expect_policy *new_policy, | |
275 | const struct nlattr *attr) | |
276 | { | |
277 | struct nlattr *tb[NFCTH_POLICY_MAX + 1]; | |
278 | int err; | |
279 | ||
280 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, | |
fceb6435 | 281 | nfnl_cthelper_expect_pol, NULL); |
2c422257 PNA |
282 | if (err < 0) |
283 | return err; | |
284 | ||
285 | if (!tb[NFCTH_POLICY_NAME] || | |
286 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
287 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
288 | return -EINVAL; | |
289 | ||
290 | if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) | |
291 | return -EBUSY; | |
292 | ||
293 | new_policy->max_expected = | |
294 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
295 | new_policy->timeout = | |
296 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
297 | ||
298 | return 0; | |
299 | } | |
300 | ||
301 | static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], | |
302 | struct nf_conntrack_helper *helper) | |
303 | { | |
304 | struct nf_conntrack_expect_policy new_policy[helper->expect_class_max + 1]; | |
305 | struct nf_conntrack_expect_policy *policy; | |
306 | int i, err; | |
307 | ||
308 | /* Check first that all policy attributes are well-formed, so we don't | |
309 | * leave things in inconsistent state on errors. | |
310 | */ | |
311 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
312 | ||
313 | if (!tb[NFCTH_POLICY_SET + i]) | |
314 | return -EINVAL; | |
315 | ||
316 | err = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], | |
317 | &new_policy[i], | |
318 | tb[NFCTH_POLICY_SET + i]); | |
319 | if (err < 0) | |
320 | return err; | |
321 | } | |
322 | /* Now we can safely update them. */ | |
323 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
324 | policy = (struct nf_conntrack_expect_policy *) | |
325 | &helper->expect_policy[i]; | |
326 | policy->max_expected = new_policy->max_expected; | |
327 | policy->timeout = new_policy->timeout; | |
328 | } | |
329 | ||
330 | return 0; | |
331 | } | |
332 | ||
333 | static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, | |
334 | const struct nlattr *attr) | |
335 | { | |
336 | struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; | |
337 | unsigned int class_max; | |
338 | int err; | |
339 | ||
340 | err = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, | |
fceb6435 | 341 | nfnl_cthelper_expect_policy_set, NULL); |
2c422257 PNA |
342 | if (err < 0) |
343 | return err; | |
344 | ||
345 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
346 | return -EINVAL; | |
347 | ||
348 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
349 | if (helper->expect_class_max + 1 != class_max) | |
350 | return -EBUSY; | |
351 | ||
352 | return nfnl_cthelper_update_policy_all(tb, helper); | |
353 | } | |
354 | ||
12f7a505 PNA |
355 | static int |
356 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
357 | struct nf_conntrack_helper *helper) | |
358 | { | |
359 | int ret; | |
360 | ||
361 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
362 | return -EBUSY; | |
363 | ||
364 | if (tb[NFCTH_POLICY]) { | |
2c422257 | 365 | ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]); |
12f7a505 PNA |
366 | if (ret < 0) |
367 | return ret; | |
368 | } | |
369 | if (tb[NFCTH_QUEUE_NUM]) | |
370 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
371 | ||
372 | if (tb[NFCTH_STATUS]) { | |
373 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
374 | ||
375 | switch(status) { | |
376 | case NFCT_HELPER_STATUS_ENABLED: | |
377 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
378 | break; | |
379 | case NFCT_HELPER_STATUS_DISABLED: | |
380 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
381 | break; | |
382 | } | |
383 | } | |
384 | return 0; | |
385 | } | |
386 | ||
7b8002a1 PNA |
387 | static int nfnl_cthelper_new(struct net *net, struct sock *nfnl, |
388 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
389 | const struct nlattr * const tb[]) | |
12f7a505 PNA |
390 | { |
391 | const char *helper_name; | |
392 | struct nf_conntrack_helper *cur, *helper = NULL; | |
393 | struct nf_conntrack_tuple tuple; | |
83d90219 LZ |
394 | struct nfnl_cthelper *nlcth; |
395 | int ret = 0; | |
12f7a505 PNA |
396 | |
397 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) | |
398 | return -EINVAL; | |
399 | ||
400 | helper_name = nla_data(tb[NFCTH_NAME]); | |
401 | ||
402 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
403 | if (ret < 0) | |
404 | return ret; | |
405 | ||
83d90219 LZ |
406 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
407 | cur = &nlcth->helper; | |
12f7a505 | 408 | |
83d90219 LZ |
409 | if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) |
410 | continue; | |
12f7a505 | 411 | |
83d90219 LZ |
412 | if ((tuple.src.l3num != cur->tuple.src.l3num || |
413 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
414 | continue; | |
12f7a505 | 415 | |
83d90219 LZ |
416 | if (nlh->nlmsg_flags & NLM_F_EXCL) |
417 | return -EEXIST; | |
12f7a505 | 418 | |
83d90219 LZ |
419 | helper = cur; |
420 | break; | |
12f7a505 | 421 | } |
12f7a505 PNA |
422 | |
423 | if (helper == NULL) | |
424 | ret = nfnl_cthelper_create(tb, &tuple); | |
425 | else | |
426 | ret = nfnl_cthelper_update(tb, helper); | |
427 | ||
428 | return ret; | |
12f7a505 PNA |
429 | } |
430 | ||
431 | static int | |
432 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
433 | struct nf_conntrack_helper *helper) | |
434 | { | |
435 | struct nlattr *nest_parms; | |
436 | ||
437 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
438 | if (nest_parms == NULL) | |
439 | goto nla_put_failure; | |
440 | ||
441 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
442 | htons(helper->tuple.src.l3num))) | |
443 | goto nla_put_failure; | |
444 | ||
445 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
446 | goto nla_put_failure; | |
447 | ||
448 | nla_nest_end(skb, nest_parms); | |
449 | return 0; | |
450 | ||
451 | nla_put_failure: | |
452 | return -1; | |
453 | } | |
454 | ||
455 | static int | |
456 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
457 | struct nf_conntrack_helper *helper) | |
458 | { | |
459 | int i; | |
460 | struct nlattr *nest_parms1, *nest_parms2; | |
461 | ||
462 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
463 | if (nest_parms1 == NULL) | |
464 | goto nla_put_failure; | |
465 | ||
466 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
ae5c6821 | 467 | htonl(helper->expect_class_max + 1))) |
12f7a505 PNA |
468 | goto nla_put_failure; |
469 | ||
ae5c6821 | 470 | for (i = 0; i < helper->expect_class_max + 1; i++) { |
12f7a505 PNA |
471 | nest_parms2 = nla_nest_start(skb, |
472 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
473 | if (nest_parms2 == NULL) | |
474 | goto nla_put_failure; | |
475 | ||
476 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
477 | helper->expect_policy[i].name)) | |
478 | goto nla_put_failure; | |
479 | ||
480 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
481 | htonl(helper->expect_policy[i].max_expected))) | |
482 | goto nla_put_failure; | |
483 | ||
484 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
485 | htonl(helper->expect_policy[i].timeout))) | |
486 | goto nla_put_failure; | |
487 | ||
488 | nla_nest_end(skb, nest_parms2); | |
489 | } | |
490 | nla_nest_end(skb, nest_parms1); | |
491 | return 0; | |
492 | ||
493 | nla_put_failure: | |
494 | return -1; | |
495 | } | |
496 | ||
497 | static int | |
15e47304 | 498 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
499 | int event, struct nf_conntrack_helper *helper) |
500 | { | |
501 | struct nlmsghdr *nlh; | |
502 | struct nfgenmsg *nfmsg; | |
15e47304 | 503 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
504 | int status; |
505 | ||
506 | event |= NFNL_SUBSYS_CTHELPER << 8; | |
15e47304 | 507 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
508 | if (nlh == NULL) |
509 | goto nlmsg_failure; | |
510 | ||
511 | nfmsg = nlmsg_data(nlh); | |
512 | nfmsg->nfgen_family = AF_UNSPEC; | |
513 | nfmsg->version = NFNETLINK_V0; | |
514 | nfmsg->res_id = 0; | |
515 | ||
516 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
517 | goto nla_put_failure; | |
518 | ||
519 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
520 | goto nla_put_failure; | |
521 | ||
522 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
523 | goto nla_put_failure; | |
524 | ||
525 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
526 | goto nla_put_failure; | |
527 | ||
528 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
529 | goto nla_put_failure; | |
530 | ||
531 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
532 | status = NFCT_HELPER_STATUS_ENABLED; | |
533 | else | |
534 | status = NFCT_HELPER_STATUS_DISABLED; | |
535 | ||
536 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
537 | goto nla_put_failure; | |
538 | ||
539 | nlmsg_end(skb, nlh); | |
540 | return skb->len; | |
541 | ||
542 | nlmsg_failure: | |
543 | nla_put_failure: | |
544 | nlmsg_cancel(skb, nlh); | |
545 | return -1; | |
546 | } | |
547 | ||
548 | static int | |
549 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
550 | { | |
551 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
552 | |
553 | rcu_read_lock(); | |
554 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
555 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
556 | restart: | |
b67bfe0d | 557 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
558 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
559 | ||
560 | /* skip non-userspace conntrack helpers. */ | |
561 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
562 | continue; | |
563 | ||
564 | if (cb->args[1]) { | |
565 | if (cur != last) | |
566 | continue; | |
567 | cb->args[1] = 0; | |
568 | } | |
569 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 570 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
571 | cb->nlh->nlmsg_seq, |
572 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
573 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
574 | cb->args[1] = (unsigned long)cur; | |
575 | goto out; | |
576 | } | |
577 | } | |
578 | } | |
579 | if (cb->args[1]) { | |
580 | cb->args[1] = 0; | |
581 | goto restart; | |
582 | } | |
583 | out: | |
584 | rcu_read_unlock(); | |
585 | return skb->len; | |
586 | } | |
587 | ||
7b8002a1 PNA |
588 | static int nfnl_cthelper_get(struct net *net, struct sock *nfnl, |
589 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
590 | const struct nlattr * const tb[]) | |
12f7a505 | 591 | { |
83d90219 | 592 | int ret = -ENOENT; |
12f7a505 | 593 | struct nf_conntrack_helper *cur; |
12f7a505 PNA |
594 | struct sk_buff *skb2; |
595 | char *helper_name = NULL; | |
596 | struct nf_conntrack_tuple tuple; | |
83d90219 | 597 | struct nfnl_cthelper *nlcth; |
12f7a505 PNA |
598 | bool tuple_set = false; |
599 | ||
600 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | |
601 | struct netlink_dump_control c = { | |
602 | .dump = nfnl_cthelper_dump_table, | |
603 | }; | |
604 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
605 | } | |
606 | ||
607 | if (tb[NFCTH_NAME]) | |
608 | helper_name = nla_data(tb[NFCTH_NAME]); | |
609 | ||
610 | if (tb[NFCTH_TUPLE]) { | |
611 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
612 | if (ret < 0) | |
613 | return ret; | |
614 | ||
615 | tuple_set = true; | |
616 | } | |
617 | ||
83d90219 LZ |
618 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
619 | cur = &nlcth->helper; | |
620 | if (helper_name && | |
621 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
622 | continue; | |
12f7a505 | 623 | |
83d90219 LZ |
624 | if (tuple_set && |
625 | (tuple.src.l3num != cur->tuple.src.l3num || | |
626 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
627 | continue; | |
12f7a505 | 628 | |
83d90219 LZ |
629 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
630 | if (skb2 == NULL) { | |
631 | ret = -ENOMEM; | |
632 | break; | |
633 | } | |
12f7a505 | 634 | |
83d90219 LZ |
635 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
636 | nlh->nlmsg_seq, | |
637 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
638 | NFNL_MSG_CTHELPER_NEW, cur); | |
639 | if (ret <= 0) { | |
640 | kfree_skb(skb2); | |
641 | break; | |
642 | } | |
12f7a505 | 643 | |
83d90219 LZ |
644 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
645 | MSG_DONTWAIT); | |
646 | if (ret > 0) | |
647 | ret = 0; | |
12f7a505 | 648 | |
83d90219 LZ |
649 | /* this avoids a loop in nfnetlink. */ |
650 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
12f7a505 PNA |
651 | } |
652 | return ret; | |
653 | } | |
654 | ||
7b8002a1 PNA |
655 | static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, |
656 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
657 | const struct nlattr * const tb[]) | |
12f7a505 PNA |
658 | { |
659 | char *helper_name = NULL; | |
660 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
661 | struct nf_conntrack_tuple tuple; |
662 | bool tuple_set = false, found = false; | |
83d90219 LZ |
663 | struct nfnl_cthelper *nlcth, *n; |
664 | int j = 0, ret; | |
12f7a505 PNA |
665 | |
666 | if (tb[NFCTH_NAME]) | |
667 | helper_name = nla_data(tb[NFCTH_NAME]); | |
668 | ||
669 | if (tb[NFCTH_TUPLE]) { | |
670 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
671 | if (ret < 0) | |
672 | return ret; | |
673 | ||
674 | tuple_set = true; | |
675 | } | |
676 | ||
83d90219 LZ |
677 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
678 | cur = &nlcth->helper; | |
679 | j++; | |
12f7a505 | 680 | |
83d90219 LZ |
681 | if (helper_name && |
682 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
683 | continue; | |
12f7a505 | 684 | |
83d90219 LZ |
685 | if (tuple_set && |
686 | (tuple.src.l3num != cur->tuple.src.l3num || | |
687 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
688 | continue; | |
12f7a505 | 689 | |
83d90219 LZ |
690 | found = true; |
691 | nf_conntrack_helper_unregister(cur); | |
692 | kfree(cur->expect_policy); | |
693 | ||
694 | list_del(&nlcth->list); | |
695 | kfree(nlcth); | |
12f7a505 | 696 | } |
83d90219 | 697 | |
12f7a505 PNA |
698 | /* Make sure we return success if we flush and there is no helpers */ |
699 | return (found || j == 0) ? 0 : -ENOENT; | |
700 | } | |
701 | ||
702 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
703 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
704 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
705 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
706 | }; | |
707 | ||
708 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
709 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
710 | .attr_count = NFCTH_MAX, | |
711 | .policy = nfnl_cthelper_policy }, | |
712 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
713 | .attr_count = NFCTH_MAX, | |
714 | .policy = nfnl_cthelper_policy }, | |
715 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
716 | .attr_count = NFCTH_MAX, | |
717 | .policy = nfnl_cthelper_policy }, | |
718 | }; | |
719 | ||
720 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
721 | .name = "cthelper", | |
722 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
723 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
724 | .cb = nfnl_cthelper_cb, | |
725 | }; | |
726 | ||
727 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
728 | ||
729 | static int __init nfnl_cthelper_init(void) | |
730 | { | |
731 | int ret; | |
732 | ||
733 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
734 | if (ret < 0) { | |
735 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
736 | goto err_out; | |
737 | } | |
738 | return 0; | |
739 | err_out: | |
740 | return ret; | |
741 | } | |
742 | ||
743 | static void __exit nfnl_cthelper_exit(void) | |
744 | { | |
745 | struct nf_conntrack_helper *cur; | |
83d90219 | 746 | struct nfnl_cthelper *nlcth, *n; |
12f7a505 PNA |
747 | |
748 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
749 | ||
83d90219 LZ |
750 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
751 | cur = &nlcth->helper; | |
12f7a505 | 752 | |
83d90219 LZ |
753 | nf_conntrack_helper_unregister(cur); |
754 | kfree(cur->expect_policy); | |
755 | kfree(nlcth); | |
12f7a505 PNA |
756 | } |
757 | } | |
758 | ||
759 | module_init(nfnl_cthelper_init); | |
760 | module_exit(nfnl_cthelper_exit); |