Commit | Line | Data |
---|---|---|
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> | |
4b380c42 | 20 | #include <linux/capability.h> |
12f7a505 PNA |
21 | #include <net/netlink.h> |
22 | #include <net/sock.h> | |
23 | ||
24 | #include <net/netfilter/nf_conntrack_helper.h> | |
25 | #include <net/netfilter/nf_conntrack_expect.h> | |
26 | #include <net/netfilter/nf_conntrack_ecache.h> | |
27 | ||
28 | #include <linux/netfilter/nfnetlink.h> | |
29 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
30 | #include <linux/netfilter/nfnetlink_cthelper.h> | |
31 | ||
32 | MODULE_LICENSE("GPL"); | |
33 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
34 | MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers"); | |
35 | ||
83d90219 LZ |
36 | struct nfnl_cthelper { |
37 | struct list_head list; | |
38 | struct nf_conntrack_helper helper; | |
39 | }; | |
40 | ||
41 | static LIST_HEAD(nfnl_cthelper_list); | |
42 | ||
12f7a505 PNA |
43 | static int |
44 | nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff, | |
45 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
46 | { | |
47 | const struct nf_conn_help *help; | |
48 | struct nf_conntrack_helper *helper; | |
49 | ||
50 | help = nfct_help(ct); | |
51 | if (help == NULL) | |
52 | return NF_DROP; | |
53 | ||
e2361cb9 | 54 | /* rcu_read_lock()ed by nf_hook_thresh */ |
12f7a505 PNA |
55 | helper = rcu_dereference(help->helper); |
56 | if (helper == NULL) | |
57 | return NF_DROP; | |
58 | ||
9332ef9d | 59 | /* This is a user-space helper not yet configured, skip. */ |
12f7a505 PNA |
60 | if ((helper->flags & |
61 | (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) == | |
62 | NF_CT_HELPER_F_USERSPACE) | |
63 | return NF_ACCEPT; | |
64 | ||
65 | /* If the user-space helper is not available, don't block traffic. */ | |
66 | return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS; | |
67 | } | |
68 | ||
69 | static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = { | |
70 | [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, }, | |
71 | [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, }, | |
72 | }; | |
73 | ||
74 | static int | |
75 | nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, | |
76 | const struct nlattr *attr) | |
77 | { | |
130ffbc2 | 78 | int err; |
12f7a505 PNA |
79 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; |
80 | ||
fceb6435 JB |
81 | err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, |
82 | nfnl_cthelper_tuple_pol, NULL); | |
130ffbc2 DB |
83 | if (err < 0) |
84 | return err; | |
12f7a505 PNA |
85 | |
86 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) | |
87 | return -EINVAL; | |
88 | ||
78146572 IW |
89 | /* Not all fields are initialized so first zero the tuple */ |
90 | memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); | |
91 | ||
fe31d1a8 | 92 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
12f7a505 PNA |
93 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | static int | |
99 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) | |
100 | { | |
b18c5d15 | 101 | struct nf_conn_help *help = nfct_help(ct); |
12f7a505 | 102 | |
7be54ca4 PNA |
103 | if (attr == NULL) |
104 | return -EINVAL; | |
105 | ||
12f7a505 PNA |
106 | if (help->helper->data_len == 0) |
107 | return -EINVAL; | |
108 | ||
157ffffe | 109 | nla_memcpy(help->data, nla_data(attr), sizeof(help->data)); |
12f7a505 PNA |
110 | return 0; |
111 | } | |
112 | ||
113 | static int | |
114 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) | |
115 | { | |
116 | const struct nf_conn_help *help = nfct_help(ct); | |
117 | ||
118 | if (help->helper->data_len && | |
119 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) | |
120 | goto nla_put_failure; | |
121 | ||
122 | return 0; | |
123 | ||
124 | nla_put_failure: | |
125 | return -ENOSPC; | |
126 | } | |
127 | ||
128 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { | |
129 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, | |
130 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
131 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, | |
132 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, | |
133 | }; | |
134 | ||
135 | static int | |
136 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, | |
137 | const struct nlattr *attr) | |
138 | { | |
130ffbc2 | 139 | int err; |
12f7a505 PNA |
140 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; |
141 | ||
fceb6435 JB |
142 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, |
143 | nfnl_cthelper_expect_pol, NULL); | |
130ffbc2 DB |
144 | if (err < 0) |
145 | return err; | |
12f7a505 PNA |
146 | |
147 | if (!tb[NFCTH_POLICY_NAME] || | |
148 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
149 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
150 | return -EINVAL; | |
151 | ||
4e09fc87 | 152 | nla_strlcpy(expect_policy->name, |
4b83a904 | 153 | tb[NFCTH_POLICY_NAME], NF_CT_HELPER_NAME_LEN); |
12f7a505 PNA |
154 | expect_policy->max_expected = |
155 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
156 | if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
157 | return -EINVAL; | |
158 | ||
12f7a505 PNA |
159 | expect_policy->timeout = |
160 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | static const struct nla_policy | |
166 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
167 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
168 | }; | |
169 | ||
170 | static int | |
171 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
172 | const struct nlattr *attr) | |
173 | { | |
174 | int i, ret; | |
175 | struct nf_conntrack_expect_policy *expect_policy; | |
176 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
ae5c6821 | 177 | unsigned int class_max; |
12f7a505 | 178 | |
130ffbc2 | 179 | ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, |
fceb6435 | 180 | nfnl_cthelper_expect_policy_set, NULL); |
130ffbc2 DB |
181 | if (ret < 0) |
182 | return ret; | |
12f7a505 PNA |
183 | |
184 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
185 | return -EINVAL; | |
186 | ||
ae5c6821 LZ |
187 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); |
188 | if (class_max == 0) | |
189 | return -EINVAL; | |
190 | if (class_max > NF_CT_MAX_EXPECT_CLASSES) | |
12f7a505 PNA |
191 | return -EOVERFLOW; |
192 | ||
6396bb22 KC |
193 | expect_policy = kcalloc(class_max, |
194 | sizeof(struct nf_conntrack_expect_policy), | |
195 | GFP_KERNEL); | |
12f7a505 PNA |
196 | if (expect_policy == NULL) |
197 | return -ENOMEM; | |
198 | ||
ae5c6821 | 199 | for (i = 0; i < class_max; i++) { |
12f7a505 PNA |
200 | if (!tb[NFCTH_POLICY_SET+i]) |
201 | goto err; | |
202 | ||
203 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
204 | tb[NFCTH_POLICY_SET+i]); | |
205 | if (ret < 0) | |
206 | goto err; | |
207 | } | |
ae5c6821 LZ |
208 | |
209 | helper->expect_class_max = class_max - 1; | |
12f7a505 PNA |
210 | helper->expect_policy = expect_policy; |
211 | return 0; | |
212 | err: | |
213 | kfree(expect_policy); | |
214 | return -EINVAL; | |
215 | } | |
216 | ||
217 | static int | |
218 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
219 | struct nf_conntrack_tuple *tuple) | |
220 | { | |
221 | struct nf_conntrack_helper *helper; | |
83d90219 | 222 | struct nfnl_cthelper *nfcth; |
157ffffe | 223 | unsigned int size; |
12f7a505 PNA |
224 | int ret; |
225 | ||
226 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
227 | return -EINVAL; | |
228 | ||
83d90219 LZ |
229 | nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL); |
230 | if (nfcth == NULL) | |
12f7a505 | 231 | return -ENOMEM; |
83d90219 | 232 | helper = &nfcth->helper; |
12f7a505 PNA |
233 | |
234 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
235 | if (ret < 0) | |
f83bf8da | 236 | goto err1; |
12f7a505 | 237 | |
4e09fc87 | 238 | nla_strlcpy(helper->name, |
4b83a904 | 239 | tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN); |
157ffffe FW |
240 | size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); |
241 | if (size > FIELD_SIZEOF(struct nf_conn_help, data)) { | |
242 | ret = -ENOMEM; | |
243 | goto err2; | |
244 | } | |
245 | ||
12f7a505 PNA |
246 | helper->flags |= NF_CT_HELPER_F_USERSPACE; |
247 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
248 | ||
249 | helper->me = THIS_MODULE; | |
250 | helper->help = nfnl_userspace_cthelper; | |
251 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
252 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
253 | ||
254 | /* Default to queue number zero, this can be updated at any time. */ | |
255 | if (tb[NFCTH_QUEUE_NUM]) | |
256 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
257 | ||
258 | if (tb[NFCTH_STATUS]) { | |
259 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
260 | ||
261 | switch(status) { | |
262 | case NFCT_HELPER_STATUS_ENABLED: | |
263 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
264 | break; | |
265 | case NFCT_HELPER_STATUS_DISABLED: | |
266 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
267 | break; | |
268 | } | |
269 | } | |
270 | ||
271 | ret = nf_conntrack_helper_register(helper); | |
272 | if (ret < 0) | |
f83bf8da | 273 | goto err2; |
12f7a505 | 274 | |
83d90219 | 275 | list_add_tail(&nfcth->list, &nfnl_cthelper_list); |
12f7a505 | 276 | return 0; |
f83bf8da JC |
277 | err2: |
278 | kfree(helper->expect_policy); | |
279 | err1: | |
83d90219 | 280 | kfree(nfcth); |
12f7a505 PNA |
281 | return ret; |
282 | } | |
283 | ||
2c422257 PNA |
284 | static int |
285 | nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, | |
286 | struct nf_conntrack_expect_policy *new_policy, | |
287 | const struct nlattr *attr) | |
288 | { | |
289 | struct nlattr *tb[NFCTH_POLICY_MAX + 1]; | |
290 | int err; | |
291 | ||
292 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, | |
fceb6435 | 293 | nfnl_cthelper_expect_pol, NULL); |
2c422257 PNA |
294 | if (err < 0) |
295 | return err; | |
296 | ||
297 | if (!tb[NFCTH_POLICY_NAME] || | |
298 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
299 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
300 | return -EINVAL; | |
301 | ||
302 | if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) | |
303 | return -EBUSY; | |
304 | ||
305 | new_policy->max_expected = | |
306 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
307 | if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
308 | return -EINVAL; | |
309 | ||
2c422257 PNA |
310 | new_policy->timeout = |
311 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
316 | static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], | |
317 | struct nf_conntrack_helper *helper) | |
318 | { | |
14463859 | 319 | struct nf_conntrack_expect_policy *new_policy; |
2c422257 | 320 | struct nf_conntrack_expect_policy *policy; |
14463859 GS |
321 | int i, ret = 0; |
322 | ||
323 | new_policy = kmalloc_array(helper->expect_class_max + 1, | |
324 | sizeof(*new_policy), GFP_KERNEL); | |
325 | if (!new_policy) | |
326 | return -ENOMEM; | |
2c422257 PNA |
327 | |
328 | /* Check first that all policy attributes are well-formed, so we don't | |
329 | * leave things in inconsistent state on errors. | |
330 | */ | |
331 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
332 | ||
14463859 GS |
333 | if (!tb[NFCTH_POLICY_SET + i]) { |
334 | ret = -EINVAL; | |
335 | goto err; | |
336 | } | |
2c422257 | 337 | |
14463859 | 338 | ret = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], |
2c422257 PNA |
339 | &new_policy[i], |
340 | tb[NFCTH_POLICY_SET + i]); | |
14463859 GS |
341 | if (ret < 0) |
342 | goto err; | |
2c422257 PNA |
343 | } |
344 | /* Now we can safely update them. */ | |
345 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
346 | policy = (struct nf_conntrack_expect_policy *) | |
347 | &helper->expect_policy[i]; | |
348 | policy->max_expected = new_policy->max_expected; | |
349 | policy->timeout = new_policy->timeout; | |
350 | } | |
351 | ||
14463859 GS |
352 | err: |
353 | kfree(new_policy); | |
354 | return ret; | |
2c422257 PNA |
355 | } |
356 | ||
357 | static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, | |
358 | const struct nlattr *attr) | |
359 | { | |
360 | struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; | |
361 | unsigned int class_max; | |
362 | int err; | |
363 | ||
364 | err = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, | |
fceb6435 | 365 | nfnl_cthelper_expect_policy_set, NULL); |
2c422257 PNA |
366 | if (err < 0) |
367 | return err; | |
368 | ||
369 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
370 | return -EINVAL; | |
371 | ||
372 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
373 | if (helper->expect_class_max + 1 != class_max) | |
374 | return -EBUSY; | |
375 | ||
376 | return nfnl_cthelper_update_policy_all(tb, helper); | |
377 | } | |
378 | ||
12f7a505 PNA |
379 | static int |
380 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
381 | struct nf_conntrack_helper *helper) | |
382 | { | |
383 | int ret; | |
384 | ||
385 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
386 | return -EBUSY; | |
387 | ||
388 | if (tb[NFCTH_POLICY]) { | |
2c422257 | 389 | ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]); |
12f7a505 PNA |
390 | if (ret < 0) |
391 | return ret; | |
392 | } | |
393 | if (tb[NFCTH_QUEUE_NUM]) | |
394 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
395 | ||
396 | if (tb[NFCTH_STATUS]) { | |
397 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
398 | ||
399 | switch(status) { | |
400 | case NFCT_HELPER_STATUS_ENABLED: | |
401 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
402 | break; | |
403 | case NFCT_HELPER_STATUS_DISABLED: | |
404 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
405 | break; | |
406 | } | |
407 | } | |
408 | return 0; | |
409 | } | |
410 | ||
7b8002a1 PNA |
411 | static int nfnl_cthelper_new(struct net *net, struct sock *nfnl, |
412 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
413 | const struct nlattr * const tb[], |
414 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
415 | { |
416 | const char *helper_name; | |
417 | struct nf_conntrack_helper *cur, *helper = NULL; | |
418 | struct nf_conntrack_tuple tuple; | |
83d90219 LZ |
419 | struct nfnl_cthelper *nlcth; |
420 | int ret = 0; | |
12f7a505 | 421 | |
4b380c42 KC |
422 | if (!capable(CAP_NET_ADMIN)) |
423 | return -EPERM; | |
424 | ||
12f7a505 PNA |
425 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) |
426 | return -EINVAL; | |
427 | ||
428 | helper_name = nla_data(tb[NFCTH_NAME]); | |
429 | ||
430 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
431 | if (ret < 0) | |
432 | return ret; | |
433 | ||
83d90219 LZ |
434 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
435 | cur = &nlcth->helper; | |
12f7a505 | 436 | |
83d90219 LZ |
437 | if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) |
438 | continue; | |
12f7a505 | 439 | |
83d90219 LZ |
440 | if ((tuple.src.l3num != cur->tuple.src.l3num || |
441 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
442 | continue; | |
12f7a505 | 443 | |
83d90219 LZ |
444 | if (nlh->nlmsg_flags & NLM_F_EXCL) |
445 | return -EEXIST; | |
12f7a505 | 446 | |
83d90219 LZ |
447 | helper = cur; |
448 | break; | |
12f7a505 | 449 | } |
12f7a505 PNA |
450 | |
451 | if (helper == NULL) | |
452 | ret = nfnl_cthelper_create(tb, &tuple); | |
453 | else | |
454 | ret = nfnl_cthelper_update(tb, helper); | |
455 | ||
456 | return ret; | |
12f7a505 PNA |
457 | } |
458 | ||
459 | static int | |
460 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
461 | struct nf_conntrack_helper *helper) | |
462 | { | |
463 | struct nlattr *nest_parms; | |
464 | ||
465 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
466 | if (nest_parms == NULL) | |
467 | goto nla_put_failure; | |
468 | ||
469 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
470 | htons(helper->tuple.src.l3num))) | |
471 | goto nla_put_failure; | |
472 | ||
473 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
474 | goto nla_put_failure; | |
475 | ||
476 | nla_nest_end(skb, nest_parms); | |
477 | return 0; | |
478 | ||
479 | nla_put_failure: | |
480 | return -1; | |
481 | } | |
482 | ||
483 | static int | |
484 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
485 | struct nf_conntrack_helper *helper) | |
486 | { | |
487 | int i; | |
488 | struct nlattr *nest_parms1, *nest_parms2; | |
489 | ||
490 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
491 | if (nest_parms1 == NULL) | |
492 | goto nla_put_failure; | |
493 | ||
494 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
ae5c6821 | 495 | htonl(helper->expect_class_max + 1))) |
12f7a505 PNA |
496 | goto nla_put_failure; |
497 | ||
ae5c6821 | 498 | for (i = 0; i < helper->expect_class_max + 1; i++) { |
12f7a505 PNA |
499 | nest_parms2 = nla_nest_start(skb, |
500 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
501 | if (nest_parms2 == NULL) | |
502 | goto nla_put_failure; | |
503 | ||
504 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
505 | helper->expect_policy[i].name)) | |
506 | goto nla_put_failure; | |
507 | ||
508 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
509 | htonl(helper->expect_policy[i].max_expected))) | |
510 | goto nla_put_failure; | |
511 | ||
512 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
513 | htonl(helper->expect_policy[i].timeout))) | |
514 | goto nla_put_failure; | |
515 | ||
516 | nla_nest_end(skb, nest_parms2); | |
517 | } | |
518 | nla_nest_end(skb, nest_parms1); | |
519 | return 0; | |
520 | ||
521 | nla_put_failure: | |
522 | return -1; | |
523 | } | |
524 | ||
525 | static int | |
15e47304 | 526 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
527 | int event, struct nf_conntrack_helper *helper) |
528 | { | |
529 | struct nlmsghdr *nlh; | |
530 | struct nfgenmsg *nfmsg; | |
15e47304 | 531 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
532 | int status; |
533 | ||
dedb67c4 | 534 | event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, event); |
15e47304 | 535 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
536 | if (nlh == NULL) |
537 | goto nlmsg_failure; | |
538 | ||
539 | nfmsg = nlmsg_data(nlh); | |
540 | nfmsg->nfgen_family = AF_UNSPEC; | |
541 | nfmsg->version = NFNETLINK_V0; | |
542 | nfmsg->res_id = 0; | |
543 | ||
544 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
545 | goto nla_put_failure; | |
546 | ||
547 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
548 | goto nla_put_failure; | |
549 | ||
550 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
551 | goto nla_put_failure; | |
552 | ||
553 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
554 | goto nla_put_failure; | |
555 | ||
556 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
557 | goto nla_put_failure; | |
558 | ||
559 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
560 | status = NFCT_HELPER_STATUS_ENABLED; | |
561 | else | |
562 | status = NFCT_HELPER_STATUS_DISABLED; | |
563 | ||
564 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
565 | goto nla_put_failure; | |
566 | ||
567 | nlmsg_end(skb, nlh); | |
568 | return skb->len; | |
569 | ||
570 | nlmsg_failure: | |
571 | nla_put_failure: | |
572 | nlmsg_cancel(skb, nlh); | |
573 | return -1; | |
574 | } | |
575 | ||
576 | static int | |
577 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
578 | { | |
579 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
580 | |
581 | rcu_read_lock(); | |
582 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
583 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
584 | restart: | |
b67bfe0d | 585 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
586 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
587 | ||
588 | /* skip non-userspace conntrack helpers. */ | |
589 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
590 | continue; | |
591 | ||
592 | if (cb->args[1]) { | |
593 | if (cur != last) | |
594 | continue; | |
595 | cb->args[1] = 0; | |
596 | } | |
597 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 598 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
599 | cb->nlh->nlmsg_seq, |
600 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
601 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
602 | cb->args[1] = (unsigned long)cur; | |
603 | goto out; | |
604 | } | |
605 | } | |
606 | } | |
607 | if (cb->args[1]) { | |
608 | cb->args[1] = 0; | |
609 | goto restart; | |
610 | } | |
611 | out: | |
612 | rcu_read_unlock(); | |
613 | return skb->len; | |
614 | } | |
615 | ||
7b8002a1 PNA |
616 | static int nfnl_cthelper_get(struct net *net, struct sock *nfnl, |
617 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
618 | const struct nlattr * const tb[], |
619 | struct netlink_ext_ack *extack) | |
12f7a505 | 620 | { |
83d90219 | 621 | int ret = -ENOENT; |
12f7a505 | 622 | struct nf_conntrack_helper *cur; |
12f7a505 PNA |
623 | struct sk_buff *skb2; |
624 | char *helper_name = NULL; | |
625 | struct nf_conntrack_tuple tuple; | |
83d90219 | 626 | struct nfnl_cthelper *nlcth; |
12f7a505 PNA |
627 | bool tuple_set = false; |
628 | ||
4b380c42 KC |
629 | if (!capable(CAP_NET_ADMIN)) |
630 | return -EPERM; | |
631 | ||
12f7a505 PNA |
632 | if (nlh->nlmsg_flags & NLM_F_DUMP) { |
633 | struct netlink_dump_control c = { | |
634 | .dump = nfnl_cthelper_dump_table, | |
635 | }; | |
636 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
637 | } | |
638 | ||
639 | if (tb[NFCTH_NAME]) | |
640 | helper_name = nla_data(tb[NFCTH_NAME]); | |
641 | ||
642 | if (tb[NFCTH_TUPLE]) { | |
643 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
644 | if (ret < 0) | |
645 | return ret; | |
646 | ||
647 | tuple_set = true; | |
648 | } | |
649 | ||
83d90219 LZ |
650 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
651 | cur = &nlcth->helper; | |
652 | if (helper_name && | |
653 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
654 | continue; | |
12f7a505 | 655 | |
83d90219 LZ |
656 | if (tuple_set && |
657 | (tuple.src.l3num != cur->tuple.src.l3num || | |
658 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
659 | continue; | |
12f7a505 | 660 | |
83d90219 LZ |
661 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
662 | if (skb2 == NULL) { | |
663 | ret = -ENOMEM; | |
664 | break; | |
665 | } | |
12f7a505 | 666 | |
83d90219 LZ |
667 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
668 | nlh->nlmsg_seq, | |
669 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
670 | NFNL_MSG_CTHELPER_NEW, cur); | |
671 | if (ret <= 0) { | |
672 | kfree_skb(skb2); | |
673 | break; | |
674 | } | |
12f7a505 | 675 | |
83d90219 LZ |
676 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
677 | MSG_DONTWAIT); | |
678 | if (ret > 0) | |
679 | ret = 0; | |
12f7a505 | 680 | |
83d90219 LZ |
681 | /* this avoids a loop in nfnetlink. */ |
682 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
12f7a505 PNA |
683 | } |
684 | return ret; | |
685 | } | |
686 | ||
7b8002a1 PNA |
687 | static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, |
688 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
689 | const struct nlattr * const tb[], |
690 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
691 | { |
692 | char *helper_name = NULL; | |
693 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
694 | struct nf_conntrack_tuple tuple; |
695 | bool tuple_set = false, found = false; | |
83d90219 LZ |
696 | struct nfnl_cthelper *nlcth, *n; |
697 | int j = 0, ret; | |
12f7a505 | 698 | |
4b380c42 KC |
699 | if (!capable(CAP_NET_ADMIN)) |
700 | return -EPERM; | |
701 | ||
12f7a505 PNA |
702 | if (tb[NFCTH_NAME]) |
703 | helper_name = nla_data(tb[NFCTH_NAME]); | |
704 | ||
705 | if (tb[NFCTH_TUPLE]) { | |
706 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
707 | if (ret < 0) | |
708 | return ret; | |
709 | ||
710 | tuple_set = true; | |
711 | } | |
712 | ||
9338d7b4 | 713 | ret = -ENOENT; |
83d90219 LZ |
714 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
715 | cur = &nlcth->helper; | |
716 | j++; | |
12f7a505 | 717 | |
83d90219 LZ |
718 | if (helper_name && |
719 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
720 | continue; | |
12f7a505 | 721 | |
83d90219 LZ |
722 | if (tuple_set && |
723 | (tuple.src.l3num != cur->tuple.src.l3num || | |
724 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
725 | continue; | |
12f7a505 | 726 | |
9338d7b4 LZ |
727 | if (refcount_dec_if_one(&cur->refcnt)) { |
728 | found = true; | |
729 | nf_conntrack_helper_unregister(cur); | |
730 | kfree(cur->expect_policy); | |
83d90219 | 731 | |
9338d7b4 LZ |
732 | list_del(&nlcth->list); |
733 | kfree(nlcth); | |
734 | } else { | |
735 | ret = -EBUSY; | |
736 | } | |
12f7a505 | 737 | } |
83d90219 | 738 | |
12f7a505 | 739 | /* Make sure we return success if we flush and there is no helpers */ |
9338d7b4 | 740 | return (found || j == 0) ? 0 : ret; |
12f7a505 PNA |
741 | } |
742 | ||
743 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
744 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
745 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
746 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
747 | }; | |
748 | ||
749 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
750 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
751 | .attr_count = NFCTH_MAX, | |
752 | .policy = nfnl_cthelper_policy }, | |
753 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
754 | .attr_count = NFCTH_MAX, | |
755 | .policy = nfnl_cthelper_policy }, | |
756 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
757 | .attr_count = NFCTH_MAX, | |
758 | .policy = nfnl_cthelper_policy }, | |
759 | }; | |
760 | ||
761 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
762 | .name = "cthelper", | |
763 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
764 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
765 | .cb = nfnl_cthelper_cb, | |
766 | }; | |
767 | ||
768 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
769 | ||
770 | static int __init nfnl_cthelper_init(void) | |
771 | { | |
772 | int ret; | |
773 | ||
774 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
775 | if (ret < 0) { | |
776 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
777 | goto err_out; | |
778 | } | |
779 | return 0; | |
780 | err_out: | |
781 | return ret; | |
782 | } | |
783 | ||
784 | static void __exit nfnl_cthelper_exit(void) | |
785 | { | |
786 | struct nf_conntrack_helper *cur; | |
83d90219 | 787 | struct nfnl_cthelper *nlcth, *n; |
12f7a505 PNA |
788 | |
789 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
790 | ||
83d90219 LZ |
791 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
792 | cur = &nlcth->helper; | |
12f7a505 | 793 | |
83d90219 LZ |
794 | nf_conntrack_helper_unregister(cur); |
795 | kfree(cur->expect_policy); | |
796 | kfree(nlcth); | |
12f7a505 PNA |
797 | } |
798 | } | |
799 | ||
800 | module_init(nfnl_cthelper_init); | |
801 | module_exit(nfnl_cthelper_exit); |