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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> | |
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 | ||
152 | strncpy(expect_policy->name, | |
153 | nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); | |
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 | ||
193 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * | |
ae5c6821 | 194 | class_max, GFP_KERNEL); |
12f7a505 PNA |
195 | if (expect_policy == NULL) |
196 | return -ENOMEM; | |
197 | ||
ae5c6821 | 198 | for (i = 0; i < class_max; i++) { |
12f7a505 PNA |
199 | if (!tb[NFCTH_POLICY_SET+i]) |
200 | goto err; | |
201 | ||
202 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
203 | tb[NFCTH_POLICY_SET+i]); | |
204 | if (ret < 0) | |
205 | goto err; | |
206 | } | |
ae5c6821 LZ |
207 | |
208 | helper->expect_class_max = class_max - 1; | |
12f7a505 PNA |
209 | helper->expect_policy = expect_policy; |
210 | return 0; | |
211 | err: | |
212 | kfree(expect_policy); | |
213 | return -EINVAL; | |
214 | } | |
215 | ||
216 | static int | |
217 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
218 | struct nf_conntrack_tuple *tuple) | |
219 | { | |
220 | struct nf_conntrack_helper *helper; | |
83d90219 | 221 | struct nfnl_cthelper *nfcth; |
157ffffe | 222 | unsigned int size; |
12f7a505 PNA |
223 | int ret; |
224 | ||
225 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
226 | return -EINVAL; | |
227 | ||
83d90219 LZ |
228 | nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL); |
229 | if (nfcth == NULL) | |
12f7a505 | 230 | return -ENOMEM; |
83d90219 | 231 | helper = &nfcth->helper; |
12f7a505 PNA |
232 | |
233 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
234 | if (ret < 0) | |
f83bf8da | 235 | goto err1; |
12f7a505 PNA |
236 | |
237 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); | |
157ffffe FW |
238 | size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); |
239 | if (size > FIELD_SIZEOF(struct nf_conn_help, data)) { | |
240 | ret = -ENOMEM; | |
241 | goto err2; | |
242 | } | |
243 | ||
12f7a505 PNA |
244 | helper->flags |= NF_CT_HELPER_F_USERSPACE; |
245 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
246 | ||
247 | helper->me = THIS_MODULE; | |
248 | helper->help = nfnl_userspace_cthelper; | |
249 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
250 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
251 | ||
252 | /* Default to queue number zero, this can be updated at any time. */ | |
253 | if (tb[NFCTH_QUEUE_NUM]) | |
254 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
255 | ||
256 | if (tb[NFCTH_STATUS]) { | |
257 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
258 | ||
259 | switch(status) { | |
260 | case NFCT_HELPER_STATUS_ENABLED: | |
261 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
262 | break; | |
263 | case NFCT_HELPER_STATUS_DISABLED: | |
264 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
265 | break; | |
266 | } | |
267 | } | |
268 | ||
269 | ret = nf_conntrack_helper_register(helper); | |
270 | if (ret < 0) | |
f83bf8da | 271 | goto err2; |
12f7a505 | 272 | |
83d90219 | 273 | list_add_tail(&nfcth->list, &nfnl_cthelper_list); |
12f7a505 | 274 | return 0; |
f83bf8da JC |
275 | err2: |
276 | kfree(helper->expect_policy); | |
277 | err1: | |
83d90219 | 278 | kfree(nfcth); |
12f7a505 PNA |
279 | return ret; |
280 | } | |
281 | ||
2c422257 PNA |
282 | static int |
283 | nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, | |
284 | struct nf_conntrack_expect_policy *new_policy, | |
285 | const struct nlattr *attr) | |
286 | { | |
287 | struct nlattr *tb[NFCTH_POLICY_MAX + 1]; | |
288 | int err; | |
289 | ||
290 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, | |
fceb6435 | 291 | nfnl_cthelper_expect_pol, NULL); |
2c422257 PNA |
292 | if (err < 0) |
293 | return err; | |
294 | ||
295 | if (!tb[NFCTH_POLICY_NAME] || | |
296 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
297 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
298 | return -EINVAL; | |
299 | ||
300 | if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) | |
301 | return -EBUSY; | |
302 | ||
303 | new_policy->max_expected = | |
304 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
305 | if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
306 | return -EINVAL; | |
307 | ||
2c422257 PNA |
308 | new_policy->timeout = |
309 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], | |
315 | struct nf_conntrack_helper *helper) | |
316 | { | |
317 | struct nf_conntrack_expect_policy new_policy[helper->expect_class_max + 1]; | |
318 | struct nf_conntrack_expect_policy *policy; | |
319 | int i, err; | |
320 | ||
321 | /* Check first that all policy attributes are well-formed, so we don't | |
322 | * leave things in inconsistent state on errors. | |
323 | */ | |
324 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
325 | ||
326 | if (!tb[NFCTH_POLICY_SET + i]) | |
327 | return -EINVAL; | |
328 | ||
329 | err = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], | |
330 | &new_policy[i], | |
331 | tb[NFCTH_POLICY_SET + i]); | |
332 | if (err < 0) | |
333 | return err; | |
334 | } | |
335 | /* Now we can safely update them. */ | |
336 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
337 | policy = (struct nf_conntrack_expect_policy *) | |
338 | &helper->expect_policy[i]; | |
339 | policy->max_expected = new_policy->max_expected; | |
340 | policy->timeout = new_policy->timeout; | |
341 | } | |
342 | ||
343 | return 0; | |
344 | } | |
345 | ||
346 | static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, | |
347 | const struct nlattr *attr) | |
348 | { | |
349 | struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; | |
350 | unsigned int class_max; | |
351 | int err; | |
352 | ||
353 | err = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, | |
fceb6435 | 354 | nfnl_cthelper_expect_policy_set, NULL); |
2c422257 PNA |
355 | if (err < 0) |
356 | return err; | |
357 | ||
358 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
359 | return -EINVAL; | |
360 | ||
361 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
362 | if (helper->expect_class_max + 1 != class_max) | |
363 | return -EBUSY; | |
364 | ||
365 | return nfnl_cthelper_update_policy_all(tb, helper); | |
366 | } | |
367 | ||
12f7a505 PNA |
368 | static int |
369 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
370 | struct nf_conntrack_helper *helper) | |
371 | { | |
372 | int ret; | |
373 | ||
374 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
375 | return -EBUSY; | |
376 | ||
377 | if (tb[NFCTH_POLICY]) { | |
2c422257 | 378 | ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]); |
12f7a505 PNA |
379 | if (ret < 0) |
380 | return ret; | |
381 | } | |
382 | if (tb[NFCTH_QUEUE_NUM]) | |
383 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
384 | ||
385 | if (tb[NFCTH_STATUS]) { | |
386 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
387 | ||
388 | switch(status) { | |
389 | case NFCT_HELPER_STATUS_ENABLED: | |
390 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
391 | break; | |
392 | case NFCT_HELPER_STATUS_DISABLED: | |
393 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
394 | break; | |
395 | } | |
396 | } | |
397 | return 0; | |
398 | } | |
399 | ||
7b8002a1 PNA |
400 | static int nfnl_cthelper_new(struct net *net, struct sock *nfnl, |
401 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
402 | const struct nlattr * const tb[], |
403 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
404 | { |
405 | const char *helper_name; | |
406 | struct nf_conntrack_helper *cur, *helper = NULL; | |
407 | struct nf_conntrack_tuple tuple; | |
83d90219 LZ |
408 | struct nfnl_cthelper *nlcth; |
409 | int ret = 0; | |
12f7a505 | 410 | |
4b380c42 KC |
411 | if (!capable(CAP_NET_ADMIN)) |
412 | return -EPERM; | |
413 | ||
12f7a505 PNA |
414 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) |
415 | return -EINVAL; | |
416 | ||
417 | helper_name = nla_data(tb[NFCTH_NAME]); | |
418 | ||
419 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
420 | if (ret < 0) | |
421 | return ret; | |
422 | ||
83d90219 LZ |
423 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
424 | cur = &nlcth->helper; | |
12f7a505 | 425 | |
83d90219 LZ |
426 | if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) |
427 | continue; | |
12f7a505 | 428 | |
83d90219 LZ |
429 | if ((tuple.src.l3num != cur->tuple.src.l3num || |
430 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
431 | continue; | |
12f7a505 | 432 | |
83d90219 LZ |
433 | if (nlh->nlmsg_flags & NLM_F_EXCL) |
434 | return -EEXIST; | |
12f7a505 | 435 | |
83d90219 LZ |
436 | helper = cur; |
437 | break; | |
12f7a505 | 438 | } |
12f7a505 PNA |
439 | |
440 | if (helper == NULL) | |
441 | ret = nfnl_cthelper_create(tb, &tuple); | |
442 | else | |
443 | ret = nfnl_cthelper_update(tb, helper); | |
444 | ||
445 | return ret; | |
12f7a505 PNA |
446 | } |
447 | ||
448 | static int | |
449 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
450 | struct nf_conntrack_helper *helper) | |
451 | { | |
452 | struct nlattr *nest_parms; | |
453 | ||
454 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
455 | if (nest_parms == NULL) | |
456 | goto nla_put_failure; | |
457 | ||
458 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
459 | htons(helper->tuple.src.l3num))) | |
460 | goto nla_put_failure; | |
461 | ||
462 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
463 | goto nla_put_failure; | |
464 | ||
465 | nla_nest_end(skb, nest_parms); | |
466 | return 0; | |
467 | ||
468 | nla_put_failure: | |
469 | return -1; | |
470 | } | |
471 | ||
472 | static int | |
473 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
474 | struct nf_conntrack_helper *helper) | |
475 | { | |
476 | int i; | |
477 | struct nlattr *nest_parms1, *nest_parms2; | |
478 | ||
479 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
480 | if (nest_parms1 == NULL) | |
481 | goto nla_put_failure; | |
482 | ||
483 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
ae5c6821 | 484 | htonl(helper->expect_class_max + 1))) |
12f7a505 PNA |
485 | goto nla_put_failure; |
486 | ||
ae5c6821 | 487 | for (i = 0; i < helper->expect_class_max + 1; i++) { |
12f7a505 PNA |
488 | nest_parms2 = nla_nest_start(skb, |
489 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
490 | if (nest_parms2 == NULL) | |
491 | goto nla_put_failure; | |
492 | ||
493 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
494 | helper->expect_policy[i].name)) | |
495 | goto nla_put_failure; | |
496 | ||
497 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
498 | htonl(helper->expect_policy[i].max_expected))) | |
499 | goto nla_put_failure; | |
500 | ||
501 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
502 | htonl(helper->expect_policy[i].timeout))) | |
503 | goto nla_put_failure; | |
504 | ||
505 | nla_nest_end(skb, nest_parms2); | |
506 | } | |
507 | nla_nest_end(skb, nest_parms1); | |
508 | return 0; | |
509 | ||
510 | nla_put_failure: | |
511 | return -1; | |
512 | } | |
513 | ||
514 | static int | |
15e47304 | 515 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
516 | int event, struct nf_conntrack_helper *helper) |
517 | { | |
518 | struct nlmsghdr *nlh; | |
519 | struct nfgenmsg *nfmsg; | |
15e47304 | 520 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
521 | int status; |
522 | ||
dedb67c4 | 523 | event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, event); |
15e47304 | 524 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
525 | if (nlh == NULL) |
526 | goto nlmsg_failure; | |
527 | ||
528 | nfmsg = nlmsg_data(nlh); | |
529 | nfmsg->nfgen_family = AF_UNSPEC; | |
530 | nfmsg->version = NFNETLINK_V0; | |
531 | nfmsg->res_id = 0; | |
532 | ||
533 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
534 | goto nla_put_failure; | |
535 | ||
536 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
537 | goto nla_put_failure; | |
538 | ||
539 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
540 | goto nla_put_failure; | |
541 | ||
542 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
543 | goto nla_put_failure; | |
544 | ||
545 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
546 | goto nla_put_failure; | |
547 | ||
548 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
549 | status = NFCT_HELPER_STATUS_ENABLED; | |
550 | else | |
551 | status = NFCT_HELPER_STATUS_DISABLED; | |
552 | ||
553 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
554 | goto nla_put_failure; | |
555 | ||
556 | nlmsg_end(skb, nlh); | |
557 | return skb->len; | |
558 | ||
559 | nlmsg_failure: | |
560 | nla_put_failure: | |
561 | nlmsg_cancel(skb, nlh); | |
562 | return -1; | |
563 | } | |
564 | ||
565 | static int | |
566 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
567 | { | |
568 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
569 | |
570 | rcu_read_lock(); | |
571 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
572 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
573 | restart: | |
b67bfe0d | 574 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
575 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
576 | ||
577 | /* skip non-userspace conntrack helpers. */ | |
578 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
579 | continue; | |
580 | ||
581 | if (cb->args[1]) { | |
582 | if (cur != last) | |
583 | continue; | |
584 | cb->args[1] = 0; | |
585 | } | |
586 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 587 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
588 | cb->nlh->nlmsg_seq, |
589 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
590 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
591 | cb->args[1] = (unsigned long)cur; | |
592 | goto out; | |
593 | } | |
594 | } | |
595 | } | |
596 | if (cb->args[1]) { | |
597 | cb->args[1] = 0; | |
598 | goto restart; | |
599 | } | |
600 | out: | |
601 | rcu_read_unlock(); | |
602 | return skb->len; | |
603 | } | |
604 | ||
7b8002a1 PNA |
605 | static int nfnl_cthelper_get(struct net *net, struct sock *nfnl, |
606 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
607 | const struct nlattr * const tb[], |
608 | struct netlink_ext_ack *extack) | |
12f7a505 | 609 | { |
83d90219 | 610 | int ret = -ENOENT; |
12f7a505 | 611 | struct nf_conntrack_helper *cur; |
12f7a505 PNA |
612 | struct sk_buff *skb2; |
613 | char *helper_name = NULL; | |
614 | struct nf_conntrack_tuple tuple; | |
83d90219 | 615 | struct nfnl_cthelper *nlcth; |
12f7a505 PNA |
616 | bool tuple_set = false; |
617 | ||
4b380c42 KC |
618 | if (!capable(CAP_NET_ADMIN)) |
619 | return -EPERM; | |
620 | ||
12f7a505 PNA |
621 | if (nlh->nlmsg_flags & NLM_F_DUMP) { |
622 | struct netlink_dump_control c = { | |
623 | .dump = nfnl_cthelper_dump_table, | |
624 | }; | |
625 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
626 | } | |
627 | ||
628 | if (tb[NFCTH_NAME]) | |
629 | helper_name = nla_data(tb[NFCTH_NAME]); | |
630 | ||
631 | if (tb[NFCTH_TUPLE]) { | |
632 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
633 | if (ret < 0) | |
634 | return ret; | |
635 | ||
636 | tuple_set = true; | |
637 | } | |
638 | ||
83d90219 LZ |
639 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
640 | cur = &nlcth->helper; | |
641 | if (helper_name && | |
642 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
643 | continue; | |
12f7a505 | 644 | |
83d90219 LZ |
645 | if (tuple_set && |
646 | (tuple.src.l3num != cur->tuple.src.l3num || | |
647 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
648 | continue; | |
12f7a505 | 649 | |
83d90219 LZ |
650 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
651 | if (skb2 == NULL) { | |
652 | ret = -ENOMEM; | |
653 | break; | |
654 | } | |
12f7a505 | 655 | |
83d90219 LZ |
656 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
657 | nlh->nlmsg_seq, | |
658 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
659 | NFNL_MSG_CTHELPER_NEW, cur); | |
660 | if (ret <= 0) { | |
661 | kfree_skb(skb2); | |
662 | break; | |
663 | } | |
12f7a505 | 664 | |
83d90219 LZ |
665 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
666 | MSG_DONTWAIT); | |
667 | if (ret > 0) | |
668 | ret = 0; | |
12f7a505 | 669 | |
83d90219 LZ |
670 | /* this avoids a loop in nfnetlink. */ |
671 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
12f7a505 PNA |
672 | } |
673 | return ret; | |
674 | } | |
675 | ||
7b8002a1 PNA |
676 | static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, |
677 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
678 | const struct nlattr * const tb[], |
679 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
680 | { |
681 | char *helper_name = NULL; | |
682 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
683 | struct nf_conntrack_tuple tuple; |
684 | bool tuple_set = false, found = false; | |
83d90219 LZ |
685 | struct nfnl_cthelper *nlcth, *n; |
686 | int j = 0, ret; | |
12f7a505 | 687 | |
4b380c42 KC |
688 | if (!capable(CAP_NET_ADMIN)) |
689 | return -EPERM; | |
690 | ||
12f7a505 PNA |
691 | if (tb[NFCTH_NAME]) |
692 | helper_name = nla_data(tb[NFCTH_NAME]); | |
693 | ||
694 | if (tb[NFCTH_TUPLE]) { | |
695 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
696 | if (ret < 0) | |
697 | return ret; | |
698 | ||
699 | tuple_set = true; | |
700 | } | |
701 | ||
9338d7b4 | 702 | ret = -ENOENT; |
83d90219 LZ |
703 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
704 | cur = &nlcth->helper; | |
705 | j++; | |
12f7a505 | 706 | |
83d90219 LZ |
707 | if (helper_name && |
708 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
709 | continue; | |
12f7a505 | 710 | |
83d90219 LZ |
711 | if (tuple_set && |
712 | (tuple.src.l3num != cur->tuple.src.l3num || | |
713 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
714 | continue; | |
12f7a505 | 715 | |
9338d7b4 LZ |
716 | if (refcount_dec_if_one(&cur->refcnt)) { |
717 | found = true; | |
718 | nf_conntrack_helper_unregister(cur); | |
719 | kfree(cur->expect_policy); | |
83d90219 | 720 | |
9338d7b4 LZ |
721 | list_del(&nlcth->list); |
722 | kfree(nlcth); | |
723 | } else { | |
724 | ret = -EBUSY; | |
725 | } | |
12f7a505 | 726 | } |
83d90219 | 727 | |
12f7a505 | 728 | /* Make sure we return success if we flush and there is no helpers */ |
9338d7b4 | 729 | return (found || j == 0) ? 0 : ret; |
12f7a505 PNA |
730 | } |
731 | ||
732 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
733 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
734 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
735 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
736 | }; | |
737 | ||
738 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
739 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
740 | .attr_count = NFCTH_MAX, | |
741 | .policy = nfnl_cthelper_policy }, | |
742 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
743 | .attr_count = NFCTH_MAX, | |
744 | .policy = nfnl_cthelper_policy }, | |
745 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
746 | .attr_count = NFCTH_MAX, | |
747 | .policy = nfnl_cthelper_policy }, | |
748 | }; | |
749 | ||
750 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
751 | .name = "cthelper", | |
752 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
753 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
754 | .cb = nfnl_cthelper_cb, | |
755 | }; | |
756 | ||
757 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
758 | ||
759 | static int __init nfnl_cthelper_init(void) | |
760 | { | |
761 | int ret; | |
762 | ||
763 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
764 | if (ret < 0) { | |
765 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
766 | goto err_out; | |
767 | } | |
768 | return 0; | |
769 | err_out: | |
770 | return ret; | |
771 | } | |
772 | ||
773 | static void __exit nfnl_cthelper_exit(void) | |
774 | { | |
775 | struct nf_conntrack_helper *cur; | |
83d90219 | 776 | struct nfnl_cthelper *nlcth, *n; |
12f7a505 PNA |
777 | |
778 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
779 | ||
83d90219 LZ |
780 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
781 | cur = &nlcth->helper; | |
12f7a505 | 782 | |
83d90219 LZ |
783 | nf_conntrack_helper_unregister(cur); |
784 | kfree(cur->expect_policy); | |
785 | kfree(nlcth); | |
12f7a505 PNA |
786 | } |
787 | } | |
788 | ||
789 | module_init(nfnl_cthelper_init); | |
790 | module_exit(nfnl_cthelper_exit); |