Commit | Line | Data |
---|---|---|
e97150df | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
12f7a505 PNA |
2 | /* |
3 | * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org> | |
4 | * | |
12f7a505 PNA |
5 | * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com> |
6 | */ | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/netlink.h> | |
12 | #include <linux/rculist.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/list.h> | |
16 | #include <linux/errno.h> | |
4b380c42 | 17 | #include <linux/capability.h> |
12f7a505 PNA |
18 | #include <net/netlink.h> |
19 | #include <net/sock.h> | |
20 | ||
21 | #include <net/netfilter/nf_conntrack_helper.h> | |
22 | #include <net/netfilter/nf_conntrack_expect.h> | |
23 | #include <net/netfilter/nf_conntrack_ecache.h> | |
24 | ||
25 | #include <linux/netfilter/nfnetlink.h> | |
26 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
27 | #include <linux/netfilter/nfnetlink_cthelper.h> | |
28 | ||
29 | MODULE_LICENSE("GPL"); | |
30 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
31 | MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers"); | |
32 | ||
83d90219 LZ |
33 | struct nfnl_cthelper { |
34 | struct list_head list; | |
35 | struct nf_conntrack_helper helper; | |
36 | }; | |
37 | ||
38 | static LIST_HEAD(nfnl_cthelper_list); | |
39 | ||
12f7a505 PNA |
40 | static int |
41 | nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff, | |
42 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
43 | { | |
44 | const struct nf_conn_help *help; | |
45 | struct nf_conntrack_helper *helper; | |
46 | ||
47 | help = nfct_help(ct); | |
48 | if (help == NULL) | |
49 | return NF_DROP; | |
50 | ||
e2361cb9 | 51 | /* rcu_read_lock()ed by nf_hook_thresh */ |
12f7a505 PNA |
52 | helper = rcu_dereference(help->helper); |
53 | if (helper == NULL) | |
54 | return NF_DROP; | |
55 | ||
9332ef9d | 56 | /* This is a user-space helper not yet configured, skip. */ |
12f7a505 PNA |
57 | if ((helper->flags & |
58 | (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) == | |
59 | NF_CT_HELPER_F_USERSPACE) | |
60 | return NF_ACCEPT; | |
61 | ||
62 | /* If the user-space helper is not available, don't block traffic. */ | |
63 | return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS; | |
64 | } | |
65 | ||
66 | static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = { | |
67 | [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, }, | |
68 | [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, }, | |
69 | }; | |
70 | ||
71 | static int | |
72 | nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, | |
73 | const struct nlattr *attr) | |
74 | { | |
130ffbc2 | 75 | int err; |
12f7a505 PNA |
76 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; |
77 | ||
8cb08174 JB |
78 | err = nla_parse_nested_deprecated(tb, NFCTH_TUPLE_MAX, attr, |
79 | nfnl_cthelper_tuple_pol, NULL); | |
130ffbc2 DB |
80 | if (err < 0) |
81 | return err; | |
12f7a505 PNA |
82 | |
83 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) | |
84 | return -EINVAL; | |
85 | ||
78146572 IW |
86 | /* Not all fields are initialized so first zero the tuple */ |
87 | memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); | |
88 | ||
fe31d1a8 | 89 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
12f7a505 PNA |
90 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | static int | |
96 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) | |
97 | { | |
b18c5d15 | 98 | struct nf_conn_help *help = nfct_help(ct); |
12f7a505 | 99 | |
7be54ca4 PNA |
100 | if (attr == NULL) |
101 | return -EINVAL; | |
102 | ||
12f7a505 PNA |
103 | if (help->helper->data_len == 0) |
104 | return -EINVAL; | |
105 | ||
703acd70 | 106 | nla_memcpy(help->data, attr, sizeof(help->data)); |
12f7a505 PNA |
107 | return 0; |
108 | } | |
109 | ||
110 | static int | |
111 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) | |
112 | { | |
113 | const struct nf_conn_help *help = nfct_help(ct); | |
114 | ||
115 | if (help->helper->data_len && | |
116 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) | |
117 | goto nla_put_failure; | |
118 | ||
119 | return 0; | |
120 | ||
121 | nla_put_failure: | |
122 | return -ENOSPC; | |
123 | } | |
124 | ||
125 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { | |
126 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, | |
127 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
128 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, | |
129 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, | |
130 | }; | |
131 | ||
132 | static int | |
133 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, | |
134 | const struct nlattr *attr) | |
135 | { | |
130ffbc2 | 136 | int err; |
12f7a505 PNA |
137 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; |
138 | ||
8cb08174 JB |
139 | err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr, |
140 | nfnl_cthelper_expect_pol, NULL); | |
130ffbc2 DB |
141 | if (err < 0) |
142 | return err; | |
12f7a505 PNA |
143 | |
144 | if (!tb[NFCTH_POLICY_NAME] || | |
145 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
146 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
147 | return -EINVAL; | |
148 | ||
4e09fc87 | 149 | nla_strlcpy(expect_policy->name, |
4b83a904 | 150 | tb[NFCTH_POLICY_NAME], NF_CT_HELPER_NAME_LEN); |
12f7a505 PNA |
151 | expect_policy->max_expected = |
152 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
153 | if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
154 | return -EINVAL; | |
155 | ||
12f7a505 PNA |
156 | expect_policy->timeout = |
157 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
162 | static const struct nla_policy | |
163 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
164 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
165 | }; | |
166 | ||
167 | static int | |
168 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
169 | const struct nlattr *attr) | |
170 | { | |
171 | int i, ret; | |
172 | struct nf_conntrack_expect_policy *expect_policy; | |
173 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
ae5c6821 | 174 | unsigned int class_max; |
12f7a505 | 175 | |
8cb08174 JB |
176 | ret = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr, |
177 | nfnl_cthelper_expect_policy_set, | |
178 | NULL); | |
130ffbc2 DB |
179 | if (ret < 0) |
180 | return ret; | |
12f7a505 PNA |
181 | |
182 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
183 | return -EINVAL; | |
184 | ||
ae5c6821 LZ |
185 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); |
186 | if (class_max == 0) | |
187 | return -EINVAL; | |
188 | if (class_max > NF_CT_MAX_EXPECT_CLASSES) | |
12f7a505 PNA |
189 | return -EOVERFLOW; |
190 | ||
6396bb22 KC |
191 | expect_policy = kcalloc(class_max, |
192 | sizeof(struct nf_conntrack_expect_policy), | |
193 | GFP_KERNEL); | |
12f7a505 PNA |
194 | if (expect_policy == NULL) |
195 | return -ENOMEM; | |
196 | ||
ae5c6821 | 197 | for (i = 0; i < class_max; i++) { |
12f7a505 PNA |
198 | if (!tb[NFCTH_POLICY_SET+i]) |
199 | goto err; | |
200 | ||
201 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
202 | tb[NFCTH_POLICY_SET+i]); | |
203 | if (ret < 0) | |
204 | goto err; | |
205 | } | |
ae5c6821 LZ |
206 | |
207 | helper->expect_class_max = class_max - 1; | |
12f7a505 PNA |
208 | helper->expect_policy = expect_policy; |
209 | return 0; | |
210 | err: | |
211 | kfree(expect_policy); | |
212 | return -EINVAL; | |
213 | } | |
214 | ||
215 | static int | |
216 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
217 | struct nf_conntrack_tuple *tuple) | |
218 | { | |
219 | struct nf_conntrack_helper *helper; | |
83d90219 | 220 | struct nfnl_cthelper *nfcth; |
157ffffe | 221 | unsigned int size; |
12f7a505 PNA |
222 | int ret; |
223 | ||
224 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
225 | return -EINVAL; | |
226 | ||
83d90219 LZ |
227 | nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL); |
228 | if (nfcth == NULL) | |
12f7a505 | 229 | return -ENOMEM; |
83d90219 | 230 | helper = &nfcth->helper; |
12f7a505 PNA |
231 | |
232 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
233 | if (ret < 0) | |
f83bf8da | 234 | goto err1; |
12f7a505 | 235 | |
4e09fc87 | 236 | nla_strlcpy(helper->name, |
4b83a904 | 237 | tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN); |
157ffffe | 238 | size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); |
c593642c | 239 | if (size > sizeof_field(struct nf_conn_help, data)) { |
157ffffe FW |
240 | ret = -ENOMEM; |
241 | goto err2; | |
242 | } | |
703acd70 | 243 | helper->data_len = size; |
157ffffe | 244 | |
12f7a505 PNA |
245 | helper->flags |= NF_CT_HELPER_F_USERSPACE; |
246 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
247 | ||
248 | helper->me = THIS_MODULE; | |
249 | helper->help = nfnl_userspace_cthelper; | |
250 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
251 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
252 | ||
253 | /* Default to queue number zero, this can be updated at any time. */ | |
254 | if (tb[NFCTH_QUEUE_NUM]) | |
255 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
256 | ||
257 | if (tb[NFCTH_STATUS]) { | |
258 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
259 | ||
260 | switch(status) { | |
261 | case NFCT_HELPER_STATUS_ENABLED: | |
262 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
263 | break; | |
264 | case NFCT_HELPER_STATUS_DISABLED: | |
265 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
266 | break; | |
267 | } | |
268 | } | |
269 | ||
270 | ret = nf_conntrack_helper_register(helper); | |
271 | if (ret < 0) | |
f83bf8da | 272 | goto err2; |
12f7a505 | 273 | |
83d90219 | 274 | list_add_tail(&nfcth->list, &nfnl_cthelper_list); |
12f7a505 | 275 | return 0; |
f83bf8da JC |
276 | err2: |
277 | kfree(helper->expect_policy); | |
278 | err1: | |
83d90219 | 279 | kfree(nfcth); |
12f7a505 PNA |
280 | return ret; |
281 | } | |
282 | ||
2c422257 PNA |
283 | static int |
284 | nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, | |
285 | struct nf_conntrack_expect_policy *new_policy, | |
286 | const struct nlattr *attr) | |
287 | { | |
288 | struct nlattr *tb[NFCTH_POLICY_MAX + 1]; | |
289 | int err; | |
290 | ||
8cb08174 JB |
291 | err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr, |
292 | nfnl_cthelper_expect_pol, NULL); | |
2c422257 PNA |
293 | if (err < 0) |
294 | return err; | |
295 | ||
296 | if (!tb[NFCTH_POLICY_NAME] || | |
297 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
298 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
299 | return -EINVAL; | |
300 | ||
301 | if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) | |
302 | return -EBUSY; | |
303 | ||
304 | new_policy->max_expected = | |
305 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
306 | if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
307 | return -EINVAL; | |
308 | ||
2c422257 PNA |
309 | new_policy->timeout = |
310 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
315 | static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], | |
316 | struct nf_conntrack_helper *helper) | |
317 | { | |
14463859 | 318 | struct nf_conntrack_expect_policy *new_policy; |
2c422257 | 319 | struct nf_conntrack_expect_policy *policy; |
14463859 GS |
320 | int i, ret = 0; |
321 | ||
322 | new_policy = kmalloc_array(helper->expect_class_max + 1, | |
323 | sizeof(*new_policy), GFP_KERNEL); | |
324 | if (!new_policy) | |
325 | return -ENOMEM; | |
2c422257 PNA |
326 | |
327 | /* Check first that all policy attributes are well-formed, so we don't | |
328 | * leave things in inconsistent state on errors. | |
329 | */ | |
330 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
331 | ||
14463859 GS |
332 | if (!tb[NFCTH_POLICY_SET + i]) { |
333 | ret = -EINVAL; | |
334 | goto err; | |
335 | } | |
2c422257 | 336 | |
14463859 | 337 | ret = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], |
2c422257 PNA |
338 | &new_policy[i], |
339 | tb[NFCTH_POLICY_SET + i]); | |
14463859 GS |
340 | if (ret < 0) |
341 | goto err; | |
2c422257 PNA |
342 | } |
343 | /* Now we can safely update them. */ | |
344 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
345 | policy = (struct nf_conntrack_expect_policy *) | |
346 | &helper->expect_policy[i]; | |
347 | policy->max_expected = new_policy->max_expected; | |
348 | policy->timeout = new_policy->timeout; | |
349 | } | |
350 | ||
14463859 GS |
351 | err: |
352 | kfree(new_policy); | |
353 | return ret; | |
2c422257 PNA |
354 | } |
355 | ||
356 | static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, | |
357 | const struct nlattr *attr) | |
358 | { | |
359 | struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; | |
360 | unsigned int class_max; | |
361 | int err; | |
362 | ||
8cb08174 JB |
363 | err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr, |
364 | nfnl_cthelper_expect_policy_set, | |
365 | 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 | ||
ae0be8de | 465 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE); |
12f7a505 PNA |
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 | ||
ae0be8de | 490 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY); |
12f7a505 PNA |
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++) { |
ae0be8de | 499 | nest_parms2 = nla_nest_start(skb, (NFCTH_POLICY_SET + i)); |
12f7a505 PNA |
500 | if (nest_parms2 == NULL) |
501 | goto nla_put_failure; | |
502 | ||
503 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
504 | helper->expect_policy[i].name)) | |
505 | goto nla_put_failure; | |
506 | ||
507 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
508 | htonl(helper->expect_policy[i].max_expected))) | |
509 | goto nla_put_failure; | |
510 | ||
511 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
512 | htonl(helper->expect_policy[i].timeout))) | |
513 | goto nla_put_failure; | |
514 | ||
515 | nla_nest_end(skb, nest_parms2); | |
516 | } | |
517 | nla_nest_end(skb, nest_parms1); | |
518 | return 0; | |
519 | ||
520 | nla_put_failure: | |
521 | return -1; | |
522 | } | |
523 | ||
524 | static int | |
15e47304 | 525 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
526 | int event, struct nf_conntrack_helper *helper) |
527 | { | |
528 | struct nlmsghdr *nlh; | |
529 | struct nfgenmsg *nfmsg; | |
15e47304 | 530 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
531 | int status; |
532 | ||
dedb67c4 | 533 | event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, event); |
15e47304 | 534 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
535 | if (nlh == NULL) |
536 | goto nlmsg_failure; | |
537 | ||
538 | nfmsg = nlmsg_data(nlh); | |
539 | nfmsg->nfgen_family = AF_UNSPEC; | |
540 | nfmsg->version = NFNETLINK_V0; | |
541 | nfmsg->res_id = 0; | |
542 | ||
543 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
544 | goto nla_put_failure; | |
545 | ||
546 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
547 | goto nla_put_failure; | |
548 | ||
549 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
550 | goto nla_put_failure; | |
551 | ||
552 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
553 | goto nla_put_failure; | |
554 | ||
555 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
556 | goto nla_put_failure; | |
557 | ||
558 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
559 | status = NFCT_HELPER_STATUS_ENABLED; | |
560 | else | |
561 | status = NFCT_HELPER_STATUS_DISABLED; | |
562 | ||
563 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
564 | goto nla_put_failure; | |
565 | ||
566 | nlmsg_end(skb, nlh); | |
567 | return skb->len; | |
568 | ||
569 | nlmsg_failure: | |
570 | nla_put_failure: | |
571 | nlmsg_cancel(skb, nlh); | |
572 | return -1; | |
573 | } | |
574 | ||
575 | static int | |
576 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
577 | { | |
578 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
579 | |
580 | rcu_read_lock(); | |
581 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
582 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
583 | restart: | |
b67bfe0d | 584 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
585 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
586 | ||
587 | /* skip non-userspace conntrack helpers. */ | |
588 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
589 | continue; | |
590 | ||
591 | if (cb->args[1]) { | |
592 | if (cur != last) | |
593 | continue; | |
594 | cb->args[1] = 0; | |
595 | } | |
596 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 597 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
598 | cb->nlh->nlmsg_seq, |
599 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
600 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
601 | cb->args[1] = (unsigned long)cur; | |
602 | goto out; | |
603 | } | |
604 | } | |
605 | } | |
606 | if (cb->args[1]) { | |
607 | cb->args[1] = 0; | |
608 | goto restart; | |
609 | } | |
610 | out: | |
611 | rcu_read_unlock(); | |
612 | return skb->len; | |
613 | } | |
614 | ||
7b8002a1 PNA |
615 | static int nfnl_cthelper_get(struct net *net, struct sock *nfnl, |
616 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
617 | const struct nlattr * const tb[], |
618 | struct netlink_ext_ack *extack) | |
12f7a505 | 619 | { |
83d90219 | 620 | int ret = -ENOENT; |
12f7a505 | 621 | struct nf_conntrack_helper *cur; |
12f7a505 PNA |
622 | struct sk_buff *skb2; |
623 | char *helper_name = NULL; | |
624 | struct nf_conntrack_tuple tuple; | |
83d90219 | 625 | struct nfnl_cthelper *nlcth; |
12f7a505 PNA |
626 | bool tuple_set = false; |
627 | ||
4b380c42 KC |
628 | if (!capable(CAP_NET_ADMIN)) |
629 | return -EPERM; | |
630 | ||
12f7a505 PNA |
631 | if (nlh->nlmsg_flags & NLM_F_DUMP) { |
632 | struct netlink_dump_control c = { | |
633 | .dump = nfnl_cthelper_dump_table, | |
634 | }; | |
635 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
636 | } | |
637 | ||
638 | if (tb[NFCTH_NAME]) | |
639 | helper_name = nla_data(tb[NFCTH_NAME]); | |
640 | ||
641 | if (tb[NFCTH_TUPLE]) { | |
642 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
643 | if (ret < 0) | |
644 | return ret; | |
645 | ||
646 | tuple_set = true; | |
647 | } | |
648 | ||
83d90219 LZ |
649 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
650 | cur = &nlcth->helper; | |
651 | if (helper_name && | |
652 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
653 | continue; | |
12f7a505 | 654 | |
83d90219 LZ |
655 | if (tuple_set && |
656 | (tuple.src.l3num != cur->tuple.src.l3num || | |
657 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
658 | continue; | |
12f7a505 | 659 | |
83d90219 LZ |
660 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
661 | if (skb2 == NULL) { | |
662 | ret = -ENOMEM; | |
663 | break; | |
664 | } | |
12f7a505 | 665 | |
83d90219 LZ |
666 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
667 | nlh->nlmsg_seq, | |
668 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
669 | NFNL_MSG_CTHELPER_NEW, cur); | |
670 | if (ret <= 0) { | |
671 | kfree_skb(skb2); | |
672 | break; | |
673 | } | |
12f7a505 | 674 | |
83d90219 LZ |
675 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
676 | MSG_DONTWAIT); | |
677 | if (ret > 0) | |
678 | ret = 0; | |
12f7a505 | 679 | |
83d90219 LZ |
680 | /* this avoids a loop in nfnetlink. */ |
681 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
12f7a505 PNA |
682 | } |
683 | return ret; | |
684 | } | |
685 | ||
7b8002a1 PNA |
686 | static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, |
687 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
688 | const struct nlattr * const tb[], |
689 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
690 | { |
691 | char *helper_name = NULL; | |
692 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
693 | struct nf_conntrack_tuple tuple; |
694 | bool tuple_set = false, found = false; | |
83d90219 LZ |
695 | struct nfnl_cthelper *nlcth, *n; |
696 | int j = 0, ret; | |
12f7a505 | 697 | |
4b380c42 KC |
698 | if (!capable(CAP_NET_ADMIN)) |
699 | return -EPERM; | |
700 | ||
12f7a505 PNA |
701 | if (tb[NFCTH_NAME]) |
702 | helper_name = nla_data(tb[NFCTH_NAME]); | |
703 | ||
704 | if (tb[NFCTH_TUPLE]) { | |
705 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
706 | if (ret < 0) | |
707 | return ret; | |
708 | ||
709 | tuple_set = true; | |
710 | } | |
711 | ||
9338d7b4 | 712 | ret = -ENOENT; |
83d90219 LZ |
713 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
714 | cur = &nlcth->helper; | |
715 | j++; | |
12f7a505 | 716 | |
83d90219 LZ |
717 | if (helper_name && |
718 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
719 | continue; | |
12f7a505 | 720 | |
83d90219 LZ |
721 | if (tuple_set && |
722 | (tuple.src.l3num != cur->tuple.src.l3num || | |
723 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
724 | continue; | |
12f7a505 | 725 | |
9338d7b4 LZ |
726 | if (refcount_dec_if_one(&cur->refcnt)) { |
727 | found = true; | |
728 | nf_conntrack_helper_unregister(cur); | |
729 | kfree(cur->expect_policy); | |
83d90219 | 730 | |
9338d7b4 LZ |
731 | list_del(&nlcth->list); |
732 | kfree(nlcth); | |
733 | } else { | |
734 | ret = -EBUSY; | |
735 | } | |
12f7a505 | 736 | } |
83d90219 | 737 | |
12f7a505 | 738 | /* Make sure we return success if we flush and there is no helpers */ |
9338d7b4 | 739 | return (found || j == 0) ? 0 : ret; |
12f7a505 PNA |
740 | } |
741 | ||
742 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
743 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
744 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
745 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
c049b345 JK |
746 | [NFCTH_PRIV_DATA_LEN] = { .type = NLA_U32, }, |
747 | [NFCTH_STATUS] = { .type = NLA_U32, }, | |
12f7a505 PNA |
748 | }; |
749 | ||
750 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
751 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
752 | .attr_count = NFCTH_MAX, | |
753 | .policy = nfnl_cthelper_policy }, | |
754 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
755 | .attr_count = NFCTH_MAX, | |
756 | .policy = nfnl_cthelper_policy }, | |
757 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
758 | .attr_count = NFCTH_MAX, | |
759 | .policy = nfnl_cthelper_policy }, | |
760 | }; | |
761 | ||
762 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
763 | .name = "cthelper", | |
764 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
765 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
766 | .cb = nfnl_cthelper_cb, | |
767 | }; | |
768 | ||
769 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
770 | ||
771 | static int __init nfnl_cthelper_init(void) | |
772 | { | |
773 | int ret; | |
774 | ||
775 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
776 | if (ret < 0) { | |
777 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
778 | goto err_out; | |
779 | } | |
780 | return 0; | |
781 | err_out: | |
782 | return ret; | |
783 | } | |
784 | ||
785 | static void __exit nfnl_cthelper_exit(void) | |
786 | { | |
787 | struct nf_conntrack_helper *cur; | |
83d90219 | 788 | struct nfnl_cthelper *nlcth, *n; |
12f7a505 PNA |
789 | |
790 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
791 | ||
83d90219 LZ |
792 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
793 | cur = &nlcth->helper; | |
12f7a505 | 794 | |
83d90219 LZ |
795 | nf_conntrack_helper_unregister(cur); |
796 | kfree(cur->expect_policy); | |
797 | kfree(nlcth); | |
12f7a505 PNA |
798 | } |
799 | } | |
800 | ||
801 | module_init(nfnl_cthelper_init); | |
802 | module_exit(nfnl_cthelper_exit); |