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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 | ||
157ffffe | 108 | nla_memcpy(help->data, nla_data(attr), sizeof(help->data)); |
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])); | |
92f73221 GF |
155 | if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
156 | return -EINVAL; | |
157 | ||
12f7a505 PNA |
158 | expect_policy->timeout = |
159 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | static const struct nla_policy | |
165 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
166 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
167 | }; | |
168 | ||
169 | static int | |
170 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
171 | const struct nlattr *attr) | |
172 | { | |
173 | int i, ret; | |
174 | struct nf_conntrack_expect_policy *expect_policy; | |
175 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
ae5c6821 | 176 | unsigned int class_max; |
12f7a505 | 177 | |
130ffbc2 | 178 | ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, |
fceb6435 | 179 | nfnl_cthelper_expect_policy_set, NULL); |
130ffbc2 DB |
180 | if (ret < 0) |
181 | return ret; | |
12f7a505 PNA |
182 | |
183 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
184 | return -EINVAL; | |
185 | ||
ae5c6821 LZ |
186 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); |
187 | if (class_max == 0) | |
188 | return -EINVAL; | |
189 | if (class_max > NF_CT_MAX_EXPECT_CLASSES) | |
12f7a505 PNA |
190 | return -EOVERFLOW; |
191 | ||
192 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * | |
ae5c6821 | 193 | class_max, 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 PNA |
235 | |
236 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); | |
157ffffe FW |
237 | size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); |
238 | if (size > FIELD_SIZEOF(struct nf_conn_help, data)) { | |
239 | ret = -ENOMEM; | |
240 | goto err2; | |
241 | } | |
242 | ||
12f7a505 PNA |
243 | helper->flags |= NF_CT_HELPER_F_USERSPACE; |
244 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
245 | ||
246 | helper->me = THIS_MODULE; | |
247 | helper->help = nfnl_userspace_cthelper; | |
248 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
249 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
250 | ||
251 | /* Default to queue number zero, this can be updated at any time. */ | |
252 | if (tb[NFCTH_QUEUE_NUM]) | |
253 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
254 | ||
255 | if (tb[NFCTH_STATUS]) { | |
256 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
257 | ||
258 | switch(status) { | |
259 | case NFCT_HELPER_STATUS_ENABLED: | |
260 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
261 | break; | |
262 | case NFCT_HELPER_STATUS_DISABLED: | |
263 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
264 | break; | |
265 | } | |
266 | } | |
267 | ||
268 | ret = nf_conntrack_helper_register(helper); | |
269 | if (ret < 0) | |
f83bf8da | 270 | goto err2; |
12f7a505 | 271 | |
83d90219 | 272 | list_add_tail(&nfcth->list, &nfnl_cthelper_list); |
12f7a505 | 273 | return 0; |
f83bf8da JC |
274 | err2: |
275 | kfree(helper->expect_policy); | |
276 | err1: | |
83d90219 | 277 | kfree(nfcth); |
12f7a505 PNA |
278 | return ret; |
279 | } | |
280 | ||
2c422257 PNA |
281 | static int |
282 | nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, | |
283 | struct nf_conntrack_expect_policy *new_policy, | |
284 | const struct nlattr *attr) | |
285 | { | |
286 | struct nlattr *tb[NFCTH_POLICY_MAX + 1]; | |
287 | int err; | |
288 | ||
289 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, | |
fceb6435 | 290 | nfnl_cthelper_expect_pol, NULL); |
2c422257 PNA |
291 | if (err < 0) |
292 | return err; | |
293 | ||
294 | if (!tb[NFCTH_POLICY_NAME] || | |
295 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
296 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
297 | return -EINVAL; | |
298 | ||
299 | if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) | |
300 | return -EBUSY; | |
301 | ||
302 | new_policy->max_expected = | |
303 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
92f73221 GF |
304 | if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT) |
305 | return -EINVAL; | |
306 | ||
2c422257 PNA |
307 | new_policy->timeout = |
308 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], | |
314 | struct nf_conntrack_helper *helper) | |
315 | { | |
316 | struct nf_conntrack_expect_policy new_policy[helper->expect_class_max + 1]; | |
317 | struct nf_conntrack_expect_policy *policy; | |
318 | int i, err; | |
319 | ||
320 | /* Check first that all policy attributes are well-formed, so we don't | |
321 | * leave things in inconsistent state on errors. | |
322 | */ | |
323 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
324 | ||
325 | if (!tb[NFCTH_POLICY_SET + i]) | |
326 | return -EINVAL; | |
327 | ||
328 | err = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], | |
329 | &new_policy[i], | |
330 | tb[NFCTH_POLICY_SET + i]); | |
331 | if (err < 0) | |
332 | return err; | |
333 | } | |
334 | /* Now we can safely update them. */ | |
335 | for (i = 0; i < helper->expect_class_max + 1; i++) { | |
336 | policy = (struct nf_conntrack_expect_policy *) | |
337 | &helper->expect_policy[i]; | |
338 | policy->max_expected = new_policy->max_expected; | |
339 | policy->timeout = new_policy->timeout; | |
340 | } | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, | |
346 | const struct nlattr *attr) | |
347 | { | |
348 | struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; | |
349 | unsigned int class_max; | |
350 | int err; | |
351 | ||
352 | err = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, | |
fceb6435 | 353 | nfnl_cthelper_expect_policy_set, NULL); |
2c422257 PNA |
354 | if (err < 0) |
355 | return err; | |
356 | ||
357 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
358 | return -EINVAL; | |
359 | ||
360 | class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
361 | if (helper->expect_class_max + 1 != class_max) | |
362 | return -EBUSY; | |
363 | ||
364 | return nfnl_cthelper_update_policy_all(tb, helper); | |
365 | } | |
366 | ||
12f7a505 PNA |
367 | static int |
368 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
369 | struct nf_conntrack_helper *helper) | |
370 | { | |
371 | int ret; | |
372 | ||
373 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
374 | return -EBUSY; | |
375 | ||
376 | if (tb[NFCTH_POLICY]) { | |
2c422257 | 377 | ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]); |
12f7a505 PNA |
378 | if (ret < 0) |
379 | return ret; | |
380 | } | |
381 | if (tb[NFCTH_QUEUE_NUM]) | |
382 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
383 | ||
384 | if (tb[NFCTH_STATUS]) { | |
385 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
386 | ||
387 | switch(status) { | |
388 | case NFCT_HELPER_STATUS_ENABLED: | |
389 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
390 | break; | |
391 | case NFCT_HELPER_STATUS_DISABLED: | |
392 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
393 | break; | |
394 | } | |
395 | } | |
396 | return 0; | |
397 | } | |
398 | ||
7b8002a1 PNA |
399 | static int nfnl_cthelper_new(struct net *net, struct sock *nfnl, |
400 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
401 | const struct nlattr * const tb[], |
402 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
403 | { |
404 | const char *helper_name; | |
405 | struct nf_conntrack_helper *cur, *helper = NULL; | |
406 | struct nf_conntrack_tuple tuple; | |
83d90219 LZ |
407 | struct nfnl_cthelper *nlcth; |
408 | int ret = 0; | |
12f7a505 PNA |
409 | |
410 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) | |
411 | return -EINVAL; | |
412 | ||
413 | helper_name = nla_data(tb[NFCTH_NAME]); | |
414 | ||
415 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
416 | if (ret < 0) | |
417 | return ret; | |
418 | ||
83d90219 LZ |
419 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
420 | cur = &nlcth->helper; | |
12f7a505 | 421 | |
83d90219 LZ |
422 | if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) |
423 | continue; | |
12f7a505 | 424 | |
83d90219 LZ |
425 | if ((tuple.src.l3num != cur->tuple.src.l3num || |
426 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
427 | continue; | |
12f7a505 | 428 | |
83d90219 LZ |
429 | if (nlh->nlmsg_flags & NLM_F_EXCL) |
430 | return -EEXIST; | |
12f7a505 | 431 | |
83d90219 LZ |
432 | helper = cur; |
433 | break; | |
12f7a505 | 434 | } |
12f7a505 PNA |
435 | |
436 | if (helper == NULL) | |
437 | ret = nfnl_cthelper_create(tb, &tuple); | |
438 | else | |
439 | ret = nfnl_cthelper_update(tb, helper); | |
440 | ||
441 | return ret; | |
12f7a505 PNA |
442 | } |
443 | ||
444 | static int | |
445 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
446 | struct nf_conntrack_helper *helper) | |
447 | { | |
448 | struct nlattr *nest_parms; | |
449 | ||
450 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
451 | if (nest_parms == NULL) | |
452 | goto nla_put_failure; | |
453 | ||
454 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
455 | htons(helper->tuple.src.l3num))) | |
456 | goto nla_put_failure; | |
457 | ||
458 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
459 | goto nla_put_failure; | |
460 | ||
461 | nla_nest_end(skb, nest_parms); | |
462 | return 0; | |
463 | ||
464 | nla_put_failure: | |
465 | return -1; | |
466 | } | |
467 | ||
468 | static int | |
469 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
470 | struct nf_conntrack_helper *helper) | |
471 | { | |
472 | int i; | |
473 | struct nlattr *nest_parms1, *nest_parms2; | |
474 | ||
475 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
476 | if (nest_parms1 == NULL) | |
477 | goto nla_put_failure; | |
478 | ||
479 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
ae5c6821 | 480 | htonl(helper->expect_class_max + 1))) |
12f7a505 PNA |
481 | goto nla_put_failure; |
482 | ||
ae5c6821 | 483 | for (i = 0; i < helper->expect_class_max + 1; i++) { |
12f7a505 PNA |
484 | nest_parms2 = nla_nest_start(skb, |
485 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
486 | if (nest_parms2 == NULL) | |
487 | goto nla_put_failure; | |
488 | ||
489 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
490 | helper->expect_policy[i].name)) | |
491 | goto nla_put_failure; | |
492 | ||
493 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
494 | htonl(helper->expect_policy[i].max_expected))) | |
495 | goto nla_put_failure; | |
496 | ||
497 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
498 | htonl(helper->expect_policy[i].timeout))) | |
499 | goto nla_put_failure; | |
500 | ||
501 | nla_nest_end(skb, nest_parms2); | |
502 | } | |
503 | nla_nest_end(skb, nest_parms1); | |
504 | return 0; | |
505 | ||
506 | nla_put_failure: | |
507 | return -1; | |
508 | } | |
509 | ||
510 | static int | |
15e47304 | 511 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
512 | int event, struct nf_conntrack_helper *helper) |
513 | { | |
514 | struct nlmsghdr *nlh; | |
515 | struct nfgenmsg *nfmsg; | |
15e47304 | 516 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
517 | int status; |
518 | ||
dedb67c4 | 519 | event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, event); |
15e47304 | 520 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
521 | if (nlh == NULL) |
522 | goto nlmsg_failure; | |
523 | ||
524 | nfmsg = nlmsg_data(nlh); | |
525 | nfmsg->nfgen_family = AF_UNSPEC; | |
526 | nfmsg->version = NFNETLINK_V0; | |
527 | nfmsg->res_id = 0; | |
528 | ||
529 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
530 | goto nla_put_failure; | |
531 | ||
532 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
533 | goto nla_put_failure; | |
534 | ||
535 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
536 | goto nla_put_failure; | |
537 | ||
538 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
539 | goto nla_put_failure; | |
540 | ||
541 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
542 | goto nla_put_failure; | |
543 | ||
544 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
545 | status = NFCT_HELPER_STATUS_ENABLED; | |
546 | else | |
547 | status = NFCT_HELPER_STATUS_DISABLED; | |
548 | ||
549 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
550 | goto nla_put_failure; | |
551 | ||
552 | nlmsg_end(skb, nlh); | |
553 | return skb->len; | |
554 | ||
555 | nlmsg_failure: | |
556 | nla_put_failure: | |
557 | nlmsg_cancel(skb, nlh); | |
558 | return -1; | |
559 | } | |
560 | ||
561 | static int | |
562 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
563 | { | |
564 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
565 | |
566 | rcu_read_lock(); | |
567 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
568 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
569 | restart: | |
b67bfe0d | 570 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
571 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
572 | ||
573 | /* skip non-userspace conntrack helpers. */ | |
574 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
575 | continue; | |
576 | ||
577 | if (cb->args[1]) { | |
578 | if (cur != last) | |
579 | continue; | |
580 | cb->args[1] = 0; | |
581 | } | |
582 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 583 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
584 | cb->nlh->nlmsg_seq, |
585 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
586 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
587 | cb->args[1] = (unsigned long)cur; | |
588 | goto out; | |
589 | } | |
590 | } | |
591 | } | |
592 | if (cb->args[1]) { | |
593 | cb->args[1] = 0; | |
594 | goto restart; | |
595 | } | |
596 | out: | |
597 | rcu_read_unlock(); | |
598 | return skb->len; | |
599 | } | |
600 | ||
7b8002a1 PNA |
601 | static int nfnl_cthelper_get(struct net *net, struct sock *nfnl, |
602 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
603 | const struct nlattr * const tb[], |
604 | struct netlink_ext_ack *extack) | |
12f7a505 | 605 | { |
83d90219 | 606 | int ret = -ENOENT; |
12f7a505 | 607 | struct nf_conntrack_helper *cur; |
12f7a505 PNA |
608 | struct sk_buff *skb2; |
609 | char *helper_name = NULL; | |
610 | struct nf_conntrack_tuple tuple; | |
83d90219 | 611 | struct nfnl_cthelper *nlcth; |
12f7a505 PNA |
612 | bool tuple_set = false; |
613 | ||
614 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | |
615 | struct netlink_dump_control c = { | |
616 | .dump = nfnl_cthelper_dump_table, | |
617 | }; | |
618 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
619 | } | |
620 | ||
621 | if (tb[NFCTH_NAME]) | |
622 | helper_name = nla_data(tb[NFCTH_NAME]); | |
623 | ||
624 | if (tb[NFCTH_TUPLE]) { | |
625 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
626 | if (ret < 0) | |
627 | return ret; | |
628 | ||
629 | tuple_set = true; | |
630 | } | |
631 | ||
83d90219 LZ |
632 | list_for_each_entry(nlcth, &nfnl_cthelper_list, list) { |
633 | cur = &nlcth->helper; | |
634 | if (helper_name && | |
635 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
636 | continue; | |
12f7a505 | 637 | |
83d90219 LZ |
638 | if (tuple_set && |
639 | (tuple.src.l3num != cur->tuple.src.l3num || | |
640 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
641 | continue; | |
12f7a505 | 642 | |
83d90219 LZ |
643 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
644 | if (skb2 == NULL) { | |
645 | ret = -ENOMEM; | |
646 | break; | |
647 | } | |
12f7a505 | 648 | |
83d90219 LZ |
649 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
650 | nlh->nlmsg_seq, | |
651 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
652 | NFNL_MSG_CTHELPER_NEW, cur); | |
653 | if (ret <= 0) { | |
654 | kfree_skb(skb2); | |
655 | break; | |
656 | } | |
12f7a505 | 657 | |
83d90219 LZ |
658 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
659 | MSG_DONTWAIT); | |
660 | if (ret > 0) | |
661 | ret = 0; | |
12f7a505 | 662 | |
83d90219 LZ |
663 | /* this avoids a loop in nfnetlink. */ |
664 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
12f7a505 PNA |
665 | } |
666 | return ret; | |
667 | } | |
668 | ||
7b8002a1 PNA |
669 | static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, |
670 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
04ba724b PNA |
671 | const struct nlattr * const tb[], |
672 | struct netlink_ext_ack *extack) | |
12f7a505 PNA |
673 | { |
674 | char *helper_name = NULL; | |
675 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
676 | struct nf_conntrack_tuple tuple; |
677 | bool tuple_set = false, found = false; | |
83d90219 LZ |
678 | struct nfnl_cthelper *nlcth, *n; |
679 | int j = 0, ret; | |
12f7a505 PNA |
680 | |
681 | if (tb[NFCTH_NAME]) | |
682 | helper_name = nla_data(tb[NFCTH_NAME]); | |
683 | ||
684 | if (tb[NFCTH_TUPLE]) { | |
685 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
686 | if (ret < 0) | |
687 | return ret; | |
688 | ||
689 | tuple_set = true; | |
690 | } | |
691 | ||
9338d7b4 | 692 | ret = -ENOENT; |
83d90219 LZ |
693 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
694 | cur = &nlcth->helper; | |
695 | j++; | |
12f7a505 | 696 | |
83d90219 LZ |
697 | if (helper_name && |
698 | strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN)) | |
699 | continue; | |
12f7a505 | 700 | |
83d90219 LZ |
701 | if (tuple_set && |
702 | (tuple.src.l3num != cur->tuple.src.l3num || | |
703 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
704 | continue; | |
12f7a505 | 705 | |
9338d7b4 LZ |
706 | if (refcount_dec_if_one(&cur->refcnt)) { |
707 | found = true; | |
708 | nf_conntrack_helper_unregister(cur); | |
709 | kfree(cur->expect_policy); | |
83d90219 | 710 | |
9338d7b4 LZ |
711 | list_del(&nlcth->list); |
712 | kfree(nlcth); | |
713 | } else { | |
714 | ret = -EBUSY; | |
715 | } | |
12f7a505 | 716 | } |
83d90219 | 717 | |
12f7a505 | 718 | /* Make sure we return success if we flush and there is no helpers */ |
9338d7b4 | 719 | return (found || j == 0) ? 0 : ret; |
12f7a505 PNA |
720 | } |
721 | ||
722 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
723 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
724 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
725 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
726 | }; | |
727 | ||
728 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
729 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
730 | .attr_count = NFCTH_MAX, | |
731 | .policy = nfnl_cthelper_policy }, | |
732 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
733 | .attr_count = NFCTH_MAX, | |
734 | .policy = nfnl_cthelper_policy }, | |
735 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
736 | .attr_count = NFCTH_MAX, | |
737 | .policy = nfnl_cthelper_policy }, | |
738 | }; | |
739 | ||
740 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
741 | .name = "cthelper", | |
742 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
743 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
744 | .cb = nfnl_cthelper_cb, | |
745 | }; | |
746 | ||
747 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
748 | ||
749 | static int __init nfnl_cthelper_init(void) | |
750 | { | |
751 | int ret; | |
752 | ||
753 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
754 | if (ret < 0) { | |
755 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
756 | goto err_out; | |
757 | } | |
758 | return 0; | |
759 | err_out: | |
760 | return ret; | |
761 | } | |
762 | ||
763 | static void __exit nfnl_cthelper_exit(void) | |
764 | { | |
765 | struct nf_conntrack_helper *cur; | |
83d90219 | 766 | struct nfnl_cthelper *nlcth, *n; |
12f7a505 PNA |
767 | |
768 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
769 | ||
83d90219 LZ |
770 | list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { |
771 | cur = &nlcth->helper; | |
12f7a505 | 772 | |
83d90219 LZ |
773 | nf_conntrack_helper_unregister(cur); |
774 | kfree(cur->expect_policy); | |
775 | kfree(nlcth); | |
12f7a505 PNA |
776 | } |
777 | } | |
778 | ||
779 | module_init(nfnl_cthelper_init); | |
780 | module_exit(nfnl_cthelper_exit); |