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 | ||
35 | static int | |
36 | nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff, | |
37 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) | |
38 | { | |
39 | const struct nf_conn_help *help; | |
40 | struct nf_conntrack_helper *helper; | |
41 | ||
42 | help = nfct_help(ct); | |
43 | if (help == NULL) | |
44 | return NF_DROP; | |
45 | ||
46 | /* rcu_read_lock()ed by nf_hook_slow */ | |
47 | helper = rcu_dereference(help->helper); | |
48 | if (helper == NULL) | |
49 | return NF_DROP; | |
50 | ||
51 | /* This is an user-space helper not yet configured, skip. */ | |
52 | if ((helper->flags & | |
53 | (NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) == | |
54 | NF_CT_HELPER_F_USERSPACE) | |
55 | return NF_ACCEPT; | |
56 | ||
57 | /* If the user-space helper is not available, don't block traffic. */ | |
58 | return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS; | |
59 | } | |
60 | ||
61 | static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = { | |
62 | [NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, }, | |
63 | [NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, }, | |
64 | }; | |
65 | ||
66 | static int | |
67 | nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, | |
68 | const struct nlattr *attr) | |
69 | { | |
70 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; | |
71 | ||
72 | nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol); | |
73 | ||
74 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) | |
75 | return -EINVAL; | |
76 | ||
fe31d1a8 | 77 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
12f7a505 PNA |
78 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int | |
84 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) | |
85 | { | |
86 | const struct nf_conn_help *help = nfct_help(ct); | |
87 | ||
7be54ca4 PNA |
88 | if (attr == NULL) |
89 | return -EINVAL; | |
90 | ||
12f7a505 PNA |
91 | if (help->helper->data_len == 0) |
92 | return -EINVAL; | |
93 | ||
94 | memcpy(&help->data, nla_data(attr), help->helper->data_len); | |
95 | return 0; | |
96 | } | |
97 | ||
98 | static int | |
99 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) | |
100 | { | |
101 | const struct nf_conn_help *help = nfct_help(ct); | |
102 | ||
103 | if (help->helper->data_len && | |
104 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) | |
105 | goto nla_put_failure; | |
106 | ||
107 | return 0; | |
108 | ||
109 | nla_put_failure: | |
110 | return -ENOSPC; | |
111 | } | |
112 | ||
113 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { | |
114 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, | |
115 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
116 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, | |
117 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, | |
118 | }; | |
119 | ||
120 | static int | |
121 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, | |
122 | const struct nlattr *attr) | |
123 | { | |
124 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; | |
125 | ||
126 | nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol); | |
127 | ||
128 | if (!tb[NFCTH_POLICY_NAME] || | |
129 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
130 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
131 | return -EINVAL; | |
132 | ||
133 | strncpy(expect_policy->name, | |
134 | nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); | |
135 | expect_policy->max_expected = | |
136 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
137 | expect_policy->timeout = | |
138 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
139 | ||
140 | return 0; | |
141 | } | |
142 | ||
143 | static const struct nla_policy | |
144 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
145 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
146 | }; | |
147 | ||
148 | static int | |
149 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
150 | const struct nlattr *attr) | |
151 | { | |
152 | int i, ret; | |
153 | struct nf_conntrack_expect_policy *expect_policy; | |
154 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
155 | ||
156 | nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, | |
157 | nfnl_cthelper_expect_policy_set); | |
158 | ||
159 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
160 | return -EINVAL; | |
161 | ||
162 | helper->expect_class_max = | |
163 | ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
164 | ||
165 | if (helper->expect_class_max != 0 && | |
166 | helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES) | |
167 | return -EOVERFLOW; | |
168 | ||
169 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * | |
170 | helper->expect_class_max, GFP_KERNEL); | |
171 | if (expect_policy == NULL) | |
172 | return -ENOMEM; | |
173 | ||
174 | for (i=0; i<helper->expect_class_max; i++) { | |
175 | if (!tb[NFCTH_POLICY_SET+i]) | |
176 | goto err; | |
177 | ||
178 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
179 | tb[NFCTH_POLICY_SET+i]); | |
180 | if (ret < 0) | |
181 | goto err; | |
182 | } | |
183 | helper->expect_policy = expect_policy; | |
184 | return 0; | |
185 | err: | |
186 | kfree(expect_policy); | |
187 | return -EINVAL; | |
188 | } | |
189 | ||
190 | static int | |
191 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
192 | struct nf_conntrack_tuple *tuple) | |
193 | { | |
194 | struct nf_conntrack_helper *helper; | |
195 | int ret; | |
196 | ||
197 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
198 | return -EINVAL; | |
199 | ||
200 | helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL); | |
201 | if (helper == NULL) | |
202 | return -ENOMEM; | |
203 | ||
204 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
205 | if (ret < 0) | |
206 | goto err; | |
207 | ||
208 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); | |
209 | helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); | |
210 | helper->flags |= NF_CT_HELPER_F_USERSPACE; | |
211 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
212 | ||
213 | helper->me = THIS_MODULE; | |
214 | helper->help = nfnl_userspace_cthelper; | |
215 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
216 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
217 | ||
218 | /* Default to queue number zero, this can be updated at any time. */ | |
219 | if (tb[NFCTH_QUEUE_NUM]) | |
220 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
221 | ||
222 | if (tb[NFCTH_STATUS]) { | |
223 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
224 | ||
225 | switch(status) { | |
226 | case NFCT_HELPER_STATUS_ENABLED: | |
227 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
228 | break; | |
229 | case NFCT_HELPER_STATUS_DISABLED: | |
230 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
231 | break; | |
232 | } | |
233 | } | |
234 | ||
235 | ret = nf_conntrack_helper_register(helper); | |
236 | if (ret < 0) | |
237 | goto err; | |
238 | ||
239 | return 0; | |
240 | err: | |
241 | kfree(helper); | |
242 | return ret; | |
243 | } | |
244 | ||
245 | static int | |
246 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
247 | struct nf_conntrack_helper *helper) | |
248 | { | |
249 | int ret; | |
250 | ||
251 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
252 | return -EBUSY; | |
253 | ||
254 | if (tb[NFCTH_POLICY]) { | |
255 | ret = nfnl_cthelper_parse_expect_policy(helper, | |
256 | tb[NFCTH_POLICY]); | |
257 | if (ret < 0) | |
258 | return ret; | |
259 | } | |
260 | if (tb[NFCTH_QUEUE_NUM]) | |
261 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
262 | ||
263 | if (tb[NFCTH_STATUS]) { | |
264 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
265 | ||
266 | switch(status) { | |
267 | case NFCT_HELPER_STATUS_ENABLED: | |
268 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
269 | break; | |
270 | case NFCT_HELPER_STATUS_DISABLED: | |
271 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
272 | break; | |
273 | } | |
274 | } | |
275 | return 0; | |
276 | } | |
277 | ||
278 | static int | |
279 | nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb, | |
280 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
281 | { | |
282 | const char *helper_name; | |
283 | struct nf_conntrack_helper *cur, *helper = NULL; | |
284 | struct nf_conntrack_tuple tuple; | |
285 | struct hlist_node *n; | |
286 | int ret = 0, i; | |
287 | ||
288 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) | |
289 | return -EINVAL; | |
290 | ||
291 | helper_name = nla_data(tb[NFCTH_NAME]); | |
292 | ||
293 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
294 | if (ret < 0) | |
295 | return ret; | |
296 | ||
297 | rcu_read_lock(); | |
298 | for (i = 0; i < nf_ct_helper_hsize && !helper; i++) { | |
299 | hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) { | |
300 | ||
301 | /* skip non-userspace conntrack helpers. */ | |
302 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
303 | continue; | |
304 | ||
305 | if (strncmp(cur->name, helper_name, | |
306 | NF_CT_HELPER_NAME_LEN) != 0) | |
307 | continue; | |
308 | ||
309 | if ((tuple.src.l3num != cur->tuple.src.l3num || | |
310 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
311 | continue; | |
312 | ||
313 | if (nlh->nlmsg_flags & NLM_F_EXCL) { | |
314 | ret = -EEXIST; | |
315 | goto err; | |
316 | } | |
317 | helper = cur; | |
318 | break; | |
319 | } | |
320 | } | |
321 | rcu_read_unlock(); | |
322 | ||
323 | if (helper == NULL) | |
324 | ret = nfnl_cthelper_create(tb, &tuple); | |
325 | else | |
326 | ret = nfnl_cthelper_update(tb, helper); | |
327 | ||
328 | return ret; | |
329 | err: | |
330 | rcu_read_unlock(); | |
331 | return ret; | |
332 | } | |
333 | ||
334 | static int | |
335 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
336 | struct nf_conntrack_helper *helper) | |
337 | { | |
338 | struct nlattr *nest_parms; | |
339 | ||
340 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
341 | if (nest_parms == NULL) | |
342 | goto nla_put_failure; | |
343 | ||
344 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
345 | htons(helper->tuple.src.l3num))) | |
346 | goto nla_put_failure; | |
347 | ||
348 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
349 | goto nla_put_failure; | |
350 | ||
351 | nla_nest_end(skb, nest_parms); | |
352 | return 0; | |
353 | ||
354 | nla_put_failure: | |
355 | return -1; | |
356 | } | |
357 | ||
358 | static int | |
359 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
360 | struct nf_conntrack_helper *helper) | |
361 | { | |
362 | int i; | |
363 | struct nlattr *nest_parms1, *nest_parms2; | |
364 | ||
365 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
366 | if (nest_parms1 == NULL) | |
367 | goto nla_put_failure; | |
368 | ||
369 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
370 | htonl(helper->expect_class_max))) | |
371 | goto nla_put_failure; | |
372 | ||
373 | for (i=0; i<helper->expect_class_max; i++) { | |
374 | nest_parms2 = nla_nest_start(skb, | |
375 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
376 | if (nest_parms2 == NULL) | |
377 | goto nla_put_failure; | |
378 | ||
379 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
380 | helper->expect_policy[i].name)) | |
381 | goto nla_put_failure; | |
382 | ||
383 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
384 | htonl(helper->expect_policy[i].max_expected))) | |
385 | goto nla_put_failure; | |
386 | ||
387 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
388 | htonl(helper->expect_policy[i].timeout))) | |
389 | goto nla_put_failure; | |
390 | ||
391 | nla_nest_end(skb, nest_parms2); | |
392 | } | |
393 | nla_nest_end(skb, nest_parms1); | |
394 | return 0; | |
395 | ||
396 | nla_put_failure: | |
397 | return -1; | |
398 | } | |
399 | ||
400 | static int | |
15e47304 | 401 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
402 | int event, struct nf_conntrack_helper *helper) |
403 | { | |
404 | struct nlmsghdr *nlh; | |
405 | struct nfgenmsg *nfmsg; | |
15e47304 | 406 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
407 | int status; |
408 | ||
409 | event |= NFNL_SUBSYS_CTHELPER << 8; | |
15e47304 | 410 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
411 | if (nlh == NULL) |
412 | goto nlmsg_failure; | |
413 | ||
414 | nfmsg = nlmsg_data(nlh); | |
415 | nfmsg->nfgen_family = AF_UNSPEC; | |
416 | nfmsg->version = NFNETLINK_V0; | |
417 | nfmsg->res_id = 0; | |
418 | ||
419 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
420 | goto nla_put_failure; | |
421 | ||
422 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
423 | goto nla_put_failure; | |
424 | ||
425 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
426 | goto nla_put_failure; | |
427 | ||
428 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
429 | goto nla_put_failure; | |
430 | ||
431 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
432 | goto nla_put_failure; | |
433 | ||
434 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
435 | status = NFCT_HELPER_STATUS_ENABLED; | |
436 | else | |
437 | status = NFCT_HELPER_STATUS_DISABLED; | |
438 | ||
439 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
440 | goto nla_put_failure; | |
441 | ||
442 | nlmsg_end(skb, nlh); | |
443 | return skb->len; | |
444 | ||
445 | nlmsg_failure: | |
446 | nla_put_failure: | |
447 | nlmsg_cancel(skb, nlh); | |
448 | return -1; | |
449 | } | |
450 | ||
451 | static int | |
452 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
453 | { | |
454 | struct nf_conntrack_helper *cur, *last; | |
455 | struct hlist_node *n; | |
456 | ||
457 | rcu_read_lock(); | |
458 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
459 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
460 | restart: | |
461 | hlist_for_each_entry_rcu(cur, n, | |
462 | &nf_ct_helper_hash[cb->args[0]], hnode) { | |
463 | ||
464 | /* skip non-userspace conntrack helpers. */ | |
465 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
466 | continue; | |
467 | ||
468 | if (cb->args[1]) { | |
469 | if (cur != last) | |
470 | continue; | |
471 | cb->args[1] = 0; | |
472 | } | |
473 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 474 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
475 | cb->nlh->nlmsg_seq, |
476 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
477 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
478 | cb->args[1] = (unsigned long)cur; | |
479 | goto out; | |
480 | } | |
481 | } | |
482 | } | |
483 | if (cb->args[1]) { | |
484 | cb->args[1] = 0; | |
485 | goto restart; | |
486 | } | |
487 | out: | |
488 | rcu_read_unlock(); | |
489 | return skb->len; | |
490 | } | |
491 | ||
492 | static int | |
493 | nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb, | |
494 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
495 | { | |
496 | int ret = -ENOENT, i; | |
497 | struct nf_conntrack_helper *cur; | |
498 | struct hlist_node *n; | |
499 | struct sk_buff *skb2; | |
500 | char *helper_name = NULL; | |
501 | struct nf_conntrack_tuple tuple; | |
502 | bool tuple_set = false; | |
503 | ||
504 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | |
505 | struct netlink_dump_control c = { | |
506 | .dump = nfnl_cthelper_dump_table, | |
507 | }; | |
508 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
509 | } | |
510 | ||
511 | if (tb[NFCTH_NAME]) | |
512 | helper_name = nla_data(tb[NFCTH_NAME]); | |
513 | ||
514 | if (tb[NFCTH_TUPLE]) { | |
515 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
516 | if (ret < 0) | |
517 | return ret; | |
518 | ||
519 | tuple_set = true; | |
520 | } | |
521 | ||
522 | for (i = 0; i < nf_ct_helper_hsize; i++) { | |
523 | hlist_for_each_entry_rcu(cur, n, &nf_ct_helper_hash[i], hnode) { | |
524 | ||
525 | /* skip non-userspace conntrack helpers. */ | |
526 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
527 | continue; | |
528 | ||
529 | if (helper_name && strncmp(cur->name, helper_name, | |
530 | NF_CT_HELPER_NAME_LEN) != 0) { | |
531 | continue; | |
532 | } | |
533 | if (tuple_set && | |
534 | (tuple.src.l3num != cur->tuple.src.l3num || | |
535 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
536 | continue; | |
537 | ||
538 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
539 | if (skb2 == NULL) { | |
540 | ret = -ENOMEM; | |
541 | break; | |
542 | } | |
543 | ||
15e47304 | 544 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
12f7a505 PNA |
545 | nlh->nlmsg_seq, |
546 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
547 | NFNL_MSG_CTHELPER_NEW, cur); | |
548 | if (ret <= 0) { | |
549 | kfree_skb(skb2); | |
550 | break; | |
551 | } | |
552 | ||
15e47304 | 553 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
12f7a505 PNA |
554 | MSG_DONTWAIT); |
555 | if (ret > 0) | |
556 | ret = 0; | |
557 | ||
558 | /* this avoids a loop in nfnetlink. */ | |
559 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
560 | } | |
561 | } | |
562 | return ret; | |
563 | } | |
564 | ||
565 | static int | |
566 | nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb, | |
567 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
568 | { | |
569 | char *helper_name = NULL; | |
570 | struct nf_conntrack_helper *cur; | |
571 | struct hlist_node *n, *tmp; | |
572 | struct nf_conntrack_tuple tuple; | |
573 | bool tuple_set = false, found = false; | |
574 | int i, j = 0, ret; | |
575 | ||
576 | if (tb[NFCTH_NAME]) | |
577 | helper_name = nla_data(tb[NFCTH_NAME]); | |
578 | ||
579 | if (tb[NFCTH_TUPLE]) { | |
580 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
581 | if (ret < 0) | |
582 | return ret; | |
583 | ||
584 | tuple_set = true; | |
585 | } | |
586 | ||
587 | for (i = 0; i < nf_ct_helper_hsize; i++) { | |
588 | hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i], | |
589 | hnode) { | |
590 | /* skip non-userspace conntrack helpers. */ | |
591 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
592 | continue; | |
593 | ||
594 | j++; | |
595 | ||
596 | if (helper_name && strncmp(cur->name, helper_name, | |
597 | NF_CT_HELPER_NAME_LEN) != 0) { | |
598 | continue; | |
599 | } | |
600 | if (tuple_set && | |
601 | (tuple.src.l3num != cur->tuple.src.l3num || | |
602 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
603 | continue; | |
604 | ||
605 | found = true; | |
606 | nf_conntrack_helper_unregister(cur); | |
607 | } | |
608 | } | |
609 | /* Make sure we return success if we flush and there is no helpers */ | |
610 | return (found || j == 0) ? 0 : -ENOENT; | |
611 | } | |
612 | ||
613 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
614 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
615 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
616 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
617 | }; | |
618 | ||
619 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
620 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
621 | .attr_count = NFCTH_MAX, | |
622 | .policy = nfnl_cthelper_policy }, | |
623 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
624 | .attr_count = NFCTH_MAX, | |
625 | .policy = nfnl_cthelper_policy }, | |
626 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
627 | .attr_count = NFCTH_MAX, | |
628 | .policy = nfnl_cthelper_policy }, | |
629 | }; | |
630 | ||
631 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
632 | .name = "cthelper", | |
633 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
634 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
635 | .cb = nfnl_cthelper_cb, | |
636 | }; | |
637 | ||
638 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
639 | ||
640 | static int __init nfnl_cthelper_init(void) | |
641 | { | |
642 | int ret; | |
643 | ||
644 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
645 | if (ret < 0) { | |
646 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
647 | goto err_out; | |
648 | } | |
649 | return 0; | |
650 | err_out: | |
651 | return ret; | |
652 | } | |
653 | ||
654 | static void __exit nfnl_cthelper_exit(void) | |
655 | { | |
656 | struct nf_conntrack_helper *cur; | |
657 | struct hlist_node *n, *tmp; | |
658 | int i; | |
659 | ||
660 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
661 | ||
662 | for (i=0; i<nf_ct_helper_hsize; i++) { | |
663 | hlist_for_each_entry_safe(cur, n, tmp, &nf_ct_helper_hash[i], | |
664 | hnode) { | |
665 | /* skip non-userspace conntrack helpers. */ | |
666 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
667 | continue; | |
668 | ||
669 | nf_conntrack_helper_unregister(cur); | |
670 | } | |
671 | } | |
672 | } | |
673 | ||
674 | module_init(nfnl_cthelper_init); | |
675 | module_exit(nfnl_cthelper_exit); |