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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 | ||
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 | { | |
130ffbc2 | 70 | int err; |
12f7a505 PNA |
71 | struct nlattr *tb[NFCTH_TUPLE_MAX+1]; |
72 | ||
130ffbc2 DB |
73 | err = nla_parse_nested(tb, NFCTH_TUPLE_MAX, attr, nfnl_cthelper_tuple_pol); |
74 | if (err < 0) | |
75 | return err; | |
12f7a505 PNA |
76 | |
77 | if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) | |
78 | return -EINVAL; | |
79 | ||
78146572 IW |
80 | /* Not all fields are initialized so first zero the tuple */ |
81 | memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); | |
82 | ||
fe31d1a8 | 83 | tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); |
12f7a505 PNA |
84 | tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static int | |
90 | nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) | |
91 | { | |
b18c5d15 | 92 | struct nf_conn_help *help = nfct_help(ct); |
12f7a505 | 93 | |
7be54ca4 PNA |
94 | if (attr == NULL) |
95 | return -EINVAL; | |
96 | ||
12f7a505 PNA |
97 | if (help->helper->data_len == 0) |
98 | return -EINVAL; | |
99 | ||
b18c5d15 | 100 | memcpy(help->data, nla_data(attr), help->helper->data_len); |
12f7a505 PNA |
101 | return 0; |
102 | } | |
103 | ||
104 | static int | |
105 | nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct) | |
106 | { | |
107 | const struct nf_conn_help *help = nfct_help(ct); | |
108 | ||
109 | if (help->helper->data_len && | |
110 | nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data)) | |
111 | goto nla_put_failure; | |
112 | ||
113 | return 0; | |
114 | ||
115 | nla_put_failure: | |
116 | return -ENOSPC; | |
117 | } | |
118 | ||
119 | static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = { | |
120 | [NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING, | |
121 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
122 | [NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, }, | |
123 | [NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, }, | |
124 | }; | |
125 | ||
126 | static int | |
127 | nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy, | |
128 | const struct nlattr *attr) | |
129 | { | |
130ffbc2 | 130 | int err; |
12f7a505 PNA |
131 | struct nlattr *tb[NFCTH_POLICY_MAX+1]; |
132 | ||
130ffbc2 DB |
133 | err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, nfnl_cthelper_expect_pol); |
134 | if (err < 0) | |
135 | return err; | |
12f7a505 PNA |
136 | |
137 | if (!tb[NFCTH_POLICY_NAME] || | |
138 | !tb[NFCTH_POLICY_EXPECT_MAX] || | |
139 | !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) | |
140 | return -EINVAL; | |
141 | ||
142 | strncpy(expect_policy->name, | |
143 | nla_data(tb[NFCTH_POLICY_NAME]), NF_CT_HELPER_NAME_LEN); | |
144 | expect_policy->max_expected = | |
145 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); | |
146 | expect_policy->timeout = | |
147 | ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static const struct nla_policy | |
153 | nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = { | |
154 | [NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, }, | |
155 | }; | |
156 | ||
157 | static int | |
158 | nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper, | |
159 | const struct nlattr *attr) | |
160 | { | |
161 | int i, ret; | |
162 | struct nf_conntrack_expect_policy *expect_policy; | |
163 | struct nlattr *tb[NFCTH_POLICY_SET_MAX+1]; | |
164 | ||
130ffbc2 DB |
165 | ret = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, |
166 | nfnl_cthelper_expect_policy_set); | |
167 | if (ret < 0) | |
168 | return ret; | |
12f7a505 PNA |
169 | |
170 | if (!tb[NFCTH_POLICY_SET_NUM]) | |
171 | return -EINVAL; | |
172 | ||
173 | helper->expect_class_max = | |
174 | ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); | |
175 | ||
176 | if (helper->expect_class_max != 0 && | |
177 | helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES) | |
178 | return -EOVERFLOW; | |
179 | ||
180 | expect_policy = kzalloc(sizeof(struct nf_conntrack_expect_policy) * | |
181 | helper->expect_class_max, GFP_KERNEL); | |
182 | if (expect_policy == NULL) | |
183 | return -ENOMEM; | |
184 | ||
185 | for (i=0; i<helper->expect_class_max; i++) { | |
186 | if (!tb[NFCTH_POLICY_SET+i]) | |
187 | goto err; | |
188 | ||
189 | ret = nfnl_cthelper_expect_policy(&expect_policy[i], | |
190 | tb[NFCTH_POLICY_SET+i]); | |
191 | if (ret < 0) | |
192 | goto err; | |
193 | } | |
194 | helper->expect_policy = expect_policy; | |
195 | return 0; | |
196 | err: | |
197 | kfree(expect_policy); | |
198 | return -EINVAL; | |
199 | } | |
200 | ||
201 | static int | |
202 | nfnl_cthelper_create(const struct nlattr * const tb[], | |
203 | struct nf_conntrack_tuple *tuple) | |
204 | { | |
205 | struct nf_conntrack_helper *helper; | |
206 | int ret; | |
207 | ||
208 | if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN]) | |
209 | return -EINVAL; | |
210 | ||
211 | helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL); | |
212 | if (helper == NULL) | |
213 | return -ENOMEM; | |
214 | ||
215 | ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]); | |
216 | if (ret < 0) | |
217 | goto err; | |
218 | ||
219 | strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN); | |
220 | helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); | |
221 | helper->flags |= NF_CT_HELPER_F_USERSPACE; | |
222 | memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple)); | |
223 | ||
224 | helper->me = THIS_MODULE; | |
225 | helper->help = nfnl_userspace_cthelper; | |
226 | helper->from_nlattr = nfnl_cthelper_from_nlattr; | |
227 | helper->to_nlattr = nfnl_cthelper_to_nlattr; | |
228 | ||
229 | /* Default to queue number zero, this can be updated at any time. */ | |
230 | if (tb[NFCTH_QUEUE_NUM]) | |
231 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
232 | ||
233 | if (tb[NFCTH_STATUS]) { | |
234 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
235 | ||
236 | switch(status) { | |
237 | case NFCT_HELPER_STATUS_ENABLED: | |
238 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
239 | break; | |
240 | case NFCT_HELPER_STATUS_DISABLED: | |
241 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
242 | break; | |
243 | } | |
244 | } | |
245 | ||
246 | ret = nf_conntrack_helper_register(helper); | |
247 | if (ret < 0) | |
248 | goto err; | |
249 | ||
250 | return 0; | |
251 | err: | |
252 | kfree(helper); | |
253 | return ret; | |
254 | } | |
255 | ||
256 | static int | |
257 | nfnl_cthelper_update(const struct nlattr * const tb[], | |
258 | struct nf_conntrack_helper *helper) | |
259 | { | |
260 | int ret; | |
261 | ||
262 | if (tb[NFCTH_PRIV_DATA_LEN]) | |
263 | return -EBUSY; | |
264 | ||
265 | if (tb[NFCTH_POLICY]) { | |
266 | ret = nfnl_cthelper_parse_expect_policy(helper, | |
267 | tb[NFCTH_POLICY]); | |
268 | if (ret < 0) | |
269 | return ret; | |
270 | } | |
271 | if (tb[NFCTH_QUEUE_NUM]) | |
272 | helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM])); | |
273 | ||
274 | if (tb[NFCTH_STATUS]) { | |
275 | int status = ntohl(nla_get_be32(tb[NFCTH_STATUS])); | |
276 | ||
277 | switch(status) { | |
278 | case NFCT_HELPER_STATUS_ENABLED: | |
279 | helper->flags |= NF_CT_HELPER_F_CONFIGURED; | |
280 | break; | |
281 | case NFCT_HELPER_STATUS_DISABLED: | |
282 | helper->flags &= ~NF_CT_HELPER_F_CONFIGURED; | |
283 | break; | |
284 | } | |
285 | } | |
286 | return 0; | |
287 | } | |
288 | ||
289 | static int | |
290 | nfnl_cthelper_new(struct sock *nfnl, struct sk_buff *skb, | |
291 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
292 | { | |
293 | const char *helper_name; | |
294 | struct nf_conntrack_helper *cur, *helper = NULL; | |
295 | struct nf_conntrack_tuple tuple; | |
12f7a505 PNA |
296 | int ret = 0, i; |
297 | ||
298 | if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE]) | |
299 | return -EINVAL; | |
300 | ||
301 | helper_name = nla_data(tb[NFCTH_NAME]); | |
302 | ||
303 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
304 | if (ret < 0) | |
305 | return ret; | |
306 | ||
307 | rcu_read_lock(); | |
308 | for (i = 0; i < nf_ct_helper_hsize && !helper; i++) { | |
b67bfe0d | 309 | hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) { |
12f7a505 PNA |
310 | |
311 | /* skip non-userspace conntrack helpers. */ | |
312 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
313 | continue; | |
314 | ||
315 | if (strncmp(cur->name, helper_name, | |
316 | NF_CT_HELPER_NAME_LEN) != 0) | |
317 | continue; | |
318 | ||
319 | if ((tuple.src.l3num != cur->tuple.src.l3num || | |
320 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
321 | continue; | |
322 | ||
323 | if (nlh->nlmsg_flags & NLM_F_EXCL) { | |
324 | ret = -EEXIST; | |
325 | goto err; | |
326 | } | |
327 | helper = cur; | |
328 | break; | |
329 | } | |
330 | } | |
331 | rcu_read_unlock(); | |
332 | ||
333 | if (helper == NULL) | |
334 | ret = nfnl_cthelper_create(tb, &tuple); | |
335 | else | |
336 | ret = nfnl_cthelper_update(tb, helper); | |
337 | ||
338 | return ret; | |
339 | err: | |
340 | rcu_read_unlock(); | |
341 | return ret; | |
342 | } | |
343 | ||
344 | static int | |
345 | nfnl_cthelper_dump_tuple(struct sk_buff *skb, | |
346 | struct nf_conntrack_helper *helper) | |
347 | { | |
348 | struct nlattr *nest_parms; | |
349 | ||
350 | nest_parms = nla_nest_start(skb, NFCTH_TUPLE | NLA_F_NESTED); | |
351 | if (nest_parms == NULL) | |
352 | goto nla_put_failure; | |
353 | ||
354 | if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM, | |
355 | htons(helper->tuple.src.l3num))) | |
356 | goto nla_put_failure; | |
357 | ||
358 | if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum)) | |
359 | goto nla_put_failure; | |
360 | ||
361 | nla_nest_end(skb, nest_parms); | |
362 | return 0; | |
363 | ||
364 | nla_put_failure: | |
365 | return -1; | |
366 | } | |
367 | ||
368 | static int | |
369 | nfnl_cthelper_dump_policy(struct sk_buff *skb, | |
370 | struct nf_conntrack_helper *helper) | |
371 | { | |
372 | int i; | |
373 | struct nlattr *nest_parms1, *nest_parms2; | |
374 | ||
375 | nest_parms1 = nla_nest_start(skb, NFCTH_POLICY | NLA_F_NESTED); | |
376 | if (nest_parms1 == NULL) | |
377 | goto nla_put_failure; | |
378 | ||
379 | if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM, | |
380 | htonl(helper->expect_class_max))) | |
381 | goto nla_put_failure; | |
382 | ||
383 | for (i=0; i<helper->expect_class_max; i++) { | |
384 | nest_parms2 = nla_nest_start(skb, | |
385 | (NFCTH_POLICY_SET+i) | NLA_F_NESTED); | |
386 | if (nest_parms2 == NULL) | |
387 | goto nla_put_failure; | |
388 | ||
389 | if (nla_put_string(skb, NFCTH_POLICY_NAME, | |
390 | helper->expect_policy[i].name)) | |
391 | goto nla_put_failure; | |
392 | ||
393 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX, | |
394 | htonl(helper->expect_policy[i].max_expected))) | |
395 | goto nla_put_failure; | |
396 | ||
397 | if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT, | |
398 | htonl(helper->expect_policy[i].timeout))) | |
399 | goto nla_put_failure; | |
400 | ||
401 | nla_nest_end(skb, nest_parms2); | |
402 | } | |
403 | nla_nest_end(skb, nest_parms1); | |
404 | return 0; | |
405 | ||
406 | nla_put_failure: | |
407 | return -1; | |
408 | } | |
409 | ||
410 | static int | |
15e47304 | 411 | nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
12f7a505 PNA |
412 | int event, struct nf_conntrack_helper *helper) |
413 | { | |
414 | struct nlmsghdr *nlh; | |
415 | struct nfgenmsg *nfmsg; | |
15e47304 | 416 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
12f7a505 PNA |
417 | int status; |
418 | ||
419 | event |= NFNL_SUBSYS_CTHELPER << 8; | |
15e47304 | 420 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
12f7a505 PNA |
421 | if (nlh == NULL) |
422 | goto nlmsg_failure; | |
423 | ||
424 | nfmsg = nlmsg_data(nlh); | |
425 | nfmsg->nfgen_family = AF_UNSPEC; | |
426 | nfmsg->version = NFNETLINK_V0; | |
427 | nfmsg->res_id = 0; | |
428 | ||
429 | if (nla_put_string(skb, NFCTH_NAME, helper->name)) | |
430 | goto nla_put_failure; | |
431 | ||
432 | if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num))) | |
433 | goto nla_put_failure; | |
434 | ||
435 | if (nfnl_cthelper_dump_tuple(skb, helper) < 0) | |
436 | goto nla_put_failure; | |
437 | ||
438 | if (nfnl_cthelper_dump_policy(skb, helper) < 0) | |
439 | goto nla_put_failure; | |
440 | ||
441 | if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len))) | |
442 | goto nla_put_failure; | |
443 | ||
444 | if (helper->flags & NF_CT_HELPER_F_CONFIGURED) | |
445 | status = NFCT_HELPER_STATUS_ENABLED; | |
446 | else | |
447 | status = NFCT_HELPER_STATUS_DISABLED; | |
448 | ||
449 | if (nla_put_be32(skb, NFCTH_STATUS, htonl(status))) | |
450 | goto nla_put_failure; | |
451 | ||
452 | nlmsg_end(skb, nlh); | |
453 | return skb->len; | |
454 | ||
455 | nlmsg_failure: | |
456 | nla_put_failure: | |
457 | nlmsg_cancel(skb, nlh); | |
458 | return -1; | |
459 | } | |
460 | ||
461 | static int | |
462 | nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb) | |
463 | { | |
464 | struct nf_conntrack_helper *cur, *last; | |
12f7a505 PNA |
465 | |
466 | rcu_read_lock(); | |
467 | last = (struct nf_conntrack_helper *)cb->args[1]; | |
468 | for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) { | |
469 | restart: | |
b67bfe0d | 470 | hlist_for_each_entry_rcu(cur, |
12f7a505 PNA |
471 | &nf_ct_helper_hash[cb->args[0]], hnode) { |
472 | ||
473 | /* skip non-userspace conntrack helpers. */ | |
474 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
475 | continue; | |
476 | ||
477 | if (cb->args[1]) { | |
478 | if (cur != last) | |
479 | continue; | |
480 | cb->args[1] = 0; | |
481 | } | |
482 | if (nfnl_cthelper_fill_info(skb, | |
15e47304 | 483 | NETLINK_CB(cb->skb).portid, |
12f7a505 PNA |
484 | cb->nlh->nlmsg_seq, |
485 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
486 | NFNL_MSG_CTHELPER_NEW, cur) < 0) { | |
487 | cb->args[1] = (unsigned long)cur; | |
488 | goto out; | |
489 | } | |
490 | } | |
491 | } | |
492 | if (cb->args[1]) { | |
493 | cb->args[1] = 0; | |
494 | goto restart; | |
495 | } | |
496 | out: | |
497 | rcu_read_unlock(); | |
498 | return skb->len; | |
499 | } | |
500 | ||
501 | static int | |
502 | nfnl_cthelper_get(struct sock *nfnl, struct sk_buff *skb, | |
503 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
504 | { | |
505 | int ret = -ENOENT, i; | |
506 | struct nf_conntrack_helper *cur; | |
12f7a505 PNA |
507 | struct sk_buff *skb2; |
508 | char *helper_name = NULL; | |
509 | struct nf_conntrack_tuple tuple; | |
510 | bool tuple_set = false; | |
511 | ||
512 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | |
513 | struct netlink_dump_control c = { | |
514 | .dump = nfnl_cthelper_dump_table, | |
515 | }; | |
516 | return netlink_dump_start(nfnl, skb, nlh, &c); | |
517 | } | |
518 | ||
519 | if (tb[NFCTH_NAME]) | |
520 | helper_name = nla_data(tb[NFCTH_NAME]); | |
521 | ||
522 | if (tb[NFCTH_TUPLE]) { | |
523 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
524 | if (ret < 0) | |
525 | return ret; | |
526 | ||
527 | tuple_set = true; | |
528 | } | |
529 | ||
530 | for (i = 0; i < nf_ct_helper_hsize; i++) { | |
b67bfe0d | 531 | hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) { |
12f7a505 PNA |
532 | |
533 | /* skip non-userspace conntrack helpers. */ | |
534 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
535 | continue; | |
536 | ||
537 | if (helper_name && strncmp(cur->name, helper_name, | |
538 | NF_CT_HELPER_NAME_LEN) != 0) { | |
539 | continue; | |
540 | } | |
541 | if (tuple_set && | |
542 | (tuple.src.l3num != cur->tuple.src.l3num || | |
543 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
544 | continue; | |
545 | ||
546 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
547 | if (skb2 == NULL) { | |
548 | ret = -ENOMEM; | |
549 | break; | |
550 | } | |
551 | ||
15e47304 | 552 | ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid, |
12f7a505 PNA |
553 | nlh->nlmsg_seq, |
554 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
555 | NFNL_MSG_CTHELPER_NEW, cur); | |
556 | if (ret <= 0) { | |
557 | kfree_skb(skb2); | |
558 | break; | |
559 | } | |
560 | ||
15e47304 | 561 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
12f7a505 PNA |
562 | MSG_DONTWAIT); |
563 | if (ret > 0) | |
564 | ret = 0; | |
565 | ||
566 | /* this avoids a loop in nfnetlink. */ | |
567 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
568 | } | |
569 | } | |
570 | return ret; | |
571 | } | |
572 | ||
573 | static int | |
574 | nfnl_cthelper_del(struct sock *nfnl, struct sk_buff *skb, | |
575 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
576 | { | |
577 | char *helper_name = NULL; | |
578 | struct nf_conntrack_helper *cur; | |
b67bfe0d | 579 | struct hlist_node *tmp; |
12f7a505 PNA |
580 | struct nf_conntrack_tuple tuple; |
581 | bool tuple_set = false, found = false; | |
582 | int i, j = 0, ret; | |
583 | ||
584 | if (tb[NFCTH_NAME]) | |
585 | helper_name = nla_data(tb[NFCTH_NAME]); | |
586 | ||
587 | if (tb[NFCTH_TUPLE]) { | |
588 | ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); | |
589 | if (ret < 0) | |
590 | return ret; | |
591 | ||
592 | tuple_set = true; | |
593 | } | |
594 | ||
595 | for (i = 0; i < nf_ct_helper_hsize; i++) { | |
b67bfe0d | 596 | hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i], |
12f7a505 PNA |
597 | hnode) { |
598 | /* skip non-userspace conntrack helpers. */ | |
599 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
600 | continue; | |
601 | ||
602 | j++; | |
603 | ||
604 | if (helper_name && strncmp(cur->name, helper_name, | |
605 | NF_CT_HELPER_NAME_LEN) != 0) { | |
606 | continue; | |
607 | } | |
608 | if (tuple_set && | |
609 | (tuple.src.l3num != cur->tuple.src.l3num || | |
610 | tuple.dst.protonum != cur->tuple.dst.protonum)) | |
611 | continue; | |
612 | ||
613 | found = true; | |
614 | nf_conntrack_helper_unregister(cur); | |
615 | } | |
616 | } | |
617 | /* Make sure we return success if we flush and there is no helpers */ | |
618 | return (found || j == 0) ? 0 : -ENOENT; | |
619 | } | |
620 | ||
621 | static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { | |
622 | [NFCTH_NAME] = { .type = NLA_NUL_STRING, | |
623 | .len = NF_CT_HELPER_NAME_LEN-1 }, | |
624 | [NFCTH_QUEUE_NUM] = { .type = NLA_U32, }, | |
625 | }; | |
626 | ||
627 | static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = { | |
628 | [NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new, | |
629 | .attr_count = NFCTH_MAX, | |
630 | .policy = nfnl_cthelper_policy }, | |
631 | [NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get, | |
632 | .attr_count = NFCTH_MAX, | |
633 | .policy = nfnl_cthelper_policy }, | |
634 | [NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del, | |
635 | .attr_count = NFCTH_MAX, | |
636 | .policy = nfnl_cthelper_policy }, | |
637 | }; | |
638 | ||
639 | static const struct nfnetlink_subsystem nfnl_cthelper_subsys = { | |
640 | .name = "cthelper", | |
641 | .subsys_id = NFNL_SUBSYS_CTHELPER, | |
642 | .cb_count = NFNL_MSG_CTHELPER_MAX, | |
643 | .cb = nfnl_cthelper_cb, | |
644 | }; | |
645 | ||
646 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER); | |
647 | ||
648 | static int __init nfnl_cthelper_init(void) | |
649 | { | |
650 | int ret; | |
651 | ||
652 | ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys); | |
653 | if (ret < 0) { | |
654 | pr_err("nfnl_cthelper: cannot register with nfnetlink.\n"); | |
655 | goto err_out; | |
656 | } | |
657 | return 0; | |
658 | err_out: | |
659 | return ret; | |
660 | } | |
661 | ||
662 | static void __exit nfnl_cthelper_exit(void) | |
663 | { | |
664 | struct nf_conntrack_helper *cur; | |
b67bfe0d | 665 | struct hlist_node *tmp; |
12f7a505 PNA |
666 | int i; |
667 | ||
668 | nfnetlink_subsys_unregister(&nfnl_cthelper_subsys); | |
669 | ||
670 | for (i=0; i<nf_ct_helper_hsize; i++) { | |
b67bfe0d | 671 | hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i], |
12f7a505 PNA |
672 | hnode) { |
673 | /* skip non-userspace conntrack helpers. */ | |
674 | if (!(cur->flags & NF_CT_HELPER_F_USERSPACE)) | |
675 | continue; | |
676 | ||
677 | nf_conntrack_helper_unregister(cur); | |
678 | } | |
679 | } | |
680 | } | |
681 | ||
682 | module_init(nfnl_cthelper_init); | |
683 | module_exit(nfnl_cthelper_exit); |