Commit | Line | Data |
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50978462 PNA |
1 | /* |
2 | * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org> | |
3 | * (C) 2012 by Vyatta Inc. <http://www.vyatta.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation (or any later at your option). | |
8 | */ | |
9 | #include <linux/init.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/rculist.h> | |
13 | #include <linux/rculist_nulls.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/timer.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/netlink.h> | |
20 | #include <linux/spinlock.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/slab.h> | |
23 | ||
24 | #include <linux/netfilter.h> | |
25 | #include <net/netlink.h> | |
26 | #include <net/sock.h> | |
27 | #include <net/netfilter/nf_conntrack.h> | |
28 | #include <net/netfilter/nf_conntrack_core.h> | |
29 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
30 | #include <net/netfilter/nf_conntrack_l4proto.h> | |
31 | #include <net/netfilter/nf_conntrack_tuple.h> | |
24de58f4 | 32 | #include <net/netfilter/nf_conntrack_timeout.h> |
50978462 PNA |
33 | |
34 | #include <linux/netfilter/nfnetlink.h> | |
35 | #include <linux/netfilter/nfnetlink_cttimeout.h> | |
36 | ||
37 | MODULE_LICENSE("GPL"); | |
38 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
39 | MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning"); | |
40 | ||
50978462 PNA |
41 | static LIST_HEAD(cttimeout_list); |
42 | ||
43 | static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = { | |
e93b5f9f FW |
44 | [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING, |
45 | .len = CTNL_TIMEOUT_NAME_MAX - 1}, | |
50978462 PNA |
46 | [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 }, |
47 | [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 }, | |
48 | [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED }, | |
49 | }; | |
50 | ||
51 | static int | |
52 | ctnl_timeout_parse_policy(struct ctnl_timeout *timeout, | |
8264deb8 G |
53 | struct nf_conntrack_l4proto *l4proto, |
54 | struct net *net, | |
55 | const struct nlattr *attr) | |
50978462 PNA |
56 | { |
57 | int ret = 0; | |
58 | ||
59 | if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) { | |
60 | struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1]; | |
61 | ||
130ffbc2 DB |
62 | ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, |
63 | attr, l4proto->ctnl_timeout.nla_policy); | |
64 | if (ret < 0) | |
65 | return ret; | |
50978462 | 66 | |
8264deb8 G |
67 | ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, |
68 | &timeout->data); | |
50978462 PNA |
69 | } |
70 | return ret; | |
71 | } | |
72 | ||
73 | static int | |
74 | cttimeout_new_timeout(struct sock *ctnl, struct sk_buff *skb, | |
75 | const struct nlmsghdr *nlh, | |
76 | const struct nlattr * const cda[]) | |
77 | { | |
78 | __u16 l3num; | |
79 | __u8 l4num; | |
80 | struct nf_conntrack_l4proto *l4proto; | |
81 | struct ctnl_timeout *timeout, *matching = NULL; | |
8264deb8 | 82 | struct net *net = sock_net(skb->sk); |
50978462 PNA |
83 | char *name; |
84 | int ret; | |
85 | ||
86 | if (!cda[CTA_TIMEOUT_NAME] || | |
87 | !cda[CTA_TIMEOUT_L3PROTO] || | |
88 | !cda[CTA_TIMEOUT_L4PROTO] || | |
89 | !cda[CTA_TIMEOUT_DATA]) | |
90 | return -EINVAL; | |
91 | ||
92 | name = nla_data(cda[CTA_TIMEOUT_NAME]); | |
93 | l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO])); | |
94 | l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]); | |
95 | ||
96 | list_for_each_entry(timeout, &cttimeout_list, head) { | |
97 | if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) | |
98 | continue; | |
99 | ||
100 | if (nlh->nlmsg_flags & NLM_F_EXCL) | |
101 | return -EEXIST; | |
102 | ||
103 | matching = timeout; | |
104 | break; | |
105 | } | |
106 | ||
c1ebd7df | 107 | l4proto = nf_ct_l4proto_find_get(l3num, l4num); |
50978462 PNA |
108 | |
109 | /* This protocol is not supportted, skip. */ | |
c1ebd7df PNA |
110 | if (l4proto->l4proto != l4num) { |
111 | ret = -EOPNOTSUPP; | |
112 | goto err_proto_put; | |
113 | } | |
50978462 PNA |
114 | |
115 | if (matching) { | |
116 | if (nlh->nlmsg_flags & NLM_F_REPLACE) { | |
117 | /* You cannot replace one timeout policy by another of | |
118 | * different kind, sorry. | |
119 | */ | |
120 | if (matching->l3num != l3num || | |
c1ebd7df PNA |
121 | matching->l4proto->l4proto != l4num) { |
122 | ret = -EINVAL; | |
123 | goto err_proto_put; | |
124 | } | |
50978462 | 125 | |
8264deb8 | 126 | ret = ctnl_timeout_parse_policy(matching, l4proto, net, |
50978462 PNA |
127 | cda[CTA_TIMEOUT_DATA]); |
128 | return ret; | |
129 | } | |
c1ebd7df PNA |
130 | ret = -EBUSY; |
131 | goto err_proto_put; | |
50978462 PNA |
132 | } |
133 | ||
134 | timeout = kzalloc(sizeof(struct ctnl_timeout) + | |
135 | l4proto->ctnl_timeout.obj_size, GFP_KERNEL); | |
c1ebd7df PNA |
136 | if (timeout == NULL) { |
137 | ret = -ENOMEM; | |
138 | goto err_proto_put; | |
139 | } | |
50978462 | 140 | |
8264deb8 | 141 | ret = ctnl_timeout_parse_policy(timeout, l4proto, net, |
50978462 PNA |
142 | cda[CTA_TIMEOUT_DATA]); |
143 | if (ret < 0) | |
144 | goto err; | |
145 | ||
146 | strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME])); | |
147 | timeout->l3num = l3num; | |
c1ebd7df | 148 | timeout->l4proto = l4proto; |
50978462 PNA |
149 | atomic_set(&timeout->refcnt, 1); |
150 | list_add_tail_rcu(&timeout->head, &cttimeout_list); | |
151 | ||
152 | return 0; | |
153 | err: | |
154 | kfree(timeout); | |
c1ebd7df PNA |
155 | err_proto_put: |
156 | nf_ct_l4proto_put(l4proto); | |
50978462 PNA |
157 | return ret; |
158 | } | |
159 | ||
160 | static int | |
15e47304 | 161 | ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
50978462 PNA |
162 | int event, struct ctnl_timeout *timeout) |
163 | { | |
164 | struct nlmsghdr *nlh; | |
165 | struct nfgenmsg *nfmsg; | |
15e47304 | 166 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
c1ebd7df | 167 | struct nf_conntrack_l4proto *l4proto = timeout->l4proto; |
50978462 PNA |
168 | |
169 | event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8; | |
15e47304 | 170 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); |
50978462 PNA |
171 | if (nlh == NULL) |
172 | goto nlmsg_failure; | |
173 | ||
174 | nfmsg = nlmsg_data(nlh); | |
175 | nfmsg->nfgen_family = AF_UNSPEC; | |
176 | nfmsg->version = NFNETLINK_V0; | |
177 | nfmsg->res_id = 0; | |
178 | ||
48f03bda DM |
179 | if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) || |
180 | nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) || | |
181 | nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) || | |
182 | nla_put_be32(skb, CTA_TIMEOUT_USE, | |
183 | htonl(atomic_read(&timeout->refcnt)))) | |
184 | goto nla_put_failure; | |
50978462 | 185 | |
50978462 PNA |
186 | if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) { |
187 | struct nlattr *nest_parms; | |
188 | int ret; | |
189 | ||
190 | nest_parms = nla_nest_start(skb, | |
191 | CTA_TIMEOUT_DATA | NLA_F_NESTED); | |
192 | if (!nest_parms) | |
193 | goto nla_put_failure; | |
194 | ||
195 | ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data); | |
196 | if (ret < 0) | |
197 | goto nla_put_failure; | |
198 | ||
199 | nla_nest_end(skb, nest_parms); | |
200 | } | |
c1ebd7df | 201 | |
50978462 PNA |
202 | nlmsg_end(skb, nlh); |
203 | return skb->len; | |
204 | ||
205 | nlmsg_failure: | |
206 | nla_put_failure: | |
207 | nlmsg_cancel(skb, nlh); | |
208 | return -1; | |
209 | } | |
210 | ||
211 | static int | |
212 | ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb) | |
213 | { | |
214 | struct ctnl_timeout *cur, *last; | |
215 | ||
216 | if (cb->args[2]) | |
217 | return 0; | |
218 | ||
219 | last = (struct ctnl_timeout *)cb->args[1]; | |
220 | if (cb->args[1]) | |
221 | cb->args[1] = 0; | |
222 | ||
223 | rcu_read_lock(); | |
224 | list_for_each_entry_rcu(cur, &cttimeout_list, head) { | |
37bc4f8d PNA |
225 | if (last) { |
226 | if (cur != last) | |
227 | continue; | |
50978462 | 228 | |
37bc4f8d PNA |
229 | last = NULL; |
230 | } | |
15e47304 | 231 | if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid, |
50978462 PNA |
232 | cb->nlh->nlmsg_seq, |
233 | NFNL_MSG_TYPE(cb->nlh->nlmsg_type), | |
234 | IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) { | |
235 | cb->args[1] = (unsigned long)cur; | |
236 | break; | |
237 | } | |
238 | } | |
239 | if (!cb->args[1]) | |
240 | cb->args[2] = 1; | |
241 | rcu_read_unlock(); | |
242 | return skb->len; | |
243 | } | |
244 | ||
245 | static int | |
246 | cttimeout_get_timeout(struct sock *ctnl, struct sk_buff *skb, | |
247 | const struct nlmsghdr *nlh, | |
248 | const struct nlattr * const cda[]) | |
249 | { | |
250 | int ret = -ENOENT; | |
251 | char *name; | |
252 | struct ctnl_timeout *cur; | |
253 | ||
254 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | |
255 | struct netlink_dump_control c = { | |
256 | .dump = ctnl_timeout_dump, | |
257 | }; | |
258 | return netlink_dump_start(ctnl, skb, nlh, &c); | |
259 | } | |
260 | ||
261 | if (!cda[CTA_TIMEOUT_NAME]) | |
262 | return -EINVAL; | |
263 | name = nla_data(cda[CTA_TIMEOUT_NAME]); | |
264 | ||
265 | list_for_each_entry(cur, &cttimeout_list, head) { | |
266 | struct sk_buff *skb2; | |
267 | ||
268 | if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) | |
269 | continue; | |
270 | ||
271 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
272 | if (skb2 == NULL) { | |
273 | ret = -ENOMEM; | |
274 | break; | |
275 | } | |
276 | ||
15e47304 | 277 | ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid, |
50978462 PNA |
278 | nlh->nlmsg_seq, |
279 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
280 | IPCTNL_MSG_TIMEOUT_NEW, cur); | |
281 | if (ret <= 0) { | |
282 | kfree_skb(skb2); | |
283 | break; | |
284 | } | |
15e47304 | 285 | ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, |
50978462 PNA |
286 | MSG_DONTWAIT); |
287 | if (ret > 0) | |
288 | ret = 0; | |
289 | ||
290 | /* this avoids a loop in nfnetlink. */ | |
291 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
292 | } | |
293 | return ret; | |
294 | } | |
295 | ||
296 | /* try to delete object, fail if it is still in use. */ | |
297 | static int ctnl_timeout_try_del(struct ctnl_timeout *timeout) | |
298 | { | |
299 | int ret = 0; | |
300 | ||
301 | /* we want to avoid races with nf_ct_timeout_find_get. */ | |
302 | if (atomic_dec_and_test(&timeout->refcnt)) { | |
303 | /* We are protected by nfnl mutex. */ | |
304 | list_del_rcu(&timeout->head); | |
c1ebd7df | 305 | nf_ct_l4proto_put(timeout->l4proto); |
50978462 PNA |
306 | kfree_rcu(timeout, rcu_head); |
307 | } else { | |
308 | /* still in use, restore reference counter. */ | |
309 | atomic_inc(&timeout->refcnt); | |
310 | ret = -EBUSY; | |
311 | } | |
312 | return ret; | |
313 | } | |
314 | ||
315 | static int | |
316 | cttimeout_del_timeout(struct sock *ctnl, struct sk_buff *skb, | |
317 | const struct nlmsghdr *nlh, | |
318 | const struct nlattr * const cda[]) | |
319 | { | |
320 | char *name; | |
321 | struct ctnl_timeout *cur; | |
322 | int ret = -ENOENT; | |
323 | ||
324 | if (!cda[CTA_TIMEOUT_NAME]) { | |
325 | list_for_each_entry(cur, &cttimeout_list, head) | |
326 | ctnl_timeout_try_del(cur); | |
327 | ||
328 | return 0; | |
329 | } | |
330 | name = nla_data(cda[CTA_TIMEOUT_NAME]); | |
331 | ||
332 | list_for_each_entry(cur, &cttimeout_list, head) { | |
333 | if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) | |
334 | continue; | |
335 | ||
336 | ret = ctnl_timeout_try_del(cur); | |
337 | if (ret < 0) | |
338 | return ret; | |
339 | ||
340 | break; | |
341 | } | |
342 | return ret; | |
343 | } | |
344 | ||
24de58f4 PNA |
345 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
346 | static struct ctnl_timeout *ctnl_timeout_find_get(const char *name) | |
347 | { | |
348 | struct ctnl_timeout *timeout, *matching = NULL; | |
349 | ||
350 | rcu_read_lock(); | |
351 | list_for_each_entry_rcu(timeout, &cttimeout_list, head) { | |
352 | if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) | |
353 | continue; | |
354 | ||
355 | if (!try_module_get(THIS_MODULE)) | |
356 | goto err; | |
357 | ||
358 | if (!atomic_inc_not_zero(&timeout->refcnt)) { | |
359 | module_put(THIS_MODULE); | |
360 | goto err; | |
361 | } | |
362 | matching = timeout; | |
363 | break; | |
364 | } | |
365 | err: | |
366 | rcu_read_unlock(); | |
367 | return matching; | |
368 | } | |
369 | ||
370 | static void ctnl_timeout_put(struct ctnl_timeout *timeout) | |
371 | { | |
372 | atomic_dec(&timeout->refcnt); | |
373 | module_put(THIS_MODULE); | |
374 | } | |
375 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ | |
376 | ||
50978462 PNA |
377 | static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = { |
378 | [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout, | |
379 | .attr_count = CTA_TIMEOUT_MAX, | |
380 | .policy = cttimeout_nla_policy }, | |
381 | [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout, | |
382 | .attr_count = CTA_TIMEOUT_MAX, | |
383 | .policy = cttimeout_nla_policy }, | |
384 | [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout, | |
385 | .attr_count = CTA_TIMEOUT_MAX, | |
386 | .policy = cttimeout_nla_policy }, | |
387 | }; | |
388 | ||
389 | static const struct nfnetlink_subsystem cttimeout_subsys = { | |
390 | .name = "conntrack_timeout", | |
391 | .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT, | |
392 | .cb_count = IPCTNL_MSG_TIMEOUT_MAX, | |
393 | .cb = cttimeout_cb, | |
394 | }; | |
395 | ||
396 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT); | |
397 | ||
398 | static int __init cttimeout_init(void) | |
399 | { | |
400 | int ret; | |
401 | ||
402 | ret = nfnetlink_subsys_register(&cttimeout_subsys); | |
403 | if (ret < 0) { | |
404 | pr_err("cttimeout_init: cannot register cttimeout with " | |
405 | "nfnetlink.\n"); | |
406 | goto err_out; | |
407 | } | |
24de58f4 PNA |
408 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
409 | RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get); | |
410 | RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put); | |
411 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ | |
50978462 PNA |
412 | return 0; |
413 | ||
414 | err_out: | |
415 | return ret; | |
416 | } | |
417 | ||
418 | static void __exit cttimeout_exit(void) | |
419 | { | |
420 | struct ctnl_timeout *cur, *tmp; | |
421 | ||
422 | pr_info("cttimeout: unregistering from nfnetlink.\n"); | |
423 | ||
424 | nfnetlink_subsys_unregister(&cttimeout_subsys); | |
425 | list_for_each_entry_safe(cur, tmp, &cttimeout_list, head) { | |
426 | list_del_rcu(&cur->head); | |
427 | /* We are sure that our objects have no clients at this point, | |
428 | * it's safe to release them all without checking refcnt. | |
429 | */ | |
c1ebd7df | 430 | nf_ct_l4proto_put(cur->l4proto); |
50978462 PNA |
431 | kfree_rcu(cur, rcu_head); |
432 | } | |
24de58f4 PNA |
433 | #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
434 | RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL); | |
435 | RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL); | |
436 | #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ | |
50978462 PNA |
437 | } |
438 | ||
439 | module_init(cttimeout_init); | |
440 | module_exit(cttimeout_exit); |