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Commit | Line | Data |
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f9e815b3 HW |
1 | /* Netfilter messages via netlink socket. Allows for user space |
2 | * protocol helpers and general trouble making from userspace. | |
3 | * | |
4 | * (C) 2001 by Jay Schulist <jschlst@samba.org>, | |
5 | * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org> | |
8c4d4e8b | 6 | * (C) 2005-2017 by Pablo Neira Ayuso <pablo@netfilter.org> |
f9e815b3 HW |
7 | * |
8 | * Initial netfilter messages via netlink development funded and | |
9 | * generally made possible by Network Robots, Inc. (www.networkrobots.com) | |
10 | * | |
11 | * Further development of this code funded by Astaro AG (http://www.astaro.com) | |
12 | * | |
13 | * This software may be used and distributed according to the terms | |
14 | * of the GNU General Public License, incorporated herein by reference. | |
15 | */ | |
16 | ||
f9e815b3 HW |
17 | #include <linux/module.h> |
18 | #include <linux/types.h> | |
19 | #include <linux/socket.h> | |
20 | #include <linux/kernel.h> | |
f9e815b3 HW |
21 | #include <linux/string.h> |
22 | #include <linux/sockios.h> | |
23 | #include <linux/net.h> | |
f9e815b3 | 24 | #include <linux/skbuff.h> |
7c0f6ba6 | 25 | #include <linux/uaccess.h> |
f9e815b3 HW |
26 | #include <net/sock.h> |
27 | #include <linux/init.h> | |
f9e815b3 | 28 | |
573ce260 | 29 | #include <net/netlink.h> |
f9e815b3 HW |
30 | #include <linux/netfilter/nfnetlink.h> |
31 | ||
32 | MODULE_LICENSE("GPL"); | |
4fdb3bb7 HW |
33 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
34 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); | |
f9e815b3 | 35 | |
9c55d3b5 FW |
36 | #define nfnl_dereference_protected(id) \ |
37 | rcu_dereference_protected(table[(id)].subsys, \ | |
38 | lockdep_nfnl_is_held((id))) | |
39 | ||
f9e815b3 HW |
40 | static char __initdata nfversion[] = "0.30"; |
41 | ||
c14b78e7 PNA |
42 | static struct { |
43 | struct mutex mutex; | |
44 | const struct nfnetlink_subsystem __rcu *subsys; | |
45 | } table[NFNL_SUBSYS_COUNT]; | |
f9e815b3 | 46 | |
03292745 PNA |
47 | static const int nfnl_group2type[NFNLGRP_MAX+1] = { |
48 | [NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK, | |
49 | [NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK, | |
50 | [NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK, | |
51 | [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, | |
52 | [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, | |
53 | [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, | |
97840cb6 PNA |
54 | [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, |
55 | [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, | |
33d5a7b1 | 56 | [NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES, |
03292745 PNA |
57 | }; |
58 | ||
c14b78e7 | 59 | void nfnl_lock(__u8 subsys_id) |
f9e815b3 | 60 | { |
c14b78e7 | 61 | mutex_lock(&table[subsys_id].mutex); |
f9e815b3 | 62 | } |
e6a7d3c0 | 63 | EXPORT_SYMBOL_GPL(nfnl_lock); |
f9e815b3 | 64 | |
c14b78e7 | 65 | void nfnl_unlock(__u8 subsys_id) |
a3c5029c | 66 | { |
c14b78e7 | 67 | mutex_unlock(&table[subsys_id].mutex); |
f9e815b3 | 68 | } |
e6a7d3c0 | 69 | EXPORT_SYMBOL_GPL(nfnl_unlock); |
f9e815b3 | 70 | |
0eb5db7a | 71 | #ifdef CONFIG_PROVE_LOCKING |
875e0829 | 72 | bool lockdep_nfnl_is_held(u8 subsys_id) |
0eb5db7a PM |
73 | { |
74 | return lockdep_is_held(&table[subsys_id].mutex); | |
75 | } | |
76 | EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held); | |
77 | #endif | |
78 | ||
7c8d4cb4 | 79 | int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) |
f9e815b3 | 80 | { |
c14b78e7 PNA |
81 | nfnl_lock(n->subsys_id); |
82 | if (table[n->subsys_id].subsys) { | |
83 | nfnl_unlock(n->subsys_id); | |
0ab43f84 HW |
84 | return -EBUSY; |
85 | } | |
c14b78e7 PNA |
86 | rcu_assign_pointer(table[n->subsys_id].subsys, n); |
87 | nfnl_unlock(n->subsys_id); | |
f9e815b3 HW |
88 | |
89 | return 0; | |
90 | } | |
f4bc177f | 91 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); |
f9e815b3 | 92 | |
7c8d4cb4 | 93 | int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) |
f9e815b3 | 94 | { |
c14b78e7 PNA |
95 | nfnl_lock(n->subsys_id); |
96 | table[n->subsys_id].subsys = NULL; | |
97 | nfnl_unlock(n->subsys_id); | |
6b75e3e8 | 98 | synchronize_rcu(); |
f9e815b3 HW |
99 | return 0; |
100 | } | |
f4bc177f | 101 | EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); |
f9e815b3 | 102 | |
b745d035 | 103 | static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u16 type) |
f9e815b3 | 104 | { |
b745d035 | 105 | u8 subsys_id = NFNL_SUBSYS_ID(type); |
f9e815b3 | 106 | |
ac0f1d98 | 107 | if (subsys_id >= NFNL_SUBSYS_COUNT) |
f9e815b3 HW |
108 | return NULL; |
109 | ||
c14b78e7 | 110 | return rcu_dereference(table[subsys_id].subsys); |
f9e815b3 HW |
111 | } |
112 | ||
7c8d4cb4 | 113 | static inline const struct nfnl_callback * |
b745d035 | 114 | nfnetlink_find_client(u16 type, const struct nfnetlink_subsystem *ss) |
f9e815b3 | 115 | { |
b745d035 | 116 | u8 cb_id = NFNL_MSG_TYPE(type); |
601e68e1 | 117 | |
67ca3966 | 118 | if (cb_id >= ss->cb_count) |
f9e815b3 | 119 | return NULL; |
f9e815b3 HW |
120 | |
121 | return &ss->cb[cb_id]; | |
122 | } | |
123 | ||
cd8c20b6 | 124 | int nfnetlink_has_listeners(struct net *net, unsigned int group) |
a2427692 | 125 | { |
cd8c20b6 | 126 | return netlink_has_listeners(net->nfnl, group); |
a2427692 PM |
127 | } |
128 | EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); | |
129 | ||
ec464e5d | 130 | int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, |
95c96174 | 131 | unsigned int group, int echo, gfp_t flags) |
f9e815b3 | 132 | { |
ec464e5d | 133 | return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags); |
f9e815b3 | 134 | } |
f4bc177f | 135 | EXPORT_SYMBOL_GPL(nfnetlink_send); |
f9e815b3 | 136 | |
ec464e5d | 137 | int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) |
dd5b6ce6 | 138 | { |
ec464e5d | 139 | return netlink_set_err(net->nfnl, portid, group, error); |
dd5b6ce6 PNA |
140 | } |
141 | EXPORT_SYMBOL_GPL(nfnetlink_set_err); | |
142 | ||
ec464e5d PM |
143 | int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid, |
144 | int flags) | |
f9e815b3 | 145 | { |
ec464e5d | 146 | return netlink_unicast(net->nfnl, skb, portid, flags); |
f9e815b3 | 147 | } |
f4bc177f | 148 | EXPORT_SYMBOL_GPL(nfnetlink_unicast); |
f9e815b3 HW |
149 | |
150 | /* Process one complete nfnetlink message. */ | |
1d00a4eb | 151 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
f9e815b3 | 152 | { |
cd8c20b6 | 153 | struct net *net = sock_net(skb->sk); |
7c8d4cb4 PM |
154 | const struct nfnl_callback *nc; |
155 | const struct nfnetlink_subsystem *ss; | |
1d00a4eb | 156 | int type, err; |
f9e815b3 | 157 | |
f9e815b3 | 158 | /* All the messages must at least contain nfgenmsg */ |
573ce260 | 159 | if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) |
f9e815b3 | 160 | return 0; |
f9e815b3 HW |
161 | |
162 | type = nlh->nlmsg_type; | |
e6a7d3c0 | 163 | replay: |
6b75e3e8 | 164 | rcu_read_lock(); |
f9e815b3 | 165 | ss = nfnetlink_get_subsys(type); |
0ab43f84 | 166 | if (!ss) { |
95a5afca | 167 | #ifdef CONFIG_MODULES |
6b75e3e8 | 168 | rcu_read_unlock(); |
37d2e7a2 | 169 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
6b75e3e8 | 170 | rcu_read_lock(); |
37d2e7a2 | 171 | ss = nfnetlink_get_subsys(type); |
0ab43f84 HW |
172 | if (!ss) |
173 | #endif | |
6b75e3e8 ED |
174 | { |
175 | rcu_read_unlock(); | |
1d00a4eb | 176 | return -EINVAL; |
6b75e3e8 | 177 | } |
0ab43f84 | 178 | } |
f9e815b3 HW |
179 | |
180 | nc = nfnetlink_find_client(type, ss); | |
6b75e3e8 ED |
181 | if (!nc) { |
182 | rcu_read_unlock(); | |
1d00a4eb | 183 | return -EINVAL; |
6b75e3e8 | 184 | } |
f9e815b3 | 185 | |
f9e815b3 | 186 | { |
573ce260 | 187 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
b745d035 | 188 | u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
f49c857f PNA |
189 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
190 | struct nlattr *attr = (void *)nlh + min_len; | |
191 | int attrlen = nlh->nlmsg_len - min_len; | |
c14b78e7 | 192 | __u8 subsys_id = NFNL_SUBSYS_ID(type); |
f49c857f PNA |
193 | |
194 | err = nla_parse(cda, ss->cb[cb_id].attr_count, | |
195 | attr, attrlen, ss->cb[cb_id].policy); | |
4009e188 TB |
196 | if (err < 0) { |
197 | rcu_read_unlock(); | |
f49c857f | 198 | return err; |
4009e188 | 199 | } |
601e68e1 | 200 | |
6b75e3e8 | 201 | if (nc->call_rcu) { |
7b8002a1 | 202 | err = nc->call_rcu(net, net->nfnl, skb, nlh, |
6b75e3e8 ED |
203 | (const struct nlattr **)cda); |
204 | rcu_read_unlock(); | |
205 | } else { | |
206 | rcu_read_unlock(); | |
c14b78e7 | 207 | nfnl_lock(subsys_id); |
9c55d3b5 | 208 | if (nfnl_dereference_protected(subsys_id) != ss || |
6b75e3e8 ED |
209 | nfnetlink_find_client(type, ss) != nc) |
210 | err = -EAGAIN; | |
59560a38 | 211 | else if (nc->call) |
7b8002a1 PNA |
212 | err = nc->call(net, net->nfnl, skb, nlh, |
213 | (const struct nlattr **)cda); | |
59560a38 TB |
214 | else |
215 | err = -EINVAL; | |
c14b78e7 | 216 | nfnl_unlock(subsys_id); |
6b75e3e8 | 217 | } |
e6a7d3c0 PNA |
218 | if (err == -EAGAIN) |
219 | goto replay; | |
220 | return err; | |
f9e815b3 | 221 | } |
f9e815b3 HW |
222 | } |
223 | ||
cbb8125e PNA |
224 | struct nfnl_err { |
225 | struct list_head head; | |
226 | struct nlmsghdr *nlh; | |
227 | int err; | |
228 | }; | |
229 | ||
230 | static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err) | |
231 | { | |
232 | struct nfnl_err *nfnl_err; | |
233 | ||
234 | nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); | |
235 | if (nfnl_err == NULL) | |
236 | return -ENOMEM; | |
237 | ||
238 | nfnl_err->nlh = nlh; | |
239 | nfnl_err->err = err; | |
240 | list_add_tail(&nfnl_err->head, list); | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
245 | static void nfnl_err_del(struct nfnl_err *nfnl_err) | |
246 | { | |
247 | list_del(&nfnl_err->head); | |
248 | kfree(nfnl_err); | |
249 | } | |
250 | ||
251 | static void nfnl_err_reset(struct list_head *err_list) | |
252 | { | |
253 | struct nfnl_err *nfnl_err, *next; | |
254 | ||
255 | list_for_each_entry_safe(nfnl_err, next, err_list, head) | |
256 | nfnl_err_del(nfnl_err); | |
257 | } | |
258 | ||
259 | static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) | |
260 | { | |
261 | struct nfnl_err *nfnl_err, *next; | |
262 | ||
263 | list_for_each_entry_safe(nfnl_err, next, err_list, head) { | |
264 | netlink_ack(skb, nfnl_err->nlh, nfnl_err->err); | |
265 | nfnl_err_del(nfnl_err); | |
266 | } | |
267 | } | |
268 | ||
6742b9e3 PNA |
269 | enum { |
270 | NFNL_BATCH_FAILURE = (1 << 0), | |
271 | NFNL_BATCH_DONE = (1 << 1), | |
272 | NFNL_BATCH_REPLAY = (1 << 2), | |
273 | }; | |
274 | ||
0628b123 | 275 | static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, |
8c4d4e8b | 276 | u16 subsys_id, u32 genid) |
0628b123 | 277 | { |
0f816232 | 278 | struct sk_buff *oskb = skb; |
0628b123 PNA |
279 | struct net *net = sock_net(skb->sk); |
280 | const struct nfnetlink_subsystem *ss; | |
281 | const struct nfnl_callback *nc; | |
4eba8b78 | 282 | LIST_HEAD(err_list); |
6742b9e3 | 283 | u32 status; |
0628b123 PNA |
284 | int err; |
285 | ||
286 | if (subsys_id >= NFNL_SUBSYS_COUNT) | |
287 | return netlink_ack(skb, nlh, -EINVAL); | |
288 | replay: | |
6742b9e3 PNA |
289 | status = 0; |
290 | ||
0f816232 DJ |
291 | skb = netlink_skb_clone(oskb, GFP_KERNEL); |
292 | if (!skb) | |
0628b123 PNA |
293 | return netlink_ack(oskb, nlh, -ENOMEM); |
294 | ||
0628b123 | 295 | nfnl_lock(subsys_id); |
9c55d3b5 | 296 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
297 | if (!ss) { |
298 | #ifdef CONFIG_MODULES | |
299 | nfnl_unlock(subsys_id); | |
300 | request_module("nfnetlink-subsys-%d", subsys_id); | |
301 | nfnl_lock(subsys_id); | |
9c55d3b5 | 302 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
303 | if (!ss) |
304 | #endif | |
305 | { | |
306 | nfnl_unlock(subsys_id); | |
7c7bdf35 | 307 | netlink_ack(oskb, nlh, -EOPNOTSUPP); |
0f816232 | 308 | return kfree_skb(skb); |
0628b123 PNA |
309 | } |
310 | } | |
311 | ||
312 | if (!ss->commit || !ss->abort) { | |
313 | nfnl_unlock(subsys_id); | |
7c7bdf35 | 314 | netlink_ack(oskb, nlh, -EOPNOTSUPP); |
ecd15dd7 | 315 | return kfree_skb(skb); |
0628b123 PNA |
316 | } |
317 | ||
8c4d4e8b PNA |
318 | if (genid && ss->valid_genid && !ss->valid_genid(net, genid)) { |
319 | nfnl_unlock(subsys_id); | |
320 | netlink_ack(oskb, nlh, -ERESTART); | |
321 | return kfree_skb(skb); | |
322 | } | |
323 | ||
0628b123 PNA |
324 | while (skb->len >= nlmsg_total_size(0)) { |
325 | int msglen, type; | |
326 | ||
327 | nlh = nlmsg_hdr(skb); | |
328 | err = 0; | |
329 | ||
c58d6c93 PT |
330 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
331 | skb->len < nlh->nlmsg_len || | |
332 | nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { | |
333 | nfnl_err_reset(&err_list); | |
334 | status |= NFNL_BATCH_FAILURE; | |
335 | goto done; | |
0628b123 PNA |
336 | } |
337 | ||
338 | /* Only requests are handled by the kernel */ | |
339 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { | |
340 | err = -EINVAL; | |
341 | goto ack; | |
342 | } | |
343 | ||
344 | type = nlh->nlmsg_type; | |
345 | if (type == NFNL_MSG_BATCH_BEGIN) { | |
346 | /* Malformed: Batch begin twice */ | |
cbb8125e | 347 | nfnl_err_reset(&err_list); |
6742b9e3 | 348 | status |= NFNL_BATCH_FAILURE; |
0628b123 PNA |
349 | goto done; |
350 | } else if (type == NFNL_MSG_BATCH_END) { | |
6742b9e3 | 351 | status |= NFNL_BATCH_DONE; |
0628b123 PNA |
352 | goto done; |
353 | } else if (type < NLMSG_MIN_TYPE) { | |
354 | err = -EINVAL; | |
355 | goto ack; | |
356 | } | |
357 | ||
358 | /* We only accept a batch with messages for the same | |
359 | * subsystem. | |
360 | */ | |
361 | if (NFNL_SUBSYS_ID(type) != subsys_id) { | |
362 | err = -EINVAL; | |
363 | goto ack; | |
364 | } | |
365 | ||
366 | nc = nfnetlink_find_client(type, ss); | |
367 | if (!nc) { | |
368 | err = -EINVAL; | |
369 | goto ack; | |
370 | } | |
371 | ||
372 | { | |
373 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); | |
b745d035 | 374 | u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
0628b123 PNA |
375 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
376 | struct nlattr *attr = (void *)nlh + min_len; | |
377 | int attrlen = nlh->nlmsg_len - min_len; | |
378 | ||
379 | err = nla_parse(cda, ss->cb[cb_id].attr_count, | |
380 | attr, attrlen, ss->cb[cb_id].policy); | |
381 | if (err < 0) | |
382 | goto ack; | |
383 | ||
384 | if (nc->call_batch) { | |
633c9a84 | 385 | err = nc->call_batch(net, net->nfnl, skb, nlh, |
0628b123 PNA |
386 | (const struct nlattr **)cda); |
387 | } | |
388 | ||
389 | /* The lock was released to autoload some module, we | |
390 | * have to abort and start from scratch using the | |
391 | * original skb. | |
392 | */ | |
393 | if (err == -EAGAIN) { | |
6742b9e3 PNA |
394 | status |= NFNL_BATCH_REPLAY; |
395 | goto next; | |
0628b123 PNA |
396 | } |
397 | } | |
398 | ack: | |
399 | if (nlh->nlmsg_flags & NLM_F_ACK || err) { | |
cbb8125e PNA |
400 | /* Errors are delivered once the full batch has been |
401 | * processed, this avoids that the same error is | |
402 | * reported several times when replaying the batch. | |
403 | */ | |
404 | if (nfnl_err_add(&err_list, nlh, err) < 0) { | |
405 | /* We failed to enqueue an error, reset the | |
406 | * list of errors and send OOM to userspace | |
407 | * pointing to the batch header. | |
408 | */ | |
409 | nfnl_err_reset(&err_list); | |
7c7bdf35 | 410 | netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM); |
6742b9e3 | 411 | status |= NFNL_BATCH_FAILURE; |
cbb8125e PNA |
412 | goto done; |
413 | } | |
0628b123 PNA |
414 | /* We don't stop processing the batch on errors, thus, |
415 | * userspace gets all the errors that the batch | |
416 | * triggers. | |
417 | */ | |
0628b123 | 418 | if (err) |
6742b9e3 | 419 | status |= NFNL_BATCH_FAILURE; |
0628b123 | 420 | } |
6742b9e3 | 421 | next: |
0628b123 PNA |
422 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
423 | if (msglen > skb->len) | |
424 | msglen = skb->len; | |
425 | skb_pull(skb, msglen); | |
426 | } | |
427 | done: | |
6742b9e3 | 428 | if (status & NFNL_BATCH_REPLAY) { |
5913beaf | 429 | ss->abort(net, oskb); |
6742b9e3 PNA |
430 | nfnl_err_reset(&err_list); |
431 | nfnl_unlock(subsys_id); | |
432 | kfree_skb(skb); | |
433 | goto replay; | |
434 | } else if (status == NFNL_BATCH_DONE) { | |
5913beaf | 435 | ss->commit(net, oskb); |
6742b9e3 | 436 | } else { |
5913beaf | 437 | ss->abort(net, oskb); |
6742b9e3 | 438 | } |
0628b123 | 439 | |
cbb8125e | 440 | nfnl_err_deliver(&err_list, oskb); |
0628b123 | 441 | nfnl_unlock(subsys_id); |
0f816232 | 442 | kfree_skb(skb); |
0628b123 PNA |
443 | } |
444 | ||
8c4d4e8b PNA |
445 | static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = { |
446 | [NFNL_BATCH_GENID] = { .type = NLA_U32 }, | |
447 | }; | |
448 | ||
48656835 | 449 | static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh) |
f9e815b3 | 450 | { |
8c4d4e8b PNA |
451 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
452 | struct nlattr *attr = (void *)nlh + min_len; | |
453 | struct nlattr *cda[NFNL_BATCH_MAX + 1]; | |
454 | int attrlen = nlh->nlmsg_len - min_len; | |
48656835 | 455 | struct nfgenmsg *nfgenmsg; |
8c4d4e8b PNA |
456 | int msglen, err; |
457 | u32 gen_id = 0; | |
b745d035 | 458 | u16 res_id; |
0628b123 | 459 | |
48656835 PNA |
460 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
461 | if (msglen > skb->len) | |
462 | msglen = skb->len; | |
463 | ||
464 | if (nlh->nlmsg_len < NLMSG_HDRLEN || | |
465 | skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) | |
466 | return; | |
467 | ||
8c4d4e8b PNA |
468 | err = nla_parse(cda, NFNL_BATCH_MAX, attr, attrlen, nfnl_batch_policy); |
469 | if (err < 0) { | |
470 | netlink_ack(skb, nlh, err); | |
471 | return; | |
472 | } | |
473 | if (cda[NFNL_BATCH_GENID]) | |
474 | gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID])); | |
475 | ||
48656835 PNA |
476 | nfgenmsg = nlmsg_data(nlh); |
477 | skb_pull(skb, msglen); | |
478 | /* Work around old nft using host byte order */ | |
479 | if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) | |
480 | res_id = NFNL_SUBSYS_NFTABLES; | |
481 | else | |
482 | res_id = ntohs(nfgenmsg->res_id); | |
483 | ||
8c4d4e8b | 484 | nfnetlink_rcv_batch(skb, nlh, res_id, gen_id); |
48656835 PNA |
485 | } |
486 | ||
487 | static void nfnetlink_rcv(struct sk_buff *skb) | |
488 | { | |
489 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
490 | ||
0628b123 PNA |
491 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
492 | skb->len < nlh->nlmsg_len) | |
493 | return; | |
494 | ||
90f62cf3 | 495 | if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { |
cdbe7c2d JB |
496 | netlink_ack(skb, nlh, -EPERM); |
497 | return; | |
498 | } | |
499 | ||
48656835 PNA |
500 | if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) |
501 | nfnetlink_rcv_skb_batch(skb, nlh); | |
502 | else | |
0628b123 | 503 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); |
f9e815b3 HW |
504 | } |
505 | ||
03292745 | 506 | #ifdef CONFIG_MODULES |
023e2cfa | 507 | static int nfnetlink_bind(struct net *net, int group) |
03292745 PNA |
508 | { |
509 | const struct nfnetlink_subsystem *ss; | |
97840cb6 PNA |
510 | int type; |
511 | ||
512 | if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) | |
62924af2 | 513 | return 0; |
97840cb6 PNA |
514 | |
515 | type = nfnl_group2type[group]; | |
03292745 PNA |
516 | |
517 | rcu_read_lock(); | |
dbc3617f | 518 | ss = nfnetlink_get_subsys(type << 8); |
03292745 | 519 | rcu_read_unlock(); |
bfe4bc71 RGB |
520 | if (!ss) |
521 | request_module("nfnetlink-subsys-%d", type); | |
4f520900 | 522 | return 0; |
03292745 PNA |
523 | } |
524 | #endif | |
525 | ||
cd8c20b6 | 526 | static int __net_init nfnetlink_net_init(struct net *net) |
f9e815b3 | 527 | { |
cd8c20b6 | 528 | struct sock *nfnl; |
a31f2d17 PNA |
529 | struct netlink_kernel_cfg cfg = { |
530 | .groups = NFNLGRP_MAX, | |
531 | .input = nfnetlink_rcv, | |
03292745 PNA |
532 | #ifdef CONFIG_MODULES |
533 | .bind = nfnetlink_bind, | |
534 | #endif | |
a31f2d17 | 535 | }; |
cd8c20b6 | 536 | |
9f00d977 | 537 | nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); |
cd8c20b6 AD |
538 | if (!nfnl) |
539 | return -ENOMEM; | |
540 | net->nfnl_stash = nfnl; | |
cf778b00 | 541 | rcu_assign_pointer(net->nfnl, nfnl); |
cd8c20b6 | 542 | return 0; |
f9e815b3 HW |
543 | } |
544 | ||
cd8c20b6 | 545 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
f9e815b3 | 546 | { |
cd8c20b6 | 547 | struct net *net; |
f9e815b3 | 548 | |
cd8c20b6 | 549 | list_for_each_entry(net, net_exit_list, exit_list) |
a9b3cd7f | 550 | RCU_INIT_POINTER(net->nfnl, NULL); |
cd8c20b6 AD |
551 | synchronize_net(); |
552 | list_for_each_entry(net, net_exit_list, exit_list) | |
553 | netlink_kernel_release(net->nfnl_stash); | |
554 | } | |
f9e815b3 | 555 | |
cd8c20b6 AD |
556 | static struct pernet_operations nfnetlink_net_ops = { |
557 | .init = nfnetlink_net_init, | |
558 | .exit_batch = nfnetlink_net_exit_batch, | |
559 | }; | |
560 | ||
561 | static int __init nfnetlink_init(void) | |
562 | { | |
c14b78e7 PNA |
563 | int i; |
564 | ||
97840cb6 PNA |
565 | for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) |
566 | BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); | |
567 | ||
c14b78e7 PNA |
568 | for (i=0; i<NFNL_SUBSYS_COUNT; i++) |
569 | mutex_init(&table[i].mutex); | |
570 | ||
654d0fbd | 571 | pr_info("Netfilter messages via NETLINK v%s.\n", nfversion); |
cd8c20b6 | 572 | return register_pernet_subsys(&nfnetlink_net_ops); |
f9e815b3 HW |
573 | } |
574 | ||
cd8c20b6 AD |
575 | static void __exit nfnetlink_exit(void) |
576 | { | |
654d0fbd | 577 | pr_info("Removing netfilter NETLINK layer.\n"); |
cd8c20b6 AD |
578 | unregister_pernet_subsys(&nfnetlink_net_ops); |
579 | } | |
f9e815b3 HW |
580 | module_init(nfnetlink_init); |
581 | module_exit(nfnetlink_exit); |