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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> | |
67ca3966 | 6 | * (C) 2005,2007 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 HW |
24 | #include <linux/skbuff.h> |
25 | #include <asm/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 | |
7c8d4cb4 | 103 | static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type) |
f9e815b3 HW |
104 | { |
105 | u_int8_t subsys_id = NFNL_SUBSYS_ID(type); | |
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 PM |
113 | static inline const struct nfnl_callback * |
114 | nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss) | |
f9e815b3 HW |
115 | { |
116 | u_int8_t 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 | ||
3ab1f683 PM |
130 | struct sk_buff *nfnetlink_alloc_skb(struct net *net, unsigned int size, |
131 | u32 dst_portid, gfp_t gfp_mask) | |
132 | { | |
133 | return netlink_alloc_skb(net->nfnl, size, dst_portid, gfp_mask); | |
134 | } | |
135 | EXPORT_SYMBOL_GPL(nfnetlink_alloc_skb); | |
136 | ||
ec464e5d | 137 | int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, |
95c96174 | 138 | unsigned int group, int echo, gfp_t flags) |
f9e815b3 | 139 | { |
ec464e5d | 140 | return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags); |
f9e815b3 | 141 | } |
f4bc177f | 142 | EXPORT_SYMBOL_GPL(nfnetlink_send); |
f9e815b3 | 143 | |
ec464e5d | 144 | int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) |
dd5b6ce6 | 145 | { |
ec464e5d | 146 | return netlink_set_err(net->nfnl, portid, group, error); |
dd5b6ce6 PNA |
147 | } |
148 | EXPORT_SYMBOL_GPL(nfnetlink_set_err); | |
149 | ||
ec464e5d PM |
150 | int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid, |
151 | int flags) | |
f9e815b3 | 152 | { |
ec464e5d | 153 | return netlink_unicast(net->nfnl, skb, portid, flags); |
f9e815b3 | 154 | } |
f4bc177f | 155 | EXPORT_SYMBOL_GPL(nfnetlink_unicast); |
f9e815b3 HW |
156 | |
157 | /* Process one complete nfnetlink message. */ | |
1d00a4eb | 158 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
f9e815b3 | 159 | { |
cd8c20b6 | 160 | struct net *net = sock_net(skb->sk); |
7c8d4cb4 PM |
161 | const struct nfnl_callback *nc; |
162 | const struct nfnetlink_subsystem *ss; | |
1d00a4eb | 163 | int type, err; |
f9e815b3 | 164 | |
f9e815b3 | 165 | /* All the messages must at least contain nfgenmsg */ |
573ce260 | 166 | if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) |
f9e815b3 | 167 | return 0; |
f9e815b3 HW |
168 | |
169 | type = nlh->nlmsg_type; | |
e6a7d3c0 | 170 | replay: |
6b75e3e8 | 171 | rcu_read_lock(); |
f9e815b3 | 172 | ss = nfnetlink_get_subsys(type); |
0ab43f84 | 173 | if (!ss) { |
95a5afca | 174 | #ifdef CONFIG_MODULES |
6b75e3e8 | 175 | rcu_read_unlock(); |
37d2e7a2 | 176 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
6b75e3e8 | 177 | rcu_read_lock(); |
37d2e7a2 | 178 | ss = nfnetlink_get_subsys(type); |
0ab43f84 HW |
179 | if (!ss) |
180 | #endif | |
6b75e3e8 ED |
181 | { |
182 | rcu_read_unlock(); | |
1d00a4eb | 183 | return -EINVAL; |
6b75e3e8 | 184 | } |
0ab43f84 | 185 | } |
f9e815b3 HW |
186 | |
187 | nc = nfnetlink_find_client(type, ss); | |
6b75e3e8 ED |
188 | if (!nc) { |
189 | rcu_read_unlock(); | |
1d00a4eb | 190 | return -EINVAL; |
6b75e3e8 | 191 | } |
f9e815b3 | 192 | |
f9e815b3 | 193 | { |
573ce260 | 194 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
e3730578 | 195 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
f49c857f PNA |
196 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
197 | struct nlattr *attr = (void *)nlh + min_len; | |
198 | int attrlen = nlh->nlmsg_len - min_len; | |
c14b78e7 | 199 | __u8 subsys_id = NFNL_SUBSYS_ID(type); |
f49c857f PNA |
200 | |
201 | err = nla_parse(cda, ss->cb[cb_id].attr_count, | |
202 | attr, attrlen, ss->cb[cb_id].policy); | |
4009e188 TB |
203 | if (err < 0) { |
204 | rcu_read_unlock(); | |
f49c857f | 205 | return err; |
4009e188 | 206 | } |
601e68e1 | 207 | |
6b75e3e8 | 208 | if (nc->call_rcu) { |
7b8002a1 | 209 | err = nc->call_rcu(net, net->nfnl, skb, nlh, |
6b75e3e8 ED |
210 | (const struct nlattr **)cda); |
211 | rcu_read_unlock(); | |
212 | } else { | |
213 | rcu_read_unlock(); | |
c14b78e7 | 214 | nfnl_lock(subsys_id); |
9c55d3b5 | 215 | if (nfnl_dereference_protected(subsys_id) != ss || |
6b75e3e8 ED |
216 | nfnetlink_find_client(type, ss) != nc) |
217 | err = -EAGAIN; | |
59560a38 | 218 | else if (nc->call) |
7b8002a1 PNA |
219 | err = nc->call(net, net->nfnl, skb, nlh, |
220 | (const struct nlattr **)cda); | |
59560a38 TB |
221 | else |
222 | err = -EINVAL; | |
c14b78e7 | 223 | nfnl_unlock(subsys_id); |
6b75e3e8 | 224 | } |
e6a7d3c0 PNA |
225 | if (err == -EAGAIN) |
226 | goto replay; | |
227 | return err; | |
f9e815b3 | 228 | } |
f9e815b3 HW |
229 | } |
230 | ||
cbb8125e PNA |
231 | struct nfnl_err { |
232 | struct list_head head; | |
233 | struct nlmsghdr *nlh; | |
234 | int err; | |
235 | }; | |
236 | ||
237 | static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err) | |
238 | { | |
239 | struct nfnl_err *nfnl_err; | |
240 | ||
241 | nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); | |
242 | if (nfnl_err == NULL) | |
243 | return -ENOMEM; | |
244 | ||
245 | nfnl_err->nlh = nlh; | |
246 | nfnl_err->err = err; | |
247 | list_add_tail(&nfnl_err->head, list); | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | static void nfnl_err_del(struct nfnl_err *nfnl_err) | |
253 | { | |
254 | list_del(&nfnl_err->head); | |
255 | kfree(nfnl_err); | |
256 | } | |
257 | ||
258 | static void nfnl_err_reset(struct list_head *err_list) | |
259 | { | |
260 | struct nfnl_err *nfnl_err, *next; | |
261 | ||
262 | list_for_each_entry_safe(nfnl_err, next, err_list, head) | |
263 | nfnl_err_del(nfnl_err); | |
264 | } | |
265 | ||
266 | static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) | |
267 | { | |
268 | struct nfnl_err *nfnl_err, *next; | |
269 | ||
270 | list_for_each_entry_safe(nfnl_err, next, err_list, head) { | |
271 | netlink_ack(skb, nfnl_err->nlh, nfnl_err->err); | |
272 | nfnl_err_del(nfnl_err); | |
273 | } | |
274 | } | |
275 | ||
6742b9e3 PNA |
276 | enum { |
277 | NFNL_BATCH_FAILURE = (1 << 0), | |
278 | NFNL_BATCH_DONE = (1 << 1), | |
279 | NFNL_BATCH_REPLAY = (1 << 2), | |
280 | }; | |
281 | ||
0628b123 PNA |
282 | static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, |
283 | u_int16_t subsys_id) | |
284 | { | |
0f816232 | 285 | struct sk_buff *oskb = skb; |
0628b123 PNA |
286 | struct net *net = sock_net(skb->sk); |
287 | const struct nfnetlink_subsystem *ss; | |
288 | const struct nfnl_callback *nc; | |
cbb8125e | 289 | static LIST_HEAD(err_list); |
6742b9e3 | 290 | u32 status; |
0628b123 PNA |
291 | int err; |
292 | ||
293 | if (subsys_id >= NFNL_SUBSYS_COUNT) | |
294 | return netlink_ack(skb, nlh, -EINVAL); | |
295 | replay: | |
6742b9e3 PNA |
296 | status = 0; |
297 | ||
0f816232 DJ |
298 | skb = netlink_skb_clone(oskb, GFP_KERNEL); |
299 | if (!skb) | |
0628b123 PNA |
300 | return netlink_ack(oskb, nlh, -ENOMEM); |
301 | ||
0628b123 | 302 | nfnl_lock(subsys_id); |
9c55d3b5 | 303 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
304 | if (!ss) { |
305 | #ifdef CONFIG_MODULES | |
306 | nfnl_unlock(subsys_id); | |
307 | request_module("nfnetlink-subsys-%d", subsys_id); | |
308 | nfnl_lock(subsys_id); | |
9c55d3b5 | 309 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
310 | if (!ss) |
311 | #endif | |
312 | { | |
313 | nfnl_unlock(subsys_id); | |
ecd15dd7 | 314 | netlink_ack(skb, nlh, -EOPNOTSUPP); |
0f816232 | 315 | return kfree_skb(skb); |
0628b123 PNA |
316 | } |
317 | } | |
318 | ||
319 | if (!ss->commit || !ss->abort) { | |
320 | nfnl_unlock(subsys_id); | |
ecd15dd7 DF |
321 | netlink_ack(skb, nlh, -EOPNOTSUPP); |
322 | return kfree_skb(skb); | |
0628b123 PNA |
323 | } |
324 | ||
325 | while (skb->len >= nlmsg_total_size(0)) { | |
326 | int msglen, type; | |
327 | ||
328 | nlh = nlmsg_hdr(skb); | |
329 | err = 0; | |
330 | ||
9ea2aa8b PNA |
331 | if (nlmsg_len(nlh) < sizeof(struct nfgenmsg) || |
332 | skb->len < nlh->nlmsg_len) { | |
0628b123 PNA |
333 | err = -EINVAL; |
334 | goto ack; | |
335 | } | |
336 | ||
337 | /* Only requests are handled by the kernel */ | |
338 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { | |
339 | err = -EINVAL; | |
340 | goto ack; | |
341 | } | |
342 | ||
343 | type = nlh->nlmsg_type; | |
344 | if (type == NFNL_MSG_BATCH_BEGIN) { | |
345 | /* Malformed: Batch begin twice */ | |
cbb8125e | 346 | nfnl_err_reset(&err_list); |
6742b9e3 | 347 | status |= NFNL_BATCH_FAILURE; |
0628b123 PNA |
348 | goto done; |
349 | } else if (type == NFNL_MSG_BATCH_END) { | |
6742b9e3 | 350 | status |= NFNL_BATCH_DONE; |
0628b123 PNA |
351 | goto done; |
352 | } else if (type < NLMSG_MIN_TYPE) { | |
353 | err = -EINVAL; | |
354 | goto ack; | |
355 | } | |
356 | ||
357 | /* We only accept a batch with messages for the same | |
358 | * subsystem. | |
359 | */ | |
360 | if (NFNL_SUBSYS_ID(type) != subsys_id) { | |
361 | err = -EINVAL; | |
362 | goto ack; | |
363 | } | |
364 | ||
365 | nc = nfnetlink_find_client(type, ss); | |
366 | if (!nc) { | |
367 | err = -EINVAL; | |
368 | goto ack; | |
369 | } | |
370 | ||
371 | { | |
372 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); | |
373 | u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); | |
374 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; | |
375 | struct nlattr *attr = (void *)nlh + min_len; | |
376 | int attrlen = nlh->nlmsg_len - min_len; | |
377 | ||
378 | err = nla_parse(cda, ss->cb[cb_id].attr_count, | |
379 | attr, attrlen, ss->cb[cb_id].policy); | |
380 | if (err < 0) | |
381 | goto ack; | |
382 | ||
383 | if (nc->call_batch) { | |
633c9a84 | 384 | err = nc->call_batch(net, net->nfnl, skb, nlh, |
0628b123 PNA |
385 | (const struct nlattr **)cda); |
386 | } | |
387 | ||
388 | /* The lock was released to autoload some module, we | |
389 | * have to abort and start from scratch using the | |
390 | * original skb. | |
391 | */ | |
392 | if (err == -EAGAIN) { | |
6742b9e3 PNA |
393 | status |= NFNL_BATCH_REPLAY; |
394 | goto next; | |
0628b123 PNA |
395 | } |
396 | } | |
397 | ack: | |
398 | if (nlh->nlmsg_flags & NLM_F_ACK || err) { | |
cbb8125e PNA |
399 | /* Errors are delivered once the full batch has been |
400 | * processed, this avoids that the same error is | |
401 | * reported several times when replaying the batch. | |
402 | */ | |
403 | if (nfnl_err_add(&err_list, nlh, err) < 0) { | |
404 | /* We failed to enqueue an error, reset the | |
405 | * list of errors and send OOM to userspace | |
406 | * pointing to the batch header. | |
407 | */ | |
408 | nfnl_err_reset(&err_list); | |
409 | netlink_ack(skb, nlmsg_hdr(oskb), -ENOMEM); | |
6742b9e3 | 410 | status |= NFNL_BATCH_FAILURE; |
cbb8125e PNA |
411 | goto done; |
412 | } | |
0628b123 PNA |
413 | /* We don't stop processing the batch on errors, thus, |
414 | * userspace gets all the errors that the batch | |
415 | * triggers. | |
416 | */ | |
0628b123 | 417 | if (err) |
6742b9e3 | 418 | status |= NFNL_BATCH_FAILURE; |
0628b123 | 419 | } |
6742b9e3 | 420 | next: |
0628b123 PNA |
421 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
422 | if (msglen > skb->len) | |
423 | msglen = skb->len; | |
424 | skb_pull(skb, msglen); | |
425 | } | |
426 | done: | |
6742b9e3 PNA |
427 | if (status & NFNL_BATCH_REPLAY) { |
428 | ss->abort(oskb); | |
429 | nfnl_err_reset(&err_list); | |
430 | nfnl_unlock(subsys_id); | |
431 | kfree_skb(skb); | |
432 | goto replay; | |
433 | } else if (status == NFNL_BATCH_DONE) { | |
fc04733a | 434 | ss->commit(oskb); |
6742b9e3 | 435 | } else { |
fc04733a | 436 | ss->abort(oskb); |
6742b9e3 | 437 | } |
0628b123 | 438 | |
cbb8125e | 439 | nfnl_err_deliver(&err_list, oskb); |
0628b123 | 440 | nfnl_unlock(subsys_id); |
0f816232 | 441 | kfree_skb(skb); |
0628b123 PNA |
442 | } |
443 | ||
cd40b7d3 | 444 | static void nfnetlink_rcv(struct sk_buff *skb) |
f9e815b3 | 445 | { |
0628b123 | 446 | struct nlmsghdr *nlh = nlmsg_hdr(skb); |
a9de9777 | 447 | u_int16_t res_id; |
0628b123 PNA |
448 | int msglen; |
449 | ||
0628b123 PNA |
450 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
451 | skb->len < nlh->nlmsg_len) | |
452 | return; | |
453 | ||
90f62cf3 | 454 | if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { |
cdbe7c2d JB |
455 | netlink_ack(skb, nlh, -EPERM); |
456 | return; | |
457 | } | |
458 | ||
0628b123 PNA |
459 | if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) { |
460 | struct nfgenmsg *nfgenmsg; | |
461 | ||
462 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); | |
463 | if (msglen > skb->len) | |
464 | msglen = skb->len; | |
465 | ||
466 | if (nlh->nlmsg_len < NLMSG_HDRLEN || | |
467 | skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) | |
468 | return; | |
469 | ||
470 | nfgenmsg = nlmsg_data(nlh); | |
471 | skb_pull(skb, msglen); | |
a9de9777 PNA |
472 | /* Work around old nft using host byte order */ |
473 | if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) | |
474 | res_id = NFNL_SUBSYS_NFTABLES; | |
475 | else | |
476 | res_id = ntohs(nfgenmsg->res_id); | |
477 | nfnetlink_rcv_batch(skb, nlh, res_id); | |
0628b123 PNA |
478 | } else { |
479 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); | |
480 | } | |
f9e815b3 HW |
481 | } |
482 | ||
03292745 | 483 | #ifdef CONFIG_MODULES |
023e2cfa | 484 | static int nfnetlink_bind(struct net *net, int group) |
03292745 PNA |
485 | { |
486 | const struct nfnetlink_subsystem *ss; | |
97840cb6 PNA |
487 | int type; |
488 | ||
489 | if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) | |
62924af2 | 490 | return 0; |
97840cb6 PNA |
491 | |
492 | type = nfnl_group2type[group]; | |
03292745 PNA |
493 | |
494 | rcu_read_lock(); | |
dbc3617f | 495 | ss = nfnetlink_get_subsys(type << 8); |
03292745 | 496 | rcu_read_unlock(); |
bfe4bc71 RGB |
497 | if (!ss) |
498 | request_module("nfnetlink-subsys-%d", type); | |
4f520900 | 499 | return 0; |
03292745 PNA |
500 | } |
501 | #endif | |
502 | ||
cd8c20b6 | 503 | static int __net_init nfnetlink_net_init(struct net *net) |
f9e815b3 | 504 | { |
cd8c20b6 | 505 | struct sock *nfnl; |
a31f2d17 PNA |
506 | struct netlink_kernel_cfg cfg = { |
507 | .groups = NFNLGRP_MAX, | |
508 | .input = nfnetlink_rcv, | |
03292745 PNA |
509 | #ifdef CONFIG_MODULES |
510 | .bind = nfnetlink_bind, | |
511 | #endif | |
a31f2d17 | 512 | }; |
cd8c20b6 | 513 | |
9f00d977 | 514 | nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); |
cd8c20b6 AD |
515 | if (!nfnl) |
516 | return -ENOMEM; | |
517 | net->nfnl_stash = nfnl; | |
cf778b00 | 518 | rcu_assign_pointer(net->nfnl, nfnl); |
cd8c20b6 | 519 | return 0; |
f9e815b3 HW |
520 | } |
521 | ||
cd8c20b6 | 522 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
f9e815b3 | 523 | { |
cd8c20b6 | 524 | struct net *net; |
f9e815b3 | 525 | |
cd8c20b6 | 526 | list_for_each_entry(net, net_exit_list, exit_list) |
a9b3cd7f | 527 | RCU_INIT_POINTER(net->nfnl, NULL); |
cd8c20b6 AD |
528 | synchronize_net(); |
529 | list_for_each_entry(net, net_exit_list, exit_list) | |
530 | netlink_kernel_release(net->nfnl_stash); | |
531 | } | |
f9e815b3 | 532 | |
cd8c20b6 AD |
533 | static struct pernet_operations nfnetlink_net_ops = { |
534 | .init = nfnetlink_net_init, | |
535 | .exit_batch = nfnetlink_net_exit_batch, | |
536 | }; | |
537 | ||
538 | static int __init nfnetlink_init(void) | |
539 | { | |
c14b78e7 PNA |
540 | int i; |
541 | ||
97840cb6 PNA |
542 | for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) |
543 | BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); | |
544 | ||
c14b78e7 PNA |
545 | for (i=0; i<NFNL_SUBSYS_COUNT; i++) |
546 | mutex_init(&table[i].mutex); | |
547 | ||
654d0fbd | 548 | pr_info("Netfilter messages via NETLINK v%s.\n", nfversion); |
cd8c20b6 | 549 | return register_pernet_subsys(&nfnetlink_net_ops); |
f9e815b3 HW |
550 | } |
551 | ||
cd8c20b6 AD |
552 | static void __exit nfnetlink_exit(void) |
553 | { | |
654d0fbd | 554 | pr_info("Removing netfilter NETLINK layer.\n"); |
cd8c20b6 AD |
555 | unregister_pernet_subsys(&nfnetlink_net_ops); |
556 | } | |
f9e815b3 HW |
557 | module_init(nfnetlink_init); |
558 | module_exit(nfnetlink_exit); |