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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. */ | |
2d4bc933 JB |
151 | static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, |
152 | struct netlink_ext_ack *extack) | |
f9e815b3 | 153 | { |
cd8c20b6 | 154 | struct net *net = sock_net(skb->sk); |
7c8d4cb4 PM |
155 | const struct nfnl_callback *nc; |
156 | const struct nfnetlink_subsystem *ss; | |
1d00a4eb | 157 | int type, err; |
f9e815b3 | 158 | |
f9e815b3 | 159 | /* All the messages must at least contain nfgenmsg */ |
573ce260 | 160 | if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) |
f9e815b3 | 161 | return 0; |
f9e815b3 HW |
162 | |
163 | type = nlh->nlmsg_type; | |
e6a7d3c0 | 164 | replay: |
6b75e3e8 | 165 | rcu_read_lock(); |
f9e815b3 | 166 | ss = nfnetlink_get_subsys(type); |
0ab43f84 | 167 | if (!ss) { |
95a5afca | 168 | #ifdef CONFIG_MODULES |
6b75e3e8 | 169 | rcu_read_unlock(); |
37d2e7a2 | 170 | request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); |
6b75e3e8 | 171 | rcu_read_lock(); |
37d2e7a2 | 172 | ss = nfnetlink_get_subsys(type); |
0ab43f84 HW |
173 | if (!ss) |
174 | #endif | |
6b75e3e8 ED |
175 | { |
176 | rcu_read_unlock(); | |
1d00a4eb | 177 | return -EINVAL; |
6b75e3e8 | 178 | } |
0ab43f84 | 179 | } |
f9e815b3 HW |
180 | |
181 | nc = nfnetlink_find_client(type, ss); | |
6b75e3e8 ED |
182 | if (!nc) { |
183 | rcu_read_unlock(); | |
1d00a4eb | 184 | return -EINVAL; |
6b75e3e8 | 185 | } |
f9e815b3 | 186 | |
f9e815b3 | 187 | { |
573ce260 | 188 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
b745d035 | 189 | u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
f49c857f PNA |
190 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
191 | struct nlattr *attr = (void *)nlh + min_len; | |
192 | int attrlen = nlh->nlmsg_len - min_len; | |
c14b78e7 | 193 | __u8 subsys_id = NFNL_SUBSYS_ID(type); |
f49c857f | 194 | |
fceb6435 JB |
195 | err = nla_parse(cda, ss->cb[cb_id].attr_count, attr, attrlen, |
196 | ss->cb[cb_id].policy, NULL); | |
4009e188 TB |
197 | if (err < 0) { |
198 | rcu_read_unlock(); | |
f49c857f | 199 | return err; |
4009e188 | 200 | } |
601e68e1 | 201 | |
6b75e3e8 | 202 | if (nc->call_rcu) { |
7b8002a1 | 203 | err = nc->call_rcu(net, net->nfnl, skb, nlh, |
6b75e3e8 ED |
204 | (const struct nlattr **)cda); |
205 | rcu_read_unlock(); | |
206 | } else { | |
207 | rcu_read_unlock(); | |
c14b78e7 | 208 | nfnl_lock(subsys_id); |
9c55d3b5 | 209 | if (nfnl_dereference_protected(subsys_id) != ss || |
6b75e3e8 ED |
210 | nfnetlink_find_client(type, ss) != nc) |
211 | err = -EAGAIN; | |
59560a38 | 212 | else if (nc->call) |
7b8002a1 PNA |
213 | err = nc->call(net, net->nfnl, skb, nlh, |
214 | (const struct nlattr **)cda); | |
59560a38 TB |
215 | else |
216 | err = -EINVAL; | |
c14b78e7 | 217 | nfnl_unlock(subsys_id); |
6b75e3e8 | 218 | } |
e6a7d3c0 PNA |
219 | if (err == -EAGAIN) |
220 | goto replay; | |
221 | return err; | |
f9e815b3 | 222 | } |
f9e815b3 HW |
223 | } |
224 | ||
cbb8125e PNA |
225 | struct nfnl_err { |
226 | struct list_head head; | |
227 | struct nlmsghdr *nlh; | |
228 | int err; | |
229 | }; | |
230 | ||
231 | static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err) | |
232 | { | |
233 | struct nfnl_err *nfnl_err; | |
234 | ||
235 | nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); | |
236 | if (nfnl_err == NULL) | |
237 | return -ENOMEM; | |
238 | ||
239 | nfnl_err->nlh = nlh; | |
240 | nfnl_err->err = err; | |
241 | list_add_tail(&nfnl_err->head, list); | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | static void nfnl_err_del(struct nfnl_err *nfnl_err) | |
247 | { | |
248 | list_del(&nfnl_err->head); | |
249 | kfree(nfnl_err); | |
250 | } | |
251 | ||
252 | static void nfnl_err_reset(struct list_head *err_list) | |
253 | { | |
254 | struct nfnl_err *nfnl_err, *next; | |
255 | ||
256 | list_for_each_entry_safe(nfnl_err, next, err_list, head) | |
257 | nfnl_err_del(nfnl_err); | |
258 | } | |
259 | ||
260 | static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) | |
261 | { | |
262 | struct nfnl_err *nfnl_err, *next; | |
263 | ||
264 | list_for_each_entry_safe(nfnl_err, next, err_list, head) { | |
2d4bc933 | 265 | netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, NULL); |
cbb8125e PNA |
266 | nfnl_err_del(nfnl_err); |
267 | } | |
268 | } | |
269 | ||
6742b9e3 PNA |
270 | enum { |
271 | NFNL_BATCH_FAILURE = (1 << 0), | |
272 | NFNL_BATCH_DONE = (1 << 1), | |
273 | NFNL_BATCH_REPLAY = (1 << 2), | |
274 | }; | |
275 | ||
0628b123 | 276 | static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, |
8c4d4e8b | 277 | u16 subsys_id, u32 genid) |
0628b123 | 278 | { |
0f816232 | 279 | struct sk_buff *oskb = skb; |
0628b123 PNA |
280 | struct net *net = sock_net(skb->sk); |
281 | const struct nfnetlink_subsystem *ss; | |
282 | const struct nfnl_callback *nc; | |
4eba8b78 | 283 | LIST_HEAD(err_list); |
6742b9e3 | 284 | u32 status; |
0628b123 PNA |
285 | int err; |
286 | ||
287 | if (subsys_id >= NFNL_SUBSYS_COUNT) | |
2d4bc933 | 288 | return netlink_ack(skb, nlh, -EINVAL, NULL); |
0628b123 | 289 | replay: |
6742b9e3 PNA |
290 | status = 0; |
291 | ||
0f816232 DJ |
292 | skb = netlink_skb_clone(oskb, GFP_KERNEL); |
293 | if (!skb) | |
2d4bc933 | 294 | return netlink_ack(oskb, nlh, -ENOMEM, NULL); |
0628b123 | 295 | |
0628b123 | 296 | nfnl_lock(subsys_id); |
9c55d3b5 | 297 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
298 | if (!ss) { |
299 | #ifdef CONFIG_MODULES | |
300 | nfnl_unlock(subsys_id); | |
301 | request_module("nfnetlink-subsys-%d", subsys_id); | |
302 | nfnl_lock(subsys_id); | |
9c55d3b5 | 303 | ss = nfnl_dereference_protected(subsys_id); |
0628b123 PNA |
304 | if (!ss) |
305 | #endif | |
306 | { | |
307 | nfnl_unlock(subsys_id); | |
2d4bc933 | 308 | netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); |
0f816232 | 309 | return kfree_skb(skb); |
0628b123 PNA |
310 | } |
311 | } | |
312 | ||
313 | if (!ss->commit || !ss->abort) { | |
314 | nfnl_unlock(subsys_id); | |
2d4bc933 | 315 | netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); |
ecd15dd7 | 316 | return kfree_skb(skb); |
0628b123 PNA |
317 | } |
318 | ||
8c4d4e8b PNA |
319 | if (genid && ss->valid_genid && !ss->valid_genid(net, genid)) { |
320 | nfnl_unlock(subsys_id); | |
2d4bc933 | 321 | netlink_ack(oskb, nlh, -ERESTART, NULL); |
8c4d4e8b PNA |
322 | return kfree_skb(skb); |
323 | } | |
324 | ||
0628b123 PNA |
325 | while (skb->len >= nlmsg_total_size(0)) { |
326 | int msglen, type; | |
327 | ||
328 | nlh = nlmsg_hdr(skb); | |
329 | err = 0; | |
330 | ||
c58d6c93 PT |
331 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
332 | skb->len < nlh->nlmsg_len || | |
333 | nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { | |
334 | nfnl_err_reset(&err_list); | |
335 | status |= NFNL_BATCH_FAILURE; | |
336 | goto done; | |
0628b123 PNA |
337 | } |
338 | ||
339 | /* Only requests are handled by the kernel */ | |
340 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { | |
341 | err = -EINVAL; | |
342 | goto ack; | |
343 | } | |
344 | ||
345 | type = nlh->nlmsg_type; | |
346 | if (type == NFNL_MSG_BATCH_BEGIN) { | |
347 | /* Malformed: Batch begin twice */ | |
cbb8125e | 348 | nfnl_err_reset(&err_list); |
6742b9e3 | 349 | status |= NFNL_BATCH_FAILURE; |
0628b123 PNA |
350 | goto done; |
351 | } else if (type == NFNL_MSG_BATCH_END) { | |
6742b9e3 | 352 | status |= NFNL_BATCH_DONE; |
0628b123 PNA |
353 | goto done; |
354 | } else if (type < NLMSG_MIN_TYPE) { | |
355 | err = -EINVAL; | |
356 | goto ack; | |
357 | } | |
358 | ||
359 | /* We only accept a batch with messages for the same | |
360 | * subsystem. | |
361 | */ | |
362 | if (NFNL_SUBSYS_ID(type) != subsys_id) { | |
363 | err = -EINVAL; | |
364 | goto ack; | |
365 | } | |
366 | ||
367 | nc = nfnetlink_find_client(type, ss); | |
368 | if (!nc) { | |
369 | err = -EINVAL; | |
370 | goto ack; | |
371 | } | |
372 | ||
373 | { | |
374 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); | |
b745d035 | 375 | u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); |
0628b123 PNA |
376 | struct nlattr *cda[ss->cb[cb_id].attr_count + 1]; |
377 | struct nlattr *attr = (void *)nlh + min_len; | |
378 | int attrlen = nlh->nlmsg_len - min_len; | |
379 | ||
fceb6435 JB |
380 | err = nla_parse(cda, ss->cb[cb_id].attr_count, attr, |
381 | attrlen, ss->cb[cb_id].policy, NULL); | |
0628b123 PNA |
382 | if (err < 0) |
383 | goto ack; | |
384 | ||
385 | if (nc->call_batch) { | |
633c9a84 | 386 | err = nc->call_batch(net, net->nfnl, skb, nlh, |
0628b123 PNA |
387 | (const struct nlattr **)cda); |
388 | } | |
389 | ||
390 | /* The lock was released to autoload some module, we | |
391 | * have to abort and start from scratch using the | |
392 | * original skb. | |
393 | */ | |
394 | if (err == -EAGAIN) { | |
6742b9e3 PNA |
395 | status |= NFNL_BATCH_REPLAY; |
396 | goto next; | |
0628b123 PNA |
397 | } |
398 | } | |
399 | ack: | |
400 | if (nlh->nlmsg_flags & NLM_F_ACK || err) { | |
cbb8125e PNA |
401 | /* Errors are delivered once the full batch has been |
402 | * processed, this avoids that the same error is | |
403 | * reported several times when replaying the batch. | |
404 | */ | |
405 | if (nfnl_err_add(&err_list, nlh, err) < 0) { | |
406 | /* We failed to enqueue an error, reset the | |
407 | * list of errors and send OOM to userspace | |
408 | * pointing to the batch header. | |
409 | */ | |
410 | nfnl_err_reset(&err_list); | |
2d4bc933 JB |
411 | netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM, |
412 | NULL); | |
6742b9e3 | 413 | status |= NFNL_BATCH_FAILURE; |
cbb8125e PNA |
414 | goto done; |
415 | } | |
0628b123 PNA |
416 | /* We don't stop processing the batch on errors, thus, |
417 | * userspace gets all the errors that the batch | |
418 | * triggers. | |
419 | */ | |
0628b123 | 420 | if (err) |
6742b9e3 | 421 | status |= NFNL_BATCH_FAILURE; |
0628b123 | 422 | } |
6742b9e3 | 423 | next: |
0628b123 PNA |
424 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
425 | if (msglen > skb->len) | |
426 | msglen = skb->len; | |
427 | skb_pull(skb, msglen); | |
428 | } | |
429 | done: | |
6742b9e3 | 430 | if (status & NFNL_BATCH_REPLAY) { |
5913beaf | 431 | ss->abort(net, oskb); |
6742b9e3 PNA |
432 | nfnl_err_reset(&err_list); |
433 | nfnl_unlock(subsys_id); | |
434 | kfree_skb(skb); | |
435 | goto replay; | |
436 | } else if (status == NFNL_BATCH_DONE) { | |
5913beaf | 437 | ss->commit(net, oskb); |
6742b9e3 | 438 | } else { |
5913beaf | 439 | ss->abort(net, oskb); |
6742b9e3 | 440 | } |
0628b123 | 441 | |
cbb8125e | 442 | nfnl_err_deliver(&err_list, oskb); |
0628b123 | 443 | nfnl_unlock(subsys_id); |
0f816232 | 444 | kfree_skb(skb); |
0628b123 PNA |
445 | } |
446 | ||
8c4d4e8b PNA |
447 | static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = { |
448 | [NFNL_BATCH_GENID] = { .type = NLA_U32 }, | |
449 | }; | |
450 | ||
48656835 | 451 | static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh) |
f9e815b3 | 452 | { |
8c4d4e8b PNA |
453 | int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); |
454 | struct nlattr *attr = (void *)nlh + min_len; | |
455 | struct nlattr *cda[NFNL_BATCH_MAX + 1]; | |
456 | int attrlen = nlh->nlmsg_len - min_len; | |
48656835 | 457 | struct nfgenmsg *nfgenmsg; |
8c4d4e8b PNA |
458 | int msglen, err; |
459 | u32 gen_id = 0; | |
b745d035 | 460 | u16 res_id; |
0628b123 | 461 | |
48656835 PNA |
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 | ||
fceb6435 JB |
470 | err = nla_parse(cda, NFNL_BATCH_MAX, attr, attrlen, nfnl_batch_policy, |
471 | NULL); | |
8c4d4e8b | 472 | if (err < 0) { |
2d4bc933 | 473 | netlink_ack(skb, nlh, err, NULL); |
8c4d4e8b PNA |
474 | return; |
475 | } | |
476 | if (cda[NFNL_BATCH_GENID]) | |
477 | gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID])); | |
478 | ||
48656835 PNA |
479 | nfgenmsg = nlmsg_data(nlh); |
480 | skb_pull(skb, msglen); | |
481 | /* Work around old nft using host byte order */ | |
482 | if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) | |
483 | res_id = NFNL_SUBSYS_NFTABLES; | |
484 | else | |
485 | res_id = ntohs(nfgenmsg->res_id); | |
486 | ||
8c4d4e8b | 487 | nfnetlink_rcv_batch(skb, nlh, res_id, gen_id); |
48656835 PNA |
488 | } |
489 | ||
490 | static void nfnetlink_rcv(struct sk_buff *skb) | |
491 | { | |
492 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
493 | ||
0628b123 PNA |
494 | if (nlh->nlmsg_len < NLMSG_HDRLEN || |
495 | skb->len < nlh->nlmsg_len) | |
496 | return; | |
497 | ||
90f62cf3 | 498 | if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { |
2d4bc933 | 499 | netlink_ack(skb, nlh, -EPERM, NULL); |
cdbe7c2d JB |
500 | return; |
501 | } | |
502 | ||
48656835 PNA |
503 | if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) |
504 | nfnetlink_rcv_skb_batch(skb, nlh); | |
505 | else | |
0628b123 | 506 | netlink_rcv_skb(skb, &nfnetlink_rcv_msg); |
f9e815b3 HW |
507 | } |
508 | ||
03292745 | 509 | #ifdef CONFIG_MODULES |
023e2cfa | 510 | static int nfnetlink_bind(struct net *net, int group) |
03292745 PNA |
511 | { |
512 | const struct nfnetlink_subsystem *ss; | |
97840cb6 PNA |
513 | int type; |
514 | ||
515 | if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) | |
62924af2 | 516 | return 0; |
97840cb6 PNA |
517 | |
518 | type = nfnl_group2type[group]; | |
03292745 PNA |
519 | |
520 | rcu_read_lock(); | |
dbc3617f | 521 | ss = nfnetlink_get_subsys(type << 8); |
03292745 | 522 | rcu_read_unlock(); |
bfe4bc71 RGB |
523 | if (!ss) |
524 | request_module("nfnetlink-subsys-%d", type); | |
4f520900 | 525 | return 0; |
03292745 PNA |
526 | } |
527 | #endif | |
528 | ||
cd8c20b6 | 529 | static int __net_init nfnetlink_net_init(struct net *net) |
f9e815b3 | 530 | { |
cd8c20b6 | 531 | struct sock *nfnl; |
a31f2d17 PNA |
532 | struct netlink_kernel_cfg cfg = { |
533 | .groups = NFNLGRP_MAX, | |
534 | .input = nfnetlink_rcv, | |
03292745 PNA |
535 | #ifdef CONFIG_MODULES |
536 | .bind = nfnetlink_bind, | |
537 | #endif | |
a31f2d17 | 538 | }; |
cd8c20b6 | 539 | |
9f00d977 | 540 | nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); |
cd8c20b6 AD |
541 | if (!nfnl) |
542 | return -ENOMEM; | |
543 | net->nfnl_stash = nfnl; | |
cf778b00 | 544 | rcu_assign_pointer(net->nfnl, nfnl); |
cd8c20b6 | 545 | return 0; |
f9e815b3 HW |
546 | } |
547 | ||
cd8c20b6 | 548 | static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) |
f9e815b3 | 549 | { |
cd8c20b6 | 550 | struct net *net; |
f9e815b3 | 551 | |
cd8c20b6 | 552 | list_for_each_entry(net, net_exit_list, exit_list) |
a9b3cd7f | 553 | RCU_INIT_POINTER(net->nfnl, NULL); |
cd8c20b6 AD |
554 | synchronize_net(); |
555 | list_for_each_entry(net, net_exit_list, exit_list) | |
556 | netlink_kernel_release(net->nfnl_stash); | |
557 | } | |
f9e815b3 | 558 | |
cd8c20b6 AD |
559 | static struct pernet_operations nfnetlink_net_ops = { |
560 | .init = nfnetlink_net_init, | |
561 | .exit_batch = nfnetlink_net_exit_batch, | |
562 | }; | |
563 | ||
564 | static int __init nfnetlink_init(void) | |
565 | { | |
c14b78e7 PNA |
566 | int i; |
567 | ||
97840cb6 PNA |
568 | for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) |
569 | BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); | |
570 | ||
c14b78e7 PNA |
571 | for (i=0; i<NFNL_SUBSYS_COUNT; i++) |
572 | mutex_init(&table[i].mutex); | |
573 | ||
654d0fbd | 574 | pr_info("Netfilter messages via NETLINK v%s.\n", nfversion); |
cd8c20b6 | 575 | return register_pernet_subsys(&nfnetlink_net_ops); |
f9e815b3 HW |
576 | } |
577 | ||
cd8c20b6 AD |
578 | static void __exit nfnetlink_exit(void) |
579 | { | |
654d0fbd | 580 | pr_info("Removing netfilter NETLINK layer.\n"); |
cd8c20b6 AD |
581 | unregister_pernet_subsys(&nfnetlink_net_ops); |
582 | } | |
f9e815b3 HW |
583 | module_init(nfnetlink_init); |
584 | module_exit(nfnetlink_exit); |