Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
cd1df525 | 6 | * Patrick McHardy <kaber@trash.net> |
1da177e4 LT |
7 | * |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 12 | * |
1da177e4 LT |
13 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
14 | * added netlink_proto_exit | |
15 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
16 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
17 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
18 | * - inc module use count of module that owns | |
19 | * the kernel socket in case userspace opens | |
20 | * socket of same protocol | |
21 | * - remove all module support, since netlink is | |
22 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
23 | */ |
24 | ||
1da177e4 LT |
25 | #include <linux/module.h> |
26 | ||
4fc268d2 | 27 | #include <linux/capability.h> |
1da177e4 LT |
28 | #include <linux/kernel.h> |
29 | #include <linux/init.h> | |
1da177e4 LT |
30 | #include <linux/signal.h> |
31 | #include <linux/sched.h> | |
32 | #include <linux/errno.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/stat.h> | |
35 | #include <linux/socket.h> | |
36 | #include <linux/un.h> | |
37 | #include <linux/fcntl.h> | |
38 | #include <linux/termios.h> | |
39 | #include <linux/sockios.h> | |
40 | #include <linux/net.h> | |
41 | #include <linux/fs.h> | |
42 | #include <linux/slab.h> | |
7c0f6ba6 | 43 | #include <linux/uaccess.h> |
1da177e4 LT |
44 | #include <linux/skbuff.h> |
45 | #include <linux/netdevice.h> | |
46 | #include <linux/rtnetlink.h> | |
47 | #include <linux/proc_fs.h> | |
48 | #include <linux/seq_file.h> | |
1da177e4 LT |
49 | #include <linux/notifier.h> |
50 | #include <linux/security.h> | |
51 | #include <linux/jhash.h> | |
52 | #include <linux/jiffies.h> | |
53 | #include <linux/random.h> | |
54 | #include <linux/bitops.h> | |
55 | #include <linux/mm.h> | |
56 | #include <linux/types.h> | |
54e0f520 | 57 | #include <linux/audit.h> |
af65bdfc | 58 | #include <linux/mutex.h> |
ccdfcc39 | 59 | #include <linux/vmalloc.h> |
bcbde0d4 | 60 | #include <linux/if_arp.h> |
e341694e | 61 | #include <linux/rhashtable.h> |
9652e931 | 62 | #include <asm/cacheflush.h> |
e341694e | 63 | #include <linux/hash.h> |
ee1c2442 | 64 | #include <linux/genetlink.h> |
7212462f | 65 | #include <linux/net_namespace.h> |
bc5b6c0b | 66 | #include <linux/nospec.h> |
54e0f520 | 67 | |
457c4cbc | 68 | #include <net/net_namespace.h> |
25e3f70f | 69 | #include <net/netns/generic.h> |
1da177e4 LT |
70 | #include <net/sock.h> |
71 | #include <net/scm.h> | |
82ace47a | 72 | #include <net/netlink.h> |
1da177e4 | 73 | |
0f29c768 | 74 | #include "af_netlink.h" |
1da177e4 | 75 | |
5c398dc8 ED |
76 | struct listeners { |
77 | struct rcu_head rcu; | |
78 | unsigned long masks[0]; | |
6c04bb18 JB |
79 | }; |
80 | ||
cd967e05 | 81 | /* state bits */ |
cc3a572f | 82 | #define NETLINK_S_CONGESTED 0x0 |
cd967e05 | 83 | |
035c4c16 | 84 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 | 85 | { |
cc3a572f | 86 | return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; |
aed81560 DL |
87 | } |
88 | ||
91dd93f9 | 89 | struct netlink_table *nl_table __read_mostly; |
0f29c768 | 90 | EXPORT_SYMBOL_GPL(nl_table); |
1da177e4 LT |
91 | |
92 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
93 | ||
8a0f5ccf HX |
94 | static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; |
95 | ||
96 | static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { | |
97 | "nlk_cb_mutex-ROUTE", | |
98 | "nlk_cb_mutex-1", | |
99 | "nlk_cb_mutex-USERSOCK", | |
100 | "nlk_cb_mutex-FIREWALL", | |
101 | "nlk_cb_mutex-SOCK_DIAG", | |
102 | "nlk_cb_mutex-NFLOG", | |
103 | "nlk_cb_mutex-XFRM", | |
104 | "nlk_cb_mutex-SELINUX", | |
105 | "nlk_cb_mutex-ISCSI", | |
106 | "nlk_cb_mutex-AUDIT", | |
107 | "nlk_cb_mutex-FIB_LOOKUP", | |
108 | "nlk_cb_mutex-CONNECTOR", | |
109 | "nlk_cb_mutex-NETFILTER", | |
110 | "nlk_cb_mutex-IP6_FW", | |
111 | "nlk_cb_mutex-DNRTMSG", | |
112 | "nlk_cb_mutex-KOBJECT_UEVENT", | |
113 | "nlk_cb_mutex-GENERIC", | |
114 | "nlk_cb_mutex-17", | |
115 | "nlk_cb_mutex-SCSITRANSPORT", | |
116 | "nlk_cb_mutex-ECRYPTFS", | |
117 | "nlk_cb_mutex-RDMA", | |
118 | "nlk_cb_mutex-CRYPTO", | |
119 | "nlk_cb_mutex-SMC", | |
120 | "nlk_cb_mutex-23", | |
121 | "nlk_cb_mutex-24", | |
122 | "nlk_cb_mutex-25", | |
123 | "nlk_cb_mutex-26", | |
124 | "nlk_cb_mutex-27", | |
125 | "nlk_cb_mutex-28", | |
126 | "nlk_cb_mutex-29", | |
127 | "nlk_cb_mutex-30", | |
128 | "nlk_cb_mutex-31", | |
129 | "nlk_cb_mutex-MAX_LINKS" | |
130 | }; | |
131 | ||
1da177e4 | 132 | static int netlink_dump(struct sock *sk); |
1da177e4 | 133 | |
78fd1d0a | 134 | /* nl_table locking explained: |
21e4902a | 135 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
c5adde94 | 136 | * and removal are protected with per bucket lock while using RCU list |
21e4902a TG |
137 | * modification primitives and may run in parallel to RCU protected lookups. |
138 | * Destruction of the Netlink socket may only occur *after* nl_table_lock has | |
139 | * been acquired * either during or after the socket has been removed from | |
140 | * the list and after an RCU grace period. | |
78fd1d0a | 141 | */ |
0f29c768 AV |
142 | DEFINE_RWLOCK(nl_table_lock); |
143 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
144 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
145 | ||
6d772ac5 ED |
146 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
147 | ||
efa172f4 | 148 | static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 149 | |
bcbde0d4 | 150 | |
c428ecd1 HX |
151 | static const struct rhashtable_params netlink_rhashtable_params; |
152 | ||
b57ef81f | 153 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
154 | { |
155 | return group ? 1 << (group - 1) : 0; | |
156 | } | |
157 | ||
1853c949 DB |
158 | static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
159 | gfp_t gfp_mask) | |
160 | { | |
161 | unsigned int len = skb_end_offset(skb); | |
162 | struct sk_buff *new; | |
163 | ||
164 | new = alloc_skb(len, gfp_mask); | |
165 | if (new == NULL) | |
166 | return NULL; | |
167 | ||
168 | NETLINK_CB(new).portid = NETLINK_CB(skb).portid; | |
169 | NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; | |
170 | NETLINK_CB(new).creds = NETLINK_CB(skb).creds; | |
171 | ||
59ae1d12 | 172 | skb_put_data(new, skb->data, len); |
1853c949 DB |
173 | return new; |
174 | } | |
175 | ||
25e3f70f CW |
176 | static unsigned int netlink_tap_net_id; |
177 | ||
178 | struct netlink_tap_net { | |
179 | struct list_head netlink_tap_all; | |
b1042d35 | 180 | struct mutex netlink_tap_lock; |
25e3f70f CW |
181 | }; |
182 | ||
bcbde0d4 DB |
183 | int netlink_add_tap(struct netlink_tap *nt) |
184 | { | |
25e3f70f CW |
185 | struct net *net = dev_net(nt->dev); |
186 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
187 | ||
bcbde0d4 DB |
188 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) |
189 | return -EINVAL; | |
190 | ||
b1042d35 | 191 | mutex_lock(&nn->netlink_tap_lock); |
25e3f70f | 192 | list_add_rcu(&nt->list, &nn->netlink_tap_all); |
b1042d35 | 193 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 194 | |
fcd4d35e | 195 | __module_get(nt->module); |
bcbde0d4 DB |
196 | |
197 | return 0; | |
198 | } | |
199 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
200 | ||
2173f8d9 | 201 | static int __netlink_remove_tap(struct netlink_tap *nt) |
bcbde0d4 | 202 | { |
25e3f70f CW |
203 | struct net *net = dev_net(nt->dev); |
204 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
bcbde0d4 DB |
205 | bool found = false; |
206 | struct netlink_tap *tmp; | |
207 | ||
b1042d35 | 208 | mutex_lock(&nn->netlink_tap_lock); |
bcbde0d4 | 209 | |
25e3f70f | 210 | list_for_each_entry(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
211 | if (nt == tmp) { |
212 | list_del_rcu(&nt->list); | |
213 | found = true; | |
214 | goto out; | |
215 | } | |
216 | } | |
217 | ||
218 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
219 | out: | |
b1042d35 | 220 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 221 | |
92b80eb3 | 222 | if (found) |
bcbde0d4 DB |
223 | module_put(nt->module); |
224 | ||
225 | return found ? 0 : -ENODEV; | |
226 | } | |
bcbde0d4 DB |
227 | |
228 | int netlink_remove_tap(struct netlink_tap *nt) | |
229 | { | |
230 | int ret; | |
231 | ||
232 | ret = __netlink_remove_tap(nt); | |
233 | synchronize_net(); | |
234 | ||
235 | return ret; | |
236 | } | |
237 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
238 | ||
25e3f70f CW |
239 | static __net_init int netlink_tap_init_net(struct net *net) |
240 | { | |
241 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
242 | ||
243 | INIT_LIST_HEAD(&nn->netlink_tap_all); | |
b1042d35 | 244 | mutex_init(&nn->netlink_tap_lock); |
25e3f70f CW |
245 | return 0; |
246 | } | |
247 | ||
248 | static void __net_exit netlink_tap_exit_net(struct net *net) | |
249 | { | |
250 | } | |
251 | ||
252 | static struct pernet_operations netlink_tap_net_ops = { | |
253 | .init = netlink_tap_init_net, | |
254 | .exit = netlink_tap_exit_net, | |
255 | .id = &netlink_tap_net_id, | |
256 | .size = sizeof(struct netlink_tap_net), | |
257 | }; | |
258 | ||
5ffd5cdd DB |
259 | static bool netlink_filter_tap(const struct sk_buff *skb) |
260 | { | |
261 | struct sock *sk = skb->sk; | |
5ffd5cdd DB |
262 | |
263 | /* We take the more conservative approach and | |
264 | * whitelist socket protocols that may pass. | |
265 | */ | |
266 | switch (sk->sk_protocol) { | |
267 | case NETLINK_ROUTE: | |
268 | case NETLINK_USERSOCK: | |
269 | case NETLINK_SOCK_DIAG: | |
270 | case NETLINK_NFLOG: | |
271 | case NETLINK_XFRM: | |
272 | case NETLINK_FIB_LOOKUP: | |
273 | case NETLINK_NETFILTER: | |
274 | case NETLINK_GENERIC: | |
498044bb | 275 | return true; |
5ffd5cdd DB |
276 | } |
277 | ||
498044bb | 278 | return false; |
5ffd5cdd DB |
279 | } |
280 | ||
bcbde0d4 DB |
281 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
282 | struct net_device *dev) | |
283 | { | |
284 | struct sk_buff *nskb; | |
5ffd5cdd | 285 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
286 | int ret = -ENOMEM; |
287 | ||
93c64764 KC |
288 | if (!net_eq(dev_net(dev), sock_net(sk))) |
289 | return 0; | |
290 | ||
bcbde0d4 | 291 | dev_hold(dev); |
1853c949 | 292 | |
d1b4c689 | 293 | if (is_vmalloc_addr(skb->head)) |
1853c949 DB |
294 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
295 | else | |
296 | nskb = skb_clone(skb, GFP_ATOMIC); | |
bcbde0d4 DB |
297 | if (nskb) { |
298 | nskb->dev = dev; | |
5ffd5cdd | 299 | nskb->protocol = htons((u16) sk->sk_protocol); |
604d13c9 DB |
300 | nskb->pkt_type = netlink_is_kernel(sk) ? |
301 | PACKET_KERNEL : PACKET_USER; | |
4e48ed88 | 302 | skb_reset_network_header(nskb); |
bcbde0d4 DB |
303 | ret = dev_queue_xmit(nskb); |
304 | if (unlikely(ret > 0)) | |
305 | ret = net_xmit_errno(ret); | |
306 | } | |
307 | ||
308 | dev_put(dev); | |
309 | return ret; | |
310 | } | |
311 | ||
25e3f70f | 312 | static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) |
bcbde0d4 DB |
313 | { |
314 | int ret; | |
315 | struct netlink_tap *tmp; | |
316 | ||
5ffd5cdd DB |
317 | if (!netlink_filter_tap(skb)) |
318 | return; | |
319 | ||
25e3f70f | 320 | list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
321 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); |
322 | if (unlikely(ret)) | |
323 | break; | |
324 | } | |
325 | } | |
326 | ||
25e3f70f | 327 | static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) |
bcbde0d4 | 328 | { |
25e3f70f CW |
329 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
330 | ||
bcbde0d4 DB |
331 | rcu_read_lock(); |
332 | ||
25e3f70f CW |
333 | if (unlikely(!list_empty(&nn->netlink_tap_all))) |
334 | __netlink_deliver_tap(skb, nn); | |
bcbde0d4 DB |
335 | |
336 | rcu_read_unlock(); | |
337 | } | |
338 | ||
73bfd370 DB |
339 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
340 | struct sk_buff *skb) | |
341 | { | |
342 | if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) | |
25e3f70f | 343 | netlink_deliver_tap(sock_net(dst), skb); |
73bfd370 DB |
344 | } |
345 | ||
cd1df525 PM |
346 | static void netlink_overrun(struct sock *sk) |
347 | { | |
348 | struct netlink_sock *nlk = nlk_sk(sk); | |
349 | ||
cc3a572f ND |
350 | if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { |
351 | if (!test_and_set_bit(NETLINK_S_CONGESTED, | |
352 | &nlk_sk(sk)->state)) { | |
cd1df525 PM |
353 | sk->sk_err = ENOBUFS; |
354 | sk->sk_error_report(sk); | |
355 | } | |
356 | } | |
357 | atomic_inc(&sk->sk_drops); | |
358 | } | |
359 | ||
360 | static void netlink_rcv_wake(struct sock *sk) | |
361 | { | |
362 | struct netlink_sock *nlk = nlk_sk(sk); | |
363 | ||
364 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
cc3a572f ND |
365 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
366 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) | |
cd1df525 PM |
367 | wake_up_interruptible(&nlk->wait); |
368 | } | |
369 | ||
cf0a018a PM |
370 | static void netlink_skb_destructor(struct sk_buff *skb) |
371 | { | |
c05cdb1b | 372 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
373 | if (!skb->cloned || |
374 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
375 | vfree(skb->head); | |
376 | ||
c05cdb1b PNA |
377 | skb->head = NULL; |
378 | } | |
9652e931 PM |
379 | if (skb->sk != NULL) |
380 | sock_rfree(skb); | |
cf0a018a PM |
381 | } |
382 | ||
383 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
384 | { | |
385 | WARN_ON(skb->sk != NULL); | |
386 | skb->sk = sk; | |
387 | skb->destructor = netlink_skb_destructor; | |
388 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
389 | sk_mem_charge(sk, skb->truesize); | |
390 | } | |
391 | ||
ed5d7788 | 392 | static void netlink_sock_destruct(struct sock *sk) |
1da177e4 | 393 | { |
3f660d66 HX |
394 | struct netlink_sock *nlk = nlk_sk(sk); |
395 | ||
16b304f3 | 396 | if (nlk->cb_running) { |
ed5d7788 HX |
397 | if (nlk->cb.done) |
398 | nlk->cb.done(&nlk->cb); | |
16b304f3 PS |
399 | module_put(nlk->cb.module); |
400 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
401 | } |
402 | ||
1da177e4 LT |
403 | skb_queue_purge(&sk->sk_receive_queue); |
404 | ||
405 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 406 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
407 | return; |
408 | } | |
547b792c IJ |
409 | |
410 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
14afee4b | 411 | WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
547b792c | 412 | WARN_ON(nlk_sk(sk)->groups); |
1da177e4 LT |
413 | } |
414 | ||
707693c8 HX |
415 | static void netlink_sock_destruct_work(struct work_struct *work) |
416 | { | |
417 | struct netlink_sock *nlk = container_of(work, struct netlink_sock, | |
418 | work); | |
419 | ||
ed5d7788 | 420 | sk_free(&nlk->sk); |
707693c8 HX |
421 | } |
422 | ||
6ac552fd PM |
423 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
424 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
425 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
426 | * this, _but_ remember, it adds useless work on UP machines. | |
427 | */ | |
428 | ||
d136f1bd | 429 | void netlink_table_grab(void) |
9a429c49 | 430 | __acquires(nl_table_lock) |
1da177e4 | 431 | { |
d136f1bd JB |
432 | might_sleep(); |
433 | ||
6abd219c | 434 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
435 | |
436 | if (atomic_read(&nl_table_users)) { | |
437 | DECLARE_WAITQUEUE(wait, current); | |
438 | ||
439 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 440 | for (;;) { |
1da177e4 LT |
441 | set_current_state(TASK_UNINTERRUPTIBLE); |
442 | if (atomic_read(&nl_table_users) == 0) | |
443 | break; | |
6abd219c | 444 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 445 | schedule(); |
6abd219c | 446 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
447 | } |
448 | ||
449 | __set_current_state(TASK_RUNNING); | |
450 | remove_wait_queue(&nl_table_wait, &wait); | |
451 | } | |
452 | } | |
453 | ||
d136f1bd | 454 | void netlink_table_ungrab(void) |
9a429c49 | 455 | __releases(nl_table_lock) |
1da177e4 | 456 | { |
6abd219c | 457 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
458 | wake_up(&nl_table_wait); |
459 | } | |
460 | ||
6ac552fd | 461 | static inline void |
1da177e4 LT |
462 | netlink_lock_table(void) |
463 | { | |
464 | /* read_lock() synchronizes us to netlink_table_grab */ | |
465 | ||
466 | read_lock(&nl_table_lock); | |
467 | atomic_inc(&nl_table_users); | |
468 | read_unlock(&nl_table_lock); | |
469 | } | |
470 | ||
6ac552fd | 471 | static inline void |
1da177e4 LT |
472 | netlink_unlock_table(void) |
473 | { | |
474 | if (atomic_dec_and_test(&nl_table_users)) | |
475 | wake_up(&nl_table_wait); | |
476 | } | |
477 | ||
e341694e | 478 | struct netlink_compare_arg |
1da177e4 | 479 | { |
c428ecd1 | 480 | possible_net_t pnet; |
e341694e TG |
481 | u32 portid; |
482 | }; | |
1da177e4 | 483 | |
8f2ddaac HX |
484 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
485 | #define netlink_compare_arg_len \ | |
486 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
487 | |
488 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
489 | const void *ptr) | |
1da177e4 | 490 | { |
c428ecd1 HX |
491 | const struct netlink_compare_arg *x = arg->key; |
492 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 493 | |
da314c99 | 494 | return nlk->portid != x->portid || |
c428ecd1 HX |
495 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
496 | } | |
497 | ||
498 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
499 | struct net *net, u32 portid) | |
500 | { | |
501 | memset(arg, 0, sizeof(*arg)); | |
502 | write_pnet(&arg->pnet, net); | |
503 | arg->portid = portid; | |
1da177e4 LT |
504 | } |
505 | ||
e341694e TG |
506 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
507 | struct net *net) | |
1da177e4 | 508 | { |
c428ecd1 | 509 | struct netlink_compare_arg arg; |
1da177e4 | 510 | |
c428ecd1 HX |
511 | netlink_compare_arg_init(&arg, net, portid); |
512 | return rhashtable_lookup_fast(&table->hash, &arg, | |
513 | netlink_rhashtable_params); | |
1da177e4 LT |
514 | } |
515 | ||
c428ecd1 | 516 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 517 | { |
c428ecd1 | 518 | struct netlink_compare_arg arg; |
c5adde94 | 519 | |
da314c99 | 520 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
521 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
522 | &nlk_sk(sk)->node, | |
523 | netlink_rhashtable_params); | |
c5adde94 YX |
524 | } |
525 | ||
e341694e | 526 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 527 | { |
e341694e TG |
528 | struct netlink_table *table = &nl_table[protocol]; |
529 | struct sock *sk; | |
1da177e4 | 530 | |
e341694e TG |
531 | rcu_read_lock(); |
532 | sk = __netlink_lookup(table, portid, net); | |
533 | if (sk) | |
534 | sock_hold(sk); | |
535 | rcu_read_unlock(); | |
1da177e4 | 536 | |
e341694e | 537 | return sk; |
1da177e4 LT |
538 | } |
539 | ||
90ddc4f0 | 540 | static const struct proto_ops netlink_ops; |
1da177e4 | 541 | |
4277a083 PM |
542 | static void |
543 | netlink_update_listeners(struct sock *sk) | |
544 | { | |
545 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
546 | unsigned long mask; |
547 | unsigned int i; | |
6d772ac5 ED |
548 | struct listeners *listeners; |
549 | ||
550 | listeners = nl_deref_protected(tbl->listeners); | |
551 | if (!listeners) | |
552 | return; | |
4277a083 | 553 | |
b4ff4f04 | 554 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 555 | mask = 0; |
b67bfe0d | 556 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
557 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
558 | mask |= nlk_sk(sk)->groups[i]; | |
559 | } | |
6d772ac5 | 560 | listeners->masks[i] = mask; |
4277a083 PM |
561 | } |
562 | /* this function is only called with the netlink table "grabbed", which | |
563 | * makes sure updates are visible before bind or setsockopt return. */ | |
564 | } | |
565 | ||
8ea65f4a | 566 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 567 | { |
da12c90e | 568 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 569 | int err; |
1da177e4 | 570 | |
c5adde94 | 571 | lock_sock(sk); |
1da177e4 | 572 | |
da314c99 HX |
573 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
574 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
575 | goto err; |
576 | ||
da314c99 | 577 | nlk_sk(sk)->portid = portid; |
e341694e | 578 | sock_hold(sk); |
919d9db9 | 579 | |
c428ecd1 HX |
580 | err = __netlink_insert(table, sk); |
581 | if (err) { | |
4e7c1330 DB |
582 | /* In case the hashtable backend returns with -EBUSY |
583 | * from here, it must not escape to the caller. | |
584 | */ | |
585 | if (unlikely(err == -EBUSY)) | |
586 | err = -EOVERFLOW; | |
c428ecd1 HX |
587 | if (err == -EEXIST) |
588 | err = -EADDRINUSE; | |
c5adde94 | 589 | sock_put(sk); |
1f770c0a | 590 | goto err; |
919d9db9 HX |
591 | } |
592 | ||
da314c99 HX |
593 | /* We need to ensure that the socket is hashed and visible. */ |
594 | smp_wmb(); | |
595 | nlk_sk(sk)->bound = portid; | |
1f770c0a | 596 | |
1da177e4 | 597 | err: |
c5adde94 | 598 | release_sock(sk); |
1da177e4 LT |
599 | return err; |
600 | } | |
601 | ||
602 | static void netlink_remove(struct sock *sk) | |
603 | { | |
e341694e TG |
604 | struct netlink_table *table; |
605 | ||
e341694e | 606 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
607 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
608 | netlink_rhashtable_params)) { | |
41c6d650 | 609 | WARN_ON(refcount_read(&sk->sk_refcnt) == 1); |
e341694e TG |
610 | __sock_put(sk); |
611 | } | |
e341694e | 612 | |
1da177e4 | 613 | netlink_table_grab(); |
b10dcb3b | 614 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 615 | __sk_del_bind_node(sk); |
b10dcb3b JB |
616 | netlink_update_listeners(sk); |
617 | } | |
ee1c2442 JB |
618 | if (sk->sk_protocol == NETLINK_GENERIC) |
619 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
620 | netlink_table_ungrab(); |
621 | } | |
622 | ||
623 | static struct proto netlink_proto = { | |
624 | .name = "NETLINK", | |
625 | .owner = THIS_MODULE, | |
626 | .obj_size = sizeof(struct netlink_sock), | |
627 | }; | |
628 | ||
1b8d7ae4 | 629 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
630 | struct mutex *cb_mutex, int protocol, |
631 | int kern) | |
1da177e4 LT |
632 | { |
633 | struct sock *sk; | |
634 | struct netlink_sock *nlk; | |
ab33a171 PM |
635 | |
636 | sock->ops = &netlink_ops; | |
637 | ||
11aa9c28 | 638 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
639 | if (!sk) |
640 | return -ENOMEM; | |
641 | ||
642 | sock_init_data(sock, sk); | |
643 | ||
644 | nlk = nlk_sk(sk); | |
658cb354 | 645 | if (cb_mutex) { |
ffa4d721 | 646 | nlk->cb_mutex = cb_mutex; |
658cb354 | 647 | } else { |
ffa4d721 PM |
648 | nlk->cb_mutex = &nlk->cb_def_mutex; |
649 | mutex_init(nlk->cb_mutex); | |
8a0f5ccf HX |
650 | lockdep_set_class_and_name(nlk->cb_mutex, |
651 | nlk_cb_mutex_keys + protocol, | |
652 | nlk_cb_mutex_key_strings[protocol]); | |
ffa4d721 | 653 | } |
ab33a171 PM |
654 | init_waitqueue_head(&nlk->wait); |
655 | ||
656 | sk->sk_destruct = netlink_sock_destruct; | |
657 | sk->sk_protocol = protocol; | |
658 | return 0; | |
659 | } | |
660 | ||
3f378b68 EP |
661 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
662 | int kern) | |
ab33a171 PM |
663 | { |
664 | struct module *module = NULL; | |
af65bdfc | 665 | struct mutex *cb_mutex; |
f7fa9b10 | 666 | struct netlink_sock *nlk; |
023e2cfa JB |
667 | int (*bind)(struct net *net, int group); |
668 | void (*unbind)(struct net *net, int group); | |
ab33a171 | 669 | int err = 0; |
1da177e4 LT |
670 | |
671 | sock->state = SS_UNCONNECTED; | |
672 | ||
673 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
674 | return -ESOCKTNOSUPPORT; | |
675 | ||
6ac552fd | 676 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 | 677 | return -EPROTONOSUPPORT; |
bc5b6c0b | 678 | protocol = array_index_nospec(protocol, MAX_LINKS); |
1da177e4 | 679 | |
77247bbb | 680 | netlink_lock_table(); |
95a5afca | 681 | #ifdef CONFIG_MODULES |
ab33a171 | 682 | if (!nl_table[protocol].registered) { |
77247bbb | 683 | netlink_unlock_table(); |
4fdb3bb7 | 684 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 685 | netlink_lock_table(); |
4fdb3bb7 | 686 | } |
ab33a171 PM |
687 | #endif |
688 | if (nl_table[protocol].registered && | |
689 | try_module_get(nl_table[protocol].module)) | |
690 | module = nl_table[protocol].module; | |
974c37e9 AD |
691 | else |
692 | err = -EPROTONOSUPPORT; | |
af65bdfc | 693 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 694 | bind = nl_table[protocol].bind; |
4f520900 | 695 | unbind = nl_table[protocol].unbind; |
77247bbb | 696 | netlink_unlock_table(); |
4fdb3bb7 | 697 | |
974c37e9 AD |
698 | if (err < 0) |
699 | goto out; | |
700 | ||
11aa9c28 | 701 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 702 | if (err < 0) |
f7fa9b10 PM |
703 | goto out_module; |
704 | ||
6f756a8c | 705 | local_bh_disable(); |
c1fd3b94 | 706 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
707 | local_bh_enable(); |
708 | ||
f7fa9b10 | 709 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 710 | nlk->module = module; |
03292745 | 711 | nlk->netlink_bind = bind; |
4f520900 | 712 | nlk->netlink_unbind = unbind; |
ab33a171 PM |
713 | out: |
714 | return err; | |
1da177e4 | 715 | |
ab33a171 PM |
716 | out_module: |
717 | module_put(module); | |
718 | goto out; | |
1da177e4 LT |
719 | } |
720 | ||
21e4902a TG |
721 | static void deferred_put_nlk_sk(struct rcu_head *head) |
722 | { | |
723 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
ed5d7788 HX |
724 | struct sock *sk = &nlk->sk; |
725 | ||
be82485f XL |
726 | kfree(nlk->groups); |
727 | nlk->groups = NULL; | |
728 | ||
41c6d650 | 729 | if (!refcount_dec_and_test(&sk->sk_refcnt)) |
ed5d7788 HX |
730 | return; |
731 | ||
732 | if (nlk->cb_running && nlk->cb.done) { | |
733 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); | |
734 | schedule_work(&nlk->work); | |
735 | return; | |
736 | } | |
21e4902a | 737 | |
ed5d7788 | 738 | sk_free(sk); |
21e4902a TG |
739 | } |
740 | ||
1da177e4 LT |
741 | static int netlink_release(struct socket *sock) |
742 | { | |
743 | struct sock *sk = sock->sk; | |
744 | struct netlink_sock *nlk; | |
745 | ||
746 | if (!sk) | |
747 | return 0; | |
748 | ||
749 | netlink_remove(sk); | |
ac57b3a9 | 750 | sock_orphan(sk); |
1da177e4 LT |
751 | nlk = nlk_sk(sk); |
752 | ||
3f660d66 HX |
753 | /* |
754 | * OK. Socket is unlinked, any packets that arrive now | |
755 | * will be purged. | |
756 | */ | |
1da177e4 | 757 | |
ee1c2442 JB |
758 | /* must not acquire netlink_table_lock in any way again before unbind |
759 | * and notifying genetlink is done as otherwise it might deadlock | |
760 | */ | |
761 | if (nlk->netlink_unbind) { | |
762 | int i; | |
763 | ||
764 | for (i = 0; i < nlk->ngroups; i++) | |
765 | if (test_bit(i, nlk->groups)) | |
766 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
767 | } | |
768 | if (sk->sk_protocol == NETLINK_GENERIC && | |
769 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
770 | wake_up(&genl_sk_destructing_waitq); | |
771 | ||
1da177e4 LT |
772 | sock->sk = NULL; |
773 | wake_up_interruptible_all(&nlk->wait); | |
774 | ||
775 | skb_queue_purge(&sk->sk_write_queue); | |
776 | ||
e2726020 | 777 | if (nlk->portid && nlk->bound) { |
1da177e4 | 778 | struct netlink_notify n = { |
3b1e0a65 | 779 | .net = sock_net(sk), |
1da177e4 | 780 | .protocol = sk->sk_protocol, |
15e47304 | 781 | .portid = nlk->portid, |
1da177e4 | 782 | }; |
efa172f4 | 783 | blocking_notifier_call_chain(&netlink_chain, |
e041c683 | 784 | NETLINK_URELEASE, &n); |
746fac4d | 785 | } |
4fdb3bb7 | 786 | |
5e7c001c | 787 | module_put(nlk->module); |
4fdb3bb7 | 788 | |
aed81560 | 789 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 790 | netlink_table_grab(); |
869e58f8 DL |
791 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
792 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
793 | struct listeners *old; |
794 | ||
795 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
796 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
797 | kfree_rcu(old, rcu); | |
869e58f8 | 798 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 799 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 800 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 801 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
802 | nl_table[sk->sk_protocol].registered = 0; |
803 | } | |
b10dcb3b | 804 | netlink_table_ungrab(); |
658cb354 | 805 | } |
77247bbb | 806 | |
3755810c | 807 | local_bh_disable(); |
c1fd3b94 | 808 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 809 | local_bh_enable(); |
21e4902a | 810 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
811 | return 0; |
812 | } | |
813 | ||
814 | static int netlink_autobind(struct socket *sock) | |
815 | { | |
816 | struct sock *sk = sock->sk; | |
3b1e0a65 | 817 | struct net *net = sock_net(sk); |
da12c90e | 818 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 819 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 820 | int err; |
b9fbe709 HX |
821 | s32 rover = -4096; |
822 | bool ok; | |
1da177e4 LT |
823 | |
824 | retry: | |
825 | cond_resched(); | |
e341694e | 826 | rcu_read_lock(); |
b9fbe709 HX |
827 | ok = !__netlink_lookup(table, portid, net); |
828 | rcu_read_unlock(); | |
829 | if (!ok) { | |
e341694e | 830 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
831 | if (rover == -4096) |
832 | /* rover will be in range [S32_MIN, -4097] */ | |
833 | rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); | |
834 | else if (rover >= -4096) | |
e341694e | 835 | rover = -4097; |
b9fbe709 | 836 | portid = rover--; |
e341694e | 837 | goto retry; |
1da177e4 | 838 | } |
1da177e4 | 839 | |
8ea65f4a | 840 | err = netlink_insert(sk, portid); |
1da177e4 LT |
841 | if (err == -EADDRINUSE) |
842 | goto retry; | |
d470e3b4 DM |
843 | |
844 | /* If 2 threads race to autobind, that is fine. */ | |
845 | if (err == -EBUSY) | |
846 | err = 0; | |
847 | ||
848 | return err; | |
1da177e4 LT |
849 | } |
850 | ||
aa4cf945 EB |
851 | /** |
852 | * __netlink_ns_capable - General netlink message capability test | |
853 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. | |
854 | * @user_ns: The user namespace of the capability to use | |
855 | * @cap: The capability to use | |
856 | * | |
857 | * Test to see if the opener of the socket we received the message | |
858 | * from had when the netlink socket was created and the sender of the | |
859 | * message has has the capability @cap in the user namespace @user_ns. | |
860 | */ | |
861 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, | |
862 | struct user_namespace *user_ns, int cap) | |
863 | { | |
2d7a85f4 EB |
864 | return ((nsp->flags & NETLINK_SKB_DST) || |
865 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
866 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
867 | } |
868 | EXPORT_SYMBOL(__netlink_ns_capable); | |
869 | ||
870 | /** | |
871 | * netlink_ns_capable - General netlink message capability test | |
872 | * @skb: socket buffer holding a netlink command from userspace | |
873 | * @user_ns: The user namespace of the capability to use | |
874 | * @cap: The capability to use | |
875 | * | |
876 | * Test to see if the opener of the socket we received the message | |
877 | * from had when the netlink socket was created and the sender of the | |
878 | * message has has the capability @cap in the user namespace @user_ns. | |
879 | */ | |
880 | bool netlink_ns_capable(const struct sk_buff *skb, | |
881 | struct user_namespace *user_ns, int cap) | |
882 | { | |
883 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
884 | } | |
885 | EXPORT_SYMBOL(netlink_ns_capable); | |
886 | ||
887 | /** | |
888 | * netlink_capable - Netlink global message capability test | |
889 | * @skb: socket buffer holding a netlink command from userspace | |
890 | * @cap: The capability to use | |
891 | * | |
892 | * Test to see if the opener of the socket we received the message | |
893 | * from had when the netlink socket was created and the sender of the | |
894 | * message has has the capability @cap in all user namespaces. | |
895 | */ | |
896 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
897 | { | |
898 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
899 | } | |
900 | EXPORT_SYMBOL(netlink_capable); | |
901 | ||
902 | /** | |
903 | * netlink_net_capable - Netlink network namespace message capability test | |
904 | * @skb: socket buffer holding a netlink command from userspace | |
905 | * @cap: The capability to use | |
906 | * | |
907 | * Test to see if the opener of the socket we received the message | |
908 | * from had when the netlink socket was created and the sender of the | |
909 | * message has has the capability @cap over the network namespace of | |
910 | * the socket we received the message from. | |
911 | */ | |
912 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
913 | { | |
914 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
915 | } | |
916 | EXPORT_SYMBOL(netlink_net_capable); | |
917 | ||
5187cd05 | 918 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 919 | { |
9785e10a | 920 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 921 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 922 | } |
1da177e4 | 923 | |
f7fa9b10 PM |
924 | static void |
925 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
926 | { | |
927 | struct netlink_sock *nlk = nlk_sk(sk); | |
928 | ||
929 | if (nlk->subscriptions && !subscriptions) | |
930 | __sk_del_bind_node(sk); | |
931 | else if (!nlk->subscriptions && subscriptions) | |
932 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
933 | nlk->subscriptions = subscriptions; | |
934 | } | |
935 | ||
b4ff4f04 | 936 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
937 | { |
938 | struct netlink_sock *nlk = nlk_sk(sk); | |
939 | unsigned int groups; | |
b4ff4f04 | 940 | unsigned long *new_groups; |
513c2500 PM |
941 | int err = 0; |
942 | ||
b4ff4f04 JB |
943 | netlink_table_grab(); |
944 | ||
513c2500 | 945 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 946 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 947 | err = -ENOENT; |
b4ff4f04 JB |
948 | goto out_unlock; |
949 | } | |
513c2500 | 950 | |
b4ff4f04 JB |
951 | if (nlk->ngroups >= groups) |
952 | goto out_unlock; | |
513c2500 | 953 | |
b4ff4f04 JB |
954 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
955 | if (new_groups == NULL) { | |
956 | err = -ENOMEM; | |
957 | goto out_unlock; | |
958 | } | |
6ac552fd | 959 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
960 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
961 | ||
962 | nlk->groups = new_groups; | |
513c2500 | 963 | nlk->ngroups = groups; |
b4ff4f04 JB |
964 | out_unlock: |
965 | netlink_table_ungrab(); | |
966 | return err; | |
513c2500 PM |
967 | } |
968 | ||
02c81ab9 | 969 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 970 | struct sock *sk) |
4f520900 | 971 | { |
023e2cfa | 972 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
973 | int undo; |
974 | ||
975 | if (!nlk->netlink_unbind) | |
976 | return; | |
977 | ||
978 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 979 | if (test_bit(undo, &groups)) |
8b7c36d8 | 980 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
981 | } |
982 | ||
6ac552fd PM |
983 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
984 | int addr_len) | |
1da177e4 LT |
985 | { |
986 | struct sock *sk = sock->sk; | |
3b1e0a65 | 987 | struct net *net = sock_net(sk); |
1da177e4 LT |
988 | struct netlink_sock *nlk = nlk_sk(sk); |
989 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
f7736080 | 990 | int err = 0; |
428f944b | 991 | unsigned long groups = nladdr->nl_groups; |
da314c99 | 992 | bool bound; |
746fac4d | 993 | |
4e4b5376 HFS |
994 | if (addr_len < sizeof(struct sockaddr_nl)) |
995 | return -EINVAL; | |
996 | ||
1da177e4 LT |
997 | if (nladdr->nl_family != AF_NETLINK) |
998 | return -EINVAL; | |
999 | ||
1000 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 1001 | if (groups) { |
5187cd05 | 1002 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 1003 | return -EPERM; |
b4ff4f04 JB |
1004 | err = netlink_realloc_groups(sk); |
1005 | if (err) | |
1006 | return err; | |
513c2500 | 1007 | } |
1da177e4 | 1008 | |
428f944b | 1009 | if (nlk->ngroups < BITS_PER_LONG) |
91874ecf | 1010 | groups &= (1UL << nlk->ngroups) - 1; |
1da177e4 | 1011 | |
da314c99 HX |
1012 | bound = nlk->bound; |
1013 | if (bound) { | |
1014 | /* Ensure nlk->portid is up-to-date. */ | |
1015 | smp_rmb(); | |
1016 | ||
15e47304 | 1017 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 1018 | return -EINVAL; |
da314c99 | 1019 | } |
4f520900 | 1020 | |
f7736080 | 1021 | netlink_lock_table(); |
4f520900 RGB |
1022 | if (nlk->netlink_bind && groups) { |
1023 | int group; | |
1024 | ||
1025 | for (group = 0; group < nlk->ngroups; group++) { | |
1026 | if (!test_bit(group, &groups)) | |
1027 | continue; | |
8b7c36d8 | 1028 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
1029 | if (!err) |
1030 | continue; | |
023e2cfa | 1031 | netlink_undo_bind(group, groups, sk); |
f7736080 | 1032 | goto unlock; |
4f520900 RGB |
1033 | } |
1034 | } | |
1035 | ||
da314c99 HX |
1036 | /* No need for barriers here as we return to user-space without |
1037 | * using any of the bound attributes. | |
1038 | */ | |
1039 | if (!bound) { | |
1da177e4 | 1040 | err = nladdr->nl_pid ? |
8ea65f4a | 1041 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 1042 | netlink_autobind(sock); |
4f520900 | 1043 | if (err) { |
023e2cfa | 1044 | netlink_undo_bind(nlk->ngroups, groups, sk); |
f7736080 | 1045 | goto unlock; |
4f520900 | 1046 | } |
1da177e4 LT |
1047 | } |
1048 | ||
4f520900 | 1049 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
f7736080 XL |
1050 | goto unlock; |
1051 | netlink_unlock_table(); | |
1da177e4 LT |
1052 | |
1053 | netlink_table_grab(); | |
f7fa9b10 | 1054 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 1055 | hweight32(groups) - |
746fac4d | 1056 | hweight32(nlk->groups[0])); |
4f520900 | 1057 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 1058 | netlink_update_listeners(sk); |
1da177e4 LT |
1059 | netlink_table_ungrab(); |
1060 | ||
1061 | return 0; | |
f7736080 XL |
1062 | |
1063 | unlock: | |
1064 | netlink_unlock_table(); | |
1065 | return err; | |
1da177e4 LT |
1066 | } |
1067 | ||
1068 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
1069 | int alen, int flags) | |
1070 | { | |
1071 | int err = 0; | |
1072 | struct sock *sk = sock->sk; | |
1073 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1074 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1075 | |
6503d961 CG |
1076 | if (alen < sizeof(addr->sa_family)) |
1077 | return -EINVAL; | |
1078 | ||
1da177e4 LT |
1079 | if (addr->sa_family == AF_UNSPEC) { |
1080 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 1081 | nlk->dst_portid = 0; |
d629b836 | 1082 | nlk->dst_group = 0; |
1da177e4 LT |
1083 | return 0; |
1084 | } | |
1085 | if (addr->sa_family != AF_NETLINK) | |
1086 | return -EINVAL; | |
1087 | ||
78802879 AP |
1088 | if (alen < sizeof(struct sockaddr_nl)) |
1089 | return -EINVAL; | |
1090 | ||
46833a86 | 1091 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 1092 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1093 | return -EPERM; |
1094 | ||
da314c99 HX |
1095 | /* No need for barriers here as we return to user-space without |
1096 | * using any of the bound attributes. | |
1097 | */ | |
1098 | if (!nlk->bound) | |
1da177e4 LT |
1099 | err = netlink_autobind(sock); |
1100 | ||
1101 | if (err == 0) { | |
1102 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1103 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1104 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1105 | } |
1106 | ||
1107 | return err; | |
1108 | } | |
1109 | ||
6ac552fd | 1110 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
9b2c45d4 | 1111 | int peer) |
1da177e4 LT |
1112 | { |
1113 | struct sock *sk = sock->sk; | |
1114 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1115 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1116 | |
1da177e4 LT |
1117 | nladdr->nl_family = AF_NETLINK; |
1118 | nladdr->nl_pad = 0; | |
1da177e4 LT |
1119 | |
1120 | if (peer) { | |
15e47304 | 1121 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1122 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1123 | } else { |
15e47304 | 1124 | nladdr->nl_pid = nlk->portid; |
f7736080 | 1125 | netlink_lock_table(); |
513c2500 | 1126 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
f7736080 | 1127 | netlink_unlock_table(); |
1da177e4 | 1128 | } |
9b2c45d4 | 1129 | return sizeof(*nladdr); |
1da177e4 LT |
1130 | } |
1131 | ||
025c6818 DD |
1132 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1133 | unsigned long arg) | |
1134 | { | |
1135 | /* try to hand this ioctl down to the NIC drivers. | |
1136 | */ | |
1137 | return -ENOIOCTLCMD; | |
1138 | } | |
1139 | ||
15e47304 | 1140 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1141 | { |
1da177e4 LT |
1142 | struct sock *sock; |
1143 | struct netlink_sock *nlk; | |
1144 | ||
15e47304 | 1145 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1146 | if (!sock) |
1147 | return ERR_PTR(-ECONNREFUSED); | |
1148 | ||
1149 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1150 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1151 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1152 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1153 | sock_put(sock); |
1154 | return ERR_PTR(-ECONNREFUSED); | |
1155 | } | |
1156 | return sock; | |
1157 | } | |
1158 | ||
1159 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1160 | { | |
496ad9aa | 1161 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1162 | struct sock *sock; |
1163 | ||
1164 | if (!S_ISSOCK(inode->i_mode)) | |
1165 | return ERR_PTR(-ENOTSOCK); | |
1166 | ||
1167 | sock = SOCKET_I(inode)->sk; | |
1168 | if (sock->sk_family != AF_NETLINK) | |
1169 | return ERR_PTR(-EINVAL); | |
1170 | ||
1171 | sock_hold(sock); | |
1172 | return sock; | |
1173 | } | |
1174 | ||
3a36515f PN |
1175 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1176 | int broadcast) | |
c05cdb1b PNA |
1177 | { |
1178 | struct sk_buff *skb; | |
1179 | void *data; | |
1180 | ||
3a36515f | 1181 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1182 | return alloc_skb(size, GFP_KERNEL); |
1183 | ||
3a36515f PN |
1184 | size = SKB_DATA_ALIGN(size) + |
1185 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1186 | |
1187 | data = vmalloc(size); | |
1188 | if (data == NULL) | |
3a36515f | 1189 | return NULL; |
c05cdb1b | 1190 | |
2ea2f62c | 1191 | skb = __build_skb(data, size); |
3a36515f PN |
1192 | if (skb == NULL) |
1193 | vfree(data); | |
2ea2f62c | 1194 | else |
3a36515f | 1195 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1196 | |
1197 | return skb; | |
c05cdb1b PNA |
1198 | } |
1199 | ||
1da177e4 LT |
1200 | /* |
1201 | * Attach a skb to a netlink socket. | |
1202 | * The caller must hold a reference to the destination socket. On error, the | |
1203 | * reference is dropped. The skb is not send to the destination, just all | |
1204 | * all error checks are performed and memory in the queue is reserved. | |
1205 | * Return values: | |
1206 | * < 0: error. skb freed, reference to sock dropped. | |
1207 | * 0: continue | |
1208 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1209 | */ | |
9457afee | 1210 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1211 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1212 | { |
1213 | struct netlink_sock *nlk; | |
1214 | ||
1215 | nlk = nlk_sk(sk); | |
1216 | ||
5fd96123 | 1217 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1218 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1219 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1220 | if (!*timeo) { |
aed81560 | 1221 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1222 | netlink_overrun(sk); |
1223 | sock_put(sk); | |
1224 | kfree_skb(skb); | |
1225 | return -EAGAIN; | |
1226 | } | |
1227 | ||
1228 | __set_current_state(TASK_INTERRUPTIBLE); | |
1229 | add_wait_queue(&nlk->wait, &wait); | |
1230 | ||
1231 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1232 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1233 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1234 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1235 | |
1236 | __set_current_state(TASK_RUNNING); | |
1237 | remove_wait_queue(&nlk->wait, &wait); | |
1238 | sock_put(sk); | |
1239 | ||
1240 | if (signal_pending(current)) { | |
1241 | kfree_skb(skb); | |
c3d8d1e3 | 1242 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1243 | } |
1244 | return 1; | |
1245 | } | |
cf0a018a | 1246 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1247 | return 0; |
1248 | } | |
1249 | ||
4a7e7c2a | 1250 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1251 | { |
1da177e4 LT |
1252 | int len = skb->len; |
1253 | ||
25e3f70f | 1254 | netlink_deliver_tap(sock_net(sk), skb); |
bcbde0d4 | 1255 | |
d1b4c689 | 1256 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1257 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1258 | return len; |
1259 | } | |
1260 | ||
1261 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1262 | { | |
1263 | int len = __netlink_sendskb(sk, skb); | |
1264 | ||
1da177e4 LT |
1265 | sock_put(sk); |
1266 | return len; | |
1267 | } | |
1268 | ||
1269 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1270 | { | |
1271 | kfree_skb(skb); | |
1272 | sock_put(sk); | |
1273 | } | |
1274 | ||
b57ef81f | 1275 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1276 | { |
1277 | int delta; | |
1278 | ||
1298ca46 | 1279 | WARN_ON(skb->sk != NULL); |
4305b541 | 1280 | delta = skb->end - skb->tail; |
c05cdb1b | 1281 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1282 | return skb; |
1283 | ||
1284 | if (skb_shared(skb)) { | |
1285 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1286 | if (!nskb) | |
1287 | return skb; | |
8460c00f | 1288 | consume_skb(skb); |
1da177e4 LT |
1289 | skb = nskb; |
1290 | } | |
1291 | ||
158f323b ED |
1292 | pskb_expand_head(skb, 0, -delta, |
1293 | (allocation & ~__GFP_DIRECT_RECLAIM) | | |
1294 | __GFP_NOWARN | __GFP_NORETRY); | |
1da177e4 LT |
1295 | return skb; |
1296 | } | |
1297 | ||
3fbc2905 EB |
1298 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1299 | struct sock *ssk) | |
cd40b7d3 DL |
1300 | { |
1301 | int ret; | |
1302 | struct netlink_sock *nlk = nlk_sk(sk); | |
1303 | ||
1304 | ret = -ECONNREFUSED; | |
1305 | if (nlk->netlink_rcv != NULL) { | |
1306 | ret = skb->len; | |
cf0a018a | 1307 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1308 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1309 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1310 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1311 | consume_skb(skb); |
1312 | } else { | |
1313 | kfree_skb(skb); | |
cd40b7d3 | 1314 | } |
cd40b7d3 DL |
1315 | sock_put(sk); |
1316 | return ret; | |
1317 | } | |
1318 | ||
1319 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1320 | u32 portid, int nonblock) |
1da177e4 LT |
1321 | { |
1322 | struct sock *sk; | |
1323 | int err; | |
1324 | long timeo; | |
1325 | ||
1326 | skb = netlink_trim(skb, gfp_any()); | |
1327 | ||
1328 | timeo = sock_sndtimeo(ssk, nonblock); | |
1329 | retry: | |
15e47304 | 1330 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1331 | if (IS_ERR(sk)) { |
1332 | kfree_skb(skb); | |
1333 | return PTR_ERR(sk); | |
1334 | } | |
cd40b7d3 | 1335 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1336 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1337 | |
b1153f29 | 1338 | if (sk_filter(sk, skb)) { |
84874607 | 1339 | err = skb->len; |
b1153f29 SH |
1340 | kfree_skb(skb); |
1341 | sock_put(sk); | |
1342 | return err; | |
1343 | } | |
1344 | ||
9457afee | 1345 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1346 | if (err == 1) |
1347 | goto retry; | |
1348 | if (err) | |
1349 | return err; | |
1350 | ||
7ee015e0 | 1351 | return netlink_sendskb(sk, skb); |
1da177e4 | 1352 | } |
6ac552fd | 1353 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1354 | |
4277a083 PM |
1355 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1356 | { | |
1357 | int res = 0; | |
5c398dc8 | 1358 | struct listeners *listeners; |
4277a083 | 1359 | |
aed81560 | 1360 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1361 | |
1362 | rcu_read_lock(); | |
1363 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1364 | ||
6d772ac5 | 1365 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1366 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1367 | |
1368 | rcu_read_unlock(); | |
1369 | ||
4277a083 PM |
1370 | return res; |
1371 | } | |
1372 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1373 | ||
59c28058 JK |
1374 | bool netlink_strict_get_check(struct sk_buff *skb) |
1375 | { | |
1376 | const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk); | |
1377 | ||
1378 | return nlk->flags & NETLINK_F_STRICT_CHK; | |
1379 | } | |
1380 | EXPORT_SYMBOL_GPL(netlink_strict_get_check); | |
1381 | ||
b57ef81f | 1382 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1383 | { |
1384 | struct netlink_sock *nlk = nlk_sk(sk); | |
1385 | ||
1386 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1387 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1388 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1389 | __netlink_sendskb(sk, skb); |
2c645800 | 1390 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1391 | } |
1392 | return -1; | |
1393 | } | |
1394 | ||
1395 | struct netlink_broadcast_data { | |
1396 | struct sock *exclude_sk; | |
b4b51029 | 1397 | struct net *net; |
15e47304 | 1398 | u32 portid; |
1da177e4 LT |
1399 | u32 group; |
1400 | int failure; | |
ff491a73 | 1401 | int delivery_failure; |
1da177e4 LT |
1402 | int congested; |
1403 | int delivered; | |
7d877f3b | 1404 | gfp_t allocation; |
1da177e4 | 1405 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1406 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1407 | void *tx_data; | |
1da177e4 LT |
1408 | }; |
1409 | ||
46c9521f RR |
1410 | static void do_one_broadcast(struct sock *sk, |
1411 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1412 | { |
1413 | struct netlink_sock *nlk = nlk_sk(sk); | |
1414 | int val; | |
1415 | ||
1416 | if (p->exclude_sk == sk) | |
46c9521f | 1417 | return; |
1da177e4 | 1418 | |
15e47304 | 1419 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1420 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1421 | return; |
1da177e4 | 1422 | |
59324cf3 ND |
1423 | if (!net_eq(sock_net(sk), p->net)) { |
1424 | if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) | |
1425 | return; | |
1426 | ||
1427 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1428 | return; | |
1429 | ||
1430 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1431 | CAP_NET_BROADCAST)) | |
1432 | return; | |
1433 | } | |
b4b51029 | 1434 | |
1da177e4 LT |
1435 | if (p->failure) { |
1436 | netlink_overrun(sk); | |
46c9521f | 1437 | return; |
1da177e4 LT |
1438 | } |
1439 | ||
1440 | sock_hold(sk); | |
1441 | if (p->skb2 == NULL) { | |
68acc024 | 1442 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1443 | p->skb2 = skb_clone(p->skb, p->allocation); |
1444 | } else { | |
68acc024 TC |
1445 | p->skb2 = skb_get(p->skb); |
1446 | /* | |
1447 | * skb ownership may have been set when | |
1448 | * delivered to a previous socket. | |
1449 | */ | |
1450 | skb_orphan(p->skb2); | |
1da177e4 LT |
1451 | } |
1452 | } | |
1453 | if (p->skb2 == NULL) { | |
1454 | netlink_overrun(sk); | |
1455 | /* Clone failed. Notify ALL listeners. */ | |
1456 | p->failure = 1; | |
cc3a572f | 1457 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1458 | p->delivery_failure = 1; |
59324cf3 ND |
1459 | goto out; |
1460 | } | |
1461 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
910a7e90 EB |
1462 | kfree_skb(p->skb2); |
1463 | p->skb2 = NULL; | |
59324cf3 ND |
1464 | goto out; |
1465 | } | |
1466 | if (sk_filter(sk, p->skb2)) { | |
b1153f29 SH |
1467 | kfree_skb(p->skb2); |
1468 | p->skb2 = NULL; | |
59324cf3 ND |
1469 | goto out; |
1470 | } | |
1471 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
7212462f ND |
1472 | if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) |
1473 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
59324cf3 ND |
1474 | val = netlink_broadcast_deliver(sk, p->skb2); |
1475 | if (val < 0) { | |
1da177e4 | 1476 | netlink_overrun(sk); |
cc3a572f | 1477 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1478 | p->delivery_failure = 1; |
1da177e4 LT |
1479 | } else { |
1480 | p->congested |= val; | |
1481 | p->delivered = 1; | |
1482 | p->skb2 = NULL; | |
1483 | } | |
59324cf3 | 1484 | out: |
1da177e4 | 1485 | sock_put(sk); |
1da177e4 LT |
1486 | } |
1487 | ||
15e47304 | 1488 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1489 | u32 group, gfp_t allocation, |
1490 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1491 | void *filter_data) | |
1da177e4 | 1492 | { |
3b1e0a65 | 1493 | struct net *net = sock_net(ssk); |
1da177e4 | 1494 | struct netlink_broadcast_data info; |
1da177e4 LT |
1495 | struct sock *sk; |
1496 | ||
1497 | skb = netlink_trim(skb, allocation); | |
1498 | ||
1499 | info.exclude_sk = ssk; | |
b4b51029 | 1500 | info.net = net; |
15e47304 | 1501 | info.portid = portid; |
1da177e4 LT |
1502 | info.group = group; |
1503 | info.failure = 0; | |
ff491a73 | 1504 | info.delivery_failure = 0; |
1da177e4 LT |
1505 | info.congested = 0; |
1506 | info.delivered = 0; | |
1507 | info.allocation = allocation; | |
1508 | info.skb = skb; | |
1509 | info.skb2 = NULL; | |
910a7e90 EB |
1510 | info.tx_filter = filter; |
1511 | info.tx_data = filter_data; | |
1da177e4 LT |
1512 | |
1513 | /* While we sleep in clone, do not allow to change socket list */ | |
1514 | ||
1515 | netlink_lock_table(); | |
1516 | ||
b67bfe0d | 1517 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1518 | do_one_broadcast(sk, &info); |
1519 | ||
70d4bf6d | 1520 | consume_skb(skb); |
aa1c6a6f | 1521 | |
1da177e4 LT |
1522 | netlink_unlock_table(); |
1523 | ||
70d4bf6d NH |
1524 | if (info.delivery_failure) { |
1525 | kfree_skb(info.skb2); | |
ff491a73 | 1526 | return -ENOBUFS; |
658cb354 ED |
1527 | } |
1528 | consume_skb(info.skb2); | |
ff491a73 | 1529 | |
1da177e4 | 1530 | if (info.delivered) { |
d0164adc | 1531 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1532 | yield(); |
1533 | return 0; | |
1534 | } | |
1da177e4 LT |
1535 | return -ESRCH; |
1536 | } | |
910a7e90 EB |
1537 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1538 | ||
15e47304 | 1539 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1540 | u32 group, gfp_t allocation) |
1541 | { | |
15e47304 | 1542 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1543 | NULL, NULL); |
1544 | } | |
6ac552fd | 1545 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1546 | |
1547 | struct netlink_set_err_data { | |
1548 | struct sock *exclude_sk; | |
15e47304 | 1549 | u32 portid; |
1da177e4 LT |
1550 | u32 group; |
1551 | int code; | |
1552 | }; | |
1553 | ||
b57ef81f | 1554 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1555 | { |
1556 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1557 | int ret = 0; |
1da177e4 LT |
1558 | |
1559 | if (sk == p->exclude_sk) | |
1560 | goto out; | |
1561 | ||
09ad9bc7 | 1562 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1563 | goto out; |
1564 | ||
15e47304 | 1565 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1566 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1567 | goto out; |
1568 | ||
cc3a572f | 1569 | if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
1a50307b PNA |
1570 | ret = 1; |
1571 | goto out; | |
1572 | } | |
1573 | ||
1da177e4 LT |
1574 | sk->sk_err = p->code; |
1575 | sk->sk_error_report(sk); | |
1576 | out: | |
1a50307b | 1577 | return ret; |
1da177e4 LT |
1578 | } |
1579 | ||
4843b93c PNA |
1580 | /** |
1581 | * netlink_set_err - report error to broadcast listeners | |
1582 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1583 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1584 | * @group: the broadcast group that will notice the error |
4843b93c | 1585 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1586 | * |
1587 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1588 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1589 | */ |
15e47304 | 1590 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1591 | { |
1592 | struct netlink_set_err_data info; | |
1da177e4 | 1593 | struct sock *sk; |
1a50307b | 1594 | int ret = 0; |
1da177e4 LT |
1595 | |
1596 | info.exclude_sk = ssk; | |
15e47304 | 1597 | info.portid = portid; |
1da177e4 | 1598 | info.group = group; |
4843b93c PNA |
1599 | /* sk->sk_err wants a positive error value */ |
1600 | info.code = -code; | |
1da177e4 LT |
1601 | |
1602 | read_lock(&nl_table_lock); | |
1603 | ||
b67bfe0d | 1604 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1605 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1606 | |
1607 | read_unlock(&nl_table_lock); | |
1a50307b | 1608 | return ret; |
1da177e4 | 1609 | } |
dd5b6ce6 | 1610 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1611 | |
84659eb5 JB |
1612 | /* must be called with netlink table grabbed */ |
1613 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1614 | unsigned int group, | |
1615 | int is_new) | |
1616 | { | |
1617 | int old, new = !!is_new, subscriptions; | |
1618 | ||
1619 | old = test_bit(group - 1, nlk->groups); | |
1620 | subscriptions = nlk->subscriptions - old + new; | |
1621 | if (new) | |
1622 | __set_bit(group - 1, nlk->groups); | |
1623 | else | |
1624 | __clear_bit(group - 1, nlk->groups); | |
1625 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1626 | netlink_update_listeners(&nlk->sk); | |
1627 | } | |
1628 | ||
9a4595bc | 1629 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1630 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1631 | { |
1632 | struct sock *sk = sock->sk; | |
1633 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1634 | unsigned int val = 0; |
1635 | int err; | |
9a4595bc PM |
1636 | |
1637 | if (level != SOL_NETLINK) | |
1638 | return -ENOPROTOOPT; | |
1639 | ||
d1b4c689 | 1640 | if (optlen >= sizeof(int) && |
eb496534 | 1641 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1642 | return -EFAULT; |
1643 | ||
1644 | switch (optname) { | |
1645 | case NETLINK_PKTINFO: | |
1646 | if (val) | |
cc3a572f | 1647 | nlk->flags |= NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1648 | else |
cc3a572f | 1649 | nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1650 | err = 0; |
1651 | break; | |
1652 | case NETLINK_ADD_MEMBERSHIP: | |
1653 | case NETLINK_DROP_MEMBERSHIP: { | |
5187cd05 | 1654 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1655 | return -EPERM; |
b4ff4f04 JB |
1656 | err = netlink_realloc_groups(sk); |
1657 | if (err) | |
1658 | return err; | |
9a4595bc PM |
1659 | if (!val || val - 1 >= nlk->ngroups) |
1660 | return -EINVAL; | |
7774d5e0 | 1661 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1662 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1663 | if (err) |
1664 | return err; | |
1665 | } | |
9a4595bc | 1666 | netlink_table_grab(); |
84659eb5 JB |
1667 | netlink_update_socket_mc(nlk, val, |
1668 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1669 | netlink_table_ungrab(); |
7774d5e0 | 1670 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1671 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1672 | |
9a4595bc PM |
1673 | err = 0; |
1674 | break; | |
1675 | } | |
be0c22a4 PNA |
1676 | case NETLINK_BROADCAST_ERROR: |
1677 | if (val) | |
cc3a572f | 1678 | nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1679 | else |
cc3a572f | 1680 | nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 PNA |
1681 | err = 0; |
1682 | break; | |
38938bfe PNA |
1683 | case NETLINK_NO_ENOBUFS: |
1684 | if (val) { | |
cc3a572f ND |
1685 | nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
1686 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); | |
38938bfe | 1687 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1688 | } else { |
cc3a572f | 1689 | nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
658cb354 | 1690 | } |
38938bfe PNA |
1691 | err = 0; |
1692 | break; | |
59324cf3 ND |
1693 | case NETLINK_LISTEN_ALL_NSID: |
1694 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1695 | return -EPERM; | |
1696 | ||
1697 | if (val) | |
1698 | nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; | |
1699 | else | |
1700 | nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; | |
1701 | err = 0; | |
1702 | break; | |
0a6a3a23 CR |
1703 | case NETLINK_CAP_ACK: |
1704 | if (val) | |
1705 | nlk->flags |= NETLINK_F_CAP_ACK; | |
1706 | else | |
1707 | nlk->flags &= ~NETLINK_F_CAP_ACK; | |
1708 | err = 0; | |
1709 | break; | |
2d4bc933 JB |
1710 | case NETLINK_EXT_ACK: |
1711 | if (val) | |
1712 | nlk->flags |= NETLINK_F_EXT_ACK; | |
1713 | else | |
1714 | nlk->flags &= ~NETLINK_F_EXT_ACK; | |
1715 | err = 0; | |
1716 | break; | |
d3e8869e | 1717 | case NETLINK_GET_STRICT_CHK: |
89d35528 DA |
1718 | if (val) |
1719 | nlk->flags |= NETLINK_F_STRICT_CHK; | |
1720 | else | |
1721 | nlk->flags &= ~NETLINK_F_STRICT_CHK; | |
1722 | err = 0; | |
1723 | break; | |
9a4595bc PM |
1724 | default: |
1725 | err = -ENOPROTOOPT; | |
1726 | } | |
1727 | return err; | |
1728 | } | |
1729 | ||
1730 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1731 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1732 | { |
1733 | struct sock *sk = sock->sk; | |
1734 | struct netlink_sock *nlk = nlk_sk(sk); | |
1735 | int len, val, err; | |
1736 | ||
1737 | if (level != SOL_NETLINK) | |
1738 | return -ENOPROTOOPT; | |
1739 | ||
1740 | if (get_user(len, optlen)) | |
1741 | return -EFAULT; | |
1742 | if (len < 0) | |
1743 | return -EINVAL; | |
1744 | ||
1745 | switch (optname) { | |
1746 | case NETLINK_PKTINFO: | |
1747 | if (len < sizeof(int)) | |
1748 | return -EINVAL; | |
1749 | len = sizeof(int); | |
cc3a572f | 1750 | val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
a27b58fe HC |
1751 | if (put_user(len, optlen) || |
1752 | put_user(val, optval)) | |
1753 | return -EFAULT; | |
9a4595bc PM |
1754 | err = 0; |
1755 | break; | |
be0c22a4 PNA |
1756 | case NETLINK_BROADCAST_ERROR: |
1757 | if (len < sizeof(int)) | |
1758 | return -EINVAL; | |
1759 | len = sizeof(int); | |
cc3a572f | 1760 | val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
be0c22a4 PNA |
1761 | if (put_user(len, optlen) || |
1762 | put_user(val, optval)) | |
1763 | return -EFAULT; | |
1764 | err = 0; | |
1765 | break; | |
38938bfe PNA |
1766 | case NETLINK_NO_ENOBUFS: |
1767 | if (len < sizeof(int)) | |
1768 | return -EINVAL; | |
1769 | len = sizeof(int); | |
cc3a572f | 1770 | val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
38938bfe PNA |
1771 | if (put_user(len, optlen) || |
1772 | put_user(val, optval)) | |
1773 | return -EFAULT; | |
1774 | err = 0; | |
1775 | break; | |
b42be38b DH |
1776 | case NETLINK_LIST_MEMBERSHIPS: { |
1777 | int pos, idx, shift; | |
1778 | ||
1779 | err = 0; | |
47191d65 | 1780 | netlink_lock_table(); |
b42be38b DH |
1781 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1782 | if (len - pos < sizeof(u32)) | |
1783 | break; | |
1784 | ||
1785 | idx = pos / sizeof(unsigned long); | |
1786 | shift = (pos % sizeof(unsigned long)) * 8; | |
1787 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1788 | (u32 __user *)(optval + pos))) { | |
1789 | err = -EFAULT; | |
1790 | break; | |
1791 | } | |
1792 | } | |
1793 | if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) | |
1794 | err = -EFAULT; | |
47191d65 | 1795 | netlink_unlock_table(); |
b42be38b DH |
1796 | break; |
1797 | } | |
0a6a3a23 CR |
1798 | case NETLINK_CAP_ACK: |
1799 | if (len < sizeof(int)) | |
1800 | return -EINVAL; | |
1801 | len = sizeof(int); | |
1802 | val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; | |
1803 | if (put_user(len, optlen) || | |
1804 | put_user(val, optval)) | |
1805 | return -EFAULT; | |
1806 | err = 0; | |
1807 | break; | |
2d4bc933 JB |
1808 | case NETLINK_EXT_ACK: |
1809 | if (len < sizeof(int)) | |
1810 | return -EINVAL; | |
1811 | len = sizeof(int); | |
1812 | val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0; | |
1813 | if (put_user(len, optlen) || put_user(val, optval)) | |
1814 | return -EFAULT; | |
1815 | err = 0; | |
1816 | break; | |
d3e8869e | 1817 | case NETLINK_GET_STRICT_CHK: |
89d35528 DA |
1818 | if (len < sizeof(int)) |
1819 | return -EINVAL; | |
1820 | len = sizeof(int); | |
1821 | val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0; | |
1822 | if (put_user(len, optlen) || put_user(val, optval)) | |
1823 | return -EFAULT; | |
1824 | err = 0; | |
1825 | break; | |
9a4595bc PM |
1826 | default: |
1827 | err = -ENOPROTOOPT; | |
1828 | } | |
1829 | return err; | |
1830 | } | |
1831 | ||
1832 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1833 | { | |
1834 | struct nl_pktinfo info; | |
1835 | ||
1836 | info.group = NETLINK_CB(skb).dst_group; | |
1837 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1838 | } | |
1839 | ||
59324cf3 ND |
1840 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1841 | struct sk_buff *skb) | |
1842 | { | |
1843 | if (!NETLINK_CB(skb).nsid_is_set) | |
1844 | return; | |
1845 | ||
1846 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1847 | &NETLINK_CB(skb).nsid); | |
1848 | } | |
1849 | ||
1b784140 | 1850 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1851 | { |
1da177e4 LT |
1852 | struct sock *sk = sock->sk; |
1853 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1854 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1855 | u32 dst_portid; |
d629b836 | 1856 | u32 dst_group; |
1da177e4 LT |
1857 | struct sk_buff *skb; |
1858 | int err; | |
1859 | struct scm_cookie scm; | |
2d7a85f4 | 1860 | u32 netlink_skb_flags = 0; |
1da177e4 LT |
1861 | |
1862 | if (msg->msg_flags&MSG_OOB) | |
1863 | return -EOPNOTSUPP; | |
1864 | ||
7cc05662 | 1865 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1866 | if (err < 0) |
1867 | return err; | |
1868 | ||
1869 | if (msg->msg_namelen) { | |
b47030c7 | 1870 | err = -EINVAL; |
6091f09c ED |
1871 | if (msg->msg_namelen < sizeof(struct sockaddr_nl)) |
1872 | goto out; | |
1da177e4 | 1873 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1874 | goto out; |
15e47304 | 1875 | dst_portid = addr->nl_pid; |
d629b836 | 1876 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1877 | err = -EPERM; |
15e47304 | 1878 | if ((dst_group || dst_portid) && |
5187cd05 | 1879 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1880 | goto out; |
2d7a85f4 | 1881 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1882 | } else { |
15e47304 | 1883 | dst_portid = nlk->dst_portid; |
d629b836 | 1884 | dst_group = nlk->dst_group; |
1da177e4 LT |
1885 | } |
1886 | ||
da314c99 | 1887 | if (!nlk->bound) { |
1da177e4 LT |
1888 | err = netlink_autobind(sock); |
1889 | if (err) | |
1890 | goto out; | |
da314c99 HX |
1891 | } else { |
1892 | /* Ensure nlk is hashed and visible. */ | |
1893 | smp_rmb(); | |
1da177e4 LT |
1894 | } |
1895 | ||
1896 | err = -EMSGSIZE; | |
1897 | if (len > sk->sk_sndbuf - 32) | |
1898 | goto out; | |
1899 | err = -ENOBUFS; | |
3a36515f | 1900 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1901 | if (skb == NULL) |
1da177e4 LT |
1902 | goto out; |
1903 | ||
15e47304 | 1904 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1905 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1906 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1907 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1908 | |
1da177e4 | 1909 | err = -EFAULT; |
6ce8e9ce | 1910 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1911 | kfree_skb(skb); |
1912 | goto out; | |
1913 | } | |
1914 | ||
1915 | err = security_netlink_send(sk, skb); | |
1916 | if (err) { | |
1917 | kfree_skb(skb); | |
1918 | goto out; | |
1919 | } | |
1920 | ||
d629b836 | 1921 | if (dst_group) { |
63354797 | 1922 | refcount_inc(&skb->users); |
15e47304 | 1923 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1924 | } |
15e47304 | 1925 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1926 | |
1927 | out: | |
7cc05662 | 1928 | scm_destroy(&scm); |
1da177e4 LT |
1929 | return err; |
1930 | } | |
1931 | ||
1b784140 | 1932 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1933 | int flags) |
1934 | { | |
1da177e4 LT |
1935 | struct scm_cookie scm; |
1936 | struct sock *sk = sock->sk; | |
1937 | struct netlink_sock *nlk = nlk_sk(sk); | |
1938 | int noblock = flags&MSG_DONTWAIT; | |
1939 | size_t copied; | |
68d6ac6d | 1940 | struct sk_buff *skb, *data_skb; |
b44d211e | 1941 | int err, ret; |
1da177e4 LT |
1942 | |
1943 | if (flags&MSG_OOB) | |
1944 | return -EOPNOTSUPP; | |
1945 | ||
1946 | copied = 0; | |
1947 | ||
6ac552fd PM |
1948 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1949 | if (skb == NULL) | |
1da177e4 LT |
1950 | goto out; |
1951 | ||
68d6ac6d JB |
1952 | data_skb = skb; |
1953 | ||
1dacc76d JB |
1954 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1955 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1956 | /* |
68d6ac6d JB |
1957 | * If this skb has a frag_list, then here that means that we |
1958 | * will have to use the frag_list skb's data for compat tasks | |
1959 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1960 | * |
68d6ac6d JB |
1961 | * If we need to send the compat skb, assign it to the |
1962 | * 'data_skb' variable so that it will be used below for data | |
1963 | * copying. We keep 'skb' for everything else, including | |
1964 | * freeing both later. | |
1dacc76d | 1965 | */ |
68d6ac6d JB |
1966 | if (flags & MSG_CMSG_COMPAT) |
1967 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1968 | } |
1969 | #endif | |
1970 | ||
9063e21f ED |
1971 | /* Record the max length of recvmsg() calls for future allocations */ |
1972 | nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); | |
1973 | nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, | |
d35c99ff | 1974 | SKB_WITH_OVERHEAD(32768)); |
9063e21f | 1975 | |
68d6ac6d | 1976 | copied = data_skb->len; |
1da177e4 LT |
1977 | if (len < copied) { |
1978 | msg->msg_flags |= MSG_TRUNC; | |
1979 | copied = len; | |
1980 | } | |
1981 | ||
68d6ac6d | 1982 | skb_reset_transport_header(data_skb); |
51f3d02b | 1983 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
1984 | |
1985 | if (msg->msg_name) { | |
342dfc30 | 1986 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
1987 | addr->nl_family = AF_NETLINK; |
1988 | addr->nl_pad = 0; | |
15e47304 | 1989 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1990 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1991 | msg->msg_namelen = sizeof(*addr); |
1992 | } | |
1993 | ||
cc3a572f | 1994 | if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
cc9a06cd | 1995 | netlink_cmsg_recv_pktinfo(msg, skb); |
59324cf3 ND |
1996 | if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
1997 | netlink_cmsg_listen_all_nsid(sk, msg, skb); | |
cc9a06cd | 1998 | |
7cc05662 CH |
1999 | memset(&scm, 0, sizeof(scm)); |
2000 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 2001 | if (flags & MSG_TRUNC) |
68d6ac6d | 2002 | copied = data_skb->len; |
daa3766e | 2003 | |
1da177e4 LT |
2004 | skb_free_datagram(sk, skb); |
2005 | ||
16b304f3 PS |
2006 | if (nlk->cb_running && |
2007 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
2008 | ret = netlink_dump(sk); |
2009 | if (ret) { | |
ac30ef83 | 2010 | sk->sk_err = -ret; |
b44d211e AV |
2011 | sk->sk_error_report(sk); |
2012 | } | |
2013 | } | |
1da177e4 | 2014 | |
7cc05662 | 2015 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
2016 | out: |
2017 | netlink_rcv_wake(sk); | |
2018 | return err ? : copied; | |
2019 | } | |
2020 | ||
676d2369 | 2021 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 2022 | { |
cd40b7d3 | 2023 | BUG(); |
1da177e4 LT |
2024 | } |
2025 | ||
2026 | /* | |
746fac4d | 2027 | * We export these functions to other modules. They provide a |
1da177e4 LT |
2028 | * complete set of kernel non-blocking support for message |
2029 | * queueing. | |
2030 | */ | |
2031 | ||
2032 | struct sock * | |
9f00d977 PNA |
2033 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
2034 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
2035 | { |
2036 | struct socket *sock; | |
2037 | struct sock *sk; | |
77247bbb | 2038 | struct netlink_sock *nlk; |
5c398dc8 | 2039 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
2040 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
2041 | unsigned int groups; | |
1da177e4 | 2042 | |
fab2caf6 | 2043 | BUG_ON(!nl_table); |
1da177e4 | 2044 | |
6ac552fd | 2045 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
2046 | return NULL; |
2047 | ||
2048 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
2049 | return NULL; | |
13d3078e EB |
2050 | |
2051 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
2052 | goto out_sock_release_nosk; |
2053 | ||
2054 | sk = sock->sk; | |
4fdb3bb7 | 2055 | |
a31f2d17 | 2056 | if (!cfg || cfg->groups < 32) |
4277a083 | 2057 | groups = 32; |
a31f2d17 PNA |
2058 | else |
2059 | groups = cfg->groups; | |
4277a083 | 2060 | |
5c398dc8 | 2061 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
2062 | if (!listeners) |
2063 | goto out_sock_release; | |
2064 | ||
1da177e4 | 2065 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
2066 | if (cfg && cfg->input) |
2067 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 2068 | |
8ea65f4a | 2069 | if (netlink_insert(sk, 0)) |
77247bbb | 2070 | goto out_sock_release; |
4fdb3bb7 | 2071 | |
77247bbb | 2072 | nlk = nlk_sk(sk); |
cc3a572f | 2073 | nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
4fdb3bb7 | 2074 | |
4fdb3bb7 | 2075 | netlink_table_grab(); |
b4b51029 EB |
2076 | if (!nl_table[unit].registered) { |
2077 | nl_table[unit].groups = groups; | |
5c398dc8 | 2078 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
2079 | nl_table[unit].cb_mutex = cb_mutex; |
2080 | nl_table[unit].module = module; | |
9785e10a PNA |
2081 | if (cfg) { |
2082 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 2083 | nl_table[unit].unbind = cfg->unbind; |
9785e10a | 2084 | nl_table[unit].flags = cfg->flags; |
da12c90e G |
2085 | if (cfg->compare) |
2086 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 2087 | } |
b4b51029 | 2088 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
2089 | } else { |
2090 | kfree(listeners); | |
869e58f8 | 2091 | nl_table[unit].registered++; |
b4b51029 | 2092 | } |
4fdb3bb7 | 2093 | netlink_table_ungrab(); |
77247bbb PM |
2094 | return sk; |
2095 | ||
4fdb3bb7 | 2096 | out_sock_release: |
4277a083 | 2097 | kfree(listeners); |
9dfbec1f | 2098 | netlink_kernel_release(sk); |
23fe1866 PE |
2099 | return NULL; |
2100 | ||
2101 | out_sock_release_nosk: | |
4fdb3bb7 | 2102 | sock_release(sock); |
77247bbb | 2103 | return NULL; |
1da177e4 | 2104 | } |
9f00d977 | 2105 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
2106 | |
2107 | void | |
2108 | netlink_kernel_release(struct sock *sk) | |
2109 | { | |
13d3078e EB |
2110 | if (sk == NULL || sk->sk_socket == NULL) |
2111 | return; | |
2112 | ||
2113 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
2114 | } |
2115 | EXPORT_SYMBOL(netlink_kernel_release); | |
2116 | ||
d136f1bd | 2117 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 2118 | { |
5c398dc8 | 2119 | struct listeners *new, *old; |
b4ff4f04 | 2120 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2121 | |
2122 | if (groups < 32) | |
2123 | groups = 32; | |
2124 | ||
b4ff4f04 | 2125 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2126 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2127 | if (!new) | |
d136f1bd | 2128 | return -ENOMEM; |
6d772ac5 | 2129 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2130 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2131 | rcu_assign_pointer(tbl->listeners, new); | |
2132 | ||
37b6b935 | 2133 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2134 | } |
2135 | tbl->groups = groups; | |
2136 | ||
d136f1bd JB |
2137 | return 0; |
2138 | } | |
2139 | ||
2140 | /** | |
2141 | * netlink_change_ngroups - change number of multicast groups | |
2142 | * | |
2143 | * This changes the number of multicast groups that are available | |
2144 | * on a certain netlink family. Note that it is not possible to | |
2145 | * change the number of groups to below 32. Also note that it does | |
2146 | * not implicitly call netlink_clear_multicast_users() when the | |
2147 | * number of groups is reduced. | |
2148 | * | |
2149 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2150 | * @groups: The new number of groups. | |
2151 | */ | |
2152 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2153 | { | |
2154 | int err; | |
2155 | ||
2156 | netlink_table_grab(); | |
2157 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2158 | netlink_table_ungrab(); |
d136f1bd | 2159 | |
b4ff4f04 JB |
2160 | return err; |
2161 | } | |
b4ff4f04 | 2162 | |
b8273570 JB |
2163 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2164 | { | |
2165 | struct sock *sk; | |
b8273570 JB |
2166 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2167 | ||
b67bfe0d | 2168 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2169 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2170 | } | |
2171 | ||
a46621a3 | 2172 | struct nlmsghdr * |
15e47304 | 2173 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2174 | { |
2175 | struct nlmsghdr *nlh; | |
573ce260 | 2176 | int size = nlmsg_msg_size(len); |
a46621a3 | 2177 | |
4df864c1 | 2178 | nlh = skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2179 | nlh->nlmsg_type = type; |
2180 | nlh->nlmsg_len = size; | |
2181 | nlh->nlmsg_flags = flags; | |
15e47304 | 2182 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2183 | nlh->nlmsg_seq = seq; |
2184 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2185 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2186 | return nlh; |
2187 | } | |
2188 | EXPORT_SYMBOL(__nlmsg_put); | |
2189 | ||
1da177e4 LT |
2190 | /* |
2191 | * It looks a bit ugly. | |
2192 | * It would be better to create kernel thread. | |
2193 | */ | |
2194 | ||
2195 | static int netlink_dump(struct sock *sk) | |
2196 | { | |
2197 | struct netlink_sock *nlk = nlk_sk(sk); | |
4a19edb6 | 2198 | struct netlink_ext_ack extack = {}; |
1da177e4 | 2199 | struct netlink_callback *cb; |
c7ac8679 | 2200 | struct sk_buff *skb = NULL; |
1da177e4 | 2201 | struct nlmsghdr *nlh; |
92964c79 | 2202 | struct module *module; |
0642840b | 2203 | int err = -ENOBUFS; |
db65a3aa | 2204 | int alloc_min_size; |
c7ac8679 | 2205 | int alloc_size; |
1da177e4 | 2206 | |
af65bdfc | 2207 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2208 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2209 | err = -EINVAL; |
2210 | goto errout_skb; | |
1da177e4 LT |
2211 | } |
2212 | ||
d1b4c689 | 2213 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2214 | goto errout_skb; |
9063e21f ED |
2215 | |
2216 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2217 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2218 | * to reduce number of system calls on dump operations, if user | |
2219 | * ever provided a big enough buffer. | |
2220 | */ | |
db65a3aa AR |
2221 | cb = &nlk->cb; |
2222 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2223 | ||
2224 | if (alloc_min_size < nlk->max_recvmsg_len) { | |
2225 | alloc_size = nlk->max_recvmsg_len; | |
d35c99ff ED |
2226 | skb = alloc_skb(alloc_size, |
2227 | (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | | |
2228 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2229 | } |
db65a3aa AR |
2230 | if (!skb) { |
2231 | alloc_size = alloc_min_size; | |
c5b0db32 | 2232 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2233 | } |
c7ac8679 | 2234 | if (!skb) |
c63d6ea3 | 2235 | goto errout_skb; |
db65a3aa AR |
2236 | |
2237 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2238 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2239 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2240 | * could fit within the allocated skb. skb is typically allocated | |
2241 | * with larger space than required (could be as much as near 2x the | |
2242 | * requested size with align to next power of 2 approach). Allowing | |
2243 | * dump to use the excess space makes it difficult for a user to have a | |
2244 | * reasonable static buffer based on the expected largest dump of a | |
2245 | * single netdev. The outcome is MSG_TRUNC error. | |
2246 | */ | |
d1b4c689 | 2247 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
f9c22888 | 2248 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2249 | |
4a19edb6 DA |
2250 | if (nlk->dump_done_errno > 0) { |
2251 | cb->extack = &extack; | |
0642840b | 2252 | nlk->dump_done_errno = cb->dump(skb, cb); |
4a19edb6 DA |
2253 | cb->extack = NULL; |
2254 | } | |
1da177e4 | 2255 | |
0642840b JD |
2256 | if (nlk->dump_done_errno > 0 || |
2257 | skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { | |
af65bdfc | 2258 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2259 | |
2260 | if (sk_filter(sk, skb)) | |
2261 | kfree_skb(skb); | |
4a7e7c2a ED |
2262 | else |
2263 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2264 | return 0; |
2265 | } | |
2266 | ||
0642840b | 2267 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, |
22e6c58b DA |
2268 | sizeof(nlk->dump_done_errno), |
2269 | NLM_F_MULTI | cb->answer_flags); | |
0642840b | 2270 | if (WARN_ON(!nlh)) |
bf8b79e4 TG |
2271 | goto errout_skb; |
2272 | ||
670dc283 JB |
2273 | nl_dump_check_consistent(cb, nlh); |
2274 | ||
0642840b JD |
2275 | memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, |
2276 | sizeof(nlk->dump_done_errno)); | |
bf8b79e4 | 2277 | |
4a19edb6 DA |
2278 | if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) { |
2279 | nlh->nlmsg_flags |= NLM_F_ACK_TLVS; | |
2280 | if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg)) | |
2281 | nlmsg_end(skb, nlh); | |
2282 | } | |
2283 | ||
b1153f29 SH |
2284 | if (sk_filter(sk, skb)) |
2285 | kfree_skb(skb); | |
4a7e7c2a ED |
2286 | else |
2287 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2288 | |
a8f74b22 TG |
2289 | if (cb->done) |
2290 | cb->done(cb); | |
1da177e4 | 2291 | |
16b304f3 | 2292 | nlk->cb_running = false; |
92964c79 HX |
2293 | module = cb->module; |
2294 | skb = cb->skb; | |
16b304f3 | 2295 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2296 | module_put(module); |
2297 | consume_skb(skb); | |
1da177e4 | 2298 | return 0; |
1797754e | 2299 | |
bf8b79e4 | 2300 | errout_skb: |
af65bdfc | 2301 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2302 | kfree_skb(skb); |
bf8b79e4 | 2303 | return err; |
1da177e4 LT |
2304 | } |
2305 | ||
6dc878a8 G |
2306 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2307 | const struct nlmsghdr *nlh, | |
2308 | struct netlink_dump_control *control) | |
1da177e4 | 2309 | { |
89d35528 | 2310 | struct netlink_sock *nlk, *nlk2; |
1da177e4 LT |
2311 | struct netlink_callback *cb; |
2312 | struct sock *sk; | |
b44d211e | 2313 | int ret; |
1da177e4 | 2314 | |
63354797 | 2315 | refcount_inc(&skb->users); |
f9c22888 | 2316 | |
15e47304 | 2317 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2318 | if (sk == NULL) { |
16b304f3 PS |
2319 | ret = -ECONNREFUSED; |
2320 | goto error_free; | |
1da177e4 | 2321 | } |
6dc878a8 | 2322 | |
16b304f3 | 2323 | nlk = nlk_sk(sk); |
af65bdfc | 2324 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2325 | /* A dump is in progress... */ |
16b304f3 | 2326 | if (nlk->cb_running) { |
6dc878a8 | 2327 | ret = -EBUSY; |
16b304f3 | 2328 | goto error_unlock; |
1da177e4 | 2329 | } |
6dc878a8 | 2330 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2331 | if (!try_module_get(control->module)) { |
6dc878a8 | 2332 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2333 | goto error_unlock; |
6dc878a8 G |
2334 | } |
2335 | ||
16b304f3 PS |
2336 | cb = &nlk->cb; |
2337 | memset(cb, 0, sizeof(*cb)); | |
2338 | cb->dump = control->dump; | |
2339 | cb->done = control->done; | |
2340 | cb->nlh = nlh; | |
2341 | cb->data = control->data; | |
2342 | cb->module = control->module; | |
2343 | cb->min_dump_alloc = control->min_dump_alloc; | |
2344 | cb->skb = skb; | |
2345 | ||
89d35528 DA |
2346 | nlk2 = nlk_sk(NETLINK_CB(skb).sk); |
2347 | cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK); | |
2348 | ||
3730cf4d FW |
2349 | if (control->start) { |
2350 | ret = control->start(cb); | |
41c87425 | 2351 | if (ret) |
b87b6194 | 2352 | goto error_put; |
41c87425 JD |
2353 | } |
2354 | ||
16b304f3 | 2355 | nlk->cb_running = true; |
0642840b | 2356 | nlk->dump_done_errno = INT_MAX; |
16b304f3 | 2357 | |
af65bdfc | 2358 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2359 | |
41c87425 | 2360 | ret = netlink_dump(sk); |
fc9e50f5 | 2361 | |
1da177e4 | 2362 | sock_put(sk); |
5c58298c | 2363 | |
b44d211e AV |
2364 | if (ret) |
2365 | return ret; | |
2366 | ||
5c58298c DL |
2367 | /* We successfully started a dump, by returning -EINTR we |
2368 | * signal not to send ACK even if it was requested. | |
2369 | */ | |
2370 | return -EINTR; | |
16b304f3 | 2371 | |
b87b6194 JD |
2372 | error_put: |
2373 | module_put(control->module); | |
16b304f3 PS |
2374 | error_unlock: |
2375 | sock_put(sk); | |
2376 | mutex_unlock(nlk->cb_mutex); | |
2377 | error_free: | |
2378 | kfree_skb(skb); | |
2379 | return ret; | |
1da177e4 | 2380 | } |
6dc878a8 | 2381 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 | 2382 | |
2d4bc933 JB |
2383 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
2384 | const struct netlink_ext_ack *extack) | |
1da177e4 LT |
2385 | { |
2386 | struct sk_buff *skb; | |
2387 | struct nlmsghdr *rep; | |
2388 | struct nlmsgerr *errmsg; | |
339bf98f | 2389 | size_t payload = sizeof(*errmsg); |
2d4bc933 | 2390 | size_t tlvlen = 0; |
0a6a3a23 | 2391 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
2d4bc933 | 2392 | unsigned int flags = 0; |
48044eb4 | 2393 | bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK; |
1da177e4 | 2394 | |
0a6a3a23 | 2395 | /* Error messages get the original request appened, unless the user |
2d4bc933 JB |
2396 | * requests to cap the error message, and get extra error data if |
2397 | * requested. | |
0a6a3a23 | 2398 | */ |
4f6265d4 DA |
2399 | if (nlk_has_extack && extack && extack->_msg) |
2400 | tlvlen += nla_total_size(strlen(extack->_msg) + 1); | |
2401 | ||
2d4bc933 JB |
2402 | if (err) { |
2403 | if (!(nlk->flags & NETLINK_F_CAP_ACK)) | |
2404 | payload += nlmsg_len(nlh); | |
2405 | else | |
2406 | flags |= NLM_F_CAPPED; | |
4f6265d4 DA |
2407 | if (nlk_has_extack && extack && extack->bad_attr) |
2408 | tlvlen += nla_total_size(sizeof(u32)); | |
2d4bc933 JB |
2409 | } else { |
2410 | flags |= NLM_F_CAPPED; | |
ba0dc5f6 | 2411 | |
48044eb4 | 2412 | if (nlk_has_extack && extack && extack->cookie_len) |
ba0dc5f6 | 2413 | tlvlen += nla_total_size(extack->cookie_len); |
2d4bc933 | 2414 | } |
1da177e4 | 2415 | |
2d4bc933 JB |
2416 | if (tlvlen) |
2417 | flags |= NLM_F_ACK_TLVS; | |
2418 | ||
2419 | skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); | |
1da177e4 | 2420 | if (!skb) { |
a2084f56 JB |
2421 | NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; |
2422 | NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk); | |
1da177e4 LT |
2423 | return; |
2424 | } | |
2425 | ||
15e47304 | 2426 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
2d4bc933 | 2427 | NLMSG_ERROR, payload, flags); |
bf8b79e4 | 2428 | errmsg = nlmsg_data(rep); |
1da177e4 | 2429 | errmsg->error = err; |
0a6a3a23 | 2430 | memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
2d4bc933 | 2431 | |
48044eb4 | 2432 | if (nlk_has_extack && extack) { |
4f6265d4 DA |
2433 | if (extack->_msg) { |
2434 | WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, | |
2435 | extack->_msg)); | |
2436 | } | |
ba0dc5f6 | 2437 | if (err) { |
ba0dc5f6 JB |
2438 | if (extack->bad_attr && |
2439 | !WARN_ON((u8 *)extack->bad_attr < in_skb->data || | |
2440 | (u8 *)extack->bad_attr >= in_skb->data + | |
2441 | in_skb->len)) | |
2442 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, | |
2443 | (u8 *)extack->bad_attr - | |
2444 | in_skb->data)); | |
2445 | } else { | |
2446 | if (extack->cookie_len) | |
2447 | WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, | |
2448 | extack->cookie_len, | |
2449 | extack->cookie)); | |
2450 | } | |
2d4bc933 JB |
2451 | } |
2452 | ||
2453 | nlmsg_end(skb, rep); | |
2454 | ||
15e47304 | 2455 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2456 | } |
6ac552fd | 2457 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2458 | |
cd40b7d3 | 2459 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
2d4bc933 JB |
2460 | struct nlmsghdr *, |
2461 | struct netlink_ext_ack *)) | |
82ace47a | 2462 | { |
cbbdf843 | 2463 | struct netlink_ext_ack extack; |
82ace47a TG |
2464 | struct nlmsghdr *nlh; |
2465 | int err; | |
2466 | ||
2467 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2468 | int msglen; |
2469 | ||
cd443f1e | 2470 | memset(&extack, 0, sizeof(extack)); |
b529ccf2 | 2471 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2472 | err = 0; |
82ace47a | 2473 | |
ad8e4b75 | 2474 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2475 | return 0; |
2476 | ||
d35b6856 TG |
2477 | /* Only requests are handled by the kernel */ |
2478 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2479 | goto ack; |
45e7ae7f TG |
2480 | |
2481 | /* Skip control messages */ | |
2482 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2483 | goto ack; |
d35b6856 | 2484 | |
2d4bc933 | 2485 | err = cb(skb, nlh, &extack); |
5c58298c DL |
2486 | if (err == -EINTR) |
2487 | goto skip; | |
2488 | ||
2489 | ack: | |
d35b6856 | 2490 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
2d4bc933 | 2491 | netlink_ack(skb, nlh, err, &extack); |
82ace47a | 2492 | |
5c58298c | 2493 | skip: |
6ac552fd | 2494 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2495 | if (msglen > skb->len) |
2496 | msglen = skb->len; | |
2497 | skb_pull(skb, msglen); | |
82ace47a TG |
2498 | } |
2499 | ||
2500 | return 0; | |
2501 | } | |
6ac552fd | 2502 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2503 | |
d387f6ad TG |
2504 | /** |
2505 | * nlmsg_notify - send a notification netlink message | |
2506 | * @sk: netlink socket to use | |
2507 | * @skb: notification message | |
15e47304 | 2508 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2509 | * @group: destination multicast group or 0 |
2510 | * @report: 1 to report back, 0 to disable | |
2511 | * @flags: allocation flags | |
2512 | */ | |
15e47304 | 2513 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2514 | unsigned int group, int report, gfp_t flags) |
2515 | { | |
2516 | int err = 0; | |
2517 | ||
2518 | if (group) { | |
15e47304 | 2519 | int exclude_portid = 0; |
d387f6ad TG |
2520 | |
2521 | if (report) { | |
63354797 | 2522 | refcount_inc(&skb->users); |
15e47304 | 2523 | exclude_portid = portid; |
d387f6ad TG |
2524 | } |
2525 | ||
1ce85fe4 PNA |
2526 | /* errors reported via destination sk->sk_err, but propagate |
2527 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2528 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2529 | } |
2530 | ||
1ce85fe4 PNA |
2531 | if (report) { |
2532 | int err2; | |
2533 | ||
15e47304 | 2534 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2535 | if (!err || err == -ESRCH) |
2536 | err = err2; | |
2537 | } | |
d387f6ad TG |
2538 | |
2539 | return err; | |
2540 | } | |
6ac552fd | 2541 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2542 | |
1da177e4 LT |
2543 | #ifdef CONFIG_PROC_FS |
2544 | struct nl_seq_iter { | |
e372c414 | 2545 | struct seq_net_private p; |
56d28b1e | 2546 | struct rhashtable_iter hti; |
1da177e4 | 2547 | int link; |
1da177e4 LT |
2548 | }; |
2549 | ||
56d28b1e | 2550 | static int netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2551 | { |
6c4128f6 | 2552 | rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti); |
97a6ec4a TH |
2553 | rhashtable_walk_start(&iter->hti); |
2554 | ||
2555 | return 0; | |
1da177e4 LT |
2556 | } |
2557 | ||
56d28b1e | 2558 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2559 | { |
56d28b1e HX |
2560 | rhashtable_walk_stop(&iter->hti); |
2561 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2562 | } |
2563 | ||
56d28b1e | 2564 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2565 | { |
56d28b1e | 2566 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2567 | struct netlink_sock *nlk; |
1da177e4 | 2568 | |
56d28b1e HX |
2569 | do { |
2570 | for (;;) { | |
2571 | int err; | |
1da177e4 | 2572 | |
56d28b1e | 2573 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2574 | |
56d28b1e HX |
2575 | if (IS_ERR(nlk)) { |
2576 | if (PTR_ERR(nlk) == -EAGAIN) | |
2577 | continue; | |
e341694e | 2578 | |
56d28b1e HX |
2579 | return nlk; |
2580 | } | |
1da177e4 | 2581 | |
56d28b1e HX |
2582 | if (nlk) |
2583 | break; | |
1da177e4 | 2584 | |
56d28b1e HX |
2585 | netlink_walk_stop(iter); |
2586 | if (++iter->link >= MAX_LINKS) | |
2587 | return NULL; | |
da12c90e | 2588 | |
56d28b1e HX |
2589 | err = netlink_walk_start(iter); |
2590 | if (err) | |
2591 | return ERR_PTR(err); | |
1da177e4 | 2592 | } |
56d28b1e | 2593 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2594 | |
56d28b1e HX |
2595 | return nlk; |
2596 | } | |
1da177e4 | 2597 | |
56d28b1e HX |
2598 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
2599 | { | |
2600 | struct nl_seq_iter *iter = seq->private; | |
2601 | void *obj = SEQ_START_TOKEN; | |
2602 | loff_t pos; | |
2603 | int err; | |
2604 | ||
2605 | iter->link = 0; | |
2606 | ||
2607 | err = netlink_walk_start(iter); | |
2608 | if (err) | |
2609 | return ERR_PTR(err); | |
2610 | ||
2611 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2612 | obj = __netlink_seq_next(seq); | |
2613 | ||
2614 | return obj; | |
2615 | } | |
2616 | ||
2617 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2618 | { | |
2619 | ++*pos; | |
2620 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2621 | } |
2622 | ||
2623 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2624 | { | |
56d28b1e HX |
2625 | struct nl_seq_iter *iter = seq->private; |
2626 | ||
2627 | if (iter->link >= MAX_LINKS) | |
2628 | return; | |
2629 | ||
2630 | netlink_walk_stop(iter); | |
1da177e4 LT |
2631 | } |
2632 | ||
2633 | ||
2634 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2635 | { | |
658cb354 | 2636 | if (v == SEQ_START_TOKEN) { |
1da177e4 | 2637 | seq_puts(seq, |
ae552ac2 YB |
2638 | "sk Eth Pid Groups " |
2639 | "Rmem Wmem Dump Locks Drops Inode\n"); | |
658cb354 | 2640 | } else { |
1da177e4 LT |
2641 | struct sock *s = v; |
2642 | struct netlink_sock *nlk = nlk_sk(s); | |
2643 | ||
ae552ac2 | 2644 | seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8d %-8lu\n", |
1da177e4 LT |
2645 | s, |
2646 | s->sk_protocol, | |
15e47304 | 2647 | nlk->portid, |
513c2500 | 2648 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2649 | sk_rmem_alloc_get(s), |
2650 | sk_wmem_alloc_get(s), | |
16b304f3 | 2651 | nlk->cb_running, |
41c6d650 | 2652 | refcount_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2653 | atomic_read(&s->sk_drops), |
2654 | sock_i_ino(s) | |
1da177e4 LT |
2655 | ); |
2656 | ||
2657 | } | |
2658 | return 0; | |
2659 | } | |
2660 | ||
56b3d975 | 2661 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2662 | .start = netlink_seq_start, |
2663 | .next = netlink_seq_next, | |
2664 | .stop = netlink_seq_stop, | |
2665 | .show = netlink_seq_show, | |
2666 | }; | |
1da177e4 LT |
2667 | #endif |
2668 | ||
2669 | int netlink_register_notifier(struct notifier_block *nb) | |
2670 | { | |
efa172f4 | 2671 | return blocking_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2672 | } |
6ac552fd | 2673 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2674 | |
2675 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2676 | { | |
efa172f4 | 2677 | return blocking_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2678 | } |
6ac552fd | 2679 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2680 | |
90ddc4f0 | 2681 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2682 | .family = PF_NETLINK, |
2683 | .owner = THIS_MODULE, | |
2684 | .release = netlink_release, | |
2685 | .bind = netlink_bind, | |
2686 | .connect = netlink_connect, | |
2687 | .socketpair = sock_no_socketpair, | |
2688 | .accept = sock_no_accept, | |
2689 | .getname = netlink_getname, | |
a11e1d43 | 2690 | .poll = datagram_poll, |
025c6818 | 2691 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2692 | .listen = sock_no_listen, |
2693 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2694 | .setsockopt = netlink_setsockopt, |
2695 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2696 | .sendmsg = netlink_sendmsg, |
2697 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2698 | .mmap = sock_no_mmap, |
1da177e4 LT |
2699 | .sendpage = sock_no_sendpage, |
2700 | }; | |
2701 | ||
ec1b4cf7 | 2702 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2703 | .family = PF_NETLINK, |
2704 | .create = netlink_create, | |
2705 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2706 | }; | |
2707 | ||
4665079c | 2708 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2709 | { |
2710 | #ifdef CONFIG_PROC_FS | |
c3506372 CH |
2711 | if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops, |
2712 | sizeof(struct nl_seq_iter))) | |
b4b51029 EB |
2713 | return -ENOMEM; |
2714 | #endif | |
2715 | return 0; | |
2716 | } | |
2717 | ||
4665079c | 2718 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2719 | { |
2720 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2721 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2722 | #endif |
2723 | } | |
2724 | ||
b963ea89 DM |
2725 | static void __init netlink_add_usersock_entry(void) |
2726 | { | |
5c398dc8 | 2727 | struct listeners *listeners; |
b963ea89 DM |
2728 | int groups = 32; |
2729 | ||
5c398dc8 | 2730 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2731 | if (!listeners) |
5c398dc8 | 2732 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2733 | |
2734 | netlink_table_grab(); | |
2735 | ||
2736 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2737 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2738 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2739 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2740 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2741 | |
2742 | netlink_table_ungrab(); | |
2743 | } | |
2744 | ||
022cbae6 | 2745 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2746 | .init = netlink_net_init, |
2747 | .exit = netlink_net_exit, | |
2748 | }; | |
2749 | ||
49f7b33e | 2750 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2751 | { |
2752 | const struct netlink_sock *nlk = data; | |
2753 | struct netlink_compare_arg arg; | |
2754 | ||
da314c99 | 2755 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2756 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2757 | } |
2758 | ||
2759 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2760 | .head_offset = offsetof(struct netlink_sock, node), | |
2761 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2762 | .obj_hashfn = netlink_hash, |
2763 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2764 | .automatic_shrinking = true, |
c428ecd1 HX |
2765 | }; |
2766 | ||
1da177e4 LT |
2767 | static int __init netlink_proto_init(void) |
2768 | { | |
1da177e4 | 2769 | int i; |
1da177e4 LT |
2770 | int err = proto_register(&netlink_proto, 0); |
2771 | ||
2772 | if (err != 0) | |
2773 | goto out; | |
2774 | ||
fab25745 | 2775 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 2776 | |
0da974f4 | 2777 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2778 | if (!nl_table) |
2779 | goto panic; | |
1da177e4 | 2780 | |
1da177e4 | 2781 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2782 | if (rhashtable_init(&nl_table[i].hash, |
2783 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2784 | while (--i > 0) |
2785 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2786 | kfree(nl_table); |
fab2caf6 | 2787 | goto panic; |
1da177e4 | 2788 | } |
1da177e4 LT |
2789 | } |
2790 | ||
b963ea89 DM |
2791 | netlink_add_usersock_entry(); |
2792 | ||
1da177e4 | 2793 | sock_register(&netlink_family_ops); |
b4b51029 | 2794 | register_pernet_subsys(&netlink_net_ops); |
25e3f70f | 2795 | register_pernet_subsys(&netlink_tap_net_ops); |
746fac4d | 2796 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2797 | rtnetlink_init(); |
2798 | out: | |
2799 | return err; | |
fab2caf6 AM |
2800 | panic: |
2801 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2802 | } |
2803 | ||
1da177e4 | 2804 | core_initcall(netlink_proto_init); |