Commit | Line | Data |
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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> | |
43 | #include <asm/uaccess.h> | |
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> |
54e0f520 | 65 | |
457c4cbc | 66 | #include <net/net_namespace.h> |
1da177e4 LT |
67 | #include <net/sock.h> |
68 | #include <net/scm.h> | |
82ace47a | 69 | #include <net/netlink.h> |
1da177e4 | 70 | |
0f29c768 | 71 | #include "af_netlink.h" |
1da177e4 | 72 | |
5c398dc8 ED |
73 | struct listeners { |
74 | struct rcu_head rcu; | |
75 | unsigned long masks[0]; | |
6c04bb18 JB |
76 | }; |
77 | ||
cd967e05 | 78 | /* state bits */ |
cc3a572f | 79 | #define NETLINK_S_CONGESTED 0x0 |
cd967e05 PM |
80 | |
81 | /* flags */ | |
cc3a572f ND |
82 | #define NETLINK_F_KERNEL_SOCKET 0x1 |
83 | #define NETLINK_F_RECV_PKTINFO 0x2 | |
84 | #define NETLINK_F_BROADCAST_SEND_ERROR 0x4 | |
85 | #define NETLINK_F_RECV_NO_ENOBUFS 0x8 | |
59324cf3 | 86 | #define NETLINK_F_LISTEN_ALL_NSID 0x10 |
0a6a3a23 | 87 | #define NETLINK_F_CAP_ACK 0x20 |
77247bbb | 88 | |
035c4c16 | 89 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 | 90 | { |
cc3a572f | 91 | return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; |
aed81560 DL |
92 | } |
93 | ||
91dd93f9 | 94 | struct netlink_table *nl_table __read_mostly; |
0f29c768 | 95 | EXPORT_SYMBOL_GPL(nl_table); |
1da177e4 LT |
96 | |
97 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
98 | ||
99 | static int netlink_dump(struct sock *sk); | |
9652e931 | 100 | static void netlink_skb_destructor(struct sk_buff *skb); |
1da177e4 | 101 | |
78fd1d0a | 102 | /* nl_table locking explained: |
21e4902a | 103 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
c5adde94 | 104 | * and removal are protected with per bucket lock while using RCU list |
21e4902a TG |
105 | * modification primitives and may run in parallel to RCU protected lookups. |
106 | * Destruction of the Netlink socket may only occur *after* nl_table_lock has | |
107 | * been acquired * either during or after the socket has been removed from | |
108 | * the list and after an RCU grace period. | |
78fd1d0a | 109 | */ |
0f29c768 AV |
110 | DEFINE_RWLOCK(nl_table_lock); |
111 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
112 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
113 | ||
6d772ac5 ED |
114 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
115 | ||
e041c683 | 116 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 117 | |
bcbde0d4 DB |
118 | static DEFINE_SPINLOCK(netlink_tap_lock); |
119 | static struct list_head netlink_tap_all __read_mostly; | |
120 | ||
c428ecd1 HX |
121 | static const struct rhashtable_params netlink_rhashtable_params; |
122 | ||
b57ef81f | 123 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
124 | { |
125 | return group ? 1 << (group - 1) : 0; | |
126 | } | |
127 | ||
1853c949 DB |
128 | static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
129 | gfp_t gfp_mask) | |
130 | { | |
131 | unsigned int len = skb_end_offset(skb); | |
132 | struct sk_buff *new; | |
133 | ||
134 | new = alloc_skb(len, gfp_mask); | |
135 | if (new == NULL) | |
136 | return NULL; | |
137 | ||
138 | NETLINK_CB(new).portid = NETLINK_CB(skb).portid; | |
139 | NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; | |
140 | NETLINK_CB(new).creds = NETLINK_CB(skb).creds; | |
141 | ||
142 | memcpy(skb_put(new, len), skb->data, len); | |
143 | return new; | |
144 | } | |
145 | ||
bcbde0d4 DB |
146 | int netlink_add_tap(struct netlink_tap *nt) |
147 | { | |
148 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) | |
149 | return -EINVAL; | |
150 | ||
151 | spin_lock(&netlink_tap_lock); | |
152 | list_add_rcu(&nt->list, &netlink_tap_all); | |
153 | spin_unlock(&netlink_tap_lock); | |
154 | ||
fcd4d35e | 155 | __module_get(nt->module); |
bcbde0d4 DB |
156 | |
157 | return 0; | |
158 | } | |
159 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
160 | ||
2173f8d9 | 161 | static int __netlink_remove_tap(struct netlink_tap *nt) |
bcbde0d4 DB |
162 | { |
163 | bool found = false; | |
164 | struct netlink_tap *tmp; | |
165 | ||
166 | spin_lock(&netlink_tap_lock); | |
167 | ||
168 | list_for_each_entry(tmp, &netlink_tap_all, list) { | |
169 | if (nt == tmp) { | |
170 | list_del_rcu(&nt->list); | |
171 | found = true; | |
172 | goto out; | |
173 | } | |
174 | } | |
175 | ||
176 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
177 | out: | |
178 | spin_unlock(&netlink_tap_lock); | |
179 | ||
92b80eb3 | 180 | if (found) |
bcbde0d4 DB |
181 | module_put(nt->module); |
182 | ||
183 | return found ? 0 : -ENODEV; | |
184 | } | |
bcbde0d4 DB |
185 | |
186 | int netlink_remove_tap(struct netlink_tap *nt) | |
187 | { | |
188 | int ret; | |
189 | ||
190 | ret = __netlink_remove_tap(nt); | |
191 | synchronize_net(); | |
192 | ||
193 | return ret; | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
196 | ||
5ffd5cdd DB |
197 | static bool netlink_filter_tap(const struct sk_buff *skb) |
198 | { | |
199 | struct sock *sk = skb->sk; | |
5ffd5cdd DB |
200 | |
201 | /* We take the more conservative approach and | |
202 | * whitelist socket protocols that may pass. | |
203 | */ | |
204 | switch (sk->sk_protocol) { | |
205 | case NETLINK_ROUTE: | |
206 | case NETLINK_USERSOCK: | |
207 | case NETLINK_SOCK_DIAG: | |
208 | case NETLINK_NFLOG: | |
209 | case NETLINK_XFRM: | |
210 | case NETLINK_FIB_LOOKUP: | |
211 | case NETLINK_NETFILTER: | |
212 | case NETLINK_GENERIC: | |
498044bb | 213 | return true; |
5ffd5cdd DB |
214 | } |
215 | ||
498044bb | 216 | return false; |
5ffd5cdd DB |
217 | } |
218 | ||
bcbde0d4 DB |
219 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
220 | struct net_device *dev) | |
221 | { | |
222 | struct sk_buff *nskb; | |
5ffd5cdd | 223 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
224 | int ret = -ENOMEM; |
225 | ||
226 | dev_hold(dev); | |
1853c949 | 227 | |
d1b4c689 | 228 | if (is_vmalloc_addr(skb->head)) |
1853c949 DB |
229 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
230 | else | |
231 | nskb = skb_clone(skb, GFP_ATOMIC); | |
bcbde0d4 DB |
232 | if (nskb) { |
233 | nskb->dev = dev; | |
5ffd5cdd | 234 | nskb->protocol = htons((u16) sk->sk_protocol); |
604d13c9 DB |
235 | nskb->pkt_type = netlink_is_kernel(sk) ? |
236 | PACKET_KERNEL : PACKET_USER; | |
4e48ed88 | 237 | skb_reset_network_header(nskb); |
bcbde0d4 DB |
238 | ret = dev_queue_xmit(nskb); |
239 | if (unlikely(ret > 0)) | |
240 | ret = net_xmit_errno(ret); | |
241 | } | |
242 | ||
243 | dev_put(dev); | |
244 | return ret; | |
245 | } | |
246 | ||
247 | static void __netlink_deliver_tap(struct sk_buff *skb) | |
248 | { | |
249 | int ret; | |
250 | struct netlink_tap *tmp; | |
251 | ||
5ffd5cdd DB |
252 | if (!netlink_filter_tap(skb)) |
253 | return; | |
254 | ||
bcbde0d4 DB |
255 | list_for_each_entry_rcu(tmp, &netlink_tap_all, list) { |
256 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); | |
257 | if (unlikely(ret)) | |
258 | break; | |
259 | } | |
260 | } | |
261 | ||
262 | static void netlink_deliver_tap(struct sk_buff *skb) | |
263 | { | |
264 | rcu_read_lock(); | |
265 | ||
266 | if (unlikely(!list_empty(&netlink_tap_all))) | |
267 | __netlink_deliver_tap(skb); | |
268 | ||
269 | rcu_read_unlock(); | |
270 | } | |
271 | ||
73bfd370 DB |
272 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
273 | struct sk_buff *skb) | |
274 | { | |
275 | if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) | |
276 | netlink_deliver_tap(skb); | |
277 | } | |
278 | ||
cd1df525 PM |
279 | static void netlink_overrun(struct sock *sk) |
280 | { | |
281 | struct netlink_sock *nlk = nlk_sk(sk); | |
282 | ||
cc3a572f ND |
283 | if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { |
284 | if (!test_and_set_bit(NETLINK_S_CONGESTED, | |
285 | &nlk_sk(sk)->state)) { | |
cd1df525 PM |
286 | sk->sk_err = ENOBUFS; |
287 | sk->sk_error_report(sk); | |
288 | } | |
289 | } | |
290 | atomic_inc(&sk->sk_drops); | |
291 | } | |
292 | ||
293 | static void netlink_rcv_wake(struct sock *sk) | |
294 | { | |
295 | struct netlink_sock *nlk = nlk_sk(sk); | |
296 | ||
297 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
cc3a572f ND |
298 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
299 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) | |
cd1df525 PM |
300 | wake_up_interruptible(&nlk->wait); |
301 | } | |
302 | ||
cf0a018a PM |
303 | static void netlink_skb_destructor(struct sk_buff *skb) |
304 | { | |
c05cdb1b | 305 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
306 | if (!skb->cloned || |
307 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
308 | vfree(skb->head); | |
309 | ||
c05cdb1b PNA |
310 | skb->head = NULL; |
311 | } | |
9652e931 PM |
312 | if (skb->sk != NULL) |
313 | sock_rfree(skb); | |
cf0a018a PM |
314 | } |
315 | ||
316 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
317 | { | |
318 | WARN_ON(skb->sk != NULL); | |
319 | skb->sk = sk; | |
320 | skb->destructor = netlink_skb_destructor; | |
321 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
322 | sk_mem_charge(sk, skb->truesize); | |
323 | } | |
324 | ||
1da177e4 LT |
325 | static void netlink_sock_destruct(struct sock *sk) |
326 | { | |
3f660d66 HX |
327 | struct netlink_sock *nlk = nlk_sk(sk); |
328 | ||
16b304f3 PS |
329 | if (nlk->cb_running) { |
330 | if (nlk->cb.done) | |
331 | nlk->cb.done(&nlk->cb); | |
6dc878a8 | 332 | |
16b304f3 PS |
333 | module_put(nlk->cb.module); |
334 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
335 | } |
336 | ||
1da177e4 LT |
337 | skb_queue_purge(&sk->sk_receive_queue); |
338 | ||
339 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 340 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
341 | return; |
342 | } | |
547b792c IJ |
343 | |
344 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
345 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
346 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
347 | } |
348 | ||
6ac552fd PM |
349 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
350 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
351 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
352 | * this, _but_ remember, it adds useless work on UP machines. | |
353 | */ | |
354 | ||
d136f1bd | 355 | void netlink_table_grab(void) |
9a429c49 | 356 | __acquires(nl_table_lock) |
1da177e4 | 357 | { |
d136f1bd JB |
358 | might_sleep(); |
359 | ||
6abd219c | 360 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
361 | |
362 | if (atomic_read(&nl_table_users)) { | |
363 | DECLARE_WAITQUEUE(wait, current); | |
364 | ||
365 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 366 | for (;;) { |
1da177e4 LT |
367 | set_current_state(TASK_UNINTERRUPTIBLE); |
368 | if (atomic_read(&nl_table_users) == 0) | |
369 | break; | |
6abd219c | 370 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 371 | schedule(); |
6abd219c | 372 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
373 | } |
374 | ||
375 | __set_current_state(TASK_RUNNING); | |
376 | remove_wait_queue(&nl_table_wait, &wait); | |
377 | } | |
378 | } | |
379 | ||
d136f1bd | 380 | void netlink_table_ungrab(void) |
9a429c49 | 381 | __releases(nl_table_lock) |
1da177e4 | 382 | { |
6abd219c | 383 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
384 | wake_up(&nl_table_wait); |
385 | } | |
386 | ||
6ac552fd | 387 | static inline void |
1da177e4 LT |
388 | netlink_lock_table(void) |
389 | { | |
390 | /* read_lock() synchronizes us to netlink_table_grab */ | |
391 | ||
392 | read_lock(&nl_table_lock); | |
393 | atomic_inc(&nl_table_users); | |
394 | read_unlock(&nl_table_lock); | |
395 | } | |
396 | ||
6ac552fd | 397 | static inline void |
1da177e4 LT |
398 | netlink_unlock_table(void) |
399 | { | |
400 | if (atomic_dec_and_test(&nl_table_users)) | |
401 | wake_up(&nl_table_wait); | |
402 | } | |
403 | ||
e341694e | 404 | struct netlink_compare_arg |
1da177e4 | 405 | { |
c428ecd1 | 406 | possible_net_t pnet; |
e341694e TG |
407 | u32 portid; |
408 | }; | |
1da177e4 | 409 | |
8f2ddaac HX |
410 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
411 | #define netlink_compare_arg_len \ | |
412 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
413 | |
414 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
415 | const void *ptr) | |
1da177e4 | 416 | { |
c428ecd1 HX |
417 | const struct netlink_compare_arg *x = arg->key; |
418 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 419 | |
da314c99 | 420 | return nlk->portid != x->portid || |
c428ecd1 HX |
421 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
422 | } | |
423 | ||
424 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
425 | struct net *net, u32 portid) | |
426 | { | |
427 | memset(arg, 0, sizeof(*arg)); | |
428 | write_pnet(&arg->pnet, net); | |
429 | arg->portid = portid; | |
1da177e4 LT |
430 | } |
431 | ||
e341694e TG |
432 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
433 | struct net *net) | |
1da177e4 | 434 | { |
c428ecd1 | 435 | struct netlink_compare_arg arg; |
1da177e4 | 436 | |
c428ecd1 HX |
437 | netlink_compare_arg_init(&arg, net, portid); |
438 | return rhashtable_lookup_fast(&table->hash, &arg, | |
439 | netlink_rhashtable_params); | |
1da177e4 LT |
440 | } |
441 | ||
c428ecd1 | 442 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 443 | { |
c428ecd1 | 444 | struct netlink_compare_arg arg; |
c5adde94 | 445 | |
da314c99 | 446 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
447 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
448 | &nlk_sk(sk)->node, | |
449 | netlink_rhashtable_params); | |
c5adde94 YX |
450 | } |
451 | ||
e341694e | 452 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 453 | { |
e341694e TG |
454 | struct netlink_table *table = &nl_table[protocol]; |
455 | struct sock *sk; | |
1da177e4 | 456 | |
e341694e TG |
457 | rcu_read_lock(); |
458 | sk = __netlink_lookup(table, portid, net); | |
459 | if (sk) | |
460 | sock_hold(sk); | |
461 | rcu_read_unlock(); | |
1da177e4 | 462 | |
e341694e | 463 | return sk; |
1da177e4 LT |
464 | } |
465 | ||
90ddc4f0 | 466 | static const struct proto_ops netlink_ops; |
1da177e4 | 467 | |
4277a083 PM |
468 | static void |
469 | netlink_update_listeners(struct sock *sk) | |
470 | { | |
471 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
472 | unsigned long mask; |
473 | unsigned int i; | |
6d772ac5 ED |
474 | struct listeners *listeners; |
475 | ||
476 | listeners = nl_deref_protected(tbl->listeners); | |
477 | if (!listeners) | |
478 | return; | |
4277a083 | 479 | |
b4ff4f04 | 480 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 481 | mask = 0; |
b67bfe0d | 482 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
483 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
484 | mask |= nlk_sk(sk)->groups[i]; | |
485 | } | |
6d772ac5 | 486 | listeners->masks[i] = mask; |
4277a083 PM |
487 | } |
488 | /* this function is only called with the netlink table "grabbed", which | |
489 | * makes sure updates are visible before bind or setsockopt return. */ | |
490 | } | |
491 | ||
8ea65f4a | 492 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 493 | { |
da12c90e | 494 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 495 | int err; |
1da177e4 | 496 | |
c5adde94 | 497 | lock_sock(sk); |
1da177e4 | 498 | |
da314c99 HX |
499 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
500 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
501 | goto err; |
502 | ||
503 | err = -ENOMEM; | |
97defe1e TG |
504 | if (BITS_PER_LONG > 32 && |
505 | unlikely(atomic_read(&table->hash.nelems) >= UINT_MAX)) | |
1da177e4 LT |
506 | goto err; |
507 | ||
da314c99 | 508 | nlk_sk(sk)->portid = portid; |
e341694e | 509 | sock_hold(sk); |
919d9db9 | 510 | |
c428ecd1 HX |
511 | err = __netlink_insert(table, sk); |
512 | if (err) { | |
4e7c1330 DB |
513 | /* In case the hashtable backend returns with -EBUSY |
514 | * from here, it must not escape to the caller. | |
515 | */ | |
516 | if (unlikely(err == -EBUSY)) | |
517 | err = -EOVERFLOW; | |
c428ecd1 HX |
518 | if (err == -EEXIST) |
519 | err = -EADDRINUSE; | |
c5adde94 | 520 | sock_put(sk); |
1f770c0a | 521 | goto err; |
919d9db9 HX |
522 | } |
523 | ||
da314c99 HX |
524 | /* We need to ensure that the socket is hashed and visible. */ |
525 | smp_wmb(); | |
526 | nlk_sk(sk)->bound = portid; | |
1f770c0a | 527 | |
1da177e4 | 528 | err: |
c5adde94 | 529 | release_sock(sk); |
1da177e4 LT |
530 | return err; |
531 | } | |
532 | ||
533 | static void netlink_remove(struct sock *sk) | |
534 | { | |
e341694e TG |
535 | struct netlink_table *table; |
536 | ||
e341694e | 537 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
538 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
539 | netlink_rhashtable_params)) { | |
e341694e TG |
540 | WARN_ON(atomic_read(&sk->sk_refcnt) == 1); |
541 | __sock_put(sk); | |
542 | } | |
e341694e | 543 | |
1da177e4 | 544 | netlink_table_grab(); |
b10dcb3b | 545 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 546 | __sk_del_bind_node(sk); |
b10dcb3b JB |
547 | netlink_update_listeners(sk); |
548 | } | |
ee1c2442 JB |
549 | if (sk->sk_protocol == NETLINK_GENERIC) |
550 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
551 | netlink_table_ungrab(); |
552 | } | |
553 | ||
554 | static struct proto netlink_proto = { | |
555 | .name = "NETLINK", | |
556 | .owner = THIS_MODULE, | |
557 | .obj_size = sizeof(struct netlink_sock), | |
558 | }; | |
559 | ||
1b8d7ae4 | 560 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
561 | struct mutex *cb_mutex, int protocol, |
562 | int kern) | |
1da177e4 LT |
563 | { |
564 | struct sock *sk; | |
565 | struct netlink_sock *nlk; | |
ab33a171 PM |
566 | |
567 | sock->ops = &netlink_ops; | |
568 | ||
11aa9c28 | 569 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
570 | if (!sk) |
571 | return -ENOMEM; | |
572 | ||
573 | sock_init_data(sock, sk); | |
574 | ||
575 | nlk = nlk_sk(sk); | |
658cb354 | 576 | if (cb_mutex) { |
ffa4d721 | 577 | nlk->cb_mutex = cb_mutex; |
658cb354 | 578 | } else { |
ffa4d721 PM |
579 | nlk->cb_mutex = &nlk->cb_def_mutex; |
580 | mutex_init(nlk->cb_mutex); | |
581 | } | |
ab33a171 PM |
582 | init_waitqueue_head(&nlk->wait); |
583 | ||
584 | sk->sk_destruct = netlink_sock_destruct; | |
585 | sk->sk_protocol = protocol; | |
586 | return 0; | |
587 | } | |
588 | ||
3f378b68 EP |
589 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
590 | int kern) | |
ab33a171 PM |
591 | { |
592 | struct module *module = NULL; | |
af65bdfc | 593 | struct mutex *cb_mutex; |
f7fa9b10 | 594 | struct netlink_sock *nlk; |
023e2cfa JB |
595 | int (*bind)(struct net *net, int group); |
596 | void (*unbind)(struct net *net, int group); | |
ab33a171 | 597 | int err = 0; |
1da177e4 LT |
598 | |
599 | sock->state = SS_UNCONNECTED; | |
600 | ||
601 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
602 | return -ESOCKTNOSUPPORT; | |
603 | ||
6ac552fd | 604 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
605 | return -EPROTONOSUPPORT; |
606 | ||
77247bbb | 607 | netlink_lock_table(); |
95a5afca | 608 | #ifdef CONFIG_MODULES |
ab33a171 | 609 | if (!nl_table[protocol].registered) { |
77247bbb | 610 | netlink_unlock_table(); |
4fdb3bb7 | 611 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 612 | netlink_lock_table(); |
4fdb3bb7 | 613 | } |
ab33a171 PM |
614 | #endif |
615 | if (nl_table[protocol].registered && | |
616 | try_module_get(nl_table[protocol].module)) | |
617 | module = nl_table[protocol].module; | |
974c37e9 AD |
618 | else |
619 | err = -EPROTONOSUPPORT; | |
af65bdfc | 620 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 621 | bind = nl_table[protocol].bind; |
4f520900 | 622 | unbind = nl_table[protocol].unbind; |
77247bbb | 623 | netlink_unlock_table(); |
4fdb3bb7 | 624 | |
974c37e9 AD |
625 | if (err < 0) |
626 | goto out; | |
627 | ||
11aa9c28 | 628 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 629 | if (err < 0) |
f7fa9b10 PM |
630 | goto out_module; |
631 | ||
6f756a8c | 632 | local_bh_disable(); |
c1fd3b94 | 633 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
634 | local_bh_enable(); |
635 | ||
f7fa9b10 | 636 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 637 | nlk->module = module; |
03292745 | 638 | nlk->netlink_bind = bind; |
4f520900 | 639 | nlk->netlink_unbind = unbind; |
ab33a171 PM |
640 | out: |
641 | return err; | |
1da177e4 | 642 | |
ab33a171 PM |
643 | out_module: |
644 | module_put(module); | |
645 | goto out; | |
1da177e4 LT |
646 | } |
647 | ||
21e4902a TG |
648 | static void deferred_put_nlk_sk(struct rcu_head *head) |
649 | { | |
650 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
651 | ||
652 | sock_put(&nlk->sk); | |
653 | } | |
654 | ||
1da177e4 LT |
655 | static int netlink_release(struct socket *sock) |
656 | { | |
657 | struct sock *sk = sock->sk; | |
658 | struct netlink_sock *nlk; | |
659 | ||
660 | if (!sk) | |
661 | return 0; | |
662 | ||
663 | netlink_remove(sk); | |
ac57b3a9 | 664 | sock_orphan(sk); |
1da177e4 LT |
665 | nlk = nlk_sk(sk); |
666 | ||
3f660d66 HX |
667 | /* |
668 | * OK. Socket is unlinked, any packets that arrive now | |
669 | * will be purged. | |
670 | */ | |
1da177e4 | 671 | |
ee1c2442 JB |
672 | /* must not acquire netlink_table_lock in any way again before unbind |
673 | * and notifying genetlink is done as otherwise it might deadlock | |
674 | */ | |
675 | if (nlk->netlink_unbind) { | |
676 | int i; | |
677 | ||
678 | for (i = 0; i < nlk->ngroups; i++) | |
679 | if (test_bit(i, nlk->groups)) | |
680 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
681 | } | |
682 | if (sk->sk_protocol == NETLINK_GENERIC && | |
683 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
684 | wake_up(&genl_sk_destructing_waitq); | |
685 | ||
1da177e4 LT |
686 | sock->sk = NULL; |
687 | wake_up_interruptible_all(&nlk->wait); | |
688 | ||
689 | skb_queue_purge(&sk->sk_write_queue); | |
690 | ||
e2726020 | 691 | if (nlk->portid && nlk->bound) { |
1da177e4 | 692 | struct netlink_notify n = { |
3b1e0a65 | 693 | .net = sock_net(sk), |
1da177e4 | 694 | .protocol = sk->sk_protocol, |
15e47304 | 695 | .portid = nlk->portid, |
1da177e4 | 696 | }; |
e041c683 AS |
697 | atomic_notifier_call_chain(&netlink_chain, |
698 | NETLINK_URELEASE, &n); | |
746fac4d | 699 | } |
4fdb3bb7 | 700 | |
5e7c001c | 701 | module_put(nlk->module); |
4fdb3bb7 | 702 | |
aed81560 | 703 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 704 | netlink_table_grab(); |
869e58f8 DL |
705 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
706 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
707 | struct listeners *old; |
708 | ||
709 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
710 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
711 | kfree_rcu(old, rcu); | |
869e58f8 | 712 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 713 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 714 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 715 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
716 | nl_table[sk->sk_protocol].registered = 0; |
717 | } | |
b10dcb3b | 718 | netlink_table_ungrab(); |
658cb354 | 719 | } |
77247bbb | 720 | |
f7fa9b10 PM |
721 | kfree(nlk->groups); |
722 | nlk->groups = NULL; | |
723 | ||
3755810c | 724 | local_bh_disable(); |
c1fd3b94 | 725 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 726 | local_bh_enable(); |
21e4902a | 727 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
728 | return 0; |
729 | } | |
730 | ||
731 | static int netlink_autobind(struct socket *sock) | |
732 | { | |
733 | struct sock *sk = sock->sk; | |
3b1e0a65 | 734 | struct net *net = sock_net(sk); |
da12c90e | 735 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 736 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 737 | int err; |
b9fbe709 HX |
738 | s32 rover = -4096; |
739 | bool ok; | |
1da177e4 LT |
740 | |
741 | retry: | |
742 | cond_resched(); | |
e341694e | 743 | rcu_read_lock(); |
b9fbe709 HX |
744 | ok = !__netlink_lookup(table, portid, net); |
745 | rcu_read_unlock(); | |
746 | if (!ok) { | |
e341694e | 747 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
748 | if (rover == -4096) |
749 | /* rover will be in range [S32_MIN, -4097] */ | |
750 | rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); | |
751 | else if (rover >= -4096) | |
e341694e | 752 | rover = -4097; |
b9fbe709 | 753 | portid = rover--; |
e341694e | 754 | goto retry; |
1da177e4 | 755 | } |
1da177e4 | 756 | |
8ea65f4a | 757 | err = netlink_insert(sk, portid); |
1da177e4 LT |
758 | if (err == -EADDRINUSE) |
759 | goto retry; | |
d470e3b4 DM |
760 | |
761 | /* If 2 threads race to autobind, that is fine. */ | |
762 | if (err == -EBUSY) | |
763 | err = 0; | |
764 | ||
765 | return err; | |
1da177e4 LT |
766 | } |
767 | ||
aa4cf945 EB |
768 | /** |
769 | * __netlink_ns_capable - General netlink message capability test | |
770 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. | |
771 | * @user_ns: The user namespace of the capability to use | |
772 | * @cap: The capability to use | |
773 | * | |
774 | * Test to see if the opener of the socket we received the message | |
775 | * from had when the netlink socket was created and the sender of the | |
776 | * message has has the capability @cap in the user namespace @user_ns. | |
777 | */ | |
778 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, | |
779 | struct user_namespace *user_ns, int cap) | |
780 | { | |
2d7a85f4 EB |
781 | return ((nsp->flags & NETLINK_SKB_DST) || |
782 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
783 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
784 | } |
785 | EXPORT_SYMBOL(__netlink_ns_capable); | |
786 | ||
787 | /** | |
788 | * netlink_ns_capable - General netlink message capability test | |
789 | * @skb: socket buffer holding a netlink command from userspace | |
790 | * @user_ns: The user namespace of the capability to use | |
791 | * @cap: The capability to use | |
792 | * | |
793 | * Test to see if the opener of the socket we received the message | |
794 | * from had when the netlink socket was created and the sender of the | |
795 | * message has has the capability @cap in the user namespace @user_ns. | |
796 | */ | |
797 | bool netlink_ns_capable(const struct sk_buff *skb, | |
798 | struct user_namespace *user_ns, int cap) | |
799 | { | |
800 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
801 | } | |
802 | EXPORT_SYMBOL(netlink_ns_capable); | |
803 | ||
804 | /** | |
805 | * netlink_capable - Netlink global message capability test | |
806 | * @skb: socket buffer holding a netlink command from userspace | |
807 | * @cap: The capability to use | |
808 | * | |
809 | * Test to see if the opener of the socket we received the message | |
810 | * from had when the netlink socket was created and the sender of the | |
811 | * message has has the capability @cap in all user namespaces. | |
812 | */ | |
813 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
814 | { | |
815 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
816 | } | |
817 | EXPORT_SYMBOL(netlink_capable); | |
818 | ||
819 | /** | |
820 | * netlink_net_capable - Netlink network namespace message capability test | |
821 | * @skb: socket buffer holding a netlink command from userspace | |
822 | * @cap: The capability to use | |
823 | * | |
824 | * Test to see if the opener of the socket we received the message | |
825 | * from had when the netlink socket was created and the sender of the | |
826 | * message has has the capability @cap over the network namespace of | |
827 | * the socket we received the message from. | |
828 | */ | |
829 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
830 | { | |
831 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
832 | } | |
833 | EXPORT_SYMBOL(netlink_net_capable); | |
834 | ||
5187cd05 | 835 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 836 | { |
9785e10a | 837 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 838 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 839 | } |
1da177e4 | 840 | |
f7fa9b10 PM |
841 | static void |
842 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
843 | { | |
844 | struct netlink_sock *nlk = nlk_sk(sk); | |
845 | ||
846 | if (nlk->subscriptions && !subscriptions) | |
847 | __sk_del_bind_node(sk); | |
848 | else if (!nlk->subscriptions && subscriptions) | |
849 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
850 | nlk->subscriptions = subscriptions; | |
851 | } | |
852 | ||
b4ff4f04 | 853 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
854 | { |
855 | struct netlink_sock *nlk = nlk_sk(sk); | |
856 | unsigned int groups; | |
b4ff4f04 | 857 | unsigned long *new_groups; |
513c2500 PM |
858 | int err = 0; |
859 | ||
b4ff4f04 JB |
860 | netlink_table_grab(); |
861 | ||
513c2500 | 862 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 863 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 864 | err = -ENOENT; |
b4ff4f04 JB |
865 | goto out_unlock; |
866 | } | |
513c2500 | 867 | |
b4ff4f04 JB |
868 | if (nlk->ngroups >= groups) |
869 | goto out_unlock; | |
513c2500 | 870 | |
b4ff4f04 JB |
871 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
872 | if (new_groups == NULL) { | |
873 | err = -ENOMEM; | |
874 | goto out_unlock; | |
875 | } | |
6ac552fd | 876 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
877 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
878 | ||
879 | nlk->groups = new_groups; | |
513c2500 | 880 | nlk->ngroups = groups; |
b4ff4f04 JB |
881 | out_unlock: |
882 | netlink_table_ungrab(); | |
883 | return err; | |
513c2500 PM |
884 | } |
885 | ||
02c81ab9 | 886 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 887 | struct sock *sk) |
4f520900 | 888 | { |
023e2cfa | 889 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
890 | int undo; |
891 | ||
892 | if (!nlk->netlink_unbind) | |
893 | return; | |
894 | ||
895 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 896 | if (test_bit(undo, &groups)) |
8b7c36d8 | 897 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
898 | } |
899 | ||
6ac552fd PM |
900 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
901 | int addr_len) | |
1da177e4 LT |
902 | { |
903 | struct sock *sk = sock->sk; | |
3b1e0a65 | 904 | struct net *net = sock_net(sk); |
1da177e4 LT |
905 | struct netlink_sock *nlk = nlk_sk(sk); |
906 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
907 | int err; | |
4f520900 | 908 | long unsigned int groups = nladdr->nl_groups; |
da314c99 | 909 | bool bound; |
746fac4d | 910 | |
4e4b5376 HFS |
911 | if (addr_len < sizeof(struct sockaddr_nl)) |
912 | return -EINVAL; | |
913 | ||
1da177e4 LT |
914 | if (nladdr->nl_family != AF_NETLINK) |
915 | return -EINVAL; | |
916 | ||
917 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 918 | if (groups) { |
5187cd05 | 919 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 920 | return -EPERM; |
b4ff4f04 JB |
921 | err = netlink_realloc_groups(sk); |
922 | if (err) | |
923 | return err; | |
513c2500 | 924 | } |
1da177e4 | 925 | |
da314c99 HX |
926 | bound = nlk->bound; |
927 | if (bound) { | |
928 | /* Ensure nlk->portid is up-to-date. */ | |
929 | smp_rmb(); | |
930 | ||
15e47304 | 931 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 932 | return -EINVAL; |
da314c99 | 933 | } |
4f520900 RGB |
934 | |
935 | if (nlk->netlink_bind && groups) { | |
936 | int group; | |
937 | ||
938 | for (group = 0; group < nlk->ngroups; group++) { | |
939 | if (!test_bit(group, &groups)) | |
940 | continue; | |
8b7c36d8 | 941 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
942 | if (!err) |
943 | continue; | |
023e2cfa | 944 | netlink_undo_bind(group, groups, sk); |
4f520900 RGB |
945 | return err; |
946 | } | |
947 | } | |
948 | ||
da314c99 HX |
949 | /* No need for barriers here as we return to user-space without |
950 | * using any of the bound attributes. | |
951 | */ | |
952 | if (!bound) { | |
1da177e4 | 953 | err = nladdr->nl_pid ? |
8ea65f4a | 954 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 955 | netlink_autobind(sock); |
4f520900 | 956 | if (err) { |
023e2cfa | 957 | netlink_undo_bind(nlk->ngroups, groups, sk); |
1da177e4 | 958 | return err; |
4f520900 | 959 | } |
1da177e4 LT |
960 | } |
961 | ||
4f520900 | 962 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
963 | return 0; |
964 | ||
965 | netlink_table_grab(); | |
f7fa9b10 | 966 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 967 | hweight32(groups) - |
746fac4d | 968 | hweight32(nlk->groups[0])); |
4f520900 | 969 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 970 | netlink_update_listeners(sk); |
1da177e4 LT |
971 | netlink_table_ungrab(); |
972 | ||
973 | return 0; | |
974 | } | |
975 | ||
976 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
977 | int alen, int flags) | |
978 | { | |
979 | int err = 0; | |
980 | struct sock *sk = sock->sk; | |
981 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 982 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 983 | |
6503d961 CG |
984 | if (alen < sizeof(addr->sa_family)) |
985 | return -EINVAL; | |
986 | ||
1da177e4 LT |
987 | if (addr->sa_family == AF_UNSPEC) { |
988 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 989 | nlk->dst_portid = 0; |
d629b836 | 990 | nlk->dst_group = 0; |
1da177e4 LT |
991 | return 0; |
992 | } | |
993 | if (addr->sa_family != AF_NETLINK) | |
994 | return -EINVAL; | |
995 | ||
46833a86 | 996 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 997 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
998 | return -EPERM; |
999 | ||
da314c99 HX |
1000 | /* No need for barriers here as we return to user-space without |
1001 | * using any of the bound attributes. | |
1002 | */ | |
1003 | if (!nlk->bound) | |
1da177e4 LT |
1004 | err = netlink_autobind(sock); |
1005 | ||
1006 | if (err == 0) { | |
1007 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1008 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1009 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1010 | } |
1011 | ||
1012 | return err; | |
1013 | } | |
1014 | ||
6ac552fd PM |
1015 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
1016 | int *addr_len, int peer) | |
1da177e4 LT |
1017 | { |
1018 | struct sock *sk = sock->sk; | |
1019 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1020 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1021 | |
1da177e4 LT |
1022 | nladdr->nl_family = AF_NETLINK; |
1023 | nladdr->nl_pad = 0; | |
1024 | *addr_len = sizeof(*nladdr); | |
1025 | ||
1026 | if (peer) { | |
15e47304 | 1027 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1028 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1029 | } else { |
15e47304 | 1030 | nladdr->nl_pid = nlk->portid; |
513c2500 | 1031 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
1032 | } |
1033 | return 0; | |
1034 | } | |
1035 | ||
025c6818 DD |
1036 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1037 | unsigned long arg) | |
1038 | { | |
1039 | /* try to hand this ioctl down to the NIC drivers. | |
1040 | */ | |
1041 | return -ENOIOCTLCMD; | |
1042 | } | |
1043 | ||
15e47304 | 1044 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1045 | { |
1da177e4 LT |
1046 | struct sock *sock; |
1047 | struct netlink_sock *nlk; | |
1048 | ||
15e47304 | 1049 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1050 | if (!sock) |
1051 | return ERR_PTR(-ECONNREFUSED); | |
1052 | ||
1053 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1054 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1055 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1056 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1057 | sock_put(sock); |
1058 | return ERR_PTR(-ECONNREFUSED); | |
1059 | } | |
1060 | return sock; | |
1061 | } | |
1062 | ||
1063 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1064 | { | |
496ad9aa | 1065 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1066 | struct sock *sock; |
1067 | ||
1068 | if (!S_ISSOCK(inode->i_mode)) | |
1069 | return ERR_PTR(-ENOTSOCK); | |
1070 | ||
1071 | sock = SOCKET_I(inode)->sk; | |
1072 | if (sock->sk_family != AF_NETLINK) | |
1073 | return ERR_PTR(-EINVAL); | |
1074 | ||
1075 | sock_hold(sock); | |
1076 | return sock; | |
1077 | } | |
1078 | ||
3a36515f PN |
1079 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1080 | int broadcast) | |
c05cdb1b PNA |
1081 | { |
1082 | struct sk_buff *skb; | |
1083 | void *data; | |
1084 | ||
3a36515f | 1085 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1086 | return alloc_skb(size, GFP_KERNEL); |
1087 | ||
3a36515f PN |
1088 | size = SKB_DATA_ALIGN(size) + |
1089 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1090 | |
1091 | data = vmalloc(size); | |
1092 | if (data == NULL) | |
3a36515f | 1093 | return NULL; |
c05cdb1b | 1094 | |
2ea2f62c | 1095 | skb = __build_skb(data, size); |
3a36515f PN |
1096 | if (skb == NULL) |
1097 | vfree(data); | |
2ea2f62c | 1098 | else |
3a36515f | 1099 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1100 | |
1101 | return skb; | |
c05cdb1b PNA |
1102 | } |
1103 | ||
1da177e4 LT |
1104 | /* |
1105 | * Attach a skb to a netlink socket. | |
1106 | * The caller must hold a reference to the destination socket. On error, the | |
1107 | * reference is dropped. The skb is not send to the destination, just all | |
1108 | * all error checks are performed and memory in the queue is reserved. | |
1109 | * Return values: | |
1110 | * < 0: error. skb freed, reference to sock dropped. | |
1111 | * 0: continue | |
1112 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1113 | */ | |
9457afee | 1114 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1115 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1116 | { |
1117 | struct netlink_sock *nlk; | |
1118 | ||
1119 | nlk = nlk_sk(sk); | |
1120 | ||
5fd96123 | 1121 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1122 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1123 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1124 | if (!*timeo) { |
aed81560 | 1125 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1126 | netlink_overrun(sk); |
1127 | sock_put(sk); | |
1128 | kfree_skb(skb); | |
1129 | return -EAGAIN; | |
1130 | } | |
1131 | ||
1132 | __set_current_state(TASK_INTERRUPTIBLE); | |
1133 | add_wait_queue(&nlk->wait, &wait); | |
1134 | ||
1135 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1136 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1137 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1138 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1139 | |
1140 | __set_current_state(TASK_RUNNING); | |
1141 | remove_wait_queue(&nlk->wait, &wait); | |
1142 | sock_put(sk); | |
1143 | ||
1144 | if (signal_pending(current)) { | |
1145 | kfree_skb(skb); | |
c3d8d1e3 | 1146 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1147 | } |
1148 | return 1; | |
1149 | } | |
cf0a018a | 1150 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1151 | return 0; |
1152 | } | |
1153 | ||
4a7e7c2a | 1154 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1155 | { |
1da177e4 LT |
1156 | int len = skb->len; |
1157 | ||
bcbde0d4 DB |
1158 | netlink_deliver_tap(skb); |
1159 | ||
d1b4c689 | 1160 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1161 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1162 | return len; |
1163 | } | |
1164 | ||
1165 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1166 | { | |
1167 | int len = __netlink_sendskb(sk, skb); | |
1168 | ||
1da177e4 LT |
1169 | sock_put(sk); |
1170 | return len; | |
1171 | } | |
1172 | ||
1173 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1174 | { | |
1175 | kfree_skb(skb); | |
1176 | sock_put(sk); | |
1177 | } | |
1178 | ||
b57ef81f | 1179 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1180 | { |
1181 | int delta; | |
1182 | ||
1298ca46 | 1183 | WARN_ON(skb->sk != NULL); |
4305b541 | 1184 | delta = skb->end - skb->tail; |
c05cdb1b | 1185 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1186 | return skb; |
1187 | ||
1188 | if (skb_shared(skb)) { | |
1189 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1190 | if (!nskb) | |
1191 | return skb; | |
8460c00f | 1192 | consume_skb(skb); |
1da177e4 LT |
1193 | skb = nskb; |
1194 | } | |
1195 | ||
1196 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
1197 | skb->truesize -= delta; | |
1198 | ||
1199 | return skb; | |
1200 | } | |
1201 | ||
3fbc2905 EB |
1202 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1203 | struct sock *ssk) | |
cd40b7d3 DL |
1204 | { |
1205 | int ret; | |
1206 | struct netlink_sock *nlk = nlk_sk(sk); | |
1207 | ||
1208 | ret = -ECONNREFUSED; | |
1209 | if (nlk->netlink_rcv != NULL) { | |
1210 | ret = skb->len; | |
cf0a018a | 1211 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1212 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1213 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1214 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1215 | consume_skb(skb); |
1216 | } else { | |
1217 | kfree_skb(skb); | |
cd40b7d3 | 1218 | } |
cd40b7d3 DL |
1219 | sock_put(sk); |
1220 | return ret; | |
1221 | } | |
1222 | ||
1223 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1224 | u32 portid, int nonblock) |
1da177e4 LT |
1225 | { |
1226 | struct sock *sk; | |
1227 | int err; | |
1228 | long timeo; | |
1229 | ||
1230 | skb = netlink_trim(skb, gfp_any()); | |
1231 | ||
1232 | timeo = sock_sndtimeo(ssk, nonblock); | |
1233 | retry: | |
15e47304 | 1234 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1235 | if (IS_ERR(sk)) { |
1236 | kfree_skb(skb); | |
1237 | return PTR_ERR(sk); | |
1238 | } | |
cd40b7d3 | 1239 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1240 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1241 | |
b1153f29 | 1242 | if (sk_filter(sk, skb)) { |
84874607 | 1243 | err = skb->len; |
b1153f29 SH |
1244 | kfree_skb(skb); |
1245 | sock_put(sk); | |
1246 | return err; | |
1247 | } | |
1248 | ||
9457afee | 1249 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1250 | if (err == 1) |
1251 | goto retry; | |
1252 | if (err) | |
1253 | return err; | |
1254 | ||
7ee015e0 | 1255 | return netlink_sendskb(sk, skb); |
1da177e4 | 1256 | } |
6ac552fd | 1257 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1258 | |
4277a083 PM |
1259 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1260 | { | |
1261 | int res = 0; | |
5c398dc8 | 1262 | struct listeners *listeners; |
4277a083 | 1263 | |
aed81560 | 1264 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1265 | |
1266 | rcu_read_lock(); | |
1267 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1268 | ||
6d772ac5 | 1269 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1270 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1271 | |
1272 | rcu_read_unlock(); | |
1273 | ||
4277a083 PM |
1274 | return res; |
1275 | } | |
1276 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1277 | ||
b57ef81f | 1278 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1279 | { |
1280 | struct netlink_sock *nlk = nlk_sk(sk); | |
1281 | ||
1282 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1283 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1284 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1285 | __netlink_sendskb(sk, skb); |
2c645800 | 1286 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1287 | } |
1288 | return -1; | |
1289 | } | |
1290 | ||
1291 | struct netlink_broadcast_data { | |
1292 | struct sock *exclude_sk; | |
b4b51029 | 1293 | struct net *net; |
15e47304 | 1294 | u32 portid; |
1da177e4 LT |
1295 | u32 group; |
1296 | int failure; | |
ff491a73 | 1297 | int delivery_failure; |
1da177e4 LT |
1298 | int congested; |
1299 | int delivered; | |
7d877f3b | 1300 | gfp_t allocation; |
1da177e4 | 1301 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1302 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1303 | void *tx_data; | |
1da177e4 LT |
1304 | }; |
1305 | ||
46c9521f RR |
1306 | static void do_one_broadcast(struct sock *sk, |
1307 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1308 | { |
1309 | struct netlink_sock *nlk = nlk_sk(sk); | |
1310 | int val; | |
1311 | ||
1312 | if (p->exclude_sk == sk) | |
46c9521f | 1313 | return; |
1da177e4 | 1314 | |
15e47304 | 1315 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1316 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1317 | return; |
1da177e4 | 1318 | |
59324cf3 ND |
1319 | if (!net_eq(sock_net(sk), p->net)) { |
1320 | if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) | |
1321 | return; | |
1322 | ||
1323 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1324 | return; | |
1325 | ||
1326 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1327 | CAP_NET_BROADCAST)) | |
1328 | return; | |
1329 | } | |
b4b51029 | 1330 | |
1da177e4 LT |
1331 | if (p->failure) { |
1332 | netlink_overrun(sk); | |
46c9521f | 1333 | return; |
1da177e4 LT |
1334 | } |
1335 | ||
1336 | sock_hold(sk); | |
1337 | if (p->skb2 == NULL) { | |
68acc024 | 1338 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1339 | p->skb2 = skb_clone(p->skb, p->allocation); |
1340 | } else { | |
68acc024 TC |
1341 | p->skb2 = skb_get(p->skb); |
1342 | /* | |
1343 | * skb ownership may have been set when | |
1344 | * delivered to a previous socket. | |
1345 | */ | |
1346 | skb_orphan(p->skb2); | |
1da177e4 LT |
1347 | } |
1348 | } | |
1349 | if (p->skb2 == NULL) { | |
1350 | netlink_overrun(sk); | |
1351 | /* Clone failed. Notify ALL listeners. */ | |
1352 | p->failure = 1; | |
cc3a572f | 1353 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1354 | p->delivery_failure = 1; |
59324cf3 ND |
1355 | goto out; |
1356 | } | |
1357 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
910a7e90 EB |
1358 | kfree_skb(p->skb2); |
1359 | p->skb2 = NULL; | |
59324cf3 ND |
1360 | goto out; |
1361 | } | |
1362 | if (sk_filter(sk, p->skb2)) { | |
b1153f29 SH |
1363 | kfree_skb(p->skb2); |
1364 | p->skb2 = NULL; | |
59324cf3 ND |
1365 | goto out; |
1366 | } | |
1367 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
1368 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
1369 | val = netlink_broadcast_deliver(sk, p->skb2); | |
1370 | if (val < 0) { | |
1da177e4 | 1371 | netlink_overrun(sk); |
cc3a572f | 1372 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1373 | p->delivery_failure = 1; |
1da177e4 LT |
1374 | } else { |
1375 | p->congested |= val; | |
1376 | p->delivered = 1; | |
1377 | p->skb2 = NULL; | |
1378 | } | |
59324cf3 | 1379 | out: |
1da177e4 | 1380 | sock_put(sk); |
1da177e4 LT |
1381 | } |
1382 | ||
15e47304 | 1383 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1384 | u32 group, gfp_t allocation, |
1385 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1386 | void *filter_data) | |
1da177e4 | 1387 | { |
3b1e0a65 | 1388 | struct net *net = sock_net(ssk); |
1da177e4 | 1389 | struct netlink_broadcast_data info; |
1da177e4 LT |
1390 | struct sock *sk; |
1391 | ||
1392 | skb = netlink_trim(skb, allocation); | |
1393 | ||
1394 | info.exclude_sk = ssk; | |
b4b51029 | 1395 | info.net = net; |
15e47304 | 1396 | info.portid = portid; |
1da177e4 LT |
1397 | info.group = group; |
1398 | info.failure = 0; | |
ff491a73 | 1399 | info.delivery_failure = 0; |
1da177e4 LT |
1400 | info.congested = 0; |
1401 | info.delivered = 0; | |
1402 | info.allocation = allocation; | |
1403 | info.skb = skb; | |
1404 | info.skb2 = NULL; | |
910a7e90 EB |
1405 | info.tx_filter = filter; |
1406 | info.tx_data = filter_data; | |
1da177e4 LT |
1407 | |
1408 | /* While we sleep in clone, do not allow to change socket list */ | |
1409 | ||
1410 | netlink_lock_table(); | |
1411 | ||
b67bfe0d | 1412 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1413 | do_one_broadcast(sk, &info); |
1414 | ||
70d4bf6d | 1415 | consume_skb(skb); |
aa1c6a6f | 1416 | |
1da177e4 LT |
1417 | netlink_unlock_table(); |
1418 | ||
70d4bf6d NH |
1419 | if (info.delivery_failure) { |
1420 | kfree_skb(info.skb2); | |
ff491a73 | 1421 | return -ENOBUFS; |
658cb354 ED |
1422 | } |
1423 | consume_skb(info.skb2); | |
ff491a73 | 1424 | |
1da177e4 | 1425 | if (info.delivered) { |
d0164adc | 1426 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1427 | yield(); |
1428 | return 0; | |
1429 | } | |
1da177e4 LT |
1430 | return -ESRCH; |
1431 | } | |
910a7e90 EB |
1432 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1433 | ||
15e47304 | 1434 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1435 | u32 group, gfp_t allocation) |
1436 | { | |
15e47304 | 1437 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1438 | NULL, NULL); |
1439 | } | |
6ac552fd | 1440 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1441 | |
1442 | struct netlink_set_err_data { | |
1443 | struct sock *exclude_sk; | |
15e47304 | 1444 | u32 portid; |
1da177e4 LT |
1445 | u32 group; |
1446 | int code; | |
1447 | }; | |
1448 | ||
b57ef81f | 1449 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1450 | { |
1451 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1452 | int ret = 0; |
1da177e4 LT |
1453 | |
1454 | if (sk == p->exclude_sk) | |
1455 | goto out; | |
1456 | ||
09ad9bc7 | 1457 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1458 | goto out; |
1459 | ||
15e47304 | 1460 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1461 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1462 | goto out; |
1463 | ||
cc3a572f | 1464 | if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
1a50307b PNA |
1465 | ret = 1; |
1466 | goto out; | |
1467 | } | |
1468 | ||
1da177e4 LT |
1469 | sk->sk_err = p->code; |
1470 | sk->sk_error_report(sk); | |
1471 | out: | |
1a50307b | 1472 | return ret; |
1da177e4 LT |
1473 | } |
1474 | ||
4843b93c PNA |
1475 | /** |
1476 | * netlink_set_err - report error to broadcast listeners | |
1477 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1478 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1479 | * @group: the broadcast group that will notice the error |
4843b93c | 1480 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1481 | * |
1482 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1483 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1484 | */ |
15e47304 | 1485 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1486 | { |
1487 | struct netlink_set_err_data info; | |
1da177e4 | 1488 | struct sock *sk; |
1a50307b | 1489 | int ret = 0; |
1da177e4 LT |
1490 | |
1491 | info.exclude_sk = ssk; | |
15e47304 | 1492 | info.portid = portid; |
1da177e4 | 1493 | info.group = group; |
4843b93c PNA |
1494 | /* sk->sk_err wants a positive error value */ |
1495 | info.code = -code; | |
1da177e4 LT |
1496 | |
1497 | read_lock(&nl_table_lock); | |
1498 | ||
b67bfe0d | 1499 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1500 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1501 | |
1502 | read_unlock(&nl_table_lock); | |
1a50307b | 1503 | return ret; |
1da177e4 | 1504 | } |
dd5b6ce6 | 1505 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1506 | |
84659eb5 JB |
1507 | /* must be called with netlink table grabbed */ |
1508 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1509 | unsigned int group, | |
1510 | int is_new) | |
1511 | { | |
1512 | int old, new = !!is_new, subscriptions; | |
1513 | ||
1514 | old = test_bit(group - 1, nlk->groups); | |
1515 | subscriptions = nlk->subscriptions - old + new; | |
1516 | if (new) | |
1517 | __set_bit(group - 1, nlk->groups); | |
1518 | else | |
1519 | __clear_bit(group - 1, nlk->groups); | |
1520 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1521 | netlink_update_listeners(&nlk->sk); | |
1522 | } | |
1523 | ||
9a4595bc | 1524 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1525 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1526 | { |
1527 | struct sock *sk = sock->sk; | |
1528 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1529 | unsigned int val = 0; |
1530 | int err; | |
9a4595bc PM |
1531 | |
1532 | if (level != SOL_NETLINK) | |
1533 | return -ENOPROTOOPT; | |
1534 | ||
d1b4c689 | 1535 | if (optlen >= sizeof(int) && |
eb496534 | 1536 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1537 | return -EFAULT; |
1538 | ||
1539 | switch (optname) { | |
1540 | case NETLINK_PKTINFO: | |
1541 | if (val) | |
cc3a572f | 1542 | nlk->flags |= NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1543 | else |
cc3a572f | 1544 | nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1545 | err = 0; |
1546 | break; | |
1547 | case NETLINK_ADD_MEMBERSHIP: | |
1548 | case NETLINK_DROP_MEMBERSHIP: { | |
5187cd05 | 1549 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1550 | return -EPERM; |
b4ff4f04 JB |
1551 | err = netlink_realloc_groups(sk); |
1552 | if (err) | |
1553 | return err; | |
9a4595bc PM |
1554 | if (!val || val - 1 >= nlk->ngroups) |
1555 | return -EINVAL; | |
7774d5e0 | 1556 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1557 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1558 | if (err) |
1559 | return err; | |
1560 | } | |
9a4595bc | 1561 | netlink_table_grab(); |
84659eb5 JB |
1562 | netlink_update_socket_mc(nlk, val, |
1563 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1564 | netlink_table_ungrab(); |
7774d5e0 | 1565 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1566 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1567 | |
9a4595bc PM |
1568 | err = 0; |
1569 | break; | |
1570 | } | |
be0c22a4 PNA |
1571 | case NETLINK_BROADCAST_ERROR: |
1572 | if (val) | |
cc3a572f | 1573 | nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1574 | else |
cc3a572f | 1575 | nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 PNA |
1576 | err = 0; |
1577 | break; | |
38938bfe PNA |
1578 | case NETLINK_NO_ENOBUFS: |
1579 | if (val) { | |
cc3a572f ND |
1580 | nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
1581 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); | |
38938bfe | 1582 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1583 | } else { |
cc3a572f | 1584 | nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
658cb354 | 1585 | } |
38938bfe PNA |
1586 | err = 0; |
1587 | break; | |
59324cf3 ND |
1588 | case NETLINK_LISTEN_ALL_NSID: |
1589 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1590 | return -EPERM; | |
1591 | ||
1592 | if (val) | |
1593 | nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; | |
1594 | else | |
1595 | nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; | |
1596 | err = 0; | |
1597 | break; | |
0a6a3a23 CR |
1598 | case NETLINK_CAP_ACK: |
1599 | if (val) | |
1600 | nlk->flags |= NETLINK_F_CAP_ACK; | |
1601 | else | |
1602 | nlk->flags &= ~NETLINK_F_CAP_ACK; | |
1603 | err = 0; | |
1604 | break; | |
9a4595bc PM |
1605 | default: |
1606 | err = -ENOPROTOOPT; | |
1607 | } | |
1608 | return err; | |
1609 | } | |
1610 | ||
1611 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1612 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1613 | { |
1614 | struct sock *sk = sock->sk; | |
1615 | struct netlink_sock *nlk = nlk_sk(sk); | |
1616 | int len, val, err; | |
1617 | ||
1618 | if (level != SOL_NETLINK) | |
1619 | return -ENOPROTOOPT; | |
1620 | ||
1621 | if (get_user(len, optlen)) | |
1622 | return -EFAULT; | |
1623 | if (len < 0) | |
1624 | return -EINVAL; | |
1625 | ||
1626 | switch (optname) { | |
1627 | case NETLINK_PKTINFO: | |
1628 | if (len < sizeof(int)) | |
1629 | return -EINVAL; | |
1630 | len = sizeof(int); | |
cc3a572f | 1631 | val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
a27b58fe HC |
1632 | if (put_user(len, optlen) || |
1633 | put_user(val, optval)) | |
1634 | return -EFAULT; | |
9a4595bc PM |
1635 | err = 0; |
1636 | break; | |
be0c22a4 PNA |
1637 | case NETLINK_BROADCAST_ERROR: |
1638 | if (len < sizeof(int)) | |
1639 | return -EINVAL; | |
1640 | len = sizeof(int); | |
cc3a572f | 1641 | val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
be0c22a4 PNA |
1642 | if (put_user(len, optlen) || |
1643 | put_user(val, optval)) | |
1644 | return -EFAULT; | |
1645 | err = 0; | |
1646 | break; | |
38938bfe PNA |
1647 | case NETLINK_NO_ENOBUFS: |
1648 | if (len < sizeof(int)) | |
1649 | return -EINVAL; | |
1650 | len = sizeof(int); | |
cc3a572f | 1651 | val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
38938bfe PNA |
1652 | if (put_user(len, optlen) || |
1653 | put_user(val, optval)) | |
1654 | return -EFAULT; | |
1655 | err = 0; | |
1656 | break; | |
b42be38b DH |
1657 | case NETLINK_LIST_MEMBERSHIPS: { |
1658 | int pos, idx, shift; | |
1659 | ||
1660 | err = 0; | |
47191d65 | 1661 | netlink_lock_table(); |
b42be38b DH |
1662 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1663 | if (len - pos < sizeof(u32)) | |
1664 | break; | |
1665 | ||
1666 | idx = pos / sizeof(unsigned long); | |
1667 | shift = (pos % sizeof(unsigned long)) * 8; | |
1668 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1669 | (u32 __user *)(optval + pos))) { | |
1670 | err = -EFAULT; | |
1671 | break; | |
1672 | } | |
1673 | } | |
1674 | if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) | |
1675 | err = -EFAULT; | |
47191d65 | 1676 | netlink_unlock_table(); |
b42be38b DH |
1677 | break; |
1678 | } | |
0a6a3a23 CR |
1679 | case NETLINK_CAP_ACK: |
1680 | if (len < sizeof(int)) | |
1681 | return -EINVAL; | |
1682 | len = sizeof(int); | |
1683 | val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; | |
1684 | if (put_user(len, optlen) || | |
1685 | put_user(val, optval)) | |
1686 | return -EFAULT; | |
1687 | err = 0; | |
1688 | break; | |
9a4595bc PM |
1689 | default: |
1690 | err = -ENOPROTOOPT; | |
1691 | } | |
1692 | return err; | |
1693 | } | |
1694 | ||
1695 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1696 | { | |
1697 | struct nl_pktinfo info; | |
1698 | ||
1699 | info.group = NETLINK_CB(skb).dst_group; | |
1700 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1701 | } | |
1702 | ||
59324cf3 ND |
1703 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1704 | struct sk_buff *skb) | |
1705 | { | |
1706 | if (!NETLINK_CB(skb).nsid_is_set) | |
1707 | return; | |
1708 | ||
1709 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1710 | &NETLINK_CB(skb).nsid); | |
1711 | } | |
1712 | ||
1b784140 | 1713 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1714 | { |
1da177e4 LT |
1715 | struct sock *sk = sock->sk; |
1716 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1717 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1718 | u32 dst_portid; |
d629b836 | 1719 | u32 dst_group; |
1da177e4 LT |
1720 | struct sk_buff *skb; |
1721 | int err; | |
1722 | struct scm_cookie scm; | |
2d7a85f4 | 1723 | u32 netlink_skb_flags = 0; |
1da177e4 LT |
1724 | |
1725 | if (msg->msg_flags&MSG_OOB) | |
1726 | return -EOPNOTSUPP; | |
1727 | ||
7cc05662 | 1728 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1729 | if (err < 0) |
1730 | return err; | |
1731 | ||
1732 | if (msg->msg_namelen) { | |
b47030c7 | 1733 | err = -EINVAL; |
1da177e4 | 1734 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1735 | goto out; |
15e47304 | 1736 | dst_portid = addr->nl_pid; |
d629b836 | 1737 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1738 | err = -EPERM; |
15e47304 | 1739 | if ((dst_group || dst_portid) && |
5187cd05 | 1740 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1741 | goto out; |
2d7a85f4 | 1742 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1743 | } else { |
15e47304 | 1744 | dst_portid = nlk->dst_portid; |
d629b836 | 1745 | dst_group = nlk->dst_group; |
1da177e4 LT |
1746 | } |
1747 | ||
da314c99 | 1748 | if (!nlk->bound) { |
1da177e4 LT |
1749 | err = netlink_autobind(sock); |
1750 | if (err) | |
1751 | goto out; | |
da314c99 HX |
1752 | } else { |
1753 | /* Ensure nlk is hashed and visible. */ | |
1754 | smp_rmb(); | |
1da177e4 LT |
1755 | } |
1756 | ||
1757 | err = -EMSGSIZE; | |
1758 | if (len > sk->sk_sndbuf - 32) | |
1759 | goto out; | |
1760 | err = -ENOBUFS; | |
3a36515f | 1761 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1762 | if (skb == NULL) |
1da177e4 LT |
1763 | goto out; |
1764 | ||
15e47304 | 1765 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1766 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1767 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1768 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1769 | |
1da177e4 | 1770 | err = -EFAULT; |
6ce8e9ce | 1771 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1772 | kfree_skb(skb); |
1773 | goto out; | |
1774 | } | |
1775 | ||
1776 | err = security_netlink_send(sk, skb); | |
1777 | if (err) { | |
1778 | kfree_skb(skb); | |
1779 | goto out; | |
1780 | } | |
1781 | ||
d629b836 | 1782 | if (dst_group) { |
1da177e4 | 1783 | atomic_inc(&skb->users); |
15e47304 | 1784 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1785 | } |
15e47304 | 1786 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1787 | |
1788 | out: | |
7cc05662 | 1789 | scm_destroy(&scm); |
1da177e4 LT |
1790 | return err; |
1791 | } | |
1792 | ||
1b784140 | 1793 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1794 | int flags) |
1795 | { | |
1da177e4 LT |
1796 | struct scm_cookie scm; |
1797 | struct sock *sk = sock->sk; | |
1798 | struct netlink_sock *nlk = nlk_sk(sk); | |
1799 | int noblock = flags&MSG_DONTWAIT; | |
1800 | size_t copied; | |
68d6ac6d | 1801 | struct sk_buff *skb, *data_skb; |
b44d211e | 1802 | int err, ret; |
1da177e4 LT |
1803 | |
1804 | if (flags&MSG_OOB) | |
1805 | return -EOPNOTSUPP; | |
1806 | ||
1807 | copied = 0; | |
1808 | ||
6ac552fd PM |
1809 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1810 | if (skb == NULL) | |
1da177e4 LT |
1811 | goto out; |
1812 | ||
68d6ac6d JB |
1813 | data_skb = skb; |
1814 | ||
1dacc76d JB |
1815 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1816 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1817 | /* |
68d6ac6d JB |
1818 | * If this skb has a frag_list, then here that means that we |
1819 | * will have to use the frag_list skb's data for compat tasks | |
1820 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1821 | * |
68d6ac6d JB |
1822 | * If we need to send the compat skb, assign it to the |
1823 | * 'data_skb' variable so that it will be used below for data | |
1824 | * copying. We keep 'skb' for everything else, including | |
1825 | * freeing both later. | |
1dacc76d | 1826 | */ |
68d6ac6d JB |
1827 | if (flags & MSG_CMSG_COMPAT) |
1828 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1829 | } |
1830 | #endif | |
1831 | ||
9063e21f ED |
1832 | /* Record the max length of recvmsg() calls for future allocations */ |
1833 | nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); | |
1834 | nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, | |
1835 | 16384); | |
1836 | ||
68d6ac6d | 1837 | copied = data_skb->len; |
1da177e4 LT |
1838 | if (len < copied) { |
1839 | msg->msg_flags |= MSG_TRUNC; | |
1840 | copied = len; | |
1841 | } | |
1842 | ||
68d6ac6d | 1843 | skb_reset_transport_header(data_skb); |
51f3d02b | 1844 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
1845 | |
1846 | if (msg->msg_name) { | |
342dfc30 | 1847 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
1848 | addr->nl_family = AF_NETLINK; |
1849 | addr->nl_pad = 0; | |
15e47304 | 1850 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1851 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1852 | msg->msg_namelen = sizeof(*addr); |
1853 | } | |
1854 | ||
cc3a572f | 1855 | if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
cc9a06cd | 1856 | netlink_cmsg_recv_pktinfo(msg, skb); |
59324cf3 ND |
1857 | if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
1858 | netlink_cmsg_listen_all_nsid(sk, msg, skb); | |
cc9a06cd | 1859 | |
7cc05662 CH |
1860 | memset(&scm, 0, sizeof(scm)); |
1861 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1862 | if (flags & MSG_TRUNC) |
68d6ac6d | 1863 | copied = data_skb->len; |
daa3766e | 1864 | |
1da177e4 LT |
1865 | skb_free_datagram(sk, skb); |
1866 | ||
16b304f3 PS |
1867 | if (nlk->cb_running && |
1868 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
1869 | ret = netlink_dump(sk); |
1870 | if (ret) { | |
ac30ef83 | 1871 | sk->sk_err = -ret; |
b44d211e AV |
1872 | sk->sk_error_report(sk); |
1873 | } | |
1874 | } | |
1da177e4 | 1875 | |
7cc05662 | 1876 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
1877 | out: |
1878 | netlink_rcv_wake(sk); | |
1879 | return err ? : copied; | |
1880 | } | |
1881 | ||
676d2369 | 1882 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 1883 | { |
cd40b7d3 | 1884 | BUG(); |
1da177e4 LT |
1885 | } |
1886 | ||
1887 | /* | |
746fac4d | 1888 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1889 | * complete set of kernel non-blocking support for message |
1890 | * queueing. | |
1891 | */ | |
1892 | ||
1893 | struct sock * | |
9f00d977 PNA |
1894 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
1895 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
1896 | { |
1897 | struct socket *sock; | |
1898 | struct sock *sk; | |
77247bbb | 1899 | struct netlink_sock *nlk; |
5c398dc8 | 1900 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
1901 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
1902 | unsigned int groups; | |
1da177e4 | 1903 | |
fab2caf6 | 1904 | BUG_ON(!nl_table); |
1da177e4 | 1905 | |
6ac552fd | 1906 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1907 | return NULL; |
1908 | ||
1909 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1910 | return NULL; | |
13d3078e EB |
1911 | |
1912 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
1913 | goto out_sock_release_nosk; |
1914 | ||
1915 | sk = sock->sk; | |
4fdb3bb7 | 1916 | |
a31f2d17 | 1917 | if (!cfg || cfg->groups < 32) |
4277a083 | 1918 | groups = 32; |
a31f2d17 PNA |
1919 | else |
1920 | groups = cfg->groups; | |
4277a083 | 1921 | |
5c398dc8 | 1922 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1923 | if (!listeners) |
1924 | goto out_sock_release; | |
1925 | ||
1da177e4 | 1926 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
1927 | if (cfg && cfg->input) |
1928 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 1929 | |
8ea65f4a | 1930 | if (netlink_insert(sk, 0)) |
77247bbb | 1931 | goto out_sock_release; |
4fdb3bb7 | 1932 | |
77247bbb | 1933 | nlk = nlk_sk(sk); |
cc3a572f | 1934 | nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
4fdb3bb7 | 1935 | |
4fdb3bb7 | 1936 | netlink_table_grab(); |
b4b51029 EB |
1937 | if (!nl_table[unit].registered) { |
1938 | nl_table[unit].groups = groups; | |
5c398dc8 | 1939 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1940 | nl_table[unit].cb_mutex = cb_mutex; |
1941 | nl_table[unit].module = module; | |
9785e10a PNA |
1942 | if (cfg) { |
1943 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 1944 | nl_table[unit].unbind = cfg->unbind; |
9785e10a | 1945 | nl_table[unit].flags = cfg->flags; |
da12c90e G |
1946 | if (cfg->compare) |
1947 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 1948 | } |
b4b51029 | 1949 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
1950 | } else { |
1951 | kfree(listeners); | |
869e58f8 | 1952 | nl_table[unit].registered++; |
b4b51029 | 1953 | } |
4fdb3bb7 | 1954 | netlink_table_ungrab(); |
77247bbb PM |
1955 | return sk; |
1956 | ||
4fdb3bb7 | 1957 | out_sock_release: |
4277a083 | 1958 | kfree(listeners); |
9dfbec1f | 1959 | netlink_kernel_release(sk); |
23fe1866 PE |
1960 | return NULL; |
1961 | ||
1962 | out_sock_release_nosk: | |
4fdb3bb7 | 1963 | sock_release(sock); |
77247bbb | 1964 | return NULL; |
1da177e4 | 1965 | } |
9f00d977 | 1966 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
1967 | |
1968 | void | |
1969 | netlink_kernel_release(struct sock *sk) | |
1970 | { | |
13d3078e EB |
1971 | if (sk == NULL || sk->sk_socket == NULL) |
1972 | return; | |
1973 | ||
1974 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
1975 | } |
1976 | EXPORT_SYMBOL(netlink_kernel_release); | |
1977 | ||
d136f1bd | 1978 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 1979 | { |
5c398dc8 | 1980 | struct listeners *new, *old; |
b4ff4f04 | 1981 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
1982 | |
1983 | if (groups < 32) | |
1984 | groups = 32; | |
1985 | ||
b4ff4f04 | 1986 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
1987 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
1988 | if (!new) | |
d136f1bd | 1989 | return -ENOMEM; |
6d772ac5 | 1990 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
1991 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
1992 | rcu_assign_pointer(tbl->listeners, new); | |
1993 | ||
37b6b935 | 1994 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
1995 | } |
1996 | tbl->groups = groups; | |
1997 | ||
d136f1bd JB |
1998 | return 0; |
1999 | } | |
2000 | ||
2001 | /** | |
2002 | * netlink_change_ngroups - change number of multicast groups | |
2003 | * | |
2004 | * This changes the number of multicast groups that are available | |
2005 | * on a certain netlink family. Note that it is not possible to | |
2006 | * change the number of groups to below 32. Also note that it does | |
2007 | * not implicitly call netlink_clear_multicast_users() when the | |
2008 | * number of groups is reduced. | |
2009 | * | |
2010 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2011 | * @groups: The new number of groups. | |
2012 | */ | |
2013 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2014 | { | |
2015 | int err; | |
2016 | ||
2017 | netlink_table_grab(); | |
2018 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2019 | netlink_table_ungrab(); |
d136f1bd | 2020 | |
b4ff4f04 JB |
2021 | return err; |
2022 | } | |
b4ff4f04 | 2023 | |
b8273570 JB |
2024 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2025 | { | |
2026 | struct sock *sk; | |
b8273570 JB |
2027 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2028 | ||
b67bfe0d | 2029 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2030 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2031 | } | |
2032 | ||
a46621a3 | 2033 | struct nlmsghdr * |
15e47304 | 2034 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2035 | { |
2036 | struct nlmsghdr *nlh; | |
573ce260 | 2037 | int size = nlmsg_msg_size(len); |
a46621a3 | 2038 | |
23b45672 | 2039 | nlh = (struct nlmsghdr *)skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2040 | nlh->nlmsg_type = type; |
2041 | nlh->nlmsg_len = size; | |
2042 | nlh->nlmsg_flags = flags; | |
15e47304 | 2043 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2044 | nlh->nlmsg_seq = seq; |
2045 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2046 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2047 | return nlh; |
2048 | } | |
2049 | EXPORT_SYMBOL(__nlmsg_put); | |
2050 | ||
1da177e4 LT |
2051 | /* |
2052 | * It looks a bit ugly. | |
2053 | * It would be better to create kernel thread. | |
2054 | */ | |
2055 | ||
2056 | static int netlink_dump(struct sock *sk) | |
2057 | { | |
2058 | struct netlink_sock *nlk = nlk_sk(sk); | |
2059 | struct netlink_callback *cb; | |
c7ac8679 | 2060 | struct sk_buff *skb = NULL; |
1da177e4 | 2061 | struct nlmsghdr *nlh; |
92964c79 | 2062 | struct module *module; |
bf8b79e4 | 2063 | int len, err = -ENOBUFS; |
db65a3aa | 2064 | int alloc_min_size; |
c7ac8679 | 2065 | int alloc_size; |
1da177e4 | 2066 | |
af65bdfc | 2067 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2068 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2069 | err = -EINVAL; |
2070 | goto errout_skb; | |
1da177e4 LT |
2071 | } |
2072 | ||
d1b4c689 | 2073 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2074 | goto errout_skb; |
9063e21f ED |
2075 | |
2076 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2077 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2078 | * to reduce number of system calls on dump operations, if user | |
2079 | * ever provided a big enough buffer. | |
2080 | */ | |
db65a3aa AR |
2081 | cb = &nlk->cb; |
2082 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2083 | ||
2084 | if (alloc_min_size < nlk->max_recvmsg_len) { | |
2085 | alloc_size = nlk->max_recvmsg_len; | |
c5b0db32 FW |
2086 | skb = alloc_skb(alloc_size, GFP_KERNEL | |
2087 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2088 | } |
db65a3aa AR |
2089 | if (!skb) { |
2090 | alloc_size = alloc_min_size; | |
c5b0db32 | 2091 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2092 | } |
c7ac8679 | 2093 | if (!skb) |
c63d6ea3 | 2094 | goto errout_skb; |
db65a3aa AR |
2095 | |
2096 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2097 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2098 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2099 | * could fit within the allocated skb. skb is typically allocated | |
2100 | * with larger space than required (could be as much as near 2x the | |
2101 | * requested size with align to next power of 2 approach). Allowing | |
2102 | * dump to use the excess space makes it difficult for a user to have a | |
2103 | * reasonable static buffer based on the expected largest dump of a | |
2104 | * single netdev. The outcome is MSG_TRUNC error. | |
2105 | */ | |
d1b4c689 | 2106 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
f9c22888 | 2107 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2108 | |
1da177e4 LT |
2109 | len = cb->dump(skb, cb); |
2110 | ||
2111 | if (len > 0) { | |
af65bdfc | 2112 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2113 | |
2114 | if (sk_filter(sk, skb)) | |
2115 | kfree_skb(skb); | |
4a7e7c2a ED |
2116 | else |
2117 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2118 | return 0; |
2119 | } | |
2120 | ||
bf8b79e4 TG |
2121 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
2122 | if (!nlh) | |
2123 | goto errout_skb; | |
2124 | ||
670dc283 JB |
2125 | nl_dump_check_consistent(cb, nlh); |
2126 | ||
bf8b79e4 TG |
2127 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
2128 | ||
b1153f29 SH |
2129 | if (sk_filter(sk, skb)) |
2130 | kfree_skb(skb); | |
4a7e7c2a ED |
2131 | else |
2132 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2133 | |
a8f74b22 TG |
2134 | if (cb->done) |
2135 | cb->done(cb); | |
1da177e4 | 2136 | |
16b304f3 | 2137 | nlk->cb_running = false; |
92964c79 HX |
2138 | module = cb->module; |
2139 | skb = cb->skb; | |
16b304f3 | 2140 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2141 | module_put(module); |
2142 | consume_skb(skb); | |
1da177e4 | 2143 | return 0; |
1797754e | 2144 | |
bf8b79e4 | 2145 | errout_skb: |
af65bdfc | 2146 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2147 | kfree_skb(skb); |
bf8b79e4 | 2148 | return err; |
1da177e4 LT |
2149 | } |
2150 | ||
6dc878a8 G |
2151 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2152 | const struct nlmsghdr *nlh, | |
2153 | struct netlink_dump_control *control) | |
1da177e4 LT |
2154 | { |
2155 | struct netlink_callback *cb; | |
2156 | struct sock *sk; | |
2157 | struct netlink_sock *nlk; | |
b44d211e | 2158 | int ret; |
1da177e4 | 2159 | |
d1b4c689 | 2160 | atomic_inc(&skb->users); |
f9c22888 | 2161 | |
15e47304 | 2162 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2163 | if (sk == NULL) { |
16b304f3 PS |
2164 | ret = -ECONNREFUSED; |
2165 | goto error_free; | |
1da177e4 | 2166 | } |
6dc878a8 | 2167 | |
16b304f3 | 2168 | nlk = nlk_sk(sk); |
af65bdfc | 2169 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2170 | /* A dump is in progress... */ |
16b304f3 | 2171 | if (nlk->cb_running) { |
6dc878a8 | 2172 | ret = -EBUSY; |
16b304f3 | 2173 | goto error_unlock; |
1da177e4 | 2174 | } |
6dc878a8 | 2175 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2176 | if (!try_module_get(control->module)) { |
6dc878a8 | 2177 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2178 | goto error_unlock; |
6dc878a8 G |
2179 | } |
2180 | ||
16b304f3 PS |
2181 | cb = &nlk->cb; |
2182 | memset(cb, 0, sizeof(*cb)); | |
fc9e50f5 | 2183 | cb->start = control->start; |
16b304f3 PS |
2184 | cb->dump = control->dump; |
2185 | cb->done = control->done; | |
2186 | cb->nlh = nlh; | |
2187 | cb->data = control->data; | |
2188 | cb->module = control->module; | |
2189 | cb->min_dump_alloc = control->min_dump_alloc; | |
2190 | cb->skb = skb; | |
2191 | ||
2192 | nlk->cb_running = true; | |
2193 | ||
af65bdfc | 2194 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2195 | |
fc9e50f5 TH |
2196 | if (cb->start) |
2197 | cb->start(cb); | |
2198 | ||
b44d211e | 2199 | ret = netlink_dump(sk); |
1da177e4 | 2200 | sock_put(sk); |
5c58298c | 2201 | |
b44d211e AV |
2202 | if (ret) |
2203 | return ret; | |
2204 | ||
5c58298c DL |
2205 | /* We successfully started a dump, by returning -EINTR we |
2206 | * signal not to send ACK even if it was requested. | |
2207 | */ | |
2208 | return -EINTR; | |
16b304f3 PS |
2209 | |
2210 | error_unlock: | |
2211 | sock_put(sk); | |
2212 | mutex_unlock(nlk->cb_mutex); | |
2213 | error_free: | |
2214 | kfree_skb(skb); | |
2215 | return ret; | |
1da177e4 | 2216 | } |
6dc878a8 | 2217 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
2218 | |
2219 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
2220 | { | |
2221 | struct sk_buff *skb; | |
2222 | struct nlmsghdr *rep; | |
2223 | struct nlmsgerr *errmsg; | |
339bf98f | 2224 | size_t payload = sizeof(*errmsg); |
0a6a3a23 | 2225 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
1da177e4 | 2226 | |
0a6a3a23 CR |
2227 | /* Error messages get the original request appened, unless the user |
2228 | * requests to cap the error message. | |
2229 | */ | |
2230 | if (!(nlk->flags & NETLINK_F_CAP_ACK) && err) | |
339bf98f | 2231 | payload += nlmsg_len(nlh); |
1da177e4 | 2232 | |
c5b0db32 | 2233 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
2234 | if (!skb) { |
2235 | struct sock *sk; | |
2236 | ||
3b1e0a65 | 2237 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 2238 | in_skb->sk->sk_protocol, |
15e47304 | 2239 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
2240 | if (sk) { |
2241 | sk->sk_err = ENOBUFS; | |
2242 | sk->sk_error_report(sk); | |
2243 | sock_put(sk); | |
2244 | } | |
2245 | return; | |
2246 | } | |
2247 | ||
15e47304 | 2248 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 2249 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 2250 | errmsg = nlmsg_data(rep); |
1da177e4 | 2251 | errmsg->error = err; |
0a6a3a23 | 2252 | memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 2253 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2254 | } |
6ac552fd | 2255 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2256 | |
cd40b7d3 | 2257 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 2258 | struct nlmsghdr *)) |
82ace47a | 2259 | { |
82ace47a TG |
2260 | struct nlmsghdr *nlh; |
2261 | int err; | |
2262 | ||
2263 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2264 | int msglen; |
2265 | ||
b529ccf2 | 2266 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2267 | err = 0; |
82ace47a | 2268 | |
ad8e4b75 | 2269 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2270 | return 0; |
2271 | ||
d35b6856 TG |
2272 | /* Only requests are handled by the kernel */ |
2273 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2274 | goto ack; |
45e7ae7f TG |
2275 | |
2276 | /* Skip control messages */ | |
2277 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2278 | goto ack; |
d35b6856 | 2279 | |
1d00a4eb | 2280 | err = cb(skb, nlh); |
5c58298c DL |
2281 | if (err == -EINTR) |
2282 | goto skip; | |
2283 | ||
2284 | ack: | |
d35b6856 | 2285 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 2286 | netlink_ack(skb, nlh, err); |
82ace47a | 2287 | |
5c58298c | 2288 | skip: |
6ac552fd | 2289 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2290 | if (msglen > skb->len) |
2291 | msglen = skb->len; | |
2292 | skb_pull(skb, msglen); | |
82ace47a TG |
2293 | } |
2294 | ||
2295 | return 0; | |
2296 | } | |
6ac552fd | 2297 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2298 | |
d387f6ad TG |
2299 | /** |
2300 | * nlmsg_notify - send a notification netlink message | |
2301 | * @sk: netlink socket to use | |
2302 | * @skb: notification message | |
15e47304 | 2303 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2304 | * @group: destination multicast group or 0 |
2305 | * @report: 1 to report back, 0 to disable | |
2306 | * @flags: allocation flags | |
2307 | */ | |
15e47304 | 2308 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2309 | unsigned int group, int report, gfp_t flags) |
2310 | { | |
2311 | int err = 0; | |
2312 | ||
2313 | if (group) { | |
15e47304 | 2314 | int exclude_portid = 0; |
d387f6ad TG |
2315 | |
2316 | if (report) { | |
2317 | atomic_inc(&skb->users); | |
15e47304 | 2318 | exclude_portid = portid; |
d387f6ad TG |
2319 | } |
2320 | ||
1ce85fe4 PNA |
2321 | /* errors reported via destination sk->sk_err, but propagate |
2322 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2323 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2324 | } |
2325 | ||
1ce85fe4 PNA |
2326 | if (report) { |
2327 | int err2; | |
2328 | ||
15e47304 | 2329 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2330 | if (!err || err == -ESRCH) |
2331 | err = err2; | |
2332 | } | |
d387f6ad TG |
2333 | |
2334 | return err; | |
2335 | } | |
6ac552fd | 2336 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2337 | |
1da177e4 LT |
2338 | #ifdef CONFIG_PROC_FS |
2339 | struct nl_seq_iter { | |
e372c414 | 2340 | struct seq_net_private p; |
56d28b1e | 2341 | struct rhashtable_iter hti; |
1da177e4 | 2342 | int link; |
1da177e4 LT |
2343 | }; |
2344 | ||
56d28b1e | 2345 | static int netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2346 | { |
56d28b1e | 2347 | int err; |
1da177e4 | 2348 | |
8f6fd83c BC |
2349 | err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti, |
2350 | GFP_KERNEL); | |
56d28b1e HX |
2351 | if (err) { |
2352 | iter->link = MAX_LINKS; | |
2353 | return err; | |
1da177e4 | 2354 | } |
56d28b1e HX |
2355 | |
2356 | err = rhashtable_walk_start(&iter->hti); | |
2357 | return err == -EAGAIN ? 0 : err; | |
1da177e4 LT |
2358 | } |
2359 | ||
56d28b1e | 2360 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2361 | { |
56d28b1e HX |
2362 | rhashtable_walk_stop(&iter->hti); |
2363 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2364 | } |
2365 | ||
56d28b1e | 2366 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2367 | { |
56d28b1e | 2368 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2369 | struct netlink_sock *nlk; |
1da177e4 | 2370 | |
56d28b1e HX |
2371 | do { |
2372 | for (;;) { | |
2373 | int err; | |
1da177e4 | 2374 | |
56d28b1e | 2375 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2376 | |
56d28b1e HX |
2377 | if (IS_ERR(nlk)) { |
2378 | if (PTR_ERR(nlk) == -EAGAIN) | |
2379 | continue; | |
e341694e | 2380 | |
56d28b1e HX |
2381 | return nlk; |
2382 | } | |
1da177e4 | 2383 | |
56d28b1e HX |
2384 | if (nlk) |
2385 | break; | |
1da177e4 | 2386 | |
56d28b1e HX |
2387 | netlink_walk_stop(iter); |
2388 | if (++iter->link >= MAX_LINKS) | |
2389 | return NULL; | |
da12c90e | 2390 | |
56d28b1e HX |
2391 | err = netlink_walk_start(iter); |
2392 | if (err) | |
2393 | return ERR_PTR(err); | |
1da177e4 | 2394 | } |
56d28b1e | 2395 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2396 | |
56d28b1e HX |
2397 | return nlk; |
2398 | } | |
1da177e4 | 2399 | |
56d28b1e HX |
2400 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
2401 | { | |
2402 | struct nl_seq_iter *iter = seq->private; | |
2403 | void *obj = SEQ_START_TOKEN; | |
2404 | loff_t pos; | |
2405 | int err; | |
2406 | ||
2407 | iter->link = 0; | |
2408 | ||
2409 | err = netlink_walk_start(iter); | |
2410 | if (err) | |
2411 | return ERR_PTR(err); | |
2412 | ||
2413 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2414 | obj = __netlink_seq_next(seq); | |
2415 | ||
2416 | return obj; | |
2417 | } | |
2418 | ||
2419 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2420 | { | |
2421 | ++*pos; | |
2422 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2423 | } |
2424 | ||
2425 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2426 | { | |
56d28b1e HX |
2427 | struct nl_seq_iter *iter = seq->private; |
2428 | ||
2429 | if (iter->link >= MAX_LINKS) | |
2430 | return; | |
2431 | ||
2432 | netlink_walk_stop(iter); | |
1da177e4 LT |
2433 | } |
2434 | ||
2435 | ||
2436 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2437 | { | |
658cb354 | 2438 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2439 | seq_puts(seq, |
2440 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2441 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2442 | } else { |
1da177e4 LT |
2443 | struct sock *s = v; |
2444 | struct netlink_sock *nlk = nlk_sk(s); | |
2445 | ||
16b304f3 | 2446 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n", |
1da177e4 LT |
2447 | s, |
2448 | s->sk_protocol, | |
15e47304 | 2449 | nlk->portid, |
513c2500 | 2450 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2451 | sk_rmem_alloc_get(s), |
2452 | sk_wmem_alloc_get(s), | |
16b304f3 | 2453 | nlk->cb_running, |
38938bfe | 2454 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2455 | atomic_read(&s->sk_drops), |
2456 | sock_i_ino(s) | |
1da177e4 LT |
2457 | ); |
2458 | ||
2459 | } | |
2460 | return 0; | |
2461 | } | |
2462 | ||
56b3d975 | 2463 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2464 | .start = netlink_seq_start, |
2465 | .next = netlink_seq_next, | |
2466 | .stop = netlink_seq_stop, | |
2467 | .show = netlink_seq_show, | |
2468 | }; | |
2469 | ||
2470 | ||
2471 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2472 | { | |
e372c414 DL |
2473 | return seq_open_net(inode, file, &netlink_seq_ops, |
2474 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2475 | } |
2476 | ||
da7071d7 | 2477 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2478 | .owner = THIS_MODULE, |
2479 | .open = netlink_seq_open, | |
2480 | .read = seq_read, | |
2481 | .llseek = seq_lseek, | |
e372c414 | 2482 | .release = seq_release_net, |
1da177e4 LT |
2483 | }; |
2484 | ||
2485 | #endif | |
2486 | ||
2487 | int netlink_register_notifier(struct notifier_block *nb) | |
2488 | { | |
e041c683 | 2489 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2490 | } |
6ac552fd | 2491 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2492 | |
2493 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2494 | { | |
e041c683 | 2495 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2496 | } |
6ac552fd | 2497 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2498 | |
90ddc4f0 | 2499 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2500 | .family = PF_NETLINK, |
2501 | .owner = THIS_MODULE, | |
2502 | .release = netlink_release, | |
2503 | .bind = netlink_bind, | |
2504 | .connect = netlink_connect, | |
2505 | .socketpair = sock_no_socketpair, | |
2506 | .accept = sock_no_accept, | |
2507 | .getname = netlink_getname, | |
d1b4c689 | 2508 | .poll = datagram_poll, |
025c6818 | 2509 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2510 | .listen = sock_no_listen, |
2511 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2512 | .setsockopt = netlink_setsockopt, |
2513 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2514 | .sendmsg = netlink_sendmsg, |
2515 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2516 | .mmap = sock_no_mmap, |
1da177e4 LT |
2517 | .sendpage = sock_no_sendpage, |
2518 | }; | |
2519 | ||
ec1b4cf7 | 2520 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2521 | .family = PF_NETLINK, |
2522 | .create = netlink_create, | |
2523 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2524 | }; | |
2525 | ||
4665079c | 2526 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2527 | { |
2528 | #ifdef CONFIG_PROC_FS | |
d4beaa66 | 2529 | if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops)) |
b4b51029 EB |
2530 | return -ENOMEM; |
2531 | #endif | |
2532 | return 0; | |
2533 | } | |
2534 | ||
4665079c | 2535 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2536 | { |
2537 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2538 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2539 | #endif |
2540 | } | |
2541 | ||
b963ea89 DM |
2542 | static void __init netlink_add_usersock_entry(void) |
2543 | { | |
5c398dc8 | 2544 | struct listeners *listeners; |
b963ea89 DM |
2545 | int groups = 32; |
2546 | ||
5c398dc8 | 2547 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2548 | if (!listeners) |
5c398dc8 | 2549 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2550 | |
2551 | netlink_table_grab(); | |
2552 | ||
2553 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2554 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2555 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2556 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2557 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2558 | |
2559 | netlink_table_ungrab(); | |
2560 | } | |
2561 | ||
022cbae6 | 2562 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2563 | .init = netlink_net_init, |
2564 | .exit = netlink_net_exit, | |
2565 | }; | |
2566 | ||
49f7b33e | 2567 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2568 | { |
2569 | const struct netlink_sock *nlk = data; | |
2570 | struct netlink_compare_arg arg; | |
2571 | ||
da314c99 | 2572 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2573 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2574 | } |
2575 | ||
2576 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2577 | .head_offset = offsetof(struct netlink_sock, node), | |
2578 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2579 | .obj_hashfn = netlink_hash, |
2580 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2581 | .automatic_shrinking = true, |
c428ecd1 HX |
2582 | }; |
2583 | ||
1da177e4 LT |
2584 | static int __init netlink_proto_init(void) |
2585 | { | |
1da177e4 | 2586 | int i; |
1da177e4 LT |
2587 | int err = proto_register(&netlink_proto, 0); |
2588 | ||
2589 | if (err != 0) | |
2590 | goto out; | |
2591 | ||
fab25745 | 2592 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 2593 | |
0da974f4 | 2594 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2595 | if (!nl_table) |
2596 | goto panic; | |
1da177e4 | 2597 | |
1da177e4 | 2598 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2599 | if (rhashtable_init(&nl_table[i].hash, |
2600 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2601 | while (--i > 0) |
2602 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2603 | kfree(nl_table); |
fab2caf6 | 2604 | goto panic; |
1da177e4 | 2605 | } |
1da177e4 LT |
2606 | } |
2607 | ||
bcbde0d4 DB |
2608 | INIT_LIST_HEAD(&netlink_tap_all); |
2609 | ||
b963ea89 DM |
2610 | netlink_add_usersock_entry(); |
2611 | ||
1da177e4 | 2612 | sock_register(&netlink_family_ops); |
b4b51029 | 2613 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2614 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2615 | rtnetlink_init(); |
2616 | out: | |
2617 | return err; | |
fab2caf6 AM |
2618 | panic: |
2619 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2620 | } |
2621 | ||
1da177e4 | 2622 | core_initcall(netlink_proto_init); |