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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 | ||
707693c8 | 325 | static void __netlink_sock_destruct(struct sock *sk) |
1da177e4 | 326 | { |
3f660d66 HX |
327 | struct netlink_sock *nlk = nlk_sk(sk); |
328 | ||
16b304f3 | 329 | if (nlk->cb_running) { |
16b304f3 PS |
330 | module_put(nlk->cb.module); |
331 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
332 | } |
333 | ||
1da177e4 LT |
334 | skb_queue_purge(&sk->sk_receive_queue); |
335 | ||
336 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 337 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
338 | return; |
339 | } | |
547b792c IJ |
340 | |
341 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
342 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
343 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
344 | } |
345 | ||
707693c8 HX |
346 | static void netlink_sock_destruct_work(struct work_struct *work) |
347 | { | |
348 | struct netlink_sock *nlk = container_of(work, struct netlink_sock, | |
349 | work); | |
350 | ||
351 | nlk->cb.done(&nlk->cb); | |
352 | __netlink_sock_destruct(&nlk->sk); | |
353 | } | |
354 | ||
355 | static void netlink_sock_destruct(struct sock *sk) | |
356 | { | |
357 | struct netlink_sock *nlk = nlk_sk(sk); | |
358 | ||
359 | if (nlk->cb_running && nlk->cb.done) { | |
360 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); | |
361 | schedule_work(&nlk->work); | |
362 | return; | |
363 | } | |
364 | ||
365 | __netlink_sock_destruct(sk); | |
366 | } | |
367 | ||
6ac552fd PM |
368 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
369 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
370 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
371 | * this, _but_ remember, it adds useless work on UP machines. | |
372 | */ | |
373 | ||
d136f1bd | 374 | void netlink_table_grab(void) |
9a429c49 | 375 | __acquires(nl_table_lock) |
1da177e4 | 376 | { |
d136f1bd JB |
377 | might_sleep(); |
378 | ||
6abd219c | 379 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
380 | |
381 | if (atomic_read(&nl_table_users)) { | |
382 | DECLARE_WAITQUEUE(wait, current); | |
383 | ||
384 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 385 | for (;;) { |
1da177e4 LT |
386 | set_current_state(TASK_UNINTERRUPTIBLE); |
387 | if (atomic_read(&nl_table_users) == 0) | |
388 | break; | |
6abd219c | 389 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 390 | schedule(); |
6abd219c | 391 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
392 | } |
393 | ||
394 | __set_current_state(TASK_RUNNING); | |
395 | remove_wait_queue(&nl_table_wait, &wait); | |
396 | } | |
397 | } | |
398 | ||
d136f1bd | 399 | void netlink_table_ungrab(void) |
9a429c49 | 400 | __releases(nl_table_lock) |
1da177e4 | 401 | { |
6abd219c | 402 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
403 | wake_up(&nl_table_wait); |
404 | } | |
405 | ||
6ac552fd | 406 | static inline void |
1da177e4 LT |
407 | netlink_lock_table(void) |
408 | { | |
409 | /* read_lock() synchronizes us to netlink_table_grab */ | |
410 | ||
411 | read_lock(&nl_table_lock); | |
412 | atomic_inc(&nl_table_users); | |
413 | read_unlock(&nl_table_lock); | |
414 | } | |
415 | ||
6ac552fd | 416 | static inline void |
1da177e4 LT |
417 | netlink_unlock_table(void) |
418 | { | |
419 | if (atomic_dec_and_test(&nl_table_users)) | |
420 | wake_up(&nl_table_wait); | |
421 | } | |
422 | ||
e341694e | 423 | struct netlink_compare_arg |
1da177e4 | 424 | { |
c428ecd1 | 425 | possible_net_t pnet; |
e341694e TG |
426 | u32 portid; |
427 | }; | |
1da177e4 | 428 | |
8f2ddaac HX |
429 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
430 | #define netlink_compare_arg_len \ | |
431 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
432 | |
433 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
434 | const void *ptr) | |
1da177e4 | 435 | { |
c428ecd1 HX |
436 | const struct netlink_compare_arg *x = arg->key; |
437 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 438 | |
da314c99 | 439 | return nlk->portid != x->portid || |
c428ecd1 HX |
440 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
441 | } | |
442 | ||
443 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
444 | struct net *net, u32 portid) | |
445 | { | |
446 | memset(arg, 0, sizeof(*arg)); | |
447 | write_pnet(&arg->pnet, net); | |
448 | arg->portid = portid; | |
1da177e4 LT |
449 | } |
450 | ||
e341694e TG |
451 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
452 | struct net *net) | |
1da177e4 | 453 | { |
c428ecd1 | 454 | struct netlink_compare_arg arg; |
1da177e4 | 455 | |
c428ecd1 HX |
456 | netlink_compare_arg_init(&arg, net, portid); |
457 | return rhashtable_lookup_fast(&table->hash, &arg, | |
458 | netlink_rhashtable_params); | |
1da177e4 LT |
459 | } |
460 | ||
c428ecd1 | 461 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 462 | { |
c428ecd1 | 463 | struct netlink_compare_arg arg; |
c5adde94 | 464 | |
da314c99 | 465 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
466 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
467 | &nlk_sk(sk)->node, | |
468 | netlink_rhashtable_params); | |
c5adde94 YX |
469 | } |
470 | ||
e341694e | 471 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 472 | { |
e341694e TG |
473 | struct netlink_table *table = &nl_table[protocol]; |
474 | struct sock *sk; | |
1da177e4 | 475 | |
e341694e TG |
476 | rcu_read_lock(); |
477 | sk = __netlink_lookup(table, portid, net); | |
478 | if (sk) | |
479 | sock_hold(sk); | |
480 | rcu_read_unlock(); | |
1da177e4 | 481 | |
e341694e | 482 | return sk; |
1da177e4 LT |
483 | } |
484 | ||
90ddc4f0 | 485 | static const struct proto_ops netlink_ops; |
1da177e4 | 486 | |
4277a083 PM |
487 | static void |
488 | netlink_update_listeners(struct sock *sk) | |
489 | { | |
490 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
491 | unsigned long mask; |
492 | unsigned int i; | |
6d772ac5 ED |
493 | struct listeners *listeners; |
494 | ||
495 | listeners = nl_deref_protected(tbl->listeners); | |
496 | if (!listeners) | |
497 | return; | |
4277a083 | 498 | |
b4ff4f04 | 499 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 500 | mask = 0; |
b67bfe0d | 501 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
502 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
503 | mask |= nlk_sk(sk)->groups[i]; | |
504 | } | |
6d772ac5 | 505 | listeners->masks[i] = mask; |
4277a083 PM |
506 | } |
507 | /* this function is only called with the netlink table "grabbed", which | |
508 | * makes sure updates are visible before bind or setsockopt return. */ | |
509 | } | |
510 | ||
8ea65f4a | 511 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 512 | { |
da12c90e | 513 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 514 | int err; |
1da177e4 | 515 | |
c5adde94 | 516 | lock_sock(sk); |
1da177e4 | 517 | |
da314c99 HX |
518 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
519 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
520 | goto err; |
521 | ||
522 | err = -ENOMEM; | |
97defe1e TG |
523 | if (BITS_PER_LONG > 32 && |
524 | unlikely(atomic_read(&table->hash.nelems) >= UINT_MAX)) | |
1da177e4 LT |
525 | goto err; |
526 | ||
da314c99 | 527 | nlk_sk(sk)->portid = portid; |
e341694e | 528 | sock_hold(sk); |
919d9db9 | 529 | |
c428ecd1 HX |
530 | err = __netlink_insert(table, sk); |
531 | if (err) { | |
4e7c1330 DB |
532 | /* In case the hashtable backend returns with -EBUSY |
533 | * from here, it must not escape to the caller. | |
534 | */ | |
535 | if (unlikely(err == -EBUSY)) | |
536 | err = -EOVERFLOW; | |
c428ecd1 HX |
537 | if (err == -EEXIST) |
538 | err = -EADDRINUSE; | |
c5adde94 | 539 | sock_put(sk); |
1f770c0a | 540 | goto err; |
919d9db9 HX |
541 | } |
542 | ||
da314c99 HX |
543 | /* We need to ensure that the socket is hashed and visible. */ |
544 | smp_wmb(); | |
545 | nlk_sk(sk)->bound = portid; | |
1f770c0a | 546 | |
1da177e4 | 547 | err: |
c5adde94 | 548 | release_sock(sk); |
1da177e4 LT |
549 | return err; |
550 | } | |
551 | ||
552 | static void netlink_remove(struct sock *sk) | |
553 | { | |
e341694e TG |
554 | struct netlink_table *table; |
555 | ||
e341694e | 556 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
557 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
558 | netlink_rhashtable_params)) { | |
e341694e TG |
559 | WARN_ON(atomic_read(&sk->sk_refcnt) == 1); |
560 | __sock_put(sk); | |
561 | } | |
e341694e | 562 | |
1da177e4 | 563 | netlink_table_grab(); |
b10dcb3b | 564 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 565 | __sk_del_bind_node(sk); |
b10dcb3b JB |
566 | netlink_update_listeners(sk); |
567 | } | |
ee1c2442 JB |
568 | if (sk->sk_protocol == NETLINK_GENERIC) |
569 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
570 | netlink_table_ungrab(); |
571 | } | |
572 | ||
573 | static struct proto netlink_proto = { | |
574 | .name = "NETLINK", | |
575 | .owner = THIS_MODULE, | |
576 | .obj_size = sizeof(struct netlink_sock), | |
577 | }; | |
578 | ||
1b8d7ae4 | 579 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
580 | struct mutex *cb_mutex, int protocol, |
581 | int kern) | |
1da177e4 LT |
582 | { |
583 | struct sock *sk; | |
584 | struct netlink_sock *nlk; | |
ab33a171 PM |
585 | |
586 | sock->ops = &netlink_ops; | |
587 | ||
11aa9c28 | 588 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
589 | if (!sk) |
590 | return -ENOMEM; | |
591 | ||
592 | sock_init_data(sock, sk); | |
593 | ||
594 | nlk = nlk_sk(sk); | |
658cb354 | 595 | if (cb_mutex) { |
ffa4d721 | 596 | nlk->cb_mutex = cb_mutex; |
658cb354 | 597 | } else { |
ffa4d721 PM |
598 | nlk->cb_mutex = &nlk->cb_def_mutex; |
599 | mutex_init(nlk->cb_mutex); | |
600 | } | |
ab33a171 PM |
601 | init_waitqueue_head(&nlk->wait); |
602 | ||
603 | sk->sk_destruct = netlink_sock_destruct; | |
604 | sk->sk_protocol = protocol; | |
605 | return 0; | |
606 | } | |
607 | ||
3f378b68 EP |
608 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
609 | int kern) | |
ab33a171 PM |
610 | { |
611 | struct module *module = NULL; | |
af65bdfc | 612 | struct mutex *cb_mutex; |
f7fa9b10 | 613 | struct netlink_sock *nlk; |
023e2cfa JB |
614 | int (*bind)(struct net *net, int group); |
615 | void (*unbind)(struct net *net, int group); | |
ab33a171 | 616 | int err = 0; |
1da177e4 LT |
617 | |
618 | sock->state = SS_UNCONNECTED; | |
619 | ||
620 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
621 | return -ESOCKTNOSUPPORT; | |
622 | ||
6ac552fd | 623 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
624 | return -EPROTONOSUPPORT; |
625 | ||
77247bbb | 626 | netlink_lock_table(); |
95a5afca | 627 | #ifdef CONFIG_MODULES |
ab33a171 | 628 | if (!nl_table[protocol].registered) { |
77247bbb | 629 | netlink_unlock_table(); |
4fdb3bb7 | 630 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 631 | netlink_lock_table(); |
4fdb3bb7 | 632 | } |
ab33a171 PM |
633 | #endif |
634 | if (nl_table[protocol].registered && | |
635 | try_module_get(nl_table[protocol].module)) | |
636 | module = nl_table[protocol].module; | |
974c37e9 AD |
637 | else |
638 | err = -EPROTONOSUPPORT; | |
af65bdfc | 639 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 640 | bind = nl_table[protocol].bind; |
4f520900 | 641 | unbind = nl_table[protocol].unbind; |
77247bbb | 642 | netlink_unlock_table(); |
4fdb3bb7 | 643 | |
974c37e9 AD |
644 | if (err < 0) |
645 | goto out; | |
646 | ||
11aa9c28 | 647 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 648 | if (err < 0) |
f7fa9b10 PM |
649 | goto out_module; |
650 | ||
6f756a8c | 651 | local_bh_disable(); |
c1fd3b94 | 652 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
653 | local_bh_enable(); |
654 | ||
f7fa9b10 | 655 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 656 | nlk->module = module; |
03292745 | 657 | nlk->netlink_bind = bind; |
4f520900 | 658 | nlk->netlink_unbind = unbind; |
ab33a171 PM |
659 | out: |
660 | return err; | |
1da177e4 | 661 | |
ab33a171 PM |
662 | out_module: |
663 | module_put(module); | |
664 | goto out; | |
1da177e4 LT |
665 | } |
666 | ||
21e4902a TG |
667 | static void deferred_put_nlk_sk(struct rcu_head *head) |
668 | { | |
669 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
670 | ||
671 | sock_put(&nlk->sk); | |
672 | } | |
673 | ||
1da177e4 LT |
674 | static int netlink_release(struct socket *sock) |
675 | { | |
676 | struct sock *sk = sock->sk; | |
677 | struct netlink_sock *nlk; | |
678 | ||
679 | if (!sk) | |
680 | return 0; | |
681 | ||
682 | netlink_remove(sk); | |
ac57b3a9 | 683 | sock_orphan(sk); |
1da177e4 LT |
684 | nlk = nlk_sk(sk); |
685 | ||
3f660d66 HX |
686 | /* |
687 | * OK. Socket is unlinked, any packets that arrive now | |
688 | * will be purged. | |
689 | */ | |
1da177e4 | 690 | |
ee1c2442 JB |
691 | /* must not acquire netlink_table_lock in any way again before unbind |
692 | * and notifying genetlink is done as otherwise it might deadlock | |
693 | */ | |
694 | if (nlk->netlink_unbind) { | |
695 | int i; | |
696 | ||
697 | for (i = 0; i < nlk->ngroups; i++) | |
698 | if (test_bit(i, nlk->groups)) | |
699 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
700 | } | |
701 | if (sk->sk_protocol == NETLINK_GENERIC && | |
702 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
703 | wake_up(&genl_sk_destructing_waitq); | |
704 | ||
1da177e4 LT |
705 | sock->sk = NULL; |
706 | wake_up_interruptible_all(&nlk->wait); | |
707 | ||
708 | skb_queue_purge(&sk->sk_write_queue); | |
709 | ||
e2726020 | 710 | if (nlk->portid && nlk->bound) { |
1da177e4 | 711 | struct netlink_notify n = { |
3b1e0a65 | 712 | .net = sock_net(sk), |
1da177e4 | 713 | .protocol = sk->sk_protocol, |
15e47304 | 714 | .portid = nlk->portid, |
1da177e4 | 715 | }; |
e041c683 AS |
716 | atomic_notifier_call_chain(&netlink_chain, |
717 | NETLINK_URELEASE, &n); | |
746fac4d | 718 | } |
4fdb3bb7 | 719 | |
5e7c001c | 720 | module_put(nlk->module); |
4fdb3bb7 | 721 | |
aed81560 | 722 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 723 | netlink_table_grab(); |
869e58f8 DL |
724 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
725 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
726 | struct listeners *old; |
727 | ||
728 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
729 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
730 | kfree_rcu(old, rcu); | |
869e58f8 | 731 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 732 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 733 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 734 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
735 | nl_table[sk->sk_protocol].registered = 0; |
736 | } | |
b10dcb3b | 737 | netlink_table_ungrab(); |
658cb354 | 738 | } |
77247bbb | 739 | |
f7fa9b10 PM |
740 | kfree(nlk->groups); |
741 | nlk->groups = NULL; | |
742 | ||
3755810c | 743 | local_bh_disable(); |
c1fd3b94 | 744 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 745 | local_bh_enable(); |
21e4902a | 746 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
747 | return 0; |
748 | } | |
749 | ||
750 | static int netlink_autobind(struct socket *sock) | |
751 | { | |
752 | struct sock *sk = sock->sk; | |
3b1e0a65 | 753 | struct net *net = sock_net(sk); |
da12c90e | 754 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 755 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 756 | int err; |
b9fbe709 HX |
757 | s32 rover = -4096; |
758 | bool ok; | |
1da177e4 LT |
759 | |
760 | retry: | |
761 | cond_resched(); | |
e341694e | 762 | rcu_read_lock(); |
b9fbe709 HX |
763 | ok = !__netlink_lookup(table, portid, net); |
764 | rcu_read_unlock(); | |
765 | if (!ok) { | |
e341694e | 766 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
767 | if (rover == -4096) |
768 | /* rover will be in range [S32_MIN, -4097] */ | |
769 | rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); | |
770 | else if (rover >= -4096) | |
e341694e | 771 | rover = -4097; |
b9fbe709 | 772 | portid = rover--; |
e341694e | 773 | goto retry; |
1da177e4 | 774 | } |
1da177e4 | 775 | |
8ea65f4a | 776 | err = netlink_insert(sk, portid); |
1da177e4 LT |
777 | if (err == -EADDRINUSE) |
778 | goto retry; | |
d470e3b4 DM |
779 | |
780 | /* If 2 threads race to autobind, that is fine. */ | |
781 | if (err == -EBUSY) | |
782 | err = 0; | |
783 | ||
784 | return err; | |
1da177e4 LT |
785 | } |
786 | ||
aa4cf945 EB |
787 | /** |
788 | * __netlink_ns_capable - General netlink message capability test | |
789 | * @nsp: NETLINK_CB of the 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 netlink_skb_parms *nsp, | |
798 | struct user_namespace *user_ns, int cap) | |
799 | { | |
2d7a85f4 EB |
800 | return ((nsp->flags & NETLINK_SKB_DST) || |
801 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
802 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
803 | } |
804 | EXPORT_SYMBOL(__netlink_ns_capable); | |
805 | ||
806 | /** | |
807 | * netlink_ns_capable - General netlink message capability test | |
808 | * @skb: socket buffer holding a netlink command from userspace | |
809 | * @user_ns: The user namespace of the capability to use | |
810 | * @cap: The capability to use | |
811 | * | |
812 | * Test to see if the opener of the socket we received the message | |
813 | * from had when the netlink socket was created and the sender of the | |
814 | * message has has the capability @cap in the user namespace @user_ns. | |
815 | */ | |
816 | bool netlink_ns_capable(const struct sk_buff *skb, | |
817 | struct user_namespace *user_ns, int cap) | |
818 | { | |
819 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
820 | } | |
821 | EXPORT_SYMBOL(netlink_ns_capable); | |
822 | ||
823 | /** | |
824 | * netlink_capable - Netlink global message capability test | |
825 | * @skb: socket buffer holding a netlink command from userspace | |
826 | * @cap: The capability to use | |
827 | * | |
828 | * Test to see if the opener of the socket we received the message | |
829 | * from had when the netlink socket was created and the sender of the | |
830 | * message has has the capability @cap in all user namespaces. | |
831 | */ | |
832 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
833 | { | |
834 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
835 | } | |
836 | EXPORT_SYMBOL(netlink_capable); | |
837 | ||
838 | /** | |
839 | * netlink_net_capable - Netlink network namespace message capability test | |
840 | * @skb: socket buffer holding a netlink command from userspace | |
841 | * @cap: The capability to use | |
842 | * | |
843 | * Test to see if the opener of the socket we received the message | |
844 | * from had when the netlink socket was created and the sender of the | |
845 | * message has has the capability @cap over the network namespace of | |
846 | * the socket we received the message from. | |
847 | */ | |
848 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
849 | { | |
850 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
851 | } | |
852 | EXPORT_SYMBOL(netlink_net_capable); | |
853 | ||
5187cd05 | 854 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 855 | { |
9785e10a | 856 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 857 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 858 | } |
1da177e4 | 859 | |
f7fa9b10 PM |
860 | static void |
861 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
862 | { | |
863 | struct netlink_sock *nlk = nlk_sk(sk); | |
864 | ||
865 | if (nlk->subscriptions && !subscriptions) | |
866 | __sk_del_bind_node(sk); | |
867 | else if (!nlk->subscriptions && subscriptions) | |
868 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
869 | nlk->subscriptions = subscriptions; | |
870 | } | |
871 | ||
b4ff4f04 | 872 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
873 | { |
874 | struct netlink_sock *nlk = nlk_sk(sk); | |
875 | unsigned int groups; | |
b4ff4f04 | 876 | unsigned long *new_groups; |
513c2500 PM |
877 | int err = 0; |
878 | ||
b4ff4f04 JB |
879 | netlink_table_grab(); |
880 | ||
513c2500 | 881 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 882 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 883 | err = -ENOENT; |
b4ff4f04 JB |
884 | goto out_unlock; |
885 | } | |
513c2500 | 886 | |
b4ff4f04 JB |
887 | if (nlk->ngroups >= groups) |
888 | goto out_unlock; | |
513c2500 | 889 | |
b4ff4f04 JB |
890 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
891 | if (new_groups == NULL) { | |
892 | err = -ENOMEM; | |
893 | goto out_unlock; | |
894 | } | |
6ac552fd | 895 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
896 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
897 | ||
898 | nlk->groups = new_groups; | |
513c2500 | 899 | nlk->ngroups = groups; |
b4ff4f04 JB |
900 | out_unlock: |
901 | netlink_table_ungrab(); | |
902 | return err; | |
513c2500 PM |
903 | } |
904 | ||
02c81ab9 | 905 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 906 | struct sock *sk) |
4f520900 | 907 | { |
023e2cfa | 908 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
909 | int undo; |
910 | ||
911 | if (!nlk->netlink_unbind) | |
912 | return; | |
913 | ||
914 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 915 | if (test_bit(undo, &groups)) |
8b7c36d8 | 916 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
917 | } |
918 | ||
6ac552fd PM |
919 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
920 | int addr_len) | |
1da177e4 LT |
921 | { |
922 | struct sock *sk = sock->sk; | |
3b1e0a65 | 923 | struct net *net = sock_net(sk); |
1da177e4 LT |
924 | struct netlink_sock *nlk = nlk_sk(sk); |
925 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
926 | int err; | |
4f520900 | 927 | long unsigned int groups = nladdr->nl_groups; |
da314c99 | 928 | bool bound; |
746fac4d | 929 | |
4e4b5376 HFS |
930 | if (addr_len < sizeof(struct sockaddr_nl)) |
931 | return -EINVAL; | |
932 | ||
1da177e4 LT |
933 | if (nladdr->nl_family != AF_NETLINK) |
934 | return -EINVAL; | |
935 | ||
936 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 937 | if (groups) { |
5187cd05 | 938 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 939 | return -EPERM; |
b4ff4f04 JB |
940 | err = netlink_realloc_groups(sk); |
941 | if (err) | |
942 | return err; | |
513c2500 | 943 | } |
1da177e4 | 944 | |
da314c99 HX |
945 | bound = nlk->bound; |
946 | if (bound) { | |
947 | /* Ensure nlk->portid is up-to-date. */ | |
948 | smp_rmb(); | |
949 | ||
15e47304 | 950 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 951 | return -EINVAL; |
da314c99 | 952 | } |
4f520900 RGB |
953 | |
954 | if (nlk->netlink_bind && groups) { | |
955 | int group; | |
956 | ||
957 | for (group = 0; group < nlk->ngroups; group++) { | |
958 | if (!test_bit(group, &groups)) | |
959 | continue; | |
8b7c36d8 | 960 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
961 | if (!err) |
962 | continue; | |
023e2cfa | 963 | netlink_undo_bind(group, groups, sk); |
4f520900 RGB |
964 | return err; |
965 | } | |
966 | } | |
967 | ||
da314c99 HX |
968 | /* No need for barriers here as we return to user-space without |
969 | * using any of the bound attributes. | |
970 | */ | |
971 | if (!bound) { | |
1da177e4 | 972 | err = nladdr->nl_pid ? |
8ea65f4a | 973 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 974 | netlink_autobind(sock); |
4f520900 | 975 | if (err) { |
023e2cfa | 976 | netlink_undo_bind(nlk->ngroups, groups, sk); |
1da177e4 | 977 | return err; |
4f520900 | 978 | } |
1da177e4 LT |
979 | } |
980 | ||
4f520900 | 981 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
982 | return 0; |
983 | ||
984 | netlink_table_grab(); | |
f7fa9b10 | 985 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 986 | hweight32(groups) - |
746fac4d | 987 | hweight32(nlk->groups[0])); |
4f520900 | 988 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 989 | netlink_update_listeners(sk); |
1da177e4 LT |
990 | netlink_table_ungrab(); |
991 | ||
992 | return 0; | |
993 | } | |
994 | ||
995 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
996 | int alen, int flags) | |
997 | { | |
998 | int err = 0; | |
999 | struct sock *sk = sock->sk; | |
1000 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1001 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1002 | |
6503d961 CG |
1003 | if (alen < sizeof(addr->sa_family)) |
1004 | return -EINVAL; | |
1005 | ||
1da177e4 LT |
1006 | if (addr->sa_family == AF_UNSPEC) { |
1007 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 1008 | nlk->dst_portid = 0; |
d629b836 | 1009 | nlk->dst_group = 0; |
1da177e4 LT |
1010 | return 0; |
1011 | } | |
1012 | if (addr->sa_family != AF_NETLINK) | |
1013 | return -EINVAL; | |
1014 | ||
46833a86 | 1015 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 1016 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1017 | return -EPERM; |
1018 | ||
da314c99 HX |
1019 | /* No need for barriers here as we return to user-space without |
1020 | * using any of the bound attributes. | |
1021 | */ | |
1022 | if (!nlk->bound) | |
1da177e4 LT |
1023 | err = netlink_autobind(sock); |
1024 | ||
1025 | if (err == 0) { | |
1026 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1027 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1028 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1029 | } |
1030 | ||
1031 | return err; | |
1032 | } | |
1033 | ||
6ac552fd PM |
1034 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
1035 | int *addr_len, int peer) | |
1da177e4 LT |
1036 | { |
1037 | struct sock *sk = sock->sk; | |
1038 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1039 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1040 | |
1da177e4 LT |
1041 | nladdr->nl_family = AF_NETLINK; |
1042 | nladdr->nl_pad = 0; | |
1043 | *addr_len = sizeof(*nladdr); | |
1044 | ||
1045 | if (peer) { | |
15e47304 | 1046 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1047 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1048 | } else { |
15e47304 | 1049 | nladdr->nl_pid = nlk->portid; |
513c2500 | 1050 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
1051 | } |
1052 | return 0; | |
1053 | } | |
1054 | ||
025c6818 DD |
1055 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1056 | unsigned long arg) | |
1057 | { | |
1058 | /* try to hand this ioctl down to the NIC drivers. | |
1059 | */ | |
1060 | return -ENOIOCTLCMD; | |
1061 | } | |
1062 | ||
15e47304 | 1063 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1064 | { |
1da177e4 LT |
1065 | struct sock *sock; |
1066 | struct netlink_sock *nlk; | |
1067 | ||
15e47304 | 1068 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1069 | if (!sock) |
1070 | return ERR_PTR(-ECONNREFUSED); | |
1071 | ||
1072 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1073 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1074 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1075 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1076 | sock_put(sock); |
1077 | return ERR_PTR(-ECONNREFUSED); | |
1078 | } | |
1079 | return sock; | |
1080 | } | |
1081 | ||
1082 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1083 | { | |
496ad9aa | 1084 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1085 | struct sock *sock; |
1086 | ||
1087 | if (!S_ISSOCK(inode->i_mode)) | |
1088 | return ERR_PTR(-ENOTSOCK); | |
1089 | ||
1090 | sock = SOCKET_I(inode)->sk; | |
1091 | if (sock->sk_family != AF_NETLINK) | |
1092 | return ERR_PTR(-EINVAL); | |
1093 | ||
1094 | sock_hold(sock); | |
1095 | return sock; | |
1096 | } | |
1097 | ||
3a36515f PN |
1098 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1099 | int broadcast) | |
c05cdb1b PNA |
1100 | { |
1101 | struct sk_buff *skb; | |
1102 | void *data; | |
1103 | ||
3a36515f | 1104 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1105 | return alloc_skb(size, GFP_KERNEL); |
1106 | ||
3a36515f PN |
1107 | size = SKB_DATA_ALIGN(size) + |
1108 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1109 | |
1110 | data = vmalloc(size); | |
1111 | if (data == NULL) | |
3a36515f | 1112 | return NULL; |
c05cdb1b | 1113 | |
2ea2f62c | 1114 | skb = __build_skb(data, size); |
3a36515f PN |
1115 | if (skb == NULL) |
1116 | vfree(data); | |
2ea2f62c | 1117 | else |
3a36515f | 1118 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1119 | |
1120 | return skb; | |
c05cdb1b PNA |
1121 | } |
1122 | ||
1da177e4 LT |
1123 | /* |
1124 | * Attach a skb to a netlink socket. | |
1125 | * The caller must hold a reference to the destination socket. On error, the | |
1126 | * reference is dropped. The skb is not send to the destination, just all | |
1127 | * all error checks are performed and memory in the queue is reserved. | |
1128 | * Return values: | |
1129 | * < 0: error. skb freed, reference to sock dropped. | |
1130 | * 0: continue | |
1131 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1132 | */ | |
9457afee | 1133 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1134 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1135 | { |
1136 | struct netlink_sock *nlk; | |
1137 | ||
1138 | nlk = nlk_sk(sk); | |
1139 | ||
5fd96123 | 1140 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1141 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1142 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1143 | if (!*timeo) { |
aed81560 | 1144 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1145 | netlink_overrun(sk); |
1146 | sock_put(sk); | |
1147 | kfree_skb(skb); | |
1148 | return -EAGAIN; | |
1149 | } | |
1150 | ||
1151 | __set_current_state(TASK_INTERRUPTIBLE); | |
1152 | add_wait_queue(&nlk->wait, &wait); | |
1153 | ||
1154 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1155 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1156 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1157 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1158 | |
1159 | __set_current_state(TASK_RUNNING); | |
1160 | remove_wait_queue(&nlk->wait, &wait); | |
1161 | sock_put(sk); | |
1162 | ||
1163 | if (signal_pending(current)) { | |
1164 | kfree_skb(skb); | |
c3d8d1e3 | 1165 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1166 | } |
1167 | return 1; | |
1168 | } | |
cf0a018a | 1169 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1170 | return 0; |
1171 | } | |
1172 | ||
4a7e7c2a | 1173 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1174 | { |
1da177e4 LT |
1175 | int len = skb->len; |
1176 | ||
bcbde0d4 DB |
1177 | netlink_deliver_tap(skb); |
1178 | ||
d1b4c689 | 1179 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1180 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1181 | return len; |
1182 | } | |
1183 | ||
1184 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1185 | { | |
1186 | int len = __netlink_sendskb(sk, skb); | |
1187 | ||
1da177e4 LT |
1188 | sock_put(sk); |
1189 | return len; | |
1190 | } | |
1191 | ||
1192 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1193 | { | |
1194 | kfree_skb(skb); | |
1195 | sock_put(sk); | |
1196 | } | |
1197 | ||
b57ef81f | 1198 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1199 | { |
1200 | int delta; | |
1201 | ||
1298ca46 | 1202 | WARN_ON(skb->sk != NULL); |
4305b541 | 1203 | delta = skb->end - skb->tail; |
c05cdb1b | 1204 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1205 | return skb; |
1206 | ||
1207 | if (skb_shared(skb)) { | |
1208 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1209 | if (!nskb) | |
1210 | return skb; | |
8460c00f | 1211 | consume_skb(skb); |
1da177e4 LT |
1212 | skb = nskb; |
1213 | } | |
1214 | ||
1215 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
1216 | skb->truesize -= delta; | |
1217 | ||
1218 | return skb; | |
1219 | } | |
1220 | ||
3fbc2905 EB |
1221 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1222 | struct sock *ssk) | |
cd40b7d3 DL |
1223 | { |
1224 | int ret; | |
1225 | struct netlink_sock *nlk = nlk_sk(sk); | |
1226 | ||
1227 | ret = -ECONNREFUSED; | |
1228 | if (nlk->netlink_rcv != NULL) { | |
1229 | ret = skb->len; | |
cf0a018a | 1230 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1231 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1232 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1233 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1234 | consume_skb(skb); |
1235 | } else { | |
1236 | kfree_skb(skb); | |
cd40b7d3 | 1237 | } |
cd40b7d3 DL |
1238 | sock_put(sk); |
1239 | return ret; | |
1240 | } | |
1241 | ||
1242 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1243 | u32 portid, int nonblock) |
1da177e4 LT |
1244 | { |
1245 | struct sock *sk; | |
1246 | int err; | |
1247 | long timeo; | |
1248 | ||
1249 | skb = netlink_trim(skb, gfp_any()); | |
1250 | ||
1251 | timeo = sock_sndtimeo(ssk, nonblock); | |
1252 | retry: | |
15e47304 | 1253 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1254 | if (IS_ERR(sk)) { |
1255 | kfree_skb(skb); | |
1256 | return PTR_ERR(sk); | |
1257 | } | |
cd40b7d3 | 1258 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1259 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1260 | |
b1153f29 | 1261 | if (sk_filter(sk, skb)) { |
84874607 | 1262 | err = skb->len; |
b1153f29 SH |
1263 | kfree_skb(skb); |
1264 | sock_put(sk); | |
1265 | return err; | |
1266 | } | |
1267 | ||
9457afee | 1268 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1269 | if (err == 1) |
1270 | goto retry; | |
1271 | if (err) | |
1272 | return err; | |
1273 | ||
7ee015e0 | 1274 | return netlink_sendskb(sk, skb); |
1da177e4 | 1275 | } |
6ac552fd | 1276 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1277 | |
4277a083 PM |
1278 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1279 | { | |
1280 | int res = 0; | |
5c398dc8 | 1281 | struct listeners *listeners; |
4277a083 | 1282 | |
aed81560 | 1283 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1284 | |
1285 | rcu_read_lock(); | |
1286 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1287 | ||
6d772ac5 | 1288 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1289 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1290 | |
1291 | rcu_read_unlock(); | |
1292 | ||
4277a083 PM |
1293 | return res; |
1294 | } | |
1295 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1296 | ||
b57ef81f | 1297 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1298 | { |
1299 | struct netlink_sock *nlk = nlk_sk(sk); | |
1300 | ||
1301 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1302 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1303 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1304 | __netlink_sendskb(sk, skb); |
2c645800 | 1305 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1306 | } |
1307 | return -1; | |
1308 | } | |
1309 | ||
1310 | struct netlink_broadcast_data { | |
1311 | struct sock *exclude_sk; | |
b4b51029 | 1312 | struct net *net; |
15e47304 | 1313 | u32 portid; |
1da177e4 LT |
1314 | u32 group; |
1315 | int failure; | |
ff491a73 | 1316 | int delivery_failure; |
1da177e4 LT |
1317 | int congested; |
1318 | int delivered; | |
7d877f3b | 1319 | gfp_t allocation; |
1da177e4 | 1320 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1321 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1322 | void *tx_data; | |
1da177e4 LT |
1323 | }; |
1324 | ||
46c9521f RR |
1325 | static void do_one_broadcast(struct sock *sk, |
1326 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1327 | { |
1328 | struct netlink_sock *nlk = nlk_sk(sk); | |
1329 | int val; | |
1330 | ||
1331 | if (p->exclude_sk == sk) | |
46c9521f | 1332 | return; |
1da177e4 | 1333 | |
15e47304 | 1334 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1335 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1336 | return; |
1da177e4 | 1337 | |
59324cf3 ND |
1338 | if (!net_eq(sock_net(sk), p->net)) { |
1339 | if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) | |
1340 | return; | |
1341 | ||
1342 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1343 | return; | |
1344 | ||
1345 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1346 | CAP_NET_BROADCAST)) | |
1347 | return; | |
1348 | } | |
b4b51029 | 1349 | |
1da177e4 LT |
1350 | if (p->failure) { |
1351 | netlink_overrun(sk); | |
46c9521f | 1352 | return; |
1da177e4 LT |
1353 | } |
1354 | ||
1355 | sock_hold(sk); | |
1356 | if (p->skb2 == NULL) { | |
68acc024 | 1357 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1358 | p->skb2 = skb_clone(p->skb, p->allocation); |
1359 | } else { | |
68acc024 TC |
1360 | p->skb2 = skb_get(p->skb); |
1361 | /* | |
1362 | * skb ownership may have been set when | |
1363 | * delivered to a previous socket. | |
1364 | */ | |
1365 | skb_orphan(p->skb2); | |
1da177e4 LT |
1366 | } |
1367 | } | |
1368 | if (p->skb2 == NULL) { | |
1369 | netlink_overrun(sk); | |
1370 | /* Clone failed. Notify ALL listeners. */ | |
1371 | p->failure = 1; | |
cc3a572f | 1372 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1373 | p->delivery_failure = 1; |
59324cf3 ND |
1374 | goto out; |
1375 | } | |
1376 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
910a7e90 EB |
1377 | kfree_skb(p->skb2); |
1378 | p->skb2 = NULL; | |
59324cf3 ND |
1379 | goto out; |
1380 | } | |
1381 | if (sk_filter(sk, p->skb2)) { | |
b1153f29 SH |
1382 | kfree_skb(p->skb2); |
1383 | p->skb2 = NULL; | |
59324cf3 ND |
1384 | goto out; |
1385 | } | |
1386 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
1387 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
1388 | val = netlink_broadcast_deliver(sk, p->skb2); | |
1389 | if (val < 0) { | |
1da177e4 | 1390 | netlink_overrun(sk); |
cc3a572f | 1391 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1392 | p->delivery_failure = 1; |
1da177e4 LT |
1393 | } else { |
1394 | p->congested |= val; | |
1395 | p->delivered = 1; | |
1396 | p->skb2 = NULL; | |
1397 | } | |
59324cf3 | 1398 | out: |
1da177e4 | 1399 | sock_put(sk); |
1da177e4 LT |
1400 | } |
1401 | ||
15e47304 | 1402 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1403 | u32 group, gfp_t allocation, |
1404 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1405 | void *filter_data) | |
1da177e4 | 1406 | { |
3b1e0a65 | 1407 | struct net *net = sock_net(ssk); |
1da177e4 | 1408 | struct netlink_broadcast_data info; |
1da177e4 LT |
1409 | struct sock *sk; |
1410 | ||
1411 | skb = netlink_trim(skb, allocation); | |
1412 | ||
1413 | info.exclude_sk = ssk; | |
b4b51029 | 1414 | info.net = net; |
15e47304 | 1415 | info.portid = portid; |
1da177e4 LT |
1416 | info.group = group; |
1417 | info.failure = 0; | |
ff491a73 | 1418 | info.delivery_failure = 0; |
1da177e4 LT |
1419 | info.congested = 0; |
1420 | info.delivered = 0; | |
1421 | info.allocation = allocation; | |
1422 | info.skb = skb; | |
1423 | info.skb2 = NULL; | |
910a7e90 EB |
1424 | info.tx_filter = filter; |
1425 | info.tx_data = filter_data; | |
1da177e4 LT |
1426 | |
1427 | /* While we sleep in clone, do not allow to change socket list */ | |
1428 | ||
1429 | netlink_lock_table(); | |
1430 | ||
b67bfe0d | 1431 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1432 | do_one_broadcast(sk, &info); |
1433 | ||
70d4bf6d | 1434 | consume_skb(skb); |
aa1c6a6f | 1435 | |
1da177e4 LT |
1436 | netlink_unlock_table(); |
1437 | ||
70d4bf6d NH |
1438 | if (info.delivery_failure) { |
1439 | kfree_skb(info.skb2); | |
ff491a73 | 1440 | return -ENOBUFS; |
658cb354 ED |
1441 | } |
1442 | consume_skb(info.skb2); | |
ff491a73 | 1443 | |
1da177e4 | 1444 | if (info.delivered) { |
d0164adc | 1445 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1446 | yield(); |
1447 | return 0; | |
1448 | } | |
1da177e4 LT |
1449 | return -ESRCH; |
1450 | } | |
910a7e90 EB |
1451 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1452 | ||
15e47304 | 1453 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1454 | u32 group, gfp_t allocation) |
1455 | { | |
15e47304 | 1456 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1457 | NULL, NULL); |
1458 | } | |
6ac552fd | 1459 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1460 | |
1461 | struct netlink_set_err_data { | |
1462 | struct sock *exclude_sk; | |
15e47304 | 1463 | u32 portid; |
1da177e4 LT |
1464 | u32 group; |
1465 | int code; | |
1466 | }; | |
1467 | ||
b57ef81f | 1468 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1469 | { |
1470 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1471 | int ret = 0; |
1da177e4 LT |
1472 | |
1473 | if (sk == p->exclude_sk) | |
1474 | goto out; | |
1475 | ||
09ad9bc7 | 1476 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1477 | goto out; |
1478 | ||
15e47304 | 1479 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1480 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1481 | goto out; |
1482 | ||
cc3a572f | 1483 | if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
1a50307b PNA |
1484 | ret = 1; |
1485 | goto out; | |
1486 | } | |
1487 | ||
1da177e4 LT |
1488 | sk->sk_err = p->code; |
1489 | sk->sk_error_report(sk); | |
1490 | out: | |
1a50307b | 1491 | return ret; |
1da177e4 LT |
1492 | } |
1493 | ||
4843b93c PNA |
1494 | /** |
1495 | * netlink_set_err - report error to broadcast listeners | |
1496 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1497 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1498 | * @group: the broadcast group that will notice the error |
4843b93c | 1499 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1500 | * |
1501 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1502 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1503 | */ |
15e47304 | 1504 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1505 | { |
1506 | struct netlink_set_err_data info; | |
1da177e4 | 1507 | struct sock *sk; |
1a50307b | 1508 | int ret = 0; |
1da177e4 LT |
1509 | |
1510 | info.exclude_sk = ssk; | |
15e47304 | 1511 | info.portid = portid; |
1da177e4 | 1512 | info.group = group; |
4843b93c PNA |
1513 | /* sk->sk_err wants a positive error value */ |
1514 | info.code = -code; | |
1da177e4 LT |
1515 | |
1516 | read_lock(&nl_table_lock); | |
1517 | ||
b67bfe0d | 1518 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1519 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1520 | |
1521 | read_unlock(&nl_table_lock); | |
1a50307b | 1522 | return ret; |
1da177e4 | 1523 | } |
dd5b6ce6 | 1524 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1525 | |
84659eb5 JB |
1526 | /* must be called with netlink table grabbed */ |
1527 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1528 | unsigned int group, | |
1529 | int is_new) | |
1530 | { | |
1531 | int old, new = !!is_new, subscriptions; | |
1532 | ||
1533 | old = test_bit(group - 1, nlk->groups); | |
1534 | subscriptions = nlk->subscriptions - old + new; | |
1535 | if (new) | |
1536 | __set_bit(group - 1, nlk->groups); | |
1537 | else | |
1538 | __clear_bit(group - 1, nlk->groups); | |
1539 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1540 | netlink_update_listeners(&nlk->sk); | |
1541 | } | |
1542 | ||
9a4595bc | 1543 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1544 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1545 | { |
1546 | struct sock *sk = sock->sk; | |
1547 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1548 | unsigned int val = 0; |
1549 | int err; | |
9a4595bc PM |
1550 | |
1551 | if (level != SOL_NETLINK) | |
1552 | return -ENOPROTOOPT; | |
1553 | ||
d1b4c689 | 1554 | if (optlen >= sizeof(int) && |
eb496534 | 1555 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1556 | return -EFAULT; |
1557 | ||
1558 | switch (optname) { | |
1559 | case NETLINK_PKTINFO: | |
1560 | if (val) | |
cc3a572f | 1561 | nlk->flags |= NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1562 | else |
cc3a572f | 1563 | nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1564 | err = 0; |
1565 | break; | |
1566 | case NETLINK_ADD_MEMBERSHIP: | |
1567 | case NETLINK_DROP_MEMBERSHIP: { | |
5187cd05 | 1568 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1569 | return -EPERM; |
b4ff4f04 JB |
1570 | err = netlink_realloc_groups(sk); |
1571 | if (err) | |
1572 | return err; | |
9a4595bc PM |
1573 | if (!val || val - 1 >= nlk->ngroups) |
1574 | return -EINVAL; | |
7774d5e0 | 1575 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1576 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1577 | if (err) |
1578 | return err; | |
1579 | } | |
9a4595bc | 1580 | netlink_table_grab(); |
84659eb5 JB |
1581 | netlink_update_socket_mc(nlk, val, |
1582 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1583 | netlink_table_ungrab(); |
7774d5e0 | 1584 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1585 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1586 | |
9a4595bc PM |
1587 | err = 0; |
1588 | break; | |
1589 | } | |
be0c22a4 PNA |
1590 | case NETLINK_BROADCAST_ERROR: |
1591 | if (val) | |
cc3a572f | 1592 | nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1593 | else |
cc3a572f | 1594 | nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 PNA |
1595 | err = 0; |
1596 | break; | |
38938bfe PNA |
1597 | case NETLINK_NO_ENOBUFS: |
1598 | if (val) { | |
cc3a572f ND |
1599 | nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
1600 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); | |
38938bfe | 1601 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1602 | } else { |
cc3a572f | 1603 | nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
658cb354 | 1604 | } |
38938bfe PNA |
1605 | err = 0; |
1606 | break; | |
59324cf3 ND |
1607 | case NETLINK_LISTEN_ALL_NSID: |
1608 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1609 | return -EPERM; | |
1610 | ||
1611 | if (val) | |
1612 | nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; | |
1613 | else | |
1614 | nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; | |
1615 | err = 0; | |
1616 | break; | |
0a6a3a23 CR |
1617 | case NETLINK_CAP_ACK: |
1618 | if (val) | |
1619 | nlk->flags |= NETLINK_F_CAP_ACK; | |
1620 | else | |
1621 | nlk->flags &= ~NETLINK_F_CAP_ACK; | |
1622 | err = 0; | |
1623 | break; | |
9a4595bc PM |
1624 | default: |
1625 | err = -ENOPROTOOPT; | |
1626 | } | |
1627 | return err; | |
1628 | } | |
1629 | ||
1630 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1631 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1632 | { |
1633 | struct sock *sk = sock->sk; | |
1634 | struct netlink_sock *nlk = nlk_sk(sk); | |
1635 | int len, val, err; | |
1636 | ||
1637 | if (level != SOL_NETLINK) | |
1638 | return -ENOPROTOOPT; | |
1639 | ||
1640 | if (get_user(len, optlen)) | |
1641 | return -EFAULT; | |
1642 | if (len < 0) | |
1643 | return -EINVAL; | |
1644 | ||
1645 | switch (optname) { | |
1646 | case NETLINK_PKTINFO: | |
1647 | if (len < sizeof(int)) | |
1648 | return -EINVAL; | |
1649 | len = sizeof(int); | |
cc3a572f | 1650 | val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
a27b58fe HC |
1651 | if (put_user(len, optlen) || |
1652 | put_user(val, optval)) | |
1653 | return -EFAULT; | |
9a4595bc PM |
1654 | err = 0; |
1655 | break; | |
be0c22a4 PNA |
1656 | case NETLINK_BROADCAST_ERROR: |
1657 | if (len < sizeof(int)) | |
1658 | return -EINVAL; | |
1659 | len = sizeof(int); | |
cc3a572f | 1660 | val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
be0c22a4 PNA |
1661 | if (put_user(len, optlen) || |
1662 | put_user(val, optval)) | |
1663 | return -EFAULT; | |
1664 | err = 0; | |
1665 | break; | |
38938bfe PNA |
1666 | case NETLINK_NO_ENOBUFS: |
1667 | if (len < sizeof(int)) | |
1668 | return -EINVAL; | |
1669 | len = sizeof(int); | |
cc3a572f | 1670 | val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
38938bfe PNA |
1671 | if (put_user(len, optlen) || |
1672 | put_user(val, optval)) | |
1673 | return -EFAULT; | |
1674 | err = 0; | |
1675 | break; | |
b42be38b DH |
1676 | case NETLINK_LIST_MEMBERSHIPS: { |
1677 | int pos, idx, shift; | |
1678 | ||
1679 | err = 0; | |
47191d65 | 1680 | netlink_lock_table(); |
b42be38b DH |
1681 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1682 | if (len - pos < sizeof(u32)) | |
1683 | break; | |
1684 | ||
1685 | idx = pos / sizeof(unsigned long); | |
1686 | shift = (pos % sizeof(unsigned long)) * 8; | |
1687 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1688 | (u32 __user *)(optval + pos))) { | |
1689 | err = -EFAULT; | |
1690 | break; | |
1691 | } | |
1692 | } | |
1693 | if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) | |
1694 | err = -EFAULT; | |
47191d65 | 1695 | netlink_unlock_table(); |
b42be38b DH |
1696 | break; |
1697 | } | |
0a6a3a23 CR |
1698 | case NETLINK_CAP_ACK: |
1699 | if (len < sizeof(int)) | |
1700 | return -EINVAL; | |
1701 | len = sizeof(int); | |
1702 | val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; | |
1703 | if (put_user(len, optlen) || | |
1704 | put_user(val, optval)) | |
1705 | return -EFAULT; | |
1706 | err = 0; | |
1707 | break; | |
9a4595bc PM |
1708 | default: |
1709 | err = -ENOPROTOOPT; | |
1710 | } | |
1711 | return err; | |
1712 | } | |
1713 | ||
1714 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1715 | { | |
1716 | struct nl_pktinfo info; | |
1717 | ||
1718 | info.group = NETLINK_CB(skb).dst_group; | |
1719 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1720 | } | |
1721 | ||
59324cf3 ND |
1722 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1723 | struct sk_buff *skb) | |
1724 | { | |
1725 | if (!NETLINK_CB(skb).nsid_is_set) | |
1726 | return; | |
1727 | ||
1728 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1729 | &NETLINK_CB(skb).nsid); | |
1730 | } | |
1731 | ||
1b784140 | 1732 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1733 | { |
1da177e4 LT |
1734 | struct sock *sk = sock->sk; |
1735 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1736 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1737 | u32 dst_portid; |
d629b836 | 1738 | u32 dst_group; |
1da177e4 LT |
1739 | struct sk_buff *skb; |
1740 | int err; | |
1741 | struct scm_cookie scm; | |
2d7a85f4 | 1742 | u32 netlink_skb_flags = 0; |
1da177e4 LT |
1743 | |
1744 | if (msg->msg_flags&MSG_OOB) | |
1745 | return -EOPNOTSUPP; | |
1746 | ||
7cc05662 | 1747 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1748 | if (err < 0) |
1749 | return err; | |
1750 | ||
1751 | if (msg->msg_namelen) { | |
b47030c7 | 1752 | err = -EINVAL; |
1da177e4 | 1753 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1754 | goto out; |
15e47304 | 1755 | dst_portid = addr->nl_pid; |
d629b836 | 1756 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1757 | err = -EPERM; |
15e47304 | 1758 | if ((dst_group || dst_portid) && |
5187cd05 | 1759 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1760 | goto out; |
2d7a85f4 | 1761 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1762 | } else { |
15e47304 | 1763 | dst_portid = nlk->dst_portid; |
d629b836 | 1764 | dst_group = nlk->dst_group; |
1da177e4 LT |
1765 | } |
1766 | ||
da314c99 | 1767 | if (!nlk->bound) { |
1da177e4 LT |
1768 | err = netlink_autobind(sock); |
1769 | if (err) | |
1770 | goto out; | |
da314c99 HX |
1771 | } else { |
1772 | /* Ensure nlk is hashed and visible. */ | |
1773 | smp_rmb(); | |
1da177e4 LT |
1774 | } |
1775 | ||
1776 | err = -EMSGSIZE; | |
1777 | if (len > sk->sk_sndbuf - 32) | |
1778 | goto out; | |
1779 | err = -ENOBUFS; | |
3a36515f | 1780 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1781 | if (skb == NULL) |
1da177e4 LT |
1782 | goto out; |
1783 | ||
15e47304 | 1784 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1785 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1786 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1787 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1788 | |
1da177e4 | 1789 | err = -EFAULT; |
6ce8e9ce | 1790 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1791 | kfree_skb(skb); |
1792 | goto out; | |
1793 | } | |
1794 | ||
1795 | err = security_netlink_send(sk, skb); | |
1796 | if (err) { | |
1797 | kfree_skb(skb); | |
1798 | goto out; | |
1799 | } | |
1800 | ||
d629b836 | 1801 | if (dst_group) { |
1da177e4 | 1802 | atomic_inc(&skb->users); |
15e47304 | 1803 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1804 | } |
15e47304 | 1805 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1806 | |
1807 | out: | |
7cc05662 | 1808 | scm_destroy(&scm); |
1da177e4 LT |
1809 | return err; |
1810 | } | |
1811 | ||
1b784140 | 1812 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1813 | int flags) |
1814 | { | |
1da177e4 LT |
1815 | struct scm_cookie scm; |
1816 | struct sock *sk = sock->sk; | |
1817 | struct netlink_sock *nlk = nlk_sk(sk); | |
1818 | int noblock = flags&MSG_DONTWAIT; | |
1819 | size_t copied; | |
68d6ac6d | 1820 | struct sk_buff *skb, *data_skb; |
b44d211e | 1821 | int err, ret; |
1da177e4 LT |
1822 | |
1823 | if (flags&MSG_OOB) | |
1824 | return -EOPNOTSUPP; | |
1825 | ||
1826 | copied = 0; | |
1827 | ||
6ac552fd PM |
1828 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1829 | if (skb == NULL) | |
1da177e4 LT |
1830 | goto out; |
1831 | ||
68d6ac6d JB |
1832 | data_skb = skb; |
1833 | ||
1dacc76d JB |
1834 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1835 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1836 | /* |
68d6ac6d JB |
1837 | * If this skb has a frag_list, then here that means that we |
1838 | * will have to use the frag_list skb's data for compat tasks | |
1839 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1840 | * |
68d6ac6d JB |
1841 | * If we need to send the compat skb, assign it to the |
1842 | * 'data_skb' variable so that it will be used below for data | |
1843 | * copying. We keep 'skb' for everything else, including | |
1844 | * freeing both later. | |
1dacc76d | 1845 | */ |
68d6ac6d JB |
1846 | if (flags & MSG_CMSG_COMPAT) |
1847 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1848 | } |
1849 | #endif | |
1850 | ||
9063e21f ED |
1851 | /* Record the max length of recvmsg() calls for future allocations */ |
1852 | nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); | |
1853 | nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, | |
d35c99ff | 1854 | SKB_WITH_OVERHEAD(32768)); |
9063e21f | 1855 | |
68d6ac6d | 1856 | copied = data_skb->len; |
1da177e4 LT |
1857 | if (len < copied) { |
1858 | msg->msg_flags |= MSG_TRUNC; | |
1859 | copied = len; | |
1860 | } | |
1861 | ||
68d6ac6d | 1862 | skb_reset_transport_header(data_skb); |
51f3d02b | 1863 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
1864 | |
1865 | if (msg->msg_name) { | |
342dfc30 | 1866 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
1867 | addr->nl_family = AF_NETLINK; |
1868 | addr->nl_pad = 0; | |
15e47304 | 1869 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1870 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1871 | msg->msg_namelen = sizeof(*addr); |
1872 | } | |
1873 | ||
cc3a572f | 1874 | if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
cc9a06cd | 1875 | netlink_cmsg_recv_pktinfo(msg, skb); |
59324cf3 ND |
1876 | if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
1877 | netlink_cmsg_listen_all_nsid(sk, msg, skb); | |
cc9a06cd | 1878 | |
7cc05662 CH |
1879 | memset(&scm, 0, sizeof(scm)); |
1880 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1881 | if (flags & MSG_TRUNC) |
68d6ac6d | 1882 | copied = data_skb->len; |
daa3766e | 1883 | |
1da177e4 LT |
1884 | skb_free_datagram(sk, skb); |
1885 | ||
16b304f3 PS |
1886 | if (nlk->cb_running && |
1887 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
1888 | ret = netlink_dump(sk); |
1889 | if (ret) { | |
ac30ef83 | 1890 | sk->sk_err = -ret; |
b44d211e AV |
1891 | sk->sk_error_report(sk); |
1892 | } | |
1893 | } | |
1da177e4 | 1894 | |
7cc05662 | 1895 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
1896 | out: |
1897 | netlink_rcv_wake(sk); | |
1898 | return err ? : copied; | |
1899 | } | |
1900 | ||
676d2369 | 1901 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 1902 | { |
cd40b7d3 | 1903 | BUG(); |
1da177e4 LT |
1904 | } |
1905 | ||
1906 | /* | |
746fac4d | 1907 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1908 | * complete set of kernel non-blocking support for message |
1909 | * queueing. | |
1910 | */ | |
1911 | ||
1912 | struct sock * | |
9f00d977 PNA |
1913 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
1914 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
1915 | { |
1916 | struct socket *sock; | |
1917 | struct sock *sk; | |
77247bbb | 1918 | struct netlink_sock *nlk; |
5c398dc8 | 1919 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
1920 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
1921 | unsigned int groups; | |
1da177e4 | 1922 | |
fab2caf6 | 1923 | BUG_ON(!nl_table); |
1da177e4 | 1924 | |
6ac552fd | 1925 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1926 | return NULL; |
1927 | ||
1928 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1929 | return NULL; | |
13d3078e EB |
1930 | |
1931 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
1932 | goto out_sock_release_nosk; |
1933 | ||
1934 | sk = sock->sk; | |
4fdb3bb7 | 1935 | |
a31f2d17 | 1936 | if (!cfg || cfg->groups < 32) |
4277a083 | 1937 | groups = 32; |
a31f2d17 PNA |
1938 | else |
1939 | groups = cfg->groups; | |
4277a083 | 1940 | |
5c398dc8 | 1941 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1942 | if (!listeners) |
1943 | goto out_sock_release; | |
1944 | ||
1da177e4 | 1945 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
1946 | if (cfg && cfg->input) |
1947 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 1948 | |
8ea65f4a | 1949 | if (netlink_insert(sk, 0)) |
77247bbb | 1950 | goto out_sock_release; |
4fdb3bb7 | 1951 | |
77247bbb | 1952 | nlk = nlk_sk(sk); |
cc3a572f | 1953 | nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
4fdb3bb7 | 1954 | |
4fdb3bb7 | 1955 | netlink_table_grab(); |
b4b51029 EB |
1956 | if (!nl_table[unit].registered) { |
1957 | nl_table[unit].groups = groups; | |
5c398dc8 | 1958 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1959 | nl_table[unit].cb_mutex = cb_mutex; |
1960 | nl_table[unit].module = module; | |
9785e10a PNA |
1961 | if (cfg) { |
1962 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 1963 | nl_table[unit].unbind = cfg->unbind; |
9785e10a | 1964 | nl_table[unit].flags = cfg->flags; |
da12c90e G |
1965 | if (cfg->compare) |
1966 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 1967 | } |
b4b51029 | 1968 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
1969 | } else { |
1970 | kfree(listeners); | |
869e58f8 | 1971 | nl_table[unit].registered++; |
b4b51029 | 1972 | } |
4fdb3bb7 | 1973 | netlink_table_ungrab(); |
77247bbb PM |
1974 | return sk; |
1975 | ||
4fdb3bb7 | 1976 | out_sock_release: |
4277a083 | 1977 | kfree(listeners); |
9dfbec1f | 1978 | netlink_kernel_release(sk); |
23fe1866 PE |
1979 | return NULL; |
1980 | ||
1981 | out_sock_release_nosk: | |
4fdb3bb7 | 1982 | sock_release(sock); |
77247bbb | 1983 | return NULL; |
1da177e4 | 1984 | } |
9f00d977 | 1985 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
1986 | |
1987 | void | |
1988 | netlink_kernel_release(struct sock *sk) | |
1989 | { | |
13d3078e EB |
1990 | if (sk == NULL || sk->sk_socket == NULL) |
1991 | return; | |
1992 | ||
1993 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
1994 | } |
1995 | EXPORT_SYMBOL(netlink_kernel_release); | |
1996 | ||
d136f1bd | 1997 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 1998 | { |
5c398dc8 | 1999 | struct listeners *new, *old; |
b4ff4f04 | 2000 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2001 | |
2002 | if (groups < 32) | |
2003 | groups = 32; | |
2004 | ||
b4ff4f04 | 2005 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2006 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2007 | if (!new) | |
d136f1bd | 2008 | return -ENOMEM; |
6d772ac5 | 2009 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2010 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2011 | rcu_assign_pointer(tbl->listeners, new); | |
2012 | ||
37b6b935 | 2013 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2014 | } |
2015 | tbl->groups = groups; | |
2016 | ||
d136f1bd JB |
2017 | return 0; |
2018 | } | |
2019 | ||
2020 | /** | |
2021 | * netlink_change_ngroups - change number of multicast groups | |
2022 | * | |
2023 | * This changes the number of multicast groups that are available | |
2024 | * on a certain netlink family. Note that it is not possible to | |
2025 | * change the number of groups to below 32. Also note that it does | |
2026 | * not implicitly call netlink_clear_multicast_users() when the | |
2027 | * number of groups is reduced. | |
2028 | * | |
2029 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2030 | * @groups: The new number of groups. | |
2031 | */ | |
2032 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2033 | { | |
2034 | int err; | |
2035 | ||
2036 | netlink_table_grab(); | |
2037 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2038 | netlink_table_ungrab(); |
d136f1bd | 2039 | |
b4ff4f04 JB |
2040 | return err; |
2041 | } | |
b4ff4f04 | 2042 | |
b8273570 JB |
2043 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2044 | { | |
2045 | struct sock *sk; | |
b8273570 JB |
2046 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2047 | ||
b67bfe0d | 2048 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2049 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2050 | } | |
2051 | ||
a46621a3 | 2052 | struct nlmsghdr * |
15e47304 | 2053 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2054 | { |
2055 | struct nlmsghdr *nlh; | |
573ce260 | 2056 | int size = nlmsg_msg_size(len); |
a46621a3 | 2057 | |
23b45672 | 2058 | nlh = (struct nlmsghdr *)skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2059 | nlh->nlmsg_type = type; |
2060 | nlh->nlmsg_len = size; | |
2061 | nlh->nlmsg_flags = flags; | |
15e47304 | 2062 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2063 | nlh->nlmsg_seq = seq; |
2064 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2065 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2066 | return nlh; |
2067 | } | |
2068 | EXPORT_SYMBOL(__nlmsg_put); | |
2069 | ||
1da177e4 LT |
2070 | /* |
2071 | * It looks a bit ugly. | |
2072 | * It would be better to create kernel thread. | |
2073 | */ | |
2074 | ||
2075 | static int netlink_dump(struct sock *sk) | |
2076 | { | |
2077 | struct netlink_sock *nlk = nlk_sk(sk); | |
2078 | struct netlink_callback *cb; | |
c7ac8679 | 2079 | struct sk_buff *skb = NULL; |
1da177e4 | 2080 | struct nlmsghdr *nlh; |
92964c79 | 2081 | struct module *module; |
bf8b79e4 | 2082 | int len, err = -ENOBUFS; |
db65a3aa | 2083 | int alloc_min_size; |
c7ac8679 | 2084 | int alloc_size; |
1da177e4 | 2085 | |
af65bdfc | 2086 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2087 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2088 | err = -EINVAL; |
2089 | goto errout_skb; | |
1da177e4 LT |
2090 | } |
2091 | ||
d1b4c689 | 2092 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2093 | goto errout_skb; |
9063e21f ED |
2094 | |
2095 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2096 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2097 | * to reduce number of system calls on dump operations, if user | |
2098 | * ever provided a big enough buffer. | |
2099 | */ | |
db65a3aa AR |
2100 | cb = &nlk->cb; |
2101 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2102 | ||
2103 | if (alloc_min_size < nlk->max_recvmsg_len) { | |
2104 | alloc_size = nlk->max_recvmsg_len; | |
d35c99ff ED |
2105 | skb = alloc_skb(alloc_size, |
2106 | (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | | |
2107 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2108 | } |
db65a3aa AR |
2109 | if (!skb) { |
2110 | alloc_size = alloc_min_size; | |
c5b0db32 | 2111 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2112 | } |
c7ac8679 | 2113 | if (!skb) |
c63d6ea3 | 2114 | goto errout_skb; |
db65a3aa AR |
2115 | |
2116 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2117 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2118 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2119 | * could fit within the allocated skb. skb is typically allocated | |
2120 | * with larger space than required (could be as much as near 2x the | |
2121 | * requested size with align to next power of 2 approach). Allowing | |
2122 | * dump to use the excess space makes it difficult for a user to have a | |
2123 | * reasonable static buffer based on the expected largest dump of a | |
2124 | * single netdev. The outcome is MSG_TRUNC error. | |
2125 | */ | |
d1b4c689 | 2126 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
f9c22888 | 2127 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2128 | |
1da177e4 LT |
2129 | len = cb->dump(skb, cb); |
2130 | ||
2131 | if (len > 0) { | |
af65bdfc | 2132 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2133 | |
2134 | if (sk_filter(sk, skb)) | |
2135 | kfree_skb(skb); | |
4a7e7c2a ED |
2136 | else |
2137 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2138 | return 0; |
2139 | } | |
2140 | ||
bf8b79e4 TG |
2141 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
2142 | if (!nlh) | |
2143 | goto errout_skb; | |
2144 | ||
670dc283 JB |
2145 | nl_dump_check_consistent(cb, nlh); |
2146 | ||
bf8b79e4 TG |
2147 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
2148 | ||
b1153f29 SH |
2149 | if (sk_filter(sk, skb)) |
2150 | kfree_skb(skb); | |
4a7e7c2a ED |
2151 | else |
2152 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2153 | |
a8f74b22 TG |
2154 | if (cb->done) |
2155 | cb->done(cb); | |
1da177e4 | 2156 | |
16b304f3 | 2157 | nlk->cb_running = false; |
92964c79 HX |
2158 | module = cb->module; |
2159 | skb = cb->skb; | |
16b304f3 | 2160 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2161 | module_put(module); |
2162 | consume_skb(skb); | |
1da177e4 | 2163 | return 0; |
1797754e | 2164 | |
bf8b79e4 | 2165 | errout_skb: |
af65bdfc | 2166 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2167 | kfree_skb(skb); |
bf8b79e4 | 2168 | return err; |
1da177e4 LT |
2169 | } |
2170 | ||
6dc878a8 G |
2171 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2172 | const struct nlmsghdr *nlh, | |
2173 | struct netlink_dump_control *control) | |
1da177e4 LT |
2174 | { |
2175 | struct netlink_callback *cb; | |
2176 | struct sock *sk; | |
2177 | struct netlink_sock *nlk; | |
b44d211e | 2178 | int ret; |
1da177e4 | 2179 | |
d1b4c689 | 2180 | atomic_inc(&skb->users); |
f9c22888 | 2181 | |
15e47304 | 2182 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2183 | if (sk == NULL) { |
16b304f3 PS |
2184 | ret = -ECONNREFUSED; |
2185 | goto error_free; | |
1da177e4 | 2186 | } |
6dc878a8 | 2187 | |
16b304f3 | 2188 | nlk = nlk_sk(sk); |
af65bdfc | 2189 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2190 | /* A dump is in progress... */ |
16b304f3 | 2191 | if (nlk->cb_running) { |
6dc878a8 | 2192 | ret = -EBUSY; |
16b304f3 | 2193 | goto error_unlock; |
1da177e4 | 2194 | } |
6dc878a8 | 2195 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2196 | if (!try_module_get(control->module)) { |
6dc878a8 | 2197 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2198 | goto error_unlock; |
6dc878a8 G |
2199 | } |
2200 | ||
16b304f3 PS |
2201 | cb = &nlk->cb; |
2202 | memset(cb, 0, sizeof(*cb)); | |
fc9e50f5 | 2203 | cb->start = control->start; |
16b304f3 PS |
2204 | cb->dump = control->dump; |
2205 | cb->done = control->done; | |
2206 | cb->nlh = nlh; | |
2207 | cb->data = control->data; | |
2208 | cb->module = control->module; | |
2209 | cb->min_dump_alloc = control->min_dump_alloc; | |
2210 | cb->skb = skb; | |
2211 | ||
2212 | nlk->cb_running = true; | |
2213 | ||
af65bdfc | 2214 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2215 | |
fc9e50f5 TH |
2216 | if (cb->start) |
2217 | cb->start(cb); | |
2218 | ||
b44d211e | 2219 | ret = netlink_dump(sk); |
1da177e4 | 2220 | sock_put(sk); |
5c58298c | 2221 | |
b44d211e AV |
2222 | if (ret) |
2223 | return ret; | |
2224 | ||
5c58298c DL |
2225 | /* We successfully started a dump, by returning -EINTR we |
2226 | * signal not to send ACK even if it was requested. | |
2227 | */ | |
2228 | return -EINTR; | |
16b304f3 PS |
2229 | |
2230 | error_unlock: | |
2231 | sock_put(sk); | |
2232 | mutex_unlock(nlk->cb_mutex); | |
2233 | error_free: | |
2234 | kfree_skb(skb); | |
2235 | return ret; | |
1da177e4 | 2236 | } |
6dc878a8 | 2237 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
2238 | |
2239 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
2240 | { | |
2241 | struct sk_buff *skb; | |
2242 | struct nlmsghdr *rep; | |
2243 | struct nlmsgerr *errmsg; | |
339bf98f | 2244 | size_t payload = sizeof(*errmsg); |
0a6a3a23 | 2245 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
1da177e4 | 2246 | |
0a6a3a23 CR |
2247 | /* Error messages get the original request appened, unless the user |
2248 | * requests to cap the error message. | |
2249 | */ | |
2250 | if (!(nlk->flags & NETLINK_F_CAP_ACK) && err) | |
339bf98f | 2251 | payload += nlmsg_len(nlh); |
1da177e4 | 2252 | |
c5b0db32 | 2253 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
2254 | if (!skb) { |
2255 | struct sock *sk; | |
2256 | ||
3b1e0a65 | 2257 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 2258 | in_skb->sk->sk_protocol, |
15e47304 | 2259 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
2260 | if (sk) { |
2261 | sk->sk_err = ENOBUFS; | |
2262 | sk->sk_error_report(sk); | |
2263 | sock_put(sk); | |
2264 | } | |
2265 | return; | |
2266 | } | |
2267 | ||
15e47304 | 2268 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 2269 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 2270 | errmsg = nlmsg_data(rep); |
1da177e4 | 2271 | errmsg->error = err; |
0a6a3a23 | 2272 | memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 2273 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2274 | } |
6ac552fd | 2275 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2276 | |
cd40b7d3 | 2277 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 2278 | struct nlmsghdr *)) |
82ace47a | 2279 | { |
82ace47a TG |
2280 | struct nlmsghdr *nlh; |
2281 | int err; | |
2282 | ||
2283 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2284 | int msglen; |
2285 | ||
b529ccf2 | 2286 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2287 | err = 0; |
82ace47a | 2288 | |
ad8e4b75 | 2289 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2290 | return 0; |
2291 | ||
d35b6856 TG |
2292 | /* Only requests are handled by the kernel */ |
2293 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2294 | goto ack; |
45e7ae7f TG |
2295 | |
2296 | /* Skip control messages */ | |
2297 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2298 | goto ack; |
d35b6856 | 2299 | |
1d00a4eb | 2300 | err = cb(skb, nlh); |
5c58298c DL |
2301 | if (err == -EINTR) |
2302 | goto skip; | |
2303 | ||
2304 | ack: | |
d35b6856 | 2305 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 2306 | netlink_ack(skb, nlh, err); |
82ace47a | 2307 | |
5c58298c | 2308 | skip: |
6ac552fd | 2309 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2310 | if (msglen > skb->len) |
2311 | msglen = skb->len; | |
2312 | skb_pull(skb, msglen); | |
82ace47a TG |
2313 | } |
2314 | ||
2315 | return 0; | |
2316 | } | |
6ac552fd | 2317 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2318 | |
d387f6ad TG |
2319 | /** |
2320 | * nlmsg_notify - send a notification netlink message | |
2321 | * @sk: netlink socket to use | |
2322 | * @skb: notification message | |
15e47304 | 2323 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2324 | * @group: destination multicast group or 0 |
2325 | * @report: 1 to report back, 0 to disable | |
2326 | * @flags: allocation flags | |
2327 | */ | |
15e47304 | 2328 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2329 | unsigned int group, int report, gfp_t flags) |
2330 | { | |
2331 | int err = 0; | |
2332 | ||
2333 | if (group) { | |
15e47304 | 2334 | int exclude_portid = 0; |
d387f6ad TG |
2335 | |
2336 | if (report) { | |
2337 | atomic_inc(&skb->users); | |
15e47304 | 2338 | exclude_portid = portid; |
d387f6ad TG |
2339 | } |
2340 | ||
1ce85fe4 PNA |
2341 | /* errors reported via destination sk->sk_err, but propagate |
2342 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2343 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2344 | } |
2345 | ||
1ce85fe4 PNA |
2346 | if (report) { |
2347 | int err2; | |
2348 | ||
15e47304 | 2349 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2350 | if (!err || err == -ESRCH) |
2351 | err = err2; | |
2352 | } | |
d387f6ad TG |
2353 | |
2354 | return err; | |
2355 | } | |
6ac552fd | 2356 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2357 | |
1da177e4 LT |
2358 | #ifdef CONFIG_PROC_FS |
2359 | struct nl_seq_iter { | |
e372c414 | 2360 | struct seq_net_private p; |
56d28b1e | 2361 | struct rhashtable_iter hti; |
1da177e4 | 2362 | int link; |
1da177e4 LT |
2363 | }; |
2364 | ||
56d28b1e | 2365 | static int netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2366 | { |
56d28b1e | 2367 | int err; |
1da177e4 | 2368 | |
8f6fd83c BC |
2369 | err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti, |
2370 | GFP_KERNEL); | |
56d28b1e HX |
2371 | if (err) { |
2372 | iter->link = MAX_LINKS; | |
2373 | return err; | |
1da177e4 | 2374 | } |
56d28b1e HX |
2375 | |
2376 | err = rhashtable_walk_start(&iter->hti); | |
2377 | return err == -EAGAIN ? 0 : err; | |
1da177e4 LT |
2378 | } |
2379 | ||
56d28b1e | 2380 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2381 | { |
56d28b1e HX |
2382 | rhashtable_walk_stop(&iter->hti); |
2383 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2384 | } |
2385 | ||
56d28b1e | 2386 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2387 | { |
56d28b1e | 2388 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2389 | struct netlink_sock *nlk; |
1da177e4 | 2390 | |
56d28b1e HX |
2391 | do { |
2392 | for (;;) { | |
2393 | int err; | |
1da177e4 | 2394 | |
56d28b1e | 2395 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2396 | |
56d28b1e HX |
2397 | if (IS_ERR(nlk)) { |
2398 | if (PTR_ERR(nlk) == -EAGAIN) | |
2399 | continue; | |
e341694e | 2400 | |
56d28b1e HX |
2401 | return nlk; |
2402 | } | |
1da177e4 | 2403 | |
56d28b1e HX |
2404 | if (nlk) |
2405 | break; | |
1da177e4 | 2406 | |
56d28b1e HX |
2407 | netlink_walk_stop(iter); |
2408 | if (++iter->link >= MAX_LINKS) | |
2409 | return NULL; | |
da12c90e | 2410 | |
56d28b1e HX |
2411 | err = netlink_walk_start(iter); |
2412 | if (err) | |
2413 | return ERR_PTR(err); | |
1da177e4 | 2414 | } |
56d28b1e | 2415 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2416 | |
56d28b1e HX |
2417 | return nlk; |
2418 | } | |
1da177e4 | 2419 | |
56d28b1e HX |
2420 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
2421 | { | |
2422 | struct nl_seq_iter *iter = seq->private; | |
2423 | void *obj = SEQ_START_TOKEN; | |
2424 | loff_t pos; | |
2425 | int err; | |
2426 | ||
2427 | iter->link = 0; | |
2428 | ||
2429 | err = netlink_walk_start(iter); | |
2430 | if (err) | |
2431 | return ERR_PTR(err); | |
2432 | ||
2433 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2434 | obj = __netlink_seq_next(seq); | |
2435 | ||
2436 | return obj; | |
2437 | } | |
2438 | ||
2439 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2440 | { | |
2441 | ++*pos; | |
2442 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2443 | } |
2444 | ||
2445 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2446 | { | |
56d28b1e HX |
2447 | struct nl_seq_iter *iter = seq->private; |
2448 | ||
2449 | if (iter->link >= MAX_LINKS) | |
2450 | return; | |
2451 | ||
2452 | netlink_walk_stop(iter); | |
1da177e4 LT |
2453 | } |
2454 | ||
2455 | ||
2456 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2457 | { | |
658cb354 | 2458 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2459 | seq_puts(seq, |
2460 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2461 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2462 | } else { |
1da177e4 LT |
2463 | struct sock *s = v; |
2464 | struct netlink_sock *nlk = nlk_sk(s); | |
2465 | ||
16b304f3 | 2466 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n", |
1da177e4 LT |
2467 | s, |
2468 | s->sk_protocol, | |
15e47304 | 2469 | nlk->portid, |
513c2500 | 2470 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2471 | sk_rmem_alloc_get(s), |
2472 | sk_wmem_alloc_get(s), | |
16b304f3 | 2473 | nlk->cb_running, |
38938bfe | 2474 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2475 | atomic_read(&s->sk_drops), |
2476 | sock_i_ino(s) | |
1da177e4 LT |
2477 | ); |
2478 | ||
2479 | } | |
2480 | return 0; | |
2481 | } | |
2482 | ||
56b3d975 | 2483 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2484 | .start = netlink_seq_start, |
2485 | .next = netlink_seq_next, | |
2486 | .stop = netlink_seq_stop, | |
2487 | .show = netlink_seq_show, | |
2488 | }; | |
2489 | ||
2490 | ||
2491 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2492 | { | |
e372c414 DL |
2493 | return seq_open_net(inode, file, &netlink_seq_ops, |
2494 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2495 | } |
2496 | ||
da7071d7 | 2497 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2498 | .owner = THIS_MODULE, |
2499 | .open = netlink_seq_open, | |
2500 | .read = seq_read, | |
2501 | .llseek = seq_lseek, | |
e372c414 | 2502 | .release = seq_release_net, |
1da177e4 LT |
2503 | }; |
2504 | ||
2505 | #endif | |
2506 | ||
2507 | int netlink_register_notifier(struct notifier_block *nb) | |
2508 | { | |
e041c683 | 2509 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2510 | } |
6ac552fd | 2511 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2512 | |
2513 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2514 | { | |
e041c683 | 2515 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2516 | } |
6ac552fd | 2517 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2518 | |
90ddc4f0 | 2519 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2520 | .family = PF_NETLINK, |
2521 | .owner = THIS_MODULE, | |
2522 | .release = netlink_release, | |
2523 | .bind = netlink_bind, | |
2524 | .connect = netlink_connect, | |
2525 | .socketpair = sock_no_socketpair, | |
2526 | .accept = sock_no_accept, | |
2527 | .getname = netlink_getname, | |
d1b4c689 | 2528 | .poll = datagram_poll, |
025c6818 | 2529 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2530 | .listen = sock_no_listen, |
2531 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2532 | .setsockopt = netlink_setsockopt, |
2533 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2534 | .sendmsg = netlink_sendmsg, |
2535 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2536 | .mmap = sock_no_mmap, |
1da177e4 LT |
2537 | .sendpage = sock_no_sendpage, |
2538 | }; | |
2539 | ||
ec1b4cf7 | 2540 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2541 | .family = PF_NETLINK, |
2542 | .create = netlink_create, | |
2543 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2544 | }; | |
2545 | ||
4665079c | 2546 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2547 | { |
2548 | #ifdef CONFIG_PROC_FS | |
d4beaa66 | 2549 | if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops)) |
b4b51029 EB |
2550 | return -ENOMEM; |
2551 | #endif | |
2552 | return 0; | |
2553 | } | |
2554 | ||
4665079c | 2555 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2556 | { |
2557 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2558 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2559 | #endif |
2560 | } | |
2561 | ||
b963ea89 DM |
2562 | static void __init netlink_add_usersock_entry(void) |
2563 | { | |
5c398dc8 | 2564 | struct listeners *listeners; |
b963ea89 DM |
2565 | int groups = 32; |
2566 | ||
5c398dc8 | 2567 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2568 | if (!listeners) |
5c398dc8 | 2569 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2570 | |
2571 | netlink_table_grab(); | |
2572 | ||
2573 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2574 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2575 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2576 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2577 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2578 | |
2579 | netlink_table_ungrab(); | |
2580 | } | |
2581 | ||
022cbae6 | 2582 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2583 | .init = netlink_net_init, |
2584 | .exit = netlink_net_exit, | |
2585 | }; | |
2586 | ||
49f7b33e | 2587 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2588 | { |
2589 | const struct netlink_sock *nlk = data; | |
2590 | struct netlink_compare_arg arg; | |
2591 | ||
da314c99 | 2592 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2593 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2594 | } |
2595 | ||
2596 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2597 | .head_offset = offsetof(struct netlink_sock, node), | |
2598 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2599 | .obj_hashfn = netlink_hash, |
2600 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2601 | .automatic_shrinking = true, |
c428ecd1 HX |
2602 | }; |
2603 | ||
1da177e4 LT |
2604 | static int __init netlink_proto_init(void) |
2605 | { | |
1da177e4 | 2606 | int i; |
1da177e4 LT |
2607 | int err = proto_register(&netlink_proto, 0); |
2608 | ||
2609 | if (err != 0) | |
2610 | goto out; | |
2611 | ||
fab25745 | 2612 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 2613 | |
0da974f4 | 2614 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2615 | if (!nl_table) |
2616 | goto panic; | |
1da177e4 | 2617 | |
1da177e4 | 2618 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2619 | if (rhashtable_init(&nl_table[i].hash, |
2620 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2621 | while (--i > 0) |
2622 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2623 | kfree(nl_table); |
fab2caf6 | 2624 | goto panic; |
1da177e4 | 2625 | } |
1da177e4 LT |
2626 | } |
2627 | ||
bcbde0d4 DB |
2628 | INIT_LIST_HEAD(&netlink_tap_all); |
2629 | ||
b963ea89 DM |
2630 | netlink_add_usersock_entry(); |
2631 | ||
1da177e4 | 2632 | sock_register(&netlink_family_ops); |
b4b51029 | 2633 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2634 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2635 | rtnetlink_init(); |
2636 | out: | |
2637 | return err; | |
fab2caf6 AM |
2638 | panic: |
2639 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2640 | } |
2641 | ||
1da177e4 | 2642 | core_initcall(netlink_proto_init); |