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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * NETLINK Kernel-user communication protocol. | |
4 | * | |
113aa838 | 5 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 6 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
cd1df525 | 7 | * Patrick McHardy <kaber@trash.net> |
1da177e4 | 8 | * |
1da177e4 LT |
9 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
10 | * added netlink_proto_exit | |
11 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
12 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
13 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
14 | * - inc module use count of module that owns | |
15 | * the kernel socket in case userspace opens | |
16 | * socket of same protocol | |
17 | * - remove all module support, since netlink is | |
18 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
19 | */ |
20 | ||
1da177e4 LT |
21 | #include <linux/module.h> |
22 | ||
4fc268d2 | 23 | #include <linux/capability.h> |
1da177e4 LT |
24 | #include <linux/kernel.h> |
25 | #include <linux/init.h> | |
1da177e4 LT |
26 | #include <linux/signal.h> |
27 | #include <linux/sched.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/string.h> | |
30 | #include <linux/stat.h> | |
31 | #include <linux/socket.h> | |
32 | #include <linux/un.h> | |
33 | #include <linux/fcntl.h> | |
34 | #include <linux/termios.h> | |
35 | #include <linux/sockios.h> | |
36 | #include <linux/net.h> | |
37 | #include <linux/fs.h> | |
38 | #include <linux/slab.h> | |
7c0f6ba6 | 39 | #include <linux/uaccess.h> |
1da177e4 LT |
40 | #include <linux/skbuff.h> |
41 | #include <linux/netdevice.h> | |
42 | #include <linux/rtnetlink.h> | |
43 | #include <linux/proc_fs.h> | |
44 | #include <linux/seq_file.h> | |
1da177e4 LT |
45 | #include <linux/notifier.h> |
46 | #include <linux/security.h> | |
47 | #include <linux/jhash.h> | |
48 | #include <linux/jiffies.h> | |
49 | #include <linux/random.h> | |
50 | #include <linux/bitops.h> | |
51 | #include <linux/mm.h> | |
52 | #include <linux/types.h> | |
54e0f520 | 53 | #include <linux/audit.h> |
af65bdfc | 54 | #include <linux/mutex.h> |
ccdfcc39 | 55 | #include <linux/vmalloc.h> |
bcbde0d4 | 56 | #include <linux/if_arp.h> |
e341694e | 57 | #include <linux/rhashtable.h> |
9652e931 | 58 | #include <asm/cacheflush.h> |
e341694e | 59 | #include <linux/hash.h> |
ee1c2442 | 60 | #include <linux/genetlink.h> |
7212462f | 61 | #include <linux/net_namespace.h> |
bc5b6c0b | 62 | #include <linux/nospec.h> |
951cf368 | 63 | #include <linux/btf_ids.h> |
54e0f520 | 64 | |
457c4cbc | 65 | #include <net/net_namespace.h> |
25e3f70f | 66 | #include <net/netns/generic.h> |
1da177e4 LT |
67 | #include <net/sock.h> |
68 | #include <net/scm.h> | |
82ace47a | 69 | #include <net/netlink.h> |
7e3ce05e MRL |
70 | #define CREATE_TRACE_POINTS |
71 | #include <trace/events/netlink.h> | |
1da177e4 | 72 | |
0f29c768 | 73 | #include "af_netlink.h" |
1da177e4 | 74 | |
5c398dc8 ED |
75 | struct listeners { |
76 | struct rcu_head rcu; | |
2b738124 | 77 | unsigned long masks[]; |
6c04bb18 JB |
78 | }; |
79 | ||
cd967e05 | 80 | /* state bits */ |
cc3a572f | 81 | #define NETLINK_S_CONGESTED 0x0 |
cd967e05 | 82 | |
035c4c16 | 83 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 | 84 | { |
cc3a572f | 85 | return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; |
aed81560 DL |
86 | } |
87 | ||
91dd93f9 | 88 | struct netlink_table *nl_table __read_mostly; |
0f29c768 | 89 | EXPORT_SYMBOL_GPL(nl_table); |
1da177e4 LT |
90 | |
91 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
92 | ||
8a0f5ccf HX |
93 | static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; |
94 | ||
95 | static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { | |
96 | "nlk_cb_mutex-ROUTE", | |
97 | "nlk_cb_mutex-1", | |
98 | "nlk_cb_mutex-USERSOCK", | |
99 | "nlk_cb_mutex-FIREWALL", | |
100 | "nlk_cb_mutex-SOCK_DIAG", | |
101 | "nlk_cb_mutex-NFLOG", | |
102 | "nlk_cb_mutex-XFRM", | |
103 | "nlk_cb_mutex-SELINUX", | |
104 | "nlk_cb_mutex-ISCSI", | |
105 | "nlk_cb_mutex-AUDIT", | |
106 | "nlk_cb_mutex-FIB_LOOKUP", | |
107 | "nlk_cb_mutex-CONNECTOR", | |
108 | "nlk_cb_mutex-NETFILTER", | |
109 | "nlk_cb_mutex-IP6_FW", | |
110 | "nlk_cb_mutex-DNRTMSG", | |
111 | "nlk_cb_mutex-KOBJECT_UEVENT", | |
112 | "nlk_cb_mutex-GENERIC", | |
113 | "nlk_cb_mutex-17", | |
114 | "nlk_cb_mutex-SCSITRANSPORT", | |
115 | "nlk_cb_mutex-ECRYPTFS", | |
116 | "nlk_cb_mutex-RDMA", | |
117 | "nlk_cb_mutex-CRYPTO", | |
118 | "nlk_cb_mutex-SMC", | |
119 | "nlk_cb_mutex-23", | |
120 | "nlk_cb_mutex-24", | |
121 | "nlk_cb_mutex-25", | |
122 | "nlk_cb_mutex-26", | |
123 | "nlk_cb_mutex-27", | |
124 | "nlk_cb_mutex-28", | |
125 | "nlk_cb_mutex-29", | |
126 | "nlk_cb_mutex-30", | |
127 | "nlk_cb_mutex-31", | |
128 | "nlk_cb_mutex-MAX_LINKS" | |
129 | }; | |
130 | ||
1da177e4 | 131 | static int netlink_dump(struct sock *sk); |
1da177e4 | 132 | |
78fd1d0a | 133 | /* nl_table locking explained: |
21e4902a | 134 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
c5adde94 | 135 | * and removal are protected with per bucket lock while using RCU list |
21e4902a TG |
136 | * modification primitives and may run in parallel to RCU protected lookups. |
137 | * Destruction of the Netlink socket may only occur *after* nl_table_lock has | |
138 | * been acquired * either during or after the socket has been removed from | |
139 | * the list and after an RCU grace period. | |
78fd1d0a | 140 | */ |
0f29c768 AV |
141 | DEFINE_RWLOCK(nl_table_lock); |
142 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
143 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
144 | ||
6d772ac5 ED |
145 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
146 | ||
efa172f4 | 147 | static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 148 | |
bcbde0d4 | 149 | |
c428ecd1 HX |
150 | static const struct rhashtable_params netlink_rhashtable_params; |
151 | ||
7e3ce05e MRL |
152 | void do_trace_netlink_extack(const char *msg) |
153 | { | |
154 | trace_netlink_extack(msg); | |
155 | } | |
156 | EXPORT_SYMBOL(do_trace_netlink_extack); | |
157 | ||
b57ef81f | 158 | static inline u32 netlink_group_mask(u32 group) |
d629b836 | 159 | { |
4a536b31 PM |
160 | if (group > 32) |
161 | return 0; | |
d629b836 PM |
162 | return group ? 1 << (group - 1) : 0; |
163 | } | |
164 | ||
1853c949 DB |
165 | static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
166 | gfp_t gfp_mask) | |
167 | { | |
168 | unsigned int len = skb_end_offset(skb); | |
169 | struct sk_buff *new; | |
170 | ||
171 | new = alloc_skb(len, gfp_mask); | |
172 | if (new == NULL) | |
173 | return NULL; | |
174 | ||
175 | NETLINK_CB(new).portid = NETLINK_CB(skb).portid; | |
176 | NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; | |
177 | NETLINK_CB(new).creds = NETLINK_CB(skb).creds; | |
178 | ||
59ae1d12 | 179 | skb_put_data(new, skb->data, len); |
1853c949 DB |
180 | return new; |
181 | } | |
182 | ||
25e3f70f CW |
183 | static unsigned int netlink_tap_net_id; |
184 | ||
185 | struct netlink_tap_net { | |
186 | struct list_head netlink_tap_all; | |
b1042d35 | 187 | struct mutex netlink_tap_lock; |
25e3f70f CW |
188 | }; |
189 | ||
bcbde0d4 DB |
190 | int netlink_add_tap(struct netlink_tap *nt) |
191 | { | |
25e3f70f CW |
192 | struct net *net = dev_net(nt->dev); |
193 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
194 | ||
bcbde0d4 DB |
195 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) |
196 | return -EINVAL; | |
197 | ||
b1042d35 | 198 | mutex_lock(&nn->netlink_tap_lock); |
25e3f70f | 199 | list_add_rcu(&nt->list, &nn->netlink_tap_all); |
b1042d35 | 200 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 201 | |
fcd4d35e | 202 | __module_get(nt->module); |
bcbde0d4 DB |
203 | |
204 | return 0; | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
207 | ||
2173f8d9 | 208 | static int __netlink_remove_tap(struct netlink_tap *nt) |
bcbde0d4 | 209 | { |
25e3f70f CW |
210 | struct net *net = dev_net(nt->dev); |
211 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
bcbde0d4 DB |
212 | bool found = false; |
213 | struct netlink_tap *tmp; | |
214 | ||
b1042d35 | 215 | mutex_lock(&nn->netlink_tap_lock); |
bcbde0d4 | 216 | |
25e3f70f | 217 | list_for_each_entry(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
218 | if (nt == tmp) { |
219 | list_del_rcu(&nt->list); | |
220 | found = true; | |
221 | goto out; | |
222 | } | |
223 | } | |
224 | ||
225 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
226 | out: | |
b1042d35 | 227 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 228 | |
92b80eb3 | 229 | if (found) |
bcbde0d4 DB |
230 | module_put(nt->module); |
231 | ||
232 | return found ? 0 : -ENODEV; | |
233 | } | |
bcbde0d4 DB |
234 | |
235 | int netlink_remove_tap(struct netlink_tap *nt) | |
236 | { | |
237 | int ret; | |
238 | ||
239 | ret = __netlink_remove_tap(nt); | |
240 | synchronize_net(); | |
241 | ||
242 | return ret; | |
243 | } | |
244 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
245 | ||
25e3f70f CW |
246 | static __net_init int netlink_tap_init_net(struct net *net) |
247 | { | |
248 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
249 | ||
250 | INIT_LIST_HEAD(&nn->netlink_tap_all); | |
b1042d35 | 251 | mutex_init(&nn->netlink_tap_lock); |
25e3f70f CW |
252 | return 0; |
253 | } | |
254 | ||
25e3f70f CW |
255 | static struct pernet_operations netlink_tap_net_ops = { |
256 | .init = netlink_tap_init_net, | |
25e3f70f CW |
257 | .id = &netlink_tap_net_id, |
258 | .size = sizeof(struct netlink_tap_net), | |
259 | }; | |
260 | ||
5ffd5cdd DB |
261 | static bool netlink_filter_tap(const struct sk_buff *skb) |
262 | { | |
263 | struct sock *sk = skb->sk; | |
5ffd5cdd DB |
264 | |
265 | /* We take the more conservative approach and | |
266 | * whitelist socket protocols that may pass. | |
267 | */ | |
268 | switch (sk->sk_protocol) { | |
269 | case NETLINK_ROUTE: | |
270 | case NETLINK_USERSOCK: | |
271 | case NETLINK_SOCK_DIAG: | |
272 | case NETLINK_NFLOG: | |
273 | case NETLINK_XFRM: | |
274 | case NETLINK_FIB_LOOKUP: | |
275 | case NETLINK_NETFILTER: | |
276 | case NETLINK_GENERIC: | |
498044bb | 277 | return true; |
5ffd5cdd DB |
278 | } |
279 | ||
498044bb | 280 | return false; |
5ffd5cdd DB |
281 | } |
282 | ||
bcbde0d4 DB |
283 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
284 | struct net_device *dev) | |
285 | { | |
286 | struct sk_buff *nskb; | |
5ffd5cdd | 287 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
288 | int ret = -ENOMEM; |
289 | ||
93c64764 KC |
290 | if (!net_eq(dev_net(dev), sock_net(sk))) |
291 | return 0; | |
292 | ||
bcbde0d4 | 293 | dev_hold(dev); |
1853c949 | 294 | |
d1b4c689 | 295 | if (is_vmalloc_addr(skb->head)) |
1853c949 DB |
296 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
297 | else | |
298 | nskb = skb_clone(skb, GFP_ATOMIC); | |
bcbde0d4 DB |
299 | if (nskb) { |
300 | nskb->dev = dev; | |
5ffd5cdd | 301 | nskb->protocol = htons((u16) sk->sk_protocol); |
604d13c9 DB |
302 | nskb->pkt_type = netlink_is_kernel(sk) ? |
303 | PACKET_KERNEL : PACKET_USER; | |
4e48ed88 | 304 | skb_reset_network_header(nskb); |
bcbde0d4 DB |
305 | ret = dev_queue_xmit(nskb); |
306 | if (unlikely(ret > 0)) | |
307 | ret = net_xmit_errno(ret); | |
308 | } | |
309 | ||
310 | dev_put(dev); | |
311 | return ret; | |
312 | } | |
313 | ||
25e3f70f | 314 | static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) |
bcbde0d4 DB |
315 | { |
316 | int ret; | |
317 | struct netlink_tap *tmp; | |
318 | ||
5ffd5cdd DB |
319 | if (!netlink_filter_tap(skb)) |
320 | return; | |
321 | ||
25e3f70f | 322 | list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
323 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); |
324 | if (unlikely(ret)) | |
325 | break; | |
326 | } | |
327 | } | |
328 | ||
25e3f70f | 329 | static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) |
bcbde0d4 | 330 | { |
25e3f70f CW |
331 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
332 | ||
bcbde0d4 DB |
333 | rcu_read_lock(); |
334 | ||
25e3f70f CW |
335 | if (unlikely(!list_empty(&nn->netlink_tap_all))) |
336 | __netlink_deliver_tap(skb, nn); | |
bcbde0d4 DB |
337 | |
338 | rcu_read_unlock(); | |
339 | } | |
340 | ||
73bfd370 DB |
341 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
342 | struct sk_buff *skb) | |
343 | { | |
344 | if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) | |
25e3f70f | 345 | netlink_deliver_tap(sock_net(dst), skb); |
73bfd370 DB |
346 | } |
347 | ||
cd1df525 PM |
348 | static void netlink_overrun(struct sock *sk) |
349 | { | |
350 | struct netlink_sock *nlk = nlk_sk(sk); | |
351 | ||
cc3a572f ND |
352 | if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { |
353 | if (!test_and_set_bit(NETLINK_S_CONGESTED, | |
354 | &nlk_sk(sk)->state)) { | |
cd1df525 | 355 | sk->sk_err = ENOBUFS; |
e3ae2365 | 356 | sk_error_report(sk); |
cd1df525 PM |
357 | } |
358 | } | |
359 | atomic_inc(&sk->sk_drops); | |
360 | } | |
361 | ||
362 | static void netlink_rcv_wake(struct sock *sk) | |
363 | { | |
364 | struct netlink_sock *nlk = nlk_sk(sk); | |
365 | ||
174bce38 | 366 | if (skb_queue_empty_lockless(&sk->sk_receive_queue)) |
cc3a572f ND |
367 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
368 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) | |
cd1df525 PM |
369 | wake_up_interruptible(&nlk->wait); |
370 | } | |
371 | ||
cf0a018a PM |
372 | static void netlink_skb_destructor(struct sk_buff *skb) |
373 | { | |
c05cdb1b | 374 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
375 | if (!skb->cloned || |
376 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
377 | vfree(skb->head); | |
378 | ||
c05cdb1b PNA |
379 | skb->head = NULL; |
380 | } | |
9652e931 PM |
381 | if (skb->sk != NULL) |
382 | sock_rfree(skb); | |
cf0a018a PM |
383 | } |
384 | ||
385 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
386 | { | |
387 | WARN_ON(skb->sk != NULL); | |
388 | skb->sk = sk; | |
389 | skb->destructor = netlink_skb_destructor; | |
390 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
391 | sk_mem_charge(sk, skb->truesize); | |
392 | } | |
393 | ||
ed5d7788 | 394 | static void netlink_sock_destruct(struct sock *sk) |
1da177e4 | 395 | { |
3f660d66 HX |
396 | struct netlink_sock *nlk = nlk_sk(sk); |
397 | ||
16b304f3 | 398 | if (nlk->cb_running) { |
ed5d7788 HX |
399 | if (nlk->cb.done) |
400 | nlk->cb.done(&nlk->cb); | |
16b304f3 PS |
401 | module_put(nlk->cb.module); |
402 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
403 | } |
404 | ||
1da177e4 LT |
405 | skb_queue_purge(&sk->sk_receive_queue); |
406 | ||
407 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 408 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
409 | return; |
410 | } | |
547b792c IJ |
411 | |
412 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
14afee4b | 413 | WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
547b792c | 414 | WARN_ON(nlk_sk(sk)->groups); |
1da177e4 LT |
415 | } |
416 | ||
707693c8 HX |
417 | static void netlink_sock_destruct_work(struct work_struct *work) |
418 | { | |
419 | struct netlink_sock *nlk = container_of(work, struct netlink_sock, | |
420 | work); | |
421 | ||
ed5d7788 | 422 | sk_free(&nlk->sk); |
707693c8 HX |
423 | } |
424 | ||
6ac552fd PM |
425 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
426 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
427 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
428 | * this, _but_ remember, it adds useless work on UP machines. | |
429 | */ | |
430 | ||
d136f1bd | 431 | void netlink_table_grab(void) |
9a429c49 | 432 | __acquires(nl_table_lock) |
1da177e4 | 433 | { |
d136f1bd JB |
434 | might_sleep(); |
435 | ||
6abd219c | 436 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
437 | |
438 | if (atomic_read(&nl_table_users)) { | |
439 | DECLARE_WAITQUEUE(wait, current); | |
440 | ||
441 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 442 | for (;;) { |
1da177e4 LT |
443 | set_current_state(TASK_UNINTERRUPTIBLE); |
444 | if (atomic_read(&nl_table_users) == 0) | |
445 | break; | |
6abd219c | 446 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 447 | schedule(); |
6abd219c | 448 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
449 | } |
450 | ||
451 | __set_current_state(TASK_RUNNING); | |
452 | remove_wait_queue(&nl_table_wait, &wait); | |
453 | } | |
454 | } | |
455 | ||
d136f1bd | 456 | void netlink_table_ungrab(void) |
9a429c49 | 457 | __releases(nl_table_lock) |
1da177e4 | 458 | { |
6abd219c | 459 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
460 | wake_up(&nl_table_wait); |
461 | } | |
462 | ||
6ac552fd | 463 | static inline void |
1da177e4 LT |
464 | netlink_lock_table(void) |
465 | { | |
1d482e66 JB |
466 | unsigned long flags; |
467 | ||
1da177e4 LT |
468 | /* read_lock() synchronizes us to netlink_table_grab */ |
469 | ||
1d482e66 | 470 | read_lock_irqsave(&nl_table_lock, flags); |
1da177e4 | 471 | atomic_inc(&nl_table_users); |
1d482e66 | 472 | read_unlock_irqrestore(&nl_table_lock, flags); |
1da177e4 LT |
473 | } |
474 | ||
6ac552fd | 475 | static inline void |
1da177e4 LT |
476 | netlink_unlock_table(void) |
477 | { | |
478 | if (atomic_dec_and_test(&nl_table_users)) | |
479 | wake_up(&nl_table_wait); | |
480 | } | |
481 | ||
e341694e | 482 | struct netlink_compare_arg |
1da177e4 | 483 | { |
c428ecd1 | 484 | possible_net_t pnet; |
e341694e TG |
485 | u32 portid; |
486 | }; | |
1da177e4 | 487 | |
8f2ddaac HX |
488 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
489 | #define netlink_compare_arg_len \ | |
490 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
491 | |
492 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
493 | const void *ptr) | |
1da177e4 | 494 | { |
c428ecd1 HX |
495 | const struct netlink_compare_arg *x = arg->key; |
496 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 497 | |
da314c99 | 498 | return nlk->portid != x->portid || |
c428ecd1 HX |
499 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
500 | } | |
501 | ||
502 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
503 | struct net *net, u32 portid) | |
504 | { | |
505 | memset(arg, 0, sizeof(*arg)); | |
506 | write_pnet(&arg->pnet, net); | |
507 | arg->portid = portid; | |
1da177e4 LT |
508 | } |
509 | ||
e341694e TG |
510 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
511 | struct net *net) | |
1da177e4 | 512 | { |
c428ecd1 | 513 | struct netlink_compare_arg arg; |
1da177e4 | 514 | |
c428ecd1 HX |
515 | netlink_compare_arg_init(&arg, net, portid); |
516 | return rhashtable_lookup_fast(&table->hash, &arg, | |
517 | netlink_rhashtable_params); | |
1da177e4 LT |
518 | } |
519 | ||
c428ecd1 | 520 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 521 | { |
c428ecd1 | 522 | struct netlink_compare_arg arg; |
c5adde94 | 523 | |
da314c99 | 524 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
525 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
526 | &nlk_sk(sk)->node, | |
527 | netlink_rhashtable_params); | |
c5adde94 YX |
528 | } |
529 | ||
e341694e | 530 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 531 | { |
e341694e TG |
532 | struct netlink_table *table = &nl_table[protocol]; |
533 | struct sock *sk; | |
1da177e4 | 534 | |
e341694e TG |
535 | rcu_read_lock(); |
536 | sk = __netlink_lookup(table, portid, net); | |
537 | if (sk) | |
538 | sock_hold(sk); | |
539 | rcu_read_unlock(); | |
1da177e4 | 540 | |
e341694e | 541 | return sk; |
1da177e4 LT |
542 | } |
543 | ||
90ddc4f0 | 544 | static const struct proto_ops netlink_ops; |
1da177e4 | 545 | |
4277a083 PM |
546 | static void |
547 | netlink_update_listeners(struct sock *sk) | |
548 | { | |
549 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
550 | unsigned long mask; |
551 | unsigned int i; | |
6d772ac5 ED |
552 | struct listeners *listeners; |
553 | ||
554 | listeners = nl_deref_protected(tbl->listeners); | |
555 | if (!listeners) | |
556 | return; | |
4277a083 | 557 | |
b4ff4f04 | 558 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 559 | mask = 0; |
b67bfe0d | 560 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
561 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
562 | mask |= nlk_sk(sk)->groups[i]; | |
563 | } | |
6d772ac5 | 564 | listeners->masks[i] = mask; |
4277a083 PM |
565 | } |
566 | /* this function is only called with the netlink table "grabbed", which | |
567 | * makes sure updates are visible before bind or setsockopt return. */ | |
568 | } | |
569 | ||
8ea65f4a | 570 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 571 | { |
da12c90e | 572 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 573 | int err; |
1da177e4 | 574 | |
c5adde94 | 575 | lock_sock(sk); |
1da177e4 | 576 | |
da314c99 HX |
577 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
578 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
579 | goto err; |
580 | ||
da314c99 | 581 | nlk_sk(sk)->portid = portid; |
e341694e | 582 | sock_hold(sk); |
919d9db9 | 583 | |
c428ecd1 HX |
584 | err = __netlink_insert(table, sk); |
585 | if (err) { | |
4e7c1330 DB |
586 | /* In case the hashtable backend returns with -EBUSY |
587 | * from here, it must not escape to the caller. | |
588 | */ | |
589 | if (unlikely(err == -EBUSY)) | |
590 | err = -EOVERFLOW; | |
c428ecd1 HX |
591 | if (err == -EEXIST) |
592 | err = -EADDRINUSE; | |
c5adde94 | 593 | sock_put(sk); |
1f770c0a | 594 | goto err; |
919d9db9 HX |
595 | } |
596 | ||
da314c99 HX |
597 | /* We need to ensure that the socket is hashed and visible. */ |
598 | smp_wmb(); | |
7707a4d0 ED |
599 | /* Paired with lockless reads from netlink_bind(), |
600 | * netlink_connect() and netlink_sendmsg(). | |
601 | */ | |
602 | WRITE_ONCE(nlk_sk(sk)->bound, portid); | |
1f770c0a | 603 | |
1da177e4 | 604 | err: |
c5adde94 | 605 | release_sock(sk); |
1da177e4 LT |
606 | return err; |
607 | } | |
608 | ||
609 | static void netlink_remove(struct sock *sk) | |
610 | { | |
e341694e TG |
611 | struct netlink_table *table; |
612 | ||
e341694e | 613 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
614 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
615 | netlink_rhashtable_params)) { | |
41c6d650 | 616 | WARN_ON(refcount_read(&sk->sk_refcnt) == 1); |
e341694e TG |
617 | __sock_put(sk); |
618 | } | |
e341694e | 619 | |
1da177e4 | 620 | netlink_table_grab(); |
b10dcb3b | 621 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 622 | __sk_del_bind_node(sk); |
b10dcb3b JB |
623 | netlink_update_listeners(sk); |
624 | } | |
ee1c2442 JB |
625 | if (sk->sk_protocol == NETLINK_GENERIC) |
626 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
627 | netlink_table_ungrab(); |
628 | } | |
629 | ||
630 | static struct proto netlink_proto = { | |
631 | .name = "NETLINK", | |
632 | .owner = THIS_MODULE, | |
633 | .obj_size = sizeof(struct netlink_sock), | |
634 | }; | |
635 | ||
1b8d7ae4 | 636 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
637 | struct mutex *cb_mutex, int protocol, |
638 | int kern) | |
1da177e4 LT |
639 | { |
640 | struct sock *sk; | |
641 | struct netlink_sock *nlk; | |
ab33a171 PM |
642 | |
643 | sock->ops = &netlink_ops; | |
644 | ||
11aa9c28 | 645 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
646 | if (!sk) |
647 | return -ENOMEM; | |
648 | ||
649 | sock_init_data(sock, sk); | |
650 | ||
651 | nlk = nlk_sk(sk); | |
658cb354 | 652 | if (cb_mutex) { |
ffa4d721 | 653 | nlk->cb_mutex = cb_mutex; |
658cb354 | 654 | } else { |
ffa4d721 PM |
655 | nlk->cb_mutex = &nlk->cb_def_mutex; |
656 | mutex_init(nlk->cb_mutex); | |
8a0f5ccf HX |
657 | lockdep_set_class_and_name(nlk->cb_mutex, |
658 | nlk_cb_mutex_keys + protocol, | |
659 | nlk_cb_mutex_key_strings[protocol]); | |
ffa4d721 | 660 | } |
ab33a171 PM |
661 | init_waitqueue_head(&nlk->wait); |
662 | ||
663 | sk->sk_destruct = netlink_sock_destruct; | |
664 | sk->sk_protocol = protocol; | |
665 | return 0; | |
666 | } | |
667 | ||
3f378b68 EP |
668 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
669 | int kern) | |
ab33a171 PM |
670 | { |
671 | struct module *module = NULL; | |
af65bdfc | 672 | struct mutex *cb_mutex; |
f7fa9b10 | 673 | struct netlink_sock *nlk; |
023e2cfa JB |
674 | int (*bind)(struct net *net, int group); |
675 | void (*unbind)(struct net *net, int group); | |
ab33a171 | 676 | int err = 0; |
1da177e4 LT |
677 | |
678 | sock->state = SS_UNCONNECTED; | |
679 | ||
680 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
681 | return -ESOCKTNOSUPPORT; | |
682 | ||
6ac552fd | 683 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 | 684 | return -EPROTONOSUPPORT; |
bc5b6c0b | 685 | protocol = array_index_nospec(protocol, MAX_LINKS); |
1da177e4 | 686 | |
77247bbb | 687 | netlink_lock_table(); |
95a5afca | 688 | #ifdef CONFIG_MODULES |
ab33a171 | 689 | if (!nl_table[protocol].registered) { |
77247bbb | 690 | netlink_unlock_table(); |
4fdb3bb7 | 691 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 692 | netlink_lock_table(); |
4fdb3bb7 | 693 | } |
ab33a171 PM |
694 | #endif |
695 | if (nl_table[protocol].registered && | |
696 | try_module_get(nl_table[protocol].module)) | |
697 | module = nl_table[protocol].module; | |
974c37e9 AD |
698 | else |
699 | err = -EPROTONOSUPPORT; | |
af65bdfc | 700 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 701 | bind = nl_table[protocol].bind; |
4f520900 | 702 | unbind = nl_table[protocol].unbind; |
77247bbb | 703 | netlink_unlock_table(); |
4fdb3bb7 | 704 | |
974c37e9 AD |
705 | if (err < 0) |
706 | goto out; | |
707 | ||
11aa9c28 | 708 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 709 | if (err < 0) |
f7fa9b10 PM |
710 | goto out_module; |
711 | ||
6f756a8c | 712 | local_bh_disable(); |
c1fd3b94 | 713 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
714 | local_bh_enable(); |
715 | ||
f7fa9b10 | 716 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 717 | nlk->module = module; |
03292745 | 718 | nlk->netlink_bind = bind; |
4f520900 | 719 | nlk->netlink_unbind = unbind; |
ab33a171 PM |
720 | out: |
721 | return err; | |
1da177e4 | 722 | |
ab33a171 PM |
723 | out_module: |
724 | module_put(module); | |
725 | goto out; | |
1da177e4 LT |
726 | } |
727 | ||
21e4902a TG |
728 | static void deferred_put_nlk_sk(struct rcu_head *head) |
729 | { | |
730 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
ed5d7788 HX |
731 | struct sock *sk = &nlk->sk; |
732 | ||
be82485f XL |
733 | kfree(nlk->groups); |
734 | nlk->groups = NULL; | |
735 | ||
41c6d650 | 736 | if (!refcount_dec_and_test(&sk->sk_refcnt)) |
ed5d7788 HX |
737 | return; |
738 | ||
739 | if (nlk->cb_running && nlk->cb.done) { | |
740 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); | |
741 | schedule_work(&nlk->work); | |
742 | return; | |
743 | } | |
21e4902a | 744 | |
ed5d7788 | 745 | sk_free(sk); |
21e4902a TG |
746 | } |
747 | ||
1da177e4 LT |
748 | static int netlink_release(struct socket *sock) |
749 | { | |
750 | struct sock *sk = sock->sk; | |
751 | struct netlink_sock *nlk; | |
752 | ||
753 | if (!sk) | |
754 | return 0; | |
755 | ||
756 | netlink_remove(sk); | |
ac57b3a9 | 757 | sock_orphan(sk); |
1da177e4 LT |
758 | nlk = nlk_sk(sk); |
759 | ||
3f660d66 HX |
760 | /* |
761 | * OK. Socket is unlinked, any packets that arrive now | |
762 | * will be purged. | |
763 | */ | |
1da177e4 | 764 | |
ee1c2442 JB |
765 | /* must not acquire netlink_table_lock in any way again before unbind |
766 | * and notifying genetlink is done as otherwise it might deadlock | |
767 | */ | |
768 | if (nlk->netlink_unbind) { | |
769 | int i; | |
770 | ||
771 | for (i = 0; i < nlk->ngroups; i++) | |
772 | if (test_bit(i, nlk->groups)) | |
773 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
774 | } | |
775 | if (sk->sk_protocol == NETLINK_GENERIC && | |
776 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
777 | wake_up(&genl_sk_destructing_waitq); | |
778 | ||
1da177e4 LT |
779 | sock->sk = NULL; |
780 | wake_up_interruptible_all(&nlk->wait); | |
781 | ||
782 | skb_queue_purge(&sk->sk_write_queue); | |
783 | ||
e2726020 | 784 | if (nlk->portid && nlk->bound) { |
1da177e4 | 785 | struct netlink_notify n = { |
3b1e0a65 | 786 | .net = sock_net(sk), |
1da177e4 | 787 | .protocol = sk->sk_protocol, |
15e47304 | 788 | .portid = nlk->portid, |
1da177e4 | 789 | }; |
efa172f4 | 790 | blocking_notifier_call_chain(&netlink_chain, |
e041c683 | 791 | NETLINK_URELEASE, &n); |
746fac4d | 792 | } |
4fdb3bb7 | 793 | |
5e7c001c | 794 | module_put(nlk->module); |
4fdb3bb7 | 795 | |
aed81560 | 796 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 797 | netlink_table_grab(); |
869e58f8 DL |
798 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
799 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
800 | struct listeners *old; |
801 | ||
802 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
803 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
804 | kfree_rcu(old, rcu); | |
869e58f8 | 805 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 806 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 807 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 808 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
809 | nl_table[sk->sk_protocol].registered = 0; |
810 | } | |
b10dcb3b | 811 | netlink_table_ungrab(); |
658cb354 | 812 | } |
77247bbb | 813 | |
3755810c | 814 | local_bh_disable(); |
c1fd3b94 | 815 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 816 | local_bh_enable(); |
21e4902a | 817 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
818 | return 0; |
819 | } | |
820 | ||
821 | static int netlink_autobind(struct socket *sock) | |
822 | { | |
823 | struct sock *sk = sock->sk; | |
3b1e0a65 | 824 | struct net *net = sock_net(sk); |
da12c90e | 825 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 826 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 827 | int err; |
b9fbe709 HX |
828 | s32 rover = -4096; |
829 | bool ok; | |
1da177e4 LT |
830 | |
831 | retry: | |
832 | cond_resched(); | |
e341694e | 833 | rcu_read_lock(); |
b9fbe709 HX |
834 | ok = !__netlink_lookup(table, portid, net); |
835 | rcu_read_unlock(); | |
836 | if (!ok) { | |
e341694e | 837 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
838 | if (rover == -4096) |
839 | /* rover will be in range [S32_MIN, -4097] */ | |
840 | rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); | |
841 | else if (rover >= -4096) | |
e341694e | 842 | rover = -4097; |
b9fbe709 | 843 | portid = rover--; |
e341694e | 844 | goto retry; |
1da177e4 | 845 | } |
1da177e4 | 846 | |
8ea65f4a | 847 | err = netlink_insert(sk, portid); |
1da177e4 LT |
848 | if (err == -EADDRINUSE) |
849 | goto retry; | |
d470e3b4 DM |
850 | |
851 | /* If 2 threads race to autobind, that is fine. */ | |
852 | if (err == -EBUSY) | |
853 | err = 0; | |
854 | ||
855 | return err; | |
1da177e4 LT |
856 | } |
857 | ||
aa4cf945 EB |
858 | /** |
859 | * __netlink_ns_capable - General netlink message capability test | |
860 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. | |
861 | * @user_ns: The user namespace of the capability to use | |
862 | * @cap: The capability to use | |
863 | * | |
864 | * Test to see if the opener of the socket we received the message | |
865 | * from had when the netlink socket was created and the sender of the | |
85405918 | 866 | * message has the capability @cap in the user namespace @user_ns. |
aa4cf945 EB |
867 | */ |
868 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, | |
869 | struct user_namespace *user_ns, int cap) | |
870 | { | |
2d7a85f4 EB |
871 | return ((nsp->flags & NETLINK_SKB_DST) || |
872 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
873 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
874 | } |
875 | EXPORT_SYMBOL(__netlink_ns_capable); | |
876 | ||
877 | /** | |
878 | * netlink_ns_capable - General netlink message capability test | |
879 | * @skb: socket buffer holding a netlink command from userspace | |
880 | * @user_ns: The user namespace of the capability to use | |
881 | * @cap: The capability to use | |
882 | * | |
883 | * Test to see if the opener of the socket we received the message | |
884 | * from had when the netlink socket was created and the sender of the | |
85405918 | 885 | * message has the capability @cap in the user namespace @user_ns. |
aa4cf945 EB |
886 | */ |
887 | bool netlink_ns_capable(const struct sk_buff *skb, | |
888 | struct user_namespace *user_ns, int cap) | |
889 | { | |
890 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
891 | } | |
892 | EXPORT_SYMBOL(netlink_ns_capable); | |
893 | ||
894 | /** | |
895 | * netlink_capable - Netlink global message capability test | |
896 | * @skb: socket buffer holding a netlink command from userspace | |
897 | * @cap: The capability to use | |
898 | * | |
899 | * Test to see if the opener of the socket we received the message | |
900 | * from had when the netlink socket was created and the sender of the | |
85405918 | 901 | * message has the capability @cap in all user namespaces. |
aa4cf945 EB |
902 | */ |
903 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
904 | { | |
905 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
906 | } | |
907 | EXPORT_SYMBOL(netlink_capable); | |
908 | ||
909 | /** | |
910 | * netlink_net_capable - Netlink network namespace message capability test | |
911 | * @skb: socket buffer holding a netlink command from userspace | |
912 | * @cap: The capability to use | |
913 | * | |
914 | * Test to see if the opener of the socket we received the message | |
915 | * from had when the netlink socket was created and the sender of the | |
85405918 | 916 | * message has the capability @cap over the network namespace of |
aa4cf945 EB |
917 | * the socket we received the message from. |
918 | */ | |
919 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
920 | { | |
921 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
922 | } | |
923 | EXPORT_SYMBOL(netlink_net_capable); | |
924 | ||
5187cd05 | 925 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 926 | { |
9785e10a | 927 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 928 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 929 | } |
1da177e4 | 930 | |
f7fa9b10 PM |
931 | static void |
932 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
933 | { | |
934 | struct netlink_sock *nlk = nlk_sk(sk); | |
935 | ||
936 | if (nlk->subscriptions && !subscriptions) | |
937 | __sk_del_bind_node(sk); | |
938 | else if (!nlk->subscriptions && subscriptions) | |
939 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
940 | nlk->subscriptions = subscriptions; | |
941 | } | |
942 | ||
b4ff4f04 | 943 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
944 | { |
945 | struct netlink_sock *nlk = nlk_sk(sk); | |
946 | unsigned int groups; | |
b4ff4f04 | 947 | unsigned long *new_groups; |
513c2500 PM |
948 | int err = 0; |
949 | ||
b4ff4f04 JB |
950 | netlink_table_grab(); |
951 | ||
513c2500 | 952 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 953 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 954 | err = -ENOENT; |
b4ff4f04 JB |
955 | goto out_unlock; |
956 | } | |
513c2500 | 957 | |
b4ff4f04 JB |
958 | if (nlk->ngroups >= groups) |
959 | goto out_unlock; | |
513c2500 | 960 | |
b4ff4f04 JB |
961 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
962 | if (new_groups == NULL) { | |
963 | err = -ENOMEM; | |
964 | goto out_unlock; | |
965 | } | |
6ac552fd | 966 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
967 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
968 | ||
969 | nlk->groups = new_groups; | |
513c2500 | 970 | nlk->ngroups = groups; |
b4ff4f04 JB |
971 | out_unlock: |
972 | netlink_table_ungrab(); | |
973 | return err; | |
513c2500 PM |
974 | } |
975 | ||
02c81ab9 | 976 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 977 | struct sock *sk) |
4f520900 | 978 | { |
023e2cfa | 979 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
980 | int undo; |
981 | ||
982 | if (!nlk->netlink_unbind) | |
983 | return; | |
984 | ||
985 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 986 | if (test_bit(undo, &groups)) |
8b7c36d8 | 987 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
988 | } |
989 | ||
6ac552fd PM |
990 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
991 | int addr_len) | |
1da177e4 LT |
992 | { |
993 | struct sock *sk = sock->sk; | |
3b1e0a65 | 994 | struct net *net = sock_net(sk); |
1da177e4 LT |
995 | struct netlink_sock *nlk = nlk_sk(sk); |
996 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
f7736080 | 997 | int err = 0; |
d852be84 | 998 | unsigned long groups; |
da314c99 | 999 | bool bound; |
746fac4d | 1000 | |
4e4b5376 HFS |
1001 | if (addr_len < sizeof(struct sockaddr_nl)) |
1002 | return -EINVAL; | |
1003 | ||
1da177e4 LT |
1004 | if (nladdr->nl_family != AF_NETLINK) |
1005 | return -EINVAL; | |
d852be84 | 1006 | groups = nladdr->nl_groups; |
1da177e4 LT |
1007 | |
1008 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 1009 | if (groups) { |
5187cd05 | 1010 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 1011 | return -EPERM; |
b4ff4f04 JB |
1012 | err = netlink_realloc_groups(sk); |
1013 | if (err) | |
1014 | return err; | |
513c2500 | 1015 | } |
1da177e4 | 1016 | |
428f944b | 1017 | if (nlk->ngroups < BITS_PER_LONG) |
91874ecf | 1018 | groups &= (1UL << nlk->ngroups) - 1; |
1da177e4 | 1019 | |
7707a4d0 ED |
1020 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1021 | bound = READ_ONCE(nlk->bound); | |
da314c99 HX |
1022 | if (bound) { |
1023 | /* Ensure nlk->portid is up-to-date. */ | |
1024 | smp_rmb(); | |
1025 | ||
15e47304 | 1026 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 1027 | return -EINVAL; |
da314c99 | 1028 | } |
4f520900 RGB |
1029 | |
1030 | if (nlk->netlink_bind && groups) { | |
1031 | int group; | |
1032 | ||
3a20773b NA |
1033 | /* nl_groups is a u32, so cap the maximum groups we can bind */ |
1034 | for (group = 0; group < BITS_PER_TYPE(u32); group++) { | |
4f520900 RGB |
1035 | if (!test_bit(group, &groups)) |
1036 | continue; | |
8b7c36d8 | 1037 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
1038 | if (!err) |
1039 | continue; | |
023e2cfa | 1040 | netlink_undo_bind(group, groups, sk); |
f2764bd4 | 1041 | return err; |
4f520900 RGB |
1042 | } |
1043 | } | |
1044 | ||
da314c99 HX |
1045 | /* No need for barriers here as we return to user-space without |
1046 | * using any of the bound attributes. | |
1047 | */ | |
f2764bd4 | 1048 | netlink_lock_table(); |
da314c99 | 1049 | if (!bound) { |
1da177e4 | 1050 | err = nladdr->nl_pid ? |
8ea65f4a | 1051 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 1052 | netlink_autobind(sock); |
4f520900 | 1053 | if (err) { |
3a20773b | 1054 | netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); |
f7736080 | 1055 | goto unlock; |
4f520900 | 1056 | } |
1da177e4 LT |
1057 | } |
1058 | ||
4f520900 | 1059 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
f7736080 XL |
1060 | goto unlock; |
1061 | netlink_unlock_table(); | |
1da177e4 LT |
1062 | |
1063 | netlink_table_grab(); | |
f7fa9b10 | 1064 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 1065 | hweight32(groups) - |
746fac4d | 1066 | hweight32(nlk->groups[0])); |
4f520900 | 1067 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 1068 | netlink_update_listeners(sk); |
1da177e4 LT |
1069 | netlink_table_ungrab(); |
1070 | ||
1071 | return 0; | |
f7736080 XL |
1072 | |
1073 | unlock: | |
1074 | netlink_unlock_table(); | |
1075 | return err; | |
1da177e4 LT |
1076 | } |
1077 | ||
1078 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
1079 | int alen, int flags) | |
1080 | { | |
1081 | int err = 0; | |
1082 | struct sock *sk = sock->sk; | |
1083 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1084 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1085 | |
6503d961 CG |
1086 | if (alen < sizeof(addr->sa_family)) |
1087 | return -EINVAL; | |
1088 | ||
1da177e4 LT |
1089 | if (addr->sa_family == AF_UNSPEC) { |
1090 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 1091 | nlk->dst_portid = 0; |
d629b836 | 1092 | nlk->dst_group = 0; |
1da177e4 LT |
1093 | return 0; |
1094 | } | |
1095 | if (addr->sa_family != AF_NETLINK) | |
1096 | return -EINVAL; | |
1097 | ||
78802879 AP |
1098 | if (alen < sizeof(struct sockaddr_nl)) |
1099 | return -EINVAL; | |
1100 | ||
46833a86 | 1101 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 1102 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1103 | return -EPERM; |
1104 | ||
da314c99 HX |
1105 | /* No need for barriers here as we return to user-space without |
1106 | * using any of the bound attributes. | |
7707a4d0 | 1107 | * Paired with WRITE_ONCE() in netlink_insert(). |
da314c99 | 1108 | */ |
7707a4d0 | 1109 | if (!READ_ONCE(nlk->bound)) |
1da177e4 LT |
1110 | err = netlink_autobind(sock); |
1111 | ||
1112 | if (err == 0) { | |
1113 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1114 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1115 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1116 | } |
1117 | ||
1118 | return err; | |
1119 | } | |
1120 | ||
6ac552fd | 1121 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
9b2c45d4 | 1122 | int peer) |
1da177e4 LT |
1123 | { |
1124 | struct sock *sk = sock->sk; | |
1125 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1126 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1127 | |
1da177e4 LT |
1128 | nladdr->nl_family = AF_NETLINK; |
1129 | nladdr->nl_pad = 0; | |
1da177e4 LT |
1130 | |
1131 | if (peer) { | |
15e47304 | 1132 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1133 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1134 | } else { |
15e47304 | 1135 | nladdr->nl_pid = nlk->portid; |
f7736080 | 1136 | netlink_lock_table(); |
513c2500 | 1137 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
f7736080 | 1138 | netlink_unlock_table(); |
1da177e4 | 1139 | } |
9b2c45d4 | 1140 | return sizeof(*nladdr); |
1da177e4 LT |
1141 | } |
1142 | ||
025c6818 DD |
1143 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1144 | unsigned long arg) | |
1145 | { | |
1146 | /* try to hand this ioctl down to the NIC drivers. | |
1147 | */ | |
1148 | return -ENOIOCTLCMD; | |
1149 | } | |
1150 | ||
15e47304 | 1151 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1152 | { |
1da177e4 LT |
1153 | struct sock *sock; |
1154 | struct netlink_sock *nlk; | |
1155 | ||
15e47304 | 1156 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1157 | if (!sock) |
1158 | return ERR_PTR(-ECONNREFUSED); | |
1159 | ||
1160 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1161 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1162 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1163 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1164 | sock_put(sock); |
1165 | return ERR_PTR(-ECONNREFUSED); | |
1166 | } | |
1167 | return sock; | |
1168 | } | |
1169 | ||
1170 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1171 | { | |
496ad9aa | 1172 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1173 | struct sock *sock; |
1174 | ||
1175 | if (!S_ISSOCK(inode->i_mode)) | |
1176 | return ERR_PTR(-ENOTSOCK); | |
1177 | ||
1178 | sock = SOCKET_I(inode)->sk; | |
1179 | if (sock->sk_family != AF_NETLINK) | |
1180 | return ERR_PTR(-EINVAL); | |
1181 | ||
1182 | sock_hold(sock); | |
1183 | return sock; | |
1184 | } | |
1185 | ||
3a36515f PN |
1186 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1187 | int broadcast) | |
c05cdb1b PNA |
1188 | { |
1189 | struct sk_buff *skb; | |
1190 | void *data; | |
1191 | ||
3a36515f | 1192 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1193 | return alloc_skb(size, GFP_KERNEL); |
1194 | ||
3a36515f PN |
1195 | size = SKB_DATA_ALIGN(size) + |
1196 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1197 | |
1198 | data = vmalloc(size); | |
1199 | if (data == NULL) | |
3a36515f | 1200 | return NULL; |
c05cdb1b | 1201 | |
2ea2f62c | 1202 | skb = __build_skb(data, size); |
3a36515f PN |
1203 | if (skb == NULL) |
1204 | vfree(data); | |
2ea2f62c | 1205 | else |
3a36515f | 1206 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1207 | |
1208 | return skb; | |
c05cdb1b PNA |
1209 | } |
1210 | ||
1da177e4 LT |
1211 | /* |
1212 | * Attach a skb to a netlink socket. | |
1213 | * The caller must hold a reference to the destination socket. On error, the | |
1214 | * reference is dropped. The skb is not send to the destination, just all | |
1215 | * all error checks are performed and memory in the queue is reserved. | |
1216 | * Return values: | |
1217 | * < 0: error. skb freed, reference to sock dropped. | |
1218 | * 0: continue | |
1219 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1220 | */ | |
9457afee | 1221 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1222 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1223 | { |
1224 | struct netlink_sock *nlk; | |
1225 | ||
1226 | nlk = nlk_sk(sk); | |
1227 | ||
5fd96123 | 1228 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1229 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1230 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1231 | if (!*timeo) { |
aed81560 | 1232 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1233 | netlink_overrun(sk); |
1234 | sock_put(sk); | |
1235 | kfree_skb(skb); | |
1236 | return -EAGAIN; | |
1237 | } | |
1238 | ||
1239 | __set_current_state(TASK_INTERRUPTIBLE); | |
1240 | add_wait_queue(&nlk->wait, &wait); | |
1241 | ||
1242 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1243 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1244 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1245 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1246 | |
1247 | __set_current_state(TASK_RUNNING); | |
1248 | remove_wait_queue(&nlk->wait, &wait); | |
1249 | sock_put(sk); | |
1250 | ||
1251 | if (signal_pending(current)) { | |
1252 | kfree_skb(skb); | |
c3d8d1e3 | 1253 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1254 | } |
1255 | return 1; | |
1256 | } | |
cf0a018a | 1257 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1258 | return 0; |
1259 | } | |
1260 | ||
4a7e7c2a | 1261 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1262 | { |
1da177e4 LT |
1263 | int len = skb->len; |
1264 | ||
25e3f70f | 1265 | netlink_deliver_tap(sock_net(sk), skb); |
bcbde0d4 | 1266 | |
d1b4c689 | 1267 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1268 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1269 | return len; |
1270 | } | |
1271 | ||
1272 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1273 | { | |
1274 | int len = __netlink_sendskb(sk, skb); | |
1275 | ||
1da177e4 LT |
1276 | sock_put(sk); |
1277 | return len; | |
1278 | } | |
1279 | ||
1280 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1281 | { | |
1282 | kfree_skb(skb); | |
1283 | sock_put(sk); | |
1284 | } | |
1285 | ||
b57ef81f | 1286 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1287 | { |
1288 | int delta; | |
1289 | ||
1298ca46 | 1290 | WARN_ON(skb->sk != NULL); |
4305b541 | 1291 | delta = skb->end - skb->tail; |
c05cdb1b | 1292 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1293 | return skb; |
1294 | ||
1295 | if (skb_shared(skb)) { | |
1296 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1297 | if (!nskb) | |
1298 | return skb; | |
8460c00f | 1299 | consume_skb(skb); |
1da177e4 LT |
1300 | skb = nskb; |
1301 | } | |
1302 | ||
158f323b ED |
1303 | pskb_expand_head(skb, 0, -delta, |
1304 | (allocation & ~__GFP_DIRECT_RECLAIM) | | |
1305 | __GFP_NOWARN | __GFP_NORETRY); | |
1da177e4 LT |
1306 | return skb; |
1307 | } | |
1308 | ||
3fbc2905 EB |
1309 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1310 | struct sock *ssk) | |
cd40b7d3 DL |
1311 | { |
1312 | int ret; | |
1313 | struct netlink_sock *nlk = nlk_sk(sk); | |
1314 | ||
1315 | ret = -ECONNREFUSED; | |
1316 | if (nlk->netlink_rcv != NULL) { | |
1317 | ret = skb->len; | |
cf0a018a | 1318 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1319 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1320 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1321 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1322 | consume_skb(skb); |
1323 | } else { | |
1324 | kfree_skb(skb); | |
cd40b7d3 | 1325 | } |
cd40b7d3 DL |
1326 | sock_put(sk); |
1327 | return ret; | |
1328 | } | |
1329 | ||
1330 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1331 | u32 portid, int nonblock) |
1da177e4 LT |
1332 | { |
1333 | struct sock *sk; | |
1334 | int err; | |
1335 | long timeo; | |
1336 | ||
1337 | skb = netlink_trim(skb, gfp_any()); | |
1338 | ||
1339 | timeo = sock_sndtimeo(ssk, nonblock); | |
1340 | retry: | |
15e47304 | 1341 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1342 | if (IS_ERR(sk)) { |
1343 | kfree_skb(skb); | |
1344 | return PTR_ERR(sk); | |
1345 | } | |
cd40b7d3 | 1346 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1347 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1348 | |
b1153f29 | 1349 | if (sk_filter(sk, skb)) { |
84874607 | 1350 | err = skb->len; |
b1153f29 SH |
1351 | kfree_skb(skb); |
1352 | sock_put(sk); | |
1353 | return err; | |
1354 | } | |
1355 | ||
9457afee | 1356 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1357 | if (err == 1) |
1358 | goto retry; | |
1359 | if (err) | |
1360 | return err; | |
1361 | ||
7ee015e0 | 1362 | return netlink_sendskb(sk, skb); |
1da177e4 | 1363 | } |
6ac552fd | 1364 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1365 | |
4277a083 PM |
1366 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1367 | { | |
1368 | int res = 0; | |
5c398dc8 | 1369 | struct listeners *listeners; |
4277a083 | 1370 | |
aed81560 | 1371 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1372 | |
1373 | rcu_read_lock(); | |
1374 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1375 | ||
6d772ac5 | 1376 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1377 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1378 | |
1379 | rcu_read_unlock(); | |
1380 | ||
4277a083 PM |
1381 | return res; |
1382 | } | |
1383 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1384 | ||
59c28058 JK |
1385 | bool netlink_strict_get_check(struct sk_buff *skb) |
1386 | { | |
1387 | const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk); | |
1388 | ||
1389 | return nlk->flags & NETLINK_F_STRICT_CHK; | |
1390 | } | |
1391 | EXPORT_SYMBOL_GPL(netlink_strict_get_check); | |
1392 | ||
b57ef81f | 1393 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1394 | { |
1395 | struct netlink_sock *nlk = nlk_sk(sk); | |
1396 | ||
1397 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1398 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1399 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1400 | __netlink_sendskb(sk, skb); |
2c645800 | 1401 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1402 | } |
1403 | return -1; | |
1404 | } | |
1405 | ||
1406 | struct netlink_broadcast_data { | |
1407 | struct sock *exclude_sk; | |
b4b51029 | 1408 | struct net *net; |
15e47304 | 1409 | u32 portid; |
1da177e4 LT |
1410 | u32 group; |
1411 | int failure; | |
ff491a73 | 1412 | int delivery_failure; |
1da177e4 LT |
1413 | int congested; |
1414 | int delivered; | |
7d877f3b | 1415 | gfp_t allocation; |
1da177e4 | 1416 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1417 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1418 | void *tx_data; | |
1da177e4 LT |
1419 | }; |
1420 | ||
46c9521f RR |
1421 | static void do_one_broadcast(struct sock *sk, |
1422 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1423 | { |
1424 | struct netlink_sock *nlk = nlk_sk(sk); | |
1425 | int val; | |
1426 | ||
1427 | if (p->exclude_sk == sk) | |
46c9521f | 1428 | return; |
1da177e4 | 1429 | |
15e47304 | 1430 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1431 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1432 | return; |
1da177e4 | 1433 | |
59324cf3 ND |
1434 | if (!net_eq(sock_net(sk), p->net)) { |
1435 | if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) | |
1436 | return; | |
1437 | ||
1438 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1439 | return; | |
1440 | ||
1441 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1442 | CAP_NET_BROADCAST)) | |
1443 | return; | |
1444 | } | |
b4b51029 | 1445 | |
1da177e4 LT |
1446 | if (p->failure) { |
1447 | netlink_overrun(sk); | |
46c9521f | 1448 | return; |
1da177e4 LT |
1449 | } |
1450 | ||
1451 | sock_hold(sk); | |
1452 | if (p->skb2 == NULL) { | |
68acc024 | 1453 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1454 | p->skb2 = skb_clone(p->skb, p->allocation); |
1455 | } else { | |
68acc024 TC |
1456 | p->skb2 = skb_get(p->skb); |
1457 | /* | |
1458 | * skb ownership may have been set when | |
1459 | * delivered to a previous socket. | |
1460 | */ | |
1461 | skb_orphan(p->skb2); | |
1da177e4 LT |
1462 | } |
1463 | } | |
1464 | if (p->skb2 == NULL) { | |
1465 | netlink_overrun(sk); | |
1466 | /* Clone failed. Notify ALL listeners. */ | |
1467 | p->failure = 1; | |
cc3a572f | 1468 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1469 | p->delivery_failure = 1; |
59324cf3 ND |
1470 | goto out; |
1471 | } | |
1472 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
910a7e90 EB |
1473 | kfree_skb(p->skb2); |
1474 | p->skb2 = NULL; | |
59324cf3 ND |
1475 | goto out; |
1476 | } | |
1477 | if (sk_filter(sk, p->skb2)) { | |
b1153f29 SH |
1478 | kfree_skb(p->skb2); |
1479 | p->skb2 = NULL; | |
59324cf3 ND |
1480 | goto out; |
1481 | } | |
1482 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
7212462f ND |
1483 | if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) |
1484 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
59324cf3 ND |
1485 | val = netlink_broadcast_deliver(sk, p->skb2); |
1486 | if (val < 0) { | |
1da177e4 | 1487 | netlink_overrun(sk); |
cc3a572f | 1488 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1489 | p->delivery_failure = 1; |
1da177e4 LT |
1490 | } else { |
1491 | p->congested |= val; | |
1492 | p->delivered = 1; | |
1493 | p->skb2 = NULL; | |
1494 | } | |
59324cf3 | 1495 | out: |
1da177e4 | 1496 | sock_put(sk); |
1da177e4 LT |
1497 | } |
1498 | ||
15e47304 | 1499 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1500 | u32 group, gfp_t allocation, |
1501 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1502 | void *filter_data) | |
1da177e4 | 1503 | { |
3b1e0a65 | 1504 | struct net *net = sock_net(ssk); |
1da177e4 | 1505 | struct netlink_broadcast_data info; |
1da177e4 LT |
1506 | struct sock *sk; |
1507 | ||
1508 | skb = netlink_trim(skb, allocation); | |
1509 | ||
1510 | info.exclude_sk = ssk; | |
b4b51029 | 1511 | info.net = net; |
15e47304 | 1512 | info.portid = portid; |
1da177e4 LT |
1513 | info.group = group; |
1514 | info.failure = 0; | |
ff491a73 | 1515 | info.delivery_failure = 0; |
1da177e4 LT |
1516 | info.congested = 0; |
1517 | info.delivered = 0; | |
1518 | info.allocation = allocation; | |
1519 | info.skb = skb; | |
1520 | info.skb2 = NULL; | |
910a7e90 EB |
1521 | info.tx_filter = filter; |
1522 | info.tx_data = filter_data; | |
1da177e4 LT |
1523 | |
1524 | /* While we sleep in clone, do not allow to change socket list */ | |
1525 | ||
1526 | netlink_lock_table(); | |
1527 | ||
b67bfe0d | 1528 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1529 | do_one_broadcast(sk, &info); |
1530 | ||
70d4bf6d | 1531 | consume_skb(skb); |
aa1c6a6f | 1532 | |
1da177e4 LT |
1533 | netlink_unlock_table(); |
1534 | ||
70d4bf6d NH |
1535 | if (info.delivery_failure) { |
1536 | kfree_skb(info.skb2); | |
ff491a73 | 1537 | return -ENOBUFS; |
658cb354 ED |
1538 | } |
1539 | consume_skb(info.skb2); | |
ff491a73 | 1540 | |
1da177e4 | 1541 | if (info.delivered) { |
d0164adc | 1542 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1543 | yield(); |
1544 | return 0; | |
1545 | } | |
1da177e4 LT |
1546 | return -ESRCH; |
1547 | } | |
910a7e90 EB |
1548 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1549 | ||
15e47304 | 1550 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1551 | u32 group, gfp_t allocation) |
1552 | { | |
15e47304 | 1553 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1554 | NULL, NULL); |
1555 | } | |
6ac552fd | 1556 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1557 | |
1558 | struct netlink_set_err_data { | |
1559 | struct sock *exclude_sk; | |
15e47304 | 1560 | u32 portid; |
1da177e4 LT |
1561 | u32 group; |
1562 | int code; | |
1563 | }; | |
1564 | ||
b57ef81f | 1565 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1566 | { |
1567 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1568 | int ret = 0; |
1da177e4 LT |
1569 | |
1570 | if (sk == p->exclude_sk) | |
1571 | goto out; | |
1572 | ||
09ad9bc7 | 1573 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1574 | goto out; |
1575 | ||
15e47304 | 1576 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1577 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1578 | goto out; |
1579 | ||
cc3a572f | 1580 | if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
1a50307b PNA |
1581 | ret = 1; |
1582 | goto out; | |
1583 | } | |
1584 | ||
1da177e4 | 1585 | sk->sk_err = p->code; |
e3ae2365 | 1586 | sk_error_report(sk); |
1da177e4 | 1587 | out: |
1a50307b | 1588 | return ret; |
1da177e4 LT |
1589 | } |
1590 | ||
4843b93c PNA |
1591 | /** |
1592 | * netlink_set_err - report error to broadcast listeners | |
1593 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1594 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1595 | * @group: the broadcast group that will notice the error |
4843b93c | 1596 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1597 | * |
1598 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1599 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1600 | */ |
15e47304 | 1601 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1602 | { |
1603 | struct netlink_set_err_data info; | |
1da177e4 | 1604 | struct sock *sk; |
1a50307b | 1605 | int ret = 0; |
1da177e4 LT |
1606 | |
1607 | info.exclude_sk = ssk; | |
15e47304 | 1608 | info.portid = portid; |
1da177e4 | 1609 | info.group = group; |
4843b93c PNA |
1610 | /* sk->sk_err wants a positive error value */ |
1611 | info.code = -code; | |
1da177e4 LT |
1612 | |
1613 | read_lock(&nl_table_lock); | |
1614 | ||
b67bfe0d | 1615 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1616 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1617 | |
1618 | read_unlock(&nl_table_lock); | |
1a50307b | 1619 | return ret; |
1da177e4 | 1620 | } |
dd5b6ce6 | 1621 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1622 | |
84659eb5 JB |
1623 | /* must be called with netlink table grabbed */ |
1624 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1625 | unsigned int group, | |
1626 | int is_new) | |
1627 | { | |
1628 | int old, new = !!is_new, subscriptions; | |
1629 | ||
1630 | old = test_bit(group - 1, nlk->groups); | |
1631 | subscriptions = nlk->subscriptions - old + new; | |
1632 | if (new) | |
1633 | __set_bit(group - 1, nlk->groups); | |
1634 | else | |
1635 | __clear_bit(group - 1, nlk->groups); | |
1636 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1637 | netlink_update_listeners(&nlk->sk); | |
1638 | } | |
1639 | ||
9a4595bc | 1640 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
a7b75c5a | 1641 | sockptr_t optval, unsigned int optlen) |
9a4595bc PM |
1642 | { |
1643 | struct sock *sk = sock->sk; | |
1644 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1645 | unsigned int val = 0; |
1646 | int err; | |
9a4595bc PM |
1647 | |
1648 | if (level != SOL_NETLINK) | |
1649 | return -ENOPROTOOPT; | |
1650 | ||
d1b4c689 | 1651 | if (optlen >= sizeof(int) && |
a7b75c5a | 1652 | copy_from_sockptr(&val, optval, sizeof(val))) |
9a4595bc PM |
1653 | return -EFAULT; |
1654 | ||
1655 | switch (optname) { | |
1656 | case NETLINK_PKTINFO: | |
1657 | if (val) | |
cc3a572f | 1658 | nlk->flags |= NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1659 | else |
cc3a572f | 1660 | nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1661 | err = 0; |
1662 | break; | |
1663 | case NETLINK_ADD_MEMBERSHIP: | |
1664 | case NETLINK_DROP_MEMBERSHIP: { | |
5187cd05 | 1665 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1666 | return -EPERM; |
b4ff4f04 JB |
1667 | err = netlink_realloc_groups(sk); |
1668 | if (err) | |
1669 | return err; | |
9a4595bc PM |
1670 | if (!val || val - 1 >= nlk->ngroups) |
1671 | return -EINVAL; | |
7774d5e0 | 1672 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1673 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1674 | if (err) |
1675 | return err; | |
1676 | } | |
9a4595bc | 1677 | netlink_table_grab(); |
84659eb5 JB |
1678 | netlink_update_socket_mc(nlk, val, |
1679 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1680 | netlink_table_ungrab(); |
7774d5e0 | 1681 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1682 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1683 | |
9a4595bc PM |
1684 | err = 0; |
1685 | break; | |
1686 | } | |
be0c22a4 PNA |
1687 | case NETLINK_BROADCAST_ERROR: |
1688 | if (val) | |
cc3a572f | 1689 | nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1690 | else |
cc3a572f | 1691 | nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 PNA |
1692 | err = 0; |
1693 | break; | |
38938bfe PNA |
1694 | case NETLINK_NO_ENOBUFS: |
1695 | if (val) { | |
cc3a572f ND |
1696 | nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
1697 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); | |
38938bfe | 1698 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1699 | } else { |
cc3a572f | 1700 | nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
658cb354 | 1701 | } |
38938bfe PNA |
1702 | err = 0; |
1703 | break; | |
59324cf3 ND |
1704 | case NETLINK_LISTEN_ALL_NSID: |
1705 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1706 | return -EPERM; | |
1707 | ||
1708 | if (val) | |
1709 | nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; | |
1710 | else | |
1711 | nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; | |
1712 | err = 0; | |
1713 | break; | |
0a6a3a23 CR |
1714 | case NETLINK_CAP_ACK: |
1715 | if (val) | |
1716 | nlk->flags |= NETLINK_F_CAP_ACK; | |
1717 | else | |
1718 | nlk->flags &= ~NETLINK_F_CAP_ACK; | |
1719 | err = 0; | |
1720 | break; | |
2d4bc933 JB |
1721 | case NETLINK_EXT_ACK: |
1722 | if (val) | |
1723 | nlk->flags |= NETLINK_F_EXT_ACK; | |
1724 | else | |
1725 | nlk->flags &= ~NETLINK_F_EXT_ACK; | |
1726 | err = 0; | |
1727 | break; | |
d3e8869e | 1728 | case NETLINK_GET_STRICT_CHK: |
89d35528 DA |
1729 | if (val) |
1730 | nlk->flags |= NETLINK_F_STRICT_CHK; | |
1731 | else | |
1732 | nlk->flags &= ~NETLINK_F_STRICT_CHK; | |
1733 | err = 0; | |
1734 | break; | |
9a4595bc PM |
1735 | default: |
1736 | err = -ENOPROTOOPT; | |
1737 | } | |
1738 | return err; | |
1739 | } | |
1740 | ||
1741 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1742 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1743 | { |
1744 | struct sock *sk = sock->sk; | |
1745 | struct netlink_sock *nlk = nlk_sk(sk); | |
1746 | int len, val, err; | |
1747 | ||
1748 | if (level != SOL_NETLINK) | |
1749 | return -ENOPROTOOPT; | |
1750 | ||
1751 | if (get_user(len, optlen)) | |
1752 | return -EFAULT; | |
1753 | if (len < 0) | |
1754 | return -EINVAL; | |
1755 | ||
1756 | switch (optname) { | |
1757 | case NETLINK_PKTINFO: | |
1758 | if (len < sizeof(int)) | |
1759 | return -EINVAL; | |
1760 | len = sizeof(int); | |
cc3a572f | 1761 | val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
a27b58fe HC |
1762 | if (put_user(len, optlen) || |
1763 | put_user(val, optval)) | |
1764 | return -EFAULT; | |
9a4595bc PM |
1765 | err = 0; |
1766 | break; | |
be0c22a4 PNA |
1767 | case NETLINK_BROADCAST_ERROR: |
1768 | if (len < sizeof(int)) | |
1769 | return -EINVAL; | |
1770 | len = sizeof(int); | |
cc3a572f | 1771 | val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
be0c22a4 PNA |
1772 | if (put_user(len, optlen) || |
1773 | put_user(val, optval)) | |
1774 | return -EFAULT; | |
1775 | err = 0; | |
1776 | break; | |
38938bfe PNA |
1777 | case NETLINK_NO_ENOBUFS: |
1778 | if (len < sizeof(int)) | |
1779 | return -EINVAL; | |
1780 | len = sizeof(int); | |
cc3a572f | 1781 | val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
38938bfe PNA |
1782 | if (put_user(len, optlen) || |
1783 | put_user(val, optval)) | |
1784 | return -EFAULT; | |
1785 | err = 0; | |
1786 | break; | |
b42be38b DH |
1787 | case NETLINK_LIST_MEMBERSHIPS: { |
1788 | int pos, idx, shift; | |
1789 | ||
1790 | err = 0; | |
47191d65 | 1791 | netlink_lock_table(); |
b42be38b DH |
1792 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1793 | if (len - pos < sizeof(u32)) | |
1794 | break; | |
1795 | ||
1796 | idx = pos / sizeof(unsigned long); | |
1797 | shift = (pos % sizeof(unsigned long)) * 8; | |
1798 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1799 | (u32 __user *)(optval + pos))) { | |
1800 | err = -EFAULT; | |
1801 | break; | |
1802 | } | |
1803 | } | |
1804 | if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) | |
1805 | err = -EFAULT; | |
47191d65 | 1806 | netlink_unlock_table(); |
b42be38b DH |
1807 | break; |
1808 | } | |
0a6a3a23 CR |
1809 | case NETLINK_CAP_ACK: |
1810 | if (len < sizeof(int)) | |
1811 | return -EINVAL; | |
1812 | len = sizeof(int); | |
1813 | val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; | |
1814 | if (put_user(len, optlen) || | |
1815 | put_user(val, optval)) | |
1816 | return -EFAULT; | |
1817 | err = 0; | |
1818 | break; | |
2d4bc933 JB |
1819 | case NETLINK_EXT_ACK: |
1820 | if (len < sizeof(int)) | |
1821 | return -EINVAL; | |
1822 | len = sizeof(int); | |
1823 | val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0; | |
1824 | if (put_user(len, optlen) || put_user(val, optval)) | |
1825 | return -EFAULT; | |
1826 | err = 0; | |
1827 | break; | |
d3e8869e | 1828 | case NETLINK_GET_STRICT_CHK: |
89d35528 DA |
1829 | if (len < sizeof(int)) |
1830 | return -EINVAL; | |
1831 | len = sizeof(int); | |
1832 | val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0; | |
1833 | if (put_user(len, optlen) || put_user(val, optval)) | |
1834 | return -EFAULT; | |
1835 | err = 0; | |
1836 | break; | |
9a4595bc PM |
1837 | default: |
1838 | err = -ENOPROTOOPT; | |
1839 | } | |
1840 | return err; | |
1841 | } | |
1842 | ||
1843 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1844 | { | |
1845 | struct nl_pktinfo info; | |
1846 | ||
1847 | info.group = NETLINK_CB(skb).dst_group; | |
1848 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1849 | } | |
1850 | ||
59324cf3 ND |
1851 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1852 | struct sk_buff *skb) | |
1853 | { | |
1854 | if (!NETLINK_CB(skb).nsid_is_set) | |
1855 | return; | |
1856 | ||
1857 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1858 | &NETLINK_CB(skb).nsid); | |
1859 | } | |
1860 | ||
1b784140 | 1861 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1862 | { |
1da177e4 LT |
1863 | struct sock *sk = sock->sk; |
1864 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1865 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1866 | u32 dst_portid; |
d629b836 | 1867 | u32 dst_group; |
1da177e4 LT |
1868 | struct sk_buff *skb; |
1869 | int err; | |
1870 | struct scm_cookie scm; | |
2d7a85f4 | 1871 | u32 netlink_skb_flags = 0; |
1da177e4 | 1872 | |
4d11af5d | 1873 | if (msg->msg_flags & MSG_OOB) |
1da177e4 LT |
1874 | return -EOPNOTSUPP; |
1875 | ||
fbac7719 HM |
1876 | if (len == 0) { |
1877 | pr_warn_once("Zero length message leads to an empty skb\n"); | |
1878 | return -ENODATA; | |
1879 | } | |
1880 | ||
7cc05662 | 1881 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1882 | if (err < 0) |
1883 | return err; | |
1884 | ||
1885 | if (msg->msg_namelen) { | |
b47030c7 | 1886 | err = -EINVAL; |
6091f09c ED |
1887 | if (msg->msg_namelen < sizeof(struct sockaddr_nl)) |
1888 | goto out; | |
1da177e4 | 1889 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1890 | goto out; |
15e47304 | 1891 | dst_portid = addr->nl_pid; |
d629b836 | 1892 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1893 | err = -EPERM; |
15e47304 | 1894 | if ((dst_group || dst_portid) && |
5187cd05 | 1895 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1896 | goto out; |
2d7a85f4 | 1897 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1898 | } else { |
15e47304 | 1899 | dst_portid = nlk->dst_portid; |
d629b836 | 1900 | dst_group = nlk->dst_group; |
1da177e4 LT |
1901 | } |
1902 | ||
7707a4d0 ED |
1903 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1904 | if (!READ_ONCE(nlk->bound)) { | |
1da177e4 LT |
1905 | err = netlink_autobind(sock); |
1906 | if (err) | |
1907 | goto out; | |
da314c99 HX |
1908 | } else { |
1909 | /* Ensure nlk is hashed and visible. */ | |
1910 | smp_rmb(); | |
1da177e4 LT |
1911 | } |
1912 | ||
1913 | err = -EMSGSIZE; | |
1914 | if (len > sk->sk_sndbuf - 32) | |
1915 | goto out; | |
1916 | err = -ENOBUFS; | |
3a36515f | 1917 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1918 | if (skb == NULL) |
1da177e4 LT |
1919 | goto out; |
1920 | ||
15e47304 | 1921 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1922 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1923 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1924 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1925 | |
1da177e4 | 1926 | err = -EFAULT; |
6ce8e9ce | 1927 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1928 | kfree_skb(skb); |
1929 | goto out; | |
1930 | } | |
1931 | ||
1932 | err = security_netlink_send(sk, skb); | |
1933 | if (err) { | |
1934 | kfree_skb(skb); | |
1935 | goto out; | |
1936 | } | |
1937 | ||
d629b836 | 1938 | if (dst_group) { |
63354797 | 1939 | refcount_inc(&skb->users); |
15e47304 | 1940 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1941 | } |
4d11af5d | 1942 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT); |
1da177e4 LT |
1943 | |
1944 | out: | |
7cc05662 | 1945 | scm_destroy(&scm); |
1da177e4 LT |
1946 | return err; |
1947 | } | |
1948 | ||
1b784140 | 1949 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1950 | int flags) |
1951 | { | |
1da177e4 LT |
1952 | struct scm_cookie scm; |
1953 | struct sock *sk = sock->sk; | |
1954 | struct netlink_sock *nlk = nlk_sk(sk); | |
4d11af5d | 1955 | int noblock = flags & MSG_DONTWAIT; |
1da177e4 | 1956 | size_t copied; |
68d6ac6d | 1957 | struct sk_buff *skb, *data_skb; |
b44d211e | 1958 | int err, ret; |
1da177e4 | 1959 | |
4d11af5d | 1960 | if (flags & MSG_OOB) |
1da177e4 LT |
1961 | return -EOPNOTSUPP; |
1962 | ||
1963 | copied = 0; | |
1964 | ||
6ac552fd PM |
1965 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1966 | if (skb == NULL) | |
1da177e4 LT |
1967 | goto out; |
1968 | ||
68d6ac6d JB |
1969 | data_skb = skb; |
1970 | ||
1dacc76d JB |
1971 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1972 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1973 | /* |
68d6ac6d JB |
1974 | * If this skb has a frag_list, then here that means that we |
1975 | * will have to use the frag_list skb's data for compat tasks | |
1976 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1977 | * |
68d6ac6d JB |
1978 | * If we need to send the compat skb, assign it to the |
1979 | * 'data_skb' variable so that it will be used below for data | |
1980 | * copying. We keep 'skb' for everything else, including | |
1981 | * freeing both later. | |
1dacc76d | 1982 | */ |
68d6ac6d JB |
1983 | if (flags & MSG_CMSG_COMPAT) |
1984 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1985 | } |
1986 | #endif | |
1987 | ||
9063e21f ED |
1988 | /* Record the max length of recvmsg() calls for future allocations */ |
1989 | nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); | |
1990 | nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, | |
d35c99ff | 1991 | SKB_WITH_OVERHEAD(32768)); |
9063e21f | 1992 | |
68d6ac6d | 1993 | copied = data_skb->len; |
1da177e4 LT |
1994 | if (len < copied) { |
1995 | msg->msg_flags |= MSG_TRUNC; | |
1996 | copied = len; | |
1997 | } | |
1998 | ||
68d6ac6d | 1999 | skb_reset_transport_header(data_skb); |
51f3d02b | 2000 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
2001 | |
2002 | if (msg->msg_name) { | |
342dfc30 | 2003 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
2004 | addr->nl_family = AF_NETLINK; |
2005 | addr->nl_pad = 0; | |
15e47304 | 2006 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 2007 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
2008 | msg->msg_namelen = sizeof(*addr); |
2009 | } | |
2010 | ||
cc3a572f | 2011 | if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
cc9a06cd | 2012 | netlink_cmsg_recv_pktinfo(msg, skb); |
59324cf3 ND |
2013 | if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
2014 | netlink_cmsg_listen_all_nsid(sk, msg, skb); | |
cc9a06cd | 2015 | |
7cc05662 CH |
2016 | memset(&scm, 0, sizeof(scm)); |
2017 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 2018 | if (flags & MSG_TRUNC) |
68d6ac6d | 2019 | copied = data_skb->len; |
daa3766e | 2020 | |
1da177e4 LT |
2021 | skb_free_datagram(sk, skb); |
2022 | ||
16b304f3 PS |
2023 | if (nlk->cb_running && |
2024 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
2025 | ret = netlink_dump(sk); |
2026 | if (ret) { | |
ac30ef83 | 2027 | sk->sk_err = -ret; |
e3ae2365 | 2028 | sk_error_report(sk); |
b44d211e AV |
2029 | } |
2030 | } | |
1da177e4 | 2031 | |
7cc05662 | 2032 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
2033 | out: |
2034 | netlink_rcv_wake(sk); | |
2035 | return err ? : copied; | |
2036 | } | |
2037 | ||
676d2369 | 2038 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 2039 | { |
cd40b7d3 | 2040 | BUG(); |
1da177e4 LT |
2041 | } |
2042 | ||
2043 | /* | |
746fac4d | 2044 | * We export these functions to other modules. They provide a |
1da177e4 LT |
2045 | * complete set of kernel non-blocking support for message |
2046 | * queueing. | |
2047 | */ | |
2048 | ||
2049 | struct sock * | |
9f00d977 PNA |
2050 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
2051 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
2052 | { |
2053 | struct socket *sock; | |
2054 | struct sock *sk; | |
77247bbb | 2055 | struct netlink_sock *nlk; |
5c398dc8 | 2056 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
2057 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
2058 | unsigned int groups; | |
1da177e4 | 2059 | |
fab2caf6 | 2060 | BUG_ON(!nl_table); |
1da177e4 | 2061 | |
6ac552fd | 2062 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
2063 | return NULL; |
2064 | ||
2065 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
2066 | return NULL; | |
13d3078e EB |
2067 | |
2068 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
2069 | goto out_sock_release_nosk; |
2070 | ||
2071 | sk = sock->sk; | |
4fdb3bb7 | 2072 | |
a31f2d17 | 2073 | if (!cfg || cfg->groups < 32) |
4277a083 | 2074 | groups = 32; |
a31f2d17 PNA |
2075 | else |
2076 | groups = cfg->groups; | |
4277a083 | 2077 | |
5c398dc8 | 2078 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
2079 | if (!listeners) |
2080 | goto out_sock_release; | |
2081 | ||
1da177e4 | 2082 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
2083 | if (cfg && cfg->input) |
2084 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 2085 | |
8ea65f4a | 2086 | if (netlink_insert(sk, 0)) |
77247bbb | 2087 | goto out_sock_release; |
4fdb3bb7 | 2088 | |
77247bbb | 2089 | nlk = nlk_sk(sk); |
cc3a572f | 2090 | nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
4fdb3bb7 | 2091 | |
4fdb3bb7 | 2092 | netlink_table_grab(); |
b4b51029 EB |
2093 | if (!nl_table[unit].registered) { |
2094 | nl_table[unit].groups = groups; | |
5c398dc8 | 2095 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
2096 | nl_table[unit].cb_mutex = cb_mutex; |
2097 | nl_table[unit].module = module; | |
9785e10a PNA |
2098 | if (cfg) { |
2099 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 2100 | nl_table[unit].unbind = cfg->unbind; |
9785e10a | 2101 | nl_table[unit].flags = cfg->flags; |
da12c90e G |
2102 | if (cfg->compare) |
2103 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 2104 | } |
b4b51029 | 2105 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
2106 | } else { |
2107 | kfree(listeners); | |
869e58f8 | 2108 | nl_table[unit].registered++; |
b4b51029 | 2109 | } |
4fdb3bb7 | 2110 | netlink_table_ungrab(); |
77247bbb PM |
2111 | return sk; |
2112 | ||
4fdb3bb7 | 2113 | out_sock_release: |
4277a083 | 2114 | kfree(listeners); |
9dfbec1f | 2115 | netlink_kernel_release(sk); |
23fe1866 PE |
2116 | return NULL; |
2117 | ||
2118 | out_sock_release_nosk: | |
4fdb3bb7 | 2119 | sock_release(sock); |
77247bbb | 2120 | return NULL; |
1da177e4 | 2121 | } |
9f00d977 | 2122 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
2123 | |
2124 | void | |
2125 | netlink_kernel_release(struct sock *sk) | |
2126 | { | |
13d3078e EB |
2127 | if (sk == NULL || sk->sk_socket == NULL) |
2128 | return; | |
2129 | ||
2130 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
2131 | } |
2132 | EXPORT_SYMBOL(netlink_kernel_release); | |
2133 | ||
d136f1bd | 2134 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 2135 | { |
5c398dc8 | 2136 | struct listeners *new, *old; |
b4ff4f04 | 2137 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2138 | |
2139 | if (groups < 32) | |
2140 | groups = 32; | |
2141 | ||
b4ff4f04 | 2142 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2143 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2144 | if (!new) | |
d136f1bd | 2145 | return -ENOMEM; |
6d772ac5 | 2146 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2147 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2148 | rcu_assign_pointer(tbl->listeners, new); | |
2149 | ||
37b6b935 | 2150 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2151 | } |
2152 | tbl->groups = groups; | |
2153 | ||
d136f1bd JB |
2154 | return 0; |
2155 | } | |
2156 | ||
2157 | /** | |
2158 | * netlink_change_ngroups - change number of multicast groups | |
2159 | * | |
2160 | * This changes the number of multicast groups that are available | |
2161 | * on a certain netlink family. Note that it is not possible to | |
2162 | * change the number of groups to below 32. Also note that it does | |
2163 | * not implicitly call netlink_clear_multicast_users() when the | |
2164 | * number of groups is reduced. | |
2165 | * | |
2166 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2167 | * @groups: The new number of groups. | |
2168 | */ | |
2169 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2170 | { | |
2171 | int err; | |
2172 | ||
2173 | netlink_table_grab(); | |
2174 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2175 | netlink_table_ungrab(); |
d136f1bd | 2176 | |
b4ff4f04 JB |
2177 | return err; |
2178 | } | |
b4ff4f04 | 2179 | |
b8273570 JB |
2180 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2181 | { | |
2182 | struct sock *sk; | |
b8273570 JB |
2183 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2184 | ||
b67bfe0d | 2185 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2186 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2187 | } | |
2188 | ||
a46621a3 | 2189 | struct nlmsghdr * |
15e47304 | 2190 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2191 | { |
2192 | struct nlmsghdr *nlh; | |
573ce260 | 2193 | int size = nlmsg_msg_size(len); |
a46621a3 | 2194 | |
4df864c1 | 2195 | nlh = skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2196 | nlh->nlmsg_type = type; |
2197 | nlh->nlmsg_len = size; | |
2198 | nlh->nlmsg_flags = flags; | |
15e47304 | 2199 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2200 | nlh->nlmsg_seq = seq; |
2201 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2202 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2203 | return nlh; |
2204 | } | |
2205 | EXPORT_SYMBOL(__nlmsg_put); | |
2206 | ||
1da177e4 LT |
2207 | /* |
2208 | * It looks a bit ugly. | |
2209 | * It would be better to create kernel thread. | |
2210 | */ | |
2211 | ||
e11eb32d DS |
2212 | static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb, |
2213 | struct netlink_callback *cb, | |
2214 | struct netlink_ext_ack *extack) | |
2215 | { | |
2216 | struct nlmsghdr *nlh; | |
2217 | ||
2218 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno), | |
2219 | NLM_F_MULTI | cb->answer_flags); | |
2220 | if (WARN_ON(!nlh)) | |
2221 | return -ENOBUFS; | |
2222 | ||
2223 | nl_dump_check_consistent(cb, nlh); | |
2224 | memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); | |
2225 | ||
2226 | if (extack->_msg && nlk->flags & NETLINK_F_EXT_ACK) { | |
2227 | nlh->nlmsg_flags |= NLM_F_ACK_TLVS; | |
2228 | if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)) | |
2229 | nlmsg_end(skb, nlh); | |
2230 | } | |
2231 | ||
2232 | return 0; | |
2233 | } | |
2234 | ||
1da177e4 LT |
2235 | static int netlink_dump(struct sock *sk) |
2236 | { | |
2237 | struct netlink_sock *nlk = nlk_sk(sk); | |
4a19edb6 | 2238 | struct netlink_ext_ack extack = {}; |
1da177e4 | 2239 | struct netlink_callback *cb; |
c7ac8679 | 2240 | struct sk_buff *skb = NULL; |
92964c79 | 2241 | struct module *module; |
0642840b | 2242 | int err = -ENOBUFS; |
db65a3aa | 2243 | int alloc_min_size; |
c7ac8679 | 2244 | int alloc_size; |
1da177e4 | 2245 | |
af65bdfc | 2246 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2247 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2248 | err = -EINVAL; |
2249 | goto errout_skb; | |
1da177e4 LT |
2250 | } |
2251 | ||
d1b4c689 | 2252 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2253 | goto errout_skb; |
9063e21f ED |
2254 | |
2255 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2256 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2257 | * to reduce number of system calls on dump operations, if user | |
2258 | * ever provided a big enough buffer. | |
2259 | */ | |
db65a3aa AR |
2260 | cb = &nlk->cb; |
2261 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2262 | ||
2263 | if (alloc_min_size < nlk->max_recvmsg_len) { | |
2264 | alloc_size = nlk->max_recvmsg_len; | |
d35c99ff ED |
2265 | skb = alloc_skb(alloc_size, |
2266 | (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | | |
2267 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2268 | } |
db65a3aa AR |
2269 | if (!skb) { |
2270 | alloc_size = alloc_min_size; | |
c5b0db32 | 2271 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2272 | } |
c7ac8679 | 2273 | if (!skb) |
c63d6ea3 | 2274 | goto errout_skb; |
db65a3aa AR |
2275 | |
2276 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2277 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2278 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2279 | * could fit within the allocated skb. skb is typically allocated | |
2280 | * with larger space than required (could be as much as near 2x the | |
2281 | * requested size with align to next power of 2 approach). Allowing | |
2282 | * dump to use the excess space makes it difficult for a user to have a | |
2283 | * reasonable static buffer based on the expected largest dump of a | |
2284 | * single netdev. The outcome is MSG_TRUNC error. | |
2285 | */ | |
d1b4c689 | 2286 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
f9c22888 | 2287 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2288 | |
4a19edb6 DA |
2289 | if (nlk->dump_done_errno > 0) { |
2290 | cb->extack = &extack; | |
0642840b | 2291 | nlk->dump_done_errno = cb->dump(skb, cb); |
4a19edb6 DA |
2292 | cb->extack = NULL; |
2293 | } | |
1da177e4 | 2294 | |
0642840b JD |
2295 | if (nlk->dump_done_errno > 0 || |
2296 | skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { | |
af65bdfc | 2297 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2298 | |
2299 | if (sk_filter(sk, skb)) | |
2300 | kfree_skb(skb); | |
4a7e7c2a ED |
2301 | else |
2302 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2303 | return 0; |
2304 | } | |
2305 | ||
e11eb32d | 2306 | if (netlink_dump_done(nlk, skb, cb, &extack)) |
bf8b79e4 TG |
2307 | goto errout_skb; |
2308 | ||
e11eb32d DS |
2309 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
2310 | /* frag_list skb's data is used for compat tasks | |
2311 | * and the regular skb's data for normal (non-compat) tasks. | |
2312 | * See netlink_recvmsg(). | |
2313 | */ | |
2314 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
2315 | if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack)) | |
2316 | goto errout_skb; | |
4a19edb6 | 2317 | } |
e11eb32d | 2318 | #endif |
4a19edb6 | 2319 | |
b1153f29 SH |
2320 | if (sk_filter(sk, skb)) |
2321 | kfree_skb(skb); | |
4a7e7c2a ED |
2322 | else |
2323 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2324 | |
a8f74b22 TG |
2325 | if (cb->done) |
2326 | cb->done(cb); | |
1da177e4 | 2327 | |
16b304f3 | 2328 | nlk->cb_running = false; |
92964c79 HX |
2329 | module = cb->module; |
2330 | skb = cb->skb; | |
16b304f3 | 2331 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2332 | module_put(module); |
2333 | consume_skb(skb); | |
1da177e4 | 2334 | return 0; |
1797754e | 2335 | |
bf8b79e4 | 2336 | errout_skb: |
af65bdfc | 2337 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2338 | kfree_skb(skb); |
bf8b79e4 | 2339 | return err; |
1da177e4 LT |
2340 | } |
2341 | ||
6dc878a8 G |
2342 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2343 | const struct nlmsghdr *nlh, | |
2344 | struct netlink_dump_control *control) | |
1da177e4 | 2345 | { |
89d35528 | 2346 | struct netlink_sock *nlk, *nlk2; |
1da177e4 LT |
2347 | struct netlink_callback *cb; |
2348 | struct sock *sk; | |
b44d211e | 2349 | int ret; |
1da177e4 | 2350 | |
63354797 | 2351 | refcount_inc(&skb->users); |
f9c22888 | 2352 | |
15e47304 | 2353 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2354 | if (sk == NULL) { |
16b304f3 PS |
2355 | ret = -ECONNREFUSED; |
2356 | goto error_free; | |
1da177e4 | 2357 | } |
6dc878a8 | 2358 | |
16b304f3 | 2359 | nlk = nlk_sk(sk); |
af65bdfc | 2360 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2361 | /* A dump is in progress... */ |
16b304f3 | 2362 | if (nlk->cb_running) { |
6dc878a8 | 2363 | ret = -EBUSY; |
16b304f3 | 2364 | goto error_unlock; |
1da177e4 | 2365 | } |
6dc878a8 | 2366 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2367 | if (!try_module_get(control->module)) { |
6dc878a8 | 2368 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2369 | goto error_unlock; |
6dc878a8 G |
2370 | } |
2371 | ||
16b304f3 PS |
2372 | cb = &nlk->cb; |
2373 | memset(cb, 0, sizeof(*cb)); | |
2374 | cb->dump = control->dump; | |
2375 | cb->done = control->done; | |
2376 | cb->nlh = nlh; | |
2377 | cb->data = control->data; | |
2378 | cb->module = control->module; | |
2379 | cb->min_dump_alloc = control->min_dump_alloc; | |
2380 | cb->skb = skb; | |
2381 | ||
89d35528 DA |
2382 | nlk2 = nlk_sk(NETLINK_CB(skb).sk); |
2383 | cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK); | |
2384 | ||
3730cf4d FW |
2385 | if (control->start) { |
2386 | ret = control->start(cb); | |
41c87425 | 2387 | if (ret) |
b87b6194 | 2388 | goto error_put; |
41c87425 JD |
2389 | } |
2390 | ||
16b304f3 | 2391 | nlk->cb_running = true; |
0642840b | 2392 | nlk->dump_done_errno = INT_MAX; |
16b304f3 | 2393 | |
af65bdfc | 2394 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2395 | |
41c87425 | 2396 | ret = netlink_dump(sk); |
fc9e50f5 | 2397 | |
1da177e4 | 2398 | sock_put(sk); |
5c58298c | 2399 | |
b44d211e AV |
2400 | if (ret) |
2401 | return ret; | |
2402 | ||
5c58298c DL |
2403 | /* We successfully started a dump, by returning -EINTR we |
2404 | * signal not to send ACK even if it was requested. | |
2405 | */ | |
2406 | return -EINTR; | |
16b304f3 | 2407 | |
b87b6194 JD |
2408 | error_put: |
2409 | module_put(control->module); | |
16b304f3 PS |
2410 | error_unlock: |
2411 | sock_put(sk); | |
2412 | mutex_unlock(nlk->cb_mutex); | |
2413 | error_free: | |
2414 | kfree_skb(skb); | |
2415 | return ret; | |
1da177e4 | 2416 | } |
6dc878a8 | 2417 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 | 2418 | |
2d4bc933 JB |
2419 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
2420 | const struct netlink_ext_ack *extack) | |
1da177e4 LT |
2421 | { |
2422 | struct sk_buff *skb; | |
2423 | struct nlmsghdr *rep; | |
2424 | struct nlmsgerr *errmsg; | |
339bf98f | 2425 | size_t payload = sizeof(*errmsg); |
2d4bc933 | 2426 | size_t tlvlen = 0; |
0a6a3a23 | 2427 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
2d4bc933 | 2428 | unsigned int flags = 0; |
48044eb4 | 2429 | bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK; |
1da177e4 | 2430 | |
0a6a3a23 | 2431 | /* Error messages get the original request appened, unless the user |
2d4bc933 JB |
2432 | * requests to cap the error message, and get extra error data if |
2433 | * requested. | |
0a6a3a23 | 2434 | */ |
4f6265d4 DA |
2435 | if (nlk_has_extack && extack && extack->_msg) |
2436 | tlvlen += nla_total_size(strlen(extack->_msg) + 1); | |
2437 | ||
fe2a31d7 MK |
2438 | if (err && !(nlk->flags & NETLINK_F_CAP_ACK)) |
2439 | payload += nlmsg_len(nlh); | |
2440 | else | |
2d4bc933 | 2441 | flags |= NLM_F_CAPPED; |
fe2a31d7 MK |
2442 | if (err && nlk_has_extack && extack && extack->bad_attr) |
2443 | tlvlen += nla_total_size(sizeof(u32)); | |
2444 | if (nlk_has_extack && extack && extack->cookie_len) | |
2445 | tlvlen += nla_total_size(extack->cookie_len); | |
44f3625b JB |
2446 | if (err && nlk_has_extack && extack && extack->policy) |
2447 | tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); | |
1da177e4 | 2448 | |
2d4bc933 JB |
2449 | if (tlvlen) |
2450 | flags |= NLM_F_ACK_TLVS; | |
2451 | ||
2452 | skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); | |
1da177e4 | 2453 | if (!skb) { |
a2084f56 | 2454 | NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; |
e3ae2365 | 2455 | sk_error_report(NETLINK_CB(in_skb).sk); |
1da177e4 LT |
2456 | return; |
2457 | } | |
2458 | ||
15e47304 | 2459 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
2d4bc933 | 2460 | NLMSG_ERROR, payload, flags); |
bf8b79e4 | 2461 | errmsg = nlmsg_data(rep); |
1da177e4 | 2462 | errmsg->error = err; |
0a6a3a23 | 2463 | memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
2d4bc933 | 2464 | |
48044eb4 | 2465 | if (nlk_has_extack && extack) { |
4f6265d4 DA |
2466 | if (extack->_msg) { |
2467 | WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, | |
2468 | extack->_msg)); | |
2469 | } | |
fe2a31d7 MK |
2470 | if (err && extack->bad_attr && |
2471 | !WARN_ON((u8 *)extack->bad_attr < in_skb->data || | |
2472 | (u8 *)extack->bad_attr >= in_skb->data + | |
2473 | in_skb->len)) | |
2474 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, | |
2475 | (u8 *)extack->bad_attr - | |
2476 | (u8 *)nlh)); | |
2477 | if (extack->cookie_len) | |
2478 | WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, | |
2479 | extack->cookie_len, extack->cookie)); | |
44f3625b JB |
2480 | if (extack->policy) |
2481 | netlink_policy_dump_write_attr(skb, extack->policy, | |
2482 | NLMSGERR_ATTR_POLICY); | |
2d4bc933 JB |
2483 | } |
2484 | ||
2485 | nlmsg_end(skb, rep); | |
2486 | ||
01757f53 | 2487 | nlmsg_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid); |
1da177e4 | 2488 | } |
6ac552fd | 2489 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2490 | |
cd40b7d3 | 2491 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
2d4bc933 JB |
2492 | struct nlmsghdr *, |
2493 | struct netlink_ext_ack *)) | |
82ace47a | 2494 | { |
cbbdf843 | 2495 | struct netlink_ext_ack extack; |
82ace47a TG |
2496 | struct nlmsghdr *nlh; |
2497 | int err; | |
2498 | ||
2499 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2500 | int msglen; |
2501 | ||
cd443f1e | 2502 | memset(&extack, 0, sizeof(extack)); |
b529ccf2 | 2503 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2504 | err = 0; |
82ace47a | 2505 | |
ad8e4b75 | 2506 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2507 | return 0; |
2508 | ||
d35b6856 TG |
2509 | /* Only requests are handled by the kernel */ |
2510 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2511 | goto ack; |
45e7ae7f TG |
2512 | |
2513 | /* Skip control messages */ | |
2514 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2515 | goto ack; |
d35b6856 | 2516 | |
2d4bc933 | 2517 | err = cb(skb, nlh, &extack); |
5c58298c DL |
2518 | if (err == -EINTR) |
2519 | goto skip; | |
2520 | ||
2521 | ack: | |
d35b6856 | 2522 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
2d4bc933 | 2523 | netlink_ack(skb, nlh, err, &extack); |
82ace47a | 2524 | |
5c58298c | 2525 | skip: |
6ac552fd | 2526 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2527 | if (msglen > skb->len) |
2528 | msglen = skb->len; | |
2529 | skb_pull(skb, msglen); | |
82ace47a TG |
2530 | } |
2531 | ||
2532 | return 0; | |
2533 | } | |
6ac552fd | 2534 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2535 | |
d387f6ad TG |
2536 | /** |
2537 | * nlmsg_notify - send a notification netlink message | |
2538 | * @sk: netlink socket to use | |
2539 | * @skb: notification message | |
15e47304 | 2540 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2541 | * @group: destination multicast group or 0 |
2542 | * @report: 1 to report back, 0 to disable | |
2543 | * @flags: allocation flags | |
2544 | */ | |
15e47304 | 2545 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2546 | unsigned int group, int report, gfp_t flags) |
2547 | { | |
2548 | int err = 0; | |
2549 | ||
2550 | if (group) { | |
15e47304 | 2551 | int exclude_portid = 0; |
d387f6ad TG |
2552 | |
2553 | if (report) { | |
63354797 | 2554 | refcount_inc(&skb->users); |
15e47304 | 2555 | exclude_portid = portid; |
d387f6ad TG |
2556 | } |
2557 | ||
1ce85fe4 PNA |
2558 | /* errors reported via destination sk->sk_err, but propagate |
2559 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2560 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
fef773fc YD |
2561 | if (err == -ESRCH) |
2562 | err = 0; | |
d387f6ad TG |
2563 | } |
2564 | ||
1ce85fe4 PNA |
2565 | if (report) { |
2566 | int err2; | |
2567 | ||
15e47304 | 2568 | err2 = nlmsg_unicast(sk, skb, portid); |
fef773fc | 2569 | if (!err) |
1ce85fe4 PNA |
2570 | err = err2; |
2571 | } | |
d387f6ad TG |
2572 | |
2573 | return err; | |
2574 | } | |
6ac552fd | 2575 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2576 | |
1da177e4 LT |
2577 | #ifdef CONFIG_PROC_FS |
2578 | struct nl_seq_iter { | |
e372c414 | 2579 | struct seq_net_private p; |
56d28b1e | 2580 | struct rhashtable_iter hti; |
1da177e4 | 2581 | int link; |
1da177e4 LT |
2582 | }; |
2583 | ||
abf9979f | 2584 | static void netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2585 | { |
6c4128f6 | 2586 | rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti); |
97a6ec4a | 2587 | rhashtable_walk_start(&iter->hti); |
1da177e4 LT |
2588 | } |
2589 | ||
56d28b1e | 2590 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2591 | { |
56d28b1e HX |
2592 | rhashtable_walk_stop(&iter->hti); |
2593 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2594 | } |
2595 | ||
56d28b1e | 2596 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2597 | { |
56d28b1e | 2598 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2599 | struct netlink_sock *nlk; |
1da177e4 | 2600 | |
56d28b1e HX |
2601 | do { |
2602 | for (;;) { | |
56d28b1e | 2603 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2604 | |
56d28b1e HX |
2605 | if (IS_ERR(nlk)) { |
2606 | if (PTR_ERR(nlk) == -EAGAIN) | |
2607 | continue; | |
e341694e | 2608 | |
56d28b1e HX |
2609 | return nlk; |
2610 | } | |
1da177e4 | 2611 | |
56d28b1e HX |
2612 | if (nlk) |
2613 | break; | |
1da177e4 | 2614 | |
56d28b1e HX |
2615 | netlink_walk_stop(iter); |
2616 | if (++iter->link >= MAX_LINKS) | |
2617 | return NULL; | |
da12c90e | 2618 | |
abf9979f | 2619 | netlink_walk_start(iter); |
1da177e4 | 2620 | } |
56d28b1e | 2621 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2622 | |
56d28b1e HX |
2623 | return nlk; |
2624 | } | |
1da177e4 | 2625 | |
56d28b1e | 2626 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
64fbca01 | 2627 | __acquires(RCU) |
56d28b1e HX |
2628 | { |
2629 | struct nl_seq_iter *iter = seq->private; | |
2630 | void *obj = SEQ_START_TOKEN; | |
2631 | loff_t pos; | |
56d28b1e HX |
2632 | |
2633 | iter->link = 0; | |
2634 | ||
abf9979f | 2635 | netlink_walk_start(iter); |
56d28b1e HX |
2636 | |
2637 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2638 | obj = __netlink_seq_next(seq); | |
2639 | ||
2640 | return obj; | |
2641 | } | |
2642 | ||
2643 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2644 | { | |
2645 | ++*pos; | |
2646 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2647 | } |
2648 | ||
138d0be3 | 2649 | static void netlink_native_seq_stop(struct seq_file *seq, void *v) |
1da177e4 | 2650 | { |
56d28b1e HX |
2651 | struct nl_seq_iter *iter = seq->private; |
2652 | ||
2653 | if (iter->link >= MAX_LINKS) | |
2654 | return; | |
2655 | ||
2656 | netlink_walk_stop(iter); | |
1da177e4 LT |
2657 | } |
2658 | ||
2659 | ||
138d0be3 | 2660 | static int netlink_native_seq_show(struct seq_file *seq, void *v) |
1da177e4 | 2661 | { |
658cb354 | 2662 | if (v == SEQ_START_TOKEN) { |
1da177e4 | 2663 | seq_puts(seq, |
ae552ac2 YB |
2664 | "sk Eth Pid Groups " |
2665 | "Rmem Wmem Dump Locks Drops Inode\n"); | |
658cb354 | 2666 | } else { |
1da177e4 LT |
2667 | struct sock *s = v; |
2668 | struct netlink_sock *nlk = nlk_sk(s); | |
2669 | ||
ea9a0379 | 2670 | seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n", |
1da177e4 LT |
2671 | s, |
2672 | s->sk_protocol, | |
15e47304 | 2673 | nlk->portid, |
513c2500 | 2674 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2675 | sk_rmem_alloc_get(s), |
2676 | sk_wmem_alloc_get(s), | |
16b304f3 | 2677 | nlk->cb_running, |
41c6d650 | 2678 | refcount_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2679 | atomic_read(&s->sk_drops), |
2680 | sock_i_ino(s) | |
1da177e4 LT |
2681 | ); |
2682 | ||
2683 | } | |
2684 | return 0; | |
2685 | } | |
2686 | ||
138d0be3 YS |
2687 | #ifdef CONFIG_BPF_SYSCALL |
2688 | struct bpf_iter__netlink { | |
2689 | __bpf_md_ptr(struct bpf_iter_meta *, meta); | |
2690 | __bpf_md_ptr(struct netlink_sock *, sk); | |
2691 | }; | |
2692 | ||
2693 | DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk) | |
2694 | ||
2695 | static int netlink_prog_seq_show(struct bpf_prog *prog, | |
2696 | struct bpf_iter_meta *meta, | |
2697 | void *v) | |
2698 | { | |
2699 | struct bpf_iter__netlink ctx; | |
2700 | ||
2701 | meta->seq_num--; /* skip SEQ_START_TOKEN */ | |
2702 | ctx.meta = meta; | |
2703 | ctx.sk = nlk_sk((struct sock *)v); | |
2704 | return bpf_iter_run_prog(prog, &ctx); | |
2705 | } | |
2706 | ||
2707 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2708 | { | |
2709 | struct bpf_iter_meta meta; | |
2710 | struct bpf_prog *prog; | |
2711 | ||
2712 | meta.seq = seq; | |
2713 | prog = bpf_iter_get_info(&meta, false); | |
2714 | if (!prog) | |
2715 | return netlink_native_seq_show(seq, v); | |
2716 | ||
2717 | if (v != SEQ_START_TOKEN) | |
2718 | return netlink_prog_seq_show(prog, &meta, v); | |
2719 | ||
2720 | return 0; | |
2721 | } | |
2722 | ||
2723 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2724 | { | |
2725 | struct bpf_iter_meta meta; | |
2726 | struct bpf_prog *prog; | |
2727 | ||
2728 | if (!v) { | |
2729 | meta.seq = seq; | |
2730 | prog = bpf_iter_get_info(&meta, true); | |
2731 | if (prog) | |
2732 | (void)netlink_prog_seq_show(prog, &meta, v); | |
2733 | } | |
2734 | ||
2735 | netlink_native_seq_stop(seq, v); | |
2736 | } | |
2737 | #else | |
2738 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2739 | { | |
2740 | return netlink_native_seq_show(seq, v); | |
2741 | } | |
2742 | ||
2743 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2744 | { | |
2745 | netlink_native_seq_stop(seq, v); | |
2746 | } | |
2747 | #endif | |
2748 | ||
56b3d975 | 2749 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2750 | .start = netlink_seq_start, |
2751 | .next = netlink_seq_next, | |
2752 | .stop = netlink_seq_stop, | |
2753 | .show = netlink_seq_show, | |
2754 | }; | |
1da177e4 LT |
2755 | #endif |
2756 | ||
2757 | int netlink_register_notifier(struct notifier_block *nb) | |
2758 | { | |
efa172f4 | 2759 | return blocking_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2760 | } |
6ac552fd | 2761 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2762 | |
2763 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2764 | { | |
efa172f4 | 2765 | return blocking_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2766 | } |
6ac552fd | 2767 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2768 | |
90ddc4f0 | 2769 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2770 | .family = PF_NETLINK, |
2771 | .owner = THIS_MODULE, | |
2772 | .release = netlink_release, | |
2773 | .bind = netlink_bind, | |
2774 | .connect = netlink_connect, | |
2775 | .socketpair = sock_no_socketpair, | |
2776 | .accept = sock_no_accept, | |
2777 | .getname = netlink_getname, | |
a11e1d43 | 2778 | .poll = datagram_poll, |
025c6818 | 2779 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2780 | .listen = sock_no_listen, |
2781 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2782 | .setsockopt = netlink_setsockopt, |
2783 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2784 | .sendmsg = netlink_sendmsg, |
2785 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2786 | .mmap = sock_no_mmap, |
1da177e4 LT |
2787 | .sendpage = sock_no_sendpage, |
2788 | }; | |
2789 | ||
ec1b4cf7 | 2790 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2791 | .family = PF_NETLINK, |
2792 | .create = netlink_create, | |
2793 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2794 | }; | |
2795 | ||
4665079c | 2796 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2797 | { |
2798 | #ifdef CONFIG_PROC_FS | |
c3506372 CH |
2799 | if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops, |
2800 | sizeof(struct nl_seq_iter))) | |
b4b51029 EB |
2801 | return -ENOMEM; |
2802 | #endif | |
2803 | return 0; | |
2804 | } | |
2805 | ||
4665079c | 2806 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2807 | { |
2808 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2809 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2810 | #endif |
2811 | } | |
2812 | ||
b963ea89 DM |
2813 | static void __init netlink_add_usersock_entry(void) |
2814 | { | |
5c398dc8 | 2815 | struct listeners *listeners; |
b963ea89 DM |
2816 | int groups = 32; |
2817 | ||
5c398dc8 | 2818 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2819 | if (!listeners) |
5c398dc8 | 2820 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2821 | |
2822 | netlink_table_grab(); | |
2823 | ||
2824 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2825 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2826 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2827 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2828 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2829 | |
2830 | netlink_table_ungrab(); | |
2831 | } | |
2832 | ||
022cbae6 | 2833 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2834 | .init = netlink_net_init, |
2835 | .exit = netlink_net_exit, | |
2836 | }; | |
2837 | ||
49f7b33e | 2838 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2839 | { |
2840 | const struct netlink_sock *nlk = data; | |
2841 | struct netlink_compare_arg arg; | |
2842 | ||
da314c99 | 2843 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2844 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2845 | } |
2846 | ||
2847 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2848 | .head_offset = offsetof(struct netlink_sock, node), | |
2849 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2850 | .obj_hashfn = netlink_hash, |
2851 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2852 | .automatic_shrinking = true, |
c428ecd1 HX |
2853 | }; |
2854 | ||
138d0be3 | 2855 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
951cf368 YS |
2856 | BTF_ID_LIST(btf_netlink_sock_id) |
2857 | BTF_ID(struct, netlink_sock) | |
2858 | ||
14fc6bd6 | 2859 | static const struct bpf_iter_seq_info netlink_seq_info = { |
15172a46 YS |
2860 | .seq_ops = &netlink_seq_ops, |
2861 | .init_seq_private = bpf_iter_init_seq_net, | |
2862 | .fini_seq_private = bpf_iter_fini_seq_net, | |
2863 | .seq_priv_size = sizeof(struct nl_seq_iter), | |
14fc6bd6 YS |
2864 | }; |
2865 | ||
2866 | static struct bpf_iter_reg netlink_reg_info = { | |
2867 | .target = "netlink", | |
3c32cc1b YS |
2868 | .ctx_arg_info_size = 1, |
2869 | .ctx_arg_info = { | |
2870 | { offsetof(struct bpf_iter__netlink, sk), | |
2871 | PTR_TO_BTF_ID_OR_NULL }, | |
2872 | }, | |
14fc6bd6 | 2873 | .seq_info = &netlink_seq_info, |
15172a46 YS |
2874 | }; |
2875 | ||
138d0be3 YS |
2876 | static int __init bpf_iter_register(void) |
2877 | { | |
951cf368 | 2878 | netlink_reg_info.ctx_arg_info[0].btf_id = *btf_netlink_sock_id; |
15172a46 | 2879 | return bpf_iter_reg_target(&netlink_reg_info); |
138d0be3 YS |
2880 | } |
2881 | #endif | |
2882 | ||
1da177e4 LT |
2883 | static int __init netlink_proto_init(void) |
2884 | { | |
1da177e4 | 2885 | int i; |
1da177e4 LT |
2886 | int err = proto_register(&netlink_proto, 0); |
2887 | ||
2888 | if (err != 0) | |
2889 | goto out; | |
2890 | ||
138d0be3 YS |
2891 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2892 | err = bpf_iter_register(); | |
2893 | if (err) | |
2894 | goto out; | |
2895 | #endif | |
2896 | ||
c593642c | 2897 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb)); |
1da177e4 | 2898 | |
0da974f4 | 2899 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2900 | if (!nl_table) |
2901 | goto panic; | |
1da177e4 | 2902 | |
1da177e4 | 2903 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2904 | if (rhashtable_init(&nl_table[i].hash, |
2905 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2906 | while (--i > 0) |
2907 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2908 | kfree(nl_table); |
fab2caf6 | 2909 | goto panic; |
1da177e4 | 2910 | } |
1da177e4 LT |
2911 | } |
2912 | ||
b963ea89 DM |
2913 | netlink_add_usersock_entry(); |
2914 | ||
1da177e4 | 2915 | sock_register(&netlink_family_ops); |
b4b51029 | 2916 | register_pernet_subsys(&netlink_net_ops); |
25e3f70f | 2917 | register_pernet_subsys(&netlink_tap_net_ops); |
746fac4d | 2918 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2919 | rtnetlink_init(); |
2920 | out: | |
2921 | return err; | |
fab2caf6 AM |
2922 | panic: |
2923 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2924 | } |
2925 | ||
1da177e4 | 2926 | core_initcall(netlink_proto_init); |